Efeito antitumoral de um inibidor de PLA2 de Crotalus durissus collilineatus (γCdcPLI) pela modulação da via PI3K/Akt em células de câncer de mama

Phospholipases A2 (PLA2s) overexpression is closely associated with the malignant potential of breast cancers. Here, we showed for the first time the antitumoral effects of γCdcPLI, a PLA2 inhibitor from Crotalus durissus collilineatus via PI3K/Akt pathway on MDA-MB-231 cell. Firstly, γCdcPLI was more cytotoxic to MDA-MB-231 breast cancer cells than other cell lines (MCF-7, HeLa, PC3 and A549) and did not affect the viability of non-tumorigenic breast cell (MCF 10A). In addition, γCdcPLI induced modulation of important mediators of apoptosis pathways such as p53, MAPK-ERK, BIRC5 and MDM2. γCdcPLI decreased MDA-MB-231 adhesion, migration and invasion. Interestingly, the γCdcPLI also inhibited the adhesion and migration of endothelial cells and blocked angiogenesis by inhibiting tube formation by HUVECs in vitro and sprouting elongation on aortic ring assay ex vivo. Moreover, γCdcPLI reduced the production of vascular endothelial growth factor (VEGF). γCdcPLI was also able to decrease PGE2 levels in MDA-MB-231 and inhibited gene and protein expression of the PI3K/Akt pathway. Furthermore, γCdcPLI inhibited the proinflammatory effects of BnSP-7, a PLA2 Bothrops pauloensis of snake venom. Thus the effects of γCdcPLI in PI3K / AKT pathway can be correlated to a possible interaction between the inhibitor and endogenous PLA2s. Thus, we concluded that γCdcPLI showed in vitro antitumoral, antimestatatic and anti-angiogenic potential effects and could be an attractive approach for futures studies in cancer therapy.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas GeraisINCT - Instituto Nacional de Ciência e Tecnologia de NanobiofarmacêuticaTese (Doutorado)A alta expressão de fosfolipases A2 (PLA2) está diretamente associada ao potencial de malignidade do câncer de mama. Neste trabalho mostramos pela primeira vez o efeito antitumoral do γCdcPLI, um inibidor de PLA2 isolado do soro da serpente Crotalus durissus collilineatus, pela via do PI3K/Akt em células MDA-MB-231. Primeiramente, o γCdcPLI foi mais citotóxico para as células de câncer de mama MDA-MB-231 do que para outras linhagens celulares (MCF-7, HeLa, PC3 e A549) e não afetou a viabilidade das células de mama não-tumorais (MCF 10A). Além disso, o γCdcPLI induziu a modulação de importantes mediadores da via de apoptose, como o p53, MAPK/ERK, BIRC5 e MDM2. Interessantemente, o γCdcPLI inibiu a adesão e migração de células endoteliais humanas e bloqueou a angiogênese por diminuir a formação de vasos em células HUVEC (in vitro) e formação de prolongamentos celulares em modelo ex vivo de fragmento de aorta, além de reduzir a produção de fator de crescimento endotelial (VEGF). O γCdcPLI foi também capaz de diminuir os níveis de PGE2 nas células MDA-MB-231 e inibiu a expressão de genes e proteínas da via de sinalização do PI3K/Akt. Além disso, o γCdcPLI inibiu os efeitos pro-inflamatórios da BnSP-7, uma PLA2 isolada da peçonha de Bothrops pauloensis. Assim, os efeitos de γCdcPLI na via PI3K/AKT podem ser correlacionados com uma possível interação entre o inibidor e as PLA2 endógenas. Assim, concluímos que o γCdcPLI apresenta um efeito antitumoral, antimestático e antiangiogênico in vitro e possui um potencial para o uso como modelo farmacológico para terapia antitumoral

Mechanistic Insights into the Anti-angiogenic Activity of Trypanosoma cruzi Protein 21 and its Potential Impact on the Onset of Chagasic Cardiomyopathy

