bims-mideyd 2023-04-02 papers

bims-mideyd

Biomed News

on Mitochondrial dysfunction in eye diseases

Issue of 2023‒04‒02
nine papers selected by
Rajalekshmy “Raji” Shyam, Indiana University Bloomington

Chitooligosaccharides Derivatives Protect ARPE-19 Cells against Acrolein-Induced Oxidative Injury.
Isolation and Identification of Dihydrophenanthrene Derivatives from Dendrobium virgineum with Protective Effects against Hydrogen-Peroxide-Induced Oxidative Stress of Human Retinal Pigment Epithelium ARPE-19 Cells.
Pathologically high intraocular pressure induces mitochondrial dysfunction through Drp1 and leads to retinal ganglion cell PANoptosis in glaucoma.
The Role of Oxidative Stress in the Aging Eye.
Transcriptomic changes predict metabolic alterations in LC3 associated phagocytosis in aged mice.
A Protocol to Evaluate and Quantify Retinal Pigmented Epithelium Pathologies in Mouse Models of Age-Related Macular Degeneration.
Mitochondrial Oxidative Stress and Mitophagy Activation Contribute to TNF-Dependent Impairment of Myogenesis.
Mitochondrial GRIM-19 loss in parietal cells promotes spasmolytic polypeptide-expressing metaplasia through NLR family pyrin domain-containing 3 (NLRP3)-mediated IL-33 activation via a reactive oxygen species (ROS) -NRF2- Heme oxygenase-1(HO-1)-NF-кB axis.
Reduced OPA1, Mitochondrial Fragmentation and Increased Susceptibility to Apoptosis in Granular Corneal Dystrophy Type 2 Corneal Fibroblasts.

Mar Drugs. 2023 Feb 22. pii: 137. [Epub ahead of print]21(3):

Chitooligosaccharides Derivatives Protect ARPE-19 Cells against Acrolein-Induced Oxidative Injury.

Cheng Yang, Rongrong Yang, Ming Gu, Jiejie Hao, Shixin Wang, Chunxia Li.

  Age-related macular degeneration (AMD) is the leading cause of vision loss among the elderly. The progression of AMD is closely related to oxidative stress in the retinal pigment epithelium (RPE). Here, a series of chitosan oligosaccharides (COSs) and N-acetylated derivatives (NACOSs) were prepared, and their protective effects on an acrolein-induced oxidative stress model of ARPE-19 were explored using the MTT assay. The results showed that COSs and NACOs alleviated APRE-19 cell damage induced by acrolein in a concentration-dependent manner. Among these, chitopentaose (COS-5) and its N-acetylated derivative (N-5) showed the best protective activity. Pretreatment with COS-5 or N-5 could reduce intracellular and mitochondrial reactive oxygen species (ROS) production induced by acrolein, increase mitochondrial membrane potential, GSH level, and the enzymatic activity of SOD and GSH-Px. Further study indicated that N-5 increased the level of nuclear Nrf2 and the expression of downstream antioxidant enzymes. This study revealed that COSs and NACOSs reduced the degeneration and apoptosis of retinal pigment epithelial cells by enhancing antioxidant capacity, suggesting that they have the potential to be developed into novel protective agents for AMD treatment and prevention.

Keywords:  ARPE-19; N-acetylated chitosan oligosaccharide; Nrf2; chitosan oligosaccharide; oxidative stress

DOI:  https://doi.org/10.3390/md21030137
Antioxidants (Basel). 2023 Mar 02. pii: 624. [Epub ahead of print]12(3):

Isolation and Identification of Dihydrophenanthrene Derivatives from Dendrobium virgineum with Protective Effects against Hydrogen-Peroxide-Induced Oxidative Stress of Human Retinal Pigment Epithelium ARPE-19 Cells.

Pongsawat Panuthai, Rianthong Phumsuay, Chawanphat Muangnoi, Porames Maitreesophone, Virunh Kongkatitham, Wanwimon Mekboonsonglarp, Pornchai Rojsitthisak, Kittisak Likhitwitayawuid, Boonchoo Sritularak.

