Locally delivered lovastatin nanoparticles enhance fracture healing in rats.

Statins stimulate bone formation in vitro and in vivo and, when given in large doses or by prolonged infusions, stimulate biomechanical strength of murine long bones with healing fractures. However, administration of statins by large oral doses or prolonged infusions to a fracture site is not a feasible therapeutic approach to hasten healing of human fractures. We administered lovastatin in biodegradable polymer nanobeads of poly(lactic-co-glycolide acid) to determine if lovastatin delivered in low doses in nanoparticles of a therapeutically acceptable scaffold could increase rates of healing in a standard preclinical model of femoral fracture. We found that these nanobeads: (1) stimulated bone formation in vitro at 5 ng/mL, (2) increased rates of healing in femoral fractures when administered as a single injection into the fracture site, and (3) decreased cortical fracture gap at 4 weeks as assessed by microcomputed tomography. These preclinical results suggest that lovastatin administered in a nanobead preparation may be therapeutically useful in hastening repair of human fractures.     

Effect of lovastatin, an HMG CoA reductase inhibitor, on acute renal allograft rejection

3-Hydroxy-3-methyl glutaryl coenzyme A (HMG CoA) reductase inhibitors are established anti-lipidemic agents. They also exert immunomodulatory effects. Two recent reports suggest that pravastatin may be useful in decreasing the incidence and severity of acute rejections (ARs) in heart and kidney transplant recipients. We undertook this prospective, randomized, placebo-controlled, double blind trial to investigate the effect of lovastatin on acute renal allograft rejection. Sixty-five consecutive, one-haplotype-matched, living related first renal transplant recipients were randomized to receive either lovastatin 20 mg/d or placebo for 3 months, in addition to cyclosporine, azathioprine, and steroids. Lipid levels, AR episodes, and liver and muscle enzymes were followed for 3 months post-transplant. At the end of the study period, lovastatin had successfully controlled lipid levels. However, there was no effect on AR episodes (15.15% in the treatment group vs. 18.75% in the placebo group).     

High-intensity statin therapy reduces risk of amputation and reintervention among patients undergoing lower extremity bypass for chronic limb-threatening ischemia

ObjectiveStatins are considered standard-of-care medical therapy for patients undergoing lower extremity bypass (LEB) procedures for chronic limb-threatening ischemia (CLTI). It is unclear, however, whether up-titrating and maintaining patients on higher-intensity statin medications following LEB improves limb salvage outcomes. This study was designed to evaluate whether high-intensity statin therapy impacts the risk of amputation and reintervention following LEB for patients with CLTI.MethodsThe IBM MarketScan database was used to identify adult patients (18-99 years old) who underwent a LEB for CLTI between 2008 and 2017. Patients lacking insurance covering drug reimbursement or those who already had undergone amputation before time of bypass were excluded. Using pharmacy claims and national drug codes to define statin intensity, patients were stratified into three groups: high-intensity, low-intensity, and limited statin therapy. The association between intensity of statin therapy and need for reintervention and/or major amputation after LEB was analyzed using Kaplan-Meier curves and risk-adjusted Cox proportional hazard models.ResultsA total of 25,907 patients who underwent LEB for CLTI were identified, of which 6696 (26%) were maintained on high-dose statins, 9297 (36%) were on low-dose statins, and 9914 (38%) had inconsistent pharmacy claims for statin therapy after surgery. Patients on high-intensity statins were, on average, younger and more likely to be male with comorbid disease (diabetes, hypertension, hyperlipidemia, obesity, renal insufficiency, ischemic heart disease, cerebrovascular disease, and tobacco abuse) than patients on low-intensity statins or limited statin therapy (P < .001 for all comparisons). Following LEB, 6649 patients (25.6%) required a reintervention, and 2550 patients (9.8%) went on to have a major amputation during follow-up. Patients maintained on high-intensity statins after LEB had a significantly lower likelihood of requiring a reintervention (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.45-0.51; P < .001) or amputation (HR, 0.27; 95% CI, 0.24-0.30; P < .001) as compared with patients on limited statin therapy. Further, there was a dose-dependent effect for these outcomes relative to patients on low-intensity statins in risk-adjusted models, and it was independent of whether an autologous vein graft was used for the LEB. Finally, among patients who underwent a reintervention, high-dose statin therapy also significantly reduced the HR for subsequent amputation (HR, 0.21; 95% CI, 0.18-0.25; P < .001).ConclusionsPatients with CLTI on high-intensity therapy following LEB had a significantly lower risk of requiring subsequent reintervention and amputation when compared with patients on low-intensity statins or with limited statin use. These data suggest that patients with CLTI should be up-titrated and/or maintained on high-intensity statins following revascularization whenever possible.     

