Computational approaches for drug repurposing in oncology: untapped opportunity for high value innovation.

Historically, the effort by academia and industry to develop new chemical entities into lifesaving drugs has limited success in meeting the demands of today's healthcare. Repurposing drugs that are originally approved by the United States Food and Drug Administration or by regulatory authorities around the globe is an attractive strategy to rapidly develop much-needed therapeutics for oncologic indications that extend from treating cancer to managing treatment-related complications. This review discusses computational approaches to harness existing drugs for new therapeutic use in oncology.

Combination of esomeprazole and pirfenidone enhances antifibrotic efficacy in vitro and in a mouse model of TGFß-induced lung fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease of unknown etiology. Currently, pirfenidone and nintedanib are the only FDA-approved drugs for the treatment of IPF and are now the standard of care. This is a significant step in slowing down the progression of the disease. However, the drugs are unable to stop or reverse established fibrosis. Several retrospective clinical studies indicate that proton pump inhibitors (PPIs; FDA-approved to treat gastroesophageal reflux) are associated with favorable outcomes in patients with IPF, and emerging preclinical studies report that PPIs possess antifibrotic activity. In this study, we evaluated the antifibrotic efficacy of the PPI esomeprazole when combined with pirfenidone in vitro and in vivo. In cell culture studies of IPF lung fibroblasts, we assessed the effect of the combination on several fibrosis-related biological processes including TGFß-induced cell proliferation, cell migration, cell contraction, and collagen production. In an in vivo study, we used mouse model of TGFß-induced lung fibrosis to evaluate the antifibrotic efficacy of esomeprazole/pirfenidone combination. We also performed computational studies to understand the molecular mechanisms by which esomeprazole and/or pirfenidone regulate lung fibrosis. We found that esomeprazole significantly enhanced the anti-proliferative effect of pirfenidone and favorably modulated TGFß-induced cell migration and contraction of collagen gels. We also found that the combination significantly suppressed collagen production in response to TGFß in comparison to pirfenidone monotherapy. In addition, our animal study demonstrated that the combination therapy effectively inhibited the differentiation of lung fibroblasts into alpha smooth muscle actin (αSMA)-expressing myofibroblasts to attenuate the progression of lung fibrosis. Finally, our bioinformatics study of cells treated with esomeprazole or pirfenidone revealed that the drugs target several extracellular matrix (ECM) related pathways with esomeprazole preferentially targeting collagen family members while pirfenidone targets the keratins. In conclusion, our cell biological, computational, and in vivo studies show that the PPI esomeprazole enhances the antifibrotic efficacy of pirfenidone through complementary molecular mechanisms. This data supports the initiation of prospective clinical studies aimed at repurposing PPIs for the treatment of IPF and other fibrotic lung diseases where pirfenidone is prescribed.

Proton pump inhibitors and sensitization of cancer cells to radiation therapy.

This review article outlines six molecular pathways that confer resistance of cancer cells to ionizing radiation, and describes how proton pump inhibitors (PPIs) may be used to overcome radioresistance induced by alteration of one or more of these signaling pathways. The inflammatory, adaptive, hypoxia, DNA damage repair, cell adhesion, and developmental pathways have all been linked to the resistance of cancer cells to ionizing radiation. Here we describe the molecular link between alteration of these pathways in cancer cells and development of resistance to ionizing radiation, and discuss emerging data on the use of PPIs to favorably modify one or more components of these pathways to sensitize cancer cells to ionizing radiation. Understanding the relationship between altered signaling pathways, radioresistance, and biological activity of PPIs may serve as a basis to repurpose PPIs to restore key biological processes that are involved in cancer progression and to sensitize cancer cells to radiation therapy.

Esomeprazole covalently interacts with the cardiovascular enzyme dimethylarginine dimethylaminohydrolase: Insights into the cardiovascular risk of proton pump inhibitors.

