Objective:To investigate the effect of early high-sucrose diet (eHSD) on cognitive function and its regulatory mechanism in 3×Tg-AD mice.Methods:(1) Eighteen specific-pathogen-free (SPF)-grade 2-month-old wide-type (WT) mice were randomly divided into a WT+normal chow diet (NCD) group and a WT+eHSD group, with 9 mice in each group; and 18 SPF-grade 2-month-old 3×Tg-AD mice were randomly divided into a 3×Tg-AD+NCD group and a 3×Tg-AD+eHSD group, with 9 mice in each group. At 2-5 months old, mice in the 4 groups received standard laboratory food+purified water or 30% sucrose water, followed by standard feed for all groups. At 8 months old, cognitive function was assessed by Morris water maze test; fluorescent intensity of AT8 (phosphorylated [p]-tau) and T22 (tau oligomers) in the hippocampal tissues was detected by immunofluorescent staining; concentrations of β-amyloid protein (Aβ) 42 and Aβ 40 were detected by enzyme-linked immunosorbent assay (ELISA); protein expressions of stimulator of interferon genes (STING), TANK-binding kinase 1 (TBK1), p-TBK1, and CCAAT/enhancer-binding protein β (C/EBPβ) were detected by Western blotting; activity of C/EBPβ transcription factor was detected by activity assay; mitochondrial DNA (mtDNA) content in the cytoplasm of cell was detected by real-time quantitative PCR (qPCR). (2) Eighteen SPF-grade 2-month-old 3×Tg-AD mice were randomized into a 3×Tg-AD+eHSD+H-151 group and a 3×Tg-AD+eHSD+dimethyl sulfoxide (DMSO) group, with 9 mice in each group. Mice at 2-5 months old were given standard laboratory food+30% sucrose water; they were, respectively, injected intraperitoneally with STING pathway inhibitor H-151 or DMSO at 5 months old, and continually injected until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, Western blotting and C/EBPβ transcription factor activity experiments were repeated as before. (3) After crossing C/EBPβ heterozygous knockout (C/EBPβ +/-) mice with 3×Tg-AD mice, 3×Tg-AD/C/EBPβ +/- mice were obtained, and 3×Tg-AD mice were used as controls; they were named 3×Tg-AD/C/EBPβ +/-+eHSD group and 3×Tg-AD+eHSD group, with 9 mice in each group. Both groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old, followed by standard feed until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. (4) C/EBPβ transgenic mice (C/EBPβTg) were crossed with 3×Tg-AD mice to obtain C/EBPβTg/3×Tg-AD mice, and Non-Tg/3×Tg-AD mice were used as controls; they were, respectively, named as C/EBPβTg/3×Tg-AD+eHSD+H-151 group, Non-Tg/3×Tg-AD+eHSD+H-151 group, and Non-Tg/3×Tg-AD+eHSD+DMSO group, with 9 mice in each group. All 3 groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old; at 5-8 months old, mice in the C/EBPβTg/3×Tg-AD+eHSD+H-151 group and Non-Tg/3×Tg-AD+eHSD+H-151 group were intraperitoneally injected with H-151, while mice in the Non-Tg/3×Tg-AD+eHSD+DMSO group were injected with DMSO; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. Results:(1) Compared with those in the WT+NCD group and WT+eHSD group, area under the latency curve of 3×Tg-AD+eHSD mice was significantly increased, and proportion of time spending in the targeted quadrant of mice in the 3×Tg-AD+NCD group and 3×Tg-AD+eHSD group was significantly decreased ( P<0.05); compared with that in the 3×Tg-AD+NCD group, proportion of time spending in the targeted quadrant in mice of the 3×Tg-AD+eHSD group was significantly reduced ( P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.076 vs. 2.902±0.399; T22 fluorescent intensity: 1.000±0.145 vs. 2.495±0.273; Aβ 42: 1.000±0.167 vs.1.956±0.132; Aβ 40: 1.000±0.226 vs.1.900±0.116), significantly increased C/EBPβ protein expression and C/EBPβ transcription factor activity (1.000±0.164 vs. 1.804±0.112; 1.000±0.216 vs. 2.743±0.301), and statistically increased mtDNA level detected by D-loop1 and D-loop3 (1.000±0.234 vs. 2.800±0.210; 1.000±0.155 vs. 2.952±0.078; P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.192 vs. 2.093±0.081; p-TBK1/TBK1: 1.000±0.148 vs. 1.561±0.112, P<0.05). (2) Compared with the 3×Tg-AD+eHSD+DMSO group, the 3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers