Endogenous peptides,bioactive agents with a small molecular weight and outstanding absorbability,regulate various cellular processes and diseases.However,their role in the occurrence of Hirschsprung’s disease(HSCR)re...Endogenous peptides,bioactive agents with a small molecular weight and outstanding absorbability,regulate various cellular processes and diseases.However,their role in the occurrence of Hirschsprung’s disease(HSCR)remains unclear.Here,we found that the expression of an endogenous peptide derived from YBX1(termed PDYBX1 in this study)was upregulated in the aganglionic colonic tissue of HSCR patients,whereas its precursor protein YBX1 was downregulated.As shown by Transwell and cytoskeleton staining assays,silencing YBX1 inhibited the migration of enteric neural cells,and this effect was partially reversed after treatment with PDYBX1.Moreover,immunoprecipitation and immunofluorescence revealed that ERK2 bound to YBX1 and PDYBX1.Downregulation of YBX1 blocked the ERK1/2 pathway,but upregulation of PDYBX1 counteracted this effect by binding to ERK2,thereby promoting cell migration and proliferation.Taken together,the endogenous peptide PDYBX1 may partially alleviate the inhibition of the ERK1/2 pathway caused by the downregulation of its precursor protein YBX1 to antagonize the impairment of enteric neural cells.PDYBX1 may be exploited to design a novel potential therapeutic agent for HSCR.展开更多
Background:Myocardial infarction(MI)is associated with higher morbidity and mortality in the world,especially in cold weather.YBX1 is an RNA-binding protein that is required for pathological growth of cardiomyocyte by...Background:Myocardial infarction(MI)is associated with higher morbidity and mortality in the world,especially in cold weather.YBX1 is an RNA-binding protein that is required for pathological growth of cardiomyocyte by regulating cell growth and protein synthesis.But YBX1,as an individual RNA-binding protein,regulates cardiomyocytes through signaling cascades during myocardial infarction remain largely unexplored.Methods:In vivo,the mouse MI model was induced by ligating the left anterior descending coronary artery(LAD),and randomly divided into sham operation group,MI group,MI+YBX1 knockdown/overexpression group and MI+negative control(NC)group.The protective effect of YBX1 was verified by echocardiography and triphenyltetrazolium chloride staining.In vitro,mitochondrial-dependent apoptosis was investigated by using CCK8,TUNEL staining,reactive oxygen species(ROS)staining and JC-1 staining in hypoxic neonatal mouse cardiomyocytes(NMCMs).Results:YBX1 expression of cardiomyocytes was downregulated in a mouse model and a cellular model on the ischemic condition.Compared to mice induced by MI,YBX1 overexpression mediated by adeno-associated virus serotype 9(AAV9)vector reduced the infarcted size and improved cardiac function.Knockdown of endogenous YBX1 by shRNA partially aggravated ischemia-induced cardiac dysfunction.In hypoxic cardiomyocytes,YBX1 overexpression decreased lactic dehydrogenase(LDH)release,increased cell viability,and inhibited apoptosis by affecting the expression of apoptosis related proteins,while knockdown of endogenous YBX1 by siRNA had the opposite effect.Overexpression of YBX1 restored mitochondrial dysfunction in hypoxic NMCMs by increasing mitochondrial membrane potential and ATP content and decreasing ROS.In hypoxic NMCMs,YBX1 overexpression increased the expression of phosphorylated phosphatidylinositol 3 kinase(PI3K)/AKT,and the anti-apoptosis effect of YBX1 was eliminated t by LY294002,PI3K/AKT inhibitor.Conclusion:YBX1 protected the heart from ischemic damage by inhibiting the mitochondrial-dependent apoptosis through PI3K/AKT pathway.It is anticipated that YBX1 may serve as a novel therapeutic target for MI.展开更多
