Application of AhR agonist in preparation of medicine for treating radiation pneumonitis

Abstract

The invention is applicable to the technical field of biological medicines, and provides application of an AhR agonist in preparation of a medicine for treating radiation pneumonitis, the AhR agonist can relieve pathological changes of RIP mice, including intestinal tissue crypt atrophy, distortion, infiltration of inflammatory cells in each layer of intestinal wall and intestinal mucosa thinning; the expression quantity of IFN-gamma, IL-2, IL-4 and TGF-beta is reduced; sOD expression is improved, and MDA expression is reduced; the administration mode of the medicine is oral administration. The invention proves that the occurrence and development of radiation pneumonitis caused by chest radiotherapy can be effectively improved by oral administration of the AhR agonist, a brand-new strategy is provided for treatment of radiation pneumonitis, the application has important clinical guiding significance, and the problem that current clinical treatment means are relatively deficient is effectively relieved.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine technology, and in particular relates to the application of AhR agonists in the preparation of drugs for treating radiation pneumonia. Background Art

[0002] Radiotherapy plays an important role in the clinical treatment of thoracic malignancies. However, this treatment process will inevitably cause radiation damage to the surrounding normal lung tissue. Radiation-induced lung injury includes early partially reversible radiation-induced pneumonitis (RIP) and late irreversible pulmonary fibrosis. RIP usually occurs within 4-8 weeks of chest irradiation. DNA damage and ROS generation caused by ionizing radiation activate intracellular signal transduction, induce oxidative stress and inflammatory response, promote the recruitment of various immune cells to the alveolar interstitium, and release various molecules and cytokines, thereby exacerbating the inflammatory response. When a variety of inflammatory factors and inflammatory cells gather in the damaged lung tissue, fibroblasts are activated, leading to excessive production and deposition of collagen, and eventually causing irreversible late-stage radiation-induced pulmonary fibrosis, resulting in reduced gas exchange and chronic respiratory failure. There is currently no effective treatment. Although some RIP patients have relieved their symptoms after receiving steroid hormone treatment during the acute inflammatory period, most patients will continue to develop radiation-induced pulmonary fibrosis. Therefore, it is particularly important to study drugs to control the occurrence and development of RIP.

[0003] As the "second genome", the intestinal flora produces active derivatives that can penetrate into the circulatory system and participate in regulating the functions of distal organs and the progression of various related diseases. In particular, the intestinal tract and the lungs form a "gut-lung axis" due to their similar mucosal environment and the combined effects of immune factors and metabolites. When the metabolites produced by the intestinal flora enter the peripheral blood, they can be retained in the lungs and react using the "gut-lung axis". Interference with the homeostasis of the intestinal flora through factors such as diet, antibiotics or disease can lead to changes in the composition of metabolites, thereby affecting the progression and susceptibility of lung diseases.

[0004] Aryl Hydrocarbon Receptor (AhR), an important regulator of intestinal homeostasis, has been shown to mediate "gut flora-host" interactions. AhR is a ligand-dependent transcription factor that is widely expressed in barrier tissues such as immune cells, epithelial cells, endothelial cells, and stromal cells in the intestinal and lung tissues. In the inactive state, AhR forms a complex with a variety of chaperone proteins in the cytoplasm. Once bound to the ligand, the AhR-ligand complex will shuttle to the nucleus, interact with the exogenous response element (XRE), and initiate transcriptional regulation of downstream target genes such as human cytochrome P450 (CYP) 1A1 and CYP1A2. Natural AhR ligands are mainly derived from indole and tryptophan metabolism in the diet, such as indole from cruciferous vegetables and tryptophan metabolites from microbial flora. AhR activated by dietary ligands can regulate the homeostasis and function of immune cells in the intestine.

[0005] Based on the above background, the present invention proposes the use of AhR agonists in the preparation of drugs for treating radiation pneumonitis. Summary of the invention

[0006] The purpose of the present invention is to provide an application of an AhR agonist in the preparation of a drug for treating radiation pneumonitis, aiming to solve the problems raised in the above background technology.

