Activity-dependent gene regulation in neurons: energy coupling and a novel biosensor

Multiple brain disorders are associated with hypoinhibition of neural circuits that are controlled by inhibitory neurons using the neurotransmitter γ-aminobutyric acid (GABA). GABA activates type A receptors (GABARs) to mediate the majority of inhibitory neurotransmission and changes in GABAR subunit composition have profound effects on brain function. In fact, down-regulation of one of the three β isoforms, β1, is associated with alcoholism, autism, epilepsy, schizophrenia, and bipolar disorder. These conditions also present with mitochondrial defects and metabolic dysregulation. In the first Aim of my thesis, I ask whether the core promoter of the human GABAR β1 subunit gene (GABRB1) can be regulated by the same transcription factor, the nuclear respiratory factor 1 (NRF-1) that controls oxidative phosphorylation and mitochondrial biogenesis in neurons. The ENCODE database of NRF-1 binding in human embryonic stem cells was used to identify an interaction of NRF-1 with GABRB1. Using a variety of approaches: electro mobility shift, promoter/reporter luciferase assays, gene silencing and bioinformatics, we demonstrate that GABRB1 contains a canonical NRF-1 element responsible for the majority of GABRB1 promoter- luciferase activity in transfected primary neurons. Moreover, we show that endogenous NRF-1 is responsible for a substantial amount of luciferase activity in our studies. Altogether, our results suggest GABRB1 is a target gene for NRF-1, providing a possible link between mitochondria related energy metabolism and transcriptional regulation of β1-containing GABARs in neurological disease. Synthesis of NRF-1 is regulated by the transcription factor cAMP response element binding protein (CREB), an important memory molecule implicated in multiple brain disorders. The second Aim of my thesis was to develop a molecular sensor that can be used in living neurons to signal the presence of CREB dependent gene regulation. We employ a split complement bioluminescent sensor to monitor interaction of protein surfaces that link CREB with its co-factor CBP and demonstrate that it can detect activation of CREB via its serine 133 phosphorylation site and activation through an undiscovered mechanism. We also show that this sensor can be used to monitor BDNF signaling providing the foundation for its future use in in vivo models of disease where BDNF is implicated

Nuclear Respiratory Factor 1 (NRF-1) Controls the Activity Dependent Transcription of the GABA-A Receptor Beta 1 Subunit Gene in Neurons

While the exact role of β1 subunit-containing GABA-A receptors (GABARs) in brain function is not well understood, altered expression of the β1 subunit gene (GABRB1) is associated with neurological and neuropsychiatric disorders. In particular, down-regulation of β1 subunit levels is observed in brains of patients with epilepsy, autism, bipolar disorder and schizophrenia. A pathophysiological feature of these disease states is imbalance in energy metabolism and mitochondrial dysfunction. The transcription factor, nuclear respiratory factor 1 (NRF-1), has been shown to be a key mediator of genes involved in oxidative phosphorylation and mitochondrial biogenesis. Using a variety of molecular approaches (including mobility shift, promoter/reporter assays, and overexpression of dominant negative NRF-1), we now report that NRF-1 regulates transcription of GABRB1 and that its core promoter contains a conserved canonical NRF-1 element responsible for sequence specific binding and transcriptional activation. Our identification of GABRB1 as a new target for NRF-1 in neurons suggests that genes coding for inhibitory neurotransmission may be coupled to cellular metabolism. This is especially meaningful as binding of NRF-1 to its element is sensitive to the kind of epigenetic changes that occur in multiple disorders associated with altered brain inhibition

MCL1 Enhances the Survival of CD8+ Memory T Cells after Viral Infection

Viral infection results in the generation of massive numbers of activated effector CD8+ T cells that recognize viral components. Most of these are short-lived effector T cells (SLECs) that die after clearance of the virus. However, a small proportion of this population survives and forms antigen-specific memory precursor effector cells (MPECs), which ultimately develop into memory cells. These can participate in a recall response upon reexposure to antigen even at protracted times postinfection. Here, antiapoptotic myeloid cell leukemia 1 (MCL1) was found to prolong survival upon T cell stimulation, and mice expressing human MCL1 as a transgene exhibited a skewing in the proportion of CD8+ T cells, away from SLECs toward MPECs, during the acute phase of vaccinia virus infection. A higher frequency and total number of antigen-specific CD8+ T cells were observed in MCL1 transgenic mice. These findings show that MCL1 can shape the makeup of the CD8+ T cell response, promoting the formation of long-term memory

