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Updated: Aug 11, 2026
Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
A serotonin-like immunoreactivity is present in human cutaneous melanocytes
O Johansson1, P Y Liu, L Bondesson
1Department of Neuroscience, Karolinska Institute, Stockholm, Sweden.
Insights
Human skin melanocytes show serotonin-like immunoreactivity, suggesting they produce serotonin or a similar molecule. This finding opens new avenues for understanding skin physiology and potential therapeutic targets.
Area of Science:
- Dermatology
- Neuroscience
- Cell Biology
Background:
- Serotonin, a key neurotransmitter, plays diverse roles in the body.
- Its presence and function within human skin, particularly in melanocytes, remain largely unexplored.
Purpose of the Study:
- To investigate the presence and localization of serotonin or serotonin-like molecules in human skin.
- To determine if epidermal melanocytes are a source of serotonin in the skin.
Main Methods:
- Immunohistochemistry was employed to detect serotonin-like immunoreactivity in human skin.
- Blocking experiments and co-localization with melanocyte markers (NKI-beteb) were performed.
- In vitro studies utilized cultured human melanocytes to confirm findings.
Main Results:
- Epidermal melanocytes exhibited serotonin-like immunoreactivity in both cytoplasm and cellular membranes.
- This immunoreactivity co-localized with the melanocyte marker NKI-beteb.
- In vitro studies confirmed serotonin-like immunoreactivity in approximately 90% of cultured melanocytes, including nuclear localization.
Conclusions:
- Human skin melanocytes express serotonin or a serotonin-like molecule.
- Melanocytes are likely the endogenous source of serotonin within the skin.
- This discovery may have implications for skin biology and related disorders.
Abstract:
Immunohistochemistry was applied in the investigation of the possible existence of serotonin in human skin. It was found that epidermal melanocytes express a serotonin-like immunoreactivity. The immunoreactivity was associated with both the cytoplasm and the cellular membrane, though the latter was only found in certain cells. The serotonin anti-serum labeled the same cells as NKI-beteb, which is known as a reliable marker of melanocytes. Blocking experiments showed that both serotonin and NKI-beteb have different epitopes in the melanocytes. In in vitro studies, serotonin-like immunoreactivity appeared in approximately 90% of cultured human melanocytes, and was found both in the cytoplasm and also in the nuclei. Thus, we believe the melanocytes to be the origin of serotonin (or a serotonin-like molecule) in the skin.
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