Effects Of Bone Marrow Mesenchymal Stem Cells Research Articles

Androgen attenuates antitumor effects of gastric cancer cells by bone marrow mesenchymal stem cells via restricting the JNK signaling activation

Background: Researches on bone marrow mesenchymal stem cells (BMMSCs) have generated controversial results in tumor research. In the present study, we aimed to explore the functions of BMMSCs on gastric cancer and the possible mechanism in a mimicking microenvironment of the stomach. Methods: Transwell co-cultured system was used to co-culture BMMSCs and gastric cancer SGC-7901 cells. In some experiments, androgen and its antagonist were added into the cells as required. Cell viability, cell apoptosis, mRNA and protein expressions of apoptosis- and JNK signaling- associated genes were respectively determined by performing cell counting kit-8, flow cytometry, quantitative real-time PCR and western blot. Results: Androgen contributed to the growth of BMMSCs and SGC-7901 cells. In co-cultured system, BMMSCs not only suppressed SGC-7901 cell viability, induced cell apoptosis and promoted tumor necrosis factor (TNF)-α release, but also regulated the level of Bax/Bcl-2 and elevated the expressions of phosphorylation (p)-JNK and p53. After adding androgens, the anti-tumor effects of BMMSCs were weakened. Meanwhile, the antagonists of androgens could partially recover BMMSCs in vitro inhibitory effects on gastric cancer cells by activation of JNK signaling. Conclusions: This study demonstrated the important roles of BMMSCs on the growth and apoptosis of gastric cancer cells in vitro . Additionally, in the mimicking microenvironment of the stomach, androgen weakened the antitumor effects of BMMSCs by limiting JNK signaling activation, suggesting that androgen antagonist may be a promising adjuvant drug to BMMSCs in gastric cancer therapy.

Bone marrow mesenchymal stem cells attenuate the progression of focal segmental glomerulosclerosis in rat models

BackgroundFocal segmental glomerulosclerosis (FSGS) is the most common glomerular etiology of end-stage kidney disease (ESKD). Increasing evidence has indicated the reparative potential of mesenchymal stem cells (MSCs) in damaged diseased kidneys. However, the effect of bone marrow mesenchymal stem cells (BMSCs) on the FSGS progression remains unclear. This study aimed to investigate the protective effects of BMSCs on FSGS progression.MethodsA rat model of FSGS was generated via unilateral nephrectomy plus adriamycin injection. Rat BMSCs were isolated and characterized on the basis of their differentiative potential towards adipocytes and osteoblasts and via flow cytometry analysis. Thereafter, rat BMSCs were transplanted into FSGS recipients through the caudal vein. After 8 weeks, 24-h proteinuria, serum creatinine, and urea nitrogen levels were determined. Renal morphology was assessed using a light and transmission electron microscope. MMP9 and TIMP-1 positive cells were detected via immunohistochemical analysis. Expression levels of proinflammatory cytokines IL-6 and TNF-α were examined via RT-PCR.ResultsThe isolated adherent cells from the bone marrow of rats were phenotypically and functionally equivalent to typical MSCs. Clinical examination revealed that BMSC transplantation reduced the 24-h urinary protein excretion, and serum creatinine and urea nitrogen levels. Renal morphology was ameliorated in BMSCs-transplanted rats. Mechanistically, BMSC transplantation significantly downregulated TIMP-1 and upregulated MMP9, thereby increasing the renal MMP9/TIMP-1 ratio. Moreover, BMSC transplantation also downregulated IL-6 and TNF-α.ConclusionsBMSC transplantation can attenuate FSGS progression in a rat model of FSGS, thereby providing a theoretical foundation for the application of autologous BMSCs in clinical FSGS therapy.

