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Open Biology Jun 2024Hypertrophic cardiomyopathy (HCM) is a monogenic cardiac disorder commonly induced by sarcomere gene mutations. However, the mechanism for HCM is not well defined. Here,...
Hypertrophic cardiomyopathy (HCM) is a monogenic cardiac disorder commonly induced by sarcomere gene mutations. However, the mechanism for HCM is not well defined. Here, we generated transgenic MYH7 R453C and MYH6 R453C piglets and found both developed typical cardiac hypertrophy. Unexpectedly, we found serious fibrosis and cardiomyocyte loss in the ventricular of MYH7 R453C, not MYH6 R453C piglets, similar to HCM patients. Then, RNA-seq analysis and western blotting identified the activation of ERK1/2 and PI3K-Akt pathways in MYH7 R453C. Moreover, we observed an increased expression of fetal genes and an excess of reactive oxygen species (ROS) in MYH7 R453C piglet models, which was produced by Nox4 and subsequently induced inflammatory response. Additionally, the phosphorylation levels of Smad2/3, ERK1/2 and NF-kB p65 proteins were elevated in cardiomyocytes with the MYH7 R453C mutation. Furthermore, epigallocatechin gallate, a natural bioactive compound, could be used as a drug to reduce cell death by adjusting significant downregulation of the protein expression of Bax and upregulated Bcl-2 levels in the H9C2 models with MYH7 R453C mutation. In conclusion, our study illustrated that TGF-β/Smad2/3, ERK1/2 and Nox4/ROS pathways have synergistic effects on cardiac remodelling and inflammation in MYH7 R453C mutation.
Topics: Animals; Myosin Heavy Chains; Transforming Growth Factor beta; NADPH Oxidase 4; Reactive Oxygen Species; NF-kappa B; Signal Transduction; Swine; Myocytes, Cardiac; Humans; Cardiac Myosins; Disease Models, Animal; MAP Kinase Signaling System; Animals, Genetically Modified; Smad2 Protein; Mutation; Smad3 Protein; Ventricular Remodeling; Cardiomyopathy, Hypertrophic; Rats
PubMed: 38862020
DOI: 10.1098/rsob.230427 -
BMC Cancer Jun 2024Our study aims to explore the relationship, shared gene signature, and the underlying mechanisms that connect rheumatoid arthritis (RA) to colorectal cancer (CRC).
Integrated multi-omics analyses revealed the association between rheumatoid arthritis and colorectal cancer: MYO9A as a shared gene signature and an immune-related therapeutic target.
BACKGROUND
Our study aims to explore the relationship, shared gene signature, and the underlying mechanisms that connect rheumatoid arthritis (RA) to colorectal cancer (CRC).
METHODS
Mendelian randomization (MR) analysis was conducted to assess the causality between RA and CRC. Summary statistic data-based Mendelian randomization (SMR) leveraging eQTL data was employed to identify the CRC-related causal genes. Integrated analyses of single-cell RNA sequencing and bulk RNA sequencing were employed to comprehensively investigate the shared gene signature and potential mechanisms underlying the pathogenesis of both RA and CRC. Predictive analysis of the shared hub gene in CRC immunotherapy response was performed. Pan-cancer analyses were conducted to explore the potential role of MYO9A in 33 types of human tumors.
RESULTS
MR analysis suggested that RA might be associated with a slight increased risk of CRC (Odds Ratio = 1.04, 95% Confidence Interval = 1.01-1.07, P = 0.005). SMR analysis combining transcriptome analyses identified MYO9A as a causal gene in CRC and a shared gene signature in both RA and CRC. MYO9A may contribute to tumor suppression, while downregulation of MYO9A may impact CRC tumorigenesis by disrupting epithelial polarity and architecture, resulting in a worse prognosis in CRC. Additionally, MYO9A shows promise as a powerful predictive biomarker for cancer prognosis and immunotherapy response in CRC. Pan-cancer analyses demonstrated MYO9A may have a protective role in the occurrence and progression of various human cancers.
