Mechanism of hyperhomocysteinemia induced renal injury in CBS+/- mice / 中国组织工程研究

ABSTRACT

BACKGROUND: In chronic kidney disease, there is often an increase in the level of homocysteine, which can lead to podocyte apoptosis, but the specific mechanism is not clear. OBJECTIVE: To investigate the mechanism of hyperhomocysteinemia-induced renal injury in Cbs+/- mice. METHODS: Cbs+/+ mice (control group) and Cbs+/- mice (model group) with similar body weight were selected, with 10 mice in each group, and were fed with high methionine diet. After 8 weeks, the mice were killed, the serum was separated and the kidney tissue was obtained. The levels of serum homocysteine, urea nitrogen and creatinine were measured by automatic biochemical analyzer. The renal injury was observed by Periodic Acid-Schiff staining and transmission electron microscope. TUNEL staining was used to observe the apoptosis of glomeruli. The protein expression levels of Bax, Bcl-2 and caspase12 were detected by western blot. RESULTS AND CONCLUSION: Compared with Cbs+/+ mice, the level of serum homocysteine, urea nitrogen and creatinine in Cbs+/- mice were significantly increased (P < 0.01). The Periodic Acid-Schiff staining results showed that the glomerular basement membrane of Cbs+/+ mice was clear and the thickness was uniform, while the Cbs+/- mouse glomerular basement membrane showed varying degrees of uneven thickness, widening of membrane area and thickening of matrix. Under the transmission electron microscope, the glomerular basement membrane of Cbs+/+ mice was clear and the foot process was regular, while the glomerular basement membrane of Cbs+/- mice was locally thickened and the foot process was irregular fusion. TUNEL staining showed that the number of apoptotic cells in glomeruli of Cbs+/- mice was significantly increased compared with Cbs+/+ mice; meanwhile, western blot detection showed that the protein levels of Bax/Bcl-2 and caspase12 were significantly increased (P < 0.05). To conclude, podocyte apoptosis plays an important role in hyperhomocysteinemia-induced renal injury in Cbs+/- mice.