BACKGROUND: Proton pump inhibitors (PPIs) are widely prescribed drugs for the treatment of gastroesophageal reflux disease (GERD). Several meta-analysis studies have reported associations between prolonged use of PPIs and major adverse cardiovascular events. However, interaction of PPIs with biological molecules involved in cardiovascular health is incompletely characterized. Dimethylarginine dimethylaminohydrolase (DDAH) is a cardiovascular enzyme expressed in cardiomyocytes, and other somatic cell types in one of two isotypes (DDAH1 and DDAH2) to metabolize asymmetric dimethylarginine (ADMA); a cardiovascular risk factor and competitive inhibitor of nitric oxide synthases (NOSs). METHODS: We performed high throughput drug screening of over 130,000 small molecules to discover human DDAH1 inhibitors and found that PPIs directly inhibit DDAH1. We expressed and purified the enzyme for structural and mass spectrometry proteomics studies to understand how a prototype PPI, esomeprazole, interacts with DDAH1. We also performed molecular docking studies to model the interaction of DDAH1 with esomeprazole. X-ray crystallography was used to determine the structure of DDAH1 alone and bound to esomeprazole at resolutions ranging from 1.6 to 2.9 Å. RESULTS: Analysis of the enzyme active site shows that esomeprazole interacts with the active site cysteine (Cys273) of DDAH1. The structural studies were corroborated by mass spectrometry which indicated that cysteine was targeted by esomeprazole to inactivate DDAH1. CONCLUSIONS: The inhibition of this important cardiovascular enzyme by a PPI may help explain the reported association of PPI use and increased cardiovascular risk in patients and the general population. GENERAL SIGNIFICANCE: Our study calls for pharmacovigilance studies to monitor adverse cardiovascular events in chronic PPI users.

Inhibition of RUNX1 blocks the differentiation of lung fibroblasts to myofibroblasts.

Pathological fibrosis contributes to progression of various diseases, for which the therapeutic options are limited. Idiopathic pulmonary fibrosis (IPF) is one such progressive and fatal interstitial fibrotic disease that is often characterized by excessive accumulation of extracellular matrix (ECM) proteins leading to stiff lung tissue and impaired gas exchange. However, the molecular mechanisms underlying IPF progression remain largely unknown. In this study, we determined the role of Runt-related transcription factor 1 (RUNX1), an evolutionarily conserved transcription factor, in the differentiation of human lung fibroblasts (HLFs) in vitro and in an animal model of bleomycin (BLM)-induced lung fibrosis. We observed that the expression of RUNX1 was significantly increased in the lungs of BLM-injected mice as compared to saline-treated mice. Furthermore, HLFs stimulated with transforming growth factor ß (TGF-ß) showed significantly higher RUNX1 expression at both mRNA and protein levels, and compartmentalization in the nucleus. Inhibition of RUNX1 in HLFs (using siRNA) showed a significant reduction in the differentiation of fibroblasts into myofibroblasts as evidenced by reduced expression of alpha-smooth muscle actin (α-SMA), TGF-ß and ECM proteins such as fibronectin 1 (FN1), and collagen 1A1 (COL1A1). Mechanistic studies revealed that the increased expression of RUNX1 in TGF-ß-stimulated lung fibroblasts is due to enhanced mRNA stability of RUNX1 through selective interaction with the RNA-binding profibrotic protein, human antigen R (HuR). Collectively, our data demonstrate that increased expression of RUNX1 augments processes involved in lung fibrosis including the differentiation of fibroblasts into collagen-synthesizing myofibroblasts. Our study suggests that targeting RUNX1 could limit the progression of organ fibrosis in diseases characterized by abnormal collagen deposition.

Esomeprazole enhances the effect of ionizing radiation to improve tumor control.

The resistance of cancer cells to radiation-based treatment is a major clinical challenge confounding standard of care in cancer. This problem is particularly notable in many solid tumors where cancer cells are only partially responsive to radiation therapy. Combination of radiation with radiosensitizers is able to enhance tumor cell killing. However, currently available radiosensitizers are associated with significant normal tissue toxicity. Accordingly, there is an unmet need to develop safer and more effective radiosensitizers to improve tumor control. Here, we evaluated the radiosensitizing effect of the FDA-approved drug esomeprazole in normal and radioresistant human head and neck squamous cell carcinoma (HNSCC) cells in vitro, and in a mouse model of HNSCC. For the in vitro studies, we used cancer cell colony formation (clonogenicity) assay to compare cancer cell growth in the absence or presence of esomeprazole. To determine mechanism(s) of action, we assessed cell proliferation and profiled cell cycle regulatory proteins. In addition, we performed reverse phase protein array (RPPA) study to understand the global effect of esomeprazole on over 200 cancer-related proteins. For the in vivo study, we engrafted HNSCC in a mouse model and compared tumor growth in animals treated with radiation, esomeprazole, and combination of radiation with esomeprazole. We found that esomeprazole inhibits tumor growth and dose-dependently enhances the cell killing effect of ionizing radiation in wildtype and p53-mutant radioresistant cancer cells. Mechanistic studies demonstrate that esomeprazole arrests cancer cells in the G1 phase of the cell cycle through upregulation of p21 protein and inhibition of cyclin-dependent kinases (Cdks) type 1 (Cdk1) and type 2 (Cdk2). In vivo data showed greater tumor control in animals treated with combination of radiation and esomeprazole compared to either treatment alone, and that this was associated with inhibition of cell proliferation in vivo. In addition, combination of esomeprazole with radiation significantly impaired repair following radiation-induced DNA damage. Our studies indicate that esomeprazole sensitizes cancer cells to ionizing radiation, and is associated with upregulation of p21 to arrest cells in the G1 phase of the cell cycle. Our findings have significant therapeutic implications for the repurposing of esomeprazole as a radiosensitizer in HNSCC and other solid tumors.

