Overexpression of vascular endothelial growth factor 165 (VEGF165) protects cardiomyocytes against doxorubicin-induced apoptosis

Functional recovery of myocardial infarction by specific EBP-PR1P peptides bridging injectable cardiac extracellular matrix and vascular endothelial growth factor

Vascular endothelial growth factor (VEGF) is the most potent angiogenic factor and plays an important role in therapy of myocardial infarction (MI). Currently, how to retain regional concentration and decrease rapid diffusion is critical for its clinical application of VEGF. In recent years, the application of targeting peptides has been developed rapidly and provides new strategies for the sustained release of VEGF. In present study, a bi-functional EBP-PR1P peptide was designed and bridged VEGF to injectable cardiac extracellular matrix (c-ECM). Through EBP-PR1P peptides, VEGF could specifically bind with c-ECM to realize the sustained release, without impacting the bioactivity of VEGF. Then VEGF/EBP-PR1P/c-ECM scaffolds were constructed and administrated into rats with MI. The results showed VEGF/EBP-PR1P/c-ECM could promote angiogenesis, protect cardiomyocytes survival against apoptosis, and improve the recovery of cardiac function. In addition, the mechanism of EBP-PR1P/VEGF was also investigated which canonical downstream of VEGF-Akt signaling pathway was activated. These results showed specific VEGF/EBP-PR1P/c-ECM scaffolds served as promising delivery system for VEGF that facilitated the functional recovery of MI.

Current insights into cellular senescence and myotoxicity induced by doxorubicin

Doxorubicin is an anti-neoplasmic drug that prevents DNA replication but induces senescence and cellular toxicity. Intensive research has focused on strategies to alleviate the doxorubicin-induced skeletal myotoxicity. The aim of the present review is to critically discuss the relevant scientific evidence about the role of exercise and growth factor administration and offer novel insights about newly developed-tools to combat the adverse drug reactions of doxorubicin treatment on skeletal muscle. In the first part, we discuss current data and mechanistic details on the impact of doxorubicin on skeletal myotoxicity. We next, review key aspects about the role of regular exercise and the impact of growth factors either administered pharmacologically or via genetic interventions. Future strategies such as combination of exercise and growth factor administration remain to be established to combat the pharmacologically-induced myotoxicity.

Cardiotoxic effects of angiogenesis inhibitors

The development of new therapies for cancer has led to dramatic improvements in survivorship. Angiogenesis inhibitors represent one such advancement, revolutionising treatment for a wide range of malignancies. However, these drugs are associated with cardiovascular toxicities which can impact optimal cancer treatment in the short-term and may lead to increased morbidity and mortality in the longer term. Vascular endothelial growth factor inhibitors (VEGFIs) are associated with hypertension, left ventricular systolic dysfunction (LVSD) and heart failure as well as arterial and venous thromboembolism, QTc interval prolongation and arrhythmia. The mechanisms behind the development of VEGFI-associated LVSD and heart failure likely involve the combination of a number of myocardial insults. These include direct myocardial effects, as well as secondary toxicity via coronary or peripheral vascular damage. Cardiac toxicity may result from the 'on-target' effects of VEGF inhibition or 'off-target' effects resulting from inhibition of other tyrosine kinases. Similar mechanisms may be involved in the development of VEGFI-associated right ventricular (RV) dysfunction. Some VEGFIs can be associated with QTc interval prolongation and an increased risk of ventricular and atrial arrhythmia. Further pre-clinical and clinical studies and trials are needed to better understand the impact of VEGFI on the cardiovascular system. Once mechanisms are elucidated, therapies can be investigated in clinical trials and surveillance strategies for identifying VEGFI-associated cardiovascular complications can be developed.

