A novel role for MLC1 in regulating astrocyte-synapse interactions.

Loss of function of the astrocyte membrane protein MLC1 is the primary genetic cause of the rare white matter disease Megalencephalic Leukoencephalopathy with subcortical Cysts (MLC), which is characterized by disrupted brain ion and water homeostasis. MLC1 is prominently present around fluid barriers in the brain, such as in astrocyte endfeet contacting blood vessels and in processes contacting the meninges. Whether the protein plays a role in other astrocyte domains is unknown.

Blockade of Na/H exchanger stimulates glioma tumor immunogenicity and enhances combinatorial TMZ and anti-PD-1 therapy.

The weak immunogenicity of gliomas presents a barrier for effective immunotherapy. Na/H exchanger isoform 1 (NHE1) maintains alkaline intracellular pH (pH) of glioma cells and acidic microenvironment. In addition, NHE1 is expressed in tumor-associated microglia and tumor-associated macrophages (TAMs) and involved in protumoral communications between glioma and TAMs.

Potential medium-term impacts of climate change on tuna and billfish in the Gulf of Mexico: A qualitative framework for management and conservation.

A systematic review of scientific papers on the potential impacts of climate-driven environmental changes on tuna and billfish in the Gulf of Mexico (GOM) was conducted to identify the climate-driven pressures and their associated potential impacts on the reproductive success and survival of tuna and billfish, and which of those impacts may have more relevance for their management and conservation in the GOM by 2050. An Impact Screening Analysis (ISA) was developed to evaluate the potential climate impacts discovered in the literature synthesis by assessing each impact against four criteria, and assigning it a ranking based on likelihood of occurrence (High, Medium, or Low). Results show three types of climate-driven pressures within the High ranking: increased water temperature; changes in ocean circulation and eddy kinetic energy; and changes in storm and wind patterns.

Selective role of Na /H exchanger in Cx3cr1 microglial activation, white matter demyelination, and post-stroke function recovery.

Na /H exchanger (NHE1) activation is required for multiple microglial functions. We investigated effects of selective deletion of microglial Nhe1 in Cx3cr1-Cre ;Nhe1 mice on neuroinflammation and tissue repair after ischemic stroke. Infarct volume was similar in corn oil or tamoxifen (Tam)-treated mice at 48 hr and 14 days post-stroke.

Glioma-mediated microglial activation promotes glioma proliferation and migration: roles of Na+/H+ exchanger isoform 1.

Microglia play important roles in extracellular matrix remodeling, tumor invasion, angiogenesis, and suppression of adaptive immunity in glioma. Na(+)/H(+) exchanger isoform 1 (NHE1) regulates microglial activation and migration. However, little is known about the roles of NHE1 in intratumoral microglial activation and microglia-glioma interactions.

CapE (capture, amplify, extract): A rapid method for detection of low level contamination of water with Verocytotoxigenic Escherichia coli (VTEC).

Verocytotoxigenic Escherichia coli (VTEC) is associated with a wide spectrum of disease from mild self-limiting diarrhoea to haemolytic uremic syndrome. Contaminated drinking water is accepted as an important route of transmission in Ireland as elsewhere however established methods for detection of VTEC in drinking water have limitations. We describe a sensitive and rapid method for detection of VTEC from large volumes (20 to 30L) of drinking water based on filtration, enrichment culture of filters and real-time PCR detection of VTEC virulence and O antigen determinants from enrichments.

Emerging roles of Na⁺/H⁺ exchangers in epilepsy and developmental brain disorders.

Epilepsy is a common central nervous system (CNS) disease characterized by recurrent transient neurological events occurring due to abnormally excessive or synchronous neuronal activity in the brain. The CNS is affected by systemic acid-base disorders, and epileptic seizures are sensitive indicators of underlying imbalances in cellular pH regulation. Na(+)/H(+) exchangers (NHEs) are a family of membrane transporter proteins actively involved in regulating intracellular and organellar pH by extruding H(+) in exchange for Na(+) influx.