Delta intervention in Embarcadero

The design consists of two parts. The first part is mainly about why and how to build a seawall in Embarcadero district. The second part is how to create attractive waterfront activities and how to connect the city, the seawall, and the floating area as a whole. Each design decision is a result of research. The process of the design is also a way of research. Building a seawall and creating floating areas in Embarcadero is the best decisions dealing with the sea-level rise based on my site researchs.<br/

Diversity and abundance of aerobic anoxygenic phototrophic bacteria in two cyanobacterial bloom-forming lakes in China

Aerobic anoxygenic phototrophic (AAP) bacteria are widely distributed in marine and freshwater ecosystems. The aims of this study were to investigate the diversity and abundance of AAP bacteria in cyanobacterial bloom-forming eutrophic lakes and to study the association of AAP bacteria with the bloom-forming cyanobacteria. Analysis of pufM gene (the light-reaction center gene) clone libraries indicated that in eutrophic lakes (Lake Taihu and Lake Chaohu, China) with cyanobacterium Microcystis blooms, the AAP bacteria were related to members of Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. In Lake Taihu and Lake Chaohu, Alphaproteobacteria accounted for 81.5% and 75.0% of Microcystis-associated AAP bacteria, respectively, and 84.6% and 72.5% of free-living AAP bacteria, respectively. The predominance of Alphaproteobacteria in the two lakes was different from the previously reported predominance of Betaproteobacteria in freshwater lakes. Quantitative real-time PCR analysis indicated that in Lake Taihu and Lake Chaohu, AAP bacteria represented an important part of the bacterial community associated with Microcystis, and the abundance of Microcystis-associated AAP bacteria (18.3% and 11.7%, respectively) was higher than that of free-living AAP bacteria (5.1% and 7.9%, respectively). The abundance of AAP bacteria in the two bloom-forming lakes was higher than the previously reported level in other eutrophic freshwater bodies

High-Efficiency Reducing Strain for Producing Selenium Nanoparticles Isolated from Marine Sediment

Selenium nanoparticles (SeNPs) are all important for research because they exhibit a higher degree of absorption and lower toxicity than that of their organic and inorganic forms. At present, there are few reports on marine strains that can reduce Se(IV) to generate Se(0). In this study, a strain that reduces sodium selenite to SeNPs with high efficiency was screened from 40 marine strains. The SeNPs-S produced by the whole cells and SeNPs-E produced by the extracellular extract were characterized by FTIR, UV, Raman, XRD and SEM. Based on the results, the two kinds of SeNPs exhibited obvious differences in morphology, and their surfaces were capped with different biomacromolecules. Due to the difference in shape and surface coating, opposite results were obtained for the antibacterial activity of SeNPs-S and SeNPs-E against Gram-positive and Gram-negative bacteria. Both SeNPs-S and SeNPs-E exhibited no obvious cytotoxicity at concentrations up to 100 μg/mL, but SeNPs-E retained lower cytotoxicity when its concentration increased to 200 μg/mL. This is the first report on the detailed difference between the SeNPs produced by whole cells and cell extracts

Nuclear Respiratory Factor 1 (NRF-1) Controls the Activity Dependent Transcription of the GABA-A Receptor Beta 1 Subunit Gene in Neurons

