OBJECTIVE: Cassiae Semen (CS, Juemingzi in Chinese) has been used for thousands of years in ancient Chinese history for relieving constipation, improving liver function as well as preventing myopia. Here we aimed to elucidate the anti-steatosis effect and underlying mechanism of CS against non-alcoholic fatty liver disease (NAFLD). METHODS: High-performance liquid chromatography (HPLC) was used to identify the major components of CS water extract. Mice were fed with a high-fat and sugar-water (HFSW) diet to induce hepatic steatosis and then treated with CS. The anti-NAFLD effect was determined by measuring serum biomarkers and histopathology staining. Additionally, the effects of CS on cell viability and lipid metabolism in oleic acid and palmitic acid (OAPA)-treated HepG2 cells were measured. The expression of essential genes and proteins involved in lipid metabolism and autophagy signalings were measured to uncover the underlying mechanism. RESULTS: Five compounds, including aurantio-obtusin, rubrofusarin gentiobioside, cassiaside C, emodin and rhein were simultaneously identified in CS extract. CS not only improved the diet-induced hepatic steatosis in vivo, as indicated by decreased number and size of lipid droplets, hepatic and serum triglycerides (TG) levels, but also markedly attenuated the OAPA-induced lipid accumulation in hepatocytes. These lipid-lowering effects induced by CS were largely dependent on the inhibition of fatty acid synthase (FASN) and the activation of autophagy-related signaling, including AMP-activated protein kinase (AMPK), light chain 3-II (LC3-II)/ LC3-1 and autophagy-related gene5 (ATG5). CONCLUSION Our study suggested that CS effectively protected liver steatosis via decreasing FASN-related fatty acid synthesis and activating AMPK-mediated autophagy, which might become a promising therapeutic strategy for relieving NAFLD.

