Glial fibrillary acidic protein (GFAP), a type III intermediate filament, is a marker of mature astrocytes. The expression of GFAP gene is regulated by many transcription factors (TFs), mainly Janus ...kinase‐2/signal transducer and activator of transcription 3 cascade and nuclear factor κ‐light‐chain‐enhancer of activated B cell signaling. GFAP expression is also modulated by protein kinase and other signaling molecules that are elicited by neuronal activity and hormones. Abnormal expression of GFAP proteins occurs in neuroinflammation, neurodegeneration, brain edema‐eliciting diseases, traumatic brain injury, psychiatric disorders and others. GFAP, mainly in α‐isoform, is the major component of cytoskeleton and the scaffold of astrocytes, which is essential for the maintenance of astrocytic structure and shape. GFAP also has highly morphological plasticity because of its quick changes in assembling and polymerizing states in response to environmental challenges. This plasticity and its corresponding cellular morphological changes endow astrocytes the functions of physical barrier between adjacent neurons and stabilizer of extracellular environment. Moreover, GFAP colocalizes and even molecularly associates with many functional molecules. This feature allows GFAP to function as a platform for direct interactions between different molecules. Last, GFAP involves transportation and localization of other functional proteins and thus serves as a protein transport guide in astrocytes. This guiding role of GFAP involves an elastic retraction and extension cytoskeletal network that couples with GFAP reassembling, transporting, and membrane protein recycling machinery. This paper reviews our current understanding of the expression and functions of GFAP as well as their regulation.
Main points
GFAP expression is regulated by transcription factors and enzymes at multiple levels;
GFAP serves as cytoskeleton, interactive platform, and protein location guide;
The guiding role of GFAP involves cellular transport and mobile machineries.
A central neural circuit for itch sensation Mu, Di; Deng, Juan; Liu, Ke-Fei ...
Science (American Association for the Advancement of Science),
08/2017, Volume:
357, Issue:
6352
Journal Article
Peer reviewed
Although itch sensation is an important protective mechanism for animals, chronic itch remains a challenging clinical problem. Itch processing has been studied extensively at the spinal level. ...However, how itch information is transmitted to the brain and what central circuits underlie the itch-induced scratching behavior remain largely unknown. We found that the spinoparabrachial pathway was activated during itch processing and that optogenetic suppression of this pathway impaired itch-induced scratching behaviors. Itch-mediating spinal neurons, which express the gastrin-releasing peptide receptor, are disynaptically connected to the parabrachial nucleus via glutamatergic spinal projection neurons. Blockade of synaptic output of glutamatergic neurons in the parabrachial nucleus suppressed pruritogen-induced scratching behavior. Thus, our studies reveal a central neural circuit that is critical for itch signal processing.
The catalytic C–F bond carboxylation of organofluorines with CO2 gas remains a challenging problem in synthetic chemistry. Here, we describe a selective defluorinative carboxylation of ...gem-difluoroalkenes through photoredox/palladium dual catalysis. The C–F bond activation is enabled by single electron reduction through photoredox catalysis to generate a fluorovinyl radical, which subsequently participates in an unprecedented palladium-catalyzed carboxylation. This novel C–F functionalization proved applicable to a wide range of substituted gem-difluoroalkenes, providing a rapid access to valuable α-fluoroacrylic acids.
A PdII‐catalyzed asymmetric aminohydroxylation of 1,3‐dienes with N‐tosyl‐2‐aminophenols was developed by making use of a chiral pyridinebis(oxazoline) ligand. The highly regioselective reaction ...provides direct and efficient access to chiral 3,4‐dihydro‐2H‐1,4‐benzoxazines in high yield and enantioselectivity (up to 96:4 e.r.). The reaction employs readily available N‐tosyl‐2‐aminophenols as a unique aminohydroxylation reagent and is complementary to known asymmetric aminohydroxylation methods.
Give me a ring: A palladium‐catalyzed asymmetric aminohydroxylation reaction of 1,3‐dienes with N‐tosyl‐2‐aminophenols was developed by employing a chiral pyridinebis(oxazoline) ligand. This reaction furnishes optically active 3,4‐dihydro‐2H‐1,4‐benzoxazines in high yields and with high levels of regio‐ and stereoselectivity.
Dendrobium is known for its pharmacological actions including anti-cancer effect, anti-fatigue effect, gastric ulcer protective effect, and so on. At present, only studies on endophytic fungi of ...Dendrobium affecting the metabolites of host plants have been reported, very little research has been done on endophytic bacteria. In this study, we have demonstrated the great diversity of endophytic bacteria in 6 Dendrobium samples from different origins and cultivars. According to the results of the culture-independent method, the endophytic bacterial community in Dendrobium stems showed obvious different in the 6 samples and was influenced by origin and cultivar. Some bacteria including Ralstonia, Comamonas and Lelliottia were first detected in Dendrobium in this study. Based on the culture-dependent method, a total of 165 cultivable endophytic bacteria isolates were isolated from the sterilized Dendrobium stems, and were classified into 43 species according to the 16S rRNA gene sequence analysis. Moreover, 14 of the 43 strains showed antimicrobial activity against phytopathogen using the Kirby-Bauer method. Strain NA-HTong-7 (Bacillus megaterium, 99.12%) showed the highest antimicrobial activity. This study was the first comprehensive study on endophytic bacteria of Dendrobium from different origins and cultivars, which provides new insights into the endophytic bacteria from Dendrobium.
