Fatty acids bound to albumin induce prostaglandin E2 production in human renal proximal tubular epithelial cell line HK-2

• Published in: Biochemical and biophysical research communications 2020-09, Vol.530 (1), p.273-277
• Main Authors: Nakatsuji, Minori, Urakami-Takebayashi, Yumiko, Miyadokoro, Sae, Ikeda, Toyoaki, Takehara, Ikki, Sun, Hongxin, Motohashi, Hideyuki, Ohno, Yoshio, Nagai, Junya
• Format: Article
• Language: English
• Subjects: Albumin; Arachidonic acid; Fatty acids; Hypoxia inducible factor-1; Prostaglandin E2; Renal proximal tubular cells
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2020.07.033

Fatty acids bound to albumin have been reported to be involved in various responses in renal proximal tubular cells following albumin overload, leading to progression of tubulointerstitial damage in the kidneys. In addition, it has been reported that prostaglandin E2 (PGE2) plays an important role in nephrotoxicity. The aim of this study was to examine whether albumin-bound fatty acids induce PGE2 production in human renal proximal tubular epithelial cell line HK-2. Fatty acid-bearing human serum albumin increased PGE2 release in the culture medium in concentration-dependent and time-dependent manners, but fatty acid-depleted albumin had no effect on PGE2 production. Next, we investigated the effect of arachidonic acid, a precursor of eicosanoids, on PGE2 production. Arachidonic acid with fatty acid-free albumin significantly enhanced the release of PGE2 into the medium in a concentration-dependent manner. Furthermore, we examined the effect of arachidonic acid on mRNA expression of hypoxia inducible factor-1α (HIF-1α). Arachidonic acid increased HIF-1α mRNA expression in a concentration-dependent manner. These findings suggest that fatty acids, at least in part arachidonic acid, bound to albumin increase PGE2 production and expression of HIF-1α mRNA and protein, possibly resulting in various cell responses induced by albumin overload. •Fatty acid-bearing albumin but not fatty acid-depleted albumin enhanced PGE2 production in HK-2 cells.•Arachidonic acid increased the release of PGE2 in HK-2 cells.•Arachidonic acid as well as fatty acid-bearing albumin increased the expression of mRNA and protein of HIF-1α.