Premium
Blockade of 20‐HETE synthesis confers resistance to stress‐induced apoptosis in renal tubular cells
Author(s) -
Alexander Larry D.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.616.5
Subject(s) - apoptosis , arachidonic acid , chemistry , cytochrome c , western blot , programmed cell death , kinase , hydroxyeicosatetraenoic acid , microbiology and biotechnology , biochemistry , biology , enzyme , gene
Changes of the levels of 20‐Hydroxyeicosatetraenoic acid (20‐HETE), an ω‐hydroxylation product of arachidonic acid catalyzed by cytochrome P450 4A, have been recently reported to mediate program‐cell death associated with renal ischemia‐reperfusion (IR) injury. In this study, we evaluated the effects of 20‐HETE and a 20‐HETE synthesis inhibitor N‐hydroxy‐N′‐(4‐butyl‐2 methylphenyl) formamidine (HET0016), on stretch‐mediated cell death in renal epithelial (HK‐2) cells. Stretch‐induced apoptosis was detected by measuring histone‐associated DNA fragments using ELISA (Enzyme‐Linked Immunosorbent Assay) and caspase activity assays. A 20‐HETE competitive in vitro ELISA kit was used for the determination of 20‐HETE levels in biological samples. 20‐HETE protein levels were analyzed using Western blot. Here we report that HK‐2 cells express cytochrome P450 (CYP) 4A protein and produce 20‐HETE when stimulated with cyclic stretch. Exogenous application of 20‐HETE increased, whereas inhibition of 20‐HETE production with HET0016 attenuated 20‐HETE‐ and cyclic stretch‐induced apoptosis. Our results also show that 20‐HETE and cyclic stretch causes time‐dependent activation of c‐Jun N‐terminal kinase (JNK) activity, which was significantly attenuated by HET0016. In addition, the JNK inhibitor SP600125 significantly attenuated cyclic stretch‐and 20‐HETE‐induced apoptosis, whereas the extracellular signal‐regulated kinase1/2 (ERK1/2) and p38MAPK inhibitors PD98590 and SB23580, respectively, were without affect. These data provide the first evidence that 20‐HETE is a potent and direct inducer of apoptosis in renal proximal tubule cells. More importantly, these observations demonstrate a critical upstream role of JNK in cyclic stretch‐induced apoptosis dependent of ω‐hydroxylation of arachidonic acid. Support or Funding Information This work was supported by a Scholarly Activity and Research Program (SARP) grant to Dr. Larry D. Alexander This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .