Long QT syndrome (LQTS) is a genetic disease characterized by a prolonged QT interval in an electrocardiogram (ECG), leading to higher risk of sudden cardiac death. Among the 12 identified genes causal to heritable LQTS, ∼90% of affected individuals harbor mutations in either KCNQ1 or human ether-a-go-go related genes (hERG), which encode two repolarizing potassium currents known as I Ks and I Kr . The ability to quantitatively assess contributions of different current components is therefore important for investigating disease phenotypes and testing effectiveness of pharmacological modulation. Here we report a quantitative analysis by simulating cardiac action potentials of cultured human cardiomyocytes to match the experimental waveforms of both healthy control and LQT syndrome type 1 (LQT1) action potentials. The quantitative evaluation suggests that elevation of I Kr by reducing voltage sensitivity of inactivation, not via slowing of deactivation, could more effectively restore normal QT duration if I Ks is reduced. Using a unique specific chemical activator for I Kr that has a primary effect of causing a right shift of V 1/2 for inactivation, we then examined the duration changes of autonomous action potentials from differentiated human cardiomyocytes. Indeed, this activator causes dose-dependent shortening of the action potential durations and is able to normalize action potentials of cells of patients with LQT1. In contrast, an I Kr chemical activator of primary effects in slowing channel deactivation was not effective in modulating action potential durations. Our studies provide both the theoretical basis and experimental support for compensatory normalization of action potential duration by a pharmacological agent.
Purpose: We previously reported that activated T cells accumulate in the perihematomal regions after Intracerebral hemorrhage (ICH) and aggravate hemorrhagic brain injury. However, brain-infiltrating T cells precise activation mechanisms and resulting pathological impacts remain largely unexplored. This study aims to address these knowledge gaps. Methodology: ICH was induced via standard collagenase injection in male C57BL/6J mice (10 weeks old). Activation pathways of T cells were analyzed through single-cell RNA data (GSE230414). We assessed T cell receptor (TCR) activation, pro-inflammatory cytokines expression, and immune cell infiltration via flow cytometry and immunostaining at 1- and 3-days post-ICH. Neurobehavioral evaluations were conducted at 1-, 3-, 7-, and 14-days post-ICH. TCR activation was pharmacologically inhibited using the TCR-specific inhibitor AX-024, administered (10 mg/kg, i.p.) one hour after ICH. Results: Single-cell transcriptomic analysis revealed an upregulation of the TCR pathway in activated T cells following ICH in mice. Flow cytometry and immunostaining validated TCR activation markers (p-CD3, p-Zap70) in ICH mouse models. These findings suggest that TCR activation likely plays a central role in the activation of brain-infiltrating T cells. In the subsequent experiment, we explored the pathological implications of TCR activation on T cell activation, leukocyte brain infiltration, and neurological outcomes post-ICH. We found that administration of AX-024 substantially inhibited TCR activation (CD69 expression) and expression of pro-inflammatory cytokines (IL-17, IL-1β) in brain-infiltrating T cells at 1- and 3-days post-ICH. Notably, AX-024 administration also significantly decreased the infiltration of other leukocytes and remarkably enhanced long-term sensorimotor and cognitive function up to 14 days after ICH. Discussion: This study underscores TCR activation as a pivotal mechanism driving activation of brain-infiltrating T cells following ICH. Inhibiting TCR activation through AX-024 proves beneficial for improving neurological outcomes after ICH. However, further investigations are warranted to comprehensively elucidate the intricate underlying pathological mechanisms.
Background Low-density lipoprotein receptor-related protein 1 (LRP1) is a multifunctional receptor involved in receptor-mediated endocytosis and cell signaling. The aim of this study was to elucidate the expression and mechanism of LRP1 in hepatocellular carcinoma (HCC). Methods LRP1 expression in 4 HCC cell lines and 40 HCC samples was detected. After interruption of LRP1 expression in a HCC cell line either with specific lentiviral-mediated shRNA LRP1 or in the presence of the LRP1-specific chaperone, receptor-associated protein (RAP), the role of LRP1 in the migration and invasion of HCC cells was assessed in vivo and in vitro, and the expression of matrix metalloproteinase (MMP) 9 in cells and the bioactivity of MMP9 in the supernatant were assayed. The expression and prognostic value of LRP1 were investigated in 327 HCC specimens. Results Low LRP1 expression was associated with poor HCC prognosis, with low expression independently related to shortened overall survival and increased tumor recurrence rate. Expression of LRP1 in non-recurrent HCC samples was significantly higher than that in early recurrent samples. LRP1 expression in HCC cell lines was inversely correlated with their metastatic potential. After inhibition of LRP1, low-metastatic SMCC-7721 cells showed enhanced migration and invasion and increased expression and bioactivity of MMP9. Correlation analysis showed a negative correlation between LRP1 and MMP9 expression in HCC patients. The prognostic value of LRP1 expression was validated in the independent data set. Conclusions LRP1 modulated the level of MMP9 and low level of LRP1 expression was associated with aggressiveness and invasiveness in HCCs. LRP1 offered a possible strategy for tumor molecular therapy.
Abstract To determine whether positive or negative DWI TIA patients could get benefits from HST we conducted a cohort study which data from the prospective, hospital-based, TIA database of the First Affiliated Hospital of Zhengzhou University. The end-point was 7-day and 90-day incidence of stroke. Cox proportional hazard regression models were used to analyze the association between end-points and high-intensity statin treatment in TIA patients with positive and negative DWI. A total of 987 eligible TIA patients were analyzed. The stroke risk of patients with positive DWI was about a four-fold increase compared to that with negative DWI (7 d, 10.9 versus 1.8, p < 0.001 and 90 d, 18.3 versus 4.2, p < 0.001). After adjusting confounding factors, HST significantly improved both 7-day (HR 0.331, 95% CI 0.165–0.663; p = 0.002) and 90-day (HR 0.480, 95% CI 0.288–0.799; p = 0.005) outcomes in positive DWI patients. As a conclusion, high-intensity statin use reduces the 90 days’ recurrent stroke risk in DWI-positive TIA patients but not in DWI-negative patients.
Polymorphs of ZnHPO3·2H2O with both centrosymmetry (Cmcm) and noncentrosymmetry (C2) structures were successfully prepared by modified solution evaporation and seed-crystals induced secondary nucleation methods. In Cmcm-ZnHPO3·2H2O, the zinc atoms are only octahedrally coordinated, while in C2-ZnHPO3·2H2O, they feature both tetrahedral and octahedral coordination. As a result, Cmcm-ZnHPO3·2H2O features a 2D layered structure with lattice water molecules located in the interlayer space, while C2-ZnHPO3·2H2O features a 3D electroneutral framework of tfa topology connected by Zn(1)O4, Zn(2)O6 and HPO3 units. The UV-Visible diffuse-reflectance spectra associated with Tauc’s analyses give a direct bandgap of 4.24 and 4.33 eV for Cmcm-ZnHPO3·2H2O and C2-ZnHPO3·2H2O, respectively. Moreover, C2-ZnHPO3·2H2O exhibits a week second harmonic generation (SHG) response and a moderate birefringence for phase matching, indicating its potential as a nonlinear optical material. Detailed dipole moment calculation and analysis confirmed that the SHG response mainly derived from the HPO3 pseudo-tetrahedra.
An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
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