keyword
MENU ▼
Read by QxMD icon Read
search

gap junctions

keyword
https://www.readbyqxmd.com/read/29044647/epilepsy-and-astrocyte-energy-metabolism
#1
Detlev Boison, Christian Steinhäuser
Epilepsy is a complex neurological syndrome characterized by neuronal hyperexcitability and sudden, synchronized electrical discharges that can manifest as seizures. It is now increasingly recognized that impaired astrocyte function and energy homeostasis play key roles in the pathogenesis of epilepsy. Excessive neuronal discharges can only happen, if adequate energy sources are made available to neurons. Conversely, energy depletion during seizures is an endogenous mechanism of seizure termination. Astrocytes control neuronal energy homeostasis through neurometabolic coupling...
October 17, 2017: Glia
https://www.readbyqxmd.com/read/29043825/unconventional-current-scaling-and-edge-effects-for-charge-transport-through-molecular-clusters
#2
Veronika Obersteiner, Georg Huhs, Nick R Papior, Egbert Zojer
Metal-molecule-metal junctions are the key components of molecular electronics circuits. Gaining a microscopic understanding of their conducting properties is central to advancing the field. In the present contribution we highlight the fundamental differences between single-molecule and ensemble junctions focusing on the fundamentals of transport through molecular clusters. In this way, we elucidate the collective behavior of parallel molecular wires, bridging the gap between single molecule and large-area monolayer electronics, where even in the latter case transport is usually dominated by finite-size islands...
October 18, 2017: Nano Letters
https://www.readbyqxmd.com/read/29042625/radiation-resistance-of-silicon-carbide-schottky-diode-detectors-in-d-t-fusion-neutron-detection
#3
Linyue Liu, Ao Liu, Song Bai, Ling Lv, Peng Jin, Xiaoping Ouyang
Silicon carbide (SiC) is a wide band-gap semiconductor material with many excellent properties, showing great potential in fusion neutron detection. The radiation resistance of 4H-SiC Schottky diode detectors was studied experimentally by carefully analyzing the detectors' properties before and after deuterium-tritium fusion neutron irradiation with the total fluence of 1.31 × 10(14) n/cm(2) and 7.29 × 10(14) n/cm(2) at room temperature. Significant degradation has been observed after neutron irradiation: reverse current increased greatly, over three to thirty fold; Schottky junction was broken down; significant lattice damage was observed at low temperature photoluminescence measurements; the peaks of alpha particle response spectra shifted to lower channels and became wider; the charge collection efficiency (CCE) decreased by about 7...
October 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29042599/progesterone-via-its-type-a-receptor-promotes-myometrial-gap-junction-coupling
#4
Lubna Nadeem, Oksana Shynlova, Sam Mesiano, Stephen Lye
Effective labour contractions require synchronization of myometrial cells through gap junctions (GJs). Clasically, progesterone (P4) is known to inhibit the expression of connexin-43 (Cx43, major component of GJs) and GJ formation in myometrium. Our current study is based on a striking observation that challenges this dogma. We observed conspicuous differences in the intracellular localization of Cx43 protein in PRA versus PRB expressing myocytes. Thus in P4 stimulated PRA cells Cx43 protein forms GJs, whereas in PRB cells the forward trafficking of Cx43 and GJ formation is inhibited even when Cx43 is overexpressed...
October 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29037777/multipotency-of-skeletal-muscle-stem-cells-on-their-native-substrate-and-the-expression-of-connexin-43-during-adoption-of-adipogenic-and-osteogenic-fate
#5
Mohamed I Elashry, Manuela Heimann, Sabine Wenisch, Ketan Patel, Stefan Arnhold
Muscle regeneration is performed by resident muscle stem cells called satellite cells (SC). However they are multipotent, being able to adopt adipogenic and osteogenic fate under the correct stimuli. Since SC behavior can be regulated by the extra-cellular matrix, we examined the robustness of the myogenic programme of SC on their native substrate-the surface of a myofiber. We show that the native substrate supports myogenic differentiation judged by the expression of members of the Myogenic Determination Factor (MRF) family...
October 13, 2017: Acta Histochemica
https://www.readbyqxmd.com/read/29036409/structure-of-an-innexin-gap-junction-channel-and-cryo-em-sample-preparation
#6
Atsunori Oshima
Gap junction channels are essential for mediating intercellular communication in most multicellular organisms. Two gene families encode gap junction channels, innexin and connexin. Although the sequence similarity between these two families based on bioinformatics is not conclusively determined, the gap junction channels encoded by these two gene families are structurally and functionally analogous. We recently reported an atomic structure of an invertebrate innexin gap junction channel using single-particle cryo-electron microscopy...
