👤 Samuel Leighton

Inflammation contributes to Alzheimer's disease (AD), but its stage-specific and amyloid-dependent patterns remain unclear. We analyzed 964 participants from the Bio-Hermes cohort (cognitively normal [CN] = 404, mild cognitive impairment [MCI] = 302, mild AD = 258). Plasma levels of 32 cytokines, neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) were quantified alongside core AD biomarkers. Associations with cognition, amyloid, apolipoprotein E (APOE) ε4, and clinical outcomes were assessed using analysis of covariance, partial correlations, and regression models. Twenty-four cytokines, NfL, and GFAP differed across cognitive groups. Amyloid stratification revealed a core amyloid-independent profile (14 cytokines + NfL) and a broader amyloid-specific profile including GFAP, interleukin (IL)-1β, and IL-18, implicating microglial inflammasome and astrocytic activation. Stage-dependent patterns suggested inflammation may act as early driver, concurrent process, or late amplifier. Paradoxical associations (e.g., eotaxin-2, IL-2R with better memory) and APOE ε4-linked immune differences indicated context-dependent roles. This exploratory study reveals biologically plausible, inflammatory heterogeneity in AD and highlights plasma cytokine profiles as candidate biomarkers and therapeutic targets, warranting investigation. Show less

The conformational state of DNA fine-tunes the transcriptional rate and abundance of RNA. Here, we report that G-quadruplex DNA (G4-DNA) accumulates in neurons, in an experience-dependent manner, and that this is required for the transient silencing and activation of genes that are critically involved in learning and memory in male C57/BL6 mice. In addition, site-specific resolution of G4-DNA by dCas9-mediated deposition of the helicase DHX36 impairs fear extinction memory. Dynamic DNA structure states therefore represent a key molecular mechanism underlying memory consolidation. Show less