Effect of Mesenchymal Stem Cells and Chicken Embryo Extract on Flap Viability and Mast Cells in Rat Skin Flaps

ABSTRACTStudy Objective: We investigated the effect of bone marrow mesenchymal stem cells (BMMSCs) and chicken embryo extract (CEE), alone and in combination, on tissue viability of skin flaps, and mast cells (MCs), in an experimental random skin flap (RSF) rat model. Materials and Methods: A 30 mm × 80 mm RSF was made on the dorsum of each of the forty rats, which were then divided into four groups. One group did not receive any treatment and served as the control, the second group received BMMSCs, the third group received CEE + BMMSCs, and the fourth group received CEE. For BMMSC treatment, 6 × 109 BMMSCs were injected into twelve separate injection sites of each flap. Seven days after RSF surgery, the remaining viable part of each flap was measured and examined to determine the number of blood vessels, MCs, and degranulated MCs. Results: The CEE, CEE + BMMSC, and BMMSC groups displayed significantly higher levels of flap viability (ANOVA test: p = 0.000; LSD test for all groups: p = 0.000), and a greater number of vessels (ANOVA test: p = 0.000; LSD test: p = 0.000, 0.002, and 0.012, respectively), compared with the control group. The flap viability was poorer in the BMMSC group than in the CEE and CEE + BMMSC groups. The BMMSC group also had a greater number of degranulated and total MCs, compared with the CEE and CEE + BMMSC groups. Conclusions: We observed biostimulatory effects of BMMSCs, CEE, and CEE + BMMSCs on flap viability and vessel numbers, compared to the control group. MCs produced in response to BMMSC treatment have an inhibitory effect on the RSFs survival in an ischemic tissue model.

Impact of bone marrow mesenchymal stem cell immunomodulation on the osteogenic effects of laponite

BackgroundWith the development of osteoimmunology and bone tissue engineering (BTE), it has been recognized that the immunomodulatory properties of bone biomaterials have considerable impact in determining their fate after implantation. In this regard, the polarization of macrophages secondary to biomaterials is postulated to play a crucial role in modulating their osteogenesis; thus, strategies that may facilitate this process engender increasing levels of attention. Whereas a variety of reports highlight the immunomodulation of bone marrow mesenchymal stem cells (BMSCs) in cell therapy or their osteogenesis in BTE, few have focused on the effect of BMSCs in promoting osteogenesis in BTE through regulating the phenotype of macrophages. Accordingly, there is an urgent need to clarify the immunomodulatory properties of agents such as laponite (Lap), which is comprised of bioactive silicate nanoplatelets with excellent osteogenesis-inducing potential, to enhance their use in BTE.MethodsIn the present study, we analyzed the osteoimmunomodulatory properties of Lap alone, as well as following the introduction of BMSCs into Lap, to determine whether BMSCs could modulate its immunomodulatory properties and promote osteogenesis.ResultsIt was found that the BMSCs reversed the polarization of murine-derived macrophage RAW 264.7 cells from M1 as induced by pure Lap to M2 and promoted osteogenesis. In vivo study confirmed that BMSCs combined with Lap initiated a less severe immune response and had an improved effect on bone regeneration compared with Lap alone, which corresponded with the in vitro evaluation.ConclusionThese results suggest that BMSCs could ameliorate the inflammation induced by Lap and enhance its bone formation. The immunomodulatory characteristics of BMSCs suggest that these might be tailored as a new strategy to promote the osteogenic capacity of biomaterials.

Bone marrow mesenchymal stem cells promote head and neck cancer progression through Periostin-mediated phosphoinositide 3-kinase/Akt/mammalian target of rapamycin.

Bone marrow mesenchymal stem cells (BMMSC) have been shown to be recruited to the tumor microenvironment and exert a tumor‐promoting effect in a variety of cancers. However, the molecular mechanisms related to the tumor‐promoting effect of BMMSC on head and neck cancer (HNC) are not clear. In this study, we investigated Periostin (POSTN) and its roles in the tumor‐promoting effect of BMMSC on HNC. In vitro analysis of HNC cells cultured in BMMSC‐conditioned media (MSC‐CM) showed that MSC‐CM significantly promoted cancer progression by enhancing cell proliferation, migration, epithelial‐mesenchymal transformation (EMT), and altering expression of cell cycle regulatory proteins and inhibition of apoptosis. Moreover, MSC‐CM promoted the expression of POSTN and POSTN promoted HNC progression through the activation of the phosphoinositide 3‐kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway. In a murine model of HNC, we found that BMMSC promoted tumor growth, invasion, metastasis and enhanced the expression of POSTN and EMT in tumor tissues. Clinical sample analysis further confirmed that the expression of POSTN and N‐cadherin were correlated with pathological grade and lymph node metastasis of HNC. In conclusion, this study indicated that BMMSC promoted proliferation, invasion, survival, tumorigenicity and migration of head and neck cancer through POSTN‐mediated PI3K/Akt/mTOR activation.

