Objective To explore the effects of calcitonin gene-related peptide (CGRP) on the migration of bone marrow mesenchymal stem cells (BMSCs) and vascular endothel ial growth factor (VEGF) expression in vitro. Methods TheBMSCs were isolated from Sprague Dawley rats using whole bone marrow adherence method. At 1, 2, and 3 weeks after culture, the expressions of CGRP receptor (CGRPR) was detected by Western blot. The BMSCs were treated with CGRP at concentration 1 × 10-8 mol/L (experimental group) and did not treated (control group), and the efficacy of BMSCs migration was analyzed by Transwell chamber assay after 72 hours; at 1, 3, 5, and 7 days, the mRNA expressions of vascular cell adhesion molecule 1 (VCAM-1) were detected by real-time fluorescent quantitative PCR; the protein expressions of VEGF were examined using immunohistochemistry and Western blot. Results CGRPR expressed stably in the cultured BMSCs and reached the peak at 2 weeks. CGRP had a significantly enhanced role in promoting cell migration. The number of cell migration was (3.20 ± 1.77) cells/HP in experimental group and (1.11 ± 0.49) cells/HP in control group, showing significant difference (t=4.230, P=0.001). In experimental group, the expressions of VCAM-1 mRNA increased with time and reached the peak at 7 days. There were significant differences in the expressions of VCAM-1 mRNA between control group and experimental group at 3, 5, and 7 days (P lt; 0.05). Immunocytochemistry results showed positive DAB staining for VEGF at 5 and 7 days in experimental group. Western blot results showed that the protein expressions of VEGF increased significantly at 5 and 7 days in experimental group when compared with control group (P lt; 0.05), which was signfiantly higher at 5 days than at 7 days in experimental group (P lt; 0.05). Conclusion CGRP can promote the migration of BMSCs and stimulate the protein expression of VEGF, which may plays an important role in regulating bone metabol ism by increasing angiogenesis.
Objective To study the expression changes of vascular endothel ial growth factor (VEGF), basic fibroblast growth factor (bFGF), and bone morphogenetic protein 2 (BMP-2) in femoral neck fracture, traumatic, and non-traumatic avascular necrosis of femoral head (ANFH), and to study the relationshi p between the expressions of VEGF, bFGF, BMP-2mRNA and bone mass so as to explore the pathogenesis of ANFH and provide the exprimental basis for individual treatment of ANFH. Methods Femoral head specimens were obtained from 59 donors undergoing total hip replacement, including 22 cases of traumatic ANFH (group A, 13 cases of Ficat stage III and 9 cases of Ficat stage IV), 19 cases of non-traumatic ANFH (group B, 11 cases of Ficat stage III and 8 cases of Ficat stage IV; 10 cases of steroid-induced ANFH, 7 cases of alcohol ic ANFH, and 2 cases of unexplained ANFH), and 18 cases of fresh femoral neck fracture (group C). There was no significant difference in the general data among 3 groups (P gt; 0.05). The bone mineral density (BMD) at weight-bearing area of the femoral head was measured with dual energy X-ray absorptiometry. The pathological changes were observed by using optical microscope and scanning electron microscope. The percentage of empty bone lacuna and the percentage of trabecular bone area were calculated. The expressions of VEGF, bFGF, and BMP-2 mRNA in femoral head were detected by use of in-situ hybridization technique. Results The BMD in groups A and B were significantly lower than that in group C (P lt; 0.05), and there was significant difference between group A and group B (P lt; 0.05). In the necrosis area of groups A and B, the bone trabecula was rarefactive and not of integrity, with a great number of empty bone lacuna. In healthy area, more fiber hyperplasia was observed in group A, the prol iferated and hypertrophic fat cells in the medullary cavity in group B. Scanning electron microscope showed that many osteocytes underwent fatty degeneration and necrosis, and that the prol iferation of fat cells in bone matrix was observed in groups A and B. While in group C, the femoral head had intact articular cartilage and intact bone trabeculae, and osteocytes were clearly seen. The percentage of empty bone lacuna was significantly higher (P lt; 0.05) and the percentage of trabecular bone area was significantly lower (P lt; 0.05) in groups A and B than group C; and there was significant difference in the percentage of empty bone lacuna between groups A and B (P lt; 0.05). The expressions of VEGF, bFGF, and BMP-2 mRNAwere significantly lower in groups A and B than group C (P lt; 0.05), and the expressions of BMP-2 and bFGF mRNA in group A were significantly higher than those in group B (P lt; 0.05). There were positive l inear correlation between the expressions of VEGF mRNA, bFGF mRNA, BMP-2 mRNA and the BMD and percentage of trabecular bone area, respectively. While there were significantly negative correlation between the expressions of VEGF mRNA, bFGF mRNA, BMP-2 mRNA and percentage of empty bone lacuna. Conclusion The repair capacity of local femoral head in traumatic ANFH is ber than that in non-traumatic ANFH. The expressions of VEGF mRNA, bFGF mRNA, and BMP-2 mRNA decl ine in traumatic and nontraumatic ANFH.
