The cochlear auditory epithelium contains two types of sound receptors,inner hair cells(IHCs)and outer hair cells(OHCs).Mouse models for labelling juvenile and adult IHCs or OHCs exist;however,labelling for embryonic ...The cochlear auditory epithelium contains two types of sound receptors,inner hair cells(IHCs)and outer hair cells(OHCs).Mouse models for labelling juvenile and adult IHCs or OHCs exist;however,labelling for embryonic and perinatal IHCs or OHCs are lacking.Here,we generated a new knock-in Fgf8^(P2A-3×GFP/+)(Fgf8^(GFP)/+)strain,in which the expression of a series of three GFP fragments is controlled by endogenous Fgf8 cis-regulatory elements.After confirming that GFP expression accurately reflects the expression of Fgf8,we successfully obtained both embryonic and neonatal IHCs with high purity,highlighting the power of Fgf8^(GFP)/+.Furthermore,our fate-mapping analysis revealed,unexpectedly,that IHCs are also derived from inner ear progenitors expressing Insm1,which is currently regarded as an OHC marker.Thus,besides serving as a highly favorable tool for sorting early IHCs,Fgf8^(GFP)/+will facilitate the isolation of pure early OHCs by excluding IHCs from the entire hair cell pool.展开更多
The developing human and mouse teeth constitute an ideal model system to study the regulatory mechanism underlying organ growth control since their teeth share highly conserved and well-characterized developmental pro...The developing human and mouse teeth constitute an ideal model system to study the regulatory mechanism underlying organ growth control since their teeth share highly conserved and well-characterized developmental processes, and their developmental tempo varies notably. In the current study, we manipulated heterogenous recombination between human and mouse dental tissues and demonstrated that the dental mesenchyme dominates the tooth developmental tempo and FGF8 could be a critical player during this developmental process. Forced activation of FGF8 signaling in the dental mesenchyme of mice promoted cell proliferation, prevented cell apoptosis via p38 and perhaps PI3 K-Akt intracellular signaling,and impelled the transition of the cell cycle from G1-to S-phase in the tooth germ, resulting in the slowdown of the tooth developmental pace. Our results provide compelling evidence that extrinsic signals can profoundly affect tooth developmental tempo, and the dental mesenchymal FGF8 could be a pivotal factor in controlling the developmental pace in a non-cell-autonomous manner during mammalian odontogenesis.展开更多
The cranial neural crest(CNC)cells play a vital role in craniofacial development and regeneration.They are multi-potent progenitors,being able to differentiate into various types of tissues.Both pre-migratory and post...The cranial neural crest(CNC)cells play a vital role in craniofacial development and regeneration.They are multi-potent progenitors,being able to differentiate into various types of tissues.Both pre-migratory and post-migratory CNC cells are plastic,taking on diverse fates by responding to different inductive signals.However,what sustains the multipotency ofCNCcells andderivatives remains largely unknown.In this study,we present evidence that FGF8 signaling is able to sustain progenitor status and multipotency of CNC-derived mesenchymal cells both in vivo and in vitro.We show that augmented FGF8 signaling in pre-migratory CNC cells prevents cell differentiation and organogenesis in the craniofacial region by maintaining their progenitor status.CNC-derived mesenchymal cells with Fgf8 overexpression or control cells in the presence of exogenous FGF8 exhibit prolonged survival,proliferation,and multi-potent differentiation capability in cell cultures.Remarkably,exogenous FGF8 also sustains the capability of CNC-derived mesenchymal cells to participate in organogenesis such as odontogenesis.Furthermore,FGF8-mediated signaling strongly promotes adipogenesis but inhibits osteogenesis of CNC-derived mesenchymal cells in vitro.Our results reveal a specific role for FGF8 in the maintenance of progenitor status and in fate determination of CNC cells,implicating a potential application in expansion and fate manipulation of CNC-derived cells in stem cell-based craniofacial regeneration.展开更多
The aim of this study was to explore the regulatory mechanism of retinoic acid(RA)on the TBX1 gene expression in myocardial cells.Ventricular cardio-cytes were isolated from neonatal rats and cultured,and then treated...The aim of this study was to explore the regulatory mechanism of retinoic acid(RA)on the TBX1 gene expression in myocardial cells.Ventricular cardio-cytes were isolated from neonatal rats and cultured,and then treated with different concentrations of retinoic acid.The expression of Shh and Fgf8 at mRNA and protein levels in neonatal rat myocardial cells were measured by using RT-PCR and Western blot technique,respectively.There was basal expression of Shh and Fgf8 in the control group.When treated with 3�10–7 mol/L RA,we observed that the expression of Shh mRNA and protein in neonatal rat myocardial cells were up-regulated by 1.51(P<0.05)and 1.10 times(P<0.05),respectively.In comparison with the control group,under the concentra-tion of 5�10–7 mol/L RA,they were up-regulated by 2.21(P<0.05)and 2.38 times(P<0.05)individually.Mean-while,we could detect that the expression of Fgf8 mRNA and protein were up-regulated by 2.50 times(P<0.05)and 80%(P<0.05)separately compared with the control group after stimulation of 3�10–7 mol/L RA,and they were up-regulated by 3.48(P<0.05)and 2.04 times(P<0.05)individually after stimulation of 5�10–7 mol/L RA.The results indicated that RA could induce the expression of Shh and Fgf8 in neonatal rat myocardial cells.At the same time,it has shown that Shh and Fgf8 were involved in the regulation process of RA on TBX1 expression.展开更多
基金funded by the National Key R&D Program of China(2021YFA1101804)the Strategic Priority Research Program of the Chinese Academy of Science(XDB32060100)+3 种基金the National Natural Science Foundation of China(91949119,82101212,and 82101209)a Shanghai Municipal Science and Technology Major Project(2018SHZDZX05)the Science and Technology Commission of Shanghai Municipality(21ZR1440200)the Shanghai Sailing Program(20YF1426400).
