Tumor necrosis factor-alpha potentiates intraneuronal Ca2+ signaling via regulation of the inositol 1,4,5-trisphosphate receptor.
Inflammatory events have long been implicated in initiating and/or propagating the pathophysiology associated with a number of neurological diseases. In addition, defects in Ca2+-handling processes, which shape membrane potential, influence gene transcription, and affect neuronal spiking patterns, have also been implicated in disease progression and cognitive decline. The mechanisms underlying the purported interplay that exists between neuroinflammation and Ca2+ homeostasis have yet to be defined. Herein, we describe a novel neuron-intrinsic pathway in which the expression of the type-1 inositol 1,4,5-trisphosphate receptor is regulated by the potent pro-inflammatory cytokine tumor necrosis factor-alpha. Exposure of primary murine neurons to tumor necrosis factor-alpha resulted in significant enhancement of Ca2+ signals downstream of muscarinic and purinergic stimulation. An increase in type-1 inositol 1,4,5-trisphosphate receptor mRNA and protein steady-state levels following cytokine exposure positively correlated with this alteration in Ca2+ homeostasis. Modulation of Ca2+ responses arising from this receptor subtype and its downstream effectors may exact significant consequences on neuronal function and could underlie the compromise in neuronal activity observed in the setting of chronic neuroinflammation, such as that associated with Parkinson disease and Alzheimer disease.
Center for Neural Development and Disease, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York 14642, USA.
Keigan M
KM
Park
David I
DI
Yule
William J
WJ
Bowers
D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D002460:Cell Line; D006224:Cricetinae; D005786:Gene Expression Regulation / Q000187:drug effects; D006706:Homeostasis / Q000187:drug effects; D007249:Inflammation / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000096:biosynthesis*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D010300:Parkinson Disease / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism* / Q000494:pharmacology
D016229:Amyloid beta-Peptides; D053496:Inositol 1,4,5-Trisphosphate Receptors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D002118:Calcium