Improved Survival and Neurological Outcomes after Cardiopulmonary Resuscitation in Toll-like Receptor 4-mutant Mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Toll-like receptor 4 (TLR4) is a crucial receptor in the innate immune system and noninfectious immune responses. It has been reported that TLR4 participates in the pathological course of ischemia/reperfusion (I/R) injury. However, the role of TLR4 in the process of I/R injury after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) is still unknown. In this study, we investigated the effects of TLR4 mutation on survival and neurological outcome in a mouse model of CA/CPR.</p><p><b>METHODS</b>A model of potassium-induced CA was performed on TLR4-mutant mice (C3H/HeJ) and wild-type mice (C3H/HeN). After 3 min of untreated CA, resuscitation was attempted with chest compression, ventilation, and intravenous epinephrine. Behavioral tests were performed on mice on day 3 after CPR. The morphological changes in hippocampal neurons were assessed by light and electron microscopy. Expressions of TLR4 and intercellular adhesion molecule-1 (ICAM-1) were detected by Western blot. Levels of tumor necrosis factor-α (TNF-α) and myeloperoxidase (MPO) were measured with enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>On day 3 after resuscitation the overall mortality was 33.33% in C3H/HeJ group compared with 53.33% in C3H/HeN group (P < 0.05). And there was much higher central tendency in C3H/HeJ group than C3H/HeN group during open field test (P < 0.05). Meanwhile, the percentage of nonviable neurons was 21.16% in C3H/HeJ group compared with 53.11% in C3H/HeN group (P < 0.05). And there were significantly lower levels of hippocampal TNF-α and MPO in C3H/HeJ mice (TNF-α: 6.85±1.19 ng/mL, MPO: 0.33±0.11 U/g) than C3H/HeN mice (TNF-α: 11.36±2.12 ng/mL, MPO: 0.54±0.17 U/g) (all P < 0.01). CPR also significantly increased the expressions of TLR4 and ICAM-1 in C3H/HeN group. However, the expression of ICAM-1 was much lower in C3H/HeJ group than in C3H/HeN group after CPR (P < 0.01).</p><p><b>CONCLUSION</b>TLR4 signaling is involved in brain damage and in inflammation triggered by CA/CPR.</p>

Effect of SP-A/B in lipoic acid on acute paraquat poisoning / 世界急诊医学杂志（英文）

BACKGROUND:This study was undertaken to observe the concentration of SP-A/B and the pulmonary surfactant in the lung tissue of rats with acute lung injury/acute respiratory distress syndrome caused by paraquat poisoning after the treatment of metabolic antioxidant-lipoic acid and whether its influence was related to TNF-α. METHODS:Sixty-six male Sprage-Dawley rats were randomly divided into three groups:normal control group (NS group), 6 rats; paraquat poisoning group (PQ group), 30 rats; and paraquat+lipoic acid treatment group (LA group), 30 rats. The rats in the PQ and LA groups were subdivided into 3-, 6-, 12-, 24-, 48-hour subgroups, with 6 rats in each group. After the rats were sacrificed, lung tissue from the same part was taken from the rats. After HE staining, histological changes were observed in the tissue under a light microscope. Lung tissue was also taken to test the levels of superoxide dismutase (SOD) and malondialdehyde (MDA). Whole blood (0.8 mL) without anticoagulant was drawn from the tail vein of rats for the determination of the TNF-α level. The total RNA of the lung tissue was collected, and the Rt-PCR method was used to measure the levels of SP-A and SP-B mRNA. RESULTS:HE staining showed that histopathological changes were milder in the LA group than in the PQ group. There were significant differences in MDA and SOD levels between different intervals both in intergroups and intragroups except the 3-hour subgroup (P<0.01). Likewise, the significant differences in the levels of TNF-α were also present between the three groups and between different intervals (P<0.01). The significant differences in SP-A mRNA and SP-B mRNA amplification ratio were seen between the three groups at the same intervals (P<0.01), but the differences between different intervals in the PQ group were statistically significant (P<0.05). The differences between different intervals in the LA group were statistically significant (P<0.01). CONCLUSION:Lipoic acid in acute paraquat poisoning could diminish lung tissue damage by regulating directly tumor necrosis factor and indirectly the content of pulmonary surfactant so as to reduce pulmonary edema, improve lung compliance, and finally protect lung tissues.

Upregulated expression of S100A8 in mice brain after focal cerebral ischemia reperfusion / 世界急诊医学杂志（英文）

BACKGROUND:Recent studies have showed that S100A8 has been implicated in the pathobiology of inflammatory disorders, and that cerebral ischemia reperfusion (I/R) rapidly activates inflammation responses via Toll-like receptor 4 (TLR4). This study aimed to explore the expression of S100A8 and the relationship between S100A8 and TLR4 in focal cerebral ischemia reperfusion injury.METHODS:C3H/HeJ mice (n=30) and C3H/HeN mice (n=30) were divided randomly into a C3H/HeJ model group (n=18), a C3H/HeJ control group (n=12), a C3H/HeN model group (n=18), and a C3H/HeN control group (n=12). Middle cerebral artery I/R model in mice was produced using a thread embolism method. The brains of the mice were collected after ischemia for 1 hour and reperfusion for 12 hours. Stroke outcome was evaluated by determination of infarct volume and assessment of neurological impairment scores. Brain injury after cerebral I/R was observed by an optical microscope after TTC and HE dyeing. The immunofluorescence technique and real time PCR were used to test the expression level of S100A8 in brain damage.RESULTS:Compared with C3H/HeN mice, TLR4-deficient mice (C3H/HeJ) had lower infarct volumes and better outcomes in neurological tests. The levels of S100A8 increased sharply in the brains of mice after I/R injury. In addition, mice that lacked TLR4 (C3H/HeJ) had lower expression of I/R-induced S100A8 than C3H/HeN mice in the model group, indicating that a close relationship might exist between the levels of S100A8 and TLR4.CONCLUSION:S100A8 interaction with TLR4 might be involved in brain damage and in inflammation triggered by I/R injury.

Edaravone attenuates paraquat-induced lung injury by inhibiting oxidative stress in human type Ⅱ alveolar epithelial cells / 世界急诊医学杂志（英文）

BACKGROUND: Edaravone (3-methyl-1-penyl-2-pyrazolin-5-one) is a potent free-radical scavenger and has the antioxidant ability to inhibit lipid peroxidation. The study aimed to examine the effect of edaravone on protecting the acute injury of human type Ⅱ alveolar epithelial cells (A549 cells) induced by paraquat (PQ) and the change of production of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD). METHODS: A549 cells were cultured and divided into PQ group (group P), edaravone-treated group (group E) and normal control group (group C). The cells in group P were exposed to paraquat (600 mol/L), and the cells in group E were treated with edaravone (100 mol/L) additionally, and no drug intervention was given to the cells in group C. Real-time monitoring by LSCM was used to detect the cell response and the intracellular dynamic change of ROS level in A549 cells after administration of PQ and edaravone. And the levels of SOD and MDA were detected respectively by biochemistry colorimetry. Data were expressed as mean ± standard error of the mean. Statistical analysis was carried out with the soft SPSS 16.0. RESULTS: The concentration of intracellular ROS significantly increased when PQ was given to A549 cells. But after administration of edaravone, the concentration of intracellular ROS was decreased. Compared to the PQ group, the levels of SOD in the edaravone group were significantly increased while the levels of MDA were markedly decreased. CONCLUSIONS: Paraquat can increase the oxidative stress, and induce the lipid peroxidation of A549 cells. Edaravone has the effect to scavenge reactive oxygen species, and to protect against the PQ-induced lung toxicity.