In normal physiological conditions,reactive oxygen and nitrogen species are used as important signaling molecules in the cell.However,in excess it causes the disruption of cell resulting in their death.Oxidative stres...In normal physiological conditions,reactive oxygen and nitrogen species are used as important signaling molecules in the cell.However,in excess it causes the disruption of cell resulting in their death.Oxidative stress causes influx in intracellular calcium levels leading to higher concentrations of calcium in the cell.This accelerated calcium affects both the mitochondria and nuclei leading to excitotoxicity in neurons.Intracellular calcium levels are controlled by voltage dependent calcium channels located in the plasma membrane,calcium stores like endoplasmic/sarcoplasmic reticulum and majorly by calcium binding proteins.Our study was aimed at analyzing the gene expression of major calcium binding proteins namely calcineurin,calmodulin,calreticulin,synaptotagamin and calsyntenin in stress induced PC 12 cells.Rotenone(1 mM),Peroxynitrite(10 mM),H_(2)O_(2)(100 mM)and High glucose(33 mM)were used to induce oxidative stress in PC12 cells.Results obtained from the study suggest that calcineurin,calmodulin and calsyntenin gene expression were enhanced compared to the control due to oxidative stress.However,synaptotagmin and calreticulin gene expression were down regulated.Further,Akt protein expression(stress marker)was enhanced in PC12 cells with all other stress inducers except in hyperglycemic condition.展开更多
Activator protein-1(AP-1)transcription factor is a key component of many signal transduction pathways involved in the regulation of cellular processes and controls rapid responses of mammalian cells when exposed to th...Activator protein-1(AP-1)transcription factor is a key component of many signal transduction pathways involved in the regulation of cellular processes and controls rapid responses of mammalian cells when exposed to the variety of stimulus.The phorbol 12-myristate 13-acetate and Forskolin(Fo)are well-known kinase activators/stimulators of Protein Kinase C(PKC)and Protein Kinase A(PKA)respectively.Importantly,these kinases are found to be present in transitional points of many cell signaling pathways,especially those involved in proliferation.The stimulating effect of PKC and PKA on the expression of AP-1 factors in MCF-7 breast cell proliferation is not well characterized.Hence,the role of PKC by PMA treatment and the role of PKA by using Fo in MCF-7 cells is investigated.Where,cells treated with PMA showed increased cell proliferation,while Fo had no effect,but inhibited the PMA induced proliferation.The RT-PCR results showed the PMA induced c-Jun,c-Fos and Fra-1 expressions compared to control and Fo.However,Fo in combination with PMA,inhibit the PMA induced above mRNA expressions where Fo alone has no effect.Western blot studies validated the c-Jun expressions in PMA treated MCF-7 cells.Further,PMA increases the mRNA expression of Cyclin-E1,Cyclin-D1,and CDK-4,whereas Fo decreases their expressions.Thus,mitogenic effect of PMA and inhibitory action of Fo on MCF-7 cells is probably enhanced via activation of AP-1 factors and concomitant action of cell cycle regulators in the downstream singling cascade.展开更多
基金DST-SERB,New Delhi for providing financial Grant(SB/EMEQ-238/2013)to Dr.K.S.Devaraju.Aravind.P greatly acknowledges the University Research fellowship sanctioned by Karnatak University,Dharwad.
文摘In normal physiological conditions,reactive oxygen and nitrogen species are used as important signaling molecules in the cell.However,in excess it causes the disruption of cell resulting in their death.Oxidative stress causes influx in intracellular calcium levels leading to higher concentrations of calcium in the cell.This accelerated calcium affects both the mitochondria and nuclei leading to excitotoxicity in neurons.Intracellular calcium levels are controlled by voltage dependent calcium channels located in the plasma membrane,calcium stores like endoplasmic/sarcoplasmic reticulum and majorly by calcium binding proteins.Our study was aimed at analyzing the gene expression of major calcium binding proteins namely calcineurin,calmodulin,calreticulin,synaptotagamin and calsyntenin in stress induced PC 12 cells.Rotenone(1 mM),Peroxynitrite(10 mM),H_(2)O_(2)(100 mM)and High glucose(33 mM)were used to induce oxidative stress in PC12 cells.Results obtained from the study suggest that calcineurin,calmodulin and calsyntenin gene expression were enhanced compared to the control due to oxidative stress.However,synaptotagmin and calreticulin gene expression were down regulated.Further,Akt protein expression(stress marker)was enhanced in PC12 cells with all other stress inducers except in hyperglycemic condition.
基金Grants Commission(UGC),New Delhi for providing Major Research Project financial Grant(F.No.34-250/2008(SR))to SCS.
文摘Activator protein-1(AP-1)transcription factor is a key component of many signal transduction pathways involved in the regulation of cellular processes and controls rapid responses of mammalian cells when exposed to the variety of stimulus.The phorbol 12-myristate 13-acetate and Forskolin(Fo)are well-known kinase activators/stimulators of Protein Kinase C(PKC)and Protein Kinase A(PKA)respectively.Importantly,these kinases are found to be present in transitional points of many cell signaling pathways,especially those involved in proliferation.The stimulating effect of PKC and PKA on the expression of AP-1 factors in MCF-7 breast cell proliferation is not well characterized.Hence,the role of PKC by PMA treatment and the role of PKA by using Fo in MCF-7 cells is investigated.Where,cells treated with PMA showed increased cell proliferation,while Fo had no effect,but inhibited the PMA induced proliferation.The RT-PCR results showed the PMA induced c-Jun,c-Fos and Fra-1 expressions compared to control and Fo.However,Fo in combination with PMA,inhibit the PMA induced above mRNA expressions where Fo alone has no effect.Western blot studies validated the c-Jun expressions in PMA treated MCF-7 cells.Further,PMA increases the mRNA expression of Cyclin-E1,Cyclin-D1,and CDK-4,whereas Fo decreases their expressions.Thus,mitogenic effect of PMA and inhibitory action of Fo on MCF-7 cells is probably enhanced via activation of AP-1 factors and concomitant action of cell cycle regulators in the downstream singling cascade.
