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Updated: May 1, 2026
Isolation and Culture of Primary Mouse Keratinocytes from Neonatal and Adult Mouse Skin
Published on: July 14, 2017
rClca2 is associated with epidermal differentiation and is strongly downregulated by ultraviolet radiation
G Bart1, L Hämäläinen, L Rauhala
1Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland.
Background:
Excessive skin exposure to solar radiation damages proteins and DNA, ultimately leading to skin ageing and cancers.
Objectives:
To identify new ultraviolet B (UVB) target genes to understand the mechanisms behind the detrimental effects of UVB.
Methods:
Organotypic, stratified cultures of rat keratinocytes were exposed to UVB and analysed using a genome-wide expression array, quantitative real-time polymerase chain reaction and histology. The most downregulated gene, rClca2, was further characterized in rat keratinocytes and mouse skin models.
Results:
A single, 30 mJ cm(-2) dose of broadband UVB proved effective in the organotypic epidermal culture. The expression of 627 genes was changed 24 h postirradiation. In silico analysis of the data indicated activation of DNA repair, metabolism, cell cycle control and amino acid metabolism, but only limited inflammation under these conditions. We selected for further investigation the most downregulated gene, rClca2, previously suggested to regulate keratinocyte differentiation and adhesion, and found that UVB caused a long-lasting downregulation in its expression. Both the rClca2 full-length isoform (expressed in the differentiating cells) and the truncated isoform (expressed in the basal layers) were reduced by UVB. Immunohistochemistry of mouse skin samples with isoform-specific antibodies showed a similar, epidermal differentiation-related pattern. In mouse specimens exposed to chronic ultraviolet radiation (UVR) the staining intensities were reduced and the differentiation-related isoform was disturbed in the hyperplastic and carcinomatous areas induced by UVR.
Conclusions:
The data show that rClca2 is a novel UVB target gene and suggest that it might play a role in epidermal differentiation and UV-dependent skin malignancies.
Insights
Researchers identified rClca2 as a new gene targeted by ultraviolet B (UVB) radiation. This finding suggests rClca2 plays a role in skin cell differentiation and the development of UV-induced skin cancers.
Area of Science:
- Dermatology
- Molecular Biology
- Genetics
Background:
- Excessive solar radiation damages skin proteins and DNA, leading to premature aging and cancer.
- Ultraviolet B (UVB) radiation is a primary environmental factor contributing to skin damage.
Purpose of the Study:
- To identify novel UVB target genes.
- To elucidate the molecular mechanisms underlying UVB-induced skin damage.
Main Methods:
- Organotypic cultures of rat keratinocytes were exposed to UVB.
- Genome-wide expression arrays and quantitative real-time PCR were employed for gene expression analysis.
- Histology and immunohistochemistry were used to study rClca2 expression in rat and mouse models.
Main Results:
- UVB exposure altered the expression of 627 genes.
- The gene rClca2 was significantly and persistently downregulated by UVB.
- UVB affected both full-length and truncated isoforms of rClca2, impacting keratinocyte differentiation.
- Chronic UV exposure in mice showed reduced rClca2 staining and disturbed differentiation in hyperplastic and cancerous skin areas.
Conclusions:
- rClca2 is identified as a novel UVB target gene.
- rClca2 may be involved in epidermal differentiation processes.
- The downregulation of rClca2 is implicated in UV-dependent skin malignancies.
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