New Directions in Therapeutic Angiogenesis and Arteriogenesis in Peripheral Arterial Disease.

The prevalence of peripheral arterial disease (PAD) in the United States exceeds 10 million people, and PAD is a significant cause of morbidity and mortality across the globe. PAD is typically caused by atherosclerotic obstructions in the large arteries to the leg(s). The most common clinical consequences of PAD include pain on walking (claudication), impaired functional capacity, pain at rest, and loss of tissue integrity in the distal limbs that may lead to lower extremity amputation. Patients with PAD also have higher than expected rates of myocardial infarction, stroke, and cardiovascular death. Despite advances in surgical and endovascular procedures, revascularization procedures may be suboptimal in relieving symptoms, and some patients with PAD cannot be treated because of comorbid conditions. In some cases, relieving obstructive disease in the large conduit arteries does not assure complete limb salvage because of severe microvascular disease. Despite several decades of investigational efforts, medical therapies to improve perfusion to the distal limb are of limited benefit. Whereas recent studies of anticoagulant (eg, rivaroxaban) and intensive lipid lowering (such as PCSK9 [proprotein convertase subtilisin/kexin type 9] inhibitors) have reduced major cardiovascular and limb events in PAD populations, chronic ischemia of the limb remains largely resistant to medical therapy. Experimental approaches to improve limb outcomes have included the administration of angiogenic cytokines (either as recombinant protein or as gene therapy) as well as cell therapy. Although early angiogenesis and cell therapy studies were promising, these studies lacked sufficient control groups and larger randomized clinical trials have yet to achieve significant benefit. This review will focus on what has been learned to advance medical revascularization for PAD and how that information might lead to novel approaches for therapeutic angiogenesis and arteriogenesis for PAD.

The Molecular Mechanism of EPO Regulates the Angiogenesis after Cerebral Ischemia through AMPK-KLF2 Signaling Pathway.

OBJECTIVE: In this study, the molecular mechanism by which EPO regulates the angiogenesis after cerebral ischemia through AMPK-KLF2 signaling pathway was investigated. METHODS: Sixty healthy, male, C57BL/6 mice were randomly divided into three groups of 20 mice: a sham group, the middle cerebral artery occlusion (MCAO) group, and a MCAO+EPO treatment group. The MCAO model was established using a modified ZeaLonga method. Mice in the EPO treatment group were injected with EPO immediately after reperfusion (5000 IU/kg), and EPO was injected the following day. The number of mouse deaths and neurologic function scores were recorded during the experiment. On day 7 after cerebral ischemia, brain tissue proteins were extracted. The following proteins expressions were detected by western blot assay: EPO, vascular endothelial growth factor (VEGE), vascular endothelial growth factor receptor (KDR), adenosine activated protein kinase (AMPK), and alpha HIF-1α alpha (HIF-1α), KLF2 and nitric oxide synthase (eNOS). RESULTS: Compared with the MCAO group, the survival rate of mice in the EPO group was significantly improved and neurological function was significantly improved (P < 0.01). Western blot results showed that the content of EPO in brain tissue in MCAO group significantly increased compared with sham group. The content of EPO in the brain tissue of mice in the MCAO+EPO treatment group was significantly higher than in that of the MCAO group, which indicates that EPO increased the content of EPO in mouse brain tissue. Compared with the sham group, the protein expression of vascular endothelial growth factor (VEGE) and its receptor (KDR) in brain tissue of the MCAO group significantly decreased. However, the protein expression of VEGE and its receptor KDR in brain tissue of rats treated with MCAO+EPO was significantly higher than in that of the MCAO group. Thus, in this study, EPO was associated with vascular endothelial differentiation after cerebral ischemia in mice. The results of AMPK and KLF2 showed that the expression levels of AMPK and KLF2 in brain tissues of MCAO group mice significantly decreased compared with the sham group. However, the expression levels of AMPK and KLF2 in brain tissues of mice treated with MCAO+EPO were significantly higher than those in the MCAO group. Thus, EPO can activate AMPK and upregulate the expression of the transcription factor KLF2. The protein expression of HIF-1α in the brain tissue of mice in the MCAO group significantly increased compared with the sham group. However, the expression of HIF-1α in mice brain tissues in the MCAO+EPO treatment group was significantly lower than in that of the MCAO group, indicating that EPO was involved in regulating HIF-1α expression. The eNOS results showed that, compared with Sham group, the protein expression of eNOS in brain tissue of MCAO group mice significantly decreased. In the MCAO+EPO treatment group, the protein expression of eNOS was significantly higher in the brain tissue of the mice than in that of the MCAO group, indicating that EPO was involved in the synthesis of NO and promoted the angiogenesis. CONCLUSION: EPO promotes VEGE and its receptor (KDR) expression and participates in the regulation of HIF-1α and eNOS protein expression through the activation of AMPK-KLF2 signaling pathways to promote new vascular development after cerebral ischemia.

