@article{cortes_brodsky_chen_pridgen_odle_snider_cruse_putikova_masuda_doyle_et al._2022, title={Immunologic and pathologic characterization of a novel swine biomedical research model for eosinophilic esophagitis}, volume={3}, ISSN={["2673-6101"]}, DOI={10.3389/falgy.2022.1029184}, abstractNote={Eosinophilic esophagitis (EoE) is a chronic allergy-mediated condition with an increasing incidence in both children and adults. Despite EoE's strong impact on human health and welfare, there is a large unmet need for treatments with only one recently FDA-approved medication for EoE. The goal of this study was to establish swine as a relevant large animal model for translational biomedical research in EoE with the potential to facilitate development of therapeutics. We recently showed that after intraperitoneal sensitization and oral challenge with the food allergen hen egg white protein (HEWP), swine develop esophageal eosinophilia—a hallmark of human EoE. Herein, we used a similar sensitization and challenge treatment and evaluated immunological and pathological markers associated with human EoE. Our data demonstrate that the incorporated sensitization and challenge treatment induces (i) a systemic T-helper 2 and IgE response, (ii) a local expression of eotaxin-1 and other allergy-related immune markers, (iii) esophageal eosinophilia (>15 eosinophils/0.24 mm2), and (iv) esophageal endoscopic findings including linear furrows and white exudates. Thereby, we demonstrate that our sensitization and oral challenge protocol not only induces the underlying immune markers but also the micro- and macro-pathological hallmarks of human EoE. This swine model for EoE represents a novel relevant large animal model that can drive translational biomedical research to develop urgently needed treatment strategies for EoE.}, journal={FRONTIERS IN ALLERGY}, author={Cortes, Lizette M. and Brodsky, David and Chen, Celine and Pridgen, Tiffany and Odle, Jack and Snider, Douglas B. and Cruse, Glenn and Putikova, Arina and Masuda, Mia Y. and Doyle, Alfred D. and et al.}, year={2022}, month={Nov} }
 @article{slifer_hernandez_pridgen_carlson_messenger_madan_krishnan_laumas_blikslager_2021, title={Larazotide acetate induces recovery of ischemia-injured porcine jejunum via repair of tight junctions}, volume={16}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0250165}, abstractNote={Intestinal ischemia results in mucosal injury, including paracellular barrier loss due to disruption of tight junctions. Larazotide acetate (LA), a small peptide studied in Phase III clinical trials for treatment of celiac disease, regulates tight junctions (TJs). We hypothesized that LA would dose-dependently hasten recovery of intestinal ischemic injury via modulation of TJs. Ischemia-injured tissue from 6-8-week-old pigs was recovered in Ussing chambers for 240-minutes in the presence of LA. LA (1 μM but not 0.1 μM or 10 μM) significantly enhanced transepithelial electrical resistance (TER) above ischemic injured controls and significantly reduced serosal-to-mucosal flux LPS (P<0.05). LA (1 μM) enhanced localization of the sealing tight junction protein claudin-4 in repairing epithelium. To assess for the possibility of fragmentation of LA, anin vitroenzyme degradation assay using the brush border enzyme aminopeptidase M, revealed generation of peptide fragments. Western blot analysis of total protein isolated from uninjured and ischemia-injured porcine intestine showed aminopeptidase M enzyme presence in both tissue types, and mass spectrometry analysis of samples collected duringex vivoanalysis confirmed formation of LA fragments. Treatment of tissues with LA fragments had no effect alone, but treatment with a fragment missing both amino-terminus glycines inhibited barrier recovery stimulated by 1 μM LA. To reduce potential LA inhibition by fragments, a D-amino acid analog of larazotide Analog #6, resulted in a significant recovery response at a 10-fold lower dose (0.1 μM) similar in magnitude to that of 1 μM LA. We conclude that LA stimulates repair of ischemic-injured epithelium at the level of the tight junctions, at an optimal dose of 1 μM LA. Higher doses were less effective because of inhibition by LA fragments, which could be subverted by chirally-modifying the molecule, or microdosing LA.}, number={4}, journal={PLOS ONE}, author={Slifer, Zachary M. and Hernandez, Liliana and Pridgen, Tiffany A. and Carlson, Alexandra R. and Messenger, Kristen M. and Madan, Jay and Krishnan, B. Radha and Laumas, Sandeep and Blikslager, Anthony T.}, year={2021}, month={Apr} }
