Search Results (318)

Caffeine (CAF) is a widely consumed psychostimulant known to modulate adenosine receptors and neurotransmitter systems, although its effects in invertebrates remain poorly understood. Environmentally relevant concentrations (5, 30, and 50 µg/L) are associated with altered behavior, including locomotion, exploration, and feeding, in the freshwater gastropod Physella acuta. This study examined molecular responses underlying these effects. Adult snails were exposed to CAF for 24 h and 7 days. Gene expression related to the nervous system and stress pathways was analyzed by RT-PCR, including A1AR, ADORA2B, AChE, GLRA2, DRD2, RYR, HSD11β, HSP70, SLC6A2, and SLC6A1. After 24 h, exposure to 50 µg/L CAF altered A1AR expression and caused downregulation of AChE, GLRA2, and DRD2, associated with observed behavioral changes. A1AR upregulation may indicate compensatory adjustment in adenosine signaling. After 7 days, A1AR remained upregulated, while genes linked to inhibitory neurotransmission showed partial recovery. Increased expression of genes involved in dopamine regulation and steroid metabolism suggested physiological adaptation. Overall, CAF induced dose- and time-dependent molecular responses in P. acuta, linking neurochemical disruption with behavioral changes and highlighting its ecological risk as an emerging freshwater contaminant. Full article

How do ryanodine receptors (RyRs) open simultaneously to trigger the contraction of whole myofibrils within a large skeletal muscle cell? One possible answer is the uniformity of mechanosensitive RyRs, which is mechanically forced by the neighboring environment, including proteins. Here, we review papers addressing this proposed “mechanical sarcoplasmic reticulum (SR) paradigm”. Crystals of the molecular complexes comprising RyR and L-type voltage-gated Ca²⁺ channels were observed at the T-tubule/SR junction in situ using cryo-electron tomography. Observations of the SR vesicles isolated from rabbit and scallop cross-striated muscles using negative staining and transmission electron microscope raised a hypothesis of dynamic rearrangement of the Ca²⁺-ATPase (ATPase) molecules in response to cytoplasmic calcium concentration, as follows: (i) At a low calcium concentration where the ratio of operating ATPase molecules to the total molecules is at a submaximal level, the ATPase molecules form, at least in part, their cylindrical crystals in the SR membrane with the help of ATP; this results in the elongation of the SR vesicles. (ii) High concentrations of calcium, at which the ratio of operating ATPase molecules is maximal, reversibly collapse the ATPase crystals to transform the elongated vesicles into round forms comprising tightly attached crystal patches. These data further lead to the idea that the reversible growth of cylindrical ATPase crystals provides a dynamic crystalline network, which acts as an “SR membrane-endoskeletal motor” to manipulate the SR movement. The possibility of interactions between ATPase crystals and neighboring RyR crystals is also discussed. Full article

Type-1 ryanodine receptor (RyR1) is essential for skeletal muscle contraction. This Ca²⁺ release channel is expressed in cardiac myocytes; however, its function remains elusive. Cardiac-specific RyR1 overexpression (OE) mice were generated under the cardiac-specific Myh6 promoter. Cardiac hypertrophy (CH), cardiac functions, and mechanistic changes in RyR1 OE and control (wildtype, WT) mice were assessed using hematoxylin and eosin staining, echocardiography, electrocardiogram, quantitative RT-PCR, Western blotting, [³H]-ryanodine binding assay, confocal microscope, ROS dye Amplex Red and 2′,7′-dichlorofluorescein diacetate. RyR1 OE mice had increased whole heart, left ventricular weight, and left ventricular wall thickness, but decreased cardiac output and stroke volume, thereby presenting CH and heart failure (HF). CH markers like ANF, BNF, and aSKA mRNAs were increased in RyR1 OE heart. RyR1, but not RyR2 or RyR3, expression was increased in the RyR1 OE mouse heart. Similar results were found in mice with TAC-induced CH. RyR1, but not RyR2 mRNA, was increased in cardiac muscle from dogs and humans with CH and/or HF. Maximum [³H]-ryanodine binding was increased, whereas the binding dissociation constant decreased in left ventricular cardiomyocytes from RyR1 OE mice. RyR2-dependent Ca²⁺ sparks were increased, which was blocked by riluzole, a small molecule known to inhibit RyR2. Consistently, ROS was remarkably increased in RyR1 OE cardiac cells. We first generated cardiac-specific RyR1 OE mice; these mice had CH, HF, and increased RyR1 expression with no RyR2 or RyR3 alteration. Similar changes were observed in mice, dogs, and humans with CH and HF. Increased mitochondrial ROS-dependent RyR2 Ca²⁺ release was essential for RyR1-induced CH and HF. Full article

