Platform for screening schizophrenia drugs and application thereof

Abstract

The invention discloses a platform for screening schizophrenia drugs and application of the platform. Based on the development of research on schizophrenia in recent years, the platform develops a hypothesis about glutamic acid and cerebral blood flow defects, constructs a schizophrenia drug screening model, and verifies the schizophrenia drug screening model by using clinical antipsychotic drugs. The method not only is beneficial to deep exploration of pathogenesis and neuroimaging characteristics of complex schizophrenia by human beings, but also can be used for evaluating the curative effect of existing clinical treatment drugs, and combines scientific research value and clinical application prospect.

Description

Technical Field

[0001] This application relates to the field of psychopharmacological drug screening technology, specifically to a platform for screening drugs for schizophrenia and its application. Background Technology

[0002] Schizophrenia is a chronic, severe mental disorder characterized by positive symptoms (delusions, hallucinations), negative symptoms (emotional blunting), and cognitive impairment. In 2025, the World Health Organization announced a global prevalence of schizophrenia of 0.32%, while in my country this figure reached 0.61%, far exceeding the global average. Current research indicates that the onset of schizophrenia may be related to multiple factors, including genetics, abnormalities in brain structure and function, and acquired environmental factors (childhood trauma, pregnancy problems), but its exact pathogenesis is not fully understood and remains under investigation. Schizophrenia commonly occurs in adolescence and middle age, with similar prevalence in men and women, but men generally experience earlier onset and a more severe course of illness.

[0003] Prevention of schizophrenia primarily relies on early identification and intervention, supplemented by strengthening the community mental health service system, popularizing mental health education, and guiding the public to form rational scientific understanding to promote social recovery. In terms of treatment, medication remains the core approach, especially antipsychotic drugs, whose mechanism of action mainly involves regulating the dysfunction of neurotransmitters such as dopamine in the brain to alleviate symptoms. The principle of drug treatment is to achieve the goal of stabilizing the condition more effectively with the lowest possible dose. Antipsychotic drugs are generally classified into first-generation "typical" and second-generation "atypical" antipsychotics. Common first-generation "typical" drugs include chlorpromazine, perphenazine, and penfluridone; although they are quite effective in controlling positive symptoms, they have significant side effects. Second-generation antipsychotics, while improving positive symptoms, also have some effect on negative symptoms; common drugs include aripiprazole, clozapine, lurasidone, olanzapine, paliperidone, quetiapine, risperidone, amisulpride, and budesonide. Clozapine has been shown to be effective not only in treating patients with treatment-resistant schizophrenia who are unresponsive to other antipsychotic drugs, but also in reducing the risk of suicide.

[0004] In the treatment of schizophrenia, drug therapy has always held a dominant position. However, to date, existing antipsychotic drugs still face multiple challenges, including limited efficacy and significant adverse reactions, especially lacking ideal drugs that are both highly effective and have low toxicity. This situation highlights the urgency of constructing efficient drug screening models, which is also an important topic for in-depth research into the mechanisms of mental illness. Currently, based on the clinical symptoms of schizophrenia, researchers at home and abroad mostly use phenotypes such as hyperkinesis and stereotyped behaviors as evaluation indicators. However, these behaviors lack disease specificity, are difficult to reflect pathological mechanisms, and have limited predictive value for clinical translation. Therefore, establishing a highly representative and specific assessment model or screening method for schizophrenia has become an important scientific problem that urgently needs to be solved in this field.

[0005] The development of antipsychotic drugs began with an accidental discovery in the 1950s. Since the 1960s, research has gradually established the dopamine hypothesis as the dominant theory. As the first widely accepted neurobiochemical pathological hypothesis for schizophrenia, this hypothesis posits that an imbalance in the brain's dopamine system—especially hyperfunction caused by excessive dopamine release—is the main mechanism triggering positive symptoms of schizophrenia. However, the dopamine hypothesis has significant limitations: it cannot explain the pathological mechanisms of negative symptoms, nor has it proven its clinical effectiveness, thus limiting its broad applicability in clinical treatment. In the late 1980s, the discovery that N-methyl-D-aspartate (NMDA) receptor antagonists could induce schizophrenic symptoms, including negative symptoms and cognitive deficits, gave rise to the glutamate hypothesis. This hypothesis proposes that glutamatergic neurotransmission disorders, particularly NMDA receptor dysfunction, may be a pathological explanation for the more comprehensive symptoms of schizophrenia.

