Inhibiting HIF-1 signaling alleviates HTRA1-induced RPE senescence in retinal degeneration

Abstract

Background Age-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. Methods Western 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. Results In 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. Conclusions Our 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.

Fructose vs. Glucose: Modulating Stem Cell Growth and Function Through Sugar Supplementation

“…Conversely, we found that Igfbp3 expression decreased when Hif1a was knocked down, regardless of the sugar type used. The induction of Hif1a influence the production of cytokines associated with the senescence-related phenotype 33,56 , aligning with our findings that demonstrate an increase in P16 and P21 immunosignals. Interestingly, we showed that IL4, IL8, and IL10 were increased in the fructose containing medium along with the reduction in GDF15, a growth factor that supports proliferation 26 .…”

Progress in the Study of the Role and Mechanism of HTRA1 in Diseases Related to Vascular Abnormalities

“…HTRA1 plays an important role in vascular homeostasis by regulating signaling pathways or refolding, translocation, and degradation of extracellular matrix proteins, thereby directly or indirectly regulating angiogenesis and vascular remodeling, and vascular and related structural dysfunction caused by abnormal function of the HTRA1 gene is an important initiator and high risk factor. This article suggests that more research on vascular diseases involving cardiovascular, 120 renal, 121 and hepatic diseases 122 should include HTRA1 as an important research target, and even in the process of tissue repair and regeneration, 123 scarring, 124 senescence, 125 , 126 and pregnancy complications 87 should include HTRA1 as an indispensable research component.…”

Age-Related Macular Degeneration: A Disease of Cellular Senescence and Dysregulated Immune Homeostasis

“… 19 The role of HTRA1 in AMD cellular senescence is multifaceted, involving oxidative stress response, mitochondrial function, and regulation of hypoxia-inducible factor-1 and p38 mitogen-activated protein kinase signaling pathways, inducing RPE senescence, extracellular matrix deposition, and AMD-related choroidal vasculopathy. 20 , 21 The differential expression of bone morphogenetic protein 4 (BMP4) across AMD subtypes is intimately linked to cellular senescence. In dry AMD patients, high BMP4 expression activates p53 via the Smad and p38 signaling pathways, increases p21 WAF1/CIP1 expression, and decreases pRb levels, thereby mediating RPE senescence.…”