Treatment of viral infections, diseases or conditions using selective s1r agonists

Abstract

The present invention provides a method for treating, reducing the incidence of, suppressing or inhibiting a viral infection, disease, disorder or symptom thereof in a subject in need thereof, comprising administering to the subject a selective SIR agonist. In another aspect, the viral disease is COVID-19 and the selective SIR agonist is pridopidine or a pharmaceutically acceptable salt thereof.

Description

Technical Field

[0001] This invention provides a method for treating a viral infection, disease, condition, or symptom in a subject in need, reducing the incidence of the viral infection, disease, condition, or symptom in a subject in need, and suppressing or inhibiting the viral infection, disease, condition, or symptom in a subject in need, the method comprising administering a selective S1R agonist to the subject. In another aspect, the viral disease is COVID-19, and the selective S1R agonist is pridopidine or a pharmaceutically acceptable salt thereof. Background Technology

[0002] Coronavirus disease 2019, or COVID-19, has rapidly become a global pandemic. A limited number of treatments have received emergency approval, and vaccination has only recently become available. Coronaviruses possess a single-stranded RNA genome and encode many similar proteins. Protein and RNA replication mechanisms are classic targets for antiviral drugs developed over the past few years. However, the life cycle of coronaviruses depends on several cellular pathways encoded by the host cell (Nabirotchkin et al. 2020). These pathways include the ER-stress unfolded protein response (UPR), autophagy, and mitochondrial function.

[0003] Recent bioinformatics / proteomics analyses (Gordon et al. 2020) identified SARS-CoV-2 proteins that interact with human σ-1 and σ-2 receptors (S1R / S2R) and promote disease progression. This highlights the σ receptor as a potential drug target for treating COVID-19. Among approximately 20 virus-encoded proteins, Nsp6 and Orf9c were identified as directly interacting with the σ receptor.

[0004] S1R is an ER chaperone protein located in the mitochondrial-associated membrane (MAM), which plays a crucial role in ER-mitochondrial interactions. S1R regulates ER stress, mitochondrial function, calcium signaling, autophagy, and cellular homeostasis (Weng, Tsai, and Su 2017; Delprat et al. 2020). S1R deficiency enhances ER stress and oxidative stress, while S1R overexpression and activation by various agonists restore cellular homeostasis and enhance survival. S1R activation has been shown to reduce ER stress, restore mitochondrial function, and enhance autophagy (Tesei et al. 2018; Maurice et al. 1994; Christ et al. 2019).

[0005] S2R is an intracellular chaperone protein recently cloned and identified as TMEM97 (Alon et al. 2017). Although S1R and S2R are not genetically related, they share similar pharmacological properties, and some S1R ligands have also shown high affinity for S2Rs including haloperidol and DTG (Longhitano et al. 2017; Tesei et al. 2018; Katnik et al. 2006). Several S2R ligands have shown to induce apoptosis, making them attractive anticancer agents (Tesei et al. 2019).

[0006] Several σ-ligands have recently been reported to exhibit antiviral activity (Gordon et al. 2020). σ-ligands exhibiting antiviral activity (measured by viral titer assay) include hydroxychloroquine, cleemastine, and haloperidol. All of these compounds show high affinity for both S1R and S2R, and are therefore all non-selective. Hydroxychloroquine has an S1R Ki of 200 nM and an S2R Ki of 800 nM, cleemastine has an S1R Ki of 10 nM and an S2R Ki of 20 nM, and haloperidol has an S1R Ki of 4 nM and an S2R Ki of 54 nM.

[0007] Gordon described the antiviral activities of hydroxychloroquine, clomastine, and haloperidol in his manuscript (Gordon et al. 2020). Hydroxychloroquine exhibited antiviral activity at approximately 2 μM, a dose associated with approximately 30% reduction in cell viability (Gordon et al. 2020). The effective dose of clomastine to achieve antiviral activity was 10 μM, and this dose was also associated with approximately 40% cell death. Similarly, haloperidol exhibited antiviral activity at 100 μM with approximately 30% cell death (Gordon et al. 2020).

[0008] Pridopidine (4-[3-(methylsulfonyl)phenyl]-1-propyl-piperidine) is a highly selective S1R ligand with Ki = 0.57 nM and S2R Ki = 5450 nM (Johnston et al. 2019). Therefore, pridopidine exhibits a 95-fold higher affinity for the S1R than for the S2R and is the most selective S1R ligand. Summary of the Invention

[0009] In a first aspect, the present invention provides a method for treating a viral infection, disease, condition or symptom in a subject in need, reducing the incidence of a viral infection, disease, condition or symptom in a subject in need, and suppressing or inhibiting a viral infection, disease, condition or symptom in a subject in need, the method comprising administering to the subject a composition comprising a selective S1R agonist.

[0010] In another aspect, the present invention provides a method for reducing endoplasmic reticulum stress (ER stress) in a subject due to viral infection, disease, or condition, the method comprising administering to the subject a composition comprising a selective S1R agonist.

[0011] In another aspect, the present invention provides a method for treating a human coronavirus or its symptoms or mutations in a subject in need, reducing the incidence of human coronavirus or its symptoms or mutations in a subject in need, and suppressing or inhibiting human coronavirus or its symptoms or mutations in a subject in need, the method comprising administering to the subject a composition comprising a selective S1R agonist.

[0012] In another aspect, the present invention provides a method for treating viral infections, diseases, conditions, or symptoms in a subject in need, reducing the incidence of viral infections, diseases, conditions, or symptoms in a subject in need, and suppressing or inhibiting viral infections, diseases, conditions, or symptoms in a subject in need, said method comprising administering a composition comprising: pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or a combination of pridopidine and at least one of 1 to 7 of similar compounds or salts of said similar compounds:

[0013] (1) (2)

[0014] (3) (4)

[0015] (5) (6)

[0016] or (7).

[0017] In some embodiments, the viral infection, disease, or symptom includes human coronaviruses, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) coronavirus, SARS coronavirus 2 (SARS-CoV-2), or mutations thereof. In other embodiments, the disease is COVID-19.

[0018] In some embodiments, the method of the present invention utilizes a selective S1R agonist. In another embodiment, the selective S1R agonist is a combination of pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or at least one of pridopidine and analogous compounds 1 to 7 thereof or salts of said analogous compounds.

[0019] In some embodiments, the pridopidine is in a neutral / basic form. In some embodiments, the pridopidine is in the form of a pharmaceutically acceptable salt. In some other embodiments, the pridopidine is pridopidine hydrochloride.

[0020] In some embodiments, the composition comprising the selective S1R agonist is administered orally. In some embodiments, the composition comprising pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or a combination of pridopidine and at least one of pridopidine and analogous compounds 1 to 7 thereof or salts of such analogous compounds is administered orally.

[0021] In other embodiments, the composition is administered via systemic application. In another embodiment, the composition is administered orally. In yet another embodiment, the composition is formulated as an oral liquid, solid, semi-solid dosage form, injection, dermal / transdermal dosage form, ophthalmic dosage form, or inhalable composition. In yet another embodiment, the composition is formulated as an inhalable powder, injection, liquid, gel, solid, capsule, eye drops, or tablet.

[0022] In some embodiments, the composition is administered periodically (i.e., pridopidine is administered at regular, predetermined time intervals such as daily, hourly, weekly, or monthly, with each cycle optionally defining the dose to be administered and the number of administrations per time period). In other embodiments, the composition is administered once daily, twice daily, or three times daily. In still other embodiments, the composition is administered less than once daily. In some embodiments, the composition is administered as one dose daily, two doses daily, or three doses daily. Attached Figure Description

[0023] The concluding section of the specification specifically points out and explicitly claims protection for the subject matter considered to be the present invention. However, regarding the organization and methods of operation, together with its objectives, features, and advantages, the invention can be best understood by referring to the following detailed description, in which the accompanying drawings are drawn:

[0024] Figure 1Representative images are shown demonstrating that mutant Htt (mHtt) induces ER stress (H2a-GFP) via pridocipidine, which is quantified by H2a-GFP aggregation. Early ER stress is quantified using H2a-GFP (a protein indicator), which accumulates in response to ER stress to form aggregates. H2a-GFP is transiently co-expressed with wild-type (WT, Htt20Q)-mCherry or mutant (Htt96Q)-mCherry (exon 1) in STHdhQ7 / 7 cells. Cells were treated with pridocipidine at constant or increased concentrations (from 0.03 μM to 3 μM) starting 4 hours post-transfection and imaged under a confocal microscope at 24 hours post-transfection. Images of individual cells (approximately 150 cells per experiment) with Htt96Q-mCherry aggregates or Htt20Q-mCherry aggregates were quantified compared to untreated cells with or without aggregates.

