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Osteonecrosis of the femoral head （ONFH） is a serious orthopedic disease caused by many factors. It is difficult to cure clinically and has a poor prognosis， which poses a serious threat to human health. The pathogenesis of this disease is still unclear. The ONFH caused by different causes involves the disorder of a variety of metabolic pathways in vivo. Abnormal proliferation and differentiation of bone mesenchymal stem cells （BMSCs）， imbalance of bone metabolism， and increased destruction of bone trabeculae caused by abnormal transduction of bone metabolism-related signaling pathways may be the important causes of ONFH. BMSCs are pluripotent stem cells with self-renewal and multidirectional differentiation ability， which have good regeneration rate. Improving the osteogenic and differentiation ability of BMSCs is the key to inhibit bone absorption and promote bone matrix reconstruction， which plays an important role in bone remodeling. In recent years， there are many studies on the prevention and treatment of ONFH in traditional Chinese medicine（TCM）， and it has been found that a variety of single herbs， monomers and compounds can regulate the differentiation direction and process of BMSCs by targeting signal molecules， with great potential for bone defect repair and anti-femoral head necrosis activity. Nowadays， prevention and treatment of ONFH by regulating bone metabolism signaling pathways has become a hot research topic. In this paper， the mechanism and related signal transduction pathways of TCM in preventing and treating ONFH were reviewed to explore some mechanisms of alleviating the rate of bone loss， promoting bone formation， and repairing bone defects， so as to provide reference for further research on the prevention and treatment of ONFH by TCM. The related clinical application studies also provided specific targets for gene-assisted therapy of ONFH.
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BACKGROUND: Bone marrow mesenchymal stem cells have been extensively applied in animal experiments and clinical studies. The cell concentration, treatment times and results in each study are different, and there is no standard for optimal cell concentration. OBJECTIVE: To investigate the optimal concentration of bone mesenchymal stem cells injected into articular cavity in the treatment of rabbit cartilage defects. METHODS: Thirty 6-month-old New Zealand white rabbits were selected and randomly divided into control, 1×108, 1×109, 1×1010, and 1×1011/L groups. Cartilage defect models with diameter of 3 mm and depth of 2 mm were established in femoral trochlea in each group. One week after modeling, 1 mL of normal saline was injected into the rabbit’s knee of the control group. The other groups were injected with bone marrow mesenchymal stem cells at corresponding concentrations. After 6 and 12 weeks, gross observation, hematoxylin-eosin staining, Safranin-O-fast green-staining, type I and II collagen staining were performed to assess the cartilage regeneration. RESULTS AND CONCLUSION: In the control group, the defect area was obvious with no cartilage regeneration. The 1×108, 1×109, and 1×1010/L groups showed cartilage regeneration. The repairing effect was increased with the cell concentration increasing. The effect of cartilage repair in the 1×1011/L group was similar to that in the 1×1010/L group (P > 0.05). Therefore, 1×1010/L is the optimal concentration for intra-articular injection of bone marrow mesenchymal stem cells for treating cartilage defects, and higher concentration cannot enhance the repairing effect.
