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Sample records for progenitor cell-induced neovascularization

  1. Cathepsin L is required for endothelial progenitor cell-induced neovascularization

    SciTech Connect

    Urbich, Carmen; Heeschen, Christopher; Aicher, Alexandra; Sasaki, Ken-ichiro; Bruhl, Thomas; Hofmann, Wolf K.; Peters, Christoph; Reinheckel, Thomas; Pennacchio, Len A.; Abolmaali, Nasreddin D.; Chavakis, Emmanouil; Zeiher, Andreas M.; Dimmeler, Stefanie

    2004-01-15

    Infusion of endothelial progenitor cells (EPCs), but not of mature endothelial cells (ECs), promotes neovascularization after ischemia. We performed a gene expression profiling of EPCs and ECs to identify genes, which might be important for the neovascularization capacity of EPCs. Intriguingly, the protease cathepsin L (CathL) was highly expressed in EPCs as opposed to ECs and is essential for matrix degradation and invasion by EPCs in vitro. CathL deficient mice showed impaired functional recovery after hind limb ischemia supporting the concept for an important role of CathL in postnatal neovascularization. Infused CathL deficient progenitor cells failed to home to sites of ischemia and to augment neovascularization. In contrast, over expression of CathL in mature ECs significantly enhanced their invasive activity and induced their neovascularization capacity in vivo. Taken together, CathL plays a crucial role for the integration of circulating EPCs into the ischemic tissue and is required for neovascularization mediated by EPCs.

  2. Smooth muscle progenitor cells from peripheral blood promote the neovascularization of endothelial colony-forming cells

    SciTech Connect

    Joo, Hyung Joon; Seo, Ha-Rim; Jeong, Hyo Eun; Choi, Seung-Cheol; Park, Jae Hyung; Yu, Cheol Woong; Hong, Soon Jun; Chung, Seok; Lim, Do-Sun

    2014-07-11

    Highlights: • Two distinct vascular progenitor cells are induced from adult peripheral blood. • ECFCs induce vascular structures in vitro and in vivo. • SMPCs augment the in vitro and in vivo angiogenic potential of ECFCs. • Both cell types have synergistic therapeutic potential in ischemic hindlimb model. - Abstract: Proangiogenic cell therapy using autologous progenitors is a promising strategy for treating ischemic disease. Considering that neovascularization is a harmonized cellular process that involves both endothelial cells and vascular smooth muscle cells, peripheral blood-originating endothelial colony-forming cells (ECFCs) and smooth muscle progenitor cells (SMPCs), which are similar to mature endothelial cells and vascular smooth muscle cells, could be attractive cellular candidates to achieve therapeutic neovascularization. We successfully induced populations of two different vascular progenitor cells (ECFCs and SMPCs) from adult peripheral blood. Both progenitor cell types expressed endothelial-specific or smooth muscle-specific genes and markers, respectively. In a protein array focused on angiogenic cytokines, SMPCs demonstrated significantly higher expression of bFGF, EGF, TIMP2, ENA78, and TIMP1 compared to ECFCs. Conditioned medium from SMPCs and co-culture with SMPCs revealed that SMPCs promoted cell proliferation, migration, and the in vitro angiogenesis of ECFCs. Finally, co-transplantation of ECFCs and SMPCs induced robust in vivo neovascularization, as well as improved blood perfusion and tissue repair, in a mouse ischemic hindlimb model. Taken together, we have provided the first evidence of a cell therapy strategy for therapeutic neovascularization using two different types of autologous progenitors (ECFCs and SMPCs) derived from adult peripheral blood.

  3. Amlodipine Ameliorates Ischemia-Induced Neovascularization in Diabetic Rats through Endothelial Progenitor Cell Mobilization.

    PubMed

    Sun, Jiayin; Xie, Jun; Kang, Lina; Ferro, Albert; Dong, Li; Xu, Biao

    2016-01-01

    Objectives. We investigated whether amlodipine could improve angiogenic responses in a diabetic rat model of acute myocardial infarction (AMI) through improving bone marrow endothelial progenitor cell (EPC) mobilization, in the same way as angiotensin converting enzyme inhibitors. Methods. After induction of AMI by coronary artery ligation, diabetic rats were randomly assigned to receive perindopril (2 mgkg(-1) day(-1)), amlodipine (2.5 mgkg(-1) day(-1)), or vehicle by gavage (n = 20 per group). Circulating EPC counts before ligation and on days 1, 3, 5, 7, 14, and 28 after AMI were measured in each group. Microvessel density, cardiac function, and cardiac remodeling were assessed 4 weeks after treatment. The signaling pathway related to EPC mobilization was also measured. Results. Circulating EPC count in amlodipine- and perindopril-treated rats peaked at day 7, to an obvious higher level than the control group peak which was reached earlier (at day 5). Rats treated with amlodipine showed improved postischemia neovascularization and cardiac function, together with reduced cardiac remodeling, decreased interstitial fibrosis, and cardiomyocyte apoptosis. Amlodipine treatment also increased cardiac SDF-1/CXCR4 expression and gave rise to activation of VEGF/Akt/eNOS signaling in bone marrow. Conclusions. Amlodipine promotes neovascularization by improving EPC mobilization from bone marrow in diabetic rats after AMI, and activation of VEGF/Akt/eNOS signaling may in part contribute to this. PMID:27243031

  4. Amlodipine Ameliorates Ischemia-Induced Neovascularization in Diabetic Rats through Endothelial Progenitor Cell Mobilization

    PubMed Central

    Sun, Jiayin; Xie, Jun; Kang, Lina; Ferro, Albert; Dong, Li; Xu, Biao

    2016-01-01

    Objectives. We investigated whether amlodipine could improve angiogenic responses in a diabetic rat model of acute myocardial infarction (AMI) through improving bone marrow endothelial progenitor cell (EPC) mobilization, in the same way as angiotensin converting enzyme inhibitors. Methods. After induction of AMI by coronary artery ligation, diabetic rats were randomly assigned to receive perindopril (2 mgkg−1 day−1), amlodipine (2.5 mgkg−1 day−1), or vehicle by gavage (n = 20 per group). Circulating EPC counts before ligation and on days 1, 3, 5, 7, 14, and 28 after AMI were measured in each group. Microvessel density, cardiac function, and cardiac remodeling were assessed 4 weeks after treatment. The signaling pathway related to EPC mobilization was also measured. Results. Circulating EPC count in amlodipine- and perindopril-treated rats peaked at day 7, to an obvious higher level than the control group peak which was reached earlier (at day 5). Rats treated with amlodipine showed improved postischemia neovascularization and cardiac function, together with reduced cardiac remodeling, decreased interstitial fibrosis, and cardiomyocyte apoptosis. Amlodipine treatment also increased cardiac SDF-1/CXCR4 expression and gave rise to activation of VEGF/Akt/eNOS signaling in bone marrow. Conclusions. Amlodipine promotes neovascularization by improving EPC mobilization from bone marrow in diabetic rats after AMI, and activation of VEGF/Akt/eNOS signaling may in part contribute to this. PMID:27243031

  5. Zoledronate Inhibits Ischemia-Induced Neovascularization by Impairing the Mobilization and Function of Endothelial Progenitor Cells

    PubMed Central

    Tsai, Shih-Hung; Huang, Po-Hsun; Chang, Wei-Chou; Tsai, Hsiao-Ya; Lin, Chih-Pei; Leu, Hsin-Bang; Wu, Tao-Cheng; Chen, Jaw-Wen; Lin, Shing-Jong

    2012-01-01

    Background Bisphosphonates are a class of pharmacologic compounds that are commonly used to treat postmenopausal osteoporosis and malignant osteolytic processes. Studies have shown that bone marrow-derived endothelial progenitor cells (EPCs) play a significant role in postnatal neovascularization. Whether the nitrogen-containing bisphosphonate zoledronate inhibits ischemia-induced neovascularization by modulating EPC functions remains unclear. Methodology/Principal Findings Unilateral hindlimb ischemia was surgically induced in wild-type mice after 2 weeks of treatment with vehicle or zoledronate (low-dose: 30 μg/kg; high-dose: 100 μg/kg). Doppler perfusion imaging demonstrated that the ischemic limb/normal side blood perfusion ratio was significantly lower in wild-type mice treated with low-dose zoledronate and in mice treated with high-dose zoledronate than in controls 4 weeks after ischemic surgery (control vs. low-dose vs. high-dose: 87±7% vs. *61±18% vs. **49±17%, *p<0.01, **p<0.005 compared to control). Capillary densities were also significantly lower in mice treated with low-dose zoledronate and in mice treated with high-dose zoledronate than in control mice. Flow cytometry analysis showed impaired mobilization of EPC-like cells (Sca-1+/Flk-1+) after surgical induction of ischemia in mice treated with zoledronate but normal levels of mobilization in mice treated with vehicle. In addition, ischemic tissue from mice that received zoledronate treatment exhibited significantly lower levels of the active form of MMP-9, lower levels of VEGF, and lower levels of phosphorylated eNOS and phosphorylated Akt than ischemic tissue from mice that received vehicle. Results of the in vitro studies showed that incubation with zoledronate inhibited the viability, migration, and tube-forming capacities of EPC. Conclusions/Significance Zoledronate inhibited ischemia-induced neovascularization by impairing EPC mobilization and angiogenic functions. These findings suggest

  6. CD34/CD133 enriched bone marrow progenitor cells promote neovascularization of tissue engineered constructs in vivo.

    PubMed

    Herrmann, Marietta; Binder, Andreas; Menzel, Ursula; Zeiter, Stephan; Alini, Mauro; Verrier, Sophie

    2014-11-01

    Vascularization is critical for 3D tissue engineered constructs. In large size implants the ingrowth of vessels often fails. The purpose of this study was to identify an easily accessible, clinically relevant cell source able to promote neovascularization in engineered implants in vivo and to establish an autologous culture method for these cells. MSCs (mesenchymal stem cells) and an endothelial progenitor containing cell (EPCC) population were obtained from human bone marrow aspirates. The expression of endothelial-markers, uptake of acetylated low density lipoprotein (acLDL) and tube-like structure formation capability of EPCCs were analyzed after expansion in endothelial growth medium or medium supplemented with autologous platelet lysate (PL). EPCCs were co-seeded with MSCs on hydroxyapatite-containing polyurethane scaffolds and then implanted subcutaneously in nude mice. Human EPCCs displayed typical characteristics of endothelial cells including uptake of acLDL and formation of tube-like structures on Matrigel™. In vivo, EPCCs cultured with PL triggered neovascularization. MSC/EPCC interactions promoted the maturation of newly formed luminal structures, which were detected deep within the scaffold and partly perfused, demonstrating a connection with the host vascular system. We demonstrate that this population of cells, isolated in a clinically relevant manner and cultured with autologous growth factors readily promoted neovascularization in tissue engineered constructs in vivo enabling a potential translation into the clinic. PMID:25460607

  7. Adipose-Derived Stem Cell-Seeded Hydrogels Increase Endogenous Progenitor Cell Recruitment and Neovascularization in Wounds.

    PubMed

    Kosaraju, Revanth; Rennert, Robert C; Maan, Zeshaan N; Duscher, Dominik; Barrera, Janos; Whittam, Alexander J; Januszyk, Michael; Rajadas, Jayakumar; Rodrigues, Melanie; Gurtner, Geoffrey C

    2016-02-01

    Adipose-derived mesenchymal stem cells (ASCs) are appealing for cell-based wound therapies because of their accessibility and ease of harvest, but their utility is limited by poor cell survival within the harsh wound microenvironment. In prior work, our laboratory has demonstrated that seeding ASCs within a soft pullulan-collagen hydrogel enhances ASC survival and improves wound healing. To more fully understand the mechanism of this therapy, we examined whether ASC-seeded hydrogels were able to modulate the recruitment and/or functionality of endogenous progenitor cells. Employing a parabiosis model and fluorescence-activated cell sorting analysis, we demonstrate that application of ASC-seeded hydrogels to wounds, when compared with injected ASCs or a noncell control, increased the recruitment of provascular circulating bone marrow-derived mesenchymal progenitor cells (BM-MPCs). BM-MPCs comprised 23.0% of recruited circulating progenitor cells in wounds treated with ASC-seeded hydrogels versus 8.4% and 2.1% in those treated with controls, p < 0.05. Exploring the potential for functional modulation of BM-MPCs, we demonstrate a statistically significant increase in BM-MPC migration, proliferation, and tubulization when exposed to hydrogel-seeded ASC-conditioned medium versus control ASC-conditioned medium (73.8% vs. 51.4% scratch assay closure; 9.1% vs. 1.4% proliferation rate; 10.2 vs. 5.5 tubules/HPF; p < 0.05 for all assays). BM-MPC expression of genes related to cell stemness and angiogenesis was also significantly increased following exposure to hydrogel-seeded ASC-conditioned medium (p < 0.05). These data suggest that ASC-seeded hydrogels improve both progenitor cell recruitment and functionality to effect greater neovascularization. PMID:26871860

  8. Statins, HMG-CoA Reductase Inhibitors, Improve Neovascularization by Increasing the Expression Density of CXCR4 in Endothelial Progenitor Cells

    PubMed Central

    Chiang, Kuang-Hsing; Cheng, Wan-Li; Shih, Chun-Ming; Lin, Yi-Wen; Tsao, Nai-Wen; Kao, Yung-Ta; Lin, Chih-Ting; Wu, Shinn-Chih; Huang, Chun-Yao; Lin, Feng-Yen

    2015-01-01

    Statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, are used to reduce cholesterol biosynthesis in the liver. Accordingly, statins regulate nitric oxide (NO) and glutamate metabolism, inflammation, angiogenesis, immunity and endothelial progenitor cells (EPCs) functions. The function of EPCs are regulated by stromal cell-derived factor 1 (SDF-1), vascular endothelial growth factor (VEGF), and transforming growth factor β (TGF-β), etc. Even though the pharmacologic mechanisms by which statins affect the neovasculogenesis of circulating EPCs, it is still unknown whether statins affect the EPCs function through the regulation of CXCR4, a SDF-1 receptor expression. Therefore, we desired to explore the effects of statins on CXCR4 expression in EPC-mediated neovascularization by in vitro and in vivo analyses. In animal studies, we analyzed the effects of atorvastatin or rosuvastatin treatments in recovery of capillary density and blood flow, the expression of vWF and CXCR4 at ischemia sites in hindlimb ischemia ICR mice. Additionally, we analyzed whether the atorvastatin or rosuvastatin treatments increased the mobilization, homing, and CXCR4 expression of EPCs in hindlimb ischemia ICR mice that underwent bone marrow transplantation. The results indicated that statins treatment led to significantly more CXCR4-positive endothelial progenitor cells incorporated into ischemic sites and in the blood compared with control mice. In vivo, we isolated human EPCs and analyzed the effect of statins treatment on the vasculogenic ability of EPCs and the expression of CXCR4. Compared with the control groups, the neovascularization ability of EPCs was significantly improved in the atorvastatin or rosuvastatin group; this improvement was dependent on CXCR4 up-regulation. The efficacy of statins on improving EPC neovascularization was related to the SDF-1α/CXCR4 axis and might be regulated by the NO. In conclusion, atorvastatin and rosuvastatin improved

  9. A Case of Abnormal Lymphatic-Like Differentiation and Endothelial Progenitor Cell Activation in Neovascularization Associated with Hemi-Retinal Vein Occlusion

    PubMed Central

    Loukovaara, Sirpa; Gucciardo, Erika; Repo, Pauliina; Lohi, Jouko; Salven, Petri; Lehti, Kaisa

    2015-01-01

    Purpose Pathological vascular differentiation in retinal vein occlusion (RVO)-related neovessel formation remains poorly characterized. The role of intraocular lymphatic-like differentiation or endothelial progenitor cell activity has not been studied in this disease. Methods Vitrectomy was performed in an eye with hemi-RVO; the neovessel membrane located at the optic nerve head was removed and subjected to immunohistochemistry. Characterization of the neovascular tissue was performed using hematoxylin and eosin, α-smooth muscle actin, and the pan-endothelial cell (EC) adhesion molecule CD31. The expression of lymphatic EC markers was studied by lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), podoplanin (PDPN), and prospero-related homeobox protein 1 (Prox-1). Potential vascular stem/progenitor cells were identified by active cellular proliferation (Ki67) and expression of the stem cell marker CD117. Results The specimen contained blood vessels lined by ECs and surrounded by pericytes. Immunoreactivity for LYVE-1 and Prox-1 was detected, with Prox-1 being more widely expressed in the active Ki67-positive lumen-lining cells. PDPN expression was instead found in the cells residing in the extravascular tissue. Expression of the stem cell markers CD117 and Ki67 suggested vascular endothelial progenitor cell activity. Conclusions Intraocular lymphatic-like differentiation coupled with progenitor cell activation may be involved in the pathology of neovessel formation in ischemia-induced human hemi-RVO. PMID:26327908

  10. Diffusible Factors Secreted by Glioblastoma and Medulloblastoma Cells Induce Oxidative Stress in Bystander Neural Stem Progenitors

    PubMed Central

    Sharma, Neha; Colangelo, Nicholas W.; de Toledo, Sonia M.

    2016-01-01

    Harmful effects that alter the homeostasis of neural stem or progenitor cells (NSPs) can affect regenerative processes in the central nervous system. We investigated the effect of soluble factors secreted by control or 137Cs-γ-irradiated glioblastoma or medulloblastoma cells on redox-modulated endpoints in recipient human NSPs. Growth medium harvested from the nonirradiated brain tumor cells, following 24 h of growth, induced prominent oxidative stress in recipient NSPs as judged by overall increases in mitochondrial superoxide radical levels (p < .001), activation of c-jun N-terminal kinase, and decrease in the active form of FoxO3a. The induced oxidative stress was associated with phosphorylation of p53 on serine 15, a marker of DNA damage, induction of the cyclin-cyclin dependent kinase inhibitors p21Waf1 and p27Kip1, and perturbations in cell cycle progression (p < .001). These changes were also associated with increased apoptosis as determined by enhanced annexin V staining (p < .001) and caspase 8 activation (p < .05) and altered expression of critical regulators of self-renewal, proliferation, and differentiation. Exposure of the tumor cells to radiation only slightly altered the induced oxidative changes in the bystander NSPs, except for medium from irradiated medulloblastoma cells that was more potent at inducing apoptosis in the NSPs than medium from nonirradiated cells (p < .001). The elucidation of such stressful bystander effects provides avenues to understand the biochemical events underlying the development or exacerbation of degenerative outcomes associated with brain cancers. It is also relevant to tissue culture protocols whereby growth medium conditioned by tumor cells is often used to support the growth of stem cells. PMID:27511909

  11. Diffusible Factors Secreted by Glioblastoma and Medulloblastoma Cells Induce Oxidative Stress in Bystander Neural Stem Progenitors.

    PubMed

    Sharma, Neha; Colangelo, Nicholas W; de Toledo, Sonia M; Azzam, Edouard I

    2016-08-01

    Harmful effects that alter the homeostasis of neural stem or progenitor cells (NSPs) can affect regenerative processes in the central nervous system. We investigated the effect of soluble factors secreted by control or (137)Cs-γ-irradiated glioblastoma or medulloblastoma cells on redox-modulated endpoints in recipient human NSPs. Growth medium harvested from the nonirradiated brain tumor cells, following 24 h of growth, induced prominent oxidative stress in recipient NSPs as judged by overall increases in mitochondrial superoxide radical levels (p < .001), activation of c-jun N-terminal kinase, and decrease in the active form of FoxO3a. The induced oxidative stress was associated with phosphorylation of p53 on serine 15, a marker of DNA damage, induction of the cyclin-cyclin dependent kinase inhibitors p21(Waf1) and p27(Kip1), and perturbations in cell cycle progression (p < .001). These changes were also associated with increased apoptosis as determined by enhanced annexin V staining (p < .001) and caspase 8 activation (p < .05) and altered expression of critical regulators of self-renewal, proliferation, and differentiation. Exposure of the tumor cells to radiation only slightly altered the induced oxidative changes in the bystander NSPs, except for medium from irradiated medulloblastoma cells that was more potent at inducing apoptosis in the NSPs than medium from nonirradiated cells (p < .001). The elucidation of such stressful bystander effects provides avenues to understand the biochemical events underlying the development or exacerbation of degenerative outcomes associated with brain cancers. It is also relevant to tissue culture protocols whereby growth medium conditioned by tumor cells is often used to support the growth of stem cells. PMID:27511909

  12. SCF promotes dental pulp progenitor migration, neovascularization, and collagen remodeling - potential applications as a homing factor in dental pulp regeneration.

    PubMed

    Pan, Shuang; Dangaria, Smit; Gopinathan, Gokul; Yan, Xiulin; Lu, Xuanyu; Kolokythas, Antonia; Niu, Yumei; Luan, Xianghong

    2013-10-01

    Stem cell factor (SCF) is a powerful chemokine that binds to the c-Kit receptor CD117 and has shown promise as a homing agent capable of progenitor cell recruitment. In the present study we have documented high levels of both SCF and its receptor c-Kit in differentiating dental pulp (DP) cells and in the sub-odontoblastic layer of Höhl. In vitro studies using human DP progenitors revealed a significant increase in cell proliferation after100 nM SCF application, explained by a 2-fold upregulation in cyclin D3 and FGF2 cell cycle regulators, and a 7-fold increase in CDK4 expression. DP cell migration in the presence of SCF was up-regulated 2.7-fold after a 24 h culture period, and this effect was accompanied by cytoskeletal rearrangement, a 1.5-fold increase in polymeric F-actin over G-actin, and a 1.8-fold increase in RhoA expression. Explaining the signaling effect of SCF on DP migration, PI3K/Akt and MEK/ERK pathway inhibitors were demonstrated to significantly reduce DP cell migration, while SCF alone doubled the number of migrated cells. ERK and AKT phosphorylation were dramatically upregulated already 3-5 min after SCF addition to the culture medium and declined thereafter, classifying SCF as a fast acting chemokine. When applied as an agent to promote tissue regeneration in subcutaneously implanted collagen sponges, SCF resulted in a 7-fold increase in the cell number in the implanted tissue construct, a more than 9-fold increase in capillaries, as well as collagen sponge remodeling and collagen fiber neogenesis. Together, these studies demonstrate the suitability of SCF as a potent aid in the regeneration of dental pulp and other mesenchymal tissues, capable of inducing cell homing, angiogenesis, and tissue remodeling. PMID:23703692

  13. The GroEL protein of Porphyromonas gingivalis accelerates tumor growth by enhancing endothelial progenitor cell function and neovascularization.

    PubMed

    Lin, F-Y; Huang, C-Y; Lu, H-Y; Shih, C-M; Tsao, N-W; Shyue, S-K; Lin, C-Y; Chang, Y-J; Tsai, C-S; Lin, Y-W; Lin, S-J

    2015-06-01

    Porphyromonas gingivalis is a bacterial species that causes destruction of periodontal tissues. Additionally, previous evidence indicates that GroEL from P. gingivalis may possess biological activities involved in systemic inflammation, especially inflammation involved in the progression of periodontal diseases. The literature has established a relationship between periodontal disease and cancer. However, it is unclear whether P. gingivalis GroEL enhances tumor growth. Here, we investigated the effects of P. gingivalis GroEL on neovasculogenesis in C26 carcinoma cell-carrying BALB/c mice and chick eggs in vivo as well as its effect on human endothelial progenitor cells (EPC) in vitro. We found that GroEL treatment accelerated tumor growth (tumor volume and weight) and increased the mortality rate in C26 cell-carrying BALB/c mice. GroEL promoted neovasculogenesis in chicken embryonic allantois and increased the circulating EPC level in BALB/c mice. Furthermore, GroEL effectively stimulated EPC migration and tube formation and increased E-selectin expression, which is mediated by eNOS production and p38 mitogen-activated protein kinase activation. Additionally, GroEL may enhance resistance against paclitaxel-induced cell cytotoxicity and senescence in EPC. In conclusion, P. gingivalis GroEL may act as a potent virulence factor, contributing to the neovasculogenesis of tumor cells and resulting in accelerated tumor growth. PMID:25220060

  14. GroEL1, a Heat Shock protein 60 of Chlamydia pneumoniae, Impairs Neovascularization by Decreasing Endothelial Progenitor Cell Function

    PubMed Central

    Lin, Yi-Wen; Huang, Chun-Yao; Chen, Yung-Hsiang; Shih, Chun-Ming; Tsao, Nai-Wen; Lin, Cheng-Yen; Chang, Nen-Chung; Tsai, Chien-Sung; Tsai, Hsiao-Ya; Tsai, Jui-Chi; Huang, Po-Hsun; Li, Chi-Yuan; Lin, Feng-Yen

    2013-01-01

    The number and function of endothelial progenitor cells (EPCs) are sensitive to hyperglycemia, hypertension, and smoking in humans, which are also associated with the development of atherosclerosis. GroEL1 from Chlamydia pneumoniae has been found in atherosclerotic lesions and is related to atherosclerotic pathogenesis. However, the actual effects of GroEL1 on EPC function are unclear. In this study, we investigate the EPC function in GroEL1-administered hind limb-ischemic C57BL/B6 and C57BL/10ScNJ (a toll-like receptor 4 (TLR4) mutation) mice and human EPCs. In mice, laser Doppler imaging, flow cytometry, and immunohistochemistry were used to evaluate the degree of neo-vasculogenesis, circulating level of EPCs, and expression of CD34, vWF, and endothelial nitric oxide synthase (eNOS) in vessels. Blood flow in the ischemic limb was significantly impaired in C57BL/B6 but not C57BL/10ScNJ mice treated with GroEL1. Circulating EPCs were also decreased after GroEL1 administration in C57BL/B6 mice. Additionally, GroEL1 inhibited the expression of CD34 and eNOS in C57BL/B6 ischemic muscle. In vitro, GroEL1 impaired the capacity of differentiation, mobilization, tube formation, and migration of EPCs. GroEL1 increased senescence, which was mediated by caspases, p38 MAPK, and ERK1/2 signaling in EPCs. Furthermore, GroEL1 decreased integrin and E-selectin expression and induced inflammatory responses in EPCs. In conclusion, these findings suggest that TLR4 and impaired NO-related mechanisms could contribute to the reduced number and functional activity of EPCs in the presence of GroEL1 from C. pneumoniae. PMID:24376840

  15. Proliferation and differentiation of oligodendrocyte progenitor cells induced from rat embryonic neural precursor cells followed by flow cytometry.

    PubMed

    Lü, He-Zuo; Wang, Yan-Xia; Li, Ying; Fu, Sai-Li; Hang, Qin; Lu, Pei-Hua

    2008-08-01

    Previous studies have shown that a cell-intrinsic timer might determine when oligodendrocyte progenitor cells (OPCs) isolated from the central nervous system (CNS) stop dividing and initiate differentiation in a defined environment. In this report, the proliferation and differentiation of OPCs induced from neural precursor cells (NPCs) were analyzed by flow cytometry combined with carboxyfluorescein diacetate succinimidyl ester labeling and propidium iodide staining, respectively. When OPCs were cultured in OPC-medium, more than 30% of cells were in S- and G2/M-phases, and continuously self-renewed without differentiation. After exposure to thyroid hormone, there was an obvious decrease in the fraction of cells in both S- and G2/M-phases (<10%). Furthermore, the OPCs no longer proliferated, but differentiated into oligodendrocytes. The dynamic proliferation and differentiation characteristics of OPCs induced from NPCs and analyzed by flow cytometry were similar to those of OPCs isolated from the CNS and analyzed by other methods. These studies indicated that the proliferation and differentiation of OPCs can be followed simply and rapidly by flow cytometry. PMID:18473382

  16. High Calcium Bioglass Enhances Differentiation and Survival of Endothelial Progenitor Cells, Inducing Early Vascularization in Critical Size Bone Defects

    PubMed Central

    Nguyen Ngoc, Christina; Meier, Simon; Nau, Christoph; Schaible, Alexander; Marzi, Ingo; Henrich, Dirk

    2013-01-01

    Early vascularization is a prerequisite for successful bone healing and endothelial progenitor cells (EPC), seeded on appropriate biomaterials, can improve vascularization. The type of biomaterial influences EPC function with bioglass evoking a vascularizing response. In this study the influence of a composite biomaterial based on polylactic acid (PLA) and either 20 or 40% bioglass, BG20 and BG40, respectively, on the differentiation and survival of EPCs in vitro was investigated. Subsequently, the effect of the composite material on early vascularization in a rat calvarial critical size defect model with or without EPCs was evaluated. Human EPCs were cultured with β-TCP, PLA, BG20 or BG40, and seeding efficacy, cell viability, cell morphology and apoptosis were analysed in vitro. BG40 released the most calcium, and improved endothelial differentiation and vitality best. This effect was mimicked by adding an equivalent amount of calcium to the medium and was diminished in the presence of the calcium chelator, EGTA. To analyze the effect of BG40 and EPCs in vivo, a 6-mm diameter critical size calvarial defect was created in rats (n = 12). Controls (n = 6) received BG40 and the treatment group (n = 6) received BG40 seeded with 5×105 rat EPCs. Vascularization after 1 week was significantly improved when EPCs were seeded onto BG40, compared to implanting BG40 alone. This indicates that Ca2+ release improves EPC differentiation and is useful for enhanced early vascularization in critical size bone defects. PMID:24244419

  17. [Intraocular neovascularization].

    PubMed

    Inomata, H; Ishibashi, T; Murata, T; Iwasaki, M; Tahara, A; Hata, K; Yoshida, A; Yoshida, S; Onishi, Y; Murakami, M; Yamamoto, M; Kubota, T; Kawano, Y; Sugai, S; Sakamoto, T; Okada, T; Ishimoto, S; Fujisawa, K; Honda, T; Sakamoto, M; Shigefuji, M; Tsuji, I; Nishioka, K; Ueno, A; Nagatomi, Y

    1997-12-01

    To investigate the mechanism of intraocular neovascularization, we studied how vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) are expressed in the ocular tissues under hypoxic conditions. Prior to proliferation of vascular endothelial cells resulting in neovascularization, the retinal tissues such as pericytes, retinal glial cells, ganglion cells, and ciliary epithelium react directly to hypoxia expressing VEGF and/or IL-8 and stimulate endothelial cell proliferation in a paracrine manner. We demonstrated that transcription factor activator protein-1 (AP-1) is activated for expression of VEGF messenger ribonuculeic acid (mRNA) and in a similar way nuclear factor kappa B (NF-kappa B) is activated for expression of IL-8 mRNA. However, hypoxia-induced expression of VEGF and/ or IL-8 is only one aspect of the complicated processes in intraocular neovascularization. We hope that further detailed analysis of the mechanism will make it possible to inhibit and treat clinically intraocular neovascularization in the near future. PMID:9436356

  18. Irradiated human endothelial progenitor cells induce bystander killing in human non-small cell lung and pancreatic cancer cells.

    PubMed

    Turchan, William T; Shapiro, Ronald H; Sevigny, Garrett V; Chin-Sinex, Helen; Pruden, Benjamin; Mendonca, Marc S

    2016-08-01

    Purpose To investigate whether irradiated human endothelial progenitor cells (hEPC) could induce bystander killing in the A549 non-small cell lung cancer (NSCLC) cells and help explain the improved radiation-induced tumor cures observed in A549 tumor xenografts co-injected with hEPC. Materials and methods We investigated whether co-injection of CBM3 hEPC with A549 NSCLC cells would alter tumor xenograft growth rate or tumor cure after a single dose of 0 or 5 Gy of X-rays. We then utilized dual chamber Transwell dishes, to test whether medium from irradiated CBM3 and CBM4 hEPC would induce bystander cell killing in A549 cells, and as an additional control, in human pancreatic cancer MIA PaCa-2 cells. The CBM3 and CBM4 hEPC were plated into the upper Transwell chamber and the A549 or MIA PaCa-2 cells were plated in the lower Transwell chamber. The top inserts with the CBM3 or CBM4 hEPC cells were subsequently removed, irradiated, and then placed back into the Transwell dish for 3 h to allow for diffusion of any potential bystander factors from the irradiated hEPC in the upper chamber through the permeable membrane to the unirradiated cancer cells in the lower chamber. After the 3 h incubation, the cancer cells were re-plated for clonogenic survival. Results We found that co-injection of CBM3 hEPC with A549 NSCLC cells significantly increased the tumor growth rate compared to A549 cells alone, but paradoxically also increased A549 tumor cure after a single dose of 5 Gy of X-rays (p < 0.05). We hypothesized that irradiated hEPC may be inducing bystander killing in the A549 NSCLC cells in tumor xenografts, thus improving tumor cure. Bystander studies clearly showed that exposure to the medium from irradiated CBM3 and CBM4 hEPC induced significant bystander killing and decreased the surviving fraction of A549 and MIA PaCa-2 cells to 0.46 (46%) ± 0.22 and 0.74 ± 0.07 (74%) respectively (p < 0.005, p < 0.0001). In addition, antibody depletion

  19. SCF promotes dental pulp progenitor migration, neovascularization, and collagen remodeling – potential applications as a homing factor in dental pulp regeneration

    PubMed Central

    Pan, Shuang; Dangaria, Smit; Gopinathan, Gokul; Yan, Xiulin; Lu, Xuanyu; Kolokythas, Antonia; Niu, Yumei; Luan, Xianghong

    2014-01-01

    Stem cell factor (SCF) is a powerful chemokine that binds to the c-Kit receptor CD117 and has shown promise as a homing agent capable of progenitor cell recruitment. In the present study we have documented high levels of both SCF and its receptor c-Kit in differentiating dental pulp (DP) cells and in the sub-odontoblastic layer of Höhl. In vitro studies using human DP progenitors revealed a significant increase in cell proliferation after100nM SCF application, explained by a 2-fold upregulation in cyclin D3 and FGF2 cell cycle regulators, and a 7-fold increase in CDK4 expression. DP cell migration in the presence of SCF was up-regulated 2.7-fold after a 24 hour culture period, and this effect was accompanied by cytoskeletal rearrangement, a 1.5-fold increase in polymeric F-actin over G-actin, and a 1.8-fold increase in RhoA expression. Explaining the signaling effect of SCF on DP migration, PI3K/Akt and MEK/ERK pathway inhibitors were demonstrated to significantly reduce DP cell migration, while SCF alone doubled the number of migrated cells. ERK and AKT phosphorylation were dramatically upregulated already 3-5 minutes after SCF addition to the culture medium and declined thereafter, classifying SCF as a fast acting chemokine. When applied as an agent to promote tissue regeneration in subcutaneously implanted collagen sponges, SCF resulted in a 7-fold increase in the cell number in the implanted tissue construct, a more than 9-fold increase in capillaries, as well as collagen sponge remodeling and collagen fiber neogenesis. Together, these studies demonstrate the suitability of SCF as a potent aid in the regeneration of dental pulp and other mesenchymal tissues, capable of inducing cell homing, angiogenesis, and tissue remodeling. PMID:23703692

  20. HPMA copolymer-based combination therapy toxic to both prostate cancer stem/progenitor cells and differentiated cells induces durable anti-tumor effects

    PubMed Central

    Zhou, Yan; Yang, Jiyuan; Rhim, Johng S.; Kopeček, Jindřich

    2013-01-01

    Current treatments for prostate cancer are still not satisfactory, often resulting in tumor regrowth and metastasis. One of the main reasons for the ineffective anti-prostate cancer treatments is the failure to deplete cancer stem-like cells (CSCs) - a subset of cancer cells with enhanced tumorigenic capacity. Thus, combination of agents against both CSCs and bulk tumor cells may offer better therapeutic benefits. Several molecules with anti-cancer stem/progenitor cell activities have been under preclinical evaluations. However, their low solubility and nonspecific toxicity limit their clinical translation. Herein, we designed a combination macromolecular therapy containing two drug conjugates: HPMA copolymer-cyclopamine conjugate (P-CYP) preferentially toxic to cancer stem/progenitor cells, and HPMA copolymer-docetaxel conjugate (P-DTX) effective in debulking the tumor mass. Both conjugates were synthesized using RAFT (reversible addition-fragmentation chain transfer) polymerization resulting in narrow molecular weight distribution. The killing effect of the two conjugates against bulk tumor cells and CSCs were evaluated in vitro and in vivo. In PC-3 or RC-92a/hTERT prostate cancer cells, P-CYP preferentially kills and impairs the function of CD133+ prostate cancer stem/progenitor cells; P-DTX was able to kill bulk tumor cells instead of CSCs. In PC-3 xenograft mice model, combination of P-DTX and P-CYP showed the most effective and persistent tumor growth inhibitory effect. In addition, residual tumors contained less CD133+ cancer cells following combination or P-CYP treatments, indicating selective killing of cancer cells with stem/progenitor cell properties. PMID:24041709

  1. Direct Cell-Cell Contact between Mesenchymal Stem Cells and Endothelial Progenitor Cells Induces a Pericyte-Like Phenotype In Vitro

    PubMed Central

    Richards, R. Geoff; Nerlich, Michael; Alini, Mauro

    2014-01-01

    Tissue engineering techniques for the regeneration of large bone defects require sufficient vascularisation of the applied constructs to ensure a sufficient supply of oxygen and nutrients. In our previous work, prevascularised 3D scaffolds have been successfully established by coculture of bone marrow derived stem cells (MSCs) and endothelial progenitor cells (EPCs). We identified stabilising pericytes (PCs) as part of newly formed capillary-like structures. In the present study, we report preliminary data on the interactions between MSCs and EPCs, leading to the differentiation of pericyte-like cells. MSCs and EPCs were seeded in transwell cultures, direct cocultures, and single cultures. Cells were cultured for 10 days in IMDM 10% FCS or IMDM 5% FCS 5% platelet lysate medium. Gene expression of PC markers, CD146, NG2, αSMA, and PDGFR-β, was analysed using RT-PCR at days 0, 3, 7, and 10. The upregulation of CD146, NG2, and αSMA in MSCs in direct coculture with EPCs advocates the MSCs' differentiation towards a pericyte-like phenotype in vitro. These results suggest that pericyte-like cells derive from MSCs and that cell-cell contact with EPCs is an important factor for this differentiation process. These findings emphasise the concept of coculture strategies to promote angiogenesis for cell-based tissue engineered bone grafts. PMID:24563864

  2. N-Stearoyl-L-Tyrosine Inhibits the Senescence of Neural Stem/Progenitor Cells Induced by Aβ1–42 via the CB2 Receptor

    PubMed Central

    Li, Wen-Qing; Wang, Ze-jian; Liu, Sha; Hu, Yue; Yin, Ming; Lu, Yang

    2016-01-01

    Alzheimer's disease, one of the neurodegenerative diseases, shows the progressive senescence of neural progenitor/stem cells. N-Stearoyl-L-tyrosine (NsTyr) showed neuroprotective effect against chronic brain ischemia in previous reports. In the present study, we find the antisenescent effects of NsTyr-2K in NSPCs induced by Aβ1–42 in vitro. Cell viability of NSPCs was evaluated by CCK8 assay; SA-β-gal staining was used to evaluate senescence of NSPCs. CB receptors were detected by immunohistochemistry in NSPCs. AM251 or AM630 was used to offset the anti-senescence effects afforded by NsTyr-2K. The positive rate of SA-β-gal staining was significantly increased in NSPCs after incubation with Aβ1–42 for 9 days. CB receptors were found on the surface of NSPCs. The expression level of CB1 receptors was significantly decreased in NSPCs after incubation with Aβ1–42. This phenomenon was reversed dose-dependently by NsTyr-2K. NsTyr-2K attenuated Aβ1–42 induced NSPCs senescence dose-dependently, and its antisenescence effect was completely abolished by AM630. Aβ1–42 dose-dependently increased the prosenescence molecules p16 and Rb. Their expression was inhibited by NsTyr-2K dose-dependently and blocked by AM630 in NSPCs. These results suggest that NsTyr-2K can alleviate the senescence of NSPCs induced by Aβ1–42 via CB2 receptor. PMID:26989422

  3. [Consensus on neovascular glaucoma].

    PubMed

    Hamard, P; Baudouin, C

    2000-03-01

    Neovascular glaucoma is a dreadful pathology with a rapid spontaneous evolution responsible for painful and blind eye. The main cause is an anterior neovascular proliferation following a broad retinal ischemia. Early diagnosis and treatment are required in order to maintain a good visual status and a satisfactory IOP control with medical, surgical or cylodestructive procedures. In any case, the treatment of the retinal ischemia has to be performed. One must keep in mind that the most efficient way to avoid the incidence of neovascular glaucoma is a strict control of clinical situations potentially responsible for retinal ischemia, namely VRO in elderly patients and diabetic retinopathy in younger patients. PMID:10740059

  4. Neovascularization in Tissue Engineering

    PubMed Central

    Chung, Jennifer C.-Y.; Shum-Tim, Dominique

    2012-01-01

    A prerequisite for successful tissue engineering is adequate vascularization that would allow tissue engineering constructs to survive and grow. Angiogenic growth factors, alone and in combination, have been used to achieve this, and gene therapy has been used as a tool to enable sustained release of these angiogenic proteins. Cell-based therapy using endothelial cells and their precursors presents an alternative approach to tackling this challenge. These studies have occurred on a background of advancements in scaffold design and assays for assessing neovascularization. Finally, several studies have already attempted to translate research in neovascularization to clinical use in the blossoming field of therapeutic angiogenesis. PMID:24710553

  5. Polymeric materials for neovascularization

    NASA Astrophysics Data System (ADS)

    DeVolder, Ross John

    Revascularization therapies have emerged as a promising strategy to treat various acute and chronic wounds, cardiovascular diseases, and tissue defects. It is common to either administer proangiogenic growth factors, such as vascular endothelial growth factor (VEGF), or transplant cells that endogenously express multiple proangiogenic factors. Additionally, these strategies utilize a wide variety of polymeric systems, including hydrogels and biodegradable plastics, to deliver proangiogenic factors in a sophisticated manner to maintain a sustained proangiogenic environment. Despite some impressive results in rebuilding vascular networks, it is still a challenging task to engineer mature and functional neovessels in target tissues, because of the increasing complexities involved with neovascularization applications. To resolve these challenges, this work aims to design a wide variety of proangiogenic biomaterial systems with tunable properties used for neovascularization therapies. This thesis describes the design of several biomaterial systems used for the delivery of proangiogenic factors in neovascularization therapies, including: an electrospun/electrosprayed biodegradable plastic patch used for directional blood vessel growth (Chapter 2), an alginate-g-pyrrole hydrogel system that biochemically stimulates cellular endogenous proangiogenic factor expression (Chapter 3), an enzyme-catalyzed alginate-g-pyrrole hydrogel system for VEGF delivery (Chapter 4), an enzyme-activated alginate-g-pyrrole hydrogel system with systematically controllable electrical and mechanical properties (Chapter 5), and an alginate-g-pyrrole hydrogel that enables the decoupled control of electrical conductivity and mechanical rigidity and is use to electrically stimulate cellular endogenous proangiogenic factor expression (Chapter 6). Overall, the biomaterial systems developed in this thesis will be broadly useful for improving the quality of a wide array of molecular and cellular based

  6. Inflammatory Choroidal Neovascularization

    PubMed Central

    Neri, Piergiorgi; Lettieri, Marta; Fortuna, Cinzia; Manoni, Mara; Giovannini, Alfonso

    2009-01-01

    Purpose and Methods: Choroidal neovascularization (CNV) can be a severe sight-threatening sequela, which can be secondary to both infectious and noninfectious uveitis. This review summarizes the different diseases associated with CNV, highlighting new treatment modalities and the possible strategies, which could be applied for the therapy of this occurrence. Results: Since CNV can often originate from posterior pole lesions and can be hard to identify, an accurate examination is mandatory in order to identify the correct diagnosis. In the majority of cases, fluorescein angiography (FA), indocyanine green angiography (ICGA) and optical coherence tomography (OCT) enable the determination of the clinical characteristics of the CNV. An infectious disease should be looked for to include a suitable therapy when available. The treatment strategy for CNV secondary to noninfectious uveal inflammations should be directed at controlling the inflammatory process. Systemic corticosteroids with or without immunosuppressive agents are indicated even when the CNV occurs with apparently inactive uveitis: Chronic subclinical inflammation can be the basis for the pathogenesis of CNV. Additional therapies aimed directly at the neovascular process, such as the intravitreal anti-Vascular Endothelial Growth Factor (VEGF) agents, are recommended particularly when the therapy shows an insufficient response. Conclusion: CNV secondary to uveitis is a severe sequela leading to significant visual impairment. ICGA is mandatory in order to obtain relevant information about the choroidal status. Several therapeutic options have been considered, but no guidelines are provided at the moment. Moreover, the current data are still only based on case reports or small series. For such reasons, further trials are mandatory to validate the preliminary available results. PMID:20404991

  7. Implants for draining neovascular glaucoma.

    PubMed Central

    Molteno, A C; Van Rooyen, M M; Bartholomew, R S

    1977-01-01

    The implant design, surgical technique, and pharmacological methods of controlling bleb fibrosis, used to treat neovascular glaucoma, are described, together with the results of 14 operations performed on 12 eyes. Images PMID:843508

  8. [Current treatments for corneal neovascularization].