[0025] Figure 2 Quantification of ER stress in cells with mHTT (left) or WT HTT (right) is shown. Pridocipidine significantly reduced early mutant Htt-induced ER stress, as measured in a dose-dependent manner by H2a-GFP aggregation. For comparative purposes, 100% represents the relative intensity of H2a-GFP in untreated cells exhibiting mHtt-mCherry aggregates, and 0% represents the relative intensity of H2a-GFP in untreated cells without mHtt-mcherry aggregates. The plot is the mean of the three experiments +-SE. An asterisk indicates a p-value compared to untreated cells, < 0.05 (*) and < 0.01 (**). WT HTT (right) did not induce ER stress, and no effect was observed.

[0026] Figure 3 At 8 hours, pridopidine reduced mutant Htt-induced eIF2α-phosphorylation (an ER stress marker). HEK293 cells were transfected with myc-Htt96Q (mutant HTT, square) or myc-Htt20Q (wt HTT, round) and then treated with pridopidine at increasing concentrations (from 0.03 μM to 3 μM) for 8 hours. The ratio of eIF2α-P to total eIF2α was quantified by Western blotting. Pridopidine reduced eIF2α-P levels in a dose-dependent manner, with a significant effect at a 3 μM dose (p < 0.01).

[0027] Figure 4At 24 hours, pridopidine reduced mutant Htt-induced eIF2α-phosphorylation (an ER stress marker). HEK293 cells were transfected with myc-Htt96Q (mutant HTT, square) or myc-Htt20Q (wt HTT, round) and then treated with pridopidine at increasing concentrations (from 0.03 μM to 3 μM) for 24 hours. The ratio of eIF2α-P to total eIF2α was quantified by Western blotting. Pridopidine reduced eIF2α-P levels in a dose-dependent manner, with significant effects at both 0.3 μM and 3 μM concentrations (p < 0.05).

[0028] Figure 5 Pridolpicin reduces eIF2α-phosphorylation (an ER stress marker) in cells where ER stress is induced by carotenoids. Carotenoids are potent inducers of ER stress. Treatment of HEK293 cells transfected with myc-Htt20Q (wt HTT) with 2 μg / ml carotenoids or no treatment resulted in a 70% increase in phosphorylated eIF2α (eIF2α-p). Pridolpicin treatment reduced p-eIF2α levels (3 μM).

[0029] Figure 6 Pridopidine reduces eIF2α-phosphorylation (an ER stress marker) via an S1R-dependent mechanism. HEK293 cells were transfected with a guide RNA (gRNA) targeting human S1R or a control gRNA. Htt96Q (mHTT) was transiently expressed in HEK 293 cells. Cells were treated with 0.3 μM and 3 μM pridopidine for 8 hours. The ratio of eIF2α-p to total eIF2α was measured and quantified by Western blotting. In S1R-expressing (S1R+ / +) cells, pridopidine treatment at 0.3 μM and 3 μM concentrations reduced p-eIF2α levels (p < 0.01). However, this effect was eliminated in the absence of S1R (S1R- / - cells), suggesting that the ER-stress-reducing effect of pridopidine is mediated by S1R. Data are mean ± SD from three experiments.

[0030] Figures 7A-7C Priligy reduces the folded response pathway (UPR) marker ATF4 ( Figure 7A CHOP Figure 7B ) and GADD34 ( Figure 7C Protein levels of myc-Htt96Q (mutant Htt) or myc-Htt20Q (wt Htt) were measured. Cells expressing myc-Htt96Q (mutant Htt) or myc-Htt20Q (wt Htt) were treated with 3 μM pridopidine. Immunoblotting was performed with anti-ATF4 (… Figure 7A ), anti-CHOP ( Figure 7B ) and anti-GADD34 ( Figure 7C The reaction was quantified and normalized using anti-actin or anti-tubulin as loading controls. Pridolpicine (3 μM) reduced ATF4 levels by approximately 4.5-fold (p < 0.05), CHOP by approximately 2-fold, and GADD-34 by approximately 2.5-fold (p < 0.01).

[0031] Figure 8 Prilidopidine reduced the protein level of the UPR marker ATF6. Cells expressing myc-Htt96Q (mutant Htt) were treated with 0.03 μM and 3 μM prilidopidine. Immunoblotting was performed with anti-ATF6, and quantification and normalization were performed using anti-microtubule protein as a loading control. The two concentrations of prilidopidine reduced ATF6 by approximately 10% and 30% at 0.03 μM and 3 μM concentrations, respectively.

[0032] Figure 9 Pridolpicine reduced the mRNA level of the UPR marker XBP1. Cells expressing myc-Htt96Q (mutant Htt) or myc-Htt20Q (wt Htt) were treated with 0.03 μM and 3 μM pridolpicine. XBP1 RNA levels were measured by quantitative PCR (polymerase chain reaction). XBP1 levels increased by 70% in cells transfected with mutant Htt. Pridolpicine treatment showed a significant 25% reduction in XBP1 levels at a concentration of 3 μM (p < 0.01).

[0033] Figure 10 Pridolpicine reduced mitochondrial reactive oxygen species (ROS) in YAC128 HD striatal neurons. YAC128 is a mouse model of Huntington's Disease (HD). Striatal neurons from wt or YAC128 were treated with 1 μM pridolpicine or untreated and incubated with the MitoPY1 fluorescent probe. The mitochondrial respiration inhibitor antimycin A (Ant A, 2 μM) was used to induce mitochondrial H2O2 release and oxidative stress. Mitochondrial H2O2 was recorded in a rotating disk before and after administration of Ant A (n = 4, considering approximately 20 cells / condition). Ant A increased H2O2 in untreated cells by approximately 2-fold. Pridolpicine treatment inhibited H2O2 release and oxidative stress. Scale bar = 30 μM. Two-way ANOVA revealed the rescue effect of pridopidine treatment on mitochondrial ROS production [F(1,389 = 15.24; p < 0.0001).

[0034] Figure 11 Following oxidative stress, pridopidine increased mitochondrial membrane potential (MMP) in cortical HD neurons. Striatal WT and YAC128 (HD) neurons were treated with pridopidine for 24 hours, and changes in MMP following depolarization with oligomycin and FCCP (carbonylaniline-4-phenylhydrazone) were assessed using tetramethylrhodamine methyl ester (TMRM) (n = 7–10). HD neurons showed reduced MMP. Pridopidine treatment enhanced MMP in WT neurons and significantly restored impaired MMP in HD neurons (two-way ANOVA analysis [F(2,107) = 3.257; p = 0.0423]).

[0035] Figure 12 The effect of pridopidine on mitochondrial membrane potential (MMP) is mediated by S1R. S1R was knocked down (KD) in lymphoblasts from HD patients (S1R KD), showing a reduction of approximately 83% in S1R protein levels. Cells were treated with 5 μM pridopidine and then challenged with 0.1 mM H2O2. MMP was quantified by tetramethylrhodamine ethyl ester (TMRE) signaling in control and S1R-KD HD lymphoblasts (5 μM, 24 h, n = 4). H2O2 treatment significantly reduced MMP in both S1R+ / + cells and S1R KD cells, by 25% and 75%, respectively. Pridopidine treatment completely restored MMP in S1R+ / + cells but not in S1R KD cells, indicating that the effect of pridopidine is mediated by S1R. According to the Kruskal Wallistest test and the Dunn multiple comparison test, ****p < 0.0001. Detailed Implementation

[0036] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, those skilled in the art will understand that the invention can be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the invention.

