(P20-034-25) Evaluation of Mitochondrial Function and IL-6 Levels in a Polygenic Mouse Model for Obesity and Type 2 Diabetes, TALLYHO/Jng vs C57BL/6J Mice
Marshall University Huntington, West Virginia, United States
Disclosure(s):
Jung Han Kim, PhD: No relevant financial relationship(s) with ineligible companies to disclose.
Objectives: Impaired mitochondrial respiration capacity is suggested as a key pathogenic mechanism that links obesity and type 2 diabetes (T2D), concomitantly related diseases, associated with an increased inflammation. Increased adipose tissue mass is recognized as a pivotal factor underlying the mitochondrial dysfunction and inflammation. The TALLYHO/Jng (TH) mouse is a newly developed obesity- and T2D-prone polygenic model. The goal of this study was to evaluate adipose tissue mitochondrial respiration and pro-inflammatory IL-6 levels in TH mice vs normal C57BL/6J (B6) mice.
Methods: All mice including TH and B6 were bred in our animal facility. At 4 weeks of age, mice were weaned onto standard rodent chow. At 16-18 weeks of age, male mice were euthanized, and blood was collected. For mitochondrial respiration assay, stromal vascular fraction (SVF) cells were isolated from the epididymal adipose tissue. The oxygen consumption rate (OCR) was measured using the Seahorse Biosciences XF Extracellular Flux Analyzer (Seahorse Bioscience) following the manufacturer’s instructions. Data were normalized by total protein concentration. Plasma IL-6 levels were determined using ELISA kit (R&D Systems). Protein expression levels of IL-6 in the epididymal adipose tissue were measured by Western blot analysis. Statistical data analysis was conducted using GraphPad Prism (version 7.03). Significance was considered at P < 0.05.
Results: Bioenergetic profile involves (1) basic OCR, cells were incubated in normal medium, (2) ATP synthesis turnover, oligomycin was supplemented to the medium to inhibit ATP synthase, (3) maximal mitochondrial respiratory capacity, cells were incubated with FCCP, and (4) non-mitochondrial respiration, rotenone/ antimycin A were introduced to inhibit complex I and III, respectively. SVF cells of TH mice showed significantly lower maximal and spare respirations compared to them of B6. TH mice had significantly higher plasma IL-6 levels than B6. In epididymal adipose tissue, there was a trend of increased IL-6 protein expression in TH mice, compared to B6, however it did not reach statistical significance.
Conclusions: The obesity and T2D in TH mice are associated with decreased mitochondrial function and increased inflammation.
