AI Insight
Researchers discovered that peroxisomes, cellular organelles involved in detoxification and lipid processing, are highly concentrated in brain glial cells and neurons in fruit flies. Importantly, the import of proteins into peroxisomes in cortex glia follows a circadian rhythm that peaks in early morning and is controlled by the biological clock. Disrupting this rhythmic peroxisomal function in glia, but not neurons, causes sleep problems and dramatically alters brain lipid metabolism, revealing distinct roles for these organelles in different brain cell types.
Why it matters
This research establishes a previously unknown connection between circadian rhythms, peroxisomal function in brain support cells, and sleep regulation. The findings could inform understanding of sleep disorders and metabolic conditions linked to circadian disruption, and highlight glial cells as potential therapeutic targets for sleep-related disorders.
Understand the Science
by Anurag Das, Irma Magaly Rivas-Serna, Ankur Kumar, Lakpa Sherpa, Kerui Huang, Hia Kalita, Marlene Dorneich-Hayes, Ruiqi Liu, Vera C. Mazurak, John P. Vaughen, Hua Bai
Peroxisomes are critical organelles that detoxify cellular waste while also catabolizing and anabolizing lipids. How peroxisomes coordinate protein import and support metabolic functions across complex tissues and timescales remains poorly understood in vivo. Using the Drosophila brain, we discover a striking enrichment of peroxisomes in the neuronal soma and the cortex glia that enwrap them. Unexpectedly, import of peroxisomal proteins into cortex glia, but not neurons, oscillated across time and peaked in the early morning. Rhythmic peroxisomal import in cortex glia autonomously required the circadian clock and Peroxin 5 (Pex5; peroxisomal biogenesis factor 5 homolog), with import persistently elevated in clock mutants. Notably, reducing Pex5 in cortex glia, but not neurons, caused hyperactivity and reduced total sleep. Moreover, brain lipid metabolism was dramatically altered upon Pex5 knockdown, with glia impacting sphingolipids and triacylglycerols, and neurons impacting phospholipids. The cell-type specificity of these Pex5 phenotypes highlights unique roles for peroxisomal import in both sleep and lipid metabolism in the brain.
Source: Peroxisomal import is circadian in glia and regulates sleep and lipid metabolism