Human Retinopathy Of Prematurity Research Articles

Hyperoxia‐Induced Preretinal Membrane Formation and Retinal Detachment in the Mouse

BackgroundRetinal detachment (RD) is a vision‐threatening consequence of several conditions including retinopathy of prematurity (ROP). Numerous studies have established the connection of high oxygen concentration altering retinal development in preterm infants, leading to RD and blindness in later stages. The goal of this study was to develop a reproducible, non‐invasive model mouse of human ROP that could be used to study the cellular events leading to the formation of tractional preretinal membranes and RD.HypothesisPlacing C57BL/6J mice in hyperoxic conditions for one week starting at birth will induce a non‐traumatic sequence of retinopathy leading to tractional RD that mimics the pathophysiology of detachment seen in ROP.MethodsC57BL/6J newborn mice were placed into a hyperoxic environment (65% oxygen saturation) for 7 days then reared in ambient air. Retinas were observed at weeks 4, 5, and 7 via spectral‐domain optical coherence tomography (OCT). Eyes were processed for histology and immunostaining for the myofibroblast marker alpha‐smooth muscle actin (α‐SMA).ResultsFour weeks after birth, 100% of mice placed in hyperoxia exhibited retinal blebs, 91% had developed preretinal membranes, and 9% had RD. At 5 weeks, 100% and 27% had preretinal membranes and RD, respectively. At week 7, the number of mice with RD increased to 33%. Preretinal membranes arose at the surface of the retina above the optic nerve head. RD occurred between the neurosensory retina and the underlying retinal pigment epithelium. Myofibroblasts were detected with the antibody to α‐SMA in the preretinal membranes and above areas of RD.ConclusionThe hyperoxia‐induced retinopathy model was confirmed to induce retinal pathology in newborn mouse pups. Retinal pathology progressed during a 7‐week time period (i.e. retinal blebs to preretinal membranes and folds to retinal detachment). This noninvasive model replicates the oxygen‐induced retinopathy seen in human ROP. The model is useful for investigating the origin of cells that contribute to the formation of tractional retinopathy, especially PRMs and RD. The presence of α‐SMA‐positive cells overlying areas of retinopathy suggests the contractile property of myofibroblasts induces tractional RD.

Competing endogenous RNA network associated with oxygen-induced retinopathy: Expression of the network and identification of the MALAT1/miR-124–3p/EGR1 regulatory axis

Retinopathy of prematurity (ROP) is a severe retinal dysfunction in prematurely born babies. The relationship between non-coding RNAs and retinopathy of prematurity (ROP) remain unclear. Microarray analysis of lncRNAs, miRNAs, and mRNAs was conducted in a mouse model of ROP. A competing endogenous RNA (ceRNA) network was constructed. The relationship among MALAT1, miR-124–3p, and Early growth response protein 1 (EGR1) was assessed in hypoxia-induced primary human umbilical vein endothelial cells (HUVECs) and ROP mouse model. In the study, we found 2252 lncRNAs, 1239 mRNAs, and 36 miRNAs were differentially regulated. ceRNA network consisting of 21 lncRNAs, 10 miRNAs, and 19 mRNAs was established. Of the most down-regulated miRNAs, miR-124–3p was selected for additional study. miR-124–3p ceased the migration and proliferation of primary HUVECs in hypoxic conditions, and directly suppressed EGR1. Additionally, MALAT1 directly sponged miR-124–3p. Knockdown of MALAT1 decreased EGR1 expression and inhibited the migration and proliferation of primary HUVECs in hypoxia. Furthermore, these changes were rescued by depletion of miR-124–3p. In vivo, intravitreal injection of miR-124–3p, shMALAT1 decreased EGR1 expression and markedly suppressed retinal neovascularization in OIR models. Intravitreal injection of shMALAT1 and miR-124–3p antagomir at the same time can promote retinal neovascularization, which reversed the suppression of retinal neovascularization functioned by shMALAT1. In conclusion, the expression profiles of lncRNAs and miRNAs and the ceRNA network in a mouse model of ROP may be indicative of the underlying mechanisms of retinal angiogenesis and neural activity. The MALAT1/miR-124–3p/EGR1 regulatory axis is partly responsible for retinal neovascularization, which may provide a novel theoretical basis for the pathogenesis of ROP.

