Use of a PXR nuclear receptor and agonists thereof for the preparation of a medicament for the treatment of allergic asthma

Abstract

This invention belongs to the field of biomedical technology, specifically relating to the application of a PXR nuclear receptor and its agonist in the preparation of a drug for treating allergic asthma. The PXR nuclear receptor is used as a target for screening candidate drugs for treating allergic asthma. The PXR nuclear receptor agonist is selected from one or more of pregnenolone-16α-carbamate, dexamethasone, or rifampin. This invention also provides a pharmaceutical composition for treating allergic asthma, comprising a PXR nuclear receptor agonist and a pharmaceutically acceptable carrier or excipient. This invention is the first to clearly define the therapeutic association between the PXR nuclear receptor and allergic asthma, making PXR a clearly cultivable target for anti-asthma drug screening. Based on this target, a high-throughput screening model can be established to discover novel PXR agonists, thereby providing a tool for the development of next-generation anti-asthma drugs.

Description

Technical Field

[0001] This invention relates to the application of a PXR nuclear receptor and its agonist in the preparation of a drug for treating allergic asthma, belonging to the field of biomedical technology. Background Technology

[0002] Allergic asthma is a prevalent chronic inflammatory airway disease worldwide, with its incidence rate showing a continuous upward trend, making it one of the major public health challenges urgently needing to be addressed. Recent data shows that there are currently over 250 million asthma patients globally, with the incidence rate among children and young adults continuing to rise. Its high prevalence and high recurrence rate not only severely impact patients' quality of life but also increase the consumption of social medical resources. Surveys show that among asthma patients aged 20 and above in my country, over 80% have allergic asthma, making it a key disease for prevention and control in the field of respiratory diseases in my country.

[0003] Currently, the clinical treatment of allergic asthma primarily focuses on symptomatic relief, with commonly used medications including inhaled corticosteroids and long-acting β2-receptor agonists. While these medications can reduce airway inflammation to some extent, improve clinical symptoms such as wheezing and chest tightness, and slow disease progression to some degree, existing treatments lack effective reversal measures for the pathological changes related to airway remodeling that have already occurred during the course of allergic asthma, such as airway smooth muscle thickening and submucosal collagen deposition. This limitation leads to frequent relapses in some patients, making long-term stable clinical control difficult. Therefore, exploring novel regulatory targets that can intervene in the core pathological mechanisms of the disease is of great significance for developing more effective treatment strategies.

[0004] The pregnane X receptor (PXR) is a member of the nuclear receptor superfamily and a key molecule linking metabolic regulation and inflammatory responses. Previous studies have shown that PXR activation can reduce inflammation and collagen deposition in chronic kidney disease. However, in the pathological context of allergic asthma, the biological function of PXR and its impact on airway inflammation and airway remodeling processes remain unclear.

[0005] Currently, the role of PXR in the pathogenesis of allergic asthma is not clearly defined in existing technologies, and there are no studies on the role of PXR agonists in relieving allergic asthma. Summary of the Invention

[0006] This invention addresses the aforementioned shortcomings of existing technologies by providing an application of the PXR nuclear receptor and its agonist in the preparation of drugs for treating allergic asthma. This invention is the first to use the nuclear receptor PXR as a therapeutic target for allergic asthma, and experimentally demonstrates that PXR agonists can significantly alleviate airway inflammation and airway remodeling in allergic asthma by inhibiting arginase 1 expression, providing a new direction and experimental evidence for the treatment of allergic asthma.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: In a first aspect, the present invention provides the application of PXR nuclear receptor in the preparation of drugs for treating allergic asthma, using PXR nuclear receptor as a target for screening candidate drugs for treating allergic asthma.

[0008] Compared with the prior art, the beneficial effects of the present invention are: the present invention clarifies for the first time the therapeutic association between PXR nuclear receptor and allergic asthma, making PXR a clear druggable target for screening anti-asthma drugs. Based on this target, a high-throughput screening model can be established to discover novel PXR agonists, thereby providing tools for the development of next-generation anti-asthma drugs.

[0009] Furthermore, the screening includes detecting whether candidate substances can activate PXR nuclear receptor activity.

