1
|
King KE, McCormick JJ, McManus MK, Janetos KMT, Goulet N, Kenny GP. Impaired autophagy following ex vivo cooling of simulated hypothermic temperatures in peripheral blood mononuclear cells from young and older adults. J Therm Biol 2024; 121:103831. [PMID: 38565070 DOI: 10.1016/j.jtherbio.2024.103831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/20/2023] [Accepted: 03/13/2024] [Indexed: 04/04/2024]
Abstract
Hypothermia is a critical consequence of extreme cold exposure that increases the risk of cold-related injury and death in humans. While the initiation of cytoprotective mechanisms including the process of autophagy and the heat shock response (HSR) is crucial to cellular survival during periods of stress, age-related decrements in these systems may underlie cold-induced cellular vulnerability in older adults. Moreover, whether potential sex-related differences in autophagic regulation influence the human cold stress response remain unknown. We evaluated the effect of age and sex on mechanisms of cytoprotection (autophagy and the HSR) and cellular stress (apoptotic signaling and the acute inflammatory response) during ex vivo hypothermic cooling. Venous blood samples from 20 healthy young (10 females; mean [SD]: 22 [2] years) and 20 healthy older (10 females; 66 [5] years) adults were either isolated immediately (baseline) for peripheral blood mononuclear cells (PBMCs) or exposed to water bath temperatures maintained at 37, 35, 33, 31, or 4 °C for 90 min before PBMC isolation. Proteins associated with autophagy, apoptosis, the HSR, and inflammation were analyzed via Western blotting. Indicators of autophagic initiation and signaling (LC3, ULK1, and beclin-2) and the HSR (HSP90 and HSP70) increased when exposed to hypothermic temperatures in young and older adults (all p ≤ 0.007). Sex-related differences were only observed with autophagic initiation (ULK1; p = 0.015). However, despite increases in autophagic initiators ULK1 and beclin-2 (all p < 0.001), this was paralleled by autophagic dysfunction (increased p62) in all groups (all p < 0.001). Further, apoptotic (cleaved-caspase-3) and inflammatory (IL-6 and TNF-α) signaling increased in all groups (all p < 0.001). We demonstrated that exposure to hypothermic conditions is associated with autophagic dysfunction, irrespective of age or sex, although there may exist innate sex-related differences in cytoprotection in response to cold exposure as evidenced through altered autophagic initiation.
Collapse
Affiliation(s)
- Kelli E King
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - James J McCormick
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Morgan K McManus
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Kristina-Marie T Janetos
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Nicholas Goulet
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada; Behavioural and Metabolic Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
| |
Collapse
|
2
|
Goulet N, Tetzlaff EJ, McCormick JJ, King KE, Janetos KMT, Sigal RJ, Boulay P, Kenny GP. Greater hyperthermia in men with type 2 diabetes does not lead to higher serum levels of cellular stress biomarkers following exercise-heat stress. Appl Physiol Nutr Metab 2024. [PMID: 38507777 DOI: 10.1139/apnm-2023-0599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Type 2 diabetes (T2D) is associated with worsening age-related impairments in heat loss, causing higher core temperature during exercise. We evaluated whether these thermoregulatory impairments occur with altered serum protein responses to heat stress by measuring cytoprotection, inflammation, and tissue damage biomarkers in middle-aged-to-older men (50-74 years) with (n = 16) and without (n = 14) T2D following exercise in 40°C. There were no changes in irisin, klotho, HSP70, sCD14, TNF-α, and IL-6, whereas NGAL (+539 pg/mL, p = 0.002) and iFABP (+250 pg/mL, p < 0.001) increased similarly across groups. These similar response patterns occurred despite elevated core temperature in individuals with T2D, suggesting greater heat vulnerability.
Collapse
Affiliation(s)
- Nicholas Goulet
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
- Behavioural and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Emily J Tetzlaff
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - James J McCormick
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Kelli E King
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Kristina-Marie T Janetos
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Ronald J Sigal
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
- Departments of Medicine, Cardiac Sciences, and Community Health Sciences, Cumming School of Medicine, Faculties of Medicine and Kinesiology, University of Calgary, Calgary, AB, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Pierre Boulay
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| |
Collapse
|
3
|
McGarr GW, King KE, Cassan CJM, Janetos KMT, Fujii N, Kenny GP. Involvement of nitric oxide synthase and reactive oxygen species in TRPA1-mediated cutaneous vasodilation in young and older adults. Microvasc Res 2023; 145:104443. [PMID: 36208670 DOI: 10.1016/j.mvr.2022.104443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/25/2022] [Accepted: 10/02/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To investigate the nitric oxide synthase (NOS) and reactive oxygen species (ROS) contributions of the cutaneous vasodilator response to transient receptor potential ankyrin-1 channel (TRPA1) activation in young and older adults. MATERIALS AND METHODS In sixteen young (20 ± 2 years, 8 females) and sixteen older adults (61 ± 5 years, 8 females), cutaneous vascular conductance normalized to maximum vasodilation (%CVCmax) was assessed at four dorsal forearm skin sites continuously perfused via microdialysis with: 1) vehicle solution (Control, 2 % dimethyl sulfoxide, 2 % Ringer, 96 % propylene glycol), 2) 10 mM Ascorbate (non-specific ROS inhibitor), 3) 10 mM L-NAME (non-specific NOS inhibitor), or 4) Ascorbate+L-NAME. The TRPA1 agonist cinnamaldehyde was co-administered at all sites [0 % (baseline), 2.9 %, 8.8 %, 26.4 %; ≥ 30 min per dose]. RESULTS %CVCmax was not different between groups for Control, L-NAME, and Ascorbate (all p > 0.05). However, there were significant main dose effects for each site wherein %CVCmax was greater than baseline from 2.9 % to 26.4 % cinnamaldehyde for Control and Ascorbate, and at 26.4 % cinnamaldehyde for L-NAME and Ascorbate+L-NAME (all p < 0.05). For Ascorbate+L-NAME, there was a significant main group effect, wherein perfusion was 6 %CVCmax [95% CI: 2, 11, p < 0.05] greater in the older compared to the young group across all cinnamaldehyde doses. There was a significant main site effect for area under the curve wherein L-NAME and Ascorbate+L-NAME were lower than Control and Ascorbate across groups (all p < 0.05). CONCLUSION The NOS-dependent cutaneous vasodilator response to TRPA1 activation is maintained in older adults, with no detectable contribution of ascorbate-sensitive ROS in either age group.
Collapse
Affiliation(s)
- Gregory W McGarr
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Kelli E King
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Casey J M Cassan
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Kristina-Marie T Janetos
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Naoto Fujii
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada; Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba City, Japan; Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada.
| |
Collapse
|