Long-lasting impairments in rodent oxygen-induced retinopathy measured by retinal vessel density and visual function.

In mild or moderate retinopathy of prematurity (ROP), retinal vessels undergo obliteration, proliferation, and regression. Despite complete regression of vessel abnormalities, a variety of visual impairments have been reported. Rodent oxygen-induced retinopathy (OIR) is widely used as a model to study ROP. However, the long-term changes of OIR model remain unclear. The aim of this study is to examine long term changes of retinal vessel and visual function in a rodent OIR model resembling human mild or moderate ROP. In this study, after subjecting the animals to 80% oxygen (O2) for 5-7 d, the retinal vessel density at postnatal day 12 (P12) was approximately 30% lower than that in the age-matched control, but this difference was not significant between the groups. Vessel abnormalities, such as vessel tortuosity, neovascular tufts, and the number of vessels protruding into the vitreous, peaked between P17 and P20. Despite the regression of many abnormalities, vessel density in the OIR group was 36% and 32% lower than that in the control animals at 6 weeks and 4 months, respectively. The visual acuity and contrast sensitivity were impaired in the OIR group when measured at 2, 3 and 4 months. Therefore, the rodent OIR model exhibited long-lasting reduction in retinal vessel density and visual impairments, similar to those observed in mild or moderate human ROP. This study suggests that the rodent OIR model can be used to explore possible interventions for mild and moderate human ROP.

Gene therapy knockdown of VEGFR2 in retinal endothelial cells to treat retinopathy

Inhibition of vascular endothelial growth factor (VEGF) in retinopathy of prematurity (ROP) raises concerns for premature infants because VEGF is essential for retinovascular development as well as neuronal and glial health. This study tested the hypothesis that endothelial cell-specific knockdown of VEGF receptor 2 (VEGFR2), or downstream STAT3, would inhibit VEGF-induced retinopathy without delaying physiologic retinal vascular development. We developed an endothelial cell-specific lentiviral vector that delivered shRNAs to VEGFR2 or STAT3 and a green fluorescent protein reporter under control of the VE-cadherin promoter. The specificity and efficacy of the lentiviral vector-driven shRNAs were validated in vitro and in vivo. In the rat oxygen-induced retinopathy model highly representative of human ROP, the effects of endothelial cell knockdown of VEGFR2 or STAT3 were determined on intravitreal neovascularization (IVNV), physiologic retinal vascular development [assessed as area of peripheral avascular/total retina (AVA)], retinal structure, and retinal function. Targeted knockdown of VEGFR2 or STAT3 specifically in retinal endothelial cells by subretinal injection of lentiviral vectors into postnatal day 8 rat pup eyes efficiently inhibited IVNV, and knockdown of VEGFR2 also reduced AVA and increased retinal thickness without altering retinal function. Taken together, our results support specific knockdown of VEGFR2 in retinal endothelial cells as a novel therapeutic method to treat retinopathy.

The effect of a single anti-Vascular Endothelial Growth Factor injection on neonatal growth and organ development: In-vivo study

