Zoledronate inhibits the proliferation, adhesion and migration of vascular smooth muscle cells

Nitrogen-containing bisphosphonate for vascular calcification: animal experiments, systematic review and meta-analysis

BACKGROUND

The purpose of our study was to explore the effect of nitrogen-containing bisphosphonate (N-BP) on vascular calcification (VC) through animal experiments and a meta-analysis.

METHODS

In our animal experiments, Sprague-Dawley (SD) rats were randomly divided into a control group, a VC group, a low-dose zoledronic acid (ZOL) (20 µg/kg) group and a high-dose ZOL (100 µg/kg) group. The calcification of the aortic arch was observed by alizarin red staining. The calcium content of the aortic arch was measured. In our systematic review and meta-analysis, databases, including PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure (CNKI), and the Wanfang database, were searched from their inception to December 20, 2023. Eligible studies comparing N-BP versus no N-BP in the treatment of VC were included.

RESULTS

In our animal experiment, the red-stained calcification structure in the low-dose ZOL group was slightly reduced and the red-stained calcification structure in the high-dose ZOL group was significantly reduced compared with that in the VC. The calcium content in the low-dose ZOL group was slightly lower than that in the VC group, but the difference was not significant (P = 0.08). The calcium content in the high-dose ZOL group was significantly lower than that in the VC group (P < 0.0001). Our meta-analysis of human studies revealed that N-BP did not reduce the arterial calcification score (P = 0.46). Our meta-analysis of animal studies revealed that N-BP did not significantly reduce the arterial calcification score (P = 0.09), but N-BP reduced the arterial calcification area (P < 0.00001), arterial calcium content (P = 0.009) and PO4 content (P = 0.0001).

CONCLUSIONS

Our animal experiment revealed that high-dose ZOL inhibited VC, but low-dose ZOL did not significantly inhibit VC. Our meta-analysis of human studies revealed that N-BP was not effective in the treatment of VC, but our meta-analysis of animal studies suggested a role of N-BP in inhibiting VC.

Risk of glaucoma with bisphosphonate use in patients with osteoporosis: a case-control study

PURPOSE

Bisphosphonates (BPs) are first line agents commonly used in the management of osteoporosis. There have been two case reports that have suggested a possible link between BPs and acute angle closure (AAC). In the absence of any large epidemiologic studies, we sought to determine the risk of AAC and OAG with bisphosphonate use in patients with osteoporosis.

METHODS

This was a retrospective cohort study with a case control analysis from 2008-2018. The study used the PharMetrics Plus Database (IQVIA, USA) which captures health claims for over 150 million unique patients, with fully adjudicated pharmacy and medical claims, and represents all geographic areas of the United States. 208,111 patients with osteoporosis were included in the study. AAC and OAG cases were defined by an ICD-9/10 code and had to have at least one prescription for bisphosphonate every 3 months in the year prior to the index date. The date of the first event of AAC was designated as the index date.

RESULTS

Bisphosphonate users were more likely to develop AAC than non-users (adjusted IRR = 1.78, 95%CI [1.05-3.01]). In particular, those on risedronate were more likely to develop AAC compared to patients who used other formulations of bisphosphonates (adjusted IRRs = 2.12, 95%CI [1.05-3.01]). There was no risk for OAG with bisphosphonate use.

CONCLUSIONS

Patients with osteoporosis who used BPs were at a higher risk for AAC compared to those who did not, and those who were on risedronate were more likely to develop AAC compared to patients who used other types of bisphosphonates.

Nitrogen-containing bisphosphonate induces enhancement of OPG expression and inhibition of RANKL expression via inhibition of farnesyl pyrophosphate synthase to inhibit the osteogenic differentiation and calcification in vascular smooth muscle cells

BACKGROUND

Nitrogen-containing bisphosphonate(N-BP)had been found to inhibit the osteogenic differentiation and calcification in vascular smooth muscle cells (VSMCs), but the mechanism is not clear. We intend to verify that N-BP induces enhancement of OPG expression and inhibition of RANKL expression via inhibition of farnesyl pyrophosphate synthase(FPPS) to inhibit the osteogenic differentiation and calcification in VSMCs.

METHODS

β-glycerophosphate (β-GP) was used to induce the osteogenic differentiation and calcification in VSMCs. VSMCs were treated with N-BP or pretreated with downstream products of farnesyl pyrophosphate synthase(FPPS) in mevalonate pathway, such as farnesol (FOH) or geranylgeraniol (GGOH). Alizarin red S staining and determination of calcium content were used to detect calcium deposition.Western Blotting were used to detect expressions of proteins(OPG and RANKL ) and osteogenic marker proteins (Runx2 and OPN).

RESULTS

β-GP induced the osteogenic differentiation and calcification in VSMCs, increased RANKL protein expression and had no significant effect on OPG protein expression. With the treatment of N-BP, the expression of OPG protein was increased and expression of RANKL protein was decreased in VSMCs undergoing osteogenic differentiation and calcification. In addition, N-BP reduced the osteogenic marker proteins (Runx2 and OPN) expression and calcium deposition in VSMCs undergoing osteogenic differentiation and calcification. These effects of N-BP on the osteogenic differentiation and calcification in VSMCs were concentration-dependent, which could be reversed by the downstream products of FPPS, such as FOH or GGOH.

CONCLUSION

N-BP increases OPG expression and decreases RANKL expression via inhibition of FPPS to inhibit the osteogenic differentiation and calcification in VSMCs.

