Restitution of intestinal epithelial barrier damage involves the coordinated remodeling of focal adhesions in actively migrating enterocytes. Defining the extracellular mediators and the intracellular signaling pathways regulating those dynamic processes is a key step in developing restitution-targeted therapies. Previously we have determined that activation of the chemokine receptor CXCR4 by the cognate ligand CXCL12 enhances intestinal epithelial restitution through reorganization of the actin cytoskeleton. The aim of these studies was to investigate the role of calcium effectors in CXCL12-mediated restitution. CXCL12 stimulated release of intracellular calcium in a dose-dependent manner. Inhibition of intracellular calcium flux impaired CXCL12-mediated migration of IEC-6 and CaCo2 cells. Pharmacological blockade and specific shRNA depletion of the phospholipase-C (PLCbeta3) isoform attenuated CXCL12-enhanced migration, linking receptor activation with intracellular calcium flux. Immunoblot analyses demonstrated CXCL12 activated the calcium-regulated focal adhesion protein proline-rich tyrosine kinase-2 (Pyk2) and the effector proteins paxillin and p130(Cas). Interruption of Pyk2 signaling potently blocked CXCL12-induced wound closure. CXCL12-stimulated epithelial cell migration was enhanced on laminin and abrogated by intracellular calcium chelation. These results suggest CXCL12 regulates restitution through calcium-activated Pyk2 localized to active focal adhesions. Calcium signaling pathways may therefore provide a novel avenue for enhancing barrier repair.
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http://dx.doi.org/10.1074/jbc.M109.061416 | DOI Listing |
Nat Rev Mol Cell Biol
January 2025
MitoCare Center, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
Activation of Ca channels in Ca stores in organelles and the plasma membrane generates cytoplasmic calcium ([Ca]) signals that control almost every aspect of cell function, including metabolism, vesicle fusion and contraction. Mitochondria have a high capacity for Ca uptake and chelation, alongside efficient Ca release mechanisms. Still, mitochondria do not store Ca in a prolonged manner under physiological conditions and lack the capacity to generate global [Ca] signals.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Guizhou Key Laboratory of New Quality Processing and Storage of Ecological Specialty Food; School of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China.
Traditional dry-curing methods have a long cycle time and low efficiency, resulting in the inconsistent quality of dry-cured ham. By applying electrical stimulation (ES) technology in the dry-curing process, it was found that ES affected mitochondrial apoptosis by modulating the intracellular environment of muscle cells, which, in turn, enhanced the quality of dry-cured pork loin. Specifically, ES accelerated glycogen and ATP depletion, which led to a rapid decline in pH.
View Article and Find Full Text PDFCell Signal
January 2025
Clinic School of Medicine and Affiliated Hospital, North China University of Science and Technology, Tangshan, China. Electronic address:
Purpose: This study aims to investigate whether zinc ion (Zn) alleviates myocardial ischemia-reperfusion injury (MIRI) through the MAM-associated signaling pathway and to explore its impact on ERS and calcium overload.
Methods: H9C2 cells were cultured in a DMEM supplemented with 10 % fetal bovine serum and 1 % antibiotic solution. A MIRI model was established through simulated ischemia and reoxygenation with Zn treatment in a complete medium.
PLoS One
January 2025
Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Muenster, Muenster, Germany.
Weibel-Palade bodies (WPB) are secretory organelles exclusively found in endothelial cells and among other cargo proteins, contain the hemostatic von-Willebrand factor (VWF). Stimulation of endothelial cells results in exocytosis of WPB and release of their cargo into the vascular lumen, where VWF unfurls into long strings of up to 1000 µm and recruits platelets to sites of vascular injury, thereby mediating a crucial step in the hemostatic response. The function of VWF is strongly correlated to its structure; in order to fulfill its task in the vascular lumen, VWF has to undergo a complex packing/processing after translation into the ER.
View Article and Find Full Text PDFJ Gen Physiol
March 2025
Department of Animal, Veterinary, and Food Sciences, College of Agricultural and Life Sciences, University of Idaho, Moscow, ID, USA.
The mechanisms underlying cooperative activation and inactivation of myocardial force extend from local, near-neighbor interactions involving troponin-tropomyosin regulatory units (RU) and crossbridges (XB) to more global interactions across the sarcomere. To better understand these mechanisms in the hearts of small and large mammals, we undertook a simplified mathematical approach to assess the contribution of three types of near-neighbor cooperative interactions, i.e.
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