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The development of treatments targeting the vascular endothelial growth factor (VEGF) signaling pathways have traditionally been firstly investigated in oncology and then advanced into retinal disease indications. Members of the VEGF family of endogenous ligands and their respective receptors play a central role in vasculogenesis and angiogenesis during both development and physiological homeostasis. They can also play a pathogenic role in cancer and retinal diseases. Therapeutic approaches have mostly focused on targeting VEGF-A signaling; however, research has shown that VEGF-C and VEGF-D signaling pathways are also important to the disease pathogenesis of tumors and retinal diseases. This review highlights the important therapeutic advances and the remaining unmet need for improved therapies targeting additional mechanisms beyond VEGF-A. Additionally, it provides an overview of alternative VEGF-C and VEGF-D signaling involvement in both health and disease, highlighting their key contributions in the multifactorial pathophysiology of retinal disease including neovascular age-related macular degeneration (nAMD). Strategies for targeting VEGF-C/-D signaling pathways will also be reviewed, with an emphasis on agents currently being developed for the treatment of nAMD.
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This study evaluated the effectiveness of different recruitment messages for encouraging enrollment in a digital mental health intervention (DMHI) for anxiety among 1,600 anxious patients in a large healthcare system. Patients were randomly assigned to receive a standard message, or one of five messages designed to encourage enrollment: Three messages offered varying financial incentives, one message offered coaching, and one message provided consumer testimonials. Patients could then click a link in the message to visit the DMHI website, enroll, and start the first session. We examined the effects of message features and message length (short vs. long) on rates of site clicks, enrollment, and starting the first session. We also tested whether demographic and clinical factors derived from patients' electronic health records were associated with rates of enrollment and starting the first session to understand the characteristics of patients most likely to use DMHIs in this setting. Across messages, 19.4% of patients clicked a link to visit the DMHI website, but none of the messages were significantly associated with rates of site clicks, enrollment, or starting the first session. Females (vs. males) had a greater probability of enrollment. No other demographic or clinical variables were significantly associated with enrollment or starting the first session. Findings provide guidance for resource allocation decisions in larger scale DMHI implementations in healthcare settings.
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PURPOSE: Neovascular (wet) age-related macular degeneration (nAMD) is driven by VEGFs A, C, and D, which promote angiogenesis and vascular permeability. Intravitreal injections of anti-VEGF-A drugs are the standard of care, but these do not inhibit VEGF-C and D, which may explain why many patients fail to respond fully. This trial aimed to test the safety and efficacy of OPT-302, a biologic inhibitor of VEGF-C and D, in combination with the anti-VEGF-A inhibitor ranibizumab. DESIGN: Dose-ranging, phase 2b, randomized, double-masked, sham-controlled trial. PARTICIPANTS: Participants with treatment-naive nAMD were enrolled from 109 sites across Europe, Israel, and the United States. METHODS: Participants were randomized to 6, 4-weekly, intravitreal injections of 0.5 mg OPT-302, 2.0 mg OPT-302, or sham, plus intravitreal 0.5 mg ranibizumab. MAIN OUTCOME MEASURES: The primary outcome was mean change in ETDRS best-corrected visual acuity (BCVA) at 24 weeks. Secondary outcomes (comparing baseline with week 24) were the proportion of participants gaining or losing ≥ 15 ETDRS BCVA letters; area under the ETDRS BCVA over time curve; change in spectral-domain OCT (SD-OCT) central subfield thickness; and change in intraretinal fluid and subretinal fluid on SD-OCT. RESULTS: Of 366 participants recruited from December 1, 2017, to November 30, 2018, 122, 123, and 121 were randomized to 0.5 mg OPT-302, 2.0 mg OPT-302, and sham, respectively. Mean (± standard deviation) visual acuity gain in the 2.0 mg OPT-302 group was significantly superior to sham (+14.2 ± 11.61 vs. +10.8 ± 11.52 letters; P = 0.01). The 0.5 mg OPT-302 group was not significantly different than the sham group (+9.44 ± 11.32 letters; P = 0.83). Compared with sham, the secondary BCVA outcomes favored the 2.0 mg OPT-302 group, with structural outcomes favoring both OPT-302 dosage groups. Adverse events (AEs) were similar across groups, with 16 (13.3%), 7 (5.6%), and 10 (8.3%) participants in the lower-dose, higher-dose, and sham groups, respectively, developing at least 1 serious AE. Two unrelated deaths both occurred in the sham arm. CONCLUSIONS: Significantly superior vision gain was observed with OPT-302 2.0 mg combination therapy, versus standard of care, with favorable safety (ClinicalTrials.gov identifier: NCT03345082). FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.
