Construction method and application of smog-induced IgA nephropathy mouse model

Abstract

The invention relates to the technical field of medicines, and provides a construction method and application of a smog-induced IgA nephropathy mouse model. An IgAN model based on PM2.5 continuous exposure induction is constructed, the influence of long-term environmental particulate matter stimulation on respiratory mucosal immunity can be simulated, and a key chain of mucosal immune activate-Gd-IgA1 overexpression-immune complex formation in human IgAN is effectively simulated, so that the correlation between kidney phenotypic change and mucosal immune activation is observed, and the accuracy and the sensitivity of the kidney phenotypic change are improved. And evidence is provided for direct association of the mucous membrane system and the renal injury. The model better conforms to the human pathogenesis background, the phenotype is stable, the operation is controllable, and conversion or popularization is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of animal models, and in particular relates to a method for constructing a smoke-induced IgA nephropathy mouse model and its application. Background Art

[0002] IgA nephropathy (IgAN) is the most common primary glomerular disease in my country. Its primary characteristic is the deposition of IgA1-dominated immune complexes in the glomerular mesangium, triggering mesangial cell proliferation and matrix accumulation. IgAN is generally considered an autoimmune disease whose pathogenesis is primarily based on the "quadruple hit theory": abnormal increase in Gd-IgA1, production of autoantibodies targeting Gd-IgA1, formation of immune complexes, and localized deposition of complexes in the glomeruli, triggering an inflammatory response.

[0003] In order to explore the pathogenesis of IgAN and use it for drug evaluation, the construction of mouse models that conform to the characteristics of human disease has become the key to research. Currently, a variety of IgAN animal models have been proposed:

[0004] (1) Spontaneous IgA deposition model in ddY mice: This model can produce IgA deposition in renal tissue under natural conditions, and some animals develop proteinuria, but the phenotype is unstable, and there are significant individual differences in the incidence and progression degree. The behavioral tolerance is large, which is not conducive to reproducible experiments;

[0005] (2) Lipopolysaccharide (LPS) + carbon tetrachloride (CCl4) + bovine serum albumin (BSA) induced model: Glomerular IgA deposition is induced by a combination of multiple immune and liver damage stimulations. Although it simulates the IgAN immune activation background to a certain extent, its induction mechanism is complex, involving multiple systemic injuries, the model construction cycle is long, and the animal stress response is strong;

[0006] (3) Tail vein injection of IgA-induced model: After multiple injections of abnormally glycosylated IgA into the tail vein within 2 weeks, mice showed IgA deposition in the renal tissue without proteinuria or hematuria.

[0007] (4) Lactobacillus casei cell wall extract (LCWE)-induced model: LCWE was used to stimulate complement factor H heterozygous null mice (FHW / R) to establish an experimental model. After 30 weeks of modeling, the mice developed proteinuria, hematuria, IgA and complement C3 deposition.

[0008] (5) microRNA-23b knockout mouse model: Single gene knockout of miR-23b using Cas-9 technology can lead to increased renal resistance coefficient, increased blood pressure, increased urine protein, increased IgA in serum and glomeruli, and the deposition of immune complexes in the glomerular mesangium.

[0009] Although the above models can reproduce some pathological features of IgAN to some extent, most of them fail to effectively simulate the key chain of "mucosal immune activation-Gd-IgA1 overexpression-immune complex formation" in human IgAN, and lack direct evidence of the direct association between the mucosal system and kidney injury.

[0010] In recent years, studies have found that mucosal immune imbalance plays an important role in the pathogenesis of IgAN, such as the observation of the correlation between NALT and abnormal IgA expression in ddY mice, and the finding of intestinal mucosal immune disorder in LCWE-induced models. SUMMARY

[0011] The present application aims to solve the above problems, and constructs an IgAN model induced by continuous exposure to PM2.5 to simulate the effect of long-term environmental particulate matter stimulation on respiratory mucosal immunity, so as to observe the correlation between kidney phenotype changes and mucosal immune activation, and strive to establish a new type of IgAN mouse model that is more in line with the human pathogenesis background, stable in phenotype, and controllable in operation.

[0012] In order to achieve the above purpose, the specific technical solutions of the present application are as follows:

[0013] In a first aspect of the present application, a method for constructing a smoke-induced IgA nephropathy mouse model is provided. The model group experimental animals are fed in a clean environment for a certain period of time, and then exposed to a high concentration PM2.5 environment in the morning and afternoon for two predetermined time periods, 7 days a week, for 6 months. The control group experimental animals are fed in a clean air environment for the same period. After 6 months, the model group is removed from the polluted environment and continues to be fed in a clean environment with the control group.

