This study aims to investigate the using of bone marrow mesenchymal stem cells (BMSCs) genetically engineered to produce interferon-β (IFN-β) as a gene delivery system to treat hepatocellular carcinoma (HCC) in vitro and in vivo.
To measure the effects on tumour cell growth in vitro, IFN-β-producing BMSCs (BMSC/IFN-β) were co-cultured with the HCC cell line HepG2 and Huh7. Enzyme-linked immunosorbent assay (ELISA) was used to detect the IFN-β secretion in the BMSC culture condition medium (CM). The effect of BMSC/IFN-β on HCC cells proliferation was examined both in vitro and in vivo by using MTT, colony formation assay, BrdU staining, cell cycle analysis, and xenografted NOD/SCID mouse tumour model. To examine the impact of BMSC/IFN-β on the AKT/FOXO3a signalling, RT–PCR and western blotting were performed.
The BMSC/IFN-β cells can stably secrete high levels of IFN-β. Both MTT and colony forming assay showed that HCC cells had a lower growth rate when cultured in BMSC/IFN-β-CM as compared with that in BMSC/vector-CM or DMEM culture group. Co-culture with BMSC/IFN-β-CM dramatically decreased the percentages of cells with incorporated BrdUrd. In BMSC/IFN-β-CM-treated HCC cells, the proportion of G1-phase cells increased but it decreased in the S phase of the cell. The BMSC/IFN-β inhibited HCC growth in NOD/SCID mice and proved the survival period of these mice. Compared with the control group, p21 and p27 expression of hepatoma cells increased, whereas cyclin D1 and phosphorylation of Rb expression decreased when co-cultured with BMSC/IFN-β-CM. It was associated with suppression of Akt activity and enhanced transcriptional activity of FOXO3a.
The IFN-β gene-modified BMSCs can effectively inhibit the proliferation of HCC cells in vitro and in vivo through inhibiting AKT/FOXO3a pathway. These results indicate that BMSC/IFN-β are a powerful anticancer cytotherapeutic tool for HCC.
IFN-β; hepatocellular carcinoma; BMSC; FOXO3a; AKT
Bronchopulmonary dysplasia develops in preterm infants due to a combination of lung immaturity and lung injury. Cultured pluripotent bone marrow stem cells (BMSC) are known to reduce injury and induce repair in adult and in immature lungs, possibly through paracrine secretion of soluble factors. The paracrine relationship between BMSC and primary fetal lung epithelial type II cells is unknown. We determined the effects of BMSC on type II cell and fibroblast behavior using an in vitro co-culture model. Rat BMSC were isolated and co-cultured with primary fetal E21 rat type II cells or lung fibroblasts in a Transwell® system without direct cell contact. Effects of BMSC conditioned media (CM) on type II cell and fibroblast proliferation and on type II cell surfactant phospholipid (DSPC) synthesis and mRNA expression of surfactant proteins B and C (sftpb and sftpc) were studied. We also determined the effect of fibroblast and type II cell CM on BMSC proliferation and surface marker expression. Co-culture with BMSC significantly decreased type II cell and fibroblast proliferation to 72.5% and 83.7% of controls, respectively. Type II cell DSPC synthesis was significantly increased by 21% and sftpb and sftpc mRNA expressions were significantly induced (2.1 fold and 2.4 fold, respectively). BMSC proliferation was significantly reduced during the co-culture. Flow cytometry confirmed that BMSC retained the expression of undifferentiated stem cell markers despite their exposure to fetal lung cell CM. We conclude that BMSC induce fetal type II cell differentiation through paracrine release of soluble factors. These studies provide clues for how BMSC may act in promoting alveolar repair following injury.
Lung development; surfactant; proliferation; co-culture; lung fibroblasts.
Bone marrow-derived mesenchymal stem cells (BMSCs) could modulate inflammation in experimental lung injury. On the other hand, adrenergic receptor agonists could increase DNA synthesis of stem cells. Therefore, we investigated the therapeutic role of adrenaline-stimulated BMSCs on lipopolysaccharide (LPS)-induced lung injury. BMSCs were cultured with adrenergic receptor agonists or antagonists. Suspensions of lung cells or sliced lung tissue from animals with or without LPS-induced injury were co-cultured with BMSCs. LPS-stimulated alveolar macrophages were co-cultured with BMSCs (with adrenaline stimulation or not) in Transwell for 6 hrs. A preliminary animal experiment was conducted to validate the findings in ex vivo study. We found that adrenaline at 10 μM enhanced proliferation of BMSCs through both α- and β-adrenergic receptors. Adrenaline promoted the migration of BMSCs towards LPS-injured lung cells or lung tissue. Adrenaline-stimulated BMSCs decreased the inflammation of LPS-stimulated macrophages, probably through the expression and secretion of several paracrine factors. Adrenaline reduced the extent of injury in LPS-injured rats. Our data indicate that adrenaline-stimulated BMSCs might contribute to the prevention from acute lung injury through the activation of adrenergic receptors, promotion of proliferation and migration towards injured lung, and modulation of inflammation.
acute lung injury; mesenchymal stem cells; lipopolysaccharide; inflammation; adrenergic receptor agonists
Rationale: Bronchopulmonary dysplasia (BPD) and emphysema are characterized by arrested alveolar development or loss of alveoli; both are significant global health problems and currently lack effective therapy. Bone marrow–derived mesenchymal stem cells (BMSCs) prevent adult lung injury, but their therapeutic potential in neonatal lung disease is unknown.