Chronic chagasic cardiomyopathy (CCC) is arguably the most important form of the Chagas Disease, caused by the intracellular protozoan Trypanosoma cruziit is estimated that 10-30% of chronic patients develop this clinical manifestation. The most common and severe form of CCC can be related to ventricular abnormalities, such as heart failure, arrhythmias, heart blocks, thromboembolic events and sudden death. Therefore, in this study, we proposed to evaluate the anti-angiogenic activity of a recombinant protein from T. cruzi named P21 (rP21) and the potential impact of the native protein on CCC. Our data suggest that the anti-angiogenic activity of rP21 depends on the protein's direct interaction with the CXCR4 receptor. This capacity is likely related to the modulation of the expression of actin and angiogenesis-associated genes. Thus, our results indicate that T. cruzi P21 is an attractive target for the development of innovative therapeutic agents against CCC.Univ Fed Sao Paulo, Escola Paulista Med, Departamento Microbiol Imunol Parasitol, BR-05508 Sao Paulo, SP, BrazilUniv Fed Uberlandia, Inst Ciencias Biomed, Dept Imunol, Lab Tripanosomatideos, Uberlandia, MG, BrazilUniv Fed Uberlandia, Inst Genet & Bioquim, Lab Bioquim & Toxinas Animais, Uberlandia, MG, BrazilCeTICS, Inst Butantan, Sao Paulo, BrazilUniv Fed Uberlandia, Fac Med, Centro Referencia Nacl Dermatol Sanitaria Hanseni, Lab Patol Mol & Biotecnol, Uberlandia, MG, BrazilUniv Fed Uberlandia, Inst Ciencias Biomed, Dept Immunol, Lab Osteoimunol & Imunol Tumores, Uberlandia, MG, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Departamento Microbiol Imunol Parasitol, BR-05508 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Departamento Microbiol Imunol Parasitol, BR-05508 Sao Paulo, SP, BrazilWeb of Scienc

Caracterização bioquímica e funcional de um inibidor de Fosfolipase A2 do tipo γ isolado do soro de Crotalus durissus collilineatus

Some animals have a natural resistance to toxic effects induced by snake venom due to presence of natural endogenous inhibitors in their plasma. Snake venom contains inhibitors of phospholipase A2 (PLA2) that inhibit the enzymatic and pharmacological activities of PLA2. In this work we show the isolation, structural and biochemical characterization of a new PLA2 inhibitor from Crotalus durissus colillineatus (Cdc) snake serum by two chromatographic steps. Initially, the Cdc serum was applied to a column of ion exchange Q-Sepharose Fast Flow, producing six peaks of absorbance at A280nm (Q1 to Q6). Subsequently, Q4 fraction (best results to inhibition) was applied to affinity chromatography with immobilized HiTrap NHS-BnSP-7. This fractionation resulted in two fractions (NHS-1 and NHS-2) the second fraction contained the inhibitor, named γCdcPLI. The molecular mass of γCdcPLI determined by MALDI-TOF was 22.3kDa and the primary partial structure obtained by Edman and peptide mass fingerprinting (PMF) MS (MALDI-TOF \\ TOF), showed similarity when compared with the sequences of other related inhibitors. The secondary structure was evaluated for circular dichroism and showed approximately 22% alpha helix and 29% beta sheets.These studies of interaction have also indicated no significant changes in secondary structure to γCdcPLI and BnSP-7. The results obtained by analysis of dynamic light scattering (DLS) showed that the inhibitor has in oligomerization variation, according to temperature and when dissolved in H2O or PBS. γCdcPLI was able to inhibit the enzymatic, with 100% to inhibition. Cytotoxicity was assayed on Murine endothelial cell line derived from thymus hemangioma- tEnd to MTT and myotoxicity was measuring by creatine kinase (CK) showed inhibition too, but in this case the inhibition was independent dose. Structural and functional studies of this inhibitor may contribute to understanding the mechanisms of action of PLA2 inhibitors. In addition, these studies may serve as starting point for investigating the potential of these inhibitors for the treatment of snake bite or inflammatory diseases.Fundação de Amparo a Pesquisa do Estado de Minas GeraisMestre em Genética e BioquímicaAlguns animais apresentam uma resistência natural aos efeitos tóxicos induzidos por peçonha de serpentes, isto se deve a presença de inibidores naturais endógenos em seu plasma. Dentre estes, destacam-se os inibidores de fosfolipases A2 (PLA2), os quais são capazes de inibir as atividades enzimáticas e farmacológicas de várias PLA2s de peçonhas ofídicas. No presente trabalho, foi demonstrado o isolamento, a caracterização bioquímica e estrutural de um inibidor de PLA2, o qual foi isolado do soro da serpente Crotalus durissus collilineatus (Cdc) por dois passos cromatográficos. Inicialmente o soro de Cdc foi aplicado em uma coluna de troca-iônica Q-Sepharos, produzindo seis picos de absorbância a A280nm denominados (Q1 a Q6). Posteriormente, a fração Q4, que demonstrou melhores resultados de inibição foi submetida a uma cromatografia de afinidade NHS Hitrap imobilizada com uma PLA2-símile (BnSP-7). Deste fracionamento resultaram duas frações denominadas de NHS-1 e NHS-2, sendo que a fração NHS-2 representa o inibidor de PLA2 denominado γCdcPLI. A massa molecular do inibidor determinada por (MALDI-TOF) foi de 22.34 kDa e a sequência primária parcial determinada por Edman e Peptide Mass Fingerprinting (PMF) em MS (MALDI-TOF\\TOF) mostrando similaridade com outros inibidores do tipo γ. As análises da estrutura secundária realizada por dicroísmo circular revelaram aproximadamente 22% de alfa hélices e 29% de folhas beta. Estes estudos também indicaram que não houve alteração significativa na conformação tanto do γCdcPLI ou da PLA2-símile BnSP-7. Os resultados obtidos por análises de espalhamento de luz dinâmico demonstraram que o inibidor possui comportamento de oligomerização mediante variação de temperatura e quando dissolvido em H2O ou PBS. O γCdcPLI foi capaz de inibir as atividades enzimática com resultado de 100% na razão 1:5 (m/m) frente as PLA2 utilizadas, miotóxica por dosagem de CK e citotóxica por MTT em células tEnd com característica de ser dose não dependente. Estudos estruturais e funcionais deste inibidor poderão contribuir para a compreensão dos mecanismos de ação dos inibidores de PLA2s, bem como na investigação de seu uso como auxiliar no tratamento do envenenamento ofídico ou doenças inflamatórias

