HT22 is an immortalized mouse hippocampal neuronal cell line that does not express cholinergic and glutamate receptors like mature hippocampal neurons in vivo. This in part prevents its use as a model for mature hippo...HT22 is an immortalized mouse hippocampal neuronal cell line that does not express cholinergic and glutamate receptors like mature hippocampal neurons in vivo. This in part prevents its use as a model for mature hippocampal neurons in memory-related studies. We now report that HT22 cells were appropriately induced to differentiate and possess properties similar to those of mature hippocampal neurons in vivo, such as becoming more glutamate-receptive and excitatory. Results showed that sensitivity of HT22 cells to glutamate-induced toxicity changed dramatically when comparing undifferentiated with differentiated cells, with the half-effective concentration for differentiated cells reducing approximately two orders of magnitude. Moreover, glutamate-induced toxicity in differentiated cells, but not undifferentiated cells, was inhibited by the N-methyi-D- aspartate receptor antagonists MK-801 and memantine. Evidently, differentiated HT22 cells expressed N-methyI-D-aspartate receptors, while undifferentiated cells did not. Our experimental findings indicated that differentiation is important for immortalized cell lines to render post-mitotic neuronal properties, and that differentiated HT22 neurons represent a better model of hippocampal neurons than undifferentiated cells.展开更多
Ferroptosis is a regulated form of cell death which is considered an oxidative iron-dependent process.The lipid hydroperoxidase glutathione peroxidase 4 prevents the iron(Fe2+)-dependent formation of toxic lipid react...Ferroptosis is a regulated form of cell death which is considered an oxidative iron-dependent process.The lipid hydroperoxidase glutathione peroxidase 4 prevents the iron(Fe2+)-dependent formation of toxic lipid reactive oxygen species.While emerging evidence indicates that inhibition of glutathione peroxidase 4 as a hallmark of ferroptosis in many cancer cell lines,the involvement of this biochemical pathway in neuronal death remains largely unclear.Here,we investigate,first whether the ferroptosis key players are involved in the neuronal cell death induced by erastin.The second objective was to examine whether there is a cross talk between ferroptosis and autophagy.The third main was to address neuron response to erastin,with a special focus on ferritin and nuclear receptor coactivator 4-mediated ferritinophagy.To test this in neurons,erastin(0.5-8μM)was applied to hippocampal HT22 neurons for 16 hours.In addition,cells were cultured with the autophagy inhibitor,3-methyladenin(10 mM)and/or ferroptosis inhibitors,ferrostatin 1(10-20μM)or deferoxamine(10-200μM)before exposure to erastin.In this study,we demonstrated by immunofluorescence and western blot analysis,that erastin downregulates dramatically the expression of glutathione peroxidase 4,the sodium-independent cystine-glutamate antiporter and nuclear receptor coactivator 4.The protein levels of ferritin and mitochondrial ferritin in HT22 hippocampal neurons did not remarkably change following erastin treatment.In addition,we demonstrated that not only the ferroptosis inhibitor,ferrostatin1/deferoxamine abrogated the ferroptotic cell death induced by erastin in hippocampal HT22 neurons,but also the potent autophagy inhibitor,3-methyladenin.We conclude that(1)erastin-induced ferroptosis in hippocampal HT22 neurons,despite reduced nuclear receptor coactivator 4 levels,(2)that either nuclear receptor coactivator 4-mediated ferritinophagy does not occur or is of secondary importance in this model,(3)that ferroptosis seems to share some features of the autophagic cell death process.展开更多
Bisperoxo(1,10-phenanthroline) oxovanadate(BpV) can reportedly block the cell cycle. The present study examined whether BpV alters gene expression by affecting DNA methyltransferases(DNMTs), which would impact the cel...Bisperoxo(1,10-phenanthroline) oxovanadate(BpV) can reportedly block the cell cycle. The present study examined whether BpV alters gene expression by affecting DNA methyltransferases(DNMTs), which would impact the cell cycle. Immortalized mouse hippocampal neuronal precursor cells(HT_(22)) were treated with 0.3 or 3 μM BpV. Proliferation, morphology, and viability of HT_(22) cells were detected with an IncuCyte real-time video imaging system or inverted microscope and 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium, respectively. mRNA and protein expression of DNMTs and p21 in HT_(22) cells was detected by real-time polymerase chain reaction and immunoblotting, respectively. In addition, DNMT activity was measured with an enzyme-linked immunosorbent assay. Effects of BpV on the cell cycle were analyzed using flow cytometry. Results demonstrated that treatment with 0.3 μM BpV did not affect cell proliferation, morphology, or viability; however, treatment with 3 μM BpV decreased cell viability, increased expression of both DNMT3B mRNA and protein, and inhibited the proliferation of HT_(22) cells; and 3 μM BpV also blocked the cell cycle and increased expression of the regulatory factor p21 by increasing DNMT expression in mouse hippocampal neurons.展开更多
基金supported by grants from the Medical Research and Development Service,Department of Veterans Affairs,and resources from the Midwest Biomedical Research Foundationgrants from the Alzheimer’s Association‘Novel Pharmacological Strategies to Prevent Alzheimer’s Disease’(NPSPAD-11-202149)
文摘HT22 is an immortalized mouse hippocampal neuronal cell line that does not express cholinergic and glutamate receptors like mature hippocampal neurons in vivo. This in part prevents its use as a model for mature hippocampal neurons in memory-related studies. We now report that HT22 cells were appropriately induced to differentiate and possess properties similar to those of mature hippocampal neurons in vivo, such as becoming more glutamate-receptive and excitatory. Results showed that sensitivity of HT22 cells to glutamate-induced toxicity changed dramatically when comparing undifferentiated with differentiated cells, with the half-effective concentration for differentiated cells reducing approximately two orders of magnitude. Moreover, glutamate-induced toxicity in differentiated cells, but not undifferentiated cells, was inhibited by the N-methyi-D- aspartate receptor antagonists MK-801 and memantine. Evidently, differentiated HT22 cells expressed N-methyI-D-aspartate receptors, while undifferentiated cells did not. Our experimental findings indicated that differentiation is important for immortalized cell lines to render post-mitotic neuronal properties, and that differentiated HT22 neurons represent a better model of hippocampal neurons than undifferentiated cells.
