Bone Marrow Stromal Cells Transplantation Research Articles

The effect of low-intensity treadmill exercise and bone marrow stromal cell transplantation on the regulation of the remyelination and soleus atrophy after sciatic nerve injury

The effect of low-intensity treadmill exercise and bone marrow stromal cell transplantation on the regulation of the remyelination and soleus atrophy after sciatic nerve injury

Synergistic effects of electroacupuncture and bone marrow stromal cells transplantation therapy in ischemic stroke.

Animal studies and clinical trials demonstrated the effectiveness of a combination of transplanted bone marrow stromal cells (BMSC) and electroacupuncture (EA) treatment in improving neurological deficits. However, the ability of the BMSC-EA treatment to enhance brain repair processes or the neuronal plasticity of BMSC in ischemic stroke model is unclear. The purpose of this study was to investigate the neuroprotective effects and neuronal plasticity of BMSC transplantation combined with EA in ischemic stroke. A male Sprague-Dawley (SD) rat middle cerebral artery occlusion (MCAO) model was used. Intracerebral transplantation of BMSC, transfected with lentiviral vectors expressing green fluorescent protein (GFP), was performed using a stereotactic apparatus after modeling. MCAO rats were treated with BMSC injection alone or in combination with EA. After the treatment, proliferation and migration of BMSC were observed in different groups by fluorescence microscopy. Quantitative real-time PCR (qRT-PCR), Western blotting, and immunohistochemistry were performed to examine changes in the levels of neuron-specific enolase (NSE) and nestin in the injured striatum. Epifluorescence microscopy revealed that most BMSC in the cerebrum were lysed; few transplanted BMSC survived, and some living cells migrated to areas around the lesion site. NSE was overexpressed in the striatum of MCAO rats, illustrating the neurological deficits caused by cerebral ischemia-reperfusion. The combination of BMSC transplantation and EA attenuated the expression of NSE, indicating nerve injury repair. Although the qRT-PCR results showed that BMSC-EA treatment elevated nestin RNA expression, less robust responses were observed in other tests. Our results show that the combination treatment significantly improved restoration of neurological deficits in the animal stroke model. However, further studies are required to see if EA could promote the rapid differentiation of BMSC into neural stem cells in the short term.

Effect of combined intervention of exercise and autologous bone marrow stromal cell transplantation on neurotrophic factors and pain-related cascades over time after sciatic nerve injury.

The purpose of this study was to determine whether combined inter-vention of treadmill exercise and bone marrow stromal cell (BMSC) transplantation would affect the expression of neurotrophic factors in the sciatic nerve injury (SNI) and neuropathic pain-related cascades in ipsilateral lumbar 4-5 dorsal root ganglion (DRG) during the early or late stage of sciatic nerve regeneration. The rats were randomly divided into the normal control group (CONT, n=6), sedentary group (SS, n=24), exercise group (SE, n=24), BMSC transplantation group (SB, n=24), BMSC transplantation+exercise group (SBE, n=24) 1, 2, 3, and 5 weeks after SNI. Single dose of 5×106 harvested BMSC was injected into the injury area sing by a 30 gauge needle. Treadmill exercise was performed at a speed of 8 m/min for 30 min once a day. Tropomyosin-receptor kinase B, brain-derived neurotrophic factor and ciliary neurotrophic fac-tor were significantly upregulated in the SE and SBE groups at 1- and 2-week postinjury than those in the CONT and SS groups, and SB and SBE groups continuously kept up proinflammatory cytokines until the late stage of regeneration. Nuclear factor kappa-light-chain-enhancer of activated B cells, interleukin and tumor necrosis factor alpha in ipsi-lateral DRG were progressively decreased by exercise alone application and/or BMSC transplantation at early and late stage of regeneration. Present results provide reliable information that combined intervention of treadmill exercise and BMSC transplantation might be one of the effective treatment strategies for recovering sciatic nerve injury-induced neuropathic pain over time.

Effect of concurrent aerobic exercise and bone marrow stromal cell transplantation on time-dependent changes of myogenic differentiation-related cascades in soleus muscle after sciatic nerve injury.

