Human Fetal Pigmented Ciliary Epithelium Stem Cells have Regenerative Capacity in the Murine Retinal Degeneration Model of Laser Injury.

BACKGROUND: Retinal degeneration and related eye disorders have limited treatment interventions. Since stem cell therapy has shown promising results, ciliary epithelium (CE) derived stem cells could be a better choice given the fact that cells from eye niche can better integrate with the degenerating retina, rewiring the synaptic damage. OBJECTIVE: To test the effect of human fetal pigmented ciliary epithelium-derived neurospheres in the mouse model of laser-induced retinal degeneration. METHODS: C57 male mice were subjected to retinal injury by Laser photocoagulation. Human fetal pigmented ciliary epithelium was obtained from post-aborted human eyeballs and cultured with epidermal growth factor (rhEGF) and fibroblast growth factor (rhFGF). The six day neurospheres were isolated, dissociated and transplanted into the subretinal space of the laser injured mice at the closest proximity to Laser shots. Mice were analyzed for functional vision through electroretinogram (ERG) and sacrificed at 1 week and 12 week time points. Retinal, Neurotropic, Apoptotic and proliferation markers were analysed using real-time polymerase chain reaction (PCR). RESULTS: The CE neurospheres showed an increase in the expression of candidate genes analyzed in the study at 1 week time point, which sustained for longer time point of 12 weeks. CONCLUSION: We showed the efficacy of human CE cells in the regeneration of retinal degeneration in murine model for the first time. CE cells need to be explored comprehensively both in disease and degeneration.

Attenuating spinal cord injury by conditioned medium from human umbilical cord blood-derived CD34⁺ cells in rats.

OBJECTIVE: Intravenous or intraspinal transplantation of human umbilical cord blood cells-derived CD34(+) cells (human CD34(+) cells) or mesenchymal stem cells after spinal cord injury (SCI) improved hind limb functional recovery in adult rats. The objective of this study is to ascertain whether SCI in rats can be attenuated by conditioned medium (CM) or secretome obtained from cultured human CD34(+) stem cells. MATERIALS AND METHODS: Sprague-Dawley rats were assigned to one of the following five groups: the sham group, the SCI group treated with vehicle solution (SCI + V), the SCI group treated with CM (SCI + CM), the SCI group treated with 17ß-estradiol E2 (10 µg; SCI + E2), and the SCI group treated with CM plus E2 (SCI + CM + E2). A 0.5-mL volume of CM or vehicle solution was administered intravenously immediately after SCI. RESULTS: Compared with the sham group, the (SCI + V) group had significantly higher scores of neurological motor dysfunction as well as inflammation apoptosis, oxidative stress, and astrogliosis in the injured spinal cord. The neurological deficits, numbers of apoptotic cell, extent of inflammation, oxidative stress, and astrogliosis in the injured spinal cord were significantly attenuated by CM, E2, or CM plus E2, but not by the vehicle solution. In addition, the neuroprotective effect exerted by a combination of CM and E2 is superior to that exerted by CM- or E2-alone therapy. CONCLUSION: The neuroprotective effects of CM from cultured human CD34(+) cells are similar to those of human CD34(+) cells and the CM was found to enhance the neuroprotective effects of E2 in rat SCI.

Phenotypic and in vivo functional characterization of immortalized human fetal liver cells.

We report the establishment and characterization of immortalized human fetal liver progenitor cells by expression of the Simian virus 40 large T (SV40 LT) antigen. Well-characterized cells at various passages were transplanted into nude mice with acute liver injury and tested for functional capacity. The SV40LT antigen-immortalized fetal liver cells showed a morphology similar to primary cells. Cultured cells demonstrated stable phenotypic expression in various passages, of hepatic markers such as albumin, CK 8, CK18, transcription factors HNF-4α and HNF-1α and CYP3A/7. The cells did not stain for any of the tested cancer-associated markers. Albumin, HNF-4α and CYP3A7 expression was confirmed by reverse transcription polymerase chain reaction (RT-PCR). Flow cytometry showed expression of some progenitor cell markers. In vivo study showed that the cells expressed both fetal and differentiated hepatocytes markers. Our study suggests new approaches to expand hepatic progenitor cells, analyze their fate in animal models aiming at cell therapy of hepatic diseases.

Involvement of placental/umbilical cord blood acid-base status and gas values on the radiosensitivity of human fetal/neonatal hematopoietic stem/progenitor cells.

Arterial cord blood (CB) acid-base status and gas values, such as pH, PCO2, PO2, HCO3(-)and base excess, provide useful information on the fetal and neonatal condition. However, it remains unknown whether these values affect the radiosensitivity of fetal/neonatal hematopoiesis. The present study evaluated the relationship between arterial CB acid-base status, gas values, and the radiosensitivity of CB hematopoietic stem/progenitor cells (HSPCs). A total of 25 CB units were collected. The arterial CB acid-base status and gas values were measured within 30 min of delivery. The CD34(+)HSPCs obtained from CB were exposed to 2 Gy X-irradiation, and then assayed for colony-forming unit-granulocyte-macrophage, burst-forming unit-erythroid (BFU-E), and colony-forming unit-granulocyte erythroid, macrophage and megakaryocyte cells. Acid-base status and gas values for PCO2and HCO3(-)showed a statistically significant negative correlation with the surviving fraction of BFU-E. In addition, a significant positive correlation was observed between gestational age and PCO2. Moreover, the surviving fraction of BFU-E showed a significant negative correlation with gestational age. Thus, HSPCs obtained from CB with high PCO2/HCO3(-)levels were sensitive to X-irradiation, which suggests that the status of arterial PCO2/HCO3(-)influences the radiosensitivity of fetal/neonatal hematopoiesis, especially erythropoiesis.

