BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a major health burden with an increasing global incidence.Unfortunately,the unavailability of knowledge underlying NAFLD pathogenesis inhibits effective preventive...BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a major health burden with an increasing global incidence.Unfortunately,the unavailability of knowledge underlying NAFLD pathogenesis inhibits effective preventive and therapeutic measures.AIM To explore the molecular mechanism of NAFLD.METHODS Whole genome sequencing(WGS)analysis was performed on liver tissues from patients with NAFLD(n=6)and patients with normal metabolic conditions(n=6)to identify the target genes.A NAFLD C57BL6/J mouse model induced by 16 wk of high-fat diet feeding and a hepatocyte-specific F-box only protein 2(FBXO2)overexpression mouse model were used for in vivo studies.Plasmid transfection,co-immunoprecipitation-based mass spectrometry assays,and ubiquitination in HepG2 cells and HEK293T cells were used for in vitro studies.RESULTS A total of 30982 genes were detected in WGS analysis,with 649 up-regulated and 178 down-regulated.Expression of FBXO2,an E3 ligase,was upregulated in the liver tissues of patients with NAFLD.Hepatocyte-specific FBXO2 overexpression facilitated NAFLD-associated phenotypes in mice.Overexpression of FBXO2 aggravated odium oleate(OA)-induced lipid accumulation in HepG2 cells,resulting in an abnormal expression of genes related to lipid metabolism,such as fatty acid synthase,peroxisome proliferator-activated receptor alpha,and so on.In contrast,knocking down FBXO2 in HepG2 cells significantly alleviated the OA-induced lipid accumulation and aberrant expression of lipid metabolism genes.The hydroxyl CoA dehydrogenase alpha subunit(HADHA),a protein involved in oxidative stress,was a target of FBXO2-mediated ubiquitination.FBXO2 directly bound to HADHA and facilitated its proteasomal degradation in HepG2 and HEK293T cells.Supplementation with HADHA alleviated lipid accumulation caused by FBXO2 overexpression in HepG2 cells.CONCLUSION FBXO2 exacerbates lipid accumulation by targeting HADHA and is a potential therapeutic target for NAFLD。展开更多
BACKGROUND Interleukin 10 receptor alpha subunit(IL10RA)dysfunction is the main cause of very early-onset inflammatory bowel disease(VEO-IBD)in East Asians.AIM To identify disease-causing gene mutations in four patien...BACKGROUND Interleukin 10 receptor alpha subunit(IL10RA)dysfunction is the main cause of very early-onset inflammatory bowel disease(VEO-IBD)in East Asians.AIM To identify disease-causing gene mutations in four patients with VEO-IBD and verify functional changes related to the disease-causing mutations.METHODS From May 2016 to September 2020,four young patients with clinically diagnosed VEO-IBD were recruited.Before hospitalization,using targeted gene panel sequencing and trio-whole-exome sequencing(WES),three patients were found to harbor a IL10RA mutation(c.301C>T,p.R101W in one patient;c.537G>A,p.T179T in two patients),but WES results of the fourth patient were not conclusive.We performed whole-genome sequencing(WGS)on patients A and B and reanalyzed the data from patients C and D.Peripheral blood mononuclear cells(PBMCs)from patient D were isolated and stimulated with lipopolysaccharide(LPS),interleukin 10(IL-10),and LPS+IL-10.Serum IL-10 levels in four patients and tumor necrosis factor-α(TNF-α)in the cell supernatant were determined by enzyme-linked immunosorbent assay.Phosphorylation of signal transducer and activator of transcription 3(STAT3)at Tyr705 and Ser727 in PBMCs was determined by western blot analysis.RESULTS The four children in our study consisted of two males and two females.The age at disease onset ranged from 18 d to 9 mo.After hospitalization,a novel 333-bp deletion encompassing exon 1 of IL10RA