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Objective To evaluate therapeutic effects of bone marrow mesenchymal stem cells(MSC)derived exosomes on alcohol-induced liver injury.Methods Eighteen male C57BL/6 mice aged 6 to 8 week were randomly divided into control group,model group and exosomes group,with 6 mice in each group.The mice in the model group and the exosomes group were fed with Lieber-DeCarli ad libitum diet(Dyets Inc.)for 4 weeks,followed by gavage a bolus of ethanol at day 26,27 and 28.The mice in the control group matched the alcohol-derived calories with dextran-maltose.Meanwhile,the mice in exosomes group were injected with MSC-exosomes via the tail vein at day 14 and 26.After the experiment,serum levels of alanine aminotransferase(ALT)and aspartate aminotransaminase(AST)were detected,and the pathological changes of liver tissues were observed.The expressions of nuclear factor erythroid 2-related factor 2(Nrf-2),heme oxygenase-1(HO-1),CD63,CD81,TSG101 and Cytochrome C were analyzed by Western blot,and mRNA levels of Nrf-2,HO-1,interleukin(IL)-10 and IL-17 were analyzed by real-time polymerase chain reaction(RT-PCR).The commercial kits were used to detect serum IL-10,IL-17 levels and liver tissue malondialdehyde(MDA),glutathione(GSH),superoxide dismutase(SOD)oxidative stress indicators.The numbers of regulatory T cell(Treg)and help T(Th)17 cells in the liver were analyzed by flow cytometry.One-way analysis of variance was used for comparison between groups.Results MSC-exosomes expressed positive markers CD63,CD81 and TSG101,but did not express the negative markers Cytochrome C.The serum ALT and AST levels in model group were(87.3±25.1)U/L and(223.2±43.5)U/L,respectively,while those in exosomes group were(47.7±12.0)U/L and(128.2±33.6)U/L,respectively.The differences between the two groups were both statistically significant(F=12.818 and 12.226,respectively,both P<0.05).Compared with control group,the SOD activity and GSH level in the model group significantly decreased with statistically significant differences(F=4.245 and 24.074,respectively,both P <0.05).Lieber-DeCarli ethanol feeding significantly increased intrahepatic MDA level in the model mice,which was reversed by MSC-exosomes supplementation,and the difference was statistically significant(F=36.675,P <0.05).Compared with control group,the intrahepatic protein expressions of Nrf-2 and HO-1 in model group were significantly decreased,while the expressions in exosomes group were obviously increased.The differences were statistically significant(F=33.623 and 14.960,respectively,both P <0.05).The expression trends of Nrf-2 and HO-1 mRNA were the same as those of protein expressions(F=20.784 and 276.336,respectively,both P <0.05).The proportions of liver Treg/Th17 in the control group,model group and exosomes group were 4.3±0.9,0.4±0.2,and 3.4±0.5,respectively.The differences among groups were statistically significant(F=64.227,P <0.05).Compared with control group,the serum protein and intrahepatic gene expression of IL-17 in the model group were significantly increased,which were reversed by MSC-exosomes treatment.The differences were statistically significant(F=15.581 and 40.095,respectively,both P<0.05).Serum IL-10 protein levels and intrahepatic IL-10 gene expression were significantly decreased after Lieber-DeCarli ethanol feeding,which were lower than the exosomes group.The differences were statistically significant(F=98.268 and 153.743,respectively,both P <0.05).Conclusions MSC-exosomes transplantation may relieve alcohol-induced liver injury.The mechanism could involve reduction of oxidative stress in the liver via regulating Nrf-2/HO-1 and normalizing the balance of Treg and Th17 cells.
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Vibration represents a micro reciprocating motion of a particle or object along a line or arc relative to a reference position, while the effect of low-magnitude high-frequency vibration (LMHFV) on skeletal system cells is similar to the mechanical stimulation of muscle movement. Bone mesenchymal stem cells (BMSCs), which have been identified as force-sensitive cells, exist in the bone marrows and have the potential of multi-lineage differentiation. Their biological characteristics can change functionally according to the appropriate stimulation in vitro, in order to reach the optimal demand of the stimulation. LMHFV can promote the osteogenic differentiation of BMSCs, therefore, the research on its mechanism can contribute to the application of vibration in the treatment of diseases such as osteoporosis, fracture, osteogenesis imperfecta, obesity as well as the promotion of orthodontic tooth movement. This paper summarizes the recent progress about the effects of vibration on BMSCs stem cells in osteogenesis and the possible mechanisms, so as to provide research ideas and methods for studying the mechanical as well as biological changes of BMSCs under vibration stimulation.
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Extracellular matrix is the main element to provide mechanical clues for cells. The response of stem cells to mechanical signals is mainly achieved through the cytoskeleton. After mechanical signal is transmitted, cytoskeleton can form contractile microfilaments that actively generate tension through reorganization induced by microenvironment changes. The mechanical signals can regulate gene expression through either coupling with the nuclear skeleton directly or being transformed by the second message. Recent studies have proven that cytoskeleton tension has a series of impact on lineage specification, proliferation, differentiation and apoptosis of bone mesenchymal stem cells (BMSCs). BMSCs are of great significance in bone reconstruction and clinical treatment. The possible mechanisms about mechanotransduction and its effects of cytoskeleton tension on osteogenesis of BMSCs after micro-environmental changes were summarized.