Mesenchymal Stem Cells in Rat Hepatic Fibrosis MModel: Benefits? Mechanism of Action?: 2017 Presidential Poster Award

Introduction: Hepatic fibrosis may evolve to liver cirrhosis which may ultimately develop into hepatocellular carcinoma. Mesenchymal stem cells (MSCs) have potential to trans-differentiate into hepatic cells and thus may be a curative option in liver cirrhosis. Natural killer (NK) cells are a component of the innate immune system that destroy compromised host cells and have critical antifibrotic role. Aim: To show the effects of bone marrow MSCs transferred via the tail vein to the rats having hepatic fibrosis produced by common bile duct ligation (CBDL) with a special focus on the changes of the NK population distribution. Methods: Rats were divided into three groups; 1- CBDL rats that were injected with phosphate-buffered saline (PBS), 2- CBDL rats injected with MSCs, 3- healthy rats that were sham operated and given MSCs. All rats were sacrificed at the end of the experiment. We analyzed the in vivo functional outcomes by measuring the serum glucose, bilirubin and ALT levels. Splenocytes isolated from the collected spleens were cultured and the supernatants were analyzed for IL (interleukin)-1α, TNF (tumor necrosis factor)-α, IFN (interferon)-γ and IL-10 using flow cytometry. Results: Liver fibrosis developed in CBDL rats while the healthy rats did not show any alteration in liver architecture. Although healthy group had significantly lower serum bilirubin, ALT and glucose levels than CBDL rats, the difference regarding those parameters did not differ between groups 1 and 2. T-lymphocyte proliferation was significantly suppressed in group 2 compared to group 1. IL-1α, TNF-α and IFN-γ levels in supernatants of cultured lymphocytes in group 2 were significantly higher than group 3 while they tended to be lower than group 1. NK and Treg cells in peripheral blood significantly increased in group 2 compared to group 1. Histologically, hepatic fibrosis scores were significantly alleviated in group 2 compared to group 1 (p=0.039). NK cells in the general hepatic parenchyma and in the portal areas were both increased significantly in group 2 compared to group 1. Conclusion: Our findings suggest bone marrow derived MSCs may be beneficial in alleviating the hepatic fibrosis by suppressing the T cell proliferation and the proinflammatory cytokines and inducing NK cell recruitment to liver parenchyma in rats. Thus, MSC treatment may appear promising in liver injury and future clinical therapies are warranted. Immunophenotyping of leukocytes. CD3+CD4+ T lymphocyte, CD3+CD8+ Cytotoxic T cell, CD4+CD25+ T regulatory cell and CD161a NK cell in all groups by flow cytometry. (B) CD3+CD4+ % T lymphocyte, CD3+CD8+ % Cytotoxic T cell, CD4+CD25+ %T regulatory cell and CD161a NK cells were displayed statistically in all groups..*P < 0.05, **P < 0.01.Figure

Neuroprotective effects of BDNF and GDNF in intravitreally transplanted mesenchymal stem cells after optic nerve crush in mice

To assess the neuro-protective effect of bone marrow mesenchymal stem cells (BMSCs) on retinal ganglion cells (RGCs) following optic nerve crush in mice. C56BL/6J mice were treated with intravitreal injection of PBS, BMSCs, BDNF-interference BMSCs (BIM), and GDNF-interference BMSCs (GIM) following optic nerve crush, respectively. The number of surviving RGCs was determined by whole-mount retinas and frozen sections, while certain mRNA or protein was detected by q-PCR or ELISA, respectively. The density (cell number/mm2) of RGCs was 410.77±56.70 in the retina 21d after optic nerve crush without any treatment, compared to 1351.39±195.97 in the normal control (P<0.05). RGCs in BMSCs treated eyes was 625.07±89.64/mm2, significantly higher than that of no or PBS treatment (P<0.05). While RGCs was even less in the retina with intravitreal injection of BIM (354.07+39.77) and GIM (326.67+33.37) than that without treatment (P<0.05). BMSCs injection improved the internal BDNF expression in retinas. Optic nerve crush caused rust loss of RGCs and intravitreally transplanted BMSCs at some extent protected RGCs from death. The effect of BMSCs and level of BDNF in retinas are both related to BDNF and GDNF expression in BMSCs.