    PubMed

    Benayoun, Y; Petellat, F; Leclerc, O; Dost, L; Dallaudière, B; Reddy, C; Robert, P-Y; Salomon, J-L

    2015-12-01

    The extension of blood vessels into the normally avascular stroma defines corneal neovascularization. Though this phenomenon, pathophysiological and clinical features are well characterized, therapeutic modalities have been hindered by a lack of safe, efficacious and non-controversial treatments. In this literature review, we focus on available therapeutic options in light of recent evidence provided by animal and clinical studies. First, this review will focus on pharmacological treatments that target angiogenesis. The low cost and market availability of bevacizumab make it the first anti-angiogenic therapy choice, and it has demonstrable efficacy in reducing corneal neovascularization when administered topically or subconjunctivally. However, novel anti-angiogenic molecules targeting the intracellular pathways of angiogenesis (siRNA, antisense oligonucleotides) provide a promising alternative. Laser therapy (direct photocoagulation or photo-dynamic therapy) and fine needle diathermy also find a place in the treatment of stabilized corneal neovascularization alone or in association with anti-angiogenic therapy. Additionally, ocular surface reconstruction using amniotic membrane graft or limbal stem cell transplantation is essential when corneal neovascularization is secondary to primary or acquired limbal deficiency. PMID:26522890

  9. Corneal neovascularization and biological therapy

    PubMed Central

    Voiculescu, OB; Voinea, LM; Alexandrescu, C

    2015-01-01

    Corneal avascularity is necessary for the preservation of optimal vision. The cornea maintains a dynamic balance between pro- and antiangiogenic factors that allows it to remain avascular under normal homeostatic conditions. Corneal neovascularization (NV) is a condition that can develop in response to inflammation, hypoxia, trauma, or limbal stem cell deficiency and it is a significant cause of blindness. New therapeutic options for diseases of the cornea and ocular surface are now being explored in experimental animals and clinical trials. Antibody based biologics are being tested for their ability to reduce blood and lymphatic vessel ingrowth into the cornea, and to reduce inflammation. Numerous studies have shown that biologics with specificity for VEGF A such as bevacizumab and ranibizumab (a recombinant antibody and an antibody fragment, respectively) or anti-tumor necrosis factor-α microantibody, are effective in the treatment of corneal neovascularization. PMID:26664467

  10. [Current trends in neovascular glaucoma treatment].

    PubMed

    Vancea, P P; Abu-Taleb, A

    2005-01-01

    Neovascular glaucoma is divided in three clinical stages: rubeosis iridis, secondary open-angle glaucoma, and synechia of the angle-closure glaucoma. 36% of neovascular glaucomas occurs after central retinal vein occlusion, 32% after diabetic proliferative retinopathy, and 13% occurs after carotid artery obstructive. The key of success in the treatment of neovascular glaucoma is the early and rightly diagnosis, the treatment is aimed mainly at relieving pain, as the prognosis for maintaining visual function is extremely poor. The most important surgical procedures are trabeculectomy, artificial drainage shunts and cyclo-distraction by trans-scleral diode laser. This essay presents a synthesis of modern principle data concerning neovascular glaucoma. PMID:16607783

  11. Kinin receptor agonism restores hindlimb postischemic neovascularization capacity in diabetic mice.

    PubMed

    Desposito, Dorinne; Potier, Louis; Chollet, Catherine; Gobeil, Fernand; Roussel, Ronan; Alhenc-Gelas, Francois; Bouby, Nadine; Waeckel, Ludovic

    2015-02-01

    Limb ischemia is a major complication of thromboembolic diseases. Diabetes worsens prognosis by impairing neovascularization. Genetic or pharmacological inactivation of the kallikrein-kinin system aggravates limb ischemia in nondiabetic animals, whereas angiotensin I-converting enzyme/kininase II inhibition improves outcome. The role of kinins in limb ischemia in the setting of diabetes is not documented. We assessed whether selective activation of kinin receptors by pharmacological agonists can influence neovascularization in diabetic mice with limb ischemia and have a therapeutic effect. Selective pseudopeptide kinin B1 or B2 receptor agonists resistant to peptidase action were administered by osmotic minipumps at a nonhypotensive dosage for 14 days after unilateral femoral artery ligation in mice previously rendered diabetic by streptozotocin. Comparison was made with ligatured, nonagonist-treated nondiabetic and diabetic mice. Diabetes reduced neovascularization, assessed by microangiography and histologic capillary density analysis, by roughly 40%. B1 receptor agonist or B2 receptor agonist similarly restored neovascularization in diabetic mice. Neovascularization in agonist-treated diabetic mice was indistinguishable from nondiabetic mice. Both treatments restored blood flow in the ischemic hindfoot, measured by laser-Doppler perfusion imaging. Macrophage infiltration increased 3-fold in the ischemic gastrocnemius muscle during B1 receptor agonist or B2 receptor agonist treatment, and vascular endothelial growth factor (VEGF) level increased 2-fold. Both treatments increased, by 50-100%, circulating CD45/CD11b-positive monocytes and CD34(+)/VEGFR2(+) progenitor cells. Thus, selective pharmacological activation of B1 or B2 kinin receptor overcomes the effect of diabetes on postischemic neovascularization and restores tissue perfusion through monocyte/macrophage mobilization. Kinin receptors are potential therapeutic targets in limb ischemia in diabetes. PMID

  12. Endothelial progenitor cells: identity defined?

    PubMed Central

    Timmermans, Frank; Plum, Jean; Yöder, Mervin C; Ingram, David A; Vandekerckhove, Bart; Case, Jamie

    2009-01-01

    Abstract In the past decade, researchers have gained important insights on the role of bone marrow (BM)-derived cells in adult neovascularization. A subset of BM-derived cells, called endothelial progenitor cells (EPCs), has been of particular interest, as these cells were suggested to home to sites of neovascularization and neoendothelialization and differentiate into endothelial cells (ECs) in situ, a process referred to as postnatal vasculogenesis. Therefore, EPCs were proposed as a potential regenerative tool for treating human vascular disease and a possible target to restrict vessel growth in tumour pathology. However, conflicting results have been reported in the field, and the identification, characterization, and exact role of EPCs in vascular biology is still a subject of much discussion. The focus of this review is on the controversial issues in the field of EPCs which are related to the lack of a unique EPC marker, identification challenges related to the paucity of EPCs in the circulation, and the important phenotypical and functional overlap between EPCs, haematopoietic cells and mature ECs. We also discuss our recent findings on the origin of endothelial outgrowth cells (EOCs), showing that this in vitro defined EC population does not originate from circulating CD133+ cells or CD45+ haematopoietic cells. PMID:19067770

  13. Endogenous endostatin inhibits choroidal neovascularization.

    PubMed

    Marneros, Alexander G; She, Haicheng; Zambarakji, Hadi; Hashizume, Hiroya; Connolly, Edward J; Kim, Ivana; Gragoudas, Evangelos S; Miller, Joan W; Olsen, Bjorn R

    2007-12-01

    Endostatin, a fragment of the basement membrane component collagen XVIII, exhibits antiangiogenic properties in vitro and in vivo when high doses are administered. It is not known whether endogenous endostatin at physiological levels has a protective role as an inhibitor of pathological angiogenesis, such as choroidal neovascularization (CNV) in age-related macular degeneration. Using a laser injury model, we induced CNV in mice lacking collagen XVIII/endostatin and in control mice. CNV lesions in mutant mice were approximately 3-fold larger than in control mice and showed increased vascular leakage. These differences were independent of age-related changes at the choroid-retina interface. Ultrastructural analysis of the choroidal vasculature in mutant mice excluded morphological vascular abnormalities as a cause for the larger CNV lesions. When recombinant endostatin was administered to collagen XVIII/endostatin-deficient mice, CNV lesions were similar to those seen in control mice. In control mice treated with recombinant endostatin, CNV lesions were almost undetectable. These findings demonstrate that endogenous endostatin is an inhibitor of induced angiogenesis and that administration of endostatin potently inhibits CNV growth and vascular leakage. Endostatin may have a regulatory role in the pathogenesis of CNV and could be used therapeutically to inhibit growth and leakage of CNV lesions. PMID:17526870

  14. Progenitor Epithelium

    PubMed Central

    Marty-Santos, Leilani

    2015-01-01

    Insulin-producing β cells within the vertebrate fetal pancreas acquire their fate in a step-wise manner. Whereas the intrinsic factors dictating the transcriptional or epigenetic status of pancreatic lineages have been intensely examined, less is known about cell–cell interactions that might constitute a niche for the developing β cell lineage. It is becoming increasingly clear that understanding and recapitulating these steps may instruct in vitro differentiation of embryonic stem cells and/or therapeutic regeneration. Indeed, directed differentiation techniques have improved since transitioning from 2D to 3D cultures, suggesting that the 3D microenvironment in which β cells are born is critical. However, to date, it remains unknown whether the changing architecture of the pancreatic epithelium impacts the fate of cells therein. An emerging challenge in the field is to elucidate how progenitors are allocated during key events, such as the stratification and subsequent resolution of the pre-pancreatic epithelium, as well as the formation of lumens and branches. Here, we assess the progenitor epithelium and examine how it might influence the emergence of pancreatic multipotent progenitors (MPCs), which give rise to β cells and other pancreatic lineages. PMID:26216134

  15. The role of biomaterial properties in peri-implant neovascularization

    NASA Astrophysics Data System (ADS)

    Raines, Andrew Lawrence

    An understanding of the interactions between orthopaedic and dental implant surfaces with the surrounding host tissue is critical in the design of next generation implants to improve osseointegration and clinical success rates. Critical to the process of osseointegration is the rapid establishment of a patent neovasculature in the peri-implant space to allow for the delivery of oxygen, nutrients, and progenitor cells. The central aim of this thesis is to understand how biomaterials regulate cellular and host tissue response to elicit a pro-angiogenic microenvironment at the implant/tissue interface. To address this question, the studies performed in this thesis aim to (1) determine whether biomaterial surface properties can modulate the production and secretion of pro-angiogenic growth factors by cells, (2) determine the role of integrin and VEGF-A signaling in the angiogenic response of cells to implant surface features, and (3) to determine whether neovascularization in response to an implanted biomaterial can be modulated in vivo. The results demonstrate that biomaterial surface microtopography and surface energy can increase the production of pro-angiogenic growth factors by osteoblasts and that these growth factors stimulate the differentiation of endothelial cells in a paracrine manner and the results suggest that signaling through specific integrin receptors affects the production of angiogenic growth factors by osteoblast-like cells. Further, using a novel in vivo model, the results demonstrate that a combination of a rough surface microtopography and high surface energy can improve bone-to-implant contact and neovascularization. The results of these studies also suggest that VEGF-A produced by osteoblast-like cells has both an autocrine and paracrine effect. VEGF-A silenced cells exhibited reduced production of both pro-angiogenic and osteogenic growth factors in response to surface microtopgraphy and surface energy, and conditioned media from VEGF

  16. Host immune cellular reactions in corneal neovascularization

    PubMed Central

    Abdelfattah, Nizar S.; Amgad, Mohamed; Zayed, Amira A

    2016-01-01

    Corneal neovascularization (CNV) is a global important cause of visual impairment. The immune mechanisms leading to corneal heme- and lymphangiogenesis have been extensively studied over the past years as more attempts were made to develop better prophylactic and therapeutic measures. This article aims to discuss immune cells of particular relevance to CNV, with a focus on macrophages, Th17 cells, dendritic cells and the underlying immunology of common pathologies involving neovascularization of the cornea. Hopefully, a thorough understanding of these topics would propel the efforts to halt the detrimental effects of CNV. PMID:27162740

  17. Corneal Neovascularization: An Anti-VEGF Therapy Review

    PubMed Central

    Chang, Jin-Hong; Garg, Nitin K.; Lunde, Elisa; Han, Kyu-Yeon; Jain, Sandeep; Azar, Dimitri T.

    2013-01-01

    Corneal neovascularization is a serious condition that can lead to a profound decline in vision. The abnormal vessels block light, cause corneal scarring, compromise visual acuity, and may lead to inflammation and edema. Corneal neovascularization occurs when the balance between angiogenic and antiangiogenic factors is tipped toward angiogenic molecules. Vascular endothelial growth factor (VEGF), one of the most important mediators of angiogenesis, is upregulated during neovascularization. In fact, anti-VEGF agents have efficacy in the treatment of neovascular age-related macular degeneration, diabetic retinopathy, macular edema, neovascular glaucoma, and other neovascular diseases. These same agents have great potential for the treatment of corneal neovascularization. We review some of the most promising anti-VEGF therapies, including bevacizumab, VEGF trap, siRNA, and tyrosine kinase inhibitors. PMID:22898649

  18. Endothelial progenitor cells and burn injury - exploring the relationship.

    PubMed

    Banyard, Derek A; Adnani, Blake O; Melkumyan, Satenik; Araniego, Cheryl Ann; Widgerow, Alan D

    2016-01-01

    Burn wounds result in varying degrees of soft tissue damage that are typically graded clinically. Recently a key participant in neovascularization, the endothelial progenitor cell, has been the subject of intense cardiovascular research to explore whether it can serve as a biomarker for vascular injury. In this review, we examine the identity of the endothelial progenitor cell as well as the evidence that support its role as a key responder after burn insult. While there is conflicting evidence with regards to the delta of endothelial progenitor cell mobilization and burn severity, it is clear that they play an important role in wound healing. Systematic and controlled studies are needed to clarify this relationship, and whether this population can serve as a biomarker for burn severity. PMID:27574674

  19. Gene Therapies for Neovascular Age-Related Macular Degeneration.

    PubMed

    Pechan, Peter; Wadsworth, Samuel; Scaria, Abraham

    2015-07-01

    Pathological neovascularization is a key component of the neovascular form (also known as the wet form) of age-related macular degeneration (AMD) and proliferative diabetic retinopathy. Several preclinical studies have shown that antiangiogenesis strategies are effective for treating neovascular AMD in animal models. Vascular endothelial growth factor (VEGF) is one of the main inducers of ocular neovascularization, and several clinical trials have shown the benefits of neutralizing VEGF in patients with neovascular AMD or diabetic macular edema. In this review, we summarize several preclinical and early-stage clinical trials with intraocular gene therapies, which have the potential to reduce or eliminate the repeated intravitreal injections that are currently required for the treatment of neovascular AMD. PMID:25524721

  20. Photodynamic therapy for treatment subretinal neovascularization

    NASA Astrophysics Data System (ADS)

    Avetisov, Sergey E.; Budzinskaja, Maria V.; Kiseleva, Tatyana N.; Balatskaya, Natalia V.; Gurova, Irina V.; Loschenov, Viktor B.; Shevchik, Sergey A.; Kuzmin, Sergey G.; Vorozhtsov, Georgy N.

    2007-07-01

    This work are devoted our experience with photodynamic therapy (PDT) with <> for patients with choroidal neovascularization (CNV). 18 patients with subfoveal CNV in age-related macular degeneration (AMD), 24 patients with subfoveal CNV in pathological myopia (PM) and 4 patients with subfoveal CNV associated with toxoplasmic retinochoroiditis were observed. CNV was 100% classic in all study patients. Standardized protocol refraction, visual acuity testing, ophthalmologic examinations, biomicroscopy, fluorescein angiography, and ultrasonography were performed before treatment and 1 month, 3 months, 6 months, and 1 year after treatment; were used to evaluate the results of photodynamic therapy with <> (0.02% solution of mixture sulfonated aluminium phtalocyanine 0.05 mg/kg, intravenously). A diode laser (<>, Inc, Moscow) was used operating in the range of 675 nm. Need for retreatment was based on fluorescein angiographic evidence of leakage at 3-month follow-up intervals. At 3, 6, 9 month 26 (56.5%) patients had significant improvement in the mean visual acuity. At the end of the 12-month minimal fluorescein leakage from choroidal neovascularization was seen in 12 (26.1%) patients and the mean visual acuity was slightly worse than 0.2 which was not statistically significant as compared with the baseline visual acuity. Patients with fluorescein leakage from CNV underwent repeated PDT with <>. 3D-mode ultrasound shown the decreasing thickness of chorioretinal complex in CNV area. Photodynamic therapy with <> can safely reduce the risk of severe vision loss in patients with predominantly classic subfoveal choroidal neovascularization secondary to AMD, PM and toxoplasmic retinochoroiditis.

  1. Nanoparticles for the treatment of ocular neovascularizations.

    PubMed

    Hennig, Robert; Goepferich, Achim

    2015-09-01

    Neovascular diseases of the posterior eye like age-related macular degeneration, proliferative diabetic retinopathy or retinopathy of prematurity carry a tremendous burden for patient and health care system alike. Although intravitreal injections of anti-VEGF based therapeutics have significantly improved the visual outcome for many patients, current therapeutic options still show significant drawbacks such as the injection-related risk of contracting an infection. Due to their ability to encapsulate drugs with otherwise poor bioavailability, accumulate in areas of increased vascular permeability and control the release of active ingredients over time, nanoparticle systems have been widely researched to enhance current therapeutic strategies and expand the therapeutic arsenal. In this review, emphasis is placed both on the possibilities and drawbacks that a systemic nanoparticle-based therapy could have in the context of neovascular posterior eye diseases. Recent investigations into intravenous and intravitreal administration of nanomaterials and their potential to deliver potent drugs and genes to pathologic lesions will also be presented. Furthermore, we will focus on the exceptional anti-oxidative and anti-angiogenic properties of selected nanoscale systems that carve out new paths for the treatment of these severe posterior eye diseases. PMID:25758124

  2. Carotid intraplaque neovascularization quantification software (CINQS).

    PubMed

    Akkus, Zeynettin; van Burken, Gerard; van den Oord, Stijn C H; Schinkel, Arend F L; de Jong, Nico; van der Steen, Antonius F W; Bosch, Johan G

    2015-01-01

    Intraplaque neovascularization (IPN) is an important biomarker of atherosclerotic plaque vulnerability. As IPN can be detected by contrast enhanced ultrasound (CEUS), imaging-biomarkers derived from CEUS may allow early prediction of plaque vulnerability. To select the best quantitative imaging-biomarkers for prediction of plaque vulnerability, a systematic analysis of IPN with existing and new analysis algorithms is necessary. Currently available commercial contrast quantification tools are not applicable for quantitative analysis of carotid IPN due to substantial motion of the carotid artery, artifacts, and intermittent perfusion of plaques. We therefore developed a specialized software package called Carotid intraplaque neovascularization quantification software (CINQS). It was designed for effective and systematic comparison of sets of quantitative imaging biomarkers. CINQS includes several analysis algorithms for carotid IPN quantification and overcomes the limitations of current contrast quantification tools and existing carotid IPN quantification approaches. CINQS has a modular design which allows integrating new analysis tools. Wizard-like analysis tools and its graphical-user-interface facilitate its usage. In this paper, we describe the concept, analysis tools, and performance of CINQS and present analysis results of 45 plaques of 23 patients. The results in 45 plaques showed excellent agreement with visual IPN scores for two quantitative imaging-biomarkers (The area under the receiver operating characteristic curve was 0.92 and 0.93). PMID:25561454

  3. Hyperoxia, Endothelial Progenitor Cell Mobilization, and Diabetic Wound Healing

    PubMed Central

    Liu, Zhao-Jun

    2008-01-01

    Abstract Diabetic foot disease is a major health problem, which affects 15% of the 200 million patients with diabetes worldwide. Diminished peripheral blood flow and decreased local neovascularization are critical factors that contribute to the delayed or nonhealing wounds in these patients. The correction of impaired local angiogenesis may be a key component in developing therapeutic protocols for treating chronic wounds of the lower extremity and diabetic foot ulcers. Endothelial progenitor cells (EPCs) are the key cellular effectors of postnatal neovascularization and play a central role in wound healing, but their circulating and wound-level numbers are decreased in diabetes, implicating an abnormality in EPC mobilization and homing mechanisms. The deficiency in EPC mobilization is presumably due to impairment of eNOS-NO cascade in bone marrow (BM). Hyperoxia, induced by a clinically relevant hyperbaric oxygen therapy (HBO) protocol, can significantly enhance the mobilization of EPCs from the BM into peripheral blood. However, increased circulating EPCs failed to reach to wound tissues. This is partly a result of downregulated production of SDF-1α in local wound lesions with diabetes. Administration of exogenous SDF-1α into wounds reversed the EPC homing impairment and, with hyperoxia, synergistically enhanced EPC mobilization, homing, neovascularization, and wound healing. Antioxid. Redox Signal. 10, 1869–1882. PMID:18627349

  4. Enrichment and terminal differentiation of striated muscle progenitors in vitro

    SciTech Connect

    Becher, Ulrich M.; Breitbach, Martin; Sasse, Philipp; Garbe, Stephan; Ven, Peter F.M. van der; Fuerst, Dieter O.; Fleischmann, Bernd K.

    2009-10-01

    Enrichment and terminal differentiation of mammalian striated muscle cells is severely hampered by fibroblast overgrowth, de-differentiation and/or lack of functional differentiation. Herein we report a new, reproducible and simple method to enrich and terminally differentiate muscle stem cells and progenitors from mice and humans. We show that a single gamma irradiation of muscle cells induces their massive differentiation into structurally and functionally intact myotubes and cardiomyocytes and that these cells can be kept in culture for many weeks. Similar results are also obtained when treating skeletal muscle-derived stem cells and progenitors with Mitomycin C.

  5. The neurotrophin receptor p75NTR triggers endothelial cell apoptosis and inhibits angiogenesis: implications for diabetes-induced impairment of reparative neovascularization

    PubMed Central

    Caporali, Andrea; Pani, Elisabetta; Horrevoets, Anton J. G.; Kraenkel, Nicolle; Oikawa, Atsuhiko; Sala-Newby, Graciela B.; Meloni, Marco; Cristofaro, Brunella; Graiani, Gallia; Leroyer, Aurelie; Boulanger, Chantal; Herman, Andrew; Spinetti, Gaia; Yoon, Sung Ok; Madeddu, Paolo; Emanueli, Costanza

    2009-01-01

    Diabetes compromises endothelial function and inhibits reparative neovascularization. The neurotrophin receptor p75NTR is scarcely present in healthy endothelial cells (EC), but diabetes induces p75NTR in capillary EC of ischemic limb muscles. Here, we show that forced p75NTR expression impairs survival, proliferation, migration, and adhesion capacities of EC and endothelial progenitor cells (EPC) and inhibits EC tube formation. In EC, p75NTR depresses the VEGF-A/Akt/eNOS/NO pathway and reduces VEGF-A, ITGB1, BIRC5, PTTG1, and VEZF1 mRNA levels. Moreover, both diabetes and p75NTR transfer down-regulate VEGF-A, ITGB1, and VEZF1 in adductor muscles. Forced p75NTR expression by ischemic limb muscles impairs post-ischemic neovascularization and blood flow recovery in normoglycemic mice. Conversely, p75NTR inhibition in diabetic muscles restores proper post-ischemic neovascularization and prevents apoptosis of muscular capillary EC and bone marrow-resident Sca-1+Lin- progenitor cells. Collectively, our data identify the anti-angiogenic action of p75NTR and suggests the therapeutic potential of p75NTR inhibition to combat diabetes-induced microvascular liabilities. PMID:18566344

  6. Pachychoroid neovasculopathy in extramacular choroidal neovascularization

    PubMed Central

    Gupta, Mrinali Patel; Rusu, Irene; Seidman, Carly; Orlin, Anton; D’Amico, Donald J; Kiss, Szilard

    2016-01-01

    Purpose To review a series of extramacular choroidal neovascular membranes (CNVMs) in the context of their choroidal features, as determined by optical coherence tomography (OCT). Methods Patients with extramacular CNVMs were identified from a tertiary care center through a review of records. The charts and cases were reviewed using multimodal imaging including fundus photography, OCT, fluorescein angiography (FA), and indocyanine angio-graphy (ICG). Results Of six patients with extramacular CNVMs evaluated in this series, four patients (66.7%) exhibited pachychoroidopathy on OCT imaging under or adjacent to the extramacular CNVM. All four of these patients also exhibited pachychoroidopathy in the macular OCT distant from the CNVM. Conclusion Pachychoroidopathy is implicated in some cases of extramacular CNVMs. This represents the first report, to our knowledge, of pachychoroidopathy in extramacular CNVM. PMID:27471372

  7. Angiogenesis and parasitic helminth-associated neovascularization.

    PubMed

    Dennis, Roger D; Schubert, Uwe; Bauer, Christian

    2011-04-01

    Successful metazoan parasitism, among many other factors, requires a supply of nutrients and the removal of waste products. There is a prerequisite for a parasite-defined vasculature. The angiogenic mechanism(s) involved presumably depend on the characteristics of the tissue- and vascular system-dwelling, parasitic helminths. Simplistically, 2 possibilities or a combination of both have been considered in this review. The multifactorial induction of parasitic helminth-associated neovascularization could arise through, either a host-, a parasite- or a host-/parasite-dependent, angiogenic switch. Most studies appear to support the first and third hypotheses, but evidence exists for the intrahepatic cestode Echinococcus multilocularis, the free-living nematode Caenorhabditis elegans and the intravascular trematode Schistosoma mansoni for the second inference. In contrast, the nematode anti-coagulant protein NAPc2 from adult Ancylostoma caninum is also an anti-angiogenic factor. PMID:21232174

  8. Doxycycline-mediated Inhibition of Choroidal Neovascularization

    PubMed Central

    Samtani, S.; Amaral, J.; Campos, M.; Fariss, R. N.; Becerra, S. P.

    2010-01-01

    Purpose Doxycycline, a broad spectrum antibiotic, has certain anti-angiogenic properties and can inhibit matrix metalloproteinases (MMPs/gelatinases). We investigated the effects of doxycycline on choroidal neovascularization (CNV), and regulation of MMP-2/-9 and pigment epithelium-derived factor (PEDF). Methods Doxycycline was orally administered to rats at 500, 50, 5, and 0.5 mg/kg/day, using non-treated animals as controls. Experimental CNV was induced with laser 7 days after doxycycline treatment started. At seven days post-induction, animals were euthanized, and eyes collected. RPE/choroid flat-mounts were labeled with isolectin IB4 to determine CNV lesion volumes using confocal microscopy and Volocity® software. MMP-2, MMP-9 and PEDF protein levels were determined by ELISA. MMP catalytic activity was determined in solution using fluorogenic gelatin and peptide substrates, by gelatin zymography in SDS-PAGE and by in situ DQ-gelatin zymography in RPE/choroid sections. Results CNV complex lesion volumes decreased with doxycycline in a dose-response relationship. A dosage of 500 mg/kg/day caused a 70% inhibition of CNV complex volume compared to control animals. Doxycycline elevated PEDF levels in plasma, and did not affect the plasma pro- and active MMP-2 and MMP-9 levels. However, the in vitro enzymatic activities of purified MMP-2 and MMP-9 declined significantly with doxycycline. MMP-2, MMP-9 and gelatinolytic activities in situ increased early in CNV lesion development. Doxycycline treatments and exogenous additions inhibited gelatinolytic activities in CNV lesions. Conclusions Doxycycline effectively hampered the progression of experimental CNV. The results suggest that orally administrated doxycycline can reach the choroid to attenuate proteolytic enzymes that remodel Bruch's membrane and promote the anti-angiogenic PEDF to inhibit neovascularization. PMID:19516001

  9. Endothelial Progenitor Cell Migration-Enhancing Factors in the Secretome of Placental-Derived Mesenchymal Stem Cells

    PubMed Central

    Kamprom, Witchayaporn; Kheolamai, Pakpoom; U-Pratya, Yaowalak; Supokawej, Aungkura; Wattanapanitch, Methichit; Laowtammathron, Chuti; Roytrakul, Sittiruk; Issaragrisil, Surapol

    2016-01-01

    Therapeutic potentials of mesenchymal stem cells (MSCs) depend largely on their ability to secrete cytokines or factors that modulate immune response, enhance cell survival, and induce neovascularization in the target tissues. We studied the secretome profile of gestational tissue-derived MSCs and their effects on functions of endothelial progenitor cells (EPCs), another angiogenic cell type that plays an important role during the neovascularization. MSCs derived from placental tissues (PL-MSCs) significantly enhanced EPC migration while BM-MSCs, which are the standard source of MSCs for various clinical applications, did not. By using protein fractionation and mass spectrometry analysis, we identified several novel candidates for EPC migration enhancing factor in PL-MSCs secretome that could be used to enhance neovascularization in the injured/ischemic tissues. We recommend that the strategy developed in our study could be used to systematically identify therapeutically useful molecules in the secretomes of other MSC sources for the clinical applications. PMID:26880942

  10. Secondary Sphere Formation Enhances the Functionality of Cardiac Progenitor Cells

    PubMed Central

    Cho, Hyun-Jai; Lee, Ho-Jae; Youn, Seock-Won; Koh, Seok-Jin; Won, Joo-Yun; Chung, Yeon-Ju; Cho, Hyun-Ju; Yoon, Chang-Hwan; Lee, Sae-Won; Lee, Eun Ju; Kwon, Yoo-Wook; Lee, Hae-Young; Lee, Sang Hun; Ho, Won-Kyung; Park, Young-Bae; Kim, Hyo-Soo

    2012-01-01

    Loss of cardiomyocytes impairs cardiac function after myocardial infarction (MI). Recent studies suggest that cardiac stem/progenitor cells could repair the damaged heart. However, cardiac progenitor cells are difficult to maintain in terms of purity and multipotency when propagated in two-dimensional culture systems. Here, we investigated a new strategy that enhances potency and enriches progenitor cells. We applied the repeated sphere formation strategy (cardiac explant → primary cardiosphere (CS) formation → sphere-derived cells (SDCs) in adherent culture condition → secondary CS formation by three-dimensional culture). Cells in secondary CS showed higher differentiation potentials than SDCs. When transplanted into the infarcted myocardium, secondary CSs engrafted robustly, improved left ventricular (LV) dysfunction, and reduced infarct sizes more than SDCs did. In addition to the cardiovascular differentiation of transplanted secondary CSs, robust vascular endothelial growth factor (VEGF) synthesis and secretion enhanced neovascularization in the infarcted myocardium. Microarray pathway analysis and blocking experiments using E-selectin knock-out hearts, specific chemicals, and small interfering RNAs (siRNAs) for each pathway revealed that E-selectin was indispensable to sphere initiation and ERK/Sp1/VEGF autoparacrine loop was responsible for sphere maturation. These results provide a simple strategy for enhancing cellular potency for cardiac repair. Furthermore, this strategy may be implemented to other types of stem/progenitor cell-based therapy. PMID:22713697

  11. Neovascular glaucoma after helium ion irradiation for uveal melanoma

    SciTech Connect

    Kim, M.K.; Char, D.H.; Castro, J.L.; Saunders, W.M.; Chen, G.T.; Stone, R.D.

    1986-02-01

    Neovascular glaucoma developed in 22 of 169 uveal melanoma patients treated with helium ion irradiation. Most patients had large melanomas; no eyes containing small melanomas developed anterior segment neovascularization. The mean onset of glaucoma was 14.1 months (range, 7-31 months). The incidence of anterior segment neovascularization increased with radiation dosage; there was an approximately three-fold increase at 80 GyE versus 60 GyE of helium ion radiation (23% vs. 8.5%) (P less than 0.05). Neovascular glaucoma occurred more commonly in larger tumors; the incidence was not affected by tumor location, presence of subretinal fluid, nor rate of tumor regression. Fifty-three percent of patients had some response with intraocular pressures of 21 mmHg or less to a combination of antiglaucoma treatments.

  12. NADPH oxidase 2 plays a role in experimental corneal neovascularization.

    PubMed

    Chan, Elsa C; van Wijngaarden, Peter; Chan, Elsie; Ngo, Darleen; Wang, Jiang-Hui; Peshavariya, Hitesh M; Dusting, Gregory J; Liu, Guei-Sheung

    2016-05-01

    Corneal neovascularization, the growth of new blood vessels in the cornea, is a leading cause of vision impairment after corneal injury. Neovascularization typically occurs in response to corneal injury such as that caused by infection, physical trauma, chemical burns or in the setting of corneal transplant rejection. The NADPH oxidase enzyme complex is involved in cell signalling for wound-healing angiogenesis, but its role in corneal neovascularization has not been studied. We have now analysed the role of the Nox2 isoform of NADPH oxidase in corneal neovascularization in mice following chemical injury. C57BL/6 mice aged 8-14 weeks were cauterized with an applicator coated with 75% silver nitrate and 25% potassium nitrate for 8 s. Neovascularization extending radially from limbal vessels was observed in corneal whole-mounts from cauterized wild type mice and CD31+ vessels were identified in cauterized corneal sections at day 7. In contrast, in Nox2 knockout (Nox2 KO) mice vascular endothelial growth factor-A (Vegf-A), Flt1 mRNA expression, and the extent of corneal neovascularization were all markedly reduced compared with their wild type controls. The accumulation of Iba-1+ microglia and macrophages in the cornea was significantly less in Nox2 KO than in wild type mice. In conclusion, we have demonstrated that Nox2 is implicated in the inflammatory and neovascular response to corneal chemical injury in mice and clearly VEGF is a mediator of this effect. This work raises the possibility that therapies targeting Nox2 may have potential for suppressing corneal neovascularization and inflammation in humans. PMID:26814205

  13. Angioid streaks - a rare cause of neovascular glaucoma. Case report.

    PubMed

    Ungureanu, E; Geamanu, A; Careba, I; Grecescu, M; Gradinaru, S

    2014-01-01

    Rationale. Neovascular glaucoma is the type of glaucoma most refractory to treatment. The most frequent causes are those associated with retinal hypoxia, such as proliferative diabetic retinopathy, central retinal vein occlusion, branch retinal vein occlusion, central retinal arterial occlusion, ischemic ocular syndrome etc. Rare causes of neovascular glaucoma are multiple and are due to VEGF synthesis associated with chorioretinal inflammations or degenerations. We present a case with neovascular glaucoma associated with an extremely rare cause, angioid streaks Objective. The objective of our prsentation was to asses efficacy of the 5-FU associated trabeculectomy following bevacizumab intravitreal administration Methods and results. Case report of a 48 years old female patient which presented at the emergency room with painful red left eye. At presentation best corrected left eye visual acuity was 1/10, intraocular pressure was 36 mm Hg. Examination established the diagnosis of Neovascular glaucoma associated with angioid streaks. After intravenous Manitol, oral Acetazolamide and topical treatment with fixed combination timolol-brinzolamide, topical steroid and mydriatic intraocular pressure decreased. Intravitreal bevacizumab injection was performed, followed after 3 weeks by trabeculectomy. Discussion. Angioid streaks are an extremely rare cause of neovascular glaucoma. The treatment is similar to the treatment for other causes of neovascular glaucoma. PMID:27057253

  14. Angioid streaks - a rare cause of neovascular glaucoma. Case report.

    PubMed Central

    Ungureanu, E; Geamanu, A; Careba, I; Grecescu, M; Gradinaru, S

    2014-01-01

    Rationale. Neovascular glaucoma is the type of glaucoma most refractory to treatment. The most frequent causes are those associated with retinal hypoxia, such as proliferative diabetic retinopathy, central retinal vein occlusion, branch retinal vein occlusion, central retinal arterial occlusion, ischemic ocular syndrome etc. Rare causes of neovascular glaucoma are multiple and are due to VEGF synthesis associated with chorioretinal inflammations or degenerations. We present a case with neovascular glaucoma associated with an extremely rare cause, angioid streaks Objective. The objective of our prsentation was to asses efficacy of the 5-FU associated trabeculectomy following bevacizumab intravitreal administration Methods and results. Case report of a 48 years old female patient which presented at the emergency room with painful red left eye. At presentation best corrected left eye visual acuity was 1/10, intraocular pressure was 36 mm Hg. Examination established the diagnosis of Neovascular glaucoma associated with angioid streaks. After intravenous Manitol, oral Acetazolamide and topical treatment with fixed combination timolol-brinzolamide, topical steroid and mydriatic intraocular pressure decreased. Intravitreal bevacizumab injection was performed, followed after 3 weeks by trabeculectomy. Discussion. Angioid streaks are an extremely rare cause of neovascular glaucoma. The treatment is similar to the treatment for other causes of neovascular glaucoma PMID:27057253

  15. Is Asthma Related to Choroidal Neovascularization?

    PubMed Central

    Hou, Jing; Gong, Peihua; Zheng, Yi; Zhao, Mingwei; Zhou, Peng; Li, Xiaoxin

    2012-01-01

    Background Age-related degeneration(AMD) and asthma are both diseases that are related to the activation of the complement system. The association between AMD and asthma has been debated in previous studies. The authors investigated the relationship between AMD and asthma systemically. Principal Findings The epidemiological study showed that asthma was related to choroidal neovascularization(CNV) subtype(OR = 1.721, P = 0.023). However, the meta-analysis showed there was no association between AMD and asthma. In an animal model, we found more fluoresce in leakage of CNV lesions by FA analysis and more angiogenesis by histological analysis in rats with asthma. Western blot demonstrated an elevated level of C3α-chain, C3α’-chain and VEGF. After compstatin was intravitreally injected, CNV leakage decreased according to FA analysis, with the level of C3 and VEGF protein decreasing at the same time. Significance This study first investigated the relationship between AMD and asthma systematically, and it was found that asthma could be a risk factor for the development of AMD. The study may provide a better understanding of the disease, which may advance the potential for screening asthma patients in clinical practice. PMID:22567103

  16. Matrilin-1 Is an Inhibitor of Neovascularization*

    PubMed Central

    Foradori, Matthew J.; Chen, Qian; Fernandez, Cecilia A.; Harper, Jay; Li, Xin; Tsang, Paul C. W.; Langer, Robert; Moses, Marsha A.

    2014-01-01

    In the course of conducting a series of studies whose goal was to discover novel endogenous angiogenesis inhibitors, we have purified matrilin-1 (MATN-1) and have demonstrated, for the first time, that it inhibits neovascularization both in vitro and in vivo. Proteins were extracted from cartilage using a 2 m NaCl, 0.01 m HEPES buffer at 4 °C, followed by concentration of the extract. The concentrate was fractionated by size exclusion chromatography, and fractions were then screened for their ability to inhibit capillary endothelial cell (EC) proliferation in vitro. Fractions containing EC inhibitory activity were pooled and further purified by cation exchange chromatography. The resulting fractions from this step were then screened to isolate the antiangiogenic activity in vitro. This activity was identified by tandem mass spectrometry as being MATN-1. Human MATN-1 was cloned and expressed in Pichia pastoris and purified to homogeneity. Purified recombinant MATN-1, along with purified native protein, was shown to inhibit angiogenesis in vivo using the chick chorioallantoic membrane assay by the inhibition of capillary EC proliferation and migration. Finally, using a MATN-1-deficient mouse, we showed that angiogenesis during fracture healing was significantly higher in MATN-1−/− mice compared with the wild type mice as demonstrated by in vivo imaging and by elevated expression of angiogenesis markers including PECAM1, VEGFR, and VE-cadherin. PMID:24692560

  17. Characterization of a Spontaneous Retinal Neovascular Mouse Model

    PubMed Central

    Hasegawa, Eiichi; Sweigard, Harry; Husain, Deeba; Olivares, Ana M.; Chang, Bo; Smith, Kaylee E.; Birsner, Amy E.; D’Amato, Robert J.; Michaud, Norman A.; Han, Yinan; Vavvas, Demetrios G.; Miller, Joan W.; Haider, Neena B.; Connor, Kip M.

    2014-01-01

    Background Vision loss due to vascular disease of the retina is a leading cause of blindness in the world. Retinal angiomatous proliferation (RAP) is a subgroup of neovascular age-related macular degeneration (AMD), whereby abnormal blood vessels develop in the retina leading to debilitating vision loss and eventual blindness. The novel mouse strain, neoretinal vascularization 2 (NRV2), shows spontaneous fundus changes associated with abnormal neovascularization. The purpose of this study is to characterize the induction of pathologic angiogenesis in this mouse model. Methods The NRV2 mice were examined from postnatal day 12 (p12) to 3 months. The phenotypic changes within the retina were evaluated by fundus photography, fluorescein angiography, optical coherence tomography, and immunohistochemical and electron microscopic analysis. The pathological neovascularization was imaged by confocal microscopy and reconstructed using three-dimensional image analysis software. Results We found that NRV2 mice develop multifocal retinal depigmentation in the posterior fundus. Depigmented lesions developed vascular leakage observed by fluorescein angiography. The spontaneous angiogenesis arose from the retinal vascular plexus at postnatal day (p)15 and extended toward retinal pigment epithelium (RPE). By three months of age, histological analysis revealed encapsulation of the neovascular lesion by the RPE in the photoreceptor cell layer and subretinal space. Conclusions The NRV2 mouse strain develops early neovascular lesions within the retina, which grow downward towards the RPE beginning at p15. This retinal neovascularization model mimics early stages of human retinal angiomatous proliferation (RAP) and will likely be a useful in elucidating targeted therapeutics for patients with ocular neovascular disease. PMID:25188381

  18. Molecular mechanisms of epithelial regeneration and neovascularization during healing of gastric and esophageal ulcers.

    PubMed

    Tarnawski, A S; Ahluwalia, A

    2012-01-01

    In this paper we reviewed and updated current views on the cellular and molecular mechanisms of gastric and esophageal ulcer healing. Gastric ulcer healing encompasses inflammation, cell proliferation, epithelial regeneration, gland reconstruction, formation of granulation tissue, neovascularization (new blood vessel formation), interactions between various cells and the matrix and tissue remodeling, resulting in scar formation. All these events are controlled by the cytokines and growth factors, GI hormones including gastrin, CCK, and orexigenic peptides such as ghrelin, orexin-A and obestatin as well as Cox2 generated prostaglandins. These growth factors and hormones trigger cell proliferation, migration, and survival utilizing Ras, MAPK, PI-3K/AKT, PLC-γ and Rho/Rac/actin signaling pathways. Hypoxia triggers activation of some of these genes (e.g., VEGF) via hypoxia inducible factor (HIF). Growth factors: EGF, HGF, IGF-1, their receptors and Cox2 are important for epithelial cell proliferation, migration, re-epithelialization and regeneration of gastric glands during gastric ulcer healing. Serum response factor (SRF) is also essential for re-epithelialization and muscle restoration. VEGF, bFGF, angiopoietins, nitric oxide, endothelin, prostaglandins and metalloproteinases are important for angiogenesis, vascular remodeling and mucosal regeneration within gastric ulcer scar. SRF is critical limiting factor for VEGF-induced angiogenesis. Esophageal ulcer healing follows similar pattern to gastric ulcer, but KGF and its receptor are the key players in regeneration of the epithelium. In addition to local mucosal cells from viable mucosa bordering necrosis, circulating bone marrow derived stem and progenitor cells are potentially important for ulcer healing, contributing to the regeneration of epithelial and connective tissue components and neovascularization. PMID:22300072

  19. Parametric imaging of tumor perfusion and neovascular morphology using ultrasound

    NASA Astrophysics Data System (ADS)

    Hoyt, Kenneth

    2015-03-01

    A new image processing strategy is detailed for the simultaneous measurement of tumor perfusion and neovascular morphology parameters from a sequence of dynamic contrast-enhanced ultrasound (DCE-US) images. A technique for locally mapping tumor perfusion parameters using skeletonized neovascular data is also introduced. Simulated images were used to test the neovascular skeletonization technique and variance (error) of relevant parametric estimates. Preliminary DCE-US image datasets were collected in 6 female patients diagnosed with invasive breast cancer and using a Philips iU22 ultrasound system equipped with a L9-3 MHz transducer and Definity contrast agent. Simulation data demonstrates that neovascular morphology parametric estimation is reproducible albeit measurement error can occur at a lower signal-to-noise ratio (SNR). Experimental results indicate the feasibility of our approach to performing both tumor perfusion and neovascular morphology measurements from DCE-US images. Future work will expand on our initial clinical findings and also extent our image processing strategy to 3-dimensional space to allow whole tumor characterization.

  20. Lack of netrin-4 modulates pathologic neovascularization in the eye

    PubMed Central

    Kociok, Norbert; Crespo-Garcia, Sergio; Liang, Yong; Klein, Sabrina V.; Nürnberg, Christina; Reichhart, Nadine; Skosyrski, Sergej; Moritz, Eva; Maier, Anna-Karina; Brunken, William J.; Strauß, Olaf; Koch, Manuel; Joussen, Antonia M.

    2016-01-01

    Netrins are a family of matrix-binding proteins that function as guidance signals. Netrin-4 displays pathologic roles in tumorigenesis and neovascularization. To answer the question whether netrin-4 acts either pro- or anti-angiogenic, angiogenesis in the retina was assessed in Ntn-4−/− mice with oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (CNV), mimicking hypoxia-mediated neovascularization and inflammatory mediated angiogenesis. The basement membrane protein netrin-4 was found to be localised to mature retinal blood vessels. Netrin-4, but not netrin-1 mRNA expression, increased in response to relative hypoxia and recovered to normal levels at the end of blood vessel formation. No changes in the retina were found in normoxic Ntn-4−/− mice. In OIR, Ntn-4−/− mice initially displayed larger avascular areas which recovered faster to revascularization. Ganzfeld electroretinography showed faster recovery of retinal function in Ntn-4−/− mice. Expression of netrin receptors, Unc5H2 (Unc-5 homolog B, C. elegans) and DCC (deleted in colorectal carcinoma), was found in Müller cells and astrocytes. Laser-induced neovascularization in Nnt-4−/− mice did not differ to that in the controls. Our results indicate a role for netrin-4 as an angiogenesis modulating factor in O2-dependent vascular homeostasis while being less important during normal retinal developmental angiogenesis or during inflammatory neovascularization. PMID:26732856

  1. Promising new treatments for neovascular age-related macular degeneration.

    PubMed

    Michels, Stephan; Schmidt-Erfurth, Ursula; Rosenfeld, Philip J

    2006-07-01

    Angiogenesis, the growth of new blood vessels from existing blood vessels, is responsible for vision loss in a variety of ophthalmic diseases. In neovascular age-related macular degeneration (AMD), the leading cause for legal blindness in many industrialised countries, abnormal blood vessels grow in the macula and cause blindness. There are a number of factors important in the angiogenic cascade but VEGF-A has been implicated in recent years as the major factor responsible for neovascular and exudative diseases of the eye. Numerous antiangiogenic drugs are in development but anti-VEGF drugs have shown great promise in treating neovascular AMD and other ocular diseases, and many of these drugs have been adopted from oncology where antiangiogenic therapy is gaining wide acceptance. For the first time in neovascular AMD, anti-VEGF drugs have brought the hope of vision improvement to a significant proportion of patients. This review provides an overview on angiogenic mechanisms, potential antiangiogenic treatment strategies and different antiangiogenic drugs with special focus on neovascular AMD. PMID:16787141

  2. Statistical segmentation of carotid plaque neovascularization

    NASA Astrophysics Data System (ADS)

    Akkus, Zeynettin; Bosch, Johan G.; Sánchez-Ferrero, Gonzalo V.; Carvalho, Diego D. B.; Renaud, Guillaume; van den Oord, Stijn C. H.; ten Kate, Gerrit L.; Schinkel, Arend F. L.; de Jong, Nico; van der Steen, Antonius F. W.

