Captopril attenuates hypertension and renal injury induced by the vascular endothelial growth factor inhibitor sorafenib

Identifying mitigating strategies for endothelial cell dysfunction and hypertension in response to VEGF receptor inhibitors

Vascular endothelial growth factor receptor inhibitors (VEGFRis) improve cancer survival but are associated with treatment-limiting hypertension, often attributed to endothelial cell (EC) dysfunction. Using phosphoproteomic profiling of VEGFRi-treated ECs, drugs were screened for mitigators of VEGFRi-induced EC dysfunction and validated in primary aortic ECs, mice, and canine cancer patients. VEGFRi treatment significantly raised systolic blood pressure (SBP) and increased markers of endothelial and renal dysfunction in mice and canine cancer patients. α-Adrenergic-antagonists were identified as drugs that most oppose the VEGFRi proteomic signature. Doxazosin, one such α-antagonist, prevented EC dysfunction in murine, canine, and human aortic ECs. In mice with sorafenib-induced-hypertension, doxazosin mitigated EC dysfunction but not hypertension or glomerular endotheliosis, while lisinopril mitigated hypertension and glomerular endotheliosis without impacting EC function. Hence, reversing EC dysfunction was insufficient to mitigate VEGFRi-induced-hypertension in this mouse model. Canine cancer patients with VEGFRi-induced-hypertension were randomized to doxazosin or lisinopril and both agents significantly decreased SBP. The canine clinical trial supports safety and efficacy of doxazosin and lisinopril as antihypertensives for VEGFRi-induced-hypertension and the potential of trials in canines with spontaneous cancer to accelerate translation. The overall findings demonstrate the utility of phosphoproteomics to identify EC-protective agents to mitigate cardio-oncology side effects.

Understanding Sorafenib-Induced Cardiovascular Toxicity: Mechanisms and Treatment Implications

Tyrosine kinase inhibitors (TKIs) have been recognized as crucial agents for treating various tumors, and one of their key targets is the intracellular site of the vascular endothelial growth factor receptor (VEGFR). While TKIs have demonstrated their effectiveness in solid tumor patients and increased life expectancy, they can also lead to adverse cardiovascular effects including hypertension, thromboembolism, cardiac ischemia, and left ventricular dysfunction. Among the TKIs, sorafenib was the first approved agent and it exerts anti-tumor effects on hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC) by inhibiting angiogenesis and tumor cell proliferation through targeting VEGFR and RAF. Unfortunately, the adverse cardiovascular effects caused by sorafenib not only affect solid tumor patients but also limit its application in curing other diseases. This review explores the mechanisms underlying sorafenib-induced cardiovascular adverse effects, including endothelial dysfunction, mitochondrial dysfunction, endoplasmic reticulum stress, dysregulated autophagy, and ferroptosis. It also discusses potential treatment strategies, such as antioxidants and renin-angiotensin system inhibitors, and highlights the association between sorafenib-induced hypertension and treatment efficacy in cancer patients. Furthermore, emerging research suggests a link between sorafenib-induced glycolysis, drug resistance, and cardiovascular toxicity, necessitating further investigation. Overall, understanding these mechanisms is crucial for optimizing sorafenib therapy and minimizing cardiovascular risks in cancer patients.

Investigation of the Captopril-Insulin Interaction by Mass Spectrometry and Computational Approaches Reveals that Captopril Induces Structural Changes in Insulin

