POU transcription factor OCT4 not only plays an essential role in maintaining the pluripotent and self-renewing state of embryonic stem （ES） cells but also acts as a cell fate determinant through a gene dosage effec...POU transcription factor OCT4 not only plays an essential role in maintaining the pluripotent and self-renewing state of embryonic stem （ES） cells but also acts as a cell fate determinant through a gene dosage effect. However, the molecular mechanisms that control the intracellular OCT4 protein level remain elusive. Here, we report that human WWP2, an E3 ubiquitin （Ub）-protein ligase, interacts with OCT4 specifically through its WW domain and enhances Ub modification of OCT4 both in vitro and in vivo. We first demonstrated that endogenous OCT4 in hu- man ES cells can be post-translationally modified by Ub. Furthermore, we found that WWP2 promoted degradation of OCT4 through the 26S proteasome in a dosage-dependent manner, and the active site cysteine residue of WWP2 was required for both its enzymatic activity and proteolytic effect on OCT4. Remarkably, our data show that the en- dogenous OCT4 protein level was significantly elevated when WWP2 expression was downregulated by specific RNA interference （RNAi）, suggesting that WWP2 is an important regulator for maintaining a proper OCT4 protein level in human ES cells. Moreover, northern blot analysis showed that the WWP2 transcript was widely present in diverse human tissues/organs and highly expressed in undifferentiated human ES cells. However, its expression level was quickly decreased after human ES cells differentiated, indicating that WWP2 expression might be developmentally regulated. Our findings demonstrate that WWP2 is an important regulator of the OCT4 protein level in human ES cells.展开更多
Summary： Cancer stem cells （CSCs） are considered responsible for the high recurrence rate in cervical carcinoma. It has been demonstrated that the signal transducer and activator of transcription 3 （STAT3） is inv...Summary： Cancer stem cells （CSCs） are considered responsible for the high recurrence rate in cervical carcinoma. It has been demonstrated that the signal transducer and activator of transcription 3 （STAT3） is involved in the oncogenesis and takes part in mediating the effects of maintaining stem cell phenotype and pluripotency by regulating the expression of stem cell-related transcription factors. However, the correlation between STAT3 and stem cell-related transcription factors in cervical cancer has not been elucidated. In this study, we established overexpressing plasmid （GV316-STAT3） and siRNA-STAT3 for transfecting Siha cells. Cells negative or positive for Nanog, Oct4, or Sox2 were selected by flow cytometry. Proliferation and differentiation rate of Siha cells was determined by detecting the efficiency of tumor sphere formation. The expression of Nanog, Oct4 and Sox2 （cancer stem cell markers） and STAT3 was detected by quantitative real-time PCR and immunoblotting for Siha cells and by immuno- histochemistry （IHC） for cervical tissues, respectively. The results showed that Nanog＋, Oct4＋, and Sox2＋ Siha-STAT3 over-expressing cells displayed the typical non-adherent spheres. The sphere for- mation efficiency was significantly different between Siha-STAT3 overexpressing cells and siRNA-STAT3 cells （P〈0.05）. Meanwhile, the expression levels of Oct4, Nanog and Sox2 rrtRNA and protein were significantly higher in Siha-STAT3 overexprssing cells than in siRNA-STAT3 cells （P〈0.05）. In addition, the positive rate of STAT3, Nanog, Oct4 and Sox2 in cervical cancer tissues was higher than that in chronic cervicitis group （P〈0.05）. There was a significantly positive relationship between STAT3 and Nanog or Oct4 or Sox2 expression （all P〈0.001）. These results suggested that Oct4＋, Sox2＋, and Nanog＋ cell population possesses stem cell properties in cervical cancer, which may contribute to cervical carcinogenesis and be regulated by STAT3.展开更多
BACKGROUND Heart diseases are the primary cause of death all over the world.Following myocardial infarction,billions of cells die,resulting in a huge loss of cardiac function.Stem cell-based therapies have appeared as...BACKGROUND Heart diseases are the primary cause of death all over the world.Following myocardial infarction,billions of cells die,resulting in a huge loss of cardiac function.Stem cell-based therapies have appeared as a new area to support heart regeneration.The transcription factors GATA binding protein 4(GATA-4)and myocyte enhancer factor 2C(MEF2C)are considered prominent factors in the development of the cardiovascular system.AIM To explore the potential of GATA-4 and MEF2C for the cardiac differentiation of human umbilical cord mesenchymal stem cells(hUC-MSCs).METHODS hUC-MSCs were characterized morphologically and immunologically by the presence of specific markers of MSCs via immunocytochemistry and flow cytometry,and by their potential to differentiate into