The role of Notch-dependent differentiation of resident fibroblasts in the development of pulmonary fibrosis

Abstract

Background. Molecular mechanisms of the development of pulmonary fibrosis are poorly understood. It is known that differentiation of resident lung cells into myofibroblasts plays a key role in this disease. The search for factors capable of regulating such differentiation is an urgent task. Objective. To evaluate the effect of Notch signaling pathway activation on resident lung fibroblasts by introducing the intracellular domains of each of the 4 Notch receptors (N1-4ICD). Design and methods. Primary cultures of pulmonary fibroblasts from donors (n = 4) were used. Notch-dependent activation of fibroblasts was carried out by introducing lentiviral vectors with/ without sequences of N1-4ICD domains. After 8 days, immunocytochemical staining was performed and the relative expression levels of the PDPN, HOPX, SLUG, SNAIL and ACTA2 genes were evaluated by qPCR. Results. Activation of the Notch signaling pathway by N1-4CD resulted in increased expression of SLUG, SNAIL and ACTA2. The most pronounced effect was observed with the introduction of Notch4-activating sequence. Induction of signaling by the introduction of N1-3ICD activating components contributed to an increase in PDPN expression, with the introduction of N4ICD, an increase in the level of HOPX expression was noted. Conclusion. Activation of each of the 4 intracellular Notch receptor domains is able to trigger the differentiation of resident alveolar fibroblasts into myofibroblasts, which are key players in the development of pulmonary fibrosis.