Post-translational modifications remarkably regulate proteins' biological function. Small molecules such as reactive thiols, metabolites, and drugs may covalently modify the proteins and cause structural changes. This study reports the covalent modification and noncovalent interaction of insulin and captopril, an FDA-approved antihypertensive drug, through mass spectrometric and computation-based approaches. Mass spectrometric analysis shows that captopril modifies intact insulin, reduces it into its "A" and "B" chains, and covalently modifies them by forming adducts. Since captopril has a reactive thiol group, it might reduce the insulin dimer or modify it by reacting with cysteine residues. This was proven with dithiothreitol treatment, which reduced the abundance of captopril adducts of insulin A and B chains and intact Insulin. Liquid chromatography tandem mass spectrometric analysis identified the modification of a total of four cysteine residues, two in each of the A and B chains of insulin. These modifications were identified to be Cys6 and Cys7 of the A chain and Cys7 and Cys19 of the B chain. Mass spectrometric analysis indicated that captopril may simultaneously modify the cysteine residues of intact insulin or its subunits A and B chains. Biophysical studies involving light scattering and thioflavin T assay suggested that the binding of captopril to the protein leads to the formation of aggregates. Docking and molecular dynamics studies provided insights into the noncovalent interactions and associated structural changes in insulin. This work is a maiden attempt to understand the detailed molecular interactions between captopril and insulin. These findings suggest that further investigations are required to understand the long-term effect of drugs like captopril.

The hypertensive effect of sorafenib is abolished by sildenafil

Background

Contrasting to the well documented tyrosine kinase inhibitor (TKI)-induced hypertension, little is known on their intrinsic vasomotor effects. We investigated the vasomotor effects of sorafenib, a widely used multikinase inhibitor in the treatment of hepatocellular and renal cell carcinoma and tested the hypothesis that sildenafil, a phosphodiesterase-5 (PDE-5) inhibitor, could represent a pharmacological strategy for the treatment of TKI-induced hypertension.

Methods

Concentration-response curves of sorafenib were constructed in endothelium-intact or denuded precontracted rat aorta, in the presence or absence of several inhibitors. Acute intravenous effects of sorafenib on arterial blood pressure were also investigated in anaesthetized rats. Finally, rats were chronically treated with sorafenib during 4 weeks in the presence and absence of sildenafil.

Results

In endothelium intact aortic ring, sorafenib induced a potent concentration-dependent relaxation of precontracted rat aorta. Removal of the endothelium shifted the concentration-response curve of sorafenib to the right and significantly reduced its maximal effects, demonstrating that sorafenib-induced vasorelaxation is endothelium-dependent and endothelium-independent. Inhibition of the different pathways implicated in the endothelium-dependent and independent vasorelaxation revealed that the endothelium-dependent effects of sorafenib result mainly from the activation of prostaglandin and the nitric oxide (NO) pathways. The endothelium-independent vasodilatory effects of sorafenib may result mainly from the activation of Na/K-ATPase and soluble guanylate cyclase. These vasodilatory effects observed in vitro were confirmed by the decrease in arterial blood pressure observed during acute administrations of sorafenib in anesthetized rats. Finally, and most importantly, we report here for the first time that chronic administration of sorafenib in rats induced an increase in SBP that was abolished by sildenafil.

Conclusion

The multikinase inhibitor sorafenib induced in vitro vasorelaxation of large conductance artery, primary by activating soluble guanylate cyclase. Its chronic administration led to arterial blood hypertension that was counteracted by a PDE-5 inhibitor, sildenafil. Our results suggest that targeting the cGMP pathway including NO signalling might be an interesting pharmacological strategy for the treatment of TKI-induced hypertension.

The protective effect of losartan against sorafenib induced cardiotoxicity: Ex-vivo isolated heart and metabolites profiling studies in rat

Sorafenib, a tyrosine kinase inhibitor that is used in the treatment of hepatocellular and renal cell carcinoma, was reported to induce cardiotoxicity. This study aimed to investigate the potential cardioprotective effect of losartan against sorafenib-induced cardiotoxicity in rat. Sorafenib significantly reduced the left ventricular pressure, heart rate dp/dt max & dp/dt min (indexes of myocardial contractility and relaxation; respectively), and prolonged both the systolic and diastolic periods. Coadminstration of losartan significantly reversed the effects of sorafenib on heart rate, dp/dt max and dp/dt min. In addition, there was a tendency for losartan to reverse sorafenib reduction in left ventricular pressure and perfusion pressure but it did not reach statistical significance. A GC-MS non-targeted based metabolites profiling of rat plasma revealed elevated metaboites, including urea and fatty acids levels, associated with sorafenib induced cardiotoxicity. However, only glycine and lactic acid were statistically significant. Interestingly, losartan co-administration with sorafenib restored these changes, and resulted in a significantly reduced glycine, urea and some fatty acids levels namely; Cis-vaccenic acid, oleic acid, stearic acid and undecanoic acid. In addition, based on histology results, losartan coadminitration almost obviated sorafenib-induced changes in cardiac tissues. The study suggests that losartan has the potential to exert a protective effect against sorafenib-induced cardiotoxicity.