Pyruvate is an essential fuel for maintaining the tricarboxylic acid(TCA)cycle in the mitochondria.However,the precise mole-cular mechanism of pyruvate uptake by mitochondrial pyruvate carrier(MPC)is largely unknown.H...Pyruvate is an essential fuel for maintaining the tricarboxylic acid(TCA)cycle in the mitochondria.However,the precise mole-cular mechanism of pyruvate uptake by mitochondrial pyruvate carrier(MPC)is largely unknown.Here,we report that the DNA/RNA-binding protein Y-box binding protein 1(YBX1)is localized to the mitochondrial inter-membrane space by its C-terminal domain(CTD)in cancer cells.In mitochondria,YBX1 inhibits pyruvate uptake by associating with MPC1/2,thereby suppressing pyruvate-dependent TCA cycle flux.This association,in turn,promotes MPC-mediated glutaminolysis and histone lactylation.Our findings reveal that the YBX1-MPC axis exhibits a positive correlation with metastatic potential,while does not affect cell proliferation in both cultured cells and tumor xenografts.Therefore,the restricted pyruvate uptake into mitochondria potentially represents a hallmark of metastatic capacity,suggesting that the YBX1-MPC axis is a therapeutic target for combating cancer metastasis.展开更多
Objective:Identifying biomarkers that predict the efficacy and prognosis of chemoradiotherapy is important for individualized clinical treatment.We previously reported that high murine double minute 1(MDM1)expression ...Objective:Identifying biomarkers that predict the efficacy and prognosis of chemoradiotherapy is important for individualized clinical treatment.We previously reported that high murine double minute 1(MDM1)expression in patients with rectal cancer is linked to a favorable chemoradiation response.In this study the role of MDM1 in the chemoradiotherapy response in colorectal cancer(CRC)patients was evaluated.Methods:Colony formation and cell proliferation assays as well as xenograft models were used to determine if MDM1 expression affects the sensitivity of CRC cells to chemoradiation.RNA sequencing revealed that MDM1 regulates tumor protein 53(TP53)expression and apoptosis.A series of molecular biology experiments were performed to determine how MDM1 affects p53 expression.The effects of inhibitors targeting apoptosis on MDM1 knockout cells were evaluated.Results:Gene expression profiling revealed that MDM1 is a potential chemoradiotherapy sensitivity marker.The sensitivity of CRC cells to chemoradiation treatment decreased after MDM1 knockout and increased after MDM1 overexpression.MDM1 affected p53 expression,thereby regulating apoptosis.MDM1 overexpression limited YBX1 binding to TP53 promoter,regulated TP53 expression,and rendered CRC cells more sensitive to chemoradiation.In CRC cells with low MDM1 expression,a combination of apoptosis-inducing inhibitors and chemoradiation treatment restored sensitivity to cancer therapy.Conclusions:The current study showed that MDM1 expression influences the sensitivity of CRC cells to chemoradiation by influencing p53 and apoptosis pathways,which is the basis for the underlying molecular mechanism,and serves as a possible predictive marker for chemoradiotherapy prognosis.展开更多
基金supported by the National Natural Science Foundation of China(82001590,81801496,and 82270540).
文摘Endogenous peptides,bioactive agents with a small molecular weight and outstanding absorbability,regulate various cellular processes and diseases.However,their role in the occurrence of Hirschsprung’s disease(HSCR)remains unclear.Here,we found that the expression of an endogenous peptide derived from YBX1(termed PDYBX1 in this study)was upregulated in the aganglionic colonic tissue of HSCR patients,whereas its precursor protein YBX1 was downregulated.As shown by Transwell and cytoskeleton staining assays,silencing YBX1 inhibited the migration of enteric neural cells,and this effect was partially reversed after treatment with PDYBX1.Moreover,immunoprecipitation and immunofluorescence revealed that ERK2 bound to YBX1 and PDYBX1.Downregulation of YBX1 blocked the ERK1/2 pathway,but upregulation of PDYBX1 counteracted this effect by binding to ERK2,thereby promoting cell migration and proliferation.Taken together,the endogenous peptide PDYBX1 may partially alleviate the inhibition of the ERK1/2 pathway caused by the downregulation of its precursor protein YBX1 to antagonize the impairment of enteric neural cells.PDYBX1 may be exploited to design a novel potential therapeutic agent for HSCR.
基金This project was supported by Science and technology project of Xiamen Medical College(K2023-08)the National Natural Science Foundation of China(No.82170299 to Shan Hongli,No.82003757 to Lyu Lifang).