expressions, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.142 vs. 0.538±0.057; T22 fluorescent intensity: 1.000±0.104 vs. 0.665±0.088; Aβ 42: 1.000±0.084 vs. 0.600±0.007; Aβ 40: 1.000±0.138 vs. 0.476±0.083), significantly decreased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.054 vs. 0.468±0.111; p-TBK1/TBK1: 1.000±0.057 vs. 0.598±0.090), and significantly decreased C/EBPβ transcription factor activity (1.000±0.097 vs. 0.445±0.106; P<0.05). (3) Compared with the 3×Tg-AD+eHSD group, the 3×Tg-AD/C/EBPβ +/-+eHSD group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.160 vs. 0.506±0.065; T22 fluorescent intensity: 1.000±0.127 vs. 0.346±0.048; Aβ 42: 1.000±0.017 vs. 0.510±0.101; Aβ 40: 1.000±0.098 vs. 0.586±0.153), and significantly decreased C/EBPβ protein expression (1.000±0.101 vs. 0.568±0.094; P<0.05). (4) Compared with the Non-Tg/3×Tg-AD+eHSD+DMSO group, the Non-Tg/3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, and significantly decreased p-tau and tau oligomers expressions, Aβ 40 concentration in the hippocampus, and the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly decreased STING protein expression and p-TBK1/TBK1 ratio in the hippocampus ( P<0.05). Compared with the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly increased area under the latency curve, significantly decreased proportion of time spending in the targeted quadrant, and significantly increased p-tau and tau oligomers expressions, Aβ 40 and Aβ 42 concentration in the hippocampus ( P<0.05). Conclusion:The eHSD aggravates cognitive impairment in 3×Tg-AD mice through activating cGAS-STING-C/EBPβ pathway.

AIM:To investigate the modulatory role of E3 ubiquitin-protein ligase ITCH in Alzheimer disease(AD)-like pathology through the thioredoxin-interacting protein(TXNIP)-nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)signaling pathway using both in vivo and in vitro experimental models.METHODS:(1)Ten 5×FAD(AD model)mice and 10 wild-type(WT)mice at 2-,4-and 6-month-old were randomly allocated into AD and WT groups.Amyloid β-protein(Aβ)plaque burden in the brain was detected by thioflavin-S and immunofluorescence staining,with the latter method additionally applied to assess TXNIP protein expression.The protein levels of ITCH and TXNIP were determined by Western blot,while their interaction was verified by co-immunoprecipitation.(2)Mouse mi-croglia BV2 cells stimulated by lipopolysaccharide(LPS)were used to construct neuroinflammation model,and were di-vided into control(CON)group and LPS+ATP treatment group.The BV2 cells stimulated by Aβ were used to construct AD inflammation model.According to the different treatment time,they were divided into CON,and 12,24 and 48 h treatment groups.Western blot was used to evaluate the expression of ITCH,TXNIP,and NLRP3 inflammasome compo-nents(NLRP3 and caspase-1)as well as the downstream IL-1β.Adenovirus-mediated ITCH overexpression(OE-ITCH)in Aβ-stimulated BV2 cells comprised three experimental groups:negative control group,Aβ oligomer stimulation group,and OE-ITCH group,with subsequent immunoblotting of inflammatory mediators.RESULTS:The deposition of Aβ plaques in the cortex and hippocampus of 5×FAD transgenic mice exhibited an age-dependent progression(P<0.01).Compared with WT mice,the levels of TXNIP protein increased synchronously,and the levels of ubiquitin ligase ITCH was significantly down-regulated(P<0.05).Co-immunoprecipitation confirmed the interaction between ITCH and TXNIP proteins in the brain of 2-and 4-month-old 5×FAD mice,which exhibited marked attenuation by 4 months of age.In BV2 microglial models,Aβ/LPS stimulation provoked significant ITCH suppression,concurrently up-regulating TXNIP,core NLRP3 inflammasome components(NLRP3 and caspase-1),and downstream IL-1β(P<0.05).Overexpression of ITCH significantly inhibited Aβ-induced activation of TXNIP and NLRP3 and therelated inflammatory factors in BV2 cells.CONCLUSION:The results of in vitro and in vivo experiments showed that ITCH protein exerts effects against AD-like pathology by inhibiting the expression of TXNIP-NLRP3 signaling pathway.