Bone marrow-engrafted cells after mice umbilical cord blood transplantation differentiate into osteoblastic cells in response to fracture and placement of titanium screws.

As the in vivo function of bone marrow-engrafted umbilical cord blood (UCB)-derived mesenchymal cells (UCBCs) after UCB transplantation is unknown, we examined in vivo osteoblastic differentiation using mouse UCB transplantation and fracture models. UCBCs obtained from GFP transgenic mice were intravenously injected into irradiated C57BL/6 mice. After three months, the in vivo osteoblastic differentiation potential of bone marrow-engrafted UCBCs was examined histologically using a mouse fracture model. GFP-positive UCBCs were detected in the bone marrow of recipient mice. On day 7, UCBCs were observed in the fracture gap and surrounding the titanium screws of the fixation device. The UCBCs were also positive for alkaline phosphatase and von Kossa staining. By day 14, UCBCs were observed around and within a formed intramedullary callus. The newly formed woven bone consisted of ALP- and von Kossa-positive cells. Our findings suggest that UCBCs contribute to the fracture healing process after bone marrow engraftment and that UCBC transplantation can fully reconstruct not only hematopoietic cells but also mesenchymal cell lineages.

Fetal BM-derived mesenchymal stem cells promote the expansion of human Th17 cells, but inhibit the production of Th1 cells.

Th type 17 (Th17) cells have been identified as a proinflammatory T-cell subset. Here, we investigated the regulation of human Th17 cells by fetal BM-derived mesenchymal stem cells (FBM-MSC). We cocultured FBM-MSC with human PBMC or CD4(+) T cells from healthy donors. FBM-MSC significantly suppressed the proliferation of CD4(+) T cells stimulated by PHA and recombinant IL-2. Significantly higher levels of IL-17 were observed in FBM-MSC cocultured with either PBMC or CD4(+) T cells than that in PBMC cultured alone or CD4(+) T cells cultured alone. Flow cytometry analysis showed that the percentage of Th17 cells in coculture of FBM-MSC and CD4(+) T cells was significantly higher than that in CD4(+) T-cell cultured alone. FBM-MSC did not express IL-17 protein. Consistent with the augmentation of Th17 cells, significantly higher levels of IL-6 and IL-1 were observed in coculture of FBM-MSC and CD4(+) T cells than that in CD4(+) T-cell culture, while the levels of IL-23 were similar between FBM-MSC + PBMC coculture and PBMC alone, or FBM-MSC + CD4(+) T-cell and CD4(+) T-cell alone. The presence of FBM-MSC decreased the percentage of Th1 cells, but minimally affected the expansion of CD4(+)CD25(+) T cells. In conclusion, our data demonstrate for the first time that FBM-MSC promote the expansion of Th17 cells and decrease IFN-gamma-producing Th1 cells. These data suggest that IL-6 and IL-1, instead of IL-23, may be partly involved in the expansion of Th17 cells.

Microgel iron oxide nanoparticles for tracking human fetal mesenchymal stem cells through magnetic resonance imaging.

Stem cell transplantation for regenerative medicine has made significant progress in various injury models, with the development of modalities to track stem cell fate and migration post-transplantation being currently pursued rigorously. Magnetic resonance imaging (MRI) allows serial high-resolution in vivo detection of transplanted stem cells labeled with iron oxide particles, but has been hampered by low labeling efficiencies. Here, we describe the use of microgel iron oxide (MGIO) particles of diameters spanning 100-750 nm for labeling human fetal mesenchymal stem cells (hfMSCs) for MRI tracking. We found that MGIO particle uptake by hfMSCs was size dependent, with 600-nm MGIO (M600) particles demonstrating three- to sixfold higher iron loading than the clinical particle ferucarbotran (33-263 versus 9.6-42.0 pg iron/hfMSC; p < .001). Cell labeling with either M600 particles or ferucarbotran did not affect either cellular proliferation or tri-lineage differentiation into osteoblasts, adipocytes, and chondrocytes, despite differences in gene expression on a genome-wide microarray analysis. Cell tracking in a rat photothrombotic stroke model using a clinical 1.5-T MRI scanner demonstrated the migration of labeled hfMSCs from the contralateral cortex to the stroke injury, with M600 particles achieving a five- to sevenfold higher sensitivity for MRI detection than ferucarbotran (p < .05). However, model-related cellular necrosis and acute inflammation limited the survival of hfMSCs beyond 5-12 days. The use of M600 particles allowed high detection sensitivity with low cellular toxicity to be achieved through a simple incubation protocol, and may thus be useful for cellular tracking using standard clinical MRI scanners.

[Flow cytometry analysis and differentiation study of selected nestin positive cells].

OBJECTIVE: To verify the hypothesis that selected nestin positive cells derived from human fetal pancreas (according as medical ethnics) have surface markers similar to bone marrow mesenchymal stem cells (MSCs), and that these cells have multilineage potential. METHOD: The cell surface markers were determined by flow cytometry, and then the potential that these cells might be differentiated into adipocytes and osteoplasts were explored. RESULT: These cells have similar surface markers as MSCs of bone marrow origin. These cells was induced to differentiate into adipocytes and osteoplasts. CONCLUSION: Selected nestin positive cells derived from human fetal pancreas have certain characteristics of MSCs.