osteocytes and adipocytes.hUC-MSCs were transfected with GATA-4,MEF2C,and their combination to direct the differentiation.Cardiac differentiation was confirmed by semiquant itative real-time polymerase chain reaction and immunocytochemistry.RESULTS hUC-MSCs expressed specific cell surface markers CD105,CD90,CD44,and vimentin but lack the expression of CD45.The transcription factors GATA-4 and MEF2C,and their combination induced differentiation in hUC-MSCs with significant expression of cardiac genes i.e.,GATA-4,MEF2C,NK2 homeobox 5(NKX2.5),MHC,and connexin-43,and cardiac proteins GATA-4,NKX2.5,cardiac troponin T,and connexin-43.CONCLUSION Transfection with GATA-4,MEF2C,and their combination effectively induces cardiac differentiation in hUC-MSCs.These genetically modified MSCs could be a promising treatment option for heart diseases in the future.展开更多
Crohn’s disease may prinicipally involve the whole gastrointestinal tract. Most commonly, the inflammation occurs in the small intestine and/or in the colon with stable disease location over the years. The pathogenes...Crohn’s disease may prinicipally involve the whole gastrointestinal tract. Most commonly, the inflammation occurs in the small intestine and/or in the colon with stable disease location over the years. The pathogenesis of both disease phenotypes is complex, the likely primary defect lies in the innate rather than adaptive immunity, particularly in the chemical antimicrobial barrier of the mucosa. Crohn’s ileitis is associated with a reduced expression of the Wnt signalling pathway transcription factor T-cell factor 4 (TCF4), which is regulating Paneth cell differentiation. As a result, the alpha-defensins and principal Paneth cell products HD5 and HD6 are deficiently expressed in ileal disease, independent of current inflammation. In contrast, Crohn’s colitis is typically associated with an impaired induction of the beta-defensins HBD2 and HBD3 caused by fewer gene copy numbers in the gene locus of the beta-defensins on chromosome 8. This ileal and colonic defect in innate defence mediated by a deficiency of the protective alpha- and beta- defensins may enable the luminal microbes to invade the mucosa and trigger the inflammation. A better understanding of the exact molecular mechanisms behind ileal and colonic Crohn’s disease may give rise to new therapeutic strategies based on a stimulation of the protective innate immune system.展开更多
Non-coding RNAs(nc RNAs),such as micro RNAs and large intergenic non-coding RNAs,have been shown to play essential roles in regulating pluripotency.Yet,it is not clear the role of natural antisense transcripts(NATs),a...Non-coding RNAs(nc RNAs),such as micro RNAs and large intergenic non-coding RNAs,have been shown to play essential roles in regulating pluripotency.Yet,it is not clear the role of natural antisense transcripts(NATs),also belonging to nc RNAs,in embryonic stem cells.However,the role of NATs in embryonic stem cells remains unknown.We further confirmed the expression of the NATs of three key pluripotency genes,Oct4,Nanog and Sox2.Moreover,overexpression of Sox2-NAT reduces the expression of Sox2 protein,and slightly enhances the Sox2 m RNA level.Altogether,our data indicated that like other nc RNAs,NATs might be involved in pluripotency maintenance.展开更多
Oral squamous cell carcinoma(OSCC),a common malignancy of the head and neck,ranks sixth worldwide in terms of cancers with the most negative impact,owing to tumor relapse rates,cervical lymphnode metastasis,and the la...Oral squamous cell carcinoma(OSCC),a common malignancy of the head and neck,ranks sixth worldwide in terms of cancers with the most negative impact,owing to tumor relapse rates,cervical lymphnode metastasis,and the lack of an efficacious systemic therapy.Its prognosis is poor,and its mortality rate is high.Octamer-binding transcription factor 4(OCT4)is a member of the Pit-Oct-Unc(POU)family and is a key reprogramming factor that produces a marked effect in preserving the pluripotency and self-renewal state of embryonic stem cells(ESCs).According to recent studies,OCT4 participates in retaining the survival of OSCC cancer stem cells(CSCs),which has far-reaching implications for the occurrence,recurrence,metastasis,and prognosis of oral carcinogenesis.Therefore,we summarize the structure,subtypes,and function of OCT4 as well as its role in the occurrence,progression,and prognosis of OSCC.展开更多
基金Acknowledgments We are grateful to Dr DA Melton （Harvard University） for shar- ing his human ES cells with us. The study was supported by grants from the National High Technology Research and Development Program of China （2006CB943900）, the National Natural Science Foundation of China （General Program, 30500088）, the Shang- hai Jiao Tong University School of Medicine, and the Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. The study was also supported by the Shanghai Leading Academic Deciline Project （S30201）.
