Background:Liver cancer stem cells(LCSCs)are recognized as pivotal drivers of hepatocellular carcinoma(HCC)progression;however,the molecular mechanisms maintaining their stem-like phenotype remain largely unresolved.T...Background:Liver cancer stem cells(LCSCs)are recognized as pivotal drivers of hepatocellular carcinoma(HCC)progression;however,the molecular mechanisms maintaining their stem-like phenotype remain largely unresolved.This work investigates the role of prefoldin subunit 6-like protein(PFDN6L)in shaping LCSC traits and promoting or restraining HCC progression.Methods:PFDN6L,a cytoskeleton-associated chaperone,was studied using multiple in vitro assays—cell growth evaluation,cell cycle profiling,and spheroid culture—alongside analyses of stemness-associated markers(SOX2,CD133,CD44).Tumorigenic capacity was assessed in xenograft mouse models,and signaling pathway interrogation was performed to define underlying mechanisms.Results:In patient samples,higher PFDN6L expression correlated with improved survival outcomes.Forced expression of PFDN6L induced G2/M arrest,diminished sphere formation,and reduced pluripotency marker expression,whereas knockdown accelerated in vivo tumor formation.Mechanistic experiments demonstrated that PFDN6L suppressesmalignancy by simultaneously dampening AKT and ERK1/2 activation,thereby impairing oncogenic signaling cascades.Conclusion:PFDN6L acts as a negative regulator of LCSC-driven tumorigenesis.Its dual blockade of AKT and ERK pathways forms the mechanistic basis of its tumor-suppressive action,supporting its potential as a prognostic biomarker and therapeutic target in HCC.展开更多
Autophagy plays an important role in tissue remodeling during insect development.The interplay between autophagy-related(ATG)proteins and caspases regulates the autophagic activity of ATGs,thereby modulating the proce...Autophagy plays an important role in tissue remodeling during insect development.The interplay between autophagy-related(ATG)proteins and caspases regulates the autophagic activity of ATGs,thereby modulating the process of autophagy.Our previous study characterized BmCaspase-8-like(BmCasp8L)as a caspase suppressor that inhibits apoptosis and immune signaling by suppressing the activation of death-related ced-3/Nedd2-like caspase(DREDD),a caspase-8 homolog in silkworm.In this study,we explored the regulatory role of BmCasp8L in autophagy.We found that the expression of Bmcasp8l increased from the late spinning stage to the pupa stage in the posterior silk gland(PSG),correlating with the expression patterns of Bmatg8 and Bmatg6.RNA interference-mediated downregulation of BmCasp8L expression significantly decreased starvation-induced autophagic influx as determined by the levels of BmATG8–phosphatidylethanolamine and the percentage of cells displaying punctate enhanced green fluorescent protein-BmATG8.Conversely,the overexpression of BmCasp8L significantly increased autophagic influx.We also found that BmCasp8L underwent autophagic degradation induced by starvation and that it was colocalized with BmATG8.Lastly,we demonstrated that BmDREDD attenuated autophagy and BmCasp8L suppressed BmDREDD-mediated cleavage of BmATG6.Taken together,our results demonstrated that BmCasp8L is a novel proautophagic molecule which suppresses BmDREDD-mediated cleavage of BmATG6 and is a target for autophagy.展开更多
Abstract The unfolded protein response(UPR)is an important protective and compensatory strategy used during endoplasmic reticulum stress caused by factors including glucose starvation,low pH,or heat shock.However,ther...Abstract The unfolded protein response(UPR)is an important protective and compensatory strategy used during endoplasmic reticulum stress caused by factors including glucose starvation,low pH,or heat shock.However,there is very little information on the possible role(s)of the UPR under adverse conditions experienced by marine invertebrates.We observed that rough endoplasmic reticulum(ER)was dramatically expanded and numerous autophagosomes were accumulated in the intestinal cells of sea cucumbers,Apostichopus japonicus,under heat stress(4 h at 25°C compared with 15°C controls).Moreover,heat stress led to sharp increases in the relative transcript and protein expression levels of two primary ER chaperones:the endoplasmic reticulum resident protein 29-like(ERP29)and protein disulfi de-isomerase A6-like(PDIA6).These results suggest a potential adaptive mechanism to deal with heat-induced stress in sea cucumber intestine.展开更多
