【Abstract】 Objective Sonic hedgehog (Shh) signaling pathway is involved in an important part of regulating angiogenesis. To investigate the effects of recombinant Shh N-terminant (rShh-N) on the expression and secretion of angiogenesis-related factor—vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Methods Bone marrow mesenchymal stem scells (BMSCs) were isolated from 3-day-old healthy Sprague Dawley rats and cultured to passage 3 in vitro. rShh-N at the concentrations of 0, 10, 100, and 200 ng/mL were applied to culture BMSCs in groups A, B, C, and D, respectively. At 12, 24, 48, and 72 hours of culture, the expressions of VEGF and bFGF mRNA and the levels of VEGF and bFGF in supernatant were measured with real-time quantitative PCR and ELISA, respectively. Results At the gene level, compared with group A, the expressions of VEGF and bFGF mRNA were enhanced in group D (P lt; 0.05) and the upregulation was more significant at 12 and 48 hours than 24 and 72 hours (P lt; 0.01). In group C, bFGF mRNA expression was substantially promoted at 12-72 hours (P lt; 0.05) and VEGF mRNA level was upregulated at 24-72 hours (P lt; 0.05), and both reached peak at 72 hours (P lt; 0.01). In group B, VEGF mRNA expression was inhibited at 12 hours (P lt; 0.05), but the level increased at 48 and 72 hours (P lt; 0.05); bFGF mRNA expression was obviously promoted at 12-48 hours (P lt; 0.05) and the maximum appeared at 48 hours (P lt; 0.01). At the protein level, the secretion of VEGF and bFGF in group D was significantly increased at 12-72 hours, as compared with group A (P lt; 0.05). In group C, VEGF and bFGF secretion was increased at 24-72 hours (P lt; 0.05). The secretion of VEGF in group B was inhibited at 12 and 48 hours (P lt; 0.05) and was promoted at 24 hours (P lt; 0.05); bFGF secretion was up-regulated at 24 and 48 hours (P lt; 0.05). The secretion of VEGF and bFGF in supernatant at 【Abstract】 Objective Sonic hedgehog (Shh) signaling pathway is involved in an important part of regulating angiogenesis. To investigate the effects of recombinant Shh N-terminant (rShh-N) on the expression and secretion of angiogenesis-related factor—vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Methods Bone marrow mesenchymal stem scells (BMSCs) were isolated from 3-day-old healthy Sprague Dawley rats and cultured to passage 3 in vitro. rShh-N at the concentrations of 0, 10, 100, and 200 ng/mL were applied to culture BMSCs in groups A, B, C, and D, respectively. At 12, 24, 48, and 72 hours of culture, the expressions of VEGF and bFGF mRNA and the levels of VEGF and bFGF in supernatant were measured with real-time quantitative PCR and ELISA, respectively. Results At the gene level, compared with group A, the expressions of VEGF and bFGF mRNA were enhanced in group D (P lt; 0.05) and the upregulation was more significant at 12 and 48 hours than 24 and 72 hours (P lt; 0.01). In group C, bFGF mRNA expression was substantially promoted at 12-72 hours (P lt; 0.05) and VEGF mRNA level was upregulated at 24-72 hours (P lt; 0.05), and both reached peak at 72 hours (P lt; 0.01). In group B, VEGF mRNA expression was inhibited at 12 hours (P lt; 0.05), but the level increased at 48 and 72 hours (P lt; 0.05); bFGF mRNA expression was obviously promoted at 12-48 hours (P lt; 0.05) and the maximum appeared at 48 hours (P lt; 0.01). At the protein level, the secretion of VEGF and bFGF in group D was significantly increased at 12-72 hours, as compared with group A (P lt; 0.05). In group C, VEGF and bFGF secretion was increased at 24-72 hours (P lt; 0.05). The secretion of VEGF in group B was inhibited at 12 and 48 hours (P lt; 0.05) and was promoted at 24 hours (P lt; 0.05); bFGF secretion was up-regulated at 24 and 48 hours (P lt; 0.05). The secretion of VEGF and bFGF in supernatant at
ObjectiveTo investigate the effect of transforming growth factorβ1 (TGF-β1) and basic fibroblast growth factor 1 (bFGF-1) on the cellular activities, prol iferation, and expressions of ligament-specific mRNA and proteins in bone marrow mesenchymal stem cells (BMSCs) and ligament fibroblasts (LFs) after directly co-cultured.
