Ion Channel Proteins Research Articles

Use of potassium ion channel and spliceosome proteins as diagnostic biomarkers for sudden unexplained death in schizophrenia

Sudden unexplained death in schizophrenia (SUD-SCZ) is not uncommon and its incidence is approximately three times higher than that in the general population. However, diagnosis of SUD-SCZ remains a great challenge in forensic pathology. This study designed a two-phase study to investigate whether three proteins, namely two potassium ion channel proteins (KCNJ3 and KCNAB1) and one spliceosome protein (SF3B3) that were identified in our previous work, could be applied in the postmortem diagnosis of SUD-SCZ. Immunohistochemical staining of the three biomarkers, followed by a rigorous quantitative analysis, was performed on heart specimens from both SUD-SCZ and control groups. A diagnostic software based on the logistic regression formula derived from the test phase data was then constructed. In the test phase, we found that the staining intensities of KCNJ3, KCNAB1, and SF3B3 were all significantly lower in the SUD-SCZ group (n = 20) as compared with the control group that died from non-natural causes (n = 25), with fold-changes being 14.85 (p < 0.001), 4.13 (p = 0.028) and 2.12 (p = 0.048), respectively. Receiver operating characteristic analysis further illustrated that combination of the three biomarkers achieved the optimal diagnostic specificity (92%) and area under the curve (0.886). In the validation phase, the diagnostic software was confirmed to be a promising tool for predicting the risk of SUD-SCZ in authentic cases. Our study provided a valid strategy towards the practical diagnosis of SUD-SCZ by using KCNJ3, KCNAB1, and SF3B3 proteins as diagnostic biomarkers.

Site-Specific Fluorescent Labeling of the Cysteine-Rich Toxin, DkTx, for TRPV1 Ion Channel Imaging and Membrane Binding Studies.

Peptide toxins secreted by venomous animals bind to mammalian ion channel proteins and modulate their function. The high specificity of these toxins for their target ion channels enables them to serve as powerful tools for ion channel biology. Toxins labeled with fluorescent dyes are employed for the cellular imaging of channels and also for studying toxin-channel and toxin-membrane interactions. Several of these toxins are cysteine-rich, rendering the production of properly folded fluorescently labeled toxins technically challenging. Herein, we evaluate a variety of site-specific protein bioconjugation approaches for producing fluorescently labeled double-knot toxin (DkTx), a potent TRPV1 ion channel agonist that contains an uncommonly large number of cysteines (12 out of a total of 75 amino acids present in the protein). We find that popular cysteine-mediated bioconjugation approaches are unsuccessful as the introduction of a non-native cysteine residue for thiol modification leads to the formation of misfolded toxin species. Moreover, N-terminal aldehyde-mediated bioconjugation approaches are also not suitable as the resultant labeled toxin lacks activity. In contrast to these approaches, C-terminal bioconjugation of DkTx via the sortase bioconjugation technology yields functionally active fluorescently labeled DkTx. We employ this labeled toxin for imaging rat TRPV1 heterologously expressed in Xenopus laevis oocytes, as well as for performing membrane binding studies on giant unilamellar vesicles composed of different lipid compositions. Our studies set the stage for using fluorescent DkTx as a tool for TRPV1 biology and provide an informative blueprint for labeling cysteine-rich proteins.

In-situ and amplification-free imaging of hERG ion channels at single-cell level using a unique core-molecule-shell-secondary antibody SERS nanoprobe

