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Stroik, M. R.

Publications and source records attributed to Stroik, M. R..

3 recordsLinked to original sources

In Utero CFTR Modulation Alleviates Disease in G551D Cystic Fibrosis Pigs

Previous studies indicate that pigs with CFTR-null and CFTR-{Delta}F508 mutations develop multiorgan disease similar to that in people with cystic fibrosis (CF). At birth, their airways exhibit host defense defects that predispose to airway infection, inflammation, and mucus accumulation. The CFTR-G551D mutation causes CF by producing CFTR channels that localize correctly but have reduced channel activity. Ivacaftor (VX-770) is a small molecule drug developed to potentiate CFTR activity. To test the phenotype of the CFTR-G551D mutation in pigs and determine whether ivacaftor can rescue CF abnormalities, we developed CFTRG551D/G551D (CF-G551D) pigs through homologous recombination in fetal fibroblasts and somatic cell nuclear transfer. Newborn CF-G551D piglets exhibited phenotypes similar to CF-null piglets, including meconium ileus, exocrine pancreatic destruction, micro-gallbladder, vas deferens destruction, and airway structural abnormalities. Compared to wild-type pigs, CF-G551D pigs had reduced forskolin-stimulated short-circuit current in airway and intestinal tissues. Ivacaftor increased the single-channel open state probability of CFTR-G551D and increased short-circuit current to near wild-type levels. Similar to our other CF pig models, we found that 100% of CF-G551D pigs were born with meconium ileus. To test whether in utero ivacaftor treatment could prevent or alleviate meconium ileus, pregnant sows were treated with ivacaftor beginning at day 35 of gestation and continuing until delivery. This treatment rescued the pancreas, gallbladder, and vas deferens phenotype in the majority of CF-G551D pigs. Animals that were spared from meconium ileus were able to survive without ivacaftor treatment. Airway disease developed similar to other CF pig models. These findings indicate that this model may be useful for studies in which CFTR function can be reversed, for investigating in utero CFTR correction strategies, and for longitudinal studies in CF pigs.

physiology↗

Development and Initial Characterization of Pigs with DNAI1 Mutations and Primary Ciliary Dyskinesia

Mutations in more than 50 different genes cause primary ciliary dyskinesia (PCD) by disrupting the activity of motile cilia that facilitate mucociliary transport (MCT). Knowledge of PCD has come from studies identifying disease-causing mutations, characterizing structural cilia abnormalities, finding genotype-phenotype relationships, and studying the cell biology of cilia. Despite these important findings, we still lack effective treatments and people with PCD have significant pulmonary impairment. As with many other diseases, a better understanding of pathogenic mechanisms may lead to effective treatments. To pursue disease mechanisms, we used CRISPR-Cas9 to develop a PCD pig with a disrupted DNAI1 gene. PCD pig airway cilia lacked the outer dynein arm and had impaired beating. MCT was impaired under both baseline conditions and after cholinergic stimulation in PCD pigs. Neonatal PCD pigs developed neonatal respiratory distress with evidence of atelectasis, air trapping, and airway mucus obstruction. Despite airway mucus accumulation, lung bacterial counts were similar between neonatal wild-type and PCD pigs. Sinonasal disease was present in all neonatal PCD pigs. Older PCD pigs developed worsening airway mucus obstruction, inflammation, and bacterial infection. This pig model closely mimics the disease phenotype seen in people with PCD and can be used to better understand the pathophysiology of PCD airway disease.

physiology↗

HSP90 inhibition modulates NFB signaling in airway goblet cell metaplasia

Goblet cell metaplasia and mucus hyper-production are key features of chronic muco-obstructive lung diseases such as asthma, chronic bronchitis, and cystic fibrosis. Various mechanisms lead to goblet cell metaplasia in the airways; the driving mechanism for goblet cell metaplasia in a specific patient may be unknown. We recently found that heat shock protein 90 (HSP90) is important for both IL-13- and IL-17- induced airway goblet cell metaplasia. HSP90 interacts with multiple clients that are important in goblet cell metaplasia including Akt, Jak/STAT, IRS, Notch, and various kinases involved in NF{kappa}B signaling. Here, we used a targeted phospho-proteomic approach to identify candidate HSP90 clients modulated by the HSP90-inhibitor geldanamycin. NF{kappa}B family members were enriched amongst the top candidate targets of HSP90 inhibition in IL-13 an organotypic model of human airway epithelia. We hypothesized that HSP90 inhibition modulated goblet cell metaplasia by interfering with NF{kappa}B signaling. We used transcription factor activation, nuclear translocation, and phospho-specific immunofluorescence assays to investigate how IL-13 exposure and HSP90 inhibition modulated NF{kappa}B. We found that HSP90 inhibition prevented goblet cell metaplasia by non-canonically blocking NF{kappa}B p100/p52 function in human airway epithelia. NF{kappa}B modulation via its interaction with HSP90 is a pharmaceutically feasible therapeutic target for goblet cell metaplasia; this approach may enable treatment of patients with chronic muco-inflammatory lung diseases with both known or unidentified disease-driving mechanisms.

cell biology↗