【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
Spinal cord injury (SCI) is a complex pathological process. Based on the encouraging results of preclinical experiments, some stem cell therapies have been translated into clinical practice. Mesenchymal stem cells (MSCs) have become one of the most important seed cells in the treatment of SCI due to their abundant sources, strong proliferation ability and low immunogenicity. However, the survival rate of MSCs transplanted to spinal cord injury is rather low, which hinders its further clinical application. In recent years, hydrogel materials have been widely used in tissue engineering because of their good biocompatibility and biodegradability. The treatment strategy of hydrogel combined with MSCs has made some progress in SCI repair. This review discusses the significance and the existing problems of MSCs in the repair of SCI. It also describes the research progress of hydrogel combined with MSCs in repairing SCI, and prospects its application in clinical research, aiming at providing reference and new ideas for future SCI treatment.
ObjectiveTo investigate the multi-directional differentiation potential and other biological characteristics of chicken umbilical cord mesenchymal stem cells (UMSC), as well as their reparative effects on bleomycin (BLM)-induced lung injury in mice. MethodsAn acute lung injury model in mice was established by injecting BLM into the bronchus. UMSC were then transplanted via the tail vein. The reparative effects of UMSC on lung injury were evaluated through pathological section observation, survival and differentiation of transplanted cells in mice, and detection of hydroxyproline (HYP) content, among other indicators. ResultsThe UMSC successfully isolated in this study positively expressed specific surface markers CD29, CD44, CD90, and CD166, while the expression of CD34 and CD45 was negative. Induced UMSC could differentiate into adipocytes, osteocytes, chondrocytes, and alveolar epithelial cells. Animal experiments revealed that BLM-treated mice exhibited damaged alveolar structures, significant inflammatory cell infiltration, abnormal collagen deposition, and pulmonary fibrosis. However, after UMSC transplantation, the extent and severity of lung damage were reduced, and the HYP content in lung tissue decreased but remained higher than that of the control group. ConclusionUMSC can continuously proliferate and maintain their biological characteristics under in vitro culture conditions. They possess the ability to migrate to damaged sites and undergo directional differentiation, demonstrating a certain reparative effect on BLM-induced acute lung injury in mice.
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 establish a better method of isolating andculturing ofneural stem cells(NSCs) in neonatal rat brain. Methods Tissue of brain was isolated from neonatal rats. Different medium and culture concentration were used toculture NSCs of neonatal rat. The culture concentration used were 1×10 4, 1×105, 1×106and 1×107/ml respectively. Ingredient of medium was classified into group 1 to 8 respectively according to whether to add 2% B27, epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) as well as the difference in culture concentration. The cells were induced to differentiate asto be confirmed as NSCs, and then were checked by phase contrast microscopy and identified by immunocytochemistry. Results The cells isolated and cultured gathered into neurospheres. The cells were capable of proliferating and maintaining longterm survival in vitro. The cells could be differentiated into neurons and glia.It was to the benefit of the survival of NSCs to add 5% fetal bovine serum(FBS)into the medium at the beginning of the culturing. When 10% FBS was added intothe medium, the neurospheres differentiated quickly. When concentration 1×106/ ml was used, the growth rate of the cells was the highest of all the concentrations. Reasonably higher cell concentration promoted the proliferation of NSCs. It was necessary to add 2% B27, EGF, and bFGF into the medium. The cells had the best growth when 2% B27, 20 ng/ml bFGF and 20 ng/ml EGF were added into the culture medium. EGF and bFGF had cooperative effect. Conclusion A better method of isolating and culturing of NSCs in neonatal rat brain is established and the foundation for future research is laid.
Objective To establish a model of the human marrow mesenchymal stem cells (hMSCs) cultured under the hypoxic condition in adults and to investigate the biological features of MSCs under hypoxia.Methods The bone marrow was obtained by aspiration at the posterior superior iliac spine in 3 healthy adult subjects. hMSCs were isolated by the gradient centrifugation and were cultured in the DMEM-LG that contained 20％ fetal bovine serum. The serial subcultivation was performed 10-14 days later. The second passage of the hMSCs were taken, and they were divided into the following 4 groups according to the oxygen concentrations and the medium types: the normoxic group（20％O2, DMEM-LG, Group A）, the hypoxic group（1％O2, DMEM-LG,Group B）, the normoxic osteoblast induction group（20％O2, conditioned medium, Group C）, and the hypoxic osteoblast induction group（1％O2, conditioned medium, Group D）. The biological features of the cultured hMSCs under hypoxia were assessed bythe cell count, the MTT method, the colony forming unit-fibroblast, the real-time RT-PCR, and the alkaline phosphatase (ALP) activity, and the alizarinred staining. Results The hMSCs cultured in the Group B and Group D had a significantly higher proliferation rate than those in the Group A (Plt;0.01), and the culture effect was not influenced by the medium type. The hMSCs in the Group B had a significantly higher level of the colony-forming unit capability than the hMSCs cultured in the Group A(Plt;0.01). After the induction, hMSCs in the Group B had a decreasednumber of the osteoblasts than hMSCs in the Group C. The hMSCs in the Group D had a gradually-increasedactivity of ALP, which was significantly lower than that in the Group C(Plt;0.01). The RT-PCR examination revealed that ALP,osteocalcin, and mRNA expressions of collagen type Ⅰ and osteonectin in the Group Csignificantly increased （P＜0.01). By comparisonamong the 3 groups, after the 4-week culture the obvious calcium salt deposit and the red-stained calcium nodus could be observed.ConclusionHypoxia can promote the proliferation rate of hMSCs, enhance the colonyforming ability and inhibit the differentiation of the osteoblasts.