 @article{prasher_shrivastava_dahl_sharma-huynh_maturavongsadit_pridgen_schorzman_zamboni_ban_blikslager_et al._2021, title={Steroid Eluting Esophageal-Targeted Drug Delivery Devices for Treatment of Eosinophilic Esophagitis}, volume={13}, ISSN={["2073-4360"]}, url={https://www.mdpi.com/2073-4360/13/4/557}, DOI={10.3390/polym13040557}, abstractNote={Eosinophilic esophagitis (EoE) is a chronic atopic disease that has become increasingly prevalent over the past 20 years. A first-line pharmacologic option is topical/swallowed corticosteroids, but these are adapted from asthma preparations such as fluticasone from an inhaler and yield suboptimal response rates. There are no FDA-approved medications for the treatment of EoE, and esophageal-specific drug formulations are lacking. We report the development of two novel esophageal-specific drug delivery platforms. The first is a fluticasone-eluting string that could be swallowed similar to the string test “entero-test” and used for overnight treatment, allowing for a rapid release along the entire length of esophagus. In vitro drug release studies showed a target release of 1 mg/day of fluticasone. In vivo pharmacokinetic studies were carried out after deploying the string in a porcine model, and our results showed a high local level of fluticasone in esophageal tissue persisting over 1 and 3 days, and a minimal systemic absorption in plasma. The second device is a fluticasone-eluting 3D printed ring for local and sustained release of fluticasone in the esophagus. We designed and fabricated biocompatible fluticasone-loaded rings using a top-down, Digital Light Processing (DLP) Gizmo 3D printer. We explored various strategies of drug loading into 3D printed rings, involving incorporation of drug during the print process (pre-loading) or after printing (post-loading). In vitro drug release studies of fluticasone-loaded rings (pre and post-loaded) showed that fluticasone elutes at a constant rate over a period of one month. Ex vivo pharmacokinetic studies in the porcine model also showed high tissue levels of fluticasone and both rings and strings were successfully deployed into the porcine esophagus in vivo. Given these preliminary proof-of-concept data, these devices now merit study in animal models of disease and ultimately subsequent translation to testing in humans.}, number={4}, journal={POLYMERS}, author={Prasher, Alka and Shrivastava, Roopali and Dahl, Denali and Sharma-Huynh, Preetika and Maturavongsadit, Panita and Pridgen, Tiffany and Schorzman, Allison and Zamboni, William and Ban, Jisun and Blikslager, Anthony and et al.}, year={2021}, month={Feb} }
 @article{sheridan_pridgen_odle_van landeghem_blikslager_ziegler_2020, title={A Glial Cell Inhibitor Blocks Epithelial Barrier Repair in a Pig Model of Intestinal Ischemia}, volume={34}, ISSN={["1530-6860"]}, DOI={10.1096/fasebj.2020.34.s1.02030}, abstractNote={The gut epithelium functions as a barrier against toxic luminal contents which can repair efficiently after injury to prevent systemic illness and death. However, we have shown that repair is severely hindered in neonates as compared to juveniles in our translational pig model of intestinal ischemia. The subepithelial enteric glial cell (EGC) network is known to promote epithelial repair by paracrine signaling mechanisms. This EGC network develops postnatally; therefore, we believe this repair defect in neonates is due to an underdeveloped EGC network. In support of this, we hypothesize that EGC inhibition in juveniles will block epithelial barrier repair after ischemic injury mimicking the neonatal phenotype. Ischemia‐injured jejunum of juvenile pigs was recovered ex vivo with and without fluoroacetate (FA), a glial inhibitor. Transepithelial electrical resistance (TEER) was monitored as a measure of barrier function, and tissues were collected for imaging analysis and primary EGC culture. FA inhibited TEER recovery at all tested concentrations (P<0.0001). Histology showed 500μM FA optimally inhibits epithelial repair (P=0.0196) without directly damaging the epithelium (P=0.5509). Cellular metabolism marker c‐fos has been optimized for immunofluorescence in control tissues and ongoing imaging work will validate selective inhibition of EGC metabolism by 500μM FA. In addition, pig EGC isolation and culture has been optimized, so that future work will confirm inhibitory effects of FA on EGC signaling functions in vitro. Understanding the development of glial‐epithelial crosstalk in barrier repair will ultimately guide novel clinical solutions to improve outcomes in neonatal patients affected by intestinal injury.}, number={S1}, journal={FASEB JOURNAL}, publisher={Wiley}, author={Sheridan, Ana and Pridgen, Tiffany and Odle, Jack and Van Landeghem, Laurianne and Blikslager, Anthony and Ziegler, Amanda}, year={2020}, month={Apr} }
