BACKGROUND ATP-binding cassette subfamily B member 4(ABCB4)deficiency is associated with cholestatic liver disease primarily because of missense mutations,and many variants remain unidentified.Here,we validate the pat...BACKGROUND ATP-binding cassette subfamily B member 4(ABCB4)deficiency is associated with cholestatic liver disease primarily because of missense mutations,and many variants remain unidentified.Here,we validate the pathogenicity and mechanism of ABCB4 variants in clinical and in vitro trials,hypothesizing that these variants are responsible for impaired biliary function and contribute to the development of cholestatic liver diseases.AIM To clarify the functional features and pathogenicity of ABCB4 variants.METHODS Clinical data were collected from five patients with cholestatic liver disease that was initially not detected by routine examinations.Later,whole-exome sequencing confirmed ABCB4 variants and the patients were treated from January 2017 to December 2023.Pathogenic mechanisms were analyzed using bioinformatics tools,and a cell model in vitro was established to investigate ABCB4 mRNA expression,multidrug resistance protein 3(MDR3)expression,cellular localization,and phosphatidylcholine secretion.Results were compared using Student's t-tests.RESULTS Five missense variants(c.1757T>A,c.1865G>A,c.2362C>T,c.2777C>T and c.3250C>T),one intron variant(c.537-32G>T),and one synonymous(c.C504T)variant were identified.Three of the five patients had various degrees of cholestasis,two presented with liver cirrhosis,and all had elevated gamma-glutamyl transferase.Three of the four patients who underwent a liver biopsy had bile duct dilation,and one had gallstones.Two of the four patients had normal and reduced MDR3 immunohistochemical levels.Bioinformatic analysis indicated that these variants were likely pathogenic except c.C504T variant.None of the missense variants influenced subcellular MDR3 Localization in vitro.However,the c.1865G>A variant significantly decreased ABCB4 mRNA values,and all missense variants down-regulated phosphatidylcholine secretion.CONCLUSION This study uncovered new ABCB4 variants and emphasized the pathogenic potential of specific variants.The findings from five patients provided insight into the pathogenic mechanisms underlying ABCB4-related diseases.展开更多
As a crucial transcription factor for spermatogenesis,GATA-binding protein 4(GATA4)plays important roles in the functioning of Sertoli and Leydig cells.Conditional knockout of GATA4 in mice results in age-dependent te...As a crucial transcription factor for spermatogenesis,GATA-binding protein 4(GATA4)plays important roles in the functioning of Sertoli and Leydig cells.Conditional knockout of GATA4 in mice results in age-dependent testicular atrophy and loss of fertility.However,whether GATA4 is associated with human azoospermia has not been reported.Herein,we analyzed the GATA4 gene by direct sequencing of samples obtained from 184 Chinese men with idiopathic nonobstructive azoospermia(NOA).We identified a missense mutation(c.191G>A,p.G64E),nine single-nucleotide polymorphisms(SNPs),and one rare variant(c.^(*)84C>T)in the 3′untranslated region(UTR).Functional studies demonstrated that the p.G64E mutation did not affect transactivation ability of GATA4 for spermatogenesis-related genes(claudin-11 and steroidogenic acute regulatory protein,Star),and the 3′UTR rare variant c.^(*)84C>T did not generate microRNA-binding sites to repress GATA4 expression.To our knowledge,this is the first report to investigate the association between GATA4 and azoospermia;our results indicate that mutations in GATA4 may not be pathogenic for NOA in Chinese men.展开更多
The connexin family of mammalian gap junction proteins provides intercellular communication channels critical for development and tissue function.Mutations in connexins are associated with numerous diseases including ...The connexin family of mammalian gap junction proteins provides intercellular communication channels critical for development and tissue function.Mutations in connexins are associated with numerous diseases including deafness,skin diseases,cataracts.展开更多
In accordance with previous reports, the sequences related to phosporylated protein segments occur in conserved variable domains of immunoglobulins including first of all certain N-terminally located segments. Consequ...In accordance with previous reports, the sequences related to phosporylated protein segments occur in conserved variable domains of immunoglobulins including first of all certain N-terminally located segments. Consequently, we look here for the sequences 1) composing human and mouse proteins different from antigen receptors, 2) identical with or highly similar to nucleotide sequence representatives of conserved variable immunoglobulin segments and 3) identical with or closely related to phosphorylation sites. More precisely, we searched for the corresponding actual pairs of DNA and protein sequence segments using five-step bilingual approach employing among others a) different types of BLAST searches, b) two