Cellular stress and redox activity proteins are involved in gastric carcinogenesis associated with Helicobacter pylori infection expressing high levels of thioredoxin-1 / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Helicobacter pylori infection is related to the development of gastric diseases. Our previous studies showed that high thioredoxin-1 (Trx1) expression in H. pylori can promote gastric carcinogenesis. To explore the underlying molecular mechanisms, we performed an isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic analysis of stomach tissues from Mongolian gerbil infected with H. pylori expressing high and low Trx1. Differences in the profiles of the expressed proteins were analyzed by bioinformatics and verified using Western blot analysis. We found three candidate proteins, 14-3-3α/β, glutathione-S-transferase (GST), and heat shock protein 70 (HSP70), in high Trx1 tissues compared with low Trx1 tissues and concluded that cellular stress and redox activity-related proteins were involved in the pathogenesis of gastric cancer associated with H. pylori Trx1.

HSP70 of Leishmania amazonensis alters resistance to different stresses and mitochondrial bioenergetics

The 70 kDa heat shock protein (HSP70) is a molecular chaperone that assists the parasite Leishmania in returning to homeostasis after being subjected to different types of stress during its life cycle. In the present study, we evaluated the effects of HSP70 transfection of L. amazonensis promastigotes (pTEX-HSP70) in terms of morphology, resistance, infectivity and mitochondrial bioenergetics. The pTEX-HSP70 promastigotes showed no ultrastructural morphological changes compared to control parasites. Interestingly, the pTEX-HSP70 promastigotes are resistant to heat shock, H2O2-induced oxidative stress and hyperbaric environments. Regarding the bioenergetics parameters, the pTEX-HSP70 parasites had higher respiratory rates and released less H2O2 than the control parasites. Nevertheless, the infectivity capacity of the parasites did not change, as verified by the infection of murine peritoneal macrophages and human macrophages, as well as the infection of BALB/c mice. Together, these results indicate that the overexpression of HSP70 protects L. amazonensis from stress, but does not interfere with its infective capacity.

Effect of the Absence of Heat Shock Protein 70.1 (hsp70.1) on Retinal Photic Injury

This study aimed to evaluate the protective effect of heat shock protein70 (hsp70) on retinal photic injuries, and to determine the relationship between hsp70s from hsp70.1 and 70.3. C57BL/6 wild type (hsp70.1+/+) and knockout type (hsp70.1-/-) mice from the same littermates were placed in light of 11000 lux for 6 hours, and were sacrificed at 1, 4, 7, and 14 days after stress. H & E staining, immunohistochemistry, and western blot analysis were performed. The hsp70.1-/- mice exhibited more disarranged and more diffusely destroyed photoreceptors than the hsp70.1+/+ mice. Hsp70 induction by light in both the hsp70.1 +/+ and hsp70.1 -/- mice peaked at 1 day after light stress. The Hsp70 level in the hsp70.1 +/+ mice reduced slowly and was almost constant for 7 days. However, in the hsp70.1 -/- mice, it decreased rapidly and returned, after 7 days, to a similar level to that prior to light exposure. According to which gene they originate from, hsp70s may play specific roles in protecting the retina against stresses. Hsp70 from the hsp70.1 gene may act as a sustained responder to retinal photic injury.