Site-Selective Synthesis and Concurrent Immobilization of Imine-Based Covalent Organic Frameworks on Electrodes Using an Electrogenerated Acid.

Imine-based covalent organic frameworks (COFs) are crystalline porous materials with prospective uses in various devices. However, general bulk synthetic methods usually produce COFs as powders that are insoluble in most of the common organic solvents, arising challenges for the subsequent molding and fixing of these materials on substrates. Here, we report a novel synthetic methodology that utilizes an electrogenerated acid (EGA), which is produced at an electrode surface by electrochemical oxidation of a suitable precursor, acting as an effective Brønsted acid catalyst for imine bond formation from the corresponding amine and aldehyde monomers. Simultaneously, it provides the corresponding COF film deposited on the electrode surface. The COF structures obtained with this method exhibited high crystallinities and porosities, and the film thickness could be controlled. Furthermore, such process was applied for the synthesis of various imine-based COFs, including a three-dimensional (3D) COF structure.

Single Particle Analysis of H3N2 Influenza Entry Differentiates the Impact of the Sialic Acids (Neu5Ac and Neu5Gc) on Virus Binding and Membrane Fusion.

Entry of influenza A viruses (IAVs) into host cells is initiated by binding to sialic acids (Sias), their primary host cell receptor, followed by endocytosis and membrane fusion to release the viral genome into the cytoplasm of the host cell. Host tropism is affected by these entry processes, with a primary factor being receptor specificity. Sias exist in several different chemical forms, including the hydroxylated N-glycolylneuraminic acid (Neu5Gc), which is found in many hosts; however, it has not been clear how modified Sias affect viral binding and entry. Neu5Gc is commonly found in many natural influenza hosts, including pigs and horses, but not in humans or ferrets. Here, we engineered HEK293 cells to express the hydoxylase gene (CMAH) that converts Neu5Ac to Neu5Gc, or knocked out the Sia-CMP transport gene (SLC35A1), resulting in cells that express 95% Neu5Gc or minimal level of Sias, respectively. H3N2 (X-31) showed significantly reduced infectivity in Neu5Gc-rich cells compared to wild-type HEK293 (>95% Neu5Ac). To determine the effects on binding and fusion, we generated supported lipid bilayers (SLBs) derived from the plasma membranes of these cells and carried out single particle microscopy. H3N2 (X-31) exhibited decreased binding to Neu5Gc-containing SLBs, but no significant difference in H3N2 (X-31)'s fusion kinetics to either SLB type, suggesting that reduced receptor binding does not affect subsequent membrane fusion. This finding suggests that for this virus to adapt to host cells rich in Neu5Gc, only receptor affinity changes are required without further adaptation of virus fusion machinery. IMPORTANCE Influenza A virus (IAV) infections continue to threaten human health, causing over 300,000 deaths yearly. IAV infection is initiated by the binding of influenza glycoprotein hemagglutinin (HA) to host cell sialic acids (Sias) and the subsequent viral-host membrane fusion. Generally, human IAVs preferentially bind to the Sia N-acetylneuraminic acid (Neu5Ac). Yet, other mammalian hosts, including pigs, express diverse nonhuman Sias, including N-glycolylneuraminic acid (Neu5Gc). The role of Neu5Gc in human IAV infections in those hosts is not well-understood, and the variant form may play a role in incidents of cross-species transmission and emergence of new epidemic variants. Therefore, it is important to investigate how human IAVs interact with Neu5Ac and Neu5Gc. Here, we use membrane platforms that mimic the host cell surface to examine receptor binding and membrane fusion events of human IAV H3N2. Our findings improve the understanding of viral entry mechanisms that can affect host tropism and virus evolution.

Characterization of TGF-ß by Induced Oxidative Stress in Human Trabecular Meshwork Cells.

