Epithelial cell entry

"Epithelial cell entry" does not correspond to a specific molecular target but evokes processes where pathogens or substances cross epithelial barriers via transcytosis, paracellular routes, or disrupted tight junctions, as seen in intestinal or respiratory epithelia. Epithelial tissues form selective barriers using cell junctions (tight junctions, adherens junctions, desmosomes) and mucus layers to regulate nutrient uptake while blocking microbes, with failures linked to infections or inflammation. In mechanobiology contexts, epithelial monolayers exhibit geometry-driven stress gradients activating Cx43 hemichannels and Piezo channels, leading to depolarization, Yap/Taz nuclear localization, and patterned proliferation, though this is a tissue-level phenomenon, not a single receptor. No approved drugs directly target this concept; therapeutic strategies instead focus on related molecules like tight junction modulators for drug delivery or antimicrobials blocking pathogen entry. Overall, it lacks the specificity of validated targets like receptors (e.g., ACE2 for SARS-CoV-2 entry) and is unsuitable for structured drug discovery databases.