[0010] In a second aspect, the present invention provides the use of a PXR nuclear receptor agonist in the preparation of a medicament for treating allergic asthma, wherein the PXR nuclear receptor agonist is selected from one or more of pregnenolone-16α-carbamate (PCN), dexamethasone, or rifampin.

[0011] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention is the first to discover that PXR agonists can alleviate airway inflammation and airway remodeling by inhibiting arginase 1 expression. Dexamethasone, rifampin, and other PXR agonists are already marketed drugs. This invention achieves "drug repurposing," using these known drugs for the treatment of new indications of allergic asthma. This can significantly reduce the cost and risk of new drug development, shorten the clinical translation cycle, and has extremely high commercial value. In the future, it is expected to be used in combination with existing asthma drugs (such as inhaled corticosteroids and β2 receptor agonists) to achieve synergistic effects through different pathways.

[0012] Furthermore, the PXR nuclear receptor agonist alleviates airway inflammation and airway remodeling in allergic asthma by inhibiting the expression of arginase 1 (Arg1).

[0013] Furthermore, the drug is used to reduce the serum total IgE level, specific IgE level and / or specific IgG1 level in patients with allergic asthma.

[0014] Furthermore, the drug is used to reduce inflammatory cell infiltration, goblet cell proliferation, and / or collagen deposition in the lung tissue of patients with allergic asthma.

[0015] Thirdly, the present invention provides a pharmaceutical composition for treating allergic asthma, comprising a PXR nuclear receptor agonist and a pharmaceutically acceptable carrier or excipient.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the pharmaceutical composition can directly act on the PXR target, exert its anti-inflammatory and anti-remodeling effects by activating PXR, and can be formulated into appropriate drug dosage forms according to clinical needs for the treatment of allergic asthma of different severity, providing new treatment options for clinical practice.

[0017] Furthermore, the PXR nuclear receptor agonist is rifampin or dexamethasone. Attached Figure Description

[0018] Figure 1 This is a comparison of airway resistance (Rn) in three groups of mice under different concentrations of methacholine stimulation in Example 1. Figure 2 The serum total IgE levels of the three groups of mice in Example 1; Figure 3 The serum specific IgE (sIgE) levels of the three groups of mice in Example 1; Figure 4 The serum specific IgG1 (sIgG1) levels of the three groups of mice in Example 1; Figure 5 Images of hematoxylin-eosin (H&E), alcian blue-periodic acid-Schiff (AB-PAS), and Masson staining of lung tissue from three groups of mice in Example 1. Figure 6 The inflammation scores of H&E staining of lung tissue from three groups of mice in Example 1; Figure 7 The goblet cell proliferation scores of the lung tissues of the three groups of mice in Example 1; Figure 8 The expression levels of inflammatory factors in the lung tissues of the three groups of mice in Example 1; Figure 9 A graph showing the expression changes of molecules such as Arg1 and IL4i1 in metabolic pathways using KEGG proteomics analysis; Figure 10 This is a representative band image of Arg1 protein levels in the lung tissues of three groups of mice in Example 1, obtained by Western blot analysis. Figure 11 for Figure 10Semi-quantitative statistical plots of Western blot results; Figure 12 These are representative images of Arg1 protein levels in lung tissue from three groups of mice as detected by immunofluorescence in Example 1. Figure 13 for Figure 12 Semi-quantitative statistical graph of immunofluorescence results; Figure 14 This is a comparative graph showing the airway resistance (Rn) of four groups of mice under different concentrations of methacholine stimulation. Figure 15 The serum specific IgE (sIgE) levels of the four groups of mice were used as a comparison. Figure 16 The total serum IgE levels of the four groups of mice were used as a control. Figure 17 Images of H&E staining, AB-PAS staining, and Masson staining of lung tissue from four groups of mice in comparative examples; Figure 18 The comparison is based on H&E staining of lung tissue from four groups of mice to determine inflammation scores. Figure 19 The comparison group of four groups of mice had goblet cell proliferation scores in their lung tissues. Figure 20 The expression levels of the inflammatory factor IL5 in the lung tissues of four groups of mice were compared. Figure 21 The expression levels of the inflammatory factor CCL2 in the lung tissues of four groups of mice were compared. Figure 22 Representative images of Arg1 protein levels detected by immunofluorescence in lung tissues of four groups of mice in the comparative example; Figure 23 for Figure 22 Semi-quantitative statistical graph of immunofluorescence results. Detailed Implementation

[0019] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0020] Example 1 1. Experimental Materials Experimental animals: Female wild-type BALB / c mice, 6 weeks old, purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd., were acclimatized for 1 week before being grouped and modeled.