[0014] Preferably, the experimental animals are selected from C57BL / 6 strain 6-week-old mice, which are fed in a specific pathogen-free (SPF) environment, given standard diet, and controlled at an environmental temperature of 22°C, humidity of 50-60%, and stable 12-hour light-dark cycle.

[0015] Preferably, the model group mice are exposed to a high concentration PM2.5 environment for two hours in the morning and afternoon; further, they are exposed to a high concentration PM2.5 environment from 8:00 to 10:00 in the morning and from 14:00 to 16:00 in the afternoon.

[0016] Preferably, the high concentration PM2.5 environment refers to a concentration that is 100-400 times higher than the 24-hour average PM2.5 concentration limit.

[0017] The present application uses the method of lighting cigarettes in two cages of 42*33*13cm feeding cages to create a high concentration PM2.5 environment. According to the Chinese air quality standard, the 24-hour average PM2.5 concentration limit is 75 μg / m3 , more than 250 μg / m 3 It is considered severe pollution. The smoke concentration produced by a few cigarettes in such a small environment is extreme pollution.

[0018] Preferably, after 6 months, the model group is removed from the polluted environment and is kept together with the control group in a clean environment for another 3 months.

[0019] During the experiment, some mice were killed by cervical dislocation at 1, 2, 3, 6, and 9 months after exposure, and blood, urine, and kidney tissue samples were collected for relevant tests. The results showed that the weight of the mice in the modeling group was always much lower than that of the mice in the control group, and it was difficult to recover quickly even after leaving the PM2.5 environment. Three months after leaving the PM2.5 environment, the weight of the mice in the PM2.5 exposure group was still similar to that at 6 months after modeling; as the modeling time progressed, the inflammation, IgA levels, and the resulting glomerular mesangial deposition, mesangial cell proliferation, and increased matrix in the modeling group mice became increasingly different from those in the control group, and even after leaving the PM2.5 environment, the differences remained significant. This indicates that the IgA nephropathy animal model was successfully constructed.

[0020] Therefore, in a second aspect, the present invention provides a smoke-induced IgA nephropathy mouse model IgAN, which is constructed using the method described above.

[0021] In a third aspect, the present invention provides applications of the IgAN animal model, such as applications in IgA nephropathy drug screening.

[0022] Functions and effects of the invention

[0023] This study constructed an IgAN model induced by continuous PM2.5 exposure. This model simulates the effects of long-term environmental particulate matter stimulation on respiratory mucosal immunity, effectively simulating the key chain of human IgAN: mucosal immune activation, Gd-IgA1 overexpression, and immune complex formation. This model allows for the association between renal phenotypic changes and mucosal immune activation, providing evidence for a direct link between the mucosal system and renal injury. This model better aligns with the human pathogenesis, offers a stable phenotype, and is easily controllable, making it amenable to translational and widespread use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Shows a schematic diagram of the modeling process of the present invention;

[0025] Figure 2 Shows the hematuria of mice 6 months after PM2.5 modeling;

[0026] Figure 3 The results of immunohistochemical PAS staining of kidney tissues in the control group and model group are shown;

[0027] Figure 4 The results of IgA and C3 immunohistochemistry and electron microscopy in the kidneys of mice in the control and model groups are shown;

[0028] Figure 5 Shows the electron microscopic results of kidney tissue of mice exposed to PM2.5 environment for 3 months;

[0029] Figure 6 Double-labeled immunofluorescence staining of kidney tissue after 3 months of PM2.5 exposure is shown;

[0030] Figure 7 The changes in serum polymeric IgA and monomeric IgA levels over time in the model group mice are shown. DETAILED DESCRIPTION

[0031] The following examples and experimental examples further illustrate the present invention and should not be construed as limiting the present invention. The examples do not include detailed descriptions of conventional methods, which are well known to those skilled in the art and are described in numerous publications.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the present invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0033] 1. Animal Model Construction and Detection Methods

[0034] 1. Animal breeding and model establishment

[0035] The animals used were 6-week-old C57BL / 6 mice, a total of 30 6-week-old mice, divided into a PM2.5 exposure modeling group and a control group, with 15 mice in each group. No mice died unexpectedly in the laboratory, and all mice completed this study. All mice were housed in a specific pathogen-free (SPF) environment, given a standard diet, and controlled at an ambient temperature of 22°C and a humidity of 50–60%, maintaining a stable 12-hour light and dark cycle. All animal experiments have been reviewed and approved by the Institute's Animal Ethics Committee. The modeling process is as follows Figure 1 Figure 2: Model group mice were exposed to high PM2.5 concentrations twice daily (8:00–10:00 AM and 2:00–4:00 PM), 7 days a week, for 6 months. Control group mice were housed in a clean air environment during the same period. After 6 months, model group mice were removed from the polluted environment and continued to be housed in a clean environment alongside the control group.

