Induction Of Angiogenesis Research Articles

Abstract 1982: Sustained CXCR2 signaling promotes secretory phenotype in cancer-associated fibroblasts of pancreatic cancer via activation of NFkB

Abstract Pancreatic cancer (PC) is the fourth leading cause of cancer-related deaths in the US and remains one of the most challenging malignancies. Desmoplasia and tumor-supporting inflammation are hallmarks of PC. In addition to the autonomous aggressiveness feature of PC malignant cells, host tumor microenvironment contribute greatly to tumor progression and spread. Cancer-associated fibroblasts (CAFs), represent the major component of the tumor microenvironment in PC, are implicated in facilitating therapy resistance and metastasis. Recent reports emphasize the concurrence of multiple subtypes of CAFs that carry out different functions. CXCR2 is a chemokine receptor that is known for its role during inflammation by recruiting innate immune cells and the induction of angiogenesis. In PC, oncogenic Kras upregulates CXCR2 and its ligands (CXCL1-3 and 5-8), which are linked to inducing tumor proliferation and immunosuppression as well as induction of malignant cells stemness contributing to therapy resistance. Deletion of CXCR2 in a syngeneic mouse model (Cxcr2-/-) of PC increased the abundance of fibrosis revealing a potential undescribed role of CXCR2 in regulating CAFs. We hypothesize that CXCR2 regulates CAFs function in PC and contribute to CAFs heterogeneity. Co-culture of PC tumor cells in the conditioned media of CAFs and co-culturing CAFs in conditioned media of tumor cells revealed an oncogenic Kras-dependent interaction. CAFs enhanced the growth of PC cells with oncogenic Kras; whereas, conditioned media of the PC cells with oncogenic Kras has inhibited CAFs growth. Paracrine factors derived from tumor cells decreased the expression of the fibrotic CAFs-associated markers including αSMA and collagen I, and increased the expression of immunosuppressive cytokines and tumor-promoting chemokines including IL-4, IL-10, IL-13 and CXCL7. Utilizing recombinant CXCR2 chemokines and CXCR2 inhibitors, we confirmed the involvement of CXCR2 in this secretory phenotype. CXCL1 and CXCL8 exhibited a similar effect on CAFs by downregulating αSMA and upregulating IL-4, IL-13 and CXCL7. CXCR2 inhibitors reverted some of the observed effects. Examining downstream signaling pathways revealed that this effect is mediated through activation of NFκB. We further confirmed these findings in-vivo. Immunohistochemistry revealed higher αSMA expression in the tumors implanted in Cxcr2-/- compared to wildtype mice. Altogether, we demonstrate that sustained signaling through CXCR2 activates NFκB and induces a secretory phenotype of CAFs in PC that upregulates pro-tumor immunosuppression growth factors. Citation Format: Mohammad Awaji, Michelle Varney, Abhilasha Purohit, Lingyun Wu, Sugandha Saxena, Sushil Kumar, Surinder K. Batra, Rakesh K. Singh. Sustained CXCR2 signaling promotes secretory phenotype in cancer-associated fibroblasts of pancreatic cancer via activation of NFkB [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1982.

Delayed Postconditioning with External Volume Expansion Improves Survival of Adipose Tissue Grafts in a Murine Model.

BACKGROUND External volume expansion improves the survival of adipose tissue grafts by preoperatively conditioning ("preconditioning") tissues that will receive the graft. External volume expansion's mechanisms of action (induction of angiogenesis and of adipogenesis) could improve graft survival also when applied postoperatively ("postconditioning"). METHODS Fifty-six 8-week-old athymic (nu/nu) mice received dorsal subcutaneous grafts of human lipoaspirate (0.3 ml each) bilaterally before undergoing external volume expansion (left dorsum) or no treatment (right dorsum, controls). External volume expansion was started either on the same day of (immediate group), 2 days after (early group), or 1 week after surgery (delayed group). At follow-up, grafts were analyzed for tissue survival, remodeling, adipogenesis, and angiogenesis using histology. The authors subsequently assessed the effects of the delayed application of external volume expansion adopting a foam-shaped interface to deliver the treatment. RESULTS At 28-day follow-up, delayed postconditioning with external volume expansion significantly improved the survival of grafts (18 percent) compared with controls (viable graft thickness ratio, 58 ± 15 percent versus 49 ± 13 percent) and increased the density of blood vessels within the graft (63 percent; blood vessels per 10× magnification field, 44 ± 12 versus 27 ± 11). Other groups did not experience significant changes. Adoption of external volume expansion with a foam-shaped interface similarly improved outcomes and further reduced fibrosis within the grafts. CONCLUSIONS Postoperative delayed application of external volume expansion modestly improves the survival of adipose tissue grafts by inducing adipogenesis and angiogenesis. Use of a foam-shaped interface decreases the fibrosis induced in the grafts.