MethodsBMSCs from 3-month-old Sprague Dawley rats were isolated and cultured using intensity gradient centrifugation. LFs were isolated using collagenase. The cells at passage 3 were divided into 6 groups: non-induced BMSCs group (group A), non-induced LFs group (group B), non-induced co-cultured BMSCs and LFs group (group C), induced BMSCs group (group D), induced LFs group (group E), and induced co-cultured BMSCs and LFs group (group F). The cellular activities and prol iferation were examined by inverted contrast microscope and MTT; the concentrations of collagen type Ⅰ and type Ⅲ were determined by ELISA; and mRNA expressions of collagen types I andⅢ, fibronectin, tenascin C, and matrix metalloproteinase 2 (MMP-2) were measured by real-time fluorescent quantitative PCR.
ResultsA single cell layer formed in the co-cultured cells under inverted contrast microscope. Group F had fastest cell fusion ( > 90%). The MTT result indicated that group F showed the highest absorbance (A) value, followed by group D, and group B showed the lowest A value at 9 days after culture, showing significant difference (P < 0.05). Moreover, the result of ELISA showed that group F had the highest concentration of collagen type Ⅰ and type Ⅲ (P < 0.05); the concentration of collagen type Ⅲ in group E was significantly higher than that in group D (P < 0.05), but no significant difference was found in the concentration of collagen type Ⅰ between 2 groups (P > 0.05). The ratios of collagen type Ⅰ to type Ⅲ were 1.17, 1.19, 1.10, 1.25, 1.17, and 1.18 in groups A-F; group D was higher than the other groups. The real-time fluorescent quantitative PCR results revealed that the mRNA expressions of collagen type Ⅰ and type Ⅲ and fibronectin were highest in group F; the expression of tenascin C was highest in group D; the expression of MMP-2 was highest in group E; and all differencs were significant (P < 0.05).
ConclusionDirectly co-cultured BMSCs and LFs induced by TGF-β1 and bFGF-1 have higher cellular activities, proliferation, and expressions of ligament-specific mRNA and protein, which can be used as a potential source for ligament tissue engineering.
Objective To compare the growth and extracellular matrix biosynthesis of nucleus pulposus cells (NPCs)and bone marrow mesenchymal stem cells (BMSCs) in thermo-sensitive chitosan hydrogel and to choose seed cells for injectable tissue engineered nucleus pulposus. Methods NPCs were isolated and cultured from 3-week-old New Zealand rabbits (male or female, weighing 150-200 g). BMSCs were isolated and cultured from bone marrow of 1-month-old New Zealand rabbits (male or female, weighing 1.0-1.5 kg). The thermo-sensitive chitosan hydrogel scaffold was made of chitosan, disodium β glycerophosphate, and hydroxyethyl cellulose. Then, NPCs at the 2nd passage or BMSCs at the 3rd passage were mixed with chitosan hydrogel to prepare NPCs or BMSCs-chitosan hydrogel complex as injectable tissue engineered nucleus pulposus. The viabil ities of NPCs and BMSCs in the chitosan hydrogel were observed 2 days after compound culture. The shapes and distributions of NPCs and BMSCs on the scaffold were observed by scanning electron microscope (SEM) 1 week after compound culture. The histology and immunohistochemistry examination were performed. The expressions of aggrecan and collagen type II mRNA were analyzed by RT-PCR 3 weeks after compound culture. Results The thermo-sensitive chitosan hydrogel was l iquid at room temperature and sol idified into gel at37 (after 15 minutes) due to crossl inking reaction. Acridine orange/propidium iodide staining showed that the viabil ity rates of NPCs and BMSCs in chitosan hydrogel were above 90%. The SEM observation demonstrated that the NPCs and BMSCs distributed in the reticulate scaffold, with extracellular matrix on their surfaces. The results of HE, safranin O histology and immunohistochemistry staining confirmed that the NPCs and BMSCs in chitosan hydrogel were capable of producing extracellular matrix. RT-PCR results showed that the expressions of collagen type II and aggrecan mRNA were 0.564 ± 0.071 and 0.725 ± 0.046 in NPCs culture with chitosan hydrogel, and 0.713 ± 0.058 and 0.852 ± 0.076 in BMSCs culture with chitosan hydrogel; showing significant difference (P lt; 0.05). Conclusion The thermo-sensitive chitosan hydrogel has good cellular compatibil ity. BMSCs culture with chitosan hydrogel maintains better cell shape, prol iferation, and extracellular matrix biosynthesis than NPCs.
