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Mumps virus (MuV) caused the most viral meningitis before mass immunization. Unfortunately, MuV has reemerged in the United States in the past several years. MuV is a member of the genus Rubulavirus, in the family Paramyxoviridae, and has a nonsegmented negative-strand RNA genome. The viral RNA-dependent RNA polymerase (vRdRp) of MuV consists of the large protein (L) and the phosphoprotein (P), while the nucleocapsid protein (NP) encapsulates the viral RNA genome. These proteins make up the replication and transcription machinery of MuV. The P protein is phosphorylated by host kinases, and its phosphorylation is important for its function. In this study, we performed a large-scale small interfering RNA (siRNA) screen targeting host kinases that regulated MuV replication. The human kinase ribosomal protein S6 kinase beta-1 (RPS6KB1) was shown to play a role in MuV replication and transcription. We have validated the role of RPS6KB1 in regulating MuV using siRNA knockdown, an inhibitor, and RPS6KB1 knockout cells. We found that MuV grows better in cells lacking RPS6KB1, indicating that it downregulates viral growth. Furthermore, we detected an interaction between the MuV P protein and RPS6KB1, suggesting that RPS6KB1 directly regulates MuV replication and transcription. IMPORTANCE Mumps virus is an important human pathogen. In recent years, MuV has reemerged in the United State, with outbreaks occurring in young adults who have been vaccinated. Our work provides insight into a previously unknown mumps virus-host interaction. RPS6KB1 negatively regulates MuV replication, likely through its interaction with the P protein. Understanding virus-host interactions can lead to novel antiviral drugs and enhanced vaccine production. [ABSTRACT FROM AUTHOR]

Conjugated equine estrogens (CEE) is the most widely prescribed pharmaceutical estrogen replacement therapy (ERT) for postmenopausal women in the United States and is the ERT of the Women’s Health Initiative. Previous studies from our laboratory have demonstrated that CEE exerts neurotrophic and neuroprotective effects in neurons involved in learning and memory, and which are affected in Alzheimer’s disease. The present work demonstrates that CEE potentiated the rise in intracellular calcium ([Ca2+]i) following exposure to physiological concentrations of glutamate. In contrast, the reverse effect occurred in the presence of excitotoxic levels of glutamate exposure, where CEE attenuated the rise in [Ca2+]i. Potentiation of the glutamate response was mediated by the NMDA receptor, as the NMDA receptor antagonist MK-801 blocked the CEE-induced potentiation, whereas the L-type calcium channel blocker nifedipine did not. Further, the CEE-potentiated glutamate response was mediated by a src tyrosine kinase, as the tyrosine kinase inhibitor PP2 blocked the potentiation induced by CEE and neurons treated with CEE displayed increased phosphorylated tyrosine. The inhibition by CEE of [Ca2+]i rise in the presence of excitotoxic levels of glutamate was mediated by mitogen activated protein kinase (MAPK), as the protective effect of CEE was blocked by inhibiting MAPK activation with PD98059. These data provide potential mechanisms to explain the cognitive enhancing and neuroprotective effects exerted by ERT. [Copyright &y& Elsevier]

Traumatic brain injury (TBI) is a significant cause of morbidity and mortality in the USA and other developed countries worldwide. Following the initial mechanical insult, the brain's primary innate immune effector, microglia, initiate inflammatory signaling cascades and pathophysiological responses that can lead to chronic neuroinflammation and neurodegenerative sequelae. The p38α MAPK signaling pathway in microglia is a key contributor to inflammatory responses to diverse disease-relevant stressors and injury conditions. Therefore, we tested here whether microglia p38α contributes to acute and persistent inflammatory responses induced by a focal TBI. We generated conditional cell-specific knockout of p38α in microglia using a CX3CR1 Cre-lox system, subjected the p38α knockout and wild-type mice to a controlled cortical impact TBI, and measured inflammatory responses at acute (1-day) and subacute (7-day) post-injury time points. We found that deletion of p38α in microglia only was sufficient to attenuate multiple pro-inflammatory responses following TBI, notably reducing pro-inflammatory cytokine/chemokine production and recruitment of inflammatory monocytes into the brain and preventing the persistent microglial morphological activation. These data provide strong evidence supporting a role for microglial p38α in propagation of a chronic and potentially neurotoxic pro-inflammatory environment in the brain following TBI. [ABSTRACT FROM AUTHOR]

Currently, there is a paucity of information regarding the molecular pathogenesis for many high-consequence pathogens (HCPs) that pose threats to both national and international public health. In spite of this, investigations of the molecular pathogenesis for many HCPs have been limited to gross pathological changes in animal models or global analysis of gene expression. Further, questions remain regarding the ability of animal models of disease to recapitulate human molecular pathogenesis or act as predictors of therapeutic efficacy. Thus, it is likely that medical countermeasure development for HCPs will rely on identifying therapeutic targets that are uniquely modulated during HCP infection. It is also appreciated that many cellular processes can be regulated independently of changes in transcription or translation through phosphorylation events. Cellular kinases, individually or collectively (the kinome), play critical roles in regulating complex biology, underlie various malignancies, and represent high-priority drug targets. The growing interest in kinases in both basic and translational research has driven efforts to develop technologies that enable characterization of phosphorylation-mediated signal transduction. To this end, enhanced technical capabilities at the IRF-Frederick provide the unique capability for characterizing host responses to HCP insult during the course of infection and identify novel targets for therapeutic intervention., (Published 2014. This article is a US Government work and is in the public domain in the USA.)