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Ranibizumab , Degeneração Macular Exsudativa , Humanos , Ranibizumab/uso terapêutico , Fator C de Crescimento do Endotélio Vascular/uso terapêutico , Anticorpos Monoclonais Humanizados/efeitos adversos , Fator A de Crescimento do Endotélio Vascular , Inibidores da Angiogênese , Degeneração Macular Exsudativa/diagnóstico , Degeneração Macular Exsudativa/tratamento farmacológico , Degeneração Macular Exsudativa/induzido quimicamente , Injeções Intravítreas , Resultado do TratamentoRESUMO
CONTEXT: Despite the massive scale of COVID-19 case investigation and contact tracing (CI/CT) programs operating worldwide, the evidence supporting the intervention's public health impact is limited. OBJECTIVE: To evaluate the Public Health-Seattle & King County (PHSKC) CI/CT program, including its reach, timeliness, effect on isolation and quarantine (I&Q) adherence, and potential to mitigate pandemic-related hardships. DESIGN: This program evaluation used descriptive statistics to analyze surveillance records, case and contact interviews, referral records, and survey data provided by a sample of cases who had recently ended isolation. SETTING: The PHSKC is one of the largest governmental local health departments in the United States. It serves more than 2.2 million people who reside in Seattle and 38 other municipalities. PARTICIPANTS: King County residents who were diagnosed with COVID-19 between July 2020 and June 2021. INTERVENTION: The PHSKC integrated COVID-19 CI/CT with prevention education and service provision. RESULTS: The PHSKC CI/CT team interviewed 42 900 cases (82% of cases eligible for CI/CT), a mean of 6.1 days after symptom onset and 3.4 days after SARS-CoV-2 testing. Cases disclosed the names and addresses of 10 817 unique worksites (mean = 0.8/interview) and 11 432 other recently visited locations (mean = 0.5/interview) and provided contact information for 62 987 household members (mean = 2.7/interview) and 14 398 nonhousehold contacts (mean = 0.3/interview). The CI/CT team helped arrange COVID-19 testing for 5650 contacts, facilitated grocery delivery for 7253 households, and referred 9127 households for financial assistance. End of I&Q Survey participants (n = 304, 54% of sampled) reported self-notifying an average of 4 nonhousehold contacts and 69% agreed that the information and referrals provided by the CI/CT team helped them stay in isolation. CONCLUSIONS: In the 12-month evaluation period, CI/CT reached 42 611 households and identified thousands of exposure venues. The timing of CI/CT relative to infectiousness and difficulty eliciting nonhousehold contacts may have attenuated the intervention's effect. Through promotion of I&Q guidance and services, CI/CT can help mitigate pandemic-related hardships.
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COVID-19 , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/prevenção & controle , Teste para COVID-19 , Busca de Comunicante , Humanos , SARS-CoV-2 , Estados Unidos , Washington/epidemiologiaAssuntos
Portais do Paciente , Idoso , Cuidadores , Comunicação , Morte , Humanos , Participação do PacienteRESUMO
Background: There are few studies examining the usage and utility of patient portals among seriously ill and end-of-life populations and their caregivers. Objective: The aim of this study was to describe portal user characteristics among patients and their caregivers (proxy login) at two time points: (1) the 12 months following an electronic medical record flag for serious illness and (2) during the last 12 months of life. Methods: A retrospective cohort analysis of Kaiser Permanente Colorado (KPCO) patients with serious illness, as defined by Kaiser Permanente's prognostic algorithm, and their proxy caregivers was performed for the two time periods. Use was characterized as (1) the discrete number of days the portal was used and (2) the number of days that portal features were accessed. Differences in use by user characteristics were assessed. Results: Patients flagged for serious illness (N = 6129) were 70.4 ± 14.2 years of age, and used the portal on average 50.4 days. Patients (N = 6517) in the last year of life were 76.7 ± 13.7 years of age and used the portal on average 43 days. Caregiver proxy use of the portal was low in both cohorts. Patients who were older, female, non-White, and healthier were less likely to use the portal. Conclusions: In comparison with overall KPCO portal use and recent patient portal studies examining use patterns, patient portal use was high among patients flagged with serious illness and nearing the end of life. However, because use was associated with age, gender, and race, addressing barriers to portal adoption among underserved populations and caregiver proxies is key to better leveraging patient portal systems for palliative and end-of-life care.
