KCC2 is a neuron-specific K(+)-Cl(-) co-transporter that maintains a low intracellular Cl(-) concentration that is essential for hyperpolarizing inhibition mediated by GABA(A) receptors. Deficits in ...KCC2 activity occur in disease states associated with pathophysiological glutamate release. However, the mechanisms by which elevated glutamate alters KCC2 function are unknown. The phosphorylation of KCC2 residue Ser940 is known to regulate its surface activity. We found that NMDA receptor activity and Ca(2+) influx caused the dephosphorylation of Ser940 in dissociated rat neurons, leading to a loss of KCC2 function that lasted longer than 20 min. Protein phosphatase 1 mediated the dephosphorylation events of Ser940 that coincided with a deficit in hyperpolarizing GABAergic inhibition resulting from the loss of KCC2 activity. Blocking dephosphorylation of Ser940 reduced the glutamate-induced downregulation of KCC2 and substantially improved the maintenance of hyperpolarizing GABAergic inhibition. Reducing the downregulation of KCC2 therefore has therapeutic potential in the treatment of neurological disorders.
The evolution of atmospheric organic carbon as it undergoes oxidation has a controlling influence on concentrations of key atmospheric species, including particulate matter, ozone and oxidants. ...However, full characterization of organic carbon over hours to days of atmospheric processing has been stymied by its extreme chemical complexity. Here we study the multigenerational oxidation of α-pinene in the laboratory, characterizing products with several state-of-the-art analytical techniques. Although quantification of some early generation products remains elusive, full carbon closure is achieved (within measurement uncertainty) by the end of the experiments. These results provide new insights into the effects of oxidation on organic carbon properties (volatility, oxidation state and reactivity) and the atmospheric lifecycle of organic carbon. Following an initial period characterized by functionalization reactions and particle growth, fragmentation reactions dominate, forming smaller species. After approximately one day of atmospheric aging, most carbon is sequestered in two long-lived reservoirs-volatile oxidized gases and low-volatility particulate matter.
The present study investigated the impact of manipulating reading strategies (i.e., reading the questions first QF or reading the passage first PF) during a reading comprehension test where we ...explored how reading strategy was related to student characteristics (i.e., reading achievement and working memory capacity). Participants' eye movements were monitored as they read 12 passages and answered multiple-choice questions. We examined differences in (a) response accuracy, (b) average total time on words in the text, (c) total task reading time, and (d) time reading text relevant to questions as a function of PF and QF strategies. Analyses were conducted to examine whether findings varied as a function of student characteristics (i.e., reading achievement and working memory capacity) and grade level (Grades 3, 5, and 8). Several interesting findings emerged from our study, including a limited effect of reading strategy use on response accuracy, with only eighth graders demonstrating better accuracy in the QF condition, and several demonstrations of PF leading to more efficient test-taking processes, including (a) longer average total reading times on words in the passage in the PF condition that could be associated with creating a better mental model of the text, (b) often being associated with less total-task time, and (c) being associated with more successful search strategies. Implications for providing teachers and students with strategies are discussed.
The potassium chloride cotransporter KCC2 plays a major role in the maintenance of transmembrane chloride potential in mature neurons; thus KCC2 activity is critical for hyperpolarizing membrane ...currents generated upon the activation of γ-aminobutyric acid type A and glycine (Gly) receptors that underlie fast synaptic inhibition in the adult central nervous system. However, to date an understanding of the cellular mechanism that neurons use to modulate the functional expression of KCC2 remains rudimentary. Using Escherichia coli expression coupled with in vitro kinase assays, we first established that protein kinase C (PKC) can directly phosphorylate serine 940 (Ser940) within the C-terminal cytoplasmic domain of KCC2. We further demonstrated that Ser940 is the major site for PKC-dependent phosphorylation for full-length KCC2 molecules when expressed in HEK-293 cells. Phosphorylation of Ser940 increased the cell surface stability of KCC2 in this system by decreasing its rate of internalization from the plasma membrane. Coincident phosphorylation of Ser940 increased the rate of ion transport by KCC2. It was further evident that phosphorylation of endogenous KCC2 in cultured hippocampal neurons is regulated by PKC-dependent activity. Moreover, in keeping with our recombinant studies, enhancing PKC-dependent phosphorylation increased the targeting of KCC2 to the neuronal cell surface. Our studies thus suggest that PKC-dependent phosphorylation of KCC2 may play a central role in modulating both the functional expression of this critical transporter in the brain and the strength of synaptic inhibition.
Animal models of atherosclerosis are used extensively to interrogate molecular mechanisms in serial fashion. We tested whether a novel systems biology approach to integration of preclinical data ...identifies novel pathways and regulators in human disease. Approach and Results: Of 716 articles published in
from 1995 to 2019 using the apolipoprotein E knockout mouse to study atherosclerosis, data were extracted from 360 unique studies in which a gene was experimentally perturbed to impact plaque size or composition and analyzed using Ingenuity Pathway Analysis software. TREM1 (triggering receptor expressed on myeloid cells) signaling and LXR/RXR (liver X receptor/retinoid X receptor) activation were identified as the top atherosclerosis-associated pathways in mice (both
<1.93×10
, TREM1 implicated early and LXR/RXR in late atherogenesis). The top upstream regulatory network in mice (sc-58125, a COX2 inhibitor) linked 64.0% of the genes into a single network. The pathways and networks identified in mice were interrogated by testing for associations between the genetically predicted gene expression of each mouse pathway-identified human homolog with clinical atherosclerosis in a cohort of 88 660 human subjects. Homologous human pathways and networks were significantly enriched for gene-atherosclerosis associations (empirical
<0.01 for TREM1 and LXR/RXR pathways and COX2 network). This included 12(60.0%) TREM1 pathway genes, 15(53.6%) LXR/RXR pathway genes, and 67(49.3%) COX2 network genes. Mouse analyses predicted, and human study validated, the strong association of COX2 expression (
) with increased likelihood of atherosclerosis (odds ratio, 1.68 per SD of genetically predicted gene expression;
=1.07×10
).