The purpose of this study was to investigate the time-dependent alteration in whether concurrent aerobic exercise and bone marrow stromal cell (BMSC) engraftment could regulate myogenic differentiation-related signaling pathway in the soleus up to 35 days after sciatic nerve injury (SNI). The rats were divided as follows: the normal control (CON, n=5), sedentary group (SED, n=20), treadmill exercise group (TEX, n=20), BMSC transplantation group (BMSC, n=20), TEX+BMSC transplantation group (TEX+BMSC, n=20) 7, 14, 21, and 35 days after SNI. SNI was applied into the thigh and treadmill exercise was comprised of walking at a speed of 4 to 8 m/min for 30 min once a day. Harvested BMSC at a density of 5×106 in 50-μL phosphate-buff-ered saline was injected into the injury site. Phosphorylated (p) extracellular signal-regulated kinase 1/2 expression was dramatically upregulated in BMSC and BMSC+EX groups from 21 days after SNI compared to those in the SED group. P-ribosomal s6 kinase (RSK) was sharply increased 14 days later, and then rapidly downregulated from day 21, whereas TEX, BMSC and TEX+ BMSC groups significantly kept up expression levels of p-RSK until 35 days post injury than SED group. TEX+BMSC group significantly increased activation of protein kinase B-mammalian target of rapamycin in the soleus from day 14 and myoblast determination protein 1-myogen-in pathways was activated in TEX+BMSC group from day 21. Present findings provide information that combined intervention of aerobic exercise and BMSC transplantation might be a reliable therapeutic strategy for overcoming the morphological and functional problems in denervated soleus muscle.

Role of Serum Inflammatory Cytokines in Sepsis Rats Following BMSCs Transplantation: Protein Microarray Analysis.

Bone marrow stromal cells (BMSCs) have emerged as a potential therapy for sepsis, yet the underlying mechanisms remain unclear. In this study, we investigated the effects of BMSCs on serum inflammatory cytokines in a rat model of lipopolysaccharide (LPS)-induced sepsis. Sepsis was induced by intravenous injection of LPS, followed by transplantation of BMSCs. We monitored survival rates for 72 h and evaluated organ functions, histopathological changes, and cytokines expression. Sepsis rats showed decreased levels of white blood cells, platelets, lymphocyte ratio, and oxygen partial pressure, along with increased levels of neutrophil ratio, carbon dioxide partial pressure, lactic acid, alanine aminotransferase, and aspartate aminotransferase. Histologically, lung, intestine, and liver tissues exhibited congestion, edema, and infiltration of inflammatory cells. However, after BMSCs treatment, there was improvement in organ functions, histopathological injuries, and survival rates. Protein microarray analysis revealed significant changes in the expression of 12 out of 34 inflammatory cytokines. These findings were confirmed by enzyme-linked immunosorbent assay. Pro-inflammatory factors, such as interleukin-1β (IL-1β), IL-1α, tumor necrosis factor-α (TNF-α), tissue inhibitor of metal protease 1 (TIMP-1), matrix metalloproteinase 8 (MMP-8), Leptin, and L-selectin were upregulated in sepsis, whereas anti-inflammatory and growth factors, including IL-4, β-nerve growth factor (β-NGF), ciliary neurotrophic factor (CNTF), interferon γ (IFN-γ), and Activin A were downregulated. BMSCs transplantation led to a decrease in pro-inflammatory cytokines and an increase in anti-inflammatory and growth factors. We summarized relevant molecular signaling pathways that resulted from cytokines in BMSCs for treating sepsis. Our results illustrated that BMSCs could promote tissue repair and improve organ functions and survival rates in sepsis through modulating cytokine networks.

Oncostatin M receptor regulates osteoblast differentiation via extracellular signal-regulated kinase/autophagy signaling

