MM： To develop a protocol for direct hepatic lineage differentiation from early developmental progenitors to a population of mature hepatocytes, METHODS： Hepatic progenitor cells and then mature hepatocytes from mou...MM： To develop a protocol for direct hepatic lineage differentiation from early developmental progenitors to a population of mature hepatocytes, METHODS： Hepatic progenitor cells and then mature hepatocytes from mouse embryonic stem （ES） cells were obtained in a sequential manner, induced by valproic acid （VPA） and cytokines （hepatocyte growth factor, epidermal growth factor and insulin）, Morphological changes of the differentiated cells were examined by phase-contrast microscopy and electron microscopy, Reverse transcription polymerase chain reaction and immunocytochemical analyses were used to evaluate the gene expression profiles of the VPA-induced hepatic progenitors and the hepatic progenitor-derived hepa- tocytes, Glycogen storage, cytochrome P450 activity, transplantation assay, differentiation of bile duct-like structures and tumorigenic analyses were performed for the functional identification of the differentiated cells, Furthermore, FACS and electron microscopy were used for the analyses of cell cycle profile and apoptosis in VPA-induced hepatic differentiated cells.RESULTS： Based on the combination of VPA and cytokines, mouse ES cells differentiated into a uniform and homogeneous cell population of hepatic progenitor cells and then matured into functional hepatocytes. The progenitor population shared several characteristics with ES cells and hepatic stem/progenitor cells, and represented a novel progenitor cell between ES and hepatic oval cells in embryonic development. The dif- ferentiated hepatocytes from progenitor cells shared typical characteristics with mature hepatocytes, including the patterns of gene expression, immunological markers,in vitro hepatocyte functions and in vivo capacity to restore acute-damaged liver function. In addition, the differentiation of hepatic progenitor cells from ES cells was accompanied by significant cell cycle arrest and selective survival of differentiating cells to-wards hepatic lineages. CONCLUSION： Hepatic cells of different developmental stages from early progenitors to matured hepatocytes can be acquired in the appropriate order based on sequential induction with VPA and cytokines.展开更多
AIM： To invesgate the ultrastructural location of midkine （MK） in nucleolus and function corresponding to its location. METHODS： To investigate the ultrastructural location of MK in nucleolus with immunoelectronic...AIM： To invesgate the ultrastructural location of midkine （MK） in nucleolus and function corresponding to its location. METHODS： To investigate the ultrastructural location of MK in nucleolus with immunoelectronic microscopy. To study the role that MK plays in ribosomal biogenesis by real-time PCR. The effect of MK on anti-apoptotic activity of HepG2 cells was studied with FITC- conjugated annexin V and propidium iodide PI double staining through FACS assay. RESULTS： MK mainly localized in the granular component （GC）, dense fibrillar component （DFC） and the border between the DFC and fibrillar center （FC）. The production of 45S precursor rRNA level was decreased significantly in the presence of MK antisense oligonucleotide in the HepG2 cells. Furthermore, it was found that exogenous MK could protect HepG2 from apoptosis significantly. CONCLUSION： MK was constitutively translocated to the nucleolus of HepG2 cells, where it accumulated and mostly distributed at DFC, GC components and at the region between FC and DFC, MK played an important role in rRNA transcription, ribosome biogenesis, and cell proliferation in HepG2 cells. MK might serve as a molecular target for therapeutic intervention of human carcinomas.展开更多
NLRP3 inflammasome activation is pivotal for cytokine secretion and pyroptosis in response to diverse stimuli,playing a crucial role in innate immunity.While extensively studied in mammals,the regulatory mechanisms go...NLRP3 inflammasome activation is pivotal for cytokine secretion and pyroptosis in response to diverse stimuli,playing a crucial role in innate immunity.While extensively studied in mammals,the regulatory mechanisms governing NLRP3 activation in non-mammalian vertebrates remain largely unexplored.Teleosts,as basal vertebrates,represent an ideal model for exploring the evolutionary trajectory of inflammasome regulation.In this study,ABE assays,confocal microscopy,and biochemical analyses were applied to systematically characterize the mechanisms underlying NLRP3 inflammasome in teleosts,using large yellow croakers(Larimichthys crocea,Lc)and zebrafish(Danio rerio,Dr)as representative models.Our findings revealed a previously unrecognized palmitoylation-dependent regulatory mechanism essential for teleost NLRP3 activation.Specifically,zDHHC18-mediated palmitoylation at a teleost-specific cysteine residue(C946 in LcNLRP3,C1037 in DrNLRP3)was required for the translocation of NLRP3 to the dispersed trans-Golgi network,facilitating its subsequent recruitment to the microtubule-organizing center.This membrane trafficking was crucial for inflammasome assembly and downstream inflammatory responses.These findings provide new insights into the distinct regulatory mechanisms of NLRP3 activation in teleosts,highlighting an evolutionary divergence that contributes to innate immunity adaptation in early vertebrates.展开更多
