bims-mideyd Biomed News
on Mitochondrial dysfunction in eye diseases
Issue of 2025–03–23
six papers selected by
Rajalekshmy “Raji” Shyam, Indiana University Bloomington
  1. Lycium barbarum polysaccharide alleviates H2O2-induced premature senescence by downregulating miRNA-34a-5p in ARPE-19 cells.
  2. Retinal Pigment Epithelium and Monocytes' Mitochondrial Control of Ferroptosis and its Relevance to Age-Related Macular Degeneration.
  3. The role of retinal pigment epithelial senescence and the potential of senotherapeutics in age-related macular degeneration.
  4. LEF1 influences diabetic retinopathy and retinal pigment epithelial cell ferroptosis via the miR-495-3p/GRP78 axis through lnc-MGC.
  5. CRISPR targeting of SNPs associated with age-related macular degeneration in ARPE-19 cells: a potential model for manipulating the complement system.
  6. Therapeutic potential of AAV2-shmTOR gene therapy in reducing retinal inflammation and preserving endothelial Integrity in age-related macular degeneration.
  1. Cell Stress Chaperones. 2025 Mar 18. pii: S1355-8145(25)00017-3. [Epub ahead of print]
    Lycium barbarum polysaccharide alleviates H2O2-induced premature senescence by downregulating miRNA-34a-5p in ARPE-19 cells.
    Meng Kong, Jingwen Li, Rong Jin, Yi Zhang, Jia You, Nan Wang, Nianting Tong.
       BACKGROUNDS: The premature senescence of retinal pigment epithelium (RPE) plays a significant role in the development of age-related macular degeneration. This study aimed to investigate the protective effect of Lycium barbarum polysaccharide (LBP) against H2O2-induced premature senescence and to elucidate the underlying mechanisms.
    METHODS: The ARPE-19 cell line was subjected to H2O2 exposure to create a model of premature senescence. Following the establishment of the model, cells were maintained in the presence or absence of LBP. The modulation of microRNA (miRNA)-34a-5p expression was accomplished using antagomir and agomir, as assessed by quantitative real-time polymerase chain reaction.
    RESULTS: The senescence model was successfully established by treating cells with 200μM H2O2 for 2hours daily over a span of three consecutive days. This oxidative stress resulted in a notable increase in the proportion of senescence-associated beta-galactosidase-positive cells, reaching 33.5%, without significant alterations in cell viability or apoptosis. In the ARPE-19 cells undergoing premature senescence, there was a marked increase in reactive oxygen species (ROS) production and malondialdehyde (MDA) levels, coupled with a significant decrease in the activity of total superoxide dismutase (SOD), glutathione peroxidase (GSH px), and catalase (CAT). Additionally, miRNA-34a-5p was found to be overexpressed in these cells. Treatment with LBP alleviated H2O2-induced premature senescence, diminished the overexpression of miRNA-34a-5p, and suppressed ROS production. Moreover, the incubation with ago-34a reversed the protective effect of LBP in ARPE-19 cells.
    CONCLUSION: The overexpression of miRNA-34a-5p contributes to the H2O2-induced premature senescence of ARPE-19 cells. LBP appears to mitigate this premature senescence, at least in part, by downregulating miRNA-34a-5p expression and reducing oxidative stress.
    Keywords:  Lycium barbarum polysaccharide; microRNA-34a-5p; oxidative stress; premature senescence; retinal pigment epithelium
    DOI:  https://doi.org/10.1016/j.cstres.2025.03.002
  2. Mol Neurobiol. 2025 Mar 18.
    Retinal Pigment Epithelium and Monocytes' Mitochondrial Control of Ferroptosis and its Relevance to Age-Related Macular Degeneration.
    Mithalesh Kumar Singh, Lata Singh, Shari Atilano, Marilyn Chwa, Nasim Salimiaghdam, M Cristina Kenney.