Alzheimer’s disease (AD) is the most common form of dementia, characterized by the progressive accumulation of amyloid β (Aβ) plaques and neurofibrillary tangles of tau protein in and around neurons. However, these markers appear relatively late in the disease, and their direct causality is incompatible with clinical observations. Extensive data suggest that dysregulation of Ca²⁺ signaling is an early event in the pathogenesis of AD. In familial AD (FAD), mutations in presenilin are shown to alter Ca²⁺ homeostasis by affecting the gating properties and/or the expression levels of inositol 1,4,5-trisphosphate (IP₃) receptors (IP₃Rs) and ryanodine receptor (RyRs)—the main channels responsible for Ca²⁺ release from the endoplasmic reticulum (ER). Thus, understanding the mechanism through which these channels disrupt Ca²⁺ homeostasis at different spatiotemporal scales is crucial to determining their role in AD. Here, we use computational modeling to investigate how the gating kinetics of single IP₃R in FAD-affected cells differ from those in wildtype (WT) cells and how these differences translate to impaired Ca²⁺ signaling at subcellular and whole-cell levels. Our detailed analysis reveals a significantly lower threshold for Ca²⁺ oscillations at the whole-cell level in terms of agonist concentration, with higher frequency and amplitudes in FAD-affected cells. These results shed new light on the observed Ca²⁺ hyperactivity in the pre-clinical stage of AD, reporting high-frequency Ca²⁺ oscillations in neurons. Full article

Pediatric-onset neuromuscular diseases (NMDs) represent a clinically and genetically heterogeneous group of rare disorders, often posing significant diagnostic challenges due to overlapping phenotypes. Next-generation sequencing (NGS), particularly whole-exome sequencing (WES), has transformed the diagnostic landscape; however, its clinical utility varies across phenotypic subgroups. We conducted a combined retrospective–prospective cohort study that included 100 pediatric patients with suspected neuromuscular disorders evaluated at a tertiary referral center between 2015 and 2025. Patients were stratified into seven clinically defined diagnostic categories prior to genetic testing. NGS-based diagnostics (primarily WES) were performed following initial clinical and targeted evaluations. Diagnostic yield and predictors of a positive genetic result were analyzed using univariate and multivariable statistical approaches. A molecular diagnosis was established in 71% of patients, including 64% with pathogenic/likely pathogenic variants and 7% with clinically consistent variants of uncertain significance. Diagnostic yield varied significantly across disease categories (p < 0.001), reaching near-complete rates in well-defined phenotypes such as congenital myasthenic syndromes, neuropathies, and metabolic myopathies, while markedly lower yield was observed in unclassified cases (38.2%). Multivariable logistic regression identified disease group as the only independent predictor of diagnostic success (B = −0.436, p = 0.001). Frequently implicated genes included DMD, RYR1, and LAMA2, reflecting a predominance of structural and excitation–contraction coupling defects. NGS demonstrates high diagnostic utility in pediatric neuromuscular disorders, particularly when applied in a phenotype-driven framework. Diagnostic performance is strongly influenced by the degree of clinical definition prior to testing, highlighting the continued importance of expert phenotyping in the genomic era. Full article

