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Biology subjects

Waugh, K. A.

Publications and source records attributed to Waugh, K. A..

4 recordsLinked to original sources

Patient cerebral organoids capture Alzheimers disease proteomic biomarkers and drug targets

Patient iPSC-derived cerebral organoids are a leading human model of Alzheimers disease, yet their proteome has never been benchmarked against human disease. Clinical cohorts now nominate thousands of biomarkers and drug targets across three proteomic platforms, and whether patient organoids capture these candidates is unknown. Here, we profile AD and control cerebral organoids containing neurons, astrocytes, and microglia on the three platforms driving clinical discovery, mass spectrometry, SomaScan, and Olink, in both conditioned media and lysate. Benchmarked against 121 studies and clinical cohorts of over 17,000 plasma, CSF, and cortex samples, patient organoids detect almost every nominated candidate and reproduce the disease-associated change in roughly one in four of the most reproducible. This convergence spans plasma, CSF, and cortex, and extends to synaptic, mitochondrial, and proteostatic biology. We provide the first multi-platform reference proteome of a patient-derived AD model, establishing it as a translationally relevant system for studying AD.

neuroscience↗

Altered Hepatic Metabolism in Down Syndrome

Trisomy 21 (T21) gives rise to Down syndrome (DS), the most commonly occurring chromosomal abnormality in humans. T21 affects nearly every organ and tissue system in the body, predisposing individuals with DS to congenital heart defects, autoimmunity, and Alzheimers disease, among other co-occurring conditions. Here, using multi-omic analysis of plasma from more than 400 people, we report broad metabolic changes in the population with DS typified by increased bile acid levels and protein signatures of liver dysfunction. In a mouse model of DS, we demonstrate conservation of perturbed bile acid metabolism accompanied by liver pathology. Bulk RNA-sequencing revealed widespread impacts of the Dp16 model on hepatic metabolism and inflammation, while single-cell transcriptomics highlighted cell types associated with these observations. Modulation of dietary fat profoundly impacted gene expression, bile acids, and liver pathology. Overall, these data represent evidence for altered hepatic metabolism in DS that could be modulated by diet.

genetics↗

Interferon receptor gene dosage determines multiple hallmarks of Down syndrome

Trisomy 21 causes Down syndrome, a condition characterized by cognitive impairments, immune dysregulation, and atypical morphogenesis. Using whole blood transcriptome analysis, we demonstrate that specific overexpression of four interferon receptors encoded on chromosome 21 associates with chronic interferon hyperactivity and systemic inflammation in Down syndrome. To define the contribution of interferon receptor overexpression to Down syndrome phenotypes, we used genome editing to correct interferon receptor gene dosage in mice carrying triplication of a large genomic region orthologous to human chromosome 21. Normalization of interferon receptor copy number attenuated lethal antiviral responses, prevented heart malformations, decreased developmental delays, improved cognition and normalized craniofacial anomalies. Therefore, interferon receptor gene dosage determines major hallmarks of Down syndrome, indicating that trisomy 21 elicits an interferonopathy amenable to therapeutic intervention. One-Sentence SummaryCorrection of interferon receptor gene dosage rescues multiple key phenotypes in a mouse model of trisomy 21.

genetics↗

Trisomy 21 drives production of neurotoxic tryptophan catabolites via the interferon-inducible kynurenine pathway

Trisomy 21 (T21) causes Down syndrome (DS), affecting immune and neurological function by unknown mechanisms. We report here the results of a large metabolomics study showing that people with DS produce elevated levels of kynurenine and quinolinic acid, two tryptophan catabolites with potent immunosuppressive and neurotoxic properties, respectively. We found that immune cells of people with DS overexpress IDO1, the rate-limiting enzyme in the kynurenine pathway (KP) and a known interferon (IFN)-stimulated gene. Furthermore, we found a positive correlation between levels of specific inflammatory cytokines and KP dysregulation. Using metabolic flux assays, we found that IFN stimulation causes IDO1 overexpression and kynurenine overproduction in cells with T21, dependent on overexpression of IFN receptors encoded on chromosome 21. Finally, KP dysregulation is conserved in a mouse model of DS carrying triplication of the IFN receptors. Altogether, these results reveal a mechanism by which T21 could drive immunosuppression and neurotoxicity in DS.

physiology↗