文摘Background:Myocardial infarction(MI)is associated with higher morbidity and mortality in the world,especially in cold weather.YBX1 is an RNA-binding protein that is required for pathological growth of cardiomyocyte by regulating cell growth and protein synthesis.But YBX1,as an individual RNA-binding protein,regulates cardiomyocytes through signaling cascades during myocardial infarction remain largely unexplored.Methods:In vivo,the mouse MI model was induced by ligating the left anterior descending coronary artery(LAD),and randomly divided into sham operation group,MI group,MI+YBX1 knockdown/overexpression group and MI+negative control(NC)group.The protective effect of YBX1 was verified by echocardiography and triphenyltetrazolium chloride staining.In vitro,mitochondrial-dependent apoptosis was investigated by using CCK8,TUNEL staining,reactive oxygen species(ROS)staining and JC-1 staining in hypoxic neonatal mouse cardiomyocytes(NMCMs).Results:YBX1 expression of cardiomyocytes was downregulated in a mouse model and a cellular model on the ischemic condition.Compared to mice induced by MI,YBX1 overexpression mediated by adeno-associated virus serotype 9(AAV9)vector reduced the infarcted size and improved cardiac function.Knockdown of endogenous YBX1 by shRNA partially aggravated ischemia-induced cardiac dysfunction.In hypoxic cardiomyocytes,YBX1 overexpression decreased lactic dehydrogenase(LDH)release,increased cell viability,and inhibited apoptosis by affecting the expression of apoptosis related proteins,while knockdown of endogenous YBX1 by siRNA had the opposite effect.Overexpression of YBX1 restored mitochondrial dysfunction in hypoxic NMCMs by increasing mitochondrial membrane potential and ATP content and decreasing ROS.In hypoxic NMCMs,YBX1 overexpression increased the expression of phosphorylated phosphatidylinositol 3 kinase(PI3K)/AKT,and the anti-apoptosis effect of YBX1 was eliminated t by LY294002,PI3K/AKT inhibitor.Conclusion:YBX1 protected the heart from ischemic damage by inhibiting the mitochondrial-dependent apoptosis through PI3K/AKT pathway.It is anticipated that YBX1 may serve as a novel therapeutic target for MI.
基金This study was supported by the National Key Research and Development Program of China(2022YFA0806503)grants from the National Natural Science Foundation of China(No.81972625,No.21907093)+1 种基金Dalian Science and Technology Innovation Funding(2019J12SN52)Liaoning Revitalization Talents Program(XLYC2002035).
文摘Pyruvate is an essential fuel for maintaining the tricarboxylic acid(TCA)cycle in the mitochondria.However,the precise mole-cular mechanism of pyruvate uptake by mitochondrial pyruvate carrier(MPC)is largely unknown.Here,we report that the DNA/RNA-binding protein Y-box binding protein 1(YBX1)is localized to the mitochondrial inter-membrane space by its C-terminal domain(CTD)in cancer cells.In mitochondria,YBX1 inhibits pyruvate uptake by associating with MPC1/2,thereby suppressing pyruvate-dependent TCA cycle flux.This association,in turn,promotes MPC-mediated glutaminolysis and histone lactylation.Our findings reveal that the YBX1-MPC axis exhibits a positive correlation with metastatic potential,while does not affect cell proliferation in both cultured cells and tumor xenografts.Therefore,the restricted pyruvate uptake into mitochondria potentially represents a hallmark of metastatic capacity,suggesting that the YBX1-MPC axis is a therapeutic target for combating cancer metastasis.
基金supported by grants from the National Natural Science Foundation(Grant No.81972859 to W.T.)Beijing Municipal Science&Technology Commission Grant(Grant No.D0905001040531 to D.L.)State Key Laboratory of Molecular Oncology Grant(Grant No.SKLMO-KF2023-03 to D.L.).
文摘Objective:Identifying biomarkers that predict the efficacy and prognosis of chemoradiotherapy is important for individualized clinical treatment.We previously reported that high murine double minute 1(MDM1)expression in patients with rectal cancer is linked to a favorable chemoradiation response.In this study the role of MDM1 in the chemoradiotherapy response in colorectal cancer(CRC)patients was evaluated.Methods:Colony formation and cell proliferation assays as well as xenograft models were used to determine if MDM1 expression affects the sensitivity of CRC cells to chemoradiation.RNA sequencing revealed that MDM1 regulates tumor protein 53(TP53)expression and apoptosis.A series of molecular biology experiments were performed to determine how MDM1 affects p53 expression.The effects of inhibitors targeting apoptosis on MDM1 knockout cells were evaluated.Results:Gene expression profiling revealed that MDM1 is a potential chemoradiotherapy sensitivity marker.The sensitivity of CRC cells to chemoradiation treatment decreased after MDM1 knockout and increased after MDM1 overexpression.MDM1 affected p53 expression,thereby regulating apoptosis.MDM1 overexpression limited YBX1 binding to TP53 promoter,regulated TP53 expression,and rendered CRC cells more sensitive to chemoradiation.In CRC cells with low MDM1 expression,a combination of apoptosis-inducing inhibitors and chemoradiation treatment restored sensitivity to cancer therapy.Conclusions:The current study showed that MDM1 expression influences the sensitivity of CRC cells to chemoradiation by influencing p53 and apoptosis pathways,which is the basis for the underlying molecular mechanism,and serves as a possible predictive marker for chemoradiotherapy prognosis.
