Diesel Exhaust Particles Impair Therapeutic Effect of Human Wharton’s Jelly-Derived Mesenchymal Stem Cells against Experimental Colitis through ROS/ERK/cFos Signaling Pathway

Background and Objectives@#Epidemiological investigations have shown positive correlations between increased diesel exhaust particles (DEP) in ambient air and adverse health outcomes. DEP are the major constituent of particulate atmospheric pollution and have been shown to induce proinflammatory responses both in the lung and systemically. Here, we report the effects of DEP exposure on the properties of human Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs), including stemness, regeneration, and immunomodulation. @*Methods@#and Results: Non-apoptotic concentrations of DEP (10 μg/ml) inhibited the migration and osteogenic differentiation capacity of WJ-MSCs. Gene expression profiling showed that DEP increased intracellular reactive oxygen species (ROS) and expression of pro-inflammatory and metabolic-process-related genes including cFos. Furthermore, WJ-MSCs cultured with DEP showed impaired suppression of T cell proliferation that was reversed by inhibition of ROS or knockdown of cFos. ERK inhibition assay revealed that DEP-induced ROS regulated cFos through activation of ERK but not NF-κB signaling. Overall, low concentrations of DEP (10 μg/ml) significantly suppressed the stemness and immunomodulatory properties of WJ-MSCs through ROS/ERK/cFos signaling pathways. Furthermore, WJ-MSCs cultured with DEP impaired the therapeutic effect of WJ-MSCs in experimental colitis mice, but was partly reversed by inhibition of ROS. @*Conclusions@#Taken together, these results indicate that exposure to DEP enhances the expression of pro-inflammatory cytokines and immune responses through a mechanism involving the ROS/ERK/cFos pathway in WJ-MSCs, and that DEP-induced ROS damage impairs the therapeutic effect of WJ-MSCs in colitis. Our results suggest that modulation of ROS/ERK/cFos signaling pathways in WJ-MSCs might be a novel therapeutic strategy for DEP-induced diseases.

Direct Conversion of Human Umbilical Cord Blood into Induced Neural Stem Cells with SOX2 and HMGA2

Recent advances have shown the direct reprogramming of mouse and human fibroblasts into induced neural stem cells (iNSCs) without passing through an intermediate pluripotent state. Thus, direct reprogramming strategy possibly provides a safe and homogeneous cellular platform. However, the applications of iNSCs for regenerative medicine are limited by the restricted availability of cell sources. Human umbilical cord blood (hUCB) cells hold great potential in that immunotyped hUCB units can be immediately obtained from public banks. Moreover, hUCB samples do not require invasive procedures during collection or an extensive culture period prior to reprogramming. We recently reported that somatic cells can be directly converted into iNSCs with high efficiency and a short turnaround time. Here, we describe the detailed method for the generation of iNSCs derived from hUCB (hUCB iNSCs) using the lineage-specific transcription factors SOX2 and HMGA2. The protocol for deriving iNSC-like colonies takes 1~2 weeks and establishment of homogenous hUCB iNSCs takes additional 2 weeks. Established hUCB iNSCs are clonally expandable and multipotent producing neurons and glia. Our study provides an accessible method for generating hUCB iNSCs, contributing development of in vitro neuropathological model systems.

Isolation and characterization of canine umbilical cord blood-derived mesenchymal stem cells

Human umbilical cord blood-derived mesenchymal stem cells (MSCs) are known to possess the potential for multiple differentiations abilities in vitro and in vivo. In canine system, studying stem cell therapy is important, but so far, stem cells from canine were not identified and characterized. In this study, we successfully isolated and characterized MSCs from the canine umbilical cord and its fetal blood. Canine MSCs (cMSCs) were grown in medium containing low glucose DMEM with 20% FBS. The cMSCs have stem cells expression patterns which are concerned with MSCs surface markers by fluorescence-activated cell sorter analysis. The cMSCs had multipotent abilities. In the neuronal differentiation study, the cMSCs expressed the neuronal markers glial fibrillary acidic protein (GFAP), neuronal class III beta tubulin (Tuj-1), neurofilament M (NF160) in the basal culture media. After neuronal differentiation, the cMSCs expressed the neuronal markers Nestin, GFAP, Tuj-1, microtubule-associated protein 2, NF160. In the osteogenic & chondrogenic differentiation studies, cMSCs were stained with alizarin red and toluidine blue staining, respectively. With osteogenic differentiation, the cMSCs presented osteoblastic differentiation genes by RT-PCR. This finding also suggests that cMSCs might have the ability to differentiate multipotentially. It was concluded that isolated MSCs from canine cord blood have multipotential differentiation abilities. Therefore, it is suggested that cMSCs may represent a be a good model system for stem cell biology and could be useful as a therapeutic modality for canine incurable or intractable diseases, including spinal cord injuries in future regenerative medicine studies.