RRC ID 56608
著者 Anusornvongchai T, Nangaku M, Jao TM, Wu CH, Ishimoto Y, Maekawa H, Tanaka T, Shimizu A, Yamamoto M, Suzuki N, Sassa R, Inagi R.
タイトル Palmitate deranges erythropoietin production via transcription factor ATF4 activation of unfolded protein response.
ジャーナル Kidney Int
Abstract Lipotoxicity plays an important role in the progression of chronic kidney damage via various mechanisms, such as endoplasmic reticulum stress. Several studies proposed renal lipotoxicity in glomerular and tubular cells but the effect of lipid on renal erythropoietin (EPO)-producing (REP) cells in the interstitium has not been elucidated. Since renal anemia is caused by derangement of EPO production in REP cells, we evaluated the effect of palmitate, a representative long-chain saturated fatty acid, on EPO production and the endoplasmic reticulum stress pathway. EPO production was suppressed by palmitate (palmitate-conjugated bovine serum albumin [BSA]) or a high palmitate diet, but not oleic acid-conjugated BSA or a high oleic acid diet, especially under cobalt-induced pseudo-hypoxia both in vitro and in vivo. Importantly, suppression of EPO production was not induced by a decrease in transcription factor HIF activity, while it was significantly associated with endoplasmic reticulum stress, particularly transcription factor ATF4 activation, which suppresses 3'-enhancer activity of the EPO gene. ATF4 knockdown by siRNA significantly attenuated the suppressive effect of palmitate on EPO production. Studies utilizing inherited super-anemic mice (ISAM) mated with EPO-Cre mice (ISAM-REC mice) for lineage-labeling of REP cells showed that ATF4 activation by palmitate suppressed EPO production in REP cells. Laser capture microdissection confirmed ATF4 activation in the interstitial area of ISAM-REC mice treated with palmitate-conjugated BSA. Thus, endoplasmic reticulum stress induced by palmitate suppressed EPO expression by REP cells in a manner independent of HIF activation. The link between endoplasmic reticulum stress, dyslipidemia, and hypoxia may contribute to development and progression of anemia in CKD.
巻・号 94(3)
ページ 536-550
公開日 2018-9-1
DOI 10.1016/j.kint.2018.03.011
PII S0085-2538(18)30250-3
PMID 29887316
MeSH Activating Transcription Factor 4 / genetics Activating Transcription Factor 4 / metabolism* Anemia / blood Anemia / etiology Anemia / pathology* Animals Basic Helix-Loop-Helix Transcription Factors / metabolism Diet, High-Fat / adverse effects Disease Models, Animal Endoplasmic Reticulum Stress Erythropoietin / blood Erythropoietin / genetics Erythropoietin / metabolism* Gene Knockdown Techniques Hep G2 Cells Humans Kidney / metabolism* Laser Capture Microdissection Male Mice Mice, Inbred C57BL Palmitates / metabolism* RNA, Small Interfering / metabolism Renal Insufficiency, Chronic / blood Renal Insufficiency, Chronic / etiology Renal Insufficiency, Chronic / pathology Unfolded Protein Response
IF 8.306
引用数 9
リソース情報
ヒト・動物細胞 Hep G2(RCB1886)