in-principle-different machine-learning methods predicting phosphorylated sites and c) two large databases recording existing phosphorylation sites. The approach identified seven existing phosphorylation sites and thirty-seven related human and mouse segments achieving limits for several predictions or phylogenic parameters. Mostly serines phosporylated with ataxia-telangiectasia-related kinase (involved in regulation of DNA-double-strand-break repair) were indicated or predicted in this study. Hypermutation motifs, located in effective positions of the selected sequence segments, occurred significantly less frequently in transcribed than non-transcribed DNA strands suggesting thus the incidence of mutation events. In addition, marked differences between the numbers and proportions of human and mouse cancer-related sequence items were found in different steps of selection process. The possible role of hypermutation changes within the selected segments and the observed structural relationships are discussed here with respect to DNA damage, carcinogenesis, cancer vaccination, ageing and evolution. Taken together, our data represent additional and sometimes perhaps complementary information to the existing databases of empirically proven phosphorylation sites or pathogenically important spots.展开更多
Extracellular vesicles(EVs)have garnered significant attention in biomedical applications.However,the rapid,efficient,and unbiased separation of EVs from complex biological fluids remains a challenge due to their het-...Extracellular vesicles(EVs)have garnered significant attention in biomedical applications.However,the rapid,efficient,and unbiased separation of EVs from complex biological fluids remains a challenge due to their het-erogeneity and low abundance in biofluids.Herein,we report a novel approach to reconfigure and modify an artificial insertion peptide for the unbiased and rapid isolation of EVs in 20 min with~80%recovery in neutral conditions.Moreover,the approach demonstrates exceptional anti-interference capability and achieves a high purity of EVs comparable to standard ultracentrifugation and other methods.Importantly,the isolated EVs could be directly applied for downstream protein and nucleic acid analyses,including proteomics analysis,exome sequencing analysis,as well as the detection of both epidermal growth factor receptor(EGFR)and V-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homologue(KRAS)gene mutation in clinical plasma samples.Our approach offers great possibilities for utilizing EVs in liquid biopsy,as well as in various other biomedical applications.展开更多
基金Supported by the National Natural Science Foundation of China,No.81970454.
文摘BACKGROUND ATP-binding cassette subfamily B member 4(ABCB4)deficiency is associated with cholestatic liver disease primarily because of missense mutations,and many variants remain unidentified.Here,we validate the pathogenicity and mechanism of ABCB4 variants in clinical and in vitro trials,hypothesizing that these variants are responsible for impaired biliary function and contribute to the development of cholestatic liver diseases.AIM To clarify the functional features and pathogenicity of ABCB4 variants.METHODS Clinical data were collected from five patients with cholestatic liver disease that was initially not detected by routine examinations.Later,whole-exome sequencing confirmed ABCB4 variants and the patients were treated from January 2017 to December 2023.Pathogenic mechanisms were analyzed using bioinformatics tools,and a cell model in vitro was established to investigate ABCB4 mRNA expression,multidrug resistance protein 3(MDR3)expression,cellular localization,and phosphatidylcholine secretion.Results were compared using Student's t-tests.RESULTS Five missense variants(c.1757T>A,c.1865G>A,c.2362C>T,c.2777C>T and c.3250C>T),one intron variant(c.537-32G>T),and one synonymous(c.C504T)variant were identified.Three of the five patients had various degrees of cholestasis,two presented with liver cirrhosis,and all had elevated gamma-glutamyl transferase.Three of the four patients who underwent a liver biopsy had bile duct dilation,and one had gallstones.Two of the four patients had normal and reduced MDR3 immunohistochemical levels.Bioinformatic analysis indicated that these variants were likely pathogenic except c.C504T variant.None of the missense variants influenced subcellular MDR3 Localization in vitro.However,the c.1865G>A variant significantly decreased ABCB4 mRNA values,and all missense variants down-regulated phosphatidylcholine secretion.CONCLUSION This study uncovered new ABCB4 variants and emphasized the pathogenic potential of specific variants.The findings from five patients provided insight into the pathogenic mechanisms underlying ABCB4-related diseases.
基金This research was supported by the National Natural Science Foundation of China(No.81601337)the Fundamental Research Funds of Shandong University(No.2016HW006)+1 种基金the Key research and development program of Shandong Province(No.2019GSF108237)The authors thank all of the participants involved in this study.
