Radiation-induced brain injury remains one of the most severe complications of radiotherapy for head and neck tumors,with limited options for prevention and treatment.In situ neural regeneration technology has demonst...Radiation-induced brain injury remains one of the most severe complications of radiotherapy for head and neck tumors,with limited options for prevention and treatment.In situ neural regeneration technology has demonstrated promising therapeutic effects in various neurodegenerative and neurotrauma conditions.In this study,we overexpressed the neural transcription factor NeuroD1 using in situ neural regeneration technology in a radiation-induced brain injury mouse model.This approach converted reactive astrocytes into neurons,increased neuronal density,protected endogenous neurons,decreased microglial activation,reduced peripheral CD8+T cell infiltration,and diminished angiogenesis in the injured area,leading to a significant reduction in lesion volume.Additionally,we explored the potential mechanisms of NeuroD1 in situ neural regeneration technology through bulk RNA sequencing,which showed an upregulation of neurogenesis-related genes and a downregulation of immune response-related and angiogenesis-related genes.Furthermore,our findings suggested that NeuroD1 in situ neural regeneration technology converted reactive astrocytes into neurons and reduced microglial activation in a thalamic hemorrhagic stroke mouse model.In summary,this study supports NeuroD1 in situ neural regeneration technology as a potential therapeutic approach for treating radiation-induced brain injury and hemorrhagic stroke,and offers new insights into the therapeutic role of NeuroD1 in delayed brain injury.展开更多
Transcription factor-mediated cell conversion has been reported in the central nervous system of both rodents and nonhuman primates.In particular,glia-to-neuron conversion has been achieved in the brain and spinal cor...Transcription factor-mediated cell conversion has been reported in the central nervous system of both rodents and nonhuman primates.In particular,glia-to-neuron conversion has been achieved in the brain and spinal cord of animal models for neural regeneration and repair.However,whether glia-to-neuron conversion can be used for brain repair in humans needs to be explored.To investigate the use of glia-to-neuron conversion technology in the human brain,we established a long-term ex vivo culture system using human brain tissue that was surgically removed from epileptic patients to test glia-to-neuron conversion directly.We found that neural transcription factors NeuroD1 and Ascl1 both converted human glial cells into neurons.Immunostaining and electrophysiological recordings showed that the glia-converted neurons demonstrated immature properties during the initial 7-14 days of conversion,and then acquired more mature neuronal properties after 21-27 days of conversion.These ex vivo conversion studies in human brain tissue pave the way toward future clinical trials using a transcription factor-based glia-to-neuron conversion approach to treat neurological disorders.展开更多
Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders....Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.展开更多
A new technology called in vivo glia-to-neuron conversion has emerged in recent years as a promising next generation therapy for neural regeneration and repair. This is achieved through reprogramming endogenous glial ...A new technology called in vivo glia-to-neuron conversion has emerged in recent years as a promising next generation therapy for neural regeneration and repair. This is achieved through reprogramming endogenous glial cells into neurons in the central nervous system through ectopically expressing neural transcriptional factors in glial cells. Previous studies have been focusing on glial cells in the grey matter such as the cortex and striatum, but whether glial cells in the white matter can be reprogrammed or not is unknown. To address this fundamental question, we express NeuroD1 in the astrocytes of both grey matter(cortex and striatum) and white matter(corpus callosum) to investigate the conversion efficiency, neuronal subtypes, and electrophysiological features of the converted neurons. We discover that NeuroD1 can efficiently reprogram the astrocytes in the grey matter into functional neurons, but the astrocytes in the