Local pharmacological induction of angiogenesis: Drugs for cells and cells as drugs

The past decades have seen significant advances in pro-angiogenic strategies based on delivery of molecules and cells for conditions such as coronary artery disease, critical limb ischemia and stroke. Currently, three major strategies are evolving. Firstly, various pharmacological agents (growth factors, interleukins, small molecules, DNA/RNA) are locally applied at the ischemic region. Secondly, preparations of living cells with considerable bandwidth of tissue origin, differentiation state and preconditioning are delivered locally, rarely systemically. Thirdly, based on the notion, that cellular effects can be attributed mostly to factors secreted in situ, the cellular secretome (conditioned media, exosomes) has come into the spotlight. We review these three strategies to achieve (neo)angiogenesis in ischemic tissue with focus on the angiogenic mechanisms they tackle, such as transcription cascades, specific signalling steps and cellular gases. We also include cancer-therapy relevant lymphangiogenesis, and shall seek to explain why there are often conflicting data between in vitro and in vivo. The lion's share of data encompassing all three approaches comes from experimental animal work and we shall highlight common technical obstacles in the delivery of therapeutic molecules, cells, and secretome. This plethora of preclinical data contrasts with a dearth of clinical studies. A lack of adequate delivery vehicles and standardised assessment of clinical outcomes might play a role here, as well as regulatory, IP, and manufacturing constraints of candidate compounds; in addition, completed clinical trials have yet to reveal a successful and efficacious strategy. As the biology of angiogenesis is understood well enough for clinical purposes, it will be a matter of time to achieve success for well-stratified patients, and most probably with a combination of compounds.

Sitagliptin protects diabetic rats with acute myocardial infarction through induction of angiogenesis: role of IGF-1 and VEGF.

Angiogenesis is regulated in a tissue-specific manner in all patients, especially those with diabetes. In this study, we describe a novel molecular pathway of angiogenesis regulation in diabetic rats with myocardial infarction (MI) and examine the cardioprotective effects of different doses of sitagliptin. Male rats were divided into 5 groups: normal vehicle group, diabetic group, diabetic + MI, diabetic + MI + 5 mg/kg sitagliptin, and diabetic + MI + 10 mg/kg sitagliptin. Isoproterenol in diabetic rats resulted in significant (p < 0.05) disturbance to the electrocardiogram, cardiac histopathological manifestations, and an increase in inflammatory markers compared with the vehicle and diabetic groups. Treatment with sitagliptin improved the electrocardiogram and histopathological sections, upregulated vascular endothelial growth factor (VEGF) and transmembrane phosphoglycoprotein protein (CD34) in cardiac tissues, and increased serum insulin-like growth factor 1 (IGF-1) and decreased cardiac tissue homogenate for interleukin 6 (IL-6) and cyclooxygenase 2 (COX-2). A relationship was found between serum IGF-1 and cardiac VEGF and CD34 accompanied by an improvement in cardiac function of diabetic rats with MI. Therefore, the observed effects of sitagliptin occurred at least partly through an improvement in angiogenesis and the mitigation of inflammation. Consequently, these data suggest that sitagliptin may contribute, in a dose-dependent manner, to protection against acute MI in diabetic individuals.

The effect of modified electrospun PCL-nHA-nZnO scaffolds on osteogenesis and angiogenesis.

