Irving 2017 MiP2017
Recent evidence suggests that defects in mitochondrial respiratory function in peripheral blood mononuclear cells (PBMCs) may contribute to the development of systemic inflammation, oxidative stress, and cardiometabolic risk. Recently, chronic exercise training has been reported to alleviate hypoxia-induced mitochondrial dysfunction in lymphocytes. Moreover, acute exercise mobilizes tissue-residing immune cell sub-types in the peripheral blood compartment especially, highly differentiated proinflammatory T-cells. However, the impact that acute exercise has on PBMC respiratory function is largely unknown. Thus, we sought to determine the effect of an acute bout of maximal exercise on PBMC mitochondrial respiratory function using high-resolution respirometry. Specifically, we collected baseline and immediate post-exercise blood samples from an antecubital vein in 4x10mL collection tubes spray-coated with K2EDTA (BD vacutainer, NJ, USA) from 12 collegiate swimmers. Total blood lymphocyte numbers and phenotypes were characterized by flow cytometry (BD Accuri C6, BD Biosciences, Ann Arbor, MI, USA) and using a clinical hematology analyzer (Beckman Coulter, CA, USA). Fresh PBMCs were isolated as previously described. Briefly, blood samples were diluted in equal volume of Phosphate Buffer Saline and layered on density-gradient media (Histopaque, Sigma Aldrich, MO, USA) before being centrifuged at 800g for 30 minutes. The freshly isolated PBMC were washed 2x at room temperature in PBS and resuspended in MiR05. We added ~4-5 million cells (1ce) per chamber in MiR05 and measured endogenous ROUTINE respiration. We then added pyruvate and malate (2PM; exogenous substrate) and digitionin (0.8 uL per millions cells) to measure LEAK respiration. Subsequently, we sequentially added 10 uL ADP (3D), cytochrome c (3Dc), and glutamate (4G) to measure N-linked oxidative capacity (OXPHOS). We then added succinate (5S) to measures NS-linked OXPHOS, followed by CCCP titration (6U) to measure ET capacity, and antimycin A (7Ama) to measure residual oxygen consumption (ROX). Overall, there was a significant increase in ROUTINE respiration following the acute bout of exercise (4.3±0. 4 vs. 3.8±0.4 pmols/sec/million, p<0.05). There were no differences in LEAK, N-linked OXPHOS, NS-linked OXPHOS, or ET-pathway (p>0.05). In conclusion, ROUTINE respiration in freshly isolated PBMC cells is elevated in college swimmers in response to an acute bout of exercise. Finally, we will also discuss some methodological consideration with regards to sample preparation.
Labels: MiParea: Respiration, Exercise physiology;nutrition;life style
Tissue;cell: Blood cells
Coupling state: LEAK, ROUTINE, OXPHOS, ET Pathway: N, NS, ROX HRR: Oxygraph-2k
- Li P, Wang B, Sun F, Li Y, Li Q, Lang H, Zhao Z, Gao P, Zhao Y, Shang Q, Liu D, Zhu Z (2015) Mitochondrial respiratory dysfunctions of blood mononuclear cells link with cardiac disturbance in patients with early-stage heart failure. Sci Rep 5:10229.
- Tsai HH, Chang SC, Chou CH, Weng TP, Hsu CC, Wang JS (2016) Exercise training alleviates hypoxia-induced mitochondrial dysfunction in the lymphocytes of sedentary males. Sci Rep 6:35170.
- Spielmann G, McFarlin BK, O'Connor DP, Smith PJ, Pircher H, Simpson RJ (2011) Aerobic fitness is associated with lower proportions of senescent blood T-cells in man. Brain Behav Immun 25:1521-9.