Tau protein as a regulator of mitochondrial function and dynamics

Area of Science:

• Neuroscience
• Cell Biology
• Mitochondrial Biology

Background:

• Mitochondrial damage is a key feature of brain aging and neurodegenerative diseases.
• The role of wild-type (WT) Tau in mitochondrial homeostasis is largely unknown, unlike pathological Tau mutations.

Purpose of the Study:

• To investigate the physiological function of WT Tau in maintaining mitochondrial homeostasis.
• To explore Tau's role in mitochondrial dynamics, function, and stress response.

Main Methods:

• Utilized Caenorhabditis elegans (C. elegans) and mice models lacking Tau homologs (PTL-1 and Tau, respectively).
• Assessed mitochondrial dynamics, function, redox homeostasis, and stress resistance (heat, mitochondrial stress).
• Investigated the role of FZO-1 (mitofusin homolog) through gene knockout and overexpression studies.

Main Results:

• Tau deficiency in both models led to a pro-fusion mitochondrial state with enhanced mitochondrial function.
• Loss of Tau increased mitochondrial activity and altered redox homeostasis.
• Tau-deficient C. elegans exhibited enhanced resistance to heat and mitochondrial stress.
• FZO-1 knockout abolished these beneficial effects, while FZO-1 overexpression mimicked aspects of Tau deficiency.

Conclusions:

• WT Tau plays a conserved role in limiting mitochondrial fusion and adaptation.
• Tau deficiency promotes beneficial mitochondrial adaptations and enhances stress resistance.
• These findings highlight Tau's contribution to mitochondrial homeostasis and cellular stress responses.