Regulatory T(Treg)cells are pivotal for maintaining immune homeostasis and play essential roles in various diseases,such as autoimmune diseases,graft-versus-host disease(GVHD),tumors,and infectious diseases.Treg cells...Regulatory T(Treg)cells are pivotal for maintaining immune homeostasis and play essential roles in various diseases,such as autoimmune diseases,graft-versus-host disease(GVHD),tumors,and infectious diseases.Treg cells exert suppressive function via distinct mechanisms,including inhibitory cytokines,granzyme or perforin-mediated cytolysis,metabolic disruption,and suppression of dendritic cells.Forkhead Box P3(FOXP3),the characteristic transcription factor,is essential for Treg cell function and plasticity.Cumulative evidence has demonstrated that FOXP3 activity and Treg cell function are modulated by a variety of post-translational modifications(PTMs),including ubiquitination,acetylation,phosphorylation,methylation,glycosylation,poly(ADP-ribosyl)ation,and uncharacterized modifications.This review describes Treg cell suppressive mechanisms and summarizes the current evidence on PTM regulation of FOXP3 and Treg cell function.Understanding the regulatory role of PTMs in Treg cell plasticity and function will be helpful in designing therapeutic strategies for autoimmune diseases,GVHD,tumors,and infectious diseases.展开更多
Developing favorable bio-based polymers that replace petroleum-based plastics is an essential environmental demand.Lignin is a by-product of the chemical pulping industry.It is a natural UV protection ingredient in br...Developing favorable bio-based polymers that replace petroleum-based plastics is an essential environmental demand.Lignin is a by-product of the chemical pulping industry.It is a natural UV protection ingredient in broad-spectrum(UVA and UVB)sunscreens.It could be partially and selectively acetylated in a simple,fast,and more reliable process.In this work,a composite film was prepared with UV-resistant properties through a casting method.Bio-based cellulose acetate(CA)was employed as a major matrix while nano-acetylated kraft lignin(AL-NPs)was used as filler during synthesizing UV-shielding films loaded with various amounts(1–5 wt.%)of AL-NPs.Kraft lignin was acetylated through a simple and fast microwave-assisted process using acetic acid as a solvent and acetylating agent.The physicochemical and morphological characteristics of the prepared films were evaluated using different methods,including scanning electron microscopy(SEM),Fourier Transform Infrared Spectroscopy(FTIR),X-ray diffraction analysis(XRD),mechanical testing and contact angle measurement.The UV-Vis spectroscopy optical investigation of the prepared films revealed that AL-NPs in the CA matrix showed strong UV absorption.This feature demonstrated the effectiveness of our research in developing UV-resistant bio-based polymer films.Hence,the prepared films can be considered as successful candidates to be applied in packaging applications.展开更多
Recent studies have suggested that abnormal acidification of lysosomes induces autophagic accumulation of amyloid-βin neurons,which is a key step in senile plaque formation.Therefore,resto ring normal lysosomal funct...Recent studies have suggested that abnormal acidification of lysosomes induces autophagic accumulation of amyloid-βin neurons,which is a key step in senile plaque formation.Therefore,resto ring normal lysosomal function and rebalancing lysosomal acidification in neurons in the brain may be a new treatment strategy for Alzheimer's disease.Microtubule acetylation/deacetylation plays a central role in lysosomal acidification.Here,we show that inhibiting the classic microtubule deacetylase histone deacetylase 6 with an histone deacetylase 6 shRNA or thehistone deacetylase 6 inhibitor valproic acid promoted lysosomal reacidification by modulating V-ATPase assembly in Alzheimer's disease.Fu rthermore,we found that treatment with valproic acid markedly enhanced autophagy.promoted clearance of amyloid-βaggregates,and ameliorated cognitive deficits in a mouse model of Alzheimer's disease.Our findings demonstrate a previously unknown neuroprotective mechanism in Alzheimer's disease,in which histone deacetylase 6 inhibition by valproic acid increases V-ATPase assembly and lysosomal acidification.展开更多
Chromatin modifications,including histone acetylation,play essential roles in regulating flowering.The CBP/p300 family HISTONE ACETYLTRANSFERASE 1(HAC1),which mediates histone acetylation,promotes the process of flora...Chromatin modifications,including histone acetylation,play essential roles in regulating flowering.The CBP/p300 family HISTONE ACETYLTRANSFERASE 1(HAC1),which mediates histone acetylation,promotes the process of floral transition;however,the precise mechanism remains largely unclear.Specifically,how HAC1 is involved in the flowering regulatory network and which genes are the direct targets of HAC1 during flowering regulation are still unknown.In this study,we elucidate the critical function of HAC1 in promoting flowering via exerting active epigenetic markers at two key floral integrators,FLOWERING LOCUS T(FT)and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1(SOC1),thereby regulating their expression to trigger the flowering process.We show that HAC1 physically interacts with CONSTANS(CO)in vivo and in vitro.Chromatin immunoprecipitation results indicate that HAC1 directly binds to the FT and SOC1 loci.Loss of HAC1 impairs CO-mediated transcriptional activation of FT and SOC1 in promoting flowering.Moreover,CO mutation leads to the decreased enrichment of HAC1 at FT and SOC1,indicating that CO recruits HAC1 to FT and SOC1.Finally,HAC1,as well as CO,is required for the elevated histone acetylation level at FT and SOC1.Taken together,our finding reveals that HAC1-mediated histone acetylation boots flowering via a CO-dependent activation of FT and SOC1.展开更多
