Neural cells undergo glutamate-induced apoptosis in ischaemic brain tissue,in which prostate apoptosis response-4 gene (Par-4)is involved.Human-bone mesenehymal stem cells can be utilized as an effective therapy for i...Neural cells undergo glutamate-induced apoptosis in ischaemic brain tissue,in which prostate apoptosis response-4 gene (Par-4)is involved.Human-bone mesenehymal stem cells can be utilized as an effective therapy for ischemic brain injury.In this study,we found that glutamate could induce apoptosis in human-bone mesenehymal stem cells,accompanied by increased expression of Par-4 gene and Smac release from mitochondria.Repressing Par-4 expression attenuated the glutamate-induced apoptosis.Both Par-4 protein and E2F1 protein could bind to E2F1-binding BS3 site on Smac promoter and participated in the formation of a pro- teins-DNA complex.Moreover,in the eomplex,E2F1,not Par-4,was found to be directly bound to the Smac promoter,suggesting that Par-4 exerted indireetly its transcriptional control on the Smac gene though interacting with E2F1.Expression of full-length Par-4 in human-bone mesenchymal cells resulted in increased activity of the Smac promoter.In addition,the indirect transcripional regula- tion of Par-4 on Smac depended on its COOH terminus-mediated interaction between Par-4 and E2F1.We conclude that the forma- tion of proteins-DNA complex,containing Par-4 protein,E2F1 protein and the Smac promoter,contributes to the pro-apoptotic effect on glutamate-treated human-bone mesenchymal stem cells.展开更多
Tumor immunotherapy has achieved breakthroughs in a variety of tumors. However, the systemic absence of T cells in tumors and immunosuppressive tumor microenvironment so far limits the efficacy of immunotherapy to a s...Tumor immunotherapy has achieved breakthroughs in a variety of tumors. However, the systemic absence of T cells in tumors and immunosuppressive tumor microenvironment so far limits the efficacy of immunotherapy to a small population of patients. Therefore, novel agents to increase T-cell tumor infiltration are urgently needed in the clinic. We recently found that inhibition of the ADP-ribosylation factor 1 (Arf1)-mediated lipid metabolism not only kills cancer stem cells (CSCs) but also elicits an anti-tumor immune response. In this study, we revealed a mechanism that targeting Arf1 promotes the infiltration of cytotoxic T lymphocytes (CTLs) into tumors through the C-C chemokine ligand 5 (CCL5)- C-C chemokine receptor type 5 (CCR5) pathway. We found that blockage of Arf1 induces the production of the unsaturated fatty acid (PE 18:1) that binds and sequestrates peroxisome proliferator- activated receptor-γ (PPARγ) from the PPARγ-nuclear factor-κB (NF-κB) cytoplasmic complex. The released NF-κB was then phospho-rylated and translocated into the nucleus to regulate the transcription of chemokine CCL5. CCL5 promoted infiltration of CTLs for tumor regression. Furthermore, the combination of the Arf1 inhibitor and programmed cell death protein 1 (PD-1) blockade induced an even stronger anti-tumor immunity. Therefore, targeting Arf1 represents a novel anti-tumor immune approach by provoking T-cell tumor infiltration and may provide a new strategy for tumor immunotherapy.展开更多
Matrix metalloproteinas-9 (MMP-9) is a glycosylated endopeptidase, and hence its processing between the endoplasmic reticulum (ER), Golgi and trans-Golgi (TGN) network remains under a strict control of factors that af...Matrix metalloproteinas-9 (MMP-9) is a glycosylated endopeptidase, and hence its processing between the endoplasmic reticulum (ER), Golgi and trans-Golgi (TGN) network remains under a strict control of factors that affect the microtubule (MT) stabilization, and the recruitment and activation of coat and cargo proteins, including ADP-ribosylation factors (Arfs) and protein kinase D (PKD). Here, we report on the factors implicated in the regulation of MMP-9 secretion