Objective
To observe the effect of bone marrow mesenchymal stem cells (BMSCs) conditioned medium on microglia (MGs) and its secretion of arginase 1 (Arg1).
Methods
The BMSCs separated through differential adhesion method from the femur and tibia marrow of 4-week-old Sprague Dawley (SD) rats were cultured and identified by Vimentin immunofluorescence staining; whereas MGs separated through trypsin digestion method from the brain of 3-day-old SD rats were cultured and identified by Iba1 immunofluorescence staining. The primary MGs were cultured with DMEM/F12 medium containing BMSCs conditioned medium (experimental group) and with single DMEM/F12 medium (control group), respectively. After 48 hours of culture, the morphology of MGs was observed by inverted phase contrast microscope, the activated state of MGs was detected by using Iba1 immunofluorescence staining, and Arg1 expression of MGs was assessed by Iba1-Arg1 double-labelling immunofluorescence staining and Western blot method.
Results
Inverted phase contrast microscope observation showed that BMSCs entered logarithmic growth phase at 14 days after culture, and more than 98% cells were positive to Vimentin immunofluorescence staining; whereas MGs entered logarithmic growth phase at 21 days after culture, and around 80% cells were positive to Iba1 immunofluorescence staining. Inverted phase contrast microscope observation displayed that in the experimental group, MGs were activated with increased size of soma, shortened process, and amoeba change. Immunofluorescence staining displayed that the Iba1 positive cells number in the experimental group was significantly higher than that in the control group (t=0.007, P=0.000); double-labelling immunofluorescence staining revealed that the Iba1-Arg1 positive cells number in the experimental group was significantly higher than that in the control group (t=0.007, P=0.000); and Western blot results elucidated that the relative expression of Arg1 protein in the experimental group was significantly higher than that in the control group (t=0.001, P=0.000).
Conclusion
BMSCs conditioned medium can activate MGs and induce MGs to express Arg1.
ObjectiveTo study the effect of Triton X-100 promoting liposome-mediated bone morphogenetic protein 2 (BMP-2) gene transfection of rat bone marrow mesenchymal stem cells (BMSCs).
MethodsBMSCs were separated and cultured from the femur and tibia of healthy Wistar rats (8-week-old, male). The 3rd passage BMSCs identified by detecting the surface antigen were used to transfect. The optimum concentration of Triton X-100 for liposome mediated gene transfection was determined with ELISA meter by the way of MTT. In optimum concentration of Triton X-100, liposome mediated BMP-2 gene was transfected to BMSCs. The experiment was divided into 3 groups according to types of trasfection agents:BMSCs were transfected with Triton X-100+liposome+BMP-2 (experimental group), with liposome+ BMP-2 (conventional transfection group), and untransfected BMSCs served as blank control group. After 48 hours of transfecting, the green fluorescent protein (GFP) in cells was detected through inverted fluorescence microscope. After 72 hours of transfection, real-time fluorescence quantitative PCR was applied to measure the mRNA expression of BMP-2.
Results0.01% Triton X-100 was determined to be the optimum concentration for not only making the BMSCs maintain vitality, but also achieving a certain effect on BMSCs. After trasfecting for 48 hours, GFP was observed through inverted fluorescence microscope in the experimental group and conventional transfection group, but was not observed in the blank control group. After trasfecting for 72 hours, the relative BMP-2 mRNA expression level was 5.94±0.12 in the experimental group, and was 4.99±0.08 in the conventional transfection group, showing significant difference (t=360.28, P=0.02). The transfection efficiency was increased by 19% in the experimental group.
Conclusion0.010%Triton X-100 can promote the liposome mediated BMP-2 gene transfection of rat BMSCs, and can improve the transfection efficiency.
ObjectiveTo review the research progress of different cell seeding densities and cell ratios in cartilage tissue engineering. MethodsThe literature about tissue engineered cartilage constructed with three-dimensional scaffold was extensively reviewed, and the seeding densities and ratios of most commonly used seed cells were summarized. ResultsArticular chondrocytes (ACHs) and bone marrow mesenchymal stem cells (BMSCs) are the most commonly used seed cells, and they can induce hyaline cartilage formation in vitro and in vivo. Cell seeding density and cell ratio both play important roles in cartilage formation. Tissue engineered cartilage with good quality can be produced when the cell seeding density of ACHs or BMSCs reaches or exceeds that in normal articular cartilage. Under the same culture conditions, the ability of pure BMSCs to build hyaline cartilage is weeker than that of pure ACHs or co-culture of both. ConclusionDue to the effect of scaffold materials, growth factors, and cell passages, optimal cell seeding density and cell ratio need further study.
