Objective To investigate the effects of the misshapen auricular chondrocytes from microtia in inducing chondrogenesis of human adipose derived stem cells (ADSCs) in vitro. Methods Human ADSCs at passage 3 and misshapen auricular chondrocytes at passage 2 were harvested and mixed at a ratio of 7 ∶ 3 as experimental group (group A, 1.0 × 106 mixed cells). Misshapen auricular chondrocytes or ADSCs at the same cell number served as control groups (groups B and C, respectively). All samples were incubated in the centrifuge tubes. At 28 days after incubation, the morphological examination was done and the wet weight was measured; the content of glycosaminoglycan (GAG) was detected by Alcian blue colorimetry; the expressions of collagen type II and Aggrecan were determined with RT-PCR; and HE staining, toluidine blue staining, Safranin O staining of GAG, and collagen type II immunohistochemical staining were used for histological and immunohistochemical observations. Results At 28 days after incubation, all specimens formed disc tissue that was translucent and white with smooth surface and good elasticity in groups A and B; the specimens shrank into yellow spherical tissue without elasticity in group C. The wet weight and GAG content of specimens in groups A and B were significantly higher than those in group C (P lt; 0.05), but no significant difference was found between groups A and B in the wet weight (t=1.820 3, P=0.068 7) and in GAG content (t=1.861 4, P=0.062 7). In groups A and B, obvious expressions of collagen type II and Aggrecan mRNA could be detected by RT-PCR, but no obvious expressions were observed in group C; the expressions in groups A and B were significantly higher than those in group C (P lt; 0.05), but no significant difference was found between groups A and B in collagen type II mRNA expression (t=1.457 6, P=0.144 9) and Aggrecan mRNA expression (t=1.519 5, P=0.128 6). Mature cartilage lacunas and different degrees of dyeing for the extracellular matrix could be observed in groups A and B; no mature cartilage lacunas or collagen type II could be observed in group C. The expression of collagen type II around cartilage lacuna was observed in groups A and B, but no expression in group C; the gray values of groups A and B were significantly lower than that of group C (P lt; 0.01), but no significant difference was found between groups A and B (t=1.661 5, P=0.09 7 0). Conclusion Misshapen auricular chondrocytes from microtia can induce chondrogenic differentiation of human ADSCs in vitro.
Objective To evaluate the synergistic effect of bone morphogenetic protein 14 (BMP-14) and chondrocytes co-culture on chondrogenesis of adipose-derived stem cells (ADSCs) so as to optimize the source of seed cells for cartilage tissue engineering. Methods ADSCs and chondrocytes were isolated and cultured respectively from articular cartilage and subcutaneous fat of 2 male New Zealand white rabbits (weighing, 1.5 kg and 2.0 kg). The cells at passage 3 were harvested for experiment. ADSCs were identified by osteogenic induction (alizarin red staining), chondrogenic induction (alcian blue staining), and adipogenic induction (oil red O staining). The optimum multiplicity of infection (MOI) of transfection of adenovirus-cytomegalovirus (CMV)-BMP-14-internal ribosome entry site (IRES)-human renilla reniformis green fluorescent protein 1 (hrGFP-1) was determined and then ADSCs were transfected by the optimum MOI. The experiment was divided into 5 groups: group A, co-culture of ADSCs transfected by BMP-14 and chondrocytes (1 ∶ 1 in Transwell chambers); group B, co-culture of ADSCs and chondrocytes (1 ∶ 1 in Transwell chambers); group C, culture of ADSCs transfected by BMP-14; group D, simple chondrocytes culture; and group E, simple ADSCs culture. After 3 weeks, the glycosaminoglycan (GAG) content was detected by alcian blue staining; the expressions of collagen type II and BMP-14 protein were detected by Western blot; expression of Sox-9 gene was detected by RT-PCR. Results The cultured cells were proved to be ADSCs by identification. Inverted fluorescence microscope showed optimum transfection effect when MOI was 150. GAG content, expressions of collagen type II and BMP-14 protein, expression of Sox-9 gene were significantly higher in groups A and C than in the other 3 groups, in group A than in group C (P lt; 0.05), and groups B and D were significantly higher than group E (P lt; 0.05), but no significant difference was found between groups B and D (P gt; 0.05). Conclusion It can promote differentiation of ADSCs into chondrocytes by BMP-14 co-culture with chondrocytes, and they have a synergistic effect.
