Abstract:Aim To investigate the effect of edaravone dexborneol (ED) on microglial polarization in rats with brain injury caused by hydraulic shock, and explore its mechanism based on Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway. Methods 32 rats of 205 healthy male SD rats were randomly selected as sham group, the remaining 173 rats were prepared with brain injury model by hydraulic shock method, and 160 model rats were randomly divided into model group, ED (7 mg/kg) group, TAK242 (ressatovir, TLR4 inhibitor, 2 mg/kg) group, ED (7 mg/kg)＋TAK242 (2 mg/kg) group and ED (7 mg/kg)＋lipolyaccharide (LPS, TLR4 agonist, 0.4 mg/kg) group, with 32 rats in each group. After 14 days of continuous intraperitoneal injection once a day, the nerve function, brain water content and blood-brain barrier (BBB) permeability were measured by modified neurological severity score (mNSS), weightlessness method or Evans blue (EB) penetration method, the brain histopathological changes was observed by HE and Nissl staining, the levels of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin (IL) 1β, IL-4 and IL-10 in brain tissue were detected by ELISA, the M1 polarization phenotype (CD86/Iba-1) and M2 polarization phenotype (CD206/Iba-1) of microglia cells were detected by immunofluorescence double staining, the mRNA and protein expressions of TLR4, NF-κB p65, NOD-like receptor protein 3 (NLRP3), aquaporin 4 (AQP4) were detected by RT-PCR or Western blot. Results Compared with the model group, the mNSS score, brain water content, BBB permeability of the rats in ED group, TAK242 group, ED＋TAK242 group were significantly were decreased (P＜0.05), the pathological changes such as brain structure disorder, sparse and disordered neuronal arrangement, vacuole-like transformation, inflammatory cell infiltration, decrease in the number of Nishi bodies were significantly improved, the levels of IFN-γ, TNF-α, IL-1β in brain tissue were significantly decreased, while the levels of IL-4, IL-10 were significantly increased (P＜0.05), the mRNA and protein expressions of TLR4, NF-κB p65, NLRP3, AQP4 were significantly decreased (P＜0.05). TAK242 could significantly enhance the regulatory effects of ED on nerve function, brain water content, BBB permeability, inflammatory response, microglia polarization, TLR4/NF-κB signaling pathway related mRNA and protein expression of the rats with hydraulic shock brain injury (P＜0.05), while LPS could significantly reverse the above regulatory effects of ED on the rats with hydraulic shock brain injury (P＜0.05). Conclusion ED may promote the polarization of microglia from M1 phenotype to M2 phenotype by inhibiting TLR4/NF-κB signaling pathway, inhibit inflammatory response and BBB permeability increasing, and thus play a protective role in brain injury caused by hydraulic shock in rats.