was found in patients A and B using WGS and was found in patients C and D after reanalysis of their WES data.Patient D was homozygous for the 333 bp deletion.All four patients had elevated serum IL-10 levels.In vitro,IL-10-stimulated PBMCs from patient D failed to induce STAT3 phosphorylation at Tyr705 and only minimally suppressed TNF-αproduction induced by LPS.Phosphorylation at Ser727 in PBMCs was not affected by LPS or LPS+IL-10 in both healthy subjects and in patient D.CONCLUSION WGS revealed a novel 333-bp deletion of IL10RA in four patients with VEO-IBD,whereas the WES results were inconclusive.展开更多
BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its ro...BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its role in hepatocellular carcinoma(HCC)has not been fully deciphered.AIM To decipher the role of CDKN2B-AS1 in the progression of HCC.METHODS CDKN2B-AS1 expression in HCC was detected by quantitative real-time polymerase chain reaction.The malignant phenotypes of Li-7 and SNU-182 cells were detected by the CCK-8 method,EdU method,and flow cytometry,respectively.RNA immunoprecipitation was executed to confirm the interaction between CDKN2B-AS1 and E2F transcription factor 1(E2F1).Luciferase reporter assay and chromatin immunoprecipitation were performed to verify the binding of E2F1 to the promoter of G protein subunit alpha Z(GNAZ).E2F1 and GNAZ were detected by western blot in HCC cells.RESULTS In HCC tissues,CDKN2B-AS1 was upregulated.Depletion of CDKN2B-AS1 inhibited the proliferation of HCC cells,and the depletion of CDKN2B-AS1 also induced cell cycle arrest and apoptosis.CDKN2B-AS1 could interact with E2F1.Depletion of CDKN2B-AS1 inhibited the binding of E2F1 to the GNAZ promoter region.Overexpression of E2F1 reversed the biological effects of depletion of CDKN2B-AS1 on the malignant behaviors of HCC cells.CONCLUSION CDKN2B-AS1 recruits E2F1 to facilitate GNAZ transcription to promote HCC progression.展开更多
DNA polymerase Ⅲ is one of the five eubacterial DNA polymerases that is responsible for the replication of DNA duplex. Among the ten subunits of the DNA polymerase Ⅲ core enzyme, the alpha subunit catalyzes the reac...DNA polymerase Ⅲ is one of the five eubacterial DNA polymerases that is responsible for the replication of DNA duplex. Among the ten subunits of the DNA polymerase Ⅲ core enzyme, the alpha subunit catalyzes the reaction for polymerizing both DNA strands. In this study, we extracted genomic sequences of the alpha subunit from 159 sequenced eubacterial genomes, and carried out sequence- based phylogenetic and structural analyses. We found that all eubacterial genomes have one or more alpha subunits, which form either homodimers or heterodimers. Phylogenetic and domain structural analyses as well as copy number variations of the alpha subunit in each bacterium indicate the classification of alpha subunit into four basic groups: polC, dnaE1, dnaE2, and dnaE3. This classification is of essence in genome composition analysis. We also consolidated the naming convention to avoid further confusion in gene annotations.展开更多
Objecitve To explore whether phosphoinositide specific phospholipase C (PLC) activation via G protein in vascular smooth muscle cells (VSMCs) is altered in spontaneously hypertensive rats (SHR). Methods The VSMCs ...Objecitve To explore whether phosphoinositide specific phospholipase C (PLC) activation via G protein in vascular smooth muscle cells (VSMCs) is altered in spontaneously hypertensive rats (SHR). Methods The VSMCs derived from aortae of SHR and Wistar Kyoto (WKY) rats were loaded for 48 hours with myo inositol. Inositol phosphate release was initiated by the addition of 10 5 mol/L norepinephrine in intact cells or by guanosine 5' 0 (3 thio tri sphosphate) (GTP gamma S) in permeabilized cells. In the meantime, growth arrested