Objectives: We hypothesized that intratracheal delivery of BMSCs would prevent alveolar destruction in experimental BPD.
Methods: In vitro, BMSC differentiation and migration were assessed using co-culture assays and a modified Boyden chamber. In vivo, the therapeutic potential of BMSCs was assessed in a chronic hyperoxia-induced model of BPD in newborn rats.
Measurements and Main Results: In vitro, BMSCs developed immunophenotypic and ultrastructural characteristics of type II alveolar epithelial cells (AEC2) (surfactant protein C expression and lamellar bodies) when co-cultured with lung tissue, but not with culture medium alone or liver. Migration assays revealed preferential attraction of BMSCs toward oxygen-damaged lung versus normal lung. In vivo, chronic hyperoxia in newborn rats led to air space enlargement and loss of lung capillaries, and this was associated with a decrease in circulating and resident lung BMSCs. Intratracheal delivery of BMSCs on Postnatal Day 4 improved survival and exercise tolerance while attenuating alveolar and lung vascular injury and pulmonary hypertension. Engrafted BMSCs coexpressed the AEC2-specific marker surfactant protein C. However, engraftment was disproportionately low for cell replacement to account for the therapeutic benefit, suggesting a paracrine-mediated mechanism. In vitro, BMSC-derived conditioned medium prevented O2-induced AEC2 apoptosis, accelerated AEC2 wound healing, and enhanced endothelial cord formation.
Conclusions: BMSCs prevent arrested alveolar and vascular growth in part through paracrine activity. Stem cell–based therapies may offer new therapeutic avenues for lung diseases that currently lack efficient treatments.
stem cells; aging; lung; oxygen
Many studies have shown that microglia in the activated state may be neurotoxic. It has been proven that uncontrolled or over-activated microglia play an important role in many neurodegenerative disorders. Bone marrow-derived mesenchymal stem cells (BMSCs) have been shown in many animal models to have a therapeutic effect on neural damage. Such a therapeutic effect is attributed to the fact that BMSCs have the ability to differentiate into neurons and to produce trophic factors, but there is little information available in the literature concerning whether BMSCs play a therapeutic role by affecting microglial activity. In this study, we triggered an inflammatory response situation in vitro by stimulating microglia with the bacterial endotoxin lipopolysaccharide (LPS), and then culturing these microglia with BMSC-conditioned medium (BMSC-CM). We found that BMSC-CM significantly inhibited proliferation and secretion of pro-inflammatory factors by activated microglia. Furthermore, we found that the phagocytic capacity of microglia was also inhibited by BMSC-CM. Finally, we investigated whether the induction of apoptosis and the production of nitric oxide (NO) were involved in the inhibition of microglial activation. We found that BMSC-CM significantly induced apoptosis of microglia, while no apoptosis was apparent in the LPS-stimulated microglia. Our study also provides evidence that NO participates in the inhibitory effect of BMSCs. Our experimental results provide evidence that BMSCs have the ability to maintain the resting phenotype of microglia or to control microglial activation through their production of several factors, indicating that BMSCs could be a promising therapeutic tool for treatment of diseases associated with microglial activation.
Mast cells (MCs) have a central role in the induction of allergic inflammation, such as seen in asthma, and contribute to the severity of certain autoimmune diseases, such as rheumatoid arthritis. The mast cell thus represents an important inflammatory cell, and one which has resisted therapeutic attempts to alter its role in disease.
Because bone marrow-derived stromal cells (BMSC, also known as mesenchymal stem cells or MSCs) have been reported to alter allergic inflammation in vivo, we chose to study the interaction between mouse BMSC and mouse bone marrow derived MCs.
MC degranulation, cytokine production and chemotaxis were evaluated in vitro following co-culture with BMSCs either in cell contact or a transwell. In addition, MC degranulation was assessed in vivo following administration of BMSCs in a model of passive cutaneous anaphylaxis and a peritoneal degranulation assay. Mechanisms of MC suppression by BMSCs were determined through use of inhibitors or antibodies to COX1, COX2, nitric oxide, indoleamine 2, 3-dioxygenase, EP1-4 receptors, TGF-β and IL-10. Lastly, we utilized either BMSCs or MCs deficient in COX1, COX2 or EP1-4 receptors to confirm the mechanisms of inhibition of MC function by BMSCs.
We discovered that BMSCs will effectively suppress specific MC functions in vitro as well as in vivo. When MCs are cocultured with BMSCs to allow cell-to-cell contact, BMSCs suppressed MC degranulation, proinflammatory cytokine production, chemokinesis and chemotaxis. Similarly, MC degranulation within mouse skin or the peritoneal cavity was suppressed following in vivo administration of BMSCs. Further, we found that these inhibitory effects were dependent on up-regulation of COX2 in BMSCs; and were facilitated through the activation of EP4 receptors on MCs.
Conclusion and Clinical Relevance
These observations support the concept that BMSCs have the ability to suppress mast cell activation and therefore could be the basis for a novel cell based therapeutic approach in the treatment of MC driven inflammatory diseases.
