bims-mideyd 2024-06-02 papers

J Biomed Res. 2024 Apr 25. 1-12

RNA-sequencing expression profile and functional analysis of retinal pigment epithelium in atrophic age-related macular degeneration.

Miao Xu, Yan Gao, Wenjie Yin, Qinghuai Liu, Songtao Yuan.

The retinal pigment epithelium (RPE) is fundamental to sustaining retinal homeostasis. RPE abnormality leads to visual defects and blindness, including age-related macular degeneration (AMD). Although breakthroughs have been made in the treatment of neovascular AMD, effective intervention for atrophic AMD is largely absent. The inadequate knowledge of RPE pathology is hindered by a lack of patient RPE datasets, especially at the single-cell resolution. In this study, we delved into a large-scale single-cell resource of AMD donors in which RPE cells were occupied in a substantial proportion. Bulk RNA-seq datasets of atrophic AMD were integrated to extract molecular characteristics of RPE in the pathogenesis of atrophic AMD. Both in vivo and in vitro models revealed that carboxypeptidase X, M14 family member 2 (CPXM2) was specifically expressed in the RPE cells of atrophic AMD, which might be induced by oxidative stress and involved in the epithelial-mesenchymal transition of RPE cells. Additionally, silencing of CPXM2 inhibited the mesenchymal phenotype of RPE cells in an oxidative stress cell model. Thus, our results demonstrate that CPXM2 plays a crucial role in regulating atrophic AMD and may serve as a potential therapeutic target for atrophic AMD.

Keywords: age-related macular degeneration; bioinformatics analysis; high-throughput RNA-sequencing; retinal pigment epithelium

DOI: https://doi.org/10.7555/JBR.37.20230320

Adv Sci (Weinh). 2024 May 30. e2400230

Polydopamine Nanoparticles as Mimicking RPE Melanin for the Protection of Retinal Cells Against Blue Light-Induced Phototoxicity.

Yong-Su Kwon, Julie Munsoor, Mary Kaufmann, Min Zheng, Alex I Smirnov, Zongchao Han.

Exposure of the eyes to blue light can induce the overproduction of reactive oxygen species (ROS) in the retina and retinal pigment epithelium (RPE) cells, potentially leading to pathological damage of age-related macular degeneration (AMD). While the melanin in RPE cells absorbs blue light and prevents ROS accumulation, the loss and dysfunction of RPE melanin due to age-related changes may contribute to photooxidation toxicity. Herein, a novel approach utilizing a polydopamine-replenishing strategy via a single-dose intravitreal (IVT) injection is presented to protect retinal cells against blue light-induced phototoxicity. To investigate the effects of overexposure to blue light on retinal cells, a blue light exposure Nrf2-deficient mouse model is created, which is susceptible to light-induced retinal lesions. After blue light irradiation, retina degeneration and an overproduction of ROS are observed. The polydopamine-replenishing strategy demonstrated effectiveness in maintaining retinal structural integrity and preventing retina degeneration by reducing ROS production in retinal cells and limiting the phototoxicity of blue light exposure. These findings highlight the potential of polydopamine as a simple and effective replenishment for providing photoprotection against high-energy blue light exposure.

Keywords: age‐related macular degeneration; antioxidant; blue light‐induced phototoxicity; polydopamine nanoparticles; reactive oxygen species

DOI: https://doi.org/10.1002/advs.202400230

bioRxiv. 2024 May 14. pii: 2024.05.14.594013. [Epub ahead of print]

Decreased CREB phosphorylation impairs embryonic retinal neurogenesis in the Oa1-/- mouse model of Ocular albinism.

Sonia Guha, Andrew M Nguyen, Alejandra Young, Ethan Mondell, Debora B Farber.

Mutations in the human Ocular albinism type-1 gene OA1 are associated with abnormal retinal pigment epithelium (RPE) melanogenesis and poor binocular vision resulting from misrouting of ipsilateral retinal ganglion cell (iRGC) axons to the brain. We studied the latter using wild-type (WT) and Oa1-/- mouse eyes. At embryonic stages, the WT RPE-specific Oa1 protein signals through cAMP/Epac1-Erk2-CREB. Following CREB phosphorylation, a pCREB gradient extends from the RPE to the differentiating retinal amacrine and RGCs. In contrast to WT, the Oa1-/- RPE and ventral ciliary-margin-zone, a niche for iRGCs, express less pCREB while their retinas have a disrupted pCREB gradient, indicating Oa1's involvement in pCREB maintenance. Oa1-/- retinas also show hyperproliferation, enlarged nuclei, reduced differentiation, and fewer newborn amacrine and RGCs than WT retinas. Our results demonstrate that Oa1's absence leads to reduced binocular vision through a hyperproliferation-associated block in differentiation that impairs neurogenesis. This may affect iRGC axon's routing to the brain.

DOI: https://doi.org/10.1101/2024.05.14.594013

Clin Interv Aging. 2024 ;19 939-951

Cunzi Li, Lan Zhou, Hongyan Sun, Ming Ming Yang.

Age-related macular degeneration (AMD) is a degenerative ocular disease primarily affecting central vision in the elderly. Its pathogenesis is complex, involving cellular senescence and immune homeostasis dysregulation. This review investigates the interaction between these two critical biological processes in AMD pathogenesis and their impact on disease progression. Initially, cellular senescence is analyzed, with particular emphasis on retinal damage induced by senescent retinal pigment epithelial cells. Subsequently, the occurrence of immune homeostasis dysregulation within the retina and its mechanistic role in AMD areis explored. Furthermore, the paper also discusses in detail the interplay between cellular senescence and immune responses, forming a vicious cycle that exacerbates retinal damage and may influence treatment outcomes. In summary, a deeper understanding of the interrelation between cellular senescence and immune dysregulation is vital for the developing innovative therapeutic strategies for AMD.

Keywords: age-related macular degeneration; cellular senescence; immune homeostasis dysregulation

DOI: https://doi.org/10.2147/CIA.S463297