Objective To study the effects of hypoxic preconditioning on the glucose metabol ism of rat BMSCs and its underlying mechanism so as to provide the theoretical basis for the optimization of the stem-cell based therapy. Methods Density gradient centrifugation method was adopted to isolate rat BMSCs from neonatal SD rats (aged 1-3 days). BMSCs were cultured to 4th passage and divided into 4 groups based on different culture conditions: group A in normoxia condition for 24 hours, group B in 1% O2 for 24 hours, group C in 2-methoxyestradiol (20 μmol/L) for 24 hours before hypoxic preconditioning, and group D in hypoxia-inducible factor 1 (HIF-1) specific siRNA (50 μmol/L) for 12 hours before hypoxicpreconditioning. MTT method was appl ied to evaluate the prol iferation of BMSCs. Biochemical analyzer and Real-timefluorescent quantitative PCR were appl ied to detect the glucose uptake, lactate production, and HIF-1α mRNA and Glut-1mRNA levels of BMSCs. Results MTT showed that the absorbance (A) values were 387.67 ± 58.92, 322.50 ± 50.60, 297.00 ± 53.00, and 286.00 ± 41.00 in groups A, B, C, and D, respectively, showing no significant difference among 4 groups (P gt; 0.05). The levels of glucose uptake and lactate production were higher in group B than in groups A, C, and D, showing significant differences (P lt; 0.05); the levels of groups C and D were higher than those of group A, but showing no significant difference (P gt; 0.05). The mRNA expressions of HIF-1α and Glut-1 elevated significantly in group B when compared with those in group A (P lt; 0.05); groups C and D were significantly lower than group B (P lt; 0.05) and were significantly higher than group A (P lt; 0.05). Conclusion Hypoxic preconditioning can stimulate the glucose uptake and metabol ism of rat BMSCs, whose mechanism is probably related to up-regulating the mRNA expressions of HIF-1α and Glut-1.
Objective To investigate the effects of NGF on the prol iferation, mitotic cycle, collagen synthesis and migration of human dermal fibroblasts (HDFs), and to explore the function of NGF on the wound heal ing. Methods The 3rd generation of HDFs were incubated with various concentrations of NGF (0, 25, 50, 100, 200 and 400 ng/mL), the cell prol iferation was measured with MTT assay. After treated with NGF at 0, 100 ng/mL, the cell cycle of HDFs was determined by flow cytometry (FCM). Hydroxyprol ine and real-time fluorescence quantitative PCR (FQ-PCR) were used to measure collagen synthesis at protein level and mRNA level respectively. The in vitro cell scratch wound model was set up to observe the effect of NGF (0, 50, 100 and 200 ng/mL) on the migration of HDFs after 24 hours of culture. Results Absorbance value of HDFs for different concentrations of NGF (0, 25, 50, 100, 200, and 400 ng/ mL) showed that NGF did not influence the prol iferation of HDFs (P gt; 0.05). When HDFs were treated with NGF at 0 and 100 ng/mL, the result of FCM analysis showed that percentage of HDFs in G0/G1, S, G2/M phases were not changed (P gt; 0.05). Compared with control group, the expression of Col I and Col III were not significantly different, measured by both hydroxyprol ine and FQ-PCR (P gt; 0.05). The rates of HDFs’ migration at various concentrations of NGF (0, 50, 100, 200 ng/ mL) were 52.12% ± 6.50%, 80.67% ± 8.51%, 66.33% ± 3.58%, and 61.19% ± 0.97%, respectively, indicating that NGF could significantly enhanced the migration of HDFs at 50 and 100 ng/mL (P lt; 0.05). Conclusion NGF does not influence prol iferation, mitotic cycle and collagen synthesis of HDFs, but significantly enhanced migration in an in vitro model of wounded fibroblasts.
