SIRT6 is a NAD＊-dependent histone deacetylase and has been implicated in the regulation of genomic stability, DNA repair, metabolic homeostasis and several diseases. The effect of SIRT6 in cerebral ischemia and oxyge...SIRT6 is a NAD＊-dependent histone deacetylase and has been implicated in the regulation of genomic stability, DNA repair, metabolic homeostasis and several diseases. The effect of SIRT6 in cerebral ischemia and oxygen/glucose deprivation （OGD） has been reported, however the role of SIRT6 in oxidative stress damage remains unclear. Here we used SH-SY5Y neuronal cells and found that overexpression of SIRT6 led to decreased cell viability and increased necrotic cell death and reactive oxygen species （ROS） production under oxidative stress. Mechanistic study revealed that SlRT6 induced autophagy via attenuation of AKT signaling and treatment with autophagy inhibitor 3-MA or knockdown of autophagy-related protein Atg5 rescued HzO2-induced neuronal injury. Conversely, SIRT6 inhibition suppressed autophagy and reduced oxidative stressinduced neuronal damage. These results suggest that SIRT6 might be a potential therapeutic target for neuroprotection.展开更多
Focal ischemic stroke（FIS）results from the lack of blood flow in a particular region of the brain and accounts for about 80%of all human strokes.Although tremendous efforts have been made in translational research,t...Focal ischemic stroke（FIS）results from the lack of blood flow in a particular region of the brain and accounts for about 80%of all human strokes.Although tremendous efforts have been made in translational research,the treatment strategies are still limited.Tissue plasminogen activator is the only FDA-approved drug currently available for acute stroke treatment,展开更多
Micro RNA-365(mi R-365) is upregulated in the ischemic brain and is involved in oxidative damage in the diabetic rat. However, it is unclear whether mi R-365 regulates oxidative stress(OS)-mediated neuronal damage aft...Micro RNA-365(mi R-365) is upregulated in the ischemic brain and is involved in oxidative damage in the diabetic rat. However, it is unclear whether mi R-365 regulates oxidative stress(OS)-mediated neuronal damage after ischemia. Here, we used a transient middle cerebral artery occlusion model in rats and the hydrogen peroxide-induced OS model in primary cultured neurons to assess the roles of mi R-365 in neuronal damage. We found that mi R-365 exacerbated ischemic brain injury and OS-induced neuronal damage and was associated with a reduced expression of OXR1(Oxidation Resistance 1). In contrast, mi R-365 antagomir alleviated both the brain injury and OXR1 reduction. Luciferase assays indicated that mi R-365 inhibited OXR1 expression by directly targeting the 30-untranslated region of Oxr1. Furthermore, knockdown of OXR1 abolished the neuroprotective and antioxidant effects of the mi R-365 antagomir. Our results suggest that mi R-365 upregulationincreases oxidative injury by inhibiting OXR1 expression,while its downregulation protects neurons from oxidative death by enhancing OXR1-mediated antioxidant signals.展开更多
Based on previous studies that have shown flavonoids from the stems and leaves of Scutellaria baicalensis Georgi are neuroprotective agents in a naturally senile, D-galactose, aging in vivo model, as well as an in vit...Based on previous studies that have shown flavonoids from the stems and leaves of Scutellaria baicalensis Georgi are neuroprotective agents in a naturally senile, D-galactose, aging in vivo model, as well as an in vitro model of oxidative/hypoxic injury, we established a cerebral ischemia/reperfusion model in rats by middle cerebral artery occlusion. The light/electron microscopic observations found significant neuropathological changes including neuron loss or swelling and rough endoplasmic reticulum injury. Moreover, the activities of lactate dehydrogenase Na＋-K＋-ATPase, Ca2＋-ATPase and superoxide dismutase were significantly lowered, and the levels of malonaldehyde increased. In addition, the memory of rats worsened. However, treatment with flavonoids from Scutellaria baicalensis Georgi （35, 70 and 140 mg/kg） for 13 days dramatically improved the above abnormal changes. These results suggest that the ability of flavonoids from Scutellaria baicalensis Georgi in attenuating cerebral functional and morphological consequences after cerebral ischemia/reperfusion may be beneficial for the treatment of ischemic brain disease.展开更多
After hypoxia, ischemia, or inflammatory injuries to the central nervous system, the damaged cells release a large amount of adenosine triphosphate, which may cause secondary neuronal death. Autophagy is a form of cel...After hypoxia, ischemia, or inflammatory injuries to the central nervous system, the damaged cells release a large amount of adenosine triphosphate, which may cause secondary neuronal death. Autophagy is a form of cell death that also has neuroprotective effects. Cell Counting Kit assay, monodansylcadaverine staining, flow cytometry, western blotting, and real-time PCR were used to determine the effects of exogenous adenosine triphosphate treatment at different concentrations （2, 4, 6, 8, 10 mmol/L） over time （1, 2, 3, and 6 hours） on the apoptosis and autophagy of SH-SY5Y cells. High concentrations of extracellular adenosine triphosphate induced autophagy and apoptosis of SH-SYSY cells. The enhanced autophagy first appeared, and peaked at 1 hour after treatment with adenosine triphosphate. Cell apoptosis peaked at 3 hours, and persisted through 6 hours. With prolonged exposure to the adenosine triphosphate treatment, the fraction of apoptotic cells increased. These data suggest that the SH-SY5Y neural cells initiated autophagy against apoptosis within an hour of adenosine triphosphate treatment to protect themselves against injury.展开更多
文摘SIRT6 is a NAD＊-dependent histone deacetylase and has been implicated in the regulation of genomic stability, DNA repair, metabolic homeostasis and several diseases. The effect of SIRT6 in cerebral ischemia and oxygen/glucose deprivation （OGD） has been reported, however the role of SIRT6 in oxidative stress damage remains unclear. Here we used SH-SY5Y neuronal cells and found that overexpression of SIRT6 led to decreased cell viability and increased necrotic cell death and reactive oxygen species （ROS） production under oxidative stress. Mechanistic study revealed that SlRT6 induced autophagy via attenuation of AKT signaling and treatment with autophagy inhibitor 3-MA or knockdown of autophagy-related protein Atg5 rescued HzO2-induced neuronal injury. Conversely, SIRT6 inhibition suppressed autophagy and reduced oxidative stressinduced neuronal damage. These results suggest that SIRT6 might be a potential therapeutic target for neuroprotection.