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Portais do Paciente , Cuidadores , Morte , Registros Eletrônicos de Saúde , Feminino , Humanos , Procurador , Estudos RetrospectivosRESUMO
Interactive voice response and text message (IVR-T) technology may improve hypertension control in under-resourced settings. We conducted a randomized clinical trial to determine whether an IVR-T intervention would improve blood pressure (BP), medication adherence and visit keeping among adults with hypertension from multiple racial and ethnic groups in primary care at an Urban Indian Health Organization in Albuquerque, New Mexico. Two hundred and ninety-five participants were randomly assigned to IVR-T (N = 148) or to usual care (N = 147). The IVR-T arm received reminders for clinic visits, messages to reschedule missed clinic visits, monthly medication refill reminders, weekly motivational messages, and a blood pressure cuff. The usual care arm received no messages. The primary outcome was change in systolic BP (SBP) between baseline and 12 months. Secondary outcomes included change in SBP between baseline and 6 months, change in diastolic BP (DBP) at 6 and 12 months, self-reported adherence at 6 months, and the proportion of missed primary care clinic appointments. The intervention did not affect SBP or DBP at 6 or 12 months. The 12-month change in SBP/DBP was 1.66/1.10 mm Hg in usual care and 0.23/1.34 mm Hg in the intervention group (P values = .57 and .88, respectively). Self-reported medication adherence improved comparably in both groups, and there was no difference in percentage of kept visits. Several features of study design, clinic operations, and data transfer were barriers to demonstrating effectiveness.
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Hipertensão , Envio de Mensagens de Texto , Adulto , Pressão Sanguínea , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Adesão à Medicação , Atenção Primária à SaúdeRESUMO
PURPOSE: OPT-302 is a novel inhibitor of vascular endothelial growth factor (VEGF)-C and VEGF-D. A phase 1 trial assessed the safety of intravitreal OPT-302 as monotherapy or combined with ranibizumab (Lucentis; Genentech, South San Francisco, CA) in patients with neovascular age-related macular degeneration (nAMD). DESIGN: Open-label, dose escalation followed by a randomized dose expansion. PARTICIPANTS: Fifty-one patients with nAMD who were either treatment naïve (n = 25) or previously were treated with anti-VEGF A therapy (n = 26). METHODS: In the dose escalation, groups of 5 patients in 4 cohorts received ascending doses of OPT-302 (0.3 mg, 1 mg, or 2 mg) in combination with ranibizumab (0.5 mg), or as monotherapy (2 mg). In the dose expansion, 31 patients were randomized (3:1) to OPT-302 (2 mg) in combination with ranibizumab (n = 23) or as monotherapy (n = 8). Participants received three intravitreal treatments of OPT-302 once every 4 weeks either with or without ranibizumab. MAIN OUTCOME MEASURES: Safety and tolerability, OPT-302 pharmacokinetics and immunogenicity, effects on best-corrected visual acuity (BCVA), and anatomic changes. RESULTS: Intravitreal OPT-302 with or without ranibizumab was well tolerated with low systemic exposure, no dose-limiting toxicities and no immunogenicity. In patients receiving OPT-302 monotherapy, 7 of 13 (54%) did not require rescue anti-VEGF-A therapy and the mean change in BCVA from baseline to week 12 was +5.6 letters (range, 0-18 letters). Mean BCVA gains from baseline to week 12 following combination OPT-302 with ranibizumab were +10.8 letters (95% confidence interval [CI], 4-17; n = 18) in treatment-naïve patients and +4.9 letters (95% CI, 3-7; n = 19) in previously treated patients, respectively. Corresponding reductions in mean central subfield thickness at week 12 in both groups were -119 µm (95% CI, -176 to -62 µm) and -54 µm (95% CI, -82 to -26 µm), respectively, whilst 50% of treatment-naïve patients also showed no detectable choroidal neovascularization at week 12 on fluorescein angiography. CONCLUSIONS: Intravitreal OPT-302 inhibition of VEGF-C and -D was well tolerated, and OPT-302 combination therapy may overcome an escape mechanism to VEGF-A suppression in the management of nAMD.