Large bone defects treatment is one of the challenges in current bone tissue engineering approaches. Various strategies have been proposed to address this issue, among which, prevascularization by coculturing of angiogenic and osteogenic cells on the scaffolds can alleviate this problem. In the present study, modified fibrous scaffolds were prepared by electrospinning and subsequent ultrasonication of polycaprolactone (PCL) containing nano-hydroxyapatite (n-HA), with/without nano-zinc oxide (n-ZnO), and polyethylene oxide [PEO] as a sacrificial agent. The physical, mechanical, and chemical characteristics of the scaffolds were evaluated. The results showed the presence of n-ZnO, which in turn increased Young's module of the scaffolds from 5.5 ± 0.67 to 6.7 ± 1.77 MPa. Moreover, MTT, SEM, alkaline phosphatase (ALP) activity, chicken embryo chorioallantoic membrane (CAM) assay, and real-time RT-PCR were utilized to investigate the biocompatibility, cell adhesion and infiltration, osteoconductivity, angiogenic properties, and expression of osteogenic and angiogenic related genes. ALP assay showed that the highest enzyme activity was noted when the modified scaffolds containing n-ZnO were seeded with HUVEC:hBMSC at the cell ratio of 1:5. CAM assay showed induction of angiogenesis for the scaffolds containing n-ZnO. Real-time RT-PCR results showed significant upregulation of angiogenic related genes. Thus, the scaffolds containing n-ZnO may have great potential for osteogenesis and angiogenesis in tissue engineering applications.

Maternal cigarette smoking and expression of selected micro-RNAS in the plasma collected after spontaneous vaginal delivery

Several studies have shown a gradual increase in the extent of bone marrow angiogenesis in various stages of proliferative plasma cell disorders, from monoclonal gammopathy of undetermined significance (MGUS) to active multiple myeloma (MM). The main aim of this study was to evaluate tumor angiogenesis parameters in detail and to correlate them with the expression of osteopontin (OPN) and vascular endothelial growth factor (VEGF) in the bone marrow of patients with MGUS and MM. In addition, we wanted to determine their prognostic significance in active MM.Ninety-five patients were enrolled in the study: 14 diagnosed with MGUS, 13 with asymptomatic myeloma (AMM) and 68 with active MM. Computer assisted image analysis was used to determine the angiogenesis parameters, the quantity of microvessels per 1 mm2 (MVD), the area occupied by microvessels per 1 mm2 and the percentage of microvessel area in total section area (TVA). Double immunohistochemical methods CD138 + VEGF and CD138 + OPN were used to evaluate expression of these proteins in plasma cells, and OPN was also analyzed for its interstitial expression (iOPN).A significant positive correlation was determined between VEGF and iOPN with angiogenic parameters in the MGUS stage of the disease. In advanced stages of the disease, a significant negative correlation was recorded between OPN and iOPN with parameters of angiogenesis. Overall survival was significantly shorter for patients with negative iOPN (p = 0.002) and higher angiogenic parameters, MVD (p = 0.009), TVA (p = 0.008) and area of microvessels per 1 mm2 (p = 0.02). Positive VEGF expression in our model predicted a better three-year survival of patients with active MM (OR: 5.25, p = 0.03; HR: 0.44, p = 0.04).The results of our study suggested a possible key role of VEGF and OPN in the induction of angiogenesis in early-stage disease.

Carbonate apatite granules with uniformly sized pores that arrange regularly and penetrate straight through granules in one direction for bone regeneration

Abstract Artificial bone substitutes that can solve the problems associated with autogenous bone grafts are essential. In this study, macroporous carbonate apatite (CO3Ap) granules with the same composition as natural bone were implanted into distal epiphysis defects in rabbit femurs. Material resorption and bone regeneration were then evaluated. The macroporous granules were obtained by extruding honeycomb (HC) structure rods containing calcium hydroxide, pulverizing the rods to granules, carbonating them to calcite, and converting them from calcite to CO3Ap. Notably, the HC-type macropores fully penetrated and spanned their diameters of the CO3Ap granules in one direction, as well as being regularly arranged and uniformly sized (120 μm). They facilitated cell penetration into the granules and the induction of angiogenesis. As a result, bone remodeling occurred simultaneously within the granules and on the granule surfaces. Furthermore, the granules were gradually resorbed and replaced by bone. Thus, introducing HC-type macropores into granules is an effective approach for promoting bone regeneration.