The skeletal system is a dynamically balanced system, which undergoes continuous bone resorption and formation to maintain bone matrix homeostasis. As an important ADP-ribosylase and NAD+-dependent deacylase, SIRT6 (S...The skeletal system is a dynamically balanced system, which undergoes continuous bone resorption and formation to maintain bone matrix homeostasis. As an important ADP-ribosylase and NAD+-dependent deacylase, SIRT6 (SIR2-like protein 6) is widely expressed on various kinds of bone cells, such as chondrocytes, osteoblasts, osteoclasts. The aberration of SIRT6 impairs gene expression (e.g., NF-κB and Wnt target genes) and cellular functions (e.g., DNA repair, glucose and lipid metabolism, telomeric maintenance), which disturbs the dynamic balance and ultimately leads to several bone-related diseases. In this review, we summarize the critical roles of SIRT6 in the onset and progression of bone-related diseases including osteoporosis, osteoarthritis, rheumatoid arthritis, and intervertebral disc degeneration, as well as the relevant signaling pathways. In addition, we discuss the advances in the development of SIRT6 activators and elucidate their pharmacological profiles, which may provide novel treatment strategies for these skeletal diseases.展开更多
In plants, Vacuole H^＋-PPases（VPPs） are important Aproton pumps and encoded by multiple genes. In addition to full-length VPPs, several truncated forms are expressed, but their biological functions are unknown. In ...In plants, Vacuole H^＋-PPases（VPPs） are important Aproton pumps and encoded by multiple genes. In addition to full-length VPPs, several truncated forms are expressed, but their biological functions are unknown. In this study, we functionally characterized maize vacuole H^＋-PPase 5（ZmVPP5）, a truncated VPP in the maize genome. Although ZmVPP5 shares high sequence similarity with ZmVPP1 ZmVPP5 lacks the complete structure of the conserved proton transport and the inorganic pyrophosphatase-related domain. Phylogenetic analysis suggests that ZmVPP5 might be derived from an incomplete gene duplication event. ZmVPP5 is expressed in multiple tissues, and ZmVPP5 was detected in the plasma membrane, vacuole membrane and nuclei of maize cells. The overexpression of ZmVPP5 in yeast cells caused a hypersensitivity to salt stress. Transgenic maize lines with overexpressed ZmVPP5 also exhibited the salt hypersensitivity phenotype. A yeast two-hybrid analysis identified the ZmBag6 like protein as a putative ZmVPP5-interacting protein. The results of bimolecular luminescence complementation（Bi LC）assay suggest an interaction between ZmBag6-like protein and ZmVPP5 in vivo. Overall, this study suggests that ZmVPP5 might act as a VPP antagonist and participate in the cellular response to salt stress. Our study of ZmVPP5 has expanded the understanding of the origin and functions of truncated forms of plant VPPs.展开更多
Endoplasmic reticulum(ER)stress occurs when ER homeostasis is perturbed with accumulation of unfolded/misfolded protein or calcium depletion.The unfolded protein response(UPR),comprising of inositol-requiring enzyme 1...Endoplasmic reticulum(ER)stress occurs when ER homeostasis is perturbed with accumulation of unfolded/misfolded protein or calcium depletion.The unfolded protein response(UPR),comprising of inositol-requiring enzyme 1 a(IRE1 a),double-stranded RNA-dependent protein kinase(PKR)-like ER kinase(PERK)and activating transcription factor 6(ATF6)signaling pathways,is a protective cellular response activated by ER stress.However,UPR activation can also induce cell death upon persistent ER stress.The liver is susceptible to ER stress given its synthetic and other biological functions.Numerous studies from human liver samples and animal disease models have indicated a crucial role of ER stress and the UPR signaling pathways in the pathogenesis of liver diseases,including non-alcoholic fatty liver disease(NAFLD),alcoholic liver disease(ALD),alpha-1 antitrypsin(AAT)deficiency(AATD),cholestatic liver disease,drug-induced liver injury,ischemia/reperfusion(I/R)injury,viral hepatitis and hepatocel-lular carcinoma(HCC).Extensive investigations have demonstrated the potential underlying mechanisms of the induction of ER stress and the contribution of the UPR pathways during the development of the diseases.Moreover,ER stress and the UPR proteins and genes have become emerging therapeutic targets to treat liver diseases.展开更多
基金supported by the National Natural Science Foundation of China(Grant Numbers 82350117,82160476,32360046,82260462)First-Class Discipline Team of Kunming Medical University 2024XKTDYS07,Yunnan Provincial Department of Science and Technology Key Research and Development Plan for Social Development Special Projects(202403AC100022)+4 种基金The Fundamental Research Project of Yunnan Provincial Department of Science and Technology(202301AT070129)the Joint Special Funds for the Department of Science and Technology of Yunnan Province KunmingMedical University(Grant Number 202401AY070001-360)the Yunnan Provincial Department of Education Science Research Fund Project(Grant Number 2023Y0655,2024Y234)Yunnan Province Science and Technology Talents and Platform Plan Project(202305AF150067)Beijing Sci-Tech Innovation Medical Development Foundation KC2023-JX-0288-PM94.
