Mechanisms of Iron Dependent Gene Expression in Trichomonas Vaginalis

Trichomoniasis is the most common sexually transmitted infection (STI) of non-viral origin in humans caused by the parasitic protozoan Trichomonas vaginalis. About 170 million new cases were reported annually. Iron is an essential element for almost all organisms, participating many processes in the cells. Previous studies indicated that iron is required for critical housekeeping functions, such as proteosynthesis, genome duplication, and energy fixation in T. vaginalis. The parasite can utilize various host iron-containing proteins, such as lactoferrin, hemoglobin, and low-molecular weight-iron complexes. However, these molecules are mostly supplied by menstrual blood. Hence, the protist must possess mechanisms to cope with iron-stress related damages. In our preliminary data, we found that the cells are unable to proliferate under iron-deficient environments; however, they can maintain the survival for at least 66 hours. This observation implies that T. vaginalis is able to survive in iron-starved environments. However, the survival mechanisms are still unknown. In previous studies, the effects of iron on T. vaginalis mainly focus on single proteins, little is known about the global gene expression patterns and the mechanisms underlying the iron-dependent regulation. The present 3 years proposal aimed to elucidate how iron modulates the regulatory networks involved in the survival of T. vaginalis. Moreover, our preliminary data showed that the antioxidants and nitric oxide (NO) are significantly elevated in T. vaginalis, suggesting that the redox-dependent signaling transduction might play a pivotal role in cell survival under iron deficiency. We propose to establish the global mRNA and protein expression profiles of different iron supplements in the culture medium by using high throughput technologies, such as next generation sequencing and LC-MS/MS in order to identify putative iron regulatory networks and the survival required molecules. Coupling mRNA and protein data, the putative iron-responsive element (IRE)-possessing genes will be analyzed. The biological function of these genes/ proteins will be accessed by using siRNA and gene knockout technology. The interacting proteins will be also determined by using co-immunoprecipitation. The aims of this proposal are: (1) To investigate the relationship between NO and cell survival in iron-deficient T. vaginalis. (2) To identify the survival-related genes by using integrated transcriptomic and proteomic analysis. (3) To establish the IRE-possessing genes and iron-dependent regulatory networks. The ultimate goal of this proposal is to use cutting-edge technologies to establish a complete expression atlas of mRNA and cytsolic proteins regulated by iron in T. vaginalis. Present studies on the regulation of the novel iron-dependent networks in T. vaginalis will undoubtedly enhance our understanding on the survival of T. vaginalis under hash microenvironment and potentially used as a basis for the development of new chemotherapeutic agents.

Project ID:PC10601-0109
External Project ID:MOST104-2320-B182-025-MY3