Table 1.

UPR^mt in the context of skeletal muscle and liver.

Reference	Model	Main Findings
Cordeiro et al., 2020 [21]	Young and old mice underwent 4 weeks of aerobic exercise training	Increased UPRmt markers in gastrocnemius muscle of aged mice
Tamura et al., 2017 [22]	Young and aged mice received heat stress treatment	Remarkable improvements in age-related changes in soleus, but minor effects in gastrocnemius and plantaris
Memme et al., 2016 [23]	Rats subjected to chronic contractile activity (CCA) for 1 to 7 days	UPRmt-specific markers were induced 10 to 80% between days 1 and 7
Al-Furoukh et al., 2015 [24]	ClpX overexpression in C2C12 mouse myoblasts and HEK293T cells	Upregulation of markers of the UPRmt
Gariani et al., 2016 [25]	Mice fed with HFHS diet plus nicotinamide riboside	Induction of a SIRT1- and SIRT3-dependent UPRmt, preventing/reverting NAFLD
Quirós et al., 2017 [26]	Multiomics approach in mammalian cells treated with 4 mitochondrial stressors	Identification of ATF4 as the main regulator of the stress response
Fiorese et al., 2016 [27]	C. elegans lacking ATFS-1 and expressing a reporter of UPRmt	Rescue of UPRmt activation under stress conditions by ATF5
Bennett et al., 2014 [28]	Genome-wide RNAi screen for negative regulators of the UPRmt	UPRmt is neither necessary nor sufficient for lifespan extension
Michel et al., 2015 [29]	Impairment of mtDNA expression	Triggering of ISR, but not of UPRmt
Zhao et al., 2002 [30]	Mutated OTC to provoke mitochondrial protein accumulation	Induction of nuclear genes encoding for Hsp60, Hsp10 and ClpP