bims-mideyd 2023-11-26 papers

Issue of 2023‒11‒26
four papers selected by
Rajalekshmy “Raji” Shyam, Indiana University Bloomington

Food Funct. 2023 Nov 22.

The protective effects of beta-mangostin against sodium iodate-induced retinal ROS-mediated apoptosis through MEK/ERK and p53 signaling pathways.

Yuan-Yen Chang, Meilin Wang, Jui-Hsuan Yeh, Shang-Chun Tsou, Tzu-Chun Chen, Min-Yen Hsu, Yi-Ju Lee, Inga Wang, Hui-Wen Lin.

Previous studies have indicated that NaIO3 induces intracellular reactive oxygen species (ROS) production and has been used as a model for age-related macular degeneration (AMD) due to the selective retinal pigment epithelium (RPE) cell damage it induces. Beta-mangostin (BM) is a xanthone-type natural compound isolated from Cratoxylum arborescens. The influence of BM on NaIO3-induced oxidative stress damage in ARPE-19 cells has not yet been elucidated. In this study, we investigated how BM protects ARPE-19 cells from NaIO3-induced ROS-mediated apoptosis. Our results revealed that BM notably improved cell viability and prevented ARPE-19 cell mitochondrial dysfunction mediated-apoptosis induced by NaIO3; it was mediated by significantly reduced NaIO3-upregulated ROS, cellular H2O2 production and improved downregulated glutathione and catalase activities. Furthermore, we found that BM could suppress the expression of Bax, cleaved PARP, and cleaved caspase-3 by decreasing phosphorylation of MEK/ERK and p53 expression in NaIO3-induced ARPE-19 cells. At the same time, we also used MEK inhibitors (PD98059) to confirm the above phenomenon. Moreover, our animal experiments revealed that BM prevented NaIO3 from causing retinal deformation; it led to thicker outer and inner nuclear layers and downregulated cleaved caspase-3 expression compared to the group receiving NaIO3 only. Collectively, these results suggest that BM can protect the RPE and retina from NaIO3-induced apoptosis through ROS-mediated mitochondrial dysfunction involving the MEK/ERK and p53 signaling pathways.

DOI: https://doi.org/10.1039/d3fo03568a

Cell Death Discov. 2023 Nov 18. 9(1): 419

Iron derived from NCOA4-mediated ferritinophagy causes cellular senescence via the cGAS-STING pathway.

Hong-Ying Li, Ting-Ting Wei, Miao Zhuang, Cheng-Ye Tan, Tian-Hua Xie, Jiping Cai, Yong Yao, Lingpeng Zhu.

Cellular senescence is a hallmark of aging and has been linked to age-related diseases. Age-related macular degeneration (AMD), the most common aging-related retinal disease, is prospectively associated with retinal pigment epithelial (RPE) senescence. However, the mechanism of RPE cell senescence remains unknown. In this study, tert-butyl hydroperoxide (TBH)-induced ARPE-19 cells and D-galactose-treated C57 mice were used to examine the cause of elevated iron in RPE cell senescence. Ferric ammonium citrate (FAC)-treated ARPE-19 cells and C57 mice were used to elucidated the mechanism of iron overload-induced RPE cell senescence. Molecular biology techniques for the assessment of iron metabolism, cellular senescence, autophagy, and mitochondrial function in vivo and in vitro. We found that iron level was increased during the senescence process. Ferritin, a major iron storage protein, is negatively correlated with intracellular iron levels and cell senescence. NCOA4, a cargo receptor for ferritinophagy, mediates degradation of ferritin and contributes to iron accumulation. Besides, we found that iron overload leads to mitochondrial dysfunction. As a result, mitochondrial DNA (mtDNA) is released from damaged mitochondria to cytoplasm. Cytoplasm mtDNA activates the cGAS-STING pathway and promotes inflammatory senescence-associated secretory phenotype (SASP) and cell senescence. Meanwhile, iron chelator Deferoxamine (DFO) significantly rescues RPE senescence and retinopathy induced by FAC or D-gal in mice. Taken together, these findings imply that iron derived from NCOA4-mediated ferritinophagy causes cellular senescence via the cGAS-STING pathway. Inhibiting iron accumulation may represent a promising therapeutic approach for age-related diseases such as AMD.

DOI: https://doi.org/10.1038/s41420-023-01712-7

Pharmaceutics. 2023 Nov 05. pii: 2590. [Epub ahead of print]15(11):

Targeting 7KCh-Induced Cell Death Response Mediated by p38, P2X7 and GSDME in Retinal Pigment Epithelium Cells with Sterculic Acid.

Ana Pariente, Rafael Peláez, Rodrigo Ochoa, Álvaro Pérez-Sala, Ángela Villanueva-Martínez, Miriam Bobadilla, Ignacio M Larráyoz.

Age-related macular degeneration (AMD) is the main cause of blindness in developed countries. AMD is characterized by the formation of drusen, which are lipidic deposits, between retinal pigment epithelium (RPE) and the choroid. One of the main molecules accumulated in drusen is 7-Ketocholesterol (7KCh), an oxidized-cholesterol derivative. It is known that 7KCh induces inflammatory and cytotoxic responses in different cell types and the study of its mechanism of action is interesting in order to understand the development of AMD. Sterculic acid (SA) counteracts 7KCh response in RPE cells and could represent an alternative to improve currently used AMD treatments, which are not efficient enough. In the present study, we determine that 7KCh induces a complex cell death signaling characterized by the activation of necrosis and an alternative pyroptosis mediated by P2X7, p38 and GSDME, a new mechanism not yet related to the response to 7KCh until now. On the other hand, SA treatment can successfully attenuate the activation of both necrosis and pyroptosis, highlighting its therapeutic potential for the treatment of AMD.

Keywords: 7-ketocholesterol; AMD; GSDME; P2X7; cell death; retina; sterculic acid

DOI: https://doi.org/10.3390/pharmaceutics15112590

Antioxidants (Basel). 2023 Nov 17. pii: 2011. [Epub ahead of print]12(11):

Targeting Mitochondrial Dysfunction and Oxidative Stress to Prevent the Neurodegeneration of Retinal Ganglion Cells.

Elisabetta Catalani, Kashi Brunetti, Simona Del Quondam, Davide Cervia.

The imbalance of redox homeostasis contributes to neurodegeneration, including that related to the visual system. Mitochondria, essential in providing energy and responsible for several cell functions, are a significant source of reactive oxygen and/or nitrogen species, and they are, in turn, sensitive to free radical imbalance. Dysfunctional mitochondria are implicated in the development and progression of retinal pathologies and are directly involved in retinal neuronal degeneration. Retinal ganglion cells (RGCs) are higher energy consumers susceptible to mitochondrial dysfunctions that ultimately cause RGC loss. Proper redox balance and mitochondrial homeostasis are essential for maintaining healthy retinal conditions and inducing neuroprotection. In this respect, the antioxidant treatment approach is effective against neuronal oxidative damage and represents a challenge for retinal diseases. Here, we highlighted the latest findings about mitochondrial dysfunction in retinal pathologies linked to RGC degeneration and discussed redox-related strategies with potential neuroprotective properties.

Keywords: ganglion cells; mitochondria; neurodegeneration; redox homeostasis; retina

DOI: https://doi.org/10.3390/antiox12112011