Evaluation of glycosaminoglycans role in antimicrobial peptides entrance across cell membrane

• Grant number: 17/03611-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2017
• End date: February 28, 2019
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Edgar Julian Paredes-Gamero
• Grantee: Letícia Paulino Sperandio
• Host Institution: Pró-Reitoria Acadêmica. Universidade de Mogi das Cruzes (UMC). Campus da Sede Mogi das Cruzes. Mogi das Cruzes , SP, Brazil

Abstract

Antimicrobial peptides (AMPs) have many biological actions and have raised enormous scientific interest by their biological actions. Extracted from almost all multicellular taxons, the AMPs showed beside antimicrobial activity, immune regulation, and cancer cytotoxicity. Among the AMPs, there are peptides with b-hairpin structure, such as gomesin, protegrin, tachyplesin, and polyphemusin. Several reports have shown the anti-tumor capacity of these peptides, with b-hairpin structure, have a variety of cellular mechanisms. The aspects of molecular and cellular mechanisms of action of these AMPs are under study, and apparently involve the entry of the AMPs through the plasma membrane. However, neither the AMP entrance mechanism nor the participation of glycosaminoglycans (GAGs) in this process were determined. Thus, the goal of this study is to investigate the entrance mechanisms of AMPs into tumor cells and the participation of GAGs in this process. Hence, the interaction process between the AMPs (gomesin, protegrin, tachyplesin, and polyphemusin) and GAGs will be determined; specific changes in GAG heparin will be performed and alterations in interaction process will be monitored. We will evaluate, in cell culture, if GAGs modifications (inhibition of proteoglycan chains, desulfation, competition assay) alter the entrance and the cytotoxic effect of AMPs, using as model the human tumor lineage HeLa. In addition, we will study if pharmacological modulators of endocytosis modify the entry of AMPs in our tumor cell model using flow cytometry, transmission electron microscopy and confocal microscopy. (AU)