Pressure and stretch differentially affect proliferation of renal proximal tubular cells

Abstract

Renal obstruction is frequently found in adults and children. Mechanical stimuli, including pressure and stretch in the obstructed kidney, contribute to damage; animal models of obstruction are characterized by increased cellular proliferation. We were interested in the direct effects of pressure and stretch on renal tubular cell proliferation. Human HKC‐8 or rat NRK‐52E proximal tubule cells were subjected to either pressure [0, 60 or 90 mmHg] or static stretch [0 or 20%] for 24 or 48 h. Cell proliferation was measured by cell counting, cell cycle analyzed by flow cytometry, and PCNA and Skp2 expression were determined by qPCR or western blot. Blood gases were determined in an iSTAT system. Proliferation was also assessed in vivo after 24 h of ureteral obstruction. There was a significant increase in HKC‐8 cell number after 48 h of exposure to either 60 or 90 mmHg pressure. Western blot and qPCR confirmed increased expression of PCNA and Skp2 in pressurized cells. Cell cycle measurements demonstrated an increase in HKC‐8 in S phase. Mechanical stretching increased PCNA protein expression in HKC‐8 cells after 48 h while no effect was observed on Skp2 and cell cycle measurements. Increased PCNA expression was found at 24 h after ureteral obstruction. We demonstrate direct transduction of pressure into a proliferative response in HKC‐8 and NRK‐52E cells, measured by cell number, PCNA and Skp2 expression and increase in cells in S phase, whereas stretch had a less robust effect on proliferation.

Effects of Chicory on Serum Uric Acid, Renal Function, and GLUT9 Expression in Hyperuricaemic Rats with Renal Injury and In Vitro Verification with Cells

“…HKC cells are a group of cells that are mostly composed of normal human proximal tubular epithelial cells. HKC cells are widely used in pharmacological and toxicological experiments [31, 32]. GLUT9 is mainly distributed on the tubular apical membrane of the renal tubule.…”

Effects of hydroxyethyl starch 130/0.4 on the kidney tissue of rats with ureteral obstruction

“…A significant increase in the number of apoptotic and proliferative tubular cells in inducible-NO synthase gene knockout mice, following unilateral obstructive nephropathy, was reportedly an indicative of the anti-apoptotic properties of NO, as demonstrated by Miyajima et al 27 Even though NO has complex effects on renal oxidative status, it exerts important anti-apoptotic protective effects in UUO. 28 Felsen et al 29 subjected cultured tubular epithelial cells to mechanical stretch as, an in vitro replication of UUO-induced tubular cellular stress to study the role of NO in apoptosis during UUO.…”

Overexpression of pressure-responsive miRNA-5703 inhibits pressure-induced growth and metastasis of liver cancer

“…The 2-dimensional (2D) pressure loading system was designed and manufactured by our research group, and the protocol can be found in our previous papers [14,29,30]. The Flexcell-5000 Compression System (Flexcell International Corp, Burlington, NC, US) was used to exert pressure on the 3D cultured cells.…”