The regulatory role of microRNAs in angiogenesis-related diseases.

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at a post-transcriptional level via either the degradation or translational repression of a target mRNA. They play an irreplaceable role in angiogenesis by regulating the proliferation, differentiation, apoptosis, migration and tube formation of angiogenesis-related cells, which are indispensable for multitudinous physiological and pathological processes, especially for the occurrence and development of vascular diseases. Imbalance between the regulation of miRNAs and angiogenesis may cause many diseases such as cancer, cardiovascular disease, aneurysm, Kawasaki disease, aortic dissection, phlebothrombosis and diabetic microvascular complication. Therefore, it is important to explore the essential role of miRNAs in angiogenesis, which might help to uncover new and effective therapeutic strategies for vascular diseases. This review focuses on the interactions between miRNAs and angiogenesis, and miRNA-based biomarkers in the diagnosis, treatment and prognosis of angiogenesis-related diseases, providing an update on the understanding of the clinical value of miRNAs in targeting angiogenesis.

Osteochondral Angiogenesis and Promoted Vascularization: New Therapeutic Target.

The control of the different angiogenic process is an important point in osteochondral regeneration. Angiogenesis is a prerequisite for osteogenesis in vivo; insufficient neovascularization of bone constructs after scaffold implantation resulted in hypoxia and cellular necrosis. Otherwise, angiogenesis must be avoided in chondrogenesis; vascularization of the cartilage contributes to structural damage and pain. Finding a balance between these processes is important to design a successful treatment for osteochondral regeneration. This chapter shows the most important advances in the control of angiogenic process for the treatment of osteochondral diseases focused on the administration of pro- or anti-angiogenic factor and the design of the scaffold.

PubAngioGen: a database and knowledge for angiogenesis and related diseases.

Angiogenesis is the process of generating new blood vessels based on existing ones, which is involved in many diseases including cancers, cardiovascular diseases and diabetes mellitus. Recently, great efforts have been made to explore the mechanisms of angiogenesis in various diseases and many angiogenic factors have been discovered as therapeutic targets in anti- or pro-angiogenic drug development. However, the resulted information is sparsely distributed and no systematical summarization has been made. In order to integrate these related results and facilitate the researches for the community, we conducted manual text-mining from published literature and built a database named as PubAngioGen (http://www.megabionet.org/aspd/). Our online application displays a comprehensive network for exploring the connection between angiogenesis and diseases at multilevels including protein-protein interaction, drug-target, disease-gene and signaling pathways among various cells and animal models recorded through text-mining. To enlarge the scope of the PubAngioGen application, our database also links to other common resources including STRING, DrugBank and OMIM databases, which will facilitate understanding the underlying molecular mechanisms of angiogenesis and drug development in clinical therapy.

Heparin/Heparan sulfate proteoglycans glycomic interactome in angiogenesis: biological implications and therapeutical use.