BackgroundOncostatin M receptor (OSMR), as one of the receptors for oncostatin M (OSM), has previously been shown to mediate the stimulatory role of OSM in osteoclastogenesis and bone resorption. However, it remains to be clarified whether and how OSMR affects the differentiation of osteoblasts.MethodsThe expression level of OSMR during osteoblast and adipocyte differentiation was examined. The role of OSMR in the differentiation was investigated using in vitro gain-of-function and loss-of-function experiments. The mechanisms by which OSMR regulates bone cell differentiation were explored. Finally, in vivo function of OSMR in cell fate determination and bone homeostasis was studied after transplantation of OSMR-silenced bone marrow stromal cells (BMSCs) to the marrow of ovariectomized mice.ResultsOSMR was regulated during osteogenic and adipogenic differentiation of marrow stromal progenitor cells and increased in the metaphysis of ovariectomized mice. OSMR suppressed osteogenic differentiation and stimulated adipogenic differentiation of progenitor cells. Mechanistic investigations showed that OSMR inhibited extracellular signal-regulated kinase (ERK) and autophagy signaling. The downregulation of autophagy, which was mediated by ERK inhibition, suppressed osteogenic differentiation of progenitor cells. Additionally, inactivation of ERK/autophagy signaling attenuated the stimulation of osteogenic differentiation induced by Osmr siRNA. Furthermore, transplantation of BMSCs in which OSMR was silenced to the marrow of mice promoted osteoblast differentiation, attenuated fat accumulation and osteoclast differentiation, and thereby relieved the osteopenic phenotype in the ovariectomized mice.ConclusionsOur study has for the first time established the direct role of OSMR in regulating osteogenic differentiation of marrow stromal progenitor cells through ERK-mediated autophagy signaling. OSMR thus contributes to bone homeostasis through dual regulation of osteoblasts and osteoclasts. It also suggests that OSMR may be a potential target for the treatment of metabolic disorders such as osteoporosis.

Transplantation of Roxadustat-preconditioned bone marrow stromal cells improves neurological function recovery through enhancing grafted cell survival in ischemic stroke rats.

AimsThe therapeutic effect of bone marrow stromal cell (BMSC) transplantation for ischemic stroke is limited by its low survival rate. The purpose of this study was to evaluate whether Roxadustat (FG‐4592) pretreatment could promote the survival rate of grafted BMSCs and improve neurological function deficits in ischemia rats.MethodsOxygen–glucose deprivation (OGD) and permanent middle cerebral artery occlusion (pMCAO) were constructed as stroke models in vitro and in vivo. Flow cytometry analysis and expression of Bax and Bcl‐2 were detected to evaluate BMSCs apoptosis. Infarct volume and neurobehavioral score were applied to evaluate functional recovery. Inflammatory cytokine expression, neuronal apoptosis, and microglial M1 polarization were assessed to confirm the enhanced neurological recovery after FG‐4592 pretreatment.ResultsFG‐4592 promoted autophagy level to inhibit OGD‐induced apoptosis through HIF‐1α/BNIP3 pathway. GFP and Ki67 double staining showed an improved survival rate of BMSCs in the FG‐4592 group, whereas infarct volume and neurobehavioral score verified its enhanced neurological recovery activity simultaneously. NeuN and Iba‐1 fluorescence staining showed improved neural survival and decreased microglial activation, along with decreased IL‐1β, IL‐6, and TNF‐α levels through the TLR‐4/NF‐kB pathway.ConclusionsFG‐4592 pretreated BMSCs improve neurological function recovery after stroke and are likely to be a promising strategy for stroke management.

NGF/TrkA promotes the vitality, migration and adhesion of bone marrow stromal cells in hypoxia by regulating the Nrf2 pathway.

Bone marrow stromal cells (BMSCs) transplantation is a treatment strategy for ischemic stroke (IS) with great potential. However, the vitality, migration and adhesion of BMSCs are greatly impaired due to the harsh environment of the ischemic area, which affects the therapeutic effects. Herein, we aimed to investigate the roles of nerve growth factor (NGF) in regulating cell behaviors of BMSCs in IS. The mRNA and protein expressions were assessed using qRT-PCR and western blot, respectively. To simulate ischemic-like conditions in vitro, Brain microvascular (bEnd.3) cells were exposed to oxygen and glucose deprivation (OGD). Cell viability and cell proliferation were evaluated by MTT assay and BrdU assay, respectively. Transwell migration and cell adhesion assays were carried out to determine cell migration and adhesion of BMSCs, respectively, coupled with flow cytometry to evaluate cell apoptosis of bEnd.3 cells. Finally, angiogenesis assay was performed to assess the angiogenesis ability of bEnd.3 cells. NGF overexpression resulted in increased cell vitality, adhesion and migration of BMSCs, while NGF knockdown presented the opposite effects. We subsequently discovered that TrkA was a receptor for NGF, and TrkA knockdown significantly inhibited the cell viability, migration and adhesion of BMSCs. Besides, Nrf2 was confirmed as the downstream target of NGF/TrkA to promote the viability, adhesion and migration of BMSC cells. Finally, NGF-silenced BMSCs could not effectively restore the OGD-induced brain microvascular cell damage. NGF/TrkA promoted the viability, migration and adhesion of BMSCs in IS via activating Nrf2 pathway.