Background:Accumulating studies have shown the important role of circular RNAs(circRNAs)in the oncogenesis and metastasis of various cancers.We previously reported that circACTN4 could bind with FUBP1 to promote tumor...Background:Accumulating studies have shown the important role of circular RNAs(circRNAs)in the oncogenesis and metastasis of various cancers.We previously reported that circACTN4 could bind with FUBP1 to promote tumorigenesis and the development of breast cancer(BC)by increasing the expression of MYC.However,its exact molecular mechanism and biological function have not been fully elucidated.Methods:Here,Circular RNA microarray analysis was conducted in 3 pairs of BC and paracancerous tissues.The expression of circACTN4 in BC cells and tissues was detected via reverse transcription‒quantitative PCR(RT‒qPCR).Cell Counting Kit-8(CCK-8),5-ethynyl-2-deoxyuridine(EdU),transwell migration,and invasion assays were performed to further detect the biological functions of circACTN4 in BC cells.Xenograft models were used to investigate the in vivo role of circACTN4.Fluorescence in situ hybridization,Chromatin immunoprecipitation(ChIP)‒qPCR,coimmunoprecipitation,fluorometric,western blot,and rescue experiments were performed to explore the mechanism of circACTN4.Results:Our results revealed that circACTN4 was highly expressed in BC cells and tissues.The upregulated expression of circACTN4 was significantly related to the T stage and TNM stage and poor prognosis of patients with BC.circACTN4 was located primarily in the nucleus of BC cells.Upregulation of circACTN4 significantly increased the proliferation,invasion,and growth of BC cells,whereas the downregulation of circACTN4 exerted the opposite effects and induced G1/S cell cycle arrest.Mechanistically,we showed that circACTN4 could upregulate the expression of MYC and that MYC might interact with TIP60 histone acetyltransferase to increase the recruitment of TIP60 to MYC target genes and histone H4 acetylation(AcH4),thus promoting the progression of the breast cancer cell cycle and tumorigenesis.Conclusion:Taken together,our findings reveal for the first time a new mechanism by which circACTN4 could promote oncogenesis and the development of BC by increasing the AcH4 of MYC target genes via TIP60.Therefore,circACTN4 could be a novel target for BC diagnosis and remedy.展开更多
Melanoma is an aggressive type of skin cancer notorious for its resistance to chemotherapy,radiotherapy and immunotherapy,which greatly impacts its lethality.The hedgehog(HH)signaling cascade,originally known for its ...Melanoma is an aggressive type of skin cancer notorious for its resistance to chemotherapy,radiotherapy and immunotherapy,which greatly impacts its lethality.The hedgehog(HH)signaling cascade,originally known for its roles in embryonic development,regulates growth,proliferation and cancer stem cell(CSC)self-renewal.The glioma-associated oncogene homolog(GLI)transcription factors play crucial roles in melanoma.However,oncogenic B-Raf proto-oncogene,serine/threonine kinase(BRAF)steals the spotlight by driving the aberrant activation of HH-GLI1/2 signaling.Oncogenic BRAF-driven HH-GLI1/2 signaling imparts invasive phenotype to melanoma cells and sustains CSC self-renewal.Interestingly,the transcriptional activities of GLI1 and GLI2 are suppressed by acetylation,a process that is counteracted by the deacetylating actions of histone deacetylase(HDAC)1/2.Therefore,inhibiting HDAC1/2 might keep GLI proteins in inactive acetylated form,thus representing an attractive druggable target.Notably,both HDAC1 and HDAC2 are induced by HH signaling,creating a positive feedback loop where HH signaling upregulates the expression of both HDAC1 and HDAC2.Selective inhibition of BRAF/HH/HDAC/GLI signaling axis is likely to unravel new therapeutic opportunities in melanoma.However,the precise contribution of oncogenic BRAF-driven HH signaling to therapy resistance and CSC renewal remains unclear and requires thorough investigation.In this article,we endeavored to explore the crosstalk between oncogenic BRAF and HH signaling,and the pivotal role this interaction plays in the self-renewal of melanoma stem cells.A better understanding of the molecular mechanisms governing these interactions is essential for improving melanoma treatment strategies and identifying new therapeutic targets.展开更多
