Membrane depolarization of smooth muscle cells (myocytes) in the small arteries that regulate regional organ blood flow leads to vasoconstriction. Membrane depolarization also activates large-conductance calcium (Ca)-activated potassium (BK) channels, which limits Ca channel activity that promotes vasoconstriction, thus leading to vasodilation. We showed that in human and rat arterial myocytes, membrane depolarization rapidly increased the cell surface abundance of auxiliary BK β1 subunits but not that of the pore-forming BKα channels. Membrane depolarization stimulated voltage-dependent Ca channels, leading to Ca influx and the activation of Rho kinase (ROCK) 1 and 2. ROCK1/2-mediated activation of Rab11A promoted the delivery of β1 subunits to the plasma membrane by Rab11A-positive recycling endosomes. These additional β1 subunits associated with BKα channels already at the plasma membrane, leading to an increase in apparent Ca sensitivity and activation of the channels in pressurized arterial myocytes and vasodilation. Thus, membrane depolarization activates BK channels through stimulation of ROCK- and Rab11A-dependent trafficking of β1 subunits to the surface of arterial myocytes.
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http://dx.doi.org/10.1126/scisignal.aah5417 | DOI Listing |
Front Immunol
January 2025
IrsiCaixa, Badalona, Spain.
Introduction: HIV-1 exploits dendritic cells (DCs) to spread throughout the body via specific recognition of gangliosides present on the viral envelope by the CD169/Siglec-1 membrane receptor. This interaction triggers the internalization of HIV-1 within a structure known as the sac-like compartment. While the mechanism underlying sac-like compartment formation remains elusive, prior research indicates that the process is clathrin-independent and cell membrane cholesterol-dependent and involves transient disruption of cortical actin.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
School of Chemistry and Chemical Engineering, Anhui University, Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province, Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University) Ministry of Education, Hefei, 230601, PR China; School of Chemical and Environmental Engineering, Anhui Polytechnic University, 241000, Wuhu, PR China. Electronic address:
A pivotal pathway of photodynamic therapy (PDT) is to prompt mitochondrial damage by reactive oxygen species (ROS) generation, thus leading to cancer cell apoptosis. However, mitochondrial autophagy is induced during such a PDT process, which is a protective mechanism for cancer cell homeostasis, resulting in undermined therapeutic efficacy. Herein, we report a series of meticulously designed donor (D)-π-acceptor (A) photosensitizers (PSs), characterized by the strategic modulation of thiophene π-bridges, which exhibit unparalleled mitochondrial targeting proficiency.
View Article and Find Full Text PDFBiomolecules
January 2025
Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Rd., Wuhan 430030, China.
The sigma-1 receptor (Sig-1R) has emerged as a significant target in the realm of pain management and has been the subject of extensive research. Nonetheless, its specific function in inflammatory pain within dorsal root ganglion (DRG) neurons remains inadequately elucidated. This study utilized whole-cell patch clamp techniques, single-cell real-time PCR, and immunohistochemistry to examine the influence of Sig-1R on inflammatory pain induced by complete Freund's adjuvant (CFA) in a rat model.
View Article and Find Full Text PDFBiomedicines
January 2025
Department of Histology and Embryology, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-092 Bydgoszcz, Poland.
Under normal conditions, potassium is predominantly found within cells. The concentration gradient of sodium and potassium ions between intracellular and extracellular spaces enables signal transmission through membrane depolarization. The disruption of this transcellular process leads to elevated potassium ion levels in the extracellular space, and thus in the blood, a condition known as hyperkalemia.
View Article and Find Full Text PDFClin Neurophysiol
January 2025
Department of Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine and Neuroscience, University of Copenhagen, Denmark; Department of Neurology, Rigshospitalet, Copenhagen, Denmark.
Objective: To investigate motor axonal excitability in multifocal motor neuropathy (MMN) associated with involuntary muscle activity.
Methods: Two MMN patients with continuous involuntary finger movements (MMNifm) were compared to 11 patients without movements (MMNnfm). Clinical examination, EMG of the abductor pollicis brevis muscle, nerve conduction studies, motor unit number estimation, excitability studies, and mathematical modeling were conducted in the patients with MMN and compared to controls.
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