| Idiopathic inflammatory myopathy(IIM)are systemic autoimmune diseases characterized by progressive muscular atrophy caused by chronic muscle inflammation.According to its clinical characteristics,muscle histopathology and immunological characteristics,it is divided into several types,including dermatomyositis(DM),polymyositis(PM),sporadic inclusion body myositis(IBM)and necrotizing autoimmune myopathy(NAM).Although previous studies have shown that inflammatory myopathy is characterized by acute or subacute progressive myasthenia and inflammatory cell infiltration of endometritis,but because its etiology and pathological mechanisms are not clear,the current clinical treatment of inflammatory myopathy is mainly hormone,immunosuppressive agents and biological agents are dominant,but due to the lack of specificity,the treatment of inflammatory myopathy has clinically demonstrated a large number of drug side effects.Therefore,only by looking for the pathogenesis of inflammatory myopathy,to identify the key immune regulatory pathways for its occurrence and development,to find specific diagnostic and disease activity indicators and drug treatment targets,to elucidate the pathophysiology of inflammatory myopathy And treatment options can pave the way for clinical cure for inflammatory myositis.Although the exact pathogenesis of inflammatory myopathy is unclear,inflammatory myopathy is thought to be caused by interactions between genetic factors,infections,environmental factors,and lymphocyte disorders.At present,a large number of studies have shown that the autoimmune mechanism is the key link in the occurrence and development of such diseases.Among them,cytokines and cell chemokines play an important role in the initiation and progression of inflammatory myopathy.Cytokine is a low-molecular-weight soluble protein produced by various cells induced by immunogens,mitogens or other stimulators.It regulates innate and adaptive immunity,hematopoiesis,cell growth,and damaged tissue repair.Features.Currently,cytokines are involved in the development and pathogenesis of inflammation and or autoimmune diseases mainly through secretion.Interleukins are a class of multifunctional cytokines produced by many types of cells.It has been found that interleukins regulate many physiological processes by modulating immune responses and inflammatory responses.Its signal dysregulation in inflammation and immune response may lead to the initiation and maintenance of some diseases,such as inflammatory bowel disease,multiple sclerosis and the like.It mainly functions by regulating lymphocyte differentiation and recruiting to inflammatory regions and up-regulating other cytokines and chemokines.At the same time,interleukins also play an important role in many experimental autoimmune diseases,such as inducing rheumatoid arthritis and experimental autoimmune meningitis.Compared with these studies,there are relatively few studies on interleukins in inflammatory myopathy at home and abroad.Interleukin-37(IL-37)is a recently identified member of the interleukin-1(IL-1)family and has been found to play an important role in the regulation of inflammation as a key anti-inflammatory cytokine.It has been reported that IL-37 can play a key role in gouty arthritis by partially regulating the inflammatory process of MSU crystals in a partial MerTK-dependent manner.At the same time,both in vivo and in vitro studies have found that Smad3 is involved in the immunosuppressive and anti-inflammatory properties of IL-37,and blocking the activation of Smad3 or reducing the expression of Smad3 reduces the anti-inflammatory activity of IL-37.It is suggested that Smad3-mediated changes in IL-37 play an important role in immunosuppression and anti-inflammatory.However,the function and mechanism of action of IL-37-Smad3 signaling pathway in the development of inflammatory myopathy is still largely unknown.Therefore,in this study,we explored the correlation between EAM and the validation factor IL-37 by constructing an experimental autoimmune myositis model and verified that IL-37 is involved in pertussis toxin-induced inflammatory myopathy.The role of IL-37 in the regulation of pertussis toxin-induced inflammatory myopathy is based on the molecular mechanism of IL-37 regulation of pertussis toxin-induced inflammatory myopathy.Studies have shown that experimental experimental immunomyositis Lewis rat model established by immunization of rats with myosin(10 mg/kg),complete Freund's adjuvant(CFA)and pertussis toxin(PTX)meets the ideal experimental immunity.An animal model of myositis;IL-37 can improve inflammatory myopathy by reducing the levels of CK and inflammatory factors IL-1?,IL-6,TGF-?1 and TNF-a;further analysis found that IL-37 can regulate itself Smad3 in an immunomyositis Lewis rat model to prevent an inflammatory response.This study not only provides a theoretical basis for IL-37 regulation of pertussis toxin-induced inflammatory myopathy,but also provides a potential target for the treatment of inflammatory myopathy,which is of great significance for the treatment of inflammatory myopathy.Part I IL-37 inhibits the function of pertussis toxin-induced inflammatory myopathyObjective:By constructing an experimental immunomyositis(EAM)animal model,the levels of TNF-a,IL-6,IL-1?,TGF-?1 