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Vibration represents a micro reciprocating motion of a particle or object along a line or arc relative to a reference position, while the effect of low-magnitude high-frequency vibration (LMHFV) on skeletal system cells is similar to the mechanical stimulation of muscle movement. Bone mesenchymal stem cells (BMSCs), which have been identified as force-sensitive cells, exist in the bone marrows and have the potential of multi-lineage differentiation. Their biological characteristics can change functionally according to the appropriate stimulation in vitro, in order to reach the optimal demand of the stimulation. LMHFV can promote the osteogenic differentiation of BMSCs, therefore, the research on its mechanism can contribute to the application of vibration in the treatment of diseases such as osteoporosis, fracture, osteogenesis imperfecta, obesity as well as the promotion of orthodontic tooth movement. This paper summarizes the recent progress about the effects of vibration on BMSCs stem cells in osteogenesis and the possible mechanisms, so as to provide research ideas and methods for studying the mechanical as well as biological changes of BMSCs under vibration stimulation.
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OBJECTIVE@#To evaluate the effect of zoledronate acid (ZA) on the proliferation and osteogenic differentiation of rat mesenchymal stem cells (BMSCs).@*METHODS@#The BMSCs isolated from the SD rats were cultured with different concentrations of ZA (1, 5, 10, and 20 μmol·L), and the contro1 group received the same volume of culture medium but without ZA. Cell counting kit-8 was used to detect proliferation activity in each group. Alkaline phosphatase (ALP) staining and alizarin red staining were used to detect the osteogenic differentiation ability in each group. The gene expression levels of ALP, bone morphogenetic protein-2 (BMP-2), typeⅠcollagenase (COL-Ⅰ), runt-related transcription factor-2 (Runx-2), zinc finger structure transcription factor (Osx), osteocalcin (OCN), and osteopontin (OPN) were evaluated by real-time quantitative polymerase chain reaction (qRT-PCR).@*RESULTS@#Zoledronate at 1 μmol·L⁻¹ concentration had no effect on the proliferation and osteogenic differentiation of BMSCs. No significant difference was observed between this group and the control group (P>0.05). When the ZA concentration was more than 1 μmol·L⁻¹, ZA inhibited the proliferation and osteogenic differentiation of BMSCs, and the effect was concentration dependent. The difference between each group and the control group was statistically significant (P<0.05). At ZA concentration of 5 μmol·L⁻¹, ZA enhanced the expression of ALP, BMP-2, COL-Ⅰ, Runx-2, Osx, OCN, and OPN (P<0.05). However, at ZA concentration of more than 5 μmol·L⁻¹, the expression levels of osteogenicrelated genes in each group was lower than those of the control group (P<0.05).@*CONCLUSIONS@#Low ZA concentration has no effect on the proliferation and osteogenic differentiation of BMSCs. ZA at 5 μmol·L⁻¹ concentration inhibits the proliferation but promotes the osteogenic differentiation of BMSCs. High ZA concentration inhibits the proliferation and osteogenic differentiation of BMSCs.
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Animals , Rats , Bone Marrow Cells , Cell Differentiation , Cell Proliferation , Cells, Cultured , Mesenchymal Stem Cells , Osteogenesis , Rats, Sprague-DawleyABSTRACT
To investigate the differentiation of bone mesenchymal stem cells(BMSCs) into chon-drocytes by miRNA-206 and its mechanism in osteoarthritis(OA). Methods From January, 2017 to July, 2018, rat BMSCs were isolated, and their CD90 and CD45 were detected by flow cytometry. Transfection of miRNA-206 or miRNA-206 inhibitors into BMSCs using lentiviral vectors, dexamethasone induction for 14 d, then use alician blue staining and type II collagen immunostaining to detect chondrogenic differentiation. MTT assay was used to detect the proliferation of mesenchymal stem cells. Western blot analysis was used to detect the Aggrecan, Col II, Sox9 and Runx2 markers in chondroblast cells. The expression level of the marker gene of Sox9 mRNA in chondroblasts were detected by RT-PCR.OA rat models were treated with lentiviral vectors transfected with miRNA-206 or miRNA-206 inhibitors, and Aggrecan, Col II, Sox9, Runx2 which were the markers of chondrogenesis were detected by Western blot. Results The purity of isolated BMSCs was (80.7±3.9)%. BMSCs transfected with miRNA-206 could promote cell proliferation and increase chondrogenic differentiation. Western blot results showed that the expression of Aggre-can, Col II and Sox9 was increased in the miRNA-206 transfection group, and the expression of Runx2 was down-regulate. Meanwhile, RT-PCR results showed that miRNA-206 can up-regulate the expression of the chondroblast marker gene Sox9 mRNA in BMSCs.Compared with the OA group, miRNA-206 could increase the expression of Aggre-can, Col II and Sox9 signaling proteins in cartilage tissue (P＜0.05), and down-regulate the expression level of Runx2 (P＜0.05). Conclusion The miRNA-206 can positively regulate the differentiation of BMSCs into chondrocytes, increase the ability of cell proliferation, up-regulate the expression of Aggrecan, Col II and Sox9, and down-regulate Runx2.The miRNA-206 increase chondrogenic capacity in rat models of osteoarthritis.