[0037] In a first aspect, the present invention provides a method for treating a viral infection, disease, condition or symptom in a subject in need, reducing the incidence of a viral infection, disease, condition or symptom in a subject in need, and suppressing or inhibiting a viral infection, disease, condition or symptom in a subject in need, the method comprising administering to the subject a composition comprising a selective S1R agonist.

[0038] In another aspect, the present invention provides a method for treating viral infections, diseases, conditions, or symptoms in a subject in need, reducing the incidence of viral infections, diseases, conditions, or symptoms in a subject in need, and suppressing or inhibiting viral infections, diseases, conditions, or symptoms in a subject in need, said method comprising administering a composition comprising: pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or a combination of pridopidine and at least one of 1 to 7 of similar compounds or salts of said similar compounds:

[0039] (1) (2)

[0040] (3) (4)

[0041] (5) (6)

[0042] or (7).

[0043] When “viral infection, disease, symptom or any symptom” is mentioned, it should be understood to cover any type of illness that poses a risk to the health of the subject, wherein the viral infection plays a direct or indirect role.

[0044] In some embodiments, the viral infection, disease, or condition includes human coronaviruses, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) coronavirus, SARS coronavirus 2, or mutations thereof. In other embodiments, the disease is COVID-19 treated with the administration of a composition comprising a selective S1R agonist.

[0045] In one embodiment, the present invention provides a method for treating human coronavirus or its mutations and / or symptoms by administering a composition comprising a selective S1R agonist, reducing the incidence of human coronavirus or its mutations and / or symptoms, and suppressing or inhibiting human coronavirus or its mutations and / or symptoms.

[0046] In one embodiment, the present invention provides a method for treating severe acute respiratory syndrome (SARS) or its mutations and / or symptoms by administering a composition comprising a selective S1R agonist, reducing the incidence of SARS or its mutations and / or symptoms, or suppressing or inhibiting SARS or its mutations and / or symptoms.

[0047] In one embodiment, the present invention provides a method for treating Middle East Respiratory Syndrome (MERS) coronavirus or its mutations and / or symptoms by administering a composition comprising a selective S1R agonist, reducing the incidence of MERS coronavirus or its mutations and / or symptoms, or suppressing or inhibiting MERS coronavirus or its mutations and / or symptoms.

[0048] In one embodiment, the present invention provides a method for treating SARS coronavirus 2 (SARS-CoV-2) or its mutations and / or its symptoms by administering a composition comprising a selective S1R agonist, reducing the incidence of SARS-CoV-2 or its mutations and / or its symptoms, and suppressing or inhibiting SARS-CoV-2 or its mutations and / or its symptoms.

[0049] In one embodiment, the present invention provides a method for treating COVID-19 or its mutations and / or its symptoms by administering a composition comprising a selective S1R agonist, reducing the incidence of COVID-19 or its mutations and / or its symptoms, and suppressing or inhibiting COVID-19 or its mutations and / or its symptoms.

[0050] In one embodiment, the present invention provides a method for reducing ER stress in a subject due to a viral infection, disease, or condition. In another embodiment, the viral infection, disease, or condition includes human coronaviruses, SARS, MERS coronaviruses, SARS coronavirus 2, mutations thereof, and / or their symptoms. In yet another embodiment, the disease is COVID-19, treated with administration of a composition comprising a selective S1R agonist.

[0051] In some embodiments, the present invention provides a method for treating Middle East Respiratory Syndrome (MERS) coronavirus or its mutations and / or symptoms by administering a composition comprising a selective S1R agonist, reducing the incidence of MERS coronavirus or its mutations and / or symptoms, and suppressing or inhibiting MERS coronavirus or its mutations and / or symptoms. In other embodiments, the symptoms include kidney failure, fever, fatigue, dry cough, pain, nasal congestion, runny nose, sore throat, diarrhea, or a combination thereof.

[0052] The most common symptoms of COVID-19 are fever, dry cough, and fatigue. Some people may also experience aches, nasal congestion, sore throat, or diarrhea. These symptoms are usually mild and develop gradually. Some people are infected but experience only very mild symptoms. Most people (about 80%) recover from the illness without needing hospital treatment. About one in five people who have COVID-19 will develop a more serious condition and difficulty breathing. Older adults and people with underlying medical conditions such as high blood pressure, heart or lung problems, diabetes, or cancer are at higher risk of developing a serious illness. However, anyone can get COVID-19 and develop a more serious condition. Even people with very mild COVID-19 symptoms can spread the virus. People of all ages who experience fever, cough, and difficulty breathing should seek medical attention.

[0053] In some embodiments, the present invention provides a method for treating COVID-19 by administering a composition comprising a selective S1R agonist, reducing the incidence of COVID-19, or containing or inhibiting COVID-19. In other embodiments, the symptoms include kidney failure, fever, fatigue, dry cough, pain, nasal congestion, runny nose, sore throat, diarrhea, or a combination thereof.

[0054] In some embodiments, the method of the present invention utilizes a composition comprising a selective S1R agonist. In other embodiments, the S1R agonist is a combination of pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or a combination of at least one of pridopidine and analogous compounds 1 to 7 thereof or salts of said analogous compounds.

[0055] SAR-CoV-2 infection induces ER stress unfolded protein response (UPR) / autophagy pathway in the life cycle of coronaviruses The period is crucial:

[0056] In response to viral invasion, host cells activate the unfolded protein response (UPR) in an attempt to restore endoplasmic reticulum (ER) homeostasis by shutting down global protein translation.

[0057] UPR induction via coronavirus invasion constitutes a major aspect of virus-host cell interactions. ER stress and UPR activation significantly contribute to viral replication and pathogenesis during coronavirus infection (Fung and Liu 2014).

[0058] This virus manipulates the UPR to complete its life cycle and enhances its replication (Cava, Bertoli, and Castiglioni 2020). The reduction of ER stress makes it an attractive candidate target for antiviral therapy.

[0059] Previously identified coronaviruses such as SARS-CoV and MERS-CoV have been shown to induce ER stress, thereby utilizing the ER for viral replication and interfering with the apoptosis pathway to ensure sustained viral replication (S. Li et al. 2020; DeDiego et al. 2011). It has been shown that SARS-CoV induction of UPR selectively modulates its function to enhance its replication while avoiding apoptosis (Chan et al. 2006).

[0060] Viral infection-induced ER stress leads to eIF2α phosphorylation, which inhibits overall translation in cells but increases the translation of UPR-related genes such as ATF4 and CHOP (Bechill et al. 2008; K. Liao et al. 2016).

[0061] In some embodiments, selective S1R agonists reduce ER stress in patients with viral infections, diseases, or conditions. In other embodiments, the selective S1R agonist is a combination of pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or at least one of pridopidine and analogous compounds 1 to 7 or salts of said analogous compounds.

[0062] UPR pathway along with autophagy pathway Autophagy is crucial for viral infection, regulation of protein homeostasis, innate immunity, and clearance of viral particles. For example, the coronavirus MERS-CoV blocks the autophagy pathway (Gassen et al. 2019).

[0063] In some embodiments, a selective S1R agonist modulates ER stress and the UPR pathway in patients with viral infections, diseases, or conditions. In another embodiment, a selective S1R agonist reduces ER stress. In other embodiments, the selective S1R agonist is a combination of pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or a combination of at least one of pridopidine and 1 to 7 of its similar compounds or salts of said similar compounds.

[0064] In some embodiments, the selective S1R agonist modulates the autophagy pathway in patients suffering from viral infections, diseases, or conditions. In other embodiments, the selective S1R agonist is a combination of pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or at least one of pridopidine and analogous compounds 1 to 7 or salts of said analogous compounds.

