Heme-Induced ROS in Trypanosoma Cruzi Activates CaMKII-Like That Triggers Epimastigote Proliferation. One Helpful Effect of ROS

Heme is a ubiquitous molecule that has a number of physiological roles. The toxic effects of this molecule have been demonstrated in various models, based on both its pro-oxidant nature and through a detergent mechanism. It is estimated that about 10 mM of heme is released during blood digestion in the blood-sucking bug's midgut. The parasite Trypanosoma cruzi, the agent of Chagas' disease, proliferates in the midgut of the insect vector; however, heme metabolism in trypanosomatids remains to be elucidated. Here we provide a mechanistic explanation for the proliferative effects of heme on trypanosomatids. Heme, but not other porphyrins, induced T. cruzi proliferation, and this phenomenon was accompanied by a marked increase in reactive oxygen species (ROS) formation in epimastigotes when monitored by ROS-sensitive fluorescent probes. Heme-induced ROS production was time-and concentration-dependent. In addition, lipid peroxidation and the formation of 4-hydroxy-2-nonenal (4-HNE) adducts with parasite proteins were increased in epimastigotes in the presence of heme. Conversely, the antioxidants urate and GSH reversed the heme-induced ROS. Urate also decreased parasite proliferation. Among several protein kinase inhibitors tested only specific inhibitors of CaMKII, KN93 and Myr-AIP, were able to abolish heme-induced ROS formation in epimastigotes leading to parasite growth impairment. Taken together, these data provide new insight into T. cruzi- insect vector interactions: heme, a molecule from the blood digestion, triggers epimastigote proliferation through a redox-sensitive signalling mechanism

Correction: Recombinant L-Asparaginase from Zymomonas mobilis: A Potential New Antileukemic Agent Produced in Escherichia coli.

[This corrects the article DOI: 10.1371/journal.pone.0156692.]

Too Much Feeling : SE Hinton's The Outsiders (1967), Conflicting Emotions, Identity, and Socialization

This article argues that emotions are utilized for norm breaking, identity formation, and socialization in S.E. Hinton's YA novel The Outsiders (1967). Drawing on the history of emotions studies, it investigates how emotional expressions are utilized to negotiate and contest given emotional norms on the one hand, and Young Adult literary conventions on the other. The point of departure is intersectional and focuses on the relationship between emotion, power, and socialization. In particular, the article considers how intersections of age, gender, and class relate to depictions of feeling and establishing of new emotional norms. The article shows that the feelings that the main character Pony expresses are part of a reiterative process of negotiation of power; they work as instruments for changing emotional norms connected to his age, class, and gender