[Molecular mechanisms of the cardiotoxic action of anthracycline antibiotics and statin-induced cytoprotective reactions of cardiomyocytes]

The manifestation of the side cardiotoxic effect of anthracycline antibiotics limits their use in the treatment of malignant processes in some patients. The review analyzes the main causes of the susceptibility of cardiomyocytes to the damaging effect of anthracyclines, primarily associated with an increase in the processes of free radical oxidation. Currently, research is widely carried out to find ways to reduce anthracycline cardiotoxicity, in particular, the use of cardioprotective agents in the complex treatment of tumors. Hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) have been shown to improve the function and metabolism of the cardiovascular system under various pathological impacts, therefore, it is proposed to use them to reduce cardiotoxic complications of chemotherapy. Statins exhibit direct (hypolipidemic) and pleiotropic effects due to the blockade of mevalonic acid synthesis and downward biochemical cascades that determine their cardioprotective properties. The main point of intersection of the pharmacological activity of anthracyclines and statins is the ability of both to regulate the functioning of small GTPase from the Rho family, and their effect in this regard is the opposite. The influence of statins on the modification and membrane dislocation of Rho proteins mediates the indirect antioxidant, anti-inflammatory, endothelioprotective, antiapoptotic effect. The mechanism of statin inhibition of doxorubicin blockade of the DNA-topoisomerase complex, which may be important in preventing cardiotoxic damage during chemotherapy, is discussed. At the same time, it should be noted that the use of statins can be accompanied by adverse side effects: a provocation of increased insulin resistance and glucose tolerance, which often causes them to be canceled in patients with impaired carbohydrate metabolism, so further studies are needed here. The review also analyzes data on the antitumor effect of statins, their ability to sensitize the tumor to treatment with cytostatic drug. It has been shown that the relationship between anthracycline antibiotics and statins is characterized not only by antagonism, but also in some cases by synergism. Despite some adverse effects, statins are one of the most promising cardio- and vasoprotectors for use in anthracycline cardiomyopathy.

Updates in Anthracycline-Mediated Cardiotoxicity

Cardiotoxicity is one of the main adverse effects of chemotheraphy, affecting the completion of cancer therapies and the short- and long-term quality of life. Anthracyclines are currently used to treat many cancers, including the various forms of leukemia, lymphoma, melanoma, uterine, breast, and gastric cancers. World Health Organization registered anthracyclines in the list of essential medicines. However, anthracyclines display a major cardiotoxicity that can ultimately culminate in congestive heart failure. Taking into account the growing rate of cancer survivorship, the clinical significance of anthracycline cardiotoxicity is an emerging medical issue. In this review, we focus on the key progenitor cells and cardiac cells (cardiomyocytes, fibroblasts, and vascular cells), focusing on the signaling pathways involved in cellular damage, and the clinical biomarkers in anthracycline-mediated cardiotoxicity.

Combination therapy of hepatocellular carcinoma by DNA shuffling-based VEGF vaccine and doxorubicin

Antiangiogenic therapy can enhance the efficacy of chemotherapy against solid tumors. This study was to determine whether TT46, a potential VEGF vaccine from DNA shuffling with a helper T-cell epitope of tetanus toxin B subunit, could enhance the efficacy of doxorubicin to combat hepatocellular carcinoma (HCC). Compared with monotherapy, the combination with TT46 vaccination and doxorubicin could significantly reduce microvessel counts and inhibit tumor angiogenesis. Enhanced immunization with TT46 for total six doses could induce long-term response maintenance with high anti-VEGF antibody titers in body. As a result, the combination with enhanced TT46 vaccination and doxorubicin significantly inhibited the HCC growth, and improved the survival rate of HCC-bearing mice in both of subcutaneous tumor model and lung metastasis model. In conclusion, the combined therapy with TT46 vaccination and doxorubicin has antitumor effects in both a prophylactic and therapeutic setting in a mouse model of H22 hepatocellular carcinoma.

von Willebrand factor regulation of blood vessel formation

Several important physiological processes, from permeability to inflammation to hemostasis, take place at the vessel wall and are regulated by endothelial cells (ECs). Thus, proteins that have been identified as regulators of one process are increasingly found to be involved in other vascular functions. Such is the case for von Willebrand factor (VWF), a large glycoprotein best known for its critical role in hemostasis. In vitro and in vivo studies have shown that lack of VWF causes enhanced vascularization, both constitutively and following ischemia. This evidence is supported by studies on blood outgrowth EC (BOEC) from patients with lack of VWF synthesis (type 3 von Willebrand disease [VWD]). The molecular pathways are likely to involve VWF binding partners, such as integrin αvβ3, and components of Weibel-Palade bodies, such as angiopoietin-2 and galectin-3, whose storage is regulated by VWF; these converge on the master regulator of angiogenesis and endothelial homeostasis, vascular endothelial growth factor signaling. Recent studies suggest that the roles of VWF may be tissue specific. The ability of VWF to regulate angiogenesis has clinical implications for a subset of VWD patients with severe, intractable gastrointestinal bleeding resulting from vascular malformations. In this article, we review the evidence showing that VWF is involved in blood vessel formation, discuss the role of VWF high-molecular-weight multimers in regulating angiogenesis, and review the value of studies on BOEC in developing a precision medicine approach to validate novel treatments for angiodysplasia in congenital VWD and acquired von Willebrand syndrome.

