Polycystin-2, a member of the TRP family of calcium channels, is encoded by the human PKD2 gene. Mutations in that gene can lead to swelling of nephrons into the fluid-filled cysts of polycystic kidney disease. In addition to expression in tubular epithelial cells, human polycystin-2 is found in muscle and neuronal cells, but its cell biological function has been unclear. A homologue in Caenorhabditis elegans is necessary for male mating behavior. We compared the behavior, calcium signaling mechanisms, and electrophysiology of wild-type and pkd-2 knockout C. elegans. In addition to characterizing PKD-2-mediated aggregation and mating behaviors, we found that polycystin-2 is an intracellular Ca(2+) release channel that is required for the normal pattern of Ca(2+) responses involving IP(3) and ryanodine receptor-mediated Ca(2+) release from intracellular stores. Activity of polycystin-2 creates brief cytosolic Ca(2+) transients with increased amplitude and decreased duration. Polycystin-2, along with the IP(3) and ryanodine receptors, acts as a major calcium-release channel in the endoplasmic reticulum in cells where rapid calcium signaling is required, and polycystin-2 activity is essential in those excitable cells for rapid responses to stimuli.
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http://dx.doi.org/10.1016/j.ceca.2005.03.003 | DOI Listing |
Cell Calcium
December 2024
Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557, USA. Electronic address:
Interstitial cells of Cajal in the plane of the myenteric plexus (ICC-MY) serve as electrical pacemakers in the stomach and small intestine. A similar population of cells is found in the colon, but these cells do not appear to generate regular slow wave potentials, as characteristic in more proximal gut regions. Ca handling mechanisms in ICC-MY of the mouse proximal colon were studied using confocal imaging of muscles from animals expressing GCaMP6f exclusively in ICC.
View Article and Find Full Text PDFBiomaterials
January 2025
Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, 500 Quxi Road, Shanghai, 200011, China. Electronic address:
Addressing the concurrent repair of cartilage and subchondral bone presents a significant challenge yet is crucial for the effective treatment of severe joint injuries. This study introduces a novel biodegradable composite scaffold, integrating piezoelectric poly-l-lactic acid (pPLLA) with strontium-enriched silicate bioceramic (SrSiO). This innovative scaffold continually releases bioactive Sr and SiO ions while generating an electrical charge under low-intensity pulsed ultrasound (LIPUS) stimulation, a clinically recognized method.
View Article and Find Full Text PDFJ Cell Biol
March 2025
Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.
Many cancer cells exhibit increased amounts of paucimannose glycans, which are truncated N-glycan structures rarely found in mammals. Paucimannosidic proteins are proposedly generated within lysosomes and exposed on the cell surface through a yet uncertain mechanism. In this study, we revealed that paucimannosidic proteins are produced by lysosomal glycosidases and secreted via lysosomal exocytosis.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Indiana University, Bloomington, IN, USA.
Background: The roles of Aβ in the pathogenesis of Alzheimer 's disease (AD) include disruption of synaptic communication/function and synaptic plasticity mechanisms thought to underlie learning and memory. Exactly how these abnormal processes arise is incompletely understood, but evidence suggests that dysregulation of intracellular Ca levels is involved in alterations of neuronal excitability, synaptic remodeling, and neurodegeneration in AD. Our lab has focused on the potential involvement of voltage-gated potassium channels (VGKCs) in these processes, particularly Kv1.
View Article and Find Full Text PDFBiomater Sci
January 2025
Department of Periodontology, College of Dentistry and Institute of Oral Bioscience, Jeonbuk National University, Jeonju, Republic of Korea.
Infected alveolar bone defects pose challenging clinical issues due to disrupted intrinsic healing mechanisms. Thus, the employment of advanced biomaterials enabling the modulation of several aspects of bone regeneration is necessary. This study investigated the effect of multi-functional nanoparticles on anti-inflammatory/osteoconductive characteristics and bone repair in the context of inflamed bone abnormalities.
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