by salivary gland acinar cells in response to P. gingivalis LPS, and the effect of hormone, ghrelin. We show that the LPS-elicited induction in MMP-9 secretion is associated with the increase in α-tubulin acetylation and the enhancement in MT stabilization, while the modulatory effect of ghrelin is reflected in a decrease in α-tubulin acetylation. Further, the effect of the LPS occurs in concert with up-regulation in Arf-guanine nucleotide exchange factor (GEF)-mediated Arf1 activation and the TGN recruitment of PKD2, while ghrelin exerts the modulatory effect on Arf-GEF activation. Moreover, we reveal that the LPS-induced up-regulation in MMP-9 secretion is reflected in a marked increase in PKCδ-mediated PKD2 phosphorylation on Ser, while the modulatory effect of ghrelin is manifested by the SFK-PTKs-dependent phosphorylation of PKD2 on Tyr. The findings demonstrate that MT stabilization along with Arf-GEF-mediated Arf1/PKD2 activation play a major role in P. gingivalis LPS-induced up-regulation in salivary gland acinar cell MMP-9 secretion, and point the modulatory mode of action by ghrelin.展开更多
Auxin response factors (ARFs) play a central role in plants as transcriptional factors in response to auxin. The Arabidopsis ARF8 gene is a light-inducible gene and ARF8 protein might control auxin homeostasis in a ne...Auxin response factors (ARFs) play a central role in plants as transcriptional factors in response to auxin. The Arabidopsis ARF8 gene is a light-inducible gene and ARF8 protein might control auxin homeostasis in a negative feed-back fashion through regulation of GH3 gene expression. In a double mutant designated infertile line including arf8-1 (a T-DNA insertion mutant of ARF8), we isolated fertility1-1 (fer1-1), a mutant of Fer1, which acts synergistically with ARF8 to control the development of the anther and filament in Arabidopsis. Genetics analysis has demonstrated that fer 1-1 is a T-DNA insertion line, indicating that Fer1 might be cloned by inverse polymerase chain reaction (PCR) or the TAIL-PCR approach. Phenotypic identification and molecular analysis of fer 1-1 and the infertile line will be helpful to characterize the function of Fer1, to further study the function of ARF8, and to reveal the molecular mechanism underlying the interaction of Fer1 and ARF8 in controlling development of the anther and filament.展开更多
文摘Neural cells undergo glutamate-induced apoptosis in ischaemic brain tissue,in which prostate apoptosis response-4 gene (Par-4)is involved.Human-bone mesenehymal stem cells can be utilized as an effective therapy for ischemic brain injury.In this study,we found that glutamate could induce apoptosis in human-bone mesenehymal stem cells,accompanied by increased expression of Par-4 gene and Smac release from mitochondria.Repressing Par-4 expression attenuated the glutamate-induced apoptosis.Both Par-4 protein and E2F1 protein could bind to E2F1-binding BS3 site on Smac promoter and participated in the formation of a pro- teins-DNA complex.Moreover,in the eomplex,E2F1,not Par-4,was found to be directly bound to the Smac promoter,suggesting that Par-4 exerted indireetly its transcriptional control on the Smac gene though interacting with E2F1.Expression of full-length Par-4 in human-bone mesenchymal cells resulted in increased activity of the Smac promoter.In addition,the indirect transcripional regula- tion of Par-4 on Smac depended on its COOH terminus-mediated interaction between Par-4 and E2F1.We conclude that the forma- tion of proteins-DNA complex,containing Par-4 protein,E2F1 protein and the Smac promoter,contributes to the pro-apoptotic effect on glutamate-treated human-bone mesenchymal stem cells.
基金This work was financially supported by grants from the National Natural Science Foundation of China(NSFC:92057205 and 32150710518 to S.X.H.,and 82203511 to Y.W.)Greater Bay Area Institute of Precision Medicine(Guangzhou),Fudan University,China.
