Apoptosis Of Bone Marrow Stromal Cells Research Articles

The Construction of Foot and Ankle Joint by Autologous Oxygen-Releasing Nano-Bionic Scaffold Combined with Bone Marrow Mesenchymal Stem Cells

This study assesses the role of a scaffold constructed by co-cultivating autologous oxygen-releasing nano-bionic materials and bone marrow stromal cells (BMSCs) in joint repairing. A scaffold constructed of autologous oxygen-releasing nano-bionic materials and BMSCs was transplanted into SD rats. The immunofluorescence detected the expression of nuclear antigen (PCNA) and analyzed the proliferation of BMSCs. Reverse transcription polymerase chain reaction (RT-PCR) examined the expression of osteogenic markers and TUNEL staining analyzed BMSCs apoptosis. There was a significant difference in the apoptosis and proliferation cell number of BMSCs in ankle joint between solely autologous oxygen-releasing nano-bionic material scaffold group and composite BMSCs nano-bionic scaffold (P <0.05). There was a statistical difference in PCNA and TUNEL expression between two groups at 4 weeks and 8 weeks (P <0.05). The expression of osteogenesis markers in ankle joint at 1 week, 4 weeks, and 8 weeks were continuously reduced, and the composite of autologous oxygen-releasing nanomaterials and BMSCs increased the expression of osteogenic markers (P <0.05). The composite scaffold constructed by autologous oxygen-releasing nano-bionic materials and BMSCs has a good two-way immune regulation function and is able to carry lipids, proteins, nutritional factors, and growth factors, which can effectively promote tissue engineering repairing and delay the scaffold degradation. Combined with the nano-release system to repair bone tissue, composite material can effectively promote the proliferation of joint osteoblasts and osteogenic differentiation, thus help repairing the ankle joint.

Emerging roles of circular RNAs in osteoporosis.

Osteoporosis is one bone disease characterized with skeletal impairment, bone strength reduced and fracture risk enhanced. The regulation processes of bone metabolism are associated with several factors such as mechanical stimulation, epigenetic regulation and hormones. However, the mechanism of osteoporosis remains unsatisfactory. Increasing high‐throughput RNA sequencing and circular RNAs (circRNAs) microarray studies indicated that circRNAs are differentially expressed in osteoporosis. Growing functional studies further pinpointed specific deregulated expressed circRNAs (e.g., circ_28313, circ_0016624, circ_0006393, circ_0076906 and circ_0048211) for their functions involved in bone metabolism, including bone marrow stromal cells (BMSCs) differentiation, proliferation and apoptosis. Moreover, CircRNAs (circ_0002060, Circ_0001275 and Circ_0001445) may be acted as diagnostic biomarkers for osteoporosis. This review discussed recent progresses in the circRNAs expression profiling analyses and their potential functions in regulating BMSCs differentiation, proliferation and apoptosis.

Lenalidomide abrogates the survival effect of bone marrow stromal cells in chronic lymphocytic leukemia.

In the pathogenesis of chronic lymphocytic leukemia (CLL) the microenvironment plays an important role, as it produces survival signals and mediates drug resistance. Lenalidomide, which has immunomodulatory effect, can enhance the activation of T-, NK-cells and endothelial cells, however there are no data available whether it can modulate bone marrow stromal cells (BMSCs). In our study, we investigated the effects of lenalidomide on BMSCs and CLL cells. CLL cells were cultured alone or with BMSCs and were treated with lenalidomide. Apoptosis, immunophenotype, and cytokine secretion of BMSCs and CLL cells were determined by flow cytometry. Lenalidomide slightly increased the apoptosis of CLL cells and abrogated the anti-apoptotic effect of BMSCs on CLL cells. Lenalidomide treatment decreased the expression of antigens on CLL cells, which mediate the interactions with the microenvironment. Interestingly, lenalidomide enhanced the expression of IRF4 and the co-stimulatory molecule CD86. The secretion of several cytokines was not changed significantly by lenalidomide. CD49d-negative CLL cases were more sensitive to lenalidomide treatment. Our results suggest that lenalidomide has a limited effect on BMSCs, but it renders CLL cells more immunogenic and unresponsive to survival signals provided by BMSCs.

Inhibition of HMGB1 reduced high glucose-induced BMSCs apoptosis via activation of AMPK and regulation of mitochondrial functions.

