Search Results (938)

Background: The candidate therapeutic peptide TnP demonstrates broad, system-level regulatory capacity, revealed through integrated network analysis from transcriptomic data in zebrafish. Our study primarily identifies TnP as a multifaceted modulator of drug metabolism, wound healing, proteolytic activity, and pigmentation pathways. Results: Transcriptomic profiling of TnP-treated larvae following tail fin amputation revealed 558 differentially expressed genes (DEGs), categorized into four functional networks: (1) drug-metabolizing enzymes (cyp3a65, cyp1a) and transporters (SLC/ABC families), where TnP alters xenobiotic processing through Phase I/II modulation; (2) cellular trafficking and immune regulation, with upregulated myosin genes (myhb/mylz3) enhancing wound repair and tlr5-cdc42 signaling fine-tuning inflammation; (3) proteolytic cascades (c6ast4, prss1) coupled to autophagy (ulk1a, atg2a) and metabolic rewiring (g6pca.1-tg axis); and (4) melanogenesis-circadian networks (pmela/dct-fbxl3l) linked to ubiquitin-mediated protein turnover. Key findings highlight TnP’s unique coordination of rapid (protease activation) and sustained (metabolic adaptation) responses, enabled by short network path lengths (1.6–2.1 edges). Hub genes, such as nr1i2 (pxr), ppara, and bcl6aa/b, mediate crosstalk between these systems, while potential risks—including muscle hypercontractility (myhb overexpression) or cardiovascular effects (ace2-ppp3ccb)—underscore the need for targeted delivery. The zebrafish model validated TnP-conserved mechanisms with human relevance, particularly in drug metabolism and tissue repair. TnP’s ability to synchronize extracellular matrix remodeling, immune resolution, and metabolic homeostasis supports its development for the treatment of fibrosis, metabolic disorders, and inflammatory conditions. Conclusions: Future work should focus on optimizing tissue-specific delivery and assessing genetic variability to advance clinical translation. This system-level analysis positions TnP as a model example for next-generation multi-pathway therapeutics. Full article

The C-kinase-activated protein phosphatase-1 (PP1) inhibitor of 17 kDa (CPI-17) is a specific inhibitor of the PP1 catalytic subunit (PP1c) and the myosin phosphatase (MP) holoenzyme. CPI-17 requires the phosphorylation of Thr38 in the peptide segment ³⁵ARV(P)TVKYDRREL⁴⁶ for inhibitory activity. CPI-17 regulates myosin phosphorylation in smooth muscle contraction and the tumorigenic transformation of several cell lines via the inhibition of MP. A phosphospecific antibody (anti-CPI-17^pThr38) against the phosphorylation peptide was used to determine the phosphorylation levels in cells. We found that phospho-CPI-17 and its closely related proteins are not present in HeLa and MCF7 cells after inducing phosphorylation by inhibiting phosphatases with calyculin A. In contrast, cross-reactions of proteins in the 40–220 kDa range with anti-CPI-17^pThr38 were apparent. Searching the protein database for similarities to the CPI-17 phosphorylation sequence revealed several proteins with 42–75% sequence identities. The LIMK2-1 isoform emerged as a possible PP1 inhibitor. Experiments with Flag-LIMK2-1 overexpressed in tsA201 cells proved that LIMK2-1 interacts with PP1c isoforms and is phosphorylated predominantly by protein kinase C. Phosphorylated LIMK2-1 inhibits PP1c and the MP holoenzyme with similar potencies (IC50 ~28–47 nM). In conclusion, our results suggest that LIMK2-1 is a novel phosphorylation-dependent inhibitor of PP1c and MP and may function as a CPI-17-like phosphatase inhibitor in cells where CPI-17 is present but not phosphorylated upon phosphatase inhibition. Full article