AIM:To investigate the modulatory role of E3 ubiquitin-protein ligase ITCH in Alzheimer disease(AD)-like pathology through the thioredoxin-interacting protein(TXNIP)-nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)signaling pathway using both in vivo and in vitro experimental models.METHODS:(1)Ten 5×FAD(AD model)mice and 10 wild-type(WT)mice at 2-,4-and 6-month-old were randomly allocated into AD and WT groups.Amyloid β-protein(Aβ)plaque burden in the brain was detected by thioflavin-S and immunofluorescence staining,with the latter method additionally applied to assess TXNIP protein expression.The protein levels of ITCH and TXNIP were determined by Western blot,while their interaction was verified by co-immunoprecipitation.(2)Mouse mi-croglia BV2 cells stimulated by lipopolysaccharide(LPS)were used to construct neuroinflammation model,and were di-vided into control(CON)group and LPS+ATP treatment group.The BV2 cells stimulated by Aβ were used to construct AD inflammation model.According to the different treatment time,they were divided into CON,and 12,24 and 48 h treatment groups.Western blot was used to evaluate the expression of ITCH,TXNIP,and NLRP3 inflammasome compo-nents(NLRP3 and caspase-1)as well as the downstream IL-1β.Adenovirus-mediated ITCH overexpression(OE-ITCH)in Aβ-stimulated BV2 cells comprised three experimental groups:negative control group,Aβ oligomer stimulation group,and OE-ITCH group,with subsequent immunoblotting of inflammatory mediators.RESULTS:The deposition of Aβ plaques in the cortex and hippocampus of 5×FAD transgenic mice exhibited an age-dependent progression(P<0.01).Compared with WT mice,the levels of TXNIP protein increased synchronously,and the levels of ubiquitin ligase ITCH was significantly down-regulated(P<0.05).Co-immunoprecipitation confirmed the interaction between ITCH and TXNIP proteins in the brain of 2-and 4-month-old 5×FAD mice,which exhibited marked attenuation by 4 months of age.In BV2 microglial models,Aβ/LPS stimulation provoked significant ITCH suppression,concurrently up-regulating TXNIP,core NLRP3 inflammasome components(NLRP3 and caspase-1),and downstream IL-1β(P<0.05).Overexpression of ITCH significantly inhibited Aβ-induced activation of TXNIP and NLRP3 and therelated inflammatory factors in BV2 cells.CONCLUSION:The results of in vitro and in vivo experiments showed that ITCH protein exerts effects against AD-like pathology by inhibiting the expression of TXNIP-NLRP3 signaling pathway.

