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 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.
Objective To evaluate the mechanisms of p42/p44 kinase phosphorylation in cell models and to investigate the effect of simvastatin on the prevention and treatment of aseptic loosening of prosthesis by observing the influence of simvastatin on the levels of tumor necrosis factor α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1) of human peri pheral blood mononuclear cell (PBMC) challenged with titanium particles. Methods PBMC from 45 mL peripheral blood of healthy adult voluntary donators, were separated and cultured, and divided into 5 groups according to different culturemedium: group A, PBMC and titanium particles; group B, PBMC and titanium particles with 1 × 10-5 mol/L simvastatin; group C, PBMC and titanium particles with 1 × 10-6 mol/L simvastatin; group D, PBMC and titanium particles with 1 × 10-7 mol/L simvastatin; and group E, PBMC and titanium particles with the extracellular signal-regulated kinase (ERK1/2) inhibitor U0126. The contents of TNF-α and MCP-1 were tested by ELISA after 24 hours of culture. PBMC were pretreated with different medium grouping as groups A, B, C, D, and E for 60 minutes, and were challenged with titanium particles for 30 minutes and 60 minutes, then the level of ERK1/2 expression was tested by Western blot. Results In groups A, B, C, D, and E, the absorbance (A) values of TNF-α were 1.115 5 ± 0.243 6, 0.693 6 ± 0.354 3, 0.695 7 ± 0.387 3, 0.716 4 ± 0.478 9, and 0.263 5 ± 0.101 6, respectively; and the A values of MCP-1 were 1.421 0 ± 0.105 3, 0.915 1 ± 0.411 3, 1.003 5 ± 0.464 2, 1.102 0 ± 0.353 9, and 0.271 3 ± 0.145 1, respectively. The levels of TNF-α and MCP-1 in group A were significantly higher than others, showing significant differences (P lt; 0.05). There were significant differences between group E and groups B, C, and D (P lt; 0.05), between group B and groups C, D (P lt; 0.05); no significant difference between group C and group D (P gt; 0.05). Western blot results showed the expression of ERK1/2 in all groups at 30 minutes and 60 minutes of culture. The levels of ERK1/2 expression were 1.612 1 ± 0.068 2, 1.078 1 ± 0.072 8, 1.268 7 ± 0.223 1, 1.439 7 ± 0.180 1, and 0.732 0 ± 0.110 4 in groups A, B, C, D, and E, respectively; showing significant differences between groups (P lt; 0.05). Conclusion ERK1/2 is a phosphorylated protein after stimulated by wear particles; it is also one of the most important cell signal ing activation of macrophage. Simvastatin can inhibit the expression of bone absorptive factors induced by wear particles and may be used in the prevention and treatment of aseptic loosening of prosthesis.
Objective To investigate the effects of simvastatin on pulmonary function and vascular endothelial growth factor ( VEGF) levels in induced sputumof patients with COPD exacerbation( AECOPD) .Methods Thirty-eight patients with AECOPD were divided into two groups randomly, ie. a routine medical treatment( RT) group( n =30) and a routine + statin medical treatment( RST) group( n =28) . The VEGF levels in serumand induced sputum were detected by ELISA on the first day and after a week treatment in hospital, respectively. Meanwhile, the pulmonary function measurements were performed. Results There were no significant differences in the pulmonary function ( FEV1% pred and FEV1 /FVC) and VEGF levels in induced sputumbetween the two groups before treatment( P gt;0. 05) . The RT group showed no significantchanges in any parameters before and after a week treatment( P gt; 0. 05) . FEV1% pread, FEV1 /FVC and VEGF levels in induced sputum in the RST group after a week treatment significantly increased compared with those before treatment and the RT group( P lt;0. 01, P lt;0. 01, P lt;0. 05) . But There were no significant differences in serumVEGF levels between the two groups before and after a week treatment. The VEGF levels in induced sputum were positively correlated to FEV1% pread and FEV1 /FVC after a week treatment( r =0. 430, P lt;0. 05; r = 0. 388, P lt; 0. 05) . Conclusions Simvastatin may reduce the decline in pulmonary function and decrease the levels of VEGF in induced sputum of patients with AECOPD. Improvement in pulmonary function may be related to down-expression of lung VEGF
Objective To investigate the effects of simvastatin on monocrotaline-induced pulmonary hypertension in rats, and explore the potential mechanism of simvastatin by blocking heme oxygenase-1( HO-1) expression. Methods 52 male Sprague-Dawley rats were randomly divided into five groups, ie. a control group, a simvastatin control group, a pulmonary hypertension model group, a simvastatin treatment group, a ZnPP ( chemical inhibitor of HO) group. Mean pulmonary arterial pressure ( mPAP) and right ventricular systolic pressure ( RVSP) were detected by right heart catheter at 5th week. 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 analysis system.Immunohistochemical analysis was used to investigate the expression and location of HO-1. HO-1 protein level in lung tissue were determined by western blot. Results Compared with the model group, simvastatin treatment decreased mPAP and RVHI significantly [ ( 35. 63 ±5. 10) mm Hg vs. ( 65. 78 ±15. 51) mm Hg,0. 33 ±0. 05 vs. 0. 53 ±0. 06, both P lt; 0. 05 ] . Moreover, simvastatin treatment partially reversed the increase of arterial wall area and arterial wall diameter [ ( 50. 78 ±9. 03 ) % vs. ( 65. 92 ±7. 19) % ,( 43. 75 ±4. 23) % vs. ( 52. 00 ±5. 35) % , both P lt; 0. 01) . In the model group, HO-1 staining was primarily detected in alveolar macrophages. Simvastatin treatment increased HO-1 protein expression significantly, especially in the thickened smooth muscle layer and alveolar macrophages. Inhibiting HO-1 expression using ZnPP resulted in a loss of the effects of simvastatin. mPAP in the ZnPP group was ( 52. 88±17. 45) mm Hg, while arterial wall area and arterial wall diameter were ( 50. 78 ±9. 03) % and ( 52. 00 ±5. 35) % , respectively. Conclusions Simvastatin attenuates established pulmonary arterial hypertension andpulmonary artery remodeling in monocrotaline-induced pulmonary hypertension rats. The effect of simvastatin is associated with HO-1.
