P2X7 Participates in Intracerebral Hemorrhage-Induced Secondary Brain Injury in Rats via MAPKs Signaling Pathways

Abstract

This study aimed to study the role of P2X7 in intracerebral hemorrhage (ICH)-induced secondary brain injury (SBI) and the underlying mechanisms. An autologous blood injection was used to induce ICH model in Sprague-Dawley rats, and cultured primary rat cortical neurons were exposed to oxyhemoglobin to mimic ICH in vitro. siRNA interference and over-expression of P2X7, agonists and antagonists of P2X7, p38 MAPK and ERK were exploited. The protein levels were assessed using Western blotting and immunofluorescence staining. Terminal deoxynucleotidyl transferase dUTP nick end labeling staining and Fluoro-Jade B were conducted to detect apoptotic and degenerating neurons. The protein levels of P2X7, phosphorylated p38, ERK, active caspase-3 and NF-κB were significantly increased by ICH, which could be further increased by BzATP (P2X7 agonist) and reduced by BBG (P2X7 antagonist). And BzATP demonstrated a significant increase in cell death ratio and brain water content, while BBG led to a reverse results. In addition, Over- P2X7 increased the levels of P2X7, phosphorylated p38, ERK, active caspase-3 and NF-κB, and aggravated cell apoptosis, while si P2X7 resulted in opposite effects. Finally, the protein levels of phosphorylated P38 and active caspase 3 were decreased by BzATP plus Hydrochloride (p38 MAPK antagonist) and increased vy BBG plus Asiatic acid (p38 MAPK agonist), while the protein levels of phosphorylated ERK and NF-κB were decreased with BzATP plus Nimbolide (ERK antagonist) and increased with BBG plus Saikosaponin C (ERK agonist). This study demonstrates that inhibition of P2X7 could prevent ICH-induced SBI via MAPKs signaling pathway.

Pharmacological Properties, Molecular Mechanisms, and Pharmaceutical Development of Asiatic Acid: A Pentacyclic Triterpenoid of Therapeutic Promise

“…The findings suggest that the combination of AA with t-PA is superior in improving neurological outcome and reducing infarct volume. In a recent study, AA was found to protect against intracerebral hemorrhage-induced secondary brain injury by mediating MAPKs signaling pathway as AA acts as a p38 MAPK agonist and may work in synergy with a P2X7 antagonist, BBG (Wen et al, 2017 ). Taken together, the results demonstrated many neuroprotective activities of AA to the ischemic brain.…”

Assessing the Pharmacological and Therapeutic Efficacy of Traditional Chinese Medicine Liangxue Tongyu Prescription for Intracerebral Hemorrhagic Stroke in Neurological Disease Models

“…As shown in Figure 3 , abundant compounds in LP regulated signaling pathways by adjusting and controlling these key pathway targets on ICH. Some important common pathways such as TGF-β/smad signaling, Mitogen-Activated Protein Kinase Cascades, Apoptosis Cascades,PI3K/AKT signaling, Toll-like Receptors Pathway and NF-κB Signaling were included in the course of ICH process ( Liu et al, 2016 ; Taylor et al, 2017 ; Wen et al, 2017 ), which covered apoptosis, proliferation, differentiation, inflammatory and immunoregulation and many other important biological processes. Meanwhile, a total of 72 compounds from eight ingredients of LP affected the prothrombotic and proinflammatory signaling pathways and regulated the AKT, MAPK, and BCL-2 pathways.…”

Adenosine Triphosphate Accumulated Following Cerebral Ischemia Induces Neutrophil Extracellular Trap Formation

“…In evaluating the underlying mechanism, we found PAD upregulation to play a critical role in P2X7R-mediated induction of NETosis, since PAD4 and CitH3 levels were further enhanced by BzATP administration in MCAO animals. Detrimental effects of P2X7R were demonstrated in animal models of cerebral ischemia [ 32 ] and intracerebral hemorrhage [ 33 , 34 , 35 ], with proposed involvement of blood brain barrier disruption [ 33 ], NLRP3 inflammasome-mediated aggravation of inflammation [ 34 ], and the induction of secondary brain injury [ 35 ] as underlying mechanisms. The current study adds a novel putative mechanism; NETosis induction.…”