羟甲基戊二酰辅酶A还原酶抑制剂对多囊肾病囊肿衬里上皮细胞增殖抑制及其机制的研究

目的 探讨羟甲基戊二酷辅酶 Ａ（ＨＭＧ ＣｏＡ）还原酶抑制剂对常染色体显性遗传型多囊肾病（ＡＤＰＫＤ）囊肿衬里上皮细胞的作用及其机制。方法 噻唑蓝（ＭＴＴ）法检测细胞增殖，免疫印迹法检测细胞膜ｐ２１ｒａｓ的表达．免疫细胞化学检测细胞核ｃ－ｆｏｓ、ｃ－ｊｕｎ的表达。结果ＡＤＰＫＤ囊肿衬里上皮细胞经 ＨＭＧ ＣｏＡ还原酶抑制剂处理后，细胞增殖受到显著抑制（Ｐ＜０．０１），细胞膜 ｐ２１ｒａｓ蛋白表达下调，细胞核ｃ－ｆｏｓ、ｃ－ｊｕｎ的表达显著下降（Ｐ＜０．０１）。结论 ＨＭＣ ＣｏＡ还原酶抑制剂能抑制ＡＤＰＫＤ囊肿衬里上皮细胞的增殖，其机制可能与抑制细胞内ｒａｓ蛋白的异戊二烯化并阻断ｒｓ介导的信号转导有关。     

Effect of preoperative statin therapy on postoperative acute kidney injury in patients undergoing major surgery: Systemic review and meta‐analysis

We aimed to examine the association between preoperative use of statins and postoperative acute kidney injury (AKI) in patients undergoing major surgery by performing a systemic review and meta‐analysis. MEDLINE and EMBASE, from inception to April 2013, and the reference lists of related articles were searched for relevant studies. Trials comparing preoperative statin therapy with no preoperative statin in patients undergoing major surgery were included. Outcome measures of interest were the risk of cumulative postoperative AKI and postoperative AKI requiring renal replacement therapy (RRT). Fixed or random effect meta‐analysis was performed to derive summary effect estimates. In five randomized controlled trials (RCTs) and 19 observational studies, comprising a total of 989 173 patients undergoing major surgery, 112 840 patients (11.41%) received preoperative statin therapy. The specific type, dosage, and duration of statin therapy were not available in most studies. Preoperative statin therapy was associated with a significant risk reduction for cumulative postoperative AKI (weighted summary odds ratio (OR) 0.87, 95% CI 0.79 to 0.95). The effect of risk reduction was also significant when considering postoperative AKI requiring RRT (OR 0.80, 95% CI 0.72 to 0.90). When restricting the analysis to the five RCTs, preoperative statin therapy did not show significant protective effect on postoperative AKI (OR 0.49, 95% CI 0.22 to 1.09). In patients undergoing major surgery, preoperative statin therapy could associate with a reduced risk for postoperative AKI. However, considerable heterogeneity existed among included studies. Future randomized trials were warranted for this critical clinical question.     

