Abstract
Abstract
P2X4 is an ATP-gated purinergic receptor upregulated in spinal microglia after peripheral nerve injury, where it plays a key role in neuropathic pain. Yet, the molecular mechanisms controlling P2X4 expression remain incompletely understood.
To address this question, we examined P2X4 mRNA expression and translation in spinal microglia following nerve injury. While total P2X4 mRNA levels remained unchanged, ribosome-associated P2X4 mRNA increased, revealing a previously unrecognized level of translational regulation. We therefore investigated whether the RNA-binding protein ZFP36 (tristetraprolin), a well-established regulator of inflammatory mRNAs, controls P2X4 expression. Our results demonstrate that the P2X4 3′UTR strongly repressed reporter and protein expression and that ZFP36 emerged as a negative regulator of P2X4 mRNA. This regulation involved phosphorylation-dependent signaling through p38 MAPK and 14-3-3. Moreover, ZFP36 knockdown increased P2X4 protein expression, while manipulation of ZFP36 phosphorylation altered P2X4-dependent ATP-evoked calcium responses.
Together, these findings identify ZFP36 as a previously unrecognized post-transcriptional regulator of P2X4, extending its role beyond inflammatory mediators to a functional purinergic receptor. They reveal post-transcriptional control of receptor availability as a novel regulatory layer linking myeloid cell state to purinergic responsiveness and provide a new framework for understanding microglial P2X4 regulation in neuropathic pain.