Project description:miRNA profiles were investigated in skeletal muscle in severely obese individuals with or without diabetes before and after Roux-en-Y gastric bypass surgery.
Project description:Obesity results from a chronic imbalance between energy intake and energy expenditure, with excess calories stored as fat. As such, weight loss has long been considered as a primary goal of treatment for obesity. A surgical treatment of severe obesity such as gastric bypass provides the most dramatic reductions in body weight, and a well-known effect of weight loss is an improvement in insulin sensitivity. However, the molecular mechanism underlying this association remains unclear. Thus, we profiled skeletal muscle of morbidly obese patients before and after gastric bypass surgery. Results from this project will provide global patterns of gene expression with weight loss, which help to understand the pathogenesis of obesity at the molecular level. Experiment Overall Design: To identify responsive genes to weight loss.
Project description:Roux-en-Y gastric bypass (RYGB) is the most effective therapy for morbid obesity, but it has a ~20% failure rate. We used our established RYGB model in diet-induced obese (DIO) Sprague-Dawley rats, which reproduces human bi-phasic body weight (BW) loss pattern, to determine mechanisms contributing to success (RGYB-S) or failed (RYGB-F) RYGB. DIO rats were randomized to RYGB, sham operated Obese, and sham operated obese pair fed-linked to RYGB (PF) groups. BW, caloric intake (CI) and fecal output (FO) were recorded daily for 90 days, food efficiency (FE) was calculated, and morphologic changes were determined. Gut, adipose and thyroid hormones were measured in plasma. Mitochondrial respiratory complexes in skeletal muscle, expression of energy-related hypothalamic and fat peptides, receptors and enzymes were quantified. A 25% failure rate occurred. RYGB-S, RYGB-F and PF rats vs. Obese showed rapid BW decrease, followed by sustained BW loss in RYGB-S. RYGB-F and PF gradually increased BW. Expression profiling of both CNS (hypothalamus) and peripheral tissues (subcutaneous abdominal fat) strongly supported the involvement of a number of metabolic and feeding-related genes in the differential outcomes. Experiment Overall Design: 3 biological replicate RNA samples were prepared from 2 tissues (the subcutaneous abdominal fat or the hypothalamus) from rats in 3 treatment groups (rats losing weight successfully after gastric bypass surgery, rats gaining weight, and rats that were fed the same amount as the treated rats)
Project description:Obesity results from a chronic imbalance between energy intake and energy expenditure, with excess calories stored as fat. As such, weight loss has long been considered as a primary goal of treatment for obesity. A surgical treatment of severe obesity such as gastric bypass provides the most dramatic reductions in body weight, and a well-known effect of weight loss is an improvement in insulin sensitivity. However, the molecular mechanism underlying this association remains unclear. Thus, we profiled skeletal muscle of morbidly obese patients before and after gastric bypass surgery. Results from this project will provide global patterns of gene expression with weight loss, which help to understand the pathogenesis of obesity at the molecular level. Keywords: Time-Series
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:MBD-Seq in Vastus Lateralis from male Subjects before and after GBP surgery Skeletal muscle samples were obtained from subjects immediately before and 6 months after Gastric Bypass surgery
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.