[0021] Main reagents: Artemisia annua pollen was purchased from Beijing Xinhua Lianhe Pharmaceutical Co., Ltd. Pollen protein extract was prepared according to the total pollen protein extraction process, and the protein concentration of the pollen extract was detected using the BCA protein quantification kit.

[0022] Aluminum hydroxide adjuvant was purchased from Beijing Bolede International Trade Co., Ltd.

[0023] Pregnenolone-16α-carbamate (PCN) was purchased from APExBIO Technology LLC (Houston, TX, USA).

[0024] Acetylcholine was purchased from TCI (Shanghai) Chemical Industry Development Co., Ltd. (TCI, item number M0073).

[0025] 2. Animal grouping and treatment Mice were randomly divided into three groups of 6–8 mice each: control group (CON), asthma group (Asthma), and asthma + PCN treatment group (Asthma + PCN).

[0026] Modeling (divided into sensitization and stimulation phases): Sensitization: Allergic asthma models were sensitized on days 1, 8, and 15. Mice in the asthma group and the asthma + PCN group were intraperitoneally injected with a mixture of 110 μL of Artemisia annua pollen solution (PBS solution containing 25 μg of Artemisia annua pollen) and 100 μg of aluminum hydroxide adjuvant; mice in the control group were intraperitoneally injected with 110 μL of PBS solution containing 100 μg of aluminum hydroxide adjuvant.

[0027] First challenge: Nebulized challenge was performed on days 22-24. Mice in the asthma group and the asthma + PCN group were nebulized with 1% Artemisia annua pollen solution (1g of Artemisia annua pollen protein was dissolved in 100 mL of PBS solution), while the control group was nebulized with an equal volume of PBS. This was done for 3 consecutive days, 30 minutes each day.

[0028] PCN treatment phase: From day 25 to 40, mice in the asthma + PCN group were administered 50 mg / kg PCN (dissolved in corn oil, concentration 0.005 mg / μL) by gavage once every other day for a total of 6 times; mice in the control group and asthma group were administered an equal volume of corn oil by gavage.

[0029] Second stimulation: From day 43 to 49, a second nebulization stimulation is performed under the same conditions as the first stimulation. Lung function tests are conducted 24 hours after the final nebulization session.

[0030] 3. Airway hyperresponsiveness detection Respiratory mechanics in mice was assessed using a FlexiVent small animal ventilator (SCIREQ, Canada). Airway resistance (Rn) primarily reflects changes in horizontal airway resistance. After endotracheal intubation, mice underwent continuous aerosol challenge with PBS, followed by sequential aerosol challenge with gradient concentrations of methacholine (6 mg / mL, 12 mg / mL, 24 mg / mL, 48 mg / mL). Rn values ​​were recorded immediately after each aerosol challenge.

[0031] Experimental results: like Figure 1 As shown, in the Artemisia annua pollen-induced asthma group mice, airway hyperresponsiveness (Rn) was significantly increased after methacholine challenge, especially at concentrations of 24 mg / mL and 48 mg / mL, showing a highly significant difference compared to the control group (P < 0.05). After PCN treatment, airway hyperresponsiveness in the asthma mice in the asthma + PCN group was significantly alleviated under methacholine challenge at 48 mg / mL.

[0032] The results showed that PXR agonists could effectively reduce airway hyperresponsiveness and improve lung function in mice with allergic asthma.

