J Biol Chem
Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, Brazil.
Published: May 2002
Intercellular signaling is highly coordinated in excitable tissues such as heart, but the organization of intercellular signaling in epithelia is less clear. We examined Ca(2+) signaling in hepatoma cells expressing the hepatocyte gap junction protein connexin32 (cx32) or the cardiac gap junction protein cx43, plus a fluorescently tagged V(1a) vasopressin receptor (V(1a)R). Release of inositol 1,4,5-trisphosphate (InsP(3)) in wild type cells increased Ca(2+) in the injected cell but not in neighboring cells, while the Ca(2+) signal spread to neighbors when gap junctions were expressed. Photorelease of caged Ca(2+) rather than InsP(3) resulted in a small increase in Ca(2+) that did not spread to neighbors with or without gap junctions. However, photorelease of Ca(2+) in cells stimulated with low concentrations of vasopressin resulted in a much larger increase in Ca(2+), which spread to neighbors via gap junctions. Cells expressing tagged V(1a)R similarly had increased sensitivity to vasopressin, and could signal to neighbors via gap junctions. Higher concentrations of vasopressin elicited Ca(2+) signals in all cells. In cx32 or cx43 but not in wild type cells, this signaling was synchronized and began in cells expressing the tagged V(1a)R. Thus, intercellular Ca(2+) signals in epithelia are organized by three factors: 1) InsP(3) must be generated in each cell to support a Ca(2+) signal in that cell; 2) gap junctions are necessary to synchronize Ca(2+) signals among cells; and 3) cells with relatively increased expression of hormone receptor will initiate Ca(2+) signals and thus serve as pacemakers for their neighbors. Together, these factors may allow epithelia to act in an integrated, organ-level fashion rather than as a collection of isolated cells.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1074/jbc.M109207200 | DOI Listing |
J Hazard Mater
January 2025
College of Carbon Neutrality Future Technology, Sichuan University, Chengdu, Sichuan 610065, China; National Engineering Research Center for Flue Gas Desulfurization, Chengdu, Sichuan 610065, China; Industrial Technology Research Institute, Sichuan University, Yibin 644004, China. Electronic address:
This study investigates the critical relationship between the crystal phase, morphology, and photocatalytic activity of MnO. The δ-MnO nanosheets, characterized by multiple exposed crystal planes forming junctions, exhibit optimized optical and electrical properties. Oxygen vacancy concentrations were observed in the order δ-MnO > γ-MnO > α-MnO, with corresponding increases in band gap width from 1.
View Article and Find Full Text PDFPLoS Pathog
January 2025
Department of Translational Physiology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium.
Gap junctions (GJs) play a pivotal role in intercellular communication between eukaryotic cells, including transfer of biomolecules that contribute to the innate and adaptive immune response. However, if and how viruses affect gap junction intercellular communication (GJIC) remains largely unexplored. Here, we describe how the alphaherpesvirus pseudorabies virus (PRV) triggers ERK1/2-mediated phosphorylation of the main gap junction component connexin 43 (Cx43) and closure of GJIC, which depends on the viral protein pUL46.
View Article and Find Full Text PDFFront Cell Neurosci
January 2025
The Research Center for Brain Function and Medical Engineering, Asahikawa Medical University, Asahikawa, Japan.
The evolution of brain-expressed genes is notably slower than that of genes expressed in other tissues, a phenomenon likely due to high-level functional constraints. One such constraint might be the integration of information by neuron assemblies, enhancing environmental adaptability. This study explores the physiological mechanisms of information integration in neurons through three types of synchronization: chemical, electromagnetic, and quantum.
View Article and Find Full Text PDFFront Mol Neurosci
January 2025
Department of Otorhinolaryngology, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China.
Auditory neuropathy spectrum disorder (ANSD) is an auditory dysfunction disorder characterized by impaired speech comprehension. Its etiology is complex and can be broadly categorized into genetic and non-genetic factors. mutation is identified as a causative factor in ANSD.
View Article and Find Full Text PDFJ Physiol
January 2025
Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada.
Here we characterize seven Cx30.3 gene variants (R22H, S26Y, P61R, C86S, E99K, T130M and M190L) clinically associated with the rare skin disorder erythrokeratodermia variabilis et progressiva (EKVP) in tissue-relevant and differentiation-competent rat epidermal keratinocytes (REKs). We found that all variants, when expressed alone or together with wildtype (WT) Cx30.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.