文摘The cochlear auditory epithelium contains two types of sound receptors,inner hair cells(IHCs)and outer hair cells(OHCs).Mouse models for labelling juvenile and adult IHCs or OHCs exist;however,labelling for embryonic and perinatal IHCs or OHCs are lacking.Here,we generated a new knock-in Fgf8^(P2A-3×GFP/+)(Fgf8^(GFP)/+)strain,in which the expression of a series of three GFP fragments is controlled by endogenous Fgf8 cis-regulatory elements.After confirming that GFP expression accurately reflects the expression of Fgf8,we successfully obtained both embryonic and neonatal IHCs with high purity,highlighting the power of Fgf8^(GFP)/+.Furthermore,our fate-mapping analysis revealed,unexpectedly,that IHCs are also derived from inner ear progenitors expressing Insm1,which is currently regarded as an OHC marker.Thus,besides serving as a highly favorable tool for sorting early IHCs,Fgf8^(GFP)/+will facilitate the isolation of pure early OHCs by excluding IHCs from the entire hair cell pool.
基金supported by the National Natural Science Foundation of China (81870739, 82001002, 81271102, 81771034)the Natural Science Foundation of Fujian Province (2019J01281, 2020J01180)。
文摘The developing human and mouse teeth constitute an ideal model system to study the regulatory mechanism underlying organ growth control since their teeth share highly conserved and well-characterized developmental processes, and their developmental tempo varies notably. In the current study, we manipulated heterogenous recombination between human and mouse dental tissues and demonstrated that the dental mesenchyme dominates the tooth developmental tempo and FGF8 could be a critical player during this developmental process. Forced activation of FGF8 signaling in the dental mesenchyme of mice promoted cell proliferation, prevented cell apoptosis via p38 and perhaps PI3 K-Akt intracellular signaling,and impelled the transition of the cell cycle from G1-to S-phase in the tooth germ, resulting in the slowdown of the tooth developmental pace. Our results provide compelling evidence that extrinsic signals can profoundly affect tooth developmental tempo, and the dental mesenchymal FGF8 could be a pivotal factor in controlling the developmental pace in a non-cell-autonomous manner during mammalian odontogenesis.
基金This work was supported by the National Institutes of Health(R01DE24152 and R01DE14044 to Y.C.)the National Basic Research Program of China(2010CB944800)to W.T.the National Natural Science Foundation of China(81371134)to T.H.
文摘The cranial neural crest(CNC)cells play a vital role in craniofacial development and regeneration.They are multi-potent progenitors,being able to differentiate into various types of tissues.Both pre-migratory and post-migratory CNC cells are plastic,taking on diverse fates by responding to different inductive signals.However,what sustains the multipotency ofCNCcells andderivatives remains largely unknown.In this study,we present evidence that FGF8 signaling is able to sustain progenitor status and multipotency of CNC-derived mesenchymal cells both in vivo and in vitro.We show that augmented FGF8 signaling in pre-migratory CNC cells prevents cell differentiation and organogenesis in the craniofacial region by maintaining their progenitor status.CNC-derived mesenchymal cells with Fgf8 overexpression or control cells in the presence of exogenous FGF8 exhibit prolonged survival,proliferation,and multi-potent differentiation capability in cell cultures.Remarkably,exogenous FGF8 also sustains the capability of CNC-derived mesenchymal cells to participate in organogenesis such as odontogenesis.Furthermore,FGF8-mediated signaling strongly promotes adipogenesis but inhibits osteogenesis of CNC-derived mesenchymal cells in vitro.Our results reveal a specific role for FGF8 in the maintenance of progenitor status and in fate determination of CNC cells,implicating a potential application in expansion and fate manipulation of CNC-derived cells in stem cell-based craniofacial regeneration.
基金supported by the National Natural Science Foundation of China(Grant No.30400484).
文摘The aim of this study was to explore the regulatory mechanism of retinoic acid(RA)on the TBX1 gene expression in myocardial cells.Ventricular cardio-cytes were isolated from neonatal rats and cultured,and then treated with different concentrations of retinoic acid.The expression of Shh and Fgf8 at mRNA and protein levels in neonatal rat myocardial cells were measured by using RT-PCR and Western blot technique,respectively.There was basal expression of Shh and Fgf8 in the control group.When treated with 3�10–7 mol/L RA,we observed that the expression of Shh mRNA and protein in neonatal rat myocardial cells were up-regulated by 1.51(P<0.05)and 1.10 times(P<0.05),respectively.In comparison with the control group,under the concentra-tion of 5�10–7 mol/L RA,they were up-regulated by 2.21(P<0.05)and 2.38 times(P<0.05)individually.Mean-while,we could detect that the expression of Fgf8 mRNA and protein were up-regulated by 2.50 times(P<0.05)and 80%(P<0.05)separately compared with the control group after stimulation of 3�10–7 mol/L RA,and they were up-regulated by 3.48(P<0.05)and 2.04 times(P<0.05)individually after stimulation of 5�10–7 mol/L RA.The results indicated that RA could induce the expression of Shh and Fgf8 in neonatal rat myocardial cells.At the same time,it has shown that Shh and Fgf8 were involved in the regulation process of RA on TBX1 expression.