Angiotensin-Converting Enzyme Inhibitor Protects Against Cisplatin Nephrotoxicity by Modulating Kinin B1 Receptor Expression and Aminopeptidase P Activity in Mice

Cisplatin is a highly effective chemotherapeutic agent. However, its use is limited by nephrotoxicity. Enalapril is an angiotensin I-converting enzyme inhibitor used for the treatment of hypertension, mainly through the reduction of angiotensin II formation, but also through the increase of kinins half-life. Kinin B1 receptor is associated with inflammation and migration of immune cells into the injured tissue. We have previously shown that the deletion or blockage of kinin B1 and B2 receptors can attenuate cisplatin nephrotoxicity. In this study, we tested enalapril treatment as a tool to prevent cisplatin nephrotoxicity. Male C57Bl/6 mice were divided into 3 groups: control group; cisplatin (20 mg/kg i.p) group; and enalapril (1.5 mg;kg i.p) + cisplatin group. The animals were treated with a single dose of cisplatin and euthanized after 96 h. Enalapril was able to attenuate cisplatin-induced increase in creatinine and urea, and to reduce tubular injury and upregulation of apoptosis-related genes, as well as inflammatory cytokines in circulation and kidney. The upregulation of B1 receptor was blocked in enalapril + cisplatin group. Carboxypeptidase M expression, which generates B1 receptor agonists, is blunted by cisplatin + enalapril treatment. The activity of aminopeptidase P, a secondary key enzyme able to degrade kinins, is restored by enalapril treatment. These findings were confirmed in mouse renal epithelial tubular cells, in which enalaprilat (5 μM) was capable of decreasing tubular injury and inflammatory markers. We treated mouse renal epithelial tubular cells with cisplatin (100 μM), cisplatin+enalaprilat and cisplatin+enalaprilat+apstatin (10 μM). The results showed that cisplatin alone decreases cell viability, cisplatin plus enalaprilat is able to restore cell viability, and cisplatin plus enalaprilat and apstatin decreases cell viability. In the present study, we demonstrated that enalapril prevents cisplatin nephrotoxicity mainly by preventing the upregulation of B1 receptor and carboxypeptidase M and the increased concentrations of kinin peptides through aminopeptidase activity restoration.

A SORAFENIB INDUCED MODEL OF GLOMERULAR KIDNEY DISEASE

Glomerular injury and proteinuria are important pathophysiological features of chronic kidney disease. In the present study, we provide data on a glomerular injury model that was developed using the cancer chemotherapy drug sorafenib. Sorafenib is a tyrosine kinase inhibitor that acts via the vascular endothelial growth factor (VEGF) signaling pathway and is widely used to treat a variety of cancers. On the other hand, sorafenib causes serious renal side effects in patients including the development of chronic kidney disease. The current study aimed to utilize the nephrotoxic property of sorafenib to develop a rat model for chronic kidney disease. We demonstrate that rats administered sorafenib for 8 weeks along with a high salt diet (8% NaCl enriched) develop hypertension (80mmHg higher systolic blood pressure), proteinuria (75% higher), and 4-fold higher glomerular injury compared to vehicle-treated normal control rat. Sorafenib induced glomerular injury was associated with decreased (20-80% lower) renal mRNA expression of key glomerular structural proteins such as nephrin, podocin, synaptopodin, and podoplanin compared to vehicle-treated normal control rat. Renal cortical endothelial-to-mesenchymal transition (EndoMT) was activated in the sorafenib induced glomerular injury model. In the sorafenib treated rats, the renal EndoMT was evident with 20% lower mRNA expression of an endothelial marker WT-1 and 2 to 3-fold higher expression of mesenchymal markers Col III, FSP-1, α-SMA, and vimentin. In conclusion, we developed a rat pre-clinical chronic kidney disease model that manifest glomerular injury. We further demonstrate that the glomerular injury in this model is associated with decreased renal mRNA expression of key glomerular structural proteins and an activated kidney EndoMT.