Objective:To investigate the clinical efficacy and prognostic influencing factors of radical surgery for duodenal gastrointestinal stromal tumor (GIST).Methods:The retrospective cohort study was conducted. The clinicopathological data of 741 duodenal GIST patients who under-went radical surgery in 17 medical centers, including 121 cases in Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 121 cases in Chinese PLA General Hospital, 116 cases in Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 77 cases in Fudan University Shanghai Cancer Center, 77 cases in West China Hospital, Sichuan University, 31 cases in Guangdong Provincial People′s Hospital, 24 cases in Fujian Cancer Hospital, 22 cases in Fujian Medical University Union Hospital, 25 cases in Shengjing Hospital of China Medical University, 19 cases in Xiangya Hospital, Central South University, 23 cases in Zhejiang Cancer Hospital, 17 cases in Liaoning Cancer Hospital＆Institute, 17 cases in the First Affiliated Hospital of Xiamen University, 15 cases in Sun Yat-sen University Cancer Center, 14 cases in the First Affiliated Hospital of Nanjing Medical University, 14 cases in Zhongshan Hospital Affiliated to Xiamen University and 8 cases in General Hospital of Chinese People′s Liberation Army Air Force, from January 2010 to April 2020 were collected. There were 346 males and 395 females, aged 55(range, 17?86)years. Observation indicators: (1) neoadjuvant treatment; (2) surgical and postoperative situations; (3) follow-up; (4) stratified analysis. Follow-up was conducted using outpatient examination or telephone interview. Patients were followed up once every 3?6 months during neoadjuvant therapy and once every 6?12 months after radical surgery to detect tumor recurrence and survival of patient up to April 2022. Measurement data with normal distribution were represented as Mean± SD. Measurement data with skewed distribution were represented as M(range), and comparison between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using chi-square test or Fisher exact probability. The Kaplan-Meier method was used to draw survival curves and calculate survival rates. Log-rank test was used for survival analysis. The COX regression model was used for univariate and multivariate analyses. Propensity score matching was done by the 1∶1 nearest neighbor matching method, and the matching tolerance was 0.02. Results:(1) Neoadjuvant therapy. Of the 741 patients, 34 cases received neoadjuvant therapy for 8(range, 3?44)months. Cases assessed as partial response, stable disease and progressive disease before the radical surgery of the 34 cases were 21, 9, 4, respectively. The tumor diameter of the 34 patients before the neoadjuvant therapy and before the radical surgery were 8.0(range, 3.0?26.0)cm and 5.3(range, 3.0?18.0)cm, with the regression rate as 31.9%(range, ?166.7% to 58.3%). (2) Surgical and postoperative situations. Of the 741 patients, 34 cases underwent radical surgery after receiving neoadjuvant therapy, and 707 cases underwent radical surgery directly. All the 741 patients underwent radical surgery successfully, in which 633, 102 and 6 cases received open surgery, laparoscopic surgery and endoscopic treatment, respectively. Of the 633 cases receiving open surgery and the 102 cases receiving laparoscopic surgery, cases with surgical resection range as pancreatoduodenectomy (PD) was 238, and cases with surgical resection range as duodenal limited resection, including duodenal wedge resection, distal gastrectomy, segmental duodenal resection, local resection of duodenal tumor or segmental duodenum combined with subtotal gastrectomy, was 497, 226, 55, 204, 12. Of the 741 patients, 131 cases had post-operative complications including 113 cases with grade Ⅰ?Ⅱ complications and 18 cases with ≥ grade Ⅲ complications of the Clavien-Dindo classification. The duration of postoperative hospital stay of the 741 patients was 13(range, 4?120)days. Of the 707 patients receiving direct radical surgery, 371 cases were evaluated as extremely low risk, low risk, medium risk of the modified National Institutes of Health (NIH) risk classification after surgery, and 336 cases were evaluated as high risk in which 205 cases receive postoperative adjuvant imatinib therapy with the treatment time as 24(range, 6?110)months. (3) Follow-up. All the 741 patients were followed up for 58(range, 7?150)months. During the follow-up, 110 patients had tumor recurrence and metastasis. The 1-, 3-, 5-year overall survival rates and 1-, 3-, 5-year disease-free survival rates of the 741 patients were 100.0%, 98.6%, 94.5% and 98.4%, 90.9%, 84.9%, respectively. The 1-, 3-, 5-year overall survival rates and 1-, 3-, 5-year disease-free survival rates of the 707 patients receiving direct radical surgery were 100.0%, 98.5%, 94.3% and 98.4%, 91.1%, 85.4%, respectively. (4) Stratified analysis. ① Analysis of prognostic factors in patients undergoing radical surgery directly. Results of univariate analysis showed that primary tumor location, tumor diameter, mitotic count, modified NIH risk classification and tumor gene information were related factors affecting the overall survival of 707 patients with primary duodenal GIST who underwent direct radical surgery ( hazard ratio=0.43, 0.18, 0.22, 0.06, 0.29, 95% confidence intervals as 0.20?0.93, 0.09?0.35, 0.10?0.50, 0.03?0.12, 0.09?0.95, P<0.05). The primary tumor location, tumor diameter, mitotic count, modified NIH risk classification were related factors affecting the disease-free survival of 707 patients with primary duodenal GIST who underwent direct radical surgery ( hazard ratio=0.65, 0.25, 0.25, 0.10, 95% confidence intervals as 0.41?1.03, 0.17?0.37, 0.15?0.42, 0.07?0.15, P<0.05). Results of multivariate analysis showed that primary tumor located at the horizontal segment of duodenum, mitotic count >5/50 high power field, tumor gene KIT exon 9 mutation were independent risk factors affecting the overall survival of 365 patients with primary duodenal GIST after removing 342 patients without tumor gene information who underwent direct radical surgery ( hazard ratio=2.85, 2.73, 3.13, 95% confidence intervals as 1.12?7.20, 1.07?6.94, 1.23?7.93, P<0.05). Tumor diameter >5 cm and mitotic count >5/50 high power field were independent risk factors affecting the disease-free survival of 707 patients with primary duodenal GIST who underwent direct radical surgery ( hazard ratio=3.19, 2.98, 95% confidence intervals as 2.05?4.97, 1.99?4.45, P<0.05). ② Effect of postoperative adjuvant therapy on prognosis of high-risk patients of modified NIH risk classification. Of the 336 patients evaluated as high risk of the modified NIH risk classification, the 5-year overall survival rate and 5-year disease-free survival rate were 94.6% and 77.3% in the 205 cases with postoperative adjuvant therapy, versus 83.2% and 64.4% in the 131 cases without postoperative adjuvant therapy, showing significant differences between them ( χ2=8.39, 4.44, P<0.05). Of the 205 patients evaluated as high risk of the modified NIH risk classification who received postoperative adjuvant therapy, there were 106 cases receiving postoperative adjuvant therapy <36 months, with the 5-year overall survival rate and 5-year disease-free survival rate were 87.1% and 58.7%, and there were 99 cases receiving post-operative adjuvant therapy ≥36 months, with the 5-year overall survival rate and 5-year disease-free survival rate were 100.0% and 91.5%. There were significant differences in the 5-year overall survival rate and 5-year disease-free survival rate between the 106 patients and the 99 patients ( χ2=13.92, 29.61, P<0.05). ③ Comparison of clinical efficacy of patients with different surgical methods. Before propensity score matching, cases with primary tumor located at bulb, descending, horizontal, ascending segment of duodenum, cases with tumor diameter ≤5 cm and >5 cm were 95, 307, 147, 34, 331, 252, in the 583 patients receiving open surgery with complete clinical data, versus 15, 46, 17, 5, 67, 16 in the 83 patients receiving laparoscopic surgery with complete clinical data, showing no significant difference in the primary tumor location ( χ2=0.94, P>0.05), and a significant difference in the tumor diameter ( χ2=17.33, P<0.05) between them. After propensity score matching, the above indicator were 16, 39, 20, 8, 67, 16 in the 83 patients receiving open surgery, versus 15, 46, 17, 5, 67, 16 in the 83 patients receiving laparoscopic surgery, showing no significant difference between them ( χ2=1.54, 0.00, P>0.05). Cases with postoperative complications, cases with grade Ⅰ?Ⅱ complica-tions and ≥grade Ⅲ complications of the Clavien-Dindo classification, duration of postoperative hospital stay, the 5-year overall survival rate and 5-year disease-free survival rate were 17, 12, 5, 11(range, 5?120)days, 92.0%, 100.0% in the 83 patients receiving open surgery, versus 9, 7, 2, 11(range, 5?41)days, 91.6%, 97.3% in the 83 patients receiving laparoscopic surgery, showing no signi-ficant difference in postoperative complications, duration of postoperative hospital stay, the 5-year overall survival rate and 5-year disease-free survival rate ( χ2=2.91, Z=3 365.50, χ2=3.02, 1.49, P>0.05) between them. There was no significant difference in complications of the Clavien-Dindo classification between them ( P>0.05). ④ Comparison of clinical efficacy of patients with primary tumor located at the descending segment of duodenum who underwent surgery with different surgical resection scopes. Before propensity score matching, cases with tumor diameter ≤5 cm and >5 cm, cases with tumor located at opposite side of mesangium and mesangium were 71, 85, 28, 128 in the 156 patients with primary tumor located at the descending segment of duodenum who underwent PD with complete clinical data, versus 92, 41, 120, 13 in the 133 patients with primary tumor located at the descending segment of duodenum who underwent duodenal limited resection with complete clinical data, showing significant differences between them ( χ2=16.34, 150.10, P<0.05). After propensity score matching, the above indicator were 28, 13, 16, 25 in the 41 patients with primary tumor located at the descending segment of duodenum who underwent PD with complete clinical data, versus 28, 13, 16, 25 in the 41 patients with primary tumor located at the descending segment of duodenum who underwent duodenal limited resection with complete clinical data, showing no significant difference between them ( χ2=0.00, 0.00, P>0.05). Cases with postopera-tive complications, cases with grade Ⅰ?Ⅱ complications and ≥grade Ⅲ compli-cations of the Clavien-Dindo classification, duration of postoperative hospital stay, the 5-year overall survival rate and 5-year disease-free survival rate were 13, 11, 2, 15(range, 9?62)days, 94.2%, 64.3% in the 41 patients with primary tumor located at the descending segment of duodenum who underwent PD with complete clinical data, versus 9, 8, 0, 15(range, 7?40)days, 100.0%, 78.8% in the 41 patients with primary tumor located at the descending segment of duodenum who underwent duodenal limited resection with complete clinical data, showing no significant difference in post-operative complica-tions, the 5-year overall survival rate and 5-year disease-free survival rate ( χ2=0.99, 0.34, 1.86, P>0.05) between them. There was no significant difference in complications of the Clavien-Dindo classification ( P>0.05) and there was a significant difference in duration of postopera-tive hospital stay ( Z=614.50, P<0.05) between them. Conclusions:The clinical efficacy of radical surgery for duodenal GIST are ideal. Primary tumor located at the horizontal segment of duodenum, mitotic count >5/50 high power field, tumor gene KIT exon 9 mutation are independent risk factors affec-ting the overall survival of patients undergoing direct radical surgery and tumor diameter >5 cm and mitotic count >5/50 high power field are independent risk factors affecting the disease-free survival of patients. There is no significant difference in the short-term efficacy and long-term prognosis between patients undergoing open surgery and laparoscopic surgery. For patients with primary tumor located at the descending segment of duodenum, the duration of postoperative hospital stay is longer in patients undergoing PD compared with patients undergoing duodenal limited resection. For patients evaluated as high risk of the modified NIH risk classification, posto-perative adjuvant therapy and treatment time ≥36 months are conducive to improving the prognosis of patients.