High mobility group box-1 (HMGB1) participates actively in oxidative stress damage, and the latter relates closely to diabetes and diabetic complications including osteoporosis, though the underlying mechanisms are elusive. This study aimed to investigate the effect of high glucose on bone marrow stromal cells (BMSCs) apoptosis and the role of HMGB1 in this process. BMSCs were isolated from 2-week-old Sprague-Dawley rats and cultured in medium containing normal glucose (NG), high glucose (HG), high glucose + glycyrrhizin (HMGB1 inhibitor, HG+GL), and high glucose + glycyrrhizin + dorsomorphin (AMPK inhibitor, HG+GL+Dm), respectively. Cell apoptosis, expression of HMGB1, AMPK, apoptotic markers, and mitochondrial functions were detected. By these approaches, we demonstrated that HG treatment significantly upregulated the expression of HMGB1 in BMSCs, which could be attenuated by GL treatment. Inhibiting HMGB1 by GL improved AMPK activation, decreased mitochondrial ROS levels, increased mitochondrial membrane potential, normalized mitochondrial fission/fusion balance, and consequently reduced apoptosis of BMSCs under HG condition. The addition of AMPK inhibitor dorsomorphin hampered this protective effect. Taken together, our data show that inhibition of HMGB1 can be an effective approach to alleviate HG-induced BMSCs apoptosis by activation of AMPK pathway and relieving mitochondrial dysfunction.

Effects of Co-Administration of Bone Marrow Stromal Cells and L-Carnitine on The Recovery of Damaged Ovaries by Performing Chemotherapy Model in Rat.

BackgroundL-carnitine (Lc) as a type of flavonoid antioxidants and bone marrow stromal cells (BMSCs) as a type of mesenchymal stem cells may recover damaged ovaries. It seems that Lc has favorable effects on differentiation, increasing lifespan and decreasing apoptosis in BMSCs. The aim of this study was to investigate effects of co-ad- ministration of BMSC+Lc on damaged ovaries after creating a chemotherapy model with cyclophosphamide in rats.Materials and MethodsIn this experimental study, cyclophosphamide was intraperitoneally (IP) injected to forty female wistar rats for 14 days, in terms of chemotherapy-induced ovarian destruction. The rats were then randomly divided into four groups: control, Lc, BMSCs and co-administration of BMSC+Lc. Injection of BMSCs into bilateral ovaries and intraperitoneal injection of Lc were performed individually and together. Four weeks later, levels of se- rum estradiol (E2) and follicle-stimulating hormone (FSH) using enzyme-linked immunosorbent assay (ELISA) kit, number of ovarian follicles at different stages using hematoxylin and eosin (H&E) staining and expression of ovarian Bcl-2 and Bax proteins using western blot were assessed.ResultsCo-administration of BMSC+Lc increased E2 and decreased FSH levels compared to the control group (P<0.001). The number of follicles was higher in the co-administrated group compared to the control group (P<0.001). Co-administration of BMSC+Lc increased Bcl-2 protein level, decreased Bax protein level and increased Bcl-2/Bax ratio (P<0.001).ConclusionThe effect of co-administration of BMSC+Lc is probably more effective than the effect of their separate administration on the recovery of damaged ovaries by chemotherapy.

Effects of Transplanting Bone Marrow Stromal Cells Transfected with CXCL13 on Fracture Healing of Diabetic Rats

Background/Aims: Diabetic fracture have poor treatment and serious complications. Therefore, how to treat diabetic fracture is receiving increasing attention. This study aimed to investigate the effects of transplanting CXCL13-stimulated bone marrow stromal cells (BMSCs) on the fracture healing in diabetic rats. Methods: In vitro, RT-PCR was employed to examine the expression of CXCL13 in BMSCs in high glucose environment. MTT assay and apoptosis assay were utilized to determine the effects of CXCL13 overexpression on the proliferation and apoptosis of BMSCs respectively. ALP staining was applied to detect the ALP activity. In vivo, CXCL13-stimulated BMSCs were transplanted into the fracture sites of diabetic rats. At the 1^st week, 2^nd weeks, 4^th week and 6^th week after the operation, bone mineral density (BMD) and callus area measurement, ELISA detection, and HE staining were performed to evaluate the fracture healing. Results: Low BMD and less area of callus in diabetic rats showed that the recovery after fracture was worse in diabetic rats than in non-diabetic rats. Meanwhile, the expression of CXCL13 in serum was lower in diabetic rats than in non-diabetic rats. Overexpression of CXCL13 promoted the proliferation of BMSCs in vitro high glucose environment. After BMSCs transfected with CXCL13 being transplanted into the fracture sites of diabetic rats, it was found that the fracture healing was enhanced and ALP expression in serum became higher. HE staining results further verified the effects of transplantation of BMSCs transfected with CXCL13 on fracture healing in diabetic rats. Conclusion: These finding indicated that CXCL13 may play a critical role in the process of fracture healing, which could provide a deeper insight into molecular targets for the fracture healing in diabetic people.