[0007] The purpose of the present invention is achieved through the following technical solutions: Application of AhR agonists in the preparation of drugs for treating radiation pneumonitis.

[0008] Furthermore, the AhR agonist can alleviate the pathological changes of RIP mice, including atrophy and distortion of intestinal tissue crypts, infiltration of inflammatory cells in various layers of the intestinal wall, and thinning of the intestinal mucosa; reduce the expression of IFN-γ, IL-2, IL-4, and TGF-β; increase SOD expression and reduce MDA expression.

[0009] Furthermore, the drug is administered orally.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The present invention confirms that oral administration of AhR agonists can effectively improve the occurrence and development of radiation pneumonitis caused by chest radiotherapy, provides a new strategy for the treatment of radiation pneumonitis, has important clinical guiding significance, and effectively alleviates the problem of the relative scarcity of current clinical treatment methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1This is the establishment and identification of the RIP mouse model in Example 1; wherein a is the comparison of the chest appearance of mice in the IR group and the Con group after whole thoracic irradiation, b is the comparison of the intestinal tissue morphological changes of mice in the IR group and the Con group after whole thoracic irradiation, c is the H&E staining result of the lung tissue, and d is the H&E staining result of the intestinal tissue.

[0012] Figure 2 is the identification result of the RIP mouse model in Example 1; wherein a is the expression of inflammatory factor IFN-γ in alveolar lavage fluid, b is the expression of inflammatory factor IL-2 in alveolar lavage fluid, c is the expression of inflammatory factor IL-4 in alveolar lavage fluid, d is the expression of inflammatory factor TGF-β in alveolar lavage fluid, e is the change of SOD expression level in lung tissue, and f is the change of MDA expression level in lung tissue; sample number n=3, * P <0.05.

[0013] Figure 3 These are the H&E staining results of lung tissue and intestinal tissue in Example 2.

[0014] Figure 4 The changes of RIP related indicators in different treatment groups in Example 2; a is the expression of inflammatory factor IFN-γ in alveolar lavage fluid, b is the expression of inflammatory factor IL-2 in alveolar lavage fluid, c is the expression of inflammatory factor IL-4 in alveolar lavage fluid, d is the expression of inflammatory factor TGF-β in alveolar lavage fluid, e is the change of SOD expression level in lung tissue, and f is the change of MDA expression level in lung tissue; sample number n=3, * P <0.05. DETAILED DESCRIPTION

[0015] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0016] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0017] Example 1. Six-week-old C57BL / 6 mice were divided into a control group (Con group) without whole thoracic irradiation and an irradiation group (IR group). The whole thorax (other parts were shielded by lead plates) of the mice in the IR group was irradiated with 20 Gy (2.0 Gy / min) using an X-RAD biological irradiator. The voltage was 180 kV and the target-skin distance was 70 cm. Six weeks after irradiation, the mice in both groups were killed at the same time. The occurrence of RIP was verified by H&E staining, and the corresponding tissues (lung tissue and intestinal tissue) were taken for subsequent research.

[0018] Compared with the Con group, the chest of mice in the IR group showed hair loss or whitening of hair color ( Figure 1 Middle a), the intestine is slightly contracted ( Figure 1 H&E staining showed that the normal structure of lung tissue in the IR group was destroyed, the alveolar wall was thickened, the interstitial edema, and the inflammatory cell infiltration increased ( Figure 1 Middle c); Structural changes such as crypt atrophy and distortion appeared in the intestinal tissue, and the infiltration of inflammatory cells in various layers of the intestinal wall increased ( Figure 1 ELISA was used to detect the expression of inflammatory factors in the bronchoalveolar lavage fluid of mice. The results showed that the expression of inflammatory factors (IFN-γ, IL-2, IL-4, TGF-β) in the bronchoalveolar lavage fluid of the IR group increased ( Figure 2 The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in lung tissue were detected using a kit to evaluate the oxidative stress level in the lungs of each group of mice. The results showed that the SOD content in the IR group was reduced ( Figure 2 e), MDA content increased ( Figure 2 (middle f).