Research on ion channels and their monoclonal antibodies plays a critical role in drug development and disease diagnosis. The current ion channel researches are often not conducted in the microenvironment for cells survival, which restricts the mechanism study of the links between the cell structure and the ion channel function. In this work, we synthesized gold core-4-mercaptobenzonitrile-sliver shell-goat anti-rabbit immunoglobulin G (Au@4-MBN@Ag@IgG) nanoparticles as surface-enhanced Raman scattering (SERS) nanoprobes for investigating the human ether-a-go-go related gene (hERG) potassium ion channel in cell membranes. This is the first attempt to study ion channels using SERS. Due to the unique core-molecule-shell structure and the silver shell of nanoprobes, strong and stable SERS signal was obtained. With the help of antibodies, the Au@4-MBN@Ag@IgG nanoprobes were captured by hERG antibodies and then bonded with hERG ion channels based on the sandwich immune response. The reporter molecule, 4-MBN, displayed a strong and sharp characteristic peak at 2233 cm-1 in the Raman silent region. The intensity of this peak denoted the concentration of antibodies and the expression of ion channel proteins. We successfully applied this amplification-free method for in-situ imaging the distribution of the hERG ion channel on the transfected HEK293 cell surface at the single-cell level. This hERG ion channel profiling strategy promises a maneuverable tool for ion channel research.

Revealing nanostructures in brain tissue via protein decrowding by iterative expansion microscopy.

Many crowded biomolecular structures in cells and tissues are inaccessible to labelling antibodies. To understand how proteins within these structures are arranged with nanoscale precision therefore requires that these structures be decrowded before labelling. Here we show that an iterative variant of expansion microscopy (the permeation of cells and tissues by a swellable hydrogel followed by isotropic hydrogel expansion, to allow for enhanced imaging resolution with ordinary microscopes) enables the imaging of nanostructures in expanded yet otherwise intact tissues at a resolution of about 20 nm. The method, which we named 'expansion revealing' and validated with DNA-probe-based super-resolution microscopy, involves gel-anchoring reagents and the embedding, expansion and re-embedding of the sample in homogeneous swellable hydrogels. Expansion revealing enabled us to use confocal microscopy to image the alignment of pre-synaptic calcium channels with post-synaptic scaffolding proteins in intact brain circuits, and to uncover periodic amyloid nanoclusters containing ion-channel proteins in brain tissue from a mouse model of Alzheimer's disease. Expansion revealing will enable the further discovery of previously unseen nanostructures within cells and tissues.

An efficient finite element iterative method for solving a nonuniform size modified Poisson-Boltzmann ion channel model

In this paper, a nonuniform size modified Poisson-Boltzmann ion channel (nuSMPBIC) model is presented as a nonlinear system of an electrostatic potential and multiple ionic concentrations. It mixes nonlinear algebraic equations with a Poisson boundary value problem involving Dirichlet-Neumann mixed boundary value conditions and a membrane surface charge density to reflect the effects of ion sizes and membrane charges on electrostatics and ionic concentrations. To overcome the difficulties of strong singularities and exponential nonlinearities, it is split into three submodels with a solution of Model 1 collecting all the singular points and Models 2 and 3 much easier to solve numerically than the original nuSMPBIC model. A damped two-block iterative method is then presented to solve Model 3, along with a novel modified Newton iterative scheme for solving each related nonlinear algebraic system. To this end, an effective nuSMPBIC finite element solver is derived and then implemented as a program package that works for an ion channel protein with a three-dimensional molecular structure and a mixture of multiple ionic species. Numerical results for a voltage-dependent anion channel (VDAC) in a mixture of four ionic species demonstrate a fast convergence rate of the damped two-block iterative method, the high performance of the software package, and the importance of considering nonuniform ion sizes. Moreover, the nuSMPBIC model is validated by the anion selectivity property of VDAC.

Using Metadynamics To Explore the Free Energy of Dewetting in Biologically Relevant Nanopores.

