Current Stem Cell Research & Therapy - Volume 9, Issue 4, 2014

Bone marrow stromal cells (BMSCs) were considered as one of the strongest candidates for cell transplantations to treat neurological disorders. Previously, we had showed that BMSCs isolated from rats could be induced to differentiate into neural cells being cocultured with olfactory ensheathing cells (OECs). In this study, we further demonstrated the neural differentiation of human BMSCs (hBMSCs) when cocultured with OECs and daily supplement of bFGF (basic fibroblast growth factor). Transwell culture dishes with a 0.4-mm pore size were used to coculture hBMSCs and OECs. At different time points (12h, 24h, 3d, 7d, 14d), the induced hBMSCs were morphologically observed and performed immunocytofluorescence and quantitative RT-PCR (qRT-PCR). The number of neural markers-positive cells significantly increased after coculture, and gene expression of NSE, β-III-tubulin, MAP2, GFAP also dramatically increased. Our study suggested that hBMSCs could be induced into neuron-like cells under conditions of coculture with OECs and daily supplement of bFGF. The differentiated autologous hBMSCs had a great potential for transplantation to treat CNS lesion.

Lung diseases represent a significant burden of morbidity and mortality worldwide. Current therapies have not proven adequate in the long term and are often associated with significant side effects. There has been recent interest in the regenerative/reparative potential of cell-based therapies, including cells derived from the placental tissues. Amnionderived cells are fetal-derived and characterized by expression profile and differentiative capacity of pluripotent cells. Moreover, because placenta is discarded after delivery, they represent an ethical source for the purposes of regenerative medicine. Amnion-derived cells are endowed with immunomodulatory, anti-inflammatory, anti-scarring and antibacterial properties, which may explain many of the beneficial effects observed with administration of the cells in animal models for a large number of inflammatory diseases. Both human amniotic epithelial cells (hAEC) and mesenchymal stromal cells (hAMSC) have been shown to acquire in vitro and in vivo some characteristics of epithelial cells, i.e. CFTR (cystic fibrosis transmembrane conductance regulator) and surfactant proteins. Administration of hAEC or hAMSC in vivo in the bleomycin-induced lung injury model has proven their therapeutic effects in term of reduction of pulmonary fibrosis and inflammation, as well as recovery of lung mechanical function. Many biological and clinical information have to be gathered before proposing amnion-derived cells in the clinic for the treatment of acute and chronic lung diseases.

Mesenchymal Stromal/Stem Cells from human Wharton’s jelly (WJ-MSC) are an abundant and interesting source of stem cells for applications in cell and tissue engineering. Their fetal origin confers specific characteristics compared to Mesenchymal Stromal/Stem Cells isolated from human bone marrow (BM-MSC). The aim of this work was to optimize WJ-MSC culture conditions for their subsequent clinical use. We focused on the influence of oxygen concentration during monolayer expansion on several parameters to characterize MSC. Our work distinguished WJ-MSC from BM-MSC in terms of proliferation, telomerase activity and adipogenic differentiation. We also showed that hypoxia had a beneficial effect on proliferation potential, clonogenic capacity and to a lesser extent, on HLA-G expression of WJ-MSC during their expansion. Moreover, we reported for the first time an increase in chondrogenic differentiation when WJ-MSC were expanded under hypoxia. In an allogeneic therapeutic context, production of clinical batches requires generating high numbers of MSC whilst maintaining the cells’ properties. Considering our results, hypoxia will be an important parameter to take into account. In addition, the clinical use of WJ-MSC would provide significant numbers of cells with maintenance of their proliferation and differentiation potential, particularly their chondrogenic potential. Due to their chondrogenic differentiation potential, WJ-MSC promise to be an interesting source of MSC for cell therapy or tissue engineering for cartilage repair and/or regeneration

Mesenchymal stem/stromal cells (MSCs) have become the focus of intense research effort over the past 10 years, in an effort to harness their regenerative and immune-modulating capacity for a variety of clinical conditions. In Acute Respiratory Distress Syndrome (ARDS), pre-clinical studies point towards a therapy that modulates multiple aspects of a complex disease process. Almost universally, these cells have demonstrated an immune modulating phenotype, balancing protective host responses with a reduction in damaging inflammation, while enhancing bacterial killing. MSCs also lead to more efficient tissue repair, and MSC-mediated lung tissue repair and regeneration after ARDS are some of the exciting clinical prospects. Recent investigation into the role of endogenous MSCs has led to new insights into MSC physiology and its role in regulating the immune system. However, significant deficits remain in our knowledge regarding the mechanisms of action of MSCs, their efficacy in relevant pre-clinical models, and their safety in critically ill patients. These gaps need to be addressed before the enormous therapeutic potential of stem cells for ALI/ARDS can be realized.