CXCL9, IL2RB, and SPP1, potential diagnostic biomarkers in the co-morbidity pattern of atherosclerosis and non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is a hepatocyte inflammation based on hepatocellular steatosis, yet there is no effective drug treatment. Atherosclerosis (AS) is caused by lipid deposition in the endothelium, which can lead to various cardiovascular diseases. NASH and AS share common risk factors, and NASH can also elevate the risk of AS, causing a higher morbidity and mortality rate for atherosclerotic heart disease. Therefore, timely detection and diagnosis of NASH and AS are particularly important. In this study, differential gene expression analysis and weighted gene co-expression network analysis were performed on the AS (GSE100927) and NASH (GSE89632) datasets to obtain common crosstalk genes, respectively. Then, candidate Hub genes were screened using four topological algorithms and externally validated in the GSE43292 and GSE63067 datasets to obtain Hub genes. Furthermore, immune infiltration analysis and gene set variation analysis were performed on the Hub genes to explore the underlying mechanisms. The DGIbd database was used to screen candidate drugs for AS and NASH. Finally, a NASH model was constructed using free fatty acid-induced human L02 cells, an AS model was constructed using lipopolysaccharide-induced HUVECs, and a co-morbidity model was constructed using L02 cells and HUVECs to verify Hub gene expression. The result showed that a total of 113 genes common to both AS and NASH were identified as crosstalk genes, and enrichment analysis indicated that these genes were mainly involved in the regulation of immune and metabolism-related pathways. 28 candidate Hub genes were screened according to four topological algorithms, and CXCL9, IL2RB, and SPP1 were identified as Hub genes after in vitro experiments and external dataset validation. The ROC curves and SVM modeling demonstrated the good diagnostic efficacy of these three Hub genes. In addition, the Hub genes are strongly associated with immune cell infiltration, especially macrophages and γ-δ T cell infiltration. Finally, five potential therapeutic drugs were identified. has-miR-185 and hsa-miR-335 were closely related to AS and NASH. This study demonstrates that CXCL9, IL2RB, and SPP1 may serve as potential biomarkers for the diagnosis of the co-morbidity patterns of AS and NASH and as potential targets for drug therapy.

Non-nitrogen-containing bisphosphonates and nitrogen-containing bisphosphonates for the treatment of atherosclerosis and vascular calcification: A meta-analysis

BACKGROUND

The role of non-nitrogen-containing bisphosphonates (non-N-BPs) and nitrogen-containing bisphosphonates (N-BPs) in the treatment of atherosclerosis (AS) and vascular calcification (VC) is uncertain. This meta-analysis was conducted to evaluate the efficacy of non-N-BPs and N-BPs in the treatment of AS and VC.

METHODS

The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and Wanfang databases were searched from their inception to July 5th, 2023. Eligible studies comparing bisphosphonates (BPs) versus no BPs in the treatment of AS and VC were included. The data were analyzed using Review Manager Version 5.3.

RESULTS

Seventeen studies were included in this meta-analysis. Twelve were randomized control trials (RCTs), and 5 were nonrandomized studies. Overall, 813 patients were included in the BPs group, and 821 patients were included in the no BPs group. Compared with no BP treatment, non-N-BP or N-BP treatment did not affect serum calcium (P > .05), phosphorus (P > .05) or parathyroid hormone (PTH) levels (P > .05). Regarding the effect on serum lipids, non-N-BPs decreased the serum total cholesterol (TC) level (P < .05) and increased the serum triglyceride (TG) level (P < .01) but did not affect the serum low-density lipoprotein cholesterol (LDL-C) level (P > .05). N-BPs did not affect serum TC (P > .05), TG (P > .05) or LDL-C levels (P > .05). Regarding the effect on AS, non-N-BPs did not have a beneficial effect (P > .05). N-BPs had a beneficial effect on AS, including reducing the intima-media thickness (IMT) (P < .05) and plaque area (P < .01). For the effect on VC, non-N-BPs had a beneficial effect (P < .01), but N-BPs did not have a beneficial effect (P > .05).

CONCLUSION

Non-N-BPs and N-BPs did not affect serum calcium, phosphorus or PTH levels. Non-N-BPs decreased serum TC levels and increased serum TG levels. N-BPs did not affect serum lipid levels. Non-N-BPs had a beneficial effect on VC, and N-BPs had a beneficial effect on AS.

Cardiovascular benefits and risks associated with calcium, vitamin D, and antiresorptive therapy in the management of skeletal fragility

Osteoporosis affects one in every five women over the age of 50 worldwide. With a rapidly ageing population, the prevalence of fragility fractures, considered a largely preventable consequence of osteoporosis, is expected to increase. Age is also a major risk for cardiovascular disease and mortality, thus highlighting the importance of cardiovascular profiling of osteoporosis interventions. Although calcium and vitamin D are essential for a healthy bone metabolism, excessive supplementation may be associated with increased risk. Conversely, early pre-clinical data have suggested a possible cardiovascular benefit from bisphosphonate therapy. This review evaluates the evidence behind the cardiovascular benefits and risks that may be associated with osteoporosis therapy.

A Review Into the Effects of Pamidronic Acid and Zoledronic Acid on the Oral Mucosa in Medication-Related Osteonecrosis of the Jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a growing problem without an effective treatment, presenting as necrotic bone sections exposed via lesions in the overlying soft tissue. There is currently a lack of clarity on how the factors involved in MRONJ development and progression contribute to disease prognosis and outcomes. Bisphosphonates (BPs), the most common cause of MRONJ, affect bone remodeling, angiogenesis, infection, inflammation and soft tissue toxicity, all of which contribute to MRONJ development. This article reviews the cellular mechanisms through which BPs contribute to MRONJ pathology, with a focus on the effects on cells of the oral mucosa. BPs have been shown to reduce cell viability, reduce proliferation, and increase apoptosis in oral keratinocytes and fibroblasts. BPs have also been demonstrated to reduce epithelial thickness and prevent epithelial formation in three-dimensional tissue engineered models of the oral mucosa. This combination of factors demonstrates how BPs lead to the reduced wound healing seen in MRONJ and begins to uncover the mechanisms through which these effects occur. The evidence presented here supports identification of targets which can be used to develop novel treatment strategies to promote soft tissue wound healing and restore mucosal coverage of exposed bone in MRONJ.

Effects of zoledronic acid on osteonecrosis and acute lymphoblastic leukemia treatment efficacy in preclinical models

BACKGROUND

Osteonecrosis is a devastating side effect of acute lymphoblastic leukemia (ALL) therapy. Associations between bone density loss and osteonecrosis have sparked interest in using bisphosphonates to reduce this complication.

PROCEDURE

We assessed the impact of zoledronic acid (ZA) on the development of osteonecrosis in murine models when used either throughout therapy (continuous administration) or late in therapy after vascular lesions have developed but before osteonecrosis has occurred. Effects on bone density were measured using microcomputed tomography (μCT)-assessed tibial cortical thickness, while osteonecrosis was assessed histologically in the distal femur. Effects on antileukemic efficacy of chemotherapy were evaluated in both immunocompetent/syngeneic and patient-derived xenograft (PDX) models.

