A lasting imbalance between fatty acid synthesis and consumption leads to non-alcoholic fatty liver disease(NAFLD),coupled with hepatitis and insulin resistance.Yet the details of the underlying mechanisms are not ful...A lasting imbalance between fatty acid synthesis and consumption leads to non-alcoholic fatty liver disease(NAFLD),coupled with hepatitis and insulin resistance.Yet the details of the underlying mechanisms are not fully understood.Here,we unraveled that the expression of the transcription factor Zbtb18 is markedly decreased in the livers of both patients and murine models of NAFLD.Hepatic Zbtb18 knockout promoted NAFLD features like impaired energy expenditure and fatty acid oxidation(FAO),and induced insulin resistance.Conversely,hepatic Zbtb18 overexpression alleviated hepato-steatosis,insulin resistance,and hyperglycemia in mice fed on a high-fat diet(HFD)or in diabetic mice.Notably,in vitro and in vivo mechanistic studies revealed that Zbtb18 transcriptional activation of Farnesoid X receptor(FXR)mediated FAO and Clathrin Heavy Chain(CLTC)protein hinders NLRP3 inflammasome activity.This key mechanism by which hepatocyte’s Zbtb18 expression alleviates NAFLD and consequent liver fibrosis was further verified by FXR’s deletion and forced expression in mice and cultured mouse primary hepatocytes(MPHs).Moreover,CLTC deletion significantly abrogated the hepatic Zbtb18 overexpression-driven inhibition of NLRP3 inflammasome activity in macrophages.Altogether,Zbtb18 transcriptionally activates the FXR-mediated FAO and CLTC expression,which inhibits NLRP3 inflammasome’s activity alleviating inflammatory stress and insulin resistance,representing an attractive remedy for hepatic steatosis and fibrosis.展开更多
Although DNA mutation drives stem cell aging,how mutation-accumulated stem cells obtain clonal advantage during aging remains poorly understood.Here,using a mouse model of irradiation-induced premature aging and middl...Although DNA mutation drives stem cell aging,how mutation-accumulated stem cells obtain clonal advantage during aging remains poorly understood.Here,using a mouse model of irradiation-induced premature aging and middle-aged mice,we show that DNA mutation accumulation in hematopoietic stem cells(HSCs)during aging upregulates their surface expression of major histocompatibility complex class II(MHCII).MHCII upregulation increases the chance for recognition by bone marrow(BM)-resident regulatory T cells(Tregs),resulting in their clonal expansion and accumulation in the HSC niche.On the basis of the establishment of connexin 43(Cx43)-mediated gap junctions,BM Tregs transfer cyclic adenosine monophosphate(cAMP)to aged HSCs to diminish apoptotic priming and promote their survival via activation of protein kinase A(PKA)signaling.Importantly,targeting the HSC–Treg interaction or depleting Tregs effectively prevents the premature/physiological aging of HSCs.These findings show that aged HSCs use an active self-protective mechanism by entrapping local Tregs to construct a prosurvival niche and obtain a clonal advantage.展开更多
基金supported by National Natural Science Foundation of China(82370872,82070891,82160891,82174319,82370235)National Natural Science Foundation of Guangdong(2023A1515012618)+5 种基金Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(ZYYCXTD-C-202208)Key projects of Guangdong Provincial Department of Education(2021ZDZX2010)Basic and Applied Basic Research Project of Guangzhou(202201011501,202201010134,202201011240)the Natural Science Foundation of Jiangsu Province(BK20211055)the Jiangsu Qing Lan Project,China Postdoctoral Science Foundation(2022M710120)Guangdong Provincial Key Laboratory of TCM Pathogenesis and Prescriptions of Heart and Spleen Diseases(2022B1212010012).
文摘A lasting imbalance between fatty acid synthesis and consumption leads to non-alcoholic fatty liver disease(NAFLD),coupled with hepatitis and insulin resistance.Yet the details of the underlying mechanisms are not fully understood.Here,we unraveled that the expression of the transcription factor Zbtb18 is markedly decreased in the livers of both patients and murine models of NAFLD.Hepatic Zbtb18 knockout promoted NAFLD features like impaired energy expenditure and fatty acid oxidation(FAO),and induced insulin resistance.Conversely,hepatic Zbtb18 overexpression alleviated hepato-steatosis,insulin resistance,and hyperglycemia in mice fed on a high-fat diet(HFD)or in diabetic mice.Notably,in vitro and in vivo mechanistic studies revealed that Zbtb18 transcriptional activation of Farnesoid X receptor(FXR)mediated FAO and Clathrin Heavy Chain(CLTC)protein hinders NLRP3 inflammasome activity.This key mechanism by which hepatocyte’s Zbtb18 expression alleviates NAFLD and consequent liver fibrosis was further verified by FXR’s deletion and forced expression in mice and cultured mouse primary hepatocytes(MPHs).Moreover,CLTC deletion significantly abrogated the hepatic Zbtb18 overexpression-driven inhibition of NLRP3 inflammasome activity in macrophages.Altogether,Zbtb18 transcriptionally activates the FXR-mediated FAO and CLTC expression,which inhibits NLRP3 inflammasome’s activity alleviating inflammatory stress and insulin resistance,representing an attractive remedy for hepatic steatosis and fibrosis.
基金supported by the Key Program of the National Natural Science Foundation of China(No.81930090)the National Science Foundation for Distinguished Young Scholars of China(No.81725019)the National Natural Science Foundation of China(Nos.82273571,32171104,U22A20279,81874256,and 81872556),Chongqing Natural Science Foundation(2023NSCQ-JQX0076).
文摘Although DNA mutation drives stem cell aging,how mutation-accumulated stem cells obtain clonal advantage during aging remains poorly understood.Here,using a mouse model of irradiation-induced premature aging and middle-aged mice,we show that DNA mutation accumulation in hematopoietic stem cells(HSCs)during aging upregulates their surface expression of major histocompatibility complex class II(MHCII).MHCII upregulation increases the chance for recognition by bone marrow(BM)-resident regulatory T cells(Tregs),resulting in their clonal expansion and accumulation in the HSC niche.On the basis of the establishment of connexin 43(Cx43)-mediated gap junctions,BM Tregs transfer cyclic adenosine monophosphate(cAMP)to aged HSCs to diminish apoptotic priming and promote their survival via activation of protein kinase A(PKA)signaling.Importantly,targeting the HSC–Treg interaction or depleting Tregs effectively prevents the premature/physiological aging of HSCs.These findings show that aged HSCs use an active self-protective mechanism by entrapping local Tregs to construct a prosurvival niche and obtain a clonal advantage.