[0033] 4. Serum immunoglobulin level detection Serum immunoglobulin (total IgE, sIgE, sIgG1) levels were detected using ELISA. The total IgE kit was purchased from Elabscience Biotechnology Co., Ltd., and the procedure was followed according to the manufacturer's instructions. The detection steps for sIgE and sIgG1 levels were as follows: Artemisia annua pollen protein was diluted to a final concentration of 10 μg / mL in coating buffer (ab210899, pH 9.6), and 100 μL was added to each well of a 96-well plate. The plate was incubated overnight at 4°C. The next day, the plate was washed five times with PBST, and each well was blocked with 200 μL of blocking buffer (1% BSA-PBST) at room temperature for 2 h. Mouse serum samples were diluted 1:200 in blocking buffer for sIgG1 detection and 1:10 for sIgE detection. 100 μL of the diluted serum was added to each well, and the plate was incubated overnight at 4°C. The following day, after washing five times with PBST, add 100 μL of secondary antibody diluted 1:1000 in blocking buffer to each well and incubate at room temperature for 2 h. Then add TMB substrate and incubate at 37°C in the dark for 20 min. Terminate the reaction with 2 mol / L sulfuric acid and read the absorbance value (OD450) at 450 nm using a microplate reader.

[0034] Experimental results: like Figures 2-4As shown, compared with the control group, the serum total IgE, sIgE, and sIgG1 levels in the asthma group mice were significantly increased (P < 0.001). After PCN treatment, the serum levels of the above immunoglobulins in the asthma + PCN group mice were significantly decreased (P < 0.05).

[0035] The results showed that PCN treatment weakened the Th2 (type 2 helper T cell) response in mice and slowed the maturation of Artemisia annua-specific B cells.

[0036] 5. Lung tissue pathological examination Wright-Gymsa staining, hematoxylin-eosin (H&E) staining, and Alcian blue-periodic acid-Schiff (AB-PAS) staining kits were purchased from Beijing Solarbio Technology Co., Ltd., and all staining procedures were performed according to the manufacturer's instructions. Wright-Gymsa staining was used to observe inflammatory cells in bronchoalveolar lavage fluid (BALF); hematoxylin-eosin (H&E) staining of lung tissue sections was used to assess peribronchial inflammatory cell infiltration; and Alcian blue-periodic acid-Schiff (AB-PAS) staining was used to assess goblet cell proliferation and airway mucus secretion.

[0037] A 5.5-point quantitative scoring system was used to grade the severity of inflammatory cell infiltration and goblet cell proliferation in a blinded manner. Inflammation: 0 = no cell infiltration, 1 = few cell infiltrations, 2 = 1-4 cell layers of infiltration, 3 = 2-4 cell layers of infiltration, 4 = 4-6 cell layers of infiltration, 5 => 6 cell layers of infiltration; 0 = no goblet cells, 1 = <15% of airway epithelium has goblet cells, 2 = 15%-30% of airway epithelium has goblet cells, 3 = 30%-45% of airway epithelium has goblet cells, 4 = 45%-60% of airway epithelium has goblet cells, 5 => 60% of airway epithelium has goblet cells. Observation and scoring were performed under a light microscope.

[0038] Experimental results: H&E staining results (see) Figure 5 Compared with the control group, the asthma group mice showed extensive inflammatory cell infiltration around the bronchi, forming multi-layered cell rings, accompanied by bronchial thickening and edema, a small number of alveolar atrophy and collapse, and peripheral alveolar fusion and expansion. In the asthma + PCN group mice, all of the above pathological changes were significantly improved after PCN treatment. Inflammation score results showed (see...) Figure 6 The inflammation score in the asthma + PCN group was significantly lower than that in the asthma group.

[0039] AB-PAS staining results (see) Figure 5Compared to the control group, the airway walls of mice in the asthma group were extensively stained blue-purple, indicating abundant goblet cell proliferation and mucus secretion. PCN treatment effectively inhibited goblet cell proliferation induced by asthma in mice in the asthma + PCN group. Goblet cell proliferation scores showed (see...). Figure 7 The scores of the asthma + PCN group were significantly lower than those of the asthma group.

[0040] Masson staining results (see...) Figure 5 ): In the asthma group, there was a large amount of collagen deposition in the subepithelial lung tissue of mice, while in the asthma + PCN group, PCN treatment significantly inhibited peribronchial collagen deposition and alleviated airway remodeling caused by asthma.

[0041] The results showed that PXR agonists could significantly reduce lung tissue inflammation and pathological changes, inhibit goblet cell proliferation, and reduce airway remodeling in mice with allergic asthma.

