Project description:We analyzed the transcriptome for drug metabolism genes of 35 human (17 healthy control (HC), and 18 nonalcoholic fatty liver disease (NAFLD)) liver tissues, obtained during laparoscopic cholecystectomy. The aim of our study is to identify the drug metabolism genes significantly regulated by NAFLD at the transcriptome level.
Project description:In pigs, adipose tissue is one of the principal organs involved in the regulation of lipid metabolism. It is particulary involved in the overall fatty acid synthesis with consequences in other lipid-target organs such as muscles and the liver. With this in mind, we have used massive, parallel high-throughput sequencing technologies to characterize the porcine adipose tissue transcriptome architecture in six Iberian x Landrace crossbred pigs showing extreme phenotypes for intramuscular fatty acid composition (three per group). High-throughput RNA sequencing was used to generate a whole characterization of adipose tissue (backfat) transcriptome. A total of 4,130 putative unannotated protein-coding sequences were identified in the 20% of reads which mapped in intergenic regions. Furthermore, 36% of the unmapped reads were represented by interspersed repeats, SINEs being the most abundant elements. Differential expression analyses identified 396 candidate genes among divergent animals for intramuscular fatty acid composition. Sixty-two percent of these genes (247/396) presented higher expression in the group of pigs with higher content of intramuscular SFA and MUFA, while the remaining 149 showed higher expression in the group with higher content of PUFA. Pathway analysis related these genes to biological functions and canonical pathways controlling lipid and fatty acid metabolisms. In concordance with the phenotypic classification of animals, the major metabolic pathway differentially modulated between groups was de novo lipogenesis, the group with more PUFA being the one that showed lower expression of lipogenic genes. These results will help in the identification of genetic variants at loci that affect fatty acid composition traits. The implications of these results range from the improvement of porcine meat quality traits to the application of the pig as an animal model of human metabolic diseases. The supplementary files contains the five arrays reported in the paper. Backfat from five animals were assayed with high-density oligonucleotide microarray chips (GeneChipM-BM-. Porcine) from Affymetrix, in order to validate RNA-Seq data.
Project description:In pigs, adipose tissue is one of the principal organs involved in the regulation of lipid metabolism. It is particulary involved in the overall fatty acid synthesis with consequences in other lipid-target organs such as muscles and the liver. With this in mind, we have used massive, parallel high-throughput sequencing technologies to characterize the porcine adipose tissue transcriptome architecture in six Iberian x Landrace crossbred pigs showing extreme phenotypes for intramuscular fatty acid composition (three per group). High-throughput RNA sequencing was used to generate a whole characterization of adipose tissue (backfat) transcriptome. A total of 4,130 putative unannotated protein-coding sequences were identified in the 20% of reads which mapped in intergenic regions. Furthermore, 36% of the unmapped reads were represented by interspersed repeats, SINEs being the most abundant elements. Differential expression analyses identified 396 candidate genes among divergent animals for intramuscular fatty acid composition. Sixty-two percent of these genes (247/396) presented higher expression in the group of pigs with higher content of intramuscular SFA and MUFA, while the remaining 149 showed higher expression in the group with higher content of PUFA. Pathway analysis related these genes to biological functions and canonical pathways controlling lipid and fatty acid metabolisms. In concordance with the phenotypic classification of animals, the major metabolic pathway differentially modulated between groups was de novo lipogenesis, the group with more PUFA being the one that showed lower expression of lipogenic genes. These results will help in the identification of genetic variants at loci that affect fatty acid composition traits. The implications of these results range from the improvement of porcine meat quality traits to the application of the pig as an animal model of human metabolic diseases. The supplementary files contains the five arrays reported in the paper.
Project description:Background & Aims: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common complication of obesity with a hallmark feature of hepatic steatosis. Recent data from animal models of MALFD have demonstrated substantial changes in macrophage composition in the fatty liver. In humans, the relationship between liver macrophage heterogeneity and liver steatosis is less clear. Methods: Liver tissue from 21 participants was collected at time of bariatric surgery and analyzed using flow cytometry, immunofluorescence, and H&E microscopy. Single-cell RNA sequencing was also conducted on a subset of samples (n=3). Intrahepatic triglyceride content was assessed via MRI and tissue histology. Mouse models of hepatic steatosis were used to investigate observations made from human liver tissue. Results: We observed variable degrees of liver steatosis with minimal fibrosis in our participants. Single-cell RNA sequencing revealed four macrophage clusters that exist in the human fatty liver encompassing Kupffer cells (KC) and monocyte-derived macrophages (MdM). The genes expressed in these macrophage subsets were similar to those observed in mouse models of MAFLD. Hepatic CD14+ monocytes/macrophage number correlated with the degree of steatosis. Using mouse models of early liver steatosis we demonstrate recruitment of MdMs precedes KC loss and liver damage and that MdMs may serve a role in lipid uptake during MAFLD. Conclusions: The human liver in MAFLD contains macrophage subsets that align well with those that appear in mouse models of fatty liver disease. Recruited myeloid cells correlate well with the degree of liver steatosis in humans and this occurs prior to changes in KC number. MdMs appear to have a role in lipid uptake during early stages of MALFD.
Project description:Fatty infiltration, the ectopic deposition of adipose tissue within skeletal muscle, is mediated via the adipogenic differentiation of fibro-adipogenic progenitors (FAPs). We used single-nuclei and single-cell RNA sequencing to characterize FAP heterogeneity in patients with fatty infiltration. We identified an MME+ FAP subpopulation which, based on ex vivo characterization as well as transplantation experiments, exhibits high adipogenic potential. MME+ FAPs are characterized by low activity of WNT, known to control adipogenic commitment, and are refractory to the inhibitory role of WNT activators. Using preclinical models for muscle damage versus fatty infiltration, we show that many MME+ FAPs undergo apoptosis during muscle regeneration and differentiate into adipocytes under pathological conditions, leading to their depletion. Finally, we utilized the varying fat infiltration levels in human hip muscles to show the depletion of MME+ FAPs in fatty infiltrated human muscle. Altogether, we have identified the dominant adipogenic FAP subpopulation in skeletal muscle.
Project description:Metabolic remodeling is one of the earliest events that occur during the early differentiation of embryonic stem cells (ESCs), but how these metabolic changes are regulated and participate in the cell differentiation is still largely undissected. Here, we define the fatty acid metabolism as a key player in definitive endoderm (DE) differentiation from human ESCs. During DE differentiation, lipogenesis is decreased while fatty acid β oxidation is enhanced. This dynamic is due to the phosphorylation of lipogenic enzyme acetyl-CoA carboxylase (ACC), which is mediated by AMP-activated protein kinase (AMPK) and inhibits the de novo fatty acid synthesis. More importantly, inhibition of fatty acid synthesis by either its inhibitors or AMPK agonist, significantly promotes the human endoderm differentiation, while blockade of the fatty acid oxidation by genetic manipulation or chemical antagonists impairs the differentiation. The de novo fatty acid synthesis inhibition and fatty acid β oxidation maintaining contribute to the accumulation of cellular acetyl-CoA, which is the essential substrate for protein acetylation. Further study reveals that SMAD3 acetylation and the subsequent subcellular localization exhibit significant change upon interfering fatty acid metabolism. Mechanistically, the accumulation of cellular acetyl-CoA guarantees the acetylation of key transcription factor SMAD3, which further causes the nuclear localization and activation of SMAD signaling pathway to promote DE differentiation. Thus, our current study reveals a fatty acid synthesis/oxidation shift during early differentiation and presents an instructive role of fatty acid metabolism in regulating human early endoderm differentiation.