Therapeutic potential of pravastatin for random skin flaps necrosis: involvement of promoting angiogenesis and inhibiting apoptosis and oxidative stress.

Background: Random skin flap is frequently used in plastic and reconstructive surgery, but its distal part often occurs ischemia and necrosis. Pravastatin (Prava) with bioactivities of pro-angiogenesis, anti-apoptosis and anti-oxidative stress, may be beneficial for flap survival.Materials and methods: A modified McFarlane flap model was performed in Sprague-Dawley rats. The animals were divided into the Control and Prava groups and treated as follows: the Prava group was injected intraperitoneally with 2 mg/kg Prava for consecutive 7 days, and the Control group received an equal volume of vehicle daily. On day 7, the necrosis skin flaps were observed, while visualization of blood flow below the tissue surface was performed by Laser Doppler blood flow imaging (LDBFI). Then animals were euthanized, and levels of angiogenesis, apoptosis and oxidative stress were analyzed.Results: Prava decreased necrosis and edema of skin flaps compared with the Control group, with more blood flow in the flap under LDBFI. Prava treatment increased the mean vessels density, elevated the expression levels of angiogenic proteins (matrix metallopeptidase 9, vascular endothelial growth factor, Cadherin5) and antioxidant proteins (superoxide dismutase 1 (SOD1), endothelial nitric oxide synthase, heme oxygenase), and decreased the expression of apoptotic factors (BAX, CYC, Caspase3). In addition, malondialdehyde content was reduced, and glutathione level and SOD activity were increased in the skin flaps after treatment with Prava.Conclusion: Prava promotes survival of random skin flap through induction of angiogenesis, and inhibition of apoptosis and oxidative stress.

Stem Cell-Mediated Angiogenesis in Tissue Engineering Constructs.

Angiogenesis has always been a concern in the field of tissue engineering. Poor vascularization of engineered constructs is a problem for the clinical success of these structures. Among the various methods employed to induce angiogenesis, stem cells provide a promising tool for the future. The present review aims to present the application of stem cells in the induction of angiogenesis. Additionally, it summarizes recent advancements in stem cell-mediated angiogenesis of different tissue engineering constructs.

Proteomic analysis of human mesenchymal stromal cell secretomes: a systematic comparison of the angiogenic potential

Human mesenchymal stromal cell (hMSC) secretomes have shown to influence the microenvironment upon injury, promoting cytoprotection, angiogenesis, and tissue repair. The angiogenic potential is of particular interest for the treatment of ischemic diseases. Interestingly, hMSC secretomes isolated from different tissue sources have shown dissimilarities with respect to their angiogenic profile. This study compares angiogenesis of hMSC secretomes from adipose tissue (hADSCs), bone marrow (hBMSCs), and umbilical cord Wharton’s jelly (hWJSCs). hMSC secretomes were obtained under xenofree conditions and analyzed by liquid chromatography tandem mass spectrometry (LC/MS-MS). Biological processes related to angiogenesis were found to be enriched in the proteomic profile of hMSC secretomes. hWJSC secretomes revealed a more complete angiogenic network with higher concentrations of angiogenesis related proteins, followed by hBMSC secretomes. hADSC secretomes lacked central angiogenic proteins and expressed most detected proteins to a significantly lower level. In vivo all secretomes induced vascularization of subcutaneously implanted Matrigel plugs in mice. Differences in secretome composition were functionally analyzed with monocyte and endothelial cell (EC) in vitro co-culture experiments using vi-SNE based multidimensional flow cytometry data analysis. Functional responses between hBMSC and hWJSC secretomes were comparable, with significantly higher migration of CD14++ CD16− monocytes and enhanced macrophage differentiation compared with hADSC secretomes. Both secretomes also induced a more profound pro-angiogenic phenotype of ECs. These results suggest hWJSCs secretome as the most potent hMSC source for inflammation-mediated angiogenesis induction, while the potency of hADSC secretomes was lowest. This systematic analysis may have implication on the selection of hMSCs for future clinical studies.

