Background:Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-related deaths globally.Splicing factor proline and glutamine-rich(SFPQ)is a multifunctional protein that controls various biological funct...Background:Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-related deaths globally.Splicing factor proline and glutamine-rich(SFPQ)is a multifunctional protein that controls various biological functions.As a potential therapeutic target and a promising prognostic indicator,the potential effects and processes of SFPQ in HCC require further investigation.Methods:The RNA sequencing data were obtained from the Gene Expression Omnibus,International Cancer Genome Consortium,and The Cancer Genome Atlas databases to analyze SFPQ expression and differentially expressed genes(DEGs).We utilized the LinkedOmics database to identify co-expressed genes.A Venn diagram was constructed to determine the overlapping genes between the DEGs and the co-expressed genes.Functional enrichment analysis was performed on the overlapping genes and DEGs.Furthermore,our study involved functional enrichment analysis,a protein-protein interaction network analysis,and an analysis of immune cell infiltration.The cBioPortal and Tumor Immune Single-cell Hub were utilized to investigate the genetic alterations of SFPQ and the single-cell transcriptome visualization of the tumor microenvironment.A ceRNA network was established with the assistance of the ENCORI website.Finally,we elucidated the clinical significance of SFPQ in HCC by employing Kaplan-Meier survival analysis,univariate and multivariate Cox regression,and prognostic nomogram models.Results:The expression of SFPQ in HCC tissues was significantly elevated compared to normal tissues.GSEA results indicated that increased expression of SFPQ was associated with pathways related to HCC.The ceRNA network,including SFPQ,hsa-miR-101-3p,AC023043.4,AC124798.1,AC145207.5,and GSEC,was constructed with the assistance of ENCORI.High SFPQ expression was related to a poor prognosis in HCC and its subtypes.Univariate and multivariate Cox regression analysis showed that elevated SFPQ expression is an independent predictive factor.Conclusions:The overexpression of SFPQ may serve as a potential prognostic biomarker,indicating a poor prognosis in HCC.展开更多
Alternative splicing is the process of producing variably spliced mRNAs by choosing distinct combinations of splice sites within a messenger RNA precursor.This splicing enables mRNA from a single gene to synthesize di...Alternative splicing is the process of producing variably spliced mRNAs by choosing distinct combinations of splice sites within a messenger RNA precursor.This splicing enables mRNA from a single gene to synthesize different proteins,which have different cellular properties and functions and yet arise from the same single gene.A family of splicing factors,Serine-arginine rich proteins,are needed to initiate the assembly and activation of the spliceosome.Serine and arginine rich splicing factor 1,part of the arginine/serine-rich splicing factor protein family,can either activate or inhibit the splicing of mRNAs,depending on the phosphorylation status of the protein and its interaction partners.Considering that serine and arginine rich splicing factor 1 is either an activator or an inhibitor,this protein has been studied widely to identify its various roles in different diseases.Research has found that serine and arginine rich splicing factor 1 is a key target for neuroprotection,showing its promising potential use in therapeutics for neurodegenerative disorders.Furthermore,serine and arginine rich splicing factor 1 might be used to regulate cancer development and autoimmune diseases.In this review,we highlight how serine and arginine rich splicing factor 1 has been studied concerning neuroprotection.In addition,we draw attention to how serine and arginine rich splicing factor 1 is being studied in cancer and immunological disorders,as well as how serine and arginine rich splicing factor 1 acts outside the central or peripheral nervous system.展开更多