Water confined within hydrophobic spaces can undergo cooperative dewetting transitions due to slight changes in water density and pressure that push water toward the vapor phase. Many transmembrane protein ion channels contain nanoscale hydrophobic pores that could undergo dewetting transitions, sometimes blocking the flow of ions without physical blockages. Standard molecular dynamics simulations have been extensively applied to study the behavior of water in nanoscale pores, but the large free energy barriers of dewetting often prevent direct sampling of both wet and dry states and quantitative studies of the hydration thermodynamics of biologically relevant pores. Here, we describe a metadynamics protocol that uses the number of waters within the pore as the collective variable to drive many reversible transitions between relevant hydration states and calculate well-converged free energy profiles of pore hydration. By creating model nanopore systems and changing their radius and morphology and including various cosolvents, we quantify how these pore properties and cosolvents affect the dewetting transition. The results reveal that the dewetting free energy of nanoscale pores is determined by two key thermodynamic parameters, namely, the effective surface tension coefficients of water-air and water-pore interfaces. Importantly, while the effect of salt can be fully captured in the water activity dependence, amphipathic cosolvents such as alcohols modify both dry and wet states of the pore and dramatically shift the wet-dry equilibrium. The metadynamics approach could be applied to studies of dewetting transitions within nanoscale pores of proteins and provide new insights into why different pore properties evolved in biological systems.

A pan-cancer analysis reveals the genetic alterations and immunotherapy of Piezo2 in human cancer.

Background: Piezo2 is a transmembrane-spanning ion channel protein implicated in multiple physiological processes, including cell proliferation and angiogenesis in many cell types. However, Piezo2 was recognized as representing a double-edged sword in terms of tumor growth. The prognostic and immunotherapeutic roles of Piezo2 in pan-cancer have not been reported. Methods: In this study, several databases available including the UCSC Xena database, HPA, TIDE, GSEA, and cBioportal were used to investigate the expression, alterations, associations with immune indicators, and prognostic roles of Piezo2 across pan-cancer. R software and Perl scripts were used to process the raw data acquired from the UCSC Xena database. Results: Based on processed data, our results suggested that Piezo2 expression levels were tissue-dependent in different tumor tissues. Meanwhile, the survival analysis reflected that patients suffering from KIRC, LUAD, and USC with high Piezo2 expression had good OS, while those suffering from KIRP and SARC with high Piezo2 expression had poor OS. In addition, our results showed that Piezo2 expression was associated with the infiltration of CD4+ T memory cells, mast cells, and dendritic cells. These results suggested that Piezo2 may involve tumor progression by influencing immune infiltration or regulating immune cell function. Further analysis indicated that Piezo2 could influence TME by regulating T-cell dysfunction. We also found that gene mutation was the most common genetic alteration of Piezo2. The GSEA analysis revealed that Piezo2 was associated with calcium ion transport, the activation of the immune response, antigen processing and presentation pathways. Conclusion: Our study showed the expression and prognostic features of Piezo2 and highlighted its associations with genetic alterations and immune signatures in pan-cancer. Moreover, we provided several novel insights for further research on the therapeutic potential of Piezo2.

Evolution of long-distance signalling upon plant terrestrialization: comparison of action potentials in Characean algae and liverworts.

In this review, we summarize data concerning action potentials (APs) - long-distance electrical signals in Characean algae and liverworts. These lineages are key in understanding the mechanisms of plant terrestrialization. Liverworts are postulated to be pioneer land plants, whereas aquatic charophytes are considered the closest relatives to land plants. The drastic change of the habitat was coupled with the adaptation of signalling systems to the new environment. APs fulfil the 'all-or-nothing' law, exhibit refractory periods and propagate with a uniform velocity. Their ion mechanism in the algae and liverworts consists of a Ca2+ influx (from external and internal stores) followed by/coincident with a Cl- efflux, which both evoke the membrane potential depolarization, and a K+ efflux leading to repolarization. The molecular identity of ion channels responsible for these fluxes remains unknown. Publication of the Chara braunii and Marchantia polymorpha genomes opened up new possibilities for studying the molecular basis of APs. Here we present the list of genes which can participate in AP electrogenesis. We also point out the differences between these plant species, e.g. the absence of Ca2+-permeable glutamate receptors (GLRs) and Cl--permeable SLAC1 channel homologues in the Chara genome. Both these channels play a vital role in long-distance signalling in liverworts and vascular plants. Among the common properties of APs in liverworts and higher plants is their duration (dozens of seconds) and the speed of propagation (mm s-1), which are much slower than in the algae (seconds, and dozens of mm s-1, respectively). Future studies with combined application of electrophysiological and molecular techniques should unravel the ion channel proteins responsible for AP generation, their regulation and transduction of those signals to physiological responses. This should also help to understand the adaptation of the signalling systems to the land environment and further evolution of APs in vascular plants.

