Effects Of Dietary Restriction&Vitamin D On Beclin1Expression

In addition to apoptosis，cell autophagy has become one of the points hotly discussed inrecent years. It is confirmed that autophagy is not only a form of cell death but also a kind of cellself-protecting mechanism. Autophagy plays an important role in aging, cancer and neurodegen-erative disorder related to cell proliferation and death. Aging is a general decline in organicfunction as well as a decrease in adaptiveness to change and to restore disrupted homeostasis.There are changes of lysosome system and enzymology in aging tissue. As the growth of age,the role of cell autophagy began to abate, which cause the ability of adapting to the environmentand own defense reaction to reduced. Damaging cell structure and large of reaction oxygencompounds such as oxygen free radicals can’t effectively remove, which lead to the changes ofcell steady state and speed up the process of aging. So to maintain normal cellular function ofautophagy is closely related to aging and lifetime.Objective To investigate rat renal cortical cells and liver cells autophagy induced by VD&dietary restriction and the expression of autophagy-related protein Beclin1. Test the length oftelomere for speculate the life span of rat to make sure whether VD inducing autophagy canprolong life and look for new ways to slow the speed of aging.Methods18-month-aged rats were randomly grouped by weight into four groups：controlgroup（group A）、VD group (group B)、dietary restriction group (group C) and VD combinedwith dietary restriction group (group D), which were fed for twenty weeks by different dietaryand VD. Dietary restriction use5:2diet method(i.e.5“normal” eating,2“limiting” diet); Thedose of VD is1(μg/kg)/d. Use TEM (transmission electron microscope) to observe the amount ofautophagy vacuoles in rat liver cells and detect the expression of autophagy-related proteinBeclin1in renal cortical cells of aged rats by Immunohistochemistry and RT-PCR(reversetranscription-polymerase chain reaction). Use Flow-fish to measure the telomere length oflymphocytes in rat to estimate the span life of rats.Results (1) Typical morphological changes of autophagy in liver cells can be seen underTEM. Compared with group A, The proportions of autophagosome to the total area of cytoplasmin groupB、C、D were significantly higher(P<0.05). The ratio of autophagosome in group D ishigher than group B or group C(P<0.05).(2) Compare to group A, the ratio of the amount ofBeclin1among group B、group C and group D increased significantly(P <0.05). In addition, theexpression of Beclin1in group D is higher than that in group C or groupD (P<0.05). There is nostatistical meaning between group B and group C.(3) Flow-fish： the telomere length oflymphocytes in group B、C、D is longer than that in group A(P<0.05). Furthermore the telomere length of lymphocytes in group D is longer than group B or group C(P<0.05).Conclusion1.The detection methods of TEM prove that VD and dietary restriction enhancethe probability of autophagy in cells.2.Both VD and dietary restrictioncan improve the contentof protein Beclin1for futher illustrating that VD and dietary restriction can induce autophagyoccurs.3. The level of Beclin1induced by the VD combined with dietary restriction madesignificant difference compared with singled VD group or dietary restriction group, which showthat different signaling pathways maybe occur in rat cells autophagy induced by VD and dietaryrestriction. And4.VD and dietary restriction increase the the telomere length of lymphocytes,but we need to explore the the relation between VD and dietary restriction.