ObjectiveTo investigate the regulatory effect of simvastatin on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) at middle/late stages by p38MAPK pathway under condition of osteoinductive environment.
MethodsThe bone marrow of bilateral femur and tibia were harvested from 20 4-week-old female Sprague Dawley rats. BMSCs were isolated and cultured with whole bone marrow culture method; the second generation of cells were randomly divided into 5 groups: control group (complete medium, CM), simvastatin group (simvastatin medium, SIM), osteogenic induction group (osteogenic induction medium, OM), simvastatin and osteogenic induction group (simvastatin+osteogenic induction medium, OM+SIM), and blocker group (SB203580+simvastatin+osteogenic induction medium, OM+SIM+SB). MTT assay was used to detect the cell activity in CM group and SIM group at 2, 3, 4, 5, and 6 days, ELISA method to measure the content of alkaline phosphatase (ALP) in OM group and OM+SIM group at 7 and 14 days. The mRNA and protein expressions of osteocalcin (OCN) were detected by real-time quatitative PCR and Western blot after 1, 12, and 24 hours of osteogenic induction at 21 and 28 days. The protein expressions of phospho-p38 (p-p38) and p38 in OM group, OM+SIM group, and OM+SIM+SB group were detected by Western blot at the best induction time of simvastatin.
ResultsMTT assay showed that no significant difference was found in absorbance (A) value between CM group and SIM group at each time point (P > 0.05), indicating no effect of 1×10-7 mol/L simvastatin on cell viability. ELISA results showed that ALP content significantly increased in OM+SIM group when compared with OM group at 7 and 14 days; the ALP content was significantly higher at 7 days than 14 days in OM group and OM+SIM group (P < 0.05). OCN mRNA and protein expressions at 12 hours were significantly higher than those at other time points in each group (P < 0.05), and the expressions of OM+SIM group was significantly higher than those of OM group (P < 0.05). The best induction time of simvastatin was 12 hours. At 12 hours after blocking intervention, the p-p38/p38 in OM+SIM+SB group was significantly lower than that in OM group and OM+SIM group (P < 0.05), and the p-p38/p38 in OM+SIM group was significantly higher than that in OM group (P < 0.05).
ConclusionSimvastatin can increase the mRNA and protein expression levels of OCN and the protein of p-p38 in osteogenic differentiation of BMSCs at middle/ late stages, and its best induction time is 12 hours.
ObjectiveTo explore the effects of interleukin 10 (IL-10) gene modified bone marrow mesenchymal stem cells (BMSCs) on the expression of inflammatory cytokines and neuronal apoptosis in rats after cerebral ischemia reperfusion injury.MethodsBMSCs were cultured by whole bone marrow adherence screening method. The properties of BMSCs were identified by immunocytochemical methods. BMSCs at passage 3 were transfected with recombinant adenovirus IL-10 gene (AdIL-10-BMSCs). The model of middle cerebral artery occlusion was made in 40 adult male Sprague Dawley rats by thread embolism method. The rats were randomly divided into 4 groups (n=10). At 3 hours after modelling, the rats of groups A, B, C, and D received tail intravenous injection of 1 mL L-DMEM medium containing 10% FBS, 61.78 ng IL-10, 1 mL BMSCs suspension (2×106 cells/mL), and 1 mL AdIL-10-BMSCs cell suspension (2×106 cells/mL), respectively. The cells were labelled with BrdU before cell transplantation in groups C and D. At 7 days after reperfusion, the brain tissue was harvested to detect the expression of OX42 by immunohistochemical assay, to determine the concentration of tumor necrosis factor α (TNF-α) and IL-1β by ELISA, and to detect the apoptosis by TUNEL assay. BrdU labelled cells were observed by immunofluorescence staining in groups C and D.ResultsBrdU labelled positive cells with green fluorescence were observed in the brain tissue of groups C and D, which mainly distributed in the striatum, cerebral cortex, and subcortex around the infarction area. The number of OX42 positive cells was significantly less in groups B, C, and D than group A (P<0.05), and in group D than groups B and C (P<0.05). Compared with the other 3 groups, the contents of TNF-α and IL-1β significantly decreased in group D (P<0.05). TUNEL assay showed that the apoptotic cells (TUNEL positive cells) were mainly seen in the striatum and fronto parietal subcortical tissues (equivalent to ischemic penumbra). The number of TUNEL positive cells in group D was significantly less than that in groups A, B, and C (P<0.05).ConclusionAdIL-10-BMSCs can inhibit secretion of TNF-α and IL-1β from microglial cells and inhibit the nerve cell apoptosis around infarct brain tissue, which might contribute to its protective role upon cerebral ischemia reperfusion injury.