Hypertrophic cardiomyopathy (HCM) is a prevalent and often underdiagnosed genetic cardiac disorder characterized by left ventricular hypertrophy and, in many cases, dynamic left ventricular outflow tract obstruction (LVOTO). The development of cardiac myosin inhibitors (CMIs) represents an emerging therapeutic approach in the pharmacological management of obstructive HCM (oHCM). This review offers an integrated and up-to-date synthesis of the cardiac myosin inhibitor class, with a focus on mavacamten, aficamten, and the broader landscape of emerging agents. It also highlights recent clinical trial outcomes, pharmacokinetic and pharmacogenetic considerations, and potential future directions in therapy. Furthermore, we incorporate the most recent data up to May 2025, including late-breaking trial results and real-world safety findings, aiming to provide clinicians with a practical and comprehensive perspective on this evolving drug class. A narrative review was conducted by systematically searching PubMed, Scopus, Google Scholar, and ClinicalTrials.gov for English-language articles and trials published between January 2016 and May 2025. Keywords included “cardiac myosin inhibitor”, mavacamten”, “aficamten”, “MYK-224”, and “hypertrophic cardiomyopathy.” Inclusion criteria encompassed clinical trials and comprehensive reviews specifically addressing CMIs in cardiac applications. CMIs such as mavacamten and aficamten have demonstrated significant clinical benefits in reducing LVOT gradients, improving exercise capacity, and alleviating symptoms in patients with oHCM. Mavacamten is currently approved for clinical use, while aficamten is in advanced regulatory review. Comparative data suggest potential advantages of aficamten in the onset of action, pharmacokinetic profile, and tolerability. Emerging evidence supports the exploration of CMIs in pediatric populations, heart failure with preserved ejection fraction (HFpEF), and non-obstructive HCM (nHCM), although results are still preliminary. Cardiac myosin inhibitors offer a novel, pathophysiology-targeted approach to managing oHCM. While mavacamten has established efficacy, next-generation agents like aficamten may offer improved safety and versatility. Further long-term studies are needed to clarify their role across broader patient populations. Full article

The phosphorylation of Rab10 (pT73-Rab10) by LRRK2 promotes the establishment of epithelial cell polarity by controlling the trafficking to the primary cilia membrane of cilia-resident proteins and signaling proteins. Previous studies have identified a site in the globular tail domain of MYO5A that specifically binds to only the phosphorylated form of Rab10. In this work, we have demonstrated that pT73-Rab10 does not associate with the globular tail of MYO5B. We have mapped the putative binding site to a required three amino acids (MEN, 1473–1475) in the MYO5A globular tail domain that are not found in the MYO5B globular tail. Substitution of the MEN amino acid sequence found in MYO5A into the paralogous position in the MYO5B globular tail conferred the ability to associate with pT73-Rab10. The results demonstrate that the interactors with MYO5A and MYO5B are not completely overlapping and that the interaction of pT73-Rab10 is specific to the MYO5A globular tail domain. Full article

In epithelial cells, nonmuscle myosin-2B (NM2B) shows a cortical localization and is tethered to tight junctions (TJs) and adherens junctions (AJs) by the junctional adaptor proteins cingulin and paracingulin. MDCK cells knock-out (KO) for cingulin show decreased apical membrane cortex stiffness and decreased TJ membrane tortuosity, and the rescue of these phenotypes requires the myosin-binding region of cingulin. Here, we investigated whether NM2B contributes to these phenotypes independently of cingulin by generating and characterizing clonal lines of MDCK cells KO for NM2B. The loss of NM2B resulted in decreased stiffness and increased fluidity of the apical cortex and reduced accumulation of E-cadherin and phalloidin-labeled actin filaments at junctions but had no significant effect on TJ membrane tortuosity. Fluorescence recovery after photobleaching (FRAP) showed that the KO of NM2B increased the dynamics of the TJ scaffold protein ZO-1, correlating with decreased ZO-1 accumulation at TJs. Finally, the KO of NM2B increased cell size in cells grown both in 2D and 3D but did not alter lumen morphogenesis of cysts. These results extend our understanding of the functions of NM2B by describing its role in the regulation of the mechanical properties of the apical membrane cortex and cell size and validate our model about the role of cingulin–NM2B interaction in the regulation of ZO-1 dynamics. Full article

