Discoveries in Retina Physiology and Disease Biology Using Single-Cell RNA Sequencing.

The retina, a component of the central nervous system, is composed of six distinct neuronal types and various types of glial cells. A technique for single-cell transcriptome analysis called single-cell RNA sequencing (scRNA-seq) can be employed to study the complicated dynamics of several types of retinal cells. It meticulously examines how various cell types express their genes, shedding light on all biological processes. scRNA-seq is an alternative to regular RNA-seq, which cannot identify cellular heterogeneity. Understanding retinal diseases requires research on retinal cell heterogeneity. The identification of novel cell subpopulations can provide information about disease occurrence and progression as well as the specific biological functions of particular cells. We currently have a better understanding of the interactions among the brain, the retina, and its visual pathways thanks to the use of scRNA-seq to examine retinal development and disease pathogenesis. Additionally, this technology offers fresh perspectives on the sensitivity and molecular basis of cell subtypes linked to retinal diseases. Thanks to scRNA-seq technology, we now have a better understanding of the most recent developments and difficulties in retinal development and disorders. We believe that scRNA-seq is an important tool for developing cutting-edge treatments for retinal diseases. This paper presents a systematic review of the history of sRNA-seq technology development and provides an overview of the unique subtypes of retinal cells and the specific gene markers this technology identifies.

[The protective effects on the function and structure of retinae in diabetic rats by intravitreal injection of cyclosporin A].

OBJECTIVE: To investigate the electrophysiological and morphological changes of retinae after intravitreal injection of cyclosporin A (CsA) in experimental diabetic rats. METHODS: Experimental study. SD diabetic mellitus (DM) rat models were induced with intraperitoneal injection of streptozotocin. The rats were divided into four groups, with 9 rats in each group:the normal control (group CON), the diabetic rats with or without CsA intravitreal injection respectively (group DM + CsA and group DM), and the diabetic rats with dimethyl sulfoxide (DMSO) intravitreal injection (group DM + DMSO). The intravitreal injection of CsA or contrast solution was performed 4 weeks after the modeling. The retinal function of rats was examined by electroretinogram (ERG) 48 hours after the intravitreal injection. All rats were sacrificed and the structural changes of retina were observed by optical and transmission electron microscope. The datas of ERG including amplitudes and latencies of a-wave and b-wave were analyzed by One-way ANOVA and Bonferroni post hoc test. RESULTS: There was difference in ERG b-wave among the 4 groups under different stimuli light intensity (F = 14.760 - 28.890, all P value < 0.01). And there was difference in ERG a-wave among the 4 groups when the stimuli light intensity ≥ -0.35 log cd×s×m(-2) (F = 12.510, 15.500, both P value < 0.01). Comparing to the group CON (ERG a-wave: 82.43 ± 26.68, ERG b-wave: 208.40 ± 51.20), the ERG a-wave and b-wave amplitudes of group DM (ERG a-wave: 39.71 ± 7.61, ERG b-wave: 92.20 ± 24.42) and group DM + DMSO (ERG a-wave: 37.63 ± 17.25, ERG b-wave: 93.11 ± 22.50)(t = 5.448 - 7.872, all P value < 0.05), and the ERG b-wave of group DM + CsA (160.10 ± 43.39) (t = 3.299, P < 0.05) were declined in dark adaptation, while the ERG a-wave (63.91 ± 20.32) of group DM ± CsA had no difference (P > 0.05). The a-wave and b-wave amplitudes of group DM + CsA were significantly increased compared to the other two groups in dark adaptation (t = 3.203 - 4.759, both P < 0.05). Under optical microscope, group DM, DM + DMSO and DM + CsA had outer nuclear layer (ONL) disorder. Under transmission electron microscope, there were ultrastructure changes of the three groups. Furthermore, the ONL disorder and ultrastructure changes of group DM + CsA were less severe than the other two groups. CONCLUSIONS: Functional and morphological changes are evident in the early stages in DM rats. Intravitreal injection with CsA shows protective effects on the nerve function in DM retina.