white matter are much resistant to neuronal reprogramming. The converted neurons from cortical and striatal astrocytes are composed of both glutamatergic and GABAergic neurons, capable of firing action potentials and having spontaneous synaptic activities. In contrast, the few astrocyte-converted neurons in the white matter are rather immature with rare synaptic events. These results provide novel insights into the differential reprogramming capability between the astrocytes in the grey matter versus the white matter, and highlight the impact of regional astrocytes as well as microenvironment on the outcome of glia-toneuron conversion. Since human brain has large volume of white matter, this study will provide important guidance for future development of in vivo glia-to-neuron conversion technology into potential clinical therapies. Experimental protocols in this study were approved by the Laboratory Animal Ethics Committee of Jinan University(approval No. IACUC-20180321-03) on March 21, 2018.展开更多
The onset of retinal degenerative disease is often associated with neuronal loss. Therefore, how to regenerate new neurons to restore vision is an important issue. NeuroD1 is a neural transcription factor with the abi...The onset of retinal degenerative disease is often associated with neuronal loss. Therefore, how to regenerate new neurons to restore vision is an important issue. NeuroD1 is a neural transcription factor with the ability to reprogram brain astrocytes into neurons in vivo. Here, we demonstrate that in adult mice, NeuroD1 can reprogram Müller cells, the principal glial cell type in the retina, to become retinal neurons. Most strikingly, ectopic expression of NeuroD1 using two different viral vectors converted Müller cells into different cell types. Specifically, AAV7 m8 GFAP681::GFP-ND1 converted Müller cells into inner retinal neurons, including amacrine cells and ganglion cells. In contrast, AAV9 GFAP104::ND1-GFP converted Müller cells into outer retinal neurons such as photoreceptors and horizontal cells, with higher conversion efficiency. Furthermore, we demonstrate that Müller cell conversion induced by AAV9 GFAP104::ND1-GFP displayed clear dose-and time-dependence. These results indicate that Müller cells in adult mice are highly plastic and can be reprogrammed into various subtypes of retinal neurons.展开更多
目的·筛查青少年的成人起病型糖尿病(maturity-onset diabetes of the young,MODY)家系中NEUROD1基因突变,分析突变与中国人MODY6发病的相关性及其潜在的致病机制。方法·采用PCR-直接测序法对96例GCK/MODY2、HNF1A/MODY3、HNF...目的·筛查青少年的成人起病型糖尿病(maturity-onset diabetes of the young,MODY)家系中NEUROD1基因突变,分析突变与中国人MODY6发病的相关性及其潜在的致病机制。方法·采用PCR-直接测序法对96例GCK/MODY2、HNF1A/MODY3、HNF1B/MODY5突变阴性的中国MODY先证者进行NEUROD1突变筛查,同时比较96例MODY先证者与100例非糖尿病对照者NEUROD1基因变异的基因型频率。采用从头建模法构建NEUROD1蛋白野生型和突变体的3D结构,采用双荧光素酶报告基因系统检测野生型和突变体蛋白对胰岛素基因转录活性的影响。结果·在一个MODY家系中发现NEUROD1基因杂合错义突变Glu59Gln (NM_002500.5,c.175G>C)。3D结构分析发现,该突变将野生型中带负电荷的Glu59转化为突变中不带电荷的Gln59,导致两个盐桥键Glu59-Arg54和Glu59-Lys88缺失,并形成一个新的氢键Gln59-Arg54。与野生型相比,Glu59Gln突变体的胰岛素基因转录活性下降36.3%(P<0.05)。与非糖尿病对照相比,96例MODY先证者中Ala45Thr (G-A)变异的AA+GA基因型频率显著升高(P=0.002)。结论·Glu59Gln突变改变了NEUROD1蛋白N端的分子构象,导致其胰岛素基因转录活性显著下降,是该家系突变携带者胰岛素分泌缺陷的原因。Ala45Thr变异与MODY6先证者糖尿病发病年龄的提前有关。展开更多
Optic nerve injury leads to axonal degeneration and the death of retinal ganglion cells,which ultimately causes vision loss.Notably,current treatments are limited.In the present study,we explored whether neurogenic di...Optic nerve injury leads to axonal degeneration and the death of retinal ganglion cells,which ultimately causes vision loss.Notably,current treatments are limited.In the present study,we explored whether neurogenic differentiation factor 1(NeuroD1 or ND1)overexpression in retinal Müller cells may repair the retina after optic nerve crush in mice.Adult mice were subjected to optic nerve crush followed by intravitreal AAV-7m8-GFAP-GFP-ND1 virus injection.Immunofluorescent staining,multi-electrode array recording,electroretinogram,and visual behavior tests were then performed to examine retinal and optic nerve structure and retinal function at various post-optic nerve crush and virus injection times.Western blot analysis and quantitative reverse transcription polymerase chain reaction were performed to explore the possible mechanisms.Compared with the control virus,specific overexpression of ND1 in Müller cells greatly improved the light responses of retinal ganglion cells and retinal neurons in