Although new research technologies are constantly used to look either for genes or biomarkers in the prediction of metabolic syndrome(MS),the pathogenesis and pathophysiology of this complex disease remains a major ch...Although new research technologies are constantly used to look either for genes or biomarkers in the prediction of metabolic syndrome(MS),the pathogenesis and pathophysiology of this complex disease remains a major challenge.Interestingly,Cheng et al recently investigated possible pathways underlying MS by high-throughput metabolite profiling in two large and well characterized community-based cohorts.The authors explored by liquid chromatography and mass spectrometry the plasma concentrations of 45 distinct metabolites and examined their relation to cardiometabolic risk,and observed that metabolic risk factors such as obesity,insulin resistance(IR),high blood pressure,and dyslipidemia were associated with several metabolites,including branched-chain amino acids,other hydrophobic amino acids,tryptophan breakdown products,and nucleotide metabolites.In addition,the authors found a significant association of IR traits with glutamine,glutamate and the glutamineto-glutamate ratio.These data provide new insight into the pathogenesis of MS-associated phenotypes and introduce a crucial role of glutamine-cycling pathway as prominently involved in the development of metabolic risk.We consider that the hypothesis about the role of abnormal glutamate metabolism in the pathogenesis of the MS is certainly challenging and suggests the critical role of the liver in the global metabolic modulation as glutamate metabolism is linked with aminotransferase reactions.We discuss here the critical role of the "liver metabolism" in the pathogenesis of the MS and IR,and postulate that before fatty liver develops,abnormal levels of liver enzymes,such as alanine and aspartate aminotransferases might reflect high levels of hepatic transamination of amino acids in the liver.展开更多
For several decades,serum levels of alanine(ALT) and aspartate(AST) aminotransferases have been regarded as markers of liver injury,including a wide range of etiologies from viral hepatitis to fatty liver.The increasi...For several decades,serum levels of alanine(ALT) and aspartate(AST) aminotransferases have been regarded as markers of liver injury,including a wide range of etiologies from viral hepatitis to fatty liver.The increasing worldwide prevalence of metabolic syndrome and cardiovascular disease revealed that transaminases are strong predictors of type 2 diabetes,coronary heart disease,atherothrombotic risk profile,and overall risk of metabolic disease.Therefore,it is plausible to suggest that aminotransferases are surrogate biomarkers of "liver metabolic functioning" beyond the classical concept of liver cellular damage,as their enzymatic activity might actually reflect key aspects of the physiology and pathophysiology of the liver function.In this study,we summarize the background information and recent findings on the biological role of ALT and AST,and review the knowledge gained from the application of genome-wide approaches and "omics" technologies that uncovered new concepts on the role of aminotransferases in human diseases and systemic regulation of metabolic functions.Prediction of biomolecular interactions between the candidate genes recently discovered to be associated with plasma concentrations of liver enzymes showed interesting interconnectivity nodes,which suggest that regulation of aminotransferase activity is a complex and highly regulated trait.Finally,links between aminotransferase genes and metabolites are explored to understand the genetic contributions to the metabolic diversity.展开更多
This review intends to uncover how information from large-scale genetic profiling(whole genome sequencing, and whole exome sequencing) of nonalcoholic fatty liver disease(NAFLD), as well as information from circulatin...This review intends to uncover how information from large-scale genetic profiling(whole genome sequencing, and whole exome sequencing) of nonalcoholic fatty liver disease(NAFLD), as well as information from circulating transcriptomics(cell-free mi RNAs) and metabolomics, contributes to the understanding of NAFLD pathogenesis. A further aim is to address the question of whether OMICs information is ready to be implemented in the clinics. The available evidence suggests that any new knowledge pertaining to molecular signatures associated with NAFLD and nonalcoholic steatohepatitis should be promptly translated into the clinical setting. Nevertheless, rigorous steps that must include validation and replication are mandatory before utilizing OMICs biomarkers in diagnostics to identify patients at risk of advanced disease, including liver cancer.展开更多
