An Experimental Study on the Expression of Beclin 1 and MAP1-LC3 in Avascular Necrosis of the Fem-oral Head Induced by Glucocorticoids

Abstract：Objective To investigate the expression of autophagy-related gene Beclin 1 and microtubule-associated protein 1 light chain 3(MAP1-LC3)in avascular necrosis of the femoral head model induced by glucocorticoids ,and ex-plore the role of autophagy in avascular necrosis of the femoral head model induced by glucocorticoids .Methods Forty mature Japanese rabbits were randomly divided into experimental group (n = 28)and control group(n = 12) .The experi-mental group was given an intramscular injection of 7 .5 mg/kg of methylprednisolone twice per week for 8 weeks in all ;the control group was given equal isotonic Na chloride .Rabbits of each group were killed at the 8th week respective-ly ,and the hibateral heads of femur were taken out .The left heads of femur were made into general sections ,dyed by HE .The expression of Beclin-1 and MAP1-LC3 were detected by immunohistochemical method .The right heads of fe-mur were put into liquid nitrogen quickly ,protein were extracted from bone tissue ,right head of femur was detected the protein expression of Beclin 1 and MAP1-LC3 by Western blot .Results Hematoxylin and eosin stain showed the suc-cessfuluccessful production of steroid induced avascular necrosis of the femoral head in rabbits .The expression of Beclin l and MAPI-LC3 in the experimental group were 96 .43％ and 92 .86％ respectively ,and the expression of Beclinl and MAPI-LC3 in the control group were 16 .67％ and 8 .33％ respectively .And the difference was significant (P < 0 .05) . Compared to the control group ,the protein expression of Beclinl and MAPI-LC3 increased remarkably in the experi-mental group ,the difference was significant (P < 0 .05) .Conclusion Adrenal cortex hormones cause the rabbits early avascular necrosis of the femoral head ,Beclin 1 and MAP1-LC3 expression increased .This study suggests that autoph-agy may play an important role in the development of femoral head model induced by glucocorticoids .