Journal Article

Photoperiodic changes in adiposity increase sensitivity of female Siberian hamsters to systemic VGF derived peptide TLQP-21

Cocco, Cristina, Lisci, Carlo, Stevenson, Tyler J., Daniel, Zoe C. T. R., Monnier, Chloe, Ferri, Gian-Luca, Jethwa, Preeti H., Marshall, Hayley J., Fowler, Maxine, Ebling, Francis J. P., Lewis, Jo E.

2019

Overview

TLQP-21, a peptide encoded by the highly conserved vgf gene, is expressed in neuroendocrine cells and has been the most prominent VGF-derived peptide studied in relation to control of energy balance. The recent discovery that TLQP-21 is the natural agonist for the complement 3a receptor 1 (C3aR1) has revived interest in this peptide as a potential drug target for obesity. We have investigated its function in Siberian hamsters (Phodopus sungorus), a rodent that displays natural seasonal changes in body weight and adiposity as an adaptation to survive winter. We have previously shown that intracerebroventricular administration of TLQP-21 reduced food intake and body weight in hamsters in their long-day fat state. The aim of our current study was to determine the systemic actions of TLQP-21 on food intake, energy expenditure and body weight, and to establish whether adiposity affected these responses. Peripheral infusion of TLQP-21 (1mg/kg/day for 7 days) in lean hamsters exposed to short photoperiods (SP) reduced cumulative food intake in the home cage (p<0.05), and intake when measured in metabolic cages (P<0.01). Energy expenditure was significantly increased (p<0.001) by TLQP-21 infusion, this was associated with a significant increase in uncoupling protein 1 mRNA in brown adipose tissue (BAT) (p<0.05), and body weight was significantly reduced (p<0.05). These effects of systemic TLQP-21 treatment were not observed in hamsters exposed to long photoperiod (LP) with a fat phenotype. C3aR1 mRNA and protein were abundantly expressed in the hypothalamus, brown and white adipose tissue in hamsters, but changes in expression cannot explain the differential response to TLQP-21 in lean and fat hamsters.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adipose tissue / Adipose tissue (brown) / Adiposity - drug effects / Animals / Annual variations / Appetite / Biology and Life Sciences / Biomarkers / Body weight / Brain - metabolism / Carbon Dioxide - metabolism / Cricetinae / EDTA / Energy balance / Energy expenditure / Energy Metabolism / Female / Food / Food intake / Gene Expression / Genes / Genomes / Hamsters / Hormones / Hypothalamus / Intracerebroventricular administration / Laboratory animals / Life sciences / Medical research / Medical schools / Medicine and Health Sciences / Messenger RNA / Metabolism / mRNA / Neuropeptides / Neuropeptides - pharmacology / Obesity / Oxygen - metabolism / Peptide Fragments - pharmacology / Peptides / Phenotypes / Photoperiod / Photoperiods / Proteins / Receptors, Complement - metabolism / Research and Analysis Methods / RNA / Rodents / Seasonal variations / Thyroid gland / Uncoupling protein 1 / Weight reduction