Cytometric blood phenotyping in free-living white-eyed parakeet (Psittacara leucophthalmus) / Fenotipagem citométrica do sangue de maritacas jovens de vida-livre (Psittacara leucophthalmus)

This study aimed at performing cytometric phenotyping of the blood samples from free-living, young white-eyed parakeets (Psittacara leucophthalmus), stained with 3,3-dihexyloxacarbocyanine [DiOC6(3)]. DiOC6(3)-stained whole blood samples from 19 free-living, young white-eyed parakeets were analyzed by flow cytometry and cell types were distinguished by their typical fluorescence in blue laser channel (FL-1) and SSC (side scatter). It was possible to differentiate erythrocytes (58.3±13.6) from leukocytes (32.4±13.1) and some of the leucocyte subpopulations: lymphocytes/thrombocytes (29.7±7.7), monocytes (30.6±8.5), and granulocytes (5.9-26). However, lymphocytes and thrombocytes could not be sorted in the plots. Our study determined that the predominant population in white-eyed parakeet (P. leucophthalmus) was lymphocytes, thrombocytes, and monocytes in the leucocytes gates in comparison to the granulocyte population. The cytometry method and use of DiOC6(3) stain was available for parakeets blood samples and can be studied and applied to other species of parrots.(AU)

Este estudo teve como objetivo realizar a fenotipagem citométrica com 3,3-di-hexiloxacarbocianina [DiOC6 (3)] de amostras de sangue de maritacas jovens de vida-livre (Psittacara leucophthalmus). As amostras de sangue total, coradas com DiOC6(3) de 19 maritacas de vida livre, foram analisadas por citometria de fluxo e os tipos de células foram distinguidos por sua fluorescência típica no canal laser azul (FL-1) e SSC (dispersão lateral). Foi possível diferenciar eritrócitos (58,3±13,6) de leucócitos (32,4±13,1) e algumas subpopulações de leucócitos: linfócitos/trombócitos (29,7±7,7), monócitos (30,6±8,5) e granulócitos (5,9-26), entretanto, linfócitos e trombócitos não puderam ser diferenciados em duas populações distintas. Nosso estudo determinou que a população predominante P. leucophthalmus foi mononuclear agranulocítica em comparação com a taxa de aquisição da população granulocítica. A metodologia de citometria de fluxo com uso da coloração de DiOC6(3) foi aplicável a amostras sanguíneas das maritacas e pode ser estudado e aplicado para outras espécies de psitacídeos.(AU)

Cytometric blood phenotyping in free-living white-eyed parakeet (Psittacara leucophthalmus)

ABSTRACT: This study aimed at performing cytometric phenotyping of the blood samples from free-living, young white-eyed parakeets (Psittacara leucophthalmus), stained with 3,3-dihexyloxacarbocyanine [DiOC6(3)]. DiOC6(3)-stained whole blood samples from 19 free-living, young white-eyed parakeets were analyzed by flow cytometry and cell types were distinguished by their typical fluorescence in blue laser channel (FL-1) and SSC (side scatter). It was possible to differentiate erythrocytes (58.3±13.6) from leukocytes (32.4±13.1) and some of the leucocyte subpopulations: lymphocytes/thrombocytes (29.7±7.7), monocytes (30.6±8.5), and granulocytes (5.9-26). However, lymphocytes and thrombocytes could not be sorted in the plots. Our study determined that the predominant population in white-eyed parakeet (P. leucophthalmus) was lymphocytes, thrombocytes, and monocytes in the leucocytes gates in comparison to the granulocyte population. The cytometry method and use of DiOC6(3) stain was available for parakeets blood samples and can be studied and applied to other species of parrots.

RESUMO: Este estudo teve como objetivo realizar a fenotipagem citométrica com 3,3-di-hexiloxacarbocianina [DiOC6 (3)] de amostras de sangue de maritacas jovens de vida-livre (Psittacara leucophthalmus). As amostras de sangue total, coradas com DiOC6(3) de 19 maritacas de vida livre, foram analisadas por citometria de fluxo e os tipos de células foram distinguidos por sua fluorescência típica no canal laser azul (FL-1) e SSC (dispersão lateral). Foi possível diferenciar eritrócitos (58,3±13,6) de leucócitos (32,4±13,1) e algumas subpopulações de leucócitos: linfócitos/trombócitos (29,7±7,7), monócitos (30,6±8,5) e granulócitos (5,9-26), entretanto, linfócitos e trombócitos não puderam ser diferenciados em duas populações distintas. Nosso estudo determinou que a população predominante P. leucophthalmus foi mononuclear agranulocítica em comparação com a taxa de aquisição da população granulocítica. A metodologia de citometria de fluxo com uso da coloração de DiOC6(3) foi aplicável a amostras sanguíneas das maritacas e pode ser estudado e aplicado para outras espécies de psitacídeos.

