Study of expression of α-SMA in dermal cells of skin appendages by immunohistochemistry

Alpha smooth muscle actin (α-SMA) is an actin isoform present in many kinds of eukaryotic cells. In this survey the expression of this protein in skin appendages was examined. In present study we examined the expression of this protein in 3 populations of dermal cells derived from three different skin appendages in vitro and in one case in situ by means of immunohistochemistry.Observations: The results obtained here showed that in culture this protein is expressed nearly in all dermal papilla cells derived from vibrissa follicles. In case of dermal cells derived from claw unit a high percentage of cells expressed the protein, but in feather follicles only a small percentage of dermal papilla cells were positive for this protein. The α-SMA was also strongly expressed in dermal components reside at basal region of feather follicles in situ. Here we report for the first time that α-SMA is expressed in cultured dermal cells of claw and feather follicle. Moreover, these findings along with the results provided by other workers reinforce the crucial role of this protein in normal activities of skin and cutaneous appendages in mammals and other vertebrates. Given to a high expression of this protein in dermal cells of feather follicle particularly in situ, it can be concluded that α-SMA plays a more important role in birds compared to its role in hair follicle of mammals but the exact role of this protein needs to be elucidated.