Filamin A cooperates with the androgen receptor in preventing skeletal muscle senescence

Effect of Mutations in the C-Terminal 22-24 Domains of Filamin C Associated with Cardio- and Myopathies on Its Interaction with Small Heat Shock Protein HspB7

We investigated the interaction of HspB7 and its α-crystallin domain with the wild-type (WT) C-terminal fragment of human filamin C (FLNC), containing immunoglobulin-like domains 22-24 and its three mutants associated with cardio- and myopathies. The physicochemical properties of the WT FLNC fragment and its three mutants, p.Glu2472_Asn2473delinsAsp (EN/D) located in the 22nd domain, p.P2643_L2645del (ΔPGL), and p.W2710X (Wmut) both located in the 24th immunoglobulin-like domain were analyzed. Although all FLNC fragments had similar secondary structures, WT FLNC and its EN/D and ΔPGL mutants formed dimers, whereas Wmut formed either monomers or aggregates. The surface hydrophobicity of EN/D, ΔPGL, and especially Wmut mutants was larger than that of the WT fragment. Size exclusion chromatography, native gel electrophoresis, and chemical crosslinking indicated that the efficiency of interaction with HspB7 or its α-crystallin domain decreased in the order WT~EN/D > ΔPGL. Wmut was unable to interact with either HspB7 or its α-crystallin domain. Modeling via Alphafold 3 indicated that EN/D mutation affected the orientation of two loops connecting β-strands in the 22nd domain, while the ΔPGL and Wmut mutations exposed a hydrophobic groove in the 24th domain thereby reducing their interaction with HspB7. These findings reveal the molecular mechanisms underlying filaminopathies associated with three mutations in the C-terminal region of filamin C.

Androgens as the "old age stick" in skeletal muscle

Aging is associated with a reduction in skeletal muscle fiber size and number, leading to a decline in physical function and structural integrity-a condition known as sarcopenia. This syndrome is further characterized by elevated levels of inflammatory mediators that promote skeletal muscle catabolism and reduce anabolic signaling.Androgens are involved in various biological processes, including the maintenance, homeostasis and trophism of skeletal muscle mass. The decline in androgen levels contributes, indeed, to androgen deficiency in aging people. Such clinical syndrome exacerbates the muscle loss and fosters sarcopenia progression. Nevertheless, the mechanism(s) by which the reduction in androgen levels influences sarcopenia risk and progression remains debated and the therapeutic benefits of androgen-based interventions are still unclear. Given the significant societal and economic impacts of sarcopenia, investigating the androgen/androgen receptor axis in skeletal muscle function is essential to enhance treatment efficacy and reduce healthcare costs.This review summarizes current knowledge on the role of male hormones and their-dependent signaling pathways in sarcopenia. We also highlight the cellular and molecular features of this condition and discuss the mechanisms by which androgens preserve the muscle homeostasis. The pros and cons of clinical strategies and emerging therapies aimed at mitigating muscle degeneration and aging-related decline are also presented.

Exploring Gender-Specific Correlations Between Nutritional Intake, Body Composition, Psychological Skills, and Performance Metrics in Young Taekwondo Athletes