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Objective: To isolate, culture and identify rabbit bone mesenchymal stem cells (BMSCs) so as to explore the optimal conditions for lentiviral vector-mediated enhanced green fluorescent protein (eGFP) infection in rabbit BMSCs and screen stable transfected BMSCs in rabbits. Methods: BMSCs were obtained by whole bone marrow adherence method. The osteogenic, chondrogenic and adipogenic differentiation of BMSCs was made by alizarin red, toluidine blue and oil red O staining, respectively. The expressions of CD44 and CD90 were detected by immunofluorescence. The concentration of puromycin was used to screen the minimum lethal concentration of BMSCs; the lentiviral vector with multiplicity of infection (MOI) of 50, 100, 150 and 200 mediated eGFP BMSCs were infected; the fluorescence expression was observed under an inverted microscope, and the stable transformation system was screened with puromycin. Results: When MOI was 150, lentiviral vector-mediated eGFP infection of rabbit BMSCs was the most efficient. The optimum concentration of puromycin for stable transfection of rabbit BMSCs was 1.0 μg/mL. Conclusion: Rabbit BMSCs were successfully cultured in this experiment. The stem cells were labeled with lentivirus-mediated GFP and stable transfected rabbit BMSCs were screened. A simple and effective stem cell labeling method was established to label BMSCs in vivo.
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OBJECTIVE@#To observe the effect of acupoint injection of bone mesenchymal stem cells (BMSCs) combined with Chinese herbs of benefiting for activating blood circulation for capillary density and arterioles density in skeletal muscle in ischemic hind limb of diabetes mellitus (DM) rats.@*METHODS@#A total of 80 rats were randomized into a normal sham operation group (10 rats) and a model group (70 rats). Disposable intraperitoneal injection of streptozotocin (STZ, 50.0 mg/kg) was used to establish DM model, and the rats in the model group were randomized into 7 subgroups, 10 rats in each one. The subgroups were the DM sham operation group, DM ischemic group, Chinese herb group (intragastric herbs of benefiting for activating blood circulation), local injection group (BMSCs local injection), local injection + Chinese herb group (BMSCs local injection combined with intragastric herbs of benefiting for activating blood circulation), acupoint injection group (BMSCs acupoint injection), acupoint injection + Chinese herb group (BMSCs acupoint injection combined with intragastric herbs of benefiting for activating blood circulation). The local injection was phosphate buffer (PBS) injection at the equidistant 5 points along the line between the ischemic tissue and the normal tissue a time. The acupoints were "Sanyinjiao" (SP 6), "Zhaohai" (KI 6), "Huantiao" (GB 30), "Housanli" (ST 36) and "Yanglingquan" (GB 34). 100 μL BMSCs with 1×10/mL was totally injected at the above acupoints for one rat, 20 μL an acupoint. 1.5 kg/L Chinese herbs were applied by intragastric administration, including 120 g Radix Astragali, 120 g Codonopsis, 48 g Radix Glycyrrhiza, 120 g Angelica sinensis, 120 g Blood Rattan, 48 g Achyranthes bidentata. Intragastric distilled water was used in the other non-Chinese herb groups. The expressions of α-smooth muscle actin (α-actin), latelet endothelial cell adhesion molecule (CD31) and von willebrand factor (vWF) in the skeletal muscle were detected with immunohistochemical SP two-step method.@*RESULTS@#Twenty-one days after intervention, the expressions of α-actin and CD31 on the operation hind limb were higher than those on the healthy hind limb in all the groups, except the Chinese herb group (<0.05<0.01). The vWF expressions on the operation side were lower than those on the healthy side in the Chinese herb group, the local injection group, the local injection + Chinese herb group and the acupoint injection + Chinese herb group (<0.05, <0.01). The α-actin expression on the operation side in the acupoint injection + Chinese herb group was higher than those in the normal sham operation group, DM sham operation group, the DM ischemic group and the local injection group (<0.05, <0.01). The CD31 expressions in the acupoint injection group, the acupoint injection + Chinese herb group, local injection + Chinese herb group were higher than those in the normal sham operation group, DM sham operation group and DM ischemic group (<0.05, <0.01). The CD31 expression in the acupoint injection + Chinese herb group was higher than those in the Chinese herb group and the local injection group (both <0.05). The vWF expressions in the local injection + Chinese herb group, the acupoint injection group and the acupoint injection + Chinese herb group lower than those in the DM sham operation group and the DM ischemic group (<0.05, <0.01).