Retinopathy of prematurity (ROP) is one of the leading causes of blindness in preterm Infants. Anti-vascular endothelial growth factor (VEGF) is emerging as a promising treatment, but there is insufficient evidence on their safety. We investigate the effect of systemic anti-VEGF in rat pups with equivalent maturity to a 32 week neonate. A single dose of either anti-VEGF antibody (n = 7) or saline (control group; n = 6) was administered to newborn rats intra-peritoneally on the first day of life. 14 days' post treatment, the serum concentration of anti-VEGF was measured and the brain, lung, heart, kidney and liver were harvested and weighed. The heart was processed to measure the Fulton index (a surrogate for pulmonary hypertension). All other organs were processed for mRNA expression of VEGF and VEGF-receptors (R1&R2). No group differences in body and organ weights were noted. The anti-VEGF was still detected in serum 14 days post Injection and resulted in increase in lung (p < 0.002) and kidney (p < 0.01) VEGF mRNA expressions and the lung (p < 0.02) VEGF-R1 and kidney (P < 0.001) VEGF-R2 mRNA expressions. The treated pups exhibited increased total heart weight (p < 0.01) and Fulton Index (p < 0.05). No changes were seen in the liver and brain. Anti-VEGF antibody did not affect mortality, total body and organ weights, but was associated with pulmonary hypertension. Expression of lung and kidney VEGF and its receptors was increased, whilst the brain and liver did not show changes. Dosing experiments can now be targeted to assess safety threshold and at anti-VEGF dose used in human ROP treatment.

Retinal, visual, and refractive development in retinopathy of prematurity.

The pivotal role of the neurosensory retina in retinopathy of prematurity (ROP) disease processes has been amply demonstrated in rat models. We have hypothesized that analogous cellular processes are operative in human ROP and have evaluated these presumptions in a series on non-invasive investigations of the photoreceptor and post-receptor peripheral and central retina in infants and children. Key results are slowed kinetics of phototransduction and deficits in photoreceptor sensitivity that persist years after ROP has completely resolved based on clinical criteria. On the other hand, deficits in post-receptor sensitivity are present in infancy regardless of the severity of the ROP but are not present in older children if the ROP was so mild that it never required treatment and resolved without a clinical trace. Accompanying the persistent deficits in photoreceptor sensitivity, there is increased receptive field size and thickening of the post-receptor retinal laminae in the peripheral retina of ROP subjects. In the late maturing central retina, which mediates visual acuity, attenuation of multifocal electroretinogram activity in the post-receptor retina led us to the discovery of a shallow foveal pit and significant thickening of the post-receptor retinal laminae in the macular region; this is most likely due to failure of the normal centrifugal movement of the post-receptor cells during foveal development. As for refractive development, myopia, at times high, is more common in ROP subjects than in control subjects, in accord with refractive findings in other populations of former preterms. This information about the neurosensory retina enhances understanding of vision in patients with a history of ROP, and taken as a whole, raises the possibility that the neurosensory retina is a target for therapeutic intervention.

Acetyl-11-keto-β-boswellic acid reduces retinal angiogenesis in a mouse model of oxygen-induced retinopathy

Retinal diseases characterized by pathologic retinal angiogenesis are the leading causes of blindness worldwide. Although therapies directed toward vascular endothelial growth factor (VEGF) represent a significant step forward in the treatment of proliferative retinopathies, further improvements are needed. In the last few years, an intense research activity has focused around the use of herbal and traditional natural medicines as an alternative for slowing down the progression of proliferative retinopathies. In the present study, we investigated the antiangiogenic effects of acetyl-11-keto-β-boswellic acid (AKBA), one of the active principles derived from the plant Boswellia serrata, used in Ayurvedic systems of medicine. We studied the antiangiogenic properties of AKBA using the mouse model of oxygen-induced retinopathy (OIR), which mimics the neovascular response seen in human retinopathy of prematurity. We first evaluated the effects of subcutaneously administered AKBA on the expression/activity of proteins which are known to play a role in the OIR model. In the retina, AKBA increased expression and activity of Src homology region 2 domain-containing phosphatase 1 and reduced the phosphorylation of the transcription factor signal transducer and activator of transcription 3 (STAT3) as well as VEGF expression and VEGF receptor (VEGFR)-2 phosphorylation. Likely as a result of these effects, AKBA significantly reduced retinal neovascularization in OIR mice without affecting retinal cell survival and retinal function. Using retinal explants cultured in hypoxia and an activator of STAT3 phosphorylation, we showed that the AKBA-induced inhibition of VEGFR-2 phosphorylation is likely to be mediated by a mechanism depending on an SHP-1/STAT3/VEGF axis. In the OIR model, neovascularization results from the activation of retinal endothelial cells, therefore we evaluated whether AKBA affected the angiogenic response of human retinal microvascular endothelial cells (HRMECs). We observed that AKBA reduced proliferation, migration and tube formation in HRMECs stimulated with exogenous VEGF, while it reduced migration and tube formation in untreated HRMECs. Taken together, our results demonstrate the antiangiogenic effects of AKBA in a model of pathologic neovascularization, providing a rationale for further investigation of AKBA as a promising therapeutic agent to reduce the impact of proliferative retinopathies.

