IGF-1, Inflammation and Retinal Degeneration: A Close Network

Abstract

Retinal degenerative diseases are a group of heterogeneous diseases that include age-related macular degeneration (AMD), retinitis pigmentosa (RP), and diabetic retinopathy (DR). The progressive degeneration of the retinal neurons results in a severe deterioration of the visual function. Neuroinflammation is an early hallmark of many neurodegenerative disorders of the retina including AMD, RP and DR. Microglial cells, key components of the retinal immune defense system, are activated in retinal degenerative diseases. In the microglia the interplay between the proinflammatory/classically activated or antiinflammatory/alternatively activated phenotypes is a complex dynamic process that occurs during the course of disease due to the different environmental signals related to pathophysiological conditions. In this regard, an adequate transition from the proinflammatory to the anti-inflammatory response is necessary to counteract retinal neurodegeneration and its subsequent damage that leads to the loss of visual function. Insulin like-growth factor-1 (IGF-1) has been considered as a pleiotropic factor in the retina under health or disease conditions and several effects of IGF-1 in retinal immune modulation have been described. In this review, we provide recent insights of inflammation as a common feature of retinal diseases (AMD, RP and RD) highlighting the role of microglia, exosomes and IGF-1 in this process.

Activated microglia-induced neuroinflammatory cytokines lead to photoreceptor apoptosis in age-related macular degeneration-like mice model

“…Since neuroin ammation is a remarkable feature involved in the early phase of AMD procession [29], both in vivo and in vitro, the alterations in neuroin ammatory cytokine expression pro les were similar ( Figure 2D, Figure 3C-F) in our study, the increased in ammatory cytokines like IL-1β and COX-2 were coincided with the published ones. Combining the ultrastructure and functional deterioration in our study, the Aβ induced subretinal injection mice model may generally be used to as an early AMD mice model in further research.…”

Neuroinflammation in Primary Open-Angle Glaucoma

“…Reactive gliosis is, therefore, the mechanism involved in the neuroinflammatory response which underlies the glaucoma pathogenesis. Depending on the nature of the injury and the micro-environment at the injured site, together with the timing and the distance to the injured site [ 337 ], reactive astroglial cells can produce molecules, either with a neuroprotective role, such as IGF1 and the early induction of TNFα [ 338 , 339 ] or harmful molecules, such as inducible nitric oxide synthase (NOS-2), a powerful enzyme related to post-ischemic brain injury that generates excessive amounts of nitric oxide (NO) and the longer-term expression of TNFα [ 338 , 340 ].…”

Activated microglia-induced neuroinflammatory cytokines lead to photoreceptor apoptosis in age-related macular degeneration-like mice model

“…Since neuroinflammation is a remarkable feature involved in the early phase of AMD procession [29], both in vivo and in vitro, the alterations in neuroinflammatory cytokine expression profiles were similar (Fig. 2D, Fig.…”