Neuronal and glial cell alterations involved in the retinal degeneration of the familial dysautonomia optic neuropathy

• Published in: Glia 2024-12, Vol.72 (12), p.2268-2294
• Main Authors: Schultz, Anastasia, Albertos‐Arranz, Henar, Sáez, Xavier Sánchez, Morgan, Jamie, Darland, Diane C., Gonzalez‐Duarte, Alejandra, Kaufmann, Horacio, Mendoza‐Santiesteban, Carlos E., Cuenca, Nicolás, Lefcort, Frances
• Format: Article
• Language: English
• Subjects: Astrocytes; Autonomic nervous system; Autopsy; Cell death; cell stress; Cell survival; Death; Degeneration; Disruption; Dysautonomia; Endothelial cells; familial dysautonomia; Glial cells; Gliosis; Homeostasis; Microglia; Mortality; Mueller cells; Neurodegeneration; Neurodegenerative diseases; Neurodevelopmental disorders; Neuronal-glial interactions; neurovascular unit; Optic neuropathy; Pathology; Pax6 protein; Peripheral neuropathy; Quality of life; Retina; Retinal ganglion cells; Sensory properties; Therapeutic applications
• ISSN: 0894-1491; 1098-1136; 1098-1136
• DOI: 10.1002/glia.24612

Familial dysautonomia (FD) is a rare genetic neurodevelopmental and neurodegenerative disorder. In addition to the autonomic and peripheral sensory neuropathies that challenge patient survival, one of the most debilitating symptoms affecting patients' quality of life is progressive blindness resulting from the steady loss of retinal ganglion cells (RGCs). Within the FD community, there is a concerted effort to develop treatments to prevent the loss of RGCs. However, the mechanisms underlying the death of RGCs are not well understood. To study the mechanisms underlying RGC death, Pax6‐cre;Elp1loxp/loxp male and female mice and postmortem retinal tissue from an FD patient were used to explore the neuronal and non‐neuronal cellular pathology associated with the FD optic neuropathy. Neurons, astrocytes, microglia, Müller glia, and endothelial cells were investigated using a combination of histological analyses. We identified a novel disruption of cellular homeostasis and gliosis in the FD retina. Beginning shortly after birth and progressing with age, the FD retina is marked by astrogliosis and perturbations in microglia, which coincide with vascular remodeling. These changes begin before the onset of RGC death, suggesting alterations in the retinal neurovascular unit may contribute to and exacerbate RGC death. We reveal for the first time that the FD retina pathology includes reactive gliosis, increased microglial recruitment to the ganglion cell layer (GCL), disruptions in the deep and superficial vascular plexuses, and alterations in signaling pathways. These studies implicate the neurovascular unit as a disease‐modifying target for therapeutic interventions in FD. Main Points Retinal vasculature and glial cell alterations precede the death of retinal ganglion cells in the Elp1‐deleted retina. Disruptions of the neurovascular unit (NVU) in the FD retina may exacerbate the diseased retinal state.