A Novel Role for Aquaporin-5 in Enhancing Microtubule Organization and Stability

Aquaporin-5 (AQP5) is a water-specific channel located on the apical surface of airway epithelial cells. In addition to regulating transcellular water permeability, AQP5 can regulate paracellular permeability, though the mechanisms by which this occurs have not been determined. Microtubules also regulate paracellular permeability. Here, we report that AQP5 promotes microtubule assembly and helps maintain the assembled microtubule steady state levels with slower turnover dynamics in cells. Specifically, reduced levels of AQP5 correlated with lower levels of assembled microtubules and decreased paracellular permeability. In contrast, overexpression of AQP5 increased assembly of microtubules, with evidence of increased MT stability, and promoted the formation of long straight microtubules in the apical domain of the epithelial cells. These findings indicate that AQP5-mediated regulation of microtubule dynamics modulates airway epithelial barrier properties and epithelial function

Bio-inspired artemether-loaded human serum albumin nanoparticles for effective control of malaria-infected erythrocytes

Aim: The intra-erythrocytic development of the malarial parasite is dependent on active uptake of nutrients, including human serum albumin (HSA), into parasitized red blood cells (pRBCs). We have designed HSA-based nanoparticles as a potential drug-delivery option for antimalarials. Methods: Artemether-loaded nanoparticles (AANs) were designed and antimalarial activity evaluated in vitro/in vivo using Plasmodium falciparum/Plasmodium berghei species, respectively. Results: Selective internalization of AAN into Plasmodium-infected RBCs in preference to healthy erythrocytes was observed using confocal imaging. In vitro studies showed 50% dose reduction for AAN as compared with drug-only controls to achieve IC50 levels of inhibition. The nanoparticles exhibited twofold higher peak drug concentrations in RBCs with antimalarial activity at 50% of therapeutic doses in P. bergei infected mice. Conclusion: Novel HSA-based nanoparticles offer safe and effective approach for selective targeting of antimalarial drugs

Aquaporin 5 Polymorphisms and Rate of Lung Function Decline in Chronic Obstructive Pulmonary Disease

RATIONALE: Aquaporin-5 (AQP5) can cause mucus overproduction and lower lung function. Genetic variants in the AQP5 gene might be associated with rate of lung function decline in chronic obstructive pulmonary disease (COPD). METHODS: Five single nucleotide polymorphisms (SNPs) in AQP5 were genotyped in 429 European American individuals with COPD randomly selected from the NHLBI Lung Health Study. Mean annual decline in FEV(1) % predicted, assessed over five years, was calculated as a linear regression slope, adjusting for potential covariates and stratified by smoking status. Constructs containing the wildtype allele and risk allele of the coding SNP N228K were generated using site-directed mutagenesis, and transfected into HBE-16 (human bronchial epithelial cell line). AQP5 abundance and localization were assessed by immunoblots and confocal immunofluorescence under control, shear stress and cigarette smoke extract (CSE 10%) exposed conditions to test for differential expression or localization. RESULTS: Among continuous smokers, three of the five SNPs tested showed significant associations (0.02>P>0.004) with rate of lung function decline; no associations were observed among the group of intermittent or former smokers. Haplotype tests revealed multiple association signals (0.012>P>0.0008) consistent with the single-SNP results. In HBE16 cells, shear stress and CSE led to a decrease in AQP5 abundance in the wild-type, but not in the N228K AQP5 plasmid. CONCLUSIONS: Polymorphisms in AQP5 were associated with rate of lung function decline in continuous smokers with COPD. A missense mutation modulates AQP-5 expression in response to cigarette smoke extract and shear stress. These results suggest that AQP5 may be an important candidate gene for COPD

Regulatory T cell DNA methyltransferase inhibition accelerates resolution of lung inflammation

Acute respiratory distress syndrome (ARDS) is a common and often fatal inflammatory lung condition without effective targeted therapies. Regulatory T cells (Tregs) resolve lung inflammation, but mechanisms that enhance Tregs to promote resolution of established damage remain unknown. DNA demethylation at the forkhead box protein 3 (Foxp3) locus and other key Treg loci typify the Treg lineage. To test how dynamic DNA demethylation affects lung injury resolution, we administered the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (DAC) to wild-type (WT) mice beginning 24 hours after intratracheal LPS-induced lung injury. Mice that received DAC exhibited accelerated resolution of their injury. Lung CD4+CD25hi Foxp3+ Tregs from D AC-treated WT mice increased in number and displayed enhanced Foxp3 expression, activation state, suppressive phenotype, and proliferative capacity. Lymphocyte-deficient recombinase activating gene-1-null mice and Treg-depleted (diphtheria toxin-treated Foxp3DTR) mice did not resolve their injury in response to DAC. Adoptive transfer of 2 ×105 DAC-treated, but not vehicle-treated, exogenous Tregs rescued Treg-deficient mice from ongoing lung inflammation. In addition, in WT mice with influenza-induced lung inflammation, DAC rescue treatment facilitated recovery of their injury and promoted an increase in lung Treg number. Thus, DNA methyltransferase inhibition, at least in part, augments Treg number and function to accelerate repair of experimental lung injury. Epigenetic pathways represent novel manipulable targets for the treatment of ARDS

