Saturated fatty acids stimulate and insulin suppresses CIDE-A expression in bovine mammary epithelial cells

Abstract

Cell death-inducing DNA fragmentation factor-alpha-like effector A (CIDE-A) was first identified by its sequence homology with the N-terminal domain of DNA fragmentation factor (DFF). CIDE-A negatively regulates the activity of uncoupling protein 1 (UCP1) in brown adipose tissue. CIDE-A and UCP1 mRNA were detected by RT-PCR in cloned bovine mammary epithelial cells (bMEC) and lactating bovine mammary glands. Physiological concentrations of saturated fatty acids (stearate and palmitate), but not unsaturated fatty acids (oleate and linoleate) induced up-regulation of CIDE-A mRNA in bMEC. Treatment with insulin (5-10 ng/ml) induced down-regulation of CIDE-A and UCP1. The expression levels of CIDE-A and UCP1 mRNA in bovine mammary glands at various stages of the lactation cycle were determined by quantitative RT-PCR analysis. CIDE-A mRNA expression at peak lactation (2 months after parturition) was significantly higher than at dry off and non-pregnancy but not late lactation. These results suggest that CIDE-A and UCP1 are regulated by insulin and/or fatty acids in mammary epithelial cells and lactating mammary glands, and thereby play an important role in lipid and energy metabolism.

Differential roles of CIDEA and CIDEC in insulin-induced anti-apoptosis and lipid droplet formation in human adipocytes

“…These results suggest that the observed effects of insulin on CIDE mRNA expression may not result from differentiation or PPAR ␥ -directed transcription. It has recently been reported that insulin suppresses CIDEA expression in bovine mammary epithelial cells ( 40 ) and increases CIDEC expression in mouse 3T3-L1 adipocytes ( 36 ). These reports support our fi ndings in human adipocytes.…”

Comparative Proteomics of Milk Fat Globule Membrane Proteins from Transgenic Cloned Cattle

“…Fatty acid-binding protein (FABP) regulates the channeling of fatty acids toward copious milk fat synthesis in bovine mammary gland [43]. The expression level of CIDE-A protein was regulated by insulin and/or fatty acids in mammary epithelial cells, and thereby played an important role in lipid and energy metabolism [44]. Acyl-coa synthetase long-chain family member 1 (ACSL1) which involves in fatty acid analysis [43] was differentially expressed in lactation,.…”

Cell death‐inducing DFF45‐like effector b (Cideb) is present in pancreatic beta‐cells and involved in palmitate induced beta‐cell apoptosis

“…As for the roles of CIDEs in lipid metabolism, CIDE family proteins have been categorized as lipid droplet‐associated proteins . In order to facilitate research on lipid droplet associated‐proteins, FFAs are often used to increase intracellular lipid droplets . What is more, prolonged incubation with FFAs has a devastating impact on beta cell viability .…”

“…The first known function of CIDEs was promotion of apoptosis upon ectopic expression in mammalian cells . However, recent studies in endogenous settings demonstrated key roles for CIDEs in energy metabolism . Our previous studies proved that Cideb could act as a metabolic sensor to respond to varying metabolic conditions and regulate multiple lipid metabolism pathways including fatty acid synthesis, storage and lipid secretion in livers .…”

“…Recent studies have also addressed the role of CIDE family member in lipid metabolism and lipid droplet formation in vitro and in vivo . In our previous report, we have proved that Cideb has emerged as an important regulator in the development of obesity and diabetes by controlling fatty acid synthesis and very low‐density lipoprotein secretion, as well as cholesterol biosynthesis, uptake and storage in hepatocytes .…”