Secretome of human bone marrow mesenchymal stem cells: an emerging player in lung cancer progression and mechanisms of translation initiation.

Non-small cell lung cancer (NSCLC) remains the most common cause of cancer-related death worldwide. Patients presenting with advanced-stage NSCLC have poor prognosis, while metastatic spread accounts for >70% of patient's deaths. The major advances in the treatment of lung cancer have brought only minor improvements in survival; therefore, novel strategic treatment approaches are urgently needed. Accumulating data allocate a central role for the cancer microenvironment including mesenchymal stem cells (MSCs) in acquisition of drug resistance and disease relapse. Furthermore, studies indicate that translation initiation factors are over expressed in NSCLC and negatively impact its prognosis. Importantly, translation initiation is highly modulated by microenvironmental cues. Therefore, we decided to examine the effect of bone marrow MSCs (BM-MSCs) from normal donors on NSCLC cell lines with special emphasis on translation initiation mechanism in the crosstalk. We cultured NSCLC cell lines with BM-MSC conditioned media (i.e., secretome) and showed deleterious effects on the cells' proliferation, viability, death, and migration. We also demonstrated reduced levels of translation initiation factors implicated in cancer progression [eukaryotic translation initiation factor 4E (eIF4E) and eukaryotic translation initiation factor 4GI (eIF4GI)], their targets, and regulators. Finally, we outlined a mechanism by which BM-MSCs' secretome affected NSCLC's mitogen-activated protein kinase (MAPK) signaling pathway, downregulated the cell migration, and diminished translation initiation factors' levels. Taken together, our study demonstrates that there is direct dialogue between the BM-MSCs' secretome and NSCLC cells that manipulates translation initiation and critically affects cell fate. We suggest that therapeutic approach that will sabotage this dialogue, especially in the BM microenvironment, may diminish lung cancer metastatic spread and morbidity and improve the patient's life quality.

Effect of hypoxic preconditioning on anti-inflammatory responses of bone marrow mesenchymal stem cells in rats: in vitro and in vivo experiments

Objective To investigate the effect of hypoxic preconditioning on anti-inflammatory responses of bone marrow mesenchymal stem cells (BMSCs) in rats through in vitro and in vivo experiments.Methods In vitro experiment The isolated rat BMSCs were cultured by whole bone marrow adherence method.The cells at passage 3 were seeded in 24-well plates at a density of 1 × 106 cells/ml and randomly divided into 5 groups (n =8 wells each) using a random number table:control group (group C),normoxia-incubated group (group N),hypoxic preconditioning group (group H),hypoxia preconditioning + STAT3 inhibitor Stattic group (group HS) and hypoxia preconditioning + anti-IL-10 monoclonal antibody group (group HA).In group C,BMSCs were incubated in DMEM culture medium.In group N,BMSCs were exposed to21％ O2-74％ N2-5.0％ CO2 for48 h.In group H,BMSCs were exposed to 0.5％ O2-94.5％ N2-5.0％ CO2 for 24 h followed by 24 h exposure to normoxia.In HS and HA groups,500 μg/ml Stattic and 100 μg/rnl anti-IL-10 monoclonal antibody were added to the culture medium before hypoxia preconditioning,respectively.The expression of phosphorylated STAT3 (p-STAT3) and IL-10 was determined by Western blot.In vivo experiment Healthy male Sprague-Dawley rats,weighing 300-350 g,in which intrathecal catheters were successfully implanted without complications,underwent spinal cord ischemia by occlusion of the thoracic aorta combined with controlled hypotension.Three hundred rats with spinal cord I/R injury were randomly divided into C,N,H,HS and HA groups (n =60 each) using a random number table.Immediately after onset of reperfusion,DMEM medium 300 μl was injected intrathecally in group C,and BMSC suspension 300 μl (1 × 106 cells/ml) was injected intrathecally in N,H,HS and HA groups.Neurological function was scored before ischemia and at 4,12,24 and 48 h of reperfusion (T0-,).The animals were then sacrificed and the lumbar segment of spinal cord was removed for detection of the content of IL-10,TNF-α,IL-1β,IL-6,monocyte chemotactic protein-1 (MCP-1),and macrophage inflammatory protein-1 α (MIP-1 α) (by ELISA) and the number of activated microglia (by immuno-histochemistry).Results Compared with C and N groups,the expression of pSTATβ and IL-10 was significantly up-regulated,the neurological function score and IL-10 content were increased,the content of TNF-α,IL-1β,IL-6,MCP-1 and MIP-1α and the number of activated microglia were decreased in group H (P ＜ 0.05).Compared with group H,the expression of p-STAT3 and IL-10 in group HS and expression of IL-10 in group HA was significantly down-regulated,and the neurological function score and IL-10 content were decreased,and the content of TNF-α,IL-13,IL-6,MCP-1 and MIP-1α and the number of activated microglia were increased in HS and HA groups (P ＜ 0.05).Conclusion Hypoxic preconditioning can enhance anti-inflammatory effects of BMSCs,thus increasing BMSCs-induced reduction of spinal cord ischemia-reperfusion injury in rats. Key words: Cell hypoxia; Ischemica preconditioning; Mesenchymal stem cells transplantation ; Spinal cord ; Inflammation

