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Nature Communications Jun 2024Phosphorylation of cardiac myosin binding protein-C (cMyBP-C) is a determinant of cardiac myofilament function. Although cMyBP-C phosphorylation by various protein...
Phosphorylation of cardiac myosin binding protein-C (cMyBP-C) is a determinant of cardiac myofilament function. Although cMyBP-C phosphorylation by various protein kinases has been extensively studied, the influence of protein phosphatases on cMyBP-C's multiple phosphorylation sites has remained largely obscure. Here we provide a detailed biochemical characterization of cMyBP-C dephosphorylation by protein phosphatases 1 and 2 A (PP1 and PP2A), and develop an integrated kinetic model for cMyBP-C phosphorylation using data for both PP1, PP2A and various protein kinases known to phosphorylate cMyBP-C. We find strong site-specificity and a hierarchical mechanism for both phosphatases, proceeding in the opposite direction of sequential phosphorylation by potein kinase A. The model is consistent with published data from human patients and predicts complex non-linear cMyBP-C phosphorylation patterns that are validated experimentally. Our results suggest non-redundant roles for PP1 and PP2A under both physiological and heart failure conditions, and emphasize the importance of phosphatases for cMyBP-C regulation.
Topics: Phosphorylation; Humans; Protein Phosphatase 1; Carrier Proteins; Animals; Protein Phosphatase 2; Myocardium; Protein Kinases; Kinetics
PubMed: 38877002
DOI: 10.1038/s41467-024-49408-5 -
PLoS Genetics Jun 2024The Transforming Growth Factor beta (TGF-β) family consists of numerous secreted peptide growth factors that play significant roles in cell function, tissue patterning,...
The Transforming Growth Factor beta (TGF-β) family consists of numerous secreted peptide growth factors that play significant roles in cell function, tissue patterning, and organismal homeostasis, including wound repair and immunity. Typically studied as homodimers, these ligands have the potential to diversify their functions through ligand interactions that may enhance, repress, or generate novel functions. In the nematode Caenorhabditis elegans, there are only five TGF-β ligands, providing an opportunity to dissect ligand interactions in fewer combinations than in vertebrates. As in vertebrates, these ligands can be divided into bone morphogenetic protein (BMP) and TGF-β/Activin subfamilies that predominantly signal through discrete signaling pathways. The BMP subfamily ligand DBL-1 has been well studied for its role in the innate immune response in C. elegans. Here we show that all five TGF-β ligands play a role in survival on bacterial pathogens. We also demonstrate that multiple TGF-β ligand pairs act nonredundantly as part of this response. We show that the two BMP-like ligands-DBL-1 and TIG-2-function independently of each other in the immune response, while TIG-2/BMP and the TGF-β/Activin-like ligand TIG-3 function together. Structural modeling supports the potential for TIG-2 and TIG-3 to form heterodimers. Additionally, we identify TIG-2 and TIG-3 as members of a rare subset of TGF-β ligands lacking the conserved cysteine responsible for disulfide linking mature dimers. Finally, we show that canonical DBL-1/BMP receptor and Smad signal transducers function in the response to bacterial pathogens, while components of the DAF-7 TGF-β/Activin signaling pathway do not play a major role in survival. These results demonstrate a novel potential for BMP and TGF-β/Activin subfamily ligands to interact and may provide a mechanism for distinguishing the developmental and homeostatic functions of these ligands from an acute response such as the innate immune response to bacterial pathogens.
Topics: Animals; Caenorhabditis elegans; Transforming Growth Factor beta; Signal Transduction; Caenorhabditis elegans Proteins; Immunity, Innate; Ligands; Bone Morphogenetic Proteins; Activins; Neuropeptides
PubMed: 38875298
DOI: 10.1371/journal.pgen.1011324 -
PloS One 2024Ewing sarcoma is the second most common bone cancer in children, and while patients who present with metastatic disease at the time of diagnosis have a dismal prognosis....
Ewing sarcoma is the second most common bone cancer in children, and while patients who present with metastatic disease at the time of diagnosis have a dismal prognosis. Ewing sarcoma tumors are driven by the fusion gene EWS/Fli1, and while these tumors are genetically homogenous, the transcriptional heterogeneity can lead to a variety of cellular processes including metastasis. In this study, we demonstrate that in Ewing sarcoma cells, the canonical Wnt/β-Catenin signaling pathway is heterogeneously activated in vitro and in vivo, correlating with hypoxia and EWS/Fli1 activity. Ewing sarcoma cells predominantly express β-Catenin on the cell membrane bound to CDH11, which can respond to exogenous Wnt ligands leading to the immediate activation of Wnt/β-Catenin signaling within a tumor. Knockdown of CDH11 leads to delayed and decreased response to exogenous Wnt ligand stimulation, and ultimately decreased metastatic propensity. Our findings strongly indicate that CDH11 is a key component of regulating Wnt//β-Catenin signaling heterogeneity within Ewing sarcoma tumors, and is a promising molecular target to alter Wnt//β-Catenin signaling in Ewing sarcoma patients.
