Neuroinflammatin and Developmental Vulnerability to Manganese Toxicity



 DESCRIPTION (provided by applicant): The Tjalkens lab (Colorado State University) was recently awarded a grant to examine how excessive levels of the essential element manganese (Mn) during juvenile development causes inflammatory activation of glial cells that predisposes dopaminergic neurons to injury later in life. Data from this project indicate that neuro-inflammation may be a critical link between exposure to Mn early in life and heightened susceptibility to neurological dysfunction during aging. The parent grant is exploring these questions using novel transgenic reporter and knockout mice to examine the molecular pathways regulating inflammation in the brain that increase the risk for neurological disease in Mn-exposed individuals. The proposed Virtual Consortium will extend these studies to determine how Mn exposure early in life increases the risk for adverse neurological outcomes following infection with commonly encountered viruses, including Western Equine Encephalitis virus (WEEV), neuro adapted Sindbis virus and H1N1 influenza virus, the current major pandemic flu virus. Clinical and experimental evidence implicates viral infection as a risk factor for neurodegenerative diseases, including Parkinson's disease (PD). Neurotropic (or neuro-affecting) viruses induce many of the pathological features of PD, such as protein aggregation, oxidative stress, autophagy/mitophagy defects, neuro inflammation, and neuronal loss in the substantia nigra (SN). Viral infection may therefore represent an important environmental interaction that increases the risk for neurological disease following exposure to neurotoxic compounds. Excessive exposure to Mn early in life can not only have lasting effects on neurological function but also can enhance neuro inflammation during viral infection. This Virtual Consortium addresses this question by bringing together talented new collaborators in neuro virology (Richard Smeyne, St. Jude) and bioinformatics (Ric Slayden, CSU) to uncover mechanisms underlying the capacity of Mn to enhance neurodegeneration relevant to PD following exposure to commonly encountered viruses. The addition of H1N1 influenza virus, in particular, gives this Consortium a high level of clinical relevance, as does the use of vaccine developed in our laboratory used to mitigate the severity of viral infection in these models. It is our Central Hypothesis that exposure to Mn during juvenile development will enhance susceptibility to the neurological effects of WEEV and H1N1, resulting in progressive loss of dopaminergic neurons in the substantia nigra associated with inflammatory activation of glial cells. This hypothesis will be tested by new Specific Aims that will assess the capacity of Mn to exacerbate the neurological effects of infection by either WEEV/Sindbis (Tjalkens) or H1N1 (Smeyne), with host-pathogen transcriptome responses assessed using Next Generation Sequencing/RNA-Seq (Slayden). Thus, our Consortium is highly responsive to the ViCTER programmatic goals of i) conducting synergistic, trans-disciplinary research, ii) supporting the exchange of knowledge among individuals from diverse disciplines and iii) developing novel approaches for understanding the role of environmental chemicals in the etiology of disease that could impact clinical or public health practice.