Esomeprazole attenuates inflammatory and fibrotic response in lung cells through the MAPK/Nrf2/HO1 pathway.

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is an orphan disease characterized by progressive loss of lung function resulting in shortness of breath and often death within 3-4 years of diagnosis. Repetitive lung injury in susceptible individuals is believed to promote chronic oxidative stress, inflammation, and uncontrolled collagen deposition. Several preclinical and retrospective clinical studies in IPF have reported beneficial outcomes associated with the use of proton pump inhibitors (PPIs) such as esomeprazole. Accordingly, we sought to investigate molecular mechanism(s) by which PPIs favorably regulate the disease process. METHODS: We stimulated oxidative stress, pro-inflammatory and profibrotic phenotypes in primary human lung epithelial cells and fibroblasts upon treatment with bleomycin or transforming growth factor ß (TGFß) and assessed the effect of a prototype PPI, esomeprazole, in regulating these processes. RESULTS: Our study shows that esomeprazole controls pro-inflammatory and profibrotic molecules through nuclear translocation of the transcription factor nuclear factor-like 2 (Nrf2) and induction of the cytoprotective molecule heme oxygenase 1 (HO1). Genetic deletion of Nrf2 or pharmacological inhibition of HO1 impaired esomeprazole-mediated regulation of proinflammatory and profibrotic molecules. Additional studies indicate that activation of Mitogen Activated Protein Kinase (MAPK) pathway is involved in the process. Our experimental data was corroborated by bioinformatics studies of an NIH chemical library which hosts gene expression profiles of IPF lung fibroblasts treated with over 20,000 compounds including esomeprazole. Intriguingly, we found 45 genes that are upregulated in IPF but downregulated by esomeprazole. Pathway analysis showed that these genes are enriched for profibrotic processes. Unbiased high throughput RNA-seq study supported antifibrotic effect of esomeprazole and revealed several novel targets. CONCLUSIONS: Taken together, PPIs may play antifibrotic role in IPF through direct regulation of the MAPK/Nrf2/HO1 pathway to favorably influence the disease process in IPF.

Topical Esomeprazole Mitigates Radiation-Induced Dermal Inflammation and Fibrosis.

Radiation therapy is a mainstream strategy in the treatment of several cancer types that are surgically unresectable. Unfortunately, cancer patients often suffer from unintended consequences of radiotherapy, including the development of skin inflammation (dermatitis), which may progress to fibrosis. These morbid complications often require interruption of radiotherapy and threaten the relapse of underlying cancer. Current treatment options for radiation dermatitis are suboptimal and compel the need to develop safer, more effective therapies. In this study, we assessed the biophysical properties of topically-formulated esomeprazole (here referred to as dermaprazole) and performed proof-of-concept studies to evaluate its efficacy in vitro and in vivo. We found that dermaprazole induced nuclear translocation of erythroid 2-related factor 2 (Nrf2) and significantly upregulated heme oxygenase 1 (HO1) gene and protein expression in a 3D human skin model. Our animal study demonstrated that dermaprazole improved macroscopic appearance of the irradiated skin and accelerated healing of the wounds. Histopathology data corroborated the photographic evidence and confirmed that both prophylactically and therapeutically administered dermaprazole conferred potent anti-inflammatory and antifibrotic effects. Gene expression data showed that dermaprazole downregulated several pro-oxidant, pro-inflammatory and profibrotic genes. In conclusion, topical formulation of the FDA-approved drug esomeprazole is highly effective in attenuating dermal inflammation and fibrosis.

