Umbilical Cord Blood-derived Mesenchymal Stem Cells Research Articles

TGF-β secreted by human umbilical cord blood-derived mesenchymal stem cells ameliorates atopic dermatitis by inhibiting secretion of TNF-α and IgE.

Human mesenchymal stem cells (MSCs) are promising therapeutics for autoimmune diseases due to their immunomodulatory effects. In particular, human umbilical cord blood-derived MSCs (hUCB-MSCs) have a prominent therapeutic effect on atopic dermatitis (AD). However, the underlying mechanism is unclear. This study investigated the role of transforming growth factor-beta (TGF-β) in the therapeutic effect of hUCB-MSCs on AD. Small interfering RNA (siRNA)-mediated depletion of TGF-β disrupted the therapeutic effect of hUCB-MSCs in a mouse model of AD by attenuating the beneficial changes in histopathology, mast cell infiltration, tumor necrosis factor-alpha (TNF-α) expression, and the serum IgE level. To confirm that hUCB-MSCs regulate secretion of TNF-α, we investigated whether they inhibit TNF-α secretion by activated LAD2 cells. Coculture with hUCB-MSCs significantly inhibited secretion of TNF-α by LAD2 cells. However, this effect was abolished by siRNA-mediated depletion of TGF-β in hUCB-MSCs. TNF-α expression in activated LAD2 cells was regulated by the extracellular signal-related kinase signaling pathway and was suppressed by TGF-β secreted from hUCB-MSCs. In addition, TGF-β secreted by hUCB-MSCs inhibited maturation of B cells. Taken together, our findings suggest that TGF-β plays a key role in the therapeutic effect of hUCB-MSCs on AD by regulating TNF-α in mast cells and maturation of B cells.

Therapeutic Effects of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Combined with Cartilage Acellular Matrix Mediated Via Bone Morphogenic Protein 6 in a Rabbit Model of Articular Cruciate Ligament Transection.

Osteoarthritis (OA) is a general joint disease. Cartilage damage is associated with a decrease in the density of chondrocytes. Mesenchymal stem cells (MSCs) differentiate into adipocytes, osteocytes and chondrocytes, and are an excellent source of cell therapy. Cartilage-derived extracellular matrix (ECM) promotes chondrogenesis of MSCs. However, the role of MSCs stimulated by ECM is not well known in OA. The purpose of this study is to determine the role of specific factors generated by the application of ECM and umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) in managing OA symptoms. Cartilage acellular matrix (CAM), which is a cartilage-derived ECM, was used to promote the chondrogenesis of UCB-MSCs. Induced MSCs were analyzed using chondrogenic markers (aggrecan, collagen type 2, and SOX9) and bone morphogenic protein 6 (BMP6). BMP6 is known to be involved in early chondrogenesis of MSCs. As a result, treatment with CAM significantly increased the expression of chondrogenic markers and BMP6 in UCB-MSCs. Treatment with recombinant human BMP6 also dramatically increased the levels of chondrogenic markers in UCB-MSCs. In addition, UCB-MSCs and CAM were used to evaluate OA symptom improvement in a rabbit articular cruciate ligament transection (ACLT) model. Application of UCB-MSCs and CAM enhanced not only the structure and synthesis of proteoglycan and collagen type 2 but also anti-inflammatory effects in both rabbit joint and synovial fluid. Moreover, the detection of human cells and involvement of BMP6 were confirmed in rabbit cartilage tissues. This study indicates that therapeutic potential of UCB-MSCs with CAM is mediated via BMP6 in OA.

Soluble PTX3 of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Attenuates Hyperoxic Lung Injury by Activating Macrophage Polarization in Neonatal Rat Model.