Angiogenesis, the process of formation of new blood vessel from pre-existing ones, is involved in various intertwined pathological processes including virus infection, inflammation and oncogenesis, making it a promising target for the development of novel strategies for various interventions. To induce angiogenesis, angiogenic growth factors (AGFs) must interact with pro-angiogenic receptors to induce proliferation, protease production and migration of endothelial cells (ECs). The action of AGFs is counteracted by antiangiogenic modulators whose main mechanism of action is to bind (thus sequestering or masking) AGFs or their receptors. Many sugars, either free or associated to proteins, are involved in these interactions, thus exerting a tight regulation of the neovascularization process. Heparin and heparan sulfate proteoglycans undoubtedly play a pivotal role in this context since they bind to almost all the known AGFs, to several pro-angiogenic receptors and even to angiogenic inhibitors, originating an intricate network of interaction, the so called "angiogenesis glycomic interactome". The decoding of the angiogenesis glycomic interactome, achievable by a systematic study of the interactions occurring among angiogenic modulators and sugars, may help to design novel antiangiogenic therapies with implications in the cure of angiogenesis-dependent diseases.

[EXPERIENCE OF SEVERE CHRONIC VENOUS INSUFFICIENCY OF THE LOWER EXTREMITIES TREATMENT].

The results of treatment of 246 patients on different forms of chronic venous insufficiency of the lower extremities were presented. The leading diagnostic criterion when choosing tactics consider patients ultrasound duplex scanning with color mapping. Patients in the presence of large ulcers basic treatment is autodermoplasty. The complex treatment include pharmacotherapy, the use of elastic compression hosiery.

Human epidermal growth factor receptor-2-positive breast cancer: Current management of early, advanced, and recurrent disease.

PURPOSE OF REVIEW: This review describes the current treatment of human epidermal growth factor receptor-2 (HER2)-positive breast cancer with a focus on recently reported clinical trials.Treatment of resistant disease and central nervous system metastases will be reviewed as will new agents that are being developed to target HER2-amplified breast cancers. RECENT FINDINGS: Recent studies evaluating trastuzumab-resistant breast cancer have shown a benefit of continuing trastuzumab with chemotherapy or with another HER2-targeted agent.Targeting the vascular endothelial growth factor, mammalian target of rapamycin, and PI3 kinase pathways in addition to HER2 may enhance efficacy compared with individual agents. Several novel anti-HER2 compounds are being evaluated with promising early data. SUMMARY: HER2-positive breast cancer has traditionally been associated with poor prognosis.However, treatment with HER2-targeted therapies has changed the natural history of this disease. Greater success depends on elucidating mechanisms of resistance and exploring new methods of blocking signal transduction via HER2 and related pathways.

Tumour vascularisation: a druggable target.

Tumour growth, spreading and metastasis require the development of a local vasculature. There have been great advances in the understanding of how this new vasculature arises, particularly in our increased knowledge of the process of angiogenesis, Although, a vast number of pro-angiogenic and anti-angiogenic mediators have been identified, one of the key signalling processes in the development of the tumour vasculature is the hypoxia-induced stimulation of vascular endothelial cell growth factors (VEGFs) production. Anti-VEGF therapy therefore not only provides a new paradigm for limiting tumour growth via targeting angiogenesis, but also provides prototypic agents to test the hypothesis that by controlling the development of the tumour vasculature we are able to limit, and potentially stop, tumour growth and spreading.

Angiopoietin-like proteins--potential therapeutic targets for metabolic syndrome and cardiovascular disease.