Effect of treadmill exercise combined with bone marrow stromal cell transplantation on atrophy-related signaling pathway in the denervated soleus muscle.

The purpose of this study was to investigate whether combination of low-intensity exercise with bone marrow stromal cell (BMSC) transplantation could regulate protein kinas B (Akt)-mammalian target of rapamycin (mTOR) and Wnt3a-β-catenin signaling pathways for prevention of soleus muscle atrophy after sciatic nerve injury (SNI). The experimental rats divided into 5 groups (n=10): normal control group, SNI+sedentary group (SED), SNI+low-intensity treadmill exercise group (TEX), SNI+BMSC transplantation group (BMSC), SNI+TEX+BMSC transplantation group (TEX+BMSC). Sciatic nerve crush injury was applied into the middle of thigh twice for 1 min and 30 sec at interval. Low-intensity treadmill exercise was comprised of walking at a speed of 4 to 8 m/min for 30 min once a day. cultured BMSC at a density of 5×106 in 50-μL phosphate-buffered saline was injected into the distal portion of the injured sciatic nerves. TEX+BMSC group dramatically up-regulated expression levels of growth-associated protein-43 in the injured sciatic nerve at 2 weeks postinjury. Also, although Akt and mTOR signaling pathway significantly increased in TEX and BMSC groups than SED group, TEX+BMSC group showed more potent increment on this signaling in soleus muscle after SNI. Lastly, Wnt3a and the nuclear translocation of β-catenin and nuclear factor-kappa B in soleus were increased by SNI, but TEX+BMSC group significantly downregulated activity of this signaling pathway in the nuclear cell lysate of soleus muscle. Present findings provide new information that combination of low-intensity treadmill exercise might be effective therapeutic approach on restriction of soleus muscle atrophy after peripheral nerve injury.

Effect of treadmill exercise and bone marrow stromal cell engraftment on activation of BDNF-ERK-CREB signaling pathway in the crushed sciatic nerve

The effect of combined approach of exercise training and bone marrow stromal cell (BMSC) engraftment on activation of brain-derived neurotrophic factor (BDNF)-extracellular signal-regulated kinase 1 and 2 (ERK1/2)-cyclic adenosine monophosphate response element-binding protein (CREB) signaling pathway after sciatic nerve injury (SNI) was investigated. Sixty male Sprague-Dawley rats divided into the normal control, nonexercise (NEX), exercise training (EX), BMSC transplantation (TP), and exercise training+BMSC transplantation (EX+TP) groups 4 weeks after SCI. Exercise training was carried out on the treadmill device at 5–10 m/min for 20 min for 4 weeks. Single dose of 5×106 harvested BMSC was injected into the injury area of the injured sciatic nerve. In order to evaluate induction levels of BDNF-ERK1/2-CREB signaling molecules in the whole cell and nuclear cell lysates of the injured sciatic nerve, we applied Western blot analysis. BDNF was significantly increased only in EX+TP compared to NEX, EX, and TP groups. Phosphoinositide-dependent kinase-1 was more increased in EX, TP, and EX+TP groups than NEX group, but EX+TP group showed the most upregulation of phosphorylated protein kinase B compared to other groups. In addition, in the whole cell lysate, phosphorylated ERK1/2, but not activating transcription factor-3 (ATF-3) and phosphorylated CREB, was significantly increased in TP and EX+TP groups. In the nuclear cell lysate, ATF-3 and phosphorylated CREB were strongly activated in EX+TP group compared to EX group. Regular exercise training combined with BMSC engraftment would seem to be more effective in controlling activation of regeneration-related signaling pathway after SNI.