Therapeutic treatment of various inflammation-related diseases using mesenchymal stem cells (MSCs) has increased in recent years because of the paracrine action of these cells but shows several limitations. First, MSC-based therapies exhibit varying efficacies; thus, biomarkers should be determined to identify who may benefit from these candidate therapeutic agents. Second, the mechanism underlying the therapeutic effects is poorly understood. To evaluate the effects of human umbilical cord blood-derived MSCs (UCB-MSCs) on macrophages, the macrophage cell line NR8383 stimulated with lipopolysaccharide (LPS) was cocultured by UCB-MSCs. We found that UCB-MSCs mediated changes in macrophage polarization towards M2 from M1 macrophages. To identify the paracrine action underlying the anti-inflammation effect of UCB-MSCs, the secretion of UCB-MSCs exposed to LPS-stimulated NR8383 cells was tested using a biotin label-based 507 antibody array. Among the secreted proteins, we selected pentraxin-related protein PTX3/tumor necrosis factor-inducible gene 14 protein (PTX3) to investigate its association with UCB-MSCs in macrophage polarization. We found that human PTX3 was secreted from UCB-MSCs under inflammation condition and reinforced the M2 macrophage marker via the Dectin-1 receptor by activating MSK1/2 phosphorylation signaling in NR8383 cells. Accordingly, knockdown of PTX3 in UCB-MSCs significantly attenuated their therapeutic effects in a neonatal hyperoxic lung injury resulting in reduced survival, lung alveolarization, M2 marker expression, Dectin-1 levels, anti-inflammatory cytokines, and improved M1 marker expression and inflammatory cytokines compared to control MSC-injected rats. UCB-MSCs show therapeutic potential by controlling macrophage polarization. Interestingly, higher PTX3 levels in UCB-MSCs induced greater improvement in the therapeutic effects than lower PTX3 levels. Collectively, PTX3 is a potential marker with critical paracrine effects for predicting the therapeutic potential of MSC therapy in inflammatory diseases; quality control assessments using PTX3 may be useful for improving the therapeutic effects of UCB-MSCs.

Up-Regulation of Superoxide Dismutase 2 in 3D Spheroid Formation Promotes Therapeutic Potency of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells.

Umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) are accessible, available in abundance, and have been shown to be a promising source that can regenerate cartilage in patients with osteoarthritis or other orthopedic diseases. Recently, a three-dimensional (3D) cell culture system was developed to mimic the naive tissue microenvironment. However, the efficacy of cells generated from the 3D spheroid culture system has not yet been elucidated. In the present study, we demonstrate the changes in superoxide dismutase 2 (SOD2) gene expression, an indicator of oxidative stress, on 3D spheroid MSCs. Moreover, siRNA transfection and neutralizing antibody investigations were performed to confirm the function of SOD2 and E-cadherin. Overall, we found that SOD2 siRNA transfection in the spheroid form of MSCs increases the expression of apoptotic genes and decreases the clearance of mitochondrial reactive oxygen species (ROS). As a result, we confirm that 3D spheroid formation increases E-cadherin and SOD2 expression, ultimately regulating the phosphoinositide 3-kinase (PI3K/pAkt/pNrf2 and pERK/pNrf2 signaling pathway. Additionally, we show that SOD2 expression on 3D spheroid MSCs affects the regeneration rates of destructive cartilage in an osteoarthritic model. We postulate that the impact of SOD2 expression on 3D spheroid MSCs reduces oxidative stress and apoptosis, and also promotes cartilage regeneration.

Exosomes derived from adipose tissue, bone marrow, and umbilical cord blood for cardioprotection after myocardial infarction

