Department of Nephrology, The First People's Hospital of Changzhou, Changzhou, China.
Department of Pathology, The Second People's Hospital of Changzhou, Changzhou, China.
Ren Fail. 2021 Dec;43(1):391-400. doi: 10.1080/0886022X.2021.1891098.
Cardiomyocyte hypertrophy has been reported as one of the important mechanisms for cardiovascular disease (CVD) in patients with chronic kidney disease (CKD). MiroRNA-21(miR-21) was determined to play an important role in myocardial hypertrophy. However, the role of microvesicles (MVs) containing miR-21 in CKD-related cardiomyocyte hypertrophy remains largely unexplored.
Renal tubular epithelial cells were stimulated by transforming growth factor (TGF-β1), and the conditioned medium was extracted by differential centrifugation. Renal tubular epithelial cells were labeled with Dil-C18 dye and the recipient cardiomyocytes were observed by fluorescence microscope. MiR-21 level in MVs was detected by qRT-PCR, and the length and diameter of cardiomyocytes were measured by microscope. BCA protein kit and ANP kit were used to detect the content of cell protein and the level of ANP. MiR-21 inhibitor was transfected into cardiomyocytes to observe the effect of miR-21 on myocardial hypertrophy.
TGF-β1 could induce donor renal tubular epithelial cells to produce MVs and delivered into cardiomyocytes, followed by the diameter, protein concentration and ANP content of cardiomyocytes significantly increased. Meanwhile, MiR-21 levels were markedly increased in MVs isolated from donor renal tubular epithelial cells and recipient cardiomyocytes. Pre-transfection of miR-21 inhibitors could inhibit MV-induced cardiomyocyte hypertrophy.
Tubular cells could secrete miR-21 by MVs and deliver it into recipient cardiomyocytes to induce cardiomyocyte hypertrophy. It might shed a new light on the mechanism and treatment of CKD-related cardiac dysfunction.
心肌细胞肥大已被报道为慢性肾脏病（CKD）患者心血管疾病（CVD）的重要机制之一。miRNA-21（miR-21）被确定在心肌肥大中发挥重要作用。然而，含 miR-21 的微小泡（MVs）在 CKD 相关心肌细胞肥大中的作用在很大程度上仍未得到探索。
用转化生长因子（TGF-β1）刺激肾小管上皮细胞，通过差速离心提取条件培养基。用 Dil-C18 染料标记肾小管上皮细胞，荧光显微镜观察受体心肌细胞。用 qRT-PCR 检测 MVs 中的 miR-21 水平，用显微镜测量心肌细胞的长度和直径。用 BCA 蛋白试剂盒和 ANP 试剂盒检测细胞蛋白含量和 ANP 水平。将 miR-21 抑制剂转染到心肌细胞中，观察 miR-21 对心肌肥大的影响。
TGF-β1 可诱导供体肾小管上皮细胞产生 MVs 并传递到心肌细胞，随后心肌细胞的直径、蛋白浓度和 ANP 含量明显增加。同时，供体肾小管上皮细胞和受体心肌细胞中分离的 MVs 中 miR-21 水平明显升高。转染前 miR-21 抑制剂可抑制 MV 诱导的心肌细胞肥大。
肾小管细胞可通过 MVs 分泌 miR-21 并将其传递到受体心肌细胞，从而诱导心肌细胞肥大。这可能为 CKD 相关心功能障碍的机制和治疗提供新的思路。