Radiation-Induced Lung Injury: Assessment and Management.

Radiation-induced lung injury (RILI) encompasses any lung toxicity induced by radiation therapy (RT) and manifests acutely as radiation pneumonitis and chronically as radiation pulmonary fibrosis. Because most patients with thoracic and breast malignancies are expected to undergo RT in their lifetime, many with curative intent, the population at risk is significant. Furthermore, indications for thoracic RT are expanding given the advent of stereotactic body radiation therapy (SBRT) or stereotactic ablative radiotherapy (SABR) for early-stage lung cancer in nonsurgical candidates as well as oligometastatic pulmonary disease from any solid tumor. Fortunately, the incidence of serious pulmonary complications from RT has decreased secondary to advances in radiation delivery techniques. Understanding the temporal relationship between RT and injury as well as the patient, disease, and radiation factors that help distinguish RILI from other etiologies is necessary to prevent misdiagnosis. Although treatment of acute pneumonitis is dependent on clinical severity and typically responds completely to corticosteroids, accurately diagnosing and identifying patients who may progress to fibrosis is challenging. Current research advances include high-precision radiation techniques, an improved understanding of the molecular basis of RILI, the development of small and large animal models, and the identification of candidate drugs for prevention and treatment.

Nicotine Modulates Growth Factors and MicroRNA to Promote Inflammatory and Fibrotic Processes.

Idiopathic pulmonary fibrosis (IPF) is a fatal disease that destroys the structure and function of the lungs. Risk factors include advanced age and genetic predisposition. However, tobacco use is the chief modifiable risk factor. The prevalence of tobacco use in IPF reaches up to 80%. Although tobacco smoke contains over 5000 chemicals, nicotine is a major component. Nicotine is a bioactive molecule that acts upon nicotinic acetylcholine receptors expressed on neuronal and non-neuronal cells including endothelial cells. Accordingly, it has a pleiotropic effect on cell proliferation and angiogenesis. The angiogenic effect is partly mediated by stimulation of growth factors including fibroblast, platelet-derived, and vascular endothelial growth factors. Nintedanib, a Food and Drug Administration-approved drug for IPF, works by inhibiting receptors for these growth factors, suggesting a pathobiologic role of the growth factors in IPF and a potential mechanism by which tobacco use may exacerbate the disease process; additionally, nicotine downregulates anti-inflammatory microRNAs (miRs) in lung cells. Here, we profiled the expression of miRs in lung tissues explanted from a lung injury model and examined the effect of nicotine on one of the identified miRs (miR-24) and its downstream targets. Our data show that miR-24 is downregulated during lung injury and is suppressed by nicotine. We also found that nicotine upregulates the expression of inflammatory cytokines targeted by miR-24. Finally, nicotine stimulated growth factors, fibroblast proliferation, collagen release, and expression of myofibroblast markers. Taken together, nicotine, alone or as a component of tobacco smoke, may accelerate the disease process in IPF through stimulation of growth factors and downregulation of anti-inflammatory miRs.

Anticancer therapy and lung injury: molecular mechanisms.

INTRODUCTION: Chemotherapy and radiation therapy are two mainstream strategies applied in the treatment of cancer that is not operable. Patients with hematological or solid tumor malignancies substantially benefit from chemotherapeutic drugs and/or ionizing radiation delivered to the site of malignancy. However, considerable adverse effects, including lung inflammation and fibrosis, are associated with the use of these treatment modalities. Areas covered: As we move toward the era of precision health, we are compelled to understand the molecular basis of chemoradiation-induced pathological lung remodeling and to develop effective treatment strategies that mitigate the development of chronic lung disease (i.e. fibrosis) in cancer patients. The review discusses chemotherapeutic agents that are reported to induce or associate with acute and/or chronic lung injury. Expert commentary: There is a need to molecularly understand how chemotherapeutic drugs induce or associate with respiratory toxicities and whether such characteristics are inherently related to their antitumor effect or are collateral. Once such mechanisms have been identified and/or fully characterized, they may be able to guide disease-management decisions including effective intervention strategies for the adverse effects. In the meantime, radiation oncologists should be judicious on the dose of radiation delivered to the lungs, the volume of lung irradiated, and concurrent use of chemotherapeutic drugs.