Abstract:Aim To investigate the effect and mechanism of hydrogen molecule on myocardial injury in severe traumatic brain injury (TBI) rats. Methods Using the fluid percussion injury (FPI)-induced TBI model. 72 SD rats were randomly divided into sham group, TBI group and hydrogen molecule-treated group, with 24 rats in each group, and the rats were executed at 48 h after the operation. HE staining was used to observe the myocardial injury and the infiltration of granulocytes, ELISA was used to detect the level of superoxide dismutase (SOD), Western blot was used to detect the expression of inflammation-related factors myeloperoxidase (MPO) and heme oxygenase-1 (HO-1) protein, RT-qPCR was used to detect the levels of cardiac troponin T (cTnT), inhibitory factor-1 (IF-1), NADH/ubiquinone oxidoreductase core subunit S7 (NDUFS7), nicotinamide adenine dinucleotide phosphate (NADP) and reduced nicotinamide adenine dinucleotide phosphate (NADPH). The changes of post-traumatic echocardiography and the 7-day survival rate and body weight in the rats were observed and recorded. Results Compared with the sham group, rats in the TBI group had significantly higher troponin levels, and the echocardiographic results showed higher left ventricular end-diastolic diameter (LVEDD) and significantly lower left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), and the above pathologic changes were significantly improved after treatment with the hydrogen molecule. Myocardial tissue was disorganized with erythrocyte infiltration, and myocardial fibers were infiltrated with granulocytes in the section, which were improved in the hydrogen molecule-treated group. The body weight of the rats decreased dramatically after the operation, and about 5 days later dropped to the lowest level, and then showed a trend of slow recovery. mNSS scores showed that the neurological function of the rats was severely impaired after TBI, and the postoperative myocardial tissues showed an increase in the expression levels of MPO and HO-1 proteins and a decrease in the expression levels of SOD, and the above pathological changes were significantly improved by hydrogen molecule treatment. In the TBI group, the expression levels of NADPH, IF-1 and NDUFS7 were reduced, and the expression levels of the above indicators were significantly increased after hydrogen molecule treatment. Conclusion Hydrogen molecule may be able to increase mitochondrial energy metabolism in cardiomyocytes and reduce myocardial oxidative stress by synergistically enhancing the protein expression of IF-1 and NDUFS7 on the mitochondrial oxidative respiratory chain to increase cardiac function and survival rate in the acute phase of TBI.

Abstract:Aim To study effects of mangiferin on oxidative stress response and neuronal apoptosis in rats with hypoxic-ischemic brain injury by PI3K/Akt/mTOR pathway. Methods 144 neonatal SD rats were randomly divided into 6 groups:blank control group, model group, positive control group (Nimodipine), mangiferin low dose group (MAN-L), middle dose group (MAN-M) and high dose group (MAN-H). There were 24 rats in each group. The rat model of hypoxic-ischemic brain injury was made in all groups except the blank control group. After the model was made, the blank control group and the model group were given the same volume of normal saline, the positive control group was given nimodipine (0.4 mg/(kg·d)), and the mangiferin low, middle and high dose groups were given mangiferin 0,0, 200 mg/(kg·d) for 4 weeks. The neurological injury score of rats in each group was measured, the water content of brain tissue in each group was measured by dry and wet weight method, the pathomorphological changes of brain tissue were observed by hematoxylin-eosin (HE) staining, and the apoptosis of neurons in brain tissue of rats was detected by in situ apoptosis. The activities of superoxide dismutase (SOD), malondialdehyde (MDA), glutathion peroxidase (GSH-Px) and total antioxidant capacity (T-AOC) in brain tissue were measured by biochemical detection, and the expression of PI3K/Akt/mTOR mRNA in rat brain tissue was measured by real-time fluorescence quantitative polymerase chain reaction (Real-time PCR). The contents of caspase-3, Bcl-2, Bcl-xL, Bad and Bax proteins in brain tissue were detected by Western blot. Results The nerve injury score, water content of brain tissue, apoptosis number of nerve cells, MDA content, PI3K expression and caspase-3 content in the model group were significantly higher than those in the blank control group. The number of intact neurons, the contents of SOD, GSH-Px, T-AOC, Akt, mTOR and the contents of Bcl-2, Bcl-xL and Bad in the brain tissue of the model group were significantly lower than those of the blank control group. The nerve injury score, water content of brain tissue, apoptosis number of nerve cells, MDA content, PI3K expression and caspase-3 content in each drug group were significantly lower than those in the model group. The number of intact neurons, the contents of SOD, GSH-Px, T-AOC, Akt, mTOR and the contents of Bcl-2, Bcl-xL and Bad in the brain tissue of the drug group were significantly higher than those of the model group. Conclusion Mangiferin can enhance the neuroprotective effect, inhibit neuronal apoptosis and improve the survival rate of nerve cells by down-regulating the expression of caspase-3, up-regulating the expression of Bcl-2 and Bcl-xL, and enhancing the expression of PI3K/Akt/mTOR pathway.