OBJECTIVE Ascorbic acid(AA),commonly known as vitamin C,is a small molecular widely distributed in in food and traditional herbs.Recently,there are some literatures reported that high concentration AA could selectivel...OBJECTIVE Ascorbic acid(AA),commonly known as vitamin C,is a small molecular widely distributed in in food and traditional herbs.Recently,there are some literatures reported that high concentration AA could selectively kill the cancer cells but not the normal cells.This study was designed to explore the underlying mechanisms.METHODS Colorectal cancer line cells were cultured and treated with AA.The cytotoxic,intracellular ATP level,reactive oxygen species,calcium,were determined with commercial kits and fluorescent probes.RESULTS High concentration of AA induced cell death in HCT116 and HT29 colorectal cancer cells in concentration-and time-dependent manner.AA treat⁃ment induced ATP decrease,LDH release,cell swollen and loss of plasma membrane integrity.Pharmacological inhibi⁃tors for apoptosis,necroptosis,autophagy,pyroptosis and oncosis showed no effect on AA-induced cell death.Further⁃more,ROS level increase and intracellular calcium(Ca2+)accumulation were observed after AA treatment.ROS scavenger N-acetyl cysteine(NAC),intracellular calcium chelator BAPTA-AM and intracellular calcium inhibitor 2-aminoethoxy⁃diphenyl borate(2-APB)could attenuate the cell death induced by AA.NAC could attenuate both ROS increase and intracellular Ca2+accumulation induced by AA,while BAPTA-AM could only attenuate intracellular Ca2+accumulation.In addition,high concentration AA induced mitochondrial damage and mitochondrial ROS generation.CONCLUSION AA induces Ca2+-dependent programed necrosis mediated by ROS.Our study provided new insights into high concentration AA induced cell death in human colon cancer cells.展开更多
Cell death has been extensively evaluated for decades and it is well recognized that pharmacological interventions directed to inhibit cell death can prevent significant cell loss and can thus improve an organ�...Cell death has been extensively evaluated for decades and it is well recognized that pharmacological interventions directed to inhibit cell death can prevent significant cell loss and can thus improve an organ’s physiological function. For long, only apoptosis was considered as a sole form of programmed cell death. Recently necroptosis, a RIP1/RIP3-dependent programmed cell death, has been identified as an apoptotic backup cell death mechanism with necrotic morphology. The evidences of necroptosis and protective effects achieved by blocking necroptosis have been extensively reported in recent past. However, only a few studies reported the evidence of necroptosis and protective effects achieved by inhibiting necroptosis in liver related disease conditions. Although the number of necroptosis initiators is increasing; however, interestingly, it is still unclear that what actually triggers necroptosis in different liver diseases or if there is always a different necroptosis initiator in each specific disease condition followed by specific downstream signaling molecules. Understanding the precise mechanism of necroptosis as well as counteracting other cell death pathways in liver diseases could provide a useful insight towards achieving extensive therapeutic significance. By targeting necroptosis and/or other parallel death pathways, a significant cell loss and thus a decrement in an organ’s physiological function can be prevented.展开更多
Necroptosis is characterized by programmed necrotic cell death and autophagic activation and might be involved in the death process of dopaminergic neurons in Parkinson＇s disease. We hypothesized that necrostatin-1 c...Necroptosis is characterized by programmed necrotic cell death and autophagic activation and might be involved in the death process of dopaminergic neurons in Parkinson＇s disease. We hypothesized that necrostatin-1 could block necroptosis and give protection to dopaminergic neurons. There is likely to be crosstalk between necroptosis and other cell death pathways, such as apoptosis and autophagy. PC12 cells were pretreated with necroststin-1 1 hour before exposure to 6-hydroxydopamine. We examined cell viability, mitochondrial membrane potential and expression patterns of apoptotic and necroptotic death signaling proteins. The results showed that the autophagy/lysosomal pathway is involved in the 6-hydroxydopamine-induced death process of PC12 cells. Mitochondrial disability induced overactive autophagy, increased cathepsin B expression, and diminished Bcl-2 expression. Necrostatin-1 within a certain concentration range（5–30 μM） elevated the viability of PC12 cells, stabilized mitochondrial membrane potential, inhibited excessive autophagy, reduced the expression of LC3-II and cathepsin B, and increased Bcl-2 expression. These findings suggest that necrostatin-1 exerted a protective effect against injury on dopaminergic neurons. Necrostatin-1 interacts with the apoptosis signaling pathway during this process. This pathway could be a new neuroprotective and therapeutic target in Parkinson＇s disease.展开更多