Rhabdomyosarcoma (RMS), the most common pediatric soft tissue sarcoma, comprises embryonal (ERMS) and alveolar (ARMS) subtypes with distinct histopathological features, clinical outcomes, and therapeutic responses. To better characterize their molecular distinctions, we performed untargeted plasma proteomics and metabolomics profiling in children with ERMS (n = 18), ARMS (n = 17), and matched healthy controls (n = 18). Differential expression, functional enrichment (GO, KEGG, RaMP-DB), co-expression network analysis (WGCNA/WMCNA), and multi-omics integration (DIABLO, MOFA) revealed distinct molecular signatures for each subtype. ARMS displayed elevated oncogenic and stemness-associated proteins (e.g., cyclin E1, FAP, myotrophin) and metabolites involved in lipid transport, fatty acid metabolism, and polyamine biosynthesis. In contrast, ERMS was enriched in immune-related and myogenic proteins (e.g., myosin-9, SAA2, S100A11) and metabolites linked to glutamate/glycine metabolism and redox homeostasis. Pathway analyses highlighted subtype-specific activation of PI3K-Akt and Hippo signaling in ARMS and immune and coagulation pathways in ERMS. Additionally, the proteomics and metabolomics datasets showed association with clinical parameters, including disease stage, lymph node involvement, and age, demonstrating clear molecular discrimination consistent with clinical observation. Co-expression networks and integrative analyses further reinforced these distinctions, uncovering coordinated protein–metabolite modules. Our findings reveal novel, subtype-specific molecular programs in RMS and propose candidate biomarkers and pathways that may guide precision diagnostics and therapeutic targeting in pediatric sarcomas. Full article

Protein association and aggregation are fundamental processes that play critical roles in a variety of biological phenomena from cell signaling to the development of incurable diseases, including amyloidoses. Understanding the basic biophysical principles governing protein aggregation processes is of crucial importance for developing treatment strategies for diseases associated with protein aggregation, including sarcopenia, as well as for the treatment of pathological processes associated with the disruption of functional protein complexes. This work, using a set of methods such as atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction, as well as bioinformatics analysis, investigated the structures of complexes formed by titin and myosin-binding protein C (MyBP-C). TEM revealed the formation of morphologically ordered aggregates in the form of beads during co-incubation of titin and MyBP-C under close-to-physiological conditions (175 mM KCl, pH 7.0). AFM showed the formation of a relatively homogeneous film with local areas of relief change. Fluorimetry with thioflavin T, as well as FTIR spectroscopy, revealed signs of an amyloid-like structure, including a signal in the cross-β region. X-ray diffraction showed the presence of a cross-β structure characteristic of amyloid aggregates. Such structural features were not observed in the control samples of the investigated proteins separately. In sarcomeres, these proteins are associated with each other, and this interaction plays a partial role in the formation of a strong sarcomeric cytoskeleton. We found that under physiological ionic-strength conditions titin and MyBP-C form complexes in which an amyloid-like structure is present. The possible functional significance of amyloid-like aggregation of these proteins in muscle cells in vivo is discussed. Full article

Pangasius (Pangasianodon hypophthalmus) minced muscle with 1 and 2% salt was treated with different high-pressure processing and thermal methods, including conventional heat-induced gels (HIGs), high-pressure processing (HPP) prior to cooking (PC), HPP prior to setting (PS), and setting prior to HPP (SP), to evaluate for their effects on the selected physicochemical properties. The results showed that the PC treatment produced gels with a significantly higher gel strength (496.72–501.26 N·mm), hardness (9.62–10.14 N), and water-holding capacity (87.79–89.74%) compared to the HIG treatment, which showed a gel strength of 391.24 N·mm, a hardness of 7.36 N, and a water-holding capacity of 77.98%. PC gels also exhibited the typical microstructure of pressure-induced gels, with a denser and homogeneous microstructure compared to the rough and loosely connected structure of HIGs. In contrast, SP treatment exhibited the poorest gel quality in all parameters, with gel strength ranging from 319.79 to 338.34 N·mm, hardness from 5.87 to 6.31 N, and WHC from 71.91 to 73.72%. Meanwhile, the PS treatment showed a comparable gel quality to HIGs. SDS-PAGE analysis revealed protein degradation and aggregation in HPP-treated samples, with a decrease in the intensity of myosin heavy chains and actin bands. Fourier-transform infrared spectroscopy (FTIR) analysis showed minor shifts in protein secondary structures, with the PC treatment showing a significant increase in α-helices (28.09 ± 0.51%) and a decrease in random coil content (6.69 ± 0.92%) compared to α-helices (23.61 ± 0.83) and random coil structures (9.47 ± 1.48) in HIGs (p < 0.05). Only the PC treatment resulted in a significant reduction in total plate count (TPC) (1.51–1.58 log CFU/g) compared to 2.33 ± 0.33 log CFU/g in the HIG treatment. These findings suggest that HPP should be applied prior to thermal treatments (cooking or setting) to achieve an improved gel quality in reduced-salt pangasius products. Full article