Renin-Angiotensin-Aldosterone System Modulates Blood Pressure Response During Vascular Endothelial Growth Factor Receptor Inhibition

Objectives

This study postulated that antihypertensive therapy with renin-angiotensin-aldosterone system (RAAS) inhibition may mitigate vascular endothelial growth factor inhibitor (VEGFi)–mediated increases in blood pressure more effectively than other antihypertensive medications in patients receiving VEGFi therapy.

Background

VEGFi therapy is commonly used in the treatment of cancer. One common side effect of VEGFi therapy is elevated blood pressure. Evidence suggests that the RAAS may be involved in VEGFi-mediated increases in blood pressure.

Methods

This retrospective cohort analysis was performed using a de-identified version of the electronic health record at Vanderbilt University Medical Center in Nashville, Tennessee. Subjects with cancer who were exposed to VEGFi therapy were identified, and blood pressure and medication data were extracted. Changes in mean systolic and diastolic blood pressure in response to VEGFi therapy in patients receiving RAAS inhibitor (RAASi) therapy before VEGFi initiation were compared with changes in mean systolic and diastolic blood pressure in patients not receiving RAASi therapy before VEGFi initiation.

Results

Mean systolic and diastolic blood pressure rose in both groups after VEGFi use; however, patients who had RAASi therapy before VEGFi initiation had a significantly lower increase in systolic blood pressure as compared with patients with no RAASi therapy (2.46 mm Hg [95% confidence interval: 0.7 to 4.2] compared with 4.56 mm Hg [95% confidence interval: 3.5 to 5.6], respectively; p = 0.034).

Conclusions

In a real-world clinical population, RAASi therapy before VEGFi initiation may ameliorate VEGFi-mediated increases in blood pressure. Randomized clinical trials are needed to further our understanding of the role of RAASi therapy in VEGFi-mediated increases in blood pressure.

Captopril alleviates hypertension-induced renal damage, inflammation, and NF-κB activation

Hypertensive renal damage generally occurs during the middle and late stages of hypertension, which is typically characterized by proteinuria and renal inflammation. Captopril, an angiotensin-converting enzyme (ACE) inhibitor, has been widely used for therapy of arterial hypertension and cardiovascular diseases. However, the protective effects of captopril on hypertension-induced organ damage remain elusive. The present study was designed to explore the renoprotective action of captopril in spontaneously hypertensive rats (SHR). The 6-week-old male SHR and age-matched Wistar-Kyoto rats were randomized into long-term captopril-treated (34 mg/kg) and vehicle-treated groups. The results showed that in SHR there was obvious renal injury characterized by the increased levels of urine albumin, total protein, serum creatinine, blood urea nitrogen, renal inflammation manifested by the increased mRNA and protein expression of inflammatory factors including tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and inducible nitric oxide synthase, and enhanced nuclear factor-κB (NF-κB) activation. Captopril treatment could lower blood pressure, improve renal injury, and suppress renal inflammation and NF-κB activation in SHR rats. In conclusion, captopril ameliorates renal injury and inflammation in SHR possibly via inactivation of NF-κB signaling.

Renin angiotensin system deregulation as renal cancer risk factor

For numerous years, the non-cardiovascular role of the renin-angiotensin system (RAS) was underestimated, but recent studies have advanced the understanding of its function in various processes, including carcinogenesis. Numerous evidence comes from preclinical and clinical studies on the use of antihypertensive agents targeting the RAS, including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers. It has been demonstrated that the use of ACEIs can alter the incidence of renal cell carcinoma (RCC) and may have a positive effect by prolonging patient survival. It has an effect on the complex action of ACEI, resulting in decreased angiotensin II (Ang-II) production and altered levels of bradykinin or Ang 1-7. The present review discusses the existing knowledge on the effects of ACE and its inhibitors on RCC cell lines, xenograft models, and patient survival in clinical studies. A brief introduction to molecular pathways aids in understanding the non-cardiovascular effects of RAS inhibitors and enables the conduction of studies on combined cancer treatment with the application of ACEIs. Recent evidence regarding the treatment of hypertension associated with tyrosine kinase inhibitors, one of the most pronounced and common side effects in modern RCC treatment, are also outlined. Captopril, an ACEI, may be used to lower blood pressure in patients, particularly due to its additional renoprotective actions.