@*CONCLUSION@#schemia increases the expressions of the vascular density related factors of α-actin and CD31. It is more obvious for the increasing expressions of α-actin and CD31, and decreasing expression of vWF with the interventions of simple BMSCs injection and simple Chinese herbs of benefiting for activating blood circulation, especially with the combination of the above tow methods. It is indicated that acupoint injection of BMSCs combined with Chinese herbs of benefiting for activating blood circulation can improve the angiogenesis of ischemic tissue.
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Animals , Rats , Acupuncture Points , Diabetes Mellitus , Ischemia , Lower Extremity , Mesenchymal Stem Cells , Rats, Sprague-DawleyABSTRACT
<p><b>OBJECTIVE</b>This study aimed to investigate the role and mechanism of neuropeptide substance P (SP) in ST2 cell (bone mesenchymal stem cells of mice) osteogenic differentiation to provide a basis for the treatment of temporomandibular joint osteoarthritis.</p><p><b>METHODS</b>Third-generation ST2 cells were cultured with different concentrations of SP (0, 10⁻¹⁰, 10⁻⁸, 10⁻⁶, and 10⁻⁵ mol·L⁻¹). After 24, 48, and 72 h, cell proliferation was detected by CCK-8. The ST2 cells were cultured with 10⁻⁶ mol·L⁻¹ SP for 1, 3, 5, and 7 days. Subsequently, the expression of alkaline phosphatase (ALP), collagen typeⅠ(CollaⅠ), and osteocalcin (OCN) in the culture supernatant was tested by enzyme-linked immunosorbent assay (ELISA). ALP activity was detected by immunofluorescence staining. The ST2 cells were cultured with SP, Noggin (inhibitor of the bone morphogenetic protein signaling pathway), SP+Noggin, and 2% fetal bovine serum, respectively. Finally, the expression of ALP, CollaⅠ, and OCN in the culture supernatant was tested by ELISA.</p><p><b>RESULTS</b>CCK-8 showed that the effect of cell proliferation was most obvious when the SP concentration was 10⁻⁶ mol·L⁻¹ (P<0.01). The ELISA results demonstrated that ALP expression significantly increased at day 5 compared with that in the control group (P<0.01), whereas the expression of CollaⅠand OCN significantly increased at day 7 (P<0.05). Immunofluorescence results showed that ALP activity was strongest at day 5. The expression of ALP, CollaⅠ, and OCN decreased after Noggin addition (P<0.05).</p><p><b>CONCLUSIONS</b>SP can promote the proliferation and osteogenic differentiation of ST2 cells, and the bone morphogenetic protein signaling pathway may be involved in this process.</p>
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Bone mesenchymal stem cells (BMSCs) have been used worldwide to treat spinal cord injury, but their therapeutic mechanism is poorly understood. In this study, BMSCs were transplanted to aneurysm clip-injured rats to demonstrate their protective effect. We observed myelin sheaths through Luxol fast blue (LFB) staining, osmic acid staining, TUNEL and transmission electron microscopy (TEM). We performed Western blotting to analyze the expressions of brain-derived neurotrophic factor (BDNF) and caspase 3. BMSCs were transplanted at 1, 7 and 14 days after spinal cord injury. Hindlimb movement (Basso, Beattie and Bresnahan; BBB) score, CNPase (2', 3'-cyclic-nucleotide 3'-phosphodiesterase), myelin basic protein (MBP) and caspase 3 protein levels were detected. Immunofluorescence was used to test the differentiation of BMSCs after implanted into damaged spinal cord and co-expression of CNPase-caspase 3+. At 7 days after BMSCs transplantation, some injected BMSCs expressed neuronal and oligodendrocyte markers. And both locomotor skills and ultra-structural features of myelin sheaths were significantly improved. The expressions of BDNF were clearly increased by BMSCs transplantation, the expression of caspase 3 was the opposite. Compared with the 1 and 14 days transplantation after spinal cord injury, MBP and CNPase expressions were highest, caspase 3 expression was lowest in 7 days BMSCs transplantation. After BMSCs transplantation, CNPase-caspase 3+ cells scattered in the white matter of the spinal cord. Therefore, BMSCs had a tendency to differentiate into neurons and oligodendrocytes after transplantation, which could promote the secretion of BDNF. BMSCs protected neural myelin sheaths by inhibiting oligodendrocyte apoptosis via increased secretion of BDNF after SCI. The best therapeutic time was 7 days after spinal cord injury.