RESULTS

Continuous administration of ZA with chemotherapy prevented chemotherapy-associated bone loss (p < .001) and reduced osteonecrosis (p = .048). Late initiation of ZA diminished bone loss (p < .001) but had no impact on the development of osteonecrosis (p = .93). In the immunocompetent murine ALL model, mice treated with ZA and chemotherapy succumbed to leukemia sooner than mice treated with chemotherapy alone (p = .046). Analysis using PDX showed a nonsignificant decrease in survival with ZA (p = .17).

CONCLUSION

Our data indicate ZA may prevent osteonecrosis if begun with chemotherapy but showed no benefit when administered later in therapy. However, ZA may also reduce the antileukemic efficacy of chemotherapy.

Zoledronate alters natural progression of tissue-engineered vascular grafts

Macrophages are a critical driver of neovessel formation in tissue-engineered vascular grafts (TEVGs), but also contribute to graft stenosis, a leading clinical trial complication. Macrophage depletion via liposomal delivery of clodronate, a first-generation bisphosphonate, mitigates stenosis, but simultaneously leads to a complete lack of tissue development in TEVGs. This result and the associated difficulty of utilizing liposomal delivery means that clodronate may not be an ideal means of preventing graft stenosis. Newer generation bisphosphonates, such as zoledronate, may have differential effects on graft development with more facile drug delivery. We sought to examine the effect of zoledronate on TEVG neotissue formation and its potential application for mitigating TEVG stenosis. Thus, mice implanted with TEVGs received zoledronate or no treatment and were monitored by serial ultrasound for graft dilation and stenosis. After two weeks, TEVGs were explanted for histological examination. The overall graft area and remaining graft material (polyglycolic-acid) were higher in the zoledronate treatment group. These effects were associated with a corresponding decrease in macrophage infiltration. In addition, zoledronate affected the deposition of collagen in TEVGs, specifically, total and mature collagen. These differences may be, in part, explained by a depletion of leukocytes within the bone marrow that subsequently led to a decrease in the number of tissue-infiltrating macrophages. TEVGs from zoledronate-treated mice demonstrated a significantly greater degree of smooth muscle cell presence. There was no statistical difference in graft patency between treatment and control groups. While zoledronate led to a decrease in the number of macrophages in the TEVGs, the severity of stenosis appears to have increased significantly. Zoledronate treatment demonstrates that the process of smooth muscle cell-mediated neointimal hyperplasia may occur separately from a macrophage-mediated mechanism.

Targeting Small GTPases and Their Prenylation in Diabetes Mellitus

A fundamental role of pancreatic β-cells to maintain proper blood glucose level is controlled by the Ras superfamily of small GTPases that undergo post-translational modifications, including prenylation. This covalent attachment with either a farnesyl or a geranylgeranyl group controls their localization, activity, and protein–protein interactions. Small GTPases are critical in maintaining glucose homeostasis acting in the pancreas and metabolically active tissues such as skeletal muscles, liver, or adipocytes. Hyperglycemia-induced upregulation of small GTPases suggests that inhibition of these pathways deserves to be considered as a potential therapeutic approach in treating T2D. This Perspective presents how inhibition of various points in the mevalonate pathway might affect protein prenylation and functioning of diabetes-affected tissues and contribute to chronic inflammation involved in diabetes mellitus (T2D) development. We also demonstrate the currently available molecular tools to decipher the mechanisms linking the mevalonate pathway’s enzymes and GTPases with diabetes.

Key Enzymes for the Mevalonate Pathway in the Cardiovascular System

ABSTRACT

Isoprenylation is an important post-transcriptional modification of small GTPases required for their activation and function. Isoprenoids, including farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate, are indispensable for isoprenylation by serving as donors of a prenyl moiety to small G proteins. In the human body, isoprenoids are mainly generated by the mevalonate pathway (also known as the cholesterol-synthesis pathway). The hydroxymethylglutaryl coenzyme A reductase catalyzes the first rate-limiting steps of the mevalonate pathway, and its inhibitor (statins) are widely used as lipid-lowering agents. In addition, the FPP synthase is also of critical importance for the regulation of the isoprenoids production, for which the inhibitor is mainly used in the treatment of osteoporosis. Synthetic FPP can be further used to generate geranylgeranyl pyrophosphate and cholesterol. Recent studies suggest a role for isoprenoids in the genesis and development of cardiovascular disorders, such as pathological cardiac hypertrophy, fibrosis, endothelial dysfunction, and fibrotic responses of smooth-muscle cells. Furthermore, statins and FPP synthase inhibitors have also been applied for the management of heart failure and other cardiovascular diseases rather than their clinical use for hyperlipidemia or bone diseases. In this review, we focus on the function of several critical enzymes, including hydroxymethylglutaryl coenzyme A reductase, FPP synthase, farnesyltransferase, and geranylgeranyltransferase in the mevalonate pathway which are involved in regulating the generation of isoprenoids and isoprenylation of small GTPases, and their pathophysiological role in the cardiovascular system. Moreover, we summarize recent research into applications of statins and the FPP synthase inhibitors to treat cardiovascular diseases, rather than for their traditional indications respectively.

Effects of bisphosphonates on osteoporosis: Focus on zoledronate

Osteoporosis is a bone disease that mainly affects older people and postmenopausal women. Lack of proper treatment for this disease gives rise to many problems in patients and occasionally leads to death. Many drugs have been utilized to treat osteoporosis but the most effective one is the bisphosphonates (BPs) family. This family has several positive effects on bone tissue, including promoting bone healing, enhancing bone mineral density, reducing bone resorption, preventing pathologic fractures, suppressing bone turnover, and modulating bone remodeling. On the other hand, there have also been inconclusive reports that BPs might have a desirable or even adverse impact on osteoporotic patients. Therefore, we set out to examine the positive and negative effects of this family, with a focus on the most potent one that is zoledronate (Zol), in clinical usage. Zoledronate is an amino-BPs and nitrogen-containing drug which is the most powerful BPs on osteoporosis treatment or prevention. Many studies showed its effectiveness in the treatment of osteoporosis and bone healing. As Zol enjoys a considerable potential in treating and preventing osteoporosis, it can be used as one of the effective treatments in this field.