【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
Objective To study the possibil ity of bone marrow mesenchymal stem cells (BMSCs) differentiation into tenocytes (TCs) under strain stimulation by co-culture of BMSCs-small intestinal submucosa (SIS) composites in vitro. Methods BMSCs were isolated by adherent culture from the bone marrow of 1-week-old SD rats. Inducing method of multiple differentiation and flow cytometry were appl ied to identify the cells. The stress-strain curve of SIS was measured with Instron machine. Purified BMSCs (2nd passage, 2.5 × 105 cells/cm2) were seeded on SIS (3 cm × 1 cm at size) and cultured for 2 daysand then continued for another 5 days under strain stimulation (stretching frequency was 0.02 Hz, action time was 15 minutes/ hour and 12 hours/day, strain ampl itude was 5%) as experimental group, while the BMSCs-SIS composites were sustained static culture as control group. TCs were isolated from tail of 1-week-old SD rats. TCs-SIS composites were cultured under non-strained as positive control group. Scanning electron microscope (SEM) was used to examine the morphological changes of BMSCs after strain stimulation. The contents of Scleraxis and Tenomodulin in supernatant were tested by ELISA kit. Results The BMSCs could be induced to differentiate into osteoblasts and l ipocytes, and showed the results of CD34-, CD45-, and CD90+, which were accorded with the biological characteristics of BMSCs. The failure test of SIS showed that the average elastic strain was 39.5%. SEM observation showed that the strain-stimulated BMSCs had the TCs-l ike morphological characteristics. The contents of Scleraxis and Tenomodul in in supernatant of experimental group, control group, and positive control group were (3.56 ± 0.91) μmol/L and (4.27 ± 1.10) μmol/L, (0.23 ± 0.14) μmol/L and (0.16 ± 0.10) μmol/L, and (14.73 ± 2.30) μmol/L and (10.65 ± 1.51) μmol/L, respectively. There were significant differences among 3 groups (P lt; 0.05). Conclusion Appropriate strain stimulation could induce BMSCsdifferentiate into TCs, and the best conditions of strain stimulation need more experiments.
Objective To study the biological characteristic of rabbit bone marrow mesenchymal stem cells (BMSCs) double-labeled by PKH26 and BrdU in vitro, and to construct tissue engineered cardiac patch in vitro. Methods The BMSCs were harvested from 6-month-old New Zealand rabbits and labeled with PKH26 and BrdU. The growth and fluorescent intensitywere observed by inverted phase contrast microscope, fluorescent microscope, flow cytometry, and MTT detection. Thecharacteristics of double-labeled BMSCs differentiating into osteoblasts and adipocytes, respectively, in vitro were identified by alkal ine phosphatase (ALP) staining, Al izarin red staining, Oil red O staining, immunocytochemical technique of collagen type I, and osteocalcin expression. The labeled BMSCs were seeded on the small intestinal submucosa (SIS) and co-cultured for 5-7 days to construct tissue engineered cardiac patch. The patches were tested by inverted phase contrast microscope, fluorescent microscope, scanning electron microscope, and HE staining to observe the cell prol iferation. Results The double-labeled cells grew well and showed red fluorescence. There was no significant difference in the growth characteristic between the labeled and unlabeled cells. There was no significant difference in the expression of stem cell specific surface antigen between before lebel ing and after lebel ing. After osteogenic induction of labeled BMSCs, ALP staining and Al izarin red staining were positive, and the cells expressed collagen type I and osteocalcin. After adipocytes induction, l ipid droplets could be observed in cytoplasm by Oil red O staining. After the co-culture in vitro for 5-7 days, the double-labeled cells grew well, showing a multi-layer cellular structure on the surface of SIS. Conclusion Rabbit BMSCs can be double-labeled with PKH26 and BrdU stably. The labeled cells still have the potential of self-renewal abil ity and multipotent differentiation abil ity; tissue engineered cardiac patch can be constructed by co-culturing labeled BMSCs and SIS in vitro.
