Subconjunctival injection of human umbilical cord mesenchymal stem cells alleviates experimental allergic conjunctivitis via regulating T cell response.

BACKGROUND: T helper 2 (Th2) cells are thought to play critical roles in allergic conjunctivitis (AC). They release inflammatory cytokines to promote an allergic response in AC. Due to individual heterogeneity and long-term chronic management, current therapies do not always effectively control AC. Mesenchymal stem cells (MSCs) have been shown to be effective in treating allergy-related disorders, but it is unclear how exactly the Th2-mediated allergic response is attenuated. This study aims to elucidate the therapeutic effect and mechanism of the human umbilical cord MSCs (hUCMSCs) in a mouse model of experimental AC (EAC). METHODS: A mouse EAC model was established by inoculating short ragweed (SRW) pollen. After the SRW pollen challenge, the mice received a single subconjunctival or tail vein injection of 2 × 106 hUCMSCs, or subconjunctival injection of hUCMSCs conditioned medium (hUCMSC-CM), and dexamethasone eye drops was used as positive control; subsequent scratching behavior and clinical symptoms were assessed. Immunostaining and flow cytometry were carried out to show allergic reactions and the activation of CD4 + T cell subsets in the conjunctiva and cervical lymph nodes (CLNs). Gene expression was determined by RNA-seq and further verified by qRT-PCR and Western blot. Co-culture assays were performed to explore the regulatory role of hUCMSCs in the differentiation of CD4 + naive T cells (Th0) into Th2 cells. RESULTS: Subconjunctival administration of hUCMSCs resulted in fewer instances of scratching and lower inflammation scores in EAC mice compared to the tail vein delivery, hUCMSC-CM and control groups. Subconjunctival administration of hUCMSCs reduced the number of activated mast cells and infiltrated eosinophils in the conjunctiva, as well as decreased the number of Th2 cells in CLNs. After pretreatment with EAC mouse serum in vitro to mimic the in vivo milieu, hUCMSCs were able to inhibit the differentiation of Th0 into Th2 cells. Further evidence demonstrated that repression of Th2 cell differentiation by hUCMSCs is mediated by CRISPLD2 through downregulation of STAT6 phosphorylation. Additionally, hUMCSCs were able to promote the differentiation of Th0 cells into regulatory T cells in CLNs of EAC mice. CONCLUSIONS: Subconjunctival injection of hUCMSCs suppressed the Th2-allergic response and alleviated clinical symptoms. This study provides not only a potential therapeutic target for the treatment of AC but also other T cell-mediated diseases.

Bilayer Silk Fibroin/Sodium Alginate Scaffold Delivered hUC-MSCs to Enhance Skin Scarless Healing and Hair Follicle Regeneration with the IRE1/XBP1 Pathway Inhibition.

Efficient local delivery of mesenchymal stem cells (MSCs) is a decisive factor for their application in regeneration processes. Here, we prepared a biomimetic bilayer silk fibroin/sodium alginate (SF/SA) scaffold to deliver human umbilical mesenchymal stem cells (hUC-MSCs) for wound healing. An SA membrane was prepared by the casting method on the upper layer of the scaffold to simulate the dense epidermal structure. On the lower layer, porous materials simulating the loose structure of the dermis were formed by the freeze-drying method. In vitro, the scaffold was proven to have a high-density pore structure, good swelling property, and suitable degradation rate. The hUC-MSCs could survive on the scaffold for up to 14 days and maintain cell stemness for at least 7 days. In vivo, SF/SA scaffolds loaded with hUC-MSCs (M-SF/SA) were applied to full-thickness defect wounds and compared with the local injection of hUC-MSCs. The M-SF/SA group showed excellent therapeutic efficacy, characterized by induction of macrophage polarization, regulation of TGF-ß expression and collagen components, and enhancement of vascular regeneration, thereby preventing scar formation and promoting hair follicle regeneration. Furthermore, the expression of endoplasmic reticulum stress markers IRE1, XBP1, and CHOP was inhibited significantly in M-SF/SA treatment. In conclusion, the bilayer SF/SA scaffold is an ideal delivery platform for hUC-MSCs, and the M-SF/SA system could locally promote scarless skin healing and hair follicle regeneration by alleviating the IRE1/XBP1 signal pathway.