Objective To investigate the effect of bone marrow mesenchymal stem cells (BMSCs) transplantation on the motor function recovery, the expression of vascular endothel ial growth factor (VEGF) gene, and angiogenesis after spinal cord injury (SCI) in rats, and to explore the treatment mechanism of BMSCs in SCI. Methods BMSCs were isolated and cultured from the marrow of 5 Wistar rats (4 weeks old) and the 3rd-4th passage cells were prepared for the experiment. Atotal of 87 adult female Wistar rats (weighing 220-250 g) were randomly divided into 3 groups: sham-operated group (group A, n=21), DMEM group (group B, n=33), BMSCs group (group C, n=33). A laminectomy was only performed at T8-10 levels in group A. The SCI models were establ ished by modified Nystrom’s compression method in groups B and C, and BMSCs and DMEM were injected in groups B and C respectively at 30 minutes after SCI. Basso-Beattie-Bresnahan (BBB) score was used for the motor function recovery at 3, 7, 14, and 28 days, RT-PCR for the VEGF mRNA at 1, 3, and 5 days, and immunohistochemical staining for angiogenesis at 3, 7, 14, and 28 days. Results In groups B and C, the hindl imb locomotor function was improved at different degrees with time, showing significant difference in BBB score between groups B, C and group A (P lt; 0.05). At 28 days, the BBB score in group C was significantly higher than that in group B (P lt; 0.05) and there was no significant difference between groups B and C (P gt; 0.05) at 3, 7, and 14 days after transplantation. The numbers of microvessels in the ventral horns of gray matter around SCI in groups B and C were significantly lower than that in group C (P lt; 0.05) at 3 days, but there was no significant difference at 7, 14, and 28 days after transplantation (P gt; 0.05). There was no significant difference in the number of microvessels between group C and group B (P gt; 0.05) at 3 and 7 days, but the number of microvessels in group C was significantly higher than that in group B (P lt; 0.05) at 14 and 28 days after transplantation. However, there was no significant difference in the number of microvessels in the white matter around SCI in 3 groups at different time points after transplantation (P gt; 0.05). The RT-PCR results showed that VEGF mRNA expressed at a low level in group A. Compared with group A, the expression level of VEGF mRNA in groups B and C increased at 1 day and reached the peak at 3 days, then decreased at 5 days after transplantation; and the expression of VEGF mRNA was significantly higher in groups B and C than in group A (P lt; 0.05),and in group C than in group B (P lt; 0.05) at 1, 3, and 5 days. Conclusion BMSCs may promote the motor function recoveryby up-regulating VEGF mRNA expression and increasing angiogenesis in the spinal cord after SCI in rats.
Objective To investigate the expression levels and significance of vascular endothel ial growth factor (VEGF) and microvessel density (MVD) in rabbit radius defects repaired with allogeneic and autogenic bone. Methods Forty adult New Zealand rabbits were chosen, and 10 mm bone defect model was created in the bilateral radii of 28 experimental rabbits. The other 12 rabbits provided allogeneic bone under the standard of American Association of Tissue Bank. In the left side, allogeneic bone were used to repair bone defect (experimental group), equal capacity autogenous il iac bone was used in the right side (control group). Animals were sacrificed at 2, 4, 8, and 12 weeks postoperatively. Immunohistochemical method was used to determine the expression of VEGF, CD34 protein and MVD counting. Bone histomorphometric parameters, including percent trabecular area (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp) were measured by von Kossa staining undecalcified sl ices. The relation was analyzed between VEGF and MVD, histomorphometric parameters. Results The positive signals of VEGF protein were detected in cytoplasm of vascular endothel ial cells, chondrocytes, osteoblasts, fibroblasts and osteoclasts. At 2 weeks, there was no significant difference in VEGF protein expression between experimental group and control group (P gt; 0.05); at 4 and 8 weeks, the expression of VEGF in control group was significantly higher than that in experimental group (P lt; 0.05); and at 12 weeks, there was no significant difference between two groups (P gt; 0.05). There was a positive correlation (P lt; 0.01) between VEGF expression and MVD value in two groups at 2, 4, 8, and 12 weeks postoperatively. There was no significant difference in bone histomorphometric parameters (BV/TV, Tb.Th, Tb.N, Tb.Sp) between two groups at 12 weeks postoperatively (P gt; 0.05), but there was a positive correlation between VEGF expression and parameters of BV/TV, Tb.Th, and Tb.N (P lt; 0.01); and a negative correlation between VEGF and Tb.Sp (P lt; 0.01). Conclusion VEGF can express diversity at different time and positions, and the different expressions indicated various biology significances in the process of the bone heal ing. It can coordinate growth of cartilage and bone and profit vascular reconstruction of allogeneic bone. VEGF may participate in promoting osteogenesis in the course of allogeneic bone transplantation.