Isolation and biochemical characterization of a gamma-type phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum

In the present work, we describe the isolation and partial structural and biochemical characterization of the first phospholipase A(2) inhibitor (gamma PLI) from Crotalus durissus collilineatus (Cdc) snake serum. Initially, the Cdc serum was subjected to a Q-Sepharose ion exchange column, producing six peaks at 280 nm absorbance (Q1-Q6). Subsequently, Q4 fraction was submitted to affinity chromatography with immobilized PLA(2) BnSP-7, a step that resulted in two fractions (NHS-1 and NHS-2). The latter contained the inhibitor, denominated gamma CdcPLI. The molecular mass of gamma CdcPLI, determined by Matrix-Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF), was 22,340 Da. Partial sequences obtained by Edman degradation and by mass spectrometry (MALDI-TOF/TOF), showed similarity, as expected, to other related inhibitors. Circular dichroism (CD) analysis showed the presence of approximately 22% alpha helices and 29% beta sheets in the protein secondary structure. Additionally, CD studies also indicated no significant changes in the secondary structure of gamma CdcPLI when it is complexed to BpPLA(2)-TXI. On the other hand, dynamic light scattering (DLS) assays showed a temperature-dependent oligomerization behavior for this inhibitor. Biochemical analyses showed gamma CdcPLI was able to inhibit the enzymatic, cytotoxic and myotoxic activities of PLA(2)s. Structural and functional studies performed on this inhibitor may elucidate the action mechanisms of PLA(2) inhibitors. In addition, we hope this study may contribute to investigating the potential use of these inhibitors for the treatment of snakebite or inflammatory diseases in which PLA(2)s may be involved. (C) 2014 Elsevier Ltd. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Shedding Lights on Crude Venom from Solitary Foraging Predatory Ant <i>Ectatomma opaciventre</i>: Initial Toxinological Investigation

Some species of primitive predatory ants, despite living in a colony, exercise their hunting collection strategy individually; their venom is painful, paralyzing, digestive, and lethal for their prey, yet the toxins responsible for these effects are poorly known. Ectatomma opaciventre is a previously unrecorded solitary hunting ant from the Brazilian Cerrado. To overcome this hindrance, the present study performed the in vitro enzymatic, biochemical, and biological activities of E. opaciventre to better understand the properties of this venom. Its venom showed several proteins with masses ranging from 1–116 kDa, highlighting the complexity of this venom. Compounds with high enzymatic activity were described, elucidating different enzyme classes present in the venom, with the presence of the first L-amino acid oxidase in Hymenoptera venoms being reported. Its crude venom contributes to a state of blood incoagulability, acting on primary hemostasis, inhibiting collagen-induced platelet aggregation, and operating on the fibrinolysis of loose red clots. Furthermore, the E. opaciventre venom preferentially induced cytotoxic effects on lung cancer cell lines and three different species of Leishmania. These data shed a comprehensive portrait of enzymatic components, biochemical and biological effects in vitro, opening perspectives for bio-pharmacological application of E. opaciventre venom molecules