OBJECTIVE:To study the effects of 3 extracts of Acanthopanax sessiliflorus fruits on the proliferation and apoptosis of human hepatocarcinoma cells SMMC-7721,and to provide reference for confirming the mechanism of anti-tumor effect. METHODS:MTT assay was adopted to investigate the effects of low-mass concentration,medium-mass concentration and high-mass concentration of ethanol extract(0.92,1.84,3.68 mg/mL),crude polysaccharide extract(0.06,0.12,0.24 mg/mL)and refined polysaccharide extract (0.04, 0.08, 0.16 mg/mL) from A. sessiliflorus fruits on the proliferation and apoptosis of SMMC-7721 cells after treated for 24,36,48 h,respectively. Flow cytometry was used to investigate the effects of 1.84 mg/mL ethanol extract,0.24 mg/mL crude polysaccharide extract and 0.16 mg/mL refined polysaccharide extract on cell cycle and cell apoptosis after treated for 24 h. The above tests were all negative control(only adding cells without drugs). RESULTS:Compared with negative control,3 extracts of A. sessiliflorus fruits could significantly inhibit the proliferation of SMMC-7721 cells (P<0.01),could significantly decrease the percentage of SMMC-7721 cells in G0/G1 and G2/M phase(P<0.01),could significantly increase the percentage of SMMC-7721 cells in S phase (P<0.01) and the apoptosis rate of SMMC-7721 cells (P<0.05);especially the effects of ethanol extract from A. sessiliflorus fruits were the most obvious. CONCLUSIONS:Three extracts of A.sessiliflorus fruits can inhibit the proliferation of human hepatocarcinoma SMMC-7721 cells,block SMMC-7721 cells in S phase and induce the apoptosis of SMMC-7721 cells.