Genetic Profile of Left Ventricular Noncompaction Cardiomyopathy in Children-A Single Reference Center Experience.

Background: Left ventricular noncompaction cardiomyopathy (LVNC) is a rare cardiac disorder characterised by the presence of a two-layer myocardium with prominent ventricular trabeculation, intertrabecular deep depressions and an increased risk of heart failure, atrial and ventricular arrhythmias and systemic thromboembolic events in affected patients. The heterogeneous molecular aetiology solved in 10%–50% of patients more frequently involves sarcomeric, cytoskeletal or ion channel protein dysfunction—mainly related to causative MYH7, TTN or MYBPC3 variants. The aim of the study was to determine the molecular spectrum of isolated LVNC in a group of children examined in a single paediatric reference centre. Methods: Thirty-one paediatric patients prospectively diagnosed with LVNC by echocardiography and cardiovascular magnetic resonance examination were recruited into the study group. The molecular analysis included next-generation sequencing (gene panel or whole exome) and classic Sanger sequencing. All selected variants with high priority were co-segregated in the available parents. Results: We identified 16 distinct variants in 11 genes in 16 patients (52%), including 10 novel alterations. The most frequent defects in our cohort were found in the genes HCN4 (n = 4), MYH7 (n = 2) and PRDM16 (n = 2). Other likely disease-causing variants were detected in ACTC1, ACTN2, HCCS, LAMA4, MYH6, RBM20, TAFFAZIN and TTN. Patients with established molecular defects more often presented with arrhythmia, thromboembolic events and death, whereas the predominant symptoms in patients with no identified molecular defects were heart failure and the presence of late gadolinium enhancement. Conclusion: This study expands the genetic and clinical spectrum of childhood LVNC. Although the molecular aetiology of LVNC varies widely, the comprehensive testing of a wide panel of cardiomyopathy-related genes helped to identify underlying molecular defects in more than half of the children in the study group. The molecular spectrum in our cohort correlated with the occurrence of arrhythmia, death and a family history of cardiomyopathy. We confirmed that genetic testing is an integral part of the work-up and management LVNC in children.

Mesenchymal stem cells derived from adipose accelerate the progression of colon cancer by inducing a MT-CAFs phenotype via TRPC3/NF-KB axis

BackgroundThere is increasing evidence that mesenchymal stem cells (MSCs) help shape the tumor microenvironment and promote tumor progression, and ion channels might play a critical role in this process. The objective of the present study was to explore the function and mechanism of MT-CAFs on progression of colon cancer.MethodsHere, a gene chip was used for a general analysis of gene expression changes in MSC-transformed CAF cells (MT-CAFs). Bioinformatic tool and western blot screened out the ion channel protein TRPC3 with significantly increased expression, and identify the function through two-photon microscope. The progression of cancer was detected via MTS, transwell and Wound Healing. ELISA deected the secretion of inflammation factors. TRPC3/NF-KB axis was identified by western blot and immunofluorescence.ResultsTRPC3 can caused calcium influx, which further activated the NF-KB signaling pathway. Knockdown or inhibition of TRPC3 in MSCs significantly reduced the activation of NF-KB, and decreased the growth, migration, and invasion of MT-CAFs. After TRPC3 knockdown, the ability of MT- CAFs to promote tumor migration and invasion was impaired. Conversely, the upregulation of TRPC3 expression in MT-CAFs had the opposite effect. In vivo, TRPC3 expressed on MSCs also contributed to the tumorigenesis and progression of cancer cells. In addition, the Oncomine and GEPIA databases showed that TRPC3 expression is higher in colon cancer tissues compared with normal colon tissues, and was positively correlated with the expression of the CAF genes alpha-smooth muscle (α-SMA/ACTA2) and fibroblast activation protein Alpha. The disease-free survival of patients with positive TRPC3 expression in MSCs was significantly shorter than those with negative expression.ConclusionsThese results indicate that TRPC3 expressed on MT-CAFs plays a critical role in tumor progression via the NF-KB signaling pathway, and is correlated with poor prognosis in colon cancer patients. Therefore, TRPC3 may be a novel therapeutic target for the treatment of colon cancer.