Stanniocalcin-1 secreted by human umbilical mesenchymal stem cells regulates interleukin-10 expression via the PI3K/AKT/mTOR pathway in alveolar macrophages.

Acute respiratory distress syndrome (ARDS) is a syndrome of acute respiratory failure caused by infection, trauma, shock, aspiration or drug reaction. The pathogenesis of ARDS is characterized as an unregulated inflammatory storm, which causes endothelial and epithelial layer damage, leading to alveolar fluid accumulation and pulmonary edema. Previous studies have shown the potential role of mesenchymal stem cells (MSC) in combating the inflammatory cascade by increasing the anti-inflammatory mediator interleukin-10 (IL-10). However, the involved mechanisms are unclear. Here we investigated whether a key immunomodulatory regulator, stanniocalcin-1 (STC-1), was secreted by MSC to activate phosphoinositide 3-kinase/protein kinase B (PI3K/AKT)/ mammalian target of rapamycin (mTOR) signaling pathway to increase IL-10 expression in alveolar macrophages. Lipopolysaccharide (LPS)-stimulated alveolar macrophages co-cultured with human umbilical mesenchymal stem cells (HUMSC) secreted high levels of IL-10. HUMSC co-cultured with alveolar macrophages expressed high STC-1 levels and increased PI3K, AKT and mTOR phosphorylation after LPS activation in alveolar macrophages. STC-1 knockdown in HUMSC decreased the phosphorylation of PI3K, AKT and mTOR and suppressed IL-10 expression in alveolar macrophages. Rapamycin (an mTOR inhibitor) reduced IL-10 secretion in alveolar macrophages. These results, together with our previous study and others, indicate that the PI3K/AKT/mTOR pathway is involved in the regulation of IL-10 production by STC-1 secreted by HUMSC in alveolar macrophages.

Revealing the mechanisms of Weishi Huogu I capsules used for treating osteonecrosis of the femoral head based on systems pharmacology with one mechanism validated with in vitro experiments.

ETHNOPHARMACOLOGICAL RELEVANCE: Weishi Huogu I (WH I) capsules, developed through traditional Chinese medicine, have been used to treat clinical osteonecrosis of the femoral head (ONFH) for decades. However, the mechanisms have not been systematically studied. AIM OF THE STUDY: In this study, the mechanisms of WH I capsules used in treating ONFH were examined through a systems pharmacology strategy, and one mechanism was validated with in vitro experiments. MATERIALS AND METHODS: WH I capsules compounds were identified by screening databases; then, a database of the potential active compounds was constructed after absorption, distribution, metabolism and excretion (ADME) evaluation. The compounds were identified through a systematic approach in which the probability of an interaction of every candidate compound with each corresponding target in the DrugBank database was calculated. Gene Ontology (GO) and pathway enrichment analyses of the targets was performed with the Metascape and KEGG DISEASE databases. Then, a compound-target network (C-T) and target-pathway network (T-P) of WH I capsule components were constructed, and network characteristics and related information were used for systematically identifying WH I capsule multicomponent-target interactions. Furthermore, the effects of WH I capsule compounds identified through the systematic pharmacology analysis of the osteogenic transformation of human umbilical mesenchymal stem cells (HUMSCs) were validated in vitro. RESULTS: In total, 152 potentially important compounds and 176 associated targets were identified. Twenty-two crucial GO biological process (BP) or pathways were related to ONFH, mainly in regulatory modules regulating blood circulation, modulating growth, and affecting pathological processes closely related to ONFH. Furthermore, the GO enrichment analysis showed that corydine, isorhamnetin, and bicuculline were enriched in "RUNX2 regulates osteoblast differentiation", significantly increased alkaline phosphatase activity and calcium deposition and upregulated runt-related transcription factor 2 mRNA and protein expression and osteocalcin mRNA expression in HUMSCs, suggesting that these compounds promoted the mesenchymal stem cell (MSC) osteogenic transformation. CONCLUSIONS: The study showed that the pharmacological mechanisms of WH I capsule attenuation of ONFH mainly involve three therapeutic modules: blood circulation, modulating growth, and regulating pathological processes. The crosstalk between GOBPs/pathways may constitute the basis of the synergistic effects of the compounds in WH I capsules in attenuating ONFH. One of the pharmacological mechanisms in the WH I capsule effect on ONFH involves enhancement of the osteogenic transformation of MSCs, as validated in experiments performed in vitro; however, more mechanisms should be validated in further studies.

