RESUMO
Neovascularization is a key feature of ischemic retinal diseases and the wet form of age-related macular degeneration (AMD), all leading causes of severe vision loss. Vascular endothelial growth factor (VEGF) inhibitors have transformed the treatment of these disorders. Millions of patients have been treated with these drugs worldwide. However, in real-life clinical settings, many patients do not experience the same degree of benefit observed in clinical trials, in part because they receive fewer anti-VEGF injections. Therefore, there is an urgent need to discover and identify novel long-acting VEGF inhibitors. We hypothesized that binding to heparan-sulfate proteoglycans (HSPG) in the vitreous, and possibly other ocular structures, may be a strategy to promote intraocular retention, ultimately leading to a reduced burden of intravitreal injections. We designed a series of VEGF receptor 1 variants and identified some with strong heparin-binding characteristics and ability to bind to vitreous matrix. Our data indicate that some of our variants have longer duration and greater efficacy in animal models of intraocular neovascularization than current standard of care. Our study represents a systematic attempt to exploit the functional diversity associated with heparin affinity of a VEGF receptor.
Assuntos
Neovascularização de Coroide/tratamento farmacológico , Proteoglicanas de Heparan Sulfato/farmacologia , Degeneração Macular/tratamento farmacológico , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Inibidores da Angiogênese/química , Animais , Proliferação de Células/efeitos dos fármacos , Neovascularização de Coroide/genética , Neovascularização de Coroide/patologia , Cristalografia por Raios X , Células Endoteliais/efeitos dos fármacos , Olho/efeitos dos fármacos , Olho/patologia , Proteoglicanas de Heparan Sulfato/genética , Proteoglicanas de Heparan Sulfato/imunologia , Heparina/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Fragmentos Fc das Imunoglobulinas/farmacologia , Fragmentos Fc das Imunoglobulinas/ultraestrutura , Injeções Intravítreas , Degeneração Macular/genética , Degeneração Macular/patologia , Camundongos , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/ultraestrutura , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Corpo Vítreo/efeitos dos fármacosRESUMO
The blood vessels in the central nervous system (CNS) have a series of unique properties, termed the blood-brain barrier (BBB), which stringently regulate the entry of molecules into the brain, thus maintaining proper brain homeostasis. We sought to understand whether neuronal activity could regulate BBB properties. Using both chemogenetics and a volitional behavior paradigm, we identified a core set of brain endothelial genes whose expression is regulated by neuronal activity. In particular, neuronal activity regulates BBB efflux transporter expression and function, which is critical for excluding many small lipophilic molecules from the brain parenchyma. Furthermore, we found that neuronal activity regulates the expression of circadian clock genes within brain endothelial cells, which in turn mediate the activity-dependent control of BBB efflux transport. These results have important clinical implications for CNS drug delivery and clearance of CNS waste products, including Aß, and for understanding how neuronal activity can modulate diurnal processes.