Dietary ω-3 polyunsaturated fatty acids decrease retinal neovascularization by adipose–endoplasmic reticulum stress reduction to increase adiponectin

Retinopathy of prematurity (ROP) is a vision-threatening disease in premature infants. Serum adiponectin (APN) concentrations positively correlate with postnatal growth and gestational age, important risk factors for ROP development. Dietary ω-3 (n-3) long-chain polyunsaturated fatty acids (ω-3 LCPUFAs) suppress ROP and oxygen-induced retinopathy (OIR) in a mouse model of human ROP, but the mechanism is not fully understood. We examined the role of APN in ROP development and whether circulating APN concentrations are increased by dietary ω-3 LCPUFAs to mediate the protective effect in ROP. Serum APN concentrations were correlated with ROP development and serum ω-3 LCPUFA concentrations in preterm infants. Mouse OIR was then used to determine whether ω-3 LCPUFA supplementation increases serum APN concentrations, which then suppress retinopathy. We found that in preterm infants, low serum APN concentrations positively correlate with ROP, and serum APN concentrations positively correlate with serum ω-3 LCPUFA concentrations. In mouse OIR, serum total APN and bioactive high-molecular-weight APN concentrations are increased by ω-3 LCPUFA feed. White adipose tissue, where APN is produced and assembled in the endoplasmic reticulum, is the major source of serum APN. In mouse OIR, adipose endoplasmic reticulum stress is increased, and APN production is suppressed. ω-3 LCPUFA feed in mice increases APN production by reducing adipose endoplasmic reticulum stress markers. Dietary ω-3 LCPUFA suppression of neovascularization is reduced from 70% to 10% with APN deficiency. APN receptors localize in the retina, particularly to pathologic neovessels. Our findings suggest that increasing APN by ω-3 LCPUFA supplementation in total parental nutrition for preterm infants may suppress ROP.

Correspondence of retinal thinning and vasculopathy in mice with oxygen-induced retinopathy

The aberrantly vascularized peripheral retina in retinopathy of prematurity (ROP) may be associated with visual field constriction, retinal dysfunction, and abnormalities in retinal thickness which is commonly assessed by spectral domain optical coherence tomography (SDOCT). However, due to the limitation of SDOCT for peripheral retinal imaging, retinal thickness in avascular peripheral retina in ROP has not been evaluated. Oxygen induced retinopathy (OIR) in mice has features of vasculopathy similar to those in human ROP. These features occur in the posterior retina and thereby are accessible by standard imaging methods. The purpose of the current study was to determine the correspondence between abnormalities in retinal thickness and vasculopathy in neonatal OIR mice by simultaneous SDOCT imaging and fluorescein angiography (FA). Newborn mice (N = 19; C57BL/6J strain) were exposed to 77% oxygen from postnatal day 7 (P7) to P12. Age-matched control mice (N = 12) were raised in room air. FA and SDOCT were performed in mice between P17 and P19 to visualize retinal vasculature and measure retinal thickness, respectively. Retinal thickness measurements in vascular regions of interest (ROIs) of control mice, and in hypovascular and avascular ROIs of OIR mice were compared. In control mice, FA showed uniformly dense retinal capillary networks between major retinal vessels and retinal thickness of vascular ROIs was 260 ± 7 μm (N = 12). In OIR mice, FA displayed hypovascular regions with less dense and fewer capillaries and avascular regions devoid of visible capillaries. Retinal thickness measurements of hypovascular and avascular ROIs were 243 ± 21 μm and 209 ± 11 μm (N = 19), respectively. Retinal thickness in hypovascular and avascular ROIs of OIR mice was significantly lower than in vascular ROIs of control mice (p ≤ 0.01). Likewise, retinal thickness in avascular ROIs was significantly lower than in hypovascular ROIs (p < 0.001). Retinal thinning in hypovascular and avascular regions may be due to arrested retinal development and/or ischemia induced apoptosis.