基金supported by NIH NS069726 and NS094539America Heart Association 13GRANT17020004(to SD)
文摘Focal ischemic stroke（FIS）results from the lack of blood flow in a particular region of the brain and accounts for about 80%of all human strokes.Although tremendous efforts have been made in translational research,the treatment strategies are still limited.Tissue plasminogen activator is the only FDA-approved drug currently available for acute stroke treatment,
基金supported by grants from the National Natural Science Foundation of China (81030020, 81571197, and 81771268)the National Education Program of China (J0730860)
文摘Micro RNA-365(mi R-365) is upregulated in the ischemic brain and is involved in oxidative damage in the diabetic rat. However, it is unclear whether mi R-365 regulates oxidative stress(OS)-mediated neuronal damage after ischemia. Here, we used a transient middle cerebral artery occlusion model in rats and the hydrogen peroxide-induced OS model in primary cultured neurons to assess the roles of mi R-365 in neuronal damage. We found that mi R-365 exacerbated ischemic brain injury and OS-induced neuronal damage and was associated with a reduced expression of OXR1(Oxidation Resistance 1). In contrast, mi R-365 antagomir alleviated both the brain injury and OXR1 reduction. Luciferase assays indicated that mi R-365 inhibited OXR1 expression by directly targeting the 30-untranslated region of Oxr1. Furthermore, knockdown of OXR1 abolished the neuroprotective and antioxidant effects of the mi R-365 antagomir. Our results suggest that mi R-365 upregulationincreases oxidative injury by inhibiting OXR1 expression,while its downregulation protects neurons from oxidative death by enhancing OXR1-mediated antioxidant signals.
基金supported by the State Administration of Traditional Chinese Medicine of China,No. 02-03-ZP18Hebei Provincial Education Department,No. 20015Hebei Provincial Hundred Outstanding Innovated Talents,First Batch
文摘Based on previous studies that have shown flavonoids from the stems and leaves of Scutellaria baicalensis Georgi are neuroprotective agents in a naturally senile, D-galactose, aging in vivo model, as well as an in vitro model of oxidative/hypoxic injury, we established a cerebral ischemia/reperfusion model in rats by middle cerebral artery occlusion. The light/electron microscopic observations found significant neuropathological changes including neuron loss or swelling and rough endoplasmic reticulum injury. Moreover, the activities of lactate dehydrogenase Na＋-K＋-ATPase, Ca2＋-ATPase and superoxide dismutase were significantly lowered, and the levels of malonaldehyde increased. In addition, the memory of rats worsened. However, treatment with flavonoids from Scutellaria baicalensis Georgi （35, 70 and 140 mg/kg） for 13 days dramatically improved the above abnormal changes. These results suggest that the ability of flavonoids from Scutellaria baicalensis Georgi in attenuating cerebral functional and morphological consequences after cerebral ischemia/reperfusion may be beneficial for the treatment of ischemic brain disease.
基金supported by the National Natural Science Foundation of China,No.81371346,81271376
文摘After hypoxia, ischemia, or inflammatory injuries to the central nervous system, the damaged cells release a large amount of adenosine triphosphate, which may cause secondary neuronal death. Autophagy is a form of cell death that also has neuroprotective effects. Cell Counting Kit assay, monodansylcadaverine staining, flow cytometry, western blotting, and real-time PCR were used to determine the effects of exogenous adenosine triphosphate treatment at different concentrations （2, 4, 6, 8, 10 mmol/L） over time （1, 2, 3, and 6 hours） on the apoptosis and autophagy of SH-SY5Y cells. High concentrations of extracellular adenosine triphosphate induced autophagy and apoptosis of SH-SYSY cells. The enhanced autophagy first appeared, and peaked at 1 hour after treatment with adenosine triphosphate. Cell apoptosis peaked at 3 hours, and persisted through 6 hours. With prolonged exposure to the adenosine triphosphate treatment, the fraction of apoptotic cells increased. These data suggest that the SH-SY5Y neural cells initiated autophagy against apoptosis within an hour of adenosine triphosphate treatment to protect themselves against injury.
