Human Embryonic Mesenchymal Stem Cells Research Articles

Influence of Redox-Active Chitosan-Polyaminoxyl Micelles Loaded with Daunorubicin on Activity of Nrf2 Transcription Factor.

A new system for delivery of anthracycline antibiotics based on chitosan-polyaminoxyls (CPA) was studied in a model of non-tumor (human embryonic mesenchymal stem cells) and tumor cells (human hepatocellular carcinoma) in vitro. The presence of CPA micelles considerably suppresses daunorubicin-induced ROS generation in normal cells without affecting this process in tumor cells. CPA micelles do not reduce the cytotoxic effect of daunorubicin and do not prevent its accumulation in cells. The use of CPA significantly increases accumulation of Nrf2 transcription factor in the nuclei of both normal and tumor cells in comparison with free daunorubicin. Increased nuclear translocation of Nrf2 leads to a significant increase in the expression of its target gene TXN1, but not the NQO1, GPX1, and HMOX1 genes, the increased expression of which can lead to the development of resistance to anthracycline antibiotics. Redox-active CPA micelles have great potential for the development of nanoparticles for the transport of anthracycline antibiotics in experimental tumor chemotherapy, and also as promising activators of Nrf2 transcription factor.

Enhancement of angiogenesis and neurogenesis by intracerebroventricular injection of secretome from human embryonic stem cell‐derived mesenchymal stem cells in ischemic stroke model

It is well accepted that the success of mesenchymal stem cells (MSCs) therapy against experimental stroke is mainly due to cellular paracrine manners rather than to replace lost tissue per se. Given such “bystander” effects, cell-free therapeutics manifest as a promising approach in regenerative medicine. Here we aimed at evaluating the effect of conditioned medium (CM) derived from human embryonic MSCs (hESC-MSC) on the neurological deficit, neurogenesis, and angiogenesis in experimental stroke. Adult male Wistar rats subjected to middle cerebral artery occlusion (MCAO), were treated with intracerebroventricular CM either one time (1 h post MCAO) or three times (1, 24, and 48 h post MCAO). Motor performance was assessed by the cylinder test on days 3 and 7. Cerebral samples were obtained for infarct size and molecular analysis on day 7 post-injury. Neurogenesis was evaluated by probing Nestin, Ki67, DCX, and Reelin transcripts and protein levels in the striatum, cortex, subventricular zone, and corpus callosum. The mRNA and protein expression of CD31 were also assessed in the striatum and cortical region to estimate angiogenesis post MCAO. Our findings demonstrate that CM treatment could significantly ameliorate neurological deficits and infarct volume in MCAO rats. Furthermore, ischemic stroke was associated with higher levels of neurogenesis and angiogenesis markers. Following treatment with CM, these markers were further potentiated in the brain regions. This study suggests that the therapeutic benefits of CM obtained from hESC-MSCs at least partly are mediated through improved neurogenesis and angiogenesis to accelerate the recovery of cerebral ischemia insult.

The conditioned medium of human embryonic stem cell-derived mesenchymal stem cells alleviates neurological deficits and improves synaptic recovery in experimental stroke.

The transplantation of mesenchymal stem cells (MSCs) is of main approaches in regenerative therapy for stroke. Due to the potential tumorigenicity and low survival rate of transplanted cells, focuses have been shifted from cell replacement to their paracrine effects. Therefore, stem cell-conditioned medium (CM) therapy has emerged as an alternative candidate. Here, we investigated the effect of CM derived from human embryonic MSCs on experimental ischemic stroke. Wistar rats underwent ischemic stroke by the right middle cerebral artery occlusion (MCAO). CM was infused either one time (1 hr post-MCAO) or three times (1, 24, and 48 hr post-MCAO) through guide cannula into the left lateral ventricle. Neurological functions were evaluated using Bederson's test and modified Neurological Severity Score on Days 1, 3, and 7 following MCAO. Infarction volumes and cerebral edema were measured on Days 3 and 7. growth-associated protein-43, synaptophysin, cAMP response element-binding protein, and phosphorylated-cAMP response element-binding protein levels were also assessed in peri-ischemic cortical tissue on Day 7 postsurgery. Our results indicated that three times injections of CM could significantly reduce body weight loss, mortality rate, infarct volumes, cerebral edema, and improve neurological deficits in MCAO rats. Moreover, three injections of CM could restore decreased levels of synaptic markers in MCAO rats up to its normal levels observed in the sham group. Our data suggest that using the CM obtained from embryonic stem cells-MSCs could be a potent therapeutic approach to attenuate cerebral ischemia insults which may be partly mediated through modulation of synaptic plasticity.

