A multimodal iPSC platform for cystic fibrosis drug testing.

Cystic fibrosis is a monogenic lung disease caused by dysfunction of the cystic fibrosis transmembrane conductance regulator anion channel, resulting in significant morbidity and mortality. The progress in elucidating the role of CFTR using established animal and cell-based models led to the recent discovery of effective modulators for most individuals with CF. However, a subset of individuals with CF do not respond to these modulators and there is an urgent need to develop novel therapeutic strategies.

Chemical modifications of adenine base editor mRNA and guide RNA expand its application scope.

CRISPR-Cas9-associated base editing is a promising tool to correct pathogenic single nucleotide mutations in research or therapeutic settings. Efficient base editing requires cellular exposure to levels of base editors that can be difficult to attain in hard-to-transfect cells or in vivo. Here we engineer a chemically modified mRNA-encoded adenine base editor that mediates robust editing at various cellular genomic sites together with moderately modified guide RNA, and show its therapeutic potential in correcting pathogenic single nucleotide mutations in cell and animal models of diseases.

Discovery of a novel chemotype of potent human ENaC blockers using a bioisostere approach. Part 2: α-Branched quaternary amines.

We report the synthesis and biological evaluation of a series of novel α-branched pyrazinoyl quaternary amines for their ability to block ion transport via the epithelial sodium channel (ENaC) in human bronchial epithelial cells (HBECs). Compound 12 g has an IC(50) of 30 nM and is highly efficacious in the Guinea-pig tracheal potential difference (TPD) model of ENaC blockade with an ED(50) of 1 μg kg(-1) at 1h. In addition the SAR results demonstrate for the first time the chiral nature of the binding site of human ENaC.

Discovery of a novel chemotype of potent human ENaC blockers using a bioisostere approach. Part 1: quaternary amines.

We report the identification of a novel series of human epithelial sodium channel (ENaC) blockers that are structurally distinct from the pyrazinoyl guanidine chemotype found in prototypical ENaC blockers such as amiloride. Following a rational design hypothesis a series of quaternary amines were prepared and evaluated for their ability to block ion transport via ENaC in human bronchial epithelial cells (HBECs). Compound 11 has an IC(50) of 200nM and is efficacious in the Guinea-pig tracheal potential difference (TPD) model of ENaC blockade with an ED(50) of 44μgkg(-1) at 1h.

In vivo assessments of mucus dynamics in the rat lung using a Gd-Cy5.5-bilabeled contrast agent for magnetic resonance and optical imaging.

Dysfunctions in mucociliary clearance are associated with the accelerated loss of lung function in several respiratory diseases. Approaches enabling the in vivo visualization of mucus dynamics in rodents at high resolution and sensitivity would be beneficial for experimental lung research. We describe the synthesis and characterization of two bilabeled amino dextran-based probes binding specifically to mucin.

Characterization of cigarette smoke-induced inflammatory and mucus hypersecretory changes in rat lung and the role of CXCR2 ligands in mediating this effect.

Repetitive, acute inflammatory insults elicited by cigarette smoke (CS) contribute to the development of chronic obstructive pulmonary disease (COPD), a disorder associated with lung inflammation and mucus hypersecretion. Presently, there is a poor understanding of the acute inflammatory mechanisms involved in this process. The aims of this study were to develop an acute model to investigate temporal inflammatory changes occurring after CS exposure.

Mucociliary clearance is enhanced in rat models of cigarette smoke and lipopolysaccharide-induced lung disease.

In this study, the authors describe a new technique enabling the rapid assessment of mucociliary clearance (MCC) in rats and characterize this aspect of innate host defense in 2 animal models of bronchitis. Following instillation into the airways, fluorescent microspheres were rapidly cleared over 24 hours, with 60% to 80% of clearance occurring within 4 hours. On a background of airway neutrophilia and mucus hypersecretion, induced by either lipopolysaccharide or cigarette smoke, MCC was significantly enhanced.