[0065] Oxidative stress and mitochondrial dysfunction in COVID-19

[0066] Mitochondria play a crucial role in controlling ROS levels, and dysfunctional mitochondria produce high, uncontrolled levels of toxic ROS (excessive ROS levels cause widespread cellular damage and protein oxidation). Specifically, SARS-CoV-2 infection has been shown to enhance ROS levels, primarily due to immune system activity (Wang, Zhang, and Bai 2020; Starkov 2008). The SARS-CoV ORF8 protein is located in mitochondria, where it induces increased ROS production, suggesting its role in regulating ROS production and mitochondrial function (Chen et al. 2007). Therefore, ROS reduction is a potential target for COVID-19 management.

[0067] In some embodiments, selective S1R agonists reduce ROS in patients with viral infections, diseases, or conditions. In other embodiments, the selective S1R agonist is a combination of pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or at least one of pridopidine and analogous compounds 1 to 7 or salts of said analogous compounds.

[0068] Patients infected with SARS-CoV-2 have high plasma levels of pro-inflammatory cytokines, including IL-1β, IL-2, TNFα, MCP1, IL7, and GSCF (Harapan et al. 2020). Increased cytokine levels are a common complication of respiratory diseases, where excessive production of early-response pro-inflammatory cytokines can lead to serious complications, including multiple organ failure and death (Ricardo J Jose and Manuel 2020). Patients in the ICU have significantly higher levels of GSCF, MCP1, and TNFα, suggesting that cytokine storms may be a potential cause of disease severity. Treatment with S1R agonists has been shown to reduce cytokine levels and suppress the inflammatory response (Zhao et al. 2014; Allahtavakoli and Jarrott 2011).

[0069] In some embodiments, a selective S1R agonist reduces cytokine plasma levels in patients suffering from viral infections, diseases, or conditions. In other embodiments, the selective S1R agonist is a combination of pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or at least one of pridopidine and 1 to 7 of its analog compounds or salts of said analog compounds.

[0070] Composition for use in the method of the present invention

[0071] In some embodiments, the present invention provides a composition comprising a selective S1R agonist for use in the method of the present invention. In some embodiments, the present invention provides a composition comprising pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or a combination of pridopidine and at least one of pridopidine and analogous compounds 1 to 7 thereof or salts of said analogous compounds for use in the method of the present invention.

[0072] In some embodiments, the present invention provides a composition comprising a selective S1R agonist for treating viral infections, diseases, conditions or symptoms in a subject in need, reducing the incidence of viral infections, diseases, conditions or symptoms in a subject in need, and inhibiting or suppressing viral infections, diseases, conditions or symptoms in a subject in need.

[0073] In some embodiments, the present invention provides a composition comprising the following for treating viral infections, diseases, conditions or symptoms in subjects in need, reducing the incidence of viral infections, diseases, conditions or symptoms in subjects in need, and inhibiting or suppressing viral infections, diseases, conditions or symptoms in subjects in need: pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or a combination of pridopidine and at least one of 1 to 7 of similar compounds or salts of said similar compounds.

[0074] In some embodiments, the present invention provides a composition comprising a selective S1R agonist for reducing endoplasmic reticulum stress (ER stress) in subjects in need due to viral infection, disease, or condition.

[0075] In some embodiments, the present invention provides a composition comprising pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or a combination of at least one of pridopidine and analogous compounds 1 to 7 thereof or salts thereof for reducing endoplasmic reticulum stress (ER stress) in subjects in need due to viral infection, disease or condition: pridopidine, a pharmaceutically acceptable salt thereof, a deuterated analog thereof, or a combination of pridopidine and at least one of analogous compounds 1 to 7 thereof or salts thereof.

[0076] In some embodiments, the composition used in the method of the present invention comprises pridopidine or a pharmaceutically acceptable salt thereof. In another embodiment, pridopidine is a neutral base / free base. In yet another embodiment, pridopidine is in the form of a pharmaceutically acceptable salt thereof.

[0077] In another embodiment, the pridopidine salt includes pridopidine hydrochloride, pridopidine hydrobromide, pridopidine hydroiodide, pridopidine nitrate, pridopidine sulfate, pridopidine hydrogen sulfate, pridopidine phosphate, pridopidine acid phosphate, pridopidine isonicotinate, pridopidine acetate, pridopidine lactate, pridopidine salicylate, pridopidine citrate, pridopidine D,L-tartrate, pridopidine L-tartrate, pridopidine D-tartrate, pridopidine pantothenate, pridopidine hydrogen tartrate, pridopidine ascorbate, pridopidine succinate, pridopidine hemisuccinate, and pridopidine maleate. The following salts are included: pridopidine gentisinate, pridopidine gentianate, pridopidine fumarate, pridopidine gluconate, pridopidine glucuronate, pridopidine glycolate, pridopidine sucrose salt, pridopidine formate, pridopidine benzenesulfonate, pridopidine benzoate, pridopidine glutamate, pridopidine malate, pridopidine methanesulfonate, pridopidine ethanesulfonate, pridopidine benzenesulfonate, pridopidine p-toluenesulfonate, pridopidine oxalate, pridopidine toluenesulfonate, pridopidine naphthalene-2-sulfate, or bis(hydroxynaphthalene) (i.e., 1,1'-methylene-bis-(2-hydroxy-3-naphthylcarbamate)). In another embodiment, the pridopidine salt is pridopidine hydrochloride.

[0078] In some embodiments, the composition used in the method of the present invention comprises a combination of at least one of pridopidine and its similar compounds 1 to 7 or salts of said similar compounds:

[0079] (1) (2)

[0080] (3) (4)

[0081] (5) (6)

[0082] or (7).

[0083] In other embodiments, similar compounds 1 to 7 of pridopidine and methods for their preparation can be found in U.S. Patent Nos. 10,130,621 and 10,406,145, the entire contents of each of which are hereby incorporated by reference.

[0084] In some embodiments, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof and at least compound 1 or a pharmaceutically acceptable salt thereof. In other embodiments, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof and compound 4 or a pharmaceutically acceptable salt thereof. In other embodiments, the composition used in the method of the present invention comprises a combination of pridopidine and compound 1 or a pharmaceutically acceptable salt thereof and compound 4 or a pharmaceutically acceptable salt thereof. In other embodiments, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof and at least compound 2 or a pharmaceutically acceptable salt thereof. In other embodiments, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof and at least compound 3 or a pharmaceutically acceptable salt thereof. In other embodiments, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof and at least compound 4 or a pharmaceutically acceptable salt thereof. In other embodiments, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof and at least compound 5 or a pharmaceutically acceptable salt thereof. In other embodiments, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof and at least compound 6 or a pharmaceutically acceptable salt thereof. In other embodiments, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof and at least compound 7 or a pharmaceutically acceptable salt thereof.

[0085] In another embodiment, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof with at least one of compounds 1 to 7, wherein at least one of compounds 1 to 7 constitutes 0.01% to 5% by weight of the composition. In another embodiment, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof with at least one of compounds 1 to 7, wherein at least one of compounds 1 to 7 constitutes 0.01% to 1%, 0.05% to 0.5%, or 0.05% to 1% by weight of the composition. In another embodiment, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof with compound 1 or a pharmaceutically acceptable salt thereof, wherein compound 1 constitutes between 0.01% to 5%, 0.01% to 1%, 0.05% to 0.5%, or 0.05% to 1% by weight of the composition. In another embodiment, the composition used in the method of the present invention comprises a combination of pridopidine or a pharmaceutically acceptable salt thereof and compound 4 or a pharmaceutically acceptable salt thereof, wherein compound 4 comprises a weight percentage of the composition between 0.01% and 5%, 0.01% and 1%, 0.05% and 0.5% or 0.05% and 1%.