CONCLUSION
RA might be associated with a slight increased risk of CRC. MYO9A is a shared gene signature and a potential immune-related therapeutic target for both CRC and RA. Targeting the MYO9A-mediated loss of polarity and epithelial architecture could be a novel therapeutic approach for CRC.
Topics: Humans; Colorectal Neoplasms; Arthritis, Rheumatoid; Mendelian Randomization Analysis; Myosins; Gene Expression Profiling; Transcriptome; Quantitative Trait Loci; Prognosis; Gene Expression Regulation, Neoplastic; Biomarkers, Tumor; Multiomics
PubMed: 38858644
DOI: 10.1186/s12885-024-12466-5 -
Molecular Cancer Jun 2024Intestinal metaplasia (IM) is classified into complete intestinal metaplasia (CIM) and incomplete intestinal metaplasia (IIM). Patients diagnosed with IIM face an...
BACKGROUND
Intestinal metaplasia (IM) is classified into complete intestinal metaplasia (CIM) and incomplete intestinal metaplasia (IIM). Patients diagnosed with IIM face an elevated susceptibility to the development of gastric cancer, underscoring the critical need for early screening measures. In addition to the complexities associated with diagnosis, the exact mechanisms driving the progression of gastric cancer in IIM patients remain poorly understood. OLFM4 is overexpressed in several types of tumors, including colorectal, gastric, pancreatic, and ovarian cancers, and its expression has been associated with tumor progression.
METHODS
In this study, we used pathological sections from two clinical centers, biopsies of IM tissues, precancerous lesions of gastric cancer (PLGC) cell models, animal models, and organoids to explore the role of OLFM4 in IIM.
RESULTS
Our results show that OLFM4 expression is highly increased in IIM, with superior diagnostic accuracy of IIM when compared to CDX2 and MUC2. OLFM4, along with MYH9, was overexpressed in IM organoids and PLGC animal models. Furthermore, OLFM4, in combination with Myosin heavy chain 9 (MYH9), accelerated the ubiquitination of GSK3β and resulted in increased β-catenin levels through the Wnt signaling pathway, promoting the proliferation and invasion abilities of PLGC cells.
CONCLUSIONS
OLFM4 represents a novel biomarker for IIM and could be utilized as an important auxiliary means to delimit the key population for early gastric cancer screening. Finally, our study identifies cell signaling pathways involved in the progression of IM.
Topics: Humans; Metaplasia; Glycogen Synthase Kinase 3 beta; Animals; beta Catenin; Mice; Myosin Heavy Chains; Disease Progression; Stomach Neoplasms; Female; Wnt Signaling Pathway; Cell Proliferation; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Disease Models, Animal; Male; Organoids
PubMed: 38849840
DOI: 10.1186/s12943-024-02016-9 -
Nature Communications Jun 2024Inherited cardiomyopathies are common cardiac diseases worldwide, leading in the late stage to heart failure and death. The most promising treatments against these...
Inherited cardiomyopathies are common cardiac diseases worldwide, leading in the late stage to heart failure and death. The most promising treatments against these diseases are small molecules directly modulating the force produced by β-cardiac myosin, the molecular motor driving heart contraction. Omecamtiv mecarbil and Mavacamten are two such molecules that completed phase 3 clinical trials, and the inhibitor Mavacamten is now approved by the FDA. In contrast to Mavacamten, Omecamtiv mecarbil acts as an activator of cardiac contractility. Here, we reveal by X-ray crystallography that both drugs target the same pocket and stabilize a pre-stroke structural state, with only few local differences. All-atom molecular dynamics simulations reveal how these molecules produce distinct effects in motor allostery thus impacting force production in opposite way. Altogether, our results provide the framework for rational drug development for the purpose of personalized medicine.
Topics: Myocardial Contraction; Molecular Dynamics Simulation; Crystallography, X-Ray; Humans; Urea; Cardiac Myosins; Ventricular Myosins; Animals; Benzylamines; Uracil
PubMed: 38849353
DOI: 10.1038/s41467-024-47587-9 -
Medicine Jun 2024The dysregulation of protein-coding genes involved in various biological functions is closely associated with the progression of thyroid cancer. This study aimed to...
