Immunohistochemical Study on the Expression of Desmocollin 1 during Skin Development / 대한피부과학회지

BACKGROUND: Desmocollins (Dsc) are calcium-dependent transmembrane glycoproteins of desmosomes that are important in the junction complex of epidermis and maintain structural integrity of the skin from external stressors. Among three Dscs (Dsc 1, 2, 3), Dsc 1 and 3 are distributed on skin. OBJECTIVE: The purpose of this study was to observe the Dsc 1 distribution pattern on the skin and oral mucosa during fetal development. METHODS: Skin was obtained from the sole and scalp of 33 fetuses, ranging from 10 to 37 weeks of gestational age. Immunohistochemical staining was performed on the paraffin-embedded tissue using a Dsc 1 monoclonal antibody. RESULTS: Dsc 1 was expressed in the suprabasal layer but not in the basal layer of the epidermis of the sole at the 10th week of gestation. Thereafter, Dsc 1 expression further increased in the suprabasal layer with initiation of stratification and increased gradually in the granular layers of the sole and scalp epidermis. Dsc 1 was strongly expressed in the superficial layer of the infundibulum and inner root sheath of the hair follicle but was not expressed in the sebaceous cells or other hair components. The eccrine duct epithelium was focally and weakly positive for Dsc 1 expression. Furthermore, Dsc 1 was not expressed in oral mucosa, although the oro-cutaneous portion was strongly expressed in the superficial layer. CONCLUSION: Dsc 1 was strongly expressed in the suprabasal cells of the epidermis during fetal skin development, and expression increased gradually in the granular layer and inner root sheath of the hair follicle. However, Dsc 1 was not expressed in basal cells or in oral mucosa. Dsc 1 may play a role in the maintenance of epithelial integrity as part of desmosomes.

Retinoid Induces the Degradation of Corneodesmosomes and Downregulation of Corneodesmosomal Cadherins: Implications on the Mechanism of Retinoid-induced Desquamation

BACKGROUND: Topical retinoids induce skin fragility. As corneodesmosomes are important adhesion structures in the epidermal cohesion, an effect of retinoids on corneodesmosomes has been suspected. OBJECTIVE: The aim of this study was to investigate the effect of retinoid on the expression of corneodesmosomal components including desmoglein (DSG) 1, desmocollin (DSC) 1, corneodesmosin (CDSN) and kallikrein (KLK)s. METHODS: 2% all-trans-retinol or ethanol was applied to the back of hairless mice for five days, and the structure of the stratum corneum was examined by transmission electron microscopy. The cultured human keratinocytes were treated with all-trans-retinoic acid (RA) in low or high calcium media for 24 hours. RESULTS: Topical retinol increased corneocyte detachment and degradation of corneodesmosomes. RA significantly decreased DSG1 and DSC1 expression at the mRNA and protein levels in keratinocytes that were cultured in both low- and high-calcium media. On the other hand, CDSN mRNA levels did not decrease in low-calcium media or increase in high-calcium media after RA treatment. KLK5 and KLK7 expression did not increase after RA treatment. CONCLUSION: Our results indicate that DSG1 and DSC1 downregulation by RA could be related to the increased degradation of corneodesmosomes and consequent desquamation induced by retinoids.