ABSTRACT
Identification of regulators of Toxoplasma gondii bradyzoite development and cyst formation is the most direct way to address the importance of parasite development in long-term persistence and reactivation of this parasite. Here we show that a T. gondii gene (named Regulator of Cystogenesis 1; ROCY1) is sufficient for T. gondii bradyzoite formation in vitro and in vivo. ROCY1 encodes an RNA binding protein that has a preference for 3' regulatory regions of hundreds of T. gondii transcripts, and its RNA-binding domains are required to mediate bradyzoite development. Female mice infected with ΔROCY1 parasites have reduced (>90%) cyst burden. While viable parasites can be cultivated from brain tissue for up to 6 months post-infection, chronic brain-resident ΔROCY1 parasites have reduced oral infectivity compared to wild type. Despite clear defects in bradyzoite formation and oral infectivity, ΔROCY1 parasites were able to reactivate with similar timing and magnitude as wild type parasites for up to 5 months post-infection. Therefore while ROCY1 is a critical regulator of the bradyzoite developmental pathway, it is not required for parasite reactivation, raising new questions about the persisting life stage responsible for causing recrudescent disease.
Subject(s)
Toxoplasma , Female , Animals , Mice , Toxoplasma/metabolism , Gene Regulatory Networks , Neoplasm Recurrence, Local , Brain/metabolism , Protozoan Proteins/genetics , Protozoan Proteins/metabolismABSTRACT
BACKGROUND/PURPOSE: African American women are diagnosed with breast cancer at later stages and have higher mortality rates than white women. The Patient Voices Network (PVN), a community group whose vision is "a community of educated and involved patients working hand in hand with physicians in making decisions about their own health care," conceived of and implemented a walk to raise awareness of breast cancer and link women to screening resources in a low-income, urban community OBJECTIVES: To describe the planning and implementation of the Concerned About You: Breast Cancer Awareness Walk & Wellness Event and its impact on an academic community partnership. METHODS: A narrative approach was used. Meeting minutes and event planning notes were reviewed. Community participation rates and participant satisfaction were tracked using registration records and a survey administered at the event. RESULTS: 328 community members registered and 194 attended. Responses to a satisfaction survey indicated community buy-in and interest in future events. Two women were screened at the event and 78 were screened at a follow-up opportunity at their primary care practices. The process was driven by participatory guidelines and laid the foundation for future activities. CONCLUSIONS: Community input addressed the need for screening mammography in an underserved community. The partnership approach featured complementary strengths of both patients and University staff, fostered skill building and co-learning, and ultimately strengthened our partnership. A partnered approach may be effective in engaging hard-to-reach populations to address health disparities.
Subject(s)
Black or African American , Breast Neoplasms , Early Detection of Cancer , Health Promotion/methods , Adolescent , Adult , Aged , Breast Neoplasms/ethnology , Female , Humans , Medically Underserved Area , Middle Aged , New York , Urban Population , Young AdultABSTRACT
Acute exacerbations of pulmonary fibrosis are characterized by rapid decrements in lung function. Environmental factors that may contribute to acute exacerbations remain poorly understood. We have previously demonstrated that exposure to inhaled lipopolysaccharide (LPS) induces expression of genes associated with fibrosis. To address whether exposure to LPS could exacerbate fibrosis, we exposed male C57BL/6 mice to crystalline silica, or vehicle, followed 28 days later by LPS or saline inhalation. We observed that mice receiving both silica and LPS had significantly more total inflammatory cells, more whole lung lavage MCP-1, MIP-2, KC and IL-1ß, more evidence of oxidative stress and more total lung hydroxyproline than mice receiving either LPS alone, or silica alone. Blocking oxidative stress with N-acetylcysteine attenuated whole lung inflammation but had no effect on total lung hydroxyproline. These observations suggest that exposure to innate immune stimuli, such as LPS in the environment, may exacerbate stable pulmonary fibrosis via mechanisms that are independent of inflammation and oxidative stress.
Subject(s)
Immunity, Innate/drug effects , Lipopolysaccharides/administration & dosage , Lipopolysaccharides/pharmacology , Oxidative Stress/drug effects , Pulmonary Fibrosis/immunology , Pulmonary Fibrosis/pathology , Acetylcysteine/pharmacology , Administration, Inhalation , Animals , Bronchoalveolar Lavage , Cytokines/metabolism , Drinking Water , Hydroxyproline/metabolism , Inflammation/pathology , Lung/immunology , Lung/metabolism , Lung/pathology , Male , Mice , Mice, Inbred C57BL , Protein Carbonylation/drug effects , Pulmonary Fibrosis/chemically induced , Silicon DioxideABSTRACT
Accumulating evidence suggests that gender can have a profound effect on incidence and severity of a variety of pulmonary diseases. To address the influence of gender on the development of silica-induced pulmonary fibrosis, we instilled 0.2 g/kg silica into male and female C57BL/6 mice and examined the fibrotic and inflammatory response at 14 days postexposure. Both silica-exposed male and female mice had significant increases in total lung hydroxyproline compared with saline controls. However, silica-exposed female mice had significantly less total lung hydroxyproline than silica-exposed male mice. This observation was confirmed by color thresholding image analysis. Interestingly, silica-exposed female mice had significantly more inflammatory cells, the majority of which were macrophages, as well as higher levels of the macrophage-specific chemokines MCP-1 and CCL9 in whole lung lavage compared with silica-exposed male mice. We also show that at baseline, estrogen receptor α (ERα) mRNA expression is lower in female mice than in males and that ERα mRNA expression is decreased by silica exposure. Finally, we show that the response of ovariectomized female mice to silica instillation is similar to that of male mice. These observations together show that gender influences the lung response to silica.