文摘Background:Liver cancer stem cells(LCSCs)are recognized as pivotal drivers of hepatocellular carcinoma(HCC)progression;however,the molecular mechanisms maintaining their stem-like phenotype remain largely unresolved.This work investigates the role of prefoldin subunit 6-like protein(PFDN6L)in shaping LCSC traits and promoting or restraining HCC progression.Methods:PFDN6L,a cytoskeleton-associated chaperone,was studied using multiple in vitro assays—cell growth evaluation,cell cycle profiling,and spheroid culture—alongside analyses of stemness-associated markers(SOX2,CD133,CD44).Tumorigenic capacity was assessed in xenograft mouse models,and signaling pathway interrogation was performed to define underlying mechanisms.Results:In patient samples,higher PFDN6L expression correlated with improved survival outcomes.Forced expression of PFDN6L induced G2/M arrest,diminished sphere formation,and reduced pluripotency marker expression,whereas knockdown accelerated in vivo tumor formation.Mechanistic experiments demonstrated that PFDN6L suppressesmalignancy by simultaneously dampening AKT and ERK1/2 activation,thereby impairing oncogenic signaling cascades.Conclusion:PFDN6L acts as a negative regulator of LCSC-driven tumorigenesis.Its dual blockade of AKT and ERK pathways forms the mechanistic basis of its tumor-suppressive action,supporting its potential as a prognostic biomarker and therapeutic target in HCC.
基金supported by grants from the National Natural Science Foundation of China(No.31672495)Natural Science Foundation of Chongqing,China(cstc2020jcyj-msxmX0193).
文摘Autophagy plays an important role in tissue remodeling during insect development.The interplay between autophagy-related(ATG)proteins and caspases regulates the autophagic activity of ATGs,thereby modulating the process of autophagy.Our previous study characterized BmCaspase-8-like(BmCasp8L)as a caspase suppressor that inhibits apoptosis and immune signaling by suppressing the activation of death-related ced-3/Nedd2-like caspase(DREDD),a caspase-8 homolog in silkworm.In this study,we explored the regulatory role of BmCasp8L in autophagy.We found that the expression of Bmcasp8l increased from the late spinning stage to the pupa stage in the posterior silk gland(PSG),correlating with the expression patterns of Bmatg8 and Bmatg6.RNA interference-mediated downregulation of BmCasp8L expression significantly decreased starvation-induced autophagic influx as determined by the levels of BmATG8–phosphatidylethanolamine and the percentage of cells displaying punctate enhanced green fluorescent protein-BmATG8.Conversely,the overexpression of BmCasp8L significantly increased autophagic influx.We also found that BmCasp8L underwent autophagic degradation induced by starvation and that it was colocalized with BmATG8.Lastly,we demonstrated that BmDREDD attenuated autophagy and BmCasp8L suppressed BmDREDD-mediated cleavage of BmATG6.Taken together,our results demonstrated that BmCasp8L is a novel proautophagic molecule which suppresses BmDREDD-mediated cleavage of BmATG6 and is a target for autophagy.
基金Supported by the National Natural Science Foundation of China(No.41676124)。
文摘Abstract The unfolded protein response(UPR)is an important protective and compensatory strategy used during endoplasmic reticulum stress caused by factors including glucose starvation,low pH,or heat shock.However,there is very little information on the possible role(s)of the UPR under adverse conditions experienced by marine invertebrates.We observed that rough endoplasmic reticulum(ER)was dramatically expanded and numerous autophagosomes were accumulated in the intestinal cells of sea cucumbers,Apostichopus japonicus,under heat stress(4 h at 25°C compared with 15°C controls).Moreover,heat stress led to sharp increases in the relative transcript and protein expression levels of two primary ER chaperones:the endoplasmic reticulum resident protein 29-like(ERP29)and protein disulfi de-isomerase A6-like(PDIA6).These results suggest a potential adaptive mechanism to deal with heat-induced stress in sea cucumber intestine.