基金supported in part by a research grant from the Messer Stiftung,No.8571013(to AR).
文摘Ferroptosis is a regulated form of cell death which is considered an oxidative iron-dependent process.The lipid hydroperoxidase glutathione peroxidase 4 prevents the iron(Fe2+)-dependent formation of toxic lipid reactive oxygen species.While emerging evidence indicates that inhibition of glutathione peroxidase 4 as a hallmark of ferroptosis in many cancer cell lines,the involvement of this biochemical pathway in neuronal death remains largely unclear.Here,we investigate,first whether the ferroptosis key players are involved in the neuronal cell death induced by erastin.The second objective was to examine whether there is a cross talk between ferroptosis and autophagy.The third main was to address neuron response to erastin,with a special focus on ferritin and nuclear receptor coactivator 4-mediated ferritinophagy.To test this in neurons,erastin(0.5-8μM)was applied to hippocampal HT22 neurons for 16 hours.In addition,cells were cultured with the autophagy inhibitor,3-methyladenin(10 mM)and/or ferroptosis inhibitors,ferrostatin 1(10-20μM)or deferoxamine(10-200μM)before exposure to erastin.In this study,we demonstrated by immunofluorescence and western blot analysis,that erastin downregulates dramatically the expression of glutathione peroxidase 4,the sodium-independent cystine-glutamate antiporter and nuclear receptor coactivator 4.The protein levels of ferritin and mitochondrial ferritin in HT22 hippocampal neurons did not remarkably change following erastin treatment.In addition,we demonstrated that not only the ferroptosis inhibitor,ferrostatin1/deferoxamine abrogated the ferroptotic cell death induced by erastin in hippocampal HT22 neurons,but also the potent autophagy inhibitor,3-methyladenin.We conclude that(1)erastin-induced ferroptosis in hippocampal HT22 neurons,despite reduced nuclear receptor coactivator 4 levels,(2)that either nuclear receptor coactivator 4-mediated ferritinophagy does not occur or is of secondary importance in this model,(3)that ferroptosis seems to share some features of the autophagic cell death process.
基金supported by the National Natural Science Foundation of China,No.81160244,81360316,81460283,81660307(all to GS)the Inner Mongolia Science Foundation of China,No.2018LH08078(to GS),2016MS(LH)0307(to SYJ)+4 种基金the Baotou Health Foundation,China,No.WSJJ2016008(to SYJ)the Inner Mongolia Educational Research Foundation of China,No.NJZY207(to GS),NJZY17243(to SCY),NJZY17250(to XLL),NJZY17251(to SYJ)the Baotou Medical College Foundation of China,No.BYJJ-DF201602,BYJJ-YF201615,BSJJ201617,BYJJ-QM201633,BYJJ-QM201656,BYJJ201502(to GS)the Science and Technology Planning Project of Baotou of China,No.CX2017-5(to GS)the National Key R&D Program of China,No.2017YFC1308405(to GS)
文摘Bisperoxo(1,10-phenanthroline) oxovanadate(BpV) can reportedly block the cell cycle. The present study examined whether BpV alters gene expression by affecting DNA methyltransferases(DNMTs), which would impact the cell cycle. Immortalized mouse hippocampal neuronal precursor cells(HT_(22)) were treated with 0.3 or 3 μM BpV. Proliferation, morphology, and viability of HT_(22) cells were detected with an IncuCyte real-time video imaging system or inverted microscope and 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium, respectively. mRNA and protein expression of DNMTs and p21 in HT_(22) cells was detected by real-time polymerase chain reaction and immunoblotting, respectively. In addition, DNMT activity was measured with an enzyme-linked immunosorbent assay. Effects of BpV on the cell cycle were analyzed using flow cytometry. Results demonstrated that treatment with 0.3 μM BpV did not affect cell proliferation, morphology, or viability; however, treatment with 3 μM BpV decreased cell viability, increased expression of both DNMT3B mRNA and protein, and inhibited the proliferation of HT_(22) cells; and 3 μM BpV also blocked the cell cycle and increased expression of the regulatory factor p21 by increasing DNMT expression in mouse hippocampal neurons.
