The Research Of The Effect Of Autophagy On The Apoptosis Of Mutton

Meat is the major source of animal protein for human,and it is also indispensable in human diet.One kind of Chinese famous dairy goat is Guanzhong dairy goat.Obviously,there are large numbers of dairy goats in China,so dairy goat enterprises are very concerned about recycling value of dairy goats' meat after they lost their value of producing milk.One of the most significant factors to decide the quality of mutton is tenderness,and dairy goats are mostly adult goats,so to improve the tenderness of their meat is a key technical problem for meat enterprises.We focused on the Guanzhong dairy goat,the local characteristics in Shaanxi provience,as the object to explore the mechanism of autophagy on apoptosis in skeletal muscle cells and the mechanism of improving mutton tenderness.We aimed on finding the mechanism of meat tenderness and the way to promote the tenderness in this study.Follows are the contents and results:1.To investigate the occurrence of autophagy during the maturation of mutton.As known that there is a bloodletting hypoxia ischemia environment in meat after animals' being slaughtered,however,whether autophagy happened in the skeletal muscle cells during the maturation of mutton is unknown.Besides during the autophagy,the expression of Becline-1 and LC-3 is important indexes for detecting autophagy occurs.This research we kept the normal goat longissimus muscle(LD)at 4? for respectively,0,1,3,and 5 days,then their cytoplasmic extraction samples were detected by Western blot for examining the expression of Becline-1 and LC3.The results demonstrated that the expression of Becline-1 and LC3 on 1,3 and 5 days was significantly higher than 0 day's.2.To investigate the effect of rapamycin(RPA)and 3-methyladenine(3-MA)treatment on autophagy in skeletal muscle cells of dairy goats.RPA and 3-MA are respectively inducer and inhibitor of the autophagy,so dairy goat LD was incubated in RAP and 3-MA as treatments,and was also incubated in saline as a control,in this study,then used Western blot to detect the expression of the mark protein in autophagy,Beclin-1 and LC3.The results showed that the expression of Becline-1 and LC3 in rapamycin treatment group were significantly higher than in the control group,and 3-MA treatment group showed opposite results.It is proved that RPA and 3-MA incubation can regulate autophagy in the skeletal muscle cells of dairy goat.3.To verify the effect of autophagy on apoptosis of goat skeletal muscle cells.Dairy goat LD was incubated in RAP and 3-MA as treatments,and was also incubated in saline as a control in this study,then detected the expression of the marker protein in apoptosis,Cleaved Caspase-3 and Caspase-3 by Western blot.The results showed that the expression of Caspase-3 and Cleaved Caspase-3 in RPA treatment group were clearly higher than in control group,and results of 3-MA treatment group are contrasted.We conclude that RPA and 3-MA incubation treatment can regulate the apoptosis through autophagy in the skeletal muscle cells of dairy goat.4.To examine the effect of RPA and 3-MA on tenderness of dairy goats.In this study,dairy goat LD was treated by RPA and 3-MA,and was also incubated in saline as a control,then expression of Desmin was detected by Westernblotting.The results showed that after treated with RPA,the degradation of Desmin in the skeletal muscle cells of dairy goat was higher than the control group,while the 3-MA treatment showed opposite results.It suggests that the regulation of meat tenderness may be mediated by autophagy in goat goat skeletal muscle cells.5.To examine the effect of RPA and 3-MA on the apoptosis of skeletal muscle cells in dairy goats.The dairy goat LD samples were treated by RAP and 3-MA in this experiment,and the expression of the main protein in apoptosis was detected by Western blot,such as Fas,FasL,Caspase-8 in the death receptor pathway and Bcl-2,Bax,Caspase-9,Cytosolic cytochrome C in the mitochondrial pathway.These results showed that after rapamycin treated,the expression of Fas,the expressions of Fas-L,Bax and /Bcl-2 were clearly higher than the control group's,while the expression of Caspase-8 and Caspase-9 was significantly lower than the control group's.Besides,3-MA treatment showed opposite results.It is proved that the autophagy of dairy goat skeletal muscle cells regulates apoptosis through two pathways: death receptor pathway and mitochondrial pathway.Moreover,the regulation of Caspase-3,which is an important enzyme of apoptosis,could control the degradation of Desmin,who is able to adjust the tenderness of mutton.