Project description:Age-related and/or high caloric intake driven changes in visceral adipose tissue contribute to the development of diabetes and cardiovascular disease. The lack of reliable, high-throughput methods to analyze the adipose tissue protein composition has limited our understanding of the protein networks responsible for metabolic regulation of various adipose depots. We have developed a proteomic approach using multiple-dimension liquid chromatography tandem mass spectrometry and multiplexed TMT labeling to analyze protein composition of epididymal adipose tissues isolated from mice fed either low or high fat diet for a short (8 weeks) or a long (18 weeks) term, and from mice that aged (26 weeks old) on low vs. high fat diets. Advancing age and high-fat diet feeding led to graded deterioration, with long-term high fat diet exposure being the worst of all measures of peripheral metabolic health such as body weight, adiposity, plasma fasting glucose, insulin, triglycerides, total cholesterol levels, and glucose and insulin tolerance tests. Epididymal adipose depot proteomic analysis identified >3300 proteins per sample. In response to short-term high fat diet, 43 proteins representing lipid metabolism (e.g., AACS, ACOX1, ACLY) and red-ox pathways (e.g., CPD2, CYP2E, SOD3) were significantly altered (FDR < 10%). Long-term high fat diet significantly altered 55 proteins associated with immune response (e.g., IGTB2, IFIT3, LGALS1) and rennin angiotensin system (e.g. ENPEP, CMA1, CPA3, ANPEP). Age-related changes on low fat diet significantly altered only 18 proteins representing mainly urea cycle (e.g., OTC, ARG1, CPS1), and amino acid biosynthesis (e.g., GMT, AKR1C6). Surprisingly, high fat diet driven age-related changes culminated with alterations in 155 proteins involving primarily the urea cycle (e.g., ARG1, CPS1), immune response/complement activation (e.g., C3, C4b, C8, C9, CFB, CFH, FGA), extracellular remodeling (e.g., EFEMP1, FBN1, FBN2, LTBP4, FERMT2, ECM1, EMILIN2, ITIH3) and apoptosis (e.g., YAP1, HIP1, NDRG1, PRKCD, MUL1) pathways. Our unbiased mass spectrometry method, tailored to adipose tissue, identified both age-related and high fat diet specific proteomic signatures. In addition to well-described immune and extracellular remodeling response to high fat feeding, we have uncovered the pronounced involvement of arginine metabolism in response to advancing age, and branched chain amino acid metabolism in early response to high fat feeding. We were able to uncouple age-related metabolic responses from those associated with caloric intake, a task otherwise difficult to achieve.
2018-07-03 | MSV000082569 | MassIVE