Stromal cell; mesenchymal stem cell; EP4 receptor; allergy; COX2
Lung fibrosis is characterized by vascular leakage and myofibroblast recruitment, and both phenomena are mediated by lysophosphatidic acid (LPA) via its type-1 receptor (LPA1). Following lung damage, the accumulated myofibroblasts activate and secrete excessive extracellular matrix (ECM), and form fibrotic foci. Studies have shown that bone marrow-derived cells are an important source of myofibroblasts in the fibrotic organ. However, the type of cells in the bone marrow contributing predominantly to the myofibroblasts and the involvement of LPA-LPA1 signalling in this is yet unclear. Using a bleomycin-induced mouse lung-fibrosis model with an enhanced green fluorescent protein (EGFP) transgenic mouse bone marrow replacement, we first demonstrated that bone marrow derived-mesenchymal stem cells (BMSCs) migrated markedly to the bleomycin-injured lung. The migrated BMSC contributed significantly to α-smooth muscle actin (α-SMA)-positive myofibroblasts. By transplantation of GFP-labelled human BMSC (hBMSC) or EGFP transgenic mouse BMSC (mBMSC), we further showed that BMSC might be involved in lung fibrosis in severe combined immune deficiency (SCID)/Beige mice induced by bleomycin. In addition, using quantitative-RT-PCR, western blot, Sircol collagen assay and migration assay, we determined the underlying mechanism was LPA-induced BMSC differentiation into myofibroblast and the secretion of ECM viaLPA1. By employing a novel LPA1 antagonist, Antalpa1, we then showed that Antalpa1 could attenuate lung fibrosis by inhibiting both BMSC differentiation into myofibroblast and the secretion of ECM. Collectively, the above findings not only further validate LPA1 as a drug target in the treatment of pulmonary fibrosis but also elucidate a novel pathway in which BMSCs contribute to the pathologic process.
mesenchymal stem cells; lysophosphatidic acid; lung fibrosis; myofibroblasts; Antalpa1
Previous studies indicated that bone marrow mesenchymal stem cells (BMSCs) from patients with systemic lupus erythematosus (SLE) exhibited impaired capacities of proliferation, differentiation, and immune modulation. Considering that migration capacity is important for the exertion of BMSCs functions, the defects in migration might contribute to BMSCs dysfunction in SLE patients. In this study, we showed that the migration capacity of SLE BMSCs was remarkably impaired in comparison with those of healthy controls. Increased tumor necrosis factor α (TNF-α) in SLE serum significantly inhibited the migration capacity and in vivo homing capacity of SLE BMSCs via a specific TNF receptor I (TNFRI) manner, in which decreased HGF mRNA production caused by the activation of I kappa B kinase beta (IKK-β) pathway is partially involved. To our knowledge, this is the first report to discuss the possible mechanisms for impaired migration of BMSCs in SLE patients. Our results suggest that inhibition of TNF-α pathway might be helpful for accelerating BMSCs migration to the inflammatory microenvironment in SLE patients, thereby having a potential role in SLE treatment.
Transplantation with bone marrow-derived mesenchymal stem cells (BMSCs) improves the survival of neurons and axonal outgrowth after stroke remains undetermined. Here, we investigated whether PI3K/AKT signaling pathway is involved in these therapeutic effects of BMSCs.
(1) BMSCs and cortical neurons were derived from Sprague-Dawley rats. The injured neurons were induced by Oxygen–Glucose Deprivation (OGD), and then were respectively co-cultured for 48 hours with BMSCs at different densities (5×103, 5×105/ml) in transwell co-culture system. The average length of axon and expression of GAP-43 were examined to assess the effect of BMSCs on axonal outgrowth after the damage of neurons induced by OGD. (2) The injured neurons were cultured with a conditioned medium (CM) of BMSCs cultured for 24 hours in neurobasal medium. During the process, we further identified whether PI3K/AKT signaling pathway is involved through the adjunction of LY294002 (a specific phosphatidylinositide-3-kinase (PI3K) inhibitor). Two hours later, the expression of pAKT (phosphorylated AKT) and AKT were analyzed by Western blotting. The length of axons, the expression of GAP-43 and the survival of neurons were measured at 48 hours.
Both BMSCs and CM from BMSCs inreased the axonal length and GAP-43 expression in OGD-injured cortical neurons. There was no difference between the effects of BMSCs of 5×105/ml and of 5×103/ml on axonal outgrowth. Expression of pAKT enhanced significantly at 2 hours and the neuron survival increased at 48 hours after the injured neurons cultured with the CM, respectively. These effects of CM were prevented by inhibitor LY294002.
BMSCs promote axonal outgrowth and the survival of neurons against the damage from OGD in vitro by the paracrine effects through PI3K/AKT signaling pathway.