Chemical investigation of some Indian plants. Part VI

Several known compounds belonging to the class of acids, alcohols, alkaloids, anthraquinones, carbohydrates, coumarins, isocoumarins, steroids, triterpenoids and xanthones have been isolated from a number of Indian plants

Relevant Assay to Study the Adhesion of Plasmodium falciparum-Infected Erythrocytes to the Placental Epithelium

In placental malaria, Plasmodium falciparum-infected erythrocytes adhere to the apical plasma membrane of the placental epithelium, triggering an impairment of placental function detrimental to the fetus. The design of anti-adhesion intervention strategies requires a detailed understanding of the mechanisms involved. However, most adhesion assays lack in vivo relevance and are hardly quantitative. Here, we describe a flow cytometry-based adhesion assay that is fully relevant by using apical epithelial plasma membrane vesicles as the adhesion matrix, and being applicable to infected erythrocytes directly isolated from patients. Adhesion is measured both as the percentage of pathogens bound to epithelial membrane vesicles as well as the mean number of vesicles bound per infected erythrocytes. We show that adhesins alternative to those currently identified could be involved. This demonstrates the power of this assay to advance our understanding of epithelial adhesion of infected erythrocytes and in the design of intervention strategies

Looking to the future of zebrafish as a model to understand the genetic basis of eye disease

In this brief commentary, we provide some of our thoughts and opinions on the current and future use of zebrafish to model human eye disease, dissect pathological progression and advance in our understanding of the genetic bases of microphthalmia, andophthalmia and coloboma (MAC) in humans. We provide some background on eye formation in fish and conservation and divergence across vertebrates in this process, discuss different approaches for manipulating gene function and speculate on future research areas where we think research using fish may prove to be particularly effective

Anemia and adverse outcomes in a chronic obstructive pulmonary disease population with a high burden of comorbidities an analysis from SPIROMICS

Rationale: Chronic obstructive pulmonary disease (COPD) is a common cause of morbidity and associated with a significant burden of comorbidities. Although anemia is associated with adverse outcomes in COPD, its contribution to outcomes in individuals with other comorbid chronic diseases is not well understood. Objectives: This study examines the association of anemia with outcomes in a large, well-characterized COPD cohort, and attempts to understand the contribution of anemia to outcomes and phenotypes in individuals with other comorbidities. Methods: Participants with COPD from SPIROMICS (the Subpopulations and Intermediate Outcome Measures in COPD Study) were analyzed in adjusted models to determine the associations of normocytic anemia with clinical outcomes, computed tomographic measures, and biomarkers. Analysis was additionally performed to understand the independence and possible interactions related to cardiac and metabolic comorbidities. Results: A total of 1,789 individuals with COPD from SPIROMICS had data on hemoglobin, and of these 7.5% (n = 135) were found to have normocytic anemia. Anemic participants were older with worse airflow obstruction, a higher proportion of them were African Americans, and they had a higher burden of cardiac and metabolic comorbidities. Anemia was strongly associated with 6-minute walk distance (b, 261.43; 95% confidence interval [CI], 285.11 to 237.75), modified Medical Research Council dyspnea questionnaire (b, 0.27; 95% CI, 0.11-0.44), and St. George's Respiratory Questionnaire (b, 3.90; 95% CI, 1.09-6.71), and these adjusted associations were stronger among those with two or more cardiac and metabolic comorbidities. Anemia was associated with higher levels of serum C-reactive protein, soluble receptor for advanced glycosylation endproducts, and epithelial cadherin-1, findings that persisted when in those with a high burden of comorbidities. Conclusions: Anemia is associated with worse exercise capacity, greater dyspnea, and greater disease severity among adults with COPD, particularly among those with comorbid chronic cardiac and metabolic diseases. The biomarkers found in anemic individuals suggest inflammation, lung tissue injury, and oxidative stress as possible pathways for the adverse correlations of anemia with outcomes in COPD; however, substantial further study is required to better understand these potential mechanisms

Improving the biopharmaceutical attributes of mangiferin using vitamin E-TPGS co-loaded self-assembled phosholipidic nano-mixed micellar systems

The current research work encompasses the development, characterization, and evaluation of self-assembled phospholipidic nano-mixed miceller system (SPNMS) of a poorly soluble BCS Class IV xanthone bioactive, mangiferin (Mgf) functionalized with co-delivery of vitamin E TPGS. Systematic optimization using I-optimal design yielded self-assembled phospholipidic nano-micelles with a particle size of  80% of drug release in 15 min. The cytotoxicity and cellular uptake studies performed using MCF-7 and MDA-MB-231 cell lines demonstrated greater kill and faster cellular uptake. The ex vivo intestinal permeability revealed higher lymphatic uptake, while in situ perfusion and in vivo pharmacokinetic studies indicated nearly 6.6- and 3.0-folds augmentation in permeability and bioavailability of Mgf. In a nutshell, vitamin E functionalized SPNMS of Mgf improved the biopharmaceutical performance of Mgf in rats for enhanced anticancer potency