Objective To elucidate whether glucose transporters-4 （GLUT-4） takes part in glucose uptake of mesenchymal stem cells （MSCs） and whether Akt gene improves translocation and expression of GLUT-4 in MSCs under hypoxic environment ex vivo. Methods MSCs, transfected by Akt gene and no, were cultured with normoxia (5% CO2) or hypoxia (94%N2, 1%O2 and 5% CO2) at 37 ℃ for 8 h. Glucose uptake was assayed by using radiation isotope 2-［3H］-deoxy-Dglucose (3H-G) and the expression of GLUT-4 protein and mRNA was assayed by immunocytochemistry, Western blot and RT-PCR, respectively. Results ①3 H-G intake of MSCs was significantly increased in hypoxiatransfection group than that in hypoxia-non-transfection 〔（1.39±0.13） fold, P＜0.05〕, but which was lower than that in normoxia-non-transfection group, P＜0.05. ②GLUT-4 was expressed by MSCs under any conditions. Compared with normoxia-non-transfection group, hypoxia decreased the expressions of GLUT-4 mRNA and protein significantly (P＜0.05). ③Compared with hypoxianontransfection group, the expression of GLUT-4 〔mRNA（1.756±0.152） fold, total protein in cell （1.653±0.312） fold, protein in plasma membrane （2.041±0.258） fold〕 was increased in hypoxia-transfection group significantly (P＜0.05), but which was lower than that in normoxianontransfection group (P＜0.05). ④There was significantly positive relation between 3H-G intake and GLUT-4 protein expression in plasma membrane (r=0.415, P=0.001).Conclusion GLUT-4 may take part in glucose uptake of MSCs, and the capability of Akt gene to improve MSCs anti-hypoxia may be finished by its role in increasing the expression and translocation of GLUT-4.
ObjectiveTo investigate the effect of diammonium glycyrrhizinate (DG) plus bone marrow mesenchymal stem cells (MSCs) transplantation in the treatment of acute exacerbation of pulmonary fibrosis induced by bleomycin (BLM) in rats.MethodsMSCs were isolated from male Wistar rats and cultured in vitro. Twenty-four female Wistar rats were randomly divided into 4 groups. The NC group was intratracheally injected with normal saline; the BLM group, the MSC group and the DGMSC group were intratracheally injected with BLM for 7 days; then the MSC group was injected with 0.5 mL of MSCs solution (2.5×106 cells) into the tail vein; the DGMSC group was intraperitoneally injected with DG for 21 days in a dose of 150 mg·kg–1·d–1 on the base of the MSCs injection. The rats were sacrificed on the 28th day and the lung tissue was extracted. Pathological examination was performed to determine the degree of alveolitis and pulmonary fibrosis. Immunofluorescence was used to detect the number and distribution of alveolar type Ⅱ epithelial cells. Alkali hydrolysis method was used to determine the content of hydroxyproline (HYP) in lung tissue; thiobarbituric acid method was used to measure the content of malondialdehyde (MDA) in lung tissue; colorimetric method was used to determine the superoxide dismutase activity (SOD) and total antioxidant capacity (T-AOC); enzyme linked immunosorbent assay was used to detect the expression levels of tumor necrosis factor-α (TNF-α ) and transforming growth factor-β1 (TGF-β1) in lung tissue homogenates.ResultsThe DG combined with MSCs injection can reduce the degree of alveolitis and pulmonary fibrosis in BLM model rats. The content of HYP and TGF-β1 in lung tissue homogenate of the DGMSC group were significantly lower than those in the MSC group (P<0.05). Meanwhile, DG combined with MSCs injection significantly increased the antioxidant capacity of the BLM model rats. MDA content decreased, SOD activity and T-AOC ability improved significantly in the DGMSC group compared with the MSC group (P<0.05). The alveolar type Ⅱ epithelial cells were significantly increased and the cell morphology was maintained in the DGMSC group compared with the MSC group.ConclusionsDG has a synergistic effect with MSCs in treatment of acute exacerbation of pulmonary fibrosis. The mechanism may be related to reducing inflammatory factors during pulmonary fibrosis, attenuating oxidative stress and promoting MSCs migration into lung tissue and transformation to alveolar type Ⅱ epithelial cells.
