Mitochondrial dysfunction compromises ciliary homeostasis in astrocytes

J Cell Biol. 2023 Jan 2;222(1):e202203019. doi: 10.1083/jcb.202203019. Epub 2022 Nov 16.

Abstract

Astrocytes, often considered as secondary responders to neurodegeneration, are emerging as primary drivers of brain disease. Here we show that mitochondrial DNA depletion in astrocytes affects their primary cilium, the signaling organelle of a cell. The progressive oxidative phosphorylation deficiency in astrocytes induces FOXJ1 and RFX transcription factors, known as master regulators of motile ciliogenesis. Consequently, a robust gene expression program involving motile cilia components and multiciliated cell differentiation factors are induced. While the affected astrocytes still retain a single cilium, these organelles elongate and become remarkably distorted. The data suggest that chronic activation of the mitochondrial integrated stress response (ISRmt) in astrocytes drives anabolic metabolism and promotes ciliary elongation. Collectively, our evidence indicates that an active signaling axis involving mitochondria and primary cilia exists and that ciliary signaling is part of ISRmt in astrocytes. We propose that metabolic ciliopathy is a novel pathomechanism for mitochondria-related neurodegenerative diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes* / metabolism
  • Cilia* / metabolism
  • Cilia* / pathology
  • DNA, Mitochondrial
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / metabolism
  • Homeostasis
  • Mice
  • Mitochondria* / metabolism
  • Mitochondria* / pathology
  • Regulatory Factor X Transcription Factors / genetics
  • Regulatory Factor X Transcription Factors / metabolism

Substances

  • Forkhead Transcription Factors
  • FOXJ1 protein, mouse
  • Regulatory Factor X Transcription Factors
  • DNA, Mitochondrial