bioRxiv Science⌕ Search

bioRxiv · 10.1101/2024.05.30.596635

TMAO miscompartmentalization is a reversible driver of autism pathophysiology

Abstract

Autism spectrum disorder (ASD) is a complex and heterogeneous neurodevelopmental disorder. Contrary to what has been reported for genetics and gut dysbiosis, ASD appears to be very homogeneous when considering tryptophan metabolism. Indeed, multiple biochemical anomalies have been observed in most individuals with ASD. Following up on these findings, we found that ASD is strongly associated with the miscompartmentalization of the chemical chaperone trimethylamine N-oxide (TMAO). Intracellular TMAO was markedly reduced in individuals with ASD as a result of altered fluid/electrolyte homeostasis and was responsible for numerous biochemical anomalies described in ASD. Administration of urea in a rat model of ASD that recapitulates the biochemical anomalies observed in humans not only restored biochemical parameters but also broadly improved all behaviours. Our results demonstrate the major role of TMAO in the pathophysiology of ASD and cellular physiology, although TMAO miscompartmentalization is not causal for ASD. We anticipate that urea, which is already clinically approved, offers a breakthrough therapeutic opportunity for ASD.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Launay, J.-M., Vodovar, N.. 2024-06-03. TMAO miscompartmentalization is a reversible driver of autism pathophysiology. https://doi.org/10.1101/2024.05.30.596635

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

NAE1-Dependent Protein Neddylation Preserves Endothelial Identity and Vascular Integrity

Background: Endothelial dysfunction is a central driver of cardiovascular and inflammatory diseases, yet the post-translational mechanisms that preserve endothelial homeostasis remain incompletely understood. Protein neddylation, the covalent conjugation of a ubiquitin-like modifier, regulates diverse cellular processes, yet its physiological role in the vascular endothelium remains unknown. This study investigated whether protein neddylation is required to preserve endothelial identity and vascular homeostasis. Methods: We generated tamoxifen-inducible endothelial-specific Nae1 knockout mice to inhibit neddylation and combined bulk RNA sequencing, single-cell and single-nucleus transcriptomics, quantitative proteomics, biochemical analyses, and gain- and loss-of-function approaches to define the role of endothelial neddylation in vascular homeostasis and inflammatory injury. Results: Endothelial-specific Nae1 deletion caused rapid mortality associated with vascular leakage, platelet accumulation, inflammation, and multi-organ injury. Multi-omics analyses demonstrated profound loss of endothelial identity, characterized by suppression of core endothelial programs and activation of inflammatory, procoagulant, and pyroptotic pathways. Single-cell analyses revealed progressive endothelial dysfunction culminating in depletion of the endothelial population and remodeling of the vascular niche. Mechanistically, endothelial neddylation deficiency activated gasdermin D (GSDMD)- and gasdermin E (GSDME)-dependent pyroptosis, whereas dual inhibition of GSDMD and GSDME markedly attenuated inflammatory transcriptomic remodeling, vascular injury, hepatocyte death, immune cell infiltration, and platelet accumulation. Translational analyses demonstrated reduced endothelial neddylation in experimental endotoxemia and decreased expression of neddylation pathway components in human atherosclerosis and COVID-19 datasets. Conversely, restoration of endothelial neddylation partially reversed inflammatory endothelial transcriptomic reprogramming in vivo. Conclusions: NAE1-dependent protein neddylation is an essential regulator of endothelial identity and vascular integrity. Loss of endothelial neddylation promotes gasdermin-dependent pyroptosis and thrombo-inflammatory vascular injury, whereas restoration of the neddylation pathway mitigates inflammatory endothelial dysfunction. These findings identify endothelial neddylation as a fundamental mechanism maintaining vascular homeostasis and a potential therapeutic target for cardiovascular and inflammatory diseases.

pathology↗

Sex differences in human IgG1-mediated angiogenesis inhibition depend on Y chromosome-encoded DDX3Y

Prevalent diseases of angiogenesis such as age-related macular degeneration (AMD) exhibit sex-specific prevalence, with female sex being an independent risk factor for the advanced neovascular form of AMD. The basis for these sex differences is poorly understood. Here, we quantify the impact of sex on suppression of aberrant choroidal angiogenesis by human immunoglobulin 1 (hIgG1), which possesses class-wide, antigen-independent anti-angiogenic activity. Males exhibited significantly more robust hIgG1-induced chemotaxis inhibition in primary human and mouse macrophages and anti-angiogenic activity in mouse laser-induced choroidal neovascularization (CNV). Four core genotypes and XY* Turner Syndrome mouse models revealed the Y chromosome as a sex-biasing factor contributing to hIgG1 responses. Transcriptomic and RNAi screening identified DEAD-Box Helicase 3 Y-Linked (DDX3Y) as necessary for the robust inhibitory effects of hIgG1 in males. Male mice as well as human and mouse macrophages lacking DDX3Y exhibited blunted hIgG1 responses in CNV and macrophage chemotaxis, resembling those of females. These results unveil a novel mechanism through which sex chromosome complement differences can impact key processes involved in AMD, carrying implications for various sex-related disorders and conditions involving angiogenesis.

pathology↗

Myeloid FtH Regulates Macrophage Response to Kidney Injury by Modulating Snca and Ferroptosis

This study explored the role of myeloid ferritin heavy chain (FtH) in coordinating kidney iron trafficking in health and disease. Synuclein- (Snca) was the sole iron-binding protein upregulated in response to myeloid FtH deletion (FtH{Delta}/{Delta}). Following kidney injury, FtH{Delta}/{Delta} mice showed worsened kidney function. Transcriptome analysis revealed coupling of FtH deficiency with ferroptosis activation, a regulated cell death associated with iron accumulation. Adverse effects of ferroptosis were evidenced by upregulation of ferroptosis-related genes, increased oxidative stress markers, and significant iron deposition in kidney tissues. This iron buildup in FtH{Delta}/{Delta} kidneys stemmed from macrophage reprogramming into an iron-recycling phenotype, driven by Spic induction. Mechanistically, we establish that monomeric Snca functions as a ferrireductase catalyst, intensifying oxidative stress and triggering ferroptosis. Additionally, Snca accumulates in kidney diseases distinguished by leukocyte expansion across species. These findings position myeloid FtH as a pivotal orchestrator of the FtH-Snca-Spic axis driving macrophage reprogramming and kidney injury. HighlightsO_LIMyeloid FtH deficiency drives kidney injury via activation of ferroptosis C_LIO_LIM{Phi} FtH deficiency induces Snca, linking iron dysregulation to M{Phi} function and response to kidney injury C_LIO_LIFerrireductase activity of monomeric Snca augments oxidative stress, promoting lipid peroxidation and ferroptosis C_LI In briefM{Phi} FtH modulates Snca and Spic to coordinate the injury response, linking iron trafficking to ferroptosis-induced kidney injury

pathology↗