[0036] 2. Time of mouse sacrifice and sample collection

[0037] At 1, 2, 3, 6, and 9 months after exposure, the mice were randomly selected and executed by cervical dislocation, and blood, urine, and kidney tissue samples were collected.

[0038] 3. Detection of mouse urinary albumin and albumin / creatinine ratio (UACR)

[0039] At 1, 2, 3, 6, and 9 months after PM2.5 exposure, the mice were randomly selected and executed by cervical dislocation, and blood, urine, and kidney tissue samples were collected.

[0040] 4. Detection of mouse hematuria

[0041] Fresh random urine samples were used for hematuria detection, and commercial hematuria test strips (SIEMENS, multi-index urine analysis test strips) were used for semi-quantitative analysis. The operation was carried out according to the product instruction, and the color change of the test strip was judged by two observers independently to avoid subjective bias.

[0042] 5. Detection of mouse serum creatinine (SCR)

[0043] Immediately after the mice were executed, blood was taken to separate serum, and QuantiChrom™ Creatinine Assay Kit (BioAssay Systems) was used to determine the serum creatinine concentration according to the instruction.

[0044] 6. Detection of mouse serum urea nitrogen (BUN)

[0045] The serum urea nitrogen concentration was detected by the detection kit (K024-H1) provided by ARBOR ASSAYS company. Sample processing and detection were carried out according to the instruction, and the absorbance was determined by end-point method, and the urea nitrogen concentration was calculated.

[0046] 7. Immunohistochemistry and immunofluorescence of kidney tissue

[0047] The paraffin-embedded kidney tissue sample was cut into 1.5 μm thick sections, and periodic acid-Schiff (PAS) staining was used for morphological observation. Kidney tissue pathological damage was evaluated by PAS staining, and glomerular, tubular interstitial and vascular lesions were observed.

[0048] For immunofluorescence staining, the frozen kidney tissue sections with a thickness of 2 μm were incubated at 37 °C for 1 h. IgA was detected using goat anti-mouse IgA antibody (Bethyl A90-134A Goat anti-Mouse Albumin Antibody), and C3 antibody (Abcam, ab200999, 1:100, 10 μg / mL). The nuclei were stained using DAPI (Abcam). Fluorescent images were captured using a fluorescence microscope (Leica, Germany). The staining intensity was scored according to the following scale: 0 (negative): no fluorescent signal, indicating that the target molecule was not detected; 1+ (weakly positive): weak fluorescent signal, which might be background or low expression; 2+ (moderately positive): clear but moderate intensity of fluorescent signal, suggesting the presence of the target molecule; 3+ (strongly positive): bright fluorescent signal, indicating high expression of the target molecule; 4+ (very strongly positive): very strong fluorescent signal, which is usually seen in highly enriched or aggregated cases.

[0049] 8. Electron microscopy of kidney tissue

[0050] 1) Sample collection and fixation: The sampling site was determined on fresh tissue, and mechanical damage such as pulling, bruising, and squeezing was minimized. The sample was taken within 1-3 min, and the sample size was 1 mm 3 . Before sampling, a culture dish containing electron microscopy fixative was prepared. The small tissue block was removed from the body and immediately placed in the culture dish. A surgical knife was used to cut the small tissue block into 1 mm 3 pieces in the fixative solution in the culture dish. The cut small tissue block was then transferred to an EP tube containing fresh electron microscopy fixative for further fixation. The sample was stored and transported at 4 °C. The sample was rinsed three times with 0.1M phosphate buffer PB (PH 7.4) for 10 min each time.

[0051] 2) Post-fixation: 1% osmium acid prepared with 0.1M phosphate buffer PB (PH 7.4) was used for room temperature fixation for 2 h. The sample was rinsed three times with 0.1M phosphate buffer PB (PH 7.4) for 15 min each time.

[0052] 3) Room temperature dehydration: The tissue was sequentially dehydrated in 30%-50%-70%-80%-95%-100%-100% alcohol for 10 min each time, and 100% acetone for 10 min twice.