Objectives: Taekwondo performance is influenced by a complex and dynamic interplay of physical, nutritional, and psychological factors, all of which contribute to competitive success. However, the gender-specific relationships among these factors in young high-performance athletes remain understudied. This study aimed to fill in this knowledge gap. Methods: A cross-sectional study was conducted with 35 elite taekwondo athletes (male: n = 20, female: n = 15, age: 13 ± 1 years). Participants underwent anthropometric assessments, dietary evaluations, and psychological skill assessments during an 8-week training camp before the World Taekwondo Championships. Physical performance was assessed using the Frequency Speed of Kick Test (FSKTmult) and the Taekwondo-Specific Agility Test (TSAT). Statistical analyses included independent t-tests, correlation analyses, and regression models. Results: Males exhibited significantly higher fat-free mass (FFM: 42.8 ± 2.9 kg vs. 36.3 ± 1.6 kg, p < 0.001), skeletal muscle mass (SMM: 31.1 ± 2.2 kg vs. 28.2 ± 1.6 kg, p < 0.001), and energy intake (32.4 ± 4.6 kcal/kg vs. 29.3 ± 3.1 kcal/kg, p = 0.032) than females. Males also had greater dietary intakes of vitamin A, vitamin C, magnesium, and iron (all p < 0.05). There were no gender differences in any psychological attributes associated with emotional intelligence, sport success perception, and mental toughness. Although the total kick count in the FSKTmult was similar for male and female taekwondo athletes (100.2 ± 4.6 vs. 97.5 ± 5.9 kicks, p = 0.139), males outperformed females in round 4 (19.4 ± 1.1 vs. 18.6 ± 1.4 kicks, p = 0.048) and round 5 (18.2 ± 1.0 vs. 17.2 ± 1.0 kicks, p = 0.007) of this test, suggesting higher physical performance maintenance during the test. Regression models indicated that body mass (β = 0.901, p < 0.001) and calcium intake (β = 0.284, p = 0.011) predicted performance in males, while body mass (β = 1.372, p < 0.001), protein intake (β = 0.171, p = 0.012), and emotional regulation (β = 0.174, p = 0.012) were key predictors in females. Conclusions: These findings highlight the importance of an integrated approach to training, nutrition, and psychological preparation in optimizing taekwondo performance. While males and females demonstrated similar psychological resilience and total kick output in a taekwondo-specific test, males exhibited superior endurance in later test rounds of this test. Performance optimization in young elite taekwondo athletes may require the implementation of gender-specific training and nutrition strategies, emphasizing body weight control and calcium intake for males and protein intake for females.

Role of Filamin A in Growth and Migration of Breast Cancer-Review

Despite ongoing research in the field of breast cancer, the morbidity rates indicate that the disease remains a significant challenge. While patients with primary tumors have relatively high survival rates, these chances significantly decrease once metastasis begins. Thus, exploring alternative approaches, such as targeting proteins overexpressed in malignancies, remains significant. Filamin A (FLNa), an actin-binding protein (ABP), is involved in various cellular processes, including cell migration, adhesion, proliferation, and DNA repair. Overexpression of the protein was confirmed in samples from patients with numerous oncological diseases such as prostate, lung, gastric, colorectal, and pancreatic cancer, as well as breast cancer. Although most researchers concur on its role in promoting breast cancer progression and aggressiveness, discrepancies exist among studies. Moreover, the precise mechanisms through which FLNa affects cell migration, invasion, and even cancer progression remain unclear, highlighting the need for further research. To evaluate FLNa's potential as a therapeutic target, we have summarized its roles in breast cancer.

Molecular and Structural Alterations of Skeletal Muscle Tissue Nuclei during Aging

Aging is accompanied by a progressive loss of skeletal muscle mass and strength. The mechanisms underlying this phenomenon are certainly multifactorial and still remain to be fully elucidated. Changes in the cell nucleus structure and function have been considered among the possible contributing causes. This review offers an overview of the current knowledge on skeletal muscle nuclei in aging, focusing on the impairment of nuclear pathways potentially involved in age-related muscle decline. In skeletal muscle two types of cells are present: fiber cells, constituting the contractile muscle mass and containing hundreds of myonuclei, and the satellite cells, i.e., the myogenic mononuclear stem cells occurring at the periphery of the fibers and responsible for muscle growth and repair. Research conducted on different experimental models and with different methodological approaches demonstrated that both the myonuclei and satellite cell nuclei of aged skeletal muscles undergo several structural and molecular alterations, affecting chromatin organization, gene expression, and transcriptional and post-transcriptional activities. These alterations play a key role in the impairment of muscle fiber homeostasis and regeneration, thus contributing to the age-related decrease in skeletal muscle mass and function.