[0086] In some embodiments, the present invention provides a composition comprising a deuterated analogue of pridopidine for use in the methods of the present invention. Deuterated analogues "This refers to a compound where the abundance of deuterium at any relevant site is greater than the abundance of deuterium in a given amount of the compound naturally present at that site." Deuterium-rich "Compound. Deuterium is naturally distributed at a rate of approximately 0.0156%. Therefore, in " Deuterium-rich "In the compound, the abundance of deuterium at any of the deuterium-related sites exceeds 0.0156%, and can be in the range of more than 0.0156% to 100%. The deuterium-rich compound can be obtained by exchanging hydrogen for deuterium or by synthesizing the compound with deuterium-rich starting materials."

[0087] In other embodiments, examples of deuterated analogues of pridopidine and methods for their preparation can be found in U.S. Patent Application Publications Nos. 2013-0197031, 2016-0166559 and US-2019-0015401, the entire contents of each of which are hereby incorporated by reference.

[0088] In other embodiments, the deuterated analogues of pridopidine are selected from:

[0089] , or

[0090]

[0091] For the methods and uses disclosed herein, the route of administration may be, for example, oral. Routes of administration can also be categorized by whether the action is local (e.g., topical application) or systemic (e.g., enteric or parenteral administration). As used herein, “topical application” means applying the compound or composition directly to the site where its action is desired, and specifically excludes systemic administration. As used herein, “topical application” of a compound or composition means applying the compound or composition to a body surface, such as the skin or mucous membranes, such as the eyes. As used herein, “ocular application” means applying the compound or composition to the eyes of a subject or the skin around the eyes (periocular skin) or the mucous membranes around the eyes, particularly the conjunctiva of the subject, i.e., topical application.

[0092] The present invention provides a certain amount of pridopidine or a selective S1R agonist and pharmaceutical composition that can be administered orally, topically, systemically, or ocularly.

[0093] In some embodiments, the compositions disclosed herein for use in the methods of the invention are administered via systemic administration. In other embodiments, the compositions are administered via oral administration. In other embodiments, the compositions are formulated as oral liquids, solids, semi-solid dosage forms, injections, skin / transdermal dosage forms, eye drops, or as inhalable compositions. In other embodiments, the compositions are formulated as inhalable powders, injections, liquids, gels, solids, capsules, eye drops, or as tablets.

[0094] In some embodiments, the compositions disclosed herein for use in the methods of the invention are applied once daily, twice daily, three times daily, or less than once daily.

[0095] In some embodiments, the compositions disclosed herein for use in the methods of the invention are administered once, twice, or three times daily.

[0096] Examples of pridopidine derivatives are deuterium-enriched pridopidine and its salts. Examples of deuterium-enriched pridopidine and its salts, and methods for their preparation, can be found in U.S. Patent Application Publications Nos. 2013-0197031, 2016-0166559, and 2016-0095847, the entire contents of each of which are hereby incorporated by reference.

[0097] The present invention also comprises any salt of pridopidine, comprising any pharmaceutically acceptable salt wherein pridopidine has a net charge (positive or negative), and at least one counterion (having a counter charge or a positive charge) is added to pridopidine to form said salt. As used herein, the phrase " Pharmaceutically acceptable salts "This refers to salts of compounds of the present invention that are safe and effective for pharmaceutical use in mammals and have the desired biological activity. Pharmaceutically acceptable salts include salts containing acidic or basic groups present in the compounds of the present invention. Pharmaceutically acceptable acid addition salts include, but are not limited to, hydrochlorides, hydrobroms, hydroiodates, nitrates, sulfates, hydrogen sulfates, phosphates, acid phosphates, isonicotinates, acetates, lactates, salicylates, citrates, D,L-tartrates, L-tartrates, D-tartrates, pantothenates, hydrogen tartrates, ascorbic acid salts, succinates, hemisuccinates, maleates, gentianin salts, and gentian Salts, fumarates, gluconates, glucurons, glycolates, sucrose salts, formates, benzenesulfonates, benzoates, glutamates, malates, methanesulfonates, ethanesulfonates, benzenesulfonates, p-toluenesulfonates, oxalates, toluenesulfonates, naphthalene-2-sulfate, or bis(hydroxynaphthalene) (i.e., 1,1'-methylene-bis(2-hydroxy-3-naphthylcarbamate)). Certain compounds of the present invention can form pharmaceutically acceptable salts with a variety of amino acids. Suitable base salts include, but are not limited to, aluminum, calcium, lithium, magnesium, potassium, sodium, zinc, and diethanolamine salts. For a review of pharmaceutically acceptable salts, see BERGE et al., 66 *Journal of Pharmaceutical Sciences* (J. PHARM. SCI.) 1-19 (1977), which is incorporated herein by reference. In another embodiment, the pridopidine salt of the present invention is a hydrochloride salt.

[0098] Therefore, the present invention also relates to pharmaceutical compositions comprising the pharmaceutical agents of the present invention mixed with pharmaceutically acceptable adjuvants and optionally other therapeutic agents. The adjuvants must be "compatible with the other components of the composition and harmless to the recipient" in the sense that they are " Acceptable ".

[0099] The pharmaceutical composition comprises a pharmaceutical composition suitable for oral, rectal, nasal, topical (including percutaneous, oral, and sublingual), vaginal, or parenteral (including subcutaneous, intramuscular, intravenous, and intradermal) administration or via implantation. The composition may be prepared by any method well known in the pharmaceutical field.

[0100] The pharmaceutical composition comprises a pharmaceutical composition suitable for oral, rectal, nasal, topical (including percutaneous, oral, and sublingual), vaginal, or parenteral (including subcutaneous, intramuscular, intravenous, and intradermal) administration or via implantation. The composition may be prepared by any method well known in the pharmaceutical field.

[0101] Such methods include the step of introducing the associative compound or combination thereof used in this invention with any adjuvants. Adjuvants, also known as auxiliary ingredients, include adjuvants conventional in the art, such as carriers, fillers, binders, diluents, disintegrants, lubricants, colorants, flavorings, antioxidants, and wetting agents.

[0102] Pharmaceutical compositions suitable for oral administration may be presented as discrete dosage units such as pills, tablets, sugar-coated pills, or capsules, or as powders or granules, or as solutions or suspensions. The active ingredient may also be presented as large pills or pastes. The compositions may be further processed into suppositories or enemas for rectal administration.

[0103] The present invention further includes pharmaceutical compositions as described above in combination with packaging materials, and includes instructions for use of the compositions for the purposes described above.

[0104] For parenteral administration, suitable compositions comprise aqueous and non-aqueous sterile injectables. These compositions may be presented in single-dose or multi-dose containers, such as sealed vials and ampoules, and may be stored under lyophilized (freeze-dried) conditions where only a sterile liquid carrier (e.g., water) needs to be added before use. For transdermal administration, gels, patches, or sprays may be considered. Compositions or formulations suitable for pulmonary administration, such as those comprising fine dust or mist for nasal inhalation, may be generated by metered-dose pressurized aerosols, nebulizers, or inhalers.

[0105] The exact dosage and regimen of the composition will necessarily depend on the therapeutic or nutritional effect to be achieved, and may vary depending on the formulation, route of administration, and the age and condition of the individual subject to whom the composition is to be administered.

[0106] As used in this article, the term " treat "" refers to the application of a therapeutic dose of the composition of the present invention, which can effectively improve an undesirable disease or condition, including symptoms associated with the disease or condition, to prevent the manifestation of such disease or condition, including symptoms associated with the onset of the disease or condition, to slow the progression of the disease, to slow the worsening of symptoms, to promote the onset of remission, to slow irreversible damage caused in the progressive chronic phase of the disease, to delay the onset of said progressive phase, to reduce the severity or cure the disease, to improve survival or faster recovery, or to prevent the occurrence of a form of the disease, or a combination of two or more of the above. "" is used for the purposes disclosed herein. Effective amount"The amount is determined by considerations known in the art. The amount must effectively achieve the desired therapeutic effect as described above, which depends particularly on the type and severity of the disease to be treated and the treatment regimen. In some embodiments, compositions comprising pridopidine or a pharmaceutically acceptable salt thereof are administered between 1 mg / day and 400 mg / day, once daily, twice daily, three times daily, or less than once daily. It is generally known that the effective amount depends on a variety of factors, including the ligand's affinity for the receptor, its distribution profile in the body, various pharmacological parameters such as in vivo half-life, undesirable side effects, and, if any, factors such as age and sex."

