Methods of prolonging the effect of caudal block in children.

Caudal epidural blockade is one of the most frequently administered regional anesthesia techniques in children. It is a supplement during general anesthesia and for providing postoperative analgesia in pediatrics for sub-umbilical surgeries, especially for genitourinary surgeries. However, the duration of the analgesic effect is occasionally unsatisfactory. In this review, we discuss the main advantages and disadvantages of different techniques to prolong postoperative analgesia for single-injection caudal blockade in children. A literature search of the keywords "caudal", "analgesia", "pediatric", and "children" was performed using PubMed and Web of Science databases. We highlight that analgesic quality correlates substantially with the local anesthetic's type, dose, the timing relationship between caudal block and surgery, caudal catheterization, and administration of epidural opioids or other adjuvant drugs.

Folate as a potential treatment for lethal ventricular arrhythmias in TANGO2-deficiency disorder.

TANGO2-deficiency disorder (TDD) is an autosomal-recessive genetic disease caused by biallelic loss-of-function variants in the TANGO2 gene. TDD-associated cardiac arrhythmias are recalcitrant to standard antiarrhythmic medications and constitute the leading cause of death. Disease modeling for TDD has been primarily carried out using human dermal fibroblast and, more recently, in Drosophila by multiple research groups. No human cardiomyocyte system has been reported, which greatly hinders the investigation and understanding of TDD-associated arrhythmias. Here, we established potentially novel patient-derived induced pluripotent stem cell differentiated cardiomyocyte (iPSC-CM) models that recapitulate key electrophysiological abnormalities in TDD. These electrophysiological abnormalities were rescued in iPSC-CMs with either adenoviral expression of WT-TANGO2 or correction of the pathogenic variant using CRISPR editing. Our natural history study in patients with TDD suggests that the intake of multivitamin/B complex greatly diminished the risk of cardiac crises in patients with TDD. In agreement with the clinical findings, we demonstrated that high-dose folate (vitamin B9) virtually abolishes arrhythmias in TDD iPSC-CMs and that folate's effect was blocked by the dihydrofolate reductase inhibitor methotrexate, supporting the need for intracellular folate to mediate antiarrhythmic effects. In summary, data from TDD iPSC-CM models together with clinical observations support the use of B vitamins to mitigate cardiac crises in patients with TDD, providing potentially life-saving treatment strategies during life-threatening events.

Efficacy and action mechanisms of compound Shen Chan decoction on experimental models of atopic dermatitis.

Shen chan decoction (SCD) as a significant Traditional Chinese medicine (TCM) to treat atopic dermatitis (AD), but its mechanism of action has not been clarified, so we started the present study, first possible effects of SCD on AD were predicted using network pharmacology. Next, dinitrochlorobenzene was used to establish a mouse model of AD. After successful modelling, the SCD were administered intragastrically to treat the mice. Eventually, the KEGG pathway enrichment analysis indicated that SCD improved AD mainly through effects on inflammation and the gut microbiota. The experimental findings revealed that SCD treatment attenuated AD symptoms and downregulate the characteristic immune factors, namely IL-4, IL-6 and IgE. Moreover, it promoted a balance between Th1/Th2 cells. Furthermore, the itch signaling pathways involving H1R/PAR-2/TRPV1 were inhibited. The 16S rRNA sequencing results indicated that SCD administration influenced the Firmicutes/Bacteroidetes ratio at the phylum level by augmenting the relative proportions of Lactobacillaceae and Muribaculaceae at the family and genus levels, while decreasing the abundances of Lactococcus and Ruminococcus. These findings suggest that internal administration of SCD is an effective therapeutic approach for AD. We suggest that SCD may be an alternative therapy for the treatment of AD.Additionally, it could offer valuable insights into the pathogenesis of AD and the development of innovative therapeutic agents.

Efficient gene delivery by multifunctional star poly (ß-amino ester)s into difficult-to-transfect macrophages for M1 polarization.

