The incidence and mortality rate of lung cancer rank among the highest worldwide,severely endangering human health and life.Metformin,an anti-diabetes drug,has been shown to elicit anticancer activities in various tum...The incidence and mortality rate of lung cancer rank among the highest worldwide,severely endangering human health and life.Metformin,an anti-diabetes drug,has been shown to elicit anticancer activities in various tumors.However,its underlying mechanisms remain elusive.In this work,we explore the role of receptor-interacting protein 1(RIP1)which plays a crucial role in the process of cell death,in metformin-induced anticancer activities in lung cancer.Metformin inhibits lung cancer cell proliferation in a dose-dependent manner and promotes apoptotic cell death,as evidenced by metformin-induced PARP and caspase cleavage.Furthermore,the pan-caspase inhibitor z-VAD-fmk reverses metformin-induced cell death.Western blot and qPCR results suggest that metformin markedly downregulates RIP1 expression without affecting its mRNA and ubiquitination levels(0 vs 80 mmol/L,100%vs 20%,100%vs 15%).Additionally,co-immunoprecipitation and immunofluorescence results reveal that metformin may suppress RIP1 expression in an Hsp70-dependent manner,as metformin promotes Hsp70 degradation,and Hsp70 endogenously interacts with RIP1.Subsequent CCK-8,flow cytometry,and Western blot analyses suggest that metformin decreases Hsp70/RIP1 expression through AMPK/PKA/GSK-3βaxis.Consistently,results from a subcutaneous transplant tumor model indicate that metformin retards tumor growth without affecting mouse body weight.Collectively,these data highlight the part of RIP1 in metformin-induced anticancer activities in lung cancer in vitro and in vivo,providing novel strategy for lung cancer administration.展开更多
Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid...Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid(RA)can suppress the neurotoxic effects of CO.This study further explores,in vivo and in vitro,the molecular mechanisms by which RA alleviates CO-induced central nervous system damage.Methods:A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO,and a DEACMP animal model was established in adult Kunming mice.Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay and Annexin V/propidium iodide(PI)double staining.The transcriptional and protein expression of each gene was detected using real time fluorescence quantitative PCR(RT-qPCR)and Western blotting.Long noncoding RNA(lncRNA)SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes.In DEACMP mice,SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression.Results:RA at 10 and 20μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes,downregulation of SNHG15 and LINGO-1,and upregulation of brain-derived neurotrophic factor(BDNF)and tyrosine kinase receptor B(TrkB)(all P<0.05).Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity(all P<0.05).Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels(all P<0.05).Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP(all P<0.05).Conclusion:RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes,thereby reducing central nervous system injury and exerting neuroprotective effects.LncRNA SNHG15 and LINGO-1 are key molecules mediating RA induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway.These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.展开更多
HfO_(2)基薄膜由于其与互补金属氧化物半导体(complementary metal oxide-semiconductor,CMOS)工艺的兼容性以及在微小尺寸下保持铁电性的能力,在高密度逻辑器件和非易失性存储器等新型器件中具有广阔的应用前景。在HfO_(2)基薄膜中,亚...HfO_(2)基薄膜由于其与互补金属氧化物半导体(complementary metal oxide-semiconductor,CMOS)工艺的兼容性以及在微小尺寸下保持铁电性的能力,在高密度逻辑器件和非易失性存储器等新型器件中具有广阔的应用前景。在HfO_(2)基薄膜中,亚稳铁电相(正交相)的稳定调控及铁电性的优化对于实现高性能铁电器件至关重要。系统研究了La_(1-x)Sr_(x) MnO_(3)(L(S)MO)底电极中Sr掺杂比例对Hf_(0.5)Zr_(0.5) O_(2)(HZO)铁电薄膜正交相和铁电极化的影响,通过X射线衍射(X-Ray Diffraction,XRD)和铁电极化分析发现,底电极中Sr掺杂浓度显著影响HZO薄膜的铁电性,当Sr掺杂比例为30%时(La_(0.7)Sr_(0.3)MnO_(3)),其上的HZO薄膜具有最强的铁电正交相衍射峰强度,展现出最高的极化(25μC/cm^(2)),两者呈正相关,进一步证实了正交相HZO的铁电性。研究为外延HZO薄膜的底电极选择提供了重要实验依据,对HfO_(2)基铁电器件的设计与优化具有指导意义。展开更多
文摘The incidence and mortality rate of lung cancer rank among the highest worldwide,severely endangering human health and life.Metformin,an anti-diabetes drug,has been shown to elicit anticancer activities in various tumors.However,its underlying mechanisms remain elusive.In this work,we explore the role of receptor-interacting protein 1(RIP1)which plays a crucial role in the process of cell death,in metformin-induced anticancer activities in lung cancer.Metformin inhibits lung cancer cell proliferation in a dose-dependent manner and promotes apoptotic cell death,as evidenced by metformin-induced PARP and caspase cleavage.Furthermore,the pan-caspase inhibitor z-VAD-fmk reverses metformin-induced cell death.Western blot and qPCR results suggest that metformin markedly downregulates RIP1 expression without affecting its mRNA and ubiquitination levels(0 vs 80 mmol/L,100%vs 20%,100%vs 15%).Additionally,co-immunoprecipitation and immunofluorescence results reveal that metformin may suppress RIP1 expression in an Hsp70-dependent manner,as metformin promotes Hsp70 degradation,and Hsp70 endogenously interacts with RIP1.Subsequent CCK-8,flow cytometry,and Western blot analyses suggest that metformin decreases Hsp70/RIP1 expression through AMPK/PKA/GSK-3βaxis.Consistently,results from a subcutaneous transplant tumor model indicate that metformin retards tumor growth without affecting mouse body weight.Collectively,these data highlight the part of RIP1 in metformin-induced anticancer activities in lung cancer in vitro and in vivo,providing novel strategy for lung cancer administration.
基金supported by the Natural Science Foundation of Hunan Province(2021JJ31089)the Scientific Research Project of Health Commission of Hunan Province(202203104548),China。
文摘Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid(RA)can suppress the neurotoxic effects of CO.This study further explores,in vivo and in vitro,the molecular mechanisms by which RA alleviates CO-induced central nervous system damage.Methods:A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO,and a DEACMP animal model was established in adult Kunming mice.Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay and Annexin V/propidium iodide(PI)double staining.The transcriptional and protein expression of each gene was detected using real time fluorescence quantitative PCR(RT-qPCR)and Western blotting.Long noncoding RNA(lncRNA)SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes.In DEACMP mice,SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression.Results:RA at 10 and 20μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes,downregulation of SNHG15 and LINGO-1,and upregulation of brain-derived neurotrophic factor(BDNF)and tyrosine kinase receptor B(TrkB)(all P<0.05).Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity(all P<0.05).Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels(all P<0.05).Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP(all P<0.05).Conclusion:RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes,thereby reducing central nervous system injury and exerting neuroprotective effects.LncRNA SNHG15 and LINGO-1 are key molecules mediating RA induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway.These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