Cardiotoxicity with vascular endothelial growth factor inhibitor therapy

Angiogenesis inhibitors targeting the vascular endothelial growth factor (VEGF) signaling pathway (VSP) have been important additions in the therapy of various cancers, especially renal cell carcinoma and colorectal cancer. Bevazicumab, the first VSP to receive FDA approval in 2004 targeting all circulating isoforms of VEGF-A, has become one of the best-selling drugs of all times. The second wave of tyrosine kinase inhibitors (TKIs), which target the intracellular site of VEGF receptor kinases, began with the approval of sorafenib in 2005 and sunitinib in 2006. Heart failure was subsequently noted, in 2-4% of patients on bevacizumab and in 3-8% of patients on VSP-TKIs. The very fact that the single-targeted monoclonal antibody bevacizumab can induce cardiotoxicity supports a pathomechanistic role for the VSP and the postulate of the "vascular" nature of VSP inhibitor cardiotoxicity. In this review we will outline this scenario in greater detail, reflecting on hypertension and coronary artery disease as risk factors for VSP inhibitor cardiotoxicity, but also similarities with peripartum and diabetic cardiomyopathy. This leads to the concept that any preexisting or coexisting condition that reduces the vascular reserve or utilizes the vascular reserve for compensatory purposes may pose a risk factor for cardiotoxicity with VSP inhibitors. These conditions need to be carefully considered in cancer patients who are to undergo VSP inhibitor therapy. Such vigilance is not to exclude patients from such prognostically extremely important therapy but to understand the continuum and to recognize and react to any cardiotoxicity dynamics early on for superior overall outcomes.

Genetic and ethnic modulation of cardiovascular toxicity of vascular endothelial growth factor inhibitors

Vascular endothelial growth factor (VEGF) inhibitors, including monoclonal antibodies and tyrosine kinase inhibitors (TKIs), are important as anticancer treatments through curbing tumour angiogenesis and growth. VEGF inhibitors have significant cardiovascular effects. By blocking VEGF receptors, ligands, or signal pathways, VEGF inhibitors disturb the balance between vasodilation and vasoconstriction, undermine endothelial cell integrity, and activate cardiomyocyte apoptosis. VEGF inhibitors increase risks of hypertension, heart failure, thromboembolism and arrhythmia. Genetic and geographic studies showed that genetic polymorphisms likely play significant predictive or prognostic roles in cardiovascular toxicity associated with VEGF inhibitors. This review updates current understandings of VEGF inhibitors on cardiovascular toxicity, explores potential mechanisms, and clarifies whether genetic or ethnic factors contribute to their adverse effects. Key Messages VEGF inhibitors disturb the balance between vasodilation and vasoconstriction, undermine endothelial cell integrity and activate cardiomyocyte apoptosis. VEGF inhibitors increase risks of hypertension, heart failure, thromboembolism and arrhythmia. Genetic and geographic studies showed that genetic polymorphisms likely play significant predictive or prognostic roles in cardiovascular toxicity associated with VEGF inhibitors.

Mechanistic clues to the protective effect of chrysin against doxorubicin-induced cardiomyopathy: Plausible roles of p53, MAPK and AKT pathways