Bromodomain(BRD)-containing proteins are central mediators of gene regulation,serving as key components of chromatin remodeling complexes and histone recognition scaffolds.By specifically recognizing acetylated lysine...Bromodomain(BRD)-containing proteins are central mediators of gene regulation,serving as key components of chromatin remodeling complexes and histone recognition scaffolds.By specifically recognizing acetylated lysine residues on histones(Kac)via their conserved BRD,these proteins influence chromatin structure and gene expression.Although their overarching role is well-established,the precise molecular functions and mechanisms of individual BRD proteins remain incompletely characterized.The ciliate Tetrahymena thermophila,a unicellular eukaryote with a transcriptionally active macronucleus enriched in histone acetylation,is an excellent model for exploring the significance of BRD-containing proteins.In this comprehensive review,all BRD-containing proteins encoded in the T.thermophila genome are systematically examined,including their expression profiles,histone acetylation targets,interacting proteins,and potential roles.This review lays the groundwork for future investigations into the complex roles of BRD proteins in chromatin remodeling and transcription regulation,offering insights into basic eukaryotic biology and the molecular mechanisms underlying BRD-linked diseases.展开更多
It has been reported that sea cucumber intestine hydrolysates(SCIH)could promote glutamine metabolism in mice,while there is a close connection between glutamine metabolism and insulin sensitivity.However,the effect o...It has been reported that sea cucumber intestine hydrolysates(SCIH)could promote glutamine metabolism in mice,while there is a close connection between glutamine metabolism and insulin sensitivity.However,the effect of SCIH on insulin resistance is still unclear.The results showed that SCIH hydrolyzed by flavor protease had significant activity using the insulin-induced Hep G2 cell model.Animal experiments exhibited that SCIH supplementation significantly improved the high-fat and high-sucrose diet-induced impaired glucose tolerance,reduced fasting serum glucose and glycosylated serum protein.Besides,SCIH ameliorated islet vacuolization and decreased the pancreas TNF-αand IL-6 by 32.1%and 36.2%,respectively.Immunofluorescence staining results showed that SCIH promoted insulin secretion.Interestingly,SCIH significantly increased the liver glutamine levels and upregulated the expression of glutaminase1(GLS1)and glutamate dehydrogenase 1(GLUD1).Furthermore,SCIH increased liver acetyl-Co A levels to enhance histone acetylation and activate the gene transcription and translation on glucose metabolism-related IRS/PI3K/AKT signaling pathway,thereby attenuating insulin resistance.The present findings proposed the potential value for developing functional foods in SCIH utilization.展开更多
The Rpd3 histone deacetylase complex is a multiple-subunit complex that mediates the regulation of chromatin accessibility and gene expression.Sin3,the largest subunit of Rpd3 complex,is conserved in a broad range of ...The Rpd3 histone deacetylase complex is a multiple-subunit complex that mediates the regulation of chromatin accessibility and gene expression.Sin3,the largest subunit of Rpd3 complex,is conserved in a broad range of eukaryotes.Despite being a molecular scaffold for complex assembly,the functional sites and mechanism of action of Sin3 remain unexplored.In this study,we functionally characterized a glutamate residue(E810)in Fg Sin3,the ortholog of yeast Sin3 in Fusarium graminearum(known as wheat scab fungus).Our findings indicate that E810 was important for the functions of Fg Sin3 in regulating vegetative growth,sexual reproduction,wheat infection,and DON biosynthesis.Furthermore,the E810K missense mutation restored the reduced H4 acetylation caused by the deletion of FNG1,the ortholog of the human inhibitor of growth(ING1)gene in F.graminearum.Correspondingly,the defects of the fng1 mutant were also partially rescued by the E810K mutation in Fg Sin3.Sequence alignment and evolutionary analysis revealed that E810 residue is well-conserved in fungi,animals,and plants.Based on Alphafold2 structure modeling,E810 localized on the Fg Rpd3–Fg Sin3 interface for the formation of a hydrogen bond with Fg Rpd3.Mutation of E810 disrupts the hydrogen bond and likely affects the Fg Rpd3–Fg Sin3 interaction.Taken together,E810 of Fg Sin3 is functionally associated with Fng1 in the regulation of H4 acetylation and related biological processes,probably by affecting the assembly of the Rpd3 complex.展开更多
Skin sensitization is a common adverse effect of a wide range of small reactive chemicals,leading to allergic contact dermatitis(ACD),the most frequent manifestation of immunotoxicity in humans.The prevalence of ACD i...Skin sensitization is a common adverse effect of a wide range of small reactive chemicals,leading to allergic contact dermatitis(ACD),the most frequent manifestation of immunotoxicity in humans.The prevalence of ACD is increasing,affecting up to 20%of the Western European population.This trend was particularly pronounced in high-risk occupational sectors,including healthcare,food services,metal and construction workers,and hairdressers[1].The skin sensitization adverse outcome pathway(AOP)comprises 11 elements,with four designated key events(KEs):formation of proteinhapten complexes(KE-1),inflammatory keratinocyte response(KE-2),dendritic cell(DC)activation(KE-3),and T-cell proliferation(KE-4)[2].As there is no cure for ACD,preventive strategies are of great relevance.In addition to avoiding exposure,preventive measures,such as the use of latex gloves,barrier creams,emollients,and moisturizers,often have limited effectiveness[3].展开更多
