Many cells coordinate their activities by transmitting rises in intracellular calcium from cell to cell. In nonexcitable cells, there are currently two models for intercellular calcium wave propagation, both of which involve release of inositol trisphosphate (IP3)- sensitive intracellular calcium stores. In one model, IP3 traverses gap junctions and initiates the release of intracellular calcium stores in neighboring cells. Alternatively, calcium waves may be mediated not by gap junctional communication, but rather by autocrine activity of secreted ATP on P2 purinergic receptors. We studied mechanically induced calcium waves in two rat osteosarcoma cell lines that differ in the gap junction proteins they express, in their ability to pass microinjected dye from cell to cell, and in their expression of P2Y2 (P2U) purinergic receptors. ROS 17/2.8 cells, which express the gap junction protein connexin43 (Cx43), are well dye coupled, and lack P2U receptors, transmitted slow gap junction-dependent calcium waves that did not require release of intracellular calcium stores. UMR 106-01 cells predominantly express the gap junction protein connexin 45 (Cx45), are poorly dye coupled, and express P2U receptors; they propagated fast calcium waves that required release of intracellular calcium stores and activation of P2U purinergic receptors, but not gap junctional communication. ROS/P2U transfectants and UMR/Cx43 transfectants expressed both types of calcium waves. Gap junction-independent, ATP-dependent intercellular calcium waves were also seen in hamster tracheal epithelia cells. These studies demonstrate that activation of P2U purinergic receptors can propagate intercellular calcium, and describe a novel Cx43-dependent mechanism for calcium wave propagation that does not require release of intracellular calcium stores by IP3. These studies suggest that gap junction communication mediated by either Cx43 or Cx45 does not allow passage of IP3 well enough to elicit release of intracellular calcium stores in neighboring cells.
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http://dx.doi.org/10.1083/jcb.139.2.497 | DOI Listing |
ISME J
January 2025
Université Aix-Marseille, CNRS, CEA, UMR7265 Institut de Biosciences and Biotechnologies d'Aix-Marseille, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France.
Intracellular calcium carbonate formation has long been associated with a single genus of giant Gammaproteobacteria, Achromatium. However, this biomineralization has recently received increasing attention after being observed in photosynthetic Cyanobacteriota and in two families of magnetotactic bacteria affiliated with the Alphaproteobacteria. In the latter group, bacteria form not only intracellular amorphous calcium carbonates into large inclusions that are refringent under the light microscope, but also intracellular ferrimagnetic crystals into organelles called magnetosomes.
View Article and Find Full Text PDFCurr Atheroscler Rep
January 2025
Department of Internal Medicine I, University Hospital Aachen, Pauwelsstraße, 30 52074, Aachen, Germany.
Purpose Of Review: This review explores the relationship between lipid-lowering therapies, particularly statins, and the risk of new-onset diabetes (NOD). It examines the underlying mechanisms and evaluates whether other lipid-lowering agents present similar risks.
Recent Findings: Recent meta-analyses further underscore a dose-dependent increase in NOD risk with statin therapy, particularly with high-intensity statins.
BMC Med
January 2025
Physiological Institute, University of Regensburg, University Street 31, 93053, Regensburg, Germany.
Background: Dystonia is a common neurological hyperkinetic movement disorder that can be caused by mutations in anoctamin 3 (ANO3, TMEM16C), a phospholipid scramblase and ion channel. We previously reported patients that were heterozygous for the ANO3 variants S651N, V561L, A599D and S651N, which cause dystonia by unknown mechanisms.
Methods: We applied electrophysiology, Ca measurements and cell biological methods to analyze the molecular mechanisms that lead to aberrant intracellular Ca signals and defective activation of K channels in patients heterozygous for the ANO3 variants.
Nutrients
December 2024
Department of Preventive Medicine, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea.
: Peroxisome proliferator-activated receptor γ (PPARγ) plays a key role in mediating anti-inflammatory and anticancer effects in the tumor microenvironment. Kaurenoic acid (KA), a diterpene compound isolated from (L.) Pruski, has been demonstrated to exert anti-inflammatory, anticancer, and antihuman immunodeficiency virus effects.
View Article and Find Full Text PDFMicroorganisms
November 2024
State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China.
, an opportunistic foodborne pathogen, has a strong resistance to osmotic stress and desiccation stress, but the current studies cannot elucidate this resistance mechanism absolutely. A mechanosensitive channel MscM was suspected of involving to desiccation resistance mechanism of To investigate the specific molecular mechanism, the mutant strain (Δ) was constructed using the homologous recombination method, and the complementary strain was obtained by gene complementation, followed by the analysis of the difference between the wild-type (WT), mutant, and complementary strains. Compared to the wild-type bacteria (WT), the inactivation rate of the Δ strain decreased by 15.
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