二甲双胍对糖基化终末产物诱导的成纤维细胞凋亡及相关蛋白caspase-3、Bax及Bcl-2表达的影响

目的探讨晚期糖基化终末产物（AGEs）对原代人皮肤成纤维细胞凋亡的影响，以及二甲双胍（Metformin）对原代皮肤成
纤维细胞凋亡是否存在保护作用。方法取对数生长期的皮肤成纤维细胞，分为空白组，BSA对照组（300 μg/mL），AGEs刺激组
（100、200、300 μg/mL），药物组（AGEs 300 μg/mL+Metformin 1 mmol/L），采用CCK-8检测24、48、72 h细胞凋亡情况；Western
Blot检测细胞培养72 h后凋亡相关蛋白caspase-3、Bax、Bcl-2表达情况。结果CCK-8结果显示AGEs诱导皮肤成纤维细胞凋
亡呈浓度及时间依赖性，AGEs 300 μg/mL诱导72 h后可见细胞凋亡明显增多（0.72±0.02 vs 1±0.04，P<0.05），加入二甲双胍后可
对成纤维细胞起一定保护作用（0.98±0.02 vs 0.72±0.02，P<0.05）。Western Blot显示AGEs 300 μg/mL刺激成纤维细胞72 h后，
caspase-3、Bax 蛋白表达增加（P<0.05），而Bcl-2 蛋白表达下降（P<0.05），Bcl-2/Bax 比值下降（P<0.05），二甲双胍作用后
caspase-3、Bax蛋白表达水平较刺激组明显下降（P<0.05），而Bcl-2及Bcl-2/Bax比值则明显上升（P<0.05）。结论AGEs可诱导
人皮肤成纤维细胞凋亡增加，二甲双胍可以通过调控caspase-3、Bax及Bcl-2表达，从而起到抗凋亡作用。

Effects of metformin on apoptosis induced by advanced glycation end- products and expressions of caspase-3, Bax and Bcl-2 in human dermal fibroblasts in vitro

Objective To investigate the effect of metformin in protecting against advanced glycation end products
(AGEs)-induced apoptosis in human primary dermal fibroblasts. Methods Fibroblasts were exposed to 100, 200, or 300 μg/mL
AGEs, 300 μg/mL bovine serum albumin (BSA), or 300 μg/mL AGEs and 1 mmol/L metformin for 24, 48, or 72 h. The exposed
cells were examined for cell apoptosis using a cell counting kit. The expressions of caspase-3, Bax and Bcl-2 protein in the
fibroblasts treated for 72 h were detected with Western blotting. Results AGEs exposures caused significant dose- and
time-dependent apoptosis in the fibroblasts. A 72-h exposure to 300 μg/mL AGEs resulted in obviously increased apoptosis of
the fibroblasts compared to the control group (0.72 ± 0.02 vs 1 ± 0.04, P<0.05), and metformin significantly decreased
AGEs-induced apoptosis (0.98 ± 0.02 vs 0.72 ± 0.02, P<0.05). The expressions of caspase-3 and Bax protein were significantly
increased (P<0.05) and Bcl-2 protein expression was decreased (P<0.05) with a lowered Bcl-2/Bax ratio in AGEs-treated
fibroblasts (P<0.05), and such changes were significantly reversed by metformin treatment (P<0.05). Conclusion Metformin can
antagonize AGEs-induced apoptosis in human dermal fibroblasts by regulating the expressions of caspase-3, Bax and Bcl-2.