Intra-Abdominal Fat Adipocyte Hypertrophy through a Progressive Alteration of Lipolysis and Lipogenesis in Metabolic Syndrome Rats

Abstract

This study evaluates the progressive participation of enzymes involved in lipolysis and lipogenesis, leading to adipocyte hypertrophy in a metabolic syndrome (MS) rat model caused by chronic consumption of 30% sucrose in drinking water. A total of 70 male Wistar rats were divided into two groups: C and MS. Each of these groups were then subdivided into five groups which were sacrificed as paired groups every month from the beginning of the treatment until 5 months. The intra-abdominal fat was dissected, and the adipocytes were extracted. Lipoprotein lipase (LPL), hormone-sensitive lipase (HSL), protein kinases A (PKA), and perilipin A expressions were determined. The LPL and HSL activities were evaluated by spectrophotometry. Histological staining was performed in adipose tissue. Significant increases were observed in blood pressure, HOMA-IR, leptin, triglycerides, insulin, intra-abdominal fat, and number of fat cells per field (p = 0.001) and in advanced glycosylation products, adipocyte area, LPL, HSL activities and/or expression (p ≤ 0.01) in the MS groups progressively from the third month onward. Lipogenesis and lipolysis were increased by LPL activity and HSL activity and/or expression. This was associated with hyperinsulinemia and release of non-esterified fatty acids causing a positive feedback loop that contributes to the development of adipocyte hypertrophy.

MiR-25-3p regulates the differentiation of intramuscular preadipocytes in goat via targeting <i>KLF4</i>

“…According to the location of fat deposition, it can be divided into four categories: subcutaneous fat, intermuscular fat, intramuscular fat, and visceral fat. Among them, intramuscular fat deposition is of great significance to meat flavor, nutrition, and taste (Cui et al, 2016;Poleti et al, 2018a;Wood et al, 2008). In addition, intramuscular fat cells can gradually accumulate through the proliferation and differentiation to form the marble pattern in meat (Poleti et al, 2018b;Zhao et al, 2019).…”

Oxidative Stress, Plant Natural Antioxidants, and Obesity

“…Lipogenesis is the reaction by which fatty acids that form lipoproteins are esterified with glycerol to constitute triglycerides. It is catalyzed by the enzyme lipoprotein lipase (LPL) [ 46 , 47 , 48 ]. The products of this reaction are then stored in lipid droplets.…”

“…The products of this reaction are then stored in lipid droplets. Lipolysis, which is mediated by the hormone sensitive lipase (HSL), is the breakdown of stored TG [ 46 , 47 , 48 ]. The signaling cascade of norepinephrine (NE) and other hormones that include cyclic adenosine monophosphate (which activates protein kinase A (PKA), decreases the expression and/or activity of HSL [ 49 , 50 ]).…”

The influence of dietary interventions on paraclinical parameters in patients with metabolic syndrome

“…The HOMA index, correlated with visceral fat, shows a decrease in the difference of the average visceral fat, both in DTG and DTSG, vs. CG, but the decrease is statistically insignificant, according to the p value obtained (p=0.834). Published studies show a link between the two parameters with hyperinsulinemia in rats 23 , and with hypercholesterolemia in Japanese-American adults 24 .…”