Human mesenchymal stem cells (MSCs) have the potential for improving cardiac function following myocardial infarction (MI). This study was performed to explore the cardioprotection of bone marrow mesenchymal stem cells (BMMSCs), adipose tissue-derived mesenchymal stem cells (ADMSCs), and umbilical cord blood-derived mesenchymal stem cells (UCBMSCs) for myocardium in rats after MI. MI models were established in rats, which were injected with PBS, BMMSCs, ADMSCs, and UCMSCs. Cardiac function was detected by ultrasonic cardiogram. TTC staining, TUNEL staining, and immunohistochemistry were adopted to determine infarction area, cardiomyocyte apoptosis, and microvascular density (MVD), respectively. Exosomes were derived from BMMSCs, ADMSCs, and UCBMSCs, and identified by morphological observation and CD63 expression detection. Neonatal rat cardiomyocytes (NRCMs) were isolated and cultured with hypoxia, subjected to PBS and exosomes derived from BMMSCs, ADMSCs, and UCMSCs. Flow cytometry and enzyme-linked immunosorbent assay were used to determine NRCM apoptosis and the levels of angiogenesis-related markers (VEGF, bFGF, and HGF). According to ultrasonic cardiogram, BMMSCs, ADMSCs, and UCMSCs facilitated the cardiac function of MI rats. Furthermore, three kinds of MSCs inhibited cardiomyocyte apoptosis, infarction area, and increased MVD. NRCMs treated with exosomes derived from BMMSCs, ADMSCs, and UCMSCs reduced the NRCM apoptosis and promoted angiogenesis by increasing levels of VEGF, bFGF, and HGF. Notably, exosomes from ADMSCs had the most significant effect. On the basis of the results obtained from this study, exosomes derived from BMMSCs, ADMSCs, and UCBMSCs inhibited the cardiomyocyte apoptosis and promoted angiogenesis, thereby improving cardiac function and protecting myocardium. Notably, exosomes from ADMSCs stimulated most of the cardioprotection factors.

Mesenchymal stem cells for the prevention of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease in preterm infants who have been treated with supplemental oxygen and mechanical ventilation. Despite major advances in perinatal and neonatal medicine, limited progress has been made in reducing BPD rates. The use of mesenchymal stem cells (MSC) is a promising and innovative therapy for several diseases because they are easy to extract and they have low immunogenicity, anti-inflammatory properties, and regenerative ability. According to several pre-clinical studies that have used BPD animal models, one mechanism of action for MSC in BPD is mainly due to the paracrine effects of MSC-derived humoral factors, such as interleukin (IL)-6, IL-8, vascular endothelial growth factor, collagen, and elastin, rather than the multilineage and regenerative capacities of MSC. Cell-free preparations derived from MSC, including conditioned media and exosomes, remain a pre-clinical technology despite their great clinical potential. A first-in-human clinical trial of MSC treatment for BPD was performed as a phase I dose-escalation trial using umbilical cord blood-derived MSC. That trial demonstrated the short- and long-term safety and feasibility of MSC, given that significantly reduced inflammatory marker expression was observed in tracheal aspirates. As of recently, several clinical trials of MSC use for BPD are ongoing or are planned in some countries to investigate the efficacy of MSC in the prevention or treatment of BPD in premature infants. Many clinicians are currently awaiting the results from these trials so that MSC can be used clinically for human BPD.

Decorin Secreted by Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Induces Macrophage Polarization via CD44 to Repair Hyperoxic Lung Injury.

Bronchopulmonary dysplasia (BPD), caused by hyperoxia in newborns and infants, results in lung damage and abnormal pulmonary function. However, the current treatments for BPD are steroidal and pharmacological therapies, which cause neurodevelopmental impairment. Treatment with umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) is an efficient alternative approach. To prevent pulmonary inflammation in BPD, this study investigated the hypothesis that a key regulator was secreted by MSCs to polarize inflammatory macrophages into anti-inflammatory macrophages at inflammation sites. Lipopolysaccharide-induced macrophages co-cultured with MSCs secreted low levels of the inflammatory cytokines, IL-8 and IL-6, but high levels of the anti-inflammatory cytokine, IL-10. Silencing decorin in MSCs suppressed the expression of CD44, which mediates anti-inflammatory activity in macrophages. The effects of MSCs were examined in a rat model of hyperoxic lung damage. Macrophage polarization differed depending on the levels of decorin secreted by MSCs. Moreover, intratracheal injection of decorin-silenced MSCs or MSCs secreting low levels of decorin confirmed impaired alveolarization of damaged lung tissues by down-regulation of decorin. In tissues, a decrease in the anti-inflammatory macrophage marker, CD163, was observed via CD44. Thus, we identified decorin as a key paracrine factor, inducing macrophage polarization via CD44, a master immunoregulator in mesenchymal stem cells.

