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| Author(s): |
Mariana Sayuri Berto Udo
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2017-12-07 |
| Examining board members: |
Tania Marcourakis;
Christiano Marcello Vaz Barbosa;
Renata Gorjão;
Andréa da Silva Torrão;
Rodrigo Portes Ureshino
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| Advisor: | Tania Marcourakis; Silvya Stuchi Maria Engler |
| Abstract | |
Cocaine market is increasing all around the world. In Brazil it is estimated that almost 2 million people make usage of this substance which 370 thousand people use the crack form. Cocaine is a psychostimulant with large potential for abuse and the smokable form produces more health problems than the other routes of use, mainly in the cognitive field related to compromising attention, memory and decision take. The crack users are exposed to both volatized cocaine and their pyrolysis products, which the main product is the anhydroecgonine methyl ester (AEME). Considering that the cognitive disturbs could be related to neurons death, the memory functions are also related to the hippocampal functions, and little is known about the AEME neurotoxicity or even the combination of cocaine and AEME in cell fate, our study aims to characterize the time and pathways related to the hippocampal neurotoxicity induced by 2 mM of cocaine, 1 mM of AEME and the association (C + A) of both substances during 3 h, 6 h and 12 h of exposure. Our results showed that cocaine and AEME increased enzymatic activity (MTT test) in 3 h but it reversed during 12 h of exposure. Moreover, AEME increased cell permeability in 6 h keeping it until 12 h. Although theses early alterations, both substances activated caspase -8 after 12 h when early apoptosis was also observed by the FS externalization. Cocaine activated the autophagic process at 3 h increasing the LC3 II quantification, but decreased the number of cell with acid vesicle at 6 h and 12 h, suggesting neuronal death due to failure in the autophagic flux. AEME showed increased in cell number with acid vesicle only in 3 h which returned after 6 h suggesting that the autophagic process gave place to the apoptotic program starting from the extrinsic pathway. The association of cocaine and AEME was shown more neurotoxic than them alone, decreasing the number of integral cells after 3 h, activating caspase -8 and promoting FS externalization after 6 h without involving the autophagy. In addition, taking the C + A morphology in 6 h, where it was observed increasing of nucleus and soma size that became pyknotic at 12 h, we suggest that the neuronal death could occur by necroptosis because this composition activated caspase -8 and resulted in necrotic like morphology. Thus, we conclude that cocaine- and AEME-induced apoptosis neuronal death starts in 12 h of exposure by the extrinsic pathway and the association of both substances is more neurotoxic than they alone, starting earlier after 6 h and resulting in a necrotic-like morphology. (AU) | |
| FAPESP's process: | 13/20952-6 - Neurotoxicity of anhydroecgonine methyl ester in vitro: apoptosis death pathway caracterization and the autophagic process involvent |
| Grantee: | Mariana Sayuri Berto Udo |
| Support Opportunities: | Scholarships in Brazil - Doctorate |