The dysregulation of protein-coding genes involved in various biological functions is closely associated with the progression of thyroid cancer. This study aimed to investigate the effects of dysregulated gene expressions on the prognosis of classical papillary thyroid carcinoma (cPTC). Using expression profiling datasets from the Cancer Genome Atlas (TCGA) database, we performed differential expression analysis to identify differentially expressed genes (DEGs). Cox regression and Kaplan-Meier analysis were used to identify DEGs, which were used to construct a risk model to predict the prognosis of cPTC patients. Functional enrichment analysis unveiled the potential significance of co-expressed protein-encoding genes in tumors. We identified 4 DEGs (SALL3, PPBP, MYH1, and SYNDIG1), which were used to construct a risk model to predict the prognosis of cPTC patients. These 4 genes were independent of clinical parameters and could be functional in cPTC carcinogenesis. Furthermore, PPBP exhibited a strong correlation with poorer overall survival (OS) in the advanced stage of the disease. This study suggests that the 4-gene signature could be an independent prognostic biomarker to improve prognosis prediction in cPTC patients older than 46.
Topics: Humans; Thyroid Cancer, Papillary; Thyroid Neoplasms; Prognosis; Female; Male; Middle Aged; Biomarkers, Tumor; RNA, Messenger; Kaplan-Meier Estimate; Gene Expression Profiling; Risk Assessment; Gene Expression Regulation, Neoplastic; Myosin Heavy Chains; Transcription Factors; Proportional Hazards Models
PubMed: 38847736
DOI: 10.1097/MD.0000000000038472 -
Circulation Research Jun 2024Autoimmunity significantly contributes to the pathogenesis of myocarditis, underscored by its increased frequency in autoimmune diseases such as systemic lupus... (Review)
Review
Autoimmunity significantly contributes to the pathogenesis of myocarditis, underscored by its increased frequency in autoimmune diseases such as systemic lupus erythematosus and polymyositis. Even in cases of myocarditis caused by viral infections, dysregulated immune responses contribute to pathogenesis. However, whether triggered by existing autoimmune conditions or viral infections, the precise antigens and immunologic pathways driving myocarditis remain incompletely understood. The emergence of myocarditis associated with immune checkpoint inhibitor therapy, commonly used for treating cancer, has afforded an opportunity to understand autoimmune mechanisms in myocarditis, with autoreactive T cells specific for cardiac myosin playing a pivotal role. Despite their self-antigen recognition, cardiac myosin-specific T cells can be present in healthy individuals due to bypassing the thymic selection stage. In recent studies, novel modalities in suppressing the activity of pathogenic T cells including cardiac myosin-specific T cells have proven effective in treating autoimmune myocarditis. This review offers an overview of the current understanding of heart antigens, autoantibodies, and immune cells as the autoimmune mechanisms underlying various forms of myocarditis, along with the latest updates on clinical management and prospects for future research.
Topics: Myocarditis; Humans; Autoimmune Diseases; Animals; Autoantibodies; Autoimmunity; T-Lymphocytes; Autoantigens; Cardiac Myosins
PubMed: 38843292
DOI: 10.1161/CIRCRESAHA.124.323816 -
Research Square May 2024Stereocilia are unidirectional F-actin-based cylindrical protrusions on the apical surface of inner ear hair cells and function as biological mechanosensors of sound and...
Live-cell single-molecule fluorescence microscopy for protruding organelles reveals regulatory mechanisms of MYO7A-driven cargo transport in stereocilia of inner ear hair cells.
Stereocilia are unidirectional F-actin-based cylindrical protrusions on the apical surface of inner ear hair cells and function as biological mechanosensors of sound and acceleration. Development of functional stereocilia requires motor activities of unconventional myosins to transport proteins necessary for elongating the F-actin cores and to assemble the mechanoelectrical transduction (MET) channel complex. However, how each myosin localizes in stereocilia using the energy from ATP hydrolysis is only partially understood. In this study, we develop a methodology for live-cell single-molecule fluorescence microscopy of organelles protruding from the apical surface using a dual-view light-sheet microscope, diSPIM. We demonstrate that MYO7A, a component of the MET machinery, traffics as a dimer in stereocilia. Movements of MYO7A are restricted when scaffolded by the plasma membrane and F-actin as mediated by MYO7A's interacting partners. Here, we discuss the technical details of our methodology and its future applications including analyses of cargo transportation in various organelles.
