Role of ATP-dependent K channels in the effects of erythropoietin in renal ischaemia injury

• Published in: Indian journal of medical research (New Delhi, India : 1994) India : 1994), 2015-06, Vol.141 (6), p.807-815
• Main Authors: Yilmaz, Tonguc Utku, Yazihan, Nuray, Dalgic, Aydın, Kaya, Ezgi Ermis, Salman, Bulent, Kocak, Mehtap, Akcil, Ethem
• Format: Article
• Language: English
• Subjects: Adaptation; Adenosine triphosphate; Apoptosis; Apoptosis - drug effects; ATP (Adenosine triphosphate); Cell culture; Cell growth; Cell Line; Cell Proliferation - drug effects; Diazoxide - administration & dosage; Erythropoietin; Erythropoietin - administration & dosage; Gene expression; Gene Expression Regulation; Health aspects; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit - biosynthesis; KATP Channels - genetics; Kidney - drug effects; Kidney - injuries; Kidney diseases; Kidney Diseases - drug therapy; Kidney Diseases - genetics; Kidney Diseases - pathology; Kidney Tubules - drug effects; Kidney Tubules - pathology; Kidneys; Kinases; Original; Peptides; Physiological aspects; Potassium; Potassium channels; Proteins; R&D; Reperfusion Injury - drug therapy; Reperfusion Injury - genetics; Research & development; Rodents; Roles
• ISSN: 0971-5916; 0975-9174
• DOI: 10.4103/0971-5916.160713

Erythropoietin (EPO) has cytoprotective and anti-apoptotic effects in pathological conditions, including hypoxia and ischaemia-reperfusion injury. One of the targets to protect against injury is ATP-dependent potassium (KATP ) channels. These channels could be involved in EPO induced ischaemic preconditoning like a protective effect. We evaluated the cell cytoprotective effects of EPO in relation to KATP channel activation in the renal tubular cell culture model under hypoxic/normoxic conditions. Dose and time dependent effects of EPO, KATP channel blocker glibenclamide and KATP channel opener diazoxide on cellular proliferation were evaluated by colorimetric assay MTT [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide] under normoxic and hypoxic conditions in human renal proximal tubular cell line (CRL-2830). Evaluation of the dose and time dependent effects of EPO, glibenclamide and diazoxide on apoptosis was done by caspase-3 activity levels. Hypoxia inducible factor-1 alpha (HIF-1 α) mRNA levels were measured by semi-quantative reverse transcription polymerase chain reaction (RT)-PCR. Kir 6.1 protein expresion was evalutaed by Western blot. Glibenclamide treatment decreased the number of living cells in a time and dose dependent manner, whereas EPO and diazoxide treatments increased. Glibenclamide (100 μM) treatment significantly blocked the anti-apoptotic effects of EPO (10 IU/ml) under both normoxic and hypoxic conditions. EPO (10 IU/ml) and diazoxide (100 μM) treatments significantly increased (p