O#18   DSC-1 expression in human anagen hair follicle: an ultrastructural study

Elena Donetti, Elena Boschini, Silvia Selleri, Cristiano Rumio, Paolo Castano, Anna Marcucci, Isabella Barajon. Dept of Human Anatomy, Università degli Studi di Milano, Italy

Similarly to other stratified epithelia, keratinocytes of the human hair follicle (HF) undergo a vertical terminal differentiation program (TD) characterized by complex reorganization of cytoskeleton, chromatin condensation, and desmosomal modifications. Evidence has emerged that, in the inner root sheath (IRS) of HF, the modulation of the expression of desmosomal cadherins, i.e desmocollins and desmogleins, occurs during TD. DSC1 is one of the desmosomal cadherins deeply involved during TD in stratified epithelia. However, structural/ultrastructural features of keratinizing cells have never been correlated with the molecular composition of desmosomes. In the present study, we investigated by post-embedding immunogold electron microscopy the expression of DSC1 during the rearrangement of desmosomes in between cells of the same layer (homojunctions) and in between cells of adjacent layer (heterojunctions)