Platelet-rich fibrin secretome induces three dimensional angiogenic activation in vitro.

Different tissue engineering techniques are used to support rapid vascularisation. A novel technique is the use of platelet-rich fibrin (PRF), an autologous source of growth factors. This study was the first to investigate the influence of PRF matrices, isolated following different centrifugation protocols, on human dermal vascular endothelial cells (ECs) in mono-culture and co-culture with human primary fibroblasts (HFs) as an in vitro model for tissue regeneration. Focus was placed on vascular structure formation and growth factor release. HFs and ECs were cultivated with PRF prepared using a high (710 ×g) or low (44 ×g) relative centrifugation force (RCF) over 14 d. Immunofluorescence staining and immunohistochemistry were used to evaluate the microvascular formation. Cell culture supernatants were collected for evaluation of growth factor release. The results showed a PRF-mediated effect on the induction of angiogenesis in ECs. Microvessel-like structure formation was promoted when ECs were combined with low-RCF PRF as compared to high-RCF PRF or control group. The percentage of vascular lumen area was significantly higher in low-RCF PRF, especially at day 7, which coincided with statistically significantly higher growth factor [vascular endothelial factor (VEGF), transforming growth factor β1 (TGF-β1) and platelet derived growth factor (PDGF)] concentration measured in low-RCF PRF as compared to high-RCF PRF or control group. In conclusion, reducing the RCF according to the low-speed centrifugation concept (LSCC) resulted in increased growth factor release and angiogenic structure formation with EC mono-culture, suggesting that PRF may be a highly beneficial therapeutic tool for tissue engineering applications.

Adjustable Depth Fractional Radiofrequency Combined With Bipolar Radiofrequency: A Minimally Invasive Combination Treatment for Skin Laxity.

Increasingly, patients are seeking minimally invasive methods to tighten skin and remodel adipose tissue. A large treatment gap exists among 3 types of patients: (1) the younger demographic, who increasingly desire soft tissue tightening without traditional operations, scars, and downtime; (2) patients with soft tissue laxity who are not “severe enough” to justify an excisional procedure, but not “mild enough” to rely on liposuction with soft tissue contraction alone; and (3) those with recurrent laxity who already underwent traditional excisional procedures. In these populations, plastic surgeons risk under- or overtreating with traditional methods. The purpose of this supplement is to describe the utility of radiofrequency (RF) microneedling (Fractora modified to Morpheus8 InMode Aesthetic Solutions, Lake Forest, CA) in combination with bipolar RF (FaceTite/BodyTite, InMode Aesthetic Solutions). By combining these procedures, the aforementioned treatment gap can be addressed. The RF microneedling allows for subdermal adipose remodeling and skin tightening. Addition of bipolar RF also tightens the skin by contraction of the underlaying fibroseptal network in addition to induction of neocollagenesis, elastogenesis, and angiogenesis at skin surface temperatures of 40° to 50°C. In our experience, these technologies have been effective and safe in these patient populations.Level of Evidence: 4

Induction of Angiogenesis by Malarial Infection through Hypoxia Dependent Manner.

Malarial infection induces tissue hypoxia in the host through destruction of red blood cells. Tissue hypoxia in malarial infection may increase the activity of HIF1α through an intracellular oxygen-sensing pathway. Activation of HIF1α may also induce vascular endothelial growth factor (VEGF) to trigger angiogenesis. To investigate whether malarial infection actually generates hypoxia-induced angiogenesis, we analyzed severity of hypoxia, the expression of hypoxia-related angiogenic factors, and numbers of blood vessels in various tissues infected with Plasmodium berghei. Infection in mice was performed by intraperitoneal injection of 2×106 parasitized red blood cells. After infection, we studied parasitemia and survival. We analyzed hypoxia, numbers of blood vessels, and expression of hypoxia-related angiogenic factors including VEGF and HIF1α. We used Western blot, immunofluorescence, and immunohistochemistry to analyze various tissues from Plasmodium berghei-infected mice. In malaria-infected mice, parasitemia was increased over the duration of infection and directly associated with mortality rate. Expression of VEGF and HIF1α increased with the parasitemia in various tissues. Additionally, numbers of blood vessels significantly increased in each tissue type of the malaria-infected group compared to the uninfected control group. These results suggest that malarial infection in mice activates hypoxia-induced angiogenesis by stimulation of HIF1α and VEGF in various tissues.