Objective: This study aims to investigate the protective effect of Shengmai San (SMS) against high-glucose (HG)-induced injury in neonatal rat ventricular myocytes (NRVMs) and to elucidate the underlying pharmacological molecular mechanisms. We hypothesize that SMS ameliorates HG-induced calcium homeostasis imbalance in NRVMs by improving mitochondrial energy metabolism disorder, and this protective effect is associated with the downregulation of oxidized and phosphorylated CaMKII expression to inhibit CaMKII signaling pathway overactivation. Herein, we verify this hypothesis by assessing mitochondrial function, calcium transients, sarcoplasmic reticulum (SR) calcium handling and CaMKII phosphorylation levels in NRVMs. Methods: First, ultra-high performance liquid chromatography–high resolution mass spectrometry was used to identify the chemical components of SMS to clarify its material basis. Primary NRVMs were then cultured under low-glucose (LG) or HG conditions, with 2% SMS-medicated serum (SMS-MS) as the experimental intervention, and NAC (ROS scavenger) and KN93 (CaMKII inhibitor) as positive controls. Following intervention, we sequentially detected key indicators corresponding to the proposed pathological pathway: intracellular reactive oxygen species (ROS) levels (oxidative stress), mitochondrial ROS, mitochondrial function indices including oxygen consumption rate (OCR) (energy metabolism), calcium transients and diastolic intracellular free calcium concentration (global calcium homeostasis), sarcoplasmic reticulum (SR) calcium leak (calcium handling disorder), and, finally, the phosphorylation, oxidation levels of CaMKII and RyR2 phosphorylation (Ser2814) (p-RyR2) (key regulatory pathway) via Western blot to systematically elucidate the mechanistic link between SMS intervention and HG-induced NRVM injury. Results: Quantitative analysis revealed that high-glucose (HG) induction significantly reduced calcium transient amplitude and prolonged the decay time constant (tau) in NRVMs at 72 h (p < 0.01 vs. LG), with these parameters normalizing by 120 h—an effect indicative of a compensatory adaptive response. The 2%SMS-MS markedly ameliorated HG-induced calcium transient abnormalities at 72 h (p < 0.01 vs. HG). Additionally, 2%SMS-MS significantly enhanced mitochondrial basal oxygen consumption rate, spare respiratory capacity, ATP production, and maximal respiration in HG-exposed NRVMs (p < 0.01 vs. HG). SMS also significantly reduced intracellular reactive oxygen species (ROS) levels (p < 0.01 vs. HG), mitochondrial ROS levels (p < 0.01 vs. HG), diastolic intracellular free calcium concentration (p < 0.01 vs. HG), and SR calcium leak (p < 0.05 vs. HG). Western blot analysis revealed that 2%SMS-MS intervention effectively downregulated the expression of oxidized CaMKII (Ox-CaMKII) (p < 0.01 vs. HG), phosphorylated CaMKII (p-CaMKII) (p < 0.01 vs. HG), and RyR2 phosphorylation (Ser2814) (p < 0.05 vs. HG), which may be the potential mechanism in maintaining calcium homeostasis in HG-induced NRVMs. Conclusions: This study suggests that SMS enhances mitochondrial energy metabolism and exerts a protective effect against high-glucose-induced calcium homeostasis imbalance in NRVMs, which supports our proposed hypothesis. Its potential mechanism indicates that the protective effects of SMS are associated with its ability to downregulate the expression of oxidized and phosphorylated CaMKII. These findings highlight SMS as a potential therapeutic candidate for alleviating HG-related myocardial injury and provide evidence for its application in the prevention of early diabetic cardiomyopathy. Full article

Tubular aggregate myopathy (TAM) is a rare inherited muscle disorder characterized by the abnormal accumulation of tubular aggregates (TAs) within skeletal muscle fibers. These aggregates, composed of compacted sarcoplasmic reticulum (SR) tubules, are strongly linked to disturbances in calcium (Ca²⁺) homeostasis. Clinically, TAM manifests with slowly progressive proximal muscle weakness, exercise intolerance, cramps, and myalgia, frequently beginning in childhood and often present with elevated serum creatine kinase levels. These symptoms can also be associated with some additional disorders, such as thrombocytopathy, miosis, hypocalcemia, hyposplenism, and ichthyosis, thereby resulting in a clinical picture that overlaps with symptoms of Stormorken (STRMK) syndrome. Considerable heterogeneity exists in age of onset, severity, and extra-muscular involvement, suggesting that TAM and STRMK represent a continuum rather than distinct entities. Histopathological hallmarks include TAs staining positive for SR proteins and displaying a honeycomb-like ultrastructure, consistent with aberrant SR remodeling. Mutations in genes encoding key regulators of store-operated calcium entry (SOCE), including STIM1 and ORAI1 have been identified as major contributors to TAM and its broader clinical spectrum, which encompasses STRMK syndrome, whereas mutations in CASQ1 and RYR1, have been described in only a minority of patients. Despite advances in delineating the genetic and molecular basis of TAM, key questions remain regarding the mechanisms that drive TAs formation and translate Ca²⁺ dysregulation into muscle dysfunction and multisystem disease. Understanding the molecular mechanisms underlying TAM and STRMK syndrome is crucial for developing targeted therapies. Moreover, further research is needed to elucidate additional pathways involved in disease progression and to refine genotype–phenotype correlations. This review summarizes current knowledge on the genetics, pathophysiology, clinical features, and diagnostic hallmarks of TAM, with particular emphasis on the role of Ca²⁺ homeostasis. Full article

