Research Paper Volume 13, Issue 3 pp 3405—3427

PTP1B inhibitor alleviates deleterious microglial activation and neuronal injury after ischemic stroke by modulating the ER stress-autophagy axis via PERK signaling in microglia

Yu Zhu1, , Jianbo Yu1, , Jiangbiao Gong1, , Jie Shen1, , Di Ye1, , Dexin Cheng1, , Zhikai Xie1, , Jianping Zeng1, , Kangli Xu2, , Jian Shen1, , Hengjun Zhou1, , Yuxiang Weng1, , Jianwei Pan1, , Renya Zhan1, ,

  • 1 Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
  • 2 Emergency Department Trauma Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China

Received: February 21, 2020       Accepted: November 6, 2020       Published: January 20, 2021
How to Cite

Copyright: © 2021 Zhu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Cerebral ischemia/reperfusion (IR) after ischemic stroke causes deleterious microglial activation. Protein tyrosine phosphatase 1B (PTP1B) exacerbates neuroinflammation, yet the effect of the inhibition on microglial activation and cerebral IR injury is unknown. A cerebral IR rat model was induced by middle cerebral artery occlusion (MCAO) and reperfusion. The PTP1B inhibitor, sc-222227, was administered intracerebroventricularly. Neurologic deficits, infarct volume, and brain water content were examined. An in vitro oxygen glucose deprivation/reoxygenation (OGD/R) model was established in primary microglia and BV-2 cells. Microglial activation/polarization, endoplasmic reticulum (ER) stress, autophagy, and apoptosis were detected using western blot, immunohistology, ELISA, and real-time PCR. Protein interaction was assessed by a proximity ligation assay. The results showed a significant increase in microglial PTP1B expression after IR injury. Sc-222227 attenuated IR-induced microglial activation, ER stress, and autophagy and promoted M2 polarization. Upon OGD/R, sc-222227 mitigated microglial activation by inhibiting ER stress-dependent autophagy, the effect of which was abolished by PERK activation, and PERK inhibition attenuated microglial activation. The PTP1B-phosphorylated PERK protein interaction was significantly increased after OGD/R, but decreased upon sc-222227 treatment. Finally, sc-222227 mitigated neuronal damage and neurologic deficits after IR injury. Treatment targeting microglial PTP1B might be a potential therapeutic strategy for ischemic stroke treatment.


PTP1B: Protein tyrosine phosphatase 1B (PTP1B); PTP1Bsc: PTP1B inhibitor sc-222227; ER: endoplasmic reticulum; IR: ischemia/reperfusion; MCAO: middle cerebral artery occlusion; OGD/R: oxygen glucose deprivation/reoxygenation; Bip: heavy chain binding protein; ELISA: enzyme-linked immunosorbent assay; PCR: polymerase chain reaction; PERK: protein kinase R-like endoplasmic reticulum kinase; IRE1: inositol requiring enzyme-1; ATF6: activating transcription factor 6; NeuN: neuronal nuclear antigen; Iba-1: ionized calcium binding adapter molecule 1; LC3: microtubule-associated protein 1-light chain 3; GFAP: glial fibrillary acidic protein; GAPDH: Glyceraldehyde-3-Phosphate Dehydrogenase; TNF-α: Tumor Necrosis Factor-alpha; CCL2: Chemokine (C-C Motif) Ligand 2; IL-1β: Interleukin-1beta; IL-6: Interleukin-6; PLA: proximity ligation assays; IOD: integrated optical density; 4-PBA: 4-phenylbutylamine; 3-MA: N(3)-methyladenine; TUNEL: Terminal deoxynucleotidyl transferase dUTP nick end labeling.