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Updated: Sep 3, 2026
Cell Population Analyses During Skin Carcinogenesis
Published on: August 21, 2013
Detection of cryptdin in mouse skin
Y Shirafuji1, T Oono, H Kanzaki
1Department of Dermatology, Okayama University Medical School, Shikata-cho 2-5-1, Okayama 700-8558, Japan.
Abstract:
Defensins are widely distributed and broad-spectrum antimicrobial peptides with activities against bacteria, fungi, and enveloped viruses. Defensins have been isolated from granules of neutrophils from humans, rabbits, rats, and guinea pigs. They have also been found in lung macrophages as well as in Paneth cells of the human, rabbit, and mouse small intestine. The human beta-defensin-2 was recently isolated from human skin. In this study, we detected the expression of mRNA for the defensin cryptdin in BALB/c mouse skin by means of reverse transcriptase PCR amplification. Expression was also detected in dispase-separated epidermis and cultured keratinocytes, but expression was not detected in fibroblasts. The expression of cryptdin mRNA was found to begin on embryonic day 17.5. As determined with specific primers, the cDNA sequence cloned from the skin was found to be identical to that previously reported for cryptdin-5. cDNA derived from cultured keratinocytes demonstrated the sequences of the cryptdin-6 and cryptdin-1 isoforms. In situ hybridization analysis showed that the mRNA of cryptdin was expressed in the suprabasal keratinocytes of the skin in embryonic and neonatal days and then shifted to the hair bulbs in the skin of adult mice.
Insights
Mouse skin expresses antimicrobial defensin cryptdin, particularly in keratinocytes and hair follicles during development and adulthood. This finding highlights defensins
Area of Science:
- Immunology
- Dermatology
- Molecular Biology
Background:
- Defensins are broad-spectrum antimicrobial peptides found in various immune cells and tissues.
- Previous studies identified defensins in neutrophils, macrophages, Paneth cells, and human skin.
Purpose of the Study:
- To investigate the expression and localization of defensin cryptdin mRNA in BALB/c mouse skin.
- To determine the developmental and cellular expression patterns of cryptdin in mouse skin.
Main Methods:
- Reverse transcriptase PCR amplification to detect cryptdin mRNA.
- Dispase separation of epidermis and cell culture of keratinocytes.
- In situ hybridization to localize mRNA expression within the skin.
Main Results:
- Cryptdin mRNA expression was detected in mouse skin, epidermis, and cultured keratinocytes, but not in fibroblasts.
- Expression begins by embryonic day 17.5.
- Specific isoforms (cryptdin-5, -6, and -1) were identified.
- In situ hybridization revealed expression in suprabasal keratinocytes during embryonic/neonatal stages, shifting to hair bulbs in adults.
Conclusions:
- Mouse skin is a site of cryptdin defensin expression.
- Cryptdin expression in skin is developmentally regulated, with distinct cellular localization in embryonic, neonatal, and adult stages.
- These findings suggest a role for defensins in skin immunity and barrier function.
