Early phosphoproteomic changes in the retina following optic nerve crush

Phosphoregulation of the septin cytoskeleton in neuronal development and disease

Septins are highly conserved GTP-binding proteins that oligomerize and form higher order structures. The septin cytoskeleton plays an important role in cellular organization, intracellular transport, and cytokinesis. Kinase-mediated phosphorylation of septins regulates various aspects of their function, localization, and dynamics. Septins are enriched in the mammalian nervous system where they contribute to neurodevelopment and neuronal function. Emerging research has implicated aberrant changes in septin cytoskeleton in several human diseases. The mechanisms through which aberrant phosphorylation by kinases contributes to septin dysfunction in neurological disorders are poorly understood and represent an important question for future research with therapeutic implications. This review summarizes the current state of knowledge of the diversity of kinases that interact with and phosphorylate mammalian septins, delineates how phosphoregulation impacts septin dynamics, and describes how aberrant septin phosphorylation contributes to neurological disorders.

Mass spectrometry-based retina proteomics

A subfield of neuroproteomics, retina proteomics has experienced a transformative growth since its inception due to methodological advances in enabling chemical, biochemical, and molecular biology techniques. This review focuses on mass spectrometry's contributions to facilitate mammalian and avian retina proteomics to catalog and quantify retinal protein expressions, determine their posttranslational modifications, as well as its applications to study the proteome of the retina in the context of biology, health and diseases, and therapy developments.

Posttranslational modifications of proteins in diseased retina

Posttranslational modifications (PTMs) are known to constitute a key step in protein biosynthesis and in the regulation of protein functions. Recent breakthroughs in protein purification strategies and current proteome technologies make it possible to identify the proteomics of healthy and diseased retinas. Despite these advantages, the research field identifying sets of posttranslationally modified proteins (PTMomes) related to diseased retinas is significantly lagging, despite knowledge of the major retina PTMome being critical to drug development. In this review, we highlight current updates regarding the PTMomes in three retinal degenerative diseases-namely, diabetic retinopathy (DR), glaucoma, and retinitis pigmentosa (RP). A literature search reveals the necessity to expedite investigations into essential PTMomes in the diseased retina and validate their physiological roles. This knowledge would accelerate the development of treatments for retinal degenerative disorders and the prevention of blindness in affected populations.

Gadolinium chloride protects neurons by regulating the activation of microglia in the model of optic nerve crush

The pathological basis of optic nerve crush (ONC) is the apoptosis of retinal ganglion cells (RGCs), which leads to an irreversible impairment of visual function. When stimulated by external stimuli, microglia polarize into different types and play different roles in repairing retinal injury. In this study, gadolinium chloride (GdCl₃) could inhibit the excessive proliferation and activation of microglia in the retina after ONC and significantly inhibited the morphological changes of microglia in the ganglion cell layer (GCL) and inner plexiform layer (IPL). In the early stage of optic nerve injury, blood-derived immune cells did not play an essential role in retinal repair. In addition, transcriptome analysis showed that GdCl₃ inhibited the expression of microglia proliferation-related factors and regulated signaling pathways related to skeletonization and inflammation. After GdCl₃ treatment, M1 markers were significantly down-regulated, while M2 markers were increased. In conclusion, this study demonstrated that GdCl₃ could regulate the distribution and morphological change of the retinal microglia and protect the ganglion cells by eliminating M1 microglia selectively, which provided a theoretical basis for further localizing different types of microglia in retina related diseases.