    2013-03-01

    In several studies, intraplaque neovascularization (IPN) has been linked with plaque vulnerability. The recent development of contrast enhanced ultrasound enables IPN detection, but an accurate quantification of IPN is a big challenge due to noise, motion, subtle contrast response, blooming of contrast and artifacts. We present an algorithm that automatically estimates the location and amount of contrast within the plaque over time. Plaque pixels are initially labeled through an iterative expectation-maximization (EM) algorithm. The used algorithm avoids several drawbacks of standard EM. It is capable of selecting the best number of components in an unsupervised way, based on a minimum message length criterion. Next, neighborhood information using a 5×5 kernel and spatiotemporal behavior are combined with the known characteristics of contrast spots in order to group components, identify artifacts and finalize the classification. Image sequences are divided into 3-seconds subgroups. A pixel is relabeled as an artifact if it is labeled as contrast for more than 1.5 seconds in at least two subgroups. For 10 plaques, automated segmentation results were validated with manual segmentation of contrast in 10 frames per clip. Average Dice index and area ratio were 0.73+/-0.1 (mean+/-SD) and 98.5+/-29.6 (%) respectively. Next, 45 atherosclerotic plaques were analyzed. Time integrated IPN surface area was calculated. Average area of IPN was 3.73+/-3.51 mm2. Average area of 45 plaques was 11.6+/-8.6 mm2. This method based on EM contrast segmentation provides a new way of IPN quantification.

  3. [Cyclocryocoagulation in treatment of neovascular glaucoma].

    PubMed

    Kovacić, Zeljko; Ivanisević, Milan; Rogosić, Veljko; Plavec, Andrea; Karelović, Deni

    2004-01-01

    Neovascular glaucoma (NVG) is a pathological condition of the eye with fast deterioration, accompanied with eyeball pain and loosing sight. The aim of the study was to examine the efficacy of cryotherapy in the treatment of NVG which is resistant to medical and surgical therapy, concerning intraocular pressure (IOT) and eyeball pain immediately after the treatment and 6 months after. In the Department of Ophthalmology, Split University Scool of Medicine, during three years 70 patients with NVG, which were resistant to medical and surgical treatment, were included in the prospective study. There were 50 males and 21 women, average age 74 +/- 6.94 (45-87). The patients were treated with transconjuctival cyclocryocoagulation, machine ERBOKRYIO AE-ERBE was used. The average value of IOT was: at admission 44.8 mmHg, 7 days after the treatment 30.7 mmHg with the tendency of falling down 30 and 90 days later, to finally 19.9 mmHg 180 days after the treatment. The IOT was significantly lower after the treatment. At admission, the average value of eyeball pain intensity was high (4.2), 7 days after the treatment it was 2.1 with the tendency of falling down to finally 1.1 180 days after the treatment. The eyeball pain intensity was significantly lower after the treatment. Cyclocryocoagulation is a method of choice in the treatment of NVG resistant to medical and surgical treatment. Cyclocryocoagulation, as a treatment of noncontrolled progressive NVG, does not have any effect on the improvement of sight in these patient. PMID:15918320

  4. Treatment of choroidal neovascularization in high myopia.

    PubMed

    Montero, Javier A; Ruiz-Moreno, Jose M

    2010-05-01

    High myopia affects approximately 2% of general population, and is a major cause of legal blindness in many developed countries. Choroidal neovascularization (CNV) is the most common vision-threatening complication of high myopia. Different therapeutic approaches have been attempted such as thermal laser photocoagulation, surgery and photodynamic therapy with verteporfin (PDT). The visual outcome of these therapies has been reported to be better than the natural history of the condition. However, the limited visual acuity improvement after PDT monotherapy and the appearance of subretinal fibrosis and chorioretinal atrophy prompted the association of other therapies. In the past few years a tremendous advance in the knowledge of the mechanisms underling CNV secondary to high myopia and age related macular degeneration has been achieved, leading to new therapeutic targets and novel drugs and combined therapies. These new therapeutic weapons have been designed to achieve a selective shut down of choroidal new vessels. Recent reviews have been published on the natural history and therapies for myopic CNV. Ohno-Matsui reported on the natural history of the condition as well as the outcome of laser photocoagulation, surgical extraction of CNV, foveal translocation and photodynamic therapy on myopic CNV in the short-term. Soubrane et al reviewed the new advances on surgery, laser photocoagulation and PDT, considering some of the potential effects of triamcinolone, pegaptanib and ranibizumab in CNV secondary to age related macular degeneration (AMD). Novack et al reported on the pharmacological therapy of CNV in AMD. The aim of this review is to summarize the recent advances in myopic CNV pathophysiology and the new therapeutic targets and drugs that are changing the clinical management of myopic CNV. PMID:20196722

  5. Ischemic retinopathy and neovascular proliferation secondary to severe head injury.

    PubMed

    Coban-Karatas, Muge; Altan-Yaycioglu, Rana

    2014-01-01

    We report a case with severe head trauma and perforating globe injury in one eye and ischemic retinopathy and neovascular proliferation in the other eye. A 37-year-old male was brought to the emergency department after a motor vehicle accident with severe maxillofacial trauma. Ophthalmic examination revealed hematoma of the left eyelids as well as traumatic rupture and disorganization of the left globe. On the right eye, anterior segment and fundoscopic examination were normal. Primary globe repair was performed. At postoperative one-month visit, the right eye revealed no pathology of the optic disc and macula but severe neovascularization in the temporal peripheral retina. The patient was diagnosed as ischemic retinopathy and neovascular proliferation due to head trauma. PMID:25143848

  6. Intrastromal Delivery of Bevacizumab Using Microneedles to Treat Corneal Neovascularization

    PubMed Central

    Kim, Yoo C.; Grossniklaus, Hans E.; Edelhauser, Henry F.; Prausnitz, Mark R.

    2014-01-01

    Purpose. This study tested the hypothesis that highly targeted intrastromal delivery of bevacizumab using coated microneedles allows dramatic dose sparing compared with subconjunctival and topical delivery for treatment of corneal neovascularization. Methods. Stainless steel microneedles 400 μm in length were coated with bevacizumab. A silk suture was placed in the cornea approximately 1 mm from the limbus to induce corneal neovascularization in the eyes of New Zealand white rabbits that were divided into different groups: untreated, microneedle delivery, topical eye drop, and subconjunctival injection of bevacizumab. All drug treatments were initiated 4 days after suture placement and area of neovascularization was measured daily by digital photography for 18 days. Results. Eyes treated once with 4.4 μg bevacizumab using microneedles reduced neovascularization compared with untreated eyes by 44% (day 18). Eyes treated once with 2500 μg bevacizumab using subconjunctival injection gave similar results to microneedle-treated eyes. Eyes treated once with 4.4 μg subconjunctival bevacizumab showed no significant effect compared with untreated eyes. Eyes treated with 52,500 μg bevacizumab by eye drops three times per day for 14 days reduced the neovascularization area compared with untreated eyes by 6% (day 18), which was significantly less effective than the single microneedle treatment. Visual exam and histological analysis showed no observable effect of microneedle treatment on corneal transparency or microanatomical structure. Conclusions. This study shows that microneedles can target drug delivery to corneal stroma in a minimally invasive way and demonstrates effective suppression of corneal neovascularization after suture-induced injury using a much lower dose compared with conventional methods. PMID:25212779

  7. A protocol for a lung neovascularization model in rodents

    PubMed Central

    Jones, Rosemary C; Capen, Diane E; Petersen, Bodil; Jain, Rakesh K; Duda, Dan G

    2009-01-01

    By providing insight into the cellular events of vascular injury and repair, experimental model systems seek to promote timely therapeutic strategies for human disease. The goal of many current studies of neovascularization is to identify cells critical to the process and their role in vascular channel assembly. We propose here a protocol to analyze, in an in vivo rodent model, vessel and capillary remodeling (reorganization and growth) in the injured lung. Sequential analyses of stages in the assembly of vascular structures, and of relevant cell types, provide further opportunities to study the molecular and cellular determinants of lung neovascularization. PMID:18323809

  8. Clinical correlates of common corneal neovascular diseases: a literature review

    PubMed Central

    Abdelfattah, Nizar Saleh; Amgad, Mohamed; Zayed, Amira A; Salem, Hamdy; Elkhanany, Ahmed E; Hussein, Heba; Abd El-Baky, Nawal

    2015-01-01

    A large subset of corneal pathologies involves the formation of new blood and lymph vessels (neovascularization), leading to compromised visual acuity. This article aims to review the clinical causes and presentations of corneal neovascularization (CNV) by examining the mechanisms behind common CNV-related corneal pathologies, with a particular focus on herpes simplex stromal keratitis, contact lenses-induced keratitis and CNV secondary to keratoplasty. Moreover, we reviewed CNV in the context of different types of corneal transplantation and keratoprosthesis, and summarized the most relevant treatments available so far. PMID:25709930

  9. Endothelial Progenitor Cells in Sprouting Angiogenesis: Proteases Pave the Way.

    PubMed

    Laurenzana, A; Fibbi, G; Margheri, F; Biagioni, A; Luciani, C; Del Rosso, M; Chillà, A

    2015-01-01

    Sprouting angiogenesis consists of the expansion and remodelling of existing vessels, where the vascular sprouts connect each other to form new vascular loops. Endothelial Progenitor Cells (EPCs) are a subtype of stem cells, with high proliferative potential, able to differentiate into mature Endothelial Cells (ECs) during the neovascularization process. In addition to this direct structural role EPCs improve neovascularization, also secreting numerous pro-angiogenic factors able to enhance the proliferation, survival and function of mature ECs, and other surrounding progenitor cells. While sprouting angiogenesis by mature ECs involves resident ECs, the vasculogenic contribution of EPCs is a high hurdle race. Bone marrowmobilized EPCs have to detach from the stem cell niche, intravasate into bone marrow vessels, reach the hypoxic area or tumour site, extravasate and incorporate into the new vessel lumen, thus complementing the resident mature ECs in sprouting angiogenesis. The goal of this review is to highlight the role of the main protease systems able to control each of these steps. The pivotal protease systems here described, involved in vascular patterning in sprouting angiogenesis, are the matrix-metalloproteinases (MMPs), the serineproteinases urokinase-type plasminogen activator (uPA) associated with its receptor (uPAR) and receptorassociated plasminogen/plasmin, the neutrophil elastase and the cathepsins. Since angiogenesis plays a critical role not only in physiological but also in pathological processes, such as in tumours, controlling the contribution of EPCs to the angiogenic process, through the regulation of the protease systems involved, could yield new opportunities for the therapeutic prospect of efficient control of pathological angiogenesis. PMID:26321757

  10. Radiation therapy for neovascular age-related macular degeneration

    PubMed Central

    Petrarca, Robert; Jackson, Timothy L

    2011-01-01

    Antivascular endothelial growth factor (anti-VEGF) therapies represent the standard of care for most patients presenting with neovascular (wet) age-related macular degeneration (neovascular AMD). Anti-VEGF drugs require repeated injections and impose a considerable burden of care, and not all patients respond. Radiation targets the proliferating cells that cause neovascular AMD, including fibroblastic, inflammatory, and endothelial cells. Two new neovascular AMD radiation treatments are being investigated: epimacular brachytherapy and stereotactic radiosurgery. Epimacular brachytherapy uses beta radiation, delivered to the lesion via a pars plana vitrectomy. Stereotactic radiosurgery uses low voltage X-rays in overlapping beams, directed onto the lesion. Feasibility data for epimacular brachytherapy show a greatly reduced need for anti-VEGF therapy, with a mean vision gain of 8.9 ETDRS letters at 12 months. Pivotal trials are underway (MERLOT, CABERNET). Preliminary stereotactic radiosurgery data suggest a mean vision gain of 8 to 10 ETDRS letters at 12 months. A large randomized sham controlled stereotactic radiosurgery feasibility study is underway (CLH002), with pivotal trials to follow. While it is too early to conclude on the safety and efficacy of epimacular brachytherapy and stereotactic radiosurgery, preliminary results are positive, and these suggest that radiation offers a more durable therapeutic effect than intraocular injections. PMID:21311657

  11. Regulation of Tumor Angiogenesis and Choroidal Neovascularization by Endogenous Angioinhibitors

    PubMed Central

    Gunda, Venugopal; Sudhakar, Yakkanti A

    2014-01-01

    Angiogenesis is the process of neovascularization from parent blood vessels, which is a prerequisite for many physiological and pathological conditions and is regulated by a balance between endogenous angioinhibitors and angioactivators or angiogenic factors. Imbalance between angioinhibitors and angioactivators is associated with neovascularization capacity during progression of tumor development and Choroidal Neovascularization (CNV). Normalization of pathological angiogenesis is considered as an alternative strategy to prevent the tumor growth in cancer progression or retinal damage in CNV. Various angioinhibitors are being identified and evaluated for their pathological angiogenesis regulation, of which endogenous angioinhibitors are one class derived either from extra cellular matrix or from non-extra cellular matrix of human origin. Endogenous angioinhibitors are gaining much significance as they interact with proliferating endothelial cells by binding to distinct integrins and non-integrin receptors, regulating different intracellular signaling mechanisms leading to inhibition of choroidal neovascularization and tumor growth. This review will focus on endogenous angioinhibitors and their receptor(s) mediated angioinhibitory signaling, which are of major concern in angiogenesis and their clinical and pharmaceutical implications. PMID:25258675

  12. Broad Spectrum Antiangiogenic Treatment for Ocular Neovascular Diseases

    PubMed Central

    Benny, Ofra; Nakai, Kei; Yoshimura, Takeru; Bazinet, Lauren; Akula, James D.; Nakao, Shintaro; Hafezi-Moghadam, Ali; Panigrahy, Dipak; Pakneshan, Pouya; D'Amato, Robert J.

    2010-01-01

    Pathological neovascularization is a hallmark of late stage neovascular (wet) age-related macular degeneration (AMD) and the leading cause of blindness in people over the age of 50 in the western world. The treatments focus on suppression of choroidal neovascularization (CNV), while current approved therapies are limited to inhibiting vascular endothelial growth factor (VEGF) exclusively. However, this treatment does not address the underlying cause of AMD, and the loss of VEGF's neuroprotective can be a potential side effect. Therapy which targets the key processes in AMD, the pathological neovascularization, vessel leakage and inflammation could bring a major shift in the approach to disease treatment and prevention. In this study we have demonstrated the efficacy of such broad spectrum antiangiogenic therapy on mouse model of AMD. Methods and Findings Lodamin, a polymeric formulation of TNP-470, is a potent broad-spectrum antiangiogenic drug. Lodamin significantly reduced key processes involved in AMD progression as demonstrated in mice and rats. Its suppressive effects on angiogenesis, vascular leakage and inflammation were studied in a wide array of assays including; a Matrigel, delayed-type hypersensitivity (DTH), Miles assay, laser-induced CNV and corneal micropocket assay. Lodamin significantly suppressed the secretion of various pro-inflammatory cytokines in the CNV lesion including monocyte chemotactic protein-1 (MCP-1/Ccl2). Importantly, Lodamin was found to regress established CNV lesions, unlike soluble fms-like tyrosine kinase-1 (sFlk-1). The drug was found to be safe in mice and have little toxicity as demonstrated by electroretinography (ERG) assessing retinal and by histology. Conclusions Lodamin, a polymer formulation of TNP-470, was identified as a first in its class, broad-spectrum antiangiogenic drug that can be administered orally or locally to treat corneal and retinal neovascularization. Several unique properties make Lodamin especially

  13. Endothelial progenitor cells promote tumor growth and progression by enhancing new vessel formation

    PubMed Central

    Zhao, Xin; Liu, Huan-Qiu; Li, Ji; Liu, Xiao-Liang

    2016-01-01

    Tumor growth and progression require new blood vessel formation to deliver nutrients and oxygen for further cell proliferation and to create a neovascular network exit for tumor cell metastasis. Endothelial progenitor cells (EPCs) are a bone marrow (BM)-derived stem cell population that circulates in the peripheral circulation and homes to the tumor bed to participate in new blood vessel formation. In addition to structural support to nascent vessels, these cells can also regulate the angiogenic process by paracrine secretion of a number of proangiogenic growth factors and cytokines, thus playing a crucial role in tumor neovascularization and development. Inhibition of EPC-mediated new vessel formation may be a promising therapeutic strategy in tumor treatment. EPC-mediated neovascularization is a complex process that includes multiple steps and requires a series of cytokines and modulators, thus understanding the underlying mechanisms may provide anti-neovasculogenesis targets that may be blocked for the prevention of tumor development. The present review stresses the process and contribution of EPCs to the formation of new blood vessels in solid tumors, in an attempt to gain an improved understanding of the underlying cellular and molecular mechanisms involved, and to provide a potential effective therapeutic target for cancer treatment. PMID:27446353

  14. Neovascular glaucoma in a child: an unusual presentation of medulloepithelioma

    PubMed Central

    Kassa, Enoch; Li, Helen; Sun, Yang

    2014-01-01

    A healthy 12 month old infant without significant medical history presented with left eye redness for one week. Ophthalmic examination showed elevated intraocular pressure with iris neovascularization in the affected eye with increased optic nerve cupping. Scleral depression revealed a ciliary body mass in the supratemporal quadrant. A large, non-pigmented, vascular mass was noted; biopsy results showed multilayered cords, tubules, and sheets resembling primitive medullary epithelium arising from the ciliary body. The patient was diagnosed with medulloepithelioma. The patient underwent enucleation of the affected eye. Medulloepithelioma is a rare but important cause of neovascular glaucoma in the pediatric population. This case will focus on the characteristics of medulloepthelioma and the differential diagnosis for a non-pigmented ciliary body mass in a child.

  15. Treatment of neovascular age-related macular degeneration: Current therapies

    PubMed Central

    Augustin, Albert J; Scholl, Stefan; Kirchhof, Janna

    2009-01-01

    Choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) is now the leading cause of blindness and severe vision loss among people over the age of 40 in the Western world. Its prevalence is certain to increase substantially as the population ages. Treatments currently available for the disease include laser photocoagulation, verteporfin photodynamic therapy, and intravitreal injections of corticosteroids and anti-angiogenic agents. Many studies have reported the benefits of each of these treatments, although none is without its risks. No intervention actually cures AMD, nor the neovascularization associated with it. However, its symptoms are treated with varying degrees of success. Some treatments stabilize or arrest the progress of the disease. Others have been shown to reverse some of the damage that has already been done. These treatments can even lead to visual improvement. This paper will review the major classes of drugs and therapies designed to treat this condition. PMID:19668562

  16. TRAIL-deficient mice exhibit delayed regression of retinal neovascularization.

    PubMed

    Hubert, Kristin E; Davies, Michael H; Stempel, Andrew J; Griffith, Thomas S; Powers, Michael R

    2009-12-01

    While it is well established that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in various cell types, the role of TRAIL in regulation of retinal neovascularization (NV) has not been described. Here we determined the role of TRAIL in retinal NV during oxygen-induced retinopathy using TRAIL deficient ((-/-)) mice. TRAIL and its receptor, DR5, were expressed in wild-type retinas at all time points evaluated (postnatal days 12, 17, 21, 24) during oxygen-induced retinopathy and in age-matched room air control animals. Localization of TRAIL(+) cells within the neovascular tufts of hyperoxia- exposed wild-type mice suggested TRAIL plays a role in oxygen-induced retinopathy. Retinal vascular development appeared normal in the TRAIL(-/-) mice, except for a small but significant difference in the capillary-free zone surrounding major arteries. A minimal difference in avascularity was observed at postnatal day 12 in the retinas of TRAIL(-/-) mice after hyperoxia-exposure compared with wild-type mice, suggesting that TRAIL does not play a major role in the vaso-obliterative phase of oxygen-induced retinopathy. However, at the peak of NV, TRAIL(-/-) mice had a significant increase in retinal neovascularization. In addition, when NV naturally regresses in wild-type mice, TRAIL(-/-) mice continued to display significantly high levels of NV. This was attributed to a significant decrease in neovascular tuft cells undergoing apoptosis in TRAIL(-/-) mice. Together, these data strongly suggest that TRAIL plays a role in the control of retinal NV. PMID:19893042

  17. A new role for cofilin in retinal neovascularization.

    PubMed

    Kumar, Raj; Janjanam, Jagadeesh; Singh, Nikhlesh K; Rao, Gadiparthi N

    2016-03-15

    Pak1 plays an important role in several cellular processes, including cell migration, but its role in pathological angiogenesis is not known. Here, we have determined its role in pathological retinal angiogenesis using an oxygen-induced retinopathy (OIR) model. VEGFA induced phosphorylation of Pak1 and its effector cofilin in a manner that was dependent on time as well as p38MAPKβ (also known as MAPK11) in human retinal microvascular endothelial cells (HRMVECs). Depletion of the levels of any of these molecules inhibited VEGFA-induced HRMVEC F-actin stress fiber formation, migration, proliferation, sprouting and tube formation. In accordance with these observations, hypoxia induced Pak1 and cofilin phosphorylation with p38MAPKβ being downstream to Pak1 and upstream to cofilin in mouse retina. Furthermore, Pak1 deficiency abolished hypoxia-induced p38MAPKβ and cofilin phosphorylation and abrogated retinal endothelial cell proliferation, tip cell formation and neovascularization. In addition, small interfering RNA (siRNA)-mediated downregulation of p38MAPKβ or cofilin levels in the wild-type mouse retina also diminished endothelial cell proliferation, tip cell formation and neovascularization. Taken together, these observations suggest that, although the p38MAPKβ-Pak1-cofilin axis is required for HRMVEC migration, proliferation, sprouting and tubulogenesis, Pak1-p38MAPKβ-cofilin signaling is also essential for hypoxia-induced mouse retinal endothelial cell proliferation, tip cell formation and neovascularization. PMID:26857814

  18. Secondary glaucoma in CAPN5-associated neovascular inflammatory vitreoretinopathy

    PubMed Central

    Cham, Abdourahman; Bansal, Mayank; Banda, Himanshu K; Kwon, Young; Tlucek, Paul S; Bassuk, Alexander G; Tsang, Stephen H; Sobol, Warren M; Folk, James C; Yeh, Steven; Mahajan, Vinit B

    2016-01-01

    Objective The objective of this study was to review the treatment outcomes of patients with secondary glaucoma in cases of autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV), a hereditary autoimmune uveitis due to mutations in CAPN5. Patients and methods A retrospective, observational case series was assembled from ADNIV patients with secondary glaucoma. The main outcome measures were intraocular pressure (IOP), visual acuity, use of antiglaucoma medications, ocular surgeries, and adverse outcomes. Perimetry and optic disk optical coherence tomography (OCT) were also analyzed. Results Nine eyes of five ADNIV patients with secondary glaucoma were reviewed. Each received a fluocinolone acetonide (FA) implant for the management of posterior uveitis. Following implantation, no eyes developed neovascular glaucoma. Five eyes (in patients 1, 2, and 5) required Ahmed glaucoma valve surgery for the management of steroid-responsive glaucoma. Patient 2 also developed angle closure with iris bombe and underwent laser peripheral iridotomy. Patient 4 had both hypotony and elevated IOP that required periodic antiglaucoma medication in the FA-implanted eye. Patient 3 did not develop steroid-response glaucoma in either eye. Optic disk examinations were obscured by fibrosis and better assessed with OCT. Conclusion ADNIV patients show combined mechanism secondary glaucoma best assessed by OCT of the optic disk. The FA implants have reduced uveitic and neovascular glaucoma. Nevertheless, IOP management remains complex due to steroid-response glaucoma, angle closure glaucoma, and hypotony. PMID:27390515

  19. Characterization of a Mouse Model of Hyperglycemia and Retinal Neovascularization

    PubMed Central

    Rakoczy, Elizabeth P.; Rahman, Ireni S. Ali; Binz, Nicolette; Li, Cai-Rui; Vagaja, Nermina N.; de Pinho, Marisa; Lai, Chooi-May

    2010-01-01

    One of the limitations of research into diabetic retinopathy is the lack of suitable animal models. To study how the two important factors—hyperglycemia and vascular endothelial growth factor—interact in diabetic retinopathy, the Akimba mouse (Ins2AkitaVEGF+/−) was generated by crossing the Akita mouse (Ins2Akita) with the Kimba mouse (VEGF+/+). C57Bl/6 and the parental and Akimba mouse lines were characterized by biometric measurements, histology, immunohistochemistry, and Spectralis Heidelberg retinal angiography and optical coherence tomography. The Akimba line not only retained the characteristics of the parental strains, such as developing hyperglycemia and retinal neovascularization, but developed higher blood glucose levels at a younger age and had worse kidney-body weight ratios than the Akita line. With aging, the Akimba line demonstrated enhanced photoreceptor cell loss, thinning of the retina, and more severe retinal vascular pathology, including more severe capillary nonperfusion, vessel constriction, beading, neovascularization, fibroses, and edema, compared with the Kimba line. The vascular changes were associated with major histocompatibility complex class II+ cellular staining throughout the retina. Together, these observations suggest that hyperglycemia resulted in higher prevalences of edema and exacerbated the vascular endothelial growth factor-driven neovascular and retinal changes in the Akimba line. Thus, the Akimba line could become a useful model for studying the interplay between hyperglycemia and vascular endothelial growth factor and for testing treatment strategies for potentially blinding complications, such as edema. PMID:20829433

  20. Assessment of therapeutic options for reducing alkali burn-induced corneal neovascularization and inflammation.

    PubMed

    Bakunowicz-Łazarczyk, Alina; Urban, Beata

    2016-03-01

    This article aims to review and provide the current knowledge of the possibilities of topical treatment of corneal neovascularization due to alkali burns, evidenced by laboratory experiments, in vitro studies, and clinical trials published in the specialized literature. Authors present clinically relevant treatment of corneal neovascularization used in clinical practice, potential antiangiogenic topical therapeutics against corneal neovascularization, which are under investigation, and anti-angiogenic gene-therapy. PMID:26651127

  1. Retinal and vitreal neovascularization in retinopathy of prematurity. A scanning electron microscopic study in the kitten.

    PubMed

    Yoneya, S; Tso, M O

    1991-12-01

    The angioarchitecture of vitreal and retinal neovascularizations produced experimentally in the eyes of kittens aged 2 to 9 weeks was studied with scanning electron microscopy. Various forms of new retinal and vitreal vessels were observed depending on topographic locations. Intraretinal neovascularization was observed at the retinal periphery as it grew toward the avascular zone in forms of short vascular buds, aneurysmal outgrowths, and neovascular loops. Posterior or to this frond of neovascularization, intertwining intraretinal telangiectasia was observed. At the posterior pole, capillaries with microaneurysms extended posteriorly toward the deeper layers of the retina from the vascular trunks at the nerve fiber layer. Vitreal neovascularization broke through the internal limiting membrane and exhibited aneurysmal outgrowths, clusters of glomerular swellings, and sinusoidal vascular channels. At the optic disc, vitreous neovascularization took the form of aneurysmal outgrowths and long vascular buds. Vitreal neovascularization showed different characteristics from the intraretinal neovascularization. We hypothesize that the topographic variation of the angioarchitecture of retinal and vitreal neovascularizations depends on the maturity of the vessels and might be related to the hemodynamics at each site. PMID:1726774

  2. Apelin Is Required for Non-Neovascular Remodeling in the Retina

    PubMed Central

    McKenzie, Jenny A.G.; Fruttiger, Marcus; Abraham, Sabu; Lange, Clemens A.K.; Stone, Jay; Gandhi, Pranita; Wang, Xiaomeng; Bainbridge, James; Moss, Stephen E.; Greenwood, John

    2012-01-01

    Retinal pathologies are frequently accompanied by retinal vascular responses, including the formation of new vessels by angiogenesis (neovascularization). Pathological vascular changes may also include less well characterized traits of vascular remodeling that are non-neovascular, such as vessel pruning and the emergence of dilated and tortuous vessel phenotypes (telangiectasis). The molecular mechanisms underlying neovascular growth versus non-neovascular remodeling are poorly understood. We therefore undertook to identify novel regulators of non-neovascular remodeling in the retina by using the dystrophic Royal College of Surgeons (RCS) rat and the retinal dystrophy 1 (RD1) mouse, both of which display pronounced non-neovascular remodeling. Gene expression profiling of isolated retinal vessels from these mutant rodent models and wild-type controls revealed 60 differentially expressed genes. These included the genes for apelin (Apln) and for its receptor (Aplnr), both of which were strongly up-regulated in the mutants. Crossing RD1 mice into an Apln-null background substantially reduced vascular telangiectasia. In contrast, Apln gene deletion had no effect in two models of neovascular pathology [laser-induced choroidal neovascularization and the very low density lipoprotein receptor (Vldlr)-knockout mouse]. These findings suggest that in these models apelin has minimal effect on sprouting retinal angiogenesis, but contributes significantly to pathogenic non-neovascular remodeling. PMID:22067912

  3. Sox2 in the differentiation of cochlear progenitor cells

    PubMed Central

    Kempfle, Judith S.; Turban, Jack L.; Edge, Albert S. B.

    2016-01-01

    HMG domain transcription factor, Sox2, is a critical gene for the development of cochlear hair cells, the receptor cells for hearing, but this has been ascribed to expansion of the progenitors that become hair cells. Here, we show that Sox2 activated Atoh1, a transcription factor important for hair cell differentiation, through an interaction with the 3′ enhancer of Atoh1. Binding to consensus sequences in the Atoh1 enhancer was dependent on the level of Sox2, and the extent of enhancer binding correlated to the extent of activation. Atoh1 activation by Sox2 was required for embryonic hair cell development: deletion of Sox2 in an inducible mutant, even after progenitor cells were fully established, halted development of hair cells, and silencing also inhibited postnatal differentiation of hair cells induced by inhibition of γ-secretase. Sox2 is thus required in the cochlea to both expand the progenitor cells and initiate their differentiation to hair cells. PMID:26988140

  4. Sox2 in the differentiation of cochlear progenitor cells.

    PubMed

    Kempfle, Judith S; Turban, Jack L; Edge, Albert S B

    2016-01-01

    HMG domain transcription factor, Sox2, is a critical gene for the development of cochlear hair cells, the receptor cells for hearing, but this has been ascribed to expansion of the progenitors that become hair cells. Here, we show that Sox2 activated Atoh1, a transcription factor important for hair cell differentiation, through an interaction with the 3' enhancer of Atoh1. Binding to consensus sequences in the Atoh1 enhancer was dependent on the level of Sox2, and the extent of enhancer binding correlated to the extent of activation. Atoh1 activation by Sox2 was required for embryonic hair cell development: deletion of Sox2 in an inducible mutant, even after progenitor cells were fully established, halted development of hair cells, and silencing also inhibited postnatal differentiation of hair cells induced by inhibition of γ-secretase. Sox2 is thus required in the cochlea to both expand the progenitor cells and initiate their differentiation to hair cells. PMID:26988140

  5. Cytochrome P450-generated metabolites derived from ω-3 fatty acids attenuate neovascularization

    PubMed Central

    Yanai, Ryoji; Mulki, Lama; Hasegawa, Eiichi; Takeuchi, Kimio; Sweigard, Harry; Suzuki, Jun; Gaissert, Philipp; Vavvas, Demetrios G.; Sonoda, Koh-Hei; Rothe, Michael; Schunck, Wolf-Hagen; Miller, Joan W.; Connor, Kip M.

    2014-01-01

    Ocular neovascularization, including age-related macular degeneration (AMD), is a primary cause of blindness in individuals of industrialized countries. With a projected increase in the prevalence of these blinding neovascular diseases, there is an urgent need for new pharmacological interventions for their treatment or prevention. Increasing evidence has implicated eicosanoid-like metabolites of long-chain polyunsaturated fatty acids (LCPUFAs) in the regulation of neovascular disease. In particular, metabolites generated by the cytochrome P450 (CYP)–epoxygenase pathway have been shown to be potent modulators of angiogenesis, making this pathway a reasonable previously unidentified target for intervention in neovascular ocular disease. Here we show that dietary supplementation with ω-3 LCPUFAs promotes regression of choroidal neovessels in a well-characterized mouse model of neovascular AMD. Leukocyte recruitment and adhesion molecule expression in choroidal neovascular lesions were down-regulated in mice fed ω-3 LCPUFAs. The serum of these mice showed increased levels of anti-inflammatory eicosanoids derived from eicosapentaenoic acid and docosahexaenoic acid. 17,18-epoxyeicosatetraenoic acid and 19,20-epoxydocosapentaenoic acid, the major CYP-generated metabolites of these primary ω-3 LCPUFAs, were identified as key lipid mediators of disease resolution. We conclude that CYP-derived bioactive lipid metabolites from ω-3 LCPUFAs are potent inhibitors of intraocular neovascular disease and show promising therapeutic potential for resolution of neovascular AMD. PMID:24979774

  6. Current and emerging treatment options for myopic choroidal neovascularization.

    PubMed

    El Matri, Leila; Chebil, Ahmed; Kort, Fedra

    2015-01-01

    Choroidal neovascularization (CNV) is the main cause of visual impairment in highly myopic patients younger than 50 years of age. There are different treatments for myopic CNV (mCNV), with 5- to 10-year outcomes currently. Chorioretinal atrophy is still the most important determinant factor for visual outcome. The purpose of this study is to provide an overview of the current treatments for mCNV, including laser, surgical management, verteporfin photodynamic therapy, and mainly anti-vascular endothelial growth factor therapy. Emerging treatment options are also discussed. PMID:25987831

  7. Current and emerging treatment options for myopic choroidal neovascularization

    PubMed Central

    El Matri, Leila; Chebil, Ahmed; Kort, Fedra

    2015-01-01

    Choroidal neovascularization (CNV) is the main cause of visual impairment in highly myopic patients younger than 50 years of age. There are different treatments for myopic CNV (mCNV), with 5- to 10-year outcomes currently. Chorioretinal atrophy is still the most important determinant factor for visual outcome. The purpose of this study is to provide an overview of the current treatments for mCNV, including laser, surgical management, verteporfin photodynamic therapy, and mainly anti-vascular endothelial growth factor therapy. Emerging treatment options are also discussed. PMID:25987831

  8. Automated choroidal neovascularization detection algorithm for optical coherence tomography angiography

    PubMed Central

    Liu, Li; Gao, Simon S.; Bailey, Steven T.; Huang, David; Li, Dengwang; Jia, Yali

    2015-01-01

    Optical coherence tomography angiography has recently been used to visualize choroidal neovascularization (CNV) in participants with age-related macular degeneration. Identification and quantification of CNV area is important clinically for disease assessment. An automated algorithm for CNV area detection is presented in this article. It relies on denoising and a saliency detection model to overcome issues such as projection artifacts and the heterogeneity of CNV. Qualitative and quantitative evaluations were performed on scans of 7 participants. Results from the algorithm agreed well with manual delineation of CNV area. PMID:26417524

  9. Role of liver progenitors in liver regeneration

    PubMed Central

    Best, Jan; Manka, Paul; Syn, Wing-Kin; Dollé, Laurent; van Grunsven, Leo A.

    2015-01-01

    During massive liver injury and hepatocyte loss, the intrinsic regenerative capacity of the liver by replication of resident hepatocytes is overwhelmed. Treatment of this condition depends on the cause of liver injury, though in many cases liver transplantation (LT) remains the only curative option. LT for end stage chronic and acute liver diseases is hampered by shortage of donor organs and requires immunosuppression. Hepatocyte transplantation is limited by yet unresolved technical difficulties. Since currently no treatment is available to facilitate liver regeneration directly, therapies involving the use of resident liver stem or progenitor cells (LPCs) or non-liver stem cells are coming to fore. LPCs are quiescent in the healthy liver, but may be activated under conditions where the regenerative capacity of mature hepatocytes is severely impaired. Non-liver stem cells include embryonic stem cells (ES cells) and mesenchymal stem cells (MSCs). In the first section, we aim to provide an overview of the role of putative cytokines, growth factors, mitogens and hormones in regulating LPC response and briefly discuss the prognostic value of the LPC response in clinical practice. In the latter section, we will highlight the role of other (non-liver) stem cells in transplantation and discuss advantages and disadvantages of ES cells, induced pluripotent stem cells (iPS), as well as MSCs. PMID:25713804

  10. In vivo corneal neovascularization imaging by optical-resolution photoacoustic microscopy

    PubMed Central

    Liu, Wenzhong; Schultz, Kathryn M.; Zhang, Kevin; Sasman, Amy; Gao, Fengli; Kume, Tsutomu; Zhang, Hao F.

    2014-01-01

    Corneal neovascularization leads to blurred vision, thus in vivo visualization is essential for pathological studies in animal models. Photoacoustic (PA) imaging can delineate microvasculature and hemodynamics noninvasively, which is suitable for investigating corneal neovascularization. In this study, we demonstrate in vivo imaging of corneal neovascularization in the mouse eye by optical-resolution photoacoustic microscopy (OR-PAM), where corneal neovascularization is induced by deliberate alkali burn injuries in C57BL6/J inbred mice corneas on the left eye. We used OR-PAM to image five mice with corneal alkali burn injuries; the uninjured eyes (right eye) in these mice are then used as the controls. Corneal images acquired by OR-PAM with and without alkali burn injury are compared, clear signs of corneal neovascularization are present in the OR-PAM images of injured eyes; the OR-PAM results are also confirmed by postmortem fluorescence-labeled confocal microscopy. PMID:25013754

  11. Macrophage polarization in experimental and clinical choroidal neovascularization

    PubMed Central

    Yang, Yu; Liu, Fang; Tang, Miao; Yuan, Miner; Hu, Andina; Zhan, Zongyi; Li, Zijing; Li, Jiaqing; Ding, Xiaoyan; Lu, Lin

    2016-01-01

    Macrophages play an important role in the development of age-related macular degeneration (AMD). In this study, the spatial and temporal changes and the polarization of macrophages in murine laser-induced choroidal neovascularization (CNV) were investigated, and the polarized M1 and M2 biomarkers in the aqueous humors of neovascular AMD (nAMD) patients were studied. Macrophages, the main infiltrating inflammatory cells in CNV lesions, were evidenced by a significant increase in F4/80 mRNA expression and by the infiltration of F4/80+ cells in the lesions and the vicinity of laser-induced CNV. The mRNA expressions of M1-related markers were dramatically upregulated in the early stage, while the M2-related markers were slightly upregulated in the middle stage and sustained until the late stage. The results of immunostaining showed a similar early-but-transient M1 pattern and a delayed-but-sustained M2 pattern in laser-induced CNV. In addition, a higher M2/M1 ratio was found in both the murine models (Arg-1/iNOS and CCL22/CXCL10) and the aqueous humors of nAMD patients (CCL22/CXCL10) than in the controls. Our results suggested that the dynamic patterns of M1 and M2 were different in both the experimental and clinical CNV. The M2 macrophages were predominant and may play a more important role in the development of CNV. PMID:27489096

  12. Prognostic Factor Analysis of Intraocular Pressure with Neovascular Glaucoma.

    PubMed

    Nakano, Satoko; Nakamuro, Takako; Yokoyama, Katsuhiko; Kiyosaki, Kunihiro; Kubota, Toshiaki

    2016-01-01

    Purpose. To perform multivariate analysis for identifying independent predictors of elevated intraocular pressure (IOP) with neovascular glaucoma (NVG), including antivascular endothelial growth factor (VEGF) intravitreal injections. Methods. We retrospectively reviewed 142 NVG patients (181 eyes) with ischemic retinal diseases [proliferative diabetic retinopathy (PDR) in 134 eyes, retinal vein occlusion (RVO) in 29, and ocular ischemic syndrome in 18]. We analyzed age, gender, initial/final LogMAR VA, initial/final IOP, extent of iris and/or angle neovascularization, treatments, preexisting complications, concurrent medications, and follow-up duration. Results. The mean follow-up duration was 23.8 ± 18.8 months. At the final follow-up, 125 (72.3%) eyes had IOP ≤ 21 mmHg. NVG patients with RVO had a higher degree of angle closure and higher IOP. NVG with PDR had better IOP and LogMAR VA. Angle closure had the greatest impact on final IOP. Greater than 90% of patients treated with trabeculectomy with mitomycin C (LEC) had persistent declines in IOP (≤21 mmHg). Stand-alone and combination anti-VEGF therapies were not associated with improved long-term prognosis of IOP. Conclusions. Angle closure was found to have the greatest effect on NVG-IOP prognosis. When target IOP values are not obtained after adequate PRP with or without anti-VEGF, early LEC may improve the prognosis of IOP. PMID:27579175

  13. Prognostic Factor Analysis of Intraocular Pressure with Neovascular Glaucoma

    PubMed Central

    Nakamuro, Takako; Yokoyama, Katsuhiko; Kiyosaki, Kunihiro

    2016-01-01

    Purpose. To perform multivariate analysis for identifying independent predictors of elevated intraocular pressure (IOP) with neovascular glaucoma (NVG), including antivascular endothelial growth factor (VEGF) intravitreal injections. Methods. We retrospectively reviewed 142 NVG patients (181 eyes) with ischemic retinal diseases [proliferative diabetic retinopathy (PDR) in 134 eyes, retinal vein occlusion (RVO) in 29, and ocular ischemic syndrome in 18]. We analyzed age, gender, initial/final LogMAR VA, initial/final IOP, extent of iris and/or angle neovascularization, treatments, preexisting complications, concurrent medications, and follow-up duration. Results. The mean follow-up duration was 23.8 ± 18.8 months. At the final follow-up, 125 (72.3%) eyes had IOP ≤ 21 mmHg. NVG patients with RVO had a higher degree of angle closure and higher IOP. NVG with PDR had better IOP and LogMAR VA. Angle closure had the greatest impact on final IOP. Greater than 90% of patients treated with trabeculectomy with mitomycin C (LEC) had persistent declines in IOP (≤21 mmHg). Stand-alone and combination anti-VEGF therapies were not associated with improved long-term prognosis of IOP. Conclusions. Angle closure was found to have the greatest effect on NVG-IOP prognosis. When target IOP values are not obtained after adequate PRP with or without anti-VEGF, early LEC may improve the prognosis of IOP. PMID:27579175

  14. Vascular Guidance: Microstructural Scaffold Patterning for Inductive Neovascularization

    PubMed Central

    Muller, Daniel; Chim, Harvey; Bader, Augustinus; Whiteman, Matthew; Schantz, Jan-Thorsten

    2011-01-01

    Current tissue engineering techniques are limited by inadequate vascularisation and perfusion of cell-scaffold constructs. Microstructural patterning through biomimetic vascular channels within a polymer scaffold might induce neovascularization, allowing fabrication of large engineered constructs. The network of vascular channels within a frontal-parietal defect in a patient, originating from the anterior branch of the middle meningeal artery, was modeled using computer-aided design (CAD) techniques and subsequently incorporated into polycaprolactone (PCL) scaffolds fabricated using fused deposition modeling (FDM). Bone marrow-derived mesenchymal stem cells (MSCs) were seeded onto the scaffolds and implanted into a rat model, with an arteriovenous bundle inserted at the proximal extent of the vascular network. After 3 weeks, scaffolds were elevated as a prefabricated composite tissue-polymer flap and transferred using microsurgical technique. Histological examination of explanted scaffolds revealed vascular ingrowth along patterned channels, with abundant capillary and connective tissue formation throughout experimental scaffolds, while control scaffolds showed only granulation tissue. All prefabricated constructs transferred as free flaps survived and were viable. We term this concept “vascular guidance,” whereby neovascularization is guided through customized channels in a scaffold. Our technique might potentially allow fabrication of much larger tissue-engineered constructs than current technologies allow, as well as allowing tailored construct fabrication with a patient-specific vessel network based on CT scan data and CAD technology. PMID:21188080

  15. Functional Blood Progenitor Markers in Developing Human Liver Progenitors.

    PubMed

    Goldman, Orit; Cohen, Idan; Gouon-Evans, Valerie

    2016-08-01

    In the early fetal liver, hematopoietic progenitors expand and mature together with hepatoblasts, the liver progenitors of hepatocytes and cholangiocytes. Previous analyses of human fetal livers indicated that both progenitors support each other's lineage maturation and curiously share some cell surface markers including CD34 and CD133. Using the human embryonic stem cell (hESC) system, we demonstrate that virtually all hESC-derived hepatoblast-like cells (Hep cells) transition through a progenitor stage expressing CD34 and CD133 as well as GATA2, an additional hematopoietic marker that has not previously been associated with human hepatoblast development. Dynamic expression patterns for CD34, CD133, and GATA2 in hepatoblasts were validated in human fetal livers collected from the first and second trimesters of gestation. Knockdown experiments demonstrate that each gene also functions to regulate hepatic fate mostly in a cell-autonomous fashion, revealing unprecedented roles of fetal hematopoietic progenitor markers in human liver progenitors. PMID:27509132

  16. Progenitors of type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Maeda, Keiichi; Terada, Yukikatsu

    2016-07-01

    Natures of progenitors of type Ia Supernovae (SNe Ia) have not yet been clarified. There has been long and intensive discussion on whether the so-called single degenerate (SD) scenario or the double degenerate (DD) scenario, or anything else, could explain a major population of SNe Ia, but the conclusion has not yet been reached. With rapidly increasing observational data and new theoretical ideas, the field of studying the SN Ia progenitors has been quickly developing, and various new insights have been obtained in recent years. This paper aims at providing a summary of the current situation regarding the SN Ia progenitors, both in theory and observations. It seems difficult to explain the emerging diversity seen in observations of SNe Ia by a single population, and we emphasize that it is important to clarify links between different progenitor scenarios and different sub-classes of SNe Ia.

