Elevated cholesterol in APOE4 astrocytes drives mitochondrial cristae collapse and ATP synthase dysfunction

Verdict. Here we show that elevated intracellular cholesterol in murine astrocytes expressing the Alzheimer’s disease risk variant APOE4 disrupts the inner mitochondrial membrane, manifesting as sparse, truncated cristae alongside an excess of cristae junction complexes. It intersects mitochondrial stress/dysfunction themes (mitochondrial dysfunction; cell death; OXPHOS / ETC).

What the authors report

ABSTRACT Cholesterol imbalance is a hallmark of major human diseases, including atherosclerosis and Alzheimer’s disease, both of which are also associated with mitochondrial dysfunction, yet the mechanistic links between cholesterol and mitochondria remain poorly understood. Strikingly, APOE4 astrocytes are hypersensitive to the ATP synthase inhibitor oligomycin, demonstrating a profound dysfunction of the enzyme, and cholesterol sequestration with methyl-β-cyclodextrin abrogates this toxicity, establishing elevated cholesterol as its proximate cause.

Key results stated in the abstract include the following. Here we show that elevated intracellular cholesterol in murine astrocytes expressing the Alzheimer’s disease risk variant APOE4 disrupts the inner mitochondrial membrane, manifesting as sparse, truncated cristae alongside an excess of cristae junction complexes. These structural abnormalities are accompanied by loss of respiratory chain complexes I and IV, and reduced respiration; nevertheless, low proton leak and reverse ATP synthase activity combine to generate an elevated mitochondrial membrane potential. Reciprocally, reducing intracellular cholesterol via nutrient restriction restored cristae architecture and partially rescued respiratory chain complex abundance.

Why it matters for mitochondrial biology

Within mitochondrial research, this work maps primarily to OXPHOS, redox biology, neurobiology, structural biology. It is relevant to mitochondrial dysfunction discourse because the abstract invokes mitochondrial dysfunction, cell death, OXPHOS / ETC, disease context. That does not by itself establish a validated disease mechanism; it indicates thematic proximity. OXPHOS/ETC involvement, if confirmed, would place the work in the core of bioenergetic pathophysiology rather than peripheral organelle biology. Server: biorxiv. Posted 2026-08-04. Synthesis confidence is bounded by abstract completeness.

Study design (abstract-level)

Here we show that elevated intracellular cholesterol in murine astrocytes expressing the Alzheimer’s disease risk variant APOE4 disrupts the inner mitochondrial membrane, manifesting as sparse, truncated cristae alongside an excess of cristae junction complexes.

Principal findings

1. Here we show that elevated intracellular cholesterol in murine astrocytes expressing the Alzheimer’s disease risk variant APOE4 disrupts the inner mitochondrial membrane, manifesting as sparse, truncated cristae alongside an excess of cristae junction complexes.
2. These structural abnormalities are accompanied by loss of respiratory chain complexes I and IV, and reduced respiration; nevertheless, low proton leak and reverse ATP synthase activity combine to generate an elevated mitochondrial membrane potential.
3. Reciprocally, reducing intracellular cholesterol via nutrient restriction restored cristae architecture and partially rescued respiratory chain complex abundance.
4. These findings identify mitochondrial cholesterol as a critical determinant of cristae architecture and ATP synthase function and suggest that cholesterol-driven mitochondrial dysfunction may be a unifying feature of cholesterol-related disorders from neurodegeneration to atherosclerosis.
5. These findings position cholesterol as a key determinant of the cristae landscape and ATP synthase function, highlighting the importance of the emerging field of mitochondrial-cholesterol crosstalk.

Limitations of this brief

• This Mitos brief is an abstract-level synthesis of a preprint; it is not peer review and not a substitute for reading the full paper.
• Preprint status: findings may change with revision or journal review.
• Effect sizes, n numbers, statistics, and full experimental controls are typically incomplete at abstract resolution.
• Comparator/control language is weak or absent in the abstract, limiting causal inference from this brief alone.
• Primary source: biorxiv DOI 10.64898/2026.08.04.742391 (posted 2026-08-04).

Open scientific questions

• Which specific experimental panels in the full paper establish the strongest causal claim, and how robust are the controls?
• Are OXPHOS defects primary drivers or secondary consequences of broader cellular stress?
• Is the mitochondrial phenotype cell-autonomous in neurons/glia, or secondary to systemic/inflammatory signals?
• How do these findings sit relative to prior literature on the same pathway—replication, contradiction, or incremental extension?

Bottom line

For mitochondrial biologists focused on OXPHOS, redox biology, neurobiology, this preprint is worth full-text review soon. Abstract-level takeaway: Here we show that elevated intracellular cholesterol in murine astrocytes expressing the Alzheimer’s disease risk variant APOE4 disrupts the inner mitochondrial membrane, manifesting as sparse, truncated cristae alongside an excess of cristae junction complexes. Confirm methods, effect sizes, and controls in the full PDF before citing the result as established.

Bibliographic record

Abstract-based editorial synthesis by Mitos. Not peer review.