Curcumin,an active ingredient of dietary spice used in curry,has been shown to exhibit anti-oxidant,anti-inflammatory and anti-proliferative properties.Using EB directed differentiation protocol of H-9 human em-bryoni...Curcumin,an active ingredient of dietary spice used in curry,has been shown to exhibit anti-oxidant,anti-inflammatory and anti-proliferative properties.Using EB directed differentiation protocol of H-9 human em-bryonic stem(ES)cells;we evaluated the effect of cur-cumin(0-20μmol/L)in enhancing such differentiation.Our results using real time PCR,western blotting and immunostaining demonstrated that curcumin signifi-cantly increased the gene expression and protein levels of cardiac specific transcription factor NKx2.5,cardiac troponin I,myosin heavy chain,and endothelial nitric oxide synthase during ES cell differentiation.Further-more,an NO donor enhanced the curcumin-mediated induction of NKx2.5 and other cardiac specific proteins.Incubation of cells with curcumin led to a dose depend-ent increase in intracellular nitrite to the same extent as giving an authentic NO donor.Functional assay for second messenger(s)cyclic AMP(cAMP)and cyclic GMP(cGMP)revealed that continuous presence of cur-cumin in differentiated cells induced a decrease in the baseline levels of cAMP but it significantly elevated baseline contents of cGMP.Curcumin addition to a cell free assay significantly suppressed cAMP and cGMP degradation in the extracts while long term treatment of intact cells with curcumin increased the rates of cAMP and cGMP degradation suggesting that this might be due to direct suppression of some cyclic nucleo-tide-degrading enzyme(phosphodiesterase)by curcu-min.These studies demonstrate that polyphenol curcu-min may be involved in differentiation of ES cells partly due to manipulation of nitric oxide signaling.展开更多
基金supported in part by grants from NIH grant(No.RO1GM0776695)the Welch Foundation and the University of Texas.
文摘Curcumin,an active ingredient of dietary spice used in curry,has been shown to exhibit anti-oxidant,anti-inflammatory and anti-proliferative properties.Using EB directed differentiation protocol of H-9 human em-bryonic stem(ES)cells;we evaluated the effect of cur-cumin(0-20μmol/L)in enhancing such differentiation.Our results using real time PCR,western blotting and immunostaining demonstrated that curcumin signifi-cantly increased the gene expression and protein levels of cardiac specific transcription factor NKx2.5,cardiac troponin I,myosin heavy chain,and endothelial nitric oxide synthase during ES cell differentiation.Further-more,an NO donor enhanced the curcumin-mediated induction of NKx2.5 and other cardiac specific proteins.Incubation of cells with curcumin led to a dose depend-ent increase in intracellular nitrite to the same extent as giving an authentic NO donor.Functional assay for second messenger(s)cyclic AMP(cAMP)and cyclic GMP(cGMP)revealed that continuous presence of cur-cumin in differentiated cells induced a decrease in the baseline levels of cAMP but it significantly elevated baseline contents of cGMP.Curcumin addition to a cell free assay significantly suppressed cAMP and cGMP degradation in the extracts while long term treatment of intact cells with curcumin increased the rates of cAMP and cGMP degradation suggesting that this might be due to direct suppression of some cyclic nucleo-tide-degrading enzyme(phosphodiesterase)by curcu-min.These studies demonstrate that polyphenol curcu-min may be involved in differentiation of ES cells partly due to manipulation of nitric oxide signaling.