Natural Killer Cells as Key Players of Tumor Progression and Angiogenesis: Old and Novel Tools to Divert Their Pro-Tumor Activities into Potent Anti-Tumor Effects.

Immune cells, as a consequence of their plasticity, can acquire altered phenotype/functions within the tumor microenvironment (TME). Some of these aberrant functions include attenuation of targeting and killing of tumor cells, tolerogenic/immunosuppressive behavior and acquisition of pro-angiogenic activities. Natural killer (NK) cells are effector lymphocytes involved in tumor immunosurveillance. In solid malignancies, tumor-associated NK cells (TANK cells) in peripheral blood and tumor-infiltrating NK (TINK) cells show altered phenotypes and are characterized by either anergy or reduced cytotoxicity. Here, we aim at discussing how NK cells can support tumor progression and how induction of angiogenesis, due to TME stimuli, can be a relevant part on the NK cell-associated tumor supporting activities. We will review and discuss the contribution of the TME in shaping NK cell response favoring cancer progression. We will focus on TME-derived set of factors such as TGF-β, soluble HLA-G, prostaglandin E2, adenosine, extracellular vesicles, and miRNAs, which can exhibit a dual function. On one hand, these factors can suppress NK cell-mediated activities but, on the other hand, they can induce a pro-angiogenic polarization in NK cells. Also, we will analyze the impact on cancer progression of the interaction of NK cells with several TME-associated cells, including macrophages, neutrophils, mast cells, cancer-associated fibroblasts, and endothelial cells. Then, we will discuss the most relevant therapeutic approaches aimed at potentiating/restoring NK cell activities against tumors. Finally, supported by the literature revision and our new findings on NK cell pro-angiogenic activities, we uphold NK cells to a key host cellular paradigm in controlling tumor progression and angiogenesis; thus, we should bear in mind NK cells like a TME-associated target for anti-tumor therapeutic approaches.

SDF1/CXCR7 Signaling Axis Participates in Angiogenesis in Degenerated Discs via the PI3K/AKT Pathway.

Degenerative disc disease (DDD) is the main cause of low back pain, and the ingrowth of new blood vessels is one of its pathological features. The stromal cell-derived factor 1 (SDF1)/CXCR7 signaling axis plays a role in these physiological and pathological activities. The aims of this study were to explore whether this signaling axis participates in the angiogenesis of degenerated intervertebral discs (IVDs) and to define its underlying mechanism. In this study, we cocultured human nucleus pulposus cells (NPCs) and vascular endothelial cells (VECs) and regulated the expression of SDF1/CXCR7 to investigate the effect of VEC angiogenesis by NPCs. The results revealed that angiogenesis was enhanced with increased SDF1 and that angiogenesis was weakened with the inhibition of CXCR7. We found that PI3K/AKT was involved in the downstream pathway in the coculture. VEC angiogenesis induction by NPCs was enhanced with an increase in pAKT or a decrease in PTEN. We conclude that the SDF1/CXCR7 signaling axis plays a role in the angiogenesis of degenerated IVD through the PI3K/AKT pathway.

P53 plays a crucial role in endothelial dysfunction associated with hyperglycemia and ischemia

p53 is a guardian of the genome that protects against carcinogenesis. There is accumulating evidence that p53 is activated with aging. Such activation has been reported to contribute to various age-associated pathologies, but its role in vascular dysfunction is largely unknown. The aim of this study was to investigate whether activation of endothelial p53 has a pathological effect in relation to endothelial function. We established endothelial p53 loss-of-function and gain-of-function models by breeding endothelial-cell specific Cre mice with floxed Trp53 or floxed Mdm2/Mdm4 mice, respectively. Then we induced diabetes by injection of streptozotocin. In the diabetic state, endothelial p53 expression was markedly up-regulated and endothelium-dependent vasodilatation was significantly impaired. Impairment of vasodilatation was significantly ameliorated in endothelial p53 knockout (EC-p53 KO) mice, and deletion of endothelial p53 also significantly enhanced the induction of angiogenesis by ischemia. Conversely, activation of endothelial p53 by deleting Mdm2/Mdm4 reduced both endothelium-dependent vasodilatation and ischemia-induced angiogenesis. Introduction of p53 into human endothelial cells up-regulated the expression of phosphatase and tensin homolog (PTEN), thereby reducing phospho-eNOS levels. Consistent with these results, the beneficial impact of endothelial p53 deletion on endothelial function was attenuated in EC-p53 KO mice with an eNOS-deficient background. These results show that endothelial p53 negatively regulates endothelium-dependent vasodilatation and ischemia-induced angiogenesis, suggesting that inhibition of endothelial p53 could be a novel therapeutic target in patients with metabolic disorders.

