BACKGROUND Mutations in mitochondrial tRNA(mt-tRNA)genes that result in mitochondrial dysfunction play important roles in type 2 diabetes mellitus(T2DM).We previously reported a large Chinese pedigree with maternally ...BACKGROUND Mutations in mitochondrial tRNA(mt-tRNA)genes that result in mitochondrial dysfunction play important roles in type 2 diabetes mellitus(T2DM).We previously reported a large Chinese pedigree with maternally inherited T2DM that harbors novel mt-tRNA^(Trp)A5514G and tRNA^(Ser(AGY))C12237T variants,however,the effects of these mt-tRNA variants on T2DM progression are largely unknown.AIM To assess the potential pathogenicity of T2DM-associated m.A5514G and m.C12237T variants at genetic,molecular,and biochemical levels.METHODS Cytoplasmic hybrid(cybrid)cells carrying both m.A5514G and m.C12237T variants,and healthy control cells without these mitochondrial DNA(mtDNA)variants were generated using trans-mitochondrial technology.Mitochondrial features,including mt-tRNA steady-state level,levels of adenosine triphosphate(ATP),mitochondrial membrane potential(MMP),reactive oxygen species(ROS),mtDNA copy number,nicotinamide adenine dinucleotide(NAD+)/NADH ratio,enzymatic activities of respiratory chain complexes(RCCs),8-hydroxy-deoxyguanine(8-OhdG),malondialdehyde(MDA),and superoxide dismutase(SOD)were examined in cell lines with and without these mt-tRNA variants.RESULTS Compared with control cells,the m.A5514G variant caused an approximately 35%reduction in the steady-state level of mt-tRNA^(Trp)(P<0.0001);however,the m.C12237T variant did not affect the mt-tRNA^(Ser(AGY))steady-state level(P=0.5849).Biochemical analysis revealed that cells with both m.A5514G and m.C12237T variants exhibited more severe mitochondrial dysfunctions and elevated oxidative stress than control cells:ATP,MMP,NAD+/NADH ratio,enzyme activities of RCCs and SOD levels were markedly decreased in mutant cells(P<0.05 for all measures).By contrast,the levels of ROS,8-OhdG and MDA were significantly increased(P<0.05 for all measures),but mtDNA copy number was not affected by m.A5514G and m.C12237T variants(P=0.5942).CONCLUSION The m.A5514G variant impaired mt-tRNA^(Trp)metabolism,which subsequently caused mitochondrial dysfunction.The m.C12237T variant did not alter the steady-state level of mt-tRNA^(Ser(AGY)),indicating that it may be a modifier of the m.A5514G variant.The m.A5514G variant may exacerbate the pathogenesis and progression of T2DM in this Chinese pedigree.展开更多
Clouston syndrome(OMIM#129500),also known as hidrotic ectodermal dysplasia type 2,is a rare autosomal dominant skin disorder.To date,four mutations in the GJB6 gene,G11R,V37E,A88V,and D50N,have been confirmed to cause...Clouston syndrome(OMIM#129500),also known as hidrotic ectodermal dysplasia type 2,is a rare autosomal dominant skin disorder.To date,four mutations in the GJB6 gene,G11R,V37E,A88V,and D50N,have been confirmed to cause this condition.In previous studies,the focus has been mainly on gene sequencing,and there has been a lack of research on clinical manifestations and pathogenesis.To confirm the diagnosis of this pedigree at the molecular level and summarize and analyse the clinical phenotype of patients and to provide a basis for further study of the pathogenesis of the disease,we performed whole-exome and Sanger sequencing on a large Chinese Clouston syndrome pedigree.Detailed clinical examination included histopathology,hair microscopy,and scanning electron microscopy.We found a novel heterozygous missense variant(c.134G>C:p.G45A)for Clouston syndrome.We identified a new clinical phenotype involving all nail needling pain in all patients and found a special honeycomb hole structure in the patients’hair under scanning electron microscopy.Our data reveal that a novel variant(c.134G>C:p.G45A)plays a likely pathogenic role in this pedigree and highlight that genetic testing is necessary for the diagnosis of Clouston syndrome.展开更多
BACKGROUND Thus far,genetic analysis of patients clinically diagnosed with glycogen storage diseases(GSDs)in Thailand has not been reported.AIM To evaluate the clinical and biochemical profiles,molecular analysis and ...BACKGROUND Thus far,genetic analysis of patients clinically diagnosed with glycogen storage diseases(GSDs)in Thailand has not been reported.AIM To evaluate the clinical and biochemical profiles,molecular analysis and long-term outcomes of Thai children diagnosed with hepatic GSD.METHODS Children aged<18 years diagnosed with hepatic GSD and followed up at King Chulalongkorn Memorial Hospital were recruited.Whole-exome sequencing(WES)was performed to identify the causative gene variants.Medical records were assessed.RESULTS All eight children with histopathologically confirmed diagnosis were classified by WES into subtypes Ia(n=1),III(n=3),VI(n=3),and IX(n=1).A total number of 10 variants were identified including G6PC(n=1),AGL(n=4),PYGL(n=5),and PHKA2(n=1).AGL had two novel variants.The clinical manifestations were hepatomegaly(n=8),doll-like facies(n=3),wasting(n=2),and stunting(n=5).All patients showed hypoglycemia,transaminitis,and dyslipidemia.The mainstay of treatment was cornstarch supplementation and high-protein and low-lactosefructose diet.After a median follow-up time of 9.59 years,height turned to normal for age in 3/5 patients and none had malnutrition.Liver enzymes,blood sugar,and lipid profiles improved in all.CONCLUSION Hepatomegaly,transaminitis,and hypoglycemia are the hallmarks of GSD confirmed by liver histopathology.Molecular analysis can confirm the diagnosis or classify the subtype that might benefit from personalized treatment,prognosis,and long-term care.展开更多