Red yeast rice (RYR), a traditional fermented product obtained via rice fermentation with Monascus purpureus, has a millennia-long history of culinary and medicinal use in East Asia and has gained global attention as a prominent functional food ingredient for its well-recognized cholesterol-lowering properties. This review is driven by one core question: How can the dual challenges of standardizing key bioactive constituents, particularly monacolin K (MK), while eliminating the mycotoxin citrinin be addressed through biotechnological and analytical advances? This narrative review consolidates the latest research progress on RYR-derived bioactive compounds, with a specific focus on their production optimization, multifaceted health-promoting potentials, safety regulation, and application prospects in health food development. We elaborate on key advances in fermentation biotechnology and strain engineering for enhancing the yield of the core lipid-lowering component MK while eliminating the nephrotoxic mycotoxin citrinin, and comprehensively summarize the synergistic bioactivities of RYR metabolites beyond MK. The current applications of RYR in functional foods, dietary supplements, and traditional fermented products are detailed, alongside a comparison of the divergent regulatory frameworks for RYR across major global markets. Finally, we identify critical bottlenecks restricting RYR industrialization, including extreme inter-product heterogeneity and global regulatory fragmentation, and propose evidence-based future research directions to facilitate the development of safe, standardized, and effective RYR-based health foods. Full article

Cyantraniliprole, a second-generation diamide insecticide, exhibits broad-spectrum efficacy against numerous insect pests due to its selective activation of insect ryanodine receptors (RyRs). This activation triggers uncontrolled calcium release from the sarcoplasmic reticulum, resulting in sustained muscle contraction, paralysis, and ultimately death. Its unique mode of action, which is different from that of organophosphates, carbamates, pyrethroids, and neonicotinoids, helps minimize cross-resistance, making it a valuable component of integrated pest management (IPM). However, continuous field use has led to the development of resistance, primarily mediated by target-site mutations within the RyR transmembrane domain (e.g., G4946E, I4743M, and I4790K) and by enhanced metabolic detoxification via cytochrome P450 monooxygenases, carboxylesterases, and glutathione S-transferases. These mechanisms often confer cross-resistance to other diamide insecticides, thereby complicating resistance management. Moreover, sublethal exposures can disrupt insect growth, development, and reproduction, potentially accelerating resistance evolution. In addition, cyantraniliprole poses ecological risks due to its toxicity to non-target organisms such as aquatic species, including zebrafish and water fleas, pollinators such as honeybees, and soil fauna, as well as the environmental persistence of its major metabolite, J9Z38. This review comprehensively integrated current knowledge on the molecular mechanisms of action, genetic and metabolic bases of resistance, sublethal effects, and ecotoxicological impacts of cyantraniliprole, along with its environmental fate, plant uptake and translocation, and residue dynamics in agricultural systems. Finally, we discuss potential risk-mitigation strategies, including formulation optimization, application-method improvements, and resistance monitoring. Overall, this review aims to provide a comprehensive scientific foundation for the sustainable use, resistance management, and regulatory assessment of this widely used insecticide. Full article

