Protection of MES23.5 dopaminergic cells by obestatin is mediated by proliferative rather than anti-apoptotic action.
Obestatin is an endogenous peptide sharing a precursor with ghrelin. This study aims to investigate whether and how obestatin protects MES23.5 dopaminergic cells against 1-methyl-4-phenylpyridinium (MPP(+))-induced neurotoxicity. MES23.5 cells were pretreated with obestatin (10(-13)-10(-6) mol/L) for 20 min prior to incubation with 200 μmol/L MPP(+) for 12 or 24 h, or treated with obestatin alone (10(-13) to 10(-6) mol/L) for 0, 6, 12, and 24 h. The methyl thiazolyl tetrazolium (MTT) assay was used to measure cell viability. Flow cytometry was used to measure the caspase-3 activity and the mitochondrial transmembrane potential. Proliferating cell nuclear antigen (PCNA) protein levels were determined by Western blotting. Obestatin (10(-13) to 10(-7) mol/L) pretreatment blocked or even reversed the MPP(+)-induced reduction of viability in MES23.5 cells, but had no effect on MPP(+)-induced mitochondrial transmembrane potential collapse and caspase-3 activation. When applied alone, obestatin increased viability. Elevated PCNA levels occurred with 10(-7), 10(-9), 10(-11) and 10(-13) mol/L obestatin treatment for 12 h. The results suggest that the protective effects of obestatin against MPP(+) in MES23.5 cells are due to its proliferation-promoting rather than anti-apoptotic effects.
Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, 266071, China.
Xiao-Li
XL
Shen
Feng-Ju
FJ
Jia
Ning
N
Song
Jun-Xia
JX
Xie
Hong
H
Jiang
D015655:1-Methyl-4-phenylpyridinium / Q000633:toxicity; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D059290:Dopaminergic Neurons / Q000187:drug effects*; D054439:Ghrelin / Q000627:therapeutic use*; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D051381:Rats
D054439:Ghrelin; D018696:Neuroprotective Agents; D015655:1-Methyl-4-phenylpyridinium