[0107] In some embodiments, pridopidine is administered at a daily dose between 1 mg / day and 400 mg / day. In some embodiments, pridopidine is administered at a daily dose between 1 mg / day and 300 mg / day. In other embodiments, pridopidine is administered at a daily dose between 1 mg / day and 90 mg / day. In other embodiments, pridopidine is administered at a daily dose between 20 mg / day and 90 mg / day. In yet another embodiment, pridopidine is administered at a daily dose between 45 mg / day and 90 mg / day. In yet another embodiment, pridopidine is administered at a daily dose between 20 mg / day and 50 mg / day. In yet another embodiment, pridopidine is administered at a daily dose between 1 mg / day and 10 mg / day. In yet another embodiment, pridopidine is administered at a daily dose between 10 mg / day and 20 mg / day. In yet another embodiment, pridopidine is administered at a daily dose between 20 mg / day and 30 mg / day. In another embodiment, pridopidine is administered at a daily dose between 30 mg / day and 40 mg / day. In another embodiment, pridopidine is administered at a daily dose between 40 mg / day and 50 mg / day. In another embodiment, pridopidine is administered at a daily dose between 50 mg / day and 60 mg / day. In another embodiment, pridopidine is administered at a daily dose between 60 mg / day and 70 mg / day. In another embodiment, pridopidine is administered at a daily dose between 70 mg / day and 80 mg / day. In another embodiment, pridopidine is administered at a daily dose between 80 mg / day and 90 mg / day. In another embodiment, pridopidine is administered at a daily dose between 90 mg / day and 100 mg / day. In another embodiment, pridopidine is administered at a daily dose between 100 mg / day and 150 mg / day. In another embodiment, pridopidine is administered at a daily dose between 150 mg / day and 200 mg / day. In another embodiment, pridopidine is administered at a daily dose between 200 mg / day and 250 mg / day. In another embodiment, pridopidine is administered at a daily dose between 250 mg / day and 300 mg / day. In another embodiment, pridopidine is administered at a daily dose between 300 mg / day and 350 mg / day. In another embodiment, pridopidine is administered at a daily dose between 350 mg / day and 400 mg / day.

[0108] Example

[0109] Example 1: Pridolpiride reduces mHtt-induced ER stress

[0110] ER stress was measured in STHdhQ7 / 7 cells transfected with mutant Htt96Q-mCherry (amplified, mut-Htt), which showed visible mut Htt-mCherry aggregates. The appearance of mut Htt-mCherry aggregates was associated with high levels of H2a-GFP accumulation, an indicator of ER stress. Figure 1 STHdhQ7 / 7 cells expressing Htt20Q-mCherry (wt HTT) or Htt96Q-mCherry (mutHTT) without visible aggregates showed low levels of H2a-GFP (without ER stress).

[0111] Pridolpicine significantly reduced H2a-GFP accumulation in muHTT aggregate-positive cells in a dose-dependent manner, without altering H2a-GFP levels in cells without mHTT aggregates or in cells expressing Htt20Q-mCherry. Figure 2 ).

[0112] Therefore, pridopidine reduces Htt-induced ER stress in a dose-dependent manner.

[0113] Viral infection-induced ER stress leads to eIF2α phosphorylation, which inhibits overall translation in cells but increases the expression of UPR-related genes such as ATF4, CHOP, GADD-34, ATF6, and Xbp1 (Bechill et al. 2008; K. Liao et al. 2016).

[0114] Example 2: Pridolpiride lowers eIF2α-p levels

[0115] The effects of pridopidine on ER stress were investigated by assessing the phosphorylation level of the translation initiation factor eIF2α. eIF2α phosphorylation is a marker of ER stress response. Figure 3 and 4 In comparison with cells expressing WT Htt (Htt20Q), HEK293 cells expressing mutant Htt protein (Htt96Q) showed 1.7-fold and 3.5-fold increased eIF2α-phosphorylation (eIF2α-p), respectively. At 8 hours ( Figure 3 ) and 24 hours ( Figure 4 When pridopidine treatment induced a significant dose-dependent decrease in eIF2α-phosphorylation (eIF2α-P / eIF2α ratio), this indicates a reduction in cellular ER stress.

[0116] The effect of pridopidine on ER stress was evaluated in cells where ER stress was not induced by mutant huntingtin protein, but by the potent ER stress inducer carotenoid. HEK293 cells transfected with Htt20Q-mCherry (wt HTT) were treated with 2 μg / ml carotenoid to induce ER stress. After 8 hours of treatment, pridopidine (3 μM) caused a decrease in eIF2α-p (the eIF2α-p / eIF2α ratio). Figure 5 This indicates that pridopidine reduces ER stress, regardless of the underlying cause.

[0117] Example 3: Pridopidine reduces eIF2α-p (ER stress) through an S1R-dependent mechanism.

[0118] To assess whether the effect of pridopidine on ER stress is S1R-mediated, eIF2α-phosphorylation levels were evaluated in HEK293 cells genetically deleting S1R using CRISPR / Cas9 (S1R- / -). ER stress was induced by transfection with the mutant Htt (Htt96Q). In S1R+ / + cells, Htt96Q increased ER stress as measured by a two-fold increase in eIF2α-P levels. Pridopidine treatment (0.3 μM and 3 μM) significantly reduced eIF2α-P levels. Figure 6 The genetic deletion of S1R (S1R- / -) also contributes to the increase in eIF2α-P levels, suggesting that S1R is involved in mediating ER stress levels. Treatment of S1R- / - cells transfected with Htt96Q with pridopidine had no effect on eIF2α-P levels, indicating that the effect of pridopidine is finely mediated through S1R.

[0119] In response to coronavirus infection in multiple cell models (i.e., infectious bronchitis virus (IBV) and mouse hepatitis virus (MHV)), the levels of UPR pathway proteins ATF4, CHOP, GADD-34, ATF6, and Xbp1 were upregulated in these cell models (Y. Liao et al. 2013; Bechill et al. 2008). Bioinformatics analyses predicted similar effects from SARS-CoV-2 (Nabirotchkin et al. 2020).

[0120] Example 4: Pridolpiride lowers the levels of UPR PERK pathway markers.

[0121] ATF4 translation increases in response to ER stress and eIF2α phosphorylation and is part of the UPR pathway, triggering a cascade of transcriptional responses including increased CHOP and GADD-34 translation. The effects of pridopidine on ATF4, CHOP, and GADD-34 protein levels were evaluated in HEK293 cells induced by ER stress from mutant Htt (Htt96Q). Compared to cells transfected with wt Htt (Htt20Q), Htt96Q-induced ER stress increased ATF4 levels by 4.5-fold (…). Figure 7A Increase CHOP level by 5 times ( Figure 7B ), and increased GADD-34 levels by 7 times ( Figure 7C Treatment with pridopidine reduced ATF4, CHOP, and GADD-34 to normal wt levels.

[0122] Example 5: Pridolpiride reduces the levels of ATF6 and IRE markers in the UPR pathway arm.

[0123] ER stress in HD cells was evident, as measured by increases in two additional UPR pathways: the ATF6 pathway and the IRE1 pathway (increased Xbp1 splicing). In HEK293 cells, ATF6 levels were undetectable in Htt20Q-transfected cells and therefore increased in cells transfected with the mutant Htt96Q. Treatment with pridopidine (3 μM) reduced ATF6 levels by 35% ( Figure 8 In the IRE1 arm of the UPR pathway, Xbp1 mRNA levels increased by approximately 60%. Treatment with pridopidine (3 μM) significantly reduced Xbp1 mRNA levels by 25%. Figure 9 These data indicate that pridopidine reduces the activation of all three arms of the UPR pathway induced by ER stress.

[0124] Example 6: Pridolpiride reduces mitochondrial ROS production.

