Lectin Profile Variation in Mesenchymal Stem Cells Derived from Different Sources.

Human mesenchymal stem cells (MSCs), a promising source of stem cells for regenerative medicine, have different morphological and functional characteristics. Carbohydrate moieties on the cell surface play an important role, including cell-cell interaction and cell recognition. The objective of this study was to determine possible differences in glycoconjugate distribution patterns of MSCs derived from various sources. MSCs were isolated from adipose tissue, bone marrow, Wharton's jelly, and cord blood. Then, they were stained with FITC-conjugated wheat germ agglutinin (WGA), peanut agglutinin (PNA), concanavalin A (ConA), Ulex europaeus (UEA), Dolichos biflorus (DBA), and Atto-488 conjugated Phytolacca americana (PWM) lectins. The intensity of the reactions was scored using ImageJ software. Flow cytometry was performed to detect the expression of the endothelial marker CD144. The obtained data were analyzed by ANOVA and LSD. Cord blood-derived MSCs showed the most significant staining intensities with all lectins. All MSCs were also moderately stained with PNA. Bone marrow-derived MSCs failed to react with UEA, DBA, and ConA. Wharton's jelly-derived MSCs could also not be stained with ConA. Cord blood-derived MSCs contained 2 subpopulations: osteoclast- and fibroblast-like cells. Both lectin staining intensity and distribution pattern were different in these 2 cell types; therefore, the central part of osteoclast-like cells stained more intensive with PNA and PWM, while that part in fibroblast-like cells stained more intensive with ConA. None of them expressed CD144. The glycoconjugate content of MSCs derived from various sources is different.

Heparin/Collagen 3D Scaffold Accelerates Hepatocyte Differentiation of Wharton's Jelly-Derived Mesenchymal Stem Cells.

Both mature and stem cell-derived hepatocytes lost their phenotype and functionality under conventional culture conditions. However, the 3D scaffolds containing the main extracellular matrix constitutions, such as heparin, may provide appropriate microenvironment for hepatocytes to be functional. The current study aimed to investigate the efficacy of the differentiation capability of hepatocytes derived from human Wharton's jelly mesenchymal stem cells (WJ-MSCs) in 3D heparinized scaffold. In this case, the human WJ-MSCs were cultured on the heparinized and non-heparinized 2D collagen gels or within 3D scaffolds in the presence of hepatogenic medium. Immunostaining was performed for anti-alpha fetoprotein, cytokeratin-18 and -19 antibodies. RT-PCR was performed for detection of hepatic nuclear factor-4 (HNF-4), albumin, cytokeratin-18 and -19, glucose-6-phosphatase (G6P), c-met and Cyp2B. The results indicated that hepatogenic media induced the cells to express early liver-specific markers including HNF4, albumin, cytokeratin-18 and 19 in all conditions. The cells cultured on both heparinized culture conditions expressed late liver-specific markers such as G6P and Cyp2B as well. Besides, the hepatocytes differentiated in 3D heparinized scaffolds stored more glycogen that indicated they were more functional. Non-heparinized 2D gel was the superior condition for cholangiocyte differentiation as indicated by higher levels of cytokeratin 19 expression. In conclusion, the heparinized 3D scaffolds provided a microenvironment to mimic Disse space. Therefore, 3D heparinized collagen scaffold can be suggested as a good vehicle for hepatocyte differentiation.

Differentiation Potential of Breast Milk-Derived Mesenchymal Stem Cells into Hepatocyte-Like Cells.

Human breast milk stem cells (hBSCs) contain a population of cells with the ability to differentiate into various cell lineages for cell therapy applications. The current study examined the differentiation potential of hBSCs into hepatocytes-like cells. The cells were isolated from the breast milk and were treated with hepatogenic medium containing hepatocyte growth factor, insulin-like growth factor and dexamethasone for 7 days subsequently; Oncostatin M was added to the culture media. RT-PCR and immunocytochemistry were performed to detect the hepatogenic markers. The glycogen storage and the ability of the cells to absorb and release indocynanin green were also tested. The data showed that most of the differentiated cells formed cell aggregates after the 30th day, with more cells accumulated to form spheroids. RT-PCR revealed the expression of the hepatic nuclear factor, albumin, cytokeratin 18 and 19, cytochrome P2B6, glucose-6-phospahtase and claudin. The functional assays also showed glycogen storage and omission of indicynine green. Our study demonstrated hBSCs are novel population that can differentiate into hepatocyte-like cells.

Origins of the breast milk-derived cells; an endeavor to find the cell sources.

Fresh human breast milk consists of a heterogeneous population of cells that may offer a non-invasive source of cells for therapeutic proposes. The aims of this study were to characterize the breast milk-derived cells cultured in vitro. To do this, the cells from human breast milk were cultured and the expression of the CD markers along with the embryonic stem cell markers, endothelial and luminal mammary epithelial cell markers was evaluated by flow cytometry and immunofluorescence. The presence of fetal microchimerism among the isolated cells was also determined by the presence of SRY gene. They were also differentiated into adipocytes and osteoblasts. The results showed that a remarkable number of cells expressed the mesenchymal stem cell (MSC) markers such as CD90, CD44, CD271, and CD146. A subpopulation of the human breast milk-derived cells (HBMDC) also expressed the embryonic stem cell markers, such as TRA 60-1, Oct4, Nanog and Sox2 but not SSEA1 or 4. The frequencies of the cells which expressed the endothelial, hematopoietic cell markers were negligible. SRY gene was not detected in the breast milk isolated cells. A subpopulation of the cells also expressed cytokeratin 18, the marker of luminal mammary epithelial cells. These cells showed the capability to differentiate into adipocytes and osteoblasts. In conclusion, these finding highlighted the presence of cells with various sources in the breast milk. Different stem cells including MSCs or embryonic stem cell-like cell along with the exfoliated cells from luminal epithelial cells were found among the isolated cells. The breast milk-derived stem cells might be considered as a non-invasive source of the stem cells for therapeutic purpose.