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Objective To observe the phenotypic transformation of bone marrow mesenchymal stem cells(MSC) transfected with hepatocyte growth factor(HGF) after their transplantation in the rat's kidney with partial unilateral ureteral obstruction(PUUO).Methods We isolated,cultured bone MSCs of the male rats,and transfected them with Ad-HGF in vitro.Thirty-six female rats with PUUO were randomly divided into control group(A) and the experimental groups(B,C).Saline,Ad-GFP transfected MSCs or Ad-HGF transfected MSCs were respectively injected into the parenchyma of kidney on the 7th day with PUUO.We released the ureteral obstruction of rats after transplantation.Kidney tissue of the rats were collected on the 7th day after transplantation.The distribution and phenotypic transformation of MSCs in the kidney were determined by immunofluorescence method.Results The green fluorescent-labeled MSCs mainly distributed in the tubular cells,and a part of bone MSCs underwent phenotypic transformation after transplantation.Compared with group B,the number of bone MSCs with phenotypic transformation significantly increased in group C.Conclusion After transplantation,MSCs can survive and differentiate into renal tubular epithelial cells,and HGF may promote survival and differentiation of MSCs.
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Objective@#To investigate the role of bone marrow mesenchymal stem cells (BMSCs) with CTLA4Ig and CD40LIg gene modification in rejection reaction after liver transplantation in rats and possible mechanisms.@*Methods@#The modified Kamada’s two-cuff technique was used to establish a Lewis-BN rat model of orthotopic liver transplantation, and a total of 75 rats were randomly divided into groups A, B, C, D, and E, with 15 rats in each group. The rats in group A (control group) were given infusion of isotonic saline via the portal vein during liver transplantation, those in group B (BMSC group) were given infusion of BMSCs via the portal vein during liver transplantation, those in group C (BMSCs with CTLA4Ig gene modification) were given infusion of BMSCs carrying the CTLA4Ig gene via the portal vein during liver transplantation, those in group D (BMSCs with CD40LIg gene modification) were given infusion of BMSCs carrying the CD40LIg gene via the portal vein during liver transplantation, and those in group E (BMSCs with CTLA4Ig and CD40LIg gene modification) were given infusion of BMSCs carrying CTLA4Ig and CD40LIg gene modification via the portal vein during liver transplantation. Postoperative survival and change in liver function were observed. HE staining was used to observe the pathomorphological changes of the graft liver, and ELISA was used to measure the levels of interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-10 (IL-10), and interferon-γ (IFN-γ) in peripheral blood. A one-way analysis of variance was used for comparison of means of multiple samples, and the Kaplan-Meier survival curve analysis was used for comparison of survival rates between multiple groups.@*Results@#Group E had a significantly longer survival time after surgery than groups A, B, C, and D (P < 0.05), groups C and D had a significantly longer survival time than groups A and B (P < 0.05), and there was no significant difference between groups C and D (P > 0.05). On day 10 after surgery, group A had significantly higher levels of alanine aminotransferase and total bilirubin than the other four groups (P < 0.05). HE staining showed severe rejection reaction in group A, moderate rejection reaction in group B, and mild rejection reaction in groups C and D; pathological examination showed no marked rejection reaction in group E. Group A had significant increases in the levels of IL-2 and IFN-γ and significant reductions in the levels of IL-4 and IL-10 after surgery compared with the other four groups (all P < 0.05).@*Conclusion@#Infusion of BMSCs with modification of both CTLA4Ig and CD40LIg genes can significantly inhibit acute rejection reaction after liver transplantation in rats and effectively prolong the survival time of the graft liver, with a better effect than infusion of BMSCs alone or BMSCs with modification of CTLA4Ig or CD40LIg gene.
