We have studied the expression of a subset of genes encoding important tumor growth related factors in U87 glioma cells with IRE1 (inositol requiring enzyme-1) knockdown as well as their hypoxic regulation. It was sho...We have studied the expression of a subset of genes encoding important tumor growth related factors in U87 glioma cells with IRE1 (inositol requiring enzyme-1) knockdown as well as their hypoxic regulation. It was shown that the expression levels of activating transcription factor 6 (ATF6), clusterin (CLU), adhesion G protein-coupled receptor E5 (ADGRE5), transglutaminase?2, C polypeptide (TGM2), leukemia inhibitory factor (LIF), phosphoserine aminotransferase 1 (PSAT1), glyoxalase I (GLO1) and tetraspanin 13 (TSPAN13) are significantly down-regulated in glioma cells with the knockdown of IRE1 signaling enzyme. It was also shown that in glioma cells subjected to hypoxia, the expression levels of PSAT1, TSPAN13, EIF2AK3, and TGM2 genes were up-regulated, whereas the expression of ATF6 gene was down-regulated. At the same time, the expression levels of LIF, CLU, and ADGRE5 genes did not change in response to hypoxic treatment.?Furthermore, inhibition of IRE1, a key effector of an unfolded protein response pathway, modified the effect of hypoxia on the expression of most studied genes. Present study demonstrates that IRE1 knockdown down-regulated the expression of most studied genes and modified their hypoxic regulation and that these changes possibly contributed to the suppression of glioma growth in cells without IRE1 signaling enzyme function.展开更多
Left ventricular noncompaction(LVNC)is a heterogeneous disorder with undlear genetic causes and an unknown mechanism.elF3a,an important member of the Eukaryotic translation initiation factor 3(elF3)family,is involved ...Left ventricular noncompaction(LVNC)is a heterogeneous disorder with undlear genetic causes and an unknown mechanism.elF3a,an important member of the Eukaryotic translation initiation factor 3(elF3)family,is involved in multiple biological processes,indluding cell prolif eration and migration during myocardial development,suggesting it could play a role in LVNC development.To investigate the association between a novel variant(C.1145 A->G)in elF3a and LVNC,and explore potential mechanisms that could lead to the development of LVNC.A novel elF3a variant,C.1145 A->G,was identified by whole-exome sequencing in a familial pedigree with LVNC.Adenovirus vectors containing wild-type elF 3a and the mutated version were constructed and co-infected into H9C2 cells.Cell proliferation,apoptosis,cell migration,and differentiation,as well as phosphorylation of ERK1/2 were stud-ied and were measured by proliferation assays,flow cytometry,real-time PCR and Westem blot,respectively.The elF3a mutation inhibited the proliferation of H9C2 cells,induced apoptosis,promoted cell migration,and inhibited the dif ferentiation of human induced plurip-otent stem cell-derived cardiomyocytes(hiPSC-CMs).The effect of the elF3a mutation may be attributed to a decrease in expression of p-ERK1/2.A novel elF3a gene mutation disrupted the p-ERK1/2 pathway and caused decreased myocardium proliferation,differentiation,acceler-ated migration.This finding may provide some insight into the mechanism involved in LVNC development.展开更多
Enterovirus A71(EV-A71) is the major pathogen responsible for the severe hand, foot and mouth disease worldwide, for which few effective antiviral drugs are presently available. Interferon-a(IFN-a) has been used in an...Enterovirus A71(EV-A71) is the major pathogen responsible for the severe hand, foot and mouth disease worldwide, for which few effective antiviral drugs are presently available. Interferon-a(IFN-a) has been used in antiviral therapy for decades;it has been reported that EV-A71 antagonizes the antiviral activity of IFN-a based on viral 2 Apro-mediated reduction of the interferon-alpha receptor 1(IFNAR1);however, the mechanism remains unknown. Here, we showed a significant increase in IFNAR1 protein induced by IFN-a in RD cells, whereas EV-A71 infection caused obvious downregulation of the IFNAR1 protein and blockage of IFN-a signaling. Subsequently, we observed that EV-A71 2 Apro inhibited IFNAR1 translation by cleavage of the eukaryotic initiation factor 4 GI(eIF4GI), without affecting IFNAR1 m RNA levels induced by IFN-a. The inhibition of IFNAR1 translation also occurred in puromycin-induced apoptotic cells when caspase-3 cleaved e IF4 GI. Importantly, we verified that 2 Aprocould activate cellular caspase-3, which was subsequently involved in e IF4 GI cleavage mediated by 2 Apro. Furthermore, inhibition of caspase-3 activation resulted in the partial restoration of IFNAR1 in cells transfected with 2 A or infected with EV-A71, suggesting the pivotal role of both viral 2 Aproand caspase-3 activation in the disturbance of IFN-a signaling. Collectively, we elucidate a novel mechanism by which cellular caspase-3 contributes to viral 2 Apro-mediated down-regulation of IFNAR1 at the translation level during EV-A71 infection, indicating that caspase-3 inhibition could be a potential complementary strategy to improve clinical anti-EV-A71 therapy with IFN-a.展开更多
Alzheimer’s disease(AD),the most common neurodegenerative disorder,affects millions of people worldwide.In a recent publication,Guo-Jun Chen and colleagues highlight the role of matrix metalloproteinase(MMP)13(also c...Alzheimer’s disease(AD),the most common neurodegenerative disorder,affects millions of people worldwide.In a recent publication,Guo-Jun Chen and colleagues highlight the role of matrix metalloproteinase(MMP)13(also called Collagenase 3)in AD pathogenesis through regulating BACE1,1 a rate-limiting enzyme for b-amyloid(Ab)peptide production.2 Proteolytic processing of amyloid precursor protein(APP)by BACE1 and g-secretase generates Ab,which accumulate in brain senile plaques in AD.3 MMPs are a group of enzymes that degrade extracellular matrix and cleave proteins involved in signal transduction.展开更多
文摘We have studied the expression of a subset of genes encoding important tumor growth related factors in U87 glioma cells with IRE1 (inositol requiring enzyme-1) knockdown as well as their hypoxic regulation. It was shown that the expression levels of activating transcription factor 6 (ATF6), clusterin (CLU), adhesion G protein-coupled receptor E5 (ADGRE5), transglutaminase?2, C polypeptide (TGM2), leukemia inhibitory factor (LIF), phosphoserine aminotransferase 1 (PSAT1), glyoxalase I (GLO1) and tetraspanin 13 (TSPAN13) are significantly down-regulated in glioma cells with the knockdown of IRE1 signaling enzyme. It was also shown that in glioma cells subjected to hypoxia, the expression levels of PSAT1, TSPAN13, EIF2AK3, and TGM2 genes were up-regulated, whereas the expression of ATF6 gene was down-regulated. At the same time, the expression levels of LIF, CLU, and ADGRE5 genes did not change in response to hypoxic treatment.?Furthermore, inhibition of IRE1, a key effector of an unfolded protein response pathway, modified the effect of hypoxia on the expression of most studied genes. Present study demonstrates that IRE1 knockdown down-regulated the expression of most studied genes and modified their hypoxic regulation and that these changes possibly contributed to the suppression of glioma growth in cells without IRE1 signaling enzyme function.