VSMCs were stimulated by 10% calf serum for 0, 30, 45, or 60 min, then gene expressions of Gq alpha subunit (G alph a q) were observed. Results There were no significant differences in inositol 1, 4,5 triphosphate (IP 3) level and expression of G alpha q mRNA between quiescent VSMCs from SHR and that from WKY. When stimulated by norepinephrine, IP 3 production increased transiently with a peak level at 10 s in VSMCs from WKY, and a rapid biphasic IP 3 response, which was significantly higher than that of WKY, in VSMCs from SHR had been observed. G proteins activated by GTP gamma S significantly raised IP 3 production in VSMCs from SHR compared to WKY (SHR vs WKY: 234.8%±29.2% vs 142.4%±12.0% of basal IP 3, P<0.05). In addition, the serum effect showed an significant increase in expression of G alpha q mRNA in VSMCs from SHR. Conclusions The hereditary factors are not the only variable regulating IP 3 metabolism and G alpha q gene expression. Influences of multi environmental factors such as vasoactive compounds, together with genetic predisposition, palys an important role in the highly sensitive response of IP 3 production and G alpha q gene over expression in SHR.展开更多
目的:本研究旨在探究超大型刺激性G蛋白α亚单位(extra-large stimulatory G protein alpha subunit, XLαs)在小鼠颅骨发育和成骨分化中的功能及分子机制。方法:通过构建XLαs第一外显子敲除的小鼠模型,运用阿尔新蓝茜素红染色技术分...目的:本研究旨在探究超大型刺激性G蛋白α亚单位(extra-large stimulatory G protein alpha subunit, XLαs)在小鼠颅骨发育和成骨分化中的功能及分子机制。方法:通过构建XLαs第一外显子敲除的小鼠模型,运用阿尔新蓝茜素红染色技术分析颅骨表型变化。从小鼠颅骨中分离原代颅骨成骨细胞,进行体外培养并诱导成骨分化,同时通过实时荧光定量聚合酶链反应和RNA测序技术对基因表达及其功能进行分析。结果:实验结果显示,XLαs敲除小鼠颅缝宽度增加(P<0.05),颅骨未矿化区域明显增多(P<0.001),且成骨分化能力受抑制(P<0.01)。RNA测序进一步揭示XLαs缺失影响了线粒体功能。结论:本研究证实了XLαs在调节颅骨发育和成骨分化中的关键作用,特别是通过影响线粒体功能来发挥其调控效应。这一发现为针对GNAS突变导致的颅骨发育异常提供了新的治疗策略,具有潜在的临床应用价值。展开更多
基金the National Natural Science Foundation of China,No.82070869 and 82270914.
文摘BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a major health burden with an increasing global incidence.Unfortunately,the unavailability of knowledge underlying NAFLD pathogenesis inhibits effective preventive and therapeutic measures.AIM To explore the molecular mechanism of NAFLD.METHODS Whole genome sequencing(WGS)analysis was performed on liver tissues from patients with NAFLD(n=6)and patients with normal metabolic conditions(n=6)to identify the target genes.A NAFLD C57BL6/J mouse model induced by 16 wk of high-fat diet feeding and a hepatocyte-specific F-box only protein 2(FBXO2)overexpression mouse model were used for in vivo studies.Plasmid transfection,co-immunoprecipitation-based mass spectrometry assays,and ubiquitination in HepG2 cells and HEK293T cells were used for in vitro studies.RESULTS A total of 30982 genes were detected in WGS analysis,with 649 up-regulated and 178 down-regulated.Expression of FBXO2,an E3 ligase,was upregulated in the liver tissues of patients with NAFLD.Hepatocyte-specific FBXO2 overexpression facilitated NAFLD-associated phenotypes in mice.Overexpression of FBXO2 aggravated odium oleate(OA)-induced lipid accumulation in HepG2 cells,resulting in an abnormal expression of genes related to lipid metabolism,such as fatty acid synthase,peroxisome proliferator-activated receptor alpha,and so on.In contrast,knocking down FBXO2 in HepG2 cells significantly alleviated the OA-induced lipid accumulation and aberrant expression of lipid metabolism genes.The hydroxyl CoA dehydrogenase alpha subunit(HADHA),a protein involved in oxidative stress,was a target of FBXO2-mediated ubiquitination.FBXO2 directly bound to HADHA and facilitated its proteasomal degradation in HepG2 and HEK293T cells.Supplementation with HADHA alleviated lipid accumulation caused by FBXO2 overexpression in HepG2 cells.CONCLUSION FBXO2 exacerbates lipid accumulation by targeting HADHA and is a potential therapeutic target for NAFLD。
基金the National Natural Science Foundation of China,No.81741103.