The Effect of Lutein and Zeaxanthin on Premature Infant Eye Development

Infant eye development is a complex process highly impacted by premature birth. Current prevention and treatment options for retinopathy of prematurity (ROP), one of the significant comorbities of prematurity, are limited and arguably ineffective. The objective of this review was to evaluate the current literature on lutein and zeaxanthin in preterm infants. Secondary to their supportive role in eye development and functionality, it is hypothesized that they are able to modulate the development and progression of ROP. Lutein and zeaxanthin concentrations in human milk are highest during early milk production and significantly differ among populations. The literature reviewed shows an inverse correlation of maternal human milk consumption and ROP incidence. Xanthophyll supplementation studies, although deemed safe, have not shown significant improvements in ROP reduction, although multiple limitations are noted. Currently supplemented infant formulas with lutein and zeaxanthin are effective at decreasing inflammation and potentially provide photoreceptor protection. The current literature available remains inconclusive regarding lutein and zeaxanthin supplementation on decreasing ROP incidence. Further randomized controlled trials that rigorously control for confounding variables are required.

Preliminary study of retinal pathological features in preterm birth pups exposed to an animal model of oxygen-induced retinopathy in mice

The main risk factors of retinopathy of prematurity (ROP) are low gestational age and low birth weight, which are mainly caused by preterm birth. Currently, the animal model of oxygen-induced retinopathy (OIR) in mice is the most widely used model in ROP-associated studies. However, the experimental mice are normal-term pups, and may not mimic the pathogenic status of human ROP patients. In this study, we investigated the retinal pathological features in preterm birth pups exposed to an animal model of oxygen-induced retinopathy in mice. Preterm-birth mice were obtained from pregnant C57BL/6J mice that were induced by an intraperitoneal injection of lipopolysaccharide (LPS). The preterm and control mice were treated with high oxygen (75%) from postnatal day 7 (P7) to P12. The mice were perfused with high-molecular-weight FITC-dextran on P12, P15 and P17, and the retinas were whole-mounted and imaged. Vascular endothelial growth factor (VEGF) mRNA was also detected. Cross-sections of the retina were stained with hematoxylin and eosin (H&E) to identify preretinal neovascular tufts. For general observation, whole retinal images were also obtained using a microscope. Leakage of the retinal blood vessels was aggravated in the preterm mice, particularly on P12 and P15. The non-perfused areas of the retina (pixel value, 183,673 ± 28,148 vs 132,110 ± 23,732, P = 0.009) and the number of preretinal endothelial cell nuclei were smaller (30.17 ± 8.33 vs 22.17 ± 6.74, P < 0.0001) on P17. The VEGF mRNA levels in the retinas were higher on P12 and P15 but lower on P17, compared with the control mice. Retinal hemorrhage was observed in the preterm mouse group (five out of six examined eyes). Preterm-birth mice that were subject to OIR exhibited several pathological features, such as retinal hemorrhage, severe retinal leakage and moderate retinal neovascularization, which were similar to the clinical manifestations in ROP patients.

