Deletion of the Wolfram syndrome-related gene Wfs1 results in increased sensitivity to ethanol in female mice

MCT1-dependent energetic failure and neuroinflammation underlie optic nerve degeneration in Wolfram syndrome mice

Wolfram syndrome 1 (WS1) is a rare genetic disorder caused by mutations in the WFS1 gene leading to a wide spectrum of clinical dysfunctions, among which blindness, diabetes, and neurological deficits are the most prominent. WFS1 encodes for the endoplasmic reticulum (ER) resident transmembrane protein wolframin with multiple functions in ER processes. However, the WFS1-dependent etiopathology in retinal cells is unknown. Herein, we showed that Wfs1 mutant mice developed early retinal electrophysiological impairments followed by marked visual loss. Interestingly, axons and myelin disruption in the optic nerve preceded the degeneration of the retinal ganglion cell bodies in the retina. Transcriptomics at pre-degenerative stage revealed the STAT3-dependent activation of proinflammatory glial markers with reduction of the homeostatic and pro-survival factors glutamine synthetase and BDNF. Furthermore, label-free comparative proteomics identified a significant reduction of the monocarboxylate transport isoform 1 (MCT1) and its partner basigin that are highly enriched on retinal glia and myelin-forming oligodendrocytes in optic nerve together with wolframin. Loss of MCT1 caused a failure in lactate transfer from glial to neuronal cell bodies and axons leading to a chronic hypometabolic state. Thus, this bioenergetic impairment is occurring concurrently both within the axonal regions and cell bodies of the retinal ganglion cells, selectively endangering their survival while impacting less on other retinal cells. This metabolic dysfunction occurs months before the frank RGC degeneration suggesting an extended time-window for intervening with new therapeutic strategies focused on boosting retinal and optic nerve bioenergetics in WS1.

Psychiatric Diagnoses and Medications in Wolfram Syndrome

Background

Wolfram Syndrome is a rare genetic disorder usually resulting from pathogenic variation in the WFS1 gene, which leads to an exaggerated endoplasmic reticulum (ER) stress response. The disorder is typically characterized by diabetes insipidus, diabetes mellitus, optic nerve atrophy, hearing loss, and neurodegenerative features. Existing literature suggests it may also have psychiatric manifestations.

Objective

To examine lifetime psychiatric diagnoses and medication history in Wolfram Syndrome.

Method

Child, adolescent, and young adult Wolfram Syndrome participants (n=39) were assessed by a child & adolescent psychiatrist to determine best estimate DSM-5 lifetime psychiatric diagnoses as well as psychoactive medication history. In addition, the Child & Adolescent Symptom Inventory-5 (CASI-5) Parent Checklist was used to determine likely psychiatric diagnoses based on symptom counts in Wolfram Syndrome patients (n=33), type 1 diabetes (n=15), and healthy comparison (n=18) groups.

Results

Study participants with Wolfram Syndrome had high lifetime rates of anxiety disorders (77%). Also, 31% had an obsessive-compulsive spectrum disorder, 33% had a mood disorder, 31% had a neurodevelopmental or disruptive behavior disorder, and 31% had a sleep-wake disorder. More than half of Wolfram Syndrome participants had taken at least one psychoactive medication, and one third had taken at least one selective serotonin reuptake inhibitor (SSRI). Some individuals reported poor response to sertraline but better response after switching to another SSRI (fluoxetine or citalopram). In general, people with Wolfram Syndrome often reported benefit from psychotherapy and/or commonly used psychoactive medications appropriate for their psychiatric diagnoses.

Conclusions

Wolfram Syndrome may be associated with elevated risk for anxiety and obsessive-compulsive spectrum disorders, which seem generally responsive to usual treatments for these disorders.