文摘The skeletal system is a dynamically balanced system, which undergoes continuous bone resorption and formation to maintain bone matrix homeostasis. As an important ADP-ribosylase and NAD+-dependent deacylase, SIRT6 (SIR2-like protein 6) is widely expressed on various kinds of bone cells, such as chondrocytes, osteoblasts, osteoclasts. The aberration of SIRT6 impairs gene expression (e.g., NF-κB and Wnt target genes) and cellular functions (e.g., DNA repair, glucose and lipid metabolism, telomeric maintenance), which disturbs the dynamic balance and ultimately leads to several bone-related diseases. In this review, we summarize the critical roles of SIRT6 in the onset and progression of bone-related diseases including osteoporosis, osteoarthritis, rheumatoid arthritis, and intervertebral disc degeneration, as well as the relevant signaling pathways. In addition, we discuss the advances in the development of SIRT6 activators and elucidate their pharmacological profiles, which may provide novel treatment strategies for these skeletal diseases.
基金supported by the National Natural Sciences Foundation of China (31425019 and 91335208)the Ministry of Science and Technology of China (2014CB138204)
文摘In plants, Vacuole H^＋-PPases（VPPs） are important Aproton pumps and encoded by multiple genes. In addition to full-length VPPs, several truncated forms are expressed, but their biological functions are unknown. In this study, we functionally characterized maize vacuole H^＋-PPase 5（ZmVPP5）, a truncated VPP in the maize genome. Although ZmVPP5 shares high sequence similarity with ZmVPP1 ZmVPP5 lacks the complete structure of the conserved proton transport and the inorganic pyrophosphatase-related domain. Phylogenetic analysis suggests that ZmVPP5 might be derived from an incomplete gene duplication event. ZmVPP5 is expressed in multiple tissues, and ZmVPP5 was detected in the plasma membrane, vacuole membrane and nuclei of maize cells. The overexpression of ZmVPP5 in yeast cells caused a hypersensitivity to salt stress. Transgenic maize lines with overexpressed ZmVPP5 also exhibited the salt hypersensitivity phenotype. A yeast two-hybrid analysis identified the ZmBag6 like protein as a putative ZmVPP5-interacting protein. The results of bimolecular luminescence complementation（Bi LC）assay suggest an interaction between ZmBag6-like protein and ZmVPP5 in vivo. Overall, this study suggests that ZmVPP5 might act as a VPP antagonist and participate in the cellular response to salt stress. Our study of ZmVPP5 has expanded the understanding of the origin and functions of truncated forms of plant VPPs.
基金This work was supported by USA National Institute of Diabetes and Digestive and Kidney Diseases(NIDDK)R01 DK093807.
文摘Endoplasmic reticulum(ER)stress occurs when ER homeostasis is perturbed with accumulation of unfolded/misfolded protein or calcium depletion.The unfolded protein response(UPR),comprising of inositol-requiring enzyme 1 a(IRE1 a),double-stranded RNA-dependent protein kinase(PKR)-like ER kinase(PERK)and activating transcription factor 6(ATF6)signaling pathways,is a protective cellular response activated by ER stress.However,UPR activation can also induce cell death upon persistent ER stress.The liver is susceptible to ER stress given its synthetic and other biological functions.Numerous studies from human liver samples and animal disease models have indicated a crucial role of ER stress and the UPR signaling pathways in the pathogenesis of liver diseases,including non-alcoholic fatty liver disease(NAFLD),alcoholic liver disease(ALD),alpha-1 antitrypsin(AAT)deficiency(AATD),cholestatic liver disease,drug-induced liver injury,ischemia/reperfusion(I/R)injury,viral hepatitis and hepatocel-lular carcinoma(HCC).Extensive investigations have demonstrated the potential underlying mechanisms of the induction of ER stress and the contribution of the UPR pathways during the development of the diseases.Moreover,ER stress and the UPR proteins and genes have become emerging therapeutic targets to treat liver diseases.