Human embryonic mesenchymal stem cells alleviate pathologic changes of MRL/Lpr mice by regulating Th7 cell differentiation

Recent evidence indicates that mesenchymal stem cells (MSC) derived from early embryonic tissues have better therapeutic ability as compared with adult tissue-derived stem cells. In the present study, we transplanted human early embryonic MSC (hMSC) into MRL/Lpr mice via tail vein injection to observe the therapeutic efficacy of hMSC and their impact on T helper 17 (Th17) cell differentiation in MRL/Lpr mice. Animals in hMSC treatment group received hMSC (1 × 106/200 μL) via the tail vein at the age of 16 and 19 weeks. We found that hMSC treatment prolonged the survival of MRL/Lpr mice without inducing tumorigenesis, reduced urine protein, and alleviated the renal pathologic changes. In addition, it reduced the proportion of Th17 cells in the spleen of MRL/Lpr mice and the serum interleukin 17 (IL-17) concentration. Our in vitro experiment also demonstrated that hMSC could secrete Th17 differentiation-related cytokines of PGE2, IL-10 and TGF-β, and IFN-γ stimulation up-regulated the secretion of these immune regulating factors. The results of the present study suggest that hMSC therapy could alleviate systemic and local renal lesions in MRL/Lpr mice, probably by secreting immune regulating factors and regulating Th17 cell differentiation in MRL/Lpr mice.

Exosomes derived from human embryonic mesenchymal stem cells promote osteochondral regeneration

Clinical and animal studies have demonstrated the efficacy of mesenchymal stem cell (MSC) therapies in cartilage repair. As the efficacy of many MSC-based therapies has been attributed to paracrine secretion, particularly extracellular vesicles/exosomes, we determine here if weekly intra-articular injections of human embryonic MSC-derived exosomes would repair and regenerate osteochondral defects in a rat model. In this study, osteochondral defects were created on the trochlear grooves of both distal femurs in 12 adult rats. In each animal, one defect was treated with 100μg exosomes and the contralateral defect treated with phosphate buffered saline (PBS). Intra-articular injections of exosomes or PBS were administered after surgery and thereafter weekly for a period of 12 weeks. Three unoperated age-matched animals served as native controls. Analyses were performed by histology, immunohistochemistry, and scoring at 6 and 12 weeks after surgery. Generally, exosome-treated defects showed enhanced gross appearance and improved histological scores than the contralateral PBS-treated defects. By 12 weeks, exosome-treated defects displayed complete restoration of cartilage and subchondral bone with characteristic features including a hyaline cartilage with good surface regularity, complete bonding to adjacent cartilage, and extracellular matrix deposition that closely resemble that of age-matched unoperated control. In contrast, there were only fibrous repair tissues found in the contralateral PBS-treated defects. This study demonstrates for the first time the efficacy of human embryonic MSC exosomes in cartilage repair, and the utility of MSC exosomes as a ready-to-use and 'cell-free' therapeutic alternative to cell-based MSC therapy.

Human embryonic mesenchymal stem cells participate in differentiation of renal tubular cells in newborn mice

Stem cells are used with increasing success in the treatment of renal tubular injury. However, whether mesenchymal stem cells (MSC) differentiate into renal tubular epithelial cells remains controversial. The aims of the present study were to observe the localization of human embryonic MSCs (hMSCs) in the kidneys of newborn mice, and to investigate hMSC differentiation into tubular epithelium. Primary culture hMSCs were derived from 4–7-week-old embryos and labeled with the cell membrane fluorescent dye PKH-26. The degree of apoptosis, cell growth, differentiation and localization of hMSCs with and without this label were then determined using immunohistochemical methods and flow cytometry. hMSCs and PKH26-labeled hMSCs were revealed to differentiate into chondrocytes and adipocytes, and were demonstrated to have similar proliferative capability. In the two cell types, the antigens CD34 and CD45, indicative of hematopoietic lineages, were not expressed; however, the expression of the mesenchymal markers CD29 and CD90 in MSCs, was significantly increased. During a 4-week culture period, laser confocal microscopy revealed that PKH26-labeled hMSCs in the kidneys of newborn mice gradually dispersed. Two weeks after the injection of the PKH26-labeled cells, the percentage of PKH26-labeled hMSCs localized to the renal tubules was 10±2.1%. In conclusion, PKH26 labeling has no effect on hMSC differentiation, proliferation and mesenchymal cell surface features, and hMSCs injected into the kidneys of newborn mice may transform to renal tubule epithelium.

