Early Toll-like receptor 4 inhibition improves immune dysfunction in the hippocampus after hypoxic-ischemic brain damage.

Background: Toll-like receptor 4 (TLR4) is implicated in neonatal hypoxic-ischemic brain damage (HIBD), but the underlying mechanism is unclear. Hypothesis: We hypothesized that TLR4 mediates brain damage after hypoxic ischemia (HI) by inducing abnormal neuroimmune responses, including activation of immune cells and expression disorder of immune factors, while early inhibition of TLR4 can alleviate the neuroimmune dysfunction. Method: Postnatal day 7 rats were randomized into control, HI, and HI+TAK-242 (TAK-242) groups. The HIBD model was developed using the Rice-Vannucci method (the left side was the ipsilateral side of HI). TAK-242 (0.5 mg/kg) was given to rat pups in the TAK-242 group at 30 min before modeling. Immunofluorescence, immunohistochemistry, and western blotting were used to determine the TLR4 expression; the number of Iba-1+, GFAP+, CD161+, MPO+, and CD3+ cells; ICAM-1 and C3a expression; and interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and IL-10 expression in the hippocampal CA1 region. Result: Significantly increased TLR4 expression was observed in the left hippocampus, and was alleviated by TAK-242. The significant increases in Iba-1+, MPO+, and CD161+ cells at 24 h and 7 days after HI and in GFAP+ and CD3+ T cells at 7 days after HI were also counteracted by TAK-242, but no significant differences were observed among groups at 24 h after HI. ICAM-1 expression increased 24 h after HI, while C3a expression decreased; TAK-242 also alleviated these changes. TNF-α and IL-1ß expression increased, while IL-10 expression decreased at 24 h and 7 days after HI; TAK-242 counteracted the increased TNF-α and IL-1ß expression at 24 h and the changes in IL-1ß and IL-10 at 7 days, but induced no significant differences in IL-10 expression at 24 h and TNF-α expression at 7 days. Conclusion: Early TLR4 inhibition can alleviate hippocampal immune dysfunction after neonatal HIBD.

The effects of hypoxia on the expression of inflammatory factor high mobility group box-1 in the pulmonary arteriolae of neonatal SD rats / 中国新生儿科杂志

Objective To study the effects of hypoxia on the expression of inflammatory factor high mobility group box-l(HMGB1) in the pulmonary arteriolae of neonatal SD rats.Method A total of 80 neonatal SD rats were randomly assigned into control group and hypoxia-induced persistent pulmonary hypertension of the newborn model (PPHN) group.The PPHN group was subdivided into 2 h,8 h,24 h,and 3 d post-PPHN subgroups according to the time of sacrifice.PPHN model was established on postnatal day 4 when rat pups in PPHN group were kept in low-oxygen box (10％ O2 and 90％ N2) for consecutively 7 days.Multi-channel physiological transducer RM-6280 was used recording the mean pulmonary artery pressure (mPAP) at the root to pulmonary artery of rat pups.ELISA method was used examining the serum level of HMGB1 of rat pups in each group.The pathology of the lung tissue was studied using optical microscope after HE staining,and MIAS-2000 medical image analysis software was used to calculate the ratio of the middle membrane thickness to the outer diameter of the pulmonary arteriolae wall (MT％).Protein level of HMGB1 in the lung was examined using Western Blot.Result The lung pathology in PPHN rats showed thickening of the middle membrane of the pulmonary arteriolae wall and stenosis of the pulmonary arteriolae.MT％ of control group and PPHN group were 5.3％ (3.7％,7.6％) and 7.1％ (4.6％,9.2％),respectively,without significant differences (P＞0.05).At 2 h,8 h,24 h,3 d post-PPHN timepoints,the serum levels of HMGB1 in PPHN group were (13.2±3.1),(15.4±3.6),(17.1±3.5),and (15.8±3.6) ng/ml,respectively,without intra-subgroup differences (F=2.134,P＞0.05),but significant differences existed when compared with control group at each timepoint (P＜0.01).Western Blot showed that HMGB1 protein expression in the lungs were significantly elevated soon after PPHN,peaked at 8～24 h,and reduced but still significantly elevated at 3 d after PPHN comparing with normal control.Significant differences existed at 2 h,8 h,and 24 h timepoints (P＜0.01,respectively).The HMGB1 protein of PPHN group declined significantly at 3 d timepoint without significant differences comparing with the control group (P＞0.05).Conclusion HMGB1 is closely related with the pathogenesis of PPHN,indicating the inflammatory response plays an important role in the mechanisms of PPHN.HMGB1 may be an indicator for the assessment of hypoxia-induced PPHN.

The amplitude integrated electroencephalogram feature of term newborns with different blood glucose level / 中国新生儿科杂志

Objective To study the characteristics of amplitude integrated electroencephalogram (aEEG) in full-term newborns with different blood glucose levels,so as to provide clinical evidence for assessing brain function after hypoglycemia.Method Full-term neonates admitted to the neonatal ward of the Third Xiangya Hospital of Central South University from June 2014 to May 2016 with the initial diagnosis of hypoglycemia were enrolled to hypoglycemia group.According to the lowest level of blood glucose,infants were assigned to three subgroups,severe hypoglycemia group (＜ 1.1 mmol/L),moderate hypoglycemia group (1.1 ～ ＜2.2 mmol/L),and mild hypoglycemia group (2.2 ～ ＜2.8 mmol/L).Time matched asymptomatic term infants,who were admitted to the neonatal ward due to maternal high risks and with normal blood glucose after birth,were enrolled to control group.A 4 h continuous aEEG monitoring was completed for each infant in hypoglycemia group within 12 h after the blood glucose level stabilized.The newborns in control group were given aEEG examination 72 ～ 120 h after birth,the duration of monitoring was also 4 h.The aEEG scoring was completed and compared by rank sum test.Result A total of 83 neonates were enrolled in hypoglycemia group,including 11 with severe hypoglycemia,32 with moderate hypoglycemia,and 40 with mild hypoglycemia.Another 26 neonates with normal blood glucose level were enrolled in control group.The incidence of pregnancy-induced maternal blood glucose elevation was statistically significant among each group (P ＜ 0.05).The duration of neonatal hypoglycemia in severe hypoglycemia group was longer than that in moderate hypoglycemia group and mild hypoglycemia group [38.3 (20.7,50.4) h vs.20.4(15.3,22.6) h,13.7 (7.8,19.4) h] (P＜ 0.05).The range of glucose level in severe hypoglycemia group was larger than that in mild and moderate hypoglycemia group [5.0 (4.0,5.5) mmol/Lvs.3.5 (3.0,3.9) mmol/L,3.3 (2.8,3.8) mmol/L] (P ＜ 0.05),but there was no significant difference in the onset of first hypoglycemia between groups (P ＞ 0.05).The aEEG score showed that there was significant difference in total score and sleep-wake cycle score between groups (P ＜ 0.05).The score of sleep-wake cycle in severe hypoglycemia group was significantly lower than that in moderate hypoglycemia group or in mild hypoglycemia group or in the control group (P ＜ 0.05),while there was no significant difference between moderate and mild hypoglycemia groups,and between moderate hypoglycemia and control group (P ＞ 0.05).Conclusion Severe hypoglycemia can lead to neonatal aEEG changes,mainly in the sleep-wake cycle changes.