  17. Enhanced adhesion of early endothelial progenitor cells to radiation-induced senescence-like vascular endothelial cells in vitro.

    PubMed

    Sermsathanasawadi, Nuttawut; Ishii, Hideto; Igarashi, Kaori; Miura, Masahiko; Yoshida, Masayuki; Inoue, Yoshinori; Iwai, Takehisa

    2009-09-01

    The effects of ionizing radiation (IR) on tumor neovascularization are still unclear. We previously reported that vascular endothelial cells (ECs) expressing the IR-induced senescence-like (IRSL) phenotype exhibit a significant decrease in angiogenic activity in vitro. In this study, we examined the effects of the IRSL phenotype on adhesion to early endothelial progenitor cells (early EPCs). Adhesion of human peripheral blood-derived early EPCs to human umbilical vein endothelial cells (HUVECs) expressing the IRSL phenotype was evaluated by an adhesion assay under static conditions. It was revealed that the IRSL HUVECs supported significantly more adhesion of early EPCs than normal HUVECs. Expressions of ICAM-1, VCAM-1 and E-selectin were up-regulated in IRSL HUVECs. Pre-treatment of IRSL HUVECs with adhesion-blocking monoclonal antibodies against E-selectin and VCAM-1 significantly reduced early EPC adhesion to IRSL HUVECs, suggesting a potential role for the E-selectin and VCAM-1 in the adhesion between IRSL ECs and early EPCs. Therefore, the IRSL phenotype expressed in ECs may enhance neovascularization via increased homing of early EPCs. Our findings are first to implicate the complex effects of this phenotype on tumor neovascularization following irradiation. PMID:19628926

  18. The reduction of serum soluble Flt-1 in patients with neovascular age-related macular degeneration

    PubMed Central

    Uehara, Hironori; Mamalis, Christina; McFadden, Molly; Taggart, Michael; Stagg, Brian; Passi, Samuel; Earle, Phillip; Chakravarthy, Usha; Hogg, Ruth E.; Ambati, Balamurali K.

    2014-01-01

    Purpose To evaluate serum soluble Flt-1 (sFlt-1) in age-related degeneration (AMD) patients. Design Case control study. Methods Fifty-six non-AMD participants, fifty-three early AMD patients and ninety-seven neovascular AMD patients from Belfast in Northern Ireland. Serum samples were collected from each patient. Serum sFlt-1 was measured by human sVEGFR1/sFlt-1 ELISA kit. The results were analyzed by Excel and SPSS. Results Serum sFlt-1 concentration of non-AMD, early AMD, and neovascular AMD were 90.8±2.9 pg/mL (±SEM), 88.2±2.6 pg/mL and 79.9±2.2 pg/mL. sFlt-1 from neovascular AMD patients was significantly decreased compared to non-AMD and early AMD patients (ANOVA, p<0.01). For each 10 point increase in sFlt-1, the odds for having neovascular AMD compared with non-AMD and neovascular AMD decreases by 27.8% OR=0.722 (95% CI: 0.588-0.888, p=0.002) and 27.0% OR=0.730 (95% CI: 0.594–0.898, p=0.003), respectively. In patients over 73 years of age, serum sFlt-1 <80 pg/mL was associated with a >6-fold higher risk of neovascular AMD. Conclusions Reduced serum sFlt-1 differentiates those patients with neovascular AMD from both early AMD and non-AMD participants. In those aged over 73, serum sFlt <80 pg/mL seems to indicate a particularly high risk of neovascular AMD. Our results indicate serum sFlt-1 could be a biomarker for development of neovascular AMD. PMID:25284761

  19. Angiogenesis in glaucoma filtration surgery and neovascular glaucoma: A review.

    PubMed

    Kim, Megan; Lee, Chelsea; Payne, Rachael; Yue, Beatrice Y J T; Chang, Jin-Hong; Ying, Hongyu

    2015-01-01

    Angiogenesis may pose a clinical challenge in glaucoma, for example, during the wound healing phase after glaucoma filtration surgery and in the severe secondary glaucoma called neovascular glaucoma (NVG). Upregulation of vascular endothelial growth factor (VEGF), a key mediator of angiogenesis, occurs in eyes that have undergone glaucoma filtration surgery, as well as those with NVG. This has led investigation of the ability of anti-vascular endothelial growth factor therapy to improve outcomes, and we examine the findings with respect to the safety and efficacy of anti-vascular endothelial growth factor agents, mainly bevacizumab and ranibizumab, in eyes that have undergone glaucoma filtration surgery or have NVG. Combining conventional therapies-such as antimetabolites after filtration surgery and panretinal photocoagulation in NVG-and anti-vascular endothelial growth factor drugs may produce a synergetic effect, although further studies are required to evaluate the long-term efficacy of combination treatments. PMID:25980779

  20. Radiation Therapy for Neovascular Age-related Macular Degeneration

    SciTech Connect

    Kishan, Amar U.; Modjtahedi, Bobeck S.; Morse, Lawrence S.; Lee, Percy

    2013-03-01

    In the enormity of the public health burden imposed by age-related macular degeneration (ARMD), much effort has been directed toward identifying effective and efficient treatments. Currently, anti-vascular endothelial growth factor (VEGF) injections have demonstrated considerably efficacy in treating neovascular ARMD, but patients require frequent treatment to fully benefit. Here, we review the rationale and evidence for radiation therapy of ARMD. The results of early photon external beam radiation therapy are included to provide a framework for the sequential discussion of evidence for the usage of stereotactic radiation therapy, proton therapy, and brachytherapy. The evidence suggests that these 3 modern modalities can provide a dose-dependent benefit in the treatment of ARMD. Most importantly, preliminary data suggest that all 3 can be used in conjunction with anti-VEGF therapeutics, thereby reducing the frequency of anti-VEGF injections required to maintain visual acuity.

  1. Synthesis and Biological Evaluation of Novel Homoisoflavonoids for Retinal Neovascularization

    PubMed Central

    Lee, Hyungjun; Sulaiman, Rania S.; An, Hongchan; Magaña, Carlos; Shadmand, Mehdi; Vayl, Alexandra; Rajashekhar, Gangaraju; Kim, Eun-Yeong; Suh, Young-Ger; Lee, Kiho

    2016-01-01

    Eye diseases characterized by excessive angiogenesis such as wet age-related macular degeneration, proliferative diabetic retinopathy, and retinopathy of prematurity are major causes of blindness. Cremastranone is an anti-angiogenic, naturally occurring homoisoflavanone with efficacy in retinal and choroidal neovascularization models and antiproliferative selectivity for endothelial cells over other cell types. We undertook a cell-based structure-activity relationship study to develop more potent cremastranone analogs, with improved antiproliferative selectivity for retinal endothelial cells. Phenylalanyl-incorporated homoisoflavonoids showed improved activity and remarkable selectivity for retinal microvascular endothelial cells. A lead compound inhibited angiogenesis in vitro without inducing apoptosis, and had efficacy in the oxygen-induced retinopathy model in vivo. PMID:26035340

  2. Choroidal Neovascularization Secondary to Myopia, Infection and Inflammation.

    PubMed

    Weber, Marissa L; Heier, Jeffrey S

    2016-01-01

    Choroidal neovascularization (CNV) is a significant cause of vision loss in all age groups. The most common cause of CNV is age-related macular degeneration (AMD). However, CNV can also occur as a secondary manifestation of various inherited and acquired conditions, including pathologic myopia, presumed ocular histoplasmosis syndrome, angioid streaks, and various hereditary, traumatic or inflammatory disorders. Fluorescein angiography and optical coherence tomography are useful tools in the diagnosis and evaluation of CNV. Treatment options are similar to those for CNV secondary to AMD, specifically anti-angiogenic therapy, but including laser photocoagulation, photodynamic therapy and surgery. Anti-angiogenic therapy has been associated with better visual outcomes than other treatment modalities and is now advocated as the first-line therapy for CNV secondary to myopia, infection and inflammation. PMID:26501802

  3. Diospyros kaki Extract Inhibits Alkali Burn-Induced Corneal Neovascularization.

    PubMed

    Yang, Sung Jae; Jo, Hyoung; Kim, Kyung-A; Ahn, Hong Ryul; Kang, Suk Woo; Jung, Sang Hoon

    2016-01-01

    The purpose of this study was to evaluate the effect of ethanol extract of Diospyros kaki (EEDK) leaves on corneal neovascularization (CoNV) in rats. One week after the alkali burns in the corneas, the CoNV area coverage in the CoNV-positive control group, 100 mg/kg EEDK group, and 200 mg/kg EEDK group was 43.3% ± 5.5%, 337.7% ± 2.5%, and 27.2% ± 4.3%, respectively. The areas of CoNV in the EEDK-treated groups were significantly different from those of the CoNV group. EEDK significantly attenuated the upregulation of vascular endothelial growth factor, fibroblast growth factor, interleukin-6, and matrix metalloproteinase-2 (MMP-2) protein levels. Orally administrated D. kaki inhibited CoNV development in rats. PMID:26348484

  4. Endothelial progenitor cells regenerate infracted myocardium with neovascularisation development.

    PubMed

    Abd El Aziz, M T; Abd El Nabi, E A; Abd El Hamid, M; Sabry, D; Atta, H M; Rahed, L A; Shamaa, A; Mahfouz, S; Taha, F M; Elrefaay, S; Gharib, D M; Elsetohy, Khaled A

    2015-03-01

    We achieved possibility of isolation, characterization human umbilical cord blood endothelial progenitor cells (EPCs), examination potency of EPCs to form new blood vessels and differentiation into cardiomyoctes in canines with acute myocardial infarction (AMI). EPCs were separated and cultured from umbilical cord blood. Their phenotypes were confirmed by uptake of double stains dioctadecyl tetramethylindocarbocyanine-labeled acetylated LDL and FITC-labeled Ulex europaeus agglutinin 1 (DILDL-UEA-1). EPCs of cord blood were counted. Human VEGFR-2 and eNOS from the cultured EPCs were assessed by qPCR. Human EPCs was transplanted intramyocardially in canines with AMI. ECG and cardiac enzymes (CK-MB and Troponin I) were measured to assess severity of cellular damage. Histopathology was done to assess neovascularisation. Immunostaining was done to detect EPCs transdifferentiation into cardiomyocytes in peri-infarct cardiac tissue. qPCR for human genes (hVEGFR-2, and eNOS) was done to assess homing and angiogenic function of transplanted EPCs. Cultured human cord blood exhibited an increased number of EPCs and significant high expression of hVEGFR-2 and eNOS genes in the culture cells. Histopathology showed increased neovascularization and immunostaining showed presence of EPCs newly differentiated into cardiomyocyte-like cells. Our findings suggested that hEPCs can mediate angiogenesis and differentiate into cardiomyoctes in canines with AMI. PMID:25750747

  5. Endothelial progenitor cells regenerate infracted myocardium with neovascularisation development☆

    PubMed Central

    Abd El Aziz, M.T.; Abd El Nabi, E.A.; Abd El Hamid, M.; Sabry, D.; Atta, H.M.; Rahed, L.A.; Shamaa, A.; Mahfouz, S.; Taha, F.M.; Elrefaay, S.; Gharib, D.M.; Elsetohy, Khaled A.

    2013-01-01

    We achieved possibility of isolation, characterization human umbilical cord blood endothelial progenitor cells (EPCs), examination potency of EPCs to form new blood vessels and differentiation into cardiomyoctes in canines with acute myocardial infarction (AMI). EPCs were separated and cultured from umbilical cord blood. Their phenotypes were confirmed by uptake of double stains dioctadecyl tetramethylindocarbocyanine-labeled acetylated LDL and FITC-labeled Ulex europaeus agglutinin 1 (DILDL-UEA-1). EPCs of cord blood were counted. Human VEGFR-2 and eNOS from the cultured EPCs were assessed by qPCR. Human EPCs was transplanted intramyocardially in canines with AMI. ECG and cardiac enzymes (CK-MB and Troponin I) were measured to assess severity of cellular damage. Histopathology was done to assess neovascularisation. Immunostaining was done to detect EPCs transdifferentiation into cardiomyocytes in peri-infarct cardiac tissue. qPCR for human genes (hVEGFR-2, and eNOS) was done to assess homing and angiogenic function of transplanted EPCs. Cultured human cord blood exhibited an increased number of EPCs and significant high expression of hVEGFR-2 and eNOS genes in the culture cells. Histopathology showed increased neovascularization and immunostaining showed presence of EPCs newly differentiated into cardiomyocyte-like cells. Our findings suggested that hEPCs can mediate angiogenesis and differentiate into cardiomyoctes in canines with AMI. PMID:25750747

  6. Effects of shear stress on endothelial progenitor cells.

    PubMed

    Obi, Syotaro; Yamamoto, Kimiko; Ando, Joji

    2014-10-01

    Endothelial progenitor cells (EPCs) are adult stem cells that play a central role in neovascularization. EPCs are mobilized from bone marrow into peripheral blood, attach to existing endothelial cells, and then transmigrate across the endothelium into tissues, where they proliferate, differentiate, and form new blood vessels. In the process, EPCs are exposed to shear stress, a biomechanical force generated by flowing blood and tissue fluid flow. When cultured EPCs are exposed to controlled levels of shear stress in a flow-loading device, their bioactivities in terms of proliferation, anti-apoptosis, migration, production of bioactive substances, anti-thrombosis, and tube formation increase markedly. Expression of endothelial marker genes and proteins by EPCs also increases in response to shear stress, and they differentiate into mature endothelial cells. Great advances have been made in elucidating the mechanisms by which mature endothelial cells sense and respond to shear stress, but not in EPCs. Further study of EPC responses to shear stress will be necessary to better understand the physiological and pathophysiological roles of EPCs and to apply EPCs to new therapies in the field of regenerative medicine. PMID:25992410

  7. Knockout of insulin and IGF-1 receptors on vascular endothelial cells protects against retinal neovascularization

    PubMed Central

    Kondo, Tatsuya; Vicent, David; Suzuma, Kiyoshi; Yanagisawa, Masashi; King, George L.; Holzenberger, Martin; Kahn, C. Ronald

    2003-01-01

    Both insulin and IGF-1 have been implicated in control of retinal endothelial cell growth, neovascularization, and diabetic retinopathy. To precisely define the role of insulin and IGF-1 signaling in endothelium in these processes, we have used the oxygen-induced retinopathy model to study mice with a vascular endothelial cell–specific knockout of the insulin receptor (VENIRKO) or IGF-1 receptor (VENIFARKO). Following relative hypoxia, VENIRKO mice show a 57% decrease in retinal neovascularization as compared with controls. This is associated with a blunted rise in VEGF, eNOS, and endothelin-1. By contrast, VENIFARKO mice show only a 34% reduction in neovascularization and a very modest reduction in mediator generation. These data indicate that both insulin and IGF-1 signaling in endothelium play a role in retinal neovascularization through the expression of vascular mediators, with the effect of insulin being most important in this process. PMID:12813019

  8. Profile of conbercept in the treatment of neovascular age-related macular degeneration

    PubMed Central

    Lu, Xinmin; Sun, Xiaodong

    2015-01-01

    In developed countries, age-related macular degeneration (AMD) is the leading cause of irreversible blindness in individuals over the age of 65 years. Vascular endothelial growth factor (VEGF) plays a vital role in the formation of neovascular AMD. VEGF regulates angiogenesis, enhances vascular permeability, and drives the formation of choroidal neovascularization. As a result of the introduction of anti-VEGF drugs, the incidence of blindness from neovascular AMD has greatly reduced. Anti-VEGF drugs are used as a first-line treatment for neovascular AMD. The most recent anti-VEGF drug is conbercept, also named KH902, which was approved for the treatment of neovascular AMD by the China Food and Drug Administration in December 2013. In this review, recent clinical information regarding the use of conbercept to treat neovascular AMD is summarized. Conbercept is a soluble receptor decoy that blocks all isoforms of VEGF-A, VEGF-B, VEGF-C, and PlGF, which has a high binding affinity to VEGF and a long half-life in vitreous. Preclinical studies have demonstrated its anti-angiogenesis activity in both ocular neovascular disease models and tumor models. Clinical trials of conbercept have shown its superior efficacy and safety. Patients respond well even with 3-month treatment intervals following loading doses once a month for 3 months. The potential therapeutic effect of conbercept on the treatment of polypoidal choroidal vasculopathy, a special type of neovascular AMD, is also promising. In summary, conbercept is a new treatment option for ophthalmologists and their patients and may help address the limitations of current anti-VEGF drugs. PMID:25960634

  9. Profile of conbercept in the treatment of neovascular age-related macular degeneration.

    PubMed

    Lu, Xinmin; Sun, Xiaodong

    2015-01-01

    In developed countries, age-related macular degeneration (AMD) is the leading cause of irreversible blindness in individuals over the age of 65 years. Vascular endothelial growth factor (VEGF) plays a vital role in the formation of neovascular AMD. VEGF regulates angiogenesis, enhances vascular permeability, and drives the formation of choroidal neovascularization. As a result of the introduction of anti-VEGF drugs, the incidence of blindness from neovascular AMD has greatly reduced. Anti-VEGF drugs are used as a first-line treatment for neovascular AMD. The most recent anti-VEGF drug is conbercept, also named KH902, which was approved for the treatment of neovascular AMD by the China Food and Drug Administration in December 2013. In this review, recent clinical information regarding the use of conbercept to treat neovascular AMD is summarized. Conbercept is a soluble receptor decoy that blocks all isoforms of VEGF-A, VEGF-B, VEGF-C, and PlGF, which has a high binding affinity to VEGF and a long half-life in vitreous. Preclinical studies have demonstrated its anti-angiogenesis activity in both ocular neovascular disease models and tumor models. Clinical trials of conbercept have shown its superior efficacy and safety. Patients respond well even with 3-month treatment intervals following loading doses once a month for 3 months. The potential therapeutic effect of conbercept on the treatment of polypoidal choroidal vasculopathy, a special type of neovascular AMD, is also promising. In summary, conbercept is a new treatment option for ophthalmologists and their patients and may help address the limitations of current anti-VEGF drugs. PMID:25960634

  10. Embryonic Heart Progenitors and Cardiogenesis

    PubMed Central

    Brade, Thomas; Pane, Luna S.; Moretti, Alessandra; Chien, Kenneth R.; Laugwitz, Karl-Ludwig

    2013-01-01

    The mammalian heart is a highly specialized organ, comprised of many different cell types arising from distinct embryonic progenitor populations during cardiogenesis. Three precursor populations have been identified to contribute to different myocytic and nonmyocytic cell lineages of the heart: cardiogenic mesoderm cells (CMC), the proepicardium (PE), and cardiac neural crest cells (CNCCs). This review will focus on molecular cues necessary for proper induction, expansion, and lineage-specific differentiation of these progenitor populations during cardiac development in vivo. Moreover, we will briefly discuss how the knowledge gained on embryonic heart progenitor biology can be used to develop novel therapeutic strategies for the management of congenital heart disease as well as for improvement of cardiac function in ischemic heart disease. PMID:24086063

  11. Slit2 signaling through Robo1 and Robo2 is required for retinal neovascularization

    PubMed Central

    Rama, Nicolas; Dubrac, Alexandre; Mathivet, Thomas; Chárthaigh, Róisín-Ana Ní; Genet, Gael; Cristofaro, Brunella; Pibouin-Fragner, Laurence; Ma, Le; Eichmann, Anne; Chédotal, Alain

    2016-01-01

    Ocular neovascular diseases are a leading cause of blindness. Vascular endothelial growth factor (VEGF) blockade improves vision, but not all individuals respond to anti-VEGF treatment, making additional means to prevent neovascularization necessary. Slit-family proteins (Slits) are ligands of Roundabout (Robo) receptors that repel developing axons in the nervous system. Robo1 expression is altered in ocular neovascular diseases, and previous in vitro studies have reported both pro- and anti-angiogenic effects of Slits. However, genetic evidence supporting a role for Slits in ocular neovascularization is lacking. Here we generated conditional knockout mice deficient in various Slit and Robo proteins and found that Slit2 potently and selectively promoted angiogenesis via Robo1 and Robo2 in mouse postnatal retina and in a model of ocular neovascular disease. Mechanistically, Slit2 acting through Robo1 and Robo2 promoted the migration of endothelial cells. These receptors are required for both Slit2- and VEGF-induced Rac1 activation and lamellipodia formation. Thus, Slit2 blockade could potentially be used therapeutically to inhibit angiogenesis in individuals with ocular neovascular disease. PMID:25894826

  12. Interleukin-12 inhibits pathological neovascularization in mouse model of oxygen-induced retinopathy

    PubMed Central

    Zhou, Yedi; Yoshida, Shigeo; Kubo, Yuki; Kobayashi, Yoshiyuki; Nakama, Takahito; Yamaguchi, Muneo; Ishikawa, Keijiro; Nakao, Shintaro; Ikeda, Yasuhiro; Ishibashi, Tatsuro; Sonoda, Koh-Hei

    2016-01-01

    Hypoxia-induced retinal neovascularization is a major pathological condition in many vision-threatening diseases. In the present study, we determined whether interleukin (IL)-12, a cytokine that regulates angiogenesis, plays a role in the neovascularization in a mouse model of oxygen-induced retinopathy (OIR). We found that the expressions of the mRNAs of both IL-12p35 and IL-12p40 were significantly reduced in the OIR retinas compared to that of the room air-raised control. The sizes of the avascular areas and neovascular tufts were larger in IL-12p40 knock-out (KO) mice than that in wild type (WT) mice. In addition, an intravitreal injection of recombinant IL-12 reduced both avascular areas and neovascular tufts. IL-12 injection enhanced the expressions of interferon-gamma (IFN-γ) and other downstream chemokines. In an in vitro system, IL-12 had no significant effect on tube formation of human retinal microvascular endothelial cells (HRECs). Moreover, a blockade of IFN-γ suppressed the inhibitory effect of IL-12 on pathological neovascularization. These results suggest that IL-12 plays important roles in inhibiting pathological retinal neovascularization. PMID:27312090

  13. Interleukin-12 inhibits pathological neovascularization in mouse model of oxygen-induced retinopathy.

    PubMed

    Zhou, Yedi; Yoshida, Shigeo; Kubo, Yuki; Kobayashi, Yoshiyuki; Nakama, Takahito; Yamaguchi, Muneo; Ishikawa, Keijiro; Nakao, Shintaro; Ikeda, Yasuhiro; Ishibashi, Tatsuro; Sonoda, Koh-Hei

    2016-01-01

    Hypoxia-induced retinal neovascularization is a major pathological condition in many vision-threatening diseases. In the present study, we determined whether interleukin (IL)-12, a cytokine that regulates angiogenesis, plays a role in the neovascularization in a mouse model of oxygen-induced retinopathy (OIR). We found that the expressions of the mRNAs of both IL-12p35 and IL-12p40 were significantly reduced in the OIR retinas compared to that of the room air-raised control. The sizes of the avascular areas and neovascular tufts were larger in IL-12p40 knock-out (KO) mice than that in wild type (WT) mice. In addition, an intravitreal injection of recombinant IL-12 reduced both avascular areas and neovascular tufts. IL-12 injection enhanced the expressions of interferon-gamma (IFN-γ) and other downstream chemokines. In an in vitro system, IL-12 had no significant effect on tube formation of human retinal microvascular endothelial cells (HRECs). Moreover, a blockade of IFN-γ suppressed the inhibitory effect of IL-12 on pathological neovascularization. These results suggest that IL-12 plays important roles in inhibiting pathological retinal neovascularization. PMID:27312090

  14. Femtosecond laser-assisted selective reduction of neovascularization in rat cornea.

    PubMed

    Sidhu, Mehra S; Choi, Min-Yeong; Woo, Suk-Yi; Lee, Hyun-Kyu; Lee, Heung-Soon; Kim, Kyu-Jin; Jeoung, Sae Chae; Choi, Jun-Sub; Joo, Choun-Ki; Park, Il-Hong

    2014-07-01

    Nonlinear multiphoton absorption induced by focusing near infrared (NIR) femtosecond (fs) laser pulses into a transparent cornea allows surgery on neovascular structures with minimal collateral damage. In this report, we introduce an fs laser-based microsurgery for selective treatment of rat corneal neovascularizations (in vivo). Contiguous tissue effects are achieved by scanning a focused laser pulse below the corneal surface with a fluence range of 2.2-8.6 J/cm(2). The minimal visible laser lesion (MVL) threshold determined over the corneal neovascular structures was found to be 4.3 J/cm(2). Histological and optical coherence tomography examinations of the anterior segment after laser irradiations show localized degeneration of neovascular structures without any unexpected change in adjacent tissues. Furthermore, an approximately 30 % reduction in corneal neovascularizations was observed after 5 days of fs laser exposure. The femtosecond laser is thus a promising tool for minimally invasive intrastromal surgery with the aid of a significantly smaller and more deterministic photodisruptive energy threshold for the interaction between the fs laser pulse and corneal neovascular structures. PMID:24570086

  15. The Progenitors of Thermonuclear Supernovae

    SciTech Connect

    Piersanti, L.; Straniero, O.; Tornambe, A.; Dominguez, I.

    2009-05-03

    In the framework of the rotating Double Degenerate Scenario for type Ia Supernovae progenitors, we show that the dichotomy between explosive events in early and late type galaxies can be easily explained. Assuming that more massive progenitors produce slow-decline (high-luminosity) light curve, it comes out that, at the current age of the Universe, in late type galaxies the continuous star formation provides very massive exploding objects (prompt component) corresponding to slow-decline (bright) SNe; on the other hand, in early type galaxies, where star formation ended many billions years ago, only low mass ''normal luminosity'' objects (delayed component) are present.

  16. NSAIDs inhibit neovascularization of choroid through HO-1-dependent pathway.

    PubMed

    Yoshinaga, Narimasa; Arimura, Noboru; Otsuka, Hiroki; Kawahara, Ko-Ichi; Hashiguchi, Teruto; Maruyama, Ikuro; Sakamoto, Taiji

    2011-09-01

    Intraocular neovascularization is the leading cause of severe visual loss and anti-vascular endothelial growth factor (VEGF) therapy is currently performed for choroidal neovascularization (CNV). Despite its potent anti-angiogenic effect, there are concerns about its long-term safety. Non-steroidal anti-inflammatory drugs (NSAIDs) are common therapeutic agents used for treating inflammatory diseases, and their anti-stress effects are attracting attention now. We studied the effects of topical NSAIDs on CNV, focusing on anti-stress proteins. Cultured retinal pigment epithelium (RPE) cells were treated with NSAIDs: bromfenac, indomethacin, or vehicle control. Transcription factor NF-E2-related factor 2 (Nrf2) and its downstream anti-oxidant protein heme oxygenase (HO)-1 were assessed using western blot and immunohistochemistry. As a result, NSAIDs induced translocation of Nrf2 into the nucleus and the robust expression of HO-1 in a dose- and time-dependent manner. Flow cytometric analysis revealed that bromfenac inhibited H(2)O(2)-induced apoptosis in cultured RPE cells. Next, we studied the effects of topical bromfenac on laser-induced CNV model in rat. The expressions of Nrf2 and HO-1, infiltrations of ED-1-positive macrophages at CNV lesions and size were analyzed. VEGF in the ocular fluid of these rats was also measured using enzyme-linked immunosorbent assay. Rats administered an inhibitor of HO-1 stannic mesoporphyrin (SnMP) were also studied. The results showed that topical bromfenac led to translocation of Nrf2 and induction of HO-1 in CNV lesions and that the number of infiltrating macrophages at the CNV lesion decreased. The sizes of CNV lesions were significantly smaller in bromfenac-treated rats than control CNV, and the effects were diminished by SnMP. VEGF increased in the ocular fluid after laser treatment and was inhibited by bromfenac and SnMP canceling these effects. NSAIDs inhibit CNV through the novel anti-stress protein HO-1-dependent pathway

  17. Progenitor Cells and Podocyte Regeneration

    PubMed Central

    Shankland, Stuart J.; Pippin, Jeffrey W.; Duffield, Jeremy S.

    2014-01-01

    The very limited ability of adult podocytes to proliferate in vivo is clinically significant because: podocytes form a vascular barrier which is functionally critical to the nephron; podocyte hypoplasia is a characteristic of disease; and inadequate regeneration of podocytes is a major cause of persistent podocyte hypoplasia. Excessive podocyte loss or inadequate replacement leads to glomerulosclerosis in many progressive kidney diseases. Thus, restoration of podocyte cell density is almost certainly reliant on regeneration by podocyte progenitors. However such putative progenitors have remained elusive until recently. In this review we describe the developmental processes leading to podocyte and parietal epithelial cell (PEC) formation during glomerulogenesis. We compare evidence that in normal human kidneys PECs expressing ‘progenitor’ markers CD133 and CD24 can differentiate into podocytes in vitro and in vivo with evidence from animal models suggesting a more limited role of PEC-capacity to serve as podocyte progenitors in adults. We will highlight tantalizing new evidence that specialized vascular wall cells of afferent arterioles including those which produce renin in healthy kidney, provide a novel local progenitor source of new PECs and podocytes in response to podocyte hypoplasia in the adult, and draw comparisons with glomerulogenesis. PMID:25217270

  18. Sustained delivery of a HIF-1 antagonist for ocular neovascularization.

    PubMed

    Iwase, Takeshi; Fu, Jie; Yoshida, Tsunehiko; Muramatsu, Daisuke; Miki, Akiko; Hashida, Noriyasu; Lu, Lili; Oveson, Brian; Lima e Silva, Raquel; Seidel, Christopher; Yang, Ming; Connelly, Sheila; Shen, Jikui; Han, Bing; Wu, Mingsheng; Semenza, Gregg L; Hanes, Justin; Campochiaro, Peter A

    2013-12-28

    Doxorubicin (DXR) and daunorubicin (DNR) inhibit hypoxia-inducible factor-1 (HIF-1) transcriptional activity by blocking its binding to DNA. Intraocular injections of DXR or DNR suppressed choroidal and retinal neovascularization (NV), but also perturbed retinal function as demonstrated by electroretinograms (ERGs). DXR was conjugated to novel copolymers of branched polyethylene glycol and poly(sebacic acid) (DXR-PSA-PEG3) and formulated into nanoparticles that when placed in aqueous buffer, slowly released small DXR-conjugates. Intraocular injection of DXR-PSA-PEG3 nanoparticles (1 or 10 μg DXR content) reduced HIF-1-responsive gene products, strongly suppressed choroidal and retinal NV, and did not cause retinal toxicity. In transgenic mice that express VEGF in photoreceptors, intraocular injection of DXR-PSA-PEG3 nanoparticles (10 μg DXR content) suppressed NV for at least 35 days. Intraocular injection of DXR-PSA-PEG3 nanoparticles (2.7 mg DXR content) in rabbits resulted in sustained DXR-conjugate release with detectable levels in aqueous humor and vitreous for at least 105 days. This study demonstrates a novel HIF-1-inhibitor-polymer conjugate formulated into controlled-release particles that maximizes efficacy and duration of activity, minimizes toxicity, and provides a promising new chemical entity for treatment of ocular NV. PMID:24126220

  19. An Angiogenic Role for Adrenomedullin in Choroidal Neovascularization

    PubMed Central

    Sakimoto, Susumu; Kidoya, Hiroyasu; Kamei, Motohiro; Naito, Hisamichi; Yamakawa, Daishi; Sakaguchi, Hirokazu; Wakabayashi, Taku; Nishida, Kohji; Takakura, Nobuyuki

    2013-01-01

    Purpose Adrenomedullin (ADM) has been shown to take part in physiological and pathological angiogenesis. The purpose of this study was to investigate whether ADM signaling is involved in choroidal neovascularization (CNV) using a mouse model. Methods and Results CNV was induced by laser photocoagulation in 8-week-old C57BL/6 mice. ADM mRNA expression significantly increased following treatment, peaking 4 days thereafter. The expression of ADM receptor (ADM-R) components (CRLR, RAMP2 and RAMP 3) was higher in CD31+CD45− endothelial cells (ECs) than CD31−CD45− non-ECs. Inflammatory stimulation upregulated the expression of ADM not only in cell lines but also in cells in primary cultures of the choroid/retinal pigment epithelium complex. Supernatants from TNFα-treated macrophage cell lines potentiated the proliferation of ECs and this was partially suppressed by an ADM antagonist, ADM (22–52). Intravitreous injection of ADM (22–52) or ADM neutralizing monoclonal antibody (mAb) after laser treatment significantly reduced the size of CNV compared with vehicle-treated controls (p<0.01). Conclusions ADM signaling is involved in laser-induced CNV formation, because both an ADM antagonist and ADM mAb significantly inhibited it. Suppression of ADM signaling might be a valuable alternative treatment for CNV associated with age-related macular degeneration. PMID:23520487

  20. Overload and neovascularization of shoulder tendons in volleyball players

    PubMed Central

    2012-01-01

    Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05). Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles. PMID:22853746

  1. Sustained Delivery of a HIF-1 Antagonist for Ocular Neovascularization

    PubMed Central

    Iwase, Takeshi; Fu, Jie; Yoshida, Tsunehiko; Muramatsu, Daisuke; Miki, Akiko; Hashida, Noriyasu; Lu, Lili; Oveson, Brian; Silva, Raquel Lima e; Seidel, Christopher; Yang, Ming; Connelly, Sheila; Shen, Jikui; Han, Bing; Wu, Mingsheng; Semenza, Gregg L.; Hanes, Justin; Campochiaro, Peter A.

    2013-01-01

    Doxorubicin (DXR) and daunorubicin (DNR) inhibit hypoxia-inducible factor-1 (HIF-1) transcriptional activity by blocking its binding to DNA. Intraocular injections of DXR or DNR suppressed choroidal and retinal neovascularization (NV), but also perturbed retinal function as demonstrated by electroretinograms (ERGs). DXR was conjugated to novel copolymers of branched polyethylene glycol and poly(sebacic acid) (DXR-PSA-PEG3) and formulated into nanoparticles that when placed in aqueous buffer, slowly released small DXR-conjugates. Intraocular injection of DXR-PSA-PEG3 nanoparticles (1 or 10 μg DXR content) reduced HIF-1-responsive gene products, strongly suppressed choroidal and retinal NV, and did not cause retinal toxicity. In transgenic mice that express VEGF in photoreceptors, intraocular injection of DXR-PSA-PEG3 nanoparticles (10 μg DXR content) suppressed NV for at least 35 days. Intraocular injection of DXR-PSA-PEG3 nanoparticles (2.7 mg DXR content) in rabbits resulted in sustained DXR-conjugate release with detectable levels in aqueous humor and vitreous for at least 105 days. This study demonstrates a novel HIF-1-inhibitor-polymer conjugate formulated into controlled-release particles that maximizes efficacy and duration of activity, minimizes toxicity, and provides a promising new chemical entity for treatment of ocular NV. PMID:24126220

  2. Implementation studies of ranibizumab for neovascular age-related macular degeneration.

    PubMed

    Bloch, Sara Brandi

    2013-11-01

    The pathogenesis of AMD is associated with age changes plus pathological changes involving oxidative stress and an altered inflammatory response leading to injury of retinal pigment epithelial cells and the adjacent choroidea and photoreceptor cells. AMD is divided into early, intermediate and advanced AMD. The advanced form of AMD is further divided into non-neovascular AMD and neovascular AMD. The diagnosis of neovascular AMD is based on FA and clinical characteristics of the eyes. The CNV lesions are by their growth pattern divided into type 1 CNV lesions, which grow primarily beneath the RPE, and type 2 CNV lesions, which have penetrated the RPE and evolve within the subretinal space. The natural course of neovascular AMD leads to visual disability in a majority of cases within the first years after onset, primarily caused by the development of subfoveal fibrous tissue and atrophy of the RPE. The prognosis of visual acuity in neovascular AMD has been markedly improved by the introduction of an intravitreal administered VEGF inhibitor (ranibizumab) given on a monthly basis. Treatment with ranibizumab for neovascular AMD was introduced in Denmark in 2006 under a fully reimbursed national healthcare plan. Treatment with ranibizumab is given in a variable dosing regimen that varies from the monthly dosing regimen administered in the studies that led to the approval of ranibizumab for neovascular AMD in Europe. The main objectives of this PhD thesis were to evaluate and potentially improve treatment with ranibizumab in a variable OCT guided regimen for neovascular AMD. Another intension of this PhD thesis was to prepare the conditions for future research to further improve the visual prognosis in neovascular AMD treated with anti-VEGF agents. The first study revealed that vision was improved in eyes with active neovascular AMD treated for 1 year in a variable ranibizumab treatment regimen as compared to PDT and the natural course of the disease. We assumed by

  3. Targeting Platelet-Derived Growth Factor Receptor β(+) Scaffold Formation Inhibits Choroidal Neovascularization.

    PubMed

    Strittmatter, Karin; Pomeroy, Hayley; Marneros, Alexander G

    2016-07-01

    Neovascular age-related macular degeneration is among the most common causes of irreversible blindness and manifests with choroidal neovascularization (CNV). Anti-vascular endothelial growth factor-A therapies are only partially effective and their chronic administration may impair functions of the choriocapillaris and retina. Thus, novel therapeutic targets are needed urgently. We have observed in a laser-induced model of CNV that a platelet-derived growth factor receptor β positive (PDGFRβ(+)) scaffold is formed before infiltration of neovessels into this scaffold to form CNV lesions, and that this scaffold limits the extent of neovascularization. Based on these observations we hypothesized that ablation of proliferating PDGFRβ(+) cells to prevent the formation of this scaffold might inhibit CNV growth and present a novel therapeutic approach for neovascular age-related macular degeneration. To test this hypothesis we targeted proliferating PDGFRβ(+) cells through independent distinct approaches after laser injury: i) by using an inducible genetic model to inhibit specifically proliferating PDGFRβ(+) cells, ii) by treating mice with a neutralizing anti-PDGFRβ antibody, iii) by administering an anti-PDGF-AB/BB aptamer, and iv) by using small chemical inhibitor approaches. The results show that therapeutic targeting of proliferating PDGFRβ(+) cells potently inhibits the formation of the pericyte-like scaffold, with concomitant attenuation of CNV. Moreover, we show that early inhibition of PDGFRβ(+) cell proliferation before neovessel formation is sufficient to inhibit scaffold formation and neovascularization. PMID:27338108

  4. Resistance to anti-VEGF therapy in neovascular age-related macular degeneration: a comprehensive review

    PubMed Central

    Yang, Shiqi; Zhao, Jingke; Sun, Xiaodong

    2016-01-01

    As a progressive chronic disease, age-related macular degeneration (AMD) is the leading cause of irreversible vision impairment worldwide. Experimental and clinical evidence has demonstrated that vascular endothelial growth factor (VEGF) plays a vital role in the formation of choroidal neovascularization. Intravitreal injections of anti-VEGF agents have been recommended as a first-line treatment for neovascular AMD. However, persistent fluid or recurrent exudation still occurs despite standardized anti-VEGF therapy. Patients suffering from refractory or recurrent neovascular AMD may develop mechanisms of resistance to anti-VEGF therapy, which results in a diminished therapeutic effect. Until now, there has been no consensus on the definitions of refractory neovascular AMD and recurrent neovascular AMD. This article aims at clarifying these concepts to evaluate the efficacy of switching drugs, which contributes to making clinical decision more scientifically. Furthermore, insight into the causes of resistance to anti-VEGF therapy would be helpful for developing possible therapeutic approaches, such as combination therapy and multi-target treatment that can overcome this resistance. PMID:27330279

  5. Endothelial microRNA-150 is an intrinsic suppressor of pathologic ocular neovascularization

    PubMed Central

    Liu, Chi-Hsiu; Sun, Ye; Li, Jie; Gong, Yan; Tian, Katherine T.; Evans, Lucy P.; Morss, Peyton C.; Fredrick, Thomas W.; Saba, Nicholas J.; Chen, Jing

    2015-01-01

    Pathologic ocular neovascularization commonly causes blindness. It is critical to identify the factors altered in pathologically proliferating versus normally quiescent vessels to develop effective targeted therapeutics. MicroRNAs regulate both physiological and pathological angiogenesis through modulating expression of gene targets at the posttranscriptional level. However, it is not completely understood if specific microRNAs are altered in pathologic ocular blood vessels, influencing vascular eye diseases. Here we investigated the potential role of a specific microRNA, miR-150, in regulating ocular neovascularization. We found that miR-150 was highly expressed in normal quiescent retinal blood vessels and significantly suppressed in pathologic neovessels in a mouse model of oxygen-induced proliferative retinopathy. MiR-150 substantially decreased endothelial cell function including cell proliferation, migration, and tubular formation and specifically suppressed the expression of multiple angiogenic regulators, CXCR4, DLL4, and FZD4, in endothelial cells. Intravitreal injection of miR-150 mimic significantly decreased pathologic retinal neovascularization in vivo in both wild-type and miR-150 knockout mice. Loss of miR-150 significantly promoted angiogenesis in aortic rings and choroidal explants ex vivo and laser-induced choroidal neovascularization in vivo. In conclusion, miR-150 is specifically enriched in quiescent normal vessels and functions as an endothelium-specific endogenous inhibitor of pathologic ocular neovascularization. PMID:26374840

  6. Intrachoroidal Neovascularization in Transgenic Mice Overexpressing Vascular Endothelial Growth Factor in the Retinal Pigment Epithelium

    PubMed Central

    Schwesinger, Catherine; Yee, Charles; Rohan, Richard M.; Joussen, Antonia M.; Fernandez, Antonio; Meyer, Tobias N.; Poulaki, Vassiliki; Ma, Joseph J. K.; Redmond, T. Michael; Liu, Suyan; Adamis, Anthony P.; D’Amato, Robert J.

