ABSTRACT
Objective:To evaluate the effect of vitamin K 2 on traumatic brain injury (TBI) and the relationship with nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes in rats. Methods:Thirty-six SPF healthy male Sprague-Dawley rats, weighing 280-300 g, were divided into 3 groups ( n=12 each) by a random number table method: sham operation group (group Sham), group TBI and TBI plus vitamin K 2 group (group TBI+ VK 2). The TBI model was developed using modified Feeney′s method.In TBI+ VK 2 group, vitamin K 2 400 mg/kg (dissolved in dimethyl sulfoxide) was intraperitoneally injected at 30 min after developing TBI model.The equal volume of dimethyl sulfoxide was intraperitoneally injected in group Sham and group TBI.The modified neurological severity score (mNSS) was measured and open field tests were performed at 24 h after development of TBI.The rats were sacrificed after the end of behavioral testing, and brains were obtained for measurement of brain water content (by wet-dry weight method), percentage of brain injury volume (by TTC assay), contents of interleukin-1β (IL-1β), IL-18 and caspase-1 in cortex on the injured side (by enzyme-linked immunosorbent assay) and expression of NLRP3, caspase-1 and IL-18 in cortex on the injured side (by Western blot). Results:Compared with group Sham, the mNSS score was significantly increased, the total distance travelled was reduced, the time spent in the central zone was shortened, the brain water content and percentage of brain injury volume were increased, the contents of IL-1β, IL-18 and caspase-1 in cortex on the injured side were increased, and the expression of NLRP3, caspase-1 and IL-18 was up-regulated in group TBI ( P<0.05 or 0.01). Compared with group TBI, the mNSS score was significantly decreased, the total distance travelled was increased, the time spent in the central zone was prolonged, the brain water content and percentage of brain injury volume were decreased, the contents of IL-1β, IL-18 and caspase-1 in cortex on the injured side were decreased, and the expression of NLRP3, caspase-1 and IL-18 was down-regulated in group TBI+ VK 2 ( P<0.05 or 0.01). Conclusions:Vitamin K 2 can reduce TBI, and the mechanism may be related to inhibition of the activation of NLRP3 inflammasomes in rats.
ABSTRACT
Objective:To investigate the effect of adenosine deaminase acting on RNA 1 (ADAR1) on 5-serotonin-2c receptor in alleviating aggression in socially isolated mice.Methods:Sixty healthy male BALB / c mice aged 21 days were randomly divided into six groups: social isolation group, social control group, ADAR1 inducer social isolation group, ADAR1 inhibitor social isolation group, ADAR1 inducer social control group and ADAR1 inhibitor control group.The mice fed in single cage for 4 weeks were used as social isolation model while the mice fed in group were used as control group.ADAR1 inducer (5.0×10 4 U/kg) and inhibitor (10 mg/kg) were given intraperitoneally to mice in the ADAR1 inducer social isolation group and the ADAR1 inhibitor social isolation group respectively.The aggressive behavior of mice was evaluated by resident-intruder test.The expression of ADAR1 and 5-serotonin-2c receptors in the brain of mice was detected by immunohistochemistry and Western blot. Results:The attack latency of social isolation group was significantly lower than that of social control group ((43.15±6.99) s, (542.40±30.50) s; t=15.906, P<0.01), and the latency of attack ((256.70±29.49) s) in the ADAR1 inducer social isolation group was significantly higher than that in the social isolation group ( t=7.046, P<0.01). The latency of attack ((15.25±2.18)s) in the ADAR1 inhibitor social isolation group was significantly lower than that in the social isolation group ( t=3.809, P<0.01). The optical density of ADAR1 immunoreactive cells in the amygdala of the social isolation group mice was significantly lower than that in the corresponding brain area of the social control group (BLA: (0.038±0.002), (0.074±0.004); LaDL: (0.033±0.002), (0.060±0.002); LaVM: (0.045±0.003), (0.073±0.004); Lavl area: (0.044±0.003), (0.070±0.003); t=8.428, 9.037, 6.462, 5.698, all P<0.01). The optical density of ADAR1 immunoreactive positive cells in the amygdala (BLA: (0.060±0.003), LaDL: (0.042±0.002), LaVM: (0.056±0.004), Lavl: (0.054±0.003) in the ADAR1 inducer social isolation group was significantly higher than those in the corresponding brain area of the social isolation group mice ( t=6.055, 2.876, 2.312, 2.492; all P<0.05). The expression of ADAR1 protein and 5-serotonin-2c receptor protein in amygdala of social isolation group were significantly lower than those of social isolation group ( t=11.37, 12.65; P<0.01). The expression of ADAR1 protein and 5-serotonin-2c receptor protein in the amygdala of the ADAR1 inducer social isolation group were significantly higher than those of the social isolation group ( t=3.02, 4.401; P<0.05). Conclusion:ADAR1 inducer alleviates the aggressive behavior of social isolated BALB / c mice by enhancing the protein expression of 5-serotonin-2c receptor in the amygdala of social isolated BALB/c mice.
ABSTRACT
Objective To explore the effects of ADAR1 inducer and inhibitor on cognition and ADAR1 expression of isolated BALB/c mice.Methods Sixty healthy BALB/c mice were divided into 6 groups according to randomized design with 10 animals each group,the gregarious control group (GH),social isolation model group (SI),ADAR1 inducer treated gregarious group (GH+IFN-γ),ADAR1 inhibitor treated gregarious group (GH+EHNA),ADAR1 inducer treated isolation group (SI+IFN-γ) and ADAR1 inhibitor treated isolation group (SI+EHNA).Mice in drug treatment groups were treated with ADAR1 inducer (5.0? 104 U/kg,20 ml/kg,ip) and inhibitor (10 mg/kg,20 ml/kg,ip).Objection recognition test was used to measure cognition.Immunohistochenmistry was used to measure ADARI immunoreactivity and Western blotwas used to measure ADAR1 protein expression.Results In the objection recognition test,the non-spatial discrimination index of mice in SI group (-0.16±0.09) was significantly lower than that of GH group (0.41 ±0.17,P＜0.01),the non-spatial discrimination index of mice in SI+IFN-γ group (0.20±0.09) and in SI+ EHNA group (-0.29±0.12) was higher (P＜0.01) and lower (P＜0.05) than that of the SI group respectively.The immunohistochemistry results showed that the ADAR1 immunoreactivity in hippocampus of mice in SI group (Hilus:(0.013±0.003),CAI:(0.021±0.005)) decreased significantly compared to those of GH group(Hilus:(0.021 ±0.002),(0.047±0.004);both P＜0.05).And GH+IFN-γgroup mice showed increased ADAR1 immunoreactivity obviously in Hilus ((0.013±0.003) vs (0.023±0.004),P＜0.01) and in CA1 ((0.021±0.005) vs (0.040±0.005),P＜0.01) compared with that of SI group,ADAR1 inducer recovered the above abnornal ADAR1 immunoreactivity.Western blot results showed that the ADAR1 protein expression of mice in SI group (0.48 ±0.07) in hippocampus was significantly decreased (P＜0.01) compared to that of GH group (1.00 ±0.00).The level of ADAR1 protein in SI+IFN-γgroup(0.82 ±0.04) increased compared with that of SI group.Conclusions Four weeks of social isolation can reduce the non-spatial cognitive ability of BALB/c mice and decrease the expression of ADAR1 in the hippocampus.The ADAR1 inducers and inhibitors can reverse and aggravate the cognitive impairment caused by social isolation respectively.The related mechanisms may be related to the expression of ADAR1.