骨碎补柚皮苷对炎症及骨作用的相关研究进展

柚皮苷广泛存在于各类植物中,是中药骨碎补的重要组成成分,目前柚皮苷还处于实验研究阶段,已有的实验结论证实了柚皮苷可通过降低炎症因子的表达,实现抑制包括骨关节炎症在内的各种炎症反应的作用,并认为其作用的分子机制是抑制NF-κB通路。此外,柚皮苷通过提高BMP-2蛋白和抑制RANKL的表达实现促进成骨细胞增殖分化和抑制破骨细胞活性的作用。动物实验中柚皮苷对骨质疏松症的治疗有效,其相关机制研究正在深入。     

Impact of single‐dose nandrolone decanoate on gonadotropins,blood lipids and HMG CoA reductase in healthy men

The aim was to study the effect and time profile of a single dose of nandrolone decanoate (ND) on gonadotropins, blood lipids and HMG CoA reductase [3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase (HMGCR)] in healthy men. Eleven healthy male participants aged 29–46 years were given a single dose of 150 mg ND as an intramuscular dose of Deca Durabol®, Organon. Blood samples for sex hormones, lipids and HMGCR mRNA analysis were collected prior to ND administration day 0, 4 and 14. A significant suppression of luteinising hormone (LH) and follicle‐stimulating hormone (FSH) was seen after 4 days. Total testosterone and bioavailable testosterone level decreased significantly throughout the observed study period. A small but significant decrease in sexual hormone‐binding globulin (SHBG) was seen after 4 days but not after 14 days. Total serum (S)‐cholesterol and plasma (P)‐apolipoprotein B (ApoB) increased significantly after 14 days. In 80% of the individuals, the HMGCR mRNA level was increased 4 days after the ND administration. Our results show that a single dose of 150 mg ND increases (1) HMGCR mRNA expression, (2) total S‐cholesterol and (3) P‐ApoB level. The long‐term consequences on cardiovascular risk that may appear in users remain to be elucidated.     

Promotion of bone formation by naringin in a titanium particle‐induced diabetic murine calvarial osteolysis model

Diabetic patients have an increased risk of prosthesis failure requiring revision surgery. Furthermore, skeletal defects are observed in conjunction with type 1 diabetes. Using a titanium particle‐induced calvarial osteolysis model in diabetic mice, we investigated the effect of diabetes on the osteolytic process and the role of naringin in its prevention. Three groups each of nondiabetic or diabetic mice were treated with vehicle only, with particles only, or with particles then naringin for 10 days. Alteration of bone indices near the midline suture were then analyzed by microcomputed tomography scanning and histology. Serum levels of osteocalcin (OCN) and cross‐linked N‐telopeptide of type I collagen (NTx) were measured by enzyme‐linked immunosorbent assay. The decreases in new bone formation (p < 0.05), calvaria thickness (p < 0.05), bone volume (p < 0.05), midline suture area (p < 0.05), and OCN concentration (p < 0.05) found in diabetic mice were normalized with naringin treatment. Diabetic state promoted particle‐induced osteolysis. Naringin, an osteoanabolic agent, improved bone indices apparently by stimulating bone formation. Therefore, naringin may be beneficial in preventing and treating debris‐mediated periprosthetic osteolysis after total joint replacement, especially in diabetics. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:451–456, 2010     

Pilot double-blind, randomized controlled trial of short-term atorvastatin for prevention of acute kidney injury after cardiac surgery

Aim: To test whether short‐term perioperative administration of oral atorvastatin could reduce incidence of postoperative acute kidney injury (AKI) in cardiac surgical patients. Methods: We conducted a double‐blind, randomized controlled trial in 100 cardiac surgical patients at increased risk of postoperative AKI. Patients were randomized to atorvastatin (40 mg once daily for 4 days starting preoperatively) or identical placebo capsule. Primary outcome was to detect a smaller absolute rise in postoperative creatinine with statin therapy. Secondary outcomes included AKI defined by the creatinine criteria of RIFLE consensus classification (RIFLE R, I or F), change in urinary neutrophil gelatinase‐associated lipocalin (NGAL) concentration, requirement for renal replacement therapy, length of stay in intensive care, length of stay in hospital and hospital mortality. Results: Study groups were well matched. For each patient maximal increase in creatinine during the 5 days after surgery was assessed; median maximal increase was 28 µmol/L in the atorvastatin group and 29.5 µmol/L in the placebo group (P = 0.62). RIFLE R or greater occurred in 26% of patients with atorvastatin and 32% with placebo (P = 0.65). Postoperatively urine NGAL changes were similar (median NGAL : creatinine ratio at intensive care unit admission: atorvastatin group 1503 ng/mg, placebo group 1101 ng/mg; P = 0.22). Treatment was well tolerated and adverse events were similar between groups. Conclusion: Short‐term perioperative atorvastatin use was not associated with a reduced incidence of postoperative AKI or smaller increases in urinary NGAL. (ClinicalTrials.gov NCT00910221).     