and CK in the EAM model were determined to mine inflammatory factors associated with experimental immunomyositis;To verify the role of the inflammatory factor IL-37 in an experimental immunomyositis(EAM)animal model.Methods:1.An experimental animal model of immunomyositis was established by immunizing rats with myosin(10 mg/kg),complete Freund's adjuvant(CFA)and pertussis toxin(PTX);the model of autoimmune myositis Lewis rat was established.Treatment was divided into 2 groups:group A(PTX group),intraperitoneal injection of pertussis toxin(PTX)once a week for 2 weeks;group B(PTX+IL-37 group):after the injection of PTX,the sixth week began 3 ?g of IL-37 was injected intraperitoneally once a week for 5 weeks.2.HE and Masson staining were used to assess pathological changes in lung and muscle tissue;3.ELISA was used to assess the expression of the regulatory factors TNF-a,IL-6,IL-1?,TGF-?1 and CK;4.All values are expressed as meansąstandard deviation(SD)and statistical analyses were performed with SPSS 17.0(SPSS,Inc.,Chicago,IL,USA).The t test was used to evaluate the differences between groups,and one-way analysis of variance(ANOVA)was used to evaluate the differences when more than 2 groups were compared.P<0.05 was considered as statistically significant.Results:1.Compared with the control group,HE staining analysis of the Lewis rat model group revealed mononuclear cell infiltration into muscle tissue;Masson trichrome staining to assess histological changes in the lung injury stage revealed that the tissues of mice administered with PTX showed more Fibrosis and muscle fiber atrophy;similar inflammation was observed in lung tissue in EAM mice,indicating myosin(10 mg/kg),complete Freund's adjuvant(CFA),and pertussis toxin(PTX).The experimental rat model of experimental immunomyositis can be used to simulate the limb weakness symptoms of human myositis and the typical pathological changes,which is in line with the ideal experimental animal model of immunomyositis.2.The level of CK in the serum of rats injected with PTX was significantly increased compared with the control mice;the cytokines IL-1?,IL-6,TGF-? and TNF-a associated with EAM were found by ELISA analysis.Significant increase in content;3.In the Lewis rat EAM model,IL-37 significantly reduced the histological damage of muscle and lung induced by PTX stimulation;at the same time,the greater the administration of PTX and IL-37 compared to rats administered only PTX,The levels of CK,IL-1?,IL-6,TGF-?1and TNF-a were significantly decreased in rats.Conclusion:The experimental immune myositis Lewis rat model established by immunizing rats with myosin(10 mg/kg),complete Freund's adjuvant(CFA)and pertussis toxin(PTX)meets the ideal experimental immunomyositis animal Model;significantly correlated with CK and inflammatory factors IL-1?,IL-6,TGF-?1 and TNF-a levels in EAM model;IL-37 can reduce CK and inflammatory factors IL-1?,IL-6.TGF-?1 and TNF-a levels improve inflammatory myopathy.Part II IL-37 regulates pertussis toxin-induced inflammatory myopathy by regulating Smad3Objective:By constructing the EAM model,the model was tested for PTX,PTX+IL-37 and PTX+IL-37+SIS3 to verify the molecular mechanism of IL-37 regulating pertussis toxin-induced inflammatory myopathy.Methods:1.EAM model was constructed using myosin(10 mg/kg),complete Freund's adjuvant(CFA)and pertussis toxin(PTX),and then the rats were divided into 3 groups for subsequent experiments:group A(PTX group),abdominal cavity Injecting pertussis toxin(PTX)once a week for 2 weeks;Group B(PTX +IL-37 group):After injection of PTX,3?g of IL-37 was injected intrapentoneally in the sixth week,once a week for 5 weeks.In the group C(PTX+IL-37+SIS3 group),10 ?mol Smad3 inhibitor SIS3 was injected through the tail vein on the basis of group B.2.HE and Masson staining to assess pathological changes in lung and muscle tissue;3.ELISA was used to assess the levels of the validation factors TNF-a,IL-6,IL-1?,TGF-?1 and CK.4.All values are expressed as meansąstandard deviation(SD)and statistical analyses were performed with SPSS 17.0(SPSS,Inc.,Chicago,IL,USA).The t test was used to evaluate the differences between groups,and one-way analysis of variance(ANOVA)was used to evaluate the differences when more than 2 groups were compared..P<0.05 was considered as statistically significant.Results:1 Histological analysis showed a significant decrease in muscle and lung injury induced by PTX stimulation after administration of IL-37 or IL-37 and SIS3 compared to the control group;Meanwhile,compared with the EAM group with PTX and IL-37,the muscle and lung injury of EAM rats was significantly enhanced administered with PTX+IL-37+SIS3.2.Consistent with changes in tissue lesions,the levels of CK,IL-1?,IL-6,TGF-?1,and TNF-a in the serum of EAM rats administered were significantly lower than those in the control group;The levels of CK,IL-1?,IL-6,TGF-?1 and TNF-a in the serum of EAM rats of PTX+IL-37+SIS3 were significantly increased in IL-37 EAM rats.Conclusion:By applying IL-37 and Smad3 inhibitor SIS3 to the EAM model,it was found that IL-37 can attenuate muscle and lung injury induced by PTX stimulation.Further analysis revealed that IL-37 regulates pertussis toxin-induced inflammatory myopathy by regulating the expression of Smad3. |
PDF Full Text Request