September 21, 2017: Microscopy
https://www.readbyqxmd.com/read/29036029/-anterior-skull-base-and-pericranial-flap-ossification-after-frontofacial-monobloc-advancement
#7
Anne Morice, Giovanna Paternoster, Agnès Ostertag, Syril James, Martine Cohen-Solal, Roman H Khonsari, Eric Arnaud
BACKGROUND: Frontofacial monobloc advancement (FFMBA) creates a communication between the anterior cranial fossa and nasal cavities. To tackle this issue, trans-orbital pericranial pedicled flaps (PF) are routinely performed in our center. This study aimed to assess the post-operative ossification of the anterior skull base and PF following FFMBA, and to identify factors influencing this ossification. METHODS: Measurements of the skull base only (SB) and of the ossified PF together with the SB (SB-OPF) were performed on CT scans at the naso-frontal (NF) and the naso-ethmoïdo-frontal (NEF) junctions...
October 12, 2017: Plastic and Reconstructive Surgery
https://www.readbyqxmd.com/read/29035140/cytoskeleton-genes-expression-and-survival-rate-comparison-between-immature-and-mature-yak-oocyte-after-ops-vitrification
#8
Xia Wei, Ye Sijie, Zeng Weibin, Xu Qing, Zheng Jie, Zi Xiangdong
This study was conducted to investigate the effect of vitrification on survival rate and cytoskeleton gene expression during yak oocyte maturation. The yak oocytes were incubated for 0 h [germinal vesicle (GV) stage] and in vitro matured for 24 h [metaphase II (MII) stage] to obtain immature and mature oocytes. Survival rate after vitrification were compared between immature and mature yak oocytes and cytoskeleton-related genes [cytokeratin 8 (CK8), β-actin (ACTB), and gap junction protein, alpha 1 (GJA1)] were tested by real-time PCR...
October 16, 2017: Animal Biotechnology
https://www.readbyqxmd.com/read/29034528/patients-with-a-new-variant-of-endemic-pemphigus-foliaceus-have-autoantibodies-against-arrector-pili-muscle-colocalizing-with-myzap-p0071-desmoplakins-1-and-2-and-arvcf
#9
A M Abreu-Velez, C A Valencia-Yepes, Y A Upegui-Zapata, E Upegui-Quiceno, N R Mesa-Herrera, J E Velazquez-Velez, M S Howard
BACKGROUND: We identified a new variant of endemic pemphigus foliaceus in El Bagre, Colombia, South America, which we term El Bagre-EPF, and observed reactivity to arrector pili muscle (APM), thus we tested for autoimmunity to APM. METHODS: We took skin biopsies from 30 patients with El Bagre-EPF and 30 healthy controls (HCs) matched by age, sex and occupation, who were all from the endemic area, and tested these using direct immunofluorescence (DIF), confocal microscopy, immunohistochemistry and immunoblotting (IB)...
October 15, 2017: Clinical and Experimental Dermatology
https://www.readbyqxmd.com/read/29030562/astrocyte-calcium-waves-propagate-proximally-by-gap-junction-and-distally-by-extracellular-diffusion-of-atp-released-from-volume-regulated-anion-channels
#10
Yuki Fujii, Shohei Maekawa, Mitsuhiro Morita
Wave-like propagation of [Ca(2+)]i increases is a remarkable intercellular communication characteristic in astrocyte networks, intercalating neural circuits and vasculature. Mechanically-induced [Ca(2+)]i increases and their subsequent propagation to neighboring astrocytes in culture is a classical model of astrocyte calcium wave and is known to be mediated by gap junction and extracellular ATP, but the role of each pathway remains unclear. Pharmacologic analysis of time-dependent distribution of [Ca(2+)]i revealed three distinct [Ca(2+)]i increases, the largest being in stimulated cells independent of extracellular Ca(2+) and inositol 1,4,5-trisphosphate-induced Ca(2+) release...
October 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29030126/the-pesticide-lindane-induces-dose-dependent-damage-to-granulosa-cells-in-an-in-vitro-culture
#11
Maria Grazia Palmerini, Gulmira Zhurabekova, Aru Balmagambetova, Stefania Annarita Nottola, Selenia Miglietta, Manuel Belli, Serena Bianchi, Sandra Cecconi, Valentina Di Nisio, Giuseppe Familiari, Guido Macchiarelli
Lindane, which is one of the most persistent organochlorine pesticide contaminating the Aral Sea region, is associated with numerous pathologies of the female reproductive system, including infertility, due to its gap junction blocker activity. By using an in vitro model of reproductive toxicity consisting of mouse parietal granulosa cells (GCs) exposed to increasing concentrations of Lindane ranging from 1 to 100μM (L1; L10; L100), we aimed to ascertain the Lindane toxicity by evaluating the ultrastructure and expression of the cell death protein p53...
