methanol-based-whole-mount-preparation-for-investigation-retinal

Methanol-Based Whole-Mount Preparation for the Investigation of Retinal Ganglion Cells

Retinal ganglion cells (RGCs), which are the projection neurons of the retina, propagate external visual information to the brain. Pathological changes in ...

Renmin hospital of Wuhan university

Retinal ganglion cells (RGCs) are essential to propagate external visual information from the retina to the brain. Death of RGCs is speculated to be closely correlated with blinding retinal diseases, such as glaucoma and traumatic optic neuropathy (TON). Emerging innovative technologies have helped refine and standardize the classification of RGCs; at present, they are classified into more than 40 subpopulations in mammals. These RGC subtypes are identified by a combination of anatomical morphologies, electrophysiological functions, and genetic profiles. Increasing evidence suggests that neurodegenerative diseases do not collectively affect the RGCs. In fact, which RGC subtype exhibits the strongest or weakest susceptibility is hotly debated. Although a consensus has not yet been reached, it is certain that assorted RGCs display differential susceptibility against irreversible degeneration. Interestingly, a single RGC subtype can exhibit various vulnerabilities to optic nerve damage in diverse injury models. Thus, elucidating how susceptible RGC subtypes are to various injuries can protect vulnerable RGCs from damage and improve the possibility of preventing and treating visual impairment caused by neurodegenerative diseases. In this review, we summarize in detail the progress and status quo of research on the type-specific susceptibility of RGCs and point out current limitations and the possible directions for future research in this field.

Differential susceptibility of retinal ganglion cell subtypes against neurodegenerative diseases.

Experimental studies on retinal vasculature and retinal ganglion cells (RGCs) investigating the developmental and pathological conditions of the retina mainly rely on whole-mount retinal immunostaining. Methanol, an auxiliary fixed medium for retinal whole-mount preparations, has been used in some studies; however, its application in short- and long-term storage of retinas for further study has not been well described. We aimed to evaluate methanol use as a preservation treatment for further immunostaining of the retina.

Using methanol to preserve retinas for immunostaining.

Traumatic optic neuropathy or other neurodegenerative diseases, including optic nerve transection, glaucoma, and diabetic retinopathy, can lead to progressive and irreversible visual damage. Long non-coding RNAs (lncRNAs), which belong to the family of non-protein-coding transcripts, have been linked to the pathogenesis, progression, and prognosis of these lesions. Retinal ganglion cells (RGCs) are critical for the transmission of visual information to the brain, damage to which results in visual loss. Apoptosis has been identified as one of the most essential modes of RGC death. Emerging evidence suggests that lncRNAs can regulate RGC degeneration by directly or indirectly modulating apoptosis-associated signaling pathways. This review presents a comprehensive overview of the role of lncRNAs in RGC apoptosis at transcriptional, post-transcriptional, translational, and post-translational levels, emphasizing on the potential mechanisms of action. The current limitations and future perspectives of exploring the connection between lncRNAs and RGC apoptosis have been summarized. Understanding the intricate molecular interaction network of lncRNAs and RGC apoptosis will open new avenues for the identification of novel diagnostic biomarkers, therapeutic targets, and molecules for prognostic evaluation of diseases related to RGC injury.

Long Non-Coding RNAs in Retinal Ganglion Cell Apoptosis.

Ocular diseases affect multiple eye parts and can be caused by pathogenic infections, complications of systemic diseases, genetics, environment, and old age. Understanding the etiology and pathogenesis of eye diseases and improving their diagnosis and treatment are critical for preventing any adverse consequences of these diseases. Recently, the advancement of high-throughput sequencing (HTS) technology has paved wide prospects for identifying the pathogenesis, signaling pathways, and biomarkers involved in eye diseases. Due to the advantages of HTS in nucleic acid sequence recognition, HTS has not only identified several normal ocular surface microorganisms but has also discovered many pathogenic bacteria, fungi, parasites, and viruses associated with eye diseases, including rare pathogens that were previously difficult to identify. At present, HTS can directly sequence RNA, which will promote research on the occurrence, development, and underlying mechanism of eye diseases. Although HTS has certain limitations, including low effectiveness, contamination, and high cost, it is still superior to traditional diagnostic methods for its efficient and comprehensive diagnosis of ocular diseases. This review summarizes the progress of the application of HTS in ocular diseases, intending to explore the pathogenesis of eye diseases and improve their diagnosis.

Application Progress of High-Throughput Sequencing in Ocular Diseases.

Retinal neovascularization (RNV) is an intractable pathological hallmark of numerous ocular blinding diseases, including diabetic retinopathy, retinal vein occlusion, and retinopathy of prematurity. However, current therapeutic methods have potential side effects and limited efficacy. Thus, further studies on the pathogenesis of RNV-related disorders and novel therapeutic targets are critically required. Long non-coding RNAs (lncRNAs) have various functions and participate in almost all biological processes in living cells, such as translation, transcription, signal transduction, and cell cycle control. In addition, recent research has demonstrated critical modulatory roles of various lncRNAs in RNV. In this review, we summarize current knowledge about the expression and regulatory functions of lncRNAs related to the progression of pathological RNV.

Long non-coding RNAs in retinal neovascularization: current research and future directions.

Submacular hemorrhage (SMH) is the accumulation of blood in the macular area that can severely damage the macular structure and visual function. Recently, the intraocular administration of tissue plasminogen activator (TPA) with anti-vascular endothelial growth factor (anti-VEGF) drugs was reported to have a positive effect on SMH. This meta-analysis aimed to explore the efficacy and safety of the drug combination. We systematically searched the Web of Science, MEDLINE, EMBASE, and Cochrane Library databases and screened relevant full-length literature reports. The quality of the reports was assessed by two independent reviewers. The best-corrected visual acuity (BCVA) and foveal thickness (FT) were considered the main indicators of efficacy. RevMan 5.4 software was used for this meta-analysis. Twelve studies were analyzed, and the results showed that BCVA at 1 month ( < 0.001), 3 months ( < 0.001), 6 months ( < 0.001), and the last follow-up ( < 0.001) was improved relative to the preoperative value. The postoperative FT was lower than the preoperative FT ( < 0.001). No significant difference in efficacy was observed between subretinal and intravitreal TPA injections ( = 0.37). TPA with anti-VEGF drugs is safe for SMH treatment and can significantly improve BCVA and reduce FT.

Efficacy Evaluation of Tissue Plasminogen Activator with Anti-Vascular Endothelial Growth Factor Drugs for Submacular Hemorrhage Treatment: A Meta-Analysis.

Ningzhi Zhang

Department of Ophthalmology

Renmin hospital of Wuhan university

Methanol-Based Whole-Mount Preparation for the Investigation of Retinal Ganglion Cells