PGC-related gene variants and elite endurance athletic status in a Chinese cohort: A functional study
SCANDINAVIAN JOURNAL OF MEDICINE & SCIENCE IN SPORTS
Authors: He, Z-H.; Hu, Y.; Li, Y-C.; Gong, L-J.; Cieszczyk, P.; Maciejewska-Karlowska, A.; Leonska-Duniec, A.; Muniesa, C. A.; Marin-Peiro, M.; Santiago, C.; Garatachea, N.; Eynon, N.; Lucia, A.
Abstract
This study aims to examine the association between proliferator-activated receptor (PGC)-gene family-related single nucleotide polymorphisms (SNPs) and elite endurance runners' status in a Chinese cohort, and to gain insights into the functionality of a subset of SNPs. Genotype distributions of 133 SNPs in PPARGC1A, PPARGC1B, PPRC1, TFAM, TFB1M, TFB2M, NRF1, GABPA, GABPB1, ERR, and SIRT1 genes were compared between 235 elite Chinese (Han) endurance runners (127 women) and 504 healthy non-athletic controls (237 women). Luciferase gene reporter activity was determined in 20 SNPs. After adjusting for multiple comparisons (in which threshold P-value was set at 0.00041), no significant differences were found in allele/genotype frequencies between athletes and controls (when both sexes were analyzed either together or separately). The lowest P-value was found in PPARGC1A rs4697425 (P=0.001 for the comparison of allele frequencies between elite female endurance runners and their gender-matched controls). However, no association (all P>0.05) was observed for this SNP in a replication cohort from Poland (194 endurance athletes and 190 controls). Using functional genomics tool, the following SNPs were found to have functional significance: PPARGC1A rs6821591, rs12650562, rs12374310, rs4697425, rs13113110, and rs4452416; PPARGC1B rs251466 and rs17110586; and PPRC1 rs17114388 (all P<0.001). This study found no significant association between PGC-related SNPs and elite endurance athlete status in the Chinese population, despite some SNPs showing potential functional significance and the strong biological rationale to hypothesize that this gene pathway is a candidate to influence endurance exercise capacity.
Activation of Mitochondrial Biogenesis by Heme Oxygenase-1-mediated NF-E2-related Factor-2 Induction Rescues Mice from Lethal Staphylococcus aureus Sepsis
AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE
Authors: MacGarvey, Nancy Chou; Suliman, Hagir B.; Bartz, Raquel R.; Fu, Ping; Withers, Crystal M.; Welty-Wolf, Karen E.; Piantadosi, Claude A.
Abstract
Rationale: Mitochondrial damage is an important component of multiple organ failure syndrome, a highly lethal complication of severe sepsis that lacks specific therapy. Mitochondrial quality control is regulated in part by the heme oxygenase-1 (HO-1; Hmox1) system through the redox-regulated NF-E2-related factor-2 (Nrf2) transcription factor, but its role in mitochondrial biogenesis in Staphylococcus aureus sepsis is unknown. Objectives: To test the hypothesis that Nrf2-dependent up-regulation of the HO-1/carbon monoxide (CO) system would preserve mitochondrial biogenesis and rescue mice from lethal S. aureus sepsis. Methods: A controlled murine S. aureus peritonitis model with and without inhaled CO was examined for HO-1 and Nrf2 regulation of mitochondrial biogenesis and the resolution of hepatic mitochondrial damage. Measurements and Main Results: Sepsis survival was significantly enhanced using inhaled CO (250 ppm once-daily for 1 h), and linked mechanistically to Hmox1 induction and mitochondria! HO activity through Nrf2 transcriptional and Akt kinase activity. HO-1/CO stimulated Nrf2-dependent gene expression and nuclear accumulation of nuclear respiratory factor-1, -2 alpha (Gabpa), and peroxisome proliferator-activated receptor gamma coactivator-1 alpha; increased mitochondrial transcription factor-A and citrate synthase protein levels; and augmented mtDNA copy number. CO enhanced antiinflammatory IL-10 and reduced proinflammatory tumor necrosis factor-a production. By contrast, Nrf2(-/-) and Akt1(-/-) mice lacked CO induction of Hmox1 and mitochondrial biogenesis, and CO rescued neither strain from S. aureus sepsis. Conclusions: We identify an inducible Nrf2/HO-1 regulatory cycle for mitochondrial biogenesis that is prosurvival and counter-inflammatory in sepsis, and describe targeted induction of mitochondrial biogenesis as a potential multiple organ failure therapy.