 @article{ziegler_pridgen_blikslager_2020, title={Environmental stressors affect intestinal permeability and repair responses in a pig intestinal ischemia model}, volume={8}, ISSN={["2168-8370"]}, url={https://doi.org/10.1080/21688370.2020.1832421}, DOI={10.1080/21688370.2020.1832421}, abstractNote={ABSTRACT The pig is a powerful model for intestinal barrier studies, and it is important to carefully plan animal care and handling for optimal study design as psychological and physiological stressors significantly impact intestinal mucosal barrier function. Here, we report the effects of a period of environmental acclimation versus acute transport stress on mucosal barrier repair after intestinal ischemic injury. Jejunal ischemia was induced in young pigs which had been allowed to acclimate to a biomedical research housing environment or had been transported immediately prior to experimental injury (non-acclimated). Mucosa was then incubated ex vivo on Ussing chambers. In uninjured mucosa, there was no difference in transepithelial electrical resistance (TEER) or epithelial integrity between groups. However, acclimated pigs had increased macromolecular flux as compared to non-acclimated pigs during the first hour of ex vivo incubation. Ischemia induced greater epithelial loss in non-acclimated pigs as compared to acclimated pigs, yet this group achieved greater wound healing during recovery. Non-acclimated pigs had more robust TEER recovery ex vivo following injury versus acclimated pigs. The expression pattern of the tight junction protein claudin-4 was disrupted in acclimated pigs following recovery but showed enhanced localization to the apical membrane in non-acclimated pigs following recovery. Acute transport stress increases mucosal susceptibility to epithelial loss but also primes the tissue for a more robust barrier repair response. Alternatively, environmental acclimation increases leak pathway and diminishes barrier repair responses after ischemic injury.}, number={4}, journal={TISSUE BARRIERS}, publisher={Informa UK Limited}, author={Ziegler, Amanda L. and Pridgen, Tiffany A. and Blikslager, Anthony T.}, year={2020}, month={Oct} }
 @article{kruger_pridgen_taylor_garman_blikslager_2020, title={Lubiprostone protects esophageal mucosa from acid injury in porcine esophagus}, volume={318}, ISSN={["1522-1547"]}, DOI={10.1152/ajpgi.00086.2019}, abstractNote={Esophageal injury from acid exposure related to gastroesophageal reflux disease is a common problem and a risk factor for development of Barrett’s esophagus and esophageal adenocarcinoma. Our previous work highlights the benefits of using porcine esophagus to study human esophageal disease because of the similarities between porcine and human esophagus. In particular, esophageal submucosal glands (ESMGs) are present in human esophagus and proximal porcine esophagus but not in rodent esophagus. Although CFTR is expressed in the ducts of ESMGs, very little is known about CFTR and alternate anion channels, including ClC-2, in the setting of acid-related esophageal injury. After finding evidence of CFTR and ClC-2 in the basal layers of the squamous epithelium, and in the ducts of the ESMGs, we developed an ex vivo porcine model of esophageal acid injury. In this model, esophageal tissue was placed in Ussing chambers to determine the effect of pretreatment with the ClC-2 agonist lubiprostone on tissue damage related to acid exposure. Pretreatment with lubiprostone significantly reduced the level of acid injury and significantly augmented the recovery of the injured tissue ( P < 0.05). Evaluation of the interepithelial tight junctions showed well-defined membrane localization of occludin in lubiprostone-treated injured tissues. Pretreatment of tissues with the Na+-K+-2Cl−cotransporter inhibitor bumetanide blocked lubiprostone-induced increases in short-circuit current and inhibited the reparative effect of lubiprostone. Furthermore, inhibition of ClC-2 with ZnCl2blocked the effects of lubiprostone. We conclude that ClC-2 contributes to esophageal protection from acid exposure, potentially offering a new therapeutic target.}, number={4}, journal={AMERICAN JOURNAL OF PHYSIOLOGY-GASTROINTESTINAL AND LIVER PHYSIOLOGY}, author={Kruger, Leandi and Pridgen, Tiffany A. and Taylor, Ellie R. and Garman, Katherine S. and Blikslager, Anthony T.}, year={2020}, month={Apr}, pages={G613–G623} }