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Inibidores da Angiogênese/administração & dosagem , Fator C de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator D de Crescimento do Endotélio Vascular/antagonistas & inibidores , Degeneração Macular Exsudativa/tratamento farmacológico , Idoso , Feminino , Angiofluoresceinografia/métodos , Seguimentos , Fundo de Olho , Humanos , Macula Lutea/patologia , Masculino , Estudos Prospectivos , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Degeneração Macular Exsudativa/diagnóstico , Degeneração Macular Exsudativa/metabolismoRESUMO
BACKGROUND: Efficient and effective strategies for treating chronic health conditions such as hypertension are particularly needed for under-resourced clinics such as Urban Indian Health Organizations (UIHOs). OBJECTIVE: The objective of the Controlling Blood Pressure Trial is to assess the impact of an interactive voice response and text message (IVR-T) intervention compared with usual care among individuals with hypertension receiving care at a UIHO in Albuquerque, New Mexico. This manuscript presents the baseline characteristics of individuals enrolled in the trial and compares their characteristics with those in the hypertension registry who did not enroll in the trial. METHODS: A hypertension registry developed from the clinic's electronic health record was used for recruitment. Potentially eligible participants were contacted by letter and then by phone. Those who expressed interest completed an in-person baseline visit that included a baseline survey and blood pressure measurement using standardized procedures. Individuals randomized to the intervention group could opt to receive either automated text messages or automated phone calls in either English or Spanish. The messages include reminders of upcoming appointments at First Nations Community HealthSource, requests to reschedule recently missed appointments, monthly reminders to refill medications, and weekly motivational messages to encourage self-care, appointment keeping, and medication taking for hypertension. Individuals in the IVR-T arm could opt to nominate a care partner to also receive notices of upcoming and missed appointments. Individuals in the IVR-T arm were also offered a home blood pressure monitor. Follow-up visits will be conducted at 6 months and 12 months. RESULTS: Over a 9.5-month period from April 2017 to January 2018, 295 participants were enrolled from a recruitment list of 1497 individuals. The enrolled cohort had a mean age of 53 years, was 25.1% (74/295) American Indian or Alaska Native and 51.9% (153/295) Hispanic, and 39.0% (115/295) had a baseline blood pressure greater than or equal to 140/90 mmHg. Overall, the differences between those enrolled in the trial and patients with hypertension who were ineligible, those who could not be reached, or those who chose not to enroll were minimal. Enrolled individuals had a slightly lower blood pressure (129/77 mmHg vs 132/79 mmHg; P=.04 for systolic blood pressure and P=.01 for diastolic blood pressure), were more likely to self-pay for their care (26% vs 10%; P<.001), and had a more recent primary care visit (164 days vs 231 days; P<.001). The enrolled cohort reported a high prevalence of poor health, low socioeconomic status, and high levels of basic material needs. CONCLUSIONS: The Controlling Blood Pressure Trial has successfully enrolled a representative sample of individuals receiving health care at a UIHO. Trial follow-up will conclude in February 2019. TRIAL REGISTRATION: ClinicalTrials.gov NCT03135405; http://clinicaltrials.gov/ct2/show/NCT03135405 (Archived by WebCite http://www.webcitation.org/76H2B4SO6). INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/11794.