Comparison of reversal of rat pulmonary fibrosis of nintedanib, pirfenidone, and human umbilical mesenchymal stem cells from Wharton's jelly.

BACKGROUND: The present study compared the effects of antifibrotic medications, pirfenidone, and nintedanib, with transplantation of human umbilical mesenchymal stem cells (HUMSCs) in restoring rat pulmonary fibrosis (PF). METHODS: A stable animal model was established via an intratracheal injection of 5 mg bleomycin (BLM). One single transplantation of 2.5× 107 HUMSCs or initiation of daily oral nintedanib/pirfenidone administration was performed on day 21 following BLM damage. RESULTS: Pulmonary function examination revealed that BLM rats exhibited a significant decrease in blood oxygen saturation and an increase in respiratory rates. While no significant improvements were found in BLM rats receiving nintedanib or pirfenidone, those who transplanted with HUMSCs showed a statistical amelioration in blood oxygen saturation and significant alleviation in respiratory rates. Quantification results revealed that a significant reduction in alveolar space and marked increases in substantial cell infiltration and collagen deposition in the left lungs of BLM rats. No significant alteration was observed in BLM rats administered nintedanib or pirfenidone. However, BLM rats transplanted with HUMSCs had a significant recovery in alveolar space and noticeable decreases in cell infiltration and collagen deposition. The inflammatory cell numbers in the bronchoalveolar lavage was increased in the BLM group. While the rats treated with nintedanib or pirfenidone had a lower cell number than the BLM group, a higher cell number was found as compared with the Normal group. In rats transplanted with HUMSCs, the cell number did not differ from the Normal group. CONCLUSIONS: Transplantation of HUMSCs could effectively treat PF as opposed to the administration of anti-fibrotic drugs with nintedanib or pirfenidone with a significant better result in lung volume, pathological changes, lung function, and blood oxygen saturation.

Exosomal microRNA-139-5p from mesenchymal stem cells accelerates trophoblast cell invasion and migration by motivation of the ERK/MMP-2 pathway via downregulation of protein tyrosine phosphatase.

AIM: Exosomes present essential roles for intercellular interaction via extracellular pathways during systemic dysfunctions, including preeclampsia (PE). Here, we assessed the specific mechanism of mesenchymal stem cells (MSC)-originated exosomes in PE. METHODS: The effects of exosomes on trophoblasts were studied by EdU, wound healing, Transwell and TUNEL assays. By microarray analysis, we found that exosomes enhanced the microRNA-139-5p (miR-139-5p) in trophoblasts, and confirmed the target gene of miR-139-5p by bioinformatics prediction and dual-luciferase reporter gene assay. At the same time, ERK/MMP-2 pathway-related biomolecules were assessed through Western blot analysis. The pathway inhibitor was used for rescue experiments. Finally, the effect of exosomes on the pathology of PE rats was verified by in vivo experiments. RESULTS: The exosomes originated from hucMSC fostered the trophoblast cell migration, invasion and proliferation and obstructed apoptosis. Moreover, miR-139-5p could be transmitted to trophoblasts through hucMSC-secreted exosomes. miR-139-5p targeted protein tyrosine phosphatase (PTEN), which regulated the ERK/MMP-2 pathway. Inhibition of the ERK/MMP-2 pathway significantly reduced the promoting effect of exosomes on trophoblasts. Treatment with exosomes significantly lowered blood pressure values and reduced 24-h proteinuria in PE rats. CONCLUSION: hucMSC-originated exosomes overexpressing miR-139-5p activated the ERK/MMP-2 pathway via PTEN downregulation, thus accelerating trophoblast cell invasion and migration, and blocking apoptosis. These results demonstrated that hucMSC-derived exosomes overexpressing miR-139-5p might be an innovative direction for therapeutic approaches against PE.