 @article{ziegler_pridgen_mills_gonzalez_van landeghem_odle_blikslager_2018, title={Epithelial restitution defect in neonatal jejunum is rescued by juvenile mucosal homogenate in a pig model of intestinal ischemic injury and repair}, volume={13}, ISSN={1932-6203}, url={http://dx.doi.org/10.1371/journal.pone.0200674}, DOI={10.1371/journal.pone.0200674}, abstractNote={Intestinal ischemic injury results sloughing of the mucosal epithelium leading to host sepsis and death unless the mucosal barrier is rapidly restored. Neonatal necrotizing enterocolitis (NEC) and volvulus in infants is associated with intestinal ischemia, sepsis and high mortality rates. We have characterized intestinal ischemia/ repair using a highly translatable porcine model in which juvenile (6-8-week-old) pigs completely and efficiently restore barrier function by way of rapid epithelial restitution and tight junction re-assembly. In contrast, separate studies showed that younger neonatal (2-week-old) pigs exhibited less robust recovery of barrier function, which may model an important cause of high mortality rates in human infants with ischemic intestinal disease. Therefore, we aimed to further refine our repair model and characterize defects in neonatal barrier repair. Here we examine the defect in neonatal mucosal repair that we hypothesize is associated with hypomaturity of the epithelial and subepithelial compartments. Following jejunal ischemia in neonatal and juvenile pigs, injured mucosa was stripped from seromuscular layers and recovered ex vivo while monitoring transepithelial electrical resistance (TEER) and 3H-mannitol flux as measures of barrier function. While ischemia-injured juvenile mucosa restored TEER above control levels, reduced flux over the recovery period and showed 93±4.7% wound closure, neonates exhibited no change in TEER, increased flux, and a 11±23.3% increase in epithelial wound size. Scanning electron microscopy revealed enterocytes at the wound margins of neonates failed to assume the restituting phenotype seen in restituting enterocytes of juveniles. To attempt rescue of injured neonatal mucosa, neonatal experiments were repeated with the addition of exogenous prostaglandins during ex vivo recovery, ex vivo recovery with full thickness intestine, in vivo recovery and direct application of injured mucosal homogenate from neonates or juveniles. Neither exogenous prostaglandins, intact seromuscular intestinal layers, nor in vivo recovery enhanced TEER or restitution in ischemia-injured neonatal mucosa. However, ex vivo exogenous application of injured juvenile mucosal homogenate produced a significant increase in TEER and enhanced histological restitution to 80±4.4% epithelial coveragein injured neonatal mucosa. Thus, neonatal mucosal repair can be rescued through direct contact with the cellular and non-cellular milieu of ischemia-injured mucosa from juvenile pigs. These findings support the hypothesis that a defect in mucosal repair in neonates is due to immature repair mechanisms within the mucosal compartment. Future studies to identify and rescue specific defects in neonatal intestinal repair mechanisms will drive development of novel clinical interventions to reduce mortality in infants affected by intestinal ischemic injury.}, number={8}, journal={PLOS ONE}, publisher={Public Library of Science (PLoS)}, author={Ziegler, Amanda L. and Pridgen, Tiffany A. and Mills, Juliana K. and Gonzalez, Liara M. and Van Landeghem, Laurianne and Odle, Jack and Blikslager, Anthony T.}, editor={Karhausen, JörnEditor}, year={2018}, month={Aug}, pages={e0200674} }
