Expression of p-defensin-1 in rat colon tissue

Introduction. At present, signaling pathways involved in the development of innate and adaptive immune responses and comprising, inter alia, the interaction of pattern-recognizing receptors, such as TLR, with antimicrobial peptides associated with inflammation, proliferation, production of cytokines and chemokines, are actively studied. Among them, there is f-defensin, the localization of which in rat colon tissue and expression changes under bacterial endotoxemia are still poorly understood. At the same time, an important problem in the study of neuroimmune interactions is to reveal potential relationships between the production of endogenous defensins and TLR expression, in particular, by enteric neurons. The aim of the study. In the present study, we investigated the localization of f-defensin-1 (rBD1) in rat colon tissue under normal conditions and on the model of bacterial endotoxemia induced by Escherichia coli lipopolysaccharide (LPS). Results. By means of immunohistochemistry, we have shown rBD1 to be mainly localized in the submucous layer of the rat colon and characterized by constitutive and inducible expression. Bacterial endotoxemia provides a statistically significant increase in rBD1 expression after 6 hours and 24 hours following LPS administration. Conclusion. Despite the lack of convincing data verifying the expression of f-defensin-1 by enteric neurons, we cannot exclude endogenous inducible defensins upregulation following LPS administration through signaling pathways associated with TLR4, which is expressed by rat colon sensory neurons.

TLR4, antimicrobial peptides, f-defensin-1, TLR4, enteric neurons