Lenvatinib, an oral multi-kinases inhibitor, -associated hypertension: Potential role of vascular endothelial dysfunction

BACKGROUND AND AIMS

Lenvatinib (Lenvima^®), an oral multi-kinase inhibitor, is effective in the treatment of differentiated thyroid carcinomas (DTCs). A severe adverse effect of lenvatinib is hypertension, thus limiting its use as an anti-cancer treatment. Although the pathogenesis of hypertension is generally assumed to involve microvascular bed reduction and an increase in peripheral vascular resistance due to a decrease in nitrogen oxide (NOx) production after vascular endothelial growth factor (VEGF) inhibition, the effects of hypertension on vascular endothelial function in actual patients remain unclear. Here, we examined how lenvatinib affects vascular endothelial function.

METHODS

Ten consecutive DTC patients who did not take any cardiovascular agents were orally administered 24 mg of lenvatinib once daily. Using an EndoPAT2000^® system, we used reactive hyperemia-peripheral arterial tonometry (RH-PAT) and evaluated vascular endothelial function on the basis of the RH-PAT index (RHI). We expressed the results as %RHI, which indicates the change compared with pretreatment levels. Additionally, we measured serum NOx and plasma VEGF concentrations pre- and post-treatment.

RESULTS

All of the patients treated with lenvatinib exhibited significant hypertension; the %RHI levels were significantly decreased the day after treatment with lenvatinib. Furthermore, serum NOx and plasma VEGF concentrations were significantly decreased and increased, respectively, compared with pretreatment levels. These results indicate that hypertension induced by lenvatinib may be caused by a decrease in nitric oxide production, as a result of VEGF inhibition and impaired vascular endothelial function.

CONCLUSIONS

We provide the first demonstration that lenvatinib causes hypertension via vascular endothelial dysfunction in human subjects.

The endothelium as the common denominator in malignant hypertension and thrombotic microangiopathy

The endothelium plays a pivotal role in vascular biology. The endothelium is the primary site of injury in thrombotic microangiopathies including malignant hypertension. Endothelial injury in thrombotic microangiopathies is the result of increased shear stress, toxins, and/or dysregulated complement activation. Endothelial injury can lead to microvascular thrombosis resulting in ischemia and organ dysfunction, the clinical hallmarks of thrombotic microangiopathies. Currently, available therapies target the underlying mechanisms that lead to endothelial injury in these conditions. Ongoing investigations aim at identifying drugs that protect the endothelium.

Our own worst enemy: pharmacologic mechanisms of hypertension

Drug-induced hypertension is often an unrecognized cause of resistant or secondary hypertension. It is defined as hypertension resulting from the unintended effect of a drug or from a drug's antagonistic effect on antihypertensive medications. The main mechanisms of drug-induced hypertension, when categorized broadly, include volume retention and sympathomimetic effects. These mechanisms along with management strategies will be further discussed in this article.

The contribution of VEGF signalling to fostamatinib-induced blood pressure elevation

BACKGROUND AND PURPOSE

Fostamatinib is an inhibitor of spleen tyrosine kinase (TK). In patients, fostamatinib treatment was associated with increased BP. Some TK inhibitors cause BP elevation, by inhibiting the VEGF receptor 2 (VEGFR2). Here, we have assessed the mechanistic link between fostamatinib-induced BP elevation and inhibition of VEGF signalling.

EXPERIMENTAL APPROACH

We used conscious rats with automated blood sampling and radio telemetry and anaesthetized rats to measure cardiovascular changes. Rat isolated aorta and isolated hearts, and human resistance vessels in vitro were also used. NO production by human microvascular endothelial cells was measured with the NO-dependent probe, DAF-FM and VEGFR2 phosphorylation was determined in mouse lung, ex vivo.

