Hypertonic saline regulates microglial M2 polarization via miR-200b/KLF4 in cerebral edema treatment

Highlights: • Hypertonic saline (HS) alleviates cerebral edema via regulating neuroinflammation. • miR-200b/KLF4 regulates microglial M2 polarization during HS treatment. • KLF4 directly binds to Arg1 promoter and induces its transcription. • Modulation of KLF4 in vivo affects HS treatment of cerebral edema. Hypertonic saline (HS) has been used clinically for treatment of cerebral edema for decades. Previously we have demonstrated that HS alleviates cerebral edema via regulating water/ion channel protein and attenuating neuroinflammation. However, whether HS treatment triggers microglia polarization and its regulatory mechanism during this process is unclear.