Desacetyl-α-melanocyte stimulating hormone and α-melanocyte stimulating hormone are required to regulate energy balance

• Main Authors: Kathleen G. Mountjoy (Author), Alexandre Caron (Author), Kristina Hubbard (Author), Avik Shome (Author), Angus C. Grey (Author), Bo Sun (Author), Sarah Bould (Author), Martin Middleditch (Author), Beau Pontré (Author), Ailsa McGregor (Author), Paul W.R. Harris (Author), Renata Kowalczyk (Author), Margaret A. Brimble (Author), Rikus Botha (Author), Karen M.L. Tan (Author), Sarah J. Piper (Author), Christina Buchanan (Author), Syann Lee (Author), Anthony P. Coll (Author), Joel K. Elmquist (Author)
• Format: Book
• Published: Elsevier, 2018-03-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Objective: Regulation of energy balance depends on pro-opiomelanocortin (POMC)-derived peptides and melanocortin-4 receptor (MC4R). Alpha-melanocyte stimulating hormone (α-MSH) is the predicted natural POMC-derived peptide that regulates energy balance. Desacetyl-α-MSH, the precursor for α-MSH, is present in brain and blood. Desacetyl-α-MSH is considered to be unimportant for regulating energy balance despite being more potent (compared with α-MSH) at activating the appetite-regulating MC4R in vitro. Thus, the physiological role for desacetyl-α-MSH is still unclear. Methods: We created a novel mouse model to determine whether desacetyl-α-MSH plays a role in regulating energy balance. We engineered a knock in targeted QKQR mutation in the POMC protein cleavage site that blocks the production of both desacetyl-α-MSH and α-MSH from adrenocorticotropin (ACTH1-39). Results: The mutant ACTH1-39 (ACTHQKQR) functions similar to native ACTH1-39 (ACTHKKRR) at the melanocortin 2 receptor (MC2R) in vivo and MC4R in vitro. Male and female homozygous mutant ACTH1-39 (Pomctm1/tm1) mice develop the characteristic melanocortin obesity phenotype. Replacement of either desacetyl-α-MSH or α-MSH over 14 days into Pomctm1/tm1 mouse brain significantly reverses excess body weight and fat mass gained compared to wild type (WT) (Pomcwt/wt) mice. Here, we identify both desacetyl-α-MSH and α-MSH peptides as regulators of energy balance and highlight a previously unappreciated physiological role for desacetyl-α-MSH. Conclusions: Based on these data we propose that there is potential to exploit the naturally occurring POMC-derived peptides to treat obesity but this relies on first understanding the specific function(s) for desacetyl-α-MSH and α-MSH. Keywords: POMC, Obesity, Desacetyl-α-MSH, α-MSH, Obese mouse model

Item Description

2212-8778
10.1016/j.molmet.2017.11.008