Transplantation of Human Embryonic Mesenchymal Stem Cells Alleviates Lupus Nephritis in MRL/lpr Mice

Transplantation of Human Embryonic Mesenchymal Stem Cells Alleviates Lupus Nephritis in MRL/lpr Mice

Expression of Nucleostemin gene in tumor cells derived from human embryomic bone marrow mesenchymal stem cells

Objective To study role of bone marrow mesenehyme stem cells in tumor formation.Methods Nude mice (n = 18) were randomly divided into two groups.Mice in the control group were subcutaneously injected with human embryonic MSCs, and F6 cells were injected into the nine mice of the experimental group.Three mice were sacrificed to remove tumor tissue, which was then prepared for real-time BT-PCR detection at 4 (F6-4), 6 (F6-6) and 7 (F6-7) weeks, respectively.Human lung cancer tissue samples and adjacent non-malignant lung tissue samples were collected from 4 lung cancer patients.The difference between gene expression of F6 cells and MSCs was distinguished by fluorescent differential display (FDD) and verificated by PCR and the western blot analysis. Real-time fluorescent quantitative reverse transcription polymerase chain reaction (FQ-BT-PCR) was used to detect gene expression in tumor tissues after tumorigenesis in nude mice.A new tumor cell line, denominated F6, was established from mutated human embryonic bone marrow mesenchymal stem cells (MSCs) which were induced by the GMCSF and IL-4 in vitro.Results FDD analysis confirmed that cyelin Ⅰ was positively up-regulated in F6 cells compared with MSCs. Similar results were obtained by PCR and western blot.The cyclin Ⅰ gene expression levels in MSCs, F6, F6-4, F6-6 and 176-7 were significantly different(F=12.29 ,P ＜ 0.01).The cyclin Ⅰ gene expression level in F6(4.49±0.40) was 112 folds higher than those of MSCs(0.04±0.02,P＜0.01).Expression levels in F6-4 , F6-6 and F6-7 tissue were 1.82±0.80,3.30±0.43,3.68±1.67 which were significantly higher than that in MSCs (P＜0.05 or ＜0.01).The expression of cyclin Ⅰ increased significantly alone with the accreting volume of tumor.The expression levels of cyelin Ⅰ in human lung cancer tissues in four patients were 0.15±0.02, 0.58±0.23, 4.82±1.12, 1.21±0.60,respectively, and were significantly higher than that in adjacent non-malignant lung tissues (0.04±0.02,0.09±0.04,0.94±0.74,0.15±0.08) (F=12.39,P＜0.01).The protein expression level of cyclin Ⅰ in F6 cells was 0.32±0.08, which was 3.6-fold higher than that in MSCs (0.09±0.06, t=3.86,P＜0.05).Conclusions The expression level of cyclin Ⅰ in tumor tissue is higher during the entire course of tumorigenesis.Cyclin Ⅰ might be one of the factors playing important roles during tumorigenesis,especially in MSCs mutation. Key words: Neoplasms; Mesenchymal stem cells; Cyclins

Differentiation potential of human embryonic mesenchymal stem cells for skin-related tissue

Mesenchymal stem cells (MSC) have the capacity to differentiate into cells of connective tissue lineages, including bone, fat, cartilage and muscle, but the differentiation of embryonic MSC into epidermal cells by mesenchymal-epithelial transition has not been confirmed. To determine the biological characteristics of human embryonic MSC (hMSC) and their potential for differentiation into epithelial cells. hMSC were derived from 4-7-week-old embryos; they were localized and isolated, then primary culture was done. The biological characteristics of hMSC were detected by immunohistochemical methods and flow cytometry. Their differentiation potential was determined by coculture with conditioning medium and in vivo injection. hMSC express the relative specific antigens of MSC, such as SH2, alpha-smooth actin, CD29, CD44, CD90 and S100. After stimulation and in vivo transplantation, hMSC possess the potential to differentiate into epidermal cells with the production of keratin 19 and E-cadherin. hMSC derived from the early human embryo have the ability to transform into epidermal cells in vivo and in vitro.