Aberrant upregulation of astroglial ceramide potentiates oligodendrocyte injury

Sunja Kim, Andrew J. Steelman, Yumin Zhang, Hannah C. Kinney, Jianrong Li

Research output: Contribution to journalArticle

Abstract

Oligodendroglial injury is a pathological hallmark of many human white matter diseases, including multiple sclerosis (MS) and periventricular leukomalacia (PVL). Critical regulatory mechanisms of oligodendroglia destruction, however, remain incompletely understood. Ceramide, a bioactive sphingolipid pivotal to sphingolipid metabolism pathways, regulates cell death in response to diverse stimuli and has been implicated in neurodegenerative disorders. We report here that ceramide accumulates in reactive astrocytes in active lesions of MS and PVL, as well as in animal models of demyelination. Serine palmitoyltransferase, the rate-limiting enzyme for ceramide de novo biosynthesis, was consistently upregulated in reactive astrocytes in the cuprizone mouse model of demyelination. Mass spectrometry confirmed the upregulation of specific ceramides during demyelination, and revealed a concomitant increase of sphingosine and a suppression of sphingosine-1- phosphate, a potent signaling molecule with key roles in cell survival and mitogenesis. Importantly, this altered sphingolipid metabolism during demyelination was restored upon active remyelination. In culture, ceramide acted synergistically with tumor necrosis factor, leading to apoptotic death of oligodendroglia in an astrocyte-dependent manner. Taken together, our findings implicate that disturbed sphingolipid pathways in reactive astrocytes may indirectly contribute to oligodendroglial injury in cerebral white matter disorders.

Original languageEnglish (US)
Pages (from-to)41-57
Number of pages17
JournalBrain Pathology
Volume22
Issue number1
DOIs
StatePublished - Jan 1 2012

Keywords

  • cerebral palsy
  • demyelination
  • multiple sclerosis
  • neuroinflammation
  • oligodendrocytes
  • sphingolipid
  • white matter injury

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Neuroscience(all)
  • Clinical Neurology

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