October 10, 2017: Reproductive Biology
https://www.readbyqxmd.com/read/29025971/role-of-connexin-43-in-different-forms-of-intercellular-communication-gap-junctions-extracellular-vesicles-and-tunnelling-nanotubes
#12
REVIEW
Teresa M Ribeiro-Rodrigues, Tânia Martins-Marques, Sandrine Morel, Brenda R Kwak, Henrique Girão
Communication is important to ensure the correct and efficient flow of information, which is required to sustain active social networks. A fine-tuned communication between cells is vital to maintain the homeostasis and function of multicellular or unicellular organisms in a community environment. Although there are different levels of complexity, intercellular communication, in prokaryotes to mammalians, can occur through secreted molecules (either soluble or encapsulated in vesicles), tubular structures connecting close cells or intercellular channels that link the cytoplasm of adjacent cells...
October 12, 2017: Journal of Cell Science
https://www.readbyqxmd.com/read/29025706/no-augments-endothelial-reactivity-by-reducing-myoendothelial-calcium-signal-spreading-a-novel-role-for-cx37-connexin-37-and-shp-2
#13
Kristin Pogoda, Hanna Mannell, Stephanie Blodow, Holger Schneider, Kai Michael Schubert, Jiehua Qiu, Andreas Schmidt, Axel Imhof, Heike Beck, Laurentia Irina Tanase, Alexander Pfeifer, Ulrich Pohl, Petra Kameritsch
OBJECTIVE: Because of its strategic position between endothelial and smooth muscle cells in microvessels, Cx37 (Connexin 37) plays an important role in myoendothelial gap junctional intercellular communication. We have shown before that NO inhibits gap junctional intercellular communication through gap junctions containing Cx37. However, the underlying mechanism is not yet identified. APPROACH AND RESULTS: Using channel-forming Cx37 mutants exhibiting partial deletions or amino acid exchanges in their C-terminal loops, we now show that the phosphorylation state of a tyrosine residue at position 332 (Y332) in the C terminus of Cx37 controls the gap junction-dependent spread of calcium signals...
October 12, 2017: Arteriosclerosis, Thrombosis, and Vascular Biology
https://www.readbyqxmd.com/read/29025060/adrenomedullin-improves-fertility-and-promotes-pinopodes-and-cell-junctions-in-the-peri-implantation-endometrium
#14
Brooke C Matson, Stephanie L Pierce, Scott T Espenschied, Eric Holle, Imani H Sweatt, Eric S Davis, Robert Tarran, Steven L Young, Trudy A Kohout, Marcel van Duin, Kathleen M Caron
Implantation is a complex event demanding contributions from both embryo and endometrium. Despite advances in assisted reproduction, endometrial receptivity defects persist as a barrier to successful implantation in women with infertility. We previously demonstrated that maternal haploinsufficiency for the endocrine peptide adrenomedullin (AM) in mice confers a sub-fertility phenotype characterized by defective uterine receptivity and sparse epithelial pinopode coverage. The strong link between AM and implantation suggested the compelling hypothesis that administration of AM prior to implantation may improve fertility, protect against complications, and ultimately lead to better maternal and fetal outcomes...
August 28, 2017: Biology of Reproduction
https://www.readbyqxmd.com/read/29025011/significance-of-epidermal-growth-factor-receptor-signaling-for-acquisition-of-meiotic-and-developmental-competence-in-mammalian-oocytes
#15
Radek Prochazka, Milan Blaha, Lucie Nemcová
The surge in luteinizing hormone (LH) in preovulatory ovarian follicles triggers the resumption of oocyte meiosis accompanied by expansion of surrounding cumulus cells and ovulation of cumulus-oocyte complexes (COCs) into the oviduct. Over the last 15 years, substantial progress has been made in elucidating the key pathways by which the LH signal spreads within the preovulatory follicle and in identifying the molecules responsible for maintaining oocyte arrest and meiosis resumption. It is now clear that the adenylcyclase-mediated rise in intracellular cAMP leads to activation of the epidermal growth factor receptor (EGFR) network in granulosa and cumulus cells...