文摘BACKGROUND Interleukin 10 receptor alpha subunit(IL10RA)dysfunction is the main cause of very early-onset inflammatory bowel disease(VEO-IBD)in East Asians.AIM To identify disease-causing gene mutations in four patients with VEO-IBD and verify functional changes related to the disease-causing mutations.METHODS From May 2016 to September 2020,four young patients with clinically diagnosed VEO-IBD were recruited.Before hospitalization,using targeted gene panel sequencing and trio-whole-exome sequencing(WES),three patients were found to harbor a IL10RA mutation(c.301C>T,p.R101W in one patient;c.537G>A,p.T179T in two patients),but WES results of the fourth patient were not conclusive.We performed whole-genome sequencing(WGS)on patients A and B and reanalyzed the data from patients C and D.Peripheral blood mononuclear cells(PBMCs)from patient D were isolated and stimulated with lipopolysaccharide(LPS),interleukin 10(IL-10),and LPS+IL-10.Serum IL-10 levels in four patients and tumor necrosis factor-α(TNF-α)in the cell supernatant were determined by enzyme-linked immunosorbent assay.Phosphorylation of signal transducer and activator of transcription 3(STAT3)at Tyr705 and Ser727 in PBMCs was determined by western blot analysis.RESULTS The four children in our study consisted of two males and two females.The age at disease onset ranged from 18 d to 9 mo.After hospitalization,a novel 333-bp deletion encompassing exon 1 of IL10RA was found in patients A and B using WGS and was found in patients C and D after reanalysis of their WES data.Patient D was homozygous for the 333 bp deletion.All four patients had elevated serum IL-10 levels.In vitro,IL-10-stimulated PBMCs from patient D failed to induce STAT3 phosphorylation at Tyr705 and only minimally suppressed TNF-αproduction induced by LPS.Phosphorylation at Ser727 in PBMCs was not affected by LPS or LPS+IL-10 in both healthy subjects and in patient D.CONCLUSION WGS revealed a novel 333-bp deletion of IL10RA in four patients with VEO-IBD,whereas the WES results were inconclusive.
文摘BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its role in hepatocellular carcinoma(HCC)has not been fully deciphered.AIM To decipher the role of CDKN2B-AS1 in the progression of HCC.METHODS CDKN2B-AS1 expression in HCC was detected by quantitative real-time polymerase chain reaction.The malignant phenotypes of Li-7 and SNU-182 cells were detected by the CCK-8 method,EdU method,and flow cytometry,respectively.RNA immunoprecipitation was executed to confirm the interaction between CDKN2B-AS1 and E2F transcription factor 1(E2F1).Luciferase reporter assay and chromatin immunoprecipitation were performed to verify the binding of E2F1 to the promoter of G protein subunit alpha Z(GNAZ).E2F1 and GNAZ were detected by western blot in HCC cells.RESULTS In HCC tissues,CDKN2B-AS1 was upregulated.Depletion of CDKN2B-AS1 inhibited the proliferation of HCC cells,and the depletion of CDKN2B-AS1 also induced cell cycle arrest and apoptosis.CDKN2B-AS1 could interact with E2F1.Depletion of CDKN2B-AS1 inhibited the binding of E2F1 to the GNAZ promoter region.Overexpression of E2F1 reversed the biological effects of depletion of CDKN2B-AS1 on the malignant behaviors of HCC cells.CONCLUSION CDKN2B-AS1 recruits E2F1 to facilitate GNAZ transcription to promote HCC progression.