Oxidative stress generated by reactive oxygen species (ROS) plays a critical role in the pathomechanism of glaucoma, which is a multifactorial blinding disease that may cause irreversible damage within human trabecular meshwork cells (HTMCs). It is known that the transforming growth factor-ß (TGF-ß) signaling pathway is an important component of oxidative stress-induced damage related to extracellular matrix (ECM) fibrosis and activates cell antioxidative mechanisms. To elucidate the dual potential roles and regulatory mechanisms of TGF-ß in effects on HTMCs, we established an in vitro oxidative model using hydrogen peroxide (H2O2) and further focused on TGF-ß-related oxidative stress pathways and the related signal transduction. Via a series of cell functional qualitative analyses to detect related protein level alterations and cell fibrosis status, we illustrated the role of TGF-ß1 and TGF-ß2 in oxidative stress-induced injury by shTGF-ß1 and shTGF-ß2 knockdown or added recombinant human TGF-ß1 protein (rhTGF-ß1). The results of protein level showed that p38 MAPK, TGF-ß, and its related SMAD family were activated after H2O2 stimulation. Cell functional assays showed that HTMCs with H2O2 exposure duration had a more irregular actin architecture compared to normal TM cells. Data with rhTGF-ß1 (1 ng/mL) pretreatment reduced the cell apoptosis rate and amount of reactive oxygen species (ROS), while it also enhanced survival. Furthermore, TGF-ß1 and TGF-ß2 in terms of antioxidant signaling were related to the activation of collagen I and laminin, which are fibrosis-response proteins. Succinctly, our study demonstrated that low concentrations of TGF-ß1 (1 ng/mL) preserves HTMCs from free radical-mediated injury by p-p38 MAPK level and p-AKT signaling balance, presenting a signaling transduction mechanism of TGF-ß1 in HTMC oxidative stress-related therapies.

Targeting UDP-glucose dehydrogenase inhibits ovarian cancer growth and metastasis.

More than 70% of patients with ovarian cancer are diagnosed in advanced stages. Therefore, it is urgent to identify a promising prognostic marker and understand the mechanism of ovarian cancer metastasis development. By using proteomics approaches, we found that UDP-glucose dehydrogenase (UGDH) was up-regulated in highly metastatic ovarian cancer TOV21G cells, characterized by high invasiveness (TOV21GHI ), in comparison to its parental control. Previous reports demonstrated that UGDH is involved in cell migration, but its specific role in cancer metastasis remains unclear. By performing immunohistochemical staining with tissue microarray, we found overexpression of UGDH in ovarian cancer tissue, but not in normal adjacent tissue. Silencing using RNA interference (RNAi) was utilized to knockdown UGDH, which resulted in a significant decrease in metastatic ability in transwell migration, transwell invasion and wound healing assays. The knockdown of UGDH caused cell cycle arrest in the G0 /G1 phase and induced a massive decrease of tumour formation rate in vivo. Our data showed that UGDH-depletion led to the down-regulation of epithelial-mesenchymal transition (EMT)-related markers as well as MMP2, and inactivation of the ERK/MAPK pathway. In conclusion, we found that the up-regulation of UGDH is related to ovarian cancer metastasis and the deficiency of UGDH leads to the decrease of cell migration, cell invasion, wound healing and cell proliferation ability. Our findings reveal that UGDH can serve as a prognostic marker and that the inhibition of UGDH is a promising strategy for ovarian cancer treatment.

Indirect Sensing of Lower Aliphatic Ester Using Atomic Gold Decorated Polyaniline Electrode.

Novel sensing materials have been formed by decorating polyaniline conducting polymers with atomic gold clusters where the number of atoms is precisely defined. Such materials exhibit unique electrocatalytic properties of electrooxidation to aliphatic alcohols, although analytes with other functional groups have not been studied. This paper reports a study of cyclic voltammetric patterns obtained with bi-atomic gold nanocomposite response to analytes with other functional groups for sensor applications. Principal component analysis shows separation among normal-propanol, iso-propanol and ethyl formate/ethanol groups. Indirect sensing of ethyl formate is demonstrated by electrooxidation of the product upon hydrolysis in alkaline medium. Voltammograms of ethyl formate are studied in gaseous phases.

Prognostic significance of lung radiation dose in patients with esophageal cancer treated with neoadjuvant chemoradiotherapy.