[0125] HD mouse neurons exhibit increased sensitivity to oxidative attack, leading to increased levels of reactive oxygen species (ROS) and insufficient antioxidant response. Striatal neurons from YAC128 HD mice were treated with 1 μM pridopidine before ROS production was induced by the mitochondrial respiratory inhibitor antimycin A (Ant A). Ant A increased ROS production approximately two-fold in YAC128 neurons. Pridopidine (1 μM) showed a robust and significant reduction in mitochondrial-generated ROS, returning to normal levels. Figure 10 ).

[0126] ATF4 and CHOP are involved in the regulation of mitochondrial function (Šileikytė and Forte 2019). By influencing ATF4 and CHOP levels, as indicated by bioinformatics analysis (Nabirotchkin et al. 2020), SARS-CoV2 can disrupt this regulation to prevent apoptosis, similar to previously described coronaviruses that have been shown to interfere with mitochondrial function (Kim et al. 2018).

[0127] Example 7: SARS-CoV-2 infection reduces mitochondrial membrane potential

[0128] The Nsp10 protein of SARS-CoV interacts directly with cytochrome oxidase II (a component of mitochondrial complex IV). This interaction leads to decreased cytochrome oxidase activity and a loss of mitochondrial inner membrane potential. In summary, SARS-CoV-2 affects the mitochondrial redox enzyme system and reduces mitochondrial membrane potential (Q. Li et al. 2005).

[0129] Example 8: Priligy increases mitochondrial membrane potential

[0130] The role of S1R in regulating mitochondrial membrane potential (MMP) was investigated in striatal neurons from wild-type (WT) controls and YAC128 HD mice. HD neurons showed reduced MMP compared to WT neurons. In WT neurons, pridopidine caused a significant increase in 1 μM MMP, with a trend toward an increase of 0.1 μM MMP. In HD neurons, which showed a 25% reduction in MMP compared to WT neurons, both doses of pridopidine caused a significant increase in MMP. Therefore, pridopidine rescues impaired membrane potential (MMP). Figure 11 ).

[0131] Example 9: The effect of pridopidine on mitochondrial membrane potential is mediated by S1R.

[0132] To confirm that the effect of pridopidine is S1R-mediated, S1R was knocked down in HD lymphoblasts, resulting in a reduction of approximately 83% in protein levels. H2O2 treatment significantly reduced MMPs in both S1R+ / + cells and S1R-KD cells, by 25% and 75%, respectively. Pridopidine treatment (5 μM) completely restored MMPs in S1R+ / + cells but not in S1R-KD cells. Therefore, pridopidine has a protective effect against MMPs. In cells with reduced S1R levels (p < 0.001), the effect of pridopidine on H2O2-induced MMP reduction was eliminated, indicating that the effect of pridopidine is S1R-dependent. Figure 12 ).

[0133] References cited in this application

[0134] Allahtavakoli, Mohammad, and Bevyn Jarrott. 2011. “Sigma-1 Receptor Ligand PRE-084 Reduced Infarct Volume, Neurological Deficits, Pro-Inflammatory Cytokines and Enhanced Anti-Inflammatory Cytokines after Embolic Stroke in Rats.” Brain Research Bulletin. https: / / doi.org / 10.1016 / j.brainresbull.2011.03.019.

[0135] Alon, Assaf, Hayden R. Schmidt, Michael D. Wood, James J. Sahn, Stephen F. Martin, and Andrew C. Kruse. 2017. “Identification of the Gene That Codes for the Σ2 Receptor.” Proceedings of the National Academy of Sciences of the United States of America. https: / / doi.org / 10.1073 / pnas.1705154114.

[0136] Bechill, John, Zhongbin Chen, Joseph W. Brewer, and Susan C. Baker. 2008. "Coronavirus Infection Modulates the Unfolded Protein Response and Mediates Sustained Translational Repression." Journal of Virology. https: / / doi.org / 10.1128 / jvi.00017-08.

[0137] Cava, Claudia, Gloria Bertoli, and Isabella Castiglioni. 2020. “In Silico Discovery of Candidate Drugs against Covid-19.” Viruses. https: / / doi.org / 10.3390 / v12040404.

[0138] Chan, Ching-Ping, Kam-Leung Siu, King-Tung Chin, Kwok-Yung Yuen, Bojian Zheng, and Dong-Yan Jin. 2006. “Modulation of the Unfolded Protein Response by the Severe Acute Respiratory Syndrome Coronavirus Spike Protein.” Journal of Virology https: / / doi.org / 10.1128 / jvi.00659-06.

[0139] Chen, Chia-Yen, Yueh-Hsin Ping, Hsin-Chen Lee, Kuan-Hsuan Chen, Yuan-Ming Lee, Yu-Juin Chan, Te-Cheng Lien, et al., 2007. "Open Reading Frame 8a of the Human Severe Acute Respiratory Syndrome Coronavirus Not Only Promotes Viral Replication but Also Induces Apoptosis." *The Journal of Infectious Diseases*, https: / / doi.org / 10.1086 / 519166.

[0140] Christ, Maximilian, Heike Huesmann, Heike Nagel, Andreas Kern, and Christian Behl. 2019. “Sigma-1 receptor activation induces autophagy and increases proteostasis capacity in vitro and in vivo.” Cells. https: / / doi.org / 10.3390 / cells8030211.

[0141] DeDiego, Marta L., Jose L. Nieto-Torres, Jose M. Jiménez-Guardeño, Jose A. Regla-Nava, Enrique Álvarez, Juan Carlos Oliveros, Jincun Zhao, Craig Fett, Stanley Perlman, and Luis Enjuanes. 2011. “Severe Acute Respiratory Syndrome Coronavirus Envelope Protein Regulates Cell Stress Response and Apoptosis.” PLoS Pathogens. https: / / doi.org / 10.1371 / journal.ppat.1002315.

[0142] Delprat, Benjamin, Lucie Crouzier, Tsung Ping Su, and Tangui Maurice. 2020. “At the Crossing of ER Stress and MAMs: A Key Role of Sigma-1 Receptor?” In Advances in Experimental Medicine and Biology. https: / / doi.org / 10.1007 / 978-3-030-12457-1_28.

[0143] Fung, To S. and Ding X. Liu. 2014. “Coronavirus Infection, ER Stress, Apoptosis and Innate Immunity.” Frontiers in Microbiology. https: / / doi.org / 10.3389 / fmicb.2014.00296.

[0144] Gassen, Nils C., Daniela Niemeyer, Doreen Muth, Victor M. Corman, Silvia Martinelli, Alwine Gassen, Kathrin Hafner, et al. 2019. “SKP2 Attenuates Autophagy through Beclin1-Ubiquitination and Its Inhibition Reduces MERS-Coronavirus Infection.” Nature Communications. https: / / doi.org / 10.1038 / s41467-019-13659-4.

[0145] Gordon, David E, Gwendolyn M Jang, Mehdi Bouhaddou, Jiewei Xu, Kirsten Obernier, Matthew J O'; Meara, Jeffrey Z Guo, et al. 2020. “A SARS-CoV-2-Human Protein-Protein Interaction Map Reveals Drug Targets and Potential Drug-Repurposing.” BioRxiv. https: / / doi.org / 10.1101 / 2020.03.22.002386.

[0146] Harapan, Harapan, Naoya Itoh, Amanda Yufika, Wira Winardi, Synat Keam, Heyhpeng Te, Dewi Megawati, Zinatul Hayati, Abram L. Wagner, and Mudatsir Mudatsir. 2020. “Coronavirus Disease 2019 (COVID-19): A Literature Review.” Journal of Infection and Public Health. https: / / doi.org / 10.1016 / j.jiph.2020.03.019.

[0147] Johnston, Tom H., Michal Geva, Lilach Steiner, Aric Orbach, Spyros Papapetropoulos, Juha Matti Savola, Ian J. Reynolds et al. 2019. “Pridopidine, a Clinic-Ready Compound, Reduces 3,4-Dihydroxyphenylalanine-Induced Dyskinesia in Parkinsonian Macaques.” Movement Disorders 34(5): 708–16. https: / / doi.org / 10.1002 / mds.27565.

