Cathelicidin influence on pathological activation of Wnt pathway in murine model of hypersensitivity pneumonitis

Abstract

Introduction and Objective. Cathelicidin (CRAMP) is a defence peptide with a wide range of biological responses including antimicrobial, immunomodulatory and wound healing. Furthermore, our previous studies suggested the possibility of using cathelicidin in the prevention and treatment of pulmonary fibrosis in the course of hypersensitivity pneumonitis (HP). The molecular mechanism of CRAMP action, however, was not fully explained. Due to the fact that several studies indicated the Wnt signals pathways as a key player in wound healing and fibrosis, studies focused on this pathway in order to explain the above-mentioned therapeutic potential of cathelicidin in HP development. Materials and method. The study was conducted in a murine model of HP, wherein lung fibrosis is induced in mice strain C57BL/6J by chronic exposure to saline extract of P. agglomerans (SE-PA). Cathelicidin was administered in the an form of aerosol during HP development. Changes in the expression of genes and proteins involved in signals transduction in the Wnt/β-Catenin pathway were examined in lung tissue homogenates by RealTime PCR and Western Blotting, respectively. Results. The study revealed that cathelicidin decreased the elevated level of components of the Wnt/β-Catenin pathway (Ctnnd1/β-Catenin, Wnt1/WNt1, Wnt3a/Wnt3a, Wnt5a/Wnt5a) in the murine model of HP. Furthermore, CRAMP administered together with SE-PA inhibited the transcription function of β-catenin, leading to a decrease in abnormal expression of profibrotic molecules: Cyclin D1, c-Myc, MMP-7. Nevertheless, cathelicidin was not able to completely neutralize the negative changes induced by SE-PA. Conclusions. The study demonstrated the beneficial effect of exogenous cathelicidin on signals transduction in the Wnt/β-Catenin pathway, which may prevent fibrosis development in HP.

Cathelicidin Treatment Silences Epithelial–Mesenchymal Transition Involved in Pulmonary Fibrosis in a Murine Model of Hypersensitivity Pneumonitis

“…Gene expression evaluation has been described previously [ 62 ]; nevertheless, what should be mentioned are the TaqMan Gene Expression Assays (sets of probes and primers) used in the research: Mm00725412_s1 for Acta2 ; Mm02619580_g1 for Actb ; Mm01247357_m1 for Cdh1 ; Mm01162497_m1 for Cdh2 ; Mm01334599_m1 for Ctnnd1 ; Mm01256744_m1 for Fn1 ; Mm00476361_m1 for Nfkb1 ; Mm00500912_m1 for Ocln ; Mm01178820_m1 for Tgfb1 ; Mm00441533_g1 for Snail1 ; Mm01333430_m1 for Vim ; Mm00495564_m1 for Zeb1 ; Mm00497196_m1 for Zeb2 . Relative expression was calculated using the efficiency method (relative advanced quantification) and normalized to the expression of Actb .…”

“…Examination of protein expression has been described previously [ 62 ]. The investigation has been conducted using primary antibodies directed against β-actin, β-catenin, E-cadherin, N-cadherin, Snail, vimentin (Cell Signaling Technology, Danvers, MA, USA), α-smooth muscle actin, fibronectin, occludin, NFκB, TGFβ, ZEB1, and ZEB2 (ThermoFisher Scientific, Waltham, MA, USA).…”