Objective To explore whether 125I-vascular endothel ial growth factor (VEGF)-coated artificial vascular patch accelerate the vessel endothel ial ization and inhibit thrombosis. Methods Ten adult male New Zealand rabbits (weighing 2.5-3.0 kg) were allocated into experimental group (n=5) and control group (n=5). In experimental group, the right common jugular vein was exposed for vascular clamping between proximal location and distal location, and then a 10 mm × 5 mm 125I-VEGF-coated artificial vascular patch was implanted into the right common jugular vein and sutured with 8-0 thread.In control group, the artificial vascular patch was implanted. After 2 weeks, the vein specimens were collected to measure the residues of 125I-VEGF by γ-ray counter. HE staining and immunohistochemical staining for smooth muscle actin (SMA) and CD34 were performed. The vascular endothel ial cells were counted and the intimal thickness was measured. Results The γ-ray counter showed the residues of 125I-VEGF in experimental group was (427.5 ± 194.9) CPM after 2 weeks, equivalent to 2.0% ± 0.8% of the preoperative value. Thrombosis formed in 2 rabbits of control group; no thrombosis formed in experimental group. There was significant difference in the intimal thickness [(41.1 ± 6.6) μm vs (49.0 ± 6.9) μm, P lt; 0.05]; but no significant difference in the vascular endothel ial cells count between experimental group and control group (60.0 ± 6.8 vs 58.0 ± 5.7, P gt; 0.05). Conclusion 125I-VEGF-coated artificial vascular patch can reduce thrombosis and inhibit intimal prol iferation at the acute phase. A consecutive l ine of endothel ial cells can form after implantation of patch in the rabbit jugular vein, however, the function of endothel ial cells may be premature.
Objective To explore the significance and the relationshi p between osteoporosis and the mRNA expressions of vascular endothel ial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) in nontraumatic avascular necrosis of the femoral head (NONFH), so as to provide a theoretical basis for the pathogenesis and the cl inical treatment of NONFH. Methods Sixty-nine specimens of femoral head were collected from voluntary donators undergoing total hi p arthroplasty, including 37 cases of NONFH (NONFH group) and 32 cases of fresh femoral neck fracture (control group). In NONFH group, there were 26 males and 11 females with an average age of 57.3 years (range, 43-75 years), including 19 cases of steroid-induced avascular necrosis of the femoral head (ANFH), 16 cases of alcohol ic ANFH, and 2 cases of idiopathicANFH; according to Ficat staging system, there were 23 cases at stage III and 14 cases at stage IV. In control group, there were 23 males and 9 females with an average age of 58.6 years (range, 46-79 years). The NO level of serum, the Q value of femur, and the bone mineral density (BMD) of weight-bearing area were measured firstly. The bone tissues were harvested from weightbearing necrosis area and healthy area. The pathological change was observed by HE staining, the percentage of empty bone lacuna and the percentage of trabecular bone area were calculated. The mRNA expressions of VEGF and BMP-2 in femoral head were detected through in situ hybridization technique. Results There were significant differences (P lt; 0.05) in the NO level of serum, the Q value of femur, and the BMD between NONFH group and control group. In NONFH group, the femoral head showed irregular shape, the articular cartilage exfol iated and collapsed. In weight-bearing necrosis area, the bone trabeculae were sparse and non-intact with a great number of empty lacuna; necrotic bone trabeculae were decomposed and absorbed; no obvious bone regeneration and repair were observed. In weight-bearing healthy area, the fat cells in bone marrow showed prol iferation and hypertrophy. In control group, the femoral head had normal appearance, intact articular cartilage, and intact bone trabeculae with a regular arrange, and osteocytes were clearly seen. There were significant differences in the percentage of empty bone lacuna and the percentage of trabecular bone area between NONFH group and control group (P lt; 0.05). The mRNA expressions of VEGF and BMP-2 were positive in 2 groups. The positive area ratio, the absorbance value, and integral absorbancevalue of VEGF mRNA and BMP-2 mRNA in NONFH group were significantly lower than those in control group (P lt; 0.05);the grey scales of VEGF mRNA and BMP-2 mRNA in NONFH group were significantly higher than that in control group (P lt;0.05). Conclusion The pathological stage of osteoporosis may play an important role in the mechanism of the NONFH. The decrease of mRNA expressions of VEGF and BMP-2 in femoral head of NONFH is important reason that affect its bone mass, osteoporosis, rehabil itation, and reconstruction. It may be benefit to the reparative process of the necrosis femoral head to increase the mRNA expressions of VEGF and BMP-2 in the femoral head.