Once-yearly zoledronic acid and change in abdominal aortic calcification over 3 years in postmenopausal women with osteoporosis: results from the HORIZON Pivotal Fracture Trial

This study evaluated whether zoledronic acid (ZA) inhibited the progression of abdominal aortic calcification (AAC) over 3 years in 502 postmenopausal women with osteoporosis. AAC progressed in a similar proportion of participants in the ZA (29%) and placebo (31%) groups, suggesting no effect of ZA on AAC progression.

INTRODUCTION

Bisphosphonate use is associated with reduced risk of all-cause mortality and cardiovascular events. The underlying mechanisms are uncertain but may include effects on vascular calcification. This study aimed to evaluate the effect of zoledronic acid (ZA) on abdominal aortic calcification (AAC) in postmenopausal women with osteoporosis.

METHODS

This was a post hoc analysis of the HORIZON Pivotal Fracture Trial that included 502 postmenopausal women (mean age 72.5 years) with osteoporosis (234 received ZA and 268 placebo). AAC scores (range, 0-8) were assessed from paired spine X-rays at baseline and after 3 years. Progression of AAC was defined as any increase in AAC score. The association between change in hip and femoral neck bone mineral density and change in AAC score was also assessed.

RESULTS

At baseline, 292 (58.2%) participants had AAC (i.e., AAC score > 0), with AAC scores similar in the two intervention groups (median [interquartile range], 1 [0 to 2] for both; p = 0.98). Over 3 years, AAC progressed in a similar proportion of participants in both groups (ZA 29% and placebo 31%; p = 0.64). Change in bone mineral density and change in AAC score were not correlated.

CONCLUSION

Once-yearly zoledronic acid did not affect progression of AAC over 3 years in postmenopausal women with osteoporosis.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00049829.

Bisphosphonate use and incident cardiovascular events among older breast cancer survivors

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of mortality in early-stage breast cancer survivors. Recent studies suggest that bisphosphonates may decrease CVD risk in older patients.

OBJECTIVE

This study sought to assess whether bisphosphonate use is associated with lower rates of incident CVD events among early-stage breast cancer survivors.

METHODS

Longitudinal, population-based cohort study was conducted by using data from the Surveillance, Epidemiology and End Results registry linked to Medicare claims. We identified women >65 years with no history of CVD who were diagnosed with stage 0-III primary breast cancer between 2007 and 2010. Our primary outcome was a composite of incident angina pectoris, myocardial infarction, atrial fibrillation/flutter, heart failure, or stroke within 36 months of cancer diagnosis. Bisphosphonate use was defined as the presence of ≥1 pharmacy claim from 6 months prior to cancer diagnosis to the incident CVD event. We used propensity scores to create a matched group of breast cancer survivors without bisphosphonate exposure to compare rates of incident CVD events.

RESULTS

A total of 2178 breast cancer survivors had ≥1 bisphosphonate prescription; the average length of bisphosphonate use was 15 months. Analyses of the matched data showed that 13.0% of bisphosphonate users and 23.4% of non-bisphosphonate users experienced an incident CVD event (p < 0.0001) after breast cancer diagnosis. Bisphosphonate use was significantly associated with fewer incident CVD events (hazard ratio: 0.51, 95% confidence interval: 0.44 to 0.59).

CONCLUSIONS

Bisphosphonate use is associated with lower incidence of CVD events among older early-stage breast cancer survivors. Future studies should prospectively evaluate whether bisphosphonate use can decrease CVD incidence.

Atherosclerosis and Osteoporosis. Common Targets for the Effects of Cardiovascular and Anti-Osteoporotic Drugs (Part II). The Effect of Antiosteoporotic Drugs on the Vascular Wall State

In the second part of the literature review, data are presented on the possible effect of anti-osteoporosis therapy on the vascular wall and the development of calcification. The discovery of common biological substances involved in the development of atherosclerosis, calcification of the vascular wall and osteoporosis attracts the attention of scientists in terms of targets for assessing the effects of already known drugs or developing new drugs that can simultaneously prevent or slow the progression of both atherosclerosis and osteoporosis. Currently, various groups of drugs for the treatment of osteoporosis have been studied to prevent or reduce the progression of subclinical atherosclerosis and calcification. Both antiresorptive drugs (bisphosphonates, monoclonal antibodies to RANKL, selective estrogen receptor modulators), and bone-anabolic therapy, which includes teriparatide, were studied. However, there are a few such studies and the most promising drugs that have a preventive effect in the early stages of atherosclerotic damage are bisphosphonates. Other classes of antiosteoporotic drugs did not reveal a positive effect on the vascular wall, and some of them increased the cardiovascular risk. Divergences in the results of experimental and clinical studies attract attention. If in the experiment almost all drugs for the treatment of osteoporosis had an atheroprotective effect and suppressed vascular calcification, then in clinical conditions only bisphosphonates confirmed the positive effect on the vascular wall.

Zoledronate inhibits fibroblasts' proliferation and activation via targeting TGF-β signaling pathway

Background

Previous preclinical and clinical studies have demonstrated that zoledronate might inhibit neointimal hyperplasia at least partly by inhibiting the proliferation, adhesion and migration of vascular smooth muscle cells (VSMCs). However, whether zoledronate influences fibroblasts’ proliferation and activation, which also play a key role in neointimal hyperplasia and vascular remodeling, remains largely unknown. In the present study, the effect of zoledronate on fibroblasts was investigated and the underlying molecular mechanisms were examined.

Methods

After treatment with zoledronate, changes in biological behaviors, including the morphology, proliferation, cell-cycle distribution and migration of fibroblasts (NIH3T3 cells), were observed. The expression of α-SMA, TGF-β1 and TGF-β2 and the level of Smad2/3 phosphorylation in cultured fibroblasts were examined by Western blot. In vivo expression of α-SMA and TGF-β1 was assessed by immunohistochemical staining.

