Cerebrosides and psychosine disrupt mitochondrial functions

Area of Science:

• Biochemistry
• Cellular Biology
• Neuroscience

Background:

• Lysosomal storage diseases, such as Gaucher and Krabbe diseases, involve the accumulation of glycosphingolipids.
• The precise mechanisms by which these accumulated lipids cause cellular dysfunction remain incompletely understood.

Purpose of the Study:

• To investigate the direct effects of specific glycosphingolipids on mitochondrial function.
• To explore the potential impact of glycosphingolipids on cellular bioenergetics and membrane integrity.

Main Methods:

• Isolated liver and brain mitochondria were used to assess the effects of glucocerebroside, galactocerebroside, and psychosine.
• Mitochondrial respiration rates, oxidative phosphorylation, and calcium transport were measured.
• The influence of atractyloside and ATP on these processes was evaluated.

Main Results:

• Glucocerebroside and galactocerebroside significantly increased mitochondrial respiration (33-400%) and decreased oxidative phosphorylation by approximately 30%.
• Psychosine markedly stimulated mitochondrial respiration (66-700%) and completely inhibited oxidative phosphorylation at high concentrations.
• Psychosine blocked Ca2+ transport, an effect not reversed by ATP, and atractyloside did not prevent the respiratory stimulation.

Conclusions:

• Accumulating glycosphingolipids can profoundly impair mitochondrial function, affecting respiration and oxidative phosphorylation.
• These lipids may alter mitochondrial membrane conformation, leading to disruptions in cellular bioenergetics.
• The observed mitochondrial dysfunction provides a potential explanation for the cellular toxicity in Gaucher and Krabbe diseases.