optic nerve crush-injured mice as early as 1-2 weeks post-virus injection and lasted for up to 4 weeks.Neuronal survival in the ganglion cell layer and synaptic connections in the inner retina were slightly improved at 2 weeks;however,visual behavior,retinal ganglion cell survival,and optic nerve structure were not improved.ND1 transiently enhanced glial cell-derived neurotrophic factor expression in the optic nerve crush-injured retina but hardly inhibited retinal inflammation within 2 weeks.Together,our data indicate that ND1 overexpression in Müller cells improves retinal function in the optic nerve crush-injured retina,and suggest that its neuroprotective effect may be caused by enhanced glial cell-derived neurotrophic factor release.展开更多
Objective::In contrast to the most commonly reported forms of maturity-onset diabetes of the young(MODY),including MODY2,MODY3 and MODY5,MODY6 is a relatively rare subtype.To investigate whether NEUROD1 is responsible...Objective::In contrast to the most commonly reported forms of maturity-onset diabetes of the young(MODY),including MODY2,MODY3 and MODY5,MODY6 is a relatively rare subtype.To investigate whether NEUROD1 is responsible for MODY in Chinese individuals,we screened its mutations in MODY pedigrees and explored the potential pathogenic mechanisms.Methods::Polymerase chain reaction direct sequencing was performed to screen NEUROD1 mutations in 32 Chinese MODY probands who were negative for the GCK/MODY2,HNF1A/MODY3 and HNF1B/MODY5 genes in this observational study.In addition,we enrolled 201 unrelated,non-diabetic control subjects of Han Chinese descent.The functional significance of newly identified mutations was analyzed using clinical phenotype,pathophysiology and three-dimensional structure studies.This study was approved by the Institutional Review Board of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital,China(approval No.YS-2017-83)on March 3,2017.Results::E59Q(c.175 G>C,p.Glu59Gln),a heterozygous missense mutation in the NEUROD1 gene,was identified in one family with MODY.The Glu59 residue in NeuroD1 is highly conserved across mammalian species.Four diabetic patients carrying the mutation(a proband and her son,brother and sister)were lean,with a body mass index of 20.9(20.3-21.2)kg/m 2.Compared with their unaffected relatives(n=4),E59Q carriers(n=4)had significantly decreased ratios of fasting and 2-hour insulin to plasma glucose(both fasting plasma insulin/fasting plasma glucose and 2-hour postprandial plasma insulin/2-hour postprandial plasma glucose,P<0.005).The proband’s father had an E59Q mutation and normal glucose tolerance,which suggested non-penetrance.The E59Q mutation was not detected in other probands or in the 201 control subjects with normal glucose tolerance.Two salt-bridge bonds of Glu59 were disrupted at the Q59 mutation site.Conclusion::The NEUROD1-E59Q mutation changed the molecular conformation of the N-terminal in NeuroD1,which may decrease binding of the E59Q mutant to the insulin promoter and insulin gene transcription activity,therefore causing the MODY6 subtype with defective insulin secretion.展开更多
1文献来源研究一:Rudin CM,Poirier JT,Byers LA,et al.Molecular subtypes of small cell lung cancer:A synthesis of human and mouse model data[J].Nat Rev Cancer,2019,19(5):289-297.研究二:Owonikoko TK,Dwivedi B,Chen ZJ,et a...1文献来源研究一:Rudin CM,Poirier JT,Byers LA,et al.Molecular subtypes of small cell lung cancer:A synthesis of human and mouse model data[J].Nat Rev Cancer,2019,19(5):289-297.研究二:Owonikoko TK,Dwivedi B,Chen ZJ,et al.YAP1 positive small-cell lung cancer subtype is associated with the T-cell inflamed gene expression profile and confers good prognosis and long term survival[J].J Clin Oncol,2020,38(15S):Abstr 9019.展开更多
基金the National Natural Science Foundation of China,Nos.81925031(to YT)82330099(to YT)+7 种基金82404189(to KZ)the Key-Area Research and Development Program of Guangdong Province,No.2023B0303040003(to YT)STI 2030-Major Projects,No.2022ZD0211603(to YT)Guangzhou Key Projects of Brain Science and Brain-Like Intelligence Technology,No.202206060002(to GC and YS)Science and Technology Project of Guangdong Province,No.2018B030332001(to GC)Guangdong Provincial Pearl River Project,No.2021ZT09Y552(to GC)the Guangdong Basic and Applied Basic Research Foundation,No.2022A1515110189(to KZ)Sun Yat-sen Pilot Scientific Research Fund,No.YXQH202427(to KZ).