  Oxidative stress is a significant factor in the development of age-related macular degeneration (AMD), which results from cell damage, dysfunction, and death in the retinal pigmented epithelium (RPE). The use of natural compounds with antioxidant properties to protect RPE cells from oxidative stress has been explored in Dendrobium, a genus of orchid plants belonging to the family Orchidaceae. Two new compounds and seven known compounds from the MeOH extract of the whole plant of Dendrobium virgineum were successfully isolated and structurally characterized. Out of all the compounds isolated, 2-methoxy-9,10-dihydrophenanthrene-4,5-diol (3) showed the highest protective effect against hydrogen peroxide (H2O2)-induced oxidative stress in human retinal pigment epithelial (ARPE-19) cells. Therefore, it was selected to evaluate its protective effect and mechanism on oxidative-stress-induced ARPE-19 cells. Cells were pre-treated with compound 3 at 25, 50, and 100 µg/mL for 24 h and then induced with 400 µM H2O2 for 1 h. The results demonstrated that compound 3 significantly (p < 0.05) increased cell viability by 10-35%, decreased ROS production by 10-30%, and reduced phosphorylation of p38, ERK1/2, and SAPK/JNK by 20-70% in a dose-dependent manner without toxicity. Furthermore, compound 3 significantly (p < 0.05) modulated the expression of apoptosis pathway proteins (cytochrome c, Bax and Bcl-2) by 20-80%, and enhanced SOD, CAT, and GPX activities, and GSH levels in a dose-dependent manner. These results suggest that compound 3 protects ARPE-19 cells against oxidative stress through MAPKs and apoptosis pathways, including the antioxidant system. Thus, compound 3 could be considered as an antioxidant agent for preventing AMD development by protecting RPE cells from oxidative stress and maintaining the retina. These findings open up new possibilities for the use of natural compounds in the treatment of AMD and other oxidative-stress-related conditions.

Keywords:  Dendrobium virgineum; Orchidaceae; dihydrophenanthrene; oxidative stress; retinal pigment epithelium

DOI:  https://doi.org/10.3390/antiox12030624
Redox Biol. 2023 Mar 21. pii: S2213-2317(23)00088-5. [Epub ahead of print]62 102687

Pathologically high intraocular pressure induces mitochondrial dysfunction through Drp1 and leads to retinal ganglion cell PANoptosis in glaucoma.

Zhou Zeng, Mengling You, Cong Fan, Rong Rong, Haibo Li, Xiaobo Xia.

  Glaucoma is a common neurodegenerative disease characterized by progressive retinal ganglion cell (RGC) loss and visual field defects. Pathologically high intraocular pressure (ph-IOP) is an important risk factor for glaucoma, and it triggers molecularly distinct cascades that control RGC death and axonal degeneration. Dynamin-related protein 1 (Drp1)-mediated abnormalities in mitochondrial dynamics are involved in glaucoma pathogenesis; however, little is known about the precise pathways that regulate RGC injury and death. Here, we aimed to investigate the role of the ERK1/2-Drp1-reactive oxygen species (ROS) axis in RGC death and the relationship between Drp1-mediated mitochondrial dynamics and PANoptosis in ph-IOP injury. Our results suggest that inhibiting the ERK1/2-Drp1-ROS pathway is a potential therapeutic strategy for treating ph-IOP-induced injuries. Furthermore, inhibiting Drp1 can regulate RGC PANoptosis by modulating caspase3-dependent, nucleotide-binding oligomerization domain-like receptor-containing pyrin domain 3(NLRP3)-dependent, and receptor-interacting protein (RIP)-dependent pathways in the ph-IOP model. Overall, our findings provide new insights into possible protective interventions that could regulate mitochondrial dynamics to improve RGC survival.

Keywords:  Dynamin-related protein 1; Glaucoma; Mitochondrial dynamics; PANoptosis; Retinal ganglion cell

DOI:  https://doi.org/10.1016/j.redox.2023.102687
Life (Basel). 2023 Mar 20. pii: 837. [Epub ahead of print]13(3):

The Role of Oxidative Stress in the Aging Eye.