Objective To analyze the dTP value in the patients with coronary heart disease (CHD) complicating diabetes mellitus (DM) and its relationship with major adverse cardiovascular events (MACE) and rehospitalization.Methods Two hundreds and seventy CHD patients were selected as the research subjects,including 136 cases of non-MD and 134 cases of DM.Their clinical condition was recorded.The indicators such as height,body mass,blood pressure and heart rate were measured.ECG,echocardiography,coronary angiography and other examiantions were carried out.The various indicators were detected.11-dh-TXB2 and 6-k-PGF1a levels were detected in the two groups and then dTP value was calculated.The 1-year follow-up was performed,MACE and rehospitalization were recorded.Epdate software was used for building a database and SPSS 17.0 software was applied for conducting the statistical analysis.Results The dTP level in the f non-DM and DM patients were 1.8 ± 0.6 and 2.0 ± 0.7 respectively,the difference was statistically significant (P＜ 0.05).For the non-DM CHD group,hs-CRP,systolic blood pressure,diastolic pressure,lesions number and severe lesions number were correlated with dTP level(P＜0.05).For the complicating DM CHD group,hs CRP,blood glucose,CHO level,lesions number and severe lesions number were correlated with dTP level(P＜0.05).After 1-year follow-up,MACE had 33 cases (24.3％) in the non-DM group and 44 cases (32.8％) in the DM group respectively,the difference was not statistically significant (P＞0.05).The rehospitalized cases had 12 cases (8.8％) in the non-DM group and 24 cases (17.9 ％).in the DM group respectively,the difference was statistically significant (P＜ 0.05).The dTP levels of MACE occurrence and non-MACE occurrence were 2.3 ± 0.8 and 1.8 ± 0.6 respectively,the difference was statistically significant (P＜0.05).The dTP levels of rehospitalized patients and non-rehospitalized patients were 2.4 ± 1.0 and 1.9 ±-0.6 respectively,the difference was statistically significant(P＜0.05).Conclusion The dTP level in the patients with CHD complicating DM is significantly increased,suggesting that platelet is obviously activated,moreover higher dTP level increases the risk of MACE and rehospitalization.So the anti-platelet therapy should be strengthened.

