Effects Of Hypoxia in Long-Term In Vitro Expansion of Human Bone Marrow Derived Mesenchymal Stem Cells.

Mesenchymal stem cells (MSC) are considered multipotent stromal, non-hematopoietic cells with properties of self-renovation and differentiation. Optimal conditions for culture of MSC have been under investigation. The oxygen tension used for cultivation has been studied and appears to play an important role in biological behavior of mesenchymal cells. The aim is characterize MSC in hypoxia and normoxia conditions comparing their morphological and functional characteristics. Bone marrow-derived mesenchymal stem cells obtained from 15 healthy donors and cultured. MSC obtained from each donor were separated into two cultivation conditions normoxia (21% O2 ) and hypoxia (three donors at 1%, three donors at 2%, five donors at 3%, and four donors at 4% O2 ) up to second passage. MSC were evaluated for proliferation, differentiation, immunophenotyping, size and cell complexity, oxidative stress, mitochondrial activity, and autophagy. Culture conditions applied did not seem to affect immunophenotypic features and cellular plasticity. However, cells subjected to hypoxia showed smaller size and greater cellular complexity, besides lower proliferation (P < 0.002). Furthermore, cells cultured in low O2 tension had lower mitochondrial activity (P < 0.03) and a reduced tendency to autophagy, although oxidative stress did not vary among groups (P < 0.39). Oxygen tension seems to be a key regulator of cellular adaptation in vitro, and metabolic effects underlying this variable remain undescribed. Heterogeneity or even lack of results on the impact of oxygen concentration used for expanding MSC highlights the need for further research, in order to optimize conditions of cultivation and expansion and achieve greater safety and therapeutic efficacy. J. Cell. Biochem. 118: 3072-3079, 2017. © 2017 Wiley Periodicals, Inc.

Células-tronco mesenquimais: caracterização, cultivo, propriedades imunológicas e aplicações clínicas / Mesenchymal stem cells: characterization, cultivation, immunological properties and clinical applications

As células-tronco mesenquimais (CTM) são consideradas células multipotentes não hematopoéticas com propriedades de autorrenovação e capacidade de diferenciação em tecidos mesenquimais e, possivelmente, em não mesenquimais. Vários estudos recentes têm reforçado o caráter multipotente destas células pela capacidade de diferenciarem-se em células derivadas da mesoderma embrionário: osteócitos, condroblastos e adipócitos. Devido ao fácil isolamento e cultivo, potencial de diferenciação e produção de fatores de crescimento e citocinas, as CTMs têm se tornado as candidatas ideais para os protocolos da medicina regenerativa. Este artigo revisa as principais características dessa célula, forma de obtenção e cultivo, propriedades imunológicas e aplicações clínicas.

Mesenchymal stem cells (MSC) are nonhematopoietic multipotent cells with selfrenewal properties and the ability to differentiate into mesenchymal tissues and possibly nonmesenchymal cells. Several lines of evidence in the past few years have confirmed the ability of these cells to differentiate into cells derived from embryonic mesoderm, such as osteocytes, adipocytes and chondroblasts. Because they are easy to isolate and culture and due to their differentiation potential and production of growth factors and cytokines, MSC have become ideal candidates for regenerative medicine protocols. This study reviews the main characteristics of MSC, how to isolate and culture them, and their immunological properties and clinical applications.