[0019] Example 2, detection of RIP-related indicators in different treatment groups; The RIP-related indices of the Con group, IR group, ABX+IR group and AhR+IR group were detected.

[0020] Con group: mice without whole thoracic irradiation; IR group: mice were irradiated with 20 Gy (2.0 Gy / min) to the whole thorax; ABX+IR group mouse model: mice were treated with antibiotic complex (penicillin, neomycin, metronidazole, and vancomycin) for 2 consecutive weeks to disrupt their intestinal microbiota, and whole thorax irradiation of 20 Gy (2.0 Gy / min) was given on day 15; AhR+IR group mouse model: The AhR activator Ficz (30ug / kg) was given by oral gavage every other day from day 1 to day 9, and the whole thorax was irradiated with 20 Gy (2.0 Gy / min) on day 10.

[0021] Six weeks after irradiation, lung tissues, intestinal tissues and bronchoalveolar lavage fluids of mice in each group were collected. The degree of inflammatory cell infiltration in the lung and intestinal tissues of mice was evaluated by H&E staining; the expression of INF-γ, IL-2, TGF-β, and IL-4 in bronchoalveolar lavage fluid was detected by ELISA; the contents of SOD and MDA in the lung tissues of mice were detected using a kit.

[0022] The H&E staining results of lung tissue and colon tissue showed that ( Figure 3), compared with the Con group, the lung tissue structure of the IR group, ABX+IR group and AhR+IR group was destroyed, the alveolar wall was thickened, and the inflammatory cells increased. The ABX+IR group was more serious than the IR group, and the AhR+IR group was less serious than the IR group. Compared with the Con group, the intestinal tissue crypts of the IR group, ABX+IR group and AhR+IR group showed structural changes such as atrophy and distortion, inflammatory cells infiltration in all layers of the intestinal wall, and thinning of the intestinal mucosa. The ABX+IR group was more serious than the IR group, and the AhR+IR group was less serious than the IR group.

[0023] ELISA test results showed that ( Figure 4 ad), compared with the Con group and AhR+IR group, the expression levels of inflammatory factors (IFN-γ, IL-2, IL-4, and TGF-β) in bronchoalveolar lavage fluid of the IR group and ABX+IR group were increased.

[0024] The levels of SOD and MDA in lung tissue were measured to evaluate the oxidative stress level in the lungs of each group of mice. Figure 4 In e and f), compared with the Con group and the AhR+IR group, the SOD expression of the IR group and the ABX+IR group was decreased, and the MDA expression was increased, indicating that the oxidative stress level of the IR group and the ABX+IR group was lower than that of the Con group and the AhR+IR group. In addition, the oxidative stress level of the AhR+IR group was higher than that of the Con group.

[0025] The above results show that oral administration of AhR agonists can alleviate the pathological changes of RIP mice, including atrophy and distortion of intestinal tissue crypts, infiltration of inflammatory cells in various layers of the intestinal wall, and thinning of the intestinal mucosa; reduce the expression of IFN-γ, IL-2, IL-4, and TGF-β; increase SOD expression and reduce MDA expression. These findings confirm that oral administration of AhR agonists can effectively improve the occurrence and development of radiation pneumonitis caused by chest radiotherapy, provide a new strategy for the treatment of radiation pneumonitis, have important clinical guidance significance, and effectively alleviate the problem of the relative lack of current clinical treatment methods.

[0026] The above are only preferred embodiments of the present invention. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These should also be regarded as the protection scope of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. Application of AhR agonists in the preparation of drugs for the treatment of radiation pneumonitis.

2. The use of the AhR agonist according to claim 1 in the preparation of a drug for treating radiation pneumonitis, characterized in that: The AhR agonist can alleviate the pathological changes of RIP mice, including atrophy and distortion of intestinal tissue crypts, infiltration of inflammatory cells in various layers of the intestinal wall, and thinning of the intestinal mucosa; reduce the expression of IFN-γ, IL-2, IL-4, and TGF-β; increase SOD expression and reduce MDA expression.

3. Use of the AhR agonist according to claim 1 in the preparation of a drug for treating radiation pneumonitis, characterized in that: The drug is administered orally.

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