Long-term research of stem cells in monocrotaline-induced pulmonary arterial hypertension

Our previous studies have shown that bone marrow mesenchymal stem cells (BMSCs) can inhibit the progression of pulmonary artery hypertension (PAH) in the monocrotaline (MCT) model in the short term. The aim of this study was to further investigate the long-term effect of BMSCs on PAH and to explore the mechanism of the protective effect including the pulmonary vascular remodeling and cell differentiation. PAH model was established by subcutaneous injection of 50 mg/kg MCT as previously study. Postoperatively, the animals were randomly divided into three groups (n = 10 in each group): control, PAH group, and BMSCs implantation group. Six months after injection, immunology and immunohistochemistry analysis indicated the MCT-induced intima-media thickness in muscular arteries was reduced (P < 0.05); the area of collagen fibers in lung tissue was lower (P < 0.05), and the proliferating cell nuclear antigen level in pulmonary artery smooth muscle cells was decreased (P < 0.05). Immunofluorescence showed that the cells have the ability to differentiate between von Willebrand factor and vascular endothelial growth factor. Six months after intravenous injection, BMSCs could significantly improve pulmonary function by inhibiting the ventricular remodeling and the effect of cell differentiation.

Hypoxia preconditioned bone marrow mesenchymal stem cells promote liver regeneration in a rat massive hepatectomy model

IntroductionBone marrow mesenchymal stem cells (BMMSCs) have been reported to facilitate liver regeneration after toxic injuries. However, the effect of BMMSCs on liver regeneration after massive hepatectomy is barely studied. Here we explored whether infusion of BMMSCs promotes liver regeneration in a rat massive hepatectomy model.MethodsHypoxia preconditioning was achieved by culturing BMMSCs under a hypoxia environment. Then 85% hepatectomy was performed and hypoxia or normoxia preconditioned BMMSCs were infused into the portal vein. A group of rats received vascular endothelial growth factor (VEGF) neutralizing antibody perioperatively, and underwent 85% hepatectomy and a subsequent infusion of hypoxia preconditioned BMMSCs to verify the role of VEGF in the effects of BMMSCs on liver regeneration. Liver samples were collected and liver regeneration was evaluated postoperatively.ResultsHypoxia preconditioning enhanced the expression of VEGF in BMMSCs in vitro. Infusion of BMMSCs promoted proliferation of hepatocytes, reflected by elevated cyclin D1 expression and proliferating cell nuclear antigen-positive hepatocytes. However, BMMSC infusion did not improve the serum albumin level, liver weight/body weight ratio, and survival after operation. Infusion of hypoxia preconditioned BMMSCs significantly elevated cyclin D1, proliferating cell nuclear antigen-positive hepatocytes, liver weight/body weight ratio, and survival compared with normoxia preconditioned BMMSCs, accompanied by an increased serum albumin level. The level of VEGF in liver homogenate was much higher in hypoxia preconditioned BMMSC-treated animals than in other groups. In addition, the perioperative injection of VEGF neutralizing antibody significantly blocked the therapeutic effects of hypoxia preconditioned BMMSCs on liver injury and regeneration in this model.ConclusionHypoxia preconditioned BMMSCs enhanced liver regeneration after massive hepatectomy in rats, possibly by upregulating the level of VEGF.