Hypoxic Preconditioning Augments the Therapeutic Efficacy of Bone Marrow Stromal Cells in a Rat Ischemic Stroke Model.

Transplantation of bone marrow stromal cells (BMSCs) is a promising therapy for ischemic stroke, but the poor oxygen environment in brain lesions limits the efficacy of cell-based therapies. Here, we tested whether hypoxic preconditioning (HP) could augment the efficacy of BMSC transplantation in a rat ischemic stroke model and investigated the underlying mechanism of the effect of HP. In vitro, BMSCs were divided into five passage (P0, P1, P2, P3, and P4) groups, and HP was applied to the groups by incubating the cells with 1% oxygen for 0, 4, 8, 12, and 24h, respectively. We demonstrated that the expression of hypoxia-inducible factor-1α (HIF-1α) was increased in the HP-treated BMSCs, while their viability was unchanged. We also found that HP decreased the apoptosis of BMSCs during subsequent simulated ischemia-reperfusion (I/R) injury, especially in the 8-h HP group. In vivo, a rat transient focal cerebral ischemia model was established. These rats were administered normal cultured BMSCs (N-BMSCs), HP-treated BMSCs (H-BMSCs), or DMEM cell culture medium (control) at 24h after the ischemic insult. Compared with the DMEM control group, the two BMSC-transplanted groups exhibited significantly improved functional recovery and reduced infarct volume, especially the H-BMSC group. Moreover, HP decreased neuronal apoptosis and enhanced the expression of BDNF and VEGF in the ischemic brain. Survival and differentiation of transplanted BMSCs were also increased by HP, and the quantity of engrafted BMSCs was significantly correlated with neurological function improvement. These results suggest that HP may enhance the therapeutic efficacy of BMSCs in an ischemic stroke model. The underlying mechanism likely involves the inhibition of caspase-3 activation and an increasing expression of HIF-1α, which promotes angiogenesis and neurogenesis and thereby reduces neuronal death and improves neurological function.

Bone Marrow Stromal Cells Induce Bortezomib Resistance in Multiple Myeloma Cells through Downregulation of miRNA-101-3p Targeting Survivin