Results

It was shown that the typical fibroblast cell morphology was altered after zoledronate exposure. Cultured fibroblasts treated with zoledronate displayed dose-dependent inhibition of cell proliferation due to cell-cycle arrest in the S phase. Cell migration activities were also dose dependently suppressed by zoledronate treatment. Expression of α-SMA in cultured fibroblasts was significantly reduced by zoledronate treatment. Further analysis showed decreased expression of TGF-β1 and α-SMA by periadventitial delivery of zoledronate in the rat carotid balloon-injury model. The expression of TGF-β1 and TGF-β2 and the phosphorylation of Smad2/3 in cultured fibroblasts were significantly inhibited by zoledronate treatment.

Conclusion

Our findings demonstrated that zoledronate can inhibit the proliferation, migration and activation of fibroblasts via the TGF-β signaling pathway and revealed a novel mechanism of zoledronate action against neointimal hyperplasia.

Vascular action of bisphosphonates: In vitro effect of alendronate on the regulation of cellular events involved in vessel pathogenesis

In this work we investigate whether, despite the procalcific action of alendronate on bone, the drug would be able to regulate in vitro the main cellular events that take part in atherosclerotic lesion generation. Using endothelial cell cultures we showed that Alendronate (1-50μM) acutely enhances nitric oxide production (10-30min). This stimulatory action of the bisphosphonate involves the participation of MAPK signaling transduction pathway. Under inflammatory stress, the drug reduces monocytes and platelets interactions with endothelial cells induced by lipopolysaccharide. Indeed the bisphophonate exhibits a significant inhibition of endothelial dependent platelet aggregation. The molecular mechanism of alendronate (ALN) on leukocyte adhesion depends on the regulation of the expression of cell adhesion related genes (VCAM-1; ICAM-1); meanwhile the antiplatelet activity is associated with the effect of the drug on nitric oxide production. On vascular smooth muscle cells, the drug exhibits ability to decrease osteogenic transdifferentiation and extracellular matrix mineralization. When vascular smooth muscle cells were cultured in osteogenic medium for 21days, they exhibited an upregulation of calcification markers (RUNX2 and TNAP), high alkaline phosphatase activity and a great amount of mineralization nodules. ALN treatment significantly down-regulates mRNA levels of osteoblasts markers; diminishes alkaline phosphatase activity and reduces the extracellular calcium deposition. The effect of ALN on vascular cells differs from its own bone action. On calvarial osteoblasts ALN induces cell proliferation, enhances alkaline phosphatase activity, and increases mineralization, but does not affect nitric oxide synthesis. Our results support the hypothesis that ALN is an active drug at vascular level that regulates key processes involved in vascular pathogenesis through a direct action on vessel cells.

Zoledronate upregulates MMP-9 and -13 in rat vascular smooth muscle cells by inducing oxidative stress

Background

Bisphosphonates, including zoledronate, target osteoclasts and are widely used in the treatment of osteoporosis and other bone resorption diseases, despite side effects that include damaging the stomach epithelium. Beneficial and adverse effects on other organ systems, including the cardiovascular system, have also been described and could impact on the use of bisphosphonates as therapeutic agents. Vascular smooth muscle cells (VSMCs) are major constituents of the normal vascular wall and have a key role in intimal thickening and atherosclerosis, in part by secreting MMPs that remodel the extracellular matrix and cleave cell surface proteins or secreted mediators. In this study, we investigated the effects of zoledronate on MMP expression.

Methods

Rat VSMCs were stimulated by PDGF (50 ng/mL) plus TNF-α (10 ng/mL) or left unstimulated for a further 24 hours in serum-free medium. In other series of experiments, cells were pre-treated either with SC-514 (50 μM) or with apocynin (20 nM) for 2 hours, then zoledronate (100 μM) was added into 2% fetal calf serum containing medium for 24 hours.

Results and discussion

Using isolated rat VSMCs in culture, zoledronate (100 μM) increased MMP-9 and -13 mRNA expressions but inhibited MMP-2 expression. MMP-9 and MMP-13 up-regulation was shown to depend on the NF-κB pathway; and this was activated by zoledronate. Furthermore, zoledronate elevated the levels of reactive oxygen species detected by either dichlorofluorescein in isolated VSMCs or lucigenin enhanced chemiluminescence in rat aortic rings in vitro. Apocynin, an inhibitor of NADPH oxidase, reversed NF-κB activation and MMP-9 and MMP-13 up-regulation by zoledronate.

Conclusion

We conclude that zoledronate increases MMP-9 and MMP-13 expressions in rat VSMCs dependent upon stimulation of the NF-κB pathway by reactive oxygen species. Effects on MMP expression may contribute to the pharmacologic profile of bisphosphonates.

Adverse cardiovascular effects of nitrogen-containing bisphosphonates in patients with osteoporosis: A nationwide population-based retrospective study

BACKGROUND

Bisphosphonates (BPs) are a class of medications used for the treatment of osteoporosis. Nitrogen-containing BPs (N-BPs) are more potent than non-nitrogenous BPs in terms of their effects on osteoporosis. We examined the effects of N-BPs on osteoporosis in patients included in a large population-based cohort study.

METHODS

Based on the National Health Insurance Research Database of Taiwan, we identified 1258 patients with osteoporosis who had received N-BP treatment from 2005 through 2010.

RESULTS

During the retrospective observation period, N-BP users had significantly higher incidence rates of hypertension, acute ischemic stroke, atrial fibrillation (Af), and congestive heart failure (CHF), and lower rates of hyperlipidemia than patients who did not use N-BPs. Overall, N-BP users had a higher incidence of cardiovascular events at the end of the follow-up period. After adjustment for age, sex, and comorbidities, the risk of developing cardiovascular events was significantly high for patients using N-BPs. Patients who received N-BP therapy also had a higher risk of Af and CHF than those who did not during the five-year follow-up period.

CONCLUSION

We provide evidence that patients with osteoporosis using N-BP therapy have an increased risk of CHF and Af. This potential risk should be weighed against the reduction in the risk of osteoporotic fractures.