文摘Radiation-induced brain injury remains one of the most severe complications of radiotherapy for head and neck tumors,with limited options for prevention and treatment.In situ neural regeneration technology has demonstrated promising therapeutic effects in various neurodegenerative and neurotrauma conditions.In this study,we overexpressed the neural transcription factor NeuroD1 using in situ neural regeneration technology in a radiation-induced brain injury mouse model.This approach converted reactive astrocytes into neurons,increased neuronal density,protected endogenous neurons,decreased microglial activation,reduced peripheral CD8+T cell infiltration,and diminished angiogenesis in the injured area,leading to a significant reduction in lesion volume.Additionally,we explored the potential mechanisms of NeuroD1 in situ neural regeneration technology through bulk RNA sequencing,which showed an upregulation of neurogenesis-related genes and a downregulation of immune response-related and angiogenesis-related genes.Furthermore,our findings suggested that NeuroD1 in situ neural regeneration technology converted reactive astrocytes into neurons and reduced microglial activation in a thalamic hemorrhagic stroke mouse model.In summary,this study supports NeuroD1 in situ neural regeneration technology as a potential therapeutic approach for treating radiation-induced brain injury and hemorrhagic stroke,and offers new insights into the therapeutic role of NeuroD1 in delayed brain injury.
基金supported by the Key Project of Guangzhou City,No.202206060002(to GC)the Guangdong Province Science and Technology Project of China,No.2018B030332001(to GC)+1 种基金the Natural Science Foundation of Guangdong Province of China,No.2020A1515010854(to QW)the Yi-Liang Liu Endowment Fund from Jinan University Education Development Foundation。
文摘Transcription factor-mediated cell conversion has been reported in the central nervous system of both rodents and nonhuman primates.In particular,glia-to-neuron conversion has been achieved in the brain and spinal cord of animal models for neural regeneration and repair.However,whether glia-to-neuron conversion can be used for brain repair in humans needs to be explored.To investigate the use of glia-to-neuron conversion technology in the human brain,we established a long-term ex vivo culture system using human brain tissue that was surgically removed from epileptic patients to test glia-to-neuron conversion directly.We found that neural transcription factors NeuroD1 and Ascl1 both converted human glial cells into neurons.Immunostaining and electrophysiological recordings showed that the glia-converted neurons demonstrated immature properties during the initial 7-14 days of conversion,and then acquired more mature neuronal properties after 21-27 days of conversion.These ex vivo conversion studies in human brain tissue pave the way toward future clinical trials using a transcription factor-based glia-to-neuron conversion approach to treat neurological disorders.
基金supported by the Key Project of Guangzhou City,No.202206060002Science and Technology Project of Guangdong Province,No.2018B030332001Guangdong Provincial Pearl River Project,No.2021ZT09Y552 (all to GC)。
文摘Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.
基金supported in part by the National Natural Science Foundation of China(Grant No.31701291 to WL,U1801681 to GC)the China Postdoctoral Science Foundation(Grant No.2016M602600 to WL)+1 种基金the Guangdong Grant ‘Key Technologies for Treatment of Brain Disorders’(Grant No.2018B030332001 to GC)the Internal Funding of Jinan University,China(Grant No.21616110 to GC)
文摘A new technology called in vivo glia-to-neuron conversion has emerged in recent years as a promising next generation therapy for neural regeneration and repair. This is achieved through reprogramming endogenous glial cells into neurons in the central nervous system through ectopically expressing neural transcriptional factors in glial cells. Previous studies have been focusing on glial cells in the grey matter such as the cortex and striatum, but whether glial cells in the white matter can be reprogrammed or not is unknown. To address this fundamental question, we express NeuroD1 in the astrocytes of both grey matter(cortex and striatum) and white matter(corpus callosum) to investigate the conversion efficiency, neuronal subtypes, and electrophysiological features of the converted neurons. We discover that NeuroD1 can efficiently reprogram the astrocytes in the grey matter into functional neurons, but the astrocytes in the white matter are much resistant to neuronal reprogramming. The converted neurons from cortical and striatal astrocytes are composed of both glutamatergic and GABAergic neurons, capable of firing action potentials and having spontaneous synaptic activities. In contrast, the few astrocyte-converted neurons in the white matter are rather immature with rare synaptic events. These results provide novel insights into the differential reprogramming capability between the astrocytes in the grey matter versus the white matter, and highlight the impact of regional astrocytes as well as microenvironment on the outcome of glia-toneuron conversion. Since human brain has large volume of white matter, this study will provide important guidance for future development of in vivo glia-to-neuron conversion technology into potential clinical therapies. Experimental protocols in this study were approved by the Laboratory Animal Ethics Committee of Jinan University(approval No. IACUC-20180321-03) on March 21, 2018.