Effects of Bone Marrow Stromal Cells (BMSCs) on Behavior, Infarct Size and HIF-1αExpression in Stroke Rats

This study aims to assess BMSCs’ effect on the behavior, infarct size and HIF-1αexpression in stroke rats. Rats were separated into sham group, CVA group and BMSCs group with 10 rats in each group followed by analysis of neuroethology scores, brain tissue pathology and infarct size, and HIF-1αlevel in brain tissues. No difference of neurological scores was found between CVA group and BMSCs group after 3 hours (P> 0.05). After BMSCs transplantation, the nerve score was significantly reduced (P< 0.05) and cognitive function was significantly improved compared to CVA group. Compared with sham rats, CAV rats had a larger area of infarction and the infarcted tissue cells showed degeneration or necrosis with reduced cell number and obvious edema, which were all improved in BMSCs group. CVA group showed a larger area of infarct tissue (P< 0.05), which was reduced in BMSCs group (P< 0.05). Compared with sham group, CVA group showed significantly upregulated HIF-1αlevel (P< 0.05) which was reduced in BMSCs group (P< 0.05). BMSCs has a certain repair effect on the ethology of stroke rats possibly via inhibition of HIF-1αlevel in cerebral infarction and brain tissue.

Ultrasound-Guided Transplantation of Mesenchymal Stem Cells Improves Adriamycin Nephropathy in Rats Through the RIPK3/MLKL and TLR-4/NF-κB Signaling.

Bone marrow stromal cell (BMSC) treatment has been shown to be beneficial for Adriamycin nephropathy (ADR). However, the low transplantation rate is still the key factor that affects this strategy. This study is the first to investigate the efficacy and potential mechanism of ultrasound-guided transrenal arterial transfer of BMSCs for the treatment of ADR in rats. The ADR rat model was established by two injections of doxorubicin. In addition, the rats were randomly divided into four groups (10 rats per group): the normal group (no treatment), the medium control group (treated with medium), the Adriamycin group (treated with phosphate buffer), and the BMSC group (treated with BMSCs). After 4 weeks, the levels of serum creatinine (SCr), blood urea nitrogen (BUN), and urine albumin (ALb) were measured. In addition, pathological changes in kidney tissue were evaluated by pathological sectioning and electron microscopy. Western blotting was used to determine the levels of proteins in rat kidneys. Ultrasound-guided renal artery transplantation of BMSCs reduced the levels of SCr, BUN, and ALb and improved the pathological structure of rat kidneys compared with those in the Adriamycin group. This treatment inhibited renal cell necrosis by reducing the expression of receptor-interacting Serine/threonine Kinase 3 (RIPK3) and Mixed lineage kinase domain-like pseudokinase (MLKL) and inhibited renal inflammation and fibrosis by reducing the expression of Toll-Like receptor 4 (TLR4) and nuclear factor κB (NF-κB). Our study shows that ultrasound-guided transrenal artery transplantation of BMSCs can improve adriamycin-induced renal injury in rats by regulating the RIPK3/MLKL and TLR-4/NF-κB pathways and inhibiting renal necrosis, inflammation, and fibrosis.

Retraction.

Retraction: "miR-124a enhances therapeutic effects of bone marrow stromal cells transplant on diabetic nephropathy-related epithelial-to-mesenchymal transition and fibrosis," by Xiaojun Cai, Lei Wang, Xuling Wang, and Fengyan Hou, J Cell Biochem. 2020; 299-312: The above article, published online on 12 June 2019 in Wiley Online Library (https://doi.org/10.1002/jcb.29170), has been retracted by agreement between the authors, the journal's Editor in Chief, Prof. Dr. Christian Behl, and Wiley Periodicals LLC. The authors asked to retract their article. A detailed investigation revealed several inconsistencies in the figures. Since original data could not be provided, the overall validity of the results could not be confirmed. The authors were not available for a final confirmation of the retraction.