INTRODUCTIONIt is not yet fully understood how bone marrow microenvironment components especially bone marrow stromal cells (BMSCs) induce drug resistance in multiple myeloma (MM). This form of drug resistance has been suggested to pave the way for intrinsic (de novo) resistance to therapy in early stages of the disease and contribute to acquired drug resistance in the course of treatment. Hence, deciphering the molecular mechanisms involved in induction of above resistance will help identify potential therapeutic targets in MM combined treatments. Our previous work showed that BMSCs (normal and MM patient-derived) induced resistance to bortezomib (BTZ) compared with MM cells in the absence of stroma. This resistance was associated with modulation of a transcriptome in MM cells, including prominent upregulation of oncogenes c-FOS, BIRC5 (survivin) and CCND1. However; whether these oncogenes mediate BTZ resistance in the context of BMSCs through interaction with miRNAs is not known.METHODSHuman myeloma cell lines, 8226, U266 and MM.1s, were co-cultured with MM patient-derived BMSCs or an immortalized normal human line (HS-5) in the presence of 5nM BTZ for 24 h. MM cell monocultures treated with 5nM BTZ were used as controls. Co-cultures were then applied to magnetic cell separation (EasySep, Stem Cell Technologies) to isolate MM cells for downstream analyses (western blotting and qPCR). Total RNA including miRNAs was isolated from MM cell pellets (QIAGEN miRNeasy kit), cDNAs were synthesized (QIAGEN miScript RT II kit) and applied to miScript miRNA PCR Array (SABioscience, MIHS-114ZA). After normalization of all extracted Ct values to 5 different housekeeping genes, fold changes in miRNA expression were analyzed in co-cultures compared to MM cell monocultures using the 2-ΔΔCt algorithm. Moreover, survivin gene was silenced in MM cells using Ambion® Silencer® Select siRNA and Lipofectamine RNAiMAX transfection reagent. Survivin-silenced cells were then seeded on BMSCs and exposed to BTZ. Percent apoptosis of gated CD138+ MM cells was determined using FACS. For our overexpression and 3'UTR reporter experiments, we transiently transfected MM cells with pre-miR-101-3p, scrambled miRNA or pEZX-3'UTR constructs using Endofectin reagent (all from GeneCopoeia).RESULTSBMSCs upregulated survivin gene / protein (a member of inhibitors of apoptosis family) and modulated an array of miRNAs in MM cells compared to MM cells in the absence of stroma. The more noticeably downregulated miRNAs were hsa-miR-101-3p, hsa-miR-29b-3p, hsa-miR-32-5p, hsa-miR-16-5p (4-30 fold) and highly upregulated ones included hsa-miR-221-3p, hsa-miR-409-3p, hsa-miR-193a-5p, hsa-miR-125a-5p (80-330 fold). We focused on miRNA-101-3p as it showed the highest level of downregulation (30 fold) and has been shown to function as an important tumor suppressor in other malignancies. Real time RT-PCR confirmed downregulation of miRNA-101-3p. Moreover, microRNA Data Integration Portal (mirDIP) identified miRNA-101-3p as a putative target for survivin and Luciferase activity assays confirmed binding of miRNA-101-3p to 3'UTR of survivin. In addition, overexpression of miRNA-101-3p downregulated survivin and sensitized MM cells to BTZ-induced apoptosis. Furthermore, silencing of survivin upregulated miRNA-101-3p and increased BTZ-induced apoptosis in MM cell lines both in the absence of BMSCs (Apoptosis range in BTZ-treated conditions: 57.65% ± 4.91 and 28.66% ± 0.78 for si-survivin and scrambled control, respectively, p<0.05) and in the presence of BMSCs (41.23% ± 1.43 and 14.8% ± 0.66, for si-survivin and scrambled control, respectively, p<0.05).CONCLUSIONOur results indicate that BMSCs downregulated miRNA-101-3p and upregulated survivin in MM cells compared to MM cells in the absence of stroma. Silencing of survivin or overexpression of miRNA-101-3p sensitized MM cells to BTZ in the presence of BMSCs. These findings suggest that miRNA-101-3p mediates BTZ response of MM cells in the presence of BMSCs by targeting survivin and disclose a role of survivin-miRNA-101-3p axis in regulation of BMSCs-induced BTZ resistance in MM cells, thus provide a rationale to further investigate the anti-myeloma activity of miRNA-101-3p in combination with BTZ as a potential novel therapeutic strategy in MM. DisclosuresNo relevant conflicts of interest to declare.

All-trans retinoic acid arrests cell cycle in leukemic bone marrow stromal cells by increasing intercellular communication through connexin 43-mediated gap junction

BackgroundGap junctional intercellular communication (GJIC) is typically decreased in malignant tumors. Gap junction is not presented between hematopoietic cells but occurred in bone marrow stromal cells (BMSCs). Connexin 43 (Cx43) is the major gap junction (GJ) protein; our previous study revealed that Cx43 expression and GJIC were decreased in acute leukemic BMSCs. All-trans retinoic acid (ATRA) increases GJIC in a variety of cancer cells and has been used to treat acute promyelocytic leukemia, but the effects of ATRA on leukemic BMSCs is unknown. In this study, we evaluated the potential effects of ATRA on cell cycle, proliferation, and apoptosis of leukemic BMSCs. Effects of ATRA on Cx43 expression and GJIC were also examined.MethodsHuman BMSCs obtained from 25 patients with primary acute leukemia, and 10 normal healthy donors were cultured. Effects of ATRA on cell cycle, cell proliferation, and apoptosis were examined with or without co-treatment with amphotericin-B. Cx43 expression was examined at both the mRNA and protein expression levels. GJIC was examined by using a dye transfer assay and measuring the rate of fluorescence recovery after photobleaching (FRAP).ResultsATRA arrested the cell cycle progression, inhibited cell growth, and increased apoptosis in leukemic BMSCs. Both Cx43 expression and GJIC function were increased by ATRA treatment. Most of the observed effects mediated by ATRA were abolished by amphotericin-B pretreatment.ConclusionsATRA arrests cell cycle progression in leukemic BMSCs, likely due to upregulating Cx43 expression and enhancing GJIC function.Electronic supplementary materialThe online version of this article (doi:10.1186/s13045-015-0212-7) contains supplementary material, which is available to authorized users.