Effect of bone marrow mesenchymal stem cells from blastic phase chronic myelogenous leukemia on the growth and apoptosis of leukemia cells

Chronic myelogenous leukemia (CML) has a typical progressive course with transition from a chronic phase to a terminal blast crisis phase. However, the mechanisms that lead to disease progression remain unclear. Bone marrow mesenchymal stem cells (BMMSCs) play important roles in maintaining the bone marrow microenvironment. In the present study, the biological characteristics of BMMSCs were determined including proliferation, apoptosis and secretion of cytokines during blastic phase CML (CML-Bp). The effect of BMMSCs in CML-Bp on K562 human CML cells and the CML-Bp original generation leukemia cells were also explored. Our results showed that CML-Bp BMMSCs protect tumor cells and increase their anti-apoptotic ability through regulating the expression of apoptosis-related proteins and activating the Wnt pathway.

BMSCs reduce rat granulosa cell apoptosis induced by cisplatin and perimenopause

BackgroundThe objective of this study was to evaluate the effect of bone marrow mesenchymal stem cells (BMSCs) on the apoptosis of granulosa cells (GCs) in rats.BMSCs and GCs were isolated from rats. GCs were separated into one of the following three groups: an untreated control group (control), a cisplatin (5 mg/L) treatment group (cisplatin), and group co-cultured with BMSCs and treated with cisplatin (BMSC). GC apoptosis was analyzed by annexin V staining and real-time PCR analysis for apoptosis-related genes. The effect of BMSCs was also determined in 9 to 10 month-old perimenopausal rats that were separated into the following groups: saline control, BMSC transplantation (1–2 × 106 cells), and estrogen treatment (0.158 mg/kg/d) groups. A young group consisting of 3 to 4 month-old rats that were treated with saline was also evaluated as a control. After 1 and 3 months, GC apoptosis was evaluated by TUNEL analysis.ResultsCisplatin increased GC apoptosis from 0.59% to 13.04% in the control and cisplatin treatment groups, respectively, which was significantly reduced upon co-culture with BMSCs to 4.84%. Cisplatin treatment increased p21 and bax and decreased c-myc mRNA expression, which was reversed upon co-culture with BMSCs. As compared to young rats, increased apoptosis was observed in the perimenopausal rats (P < 0.001). After 3 months, the apoptosis rate in the BMSC group was significantly lower than that of the control group (P = 0.007).ConclusionsBMSC therapy may protect against GC apoptosis induced by cisplatin and perimenopause. Further studies are necessary to evaluate therapeutic efficacy of BMSCs.

Comparative Effects of Bone Marrow Mesenchymal Stem Cells on Lipopolysaccharide-Induced Microglial Activation

After injury to the CNS, microglia are rapidly activated and concentrated and trigger inflammatory reaction at the sites of injury. Bone marrow mesenchymal stem cells (BMMSC) represent attractive cell sources for treating CNS injury. Although anti-inflammatory and paracrine effects of grafted BMMSC have been shown, direct modulation of BMMSC on microglia in situ remains unclear. The present work employs in vitro transwell assay to characterize the effects of BMMSC on LPS-stimulated microglia. BMMSC are cultivated in serum and serum-free (sf) conditions, namely, BMMSC and BMMSC-sf. Both cultures express major surface markers specific for mesenchymal stem cells. However, the BMMSC-sf exhibit sphere-like structure with reduced expression of two adherent cell markers, CD29 and CD90. Compared to BMMSC-sf, BMMSC are fibroblast like and have faster differentiation potential into neural-like cells. Furthermore, BMMSC release significant levels of TIMP-1 and VEGF, regardless of being alone or in coculture. The downregulated MMP-9 mRNA may be caused by TIMP-1 secretion from BMMSC. Our cell culture system provides a powerful tool for investigating the molecular and cellular changes in microglia-BMMSC cocultures.

