Dataset Information

Inhibiting microRNA-144 potentiates Nrf2-dependent antioxidant signaling in RPE and protects against oxidative stress-induced outer retinal degeneration.

ABSTRACT: The retinal pigment epithelium (RPE) is consistently exposed to high levels of pro-oxidant and inflammatory stimuli. As such, under normal conditions the antioxidant machinery in the RPE cell is one of the most efficient in the entire body. However, antioxidant defense mechanisms are often impacted negatively by the process of aging and/or degenerative disease leaving RPE susceptible to damage which contributes to retinal dysfunction. Thus, understanding better the mechanisms governing antioxidant responses in RPE is critically important. Here, we evaluated the role of the redox sensitive microRNA miR-144 in regulation of antioxidant signaling in human and mouse RPE. In cultured human RPE, miR-144-3p and miR-144-5p expression was upregulated in response to pro-oxidant stimuli. Likewise, overexpression of miR-144-3p and -5p using targeted miR mimics was associated with reduced expression of Nrf2 and downstream antioxidant target genes (NQO1 and GCLC), reduced levels of glutathione and increased RPE cell death. Alternately, some protection was conferred against the above when miR-144-3p and miR-144-5p expression was suppressed using antagomirs. Expression analyses revealed a higher conservation of miR-144-3p expression across species and additionally, the presence of two potential Nrf2 binding sites in the 3p sequence compared to only one in the 5p sequence. Thus, we evaluated the impact of miR-144-3p expression in the retinas of mice in which a robust pro-oxidant environment was generated using sodium iodate (SI). Subretinal injection of miR-144-3p antagomir in SI mice preserved retinal integrity and function, decreased oxidative stress, limited apoptosis and enhanced antioxidant gene expression. Collectively, the present work establishes miR-144 as a potential target for preventing and treating degenerative retinal diseases in which oxidative stress is paramount and RPE is prominently affected (e.g., age-related macular degeneration and diabetic retinopathy).

SUBMITTER: Jadeja RN

PROVIDER: S-EPMC6812120 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature

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Inhibiting microRNA-144 potentiates Nrf2-dependent antioxidant signaling in RPE and protects against oxidative stress-induced outer retinal degeneration.

Jadeja Ravirajsinh N RN Jones Malita A MA Abdelrahman Ammar A AA Powell Folami L FL Thounaojam Menaka C MC Gutsaeva Diana D Bartoli Manuela M Martin Pamela M PM

Redox biology 20190929

The retinal pigment epithelium (RPE) is consistently exposed to high levels of pro-oxidant and inflammatory stimuli. As such, under normal conditions the antioxidant machinery in the RPE cell is one of the most efficient in the entire body. However, antioxidant defense mechanisms are often impacted negatively by the process of aging and/or degenerative disease leaving RPE susceptible to damage which contributes to retinal dysfunction. Thus, understanding better the mechanisms governing antioxida ...[more]

PMID: 31590045

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Project description:BackgroundAge-related macular degeneration (AMD), characterized by the degeneration of retinal pigment epithelium (RPE) and photoreceptors, is the leading cause of irreversible vision impairment among the elderly. RPE senescence is an important contributor to AMD and has become a potential target for AMD therapy. HTRA1 is one of the most significant susceptibility genes in AMD, however, the correlation between HTRA1 and RPE senescence hasn't been investigated in the pathogenesis of AMD.MethodsWestern blotting and immunohistochemistry were used to detect HTRA1 expression in WT and transgenic mice overexpressing human HTRA1 (hHTRA1-Tg mice). RT-qPCR was used to detect the SASP in hHTRA1-Tg mice and ARPE-19 cells infected with HTRA1. TEM, SA-β-gal was used to detect the mitochondria and senescence in RPE. Retinal degeneration of mice was investigated by fundus photography, FFA, SD-OCT and ERG. The RNA-Seq dataset of ARPE-19 cells treated with adv-HTRA1 versus adv-NC were analyzed. Mitochondrial respiration and glycolytic capacity in ARPE-19 cells were measured using OCR and ECAR. Hypoxia of ARPE-19 cells was detected using EF5 Hypoxia Detection Kit. KC7F2 was used to reduce the HIF1α expression both in vitro and in vivo.ResultsIn our study, we found that RPE senescence was facilitated in hHTRA1-Tg mice. And hHTRA1-Tg mice became more susceptible to NaIO3 in the development of oxidative stress-induced retinal degeneration. Similarly, overexpression of HTRA1 in ARPE-19 cells accelerated cellular senescence. Our RNA-seq revealed an overlap between HTRA1-induced differentially expressed genes associated with aging and those involved in mitochondrial function and hypoxia response in ARPE-19 cells. HTRA1 overexpression in ARPE-19 cells impaired mitochondrial function and augmented glycolytic capacity. Importantly, upregulation of HTRA1 remarkably activated HIF-1 signaling, shown as promoting HIF1α expression which mainly located in the nucleus. HIF1α translation inhibitor KC7F2 significantly prevented HTRA1-induced cellular senescence in ARPE-19 cells, as well as improved the visual function in hHTRA1-Tg mice treated with NaIO3.ConclusionsOur study showed elevated HTRA1 contributes to the pathogenesis of AMD by promoting cellular senescence in RPE through damaging mitochondrial function and activating HIF-1 signaling. It also pointed out that inhibition of HIF-1 signaling might serve as a potential therapeutic strategy for AMD. Video Abstract.

Dataset Information

Inhibiting microRNA-144 potentiates Nrf2-dependent antioxidant signaling in RPE and protects against oxidative stress-induced outer retinal degeneration.

Publications

Inhibiting microRNA-144 potentiates Nrf2-dependent antioxidant signaling in RPE and protects against oxidative stress-induced outer retinal degeneration.

Similar Datasets

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