BACKGROUND Hepatocellular carcinoma(HCC)remains a lethal malignancy due to its molecular complexity and chemoresistance.Rac family small GTPase 3(RAC3),a tumorigenic GTPase understudied in HCC,drives recurrence via E2...BACKGROUND Hepatocellular carcinoma(HCC)remains a lethal malignancy due to its molecular complexity and chemoresistance.Rac family small GTPase 3(RAC3),a tumorigenic GTPase understudied in HCC,drives recurrence via E2F transcription factor 1(E2F1)-mediated transcriptional activation.This study integrates multiomics and clustered regularly interspaced short palindromic repeats(CRISPR)screening to delineate RAC3’s roles.RAC3 overexpression correlates with advanced HCC and patient age,while its knockout suppresses proliferation.Mechanistically,RAC3 dysregulates cell-cycle checkpoints through E2F1 binding.Pharmacological RAC3 inhibition disrupts tumor growth and synergizes with chemotherapy to overcome resistance.AIM To explore RAC3’s expression,clinical links,and HCC mechanisms via multiomics and functional genomics.METHODS Multiomic integration of The Cancer Genome Atlas(TCGA),Gene Expression Omnibus,and Genotype-Tissue Expression datasets was performed to analyze RAC3 mRNA expression.Immunohistochemistry quantified RAC3 protein in 108 HCC/adjacent tissue pairs.Kaplan–Meier/Cox regression assessed prognostic significance using TCGA data.CRISPR screening validated RAC3’s necessity for HCC proliferation.Functional enrichment identified associated pathways;hTFtarget/JASPAR predicted transcription factors,validated via chromatin immunoprecipitation sequencing(ChIP-seq).RESULTS RAC3 exhibited significant mRNA and protein overexpression in HCC tissues,which was correlated with advanced tumor stages and reduced overall survival rates(hazard ratio=1.82,95%CI:1.31–2.53).Genetic ablation of RAC3 suppressed HCC cell proliferation across 16 cell lines.Pathway analysis revealed RAC3’s predominant involvement in cell-cycle regulation,DNA replication,and nucleocytoplasmic transport.Mechanistic investigations identified E2F1 as a pivotal upstream transcriptional regulator,and ChIP-seq analysis validated its direct binding to the RAC3 promoter region.These findings suggest that RAC3 drives HCC progression through E2F1-mediated cell-cycle dysregulation.CONCLUSION This study identified RAC3 as a key HCC oncogenic driver;its overexpression links to poor prognosis/resistance.Targeting the RAC3/E2F1 axis offers a new therapy,which highlights RAC3 as a biomarker/target.展开更多
Osteoporosis(OP)is a prevalent metabolic bone disease.While drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the devel...Osteoporosis(OP)is a prevalent metabolic bone disease.While drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the development of more effective and safer targeted therapies.Utilizing a zebrafish(Danio rerio)larval model of osteoporosis,we explored the influence of the metabolite spermine on bone homeostasis.Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption.Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity.Notably,spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae.At the molecular level,Rac1 was identified as playing a pivotal role in mediating the antiosteoporotic effects of spermine,with P53 potentially acting downstream of Rac1.These findings were confirmed using mouse(Mus musculus)models,in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions,suggesting strong potential as a bonestrengthening agent.This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development,highlighting pivotal molecular mediators.Given their efficacy and safety,human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.展开更多
Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain unclear.It is well-recognized that age is the most important independent predictor of poor outcomes af...Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain unclear.It is well-recognized that age is the most important independent predictor of poor outcomes after stroke as older patients show poorer functional outcomes following stroke.Mounting evidence suggests that axonal regeneration and angiogenesis,the major forms of brain plasticity responsible for post-stroke recovery,diminished with advanced age.Previous studies suggest that Ras-related C3 botulinum toxin substrate(Rac)1 enhances stroke recovery as activation of Rac1 improved behavior recovery in a young mice stroke model.Here,we investigated the role of Rac1 signaling in long-term functional recovery and brain plasticity in an aged(male,18 to 22 months old C57BL/6J)brain after ischemic stroke.We found that as mice aged,Rac1 expression declined in the brain.Delayed overexpression of Rac1,using lentivirus encoding Rac1 injected day 1 after ischemic stroke,promoted cognitive(assessed using novel object recognition test)and sensorimotor(assessed using adhesive removal tests)recovery on days 14–28.This was accompanied by the increase of neurite and proliferative endothelial cells in the periinfarct zone assessed by immunostaining.In a reverse approach,pharmacological inhibition of Rac1 by intraperitoneal injection of Rac1 inhibitor NSC23766 for 14 successive days after ischemic stroke worsened the outcome with the reduction of neurite and proliferative endothelial cells.Furthermore,Rac1 inhibition reduced the activation of p21-activated kinase 1,the protein level of brain-derived neurotrophic factor,and increased the protein level of glial fibrillary acidic protein in the ischemic brain on day 28 after stroke.Our work provided insight into the mechanisms behind the diminished plasticity after cerebral ischemia in aged brains and identified Rac1 as a potential therapeutic target for improving functional recovery in the older adults after stroke.展开更多
基金Supported by National Natural Science Foundation of China,No.82260581.