Objective:To investigate the effect of early high-sucrose diet (eHSD) on cognitive function and its regulatory mechanism in 3×Tg-AD mice.Methods:(1) Eighteen specific-pathogen-free (SPF)-grade 2-month-old wide-type (WT) mice were randomly divided into a WT+normal chow diet (NCD) group and a WT+eHSD group, with 9 mice in each group; and 18 SPF-grade 2-month-old 3×Tg-AD mice were randomly divided into a 3×Tg-AD+NCD group and a 3×Tg-AD+eHSD group, with 9 mice in each group. At 2-5 months old, mice in the 4 groups received standard laboratory food+purified water or 30% sucrose water, followed by standard feed for all groups. At 8 months old, cognitive function was assessed by Morris water maze test; fluorescent intensity of AT8 (phosphorylated [p]-tau) and T22 (tau oligomers) in the hippocampal tissues was detected by immunofluorescent staining; concentrations of β-amyloid protein (Aβ) 42 and Aβ 40 were detected by enzyme-linked immunosorbent assay (ELISA); protein expressions of stimulator of interferon genes (STING), TANK-binding kinase 1 (TBK1), p-TBK1, and CCAAT/enhancer-binding protein β (C/EBPβ) were detected by Western blotting; activity of C/EBPβ transcription factor was detected by activity assay; mitochondrial DNA (mtDNA) content in the cytoplasm of cell was detected by real-time quantitative PCR (qPCR). (2) Eighteen SPF-grade 2-month-old 3×Tg-AD mice were randomized into a 3×Tg-AD+eHSD+H-151 group and a 3×Tg-AD+eHSD+dimethyl sulfoxide (DMSO) group, with 9 mice in each group. Mice at 2-5 months old were given standard laboratory food+30% sucrose water; they were, respectively, injected intraperitoneally with STING pathway inhibitor H-151 or DMSO at 5 months old, and continually injected until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, Western blotting and C/EBPβ transcription factor activity experiments were repeated as before. (3) After crossing C/EBPβ heterozygous knockout (C/EBPβ +/-) mice with 3×Tg-AD mice, 3×Tg-AD/C/EBPβ +/- mice were obtained, and 3×Tg-AD mice were used as controls; they were named 3×Tg-AD/C/EBPβ +/-+eHSD group and 3×Tg-AD+eHSD group, with 9 mice in each group. Both groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old, followed by standard feed until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. (4) C/EBPβ transgenic mice (C/EBPβTg) were crossed with 3×Tg-AD mice to obtain C/EBPβTg/3×Tg-AD mice, and Non-Tg/3×Tg-AD mice were used as controls; they were, respectively, named as C/EBPβTg/3×Tg-AD+eHSD+H-151 group, Non-Tg/3×Tg-AD+eHSD+H-151 group, and Non-Tg/3×Tg-AD+eHSD+DMSO group, with 9 mice in each group. All 3 groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old; at 5-8 months old, mice in the C/EBPβTg/3×Tg-AD+eHSD+H-151 group and Non-Tg/3×Tg-AD+eHSD+H-151 group were intraperitoneally injected with H-151, while mice in the Non-Tg/3×Tg-AD+eHSD+DMSO group were injected with DMSO; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. Results:(1) Compared with those in the WT+NCD group and WT+eHSD group, area under the latency curve of 3×Tg-AD+eHSD mice was significantly increased, and proportion of time spending in the targeted quadrant of mice in the 3×Tg-AD+NCD group and 3×Tg-AD+eHSD group was significantly decreased ( P<0.05); compared with that in the 3×Tg-AD+NCD group, proportion of time spending in the targeted quadrant in mice of the 3×Tg-AD+eHSD group was significantly reduced ( P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.076 vs. 2.902±0.399; T22 fluorescent intensity: 1.000±0.145 vs. 2.495±0.273; Aβ 42: 1.000±0.167 vs.1.956±0.132; Aβ 40: 1.000±0.226 vs.1.900±0.116), significantly increased C/EBPβ protein expression and C/EBPβ transcription factor activity (1.000±0.164 vs. 1.804±0.112; 1.000±0.216 vs. 2.743±0.301), and statistically increased mtDNA level detected by D-loop1 and D-loop3 (1.000±0.234 vs. 2.800±0.210; 1.000±0.155 vs. 2.952±0.078; P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.192 vs. 2.093±0.081; p-TBK1/TBK1: 1.000±0.148 vs. 1.561±0.112, P<0.05). (2) Compared with