Lung disease is the major cause of morbidity and mortality in cystic fibrosis (CF) patients. Here, a viscous cycle of infection and inflammation lead to persistent neutrophilia and bronchiectasis that destroy the lung. One of the cornerstones of a comprehensive treatment plan is the use of anti-inflammatory drugs. While the significance of anti-inflammatory treatments was realized in the 1990s, there remains a dearth of drug therapies aimed toward treating the powerful and relentless inflammation in CF patients. Corticosteroids, used during pulmonary exacerbations, have positive effects and improve CF pathophysiology, such as reducing mucus and edema, inhibiting chemotaxis and adhesion, and activating leukocytes. Corticosteroids are not effective for long-term use due to their extensive side-effects. Nonetheless, anti-inflammatories remain an attractive option for the treatment of CF lung disease. Orai1 is a plasma membrane Ca2+ channel that is expressed in the lung and plays in key role in mediating inflammation. For example, activation of Orai1 occurs during store operated Ca2+ entry (SOCE), which in airway epithelia triggers secretion of the neutrophil chemoattractant IL-8. Therefore, inhibition of Orai1 is an attractive, drugable target. Yet to date, no anti-Orai1 therapies exist. Short Palate LUng and Nasal epithelial Clone 1 (SPLUNC1) is a secreted protein that is highly expressed in the lung and is thought to play a critical role in maintaining lung health. SPLUNC1 is abundant in broncho-alveolar lavage, suggesting that it plays a role in the innate defense of the lower airways. Importantly, we have recently discovered that SPLUNC1 negatively regulates Orai1. Thus, our data indicate that SPLUNC1 inhibits store operated Ca2+ entry (SOCE) and has the potential to reduce CF inflammation. Indeed, SPLUNC1 knockout mice have a hyperinflammatory lung phenotype and SPLUNC1 protein is absent from CF patientÂ’s BAL. We have identified the active site within SPLUNC1 that regulates Orai1, and a peptide corresponding to this region (called ?6) inhibits Orai1 in an equipotent fashion as full length SPLUNC1 and is anti-inflammatory in an allergic mouse model. In this study, we propose to develop novel ?6 peptide analogues that reduce inflammation by inhibiting Orai1-dependent Ca2+ influx and to test them in murine chronic CF infection models. There are no current effective anti-inflammatories for CF, so this constitutes a novel approach. In addition, this is the first therapeutic that targets Orai1. Furthermore, several inflammatory cells will be tested for inflammation control using ?6 and its mutants.
Public Health Relevance Statement: Narrative One of the cornerstones of a comprehensive treatment plan for CF patients is the use of anti- inflammatory drugs. While the significance of anti-inflammatory treatment was realized in the 1990s, there remains a dearth of drug therapies aimed toward treating the powerful and relentless inflammation in CF patients. We propose to develop a stable peptide, which reduces inflammation by regulating the Orai1-dependent influx of Ca2+, and delivers the therapeutic by inhalation.
Project Terms: Abate; Active Sites; Adhesions; Adrenal Cortex Hormones; Adverse effects; Affect; airway epithelium; Alanine; Allergic; Anti-inflammatory; Anti-Inflammatory Agents; Bacterial Infections; base; Binding; Biological Sciences; Bronchiectasis; Bronchoalveolar Lavage; CA-15-3 Antigen; Calcium; Cathepsins; Cathepsins B; Caucasians; Cell membrane; cell type; Cells; Charge; Chemotactic Factors; Chemotaxis; Chronic; Chronic lung disease; Confocal Microscopy; crosslink; Crystallization; Cystic Fibrosis; cystic fibrosis airway; cystic fibrosis mouse; cystic fibrosis patients; Cystic Fibrosis Transmembrane Conductance Regulator; cytokine; Data; design; Development; Drug Targeting; Dyes; Edema; efficacy trial; Enzyme-Linked Immunosorbent Assay; Epithelial; epithelial Na+ channel; Exhibits; Functional disorder; Funding; Generations; Genetic Diseases; Glosso-Sterandryl; Goals; Health; Ibuprofen; IL8 gene; Immune; immunogenic; improved; in vivo; Infection; Inflammation; Inflammatory; Inhalation; Knockout Mice; Lead; Legal patent; Length; Leukocyte Elastase; Leukocytes; Libraries; Lung; Lung diseases; Lung Inflammation; Measures; Mediating; Modeling; Morbidity - disease rate; mortality; mouse model; Mucous body substance; Mus; mutant; neutrophil; Neutrophilia; Newborn Infant; Non-Steroidal Anti-Inflammatory Agents; Nose; novel; novel strategies; Palate; Pathology; peptide analog; peptide drug; Peptide Hydrolases; Peptides; peptidomimetics; Pharmaceutical Preparations; Pharmacologic Substance; Pharmacotherapy; Phase; Phase II Clinical Trials; Phenotype; Play; preclinical study; programs; Proteins; Pseudomonas aeruginosa; Pulmonary Cystic Fibrosis; Pulmonary Fibrosis; Quartz; Reader; response; Role; Sepharose; Sputum; success; Symptoms; Testing; Thapsigargin; Therapeutic; therapeutic target; Therapeutic Uses; Toxicology; treatment planning