Spinal cord injury triggers irreversible loss of motor and sensory functions. Numerous strategies aiming at repairing the injured spinal cord have been studied. Among them, the use of bone marrow-derived mesenchymal stem cells (BMSCs) is promising. Indeed, these cells possess interesting properties to modulate CNS environment and allow axon regeneration and functional recovery. Unfortunately, BMSC survival and differentiation within the host spinal cord remain poor, and these cells have been found to have various adverse effects when grafted in other pathological contexts. Moreover, paracrine-mediated actions have been proposed to explain the beneficial effects of BMSC transplantation after spinal cord injury. We thus decided to deliver BMSC-released factors to spinal cord injured rats and to study, in parallel, their properties in vitro. We show that, in vitro, BMSC-conditioned medium (BMSC-CM) protects neurons from apoptosis, activates macrophages and is pro-angiogenic. In vivo, BMSC-CM administered after spinal cord contusion improves motor recovery. Histological analysis confirms the pro-angiogenic action of BMSC-CM, as well as a tissue protection effect. Finally, the characterization of BMSC-CM by cytokine array and ELISA identified trophic factors as well as cytokines likely involved in the beneficial observed effects. In conclusion, our results support the paracrine-mediated mode of action of BMSCs and raise the possibility to develop a cell-free therapeutic approach.
The therapeutic action of bone marrow-derived mesenchymal stem cells (BMSCs) in acute kidney injury (AKI) has been reported by several groups. However, recent studies indicated that BMSCs homed to kidney tissues at very low levels after transplantation. The lack of specific homing of exogenously infused cells limited the effective implementation of BMSC-based therapies. In this study, we provided evidence that the administration of BMSCs combined with muscone in rats with gentamicin-induced AKI intravenously, was a feasible strategy to drive BMSCs to damaged tissues and improve the BMSC-based therapeutic effect. The effect of muscone on BMSC bioactivity was analyzed in vitro and in vivo. The results indicated that muscone could promote BMSC migration and proliferation. Some secretory capacity of BMSC still could be improved in some degree. The BMSC-based therapeutic action was ameliorated by promoting the recovery of biochemical variables in urine or blood, as well as the inhibition of cell apoptosis and inflammation. In addition, the up-regulation of CXCR4 and CXCR7 expression in BMSCs could be the possible mechanism of muscone amelioration. Thus, our study indicated that enhancement of BMSCs bioactivities with muscone could increase the BMSC therapeutic potential and further developed a new therapeutic strategy for the treatment of AKI.
Management of nonunion fracture and massive segmental bone defects in diabetes remains a challenging clinical problem. Bone marrow stromal cells (BMSCs) are crucial for bone remodeling and hold promise for bone regeneration. However, we have showed previously that diabetes can affect the proliferation and osteogenic potential of BMSCs adversely and a strategy to attenuate the impaired functions of BMSCs is required. Platelet-derived growth factor-BB (PDGF-BB) plays an important role in bone formation. However, little information is available about its effect on diabetic BMSCs. In this study, BMSCs were isolated from streptozotocin-induced diabetic rats. After treatment with recombinant human PDGF-BB (rhPDGF-BB), diabetic BMSCs demonstrated enhanced cell proliferation and osteogenic differentiation based on increased expressions of osteogenic genes (Runx2, alkaline phosphatase, and osteocalcin) and Runx2 protein, as well as upregulated alkaline phosphatase activity and mineralization. Furthermore, blocking extracellular signal regulated kinase (ERK) pathway by inhibitor PD98059 repressed the enhanced proliferation and osteogenic differentiation in diabetic BMSCs induced by rhPDGF-BB. Together, these results indicated that rhPDGF-BB stimulates proliferation and osteogenic differentiation partially through ERK pathway in diabetic BMSCs. Therefore, modulation of diabetic BMSCs could augment BMSCs function affected by diabetes and holds significance for future strategies to treat diabetic bone complications.
AIM: To investigate the therapeutic effects of Guiyuanfang and bone marrow stem cells (BMSCs) on rats with liver fibrosis.
METHODS: Liver fibrosis model was induced by carbon tetrachloride, ethanol, high lipid and assessed biochemically and histologically. Liver function and hydroxyproline contents of liver tissue were determined. Serum hyaluronic acid (HA) level and procollagen III level were performed by radioimmunoassay. The VG staining was used to evaluate the collagen deposit in the liver. Immunohistochemical SABC methods were used to detect transplanted BMSCs and expression of urokinase plasminogen activator (uPA).
RESULTS: Serum transaminase level and liver fibrosis in rats were markedly reduced by Guiyuanfang and BMSCs. HA level and procollagen III level were also reduced obviously, compared to model rats (HA: 47.18±10.97 ng/mL, 48.96±14.79 ng/mL; PCIII: 22.48±5.46 ng/mL, 26.90±3.35 ng/mL; P<0.05). Hydroxyproline contents of liver tissue in both BMSCs group and Guiyuanfang group were far lower than that of model group (1227.2±43.1 μg/g liver tissue, 1390.8±156.3 μg/g liver tissue; P<0.01). After treatment fibrosis scores were also reduced. Both Guiyuanfang and BMSCs could increase the expression of uPA. The transplanted BMSCs could engraft, survive, and proliferate in the liver.
CONCLUSION: Guiyuanfang protects against liver fibrosis. Transplanted BMSCs may engraft, survive, and proliferate in the fibrosis livers indefinitely. Guiyuanfang may synergize with BMSCs to improve recovery from liver fibrosis.
