The Correlation Between Microtubule-associated Protein 1 Light Chain 3(LC3) And Life-span In Rats

Objective:To observe the discrepancy of autophagy and the expression of microtubule-associated protein 1 light chain 3(LC3) in aged rats with different dietary, to analyze experimental animal's natural life-spans and survival curves, and to inquire into the Relativity between LC3 and rats life. In order to make clear cell autophagy is highly active whether conducive to the life extension.Methods:Forty-five female 24-month aged SD rats were randomly and evenly divided into 3 groups: groupâ… (control group), groupâ…¡(every-other-day ad libitum feeding rats, which spend one day of their time fed and the next day in the state of fasting) and groupâ…¢(rats spend five days of their time fed and the next two days in the state of fasting). Then dietary intervention in different ways were implemented and samples were taken after 3 months. Autophagosomes were observed with Transmission Electron Microscopy, Western blot detect the expression of LC3, which is the marker proteins for rat liver tissue autophagy. Analyzing on autophagy activity of cells, observe old rats natural life and the survival time. Comparing different of rats LC3 expression and occurrence autophagy and degree of difference in different groups. In addition, survival curves were drawn for survival analysis.Results:(1) Proportions of autophagosome to the total area of cytoplasm in groupâ…¡and groupâ…¢were significantly higher(p<0.01) than that in groupâ… , but no significant difference between the two groups (p>0.05). (2)Western blot shows that the ratio of LC3â…¡/LC3 I in groupâ… is relatively low,and the radio of groupâ…¡and groupâ…¢had a significant increase. (P<0.05). (3) Analyzing three groups of survival curves, survival rates of groupâ…¡and groupâ…¢were significantly higher than that of control group(p<0.01),whereas no statistical difference between the two groups (p>0.05). (4) The result of correlation analysis(rs=0.861) between rats survival time and autophagic activity indicated that there was a linear positive correlation between cells autophagy activity and rats survival time.Conclusions:(1) Two dietary restrictions way are enhanced rats liver cell autophagy, But enhance the degree of autophagy no obvious difference. (2) The expression of LC3 at high level may be benefit for extension of life-span in rats. (3) The autophagy is closely related to the life extension of rats.