The Regulation of Matrix Metalloproteinase Expression and the Role of Discoidin Domain Receptor 1/2 Signalling in Zoledronate-treated PC3 Cells

Discoidin Domain Receptors (DDR1/DDR2) are tyrosine kinase receptors which are activated by collagen. DDR signalling regulates cell migration, proliferation, apoptosis and matrix metalloproteinase (MMP) production. MMPs degrade extracellular matrix (ECM) and play essential role in tumor growth, invasion and metastasis. Nitrogen-containing bisphosphonates (N-BPs) which strongly inhibit osteoclastic activity are commonly used for osteoporosis treatment. They also have MMP inhibitory effect. In this study, we aimed to investigate the effects of zoledronate in PC3 cells and the possible role of DDR signalling and downstream pathways in these inhibitory effects.

We studied messenger RNA (mRNA) and protein expressions of MMP-2,-9,-8, DDR1/DDR2 type I procollagen (TIP) and mRNA levels of PCA-1, MMP-13 and DDR-initiated signalling pathway players including K-Ras oncogene, ERK1, JNK1, p38, AKT-1 and BCLX in PC3 cells in the presence or absence of zoledronate (10-100 μM) for 2-3 days.

Zoledronate (100 μM) down-regulated DDR1/ DDR2, TIP mRNAs but did not change MMP-13 (collagenase-3) mRNA. However, zoledronate up-regulated MMP-8 (collagenase-2) mRNA. Zoledronate also inhibited mRNA expressions of K-Ras, ERK1, AKT-1, BCLX and PCA-1; but did not change JNK1, p38 mRNA levels. Zoledronate (100 μM) supressed DDR1/DDR2, TIP expressions; and gelatinase (MMP-2/MMP-9) expressions/activities. Conversely, zoledronate up-regulated MMP-8 expression in PC3 cells.

Zoledronate down-regulates MMP-2/-9 expressions in PC3 prostate cancer cells. DDR1/DDR2 signalling and DDR-initiated downstream Ras/Raf/ERK and PI3K/AKT pathways may at least partially responsible for MMP inhibitory effect of zoledronate.

Alteration of mevalonate pathway in proliferated vascular smooth muscle from diabetic mice: possible role in high-glucose-induced atherogenic process

The proliferation of vascular smooth muscle cells (VSMCs) is one of the main features of atherosclerosis induced by high glucose. Mevalonate pathway is an important metabolic pathway that plays a key role in multiple cellular processes. The aim of this study was to define whether the enzyme expression in mevalonate pathway is changed in proliferated VSMCs during atherogenic process in diabetic mice. Diabetes was induced in BALB/c mice with streptozotocin (STZ, 50 mg/kg/day for 5 days). Induction of diabetes with STZ was associated with an increase of lesion area and media thickness after 8 and 16 weeks of diabetes. In aorta, there were overexpressions of some enzymes, including 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR), farnesyl pyrophosphate synthase (FPPS), geranylgeranyl pyrophosphate synthase (GGPPS), farnesyltransferase (FNT), and geranylgeranyltransferase-1 (GGT-1), and unchanged expression of squalene synthase (SQS) and phosphor-3-hydroxy-3-methylglutaryl-coenzyme A reductase (P-HMGR) in 8 and 16 weeks of diabetes. In vitro, VSMCs were cultured and treated with different glucose concentrations for 48 h. High glucose (22.2 mM) induced VSMC proliferation and upregulation of HMGR, FPPS, GGPPS, FNT, and GGT-1 but did not change the expressions of SQS and P-HMGR. In conclusion, altered expression of several key enzymes in the mevalonate pathway may play a potential pathophysiological role in atherogenic process of diabetes macrovascular complication.

Effects of intravenous zoledronate and ibandronate on carotid intima-media thickness, lipids and FGF-23 in postmenopausal osteoporotic women

OBJECTIVE

Osteoporosis and atherosclerosis are interconnected entities and share also some pathophysiological mechanisms. Moreover, recent literature data have supported the hypothesis that bisphosphonates (BPs) may have some antiatherogenic actions. This study aimed to evaluate the effects of one year with zoledronate or ibandronate given intravenously on lipid profile and on carotid artery intima-media thickness (CA-IMT).

METHODS

Sixty postmenopausal osteoporotic women (mean age: 66.6±7.8years) were randomly assigned to 1-year treatment with zoledronate 5mg i.v. annually or ibandronate 3mg i.v. every 3 months. In all patients at baseline and after 12months we measured CA-IMT, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), 25-hydroxyvitamin D (25OHD), bone alkaline phosphatase (B-ALP), type I collagen β carboxy telopeptide (βCTX), osteocalcin (OC), fibroblast growth factor 23 (FGF-23) and sclerostin.

RESULTS

The osteoporotic women treated with zoledronate showed a greater reduction in CA-IMT than those treated with ibandronate. HDL-C and HDL-C/LDL-C ratio showed a significant (p<0.01) increase in the 2 groups, whereas, LDL-C showed a reduction in the two groups which, however, reached statistical significance (p<0.05) only in the zoledronate group. FGF-23 serum levels showed a similar and significant decrease in both the women treated with zoledronate and in those treated with ibandronate. At the end of the study period sclerostin serum levels showed a higher increase in the patients treated with zoledronate than in those treated with ibandronate.

CONCLUSION

In osteoporotic women both zoledronate and ibandronate given intravenously resulted in an increase in HDL-C/LDL-C ratio and a reduction of CA-IMT which was significant only for zoledronate. Further prospective studies are needed to clarify whether the change in FGF-23 and sclerostin levels is a marker or a potential mechanism of the action of BPs at a vascular level.

In vitro effects of bisphosphonates on chemotaxis, phagocytosis, and oxidative burst of neutrophil granulocytes

OBJECTIVES

Bisphosphonate-associated osteonecrosis of the jaws is a serious side effect that mainly occurs in patients receiving highly potent, nitrogen-containing bisphosphonates. Usually the diagnosis is made due to exposed bone and a nonhealing wound. Neutrophil granulocytes are essential for sufficient wound healing; therefore, the influence of different bisphosphonates on neutrophil granulocytes was the focus of this study.

MATERIAL AND METHODS

The effect of nitrogen-containing bisphosphonates (ibandronate, pamidronate, and zoledronate) and one non-nitrogen-containing bisphosphonate (clodronate) on chemotaxis, phagocytosis, and oxidative burst of neutrophil granulocytes in human whole blood was analyzed using standard cytometric flow assays.

