Background: We tested whether enhancing the capacity for calcium/calmodulin-dependent protein kinase type II (CaMKII) signaling would delay fatigue of excitation-induced calcium release and improve contractile characteristics of skeletal muscle during fatiguing exercise.
Methods: Fast and slow type muscle, gastrocnemius medialis (GM) and soleus (SOL), of rats and mouse interosseus (IO) muscle fibers, were transfected with pcDNA3-based plasmids for rat α and β CaMKII or empty controls. Levels of CaMKII, its T287-phosphorylation (pT287-CaMKII), and phosphorylation of components of calcium release and re-uptake, ryanodine receptor 1 (pS2843-RyR1) and phospholamban (pT17-PLN), were quantified biochemically. Sarcoplasmic calcium in transfected muscle fibers was monitored microscopically during trains of electrical excitation based on Fluo-4 FF fluorescence (n = 5-7). Effects of low- (n = 6) and high- (n = 8) intensity exercise on pT287-CaMKII and contractile characteristics were studied in situ.
Results: Co-transfection with αCaMKII-pcDNA3/βCaMKII-pcDNA3 increased α and βCaMKII levels in SOL (+45.8 %, +250.5 %) and GM (+40.4 %, +89.9 %) muscle fibers compared to control transfection. High-intensity exercise increased pT287-βCaMKII and pS2843-RyR1 levels in SOL (+269 %, +151 %) and GM (+354 %, +119 %), but decreased pT287-αCaMKII and p17-PLN levels in GM compared to SOL (-76 % vs. +166 %; 0 % vs. +128 %). α/β CaMKII overexpression attenuated the decline of calcium release in muscle fibers with repeated excitation, and mitigated exercise-induced deterioration of rates in force production, and passive force, in a muscle-dependent manner, in correlation with pS2843-RyR1 and pT17-PLN levels (|r| > 0.7).
Conclusion: Enhanced capacity for α/β CaMKII signaling improves fatigue-resistance of active and passive contractile muscle properties in association with RyR1- and PLN-related improvements in sarcoplasmic calcium release.
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http://dx.doi.org/10.1016/j.bbamcr.2023.119610 | DOI Listing |
Mikrochim Acta
January 2025
Department of Chemistry, Sardar Vallabhbhai National Institute of Technology, Surat, Gujarat, 395 007, India.
A fluorescence "turn-off-on" nanoprobe is designed by using europium-doped strontium molybdate perovskite quantum dots (Eu:SMO PQDs) for the sequential detection of hypoxanthine (Hx) and Fe. The Eu:SMO PQDs were prepared by the sol-gel method using Sr(NO), (NH)MoO.4HO, and Eu(OCOCH) as precursors.
View Article and Find Full Text PDFAdv Healthc Mater
January 2025
College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, 130118, China.
Natural plant-derived polysaccharides exhibit substantial potential for treating ulcerative colitis (UC) owing to their anti-inflammatory and antioxidant properties and favorable safety profiles. However, their practical application faces several challenges, including structural instability in gastric acid, imprecise targeting of inflamed regions, and limited intestinal retention times. To address these limitations, pH-responsive, colon-targeting microspheres (pWGPAC MSs) are developed for delivering phosphorylated wild ginseng polysaccharides (pWGP) to alleviate UC.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok, Russia.
Inflammation is a physiological response of the immune system to infectious agents or tissue injury, which involves a cascade of vascular and cellular events and the activation of biochemical pathways depending on the type of harmful agent and the stimulus generated. The Kunitz peptide HCIQ2c1 of sea anemone is a strong protease inhibitor and exhibits neuroprotective and analgesic activities. In this study, we investigated the anti-inflammatory potential of HCIQ2c1 in histamine- and lipopolysaccharide (LPS)-activated RAW 264.
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Myology Laboratory, Institute of Biomedical Problems (IBP), RAS, 123007 Moscow, Russia.
During skeletal muscle unloading, phosphoinositide 3-kinase (PI3K), and especially PI3K gamma (PI3Kγ), can be activated by changes in membrane potential. Activated IP3 can increase the ability of Ca to enter the nucleus through IP3 receptors. This may contribute to the activation of transcription factors that initiate muscle atrophy processes.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dubravska cesta 9, 840 05 Bratislava, Slovakia.
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a highly arrhythmogenic syndrome triggered by stress, primarily linked to gain-of-function point mutations in the cardiac ryanodine receptor (RyR2). Flecainide, as an effective therapy for CPVT, is a known blocker of the surface-membrane Na channel, also affecting the intracellular RyR2 channel. The therapeutic relevance of the flecainide-RyR2 interaction remains controversial, as flecainide blocks only the RyR2 current flowing in the opposite direction to the physiological Ca release from the sarcoplasmic reticulum (SR).
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