基金supported by the Guangdong Grant Key Technologies for Treatment of Brain Disorders,China,No. 2018B030332001 (to GC)the Guangzhou Key Projects of Brain Science and Brain-Like Intelligence Technology,No. 20200730009 (to YX)the Guangdong Basic and Applied Basic Research Foundation,No. 2020A1515110898 (to WYC)。
文摘The onset of retinal degenerative disease is often associated with neuronal loss. Therefore, how to regenerate new neurons to restore vision is an important issue. NeuroD1 is a neural transcription factor with the ability to reprogram brain astrocytes into neurons in vivo. Here, we demonstrate that in adult mice, NeuroD1 can reprogram Müller cells, the principal glial cell type in the retina, to become retinal neurons. Most strikingly, ectopic expression of NeuroD1 using two different viral vectors converted Müller cells into different cell types. Specifically, AAV7 m8 GFAP681::GFP-ND1 converted Müller cells into inner retinal neurons, including amacrine cells and ganglion cells. In contrast, AAV9 GFAP104::ND1-GFP converted Müller cells into outer retinal neurons such as photoreceptors and horizontal cells, with higher conversion efficiency. Furthermore, we demonstrate that Müller cell conversion induced by AAV9 GFAP104::ND1-GFP displayed clear dose-and time-dependence. These results indicate that Müller cells in adult mice are highly plastic and can be reprogrammed into various subtypes of retinal neurons.
文摘目的·筛查青少年的成人起病型糖尿病(maturity-onset diabetes of the young,MODY)家系中NEUROD1基因突变,分析突变与中国人MODY6发病的相关性及其潜在的致病机制。方法·采用PCR-直接测序法对96例GCK/MODY2、HNF1A/MODY3、HNF1B/MODY5突变阴性的中国MODY先证者进行NEUROD1突变筛查,同时比较96例MODY先证者与100例非糖尿病对照者NEUROD1基因变异的基因型频率。采用从头建模法构建NEUROD1蛋白野生型和突变体的3D结构,采用双荧光素酶报告基因系统检测野生型和突变体蛋白对胰岛素基因转录活性的影响。结果·在一个MODY家系中发现NEUROD1基因杂合错义突变Glu59Gln (NM_002500.5,c.175G>C)。3D结构分析发现,该突变将野生型中带负电荷的Glu59转化为突变中不带电荷的Gln59,导致两个盐桥键Glu59-Arg54和Glu59-Lys88缺失,并形成一个新的氢键Gln59-Arg54。与野生型相比,Glu59Gln突变体的胰岛素基因转录活性下降36.3%(P<0.05)。与非糖尿病对照相比,96例MODY先证者中Ala45Thr (G-A)变异的AA+GA基因型频率显著升高(P=0.002)。结论·Glu59Gln突变改变了NEUROD1蛋白N端的分子构象,导致其胰岛素基因转录活性显著下降,是该家系突变携带者胰岛素分泌缺陷的原因。Ala45Thr变异与MODY6先证者糖尿病发病年龄的提前有关。
基金supported by the Guangdong Grant Key Technologies for Treatment of Brain Disorders,China,No.2018B030332001(to GC)the Natural Science Foundation of Guangdong Province,China,No.2023A1515012397(to YX).
