title: Protective HSP70 Induction by Z-Ligustilide against Oxygen-Glucose Deprivation Injury via Activation of the MAPK Pathway but Not of HSF1.
abstract: Heat-shock protein 70 (HSP70) is known to function as a protective molecular chaperone that is massively induced in response to misfolded proteins following cerebral ischemia. The objective of this study was to characterize HSP70 induction by Z-ligustilide and explore its potential role in protection against cerebral ischemia-reperfusion injury. Our results demonstrated that the intranasal administration of Z-ligustilide reduced infarct volume and improved neurological function in a rat stroke model. Meanwhile, Z-ligustilide enhanced the cell viability of PC12 cells insulted by oxygen-glucose deprivation-reoxygenation (OGD-Reoxy) and decreased apoptotic and necrotic cell death. Importantly, Z-ligustilide induced HSP70 expression both in vitro and in vivo. Although heat-shock factor 1 (HSF1) nuclear translocation was promoted by Z-ligustilide, HSP70-based heat-shock element (HSE)-binding luciferase activity was not activated, and HSP70 expression responsive to Z-ligustilide was not attenuated by HSE decoy oligonucleotides. However, Z-ligustilide significantly activated the phosphorylation of mitogen-activated protein kinases (MAPKs). Further inhibition of MAPK activity by specific inhibitors attenuated HSP70 induction by Z-ligustilide. Meanwhile, downregulation of HSP70 using KNK437, an HSP70 synthesis inhibitor, or small hairpin RNA (shRNA) significantly attenuated the protection of Z-ligustilide against OGD-Reoxy-induced injury. Moreover, the application of specific inhibitors of MAPKs also achieved similar results. Finally, Z-ligustilide alleviated the accumulation of ubiquitinated proteins induced by OGD-Reoxy, which was inhibited by HSP70-shRNA. Taken together, our results demonstrated that Z-ligustilide may induce protective HSP70 expression via the activation of the MAPK pathway, but not canonical HSF1 transcription. HSP70 plays a key role in the protection of Z-ligustilide against OGD-Reoxy-induced injury.
authors.affiliation: Department of Pharmaceutical Sciences, Southwest University.
authors.forename: Jie
authors.initials: J
authors.lastname: Yu
authors.forename: Zhuyun
authors.initials: Z
authors.lastname: Jiang
authors.forename: Ling
authors.initials: L
authors.lastname: Ning
authors.forename: Zhilong
authors.initials: Z
authors.lastname: Zhao
authors.forename: Na
authors.initials: N
authors.lastname: Yang
authors.forename: Lu
authors.initials: L
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Ma
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Ya
authors.initials: Y
authors.lastname: Fu
authors.forename: Huifeng
authors.initials: H
authors.lastname: Zhu
authors.forename: Hongyi
authors.initials: H
authors.lastname: Qi
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001559:Benzhydryl Compounds / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D005947:Glucose; D057809:HEK293 Cells; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism* / Q000473:pathology; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010100:Oxygen; D016716:PC12 Cells; D011760:Pyrrolidinones / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology
chemical_list: D001559:Benzhydryl Compounds; D018840:HSP70 Heat-Shock Proteins; C410027:KNK 437; D018696:Neuroprotective Agents; D011760:Pyrrolidinones; D034741:RNA, Small Interfering; C027820:ligustilide; D005947:Glucose; D015107:4-Butyrolactone; D010100:Oxygen