The crucial role of vitamin C and its transporter (SVCT2) in bone marrow stromal cell autophagy and apoptosis

Vitamin C is an antioxidant that plays a vital role in various biological processes including bone formation. Previously, we reported that vitamin C is transported into bone marrow stromal cells (BMSCs) through the sodium dependent Vitamin C Transporter 2 (SVCT2) and this transporter plays an important role in osteogenic differentiation. Furthermore, this transporter is regulated by oxidative stress. To date, however, the exact role of vitamin C and its transporter (SVCT2) in ROS regulated autophagy and apoptosis in BMSCs is poorly understood. In the present study, we observed that oxidative stress decreased survival of BMSCs in a dose-dependent manner and induced growth arrest in the G1 phase of the cell cycle. These effects were accompanied by the induction of autophagy, confirmed by P62 and LC3B protein level and punctate GFP-LC3B distribution. The supplementation of vitamin C significantly rescued the BMSCs from oxidative stress by regulating autophagy. Knockdown of the SVCT2 transporter in BMSCs synergistically decreased cell survival even under low oxidative stress conditions. Also, supplementing vitamin C failed to rescue cells from stress. Our results reveal that the SVCT2 transporter plays a vital role in the mechanism of BMSC survival under stress conditions. Altogether, this study has given new insight into the role of the SVCT2 transporter in oxidative stress related autophagy and apoptosis in BMSCs.

Ytterbium ion promotes apoptosis of primary mouse bone marrow stromal cells?

One of the main target organs for the lanthanides (Ln) is bone. Previous studies revealed that ytterbium (Yb) produced damage to the skeletal system in vivo. But the effects of Yb3+ on bone marrow stromal cells (BMSCs) in vitro had not been reported. In this paper, cell viability, apoptosis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) and lactate dehydrogenase (LDH) were measured in order to study the effects of Yb3+ on BMSCs. The results indicated that Yb3+ displayed a slight positive effect on the BMSCs viability at concentrations of 1×10−6, 1×10−5, and 1×10−4 mol/L, but turned to decrease the viability of BMSCs at the highest concentration of 1×10−3 mol/L for 24, 48 and 72 h. Yb3+ at 1×10−3 mol/L promoted apoptosis of BMSCs, increased the levels of ROS and LDH, and decreased MMP in BMSCs. It suggested that the precipitate of YbPO4 might decrease the viability of BMSCs. Yb3+ induced the apoptosis of BMSCs via mitochondrial pathway. The results might be useful for more rational application of Yb-based compounds in the future.

Protective Effect of Neuropeptide Substance P on Bone Marrow Mesenchymal Stem Cells against Apoptosis Induced by Serum Deprivation.

Substance P (SP) contributes to bone formation by stimulating the proliferation and differentiation of bone marrow stromal cells (BMSCs); however, the possible involved effect of SP on apoptosis induced by serum deprivation (SD) in BMSCs is unclear. To explore the potential protective effect of SP and its mechanism, we investigated the relationships among SP, apoptosis induced by SD, and Wnt signaling in BMSCs. SP exhibited a protective effect, as indicated by a reduction in the apoptotic rate, nuclear condensation, caspase-3 and caspase-9 activation, and the ratio of Bax/Bcl-2 that was observed after 24 h of SD. This protective effect was blocked by the inhibition of Wnt signaling or antagonism of the NK-1 receptor. Moreover, SP promoted the mRNA and protein expression of Wnt signaling molecules such as β-catenin, p-GSK-3β, c-myc, and cyclin D1 in addition to the nuclear translocation of β-catenin, indicating that active Wnt signaling is involved in SP inhibition of apoptosis. Our results revealed that mediated by the NK-1 receptor, SP exerts an inhibitory effect on serum deprivation induced apoptosis in BMSCs that is related to the activation of canonical Wnt signaling.