PRESCIANT (Preclinical Science Integration and Translation) leverages published preclinical investigations to identify high-confidence pathways, networks, and regulators of human disease.
Antibody-dependent enhancement (ADE) is a phenomenon that occurs when cross-reactive antibodies generated from a previous flaviviral infection increase the pathogenesis of a related virus. Zika virus ...(ZIKV) is the most recent flavivirus introduced to the Western Hemisphere and has become a significant public health threat due to the unanticipated impact on the developing fetus. West Nile virus (WNV) is the primary flavivirus that circulates in North America, and we and others have shown that antibodies against WNV are cross-reactive to ZIKV. Thus, there is concern that WNV immunity could increase the risk of severe ZIKV infection, particularly during pregnancy. In this study, we examined the extent to which WNV antibodies could impact ZIKV pathogenesis in a murine pregnancy model. To test this, we passively transferred WNV antibodies into pregnant
Stat2
-/-
mice on E6.5 prior to infection with ZIKV. Evaluation of pregnant dams showed weight loss following ZIKV infection; however, no differences in maternal weights or viral loads in the maternal brain, spleen, or spinal cord were observed in the presence of WNV antibodies. Resorption rates, and other fetal parameters, including fetal and placental size, were similarly unaffected. Further, the presence of WNV antibodies did not significantly alter the viral load or the inflammatory response in the placenta or the fetus in response to ZIKV. Our data suggest that pre-existing WNV immunity may not significantly impact the pathogenesis of ZIKV infection during pregnancy. Our findings are promising for the safety of implementing WNV vaccines in the continental US.
Exchange of atmospheric organic compounds between gas and particle phases is important in the production and chemistry of particle-phase mass but is poorly understood due to a lack of simultaneous ...measurements in both phases of individual compounds. Measurements of particle- and gas-phase organic compounds are reported here for the southeastern United States and central Amazonia. Polyols formed from isoprene oxidation contribute 8% and 15% on average to particle-phase organic mass at these sites but are also observed to have substantial gas-phase concentrations contrary to many models that treat these compounds as nonvolatile. The results of the present study show that the gas-particle partitioning of approximately 100 known and newly observed oxidation products is not well explained by environmental factors (e.g., temperature). Compounds having high vapor pressures have higher particle fractions than expected from absorptive equilibrium partitioning models. These observations support the conclusion that many commonly measured biogenic oxidation products may be bound in low-volatility mass (e.g., accretion products, inorganic–organic adducts) that decomposes to individual compounds on analysis. However, the nature and extent of any such bonding remains uncertain. Similar conclusions are reach for both study locations, and average particle fractions for a given compound are consistent within ∼25% across measurement sites.
Mpox virus (MPXV) caused a global outbreak in 2022. Although smallpox vaccines were rapidly deployed to curb spread and disease among those at highest risk, breakthrough disease was noted after ...complete immunization. Given the threat of additional zoonotic events and the virus's evolving ability to drive human-to-human transmission, there is an urgent need for an MPXV-specific vaccine that confers protection against evolving MPXV strains and related orthopoxviruses. Here, we demonstrate that an mRNA-lipid nanoparticle vaccine encoding a set of four highly conserved MPXV surface proteins involved in virus attachment, entry, and transmission can induce MPXV-specific immunity and heterologous protection against a lethal vaccinia virus (VACV) challenge. Compared with modified vaccinia virus Ankara (MVA), which forms the basis for the current MPXV vaccine, immunization with an mRNA-based MPXV vaccine generated superior neutralizing activity against MPXV and VACV and more efficiently inhibited spread between cells. We also observed greater Fc effector T
1-biased humoral immunity to the four MPXV antigens encoded by the vaccine, as well as to the four VACV homologs. Single MPXV antigen-encoding mRNA vaccines provided partial protection against VACV challenge, whereas multivalent vaccines combining mRNAs encoding two, three, or four MPXV antigens protected against disease-related weight loss and death equal or superior to MVA vaccination. These data demonstrate that an mRNA-based MPXV vaccine confers robust protection against VACV.
We investigated gay and bisexual men's willingness to self-administer an anal cancer screening test at home.
We conducted 2 national, online cross-sectional surveys of self-identified gay and ...bisexual men: Study I in 2009 with men ages 20 to 59 (n = 306) and Study II in 2013 with men ages 18 to 26 (n = 428). We used multivariate logistic regression analyses to determine variables associated with willingness to self-administer the screening test.
Most men were willing to self-administer an anal cancer screening test (78% Study I; 67% Study II). In Study I, willingness was higher among men who trusted anal Paps to find treatable cancer (adjusted odds ratio aOR = 1.47; 95% CI, 1.04-2.09) and who believed that men who have sex with men should be screened for anal cancer between 1 and 3 years vs. other intervals (aOR = 2.19; 95% CI, 1.17-4.10). In Study II, willingness was higher among men who perceived greater likelihood of anal cancer (aOR = 1.57; 95% CI, 1.12-2.20). Their most common concerns were not performing the test correctly and inaccuracy of results.
Many gay and bisexual men were willing to self-administer anal cancer screening tests at home. If routine screening is warranted, self-collected home testing could improve participation.
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