Adipocytokine Protein Expression from Visceral Fat Differs Significantly Based on Diet, Sex, and Age in C3H/HeJ Mice Fed Long-Term, High-Fat Diets, ± Ammonium-Hydroxide-Supplemented Dietary Protein

(1) Background: Overconsumption of processed meats, fats, and carbohydrates drives the obesity epidemic in the USA. Associated with this epidemic are increases in metabolic diseases, such as type 2 diabetes, cardiovascular disease, and cancer. In this study, protein levels of adipocytokines isolated from visceral fat in mice fed high-fat diets with proteins modified through ammonium supplementation were analyzed to determine changes that occur as a result of dietary protein source and its modification based on age or sex. (2) Methods: Male and female C3H/HeJ mice were randomized into six customized diets—Group 1: CCN = Control Chow (CC) + Ammonium Hydroxide Enhancement (AHE); Group 2: CC = Control Chow; Group 3: HFBN = High Fat (HF) AHE Dietary Beef; Group 4: HFB = HF Beef; Group 5: HFCN = HF AHE Dietary Casein; Group 6: HFC = HF Dietary Casein. Mice were censored at six-month intervals, and visceral fat was collected for analysis. This study highlights sex- and age-related changes in cellular adipocytokine protein expression from 12 to 18 months. (3) Results: When compared to dietary casein, dietary-beef-fed mice showed increased expression of adiponectin, leptin, and MCP-1. In dietary casein protein diets, high fat content was correlated with the expression of pro-inflammatory adipocytokines leptin, MCP-1, resistin, VEGF-A, and TIMP-1. Sex-related differences were observed in adiponectin, leptin, and MCP-1 expression levels. AHE of dietary protein decreased the expression of adiponectin, leptin, MCP-1, and TIMP-1. Age-related changes in expression were observed in leptin, MCP-1, and VEGF-A. (4) Conclusions: Our results indicate that the source of dietary protein plays a critical role in determining adipocytokine expression in WAT. Furthermore, this study shows that in addition to dietary protein type (beef or casein), AHE and fat content also impact the relative expression of both pro-inflammatory and anti-inflammatory adipocytokines based on sex over time, with leptin and MCP-1 identified as the most frequently affected.