ABSTRACT
Objective To investigate the protective effects and mechanism of insulin(INS) on brain in septic rats,and explore the possible role of uncoupling protein 2 (UCP2) in these effects.Methods Fifty male specific pathogen free(SPF) Sprague-Dawley rats were randomly divided into normal control (CN) group(n=10),lipopolysaccharide(LPS) group(n=20) and INS group (n=20) according to random number table.The septic rat model was established through an intraperitoneal injection of 15 mg/kg LPS of gram-negative bacteria.The rats in the INS group received a 1 U/kg INS injection subcutaneously 30 minutes before the injection of LPS,and the rats in the CN group were given equivalent 9 g/L saline in the same way.Eight rats in each group were killed,and their cerebral cortex were collected after the injection of LPS for 24 h.Pathological change of cerebral cortex was detected by Hematoxylin-Eosin(HE) staining.The cerebral cortex mitochondia were extracted for detecting the levels of reactive oxygen species(ROS),malondialdehyde (MDA) and the activity of superoxide dismutase(SOD).Neuronal apoptosis was detected by terminal dexynucleotidyl transferase(TdT)-mediated dUTP nick end labeling staining.UCP2 mRNA expression was detected by quantitative real-time(RT)-PCR.Apoptosis-associated protein B lymphocyte tumor-2(Bcl-2),Bcl-2 associated X protein(Bax),cleaved cysteinyl aspartate specific protease(cleaved Caspase-9) and UCP2 protein expression were determined by Western blot.Results (1)Compared with the CN group,obvious abnormal pathological change was revealed by HE staining in cerebral cortex of rats in the LPS group and the INS group,but the pathological change was attenuated in the INS group compared with the LPS group.(2)Compared with the CN group,the levels of mitochondrial ROS[(210.01±14.09) RFU vs.(49.06±7.28) RFU] and MDA[(2.19±0.18) nmol/mg pro vs.(1.25±0.11)nmol/mg pro]in the LPS group significantly increased,whereas SOD activity significantly decreased [(238.49±35.60) U/g pro vs.(446.66±24.90)U/g pro],and the differences were significant(all P<0.05).Compared with the LPS group,the levels of ROS [(152.69±15.83) RFU vs.(210.01±14.09) RFU] and MDA[(1.55±0.14) nmol/mg pro vs.(2.19±0.18) nmol/mg pro] in the INS group decreased,while SOD activity increased[(327.8±23.26) U/g pro vs.(238.49± 35.60) U/g pro],and the differences were significant(all P<0.05).(3)Compared with the CN group,the neuronal apoptosis index of cortex in the LPS group was elevated[(54.16±6.84)% vs.(5.45±1.43)%],while the expression of Bcl-2 decreased (627±0.018 vs.0.739±0.020),but the expressions of Bax(0.768±0.019 vs.0.520±0.010) and cleaved Caspase-9(0.739±0.016 vs.0.467±0.030) increased,and the differences were significant(all P<0.05).Compared with the LPS group,the neuronal apoptosis index of cortex in the INS group decreased [(33.30±3.07)% vs.(54.16±6.84)%],but the Bcl-2 expression increased (0.743±0.022 vs.0.627±0.018),and Bax (0.687±0.034 vs.0.768±0.019) and cleaved Caspase-9(0.551±0.013 vs.0.739±0.016) were reduced,and the differences were significant (all P<0.05).(4)Compared with the CN group,the mRNA (2.248±0.155 vs.1.000±0.100) and protein expression of UCP2 (0.659±0.016 vs.0.599±0.018) were elevated in the LPS group.Compared with the LPS group,the UCP2 mRNA (2.944±0.117 vs.2.248±0.155) and UCP2 protein (0.719±0.018 vs.0.659±0.016) increased,and the differences were significant(all P<0.05).Conclusions INS can protect the brain of septic rats through alleviating mitochondrial oxidative stress and inhibiting the mitochondrial-initiated apoptotic pathway to reduce neuronal apoptosis.INS upregulates UCP2 expression in the brain of septic rats,which may play a role in the protective effects mentioned above.
ABSTRACT
Objective To explore the clinical characteristics of infectious mononucleosis (IM)with Epstein-Barr virus (EBV)and mycoplasma pneumoniae (MP)infection in children.Methods Children with IMwho were all positive for EBV and hospitalized in our department from January 2008 to July 2015 were included and divided into the EBV +MP group and the EBV group according to the results of MP.The manifestations,laboratory variables and outcomes were compared in the two groups.Results Of all these 61 cases,18 children (29.51%)were accompanied with EBV and MP infection.The age of the EBV +MP group was older than the EBV group [(4.44 ±2.75)vs (2.90 ± 2.08)years,t =2.401,P =0.02].Moderate to severe enlarged tonsils,hepatomegaly and complications (especially cough and gastrointestinal symptoms)were more common in the EBV +MP group than the EBV group with significant differences (remarkable tonsillitis:88.89 vs 48.84%,hepatomegaly:55.56 vs 13.95%,complications:72.22 vs 44.19%;χ2 =8.529,10.719 and 3.999 respectively;P =0.003,0.001 and 0.046 respectively).The WBC and lymphocyte counts,percentage of abnormal lymphocyte and the levels of glutamyltranspeptidase in the EBV +MP group were also significantly higher than the EBV group [WBC counts:(18.17 ±7.17)×109 /L vs (13.70 ±7.12)×109 /L], lymphocyte counts:(11.61 ±6.04)×109 /L vs (7.65 ±4.82)×109 /L,abnormal lymphocyte proportion:(20.69 ± 13.03)% vs (13.00 ±11.20)%,serum glutamyltranspeptidase:(99.41 ±91.20)U /L vs (47.95 ±69.22)U /L;t =2.231,2.716,2.215 and 2.239 respectively;P =0.029,0.009,0.031 and 0.029 respectively).But the average hospital stay and the recovery time of manifestations showed no significant differences in the two groups (P >0.05). Conclusion IMchildren with EBV and MP infection have more cases with moderate to severe enlarged tonsils,hepa-tomegaly and complications,moreover present higher lymphocyte and similar outcomes.MP should be tested in all IM children.The early diagnosis and treatment are the keys to improve the prognosis of IM children with EBV and MP infection.