Objective To investigate the effect of simvastatin on inducing endothel ial progenitor cells (EPCs) homing and promoting bone defect repair, and to explore the mechanism of local implanting simvastatin in promoting bone formation. Methods Simvastatin (50 mg) compounded with polylactic acid (PLA, 200 mg) or only PLA (200 mg) was dissolved in acetone (1 mL) to prepare implanted materials (Simvastatin-PLA material, PLA material). EPCs were harvested from bone marrow of 2 male rabbits and cultured with M199; after identified by immunohistochemistry, the cell suspension of EPCs at the 3rd generation (2 × 106 cells/mL) was prepared and transplanted into 12 female rabbits through auricular veins(2 mL). After 3 days, the models of cranial defect with 15 cm diameter were made in the 12 female rabbits. And the defects were repaired with Simvastatin-PLA materials (experimental group, n=6) and PLA materials (control group, n=6), respectively. The bone repair was observed after 8 weeks of operation by gross appearance, X-ray film, and histology; gelatin-ink perfusion and HE staining were used to show the new vessels formation in the defect. Fluorescence in situ hybridization (FISH) was performed to show the EPCs homing at the defect site. Results All experimental animals of 2 groups survived to the end of the experiment. After 8 weeks in experimental group, new bone formation was observed in the bone defect by gross and histology, and an irregular, hyperdense shadow by X-ray film; no similar changes were observed in control group. FISH showed that the male EPC containing Y chromosome was found in the wall of new vessels in the defect of experimental group, while no male EPC containing Y chromosome was found in control group. The percentage of new bone formation in defect area was 91.63% ± 4.07% in experimental group and 59.45% ± 5.43% in control group, showing significant difference (P lt; 0.05). Conclusion Simvastatin can promote bone defect repair, and its mechanism is probably associated with inducing EPCs homing and enhancing vasculogenesis.
Objective To find an ideal material for repairing bone defect by local implanting simvastatin compounded with poly-lactic acid (PLA) into the radial critical size defects of rabbits, and to observe the reparative effect and type of bone formation induced by simvastatin. Methods Twelve 4-months-old male New Zealand white rabbits (2.3-2.8 kg) with 22 mm radial critical size defects on both sides were randomized into 4 groups (all n=3). Right side and left side of every rabbit were set as controls with each other. The left defects (experimental groups) of groups A, B, and C were implanted with cyl inder-l ike compound scaffolds containing 50, 100, and 200 mg of simvastatin (fixed with 250 mg PLA), or auto-bonegraft as group D, respectively. The right defects of groups A, B, and C were implanted with scaffolds containing only 250 mg PLA. The right defects of group D were left without any treatment. Digital X-ray images of bone defects were taken 8 and 16 weeks after operation, X-ray was scored double bl ind and X-ray pixel value was measured. Animals were euthanized16 weeks postoperatively. CT was appl ied to analyze new bone formation volume in the defects. In addition, orphologicalcharacters of new bones were observed through micro-CT and histology. Results X-ray films showed that the bone defect of each experimental side had much cloud-l ike callus, and the bone stump were not clear 8 weeks after operation; and the cortex in the defect was continuous and the medullary was recanal ized 16 weeks after operation. In control sides, the cortexes were discontinuous and the ends of fractures were sclerified. At 8 and 16 weeks after operation, the X-ray scores, pixel values and the CT volume percentage of new bone in experiment sides were all significantly higher than those in control sides (P lt; 0.05). The X-ray scores of experimental sides in groups C and D were significantly higher than those in groups A and B 8 weeks after operation (P lt; 0.05), and the X-ray scores of experimental sides in groups B and D were significantly higher than those in groups A and C 16 weeks after operation (P lt; 0.05). The X-ray pixel values of experimental sides of group B were significantly higher than those of groups A, C, and D 8 weeks after operation (P lt; 0.05). The new bone formation volume of experimental side of groups B and D was higher than that of groups A and C (P lt; 0.05), and group D was significantly higher than that of group B (P lt; 0.05). Micro-CT showed bone defects of experimental sides of group B had totally healed, with connected medullary cavities and continuous bone cortex, on the contrary bone defects of control sides of group B did not healed completely. Histological observation showed better bone remodeling effects of the experimental sides than control sides, with connected medullary cavities and continuous bone cortex. And the osteogenetic type was endochondral ossification. Conclusion Local implantation of simvastatin can promote repairing rabbit radial critical bone defect, 100 mg is the best dose of repairing the bone defects.