[0006] In recent years, neuroimaging studies have revealed a significant link between schizophrenia and changes in cerebral hemodynamics. Cerebral blood flow (CBF)—the amount of blood passing through 100 grams of brain tissue per unit time—is a key indicator reflecting neural activity and energy metabolism, and its abnormal changes have become a novel biomarker for schizophrenia. According to the principle of neurovascular coupling, increased neuronal activity in a brain region triggers increased local metabolic demand, leading to increased cerebral blood perfusion in the corresponding area. However, in disease models, despite an increased cerebral metabolic rate, insufficient energy reserves result in inadequate perfusion, thus manifesting as functional impairment.

[0007] Based on the dopamine hypothesis, the glutamate hypothesis, and abnormal cerebral blood flow perfusion, and combined with preclinical and clinical trial data, this study systematically elucidates for the first time the interaction mechanism between glutamate metabolism and cerebral blood flow regulation, providing an important physiological basis and research evidence for this invention. Summary of the Invention

[0008] The main objective of this invention is to overcome the shortcomings of existing technologies and provide a model or drug screening platform for screening drugs for schizophrenia, as well as a method for screening drugs for treating mental illness using this platform. The model of this invention does indeed exhibit specificity for human schizophrenia, and the schizophrenia drug screening platform built based on this model can be used to screen new drugs and develop other treatment methods.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a model for screening drugs for schizophrenia, the drug screening model including the steps of detecting (or collecting) changes in brain glutamate and / or its metabolites levels before and after drug administration, as well as changes in cerebral blood flow.

[0010] Furthermore, this invention provides a model for screening drugs for schizophrenia, which uses proton magnetic resonance spectroscopy (PMR) before and after drug administration. 1 H-MRS technology is used to detect (or collect) changes in glutamate and / or its metabolites in the brain of experimental animals, and combined with arterial spin labeling imaging (ASL) technology to assess changes in cerebral blood flow in the anterior cingulate cortex (ACC) and striatum, thereby evaluating the effect of drug intervention; preferably, the experimental animals are selected from mammals, preferably including humans or mice; preferably, the schizophrenia is treatment-resistant schizophrenia, which has higher screening specificity and application value.

[0011] Furthermore, the present invention provides a model for screening drugs for schizophrenia, wherein the glutamate metabolite is selected from glutamine.

[0012] Furthermore, the present invention provides a model for screening drugs for schizophrenia, the model comprising the step of administering a positive control compound to experimental animals, wherein the positive control compound is preferably selected from clozapine.

[0013] Furthermore, the present invention provides a model for screening drugs for schizophrenia, the model including the steps of detecting (or collecting) data on changes in striatal glutamate and striatal blood flow during the treatment period after administering the drug to experimental animals.

[0014] Furthermore, the present invention provides a model for screening drugs for schizophrenia, the model including the steps of statistically analyzing the changes in striatal glutamate and striatal blood flow in experimental animals after administering the drug to be evaluated and a positive control compound, wherein the statistical analysis method is a multilevel linear regression model.

[0015] Furthermore, the present invention provides the application of the above-mentioned model for screening drugs for schizophrenia in evaluating the efficacy of candidate compounds in treating schizophrenia.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. Based on recent research progress in schizophrenia, this invention establishes a drug screening model for schizophrenia based on the glutamate hypothesis and the hypothesis of abnormal cerebral blood flow in schizophrenia. The model is then validated using clinical antipsychotic drugs. The results show a positive correlation between changes in striatal glutamate and striatal blood flow after patients take a positive control drug. The dual-indicator joint detection test is beneficial for screening new antipsychotic drugs from clinical candidate compounds and reduces the risk of false positives.