Liver fibrosis; Guiyuanfang; Bone marrow stem cells; Transplantation
The technique of stem cells or hepatocytes transplantation has recently improved in order to bridge the time before whole-organ liver transplantation. In the present study, unfractionated bone marrow stem cells (BMSCs) were harvested from the tibial and femoral marrow compartments of male mice, which were cultured in Dulbecco's modified Eagle's medium (DMEM) with and without hepatocyte growth factor (HGF), and then transplanted into Schistosoma mansoni-infected female mice on their 8th week post-infection. Mice were sacrificed monthly until the third month of bone marrow transplantation, serum was collected, and albumin concentration, ALT, AST, and alkaline phosphatase (ALP) activities were assayed. On the other hand, immunohistopathological and immunohistochemical changes of granuloma size and number, collagen content, and cells expressing OV-6 were detected for identification of liver fibrosis. BMSCs were shown to differentiate into hepatocyte-like cells. Serum ALT, AST, and ALP were markedly reduced in the group of mice treated with BMSCs than in the untreated control group. Also, granuloma showed a marked decrease in size and number as compared to the BMSCs untreated group. Collagen content showed marked decrease after the third month of treatment with BMSCs. On the other hand, the expression of OV-6 increased detecting the presence of newly formed hepatocytes after BMSCs treatment. BMSCs with or without HGF infusion significantly enhanced hepatic regeneration in S. mansoni-induced fibrotic liver model and have pathologic and immunohistopathologic therapeutic effects. Also, this new therapeutic trend could generate new hepatocytes to improve the overall liver functions.
Schistosoma mansoni; bone marrow; stem cell; liver; granuloma; collagen; OV-6; liver function
Recent studies indicate that bone marrow stromal cells (BMSCs) derived from patients with multiple myeloma (MM) differ from those of healthy donors in their expression of extracellular matrix compounds and in cytokine production. It is not known whether these abnormalities are primary or are acquired by BMSCs on contact with MM cells.
Materials and Methods:
Interleukin (IL)-6, IL-11, IL-10, and tumor necrosis factor (TNF)-α production by CD166+ mesenchymal BMSCs and the CD38+/CD138+ RPMI8226 myeloma cell line cultivated in vitro in monocultures or co-cultivated under cell-to-cell contact or non-contact conditions in the presence of a tissue culture insert were measured. Intracellular cytokines were measured by flow cytometry analysis as the percentage of cytokine-producing cells or by mean fluorescence intensity as the level of cytokine expression in cells. Additionally, ELISA was used to measure IL-6, soluble IL-6 receptor (sIL-6R), IL-11, IL-10, TNF-α, B-cell-activating factor of the TNF family (BAFF), hepatocyte growth factor (HGF), and osteopontin (OPN) production in the supernatants of the cultures and co-cultures.
A higher ability of the BMSCs of MM patients than in controls was detected to produce IL-6, IL-10, TNF-α, OPN, and especially HGF and BAFF in response to the RPMI8226 cells. Moreover, the BMSCs of the MM patients significantly enhanced the production of sIL-6R by the RPMI8226 cells.
Cytokines over-expressed by BMSCs of MM patients can function as growth factors for myeloma cells (IL-6, IL-10, HGF), migration stimulatory factors for tumor plasma cells (TNF-α, HGF), adhesion stimulatory factors (HGF, BAFF and OPN), stimulators of osteoclastogenesis (IL-6, TNF-α), and angiogenic factors (TNF-α). The results of this experiment strongly suggest that the BMSCs from MM patients differed in spontaneous and myeloma cell-induced production of cytokines, especially of HGF and BAFF, and these abnormalities were both primary and acquired by the BMSCs on contact with the MM cells. This in turn suggests the presence of an undefined, autocrine stimulation pathway resulting in a prolonged production of cytokines even in long-term cultures in vitro and in vivo. These abnormalities might provide optimal conditions for the proliferation and differentiation of residual tumor cells or their precursors in the affected bone marrow.
multiple myeloma; cytokines; bone marrow stromal cells
The recruitment of bone marrow-derived mesenchymal stem cells (BMSCs) to damaged tissues and sites of inflammation is an essential step for clinical therapy. However, the signals regulating the motility of these cells are still not fully understood. Sphingosine-1-phosphate (S1P), a bioactive sphingolipid metabolite, is known to have a variety of biological effects on various cells. Here, we investigated the roles of S1P and S1P receptors (S1PRs) in migration of human BMSCs. We found that S1P exerted a powerful migratory action on human BMSCs. Moreover, by employing RNA interference technology and pharmacological tools, we demonstrated that S1PR1 and S1PR3 are responsible for S1P-induced migration of human BMSCs. In contrast, S1PR2 mediates the inhibition of migration. Additionally, we explored the downstream signaling pathway of the S1P/S1PRs axis and found that activation of S1PR1 or S1PR3 increased migration of human BMSCs through a Gi/extracellular regulated protein kinases 1/2- (ERK1/2-) dependent pathway, whereas activation of S1PR2 decreased migration through the Rho/Rho-associated protein kinase (ROCK) pathway. In conclusion, we reveal that the S1P/S1PRs signaling axis regulates the migration of human BMSCs via a dual-directional mechanism. Thus, selective modulation of S1PR's activity on human BMSCs may provide an effective approach to immunotherapy or tissue regeneration.
