Endothelial SIRT6 blunts stroke size and neurological deficit by preserving blood-brain barrier integrity: a translational study.
Eur Heart J
; 41(16): 1575-1587, 2020 04 21.
Article
in En
| MEDLINE
| ID: mdl-31603194
ABSTRACT
AIMS:
Aging is an established risk factor for stroke; genes regulating longevity are implicated in the pathogenesis of ischaemic stroke where to date, therapeutic options remain limited. The blood-brain barrier (BBB) is crucially involved in ischaemia/reperfusion (I/R) brain injury thus representing an attractive target for developing novel therapeutic agents. Given the role of endothelial cells in the BBB, we hypothesized that the endothelial-specific expression of the recently described longevity gene SIRT6 may exhibit protective properties in stroke. METHODS ANDRESULTS:
SIRT6 endothelial expression was reduced following stroke. Endothelial-specific Sirt6 knockout (eSirt6-/-) mice, as well as animals in which Sirt6 overexpression was post-ischaemically induced, underwent transient middle cerebral artery occlusion (tMCAO). eSirt6-/- animals displayed increased infarct volumes, mortality, and neurological deficit after tMCAO, as compared to control littermates. Conversely, post-ischaemic Sirt6 overexpression decreased infarct size and neurological deficit. Analysis of ischaemic brain sections revealed increased BBB damage and endothelial expression of cleaved caspase-3 in eSIRT6-/- mice as compared to controls. In primary human brain microvascular endothelial cells (HBMVECs), hypoxia/reoxygenation (H/R) reduced SIRT6 expression and SIRT6 silencing impaired the barrier function (transendothelial resistance) similar to what was observed in mice exposed to I/R. Further, SIRT6-silenced HBMVECs exposed to H/R showed reduced viability, increased cleaved caspase-3 expression and reduced activation of the survival pathway Akt. In ischaemic stroke patients, SIRT6 expression was higher in those with short-term neurological improvement as assessed by NIHSS scale and correlated with stroke outcome.CONCLUSION:
Endothelial SIRT6 exerts a protective role in ischaemic stroke by blunting I/R-mediated BBB damage and thus, it may represent an interesting novel therapeutic target to be explored in future clinical investigation.Key words
Full text:
1
Database:
MEDLINE
Main subject:
Brain Ischemia
/
Stroke
/
Sirtuins
Type of study:
Risk_factors_studies
Limits:
Animals
/
Humans
Language:
En
Year:
2020
Type:
Article