      Age-related macular degeneration (AMD) is the leading cause of vision impairment among older aged people. Recent studies have indicated that focusing on the underlying mechanism of ferroptosis (a form of iron-dependent cell death) could be crucial in understanding the progression of AMD, as it is strongly linked with inflammation. However, the specific dependence of ferroptosis on the mitochondria in the retinal pigment epithelium (RPE) and its surrounding immune cells remains unclear. In this study, we showed that mitochondria were required for the proliferation and maintenance of the RPE by regulating the expression of genes implicated in both pro- and antiferroptosis activities. Under chemically induced hypoxic conditions, Wt-ARPE-19 cells (basal mitochondrial level) increased the expression of genes linked with antiferroptotic activity. In contrast, rho0-ARPE-19 cells (mitochondria depleted) did not stimulate either pro- or antiferroptosis gene expression. However, diff-ARPE-19 cells (abundant in mitochondria) presented an improved proferroptotic activity. Furthermore, we demonstrated that mitochondria regulated monocyte differentiation into macrophages, resulting in differential expression of pro- and antiferroptotic factors. Through a direct coculture approach, the absence of mitochondria in ARPE-19 cells was shown to influences monocyte differentiation toward an inflammatory phenotype. This differentiation might increase ferroptosis activity. Transmitochondrial cybrids derived from patients with dry AMD and age-matched controls without dry AMD presented elevated mtDNA copy numbers, leading to increased ferritinophagy and increased levels of polyunsaturated fatty acids. These data highlighted that ferroptosis was partly regulated by mitochondria and that understanding the mechanisms governing the relationship between mitochondria and ferroptosis may open new potential avenues for managing dry AMD.
    Keywords:   rho0 ; Cybrids; Differentiated ARPE-19; Dry-age macular degeneration; Ferroptosis; Mitochondria; Monocytes
    DOI:  https://doi.org/10.1007/s12035-025-04832-6
  3. Surv Ophthalmol. 2025 Mar 13. pii: S0039-6257(25)00053-0. [Epub ahead of print]
    The role of retinal pigment epithelial senescence and the potential of senotherapeutics in age-related macular degeneration.
    Yingying Chen, Feipeng Jiang, Yue Zeng, Meixia Zhang.
      Age-related macular degeneration (AMD) is a leading cause of visual impairment in the aging population. Evidence showing the presence of cellular senescence in retinal pigment epithelium (RPE) of patients with AMD is growing. Senescent RPE play a pivotal role in its pathogenesis. The senescent RPE suffers from structural and functional alterations and disruption of the surrounding microenvironment due to the development of the senescence-associated secretory phenotype, which contributes to metabolic dysfunctions and inflammatory responses in the retina. Senotherapeutics, including senolytics, senomorphics and others, are novel treatments targeting senescent cells and are promising treatments for AMD. As senotherapeutic targets are being developed, it is promising that the burden of AMD could be decreased.
    Keywords:  Age-related macular degeneration; Retinal pigment epithelium; Senescence; Senolytics; Senotherapeutics
    DOI:  https://doi.org/10.1016/j.survophthal.2025.03.004
  4. World J Diabetes. 2025 Mar 15. 16(3): 92003
    LEF1 influences diabetic retinopathy and retinal pigment epithelial cell ferroptosis via the miR-495-3p/GRP78 axis through lnc-MGC.
    Yi-Yi Luo, Xue-Ying Ba, Ling Wang, Ye-Pin Zhang, Hong Xu, Pei-Qi Chen, Li-Bo Zhang, Jian Han, Heng Luo.
       BACKGROUND: Diabetic retinopathy (DR) is one of the major eye diseases contributing to blindness worldwide. Endoplasmic reticulum (ER) stress in retinal cells is a key factor leading to retinal inflammation and vascular leakage in DR, but its mechanism is still unclear.
    AIM: To investigate the potential mechanism of LEF1 and related RNAs in DR.
    METHODS: ARPE-19 cells were exposed to high levels of glucose for 24 hours to simulate a diabetic environment. Intraperitoneally injected streptozotocin was used to induce the rat model of DR. The expression levels of genes and related proteins were measured by RT-qPCR and Western blotting; lnc-MGC and miR-495-3p were detected by fluorescent in situ hybridization; CCK-8 and TUNEL assays were used to detect cell viability and apoptosis; enzyme-linked immunosorbent assay was used to detect inflammatory factors; dual-luciferase gene assays were used to verify the targeting relationship; and the retina was observed by HE staining.
    RESULTS: LEF1 and lnc-MGC have binding sites, and lnc-MGC can regulate the miR-495-3p/GRP78 molecular axis. In high glucose-treated cells, inflammation was aggravated, the intracellular reactive oxygen species concentration was increased, cell viability was reduced, apoptosis was increased, the ER response was intensified, and ferroptosis was increased. As an ER molecular chaperone, GRP78 regulates the ER and ferroptosis under the targeting of miR-495-3p, whereas inhibiting LEF1 can further downregulate the expression of lnc-MGC, increase the level of miR-495-3p, and sequentially regulate the level of GRP78 to alleviate the occurrence and development of DR. Animal experiments indicated that the knockdown of LEF1 can affect the lnc-MGC/miR-495-3p/GRP78 signaling axis to restrain the progression of DR.
    CONCLUSION: LEF1 knockdown can regulate the miR-495-3p/GRP78 molecular axis through lnc-MGC, which affects ER stress and restrains the progression of DR and ferroptosis in retinal pigment epithelial cells.