Doxorubicin (DOX) is the mainstay chemotherapeutic agent against a variety of human neoplasmas. However, its clinical utility is limited by its marked cardiotoxicity. Chrysin, is a natural flavone which possesses antioxidant, anti-inflammatory and anti-cancer properties. The current study aimed to investigate the potential protective effect of chrysin against DOX-induced chronic cardiotoxicity and the underlying molecular mechanisms. Male Sprague-Dawley rats were treated with either DOX (5 mg/kg, once a week) and/or chrysin (50 mg/kg, four times a week) for four weeks. Chrysin prevented DOX-induced cardiomyopathy which was evident by conduction abnormalities, elevated serum CKMB and LDH and histopathological changes. Chrysin also ameliorated DOX-induced oxidative stress by decreasing lipid peroxidation and upregulating the antioxidant enzymes. Moreover, chrysin attenuated DOX-induced apoptosis via decreasing expression of p53, Bax, Puma, Noxa, cytochrome c and caspase-3 while increasing expression of Bcl-2. DOX induced activation of MAPK; p38 and JNK and increased expression of NF-κB. Meanwhile, DOX suppressed AKT pathway via decreasing expression of its upstream activator VEGF and increasing expression of PTEN. Conversely, chrysin effectively neutralised all these effects. Collectively, these findings indicate that chrysin effectively protected against DOX-induced cardiomyopathy via suppressing oxidative stress, p53-dependent apoptotic pathway, MAPK and NF-κB pathways while augmenting the VEGF/AKT pathway.

Effects of rhodiola crenulata on mice hearts under severe sleep apnea

BACKGROUND

The goal of this study is to determine if Rhodiola Crenulata (RC) has protective effects on mice hearts with severe sleep apnea model.

METHODS

Sixty-four C57BL/6 J mice 5-6 months old were distributed into 4 groups i.e. Control group (21% O2, 24 h per day, 8 weeks, n=16); Hypoxia group (Hypoxia: 7% O2 60 s, 20% O2 alternating 60 s, 8 h per day, 8 weeks, n=16); Hypoxia+90RC and Hypoxia+270RC group (Hypoxia for 1st 4 weeks and hypoxia pretreated 90 mg/Kg and 270 mg/Kg Rhodiola Crenulata by oral gavage per day for 2nd 4 weeks, each n=16). Excised hearts from 4 groups of mice were analyzed for heart weight index changes using H&E staining, TUNEL-positive assays and Western Blotting protein.

RESULTS

Cardiac widely dispersed TUNEL-positive apoptotic cells in mice hearts were less in Hypoxia+RC90 and Hypoxia+RC270 than those in Hypoxia. Compared with Hypoxia, the protein levels of Fas ligand, Fas death receptors, Fas-Associated Death Domain (FADD), activated caspase 8, and activated caspase 3 (Fas dependent apoptotic pathways) were decreased in Hypoxia+RC90, Hypoxia+RC270. The protein levels of Bad, Bax, t-Bid, activated caspase 9, activated caspase 3 (mitochondria dependent apoptotic pathway) were less in Hypoxia+RC90, Hypoxia+RC270 than those in hypoxia. The protein levels of Bcl2, Bcl-xL, p-Bad (Bcl2-realted anti-apoptotic pathway) and VEGF, p-PI3k, p-AKT (VEGF-related pro-survival pathway) were higher in Hypoxia+RC90, Hypoxia+RC270 than those in hypoxia.

CONCLUSIONS

Our findings suggest that Rhodiola Crenulata have protective effects on chronic intermittent hypoxia-induced cardiac widely dispersed apoptosis via Fas-dependent and mitochondria-dependent apoptotic and VEGF-related pro-survival pathway.

Decreased vascular endothelial growth factor expression is associated with cell apoptosis in low-dose aspirin-induced gastric mucosal injury

BACKGROUND

The use of low-dose aspirin (LDA) has emerged as an important cause of gastrointestinal ulcers. The aim of this study was to investigate the association between LDA-induced gastric mucosal injury and the expression of vascular endothelial growth factor (VEGF) and cell apoptosis in elderly Chinese patients.

METHODS

A total of 136 patients aged 60 to 80 years with LDA-induced (100 mg/d for at least 1 month) gastric mucosal injury and 48 age-matched healthy subjects were enrolled in this study. The patients were divided into a low-severity group and a high-severity group based on their modified Lanza scale scores. Biopsy specimens of gastric mucosa from all participants were subjected to immunohistochemical staining for VEGF expression and terminal deoxynucleotidyl transferase dUTP nick end labeling staining for cell apoptosis. Staining indices and apoptotic indices were applied to assess VEGF expression level and the extent of cell apoptosis.

RESULTS

VEGF expression decreased significantly in the 2 patient groups, whereas the extent of cell apoptosis significantly increased compared with the control group. Furthermore, Spearman's correlation coefficients suggest that VEGF expression levels and the extent of cell apoptosis in gastric mucosae shared a significant correlation with the severity of LDA-induced gastric mucosal injury. Receiver operating characteristics analysis further confirmed these results.