KEY RESULTS

In conscious rats, fostamatinib dose-dependently increased BP. The time course of the BP effect correlated closely with the plasma concentrations of R406 (the active metabolite of fostamatinib). In anaesthetized rats, infusion of R406 increased BP and decreased femoral arterial conductance. Endothelial function was unaffected, as infusion of R406 did not inhibit hyperaemia- or ACh-induced vasodilatation in rats. R406 did not affect contraction of isolated blood vessels. R406 inhibited VEGF-stimulated NO production from human endothelial cells in vitro, and treatment with R406 inhibited VEGFR2 phosphorylation in vivo. R406 inhibited VEGF-induced hypotension in anaesthetized rats.

CONCLUSIONS AND IMPLICATIONS

Increased vascular resistance, secondary to reduced VEGF-induced NO release from endothelium, may contribute to BP increases observed with fostamatanib. This is consistent with the elevated BP induced by other drugs inhibiting VEGF signalling, although the contribution of other mechanisms cannot be excluded.

Incidence and risk of sorafenib-induced hypertension: a systematic review and meta-analysis

Hypertension is one of the major side effects of sorafenib, and reported incidences vary substantially among clinical trials. A systematic review was conducted using Medline, PubMed, Embase, and the Cochrane Library for all longitudinal studies to investigate the incidence and risk of hypertension events in cancer patients treated with sorafenib. A total of 14 randomized controlled trials and 39 prospective single-arm trials involving 13,555 patients were selected for the meta-analysis. The relative risk of all-grade and high-grade hypertension associated with sorafenib were 3.07 (95% confidence interval [CI], 2.05–4.60; P<.01) and 3.31 (95% CI, 2.21–4.95; P<.01), respectively. The overall incidence of sorafenib-induced all-grade and high-grade hypertension were 19.1% (95% CI, 15.8%–22.4%) and 4.3% (95% CI, 3.0%–5.5%), respectively. A significantly higher incidence of hypertension was noted in patients with renal cell carcinoma (RCC) compared with those with non-RCC malignancies (all-grade: 24.9% [95% CI, 19.7%–30.1%] vs 15.7%[95% CI, 12.1%–19.3%]; P<.05; high-grade:8.6% [95% CI, 6.0%–11.2%] vs 1.8% [95% CI, 0.9%–2.6%]; P<.05). The trials with median progression-free survival (PFS) longer than 5.3 months (mean PFS) demonstrated a significantly higher incidence of high-grade hypertension than trials with shorter PFS (6.3% [95% CI, 4.1%–8.5%] vs 2.6% [95% CI, 1.4%– 3.8%]; P<.05). Findings of the meta-analysis indicated a significantly high risk of sorafenib-induced hypertension. Patients with RCC have a significantly higher incidence of hypertension and the occurrence of hypertension may be associated with improved prognosis.

Treatment of hypertension and renal injury induced by the angiogenesis inhibitor sunitinib: preclinical study

Common adverse effects of angiogenesis inhibition are hypertension and renal injury. To determine the most optimal way to prevent these adverse effects and to explore their interdependency, the following drugs were investigated in unrestrained Wistar Kyoto rats exposed to the angiogenesis inhibitor sunitinib: the dual endothelin receptor antagonist macitentan; the calcium channel blocker amlodipine; the angiotensin-converting enzyme inhibitor captopril; and the phosphodiesterase type 5 inhibitor sildenafil. Mean arterial pressure was monitored telemetrically. After 8 days, rats were euthanized and blood samples and kidneys were collected. In addition, 24-hour urine samples were collected. After sunitinib start, mean arterial pressure increased rapidly by ≈30 mm Hg. Coadministration of macitentan or amlodipine largely prevented this rise, whereas captopril or sildenafil did not. Macitentan, captopril, and sildenafil diminished the sunitinib-induced proteinuria and endothelinuria and glomerular intraepithelial protein deposition, whereas amlodipine did not. Changes in proteinuria and endothelinuria were unrelated. We conclude that in our experimental model, dual endothelin receptor antagonism and calcium channel blockade are suitable to prevent angiogenesis inhibition-induced hypertension, whereas dual endothelin receptor antagonism, angiotensin-converting enzyme inhibitor, and phosphodiesterase type 5 inhibition can prevent angiogenesis inhibition-induced proteinuria. Moreover, the variable response of hypertension and renal injury to different antihypertensive agents suggests that these side effects are, at least in part, unrelated.