Infectious bursal disease(IBD)is caused by infectious bursal disease virus(IBDV),which has a genome consisting of two segments of double-stranded linear RNA.IBDVs have been traditionally divided into four phenotypes b...Infectious bursal disease(IBD)is caused by infectious bursal disease virus(IBDV),which has a genome consisting of two segments of double-stranded linear RNA.IBDVs have been traditionally divided into four phenotypes based on their pathogenicity and antigenicity,including classic,variant,very virulent,and attenuated IBDV.With the emergences of divergent molecular characteristics of novel strains produced by continuous mutations and recombination,it is increasingly difficult to define new IBDV strains using the traditional descriptive classification method.The most common classification scheme for IBDV with segmented genome is based solely on segment A,while the significance of segment B has been largely neglected.In this study,an improved scheme for IBDV genotype classification based on the molecular characteristics of both VP2(a viral capsid protein encoded by segment A)and VP1(an RNA-dependent RNA polymerase protein encoded by segment B)was proposed for the first time.In this scheme,IBDV was classified into nine genogroups of A and five genogroups of B,respectively;the genogroup A2 was further divided into four lineages.The commonly used phenotypic classifications of classic,variant,very virulent,and attenuated IBDVs correspond to the A1 B1,A2 B1,A3 B2,and A8 B1 genotypes of the proposed classification scheme.The novel variant IBDVs including the strains identified in this study were classified as belonging to genotype A2 d B1.The flexibility and versatility of this improved classification scheme will allow the unambiguous identification of existing and emerging IBDV strains,which will greatly facilitate molecular epidemiology studies of IBDV.展开更多
基金Supported by the Hangzhou Joint Fund of the Zhejiang Provincial Natural Science Foundation of China,No.LHZY24H020002Hangzhou Municipal Health Commission,No.ZD20220010Quzhou Bureau of Science and Technology,No.2022K51.
文摘BACKGROUND Mutations in mitochondrial tRNA(mt-tRNA)genes that result in mitochondrial dysfunction play important roles in type 2 diabetes mellitus(T2DM).We previously reported a large Chinese pedigree with maternally inherited T2DM that harbors novel mt-tRNA^(Trp)A5514G and tRNA^(Ser(AGY))C12237T variants,however,the effects of these mt-tRNA variants on T2DM progression are largely unknown.AIM To assess the potential pathogenicity of T2DM-associated m.A5514G and m.C12237T variants at genetic,molecular,and biochemical levels.METHODS Cytoplasmic hybrid(cybrid)cells carrying both m.A5514G and m.C12237T variants,and healthy control cells without these mitochondrial DNA(mtDNA)variants were generated using trans-mitochondrial technology.Mitochondrial features,including mt-tRNA steady-state level,levels of adenosine triphosphate(ATP),mitochondrial membrane potential(MMP),reactive oxygen species(ROS),mtDNA copy number,nicotinamide adenine dinucleotide(NAD+)/NADH ratio,enzymatic activities of respiratory chain complexes(RCCs),8-hydroxy-deoxyguanine(8-OhdG),malondialdehyde(MDA),and superoxide dismutase(SOD)were examined in cell lines with and without these mt-tRNA variants.RESULTS Compared with control cells,the m.A5514G variant caused an approximately 35%reduction in the steady-state level of mt-tRNA^(Trp)(P<0.0001);however,the m.C12237T variant did not affect the mt-tRNA^(Ser(AGY))steady-state level(P=0.5849).Biochemical analysis revealed that cells with both m.A5514G and m.C12237T variants exhibited more severe mitochondrial dysfunctions and elevated oxidative stress than control cells:ATP,MMP,NAD+/NADH ratio,enzyme activities of RCCs and SOD levels were markedly decreased in mutant cells(P<0.05 for all measures).By contrast,the levels of ROS,8-OhdG and MDA were significantly increased(P<0.05 for all measures),but mtDNA copy number was not affected by m.A5514G and m.C12237T variants(P=0.5942).CONCLUSION The m.A5514G variant impaired mt-tRNA^(Trp)metabolism,which subsequently caused mitochondrial dysfunction.The m.C12237T variant did not alter the steady-state level of mt-tRNA^(Ser(AGY)),indicating that it may be a modifier of the m.A5514G variant.The m.A5514G variant may exacerbate the pathogenesis and progression of T2DM in this Chinese pedigree.
