| 1. |
- Mwinyi, Jessica, et al.
(författare)
-
NAFLD is associated with methylation shifts with relevance for the expression of genes involved in lipoprotein particle composition
- 2017
-
Ingår i: Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids. - : Elsevier BV. - 1388-1981 .- 1879-2618. ; 1862:3, s. 314-323
-
Tidskriftsartikel (refereegranskat)abstract
- Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of triglycerides, cholesterol and toxic free fatty acids and is related to low vitamin D levels. In an analysis of specific gene sets we elucidate to what extent NAFLD associates to epigenetic and related transcriptional changes in gene networks regulating lipid, energy and vitamin D balance. Two gene clusters responsible for lipid homeostasis (74 genes) and vitamin D and energy balance (31 genes) were investigated with regard to average epigenetic shifts within the first 1500 bp next to the transcriptional start site. Three cohorts from two published genome wide driven studies that used a microarray approach were investigated including altogether 103 NAFLD and 75 liver healthy subjects. In the first two steps associations between NAFLD abundance, strength of fibrosis and methylation were investigated in two cohorts by multiple linear regression analyses, correcting for important clinical and demographic parameters. Methylation associated strength of transcription in genes showing significant NAFLD related methylation changes were studied in a third step using a third cohort and applying Pearson's correlation and robust linear regression analyses. 41 genes in gene cluster 1 and 14 genes in cluster 2 were significantly differentially methylated in dependency of NAFLD and hepatic fibrosis. We detect new genes significantly changed in methylation, including APO family members (lipid transport), NPC1L1, STARD (cholesterol transport) and GRHL (energy homeostasis). Our results allow novel insights into the hepatic epigenetic regulation of genes important for lipid and vitamin D balance in NAFLD.
|
|
| 2. |
- Schiöth, Helgi B., et al.
(författare)
-
A targeted analysis reveals relevant shifts in the methylation and transcription of genes responsible for bile acid homeostasis and drug metabolism in non-alcoholic fatty liver disease
- 2016
-
Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 17
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Non-alcoholic fatty liver disease (NAFLD) is associated with a high risk for liver cirrhosis and cancer. Recent studies demonstrate that NAFLD significantly impacts on the genome wide methylation and expression reporting top hit genes to be associated with e.g. diabetes mellitus. In a targeted analysis we specifically investigate to what extent NAFLD is associated with methylation and transcriptional changes in gene networks responsible for drug metabolism (DM) and bile acid (BA) homeostasis, which may trigger liver and system toxic events. Methods: We performed a systematic analysis of 73 genes responsible for BA homeostasis and DM based on liver derived methylation and expression data from three cohort studies including 103 NAFLD and 75 non-NAFLD patients. Using multiple linear regression models, we detected methylation differences in proximity to the transcriptional start site of these genes in two NAFLD cohorts and correlated the methylation of significantly changed CpG sites to transcriptional expression in a third cohort using robust multiple linear regression approaches. Results: We detected 64 genes involved in BA homeostasis and DM to be significantly differentially methylated. In 26 of these genes, methylation significantly correlated with RNA expression, detecting i.e. genes such as CYP27A1, OST alpha, and SLC27A5 (BA homeostasis), and SLCO2B1, SLC47A1, and several UGT and CYP genes (DM) to be NAFLD dependently modulated. Conclusions: NAFLD is associated with significant shifts in the methylation of key genes responsible for BA and DM that are associated with transcriptional modulations. These findings have implications for BA composition, BA regulated metabolic pathways and for drug safety and efficacy.
|
|