Gene delivery to macrophages holds great promise for cancer immunotherapy. However, traditional gene delivery methods exhibit low transfection efficiency in macrophages. The star-shaped topological structure of polymers is known to encapsulate genes inside their cores, thereby facilitating sustained release of the genetic material. Herein, combining the structural advantages of star polymers and the transfection advantages of poly (ß-amino ester)s (PAEs), we developed a novel linear oligomer grafting-onto strategy to synthesize a library of multi-terminal star structured PAEs (SPAEs), and evaluated their gene delivery efficiency in various tissue cells. The transfection with human hepatocellular carcinoma cells (HepG2, HCC-LM3 cells and MHCC-97H cells), rat normal liver cells (BRL-3 A cells), human ovarian cancer cells (A2780 cells), African green monkey kidney cells (Vero cells), human cervical cancer cells (HeLa cells), human chondrosarcoma cells (SW1353 cells), and difficult-to-transfect human epidermal keratinocytes (HaCaT cells) and normal human fibroblast cells (NHF cells) showed that SPAEs exhibited superior transfection profile. The GFP transfection efficiency of top-performing SPAEs in HeLa cells (96.1%) was 2.1-fold, and 3.2-fold higher compared to jetPEI and Lipo3000, respectively, indicating that the star-shaped topological structure can significantly enhance the transfection efficiency of PAEs. More importantly, the top-performing SPAEs could efficiently deliver Nod2 DNA to difficult-to-transfect RAW264.7 macrophages, with a high transfection efficiency of 33.9%, which could promote macrophage M1 polarization and enhanced CD8+ T cell response in co-incubation experiments. This work advances gene therapy by targeting difficult-to-transfect macrophages and remodeling the tumor immune microenvironment.

Serum metabolism characteristics of patients with myocardial injury after noncardiac surgery explored by the untargeted metabolomics approach.

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) is one of the most common complications associated with postoperative adverse cardiovascular outcomes and mortality. However, MINS often fails to be timely diagnosed due to the absence of clinical symptoms and limited diagnostic methods. The metabolomic analysis might be an efficient way to discover new biomarkers of MINS. Characterizing the metabolomic features of MINS patients may provide new insight into the diagnosis of MINS. METHODS: In this study, serum samples from 20 matched patients with or without MINS (n = 10 per group) were subjected to untargeted metabolomics analysis to investigate comprehensive metabolic information. Differential metabolites were identified, and the enriched metabolic pathway was determined based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. RESULTS: A comprehensive analysis revealed 124 distinct metabolites, predominantly encompassing lipids, amino acids and other compounds. The observed modifications in metabolic pathways in patients with or without MINS showed significant clustering in cholesterol metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis, as well as cysteine and methionine metabolism. Four specific metabolites (taurocholic acid, L-pyroglutamic acid, taurochenodeoxycholic acid, and pyridoxamine) exhibited promising potential as biomarkers for prognosticating MINS. CONCLUSIONS: This study contributes valuable insights into the metabolomic features of MINS and the discovery of potential biomarkers which may help the early diagnosis of MINS. The identified metabolites and altered pathways offer valuable insights into the molecular underpinnings of MINS, paving the way for improved diagnostic approaches and potential intervention strategies.

Hic-5 regulates extracellular matrix-associated gene expression and cytokine secretion in cancer associated fibroblasts.

The focal adhesion protein, Hic-5 plays a key role in promoting extracellular matrix deposition and remodeling by cancer associated fibroblasts within the tumor stroma to promote breast tumor cell invasion. However, whether stromal matrix gene expression is regulated by Hic-5 is still unknown. Utilizing a constitutive Hic-5 knockout, Mouse Mammary Tumor Virus-Polyoma Middle T-Antigen spontaneous breast tumor mouse model, bulk RNAseq analysis was performed on cancer associated fibroblasts isolated from Hic-5 knockout mammary tumors. Functional network analysis highlighted a key role for Hic-5 in extracellular matrix organization, with both structural matrix genes, as well as matrix remodeling genes being differentially expressed in relation to Hic-5 expression. The subcellular distribution of the MRTF-A transcription factor and expression of a subset of MRTF-A responsive genes was also impacted by Hic-5 expression. Additionally, cytokine array analysis of conditioned media from the Hic-5 and Hic-5 knockout cancer associated fibroblasts revealed that Hic-5 is important for the secretion of several key factors that are associated with matrix remodeling, angiogenesis and immune evasion. Together, these data provide further evidence of a central role for Hic-5 expression in cancer associated fibroblasts in regulating the composition and organization of the tumor stroma microenvironment to promote breast tumor progression.

