Dexamethasone and Acetate Modulate Cytoplasmic Leptin in Bovine Preadipocytes

Abstract

Hormonal and nutrient signals regulate leptin synthesis and secretion. In rodents, leptin is stored in cytosolic pools of adipocytes. However, not much information is available regarding the regulation of intracellular leptin in ruminants. Recently, we demonstrated that leptin mRNA was expressed in bovine intramuscular preadipocyte cells (BIP cells) and that a cytoplasmic leptin pool may be present in preadipocytes. In the present study, we investigated the expression of cytoplasmic leptin protein in BIP cells during differentiation as well as the effects of various factors added to the differentiation medium on its expression in BIP cells. Leptin mRNA expression was observed only at 6 and 8 days after adipogenic induction, whereas the cytoplasmic leptin concentration was the highest on day 0 and decreased gradually thereafter. Cytoplasmic leptin was detected at 6 and 8 days after adipogenic induction, but not at 4 days after adipogenic induction. The cytoplasmic leptin concentration was reduced in BIP cells at 4 days after treatment with dexamethasone, whereas cytoplasmic leptin was not observed at 8 days after treatment. In contrast, acetate significantly enhanced the cytoplasmic leptin concentration in BIP cells at 8 days after treatment, although acetate alone did not induce adipocyte differentiation in BIP cells. These results suggest that dexamethasone and acetate modulate the cytoplasmic leptin concentration in bovine preadipocytes.

The association of short-chain fatty acids and leptin metabolism: a systematic review

“…45,[54][55][56][57]59 One study found that butyrate can stimulate leptin expression in bovine pituitary cells but inhibits its expression in rat pituitary cells. 58 The remaining in vitro study found no statistically significant effect of acetate or propionate on leptin production, even though SCFA did activate FFAR2. 60 The mechanisms by which SCFA increase leptin expression were studied in vitro in five studies.…”

- Invited Review - Physiological Roles of Adipokines, Hepatokines, and Myokines in Ruminants

“…The capacity of lipid synthesis in adipocytes of ruminants is high compared to that in other species. Excess energy is stored as triglycerol, which is broken down into glycerol and fatty acids ( Yonekura et al, 2014 ; Choi et al, 2015 ). Fatty acids are consumed as an energy source in the peripheral tissues.…”