基金funded by Anhui Provincial Quality Engineering Project of Higher Education Institutions(No.2020jyxm0922)Natural Science Research Project of Higher Education Department of Anhui Province(No.KJ2021A0284)+1 种基金Fund of Anhui Provincial Institute of Translational Medicine(No.2021zhyx-C31)Research Foundation of Anhui Medical University(No.2020xkj154).
文摘Clouston syndrome(OMIM#129500),also known as hidrotic ectodermal dysplasia type 2,is a rare autosomal dominant skin disorder.To date,four mutations in the GJB6 gene,G11R,V37E,A88V,and D50N,have been confirmed to cause this condition.In previous studies,the focus has been mainly on gene sequencing,and there has been a lack of research on clinical manifestations and pathogenesis.To confirm the diagnosis of this pedigree at the molecular level and summarize and analyse the clinical phenotype of patients and to provide a basis for further study of the pathogenesis of the disease,we performed whole-exome and Sanger sequencing on a large Chinese Clouston syndrome pedigree.Detailed clinical examination included histopathology,hair microscopy,and scanning electron microscopy.We found a novel heterozygous missense variant(c.134G>C:p.G45A)for Clouston syndrome.We identified a new clinical phenotype involving all nail needling pain in all patients and found a special honeycomb hole structure in the patients’hair under scanning electron microscopy.Our data reveal that a novel variant(c.134G>C:p.G45A)plays a likely pathogenic role in this pedigree and highlight that genetic testing is necessary for the diagnosis of Clouston syndrome.
基金Supported by Ratchadaphiseksomphot Fund,Graduate Affairs,Faculty of Medicine,Chulalongkorn University,No.GA66/020Ratchadaphiseksomphot Fund,Chulalongkorn University,No.RCU_H_64_007_30.
文摘BACKGROUND Thus far,genetic analysis of patients clinically diagnosed with glycogen storage diseases(GSDs)in Thailand has not been reported.AIM To evaluate the clinical and biochemical profiles,molecular analysis and long-term outcomes of Thai children diagnosed with hepatic GSD.METHODS Children aged<18 years diagnosed with hepatic GSD and followed up at King Chulalongkorn Memorial Hospital were recruited.Whole-exome sequencing(WES)was performed to identify the causative gene variants.Medical records were assessed.RESULTS All eight children with histopathologically confirmed diagnosis were classified by WES into subtypes Ia(n=1),III(n=3),VI(n=3),and IX(n=1).A total number of 10 variants were identified including G6PC(n=1),AGL(n=4),PYGL(n=5),and PHKA2(n=1).AGL had two novel variants.The clinical manifestations were hepatomegaly(n=8),doll-like facies(n=3),wasting(n=2),and stunting(n=5).All patients showed hypoglycemia,transaminitis,and dyslipidemia.The mainstay of treatment was cornstarch supplementation and high-protein and low-lactosefructose diet.After a median follow-up time of 9.59 years,height turned to normal for age in 3/5 patients and none had malnutrition.Liver enzymes,blood sugar,and lipid profiles improved in all.CONCLUSION Hepatomegaly,transaminitis,and hypoglycemia are the hallmarks of GSD confirmed by liver histopathology.Molecular analysis can confirm the diagnosis or classify the subtype that might benefit from personalized treatment,prognosis,and long-term care.
基金the Natural Science Foundation of Heilongjiang Province,China(ZD2020C006 and TD2019C003)the National Key Research and Development Program of China(2016YFE0203200)+2 种基金the Heilongjiang Province Foundation for the National Key Research and Development Program of China(GX18B011)the Major Project of National Natural Science Foundation of China(31430087)the earmarked fund for China Agriculture Research System(CARS-41-G15)。
文摘Infectious bursal disease(IBD)is caused by infectious bursal disease virus(IBDV),which has a genome consisting of two segments of double-stranded linear RNA.IBDVs have been traditionally divided into four phenotypes based on their pathogenicity and antigenicity,including classic,variant,very virulent,and attenuated IBDV.With the emergences of divergent molecular characteristics of novel strains produced by continuous mutations and recombination,it is increasingly difficult to define new IBDV strains using the traditional descriptive classification method.The most common classification scheme for IBDV with segmented genome is based solely on segment A,while the significance of segment B has been largely neglected.In this study,an improved scheme for IBDV genotype classification based on the molecular characteristics of both VP2(a viral capsid protein encoded by segment A)and VP1(an RNA-dependent RNA polymerase protein encoded by segment B)was proposed for the first time.In this scheme,IBDV was classified into nine genogroups of A and five genogroups of B,respectively;the genogroup A2 was further divided into four lineages.The commonly used phenotypic classifications of classic,variant,very virulent,and attenuated IBDVs correspond to the A1 B1,A2 B1,A3 B2,and A8 B1 genotypes of the proposed classification scheme.The novel variant IBDVs including the strains identified in this study were classified as belonging to genotype A2 d B1.The flexibility and versatility of this improved classification scheme will allow the unambiguous identification of existing and emerging IBDV strains,which will greatly facilitate molecular epidemiology studies of IBDV.