It remains unclear whether the necessity of calcified mellitus induced by high inorganic phosphate (Pi) is required and the roles of autophagy plays in aldosterone (Aldo)‐enhanced vascular ...calcification (VC) and vascular smooth muscle cell (VSMC) osteogenic differentiation. In the present study, we found that Aldo enhanced VC both in vivo and in vitro only in the presence of high Pi, alongside with increased expression of VSMC osteogenic proteins (BMP2, Runx2 and OCN) and decreased expression of VSMC contractile proteins (α‐SMA, SM22α and smoothelin). However, these effects were blocked by mineralocorticoid receptor inhibitor, spironolactone. In addition, the stimulatory effects of Aldo on VSMC calcification were further accelerated by the autophagy inhibitor, 3‐MA, and were counteracted by the autophagy inducer, rapamycin. Moreover, inhibiting adenosine monophosphate‐activated protein kinase (AMPK) by Compound C attenuated Aldo/MR‐enhanced VC. These results suggested that Aldo facilitates high Pi‐induced VSMC osteogenic phenotypic switch and calcification through MR‐mediated signalling pathways that involve AMPK‐dependent autophagy, which provided new insights into Aldo excess‐associated VC in various settings.
C−H/C−C functionalizations with methylenecyclopropanes (MCPs) were accomplished with a versatile base‐metal catalyst. A robust manganese(I) complex enabled the expedient annulation of MCPs by ...synthetically meaningful ketimines to deliver, upon one‐pot hydroarylation, densely substituted polycylic anilines in a step‐economical fashion. Mechanistic studies provided strong support for a facile organometallic C−H manganation, while typical cobalt, ruthenium, rhodium, and palladium catalysts were found completely ineffective.
One stone, two birds: C−H/C−C activations were realized by a versatile MnI catalysis regime, thus enabling the stereoselective construction of polycyclic anilines. Mechanistic studies provided strong support for a facile C−H manganation while typical Co, Ru, Rh, and Pd catalysts were completely ineffective.
Mobile colistin resistance (mcr) genes represent an emerging challenge. Here we describe a novel mcr gene, mcr-10, on an IncFIA plasmid of an Enterobacter roggenkampii clinical strain. mcr-10 has the ...highest nucleotide identity (79.69%) with mcr-9 and encodes MCR-10 with 82.93% amino acids identical to MCR-9. mcr-10 confers 4-fold increase in colistin MIC (from 1 to 4 mg/L) when cloned into a colistin-susceptible E. roggenkampii strain. By screening GenBank, mcr-10 was found in various Enterobacteriaceae species of countries in four continents, suggesting that this gene has widely spread. MCR-10 shows 79.04% to 83.67% amino acid identity and highly conserved predicted protein structures with chromosomally encoded MCR-like phosphoethanolamine transferases (designated MCR-B here) of various Buttiauxella species. MCR-10, MCR-9 and MCR-B proteins may, therefore, originate from a common ancestor. mcr-10 was adjacent to a site-specific recombinase-encoding gene and was bracketed by IS903 and may be mobilized by site-specific recombination or composite transposon. Our results indicate that mcr-10 is a novel plasmid-borne colistin resistance gene and warrants immediate monitoring and further studies.
Group 2 innate lymphoid cells (ILC2s) are emerging as key players in the pathogenesis of allergic airway inflammation. The mechanisms regulating ILC2, however, are not fully understood. Here, we ...found that ICAM-1 is required for the development and function of ILC2. ICAM-1-deficient (
) mice displayed significantly lower levels of ILC2s in the bone marrow and peripheral tissues than wild-type controls. CLP transfer and in vitro culture assays revealed that the regulation of ILC2 by ICAM-1 is cell intrinsic. Furthermore, ILC2s from
mice were functionally impaired, as indicated by the diminished production of type-2 cytokines in response to IL-33 challenge. The reduction in lung ILC2s caused a clear remission of airway inflammation in
mice after administration of papain or
We further demonstrate that ILC2 defects caused by ICAM-1 deficiency are due to ERK signaling-dependent down-regulation of GATA3 protein. Collectively, these observations identify ICAM-1 as a novel regulator of ILC2.
Heterostructures composed of two‐dimensional black phosphorus (2D BP) with unique physical/chemical properties are of great interest. Herein, we report a simple solvothermal method to synthesize ...in‐plane BP/Co2P heterostructures for electrocatalysis. By using the reactive edge defects of the BP nanosheets as the initial sites, Co2P nanocrystals are selectively grown on the BP edges to form the in‐plane BP/Co2P heterostructures. Owing to disposition on the original defects of BP, Co2P improves the conductivity and offers more active electrocatalytic sites, so that the BP/Co2P nanosheets exhibit better and more stable electrocatalytic activities in the hydrogen evolution and oxygen evolution reactions. Our work not only extends the application of BP to electrochemistry, but also provides a new idea to improve the performance of BP by utilization of defects. Furthermore, this strategy can be extended to produce other BP heterostructures to expand the corresponding applications.
In‐plane black phosphorus (BP)/Co2P heterostructures were synthesized using the reactive edge defects of the BP nanosheets as the initial sites. Co2P selectively grown on the BP edges improves the conductivity and offers more active electrocatalytic sites. The BP/Co2P nanosheets exhibit a better and more stable electrocatalytic activity in hydrogen and oxygen evolution reactions.
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