ObjectiveTo investigate the regulatory effect of simvastatin on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) at middle/late stages by p38MAPK pathway under condition of osteoinductive environment.
MethodsThe bone marrow of bilateral femur and tibia were harvested from 20 4-week-old female Sprague Dawley rats. BMSCs were isolated and cultured with whole bone marrow culture method; the second generation of cells were randomly divided into 5 groups: control group (complete medium, CM), simvastatin group (simvastatin medium, SIM), osteogenic induction group (osteogenic induction medium, OM), simvastatin and osteogenic induction group (simvastatin+osteogenic induction medium, OM+SIM), and blocker group (SB203580+simvastatin+osteogenic induction medium, OM+SIM+SB). MTT assay was used to detect the cell activity in CM group and SIM group at 2, 3, 4, 5, and 6 days, ELISA method to measure the content of alkaline phosphatase (ALP) in OM group and OM+SIM group at 7 and 14 days. The mRNA and protein expressions of osteocalcin (OCN) were detected by real-time quatitative PCR and Western blot after 1, 12, and 24 hours of osteogenic induction at 21 and 28 days. The protein expressions of phospho-p38 (p-p38) and p38 in OM group, OM+SIM group, and OM+SIM+SB group were detected by Western blot at the best induction time of simvastatin.
ResultsMTT assay showed that no significant difference was found in absorbance (A) value between CM group and SIM group at each time point (P > 0.05), indicating no effect of 1×10-7 mol/L simvastatin on cell viability. ELISA results showed that ALP content significantly increased in OM+SIM group when compared with OM group at 7 and 14 days; the ALP content was significantly higher at 7 days than 14 days in OM group and OM+SIM group (P < 0.05). OCN mRNA and protein expressions at 12 hours were significantly higher than those at other time points in each group (P < 0.05), and the expressions of OM+SIM group was significantly higher than those of OM group (P < 0.05). The best induction time of simvastatin was 12 hours. At 12 hours after blocking intervention, the p-p38/p38 in OM+SIM+SB group was significantly lower than that in OM group and OM+SIM group (P < 0.05), and the p-p38/p38 in OM+SIM group was significantly higher than that in OM group (P < 0.05).
ConclusionSimvastatin can increase the mRNA and protein expression levels of OCN and the protein of p-p38 in osteogenic differentiation of BMSCs at middle/ late stages, and its best induction time is 12 hours.
ObjectiveTo explore the effects of simvastatin on the expression of matrix metalloproteinase (MMP) and inflammatory factors in rats with smoke-induced chronic obstructive pulmonary disease (COPD).
Methods40 male Wistar rats were randomly divided into four groups, including a normal group (group A), a simvastatin group (group B), a COPD model group (group C) and a simvastatin intervention group (group D). The COPD model of the group C and D were induced through exposing to the cigarette smoke repeatedly. At the same time, the rats of group B and D were given by gavage 5 mg/(kg·d) with simvastatin, and the other two groups were given with the same volume saline for 16 weeks. Pulmonary function tests and pathological examination of the lung tissue were performed after the induction of COPD model. Enzyme-linked immunosorbent assay (ELISA) method was used to measure the content of MMP-2, MMP-9, IL-6, IL-8, TNF-α in lung tissue homogenate.
ResultsThe airway resistance of group C and group D was significantly higher than the group A and group B (P<0.01), and the airway resistance of group D was significantly lower than group C (P<0.01). The degree of bronchial inflammation and emphysema of group C was more apparent than group D in the pathological section, and there were no bronchial inflammation and emphysema in group A and group B. The ELISA results showed that the contents of MMP-2, MMP-9, IL-6, IL-8, TNF-α in group C were all significantly higher than those in group D.
ConclusionSimvastatin has inhibitory effect on pulmonary inflammation of COPD, and can reduce the expression of matrix metalloproteinase and inflammatory factors in the lung.