Proton Pump Inhibitors in IPF: A Call for Clinical Trials.

The recent FDA approval of two drugs, pirfenidone and nintedanib, for the treatment of idiopathic pulmonary fibrosis (IPF) has fueled interest in the development of additional drugs to treat the disease or its major clinical complications including cough and acute exacerbations. Since 2015, there are at least a dozen active interventional studies that are testing the efficacy of novel pharmacotherapies, exercise or stem cells in modifying the disease process in IPF. Additionally, there are combinatorial studies evaluating the effectiveness of pirfenidone or nintedanib in combination with other agents. However, there remains an urgent need for clinical trials to prospectively evaluate the efficacy of existing drugs with promising retrospective data, such as proton pump inhibitors (PPIs), in IPF. Several retrospective cohorts have provided tantalizing data supporting the beneficial effect of PPIs in patients with well-defined IPF. This review provides the general outlook of pharmacotherapies in IPF, and highlights preclinical and retrospective clinical data to make a case for randomized controlled clinical trials of PPIs in IPF.

Silent Neoplastic Cardiac Invasion in Small Cell Lung Cancer: A Case Report and Review of the Literature.

BACKGROUND Secondary malignant tumor of the heart is one of the most life-threatening complications of lung cancer. Several published case reports have documented non-small cell lung cancer (NSCLC) patients with neoplastic cardiac invasion. However, the number of reported cases of small cell lung cancer (SCLC) with neoplastic cardiac invasion is limited. CASE REPORT We present a rare case of advanced SCLC in a patient with asymptomatic neoplastic cardiac invasion. We also discuss radiation therapy modalities that should be considered in SCLC patients with cardiac invasion. CONCLUSIONS Clinicians should be vigilant about cases of SCLC with asymptomatic intra-cardiac invasion and practice caution when diagnosing, as well as treating with radiation as a monotherapy.

Therapeutic Efficacy of Esomeprazole in Cotton Smoke-Induced Lung Injury Model.

Proton pump inhibitors (PPIs) are well-known antacid drugs developed to treat gastric disorders. Emerging studies demonstrate that PPIs possess biological activities that extend beyond inhibition of H+/K+ ATPase (proton pumps) expressed in parietal cells of the stomach. Some of the extra-gastric activities of PPIs include modulation of epithelial, endothelial, and immune cell functions. Recently, we reported that PPIs suppress the expression of several proinflammatory and profibrotic molecules, as well as enhance antioxidant mechanisms in order to favorably regulate lung inflammation and fibrosis in an animal model of bleomycin-induced lung injury. In addition, several retrospective clinical studies report that the use of PPIs is associated with beneficial outcomes in chronic lung diseases including idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD). Based on these preclinical and clinical observations, we hypothesized that PPIs ameliorate smoke-induced lung injury. Accordingly, we evaluated the pharmacological efficacy of the PPI esomeprazole in a mouse model of cotton smoke-induced lung injury. The animals were exposed to cotton smoke for 3-weeks in the presence or absence of esomeprazole treatment. We found that therapeutic administration of esomeprazole significantly inhibited the progression of fibrosis throughout the lungs of the animals in this group compared to controls. In addition, esomeprazole also reduced circulating markers of inflammation and fibrosis. Overall, our work extends the emerging anti-inflammatory and antifibrotic potential of PPIs and their role in modulation of chronic lung diseases.

Proton Pump Inhibitors Accelerate Endothelial Senescence.

RATIONALE: Proton pump inhibitors (PPIs) are popular drugs for gastroesophageal reflux, which are now available for long-term use without medical supervision. Recent reports suggest that PPI use is associated with cardiovascular, renal, and neurological morbidity. OBJECTIVE: To study the long-term effect of PPIs on endothelial dysfunction and senescence and investigate the mechanism involved in PPI-induced vascular dysfunction. METHODS AND RESULTS: Chronic exposure to PPIs impaired endothelial function and accelerated human endothelial senescence by reducing telomere length. CONCLUSIONS: Our data may provide a unifying mechanism for the association of PPI use with increased risk of cardiovascular, renal, and neurological morbidity and mortality.

Optimal ROS Signaling Is Critical for Nuclear Reprogramming.