Novel Pan-ERR Agonists Ameliorate Heart Failure Through Enhancing Cardiac Fatty Acid Metabolism and Mitochondrial Function.

BACKGROUND: Cardiac metabolic dysfunction is a hallmark of heart failure (HF). Estrogen-related receptors ERRα and ERRγ are essential regulators of cardiac metabolism. Therefore, activation of ERR could be a potential therapeutic intervention for HF. However, in vivo studies demonstrating the potential usefulness of ERR agonist for HF treatment are lacking, because compounds with pharmacokinetics appropriate for in vivo use have not been available. METHODS: Using a structure-based design approach, we designed and synthesized 2 structurally distinct pan-ERR agonists, SLU-PP-332 and SLU-PP-915. We investigated the effect of ERR agonist on cardiac function in a pressure overload-induced HF model in vivo. We conducted comprehensive functional, multi-omics (RNA sequencing and metabolomics studies), and genetic dependency studies both in vivo and in vitro to dissect the molecular mechanism, ERR isoform dependency, and target specificity. RESULTS: Both SLU-PP-332 and SLU-PP-915 significantly improved ejection fraction, ameliorated fibrosis, and increased survival associated with pressure overload-induced HF without affecting cardiac hypertrophy. A broad spectrum of metabolic genes was transcriptionally activated by ERR agonists, particularly genes involved in fatty acid metabolism and mitochondrial function. Metabolomics analysis showed substantial normalization of metabolic profiles in fatty acid/lipid and tricarboxylic acid/oxidative phosphorylation metabolites in the mouse heart with 6-week pressure overload. ERR agonists increase mitochondria oxidative capacity and fatty acid use in vitro and in vivo. Using both in vitro and in vivo genetic dependency experiments, we show that ERRγ is the main mediator of ERR agonism-induced transcriptional regulation and cardioprotection and definitively demonstrated target specificity. ERR agonism also led to downregulation of cell cycle and development pathways, which was partially mediated by E2F1 in cardiomyocytes. CONCLUSIONS: ERR agonists maintain oxidative metabolism, which confers cardiac protection against pressure overload-induced HF in vivo. Our results provide direct pharmacologic evidence supporting the further development of ERR agonists as novel HF therapeutics.

Superior TRAIL gene expression and cancer cell apoptosis mediated by highly branched-linear poly(ß-amino ester)s.

Extensive efforts have been dedicated to enhancing the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in cancer cells for the development of effective cancer treatments. However, highly safe and efficient delivery of TRAIL gene remains a significant challenge, especially using cationic polymers. Here, a series of highly branched-linear poly(ß-amino ester)s (H-LPAEs) are developed through a unique oligomer branching strategy. H-LPAEs exhibit a more uniform distribution of linear segments and branching units, leading to excellent DNA condensation and favorable physicochemical properties of H-LPAE/DNA polyplexes. In SW1353 and BMSC cells, the optimized H-LPAEs, H-LPAEB4-S5-TMPTA, achieves superior gene transfection efficiency of 58.0% and 33.4%, which were 2.5-fold and 2.0-fold higher than that of the leading commercial gene transfection reagent, Lipofectamine 3000. Excitingly, H-LPAEB4-S5-TMPTA mediated 56.7% and 28.1% cell apoptosis in HepG2 cells and HeLa cells highlighting its potential application in cancer gene therapy. In addition, locally administered H-LPAEB4-S5-TMPTA delivered TRAIL DNA to HepG2 xenograft tumors and inhibited tumor growth in vivo. This study not only proposes a novel strategy for synthesizing poly(ß-amino ester)s with a unique branched-linear topology but also identifies a promising candidate for highly efficient TRAIL gene transfection.