August 31, 2017: Biology of Reproduction
https://www.readbyqxmd.com/read/29023478/regeneration-of-glycocalyx-by-heparan-sulfate-and-sphingosine-1-phosphate-restores-inter-endothelial-communication
#16
Solomon A Mensah, Ming J Cheng, Homa Homayoni, Brian D Plouffe, Arthur J Coury, Eno E Ebong
Vasculoprotective endothelium glycocalyx (GCX) shedding plays a critical role in vascular disease. Previous work demonstrated that GCX degradation disrupts endothelial cell (EC) gap junction connexin (Cx) proteins, likely blocking interendothelial molecular transport that maintains EC and vascular tissue homeostasis to resist disease. Here, we focused on GCX regeneration and tested the hypothesis that vasculoprotective EC function can be stimulated via replacement of GCX when it is shed. We used EC with [i] intact heparan sulfate (HS), the most abundant GCX component; [ii] degraded HS; or [iii] HS that was restored after enzyme degradation, by cellular self-recovery or artificially...
2017: PloS One
https://www.readbyqxmd.com/read/29023238/severe-phenotype-of-keratitis-ichthyosis-deafness-syndrome-with-presumed-ocular-surface-squamous-neoplasia
#17
Ana Silvia Serrano-Ahumada, Vianney Cortes-González, Luz María González-Huerta, Sergio Cuevas, Luis Aguilar-Lozano, Cristina Villanueva-Mendoza
PURPOSE: The aim of this study was to describe a case of severe keratitis-ichthyosis-deafness (KID) syndrome with ocular surface squamous neoplasia. METHODS: The affected patient underwent complete ocular and systemic examinations. The molecular studies included polymerase chain reaction amplification and automated DNA sequencing of the complete gap junction beta-2 (GJB2) gene coding sequence. RESULTS: A 30-year-old man presented with generalized erythro-hyperkeratosis and deafness and complaints of decreased visual acuity, tearing, and photophobia...
October 10, 2017: Cornea
https://www.readbyqxmd.com/read/29022008/inflammatory-activation-of-human-cardiac-fibroblasts-leads-to-altered-calcium-signaling-decreased-connexin-43-expression-and-increased-glutamate-secretion
#18
Eva Skiöldebrand, Annika Lundqvist, Ulrika Björklund, Mikael Sandstedt, Anders Lindahl, Elisabeth Hansson, Lillemor Mattsson Hultén
Cardiac fibroblasts, which are abundant in heart tissue, are involved not only in extracellular matrix homeostasis and repair, but also in cardiac remodeling after a myocardial infarction that, in turn, can lead to loss of cardiac function and heart failure. Ca(2+) signaling is functionally important in many cell types, but the roles of fibroblast signaling and inflammation in the pathogenesis of heart disease are unclear. Here, we tested the hypothesis that inflammatory activation affects cardiac fibroblasts, both in terms of Ca(2+) signaling and their capacity for intercellular communication through the gap junction channel protein connexin 43 (Cx43)...
October 2017: Heliyon
https://www.readbyqxmd.com/read/29021339/phosphorylation-regulates-connexin43-zo-1-binding-and-release-an-important-step-in-gap-junction-turnover
#19
Anastasia F Thévenin, Rachel A Margraf, Charles G Fisher, Rachael M Kells-Andrews, Matthias M Falk
To investigate whether connexin phosphorylation regulates ZO-1's known role in gap junction (GJ) function, we generated and analyzed a series of phosphomimetic and phosphorylation-dead mutants by exchanging known conserved regulatory serine (S) residues 255, 279/282, 365, 368, and 373 located in the C-terminal domain of connexin43 (Cx43) into glutamic acid (E) or alanine (A) residues. All connexin mutants were translated into stable, full-length proteins and assembled into GJs when expressed in HeLa or MDCK cells...
October 11, 2017: Molecular Biology of the Cell
https://www.readbyqxmd.com/read/29018347/mechanisms-of-the-testis-toxicity-induced-by-chronic-exposure-to-mequindox
#20
Qianying Liu, Zhixin Lei, Anxiong Huang, Qirong Lu, Xu Wang, Saeed Ahmed, Ihsan Awais, Zonghui Yuan
Mequindox (MEQ) is a synthetic antimicrobial agent widely used in China since the 1980s. Although the toxicity of MEQ is well recognized, its testis toxicity has not been adequately investigated. In the present study, we provide evidence that MEQ triggers oxidative stress, mitochondrion dysfunction and spermatogenesis deficiency in mice after exposure to MEQ (0, 25, 55, and 110 mg/kg in the diet) for up to 18 months. The genotoxicity and adrenal toxicity may contribute to sperm abnormalities caused by MEQ. Moreover, using LC/MS-IT-TOF analysis, two metabolites, 3-methyl-2-(1-hydroxyethyl) quinoxaline-N4-monoxide (M4) and 3-methyl-2-(1-hydroxyethyl) quinoxaline-N1-monoxide (M8), were detected in the serum of mice, which directly confirms the relationship between the N→O group reduction metabolism of MEQ and oxidative stress...
2017: Frontiers in Pharmacology
keyword
keyword
30648
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"