It was widely known that retinoic acid inducible gene I （RIG-I） functions as a cytosolic pattern recognition receptor that initiates innate antiviral immunity by detecting exogenous viral RNAs. However, recent stud-...It was widely known that retinoic acid inducible gene I （RIG-I） functions as a cytosolic pattern recognition receptor that initiates innate antiviral immunity by detecting exogenous viral RNAs. However, recent stud- ies showed that RIG-I participates in other various cellular activities by sensing endogenous RNAs under different circumstances. For example, RIG-I facilitates the therapy resistance and expansion of breast cancer cells and promotes T cell-independent B cell activation through interferon signaling activation by recognizing non-coding RNAs and endogenous retroviruses in certain situations. While in hepatocellular carcinoma and acute myeloid leukemia, RIG-I acts as a tumor suppressor through either augmenting STAT1 activation by competitively binding STAT1 against its negative regulator SliP1 or inhibiting AKT-mTOR signaling pathway by directly interacting with Src respectively. These new findings suggest that RIG-I plays more diverse roles in various cellular life activities, such as cell proliferation and differentiation, than previously known. Taken together, the function of RIG-I exceeds far beyond that of a pattern recognition receptor.展开更多
Dear Editor,Inflammatory bowel disease(IBD),a complex syndrome characterized by chronic inflammation of the gastrointestinal tract,is considered a global health problem,especially prevalent in western developed countr...Dear Editor,Inflammatory bowel disease(IBD),a complex syndrome characterized by chronic inflammation of the gastrointestinal tract,is considered a global health problem,especially prevalent in western developed countries and with accelerating incidence in the developing world over the last decade.1 To date,the primary etiology of IBD remains elusive.展开更多
基金Supported by A grant from Medicine and Health Key Project of Zhejiang Province, Science and Technology Foundation of Ministry of Health of the People’s Republic of China, No. WKJ2007-2-037Shaoxing Key Project for Science and Technology, No. 2007A23008, 2005141
文摘MM： To develop a protocol for direct hepatic lineage differentiation from early developmental progenitors to a population of mature hepatocytes, METHODS： Hepatic progenitor cells and then mature hepatocytes from mouse embryonic stem （ES） cells were obtained in a sequential manner, induced by valproic acid （VPA） and cytokines （hepatocyte growth factor, epidermal growth factor and insulin）, Morphological changes of the differentiated cells were examined by phase-contrast microscopy and electron microscopy, Reverse transcription polymerase chain reaction and immunocytochemical analyses were used to evaluate the gene expression profiles of the VPA-induced hepatic progenitors and the hepatic progenitor-derived hepa- tocytes, Glycogen storage, cytochrome P450 activity, transplantation assay, differentiation of bile duct-like structures and tumorigenic analyses were performed for the functional identification of the differentiated cells, Furthermore, FACS and electron microscopy were used for the analyses of cell cycle profile and apoptosis in VPA-induced hepatic differentiated cells.RESULTS： Based on the combination of VPA and cytokines, mouse ES cells differentiated into a uniform and homogeneous cell population of hepatic progenitor cells and then matured into functional hepatocytes. The progenitor population shared several characteristics with ES cells and hepatic stem/progenitor cells, and represented a novel progenitor cell between ES and hepatic oval cells in embryonic development. The dif- ferentiated hepatocytes from progenitor cells shared typical characteristics with mature hepatocytes, including the patterns of gene expression, immunological markers,in vitro hepatocyte functions and in vivo capacity to restore acute-damaged liver function. In addition, the differentiation of hepatic progenitor cells from ES cells was accompanied by significant cell cycle arrest and selective survival of differentiating cells to-wards hepatic lineages. CONCLUSION： Hepatic cells of different developmental stages from early progenitors to matured hepatocytes can be acquired in the appropriate order based on sequential induction with VPA and cytokines.
