Kruppel-like factor 15 is a key suppressor of podocyte fibrosis under rotational force-driven pressure

Abstract

Kruppel-like factor 15 (KLF15) is a well-known transcription factor associated with podocyte injury and fibrosis. Recently, hypertensive nephropathy was discovered to be closely related to podocyte injury and fibrosis. However, methods to stimulate hypertension in vitro are lacking. Here, we constructed an in vitro model mimicking hypertension using a rotational force device to identify the role of KLF15 in fibrosis due to mechanically induced hypertensive injury. First, we found that KLF15 expression was decreased in patients with hypertensive nephropathy. Then, an in vitro study of hypertension due to rotational force was conducted, and an increase in fibrosis markers and decrease in KLF15 levels were determined after application of 4 mmHg pressure in primary cultured human podocytes. KLF15 and tight junction protein levels increased with retinoic acid treatment. siRNA-mediated inhibition of KLF15 exacerbated pressure-induced fibrosis injury, and KLF15 expression after treatment with angiotensin II was similar to that observed after treatment with the blood pressure modeling device. Furthermore, the reduced KLF15 levels after mechanical pressure application were restored after the administration of an antihypertensive drug. KLF15 expression was also low in vivo. We confirmed the protective role of KLF15 in fibrosis using a mechanically induced in vitro model of hypertensive injury.