文摘BACKGROUND Hepatocellular carcinoma(HCC)remains a lethal malignancy due to its molecular complexity and chemoresistance.Rac family small GTPase 3(RAC3),a tumorigenic GTPase understudied in HCC,drives recurrence via E2F transcription factor 1(E2F1)-mediated transcriptional activation.This study integrates multiomics and clustered regularly interspaced short palindromic repeats(CRISPR)screening to delineate RAC3’s roles.RAC3 overexpression correlates with advanced HCC and patient age,while its knockout suppresses proliferation.Mechanistically,RAC3 dysregulates cell-cycle checkpoints through E2F1 binding.Pharmacological RAC3 inhibition disrupts tumor growth and synergizes with chemotherapy to overcome resistance.AIM To explore RAC3’s expression,clinical links,and HCC mechanisms via multiomics and functional genomics.METHODS Multiomic integration of The Cancer Genome Atlas(TCGA),Gene Expression Omnibus,and Genotype-Tissue Expression datasets was performed to analyze RAC3 mRNA expression.Immunohistochemistry quantified RAC3 protein in 108 HCC/adjacent tissue pairs.Kaplan–Meier/Cox regression assessed prognostic significance using TCGA data.CRISPR screening validated RAC3’s necessity for HCC proliferation.Functional enrichment identified associated pathways;hTFtarget/JASPAR predicted transcription factors,validated via chromatin immunoprecipitation sequencing(ChIP-seq).RESULTS RAC3 exhibited significant mRNA and protein overexpression in HCC tissues,which was correlated with advanced tumor stages and reduced overall survival rates(hazard ratio=1.82,95%CI:1.31–2.53).Genetic ablation of RAC3 suppressed HCC cell proliferation across 16 cell lines.Pathway analysis revealed RAC3’s predominant involvement in cell-cycle regulation,DNA replication,and nucleocytoplasmic transport.Mechanistic investigations identified E2F1 as a pivotal upstream transcriptional regulator,and ChIP-seq analysis validated its direct binding to the RAC3 promoter region.These findings suggest that RAC3 drives HCC progression through E2F1-mediated cell-cycle dysregulation.CONCLUSION This study identified RAC3 as a key HCC oncogenic driver;its overexpression links to poor prognosis/resistance.Targeting the RAC3/E2F1 axis offers a new therapy,which highlights RAC3 as a biomarker/target.
文摘针对传统随机共振系统(Stochastic resonance,SR)的参数选择和未考虑历史信息影响随机共振效果的问题,提出一种基于改进布谷鸟算法(Ranking-based Adaptive Cuckoo Search,RACS)的自适应改进势模型随机共振方法。首先,对大参数信号进行移频尺度变换处理,使其满足SR的绝热近似理论要求;其次,提出一种时延分数阶偏置非线性过阻尼随机共振系统(Time-delayed Overdamped Stochastic Resonance System with Fractional Deflection Nonlinearity,TFODF-SR),并研究势模型参数对随机共振效果的影响;进而利用以信噪比作为评价函数的RACS算法自适应确定随机共振系统的结构参数;最后经过时、频域分析提取出滚动轴承故障特征。通过仿真与实测实验分析对所提出方法相比于传统SR系统及没有引入时延反馈项的ODF系统(Overdamped System with Fractional Deflection Nonlinearity,ODF)在滚动轴承故障提取上的有效性和优越性进行验证。
基金supported by the National Natural Science Foundation of China (81921002,81900970,82130027)Innovative Research Team of High-Level Local Universities in Shanghai (SHSMUZLCX20212400)+1 种基金Young Physician Innovation Team Project (QC202003)of Ninth People’s Hospital affiliated to Shanghai Jiao Tong University School of MedicineShanghai“Rising Stars of Medical Talent”Youth Development Program is also acknowledged。
文摘Osteoporosis(OP)is a prevalent metabolic bone disease.While drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the development of more effective and safer targeted therapies.Utilizing a zebrafish(Danio rerio)larval model of osteoporosis,we explored the influence of the metabolite spermine on bone homeostasis.Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption.Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity.Notably,spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae.At the molecular level,Rac1 was identified as playing a pivotal role in mediating the antiosteoporotic effects of spermine,with P53 potentially acting downstream of Rac1.These findings were confirmed using mouse(Mus musculus)models,in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions,suggesting strong potential as a bonestrengthening agent.This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development,highlighting pivotal molecular mediators.Given their efficacy and safety,human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.
基金supported by NIH grants RF1 AG069466(to JL and LDM),R01 NS099628(to JL),and AG069466(to JL and LDM)the American Heart Association award 20POST35180172(to FB)。
文摘Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain unclear.It is well-recognized that age is the most important independent predictor of poor outcomes after stroke as older patients show poorer functional outcomes following stroke.Mounting evidence suggests that axonal regeneration and angiogenesis,the major forms of brain plasticity responsible for post-stroke recovery,diminished with advanced age.Previous studies suggest that Ras-related C3 botulinum toxin substrate(Rac)1 enhances stroke recovery as activation of Rac1 improved behavior recovery in a young mice stroke model.Here,we investigated the role of Rac1 signaling in long-term functional recovery and brain plasticity in an aged(male,18 to 22 months old C57BL/6J)brain after ischemic stroke.We found that as mice aged,Rac1 expression declined in the brain.Delayed overexpression of Rac1,using lentivirus encoding Rac1 injected day 1 after ischemic stroke,promoted cognitive(assessed using novel object recognition test)and sensorimotor(assessed using adhesive removal tests)recovery on days 14–28.This was accompanied by the increase of neurite and proliferative endothelial cells in the periinfarct zone assessed by immunostaining.In a reverse approach,pharmacological inhibition of Rac1 by intraperitoneal injection of Rac1 inhibitor NSC23766 for 14 successive days after ischemic stroke worsened the outcome with the reduction of neurite and proliferative endothelial cells.Furthermore,Rac1 inhibition reduced the activation of p21-activated kinase 1,the protein level of brain-derived neurotrophic factor,and increased the protein level of glial fibrillary acidic protein in the ischemic brain on day 28 after stroke.Our work provided insight into the mechanisms behind the diminished plasticity after cerebral ischemia in aged brains and identified Rac1 as a potential therapeutic target for improving functional recovery in the older adults after stroke.
