Cited by 317Cholesterol and Lipid MetabolismSteroid Chemistry and BiochemistryPlant biochemistry and biosynthesis

Cholesterol 24-Hydroxylase: an enzyme of cholesterol turnover in the brain

Open access
Russell, David W., Halford, Rebekkah W., Ramirez, Denise M.O., Shah, Rahul, Kotti, Tiina·2009·Annual Review of Biochemistry

Abstract

Cholesterol 24-hydroxylase is a highly conserved cytochrome P450 that is responsible for the majority of cholesterol turnover in the vertebrate central nervous system. The enzyme is expressed in neurons, including hippocampal and cortical neurons that are important for learning and memory formation. Disruption of the cholesterol 24-hydroxylase gene in the mouse reduces both cholesterol turnover and synthesis in the brain but does not alter steady-state levels of cholesterol in the tissue. The decline in synthesis reduces the flow of metabolites through the cholesterol biosynthetic pathway, of which one, geranylgeraniol diphosphate, is required for learning in the whole animal and for synaptic plasticity in vitro. This review focuses on how the link between cholesterol metabolism and higher-order brain function was experimentally established.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1146/annurev.biochem.78.072407.103859

Cites

113 of 113 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • When neurons require cholesterol turnover or accumulate too much cholesterol or its intermediates, Cyp46a1 hydroxylates cholesterol to produce 24S-hydroxycholesterol, allowing egress by one-way diffusion into the circulation across the blood brain barrier.

    “When neurons require cholesterol turnover or accumulate too much cholesterol or its intermediates, the cytochrome P450 oxidase Cyp46a1 hydroxylates cholesterol to produce 24S-hydroxycholesterol (24SOHC), allowing for egress by one-way diffusion into the circulation across the BBB (Fig. 4a)31.”

    From A suppressor screen in Mecp2 mutant mice implicates cholesterol metabolism in Rett syndrome (2013) · cites this paper as [31]

    Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured
  • Cholesterol turnover is required to produce geranylgeraniol, a product of HMGCR upstream of SQLE that is essential for learning and synaptic plasticity.

    “Cholesterol turnover is also required to produce geranylgeraniol, a product of HMGCR upstream of SQLE that is essential for learning and synaptic plasticity31, and is important for the interaction between neurons and astrocytes at the synapse28.”

    From A suppressor screen in Mecp2 mutant mice implicates cholesterol metabolism in Rett syndrome (2013) · cites this paper as [31]

    The Summary and Outlook and ‘Rescue by Geranylgeraniol’ sections link reduced brain cholesterol turnover to reduced biosynthetic flow, learning deficits in mice, and impaired hippocampal LTP that geranylgeraniol restores. The copy does not establish the claim’s specific HMGCR-to-SQLE placement, and it says the active form may be geranylgeraniol, geranylgeranyl diphosphate, or another metabolite. The neuron–astrocyte clause has a separate citation and is not assessed here; the indexed passages provide no page numbers. (LLM, conf=0.85)

    Experimental — accuracy not yet measured
  • The catabolic pathway facilitated by cholesterol 24-hydroxylase (CYP46A1) is the major route for eliminating cholesterol from the CNS and is a key player in the maintenance of cholesterol homeostasis in the brain.

    “This catabolic pathway, which is facilitated by cholesterol 24-hydroxylase (CYP46A1), is the major route for eliminating cholesterol from the CNS, and is therefore a key player in the maintenance of cholesterol homeostasis in the brain (Lütjohann et al., 1996; Russell et al., 2009).”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 3

  1. [4]Dietschy JM Turley SD 2004 Cholesterol metabolism in the central nervous system during early development and in the mature animal J Lipid Res 45 1375 97 15254070
  2. [42]Makino I Sjovall J Norman A Strandvik B 1971 Excretion of 3β-hydroxy-5-cholenoicand 3α-hydroxy-5α-cholanoic acids in urine of infants with biliary atresia FEBS Lett 15 161 64 11945837
  3. [89]Leung KF Baron R Seabra MC 2006 Geranylgeranylation of Rab GTPases J Lipid Res 47 467 75 16401880

Cited by

Sorted by citations

Authors
Russell, D. W., Halford, R. W., Ramirez, D. M. O., Shah, R., & Kotti, T.
Affiliations
The University of Texas Southwestern Medical Center (US)
Venue
Annual Review of Biochemistry
Published
2009-06-01
Volume
78
Issue
1
Pages
1017-1040
ISSN
  • 0066-4154 (ISSN-L)
  • 1545-4509
OpenAlex
W2128990583
Cited by
317
References
113
Citations by year
2026: 11 · 2025: 18 · 2024: 27 · 2023: 16 · 2022: 23 · 2021: 40 · 2020: 26 · 2019: 20 · 2018: 16 · 2017: 12 · 2016: 18 · 2015: 14 · 2014: 13 · 2013: 13 · 2012: 16
FWCI
2.66
Type
journal article
Language
en
Open access
Locations
  • Annual Review of Biochemistry (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • Welch Foundation
  • National Institutes of Health
  • National Heart, Lung, and Blood Institute (HL-20948, P01HL020948)
  • National Institute of General Medical Sciences (GM 69338, U54GM069338)
  • National Institute of Diabetes and Digestive and Kidney Diseases (DK 81182, PL1DK081182)
Topics
  • Health Sciences › Medicine › Surgery › Cholesterol and Lipid Metabolism
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Steroid Chemistry and Biochemistry
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Plant biochemistry and biosynthesis
Keywords
cholesterol 24-hydroxylase, cholesterol turnover, brain cholesterol metabolism, cytochrome P450, cholesterol biosynthesis, learning and memory, synaptic plasticity, hippocampal neurons, cortical neurons
MeSH terms
Cholesterol 24-Hydroxylase, Animals, Brain, Cholesterol, Hippocampus, Humans, Learning, Neurons, Steroid Hydroxylases, Gene Expression Regulation, Enzymologic

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review