BACKGROUND: The prognostic significance of radiation dose to the lung or heart is unknown in esophageal cancer patients receiving neoadjuvant chemoradiotherapy followed by surgery (trimodal therapy). This study aimed to determine the association between lung and heart radiation dose volumes and prognosis of esophageal cancer after trimodal therapy. METHODS: This study reviewed 123 esophageal cancer patients treated with trimodal therapy in two tertiary institutions between 2010 and 2015. The dose-volume histogram parameter of Vx was defined as the percentage of total organ volume receiving a radiation dose of x (Gy) or more. Predictors of overall survival (OS) were identified using Cox regression models. Receiver-operating characteristic curves were used to select cut-off values for dose-volume. RESULTS: Median follow-up was 28.3 months (range: 4.7-92.8 months). Median OS and progression-free survival were 34.0 months (95% confidence interval [CI]: 27.4-40.6 months) and 24.8 months (95% CI, 18.9-30.7 months), respectively. Multivariate analyses showed that lung V20 (hazard ratio, 1.09; 95% CI: 1.04-1.14; p < 0.001) and lung V5 (hazard ratio, 1.02; 95% CI: 1.00-1.05; p = 0.03) were associated with OS when adjusting for surgical margin and pathological treatment response. The 5-year OS for patients with lung V20 ≤ 23% vs. patients with lung V20 > 23% was 54.4% vs. 5% (p < 0.001) whereas that for patients with lung V5 ≤ 56% vs. patients with lung V5 > 56% was 81.5% vs. 23.4% (p < 0.001). Mean heart dose showed no association with survival outcomes. CONCLUSIONS: Lung radiation dose was independently associated with survival outcomes in esophageal cancer patients treated with neoadjuvant chemoradiotherapy and surgery.

Upregulation of LGALS1 is associated with oral cancer metastasis.

BACKGROUND: Oral cancer metastasis is a devastating process that contributes to poor prognosis and high mortality, yet its detailed underlying mechanisms remain unclear. Here, we aimed to evaluate metastasis-specific markers in oral cancer and to provide comprehensive recognition concerning functional roles of the specific target in oral cancer metastasis. METHODS: Lectin, galactoside-binding, soluble, 1 (LGALS1) was identified by secretomic analysis. LGALS1 expression of patient samples with oral cancer on the tissue microarray were examined by immunochemical (IHC) staining. Small interfering RNA (siRNA)-mediated knockdown of LGALS1 revealed the role of LGALS1 in oral cancer metastasis in vitro and in vivo. RESULTS: LGALS1 was observed to be upregulated in highly invasive oral cancer cells, and elevated LGALS1 expression was correlated with cancer progression and lymph node metastasis in oral cancer tissue specimens. Functionally, silencing LGALS1 resulted in suppressed cell growth, wound healing, cell migration, and cell invasion in oral cancer cells in vitro. Knockdown of LGALS1 in highly invasive oral cancer cells dramatically inhibited lung metastasis in an in vivo mouse model. Mechanistic studies suggested p38 mitogen-activated protein kinase (MAPK) phosphorylation, upregulated MMP-9, and mesenchymal phenotypes of epithelial-mesenchymal transition (EMT) in highly invasive oral cancer cells, whereas siRNA against LGALS1 resulted in the inactivation of p38 MAPK pathway, downregulated MMP-9, and EMT inhibition. CONCLUSIONS: These findings demonstrate that elevated LGALS1 is strongly correlated with oral cancer progression and metastasis, and that it could potentially serve as a prognostic biomarker and an innovative target for oral cancer therapy.

Proteomic analysis of honokiol-induced cytotoxicity in thyroid cancer cells.

AIMS: Honokiol is a natural product extracted from herbal plants such as the Magnolia species which have been shown to exhibit anti-tumor and anti-metastatic properties. However, the effects of honokiol on thyroid cancers are largely unknown. MATERIALS AND METHODS: To determine whether honokiol might be useful for the treatment of thyroid cancer and to elucidate the mechanism of toxicity of honokiol, we analyzed the impact of honokiol treatment on differential protein expression in human thyroid cancer cell line ARO using lysine-labeling two-dimensional difference gel electrophoresis (2D-DIGE) combined with mass spectrometry (MS). KEY FINDINGS: This study revealed 178 proteins that showed a significant change in expression levels and also revealed that honokiol-induced cytotoxicity in thyroid cancer cells involves dysregulation of cytoskeleton, protein folding, transcription control and glycolysis. SIGNIFICANCE: Our work shows that combined proteomic strategy provides a rapid method to study the molecular mechanisms of honokiol-induced cytotoxicity in thyroid cancer cells. The identified targets may be useful for further evaluation as potential targets in thyroid cancer therapy.