Preliminary Study On Apoptosis Of Lung Tissue In Ovine Pulmonary Adenocarcinoma

Ovine pulmonary adenocarcinoma(OPA)causes progressive wasting,cough and breathing difficulties,and the end of this disease is the death of infected animals.This disease caused great economic losses to the sheep breeding industry.Jaagsiekte sheep retrovirus(JSRV)is the causative agent of OPA,and the envelope protein(Envelope,Env)is the main oncogenic protein of JSRV.OPA lung tissue is considered to be a good research model for human lepidic predominant adenocarcinoma(LPA).Previous studies have shown that the formation of OPA is a long-term accumulated process in which multiple factors and genes participate in,and this process is also subject to the complex regulation of apoptosis-related factors.In order to explore the expression and the role of apoptosis-related factors plays in the naturally infected OPA lung tissues,we conducted the following experiments:(1)In order to determine the typical natural infections of OPA,this study uses Polymerase chain reaction(PCR)to preliminary screen the expression of JSRV env,combined with the pathological histology detection,screening characteristics of pathological changes of alveolar type II epithelial cells and bronchial epithelial cells proliferation,and typical "cauliflower-like" adenoma focal which is typical naturally infected OPA lung tissues.Immunohistochemistry(IHC)and Western blotting(WB)was used to screening the expression of JSRV Env.The results showed that 3 cases of lung tissue with natural infection of OPA were identified in 60 cases of lung tissue samples.(2)In order to explore the distribution of apoptosis-related factors in the lung tissues of OPA disease,the distribution of Bax,Caspase3 and Bcl-2 in the lung tissues of typical naturally infected OPA and healthy sheep was detected by IHC test.The results showed that Bax and Caspase3 mainly showed positive signals in the cytoplasm and cell membrane of proliferative alveolar type II epithelial cells and tumor cells,and Bcl-2 mainly showed positive signals in the cytoplasm of alveolar type II epithelial cells and tumor cells in typical naturally infected OPA lung tissues.In healthy lung tissues,Bax,Caspase3 and Bcl-2 were positively expressed in alveolar epithelial cells.(3)In order to explore the expression changs of related factors of apoptosis in the OPA lung tissue at the genetic level,the expression of Bax,Caspase3 and Bcl-2 were analysised by Real-time Quantitative polymerase chain reaction(RT-qPCR)in the typical naturally infected OPA lung tissues.The results showed that the expression of Bax and Caspase3 was lower than that in healthy one(p<0.05),and the expression of Bcl-2 was higher than that in healthy one(p<0.05).(4)In order to explore the expression changs of related factors of apoptosis in the OPA lung tissue at the protein level,the expression of Bax,Caspase3 and Bcl-2 were determined by WB in the typical naturally infected OPA lung tissues.The results showed that the expression of Bax and Caspase3 were lower than that in healthy one(p<0.05),while the expression of Bcl-2 was significantly higher than that in healthy one(p<0.01).In summary,when the expression of JSRV Env in the naturally infected OPA lung tissues,the expression of Bax and Caspase3 were decreased in the gene and the protein levels,and the expression of Bcl-2 was increased,and the level of apoptosis in the naturally infected OPA lung tissues was significantly lower than that in healthy one.That indicated the apoptosis was involved in the process of OPA tumorigenesis.This study made a preliminary study on the expression of apoptotic factors in the OPA tumorigenesis,and provided basic data for the relationship between apoptosis and OPA,apoptosis and LPA,apoptosis and tumorgenic mechanism.