Age, sex, and setting in the etiology of stroke study (ASSESS): Study design and protocol

Dexmedetomidine Post-Conditioning Alleviates Cerebral Ischemia-Reperfusion Injury in Rats by Inhibiting High Mobility Group Protein B1 Group (HMGB1)/Toll-Like Receptor 4 (TLR4)/Nuclear Factor kappa B (NF-κB) Signaling Pathway

BACKGROUND Cerebral ischemia-reperfusion injury is a pivotal cause of deaths due to cerebrovascular accident. Increased research efforts are needed to reveal the mechanism underlying its aggravation or alleviation. In this study, the effects of dexmedetomidine post-conditioning on the HMGB1/TLR4/NF-kappaB signaling pathway in cerebral ischemia-reperfusion rats was explored. MATERIAL AND METHODS Ninety rats were randomly divided into 5 groups - a sham group (Sham), a model group (I/R), a dexmedetomidine post-conditioning group (Dex), a recombinant high mobility group protein B1 group (rHMGB1), and a recombinant HMGB1+dexmedetomidine post-conditioning group (rHMGB1+Dex) - with 18 rats in each group. Longa grading, wet-dry weighing, TTC staining, HE staining, and immunohistochemical staining were used to assess brain damage. ELISA, RT-PCR, and Western blot analyses were performed to assess expression of IL-1ß, TNF-alpha, IL-6, IL-8, HMGB1, TLR4, and NF-kappaB. RESULTS Compared with the I/R group, the neurological function score, brain water content, infarction area, and the number of COX-2- and IBA-1-positive cells in the Dex group were significantly lower, accompanied by downregulated expression of the HMGB1/TLR4/NF-kappaB pathway, alleviated inflammation, and oxidative stress injury in brain tissue. These trends were mostly reversed in the rHMGB1 group and rHMGB1+Dex group, but not in the Dex group. Furthermore, when compared to the Dex group, there were significant increases of H₂O₂, MDA, NO, IL-1ß, TNF-alpha, IL-6, IL-8, HMGB1, TLR4, and p-P65 in the rHMGB1 group and rHMGB1+Dex group, in which a significant decrease of T-AOC, SOD, and p-IkappaBalpha was also detected. CONCLUSIONS Dexmedetomidine post-conditioning can alleviate cerebral ischemia-reperfusion injury in rats by inhibiting the HMGB1/TLR4/NF-kappaB signaling pathway.

Ginkgetin attenuates cerebral ischemia-reperfusion induced autophagy and cell death via modulation of the NF-κB/p53 signaling pathway

Background: Cerebral ischemia–reperfusion (I/R) injury is the key to fatality in cerebrovascular accident, hence further endeavor is warranted to delineate the mechanism underlying its lethal aggravation procedure. In the present study, we aimed to elucidate the anti-autophagy and anti-apoptosis effects of ginkgetin via nuclear factor κB (NF-κB)/p53 pathway in cerebral I/R rats.

Methods: Rats were administrated 2-h occlusion of right middle cerebral artery before the 24-h reperfusion followed. There were three doses of ginkgetin (25, 50, 100 mg/kg) given intraperitoneally (i.p.) after the 2-h ischemia, and Pifithrin-α (PFT-α, p53 inhibitor), SN50 (NF-κB inhibitor) and 3-methyladenine (3-MA, autophagy inhibitor) was administered 20 min before the ischemia, respectively.

Results: The neurological deficits decreased significantly with the administration of ginkgetin. The concentrations of microtubule-associated protein 1 light chain 3-II and p53 were significantly decreased by PFT-α, 3-MA and ginkgetin. The concentrations of Beclin 1, damage-regulated autophagy modulator, cathepsin B and cathepsin D were significantly decreased due to the administration of PFT-α, ginkgetin and SN50. Furthermore, the concentrations of Bax and p53-upregulated modulator of apoptosis were significantly decreased with that of Bcl-2 being significantly increased by administration of SN50, PFT-α and ginkgetin.

Conclusion: Ginkgetin can alleviate cerebral ischemia/reperfusion induced autophagy and apoptosis by inhibiting the NF-κB/p53 signaling pathway.