Objective To evaluate the effectiveness and safety of simvastatin 40 mg daily use in treatment of coronary heart disease. Methods The study was designed as before-after study in the same patients. One hundred and sixty seven patients with coronary heart disease were prescribed simvastatin 40 mg daily for 3 and 6 months. Total cholestero (TC), low-density lipoproteins cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerldes (TG), ALT and creatine kinase (CK) in serum before therapy and at the end of 3 months and 6 months treatment were dectected. Continuous data were analyzed by standard difference of blocked randomization and described by mean±SD. Dunnet-t test was used for multiple comparison of trial and control groups. Statistical difference was set up at P＜0.05. Success rate was assessed by chi square test at the end of 3 and 6 months treatment. Results Simvastatin 40 mg/d significantly decreased the level of TC (P＜0.000 5), LDL-C (P＜0.000 5), TG (P＜0.05), and could elevate HDL-C (P＜0.05). There were 39.5% of patients whose LDL-C reduced below 70 mg/dl. One patient whose CK raised 5.6 times of upper line of normal range and 4 patients whose ALT raised more than 2 times of upper line of normal range withdrew. The reliability of simvastatin 40 mg/d was relatively good. Conclusions Simvastatin 40 mg/d could significantly improve the lipid profile, and is relatively reliable in treatment of coronary heart disease.
Objective To investigate the effects of simvastatin on the collagen synthesis of rat pulmonary arterial smooth muscle cells ( PASMCs ) induced by hypoxia. Methods Under hypoxic condition, rat PASMCs were cultured with different concentrations of simvastatin. Collagen synthesis of PASMCs with or without simvastatin were measured by 3H-proline incorporation assay. The mRNA expression of TGF-β1 and the contents of super oxide dismrtase ( SOD) ,malondialdehyde ( MDA) in mediumwere also measured. Results The incorporation data of 3H-TdR in the hypoxia group was significantly increased as compared with that in the control group ( P lt;0. 01) , and simvastatin significantly reduced the incorporation data of 3H-TdR induced by hypoxia. The expression of TGF-β1 mRNA in the hypoxia group was significantly increased as compared with that in the control group ( P lt; 0. 01 ) , and simvastatin could significantly inhibited hypoxia-induced expression of TGF-β1 mRNA in a dose-dependent manner. Compared with the hypoxia group, the expression of TGF-β1 mRNA decreased by 55% in simvastatin( 10 - 6mol /L) group ( P lt; 0. 01) , and by 70% ( P lt; 0. 01) in simvastatin ( 10 - 5mol /L) group. Compared with the control group, the activity of SOD was reduced and the contents of MDA were increased significantly in the hypoxia group. Simvastatin can increase the activity of SOD and reduced the content of MDA in a dose-dependent manner. Conclusions Simvastatin can decreases collagen synthesis of PASMCs. This effect might be explained that simvastatin can reduce lipid peroxide and expression of TGF-β1 mRNA.
Objective To investigative the effects of combination treatment with simvastatin and aspirin in a rat model of monocrotaline-induced pulmonary hypertension. Methods Sixty male Sprague-Dawley rats were randomly divided into a control group, a simvastatin group, an aspirin group, and a combination treatment group. The control group received monocrotaline injection subcutaneously to induce pulmonary hypertension. Simvastatin ( 2 mg/kg) , aspirin ( 1 mg/kg) , or simvastatin ( 2 mg/kg) + aspirin ( 1 mg/kg) was administered once daily to the rats of treatment groups respectively for 28 days after monocrotaline injection. Mean pulmonary arterial pressure ( mPAP) was detected by right heart catheter.Right ventricular hypertrophy index ( RVHI) was calculated as the right ventricle to the left ventricle plus septum weight. Histopathology changes of small intrapulmonary arteries were evaluated via image analysissystem. Interleukin-6 ( IL-6) level in lung tissue was determined by ELISA.Results Compared with the control group, simvastatin or aspirin decreased mPAP [ ( 34. 1 ±8. 4) mm Hg, ( 38. 3 ±7. 1) mmHg vs.( 48. 4 ±7. 8) mmHg] and increased arterial wall diameter significantly ( P lt; 0. 05) . The combination treatment group showed more significant improvement in mPAP, RVHI and pulmonary arterial remodeling compared with each monotherapy ( P lt;0. 05) . Moreover, the combination therapy had additive effects on the increases in lung IL-6 levels and the perivascular inflammation score. Conclusions Combination therapy with simvastatin and aspirin is superior in preventing the development of pulmonary hypertension. The additive effect of combination therapy is suggested to be ascribed to anti-inflammation effects.
