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The neuropeptide alpha-MSH in host defense
A Catania1, M Cutuli, L Garofalo
1Division of Internal Medicine, Ospedale Maggiore di Milano IRCCS, Via F. Sforza 35, 20122 Milano, Italy. Anna.Catania@unimi.it
Abstract:
The presence of the ancient peptide alpha-melanocyte-stimulating hormone (alpha-MSH) in barrier organs such as gut and skin suggests that this potent anti-inflammatory molecule may be a component of the innate host defense. In tests of antimicrobial activities, alpha-MSH and its fragment KPV showed inhibitory influences against the gram-positive bacterium Staphylococcus aureus and the yeast Candida albicans. Anti-tumor necrosis factor and antimicrobial effects of alpha-MSH suggest that the peptide might likewise reduce replication of human immunodeficiency virus (HIV). Treatment with alpha-MSH reduced HIV replication in chronically and acutely infected human monocytes. At the molecular level, alpha-MSH inhibited activation of the transcription factor NF-kappa B known to enhance HIV expression. alpha-MSH that combines antipyretic, anti-inflammatory, and antimicrobial effects could be useful in the treatment of disorders in which infection and inflammation coexist.
Insights
The ancient peptide alpha-melanocyte-stimulating hormone (alpha-MSH) exhibits anti-inflammatory and antimicrobial properties. It also inhibits human immunodeficiency virus (HIV) replication by blocking NF-kappa B activation.
Area of Science:
- Immunology
- Microbiology
- Virology
Background:
- Alpha-melanocyte-stimulating hormone (alpha-MSH) is an ancient peptide found in barrier organs.
- Its anti-inflammatory properties suggest a role in innate host defense.
Purpose of the Study:
- To investigate the antimicrobial and anti-human immunodeficiency virus (HIV) activities of alpha-MSH.
- To elucidate the molecular mechanisms underlying alpha-MSH's effects on HIV replication.
Main Methods:
- Antimicrobial assays against Staphylococcus aureus and Candida albicans.
- In vitro studies on HIV replication in human monocytes.
- Analysis of NF-kappa B activation in response to alpha-MSH treatment.
Main Results:
- Alpha-MSH and its fragment KPV demonstrated inhibitory effects against Staphylococcus aureus and Candida albicans.
- Alpha-MSH treatment reduced HIV replication in both chronically and acutely infected human monocytes.
- Alpha-MSH inhibited the activation of the transcription factor NF-kappa B, which enhances HIV expression.
Conclusions:
- Alpha-MSH possesses significant anti-inflammatory, antimicrobial, and anti-HIV properties.
- The peptide's ability to inhibit NF-kappa B activation is a key mechanism in reducing HIV replication.
- Alpha-MSH could be a valuable therapeutic agent for disorders involving coexisting infection and inflammation.