The persistence of covalently closed circular DNA(cccDNA)in hepatitis B virus(HBV)-infected hepatocytes remains a major obstacle to effective antiviral treatment.Understanding the molecular mechanisms regulating HBV c...The persistence of covalently closed circular DNA(cccDNA)in hepatitis B virus(HBV)-infected hepatocytes remains a major obstacle to effective antiviral treatment.Understanding the molecular mechanisms regulating HBV cccDNA transcription is essential for developing novel therapeutic strategies.In this study,we investigated the role of RNA binding motif protein 25(RBM25)in HBV replication,focusing on its interaction with cccDNA and its regulation of host transcription factors.The results demonstrated that RBM25 knockdown markedly inhibited HBV replication,reducing levels of HBV DNA,hepatitis B e antigen(HBeAg),hepatitis B surface antigen(HBsAg),HBV RNA,and L-HBs in HBV-replicating and infected cell models.Consistent results were observed in a mouse model hydrodynamically injected with 1.2HBV plasmid.Conversely,RBM25 overexpression significantly enhanced HBV replication.Mechanistically,RBM25 promoted HBV promoter activities by binding to cccDNA through its RE/RD and PWI domains.This effect was mediated by increased Yin Yang 1(YY1)expression,which enhanced acetylation of cccDNA-bound histones,promoting HBV transcription.Furthermore,RBM25 expression was upregulated and translocated to the nucleus following core protein expression and accumulation,while overexpression of RBM25 promoted core protein degradation.In conclusion,this study demonstrates that RBM25 is a novel host factor that enhances HBV replication by upregulating YY1-dependent transcriptional activation of cccDNA.It also reveales a reciprocal regulatory mechanism between the HBV core protein and RBM25,which helps sustain HBV replication.展开更多
Chinese bamboo flour was chemically modified by acetylation with acetic anhydride by using trichloroacetic acid as an activation agent and the optimized condition for acetylation of bamboo flour was determined as the ...Chinese bamboo flour was chemically modified by acetylation with acetic anhydride by using trichloroacetic acid as an activation agent and the optimized condition for acetylation of bamboo flour was determined as the trichloroacetic acid amount 6.0 g per 1.5-g bamboo flour, ultrasosonication duration 40 min and the reaction time 1 h at 65℃. The composition, microstructure and thermal behavior of acetylated bamboo flour were preliminarily characterized by FT-IR, DSC and SEM etc. The acetylated bamboo flour can be molded into sheets at 130℃ and 10 MPa, indicating the modified bamboo flour possesses thermalplastic performance.展开更多
Among 39 species of microbial strains,Rhodococcus sp.AS 4.1147 possessed the ability to selectively acetylate puerarin（1） at C-6 position of the glucosyl moiety.The structure of the acetylated product,6’’-O-acetyl...Among 39 species of microbial strains,Rhodococcus sp.AS 4.1147 possessed the ability to selectively acetylate puerarin（1） at C-6 position of the glucosyl moiety.The structure of the acetylated product,6’’-O-acetylpuerarin（2） was determined by the analysis of MS,NMR spectroscopic data.The isolated yield of 2 was 22.2%.展开更多
Post-translational modifications are rapid, effective and reversible ways to regulate protein stability, localization, function, and their interactions with other molecules. Post-translational modifications usually oc...Post-translational modifications are rapid, effective and reversible ways to regulate protein stability, localization, function, and their interactions with other molecules. Post-translational modifications usually occur as chemical modifications at amino acid residues, including SUMOylation, phosphorylation, palmitoylation, acetylation, etc. These complex biochemical modifications tightly regulate and control a variety of cellular processes. Several forms of post-translational modifications of huntingtin （Htt） have been described. These modifications affect Htt metabolism, protein-protein interactions and cellular toxicity. Cleavage and clearance of mutant Htt, and the interactions between mutant Htt and other cellular proteins are important biochemical events leading to Huntington＇s disease （HD）. Therefore, identifying signaling pathways of Htt modification and evaluating the significance of Htt modifications would lead to a better understanding of the normal function of wild-type Htt and the pathogenic mechanisms of mutant Htt.展开更多
基金supported by grants from the National Key R&D Program of China(2022YFC2403000 and 2021YFC2400500)the National Natural Science Foundation of China(32200728 and 32170925)+3 种基金the Clinical Research Project of Shenzhen Medical Academy of Research and Translation(C2301008)Shenzhen Science and Technology Program(JCYJ20220531100406014,JCYJ2022081800807016,RCBS20221008093336088,KQTD20210811090115019)Guangdong Basic and Applied Basic Research Foundation(2021A1515110375)the Innovative Research Team of High-level Local Universities in Shanghai(SHSMU-ZDCX20210601).