Transdermal application of lovastatin to rats causes profound increases in bone formation and plasma concentrations

Introduction Statins are drugs that inhibit HMG Co-A reductase and have been shown to enhance bone formation in vitro and in vivo in rodents. However, the statins currently used for cholesterol-lowering have been selected for their capacity to target the liver where their effects on cholesterol synthesis are mediated and they undergo first pass metabolism. When given in lipid-lowering doses, these agents do not likely reach sufficient blood concentrations to reliably cause substantial increases in bone formation in humans. Moreover, statins are inactivated by cytochrome P450 enzymes, resulting in even less peripheral distribution of the biologically active moieties beyond the liver. Method To investigate whether an alternate method of administration might produce beneficial effects on bone formation, we administered lovastatin by dermal application to rats to circumvent the first-pass effects of the gut wall and liver. Results We found that the statin blood levels measured by HMG Co-A reductase activity were higher, maintained longer and less variable following transdermal application than those following oral administration. Also the increased circulating statin levels were associated with significantly enhanced biological effects on bone. After only 5 days of administration of transdermal lovastatin to rats, there was a 30–60% increase in trabecular bone volume, and 4 weeks later, we observed more than a 150% increase in bone formation rates. There was also a significant increase in serum osteocalcin, a marker of bone formation. We also found that lovastatin administered transdermally produces these profound effects at doses in the range of 1% of the oral dose, without any evidence of the hepatotoxicity or myotoxicity that can occur following oral statin administration. Several doses (0.01–5 mg kg⁻¹ day⁻¹) and dosage schedules were examined, and collectively the data strongly suggest a powerful anabolic effect but with an unusually flat dose-response curve. Conclusion These results show transdermal application of statins produces greater beneficial effects on bone formation than oral administration does. GE Gutierrez, IR Garrett, G Rossini and GR Mundy are all employees of and hold stock in OsteoScreen Ltd.     

Antihyperlipidemic Effect of Curcumin and Tetrahydrocurcumin in Experimental Type 2 Diabetic Rats

Hyperlipidemia is an associated complication of diabetes mellitus. In the present study, we investigated the effect of tetrahydrocurcumin (THC), one of the active metabolites of curcumin on lipid profile in streptozotocin (STZ)-nicotinamide-induced diabetic rats. THC 80mg/kg body weight was orally administered to diabetic rats for 45 days, resulting in a significant reduction in blood glucose and a significant increase in plasma insulin in diabetic rats, which proved that THC possess an antidiabetic effect. THC also caused a significant reduction serum and liver cholesterol, triglycerides, free fatty acids, phospholipids, HMG CoA reductase activity, very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) cholesterol levels. The decreased serum high-density lipoprotein (HDL) cholesterol in diabetic rats was also reversed toward normalization after the treatment. These biochemical observations were supplemented by histopathological examination of liver section. The effect was compared with curcumin (80 mg/kg body weight). The results showed that THC had antihyperlipidemic action in control and experimental diabetic rats. The antidiabetic and antihyperlipidemic effects of THC are more potent than those of curcumin at the same dose.     

