Matches in SemOpenAlex for { <https://semopenalex.org/work/W1569805454> ?p ?o ?g. }
- W1569805454 abstract "Liver and intestine are important organs for the metabolism of cholesterol and bile acids in the body. Dysfunction in cholesterol and bile acid metabolism may lead to diseases such as cholesterol gallstone (GS) disease and atherosclerosis. The projects presented in this thesis aim to gain further insights into hepatic and intestinal cholesterol and bile acid metabolism and their role in the regulation of lipoprotein metabolism. We found that: Paper I. Chinese patients with GS disease had higher mRNA expression of hepatic ABCG5, ABCG8 and LXRα, which correlated with biliary cholesterol molar percentage and cholesterol saturation index (CSI). The mRNA and protein levels of the hepatic scavenger receptor B type I (SRBI) were increased and a significant correlation was found between the protein levels and the CSI as well. The results suggest that an upregulation of ABCG5/ABCG8 in Chinese GS patients, possibly mediated by increased LXRα, may contribute to the cholesterol supersaturation of bile. The data also indicate the possibility that increased amount of biliary cholesterol may originate from HDL by an enhanced transfer via SRBI. Paper II. The intestinal mRNA expression of NPC1L1 and ACAT2 were significantly higher in Chinese GS patients than in gallstone-free (GSF) controls. Our data suggest that the increased NPC1L1 and ACAT2 mRNA levels in GS patients might indicate an upregulation of cholesterol absorption and esterification in the small intestine. Paper III. Analysis of liver biopsies from Chinese GS and GSF patients revealed strong positive correlations between NPC1L1 and SREBP2 and HNF4α mRNA. Further studies were carried out to reveal the transcriptional regulation of NPC1L1 by these transcription factors. We showed a dose-dependent regulation by SREBP2 on the NPC1L1 promoter activity and mRNA expression in HuH7 cells. Chromatin immuno-precipitation (CHIP) assay confirmed the binding of SREBP2 to the promoter in vivo. Moreover, HNF1α increased both NPC1L1 promoter activity and the gene expression, and an important HNF1α binding site (-158/-144 nt) was identified within the human NPC1L1 promoter. CHIP assays also confirmed that HNF1α binds to the NPC1L1 promoter in vivo. Paper IV. In human, hepatic microsomal ACAT2 activity was significantly lower in females than in males. Moreover, the activity of ACAT2 correlated negatively with plasma HDL cholesterol and Apo A1. This is the first description of a gender-related difference of hepatic ACAT2 activity suggesting, a possible role for ACAT2 activity in the regulation of the cholesterol metabolism in humans. The negative correlation between ACAT2 activity and HDL cholesterol or Apo A1 may reflect such regulation. Since ACAT2 activity has been found to be pro-atherogenic, the observed gender-related difference may contribute to the protection of coronary heart disease in females. Paper V. In this study, we found that female mice had significantly higher hepatic ACAT2 activity and mRNA expression and hepatic cholesteryl esters than male mice, independently of the presence/absence of estrogen receptor α (ERA) or β (ERB). The presence of ERA was associated to a higher mRNA of Acat2 in mice. Furthermore, the interaction analysis showed that in female mice, presence of ERA was associated with a higher Acat2 mRNA level. Hepatic ABCA1 protein was also lower in female mice, independently of ERA or ERB. ABCA1 protein correlated positively with the free cholesterol content in the plasma membrane and negatively with hepatic ACAT2 activity. Our data suggest that ERA seems to regulate Acat2 at the mRNA level but not the activity. The observed relation between ABCA1 protein, free cholesterol in the plasma membrane and hepatic ACAT2 activity suggest a possible regulatory pathway in mice." @default.
- W1569805454 created "2016-06-24" @default.
- W1569805454 creator A5055122741 @default.
- W1569805454 date "2010-03-26" @default.
- W1569805454 modified "2023-09-28" @default.
- W1569805454 title "Studies on cholesterol and bile acid metabolism in Chinese cholesterol gallstone patients" @default.
- W1569805454 cites W1486536093 @default.
- W1569805454 cites W1508733793 @default.
- W1569805454 cites W1510167055 @default.
- W1569805454 cites W1564537703 @default.
- W1569805454 cites W1604097175 @default.