    2001-01-01

    Choroidal neovascularization in age-related macular degeneration is a frequent and poorly treatable cause of vision loss in elderly Caucasians. This choroidal neovascularization has been associated with the expression of vascular endothelial growth factor (VEGF). In current animal models choroidal neovascularization is induced by subretinal injection of growth factors or vectors encoding growth factors such as VEGF, or by disruption of the Bruch’s membrane/retinal pigment epithelium complex with laser treatment. We wished to establish a transgenic murine model of age-related macular degeneration, in which the overexpression of VEGF by the retinal pigment epithelium induces choroidal neovascularization. A construct consisting of a tissue-specific murine retinal pigment epithelium promoter (RPE65 promoter) coupled to murine VEGF164 cDNA with a rabbit β-globin-3′ UTR was introduced into the genome of albino mice. Transgene mRNA was expressed in the retinal pigment epithelium at all ages peaking at 4 months. The expression of VEGF protein was increased in both the retinal pigment epithelium and choroid. An increase of intravascular adherent leukocytes and vessel leakage was observed. Histopathology revealed intrachoroidal neovascularization that did not penetrate through an intact Bruch’s membrane. These results support the hypothesis that additional insults to the integrity of Bruch’s membrane are required to induce growth of choroidal vessels into the subretinal space as seen in age-related macular degeneration. This model may be useful to screen for inhibitors of choroidal vessel growth. PMID:11238064

  7. Endothelial microRNA-150 is an intrinsic suppressor of pathologic ocular neovascularization.

    PubMed

    Liu, Chi-Hsiu; Sun, Ye; Li, Jie; Gong, Yan; Tian, Katherine T; Evans, Lucy P; Morss, Peyton C; Fredrick, Thomas W; Saba, Nicholas J; Chen, Jing

    2015-09-29

    Pathologic ocular neovascularization commonly causes blindness. It is critical to identify the factors altered in pathologically proliferating versus normally quiescent vessels to develop effective targeted therapeutics. MicroRNAs regulate both physiological and pathological angiogenesis through modulating expression of gene targets at the posttranscriptional level. However, it is not completely understood if specific microRNAs are altered in pathologic ocular blood vessels, influencing vascular eye diseases. Here we investigated the potential role of a specific microRNA, miR-150, in regulating ocular neovascularization. We found that miR-150 was highly expressed in normal quiescent retinal blood vessels and significantly suppressed in pathologic neovessels in a mouse model of oxygen-induced proliferative retinopathy. MiR-150 substantially decreased endothelial cell function including cell proliferation, migration, and tubular formation and specifically suppressed the expression of multiple angiogenic regulators, CXCR4, DLL4, and FZD4, in endothelial cells. Intravitreal injection of miR-150 mimic significantly decreased pathologic retinal neovascularization in vivo in both wild-type and miR-150 knockout mice. Loss of miR-150 significantly promoted angiogenesis in aortic rings and choroidal explants ex vivo and laser-induced choroidal neovascularization in vivo. In conclusion, miR-150 is specifically enriched in quiescent normal vessels and functions as an endothelium-specific endogenous inhibitor of pathologic ocular neovascularization. PMID:26374840

  8. Strategies for improving early detection and diagnosis of neovascular age-related macular degeneration

    PubMed Central

    Keane, Pearse A; de Salvo, Gabriella; Sim, Dawn A; Goverdhan, Srini; Agrawal, Rupesh; Tufail, Adnan

    2015-01-01

    Treatment of the neovascular form of age-related macular degeneration (AMD) has been revolutionized by the introduction of such agents as ranibizumab, bevacizumab, and aflibercept. As a result, the incidence of legal blindness occurring secondary to AMD has fallen dramatically in recent years in many countries. While these agents have undoubtedly been successful in reducing visual impairment and blindness, patients with neovascular AMD typically lose some vision over time, and often lose the ability to read, drive, or perform other important activities of daily living. Efforts are therefore under way to develop strategies that allow for earlier detection and treatment of this disease. In this review, we begin by providing an overview of the rationale for, and the benefits of, early detection and treatment of neovascular AMD. To achieve this, we begin by providing an overview of the pathophysiology and natural history of choroidal neovascularization, before reviewing the evidence from both clinical trials and “real-world” outcome studies. We continue by highlighting an area that is often overlooked: the importance of patient education and awareness for early AMD detection. We conclude the review by reviewing an array of both established and emerging technologies for early detection of choroidal neovascularization, ranging from Amsler chart testing, to hyperacuity testing, to advanced imaging techniques, such as optical coherence tomography. PMID:25733802

  9. Strategies for improving early detection and diagnosis of neovascular age-related macular degeneration.

    PubMed

    Keane, Pearse A; de Salvo, Gabriella; Sim, Dawn A; Goverdhan, Srini; Agrawal, Rupesh; Tufail, Adnan

    2015-01-01

    Treatment of the neovascular form of age-related macular degeneration (AMD) has been revolutionized by the introduction of such agents as ranibizumab, bevacizumab, and aflibercept. As a result, the incidence of legal blindness occurring secondary to AMD has fallen dramatically in recent years in many countries. While these agents have undoubtedly been successful in reducing visual impairment and blindness, patients with neovascular AMD typically lose some vision over time, and often lose the ability to read, drive, or perform other important activities of daily living. Efforts are therefore under way to develop strategies that allow for earlier detection and treatment of this disease. In this review, we begin by providing an overview of the rationale for, and the benefits of, early detection and treatment of neovascular AMD. To achieve this, we begin by providing an overview of the pathophysiology and natural history of choroidal neovascularization, before reviewing the evidence from both clinical trials and "real-world" outcome studies. We continue by highlighting an area that is often overlooked: the importance of patient education and awareness for early AMD detection. We conclude the review by reviewing an array of both established and emerging technologies for early detection of choroidal neovascularization, ranging from Amsler chart testing, to hyperacuity testing, to advanced imaging techniques, such as optical coherence tomography. PMID:25733802

  10. The association between neovascular age-related macular degeneration and regulatory T cells in peripheral blood

    PubMed Central

    Madelung, Christopher Fugl; Falk, Mads Krüger; Sørensen, Torben Lykke

    2015-01-01

    Purpose To investigate regulatory T cells (Tregs) and subsets of the Treg population in patients with neovascular age-related macular degeneration (AMD). Patients and methods Twenty-one neovascular AMD cases and 12 age-matched controls without retinal pathology were selected. Patients were recruited from our outpatient retinal clinic. Control individuals were typically spouses. The diagnosis of neovascular AMD was confirmed using fluorescein and indocyaningreen angiography. Fresh venous blood was analyzed by flow cytometry using fluorochrome-conjugated antibodies to the Treg surface antigens CD4, CD25, CD127, CD45RA, and CD31. Main outcome measures were the percentage of CD25highCD127low Tregs, the percentage of CD45RA+ naïve Tregs, and the percentage of CD31+ recent thymic emigrant Tregs. Results Comparing patients with neovascular AMD to controls, no significant differences were found in the percentages of CD4+ lymphocytes, CD25highCD127low Tregs, CD45RA+ naïve Tregs, or CD31+ recent thymic emigrant Tregs. Conclusion Our data does not indicate an altered state of systemic Treg cells in neovascular AMD. PMID:26170606

  11. Modifying Choroidal Neovascularization Development with a Nutritional Supplement in Mice

    PubMed Central

    Ivanescu, Alina Adriana; Fernández-Robredo, Patricia; Heras-Mulero, Henar; Sádaba-Echarri, Luis Manuel; García-García, Laura; Fernández-García, Vanessa; Moreno-Orduna, Maite; Redondo-Exposito, Aitor; Recalde, Sergio; García-Layana, Alfredo

    2015-01-01

    We examined the effect of nutritional supplements (modified Age Related Eye Disease Study (AREDS)-II formulation containing vitamins, minerals, lutein, resveratrol, and omega-3 fatty acids) on choroidal neovascularization (CNV). Supplements were administered alone and combined with intravitreal anti-VEGF in an early-CNV (diode laser-induced) murine model. Sixty mice were evenly divided into group V (oral vehicle, intravitreal saline), group S (oral supplement, intravitreal saline), group V + aVEGF (oral vehicle, intravitreal anti-VEGF), and group S + aVEGF (oral supplement, intravitreal anti-VEGF). Vehicle and nutritional supplements were administered daily for 38 days beginning 10 days before laser. Intravitreal injections were administered 48 h after laser. Fluorescein angiography (FA) and flat-mount CD31 staining evaluated leakage and CNV lesion area. Expression of VEGF, MMP-2 and MMP-9 activity, and NLRP3 were evaluated with RT-PCR, zymography, and western-blot. Leakage, CNV size, VEGF gene and protein expression were lower in groups V + aVEGF, S + aVEGF, and S than in V (all p < 0.05). Additionally, MMP-9 gene expression differed between groups S + aVEGF and V (p < 0.05) and MMP-9 activity was lower in S + aVEGF than in V and S (both p < 0.01). Levels of MMP-2 and NLRP3 were not significantly different between groups. Nutritional supplements either alone or combined with anti-VEGF may mitigate CNV development and inhibit retinal disease involving VEGF overexpression and CNV. PMID:26153682

  12. Improved assessment of laser-induced choroidal neovascularization

    PubMed Central

    Toma, Hassanain S.; Barnett, Joshua M.; Penn, John S.; Kim, Stephen J.

    2011-01-01

    The primary objective of this study was to develop and evaluate new methods of analyzing laser-induced choroidal neovascularization (CNV), in order to make recommendations for improving the reporting of experimental CNV in the literature. Six laser burns of sufficient power to rupture Bruch's membrane were concentrically placed in each eye of 18 adult Norway rats. Eyes received intravitreal injections of either triamcinolone acetonide, ketorolac, or balanced salt solution (BSS). Fluorescein angiography (FA) was performed 2 and 3 weeks after injection, followed by choroidal flat mount preparation. Vascular leakage on FAs and vascular budding on choroidal mounts were quantified by measuring either the cross-sectional area of each CNV lesion contained within the best-fitting polygon using Adobe Photoshop (Lasso Technique or Quick Selection Technique), or the area of bright pixels within a lesion using Image-Pro Plus. On choroidal mounts, the Lasso Technique and Image-Pro Plus detected a significant difference in lesion size between either ketorolac or triamcinolone when compared to BSS, while the Quick Selection Technique did not (Lasso Technique, 0.78 and 0.64; Image-Pro Plus, 0.77 and 0.65). On FA, the Lasso Technique and Quick Selection Technique detected a significant difference in lesion size between either ketorolac or triamcinolone when compared to BSS, while Image-Pro Plus did not (Lasso Tool, 0.81 and 0.54; Quick Selection Tool, 0.76 and 0.57). Choroidal mounts and FA are both valuable for imaging experimental CNV. Adobe Photoshop and Image-Pro Plus are both able to detect subtle differences in CNV lesion size, when images are not manipulated. The combination of choroidal mounts and FA provides a more comprehensive assessment of CNV anatomy and physiology. PMID:20553963

  13. Modifying Choroidal Neovascularization Development with a Nutritional Supplement in Mice.

    PubMed

    Ivanescu, Alina Adriana; Fernández-Robredo, Patricia; Heras-Mulero, Henar; Sádaba-Echarri, Luis Manuel; García-García, Laura; Fernández-García, Vanessa; Moreno-Orduna, Maite; Redondo-Exposito, Aitor; Recalde, Sergio; García-Layana, Alfredo

    2015-07-01

    We examined the effect of nutritional supplements (modified Age Related Eye Disease Study (AREDS)-II formulation containing vitamins, minerals, lutein, resveratrol, and omega-3 fatty acids) on choroidal neovascularization (CNV). Supplements were administered alone and combined with intravitreal anti-VEGF in an early-CNV (diode laser-induced) murine model. Sixty mice were evenly divided into group V (oral vehicle, intravitreal saline), group S (oral supplement, intravitreal saline), group V + aVEGF (oral vehicle, intravitreal anti-VEGF), and group S + aVEGF (oral supplement, intravitreal anti-VEGF). Vehicle and nutritional supplements were administered daily for 38 days beginning 10 days before laser. Intravitreal injections were administered 48 h after laser. Fluorescein angiography (FA) and flat-mount CD31 staining evaluated leakage and CNV lesion area. Expression of VEGF, MMP-2 and MMP-9 activity, and NLRP3 were evaluated with RT-PCR, zymography, and western-blot. Leakage, CNV size, VEGF gene and protein expression were lower in groups V + aVEGF, S + aVEGF, and S than in V (all p < 0.05). Additionally, MMP-9 gene expression differed between groups S + aVEGF and V (p < 0.05) and MMP-9 activity was lower in S + aVEGF than in V and S (both p < 0.01). Levels of MMP-2 and NLRP3 were not significantly different between groups. Nutritional supplements either alone or combined with anti-VEGF may mitigate CNV development and inhibit retinal disease involving VEGF overexpression and CNV. PMID:26153682

  14. IKK2 Inhibition Attenuates Laser-Induced Choroidal Neovascularization

    PubMed Central

    Lu, Huayi; Lu, Qingxian; Gaddipati, Subhash; Kasetti, Ramesh Babu; Wang, Wei; Pasparakis, Manolis; Kaplan, Henry J.; Li, Qiutang

    2014-01-01

    Choroidal neovascularization (CNV) is aberrant angiogenesis associated with exudative age-related macular degeneration (AMD), a leading cause of blindness in the elderly. Inflammation has been suggested as a risk factor for AMD. The IKK2/NF-κB pathway plays a key role in the inflammatory response through regulation of the transcription of cytokines, chemokines, growth factors and angiogenic factors. We investigated the functional role of IKK2 in development of the laser-induced CNV using either Ikk2 conditional knockout mice or an IKK2 inhibitor. The retinal neuronal tissue and RPE deletion of IKK2 was generated by breeding Ikk2−/flox mice with Nestin-Cre mice. Deletion of Ikk2 in the retina caused no obvious defect in retinal development or function, but resulted in a significant reduction in laser-induced CNV. In addition, intravitreal or retrobulbar injection of an IKK2 specific chemical inhibitor, TPCA-1, also showed similar inhibition of CNV. Furthermore, in vitro inhibition of IKK2 in ARPE-19 cells significantly reduced heat shock-induced expression of NFKBIA, IL1B, CCL2, VEGFA, PDGFA, HIF1A, and MMP-2, suggesting that IKK2 may regulate multiple molecular pathways involved in laser-induced CNV. The in vivo laser-induced expression of VEGFA, and HIF1A in RPE and choroidal tissue was also blocked by TPCA-1 treatment. Thus, IKK2/NF-κB signaling appears responsible for production of pro-inflammatory and pro-angiogenic factors in laser-induced CNV, suggesting that this intracellular pathway may serve as an important therapeutic target for aberrant angiogenesis in exudative AMD. PMID:24489934

  15. PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS

    SciTech Connect

    Moriya, Takashi J.

    2012-05-01

    Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

  16. Sulodexide inhibits retinal neovascularization in a mouse model of oxygen-induced retinopathy

    PubMed Central

    Jo, Hyoung; Jung, Sang Hoon; Kang, Jun; Yim, Hye Bin; Kang, Kui Dong

    2014-01-01

    Sulodexide is a mixed glycosaminoglycan composed of heparin and dermatan sulfate. In this study, the anti-angiogenic effect of sulodexide was investigated using an oxygen-induced retinopathy (OIR) mouse model. The retinas of sham-injected OIR mice (P17) had a distinctive central area of nonperfusion, and this area was significantly decreased in sulodexide-injected mice. The number of neovascular tufts measured by SWIFT_NV and mean neovascular lumen number were significantly decreased in sulodexide-injected mice. Hyperbaric oxygen exposure resulted in increased levels of VEGF, MMP-2 and MMP-9, and when mice were treated with sulodexide, a dose-dependent reduction in VEGF, MMP-2 and MMP-9 levels was observed. Our results clearly demonstrate the anti-angiogenic effect of sulodexide and highlight sulodexide as a candidate supplementary substance to be used for the treatment of ocular pathologies that involve neovascularization. [BMB Reports 2014; 47(11): 637-642] PMID:24602608

  17. Lack of association between VAP-1/SSAO activity and corneal neovascularization in a rabbit model.

    PubMed

    Énzsöly, Anna; Markó, Katalin; Tábi, Tamás; Szökő, Éva; Zelkó, Romána; Tóth, Miklós; Petrash, J Mark; Mátyus, Péter; Németh, János

    2013-06-01

    The aim of this study is to determine the efficacy of a potent and specific vascular adhesive protein-1/semicarbazide-sensitive amine oxidase (VAP-1/SSAO) inhibitor, LJP 1207, as a potential antiangiogenic and anti-inflammatory agent in the therapy of corneal neovascularization. Corneal neovascularization was induced with intrastromal suturing in rabbits (n = 20). Topical treatment with VAP-1/SSAO inhibitor LJP 1207 (n = 5, 4 times a day), bevacizumab (n = 5, daily), their combination (n = 5) and vehicle only (n = 5, 4 times a day) were applied postoperatively for 2 weeks. The development and extent of corneal neovascularization were evaluated by digital image analysis. At the end of the observation period, the level of corneal and serum VAP-1/SSAO activity was measured fluorometrically and radiochemically. The corneal VAP-1/SSAO activity was significantly elevated in the suture-challenged vehicle-treated group (3,075 ± 1,009 pmol/mg/h) as compared to unoperated controls (464.2 ± 135 pmol/mg/h, p < 0.001). Treatment with LJP 1207 resulted in slower early phase neovascularization compared to vehicle-treated animals (not significant). At days 7-14, there was no significant difference in the extent of corneal neovascularization between inhibitor- and vehicle-treated corneas, even though inhibitor treatment caused a normalization of corneal VAP-1/SSAO activity (885 ± 452 pmol/mg/h). Our results demonstrate that the significant elevation of VAP-1/SSAO activity due to corneal injury can be prevented with VAP-1/SSAO inhibitor LJP 1207 treatment. However, normalization of VAP-1/SSAO activity in this model does not prevent the development of corneal neovascularization. PMID:23397320

  18. Lack of association between VAP-1/SSAO activity and corneal neovascularization in a rabbit model

    PubMed Central

    Markó, Katalin; Tábi, Tamás; Szökő, Éva; Zelkó, Romána; Tóth, Miklós; Petrash, J. Mark; Mátyus, Péter; Németh, János

    2014-01-01

    The aim of this study is to determine the efficacy of a potent and specific vascular adhesive protein-1/ semicarbazide-sensitive amine oxidase (VAP-1/SSAO) inhibitor, LJP 1207, as a potential antiangiogenic and anti-inflammatory agent in the therapy of corneal neovascularization. Corneal neovascularization was induced with intrastromal suturing in rabbits (n = 20). Topical treatment with VAP-1/SSAO inhibitor LJP 1207 (n = 5, 4 times a day), bevacizumab (n = 5, daily), their combination (n = 5) and vehicle only (n = 5, 4 times a day) were applied postoperatively for 2 weeks. The development and extent of corneal neovascularization were evaluated by digital image analysis. At the end of the observation period, the level of corneal and serum VAP-1/SSAO activity was measured fluorometrically and radiochemically. The corneal VAP-1/SSAO activity was significantly elevated in the suture-challenged vehicle-treated group (3,075 ± 1,009 pmol/mg/h) as compared to unoperated controls (464.2 ± 135 pmol/mg/h, p <0.001). Treatment with LJP 1207 resulted in slower early phase neovascularization compared to vehicle-treated animals (not significant). At days 7–14, there was no significant difference in the extent of corneal neovascularization between inhibitor- and vehicle-treated corneas, even though inhibitor treatment caused a normalization of corneal VAP-1/SSAO activity (885 ± 452 pmol/mg/h). Our results demonstrate that the significant elevation of VAP-1/SSAO activity due to corneal injury can be prevented with VAP-1/SSAO inhibitor LJP 1207 treatment. However, normalization of VAP-1/ SSAO activity in this model does not prevent the development of corneal neovascularization. PMID:23397320

  19. Quantification of corneal neovascularization after ex vivo limbal epithelial stem cell therapy

    PubMed Central

    Guarnieri, Adriano; Moreno-Montañés, Javier; Alfonso-Bartolozzi, Belén; Sabater, Alfonso L.; García-Guzmán, María; Andreu, Enrique J.; Prosper, Felipe

    2014-01-01

    AIM To assess cultured limbal epithelial stem cell transplantation in patients with limbal stem cell deficiency by analyzing and quantifying corneal neovascularization. METHODS This retrospective, interventional case series included eight eyes with total limbal stem cell deficiency. Ex vivo limbal epithelial stem cells were cultured on human amniotic membrane using an animal-free culture method. The clinical parameters of limbal stem cell deficiency, impression cytology, and quantification of corneal neovascularization were evaluated before and after cultured limbal stem cell transplantation. The area of corneal neovascularization, vessel caliber (VC), and invasive area (IA) were analyzed before and after stem cell transplantation by image analysis software. Best-corrected visual acuity (BCVA), epithelial transparency, and impression cytology were also measured. RESULTS One year after surgery, successful cases showed a reduction (improvement) of all three parameters of corneal neovascularization [neovascular area (NA), VC, IA], while failed cases did not. NA decreased a mean of 32.31% (P=0.035), invasion area 29.37% (P=0.018) and VC 14.29% (P=0.072). BCVA improved in all eyes (mean follow-up, 76±21mo). Epithelial transparency improved significantly from 2.00±0.93 to 0.88±1.25 (P=0.014). Impression cytology showed that three cases failed after limbal epithelial stem cell therapy before 1y of follow-up. CONCLUSION This method of analyzing and monitoring surface vessels is useful for evaluating the epithelial status during follow-up, as successful cases showed a bigger reduction in corneal neovascularization parameters than failed cases. Using this method, successful cases could be differentiated from failed cases. PMID:25540752

  20. SOD2 gene polymorphisms in neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

    PubMed Central

    Bessho, Hiroaki; Honda, Shigeru; Negi, Akira

    2009-01-01

    Purpose A nonsynonymous coding variant in the manganese superoxide dismutase (SOD2) gene (V16A, rs4880) has been implicated in neovascular age-related macular degeneration (AMD). However, the findings have been inconsistent. Two studies in Japanese populations reported an opposite direction of association of the same allele at the V16A variant, whereas one study in a Northern Irish population found no effect of the variant on the risk of developing neovascular AMD. To address these apparently contradictory reports, we validated the association in a Japanese population. Methods In a Japanese population, we genotyped the V16A variant in 116 neovascular AMD patients, 140 polypoidal choroidal vasculopathy (PCV) patients, and 189 control participants. This association was also tested in a population of PCV participants to avoid variable findings across studies due to underlying sample heterogeneity and because disease phenotype was not well described in previous studies. We analyzed a tagging single nucleotide polymorphism (SNP) in addition to the V16A variant to capture all common SOD2 variations verified by the HapMap project. Genotyping was conducted using TaqMan technology. Associations were tested using single-SNP and haplotype analyses as well as a meta-analysis of the published literature. Population stratification was also evaluated in our study population. Results We found no detectable association of the V16A variant or any other common SOD2 variation with either neovascular AMD or PCV, as demonstrated by both single-SNP and haplotype analyses. Population structure analyses precluded stratification artifacts in our study cohort. A meta-analysis of the association between the V16A variant and neovascular AMD also failed to detect a significant association. Conclusions We found no evidence to support the role of any common SOD2 variations including the V16A variant in the susceptibility to neovascular AMD or PCV. Our study highlights the importance and

  1. Triamcinolone Acetonide as an Adjunct to Bevacizumab for Prevention of Corneal Neovascularization in a Rat Model

    PubMed Central

    Mehrjardi, Hadi Z.; Ghaffari, Reza; Mahbod, Mirgholamreza; Hashemi, Hassan

    2014-01-01

    Purpose To evaluate the short-term effects of a single subconjunctival injection of triamcinolone acetonide as an adjunct to subconjunctival bevacizumab for prevention of corneal neovascularization in rats. Methods Chemical cauterization was performed in the central cornea of the right eye in 48 male Sprague-Dawley rats (4 eyes were excluded due to perforation and/or infection). Immediately after the injury, the rats were randomly assigned to four treatment groups: controls (n=10), received subconjunctival injection of 0.02 mL balanced salt solution; group 1 (n=12), received 0.02 mL bevacizumab (25 mg/mL); group 2 (n=11), were treated with 0.02 mL triamcinolone acetonide (40 mg/mL); and group 3 (n=11), received both bevacizumab and triamcinolone acetonide. On days 7 and 14 after cauterization, digital photographs of the corneas were taken and the area of neovascularization was calculated and compared among the study groups. Results The area of corneal neovascularization in all three treatment groups was less than the controls (P<0.05 for all comparisons). On day 7, the corneal avascular area was largest in group 3 (63%). On day 14, the area of corneal neovascularization in groups 2 and 3 was smaller than that in group 1 (P=0.031 and 0.011, respectively), but the difference between groups 2 and 3 was not statistically significant (P=0.552). Microscopic evaluation of the cornea was compatible with gross findings; inflammation and the number of new vessels was the least in group 3. Conclusion Triamcinolone acetonide was more effective than bevacizumab in inhibiting corneal neovascularization. Its adjunctive administration to bevacizumab resulted in even better prevention of corneal neovascularization. However, the produced combined effect was less than the sum of their separate effects and did not match additive or synergistic interactions. PMID:25279116

  2. Autologous bone-marrow mesenchymal cell induced chondrogenesis (MCIC).

    PubMed

    Huh, Sung Woo; Shetty, Asode Ananthram; Ahmed, Saif; Lee, Dong Hwan; Kim, Seok Jung

    2016-01-01

    Degenerative and traumatic articular cartilage defects are common, difficult to treat, and progressive lesions that cause significant morbidity in the general population. There have been multiple approaches to treat such lesions, including arthroscopic debridement, microfracture, multiple drilling, osteochondral transplantation and autologous chondrocyte implantation (ACI) that are currently being used in clinical practice. Autologous bone-marrow mesenchymal cell induced chondrogenesis (MCIC) is a single-staged arthroscopic procedure. This method combines a modified microfracture technique with the application of a bone marrow aspirate concentrate (BMAC), hyaluronic acid and fibrin gel to treat articular cartilage defects. We reviewed the current literatures and surgical techniques for mesenchymal cell induced chondrogenesis. PMID:27489409

  3. Imaging polarimetry in patients with neovascular age-related macular degeneration

    NASA Astrophysics Data System (ADS)

    Elsner, Ann E.; Weber, Anke; Cheney, Michael C.; Vannasdale, Dean A.; Miura, Masahiro

    2007-05-01

    Imaging polarimetry was used to examine different components of neovascular membranes in age-related macular degeneration. Retinal images were acquired with a scanning laser polarimeter. An innovative pseudocolor scale, based on cardinal directions of color, displayed two types of image information: relative phases and magnitudes of birefringence. Membranes had relative phase changes that did not correspond to anatomical structures in reflectance images. Further, membrane borders in depolarized light images had significantly higher contrasts than those in reflectance images. The retinal birefringence in neovascular membranes indicates optical activity consistent with molecular changes rather than merely geometrical changes.

  4. Regulation of signaling events involved in the pathophysiology of neovascular AMD

    PubMed Central

    Wang, Haibo

    2016-01-01

    Neovascular age-related macular degeneration (AMD) is a complex disease in which an individual’s genetic predisposition is affected by aging and environmental stresses, which trigger signaling pathways involving inflammation, oxidation, and/or angiogenesis in the RPE cells and choroidal endothelial cells (CECs), to lead to vision loss from choroidal neovascularization. Antiangiogenic therapies have greatly improved clinical outcomes in the last decade; however, vision improves in less than half of patients treated for neovascular AMD, and treatments remain inadequate for atrophic AMD. Many studies focus on genetic predisposition or the association of outcomes in trials of human neovascular AMD but are unable to evaluate the effects between different cell types involved in AMD and the signaling events that take place to cause pathologic biologic events. This manuscript complements other reviews in that it describes what is known generally in human AMD studies and clinical trials testing methods to inhibit vascular endothelial growth factor (VEGF inhibitors) and presents pathologic signaling events that develop in two important cell types, the RPE cells and the CECs, when stimulated by stresses or placed into conditions similar to what is currently understood to occur in neovascular AMD. This manuscript complements other reviews by discussing signaling events that are activated by cell–cell or cell–matrix interactions. These considerations are particularly important when considering growth factors, such as VEGF, which are important in physiologic and pathologic processes, or GTPases that are present but active only if GTP bound. In either case, it is essential to understand the role of signaling activation to distinguish what is pathologic from what is physiologic. Particularly important is the essential role of activated Rac1 in CEC transmigration of the RPE monolayer, an important step in blindness associated with neovascular AMD. Other concepts discussed

  5. Successful treatment of melanocytoma associated choroidal neovascular membrane with intravitreal bevacizumab.

    PubMed

    Al-Halafi, Ali M

    2013-04-01

    Melanocytoma of the optic disc is a benign melanocytic tumour that rarely causes visual impairment. We report a rare case of choroidal neovascularization (CNV) in association with optic disc melanocytoma and its response to intravitreal injection of the anti-vascular endothelial growth factor (VEGF), bevacizumab. The choroidal neovascular membrane regressed following a single intravitreal bevacizumab injection with formation of a scar. CNV associated with optic disc melanocytoma is rare. Intravitreal anti-VEGF treatment may be an effective treatment for CNV associated with optic disc melanocytoma. PMID:24227972

  6. Multiply scattered light tomography and confocal imaging: detecting neovascularization in age-related macular degeneration

    NASA Astrophysics Data System (ADS)

    Elsner, Ann E.; Miura, Masahiro; Burns, Stephen Allan; Beausencourt, E.; Kunze, C.; Kelley, L. M.; Walker, J. P.; Wing, G. L.; Raskauskas, P. A.; Fletcher, D. C.; Zhou, Qienyuan; Dreher, Andreas W.

    2000-07-01

    A novel technique, Multiply Scattered Light Tomography (MSLT), and confocal Infrared Imaging are used to provide diagnostic information using a comfortable, rapid, and noninvasive method. We investigated these techniques in detecting neovascularization in age-related macular degeneration. The MSLT used a Vertical Cavity Surface Emitting Laser (VCSEL) at 850 nm, while the confocal imaging technique used either the VCSEL or a 790 nm laser diode. Both were implemented into the topographical scanning system (TopSS, Laser Diagnostic Technologies, Inc.) Confocal imaging with both lasers provided different information about neovascularization as a function of focal plane, and different also from MSLT.

  7. Suppression of Experimental Choroidal Neovascularization by Curcumin in Mice

    PubMed Central

    Xie, Ping; Zhang, WeiWei; Yuan, Songtao; Chen, Zhiqiang; Yang, Qin; Yuan, DongQing; Wang, Feng; Liu, QingHuai

    2012-01-01

    Purpose To investigate the effects of curcumin on the development of experimental choroidal neovascularization (CNV) with underlying cellular and molecular mechanisms. Methods C57BL/6N mice were pretreated with intraperitoneal injections of curcumin daily for 3 days prior to laser-induced CNV, and the drug treatments were continued until the end of the study. The CNV area was analyzed by fluorescein-labeled dextran angiography of retinal pigment epithelium (RPE)-choroid flat mounts on day 7 and 14, and CNV leakage was evaluated by fluorescein angiography (FA) on day 14 after laser photocoagulation. The infiltration of F4/80 positive macrophages and GR-1 positive granulocytes were evaluated by immunohistochemistry on RPE-choroid flat mounts on day 3. Their expression in RPE-choroid complex was quantified by real-time PCR (F4/80) and Western blotting (GR-1) on day 3. RPE-choroid levels of vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-α, monocyte chemotactic protein (MCP)-1, and intercellular adhesion molecule (ICAM)-1 were examined by ELISA on day 3. Double immunostaining of F4/80 and VEGF was performed on cryo-sections of CNV lesions on day 3. The expression of nuclear factor (NF)-κB and hypoxia-inducible factor (HIF)−1α in the RPE-choroid was determined by Western blotting. Results Curcumin-treated mice had significantly less CNV area (P<0.05) and CNV leakage (P<0.001) than vehicle-treated mice. Curcumin treatment led to significant inhibition of F4/80 positive macrophages (P<0.05) and GR-1 positive granulocytes infiltration (P<0.05). VEGF mainly expressed in F4/80 positive macrophages in laser injury sites, which was suppressed by curcumin treatment (P<0.01). Curcumin inhibited the RPE-choroid levels of TNF-α (P<0.05), MCP-1 (P<0.05) and ICAM-1 (P<0.05), and suppressed the activation of NF-κB in nuclear extracts (P<0.05) and the activation of HIF−1α (P<0.05). Conclusion Curcumin treatment led to the suppression of CNV development

  8. MicroRNAs as potential novel therapeutic targets and tools for regulating paracrine function of endothelial progenitor cells

    PubMed Central

    Xu, Shengjie; Jin, Chongying; Shen, Xiaohua; Ding, Fang; Zhu, Junhui; Fu, Guosheng

    2012-01-01

    Summary Endothelial progenitor cells (EPCs) play a protective role in the cardiovascular system by enhancing the maintenance of endothelium homeostasis and the process of new vessel formation. Recent studies show that EPCs may induce vascular regeneration and neovascularization mainly through paracrine signaling, that is, through the secretion of growth factors and pro-angiogenic cytokines [1]. However, multiple factors might function synergistically and therefore make it difficult to manipulate EPC paracrine effects. MicroRNAs, a family of small, non-coding RNAs, are characterized by post-transcriptionally regulating multiple functionally related genes, which renders them potentially powerful therapeutic targets or tools. In this paper we propose the hypothesis that microRNAs can be utilized as a novel therapeutic strategy for regulating EPC paracrine secretion. PMID:22739741

  9. Hedgehog Signaling Components Are Expressed in Choroidal Neovascularization in Laser-induced Retinal Lesion

    PubMed Central

    Nochioka, Katsunori; Okuda, Hiroaki; Tatsumi, Kouko; Morita, Shoko; Ogata, Nahoko; Wanaka, Akio

    2016-01-01

    Choroidal neovascularization is one of the major pathological changes in age-related macular degeneration, which causes devastating blindness in the elderly population. The molecular mechanism of choroidal neovascularization has been under extensive investigation, but is still an open question. We focused on sonic hedgehog signaling, which is implicated in angiogenesis in various organs. Laser-induced injuries to the mouse retina were made to cause choroidal neovascularization. We examined gene expression of sonic hedgehog, its receptors (patched1, smoothened, cell adhesion molecule down-regulated by oncogenes (Cdon) and biregional Cdon-binding protein (Boc)) and downstream transcription factors (Gli1-3) using real-time RT-PCR. At seven days after injury, mRNAs for Patched1 and Gli1 were upregulated in response to injury, but displayed no upregulation in control retinas. Immunohistochemistry revealed that Patched1 and Gli1 proteins were localized to CD31-positive endothelial cells that cluster between the wounded retina and the pigment epithelium layer. Treatment with the hedgehog signaling inhibitor cyclopamine did not significantly decrease the size of the neovascularization areas, but the hedgehog agonist purmorphamine made the areas significantly larger than those in untreated retina. These results suggest that the hedgehog-signaling cascade may be a therapeutic target for age-related macular degeneration. PMID:27239075

  10. Role of PTFE Patch Saphenoplasty in Reducing Neovascularization and Recurrence in Varicose Veins.

    PubMed

    Vashist, M G; Singhal, Nitin; Verma, Manish; Sen, Jyotsana

    2015-12-01

    Varicose veins have a high recurrence rate following surgery. Besides poor surgical technique, majority of these recurrences are attributable to neovascularization after both primary and repeat surgery. Authors have studied the effectiveness of a polytetrafluoroethylene (PTFE) patch interposition between the ligated vein stump and the overlying soft tissue at saphenofemoral junction in decreasing recurrence of varicose veins after initial surgery. Study was conducted on 50 patients of varicose veins with saphenofemoral junction incompetence. Patients were randomly divided into two groups, group A and group B alternately. In group A, standard surgical procedure was done followed by PTFE patch application. In group B, same surgical procedure was applied as in group A, with the exception of PTFE patch application. Patients in both groups were given similar postoperative care. A full venous duplex ultrasound assessment was performed in all the patients postoperatively. Neovascularization was observed in five patients (20 %) of group B, while it was not seen in any of the patients in group A at 1-year follow-up. This difference in neovascularization across the two groups was found to be statistically significant with a p value of 0.0251. Hence, authors concluded that patch saphenoplasty helps in reducing recurrence in varicose veins by decreasing neovascularization at saphenofemoral junction. PMID:27011514

  11. Antivascular Endothelial Growth Factor Agents for Neovascular Age-Related Macular Degeneration

    PubMed Central

    Zampros, Ilias; Praidou, Anna; Brazitikos, Periklis; Ekonomidis, Panagiotis; Androudi, Sofia

    2012-01-01

    Age-related macular degeneration (AMD) is the leading cause of severe visual loss and blindness over the age of 50 in developed countries. Vascular endothelial growth factor (VEGF) is considered as a critical molecule in the pathogenesis of choroidal neovascularization (CNV), which characterizes the neovascular AMD. Anti-VEGF agents are considered the most promising way of effectively inhibition of the neovascular AMD process. VEGF is a heparin-binding glycoprotein with potent angiogenic, mitogenic and vascular permeability-enhancing activities specific for endothelial cells. Two anti-VEGF agents have been approved by the US Food and Drug Administration (FDA) for the treatment of neovascular AMD. Pegaptanib sodium, which is an aptamer and ranibizumab, which is a monoclonal antibody fragment. Another humanized monoclonal antibody is currently off-label used, bevacizumab. This paper aims to discuss in details the effectiveness, the efficacy and safety of these three anti-VEGF agents. New anti-VEGF compounds which are recently investigated for their clinical usage (VEGF-trap, small interfering RNA) are also discussed for their promising outcomes. PMID:22174998

  12. Treatment of neovascular age-related macular degeneration in patients with diabetes

    PubMed Central

    Cummings, Michael; Cunha-Vaz, José

    2008-01-01

    The number of patients with type 2 diabetes continues to rise; an anticipated 300 million people will be affected by 2025. The immense social and economic burden of the condition is exacerbated by the initial asymptomatic nature of type 2 diabetes, resulting in a high prevalence of micro-and macrovascular complications at presentation. Diabetic retinopathy, one of the potential microvascular complications associated with diabetes, and neovascular age-related macular degeneration (AMD) are the two most frequent retinal degenerative diseases, and are responsible for the majority of blindness due to retinal disease. Both conditions predominantly affect the central macula, and are associated with the presence of retinal edema and an aggressive inflammatory repair process that accelerates disease progression. The associated retinal edema and the inflammatory repair process are directly involved in the breakdown of the blood-retinal barrier (BRB). Yet, the underlying alterations to the BRB caused by the diseases are very different. The coexistence of the two conditions appears to be relatively uncommon, suggesting that diabetes may even protect patients from developing neovascular AMD. However, it is thought that the inflammatory repair responses associated with diabetic retinopathy and neovascular AMD may be cumulative and, in patients affected by both, could result in chronic diffuse cystoid edema. Treatment considerations in such patients should, therefore, include the role of retinal edema and the increased susceptibility of patients with diabetes to potential systemic side effects associated with agents administered repeatedly for neovascular AMD treatment. PMID:19668728

  13. SOCS3 in retinal neurons and glial cells suppresses VEGF signaling to prevent pathological neovascular growth

    PubMed Central

    Sun, Ye; Ju, Meihua; Lin, Zhiqiang; Fredrick, Thomas W.; Evans, Lucy P.; Tian, Katherine T.; Saba, Nicholas J.; Morss, Peyton C.; Pu, William T.; Chen, Jing; Stahl, Andreas; Joyal, Jean-Sébastien; Smith, Lois E. H.

    2015-01-01

    Neurons and glial cells in the retina contribute to neovascularization, or the formation of abnormal new blood vessels, in proliferative retinopathy, a condition that can lead to vision loss or blindness. We identified a mechanism by which suppressor of cytokine signaling 3 (SOCS3) in neurons and glial cells prevents neovascularization. We found that Socs3 expression was increased in the retinal ganglion cell and inner nuclear layers after oxygen-induced retinopathy. Mice with Socs3 deficiency in neuronal and glial cells had substantially reduced vaso-obliterated retinal areas and increased pathological retinal neovascularization in response to oxygen-induced retinopathy, suggesting that loss of neuronal/glial SOCS3 increased both retinal vascular regrowth and pathological neovascularization. Furthermore, retinal expression of Vegfa (which encodes vascular endothelial growth factor A) was higher in these mice than in Socs3 flox/flox controls, indicating that neuronal and glial Socs3 suppressed Vegfa expression during pathological conditions. Lack of neuronal and glial SOCS3 resulted in greater phosphorylation and activation of STAT3, which led to increased expression of its gene target Vegfa, and increased endothelial cell proliferation. In summary, SOCS3 in neurons and glial cells inhibited the STAT3-mediated secretion of VEGF from these cells, which suppresses endothelial cell activation, resulting in decreased endothelial cell proliferation and angiogenesis. These results suggest that neuronal and glial cell SOCS3 limits pathological retinal angiogenesis by suppressing VEGF signaling. PMID:26396267

  14. Skin autofluorescence is elevated in neovascular age-related macular degeneration.

    PubMed

    Mulder, D J; Bieze, M; Graaff, R; Smit, A J; Hooymans, J M M

    2010-05-01

    BACKGROUND/AIMS Skin autofluorescence (AF) is a non-invasive marker for advanced glycation endproducts (AGE) in tissues, making use of their characteristic AF pattern. The aim of this study was to investigate whether skin AF is increased in patients with neovascular age-related macular degeneration (AMD) compared with healthy controls. METHODS Skin AF was assessed in 73 consecutive patients with active and documented neovascular AMD without evidence for diabetic or hypertensive retinopathy and in 31 healthy age-matched controls. Exclusion criteria were: known renal disease, current inflammatory or malignant disease, or skin type V or VI. Skin AF was measured on the forearm and was calculated as a ratio of mean intensities detected from the skin between 420-600 and 300-420 nm. Student t test and chi(2) test were used to compare differences between groups. RESULTS Skin AF was increased in neovascular AMD compared with controls (2.57+/-0.68 vs 2.23+/-0.63 arbitrary units x 10(-2); p=0.018). In patients without vascular risk factors or cardiovascular disease, skin AF was not significantly higher than that of the controls. Skin AF correlated with age in both patients and controls. CONCLUSION Skin AF is increased in patients with neovascular AMD, suggesting that AMD is accompanied by enhanced systemic AGE accumulation, which may indicate a role in the pathophysiology of AMD. PMID:19726430

  15. Differences in spectral absorption properties between active neovascular macular degeneration and mild age related maculopathy.

    PubMed

    Balaskas, Konstantinos; Nourrit, Vincent; Dinsdale, Michelle; Henson, David B; Aslam, Tariq

    2013-05-01

    This study examines the differences in spectral absorption properties between the maculae of patients with active neovascular macular degeneration and those with early age related maculopathy (ARM). Patients attending for management of neovascular age related macular degeneration (AMD) underwent multispectral imaging with a system comprising of a modified digital fundus camera coupled with a 250-W tungsten-halogen lamp and a liquid crystal fast-tuneable filter. Images were obtained at 8 wavelengths between 496 and 700 nm. Aligned images were used to generate a DLA (differential light absorption, a measure of spectral absorption properties) map of the macular area. DLA maps were generated for both eyes of 10 sequential patients attending for anti-vascular endothelial growth factor injections. Each of these patients had active leaking neovascular AMD in one eye and early ARM or milder disease in the fellow eye. Eyes with neovascular AMD demonstrated lower average levels of DLA compared with their fellow eyes with early ARM (p=0.037, t test). The significant difference in DLA demonstrates the potential of multispectral imaging for differentiating the two pathologies non-invasively. PMID:23137662

  16. Hedgehog Signaling Components Are Expressed in Choroidal Neovascularization in Laser-induced Retinal Lesion.

    PubMed

    Nochioka, Katsunori; Okuda, Hiroaki; Tatsumi, Kouko; Morita, Shoko; Ogata, Nahoko; Wanaka, Akio

    2016-04-28

    Choroidal neovascularization is one of the major pathological changes in age-related macular degeneration, which causes devastating blindness in the elderly population. The molecular mechanism of choroidal neovascularization has been under extensive investigation, but is still an open question. We focused on sonic hedgehog signaling, which is implicated in angiogenesis in various organs. Laser-induced injuries to the mouse retina were made to cause choroidal neovascularization. We examined gene expression of sonic hedgehog, its receptors (patched1, smoothened, cell adhesion molecule down-regulated by oncogenes (Cdon) and biregional Cdon-binding protein (Boc)) and downstream transcription factors (Gli1-3) using real-time RT-PCR. At seven days after injury, mRNAs for Patched1 and Gli1 were upregulated in response to injury, but displayed no upregulation in control retinas. Immunohistochemistry revealed that Patched1 and Gli1 proteins were localized to CD31-positive endothelial cells that cluster between the wounded retina and the pigment epithelium layer. Treatment with the hedgehog signaling inhibitor cyclopamine did not significantly decrease the size of the neovascularization areas, but the hedgehog agonist purmorphamine made the areas significantly larger than those in untreated retina. These results suggest that the hedgehog-signaling cascade may be a therapeutic target for age-related macular degeneration. PMID:27239075

  17. Photothrombosis of Corneal Neovascularization by Photodynamic Therapy Utilizing Verteporfin and Diode Laser

    PubMed Central

    Ahmed Hassan, Aziza; Foad Ghoneim, Dina; Abdelraheem El-dib, Amr; Abdelkawi Ahmed, Salwa; Abdel- Salam, Ahmed Medhat

    2013-01-01

    Introduction: The aim of the present study was to evaluate the effect of photodynamic therapy in the treatment of experimental corneal neovascularization (NV) with benzoporphyrin derivative (BPD). Methods: One group was considered as control (n=6 eyes) then, corneal NV was induced in 30 New Zealand male rabbits (n=60 eyes) by placing 7.0 silk sutures at midstromal depth approximately1mm from the limbus. Fifteen rabbits with corneal NV were left without any treatment, and 15 rabbits were subjected to photodynamic therapy (PDT) by intravenous injection with Verteporfin at a dose of 1.5 mg /Kg. Diode laser (660 nm) was applied after 15 minutes for 5 minutes with a power of 50 mW/cm2. All rabbits were successively followed up by slit lamp examination for periods of 1 day, 1, 2, 3 and 4 weeks. Three rabbits were selected and sacrificed weekly (n=6 eyes each) and the corneas were isolated for histopathological examination. Results: The results of slit lamp examination indicated the gradual regression of the cornea neovascularization 4 weeks of PDT. Furthermore, regression of corneal neovascularization was documented clinically by decrease number and length of blood vessels and by histopathological examination. Conclusion: PDT with Verteporfin can provide efficacious treatment of corneal neovascularization. PMID:25606321

  18. A Hypoxia-Responsive Glial Cell–Specific Gene Therapy Vector for Targeting Retinal Neovascularization

    PubMed Central

    Biswal, Manas R.; Prentice, Howard M.; Dorey, C. Kathleen; Blanks, Janet C.