[0017] 2. The method for establishing an experimental mouse model of schizophrenia in this invention is not only beneficial for human research on the complex pathogenesis of schizophrenia, but can also be used to test the efficacy of existing clinical schizophrenia treatment drugs; more importantly, it can be used to screen new anti-schizophrenia drugs using the biochemical pathological-neuroimaging biological markers and pharmacological models based on schizophrenia-related factors established by the inventors. Attached Figure Description

[0018] Figure 1 This study analyzed the correlation between changes in brain glutamate metabolism and cerebral blood flow (CBF) during clozapine treatment of treatment-resistant schizophrenia (TRS) (N=20). Region of interest (ROI) analysis showed a significant positive correlation between changes in striatal glutamate and changes in striatal cerebral blood flow (CBF). Scatter plots represent individual values. A straight line represents the best-fit line, and the gray area represents the 95% confidence interval. The percentage change in positivity (%) indicates an increase in values ​​during treatment. CBF, cerebral blood flow; Glu, glutamate.

[0019] Figure 2 Association analysis of striatal glutamate changes and cortical cerebral blood flow changes during clozapine treatment (N=20) revealed significant clusters in the highlighted brain regions (MNI (x, y, z) = -42, -66, 44; p < 0.05 family error correction), indicating a significant positive correlation between striatal glutamate changes and CBF changes in specific cortical regions; CBF is cerebral blood flow.

[0020] Figure 3To investigate the association between ACC glutamate and cerebellar CBF after 12 weeks of clozapine treatment (N=20), the highlighted brain regions showed significant clusters (MNI (x, y, z) = -18, -78, -38; p < 0.05, family error correction), indicating a significant positive correlation between changes in ACC glutamate levels and changes in CBF in specific cerebellar regions; CBF stands for cerebral blood flow. Detailed Implementation

[0021] To make the technical means, key innovations, intended purpose, and technical advantages of this invention clearer, the invention will now be further described in detail with reference to specific embodiments.

[0022] Research Design and Participants: This study received ethical approval from the Southeast London Research Ethics Committee, and all participants provided written informed consent. Participants were recruited from inpatient and outpatient services in South London, Maudsley, and the Oxleas NHS Foundation Trust. Inclusion criteria required participants to be ≥18 years old, meet the diagnostic criteria for schizophrenia (F20) or schizoaffective disorder (F25) according to the International Classification of Diseases, 10th Revision (ICD-10); have no prior history of clozapine use; have received the recommended dose (25 mg / day, divided into two doses) for ≥6 weeks each time, and have been referred to their psychiatrist for clozapine treatment.

[0023] Clinical measurement method Medical history was obtained through clinical interviews and medical records. Symptom severity was assessed using the Positive and Negative Syndrome Scale (PANSS) at each follow-up MRI examination, and social and occupational functioning was assessed using the Global Assessment of Functioning (GAF). Blood samples were collected to monitor clozapine plasma concentrations to determine if the treatment threshold of 350 ng / ml had been reached, at weeks 6, 8 (if not reached by week 6), and 12.

[0024] 1 H-MRS collection and quantification (glutamate and Glx (total glutamate and glutamine levels)) All neuroimaging data were acquired at the Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, using a Discovery MR750 3T MRI system manufactured by General Electric, using two time points (“baseline” and “week 12”). 1H-MRS glutamate and Glx levels were acquired using point-resolved spectroscopy (PRESS) combined with chemical shift selective (CHESS) pulses to acquire signals (TE = 30 ms in ACC, TE = 35 ms in striatum, TR = 3000 ms, average number of acquisitions = 96). An unsuppressed water reference spectrum was acquired for each acquisition (average number of acquisitions = 16) for eddy current correction and water peak quantification. The voxel settings for the regions of interest (ROI) were as follows: (1) ACC center (20 × 20 × 20 mm); (2) in the right striatum (20 × 20 × 20 mm, mainly covering the head of the right striatum, with the lower end of the voxel located on the dorsal side of the anterior commissure to include the maximum amount of gray matter and the minimum amount of cerebrospinal fluid).