基金The Medical Science Research Foundation of Zhejiang Province,No.2004A083
文摘AIM： To invesgate the ultrastructural location of midkine （MK） in nucleolus and function corresponding to its location. METHODS： To investigate the ultrastructural location of MK in nucleolus with immunoelectronic microscopy. To study the role that MK plays in ribosomal biogenesis by real-time PCR. The effect of MK on anti-apoptotic activity of HepG2 cells was studied with FITC- conjugated annexin V and propidium iodide PI double staining through FACS assay. RESULTS： MK mainly localized in the granular component （GC）, dense fibrillar component （DFC） and the border between the DFC and fibrillar center （FC）. The production of 45S precursor rRNA level was decreased significantly in the presence of MK antisense oligonucleotide in the HepG2 cells. Furthermore, it was found that exogenous MK could protect HepG2 from apoptosis significantly. CONCLUSION： MK was constitutively translocated to the nucleolus of HepG2 cells, where it accumulated and mostly distributed at DFC, GC components and at the region between FC and DFC, MK played an important role in rRNA transcription, ribosome biogenesis, and cell proliferation in HepG2 cells. MK might serve as a molecular target for therapeutic intervention of human carcinomas.
基金supported by the National Natural Science Foundation of China (32473194)Natural Science Foundation of Zhejiang Province (LY23C190002)+1 种基金Natural Science Foundation of Ningbo City (202003N4011)One Health Interdisciplinary Research Project of Ningbo University (HZ202201)。
文摘NLRP3 inflammasome activation is pivotal for cytokine secretion and pyroptosis in response to diverse stimuli,playing a crucial role in innate immunity.While extensively studied in mammals,the regulatory mechanisms governing NLRP3 activation in non-mammalian vertebrates remain largely unexplored.Teleosts,as basal vertebrates,represent an ideal model for exploring the evolutionary trajectory of inflammasome regulation.In this study,ABE assays,confocal microscopy,and biochemical analyses were applied to systematically characterize the mechanisms underlying NLRP3 inflammasome in teleosts,using large yellow croakers(Larimichthys crocea,Lc)and zebrafish(Danio rerio,Dr)as representative models.Our findings revealed a previously unrecognized palmitoylation-dependent regulatory mechanism essential for teleost NLRP3 activation.Specifically,zDHHC18-mediated palmitoylation at a teleost-specific cysteine residue(C946 in LcNLRP3,C1037 in DrNLRP3)was required for the translocation of NLRP3 to the dispersed trans-Golgi network,facilitating its subsequent recruitment to the microtubule-organizing center.This membrane trafficking was crucial for inflammasome assembly and downstream inflammatory responses.These findings provide new insights into the distinct regulatory mechanisms of NLRP3 activation in teleosts,highlighting an evolutionary divergence that contributes to innate immunity adaptation in early vertebrates.
文摘It was widely known that retinoic acid inducible gene I （RIG-I） functions as a cytosolic pattern recognition receptor that initiates innate antiviral immunity by detecting exogenous viral RNAs. However, recent stud- ies showed that RIG-I participates in other various cellular activities by sensing endogenous RNAs under different circumstances. For example, RIG-I facilitates the therapy resistance and expansion of breast cancer cells and promotes T cell-independent B cell activation through interferon signaling activation by recognizing non-coding RNAs and endogenous retroviruses in certain situations. While in hepatocellular carcinoma and acute myeloid leukemia, RIG-I acts as a tumor suppressor through either augmenting STAT1 activation by competitively binding STAT1 against its negative regulator SliP1 or inhibiting AKT-mTOR signaling pathway by directly interacting with Src respectively. These new findings suggest that RIG-I plays more diverse roles in various cellular life activities, such as cell proliferation and differentiation, than previously known. Taken together, the function of RIG-I exceeds far beyond that of a pattern recognition receptor.
基金This work was supported by the National Key Research and Development Program of China(2020YFA0113003,2018YFC1004803)the Natural Science Foundation of China(31630083,82071063)CAMS Innovation Fund for Medical Sciences(2022-I2M-1-012),and the Fundamental Research Funds for the Central Universities.We are grateful to Dr.Min-Xin Guan(Zhejiang University)for valuable suggestions and support,Dr.Yanchun Ji(The Children’s Hospital,Zhejiang University School of Medicine),and Dr.Feilong Meng(The Children’s Hospital,Zhejiang University School of Medicine),and Dr.Juan Du(The First Affiliated Hospital,Zhejiang University School of Medicine)for technical support.
文摘Dear Editor,Inflammatory bowel disease(IBD),a complex syndrome characterized by chronic inflammation of the gastrointestinal tract,is considered a global health problem,especially prevalent in western developed countries and with accelerating incidence in the developing world over the last decade.1 To date,the primary etiology of IBD remains elusive.
