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...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.展开更多
Dopamine and its receptors have been widely studied in the neurological conditions and in the retina. In this study, we evaluated the possible role of dopamine in rhegmatogenous retinal detachment(RRD) by comparing th...Dopamine and its receptors have been widely studied in the neurological conditions and in the retina. In this study, we evaluated the possible role of dopamine in rhegmatogenous retinal detachment(RRD) by comparing the amount of 3,4-dihydroxyphenylacetic acid(DOPAC), a surrogate index of retinal dopamin levels, in the vitreous sample of patients affected by RRD with those affected by macular pucker and vitre ous hemorrhage. Our results showed that significantly higher levels of DOPAC were found in the vitreou sample of patients affected by RRD compared with those affected by vitreous hemorrhage and macula pucker(P = 0.002). Specifically, no trace of the substance was found in vitreous hemorrhage and macula pucker samples. A slightly significant positive correlation was found among DOPAC and post-operativ best corrected visual acuity(r = 0.470, P = 0.049). No correlation was found between DOPAC and the day elapsed between diagnosis and surgery(P = 0.317). For the first time our findings suggest that DOPAC i released in RRD, but not in other retinal diseases such as vitreous hemorrhage and macular pucker. More over, we showed a correlation between visual acuity outcome and the amount of DOPAC in the vitreous This might have a potential, although still unknown, implication in the pathogenesis of the disease and/o in the associated photoreceptors loss. This study was approved by the Ethics Committee of Rome Tor Ver gata University Hospital(R.S.92.10) on September 24, 2010.展开更多
基金supported by grants from the National Basic Research Development Program(973 Program)of China(2012CB5267032011CB504102)+4 种基金the National Natural Science Foundation of China(81171207)the Ministry of Education of China(20103706110002)the Municipal Science and Technology Bureau of Qingdao(12-1-4-2-(19)-jch)Chinathe Program for Scientific Research Innovation Team in Colleges and Universities of Shandong ProvinceChina
文摘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.
文摘Dopamine and its receptors have been widely studied in the neurological conditions and in the retina. In this study, we evaluated the possible role of dopamine in rhegmatogenous retinal detachment(RRD) by comparing the amount of 3,4-dihydroxyphenylacetic acid(DOPAC), a surrogate index of retinal dopamin levels, in the vitreous sample of patients affected by RRD with those affected by macular pucker and vitre ous hemorrhage. Our results showed that significantly higher levels of DOPAC were found in the vitreou sample of patients affected by RRD compared with those affected by vitreous hemorrhage and macula pucker(P = 0.002). Specifically, no trace of the substance was found in vitreous hemorrhage and macula pucker samples. A slightly significant positive correlation was found among DOPAC and post-operativ best corrected visual acuity(r = 0.470, P = 0.049). No correlation was found between DOPAC and the day elapsed between diagnosis and surgery(P = 0.317). For the first time our findings suggest that DOPAC i released in RRD, but not in other retinal diseases such as vitreous hemorrhage and macular pucker. More over, we showed a correlation between visual acuity outcome and the amount of DOPAC in the vitreous This might have a potential, although still unknown, implication in the pathogenesis of the disease and/o in the associated photoreceptors loss. This study was approved by the Ethics Committee of Rome Tor Ver gata University Hospital(R.S.92.10) on September 24, 2010.