While the exact role of β1 subunit-containing GABA-A receptors (GABARs) in brain function is not well understood, altered expression of the β1 subunit gene (GABRB1) is associated with neurological and neuropsychiatric disorders. In particular, down-regulation of β1 subunit levels is observed in brains of patients with epilepsy, autism, bipolar disorder and schizophrenia. A pathophysiological feature of these disease states is imbalance in energy metabolism and mitochondrial dysfunction. The transcription factor, nuclear respiratory factor 1 (NRF-1), has been shown to be a key mediator of genes involved in oxidative phosphorylation and mitochondrial biogenesis. Using a variety of molecular approaches (including mobility shift, promoter/reporter assays, and overexpression of dominant negative NRF-1), we now report that NRF-1 regulates transcription of GABRB1 and that its core promoter contains a conserved canonical NRF-1 element responsible for sequence specific binding and transcriptional activation. Our identification of GABRB1 as a new target for NRF-1 in neurons suggests that genes coding for inhibitory neurotransmission may be coupled to cellular metabolism. This is especially meaningful as binding of NRF-1 to its element is sensitive to the kind of epigenetic changes that occur in multiple disorders associated with altered brain inhibition

Efficacy and Safety of Surgical Ligation versus Endovascular Embolization for Type II Congenital Extrahepatic Portosystemic Shunt

Objective. To evaluate the safety and efficacy of surgical ligation and endovascular embolization for the treatment of type II congenital extrahepatic portosystemic shunt (CEPS). Methods. In this retrospective study, 23 patients diagnosed with type II CEPS between March 2011 and April 2019 were divided into either a surgical group (n=13; 41.5±19.9 years) or the interventional group (n=10; 44.9±19.7 years). The surgical group underwent laparoscopic surgical ligation of the shunt alone or ligation of the shunt and splenic artery and/or vein. The interventional group underwent endovascular embolization using microcoils, detachable coils, and vascular plug. Results. All 23 patients received a one-step shunt closure, and their clinical symptoms were significantly improved within 3-month postprocedure and without recurrence during follow-up. The serum ammonia levels in both groups decreased after the procedure and dropped to normal level at 6- to 12-month postprocedure. Compared with baseline, the portal vein diameter in interventional group increased significantly at 3-, 6-, 12-, and 36-month postocclusion (P=0.01 for all). The procedure time was shorter in the interventional group (127.0±43.2 minutes) than the surgical group (219.8±56.7 minutes; P<0.001). The intraoperative blood loss in the interventional group (32.0±62.5 mL) was less than that in the surgical group (238.5±396.9 mL; P=0.001). Conclusion. Both surgical ligation and endovascular embolization are effective in the treatment of type II CEPS. Endovascular embolization has the advantages of shorter procedure time and less intraoperative blood loss. The ligation of the portosystemic shunt and splenic artery and vein is feasible with apparent safety, and it could avoid a second surgical treatment

A Phytophthora infestans RXLR effector targets a potato ubiquitin-like domain-containing protein to inhibit the proteasome activity and hamper plant immunity

Ubiquitin-like domain-containing proteins (UDPs) are involved in the ubiquitin-proteasome system because of their ability to interact with the 26S proteasome. Here, we identified potato StUDP as a target of the Phytophthora infestans RXLR effector Pi06432 (PITG_06432), which supresses the salicylic acid (SA)-related immune pathway. By overexpressing and silencing of StUDP in potato, we show that StUDP negatively regulates plant immunity against P. infestans. StUDP interacts with, and destabilizes, the 26S proteasome subunit that is referred to as REGULATORY PARTICLE TRIPLE-A ATP-ASE (RPT) subunit StRPT3b. This destabilization represses the proteasome activity. Proteomic analysis and Western blotting show that StUDP decreases the stability of the master transcription factor SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1) in SA biosynthesis. StUDP negatively regulates the SA signalling pathway by repressing the proteasome activity and destabilizing StSARD1, leading to a decreased expression of the SARD1-targeted gene ISOCHORISMATE SYNTHASE 1 and thereby a decrease in SA content. Pi06432 stabilizes StUDP, and it depends on StUDP to destabilize StRPT3b and thereby supress the proteasome activity. Our study reveals that the P. infestans effector Pi06432 targets StUDP to hamper the homeostasis of the proteasome by the degradation of the proteasome subunit StRPT3b and thereby suppresses SA-related immunity

La Croix du Nord : supplément régional à la Croix de Paris ["puis" grand journal quotidien du Nord de la France]

27 janvier 19111911/01/27 (A22,N7391).Appartient à l’ensemble documentaire : NordPdeC