文摘Optic nerve injury leads to axonal degeneration and the death of retinal ganglion cells,which ultimately causes vision loss.Notably,current treatments are limited.In the present study,we explored whether neurogenic differentiation factor 1(NeuroD1 or ND1)overexpression in retinal Müller cells may repair the retina after optic nerve crush in mice.Adult mice were subjected to optic nerve crush followed by intravitreal AAV-7m8-GFAP-GFP-ND1 virus injection.Immunofluorescent staining,multi-electrode array recording,electroretinogram,and visual behavior tests were then performed to examine retinal and optic nerve structure and retinal function at various post-optic nerve crush and virus injection times.Western blot analysis and quantitative reverse transcription polymerase chain reaction were performed to explore the possible mechanisms.Compared with the control virus,specific overexpression of ND1 in Müller cells greatly improved the light responses of retinal ganglion cells and retinal neurons in optic nerve crush-injured mice as early as 1-2 weeks post-virus injection and lasted for up to 4 weeks.Neuronal survival in the ganglion cell layer and synaptic connections in the inner retina were slightly improved at 2 weeks;however,visual behavior,retinal ganglion cell survival,and optic nerve structure were not improved.ND1 transiently enhanced glial cell-derived neurotrophic factor expression in the optic nerve crush-injured retina but hardly inhibited retinal inflammation within 2 weeks.Together,our data indicate that ND1 overexpression in Müller cells improves retinal function in the optic nerve crush-injured retina,and suggest that its neuroprotective effect may be caused by enhanced glial cell-derived neurotrophic factor release.
基金supported by the National Natural Science Foundation of China(Nos.81970686,81770791,81471012,81270876,to LL)the Interdisciplinary Program of Shanghai Jiao Tong University,China(No.YG2019ZDA08,to LL)+1 种基金the Shanghai Leading Talent,China(No.SLJ15055,to LL)the National Institute of Diabetes and Digestive and Kidney Diseases(No.SC1DK104821,to YL)
文摘Objective::In contrast to the most commonly reported forms of maturity-onset diabetes of the young(MODY),including MODY2,MODY3 and MODY5,MODY6 is a relatively rare subtype.To investigate whether NEUROD1 is responsible for MODY in Chinese individuals,we screened its mutations in MODY pedigrees and explored the potential pathogenic mechanisms.Methods::Polymerase chain reaction direct sequencing was performed to screen NEUROD1 mutations in 32 Chinese MODY probands who were negative for the GCK/MODY2,HNF1A/MODY3 and HNF1B/MODY5 genes in this observational study.In addition,we enrolled 201 unrelated,non-diabetic control subjects of Han Chinese descent.The functional significance of newly identified mutations was analyzed using clinical phenotype,pathophysiology and three-dimensional structure studies.This study was approved by the Institutional Review Board of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital,China(approval No.YS-2017-83)on March 3,2017.Results::E59Q(c.175 G>C,p.Glu59Gln),a heterozygous missense mutation in the NEUROD1 gene,was identified in one family with MODY.The Glu59 residue in NeuroD1 is highly conserved across mammalian species.Four diabetic patients carrying the mutation(a proband and her son,brother and sister)were lean,with a body mass index of 20.9(20.3-21.2)kg/m 2.Compared with their unaffected relatives(n=4),E59Q carriers(n=4)had significantly decreased ratios of fasting and 2-hour insulin to plasma glucose(both fasting plasma insulin/fasting plasma glucose and 2-hour postprandial plasma insulin/2-hour postprandial plasma glucose,P<0.005).The proband’s father had an E59Q mutation and normal glucose tolerance,which suggested non-penetrance.The E59Q mutation was not detected in other probands or in the 201 control subjects with normal glucose tolerance.Two salt-bridge bonds of Glu59 were disrupted at the Q59 mutation site.Conclusion::The NEUROD1-E59Q mutation changed the molecular conformation of the N-terminal in NeuroD1,which may decrease binding of the E59Q mutant to the insulin promoter and insulin gene transcription activity,therefore causing the MODY6 subtype with defective insulin secretion.
文摘1文献来源研究一:Rudin CM,Poirier JT,Byers LA,et al.Molecular subtypes of small cell lung cancer:A synthesis of human and mouse model data[J].Nat Rev Cancer,2019,19(5):289-297.研究二:Owonikoko TK,Dwivedi B,Chen ZJ,et al.YAP1 positive small-cell lung cancer subtype is associated with the T-cell inflamed gene expression profile and confers good prognosis and long term survival[J].J Clin Oncol,2020,38(15S):Abstr 9019.