Topics: Sarcoma, Ewing; Humans; Cadherins; Wnt Signaling Pathway; Cell Line, Tumor; beta Catenin; Animals; Bone Neoplasms; Mice; Oncogene Proteins, Fusion; Proto-Oncogene Protein c-fli-1; RNA-Binding Protein EWS
PubMed: 38875295
DOI: 10.1371/journal.pone.0305490 -
Journal of Ayurveda and Integrative... Jun 2024The emergence and evolution of SARS-CoV-2 resulted a severe threat to public health globally. Due to the lack of an effective vaccine with durable immunity, the disease...
BACKGROUND
The emergence and evolution of SARS-CoV-2 resulted a severe threat to public health globally. Due to the lack of an effective vaccine with durable immunity, the disease transited into the endemic phase, necessitating potent antiviral therapy including a scientific basis for current traditional herbal medicine.
OBJECTIVE
This study aimed to conduct a pharmacoinformatic analysis of selected chemical ingredients and in-vitro evaluation of Cordyceps militaris extract against SARS-CoV-2.
MATERIALS AND METHODS
C. militaris, the widely used fungus in conventional herbal medicine, was subjected to computational investigation using molecular docking, molecular dynamic simulation and network pharmacology analysis followed by the in-vitro assay for evaluating its anti-SARS-CoV-2 potential.
RESULTS
The molecular docking analysis of C. militaris revealed the Cordycepin's highest affinity (-9.71 kcal/mol) than other molecules, i.e., Cicadapeptin-I, Cicadapeptin-II, Cordycerebroside-B, and N-Acetyl galactosamine to the receptor binding domain of the SARS-CoV-2 spike protein. C. militaris aqueous extract could reduce the SARS-CoV-2 viral copy numbers by 50.24% using crude extract at 100 μg/mL concentration.
CONCLUSION
These findings suggest that C. militaris has promising anti-SARS-CoV-2 activity and may be explored as traditional medicine for managing the COVID-19 surge in the endemic phase.
PubMed: 38871595
DOI: 10.1016/j.jaim.2024.100979 -
International Journal of... Apr 2024Patients with human immunodeficiency virus (HIV) infection have an increased likelihood of venous thromboembolism (VTE) owing to factors such as acquired protein C and S...
Patients with human immunodeficiency virus (HIV) infection have an increased likelihood of venous thromboembolism (VTE) owing to factors such as acquired protein C and S deficiency, antiphospholipid antibody syndrome, and heightened levels of pro-inflammatory cytokines. This case report highlights an exceptionally uncommon occurrence of deep venous thrombosis in an HIV-infected patient receiving a therapeutic dose of enoxaparin. This underscores the need for cautious consideration of the risk of VTE in HIV-infected individuals, even with preventive or therapeutic anticoagulant treatment. Further research is recommended to investigate HIV as a potential risk factor of prophylactic anticoagulation.
PubMed: 38868809
DOI: 10.18502/ijhoscr.v18i2.15379 -
The Journal of Biological Chemistry Jun 2024Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a lipid-enveloped virus that acquires its lipid bilayer from the host cell it infects. SARS-CoV-2 can...
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a lipid-enveloped virus that acquires its lipid bilayer from the host cell it infects. SARS-CoV-2 can spread from cell to cell or from patient to patient by undergoing assembly and budding to form new virions. The assembly and budding of SARS-CoV-2 is mediated by several structural proteins known as envelope (E), membrane (M), nucleoprotein (N) and spike (S), which can form virus-like particles (VLPs) when co-expressed in mammalian cells. Assembly and budding of SARS-CoV-2 from the host ER-Golgi intermediate compartment is a critical step in the virus acquiring its lipid bilayer. To date, little information is available on how SARS-CoV-2 assembles and forms new viral particles from host membranes. In this study, we used several lipid binding assays and found the N protein can strongly associate with anionic lipids including phosphoinositides and phosphatidylserine. Moreover, we show lipid binding occurs in the N protein C-terminal domain, which is supported by extensive in silico analysis. We demonstrate anionic lipid binding occurs for both the free and N oligomeric forms, suggesting N can associate with membranes in the nucleocapsid form. Based on these results, we present a lipid-dependent model based on in vitro, cellular and in silico data for the recruitment of N to assembly sites in the lifecycle of SARS-CoV-2.
