Frégeau MO, Carrier M, Guillemette G. Mechanism of dopamine D2 receptor-induced Ca(2+) release in PC-12 cells.
Cell Signal 2013;
25:2871-7. [PMID:
24055909 DOI:
10.1016/j.cellsig.2013.08.021]
[Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 08/23/2013] [Indexed: 01/06/2023]
Abstract
Intracellular Ca(2+) levels are tightly regulated in the neuronal system. The loss of Ca(2+) homeostasis is associated with many neurological diseases and neuropsychiatric disorders such as Parkinson's, Alzheimer's, and schizophrenia. We investigated the mechanisms involved in intracellular Ca(2+) signaling in PC-12 cells. The stimulation of NGF-differentiated PC-12 cells with 3μM ATP caused an early Ca(2+) release followed by a delayed Ca(2+) release. The delayed Ca(2+) release was dependent on prior ATP priming and on dopamine secretion by PC-12 cells. Delayed Ca(2+) release was abolished in the presence of spiperone, suggesting that it is due to the activation of D2 dopamine receptors (D2R) by dopamine secreted by PC-12 cells. This was shown to be independent of PKA activation but dependent on PLC activity. An endocytosis step was required for inducing the delayed Ca(2+) release. Given the importance of calcyon in clathrin-mediated endocytosis, we verified the role of this protein in the delayed Ca(2+) release phenomenon. siRNA targeting of calcyon blocked the delayed Ca(2+) release, decreased ATP-evoked IP3R-mediated Ca(2+) release, and impaired subsequent Ca(2+) oscillations. Our results suggested that calcyon is involved in an unknown mechanism that causes a delayed IP3R-mediated Ca(2+) release in PC-12 cells. In schizophrenia, Ca(2+) dysregulation may depend on the upregulation of calcyon, which maintains elevated Ca(2+) levels as well as dopamine signaling.
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