Project description:Genome-wide association identified SLC16A13 as novel type 2 diabetes gene locus. The SLC16A13 gene encodes for SLC16A13/MCT13, member of the solute carrier 16 family of monocarboxylate transporters. This transporter family recently raised interest in metabolic research with the identification of SLC16A11 polymorphisms associated with type 2 diabetes; and human as well as mouse data suggest causal relationship between SLC16A11/MCT11 transporter dysfunction and type 2 diabetes development. In contrast, SLC16A13 biology and physiological function is not characterized at all. Here, we validate SLC16A13 as monocarboxylate transporter expressed at the plasma membrane and report the first Slc16a13 knockout mouse line. Deletion of Slc16a13 ameliorates metabolic disease in the context of diet-induced obesity. The improved metabolic phenotype is characterized by increased mitochondrial respiration in the liver, leading to reduced hepatic lipid accumulation and increased insulin sensitivity of Slc16a13 knockout mice. Mechanistically, we propose reduced intracellular lactate availability in Slc16a13 knockout hepatocytes, affecting hepatic energy metabolism by AMPK activation and increased oxidative phosphorylation, reducing hepatic lipid content and insulin resistance in obese mice. Together, these data suggest SLC16A13/MCT13 as potential novel target to treat fatty liver, insulin resistance and related metabolic disorders.
Project description:In the present study, we explored whether skeletal muscle cystathionine γ-lyase (CTH) contributes to high-fat diet (HFD)-induced metabolic disorders using skeletal muscle Cth knockout (CthΔskm) mice. Metabolomics coupled with transcriptome showed that CthΔskm mice displayed impaired energy metabolism and some signaling pathways linked to insulin resistance (IR) in skeletal muscle although the mice had normal insulin sensitivity. HFD led to reduced CTH expression and impaired energy metabolism in skeletal muscle in Cth-floxed mice (Cthf/f) mice. CTH deficiency and HFD had some common pathways enriched in the aspects of amino acid metabolism, carbon metabolism, and fatty acid metabolism. CthΔskm+HFD mice exhibited increased body weight gain, fasting blood glucose, plasma insulin, and IR, and reduced glucose transporter 4 and CD36 expression in skeletal muscle compared to Cthf/f+HFD mice. Impaired mitochondria and irregular arrangement in myofilament occurred in CthΔskm+HFD mice. Omics analysis showed differential pathways enriched between CthΔskm mice and Cthf/f mice upon HFD. More severity in impaired energy metabolism, reduced AMPK signaling, and increased oxidative stress and ferroptosis occurred in CthΔskm+HFD mice compared to Cthf/f+HFD mice. Our data indicate that skeletal muscle CTH expression dysregulation contributes to metabolism disorders upon HFD.
Project description:Pompe disease is a Lysosomal glycogen storage disorder due to the deficiency of acid alpha glucosidase. The enzyme degrades glycogen to glucose and its deficiency results in progressive enlargement of glycogen-filled lysosomes in multiple tissues with skeletal and cardiac muscle most severely affected clinically. Clinical spectrum ranges from most severe infantile cardiomegally and skeletal muscle myopathy to milder late onset forms with only skeletal muscle pathology. The currently available enzyme replacement therapy has only limited effect in skeletal muscle. Here we use RNA sequencing of therapy-resistant skeletal muscle (white part of gastrocnemius muscle) to identify the differencies between the diseased and healthy muscle. Total RNA was obtained from gastrocnemius muscle (white part) of acid alpha glucosidase knock-out and wild-type mice.
Project description:Analysis of AMPK gamma3-dependent transcriptional responses by analyzing global gene expression in the white portion of the gastrocnemius muscle in AMPK gamma3 knock-out mice and corresponding wild type littermates. Keywords: Genetic modification
Project description:My lab studies the function of the molecular clocks in skeletal muscle. We have an inducible genetic mouse model (C57Bl6 background) in which we knock out the core clock gene, Bmal1, only in adult skeletal muscle after treatment with tamoxifen. We have found that the mice maintain body mass but lose fat mass at 10 weeks after loss of Bmal1. We have done expression profiling on the skeletal muscles and gene expression changes (insulin signaling, CHO metabolism, fat metabolism) suggest significant changes in substrate metabolism. To analyze TCA, CHO metabolites we have collected gastrocnemius muscles from these mice following instructions from Dr. Burant. Mice were anaesthetized with isoflurane, the gastrocnemius muscle dissected and flash frozen with tongs cooled with liquid N2. They have been stored in cryovials in our -80 freezer for 2 months.
Project description:Transcriptomic profile of skeletal muscle in wild-type, GAA knock-out, and AAV treated GAA knock-out mice to understand Pompe disease mechanisms and assess therapeutic efficacy
Project description:Knock out of the Nebulin gene. We compared the Quadriceps of two Nebulin -deficient vs. 2 Wildtype mice. The two KO-WT pairs derived from two litters (F2 generation, background: C57/Bl6 and 129/IB10).