The potential role of skin protein kinase C isoforms alpha and delta in mouse hair growth induced by diphencyprone-allergic contact dermatitis.

Abstract

The levels of protein kinase C (PKC) isoforms alpha and delta in mouse hair growth induced by diphencyprone (DPCP)-allergic contact dermatitis (ACD) were studied. BALB/c mice were sensitized by 2% DPCP in acetone on one side of their shaved backs and rechallenged with 0.1% DPCP on the same side weekly for 2 weeks. The opposite side treated with acetone served as a control. Before each elicitation, mice were shaved again in order to observe the hair growth that followed. Enhancement of hair growth on DPCP treated skin was observed in 94% of mice after first elicitation and significant hair growth was shown in all mice after second elicitation. No remarkable hair growth was seen on the control side. Western immunoblot analysis revealed that the level of skin PKC alpha on the DPCP treated side was decreased at 2 and 4 days after sensitization and returned to the control level after first elicitation. At 5 days after the second elicitation, a higher level of PKC alpha was detected. The level of PKC delta remained at the control level and increased at 5 days after second elicitation. These results suggest that: 1) In the first week after sensitization, PKC alpha was down-regulated. This down-regulation may play a role in DPCP-ACD induced hair growth; 2) after the elicitation, PKC alpha was over-expressed and this over-expression was roughly correlated with the enhancement of mouse hair growth, suggesting that over-expression of PKC alpha may also play a part in the proliferation of hair follicle cells; and 3) overexpression of PKC delta after second elicitation may have an inhibitory effect on hair growth that keeps hair growth in balance.