Abnormal levels of mitochondrial Ca2+ channel proteins in plasma neuron-derived extracellular vesicles of early schizophrenia.

Structural alterations or quantitative abnormalities of some mitochondrial ion channels and exchangers are associated with altered neuronal functions and increased susceptibility to mental illness. Here we have assessed levels of functionally prominent mitochondrial calcium ion channel proteins in plasma neuron-derived extracellular vesicles (NDEVs) of living patients with first episodes of psychosis (FP) and matched controls (Cs). NDEVs were enriched with an established method of precipitation and immunoabsorption by anti-human CD171 neural adhesion protein (L1CAM) antibody and extracted proteins quantified with ELISAs. CD81 exosome marker-normalized NDEV levels of leucine zipper EF-hand containing transmembrane 1 protein (LETM1), transient receptor potential cation channel subfamily M, member 4 (TRPM4), and solute carrier family 8 member B1 (SLC24A6) or mitochondrial Na+ /Ca2+ exchanger (NCLX) were significantly lower for FP patients (n=10) than Cs (n=10), whereas NDEV levels of voltage-dependent L-type calcium channel subunit α-1C (CACNA-1C) were significantly higher for FP patients than Cs. Abnormal structures or mitochondrial levels of LETM1, NCLX, and CACNA-1C have been linked through analyses of individual proteins, genome-wide association studies, and whole exome protein-coding sequence studies to neurodevelopmental disorders, mental retardation, schizophrenia, and major depressive diseases. A greater understanding of the altered calcium homeostasis in schizophrenia, that is attributable to underlying mitochondrial calcium channel abnormalities, will lead to improved diagnosis and treatment.

Prediction and verification of potential lead analgesic and antiarrhythmic components in Corydalis yanhusuo W. T. Wang based on voltage-gated sodium channel proteins

Corydalis yanhusuo W. T. Wang, a traditional Chinese herbal medicine, has been used as an analgesic for thousands of years and it also promotes blood circulation. In this study, 33 Corydalis yanhusuo alkaloid active components were acquired from Traditional Chinese Medicine Database and Analysis Platform (TCMSP). A total of 543 pain-related targets, 1774 arrhythmia targets, and 642 potential targets of these active components were obtained using Swiss Target Prediction, GeneCards, Open Target Platform, and Therapeutic Target Database. Fifty intersecting targets were visualized through a Venn diagram, KEGG and GO pathway enrichment analysis. The analysis proposed that sodium ion channels are likely potential targets of Corydalis yanhusuo active components as analgesia and anti-arrhythmia agents. Molecular docking showed that the 33 components could bind to Nav1.7 and Nav1.5 (two subtypes of ion channel proteins) with different binding energies. In a patch clamp study, dihydrosanguinarine and dihydrochelerythrine, two monomers with the strongest binding effects, could inhibit the peak currents and promote both activation and inactivation phases of Nav1.5. Meanwhile, dihydrosanguinarine and dihydrochelerythrine could also inhibit peak currents and promote the activation phase of Nav1.7. Therefore, the findings from this study provide valuable information for future uses of traditional Chinese medicines to treat pain and cardiovascular disease.

