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Updated: Jul 4, 2026

Generation and Culturing of Primary Human Keratinocytes from Adult Skin
Published on: December 22, 2017
Claudin 2 mRNA and protein are present in human keratinocytes and may be regulated by all-trans-retinoic acid
D Telgenhoff1, S Ramsay, S Hilz
1DFB Branded Pharmaceuticals, Central Research Division, Fort Worth, Tex. 76017, USA. Dale.Telgenhoff@dfb.com
Abstract:
Tight junctions are composed of claudins, occludins, junctional adhesion molecules and plaque proteins. Claudin 2 protein forms a cation-selective channel which confers increased permeability in renal epithelial cells and in the intestine where its expression is restricted to the leaky epithelium. Immunohistochemical staining revealed claudin 2 staining in the granular layer of adult epidermis. Analysis of Western blots revealed bands corresponding to the molecular weight of claudin 2 in Madin-Darby canine kidney II cells, human kidney, adult skin and neonatal keratinocytes. Reverse transcriptase polymerase chain reaction on mRNA and cDNA sequence analysis found a 99% sequence homology between our cDNA and human claudin 2 (NIH BLAST sequence). Further, we show that all-trans-retinoic acid increases the expression of claudin 2 in keratinocytes in a dose-dependent manner. The discovery of claudin 2 transcript and protein in the skin could be of importance in epidermal differentiation, barrier function and pathological conditions.
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