Glial cell line-derived neurotrophic factor(GDNF) plays a critical role in neuronal survival and function. GDNF has two major splice variants in the brain,α-pro-GDNF and β-pro-GDNF, and both isoforms have strong neu...Glial cell line-derived neurotrophic factor(GDNF) plays a critical role in neuronal survival and function. GDNF has two major splice variants in the brain,α-pro-GDNF and β-pro-GDNF, and both isoforms have strong neuroprotective effects on dopamine neurons. However, the expression of the GDNF splice variants in dopaminergic neurons in the brain remains unclear. Therefore, in this study, we investigated the mRNA and protein expression of α-and β-pro-GDNF in the mouse brain by real-time quantitative polymerase chain reaction, using splice variant-specific primers, and western blot analysis. At the mRNA level,β-pro-GDNF expression was significantly greater than that of α-pro-GDNF in the mouse brain. In contrast, at the protein level,α-pro-GDNF expression was markedly greater than that of β-pro-GDNF. To clarify the mechanism underlying this inverse relationship in mRNA and protein expression levels of the GDNF splice variants, we analyzed the expression of sorting protein-related receptor with A-type repeats(SorLA) by real-time quantitative polymerase chain reaction. At the mRNA level, SorLA was positively associated with β-pro-GDNF expression, but not with α-pro-GDNF expression. This suggests that the differential expression of α-and β-pro-GDNF in the mouse brain is related to SorLA expression. As a sorting protein, SorLA could contribute to the inverse relationship among the mRNA and protein levels of the GDNF isoforms. This study was approved by the Animal Ethics Committee of Xuzhou Medical University, China on July 14, 2016.展开更多
Serine/arginine-rich splicing factor 1(SRSF1), as a prototype member of the highly conserved serine/arginine family of RNA binding proteins, plays an important role in mRNA alternative splicing, stabilization, nuclear...Serine/arginine-rich splicing factor 1(SRSF1), as a prototype member of the highly conserved serine/arginine family of RNA binding proteins, plays an important role in mRNA alternative splicing, stabilization, nuclear export, and translation. Here, the expression system was established to purify full-length human SRSF1 from Escherichia coli(E. coli). The SRSF1 coding sequence was amplified by polymerase chain reaction(PCR) and inserted into the pET-28 a-ppSUMO vector with His-tag to construct a recombinant plasmid His-SUMO-SRSF1. Then the plasmid was transformed into BL21(DE3) competent cells for expression. After purification by affinity chromatography and cleavage of His-SUMO moiety, a highly purified SRSF1 with a molecular weight of around 28 kg/mol was obtained. The protein was analyzed by sizing chromatography and it was found that SRSF1 would form a polymer structure in the solution. According to Expasy bioinformatics analysis, SRSF1 is extremely unstable. Purification of full-length SRSF1 protein provides an opportunity to study mRNA splicing in vitro.展开更多
Background: Extrinsic aging results from environmental stressors such as UVR or pollutants. While the effects of single pollutants are better understood, those of their combination remain poorly scrutinized. Objective...Background: Extrinsic aging results from environmental stressors such as UVR or pollutants. While the effects of single pollutants are better understood, those of their combination remain poorly scrutinized. Objective: Building on a study showing downregulation of several processes upon co-exposure to B[a]P and UVA, we investigated changes induced by epigenetic marks. Materials and Methods: Human primary fibroblasts and HaCaT cells were exposed to B[a]P and UVA. After 24 hours, exposed and unexposed cells were compared to assess DNA methylation. Focusing on HaCaT, multiplex assays enabled quantifying histone H3 modifications and evaluating four splicing factors (SRSF1, SRSF3, SFPQ, and SF3B1) by immunohistochemical labeling. The expression of keratinocyte-/fibroblast-relevant genes was assessed by RT-qPCR. Finally, the impact of an Arundo donax L. extract added 24 hours before B[a]P-UVA co-exposure was analyzed. Results: Exposure to B[a]P-UVA raised DNA methylation (HaCaT: ×3.6, fibroblasts: ×1.9), an increase prevented by the extract. In HaCaT cells, B[a]P-UVA increases the frequency of S10P (+38%). When exposure was preceded by extract treatment, the frequency of several methylations was impacted. B[a]P-UVA only induced the expression of SRSF1 and SFPQ in HaCaT (+46% and +34%). Treatment with the extract