Biology subjects

Natoli, R.

Publications and source records attributed to Natoli, R..

4 recordsLinked to original sources

bioRxiv2025

Forced exercise modulates retinal inflammatory response and regulates miRNA expression to promote retinal neuroprotection during degeneration

BackgroundOur labs have demonstrated exercise is protective in animal models of retinal degeneration (RD). Inflammation drives RD progression, and is regulated by the recruitment and reactivity of glia cells as well as through small non-coding RNAs, microRNAs (miRNAs). Here, we explore the effects of treadmill exercise on the recruitment and reactivity of retinal inflammatory cells within the neural retina and miRNA expression in a light-induced retinal degeneration model (LIRD) that exhibits phenotypes found in patients with RD. MethodsMale 6-week-old BALB/c mice were randomly assigned to either active or inactive groups. Active groups were exercised by treadmill 1 hour a day for two weeks at a speed of 10m/min, meanwhile inactive groups were placed on static treadmills for the same duration. Light induced retinal degeneration (LIRD) was induced during the second week of exercise using light exposure of 5000 lux, control animals were kept at 50 lux. Retinal function was assessed using electroretinography (ERG) 5 days after LIRD. Retinas were collected 1-day and 5-days post-LIRD, sagittal sections were stained for inflammatory markers (GFAP and Iba1), TUNEL (cell death), and photoreceptor nuclei (outer nuclear layer; ONL) were quantified. RNA was extracted and miRNA expression quantified with GeneChip miRNA 4.0 array. ResultsActive+LIRD mice demonstrated significant preservation of retinal function, evidenced by higher a-wave and b-wave amplitudes in ERG 5-days post-LIRD, compared to inactive+LIRD mice. Retinal sections from active+LIRD mice had fewer Iba1+ cells and decreased GFAP labeling 5-days post-LIRD compared to inactive+LIRD mice. Active+LIRD mice had fewer ONL TUNEL+ cells compared to inactive+LIRD mice. Inactive+LIRD mice showed a decline in ONL counts 1-day post-LIRD with significant loss 5-days post-LIRD compared to active+LIRD mice. In active groups, exercise promoted significant differences in miRNA expression, such as miR-302b, miR-192-5p, miR-187 compared to inactive groups. ConclusionsOur results indicate that treadmill exercise preserved photoreceptor density, slowed and or prevented apoptosis in the ONL, and decreased the presence/recruitment of inflammatory cells in the neural retina. Altered miRNA expression profiles in active groups are associated with cell survival (miR-302b), oxidative stress regulation (miR-192-5p) and photoreceptor homeostasis (miR-187). These results reveal how exercise alters the retinal inflammatory response over the course of 1-day to 5-days, providing insight into exercise-based therapies and treatments for RD and neuroinflammatory diseases.

neuroscience↗

bioRxiv2024

Therapeutic potential of red blood cell-derived extracellular vesicles in reducing neuroinflammation and protecting against retinal degeneration.

Neuroinflammation is a pathological process mediated through immune cell activation and pro-inflammatory cytokine release, resulting in neuronal cell death. In the central nervous system (CNS), neuroinflammation is a characteristic feature underlying the onset and progression of retinal and neurodegenerative diseases. Targeting neuroinflammation to reduce neuronal cell death and protect against visual and cognitive declines is therefore a key therapeutic strategy. However, due to the complex and multi-faceted nature of these diseases, to date there has been little therapeutic success with single target approaches insufficient to tackle widespread and multi-pathway inflammatory cascades. Furthermore, as the retina and brain reside within immune-privileged environments, a major challenge in treating these diseases is producing and delivering a therapeutic that, in itself, does not exacerbate inflammation. Extracellular vesicles (EV), derived from red blood cells (RBC EV), present a promising solution to overcome these hurdles, due to their innate ability to cross blood-tissue barriers, biocompatible nature, and their broad anti-inflammatory properties to modulate complex neuroinflammatory pathways. This study therefore investigated the therapeutic potential of RBC EV in mediating neuroinflammation using an in-vivo photo-oxidative damage model of retinal degeneration as a model for CNS neuroinflammation. In this work, we developed a novel incubation pipeline using N1 medium supplement and superoxide dismutase (SOD) supplementation to promote the production of safe, neuroprotective, and anti-inflammatory RBC EV. Delivery of RBC EV in vivo, was shown to be safe with strong penetration across all retinal layers. Further, therapeutic administration of RBC EV via local intravitreal injection significantly reduced inflammation and cell death and preserved retinal function. Notably, strong safety and therapeutic efficacy was also demonstrated in the retina following systemic (intraperitoneal) administration, highlighting a potential game-changing approach for less-invasive therapeutic delivery to the CNS. Finally, multi-omic analyses and in vitro findings supported an anti-inflammatory mechanism-of-action, with RBC EV modulating pro-inflammatory cytokine release, including those known to be involved in the pathogenesis of retinal and neurodegenerative diseases. Taken together, these findings highlight the broad applicability of RBC EV in treating neuroinflammation in the CNS, presenting a scalable and effective treatment approach for these currently untreatable diseases.

neuroscience↗

bioRxiv2020

Functional microRNA targetome undergoes degeneration-induced shift in the retina

MicroRNA (miRNA) play a significant role in the pathogenesis of complex neurodegenerative diseases, including age-related macular degeneration, acting as post-transcriptional gene suppressors through their association with argonaute (AGO) protein family members. However, to understand their role in disease, investigation into the regulatory nature of miRNA with their targets is required. To identify the active-miRnome-targetome interactions in the degenerating retina, AGO2 HITS-CLIP was performed using a mouse model of retinal degeneration. Analysis revealed a similar miRnome between healthy and damaged retinas, however, a shift in the active targetome was observed. This shift was also demonstrated by a change in the seed binding regions of miR-124-3p, the most abundant retinal miRNA loaded in AGO2. Following damage, AGO2 was localised to the inner retinal layers indicating a locational miRNA response to retinal damage. This study provides important insight into the alteration of miRNA regulatory activity that occurs as a response to retinal degeneration.

molecular biology↗

bioRxiv2018

Dynamic interplay of innate and adaptive immunity during sterile retinal inflammation: Insights from the transcriptome

The pathogenesis of many retinal degenerations, such as age-related macular degeneration (AMD), is punctuated by an ill-defined network of sterile inflammatory responses. The delineation of innate and adaptive immune milieu amongst the broad leukocyte infiltrate, and the gene networks which construct these responses, are poorly described in the eye. Using photo-oxidative damage in a rodent model of subretinal inflammation, we employed a novel RNA-sequencing framework to map the global gene network signature of retinal leukocytes. This revealed a previously uncharted interplay of adaptive immunity during subretinal inflammation, including prolonged enrichment of myeloid and lymphocyte migration, antigen presentation, and the alternative arm of the complement cascade involving Factor B. We demonstrate Factor B-deficient mice are protected against macrophage infiltration and subretinal inflammation. Suppressing the drivers of retinal leukocyte proliferation, or their capacity to elicit complement responses, may help preserve retinal structure and function during sterile inflammation in diseases such as AMD.

neuroscience↗