Objective To investigate the effects of the recombinanthuman bone morphogenetic protein 2 (rhBMP-2) and/or the osteogenic agents on proliferation and expression of the osteoblast phenotype differentiation of the SD rat mesenchymal stem cells（MSCs）. Methods The rat MSCs were cultured in vitro and were randomly divided into the experimental groups(Groups A-I) and the control group. In the experimental group, MSCs were induced by rhBMP2 in different doses (10, 50, 100 and 200 μg/L) in Groups BE, the osteogenic agent alone (Group A) and by the combined use of rhBMP-2 ［in different doses (10,50, 100 and 200 μg/L)］ and the osteogenic agent in Groups F-I. The MTT colorimetric assay was used to evaluate the proliferation, and the activities of alkaline phosphatase (ALP) and osteocalcin (OC) were observed at 3, 6, 9, 12 days, respectively. Results The inverted phase contrast microscopy showed that MSCs by primary culture for 12 hours were adhibited, with a fusiform shape at 48 hours. At 4 days they were polygonal or atractoid, and were spread gyrately or radiately at 6 days. At 10 days, they were spread at the bottom of the bottle.The statistical analysis showed that the expression of the osteoblast phenotype differentiation of MSCs could be induced in the experimental groups. The proliferation of MSCs could be enhanced in a dosedependent manner in GroupsB-E. The expression of the osteoblast phenotype differentiation, which was tested by the activities of ALP and OC, was significantly higher in Groups F-I than in Groups A-E. Conclusion The combined use of rhBMP-2 and the osteogenic agents can enhance the MSC proliferation and induce an expressionand maintenance of the osteoblast phenotype differentiation of the rat MSCs.
ObjectiveTo investigate the effect of Notch signaling pathway important target Hey1 expression on the differentiation and proliferation of C3H10T1/2 cells induced by bone morphogenetic protein 9 (BMP-9). MethodsHey1 lentivirus and Hey1 short hairpin RNA lentivirus were constructed and used to infect C3H10T1/2 cells to change the expression level of Hey1 in C3H10T1/2 cells. C3H10T1/2 cells infected with LV-Blank (empty plasmid) as control. The Hey1 expression levels of different groups were detected by fluorescence microscope, real-time fluorescence quantitative PCR, and Western blot. The C3H10T1/2 cells with different Hey1 expression level were induced by BMP-9 conditioned medium (BMP-9+C3H10T1/2 group, BMP-9+C3H10T1/2-Hey1 group, and BMP-9+C3H10T1/2-shHey1 group); the cells of control groups (C3H10T1/2 group and C3H10T1/2-Blank group) were cultured with normal medium. The mRNA and protein expression levels of osteogenesis related transcription factors (Runx2, osteopontin, and osteocalcin) were detected at 48 hours by real-time fluorescence quantitative PCR and Western blot assay. The cells proliferation and cycles were detected by MTT assay at 4, 5, 6, and 7 days and flow cytometry at 4, 5, and 10 days. The alkaline phosphatase (ALP) activity was analyzed by ELISA and observed by ALP staining at 4 and 7 days. ResultsC3H10T1/2 cell lines with different Hey1 expression levels were successfully established. In osteogenesis compared with BMP-9+C3H10T1/2 group, overexpression of Hey1 enhanced the mRNA and protein expressions of transcription factors (Runx2, osteopontin, and osteocalcin), and the expression of osteogenic differentiation marker (ALP) (P < 0.05); however, inhibition of Hey1 expression significantly decreased the above indexes (P < 0.05). In cell proliferation activity compared with BMP-9+C3H10T1/2 group, overexpression of Hey1 increased absorbance (A) value in MTT assay and pecentage of G2+S cells in cytometry assay, but inhibition of Hey1 expression significantly decreased the indexes (P < 0.05). ConclusionExpression of Hey1 is the important link in the osteogenic differentiation process of C3H10T1/2 cells induced by BMP-9, and plays an important role in the regulation of early cell proliferation.