Cytometric blood phenotyping in free-living white-eyed parakeet (Psittacara leucophthalmus) / Fenotipagem citométrica do sangue de maritacas jovens de vida-livre (Psittacara leucophthalmus)

This study aimed at performing cytometric phenotyping of the blood samples from free-living, young white-eyed parakeets (Psittacara leucophthalmus), stained with 3,3-dihexyloxacarbocyanine [DiOC6(3)]. DiOC6(3)-stained whole blood samples from 19 free-living, young white-eyed parakeets were analyzed by flow cytometry and cell types were distinguished by their typical fluorescence in blue laser channel (FL-1) and SSC (side scatter). It was possible to differentiate erythrocytes (58.3±13.6) from leukocytes (32.4±13.1) and some of the leucocyte subpopulations: lymphocytes/thrombocytes (29.7±7.7), monocytes (30.6±8.5), and granulocytes (5.9-26). However, lymphocytes and thrombocytes could not be sorted in the plots. Our study determined that the predominant population in white-eyed parakeet (P. leucophthalmus) was lymphocytes, thrombocytes, and monocytes in the leucocytes gates in comparison to the granulocyte population. The cytometry method and use of DiOC6(3) stain was available for parakeets blood samples and can be studied and applied to other species of parrots.(AU)

Este estudo teve como objetivo realizar a fenotipagem citométrica com 3,3-di-hexiloxacarbocianina [DiOC6 (3)] de amostras de sangue de maritacas jovens de vida-livre (Psittacara leucophthalmus). As amostras de sangue total, coradas com DiOC6(3) de 19 maritacas de vida livre, foram analisadas por citometria de fluxo e os tipos de células foram distinguidos por sua fluorescência típica no canal laser azul (FL-1) e SSC (dispersão lateral). Foi possível diferenciar eritrócitos (58,3±13,6) de leucócitos (32,4±13,1) e algumas subpopulações de leucócitos: linfócitos/trombócitos (29,7±7,7), monócitos (30,6±8,5) e granulócitos (5,9-26), entretanto, linfócitos e trombócitos não puderam ser diferenciados em duas populações distintas. Nosso estudo determinou que a população predominante P. leucophthalmus foi mononuclear agranulocítica em comparação com a taxa de aquisição da população granulocítica. A metodologia de citometria de fluxo com uso da coloração de DiOC6(3) foi aplicável a amostras sanguíneas das maritacas e pode ser estudado e aplicado para outras espécies de psitacídeos.(AU)

Lysosomal and mitochondrial permeabilization mediates zinc(II) cationic phthalocyanine phototoxicity.

In order to find a novel photosensitizer to be used in photodynamic therapy for cancer treatment, we have previously showed that the cationic zinc(II) phthalocyanine named Pc13, the sulfur-linked dye 2,9(10),16(17),23(24)-tetrakis[(2-trimethylammonium) ethylsulfanyl]phthalocyaninatozinc(II) tetraiodide, exerts a selective phototoxic effect on human nasopharynx KB carcinoma cells and induces an apoptotic response characterized by an increase in the activity of caspase-3. Since the activation of an apoptotic pathway by chemotherapeutic agents contributes to the elimination of malignant cells, in this study we investigated the molecular mechanisms underlying the antitumor action of Pc13. We found that after light exposure, Pc13 induced the production of reactive oxygen species (ROS), which are mediating the resultant cytotoxic action on KB cells. ROS led to an early permeabilization of lysosomal membranes as demonstrated by the reduction of lysosome fluorescence with acridine orange and the release of lysosomal proteases to cytosol. Treatment with antioxidants inhibited ROS generation, preserved the integrity of lysosomal membrane and increased cell proliferation in a concentration-dependent manner. Lysosome disruption was followed by mitochondrial depolarization, cytosolic release of cytochrome C and caspases activation. Although no change in the total amount of Bax was observed, the translocation of Bax from cytosol to mitochondria, the cleavage of the pro-apoptotic protein Bid, together with the decrease of the anti-apoptotic proteins Bcl-XL and Bcl-2 indicated the involvement of Bcl-2 family proteins in the induction of the mitochondrial pathway. It was also demonstrated that cathepsin D, but not caspase-8, contributed to Bid cleavage. In conclusion, Pc13-induced cell photodamage is triggered by ROS generation and activation of the mitochondrial apoptotic pathway through the release of lysosomal proteases. In addition, our results also indicated that Pc13 induced a caspase-dependent apoptotic response, being activation of caspase-8, -9 and -3 the result of a post-mitochondrial event.