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

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Mountjoy, Kathleen G 
Caron, Alexandre 
Hubbard, Kristina 
Shome, Avik 
Grey, Angus C 

Abstract

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.

Description

Keywords

Desacetyl-α-MSH, Obese mouse model, Obesity, POMC, α-MSH, Animals, Energy Metabolism, Female, Male, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Mutation, Protein Binding, Proteolysis, Receptor, Melanocortin, Type 2, Receptor, Melanocortin, Type 4, Weight Gain, alpha-MSH

Journal Title

Mol Metab

Conference Name

Journal ISSN

2212-8778
2212-8778

Volume Title

9

Publisher

Elsevier BV
Sponsorship
MRC (G108/617)
Medical Research Council (G108/617)
Medical Research Council (MC_UU_12012/1)
Medical Research Council (MC_PC_12012)