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Cells are exposed to mechanical stress, such as fluid shear stress (FSS), mechanical strain, hydrostatic pressure in vivo. FSS is considered to be the most important stress during bone homeostasis and remodeling. At present, most studies are mainly about the FSS effect on osteocytes and osteoblasts. However, the effects of FSS on bone mesenchymal stem cell (BMSCs) are not fully understood. BMSCs are of great significance in bone reconstruction and clinical treatment, so researchers increasingly focus on the response of BMSCs to FSS. The response of BMSCs to FSS depends on the alteration of cytoskeleton, matrix stiffness and elasticity, osteogenic signaling pathways and so on. In this review paper, the recent researches about the mechanotransduction mechanism of FSS, and its effect on differentiation and function of BMSCs are summarized, so as to provide new insights for studying construction of tissue engineered bone and treatment of bone diseases.
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Objective To establish a rat model of glucocorticoid-induced osteoporosis(GIOP)and to explore the interventional effect of the Chinese medicine Fufang Zhenzhu Tiaozhi(FTZ)capsules on regulation of mitogen-activated protein kinase kinase kinase 2(MEKK2)-Wnt coupling and inhibiting β-catenin ubiquitination, and to investigate the effect of FTZ on the bone mineral density and cell osteogenic ability. Methods SPF male rats were randomly divided into normal control group,methylprednisolone group(model group),methylprednisolone + saline group(blank control group) and methylprednisolone + FTZ group(experimental group). The proximal femoral cancellous bone was examined by mi-cro-CT and histopathology,and assessment of expressions of Wnt3a,MEKK2,and β-catenin proteins. Bone mesenchymal stem cells(BMSCs were isolated and treated with serum containing FTZ,stained by alkaline phosphatase and alizarin red. The expressions of osteogenic differentiation-related genes ALP,Runx2 and OCN,the expressions of MEKK2 and β-catenin proteins,and the transcription level of β-catenin/TCF were determined. Results 1)The micro-CT imaging showed that compared with the control group, the BV/TV, Tb.Th and Tb/N expressions were significntly decreased, and Tb/sp in-creased in the experimental group(P<0.05). Region of interest(ROI)three-dimensional reconstruction of trabecular bone in the experimental group showed improvement of bone trabeculae and local bone repair. 2)The pathology using he-matoxylin and eosin staining showed that in the experimental group,the bone trabecular density was higher than that of the model group,and observed a better trabecula morphology. 3)The Wnt3a,MEKK2 and β-catenin expressions in the exper-imental group were significantly increased compared with the model model(P<0.05). 4)After treated with FTZ and BMP2,the result of alkaline phosphatase and alizarin red staining indicated an enhanced osteogenic response(P<0.05) in the GIOP rat models. 5)After treatment with seum containing FTZ,The BMSCs isolated from the GIOP rats enhanced the transcriptional activity of β-catenin/TCF/LEF(P<0.05)and promoted the expression of β-catenin and MEKK2 pro-teins(P<0.05). Conclusions FTZ can ameliorate GIOP by regulating the MEKK2-Wnt coupling and inhibiting the β-catenin ubiquitination,and improve the bone microstructure.