Deniz Goodman, Steven Ness.

  Given the expanding elderly population in the United States and the world, it is important to understand the processes underlying both natural and pathological age-related changes in the eye. Both the anterior and posterior segment of the eye undergo changes in biological, chemical, and physical properties driven by oxidative stress. With advancing age, changes in the anterior segment include dermatochalasis, blepharoptosis, thickening of the sclera, loss of corneal endothelial cells, and stiffening of the lens. Changes in the posterior segment include lowered viscoelasticity of the vitreous body, photoreceptor cell loss, and drusen deposition at the macula and fovea. Age-related ocular pathologies including glaucoma, cataracts, and age-related macular degeneration are largely mediated by oxidative stress. The prevalence of these diseases is expected to increase in the coming years, highlighting the need to develop new therapies that address oxidative stress and slow the progression of age-related pathologies.

Keywords:  age; age-related; eye; oxidative stress; reactive oxygen species

DOI:  https://doi.org/10.3390/life13030837
bioRxiv. 2023 Mar 14. pii: 2023.03.14.532586. [Epub ahead of print]

Transcriptomic changes predict metabolic alterations in LC3 associated phagocytosis in aged mice.

Anuradha Dhingra, John W Tobias, Kathleen Boesze-Battaglia.

LC3b ( Map1lc3b ) plays an essential role in canonical autophagy and is one of several components of the autophagy machinery that mediates non-canonical autophagic functions. Phagosomes are often associated with lipidated LC3b, to promote phagosome maturation in a process called LC3-associated phagocytosis (LAP). Specialized phagocytes such as mammary epithelial cells, retinal pigment epithelial (RPE) cells, and sertoli cells utilize LAP for optimal degradation of phagocytosed material, including debris. In the visual system, LAP is critical to maintain retinal function, lipid homeostasis and neuroprotection. In a mouse model of retinal lipid steatosis - mice lacking LC3b ( LC3b -/- ), we observed increased lipid deposition, metabolic dysregulation and enhanced inflammation. Herein we present a non-biased approach to determine if loss of LAP mediated processes modulate the expression of various genes related to metabolic homeostasis, lipid handling, and inflammation. A comparison of the RPE transcriptome of WT and LC3b -/- mice revealed 1533 DEGs, with âˆ¼73% up-regulated and 27% down-regulated. Enriched gene ontology (GO) terms included inflammatory response (up-regulated DEGs), fatty acid metabolism and vascular transport (down-regulated DEGs). Gene set enrichment analysis (GSEA) identified 34 pathways; 28 were upregulated (dominated by inflammation/related pathways) and 6 were downregulated (dominated by metabolic pathways). Analysis of additional gene families identified significant differences for genes in the solute carrier family, RPE signature genes, and genes with potential role in age-related macular degeneration. These data indicate that loss of LC3b induces robust changes in the RPE transcriptome contributing to lipid dysregulation and metabolic imbalance, RPE atrophy, inflammation, and disease pathophysiology.

DOI: https://doi.org/10.1101/2023.03.14.532586
J Vis Exp. 2023 Mar 10.

A Protocol to Evaluate and Quantify Retinal Pigmented Epithelium Pathologies in Mouse Models of Age-Related Macular Degeneration.

Michael Landowski, Samuel Grindel, Ying Hao, Sakae Ikeda, Catherine Bowes Rickman, Akihiro Ikeda.

Age-related macular degeneration (AMD) is a debilitating retinal disorder in aging populations. It is widely believed that dysfunction of the retinal pigmented epithelium (RPE) is a key pathobiological event in AMD. To understand the mechanisms that lead to RPE dysfunction, mouse models can be utilized by researchers. It has been established by previous studies that mice can develop RPE pathologies, some of which are observed in the eyes of individuals diagnosed with AMD. Here, we describe a phenotyping protocol to assess RPE pathologies in mice. This protocol includes the preparation and evaluation of retinal cross-sections using light microscopy and transmission electron microscopy, as well as that of RPE flat mounts by confocal microscopy. We detail the common types of murine RPE pathologies observed by these techniques and ways to quantify them through unbiased methods for statistical testing. As proof of concept, we use this RPE phenotyping protocol to quantify the RPE pathologies observed in mice overexpressing transmembrane protein 135 (Tmem135) and aged wild-type C57BL/6J mice. The main goal of this protocol is to present standard RPE phenotyping methods with unbiased quantitative assessments for scientists using mouse models of AMD.

