Study on the effects of two phospholipases A2 (MT-III and BthTx-II) isolated from Bothrops<\\i> snake venoms in vascular smooth muscle cells: lipid droplets formation and mechanisms involved.

Author(s)

Karina Cristina Giannotti

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2017-05-10

Examining board members

Catarina de Fatima Pereira Teixeira; Sandra Helena Poliselli Farsky; Joilson de Oliveira Martins; Anderson de Sá Nunes; Vanessa Olzon Zambelli

• Advisor: Catarina de Fatima Pereira Teixeira

Abstract

Bothrops snake venom secreted phospholipases A2 (sPLA2s) share structural and functional features with mammalian GIIA sPLA2s, which are highly expressed during inflammatory diseases, such as atherosclerosis. In this disease, vascular smooth muscle cells (VSMCs) are loaded with lipid droplets (LDs) differentiating into foam cells. However, the role of these enzymes in this process is still unknown. In this study the effects of snake venom PLA2s MT-III with catalytic activity and BthTx-II, devoid of catalytic activity in VSMCs, with focus on LDs formation and mechanisms involved were investigated. Results here obtained show that both MT-III and BthTx-II induce formation of foam VSMCs and recruit distinct factors of synthesis and storage of lipids in these cells. In this condition, LDs constitute sites for synthesis of prostaglandins. Moreover, MT-III showed the ability to modulate VSMCs functions, leading them to a phenotipic switch to macrophage-like cells. In addition, the catalytic activity is not relevant to sPLA2-induced LDs formation. (AU)

• FAPESP's process: 13/22610-5 - Studies on the effects of a phospholipase A2 isolated from Bothrops asper snake venom on smooth muscle vascular cells in culture. Formation of Lipid Droplets and mechanisms involved in this effect.
• Grantee: Karina Cristina Giannotti
• Support Opportunities: Scholarships in Brazil - Doctorate