Articular cartilage regeneration in rats using human bone marrow stromal cells

Purpose: Injury to articular cartilage found in knee joints is often disabling and affects both younger and older individuals. Injured cartilage rarely heals, leading to a progressive loss of normal function of the joint in many cases. Current treatments are far from satisfactory. One treatment is surgery (such as drilling through the cartilage to the bone, abrasion to remove diseased cartilage and microfracture). These procedures can result in the formation of a mixture of fibrous tissue and cartilage within the injury, which does not lead to a total recovery of joint function. Autologous human bone marrow stromal cell (hBMSC) transplantation maybe a potential avenue to regenerate articular cartilage. We previously determined that naive (untreated) hBMSC were able to form stable, non-hypertrophic cartilage when transplanted subcutaneously in conjunction with fibrin microbeads covalently coated with hyaluronic acid (FMBs). In our current study, we are investigating the ability of hBMSC/FMB constructs to generate native-like cartilage in an articular defect in immunocompromised rodents. Methods: hBMSCs were obtained from surgical bone waste and grown in culture for 2-3 passages. Approval for this study was given by the institutional Animal Care and Use Committee (ACUC). To create the articular cartilage defects in immunocompromised SRG rats (Hera/Charles River), the patella was laterally displaced and the distal femur was immobilized using a clamp. The defect was made in the trochlear groove of the distal femur using a 1.8mm diameter microdrill. The defect was either left unrepaired (sham), or subsequently filled with either FMBs alone (FMBs Alone), hBMSCs attached to FMBs (FMBs+cells), or with a pellet created by incubating BMSCs with FMBs for 10 days in chondrogenic medium. At the 4-week and 8-week timepoints following surgery, the rats were euthanized and femurs were harvested and fixed in 4% paraformaldehyde for 24 hours and then decalcified using a 10% EDTA solution for 30 days. After decalcification, the femurs were paraffin embedded and sectioned at a thickness of 6 μm. Histological staining was performed using hematoxylin and eosin, toluidine blue, and safranin O methods to assess cartilage formation. Immunohistochemistry for aggrecan within the cartilage was also performed to assess cartilage proteoglycan formation. Image analysis using Image J was performed on sections stained with safranin O. Cartilage thickness was approximated based on the thickness of the intact cartilage surrounding the defect, and a region of interest (ROI) was drawn surrounding the defect with the same depth as the intact cartilage. The image color channels were separated into red, green, and blue, and the blue channel was used to threshold for the stained proteoglycan. The “analyze particles” module of Image J was used to calculate the percentage of the ROI that stained positive for proteoglycan. Second-harmonic generation microscopy was also used to evaluate collagen fibril structure and organization. Results: Toluidine blue staining revealed cartilage formation in defects at the 4-week and 8-week timepoints in both the FMBs+cells and pellet groups. No cartilage was detected in the FMBs alone or sham groups (Figure 1). Percentages of defect area positive for cartilage proteoglycan in the FMBs+cells, pellet, FMBs alone, and sham group defect areas were 8.95%, 3.03%, 0.008%, and 0.094% respectively. A comparable ROI in healthy rat cartilage showed proteoglycan positivity of 58.43% of the area (Figure 2). Second harmonic generation imaging of the defect area showed that from sham to FMB alone to pellet to FMBs+cells groups, the organization of the collagen fibrils begin to more closely approximate healthy rat cartilage (Figure 3). Long-term time points are currently being analyzed. Conclusions: At the early timepoints presented in this abstract, there is evidence of cartilage formation in the drilled articular cartilage defects in both the FMBs+cells and pellet groups. This initial data shows the potential for our method to regenerate articular cartilage in vivo. Analysis of our long-term time points will reveal the extent and quality of healing induced by hBMSCs transplanted in conjunction with FMBs.

Bone marrow stromal cells reverse the microglia type from pro-inflammatory tumour necrosis factor a microglia to anti-inflammatory CD206 microglia of middle cerebral artery occlusion rats through triggering secretion of CX3CL1.

The middle cerebral artery occlusion (MCAO) model has been extensively applied to study ischaemic stroke. This study attempted to clarify effect of bone marrow stromal cells (BMSCs) on infarct injury of MCAO rats. BMSCs were isolated and identified by staining CD29/CD44 and CD31/CD45. CX3CL1 silencing vector (pLVX-shRNA-CX3CL1) was generated and infected to BMSCs. pLVX-shRNA-CX3CL1 infected BMSCs were transplanted into brain tissue of MCAO rats. Real-time PCR was used to determine CX3CL1 expression. Infarct areas were stained with TTC to evaluate infarct size. Double-staining immunofluorescence was conducted to determine anti-inflammatory type CD206 and pro-inflammatory type tumour necrosis factor a (TNF-a) microglia. Isolated BMSCs were positively presented for CD29/CD44, and negatively for CD31/CD45. CX3CL1 was significantly lower in the BMSC + pLVX-shRNA2-CX3-CL1 group compared to the BMSCs + pLVX group (p < 0.05). According to TTC and neurological scores, MCAO rats were successfully generated. BMSCs transplantation significantly increased CD206 microglia and decreased TNF-a microglia. However, shRNA-CX3CL1-infected BMSCs remarkably reduced CD206 microglia and enhanced TNF-a microglia compared to the MCAO + BMSCs group. In conclusion, BMSCs reverse microglia from pro-inflammatory type TNF-a microglia to anti-inflammatory type CD206 microglia in the infarct region of MCAO rats (3rd to 7th days post BMSC transplantation), through triggering of CX3CL1 secretion. Therefore, the potential effects of CX3CL1 secreted by BMSCs would provide an insight for stem cell-dependent therapeutic strategies in treating ischaemic stroke-associated disorders.

