Retinoic acid (RA) administration and chronic vitamin A supplementation were reported to inhibit adipose tissue leptin expression in rodents, but the impact of this effect on food intake and its relationship with changes of body adiposity was not analyzed. Here, we have studied the effects of RA administration at three different doses on body weight, adipose tissue mass, food intake, adipose tissue leptin expression and circulating leptin levels in NMRI mice; the effects of chronic vitamin A supplementation with a 40-fold excess retinyl palmitate on the same parameters in NMRI and C57BL/6J mice; and the effects of RA and retinoid receptors agonists on leptin expression in brown and white adipocyte cell model systems. The results show that vitamin A down-regulates leptin expression in white and brown adipose tissue and circulating leptin levels independently of changes of adipose tissue mass and, for the first time to our knowledge, that this effect does not correlate with increased food intake. They also demonstrate a direct inhibitory effect of RA on leptin expression in both white and brown adipocyte cell cultures, and constitute first proof of the involvement of both RA receptors (RARs) and rexinoid receptors (RXRs) in this effect. Reduction of leptin levels by specific nutrients is of potential interest from a clinical point of view.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.bbadis.2004.11.014 | DOI Listing |
Ann Nutr Metab
January 2025
Department of Translational Medical Science, University of Naples Federico II, Napoli, Italy.
Background: Knowledge of the complex interplay between gut microbiota and human health is gradually increasing as it has just recently been a field of such great interest.
Summary: Recent studies have reported that communities of microorganisms inhabiting the gut influence the immune system through cellular responses and shape many physiological and pathophysiological aspects of the body, including muscle and bone metabolism (formation and resorption). Specifically, the gut microbiota affects skeletal homeostasis through changes in host metabolism, the immune system, hormone secretion, and the gut-brain axis.
Biotechnol Prog
January 2025
Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, India.
Type 2 diabetes mellitus (T2DM) and obesity are critical global health issues with rising incidence rates. Glucagon-like peptide-1 (GLP-1) analogues have emerged as effective treatments due to their ability to regulate blood glucose levels and gastric emptying through central nervous signals involving hypothalamic receptors, such as leptin. To address the short plasma half-life of native GLP-1, a C-16 fatty acid was conjugated to lysine in the GLP-1 analogue sequence to enhance its longevity.
View Article and Find Full Text PDFJ Clin Invest
January 2025
Lindsley F. Kimball Research Institute, New York Blood Center, New York, United States of America.
The bone marrow (BM) niche is critical in regulating hematopoiesis, and sexual dimorphism and its underlying mechanism in BM niche and its impact on hematopoiesis are not well understood. We show that male mice exhibited a higher abundance of leptin-receptor-expressing mesenchymal stromal cells (LepR-MSCs) compared to female mice. Sex-mismatched co-culture and BM transplantation showed that the male BM niche provided superior support for in vitro colony formation and in vivo hematopoietic engraftment.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Cuisine and Nutrition, School of Tourism and Cuisine, Yangzhou University, Yangzhou, China.
In addition to being linked to an excess of lipid accumulation in the liver, being overweight or obese can also result in disorders of lipid metabolism. There is limited understanding regarding whether different levels of protein intake within an energy-restricted diet affect liver lipid metabolism in overweight and obese rats and whether these effects differ by gender, despite the fact that both high protein intake and calorie restriction can improve intrahepatic lipid. The purpose of this study is to explore the effects and mechanisms of different protein intakes within a calorie-restricted diet on liver lipid metabolism, and to investigate whether these effects exhibit gender differences.
View Article and Find Full Text PDFRedox Biol
January 2025
Department of Anatomy and Convergence Medical Science, College of Medicine, Metabolic Dysfunction Liver Disease Research Center, Institute of Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea. Electronic address:
Although leptin-deficient ob/ob mice have been investigated to determine whether hepatic steatosis promotes susceptibility to hepatotoxic insults, carbon tetrachloride (CCl)-induced hepatic fibrosis in ob/ob mice remains largely unknown. In this study, we evaluate the pathogenic mechanisms of hepatic fibrosis in CCl-treated wild-type (WT) and ob/ob mice and analyze some parameters related to lipogenesis, inflammation, fibrosis, oxidative stress, apoptosis, and autophagy. CCl treatment attenuated liver weight and lipogenesis in ob/ob mice.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!