(1) Background: The sophisticated function of the aortic root relies on the coordinated movement of its constituent components. This study examines the extracellular components of the interleaflet triangles (ILTs) and characterises the cells that are present within this region of the aortic root. (2) Methods: A total of 10 human aortic valves and 6 porcine aortic valves were processed for immunohistochemical staining, scanning, and transmission electron microscopy. (3) Results: The three ILTs differed in size and macroscopic appearance. Each triangle comprised up to five distinct layers of tissue: an innermost endothelial layer, an inner elastin-rich layer, a thicker outer layer comprising densely packed layers of collagen and glycosaminoglycans, and an outer layer of intermingled myocardial and adipose tissue. A band of cells near the luminal surfaces of all ILTs expressed smooth muscle cell α-actin with variable expression of smooth muscle myosin heavy chain. In all the ILTs, there was evidence of neurofilament staining, indicating the presence of nerve fibres. (4) Conclusions: Each ILT is unique in its structure and organisation, with differing amounts of elastin and collagen, as well as myocardial, adipose, and fibrous content. The ILTs contain multiple cell types in varying abundance. Functional studies are required to determine the role of the different cells and their organisation in contributing to the sophisticated, dynamic behaviour of the aortic root. Full article

Proteomics combined with peptidomics approaches were used to analyze the protein degradation and the release pattern of umami peptides in stewed chicken. The results showed that a total of 422 proteins were identified, of which 273 proteins consistently existed in samples stewed for 0–5 h. Myosin heavy chain exhibited the highest abundance (26.29–30.26%) throughout the stewing process. The proportion of proteins under 20 kDa increased progressively with the duration of stewing and reached 61% at 4–5 h of stewing. A total of 8018 peptides were detected in the soup samples, and 2323 umami peptides were identified using the prediction platforms iUmami-SCM, UMPred-FRL, Umami_YYDS, and TastePertides-DM. Umami peptides derived from titin (accession number A0A8V0ZZ81) were determined to be the most abundant, accounting for 24% of the total umami peptides, and Val534 and Lys33639 were the key N-terminal and C-terminal amino acids of these umami peptides. Abundance analysis showed that the umami peptides KK16 and SK18 ranked among the top 5 in the samples stewed for 0–5 h, and they were most abundant in the 3 h stewed samples. The results obtained will provide data support for promoting the industrialization of high-quality chicken soup products. Full article

Sudden cardiac death (SCD) is a major public health concern, being a leading cause of death worldwide. SCD is particularly alarming for individuals with apparently good health, as it often occurs without preceding warning signs. Unfortunately, traditional autopsy methods frequently fail to identify the precise cause of death in these cases, highlighting the need for advanced techniques to elucidate underlying mechanisms. Recent advances in molecular biology over the past few years, particularly in proteomics, transcriptomics, and metabolomics techniques, have led to an expanded understanding of gene expression, protein activity, and metabolic changes, offering valuable insights into fatal cardiac events. Combining multi-omics methods with bioinformatics and machine learning algorithms significantly enhances our ability to uncover the processes behind lethal cardiac dysfunctions by identifying new useful biomarkers (like cardiac myosin-binding protein C, acylcarnitines, or microRNAs) to reveal molecular pathways linked to SCD. This narrative review summarizes the role of multi-omics approaches in forensic diagnosis by exploring current applications in unexplained cases and the benefits of integrating merged techniques in otherwise negative autopsies. We also discuss the potential for developing personalized and preventive forensic medicine, the technical limitations of currently available methods, and the ethical considerations arising from these advancements. Full article

