A new PDI activity assay in human plasma

• Grant number: 17/19866-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2018
• End date: January 31, 2019
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Francisco Rafael Martins Laurindo
• Grantee: Nathalia Tenguan Silva
• 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

Protein Disulfide Isomerase (PDI) is a dithiol disulfide oxidoreductase chaperone of thioredoxin superfamily that catalyzes the formation and isomerization of disulfide bonds as an essential functional component of protein synthesis and processing. Although localized primarily in the endoplasmic reticulum, PDI has been reported in other intracellular locations and on the cell surface. PDI is secreted by several cell types and it plays an important role in several biological processes, such as thrombus formation after vascular injury, platelet activity, and vascular remodeling. Some studies have demonstrated the role of PDI as thiol reductase in the activation of plasma proteins involved in the thrombogenic process, when PDI is an important and innovative antithrombotic target. However, the existence of circulating PDI under normal conditions is controversial and its existence has been questioned. Immunoassays performed in our group have shown the presence of nanomolar concentrations of PDI in healthy subjects as well as in patients. However, plasma PDI activity has not been quantified yet. The aim of this study is to develop an assay to measure thiol reductase activity of PDI in plasma, adapting methodology already validated in other systems. Here, we are going to use the fluorescence probe di-Eosin-GSSG, already characterized for the measurement of PDI thiol reductase activity in nanomolar concentrations. The main challenge will be to refine the assay for measurement of PDI thiol reductase activity at relatively low concentrations. The validation of this assay might contribute with a new tool to investigate the physiological and pathological PDI role in the plasma fraction under several conditions. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SANTOS DE OLIVEIRA, PERCILLIA VICTORIA; GARCIA-ROSA, SHEILA; AZEVEDO SACHETTO, ANA TERESA; SOARES MORETTI, ANA IOCHABEL; DEBBAS, VICTOR; DE BESSA, TIPHANY CORALIE; SILVA, NATHALIA TENGUAN; PEREIRA, ALEXANDRE DA COSTA; MARTINS-DE-SOUZA, DANIEL; SANTORO, MARCELO LARAMI; et al. Protein disulfide isomerase plasma levels in healthy humans reveal proteomic signatures involved in contrasting endothelial phenotypes. REDOX BIOLOGY, v. 22, APR 2019. (17/25588-1, 18/07511-4, 17/19866-9, 14/20595-1, 13/08711-3, 13/25177-0, 14/10068-4, 13/07937-8)