OBJECTIVE: To study the effect of simvastatin on the expression of bone morphogenetic protein-2 (BMP-2) and alkaline phosphates (ALP) activity in the primary cultured bone marrow stromal cells, and to elucidate the mechanism of the anabolic osteogenetic effect of simvastatin. METHODS: Bone marrow stromal cells in femur and tibia of adult mouse were cultured in vitro. after treated with different concentrations of simvastatin (0, 0.1, 0.2, 0.5 and 1.0 mumol/L) or recombinant human BMP-2 for 72 hours, ALP activity of bone marrow stromal cells was determined. BMP-2 expression of bone marrow stromal cells was analyzed by using immunocytochemistry and Western blotting. RESULTS: After treated with simvastatin for 72 hours, BMP-2 expression increased, while little BMP-2 expression could be observed in the control group. ALP activity also increased in a dose-dependent manner; t-test showed that ALP activity in the group which concentrations of simvastatin were 0.5 mumol/L (t = 2.35, P = 0.041), 1.0 mumol/L (t = 2.348, P = 0.041) had significant difference when compared with control group. CONCLUSION: Simvastatin lead to high expression of BMP-2 in bone marrow stromal cells, via the increased auto- or para-crine of BMP-2, and ALP activity increased. These may be parts of the mechanism on the anabolic osteogenetic effect of simvastatin.
Objective To confirm the stimulating effect of simvastatin on BMSCs of SD rats osteogenic differentiation, and to further study the role of Wnt signal ing pathway in this process. Methods BMSCs derived from the tibia and femur of 6-week-old female SD rats were cultured in vitro．Two groups were establ ished: control group and experimental group. After the 2nd passage, the cells of experimental group were treated with simvastatin (1 × 10-7mol/L) and the cells of control group with absolute ethyl alcohol and PBS. ALP staining was used at 7 days and von Kossa staining was appl ied at 28 days to assess osteoblastic differentiation and mineral ization. Real-time quantitative PCR was performed to evaluate theexpressions of Axin2, β-catenin, osteocalcin (OC), frizzled-2, Lef-1, and Wnt5a mRNA at 7 days and 14 days after simvastatin treatment. Results The observation of inverted phase contrast microscope showed that the majority of cells were polygonal and triangular in the experimental group, and were spindle-shaped in the control group at 7 days. The ALP staining showed blue cytoplasm, the positive cells for ALP staining in the experimental group were more than those in the control group at 7 days. The von Kossa staining showed that mineral ization of extracelluar matrix at 28 days in two groups, but the mineral ization in the experimental group was more obvious than that in the control group. The expression of Axin2 mRNA was significantly lower, and frizzled-2, Lef-1 mRNA were significantly higher in the experimental group than in the control group (P lt; 0.05) at 7 days, while the mRNA expressions of Axin2, OC, frizzled-2, Lef-1, and Wnt5a were significantly higher in the experimental group than in the control group at 14 days (P lt; 0.05). Conclusion Simvastatin can promote the osteogenic differentiation of BMSCs and change the expression of mRNA of some components of Wnt signal ing pathway.
Objective To investigate the effects of simvastatin on lung tissue in septic rats by observing the protein expression of nuclear factor kappa B ( NF-κB) and pathologic changes in lung tissue at different time points. Methods 90 healthy male Sprague-Dawley rats were randomly divided into three groups ( n =30 in each group) . All the rats received administration by caudal vein and capacity volume is 2 mL. The rats in the control group were treated with saline ( 2 mL) . The rats in the LPS group were treated with LPS ( 5 mg/kg ) . The rats in the simvastatin group were treated with LPS ( 5 mg/kg) and simvastatin ( 20 mg/kg) . Six rats in each group were killed randomly at 2, 4, 6, and 12 hours after the injection, and the right middle lobe of lung was taken out. Pathological changes of lung tissue wee investigated under light microscope. The expression of NF-κB in lung tissue was determined by immunohistochemistry ( IHC) method. Results Microscopic studies showed that there were not pathological changes in the lung tissue of rats in the control group. While in the LPS group, the alveolar spaces were narrowed and the alveolar wall were thickened. Furthermore, severe interstitial edema of lung and proliferation of epithelial cells were observed. In the simvastatin group, the degree of the infiltration of leukocytes and the lung interstitial edema were less severe than those in the simvastatin group. In the control group, the expression of NF-κB protein in most of lung tissue was negative. In the LPS group, the expression of NF-κB protein was detected at 2h, andreached the peak at 6h, then decreased at 12h. In the Simvastatin group, the NF-κB expression was significantly lower than that in the LPS group at all time points ( P lt; 0. 01) . Conclusion Simvastatin can ameliorate pathological lesions and decrease expression of NF-κB in lung tissue of septic rats.
