Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth

Enhancing Late Retinopathy of Prematurity Outcomes with Fresh Bone Marrow Mononuclear Cells and Melatonin Combination Therapy

INTRODUCTION

Retinopathy of prematurity (ROP) is a vasoproliferative disease affecting premature neonates with life-lasting impacts. This study aims to investigate the long-term functional outcomes and alterations in neural retina architecture following the intravitreal transplantation of bone marrow mononuclear cells (BMMNC) in the rat models of ROP, and to evaluate the effect of adjunctive therapy with melatonin.

METHODS

32 neonate rats were employed. The ROP model was developed in 10 neonatal rats, and two were assigned as control. The ROP models received BMMNC suspension, containing 1.2 × 105 cells, in their right eye, and normal saline in left at p12. Five ROP rats received 12.5 mg/kg melatonin orally for five days (p12 to p17). Optical coherence tomography (OCT) and electroretinography (ERG) were performed on p47. Eyes were then harvested on p47, and after six months for histology, immunofluorescence (anti-calbindin, anti-PKC, and anti-Brn3), and immunohistochemistry (synaptophysin).

RESULTS

Cell therapy alone and with melatonin increased retinal thickness, and improved oscillatory potentials on ERG. Combination therapy increased horizontal and retinal ganglion cell populations. All treatments improved synaptic maturity in the inner plexiform layer, but only combination therapy was effective on the outer plexiform layer.

CONCLUSION

Melatonin and BMMNCs combination therapy effectively ameliorates retinal structural and functional deficits at later ROP stages, without causing severe adverse effects. It significantly increases the survival of post-receptor retinal neurons and preserves retinal synaptic structures in the long term, highlighting the promising potential of this novel combination therapy approach to minimize visual deficits in ROP patients.

4D label-free proteomics analysis of oxygen-induced retinopathy with or without anti-VEGF treatment

Oxygen-induced retinopathy (OIR) animal model is widely used for retinopathy of prematurity (ROP) researches. The purpose of this study was to identify proteins and related pathways of OIR with or without anti-vascular endothelial growth factor (VEGF) treatment, for use as biomarkers in diagnosing and treating ROP. Nine samples were subjected to proteomic analysis. Retina specimens were collected from 3 OIR mice, 3 OIR mice with anti-VEGF treatment and 3 normal mice (control group). Liquid chromatography-tandem mass spectrometry analysis was performed using the 4D label-free technique. Statistically significant differentially expressed proteins, gene ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway representations, InterPro (IPR) and protein interactions were analyzed. In total, 4585 unique proteins were identified as differentially expressed proteins (DEPs). Enrichment analysis of the GO and KEGG indicated functional clusters related to peptide biosynthetic and metabolic process, cellular macromolecule biosynthetic process and nucleic acid binding in OIR group. For anti-VEGF treatment group, DEPs were clustered in DNA replication, PI3K/Akt signaling pathway and Jak/STAT signaling pathway. Proteomic profiling is useful for the exploration of molecular mechanisms of OIR and mechanisms of anti-VEGF treatment. These findings may be useful for identification of novel biomarkers for ROP pathogenesis and treatment.

Retinopathy of Prematurity-Targeting Hypoxic and Redox Signaling Pathways

Retinopathy of prematurity (ROP) is a proliferative vascular ailment affecting the retina. It is the main risk factor for visual impairment and blindness in infants and young children worldwide. If left undiagnosed and untreated, it can progress to retinal detachment and severe visual impairment. Geographical variations in ROP epidemiology have emerged over recent decades, attributable to differing levels of care provided to preterm infants across countries and regions. Our understanding of the causes of ROP, screening, diagnosis, treatment, and associated risk factors continues to advance. This review article aims to present the pathophysiological mechanisms of ROP, including its treatment. Specifically, it delves into the latest cutting-edge treatment approaches targeting hypoxia and redox signaling pathways for this condition.

Silva H, P. de Carvalho R, Ventura ALM, Calaza KC, Silveira MS, Kubrusly RCC, de Melo Reis RA. The Healthy and Diseased Retina Seen through Neuron-Glia Interactions

The retina is the sensory tissue responsible for the first stages of visual processing, with a conserved anatomy and functional architecture among vertebrates. To date, retinal eye diseases, such as diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa, glaucoma, and others, affect nearly 170 million people worldwide, resulting in vision loss and blindness. To tackle retinal disorders, the developing retina has been explored as a versatile model to study intercellular signaling, as it presents a broad neurochemical repertoire that has been approached in the last decades in terms of signaling and diseases. Retina, dissociated and arranged as typical cultures, as mixed or neuron- and glia-enriched, and/or organized as neurospheres and/or as organoids, are valuable to understand both neuronal and glial compartments, which have contributed to revealing roles and mechanisms between transmitter systems as well as antioxidants, trophic factors, and extracellular matrix proteins. Overall, contributions in understanding neurogenesis, tissue development, differentiation, connectivity, plasticity, and cell death are widely described. A complete access to the genome of several vertebrates, as well as the recent transcriptome at the single cell level at different stages of development, also anticipates future advances in providing cues to target blinding diseases or retinal dysfunctions.

MiR-423-5p promotes Müller cell activation via targeting NGF signaling in diabetic retinopathy

AIMS

Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus and one of the major causes of visual impairment and blindness in industrialized countries. The early neuro-glial perturbations, especially retinal Müller cells (rMC) activation, intimately associated with the vascular alterations. MicroRNAs (miRNAs) have been reported to play critical roles in the progression of DR. Here, we aimed to further explore the role and underlying mechanism of miR-423-5p in Müller cell activation in streptozotocin (STZ)-induced diabetic mice and oxygen-induced retinopathy (OIR) model.

MATERIALS AND METHODS

Retinal histology, optical coherence tomography (OCT) and biochemical markers were assessed.

KEY FINDINGS

Our data revealed that the expression of miR-423-5p was significantly increased under high-glucose environment. We also demonstrated that miR-423-5p overexpression markedly accelerated retinal vascular leakage, leukocytosis, and rMC activation. This response was ameliorated in animals pre-treated with the inhibition of miR-423-5p. Specifically, miR-423-5p bound to the nerve growth factor (NGF) 3' UTR region to induce its silencing. NGF inhibition significantly promoted retinal microvascular dysfunction.

SIGNIFICANCE

These findings demonstrate that miR-423-5p is a critical miRNA that promotes microvascular dysfunction in DR.

Latest Trends in Retinopathy of Prematurity: Research on Risk Factors, Diagnostic Methods and Therapies

Retinopathy of prematurity (ROP) is a vasoproliferative disorder with an imminent risk of blindness, in cases where early diagnosis and treatment are not performed. The doctors' constant motivation to give these fragile beings a chance at life with optimal visual acuity has never stopped, since Terry first described this condition. Thus, throughout time, several specific advancements have been made in the management of ROP. Apart from the most known risk factors, this narrative review brings to light the latest research about new potential risk factors, such as: proteinuria, insulin-like growth factor 1 (IGF-1) and blood transfusions. Digital imaging has revolutionized the management of retinal pathologies, and it is more and more used in identifying and staging ROP, particularly in the disadvantaged regions by the means of telescreening. Moreover, optical coherence tomography (OCT) and automated diagnostic tools based on deep learning offer new perspectives on the ROP diagnosis. The new therapeutical trend based on the use of anti-VEGF agents is increasingly used in the treatment of ROP patients, and recent research sustains the theory according to which these agents do not interfere with the neurodevelopment of premature babies.