Multifunctional CaCO3@Cur@QTX125@HA nanoparticles for effectively inhibiting growth of colorectal cancer cells.

Colorectal cancer (CRC) is a major cause of cancer-related deaths in humans, and effective treatments are still needed in clinical practice. Despite significant developments in anticancer drugs and inhibitors, their poor stability, water solubility, and cellular membrane permeability limit their therapeutic efficacy. To address these issues, multifunctional CaCO3 nanoparticles loaded with Curcumin (Cur) and protein deacetylase (HDAC) inhibitor QTX125, and coated with hyaluronic acid (HA) (CaCO3@Cur@QTX125@HA), were prepared through a one-step gas diffusion strategy. Dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) showed that CaCO3@Cur@QTX125@HA nanoparticles have uniform spherical morphology and elemental distribution, with diameters around 450 nm and a Zeta potential of - 8.11 mV. The controlled release of Cur from the nanoparticles was observed over time periods of 48 h. Cellular uptake showed that CaCO3@Cur@QTX125@HA nanoparticles were efficiently taken up by cancer cells and significantly inhibited their growth. Importantly, CaCO3@Cur@QTX125@HA nanoparticles showed specific inhibitory effects on CRC cell growth. Encouragingly, CaCO3@Cur@QTX125@HA nanoparticles successfully internalized into CRC patient-derived organoid (PDO) models and induced apoptosis of tumor cells. The multifunctional CaCO3@Cur@QTX125@HA nanoparticles hold promise for the treatment of CRC.

The Structural Evolution of ß-to-α Phase Transition in the Annealing Process of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate).

In this study, the structural and property changes induced in the highly ordered structure of preoriented poly(3-hydroxybutyrate-co-3-hydroxyvalerate) PHBV films containing the ß-form during annealing were investigated. The transformation of the ß-form was investigated by means of in situ wide-angle X-ray diffraction (WAXD) using synchrotron X-rays. The comparison of PHBV films with the ß-form before and after annealing was performed using small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The evolution mechanism of ß-crystal transformation was elucidated. It was revealed that most of the highly oriented ß-form directly transforms into the highly oriented α-form, and there might be two kinds of transformations: (1) The ß-crystalline bundles may be transformed one by one rather than one part by one part during annealing before a certain annealing time. (2) The ß-crystalline bundles crack or the molecular chains of the ß-form are separated from the lateral side after annealing after a certain annealing time. A model to describe the microstructural evolution of the ordered structure during annealing was established based on the results obtained.

Synthetic ERRα/ß/γ Agonist Induces an ERRα-Dependent Acute Aerobic Exercise Response and Enhances Exercise Capacity.

Repetitive physical exercise induces physiological adaptations in skeletal muscle that improves exercise performance and is effective for the prevention and treatment of several diseases. Genetic evidence indicates that the orphan nuclear receptors estrogen receptor-related receptors (ERRs) play an important role in skeletal muscle exercise capacity. Three ERR subtypes exist (ERRα, ß, and γ), and although ERRß/γ agonists have been designed, there have been significant difficulties in designing compounds with ERRα agonist activity. Additionally, there are limited synthetic agonists that can be used to target ERRs in vivo. Here, we report the identification of a synthetic ERR pan agonist, SLU-PP-332, that targets all three ERRs but has the highest potency for ERRα. Additionally, SLU-PP-332 has sufficient pharmacokinetic properties to be used as an in vivo chemical tool. SLU-PP-332 increases mitochondrial function and cellular respiration in a skeletal muscle cell line. When administered to mice, SLU-PP-332 increased the type IIa oxidative skeletal muscle fibers and enhanced exercise endurance. We also observed that SLU-PP-332 induced an ERRα-specific acute aerobic exercise genetic program, and the ERRα activation was critical for enhancing exercise endurance in mice. These data indicate the feasibility of targeting ERRα for the development of compounds that act as exercise mimetics that may be effective in the treatment of numerous metabolic disorders and to improve muscle function in the aging.