文摘Regulatory T(Treg)cells are pivotal for maintaining immune homeostasis and play essential roles in various diseases,such as autoimmune diseases,graft-versus-host disease(GVHD),tumors,and infectious diseases.Treg cells exert suppressive function via distinct mechanisms,including inhibitory cytokines,granzyme or perforin-mediated cytolysis,metabolic disruption,and suppression of dendritic cells.Forkhead Box P3(FOXP3),the characteristic transcription factor,is essential for Treg cell function and plasticity.Cumulative evidence has demonstrated that FOXP3 activity and Treg cell function are modulated by a variety of post-translational modifications(PTMs),including ubiquitination,acetylation,phosphorylation,methylation,glycosylation,poly(ADP-ribosyl)ation,and uncharacterized modifications.This review describes Treg cell suppressive mechanisms and summarizes the current evidence on PTM regulation of FOXP3 and Treg cell function.Understanding the regulatory role of PTMs in Treg cell plasticity and function will be helpful in designing therapeutic strategies for autoimmune diseases,GVHD,tumors,and infectious diseases.
文摘Developing favorable bio-based polymers that replace petroleum-based plastics is an essential environmental demand.Lignin is a by-product of the chemical pulping industry.It is a natural UV protection ingredient in broad-spectrum(UVA and UVB)sunscreens.It could be partially and selectively acetylated in a simple,fast,and more reliable process.In this work,a composite film was prepared with UV-resistant properties through a casting method.Bio-based cellulose acetate(CA)was employed as a major matrix while nano-acetylated kraft lignin(AL-NPs)was used as filler during synthesizing UV-shielding films loaded with various amounts(1–5 wt.%)of AL-NPs.Kraft lignin was acetylated through a simple and fast microwave-assisted process using acetic acid as a solvent and acetylating agent.The physicochemical and morphological characteristics of the prepared films were evaluated using different methods,including scanning electron microscopy(SEM),Fourier Transform Infrared Spectroscopy(FTIR),X-ray diffraction analysis(XRD),mechanical testing and contact angle measurement.The UV-Vis spectroscopy optical investigation of the prepared films revealed that AL-NPs in the CA matrix showed strong UV absorption.This feature demonstrated the effectiveness of our research in developing UV-resistant bio-based polymer films.Hence,the prepared films can be considered as successful candidates to be applied in packaging applications.
基金supported by the National Natural Science Foundation of China,No.82201582(to QT)Scientific and Technological Research Program of Chongqing Municipal Education Commission,No.KJQN202200457(to QT)+3 种基金General Project of Changqing Natural Science Foundation,No.cstc2021jcyjmsxmX0442(to ZL)CQMU Program for Youth Innovation in Future Medicine,No.W0044(to ZD and GH)Direct Research Project for PhD of Chongqing,No.CSTB2022BSXM-JCX0051(to ZL)the Project of the Top-Notch Talent Cultivation Program For the Graduate Students of Chongqing Medical University,No.BJRC202310(to CG)。
文摘Recent studies have suggested that abnormal acidification of lysosomes induces autophagic accumulation of amyloid-βin neurons,which is a key step in senile plaque formation.Therefore,resto ring normal lysosomal function and rebalancing lysosomal acidification in neurons in the brain may be a new treatment strategy for Alzheimer's disease.Microtubule acetylation/deacetylation plays a central role in lysosomal acidification.Here,we show that inhibiting the classic microtubule deacetylase histone deacetylase 6 with an histone deacetylase 6 shRNA or thehistone deacetylase 6 inhibitor valproic acid promoted lysosomal reacidification by modulating V-ATPase assembly in Alzheimer's disease.Fu rthermore,we found that treatment with valproic acid markedly enhanced autophagy.promoted clearance of amyloid-βaggregates,and ameliorated cognitive deficits in a mouse model of Alzheimer's disease.Our findings demonstrate a previously unknown neuroprotective mechanism in Alzheimer's disease,in which histone deacetylase 6 inhibition by valproic acid increases V-ATPase assembly and lysosomal acidification.
基金supported by the National Natural Science Foundation of China to Z.L.(32300474)and to C.L.(32470346 and 32270362)the Guangdong Basic and Applied Basic Research Foundation to C.L.(2024A1515010612)the Fundamental Research Funds for the Central Universities to X.S.(24qnpy078).
文摘Chromatin modifications,including histone acetylation,play essential roles in regulating flowering.The CBP/p300 family HISTONE ACETYLTRANSFERASE 1(HAC1),which mediates histone acetylation,promotes the process of floral transition;however,the precise mechanism remains largely unclear.Specifically,how HAC1 is involved in the flowering regulatory network and which genes are the direct targets of HAC1 during flowering regulation are still unknown.In this study,we elucidate the critical function of HAC1 in promoting flowering via exerting active epigenetic markers at two key floral integrators,FLOWERING LOCUS T(FT)and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1(SOC1),thereby regulating their expression to trigger the flowering process.We show that HAC1 physically interacts with CONSTANS(CO)in vivo and in vitro.Chromatin immunoprecipitation results indicate that HAC1 directly binds to the FT and SOC1 loci.Loss of HAC1 impairs CO-mediated transcriptional activation of FT and SOC1 in promoting flowering.Moreover,CO mutation leads to the decreased enrichment of HAC1 at FT and SOC1,indicating that CO recruits HAC1 to FT and SOC1.Finally,HAC1,as well as CO,is required for the elevated histone acetylation level at FT and SOC1.Taken together,our finding reveals that HAC1-mediated histone acetylation boots flowering via a CO-dependent activation of FT and SOC1.
