Evaluation of the Annexin A1 Mimetic Peptide as a Therapeutic Strategy in Liver-Heart-Lung Axis Dysfunction Induced by Monocrotaline in In Vivo and In Vitro Models of Pulmonary Arterial Hypertension

• Grant number: 25/13143-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: November 01, 2025
• End date: October 31, 2026
• Field of knowledge: Biological Sciences - Morphology - Histology
• Principal Investigator: Cristiane Damas Gil
• Grantee: Diego Dias dos Santos
• Supervisor: Stephen Archer
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Institution abroad: Queen's University, Canada
• Associated to the scholarship: 23/16282-7 - ROLE OF ANEXIN A1 IN HEPATOCYTE BIOLOGY: STUDY IN EXPERIMENTAL MODELS OF DIABETES IN VIVO AND IN VITRO, BP.DR

Abstract

Pulmonary arterial hypertension (PAH) is a progressive cardiopulmonary disease characterized by vascular remodeling and high mortality. Its pathophysiology involves metabolic and mitochondrial imbalances in the cells of the lung, right ventricle, and liver. Inflammation triggered by the NLRP3 inflammasome can induce mitochondrial dysfunction. This study aims to evaluate the therapeutic potential of the annexin A1 mimetic peptide, Ac2-26, in modulating NLRP3 inflammasome activation and mitochondrial dysfunction in an experimental PAH model, integrating the liver-lung-heart axes. Male and female Sprague-Dawley rats will be divided into three groups/sex: SHAM (PBS), MCT (60 mg/kg monocrotaline), and MCT+Ac2-26 (MCT + Ac2-26 peptide, 1mg/day). After the establishment of pulmonary hypertension in the MCT-induced PAH model (14 days), the MCT+Ac2-26 group will receive treatment with Ac2-26 for 10 days. The animals' blood will be used for evaluation of cytokines (IL-1¿, IL-4, IL-6, IL-10, IL-18, TNF-¿ and MCP-1), liver biomarkers (AST, ALT, alkaline phosphatase, GGT, bilirubin and qRT-PCR (mtDNA ). The liver, RV and lung will be processed for histology (H&E and picrosirius), immunofluorescence (AnxA1, FPR1, FPR2, NLRP3, CD68 (?), mtDNA (?) and Tomm20), and submitted to flow cytometry to evaluate the macrophage profile. The liver and heart will be frozen for further molecular analysis using western blotting (Mfn1 and 2, Drp1, NLRP3, Caspase-1, IL-1¿ and B-actin). Subsequently, the in vitro experimental model will consist of isolating peritoneal macrophages and hepatocytes from the animals in the groups SHAM and MCT, which will be co-cultured and subsequently treated with the mimetic peptide Ac2-26, evaluating the mitochondrial profile and the possible therapeutic target of the peptide in PAH. This study aims to evaluated the role of the Annexin A1 protein mimetic peptide (Ac2-26) as a therapeutic target in the liver-heart-lung axis and mitochondrial dysfunctions associated with MCT-induced PAH.