The Upregulation of Toll-Like Receptor 3 via Autocrine IFN-β Signaling Drives the Senescence of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Through JAK1.

Although mesenchymal stromal cells (MSCs) are among the most promising cell sources for cell-based therapies and regenerative medicine, the decline in their function with age due to cellular senescence limits their therapeutic applications. Unveiling the underlying mechanism of MSC senescence is therefore of substantial interest with regard to advancing MSC-based cell therapies. We here show that the induction of human umbilical cord blood-derived MSC (UCB-MSC) senescence causes the predominant upregulation of Toll-like receptor 3 (TLR3). Subsequent TLR3 activation by polyinosinic-polycytidylic acid triggers the prominent features of senescence. Using a clustered regularly interspaced short palindromic repeats/Cas9 library screening system, we identified Janus kinase 1 (JAK1) as the candidate regulatory factor for TLR3-mediated MSC senescence. A JAK1 deficiency blocked the MSC senescence phenotype upon TLR3 activation and TLR3 induction. Targeting the JAK1 pathway using chemical JAK1 inhibitors also significantly suppressed TLR3-mediated MSC senescence. Importantly, we further observed that UCB-MSC senescence is driven by a senescence-associated secretory phenotype (SASP) and that interferon-β (IFN-β) is a component of TLR3-dependent SASP, whereby its autocrine actions upregulate TLR3 and suppress cell proliferation. A JAK1 depletion significantly interrupted these effects of IFN-β, indicating that JAK1 is a signaling mediator linking IFN-β activity to TLR3 expression and the process of MSC senescence. Collectively, our findings provide new mechanistic insights into UCB-MSC senescence by revealing the role of an autocrine regulatory loop of SASP evoked by TLR3 activation.

Effects of hepatocyte growth factor gene-transfected mesenchymal stem cells on dimethylnitrosamine-induced liver fibrosis in rats

Nowadays, transplantation of human mesenchymal stem cells (MSCs) has emerged as a potential cellular therapy for liver cirrhosis. Hepatocyte growth factor (HGF) plays an important role in the regeneration of the liver. The objective of the study was to investigate the therapeutic effect of HGF-transfected human umbilical cord blood-derived MSCs on dimethylnitrosamine (DMN)-induced liver fibrosis in rats. HGF-transfected MSCs were transplanted into rats with DMN-induced liver fibrosis. H2O2-induced cytotoxicity, apoptosis and intracellular reactive oxygen species were reduced in HGF-transfected MSCs in HGF-transfected MSCs. Pro-apoptotic proteins, such as cleaved poly (ADP-ribose) polymerase and cleaved caspase-3, were decreased in HGF-transfected MSCs. Biochemical analysis showed that the levels of aspartate aminotransferase and alanine aminotransferase were decreased after transplantation of HGF-transfected MSCs in rat fibrosis. Trichrome staining showed that HGF-transfected MSCs reduced liver damage. Taken together, our study indicated that HGF-transfected MSCs have therapeutic effects on DMN-induced liver fibrosis in rats.

Transplantation of stem cells from umbilical cord blood as therapy for type I diabetes.

In recent years, human umbilical cord blood has emerged as a rich source of stem, stromal and immune cells for cell-based therapy. Among the stem cells from umbilical cord blood, CD45+ multipotent stem cells and CD90+ mesenchymal stem cells have the potential to treat type I diabetes mellitus (T1DM), to correct autoimmune dysfunction and replenish β-cell numbers and function. In this review, we compare the general characteristics of umbilical cord blood-derived multipotent stem cells (UCB-SCs) and umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) and introduce their applications in T1DM. Although there are some differences in surface marker expression between UCB-SCs and UCB-MSCs, the two cell types display similar functions such as suppressing function of stimulated lymphocytes and imparting differentiation potential to insulin-producing cells (IPCs) in the setting of low immunogenicity, thereby providing a promising and safe approach for T1DM therapy.