Objective To observe the chondrogenic differentiation of adipose-derived stem cells (ADSCs) by co-culturing chondrocytes and ADSCs. Methods ADSCs and chondrocytes were isolated and cultured from 8 healthy 4-month-old New Zealand rabbits (male or female, weighing 2.2-2.7 kg). ADSCs and chondrocytes at passage 2 were used. The 1 mL chondrocytes at concentration 2 × 104/mL and 1 mL ADSCs at concentration 2 × 104/mL were seeded on the upper layer and lower layer of Transwell 6-well plates separately in the experimental group, while ADSCs were cultured alone in the control group. The morphology changes of the induced ADSCs were observed by inverted phase contrast microscope. The glycosaminoglycan and collagen type II synthesized by the induced ADSCs were detected with toluidine blue staining and immunohistochemistry staining. The mRNA expressions of collagen type II, aggrecan, and SOX9 were detected with real-time fluorescent quantitative PCR. Results ADSCs in the experimental group gradually became chondrocytes-like in morphology and manifested as round; while ADSCs in the control group manifested as long spindle in morphology with whirlool growth pattern. At 14 days after co-culturing, the results of toluidine blue staining and immunohistochemistry staining were positive in the experimental group, while the results were negative in the control group. The results of real-time fluorescent quantitative PCR indicated that the expression levels of collagen type II, aggrecan, and SOX9 mRNA in the experimental group (1.43 ± 0.07, 2.13 ± 0.08, and 1.08 ± 0.08) were significantly higher than those in the control group (0.04 ± 0.03, 0.13 ± 0.04, and 0.10 ± 0.02) (P lt; 0.05). Conclusion ADSCs can differentiate into chondrocytes-like after co-culturing with chondrocytes.
Objective Bone marrow mesenchymal stem cells (BMSCs) transplantation can potentially regenerate the degenerated intervertebral disc, with the underlying regenerating mechanism remaining largely unknown. To investigate the potential of human BMSCs protecting nucleus pulposus cells (NPCs) from oxidative stress-induced apoptosis in a coculturesystem, and to illustrate the possible mechanisms of BMSCs transplantation for intervertebral disc regeneration. Methods BMSCs collected by density gradient centrifugation in Percoll solution were cultured and sub-cultured till passage 3, and the surface molecules of CD34, CD45, and CD13 were identified. NPCs were isolated by collagenase digestion and the chondrocyte l ike phenotype was confirmed by morphologic observation after HE staining, inverted phase contrast microscope, proteoglycan, and collagen type II expression after toluidine blue and immunocytochemistry staining. The 3rd passage BMSCs and the 1st passage NPCs were divided into four groups: group A, NPCs (1 × 106 cells) were cultured alone without apoptosis inducing (negative control); group B, NPCs (1 × 106 cells) were co-cultured with BMSCs (1 × 106 cells) with apoptosis inducing; group C, NPCs (1 × 106 cells) were co-cultured with BMSCs (3 × 105 cells) with apoptosis inducing; group D, NPCs (1 × 106 cells) were cultured alone with apoptosis inducing (positive control). After 3 or 7 days of culture or co-culture, the NPCs in groups B, C, and D were exposed to 0.1 mmol hydrogen peroxide for 20 minutes to induce apoptosis. With DAPI staining cellular nucleus, Annexin-V/propidium iodide staining cellular membrane for flow cytometry analysis, the apoptosis of NPCs in each group was studied both qual itatively and quantitatively. Besides, the changes in Bax/Bcl-2 gene transcription and Caspase-3 protein content, were analyzed with semi-quantitative RT-PCR and Western blot. Results BMSCs were successfully isolated and CD34-, CD45-, and CD13+ were