HDAC1 regulates inflammation and osteogenic differentiation of ankylosing spondylitis fibroblasts through the Wnt-Smad signaling pathway

Ankylosing spondylitis (AS) is a refractory autoimmune disease, whose typical pathology is the development of inflammation to ossification and ankylosis. Histone deacetylase 1 (HDAC1) is considered to be a key factor involved in inflammatory gene transduction, but its role in AS remains unclear. The purpose of this study was to explore the role and possible mechanism of HDAC1 in AS based on the Wnt-Smad pathway. Fibroblasts were isolated from hip synovial tissues of AS patients, adeno-associated virus (AAV) was used to regulate the expression of HDAC1, DKK-1 and SIS3 was used to inhibit Wnt and Smad, respectively. The expressions of Wnt-Smad pathway-related proteins were analyzed by WB, and the TRP ion channel proteins were analyzed by immunofluorescence and WB. The proliferation of AS fibroblasts was detected by CCK-8, the expression of inflammatory cytokines was detected by ELISA, and the effects of HDAC1 on osteogenic differentiation of AS fibroblasts were investigated by alkaline phosphatase (ALP) activity, intracellular calcium concentration, mineralization and osteogenic proteins expressions. Results showed that HDAC1 significantly affected the protein expressions of the Wnt-Smad pathway in AS fibroblasts, and Wnt inhibitor DKK-1 and Smad3 inhibitor SIS3 could significantly reverse the effect of HDAC1 on the Wnt-Smad pathway. In addition, HDAC1 significantly activated the TRP ion channel and promoted the proliferation, inflammatory response and osteogenic differentiation of AS fibroblasts. DKK-1 or SIS3 treatment significantly inhibit the effect of HDAC-1 on AS fibroblasts, suggesting that the Wnt-Smad pathway is involved in the regulation of AS by HDAC1. In conclusion, HDAC1 promotes the proliferation, inflammatory response and osteogenic differentiation of AS fibroblasts through the Wnt-Smad pathway.

Knockout of Sorbin And SH3 Domain Containing 2 (Sorbs2) in Cardiomyocytes Leads to Dilated Cardiomyopathy in Mice.

BackgroundSorbin and SH3 domain containing 2 (Sorbs2) protein is a cytoskeletal adaptor with an emerging role in cardiac biology and disease; yet, its potential relevance to adult‐onset cardiomyopathies remains underexplored. Sorbs2 global knockout mice display lethal arrhythmogenic cardiomyopathy; however, the causative mechanisms remain unclear. Herein, we examine Sorbs2 dysregulation in heart failure, characterize novel Sorbs2 cardiomyocyte‐specific knockout mice (Sorbs2‐cKO), and explore associations between Sorbs2 genetic variations and human cardiovascular disease.Methods and ResultsBioinformatic analyses show myocardial Sorbs2 mRNA is consistently upregulated in humans with adult‐onset cardiomyopathies and in heart failure models. We generated Sorbs2‐cKO mice and report that they develop progressive systolic dysfunction and enlarged cardiac chambers, and they die with congestive heart failure at about 1 year old. After 3 months, Sorbs2‐cKO mice begin to show atrial enlargement and P‐wave anomalies, without dysregulation of action potential–associated ion channel and gap junction protein expressions. After 6 months, Sorbs2‐cKO mice exhibit impaired contractility in dobutamine‐treated hearts and skinned myofibers, without dysregulation of contractile protein expressions. From our comprehensive survey of potential mechanisms, we found that within 4 months, Sorbs2‐cKO hearts have defective microtubule polymerization and compensatory upregulation of structural cytoskeletal and adapter proteins, suggesting that this early intracellular structural remodeling is responsible for contractile dysfunction. Finally, we identified genetic variants that associate with decreased Sorbs2 expression and human cardiac phenotypes, including conduction abnormalities, atrial enlargement, and dilated cardiomyopathy, consistent with Sorbs2‐cKO mice phenotypes.ConclusionsOur studies show that Sorbs2 is essential for maintaining structural integrity in cardiomyocytes, likely through strengthening the interactions between microtubules and other cytoskeletal proteins at cross‐link sites.

A Fluorescence-based Assay of Membrane Potential for High-throughput Functional Study of Two Endogenous Ion Channels in Two Epithelial Cell Lines.

