Project description:Complement protein C1q is induced after injury in the brain and during Alzheimer's disease and has been shown to protect against amyloid-beta induced neuronal death. In this study, we used microarray approach to identify the pathways modulated by C1q that are associated with neuroprotection.
Project description:Complement protein C1q is induced after injury in the brain and during Alzheimer's disease and has been shown to protect against amyloid-beta induced neuronal death. In this study, we used microarray approach to identify the pathways modulated by C1q that are associated with neuroprotection. Immature rat cortical primary neurons are treated with fibrillar amyloid-beta peptides and/or C1q for 3h before RNA extraction and hybridization on rat Affymetrix microarrays. Supplementary file: Processed/normalized, probe-level signal intensities from neurons treated with amyloid-beta or C1q. Median signal intensity used as global normalization method, done with JMP genomics (v5.0) software.
Project description:Identification of transcriptional profiles stimulated by the complement protein C1q in rat immature neurons associated with the C1q-dependent neuroprotection observed in vitro. Use of the unbiased whole genome microarray approach to identify genes regulated by C1q. Immature neurons grown in vitro for 3 days were stimulated with 10 nM C1q for 3h.
Project description:Identification of transcriptional profiles stimulated by the complement protein C1q in rat immature neurons associated with the C1q-dependent neuroprotection observed in vitro. Use of the unbiased whole genome microarray approach to identify genes regulated by C1q.
Project description:Neuroimmune interactions mediate intercellular communication and underlie critical brain functions. Microglia, CNS-resident macrophages, modulate the brain through direct physical interactions and the secretion of molecules. One such secreted factor, the complement protein C1q, contributes to complement-mediated synapse elimination in development and disease models, yet brain C1q protein levels increase significantly throughout aging. How age-related C1q affects neuronal function has not been demonstrated. Here we report that C1q interacts with neuronal ribonucleoprotein (RNP) complexes in an age-dependent manner. Purified C1q protein undergoes RNA-dependent liquid-liquid phase separation (LLPS) in vitro, and the interaction of C1q with neuronal RNP complexes in vivo is dependent on RNA and endocytosis. Mice lacking C1q have age-specific alterations in neuronal protein synthesis in vivo and impaired fear memory extinction. Together, our findings reveal a biophysical property of C1q that underlies RNA- and age-dependent neuronal interactions and demonstrate a unique role of C1q in critical intracellular neuronal processes.
Project description:Neuroimmune interactions mediate intercellular communication and underlie critical brain functions. Microglia, CNS-resident macrophages, modulate the brain through direct physical interactions and the secretion of molecules. One such secreted factor, the complement protein C1q, contributes to complement-mediated synapse elimination in development and disease models, yet brain C1q protein levels increase significantly throughout aging. Here we report that C1q interacts with neuronal ribonucleoprotein (RNP) complexes in an age-dependent manner. Purified C1q protein undergoes RNA-dependent liquid-liquid phase separation (LLPS) in vitro, and the interaction of C1q with neuronal RNP complexes in vivo is dependent on RNA and endocytosis. Mice lacking C1q have age-specific alterations in neuronal protein synthesis in vivo and impaired fear memory extinction. Together, our findings reveal a biophysical property of C1q that underlies RNA- and age-dependent neuronal interactions and demonstrate a role of C1q in critical intracellular neuronal processes.
Project description:Few studies have assessed the patterns of parasite populations of rodents over a longitudinal gradient in Chile. In this work, the gastrointestinal helminthic fauna of invasive rodents in Chile was examined to assess the association between their presence/absence and abundance with latitude, host sex, and host body condition, and to assess the coexistence and correlation of the abundance between parasite species. Rodents were obtained from 20 localities between 33 and 43°S. Helminths were extracted from the gastrointestinal tract and identified morphologically. Overall, 13 helminth taxa were obtained. The most frequently identified parasite species was Heterakis spumosa, and the most abundant was Syphacia muris, while Physaloptera sp. was the most widely distributed. No locality presented with a coexistence that was different from that expected by chance, while the abundance of five helminthic species correlated with the abundance of another in at least one locality, most likely due to co-infection rather than interaction. Host sex was associated with parasite presence or abundance, and female sex-biased parasitism was notably observed in all cases. Body condition and latitude presented either a positive or negative association with the presence or abundance of parasites depending on the species. It is notable that the likely native Physaloptera sp. is widely distributed among invasive rodents. Further, gravid females were found, suggesting spillback of this species to the native fauna. The low frequency and abundance of highly zoonotic hymenolepid species suggest that rodents are of low concern regarding gastrointestinal zoonotic helminths.