Ischemic Post-Conditioning Induces Post-Stroke Neuroprotection via Hsp70-Mediated Proteasome Inhibition and Facilitates Neural Progenitor Cell Transplantation


Doeppner T. R., Doehring M., Kaltwasser B., Majid A., Lin F., Bähr M., ...More

Molecular Neurobiology, vol.54, no.8, pp.6061-6073, 2017 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 54 Issue: 8
  • Publication Date: 2017
  • Doi Number: 10.1007/s12035-016-0137-3
  • Journal Name: Molecular Neurobiology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.6061-6073
  • Keywords: Cerebral ischemia, Stroke, Neural progenitor cells, Post-conditioning, Preconditioning, Transplantation, Hsp70, Proteasome
  • Istanbul Medipol University Affiliated: Yes

Abstract

In view of the failure of pharmacological therapies, alternative strategies promoting post-stroke brain repair are needed. Post-conditioning is a potentially promising therapeutic strategy, which induces acute neuroprotection against ischemic injury. To elucidate longer lasting actions of ischemic post-conditioning, mice were exposed to a 60-min stroke and post-conditioning by an additional 10-min stroke that was induced 10 min after reperfusion onset. Animals were sacrificed 24 h or 28 days post-stroke. Post-conditioning reduced infarct volume and neurological deficits 24 h post-stroke, enhancing blood-brain barrier integrity, reducing brain leukocyte infiltration, and reducing oxidative stress. On the molecular level, post-conditioning yielded increased Hsp70 expression, whereas nuclear factor (NF)-κB and proteasome activities were decreased. Reduced infarct volume and proteasome inhibition were reversed by Hsp70 knockdown, suggesting a critical role of the Hsp70 proteasome pathway in ischemic post-conditioning. The survival-promoting effects of ischemic post-conditioning, however, were not sustainable as neuroprotection and neurological recovery were lost 28 days post-stroke. Although angioneurogenesis was not increased by post-conditioning, the favorable extracellular milieu facilitated intracerebral transplantation of neural progenitor cells 6 h post-stroke, resulting in persisted neuroprotection and neurological recovery. Thus, post-conditioning might support brain repair processes, but in view of its transient, neuroprotection is unlikely useful as stroke therapy in its current form.