神経カルシウム振動の組織間通信における役割を解明(Scientists Reveal Neuronal Calcium Oscillations involved in Tissue Communication)

2025-03-26

2025-03-20 中国科学院(CAS)

Model of chronic mitochondrial stress leads to tmbim-2-dependent spatiotemporal Ca²⁺ waves to coordinate neuronal-to-intestinal UPR^mt activation and aging (Image by IGDB)

中国科学院遺伝・発生生物学研究所の田野博士率いる研究チームは、神経細胞の慢性的なミトコンドリアストレスが、TMBIM-2依存性のカルシウム(Ca²⁺)振動を介してセロトニンの放出を促進し、これが腸内のミトコンドリア折りたたみ不全タンパク質応答(UPR^mt)を活性化することを明らかにしました。TMBIM-2は、プラズマ膜カルシウムポンプMCA-3と協調してシナプス部位での持続的なCa²⁺シグナル振動を維持します。さらに、TMBIM-2の発現は加齢とともに減少し、線虫におけるTMBIM-2の過剰発現は認知機能の低下を改善し、寿命を延ばすことが示されました。この研究は、神経細胞のカルシウム振動が組織間シグナル伝達や寿命調節において重要な役割を果たすことを示し、老化介入や代謝健康の新たな治療標的を提供します。

<関連情報>

TMBIM-2はCa2+振動の促進を介して全身のミトコンドリアストレス応答を制御する
TMBIM-2 orchestrates systemic mitochondrial stress response via facilitating Ca²⁺ oscillations

Jiasheng Li,Jimeng Cui,Xinyu Li,Di Zhu,Zhenhua Chen,Xiahe Huang,Yingchun Wang,Qingfeng Wu,Ye Tian
Journal of Cell Biology Published:March 18 2025
DOI:https://doi.org/10.1083/jcb.202408050

Neuronal mitochondrial function is critical for orchestrating inter-tissue communication essential for overall fitness. Despite its significance, the molecular mechanism underlying the impact of prolonged mitochondrial stresses on neuronal activity and how they orchestrate metabolism and aging remains elusive. Here, we identified the evolutionarily conserved transmembrane protein XBX-6/TMBIM-2 as a key mediator in the neuronal-to-intestinal mitochondrial unfolded protein response (UPR^mt). Our investigations reveal that intrinsic neuronal mitochondrial stress triggers spatiotemporal Ca²⁺ oscillations in a TMBIM-2-dependent manner through the Ca²⁺ efflux pump MCA-3. Notably, persistent Ca²⁺ oscillations at synapses of ADF neurons are critical for facilitating serotonin release and the subsequent activation of the neuronal-to-intestinal UPR^mt. TMBIM2 expression diminishes with age; however, its overexpression counteracts the age-related decline in aversive learning behavior and extends the lifespan of Caenorhabditis elegans. These findings underscore the intricate integration of chronic neuronal mitochondrial stress into neurotransmission processes via TMBIM-2-dependent Ca²⁺ equilibrium, driving metabolic adaptation and behavioral changes for the regulation of aging.