Effects of Erythropoietin in White Adipose Tissue and Bone Microenvironment.

Erythropoietin (EPO) is expressed primarily in fetal liver and adult kidney to stimulate red blood cell production. Erythropoietin receptor expression is not restricted to erythroid progenitor cells, and non-erythroid EPO activity includes immune response and bone remodeling. In bone fracture models, EPO administration promotes bone formation and accelerates bone healing. In contrast, in healthy adult mice, exogenous EPO-stimulated erythropoiesis has been concomitant with bone loss, particularly at high EPO, that may be accompanied by increased osteoclast activation. Other EPO-associated responses include reduced inflammation and loss of fat mass with high-fat diet feeding, especially in male mice. While EPO exhibited a sex-dimorphic response in regulation of fat mass and inflammation in obese mice, EPO-stimulated erythropoiesis as well as EPO-associated bone loss was comparable in males and females. EPO administration in young mice and in obese mice resulted in bone loss without increasing osteoclasts, suggesting an osteoclast-independent mechanism, while loss of endogenous EPO decreased bone development and maintenance. Ossicle formation of bone marrow stromal cell transplants showed that EPO directly regulates the balance between osteogenesis and adipogenesis. Therefore, during development, endogenous EPO contributes to normal bone development and in maintaining the balance between osteogenesis and adipogenesis in bone marrow stromal cells, while EPO treatment in mice increased erythropoiesis, promoted bone loss, decreased bone marrow adipogenesis, and increased osteoclast activity. These observations in mouse models suggest that the most prevalent use of EPO to treat anemia associated with chronic kidney disease may compromise bone health and increase fracture risk, especially at a high dose.

Bone marrow mesenchymal stem cells ameliorated kidney fibrosis by attenuating TLR4/NF-κB in diabetic rats

Diabetic nephropathy (DN) is a chronic inflammatory complication of diabetes mellitus, which becomes the most common cause of end-stage renal disease (ESRD). Recently, bone marrow mesenchymal stem cells (BMSCs) are considered as a promising therapy for DN. However, the protective mechanism of BMSCs on DN remains unclear. This study was done to explore the effect of a bone marrow stromal cell (BMSCs) transplant on DN rats and rat glomerular mesangial cells in high-glucose concentration. Diabetic rats were induced by a single intraperitoneal injection of streptozotocin (STZ) 65 mg/kg, then 4 × 106 BMSCs were transplanted in diabetic rats as the treatment group. Six weeks after BMSCs transplantation, blood serum creatinine (Scr) and blood urea nitrogen (BUN) were used to test renal function. Renal pathological examination was observed by HE staining, Masson staining, PAS staining and immunohistochemistry. The results demonstrated that BMSCs could dramatically improve renal function and collagen accumulation by reducing Scr, BUN, collagen I and IV expression and histopathological abnormalities in the diabetic kidneys. Furthermore, BMSCs could significantly attenuate the expression of TLR4/NF-κB and MCP-1 in vitro and in vivo (P < 0.05, vs diabetic groups). This study reported a novel finding that BMSCs play a protective role in inhibition of inflammatory and fibrotic cytokines by down-regulating TLR-4/NF-κB expression under diabetic condition.

Impact of coadministration of apigenin and bone marrow stromal cells on damaged ovaries due to chemotherapy in rat: An experimental study.