基金supported by National Natural Science Foundation of China(No.82173170,Junxia ChenNo.82103089,Lei Xing)Natural Science Foundation of Chongqing,China(No.CSTB2022BSXMJCX0057,Lei Xing).
文摘Background:Accumulating studies have shown the important role of circular RNAs(circRNAs)in the oncogenesis and metastasis of various cancers.We previously reported that circACTN4 could bind with FUBP1 to promote tumorigenesis and the development of breast cancer(BC)by increasing the expression of MYC.However,its exact molecular mechanism and biological function have not been fully elucidated.Methods:Here,Circular RNA microarray analysis was conducted in 3 pairs of BC and paracancerous tissues.The expression of circACTN4 in BC cells and tissues was detected via reverse transcription‒quantitative PCR(RT‒qPCR).Cell Counting Kit-8(CCK-8),5-ethynyl-2-deoxyuridine(EdU),transwell migration,and invasion assays were performed to further detect the biological functions of circACTN4 in BC cells.Xenograft models were used to investigate the in vivo role of circACTN4.Fluorescence in situ hybridization,Chromatin immunoprecipitation(ChIP)‒qPCR,coimmunoprecipitation,fluorometric,western blot,and rescue experiments were performed to explore the mechanism of circACTN4.Results:Our results revealed that circACTN4 was highly expressed in BC cells and tissues.The upregulated expression of circACTN4 was significantly related to the T stage and TNM stage and poor prognosis of patients with BC.circACTN4 was located primarily in the nucleus of BC cells.Upregulation of circACTN4 significantly increased the proliferation,invasion,and growth of BC cells,whereas the downregulation of circACTN4 exerted the opposite effects and induced G1/S cell cycle arrest.Mechanistically,we showed that circACTN4 could upregulate the expression of MYC and that MYC might interact with TIP60 histone acetyltransferase to increase the recruitment of TIP60 to MYC target genes and histone H4 acetylation(AcH4),thus promoting the progression of the breast cancer cell cycle and tumorigenesis.Conclusion:Taken together,our findings reveal for the first time a new mechanism by which circACTN4 could promote oncogenesis and the development of BC by increasing the AcH4 of MYC target genes via TIP60.Therefore,circACTN4 could be a novel target for BC diagnosis and remedy.
基金Supported by the Science and Engineering Research Board,No.PDF/2016/002730.
文摘Melanoma is an aggressive type of skin cancer notorious for its resistance to chemotherapy,radiotherapy and immunotherapy,which greatly impacts its lethality.The hedgehog(HH)signaling cascade,originally known for its roles in embryonic development,regulates growth,proliferation and cancer stem cell(CSC)self-renewal.The glioma-associated oncogene homolog(GLI)transcription factors play crucial roles in melanoma.However,oncogenic B-Raf proto-oncogene,serine/threonine kinase(BRAF)steals the spotlight by driving the aberrant activation of HH-GLI1/2 signaling.Oncogenic BRAF-driven HH-GLI1/2 signaling imparts invasive phenotype to melanoma cells and sustains CSC self-renewal.Interestingly,the transcriptional activities of GLI1 and GLI2 are suppressed by acetylation,a process that is counteracted by the deacetylating actions of histone deacetylase(HDAC)1/2.Therefore,inhibiting HDAC1/2 might keep GLI proteins in inactive acetylated form,thus representing an attractive druggable target.Notably,both HDAC1 and HDAC2 are induced by HH signaling,creating a positive feedback loop where HH signaling upregulates the expression of both HDAC1 and HDAC2.Selective inhibition of BRAF/HH/HDAC/GLI signaling axis is likely to unravel new therapeutic opportunities in melanoma.However,the precise contribution of oncogenic BRAF-driven HH signaling to therapy resistance and CSC renewal remains unclear and requires thorough investigation.In this article,we endeavored to explore the crosstalk between oncogenic BRAF and HH signaling,and the pivotal role this interaction plays in the self-renewal of melanoma stem cells.A better understanding of the molecular mechanisms governing these interactions is essential for improving melanoma treatment strategies and identifying new therapeutic targets.
