Sodium/Hydrogen Exchanger 1 Participates in Early Brain Injury after Subarachnoid Hemorrhage both in vivo and in vitro via Promoting Neuronal Apoptosis.

Abstract

Sodium/hydrogen exchanger 1 (NHE1) plays an essential role in maintaining intracellular pH (pHi) homeostasis in the central nervous system (CNS) under physiological conditions, and it is also associated with neuronal death and intracellular Na+ and Ca2+ overload induced by cerebral ischemia. However, its roles and underlying mechanisms in early brain injury (EBI) induced by subarachnoid hemorrhage (SAH) have not been fully explored. In this research, a SAH model in adult male rat was established through injecting autologous arterial blood into prechiasmatic cistern. Meanwhile, primary cultured cortical neurons of rat treated with 5 μM oxygen hemoglobin (OxyHb) for 24 h were applied to mimic SAH in vitro. We find that the protein levels of NHE1 are significantly increased in brain tissues of rats after SAH. Downregulation of NHE1 by HOE642 (a specific chemical inhibitor of NHE1) and genetic-knockdown can effectively alleviate behavioral and cognitive dysfunction, brain edema, blood-brain barrier (BBB) injury, inflammatory reactions, oxidative stress, neurondegeneration, and neuronal apoptosis, all of which are involved in EBI following SAH. However, upregulation of NHE1 by genetic-overexpression can produce opposite effects. Additionally, inhibiting NHE1 significantly attenuates OxyHb-induced neuronal apoptosis in vitro and reduces interaction of NHE1 and CHP1 both in vivo and in vitro. Collectively, we can conclude that NHE1 participates in EBI induced by SAH through mediating inflammation, oxidative stress, behavioral and cognitive dysfunction, BBB injury, brain edema, and promoting neuronal degeneration and apoptosis.

• Authors: Huangcheng Song, Shuai Yuan, Zhuwei Zhang, Juyi Zhang, Peng Zhang, Jie Cao, Haiying Li, Xiang Li, Haitao Shen, Zhong Wang, Gang Chen
• Journal: Cell transplantation (Cell Transplant) Vol. 28 Issue 8 Pg. 985-1001 (08 2019) ISSN: 1555-3892 [Electronic] United States
• PMID: 30838887 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Calcium-Binding Proteins
• Lipoproteins
• Oxyhemoglobins
• Sodium-Hydrogen Exchanger 1
• calcium binding protein p22, rat

Topics

• Animals
• Apoptosis
• Brain (metabolism, pathology)
• Brain Injuries (etiology, metabolism)
• Calcium-Binding Proteins (metabolism)
• Lipoproteins (metabolism)
• Male
• Nerve Degeneration (complications, pathology)
• Neurons (metabolism, pathology)
• Oxyhemoglobins (metabolism)
• Rats, Sprague-Dawley
• Sodium-Hydrogen Exchanger 1 (metabolism)
• Subarachnoid Hemorrhage (complications)