Pulmonary fibrosis may result from abnormal alveolar wound repair after injury. Hepatocyte growth factor (HGF) improves alveolar epithelial wound repair in the lung. Stem cells were shown to play a major role in lung injury, repair and fibrosis. We studied the presence, origin and antifibrotic properties of HGF-expressing stem cells in usual interstitial pneumonia.
Immunohistochemistry was performed in lung tissue sections and primary alveolar epithelial cells obtained from patients with usual interstitial pneumonia (UIP, n = 7). Bone marrow derived stromal cells (BMSC) from adult male rats were transfected with HGF, instilled intratracheally into bleomycin injured rat lungs and analyzed 7 and 14 days later.
In UIP, HGF was expressed in specific cells mainly located in fibrotic areas close to the hyperplastic alveolar epithelium. HGF-positive cells showed strong co-staining for the mesenchymal stem cell markers CD44, CD29, CD105 and CD90, indicating stem cell origin. HGF-positive cells also co-stained for CXCR4 (HGF+/CXCR4+) indicating that they originate from the bone marrow. The stem cell characteristics were confirmed in HGF secreting cells isolated from UIP lung biopsies. In vivo experiments showed that HGF-expressing BMSC attenuated bleomycin induced pulmonary fibrosis in the rat, indicating a beneficial role of bone marrow derived, HGF secreting stem cells in lung fibrosis.
HGF-positive stem cells are present in human fibrotic lung tissue (UIP) and originate from the bone marrow. Since HGF-transfected BMSC reduce bleomycin induced lung fibrosis in the bleomycin lung injury and fibrosis model, we assume that HGF-expressing, bone-marrow derived stem cells in UIP have antifibrotic properties.
Hypoxic preconditioning of stem cells and neural progenitor cells has been tested for promoting cell survival after transplantation. The present investigation examined the hypothesis that hypoxic preconditioning of bone marrow mesenchymal stem cells (BMSCs) could not only enhance their survival but also reinforce regenerative properties of these cells. BMSCs from eGFP engineered rats or pre-labeled with BrdU were pre-treated with normoxia (20% O2, N-BMSCs) or sublethal hypoxia (0.5% O2. H-BMSCs). The hypoxia exposure up-regulated HIF-1α and trophic/growth factors in BMSCs, including brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), vascular endothelial growth factor (VEGF) and its receptor FIK-1, erythropoietin (EPO) and its receptor EPOR, stromal derived factor-1 (SDF-1) and its CXC chemokine receptor 4 (CXCR4). Meanwhile, many pro-inflammatory cytokines/chemokines were downregulated in H-BMSCs. N-BMSCs or H-BMSCs were intravenously injected into adult rats 24 hrs after 90-min middle cerebral artery occlusion. Comparing to N-BMSCs, transplantation of H-BMSCs showed greater effect of suppressing microglia activity in the brain. Significantly more NeuN-positive and Glut1-positive cells were seen in the ischemic core and peri-infarct regions of the animals received H-BMSC transplantation than that received N-BMSCs. Some NeuN-positive and Glut-1-positive cells showed eGFP or BrdU immunoflourescent reactivity, suggesting differentiation from exogenous BMSCs into neuronal and vascular endothelial cells. In Rota-rod test performed 15 days after stroke, animals received H-BMSCs showed better locomotion recovery compared with stroke control and N-BMSC groups. We suggest that hypoxic preconditioning of transplanted cells is an effective means of promoting their regenerative capability and therapeutic potential for the treatment of ischemic stroke.
hypoxic preconditioning; bone marrow mesenchymal stem cell; transplantation; angiogenesis; neurogenesis
This study investigated the immune-modulatory effects of human bone marrow-derived mesenchymal stem cells (hBMSCs) on human Th17 cell function through the CD39-mediated adenosine-producing pathway. The suppressive effects of hBMSCs were evaluated by assessing their effects on the proliferation of Th17 cells and the secretion of interferon (IFN)-γ and interleukin (IL)-17A by Th17 cells with or without anti-CD39 treatment. Changes in CD39 and CD73 expression on the T cells with or without co-culture of hBMSCs were evaluated by flow cytometry. hBMSCs effectively suppressed the proliferation of Th17 cells and the secretion of both IL-17A and IFN-γ from Th17 cells using by both flow cytometry and ELISA, while anti-CD39 treatment significantly reduced the inhibitory effects of hBMSCs on the proliferation and secretion of the Th17 cells. The hBMSCs induced increased expression of the CD39 and CD73 on T cells correlated with the suppressive function of hBMSCs, which was accompanied by increased adenosine production. Our data suggests that hBMSCs can effectively suppress immune responses of the Th17 cells via the CD39-CD73-mediated adenosine-producing pathway.
Electronic supplementary material
The online version of this article (doi:10.1007/s11302-013-9385-0) contains supplementary material, which is available to authorized users.