    2014-01-01

    Purpose. Müller cells, the major glial cell in the retina, play a significant role in retinal neovascularization in response to tissue hypoxia. We previously designed and tested a vector using a hypoxia-responsive domain and a glial fibrillary acidic protein (GFAP) promoter to drive green fluorescent protein (GFP) expression in Müller cells in the murine model of oxygen-induced retinopathy (OIR). This study compares the efficacy of regulated and unregulated Müller cell delivery of endostatin in preventing neovascularization in the OIR model. Methods. Endostatin cDNA was cloned into plasmids with hypoxia-regulated GFAP or unregulated GFAP promoters, and packaged into self-complementary adeno-associated virus serotype 2 vectors (scAAV2). Before placement in hyperoxia on postnatal day (P)7, mice were given intravitreal injections of regulated or unregulated scAAV2, capsid, or PBS. Five days after return to room air, on P17, neovascular and avascular areas, as well as expression of the transgene and vascular endothelial growth factor (VEGF), were compared in OIR animals treated with a vector, capsid, or PBS. Results. The hypoxia-regulated, glial-specific, vector-expressing endostatin reduced neovascularization by 93% and reduced the central vaso-obliteration area by 90%, matching the results with the unregulated GFAP-Endo vector. Retinas treated with the regulated endostatin vector expressed substantial amounts of endostatin protein, and significantly reduced VEGF protein. Endostatin production from the regulated vector was undetectable in retinas with undamaged vasculature. Conclusions. These findings suggest that the hypoxia-regulated, glial cell–specific vector expressing endostatin may be useful for treatment of neovascularization in proliferative diabetic retinopathy. PMID:25377223

  19. Ocular neovascularization in eyes with a central retinal artery occlusion or a branch retinal artery occlusion

    PubMed Central

    Mason, John O; Patel, Shyam A; Feist, Richard M; Albert, Michael A; Huisingh, Carrie; McGwin, Gerald; Thomley, Martin L

    2015-01-01

    Purpose To investigate the ocular neovascularization (ONV) rate in eyes with a branch retinal artery occlusion (BRAO) or a central retinal artery occlusion (CRAO), and to study factors that may influence the ONV rate secondary to CRAO. Methods This was a retrospective case series of consecutive patients (286 total eyes: 83 CRAOs and 203 BRAOs) who were diagnosed with a retinal artery occlusion from 1998 to 2013 at the Retina Consultants of Alabama and University of Alabama at Birmingham, Birmingham, AL, USA. Generalized estimating equations were used to evaluate the association between hypothesized risk factors and ONV development. Results Twelve (14.5%) of the 83 eyes with a CRAO developed ONV. Eleven of 12 eyes (91.7%) had iris neovascularization, ten of 12 eyes (83.3%) had neovascular glaucoma, and two of 12 eyes (16.7%) had neovascularization of the optic disc. The average time for ONV development secondary to CRAO was 30.7 days, ranging from the date of presentation to 137 days. Only two (<1.0%) of the 203 eyes with a BRAO developed iris neovascularization. Diabetes mellitus type 2 was a risk factor for ONV development following a CRAO with an adjusted odds ratio of 5.2 (95% confidence interval: 1.4–19.8) (P=0.02). Conclusion ONV is an important complication of CRAO and is a less-frequent complication of BRAO. Patients with a CRAO, especially those with diabetes mellitus type 2, should be closely monitored for the first 6 months for ONV. PMID:26089631

  20. Honokiol inhibits pathological retinal neovascularization in oxygen-induced retinopathy mouse model

    SciTech Connect

    Vavilala, Divya Teja; O’Bryhim, Bliss E.; Ponnaluri, V.K. Chaithanya; White, R. Sid; Radel, Jeff; Symons, R.C. Andrew; Mukherji, Mridul

    2013-09-06

    Highlights: •Aberrant activation of HIF pathway is the underlying cause of ischemic neovascularization. •Honokiol has better therapeutic index as a HIF inhibitor than digoxin and doxorubicin. •Daily IP injection of honokiol in OIR mouse model reduced retinal neovascularization. •Honokiol also prevents vaso-obliteration, the characteristic feature of the OIR model. •Honokiol enhanced physiological revascularization of the retinal vascular plexuses. -- Abstract: Aberrant activation of the hypoxia inducible factor (HIF) pathway is the underlying cause of retinal neovascularization, one of the most common causes of blindness worldwide. The HIF pathway also plays critical roles during tumor angiogenesis and cancer stem cell transformation. We have recently shown that honokiol is a potent inhibitor of the HIF pathway in a number of cancer and retinal pigment epithelial cell lines. Here we evaluate the safety and efficacy of honokiol, digoxin, and doxorubicin, three recently identified HIF inhibitors from natural sources. Our studies show that honokiol has a better safety to efficacy profile as a HIF inhibitor than digoxin and doxorubicin. Further, we show for the first time that daily intraperitoneal injection of honokiol starting at postnatal day (P) 12 in an oxygen-induced retinopathy (OIR) mouse model significantly reduced retinal neovascularization at P17. Administration of honokiol also prevents the oxygen-induced central retinal vaso-obliteration, characteristic feature of the OIR model. Additionally, honokiol enhanced physiological revascularization of the retinal vascular plexuses. Since honokiol suppresses multiple pathways activated by HIF, in addition to the VEGF signaling, it may provide advantages over current treatments utilizing specific VEGF antagonists for ocular neovascular diseases and cancers.

  1. High-mobility group box 1 activates integrin-dependent homing of endothelial progenitor cells.

    PubMed

    Chavakis, Emmanouil; Hain, Andreas; Vinci, Maria; Carmona, Guillaume; Bianchi, Marco E; Vajkoczy, Peter; Zeiher, Andreas M; Chavakis, Triantafyllos; Dimmeler, Stefanie

    2007-02-01

    Endothelial progenitor cells (EPCs) are recruited to ischemic regions and improve neovascularization. Integrins contribute to EPC homing. High-mobility group box 1 (HMGB1) is a nuclear protein that is released extracellularly on cell necrosis and tissue damage, eliciting a proinflammatory response and stimulating tissue repair. In the present study, we investigated the effects of HMGB1 on EPC homing. EPCs express the HMGB1 receptors RAGE (receptor for advanced glycation end products) and TLR2 (Toll-like receptor 2). EPC migration was stimulated by HMGB1 in a RAGE-dependent manner. In addition, the HMGB1-induced migration of EPCs on fibronectin and fibrinogen was significantly inhibited by antibodies against beta1 and beta2 integrins, respectively. Short-term prestimulation of EPCs with HMGB1 also increased EPC adhesion to endothelial cell monolayers, and this effect was blocked by antibodies to beta2 integrins or RAGE. HMGB1 increased EPC adhesion to the immobilized integrin ligands intercellular adhesion molecule-1 and fibronectin in a RAGE-dependent manner. Strikingly, HMGB1 rapidly increased integrin affinity and induced integrin polarization. Using intravital microscopy in a tumor model of neovascularization, prestimulation of EPCs with HMGB1 enhanced the initial in vivo adhesion of EPCs to microvessels and the recruitment of EPCs in the tumor tissue. In addition, prestimulation of EPCs with HMGB1 increased the homing of EPCs to ischemic muscles. In conclusion, these data represent a link between HMGB1 and integrin functions of EPCs and demonstrate that HMGB1 stimulates EPC homing to ischemic tissues. These results may provide a platform for the development of novel therapeutic approaches to improve EPC homing. PMID:17218606

  2. CD34+ Cells Represent Highly Functional Endothelial Progenitor Cells in Murine Bone Marrow

    PubMed Central

    Yang, Junjie; Ii, Masaaki; Kamei, Naosuke; Alev, Cantas; Kwon, Sang-Mo; Kawamoto, Atsuhiko; Akimaru, Hiroshi; Masuda, Haruchika; Sawa, Yoshiki; Asahara, Takayuki

    2011-01-01

    Background Endothelial progenitor cells (EPCs) were shown to have angiogenic potential contributing to neovascularization. However, a clear definition of mouse EPCs by cell surface markers still remains elusive. We hypothesized that CD34 could be used for identification and isolation of functional EPCs from mouse bone marrow. Methodology/Principal Findings CD34+ cells, c-Kit+/Sca-1+/Lin− (KSL) cells, c-Kit+/Lin− (KL) cells and Sca-1+/Lin− (SL) cells were isolated from mouse bone marrow mononuclear cells (BMMNCs) using fluorescent activated cell sorting. EPC colony forming capacity and differentiation capacity into endothelial lineage were examined in the cells. Although CD34+ cells showed the lowest EPC colony forming activity, CD34+ cells exhibited under endothelial culture conditions a more adherent phenotype compared with the others, demonstrating the highest mRNA expression levels of endothelial markers vWF, VE-cadherin, and Flk-1. Furthermore, a dramatic increase in immediate recruitment of cells to the myocardium following myocardial infarction and systemic cell injection was observed for CD34+ cells comparing with others, which could be explained by the highest mRNA expression levels of key homing-related molecules Integrin β2 and CXCR4 in CD34+ cells. Cell retention and incorporation into the vasculature of the ischemic myocardium was also markedly increased in the CD34+ cell-injected group, giving a possible explanation for significant reduction in fibrosis area, significant increase in neovascularization and the best cardiac functional recovery in this group in comparison with the others. Conclusion These findings suggest that mouse CD34+ cells may represent a functional EPC population in bone marrow, which could benefit the investigation of therapeutic EPC biology. PMID:21655289

  3. Secretome From Mesenchymal Stem Cells Induces Angiogenesis Via Cyr61

    PubMed Central

    ESTRADA, ROSENDO; LI, NA; SAROJINI, HARSHINI; AN, JIN; LEE, MENQ-JER; WANG, EUGENIA

    2010-01-01

    It is well known that bone marrow-derived mesenchymal stem cells (MSCs) are involved in wound healing and regeneration responses. In this study, we globally profiled the proteome of MSCs to investigate critical factor(s) that may promote wound healing. Cysteine-rich protein 61 (Cyr61) was found to be abundantly present in MSCs. The presence of Cyr61 was confirmed by immunofluorescence staining and immunoblot analysis. Moreover, we showed that Cyr61 is present in the culture medium (secretome) of MSCs. The secretome of MSCs stimulates angiogenic response in vitro, and neovascularization in vivo. Depletion of Cyr61 completely abrogates the angiogenic-inducing capability of the MSC secretome. Importantly, addition of recombinant Cyr61 polypeptides restores the angiogenic activity of Cyr61-depleted secretome. Collectively, these data demonstrate that Cyr61 polypeptide in MSC secretome contributes to the angiogenesis-promoting activity, a key event needed for regeneration and repair of injured tissues. PMID:19170074

  4. Perivascular support of human hematopoietic stem/progenitor cells

    PubMed Central

    Corselli, Mirko; Chin, Chee Jia; Parekh, Chintan; Sahaghian, Arineh; Wang, Wenyuan; Ge, Shundi; Evseenko, Denis; Wang, Xiaoyan; Montelatici, Elisa; Lazzari, Lorenza; Crooks, Gay M.

    2013-01-01

    Hematopoietic stem and progenitor cells (HSPCs) emerge and develop adjacent to blood vessel walls in the yolk sac, aorta-gonad-mesonephros region, embryonic liver, and fetal bone marrow. In adult mouse bone marrow, perivascular cells shape a “niche” for HSPCs. Mesenchymal stem/stromal cells (MSCs), which support hematopoiesis in culture, are themselves derived in part from perivascular cells. In order to define their direct role in hematopoiesis, we tested the ability of purified human CD146+ perivascular cells, as compared with unfractionated MSCs and CD146− cells, to sustain human HSPCs in coculture. CD146+ perivascular cells support the long-term persistence, through cell-to-cell contact and at least partly via Notch activation, of human myelolymphoid HSPCs able to engraft primary and secondary immunodeficient mice. Conversely, unfractionated MSCs and CD146− cells induce differentiation and compromise ex vivo maintenance of HSPCs. Moreover, CD146+ perivascular cells express, natively and in culture, molecular markers of the vascular hematopoietic niche. Unexpectedly, this dramatic, previously undocumented ability to support hematopoietic stem cells is present in CD146+ perivascular cells extracted from the nonhematopoietic adipose tissue. PMID:23412095

  5. The progenitors of stripped-envelope supernovae

    NASA Astrophysics Data System (ADS)

    Elias-Rosa, N.

    2013-05-01

    The type Ib/c SNe are those explosions which come from massive star populations, but lack hydrogen and helium. These have been proposed to originate in the explosions of massive Wolf-Rayet stars, and we should easily be able to detect the very luminous, young progenitors if they exist. However, there has not been any detection of progenitors so far. I present the study of two extinguished Type Ic SNe 2003jg and 2004cc. In both cases there is no clear evidence of a direct detection of their progenitors in deep pre-explosion images. Upper limits derived by inserting artificial stars of known brightness at random positions around the progenitor positions (M_v>-8.8 and M_v>-9 magnitudes for the progenitors of SN 2003jg and SN 2004cc, respectively) are brighter than those expected for a massive WC (Wolf-Rayet, carbon-rich) or WO (Wolf-Rayet, oxygen-rich) (e.g., approximately between -3 and -6 in the LMC). Therefore, this is perhaps further evidence that the most massive stars may give rise to black-holes forming SNe, or it is an undetected, compact massive star hidden by a thick dust lane. However the extinction toward these SNe is currently one of the largest known. Even if these results do not directly reveal the nature of the type Ic SN progenitors, they can help to characterize the dusty environment which surrounded the progenitor of the stripped-envelope CC-SNe.

  6. Progenitor's Signatures in Type Ia Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Chiotellis, A.; Kosenko, D.; Schure, K. M.; Vink, J.

    2013-01-01

    The remnants of Type Ia supernovae (SNe Ia) can provide important clues about their progenitor histories. We discuss two well-observed supernova remnants (SNRs) that are believed to have resulted from SNe Ia, and use various tools to shed light on the possible progenitor histories. We find that Kepler's SNR is consistent with a symbiotic binary progenitor consisting of a white dwarf and an AGB star. Our hydrosimulations can reproduce the observed kinematic and morphological properties. For Tycho's remnant we use the characteristics of the X-ray spectrum and kinematics to show that the ejecta has likely interacted with dense circumstellar gas.

  7. Progenitor genealogy in the developing cerebral cortex.

    PubMed

    Laguesse, Sophie; Peyre, Elise; Nguyen, Laurent

    2015-01-01

    The mammalian cerebral cortex is characterized by a complex histological organization that reflects the spatio-temporal stratifications of related stem and neural progenitor cells, which are responsible for the generation of distinct glial and neuronal subtypes during development. Some work has been done to shed light on the existing filiations between these progenitors as well as their respective contribution to cortical neurogenesis. The aim of the present review is to summarize the current views of progenitor hierarchy and relationship in the developing cortex and to further discuss future research directions that would help us to understand the molecular and cellular regulating mechanisms involved in cerebral corticogenesis. PMID:25141969

  8. Defining response to anti-VEGF therapies in neovascular AMD

    PubMed Central

    Amoaku, W M; Chakravarthy, U; Gale, R; Gavin, M; Ghanchi, F; Gibson, J; Harding, S; Johnston, R L; Kelly, S; Lotery, A; Mahmood, S; Menon, G; Sivaprasad, S; Talks, J; Tufail, A; Yang, Y

    2015-01-01

    The introduction of anti-vascular endothelial growth factor (anti-VEGF) has made significant impact on the reduction of the visual loss due to neovascular age-related macular degeneration (n-AMD). There are significant inter-individual differences in response to an anti-VEGF agent, made more complex by the availability of multiple anti-VEGF agents with different molecular configurations. The response to anti-VEGF therapy have been found to be dependent on a variety of factors including patient's age, lesion characteristics, lesion duration, baseline visual acuity (VA) and the presence of particular genotype risk alleles. Furthermore, a proportion of eyes with n-AMD show a decline in acuity or morphology, despite therapy or require very frequent re-treatment. There is currently no consensus as to how to classify optimal response, or lack of it, with these therapies. There is, in particular, confusion over terms such as ‘responder status' after treatment for n-AMD, ‘tachyphylaxis' and ‘recalcitrant' n-AMD. This document aims to provide a consensus on definition/categorisation of the response of n-AMD to anti-VEGF therapies and on the time points at which response to treatment should be determined. Primary response is best determined at 1 month following the last initiation dose, while maintained treatment (secondary) response is determined any time after the 4th visit. In a particular eye, secondary responses do not mirror and cannot be predicted from that in the primary phase. Morphological and functional responses to anti-VEGF treatments, do not necessarily correlate, and may be dissociated in an individual eye. Furthermore, there is a ceiling effect that can negate the currently used functional metrics such as >5 letters improvement when the baseline VA is good (ETDRS>70 letters). It is therefore important to use a combination of both the parameters in determining the response.The following are proposed definitions: optimal (good) response is defined as when

  9. Phosphatidylserine (PS) Is Exposed in Choroidal Neovascular Endothelium: PS-Targeting Antibodies Inhibit Choroidal Angiogenesis In Vivo and Ex Vivo

    PubMed Central

    Li, Tao; Aredo, Bogale; Zhang, Kaiyan; Zhong, Xin; Pulido, Jose S.; Wang, Shusheng; He, Yu-Guang; Huang, Xianming; Brekken, Rolf A.; Ufret-Vincenty, Rafael L.

    2015-01-01

    Purpose Choroidal neovascularization (CNV) accounts for 90% of cases of severe vision loss in patients with advanced age-related macular degeneration. Identifying new therapeutic targets for CNV may lead to novel combination therapies to improve outcomes and reduce treatment burden. Our goal was to test whether phosphatidylserine (PS) becomes exposed in the outer membrane of choroidal neovascular endothelium, and whether this could provide a new therapeutic target for CNV. Methods Choroidal neovascularization was induced in C57BL/6J mice using laser photocoagulation. Choroidal neovascularization lesions costained for exposed PS and for intercellular adhesion molecule 2 (or isolectin B4) were imaged in flat mounts and in cross sections. The laser CNV model and a choroidal sprouting assay were used to test the effect of PS-targeting antibodies on choroidal angiogenesis. Choroidal neovascularization lesion size was determined by intercellular adhesion molecule 2 (ICAM-2) staining of flat mounts. Results We found that PS was exposed in CNV lesions and colocalized with vascular endothelial staining. Treatment with PS-targeting antibodies led to a 40% to 80% reduction in CNV lesion area when compared to treatment with a control antibody. The effect was the same as that seen using an equal dose of an anti-VEGF antibody. Results were confirmed using the choroid sprouting assay, an ex vivo model of choroidal angiogenesis. Conclusions We demonstrated that PS is exposed in choroidal neovascular endothelium. Furthermore, targeting this exposed PS with antibodies may be of therapeutic value in CNV. PMID:26529048

  10. Treatment for neovascular age related macular degeneration: The state of the art.

    PubMed

    Eandi, Chiara M; Alovisi, Camilla; De Sanctis, Ugo; Grignolo, Federico M

    2016-09-15

    With the introduction in the clinical practice of drugs inhibiting vascular endothelial growth factor (VEGF) the visual outcomes of patients with neovascular age related macular degeneration (AMD) dramatically improved. Since 2006 repeated intravitreal injections of anti-VEGF became the standard of care for the treatment of neovascular AMD. This review provides an overview of available data form clinical trials supporting the use of anti-VEGF molecules for the treatment of this condition. Several questions remain open, in particular the regimen of treatment, the frequency of injection, the safety of the different drugs, and the poor response to the treatment in some cases. Therefore, new agents and alternative delivery are currently under evaluation. PMID:26948315

  11. Enhanced Ccl2-Ccr2 signaling drives more severe choroidal neovascularization with aging.

    PubMed

    Robbie, Scott J; Georgiadis, Anastasios; Barker, Susie E; Duran, Yanai; Smith, Alexander J; Ali, Robin R; Luhmann, Ulrich F O; Bainbridge, James W

    2016-04-01

    The impact of many inflammatory diseases is influenced by age-related changes in the activation of resident and circulating myeloid cells. In the eye, a major sight-threatening consequence of age-related macular degeneration is the development of severe choroidal neovascularization (CNV). To identify the molecular pathways and myeloid cell populations involved in this increased neovascular response, we characterized the immune status of murine choroid and retina during aging and in the context of experimental CNV. In the choroid, but not in the retina, advancing age is associated with proinflammatory upregulation of CCL2-CCR2 signaling. Genetic excision of CCL2 diminishes age-related inflammatory changes in the choroid, with reduced recruitment of proinflammatory myeloid cells and attenuation of CNV. These findings indicate that CCL2-driven recruitment of myeloid cells contributes to increased severity of CNV with age. Similar mechanisms may be involved in other age-related inflammatory diseases. PMID:26973110

  12. [Clarifying some concepts and clinical significance of refractory or recurrent neovascular age-related macular degeneration].

    PubMed

    Zhao, Jingke; Sun, Xiaodong

    2015-11-01

    Anti-VEGF therapy is currently one of the main treatments for neovascular age-related macular degeneration (nAMD). Clinically, patients under standardized anti-VEGF therapy showed different responses, of which recurrences or even insensitivity were found in some patients. However, the specific definitions of these various clinical responses are still unclarified. Therefore, to consolidate and define these concepts are of great importance regarding to future efficacy comparison, treatment response clarification and novel drug switching therapies. PMID:26850580

  13. Genetic loci that control the size of laser-induced choroidal neovascularization

    PubMed Central

    Nakai, Kei; Rogers, Michael S.; Baba, Takashi; Funakoshi, Taisaku; Birsner, Amy E.; Luyindula, Dema S.; D'Amato, Robert J.

    2009-01-01

    Angiogenesis is controlled by a balance between stimulators and inhibitors. We propose that the balance, as well as the general sensitivity of the endothelium to these factors, varies from individual to individual. Indeed, we have found that individual mouse strains have dramatically different responses to growth factor-induced neovascularization. Quantitative trait loci (QTLs), which influence the extent of corneal angiogenesis induced by vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF2), were previously identified by our laboratory. To investigate the genetic contribution to choroidal neovascularization (CNV), a leading cause of blindness, we have undertaken a similar mapping approach to identify QTLs that influence laser-induced CNV in the BXD series of recombinant inbred mouse strains. Composite interval mapping identified new angiogenic QTLs on chromosomes 2 and 19, in addition to confirming our previous corneal neovascularization QTLs of AngVq1 and AngFq2. The new QTLs are named AngCNVq1 and AngCNVq2. The newly mapped regions contain several candidate genes involved in the angiogenic process, including thrombospondin 1, delta-like 4, BclII modifying factor, phospholipase C, beta 2, adrenergic receptor, beta 1, actin-binding LIM protein 1 and colony stimulating factor 2 receptor, alpha. Differences in these regions may control individual susceptibility to CNV.—Nakai, K., Rogers, M. S., Baba, T., Funakoshi, T., Birsner, A. E., Luyindula, D. S., D’Amato, R. J. Genetic loci that control the size of laser-induced choroidal neovascularization. PMID:19237505

  14. Neovascularization and coronary atherosclerotic plaque: cinematographic localization and quantitative histologic analysis.

    PubMed

    Kamat, B R; Galli, S J; Barger, A C; Lainey, L L; Silverman, K J

    1987-10-01

    A new technique was developed for analyzing the neovascularization associated with coronary artery atherosclerosis: cinematography during silicone polymer injection of the coronary arteries of fixed and cleared human hearts, followed by histologic analysis in routine and 1-micron-thick, Epon-embedded sections. Twenty-two hearts obtained at autopsy were studied. On the basis of cinematographic findings, individual regions of the coronary arteries were classified as negative, positive, or abundantly positive for neovascularization. Positive and abundantly positive areas, which invariably occurred in segments exhibiting changes of atherosclerosis, contained numerous small vessels in the adventitia and outer media (4.7 +/- 1.5 and 9.8 +/- 1.3 [SE] vessel profiles/artery cross-section in positive and abundantly positive areas, versus 1.0 +/- 0.6 in negative regions). Abundantly positive areas, which occurred in coronary artery segments demonstrating the most extensive atherosclerotic change, contained numerous small vessels in the inner media or in the plaque itself. Some of these microvessels were in close proximity to mast cells, which represent potentially rich sources of mediators affecting vascular tone and permeability. Vessels were not observed in the inner media or in atherosclerotic plaque in areas designated either positive or negative by cinematography. These findings show how our approach can be used both to define the three-dimensional, in situ configuration of coronary artery neovascularization and to characterize the histology of this process in detail. They also confirm previous work indicating that areas of coronary arteries involved by atherosclerosis frequently exhibit extensive neovascularization. PMID:2443438

  15. Study of the Effect of Injection Bevacizumab through Various Routes in Neovascular Glaucoma

    PubMed Central

    Agrawal, Kushal U; Tandel, Dipali

    2016-01-01

    ABSTRACT Purpose: To study the effect of injection bevacizumab on iris neovascularization (NVI) and angle neovascularization (NVA) and compare its efficacy in terms of visual outcome, NVI, NVA, and intraocular pressure (IOP) control between intracameral, intravitreal, and combined use. Materials and methods: This was a prospective study conducted at a tertiary center for patients of neovascular glaucoma (NVG), including 20 eyes of 20 patients. After thorough evaluation, patients were divided into three groups: Intracameral, intravitreal, or combined, according to the route of injection bevacizumab required. Results: About 30% of patients belonged to the age group 51 to 60 years of which 80% were female. In 50%, vein occlusion was the cause of NVG, and 50% needed intravitreal injection bevacizumab. After 4th week of injection 90% and after 12th week 60% were found to have absence of NVI. Patients who had IOP in the range of 11 to 20 mm Hg and 21 to 30 mm Hg showed lower IOP as compared to other groups. But no significant difference was noted in higher IOP groups. Only two patients required antiglaucoma surgery. There was no statistically significant difference in visual outcomes in any groups. In all routes, there were statistically significant changes in NVI and NVG in the 1st and 4th weeks. Conclusion: The effect of injection in all routes deteriorates after 8 weeks. Intracameral route of injection is found to be most effective in terms of control of IOP. There was no statistically significant difference in terms of improvement in best corrected visual acuity (BCVA) in any route. Injection bevacizumab is effective and statistically significant in reducing the need of antiglaucoma surgery for NVG patients. How to cite this article: Bhagat PR, Agrawal KU, Tandel D. Study of the Effect of Injection Bevacizumab through Various Routes in Neovascular Glaucoma. J Curr Glaucoma Pract 2016;10(2):39-48. PMID:27536046

  16. Gold nanoparticle enhancement of stereotactic radiosurgery for neovascular age-related macular degeneration

    NASA Astrophysics Data System (ADS)

    Ngwa, Wilfred; Makrigiorgos, G. Mike; Berbeco, Ross I.

    2012-10-01

    Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries for people over the age of 50. In this work, the dosimetric feasibility of using gold nanoparticles (AuNP) as radiosensitizers to enhance kilovoltage stereotactic radiosurgery for neovascular AMD is investigated. Microdosimetry calculations at the sub-cellular level were carried out to estimate the radiation dose enhancement to individual nuclei in neovascular AMD endothelial cells (nDEF) due to photon-induced photo-/Auger electrons from x-ray-irradiated AuNP. The nDEF represents the ratio of radiation doses to the endothelial cell nuclei with and without AuNP. The calculations were carried out for a range of feasible AuNP local concentrations using the clinically applicable 100 kVp x-ray beam parameters employed by a commercially available x-ray therapy system. The results revealed nDEF values of 1.30-3.26 for the investigated concentration range of 1-7 mg g-1, respectively. In comparison, for the same concentration range, nDEF values of 1.32-3.40, 1.31-3.33, 1.29-3.19, 1.28-3.12 were calculated for 80, 90, 110 and 120 kVp x-rays, respectively. Meanwhile, calculations as a function of distance from the AuNP showed that the dose enhancement, for 100 kVp, is markedly confined to the targeted neovascular AMD endothelial cells where AuNP are localized. These findings provide impetus for considering the application of AuNP to enhance therapeutic efficacy during stereotactic radiosurgery for neovascular AMD.

  17. Prevention of Vasa Vasorum Neovascularization Attenuates Early Neointima Formation in Experimental Hypercholesterolemia

    PubMed Central

    Gössl, Mario; Herrmann, Jörg; Tang, Hui; Versari, Daniele; Galili, Offer; Mannheim, Dallit; Rajkumar, S Vincent; Lerman, Lilach O; Lerman, Amir

    2010-01-01

    Objective Vasa vasorum (VV) neovascularization is a key feature of early atherosclerosis and adds substantial endothelial exchange-surface to the coronary vessel wall. Thus, it is conceivable that VV neovascularization favors the entry of pro-inflammatory and pro-atherosclerotic blood components into the coronary vessel wall. We sought to investigate the effects of Thalidomide (Th) a potent anti-angiogenic drug on vasa vasorum (VV) neovascularization, vessel wall inflammation and neointima formation in early experimental atherosclerosis. Methods and Results Female domestic swine, 3-months old, were fed normal (N, n=12) or high-cholesterol diet (HC, n=12) for 3 months. In each group six pigs were randomized to 200 mg Thalidomide daily for the diet period (N+Th, HC+Th). LADs were scanned with micro-CT (20μm cubic voxel size) to determine VV spatial density (#/mm²). Fresh-frozen coronary tissue was used for Western Blotting (VEGF, TNF-α , LOX-1, IkBα and Gro-α ) and electrophoretic mobility shift assay (EMSA, NFkB). Treatment with Thalidomide preserved VV spatial density (2.7±0.3 (N), 6.4±0.7 (HC), 3.5±0.8 (HC+Th); p=ns HC+Th vs. N) and inhibited the expression of VEGF, TNF-alpha and LOX-1 but not NFkB activity in the coronary vessel wall. Immunofluorescense analyses revealed co-localization of vWF but not SMA and NFkB, TNF-α as well as VEGF in HC and HC+Th coronaries. Intima-media thickness was significantly inhibited in HC+Th compared to HC. Serum levels of hs-CRP and TNF-α did not differ among the groups. Conclusions Our study supports a role of VV neovascularization in the development of and a therapeutic potential for anti-angiogenic intervention in early atherosclerosis. PMID:19458984

  18. Successful Treatment of Subretinal Neovascularization with Intravitreal Ranibizumab in a Child with Optic Nerve Head Drusen.

    PubMed

    Gregory-Evans, Kevin; Rai, Poornima; Patterson, Julian

    2009-08-21

    An 11-year-old boy presented with visual acuity reduced to 20/100 in his left eye. Investigations revealed optic disc drusen associated with a minimally classic choroidal neovascular membrane. The patient underwent a 3-month course of intravitreal ranibizumab. Six months of follow-up revealed remarkable visual acuity improvement to 20/20 and complete resolution of exudative maculopathy. PMID:20842978

  19. Octreotide, a Somatostatin Analogue, Fails to Inhibit Hypoxia-induced Retinal Neovascularization in the Neonatal Rat

    PubMed Central

    Averbukh, Edward; Halpert, Michael; Yanko, Ravit; Yanko, Lutza; Peèr, Jacob; Levinger, Samuel; Flyvbjerg, Allan

    2000-01-01

    Objective: Octreotide, a somatostatin analogue, has been shown to prevent angiogenesis in diverse in vitro models. We evaluated its effect on retinal neovascularization in vivo, using a neonatal rat retinopathy model. Methods: We used, on alternating days, hypoxia (10% O2) and hyperoxia (50% O2) during the first 14 days of neonatal rats, to induce retinal neovascularization. Half of the rats were injected subcutaneously with octreotide 0.7 μg/g BW twice daily. At day 18 the eyes were evaluated for the presence of epiretinal and vitreal hemorrhage, neovascularization and epiretinal proliferation. Octreotide pharmacokinetics and its effect on serum growth hormone (GH) and insulin-like growth factor I (IGF-I) were examined in 28 rats. Results: Serum octreotide levels were 667 μg/1 two hours after injection, 26.4 μg/1 after nine hours and 3.2 μg/1 after 14 hours. GH levels were decreased by 40% (p = 0.002) two hours after injection but thereafter returned to baseline. IGF-I levels were unchanged two hours after injection and were elevated by 26% 14 hours after injection (p = 0.02). Epiretinal membranes were highly associated with epiretinal hemorrhages (p < 0.001), while retinal neovascularization was notably associated with vitreal hemorrhages (p < 0.001). Conclusions: Twice-daily injections of octreotide failed to produce sustained decrease in serum GH, but produced rebound elevation of serum IGF-I. Accordingly, no statistically significant effect of injections on retinal pathology was noted. This finding, however, does not contradict our assumption that GH suppression may decrease the severity of retinopathy. PMID:11469389

  20. Mild endoplasmic reticulum stress promotes retinal neovascularization via induction of BiP/GRP78.

    PubMed

    Nakamura, Shinsuke; Takizawa, Haruka; Shimazawa, Masamitsu; Hashimoto, Yuhei; Sugitani, Sou; Tsuruma, Kazuhiro; Hara, Hideaki

    2013-01-01

    Endoplasmic reticulum (ER) stress occurs as a result of accumulation of unfolded or misfolded proteins in the ER and is involved in the mechanisms of various diseases, such as cancer and neurodegeneration. The goal of the present study was to clarify the relationship between ER stress and pathological neovascularization in the retina. Proliferation and migration of human retinal microvascular endothelial cells (HRMEC) were assessed in the presence of ER stress inducers, such as tunicamycin and thapsigargin. The expression of ER chaperone immunoglobulin heavy-chain binding protein (BiP), known as Grp78, was evaluated by real time RT-PCR, immunostaining, and Western blotting. Tunicamycin or thapsigargin was injected into the intravitreal body of oxygen-induced retinopathy (OIR) model mice at postnatal day 14 (P14) and retinal neovascularization was quantified at P17. The expression and localization of BiP in the retina was also evaluated in the OIR model. Exposure to tunicamycin and thapsigargin increased the proliferation and migration of HRMEC. Tunicamycin enhanced the expression of BiP in HRMEC at both the mRNA level and at the protein level on the cell surface, and increased the formation of a BiP/T-cadherin immunocomplex. In OIR model mice, retinal neovascularization was accelerated by treatments with ER stress inducers. BiP was particularly observed in the pathological vasculature and retinal microvascular endothelial cells, and the increase of BiP expression was correlated with retinal neovascularization. In conclusion, ER stress may contribute to the formation of abnormal vasculature in the retina via BiP complexation with T-cadherin, which then promotes endothelial cell proliferation and migration. PMID:23544152

  1. Genetic loci that control the size of laser-induced choroidal neovascularization.

    PubMed

    Nakai, Kei; Rogers, Michael S; Baba, Takashi; Funakoshi, Taisaku; Birsner, Amy E; Luyindula, Dema S; D'Amato, Robert J

    2009-07-01

    Angiogenesis is controlled by a balance between stimulators and inhibitors. We propose that the balance, as well as the general sensitivity of the endothelium to these factors, varies from individual to individual. Indeed, we have found that individual mouse strains have dramatically different responses to growth factor-induced neovascularization. Quantitative trait loci (QTLs), which influence the extent of corneal angiogenesis induced by vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF2), were previously identified by our laboratory. To investigate the genetic contribution to choroidal neovascularization (CNV), a leading cause of blindness, we have undertaken a similar mapping approach to identify QTLs that influence laser-induced CNV in the BXD series of recombinant inbred mouse strains. Composite interval mapping identified new angiogenic QTLs on chromosomes 2 and 19, in addition to confirming our previous corneal neovascularization QTLs of AngVq1 and AngFq2. The new QTLs are named AngCNVq1 and AngCNVq2. The newly mapped regions contain several candidate genes involved in the angiogenic process, including thrombospondin 1, delta-like 4, BclII modifying factor, phospholipase C, beta 2, adrenergic receptor, beta 1, actin-binding LIM protein 1 and colony stimulating factor 2 receptor, alpha. Differences in these regions may control individual susceptibility to CNV. PMID:19237505

  2. The Application of OCTA in Assessment of Anti-VEGF Therapy for Idiopathic Choroidal Neovascularization

    PubMed Central

    Sun, Zihan; Dai, Hong

    2016-01-01

    Purpose. To assess the morphology of idiopathic choroidal neovascularization (ICNV) by optical coherence tomography angiography (OCTA) and determine the therapeutic effects of intravitreal antivascular endothelial growth factor (anti-VEGF). Method. Patients with naive ICNV were assessed by spectral domain optical coherence tomography (SD-OCT) and OCTA in this observational study. The timing of observation was before treatment, 1 day after treatment with intravitreal anti-VEGF injection, and 1 month after the treatment. The central retina thickness (CRT) on SD-OCT, selected CNV area, and flow area on OCTA were measured. Results. A total of 17 eyes from 17 patients with ICNV were included in this study. OCTA showed visible irregular choroidal neovascularization with “tree-in-bud” form on outer retinal layer. After treatment, as well as in the 1-day follow-up, CNV decreased in size from the periphery, and the vessel density was reduced. As shown on OCTA, the selected CNV area and flow area were significantly reduced compared to pretreatment. The rate of CNV vessel area changes was higher on OCTA than the changes in CRT on SD-OCT at 1-day and 1-month follow-up. Conclusion. Intravitreal injection of anti-VEGF is effective for idiopathic choroidal neovascularization, and the treatment outcomes are observable after 1 day. OCTA provides a useful approach for monitoring and evaluating the treatment of intravitreal anti-VEGF for CNV. PMID:27471600

  3. The COX-2-Selective Antagonist (NS-398) Inhibits Choroidal Neovascularization and Subretinal Fibrosis

    PubMed Central

    Zhang, Ruoshuang; Liu, Zheli; Zhang, Han; Zhang, Yi; Lin, Dong

    2016-01-01

    Choroidal neovascularization (CNV) is an important pathologic component of neovascular age-related macular degeneration (AMD), and CNV lesions later develop into fibrous scars, which contribute to the loss of central vision. Nowadays, the precise molecular and cellular mechanisms underlying CNV and subretinal fibrosis have yet to be fully elucidated. Cyclooxygenase-2 (COX-2) has previously been implicated in angiogenesis and fibrosis. However, the role of COX-2 in the pathogenesis of CNV and subretinal fibrosis is poorly understood. The present study reveals several important findings concerning the relationship of COX-2 signaling with CNV and subretinal fibrosis. Experimental CNV lesions were attenuated by the administration of NS-398, a COX-2-selective antagonist. NS-398-induced CNV suppression was found to be mediated by the attenuation of macrophage infiltration and down-regulation of VEGF in the retinal pigment epithelium–choroid complex. Additionally, NS-398 attenuated subretinal fibrosis, in an experimental model of subretinal scarring observed in neovascular AMD, by down-regulation of TGF-β2 in the retinal pigment epithelium–choroid complex. Moreover, we cultured mouse RPE cells and found that NS-398 decreased the secretion of VEGF and TGF-β2 in mouse RPE cells. The results of the present study provide new findings regarding the molecular basis of CNV and subretinal fibrosis, and provide a proof-of-concept approach for the efficacy of COX-2 inhibition in treating subretinal fibrosis. PMID:26760305

  4. Intrastromal Injection of Bevacizumab in the Management of Corneal Neovascularization: About 25 Eyes

    PubMed Central

    Ibtissam, Hajji; Mohammed, Baali; Hasna, Soummane; Abdeljalil, Moutaouakil

    2016-01-01

    Introduction. Corneal neovessels are a major risk factor for corneal graft rejection, due to the loss of the immune privilege. The purpose of this study is to evaluate the effectiveness of intrastromal injection of bevacizumab in the treatment of corneal neovascularization. Material and Methods. This is a prospective study that included 25 eyes of 22 patients with deep corneal neovessels, treated with intrastromal injections of bevacizumab. Results. The average age of patients was 31 years ranging from 16 to 44 years. The causes of neovascularization were dominated by herpetic keratitis (10 cases). The evolution was marked by complete regress of neovessels in 16 patients, partial regress in 6 cases, and reduced opacity and improved visual acuity in 5 patients. No side effects were noted. Discussion. Short-term results demonstrated the effectiveness of intrastromal injection of bevacizumab in the treatment of corneal neovessels. It may be an option or a complement to other useful treatments in stabilizing or improving vision. Conclusion. Bevacizumab is an effective additional treatment for the improvement of corneal transplants prognosis with preoperative corneal neovascularization. PMID:27610242

  5. Optical Coherence Tomography Angiography of Type 2 Neovascularization in Age-Related Macular Degeneration.

    PubMed

    Souied, Eric H; El Ameen, Ala; Semoun, Oudy; Miere, Alexandra; Querques, Giuseppe; Cohen, Salomon Yves

    2016-01-01

    Well-defined choroidal neovascularization, known as type 2 neovascularization (NV) or classic NV, is the least representative phenotype of exudative age-related macular degeneration. Clinical aspects of type 2 NV have been widely described in the literature, and to date fluorescein angiography remains the gold standard for imaging age-related macular degeneration at initial presentation. Optical coherence tomography angiography (OCT-A) can be used to image vessels based on flow characteristics without any dye injection. Type 2 NV can be visualized using OCT-A with very typical patterns. A neovascular membrane appears as either a medusa-shaped complex or a glomerulus-shaped lesion in the outer retina and the choriocapillaris layer. Furthermore, in the choriocapillaris layer, the external borders of the lesion appear as a dark ring in most cases, and one or more central feeder vessels that extend deeply into the more profound choroidal layers are visible. Identification of type 2 NV is easily feasible for any clinician using OCT-A, especially in areas where there are normally no vessels, like in subretinal space, if the interpretation rules are respected. PMID:27023798

  6. Predictors of visual and anatomical outcomes for neovascular age-related macular degeneration treated with bevacizumab

    PubMed Central

    MA, CHAORAN; BAI, LIANG; LEI, CHUNLING; WU, CHANGRUI; SHI, QIANG; HU, FENG; HAO, ZHENXUAN; MA, LE

    2015-01-01

    The present study aimed to evaluate the predictive factors for visual and anatomical outcomes in neovascular age-related macular degeneration (AMD) patients treated with intravitreal bevacizumab (IVB). A total of 113 patients with neovascular AMD received IVB treatment. The best corrected visual acuity (BCVA), central retinal thickness (CRT) and total macular volume (TMV) were assessed before the injection, and at 1, 2, 3 and 9 months after surgery. Changes in BCVA and these optical coherence tomography (OCT) outcomes from baseline were compared, and independent predictors were evaluated by logistic regression models. During the treatment, logarithm of the minimum angle of resolution (logMAR) significantly decreased from 1.12 to 0.83, and reductions in OCT parameters were earlier and larger. Baseline BCVA was associated with the changes in BCVA and CRT, whereas baseline OCT features significantly affected their own changes. Larger baseline logMAR and OCT features were more likely to experience a greater proportion of ≥50 µm reduction in CRT (P<0.05). The BCVA decreases were positively associated with the reductions in CRT (r=0.34, P<0.01) and TMV (r=0.41, P<0.01). Among patients with neovascular AMD, IVB resulted in earlier significant decreases in TMV and CRT, suggesting that these OCT anatomical outcomes may be considered as more sensitive responders to evaluate the treatment effects of bevacizumab. PMID:26171156

  7. Copper Transport Protein Antioxidant-1 Promotes Inflammatory Neovascularization via Chaperone and Transcription Factor Function

    PubMed Central

    Chen, Gin-Fu; Sudhahar, Varadarajan; Youn, Seock-Won; Das, Archita; Cho, Jaehyung; Kamiya, Tetsuro; Urao, Norifumi; McKinney, Ronald D.; Surenkhuu, Bayasgalan; Hamakubo, Takao; Iwanari, Hiroko; Li, Senlin; Christman, John W.; Shantikumar, Saran; Angelini, Gianni D.; Emanueli, Costanza; Ushio-Fukai, Masuko; Fukai, Tohru

    2015-01-01

    Copper (Cu), an essential micronutrient, plays a fundamental role in inflammation and angiogenesis; however, its precise mechanism remains undefined. Here we uncover a novel role of Cu transport protein Antioxidant-1 (Atox1), which is originally appreciated as a Cu chaperone and recently discovered as a Cu-dependent transcription factor, in inflammatory neovascularization. Atox1 expression is upregulated in patients and mice with critical limb ischemia. Atox1-deficient mice show impaired limb perfusion recovery with reduced arteriogenesis, angiogenesis, and recruitment of inflammatory cells. In vivo intravital microscopy, bone marrow reconstitution, and Atox1 gene transfer in Atox1−/− mice show that Atox1 in endothelial cells (ECs) is essential for neovascularization and recruitment of inflammatory cells which release VEGF and TNFα. Mechanistically, Atox1-depleted ECs demonstrate that Cu chaperone function of Atox1 mediated through Cu transporter ATP7A is required for VEGF-induced angiogenesis via activation of Cu enzyme lysyl oxidase. Moreover, Atox1 functions as a Cu-dependent transcription factor for NADPH oxidase organizer p47phox, thereby increasing ROS-NFκB-VCAM-1/ICAM-1 expression and monocyte adhesion in ECs inflamed with TNFα in an ATP7A-independent manner. These findings demonstrate a novel linkage between Atox1 and NADPH oxidase involved in inflammatory neovascularization and suggest Atox1 as a potential therapeutic target for treatment of ischemic disease. PMID:26437801

  8. The Application of OCTA in Assessment of Anti-VEGF Therapy for Idiopathic Choroidal Neovascularization.

    PubMed

    Chen, Qin; Yu, Xiaobing; Sun, Zihan; Dai, Hong

    2016-01-01

    Purpose. To assess the morphology of idiopathic choroidal neovascularization (ICNV) by optical coherence tomography angiography (OCTA) and determine the therapeutic effects of intravitreal antivascular endothelial growth factor (anti-VEGF). Method. Patients with naive ICNV were assessed by spectral domain optical coherence tomography (SD-OCT) and OCTA in this observational study. The timing of observation was before treatment, 1 day after treatment with intravitreal anti-VEGF injection, and 1 month after the treatment. The central retina thickness (CRT) on SD-OCT, selected CNV area, and flow area on OCTA were measured. Results. A total of 17 eyes from 17 patients with ICNV were included in this study. OCTA showed visible irregular choroidal neovascularization with "tree-in-bud" form on outer retinal layer. After treatment, as well as in the 1-day follow-up, CNV decreased in size from the periphery, and the vessel density was reduced. As shown on OCTA, the selected CNV area and flow area were significantly reduced compared to pretreatment. The rate of CNV vessel area changes was higher on OCTA than the changes in CRT on SD-OCT at 1-day and 1-month follow-up. Conclusion. Intravitreal injection of anti-VEGF is effective for idiopathic choroidal neovascularization, and the treatment outcomes are observable after 1 day. OCTA provides a useful approach for monitoring and evaluating the treatment of intravitreal anti-VEGF for CNV. PMID:27471600

  9. Copper Transport Protein Antioxidant-1 Promotes Inflammatory Neovascularization via Chaperone and Transcription Factor Function.