Hypertension due to antiangiogenic cancer therapy with vascular endothelial growth factor inhibitors: understanding and managing a new syndrome

Novel antiangiogenic cancer therapies, particularly agents that block vascular endothelial growth factor (VEGF) signalling, have improved outcomes in patients with cancers and are now used as first-line therapies for some tumours. However, with VEGF inhibitors (VEGFIs) are new complications, particularly hypertension. VEGFI-induced hypertension is a dose-dependent phenomenon due to on-target effects rather than off-target effects. Increased blood pressure occurs in almost 100% of patients who take VEGFIs, with a subset who develop severe hypertension. Molecular mechanisms underlying VEGFI-induced hypertension are unclear, but endothelial dysfunction and increased vascular resistance, due to impaired nitric oxide signalling, reduced prostacyclin production, endothelin-1 (ET-1) upregulation, oxidative stress, and rarefaction have been implicated. Treatment of hypertension should be aimed at reducing the risk of short-term morbidity associated with hypertension while maintaining effective dosing of antiangiogenic therapy for optimal cancer treatment. Although specific guidelines are not yet available for the management of VEGFI-induced hypertension, angiotensin-converting enzyme inhibitors and dihydropyridine calcium channel blockers are commonly used. Severe hypertension might require reduction of VEGFI dosing, or in some cases, interruption of treatment. As more potent VEGFIs are developed and as more cancer patients are treated with VEGFIs, the burden of hypertension toxicity will increase. This will be further compounded as the use of antiangiogenic drugs broadens to include older patients and those with pre-existing cardiovascular disease. Here we focus on VEGF as a target for antiangiogenesis and how this affects increased blood pressure. Putative mechanisms underlying VEGFI-induced hypertension are highlighted and therapeutic strategies to manage such hypertension are discussed.

Orally active epoxyeicosatrienoic acid analog attenuates kidney injury in hypertensive Dahl salt-sensitive rat

Salt-sensitive hypertension leads to kidney injury. The Dahl salt-sensitive hypertensive rat (Dahl SS) is a model of salt-sensitive hypertension and progressive kidney injury. The current set of experimental studies evaluated the kidney protective potential of a novel epoxyeicosatrienoic acid analog (EET-B) in Dahl SS hypertension. Dahl SS rats receiving high-salt diet were treated with EET-B (10 mg/kg per day) or vehicle in drinking water for 14 days. Urine, plasma, and tissue samples were collected at the end of the treatment protocol to assess kidney injury, oxidative stress, inflammation, and endoplasmic reticulum stress. EET-B treatment in Dahl SS rats markedly reduced urinary albumin and nephrin excretion by 60% to 75% along with 30% to 60% reductions in glomerular injury, intratubular cast formation, and kidney fibrosis without affecting blood pressure. In Dahl SS rats, EET-B treatment further caused marked reduction in oxidative stress with 25% to 30% decrease in kidney malondialdehyde content along with 42% increase of nitrate/nitrite and a 40% reduction of 8-isoprostane. EET-B treatment reduced urinary monocyte chemoattractant protein-1 by 50% along with a 40% reduction in macrophage infiltration in the kidney. Treatment with EET-B markedly reduced renal endoplasmic reticulum stress in Dahl SS rats with reduction in the kidney mRNA expressions and immunoreactivity of glucose regulatory protein 78 and C/EBP homologous protein. In summary, these experimental findings reveal that EET-B provides kidney protection in Dahl SS rats by reducing oxidative stress, inflammation, and endoplasmic reticulum stress, and this protection was independent of reducing blood pressure.