    Keywords:  Diabetic retinopathy; Endoplasmic reticulum stress; Ferroptosis; Lnc-MGC; Retinal pigment epithelium cells; miR-495-3p/GRP78
    DOI:  https://doi.org/10.4239/wjd.v16.i3.92003
  5. Gene Ther. 2025 Mar 18.
    CRISPR targeting of SNPs associated with age-related macular degeneration in ARPE-19 cells: a potential model for manipulating the complement system.
    Ahmed Salman, Won Kyung Song, Tina Storm, Michelle E McClements, Robert E MacLaren.
      Age-related Macular degeneration (AMD) is a major cause of vision loss and is linked to several predisposing single nucleotide polymorphisms (SNPs). CRISPR-mediated genome editing offers the potential to target negatively associated SNPs in an allele-specific manner, necessitating the need for a relevant cell model. The ARPE-19 cell line, with its stable monolayer growth and retinal pigment epithelium (RPE) characteristics, serves as an ideal model for AMD studies. Chronic inflammation and complement system dysregulation are implicated in AMD pathogenesis. Most genetic variations associated with AMD are in complement genes, suggesting their regulatory role. In this study, we conducted targeted PCRs to identify AMD-related SNPs in ARPE-19 cells and used CRISPR constructs to assess allele-specific activity. Guide RNA sequences were cloned into an EF-1-driven SpCas9 vector and packaged into lentivirus. Targeting efficiencies were evaluated with TIDE analysis, and allele-specificity was measured with NGS analysis 30 days post-transduction. Our results showed varying targeting efficiencies depending on guide RNA efficacy. For example, TIDE analysis of CFH SNPs rs1061170 and rs1410996 revealed efficiencies of 35.5% and 33.8%, respectively. CFB SNP rs4541862 showed efficiencies from 3% to 36.7%, and rs641153 ranged from 3.4% to 23.8%. Additionally, allele-specific targeting of AMD-related SNPs rs1061170, rs1410996, rs4541862, and rs641153 ranged from 48% to 52% in heterozygous differentiated ARPE-19 cells. These findings demonstrate the potential to manipulate the complement system in an AMD model by targeting disease-associated SNPs in an allele-specific manner, offering a promising therapeutic approach.
    DOI:  https://doi.org/10.1038/s41434-025-00522-z
  6. Sci Rep. 2025 Mar 19. 15(1): 9517
    Therapeutic potential of AAV2-shmTOR gene therapy in reducing retinal inflammation and preserving endothelial Integrity in age-related macular degeneration.
    Jin Kim, Seo Yun Moon, Ho Geun Kang, Hee Jong Kim, Jun Sub Choi, Steven Hyun Seung Lee, Keerang Park, So-Yoon Won.
      Age-related macular degeneration (AMD) is a prevalent retinal disorder that leads to central vision loss, mainly due to chronic inflammation. Tumor necrosis factor-alpha (TNF-α) is a critical mediator of inflammatory responses within the retinal environment. This study has investigated TNF-α's influence on inflammatory cytokine production and endothelial barrier integrity in human microglial (HMC3) and endothelial (HUVEC) cells. We found that TNF-α significantly elevated the expression and secretion of interleukin-6 (IL-6) and interleukin-1β (IL-1β) in HMC3 cells and disrupted endothelial tight junctions in HUVECs, as evidenced by weakened ZO-1 staining and compromised barrier function. To mitigate these effects and further investigate the in vitro mechanism of actions in CRG-01's in vivo therapeutic efficacy of anti-inflammation, we employed AAV2-shmTOR, CRG-01, as the candidate for therapeutic vector targeting the mammalian target of the rapamycin (mTOR) pathway. TNF-α-induced IL-6, IL-1β, and NF-κB signaling in HMC3 cells were significantly reduced by AAV2-shmTOR treatment, which may present a promising avenue for the fight against AMD. It also effectively preserved endothelial tight junction integrity in TNF-α-treated HUVECs, providing reassurance about its effectiveness. Furthermore, the supernatant medium collected from AAV2-shmTOR-treated HMC3 cells decreased oxidative stress, protein oxidation, and cytotoxicity in ARPE retinal pigment epithelial cells. These results strongly suggested that CRG-01, the candidate therapeutic vector of AAV2-shmTOR, may have a therapeutic potential to treat AMD-related retinal inflammation.
    Keywords:  (Vascular endothelial growth factor (VEGF); Adeno-associated virus (AAV); Age-related macular degeneration (AMD); Gene therapy; Retinal inflammation; ShmTOR
    DOI:  https://doi.org/10.1038/s41598-025-93993-4
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