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In striated muscle, the sarcomeric protein myosin-binding protein-C (MyBP-C) is bound to the myosin thick filament and is predicted to stabilize myosin heads in a docked position against the thick filament, which limits crossbridge formation. Here, we use the homozygous Mybpc2 knockout (C2) mouse line to remove the fast-isoform MyBP-C from fast skeletal muscle and then conduct mechanical functional studies in parallel with small-angle X-ray diffraction to evaluate the myofilament structure. We report that C2 fibers present deficits in force production and calcium sensitivity. Structurally, passive C2 fibers present altered sarcomere length-independent and -dependent regulation of myosin head conformations, with a shift of myosin heads towards actin. At shorter sarcomere lengths, the thin filament is axially extended in C2, which we hypothesize is due to increased numbers of low-level crossbridges. These findings provide testable mechanisms to explain the etiology of debilitating diseases associated with MyBP-C.
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http://dx.doi.org/10.1038/s42003-024-06265-8 | DOI Listing |
Eur J Heart Fail
September 2025
School of Cardiovascular & Metabolic Medicine and Science, James Black Centre, King's College London British Heart Foundation Centre of Excellence, London, UK.
Aims: Skeletal muscle energetic augmentation might be a mechanism via which intravenous iron improves symptoms in heart failure, but no direct measurement of intrinsic mitochondrial function has been performed to support this notion. This molecular substudy of the FERRIC-HF II trial tested the hypothesis that ferric derisomaltose (FDI) would improve electron transport chain activity, given its high dependence on iron-sulfur clusters which facilitate electron transfer during oxidative phosphorylation.
Methods And Results: Vastus lateralis skeletal muscle biopsies were taken before and 2 weeks after randomization.
J Obes Metab Syndr
September 2025
Department of Endocrinology and Metabolism, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Background: This study explores how relative skeletal muscle mass is associated with the development of metabolic dysfunction-associated steatotic liver disease (MASLD) and the remission of baseline MASLD in a community-based population cohort.
Methods: The study included 1,544 participants with an average age of 58 years. All participants underwent baseline and follow-up assessments in 2015 or 2016.
Oral Surg Oral Med Oral Pathol Oral Radiol
August 2025
Chief Nurse of Dental Science, State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China. Electronic address:
Objective: This study aimed to investigate the effects of structured orofacial muscle rehabilitation training (OMRT) on the recovery of facial expression muscles in patients with skeletal Class II malocclusion after orthognathic surgery.
Study Design: This randomized controlled trial enrolled 56 skeletal Class II malocclusion patients who underwent orthognathic surgery. The intervention group received structured OMRT, while the control group received standard postoperative care.
Biophys Rep (N Y)
September 2025
Cellular Signal Transduction in the Cardiovascular System COBRE, University of Nevada Reno, Reno, NV 89557; Department of Nutrition, University of Nevada Reno, Reno, NV 89557. Electronic address:
Skeletal muscle alpha actin (ACTA1) is important for muscle contraction and relaxation, with historical studies focused on ACTA1 mutations in muscle dysfunction. Proteomics reports have consistently observed that actin, including ACTA1, is acetylated at multiple lysine sites. However, few reports have studied the effects of actin acetylation on cellular function, and fewer have examined ACTA1 acetylation on skeletal muscle function.
View Article and Find Full Text PDFJ Physiol
September 2025
Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia, USA.
Cognitive decline and physical impairment are often linked with ageing, contributing to declines in health span and loss of independence in older adults. Pathological cognitive decline with age is largely considered to be a brain-centric challenge. However, recent findings have begun to challenge this paradigm as the health of peripheral systems, namely skeletal muscle, predict cognitive decline associated with Alzheimer's disease (AD).
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