O-32 - Dietary choline or TMAO supplementation increases atherosclerosis in Apoe--- mice, correlating with plasma TMAO and not with plasma lipids
Own mouse experiment. The lipid-independence (no rise in cholesterol/TG/glucose) is central: it marks TMAO as a non-lipid atherogenic pathway.
Link to originalMethodology
Mixed design. HUMAN (rests on the Cleveland Clinic GeneBank/BioBank angiography cohort, D-4): untargeted plasma metabolomics in a prospective learning cohort (50 cases vs 50 matched controls, 3-year MI/stroke/death) and validation cohort (25 vs 25) identified choline, TMAO, and betaine; an independent 1,876-subject cohort tested dose-dependent association with prevalent CVD and angiographic burden. All human subjects were stable patients referred for elective coronary evaluation. MOUSE / mechanistic (own experiments, S-28): Apoe-/- mice fed control vs choline (0.5-1.0%) or TMAO (0.12%) chow for ~16 weeks; stable-isotope (d9-choline/d9-PC) tracer challenges in normal, antibiotic-treated, germ-free, and conventionalized mice; broad-spectrum-antibiotic suppression experiments; macrophage scavenger-receptor and foam-cell assays; and an F2 intercross mapping the FMO3 locus. COI: senior author Hazen holds patent/commercial interests in TMAO diagnostics (flagged across the Hazen-lab TMAO corpus).
Link to original
Why this is evidence
Choline/TMAO raise atherosclerosis in mice with no rise in cholesterol/TG/lipids — a non-lipid atherogenic route, the kind of non-cholesterol ‘other exposure’ H-54 posits. H-26 requires cholesterol/lipid mediation and H-3 fat quality; this supports H-54’s mechanistic plausibility over both.
Likelihood
# E-107 (HC-5) — lone edge, one observation O-32 "lipid-independent atherogenic pathway in mice". Members in
# HC-5.hypotheses order [H-3 fat-quality, H-26 dietary-cholesterol, H-54 residual]. Choline/TMAO supplementation
# raised aortic plaque in Apoe-/- mice with plasma TMAO (not lipids) tracking plaque — a non-lipid atherogenic
# route, established causally by A-11 (approved: germ-free/antibiotic necessity + TMAO sufficiency + host-genetic
# segregation). This is the non-cholesterol mechanism H-54 posits; H-26 needs cholesterol/lipid mediation and
# H-3 fat quality. Anchored on H-54 = 1.0.
lik_mouse_H54 = 1.0 # anchor: a lipid-independent choline->TMAO->atherosclerosis chain is exactly H-54's
# non-cholesterol branch made mechanistically concrete.
lik_mouse_H26 = 0.5 # 0.5x: a non-lipid atherogenic route competes with H-26's cholesterol-mediation story, so
# mildly disfavours it — but this is a mouse model, so it does not refute egg-derived
# cholesterol being operative for the human egg-CVD association.
lik_mouse_H3 = 0.5 # 0.5x: same magnitude — a mouse TMAO-atherosclerosis result is orthogonal-to-mildly-awkward
# for H-3's claim about fat vs cholesterol as the plasma-cholesterol lever.
t_mouse = 0.72 # cap = trust of O-32's source S-28 (Wang 2011 Nature) = 0.72. Held at cap: the mouse
# experiment is well-controlled and A-11 establishes the causal chain within mice; the
# mouse->human relevance limit is carried in the modest 1.0-vs-0.5 ratio, not a t dock.
evidence("HC-5", ["O-32"], [lik_mouse_H3, lik_mouse_H26, lik_mouse_H54], t=t_mouse)