RESULTS

Chemotaxis of neutrophils was reduced by almost 50 % when cells were treated with ibandronate and zoledronate. All tested nitrogen-containing bisphosphonates moderately increased the percentage of phagocytizing neutrophils, whereas the percentage of oxidizing cells was extremely affected. Zoledronate increased the oxidative burst activity even at low concentrations. Treatment with ibandronate and pamidronate reached the same level, but only in at least 10 times the higher concentrations. The maximal burst activity of a single cell reached nearly 150 % compared to control. In this case, zoledronate also caused maximal effects even at low concentrations. Clodronate did not show any effects.

CONCLUSION

The results show a proinflammatory effect of the nitrogen-containing effect on neutrophil granulocytes which might contribute to the development of osteonecrosis.

CLINICAL RELEVANCE

The altered neutrophil defense might play a key role in the pathogenesis of bisphosphonate-associated osteonecrosis of the jaws, although the underlying causation between inflammatory reaction and the development of necrosis is yet unknown.

Zoledronic acid inhibits pulmonary metastasis dissemination in a preclinical model of Ewing's sarcoma via inhibition of cell migration

Background

Ewing’s sarcoma (ES) is the second most frequent primitive malignant bone tumor in adolescents with a very poor prognosis for high risk patients, mainly when lung metastases are detected (overall survival <15% at 5 years). Zoledronic acid (ZA) is a potent inhibitor of bone resorption which induces osteoclast apoptosis. Our previous studies showed a strong therapeutic potential of ZA as it inhibits ES cell growth in vitro and ES primary tumor growth in vivo in a mouse model developed in bone site. However, no data are available on lung metastasis. Therefore, the aim of this study was to determine the effect of ZA on ES cell invasion and metastatic properties.

Methods

Invasion assays were performed in vitro in Boyden’s chambers covered with Matrigel. Matrix Metalloproteinase (MMP) activity was analyzed by zymography in ES cell culture supernatant. In vivo, a relevant model of spontaneous lung metastases which disseminate from primary ES tumor was induced by the orthotopic injection of 10⁶ human ES cells in the tibia medullar cavity of nude mice. The effect of ZA (50 μg/kg, 3x/week) was studied over a 4-week period. Lung metastases were observed macroscopically at autopsy and analysed by histology.

Results

ZA induced a strong inhibition of ES cell invasion, probably due to down regulation of MMP-2 and −9 activities as analyzed by zymography. In vivo, ZA inhibits the dissemination of spontaneous lung metastases from a primary ES tumor but had no effect on the growth of established lung metastases.

Conclusion

These results suggest that ZA could be used early in the treatment of ES to inhibit bone tumor growth but also to prevent the early metastatic events to the lungs.

Heart failure in patients treated with bisphosphonates

OBJECTIVES

The aim of this study was to investigate the occurrence of heart failure in patients treated with bisphosphonates.

DESIGN

In this nationwide retrospective cohort study from Denmark, all users of bisphosphonates and raloxifene between 1996 and 2006 (n = 102 342) were included in the 'exposed' group and three age- and gender-matched subjects (n = 307.026) from the general population comprised the control group. The risk of heart failure was estimated by Cox proportional hazard analyses.

RESULTS

The mean follow-up times were 2.8, 5.5 and 4.9 years for alendronate-, etidronate- and raloxifene-treated patients, respectively. The absolute risk of heart failure was 4.4% in the exposed group and 3.7% in the control group (P < 0.01). The relative risk (RR) of heart failure was significantly increased in users of bisphophonates: crude RR 1.71 [95% confidence interval (CI) 1.63-1.79]; adjusted hazard ratio (HR) 1.41 (95% CI 1.34-1.48). By comparison, raloxifene, which is used for the same indication but has a different mechanism of action, was not associated with an increased risk of heart failure: adjusted HR 1.07 (95% CI 0.76-1.50). When the two most commonly used bisphosphonates, alendronate and etidronate, were analysed separately, significant trends in the risk of heart failure were observed across refill compliance strata. The risk of heart failure increased significantly with increasing refill compliance for etidronate (P for trend < 0.01), whereas it decreased for alendronate (P for trend < 0.01).

CONCLUSIONS

Bisphosphonate users were at increased risk of heart failure compared to age- and gender-matched control subjects. However, users of alendronate showed a dose-dependent reduction in this risk, suggesting that alendronate may reduce the risk of heart failure.

Differential effect of zoledronic acid on human vascular smooth muscle cells

INTRODUCTION

The activation of human vascular smooth muscle cell proliferation, adhesion and migration is essential for intimal hyperplasia formation. These experiments were designed to test whether zoledronic acid (ZA) would modulate indices of human smooth muscle cell activation, exert differential effects on proliferating versus quiescent cells, and determine whether these effects were dependent on GTPase binding proteins prenylation. ZA was chosen for testing in these experiments because it is clinically used in humans with cancer, and has been shown to modulate rat smooth muscle cell proliferation and migration.

METHODS

Human aortic smooth muscle cells (HASMC) were cultured under either proliferating or growth arrest (quiescent) conditions in the presence or absence of ZA for 48 hours, whereupon the effect of ZA on HASMC proliferation, cellular viability, metabolic activity, and membrane integrity were compared. In addition, the effect of ZA on adhesion and migration were assessed in proliferating cells. The effect of increased concentration of ZA on the mevalonate pathway and genomic/cellular stress related poly-adenosine diphosphate ribose polymerase enzyme activity were assessed using the relative prenylation of Rap-1A/B protein and the formation of poly adenosine diphosphate-ribosylated protein, respectively.

RESULTS

There was a dose dependent inhibition of cellular proliferation, adhesion and migration following ZA treatment. ZA treatment decreased indices of cellular viability and significantly increased membrane injury in proliferating versus quiescent cells. This was correlated with the appearance of unprenylated Rap-1A protein and dose dependent down regulation of activity.

CONCLUSIONS

These data suggest that ZA is effective in inhibiting HASMC proliferation, adhesion, and migration, which coincide with the appearance of unprenylated RAP-1A/B protein, thereby suggesting that the mevalonate pathway may play a role in the inhibition of HASMC activation.