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BACKGROUND: Prostate cancer disseminates to regional lymph nodes, however the molecular mechanisms responsible for lymph node metastasis are poorly understood. The vascular endothelial growth factor (VEGF) ligand and receptor family have been implicated in the growth and spread of prostate cancer via activation of the blood vasculature and lymphatic systems. The purpose of this study was to comprehensively examine the expression pattern of VEGF ligands and receptors in the glandular epithelium, stroma, lymphatic vasculature and blood vessels in prostate cancer. METHODS: The localization of VEGF-A, VEGF-C, VEGF-D, VEGF receptor (VEGFR)-1, VEGFR-2, and VEGFR-3 was examined in cancerous and adjacent benign prostate tissue from 52 subjects representing various grades of prostate cancer. RESULTS: Except for VEGFR-2, extensive staining was observed for all ligands and receptors in the prostate specimens. In epithelial cells, VEGF-A and VEGFR-1 expression was higher in tumor tissue compared to benign tissue. VEGF-D and VEGFR-3 expression was significantly higher in benign tissue compared to tumor in the stroma and the endothelium of lymphatic and blood vessels. In addition, the frequency of lymphatic vessels, but not blood vessels, was lower in tumor tissue compared with benign tissue. CONCLUSIONS: These results suggest that activation of VEGFR-1 by VEGF-A within the carcinoma, and activation of lymphatic endothelial cell VEGFR-3 by VEGF-D within the adjacent benign stroma may be important signaling mechanisms involved in the progression and subsequent metastatic spread of prostate cancer. Thus inhibition of these pathways may contribute to therapeutic strategies for the management of prostate cancer.
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Neoplasias da Próstata/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/patologia , Humanos , Imuno-Histoquímica , Linfangiogênese/fisiologia , Metástase Linfática/patologia , Vasos Linfáticos/metabolismo , Vasos Linfáticos/patologia , Masculino , Gradação de Tumores , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Próstata/irrigação sanguínea , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/secundário , Transdução de Sinais/fisiologia , Fator C de Crescimento do Endotélio Vascular/metabolismo , Fator D de Crescimento do Endotélio Vascular/metabolismoRESUMO
Lymphatic metastasis is facilitated by lymphangiogenic growth factors VEGF-C and VEGF-D that are secreted by some primary tumors. We identified regulation of PGDH, the key enzyme in prostaglandin catabolism, in endothelial cells of collecting lymphatics, as a key molecular change during VEGF-D-driven tumor spread. The VEGF-D-dependent regulation of the prostaglandin pathway was supported by the finding that collecting lymphatic vessel dilation and subsequent metastasis were affected by nonsteroidal anti-inflammatory drugs (NSAIDs), known inhibitors of prostaglandin synthesis. Our data suggest a control point for cancer metastasis within the collecting lymphatic endothelium, which links VEGF-D/VEGFR-2/VEGFR-3 and the prostaglandin pathways. Collecting lymphatics therefore play an active and important role in metastasis and may provide a therapeutic target to restrict tumor spread.
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Transformação Celular Neoplásica , Endotélio Linfático/metabolismo , Metástase Linfática/fisiopatologia , Prostaglandinas/metabolismo , Fator D de Crescimento do Endotélio Vascular/fisiologia , Animais , Anti-Inflamatórios/farmacologia , Endotélio Linfático/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Linfangiogênese/efeitos dos fármacos , Metástase Linfática/genética , Sistema Linfático/efeitos dos fármacos , Sistema Linfático/patologia , Vasos Linfáticos/metabolismo , Vasos Linfáticos/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Fator D de Crescimento do Endotélio Vascular/genética , Fator D de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
The vascular endothelial growth factors VEGFA and VEGFC are crucial regulators of vascular development. They exert their effects by dimerization and activation of the cognate receptors VEGFR2 and VEGFR3. Here, we have used in situ proximity ligation to detect receptor complexes in intact endothelial cells. We show that both VEGFA and VEGFC potently induce formation of VEGFR2/-3 heterodimers. Receptor heterodimers were found in both developing blood vessels and immature lymphatic structures in embryoid bodies. We present evidence that heterodimers frequently localize to tip cell filopodia. Interestingly, in the presence of VEGFC, heterodimers were enriched in the leading tip cells as compared with trailing stalk cells of growing sprouts. Neutralization of VEGFR3 to prevent heterodimer formation in response to VEGFA decreased the extent of angiogenic sprouting. We conclude that VEGFR2/-3 heterodimers on angiogenic sprouts induced by VEGFA or VEGFC may serve to positively regulate angiogenic sprouting.
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Células Endoteliais/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator C de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Embrião de Mamíferos/metabolismo , Endotélio Vascular/metabolismo , Humanos , Neovascularização Fisiológica , Multimerização Proteica , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidoresRESUMO
Communities That Care (CTC) is a prevention system designed to reduce adolescent substance use and delinquency through the selection of effective preventive interventions tailored to a community's specific profile of risk and protection. A community-randomized trial of CTC, the Community Youth Development Study, is currently being conducted in 24 communities across the United States. This article describes the rationale, multilevel analyses, and baseline comparability for the study's longitudinal cohort design. The cohort sample consists of 4,407 fifth- and sixth-grade students recruited in 2004 and 2005 and surveyed annually through ninth grade. Results of mixed-model ANOVAs indicated that students in CTC and control communities exhibited no significant differences (ps > .05) in baseline levels of student outcomes.
