Figure 2. The role of mitochondrial Ca ²⁺ signalling in skeletal muscle trophism.

Schematic representation of the effects of manipulating mitochondrial Ca ²⁺ uptake in skeletal muscle fibres. Increased mitochondrial Ca ²⁺ accumulation by enhanced expression of mitochondrial Ca ²⁺ uniporter (MCU) or mitochondrial Ca ²⁺ uptake protein 1.1 (MICU1.1) leads to muscle hypertrophy by stimulating fibre growth and ATP production (left). Reduction of mitochondrial Ca ²⁺ uptake by downregulation of either MCU or MICU1.1 causes fibre atrophy and impaired ATP production (right). [Ca ²⁺] _mt, mitochondrial Ca ²⁺ concentration.