👤 Nathan W Churchill

Psychosis in Alzheimer's disease (AD), including hallucinations and delusions, affects up to 50% of patients and is linked to faster cognitive decline. Delusions can occur across AD, with persecutory delusions early and misidentification delusions late, while hallucinations emerge in advanced stages and predict greater cognitive and functional decline. The APOE4 allele is the strongest genetic risk factor for late-onset AD, although its influence on neuropsychiatric symptoms, including psychosis, remains unclear. This study examined the interaction between APOE4 status, sex, EHT use, and psychosis symptoms in AD using data from participants in the National Alzheimer's Coordinating Center Uniform Data Set. Generalized Additive Models assessed nonlinear associations between predictors and psychosis outcomes, including the presence of delusions, hallucinations, and their visual and auditory subtypes. Analyses were stratified by sex (males: n = 13,841, females: n = 15,354). Predictor variables included APOE4 status, current use of estrogen hormone therapy (EHT) in females. Due to limited data availability, CSF biomarkers (Aβ1-42, p-tau181, t-tau) could not be included in the main models and were instead examined in a secondary sub analysis. APOE4 homozygosity was associated with significantly greater odds of delusions in the past month in both males and females, with a stronger effect in females (p<0.05). In females only, APOE4 homozygosity was significantly associated with hallucinations, with no effect in males (p<0.05). EHT was associated with lower risk of hallucinations in females (p<0.05). These findings underscore sex-specific genetic and biological contributors to psychosis in AD and support sex-stratified approaches to understanding and addressing psychosis symptoms in clinical settings. Show less

Salivary gland cancers (SGCs) are rare and comprise multiple histologic entities. In the recurrent or metastatic (R/M) setting, there is limited evidence for effective systemic anticancer treatment for most subtypes, affecting prognosis and quality of life. Molecular analysis of SGCs holds promise to more accurately classify SGC subtypes and to determine novel therapeutic targets. Fifteen patients with R/M SGC underwent tumor biopsy and blood sampling to perform whole-genome sequencing (WGS) of tumor and germline as part of their standard-of-care management. Small somatic mutations, structural alterations, copy number variation, and mutational signatures were processed using WGS pipelines alongside germline testing. Alterations were correlated to clinical features and fed back to clinical team to inform treatment decisions. WGS quality control was acceptable in 14 of 15 patients (adenoid cystic carcinoma [AdCC, n = 10], salivary duct carcinoma ex pleomorphic adenoma [n = 1]; clear cell myoepithelial carcinoma [n = 1]; epithelial-myoepithelial carcinoma [n = 1]; and acinic cell carcinoma [n = 1]). Genomic rearrangements/fusions were present in 12 of 14. Rearrangements involving MYB and or NFIB were identified in 8 of 10 patients with AdCC. One patient harbored a clinically actionable WGS in SGC is achievable in clinically relevant timeframes, providing genomic information for deeper understanding of disease pathophysiology, to clarify histologic subtype and can identify actionable genomic targets which may not be found through routine sequencing technologies. Further use of WGS has the potential to improve care for patients with SGC. Show less

Red blood cell (RBC) metabolism regulates hemolysis during aging in vivo and in the blood bank. Here, we leveraged a diversity outbred mouse population to map the genetic drivers of fresh/stored RBC metabolism and extravascular hemolysis upon storage and transfusion in 350 mice. We identify the ferrireductase Steap3 as a critical regulator of a ferroptosis-like process of lipid peroxidation. Steap3 polymorphisms were associated with RBC iron content, in vitro hemolysis, and in vivo extravascular hemolysis both in mice and 13,091 blood donors from the Recipient Epidemiology and Donor evaluation Study. Using metabolite Quantitative Trait Loci analyses, we identified a network of gene products (FADS1/2, EPHX2 and LPCAT3) - enriched in donors of African descent - associated with oxylipin metabolism in stored human RBCs and related to Steap3 or its transcriptional regulator, the tumor protein TP53. Genetic variants were associated with lower in vivo hemolysis in thousands of single-unit transfusion recipients. Steap3 regulates lipid peroxidation and extravascular hemolysis in 350 diversity outbred miceSteap3 SNPs are linked to RBC iron, hemolysis, vesiculation in 13,091 blood donorsmQTL analyses of oxylipins identified ferroptosis-related gene products FADS1/2, EPHX2, LPCAT3Ferroptosis markers are linked to hemoglobin increments in transfusion recipients. Show less

Insertional mutants of the fungal maize pathogen Cochliobolus heterostrophus were screened for altered virulence. One mutant had 60% reduction in lesion size relative to WT but no other detectable change in phenotype. Analysis of sequence at the insertion site revealed a gene (CPS1) encoding a protein with two AMP-binding domains. CPS1 orthologs were detected in all Cochliobolus spp. examined, in several other classes of ascomycete fungi, and in animals but not in basidiomycete fungi, bacteria, or plants. Phylogenetic analysis suggested that CPS1 represents a previously undescribed subset of adenylate-forming enzymes that have diverged from certain acyl-CoA ligases, which in bacteria are involved in biosynthesis of nonribosomal peptides or polyketidepeptide hybrids. Disruption of CPS1 caused reduced virulence of both race T and race O of C. heterostrophus on maize, of Cochliobolus victoriae on oats, and of Gibberella zeae on wheat. These results suggest that CPS1 functions as a general fungal virulence factor in plant pathogenic ascomycetes. Show less