Urgent need of establishment of new animal models of retinopathy of prematurity

The etiological factors and pathogenesis of retinopathy of prematurity (ROP) are still unclear,which restricted its effective prevention and treatment.The current animal model widely used in ROP investigation is oxygen-induced retinopathy model,which is lack of specificity,and does not mimic the real pathogenesis status of human ROP patients.Thus,we should refresh our concept,seek breakthroughs in multi-disciplines,integrate more risk factors of ROP,utilize the rising technique in transgenic animal,and improve the evaluation system for improving the current models or explore new animal models of ROP.It is important for prevention and treatment of ROP. Key words: Retinopathy of prematurity; Disease Models, animal; Editorial

Long-term effects of retinopathy of prematurity (ROP) on rod and rod-driven function

The purpose of this study was to determine whether recovery of scotopic sensitivity occurs in human ROP, as it does in the rat models of ROP. Following a cross-sectional design, scotopic electroretinographic (ERG) responses to full-field stimuli were recorded from 85 subjects with a history of preterm birth. In 39 of these subjects, dark adapted visual threshold was also measured. Subjects were tested post-term as infants (median age 2.5 months) or at older ages (median age 10.5 years) and stratified by severity of ROP: severe, mild, or none. Rod photoreceptor sensitivity, S (ROD), was derived from the a-wave, and post-receptor sensitivity, log σ, was calculated from the b-wave stimulus-response function. Dark adapted visual threshold was measured using a forced-choice preferential procedure. For S (ROD), the deficit from normal for age varied significantly with ROP severity but not with age group. For log σ, in mild ROP, the deficit was smaller in older subjects than in infants, while in severe ROP, the deficit was quite large in both age groups. In subjects who never had ROP, S (ROD) and log σ in both age groups were similar to those in term born controls. Deficits in dark adapted threshold and log σ were correlated in mild but not in severe ROP. The data are evidence that sensitivity of the post-receptor retina improves in those with a history of mild ROP. We speculate that beneficial reorganization of the post-receptor neural circuitry occurs in mild but not in severe ROP.

367 Genomic profiles of single tumour cells in metastatic breast cancer patients

Retinopathy of prematurity (ROP) is a severe retinal dysfunction in prematurely born babies. The relationship between non-coding RNAs and retinopathy of prematurity (ROP) remain unclear. Microarray analysis of lncRNAs, miRNAs, and mRNAs was conducted in a mouse model of ROP. A competing endogenous RNA (ceRNA) network was constructed. The relationship among MALAT1, miR-124–3p, and Early growth response protein 1 (EGR1) was assessed in hypoxia-induced primary human umbilical vein endothelial cells (HUVECs) and ROP mouse model. In the study, we found 2252 lncRNAs, 1239 mRNAs, and 36 miRNAs were differentially regulated. ceRNA network consisting of 21 lncRNAs, 10 miRNAs, and 19 mRNAs was established. Of the most down-regulated miRNAs, miR-124–3p was selected for additional study. miR-124–3p ceased the migration and proliferation of primary HUVECs in hypoxic conditions, and directly suppressed EGR1. Additionally, MALAT1 directly sponged miR-124–3p. Knockdown of MALAT1 decreased EGR1 expression and inhibited the migration and proliferation of primary HUVECs in hypoxia. Furthermore, these changes were rescued by depletion of miR-124–3p. In vivo, intravitreal injection of miR-124–3p, shMALAT1 decreased EGR1 expression and markedly suppressed retinal neovascularization in OIR models. Intravitreal injection of shMALAT1 and miR-124–3p antagomir at the same time can promote retinal neovascularization, which reversed the suppression of retinal neovascularization functioned by shMALAT1. In conclusion, the expression profiles of lncRNAs and miRNAs and the ceRNA network in a mouse model of ROP may be indicative of the underlying mechanisms of retinal angiogenesis and neural activity. The MALAT1/miR-124–3p/EGR1 regulatory axis is partly responsible for retinal neovascularization, which may provide a novel theoretical basis for the pathogenesis of ROP.

