Abstract
Neurohormones diffuse in sweat and epidermis leading skin bacterial microflora to be largely exposed to these host factors. Bacteria can sense a multitude of neurohormones, but their role in skin homeostasis was only investigated recently. The first study focused on substance P (SP), a neuropeptide produced in abundance by skin nerve terminals. SP is without effect on the growth of Gram-positive (Bacillus cereus, Staphylococcus aureus, and Staphylococcus epidermidis) and Gram-negative (Pseudomonas fluorescens) bacteria. However, SP is stimulating the virulence of Bacillus and Staphylococci. The action of SP is highly specific with a threshold below the nanomolar level. Mechanisms involved in the response to SP are different between bacteria although they are all leading to increased adhesion and/or virulence. The moonlighting protein EfTu was identified as the SP-binding site in B. cereus and Staphylococci. In skin nerve terminals, SP is co-secreted with the calcitonin gene-related peptide (CGRP), which was shown to modulate the virulence of S. epidermidis. This effect is antagonized by SP. Identification of the CGRP sensor, DnaK, allowed understanding this phenomenon as EfTu and DnaK are apparently exported from the bacterium through a common system before acting as SP and CGRP sensors. Many other neuropeptides are expressed in skin, and their potential effects on skin bacteria remain to be investigated. Integration of these host signals by the cutaneous microbiota now appears as a key parameter in skin homeostasis.
Highlights
Skin is a complex ecosystem hosting the second most numerous microbial population of the human body [1]
It was not surprising that EfTu was acting as a surface receptor on the bacterium because this molecule is present in large excess in bacteria [28], and it is recognized as a “moonlighting protein” [29]
Because of their long evolution and history, bacteria have reached a high level of protein fitting [30]; expression of moonlighting proteins should be an alternative strategy to counterbalance the absence of alternative splicing in these organisms
Summary
Gene-Related Peptide: Key Regulators of Cutaneous Microbiota Homeostasis. Bacteria can sense a multitude of neurohormones, but their role in skin homeostasis was only investigated recently. SP is co-secreted with the calcitonin gene-related peptide (CGRP), which was shown to modulate the virulence of S. epidermidis. Many other neuropeptides are expressed in skin, and their potential effects on skin bacteria remain to be investigated. Integration of these host signals by the cutaneous microbiota appears as a key parameter in skin homeostasis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