[0053] 4) Permeation and embedding: acetone:812 embedding agent = 1:1, 37 °C for 2-4 h, acetone:812 embedding agent = 1:2, 37 °C for permeation overnight, and pure 812 embedding agent at 37 °C for 5-8 h. The pure 812 embedding agent was poured into the embedding plate, and the sample was inserted into the embedding plate and then baked in the oven at 37 °C overnight.

[0054] 5) Polymerization: Place the embedded plate in a 60°C oven for 48 hours, then remove the resin block for later use.

[0055] 6) Ultrathin sectioning: The resin block was sliced ​​into 70 nm thin sections using an ultrathin microtome (Leica UC7; Leica), and the sections were picked up using a 200-mesh copper mesh.

[0056] 7) Staining: Stain the copper mesh in a 2% uranyl acetate saturated alcohol solution in the dark for 10 minutes. Rinse three times with ultrapure water. Stain the mesh in a lead citrate solution in the dark for 10 minutes. Rinse three times with ultrapure water and blot dry with filter paper. Place the mesh sections in a mesh box and dry overnight at room temperature.

[0057] 8) Observation under a transmission electron microscope (HT7700, HITACHI).

[0058] 9. ELISA for detection of mouse IgA (mIgA): Collect mouse serum samples and detect the mIgA level by ELISA using the kit Bethyl Laboratories Catalog No. E99-103 according to the instructions.

[0059] 10. Mouse lymph node cell IgA secretion experiment

[0060] 1) Animal Handling and Lymph Node Extraction: Mice were sacrificed by cervical dislocation. The peritoneal cavity was opened under sterile conditions, and mesenteric lymph nodes, Peyer's patches, and nasal mucosa-associated lymphoid tissue were isolated. Lymph nodes were immediately placed in a centrifuge tube containing pre-chilled RPMI-1640 complete medium (containing 10% fetal bovine serum, 100 U / mL penicillin, 100 μg / mL streptomycin, and 2 mM L-glutamine).

[0061] 2) Preparation of lymph node single-cell suspension: Place the lymph node in a sterile culture dish and gently grind with a glass grinder to release the cells. Filter the cell suspension through a 70 μm cell sieve. Centrifuge the filtered cell suspension at 800 rpm for 5 minutes, discard the supernatant, and resuspend in RPMI-1640 complete medium. Stain with trypan blue and count the cells. Adjust the cell concentration to 1×10 6 cells / mL.

[0062] 3) Cell culture: Cells were seeded in 24-well plates, with 1 mL per well (containing 1×10 6 cells) and cultured in a 37°C, 5% CO2 incubator for 48 hours.

[0063] 4) Supernatant collection and ELISA detection: After the end of culture, the cell supernatant was collected carefully, centrifuged at 1200 rpm for 5 minutes to remove cell debris, and the supernatant was collected and stored at -80°C for detection. Detection was performed according to the instructions of the mouse IgA ELISA kit. The steps included coating, blocking, sample addition, secondary antibody incubation, substrate color development, and reaction termination. The absorbance value was read at 450 nm wavelength using a microplate reader, and the IgA concentration was calculated according to the standard curve.

[0064] 11. Western Blot detection

[0065] After equal dilution, the mouse serum samples were dissolved in SDS sample buffer under non-reducing conditions and electrophoretically separated in a 4-12% gradient SDS-PAGE gel to distinguish between monomeric IgA (mIgA) and polymeric IgA (pIgA). The proteins were then transferred to a polyvinylidene fluoride membrane (PVDF membrane, Millipore), and Western blot analysis was performed using horseradish peroxidase (HRP)-labeled goat anti-mouse IgA antibody (Bethyl A90-134A Goat anti-Mouse Albumin Antibody Affinity Purified). All membrane strips were developed by enhanced chemiluminescence (Enhanced Chemiluminescence, ECL, GE Healthcare).

[0066] II. Results and analysis

[0067] 1. Overall situation of PM2.5 chronic exposure model

[0068] A total of 30 mice aged 6 weeks were divided into PM2.5 exposure modeling group and control group, with 10 mice in each group. There were no accidental deaths of mice in the laboratory, and all mice completed the study.