Objective To analyze Clopidogrel Resistance (CR) and influencing factors of coronary heart disease (CHD) with diabetes (DM) patients and evaluatc the relationship of CR and major adverse cardiovascular events (MACE) and readmission of CHD with DM patients.Methods 270 CHD patients were enrolled.Clinical conditions of CR were measured by adenosine diphosphate (ADP) induced maximum platelet aggregation rate (MPAR).After 1-year follow-up,MACE events and rehospitalization were recorded.Results CR of NDM and DM patients were 45 (33.1％) and 78 cases (58.2％) respectively,and the difference was significant (P ＜ 0.001).Factors of CR of CHD DM patients included heart rate,TG level,the number of severe coronary artery disease.MACE events of CS and CR patients were 35 (23.8％) and 47 patients (38.2％) respectively,and the difference was significant (P =0.010).The readmitted patients of CS and CR groups were 15 cases (10.2％) and 27 patients (22.0％) respectively,and the differcnce was significant (P =0.008).The MACE of CR and CS patients in DM group were 32 (41.0％) and 12 cases (21.4％) respectively,and thc difference was significant (P ＜ 0.05).The Readmitted cases of CR and CS patients in DM group were 19 (24.4％) and 5 (8.9％) respectively,and the diffcrcnce was significant (P ＜ 0.05).Conclusions CR of CHD DM patients increased significantly.The influencing factors of CR of CHDDM are including heart rate,TG level,the number of severe coronary artery disease.MACE events and rehospitalization rate were significantly increased in CHD patients with DM AR.Therefore,it should be further strengthened the anti-platelet therapy for CHD patients with DM.

