Induction of gap junctional intercellular communication by vitamin D in human skin fibroblasts is dependent on the nuclear Induction of gap junctional intercellular communication by vitamin D in human skin fibroblasts is dependent on the nuclear vitamin D receptor.

The physiologically active metabolite of vitamin D, 1alpha,25-dihydroxyvitamin D3 (calcitriol), induces gap junctional intercellular communication in human skin fibroblasts 161BR at a concentration of 10(-7) M. In human skin fibroblasts, FIB5, devoid of a functional nuclear vitamin D receptor (VDR), there is no effect on gap junctional intercellular communication. Parallel to the increase in cell-cell communication, we observed a VDR-dependent increase in connexin43 protein and connexin43 mRNA levels. These results suggest that 1alpha,25-dihydroxyvitamin D3 affects gap junctional intercellular communication at the level of transcription or of mRNA stability via the nuclear VDR.