Altered PLCβ/IP₃/Ca²⁺ Signaling Pathway Activated by GPRCs in Olfactory Neuronal Precursor Cells Derived from...

Background: Schizophrenia (SZ) is a multifactorial chronic psychiatric disorder with a worldwide prevalence of 1%. Altered expression of PLCβ occurs in SZ patients, suggesting alterations in the PLCβ/IP₃/Ca²⁺ signaling pathway. This cascade regulates critical cellular processes in all cell types, including the neuronal lineage; however, there is scarce evidence regarding the functionality of this transduction signaling in neuronal cells derived from SZ patients. Objective: We evaluated the functionality of the PLCβ/IP₃/Ca²⁺ pathway in olfactory neuronal precursor cells (hONPCs) obtained from SZ patients. Methods: Cryopreserved hONPCs isolated from SZ patients and healthy subjects (HS) were thawed. The cellular types in subcultures were corroborated by immunodetection of the multipotency and lineage markers SOX-2, Musashi-1, nestin, and β-III tubulin. The PLCβ/IP₃/Ca²⁺ pathway was activated by GPCR (G_q) ligands (ATP, UTP, serotonin, and epinephrine). In addition, PLCβ and IP₃R were directly stimulated by perfusing cells with the activators m-3M3FBS and ADA, respectively. Cytosolic Ca²⁺ was measured by microfluorometry and by Ca²⁺ imaging. The amount and subcellular distribution of the PLCβ1 and PLCβ3 isoforms were evaluated by confocal immunofluorescence. IP₃ concentration was measured by ELISA. Results: The results show that the increase of cytosolic Ca²⁺ triggered by GPCR ligands or directly through either PLCβ or IP₃R activation was significantly lower in SZ-derived hONPCs, regarding HS-derived cells. Moreover, the relative amount of the PLCβ1 and PLCβ3 isoforms and IP₃ production stimulated with m-3M3FBS were reduced in SZ-derived cells. Conclusions: Our results suggest an overall functional impairment in the PLCβ/IP₃/Ca²⁺ signaling pathway in SZ-derived hONPCs.