VX-765 enhances autophagy of human umbilical cord mesenchymal stem cells against stroke-induced apoptosis and inflammatory responses via AMPK/mTOR signaling pathway.

INTRODUCTION: To investigate the protective effect of VX-765 on human umbilical mesenchymal stem cells (HUMSCs) in stroke and its mechanism. MATERIALS AND METHODS: Mouse models of ischemic stroke were established using the distal middle cerebral artery occlusion (dMCAO) method. The dMCAO mice were accordingly transplanted with HUMSCs, VX-765-treated HUMSCs, or VX-765 + MHY185-treated HUMSCs. The HUMSCs were inserted with green fluorescent protein (GFP) for measurement of transplantation efficiency which was determined by immunofluorescence assay. Oxygen-glucose deprivation (OGD) was applied to mimic ischemic environment in vitro experiments, and the HUMSCs herein were transfected with AMPK inhibitor Compound C or autophagy inhibitor 3-MA. MTT assay was used to test the toxicity of VX-765. TUNEL staining and ELISA were applied to measure the levels of apoptosis and inflammatory cytokines (IL-1ß, IL-6, and IL-10), respectively. The expressions of autophagy-associated proteins, AMPK, and mTOR were detected by Western blotting. TTC staining was applied to reveal the infarct lesions in the brain of dMCAO mice. RESULTS: The pro-inflammatory cytokines, TUNEL-positive cells, and p-mTOR were decreased while the anti-inflammatory cytokine, autophagy-related proteins, and p-AMPK were increased in HUMSCs treated with VX-765 under OGD condition. Different expression patterns were found with the above factors after transfection of 3-MA or Compound C. The pro-inflammatory cytokines, TUNEL-positive cells, and infarct sections were decreased while the anti-inflammatory cytokine and autophagy-related proteins were increased in dMCAO mice transplanted with VX-765-treated HUMSCs compared to those transplanted with HUMSCs only. The autophagy was inhibited while p-mTOR was up-regulated after transfection of MHY. CONCLUSION: VX-765 protects HUMSCs against stroke-induced apoptosis and inflammatory responses by activating autophagy via the AMPK/mTOR signaling pathway in vivo and in vitro.

Human Umbilical Mesenchymal Stem Cells Display Therapeutic Potential in Rheumatoid Arthritis by Regulating Interactions Between Immunity and Gut Microbiota via the Aryl Hydrocarbon Receptor.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disease that may be associated with gut microbiota via the aryl hydrocarbon receptor (AhR). Human umbilical mesenchymal stem cells (HUMSCs) have therapeutic potential against RA, but the underlying mechanism has not been fully elucidated. The purpose of this study was to explore the mechanism of action of HUMSCs in rats with collagen-induced arthritis (CIA). METHOD: HUMSCs (1 × 106) were transplanted into each rat with CIA. The tissue localization of HUMSCs and the therapeutic effects in the ankles were assessed. The immune status and expression of immune-related genes and proteins in related lymphoid tissues were subsequently tested. Furthermore, the levels of immune-related factors in serum and the changes in gut microbiota in the ileum were detected, and the levels of indole and their derivatives in plasma and the levels of AhR in the ileum were evaluated. RESULTS: HUMSCs homed to the popliteal lymph node (PLN), mesenteric lymph node (MLN), ankle cartilage, and ileum mucosa in rats with CIA. The transplantation of HUMSCs reduced the pathology scores and the degree of bone damage in the ankles. The immune status of T regulatory cells (Tregs) and T helper (Th)17 cells and the gene expression levels of interleukin (IL)-10, transforming growth factor (TGF)-ß1, and IL-17A were altered in the PLN, which is the lymph tissue closest to the nidus, and the MLN, which is one of the gut-associated lymphoid tissues (GALTs). The proportion and function of B cells, Tregs, and Th17 cells were regulated in other GALTs, namely, Peyer's patches and the lamina propria. The gene expression of TGF-ß1 and IL-17A and protein expression of IL-10, TGF-ß1, IL-17A, IL-22, and immunoglobulin A (IgA) were modulated in the ileum, and the serum levels of IL-10, TGF-ß1, IL-17A, IL-1ß, and tumor necrosis factor (TNF)-α were regulated in the rats with CIA. The relative abundances of the genera Bacteroides and Bacillus were increased in the HUMSCs-treated rat with CIA; in addition, the levels of indole, indoleacetic acid, and indole-3-lactic acid were consistently upregulated, and this upregulation was accompanied by increases in AhR gene and protein expression. CONCLUSION: Our study demonstrates that HUMSCs play a therapeutic role in rats with CIA by regulating the interactions between host immunity and gut microbiota via the AhR.

