Project description:Analysis of glucose and Lipid metabolism in male and female offspring after protein restriction of the mother Male offspring showed features of metabolic syndrome after receiving a high fat diet, regardless of the diet of the dam. Glucose and lipid metabolism in male offspring was unaltered. Insulin sensitivity and hepatic fatty acid storage in female offspring of low-protein-fed dams changed in such a way that it resembled the male pattern of insulin sensitivity and hepatic fatty acid storage. Microarray analysis on hepatic gene expression patterns confirmed these findings. We therefore conclude that in mice, maternal protein restriction does not change the response of glucose and fatty acid metabolism to a high fat diet in male offspring, but does program metabolism in female offspring in such a way that it resembles male metabolism. Our findings might have implications for potential future gender-specific treatment of the features of metabolic diseases. Total RNA obtained from liver (16 samples per gender) were compared in the different groups. In total, 4 groups per gender, each group consisting of 4 biological replicates.
Project description:Analysis of glucose and Lipid metabolism in male and female offspring after protein restriction of the mother Male offspring showed features of metabolic syndrome after receiving a high fat diet, regardless of the diet of the dam. Glucose and lipid metabolism in male offspring was unaltered. Insulin sensitivity and hepatic fatty acid storage in female offspring of low-protein-fed dams changed in such a way that it resembled the male pattern of insulin sensitivity and hepatic fatty acid storage. Microarray analysis on hepatic gene expression patterns confirmed these findings. We therefore conclude that in mice, maternal protein restriction does not change the response of glucose and fatty acid metabolism to a high fat diet in male offspring, but does program metabolism in female offspring in such a way that it resembles male metabolism. Our findings might have implications for potential future gender-specific treatment of the features of metabolic diseases.
Project description:The effects of adiponectin on hepatic glucose and lipid metabolism at transcriptional level are largely unknown. We profiled hepatic gene expression in adiponectin knockout (KO) and wild-type (WT) mice by RNA-Seq. Comparing to WT mice, adiponectin KO mice exhibited decreased mRNA expression of rate-limiting enzymes in several important glucose and lipid metabolic pathways including glycolysis, TCA cycle, fatty-acid activation and synthesis, triglyceride synthesis and cholesterol synthesis. In addition, binding of the transcription factor Hnf4a to DNAs encoding several key metabolic enzymes was reduced in KO mice, suggesting that adiponectin might regulate hepatic gene expression via Hnf4a. Phenotypically, adiponectin KO mice possessed smaller epididymal fat pads and showed reduced body weights comparing to WT mice. When fed a high fat diet, adiponectin KO mice showed significantly reduced lipid accumulation in the livers. These lipogenic defects are consistent with the downregulation of lipogenic genes in the KO mice.
Project description:Objectives: Studies have shown a correlation between obesity and mitochondrial calcium homeostasis, yet it is unclear whether and how Mcu regulates adipocyte lipid deposition. This study aims to provide new potential target for the treatment of obesity and related metabolic diseases, and to explore the function of Mcu in adipose tissue. Methods: We firstly investigated the role of mitoxantrone, an Mcu inhibitor, in the regulation of glucose and lipid metabolism in mouse adipocytes (3T3-L1 cells). Secondly, C57BL/6J mice were used as a research model to investigate the effects of Mcu inhibitors on fat accumulation and glucose metabolism in mice on a high-fat diet (HFD), and by using CRISPR/Cas9 technology, adipose tissue-specific Mcu knockdown mice (Mcu fl/+ AKO) and Mcu knockout of mice (Mcu fl/fl AKO) were obtained, to further investigate the direct effects of Mcu on fat deposition, glucose tolerance and insulin sensitivity in mice on a high-fat diet. Results: we found the Mcu inhibitor reduced adipocytes lipid accumulation and adipose tissues mass in mice fed an HFD. Both Mcu fl/+ AKO mice and Mcu fl/fl AKO mice were resistant to HFD-induced obesity, compared to control mice. Mice with Mcu fl/fl AKO showed improved glucose tolerance and insulin sensitivity as well as reduced hepatic lipid accumulation. Mechanistically, inhibition of Mcu promoted mitochondrial biogenesis and adipocyte browning, increase energy expenditure and alleviates diet-induced obesity. Conclusion: Our study demonstrates a link between adipocyte lipid accumulation and mCa2+ levels, suggesting that adipose-specific Mcu deficiency alleviates HFD-induced obesity and ameliorates metabolic disorders such as insulin resistance and hepatic steatosis. These effects may be achieved by increasing mitochondrial biosynthesis, promoting white fat browning and enhancing energy metabolism.