Cardiac Ca²⁺ handling is critical for excitation–contraction coupling (ECC), with the ryanodine receptor type 2 (RyR2) serving as the key sarcoplasmic reticulum (SR) Ca²⁺ release channel in cardiomyocytes. The dysfunction of RyR2 is linked to fatal cardiac arrhythmias, including heart failure (HF) and catecholaminergic polymorphic ventricular tachycardia (CPVT). This review aims to elucidate the structural basis of RyR2, its core role in cardiac ECC and Ca²⁺ homeostasis, and the regulatory mechanisms of key modulators on its activity. By integrating recent high-resolution cryo-EM structural analyses with molecular and cellular studies on RyR2 regulation, as well as clinical evidence of RyR2 mutations in arrhythmogenic heart diseases, we provide a comprehensive overview of the field. Cryo-EM has unraveled RyR2’s gating mechanisms, ligand-binding sites, and structural features. Functionally, RyR2 mediates calcium-induced calcium release (CICR) and maintains Ca²⁺ homeostasis through coordination with SERCA2a and NCX. Key modulators (CaM, FKBP12.6, and PKA/CaMKII) and disease-linked mutations regulate RyR2 activity through distinct pathways, with defective RyR2 leading to store-overload-induced Ca²⁺ release (SOICR) and arrhythmias. Furthermore, reactive oxygen species (ROS) can induce RyR2 oxidation, establishing a pathological Ca²⁺ leak-ROS cycle in heart disease. In conclusion, RyR2 is a pivotal sensor of myocardial function, with its structural and regulatory mechanisms now well-characterized by recent studies. However, the effects of numerous RyR2 mutations remain unclear, and deeper mechanistic insights will lay a key foundation for developing novel therapies against RyR2-related cardiac diseases. Full article

H3K4me3, a well-established histone modification associated with active promoters, plays a critical role in orchestrating gene expression programs that govern mammary gland development and lactation. In this study, we present the first comprehensive epigenomic profiling of H3K4me3 modifications during mammary gland development in Yili horses using Cleavage Under Targets and Tagmentation (CUT&Tag) and RNA sequencing. Mammary gland tissues were collected from two developmental stages—early lactation and peak lactation. A total of 393 differentially expressed genes (DEGs) were identified between two groups, among which 72 DEGs (54 upregulated H3K4me3 targets and 18 downregulated targets) were directly regulated by H3K4me3. KEGG enrichment analyses revealed that these DEGs were involved in ECM–receptor interaction, focal adhesion, the PI3K-Akt signaling pathway, and the calcium signaling pathway. In these pathways, five genes were identified as potential regulators of mammary gland development. Among these, PTGES, COL1A1, PDGFRB, and RYR1 exhibited consistent upregulation at both the transcriptomic and chromatin levels, whereas PRKAG3 showed significant downregulation. These findings offer novel insights into the epigenetic regulation of lactation in horses and lay a theoretical foundation for improving milk production traits through targeted molecular breeding strategies. Full article

Purpose: Tumor location influences survival in bladder cancer, potentially due to genetic heterogeneity driven by distinct embryological origins and structural compositions. We investigate location-specific somatic gene alterations (GAs) and their potential clinical implications in muscle-invasive bladder cancer (MIBC). Methods: We explored the role of the intra-bladder tumor location in determining survival and underlying genetic alterations in MIBC patients using multiple large independent databases. We analyzed the tumor location’s impact on survival using the Surveillance, Epidemiology, and End Results (SEER) database and validated these findings using cBioPortal (CBP), which also contains gene sequencing data, enabling a comparison of GA frequency by tumor location. We investigated GA combinations to identify potential synthetic lethal (SL) combinations and co-occurrence signatures for survival prediction. Using the ROC Plotter database, we explored how significantly altered genes affect the response to immune checkpoint inhibitors (ICI). Results: An analysis of 6712 SEER and 570 CBP patients revealed significant (p < 0.001) differences in overall survival stratified by tumor location, with trigone tumors showing the worst survival. Genomic analysis identified 35 genes with location-specific alteration frequencies. Three of these genes, CDKN2A, SPTAN1, and BIRC6, were significantly predictive of ICI response, and three genes were uniquely associated with a specific location: BPTF (anterior wall), RYR1, and OBSCN (dome). Furthermore, we identified 349 SL pairs from the 35 significantly altered genes, and a co-occurrence analysis revealed two novel gene pairs associated with improved survival. Conclusions: Intra-bladder tumor location determines survival and distinct genetic profiles in MIBC. These location-specific alterations predict ICI response and identify novel synthetic lethal targets, guiding precision oncology. Full article