Time-dependent changes in the mouse hippocampal synaptic membrane proteome after contextual fear conditioning.

A change in efficacy of hippocampal synapses is critical for memory formation. So far, the molecular analysis of synapses during learning has focused on small groups of proteins, whereas the dynamic global changes at these synapses have remained unknown. Here, we analyzed the temporal changes of the mouse hippocampal synaptic membrane proteome 1 and 4 h after contextual fear learning, comparing two groups; (1) a fear memory forming "delayed-shock" group and (2) a fear memory-deficient "immediate-shock" group.

Proteomic analysis of gliosomes from mouse brain: identification and investigation of glial membrane proteins.

Astrocytes are being increasingly recognized as crucial contributors to neuronal function at synapses, axons, and somas. Reliable methods that can provide insight into astrocyte proteins at the neuron-astrocyte functional interface are highly desirable. Here, we conducted a mass spectrometry analysis of Percoll gradient-isolated gliosomes, a viable preparation of glial subcellular particles often used to study mechanisms of astrocytic transmitter uptake and release and their regulation.

Novel cell separation method for molecular analysis of neuron-astrocyte co-cultures.

Over the last decade, the importance of astrocyte-neuron communication in neuronal development and synaptic plasticity has become increasingly clear. Since neuron-astrocyte interactions represent highly dynamic and reciprocal processes, we hypothesized that many astrocyte genes may be regulated as a consequence of their interactions with maturing neurons. In order to identify such neuron-responsive astrocyte genes in vitro, we sought to establish an expedited technique for separation of neurons from co-cultured astrocytes.

Functional characterization of single-nucleotide polymorphisms in the human undifferentiated embryonic-cell transcription factor 1 gene.

Single-nucleotide polymorphisms (SNPs) are single-nucleotide sequence variations between individuals. Two missense SNPs are present in the human undifferentiated embryonic-cell transcription factor 1 (UTF1) gene and their consequences for UTF1 function are investigated in this study. Expression of the UTF1 gene is restricted to pluripotent cells and UTF1 is a chromatin-associated protein with core histone-like properties.

The biogeography of ammonia-oxidizing bacterial communities in soil.

Although ammonia-oxidizing bacteria (AOB) are likely to play a key role in the soil nitrogen cycle, we have only a limited understanding of how the diversity and composition of soil AOB communities change across ecosystem types. We examined 23 soils collected from across North America and used sequence-based analyses to compare the AOB communities in each of the distinct soils. Using 97% 16S rRNA sequence similarity groups, we identified only 24 unique AOB phylotypes across all of the soils sampled.

Altered soil microbial community at elevated CO(2) leads to loss of soil carbon.

Increased carbon storage in ecosystems due to elevated CO(2) may help stabilize atmospheric CO(2) concentrations and slow global warming. Many field studies have found that elevated CO(2) leads to higher carbon assimilation by plants, and others suggest that this can lead to higher carbon storage in soils, the largest and most stable terrestrial carbon pool. Here we show that 6 years of experimental CO(2) doubling reduced soil carbon in a scrub-oak ecosystem despite higher plant growth, offsetting approximately 52% of the additional carbon that had accumulated at elevated CO(2) in aboveground and coarse root biomass.

The influence of tropical plant diversity and composition on soil microbial communities.

There is growing interest in understanding the linkages between above- and belowground communities, and very little is known about these linkages in tropical systems. Using an experimental site at La Selva Biological Station, Costa Rica, we examined whether plant diversity, plant community composition, and season influenced microbial communities. We also determined whether soil characteristics were related to differences in microbial communities.

An ecological perspective on bacterial biodiversity.

Bacteria may be one of the most abundant and species-rich groups of organisms, and they mediate many critical ecosystem processes. Despite the ecological importance of bacteria, past practical and theoretical constraints have limited our ability to document patterns of bacterial diversity and to understand the processes that determine these patterns. However, recent advances in molecular techniques that allow more thorough detection of bacteria in nature have made it possible to examine such patterns and processes.