DNAJB12 co-chaperone in Protein Disulfide Isomerase-dependent activation of Nox NADPH oxidases in vascular cells

• Grant number: 24/15259-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: August 31, 2025
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Francisco Rafael Martins Laurindo
• Grantee: Carlos Samuel Duarte dos Santos
• Host Institution: Instituto do Coração Professor Euryclides de Jesus Zerbini (INCOR). Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated research grant: 13/07937-8 - Redoxome - Redox Processes in Biomedicine, AP.CEPID

Abstract

Among the several factors that regulate the expression and activation of Nox NADPH oxidases, the main enzymatic pathway of oxidant generation for cell signaling purposes, our group investigates in detail the effect of Protein Disulfide Isomerase (PDI), but the mechanisms of regulatory PDI effects are not precisely elucidated. An important open question is to understand how PDI, a protein from the endoplasmic reticulum lumen, physically interacts and functionally affects Noxes, which are proteins from the cytoplasm and plasma membrane. Our hypothesis is that the induction of mechanisms of PDI cytosolic translocation via the co-chaperone DNAJB12 contributes to the activation of Noxes via PDI. Our main aim is to investigate the effect of DNAJB12 in the activation of Nox1 and Nox4 dependent on PDI in vascular smooth muscle cells. Specific aims are: 1) To investigate, by loss of function experiments, if silencing of DNAJB12 prevents the activation of Nox1 in response to angiotensin-II or Nox4 in response to serum deprivation; 2) To assess the effects of forced overexpression of DNAJB12in Nox1 or Nox4 activation; 3) To investigate how the gain of function of DNAJB12 alters cell migration and differentiation via Noxes and PDIA1. Elucidating mechanisms connecting Nox NADPH oxidases to PDI may have broad implications to understand the pathophysiology of several diseases.