Fluorescence-based studies are suitable for high-throughput plate reader assays of cells in culture. They have been commonly employed for drug discovery campaigns targeting recombinant ion channel proteins overexpressed in cells such as HEK-293 cells. However, there is increasing emphasis on the use of tissue-relevant cell lines for studying the effects of small molecule interventions. The following protocol describes the adaptation of a fluorescence-based membrane potential assay for the study of ion channels endogenously expressed in epithelial cell lines. The membrane potential assay details a high-throughput assay for chloride channel activity of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) in two commonly studied epithelial cell lines, Caco-2 and Calu-3. In addition, this paper describes a novel application of this system to measure the activity of the Epithelial Sodium Channel (ENaC) in a high-throughput format in the same epithelial cell lines. Together, these fluorescence-based assays provide a robust and flexible platform for studying small molecule modulators, targeting two epithelial channels in a relevant cellular context.

A Pancancer Study of PIEZO1 as a Prognosis and Immune Biomarker of Human Tumors.

PIEZO1, a mechanosensitive ion channel protein, has been identified in the correlation between several cancers. However, the systematic pancancer study of PIEZO1 still lacks. We examined PIEZO1 across thirty-three types of cancers to explore its role in prognosis and immunological function for the first time. Based on the open databases TCGA, GTEx and CPTAC, PIEZO1 has been demonstrated to be differentially expressed in most cancers compared to adjacent normal tissues. The distinct correlation between PIEZO1 and prognosis of tumor patients was explored by GEPIA2. Genetic alteration of PIEZO1 in the TCGA tumors showed that mutation is the alteration which is linked to OS, DSS, DFS and PFS in some tumors. Alterations of protein phosphorylation levels were detected in some cancers based on the CPTAC dataset. PIEZO1 expression was linked with immune cell infiltration, such as endothelial cell and cancer-associated fibroblast. Finally, KEGG and GO enrichment analyses were applied to investigate the molecular mechanism of PIEZO1. Our first pancancer analysis illustrated the roles of PIEZO1 in different types of tumors.

Mechanistic Understanding of Lung Inflammation: Recent Advances and Emerging Techniques.

Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury characterized by an acute inflammatory response in the lung parenchyma. Hence, it is considered as the most appropriate clinical syndrome to study pathogenic mechanisms of lung inflammation. ARDS is associated with increased morbidity and mortality in the intensive care unit (ICU), while no effective pharmacological treatment exists. It is very important therefore to fully characterize the underlying pathobiology and the related mechanisms, in order to develop novel therapeutic approaches. In vivo and in vitro models are important pre-clinical tools in biological and medical research in the mechanistic and pathological understanding of the majority of diseases. In this review, we will present data from selected experimental models of lung injury/acute lung inflammation, which have been based on clinical disorders that can lead to the development of ARDS and related inflammatory lung processes in humans, including ventilation-induced lung injury (VILI), sepsis, ischemia/reperfusion, smoke, acid aspiration, radiation, transfusion-related acute lung injury (TRALI), influenza, Streptococcus (S.) pneumoniae and coronaviruses infection. Data from the corresponding clinical conditions will also be presented. The mechanisms related to lung inflammation that will be covered are oxidative stress, neutrophil extracellular traps, mitogen-activated protein kinase (MAPK) pathways, surfactant, and water and ion channels. Finally, we will present a brief overview of emerging techniques in the field of omics research that have been applied to ARDS research, encompassing genomics, transcriptomics, proteomics, and metabolomics, which may recognize factors to help stratify ICU patients at risk, predict their prognosis, and possibly, serve as more specific therapeutic targets.

Analysis of the Transcriptional Dynamics of Regulatory Genes During Peanut Pod Development Caused by Darkness and Mechanical Stress