- W1569805454 cites W1751757376 @default.
- W1569805454 cites W1832765217 @default.
- W1569805454 cites W1850214531 @default.
- W1569805454 cites W1868808302 @default.
- W1569805454 cites W188528801 @default.
- W1569805454 cites W1891689978 @default.
- W1569805454 cites W1895325632 @default.
- W1569805454 cites W1901163999 @default.
- W1569805454 cites W1918761709 @default.
- W1569805454 cites W1939555998 @default.
- W1569805454 cites W1964532888 @default.
- W1569805454 cites W1965347207 @default.
- W1569805454 cites W1966052494 @default.
- W1569805454 cites W1966374931 @default.
- W1569805454 cites W1966500936 @default.
- W1569805454 cites W1967018843 @default.
- W1569805454 cites W1970363592 @default.
- W1569805454 cites W1971899070 @default.
- W1569805454 cites W1973243569 @default.
- W1569805454 cites W1973495386 @default.
- W1569805454 cites W1974186353 @default.
- W1569805454 cites W1977504620 @default.
- W1569805454 cites W1979903836 @default.
- W1569805454 cites W1981003642 @default.
- W1569805454 cites W1985170971 @default.
- W1569805454 cites W1985425916 @default.
- W1569805454 cites W1986755882 @default.
- W1569805454 cites W1989086831 @default.
- W1569805454 cites W1990819179 @default.
- W1569805454 cites W1992305758 @default.
- W1569805454 cites W1993343317 @default.
- W1569805454 cites W1995465629 @default.
- W1569805454 cites W1998498590 @default.
- W1569805454 cites W1998600489 @default.
- W1569805454 cites W2000592725 @default.
- W1569805454 cites W2002050129 @default.
- W1569805454 cites W2002121467 @default.
- W1569805454 cites W2004930686 @default.
- W1569805454 cites W2005320735 @default.
- W1569805454 cites W2008450021 @default.
- W1569805454 cites W2012192962 @default.
- W1569805454 cites W2015354361 @default.
- W1569805454 cites W2017905787 @default.
- W1569805454 cites W2018124948 @default.
- W1569805454 cites W2020565167 @default.
- W1569805454 cites W2024806277 @default.
- W1569805454 cites W2025165872 @default.
- W1569805454 cites W2026237709 @default.
- W1569805454 cites W2027663543 @default.
- W1569805454 cites W2028943130 @default.
- W1569805454 cites W2030185339 @default.
- W1569805454 cites W2030412283 @default.
- W1569805454 cites W2031104654 @default.
- W1569805454 cites W2031142552 @default.
- W1569805454 cites W2036843552 @default.
- W1569805454 cites W2036953560 @default.
- W1569805454 cites W2039486449 @default.
- W1569805454 cites W2039999119 @default.
- W1569805454 cites W2040417680 @default.
- W1569805454 cites W2040470970 @default.
- W1569805454 cites W2042055907 @default.
- W1569805454 cites W2044250881 @default.
- W1569805454 cites W2044357450 @default.
- W1569805454 cites W2046309190 @default.
- W1569805454 cites W2046571558 @default.
- W1569805454 cites W2048954674 @default.
- W1569805454 cites W2050056124 @default.
- W1569805454 cites W2051040521 @default.
- W1569805454 cites W2053581007 @default.
- W1569805454 cites W2054267961 @default.
- W1569805454 cites W2056113150 @default.
- W1569805454 cites W2056152639 @default.
- W1569805454 cites W2057407335 @default.
- W1569805454 cites W2059256286 @default.
- W1569805454 cites W2059685472 @default.
- W1569805454 cites W2061569374 @default.
- W1569805454 cites W2063896047 @default.
- W1569805454 cites W2065004025 @default.
- W1569805454 cites W2066637705 @default.
- W1569805454 cites W2068458442 @default.
- W1569805454 cites W2070176327 @default.
- W1569805454 cites W2071124826 @default.
- W1569805454 cites W2071450296 @default.
- W1569805454 cites W2072385680 @default.
- W1569805454 cites W2072787342 @default.
- W1569805454 cites W2072993881 @default.
- W1569805454 cites W2073308465 @default.
- W1569805454 cites W2073883348 @default.
- W1569805454 cites W2078922491 @default.