Bone marrow-derived mesenchymal stem cells; Th17 cells; CD39; CD73; Interleukin-17; Interferon-γ; Adenosine
Leukemia is one of the most common malignancies in humans worldwide; however, the molecular mechanism of the effect of bone marrow mesenchymal stem cells (bMSCs) on leukemia cell growth remains unclear. The present study demonstrated that Wnt5a protein expression was significantly induced in bMSCs via an adenovirus vector (P<0.01). The results showed that the proliferation of HL60 cells, a leukemia cell line, was significantly inhibited when the cells were stimulated with the culture supernatant of adeno-Wnt5a bMSCs compared with the culture supernatants of bMSCs and adeno-vector bMSCs for 24 or 48 h (P<0.01). The promoted maturation levels of HL60 cells were also observed following stimulation with the culture supernatant of adeno-Wnt5a bMSCs (P<0.01). However, no significant difference was identified in the proliferation and maturation of HL60 cells among the three groups stimulated with the culture supernatants containing a neutralization antibody against Wnt5a. Furthermore, the bMSC-derived Wnt5a was found to influence the maturation and proliferation of the HL60 cells by enhancing the non-canonical Wnt signaling pathway, while inhibiting the canonical Wnt signaling pathway by upregulating the expression of receptor tyrosine kinase-like orphan receptor 2 and calcium/calmodulin-dependent protein kinase II, and suppressing the expression of β-catenin and cyclin D1. In conclusion, bMSC-derived Wnt5a modifies the proliferation and maturation of HL60 cells via activation of the non-canonical Wnt signaling pathway.
bone marrow mesenchymal stem cell; HL60 cell line; leukemia; Wnt5a; Wnt signaling pathway
Objective. This study is to investigate the effects of bone marrow mesenchymal stem cell (BMSC) transplantation on acute liver failure (ALF). Methods. BMSCs were separated from rat bone marrow, cultured, and identified by flow cytometry. Rat model with ALF was established by injecting D-galactosamine and lipopolysaccharide. Rats were randomly divided into the control group and BMSC transplantation group. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured at 24 h, 120 h, and 168 h after BMSC transplantation. Apoptosis was detected by TUNEL assay. The expression of VEGF and AFP proteins was detected by immunofluorescence. Caspase-1 and IL-18 proteins and mRNA were detected by immunohistochemistry and RT-PCR. Results. Compared with the control group, levels of ALT, AST, caspase-1 and IL-18 proteins, and mRNA in the transplantation group were significantly lower at 120 h and 168 h after BMSCs transplantation. Apoptosis was inhibited by BMSCs transplantation. The VEGF protein levels were increased with the improvement of liver function, and the AFP protein levels were increased with the deterioration of the liver function after BMSCs transplantation. Conclusions. BMSCs transplantation can improve liver function and inhibit hepatocyte apoptosis as well as promote hepatocyte proliferation in rat model with ALF.
Bone marrow mesenchymal stem cells (BMSCs) are capable of homing to and repair damaged myocardial tissues. Apoptosis of BMSCs in response to various pathological stimuli leads to the attenuation of healing ability of BMSCs. Plenty of evidence has shown that elevated homocysteine level is a novel independent risk factor of cardiovascular diseases. The present study was aimed to investigate whether homocysteine may induce apoptosis of BMSCs and its underlying mechanisms. Here we uncovered that homocysteine significantly inhibited the cellular viability of BMSCs. Furthermore, TUNEL, AO/EB, Hoechst 333342 and Live/Death staining demonstrated the apoptotic morphological appearance of BMSCs after homocysteine treatment. A distinct increase of ROS level was also observed in homocysteine-treated BMSCs. The blockage of ROS by DMTU and NAC prevented the apoptosis of BMSCs induced by homocysteine, indicating ROS was involved in the apoptosis of BMSCs. Moreover, homocysteine also caused the depolarization of mitochondrial membrane potential of BMSCs. Furthermore, apoptotic appearance and mitochondrial membrane potential depolarization in homocysteine-treated BMSCs was significantly reversed by JNK inhibitor but not p38 MAPK and ERK inhibitors. Western blot also confirmed that p-JNK was significantly activated after exposing BMSCs to homocysteine. Homocysteine treatment caused a significant reduction of BMSCs-secreted VEGF and IGF-1 in the culture medium. Collectively, elevated homocysteine induced the apoptosis of BMSCs via ROS-induced the activation of JNK signal, which provides more insight into the molecular mechanisms of hyperhomocysteinemia-related cardiovascular diseases.