Inhibitory effect of exosomes secreted by human umbilical cord mesenchymal stem cells on apoptosis of oxygen-glucose deprived reoxygenation model of venous endothelial cells / 中华行为医学与脑科学杂志

Objective@#To explore the inhibitory effect of exosomes secreted by human umbilical cord mesenchymal stem cells(HUCMSC) on apoptosis of human umbilical vein endothelial cells(HUVEC) after model group(oxygen-glucose deprivation reoxygenation), and to clarify its possible mechanism.@*Methods@#Human umbilical cord mesenchymal stem cells were cultured. The collected cell supernatant was stored in a centrifugal tube. The exosomes secreted by human umbilical cord mesenchymal stem cells were extracted by ultracentrifugation and identified. Human umbilical vein endothelial cells were randomly divided into control group, model group and different concentrations of HUCMSC-EXO(20 μg/ml, 40 μg/ml, 60 μg/ml) treatment groups(adding HUCMSC-EXO into the model group) . The morphological changes of HUVEC cells in each group were observed by inverted phase contrast microscope, and the proliferation inhibition rate of HUVEC in each group was measured by CCK-8 reagent. Western blot was used to detect the expression of apoptosis-related proteins Caspase-3, Bax, Bcl-2 and hypoxia-associated protein hypoxia inducible factor 1α(HIF-1α). Inhibitor(HIF-1α inhibitor) + model group and HUCMSC-EXO + inhibitor + model group were added on the basis of the above experiments. Western blot analysis was performed to observe the effects of HUCMSC-EXO, inhibitor and both of them on HIF-1α and Bax expressions in HUVEC.@*Results@#HUCMSC-EXO was successfully extracted and identified. Compared with the control group, the volume of HUVEC in the model group and the HUCMSC-EXO group with different concentrations decreased, became round, connected and evacuated, and the growth state was poor under the inverted phase contrast microscope.CCK-8 detection showed that the cell viability in the HUCMSC-EXO group was significantly higher than that in the model group, the difference was statistically significant (t=9.23, P<0.05). Western blot analysis showed that compared with the control group, the expression levels of Caspase-3 ((0.296±0.038), (0.879±0.088); t=14.92, P<0.05), Bax((0.234±0.034), (0.762±0.084); t=14.36, P<0.05) of HUVEC in the model group were up-regulated, and the expression level of Bcl-2 was down-regulated ((0.863±0.103), (0.387±0.059); t=9.85, P<0.05), with statistically significant differences. Compared with the model group, the expression levels of Caspase-3( (0.586±0.075); t=6.24, P<0.05), Bax((0.311±0.055); t=11.01, P<0.05) and Bcl-2((0.665±0.071); t=7.45, P<0.05) of HUVEC in the HUCMSC-EXO treatment group were down-regulated and the differences were statistically significant. Inhibitor intervention experiments showed that there were no significant differences between the inhibitor+ model group and HUCMSC-EXO+ inhibitor+ model group in the expression of HIF-1α protein ((0.348±0.055), (0.388±0.077); t=1.04, P>0.05)and Bax protein ((0.363±0.069), (0.370±0.064); t=0.18, P>0.05). But both of them were down-regulated compared with the model group (HIF-1α protein (0.919±0.064), Bax protein (0.902±0.071)), the differences were significant( t=13.56, t=13.03, both P<0.05).@*Conclusion@#HUCMSC-EXO has a protective effect on OGD/R model of HUVEC, and its mechanism may be related to the down-regulation of HIF-1α expression.