Objective To study the culture and purification of the fetal mouse liver mesenchymal stem cells(MSCs) in vitro and to investigate their differentiation potential and the composite ability with true bone ceramic(TBC). Methods The single cell suspension of MSCs was primarily cultured and passaged, which was prepared from the fetal mouse liver; the flow cytometry was applied to detectCD29, CD34, CD44 and CD45. The osteogenic differentiation was induced in chemical inducing system; the osteogenic induction potency was tested. The purified fetal mouse liver MSCs were compounded with TBC covered with collagen type Ⅰ in vitro and the cell attachment and proliferation to the TBC were observed. Results The primary MSCs of fetal mouse liver were easy to culture in vitro. They proliferated well and were easy to subcultured. The proliferation ability of primary and passaged MSCs was similar. Flow cytometric analysis showed the positive results for CD29, CD44 and the negative results for CD34, CD45. After 7 days of induction, the MSCs expressed collagen type I and alkaline phosphatase(ALP) highly. After 14 days of induction, the fixed quantity of ALP increased significantly. After 28 days of induction, calcium accumulation was observed by Von Kossa’s staining. Many liver MSCs attached to the surface of TBC. Conclusion The MSCs of the fetalmouse liver can be obtained, subcultured and purified easily. After culturing in chemical inducing system, the MSCs of fetal mouse liver can be successfully induced to osteoblast-like cells, attach to the surface of TBC and proliferate well.
ObjectiveTo summarize the research progress of the effects and mechanisms of Hedgehog signaling pathway in regulating bone formation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). MethodsThe related literature concerning the regulations and mechanism of Hedgehog signaling pathway in osteogenic differentiation of BMSCs and bone formation in vivo, in vitro, and ex vivo studies in recent years was analyzed and summarized. ResultsThe in vitro studies indicate that Hedgehog signaling pathway can promote osteogenic differentiation of BMSCs via activation of key molecules Smoothened (Smo) and Gli1 which are downstream of Hedgehog signaling, and Hedgehog signaling can activate mTORC2-Akt signaling by upregulation of insulin-like growth factor which has similar effects. Hedgehog signaling regulates osteoblast differentiation via activation of Hh-Smo-Ptch1-Gli signaling pathway and inhibition of Hh-Gαi-RhoA stress fibre signaling. Hedgehog signaling can regulate key molecules of osteogenesis Runx2 for promoting osteogenic differentiation and matrix mineralization by synergism of bone morphogenetic protein and Wnt signaling, and promotes bone formation and repair and healing for bone defect and bone graft model in vivo. ConclusionHedgehog signaling can regulate bone formation and osteogenic differentiation of BMSCs via activation of Hedgehog signaling and other signaling pathways. Hedgehog signaling pathway may be a potential target for developing treatment for bone related diseases of osteoporosis and fracture healing disorders.
ObjectiveTo investigate the effect of KLD-12 polypeptide complexed with recombinant human bone morphogenetic protein 2 (rhBMP-2) on osteogenic activity of rabbit bone marrow mesechymal stem cells (BMSCs). MethodsBone marrow was harvested from 3-month-old New Zealand white rabbit, and density gradient method was used to isolate and culture BMSCs. The third generation BMSCs were used for three-dimensional culture of KLD-12 polypetide/rhBMP-2 in vitro (experimental group) and KLD-12 polypeptide (control group). The morphology of the cells in the gel was observed by inverted phase contrast microscope at 7 days; alkaline phosphatase (ALP) and osteocalcin protein content were dectected at 3, 7, 10, 14, and 21 days; collagen type I immunofluorescence staining was done and real-time fluorescent quantitative PCR was performed to detect the relative expression of collagen type I and osteocalcin gene at 14 days. ResultsUnder the inverted phase contrast microscope, the BMSCs in the gel of the experimental group and the control group showed circular growth, and the distribution was uniform at 7 days. There was no significant difference in the expressions of ALP and osteocalcin protein content between 2 groups at 3 and 7 days (P > 0.05); the above indexes in experimental group were significantly higher than those in the control group at 10-21 days (P < 0.05). Laser scanning confocal microscope observation showed that immunofluorescence staining for collagen type I was positive in the experimental group, and the expression was higher than that in the control group at 14 days. Real-time fluorescence quantitative PCR detection showed that the collagen type I and osteocalcin gene expressions were significantly higher than those in the control group (t=15.902, P=0.000; t=12.998, P=0.000). ConclusionBMSCs can normally grow and proliferate in the KLD-12 polypeptide, and KLD-12 polypeptide/rhBMP-2 has good biological activity to induce BMSCs differentiation into osteoblasts.
