BackgroundMicroglial activation and the subsequent inflammatory response in the central nervous system play important roles in secondary damage after traumatic brain injury (TBI). High-mobility group box 1 (HMGB1) protein, an important mediator in late inflammatory responses, interacts with transmembrane receptor for advanced glycation end products (RAGE) and toll-like receptors (TLRs) to activate downstream signaling pathways, such as the nuclear factor (NF)-κB signaling pathway, leading to a cascade amplification of inflammatory responses, which are related to neuronal damage after TBI. Omega-3 polyunsaturated fatty acid (ω-3 PUFA) is a commonly used clinical immunonutrient, which has antioxidative and anti-inflammatory effects. However, the effects of ω-3 PUFA on HMGB1 expression and HMGB1-mediated activation of the TLR4/NF-κB signaling pathway are not clear.MethodsThe Feeney DM TBI model was adopted to induce brain injury in rats. Modified neurological severity scores, brain water content, and Nissl staining were employed to determine the neuroprotective effects of ω-3 PUFA supplementation. Assessment of microglial activation in lesioned sites and protein markers for proinflammatory, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, interferon (IFN)-γ, and HMGB1 were used to evaluate neuroinflammatory responses and anti-inflammation effects of ω-3 PUFA supplementation. Immunofluorescent staining and western blot analysis were used to detect HMGB1 nuclear translocation, secretion, and HMGB1-mediated activation of the TLR4/NF-κB signaling pathway to evaluate the effects of ω-3 PUFA supplementation and gain further insight into the mechanisms underlying the development of the neuroinflammatory response after TBI.ResultsIt was found that ω-3 PUFA supplementation inhibited TBI-induced microglial activation and expression of inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ), reduced brain edema, decreased neuronal apoptosis, and improved neurological functions after TBI. We further demonstrated that ω-3 PUFA supplementation inhibited HMGB1 nuclear translocation and secretion and decreased expression of HMGB1 in neurons and microglia in the lesioned areas. Moreover, ω-3 PUFA supplementation inhibited microglial activation and the subsequent inflammatory response by regulating HMGB1 and the TLR4/NF-κB signaling pathway.ConclusionsThe results of this study suggest that microglial activation and the subsequent neuroinflammatory response as well as the related HMGB1/TLR4/NF-κB signaling pathway play essential roles in secondary injury after TBI. Furthermore, ω-3 PUFA supplementation inhibited TBI-induced microglial activation and the subsequent inflammatory response by regulating HMGB1 nuclear translocation and secretion and also HMGB1-mediated activation of the TLR4/NF-κB signaling pathway, leading to neuroprotective effects.

BACKGROUND HSK3486 (ciprofol) is a 2,6-disubstituted phenol derivative that acts like propofol as an agonist at the gamma-aminobutyric acid-A (GABA A ) receptor. OBJECTIVE To investigate the efficacy and safety of HSK3486 for general anaesthesia induction and maintenance. DESIGN A single-blinded, randomised, parallel-group, phase 3 trial. SETTING Involving 10 study centres, from November 24, 2020 to January 25, 2021. PATIENTS A total of 129 patients undergoing nonemergency, noncardiothoracic, and nonneurosurgical elective surgery. INTERVENTION Patients were randomly assigned at a 2:1 ratio into HSK3486 or propofol groups, to receive HSK3486 (0.4 mg kg −1 ) or propofol (2.0 mg kg −1 ) for induction before a maintenance infusion at initial rates of 0.8 and 5.0 mg kg −1 h −1 , and were adjusted to maintain a bispectral index (BIS) of 40–60 until the end of surgery. MAIN OUTCOME MEASURES Noninferiority between the drugs was evaluated as the lower limit of the 95% confidence interval (CI) for the between-group difference in the success rate of anesthetic maintenance (primary outcome) >−8%. Secondary outcomes included successful anaesthetic induction, full alertness and spontaneous breathing recovery, time until leaving the postanaesthesia care unit and changes in BIS. Safety profiles were also measured. RESULTS Of 129 enrolled patients, 128 completed the trial, with 86 in the HSK3486 group and 42 in the propofol group. The success rate for the maintenance of general anaesthesia was 100% for both groups, and noninferiority of HSK3486 was confirmed (95% CI −4.28% to 8.38%). No significant differences were found between the two groups of patients with regard to secondary outcomes (all P > 0.05). There appeared to be a comparable incidence of treatment for emergency adverse events (TEAEs) (80.2% vs. 81.0%, P = 1.000) and drug-related TEAEs (57.0% vs. 64.3%, P = 0.451) in the HSK3486 and propofol groups. CONCLUSION HSK3486 had a noninferior efficacy profile compared to propofol, exhibiting excellent tolerance. TRIAL REGISTRATION Clinicaltrials.gov, identifier: NCT04511728.