Propofol Attenuates Hypoxia-Induced Inflammation in BV2 Microglia by Inhibiting Oxidative Stress and NF-κB/Hif-1α Signaling.

Hypoxia-induced neuroinflammation typically causes neurological damage and can occur during stroke, neonatal hypoxic-ischemic encephalopathy, and other diseases. Propofol is widely used as an intravenous anesthetic. Studies have shown that propofol has antineuroinflammatory effect. However, the underlying mechanism remains to be fully elucidated. Thus, we aimed to investigate the beneficial effects of propofol against hypoxia-induced neuroinflammation and elucidated its potential cellular and biochemical mechanisms of action. In this study, we chose cobalt chloride (CoCl2) to establish a hypoxic model. We found that propofol decreased hypoxia-induced proinflammatory cytokines (TNFα, IL-1ß, and IL-6) in BV2 microglia, significantly suppressed the excessive production of reactive oxygen species, and increased the total antioxidant capacity and superoxide dismutase activity. Furthermore, propofol attenuated the hypoxia-induced decrease in mitochondrial membrane potential andy 2 strongly inhibited protein expression of nuclear factor-kappa B (NF-κB) subunit p65 and hypoxia inducible factor-1α (Hif-1α) in hypoxic BV2 cells. To investigate the role of NF-κB p65, specific small interfering RNA (siRNA) against NF-κB p65 were transfected into BV2 cells, followed by exposure to hypoxia for 24 h. Hypoxia-induced Hif-1α production was downregulated after NF-κB p65 silencing. Further, propofol suppressed Hif-1α expression by inhibiting the upregulation of NF-κB p65 after exposure to hypoxia in BV2 microglia. In summary, propofol attenuates hypoxia-induced neuroinflammation, at least in part by inhibiting oxidative stress and NF-κB/Hif-1α signaling.

Intestinal Flora Dysbiosis Aggravates Cognitive Dysfunction Associated With Neuroinflammation in Heart Failure.

BACKGROUND: Cognitive dysfunction after heart failure (HF) is characterized by neuroinflammation, which plays an important role in the occurrence and development of cognitive dysfunction. Recent studies have shown that an intestinal flora imbalance may also trigger neuroinflammation in Alzheimer's disease. The present study was designed to reveal that intestinal flora dysbiosis caused by HF aggravates neuroinflammation-associated cognitive impairment. METHODS AND RESULTS: Adult male Sprague-Dawley rats were fed daily for 2 weeks with probiotics or placebo until the day of surgery. HF was then triggered by 8 weeks of sustained coronary artery occlusion. 16S rDNA sequencing was used to confirm intestinal flora dysbiosis after HF and demonstrate that the changes paralleled intestinal pathology scores. The permeability of the blood-brain barrier was increased after HF, and such an increase in permeability may increase the levels of inflammatory cytokines caused by intestinal flora disorders. The changes in the intestinal flora caused by probiotics significantly reduced the level of neuroinflammation. In addition, probiotic administration considerably improved the impaired spatial memory in HF rats. CONCLUSIONS: We conclude that intestinal flora dysbiosis plays a potential role in aggravating the impaired cognition associated with neuroinflammation and that these effects may be attenuated by probiotics.

Comparison of invasive blood pressure measurements from the caudal ventral artery and the femoral artery in male adult SD and Wistar rats.

BACKGROUND AND PURPOSE: Studies have suggested that the caudal ventral artery is a potential site for continuous arterial blood pressure monitoring in rats. However, the agreement of mean arterial pressure values between the femoral artery and the caudal ventral artery has not been investigated. This study was performed to identify whether the caudal ventral artery could be safely used for continuous blood pressure monitoring as an alternative site to the femoral artery. METHODS: Rats were randomized into four groups: Sprague Dawley rats under normothermia; Wistar rats under normothermia; Sprague Dawley rats under hypothermia; Wistar rats under hypothermia. Each rat underwent simultaneous monitoring of blood pressure using femoral artery and caudal ventral artery catheterization during a stable hemodynamic state and three periods of acute severe hemodynamic changes. The effects of rat strain, rectal temperature, experimental time course and hemodynamic factors on pressure gradients, the concordance of mean arterial pressure values between the femoral artery and the caudal ventral artery, and the rates of distal ischemia after surgery were determined. RESULTS: There was a significant difference in the rate of distal ischemia between femoral and caudal ventral arteries after catheterization (25% vs 5%, P<0.05). The overall mean gradient and the mean gradient under a steady hemodynamic state were 4.9±3.7 mm Hg and 5.5±2.5 mm Hg, respectively. The limits of agreement (bias±1.96 SD) were (-2.5 mm Hg, 12.3 mm Hg) and (-0.5 mm Hg, 10.5 mm Hg), respectively. Although the concordance decreased during the first 30 sec of each period of severe hemodynamic changes, the degree of agreement was acceptable regardless of the effects of rat strain and rectal temperature. CONCLUSIONS: Based on the degree of agreement and the safety of catheterization, the caudal ventral artery may be a preferred site for continuous arterial blood pressure monitoring without acute severe hemodynamic changes.