ECSS Paris 2023: CP-PN06
INTRODUCTION: Antimicrobial peptides LL-37, present in the saliva, has an important role in oral immune function. LL-37 exerts antimicrobial activity by disrupting the membranes of bacterial and viral cells. A few studies indicated an increase in salivary LL-37 secretion after high-intensity and long-duration acute exercise [1, 2]. However, it remains unclear whether the acute effects of different exercise intensities or durations on salivary LL-37 secretion. This study aimed to clarify the acute effects of different exercise intensities and durations on the secretion of LL-37 in saliva. METHODS: Fourteen healthy young men (age: 21.6 ± 1.6 years, height: 173.8 ± 3.8 cm, weight: 63.8 ± 6.0 kg, VO2max: 42.0 ± 4.7 ml/kg/min) with no exercise habits participated in this study. Maximal oxygen uptake (VO2max) was measured approximately 1 week before the main trials. All participants randomly performed [Intensity study] cycling exercise for 30 minutes at 35% (Low), 55% (Moderate), and 75%VO2max (High) and [Duration study] cycling exercise for 30 (Short), 60 (Middle), and 90-minutes (Long) at 55%VO2max. Saliva samples were collected before (baseline), immediately after (post), and 60 minutes after exercise (post-60 min) each trial. The salivary LL-37 concentrations were measured by enzyme-linked immunoassay. The effects of different exercise intensities (Low, Moderate, High) or durations (Short, Middle, Long) were determined using three trials × three time points (baseline, post, and post-60 min each exercise) of two-way repeated-measures ANOVA. A p<0.05 was considered statistically significant. RESULTS: In the intensity study, no significant differences in the percentage change from baseline were observed in salivary LL-37 concentration at post as well as post-60 min among the Low, Moderate, and High trials. In the duration study, the percentage change from baseline in salivary LL-37 concentration at post significantly increased by 40.7% in the Middle trial and 58.6% in the Long trial compared to the Short trial (each p<0.05). However, no significant differences were observed in the percentage change in salivary LL-37 concentration at post-60 min compared to baseline among the three different exercise durations trials. CONCLUSION: These results suggest that salivary LL-37 secretion may be independent of exercise intensity and may be stimulated depending on exercise duration.
Read CV Reita ItoECSS Paris 2023: CP-PN06
INTRODUCTION: Whole-body cryostimulation (WBC) offers preventive and therapeutic benefits, including enhanced metabolism, anti-inflammatory effects, and increased antioxidant defense, but the mechanism of these effects is unknown. This study aims to evaluate the impact of repeated WBC sessions on the expression of key genes involved in these responses, particularly in young, trained, and untrained males. METHODS: The study involved 28 young healthy Caucasian males, comprising 10 non-training individuals (NTR), 10 non-training men undergoing WBC (NTR-WBC), and 8 long-distance runners undergoing WBC (TR-WBC). Over an 8-week period, NTR-WBC and TR-WBC groups underwent 24 WBC treatments lasting 3 minutes at -130°C, three times weekly (Monday, Wednesday, Friday). Blood samples were collected before starting WBC and after the 1st, 12th, and 24th session. mRNA expressions of glutathione synthetase (GSS), superoxide dismutase 2 (SOD2), sirtuin 1 (SIRT1), sirtuin 3 (SIRT3), and intercellular adhesion molecule 1 (ICAM-1) in mononuclear blood cells were determined. RESULTS: Following the first WBC session, the TR-WBC group exhibited increased mRNA levels of SIRT1 (p = 0.01), SIRT3 (p = 0.05), and SOD (p = 0.04), GSS mRNA expression rose in both groups, with statistical significance in the NTR-WBC group (p = 0.05). After 12 WBC sessions, significant elevation in SIRT1 mRNA levels was observed in the TR-WBC group (p = 0.02), while the NTR-WBC group showed a statistically significant rise in SOD and ICAM-1 mRNA levels (p = 0.05 for both). By the 24th WBC session, the TR-WBC group showed marked increases in SIRT1 (p < 0.01) and SOD2 (p = 0.02), along with a decrease in ICAM-1 mRNA levels (p = 0.03). In the NTR-WBC group, changes in mRNA expressions of these genes were also noted (SIRT1: p = 0.05, SOD: p = 0.04, ICAM-1: p = 0.05). CONCLUSION: WBC treatments enhances sirtuins expression, important for antioxidant defense systems and inflammatory responses in young men, dependent on physical activity level and number of treatments.
Read CV MARIA LIPOWSKAECSS Paris 2023: CP-PN06
INTRODUCTION: After the COVID-19 pandemic, ACE2 has garnered substantial attention due to its pivotal role as the primary entry receptor for SARS-CoV-2 into host cells. Our recent study highlights the abundant presence of ACE2 protein in human skeletal muscle, which varies between sexes [1]. Elevated ACE2 protein levels may enhance infection, while diminished levels have been linked to age-related muscle mass decline, potentially exacerbating inflammation and influencing disease severity. As a key antioxidant and anti-inflammatory defence mechanism, NRF2 may exhibit a complex interaction with ACE2, suggesting a role in modulating oxidative stress responses and maintaining cellular homeostasis [2]. Moreover, ACE2 protein expression has been linked to brain and muscle Arnt-like protein 1 (BMAL1), a circadian rhythm signal, indicating temporal fluctuations influenced by circadian and environmental factors [3]. Understanding protein expression dynamics across different time points in skeletal muscle could provide crucial insights and refine biopsy extraction methodologies. METHODS: Twelve volunteers (6 males and 6 females) participated in our study. Following a 12-hour fasting period, biopsies of the vastus lateralis muscle were taken from randomly selected legs at five time points (baseline, 4h, 8h, 12h, and 24h), totalling 60 biopsies. Leg allocation for biopsy was randomized but consistent for each participant. We ensured strict adherence to biopsy time intervals. Protein expression levels were analysed using Western Blot. Temporal changes were assessed via ANOVA in SPSS, while correlations were explored using mixed linear models in JAMOVI. RESULTS: Compared to baseline levels, ACE2 protein expression increased by 1.9 and 1.7-fold after 4 and 8 hours, respectively (p<0.05). Similarly, significant increases were observed in BMAL (1.6-fold and 1.4-fold) and Nrf2 (2 and 1.5-fold) expression at the same time points (p<0.05). Strong linear associations were found between ACE2 and NRF2 (R² marginal=0.71, R² conditional=0.94, p<0.01) and between ACE2 and BMAL (R² marginal=0.73, R² conditional=0.84, p<0.01). Both genders showed similar responses. CONCLUSION: Our study highlights the temporal modulation of ACE2 and Nrf2 protein expression in skeletal muscle, possibly influenced by circadian rhythms. This regulatory mechanism may significantly contribute to maintaining cellular homeostasis and responding to hormonal signals. Moreover, understanding the dynamic interplay of these signals reveals intricate mechanisms governing oxidative stress responses and circadian regulation within skeletal muscle. Considering biopsy timing in skeletal muscle signalling research is crucial for accurately capturing intervention-related changes and properly interpreting results. GRANT: PID2021-125354OB-C21 and PID2021-125354OB-C22. 1. Perez-Valera M, et al. Scand J Med Sci Sports. 2021; 31(12):2249-2258 2. Wang, Y. et al. Cell Stress Chaperones. 2023; 28(1):11-20. 3. Zlacká J, et al. Physiol Res. 2021; 70: S177-S194.
Read CV GALLEGO SELLES ANGELECSS Paris 2023: CP-PN06