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Delinquência Juvenil/prevenção & controle , Transtornos Relacionados ao Uso de Substâncias/prevenção & controle , Adolescente , Serviços de Saúde do Adolescente , Serviços de Saúde Comunitária , Redes Comunitárias , Promoção da Saúde/organização & administração , Humanos , Modelos Lineares , Estudos Longitudinais , Seleção de Pacientes , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Estados UnidosRESUMO
Lymphatic vessels play an important role in the regulation of tissue fluid balance, immune responses, and fat adsorption and are involved in diseases including lymphedema and tumor metastasis. Vascular endothelial growth factor (VEGF) receptor 3 (VEGFR-3) is necessary for development of the blood vasculature during early embryogenesis, but later, VEGFR-3 expression becomes restricted to the lymphatic vasculature. We analyzed mice deficient in both of the known VEGFR-3 ligands, VEGF-C and VEGF-D. Unlike the Vegfr3(-/-) embryos, the Vegfc(-/-); Vegfd(-/-) embryos displayed normal blood vasculature after embryonic day 9.5. Deletion of Vegfr3 in the epiblast, using keratin 19 (K19) Cre, resulted in a phenotype identical to that of the Vegfr3(-/-) embryos, suggesting that this phenotype is due to defects in the embryo proper and not in placental development. Interestingly, the Vegfr3(neo) hypomorphic mutant mice carrying the neomycin cassette between exons 1 and 2 showed defective lymphatic development. Overexpression of human or mouse VEGF-D in the skin, under the K14 promoter, rescued the lymphatic hypoplasia of the Vegfc(+/-) mice in the K14-VEGF-D; Vegfc(+/-) compound mice, suggesting that VEGF-D is functionally redundant with VEGF-C in the stimulation of developmental lymphangiogenesis. Our results suggest VEGF-C- and VEGF-D-independent functions for VEGFR-3 in the early embryo.
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Embrião de Mamíferos/metabolismo , Deleção de Genes , Fator C de Crescimento do Endotélio Vascular/deficiência , Fator D de Crescimento do Endotélio Vascular/deficiência , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/deficiência , Alelos , Animais , Vasos Sanguíneos/embriologia , Embrião de Mamíferos/anormalidades , Embrião de Mamíferos/patologia , Marcação de Genes , Linfangiogênese , Vasos Linfáticos/anormalidades , Vasos Linfáticos/embriologia , Vasos Linfáticos/patologia , Camundongos , Camundongos Knockout , FenótipoRESUMO
Vascular endothelial growth factor (VEGF) is an essential regulator of normal and abnormal blood vessel growth. A monoclonal antibody (mAb) that targets VEGF suppresses tumor growth in murine cancer models and human patients. We investigated cellular and molecular events that mediate refractoriness of tumors to anti-angiogenic therapy. Inherent anti-VEGF refractoriness is associated with infiltration of the tumor tissue by CD11b+Gr1+ myeloid cells. Recruitment of these myeloid cells is also sufficient to confer refractoriness. Combining anti-VEGF treatment with a mAb that targets myeloid cells inhibits growth of refractory tumors more effectively than anti-VEGF alone. Gene expression analysis in CD11b+Gr1+ cells isolated from the bone marrow of mice bearing refractory tumors reveals higher expression of a distinct set of genes known to be implicated in active mobilization and recruitment of myeloid cells. These findings indicate that, in our models, refractoriness to anti-VEGF treatment is determined by the ability of tumors to prime and recruit CD11b+Gr1+ cells.