 @article{krüger_gonzalez_pridgen_mccall_furstenberg_harnden_carnighan_cox_blikslager_garman_et al._2017, title={Ductular and proliferative response of esophageal submucosal glands in a porcine model of esophageal injury and repair}, volume={313}, ISSN={0193-1857 1522-1547}, url={http://dx.doi.org/10.1152/ajpgi.00036.2017}, DOI={10.1152/ajpgi.00036.2017}, abstractNote={ Esophageal injury is a risk factor for diseases such as Barrett’s esophagus (BE) and esophageal adenocarcinoma. To improve understanding of signaling pathways associated with both normal and abnormal repair, animal models are needed. Traditional rodent models of esophageal repair are limited by the absence of esophageal submucosal glands (ESMGs), which are present in the human esophagus. Previously, we identified acinar ductal metaplasia in human ESMGs in association with both esophageal injury and cancer. In addition, the SOX9 transcription factor has been associated with generation of columnar epithelium and the pathogenesis of BE and is present in ESMGs. To test our hypothesis that ESMGs activate after esophageal injury with an increase in proliferation, generation of a ductal phenotype, and expression of SOX9, we developed a porcine model of esophageal injury and repair using radiofrequency ablation (RFA). The porcine esophagus contains ESMGs, and RFA produces a consistent and reproducible mucosal injury in the esophagus. Here we present a temporal assessment of this model of esophageal repair. Porcine esophagus was evaluated at 0, 6, 18, 24, 48, and 72 h and 5 and 7 days following RFA and compared with control uninjured esophagus. Following RFA, ESMGs demonstrated an increase in ductal phenotype, echoing our prior studies in humans. Proliferation increased in both squamous epithelium and ESMGs postinjury with a prominent population of SOX9-positive cells in ESMGs postinjury. This model promises to be useful in future experiments evaluating mechanisms of esophageal repair. }, number={3}, journal={American Journal of Physiology-Gastrointestinal and Liver Physiology}, publisher={American Physiological Society}, author={Krüger, Leandi and Gonzalez, Liara and Pridgen, Tiffany A. and McCall, Shannon J. and Furstenberg, Richard J. and Harnden, Ivan and Carnighan, Gwendolyn E. and Cox, Abigail M. and Blikslager, Anthony and Garman, Katherine S. and et al.}, year={2017}, month={Sep}, pages={G180–G191} }
 @article{jin_pridgen_blikslager_2015, title={Pharmaceutical Activation or Genetic Absence of ClC-2 Alters Tight Junctions During Experimental Colitis}, volume={21}, ISSN={1078-0998}, url={http://dx.doi.org/10.1097/MIB.0000000000000550}, DOI={10.1097/mib.0000000000000550}, abstractNote={Background:We have previously reported that the ClC-2 chloride channel has an important role in regulation of tight junction barrier function during experimental colitis, and the pharmaceutical ClC-2 activator lubiprostone initiates intestinal barrier repair in ischemic-injured intestine. Thus, we hypothesized that pharmaceutical ClC-2 activation would have a protective and therapeutic effect in murine models of colitis, which would be absent in ClC-2−/− mice. Methods:We administered lubiprostone to wild-type or ClC-2−/− mice with dextran sulfate sodium (DSS) or 2, 4, 5-trinitrobenzene sulfonic acid–induced colitis. We determined the severity of colitis and assessed intestinal permeability. Selected tight junction proteins were analyzed by Western blotting and immunofluorescence/confocal microscopy, whereas proliferative and differentiated cells were examined with special staining and immunohistochemistry. Results:Oral preventive or therapeutic administration of lubiprostone significantly reduced the severity of colitis and reduced intestinal permeability in both DSS and trinitrobenzene sulfonic acid–induced colitis. Preventive treatment with lubiprostone induced significant recovery of the expression and distribution of selected sealing tight junction proteins in mice with DSS-induced colitis. In addition, lubiprostone reduced crypt proliferation and increased the number of differentiated epithelial cells. Alternatively, when lubiprostone was administered to ClC-2−/− mice, the protective effect against DSS colitis was limited. Conclusions:This study suggests a central role for ClC-2 in restoration of barrier function and tight junction architecture in experimental murine colitis, which can be therapeutically targeted with lubiprostone.}, number={12}, journal={Inflammatory Bowel Diseases}, publisher={Oxford University Press (OUP)}, author={Jin, Younggeon and Pridgen, Tiffany A. and Blikslager, Anthony T.}, year={2015}, month={Dec}, pages={2747–2757} }