the 3×Tg-AD+eHSD+DMSO group, the 3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers expressions, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.142 vs. 0.538±0.057; T22 fluorescent intensity: 1.000±0.104 vs. 0.665±0.088; Aβ 42: 1.000±0.084 vs. 0.600±0.007; Aβ 40: 1.000±0.138 vs. 0.476±0.083), significantly decreased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.054 vs. 0.468±0.111; p-TBK1/TBK1: 1.000±0.057 vs. 0.598±0.090), and significantly decreased C/EBPβ transcription factor activity (1.000±0.097 vs. 0.445±0.106; P<0.05). (3) Compared with the 3×Tg-AD+eHSD group, the 3×Tg-AD/C/EBPβ +/-+eHSD group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.160 vs. 0.506±0.065; T22 fluorescent intensity: 1.000±0.127 vs. 0.346±0.048; Aβ 42: 1.000±0.017 vs. 0.510±0.101; Aβ 40: 1.000±0.098 vs. 0.586±0.153), and significantly decreased C/EBPβ protein expression (1.000±0.101 vs. 0.568±0.094; P<0.05). (4) Compared with the Non-Tg/3×Tg-AD+eHSD+DMSO group, the Non-Tg/3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, and significantly decreased p-tau and tau oligomers expressions, Aβ 40 concentration in the hippocampus, and the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly decreased STING protein expression and p-TBK1/TBK1 ratio in the hippocampus ( P<0.05). Compared with the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly increased area under the latency curve, significantly decreased proportion of time spending in the targeted quadrant, and significantly increased p-tau and tau oligomers expressions, Aβ 40 and Aβ 42 concentration in the hippocampus ( P<0.05). Conclusion:The eHSD aggravates cognitive impairment in 3×Tg-AD mice through activating cGAS-STING-C/EBPβ pathway.

OBJECTIVE: To explore association of the expression levels of adenylate cyclase-associated protein 2 (CAP2) in gastric cancer tissues with the histopathology and long-term prognosis of the malignancy. METHODS: This study was conducted among a total of 105 patients with gastric cancer undergoing radical gastrectomy in our hospital between January, 2010 and October, 2013. Immunohistochemistry was used to quantitatively assess the expression of CAP2 in gastric cancer tissues and the adjacent tissues. Based on the median relative expression level of CAP2 of 3.5, the patients were divided into low CAP2 expression group (=52) and high CAP2 expression group (=53). The Cox regression model was used to analyze the effect of CAP2 expression on the 5-year survival rate of the patients, and ROC curve analysis was used to assess the predictive value of CAP2 expression for the patients' long-term survival. RESULTS: Immunohistochemical analysis showed that the expression levels of CAP2 ( < 0.01) and Ki67 ( < 0.01) were significantly higher in gastric cancer tissues than in the adjacent tissues, and the expression level of CAP2 was positively correlated with Ki67 ( < 0.01), peripheral blood CEA ( < 0.01) and CA19-9 ( < 0.01). The percentages of patients with CEA≥5 μg/L, CA19-9≥37 kU/L, pathological grade of G3-G4, T stage of 3-4, and N stage of 2-3 were significantly higher in patients with high CAP2 expression than in those with low CAP2 expression ( < 0.05). Kaplan- Meier survival analysis showed that the 5-year survival rate was significantly lower in patients with a high CAP2 expression ( < 0.01). A high expression level of CAP2, CEA≥5μg/L, CA19-9≥37 and pathological grades G3-G4 were all independent risk factors for shortened 5-year survival after radical gastrectomy ( < 0.01). With the relative expression level of 3.45 as the cut-off value, the sensitivity of CAP2 was 70.15% for predicting death 5 years after the surgery, with a specificity of 71.05% and an area under the curve of 0.779 ( < 0.01). CONCLUSIONS CAP2 is highly expressed in gastric cancer tissues in close relation with the tumor progression. CAP2 is an independent risk factor for 5-year survival rate after radical gastrectomy for gastric cancer and can be of clinical value in prognostic evaluation of the patients.