ObjectiveTo investigate the effect of cyclic stretch stress on the osteogenic differentiation of human cartilage endplate-derived stem cells (CESCs). MethodsCESCs were isolated from the endplate cartilage tissues by the method of agarose suspension culture system. The endplate cartilage tissue was harvested for immunohistochemical staining. Flexercell-4000TM Tension Plus system was used to apply cyclic stretch on CESCs at a frequency of 1 Hz and at a stretch rate of 10% for 1, 6, 12, or 24 hours (experimental group). No stretch stress was performed on CESCs in the same culture condition (control group). After mechanical loading, the protein expression of bone morphogenetic protein 2 (BMP-2) was measured by Western blot, and gene expressions of runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), and SOX9 were detected by real-time fluorescent quantitative PCR. ResultsImmunohistochemical staining showed BMP-2 protein expression in chondrocytes. The continuous cyclic stretch stress of 10% can increase the expression of BMP-2 protein in CESCs. Significant differences were observed in the expressions of BMP-2 protein (P<0.05) between 2 groups at the other time points except at 1 hour (P>0.05), in a time-dependent manner. The real-time fluorescent quantitative PCR indicated that the gene expressions of Runx2 and ALP showed an increasing tendency with time in the experimental group when compared with the control group, but there was down-regulated expression of SOX9. Significant difference was found in mRNA expressions of Runx2 and ALP at 12 and 24 hours and in mRNA expressions of SOX9 at 6, 12, and 24 hours between 2 groups (P<0.05), in a time-dependent manner. ConclusionCyclic stretch stress may induce osteogenic differentiation of CESCs by regulating the expressions of some genes related osteogenesis in CESCs.
ObjectiveTo investigate the effect of recombinant adenovirus-mediated bone morphogenetic protein 9 (BMP-9) and erythropoietin (EPO) genes co-transfection on osteogenic differentiation of adipose-derived stem cells (ADSCs) in vitro. MethodsThe inguinal adipose tissue was harvested from 4-month-old New Zealand rabbits, ADSCs were isolated with enzyme digestion and adherence method, and multipotent differentiation capacity was identified. The 3rd generation ADSCs were divided into 5 groups: normal cells (group A), empty plasmid control group (group B), BMP-9 or EPO recombinant adenovirus transfected cells (groups C and D), BMP-9 and EPO recombinant adenovirus co-transfected cells (group E). The inverted phase contrast microscope was used to observe the cell growth at 7 days; the expression of cell fluorescence was observed under a fluorescence microscope at 14 days, and viral transfection efficiency was calculated at 48 hours; Western blot was used to detect the expressions of BMP-9 and EPO proteins at 14 days. The expression of alkaline phosphatase (ALP) activity was detected at 3, 7, and 14 days after osteogenic induction, and alizarin red staining was used to detect calcium nodules formation and real-time fluorescence quantitative PCR to detect the expressions of osteopontin (OPN) and osteocalcin (OCN) at 3 weeks. ResultsAt 7 days after transfected, some cells showed oval, round, and irregular shape under the inverted phase contrast microscope in groups A and B; a few fusiform cells were observed in groups C and D; oval cells increased obviously, and there were only few round cells in group E. The fluorescence microscope observation showed that BMP-9 and EPO, BMP-9/EPO recombinant adenovirus could stably transfected ADSCs, with transfection efficiency of 80%-93%. The expressions of BMP-9 and EPO proteins significantly higher in group E than the other groups by Western blot (P < 0.05). The ALP activity significantly increased in group E when compared with that in the other groups at 3, 7, and 14 days after osteogenic induction (P < 0.05); the number of calcium nodules in group E was significantly more than that in the other groups (P < 0.05). Real-time fluorescence quantitative PCR showed that OPN and OCN genes expressions were significantly higher in group E than other groups (P < 0.05), and in groups C and D than groups A and B (P < 0.05). ConclusionRecombinant adenovirus-mediated BMP-9 and EPO genes can transfect ADSCs, which can stably express in ADSCs, BMP-9/EPO genes co-transfection can more promote the expressions of osteoblast-related genes and protein than non-transfected and single gene transfection.
