title: 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.
authors: Institute of Rural Studies, University of Wales, Aberystwyth, Ceredigion SY23 3AL, UK .
authors: Shinichi
authors: S
authors: Yonekura
authors: Institute of Rural Studies, University of Wales, Aberystwyth, Ceredigion SY23 3AL, UK .
authors: Shohei
authors: S
authors: Hirota
authors: Institute of Rural Studies, University of Wales, Aberystwyth, Ceredigion SY23 3AL, UK .
authors: Yukako
authors: Y
authors: Tokutake
authors: Institute of Rural Studies, University of Wales, Aberystwyth, Ceredigion SY23 3AL, UK .
authors: Michael T
authors: MT
authors: Rose
authors: Department of Animal Physiology, Graduate School of Agriculture, Tohoku University, Amamiyamachi, Sendai 981-8555, Japan .
authors: Kazuo
authors: K
authors: Katoh
authors: Department of Cellular Biology, Graduate School of Agriculture, Tohoku University, Amamiyamachi, Sendai 981-8555, Japan .
authors: Hisashi
authors: H
authors: Aso
keywords: Acetate; Bovine; Cytoplasm; Dexamethasone; Leptin; Preadipocyte