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Antineoplásicos/administração & dosagem , Antígeno CD11b/metabolismo , Leucemia Mieloide/tratamento farmacológico , Leucemia Mieloide/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Receptores de Quimiocinas/metabolismo , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Camundongos , Camundongos Endogâmicos C57BL , Resultado do TratamentoRESUMO
The lymphatic network functions to return fluid, cells and macromolecules to the circulation. Recent characterization of growth factors that control the growth and development of the lymphatics, and markers which specify lymphatic endothelial cells have enhanced our understanding of this system. Members of the VEGF family of factors are key regulators of these vessels with VEGF-C/VEGF-D and VEGFR-3 being the best validated signalling pathways in lymphangiogenesis. The study of these molecules in various pathologies has shown that they are important in the processes of cancer metastasis and in the formation of lymphoedema. Knowledge of these molecular pathways allows for the generation of modulators of these pathways which could form the basis of novel therapeutic approaches.
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Linfangiogênese/fisiologia , Neoplasias/metabolismo , Transdução de Sinais/fisiologia , Fatores de Crescimento do Endotélio Vascular/metabolismo , Humanos , Linfangiogênese/genética , Transdução de Sinais/genéticaRESUMO
Corneal avascularity-the absence of blood vessels in the cornea-is required for optical clarity and optimal vision, and has led to the cornea being widely used for validating pro- and anti-angiogenic therapeutic strategies for many disorders. But the molecular underpinnings of the avascular phenotype have until now remained obscure and are all the more remarkable given the presence in the cornea of vascular endothelial growth factor (VEGF)-A, a potent stimulator of angiogenesis, and the proximity of the cornea to vascularized tissues. Here we show that the cornea expresses soluble VEGF receptor-1 (sVEGFR-1; also known as sflt-1) and that suppression of this endogenous VEGF-A trap by neutralizing antibodies, RNA interference or Cre-lox-mediated gene disruption abolishes corneal avascularity in mice. The spontaneously vascularized corneas of corn1 and Pax6+/- mice and Pax6+/- patients with aniridia are deficient in sflt-1, and recombinant sflt-1 administration restores corneal avascularity in corn1 and Pax6+/- mice. Manatees, the only known creatures uniformly to have vascularized corneas, do not express sflt-1, whereas the avascular corneas of dugongs, also members of the order Sirenia, elephants, the closest extant terrestrial phylogenetic relatives of manatees, and other marine mammals (dolphins and whales) contain sflt-1, indicating that it has a crucial, evolutionarily conserved role. The recognition that sflt-1 is essential for preserving the avascular ambit of the cornea can rationally guide its use as a platform for angiogenic modulators, supports its use in treating neovascular diseases, and might provide insight into the immunological privilege of the cornea.
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Córnea/irrigação sanguínea , Córnea/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Deleção de Genes , Camundongos , Neovascularização Fisiológica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Solubilidade , Trichechus , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/deficiência , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genéticaRESUMO
Vascular endothelial growth factor-A (VEGF-A) and its 2 transmembrane tyrosine-kinase receptors, VEGFR-1 and VEGFR-2, constitute a ligand-receptor signaling system that is crucial for developmental angiogenesis. VEGF-B and placental growth factor (PlGF) activate VEGFR-1 selectively, however, mice lacking either ligand display only minor developmental defects. We hypothesized that the relative contributions of VEGF-B and PlGF to VEGFR-1 signaling may be masked in the presence of VEGF-A, which is abundantly expressed during postnatal development. To test this hypothesis, neonatal or adult mice were treated with a monoclonal antibody (G6-23-IgG) blocking murine VEGF-A or a soluble VEGFR-1 receptor IgG chimeric construct [mFlt(1-3)-IgG], which neutralizes VEGF-A, VEGF-B, and PlGF. Both compounds attenuated growth and survival of neonatal mice to similar extents and the pathophysiologic alterations, including a reduction in organ size and vascularization, changes in gene expression, and hematologic end points, were essentially indistinguishable. In adult mice, we observed only minor changes in response to treatment, which were similar between both anti-VEGF compounds. In conclusion, our findings suggest that PlGF and VEGF-B do not compensate during conditions of VEGF-A blockade, suggesting a minor role for compensatory VEGFR-1 signaling during postnatal development and vascular homeostasis in adults. The absence of compensatory VEGFR-1 signaling by VEGF-B and PlGF may have important implications for the development of anticancer strategies targeting the VEGF ligand/receptor system.