ObjectiveTo research the effect of recombinant adenovirus-bone morphogenetic protein 12 (Ad-BMP-12) transfection on the differentiation of peripheral blood mesenchymal stem cells (MSCs) into tendon/ligament cells.
MethodsPeripheral blood MSCs were isolated from New Zealand rabbits (3-4 months old) and cultured in vitro until passage 3. The recombinant adenoviral vector system was prepared using AdEasy system, then transfected into MSCs at passage 3 (transfected group); untransfected MSCs served as control (untransfected group). The morphological characteristics and growth of transfected cells were observed under inverted phase contrast microscope. The transfection efficiency and green fluorescent protein (GFP) expression were detected by flow cytometry (FCM) and fluorescence microscopy. After cultured for 14 days in vitro, the expressions of tendon/ligament-specific markers were determined by immunohistochemistry and real-time fluorescent quantitative PCR.
ResultsGFP expression could be observed in peripheral blood MSCs at 8 hours after transfection. At 24 hours after transfection, the cells had clear morphology and grew slowly under inverted phase contrast microscope and almost all expressed GFP at the same field under fluorescence microscopy. FCM analysis showed that the transfection efficiency of the transfected group was 99.57%, while it was 2.46% in the untransfected group. The immunohistochemistry showed that the expression of collagen type Ι gradually increased with culture time in vitro. Real-time fluorescent quantitative PCR results showed that the mRNA expressions of the tendon/ligament-specific genes (Tenomodulin, Tenascin-C, and Decorin) in the transfected group were significantly higher than those in untransfected group (0.061±0.013 vs. 0.004±0.002, t=-7.700, P=0.031; 0.029±0.008 vs. 0.003±0.001, t=-5.741, P=0.020; 0.679±0.067 vs. 0.142±0.024, t=-12.998, P=0.000).
ConclusionAd-BMP-12 can significantly promote differentiation of peripheral blood MSCs into tendon/ligament fibroblasts and enhance the expressions of tendon/ligament-specific phenotypic differentiation, which would provide the evidence for peripheral blood MSCs applied for tendon/ligament regeneration.
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.
Objective To investigate the effect of Kartogenin (KGN) combined with adipose-derived stem cells (ADSCs) on tendon-bone healing after anterior cruciate ligament (ACL) reconstruction in rabbits. Methods After the primary ADSCs were cultured by passaging, the 3rd generation cells were cultured with 10 μmol/L KGN solution for 72 hours. The supernatant of KGN-ADSCs was harvested and mixed with fibrin glue at a ratio of 1∶1; the 3rd generation ADSCs were mixed with fibrin glue as a control. Eighty adult New Zealand white rabbits were taken and randomly divided into 4 groups: saline group (group A), ADSCs group (group B), KGN-ADSCs group (group C), and sham-operated group (group D). After the ACL reconstruction model was prepared in groups A-C, the saline, the mixture of ADSCs and fibrin glue, and the mixture of supernatant of KGN-ADSCs and fibrin glue were injected into the tendon-bone interface and tendon gap, respectively. ACL was only exposed without other treatment in group D. The general conditions of the animals were observed after operation. At 6 and 12 weeks, the tendon-bone interface tissues and ACL specimens were taken and the tendon-bone healing was observed by HE staining, c-Jun N-terminal kinase (JNK) immunohistochemical staining, and TUNEL apoptosis assay. The fibroblasts were counted, and the positive expression rate of JNK protein and apoptosis index (AI) were measured. At the same time point, the tensile strength test was performed to measure the maximum load and the maximum tensile distance to observe the biomechanical properties. Results Twenty-eight rabbits were excluded from the study due to incision infection or death, and finally 12, 12, 12, and 16 rabbits in groups A-D were included in the study, respectively. After operation, the tendon-bone interface of groups A and B healed poorly, while group C healed well. At 6 and 12 weeks, the number of fibroblasts and positive expression rate of JNK protein in group C were significantly higher than those of groups A, B, and D (P<0.05). Compared with 6 weeks, the number of fibroblasts gradually decreased and the positive expression rate of JNK protein and AI decreased in group C at 12 weeks after operation, with significant differences (P<0.05). Biomechanical tests showed that the maximum loads at 6 and 12 weeks after operation in group C were higher than in groups A and B, but lower than those in group D, while the maximum tensile distance results were opposite, but the differences between groups were significant (P<0.05). Conclusion After ACL reconstruction, local injection of a mixture of KGN-ADSCs and fibrin glue can promote the tendon-bone healing and enhance the mechanical strength and tensile resistance of the tendon-bone interface.