Genome-wide and candidate gene association studies have identified several variants that predispose individuals to developing nonalcoholic fatty liver disease(NAFLD).However,the gene that has been consistently involve...Genome-wide and candidate gene association studies have identified several variants that predispose individuals to developing nonalcoholic fatty liver disease(NAFLD).However,the gene that has been consistently involved in the genetic susceptibility of NAFLD in humans is patatin-like phospholipase domain containing 3(PNPLA3,also known as adiponutrin).A nonsynonymous single nucleotide polymorphism in PNPLA3(rs738409 C/G,a coding variant that encodes an amino acid substitution I148M) is significantly associated with fatty liver and histological disease severity,not only in adults but also in children.Nevertheless,how PNPLA3 influences the biology of fatty liver disease is still an open question.A recent article describes new aspects about PNPLA3 gene/protein function and suggests that the I148M variant promotes hepatic lipid synthesis due to a gain of function.We revise here the published data about the role of the I148M variant in lipogenesis/lipolysis,and suggest putative areas of future research.For instance we explored in silico whether the rs738409 C or G alleles have the ability to modify miRNA binding sites and miRNA gene regulation,and we found that prediction of PNPLA3 target miRNAs shows two miRNAs potentially interacting in the 3' UTR region(hsa-miR-769-3p and hsa-miR-516a-3p).In addition,interesting unanswered questions remain to be explored.For example,PNPLA3 lies between two CCCTC-binding factor-bound sites that could be tested for insulator activity,and an intronic histone 3 lysine 4 trimethylation peak predicts an enhancer element,corroborated by the DNase Ⅰ hypersensitivity site peak.Finally,an interaction between PNPLA3 and glycerol3-phosphate acyltransferase 2 is suggested by data miming.展开更多
The pathogenesis of intrahepatic cholestasis of pregnancy (ICP), a disorder that adversely affects maternal wellbeing and fetal outcome, is unclear. However, multiple factors probably interact along with a genetic pre...The pathogenesis of intrahepatic cholestasis of pregnancy (ICP), a disorder that adversely affects maternal wellbeing and fetal outcome, is unclear. However, multiple factors probably interact along with a genetic predisposition. We would like to add some comments on a paper recently published concerning the role of ABCB11 and ABCC2 polymorphisms in both ICP and contraceptive-induced cholestasis, especially in the light of our recently published findings about a positive association between ICP and ABCC2 common variants.展开更多
Nonalcoholic fatty liver disease(NAFLD) is a complex disorder that has evolved in recent years as the leading global cause of chronic liver damage. The main obstacle to better disease management pertains to the lack o...Nonalcoholic fatty liver disease(NAFLD) is a complex disorder that has evolved in recent years as the leading global cause of chronic liver damage. The main obstacle to better disease management pertains to the lack of approved pharmacological interventions for the treatment of nonalcoholic steatohepatitis(NASH) and NASH-fibrosis-the severe histological forms. Over the past decade,tremendous advances have been made in NAFLD research, resulting in the discovery of disease mechanisms and novel therapeutic targets. Hence, a large number of pharmacological agents are currently being tested for safety and efficacy. These drugs are in the initial pharmacological phases(phase 1 and 2),which involve testing tolerability, therapeutic action, and pharmacological issues.It is thus reasonable to assume that the next generation of NASH drugs will not be available for clinical use for foreseeable future. The expected delay can be mitigated by drug repurposing or repositioning, which essentially relies on identifying and developing new uses for existing drugs. Here, we propose a drug candidate selection method based on the integration of molecular pathways of disease pathogenesis into network analysis tools that use OMICs data as well as multiples sources, including text mining from the medical literature.展开更多
基金Supported by Grants PICT 2008-1521 and 2010-0441,from Agencia Nacional de Promoción Científica y TecnológicaUBACYT CM04,from Universidad de Buenos Aires
文摘Although new research technologies are constantly used to look either for genes or biomarkers in the prediction of metabolic syndrome(MS),the pathogenesis and pathophysiology of this complex disease remains a major challenge.Interestingly,Cheng et al recently investigated possible pathways underlying MS by high-throughput metabolite profiling in two large and well characterized community-based cohorts.The authors explored by liquid chromatography and mass spectrometry the plasma concentrations of 45 distinct metabolites and examined their relation to cardiometabolic risk,and observed that metabolic risk factors such as obesity,insulin resistance(IR),high blood pressure,and dyslipidemia were associated with several metabolites,including branched-chain amino acids,other hydrophobic amino acids,tryptophan breakdown products,and nucleotide metabolites.In addition,the authors found a significant association of IR traits with glutamine,glutamate and the glutamineto-glutamate ratio.These data provide new insight into the pathogenesis of MS-associated phenotypes and introduce a crucial role of glutamine-cycling pathway as prominently involved in the development of metabolic risk.We consider that the hypothesis about the role of abnormal glutamate metabolism in the pathogenesis of the MS is certainly challenging and suggests the critical role of the liver in the global metabolic modulation as glutamate metabolism is linked with aminotransferase reactions.We discuss here the critical role of the "liver metabolism" in the pathogenesis of the MS and IR,and postulate that before fatty liver develops,abnormal levels of liver enzymes,such as alanine and aspartate aminotransferases might reflect high levels of hepatic transamination of amino acids in the liver.