[0025] Spectral data were analyzed using LCMode software version 6.3-0I. The concentrations of glutamate and its metabolites were corrected for voxel tissue composition using the following formula: Metabolite Corrected = Metabolite Concentration × (WM + 1.21GM + 1.55CSF) / (WM + GM), where WM, GM, and CSF represent the white matter, gray matter, and cerebrospinal fluid within the voxel, respectively.

[0026] Collection and quantification of cerebral blood flow. Pseudo-continuous arterial spin labelling (pCASL) images were acquired using a 3D fast spin echo spiral multiple read sequence. The acquisition parameters were as follows: labeling duration = 1800 ms, post-labeling delay = 2025 ms, inversion time (TI) = 1525 ms, repeat time (TR) = 4968 ms, echo time (TE) = 11.09 ms, field of view (FoV) = 240 mm, flip angle = 111°, and a total of 8 consecutive slices were acquired, each 3 mm thick, to achieve whole-brain coverage. The echo train length (ETL) was 64. Simultaneously, proton density (PD) images were acquired using the same sequence for reference calibration to quantify blood flow in physiological units (ml blood / 100 g tissue / min) in accordance with the latest guidelines for CBF calculation. The total acquisition time for the complete ASL pulse sequence and proton density images was 7 minutes. Structural magnetic resonance imaging data were obtained by preparing a fast gradient echo sequence using three-dimensional T1-weighted magnetization (TI = 400 ms, TR = 7.31 ms, TE = 3.02 ms, voxel size = 1.05 × 1.05 × 1.2 mm3, FoV = 270 mm, flip angle = 11°).

[0027] The obtained CBF images were preprocessed using the ASL Automated Processing Software (ASAP) toolbox in statistical software (SPM-12, Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London (UCL), UK, http: / / www.fil.ion.ucl.ac.uk / spm / software / spm12 / ) to prepare for ROI and voxel-level analyses. For the primary analysis, ROI masks for the bilateral anterior cingulate cortex and striatum were defined using WFUPickAtlas ('ACC' and 'striatum') in SPM-12. For confirmatory analyses, due to... 1 H-MRS data were acquired only in the right striatum, therefore a separate ROI mask targeting only the right striatum was generated from the bilateral mask, and, in order to specifically extract the area located in... 1 Specific CBF values ​​in H-MRS voxels, from the anterior cingulate cortex and right striatum in SPM-12. 1 H-MRS voxels generated two additional voxel-level masks. The mean CBF value for each mask was extracted using the ASAP toolbox. The mean global CBF value was extracted from the group-level gray matter mask to investigate global differences and account for inter-individual differences in global perfusion.

[0028] Statistical analysis At the whole-brain level, further voxel-level supplementary analyses were performed using SPM-12 software. First, CBF difference maps (follow-up images minus baseline images) were calculated for each subject using ImCalc to assess changes in cerebral blood flow during clozapine treatment. Subsequently, voxel-level multiple regression analysis (ANOVA) was performed using glutamate (or Glx) changes as regression variables. To explore the relationship between baseline and week 12 glutamate and CBF, individual glutamate concentrations were also included as regression variables in the voxel-level ANOVA model, with consideration given to whether overall CBF was considered as an irrelevant covariate. The statistical significance threshold was p < 0.05, and family error rate (FWE) correction was applied.

[0029] Clinical data In Python version 3.12.6, paired t-tests with a two-tailed α of 0.05 were used to determine intra-subject changes in symptom severity and function following clozapine treatment.

[0030] Integration 1 H-MRS and pCASL data Region of Interest Analysis To examine the normality of cerebral blood flow (CBF) and proton magnetic resonance spectroscopy (¹H-MRS) parameters, the Shapiro-Wilk test was used. Correlation between variables was assessed using Pearson correlation analysis, focusing on the correlations between glutamate, the complex metabolite Glx, and CBF in the anterior cingulate cortex (ACC) or striatum at baseline, week 12, and during the 12-week changes. To control for multiple comparisons, Bonferroni correction was applied to both parameters in the two brain regions, with a significance level adjusted to p = 0.0125 (0.05 / 4). In some auxiliary analyses, total CBF was used as a covariate for control.