Objective To study the effect of hypoxia on the prol iferation of hBMSCs and human placental decidua basal is-MSCs (hPDB-MSCs), and to provide the theoretical basis for discovering the new seed cells source for tissue engineering. Methods Density gradient centrifugation method was adopted to isolate and culture hBMSCs and hPDB-MSCs,flow cytometry (FCM) was appl ied to detect cell surface marker. After establ ishing the experimental model of CoC12 chemical hypoxia, MTT method was appl ied to evaluate the prol iferation of hBMSCs and hPDB-MSCs at different time points (6, 12, 24, 48, 72, 96 hours) with various CoC12 concentration (0, 50, 75, 100, 125, 150, 175, 200 μmol/L). Results FCM analysis revealed that hPDB-MSCs and hBMSCs expressed CD9, CD29, CD44, CD105, CD106 and human leucocyte antigen ABC (HLA-ABC), but both were absent for CD34, CD40L and HLA-DR. Compared with hBMSCs, hPDB-MSCs expressed stage-specific embryonic antigen 1 (SSEA-1), SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81 better. The prol iferations of hPDB-MSCs and hBMSCs were inhibited within the first 12 hours under hypoxia condition, but promoted after 12 hours of hypoxia. Compared with the control group, the hBMSCs were remarkably prol iferated 24 hours after hypoxia with CoC12 concentration of 150 µmol/L (P lt; 0.05), while hPDB-MSCs were significantly prol iferated 12 hours after hypoxia with CoC12 concentration of 75 µmol/L (P lt; 0.05). Conclusion Compared with hBMSCs, hPDB-MSCs express more specific surface antigens of embryonic stem cells and are more sensitive to the prol iferation effects of chemical hypoxia, indicating it may be a new seed cells source for tissue engineering.
Objective To study the effect of rat osteoblast conditioned culture medium on the BMSCs differentiation of allogeneic rat and to find a new approach to provide seed cells for bone tissue engineering. Methods BMSCs and osteoblasts were harvested from 10 healthy one-week-old SD rats (male and female, weighing 20-30 g) by adherent method and enzyme digestion method respectively. Cell identification was conducted. Osteoblast conditioned culture medium was prepared by mixing supernatant of osteoblasts at passage 1-5 with complete medium (1:1). Then, BMSCs at passage 2 were co-cultured with osteoblast conditioned culture medium (inducement group) and complete medium (control group), respectively. The morphological changes of co-cultured BMSCs were observed by inverted phase contrast microscope, the growth condition of BMSCs was detected by MTT method, the expressions of ALP, Col I and osteocalcin (OCN) in the cocultured BMSCs were tested by immunohistochemistry staining, and the expressions of Col I and OCN mRNA were detected by RT-PCR. Results In the inducement group, BMSCs grew bigger, changing from long fusiform to flat and polygon with protuberance 7 days after co-culture; the presence of cell colony-l ike growth was observed 9 days after co-culture. Cell growth curve demonstrated that the counts of BMSCs was increased with time, there were more cells in the control group than that of the inducement group, and there was a significant difference in cell counts between the control and the inducement group 4-7 days after co-culture (P lt; 0.05). For the inducement group, ALP staining was positive 12 days after co-culture, the calcium nodules were appeared 18 days after co-culture, Col I and OCN were positive 21 days after co-culture, and the expressions of Col I and OCN mRNA were detected by RT-PCR 21 days after co-culture. Conclusion Rat osteoblast conditioned culture medium can significantly induce the differentiation of allogeneic rats’ BMSCs towards osteoblasts.
Objective To evaluate the effect of copper-ion on the prol iferation and differentiation of human umbil ical vein endothel ial cell (HUVEC). Methods HUVEC were cultured and passaged in vitro. HUVEC were inoculated into 96-well plate with density of 5 × 103/well. All the cells were divided into 3 groups randomly according to different culture mediums: group A (5 μmol/L CuSO4), group B (25 μmol/L CuSO4), group C (control group). Every group had 4 wells, and the basic culture medium was MCDB131. The cell growth curves of 3 groups were drawn by using MTT. HUVEC were inoculated into 6-well plate with density of 2 × 105/well. Grouping of the cells was the same as the above. The gene expressions of endothel ial nitric oxide synthase (eNOS) and tyrosine kinase with immunoglobul in-l ike and EGF-l ike domain 1 (Tie-1) were detected by real-time RT-PCR. Results The growth curves revealed that the exponential growth time was the first 3 days, plateau growth time begun on the 4th day. The prol iferation of group A was ber than that of groups B and C from the 3rd day, within 2 days, the prol iferation of group B was ber than that of group C; however, it decreased and was weaker than group C from the 4th day, all showing statistically significant difference (P lt; 0.05). The results of real-time RT-PCR revealed that the expressions of eNOS in groups A, B and C were 7.294 ± 1.488, 0.149 ± 0.044 and 1.000 ± 0.253; and the expressions of Tie-1 in groups A, B and C were 1.481 ± 0.137, 1.131 ± 0.191 and 1.000 ± 0.177. Group A compared with groups B and C, both of 2 genes were up-regulated (P lt; 0.05). Group B compared with group C, eNOS was down-regulated (P lt; 0.05) and the difference of Tie-1 expression was not statistically significant (P gt; 0.05). Conclusion 5 μmol/L copper-ion can promote the prol iferation and differentiation of HUVEC effectively.