Mechanisms of the mixed umbilical cord blood-derived mesenchymal stem cells in inhibiting proliferation and inducing apoptosis of glioma cells

Objective To investigate the possible mechanism of mixed umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) in vitro to inhibit proliferation and induce apoptosis of C6 glioma cells. Methods The expression of B cell lymphoma/leukemia-2 (bcl-2) and cysteinyl aspartate-specific protease (Caspase)-3 proteins in C6 cells was detected by immunohistochemistry and Western blotting imprinting method, and C6 cell cycle was detected by flow cytometry. Results Different sources of UCB-MSCs have a tendency to increase the expression of apoptosis protein Caspase-3 in C6 cells and reduce the expression of apoptosis protein bcl-2. Different sources UCB-MSCs induce C6 cell apoptosis, E/T=0∶1, 5∶1, (2.5+ 2.5)∶1, 10∶1, (5+ 5)∶1 C6 cells acting on, The percentages of G0/G1 were (65.49±1.83)%, (64.83±2.19)%, (70.30±3.21)%, (69.03±2.19)%, (77.63±3.10)%, and the percentage of C6 cells in G0/G1 increased with the increase of the E/T ratio, showing a proportional dependence. Conclusion After phytohemagglutinin (PHA) stimulation, large doses of UCB-MSCs and mixed UCB-MSCs have inhibitory effects on proliferation of C6 cells in vitro, and this inhibition may be related to apoptosis induction Key words: Mesenchymal stem cells; Induce; Apoptosis

Interferon-γ-mediated secretion of tryptophanyl-tRNA synthetases has a role in protection of human umbilical cord blood-derived mesenchymal stem cells against experimental colitis

Mesenchymal stem cells (MSCs) are multipotent adult stem cells that present immunosuppressive effects in experimental and clinical trials targeting various rare diseases including inflammatory bowel disease (IBD). In addition, recent studies have reported tryptophanyl-tRNA synthetase (WRS) possesses uncanonical roles such as angiostatic and anti-inflammatory effects. However, little is known about the function of WRS in MSC-based therapy. In this study, we investigated if a novel factor, WRS, secreted from MSCs has a role in amelioration of IBD symptoms and determined a specific mechanism underlying MSC therapy. Experimental colitis was induced by administration of 3% DSS solution to 8-week-old mice and human umbilical cord blood-derived MSCs (hUCB-MSCs) were injected intraperitoneally. Secretion of WRS from hUCB-MSCs and direct effect of WRS on isolated CD4+ T cells was determined via in vitro experiments and hUCB-MSCs showed significant therapeutic rescue against experimental colitis. Importantly, WRS level in serum of colitis induced mice decreased and recovered by administration of MSCs. Through in vitro examination, WRS expression of hUCB-MSCs increased when cells were treated with interferon-γ (IFN-γ). WRS was evaluated and revealed to have a role in inhibiting activated T cells by inducing apoptosis. In summary, IFN-γ-mediated secretion of WRS from MSCs has a role in suppressive effect on excessive inflammation and disease progression of IBD and brings new highlights in the immunomodulatory potency of hUCB-MSCs.

PPIA, HPRT1, and YWHAZ Genes Are Suitable for Normalization of mRNA Expression in Long-Term Expanded Human Mesenchymal Stem Cells.