823 Pathway signatures in breast cancer progression − a genome-scale study based on integration of biology networks, DNA copy number, gene expression and mutations

Retinopathy of prematurity (ROP) is a severe retinal dysfunction in prematurely born babies. The relationship between non-coding RNAs and retinopathy of prematurity (ROP) remain unclear. Microarray analysis of lncRNAs, miRNAs, and mRNAs was conducted in a mouse model of ROP. A competing endogenous RNA (ceRNA) network was constructed. The relationship among MALAT1, miR-124–3p, and Early growth response protein 1 (EGR1) was assessed in hypoxia-induced primary human umbilical vein endothelial cells (HUVECs) and ROP mouse model. In the study, we found 2252 lncRNAs, 1239 mRNAs, and 36 miRNAs were differentially regulated. ceRNA network consisting of 21 lncRNAs, 10 miRNAs, and 19 mRNAs was established. Of the most down-regulated miRNAs, miR-124–3p was selected for additional study. miR-124–3p ceased the migration and proliferation of primary HUVECs in hypoxic conditions, and directly suppressed EGR1. Additionally, MALAT1 directly sponged miR-124–3p. Knockdown of MALAT1 decreased EGR1 expression and inhibited the migration and proliferation of primary HUVECs in hypoxia. Furthermore, these changes were rescued by depletion of miR-124–3p. In vivo, intravitreal injection of miR-124–3p, shMALAT1 decreased EGR1 expression and markedly suppressed retinal neovascularization in OIR models. Intravitreal injection of shMALAT1 and miR-124–3p antagomir at the same time can promote retinal neovascularization, which reversed the suppression of retinal neovascularization functioned by shMALAT1. In conclusion, the expression profiles of lncRNAs and miRNAs and the ceRNA network in a mouse model of ROP may be indicative of the underlying mechanisms of retinal angiogenesis and neural activity. The MALAT1/miR-124–3p/EGR1 regulatory axis is partly responsible for retinal neovascularization, which may provide a novel theoretical basis for the pathogenesis of ROP.

47 Molecular signatures of long non-coding RNAs in breast cancer patients

Retinopathy of prematurity (ROP) is a severe retinal dysfunction in prematurely born babies. The relationship between non-coding RNAs and retinopathy of prematurity (ROP) remain unclear. Microarray analysis of lncRNAs, miRNAs, and mRNAs was conducted in a mouse model of ROP. A competing endogenous RNA (ceRNA) network was constructed. The relationship among MALAT1, miR-124–3p, and Early growth response protein 1 (EGR1) was assessed in hypoxia-induced primary human umbilical vein endothelial cells (HUVECs) and ROP mouse model. In the study, we found 2252 lncRNAs, 1239 mRNAs, and 36 miRNAs were differentially regulated. ceRNA network consisting of 21 lncRNAs, 10 miRNAs, and 19 mRNAs was established. Of the most down-regulated miRNAs, miR-124–3p was selected for additional study. miR-124–3p ceased the migration and proliferation of primary HUVECs in hypoxic conditions, and directly suppressed EGR1. Additionally, MALAT1 directly sponged miR-124–3p. Knockdown of MALAT1 decreased EGR1 expression and inhibited the migration and proliferation of primary HUVECs in hypoxia. Furthermore, these changes were rescued by depletion of miR-124–3p. In vivo, intravitreal injection of miR-124–3p, shMALAT1 decreased EGR1 expression and markedly suppressed retinal neovascularization in OIR models. Intravitreal injection of shMALAT1 and miR-124–3p antagomir at the same time can promote retinal neovascularization, which reversed the suppression of retinal neovascularization functioned by shMALAT1. In conclusion, the expression profiles of lncRNAs and miRNAs and the ceRNA network in a mouse model of ROP may be indicative of the underlying mechanisms of retinal angiogenesis and neural activity. The MALAT1/miR-124–3p/EGR1 regulatory axis is partly responsible for retinal neovascularization, which may provide a novel theoretical basis for the pathogenesis of ROP.