MiRNA-891a-5p mediates HIV-1 Tat and KSHV Orf-K1 synergistic induction of angiogenesis by activating NF-κB signaling.

Co-infection with HIV-1 and Kaposi's sarcoma-associated herpesvirus (KSHV) is the cause of aggressive AIDS-related Kaposi's sarcoma (AIDS-KS) characterized by abnormal angiogenesis. The impact of HIV-1 and KSHV interaction on the pathogenesis and extensive angiogenesis of AIDS-KS remains unclear. Here, we explored the synergistic effect of HIV-1 Tat and KSHV oncogene Orf-K1 on angiogenesis. Our results showed that soluble Tat or ectopic expression of Tat enhanced K1-induced cell proliferation, microtubule formation and angiogenesis in chorioallantoic membrane and nude mice models. Mechanistic studies revealed that Tat promoted K1-induced angiogenesis by enhancing NF-κB signaling. Mechanistically, we showed that Tat synergized with K1 to induce the expression of miR-891a-5p, which directly targeted IκBα 3′ untranslated region, leading to NF-κB activation. Consequently, inhibition of miR-891a-5p increased IκBα level, prevented nuclear translocation of NF-κB p65 and ultimately suppressed the synergistic effect of Tat- and K1-induced angiogenesis. Our results illustrate that, by targeting IκBα to activate the NF-κB pathway, miR-891a-5p mediates Tat and K1 synergistic induction of angiogenesis. Therefore, the miR-891a-5p/NF-κB pathway is important in the pathogenesis of AIDS-KS, which could be an attractive therapeutic target for AIDS-KS.

Ameliorative Effect of Cardamom Aqueous Extract on Doxorubicin-Induced Cardiotoxicity in Rats

This study was conducted to evaluate the potential cardioprotective effect of cardamom (CAR) against myocardial injuries induced by doxorubicin (DOX) in rats through investigation of histological alterations and the associated oxidative stress, apoptosis, inflammation, and angiogenesis. This study included 30 adult male albino rats that were randomized to 3 groups (n = 10/group): group I (control), group II (DOX) rats injected with DOX (2.5 mg/kg body weight [BW] i.p.) every other day for 2 weeks, and group III (CAR+DOX) received CAR extract (200 mg/kg BW) orally for 3 weeks, and 1 week later (starting from the 2nd week) they were injected with DOX (2.5 mg/kg BW i.p.) every other day for 2 weeks. Rats treated with DOX alone exhibited notable myocardial damage (discontinuity and disorganization of cardiac muscle fibers, mononuclear cell infiltration, and apparent increases in collagen fiber deposition) accompanied by loss of function (revealed by elevated serum levels of lactate dehydrogenase, creatine kinase, and cardiac troponin), induction of oxidative stress (indicated by higher levels of nitric oxide and malon­dialdehyde, and lower levels of superoxide dismutase, catalase, and glutathione peroxidase), apoptosis (evidenced by high caspase 3 activity and immunostaining), and inflammation (marked by high cardiac NFκB level). However, administration of CAR not only ameliorated all deleterious effects of DOX but also induced angiogenesis, as indicated by a significant increase in VEGF immunoreactivity. These data indicate that CAR could relieve DOX-induced cardiotoxicity, at least in part, via reductions in oxidative stress, apoptosis, and inflammation and increased tissue regeneration via induction of angiogenesis. Therefore, CAR could be a promising cytoprotective agent against DOX cardiotoxicity.