demonstrated; after isolated from degenerated intervertebral discs and sub-cultured, the spindle-shaped 1st passage NPCs maintained chondrocyte phenotype with the constructive expressions of proteoglycan and collagen type II in cytoplasm. DAPI staining showed the nucleus shrinkage of apoptosis NPCs. Co-cultured with BMSCs for 3 days and 7 days, the apoptosis rates of NPCs in groups B (29.26% ± 8.90% and 18.03% ± 2.25%) and C (37.10% ± 3.28% and 13.93% ± 1.25%) were lower than that in group D (54.90% ± 5.97% and 26.97% ± 3.10%), but higher than that of groupA (15.67% ± 1.74% and 8.87% ± 0.15%); all showing significant differences (P lt; 0.05). Besides, semi-quantitative RT-PCR showed Bcl-2 gene transcription up-regulated (P lt; 0.05) and no significant change of Bax (P gt; 0.05); Western blot result showed that the Caspase-3 protein expression of groups B and C was lower than that of group D, and was higher than that of group A; all showing significant differences (P lt; 0.05). Conclusion In a co-culture system without direct cellular interactions, the oxidative stress-induced apoptosis of human NPCs was amel iorated by BMSCs. The enhanced anti-apoptosis abil ity of NPCs preconditioned by co-culturing with BMSCs might come from the decreased Bax/Bcl-2 gene transcription ratio.
Objective To investigate the adhesiveness of osteoblasts and vascular endothel ial cells from rat BMSCs co-cultured on allogeneic freeze-dried partially bone in vitro. Methods The BMSCs were isolated from 4-week-old SD rats (weighing 100-110 g) and cultured in vitro. The third generation of BMSCs were induced into osteoblasts and vascular endothel ial cells. The osteoblasts and vascular endothel ial cells after being induced for 7 days in a ratio of 1 to 1 were directlyco-cultured (experimental group), while the second generation of uninduced BMSCs was used as a control (control group). The growth and prol iferation abil ity were analyzed by MTT examination and the growth curve was drawn at 1-8 days. The osteoblasts and vascular endothel ial cells after being induced for 14 days were implanted in the allogeneic freeze-dried partially bone coated by 20% Col I or not at different densities (0.25 × 106/mL、0.50 × 106/mL、1.00 × 106/mL、2.00 × 106/mL、4.00 × 106/mL), as modified group and unmodified group, the cell adherence rate was calculated after 24 hours. These two kinds of cells were implanted in the pre-disposal treated allogeneic freeze-dried partially bone and observed by scanning electron microscope. Results ALP staining of osteoblasts showed that there were blue grains in cytoplasm at 7 days. CD31 and CD34 immunocytochemical staining of vascular endothelial cell showed that there were positive signals in the cytoplasm at 14 days. The MTT test showed that the prol iferation level of the experimental group was lower than those of the control group. There were significant differences in absorbance value between two group from 3 days to 8 days (P lt; 0.05). The cell adherence rate increased with increasing seeding density when the seeding density was (0.25-1.00) × 106/mL. The cell adherence rate reached the peak when the seeding density was 1.00 × 106/mL. The cell adherence rate decreased when the seeding density was more than 2.00 × 106/mL. There were significant differences in cell adherence rate between modified group and unmodified group at different seeding densities (P lt; 0.05). The prol iferation of the osteoblasts and endothel ial cells presented better growth and histocompatibil ity under scanning electron microscope. Conclusion The growing behavior of two kinds of cells is good in the allogeneic freezedried partially bone coated by 20% Col I , which can be used in reconstrction of vascularized tissue engineered bone.