Long-term expansion of mesenchymal stem cells (MSCs) under defined culture conditions is necessary in human stem cell therapy. However, it alters the characteristics of MSCs. Since quantitative real time polymerase chain reaction (qRT-PCR) is widely used as one of the key analytical methods for comparative characterization, the validation of reference genes (RGs) for normalization under each experimental condition is important to achieve reliable qRT-PCR results. Therefore, the most stable RGs for long-term expanded bone marrow- and umbilical cord blood-derived MSCs (BM-MSCs and UCB-MSCs) under defined culture conditions for up to 20 passages were evaluated. The more apparent alterations in characteristics such as differentiation capacity, proliferation, senescence, and the expression of RGs were noted in BM-MSCs than UCB-MSCs during long-term expansion. The RG validation programs (GeNorm and NormFinder) suggested that PPIA, HPRT1, and YWHAZ were suitable for normalization in qRT-PCR regardless of MSC types and long-term culture expansion, and the traditional RGs (ACTB and GAPDH) were less stable in long-term expanded MSCs. In addition, the use of these RGs for normalization of OCT4 expression in long-term expanded BM-MSCs showed that a less stable RG (GAPDH) showed contrasting data compared to other RGs. Therefore, the use of RGs such as PPIA, HPRT1, and YWHAZ for normalization in qRT-PCR experiments is highly recommended for long-term expanded MSCs to generate accurate and reliable data.

Fabrication of bacterial cellulose-collagen composite scaffolds and their osteogenic effect on human mesenchymal stem cells

Scaffold plays a critical role in stem cell differentiation and tissue regeneration. Composite scaffolds composed of bacterial cellulose (BC) and collagen (Col) in different ratios (1:1, 3:1, 5:1) were fabricated in this study. The composite scaffolds exhibit a well-organized interconnected porous structure, significantly better physical stability than Col scaffold, and more water uptake up to 400%. They were also favorable with cell attachment and growth. After osteogenic induction of umbilical cord blood derived mesenchymal stem cells (UCB-MSCs) for 3 weeks, we found more up-regulated osteogenic markers (collagen type 1, osteocalcin, bone sialoprotein) and significantly elevated proteins and calcium deposition, particularly with BC/Col (5:1) scaffold. When PKH-26 pre-labelled MSC-loaded scaffolds were subcutaneously transplanted in a mouse model, they showed many PKH-26-labelled cells and positive signals of α-smooth muscle actin, for neovascularization in the BC/Col (5:1). The current work demonstrates that our BC/Col composites may be promising as a bone tissue-engineered scaffold.

Mechanisms of mixed umbilical cord blood-derived mesenchymal stem cells inhibiting proliferation and inducing apoptosis of C6 glioma cells in vitro

Objective To study the mechanisms of the mixed umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) inhibiting proliferation and inducing apoptosis of C6 glioma cells in vitro. Methods Cysteinyl aspartate-specific protease (Caspase)-8, B cell lymphoma/leukemia-2 associated X protein (bax), B cell lymphoma/leukemia-2 (bcl-2) and Caspase-3 protein expression in C6 cells was analyzed by immunohistochemistry and Western blotting, respectively. Caspase-8, bax, bcl-2 and Caspase-3 mRNA levels were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Cell cycle was detected by flow cytometry. Apoptosis of C6 cells was examined by Annexin V-propidium iodide (PI) staining and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) methods, respectively. Results The mixed UCB-MSCs had a tendency to increase the expression of Caspase-8, bax, Caspase-3 mRNA, and decrease the expression of bcl-2 mRNA. The expression of apoptosis protein and the number of apoptosis cells increased with the increase of the ratio of E/T (E: effect cells namely UCB-MSCs; T: target cells namely C6 cells), showing a proportional dependence relationship; E∶T=(5+ 5)∶1. The relative expression of Caspase-8, bax, bcl-2, and Caspase-3 mRNA in C6 cells was 0.78±0.13, 0.28±0.03, 0.70±0.08, and 0.76±0.12, respectively. When E/T=0∶1, 5∶1, (2.5+ 2.5)∶1, 10∶1, (5+ 5)∶1, the number of apoptosis C6 cells was (2.9±0.6), (3.1±0.5), (14.5±1.8), (14.3±2.2), and (22.8±4.5) cells, respectively. Conclusion After phytohemagglutinin (PHA) stimulation, the mixed UCB-MSCs could inhibit proliferation of C6 cells in vitro, which was related to induction of apoptosis of glioma cells. Key words: Glioma; Umbilical cord blood; Mesenchymal stem cells; Apoptosis; Proliferation

Intra-Articular Injection of 2 Different Dosages of Autologous and Allogeneic Bone Marrow- and Umbilical Cord-Derived Mesenchymal Stem Cells Triggers a Variable Inflammatory Response of the Fetlock Joint on 12 Sound Experimental Horses.