文摘POU transcription factor OCT4 not only plays an essential role in maintaining the pluripotent and self-renewing state of embryonic stem （ES） cells but also acts as a cell fate determinant through a gene dosage effect. However, the molecular mechanisms that control the intracellular OCT4 protein level remain elusive. Here, we report that human WWP2, an E3 ubiquitin （Ub）-protein ligase, interacts with OCT4 specifically through its WW domain and enhances Ub modification of OCT4 both in vitro and in vivo. We first demonstrated that endogenous OCT4 in hu- man ES cells can be post-translationally modified by Ub. Furthermore, we found that WWP2 promoted degradation of OCT4 through the 26S proteasome in a dosage-dependent manner, and the active site cysteine residue of WWP2 was required for both its enzymatic activity and proteolytic effect on OCT4. Remarkably, our data show that the en- dogenous OCT4 protein level was significantly elevated when WWP2 expression was downregulated by specific RNA interference （RNAi）, suggesting that WWP2 is an important regulator for maintaining a proper OCT4 protein level in human ES cells. Moreover, northern blot analysis showed that the WWP2 transcript was widely present in diverse human tissues/organs and highly expressed in undifferentiated human ES cells. However, its expression level was quickly decreased after human ES cells differentiated, indicating that WWP2 expression might be developmentally regulated. Our findings demonstrate that WWP2 is an important regulator of the OCT4 protein level in human ES cells.
基金supported by the National Natural Science Foundation of China(No.81272866)the Wuhan Municipal Science and Technology Bureau Foundation of China(No.20146 0101010043)
文摘Summary： Cancer stem cells （CSCs） are considered responsible for the high recurrence rate in cervical carcinoma. It has been demonstrated that the signal transducer and activator of transcription 3 （STAT3） is involved in the oncogenesis and takes part in mediating the effects of maintaining stem cell phenotype and pluripotency by regulating the expression of stem cell-related transcription factors. However, the correlation between STAT3 and stem cell-related transcription factors in cervical cancer has not been elucidated. In this study, we established overexpressing plasmid （GV316-STAT3） and siRNA-STAT3 for transfecting Siha cells. Cells negative or positive for Nanog, Oct4, or Sox2 were selected by flow cytometry. Proliferation and differentiation rate of Siha cells was determined by detecting the efficiency of tumor sphere formation. The expression of Nanog, Oct4 and Sox2 （cancer stem cell markers） and STAT3 was detected by quantitative real-time PCR and immunoblotting for Siha cells and by immuno- histochemistry （IHC） for cervical tissues, respectively. The results showed that Nanog＋, Oct4＋, and Sox2＋ Siha-STAT3 over-expressing cells displayed the typical non-adherent spheres. The sphere for- mation efficiency was significantly different between Siha-STAT3 overexpressing cells and siRNA-STAT3 cells （P〈0.05）. Meanwhile, the expression levels of Oct4, Nanog and Sox2 rrtRNA and protein were significantly higher in Siha-STAT3 overexprssing cells than in siRNA-STAT3 cells （P〈0.05）. In addition, the positive rate of STAT3, Nanog, Oct4 and Sox2 in cervical cancer tissues was higher than that in chronic cervicitis group （P〈0.05）. There was a significantly positive relationship between STAT3 and Nanog or Oct4 or Sox2 expression （all P〈0.001）. These results suggested that Oct4＋, Sox2＋, and Nanog＋ cell population possesses stem cell properties in cervical cancer, which may contribute to cervical carcinogenesis and be regulated by STAT3.
基金Supported by the Higher Education Commission(HEC),Pakistan Scholarship for Ph.D.Studies to Razzaq SS,No.520-148390-2BS6-011.