Red yeast rice (RYR) food supplements are widely used for cholesterol management owing to their content of monacolin K (MK), which, in its lactone form, is chemically identical to the prescription statin lovastatin. Despite their popularity, RYR products raise significant quality and safety concerns related to pronounced variability in MK content, frequent labeling non-compliance, contaminations with undeclared pharmaceutical statins, etc. The analytical differentiation between naturally produced MK and added synthetic lovastatin remains particularly challenging due to their identical chemical structures. This review provides a comprehensive overview of the chemical composition of RYR, with emphasis on monacolins, pigments, and relevant secondary metabolites, and critically summarizes current regulatory, safety, and quality issues associated with RYR-based food supplements. Furthermore, a practical, multi-level analytical strategy for product authentication is proposed. The approach integrates targeted quantification of MK and accompanying monacolins, identification of characteristic Monascus pigments as authenticity markers, gas chromatography–mass spectrometry for the detection of undeclared statins and other non-declared constituents, and proton nuclear magnetic resonance for global compositional fingerprinting. By combining complementary targeted and non-targeted techniques, this workflow enables more reliable authentication, detection of adulteration, and comprehensive quality assessment. The implementation of standardized analytical protocols is essential to improve transparency and enhance consumer safety in the rapidly expanding RYR supplement market. Full article

To address the limited functional diversity of traditional kombucha, this study utilized red yeast rice (RYR) as an alternative substrate and prepared three samples: black tea kombucha (KBT), black tea-red yeast rice mixed kombucha (KBL, at a 1:1 ratio), and red yeast rice kombucha (KRY). After 9 days of fermentation, KRY exhibited the lowest pH, the highest total acidity, and notable sugar metabolic activity. It exhibited in vitro inhibition rates of 82.8%, 78.2%, 70.3%, and 76.9% against cholesterol esterase, pancreatic lipase, α-glucosidase, and α-amylase, respectively, indicating potential hypoglycemic and hypolipidemic activities. In contrast, KBT maintained the strongest antioxidant capacity, with scavenging rates exceeding 90% against both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS). A total of 72 volatile flavor compounds (VFCs) were identified, with 7 key compounds enriched in KRY, which enhanced its sensory acceptance and received the highest scores in color, clarity, and aroma. Microbial community analysis revealed the post-fermentation dominance of Komagataeibacter, Acetobacter, and Saccharomyces, which correlated positively with key VFCs. These findings indicate that RYR as a substrate enhances functional microbial growth, sugar metabolism, organic acid production, flavor enrichment, and in vitro inhibitory activity of enzymes associated with hypoglycemic and hypolipidemic effects. Full article

Gestational diabetes mellitus (GDM) develops silently during early pregnancy, yet its earliest circulating molecular signatures remain poorly defined. In this exploratory biomarker study, we characterized first-trimester circulating microRNA (miRNAs) associated with later GDM using a pool-based small RNA sequencing approach. Using a systematic and unbiased sequencing strategy with locus-level miRNA resolution, we profiled the first-trimester plasma miRNome and prioritized a set of 18 mature miRNAs from among 255 detected species. Set-level functional enrichment analyses based on curated and predicted miRNA–target interactions derived primarily from cellular and tissue-based studies showed annotation-based convergence on pathways related to Ca²⁺ homeostasis, glucagon–insulin regulatory circuits, and PI3K–AKT signaling. Network analysis indicated coordinated associations among these miRNAs and shared target pathways involved in insulin secretion and insulin sensitivity. Key contributors—including miR-29a-3p, miR-29c-3p, miR-146a-5p, let-7a-5p, and miR-182-5p—were linked, through in silico target annotation, to central metabolic regulators such as PTEN, PIK3R1, AKT1, AKT2, and components of Ca²⁺ signaling (ATP2A2, CALM1/3, ITPR1, RYR2). These circulating miRNAs should be interpreted primarily as biomarkers reflecting coordinated metabolic states rather than as direct causal mediators. Most identified miRNAs have not been previously reported in the context of first-trimester GDM, supporting the exploratory and hypothesis-generating nature of this circulating miRNA signature in early gestational metabolic research. Full article