文摘Tumor immunotherapy has achieved breakthroughs in a variety of tumors. However, the systemic absence of T cells in tumors and immunosuppressive tumor microenvironment so far limits the efficacy of immunotherapy to a small population of patients. Therefore, novel agents to increase T-cell tumor infiltration are urgently needed in the clinic. We recently found that inhibition of the ADP-ribosylation factor 1 (Arf1)-mediated lipid metabolism not only kills cancer stem cells (CSCs) but also elicits an anti-tumor immune response. In this study, we revealed a mechanism that targeting Arf1 promotes the infiltration of cytotoxic T lymphocytes (CTLs) into tumors through the C-C chemokine ligand 5 (CCL5)- C-C chemokine receptor type 5 (CCR5) pathway. We found that blockage of Arf1 induces the production of the unsaturated fatty acid (PE 18:1) that binds and sequestrates peroxisome proliferator- activated receptor-γ (PPARγ) from the PPARγ-nuclear factor-κB (NF-κB) cytoplasmic complex. The released NF-κB was then phospho-rylated and translocated into the nucleus to regulate the transcription of chemokine CCL5. CCL5 promoted infiltration of CTLs for tumor regression. Furthermore, the combination of the Arf1 inhibitor and programmed cell death protein 1 (PD-1) blockade induced an even stronger anti-tumor immunity. Therefore, targeting Arf1 represents a novel anti-tumor immune approach by provoking T-cell tumor infiltration and may provide a new strategy for tumor immunotherapy.
文摘Matrix metalloproteinas-9 (MMP-9) is a glycosylated endopeptidase, and hence its processing between the endoplasmic reticulum (ER), Golgi and trans-Golgi (TGN) network remains under a strict control of factors that affect the microtubule (MT) stabilization, and the recruitment and activation of coat and cargo proteins, including ADP-ribosylation factors (Arfs) and protein kinase D (PKD). Here, we report on the factors implicated in the regulation of MMP-9 secretion by salivary gland acinar cells in response to P. gingivalis LPS, and the effect of hormone, ghrelin. We show that the LPS-elicited induction in MMP-9 secretion is associated with the increase in α-tubulin acetylation and the enhancement in MT stabilization, while the modulatory effect of ghrelin is reflected in a decrease in α-tubulin acetylation. Further, the effect of the LPS occurs in concert with up-regulation in Arf-guanine nucleotide exchange factor (GEF)-mediated Arf1 activation and the TGN recruitment of PKD2, while ghrelin exerts the modulatory effect on Arf-GEF activation. Moreover, we reveal that the LPS-induced up-regulation in MMP-9 secretion is reflected in a marked increase in PKCδ-mediated PKD2 phosphorylation on Ser, while the modulatory effect of ghrelin is manifested by the SFK-PTKs-dependent phosphorylation of PKD2 on Tyr. The findings demonstrate that MT stabilization along with Arf-GEF-mediated Arf1/PKD2 activation play a major role in P. gingivalis LPS-induced up-regulation in salivary gland acinar cell MMP-9 secretion, and point the modulatory mode of action by ghrelin.
文摘Auxin response factors (ARFs) play a central role in plants as transcriptional factors in response to auxin. The Arabidopsis ARF8 gene is a light-inducible gene and ARF8 protein might control auxin homeostasis in a negative feed-back fashion through regulation of GH3 gene expression. In a double mutant designated infertile line including arf8-1 (a T-DNA insertion mutant of ARF8), we isolated fertility1-1 (fer1-1), a mutant of Fer1, which acts synergistically with ARF8 to control the development of the anther and filament in Arabidopsis. Genetics analysis has demonstrated that fer 1-1 is a T-DNA insertion line, indicating that Fer1 might be cloned by inverse polymerase chain reaction (PCR) or the TAIL-PCR approach. Phenotypic identification and molecular analysis of fer 1-1 and the infertile line will be helpful to characterize the function of Fer1, to further study the function of ARF8, and to reveal the molecular mechanism underlying the interaction of Fer1 and ARF8 in controlling development of the anther and filament.
