Comparative Analysis of the Secretome and Interactome of Trypanosoma cruzi and Trypanosoma rangeli Reveals Species Specific Immune Response Modulating Proteins
FRONTIERS IN IMMUNOLOGY
Authors: Watanabe Costa, Renata; Batista, Marina Ferreira; Meneghelli, Isabela; Vidal, Ramon Oliveira; Najera, Carlos Alcides; Mendes, Ana Clara; Andrade-Lima, Izabela Augusta; da Silveira, Jose Franco; Lopes, Luciano Rodrigo; Ferreira, Ludmila Rodrigues Pinto; Antoneli, Fernando; Bahia, Diana
Abstract
Chagas disease, a zoonosis caused by the flagellate protozoanTrypanosoma cruzi, is a chronic and systemic parasitic infection that affects similar to 5-7 million people worldwide, mainly in Latin America. Chagas disease is an emerging public health problem due to the lack of vaccines and effective treatments. According to recent studies, severalT. cruzisecreted proteins interact with the human host during cell invasion. Moreover, some comparative studies withT. rangeli, which is non-pathogenic in humans, have been performed to identify proteins directly involved in the pathogenesis of the disease. In this study, we present an integrated analysis of canonical putative secreted proteins (PSPs) from both species. Additionally, we propose an interactome with human host and gene family clusters, and a phylogenetic inference of a selected protein. In total, we identified 322 exclusively PSPs inT. cruziand 202 inT. rangeli. Among the PSPs identified inT. cruzi, we found several trans-sialidases, mucins, MASPs, proteins with phospholipase 2 domains (PLA2-like), and proteins with Hsp70 domains (Hsp70-like) which have been previously characterized and demonstrated to be related toT. cruzivirulence. PSPs found inT. rangeliwere related to protozoan metabolism, specifically carboxylases and phosphatases. Furthermore, we also identified PSPs that may interact with the human immune system, including heat shock and MASP proteins, but in a lower number compared toT. cruzi. Interestingly, we describe a hypothetical hybrid interactome of PSPs which reveals thatT. cruzisecreted molecules may be down-regulating IL-17 whilstT. rangelimay enhance the production of IL-15. These results will pave the way for a better understanding of the pathophysiology of Chagas disease and may ultimately lead to the identification of molecular targets, such as key PSPs, that could be used to minimize the health outcomes of Chagas disease by modulating the immune response triggered byT. cruziinfection.
Hsp70/Bmi1-FoxO1-SOD Signaling Pathway Contributes to the Protective Effect of Sound Conditioning against Acute Acoustic Trauma in a Rat Model
NEURAL PLASTICITY
Authors: Zhu, Guoxia; Wu, Yongxiang; Qiu, Yang; Tian, Keyong; Mi, Wenjuan; Liu, Xinqin; Chen, Yuanyuan; Jia, Jinwen; Luo, Jiasheng; Lu, Lianjun; Qiu, Jianhua
Abstract
Sound conditioning (SC) is defined as "toughening" to lower levels of sound over time, which reduces a subsequent noise-induced threshold shift. Although the protective effect of SC in mammals is generally understood, the exact mechanisms involved have not yet been elucidated. To confirm the protective effect of SC against noise exposure (NE) and the stress-related signaling pathway of its rescue, we observed target molecule changes caused by SC of low frequency prior to NE as well as histology analysis in vivo and verified the suggested mechanisms in SGNs in vitro. Further, we investigated the potential role of Hsp70 and Bmi1 in SC by targeting SOD1 and SOD2 which are regulated by the FoxO1 signaling pathway based on mitochondrial function and reactive oxygen species (ROS) levels. Finally, we sought to identify the possible molecular mechanisms associated with the beneficial effects of SC against noise-induced trauma. Data from the rat model were evaluated by western blot, immunofluorescence, and RT-PCR. The results revealed that SC upregulated Hsp70, Bmi1, FoxO1, SOD1, and SOD2 expression in spiral ganglion neurons (SGNs). Moreover, the auditory brainstem responses (ABRs) and electron microscopy revealed that SC could protect against acute acoustic trauma (AAT) based on a significant reduction of hearing impairment and visible reduction in outer hair cell loss as well as ultrastructural changes in OHCs and SGNs. Collectively, these results suggested that the contribution of Bmi1 toward decreased sensitivity to noise-induced trauma following SC was triggered by Hsp70 induction and associated with enhancement of the antioxidant system and decreased mitochondrial superoxide accumulation. This contribution of Bmi1 was achieved by direct targeting of SOD1 and SOD2, which was regulated by FoxO1. Therefore, the Hsp70/Bmi1-FoxO1-SOD signaling pathway might contribute to the protective effect of SC against AAT in a rat model.