Objective To study the anti-depressant effect and mechanism of Peiyuan Jieyu Fang (Tonifying-original Qi Releasing-depression Formula).Methods The reserpine depression model was established by intraperitoneal injection of reserpine (2.5 mg/kg) in mice,acute stress depression model,by forced swimming test (FST) in mice,and chronic stress depression model,by long-term bandage (14 d) and noise in mice.The influences of Peiyuan Jieyu Fang on body temperature,ptosis and rate of overstepping bound in reserpine depression model,and on immobility time of FST in acute stress depression model and chronic stress depression model were observed.The content of brain 5-hydroxytryptamine (5-HT),noradrenalin (NA) and indoleamine-2,3-dioxygenase (IDO) in acute stress depression model,and content of 5-HT and IDO in chronic stress depression model were detected by using enzyme-linked immunosorbent assay (ELISA).The expression of IDO mRNA was detected by using fluorescence quantitative polymerase chain reaction (PCR) in chronic stress depression model.Results The decrease of body temperature was antagonized in all Peiyuan Jieyu Fang groups (abbreviated as high-dose group,mid-dose group and low-dose group) in reserpine depression model (P ＜ 0.01).The ptosis and akinesia induced by reserpine were relieved in high-dose group (P ＜ 0.05),and akinesia was relieved in low-dose group (P ＜ 0.05).The immobility time of FST was shortened (P ＜ 0.05,P ＜ 0.01),and content of 5-HT and NA were significantly increased in acute stress depression model in mid-dose group and low-dose group (P ＜0.05,P ＜0.01).The immobility time of FST was shortened in varying degrees,content of 5-HT was increased,content of IDO was decreased and IDO mRNA expression was up-regulated in chronic stress depression model in high-dose group,mid-dose group and low-dose group (P ＜ 0.05).Conclusion Peiyuan Jieyu Fang has some relief effects on depression symptoms induced by reserpine,FST and chronic stress in mice.The mechanism may be related to that Peiyuan Jieyu Fang can increase the content of 5-HT and NA,inhibit IDO activity,and down-regulate IDO mRNA expression.

Objective:To screen the peptide binding to human bladder carcinoma cells specifically by using phage display technology in vivo.Methods: Nude mice were inoculated with bladder carcinoma cells BIU87 for establishing tumor-bearing mice model.The Ph.D.-C7CTM Peptide Library was injected intravenously via tail vein.Then we screened Phage containing exogenous peptides binding to bladder transitional carcinoma cells specifically.The phage peptide homed to the tumor tissues was obtained after 3 rounds screening in vivo.The phage clones affinity to BIU87 were identified by immunohistochemistry and ELISA.The positive peptide was synthetized by chemical methods after sequencing the positive monoclonal phage DNA.The tumor cell specificity of target peptide was identified by confocal laser scanning microscope and flow cytometry.Results:After 3 rounds screening in vivo,enrichment rate of phage was 4.334×102 times.Immunohistochemistry results showed that the dyeing of the tumor tissue had a rising trend following each round of phage screening,while liver had a lot of non-specific binding phage because the phages were metabolized through liver and kid-ney.The 30 phage clones were identified by ELISA and 10 clones had a strong affinity on BIU87 among 24 positive clones.Three amino acid sequences of positive phage clones were obtained.The highest rate of repeat sequences CSSPIGRHC(8/10) named NYZL1 and the FITC-C6-NYZL1 peptide was synthesized.Our results showed that it could bind to bladder carcinoma cells BIU87 specifically.Conclusion:We obtained the small molecular peptide NYZL1 binding to human bladder carcinoma specifically by means of phage display in vivo,which provide a theoretical basis for bladder carcinoma early diagnosis and targeted therapy.