In-situ preparation of yeast-supported Fe0@Fe2O3 as peroxymonosulfate activator for enhanced degradation of tetracycline hydrochloride.

Nano zero-valent iron (nZVI) is extensively used as a peroxymonosulfate (PMS) activator but suffers from the ease of oxidation and agglomeration due to its high surface energy and inherent magnetism. Here, green and sustainable yeast was selected as a support material to firstly in-situ prepare yeast-supported Fe0@Fe2O3 and used for activating PMS to degrade tetracycline hydrochloride (TCH), one of the common antibiotics. Due to the anti-oxidation ability of the Fe2O3 shell and the support effect of yeast, the prepared Fe0@Fe2O3/YC exhibited a superior catalytic activity for the removal of TCH as well as some other typical refractory contaminants. The chemical quenching experiments and EPR results demonstrated SO4•- was the main reactive oxygen species while O2•-, 1O2 and •OH played a minor role. Importantly, the crucial role of the Fe2+/Fe3+ cycle promoted by the Fe0 core and surface iron hydroxyl species in PMS activation was elucidated in detail. The TCH degradation pathways were proposed by LC-MS and density functional theory (DFT) calculation. In addition, the outstanding magnetic separation property, anti-oxidation ability, and high environmental resistance of the catalyst were demonstrated. Our work may inspire the development of green, efficient, and robust nZVI-based materials for wastewater treatment.

Assigning pathogenicity for TAB2 variants using a novel scalable functional assay and expanding TAB2 disease spectrum.

Haploinsufficiency of TGF-beta-activated kinase 1 (MAP3K7) binding protein 2 (TAB2) has been associated with congenital heart disease and more recently multiorgan structural abnormalities. Missense variant represents a major proportion of non-synonymous TAB2 variants reported in gnomAD (295/576) and Clinvar (16/73), most of which are variants of uncertain significance (VUSs). However, interpretation of TAB2 missense variants remains challenging because of lack of functional assays. To address this issue, we established a cell-based luciferase assay that enables high-throughput screening of TAB2 variants to assess the functional consequence for predicting variant pathogenicity. Using this platform, we screened 47 TAB2 variants including five pathogenic controls and one benign control, and the results showed that the transcriptional activity of activator protein 1 (AP-1) but not nuclear factor kappa B predicts the TAB2 variant pathogenicity. This assay provides accurate functional readout for both loss-of-function (LOF) and gain-of-function variants, which are associated with distinct phenotypes. In all, 22 out of 32 tested VUSs were reclassified. Genotype-Phenotype association showed that most patients with partial LOF variants do not exhibit congenital heart disease but high frequency of developmental delay, hypotonia and dysmorphic features, which suggests that genetic testing for TAB2 is needed for a broader spectrum of patients with more diverse phenotypes. Molecular modeling with Npl4 zinc finger (NZF) domain variants revealed that the stability of the NZF domain in TAB2 protein is crucial for AP-1 activation. In conclusion, we developed a highly effective functional assay for TAB2 variant prediction and interpretation.

REV-ERB is essential in cardiac fibroblasts homeostasis.

REV-ERB agonists have shown antifibrotic effects in the heart and other organs. The function of REV-ERB in the cardiac fibroblasts remains unstudied. Here, we characterize the functional difference of REV-ERB in mouse embryonic fibroblasts and cardiac fibroblasts using genetic deletion of REV-ERBα and ß in vitro. We show that REV-ERB α/ß double deleted cardiac fibroblasts have reduced viability and proliferation, but increased migration and myofibroblasts activation. Thus, REV-ERB α/ß has essential cell-autonomous role in cardiac fibroblasts in maintaining them in a healthy, quiescent state. We also show that existing REV-ERB agonist SR9009 strongly suppresses cardiac fibroblasts activation but in a REV-ERB-independent manner highlighting the need to develop novel REV-ERB agonists for treating cardiac fibrosis.