miR-21对骨质疏松小鼠骨髓基质细胞增殖的影响

目的探讨miR-21对骨质疏松小鼠骨髓基质细胞(BMSCs)增殖的影响。方法采用双侧卵巢切除法构建骨质疏松小鼠模型(VOX),分离、培养、纯化小鼠BMSCs并采用si PORT Neo FX转染pre-miR-21、pre-miR-negative control(pre-miR-NC)、antmiR-21、ant-miR-negative control(ant-miR-NC)并进行RT-PCR验证,MTT法检测小鼠BMSCs增殖情况、茜素红与碱性磷酸酶染色法检测小鼠BMSCs成骨能力、Western-blotting检测细胞增殖、成骨分化相关蛋白水平。结果骨质疏松症小鼠BMSCs中miR-21相对表达水平低于Ctrl组(P0.05),OVX-pre-miR-21组BMSCs中miR-21相对表达水平、细胞增殖、PCNA水平、Ki-67水平、ALP染色程度、ALP活性、茜素红染色程度、Runx2水平、Osterix水平均高于OVX-pre-miR-NC组(P0.05),OVX-premiR-NC组BMSCs中miR-21相对表达水平、细胞增殖、PCNA水平、Ki-67水平、ALP染色程度、ALP活性、茜素红染色程度、Runx2水平、Osterix水平均显著低于Ctrl-pre-miR-NC(P0.05); OVX-ant-miR-21组BMSCs中miR-21相对表达水平、细胞增殖、PCNA水平、Ki-67水平、ALP染色程度、ALP活性、茜素红染色程度、Runx2水平、Osterix水平均显著低于OVX-ant-miR-NC组(P0.05),OVX-ant-miR-NC组BMSCs中miR-21相对表达水平、细胞增殖、PCNA水平、Ki-67水平、ALP染色程度、ALP活性、茜素红染色程度、Runx2水平、Osterix水平均显著低于Ctrl-ant-miR-NC(P0.05)。结论提高miR-21表达水平可促进骨质疏松小鼠BMSCs增殖能力与成骨分化能力。     

Allogenic peripheral blood derived mesenchymal stem cells (MSCs) enhance bone regeneration in rabbit ulna critical-sized bone defect model.

Mesenchymal stem cells (MSCs) were demonstrated to exist within peripheral blood (PB) of several mammalian species including human, guinea pig, mice, rat, and rabbit. Whether or not the PB derived MSCs (PBMSCs) could enhance the regeneration of large bone defects have not been reported. In this study, rabbit MSCs were obtained from mononuclear cells (MNCs) cultures of both the PB and bone marrow (BM) origin. The number of PBMSCs was relatively lower, with the colony forming efficiency (CFE) ranging from 1.2 to 13 per million MNCs. Under specific inductive conditions, PBMSCs differentiated into osteoblasts, chondrocytes, and adipocytes, showing multidifferentiation ability similar to BMMSCs. Bilateral 20 mm critical-sized bone defects were created in the ulnae of 12 6-month-old New Zealand white rabbits. The defects were treated with allogenic PBMSCs/Skelite (porous calcium phosphate resorbable substitute), BMMSCs/Skelite, PBMNCs/Skelite, Skelite alone, and left empty for 12 weeks. Bone regeneration was evaluated by serial radiography, peripheral quantitative computed tomography (pQCT), and histological examinations. The X-ray scores and the pQCT total bone mineral density in the PBMSCs/Skelite and BMMSCs/Skelite treated groups were significantly greater than those of the PBMNCs/Skelite and Skelite alone groups ( p < 0.05), respectively. Histologically, newly formed bone was evident in the PBMSCs/Skelite and BMMSCs/Skelite treated groups. The findings demonstrated that the rabbit PBMSCs possessed multidifferentiation potential comparable with BMMSCs, allogenic PBMSCs seeded onto porous calcium phosphate resorbable substitutes enhanced bone regeneration in the rabbit ulna critical-sized bone defect model, suggesting allogenic PBMSCs may be a new source of circulating osteogenic stem cells for bone regeneration and tissue engineering.     

骨质疏松症的治疗及柚皮苷抗骨质疏松的研究进展

骨质疏松症是一种常见的代谢性疾病,典型的病理改变是全身骨量降低以及骨微结构的退化和破坏,骨质疏松性骨折是其严重的并发症。随着人口老龄化进展,骨质疏松症,尤其是最常见的绝经后骨质疏松,给全球公共卫生事业带来极大的经济负担,同时也严重影响了患者自身的生活质量。当前普遍认为治疗骨质疏松的关键在于恢复机体内骨代谢的动态平衡,而细胞之间的信号通路是研究的关键。随着新的信号通路不断出现,以其为作用靶点的新型药物也层出不穷,本文初步综述了近年来骨质疏松症的流行病学特点、目前的主要诊断技术、经典药物及新型药物的作用机制,以及从中药骨碎补中提取的单体化合物柚皮苷治疗骨质疏松症的研究进展。