A population-based 2-year follow-up study on the relationship between bisphosphonates and the risk of stroke

This study aimed to explore the effect of bisphosphonate treatment on stroke using a large population cohort study. We found that the patients who received bisphosphonate therapy were less likely to suffer a stroke than comparison patients (hazard ratio (HR) = 0.79; 95% confidence interval (CI) = 0.66-0.99; p = 0.005) during a 2-year follow-up period.

INTRODUCTION

Animal models have suggested that bisphosphonates have a beneficial effect on the cardiovascular system. However, data on this topic in human subjects are still lacking. This study aimed to explore the protective effect of bisphosphonate treatment on stroke using a large population cohort study.

METHODS

We identified 2,148 patients who received bisphosphonate therapy for osteoporotic fractures. We randomly extracted 6,444 subjects with vertebral or hip fractures as a comparison group matched with the study group on age, sex, and year of index date. Each patient was individually tracked for 2 years to identify those who suffered a stroke. Stratified Cox proportional hazards regressions were performed to assess the effect of bisphosphonate treatment on the risk of stroke.

RESULTS

We found that 184 (8.6%) patients who received bisphosphonate therapy and 696 (10.8%) comparison patients suffered a stroke during the follow-up period. After adjusting for demographic variables and medical co-morbidities, stratified Cox proportional hazards regressions stratified by propensity score revealed that patients who received bisphosphonate therapy were less likely to suffer a stroke than comparison patients (HR = 0.79; 95% CI = 0.66-0.99). The adjusted HR for subarachnoid/intra-cerebral hemorrhage for patients who received bisphosphonate therapy was only 0.53 times (95% CI = 0.33-0.92) that of comparison patients, and the hazard of having an ischemic stroke during the 2-year follow-up period was 0.81 times that of comparison patients (95% CI = 0.65-0.96).

CONCLUSION

Patients who received bisphosphonate therapy were associated with a lower risk of stroke during a 2-year follow-up period.

Gleditsia sinensis thorn extract inhibits proliferation and TNF-α-induced MMP-9 expression in vascular smooth muscle cells

The thorns of Gleditsia sinensis, which are extensively used as a medicinal herb in Asian countries, have been reported to exert various pharmacological effects. However, the anti-atherogenic effect of Gleditsia sinensis thorns has never been investigated. In the present study, we investigated the role and effect of the ethanol extract of Gleditsia sinensis thorns (EEGS) on cultured vascular smooth muscle cells (VSMC). Treatment of VSMC with EEGS led to a significant decrease in cell growth by arresting cells in the G2/M-phase of the cell cycle, which was associated with up-regulated p21WAF1 levels and suppression of G2/M cell cycle regulators, cyclinB1, Cdc2 and Cdc25c. In addition, EEGS treatment led to the induction of extracellular signal-regulated kinase1/2 (ERK1/2), p38 MAPK, and JNK (c-Jun N-terminal kinases) activation. EEGS-induced p21WAF1 expression was blocked by treatment with the p38 MAPK-specific inhibitor SB203580. SB203580 also markedly recovered the inhibition of cell growth and decrease in cell cycle proteins in EEGS-treated VSMC. Moreover, EEGS inhibited matrix metalloproteinase-9 (MMP-9) expression induced by tumor necrosis factor-α (TNF-α) in VSMC. Finally, an electrophoresis mobility shift assay demonstrated that EEGS suppressed expression of transcription factor, nuclear factor kappaB (NF-κB) and activator protein-1 (AP-1), which are essential cis-elements for the MMP-9 promoter in TNF-α-treated VSMC. These results demonstrate that EEGS exerts a potent inhibitory effect on cell proliferation and MMP-9 expression in VSMC. These unexpected novel findings represent theoretical data for the preventive and therapeutic use of EEGS for the treatment of atherosclerosis disease.

Liposome technology for cardiovascular disease treatment and diagnosis

INTRODUCTION

Over the past several decades, liposomes have been used in a variety of applications, from delivery vehicles to cell membrane models. In terms of pharmaceutical use, they can offer control over the release of active agents encapsulated into their lipid bilayer or aqueous core, while providing protection from degradation in the body. In addition, liposomes are versatile carriers, because targeting moieties can be conjugated on the surface to enhance delivery efficiency. It is for these reasons that liposomes have been applied as carriers for a multitude of drugs and genetic material, and as contrast agents, aimed to treat and diagnose cardiovascular diseases.

AREAS COVERED

This review details advancements in liposome technology used in the field of cardiovascular medicine. In particular, the application of liposomes to cardiovascular disease treatment and diagnosis, with a focus on delivering drugs, genetic material and improving cardiovascular imaging, will be explored. Advances in targeting liposomes to the vasculature will also be detailed.

EXPERT OPINION

Liposomes may provide the means to deliver drugs and other pharmaceutical agents for cardiovascular applications; however, there is still a vast amount of research and clinical trials that must be performed before a formulation is brought to market. Advancements in targeting abilities within the body, as well as the introduction of theranostic liposomes, capable of both delivering treating and imaging cardiac diseases, may be expected in the future of this burgeoning field.

Zoledronate inhibits intimal hyperplasia in balloon-injured rat carotid artery

BACKGROUND AND OBJECTIVE

Zoledronate has been reported to inhibit the proliferation, adhesion and migration of vascular smooth muscle cells. In the present study, we assessed whether systemic and local delivery of zoledronate would be sufficient to prevent intimal hyperplasia.

METHODS

Twenty-four male Sprague-Dawley rats were assigned into four groups: non-treated group, systemic zoledronate-treated group, local collagen-treated group and local zoledronate-treated group. All four groups underwent balloon injury to the right common carotid artery. The left uninjured carotid arteries of the non-treated group were considered as normal artery samples. Twenty-one days after arterial injury and treatment, the right and left common carotid arteries were fixed, sectioned, stained and measured by computer-aided image analysis.

RESULTS

At 3 weeks, there was a 59% reduction of the intima/media area ratio in the systemic zoledronate-treated group compared with the non-treated group (P < 0.01). There was an 87% reduction of the intima/media area ratio in the local zoledronate-treated group compared with the local collagen-treated group (P < 0.01).

CONCLUSIONS

Both systemic and local delivery of zoledronate correspond to a significant reduction in intimal hyperplasia seen at 3 weeks.