ave-0991 and Pulmonary-Fibrosis

Early pulmonary fibrosis is the leading cause of poor prognosis in patients with acute respiratory distress syndrome (ARDS). However, whether the renin-angiotensin system (RAS) can serve as a therapeutic target is unknown. In this study, an animal model of early pulmonary fibrosis was established via the LPS three-hit regimen. Afterwards, the animals were treated with intraperitoneal injections of Ang-(1-7), AVE0991, or A779 once per day for 20 days. The plasma and BALF AngII levels of the animals were increased, while there were no significant changes in Ang-(1-7) levels in lung tissue after LPS treatment. Furthermore, the AT1R protein levels were significantly increased and the Mas levels were significantly decreased on days 14 and 21. Administration of Ang-(1-7) downregulated LPS-induced AT1R mRNA expression, which was upregulated by A779. The expression of Mas mRNA responded in the opposite direction relative to AT1R. Moreover, LPS caused decreased levels of Mas and E-cadherin and increased AT1R, Vimentin, and Src phosphorylation levels. Ang-(1-7) or AVE0991 blocked these effects but was counteracted by A779 treatment. Our findings suggested that AngII and AT1R levels exhibit opposite dynamic trends during LPS-induced early pulmonary fibrosis, as do Ang-(1-7) and Mas. Ang-(1-7) exerts protective effects against early pulmonary fibrosis, mainly by regulating the balance between AngII and AT1R and between Ang-(1-7) and Mas and by inhibiting Src kinase activation.

Topics: Angiotensin I; Angiotensin II; Animals; Bronchoalveolar Lavage Fluid; Cadherins; Drug Evaluation, Preclinical; Imidazoles; Lipopolysaccharides; Lung; Peptide Fragments; Proto-Oncogene Mas; Proto-Oncogene Proteins; Pulmonary Fibrosis; Random Allocation; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Receptors, G-Protein-Coupled; Transforming Growth Factor beta; Vasodilator Agents; Vimentin