Osteoarthritis is a significant and costly cause of pain for both humans and horses. The horse has been identified as a suitable model for human osteoarthritis. Regenerative therapy with allogeneic mesenchymal stem cells (MSCs) is a promising treatment, but the safety of this procedure continues to be debated. The aim of this study is to evaluate the safety of intra-articular injections of allogeneic MSCs on healthy joints by comparing two different dosages and two different tissue sources, namely, bone marrow and umbilical cord blood, with a placebo treatment on the same individuals. We also assessed the influence of autologous versus allogeneic cells for bone marrow-derived MSC treatment. Twelve clinically sound horses were subjected to injections in their 4 fetlock joints. Each of the three fetlocks was administered a different MSC type, and the remaining fetlock was injected with phosphate-buffered saline as a control. Six horses received 10 million cells per joint, and the 6 other horses received 20 million cells per joint. Clinical and ultrasound monitoring revealed that allogeneic bone marrow-derived MSCs induced significantly more synovial effusion compared to umbilical cord blood-derived MSCs but no significant difference was noted within the synovial fluid parameters. The administration of 10 million cells in horses triggered significantly more inflammatory signs than the administration of 20 million cells. Mesenchymal stem cell injections induced mild to moderate local inflammatory signs compared to the placebo, with individual variability in the sensitivity to the same line of MSCs. Understanding the behavior of stem cells when injected alone is a step towards the safer use of new strategies in stem cell therapy, where the use of either MSC secretome or MSCs combined with biomaterials could enhance their viability and metabolic activity.

TGF-beta in the UCB-MSCs inhibit TNF-alpha in human mast cells and atopic dermatitis

Abstract It is well known that umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) have been effective therapy in autoimmune inflammatory disease such as atopic dermatitis (AD), rheumatoid arthritis (RA) and psoriasis. Especially, UCB-MSC has a prominent therapeutic effect on AD. However, there is not much research on the mechanism of alleviation of AD by UCB-MSCs. In this study, we investigated the mechanism of AD therapy by UCB-MSCs, using human mast cells as the major pathogenic cells in AD. LAD2 cells were stimulated with IL- 33(30ng/ml) and Ionomycin (1uM) under IgE-XL condition and they secreted a significant amount of TNF-a. TNFa was significantly inhibited by co-culture with UCB-MSCs. UCB-MSCs secreted TGF-beta and PGE2, which play a crucial role in immune regulation. TNF-a of LAD2 was increased when co-cultured with UCB-MSCs after TGF-b siRNA transfection. Nevertheless, inhibition of PGE2 using indomethacin, NS398 and celecoxib did not restore secretion of TNF-a. At the protein level, we examined the ERK, JNK and AKT signaling pathways involved in TNF-α, and only the ERK signaling pathway was associated with TNF-α inhibition. Finally, we found that TNFa is regulated by TGFb induced by UCB-MSC in a DF-induced mouse model. Taken together, our findings suggest that TGF-b may play an important role in regulating mast cells in AD rather than PGE2 in UCB-MSCs.

Photobiomodulation Enhances the Angiogenic Effect of Mesenchymal Stem Cells to Mitigate Radiation-Induced Enteropathy.

