Posterior capsule opacification (PCO) is a common ocular fibrosis disease related to the epithelial-mesenchymal transition (EMT) of human lens epithelial cells (HLECs). However, safe and effective drugs that prevent or treat PCO are lacking. Metformin (Mtf) has been used to treat fibrosis-related diseases affecting many organs and tissues, but its effect on ocular fibrosis-related diseases is unclear. We investigated whether Mtf can inhibit EMT and fibrosis in HLECs to prevent and treat PCO and elucidated the potential molecular mechanism. Here, we established an HLEC model of TGF-β-induced EMT and found that 400 μM Mtf inhibited vertical and lateral migration and EMT-related gene and protein expression in HLECs. Smad2/3 are downstream molecules of TGF-β that enter the nucleus to regulate EMT-related gene expression during the occurrence and development of PCO. We revealed that Mtf suppressed TGF-β-induced Smad2/3 phosphorylation and nuclear translocation. Mtf induces AMP-activated protein kinase (AMPK) phosphorylation. In this study, we found that Mtf induced the activation of AMPK phosphorylation in HLECs. To further explore the mechanism of Mtf, we pretreated HLECs with Compound C (an AMPK inhibitor) to repeat the above experiments and found that Compound C abolished the inhibitory effect of Mtf on HLEC EMT and the TGF-β/Smad2/3 signalling pathway. Thus, Mtf targets AMPK phosphorylation to inhibit the TGF-β/Smad2/3 signalling pathway and prevent HLEC EMT. Notably, we first illustrated the AMPK/TGF-β/Smad2/3 signalling pathway in HLECs, which may provide a new therapeutic strategy for PCO.

后囊混浊 (PCO) 是一种常见的眼部纤维化疾病，与人晶状体上皮细胞 (HLEC) 的上皮间质转化 (EMT) 相关。然而，缺乏安全有效的预防或治疗 PCO 的药物。二甲双胍 (Mtf) 已被用于治疗影响许多器官和组织的纤维化相关疾病，但其对眼部纤维化相关疾病的影响尚不清楚。我们研究了 Mtf 是否可以抑制 HLEC 中的 EMT 和纤维化以预防和治疗 PCO，并阐明了潜在的分子机制。在这里，我们建立了 TGF-β 诱导的 EMT 的 HLEC 模型，发现 400 μM Mtf 抑制了 HLEC 中的垂直和横向迁移以及 EMT 相关基因和蛋白质的表达。Smad2/3是TGF-β的下游分子，在PCO的发生发展过程中进入细胞核调节EMT相关基因的表达。我们发现 Mtf 抑制了 TGF-β 诱导的 Smad2/3 磷酸化和核易位。Mtf 诱导 AMP 活化蛋白激酶 (AMPK) 磷酸化。在这项研究中，我们发现 Mtf 诱导 HLEC 中 AMPK 磷酸化的激活。为了进一步探索Mtf的作用机制，我们用Compound C（一种AMPK抑制剂）预处理HLECs重复上述实验，发现Compound C消除了Mtf对HLEC EMT和TGF-β/Smad2/3信号通路的抑制作用。因此，Mtf 靶向 AMPK 磷酸化以抑制 TGF-β/Smad2/3 信号通路并防止 HLEC EMT。值得注意的是，我们首先说明了 HLEC 中的 AMPK / TGF-β / Smad2 / 3 信号通路，