Chronic ethanol use can lead to alcoholic cardiomyopathy (ACM), while the impact on the molecular and cellular aspects of the myocardium is unclear. Accordingly, male Sprague-Dawley rats were exposed to an ethanol-containing diet for 16 weeks and compared with a control group that was fed an isocaloric diet. Histological measurements from H&E slides revealed no significant differences in cell size. A proteomic approach revealed that alcohol exposure leads to enhanced mitochondrial lipid metabolism, and electron microscopy revealed impairments in mitochondrial morphology/density. Cardiac myosin purified from the hearts of ethanol-exposed animals demonstrated a 15% reduction in high-salt ATPase activity, with no significant changes in the in vitro motility and low-salt ATPase or formation of the super-relaxed (SRX) state. A protein carbonyl assay indicated a 20% increase in carbonyl incorporation, suggesting that alcohol may impact cardiac myosin through oxidative stress mechanisms. In vitro oxidation of healthy cardiac myosin revealed a dramatic decline in ATPase activity and in vitro motility, demonstrating a link between myosin protein oxidation and myosin mechanochemistry. Collectively, this study suggests alcohol-induced metabolic remodeling may be the initial insult that eventually leads to defects in the contractile machinery in the myocardium of ACM hearts. Full article

Polarized fluorescence microscopy of “ghost” muscle fibers, containing fluorescently labeled F-actin, tropomyosin, and myosin, has provided new insights into the molecular mechanisms underlying muscle contraction. At low Ca²⁺, the troponin-induced overtwisting of the actin filament alters the configuration of myosin binding sites, preventing actin–myosin interactions. As Ca²⁺ levels rise, the actin filament undergoes untwisting, while tropomyosin becomes overtwisted, facilitating the binding of myosin to actin. In the weakly bound state, myosin heads greatly increase both the internal twist and the bending stiffness of actin filaments, accompanied by the untwisting of tropomyosin. Following phosphate (Pi) release, myosin induces the untwisting of overtwisted actin filaments, driving thin-filament sliding relative to the thick filament during force generation. Point mutations in tropomyosin significantly alter the ability of actin and tropomyosin filaments to respond to Pi release, with coordinated changes in twist and bending stiffness. These structural effects correlate with changes in actomyosin ATPase activity. Together, these findings support a model in which dynamic filament twisting is involved in the molecular mechanisms of muscle contraction together with the active working stroke in the myosin motor, and suggest that impairment of this ability may cause contractile dysfunction. Full article

Muscle aging and atrophy in the elderly are closely associated with increased oxidative stress in muscle tissue. Bioactive peptides derived from protein hydrolysates have emerged as promising functional ingredients for alleviating sarcopenia due to their antioxidant properties and enrichment in essential amino acids. In a preliminary screening, mackerel protein hydrolysate (MPH) showed notable protective effects in a myotube atrophy model. This study evaluated the anti-atrophic potential of MPHs produced using different enzymes in H₂O₂-treated C2C12 myotubes. Among five hydrolysates, the alcalase-derived hydrolysate (MHA) demonstrated the most potent effects in maintaining myotube diameter, restoring myosin heavy chain (MYH) expression, and downregulating the atrophy-related genes MAFbx and MuRF1. Mechanistically, MHA activated the Akt/FoxO signaling pathway and inhibited NF-κB activation, thereby reducing muscle protein degradation. Additionally, MHA significantly lowered intracellular ROS levels and showed strong direct antioxidant activity. Amino acid and molecular weight profiling revealed high levels of essential amino acids and low-molecular-weight peptides, suggesting a synergistic contribution to its bioactivity. These findings suggest that MHA is a promising food-derived functional material with anti-atrophic and antioxidant properties and may be useful in preventing or managing age-related muscle loss such as sarcopenia, warranting further preclinical validation. Full article

Fermented feed has considerable potential as a high-quality protein source in animal production. This research aimed to examine the effects of a low-protein (LP) diet, supplemented with fermented feed, on the meat quality and intestinal health of growing–fattening pigs. The pigs were randomly divided into three groups, and a total of 72 growing–fattening pigs were subjected to the experiment. They were fed the control (CON) diet, LP diet, and LP diet supplemented with fermented rapeseed meals and fermented distiller’s grains (FLP), respectively. The results indicated that the FLP diet altered the structure of the intestinal microbiota and regulated the composition of unsaturated fatty acids in the longissimus dorsi. Furthermore, the FLP diet upregulated the expression of genes associated with myosin heavy chain isoforms (p < 0.05) and modified the content of short-chain fatty acids in the intestines (p < 0.05). In summary, the addition of fermented distiller’s grains (FDGs) and fermented rapeseed meals (FRMs) to the LP diet enhanced fatty acid metabolism and intestinal barrier function in growing–fattening pigs. Full article