Currently, there are a number of alternatives for bone grafting, though when used correctly they present physical, chemical or biological limitations, which justifies the pursuit for new alternatives for bone regeneration. This study gives a report on the potential for bone regeneration in the use of biodegradable nanofibers from poly (lactic-co-glycolic acid) (PLGA) in association with human mesenchymal stem cells from dental pulp of deciduous teeth (SCDT). Five samples of SCDT were seeded with scaffolds (test) or without scaffolds (control) for cell adhesion and viability assay. To evaluate the ability of the association in promoting bone formation, critical defects were made in the calvarium of rats (n=20), which were then divided into the following groups: I – sham group; II – implant of scaffolds; III – scaffolds/ SCDT; and IV – scaffolds/SCDT. They were kept for 13 days in osteogenic media. After 60 days, the histomorphometric analysis was performed. It was observed that the adherence and viability of SCDT in the control and test group were similar throughout the experiment (p>0.05). The association of scaffolds/SCDT maintained in osteogenic media, showed greater bone formation than the other groups (p<0.05). The study demonstrated that the association of SCDT seeded in biodegradable PLGA scaffolds has the ability to promote bone regeneration in rats, which is a promising alternative for application in regenerative medicine.

Clonogenic neural stem (NS) cell lines grown in adherent cultures have previously been established from embryonic stem cells and fetal and adult CNS in rodents and from human fetal brain and spinal cord. Here we describe the isolation of a new cell line from human fetal striatum (hNS cells). These cells showed properties of NS cells in vitro such as monolayer growth, high proliferation rate and expression of radial glia markers. The hNS cells expressed an early neuronal marker while being in the proliferative state. Under appropriate conditions, the hNS cells were efficiently differentiated to neurons, and after 4 weeks about 50% of the cells were βIII tubulin positive. They also expressed the mature neuronal marker NeuN and markers of neuronal subtypes, GABA, calbindin, and DARPP32. After intrastriatal implantation into newborn rats, the hNS cells survived and many of them migrated outside the transplant core into the surrounding tissue. A high percentage of cells in the grafts expressed the neuroblast marker DCX, indicating their neurogenic potential, and some of the cells differentiated to NeuN+ mature neurons. The human fetal striatum-derived NS cell line described here should be a useful tool for studies on cell replacement strategies in models of the striatal neuronal loss occurring in Huntington’s disease and stroke.

Larynx cancer (LCa) is an aggressive malignancy, which is the second most common malignant neoplasm of head and neck squamous cell carcinoma. Its incidences have been reported to increase and therapeutic options mostly fail to give positive clinical response especially for the advanced LCa cases. In this study we aimed to isolate stem-like cells from freshly resected LCa tumor specimens and characterize them by quantitative real time PCR (qRT-PCR) for expression of cancer stem cell markers including SOX2, OCT4, KLF4, ABCG2, CXCR4 and CD44. Our results showed that CD133(high) cells directly isolated from freshly resected tumor specimens exhibit elevated levels of SOX2, OCT4 and KLF4, and have increased expression levels of ABCG2 and CXCR4, which were associated with resistance of tumors to regular chemotherapeutic reagents. In conclusion, this study offers a useful approach utilizing CD133 to isolate stem cells directly from fresh tissues, which gives the opportunity to develop novel therapeutic tools specifically targeting these cells through their further characterization.

Hematopoietic stem/progenitor cells (HSPC) differentiate in the context of stromal niches producing cells of multiple lineages. Limited success has been achieved in the past with induction of hematopoiesis in vitro. Previously, spleen long-term stromal cultures (LTC) were shown to continuously support restricted hematopoiesis for production of novel dendritic-like cells (LTC-DC). An in vivo equivalent dendritic cell type was then described which is specific for spleen. The in vivo counterpart cell was termed ‘L-DC’ and represents a dendritic-like CD11cloCD11bhiCD8α-MHC-II- cell which differs phenotypically and functionally from monocytes/macrophages and conventional and plasmacytoid DC. Splenic stroma is now shown to maintain HSPC and to support their restricted in vitro differentiation to give this ‘L-DC’ subset. In order to characterise progenitors of this distinct cell type, LTC were analysed for cell subsets produced, and these subsets sorted and assessed for hematopoietic potential in subsequent co-cultures over STX3 stroma. Progenitors were defined as a lineage (Lin)-ckitlo subset reflecting HSPC. Furthermore, when Lin-ckithiSca1+Flt3- HSPC were sorted from bone marrow, they colonised splenic stroma with long-term production of L-DC. The maintenance of HSPC by splenic stroma was confirmed when non-adherent cells collected from LTC showed oligopotent reconstitution of the hematopoietic compartment of lethally irradiated mice. All data support a model whereby spleen houses a niche for HSPC in the resting state, with production of progenitors, and their differentiation to give tissue-specific antigen presenting cells.