abolished this effect. Co-exposure increases the expression of inflammation-related genes (IL-1α, IL-1β) in HaCaT cells and decreases those of AQP3, KRT15, and SOD2. The extract has little effect on these changes. In primary fibroblasts, exposure to B[a]P-UVA lowered the expression of LOXL2, LUM, and TGFBR2 (−38%, −59%, and −51%, respectively), and the extract did not affect these modifications. Conclusion: Within 24 hours, a single B[a]P-UVA co-exposure changes epigenetic marks of skin cells but has only mild effects on gene expression. An Arundo donax L. extract can prevent part of the epigenetic marks’ changes and could stimulate the expression of some genes in primary fibroblasts.展开更多
文摘Background:Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-related deaths globally.Splicing factor proline and glutamine-rich(SFPQ)is a multifunctional protein that controls various biological functions.As a potential therapeutic target and a promising prognostic indicator,the potential effects and processes of SFPQ in HCC require further investigation.Methods:The RNA sequencing data were obtained from the Gene Expression Omnibus,International Cancer Genome Consortium,and The Cancer Genome Atlas databases to analyze SFPQ expression and differentially expressed genes(DEGs).We utilized the LinkedOmics database to identify co-expressed genes.A Venn diagram was constructed to determine the overlapping genes between the DEGs and the co-expressed genes.Functional enrichment analysis was performed on the overlapping genes and DEGs.Furthermore,our study involved functional enrichment analysis,a protein-protein interaction network analysis,and an analysis of immune cell infiltration.The cBioPortal and Tumor Immune Single-cell Hub were utilized to investigate the genetic alterations of SFPQ and the single-cell transcriptome visualization of the tumor microenvironment.A ceRNA network was established with the assistance of the ENCORI website.Finally,we elucidated the clinical significance of SFPQ in HCC by employing Kaplan-Meier survival analysis,univariate and multivariate Cox regression,and prognostic nomogram models.Results:The expression of SFPQ in HCC tissues was significantly elevated compared to normal tissues.GSEA results indicated that increased expression of SFPQ was associated with pathways related to HCC.The ceRNA network,including SFPQ,hsa-miR-101-3p,AC023043.4,AC124798.1,AC145207.5,and GSEC,was constructed with the assistance of ENCORI.High SFPQ expression was related to a poor prognosis in HCC and its subtypes.Univariate and multivariate Cox regression analysis showed that elevated SFPQ expression is an independent predictive factor.Conclusions:The overexpression of SFPQ may serve as a potential prognostic biomarker,indicating a poor prognosis in HCC.
文摘Alternative splicing is the process of producing variably spliced mRNAs by choosing distinct combinations of splice sites within a messenger RNA precursor.This splicing enables mRNA from a single gene to synthesize different proteins,which have different cellular properties and functions and yet arise from the same single gene.A family of splicing factors,Serine-arginine rich proteins,are needed to initiate the assembly and activation of the spliceosome.Serine and arginine rich splicing factor 1,part of the arginine/serine-rich splicing factor protein family,can either activate or inhibit the splicing of mRNAs,depending on the phosphorylation status of the protein and its interaction partners.Considering that serine and arginine rich splicing factor 1 is either an activator or an inhibitor,this protein has been studied widely to identify its various roles in different diseases.Research has found that serine and arginine rich splicing factor 1 is a key target for neuroprotection,showing its promising potential use in therapeutics for neurodegenerative disorders.Furthermore,serine and arginine rich splicing factor 1 might be used to regulate cancer development and autoimmune diseases.In this review,we highlight how serine and arginine rich splicing factor 1 has been studied concerning neuroprotection.In addition,we draw attention to how serine and arginine rich splicing factor 1 is being studied in cancer and immunological disorders,as well as how serine and arginine rich splicing factor 1 acts outside the central or peripheral nervous system.