Objective To make an experimental research of the tissue engineered rat submandibular glands (SMG) cells growing on a collagensponge scaffold under an optimal culture condition. Methods The Wistar rat (8 days old) SMG cells of the second generation were seeded onthesurface of the collagen sponge scaffold (5 mm×5 mm×2 mm) and were cultured under a physiologically optimal condition for 3 weeks. At 1, 2 and 3 weeks, the cultured cells were observed on their shapes and structures by the histological examination and the scanning electron microscopy. The cultured cells underwentthe immunohistochemistry research (the cytokratin 813,CK8.13;αsmooth muscular actin,αSMA) staining performed at 3 weeks of the culture, and the amylaseactivity analysis (the Amano method) performed at 1 day, 1, 2 and 3 weeks of the culture for an evaluation on the secretion function of the cells; the ultrastructures of the cells were also observed by the transmission electron microscopy for an identification of their origins. Results The observatio n under the scanning electron microscope showed that at 1 week after the cellseeding, the seeded cells were attached to the collagen sponge scaffold surface, with no cell process formed; at 2 weeks the cells increased, with formation of the cell process that was anchored on the collagen sponge scaffold surface; and at 3 weeks, the scaffold surfaceattached cells increased, with formation of thefiliform fibers in the surface layer of the cells. The immunohistochemistry staining showed that the cultured epithelial cells of SMG were bly positive for the specific antibody of CK8.13, and the myoepithelial cells were positive forthe specific antibody of αSMA. The transmission electron microscopy showed that in the surface layer of the cultured epithelial cells of SMG the microvilli,plasm crease, and zymogen granules were observed, with a big and ovalshaped nucleus in the cell, and mitochondria and rough endoplasmic reticulum in the cytoplasm of the cell. The amount of amylase secreted by the cells cultured with thecollagen sponge scaffolds increased at a different degree with an extension of the culturing time. Conclusion The collagen sponge has a satisfactory cell compatibility, and the SMG cells cultured with this kind of collagen sponge can keep their abilities of proliferation and differentiation and theirfunction of secretion. Therefore, this kind of cultured SMG cells can be used as the tissueengineered cells seeded in the scaffold.
Objective To investigate the effects of curcumin on oxidative stress in the co-culture system including human fetal lung fibroblasts and A549 cells, and discuss the potential and protective mechanism of the prophylactic effect of curcumin on pulmonary fibrosis. Methods The human fetal lung fibroblasts co-cultured with A549 cells were divided into five groups. The cells in the control group were cultured in DMEM without TGF-β1 or curcumin. The cells in the TGF-β1 group were cultured in DMEM containing 5 ng/mL TGF-β1 . In three TGF-β1 + cucurmin treatment groups, the cells were cultured in DMEM containing 5 ng/mL TGF-β1 and three different concentration of curcumin( 5, 10, 20 μmol /L, respectively) . ELISA was used to analyze the content of TNF-α. Serum level of MDA and SOD were tested by spectrophotometric analysis. Intracellular ROS production was detected by flow cytometry. NF-κB was measured by western blot. Results The serum MDA, intracellular ROS, the content of TNF-αand NF-κB protein expression in the TGF-β1 group were significantly increased while the activity of SOD was significantly decreased( P lt; 0. 01) , suggesting that the oxidative level of human fetal lung fibroblasts was obviously increased after TGF-β1 stimulation. After intervening by different concentration of curcumin, the serum MDA, intracellular ROS, content of TNF-αand NF-κB were significantly decreased while the activity of SOD was obviously increased( P lt;0.01) . Conclusion Low concentration of curcumin can reduce the oxidative level of human fetal lung fibroblasts co-cultured with A549 after TGF-β1 stimulation, and significantly increase the level of SOD, implying that curcumin may intervene pulmonary fibrosis by reduce oxidative level.