Vascular endothelial growth factor biology for regenerative angiogenesis.

Despite major advances in medical, catheter-based or surgical treatment, cardiovascular diseases such as peripheral artery disease and coronary artery disease still cause significant morbidity and mortality. Furthermore, many patients do not qualify for catheter-based treatment or bypass surgery because of advanced disease or surgical risk. There is therefore an urgent need for novel treatment strategies. Therapeutic angiogenesis aims to restore blood flow to ischaemic tissue by stimulating the growth of new blood vessels through the local delivery of angiogenic factors, and may thus be an attractive treatment alternative for these patients. Angiogenesis is a complex process and the growth of normal, stable and functional vasculature depends on the coordinated interplay of different cell types and growth factors. Vascular endothelial growth factor-A (VEGF) is the fundamental regulator of vascular growth and the key target of therapeutic angiogenesis approaches. However, first-generation clinical trials of VEGF gene therapy have been disappointing, and a clear clinical benefit has yet to be established. In particular, VEGF delivery (a) appears to have a very limited therapeutic window in vivo: low doses are safe but mostly inefficient, whereas higher doses become rapidly unsafe; and (b) requires a sustained expression in vivo of at least about four weeks to achieve stable vessels that persist after cessation of the angiogenic stimulus. Here we will review the current understanding of how VEGF induces the growth of normal or pathological blood vessels, what limitations for the controlled induction of safe and efficient angiogenesis are intrinsically linked to the biological properties of VEGF, and how this knowledge can guide the design of more effective strategies for therapeutic angiogenesis.

Reduction in Vasa Vasorum Angiogenesis by Lp-PLA2 Selective Inhibitor Through The HIF-1α and VEGF Expression Under Dyslipidemic Conditions in Atherosclerosis Pathogenesis.

Atherosclerosis is a chronic inflammatory disease which may lead to major cardiovascular events. The primary cause of atherosclerosis is Dyslipidemia. The increased level of lipid profile triggers endothelial dysfunction. This results in inflammation with the recruitment of monocyte, macrophage, T lymphocyte, and Mast cells secreted by an Lp-PLA2 enzyme which causes binding between macrophage and oxidized LDL. This binding results in the formation of foam cells and also the migration of smooth muscle cells. Following that, an Lp-PLA2 receptor hydrolizes OxPC which results in LysoPC and OxNEFA, bioactive compounds which stimulate the progression of atherosclerosis plaques. This process leads to cell hypoxia, which may result in the increase of HIF-1α and VEGF expressions and induction of vasa vasorum angiogenesis. Employing darapladib as an agent of Lp-PLA2 selective inhibitors, this study aimed to find out the effect of darapladib as an Lp- PLA2 selective inhibitor agent on the formation of vasa vasorum angiogenesis and the decrease of HIF-1α and VEGF expression in aortic tissue of rats with dyslipidemia. A true laboratory experiment with a randomized post-test control group design used 30 male spraque dowley rats as animal models which were divided into 6 groups: Normal 8 weeks, Normal 16 weeks, Dyslipidemia (DL) 8 weeks, Dyslipidemia (DL) 16 weeks, Dyslipidemia with darapladib treatment (DLDP) 8 weeks and Dyslipidemia with darapladib treatment (DLDP) 16 weeks. The data measured in this study were the lipid profile (total cholesterol, HDL, and LDL). Using EnzyChrom TM kit, hematoxylin eosin, and double-labelling immunofluorescene, the levels of lipid profile, vasa vasorum, HIF-1α and VEGF were measured. The study results which were analyzed using NOVA test showed that with darapladib administration, there was a significant decrease in vasa vasorum angiogenesis (p=0.000), HIF-1α (p=0.005) and VEGF (p=0.009) expression in each time series. This result proves that Lp-PLA2 inhibitor reduces inflammatory process. Darapladib injection as an Lp-PLA2 selective inhibitor correlates with the decreasing vasa vasorum angiogenesis through alteration in HIF-1α and VEGF expressions in the aorta of high fat diet rats. We recommend further experiments to determine the effectiveness of darapladib with earlier time series in the atherosclerosis process.