Project description:Purpose: While various functions of peripheral serotonin are known, the direct role of serotonin in regulating hepatic lipid metabolism in vivo is not well understood. We studied whether serotonin directly acts on liver to regulate lipid metabolism. Methods: Methods: 12 weeks aged liver-specific Htr2a KO (Albumin-Cre+/-; Htr2aflox/flox, herein named Htr2a LKO) mice and wildtype (WT) littermates were fed a high-fat diet (HFD, 60% fat calories) for 8 weeks. Results: Hepatic lipid droplet accumulation, NAFLD activity score, and hepatic triglyceride levels were dramatically reduced in HFD-fed Htr2a LKO mice compared to WT littermates. Conclusions: Gut-derived serotonin is a direct regulator of hepatic lipid metabolism via a gut TPH1-liver HTR2A endocrine axis. And shows promise as a novel drug target to ameliorate NAFLD with minimal systemic metabolic effects.
Project description:Long non-coding RNAs (lncRNAs) display higher tissue-specificity than mRNAs. In particular, many lncRNAs are specifically expressed in early embryos, but the physiological functions of most of them remain largely unknown. Here, we show that deficiency of Lncenc1, a lncRNA specifically expressed in early embryos, results in an altered glucose and lipid balance in adult mice. Newly weaned lncenc1-deficient mice have been shown to display higher fasting blood glucose levels and to prefer to use lipids as a fuel source. When mice were fed a normal chow diet (NCD), in which glucose was the main energy source, glucose intolerance and insulin resistance were observed in adult lncenc1-deficient mice. Under high-fat diet (HFD) conditions, however, lncenc1-deficient mice became healthier and could resist food-induced obesity and metabolic disturbances, including liver steatosis and hypercholesterolmia. Furthermore, PPARγ-regulated lipogenesis in liver was reduced in lncenc1-deficient mice fed an HFD, as shown by transcriptome analyses. Interestingly, lncenc1-deficient mouse embryonic fibroblasts (MEFs) showed impaired glycolysis and lipogenesis, suggesting that the metabolic defects may already exist in embryos. Our study provides the first piece of evidence showing the essential roles of embryo-specific lncRNAs in adult metabolism, verifying the “fetal origin” of adult metabolic disorders.
Project description:Although the global prevalence of obesity and type 2 diabetes is rising, the molecular mechanisms of dysregulated glucose and lipid metabolism are still incompletely understood. Epigenetic mechanisms were shown to have an impact in disease manifestation, but the underlying hepatic miRNA expression signature is not completely elucidated. We used microarrays to perform a comprehensive screen of the complete microRNA transcriptome in liver samples of diet induced obese (DIO) mice in order to identify expressed microRNAs that might target genes of hepatic lipid and glucose metabolism.
Project description:Perilipin 2 (Plin2) binds to the surface of hepatic lipid droplets (LDs) with expression levels that correlate with triacylglyceride (TAG) content. We investigated if Plin2 is important for hepatic LD storage in fasted or high-fat diet-induced obese Plin2+/+ and Plin2-/- mice. Plin2-/- mice had comparable body weights, metabolic phenotype, glucose tolerance, and circulating TAG and total cholesterol levels compared to Plin2+/+ mice, regardless of the dietary regime. Both fasted and high-fat fed Plin2-/- mice stored reduced levels of hepatic TAG compared to Plin2+/+ mice. Fasted Plin2-/- mice stored fewer, but larger hepatic lipid droplets compared to Plin2+/+ mice. Detailed hepatic lipid analysis showed substantial reductions in accumulated TAG species in fasted Plin2-/- mice compared to Plin2+/+ mice, whereas cholesteryl esters and phosphatidylcholines were increased. RNA sequencing revealed minor differences in hepatic gene expression between fed Plin2+/+ and Plin2-/- mice, in contrast to marked differences in gene expression between fasted Plin2+/+ and Plin2-/- mice. Our findings demonstrate that Plin2 is required to regulate hepatic lipid droplet size and storage of neutral lipid species in the fasted state, while its role in obesity-induced steatosis is less clear.