[0148] Katnik, C., Y. Herrera, KR Pennypacker, J. Cuevas, and WR Guerrero. 2006. “Sigma-1 Receptor Activation Prevents Intracellular Calcium Dysregulation in Cortical Neurons During Vitro Ischemia.” Journal of Pharmacology and Experimental Therapeutics 319(3): 1355–65. https: / / doi.org / 10.1124 / jpet.106.107557.

[0149] Kim, Seong Jun, Dae Gyun Ahn, Gulam H. Syed, and Aleem Siddiqui. 2018. “The Essential Role of Mitochondrial Dynamics in Antiviral Immunity.” Mitochondrion. https: / / doi.org / 10.1016 / j.mito.2017.11.007.

[0150] Li, Qihan, Lichun Wang, Chenghong Dong, Yanchun Che, Li Jiang, Longding Liu, Hongling Zhao, et al., 2005. “The Interaction of the SARS Coronavirus Non-Structural Protein 10 with the Cellular Oxido-Reductase System Causes an Extensive Cytopathic Effect.” Journal of Clinical Virology, https: / / doi.org / 10.1016 / j.jcv.2004.12.019.

[0151] Li, Shumin, Lixia Yuan, Guo Dai, Rui Ai Chen, Ding Xiang Liu, and To SingFung. 2020. “Regulation of the ER Stress Response by the Ion Channel Activity of the Infectious Bronchitis Coronavirus Envelope Protein Modulates Virion Release, Apoptosis, Viral Fitness, and Pathogenesis.” Frontiers in Microbiology https: / / doi.org / 10.3389 / fmicb.2019.03022.

[0152] Liao, Ke, Minglei Guo, Fang Niu, Lu Yang, Shannon E. Callen, and Shilpa Buch. 2016. “Cocaine-Mediated Induction of Microglial Activation Involves the ER Stress-TLR2 Axis.” Journal of Neuroinflammation, 1–16. https: / / doi.org / 10.1186 / s12974-016-0501-2.

[0153] Liao, Y., TS Fung, M. Huang, SG Fang, Y. Zhong, and DX Liu. 2013. "Upregulation of CHOP / GADD153 during Coronavirus Infectious Bronchitis Virus Infection Modulates Apoptosis by Restricting Activation of the Extracellular Signal-Regulated Kinase Pathway." Journal of Virology https: / / doi.org / 10.1128 / jvi.00626-13.

[0154] Longhitano, Lucia, Carlo Castruccio Castracani, Daniele Tibullo, Roberto Avola, Maria Viola, Giuliano Russo, Orazio Prezzavento et al. 2017. “Sigma-1 and Sigma-2 receptor ligands induce apoptosis and autophagy but have an opposite effect on cell proliferation in uveal melanoma.” Oncotarget. https: / / doi.org / 10.18632 / oncotarget.19556.

[0155] Maurice, Tangui, Masayuki Hiramatsu, Jiro Itoh, Tsutomu Kameyama, Takaaki Hasegawa, and Toshitaka Nabeshima. 1994. “Behavioral Evidence for a Modulating Role of σ Ligands in Memory Processes. I. Attenuation of Dizocilpine (MK-801)-Induced Amnesia.” Brain Research 647 (1): 44–56. https: / / doi.org / 10.1016 / 0006-8993(94)91397-8.

[0156] Nabirotchkin, Serguei, Alex E Peluffo, Jan Bouaziz, and Daniel Cohen. 2020. "Focusing on the Unfolded Protein Response and Autophagy Related Pathways to Reposition Common Approved Drugs against COVID-19." Preprints. https: / / doi.org / 10.20944 / preprints202003.0302.v1.

[0157] Ricardo J Jose and Ari Manuel. 2020. “COVID-19 Cytokine Storm: The Interplay between Inflammation and Coagulation.” The Lancet Respiratory Medicine.

[0158] Šileikytė, Justina, and Michael Forte. 2019. “The Mitochondrial Permeability Transition in Mitochondrial Disorders.” Oxidative Medicine and Cellular Longevity. https: / / doi.org / 10.1155 / 2019 / 3403075.

[0159] Starkov, Anatoly A. 2008. “The Role of Mitochondria in Reactive Oxygen Species Metabolism and Signaling.” Annals of the New York Academy of Sciences. https: / / doi.org / 10.1196 / annals.1427.015.

[0160] Tesei, Anna, Michela Cortesi, Sara Pignatta, Chiara Arienti, Giulio Massimo Dondio, Chiara Bigogno, Alessio Malacrida, et al. 2019. “Anti-Tumor Efficacy Assessment of the Sigma Receptor Pan Modulator RC-106. A Promising Therapeutic Tool for Pancreatic Cancer.” Frontiers in Pharmacology. https: / / doi.org / 10.3389 / fphar.2019.00490.

[0161] Tesei, Anna, Michela Cortesi, Alice Zamagni, Chiara Arienti, Sara Pignatta, Michele Zanoni, Mayra Paolillo, et al. 2018. “Sigma Receptors as Endoplasmic Reticulum Stress 'Gatekeepers' and Their Modulators as Emerging New Weapons in the Fight against Cancer.” Frontiers in Pharmacology https: / / doi.org / 10.3389 / fphar.2018.00711.

[0162] Wang, Jing-Zhang, Rui-Ying Zhang, and Jing Bai. 2020. “An Anti-Oxidative Therapy for Ameliorating Cardiac Injuries of Critically Ill COVID-19-Infected Patients.” International Journal of Cardiology. https: / / doi.org / 10.1016 / j.ijcard.2020.04.009.

[0163] Weng, Tzu Yu, Shang Yi Anne Tsai and Tsung Ping Su. 2017. “Roles of Sigma-1 Receptors on Mitochondrial Functions Relevant to Neurodegenerative Diseases.” Journal of Biomedical Science 24 (1): 1–14. https: / / doi.org / 10.1186 / s12929-017-0380-6.

[0164] Zhao, Jing, Yonju Ha, Gregory I. Liou, Graydon B. Gonsalvez, Sylvia B. Smith, and Kathryn E. Bollinger. 2014. “Sigma Receptor Ligand, (+)-Pentazocine, Suppresses Inflammatory Responses of Retinal Microglia.” Investigative Ophthalmology and Visual Science. https: / / doi.org / 10.1167 / iovs.13-12823.

Claims

1. Use of a composition comprising pridopidine or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for use against SARS coronavirus 2 infection, wherein the composition is administered to a subject when the medicament is used.

2. The use according to claim 1, wherein the use comprises treating COVID-19 caused by SARS coronavirus 2, or reducing the incidence of COVID-19 caused by SARS coronavirus 2.

3. The use according to claim 1 or 2, wherein the medicament further reduces ER stress in the subject.

4. The use according to claim 2, wherein the symptoms of COVID-19 comprise kidney failure, fever, tiredness, dry cough, pain, stuffy nose, runny nose, sore throat, diarrhea, or a combination thereof.

5. Use of a composition comprising pridopidine or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for reducing endoplasmic reticulum stress (ER stress) due to SARS coronavirus 2, wherein the composition is administered to a subject when the medicament is used.

6. The use according to claim 5, wherein the use comprises treating COVID-19 caused by SARS coronavirus 2, or reducing the incidence of COVID-19 caused by SARS coronavirus 2.

7. The use according to any of the preceding claims, wherein the composition is administered by systemic administration when the medicament is used.

8. The use according to claim 7, wherein the composition is administered by oral administration.

9. The use according to claim 1, wherein the composition is formulated as an inhalable powder, an injection, a gel, a capsule, an eye drop, or a tablet.

10. The use according to claim 1 or claim 5, wherein the composition is administered once a day, twice a day, three times a day, or less than once a day when the medicament is used.

11. The use according to claim 10, wherein the composition is administered in one dose per day, two doses per day, or three doses per day.

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