Human umbilical mesenchymal stem cell-derived exosome attenuates car-diac fibrosis in diabetic mice / 中国病理生理杂志

AIM:To explore the protective effects of exosome secreted by human umbilical mesenchymal stem cells on cardiac fibrosis in diabetic mouse model.METHODS:Male C57BL/6 mice at 6～8 weeks of age were divided in-to 3 groups randomly:control group ,diabetes mellitus(DM)group and DM+exosome group.To develop mouse DM mo-del,the mice were fed with high-fat diet for 5 weeks,followed by intraperitoneal injection of 45 mg/kg streptozocin once a week for 5 weeks.It was considered as a successful DM model that the blood glucose of the mice was ≥16.7 mmol/L.The mice in DM+exosome group were injected with exosome via tail vein.The mice in other 2 groups were injected with saline at the same volume.The heart function was evaluated by color Doppler echocardiography for small animals.The blood sam-ples were collected from abdominal aortas.The blood glucose and non-esterified fatty acids were measured by biochemical colorimetric assay.HE staining was performed to observe the structural changes of myocardial fibers ,and Masson staining was used to observe the cardiac fibrosis.RESULTS:The results of echocardiography showed that left ventricular end-dias-tolic dimension(LVIDd)and left ventricular end-systolic dimension(LVIDs)of diabetic mice were larger than those incontrol mice(P<0.05 and P<0.01,respectively).The ejection fraction(EF)and fractional shortening(FS)decreased in the diabetic mice(P<0.01).Exosome treatment significant decreased the LVIDs(P<0.01),but increased the EF and FS(P<0.01).The blood glucose and non-esterified fatty acids were significantly increased in the diabetic mice.The injection of the stem cell exosome significantly decreased the blood glucose and non -esterified fatty acids(P<0.01).HE staining observation showed that cardiomyocyte hypertrophy and fragmentation of cardiomyocyte in DM group were more se -rious than those in control group.Masson staining showed that the area of fibrosis in DM group was larger than that in con-trol group(P<0.01),but that in DM+exosome group was reduced(P<0.01).CONCLUSION:Exosome secreted by human umbilical mesenchymal stem cells protects the DM model mice from cardiac fibrosis.

Transendothelial migration of human umbilical mesenchymal stem cells across uterine endothelial monolayers: Junctional dynamics and putative mechanisms.

INTRODUCTION: During pregnancy, fetal stem cells can transfer to the maternal circulation and participate in tissue repair. How they transmigrate across maternal endothelial barriers and whether they can subsequently influence maternal endothelial integrity is not known. METHODS: Mesenchymal stem cells (WJ-MSC) were isolated from Wharton's jelly and their interactions with human uterine microvascular endothelial cell (HUtMEC) monolayers, junctional occupancy and expression/phosphorylation of vascular endothelial (VE)- cadherin and vascular endothelial growth factor (VEGF-A) secretion was studied over 48h by real time, confocal microscopy, immunoblotting and ELISA. RESULTS: WJ-MSC displayed exploratory behaviour with interrogation of paracellular openings and spreading into the resultant increased gaps followed by closing of the endothelium over the WJ-MSC. 62% of added cells crossed within 22h to sub-endothelial niches. There was a concomitant loss of junctional VE-cadherin in HUtMEC followed by a full return and increased VE-cadherin expression after 22h. During early hours, VE-cadherin showed a transient phosphorylation at Tyrosine (Tyr)-685 when VEGF-A secretion were high. From 16 to 22h, there was increased de-phosphorylation of Tyr-731. Anti-VEGF-A blocked Tyr-685 phosphorylation but not the decrease in P-Tyr731; this partially inhibited WJ-MSC transmigration. DISCUSSION: Fetal WJ-MSC can traverse uterine endothelial monolayers by mediating a non-destructive paracellular pathway. They can promote junctional stability of uterine endothelium from the sub-endothelial niche. Mechanistically, WJ-MSC induces VEGF-dependent phosphorylation events linked with paracellular permeability and VEGF-independent de-phosphorylation events associated with leukocyte extravasation. Our data also allows consideration of a possible role of fetal MSC in mature functioning of the uterine vasculature needed for optimal utero-placental perfusion.