Recent major increases in obesity and related metabolic diseases (known as the metabolic syndrome (MetS)) because of sedentary lifestyles and overnutrition in developed and developing countries, are an exploding medical and social problem. These conditions are associated with increased risk of cardiovascular disease (CVD), the leading cause of death. Thus, it is necessary to understand the molecular basis underlying MetS and develop effective preventive and therapeutic approaches against CVD. To date, 7 angiopoietin-like proteins (Angptls) that are structurally similar to angiopoietins have been identified. However, none binds to the angiopoietin receptor, Tie2, or to the closely related Tie1 receptor, suggesting that these ligands function differently from angiopoietins. Some Angptls potently regulate angiogenesis, similar to angiopoietins, whereas others have pleiotropic activity other than angiogenesis and function in lipid and energy metabolism. In this review, we focus on the roles of Angptl2 and Angptl6/angiopoietin-like growth factor (AGF) in the development of MetS and CVD, and discuss the potential for Angptl2 and Angptl6/AGF to function as molecular targets for the prevention and treatment of both conditions.

The evolving role of interventional pulmonary in the interdisciplinary approach to the staging and management of lung cancer. Part III: diagnosis and management of malignant pleural effusions.

The diagnosis and management of a malignant pleural effusion can be one of the most vexing problems faced by physicians and their patients. Lung cancer is the most common primary tumor of origin with a prognosis that is limited, but variable and correlated with performance status (PS). Therefore, with a poor PS and known advanced lung cancer, establishing whether or not an effusion is malignant might not be necessary. Conversely, identifiable subsets of patients will have a much better survival, and establishing a definitive diagnosis could be of critical importance. In the great majority of cases, a diagnosis can be determined by serial thoracenteses with or without closed pleural biopsy. However, thoracoscopy is increasingly being utilized and can expedite the workup by obviating the need for repeated thoracenteses and/or closed pleural biopsy, while in the same setting providing definitive palliative treatment. Although studies comparing diagnostic and treatment strategies are limited, we will present the available data with the intention of providing the practicing oncologist with a practical strategy for the diagnosis and management of malignant pleural effusions due to lung cancer. The interventional pulmonologist can play an important role from diagnosis to palliation, greatly facilitating the care of patients with malignant pleural effusions.

[Results of treatments for critical limb ischemia: effectiveness and indications].

The treatment of critical limb ischemia (CLI), which is the end stage of arteriosclerosis obliterans and/or Buerger's disease, provides the ischemic tissue with oxygen, and arterial revascularization procedures such as bypass surgery and thromboendarterectomy, percutaneous transluminal angioplasty (PTA)/stent, sympathectomy, hyperbaric oxygenation, angiogenesis, medical treatment, etc. are performed. Successful bypass surgery on the crural and foot arteries is the most effective procedure, although it requires good skill and an autogenous vein of good quality. The results of thromboendarterectomy for the femoral artery are not sufficient and thromboendarterectomy for below-knee arteries is impossible. PTA/stent is the first choice of treatment for iliac arterial lesions. It is, however, not appropriate for below-knee arteries. Recently, many interventionists perform intraarterial treatment, although the intervention approved only because stenosis and/or occlusion is noted in the arteriogram. A correct diagnosis of the clinical severity of CLI in the leg is important for appropriate treatment. Sympathectomy of the lower limb is often effective in Buerger's disease. Hyperbaric oxygenation of the whole body is not currently performed. Angiogenesis is a new method, still in the experimental stage and its clinical effectiveness has not been confirmed. Anticoagulants, prostanoids, and antiplatelets are always necessary in the treatment of CLI.