基金Science and Technology Development Fund,Macao SAR(078/2016/A2)Research Fund of University of Macao(MYRG2016-00043-ICMS-QRCM)
文摘OBJECTIVE Ascorbic acid(AA),commonly known as vitamin C,is a small molecular widely distributed in in food and traditional herbs.Recently,there are some literatures reported that high concentration AA could selectively kill the cancer cells but not the normal cells.This study was designed to explore the underlying mechanisms.METHODS Colorectal cancer line cells were cultured and treated with AA.The cytotoxic,intracellular ATP level,reactive oxygen species,calcium,were determined with commercial kits and fluorescent probes.RESULTS High concentration of AA induced cell death in HCT116 and HT29 colorectal cancer cells in concentration-and time-dependent manner.AA treat⁃ment induced ATP decrease,LDH release,cell swollen and loss of plasma membrane integrity.Pharmacological inhibi⁃tors for apoptosis,necroptosis,autophagy,pyroptosis and oncosis showed no effect on AA-induced cell death.Further⁃more,ROS level increase and intracellular calcium(Ca2+)accumulation were observed after AA treatment.ROS scavenger N-acetyl cysteine(NAC),intracellular calcium chelator BAPTA-AM and intracellular calcium inhibitor 2-aminoethoxy⁃diphenyl borate(2-APB)could attenuate the cell death induced by AA.NAC could attenuate both ROS increase and intracellular Ca2+accumulation induced by AA,while BAPTA-AM could only attenuate intracellular Ca2+accumulation.In addition,high concentration AA induced mitochondrial damage and mitochondrial ROS generation.CONCLUSION AA induces Ca2+-dependent programed necrosis mediated by ROS.Our study provided new insights into high concentration AA induced cell death in human colon cancer cells.
基金Supported by A grant of the Korea Healthcare technology R and D Project,Ministry of Health and Welfare,South Korea,NO.A121185
文摘Cell death has been extensively evaluated for decades and it is well recognized that pharmacological interventions directed to inhibit cell death can prevent significant cell loss and can thus improve an organ’s physiological function. For long, only apoptosis was considered as a sole form of programmed cell death. Recently necroptosis, a RIP1/RIP3-dependent programmed cell death, has been identified as an apoptotic backup cell death mechanism with necrotic morphology. The evidences of necroptosis and protective effects achieved by blocking necroptosis have been extensively reported in recent past. However, only a few studies reported the evidence of necroptosis and protective effects achieved by inhibiting necroptosis in liver related disease conditions. Although the number of necroptosis initiators is increasing; however, interestingly, it is still unclear that what actually triggers necroptosis in different liver diseases or if there is always a different necroptosis initiator in each specific disease condition followed by specific downstream signaling molecules. Understanding the precise mechanism of necroptosis as well as counteracting other cell death pathways in liver diseases could provide a useful insight towards achieving extensive therapeutic significance. By targeting necroptosis and/or other parallel death pathways, a significant cell loss and thus a decrement in an organ’s physiological function can be prevented.
基金supported by grants from the Science and Technology Project of Xuzhou City in China,No.XM12B017the Priority Academic Program Development of Jiangsu Higher Education Institutions in China
文摘Necroptosis is characterized by programmed necrotic cell death and autophagic activation and might be involved in the death process of dopaminergic neurons in Parkinson＇s disease. We hypothesized that necrostatin-1 could block necroptosis and give protection to dopaminergic neurons. There is likely to be crosstalk between necroptosis and other cell death pathways, such as apoptosis and autophagy. PC12 cells were pretreated with necroststin-1 1 hour before exposure to 6-hydroxydopamine. We examined cell viability, mitochondrial membrane potential and expression patterns of apoptotic and necroptotic death signaling proteins. The results showed that the autophagy/lysosomal pathway is involved in the 6-hydroxydopamine-induced death process of PC12 cells. Mitochondrial disability induced overactive autophagy, increased cathepsin B expression, and diminished Bcl-2 expression. Necrostatin-1 within a certain concentration range（5–30 μM） elevated the viability of PC12 cells, stabilized mitochondrial membrane potential, inhibited excessive autophagy, reduced the expression of LC3-II and cathepsin B, and increased Bcl-2 expression. These findings suggest that necrostatin-1 exerted a protective effect against injury on dopaminergic neurons. Necrostatin-1 interacts with the apoptosis signaling pathway during this process. This pathway could be a new neuroprotective and therapeutic target in Parkinson＇s disease.