Efficient nuclear reprogramming of somatic cells to pluripotency requires activation of innate immunity. Because innate immune activation triggers reactive oxygen species (ROS) signaling, we sought to determine whether there was a role of ROS signaling in nuclear reprogramming. We examined ROS production during the reprogramming of doxycycline (dox)-inducible mouse embryonic fibroblasts (MEFs) carrying the Yamanaka factors (Oct4, Sox2, Klf4, and c-Myc [OSKM]) into induced pluripotent stem cells (iPSCs). ROS generation was substantially increased with the onset of reprogramming. Depletion of ROS via antioxidants or Nox inhibitors substantially decreased reprogramming efficiency. Similarly, both knockdown and knockout of p22(phox)-a critical subunit of the Nox (1-4) complex-decreased reprogramming efficiency. However, excessive ROS generation using genetic and pharmacological approaches also impaired reprogramming. Overall, our data indicate that ROS signaling is activated early with nuclear reprogramming, and optimal levels of ROS signaling are essential to induce pluripotency.

Idiopathic Pulmonary Fibrosis: Novel Concepts of Proton Pump Inhibitors as Antifibrotic Drugs.

The prevalence of abnormal acid gastroesophageal reflux (GER) is higher in patients with idiopathic pulmonary fibrosis (IPF) than in matched control subjects. Several studies demonstrated that more than one-third of patients with IPF have abnormal esophageal acid exposures. In addition, many of these studies indicate that the majority of patients with IPF have silent reflux with no symptoms of GER. Findings of abnormal reflux persist in a large proportion of patients with IPF placed on antacid therapy such as proton pump inhibitors (PPIs). This seemingly paradoxical observation suggests that either patients with IPF are somehow resistant to PPI-based intervention or PPIs are inherently unable to suppress acid GER. By contrast, patients with IPF who undergo Nissen fundoplication surgery are effectively relieved from the complications of GER, and retrospective studies suggest improved lung function. Retrospective, anecdotal data suggest a beneficial role of PPIs in IPF including stabilization of lung function, reduction in episodes of acute exacerbation, and enhanced longevity. The recent evidence-based guidelines for treatment of IPF approved conditional recommendation of PPIs for all patients with IPF regardless of their GER status. Recently, we have reported that PPIs possess antiinflammatory and antifibrotic activities by directly suppressing proinflammatory cytokines, profibrotic proteins, and proliferation of lung fibroblasts. Our study provides an alternative explanation for the beneficial effect of PPIs in IPF. In this Perspective, we reviewed emerging progress on antifibrotic effect of PPIs using IPF as a disease model. In addition, we summarized surgical and pharmacological interventions for GER and their downstream effect on lung physiology.

Vascular Aging: Implications for Cardiovascular Disease and Therapy.

The incidence and prevalence of cardiovascular disease is highest among the elderly, in part, due to deleterious effects of advancing age on the heart and blood vessels. Aging, a known cardiovascular risk factor, is progressively associated with structural and functional changes to the vasculature including hemodynamic disturbance due to increased oxidative stress, premature cellular senescence and impairments in synthesis and/or secretion of endothelium-derived vasoactive molecules. These molecular and physiological changes lead to vessel wall stiffening and thickening, as well as other vascular complications that culminate to loss of vascular tone regulation and endothelial function. Intriguingly, the vessel wall, a biochemically active structure composed of collagen, connective tissue, smooth muscle and endothelial cells, is adversely affected by processes involved in premature or normal aging. Notably, the inner most layer of the vessel wall, the endothelium, becomes senescent and dysfunctional with advancing age. As a result, its ability to release vasoactive molecules such as acetylcholine (ACh), prostacyclin (PGI2), endothelium-derived hyperpolarizing factor (EDHF), and nitric oxide (NO) is reduced and the cellular response to these molecules is also impaired. By contrast, the vascular endothelium increases its generation and release of reactive oxygen (ROS) and nitrogen (RNS) species, vasoconstrictors such as endothelin (ET) and angiotensin (AT), and endogenous inhibitors of NO synthases (NOSs) to block NO. This skews the balance of the endothelium in favor of the release of highly tissue reactive and harmful molecules that promote DNA damage, telomere erosion, senescence, as well as stiffened and hardened vessel wall that is prone to the development of hypertension, diabetes, atherosclerosis and other cardiovascular risk factors. This Review discusses the impact of advancing age on cardiovascular health, and highlights the cellular and molecular mechanisms that underlie age-associated vascular changes. In addition, the role of pharmacological interventions in preventing or delaying age-related cardiovascular disease is discussed.