文摘BACKGROUND Heart diseases are the primary cause of death all over the world.Following myocardial infarction,billions of cells die,resulting in a huge loss of cardiac function.Stem cell-based therapies have appeared as a new area to support heart regeneration.The transcription factors GATA binding protein 4(GATA-4)and myocyte enhancer factor 2C(MEF2C)are considered prominent factors in the development of the cardiovascular system.AIM To explore the potential of GATA-4 and MEF2C for the cardiac differentiation of human umbilical cord mesenchymal stem cells(hUC-MSCs).METHODS hUC-MSCs were characterized morphologically and immunologically by the presence of specific markers of MSCs via immunocytochemistry and flow cytometry,and by their potential to differentiate into osteocytes and adipocytes.hUC-MSCs were transfected with GATA-4,MEF2C,and their combination to direct the differentiation.Cardiac differentiation was confirmed by semiquant itative real-time polymerase chain reaction and immunocytochemistry.RESULTS hUC-MSCs expressed specific cell surface markers CD105,CD90,CD44,and vimentin but lack the expression of CD45.The transcription factors GATA-4 and MEF2C,and their combination induced differentiation in hUC-MSCs with significant expression of cardiac genes i.e.,GATA-4,MEF2C,NK2 homeobox 5(NKX2.5),MHC,and connexin-43,and cardiac proteins GATA-4,NKX2.5,cardiac troponin T,and connexin-43.CONCLUSION Transfection with GATA-4,MEF2C,and their combination effectively induces cardiac differentiation in hUC-MSCs.These genetically modified MSCs could be a promising treatment option for heart diseases in the future.
基金The Robert Bosch Foundation, Stuttgart, Germany the Emmy Noether program (J.W.) of the Deutsche Forschungsgemeinschaft (DFG)
文摘Crohn’s disease may prinicipally involve the whole gastrointestinal tract. Most commonly, the inflammation occurs in the small intestine and/or in the colon with stable disease location over the years. The pathogenesis of both disease phenotypes is complex, the likely primary defect lies in the innate rather than adaptive immunity, particularly in the chemical antimicrobial barrier of the mucosa. Crohn’s ileitis is associated with a reduced expression of the Wnt signalling pathway transcription factor T-cell factor 4 (TCF4), which is regulating Paneth cell differentiation. As a result, the alpha-defensins and principal Paneth cell products HD5 and HD6 are deficiently expressed in ileal disease, independent of current inflammation. In contrast, Crohn’s colitis is typically associated with an impaired induction of the beta-defensins HBD2 and HBD3 caused by fewer gene copy numbers in the gene locus of the beta-defensins on chromosome 8. This ileal and colonic defect in innate defence mediated by a deficiency of the protective alpha- and beta- defensins may enable the luminal microbes to invade the mucosa and trigger the inflammation. A better understanding of the exact molecular mechanisms behind ileal and colonic Crohn’s disease may give rise to new therapeutic strategies based on a stimulation of the protective innate immune system.
基金supported by the National Natural Science Foundation of China(31271547)the Natural Science Foundation of Tianjin,China(14JYBJC23600)+3 种基金the National Key Basic Research and Development Program of China(2010CB833603)the Program for New Century Excellent Talents(NCET-13-0293)the 111 Project Grant(B08011)the Funds for National Basic Science Personnel Training(J1103503)
文摘Non-coding RNAs(nc RNAs),such as micro RNAs and large intergenic non-coding RNAs,have been shown to play essential roles in regulating pluripotency.Yet,it is not clear the role of natural antisense transcripts(NATs),also belonging to nc RNAs,in embryonic stem cells.However,the role of NATs in embryonic stem cells remains unknown.We further confirmed the expression of the NATs of three key pluripotency genes,Oct4,Nanog and Sox2.Moreover,overexpression of Sox2-NAT reduces the expression of Sox2 protein,and slightly enhances the Sox2 m RNA level.Altogether,our data indicated that like other nc RNAs,NATs might be involved in pluripotency maintenance.
基金supported by the Health Commission of Zhejiang Province(No.2022RC027),China。
文摘Oral squamous cell carcinoma(OSCC),a common malignancy of the head and neck,ranks sixth worldwide in terms of cancers with the most negative impact,owing to tumor relapse rates,cervical lymphnode metastasis,and the lack of an efficacious systemic therapy.Its prognosis is poor,and its mortality rate is high.Octamer-binding transcription factor 4(OCT4)is a member of the Pit-Oct-Unc(POU)family and is a key reprogramming factor that produces a marked effect in preserving the pluripotency and self-renewal state of embryonic stem cells(ESCs).According to recent studies,OCT4 participates in retaining the survival of OSCC cancer stem cells(CSCs),which has far-reaching implications for the occurrence,recurrence,metastasis,and prognosis of oral carcinogenesis.Therefore,we summarize the structure,subtypes,and function of OCT4 as well as its role in the occurrence,progression,and prognosis of OSCC.
