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

Yilmaz TU, Yazihan N, Dalgic A, Kaya EE, Salman B, Kocak M, Akcil E - Indian J. Med. Res. (2015)

Bottom Line: Erythropoietin (EPO) has cytoprotective and anti-apoptotic effects in pathological conditions, including hypoxia and ischaemia-reperfusion injury.EPO (10 IU/ml) and diazoxide (100 μM) treatments significantly increased (p <0.01) whereas glibenclamide decreased ( p<0.05) HIF-1 α mRNA expression.Glibenclamide significantly ( p<0.01) decreased EPO induced HIF-1 α mRNA expression when compared with the EPO alone group.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine, Department of General Surgery, Kocaeli University, Kocaeli, Turkey.

ABSTRACT

Background & objectives: 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.

Methods: 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.

Results: 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 <0.01) whereas glibenclamide decreased ( p<0.05) HIF-1 α mRNA expression. Glibenclamide significantly ( p<0.01) decreased EPO induced HIF-1 α mRNA expression when compared with the EPO alone group.

Interpretation & conclusions: Our results showed that the cell proliferative, cytoprotective and anti-apoptotic effects of EPO were associated with KATP channels in the renal tubular cell culture model under hypoxic/normal conditions.

No MeSH data available.


Related in: MedlinePlus

Effects of glibenclamide (Gli 10,100 μM) and diazoxide (Dia 10,100 μM) treatment on cell proliferation index in normoxia and hypoxia at 2, 24 and 48 h by the MTT assay. Data are presented as mean ± SE (n=40 observations).
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Figure 2: Effects of glibenclamide (Gli 10,100 μM) and diazoxide (Dia 10,100 μM) treatment on cell proliferation index in normoxia and hypoxia at 2, 24 and 48 h by the MTT assay. Data are presented as mean ± SE (n=40 observations).

Mentions: The Gli treatment decreased the living cell number in a time- and dose-dependent manner. The number of cells in groups Gli 10 and 100 significantly decreased at the 48th h when compared with the control group (P<0.001). While the number of cells in the control group increased under normoxia, the number of cells decreased in groups treated with Gli. On the other hand, Dia treatment increased the number of cells in a time- and dose-dependent manner. The number of cells in Dia 100 were significantly increased at the 48th h when compared with the control group (P<0.001). Hypoxia decreased cell proliferation to 89, 85, and 69 per cent of the control group at 2, 24 (P<0.05), and 48 (P<0.01) h, respectively. In hypoxic conditions, the number of cells decreased significantly in group Gli 100 when compared with the control group (P<0.001). However, the number of cells treated with Dia significantly increased in a time-dependent manner under hypoxic conditions when compared with the control group (P<0.001) (Fig. 2). Glibenclamid also decreased the proliferative effect of EPO in both normoxic (P<0.001) and hypoxic (P<0.05) conditions. There were significant differences between the EPO 10 and EPO 10+ Gli 100 groups at 48 h (Fig. 2).


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

Yilmaz TU, Yazihan N, Dalgic A, Kaya EE, Salman B, Kocak M, Akcil E - Indian J. Med. Res. (2015)

Effects of glibenclamide (Gli 10,100 μM) and diazoxide (Dia 10,100 μM) treatment on cell proliferation index in normoxia and hypoxia at 2, 24 and 48 h by the MTT assay. Data are presented as mean ± SE (n=40 observations).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525406&req=5

Figure 2: Effects of glibenclamide (Gli 10,100 μM) and diazoxide (Dia 10,100 μM) treatment on cell proliferation index in normoxia and hypoxia at 2, 24 and 48 h by the MTT assay. Data are presented as mean ± SE (n=40 observations).
Mentions: The Gli treatment decreased the living cell number in a time- and dose-dependent manner. The number of cells in groups Gli 10 and 100 significantly decreased at the 48th h when compared with the control group (P<0.001). While the number of cells in the control group increased under normoxia, the number of cells decreased in groups treated with Gli. On the other hand, Dia treatment increased the number of cells in a time- and dose-dependent manner. The number of cells in Dia 100 were significantly increased at the 48th h when compared with the control group (P<0.001). Hypoxia decreased cell proliferation to 89, 85, and 69 per cent of the control group at 2, 24 (P<0.05), and 48 (P<0.01) h, respectively. In hypoxic conditions, the number of cells decreased significantly in group Gli 100 when compared with the control group (P<0.001). However, the number of cells treated with Dia significantly increased in a time-dependent manner under hypoxic conditions when compared with the control group (P<0.001) (Fig. 2). Glibenclamid also decreased the proliferative effect of EPO in both normoxic (P<0.001) and hypoxic (P<0.05) conditions. There were significant differences between the EPO 10 and EPO 10+ Gli 100 groups at 48 h (Fig. 2).

Bottom Line: Erythropoietin (EPO) has cytoprotective and anti-apoptotic effects in pathological conditions, including hypoxia and ischaemia-reperfusion injury.EPO (10 IU/ml) and diazoxide (100 μM) treatments significantly increased (p <0.01) whereas glibenclamide decreased ( p<0.05) HIF-1 α mRNA expression.Glibenclamide significantly ( p<0.01) decreased EPO induced HIF-1 α mRNA expression when compared with the EPO alone group.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine, Department of General Surgery, Kocaeli University, Kocaeli, Turkey.

ABSTRACT

Background & objectives: 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.

Methods: 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.

Results: 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 <0.01) whereas glibenclamide decreased ( p<0.05) HIF-1 α mRNA expression. Glibenclamide significantly ( p<0.01) decreased EPO induced HIF-1 α mRNA expression when compared with the EPO alone group.

Interpretation & conclusions: Our results showed that the cell proliferative, cytoprotective and anti-apoptotic effects of EPO were associated with KATP channels in the renal tubular cell culture model under hypoxic/normal conditions.

No MeSH data available.


Related in: MedlinePlus