High-Efficiency CO2 /N2 Separation Enabled by Rotation of Electrostatically Anchored Flexible Ligands in Metal-Organic Framework.

Metal organic frameworks (MOF) are of great potential for molecular separation, but the ligand rotation flexibility makes them remain challenging in the construction of fixed nanochannels for precise sieving. Here we report an electrostatic-anchoring strategy to fix the rotation of 2-methylimidazole (2-MIM) ligand in ZIF-8. Electrostatic inducer trifluoroacetate anchored at and blocked the six-membered windows of ZIF-8, and meanwhile induced the positive 2-MIM rotated from initial 49° to 68°, thus opening neighbored four-membered windows with a constant size of 3.4 Å. The obtained ZIF-8 significantly enhanced the CO2 /N2 adsorption selectivity from 14.02 to 332.86. Further membrane-based separation exhibited an outstanding CO2 /N2 selectivity of up to 137 with a desired permeability of 286 Barrer, which exceeded the 2019 upper bound. This strategy provides a new inspiration for fixing the ligand rotation in soft MOF for desired precise molecular sieving.

A strategy for quality control of ginkgo biloba preparations based on UPLC fingerprint analysis and multi-component separation combined with quantitative analysis.

BACKGROUND: Many studies have assessed the fingerprint and quantitative analysis of Ginkgo biloba preparations, but the fingerprint mainly focuses on flavonoid glycosides. However, according to our previous study, the differences among diverse manufacturers mainly involve organic acids. METHODS: A novel reverse-phase liquid chromatography assay using diode array detection was developed for evaluating Ginkgo biloba preparations for quality based on a chromatographic fingerprint allowing the simultaneous assessment of eleven compounds, including four organic acids, six flavonol glycosides and one flavonoid aglycone. And the method was applied to 51 batches of Ginkgo biloba preparations from manufacturers in China. Chemometric approaches were performed for evaluating 51 batches of Ginkgo biloba preparations from various manufacturers. RESULTS: The similarity values among the chromatograms of 51 samples ranged from 0.45 to 1.00, showing that the quality of Ginkgo biloba preparations produced by different manufacturers varied greatly. Data analysis of the 51 batches of GBP samples suggested significant variations of the total contents of all 11 targets, also demonstrating the quality difference of GBP samples. There were significant differences in organic acids in particular. CONCLUSION: Combining the chemical fingerprint and quantitative assessment revealed significant variations in the examined commercial products with regard to organic acids. Thus, this study provided a more comprehensive tool for monitoring the quality consistency of Ginkgo biloba preparations.

Electrostatic-Induced Crystal-Rearrangement of Porous Organic Cage Membrane for CO2 Capture.

Porous Organic Cages (POCs) with tunable tailoring chemistry properties and polymer-like processing conditions are of great potential for molecular selective membranes, but it remains challenging in the assembly of high crystalline POCs with regular nanochannels for effective molecular sieving. Here we report an electrostatic-induced crystal-rearrangement strategy for the design of a POC membrane with heterostructure. Due to electrostatic attraction, ionic liquid molecules induced cage molecules to rearrange into a sub-10 nm uniform and defect-free crystal layer, which displayed competitive CO2 separation performance. The optimized hetero-structured membrane exhibited an attractive CO2 /N2 separation selectivity of over 130, which was superior to the state-of-the-art membranes, accompanied with excellent long-term and thermal shock stability. This strategy provides a new inspiration for the preparation of crystal-rearranged membranes with regular channels for gas molecule sieving.

Cardiac crises: Cardiac arrhythmias and cardiomyopathy during TANGO2 deficiency related metabolic crises.