基金This work was supported by the National Natural Science Foundation of China[grant number:81570218].
文摘Left ventricular noncompaction(LVNC)is a heterogeneous disorder with undlear genetic causes and an unknown mechanism.elF3a,an important member of the Eukaryotic translation initiation factor 3(elF3)family,is involved in multiple biological processes,indluding cell prolif eration and migration during myocardial development,suggesting it could play a role in LVNC development.To investigate the association between a novel variant(C.1145 A->G)in elF3a and LVNC,and explore potential mechanisms that could lead to the development of LVNC.A novel elF3a variant,C.1145 A->G,was identified by whole-exome sequencing in a familial pedigree with LVNC.Adenovirus vectors containing wild-type elF 3a and the mutated version were constructed and co-infected into H9C2 cells.Cell proliferation,apoptosis,cell migration,and differentiation,as well as phosphorylation of ERK1/2 were stud-ied and were measured by proliferation assays,flow cytometry,real-time PCR and Westem blot,respectively.The elF3a mutation inhibited the proliferation of H9C2 cells,induced apoptosis,promoted cell migration,and inhibited the dif ferentiation of human induced plurip-otent stem cell-derived cardiomyocytes(hiPSC-CMs).The effect of the elF3a mutation may be attributed to a decrease in expression of p-ERK1/2.A novel elF3a gene mutation disrupted the p-ERK1/2 pathway and caused decreased myocardium proliferation,differentiation,acceler-ated migration.This finding may provide some insight into the mechanism involved in LVNC development.
基金grants from Beijing Natural Science Foundation(No.19G10290)National Natural Science Foundation of China(No.81772184).
文摘Enterovirus A71(EV-A71) is the major pathogen responsible for the severe hand, foot and mouth disease worldwide, for which few effective antiviral drugs are presently available. Interferon-a(IFN-a) has been used in antiviral therapy for decades;it has been reported that EV-A71 antagonizes the antiviral activity of IFN-a based on viral 2 Apro-mediated reduction of the interferon-alpha receptor 1(IFNAR1);however, the mechanism remains unknown. Here, we showed a significant increase in IFNAR1 protein induced by IFN-a in RD cells, whereas EV-A71 infection caused obvious downregulation of the IFNAR1 protein and blockage of IFN-a signaling. Subsequently, we observed that EV-A71 2 Apro inhibited IFNAR1 translation by cleavage of the eukaryotic initiation factor 4 GI(eIF4GI), without affecting IFNAR1 m RNA levels induced by IFN-a. The inhibition of IFNAR1 translation also occurred in puromycin-induced apoptotic cells when caspase-3 cleaved e IF4 GI. Importantly, we verified that 2 Aprocould activate cellular caspase-3, which was subsequently involved in e IF4 GI cleavage mediated by 2 Apro. Furthermore, inhibition of caspase-3 activation resulted in the partial restoration of IFNAR1 in cells transfected with 2 A or infected with EV-A71, suggesting the pivotal role of both viral 2 Aproand caspase-3 activation in the disturbance of IFN-a signaling. Collectively, we elucidate a novel mechanism by which cellular caspase-3 contributes to viral 2 Apro-mediated down-regulation of IFNAR1 at the translation level during EV-A71 infection, indicating that caspase-3 inhibition could be a potential complementary strategy to improve clinical anti-EV-A71 therapy with IFN-a.
基金Research in the Thinakaran laboratory is supported by the United States Department of Health and Human Services,National Institutes of Health grants AG054223,AG056061,and AG057290.
文摘Alzheimer’s disease(AD),the most common neurodegenerative disorder,affects millions of people worldwide.In a recent publication,Guo-Jun Chen and colleagues highlight the role of matrix metalloproteinase(MMP)13(also called Collagenase 3)in AD pathogenesis through regulating BACE1,1 a rate-limiting enzyme for b-amyloid(Ab)peptide production.2 Proteolytic processing of amyloid precursor protein(APP)by BACE1 and g-secretase generates Ab,which accumulate in brain senile plaques in AD.3 MMPs are a group of enzymes that degrade extracellular matrix and cleave proteins involved in signal transduction.