基金Supported by(in part)Grants PICT 2010-0441 and PICT 2012-0159(Agencia Nacional de Promoción Científica y Tecnológica)and UBACYT CM04(Universidad de Buenos Aires)
文摘For several decades,serum levels of alanine(ALT) and aspartate(AST) aminotransferases have been regarded as markers of liver injury,including a wide range of etiologies from viral hepatitis to fatty liver.The increasing worldwide prevalence of metabolic syndrome and cardiovascular disease revealed that transaminases are strong predictors of type 2 diabetes,coronary heart disease,atherothrombotic risk profile,and overall risk of metabolic disease.Therefore,it is plausible to suggest that aminotransferases are surrogate biomarkers of "liver metabolic functioning" beyond the classical concept of liver cellular damage,as their enzymatic activity might actually reflect key aspects of the physiology and pathophysiology of the liver function.In this study,we summarize the background information and recent findings on the biological role of ALT and AST,and review the knowledge gained from the application of genome-wide approaches and "omics" technologies that uncovered new concepts on the role of aminotransferases in human diseases and systemic regulation of metabolic functions.Prediction of biomolecular interactions between the candidate genes recently discovered to be associated with plasma concentrations of liver enzymes showed interesting interconnectivity nodes,which suggest that regulation of aminotransferase activity is a complex and highly regulated trait.Finally,links between aminotransferase genes and metabolites are explored to understand the genetic contributions to the metabolic diversity.
基金Supported by Agencia Nacional de Promoción Científicay Tecnológica,No.PICT 2014-0432,No.PICT 2014-1816 and No.PICT 2015-0551
文摘This review intends to uncover how information from large-scale genetic profiling(whole genome sequencing, and whole exome sequencing) of nonalcoholic fatty liver disease(NAFLD), as well as information from circulating transcriptomics(cell-free mi RNAs) and metabolomics, contributes to the understanding of NAFLD pathogenesis. A further aim is to address the question of whether OMICs information is ready to be implemented in the clinics. The available evidence suggests that any new knowledge pertaining to molecular signatures associated with NAFLD and nonalcoholic steatohepatitis should be promptly translated into the clinical setting. Nevertheless, rigorous steps that must include validation and replication are mandatory before utilizing OMICs biomarkers in diagnostics to identify patients at risk of advanced disease, including liver cancer.
基金Supported by Grants PICT 2008-1521 and PICT 2010 0441,from National Agency for Science and TechnologyUBACYT CM04,from Universidad de Buenos AiresSookoian S and Pirola CJ belong to National Council of Scientific and Technical Research
文摘Genome-wide and candidate gene association studies have identified several variants that predispose individuals to developing nonalcoholic fatty liver disease(NAFLD).However,the gene that has been consistently involved in the genetic susceptibility of NAFLD in humans is patatin-like phospholipase domain containing 3(PNPLA3,also known as adiponutrin).A nonsynonymous single nucleotide polymorphism in PNPLA3(rs738409 C/G,a coding variant that encodes an amino acid substitution I148M) is significantly associated with fatty liver and histological disease severity,not only in adults but also in children.Nevertheless,how PNPLA3 influences the biology of fatty liver disease is still an open question.A recent article describes new aspects about PNPLA3 gene/protein function and suggests that the I148M variant promotes hepatic lipid synthesis due to a gain of function.We revise here the published data about the role of the I148M variant in lipogenesis/lipolysis,and suggest putative areas of future research.For instance we explored in silico whether the rs738409 C or G alleles have the ability to modify miRNA binding sites and miRNA gene regulation,and we found that prediction of PNPLA3 target miRNAs shows two miRNAs potentially interacting in the 3' UTR region(hsa-miR-769-3p and hsa-miR-516a-3p).In addition,interesting unanswered questions remain to be explored.For example,PNPLA3 lies between two CCCTC-binding factor-bound sites that could be tested for insulator activity,and an intronic histone 3 lysine 4 trimethylation peak predicts an enhancer element,corroborated by the DNase Ⅰ hypersensitivity site peak.Finally,an interaction between PNPLA3 and glycerol3-phosphate acyltransferase 2 is suggested by data miming.
文摘The pathogenesis of intrahepatic cholestasis of pregnancy (ICP), a disorder that adversely affects maternal wellbeing and fetal outcome, is unclear. However, multiple factors probably interact along with a genetic predisposition. We would like to add some comments on a paper recently published concerning the role of ABCB11 and ABCC2 polymorphisms in both ICP and contraceptive-induced cholestasis, especially in the light of our recently published findings about a positive association between ICP and ABCC2 common variants.
文摘Nonalcoholic fatty liver disease(NAFLD) is a complex disorder that has evolved in recent years as the leading global cause of chronic liver damage. The main obstacle to better disease management pertains to the lack of approved pharmacological interventions for the treatment of nonalcoholic steatohepatitis(NASH) and NASH-fibrosis-the severe histological forms. Over the past decade,tremendous advances have been made in NAFLD research, resulting in the discovery of disease mechanisms and novel therapeutic targets. Hence, a large number of pharmacological agents are currently being tested for safety and efficacy. These drugs are in the initial pharmacological phases(phase 1 and 2),which involve testing tolerability, therapeutic action, and pharmacological issues.It is thus reasonable to assume that the next generation of NASH drugs will not be available for clinical use for foreseeable future. The expected delay can be mitigated by drug repurposing or repositioning, which essentially relies on identifying and developing new uses for existing drugs. Here, we propose a drug candidate selection method based on the integration of molecular pathways of disease pathogenesis into network analysis tools that use OMICs data as well as multiples sources, including text mining from the medical literature.