Human umbilical mesenchymal stem cells conditioned medium promote primary wound healing regeneration.

AIM: This research was conducted to clarify the capability of human umbilical mesenchymal stem cells conditioned medium (HU-MSCM) to promote regenerations of primary wound healing on the incision skin injury. MATERIALS AND METHODS: In this study, two approaches in vitro and in vivo already done. On in vitro analysis, tube formation was performed using HU vein endothelial cells in the presence of HU-MSCM, in some experiments cells line was incubated prior the presence of lipopolysaccharide and HU-MSCM then apoptosis assay was performed. Furthermore, in vivo experiments 12 female rats (Rattus norvegicus) were used after rats anesthetized, 7 mm wound was made by incision on the left side of the body. The wound was treated with HU-MSCM containing cream, povidone iodine was run as a control. Wound healing regenerations on the skin samples were visualized by hematoxylin-eosin staining. RESULTS: In vitro models elucidate HU-MSCM may decreasing inflammation at the beginning of wound healing, promote cell migration and angiogenesis. In addition in vivo models show that the incision length on the skin is decreasing and more smaller, HE staining describe decreasing of inflammation phase, increasing of angiogenesis, accelerate fibroplasia, and maturation phase. CONCLUSIONS: Taken together our observation indicates that HU-MSCM could promote the acceleration of skin tissue regenerations in primary wound healing process.

Xenograft of human umbilical mesenchymal stem cells from Wharton's jelly as a potential therapy for rat pilocarpine-induced epilepsy.

We evaluated the effects of intra-hippocampal transplantation of human umbilical mesenchymal stem cells (HUMSCs) on pilocarpine-treated rats. Sprague-Dawley rats were divided into the following three groups: (1) a normal group of rats receiving only PBS, (2) a status epilepticus (SE) group of rats with pilocarpine-induced SE and PBS injected into the hippocampi, and (3) a SE+HUMSC group of SE rats with HUMSC transplantation. Spontaneous recurrent motor seizures (SRMS) were monitored using simultaneous video and electroencephalographic recordings at two to four weeks after SE induction. The results showed that the number of SRMS within two to four weeks after SE was significantly decreased in SE+HUMSCs rats compared with SE rats. All of the rats were sacrificed on Day 29 after SE. Hippocampal morphology and volume were evaluated using Nissl staining and magnetic resonance imaging. The results showed that the volume of the dorsal hippocampus was smaller in SE rats compared with normal and SE+HUMSCs rats. The pyramidal neuron loss in CA1 and CA3 regions was more severe in the SE rats than in normal and SE+HUMSCs rats. No significant differences were found in the hippocampal neuronal loss or in the number of dentate GABAergic neurons between normal and SE+HUMSCs rats. Compared with the SE rats, the SE+HUMSCs rats exhibited a suppression of astrocyte activity and aberrant mossy fiber sprouting. Implanted HUMSCs survived in the hippocampus and released cytokines, including FGF-6, amphiregulin, glucocorticoid-induced tumor necrosis factors receptor (GITR), MIP-3ß, and osteoprotegerin. In an in vitro study, exposure of cortical neurons to glutamate showed a significant decrease in cell viability, which was preventable by co-culturing with HUMSCs. Above all, the expression of human osteoprotegerin and amphiregulin were significantly increased in the media of the co-culture of neurons and HUMSCs. Our results demonstrate the therapeutic benefits of HUMSC transplantation for the development of epilepsy, which are likely due to the ability of the cells to produce neuroprotective and anti-inflammatory cytokines. Thus, HUMSC transplantation may be an effective therapy in the future.

A comparative study on the transplantation of different concentrations of human umbilical mesenchymal cells into diabetic rats.