Effects of methylthiouracil on the proliferation and apoptosis of rat bone marrow stromal cells.

The aim of the present study was to investigate the effects of methylthiouracil (MTU) on the proliferation and apoptosis of rat bone marrow stromal cells (BMSCs). Rat BMSCs were isolated, cultured in vitro and treated with various concentrations of MTU. Cell growth curves were determined using the Cell Counting Kit-8 method and the effect of MTU on BMSCs in a logarithmic growth phase was observed. BMSC apoptosis following MTU treatment was detected by flow cytometry. The experimental results demonstrated that the proliferation-inhibition effect was gradually enhanced with increasing MTU concentrations and the extension of treatment time. Statistically significant differences were observed between the treatment and the control groups (P<0.05). In addition, the BMSC apoptosis rate gradually increased with increasing drug concentrations and treatment time extension; statistically significant differences were observed between the treatment and the control groups (P<0.05). Therefore, the results of the present study demonstrated that MTU inhibited the proliferation of BMSCs and promoted apoptosis, indicating the cytotoxic effects of MTU on BMSCs.

AGEs induce caspase-mediated apoptosis of rat BMSCs via TNFα production and oxidative stress

Diabetic humans and animals exhibit lower bone mass and healing, resulting from diminished bone formation. We have recently reported that type 1 diabetic rats have fewer bone marrow osteoprogenitor cells, and since the formation of advanced glycation end products (AGEs) in bone increases in diabetes, we explored possible mechanisms involved in AGE-induced apoptosis of rat bone marrow stromal cells (BMSCs). BMSCs isolated from 4-month-old rats were exposed to 10-400 μg/ml AGE-BSA for 16 h and apoptosis was quantified with PI/annexin V staining and flow cytometry. Signaling mechanisms were evaluated by preincubating the cells with appropriate inhibitors. The formation of reactive oxygen species (ROS) was quantified by flow cytometric analysis of DCFDA fluorescence and the expression of genes by RT-PCR analysis. AGE-BSA at a concentration of 400 μg/ml increased the apoptosis of BMSCs two- to threefold, an effect completely blocked by a pan-caspase inhibitor. BSA or high concentrations of glucose had no effect. AGE-BSA-induced BMSC apoptosis was attenuated by a p38 inhibitor but not by an NF-κB inhibitor. Treatment with AGE-BSA induced the expression of several pro-apoptotic ligands and receptors, most notably tumor necrosis factor α (TNFα), TRAIL, lymphotoxin alpha, CD40, and TNFR2. Furthermore, AGE-BSA-induced apoptosis was completely blocked by pirfenidone, an inhibitor of TNFα production/secretion. Finally, AGE-BSA increased the production of ROS in BMSCs, and its apoptogenic effect was blocked by the antioxidant N-acetylcysteine (N-acetyl-L-cysteine). Thus, AGE-BSA increases the apoptosis of rat BMSCs via the activation of caspases, involving TNFα production/secretion, p38 MAPK signaling, and oxidative stress. We propose that increased protein glycation, such as that occurring under hyperglycemia, causes the apoptosis of BMSCs, which might significantly contribute to the development of osteopenia in diabetic animals.

Thulium Ion Promotes Apoptosis of Primary Mouse Bone Marrow Stromal Cells

Bone is one of the main target organs for the lanthanides (Ln). Biodistribution studies of Tm-based compounds in vivo showed that bone had significant uptake. But the effect of Tm(3+) on primary mouse bone marrow stromal cells (BMSCs) has not been reported. So we investigated the effect and underlying mechanisms of Tm(3+) on BMSCs. Cell viability, cell apoptosis, reactive oxygen species (ROS) level, lactate dehydrogenase (LDH) activity and mitochondrial membrane potential (MMP) were studied. The results indicated that Tm(3+) increased the viability of BMSCs at concentrations of 1×10(−7), 1×10(−6), 1×10(−5), and 1×10(−4) mol/L in a dose-dependent manner, turned to decrease the viability of BMSCs at the highest concentration of 1×10(−3) mol/L for 24, 48, and 72 h. Tm(3+) at 1×10(−3) mol/L promoted apoptosis of BMSCs, increased the ROS and LDH levels, and decreased MMP in BMSCs. Taken together, we demonstrated that Tm(3+) + at 1×10(−3) mol/L might induce cellular apoptosis through mitochondrial pathway. These resultsmay be helpful for more rational application of Tm-based compounds in the future.

