Department of Laboratory Medicine, The People's Hospital of Gaozhou, Maoming, 525200, China.
Stem Cell Res Ther. 2022 Jul 28;13(1):373. doi: 10.1186/s13287-022-03071-z.
Renal tubular epithelial-myofibroblast transdifferentiation (EMT) plays a key role in the regulation of renal fibrosis. Exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs) play a crucial role in alleviating renal fibrosis and injury. Additionally, hucMSC-derived exosomes contain numerous microRNAs (miRNAs). However, it is unclear whether mesenchymal stem cells can regulate the transforming growth factor (TGF)-β1-induced EMT of human renal tubular epithelial cells (RTECs) through exosomal miRNAs.
HK-2, a human RTEC line, was co-treated with TGF-β1 and hucMSC-derived exosomes. Additionally, TGF-β1-treated HK-2 cells were transfected with a miR-335-5p mimic and disintegrin and metalloproteinase domain-containing protein 19 (ADAM19)-overexpression plasmid. miR-335-5p expression and ADAM19 protein and inflammation levels were measured via quantitative reverse transcription polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assays, respectively.
TGF-β1 treatment changed the shape of HK-2 cells from a cobblestone morphology to a long spindle shape, accompanied by an increase in interleukin (IL)-6, tumor necrosis factor-α, IL-1β, collagen I, collagen III, α-smooth muscle actin, vimentin, and N-cadherin protein levels, whereas E-cadherin protein levels were reduced in these HK-2 cells, suggesting that TGF-β1 treatment induced the inflammation and EMT of HK-2 cells. HucMSC-exosomes improved the inflammation and EMT phenotype of TGF-β1-induced HK-2 cells by transferring miR-335-5p. miR-335-5p was found to bind the ADAM19 3'-untranslated region to reduce ADAM19 protein levels. Additionally, miR-335-5p improved the inflammation and EMT phenotype of HK-2 cells by reducing ADAM19 protein levels with TGF-β1 induction.
HucMSC-derived exosomal miR-335-5p attenuates the inflammation and EMT of HK-2 cells by reducing ADAM19 protein levels upon TGF-β1 induction. This study provides a potential therapeutic strategy and identifies targets for clinically treating renal fibrosis.
肾小管上皮-肌成纤维细胞转分化（EMT）在调节肾纤维化中起着关键作用。人脐带间充质干细胞（hucMSC）衍生的外泌体在缓解肾纤维化和损伤方面起着至关重要的作用。此外，hucMSC 衍生的外泌体含有多种 microRNAs（miRNAs）。然而，尚不清楚间充质干细胞是否可以通过外泌体 miRNAs 调节转化生长因子（TGF）-β1 诱导的人肾小管上皮细胞（RTEC）的 EMT。
将 TGF-β1 和 hucMSC 衍生的外泌体共同处理 HK-2，一种人 RTEC 系。此外，用 miR-335-5p 模拟物和去整合素金属蛋白酶结构域蛋白 19（ADAM19）过表达质粒转染 TGF-β1 处理的 HK-2 细胞。通过定量逆转录聚合酶链反应、western blot 和酶联免疫吸附测定分别测量 miR-335-5p 的表达和 ADAM19 蛋白和炎症水平。
TGF-β1 处理使 HK-2 细胞的形状从鹅卵石形态变为长梭形，同时细胞培养液中白细胞介素（IL）-6、肿瘤坏死因子-α、IL-1β、胶原 I、胶原 III、α-平滑肌肌动蛋白、波形蛋白和 N-钙黏蛋白蛋白水平升高，而 E-钙黏蛋白蛋白水平降低，表明 TGF-β1 处理诱导了 HK-2 细胞的炎症和 EMT。hucMSC 外泌体通过转移 miR-335-5p 改善了 TGF-β1 诱导的 HK-2 细胞的炎症和 EMT 表型。发现 miR-335-5p 结合 ADAM19 3'-非翻译区以降低 ADAM19 蛋白水平。此外，miR-335-5p 通过降低 TGF-β1 诱导的 ADAM19 蛋白水平改善了 HK-2 细胞的炎症和 EMT 表型。
hucMSC 衍生的外泌体 miR-335-5p 通过降低 TGF-β1 诱导的 ADAM19 蛋白水平来减轻 HK-2 细胞的炎症和 EMT。本研究为临床上治疗肾纤维化提供了一种潜在的治疗策略，并确定了治疗靶点。