基金supported by the National Natural Science Foundation of China(32200399 to Y.W.,32125006 to S.G.)Natural Science Foundation of Shandong Province(ZR2024ZD40 to S.G.,ZR2024MC112 to Y.W.)+4 种基金Young Talent of Lifting Engineering for Science and Technology in Shandong,China(SDAST2024QTA008 to Y.W.)Fundamental Research Funds for the Central Universities(202441014 to Y.W.)Postdoctoral Fellowship Program of the China Postdoctoral Science Foundation(CPSF)(GZC20232503 to Y.L.)China Postdoctoral Science Foundation(2024M753050 to Y.L.)Laoshan Laboratory(LSKJ202203203 to S.G.)。
文摘Bromodomain(BRD)-containing proteins are central mediators of gene regulation,serving as key components of chromatin remodeling complexes and histone recognition scaffolds.By specifically recognizing acetylated lysine residues on histones(Kac)via their conserved BRD,these proteins influence chromatin structure and gene expression.Although their overarching role is well-established,the precise molecular functions and mechanisms of individual BRD proteins remain incompletely characterized.The ciliate Tetrahymena thermophila,a unicellular eukaryote with a transcriptionally active macronucleus enriched in histone acetylation,is an excellent model for exploring the significance of BRD-containing proteins.In this comprehensive review,all BRD-containing proteins encoded in the T.thermophila genome are systematically examined,including their expression profiles,histone acetylation targets,interacting proteins,and potential roles.This review lays the groundwork for future investigations into the complex roles of BRD proteins in chromatin remodeling and transcription regulation,offering insights into basic eukaryotic biology and the molecular mechanisms underlying BRD-linked diseases.
基金supported by National Key Research and Development Program of China(2023YFF1103901)the Taishan Scholars Program(tstp20240812)+2 种基金China Postdoctoral Science Foundation(2024M763107)Postdoctoral Fellowship Program of CPSF(GZC20241617)Youth Innovation Team Program of Universities in Shandong Province(2023KJ040)。
文摘It has been reported that sea cucumber intestine hydrolysates(SCIH)could promote glutamine metabolism in mice,while there is a close connection between glutamine metabolism and insulin sensitivity.However,the effect of SCIH on insulin resistance is still unclear.The results showed that SCIH hydrolyzed by flavor protease had significant activity using the insulin-induced Hep G2 cell model.Animal experiments exhibited that SCIH supplementation significantly improved the high-fat and high-sucrose diet-induced impaired glucose tolerance,reduced fasting serum glucose and glycosylated serum protein.Besides,SCIH ameliorated islet vacuolization and decreased the pancreas TNF-αand IL-6 by 32.1%and 36.2%,respectively.Immunofluorescence staining results showed that SCIH promoted insulin secretion.Interestingly,SCIH significantly increased the liver glutamine levels and upregulated the expression of glutaminase1(GLS1)and glutamate dehydrogenase 1(GLUD1).Furthermore,SCIH increased liver acetyl-Co A levels to enhance histone acetylation and activate the gene transcription and translation on glucose metabolism-related IRS/PI3K/AKT signaling pathway,thereby attenuating insulin resistance.The present findings proposed the potential value for developing functional foods in SCIH utilization.
基金supported by the grants from the National Natural Science Foundation of China(32102181)the Shaanxi Science Fund for Distinguished Young Scholars,China(2022JC-14)。
文摘The Rpd3 histone deacetylase complex is a multiple-subunit complex that mediates the regulation of chromatin accessibility and gene expression.Sin3,the largest subunit of Rpd3 complex,is conserved in a broad range of eukaryotes.Despite being a molecular scaffold for complex assembly,the functional sites and mechanism of action of Sin3 remain unexplored.In this study,we functionally characterized a glutamate residue(E810)in Fg Sin3,the ortholog of yeast Sin3 in Fusarium graminearum(known as wheat scab fungus).Our findings indicate that E810 was important for the functions of Fg Sin3 in regulating vegetative growth,sexual reproduction,wheat infection,and DON biosynthesis.Furthermore,the E810K missense mutation restored the reduced H4 acetylation caused by the deletion of FNG1,the ortholog of the human inhibitor of growth(ING1)gene in F.graminearum.Correspondingly,the defects of the fng1 mutant were also partially rescued by the E810K mutation in Fg Sin3.Sequence alignment and evolutionary analysis revealed that E810 residue is well-conserved in fungi,animals,and plants.Based on Alphafold2 structure modeling,E810 localized on the Fg Rpd3–Fg Sin3 interface for the formation of a hydrogen bond with Fg Rpd3.Mutation of E810 disrupts the hydrogen bond and likely affects the Fg Rpd3–Fg Sin3 interaction.Taken together,E810 of Fg Sin3 is functionally associated with Fng1 in the regulation of H4 acetylation and related biological processes,probably by affecting the assembly of the Rpd3 complex.