DOI: https://doi.org/10.3791/64927
Antioxidants (Basel). 2023 Mar 01. pii: 602. [Epub ahead of print]12(3):

Mitochondrial Oxidative Stress and Mitophagy Activation Contribute to TNF-Dependent Impairment of Myogenesis.

Daniil A Chernyavskij, Olga Yu Pletjushkina, Anastasia V Kashtanova, Ivan I Galkin, Anna Karpukhina, Boris V Chernyak, Yegor S Vassetzky, Ekaterina N Popova.

  Many muscular pathologies are associated with oxidative stress and elevated levels of the tumor necrosis factor (TNF) that cause muscle protein catabolism and impair myogenesis. Myogenesis defects caused by TNF are mediated in part by reactive oxygen species (ROS), including those produced by mitochondria (mitoROS), but the mechanism of their pathological action is not fully understood. We hypothesized that mitoROS act by triggering and enhancing mitophagy, an important tool for remodelling the mitochondrial reticulum during myogenesis. We used three recently developed probes-MitoTracker Orange CM-H2TMRos, mito-QC, and MitoCLox-to study myogenesis in human myoblasts. Induction of myogenesis resulted in a significant increase in mitoROS generation and phospholipid peroxidation in the inner mitochondrial membrane, as well as mitophagy enhancement. Treatment of myoblasts with TNF 24 h before induction of myogenesis resulted in a significant decrease in the myoblast fusion index and myosin heavy chain (MYH2) synthesis. TNF increased the levels of mitoROS, phospholipid peroxidation in the inner mitochondrial membrane and mitophagy at an early stage of differentiation. Trolox and SkQ1 antioxidants partially restored TNF-impaired myogenesis. The general autophagy inducers rapamycin and AICAR, which also stimulate mitophagy, completely blocked myogenesis. The autophagy suppression by the ULK1 inhibitor SBI-0206965 partially restored myogenesis impaired by TNF. Thus, suppression of myogenesis by TNF is associated with a mitoROS-dependent increase in general autophagy and mitophagy.

Keywords:  SkQ1; TNF; antioxidant; mitochondria; mitophagy; myogenesis; reactive oxygen species (ROS)

DOI:  https://doi.org/10.3390/antiox12030602
Free Radic Biol Med. 2023 Mar 27. pii: S0891-5849(23)00130-2. [Epub ahead of print]

Mitochondrial GRIM-19 loss in parietal cells promotes spasmolytic polypeptide-expressing metaplasia through NLR family pyrin domain-containing 3 (NLRP3)-mediated IL-33 activation via a reactive oxygen species (ROS) -NRF2- Heme oxygenase-1(HO-1)-NF-кB axis.

Xin Zeng, Meihua Yang, Tingbo Ye, Jinmei Feng, Xiaohui Xu, Huaan Yang, Xin Wang, Liming Bao, Rui Li, Bingqian Xue, Jinbao Zang, Yi Huang.