PubMed: 38866325
DOI: 10.1016/j.jbc.2024.107456 -
Science Advances Jun 2024The molecular mechanisms underlying diversity in animal behavior are not well understood. A major experimental challenge is determining the contribution of genetic...
The molecular mechanisms underlying diversity in animal behavior are not well understood. A major experimental challenge is determining the contribution of genetic variants that affect neuronal gene expression to differences in behavioral traits. In , the neuroendocrine transforming growth factor-β ligand, DAF-7, regulates diverse behavioral responses to bacterial food and pathogens. The dynamic neuron-specific expression of is modulated by environmental and endogenous bacteria-derived cues. Here, we investigated natural variation in the expression of from the ASJ pair of chemosensory neurons. We identified common genetic variants in , encoding a Ras guanosine triphosphatase (GTPase)-activating protein homologous to mammalian synaptic Ras GTPase-activating protein, which modify expression cell nonautonomously and promote exploratory foraging behavior in a partially DAF-7-dependent manner. Our data connect natural variation in neuron-specific gene expression to differences in behavior and suggest that genetic variation in neuroendocrine signaling pathways mediating host-microbe interactions may give rise to diversity in animal behavior.
Topics: Animals; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Genetic Variation; Gene Expression Regulation; Neurosecretory Systems; Feeding Behavior; Behavior, Animal; Neurons; Signal Transduction; Transforming Growth Factor beta
PubMed: 38865452
DOI: 10.1126/sciadv.adk9481 -
Immunity, Inflammation and Disease Jun 2024Severe cases of COVID-19 often lead to the development of acute respiratory syndrome, a critical condition believed to be caused by the harmful effects of SARS-CoV-2 on... (Review)
Review
BACKGROUND
Severe cases of COVID-19 often lead to the development of acute respiratory syndrome, a critical condition believed to be caused by the harmful effects of SARS-CoV-2 on type II alveolar cells. These cells play a crucial role in producing pulmonary surfactants, which are essential for proper lung function. Specifically focusing on surfactant proteins, including Surfactant protein A (SP-A), Surfactant protein B, Surfactant protein C, and Surfactant protein D (SP-D), changes in the levels of pulmonary surfactants may be a significant factor in the pathological changes seen in COVID-19 infection.
OBJECTIVE
This study aims to gain insights into surfactants, particularly their impacts and changes during COVID-19 infection, through a comprehensive review of current literature. The study focuses on the function of surfactants as prognostic markers, diagnostic factors, and essential components in the management and treatment of COVID-19.
FINDING
In general, pulmonary surfactants serve to reduce the surface tension at the gas-liquid interface, thereby significantly contributing to the regulation of respiratory mechanics. Additionally, these surfactants play a crucial role in the innate immune system within the pulmonary microenvironment. Within the spectrum of COVID-19 infections, a compelling association is observed, characterized by elevated levels of SP-D and SP-A across a range of manifestations from mild to severe pneumonia. The sudden decline in respiratory function observed in COVID-19 patients may be attributed to the decreased synthesis of surfactants by type II alveolar cells.
CONCLUSION
Collectin proteins such as SP-A and SP-D show promise as biomarkers, offering potential avenues for predicting and monitoring pulmonary alveolar injury in the context of COVID-19. This clarification enhances our understanding of the molecular complexities contributing to respiratory complications in severe COVID-19 cases, providing a foundation for targeted therapeutic approaches using surfactants and refined clinical management strategies.
Topics: COVID-19; Humans; SARS-CoV-2; Pulmonary Surfactant-Associated Proteins; Pulmonary Surfactants; Biomarkers; Pulmonary Surfactant-Associated Protein D; Prognosis; Lung
PubMed: 38860749
DOI: 10.1002/iid3.1302 -
Nature Communications Jun 2024Cell polarity mechanisms allow the formation of specialized membrane domains with unique protein compositions, signalling properties, and functional characteristics. By...
Cell polarity mechanisms allow the formation of specialized membrane domains with unique protein compositions, signalling properties, and functional characteristics. By analyzing the localization of potassium channels and proteins belonging to the dystrophin-associated protein complex, we reveal the existence of distinct planar-polarized membrane compartments at the surface of C. elegans muscle cells. We find that muscle polarity is controlled by a non-canonical Wnt signalling cascade involving the ligand EGL-20/Wnt, the receptor CAM-1/Ror, and the intracellular effector DSH-1/Dishevelled. Interestingly, classical planar cell polarity proteins are not required for this process. Using time-resolved protein degradation, we demonstrate that -while it is essentially in place by the end of embryogenesis- muscle polarity is a dynamic state, requiring continued presence of DSH-1 throughout post-embryonic life. Our results reveal the unsuspected complexity of the C. elegans muscle membrane and establish a genetically tractable model system to study cellular polarity and membrane compartmentalization in vivo.