[0069] 2. Effect of PM2.5 chronic exposure on mouse body weight

[0070] The weight of the mice was recorded. At 1 month after modeling, the weight of the mice in the control group was 22.3±1.2g, and the weight of the mice in the PM2.5 exposure group was 21.9±0.4g. There was no difference in weight between the two groups of mice (P=0.616). At 2 months after modeling, the weight of the mice in the control group was 30.0±3.7g, and the weight of the mice in the PM2.5 exposure group was 22.0±1.5g. There was a significant difference in weight between the two groups of mice (P=0.025). At 6 months after modeling, the weight of the mice in the control group was 35.1±0.5g, and the weight of the mice in the PM2.5 exposure group was 23.1±1.8g. There was a significant difference in weight between the two groups of mice (P<0.001). 3 months after leaving the PM2.5 environment, the weight of the mice in the PM2.5 exposure group was similar to that at 6 months after modeling. Table 1 shows the changes in mouse weight, as follows:

[0071] Table 1. Changes in mouse body weight

[0072]

[0073] 3. Changes in proteinuria in mice chronically exposed to PM2.5

[0074] One month after modeling, urinary albumin levels in the control group were 2946.8±3264.5 ng / ml, while those in the PM2.5-exposed group were 13454.4±1915.7 ng / ml, indicating a significant difference between the control group and the PM2.5-exposed group (P=0.028). Six months after modeling, urinary albumin levels in the control group were 3984.6±2860.5 ng / ml, while those in the PM2.5-exposed group were 108665.7±25567.1 ng / ml, indicating a significant difference between the two groups (P=0.028). Three months after leaving the modeling environment, proteinuria in the PM2.5-exposed group remained significantly higher than in the control group (P=0.027). Urinary albumin levels in mice at each time point are shown in Table 2.

[0075] One month after modeling, urinary UACR in the control group was 12.5±13.9 mg / gCr, while that in the PM2.5-exposed group was 34.4±13.4 mg / gCr. Urinary albumin levels in the modeling group were significantly higher than those in the control group (P=0.179). Six months after modeling, urinary albumin levels in the control group were 11.7±10.6 mg / gCr, while those in the PM2.5-exposed group were 11.7±10.6 mg / gCr, with a significant difference between the two groups (P=0.004). Three months after leaving the modeling environment, proteinuria in the PM2.5-exposed group remained significantly higher than that in the control group (P<0.001). UACR levels in mice at each time point are shown in Table 3.

[0076] Table 2. Urinary albumin levels in mice (ng / ml)

[0077]

[0078] Table 3. Urinary Albumin-to-Cratinine Ratio Levels in Mice (mg / gCr)

[0079]

[0080] 4. Changes in blood urine of PM2.5 chronically exposed mice

[0081] The urine of mice was detected by urine test paper. At 6 months, 2 mice in the model group had hematuria, and the rest of the mice had no hematuria. Figure 2 ).

[0082] 5. Changes in immunohistochemistry of kidney tissue of PM2.5 chronically exposed mice

[0083] The mesangial proliferation and the number of glomerular cells increased in the kidneys of PM2.5 model mice, and no crescent formation was observed; the tubular interstitium was basically normal, and no tubular necrosis and inflammatory cell infiltration was observed; no obvious abnormalities were observed in the renal blood vessels. Figure 3 We calculated the proportion of the mesangial area to the glomerular volume of mice, and the results are shown in Table 4. At 1 month of modeling, the mesangial cells of the model group showed mild proliferation, and there was no statistical difference with the control group (P=0.072). At 2 months, the mesangial cells of the PM2.5 model group showed proliferation, and the proportion of the mesangial area gradually increased with the extension of the exposure time. At 6 months of modeling, the proportion of the mesangial area of the model group was 0.38±0.04, and the proportion of the control group was 0.15±0.01, and there was a significant difference between the two groups (P<0.001). At 9 months of modeling, that is, 3 months after leaving the PM2.5 exposure environment, the proportion of the mesangial area of the model group was 0.35±0.02, and the proportion of the control group was 0.18±0.01, and there was still a significant difference between the two groups (P<0.001).

[0084] Table 4. Proportion of mesangial area to glomerular area of mice

[0085]

[0086] Immunofluorescence was used to evaluate the deposition of IgA and complement C3 in kidney tissue. At 1 month and 2 months, there was no IgA deposition and no C3 deposition in kidney tissue. At 3 months of modeling, IgA and C3 deposition began to appear in kidney tissue, and according to the fluorescence staining intensity, 2 mice were moderately positive, and 1 mouse was weakly positive. At 6 months of modeling, 2 mice were strongly positive, and 1 mouse was extremely strongly positive. At 9 months of modeling, the kidney tissue of 2 mice showed extremely strong fluorescence intensity. The IgA fluorescence intensity of kidney tissue of mice is shown in Table 5. In addition, we also observed that at 3 months, focal glomeruli showed IgA fluorescence positive, mainly distributed at the junction of the cortex and the medulla, and few subcapsular glomeruli showed IgA deposition. At 6 months and 9 months of modeling, diffuse glomerular IgA fluorescence was strongly positive. Figure 4 ).