AIM: To observe the effects of intravitreal injections of different concentrations of human umbilical mesenchymal stem cells on retinopathy in rats with diabetes mellitus. METHODS: Healthy and adult male Sprague-Dawley (SD) rats were randomly assigned to a normal control group (group A), a diabetic retinopathy (DR) blank control group (group B), a high-concentration transplantation group (group C), a low-concentration transplantation group (group D) and a placebo transplantation group (group E). The expression of nerve growth factor (NGF) protein in the retinal layers was detected by immunohistochemical staining at 2, 4, 6 and 8wk. RESULTS: The expression of NGF was positive in group A and most positive in the retinal ganglion cell layer. In groups B and E, the expression of NGF was positive 2wk after transplantation and showed an increase in all layers. However, the level of expression had decreased in all layers at 4wk and was significantly reduced at 8wk. In groups C and D, the expression of NGF had increased at 2wk and continued to increase up to 8wk. The level of expression in group C was much higher than that in group D. CONCLUSION: DR can be improved by intravitreal injection of human umbilical mesenchymal stem cells. High concentrations of human umbilical mesenchymal stem cells confer a better protective effect on DR than low concentrations.

Enhanced angiogenesis promoted by human umbilical mesenchymal stem cell transplantation in stroked mouse is Notch1 signaling associated.

Cellular therapy has provided hope for restoring neurological function post stroke through promoting endogenous neurogenesis, angiogenesis and synaptogenesis. The current study was based on the observation that transplantation of human umbilical cord mesenchymal stem cells (hUCMSCs) promoted the neurological function improvement in stroked mice and meanwhile enhanced angiogenesis in the stroked hemisphere. Grafted hUCMSCs secreted human vascular endothelial growth factor A (VEGF-A). Notch1 signaling was activated after stroke and also in the grafted hUCMSCs. To address the potential mechanism that might mediate such pro-angiogenic effect, we established a hUCMSC-neuron co-culture system. Neurons were subjected to oxygen glucose deprivation (OGD) injury before co-culturing to mimic the in vivo cell transplantation. Consistent with the in vivo data, co-culture medium claimed from hUCMSC-OGD neuron co-culture system significantly promoted the capillary-like tube formation of brain-derived endothelial cells. Moreover, coincident with our in vivo data, Notch 1 signaling activation was detected in hUCMSCs after co-cultured with OGD neurons as demonstrated by the up-regulation of key Notch1 signaling components Notch1 and Notch1 intercellular domain (NICD). In addition, OGD-neuron co-culture also increased the VEGF-A production by hUCMSCs. To verify whether Notch1 activation was involved in the pro-angiogenic effect, γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) was added into the co-culture medium before co-culture. It turned out that DAPT significantly prevented the Notch1 activation in hUCMSCs after co-culture with OGD neurons. More importantly, the pro-angiogenic effect of hUCMSCs was remarkably abolished by DAPT addition as demonstrated by inhibited capillary-like tube formation and less VEGF-A production. Regarding how Notch1 signaling was linked with VEGF-A secretion, we provided some clue that Notch1 effector Hes1 mRNA expression was significantly up-regulated by OGD-neuron co-culturing and down-regulated after additional treatment of DAPT. In summary, our data provided evidence that the VEGF-A secretion from hUCMSCs after being triggered by OGD neurons is Notch1 signaling associated. This might be a possible mechanism that contributes to the angiogenic effect of hUCMSC transplantation in stroked brain.

Human umbilical cord Wharton's jelly-derived oligodendrocyte precursor-like cells for axon and myelin sheath regeneration.

Human umbilical mesenchymal stem cells from Wharton's jelly of the umbilical cord were induced to differentiate into oligodendrocyte precursor-like cells in vitro. Oligodendrocyte precursor cells were transplanted into contused rat spinal cords. Immunofluorescence double staining indicated that transplanted cells survived in injured spinal cord, and differentiated into mature and immature oligodendrocyte precursor cells. Biotinylated dextran amine tracing results showed that cell transplantation promoted a higher density of the corticospinal tract in the central and caudal parts of the injured spinal cord. Luxol fast blue and toluidine blue staining showed that the volume of residual myelin was significantly increased at 1 and 2 mm rostral and caudal to the lesion epicenter after cell transplantation. Furthermore, immunofluorescence staining verified that the newly regenerated myelin sheath was derived from the central nervous system. Basso, Beattie and Bresnahan testing showed an evident behavioral recovery. These results suggest that human umbilical mesenchymal stem cell-derived oligodendrocyte precursor cells promote the regeneration of spinal axons and myelin sheaths.