[0042] 6. Detection of inflammatory factors in lung tissue The Luminex Multi-Inflammatory Factor Mouse Detection Kit was purchased from R&D Systems (Minnesota, USA). The expression levels of IL-1β, TNF-α, IL-5, IL-3, and CCL2 in lung tissue homogenates were detected using the Luminex 200 high-throughput multiplex assay platform. All procedures were performed according to the manufacturer's protocol.

[0043] Experimental results: like Figure 8 As shown, the expression levels of type 2 inflammatory cytokines IL-5 and IL-13, inflammatory mediators CCL2 and TNF-α, and G-CSF and GM-CSF in the lung tissue of asthma group mice were significantly increased compared with those in control group. In asthma + PCN group mice, the expression levels of the above inflammatory cytokines were significantly decreased after PCN treatment.

[0044] The results showed that PXR agonists significantly inhibited the inflammatory response in lung tissue of allergic asthma and reduced the expression of various inflammatory factors. This suggests that PCN treatment may play a role by inhibiting the Th2 response in the asthma process.

[0045] 7. Verification of the mechanism by which PXR activates and inhibits Arg1 expression Arg1 is a key rate-limiting enzyme in arginine metabolism. It primarily regulates the metabolic flow of arginine by breaking it down into ornithine and urea, thereby influencing the production of downstream reactive substances such as nitric oxide (NO), polyamines, and proline. Early foreign researchers believed that Arg1 was mainly secreted by M2 macrophages, inhibiting iNOS (inducible nitric oxide synthase)-mediated NO production by consuming arginine, thus exacerbating airway smooth muscle contraction and inflammatory responses. However, some researchers have found that Arg1 expression is significantly increased in the lung epithelial cells of OVA (ovalbumin)-induced allergic asthma mice; knocking out Arg1 in hematopoietic cells improves lung respiratory function in asthmatic mice, but has no significant effect on large airway function or inflammation, suggesting that the role of Arg1 varies across different cell types.

[0046] Further studies have confirmed that only Arg1 expression was significantly elevated in human asthma and mouse models of chronic asthma, while Arg2 and some NOS subtypes were also altered in acute models, suggesting that Arg1 may have a differentiated regulatory pattern in acute and chronic asthma. Research indicates that Arg1 derived from myeloid cells can provide collagen synthesis substrates to lung fibroblasts by producing ornithine, thus constituting a metabolic dialogue between myeloid cells and fibroblasts and participating in the airway remodeling process.

[0047] In summary, Arg1, as a key enzyme in arginine metabolism, plays an important role in airway inflammation and remodeling in asthma. However, its specific functions and upstream regulatory mechanisms in different cell types and disease stages have not been fully elucidated and require further in-depth exploration.

[0048] To clarify the potential role of nuclear receptor PXR in arginine metabolism imbalance in allergic asthma, this embodiment uses quantitative proteomics technology to analyze the differences in protein expression between lung tissue of pollen-induced allergic asthma mice and normal control group.

[0049] (1) Quantitative proteomics analysis Lung tissues from successfully established asthma model mice (n=6 per group) were collected for label-free quantitative proteomics analysis. The simplified procedure is as follows: Total protein was extracted from the tissues, and protein concentration was determined using the BCA method; 30 μg of protein sample was subjected to reduction, alkylation, and enzymatic digestion. 500 ng of the digested protein sample was then separated using a Vanquish Neo nano-liter ultra-high performance liquid chromatography system, followed by data acquisition on an Astral mass spectrometer equipped with a nano-spray ion source. The raw mass spectrometry data were imported into DIA-NN software (version 1.8.1) for database searching, and qualitative analysis was performed after the search was completed.

[0050] Experimental results: Figure 9The results of KEGG proteomics analysis showed that the arginine metabolism pathway was significantly disrupted in the lung tissue of asthma-affected mice, with the expression level of Arg1, a key rate-limiting enzyme in arginine metabolism, being upregulated by nearly 20-fold compared to the control group. In the asthma + PCN group, the abnormally high expression of Arg1 was significantly inhibited after PCN treatment.

[0051] In addition, the expression of metabolism-related molecules such as IL4i1 was significantly increased in the asthma group, and the expression level of IL4i1 was reduced in mice in the asthma + PCN group after PCN treatment, suggesting that PXR activation may play a protective role by regulating multiple metabolic pathways.