ObjectiveTo establish the co-culture model of mice's early embryo and tumor cells in Vitro to observe the embryonic development and biologic behavior of tumor cells in the same microenvironment and discuss their interaction. MethodsWe acquired 2-cell embryos from mice, and then co-cultured them with tumor cell lines of mice in Vitro. We observed the development of embryos in Vitro and the rates of 4-cell embryos, morula and blastocyst formation. The transwell chamber was used for culture. Methylthiazolyldiphenyl-tetrazolium method was used to test the proliferative activity of tumor cells, while the flow cytometry was used to test its apoptosis. The interaction of co-cultured embryos and tumor cells was analyzed by propidium iodide staining and immunohistochemical technique. ResultsThe co-cultured 2-cell embryos could continue surviving and developing. The rates of 4-cell embryos, morula and blastocyst formation increased significantly in the co-cultured group (P<0.05). There was no significant difference in the proliferative activity and apoptosis of tumor cells between the co-cultured group and the control group (P>0.05). Tumor-free ring formed between the trophoblast and tumor cells. We could observe tumor cells stacked around the tumor-free ring. However, no difference in expression of proliferating cell nuclear antigen and B-cell lymphoma leukemia-2 was observed in tumor cells stacking around the tumor-free ring compared with those elsewhere. ConclusionThe development of 2-cell embryos is enhanced in the co-culture model. The proliferative activity and apoptosis of tumor cells are not affected in this model. A tumor-free ring can form between trophoblast and tumor cells. However, the proliferative activity of tumor cells is not affected by this ring.
ObjectiveTo review the research progress of the co-culture system for constructing vascularized tissue engineered bone. MethodsThe recent literature concerning the co-culture system for constructing vascularized tissue engineered bone was reviewed, including the selection of osteogenic and endothelial lineages, the design and surface modification of scaffolds, the models and dimensions of the co-culture system, the mechanism, the culture conditions, and their application progress. ResultsThe construction of vascularized tissue engineered bone is the prerequisite for their survival and further clinical application in vivo. Mesenchymal stem cells (owning the excellent osteogenic potential) and endothelial progenitor cells (capable of directional differentiation into endothelial cell) are considered as attractive cell types for the co-culture system to construct vascularized tissue engineered bone. The culture conditions need to be further optimized. Furthermore, how to achieve the clinical goals of minimal invasion and autologous transplantation also need to be further studied. ConclusionThe strategy of the co-culture system for constructing vascularized tissue engineered bone would have a very broad prospects for clinical application in future.
ObjectiveTo construct large block of engineered liver tissue by co-culture of fibroblasts and hepatocytes on collagen hydrogels in vitro and do in vivo implantation research. MethodsSilastic mould was prepared using three-dimensional printing technology. The collagen hydrogel scaffold was prepared by collagen hydrogel gel in the silicone mould and was removed. Sprague Dawley rat lung fibroblasts were co-cultured with primary hepatocytes at a ratio of 0.4:1 on the collagen hydrogel scaffold to construct large block of engineered liver tissue in vitro (group B), and primary hepatocytes cultured on the collagen hydrogel scaffold served as control group (group A). The cell morphology was observed, and the liver function was tested at 1, 3, 7, 14, and 21 days after culture. The rat model (n=24) of hepatic cirrhosis was made by subcutaneous injection of carbon tetrachloride. And in vivo implantation study was carried in cirrhosis rat model. The phenotypic characteristics and functional expression of hepatocytes were evaluated at 3, 7, 14, 21, and 28 days after implantation. ResultsIn vitro results indicated that hepatocytes in group B exhibited compact polyhedral cells with round nuclei and high expression of liver function. Moreover, cells aggregated to the most at 7 days. Album production and urea synthesis incresed significantly when compared with group A (P<0.05). In vivo results showed hepatocytes in group B survived for 28 days, and albumin production and urea synthesis were significantly increased. In addition, hepatocytes showed an aggregated distribution and cord-like structures, which was similar to normal liver tissue. ConclusionThe large block of engineered liver tissue constructed by co-cultured cells can form tissue similar to normal liver tissue in vivo, and survive for a long time, laying foundations for building more complete engineered liver tissue in the future.