[0031] An exploratory analysis of the relationship between glutamate metabolites, regional CBF, and symptoms using stratified linear regression was completed. The following relationships were examined using stratified models: a) the relationship between changes in glutamate (or Glx) and CBF and improvement in overall symptom severity, and b) the relationship between baseline glutamate (or Glx) and CBF and subsequent improvement in symptom severity. For analysis a), changes in global CBF were entered in step 1 (Model 1, control variables); changes in glutamate metabolites and CBF values ​​were used as predictors in step 2, while controlling for changes in global CBF (Model 2); and the interaction term between changes in glutamate metabolites and CBF values ​​was entered in step 3 (Model 3). Similarly, for analysis b), baseline global CBF was entered in step 1 (Model 1, control variables); baseline glutamate metabolites and baseline CBF values ​​were used as predictors in step 2, while controlling for baseline global CBF (Model 2); and the interaction term between baseline glutamate metabolites and CBF values ​​was entered in step 3 (Model 3). The threshold for statistical significance was p < 0.05.

[0032] Experimental results: Table 1. Relationship between CBF and ACC and glutamate metabolites in the striatum.

[0033]

[0034] ACC, anterior cingulate cortex; CBF, cerebral blood flow; Glx, glutamate + glutamine complex.

[0035]

[0036] This study provides new data on the local relationship between ACC and striatal glutamate metabolites and cerebral perfusion in TRS participants during clozapine treatment. Our main finding is that changes in striatal glutamate and blood flow were positively correlated during clozapine treatment, while no such relationship was found in ACC.

[0037] The positive association between decreased striatal glutamate and decreased striatal blood flow (CBF) during clozapine treatment is consistent with the mechanistic association between neuroglutamatergic activity and local blood flow supporting metabolism, and suggests that decreased striatal glutamate during clozapine treatment is consistent with a neural coupling mechanism.

[0038] The basic principles, main features, and advantages of this invention have been described above. Those skilled in the art should understand that this invention is not limited to the above embodiments, and the embodiments and descriptions in the specification are only for illustrating the principles of the invention. Various changes and modifications can be made based on this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A model for screening drugs for schizophrenia, the drug screening model comprising the steps of detecting (or collecting) changes in brain glutamate and / or its metabolites levels before and after drug administration, as well as changes in cerebral blood flow.

2. The model for screening drugs for schizophrenia according to claim 1, characterized in that... The model uses proton magnetic resonance spectroscopy (PRS) before and after drug administration. 1 H-MRS technology was used to detect (or collect) changes in glutamate and / or its metabolites in the brains of experimental animals, and combined with arterial spin labeling imaging (ASL) technology to assess changes in cerebral blood flow in the anterior cingulate cortex (ACC) and striatum, thereby evaluating the effect of drug intervention.

3. The model for screening drugs for schizophrenia according to claim 2, characterized in that... The experimental animals are selected from mammals, preferably including humans or mice.

4. The model for screening drugs for schizophrenia according to any one of claims 1 or 2, characterized in that... The schizophrenia mentioned is selected from treatment-resistant schizophrenia.

5. The model for screening drugs for schizophrenia according to any one of claims 1 or 2, characterized in that... The glutamate metabolite mentioned is selected from glutamine.

6. The model for screening drugs for schizophrenia according to any one of claims 1 or 2, characterized in that... The model includes the step of administering a positive control compound to experimental animals.

7. The model for screening drugs for schizophrenia according to claim 6, characterized in that... The positive control compound was selected from clozapine.

8. The model for screening drugs for schizophrenia according to claim 1, characterized in that... The model includes the steps of detecting (or collecting) data on changes in striatal glutamate and / or its metabolites and changes in striatal blood flow during the treatment period after administering the drug to experimental animals.

9. The model for screening drugs for schizophrenia according to claim 1, characterized in that... The model includes the steps of statistically analyzing the changes in striatal glutamate and striatal blood flow in experimental animals after administering the drug to be evaluated and the positive control compound, wherein the statistical analysis method is a multilevel linear regression model.

10. The application of the schizophrenia drug screening model according to any one of claims 1-9 in evaluating the efficacy of candidate compounds in treating schizophrenia.

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