Introduction. Mesenchymal stem cells (MSCs) are a promising tool for regenerative medicine, but due to the heterogeneity of their populations, different sources and isolation techniques, the characteristics defining MSCs are inconsistent. Objective. The aim of this study was to compare the characteristics of MSCs derived from two different human tissues: peripheral blood (PB-MSCs) and umbilical cord Wharton?s Jelly (UC-MSCs). Methods. The PB-MSC and UC-MSC were isolated by adherence to plastic after gradient-density separation or an explant culture method, respectively, and compared regarding their morphology, clonogenic efficiency, proliferating rates, immunophenotype and differentiation potential. Results. MSCs derived from both sources exhibit similar morphology, proliferation capacity and multilineage (osteogenic, chondrogenic, adipogenic and myogenic) differentiation potential. Differences were observed in the clonogenic capacity and the immunophenotype, since UC-MSCs showed higher CFU-F (colony-forming units-fibroblastic) cloning efficiency, as well as higher embryonic markers (Nanog, Sox2, SSEA4) expression. When additional surface antigens were analyzed by flow cytometry (CD44, CD90, CD105, CD33, CD34, CD45, CD11b, CD235a) or immunofluorescent labeling (vimentin, STRO-1 and ?-smooth muscle actin), most appeared to have similar epitope profiles irrespective of MSC source. Conclusion. The results obtained demonstrated that both MSCs represent good alternative sources of adult MSCs that could be used in cell therapy applications.

Hemoglobin is essential for maintaining cellular bioenergetic homeostasis through its ability to bind and transport oxygen to the tissues. Besides its ability to transport oxygen, hemoglobin within erythrocytes plays an important role in cellular signaling and modulation of the inflammatory response either directly by binding gas molecules (NO, CO, and CO₂) or indirectly by acting as their source. Once hemoglobin reaches the extracellular environment, it acquires several secondary functions affecting surrounding cells and tissues. By modulating the cell functions, this macromolecule becomes involved in the etiology and pathophysiology of various diseases. The up-to-date results disclose the impact of extracellular hemoglobin on (i) redox status, (ii) inflammatory state of cells, (iii) proliferation and chemotaxis, (iv) mitochondrial dynamic, (v) chemoresistance and (vi) differentiation. This review pays special attention to applied biomedical research and the use of non-vertebrate and vertebrate extracellular hemoglobin as a promising candidate for hemoglobin-based oxygen carriers, as well as cell culture medium additive. Although recent experimental settings have some limitations, they provide additional insight into the modulatory activity of extracellular hemoglobin in various cellular microenvironments, such as stem or tumor cells niches.

Mesenchymal stem cells from human adipose tissue (hASCs) are proposed as suitable tools for soft tissue engineering and reconstruction. Although it is known that hASCs have the ability to home to sites of inflammation and tumor niche, the role of inflammatory cytokines in the hASCs‐affected tumor development is not understood. We found that interferon‐γ (IFN‐γ) and/or tumor necrosis factor‐α (TNF‐α) prime hASCs to produce soluble factors which enhance MCF‐7 cell line malignancy in vitro. IFN‐γ and/or TNF‐α‐primed hASCs produced conditioned media (CM) which induced epithelial to mesenchymal transition (EMT) of MCF‐7 cells by reducing E‐Cadherin and increasing Vimentin expression. Induced EMT was accompanied by increased invasion, migration, and urokinase type‐plasminogen activator (uPA) expression in MCF‐7 cells. These effects were mediated by increased expression of transforming growth factor‐β1(TGF‐β1) in cytokines‐primed hASCs, since inhibition of type I TGF‐β1 receptor on MCF‐7 cells and neutralization of TGF‐β1 disabled the CM from primed hASCs to increase EMT, cell migration, and uPA expression in MCF‐7 cells. Obtained data suggested that IFN‐γ and/or TNF‐α primed hASCs might enhance the malignancy of MCF‐7 cell line by inducing EMT, cell motility and uPA expression in these cells via TGF‐β1‐Smad3 signalization, with potentially important implications in breast cancer progression. © 2016 IUBMB Life, 68(3):190–200, 2016