Chloroquine Attenuates Asthma Development by Restoring Airway Smooth Muscle Cell Phenotype Via the ROS-AKT Pathway.

Switching of airway smooth muscle (ASM) cell phenotype from differentiated-contractile to dedifferentiated-proliferative/synthetic state often occurs in asthmatic subjects with airway dysfunction. Evidence has been provided that chloroquine (an agonist of bitter taste receptors) presented benefits to ASM cell function implicated in asthma. However, the underlying mechanism is unclear. House dust mite (HDM)-sensitized mice were administered with chloroquine or dexamethasone before challenge. BALF and lung tissue were obtained for cell counting, histological analysis or ELISA. Primary cultured ASM cells were stimulated with transforming growth factor (TGF)-ß1 or H2O2. Cells and supernatant were collected for the detection of ASM phenotype, ROS level, and proinflammatory cytokine production. In HDM-sensitized mice, chloroquine attenuated airway hyperresponsiveness (AHR), inflammation and remodeling with an inhibition of immunoglobulin E, IL-4/-13, and TGF-ß1 in BALF. ASM cell proliferation (PCNA), hypertrophy (α-SMA), and parasecretion (MMP-9 and MMP-13) were strongly suppressed by chloroquine, hinting the rebalance of the heterogeneous ASM populations in asthmatic airway. Our data in vitro indicated that chloroquine markedly restrained maladaptive alteration in ASM phenotype in concert with a remission of ROS. Using H2O2 and PI3K inhibitor (LY294002), we found that the inhibition of oxidative stress level and ROS-AKT signal by chloroquine may serve as a potential mechanism that dedicates to the restoration of the phenotypic imbalance in ASM cells. Overall, the present findings suggested that chloroquine improves asthmatic airway function by controlling ASM cell phenotype shift, sketching a novel profile of chloroquine as a new therapeutic candidate for airway remodeling.

The structure of blood-tumor barrier and distribution of chemotherapeutic drugs in non-small cell lung cancer brain metastases.

BACKGROUND: Brain metastasis is an important cause of increased mortality in patients with non-small cell lung cancer (NSCLC). In brain metastasis, the blood-brain barrier (BBB) is frequently impaired, forming blood-tumor barrier (BTB). The efficacy of chemotherapy is usually very poor. However, the characteristics of BTB and the impacts of BTB on chemotherapeutic drug delivery remain unclear. The present study investigated the structure of BTB, as well as the distribution of routine clinical chemotherapeutic drugs in both brain and peripheral tumors. METHODS: Bioluminescent image was used to monitor the tumor load after intracranial injection of lung cancer Lewis cells in mice. The permeability of BBB and BTB was measured by fluorescent tracers of evans blue and fluorescein sodium. Transmission electron microscopy (TEM), immunohistochemistry and immunofluorescence were performed to analyze structural differences between BBB and BTB. The concentrations of chemotherapeutic drugs (gemcitabine, paclitaxel and pemetrexed) in tissues were assayed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). RESULTS: Brain metastases exhibited increased BTB permeability compared with normal BBB detected by fluorescence tracers. TEM showed abnormal blood vessels, damaged endothelial cells, thick basement membranes, impaired intercellular endothelial tight junctions, as well as increased fenestrae and pinocytotic vesicles in metastatic lesions. Immunohistochemistry and immunofluorescence revealed that astrocytes were distributed surrounded the blood vessels both in normal brain and the tumor border, but no astrocytes were found in the inner metastatic lesions. By LC-MS/MS analysis, gemcitabine showed higher permeability in brain metastases. CONCLUSIONS: Brain metastases of lung cancer disrupted the structure of BBB, and this disruption was heterogeneous. Chemotherapeutic drugs can cross the BTB of brain metastases of lung cancer but have difficulty crossing the normal BBB. Among the three commonly used chemotherapy drugs, gemcitabine has the highest distribution in brain metastases. The permeability of chemotherapeutic agents is related to their molecular weight and liposolubility.

Rh(III)-Catalyzed Redox-Neutral C-H Activation/[3 + 2] Annulation of N-Phenoxy Amides with Propargylic Monofluoroalkynes.

An efficient and redox-neutral Rh(III)-catalyzed C-H activation/[3 + 2] annulation of N-phenoxy amides with propargylic monofluoroalkynes has been realized to afford 3-alkylidene dihydrobenzofurans with an interesting α-quaternary carbon center. Combined experimental and computational mechanistic studies revealed that a Rh(III)-Rh(V)-Rh(III) catalytic pathway/uncatalyzed intramolecular [H···F] bonding-assisted SN2'-type substitution cascade might be involved in the catalytic cycle, thereby enabling an excellent site-/regioselectivity with broad substrate/functional group compatibility, including the complete retention of the highly strained cyclobutyl structure in the 3-position.

Melatonin modulates airway smooth muscle cell phenotype by targeting the STAT3/Akt/GSK-3ß pathway in experimental asthma.