Effects of simvastatin on the osteogenic differentiation and immunomodulation of bone marrow mesenchymal stem cells.

The present study aimed to investigate the effects of simvastatin on the bone differentiation capacity and immunological characteristics of bone marrow mesenchymal stem cells (BMSCs). BMSCs were isolated and cultured in medium containing 1.0µmol/mlsimvastatin. The alkaline phosphatase activity, mRNA expression levels of osteocalcin and bone sialoprotein, and calcium nodule formation were assessed to determine the osteogenic differentiation capability of BMSCs. To investigate alterations in the immunological properties of simvastation‑treated BMSCs, the immunogenicity of these cells and the effect of BMSCs on phytohemagglutinin‑stimulated lymphocyte proliferation were also assessed. Following treatment with simvastatin, the alkaline phosphatase activity, and mRNA expression levels of osteocalcin and bone sialoprotein were increased significantly in the BMSCs. In addition, von Kossa staining revealed a brown calcium‑positive reaction zone in simvastatin‑treated cells. Simvastatin‑induced BMSCs revealed no affect on the proliferation of allogeneic lymphocytes, however, inhibited phytohemagglutinin‑induced lymphocyte proliferation. Collectively, simvastatin promoted the osteogenic differentiation of BMSCs significantly without affecting their immunosuppressive properties.

Transplantation of bone marrow mesenchymal stem cells reduces lesion volume and induces axonal regrowth of injured spinal cord

It has been demonstrated that transplantation of bone marrow mesenchymal stem cells (BMSCs) improves recovery of injured spinal cord in animal models. However, the mechanism of how BMSCs promote repair of injured spinal cord remains under investigation. The present study investigated the neural differentiation of BMSCs, the lesion volume and axonal regrowth of injured spinal cord after transplantation. Seven days after spinal cord injury, 3 x 10(5) BMSCs or PBS (control) was delivered into the injury epicenter of the spinal cord. At 8 weeks after spinal cord injury, transplantation of BMSCs reduced the volume of cavity and increased spared white matter as compared to the control. BMSCs did not express the cell marker of neurons, astrocytes and oligodendrocytes in injured spinal cord. Transmission electron microscopic examination displayed an increase in the number of axons in BMSC rats. The effect of BMSCs on growth of neuronal process was further investigated by using a coculture system. The length and the number of neurites from spinal neurons significantly increased when they cocultured with BMSCs. PCR and immunochemical analysis showed that BMSCs expressed brain-derived neurotrophic factor (BDNF) and glia cell line-derived neurotrophic factor (GDNF). These findings demonstrate that transplantation of BMSCs reduces lesion volume and promotes axonal regrowth of injured spinal cord.

Mesenchymal Stem Cells Inhibit Dendritic Cell Differentiation and Function by Preventing Entry Into the Cell Cycle

Mesenchymal stem cells (MSCs) play a crucial role in hematopoietic development and have been shown to exert a powerful immunosuppressive effect. In this study, we investigated the effect of bone marrow MSC on the differentiation and function of peripheral blood monocytes into dendritic cells (DCs). Human MSCs, generated from normal bone marrow, were added to peripheral blood monocytes stimulated in vitro with granulocyte-macrophage colony stimulating factor and interleukin-4 to become DCs. Monocytes were then examined for the expression of markers characteristic of DCs and their ability to stimulate allogeneic T cells. In addition, the effect of MSCs on the cell cycle of monocyte-derived DCs and the expression of various cell cycle proteins were analyzed by cytometric analysis and Western blotting with specific antibodies. MSCs blocked the differentiation of monocytes into DCs and impaired their antigen-presenting ability. This resulted from a block of monocytes from entering the G1 phase of the cell cycle with a progressive number of cells accumulating in the G0 phase. Cyclin D2 was downregulated. However, differently from what was observed in T-cells stimulated in the presence of MSCs, the expression of p27 was found decreased, suggesting the involvement of similar but not identical pathways. We conclude that MSCs impair monocyte differentiation and function by interfering with the cell cycle. These findings imply that MSC-induced immunosuppression might be a side product of a more general antiproliferative effect.