Transient receptor potential channel 1/4 reduces subarachnoid hemorrhage-induced early brain injury in rats via calcineurin-mediated NMDAR and NFAT dephosphorylation

Sci Rep. 2016 Sep 19:6:33577. doi: 10.1038/srep33577.

Abstract

Transient receptor potential channel 1/4 (TRPC1/4) are considered to be related to subarachnoid hemorrhage (SAH)-induced cerebral vasospasm. In this study, a SAH rat model was employed to study the roles of TRPC1/4 in the early brain injury (EBI) after SAH. Primary cultured hippocampal neurons were exposed to oxyhemoglobin to mimic SAH in vitro. The protein levels of TRPC1/4 increased and peaked at 5 days after SAH in rats. Inhibition of TRPC1/4 by SKF96365 aggravated SAH-induced EBI, such as cortical cell death (by TUNEL staining) and degenerating (by FJB staining). In addition, TRPC1/4 overexpression could increase calcineurin activity, while increased calcineurin activity could promote the dephosphorylation of N-methyl-D-aspartate receptor (NMDAR). Calcineurin antagonist FK506 could weaken the neuroprotection and the dephosphorylation of NMDAR induced by TRPC1/4 overexpression. Contrarily, calcineurin agonist chlorogenic acid inhibited SAH-induced EBI, even when siRNA intervention of TRPC1/4 was performed. Moreover, calcineurin also could lead to the nuclear transfer of nuclear factor of activated T cells (NFAT), which is a transcription factor promoting the expressions of TRPC1/4. TRPC1/4 could inhibit SAH-induced EBI by supressing the phosphorylation of NMDAR via calcineurin. TRPC1/4-induced calcineurin activation also could promote the nuclear transfer of NFAT, suggesting a positive feedback regulation of TRPC1/4 expressions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus
  • Animals
  • Biomarkers
  • Brain Hemorrhage, Traumatic / drug therapy
  • Brain Hemorrhage, Traumatic / metabolism*
  • Brain Hemorrhage, Traumatic / pathology
  • Calcineurin / metabolism*
  • Cell Death / drug effects
  • Models, Biological
  • NFATC Transcription Factors / metabolism*
  • Neurons / drug effects
  • Neurons / metabolism
  • Oxyhemoglobins / metabolism
  • Oxyhemoglobins / pharmacology
  • Phosphorylation
  • Rats
  • Receptors, N-Methyl-D-Aspartate / metabolism*
  • Subarachnoid Hemorrhage
  • TRPC Cation Channels / antagonists & inhibitors
  • TRPC Cation Channels / metabolism*

Substances

  • Biomarkers
  • NFATC Transcription Factors
  • Oxyhemoglobins
  • Receptors, N-Methyl-D-Aspartate
  • TRPC Cation Channels
  • TRPC4 ion channel
  • transient receptor potential cation channel, subfamily C, member 1
  • Calcineurin