Adaptor Proteins, Signal Transducing ; metabolism ; Gastrectomy ; Humans ; Immunohistochemistry ; Membrane Proteins ; metabolism ; Neoplasm Staging ; Prognosis ; Retrospective Studies ; Stomach Neoplasms ; diagnosis ; metabolism ; pathology ; Survival Rate

Objective To evaluate the role of phosphatidylinositol 3-kinase (PI3K) p110β in spinal dorsal horn neurons in the development of arthritic pain (AP) in rats and the relationship with transient receptor potential vanilloid 1 (TRPV1) and acid-sensing ion channel (ASIC)1 a.Methods Forty adult female Sprague-Dawley rats in which intrathecal catheters were successfully placed,aged 3 months,weighing 250-300 g,were randomly divided into 4 groups (n =10 each):control group (group C),group AP,AP + PI3K p110β missense oligo-deoxynucleotide group (group MS) and AP + PI3K p110β antisense oligo-deoxynucleotide group (group AS).AP was induced by injecting complete Freund's adjuvant into the ankle joint cavity of right hindpaw.Normal saline 20 μl,missense oligo-deoxynucleotide 15 μg (20μl) and antisense oligo-deoxynucleotide 15 μg (20 μl) were administered intrathecally once a day for 6 consecutive days starting from the time immediately after arthritis was induced in groups AP,MS and AS,respectively.Mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured 1 day before operation (T0) and on days 4,7,10 after operation (T1-3).The rats were then sacrificed after the last measurement of pain threshold at T3.L4-6 segment of the spinal cord was removed for detection of expression of PI3K p110β (by Western blot),and TRPV1 and ASICla (by immunohistochemistry)in spinal dorsal horn neurons.Results Compared with group C,MWT and TWL were significantly decreased atT1-3,and the expression of PI3K p110β,TRPV1 and ASIC1a was up-regulated in the other 3 groups(P＜ 0.01).MWT and TWL were significantly higher at T1-3,and the expression of PI3K p110β,TRPV1 and ASIC1a was lower in group AS than in groups AP and MS (P ＜ 0.01).Conclusion PI3K p110β in spinal dorsal horn neurons is involved in the development of AP in rats,and the mechanism is related to up-regulation of TRPV1 and ASIC1a expression in spinal dorsal horn neurons.

The effect of morphine and naloxone on release of the excitatory amino acids (EAAs) of spinal astrocytes induced by TNF-α was studied. Astrocytes were purified from 2- to 3-day old SD rats and divided into 8 groups: group 1 (without any stimulatants); group 2 (10 ng/ml TNF-α);group3 (10 ng/ml TNF-α+0.5 μmol/L morphine); group 4 (10 ng/ml TNF-α+1. 0 μmol/L morphine); group 5 (10 ng/ml TNF-α+ 2. 0 μmol/L morphine) ; group 6 (10 ng/ml TNF-α+ 0. 5 μmol/L naloxone); group 7 (10 ng/ml TNF-α+ 1.0 μmol/L naloxone) ; group 8 (10 ng/ml TNF-α+2.0 μmol/L naloxone). In group 2, 3, 4 and 5, 0, 0.5, 1.0 or 2.0 μmol/Lmorphine was added to the cells cultured with serum-free Neurobasal/B27 medium containing 10 ng/ml TNF-α respec-tively, while in group 6, 7 and 8, 0.5, 1.0 or 2.0 μmol/Lnaloxone was added respectively to the cells cultured with serum-free Neurobasal/B27 medium containing 10 ng/ml TNF-α. After 30 min incubation, high-pressure liquid chromatography (HPLC) was used to measure the levels of EAAs in all cultured cells. The results showed the level of EAAs in group 2 was significant higher than in group 1 (P＜0.01). As compared with group 2, the levels of EAAs in group 3, 4 and 5 were decreased with the difference being significant between group 5 and group 2 (P＜0.01) or between group 4 and group 2 (P＜0.05). The levels of EAAs in group 6, 7 and group 8 was significantly lower than in group 2 (P＜0.05 or P＜0.01). It was concluded that TNF-α could promote the release of glutamate and aspartate from astrocytes, and morphine and naloxone might reduce the release of EAAs in cultured spinal astrocytes induced by TNF-α.