Radiation-induced enteropathy remains a major complication after accidental or therapeutic exposure to ionizing radiation. Recent evidence suggests that intestinal microvascular damage significantly affects the development of radiation enteropathy. Mesenchymal stem cell (MSC) therapy is a promising tool to regenerate various tissues, including skin and intestine. Further, photobiomodulation (PBM), or low-level light therapy, can accelerate wound healing, especially by stimulating angiogenesis, and stem cells are particularly susceptible to PBM. Here, we explored the effect of PBM on the therapeutic potential of MSCs for the management of radiation enteropathy. In vitro, using human umbilical cord blood-derived MSCs, PBM increased proliferation and self-renewal. Intriguingly, the conditioned medium from MSCs treated with PBM attenuated irradiation-induced apoptosis and impaired tube formation in vascular endothelial cells, and these protective effects were associated with the upregulation of several angiogenic factors. In a mouse model of radiation-induced enteropathy, treatment with PBM-preconditioned MSCs alleviated mucosal destruction, improved crypt cell proliferation and epithelial barrier functions, and significantly attenuated the loss of microvascular endothelial cells in the irradiated intestinal mucosa. This treatment also significantly increased angiogenesis in the lamina propria. Together, we suggest that PBM enhances the angiogenic potential of MSCs, leading to improved therapeutic efficacy for the treatment of radiation-induced enteropathy.

CRISPR/Cas9 Edited sRAGE-MSCs Protect Neuronal Death in Parkinson’s Disease Model.

Background and ObjectivesParkinson’s disease (PD) is a fatal and progressive degenerative disease of the nervous system. Until recently, its promising treatment and underlying mechanisms for neuronal death are poorly understood. This study was investigated to identify the molecular mechanism of neuronal death in the substantia nigra and corpus striatum of PD.MethodsThe soluble RAGE (sRAGE) secreting Umbilical Cord Blood—derived Mesenchymal Stem Cell (UCB-MSC) was generated by gene editing method using clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9 (CRISPR/Cas9). These cells were transplanted into Corpus Striatum of rotenone-induced PD animal models then behavioral test, morphological analysis, and immunohistochemical experiments were performed to determine the neuronal cell death and recovery of movement.ResultsThe neuronal cell death in Corpus Striatum and Substantia Nigra was dramatically reduced and the movement was improved after sRAGE secreting UCB-MSC treatment in PD mice by inhibition of RAGE in neuronal cells.ConclusionsWe suggest that sRAGE secreting UCB-MSC based therapeutic approach could be a potential treatment strategy for neurodegenerative disease including PD.

MiRNA-21 promotes osteogenesis via the PTEN/PI3K/Akt/HIF-1\u03b1 pathway and enhances bone regeneration in critical size defects

BackgroundFunctional reconstruction of maxillofacial bone defects is a considerable clinical challenge. Many studies have emphasized the osteogenic and angiopoietic abilities of stem cells for tissue regeneration. We previously showed that microRNA-21 (miRNA-21) can promote angiogenesis in human umbilical cord blood-derived mesenchymal stem cells (UCBMSCs). In the present study, the role of miRNA-21 in osteogenic differentiation of bone marrow-derived stem cells (BMSCs) was investigated.MethodsWestern blotting and qPCR were performed to investigate the influences of miRNA-21 on osteogenic differentiation of BMSCs. The effects of miRNA-21 on PTEN/PI3K/Akt/HIF-1α pathway were also assessed using western blotting. To further evaluate the roles of miRNA-21 in osteogenesis in vivo, we conducted animal experiments in rat and canine. New bone formation was assessed using micro-CT and histological methods.ResultsIn the present study, we found that miRNA-21 promotes the migration and osteogenic differentiation of bone marrow-derived stem cells (BMSCs) in vitro. Using gain- and loss-of-function studies, we found that miRNA-21 promoted the osteogenic ability of BMSCs by increasing P-Akt and HIF-1α activation. Finally, we verified the essential role of miRNA-21 in osteogenesis by implanting a miRNA-21-modified BMSCs/β-tricalcium phosphate (β-TCP) composite into critical size defects. Radiography, micro-CT, and histology revealed significantly greater volume of new bone formation in the miRNA-21 group than in the control group.ConclusionIn conclusion, our study demonstrated an essential role of miRNA-21 in promoting maxillofacial bone regeneration via the PTEN/PI3K/Akt/HIF-1α pathway.