Dehydration Alters PBMC Inflammatory Propensity That Impair Myoblast Fusion: An Ex-Vivo Approach

Authors

Casey Appell, Texas Tech UniversityFollow
Trinity N. Domonkos, Texas Tech UniversityFollow
Karina Olvera, Texas Tech UniversityFollow
Sarah Walper, Texas Tech UniversityFollow
Christian J. Hoebelheinrich, Texas Tech UniversityFollow
Larry Munger, Texas Tech University Health Sciences CenterFollow
Danielle Levitt, Texas Tech UniversityFollow
Hui-Ying Luk, Texas Tech UniversityFollow

Abstract

Muscle recovery from damage requires satellite cell activation to myoblasts and subsequent myoblast fusion, processes that are influenced, by immune-muscle crosstalk. In this context, the inflammatory propensity of peripheral blood mononuclear cells (PBMCs), may alter myoblast fusion. In vitro studies have shown that hyperosmotic stress alters PBMC inflammatory potency. However, the effect of dehydration (elevated plasma osmolality) on PBMC inflammatory propensity, and its impact on myoblast fusion is unknown. PURPOSE: To determine the effect of dehydration following muscle damage on PBMC inflammatory propensity to alter myoblast fusion using an ex-vivo model. METHODS: Active men (n=4, 19±1yr, 173.4±7.6cm, 84.3±11.6kg) completed two identical unilateral maximal eccentric knee extensions protocols (EIMD; 10 sets × 30 reps) in a hydrated state to induce muscle damage. Following EIMD, participants underwent 24hr of recovery under either euhydrated (HYD) or dehydrated (DEH) conditions. For DEH, no fluid was consumed for 24hr. For HYD, participants consumed >3.7L for 24hr. Venous blood collected from HYD and DEH conditions 24hr after EIMD was used to isolate PBMCs, which were cultured for 24hr with or without LPS stimulation (HYD/LPS^-, HYD/LPS⁺, DEH/LPS^-, DEH/LPS^+­). Culture supernatants were collected. After 3-d of proliferation, human primary myoblasts were differentiated in RPMI supplemented with 5% vol/vol PBMC supernatant from each group, or in RPMI with (CON/LPS⁺) or without LPS (CON/LPS^-) for 4 (4D) or 7 (7D) days. Separate myoblast cultures were assessed for each group in duplicate (n=24). Cells were visualized using HEMA3 staining. Myoblast fusion index (FI), defined as ≥2 fused nuclei, was manually quantified in ImageJ and normalized per 100 cells. Data were analyzed by three-way repeated measures ANOVA (condition × stimulation × time). RESULTS: A significant (pp=0.027) and HYD (24±1; p=0.015). This difference could be driven by the DEH/LPS⁺ because a trend (p=0.058; η_p²=0.612) for a 3-way interaction effect where DEH/LPS⁺ had the lowest FI than all other groups with or without LPS. CONCLUSION: This preliminary data suggests that dehydration could alter the PBMC inflammatory propensity, and that these PBMC-derived factors impaired myoblast fusion. Given the role of myoblast fusion in muscle recovery, the long-term effect of underhydration on muscle recovery warrants further investigation.

Recommended Citation

Appell, Casey; Domonkos, Trinity N.; Olvera, Karina; Walper, Sarah; Hoebelheinrich, Christian J.; Munger, Larry; Levitt, Danielle; and Luk, Hui-Ying (2026) "Dehydration Alters PBMC Inflammatory Propensity That Impair Myoblast Fusion: An Ex-Vivo Approach," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 168.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/168