Mesenchymal Stromal Cells from the Epidermis and Dermis of Psoriasis Patients: Morphology, Immunophenotype, Differentiation Patterns, and Regulation of T Cell Proliferation.

Psoriasis is a skin disease characterized by hyperproliferation of keratinocytes and chronic inflammation. Mesenchymal stem/stromal cells (MSCs) exhibit an immunoregulatory function that can be altered in the skin of these patients. However, to date, the presence and functional capacity of MSCs in the dermis and epidermis of patients with psoriasis have not been fully established. In the present study, we evaluated the presence of MSCs in the skin of patients by obtaining adherent cells from the dermis and epidermis of lesional and nonlesional areas and characterizing them in a comparative manner with corresponding cells obtained from the dermis (HD-MSCs) and epidermis (HE-MSCs) of healthy donors. We determined whether the adherent cells had immunophenotypic profiles and differentiation potentials that were characteristic of MSCs. In addition, we analyzed their immunosuppression function by evaluating their capacity to decrease T cell proliferation. Our results indicate the presence of MSCs in the dermis and epidermis of healthy donors and patients with psoriasis; adherent cells from all skin sources exhibited MSC characteristics, such as expression of CD73, CD90, and CD105 markers and a lack of hematopoietic and endothelial marker expression. However, the cell populations obtained showed differences in differentiation potential toward adipogenic, osteogenic, and chondrogenic lineages. In addition, we observed a low MSC obtention frequency in nonlesional epidermal samples (NLE-MSCs), which also showed alterations in morphology and proliferation rate. Interestingly, MSCs from both the nonlesional dermis (NLD-MSCs) and lesional dermis (LD-MSCs) showed higher HLA class I antigen (HLA-I) expression than HD-MSCs. Moreover, NLD-MSCs showed a low T cell proliferation suppression capacity. In summary, this study demonstrates the presence of MSCs in the epidermis and dermis of patients with psoriasis and suggests that such cells may favor the inflammatory process and thus psoriatic lesion development through high HLA-I expression and low immunosuppression capacity.

Human mesenchymal stromal cells from adult and neonatal sources: comparative analysis of their morphology, immunophenotype, differentiation patterns and neural protein expression.

BACKGROUND: Bone marrow (BM) has been recognized as the main source of mesenchymal stromal cells (MSC); however, MSC have also been detected in umbilical cord blood (UCB) and placenta (PL). In the present study, we obtained MSC from these three sources and characterized them in a comparative manner. METHODS: MSC were obtained from BM, UCB and PL samples and analyzed to determine their morphology, cell-surface antigen (Ag) expression and differentiation potential. Particular emphasis was placed on the expression of neural markers. RESULTS: MSC were detected in 9/9, 11/104 and 5/5 samples from BM, UCB and PL, respectively. MSC populations comprised several morphologically distinct cell types, including neural-like cells. MSC were positive for 'mesenchymal' Ag (CD105, CD73 and CD90), although CD90 expression was very heterogeneous. Interestingly, CD13 expression was high in all three sources. In all cases, MSC showed osteogenic and chondrogenic differentiation; however, UCB MSC showed no adipogenic potential. Furthermore, MSC from UCB produced a different type of cartilage compared with MSC from BM and PL. It is noteworthy that in all three sources we detected the expression of neural proteins without any neural differentiation stimuli. A significant increase in the proportion of neural marker-positive MSC was observed in the presence of neural inducers. DISCUSSION: Our results indicate that PL may prove to be a more appropriate source for obtaining MSC than UCB, and suggest the possibility that a subpopulation of MSC may possess neural potential, which is favored by neural inducers.