Variations in gap junctional intercellular communication and connexin expression in fibroblasts derived from keloid and hypertrophic scars

Background: Expression of connexins and other constituent proteins of gap junctions along with gap junctional intercellular communication are involved in cellular development and differentiation processes. In addition, an increasing number of hereditary skin disorders appear to be linked to connexins. Therefore, in this report, the authors studied in vitro gap junctional intercellular communication function and connexin expression in fibroblasts derived from keloid and hypertrophic scar patients. Methods: Fibroblasts harvested from each of six keloid and hypertrophic scar patients were used for this study. Gap junctional intercellular communication function was investigated using the gap fluorescence recovery after photo-bleaching method, and expression of connexin proteins was studied using quantitative confocal microscopic analyses. Results: Compared with normal skin, a decreased level of gap junctional intercellular communication was seen in fibroblasts derived from hypertrophic scar tissue, whereas an extremely low gap-junctional intercellular communication level was detected in fibroblasts derived from keloid tissue. We also detected little connexin 43 (Cx43) protein localized in fibroblasts derived from keloids. Moreover, Cx43 protein levels were much lower in fibroblasts derived from hypertrophic scars than in those derived from normal skin. Conclusions: The authors' data suggest that the loss of gap junctional intercellular communication and connexin expression may affect intercellular recognition and thus break the proliferation and apoptosis balance in fibroblasts derived from keloid and hypertrophic scar tissue.