Thesis
An investigation on the effects of downhill treadmill running and intramuscular needling on mitochondrial Ca2+ overload in skeletal muscle: From the perspective of Ca2+ transport from sarcoplasmic reticulum to mitochondria
Southern Cross University
Doctor of Philosophy (PhD), Southern Cross University
2023
DOI:
https://doi.org/10.25918/thesis.309
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Abstract
Objective: It is known that an unaccustomed downhill running can cause skeletal muscle damage and impair muscle function, which could be related to mitochondrial Ca2+ overload. It is also known that intramuscular needling after exercise can reduce muscle injury. However, the mechanisms underlying the exercise-induced muscle damage and the improving effect of intramuscular needling have not been fully elucidated. This research aimed to reveal the mechanisms, from the perspective of Ca2+ transport mediated by mitochondria-associated membrane (MAM) complex.
Methods: An exercised-induced muscle damage model was established as Sprague Dawley rats undertook one-bout of 90 minutes downhill treadmill running exercise. Immediately after the exercise, half of the rats were treated with the intramuscular needling on the vastus lateralis of the left leg for two minutes. Immediately after, 12 hours after and 72 hours after the exercise and or needling, the muscle was excised. The structures of mitochondria and MAM were observed by transmission electron microscopy, and the number of MAM per vision field was counted; the Ca2+ concentration in mitochondria and sarcoplasmic reticulum were detected by fluorescence probes, the mitochondrial 1,1',3,3'-tetraethyl-5,5',6,6'-tetrachloroimidacarbocyanine iodide fluorescence ratio was detected by ELISA Kit as an indication of the inner mitochondrial membrane potential, and cytochrome c oxidase subunit IV activity was also measured by ELISA Kit as an indication of the change in mitochondrial function. The interactions among the components of the MAM Ca2+ transport complex, inositol 1,4,5-triphase receptor (IP3R), glucose-regulated protein 75 (Grp75) and voltage-dependent anion-selective channel protein 1 (VDAC1), were examined by co-immunoprecipitation technique, and the expressions of IP3R, Grp75 and VDAC1 proteins were measured by Western blot. The levels of the co-localisation of ryanodine receptor and translocase of outer mitochondrial membrane 20, IP3R and Grp75, Grp75 and VDAC1 and IP3R and VDAC1 were measured by an immunofluorescence method for reflecting the changes in the protein complex of IP3R-Grp75-VDAC1 in response to the exercise and or needling.
Major findings: (1) the one-bout of downhill running resulted in an excessive increase in mitochondrial Ca2+ concentration, causing damage to mitochondrial structure and function in the vastus lateralis, which was regarded as mitochondrial Ca2+ overload and was recovered at 72 h after the exercise; (2) the exercise-induced mitochondrial Ca2+ increase occurred with an increased formation of Ca2+ transport complex of IP3R-Grp75-VDAC1; (3) the intramuscular needling treatment alleviated exercise-induced mitochondrial Ca2+ increase in the treated muscle by suppressing the formation the IP3R-Grp75-VDAC1 complex; and (4) the unilateral intramuscular needling reduced the formation of the IP3R-Grp75-VDAC1 complex in the vastus lateralis of the contralateral leg, demonstrating a cross-education effect.
Details
- Title
- An investigation on the effects of downhill treadmill running and intramuscular needling on mitochondrial Ca2+ overload in skeletal muscle: From the perspective of Ca2+ transport from sarcoplasmic reticulum to mitochondria
- Creators
- Shuangshuang Zhang
- Contributors
- Shi Zhou (Supervisor) - Southern Cross UniversityZachary J Crowley-McHattan (Supervisor) - Southern Cross UniversityRuiyuan Wang (Supervisor) - Beijing Sport University
- Awarding Institution
- Southern Cross University; Doctor of Philosophy (PhD)
- Theses
- Doctor of Philosophy (PhD), Southern Cross University
- Publisher
- Southern Cross University
- Number of pages
- 267
- Identifiers
- 991013143813702368
- Copyright
- © Shuangshuang Zhang 2023
- Academic Unit
- Faculty of Health
- Resource Type
- Thesis