文摘DNA polymerase Ⅲ is one of the five eubacterial DNA polymerases that is responsible for the replication of DNA duplex. Among the ten subunits of the DNA polymerase Ⅲ core enzyme, the alpha subunit catalyzes the reaction for polymerizing both DNA strands. In this study, we extracted genomic sequences of the alpha subunit from 159 sequenced eubacterial genomes, and carried out sequence- based phylogenetic and structural analyses. We found that all eubacterial genomes have one or more alpha subunits, which form either homodimers or heterodimers. Phylogenetic and domain structural analyses as well as copy number variations of the alpha subunit in each bacterium indicate the classification of alpha subunit into four basic groups: polC, dnaE1, dnaE2, and dnaE3. This classification is of essence in genome composition analysis. We also consolidated the naming convention to avoid further confusion in gene annotations.
文摘Objecitve To explore whether phosphoinositide specific phospholipase C (PLC) activation via G protein in vascular smooth muscle cells (VSMCs) is altered in spontaneously hypertensive rats (SHR). Methods The VSMCs derived from aortae of SHR and Wistar Kyoto (WKY) rats were loaded for 48 hours with myo inositol. Inositol phosphate release was initiated by the addition of 10 5 mol/L norepinephrine in intact cells or by guanosine 5' 0 (3 thio tri sphosphate) (GTP gamma S) in permeabilized cells. In the meantime, growth arrested VSMCs were stimulated by 10% calf serum for 0, 30, 45, or 60 min, then gene expressions of Gq alpha subunit (G alph a q) were observed. Results There were no significant differences in inositol 1, 4,5 triphosphate (IP 3) level and expression of G alpha q mRNA between quiescent VSMCs from SHR and that from WKY. When stimulated by norepinephrine, IP 3 production increased transiently with a peak level at 10 s in VSMCs from WKY, and a rapid biphasic IP 3 response, which was significantly higher than that of WKY, in VSMCs from SHR had been observed. G proteins activated by GTP gamma S significantly raised IP 3 production in VSMCs from SHR compared to WKY (SHR vs WKY: 234.8%±29.2% vs 142.4%±12.0% of basal IP 3, P<0.05). In addition, the serum effect showed an significant increase in expression of G alpha q mRNA in VSMCs from SHR. Conclusions The hereditary factors are not the only variable regulating IP 3 metabolism and G alpha q gene expression. Influences of multi environmental factors such as vasoactive compounds, together with genetic predisposition, palys an important role in the highly sensitive response of IP 3 production and G alpha q gene over expression in SHR.
文摘目的:本研究旨在探究超大型刺激性G蛋白α亚单位(extra-large stimulatory G protein alpha subunit, XLαs)在小鼠颅骨发育和成骨分化中的功能及分子机制。方法:通过构建XLαs第一外显子敲除的小鼠模型,运用阿尔新蓝茜素红染色技术分析颅骨表型变化。从小鼠颅骨中分离原代颅骨成骨细胞,进行体外培养并诱导成骨分化,同时通过实时荧光定量聚合酶链反应和RNA测序技术对基因表达及其功能进行分析。结果:实验结果显示,XLαs敲除小鼠颅缝宽度增加(P<0.05),颅骨未矿化区域明显增多(P<0.001),且成骨分化能力受抑制(P<0.01)。RNA测序进一步揭示XLαs缺失影响了线粒体功能。结论:本研究证实了XLαs在调节颅骨发育和成骨分化中的关键作用,特别是通过影响线粒体功能来发挥其调控效应。这一发现为针对GNAS突变导致的颅骨发育异常提供了新的治疗策略,具有潜在的临床应用价值。