Bone marrow stem cells (BMSCs) have been shown to improve neurological function recovery in cerebral ischemia. Hypoxia-inducible factor-1 (HIF-1) α-AA is a more stable mutant form of HIF-1α, which is a crucial oxygen-sensitive regulator. To investigate the protective effects of HIF-1α-AA-modified BMSCs on neuron survival in cerebral ischemia models, we co-cultured HIF-1α-AA-modified BMSCs with neuron-like cells (PC12 cells) and observed a significant increase in the release of vascular endothelial growth factor (VEGF) from BMSCs, the decreased PC12 cell apoptosis, and the upregulation of Survivin expression reduced by hypoxia in PC12 cells compared to enhanced green fluorescent protein (EGFP) BMSCs. In addition, to explore whether VEGF secreted by HIF-1α-AA-modified BMSCs plays an important role in preventing hypoxia-induced apoptosis and the possible mechanism involved, exogenous VEGF were applied and the similar protective effects on PC12 cells were observed in vitro. Furthermore, hypoxia reduced the expression of phosphorylated Akt and phosphorylated FoxO1, whereas the administration of VEGF reversed these changes. Transfection of FoxO1 H215R, a DNA-binding mutant, abrogated the inhibitory ability on Survivin promoter activity, whereas FoxO1 AAA, the active form of FoxO1, presented further repression on Survivin promoter, indicating that FoxO1 directly binds on Survivin promoter as a transcriptional repressor and that phosphorylation status of FoxO1 affects its inhibition on the Survivin promoter. Transplantation of HIF-1α-AA-modified BMSCs after cerebral ischemia in vivo sufficiently reduced neurons apoptosis, decreased cerebral infarction volume, and induced a significant improvement on the modified neurological severity score compared to the EGFP BMSCs group. In conclusion, HIF-1α-AA-modified MSCs showed an obvious protective effect on neuron-like cells or neuron after ischemia in vitro and in vivo, at least in part, through the VEGF/PI3K/Akt/FoxO1 pathway.
At present, due to the growing attention focused on the issue of tendon–bone healing, we carried out an animal study of the use of genetic intervention combined with cell transplantation for the promotion of this process. Here, the efficacy of bone marrow stromal cells infected with bone morphogenetic protein-2 (BMP-2) on tendon–bone healing was determined. A eukaryotic expression vector containing the BMP-2 gene was constructed and bone marrow-derived mesenchymal stem cells (bMSCs) were infected with a lentivirus. Next, we examined the viability of the infected cells and the mRNA and protein levels of BMP-2-infected bMSCs. Gastrocnemius tendons, gastrocnemius tendons wrapped by bMSCs infected with the control virus (bMSCs+Lv-Control), and gastrocnemius tendons wrapped by bMSCs infected with the recombinant BMP-2 virus (bMSCs+Lv-BMP-2) were used to reconstruct the anterior cruciate ligament (ACL) in New Zealand white rabbits. Specimens from each group were harvested four and eight weeks postoperatively and evaluated using biomechanical and histological methods. The bMSCs were infected with the lentivirus at an efficiency close to 100%. The BMP-2 mRNA and protein levels in bMSCs were significantly increased after lentiviral infection. The bMSCs and BMP-2-infected bMSCs on the gastrocnemius tendon improved the biomechanical properties of the graft in the bone tunnel; specifically, bMSCs infected with BMP-2 had a positive effect on tendon–bone healing. In the four-week and eight-week groups, bMSCs+Lv-BMP-2 group exhibited significantly higher maximum loads of 29.3 ± 7.4 N and 45.5 ± 11.9 N, respectively, compared with the control group (19.9 ± 6.4 N and 21.9 ± 4.9 N) (P = 0.041 and P = 0.001, respectively). In the eight-week groups, the stiffness of the bMSCs+Lv-BMP-2 group (32.5 ± 7.3) was significantly higher than that of the bMSCs+Lv-Control group (22.8 ± 7.4) or control groups (12.4 ± 6.0) (p = 0.036 and 0.001, respectively). Based on the histological findings, there was an increased amount of perpendicular collagen fibers formed between the tendon and bone in the bMSCs+Lv-Control and bMSCs+Lv-BMP-2 group, compared with the gastrocnemius tendons. The proliferation of cartilage-like cells and the formation of fibrocartilage-like tissue were highest within the bone tunnels in the bMSCs+Lv-BMP-2 group. These results suggest that this lentivirus can be used to efficiently infect bMSCs with BMP-2. Furthermore, tendons wrapped by bMSCs+Lv-BMP-2 improved tendon–bone healing.
tendon-bone healing; anterior cruciate ligament (ACL); reconstruction; bone marrow-derived mesenchymal stem cells
Bone marrow mesenchymal stem cells (BMSC) can differentiate into diverse cell types, including adipogenic, osteogenic, chondrogenic and myogenic lineages. There are lots of BMSC accumulated in atherosclerosis vessels and differentiate into VSMC. However, it is unclear whether VSMC originated from BMSC (BMSC-SMC) could remodel the vessel in new tunica intima or promote the pathogenesis of atherosclerosis. In this study, BMSC were differentiated into VSMC in response to the transforming growth factor β (TGF-β) and shown to express a number of VSMC markers, such as α-smooth muscle actin (α-SMA) and smooth muscle myosin heavy chain1 (SM-MHC1). BMSC-SMC became foam cells after treatment with 80 mg/L ox-LDL for 72 hours. Ox-LDL could upregulate scavenger receptor class A (SR-A) but downregulate the ATP-binding cassette transporter A1 (ABCA1) and caveolin-1 protein expression, suggesting that modulating relative protein activity contributes to smooth muscle foam cell formation in BMSC-SMC. Furthermore, we found that BMSC-SMC have some biological characteristics that are similar to VSMC, such as the ability of proliferation and secretion of extracellular matrix, but, at the same time, retain some biological characteristics of BMSC, such as a high level of migration. These results suggest that BMSC-SMC could be induced to foam cells and be involved in the development of atherosclerosis.
Bone marrow mesenchymal stem cells; vascular smooth muscle cells; atherosclerosis; SR-A; ABCA1; caveolin-1