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Exosomes are small vesicles that are released from multivesicular bodies to the extracellular. They can carry proteins, lipids, DNA, miRNA and mRNA to the recipient cells, thereby altering the biological behavior of the recipient cells. In multiple myeloma (MM), exosomes could regulate the immune system, promote angiogenesis and the transformation of cancer-associated fibroblasts, interact with bone mesenchymal stem cells, enhance osteoclast activity, and induce MM resistance. Exosomes in the blood can be used as an early diagnostic marker for MM in order to provide a new diagnosis and treatment strategy for MM patients. This article summarizes the progress of the function, diagnosis and treatment of exosomes in MM.
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Objective To study whether the human bone marrow mesenchymal stem cells (HBMSCs) can repair damaged neural cells induced by okadaic acid (OA).Methods Neuroblastoma cell line SH-SY5Y cells were used to incubate with 20nmol/L okadaic acid for 24h,establishing Alzheimer's Disease cell model;Three groups were set up:normal group,okadaic acid-damaged (OA-damaged) group,hBMSCs-treatment group.The cells were injured for 24h with 20nmol/L OA in OA-damaged group,and treated with conditioned medium obtaining hBMSCs for 24h after 24h OA injury in the treatment group.Then CCK-8 was used for detecting cell vitality,immune fluorescence dyed microtubules and micro filaments for determining the dendritic cell length and fluorescence intensity,in addition,Western blotting for analyzing the protein level of phosphorylated tau and total tau proteins.Results Okadaic acid damaged SH-SY5Y cells,contributed to shrinkage,collapse,cavitation of the SH-SY5Y cell body,dendritic shortening and fracture,and irregular arrangement of microtubule microfilaments;while BMSCs conditioned medium made SHSYSY cell body become round and longer,dendrites restored,and microtubules and microfilaments arranged regularly,fluorescence intensity enhanced.Meanwhile,it also down-regulated the level of OA-induced tau phosphorylation.Conclusion hBMSCs have repair effects on the neural cell damage induced by okadaic acid.
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Orthodontic tooth movement is a dynamic process,which includes bone resorption on the pressure side and osteogenesis on the tension side.Bone mesenchymal stem cells (BMSCs),which are force-sensitive cells,have potentials for differentiation into cells with various types.Their biological characteristics can change functionally according to the appropriate stimulation in vitro,in order to reach the optimal demand of the stimulation.Many signal pathways are involved in osteogenesis.Signal transducers and activators of transcription 3 (STAT3) is a ubiquitously expressed transcription factor,mediating cell proliferation,differentiation,survival,apoptosis and cellular immunity.It has been reported that STAT3 can regulate the differentiation process of BMSCs into osteoblasts.This paper summarizes the recent progress about effect of STAT3 on bone differentiation of BMSCs and the possible mechanism.
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Objective@#To investigate the effect of polydimethylsiloxane (PDMS) matrix elasticity on osteogenic differentiation of rat marrow stromal cells (rBMSC).@*Methods@#A series of PDMS composite substrates with different elastic modulus were constructed by adjusting the relative concentrations of cross-linking agent. The Young's modulus was used to describe the elasticity of PDMS after measurement by atomic force microscope (AFM). After surface modification, rBMSC was seeded on PDMS matrix, and 7 days after rBMSC was cultured on the five different Young's moduli matrix, the differences of osteogenic differentiation of rBMSC were observed by the method of real-time PCR, Western blotting, and alkaline phosphatase assay.@*Results@#The PDMS was suitable for cell culture after surface modification, and by altering the concentration of cross-linking agent, PDMS could mimic the majority of the tissues' elasticity in vivo. The related osteogenic differentiation markers expression showed significant difference between the five matrixes (P<0.05), including type Ⅰ collagen (Col-Ⅰ), osteocalcin (OCN), osteopontin (OPN) and bone morphogenetic protein 2 (BMP2). The expression of osteogenic markers was up-regulated in the group that the Young's modulus was (354.1±40.9) kPa (P<0.05).@*Conclusions@#PDMS is a tunable elasticity matrix which could be used in the investigation of inducing rBMSCs into osteoblastic lineages. PDMS substrate stiffness has an obvious influence on rBMSC osteogenic differentiation.