Connexin Expression and Human Skin Development
The major connexins of the human epidermis are Cx26 and Cx43. In human fetal skin more gap junctions are observed as the gestational age increases and more gap junctions are observed in the upper layer.
Fig . (6) : Gap junction distribution during human skin development .
The different stages of wounding are accompanied by striking changes in connexin expression in both the epidermis and dermis, and individual connexins can be correlated with key events in the wound healing process.
Connexins in Skin Disorders (Connexinopathies)
Evidences upon role of connexin in keratinocytes proliferation & differentiation
Wounding of adult rat tail is associated with a strong up-regulation of Cx26 expression in differentiated cells proximal to the wound edge, while the expression of Cx31 and Cx43 declines.
In human skin, tape stripping resulted in an induction of Cx26 expression in a patchy pattern in the basal cell layer that preceded an increase in cell proliferation.
erythematous areas which vary in shape and position over time.
hyperkeratotic , well-defined, more stable plaques.
The lesions have a predilection for the extensor aspects of the limbs, the lateral trunk and the buttocks.
-Hair, teeth and nails are normal.
Fig .(7) : EKV Migratory erythematous lesions Fig. (9) (a) A patient with EKV (b) The same patient after 3 weeks. Note that shapes of the lesions have greatly changed over time. Fig. (8) : EKV Hyperkeratotic fixed plaques on legs and buttocks
In SCC , there was a correlation between staining reactivity and tumor differentiation. Highly differentiated cells are clearly positive, while less differentiated cells are weakly positive for Cx26 and Cx30.
So , based upon the association between connexin proteins and skin diseases, it is highly likely that a good understanding of connexin biology will provide novel therapeutic insights and an exciting challenges for the future ………………….