Examinando por Autor "Perez, C"

Mostrando 1 - 2 de 2
  • Miniatura
    Ítem
    ATP Induces IL-1𝛽 Secretion in Neisseria gonorrhoeae-Infected Human Macrophages by a Mechanism Not Related to the NLRP3/ASC/Caspase-1 Axis
    (HINDAWI PUBLISHING, 2016) Garcia, K; Escobar, G; Mendoza, P; Beltran, C; Perez, C; Arancibia, S; Vernal, R; Rodas, PI; Acuna-Castillo, C; Escobar, A
    Neisseria gonorrhoeae (Ngo) has developed multiple immune evasion mechanisms involving the innate and adaptive immune responses. Recent findings have reported that Ngo reduces the IL-1 beta secretion of infected human monocyte-derived macrophages (MDM). Here, we investigate the role of adenosine triphosphate (ATP) in production and release of IL-1 beta in Ngo-infected MDM. We found that the exposure of Ngo-infected MDM to ATP increases IL-1 beta levels about ten times compared with unexposed Ngo-infected MDM (P < 0.01). However, we did not observe any changes in inflammasome transcriptional activation of speck-like protein containing a caspase recruitment domain (CARD) (ASC, P > 0.05) and caspase-1 (CASP1, P > 0.05). In addition, ATP was not able to modify caspase-1 activity in Ngo-infected MDM but was able to increase pyroptosis (P > 0.01). Notably ATP treatment defined an increase of positive staining for IL-1 beta with a distinctive intracellular pattern of distribution. Collectively, these data demonstrate that ATP induces IL-1 beta secretion by a mechanism not related to the NLRP3/ASC/caspase-1 axis and likely is acting at the level of vesicle trafficking or pore formation.
  • Miniatura
    Ítem
    MECHANISTIC STUDY OF A RUTHENIUM HYDRIDE COMPLEX OF TYPE [RuH(CO)(N-N)(PR3)2]+ AS CATALYST PRECURSOR FOR THE HYDROFORMYLATION REACTION OF 1-HEXENE
    (Sociedad Chilena de Química, 2016-12) Moya, SA; Yanez, M; Perez, C; Lopez, R; Zuniga, C; Cardenas-Jiron, G
    The catalytic activity of systems of type [RuH(CO)(N-N)(PR3)(2)](+) was evaluated in the hydroformylation reaction of 1-hexene. The observed activity is explained through a reaction mechanism on the basis of the quantum theory. The mechanism included total energy calculations for each of the intermediaries of the elemental steps considered in the catalytic cycle. The deactivation of the catalyst precursors takes place via dissociation of the polypyridine ligand and the subsequent formation of thermodynamically stable species, such as RuH(CO)(3)(PPh3)(2) and RuH3(CO)(PPh3)(2), which interrupt the catalytic cycle. In addition, the theoretical study allows to explain the observed regioselectivity which is defined in two steps: (a) the hydride migration reaction with an anti-Markovnikov orientation to produce the alkyl-linear-complex (3.1a), which is more stable by 19.4 kJ/mol than the Markovnikov orientation (alkyl-branched-complex) (3.1b); (b) the carbon monoxide insertion step generates the carbonyl alkyl-linear specie (4.1a) which is more stable by 9.5 kJ/mol than the alternative species (4.1b), determining the preferred formation of heptanal in the hydroformylation of 1-hexene. Palabras clave