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RNAseq analysis of exercise, heat, and dehydration stress in a Kona Ironman World Championship
Author(s) -
Lee Elaine ChoungHee,
Aizik Shlomit,
Haddad Faddia,
Zaldivar Frank P,
Casa Douglas J,
Armstrong Lawrence E,
Stearns Rebecca L,
Munoz Colleen X,
Bartley Jenna M,
Maresh Carl M
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.771.10
Subject(s) - transcriptome , downregulation and upregulation , dehydration , biology , physiology , medicine , gene expression , gene , genetics , biochemistry
Exercise and environmental stressors shift genome‐wide, transcript‐level expression in a tissue‐specific manner to upregulate stress‐specific protective genes and downregulate genes required for normal growth and function. The dynamic transcriptional landscape can inform us of the effect that whole body stress (e.g., exercise, environmental heat/humidity exposure, dehydration) has on sub‐cellular health. Studying global genome expression shifts may allow us to elucidate mechanisms of stress resilience, discover new stress biomarkers, identify targets for optimizing performance using supplementation or training paradigms, and better define rest and recovery post‐exercise stress during training. In this study we designed experiments to characterize the transcriptome level changes that occur before and after exercise and environmental stress in conditions that put individuals at high‐risk for exertional heat illness. At the Kona Ironman World Championship (2012) we recruited 8 competitors for participation in this study. Pre‐race (PRE) and immediately post‐race (IP), we collected physiological data (e.g., core body temperature IP (38.51±0.66°C, p<0.05 vs. PRE) and percent body mass change (−3.5±2.0%, p<0.05). Samples for blood analyses were collected two to three days prior to race day (BASE), at IP, and 1 day post‐race (24HPOST) on all subjects. For RNAseq experiments, we analyzed PBMC samples isolated from whole blood at BASE and IP; 4 subjects were the most dehydrated (−6.1±1.1% body mass IP vs. BASE) and 4 were the least dehydrated at IP (−2.0±1.3% IP vs. BASE). mRNAs were sequenced on the HiSeq2500. All samples had a minimum of 43.5 million passed‐filter reads and aligned at >81% efficiency to the reference genome (Ensembl Biomart 72 hsa37). Effect of time point and hydration state at IP was assessed via ANOVA (Tukey post hoc comparisons) (R 3.0). FDR were calculated from p‐values using Benjamini and Hochberg methods. Of the pathways enriched (p<0.05) in the most dehydrated subjects at IP included ribosome, lysosome, and ion channel functions, while pathways significantly different in the less dehydrated subjects included genes primarily in macronutrient metabolic pathways. These findings suggest that great dehydration enhances cell organelle and membrane activities whereas mild dehydration enhances metabolism in response to exercise‐heat stress. Support or Funding Information Timex, Inc.