Among the troika of clinicopathologic features of asthma, airway remodelling has gained sufficient attention for its contribution to progressive airway narrowing. Much effort has been directed at the management of airway smooth muscle cells (ASMCs), but few attempts have proven to prevent the progression of remodelling. Recently, accumulating data have shown the anti-inflammatory/anti-proliferative potency of melatonin (a crucial neurohormone involved in many physiological and pathological processes) in diverse cells. However, no evidence has confirmed its effect on ASMCs. The present study investigates the benefits of melatonin in asthma, with an emphasis on airway remodelling. The results indicated that melatonin significantly attenuated airway hyperresponsiveness (AHR), inflammation and remodelling in a house dust mite (HDM) model. Melatonin markedly alleviated goblet cell hyperplasia/metaplasia, collagen deposition and airway smooth muscle hyperplasia/hypertrophy, implying the achievement of remodelling remission. The data obtained in vitro further revealed that melatonin notably inhibited ASMCs proliferation, VEGF synthesis and cell migration induced by PDGF, which might depend on STAT3 signalling. Moreover, melatonin remarkably relieved ASMCs contraction and reversed ASMCs phenotype switching induced by TGF-ß, probably via the Akt/GSK-3ß pathway. Altogether, our findings illustrated for the first time that melatonin improves asthmatic airway remodelling by balancing the phenotypic proportions of ASMCs, thus highlighting a novel purpose for melatonin as a potent option for the management of asthma.

Gas chromatography-mass spectrometry determination of earthy-musty odorous compounds in waters by two phase hollow-fiber liquid-phase microextraction using polyvinylidene fluoride fibers.

A rapid and sensitive method for the determination of earthy-musty odorous compounds, 2-methylisoborneol, 2-isopropyl-3-methoxy pyrazine, 2,4,6-trichloroanisole, 2,3,6-trichloroanisole, and geosmin, in water samples has been developed. The method was based on coupling a new polyvinylidene fluoride (PVDF) hollow-fiber liquid-phase microextraction system with gas chromatography-mass spectrometry (GC-MS). The PVDF hollow fibers have high porosity and an enhanced solvent compatibility for extraction of the target analytes. Experimental conditions were optimized by investigating the type of extraction solvent, sample pH, sodium chloride concentration, stirring speed, extraction time, and GC-MS conditions. Under optimized conditions, the earthy-musty odorous compounds exhibited good linearity (R>0.995) in the concentration range of 6.2-250ng/L. The repeatability and reproducibility of the method were lower than 6.8% and 9.8%, respectively. The limit of detection and limit of quantification values were lower than 2.0 and 6.2ng/L, respectively. The analysis of different water samples such as tap, pond, rive and waste water indicated minimal matrix effects. Analyte recoveries for real samples spiked at different concentrations were between 84.4% and 117.5%.

Ultrasound-assisted low-density solvent dispersive liquid-liquid extraction for the determination of alkanolamines and alkylamines in cosmetics with ion chromatography.

A new one-step sample preparation technique termed ultrasound-assisted low-density solvent dispersive liquid-liquid extraction (UA-LDS-DLLE) coupled with ion chromatography (IC) was developed for the determination of three alkanolamines and two alkylamines in complex samples. Sample matrices were rapidly dissolved and dispersed to form cloudy solutions by using two solvents, where target analytes were transferred into acid solutions, while liposoluble substances were dissolved in cyclohexane. The obtained extracts could be used directly for injection analysis without any additional purification because the potential matrix interferences had been effectively eliminated in extraction process. The extraction efficiency could be markedly enhanced and the extraction could be quickly accomplished within 13 min under the synergistic effects of ultrasound radiation, vibration and heating. Various parameters influencing extraction efficiency were evaluated using orthogonal array experimental design. The extraction performance of the approach was demonstrated for the determination of target analytes in 15 commercial cosmetics covering very different matrices. Linearity ranges of 0.3-50 mg L(-1) and limits of detection varying from 0.072 to 0.12 mg L(-1) were achieved. The recoveries ranged from 86.9-108.5% with the relative standard deviations (RSDs) of 1.2-6.2%. The method was proved to be a simple and effective extraction technique that provided an attractive alternative to the analysis of trace amounts of target analytes in large numbers of cosmetics.

[Determination of 15 volatile organic compound residues in cosmetics by headspace gas chromatography].

A headspace gas chromatography (HS-GC) method was developed for the rapid determination of multimixture of 15 residual volatile organic compounds in cosmetics. The experimental conditions of HS-GC such as headspace temperature, headspace time and the analytical conditions of GC were optimized. Cosmetic samples were extracted and cleaned-up by headspace at 60 degrees C for 30 min, determined by GC-flame ionization detector (FID) and quantified by external standard method. The 15 poisonous volatile organic compounds were separated efficiently from impurities with high sensitivity and reproducibility. The relative standard deviations (RSDs) were less than 5%, the recoveries were from 62.8%-116%, the linear range was 0.002-2.0 mg/L with a good linear correlation coefficient (r > 0.999) and the limits of detection were 0.09-0.68 mg/kg. By means of the above developed HS-GC method, 15 residual volatile organic compounds in cosmetics were detected accurately and simultaneously in a single sample injection. The method is accurate, simple, rapid, and is suitable for the trace analysis of multimixture of residual volatile organic compounds in various cosmetics.