Outline the signaling network triggered by treatment with Captopril and highlight the effects that are not explained only in terms of blocking the catalytic activity of ACE

• Grant number: 21/06091-4
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): September 01, 2021
• Effective date (End): August 31, 2023
• Field of knowledge: Biological Sciences - Biochemistry - Enzymology
• Principal Investigator: Dulce Elena Casarini
• Grantee: Rodrigo Yokota
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated research grant: 17/17027-0 - Hormonal systems in renal and cardiovascular diseases: from cell biology to new physiological paradigms with advances for therapeutics, AP.TEM

Abstract

The Renin-Angiotensin System (RAS) is a hormonal system associated with hydroelectrolytic homeostasis and blood pressure control, and its regulation is important in the control of renal and cardiovascular diseases. In the classical RAS pathway, the peptide angiotensin II (Ang II) is the main and most potent biologically active product of the system generated from the decapeptide Angiotensin I (Ang I) through central, renal and vascular mechanisms, being the converting enzyme of Angiotensin I (ACE) is responsible for this cleavage and is considered to be the key point of this system. This complex hormonal system, which is extremely important in the physiological regulation of blood pressure, was originally defined as a circulating system, but several studies show that several tissues express the complete RAS and indicate the existence of an intracellular system involved in cell function and signaling. Recent studies show that the RAS acts intracellularly on several cell types and with different components. RAS dysregulation is an important factor in the development and progression of cardiovascular diseases and other pathologies. Experimental and clinical evidences indicate that RAS blockade with ACE inhibition or AT1 receptor antagonists is an effective treatment for the control of Hypertension, attenuation of Diabetic Kidney Damage, contributing to the improvement of heart failure. Furthermore, the importance of local RAS in monocytes, cardiomyocytes, vascular wall and adipose tissue has also been highlighted. ACE plays a fundamental role in the RAS and several studies have shown the benefit of using inhibitors for this enzyme. All ACE inhibitors act by binding to the ACE active site and interfere with the enzyme's ability to bind and cleave its substrates, that is, Ang I and BK. ACE inhibitors are structurally heterogeneous differing in specific ligands, and consequently in the duration of ACE inhibition. They also differ in other pharmacokinetic properties, such as absorption, protein binding, and metabolic disposition. In addition to the effects mentioned above, recently the use of ACEi has also been associated with the activation of signaling pathways, thus suggesting that ACE may act as a signal transducer molecule. Data from our laboratory in CHO cells permanently transfected with the ACE gene (CHO-ACE) confirm the activation of the JNK signaling pathways and show for the first time the activation of the ERK1/2 signaling pathway after stimulation with captopril and enalapril. However, a complete mapping of differentially regulated proteins after the use of ACE inhibitors is not clear. Thus, our aim is to study the proteins that are differentially regulated when CHO-ACE cells are treated with different ACE inhibitors, starting our study with captopril. Thus, our results will allow us to delineate the signaling network triggered by this enzyme inhibitor, and will be able to highlight the effects that are not explained only in terms of blocking the enzyme's catalytic activity. With these results in hand, we will plot an interactome comparing our targets with those known to be involved in Hypertension and other pathologies involving the RAS. Thus, we will be able to better understand the role of ACE as a signal transducer molecule in this context. (AU)