Transplanting p75-suppressed bone marrow stromal cells promotes functional behavior in a rat model of spinal cord injury.

Bone marrow stromal cells (BMSC) have been successfully employed for movement deficit recovery in spinal cord injury (SCI) rat models. One of the unsettled problems in cell transplantation is the relative high proportion of cell death, specifically after neural differentiation. According to our previous studies, p75 receptor, known as the death receptor, is only expressed in BMSC in a time window of 6-12 hours following neural induction. Moreover, we have recently reported a decreased level of apoptosis in p75-suppressed BMSC in vitro. Therefore, our objective in this research was to explore the functional effects of transplanting p75:siRNA expressing BMSC in SCI rats. Laminectomy was performed at L1 vertebra level to expose spinal cord for contusion using weight-drop method. PBS-treated SCI rats (group one) were used as negative controls, in which cavitations were observed 10 weeks after SCI. pRNA-U6.1/Hygro- (group two, as a mock) and pRNA-U6.1/Hygro-p75 shRNA- (group three) transfected BMSC were labeled with a fluorescent dye, CM-DiI, and grafted into the lesion site 7 days after surgery. The Basso-Beattie-Bresnehan locomotor rating scale was performed weekly for 10 weeks. There was a significant difference (P≤0.05) between all groups of treated rats regarding functional recovery. Specifically, the discrepancy among p75 siRNA and mock-transfected BMSC was statistically significant. P75 siRNA BMSC also revealed a higher level of in vivo survival compared to the mock BMSC. Our data suggest that genetically modified BMSC that express p75:siRNA could be a more suitable source of cells for treatment of SCI.

High-Frequency Vibration Treatment of Human Bone Marrow Stromal Cells Increases Differentiation toward Bone Tissue

In order to verify whether differentiation of adult stem cells toward bone tissue is promoted by high-frequency vibration (HFV), bone marrow stromal cells (BMSCs) were mechanically stimulated with HFV (30 Hz) for 45 minutes a day for 21 or 40 days. Cells were seeded in osteogenic medium, which enhances differentiation towards bone tissue. The effects of the mechanical treatment on differentiation were measured by Alizarin Red test, (q) real-time PCR, and protein content of the extracellular matrix. In addition, we analyzed the proliferation rate and apoptosis of BMSC subjected to mechanical stimulation. A strong increase in all parameters characterizing differentiation was observed. Deposition of calcium was almost double in the treated samples; the expression of genes involved in later differentiation was significantly increased and protein content was higher for all osteogenic proteins. Lastly, proliferation results indicated that stimulated BMSCs have a decreased growth rate in comparison with controls, but both treated and untreated cells do not enter the apoptosis process. These findings could reduce the gap between research and clinical application for bone substitutes derived from patient cells by improving the differentiation protocol for autologous cells and a further implant of the bone graft into the patient.

Pinch-1 was up-regulated in leukemia BMSC and its possible effect

Pinch-1, a widely expressed focal adhesion protein, has been demonstrated to be up-regulated in multiple solid tumor-associated stromal cells, particularly at invasive edges. It was supposed that Pinch-1 was intimately associated with development and progression of tumors. The expression of Pinch-1 in hematopoietic microenvironment in patients with leukemia remains unclear. This study focused on the expression of Pinch-1 in bone marrow stromal cells (BMSCs) from leukemia patients and its possible effect. BMSC was isolated and cultured from bone marrow in leukemia patients and normal healthy donors. RT-PCR and Western blot analysis were performed to determine Pinch-1 mRNA and protein level in BMSC, respectively. Lentiviral vector containing Pinch-1 siRNA was constructed, and the recombinant lentivirus particle was packaged in 293 cells. Effectiveness of Pinch-1 siRNA was determined by Western blot. The proliferation, apoptosis and motility of leukemia BMSC subjected to Pinch-1 knockdown using siRNA were tested by flow cytometry, TUNEL assay and Transwell system, respectively. Pinch-1 mRNA and protein were significantly up-regulated in ALL and AML BMSC compared to normal BMSC (p<0.01). Although there was no difference in Pinch-1 mRNA between ALL and AML BMSC, cellular levels of Pinch-1 protein in ALL BMSC were significantly higher than that in AML BMSC (p<0.01). Overexpressed Pinch-1 was significantly reduced in leukemia BMSC transfected with Pinch-1 siRNA evidenced by Western blot. Flow cytometry analysis showed that the percentage of cells in S+G2 phases in leukemia BMSC transfected with Pinch-1 siRNA was significantly lower than control (p<0.01). The percentage of apoptotic cells in leukemia BMSC transfected with Pinch-1 siRNA was 19.8±1.0%, significantly higher than controls (p<0.01). The number of leukemia BMSC transfected with Pinch-1 siRNA that migrated to the lower chamber after culturing for 24 h was 8.4±1.1 per field, significantly lower than controls (p<0.01). Pinch-1 mRNA and protein in leukemia BMSC were up-regulated drastically compared with BMSC from healthy donors. Leukemia BMSC displayed hypoproliferation, decreased migration and increased apoptosis after transfecting Pinch-1 siRNA.