  Spasmolytic polypeptide-expressing metaplasia (SPEM), as a pre-neoplastic precursor of intestinal metaplasia (IM), plays critical roles in the development of chronic atrophic gastritis (CAG) and gastric cancer (GC). However, the pathogenetic targets responsible for the SPEM pathogenesis remain poorly understood. Gene associated with retinoid-IFN-induced mortality 19 (GRIM-19), an essential subunit of the mitochondrial respiratory chain complex I, was progressively lost along with malignant transformation of human CAG, little is known about the potential link between GRIM-19 loss and CAG pathogenesis. Here, we show that lower GRIM-19 is associated with higher NF-кB RelA/p65 and NLR family pyrin domain-containing 3 (NLRP3) levels in CAG lesions. Functionally, GRIM-19 deficiency fails to drive direct differentiation of human GES-1 cells into IM or SPEM-like cell lineages in vitro, whereas parietal cells (PCs)-specific GRIM-19 knockout disturbs gastric glandular differentiation and promotes spontaneous gastritis and SPEM pathogenesis without intestinal characteristics in mice. Mechanistically, GRIM-19 loss causes chronic mucosal injury and aberrant NRF2 (Nuclear factor erythroid 2-related factor 2)- HO-1 (Heme oxygenase-1) activation via reactive oxygen species (ROS)-mediated oxidative stress, resulting in aberrant NF-кB activation by inducing p65 nuclear translocation via an IKK/IкB partner, while NRF2-HO-1 activation contributes to GRIM-19 loss-driven NF-кB activation via a positive feedback NRF2-HO-1 loop. Furthermore, GRIM-19 loss did not cause obvious PCs loss but triggers NLRP3 inflammasome activation in PCs via a ROS-NRF2-HO-1-NF-кB axis, leading to NLRP3-dependent IL-33 expression, a key mediator for SPEM formation. Moreover, intraperitoneal administration of NLRP3 inhibitor MCC950 drastically attenuates GRIM-19 loss-driven gastritis and SPEM in vivo. Our study suggests that mitochondrial GRIM-19 maybe a potential pathogenetic target for the SPEM pathogenesis, and its deficiency promotes SPEM through NLRP3/IL-33 pathway via a ROS-NRF2-HO-1-NF-кB axis. This finding not only provides a causal link between GRIM-19 loss and SPEM pathogenesis, but offers potential therapeutic strategies for the early prevention of intestinal GC.

Keywords:  Chronic atrophic gastritis (CAG); GRIM-19; IL-33; NLRP3 inflammasome; SPEM

DOI:  https://doi.org/10.1016/j.freeradbiomed.2023.03.024
Genes (Basel). 2023 Feb 24. pii: 566. [Epub ahead of print]14(3):

Reduced OPA1, Mitochondrial Fragmentation and Increased Susceptibility to Apoptosis in Granular Corneal Dystrophy Type 2 Corneal Fibroblasts.

Seung-Il Choi, Ga-Hyun Lee, Jong-Hwan Woo, Ikhyun Jun, Eung Kweon Kim.

  The progressive degeneration of granular corneal dystrophy type 2 (GCD2) corneal fibroblasts is associated with altered mitochondrial function, but the underlying mechanisms are incompletely understood. We investigated whether an imbalance of mitochondrial dynamics contributes to mitochondrial dysfunction of GCD2 corneal fibroblasts. Transmission electron microscopy revealed several small, structurally abnormal mitochondria with altered cristae morphology in GCD2 corneal fibroblasts. Confocal microscopy showed enhanced mitochondrial fission and fragmented mitochondrial tubular networks. Western blotting revealed higher levels of MFN1, MFN2, and pDRP1 and decreased levels of OPA1 and FIS1 in GCD2. OPA1 reduction by short hairpin RNA (shRNA) resulted in fragmented mitochondrial tubular networks and increased susceptibility to mitochondrial stress-induced apoptosis. A decrease in the mitochondrial biogenesis-related transcription factors NRF1 and PGC1α was observed, while there was an increase in the mitochondrial membrane proteins TOM20 and TIM23. Additionally, reduced levels of mitochondrial DNA (mtDNA) were exhibited in GCD2 corneal fibroblasts. These observations suggest that altered mitochondrial fission/fusion and biogenesis are the critical molecular mechanisms that cause mitochondrial dysfunction contributing to the degeneration of GCD2 corneal fibroblasts.

Keywords:  NRF1; OPA1; PGC1α; corneal fibroblasts; fission and fusion; granular corneal dystrophy type 2; mitochondria

DOI:  https://doi.org/10.3390/genes14030566