ObjectiveTo review the research progress of induced osteogenesis of bone marrow mesenchymal stem cells (BMSCs) transfected by double-gene. MethodsThe recent literature concerning the comparative research of induced osteogenesis of BMSCs transfected by double-gene was extensively reviewed. The characteristics of BMSCs, the advantage and effect of synergistic inductive osteogenesis, the application prospect and problems of BMSCs transfected by double-gene were summarized. ResultsThe effect of induced osteogenesis concerning BMSCs transfected by double-gene is far superior to single gene transfection and the activity of osteoblast is also significantly increased. The research used in bone tissue engineering experiment also obtain good effect. ConclusionInduced osteogenesis of BMSCs transfected by double-gene is able to make up for the lack of a single gene transfection and has great development prospects in the orthopaedic field.
Objective To investigate early clinical manifestations of osteogenic sarcoma to help establishment of an early diagnosis of the disease.Methods A total of 92 patients with osteogenic sarcoma in the extremities were admitted to our hospital from April 1984 to October 2002. Of the 92 patients, 71 (42 males and 29 females; averaged age 17.4 years, range 666 years; illness course 1-28 weeks) had a complete record of their medical history and examination. From their first medical visits, we obtained their clinical symptoms, physical sings, diagnoses, and duration of the delayed diagnoses. The patients were pathologically confirmed as having osteogenic sarcoma in the extremities, with the lesions located in the distal femur in 38 patients, proximal tibia in 22, proximal femur in 3, proximal fibula in 3, proximal humerus in 2, distal tibia in 2, and distalradius in 1. Results Of the 71 patients, 70 had a local pain and/or a palpable mass, 37 had a persistent pain with no difference between day and night, 23 had an intermittent pain, and 11 had a nocturnal pain. Of the 71 patients, 42 had an initial pain related to trauma, and 3 of the 42 patients had a pathologic fracture. The patients with the local mass had a delayed diagnosis of osteogenic sarcoma with a delayed duration of 1-14 weeks, averaged 4 weeks; however, the patients without the local mass had a delayed diagnosis of this disease, with a delayed duration of 3-30 weeks averaged 14 weeks. In the patients undergoing an X-ray examination at the first medical visit, the duration of the delayed diagnoses was 1-20 weeks, averaged 8 weeks, but in the patients without an X-ray examination at first, the duration was 4-30 weeks, averaged 16 weeks. Conclusion Intermittent and persistent pains and local masses are the most characteristic clinical manifestations in the early stage of osteogenic sarcoma. A history of trauma often helps to make a diagnosis of the disease. Carefulclinical examination and observation should be given to adolescent patients whohave a recurrent pain around the joint.
To review the advance in the experimental studies and evaluate the potential therapeutic appl ication of the growth differentiation factor 5(GDF-5) and osteogenic protein 1 (OP-1) in intervertebral disc degeneration.Methods Relevant l iterature at home and abroad publ ished in recent years was searched and analyzedcomprehensively. Results The growth factor was one of the most potential proteins in curing the intervertebral discdegeneration. In vitro, exogenous GDF-5 or OP-1 increased the deoxyribonucleic acid and proteoglycan contents ofboth nucleus pulposus and annlus fibrosis cells types significantly. GDF-5 at 200 ng/mL or OP-1 significantly stimulatedproteoglycan synthesis and collagen synthesis. In vivo, the injection of GDF-5(100 μg) or OP-1(100 μg in 10 μL 5% lactose) resulted in a restoration of disc height, improvement of magnetic resonance imaging scores, and histologic grading scores had statistical significance. Conclusion A single injection of GDF-5 or OP-1 has a reparative capacity on intervertebral discs, presumably based on its effect to stimulate matrix metabol ism of intervertebral disc cells and enhance extracellular matrix production. A single injection of exogenous GDF-5 or OP-1 in the degenerated disc shows a good prospect.