Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Peroxisomes01:24

Peroxisomes

Peroxisomes are specialized organelles present in fungi, plant, and animal cells. It can vary in number, size, morphology, and activity depending on the type of tissue and the nutritional state of the cell. For example, cells with active lipid metabolism, such as adipocytes, neurons, and hepatocytes, have more peroxisomes than other cells in the body. Besides their primary role in breaking down complex organic molecules, peroxisomes can also synthesize specific macromolecules and participate in...
Peroxisomes01:24

Peroxisomes

Peroxisomes are specialized organelles present in fungi, plant, and animal cells. It can vary in number, size, morphology, and activity depending on the type of tissue and the nutritional state of the cell. For example, cells with active lipid metabolism, such as adipocytes, neurons, and hepatocytes, have more peroxisomes than other cells in the body. Besides their primary role in breaking down complex organic molecules, peroxisomes can also synthesize specific macromolecules and participate in...
Peroxisomes and Mitochondria01:30

Peroxisomes and Mitochondria

Peroxisomes and mitochondria are two important oxygen-utilizing organelles in eukaryotic cells. Mitochondria carry out cellular respiration—the process that converts energy from food into ATP. Peroxisomes carry out a variety of functions, primarily breaking down different substances, such as fatty acids.
The peroxisome is a single membrane-bound cellular organelle that can perform several different functions, including lipid metabolism and chemical detoxification. The enzymes within peroxisomes...
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide02:44

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
Oxidation of Phenols to Quinones01:17

Oxidation of Phenols to Quinones

In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids02:04

Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids

Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

AAV8-based gene replacement therapy for hereditary spastic paraplegia type 5.

Molecular therapy. Methods & clinical development·2025
Same author

Novel findings in a Swedish primary familial brain calcification cohort.

Journal of the neurological sciences·2024
Same author

CYP46A1-mediated cholesterol turnover induces sex-specific changes in cognition and counteracts memory loss in ovariectomized mice.

Science advances·2024
Same author

Different effects of CYP27A1 and CYP7B1 on cognitive function: Two mouse models in comparison.

The Journal of steroid biochemistry and molecular biology·2023
Same author

27-hydroxycholesterol promotes oligodendrocyte maturation: Implications for hypercholesterolemia-associated brain white matter changes.

Glia·2023
Same author

Ventriculoperitoneal Shunt Treatment Increases 7 Alpha Hy-Droxy-3-Oxo-4-Cholestenoic Acid and 24-Hydroxycholesterol Concentrations in Idiopathic Normal Pressure Hydrocephalus.

Brain sciences·2022

Related Experiment Video

Updated: May 17, 2026

Improved Lipofuscin Models and Quantification of Outer Segment Phagocytosis Capacity in Highly Polarized Human Retinal Pigment Epithelial Cultures
10:39

Improved Lipofuscin Models and Quantification of Outer Segment Phagocytosis Capacity in Highly Polarized Human Retinal Pigment Epithelial Cultures

Published on: April 14, 2023

Five decades with oxysterols.

Ingemar Björkhem1

  • 1Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, Sweden. ingemar.bjorkhem@karolinska.se

Biochimie
|November 1, 2012
PubMed
Summary

Oxysterols, like 7α-hydroxy-4-cholesten-3-one, are not master regulators of cholesterol homeostasis. Research shows they play roles in bile acid synthesis and elimination but have minimal impact in vivo.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Cholesterol Metabolism

Background:

  • Oxysterols are cholesterol oxidation products with diverse biological roles.
  • Previous research suggested oxysterols might be key regulators of cholesterol homeostasis.
  • Specific oxysterols, such as 7α-hydroxy-4-cholesten-3-one, 27-hydroxycholesterol, and 24S-hydroxycholesterol, have been investigated for their involvement in various physiological processes.

Purpose of the Study:

  • To review key research on oxysterols, focusing on their synthesis, metabolism, and physiological significance.
  • To investigate the role of 7α-hydroxy-4-cholesten-3-one in bile acid synthesis and its pathogenetic contribution to Cerebrotendinous xanthomatosis.
  • To evaluate the in vivo impact of side-chain oxidized oxysterols (27-hydroxycholesterol and 24S-hydroxycholesterol) on cholesterol homeostasis.

More Related Videos

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein
07:29

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein

Published on: October 12, 2017

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
06:18

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause

Published on: August 13, 2019

Related Experiment Videos

Last Updated: May 17, 2026

Improved Lipofuscin Models and Quantification of Outer Segment Phagocytosis Capacity in Highly Polarized Human Retinal Pigment Epithelial Cultures
10:39

Improved Lipofuscin Models and Quantification of Outer Segment Phagocytosis Capacity in Highly Polarized Human Retinal Pigment Epithelial Cultures

Published on: April 14, 2023

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein
07:29

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein

Published on: October 12, 2017

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
06:18

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause

Published on: August 13, 2019

Main Methods:

  • Synthesis of radiolabeled steroids for metabolic studies.
  • Investigation of enzyme mechanisms involved in oxysterol conversion.
  • Utilizing mouse models with manipulated levels of specific oxysterols (e.g., high/low 27-hydroxycholesterol, increased 24S-hydroxycholesterol).

Main Results:

  • Demonstrated 7α-hydroxy-4-cholesten-3-one as a bile acid precursor and a key factor in Cerebrotendinous xanthomatosis pathogenesis.
  • Showed that side-chain oxidized oxysterols facilitate cholesterol elimination from macrophages and the brain.
  • Mouse models revealed minimal disturbances in cholesterol homeostasis despite altered oxysterol levels, challenging their proposed role as master regulators.

Conclusions:

  • Oxysterols are involved in cholesterol metabolism and elimination pathways.
  • 7α-hydroxy-4-cholesten-3-one plays a significant role in specific disease states.
  • Contrary to in vitro findings, oxysterols do not appear to be master regulators of cholesterol homeostasis in vivo.