    PubMed

    Chen, Gin-Fu; Sudhahar, Varadarajan; Youn, Seock-Won; Das, Archita; Cho, Jaehyung; Kamiya, Tetsuro; Urao, Norifumi; McKinney, Ronald D; Surenkhuu, Bayasgalan; Hamakubo, Takao; Iwanari, Hiroko; Li, Senlin; Christman, John W; Shantikumar, Saran; Angelini, Gianni D; Emanueli, Costanza; Ushio-Fukai, Masuko; Fukai, Tohru

    2015-01-01

    Copper (Cu), an essential micronutrient, plays a fundamental role in inflammation and angiogenesis; however, its precise mechanism remains undefined. Here we uncover a novel role of Cu transport protein Antioxidant-1 (Atox1), which is originally appreciated as a Cu chaperone and recently discovered as a Cu-dependent transcription factor, in inflammatory neovascularization. Atox1 expression is upregulated in patients and mice with critical limb ischemia. Atox1-deficient mice show impaired limb perfusion recovery with reduced arteriogenesis, angiogenesis, and recruitment of inflammatory cells. In vivo intravital microscopy, bone marrow reconstitution, and Atox1 gene transfer in Atox1(-/-) mice show that Atox1 in endothelial cells (ECs) is essential for neovascularization and recruitment of inflammatory cells which release VEGF and TNFα. Mechanistically, Atox1-depleted ECs demonstrate that Cu chaperone function of Atox1 mediated through Cu transporter ATP7A is required for VEGF-induced angiogenesis via activation of Cu enzyme lysyl oxidase. Moreover, Atox1 functions as a Cu-dependent transcription factor for NADPH oxidase organizer p47phox, thereby increasing ROS-NFκB-VCAM-1/ICAM-1 expression and monocyte adhesion in ECs inflamed with TNFα in an ATP7A-independent manner. These findings demonstrate a novel linkage between Atox1 and NADPH oxidase involved in inflammatory neovascularization and suggest Atox1 as a potential therapeutic target for treatment of ischemic disease. PMID:26437801

  10. Therapeutic Effects of Topical Netrin-4 Inhibits Corneal Neovascularization in Alkali-Burn Rats

    PubMed Central

    Han, Yun; Shao, Yi; Liu, Tingting; Qu, Yang-Luowa; Li, Wei; Liu, Zuguo

    2015-01-01

    Netrins are secreted molecules involved in axon guidance and angiogenesis. However, the role of netrins in the vasculature remains unclear. Netrin-4 and netrin-1 have been found to be either pro- or antiangiogenic factors. Previously, we found that netrin-1 acts as an anti-angiogenic factor in rats by inhibiting alkali burn-induced corneal neovascularization. Here, we further investigate the effects of netrin-4, another member of the same netrin family, on neovascularization in vitro and in vivo. We found that netrin-4 functions similarly as netrin-1 in angiogenesis. In vitro angiogenesis assay shows that netrin-4 affected human umbilical vein endothelial cell (HUVEC) tube formation, viability and proliferation, apoptosis, migration, and invasion in a dose-dependent manner. Netrin-4 was topically applied in vivo to alkali-burned rat corneas on day 0 (immediately after injury) and/or day 10 post-injury. Netrin-4 subsequently suppressed and reversed corneal neovascularization. Netrin-4 inhibited corneal epithelial and stromal cell apoptosis, inhibited vascular endothelial growth factor (VEGF), but promoted pigment epithelium-derived factor (PEDF) expression, decreased NK-KB p65 expression, and inhibits neutrophil and macrophage infiltration. These results indicate that netrin-4 shed new light on its potential roles in treatmenting for angiogenic diseases that affect the ocular surface, as well as other tissues. PMID:25853509

  11. CD200R signaling inhibits pro-angiogenic gene expression by macrophages and suppresses choroidal neovascularization

    PubMed Central

    Horie, Shintaro; Robbie, Scott J.; Liu, Jian; Wu, Wei-Kang; Ali, Robin R.; Bainbridge, James W.; Nicholson, Lindsay B.; Mochizuki, Manabu; Dick, Andrew D.; Copland, David A.

    2013-01-01

    Macrophages are rapidly conditioned by cognate and soluble signals to acquire phenotypes that deliver specific functions during inflammation, wound healing and angiogenesis. Whether inhibitory CD200R signaling regulates pro-angiogenic macrophage phenotypes with the potential to suppress ocular neovascularization is unknown. CD200R-deficient bone marrow derived macrophages (BMMΦ) were used to demonstrate that macrophages lacking this inhibitory receptor exhibit enhanced levels of Vegfa, Arg-1 and Il-1β when stimulated with PGE2 or RPE-conditioned (PGE2-enriched) media. Endothelial tube formation in HUVECs was increased when co-cultured with PGE2-conditioned CD200R−/− BMMΦ, and laser-induced choroidal neovascularization was enhanced in CD200R-deficient mice. In corroboration, signaling through CD200R results in the down-regulation of BMMΦ angiogenic and pro-inflammatory phenotypes. Translational potential of this pathway was investigated in the laser-induced model of choroidal neovascularization. Local delivery of a CD200R agonist mAb to target myeloid infiltrate alters macrophage phenotype and inhibits pro-angiogenic gene expression, which suppresses pathological angiogenesis and CNV development. PMID:24170042

  12. Intrastromal Injection of Bevacizumab in the Management of Corneal Neovascularization: About 25 Eyes.

    PubMed

    Sarah, Belghmaidi; Ibtissam, Hajji; Mohammed, Baali; Hasna, Soummane; Abdeljalil, Moutaouakil

    2016-01-01

    Introduction. Corneal neovessels are a major risk factor for corneal graft rejection, due to the loss of the immune privilege. The purpose of this study is to evaluate the effectiveness of intrastromal injection of bevacizumab in the treatment of corneal neovascularization. Material and Methods. This is a prospective study that included 25 eyes of 22 patients with deep corneal neovessels, treated with intrastromal injections of bevacizumab. Results. The average age of patients was 31 years ranging from 16 to 44 years. The causes of neovascularization were dominated by herpetic keratitis (10 cases). The evolution was marked by complete regress of neovessels in 16 patients, partial regress in 6 cases, and reduced opacity and improved visual acuity in 5 patients. No side effects were noted. Discussion. Short-term results demonstrated the effectiveness of intrastromal injection of bevacizumab in the treatment of corneal neovessels. It may be an option or a complement to other useful treatments in stabilizing or improving vision. Conclusion. Bevacizumab is an effective additional treatment for the improvement of corneal transplants prognosis with preoperative corneal neovascularization. PMID:27610242

  13. Occludin S490 Phosphorylation Regulates Vascular Endothelial Growth Factor-Induced Retinal Neovascularization.

    PubMed

    Liu, Xuwen; Dreffs, Alyssa; Díaz-Coránguez, Monica; Runkle, E Aaron; Gardner, Thomas W; Chiodo, Vince A; Hauswirth, William W; Antonetti, David A

    2016-09-01

    Occludin is a transmembrane tight junction protein that contributes to diverse cellular functions, including control of barrier properties, cell migration, and proliferation. Vascular endothelial growth factor (VEGF) induces phosphorylation of occludin at S490, which is required for VEGF-induced endothelial permeability. Herein, we demonstrate that occludin S490 phosphorylation also regulates VEGF-induced retinal endothelial cell proliferation and neovascularization. Using a specific antibody, phospho-occludin was located in centrosomes in endothelial cell cultures, animal models, and human surgical samples of retinal neovessels. Occludin S490 phosphorylation was found to increase with endothelial tube formation in vitro and in vivo during retinal neovascularization after induction of VEGF expression. More important, expression of occludin mutated at S490 to Ala, completely inhibited angiogenesis in cell culture models and in vivo. Collectively, these data suggest a novel role for occludin in regulation of endothelial proliferation and angiogenesis in a phosphorylation-dependent manner. These findings may lead to methods of regulating pathological neovascularization by specifically targeting endothelial cell proliferation. PMID:27423695

  14. STAT3 activation in circulating monocytes contributes to neovascular age-related macular degeneration

    PubMed Central

    Chen, Mei; Lechner, Judith; Zhao, Jiawu; Toth, Levente; Hogg, Ruth; Silvestri, Giuliana; Kissenpfennig, Adrien; Chakravarthy, Usha; Xu, Heping

    2016-01-01

    Infiltrating macrophages are critically involved in pathogenic angiogenesis such as neovascular age-related macular degeneration (nAMD). Macrophages originate from circulating monocytes and three subtypes of monocyte exist in humans: classical (CD14+CD16-), non-classical (CD14-CD16+) and intermediate (CD14+CD16+) monocytes. The aim of this study was to investigate the role of circulating monocyte in neovascular age-related macular degeneration (nAMD). Flow cytometry analysis showed that the intermediate monocytes from nAMD patients expressed higher levels of CX3CR1 and HLA-DR compared to those from controls. Monocytes from nAMD patients expressed higher levels of phosphorylated Signal Transducer and Activator of Transcription 3 (pSTAT3), and produced higher amount of VEGF. In the mouse model of choroidal neovascularization (CNV), pSTAT3 expression was increased in the retina and RPE/choroid, and 49.24% of infiltrating macrophages express pSTAT3. Genetic deletion of the Suppressor of Cytokine Signalling 3 (SOCS3) in myeloid cells in the LysM-Cre+/-:SOCS3fl/fl mice resulted in spontaneous STAT3 activation and accelerated CNV formation. Inhibition of STAT3 activation using a small peptide LLL12 suppressed laser-induced CNV. Our results suggest that monocytes, in particular the intermediate subset of monocytes are activated in nAMD patients. STAT3 activation in circulating monocytes may contribute to the development of choroidal neovascularisation in AMD. PMID:27009107

  15. Suppression of T cell-induced osteoclast formation

    SciTech Connect

    Karieb, Sahar; Fox, Simon W.

    2013-07-12

    Highlights: •Genistein and coumestrol prevent activated T cell induced osteoclast formation. •Anti-TNF neutralising antibodies prevent the pro-osteoclastic effect of activated T cells. •Phytoestrogens inhibit T cell derived TNF alpha and inflammatory cytokine production. •Phytoestrogens have a broader range of anti-osteoclastic actions than other anti-resorptives. -- Abstract: Inhibition of T cell derived cytokine production could help suppress osteoclast differentiation in inflammatory skeletal disorders. Bisphosphonates are typically prescribed to prevent inflammatory bone loss but are not tolerated by all patients and are associated with an increased risk of osteonecrosis of the jaw. In light of this other anti-resorptives such as phytoestrogens are being considered. However the effect of phytoestrogens on T cell-induced osteoclast formation is unclear. The effect of genistein and coumestrol on activated T cell-induced osteoclastogenesis and cytokine production was therefore examined. Concentrations of genistein and coumestrol (10{sup −7} M) previously shown to directly inhibit osteoclast formation also suppressed the formation of TRAP positive osteoclast induced by con A activated T cells, which was dependent on inhibition of T cell derived TNF-α. While both reduced osteoclast formation their mechanism of action differed. The anti-osteoclastic effect of coumestrol was associated with a dual effect on con A induced T cell proliferation and activation; 10{sup −7} M coumestrol significantly reducing T cell number (0.36) and TNF-α (0.47), IL-1β (0.23) and IL-6 (0.35) expression, whereas genistein (10{sup −7} M) had no effect on T cell number but a more pronounced effect on T cell differentiation reducing expression of TNF-α (0.49), IL-1β (0.52), IL-6 (0.71) and RANKL (0.71). Phytoestrogens therefore prevent the pro-osteoclastic action of T cells suggesting they may have a role in the control of inflammatory bone loss.

  16. ENDOTHELIAL PROGENITOR CELL ADHESION, GROWTH AND CHARACTERIZATION ON TRABECULAR TITANIUM AND TRABECULAR TITANIUM COATED WITH COLLAGEN OR DECELLULARIZED ECM.

    PubMed

    Gastaldi, G; Caliogna, L; Botta, L; Ghiara, M; Benazzo, F

    2015-01-01

    Adequate blood supply is essential for prosthesis osteointegration and bone healing as it supplies oxygen, nutrition and progenitor cells. The bone healing process and vascularization depend upon the endothelial cells, which speed up implant osteointegration. Endothelial Progenitor Cells (EPC) are a population of stem cells that can reproduce, migrate and acquire mature endothelial phenotype. Their recruitment occurs in the tissue lesion to enhance neovascularization. Trabecular TitaniumTM (TTTM) is a new biomaterial with very interesting biomechanical characteristics and fast osteointegration. This study has investigated adhesion, proliferation and characteristics of EPC on three types of biomaterial: unmodified trabecular titanium, trabecular titanium coated with the ECM deposited by human mesenchymal stem cells isolated from subcutaneous adipose tissue and decellularized and trabecular titanium coated with type I collagen (control scaffold). MTT assay showed similar percentages of EPCs seeded on the different kinds of scaffold: 67% on TT, 70% on decellularized scaffolds and 82% on collagen-coated scaffolds. There were no statistically significant differences between the three groups. We therefore conclude that TTTM allows EPC adhesion and proliferation and, consequently, by permitting vascularization, it favours prosthesis osteointegration. PMID:26652487

  17. Myocardial regeneration by transplantation of modified endothelial progenitor cells expressing SDF-1 in a rat model

    PubMed Central

    Schuh, Alexander; Kroh, Andreas; Konschalla, Simone; Liehn, Elisa A; Sobota, Radoslav M; Biessen, Erik AL; Bot, Ilze; Sönmez, Tolga Taha; Schober, Andreas; Marx, Nikolaus; Weber, Christian; Sasse, Alexander

    2012-01-01

    Cell based therapy has been shown to attenuate myocardial dysfunction after myocardial infarction (MI) in different acute and chronic animal models. It has been further shown that stromal-cell derived factor-1α (SDF-1α) facilitates proliferation and migration of endogenous progenitor cells into injured tissue. The aim of the present study was to investigate the role of exogenously applied and endogenously mobilized cells in a regenerative strategy for MI therapy. Lentivirally SDF-1α-infected endothelial progenitor cells (EPCs) were injected after 90 min. of ligation and reperfusion of the left anterior descending artery (LAD) intramyocardial and intracoronary using a new rodent catheter system. Eight weeks after transplantation, echocardiography and isolated heart studies revealed a significant improvement of LV function after intramyocardial application of lentiviral with SDF-1 infected EPCs compared to medium control. Intracoronary application of cells did not lead to significant differences compared to medium injected control hearts. Histology showed a significantly elevated rate of apoptotic cells and augmented proliferation after transplantation of EPCs and EPCs + SDF-1α in infarcted myocardium. In addition, a significant increased density of CD31+ vessel structures, a lower collagen content and higher numbers of inflammatory cells after transplantation of SDF-1 transgenic cells were detectable. Intramyocardial application of lentiviral-infected EPCs is associated with a significant improvement of myocardial function after infarction, in contrast to an intracoronary application. Histological results revealed a significant augmentation of neovascularization, lower collagen content, higher numbers of inflammatory cells and remarkable alterations of apoptotic/proliferative processes in infarcted areas after cell transplantation. PMID:22288686

  18. Safety and Tolerability Study of AAV2-sFLT01 in Patients With Neovascular Age-Related Macular Degeneration (AMD)

    ClinicalTrials.gov

    2016-01-05

    Macular Degeneration; Age-Related Maculopathies; Age-Related Maculopathy; Maculopathies, Age-Related; Maculopathy, Age-Related; Retinal Degeneration; Retinal Neovascularization; Gene Therapy; Therapy, Gene; Eye Diseases

  19. Quantitative optical coherence tomography angiography of choroidal neovascularization in age-related macular degeneration

    PubMed Central

    Jia, Yali; Bailey, Steven T.; Wilson, David J.; Tan, Ou; Klein, Michael L.; Flaxel, Christina J.; Potsaid, Benjamin; Liu, Jonathan J.; Lu, Chen D.; Kraus, Martin F.; Fujimoto, James G.; Huang, David

    2014-01-01

    Purpose To detect and quantify choroidal neovascularization (CNV) in age-related macular degeneration (AMD) patients using optical coherence tomography (OCT) angiography. Design Observational, cross-sectional study. Participants Five normal subjects and five neovascular AMD patients were included. Methods Five eyes with neovascular AMD and five normal age-matched controls were scanned by a high-speed (100,000 A-scans/sec) 1050 nm wavelength swept-source OCT. The macular angiography scan covered a 3×3 mm area and comprised 200×200×8 A-scans acquired in 3.5 sec. Flow was detected using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. Motion artifacts were removed by three dimensional (3D) orthogonal registration and merging of 4 scans. The 3D angiography was segmented into 3 layers: inner retina (to show retinal vasculature), outer retina (to identify CNV), and choroid. En face maximum projection was used to obtain 2D angiograms from the 3 layers. CNV area and flow index were computed from the en face OCT angiogram of the outer retinal layer. Flow (decorrelation) and structural data were combined in composite color angiograms for both en face and cross-sectional views. Main Outcome Measurements CNV angiogram, CNV area, and CNV flow index. Results En face OCT angiograms of CNVs showed sizes and locations that were confirmed by fluorescein angiography. OCT angiography provided more distinct vascular network patterns that were less obscured by subretinal hemorrhage. The en face angiograms also showed areas of reduced choroidal flow adjacent to the CNV in all cases and significantly reduced retinal flow in one case. Cross-sectional angiograms were used to visualize CNV location relative to the retinal pigment epithelium and Bruch’s layer and classify type I and type II CNV. A feeder vessel could be identified in one case. Higher flow indexes were associated with larger CNV and type II CNV. Conclusions OCT angiography provides depth

  20. Stem Cells and Progenitor Cells for Tissue-Engineered Solutions to Congenital Heart Defects

    PubMed Central

    Gao, Yang; Jacot, Jeffrey G

    2015-01-01

    Synthetic patches and fixed grafts currently used in the repair of congenital heart defects are nonliving, noncontractile, and not electrically responsive, leading to increased risk of complication, reoperation, and sudden cardiac death. Studies suggest that tissue-engineered patches made from living, functional cells could grow with the patient, facilitate healing, and help recover cardiac function. In this paper, we review the research into possible sources of cardiomyocytes and other cardiac cells, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells, adipose-derived stem cells, umbilical cord blood cells, amniotic fluid-derived stem cells, and cardiac progenitor cells. Each cell source has advantages, but also has technical hurdles to overcome, including heterogeneity, functional maturity, immunogenicity, and pathogenicity. Additionally, biomaterials used as patch materials will need to attract and support desired cells and induce minimal immune responses. PMID:26379417

  1. Neural Progenitors Adopt Specific Identities by Directly Repressing All Alternative Progenitor Transcriptional Programs

    PubMed Central

    Kutejova, Eva; Sasai, Noriaki; Shah, Ankita; Gouti, Mina; Briscoe, James

    2016-01-01

    Summary In the vertebrate neural tube, a morphogen-induced transcriptional network produces multiple molecularly distinct progenitor domains, each generating different neuronal subtypes. Using an in vitro differentiation system, we defined gene expression signatures of distinct progenitor populations and identified direct gene-regulatory inputs corresponding to locations of specific transcription factor binding. Combined with targeted perturbations of the network, this revealed a mechanism in which a progenitor identity is installed by active repression of the entire transcriptional programs of other neural progenitor fates. In the ventral neural tube, sonic hedgehog (Shh) signaling, together with broadly expressed transcriptional activators, concurrently activates the gene expression programs of several domains. The specific outcome is selected by repressive input provided by Shh-induced transcription factors that act as the key nodes in the network, enabling progenitors to adopt a single definitive identity from several initially permitted options. Together, the data suggest design principles relevant to many developing tissues. PMID:26972603

  2. Neural Progenitors Adopt Specific Identities by Directly Repressing All Alternative Progenitor Transcriptional Programs.

    PubMed

    Kutejova, Eva; Sasai, Noriaki; Shah, Ankita; Gouti, Mina; Briscoe, James

    2016-03-21

    In the vertebrate neural tube, a morphogen-induced transcriptional network produces multiple molecularly distinct progenitor domains, each generating different neuronal subtypes. Using an in vitro differentiation system, we defined gene expression signatures of distinct progenitor populations and identified direct gene-regulatory inputs corresponding to locations of specific transcription factor binding. Combined with targeted perturbations of the network, this revealed a mechanism in which a progenitor identity is installed by active repression of the entire transcriptional programs of other neural progenitor fates. In the ventral neural tube, sonic hedgehog (Shh) signaling, together with broadly expressed transcriptional activators, concurrently activates the gene expression programs of several domains. The specific outcome is selected by repressive input provided by Shh-induced transcription factors that act as the key nodes in the network, enabling progenitors to adopt a single definitive identity from several initially permitted options. Together, the data suggest design principles relevant to many developing tissues. PMID:26972603

  3. Butein Inhibits Angiogenesis of Human Endothelial Progenitor Cells via the Translation Dependent Signaling Pathway

    PubMed Central

    Chung, Ching-Hu; Chang, Chien-Hsin; Chen, Shiou-Sheng; Wang, Hsueh-Hsiao; Yen, Juei-Yu; Hsiao, Che-Jen; Wu, Nan-Lin; Chen, Yen-Ling; Huang, Tur-Fu; Wang, Po-Chuan; Yeh, Hung-I; Wang, Shih-Wei

    2013-01-01

    Compelling evidence indicates that bone marrow-derived endothelial progenitor cells (EPCs) can contribute to postnatal neovascularization and tumor angiogenesis. EPCs have been shown to play a “catalytic” role in metastatic progression by mediating the angiogenic switch. Understanding the pharmacological functions and molecular targets of natural products is critical for drug development. Butein, a natural chalcone derivative, has been reported to exert potent anticancer activity. However, the antiangiogenic activity of butein has not been addressed. In this study, we found that butein inhibited serum- and vascular endothelial growth factor- (VEGF-) induced cell proliferation, migration, and tube formation of human EPCs in a concentration dependent manner without cytotoxic effect. Furthermore, butein markedly abrogated VEGF-induced vessels sprouting from aortic rings and suppressed microvessel formation in the Matrigel implant assay in vivo. In addition, butein concentration-dependently repressed the phosphorylation of Akt, mTOR, and the major downstream effectors, p70S6K, 4E-BP1, and eIF4E in EPCs. Taken together, our results demonstrate for the first time that butein exhibits the antiangiogenic effect both in vitro and in vivo by targeting the translational machinery. Butein is a promising angiogenesis inhibitor with the potential for treatment of cancer and other angiogenesis-related diseases. PMID:23840271

  4. A dynamic epicardial injury response supports progenitor cell activity during zebrafish heart regeneration.

    PubMed

    Lepilina, Alexandra; Coon, Ashley N; Kikuchi, Kazu; Holdway, Jennifer E; Roberts, Richard W; Burns, C Geoffrey; Poss, Kenneth D

    2006-11-01

    Zebrafish possess a unique yet poorly understood capacity for cardiac regeneration. Here, we show that regeneration proceeds through two coordinated stages following resection of the ventricular apex. First a blastema is formed, comprised of progenitor cells that express precardiac markers, undergo differentiation, and proliferate. Second, epicardial tissue surrounding both cardiac chambers induces developmental markers and rapidly expands, creating a new epithelial cover for the exposed myocardium. A subpopulation of these epicardial cells undergoes epithelial-to-mesenchymal transition (EMT), invades the wound, and provides new vasculature to regenerating muscle. During regeneration, the ligand fgf17b is induced in myocardium, while receptors fgfr2 and fgfr4 are induced in adjacent epicardial-derived cells. When fibroblast growth factors (Fgf) signaling is experimentally blocked by expression of a dominant-negative Fgf receptor, epicardial EMT and coronary neovascularization fail, prematurely arresting regeneration. Our findings reveal injury responses by myocardial and epicardial tissues that collaborate in an Fgf-dependent manner to achieve cardiac regeneration. PMID:17081981

  5. Sonic hedgehog derived from human pancreatic cancer cells augments angiogenic function of endothelial progenitor cells.

    PubMed

    Yamazaki, Madoka; Nakamura, Kazumasa; Mizukami, Yusuke; Ii, Masaaki; Sasajima, Junpei; Sugiyama, Yoshiaki; Nishikawa, Tomoya; Nakano, Yasuhiro; Yanagawa, Nobuyuki; Sato, Kazuya; Maemoto, Atsuo; Tanno, Satoshi; Okumura, Toshikatsu; Karasaki, Hidenori; Kono, Toru; Fujiya, Mikihiro; Ashida, Toshifumi; Chung, Daniel C; Kohgo, Yutaka

    2008-06-01

    Hedgehog signaling is important in the pathogenesis of pancreatic cancer. Several recent observations suggest the involvement of sonic hedgehog (SHH) in postnatal neovascularization. We identified a novel role for SHH in tumor-associated angiogenesis in pancreatic cancer. Immunohistochemical analysis revealed that patched homolog 1 (PTCH1), both a receptor for and transcriptional target of hedgehog signaling, was expressed in a small fraction of endothelial cells within pancreatic cancer, but not in normal pancreatic tissue. When endothelial progenitor cells (EPC) isolated from human peripheral blood were cultured with supernatant from SHH-transfected 293 cells or pancreatic cancer cells, mRNA levels of vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 and angiopoietin-1 were significantly increased, whereas no such induction was observed in human umbilical vein endothelial cell (HUVEC) and human dermal microvascular endothelial cell (HMVEC). HUVEC tube formation was stimulated when cocultured with EPC, and preconditioning EPC with supernatant from KP-1 N pancreatic cancer cells highly expressing SHH significantly enhanced the effect. The effect was partially attenuated by specific inhibition of SHH with cyclopamine or a neutralizing antibody. These findings suggest that tumor-derived SHH can induce angiogenesis, and this is mediated by its effects on EPC specifically. Targeting SHH would be a novel therapeutic approach that can inhibit not only proliferation of cancer cells but also EPC-mediated angiogenesis. PMID:18422746

  6. Endothelial Progenitor Cells in Tumor Angiogenesis: Another Brick in the Wall

    PubMed Central

    Marçola, Marina; Rodrigues, Camila Eleuterio

    2015-01-01

    Until 15 years ago, vasculogenesis, the formation of new blood vessels from undifferentiated cells, was thought to occur only during embryonic development. The discovery of circulating cells that are able to promote vascular regeneration and repair—the so-called endothelial progenitor cells (EPCs)—changed that, and EPCs have since been studied extensively. It is already known that EPCs include many subtypes of cells that play a variety of roles in promoting vascular growth. Some EPCs are destined to differentiate into endothelial cells, whereas others are capable of promoting and sustaining angiogenesis through paracrine mechanisms. Vasculogenesis and angiogenesis might constitute complementary mechanisms for postnatal neovascularization, and EPCs could be at the core of this process. Although the formation of new blood vessels from preexisting vasculature plays a beneficial role in many physiological processes, such as wound healing, it also contributes to tumor growth and metastasis. However, many aspects of the role played by EPCs in tumor angiogenesis remain unclear. This review aims to address the main aspects of EPCs differentiation and certain characteristics of their main function, especially in tumor angiogenesis, as well as the potential clinical applications. PMID:26000021

  7. Endothelial progenitor cells in tumor angiogenesis: another brick in the wall.

    PubMed

    Marçola, Marina; Rodrigues, Camila Eleuterio

    2015-01-01

    Until 15 years ago, vasculogenesis, the formation of new blood vessels from undifferentiated cells, was thought to occur only during embryonic development. The discovery of circulating cells that are able to promote vascular regeneration and repair-the so-called endothelial progenitor cells (EPCs)-changed that, and EPCs have since been studied extensively. It is already known that EPCs include many subtypes of cells that play a variety of roles in promoting vascular growth. Some EPCs are destined to differentiate into endothelial cells, whereas others are capable of promoting and sustaining angiogenesis through paracrine mechanisms. Vasculogenesis and angiogenesis might constitute complementary mechanisms for postnatal neovascularization, and EPCs could be at the core of this process. Although the formation of new blood vessels from preexisting vasculature plays a beneficial role in many physiological processes, such as wound healing, it also contributes to tumor growth and metastasis. However, many aspects of the role played by EPCs in tumor angiogenesis remain unclear. This review aims to address the main aspects of EPCs differentiation and certain characteristics of their main function, especially in tumor angiogenesis, as well as the potential clinical applications. PMID:26000021

  8. STELLAR BINARY COMPANIONS TO SUPERNOVA PROGENITORS

    SciTech Connect

    Kochanek, Christopher S.

    2009-12-20

    For typical models of binary statistics, 50%-80% of core-collapse supernova (ccSN) progenitors are members of a stellar binary at the time of the explosion. Independent of any consequences of mass transfer, this has observational consequences that can be used to study the binary properties of massive stars. In particular, the secondary companion to the progenitor of a Type Ib/c SN is frequently (approx50%) the more optically luminous star since the high effective temperatures of the stripped progenitors make it relatively easy for a lower luminosity, cooler secondary to emit more optical light. Secondaries to the lower mass progenitors of Type II SN will frequently produce excess blue emission relative to the spectral energy distribution of the red primary. Available data constrain the models weakly. Any detected secondaries also provide an independent lower bound on the progenitor mass and, for historical SN, show that it was not a Type Ia event. Bright ccSN secondaries have an unambiguous, post-explosion observational signature-strong, blueshifted, relatively broad absorption lines created by the developing SN remnant (SNR). These can be used to locate historical SN with bright secondaries, confirm that a source is a secondary, and, potentially, measure abundances of ccSN ejecta. Luminous, hot secondaries will re-ionize the SNR on timescales of 100-1000 yr that are faster than re-ionization by the reverse shock, creating peculiar H II regions due to the high metallicity and velocities of the ejecta.

  9. Gene Therapy with Endogenous Inhibitors of Angiogenesis for Neovascular Age-Related Macular Degeneration: Beyond Anti-VEGF Therapy

    PubMed Central

    Prea, Selwyn M.; Chan, Elsa C.; Dusting, Gregory J.; Vingrys, Algis J.; Bui, Bang V.

    2015-01-01

    Age-related macular degeneration (AMD) is the leading cause of substantial and irreversible vision loss amongst elderly populations in industrialized countries. The advanced neovascular (or “wet”) form of the disease is responsible for severe and aggressive loss of central vision. Current treatments aim to seal off leaky blood vessels via laser therapy or to suppress vessel leakage and neovascular growth through intraocular injections of antibodies that target vascular endothelial growth factor (VEGF). However, the long-term success of anti-VEGF therapy can be hampered by limitations such as low or variable efficacy, high frequency of administration (usually monthly), potentially serious side effects, and, most importantly, loss of efficacy with prolonged treatment. Gene transfer of endogenous antiangiogenic proteins is an alternative approach that has the potential to provide long-term suppression of neovascularization and/or excessive vascular leakage in the eye. Preclinical studies of gene transfer in a large animal model have provided impressive preliminary results with a number of transgenes. In addition, a clinical trial in patients suffering from advanced neovascular AMD has provided proof-of-concept for successful gene transfer. In this mini review, we summarize current theories pertaining to the application of gene therapy for neovascular AMD and the potential benefits when used in conjunction with endogenous antiangiogenic proteins. PMID:25821585

  10. Exploring the Progenitors of Fast Radio Bursts

    NASA Astrophysics Data System (ADS)

    Burke-Spolaor, Sarah; Kramer, Michael; Bhat, Ramesh; Kulkarni, S. R.; Keller, Stefan; Champion, David; Flynn, Chris; Kasliwal, Mansi

    2014-10-01

    Fast Radio Bursts (FRBs) are millisecond bursts that are broadly evidenced to arise from extragalactic, but yet unknown, progenitors. They have presented a true mystery in that so far no progenitor theory can adequately account for their observed properties. We request observations that will glean basic information on FRB progenitors. Our observations will execute a specific test of whether FRBs originate in nearby galaxies. We have also designed our target field and time request to enable a thorough exploration of optical counterparts before, during, and after any detected FRB episode. Additionally, with a number depending on the typical distance to FRBs, our observations will raise the running list of total FRB discoveries by 10-60%.

  11. Progenitor cells in the adult pancreas.

    PubMed

    Holland, Andrew M; Góñez, L Jorge; Harrison, Leonard C

    2004-01-01

    The beta-cell mass in the adult pancreas possesses the ability to undergo limited regeneration following injury. Identifying the progenitor cells involved in this process and understanding the mechanisms leading to their maturation will open new avenues for the treatment of type 1 diabetes. However, despite steady advances in determining the molecular basis of early pancreatic development, the identification of pancreatic stem cells or beta-cell progenitors and the molecular mechanisms underlying beta-cell regeneration remain unclear. Recent advances in the directed differentiation of embryonic and adult stem cells has heightened interest in the possible application of stem cell therapy in the treatment of type 1 diabetes. Drawing on the expanding knowledge of pancreas development, beta-cell regeneration and stem cell research, this review focuses on progenitor cells in the adult pancreas as a potential source of beta-cells. PMID:14737742

  12. Derivation of high-purity oligodendroglial progenitors.

    PubMed

    Hatch, Maya N; Nistor, Gabriel; Keirstead, Hans S

    2009-01-01

    Oligodendrocytes are a type of glial cells that play a critical role in supporting the central nervous system (CNS), in particular insulating axons within the CNS by wrapping them with a myelin sheath, thereby enabling saltatory conduction. They are lost, and myelin damaged - demyelination - in a wide variety of neurological disorders. Replacing depleted cell types within demyelinated areas, however, has been shown experimentally to achieve remyelination and so help restore function. One method to produce oligodendrocytes for cellular replacement therapies is through the use of progenitor or stem cells. The ability to differentiate progenitor or stem cells into high-purity fates not only permits the generation of specific cells for transplantation therapies, but also provides powerful tools for studying cellular mechanisms of development. This chapter outlines methods of generating high-purity OPCs from multipotent neonatal progenitor or human embryonic stem cells. PMID:19378196

  13. Pigment Cell Progenitors in Zebrafish Remain Multipotent through Metamorphosis.

    PubMed

    Singh, Ajeet Pratap; Dinwiddie, April; Mahalwar, Prateek; Schach, Ursula; Linker, Claudia; Irion, Uwe; Nüsslein-Volhard, Christiane

    2016-08-01

    The neural crest is a transient, multipotent embryonic cell population in vertebrates giving rise to diverse cell types in adults via intermediate progenitors. The in vivo cell-fate potential and lineage segregation of these postembryonic progenitors is poorly understood, and it is unknown if and when the progenitors become fate restricted. We investigate the fate restriction in the neural crest-derived stem cells and intermediate progenitors in zebrafish, which give rise to three distinct adult pigment cell types: melanophores, iridophores, and xanthophores. By inducing clones in sox10-expressing cells, we trace and quantitatively compare the pigment cell progenitors at four stages, from embryogenesis to metamorphosis. At all stages, a large fraction of the progenitors are multipotent. These multipotent progenitors have a high proliferation ability, which diminishes with fate restriction. We suggest that multipotency of the nerve-associated progenitors lasting into metamorphosis may have facilitated the evolution of adult-specific traits in vertebrates. PMID:27453500

  14. Progression of Retinal Pigment Epithelial Atrophy in Antiangiogenic Therapy of Neovascular Age-Related Macular Degeneration

    PubMed Central

    Schütze, Christopher; Wedl, Manuela; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K.; Schmidt-Erfurth, Ursula

    2015-01-01

    Purpose To monitor retinal pigment epithelial (RPE) atrophy progression during antiangiogenic therapy of neovascular age-related macular degeneration (AMD) over 2 years using polarization-sensitive optical coherence tomography (OCT). Design Prospective interventional case series. Methods setting: Clinical practice. study population: Thirty patients (31 eyes) with treatment-naïve neovascular AMD. observation procedures: Standard intravitreal therapy (0.5 mg ranibizumab) was administered monthly during the first year and pro re nata (PRN; as-needed) during the second year. Spectral-domain (SD) OCT and polarization-sensitive OCT (selectively imaging the RPE) examinations were performed at baseline and at 1, 3, 6, 12, and 24 months using a standardized protocol. RPE-related changes were evaluated using a semi-automated polarization-sensitive OCT segmentation algorithm and correlated with SD OCT and fundus autofluorescence (FAF) findings. main outcome measures: RPE response, geographic atrophy (GA) progression. Results Atrophic RPE changes included RPE thinning, RPE porosity, focal RPE atrophy, and development of GA. Early RPE loss (ie, RPE porosity, focal atrophy) increased progressively during initial monthly treatment and remained stable during subsequent PRN-based therapy. GA developed in 61% of eyes at month 24. Mean GA area increased from 0.77 mm2 at 12 months to 1.10 mm2 (standard deviation = 1.09 mm2) at 24 months. Reactive accumulation of RPE-related material at the lesion borders increased until month 3 and subsequently decreased. Conclusions Progressive RPE atrophy and GA developed in the majority of eyes. RPE migration signifies certain RPE plasticity. Polarization-sensitive OCT specifically images RPE-related changes in neovascular AMD, contrary to conventional imaging methods. Polarization-sensitive OCT allows for precisely monitoring the sequence of RPE-related morphologic changes. PMID:25769245

  15. Bevacizumab for neovascular age-related macular degeneration in Chinese patients in a clinical setting

    PubMed Central

    Ng, Danny Siu-Chun; Kwok, Alvin Kwan-Ho; Tong, Justin Man-Kit; Chan, Clement Wai-Nang; Li, Walton Wai-Tat

    2016-01-01

    AIM To determine the outcome of non-investigational treatment with intravitreal bevacizumab (IVB) in neovascular age-related macular degeneration (AMD) patients. METHODS Retrospective chart review of 81 eyes with neovascular AMD followed-up for at least 12mo and received 3-monthly loading IVB injections. Re-treat was based upon the individual clinician's judgment. Best-corrected visual acuity (BCVA) and optical coherence tomography measurements of central foveal thickness outcomes were evaluated at 12, 24mo. RESULTS Eighty-one eyes (of 75 patients) completed 12mo of follow-up and 44 eyes (of 41 patients) completed 24mo of follow-up. The mean baseline logMAR BCVA significantly improved from 0.94±0.69 to 0.85±0.68 at 12mo (P<0.001) and from 0.91±0.65 to 0.85±0.60 (P=0.004) at 24mo. The proportion of eyes that lost <15 logMAR letters at 12mo was 90.1% and at 24mo was 81.8%. IVB was effective in improving visual acuity in both treatment naïve and previous photodynamic therapy (PDT)-treated subgroups. Treatment naive patients required significantly fewer injections than patients with prior PDT. Multiple regression analysis identified that poorer baseline visual acuity was associated with greater improvement in visual acuity (P=0.015). CONCLUSION Fewer injections in clinical practice may result in suboptimal visual outcomes compared with clinical trials of IVB in neovascular AMD patients. Poor baseline visual acuity and prior PDT treatment may also improve vision after IVB. The safety and durability of effect was maintained at 24mo. PMID:27158614

  16. A Rat Model for Choroidal Neovascularization Using Subretinal Lipid Hydroperoxide Injection

    PubMed Central

    Baba, Takayuki; Bhutto, Imran A.; Merges, Carol; Grebe, Rhonda; Emmert, David; McLeod, D. Scott; Armstrong, Donald; Lutty, Gerard A.

    2010-01-01

    The purpose of this study was to develop and characterize a rat model of choroidal neovascularization (CNV) as occurs in age-related macular degeneration. The lipid hydroperoxide 13(S)-hydroperoxy-9Z,11E-octadecadienoic acid (HpODE) is found in submacular Bruch’s membrane in aged humans and has been reported to generate neovascularization in a rabbit model. Three weeks after a single subretinal injection of 30 μg of HpODE, eyes of Sprague-Dawley rats were harvested. Follow-up fluorescein angiography was done on other animals until 5 weeks postinjection. Histological studies, immunohistochemical staining, and flatmount choroids for CNV measurements were performed. In addition, we used murine neuronal, bovine endothelial, and human ARPE19 cells for testing the in vitro effects of HpODE. CNV developed in 85.7% of HpODE-injected eyes. The neovascular areas were significantly greater in HpODE-injected eyes compared with those in control eyes (P = 0.023). The CNV had maximum dye leakage at 3 weeks, which subsided by the 5th week. Histologically, CNV extended from the choriocapillaris into the subretinal space. ED1-positive macrophages were recruited to the site. In vitro assays demonstrated that only 30 ng/ml HpODE induced cell proliferation and migration of endothelial cells. HpODE-induced CNV was highly reproducible, and its natural course seems to be ideal for evaluating therapeutic modalities. Because HpODE has been isolated from aged humans, the HpODE-induced rat model seems to be a relevant experimental model for CNV in age-related macular degeneration. PMID:20395434

  17. Neovascularization of the testicle through spermatic vessels by omental pedicle flap: a new experimental model.

    PubMed

    Sönmez, K; Başaklar, A C; Türkyilmaz, Z; Demiroğullari, B; Numanoğlu, V; Konuş, O; Dursun, A; Altin, M A; Kale, N

    1995-12-01

    The aim of this experimental study in rats was to consider the supplementary role of an omental pedicle flap on the neovascularization of the testicle through the spermatic vessels, for which a Fowler-Stephens procedure had been planned. To compare results, 12 animals had only the spermatic vessels ligated, without an additional procedure (Fowler-Stephens procedure [FS group]), and 12 others had omentopexy of the spermatic vessels of the left testes, with ligation of the vessels 4 weeks later (Fowler-Stephens procedure plus omentopexy [FSO group]). In the sham group (n = 8), only omentopexy of the left spermatic vessels was performed. Six rats served as controls. In each rat, both testes were evaluated by color Doppler ultrasonography to assess capsular and intratesticular blood flow, followed by orchiectomy to determine testicular weights, testicular biopsy scores, and mean seminiferous tubule diameters. Data were analyzed statistically. According to the color Doppler ultrasonography, the testicular blood flow in the FSO group was better than that of the FS group, but was less sufficient than that of the sham and control groups. The testicular weights and biopsy scores for the FSO group were statistically greater than those of the FS group, and less than those of the sham and control groups. There was no significant difference in the mean seminiferous tubule diameters of the FSO and FS groups. The contralateral tests of the four groups did not differ significantly for any parameter. In light of the data available, it is suggested that the omental pedicle flap neovascularizes the testicle through spermatic vessels. Given the high incidence of testicular atrophy associated with Fowler-Stephens orchiopexies, it might be beneficial to perform laparoscopic orchiopexy of testicles neovascularized with omental pedicle flaps as the first-stage procedure. PMID:8749916

  18. OCT angiography in the management of choroidal neovascular membrane secondary to Sorsby fundus dystrophy.

    PubMed

    Mohla, Aditi; Khan, Kamron; Kasilian, Melissa; Michaelides, Michel

    2016-01-01

    We describe the management of a woman aged 52 years with molecularly confirmed Sorsby fundus dystrophy, who presented with acute visual deterioration in her right eye. Fundus examination identified a right macular lesion suggestive of a choroidal neovascular membrane (CNVM). Optical coherence tomography angiography (OCTA) confirmed the presence of a CNVM. She was treated with 2 monthly intravitreal injections of bevacizumab, associated with OCTA evidence of regression of the CNVM and improvement in her visual acuity. OCTA is a novel, non-invasive method of imaging the retinal vasculature. Images are acquired rapidly, with no associated side effects, offering advantages over the current gold standard technique-fundus fluorescein angiography. PMID:27587748

  19. Quantification of choroidal neovascularization vessel length using optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Gao, Simon S.; Liu, Li; Bailey, Steven T.; Flaxel, Christina J.; Huang, David; Li, Dengwang; Jia, Yali

    2016-07-01

    Quantification of choroidal neovascularization (CNV) as visualized by optical coherence tomography angiography (OCTA) may have importance clinically when diagnosing or tracking disease. Here, we present an automated algorithm to quantify the vessel skeleton of CNV as vessel length. Initial segmentation of the CNV on en face angiograms was achieved using saliency-based detection and thresholding. A level set method was then used to refine vessel edges. Finally, a skeleton algorithm was applied to identify vessel centerlines. The algorithm was tested on nine OCTA scans from participants with CNV and comparisons of the algorithm's output to manual delineation showed good agreement.

  20. [Photodynamic therapy with Visudyne in macular degeneration associated with subfoveal classical choroidal neovascularization].

    PubMed

    Soucek, P; Boguzsaková, J; Cihelková, I

    2002-04-01

    Photodynamic therapy with the preparation Visudyne (PDT) is the only treatment which retards statistically significantly the decline of vision in patients with age related and myopic macular degeneration with a subfoveal, predominantly classic choroidal neovascularization. The authors present their own experience with the treatment of the first 12 patients. During 6-month treatment a loss of more than 3 lines of ETDRS optotypes was recorded in two patients (17%). The presented results of FTV are consistent with data published abroad. As the one-year therapeutic results in two patients are encouraging, it will be necessary in future to prolong the follow up time and increase the number of patients. PMID:12046251

  1. Human Liver Progenitor Cells for Liver Repair

    PubMed Central

    Lombard, Catherine A.; Prigent, Julie; Sokal, Etienne M.