基金supported by the National Natural Science Foundation of China,No.81772688(to DSG)the Postdoctoral Science Foundation of Jiangsu Province of China,No.1202119C(to HL)
文摘Glial cell line-derived neurotrophic factor(GDNF) plays a critical role in neuronal survival and function. GDNF has two major splice variants in the brain,α-pro-GDNF and β-pro-GDNF, and both isoforms have strong neuroprotective effects on dopamine neurons. However, the expression of the GDNF splice variants in dopaminergic neurons in the brain remains unclear. Therefore, in this study, we investigated the mRNA and protein expression of α-and β-pro-GDNF in the mouse brain by real-time quantitative polymerase chain reaction, using splice variant-specific primers, and western blot analysis. At the mRNA level,β-pro-GDNF expression was significantly greater than that of α-pro-GDNF in the mouse brain. In contrast, at the protein level,α-pro-GDNF expression was markedly greater than that of β-pro-GDNF. To clarify the mechanism underlying this inverse relationship in mRNA and protein expression levels of the GDNF splice variants, we analyzed the expression of sorting protein-related receptor with A-type repeats(SorLA) by real-time quantitative polymerase chain reaction. At the mRNA level, SorLA was positively associated with β-pro-GDNF expression, but not with α-pro-GDNF expression. This suggests that the differential expression of α-and β-pro-GDNF in the mouse brain is related to SorLA expression. As a sorting protein, SorLA could contribute to the inverse relationship among the mRNA and protein levels of the GDNF isoforms. This study was approved by the Animal Ethics Committee of Xuzhou Medical University, China on July 14, 2016.
基金Shanghai Science and Technology Commission’s “Belt and Road Initiative International Cooperation Project”,China (No.19410741800)。
文摘Serine/arginine-rich splicing factor 1(SRSF1), as a prototype member of the highly conserved serine/arginine family of RNA binding proteins, plays an important role in mRNA alternative splicing, stabilization, nuclear export, and translation. Here, the expression system was established to purify full-length human SRSF1 from Escherichia coli(E. coli). The SRSF1 coding sequence was amplified by polymerase chain reaction(PCR) and inserted into the pET-28 a-ppSUMO vector with His-tag to construct a recombinant plasmid His-SUMO-SRSF1. Then the plasmid was transformed into BL21(DE3) competent cells for expression. After purification by affinity chromatography and cleavage of His-SUMO moiety, a highly purified SRSF1 with a molecular weight of around 28 kg/mol was obtained. The protein was analyzed by sizing chromatography and it was found that SRSF1 would form a polymer structure in the solution. According to Expasy bioinformatics analysis, SRSF1 is extremely unstable. Purification of full-length SRSF1 protein provides an opportunity to study mRNA splicing in vitro.
文摘Background: Extrinsic aging results from environmental stressors such as UVR or pollutants. While the effects of single pollutants are better understood, those of their combination remain poorly scrutinized. Objective: Building on a study showing downregulation of several processes upon co-exposure to B[a]P and UVA, we investigated changes induced by epigenetic marks. Materials and Methods: Human primary fibroblasts and HaCaT cells were exposed to B[a]P and UVA. After 24 hours, exposed and unexposed cells were compared to assess DNA methylation. Focusing on HaCaT, multiplex assays enabled quantifying histone H3 modifications and evaluating four splicing factors (SRSF1, SRSF3, SFPQ, and SF3B1) by immunohistochemical labeling. The expression of keratinocyte-/fibroblast-relevant genes was assessed by RT-qPCR. Finally, the impact of an Arundo donax L. extract added 24 hours before B[a]P-UVA co-exposure was analyzed. Results: Exposure to B[a]P-UVA raised DNA methylation (HaCaT: ×3.6, fibroblasts: ×1.9), an increase prevented by the extract. In HaCaT cells, B[a]P-UVA increases the frequency of S10P (+38%). When exposure was preceded by extract treatment, the frequency of several methylations was impacted. B[a]P-UVA only induced the expression of SRSF1 and SFPQ in HaCaT (+46% and +34%). Treatment with the extract abolished this effect. Co-exposure increases the expression of inflammation-related genes (IL-1α, IL-1β) in HaCaT cells and decreases those of AQP3, KRT15, and SOD2. The extract has little effect on these changes. In primary fibroblasts, exposure to B[a]P-UVA lowered the expression of LOXL2, LUM, and TGFBR2 (−38%, −59%, and −51%, respectively), and the extract did not affect these modifications. Conclusion: Within 24 hours, a single B[a]P-UVA co-exposure changes epigenetic marks of skin cells but has only mild effects on gene expression. An Arundo donax L. extract can prevent part of the epigenetic marks’ changes and could stimulate the expression of some genes in primary fibroblasts.