PubMed: 38826223
DOI: 10.21203/rs.3.rs-4369958/v1 -
Scientific Reports May 2024Hypertrophic cardiomyopathy (HCM) remains the most common cardiomyopathy in humans and cats with few preclinical pharmacologic interventional studies. Small-molecule...
Hypertrophic cardiomyopathy (HCM) remains the most common cardiomyopathy in humans and cats with few preclinical pharmacologic interventional studies. Small-molecule sarcomere inhibitors are promising novel therapeutics for the management of obstructive HCM (oHCM) patients and have shown efficacy in left ventricular outflow tract obstruction (LVOTO) relief. The objective of this study was to explore the 6-, 24-, and 48-hour (h) pharmacodynamic effects of the cardiac myosin inhibitor, CK-586, in six purpose-bred cats with naturally occurring oHCM. A blinded, randomized, five-treatment group, crossover preclinical trial was conducted to assess the pharmacodynamic effects of CK-586 in this oHCM model. Dose assessments and select echocardiographic variables were assessed five times over a 48-h period. Treatment with oral CK-586 safely ameliorated LVOTO in oHCM cats. CK-586 treatment dose-dependently eliminated obstruction (reduced LVOTOmaxPG), increased measures of systolic chamber size (LVIDs Sx), and decreased select measures of heart function (LV FS% and LV EF%) in the absence of impact on heart rate. At all tested doses, a single oral CK-586 dose resulted in improved or resolved LVOTO with well-tolerated, dose-dependent, reductions in LV systolic function. The results from this study pave the way for the potential use of CK-586 in both the veterinary and human clinical setting.
Topics: Animals; Cats; Cardiomyopathy, Hypertrophic; Cardiac Myosins; Cat Diseases; Male; Female; Ventricular Outflow Obstruction; Systole; Echocardiography; Cross-Over Studies
PubMed: 38802475
DOI: 10.1038/s41598-024-62840-3 -
Communications Biology May 2024In 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...
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.
Topics: Animals; Mice, Knockout; Carrier Proteins; Mice; Sarcomeres; Myofibrils; Muscle, Skeletal; Actin Cytoskeleton; Male; Myosins
PubMed: 38802450
DOI: 10.1038/s42003-024-06265-8 -
BioRxiv : the Preprint Server For... May 2024Animal cells build actin-based surface protrusions to enable biological activities ranging from cell motility to mechanosensation to solute uptake. Long-standing models...
UNLABELLED
Animal cells build actin-based surface protrusions to enable biological activities ranging from cell motility to mechanosensation to solute uptake. Long-standing models of protrusion growth suggest that actin filament polymerization provides the primary mechanical force for "pushing" the plasma membrane outward at the distal tip. Expanding on these actin-centric models, our recent studies used a chemically inducible system to establish that plasma membrane-bound myosin motors, which are abundant in protrusions and accumulate at the distal tips, can also power robust filopodial growth. How protrusion resident myosins coordinate with actin polymerization to drive elongation remains unclear, in part because the number of force generators and thus, the scale of their mechanical contributions remain undefined. To address this gap, we leveraged the SunTag system to count membrane-bound myosin motors in actively growing filopodia. Using this approach, we found that the number of myosins is log-normally distributed with a mean of 12.0 ± 2.5 motors [GeoMean ± GeoSD] per filopodium. Together with unitary force values and duty ratio estimates derived from biophysical studies for the motor used in these experiments, we calculate that a distal tip population of myosins could generate a time averaged force of ∼tens of pN to elongate filopodia. This range is comparable to the expected force production of actin polymerization in this system, a point that necessitates revision of popular physical models for protrusion growth.
SIGNIFICANCE STATEMENT
This study describes the results of in-cell molecular counting experiments to define the number of myosin motors that are mechanically active in growing filopodia. This data should be used to constrain future physical models of the formation of actin-based protrusions.
PubMed: 38798618
DOI: 10.1101/2024.05.14.593924