    2013-01-01

    Because of their high proliferative capacity, resistance to cryopreservation, and ability to differentiate into hepatocyte-like cells, stem and progenitor cells have recently emerged as attractive cell sources for liver cell therapy, a technique used as an alternative to orthotopic liver transplantation in the treatment of various hepatic ailments ranging from metabolic disorders to end-stage liver disease. Although stem and progenitor cells have been isolated from various tissues, obtaining them from the liver could be an advantage for the treatment of hepatic disorders. However, the techniques available to isolate these stem/progenitor cells are numerous and give rise to cell populations with different morphological and functional characteristics. In addition, there is currently no established consensus on the tests that need to be performed to ensure the quality and safety of these cells when used clinically. The purpose of this review is to describe the different types of liver stem/progenitor cells currently reported in the literature, discuss their suitability and limitations in terms of clinical applications, and examine how the culture and transplantation techniques can potentially be improved to achieve a better clinical outcome. PMID:26858860

  2. In vivo identification of periodontal progenitor cells.

    PubMed

    Roguljic, H; Matthews, B G; Yang, W; Cvija, H; Mina, M; Kalajzic, I

    2013-08-01

    The periodontal ligament contains progenitor cells; however, their identity and differentiation potential in vivo remain poorly characterized. Previous results have suggested that periodontal tissue progenitors reside in perivascular areas. Therefore, we utilized a lineage-tracing approach to identify and track periodontal progenitor cells from the perivascular region in vivo. We used an alpha-smooth muscle actin (αSMA) promoter-driven and tamoxifen-inducible Cre system (αSMACreERT2) that, in combination with a reporter mouse line (Ai9), permanently labels a cell population, termed 'SMA9'. To trace the differentiation of SMA9-labeled cells into osteoblasts/cementoblasts, we utilized a Col2.3GFP transgene, while expression of Scleraxis-GFP was used to follow differentiation into periodontal ligament fibroblasts during normal tissue formation and remodeling following injury. In uninjured three-week-old SMA9 mice, tamoxifen labeled a small population of cells in the periodontal ligament that expanded over time, particularly in the apical region of the root. By 17 days and 7 weeks after labeling, some SMA9-labeled cells expressed markers indicating differentiation into mature lineages, including cementocytes. Following injury, SMA9 cells expanded, and differentiated into cementoblasts, osteoblasts, and periodontal ligament fibroblasts. SMA9-labeled cells represent a source of progenitors that can give rise to mature osteoblasts, cementoblasts, and fibroblasts within the periodontium. PMID:23735585

  3. The progenitors of subluminous type Ia supernovae

    SciTech Connect

    Howell, D. Andrew

    2001-02-01

    We find that spectroscopically peculiar subluminous SNe Ia come from an old population. Of the thirteen subluminous SNe Ia known, nine are found in E/S0 galaxies, and the remainder are found in early-type spirals. The probability that this is a chance occurrence is only 0.1%. The finding that subluminous SNe Ia are associated with an older stellar population indicates that for a sufficiently large lookback time (already accessible in current high redshift searches) they will not be found. Due to a scarcity in old populations, hydrogen and helium main sequence stars and He red giant stars that undergo Roche lobe overflow are unlikely to be the progenitors of subluminous SNe Ia. Earlier findings that overluminous SNe Ia (DELTA m{sub 15} (B) < 0.94) come from a young progenitor population are confirmed. The fact that subluminous SNe Ia and overluminous SNe Ia come from different progenitor populations and also have different properties is a prediction of the CO white dwarf merger progenitor scenario.

  4. SUPERNOVA REMNANT PROGENITOR MASSES IN M31

    SciTech Connect

    Jennings, Zachary G.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Weisz, Daniel R.; Murphy, Jeremiah W.; Dolphin, Andrew E. E-mail: adolphin@raytheon.com

    2012-12-10

    Using Hubble Space Telescope photometry, we age-date 59 supernova remnants (SNRs) in the spiral galaxy M31 and use these ages to estimate zero-age main-sequence masses (M{sub ZAMS}) for their progenitors. To accomplish this, we create color-magnitude diagrams (CMDs) and employ CMD fitting to measure the recent star formation history of the regions surrounding cataloged SNR sites. We identify any young coeval population that likely produced the progenitor star, then assign an age and uncertainty to that population. Application of stellar evolution models allows us to infer the M{sub ZAMS} from this age. Because our technique is not contingent on identification or precise location of the progenitor star, it can be applied to the location of any known SNRs. We identify significant young star formation around 53 of the 59 SNRs and assign progenitor masses to these, representing a factor of {approx}2 increase over currently measured progenitor masses. We consider the remaining six SNRs as either probable Type Ia candidates or the result of core-collapse progenitors that have escaped their birth sites. In general, the distribution of recovered progenitor masses is bottom-heavy, showing a paucity of the most massive stars. If we assume a single power-law distribution, dN/dM{proportional_to}M{sup {alpha}}, then we find a distribution that is steeper than a Salpeter initial mass function (IMF) ({alpha} = -2.35). In particular, we find values of {alpha} outside the range -2.7 {>=} {alpha} {>=} -4.4 to be inconsistent with our measured distribution at 95% confidence. If instead we assume a distribution that follows a Salpeter IMF up to some maximum mass, then we find that values of M{sub Max} > 26 are inconsistent with the measured distribution at 95% confidence. In either scenario, the data suggest that some fraction of massive stars may not explode. The result is preliminary and requires more SNRs and further analysis. In addition, we use our distribution to estimate a

  5. Quantitative proteomic analysis of mice corneal tissues reveals angiogenesis-related proteins involved in corneal neovascularization.

    PubMed

    Shen, Minqian; Tao, Yimin; Feng, Yifan; Liu, Xing; Yuan, Fei; Zhou, Hu

    2016-07-01

    Corneal neovascularization (CNV) was induced in Balb/c mice by alkali burns in the central area of the cornea with a diameter of 2.5mm. After fourteen days, the cornea from one eye was collected for histological staining for CNV examination, while the cornea from the other eye of the same mouse was harvested for proteomic analysis. The label-free quantitative proteomic approach was applied to analyze five normal corneal tissues (normal group mice n=5) and five corresponding neovascularized corneal tissues (model group mice n=5). A total of 2124 proteins were identified, and 1682 proteins were quantified from these corneal tissues. Among these quantified proteins, 290 proteins were significantly changed between normal and alkali burned corneal tissues. Of these significantly changed proteins, 35 were reported or predicted as angiogenesis-related proteins. Then, these 35 proteins were analyzed using Ingenuity Pathway Analysis Software, resulting in 26 proteins enriched and connected to each other in the protein-protein interaction network, such as Lcn-2, αB-crystallin and Serpinf1 (PEDF). These three significantly changed proteins were selected for further Western blotting validation. Consistent with the quantitative proteomic results, Western blotting showed that Lcn-2 and αB-crystallin were significantly up-regulated in CNV model, while PEDF was down-regulated. This study provided increased understanding of angiogenesis-related proteins involved in corneal vascular development, which will be useful in the ophthalmic clinic of specifically target angiogenesis. PMID:27049463

  6. RECURRENT CHOROIDAL NEOVASCULARIZATION AFTER MACULAR TRANSLOCATION SURGERY WITH 360-DEGREE PERIPHERAL RETINECTOMY

    PubMed Central

    BAER, CLAXTON A.; RICKMAN, CATHERINE BOWES; SRIVASTAVA, SUNIL; MALEK, GOLDIS; STINNETT, SANDRA; TOTH, CYNTHIA A.

    2012-01-01

    Purpose To evaluate the pattern of age-related macular degeneration in the new foveal location after macular translocation surgery with 360 degree peripheral retinectomy for neovascular age-related macular degeneration. Methods Clinical data, fundus photos, and fluorescein angiograms of patients in the Duke Macular Translocation Study were reviewed with 2-year follow-up data. Results With 56 patients completing follow-up, no patient developed de novo choroidal neovascularization (CNV), geographic atrophy, or drusen in the new subfoveal retinal pigment epithelium bed. By 2 years, 14 patients (25%) developed recurrent CNV and 13 of these 14 recurrences clearly arose from the old CNV bed. Of the 13 recurrences clearly arising from the old bed, 12 of them had recurrent CNV that involved the margin of the bed closest to the repositioned fovea. Smokers were 5.3 times (95% confidence interval: 1.2–24) more likely to develop recurrent CNV over 2 years. Despite treatment, median visual acuity for the 14 eyes with recurrent CNV was 20/200 compared with 20/80 in eyes without recurrence. Conclusions Findings in this study support the hypotheses that the development of CNV occurs via a signaling mechanism from the fovea. PMID:18626416

  7. Anti-Human VEGF Repebody Effectively Suppresses Choroidal Neovascularization and Vascular Leakage

    PubMed Central

    Hwang, Da-Eun; Ryou, Jeong-Hyun; Oh, Jong Rok; Han, Jung Woo; Park, Tae Kwann; Kim, Hak-Sung

    2016-01-01

    Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness among people over the age of 60. Vascular endothelial growth factor (VEGF) plays a major role in pathological angiogenesis in AMD. Herein, we present the development of an anti- human VEGF repebody, which is a small-sized protein binder consisting of leucine-rich repeat (LRR) modules. The anti-VEGF repebody selected through a phage-display was shown to have a high affinity and specificity for human VEGF. We demonstrate that this repebody effectively inhibits in vitro angiogenic cellular processes, such as proliferation and migration, by blocking the VEGF-mediated signaling pathway. The repebody was also shown to have a strong suppression effect on choroidal neovascularization (CNV) and vascular leakage in vivo. Our results indicate that the anti-VEGF repebody has a therapeutic potential for treating neovascular AMD as well as other VEGF-involved diseases including diabetic retinopathy and metastatic cancers. PMID:27015541

  8. Gemcitabine-induced CXCL8 expression counteracts its actions by inducing tumor neovascularization

    SciTech Connect

    Song, Yao; Baba, Tomohisa; Li, Ying-Yi; Furukawa, Kaoru; Tanabe, Yamato; Matsugo, Seiichi; Sasaki, Soichiro; Mukaida, Naofumi

    2015-03-06

    Patients with pancreatic ductal adenocarcinoma (PDAC) are frequently complicated with metastatic disease or locally advanced tumors, and consequently need chemotherapy. Gemcitabine is commonly used for PDAC treatment, but with limited efficacy. The capacity of gemcitabine to generate reactive oxygen species (ROS) in human pancreatic cancer cells, prompted us to examine its effects on the expression of pro-inflammatory cytokines and chemokines. We observed that gemcitabine enhanced selectively the expression of CXCL8 in human pancreatic cancer cells through ROS generation and NF-κB activation. In vitro blocking of CXCL8 failed to modulate gemcitabine-mediated inhibition of cell proliferation in human pancreatic cancer cells. Gemcitabine also enhanced CXCL8 expression in pancreatic cancer cells in xenografted tumor tissues. Moreover, anti-CXCL8 antibody treatment in vivo attenuated tumor formation as well as intra-tumoral vascularity in nude mice, which were transplanted with Miapaca-2 cells and treated with gemcitabine. Thus, gemcitabine-induced CXCL8 may counteract the drug through inducing neovascularization. - Highlights: • Gemcitabine induced CXCL8 expression in human pancreatic cancer cells. • CXCL8 expression required ROS generation and NF-κB activation. • CXCL8 did not affect in vitro proliferation of human pancreatic cancer cells. • CXCL8 in vivo counteracted gemcitabine by inducing neovascularization.

  9. Minimizing projection artifacts for accurate presentation of choroidal neovascularization in OCT micro-angiography.

    PubMed

    Zhang, Anqi; Zhang, Qinqin; Wang, Ruikang K

    2015-10-01

    Current optical coherence tomography (OCT) based micro-angiography is prone to a projection (or tailing) effect due to the high scattering property of blood within overlying patent vessels, creating artifacts that interfere with the interpretation of retinal angiographic results. In this work, the projection effect in OCT micro-angiography is examined and its causality is explained by strong light scattering and photon propagation within blood. A simple practical approach is then introduced to minimize these artifacts presented in the outer retinal avascular space, especially useful for examining clinical cases with choroidal neovascularization (CNV). Demonstrated through in-vivo human posterior eye imaging of healthy and CNV subjects, the proposed method is shown effective to eliminate the projection artifacts in outer retinal space of OCT micro-angiography, resulting in better visualization of the pathological neovascularization when compared with the current common approaches. In addition, it is also shown that the proposed method is applicable to minimize the projection artifacts appearing in deep retinal layers. PMID:26504660

  10. Downregulation of p22phox in Retinal Pigment Epithelial Cells Inhibits Choroidal Neovascularization in Mice

    PubMed Central

    Li, Qiuhong; Dinculescu, Astra; Shan, Zhiying; Miller, Rehae; Pang, Jijing; Lewin, Alfred S; Raizada, Mohan K; Hauswirth, William W

    2016-01-01

    Choroidal neovascularization (CNV) occurs in a variety of chorioretinal diseases including age-related macular degeneration (AMD), and is the major cause of severe visual loss in patients with AMD. Oxidative stress has been thought to play an important role in the development of CNV. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is one of the major intracellular sources of reactive oxygen species (ROS) in the vascular system. In this study, we examined the expression of p22phox, an integral subunit in the NADPH oxidase complex, in the mouse eye. We determined that p22phox is expressed in the retinal pigment epithelial (RPE) cells and inner retinal neurons. A small-interfering RNA (siRNA) designed against p22phox efficiently reduced the expression of the protein in the eye when delivered by means of recombinant adeno-associated virus (AAV) vector. Vector treatment inhibited CNV in the mouse when delivered into the subretinal space where RPE cells were transduced. These results suggest that NADPH oxidase–mediated ROS production in RPE cells may play an important role in the pathogenesis of neovascular AMD, and that this pathway may represent a new target for therapeutic intervention in AMD. PMID:18665154

  11. Neovascularization Capacity of Mesenchymal Stromal Cells From Critical Limb Ischemia Patients Is Equivalent to Healthy Controls

    PubMed Central

    Gremmels, Hendrik; Teraa, Martin; Quax, Paul HA; den Ouden, Krista; Fledderus, Joost O; Verhaar, Marianne C

    2014-01-01

    Critical limb ischemia (CLI) is often poorly treatable by conventional management and alternatives such as autologous cell therapy are increasingly investigated. Whereas previous studies showed a substantial impairment of neovascularization capacity in primary bone-marrow (BM) isolates from patients, little is known about dysfunction in patient-derived BM mesenchymal stromal cells (MSCs). In this study, we have compared CLI-MSCs to healthy controls using gene expression profiling and functional assays for differentiation, senescence and in vitro and in vivo pro-angiogenic ability. Whereas no differentially expressed genes were found and adipogenic and osteogenic differentiation did not significantly differ between groups, chondrogenic differentiation was impaired in CLI-MSCs, potentially as a consequence of increased senescence. Migration experiments showed no differences in growth factor sensitivity and secretion between CLI- and control MSCs. In a murine hind-limb ischemia model, recovery of perfusion was enhanced in MSC-treated mice compared to vehicle controls (71 ± 24% versus 44 ± 11%; P < 1 × 10−6). CLI-MSC- and control-MSC–treated animals showed nearly identical amounts of reperfusion (ratio CLI:Control = 0.98, 95% CI = 0.82–1.14), meeting our criteria for statistical equivalence. The neovascularization capacity of MSCs derived from CLI-patients is not compromised and equivalent to that of control MSCs, suggesting that autologous MSCs are suitable for cell therapy in CLI patients. PMID:25174586

  12. Significance of retinal laser lesion location and subretinal hemorrhage in bridging choroidal neovascular complexes

    NASA Astrophysics Data System (ADS)

    Schuschereba, Steven T.; Clarkson, Donna R.; Valo, Lynn M.; Brown, Jeremiah, Jr.; Stuck, Bruce E.

    2003-06-01

    Purpose: To determine funduscopic criteria that will help predict when bridging choroidal neovascular (CNV) complexes will develop after laser retinal trauma and to define early preventive treatment targets. Methods: Ten rhesus monkeys were used and retinal lesions were produced by Nd:YAG exposures (20ns, 1-2mJ, 1064nm, min. spot size) simulating human accidental laser trauma to the central fundus. Funduscopy and fluorescein/ICG angiography were conducted at day 1, 4, and 14, and at 2 and 4 months, and animals terminated for histologic evaluation. Predisposition for bridging fibrovascular complexes was evaluated for single lesions, two small lesions showing coalescing hemorrhages, and multiple lesions involved with large field subretinal and vitreous hemorrhages. Results: Elevated CNVs were present in all single lesions with confined subretinal hemorrhages. All lesion sets that showed initial and small coalescing subretinal hemorrhages formed bridging CNV scars. No bridging CNVs occurred in lesion sets involving a vitreous hemorrhage adjacent to a confined, but small subretinal hemorrhage. In large field subretinal hemorrhages involving multiple laser lesions, complex CNV formation occurred. Extensive secondary photoreceptor losses occurred in confined hemorrhage and CNV zones. Conclusion: Trauma presenting with evidence of coalescing and confined subretinal hemorrhages between two adjacent lesions has a high chance of forming choroidal neovascular bridge complexes between the involved lesions. CNV formation may be related to the long residence time, break down products, and clearance processes of extravasated blood. Removal of trapped blood and curtailing angiogenesis and cellular proliferation may be helpful treatment strategies.

  13. Intravitreal bevacizumab for choroidal neovascularization secondary to angioid streaks: A report of two patients

    PubMed Central

    Ozkaya, Abdullah; Alkin, Zeynep; Faiz, Miray; Yazici, Ahmet Taylan; Demirok, Ahmet

    2013-01-01

    The aim of this study is to report clinical course of choroidal neovascularization secondary to angioid streaks (AS) in two patients who underwent intravitreal bevacizumab therapy. Fundus examination, fluorescein angiography (FA) and optical coherence tomography (OCT) revealed the diagnosis of subfoveal classic choroidal neovascularization (CNV) in the right eye in patient 1 and in the left eye in patient 2. After three consecutive bevacizumab injections, visual acuity improved from 20/40 to 20/25 in patient 1 and from 20/80 to 20/50 in patient 2. After 3 months of therapy, additional bevacizumab injection was administered when the lesion showed recurrence. After a follow-up time of 24-months, patient 1 received 14 intravitreal bevacizumab injections; patient 2 received only 4 injections. Visual acuities remained stable at 20/32 and 20/50 in patient 1 and patient 2, respectively. Though, the patients of CNV secondary to AS showed similar clinical appearance at the beginning, this report provides the data for different responses to intravitreal bevacizumab therapy. While fewer injections were required to control the disease in one patient, the other patient needed much more injections for stabilization of the CNV. Further studies are required to understand the cause of varied treatment responses in those patients. PMID:25473350

  14. Pulsed electromagnetic field improves postnatal neovascularization in response to hindlimb ischemia

    PubMed Central

    Li, Rui-Lin; Huang, Jing-Juan; Shi, Yi-Qin; Hu, An; Lu, Zhao-Yang; Weng, Liang; Wang, Shen-Qi; Han, Yi-Peng; Zhang, Lan; Hao, Chang-Ning; Duan, Jun-Li

    2015-01-01

    Pulsed electromagnetic fields (PEMF) have been shown to promote proliferation and regeneration in the damaged tissue. Here, we examined whether PEMF therapy improved postnatal neovascularization using murine model of hindlimb ischemia, and the underlying cellular/molecular mechanisms were further investigated. Hindlimb ischemia was induced by unilateral femoral artery resection using 6-8 week-old male C57BL6 mice. Then, mice were exposed to extracorporeal PEMF therapy (4 cycles, 8min/cycle, 30 ± 3 Hz, 5 mT) every day until day 14. Our data demonstrated that PEMF therapy significantly accelerated wound healing, decreased prevalence of gangrene and increased postnatal neovascularization. Moreover, the levels of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS) and Akt phosphorylation in ischemic muscles were markedly enhanced following PEMF therapy. In vitro, PEMF inhibited the process of hypoxia-induced apoptosis and augmented tube formation, migration and proliferative capacities of human umbilical vein endothelial cells (HUVECs). Additionally, PEMF exposure increased VEGF secretion, as well as the eNOS and Akt phosphorylation, and these benefits could be blocked by either phosphoinositide 3-kinase (PI3K) or eNOS inhibitor. In conclusion, our data indicated that PEMF therapy enhanced ischemia-mediated angiogenesis, through up-regulating VEGF expression and activating the PI3K-Akt-eNOS pathway. Therefore, PEMF should be a valuable treatment for the patients with critical limb ischemia. PMID:26045885

  15. Interferon-beta signaling in retinal mononuclear phagocytes attenuates pathological neovascularization.

    PubMed

    Lückoff, Anika; Caramoy, Albert; Scholz, Rebecca; Prinz, Marco; Kalinke, Ulrich; Langmann, Thomas

    2016-01-01

    Age-related macular degeneration (AMD) is a leading cause of vision loss among the elderly. AMD pathogenesis involves chronic activation of the innate immune system including complement factors and microglia/macrophage reactivity in the retina. Here, we show that lack of interferon-β signaling in the retina accelerates mononuclear phagocyte reactivity and promotes choroidal neovascularization (CNV) in the laser model of neovascular AMD Complete deletion of interferon-α/β receptor (Ifnar) using Ifnar1(-/-) mice significantly enhanced early microglia and macrophage activation in lesion areas. This triggered subsequent vascular leakage and CNV at later stages. Similar findings were obtained in laser-treated Cx3cr1(Cre) (ER):Ifnar1(fl/fl) animals that allowed the tamoxifen-induced conditional depletion of Ifnar in resident mononuclear phagocytes only. Conversely, systemic IFN-β therapy of laser-treated wild-type animals effectively attenuated microgliosis and macrophage responses in the early stage of disease and significantly reduced CNV size in the late phase. Our results reveal a protective role of Ifnar signaling in retinal immune homeostasis and highlight a potential use for IFN-β therapy in the eye to limit chronic inflammation and pathological angiogenesis in AMD. PMID:27137488

  16. Visible light optical spectroscopy is sensitive to neovascularization in the dysplastic cervix

    NASA Astrophysics Data System (ADS)

    Chang, Vivide Tuan-Chyan; Bean, Sarah M.; Cartwright, Peter S.; Ramanujam, Nirmala

    2010-09-01

    Neovascularization in cervical intraepithelial neoplasia (CIN) is studied because it is the precursor to the third most common female cancer worldwide. Diffuse reflectance from 450-600 nm was collected from 46 patients (76 sites) undergoing colposcopy at Duke University Medical Center. Total hemoglobin, derived using an inverse Monte Carlo model, significantly increased in CIN 2+ (N=12) versus CIN 1 (N=16) and normal tissues (N=48) combined with P<0.004. Immunohistochemistry using monoclonal anti-CD34 was used to quantify microvessel density to validate the increased hemoglobin content. Biopsies from 51 sites were stained, and up to three hot spots per slide were selected for microvessel quantification by two observers. Similar to the optical study results, microvessel density was significantly increased in CIN 2+ (N=16) versus CIN 1 (N=21) and normal tissue (N=14) combined with P<0.007. Total vessel density, however, was not significantly associated with dysplastic grade. Hence, our quantitative optical spectroscopy system is primarily sensitive to dysplastic neovascularization immediately beneath the basement membrane, with minimal confounding from vascularity inherent in the normal stromal environment. This tool could have potential for in vivo applications in screening for cervical cancer, prognostics, and monitoring of antiangiogenic effects in chemoprevention therapies.

  17. Minimizing projection artifacts for accurate presentation of choroidal neovascularization in OCT micro-angiography

    PubMed Central

    Zhang, Anqi; Zhang, Qinqin; Wang, Ruikang K.

    2015-01-01

    Current optical coherence tomography (OCT) based micro-angiography is prone to a projection (or tailing) effect due to the high scattering property of blood within overlying patent vessels, creating artifacts that interfere with the interpretation of retinal angiographic results. In this work, the projection effect in OCT micro-angiography is examined and its causality is explained by strong light scattering and photon propagation within blood. A simple practical approach is then introduced to minimize these artifacts presented in the outer retinal avascular space, especially useful for examining clinical cases with choroidal neovascularization (CNV). Demonstrated through in-vivo human posterior eye imaging of healthy and CNV subjects, the proposed method is shown effective to eliminate the projection artifacts in outer retinal space of OCT micro-angiography, resulting in better visualization of the pathological neovascularization when compared with the current common approaches. In addition, it is also shown that the proposed method is applicable to minimize the projection artifacts appearing in deep retinal layers. PMID:26504660

  18. Pulsed electromagnetic field improves postnatal neovascularization in response to hindlimb ischemia.

    PubMed

    Li, Rui-Lin; Huang, Jing-Juan; Shi, Yi-Qin; Hu, An; Lu, Zhao-Yang; Weng, Liang; Wang, Shen-Qi; Han, Yi-Peng; Zhang, Lan; Hao, Chang-Ning; Duan, Jun-Li

    2015-01-01

    Pulsed electromagnetic fields (PEMF) have been shown to promote proliferation and regeneration in the damaged tissue. Here, we examined whether PEMF therapy improved postnatal neovascularization using murine model of hindlimb ischemia, and the underlying cellular/molecular mechanisms were further investigated. Hindlimb ischemia was induced by unilateral femoral artery resection using 6-8 week-old male C57BL6 mice. Then, mice were exposed to extracorporeal PEMF therapy (4 cycles, 8min/cycle, 30 ± 3 Hz, 5 mT) every day until day 14. Our data demonstrated that PEMF therapy significantly accelerated wound healing, decreased prevalence of gangrene and increased postnatal neovascularization. Moreover, the levels of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS) and Akt phosphorylation in ischemic muscles were markedly enhanced following PEMF therapy. In vitro, PEMF inhibited the process of hypoxia-induced apoptosis and augmented tube formation, migration and proliferative capacities of human umbilical vein endothelial cells (HUVECs). Additionally, PEMF exposure increased VEGF secretion, as well as the eNOS and Akt phosphorylation, and these benefits could be blocked by either phosphoinositide 3-kinase (PI3K) or eNOS inhibitor. In conclusion, our data indicated that PEMF therapy enhanced ischemia-mediated angiogenesis, through up-regulating VEGF expression and activating the PI3K-Akt-eNOS pathway. Therefore, PEMF should be a valuable treatment for the patients with critical limb ischemia. PMID:26045885

  19. Resveratrol Inhibits Hypoxia-Induced Vascular Endothelial Growth Factor Expression and Pathological Neovascularization

    PubMed Central

    Lee, Christopher Seungkyu; Choi, Eun Young; Lee, Sung Chul; Koh, Hyoung Jun; Lee, Joon Haeng

    2015-01-01

    Purpose To investigate the effects of resveratrol on the expression of hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF) in human adult retinal pigment epithelial (ARPE-19) cells, and on experimental choroidal neovascularization (CNV) in mice. Materials and Methods ARPE-19 cells were treated with different concentrations of resveratrol and then incubated under hypoxic conditions with subsequent evaluation of cell viability, expression of HIF-1α, and expression of VEGF. The effects of resveratrol on the synthesis and degradation of hypoxia-induced HIF-1α were evaluated using inhibitors of the PI3K/Akt/mTOR and the ubiquitin proteasome pathways. In animal studies, CNV lesions were induced in C57BL/6 mice by laser photocoagulation. After 7 days of oral administration of resveratrol or vehicle, which began one day after CNV induction, image analysis was used to measure CNV areas on choroidal flat mounts stained with isolectin IB4. Results In ARPE-19 cells, resveratrol significantly inhibited HIF-1α and VEGF in a dose-dependent manner, by blocking the PI3K/Akt/mTOR signaling pathway and by promoting proteasomal HIF-1α degradation. In mice experiments, orally administered resveratrol significantly inhibited CNV growth in a dose-dependent manner. Conclusion Resveratrol may have therapeutic value in the management of diseases involving pathological neovascularization. PMID:26446654

  20. Effects of intravitreal injection of netrin-1 in retinal neovascularization of streptozotocin-induced diabetic rats

    PubMed Central

    Yu, Yao; Zou, Jing; Han, Yun; Quyang, Luowa; He, Hui; Hu, Peihong; Shao, Yi; Tu, Ping

    2015-01-01

    Background In a previous study, we confirmed that netrin-1 acts as an antiangiogenic factor by inhibiting alkali burn-induced corneal neovascularization in rats. Here, we continue working on the role of netrin-1 in retinal neovascularization. Methods Using an in vitro angiogenesis assay, we detected the effects of netrin-1 on human umbilical vein endothelial cell tube formation, viability and proliferation, migration, and invasion at concentrations of 0.1 μg/mL or 5 μg/mL. We intravitreally injected 0.1 μg/mL or 5 μg/mL netrin-1 into streptozotocin-induced rats to assess retinal neovascularization using retinal electrophysiology and electroretinography, enzyme-linked immunosorbent assay, fundus fluoresce in angiography, measurement of inner blood retinal barrier, retinal hematoxylin-eosin staining, and retinal flat-mount fluorescence assays. Results Human umbilical vein endothelial cell tube formation, viability and proliferation, migration, and invasion were upregulated by netrin-1 at a concentration of 0.1 μg/mL (P<0.05), while 5 μg/mL netrin-1 had an opposite effect (P<0.05) in our in vitro angiogenesis assay. Retinal electrophysiology testing revealed that intravitreal injection of netrin-1 affected the amplitude of a- and b-waves (a-wave: 0.1 μg/mL netrin-1 =17.67±3.39 μm, 5 μg/mL netrin-1 =28.50±1.31 μm, phosphate-buffered saline [PBS]-treated =17.67±3.39 μm; b-wave: 0.1 μg/mL netrin-1 =44.67±4.80 μm, 5 μg/mL netrin-1 =97.17±9.63 μm, PBS-treated =44.67±4.80 μm) and the expression of VEGF-A (no-treatment rats, 9.29±0.80 pg/mL; PBS-treated rats, 19.64±3.77 pg/mL; 0.1 μg/mL netrin-1 treated rats, 21.37±3.64 pg/mL; 5 μg/mL netrin-1 treated rats, 9.85±0.54 pg/mL, at 6 weeks after induction). By comparing fluoresce in angiography, level of inner blood retinal barrier breakdown (% of control), retinal hematoxylin-eosin staining, and collagen-IV fluorescence assays in the retinas of PBS-treated rats, netrin-1 was found to suppress and

  1. Schwann cells induce cancer cell dispersion and invasion

    PubMed Central

    Deborde, Sylvie; Lyubchik, Anna; Zhou, Yi; He, Shizhi; McNamara, William F.; Chernichenko, Natalya; Lee, Sei-Young; Barajas, Fernando; Chen, Chun-Hao; Bakst, Richard L.; Vakiani, Efsevia; He, Shuangba; Hall, Alan; Wong, Richard J.

    2016-01-01

    Nerves enable cancer progression, as cancers have been shown to extend along nerves through the process of perineural invasion, which carries a poor prognosis. Furthermore, the innervation of some cancers promotes growth and metastases. It remains unclear, however, how nerves mechanistically contribute to cancer progression. Here, we demonstrated that Schwann cells promote cancer invasion through direct cancer cell contact. Histological evaluation of murine and human cancer specimens with perineural invasion uncovered a subpopulation of Schwann cells that associates with cancer cells. Coculture of cancer cells with dorsal root ganglion extracts revealed that Schwann cells direct cancer cells to migrate toward nerves and promote invasion in a contact-dependent manner. Upon contact, Schwann cells induced the formation of cancer cell protrusions in their direction and intercalated between the cancer cells, leading to cancer cell dispersion. The formation of these processes was dependent on Schwann cell expression of neural cell adhesion molecule 1 (NCAM1) and ultimately promoted perineural invasion. Moreover, NCAM1-deficient mice showed decreased neural invasion and less paralysis. Such Schwann cell behavior reflects normal Schwann cell programs that are typically activated in nerve repair but are instead exploited by cancer cells to promote perineural invasion and cancer progression. PMID:26999607

  2. Th1 and Th17 Cells Induce Proliferative Glomerulonephritis

    PubMed Central

    Summers, Shaun A.; Steinmetz, Oliver M.; Li, Ming; Kausman, Joshua Y.; Semple, Timothy; Edgtton, Kristy L.; Borza, Dorin-Bogdan; Braley, Hal; Holdsworth, Stephen R.

    2009-01-01

    Th1 effector CD4+ cells contribute to the pathogenesis of proliferative and crescentic glomerulonephritis, but whether effector Th17 cells also contribute is unknown. We compared the involvement of Th1 and Th17 cells in a mouse model of antigen-specific glomerulonephritis in which effector CD4+ cells are the only components of adaptive immunity that induce injury. We planted the antigen ovalbumin on the glomerular basement membrane of Rag1−/− mice using an ovalbumin-conjugated non-nephritogenic IgG1 monoclonal antibody against α3(IV) collagen. Subsequent injection of either Th1- or Th17-polarized ovalbumin-specific CD4+ effector cells induced proliferative glomerulonephritis. Mice injected with Th1 cells developed progressive albuminuria over 21 d, histologic injury including 5.5 ± 0.9% crescent formation/segmental necrosis, elevated urinary nitrate, and increased renal NOS2, CCL2, and CCL5 mRNA. Mice injected with Th17 cells developed albuminuria by 3 d; compared with Th1-injected mice, their glomeruli contained more neutrophils and greater expression of renal CXCL1 mRNA. In conclusion, Th1 and Th17 effector cells can induce glomerular injury. Understanding how these two subsets mediate proliferative forms of glomerulonephritis may lead to targeted therapies. PMID:19820122

  3. Th1 and Th17 cells induce proliferative glomerulonephritis.

    PubMed

    Summers, Shaun A; Steinmetz, Oliver M; Li, Ming; Kausman, Joshua Y; Semple, Timothy; Edgtton, Kristy L; Borza, Dorin-Bogdan; Braley, Hal; Holdsworth, Stephen R; Kitching, A Richard

    2009-12-01

    Th1 effector CD4+ cells contribute to the pathogenesis of proliferative and crescentic glomerulonephritis, but whether effector Th17 cells also contribute is unknown. We compared the involvement of Th1 and Th17 cells in a mouse model of antigen-specific glomerulonephritis in which effector CD4+ cells are the only components of adaptive immunity that induce injury. We planted the antigen ovalbumin on the glomerular basement membrane of Rag1(-/-) mice using an ovalbumin-conjugated non-nephritogenic IgG1 monoclonal antibody against alpha3(IV) collagen. Subsequent injection of either Th1- or Th17-polarized ovalbumin-specific CD4+ effector cells induced proliferative glomerulonephritis. Mice injected with Th1 cells developed progressive albuminuria over 21 d, histologic injury including 5.5 +/- 0.9% crescent formation/segmental necrosis, elevated urinary nitrate, and increased renal NOS2, CCL2, and CCL5 mRNA. Mice injected with Th17 cells developed albuminuria by 3 d; compared with Th1-injected mice, their glomeruli contained more neutrophils and greater expression of renal CXCL1 mRNA. In conclusion, Th1 and Th17 effector cells can induce glomerular injury. Understanding how these two subsets mediate proliferative forms of glomerulonephritis may lead to targeted therapies. PMID:19820122

  4. Direct hepatic differentiation of mouse embryonic stem cells induced by valproic acid and cytokines

    PubMed Central

    Dong, Xue-Jun; Zhang, Guo-Rong; Zhou, Qing-Jun; Pan, Ruo-Lang; Chen, Ye; Xiang, Li-Xin; Shao, Jian-Zhong

    2009-01-01

    AIM: To develop a protocol for direct hepatic lineage differentiation from early developmental progenitors to a population of mature hepatocytes. METHODS: Hepatic progenitor cells and then mature hepatocytes from mouse embryonic stem (ES) cells were obtained in a sequential manner, induced by valproic acid (VPA) and cytokines (hepatocyte growth factor, epidermal growth factor and insulin). Morphological changes of the differentiated cells were examined by phase-contrast microscopy and electron microscopy. Reverse transcription polymerase chain reaction and immunocytochemical analyses were used to evaluate the gene expression profiles of the VPA-induced hepatic progenitors and the hepatic progenitor-derived hepatocytes. Glycogen storage, cytochrome P450 activity, transplantation assay, differentiation of bile duct-like structures and tumorigenic analyses were performed for the functional identification of the differentiated cells. Furthermore, FACS and electron microscopy were used for the analyses of cell cycle profile and apoptosis in VPA-induced hepatic differentiated cells. RESULTS: Based on the combination of VPA and cytokines, mouse ES cells differentiated into a uniform and homogeneous cell population of hepatic progenitor cells and then matured into functional hepatocytes. The progenitor population shared several characteristics with ES cells and hepatic stem/progenitor cells, and represented a novel progenitor cell between ES and hepatic oval cells in embryonic development. The differentiated hepatocytes from progenitor cells shared typical characteristics with mature hepatocytes, including the patterns of gene expression, immunological markers, in vitro hepatocyte functions and in vivo capacity to restore acute-damaged liver function. In addition, the differentiation of hepatic progenitor cells from ES cells was accompanied by significant cell cycle arrest and selective survival of differentiating cells towards hepatic lineages. CONCLUSION: Hepatic cells

  5. Worsening anatomic outcomes following aflibercept for neovascular age-related macular degeneration in eyes previously well controlled with ranibizumab

    PubMed Central

    Nudleman, Eric; Wolfe, Jeremy D; Woodward, Maria A; Yonekawa, Yoshihiro; Williams, George A; Hassan, Tarek S

    2016-01-01

    Purpose Antivascular endothelial growth factor injection is the mainstay of treating neovascular age-related macular degeneration (AMD). Previous studies have shown that switching treatment from ranibizumab to aflibercept led to an improvement in eyes with recalcitrant activity. Herein, we identify a unique subset of patients whose eyes with neovascular AMD were previously well controlled with ranibizumab injections were then worsened after being switched to aflibercept. Methods This is a retrospective interventional case series. Eyes with neovascular AMD, previously well controlled with monthly injections of ranibizumab, which then developed worsening of subretinal fluid after being switched to aflibercept were included. Results A total of 17 eyes were included. All eyes developed increased subretinal fluid when switched from ranibizumab to aflibercept. Fourteen patients were switched back to ranibizumab after a single injection of aflibercept and had subsequent rapid resolution of subretinal fluid. Three patients continued with monthly aflibercept injections for two subsequent months and demonstrated the persistence of the increased subretinal fluid until they were switched back to treatment with ranibizumab at which time the fluid resolved. No eye had persistent decline in visual acuity. Conclusion Switching from intravitreal ranibizumab to aflibercept in eyes with well-controlled neovascular AMD may result in worsening in a subset of patients and resolves when therapy is switched back to ranibizumab. PMID:27354759

  6. The Chinese medicine formula HB01 reduces choroidal neovascularization by regulating the expression of vascular endothelial growth factor

    PubMed Central

    2012-01-01

    Background Choroidal neovascularization (CNV) remains the leading cause of newly acquired blindness in the developed world. Currently anti-vascular endothelial growth factor (VEGF) therapies are broadly used to treat neovascular ocular disorders. Here we demonstrate the effect of a traditional Chinese medicine formula, HB01, on CNV. Methods A rat model of laser-induced CNV was used to investigate the effect of HB01 in vivo. The CNV lesions in the eye were evaluated using fundus fluorescein angiography and visualized/quantified using confocal microscopy. Expression of VEGF in the choroidal and retinal tissues was measured using quantitative real-time PCR and immunohistochemistry. Results We demonstrated that a traditional Chinese Medicine formula, named HB01, significantly reduced neovascularization in a rat CNV model. The effect of HB01 on CNV was comparable to the intravitreal injection of bevacizumab (Avastin). Our results also suggested that HB01 may reduce CNV partially through inhibiting the expression of VEGF. Conclusions These data support HB01 as an alternative therapy for ocular neovascular disorders. PMID:22676316

  7. The cyclooxygenase-2 selective inhibitor, etodolac, but not aspirin reduces neovascularization in a murine ischemic hind limb model.

    PubMed

    Tanaka, Kohei; Yamamoto, Yasutaka; Tsujimoto, Shunsuke; Uozumi, Naonori; Kita, Yoshihiro; Yoshida, Akio; Shimizu, Takao; Hisatome, Ichiro

    2010-02-10

    Cyclooxygenase inhibitors are often prescribed to relieve severe ischemic leg pain in critical ischemic limb patients. Prescription of high doses of aspirin and selective cyclooxygenase-2 inhibitors is reported to increase cardiovascular events through suppression of the vasodilative prostanoid prostaglandin I(2) in endothelium. Here, we evaluated the influence of aspirin and etodolac, a selective cyclooxygenase-2 inhibitor, on neovascularization using a murine ischemia hind limb model. C57BL/6J mice were treated with aspirin or etodolac for twenty-eight days after induction of ischemia. We exploited a concentration of the agents that suppressed cyclooxygenase activity efficiently, especially in prostaglandin I(2) production. Recovery of limb blood perfusion and capillary density in ischemic limbs was significantly suppressed by etodolac treatment when compared to the aspirin treated group and untreated group. Production of 6-keto prostaglandin F(1alpha) and prostaglandin E(2) was lower in the aspirin treated group when compared with the etodolac-treated group. Also, these concentrations were lower in both treatment groups compared with the untreated group. Immunohistochemical analysis suggested cyclooxygenase-2 was expressed in endothelium but not in inflammatory cells in ischemic tissue from the acute to chronic phase. Cyclooxygenase-1 was expressed strongly in inflammatory cells in the acute phase. Furthermore, bone marrow-derived mononuclear cell transplantation improved neovascularization, whereas aspirin and etodolac did not inhibit these effects. Production of arachidonic acid metabolites by transplanted cells was independent of the improvement of neovascularization. In conclusion, cyclooxygenase-2 inhibition reduces ischemia-induced neovascularization. PMID:19879866

  8. Effect of Guibi-Tang, a Traditional Herbal Formula, on Retinal Neovascularization in a Mouse Model of Proliferative Retinopathy

    PubMed Central

    Lee, Yun Mi; Lee, Yu-Ri; Kim, Chan-Sik; Jo, Kyuhyung; Sohn, Eunjin; Kim, Jin Sook; Kim, Junghyun

    2015-01-01

    Ocular pathologic angiogenesis is an important causative risk factor of blindness in retinopathy of prematurity, proliferative diabetic retinopathy, and neovascular macular degeneration. Guibi-tang (GBT) is a frequently used oriental herbal formula in East Asian countries, and is also called Qui-pi-tang in Chinese and Kihi-To in Japanese. In the present study, we investigated the preventive effect of GBT on retinal pathogenic neovascularization in a mouse model of oxygen-induced retinopathy (OIR). C57BL/6 mice were exposed to 75% hyperoxia for five days on postnatal day 7 (P7). The mice were then exposed to room air from P12 to P17 to induce ischemic proliferative retinopathy. GBT (50 or 100 mg/kg/day) was intraperitoneally administered daily for five days (from P12 to P16). On P17, Retinal neovascularization was measured on P17, and the expression levels of 55 angiogenesis-related factors were analyzed using protein arrays. GBT significantly decreased retinal pathogenic angiogenesis in OIR mice, and protein arrays revealed that GBT decreased PAI-1 protein expression levels. Quantitative real-time PCR revealed that GBT reduced vascular endothelial growth factor (VEGF), fibroblast growth factor 2 (FGF2), and plasminogen activator inhibitor 1 (PAI-1) mRNA levels in OIR mice. GBT promotes potent inhibitory activity for retinal neovascularization by decreasing VEGF, FGF2, and PAI-1 levels. PMID:26694358

  9. Conditional HIF-1 induction produces multistage neovascularization with stage-specific sensitivity to VEGFR inhibitors and myeloid cell independence

    PubMed Central

    Oladipupo, Sunday S.; Hu, Song; Santeford, Andrea C.; Yao, Junjie; Kovalski, Joanna R.; Shohet, Ralph V.; Maslov, Konstantin

    2011-01-01

    Neovascularization is a crucial component of tumor growth and ischemia. Although prior work primarily used disease models, delineation of neovascularization in the absence of disease can reveal intrinsic mechanisms of microvessel regulation amenable to manipulation in illness. We created a conditional model of epithelial HIF-1 induction in adult mice (TetON-HIF-1 mice). Longitudinal photoacoustic microscopy (L-PAM) was coincidentally developed for noninvasive, label-free serial imaging of red blood cell-perfused vasculature in the same mouse for weeks to months. TetON-HIF-1 mice evidenced 3 stages of neovascularization: development, maintenance, and transgene-dependent regression. Regression occurred despite extensive and tight pericyte coverage. L-PAM mapped microvascular architecture and quantified volumetric changes in neocapillary morphogenesis, arteriovenous remodeling, and microvessel regression. Developmental stage endothelial proliferation down-regulation was associated with a DNA damage checkpoint consisting of p53, p21, and endothelial γ-H2AX induction. The neovasculature was temporally responsive to VEGFR2 immuno-blockade, with the developmental stage sensitive, and the maintenance stage resistant, to DC101 treatment. L-PAM analysis also pinpointed microvessels ablated or resistant to VEGFR2 immuno-blockade. HIF-1–recruited myeloid cells did not mediate VEGFR2 inhibitor resistance. Thus, HIF-1 neovascularization in the absence of disease is self-regulated via cell autonomous endothelial checkpoints, and resistant to angiogenesis inhibitors independent of myeloid cells. PMID:21307392

  10. Vaccination with a mutated variant of human Vascular Endothelial Growth Factor (VEGF) blocks VEGF-induced retinal neovascularization in a rabbit experimental model.

    PubMed

    Morera, Yanelys; González, Rafael; Lamdan, Humberto; Pérez, Lincidio; González, Yorlandis; Agüero, Judith; Castro, Jorge; Romero, Juan C; Etchegoyen, Ana Yansy; Ayala, Marta; Gavilondo, Jorge V

    2014-05-01

    Vascular Endothelial Growth Factor (VEGF) is a key driver of the neovascularization and vascular permeability that leads to the loss of visual acuity of eye diseases like wet age-related macular degeneration, diabetic macular edema, and retinopathy of premature. Among the several anti-VEGF therapies under investigation for the treatment of neovascular eye diseases, our group has developed the vaccine candidate CIGB-247-V that uses a mutated form of human VEGF as antigen. In this work we evaluated if the vaccine could prevent or attenuate VEGF-induced retinal neovascularization in the course of a rabbit eye neovascularization model, based on direct intravitreal injection of human VEGF. Our experimental findings have shown that anti-VEGF IgG antibodies induced by the vaccine were available in the retina blood circulation, and could neutralize in situ the neovascularization effect of VEGF. CIGB-247-V vaccination proved to effectively reduce retinal neovascularization caused by intravitreal VEGF injection. Altogether, these results open the way for human studies of the vaccine in neovascular eye syndromes, and inform on the potential mechanisms involved in its effect. PMID:24675387