Expression Analysis Of Autophagy-related Factors In Lung Tissues Of Lambs Naturally Infected With OPA

Ovine pulmonary adenocarcinoma(OPA)is a common infectious lung tumor disease in sheep caused by jaagsiekte sheepretrovirus(JSRV)infection.The sick sheep showed progressive weight lossing,increased nasal fluid in the early stage,difficulty breathing in the later stage,and eventually died of suffocation.Earlier studies in our laboratory found that the expression levels of autophagy-related genes MAP1LC3B and BECN1 in later period lung tissues of adult sheep naturally infected with OPA were extremely significantly lower than those in healthy lung tissues.It is speculated that cell autophagy may be related to the pathogenesis of OPA.Moreover,the level of autophagy of cells varies at different stages of tumor de-velopment.In order to further study the role of cell autophagy in the tumorigenic mechanism of OPA,in this study,polymerase chain reaction(PCR),H.E staining,immunohistochemical staining(IHC)and western blotting(WB)assays were used to identify three early period lung tissues from healthy lambs and those naturally infected with OPA.Then,the OPA lung tissues were used as the test material,and the healthy lung tissues were used as the control group,IHC,quantitative real-time PCR(qPCR)and WB assays were used to detect the expression of autophagic genes MAP1LC3B,BECN1,SQSTM1 and their corresponding proteins LC3,Beclinl,P62.The IHC results showed that the localized expression of autophagy-related proteins in the OPA lung tissues and the control group were very similar,and LC3,Beclinl,P62 were mainly expressed in bronchiolar epithelial cells and alveolar epithelial cells in the control group,and mainly expressed in tumor-proliferating bronchiole epithelial cells,proliferating type II alveolar epithelial cells and infiltrating macrophages in the OPA lung tissues.The qPCR results showed that compared with the control group,the expression of MAP1LC3B gene was extremely significantly increased(P<0.01),the expression of BECN1 gene was significantly increased(P<0.05),while the expression of SQSTM1 gene was extremely significantly decreased(P<0.01)in the OPA lung tissues.The WB results showed that the expression of LC3 and Beclinl in the OPA lung tissues were significantly higher than those in the control group(P<0.05),while the expression of P62 in the OPA lung tissues was extremely significantly lower than that in the control group(P<0.01).The results indicated that the autophagy level in the naturally OPA-infected lambs early period lung tissues was significantly higher than that in healthy lambs,suggesting that the level of autophagy increased in order to resist the damage caused by the virus and maintain the stability of the internal environment when the virus invaded the body.This study provides basic informations for an in-depth study of the role of autophagy in the development of OPA.