RESUMO
Adipose-derived stromal/stem cells (ASCs) are promising candidates for cell-based therapies. However, the lack of markers able to unequivocally identify these cells, the differential expression of cell surface molecules among stromal progenitors from different tissues and cellular alterations caused by culture are phenomena that need to be comprehensively addressed in order to improve ASC purification and consequently refine our knowledge about their function and therapeutic efficiency. In this study, we investigated the potential of CD271, a marker used for purification of bone marrow-derived mesenchymal stem cells, on enriching ASCs from CD34+ stromal cells of human adipose tissue. Putative ASC populations were sorted based on CD271 expression (CD45- CD31- CD34+ CD271+ and CD45- CD31- CD34+ CD271- cells) and compared regarding their clonogenic efficiency, proliferation, immunophenotypic profile, and multilineage potential. To shed light on their native identity, we also interrogated the expression of key perivascular cell markers in freshly isolated cells. CD271- cells displayed twofold higher clonogenic efficiency than CD271+ cells. Upon culture, the progeny of both populations displayed similar immunophenotypic profile and in vitro adipogenic and chondrogenic potentials, while CD271+ cells produced more calcified extracellular matrix. Interestingly, uncultured freshly isolated CD271+ cells displayed higher expression of pericyte-associated markers than CD271- cells and localized in the inner region of the perivascular wall. Our results demonstrate that cells with in vitro ASC traits can be obtained from both CD271+ and CD271- stromal populations of human adipose tissue. In addition, gene expression profiling and in situ localization analyses indicate that the CD271+ population displays a pericytic phenotype.
Assuntos
Tecido Adiposo/metabolismo , Antígenos CD34/metabolismo , Regulação da Expressão Gênica , Proteínas do Tecido Nervoso/biossíntese , Receptores de Fator de Crescimento Neural/biossíntese , Tecido Adiposo/citologia , Adulto , Feminino , Humanos , Masculino , Células Estromais/citologia , Células Estromais/metabolismoRESUMO
The typical characteristics of mesenchymal stem cells (MSCs) can be affected by inflammatory microenvironment; however, the exact contribution of HTLV-1 to MSC dysfunction remains to be elucidated. In this study, we demonstrated that MSC cell surface molecules VCAM-1 and ICAM-1 are upregulated by contact with HTLV-1, and HLA-DR was most highly expressed in MSCs co-cultured with MT2 cells. The expression levels of VCAM-1 and HLA-DR were increased in MSCs cultured in the presence of PBMCs isolated from HTLV-1-infected symptomatic individuals compared with those cultured with cells from asymptomatic infected individuals or healthy subjects. HTLV-1 does not impair the MSC differentiation process into osteocytes and adipocytes. In addition, MSCs were efficiently infected with HTLV-1 in vitro through direct contact with HTLV-1-infected cells; however, cell-free virus particles were not capable of causing infection. In summary, HTLV-1 can alter MSC function, and this mechanism may contribute to the pathogenesis of this viral infection.