Topics: Animals; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Cell Polarity; Dystrophin; Wnt Signaling Pathway; Muscles; Dishevelled Proteins; Receptor Tyrosine Kinase-like Orphan Receptors; Cell Membrane; Dystrophin-Associated Protein Complex; Wnt Proteins; Signal Transduction
PubMed: 38858388
DOI: 10.1038/s41467-024-49154-8 -
BioRxiv : the Preprint Server For... May 2024, encoding cardiac myosin binding protein-C (cMyBP-C), is the most mutated gene known to cause hypertrophic cardiomyopathy (HCM). However, since little is known about...
BACKGROUND
, encoding cardiac myosin binding protein-C (cMyBP-C), is the most mutated gene known to cause hypertrophic cardiomyopathy (HCM). However, since little is known about the underlying etiology, additional studies are crucial to defining the underlying molecular mechanisms. Accordingly, this study aimed to investigate the molecular mechanisms underlying the pathogenesis of HCM associated with a polymorphic variant (D389V) in by using human-induced pluripotent stem cell (hiPSC)-derived cardiac organoids (hCOs).
METHODS
The hiPSC-derived cardiomyocytes (hiPSC-CMs) and hCOs were generated from human subjects to define the molecular, cellular, and functional changes caused by the variant. This variant is associated with increased fractional shortening and is highly prevalent in South Asian descendants. Recombinant C0-C2, N'-region of cMyBP-C (wildtype and D389V), and myosin S2 proteins were also utilized to perform binding and motility assays .
RESULTS
Confocal and electron microscopic analyses of hCOs generated from noncarriers (NC) and carriers of the variant revealed the presence of highly organized sarcomeres. Furthermore, functional experiments showed hypercontractility with increased contraction velocity, faster calcium cycling, and faster contractile kinetics in hCOs expressing than NC hCOs. Interestingly, significantly increased cMyBP-C phosphorylation in hCOs was observed, but without changes in total protein levels, in addition to higher oxidative stress and lower mitochondrial membrane potential (ΔΨm). Next, spatial mapping revealed the presence of endothelial cells, fibroblasts, macrophages, immune cells, and cardiomyocytes in the hCOs. The hypercontractile function was significantly improved after treatment with the myosin inhibitor mavacamten (CAMZYOS®) in hCOs. Lastly, various binding assays revealed a significant loss of affinity in the presence of with myosin S2 region as a likely mechanism for hypercontraction.
CONCLUSIONS
Conceptually, we showed the feasibility of assessing the functional and molecular mechanisms of HCM using highly translatable hCOs through pragmatic experiments that led to determining the hypercontractile phenotype, which was rescued by administration of a myosin inhibitor. mutations have been implicated in hypertrophic cardiomyopathy. D389V is a polymorphic variant of predicted to be present in 53000 US South Asians owing to the founder effect. D389V carriers have shown evidence of hyperdynamic heart, and human-induced pluripotent stem cells (hiPSC)-derived cardiomyocytes with D389V show cellular hypertrophy and irregular calcium transients. The molecular mechanism by which the D389V variant develops pathological cardiac dysfunction remains to be conclusively determined. The authors leveraged a highly translational cardiac organoid model to explore the role of altered cardiac calcium handling and cardiac contractility as a common pathway leading to pathophysiological phenotypes in patients with early HCM. The -mediated pathological pathway is first studied here by comparing functional properties using three-dimensional cardiac organoids differentiated from hiPSC and determining the presence of hypercontraction. Our data demonstrate that faster sarcomere kinetics resulting from lower binding affinity between D389V-mutated cMyBP-C protein and myosin S2, as evidenced by studies, could cause hypercontractility which was rescued by administration of mavacamten (CAMZYOS®), a myosin inhibitor. In addition, hypercontractility causes secondary mitochondrial defects such as higher oxidative stress and lower mitochondrial membrane potential (ΔΨm), highlighting a possible early adaptive response to primary sarcomeric changes. Early treatment of carriers with mavacamten may prevent or reduce early HCM-related pathology. A graphical abstract is available for this article.
PubMed: 38853909
DOI: 10.1101/2024.05.29.596463