Objective To investigate the characters and targeted ability of FITC-CSNRDARRC molecular probe in labeling orthotopic transplantation tumor of bladder cancer in vivo.Methods From July 2013 to June 2014,the stability and characters of FITC-CSNRDARRC molecular probe were detected by spectrophotometer and molecular imaging and the optimum concentration and imaging time window were determined.30 BALB-C nude mice were randomly divided into experimental group (n =20) and control group(n =10).In control group,5 of them (group A) were ligated bilateral ureter,others(group B) were not.We established orthotropic transplanted bladder tumor (BIU-87) model by operation.And 0.2 ml probes (220 μmol/L) was then injected intravenously in all mice after 2 weeks.We obtained images and analyzed average gray value of the heart,lung,liver,spleen,bilateral kidney and orthotropic transplantation bladder tumor by using optical probe molecule fluorescence imaging system after 30 min,1 h,2 h,4 h and 12 h,respectively.Results After injected the FITC-CSNRDARRC molecular probes intravenously at 220 μmol/L,the fluorescence signal of tumor tissue strengthened gradually.The optimal imaging time window was 4 hours after injection.The illumination and temperature had little effect on the fluorescence signal.With the time passing after injection,the intensity of florescence signal progressively increasing,which reached the peak at4 h.The average gray value of tumor tissue at 1 h,2 h,3 h,4 h,5 h,6 h,8 h,12 h were 74.22,76.2,80.11,89.38,83.29,85.1,81.22,83.01,respectively.The fluorescence signal of normal tissue weakened gradually with the passage of time.Only liver and gall bladder could notice the fluorescence signal 4 hours after injection in group A.However,the relatively strong fluorescence signal could be found in liver and gall bladder in group B.Conclusions The characters of fluorescence probe are affected by its concentration.Its optimal concentration of labeling tumor is 220 μmol/L.The optical imaging time window was about 4 h after intravenous injection.The FITC-CSNRDARRC molecular probe can specifically bound to orthotopic transplanted tumor of bladder cancer in vivo.

The changes of glycogen synthase kinase-3(GSK-3)and protein phosphatase-2A(PP-2A),and the role of them in the regulation of the abnormally hyperphosphorylated some sites of tau in the cortex of diabetic rat were investigated.The diabetic rat model was induced by streptozotocin.The activities of GSK-3,PP-2A were measured by liquid scintillation for incorporated radioactivity in control,DM,DM + Li2CO3 groups.The level of hyperphosphorylated tau and the expression of 2PP-2A was measured respectively by Western blot.It is suggested that GSK-3 activity increases,PP-2A activity and expression decrease,and hyperphosphorylated tau be produced at Ser198/Ser199/Ser202 and Ser396/Ser404 in DM rats cortex.After the DM rat were treated with Li2CO3,the inhibition of GSK-3 activity and the improvement of PP-2A activity were found,and hyperphosphorylation of tau at Ser198/Ser199/Ser202 and Ser396/Ser404 were deduced.These studies firstly suggested that an increase of GSK-3 activity might inhibit PP-2A activity,and which produce hyperphosphorylated of tau at Ser198/Ser199/Ser202 and Ser396/Ser404 in DM rat cortex in common.

OBJECTIVETo explore the association between the abnormal phosphorylation sites found in Alzheimer disease (AD) tau and the inhibition of its biological activity.

METHODSUltracentrifugation, chromatography, manual Edman degradation and autosequence techniques were used to prepare and phosphorylate human recombinant tau, isolate and purify 32P tau peptides and determine phosphorylation sites.

RESULTSPhosphorylation of tau by casein kinase 1 (CK-1), cyclic AMP-dependent protein kinase (PKA) and glycogen synthetase kinase 3 (GSK-3) separately inhibited its biological activity and the inhibition of this activity by (CSK-3 was significantly increased if tau was prephosphorylated by CK-1 or PKA. The most potent inhibition was seen by a combined phosphorylation of tau with PKA and GSK-3. The treatment of tau by PKA and GSK-3 combination induced phosphorylation of tau at Ser-195, Ser-198, Ser-199, Ser-202, Thr-205, Thr-231, Ser-235, Ser-262, Ser-356, Ser-404, whereas Thr-181, Ser-184, Ser-262, Ser-356 and Ser-400 were phosphorylated by GSK-3 alone under the same condition.

CONCLUSIONPhosphorylation of tau by PKA plus GSK-3 at Thr-205 might play a key role in tau pathology in AD.

Alzheimer Disease ; metabolism ; Binding Sites ; Casein Kinases ; Cyclic AMP-Dependent Protein Kinases ; metabolism ; Glycogen Synthase Kinase 3 ; metabolism ; Humans ; In Vitro Techniques ; Microtubules ; metabolism ; Phosphorylation ; Protein Kinases ; metabolism ; tau Proteins ; metabolism