👤 Maria Letizia Taddei

Apolipoprotein E (APOE) genotype influences the presence, course and severity of sporadic cerebral amyloid angiopathy (sCAA). We investigated the effect of the APOE ε4-allele on clinical and neuroradiological outcomes in mutation-carriers with Dutch-type hereditary (D-)CAA. Participants with D-CAA from a prospective cohort study, with data collected on history of symptomatic intracerebral hemorrhages (sICH) and vascular risk factors, underwent 3 Tesla magnetic resonance imaging (MRI) scans to assess macrobleeds, cerebral microbleeds (CMBs), cortical superficial siderosis (cSS), enlarged perivascular spaces (EPVS), white matter hyperintensity (WMH) volume and WMH multispot lesions. Global cognition was measured using Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) scores. Associations between ≥1 APOE ε4-allele and age of first sICH, time to recurrence, cognition and radiological data were analyzed with adjustments for confounders. Eighty-one participants (mean age 47 years, 54% women, 38% with sICH history) were included. The APOE ε4-allele was not associated with earlier sICH onset (median age 56 versus 57 years; p = 0.6) or time to recurrence (5.0 versus 3.9 years; p = 0.4), nor was it associated with macrobleeds (β 2.0; 95%CI 2.4- -2.7; p = 0.4), CMBs (β 2.9; 95%CI 1.0-8.9; p = 0.06), cSS (aOR 0.5; 95%CI 0.1-2.0; p = 0.3), EPVS (aOR 0.4; 95%CI 0.1-1.5; p = 0.6), WMH volume (β 6.8; 95%CI -1.9-15.4; p = ), a multispot pattern (OR 0.7; 95%CI 0.2-2.7, p = 0.6), or cognition (β -0.3; 95%CI -0.4- -0.5; p = 0.5). APOE ε4 does not affect key clinical parameters or D-CAA neuroradiological markers and therefore does not explain the large variation in disease course in D-CAA. Show less

Short-chain fatty acids (SCFAs) produced by gut microbial fermentation influence host metabolism and neuroinflammatory processes implicated in Alzheimer's disease (AD). However, the relationship between fecal SCFAs, microbial taxa, and cerebral amyloid-β (Aβ) burden in cognitively unimpaired individuals remains unclear. Fecal SCFAs were quantified using GC-MS, and microbial species were profiled by shotgun metagenomics in 87 participants. Associations between SCFAs, demographics, APOE ε4 status, and Aβ burden were tested using nonparametric statistics and multivariable regression. Microbial-SCFA links were evaluated using Spearman correlations and multivariate ordinations, with mediation analysis exploring potential indirect pathways. Acetate was the predominant SCFA and demonstrated the most robust microbial associations. Higher acetate concentrations were positively associated with Show less

The epithelial-to-mesenchymal transition (EMT) is a complex transcriptional program induced by transforming growth factor β1 (TGF-β1). Histone lysine-specific demethylase 1 (LSD1) has been recognized as a key mediator of EMT in cancer cells, but the precise mechanism that underlies the activation and repression of EMT genes still remains elusive. Here, we characterized the early events induced by TGF-β1 during EMT initiation and establishment. TGF-β1 triggered, 30-90 min post-treatment, a nuclear oxidative wave throughout the genome, documented by confocal microscopy and mass spectrometry, mediated by LSD1. LSD1 was recruited with phosphorylated SMAD2/3 to the promoters of prototypic genes activated and repressed by TGF-β1. After 90 min, phospho-SMAD2/3 downregulation reduced the complex and LSD1 was then recruited with the newly synthesized SNAI1 and repressors, NCoR1 and HDAC3, to the promoters of TGF-β1-repressed genes such as the Wnt soluble inhibitor factor 1 gene (WIF1), a change that induced a late oxidative burst. However, TGF-β1 early (90 min) repression of transcription also required synchronous signaling by reactive oxygen species and the stress-activated kinase c-Jun N-terminal kinase. These data elucidate the early events elicited by TGF-β1 and the priming role of DNA oxidation that marks TGF-β1-induced and -repressed genes involved in the EMT. Show less