Hereditary influences in oxygen-induced retinopathy in the rat

Rodent models of oxygen-induced retinopathy (OIR) provide important insights into the pathogenesis of human retinopathy of prematurity. Herein, we present an overview of our work with rat OIR to date. We have identified marked and consistent variations in susceptibility to OIR amongst different inbred rat strains and provide strong evidence for a genetic determinant of susceptibility to OIR. Furthermore, we have characterised differences in retinal angiogenic factor gene expression amongst different inbred rat strains exposed to cyclic hyperoxia. A key determinant of susceptibility to OIR appears to be the extent to which pro-angiogenic factor genes, such as vascular endothelial growth factor and erythropoietin, are expressed during the period of hyperoxic exposure. Those strains in which expression is relatively well maintained are less susceptible to retinopathy than are those in which expression is reduced. In addition, we identify an association between ocular pigmentation and OIR susceptibility.

The neurovascular retina in retinopathy of prematurity.

The continuing worldwide epidemic of retinopathy of prematurity (ROP), a leading cause of childhood visual impairment, strongly motivates further research into mechanisms of the disease. Although the hallmark of ROP is abnormal retinal vasculature, a growing body of evidence supports a critical role for the neural retina in the ROP disease process. The age of onset of ROP coincides with the rapid developmental increase in rod photoreceptor outer segment length and rhodopsin content of the retina with escalation of energy demands. Using a combination of non-invasive electroretinographic (ERG), psychophysical, and image analysis procedures, the neural retina and its vasculature have been studied in prematurely born human subjects, both with and without ROP, and in rats that model the key vascular and neural parameters found in human ROP subjects. These data are compared to comprehensive numeric summaries of the neural and vascular features in normally developing human and rat retina. In rats, biochemical, anatomical, and molecular biological investigations are paired with the non-invasive assessments. ROP, even if mild, primarily and persistently alters the structure and function of photoreceptors. Post-receptor neurons and retinal vasculature, which are intimately related, are also affected by ROP; conspicuous neurovascular abnormalities disappear, but subtle structural anomalies and functional deficits may persist years after clinical ROP resolves. The data from human subjects and rat models identify photoreceptor and post-receptor targets for interventions that promise improved outcomes for children at risk for ROP.

The effect of oxygen and light on the structure and function of the neonatal rat retina

The neonatal rat is born with its eyes closed and an immature visual system, that some say is equivalent to that of a human fetus at 26 weeks of gestation. From birth, the visual system of the newborn rat will gradually mature, the first manifestation of that being the opening of the eye which usually take place at postnatal day 14. Complete maturation of the retina and visual pathways is normally reached at the end of the first month of life. The neonatal rat model thus represents a unique paradigm to study the normal and abnormal maturation of the primary visual pathways that normally occurs in utero in human subjects. Our laboratory has, over the past decade, developed two animal models of postnatally induced retinopathy, namely the Oxygen-Induced Retinopathy (OIR) that share several common features with the human Retinopathy of Prematurity (ROP) and the Light-Induced Retinopathy that is viewed by some as a valid model of some forms of Retinitis Pigmentosa (RP). The following pages review what is known of the pathophysiological processes taking place and suggest possible therapeutic avenues that could be explored in order to halt the degenerative process.

Retinal degenerative and hypoxic ischemic disease

A broad spectrum of retinal diseases affects both the retinal vasculature and the neural retina, including photoreceptor and postreceptor layers. The accepted clinical hallmarks of acute retinopathy of prematurity (ROP) are dilation and tortuosity of the retinal vasculature. Additionally, significant early and persistent effects on photoreceptor and postreceptor neural structures and function are demonstrated in ROP. In this paper, we focus on the results of longitudinal studies of electroretinographic (ERG) and vascular features in rats with induced retinopathies that model the gamut of human ROP, mild to severe. Two potential targets for pharmaceutical interventions emerge from the observations. The first target is immature photoreceptors because the status of the photoreceptors at an early age predicts later vascular outcome; this approach is appealing as it holds promise to prevent ROP. The second target is the interplay of the neural and vascular retinal networks, which develop cooperatively. Beneficial pharmaceutical interventions may be measured in improved visual outcome as well as lessening of the vascular abnormalities.