文摘As a crucial transcription factor for spermatogenesis,GATA-binding protein 4(GATA4)plays important roles in the functioning of Sertoli and Leydig cells.Conditional knockout of GATA4 in mice results in age-dependent testicular atrophy and loss of fertility.However,whether GATA4 is associated with human azoospermia has not been reported.Herein,we analyzed the GATA4 gene by direct sequencing of samples obtained from 184 Chinese men with idiopathic nonobstructive azoospermia(NOA).We identified a missense mutation(c.191G>A,p.G64E),nine single-nucleotide polymorphisms(SNPs),and one rare variant(c.^(*)84C>T)in the 3′untranslated region(UTR).Functional studies demonstrated that the p.G64E mutation did not affect transactivation ability of GATA4 for spermatogenesis-related genes(claudin-11 and steroidogenic acute regulatory protein,Star),and the 3′UTR rare variant c.^(*)84C>T did not generate microRNA-binding sites to repress GATA4 expression.To our knowledge,this is the first report to investigate the association between GATA4 and azoospermia;our results indicate that mutations in GATA4 may not be pathogenic for NOA in Chinese men.
基金Instituto de Salud Carlos III,grant PI21/00470 co-financed by the European Regional Development Fund.
文摘The connexin family of mammalian gap junction proteins provides intercellular communication channels critical for development and tissue function.Mutations in connexins are associated with numerous diseases including deafness,skin diseases,cataracts.
文摘In accordance with previous reports, the sequences related to phosporylated protein segments occur in conserved variable domains of immunoglobulins including first of all certain N-terminally located segments. Consequently, we look here for the sequences 1) composing human and mouse proteins different from antigen receptors, 2) identical with or highly similar to nucleotide sequence representatives of conserved variable immunoglobulin segments and 3) identical with or closely related to phosphorylation sites. More precisely, we searched for the corresponding actual pairs of DNA and protein sequence segments using five-step bilingual approach employing among others a) different types of BLAST searches, b) two in-principle-different machine-learning methods predicting phosphorylated sites and c) two large databases recording existing phosphorylation sites. The approach identified seven existing phosphorylation sites and thirty-seven related human and mouse segments achieving limits for several predictions or phylogenic parameters. Mostly serines phosporylated with ataxia-telangiectasia-related kinase (involved in regulation of DNA-double-strand-break repair) were indicated or predicted in this study. Hypermutation motifs, located in effective positions of the selected sequence segments, occurred significantly less frequently in transcribed than non-transcribed DNA strands suggesting thus the incidence of mutation events. In addition, marked differences between the numbers and proportions of human and mouse cancer-related sequence items were found in different steps of selection process. The possible role of hypermutation changes within the selected segments and the observed structural relationships are discussed here with respect to DNA damage, carcinogenesis, cancer vaccination, ageing and evolution. Taken together, our data represent additional and sometimes perhaps complementary information to the existing databases of empirically proven phosphorylation sites or pathogenically important spots.
基金supported by the National Natural Science Foundation of China(Grant No.21804105,22174049,31971155)the Program for HUST Academic Frontier Youth Team(Grant No.2019QYTD09)+3 种基金the Natural Science Foundation of Hubei Province of China(No.2021CFB335)the Fundamental Research Funds for the Central Universities in China(Grant Nos.2172019KFYRCPY112,2172020kfyXJJS082)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2020329)the Funda-mental Research Funds for the Central Universities,HUST:Grant Nos.2023JYCXJJ060.
文摘Extracellular vesicles(EVs)have garnered significant attention in biomedical applications.However,the rapid,efficient,and unbiased separation of EVs from complex biological fluids remains a challenge due to their het-erogeneity and low abundance in biofluids.Herein,we report a novel approach to reconfigure and modify an artificial insertion peptide for the unbiased and rapid isolation of EVs in 20 min with~80%recovery in neutral conditions.Moreover,the approach demonstrates exceptional anti-interference capability and achieves a high purity of EVs comparable to standard ultracentrifugation and other methods.Importantly,the isolated EVs could be directly applied for downstream protein and nucleic acid analyses,including proteomics analysis,exome sequencing analysis,as well as the detection of both epidermal growth factor receptor(EGFR)and V-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homologue(KRAS)gene mutation in clinical plasma samples.Our approach offers great possibilities for utilizing EVs in liquid biopsy,as well as in various other biomedical applications.