Effects of local administration of vascular endothelial growth factor on mechanical characteristics of the semitendinosus tendon graft after anterior cruciate ligament reconstruction in sheep.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis. HYPOTHESIS: An application of VEGF may enhance angiogenesis in the grafted tendon in anterior cruciate ligament (ACL) reconstruction, and the application may affect mechanical characteristics of the ACL graft. STUDY DESIGN: Controlled laboratory study. METHODS: Eighteen sheep were divided into groups I and II. In group I, the harvested semitendinosus tendon was soaked in VEGF solution, and the right knee then underwent ACL reconstruction using this tendon. In group II, the right knee underwent identical procedures to those of group I except that the harvested tendon was soaked in phosphate-buffered saline. All animals were sacrificed 12 weeks after ACL reconstruction. RESULTS: Histologic findings showed that newly formed vessels and infiltrative fibroblasts were more abundant in group I than in group II. The anterior-posterior translation of the knee during an anterior-posterior force of +/- 100 N was significantly larger in group I than in group II by 2.58 mm (95% confidence interval, -1.76 mm to 1.76 mm) (P = .002). The linear stiffness of the femur-graft-tibia complex in group I was significantly lower than that in group II by 41.5 N/mm (95% confidence interval, -32.2 N/mm to 32.2 N/mm) (P = .017). CONCLUSION: This study has revealed that VEGF as administered in this study promotes angiogenesis in the ACL graft and significantly reduces the stiffness of the ACL graft with increased knee laxity at 12 weeks after ACL reconstruction. CLINICAL RELEVANCE: Exogenous VEGF application for ACL reconstruction can induce an increase in knee laxity and a decrease in the stiffness of the grafted tendon at least temporarily after ACL reconstruction. These potentially negative mechanical effects need to be taken into account when considering clinical use of VEGF.

Role of Isoprenoid Compounds on Angiogenic Regulation: Opportunities and Challenges.

Isoprenoids represent one of the largest classes of phytochemicals. The structural diversity of these compounds, as well as their remarkable biological activities, makes them suitable candidates for the development of novel therapeutic agents. Several isoprenoids have demonstrated promising potential in the modulation of angiogenesis processes, and therefore provide an appealing alternative and/or addition to the available pharmacotherapies. These compounds could be used per se or combined with standard therapies, which can potentially reduce the undesired secondary effects. Compounds like the sesquiterpenoid artemisinin, and its derivatives, or the diterpenoid triptolide have been successfully tested in a broad range of models (in vitro and in vivo). Moreover, sesquiterpenoids seem to be a promising resource of natural angiogenic modulators, as it can be attested by the significant number of recent publications in this subject. On the other hand, other isoprenoids, such as the triterpenoid ursolic acid, are still under-explored and further studies are needed to understand their role within angiogenic process. Further insights into isoprenoids mode of action in angiogenesis will hopefully pave the way towards their successful clinical use.

Reactive oxygen species and synthetic antioxidants as angiogenesis modulators: Clinical implications.

Angiogenesis is important for normal functioning of organism and its disturbances are observed in many diseases, called angiogenesis-related states. Reactive oxygen species (ROSs) play an important role in physiology, but high level of cellular ROSs is cytotoxic and mutagenic for the cells, i.e. it can lead to oxidative stress. In this review we discuss close relationship between ROSs and angiogenesis process. Substances counteracting free radicals or their action and oxidative stress are known as antioxidants. We postulate that antioxidants, by affecting angiogenesis, may modulate therapy results in the case of angiogenesis-related disease. Herein, we present some antioxidant preparations of synthetic (N-acetylcysteine, curcumin and its analogs, Probucol, oleane tripertenoid, EGCG synthetic analogs) and nature-identical (vitamin E and C) origin. Then, we analyze their angiogenic properties and their multidirectional molecular effect on angiogenesis. Most preparations reduce neovascularization and diminish the level of proangiogenic molecules, downregulating signaling pathways related to angiogenesis. Moreover, we discuss studies concerning anticancer properties of presented synthetic antioxidants and their application in several angiogenesis-related diseases. We conclude that therapy in angiogenesis-related diseases should be planned with consideration of the angiogenic status of the patient.

Metformin regulates ovarian angiogenesis and follicular development in a female polycystic ovary syndrome rat model.

