{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T15:18:46Z","timestamp":1783696726366,"version":"3.55.0"},"reference-count":46,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,3,1]],"date-time":"2023-03-01T00:00:00Z","timestamp":1677628800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["GU 405\/14-1"],"award-info":[{"award-number":["GU 405\/14-1"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["08\/2022 GI"],"award-info":[{"award-number":["08\/2022 GI"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]},{"name":"University Medical Center Giessen and Marburg","award":["GU 405\/14-1"],"award-info":[{"award-number":["GU 405\/14-1"]}]},{"name":"University Medical Center Giessen and Marburg","award":["08\/2022 GI"],"award-info":[{"award-number":["08\/2022 GI"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Enzymatic modification of gliadin peptides by human transglutaminase 2 (TG2) is a key mechanism in the pathogenesis of celiac disease (CD) and represents a potential therapeutic target. Recently, we have identified the small oxidative molecule PX-12 as an effective inhibitor of TG2 in vitro. In this study, we further investigated the effect of PX-12 and the established active-site directed inhibitor ERW1041 on TG2 activity and epithelial transport of gliadin peptides. We analyzed TG2 activity using immobilized TG2, Caco-2 cell lysates, confluent Caco-2 cell monolayers and duodenal biopsies from CD patients. TG2-mediated cross-linking of pepsin-\/trypsin-digested gliadin (PTG) and 5BP (5-biotinamidopentylamine) was quantified by colorimetry, fluorometry and confocal microscopy. Cell viability was tested with a resazurin-based fluorometric assay. Epithelial transport of promofluor-conjugated gliadin peptides P31-43 and P56-88 was analyzed by fluorometry and confocal microscopy. PX-12 reduced TG2-mediated cross-linking of PTG and was significantly more effective than ERW1041 (10 \u00b5M, 15 \u00b1 3 vs. 48 \u00b1 8%, p &lt; 0.001). In addition, PX-12 inhibited TG2 in cell lysates obtained from Caco-2 cells more than ERW1041 (10 \u00b5M; 12 \u00b1 7% vs. 45 \u00b1 19%, p &lt; 0.05). Both substances inhibited TG2 comparably in the intestinal lamina propria of duodenal biopsies (100 \u00b5M, 25 \u00b1 13% vs. 22 \u00b1 11%). However, PX-12 did not inhibit TG2 in confluent Caco-2 cells, whereas ERW1041 showed a dose-dependent effect. Similarly, epithelial transport of P56-88 was inhibited by ERW1041, but not by PX-12. Cell viability was not negatively affected by either substance at concentrations up to 100 \u00b5M. PX-12 did not reduce TG2 activity or gliadin peptide transport in confluent Caco-2 cells. This could be caused by rapid inactivation or degradation of the substance in the Caco-2 cell culture. Still, our in vitro data underline the potential of the oxidative inhibition of TG2. The fact that the TG2-specific inhibitor ERW1041 reduced the epithelial uptake of P56-88 in Caco-2 cells further strengthens the therapeutic potential of TG2 inhibitors in CD.<\/jats:p>","DOI":"10.3390\/ijms24054795","type":"journal-article","created":{"date-parts":[[2023,3,2]],"date-time":"2023-03-02T03:29:00Z","timestamp":1677727740000},"page":"4795","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Inhibition of Transglutaminase 2 as a Therapeutic Strategy in Celiac Disease\u2014In Vitro Studies in Intestinal Cells and Duodenal Biopsies"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1531-3627","authenticated-orcid":false,"given":"Sebastian","family":"Stricker","sequence":"first","affiliation":[{"name":"Department of Pediatrics, Justus-Liebig-University Giessen, 35392 Giessen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jan","family":"de Laffolie","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Justus-Liebig-University Giessen, 35392 Giessen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Klaus-Peter","family":"Zimmer","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Justus-Liebig-University Giessen, 35392 Giessen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Silvia","family":"Rudloff","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Justus-Liebig-University Giessen, 35392 Giessen, Germany"},{"name":"Institute of Nutritional Science, Justus-Liebig-University Giessen, 35392 Giessen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"823","DOI":"10.1016\/j.cgh.2017.06.037","article-title":"Global Prevalence of Celiac Disease: Systematic Review and Meta-analysis","volume":"16","author":"Singh","year":"2018","journal-title":"Clin. 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