Objective To compare the molecular phenotype of human intervertebral disc cells and articular chondrocytes and to analyze whether hBMSCs can differentiate into both chondrocytes and nucleus pulposus cells after combined induction of TGF-β3 and BMP-7 in vitro. Methods The cells with the characteristics of hBMSCs were isolated from marrow aspirates of the volunteer donors’ il iac crest. Human bone marrow was removed and fractionated, and adherent cell cultures were establ ished. The 4th passage cells were then translated into an aggregate culture system in a serum-free medium. The pellet cultures of hBMSCs were divided into four groups: 10 ng/mL TGF-β3 group (group A), 200 ng/mL BMP-7 group (group B), combination group of TGF-β3 and BMP-7 (group C) and blank group as the control (group D). Histological observation, RT-PCR and RQ-PCR were appl ied to measure the expressions of collagen type I, II, X, aggrecan and SOX9 on the 4th and 21st day after cell induction, respectively. Results As was shown by histological observation, the induced cells expressed the feature of chondrocytes in morphology and ECM in groups A and C on the 21st day after the culture. And the collagen type II was positive after staining in groups A and C. The cell morphology of the induced cells in groups B and C had no obviouly changed. PCR detection showed that the expressions of SOX9, aggrecan, collagen type I, II in groups A and C at 21st day were more increased than those at 4th day (P lt; 0.05). The only expressions of collagen type I in groups B and D at 21st day were more increased than those at 4th day (P lt; 0.05). The expressions of collagen type X only was positive in group A. Conclusion Combination of TGF-β3 and BMP-7 can make the differentiated cells from hBMSCs much closer to intervertebral disc cells, so it perhaps could provide seed cells for intervertebral disc tissue engineering.
Objective Extracellular matrix is one of the focus researches of the adi pose tissue engineering. To investigate the appropriate method to prepare the porcine skeletal muscle acellular matrix and to evaluate the biocompatibility of the matrix. Methods The fresh skeletal muscle tissues were harvested from healthy adult porcine and were sl iced into2-3 mm thick sheets, which were treated by hypotonic-detergent method to remove the cells from the tissue. The matrix was then examined by histology, immunohistochemistry, and scanning electron microscopy. The toxic effects of the matrix were tested by MTT. Human adi pose-derived stem cells (hADSCs) were isolated from adi pose tissue donated by patients with breast cancer, and identified by morphology, flow cytometry, and differentiation abil ity. Then, hADSCs of passage 3 were seeded into the skeletal muscle acellular matrix, and cultured in the medium. The cellular behavior was assessed by calcein-AM (CA) and propidium iodide (PI) staining at 1st, 3rd, 5th, and 7th days after culturing. Results Histology, immunohistochemistry, and scanning electron microscopy showed that the muscle fibers were removed completely with the basement membrane structure; a large number of collagenous matrix presented as regular network, porous-like structure. The cytotoxicity score of the matrix was grade 1, which meant that the matrix had good cytocompatibil ity. The CA and PI staining showed the seeded hADSCs had the potential of spread and prol iferation on the matrix. Conclusion Porcine skeletal muscle acellular matrix has good biocompatibility and a potential to be used as an ideal biomaterial scaffold for adi pose tissue engineering.