BackgroundApigenin is a plant-derived flavonoid with antioxidative and antiapoptotic effects. Bone marrow stromal cells (BMSCs) are a type of mesenchymal stem cells (MSCs) that may recover damaged ovaries. It seems that apigenin may promote the differentiation of MSCs.ObjectiveThe aim of this study was to investigate the effect of coadministration of apigenin and BMSCs on the function, structure, and apoptosis of the damaged ovaries after creating a chemotherapy model with cyclophosphamide in rat.Materials and MethodsFor chemotherapy induction and ovary destruction, cyclophosphamide was injected intraperitoneally to 40 female Wistar rats (weighing 180–200 gr, 10 wk old) for 14 days. Then, the rats were randomly divided into four groups (n = 10/each): control, apigenin, BMSCs and coadministration of apigenin and BMSCs. Injection of apigenin was performed intraperitoneally and BMSC transplantation was performed locally in the ovaries. The level of anti-mullerian hormone serum by ELISA kit, the number of oocytes by superovulation, the number of ovarian follicles in different stages by H&E staining, and the expression of ovarian Bcl-2 and Bax proteins by western blot were assessed after four wk.ResultsThe results of serum anti-mullerian hormone level, number of oocytes and follicles, and Bcl-2/Bax expression ratio showed that coadministration of apigenin and BMSCs significantly recovered the ovarian function, structure, and apoptosis compared to the control, BMSC, and apigenin groups (p 0.001).ConclusionThe results suggest that the effect of coadministration of apigenin and BMSCs is maybe more effective than the effect of their administrations individually on the recovery of damaged ovaries following the chemotherapy with cyclophosphamide in rats.

Hypoxic preconditioning enhances the differentiation of bone marrow stromal cells into mature oligodendrocytes via the mTOR/HIF‐1α/VEGF pathway in traumatic brain injury

ObjectiveTraumatic brain injury (TBI) results not only in gray matter damage, but also in severe white matter injury (WMI). Previous findings support hypoxic preconditioning (HP) could augment the efficacy of bone marrow stromal cell (BMSC) transplantation in a TBI mouse model. However, whether HP‐treated BMSCs (H‐BMSCs) could overcome remyelination failure after WMI is unclear, and the molecular mechanisms remain to be explored. Here, we focused on the therapeutic benefits of H‐BMSC transplantation for treating WMI, as well as its underlying mechanisms.MethodsIn vitro, BMSCs were incubated at passage 4 in the hypoxic preconditioning (1.0% oxygen) for 8 hr. In vivo, a TBI mouse model was established, and DMEM cell culture medium (control), normal cultured BMSCs (N‐BMSCs), or H‐BMSCs were transplanted to mice 24 hr afterward. Neurobehavioral function, histopathological changes, and oligodendrogenesis were assessed for up to 35 days post‐TBI.ResultsCompared with the control group, improvement of cognitive functions and smaller lesion volumes was observed in the two BMSC‐transplanted groups, especially the H‐BMSC group. H‐BMSC transplantation resulted in a greater number of neural/glial antigen 2 (NG2)–positive and adenomatous polyposis coli (APC)–positive cells than N‐BMSC transplantation in both the corpus callosum and the striatum. In addition, we observed that the expression levels of hypoxia‐inducible factor‐1a (HIF‐1α), phosphorylated mechanistic target of rapamycin (p‐mTOR), and vascular endothelial growth factor (VEGF) were all increased in H‐BMSC–transplanted mice. Furthermore, the mTOR pathway inhibitor rapamycin attenuated the impact of HP both in vivo and in vitro.ConclusionThe results provided mechanistic evidences suggesting that HP‐treated BMSCs promoted remyelination partly by modulating the pro‐survival mTOR/HIF‐1α/VEGF signaling pathway.

Xenogeneic transplantation of human WJ-MSCs rescues mice from acute radiation syndrome via Nrf-2-dependent regeneration of damaged tissues.

There is an unmet medical need for radiation countermeasures that can be deployed for treatment of exposed individuals during ionizing radiation (IR) accidents or terrorism. Wharton's jelly mesenchymal stem cells (WJ-MSCs) from human umbilical cord have been shown to avoid allorecognition and induce a tissue-regenerating microenvironment, which makes them an attractive candidate for mitigating IR injury. We found that WJ-MSCs protected mice from a lethal dose of IR even when transplanted up to 24hours after irradiation, and a combination of WJ-MSCs and antibiotic (tetracycline) could further expand the window of protection offered by WJ-MSCs. This combinatorial approach mitigated IR-induced damage to the hematopoietic and gastrointestinal system. WJ-MSCs increased the serum concentration of the cytoprotective cytokines granulocyte colony-stimulating factor (G-CSF) and IL-6 in mice. Knockdown of G-CSF and IL-6 in WJ-MSCs before injection to lethally irradiated mice or transplantation of WJ-MSCs to lethally irradiated Nrf-2 knockout mice significantly nullified the therapeutic protective efficacy. Hence, WJ-MSCs could be a potential cell-based therapy for individuals accidentally exposed to radiation.