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您的检索式：作者名="Sumera Karim"
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| 1 | Hepatic expression and cellular distribution of the glucose transporter family显示文摘Glucose and other carbohydrates are transported into cells using members of a family of integral membrane glucose transporter (GLUT) molecules. To date 14 members of this family, also called the solute carrier 2A proteins have been identified which are divided on the basis of transport characteristics and sequence similarities into several families (Classes 1 to 3). The expression of these different receptor subtypes varies between different species, tissues and cellular subtypes and each has differential sensitivities to stimuli such as insulin. The liver is a contributor to metabolic carbohydrate homeostasis and is a major site for synthesis, storage and redistribution of carbohydrates. Situations in which the balance of glucose homeostasis is upset such as diabetes or the metabolic syndrome can lead metabolic disturbances that drive chronic organ damage and failure, confirming the importance of understanding the molecular regulation of hepatic glucose homeostasis. There is a considerable literature describing the expression and function of receptors that regulate glucose uptake and release by hepatocytes, the most import cells in glucose regulation and glycogen storage. However there is less appreciation of the roles of GLUTs expressed by non parenchymal cell types within the liver, all of which require carbohydrate to function. A better understanding of the detailed cellular distribution of GLUTs in human liver tissue may shed light on mechanisms underlying disease pathogenesis. This review summarises the available literature on hepatocellular expression of GLUTs in health and disease and highlights areas where further investigation is required. | Sumera Karim David H Adams Patricia F Lalor | 2012 | World Journal of Gastroenterology2012，18，46： | 5 |
| 2 | Inhibition of vascular adhesion protein-1 modifies hepatic steatosis in vitro and in vivo显示文摘BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is associated with obesity,insulin resistance and dyslipidaemia and currently is estimated to affect up to a third of all individuals in developed countries.Current standard of care for patients varies according to disease stage,but includes lifestyle interventions common insulin sensitizers,antioxidants and lipid modifiers.However,to date specific therapies have shown little histological or fibrosis stage improvement in large clinical trials,and there is still no licensed therapy for NAFLD.Given the high prevalence,limited treatment options and significant screening costs for the general population,new treatments are urgently required.AIM To assess the potential for inhibition of the amine oxidase enzyme vascular adhesion protein-1(VAP-1)to modify hepatic lipid accumulation in NAFLD.METHODS We have used immunochemical and qPCR analysis to document expression of VAP-1 and key functional proteins and transporters across the NAFLD spectrum.We then utilised hepatocytes in culture and human precision cut liver slices in concert with selective enzyme activity inhibitors to test the effects of activating the semicarbazide-sensitive amine oxidase activity of VAP-1 on hepatic lipid uptake and triglyceride export.A murine model of NAFLD was also used to determine the consequences of VAP-1 knockout and gene expression arrays were used to quantify the effects of VAP-1 activity on key lipid modifying and proinflammatory gene expression.RESULTS We confirmed that increasing severity of NAFLD and progression to cirrhosis was associated with a significant increase in hepatocellular VAP-1 expression.Hepatocytes in vitro exposed to recombinant VAP-1 and its substrate methylamine showed increased lipid accumulation as determined by quantification of Oil Red O uptake.This was recapitulated using hydrogen peroxide,and lipid accumulation was accompanied by changes in expression of the lipid transporter molecules FABP3,FATP6,insulin receptor subunits and PPARα.Human liver tissue exposed to recombinant VAP-1 or substrates for endo/exogenous VAP-1 produced less triglyceride than untreated tissue and demonstrated an increase in steatosis.This response could be inhibited by using bromoethylamine to inhibit the SSAO activity of VAP-1,and mice deficient in VAP-1/AOC3 also demonstrated reduced steatosis on high fat diet.Exposure of human liver tissue to methylamine to activate VAP-1 resulted in increased expression of FABP2 and 4,FATP3-5,caveolin-1,VLDLR,PPARGC1 and genes associated with the inflammatory response.CONCLUSION Our data confirm that the elevations in hepatic VAP-1 expression reported in nonalcoholic steatohepatitis can contribute to steatosis,metabolic disturbance and inflammation.This suggests that targeting the semicarbazide sensitive amine oxidase capacity of VAP-1 may represent a useful adjunct to other therapeutic strategies in NAFLD. | Emma L Shepherd Sumera Karim Philip N Newsome Patricia F Lalor | 2020 | World Journal of Hepatology2020，12，11： | 0 |
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