[0087] At 3 months of electron microscopy modeling, endothelial cell proliferation with neutrophil infiltration, mesangial cell pairing, and electron-dense material deposition in the mesangial area were observed Figure 5 ). Electron-dense material deposition in the mesangial area was observed at 3 months, 6 months, and 9 months of modeling Figure 4 .

[0088] Table 5. IgA fluorescence intensity of mouse kidney tissue

[0089]

[0090] Double-label immunofluorescence results showed that IgA was co-localized with C3, IgA and mesangial cell marker protein PDGFRβ were co-localized, and IgA and C3 were co-localized, suggesting that IgA and C3 were deposited in the mesangial area of the glomerulus Figure 6 .

[0091] 6. Changes in serum IgA levels of PM2.5 chronically exposed mice

[0092] At 1 month of modeling, the serum IgA level of the modeling group was 821.50 ± 568.78 ug / ml, and the serum IgA level of the control group was 616.27 ± 344.64 ug / ml, with no statistically significant difference between the two groups (P = 0.620). At 2 months, 3 months, 6 months, and 9 months of modeling, the serum IgA level of the modeling group was significantly higher than that of the control group (Table 6).

[0093] In addition, we detected the level of macromolecular poly-IgA (pIgA) Figure 7 The levels of pIgA and monomeric IgA (mIgA) in the modeling group were higher than those in the control group, which was consistent with the trend of serum IgA in mice.

[0094] Table 6. Serum IgA level of mice (ug / ml)

[0095]

[0096] 7. Changes in serum creatinine and urea nitrogen of PM2.5 chronically exposed mice

[0097] At 1 month, 2 months, 3 months, 6 months, and 9 months, there was no statistically significant difference in serum creatinine and urea nitrogen between the modeling group and the control group, see Tables 7 and 8:

[0098] Table 7. Serum creatinine level of mice (mg / dl)

[0099]

[0100] Table 8. Serum urea nitrogen level of mice (mg / dl)

[0101]

[0102] 8. Mouse lymph node cell IgA secretion experiment

[0103] The IgA secretion of NALT, MLN and PP lymph nodes of the model group and the experimental group is shown in Table 9. When the model was established for 6 months, the IgA secretion of NALT of the model group was 16.37±1.70 ng / ml, which was significantly higher than that of the control group (0.79±0.33 ng / ml) (P<0.001). There was no statistical difference in the IgA secretion of MLN and PP lymph nodes between the model group and the control group.

[0104] Table 9. Results of mouse lymph node cell IgA secretion

[0105]

[0106] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for constructing a smoke-induced IgA nephropathy mouse model, characterized in that: After being raised in a clean environment for a certain period of time, the experimental animals in the model group were exposed to a high-concentration smoke environment during two predetermined time periods in the morning and afternoon, 7 days a week for 6 months; the experimental animals in the control group were raised in a clean air environment during the same period; after 6 months, the model group was removed from the polluted environment and continued to be raised in a clean environment together with the control group.

2. The construction method according to claim 1, characterized in that The experimental animals were selected from 6-week-old C57BL / 6 mice, housed in a specific pathogen-free SPF environment, given a standard diet, and controlled in an environmental temperature of 22°C, a humidity of 50–60%, and a stable 12-h light-dark cycle.

3. The construction method according to claim 2, characterized in that The mice in the model group were exposed to a high concentration of PM2.5 environment for two hours in the morning and afternoon respectively.

4. The construction method according to claim 3, characterized in that The mice in the model group were exposed to a high-concentration smoke environment from 8:00 to 10:00 in the morning and from 14:00 to 16:00 in the afternoon every day.

5. The construction method according to claim 1, characterized in that The high-concentration smog environment refers to a concentration that exceeds the average PM2.5 concentration limit within 24 hours.

6. The construction method according to claim 1, characterized in that After 6 months, the model group was removed from the polluted environment and continued to be raised in a clean environment with the control group for another 3 months.

7. A smoke-induced IgA nephropathy mouse model, characterized in that: The method according to any one of claims 1 to 6 is used to construct the 8. Use of the smoke-induced IgA nephropathy mouse model according to claim 7 in IgA nephropathy drug screening.

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