Polycystic ovary syndrome (PCOS) is a frequent pathology that affects more than 5% of women of reproductive age. Among other heterogeneous symptoms, PCOS is characterized by abnormalities in angiogenesis. Metformin has been introduced in the treatment of PCOS to manage insulin resistance and hyperglycemia. Besides its metabolic effects, metformin has been shown to improve ovulation, pregnancy and live birth rates in PCOS patients. In the present study, we used a dehydroepiandrosterone-induced PCOS rat model to analyze the effect of metformin administration on ovarian angiogenesis. We found that metformin was able to restore the increased levels of vascular endothelial growth factor, angiopoietin (ANGPT)1, and ANGPT1/ANGPT2 ratio and the decreased levels of platelet-derived growth factor B and platelet-derived growth factor D observed in the dehydroepiandrosterone-treated rats. These effects could take place, at least in part, through a decrease in the levels of serum insulin. We also found an improvement in follicular development, with a lower percentage of small follicles and cysts and a higher percentage of antral follicles and corpora lutea after metformin administration. The improvement in ovarian angiogenesis is likely to restore the accumulation of small follicles observed in PCOS rats and to reduce cyst formation, thus improving follicular development and the percentage of corpora lutea. These results open new insights into the study of metformin action not only in glucose metabolism but also in ovarian dysfunction in PCOS women.

The aging of the retina.

This mini-review summarizes our current knowledge concerning the age-related changes that affect the retina. Over the last 10 years, our understanding of the genetics of hereditary retinal diseases has improved considerably. However, the modifications that occur in the retina as a result of aging are still under investigation. In this review, we place particular emphasis on the normal retinal alterations that occur with aging (gene modulation; psychophysical, structural and cellular alterations). We describe the events that occur during the pathological aging process, such as in age-related macular degeneration. Understanding these different modifications is essential if we are to find key players on which to base therapeutic interventions that may help to prevent the passage of normal aging process to the pathological aging process.

Resveratrol attenuates diabetic nephropathy via modulating angiogenesis.

Angiogenesis plays an important role in the pathogenesis of diabetic nephropathy (DN). In the present study, we investigated the therapeutic potential of resveratrol, a polyphenol with antiangiogenic activity in DN. In a type 1 diabetic rat model, resveratrol treatment blunted the increases of urine albumin excretion, kidney weight and creatinine clearance rate. The increases of glomerular diameter, mesangium accumulation, glomerular basement membrane thickness and renal fibrosis in diabetic rats were also reduced by resveratrol treatment. In the diabetic kidney, increased expression of vascular endothelial growth factor (VEGF), Flk-1 and angiopoietin 2, and reduced expression of Tie-2 were observed. These changes in angiogenic hormones and associated receptors were attenuated by resveratrol treatment. No changes in angiopoietin 1 expression were detected among each group of rats. Resveratrol also significantly downregulated high glucose-induced VEGF and Flk-1 expressions in cultured mouse glomerular podocytes and endothelial cells, respectively. These effects were attenuated by knocking-down silent information regulator 1 (Sirt1) expression. In contrast, upregulation of Sirt1 in cultured endothelial cells reduced Flk-1 expression. Increased permeability and cellular junction disruption of cultured endothelial cells caused by VEGF were also inhibited by resveratrol pretreatment. Taken together, the present study demonstrated that resveratrol may attenuate DN via modulating angiogenesis.

Biological therapies for the treatment of cutaneous wounds: phase III and launched therapies.

INTRODUCTION: Normal wound healing mechanisms can be overwhelmed in the setting of complex acute and chronic tissue injury. Biological therapies are designed to augment and/or restore the body's natural wound healing abilities. There are a variety of available and emerging technologies utilizing this approach that have demonstrated the ability to augment wound healing. AREAS COVERED: In this review, the clinical data on launched and emerging biological therapies for wound healing applications are summarized. The methodologies discussed include biological skin equivalents, growth factors/small molecules and stem cell-based therapies. EXPERT OPINION: While many products possess convincing clinical data demonstrating their efficacy in comparison to standard treatment options, more robust, controlled studies are needed to determine the relative value among established and emerging biological therapies. Future bioengineering and stem cell-based approaches are of particular interest due to the simultaneous correction of multiple deficiencies present in the nonhealing wound.