Remote ischemic postconditioning: harnessing endogenous protection in a murine model of vascular cognitive impairment

Transl Stroke Res. 2015 Feb;6(1):69-77. doi: 10.1007/s12975-014-0374-6. Epub 2014 Oct 29.

Abstract

We previously reported that remote limb ischemic conditioning (RLIC; PERconditioning) during acute stroke confers neuroprotection, possibly due to increased cerebral blood flow (CBF). Vascular cognitive impairment (VCI) is a growing threat to public health without any known treatment. The bilateral common carotid artery stenosis (BCAS) mouse model is regarded as the most valid model for VCI. We hypothesized that RLIC (postconditioning; RIPostC) will augment CBF during chronic cerebral hypoperfusion (CCH) and prevent cognitive impairment in the BCAS model. BCAS using customized microcoil was performed in C57/B6 male mice to establish CCH. A week after the BCAS surgery, mice were treated with RIPostC-therapy once daily for 2 weeks. CBF was measured with laser speckle contrast imager at different time points. Cognitive testing was performed at 4-week post-BCAS, and brain tissue was harvested for biochemistry. BCAS led to chronic hypoperfusion resulting into impaired cognitive function as tested by novel object recognition (NOR). Histological examinations revealed that BCAS triggered inflammatory responses and caused frequent vacuolization and cell death. BCAS also increased the generation and accumulation of amyloid beta protein (Aβ), resulting into the loss of white matter (WM) and myelin basic protein (MBP). RIPostC-therapy showed both acute increase as well as sustained improvement in CBF even after the cessation of therapy for a week. RIPostC improved cognitive function, inhibited inflammatory responses, prevented the cell death, reduced the generation and accumulation of Aβ, and protected WM integrity. RIPostC is effective in the BCAS model and could be an attractive low-cost conventional therapy for aged individuals with VCI. The mechanisms by which RIPostC improves CBF and attenuates tissue damage need to be investigated in the future.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amyloid beta-Peptides / metabolism
  • Animals
  • Brain Ischemia / complications
  • Brain Ischemia / psychology
  • Brain Ischemia / therapy*
  • Carotid Stenosis / complications
  • Carotid Stenosis / psychology
  • Carotid Stenosis / therapy*
  • Cell Death
  • Cerebral Cortex / blood supply*
  • Cerebral Cortex / metabolism
  • Cerebral Cortex / pathology
  • Dementia, Vascular / etiology
  • Dementia, Vascular / therapy*
  • Disease Models, Animal
  • Encephalitis / metabolism
  • Ischemic Postconditioning*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Myelin Sheath / pathology
  • Recognition, Psychology / physiology
  • White Matter / pathology

Substances

  • Amyloid beta-Peptides