Protective effects and mechanism of Panax Notoginseng saponins on oxidative stress-induced damage and apoptosis of rabbit bone marrow stromal cells

To investigate the effects and possible mechanism of Panax Notoginseng saponins (PNS) on oxidative stress-induced damage and apoptosis in bone marrow stromal cells (BMSCs). BMSCs were isolated and cultured from 2-month-old New Zealand rabbits by the density gradient centrifugation combined with adherent method. The third passage cells were used for subsequent experiments. Oxidative stress was induced in cultured BMSCs by H(2)O(2) (0.1 mmol/L). BMSCs were pretreated with 25-200 μg/mL PNS for 4 h before H(2)O(2) treatment. Proliferation of BMSCs was observed using MTT assay. Alkaline phosphatase (ALP) activity, as an index of early osteoblastic differentiation, was determined with an ALP assay kit. Flow cytometry was used to observe the apoptosis of BMSCs by staining with annexinV-FITC/propidium iodide. Oxidative stress level was examined by reactive oxygen species (ROS) assay. The protein expressions of Bax, Bcl-2 and Caspase-3 in BMSCs were analyzed by Western blotting. PNS had different concentration-dependent effects on proliferation and osteoblast differentiation of BMSCs induced by H(2)O(2). A PNS concentration of 100 μg/mL was determined as the optimal effective concentration. PNS markedly attenuated H(2)O(2)-induced apoptosis rate from 41.91% to 14.67% (P<0.01). PNS significantly decreased ROS level induced by H(2)O(2) (P<0.01). Furthermore, pretreatment with PNS significantly reversed H(2)O(2)-induced inhibition of Bcl-2 expression and augmentation of Bax and Caspase-3 expression (P<0.01). PNS had a protective effect on oxidative stress-induced damage and apoptosis in cultured rabbit BMSCs through scavenging ROS and regulating the Bcl-2/Bax pathway.

Dysregulation of the Receptor Activator of NF-κB Ligand and Osteoprotegerin Production Influence the Apoptosis of Multiple Myeloma Patients’ Bone Marrow Stromal Cells Co-Cultured with Myeloma Cells

The interaction of multiple myeloma (MM) cells and bone marrow stromal cells (BMSCs) induces profound changes in the bone marrow environment, influencing osteoclastogenesis and MM cell survival. Differences in receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) production in BMSCs derived from MM patients and control subjects and the apoptosis of BMSCs and MM cells in co-cultures of both cell types were examined. RANKL and OPG expressions were examined by ELISA and semiquantitative RT-PCR. Apoptosis of BMSCs after contact with RPMI8226 and U266 cells was measured by flow cytometry and the level of ALP activity by the spectrophotometric method. OPG production by BMSCs was significantly inhibited after direct contact with RPMI8226 cells. Production of soluble RANKL was enhanced and the increase was more significant in the BMSCs of the MM patients than in those of the controls. In co-cultures of BMSCs and MM cells, significant apoptosis was detected with a concomitant decrease in ALP activity. This apoptosis decreased significantly in the presence of RANK-Fc, an antagonist of RANKL. Disturbances in the RANKL/OPG system are more profound in the BMSCs of MM patients than in those of control subjects after direct contact with RPMI8226 cells. Moreover, direct contact with RPMI8226 and U266 cells induces apoptosis of BMSCs which is mediated by an overproduction of RANKL.