BACKGROUND: TANGO2 deficiency disorder (TDD) is an autosomal recessive disease associated with metabolic crisis, lethal cardiac arrhythmias, and cardiomyopathy. Data regarding treatment, management, and outcomes of cardiac manifestations of TDD are lacking. OBJECTIVE: The purpose of this study was to describe TDD-related cardiac crises. METHODS: Retrospective multicenter chart review was made of TDD patients admitted with cardiac crises, defined as development of ventricular tachycardia (VT), cardiomyopathy, or cardiac arrest during metabolic crises. RESULTS: Twenty-seven children were admitted for 43 cardiac crises (median age 6.4 years; interquartile range [IQR] 2.4-9.8 years) at 14 centers. During crisis, QTc prolongation occurred in all (median 547 ms; IQR 504-600 ms) and a type I Brugada pattern in 8 (26%). Arrhythmias included VT in 21 (78%), supraventricular tachycardia in 3 (11%), and heart block in 1 (4%). Nineteen patients (70%) developed cardiomyopathy, and 20 (74%) experienced a cardiac arrest. There were 10 deaths (37%), 6 related to arrhythmias. In 5 patients, recalcitrant VT occurred despite use of antiarrhythmic drugs. In 6 patients, arrhythmias were controlled after extracorporeal membrane oxygenation (ECMO) support; 5 of these patients survived. Among 10 patients who survived VT without ECMO, successful treatment included intravenous magnesium, isoproterenol, and atrial pacing in multiple cases and verapamil in 1 patient. Initiation of feeds seemed to decrease VT events. CONCLUSION: TDD-related cardiac crises are associated with a high risk of arrhythmias, cardiomyopathy, cardiac arrest, and death. Although further studies are needed, early recognition and appropriate treatment are critical. Acutely, intravenous magnesium, isoproterenol, atrial pacing, and ECMO as a last resort seem to be the best current treatment options, and early initiation of feeds may prevent VT events.

Paxillin promotes breast tumor collective cell invasion through maintenance of adherens junction integrity.

Distant organ metastasis is linked to poor prognosis during cancer progression. The expression level of the focal adhesion adapter protein paxillin varies among different human cancers, but its role in tumor progression is unclear. Herein we utilize a newly generated PyMT mammary tumor mouse model with conditional paxillin ablation in breast tumor epithelial cells, combined with in vitro three-dimensional (3D) tumor organoids invasion analysis and 2D calcium switch assays, to assess the roles for paxillin in breast tumor cell invasion. Paxillin had little effect on primary tumor initiation and growth but is critical for the formation of distant lung metastasis. In paxillin-depleted 3D tumor organoids, collective cell invasion was substantially perturbed. The 2D cell culture revealed paxillin-dependent stabilization of adherens junctions (AJ). Mechanistically, paxillin is required for AJ assembly through facilitating E-cadherin endocytosis and recycling and HDAC6-mediated microtubule acetylation. Furthermore, Rho GTPase activity analysis and rescue experiments with a RhoA activator or Rac1 inhibitor suggest paxillin is potentially regulating the E-cadherin-dependent junction integrity and contractility through control of the balance of RhoA and Rac1 activities. Together, these data highlight new roles for paxillin in the regulation of cell-cell adhesion and collective tumor cell migration to promote the formation of distance organ metastases.

KLF15 Regulates Oxidative Stress Response in Cardiomyocytes through NAD.

KLF15 has recently emerged as a central regulator of metabolism. Although its connection to oxidative stress has been suspected, there has not been any study to date that directly demonstrates the molecular link. In this study, we sought to determine the role of KLF15 in cardiac oxidative stress. We found that KLF15 deficiency in the heart is associated with increased oxidative stress. Acute deficiency of KLF15 in neonatal rat ventricular myocytes (NRVMs) leads to the defective clearance of reactive oxygen species (ROS) and an exaggerated cell death following a variety of oxidative stresses. Mechanistically, we found that KLF15 deficiency leads to reduced amounts of the rate-limiting NAD+ salvage enzyme NAMPT and to NAD+ deficiency. The resultant SIRT3-dependent hyperacetylation and the inactivation of mitochondrial antioxidants can be rescued by MnSOD mimetics or NAD+ precursors. Collectively, these findings suggest that KLF15 regulates cardiac ROS clearance through the regulation of NAD+ levels. Our findings establish KLF15 as a central coordinator of cardiac metabolism and ROS clearance.