Objective To investigate the effects of propofol the expression of inducible nitric oxide synthase (iNOS) in the spinal cord in rats with chronic neuropathic pain. Methods Forty adult Wistar rats of both sexes weighing 200-220 g were used in this study. Chronic neuropathic pain was produced by loose ligatures placed on the left sciatic nerve. Propofol or normal saline (NS) was given intraperitoneally (i.p. ) once a day for 6 days, seven days after sciatic nerve ligation. The animals were randomly divided into 4 groups (n = 10) : group Ⅰreceived NS 50 ml?kg-1 i.p. but no sciatic nerve ligation; group Ⅱ received sciatic nerve ligation and NS 50 ml?kg-1 i.p. ; group Ⅲ and Ⅳ received sciatic nerve ligation and propofol 50ml?kg-1 (Ⅲ) or75ml?kg-1 (Ⅳ) i.p. . Withdrawal threshold of both hind paws to Von Frey filaments was measured on the 6th , 10th and 12th days after sciatic nerve ligation. The animals were then sacrificed and the lumbar segment (L4-5) of the spinal cord was removed for the detection of iNOS mRNA expression by RT-PCR technique on the 12th day. Results The withdrawal threshold to Von Frey filament of both hind paws was significantly higher on the 10th and 12th days in the two propofol groups (group Ⅲ and Ⅳ) than in group Ⅱ(P

Objective Glutarnic acid, an important excitatory neurotransmitter, plays an important role in morphine dependence and tolerance. Astrocyte (AST) takes up giutamic acid which is transformed into glutamine, the precursor of GABA, by means of intracellular glutaminase. The aim of thin study was to investigate the effect of ketamine on glutamate release in cultured spinal ASTs chronically treated with morphine. Methods ASTs were isolated from 1-3 day old SD rats and divided into 8 groups : control group and group A, B1, B2, B3 , C1, C2, C3. The isolated ASTs were cultured and incubated for 48h in the presence (group A, B1-3, C1-3) and absence (control group) of 10?mol?L-1 morphine.Then the ASTs were transferred to liquid culture medium Neurobasal / B27 containing no serum. No drug was added in group A. Morphine 0.1 ,1 or 10?mol?L-1 was added in group B1-3 and ketamine 0.4, 4 or 40?mol?L-1 in group C1-3. After being incubated for 15 min, naloxone 10?mol?L-1 was added in group B1-3 and C1-3. After another 30 min incubation the gluamate concentration in supernatant was measured using HPLC. Results There was no significant difference in glutamate concentration between control group and group A ( P

Objective Recent studies have shown that activation of spinal astrocytes (ASTs) may be involved in the development of morphine tolerance. The purpose of this study was to investigate the effect of ketamine (K) on spinal ASTs in mice tolerant to morphine (M) .Methods Thirty Kun-Ming mice of both sexes weighing 18-22 g were randomly divided into 5 groups of six animals each : (A) control group received only subcutaneous (s.c.) and intraperitoneal (i.p.) normal saline (NS); (B) chronic M-tolerance group received M 10 mg?kg-1 s.c. followed after 30 min by NS 10 ml?kg-1 i.p. twice a day (at 8:00 and 17:00) for 9 days;(C), (D), (E) K group received M 10 mg?kg-1 s.c. followed after 30 min by K 5 mg? kg-1(C), 10 mg?kg-1 (D) or 20 mg?kg-1 (E) i.p. twice a day for 9 days. Pain threshold was estimated by measuring paw withdrawal response to Von Frey filament stimulation every other day (1st, 3rd, 5th, 7th, 9th) In after second administration of drugs. The percentage of maximal possible effect (MPE% ) was calculated : MPE% = [ (test group PWTV - control group PWTV) / (15 - control group PWTV)] ? 100% (PWTV = paw withdrawal threshold value). On the 9th day after pain threshold was measured the animals were sacrificed and lumbosacral segment of spinal cord was removed. The changes in spinal ASTs were detected by immunohistochemistry. The average areas of GFAP immuno-reactive cells in the dorsal horn were measured to show the degree of spinal AST activation. Results 1. MPE% was 0 at all time points in group A. In group B MPE% was 42.8% on the 1st and 3rd day and gradually decreasing on the 5th and 7th day and became 0 on the 9th day signifying full development of morphine tolerance. In group C the change in MPE% was almost the same as in group B. In group D and E MPE % tended to decrease but was still above 30% at all time points signifying that ketamine 10 and 20 mg?kg-1 could partly antagonize the development of morphine tolerance. 2. In group B the staining of GFAP immuno-reactive cells was heavier and the average areas were significantly larger than in group A (P