基金support was provided by the European Regional Development Fund(ERDF),through the Centro 2020 Regional Operational Programme,Portugal(Project No.:CENTRO-01-0145-FEDER-000012(HealthyAging2020))through the COMPETE 2020-Operational Programme for Competitiveness and Internationalisation and Portuguese National Funds via Fundaçao para a Ciencia e a Tecnologia,Portugal(Project Nos.:POCI-01-0145-FEDER-029369 UIDB/04539/2020,iBiMED UIDB/04501/2020,DOI identifier https://doi.org/10.54499/UIDB/04501/2020 and project reference UIDP/04501/2020,DOI identifier https://doi.org/10.54499/UIDP/04501/2020,and LA/P/0058/2020)supported by Fundaçao para a Ciencia e a Tecnologia through the individual PhD fellowships,Portugal(Grant Nos.:PD/BDE/142926/2018 and SFRH/BD/110717/2015)。
文摘Skin sensitization is a common adverse effect of a wide range of small reactive chemicals,leading to allergic contact dermatitis(ACD),the most frequent manifestation of immunotoxicity in humans.The prevalence of ACD is increasing,affecting up to 20%of the Western European population.This trend was particularly pronounced in high-risk occupational sectors,including healthcare,food services,metal and construction workers,and hairdressers[1].The skin sensitization adverse outcome pathway(AOP)comprises 11 elements,with four designated key events(KEs):formation of proteinhapten complexes(KE-1),inflammatory keratinocyte response(KE-2),dendritic cell(DC)activation(KE-3),and T-cell proliferation(KE-4)[2].As there is no cure for ACD,preventive strategies are of great relevance.In addition to avoiding exposure,preventive measures,such as the use of latex gloves,barrier creams,emollients,and moisturizers,often have limited effectiveness[3].
基金supported by the National Key R&D Program of China(No.2022YFA1303600 and No.2023YFC2306800)the National Natural Science Foundation of China(No.82372235 and No.82272315)the Sanming Project of Medicine in Shenzhen(No.SZSM202311032).
文摘The persistence of covalently closed circular DNA(cccDNA)in hepatitis B virus(HBV)-infected hepatocytes remains a major obstacle to effective antiviral treatment.Understanding the molecular mechanisms regulating HBV cccDNA transcription is essential for developing novel therapeutic strategies.In this study,we investigated the role of RNA binding motif protein 25(RBM25)in HBV replication,focusing on its interaction with cccDNA and its regulation of host transcription factors.The results demonstrated that RBM25 knockdown markedly inhibited HBV replication,reducing levels of HBV DNA,hepatitis B e antigen(HBeAg),hepatitis B surface antigen(HBsAg),HBV RNA,and L-HBs in HBV-replicating and infected cell models.Consistent results were observed in a mouse model hydrodynamically injected with 1.2HBV plasmid.Conversely,RBM25 overexpression significantly enhanced HBV replication.Mechanistically,RBM25 promoted HBV promoter activities by binding to cccDNA through its RE/RD and PWI domains.This effect was mediated by increased Yin Yang 1(YY1)expression,which enhanced acetylation of cccDNA-bound histones,promoting HBV transcription.Furthermore,RBM25 expression was upregulated and translocated to the nucleus following core protein expression and accumulation,while overexpression of RBM25 promoted core protein degradation.In conclusion,this study demonstrates that RBM25 is a novel host factor that enhances HBV replication by upregulating YY1-dependent transcriptional activation of cccDNA.It also reveales a reciprocal regulatory mechanism between the HBV core protein and RBM25,which helps sustain HBV replication.
基金Fujian Province science and technology office (2007F5030)(in part) National Natural Scince Foundation of China (grant 50473063)
文摘Chinese bamboo flour was chemically modified by acetylation with acetic anhydride by using trichloroacetic acid as an activation agent and the optimized condition for acetylation of bamboo flour was determined as the trichloroacetic acid amount 6.0 g per 1.5-g bamboo flour, ultrasosonication duration 40 min and the reaction time 1 h at 65℃. The composition, microstructure and thermal behavior of acetylated bamboo flour were preliminarily characterized by FT-IR, DSC and SEM etc. The acetylated bamboo flour can be molded into sheets at 130℃ and 10 MPa, indicating the modified bamboo flour possesses thermalplastic performance.
基金The Science & Technology Project of Guangdong Province (Grant No. 2011A080403020)the Program for New Century Excellent Talents in University (Grant No. NCET-06-0155)
文摘Among 39 species of microbial strains,Rhodococcus sp.AS 4.1147 possessed the ability to selectively acetylate puerarin（1） at C-6 position of the glucosyl moiety.The structure of the acetylated product,6’’-O-acetylpuerarin（2） was determined by the analysis of MS,NMR spectroscopic data.The isolated yield of 2 was 22.2%.
基金supported by grants from the National Natural Science Foundation of China (No.30600197)
文摘Post-translational modifications are rapid, effective and reversible ways to regulate protein stability, localization, function, and their interactions with other molecules. Post-translational modifications usually occur as chemical modifications at amino acid residues, including SUMOylation, phosphorylation, palmitoylation, acetylation, etc. These complex biochemical modifications tightly regulate and control a variety of cellular processes. Several forms of post-translational modifications of huntingtin （Htt） have been described. These modifications affect Htt metabolism, protein-protein interactions and cellular toxicity. Cleavage and clearance of mutant Htt, and the interactions between mutant Htt and other cellular proteins are important biochemical events leading to Huntington＇s disease （HD）. Therefore, identifying signaling pathways of Htt modification and evaluating the significance of Htt modifications would lead to a better understanding of the normal function of wild-type Htt and the pathogenic mechanisms of mutant Htt.