[0052] (2) Western blot verification Protein samples (40 μg) quantified by the BCA method were separated by SDS-PAGE gel electrophoresis. The separated proteins were transferred to a PVDF membrane using a wet transfer method. The membrane was blocked with 5% skim milk for 30 min, followed by incubation with primary antibodies against the target protein and internal control protein, respectively; the corresponding secondary antibodies were added the following day. Protein bands were visualized using chemiluminescence immunoassay, and the grayscale ratio of the target protein to the internal control protein was analyzed using ImageJ software to calculate the relative expression level of the target protein.

[0053] Experimental results: See Figures 10-11 Western blot results showed that the expression level of Arg1 protein in the lung tissue of asthma group mice was significantly higher than that in the control group, while the expression level of Arg1 in asthma + PCN group mice was significantly lower than that in the asthma group after PCN treatment. This suggests that PXR activation may alleviate asthma damage by inhibiting Arg1 expression.

[0054] (3) Validation by immunofluorescence staining After dewaxing to water, antigen retrieval, and membrane blocking, sections were incubated with primary antibody overnight at 4°C. They were then washed three times with PBS for 5 minutes each time. Subsequently, the corresponding fluorescently labeled secondary antibody was added, and the sections were incubated at room temperature for 1 hour. They were then washed three more times with PBS for 5 minutes each time, followed by DAPI staining for 8 minutes. Images were acquired using a laser confocal scanning microscope, and the fluorescence intensity of the target protein was quantified using ImageJ software to assess protein expression levels.

[0055] Experimental results: See Figures 12-13 Immunofluorescence staining results showed that the fluorescence intensity of Arg1 in the lung tissue of asthma group mice was significantly enhanced compared with that of control group, while the fluorescence intensity of Arg1 in asthma + PCN group mice was significantly weakened compared with asthma group after PCN treatment.

[0056] Allergic asthma is a type of chronic inflammatory lung disease with a complex pathogenesis influenced by both genetics and environment. After the first inhalation of an allergen, the body's immune system is activated, causing B lymphocytes to produce specific IgE (sIgE). SIgE binds to IgE receptors on the surface of mast cells and basophils. Upon re-exposure to the allergen, the allergen binds to sIgE, causing these cells to synthesize and release inflammatory mediators, leading to airway smooth muscle contraction, increased mucus secretion, and inflammatory cell infiltration, resulting in the clinical symptoms of asthma. Therefore, the main characteristics of allergic asthma include elevated serum IgE levels, inflammatory cell infiltration such as eosinophils in the lungs, excessive mucus secretion, and enhanced non-specific respiratory reactions.

[0057] Based on the above experimental results, this invention is the first to demonstrate that the PXR nuclear receptor is an effective therapeutic target for allergic asthma. PXR agonists can reduce airway hyperresponsiveness, alleviate airway inflammation and airway remodeling by inhibiting the expression of arginase 1 (Arg1), thereby achieving the goal of treating allergic asthma. Specifically, the experimental results showed that, compared with the control group, mice in the Artemisia annua pollen-induced asthma group exhibited a significant increase in airway hyperresponsiveness (Rn) after methacholine challenge, especially at a concentration of 48 mg / mL, where the effect was most significant (P < 0.05). Compared with the control group, the serum total IgE and sIgE levels in the asthma group mice were significantly increased. H&E staining of lung tissue revealed that, compared with the control group, the asthma group mice had extensive inflammatory cell infiltration around the bronchi, forming multi-layered cell rings, accompanied by airway thickening and edema, with a small number of alveoli collapsing and merging and expanding. AB-PAS staining of lung tissue showed that, compared with the control group mice, the airway walls of the asthma group mice were widely stained blue-purple, and diffuse blue-purple was also visible within the airways, indicating the production of large amounts of mucus. Mucus production was reduced in the asthma + PCN treatment group. Inflammation infiltration scores also showed increased inflammation in the lung tissue of the asthma group mice. The Luminex 200 high-throughput multifactor detection platform detected the levels of inflammatory factors in the lung tissue of each group of mice. The results showed increased expression levels of type 2 inflammatory factors IL5 and IL3, and inflammatory mediators CCL2 and TNF-alpha in the lung tissue of the asthma group. However, in the asthma + PCN group mice treated with the PXR agonist PCN, the aforementioned asthma-induced damage was alleviated.