CONCLUSIONS

Our findings provide important clues as to the underlying molecular mechanism behind gastric mucosal injury resulting from exposure to LDA in elderly adults, and also suggest that interventions specifically targeting the pathways associated with angiogenesis and apoptosis may help facilitate the healing process.

Calcium-alginate hydrogel-encapsulated fibroblasts provide sustained release of vascular endothelial growth factor

Vascularization of engineered or damaged tissues is essential to maintain cell viability and proper tissue function. Revascularization of the left ventricle (LV) of the heart after myocardial infarction is particularly important, since hypoxia can give rise to chronic heart failure due to inappropriate remodeling of the LV after death of cardiomyocytes (CMs). Fibroblasts can express vascular endothelial growth factor (VEGF), which plays a major role in angiogenesis and also acts as a chemoattractant and survival factor for CMs and cardiac progenitors. In this in vitro model study, mouse NIH 3T3 fibroblasts encapsulated in 2% w/v Ca-alginate were shown to remain viable for 150 days. Semiquantitative reverse transcription-polymerase chain reaction and immunohistochemistry demonstrated that over 21 days of encapsulation, fibroblasts continued to express VEGF, while enzyme-linked immunosorbent assay showed that there was sustained release of VEGF from the Ca-alginate during this period. The scaffold degraded gradually over the 21 days, without reduction in volume. Cells released from the Ca-alginate at 7 and 21 days as a result of scaffold degradation were shown to retain viability, to adhere to fibronectin in a normal manner, and continue to express VEGF, demonstrating their potential to further contribute to maintenance of cardiac function after scaffold degradation. This model in vitro study therefore demonstrates that fibroblasts encapsulated in Ca-alginate provide sustained release of VEGF.

Cancer drugs and the heart: importance and management

Progress in the detection and treatment of cancer has led to an impressive reduction in both mortality and morbidity. Due to their mechanism of action, however, conventional chemotherapeutics and some of the newer anti-cancer signaling inhibitors carry a substantial risk of cardiovascular side effects that include cardiac dysfunction and heart failure, arterial hypertension, vasospastic and thromboembolic ischaemia, dysrhythmia, and QT prolongation. While some of these side effects are irreversible and cause progressive cardiovascular disease, others induce only temporary dysfunction with no apparent long-term sequelae for the patient. The challenge for the cardiovascular specialist is to balance the need for life-saving cancer treatment with the assessment of risk from cancer drug-associated cardiovascular side effects to prevent long-term damage. This review discusses concepts for timely diagnosis, intervention, and surveillance of cancer patients undergoing treatment, and provides approaches to clinical uncertainties.

Effects of Doxorubicin and Fenofibrate on the activities of NADH oxidase and citrate synthase in mice

Doxorubicin (Dox) has widely been used as an anticancer drug, but its use is limited by serious toxicity to the heart, kidney and liver. Mitochondrial dysfunction is one of the potential mechanisms of toxicity but not fully understood. Fenofibrate, one of the peroxisome proliferator-activated receptor-alpha (PPARα) ligands, is involved in lipid metabolism which takes place primarily in the mitochondria, so mitochondrial function may be affected by fenofibrate. Therefore, we investigated the effects of DOX and fenofibrate on activities of both mitochondrial citrate synthase and NADH oxidase, which are marker enzymes in the tricarboxylic acid (TCA) cycle and a measure of the complex I-III-IV activity in electron transport chain, respectively. Dox (15 mg/kg) and/or fenofibrate (100 mg/kg/day) were administered to mice for 3 or 14 days, and the activities of citrate synthase and NADH oxidase were measured. Our study showed that Dox significantly inhibits the activity of citrate synthase while fenofibrate induces the activity. Similar to citrate synthase, NADH oxidase activity was also induced by fenofibrate except in spleen but inhibited by Dox except in the heart and liver. Furthermore, fenofibrate not only protects citrate synthase activity from Dox-induced toxicity in the ventricle but also significantly rescues NADH oxidase activity in the kidney. These results reveal the actions of fenofibrate and Dox on the mitochondria, and the underlying mechanism may be related to the toxicity of Dox, which has clinical implications in the side effects of Dox treatment by modulation of mitochondrial function.