Peanut is an oil crop with important economic value that is widely cultivated around the world. It blooms on the ground but bears fruit underground. When the peg penetrates the ground, it enters a dark environment, is subjected to mechanical stress from the soil, and develops into a normal pod. When a newly developed pod emerges from the soil, it turns green and stops growing. It has been reported that both darkness and mechanical stress are necessary for normal pod development. In this study, we investigated changes in gene expression during the reverse process of peg penetration: developmental arrest caused by pod (Pattee 3 pods) excavation. Bagging the aerial pods was used to simulate loss of mechanical pressure, while direct exposure of the aerial pods was used to simulate loss of both mechanical pressure and darkness. After the loss of mechanical stress and darkness, the DEGs were significantly enriched in photosynthesis, photosynthesis–antenna proteins, plant–pathogen interaction, DNA replication, and circadian rhythm pathways. The DNA replication pathway was enriched by down-regulated genes, and the other four pathways were enriched by upregulated genes. Upregulated genes were also significantly enriched in protein ubiquitination and calmodulin-related genes, highlighting the important role of ubiquitination and calcium signaling in pod development. Further analysis of DEGs showed that phytochrome A (Phy A), auxin response factor 9 (IAA9), and mechanosensitive ion channel protein played important roles in geocarpy. The expression of these two genes increased in subterranean pods but decreased in aerial pods. Based on a large number of chloroplast-related genes, calmodulin, kinases, and ubiquitin-related proteins identified in this study, we propose two possible signal transduction pathways involved in peanut geocarpy, namely, one begins in chloroplasts and signals down through phosphorylation, and the other begins during abiotic stress and signals down through calcium signaling, phosphorylation, and ubiquitination. Our study provides valuable information about putative regulatory genes for peanut pod development and contributes to a better understanding of the biological phenomenon of geocarpy.

Congenital Long QT Syndrome: A Review of Genetic and Pathophysiologic Etiologies, Phenotypic Subtypes, and Clinical Management.

Congenital Long QT Syndrome (CLQTS) is the most common inherited arrhythmia. The QT interval, which marks the duration of ventricular depolarization and repolarization in the myocardium, can be prolonged due to mutations in genes coding for the ion channel proteins that govern the cardiac action potential. The lengthening of the QT interval can lead to a wide range of clinical symptoms, including seizures, torsades de pointes, and fatal arrhythmias. There is a growing body of evidence that has revealed the genetic mutations responsible for the pathophysiology of CLQTS, and this has led to hypotheses regarding unique triggers and clinical features associated with specific gene mutations. Epidemiologic evidence has revealed a 1-year mortality rate of approximately 20% in untreated CLQTS patients, and a <1% of 1-year mortality rate in treated patients, underscoring the importance of timely diagnosis and effective clinical management. There are many phenotypic syndromes that constitute CLQTS, including but not limited to, Jervell and Lange-Nielsen syndrome, Romano and Ward syndrome, Andersen-Tawil syndrome, and Timothy syndrome. In this review, we aim to (1) summarize the genetic, epidemiologic, and pathophysiological basis of CLQTS and (2) outline the unique features of the phenotypic subtypes and their clinical management.

Potassium Binding Interactions with Aliphatic Amino Acids: Thermodynamic and Entropic Effects Analyzed via a Guided Ion Beam and Computational Study.

Noncovalent interactions between alkali metals and amino acids are critical for many biological processes, especially for proper function of protein ion channels; however, many precise binding affinities between alkali metals and amino acids still need to be measured. This study addresses this need by using threshold collision-induced dissociation with a guided ion beam tandem mass spectrometer to measure binding affinities between potassium cations and the aliphatic amino acids: Gly, Ala, hAla, Val, Leu, and Ile. These measurements are supplemented by theoretical calculations and include commentary on effects of enthalpy, entropy, and structural preference. Notably, all levels of theory indicate that the lowest-lying isomers at 298 K have K+ binding to the carbonyl oxygen in either a monodentate ([CO]) or bidentate ([CO,OH]) fashion, isomers that are linked in a double-well potential. This complicates the analysis of the data, although does not greatly influence the final results. Analysis of the resulting cross sections includes accounting for multiple ion-molecule collisions, internal energy of reactant ions, and unimolecular decay rates. The resulting experimental bond dissociation energies generally increase as the polarizability of the amino acid increases, results that agree well with quantum chemical calculations done at the B3LYP, B3P86, and MP2(full) levels of theory, with B3LYP-GD3BJ predicting systematically larger values.