[0058] Comparative Example Experimental animals: PXR gene knockout (PXR) was selected. - / - Mice (strain background consistent with wild-type BALB / c mice in Example 1), and simultaneously wild-type mice with the same genetic background (PXR) were also included. + / + Mice were used as parallel controls.

[0059] Animal grouping and treatment: PXR + / +Mice and PXR - / - Mice were randomly divided into a control group (PBS treatment) and an asthma model group (Artemisia annua pollen-induced), for a total of 4 groups, with 6–8 mice in each group. The specific groupings are as follows: Wild-type control group (PXR) + / + +PBS); Wild-type asthma group (PXR) + / + +Pollen); PXR knockout control group (PXR - / - +PBS); PXR knockout asthma group (PXR - / - + pollen).

[0060] The following tests were performed sequentially 24 hours after the last atomization activation: Airway hyperresponsiveness detection (FlexiVent small animal ventilator, Rn value detected); Serum immunoglobulin level detection (ELISA method for detecting total IgE, sIgE, and sIgG1); Lung tissue pathological examination (H&E staining to assess inflammatory infiltration, AB-PAS staining to assess goblet cell proliferation, Masson staining to assess collagen deposition); Detection of Arg1 protein expression in lung tissue (Western blot and immunofluorescence staining).

[0061] Experimental results: like Figures 14-23 As shown, compared with the wild-type asthma group (PXR) + / + Compared to the PXR knockout asthma group (+pollen), the PXR knockout asthma group (PXR) - / - Mice stimulated with pollen showed significantly increased airway hyperresponsiveness (significantly elevated Rn values) after methacholine provocation, with markedly aggravated serum total IgE, sIgE levels, lung tissue inflammatory infiltration scores, and collagen deposition. This result is the first genetic confirmation that the absence of endogenous PXR significantly worsens the pathological process of allergic asthma, demonstrating the indispensable protective role of PXR in maintaining airway immune homeostasis.

[0062] The above comparative results show that PXR gene knockout exacerbates the severity of allergic asthma, which strongly proves that the PXR nuclear receptor is indeed a key protective regulator in the pathogenesis of allergic asthma. Targeting and activating PXR can alleviate the pathological damage of asthma by inhibiting Arg1 expression. The PXR nuclear receptor and its agonist described in this invention are used to prepare drugs for treating allergic asthma, which have clear therapeutic effects and reliable genetic evidence.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. The use of a PXR nuclear receptor in the preparation of a drug for treating allergic asthma, characterized in that, PXR nuclear receptors were used as targets to screen candidate drugs for the treatment of allergic asthma.

2. The use of the PXR nuclear receptor according to claim 1 in the preparation of a medicament for treating allergic asthma, characterized in that, The screening process includes detecting whether candidate substances can activate PXR nuclear receptor activity.

3. The use of a PXR nuclear receptor agonist in the preparation of a medicament for treating allergic asthma, characterized in that, The PXR nuclear receptor agonist is selected from one or more of pregnenolone-16α-carbamate, dexamethasone, or rifampin.

4. The use of the PXR nuclear receptor agonist according to claim 3 in the preparation of a medicament for treating allergic asthma, characterized in that, The PXR nuclear receptor agonist alleviates airway inflammation and airway remodeling in allergic asthma by inhibiting the expression of arginase 1.

5. The use of the PXR nuclear receptor agonist according to claim 3 or 4 in the preparation of a medicament for treating allergic asthma, characterized in that, The drug is used to reduce the serum levels of total IgE, specific IgE, and / or specific IgG1 in patients with allergic asthma.

6. The use of the PXR nuclear receptor agonist according to claim 3 or 4 in the preparation of a medicament for treating allergic asthma, characterized in that, The drug is used to reduce inflammatory cell infiltration, goblet cell proliferation and / or collagen deposition in the lung tissue of patients with allergic asthma.

7. A pharmaceutical composition for treating allergic asthma, characterized in that, It contains a PXR nuclear receptor agonist and a pharmaceutically acceptable carrier or excipient.

8. The pharmaceutical composition for treating allergic asthma according to claim 7, characterized in that, The PXR nuclear receptor agonist is rifampin or dexamethasone.

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