Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.
Department of Endocrinology and Metabolism, Shenzhen People's Hospital, Second Affiliated Hospital of Jinan University, Shenzhen, Guangdong, China.
Exp Mol Med. 2020 Feb;52(2):266-280. doi: 10.1038/s12276-020-0381-5. Epub 2020 Feb 14.
Klotho, an antiaging protein, has been shown to play a protective role in renal tubular epithelial-mesenchymal transition (EMT) during the development of diabetic kidney disease (DKD). Long noncoding RNAs (lncRNAs) participate in the progression of EMT in many diseases. However, the effect of Klotho on lncRNAs during the development of DKD is still unknown. In this study, we found that Klotho overexpression in high-fat diet (HFD)- and streptozotocin (STZ)-induced DKD mice significantly inhibited the expression of lncRNA nuclear-enriched abundant transcript 1 (Neat1). We demonstrated that NEAT1 was significantly upregulated in both bovine serum albumin (BSA)-stimulated HK2 cells and mice with HFD- and STZ-induced diabetes. In addition, we observed that Klotho displays colocalization with NEAT1. Furthermore, overexpression of Klotho can inhibit the high expression of NEAT1 in BSA-stimulated HK2 cells, while silencing Klotho can further upregulate the expression of NEAT1. Silencing NEAT1 in HK2 cells resulted in inhibition of the EMT-related markers alpha smooth muscle actin (α-SMA) and vimentin (VIM) and the renal fibrosis-related markers transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF). The effect of NEAT1 on DKD was partly mediated by regulation of the ERK1/2 signaling pathway. Finally, we found that silencing NEAT1 can reverse the activation of EMT and fibrosis caused by Klotho silencing in a manner dependent on the ERK1/2 signaling pathway. These findings reveal a new regulatory pathway by which Klotho regulates ERK1/2 signaling via NEAT1 to protect against EMT and renal fibrosis, suggesting that NEAT1 is a potential therapeutic target for DKD.
Klotho 是一种抗衰老蛋白，已被证明在糖尿病肾病 (DKD) 的发展过程中在肾小管上皮-间充质转化 (EMT) 中发挥保护作用。长链非编码 RNA (lncRNA) 在许多疾病的 EMT 进展中发挥作用。然而，Klotho 在 DKD 发展过程中对 lncRNA 的影响尚不清楚。在这项研究中，我们发现高脂肪饮食 (HFD) 和链脲佐菌素 (STZ) 诱导的 DKD 小鼠中 Klotho 的过表达显着抑制了 lncRNA 核富集丰富转录物 1 (Neat1) 的表达。我们证明了在牛血清白蛋白 (BSA) 刺激的 HK2 细胞和 HFD 和 STZ 诱导的糖尿病小鼠中，Neat1 显着上调。此外，我们观察到 Klotho 与 Neat1 共定位。此外，Klotho 的过表达可以抑制 BSA 刺激的 HK2 细胞中 NEAT1 的高表达，而沉默 Klotho 可以进一步上调 NEAT1 的表达。HK2 细胞中 NEAT1 的沉默导致 EMT 相关标志物 α 平滑肌肌动蛋白 (α-SMA) 和波形蛋白 (VIM) 以及肾纤维化相关标志物转化生长因子-β1 (TGF-β1) 和结缔组织生长因子 (CTGF) 的表达受到抑制。NEAT1 对 DKD 的影响部分是通过调节 ERK1/2 信号通路介导的。最后，我们发现沉默 NEAT1 可以通过依赖于 ERK1/2 信号通路的方式逆转由 Klotho 沉默引起的 EMT 和纤维化的激活。这些发现揭示了 Klotho 通过 NEAT1 调节 ERK1/2 信号以防止 EMT 和肾纤维化的新调节途径，表明 NEAT1 是 DKD 的潜在治疗靶点。