Assuntos
Neoplasias Experimentais/terapia , Neovascularização Patológica , Proteínas da Gravidez/metabolismo , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator B de Crescimento do Endotélio Vascular/metabolismo , Animais , Animais Recém-Nascidos , Anticorpos Monoclonais/farmacologia , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos , Camundongos Mutantes , Camundongos Nus , Neoplasias Experimentais/irrigação sanguínea , Neoplasias Experimentais/metabolismo , Fator de Crescimento Placentário , Proteínas da Gravidez/antagonistas & inibidores , Proteínas da Gravidez/imunologia , Taxa de Sobrevida , Fator A de Crescimento do Endotélio Vascular/imunologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator B de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator B de Crescimento do Endotélio Vascular/imunologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/imunologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Vascular endothelial growth factor receptor 3 (Vegfr-3) is a tyrosine kinase that is expressed on the lymphatic endothelium and that signals for the growth of the lymphatic vessels (lymphangiogenesis). Vegf-d, a secreted glycoprotein, is one of two known activating ligands for Vegfr-3, the other being Vegf-c. Vegf-d stimulates lymphangiogenesis in tissues and tumors; however, its role in embryonic development was previously unknown. Here we report the generation and analysis of mutant mice deficient for Vegf-d. Vegf-d-deficient mice were healthy and fertile, had normal body mass, and displayed no pathologic changes consistent with a defect in lymphatic function. The lungs, sites of strong Vegf-d gene expression during embryogenesis in wild-type mice, were normal in Vegf-d-deficient mice with respect to tissue mass and morphology, except that the abundance of the lymphatics adjacent to bronchioles was slightly reduced. Dye uptake experiments indicated that large lymphatics under the skin were present in normal locations and were functional. Smaller dermal lymphatics were similar in number, location, and function to those in wild-type controls. The lack of a profound lymphatic phenotype in Vegf-d-deficient mice suggests that Vegf-d does not play a major role in lymphatic development or that Vegf-c or another, as-yet-unknown activating Vegfr-3 ligand can compensate for Vegf-d during development.
Assuntos
Endotélio Linfático/citologia , Linfangiogênese/genética , Fator D de Crescimento do Endotélio Vascular/fisiologia , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/fisiologia , Animais , Endotélio Linfático/química , Endotélio Linfático/metabolismo , Marcação de Genes , Pulmão/química , Pulmão/citologia , Pulmão/metabolismo , Linfangiogênese/fisiologia , Camundongos , Camundongos Mutantes , Mutação/genética , Fator D de Crescimento do Endotélio Vascular/genética , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/análiseRESUMO
PURPOSE: The molecular mechanisms underlying lymph node metastasis are poorly understood, despite the well-established clinical importance of lymph node status in many human cancers. Recently, vascular endothelial growth factor (VEGF)-C and VEGF-D have been implicated in the regulation of tumor lymphangiogenesis and enhancement of lymphatic invasion via activation of VEGF receptor-3. The purpose of this study was to determine the expression pattern of the VEGF-C/VEGF-D/VEGF receptor-3 axis in prostate cancer and its relationship with lymph node metastasis. EXPERIMENTAL DESIGN: The expression pattern of VEGF-C, VEGF-D, and VEGF receptor-3 in localized prostate cancer specimens (n = 37) was determined using immunohistochemistry. RESULTS: Widespread, heterogeneous staining for VEGF-C and VEGF-D was observed in all cancer specimens. Intensity of VEGF-C staining was lower in benign prostate epithelium than in adjacent carcinoma, whereas no difference between benign epithelium and carcinoma was observed for VEGF-D staining. VEGF receptor-3 immunostaining was detected in endothelial cells of lymphatic vessels in 18 of 37 tissue samples. The presence of VEGF receptor-3-positive vessels was associated with lymph node metastasis (P = 0.0002), Gleason grade (P < 0.0001), extracapsular extension (P = 0.0382), and surgical margin status (P = 0.0069). In addition, VEGF receptor-3 staining highlighted lymphatic invasion by VEGF-C-positive/VEGF-D-positive carcinoma cells. CONCLUSIONS: Together, these results suggest that paracrine activation of lymphatic endothelial cell VEGF receptor-3 by VEGF-C and/or VEGF-D may be involved in lymphatic metastasis. Thus the VEGF-C/VEGF-D/VEGF receptor-3 signaling pathway may provide a target for antilymphangiogenic therapy in prostate cancer.