Effect and mechanism of gastrodin inhibiting β-amyloid plaques in brain of mice / 药学学报

This study was designed to investigate the effect of gastrodin (GAS) against β-amyloid plaques in 5×FAD Alzheimer's disease (AD) transgenic mice, and utilize 117 cell model (over-expression of Aβ and β-secretase) to explore the underlying mechanism. 5×FAD mice model were randomly divided into three groups, including GAS-high dose group (GAS-H, 200 mg·kg-1·d-1), GAS-middle dose group (GAS-M, 100 mg·kg-1·d-1) and GAS-low dose group (GAS-L, 50 mg·kg-1·d-1). Meanwhile, the wild type mice were used in the control group. After being treated with GAS for three months, 5×FAD mice were evaluated by Morris water maze for the learning and memory ability and by ELISA for Aβ in the cerebral homogenate. Then, Aβplaques in the hippocampus and cortex of 5×FAD mice were observed and analyzed with immunohistochemical staining. The cell apoptosis rate and the cell viability were determined in vitro, after the cells were treated with different concentrations of GAS (10, 25, 50 and 100 μmol·L-1). Furthermore, Intracelluar/extracelluar Aβ were determined by ELISA. Effects of GAS on BACE (β-secretase site APP cleaving enzyme) mRNA and protein expression were analyzed in 117 cell models by Q-PCR and Western blotting. The results suggest that GAS is able to restore the learning and memory capacity of 5×FAD mice, and reduce Aβ in the cerebral homogenate and Aβ plaques in the brain. Compared with the untreated transgenic positive group, A β plaques were declined in hippocampus and cortex of GAS-H group by 93.28% and 88.88%, and A β was reduced in the cerebral homogenate by 55.74%. In vitro study suggests a dose-dependent effect of GAS in reducing Aβ in 117 cell models. When the cells were treated with 100 μmol·L-1 GAS, extracelluar Aβ and intracellular Aβ of 117 cells were reduced by 63.1% and 49.1%. BACE expression was largely suppressed in mRNA by 32.9% (P-1 GAS, the protein level was declined by 47.9% (Pβ production and accumulation by inhibiting β-secretase.

Screening of 10 types of Chinese herbal compounds inhibiting Abeta and their possible related mechanism in vitro / 药学学报

This study is to screen the Chinese herbal compounds which could inhibit the production of Abeta and investigate the underlying mechanism. Ten types of compounds which have potential value in the treatment of AD were selected as initial screening trial. The cell models which used could overexpress Abeta and beta-secretases or Abeta and gamma-secretases. Extracellular Abeta was determined by ELISA after the cell models treated with different concentrations of compounds (0.5-100 micromol x L(-1)), separately. Then the compounds were selected which could inhibit extracellular Abeta and their best concentration ranges were decided, too. Furthermore, the cell viability and apoptosis rate, the level of intracellular Abeta, beta and gamma-secretases were determined after the cell models treated with different concentrations of selected compounds. The results showed that 4 of the 10 compounds could reduce the level of extracellular Abeta; they were cryptotanshinone, astragalosides, gastrodin and paeoniflorin, and their best concentration ranges were 0.5-5.0, 0.5-5.0, 5.0-50, 1.0-25 micromol x L(-1), respectively. Further study indicated that the 4 selected compounds were nontoxic to the cellular models and lowering intracellular Abeta were more effective compared with extracellular; of which astragalosides and gastrodin showed dose-dependent inhibition to the activities of beta and gamma-secretases, with the maximum inhibiting rates of 78.2% and 80.3%, respectively. In conclusion, cryptotanshinone, astragalosides, gastrodin and paeoniflorin could inhibit the expression and secretion of Abeta, and the underlying inhibiting mechanism of astragalosides and gastrodin were related with the reduction of the beta and gamma-secretase activities, respectively.

Effect of thymidine phosphorylase cDNA transfection on the inhibition of human colon carcinoma cell line by 5'-deoxy-5-fluorouridine / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the inhibiting impact of 5'-deoxy-5-fluorouridine (5'-DFUR) on human colon carcinoma cell line LOVO after transfection of thymidine phosphorylase (TP) cDNA.</p><p><b>METHODS</b>TP cDNA was transfected into human colon carcinoma cell line LOVO with lentiviral vector pLenti6.3_MCS_IRES2-EGFP, and the transfection efficiency was analyzed by flow cytometry. TP mRNA and protein expressions were detected by RT-PCR and Western blotting respectively. The IC50 of 5'-DFUR on TP-transfected LOVO and parental cell were evaluated by MTT assay. The volumes of 5-FU converted from 5'-DFUR in media, where TP-transfected and parental LOVO were cultured, were detected by HPLC.</p><p><b>RESULTS</b>The stable transfectants passed 5 generations were obtained and the transfection rate was 95%. Compared with parental cell, the RQ values of mRNA expression in TP-transfected LOVO was (282.5±86.8) folds higher significantly (P<0.01), also the TP protein expression of TP-transfected LOVO was obviously up-regulated as compared to parental cells. The IC50 value of 5'-DFUR of TP-transfectants was (1087.7±89.1) μmol/L, less than (1607.3±56.8) μmol/L of parental cells significantly (P<0.01), while there was no significant difference between parental cells and vector-transfectants [(1699.5±38.7) μmol/L, P>0.05]. HPLC revealed that when medium was added with 0, 500, 1000, and 2000 μmol/L of 5'-DFUR respectively, 0, 2.10, 3.13, and 7.19 μmol/L of 5-FU was found in the parental cells culture, while 0, 22.16, 30.94 and 40.02 μmol/L of 5-FU was found in TP-transfectants culture, but no 5-FU was found in the vector-transfectants culture.</p><p><b>CONCLUSION</b>TP cDNA transfection into LOVO can up-regulate the TP mRNA and protein expressions, increase the 5-FU converted from 5'-DFUR, and enhance the cytotoxic effect of 5'-DFUR on the LOVO cells.</p>

Enhanced anticancer effects of 5'-DFUR on colorectal cancer cell lines SW480 and LOVO by transfection with thymidine phosphorylase cDNA / 中华外科杂志

<p><b>OBJECTIVES</b>To study the change of ability to transform from 5'-deoxy-fluorouracil monophosphate (5'-DFUR) to fluorouracil (5-FU) in human colon cancer cell lines SW480 and LOVO which transfected with thymidine phosphorylase (TP) gene. And to discuss the anti-cancer activity of 5'-DFUR to SW480 and LOVO cells.</p><p><b>METHODS</b>TP cDNA were transfected into human colorectal cancer cell lines SW480 and LOVO with the lentiviral vector, pLenti6.3_MCS_IRES2-EGFP. The transfection efficiency was analyzed by flow cytometer, the mRNA expression of TP was detected by RT-PCR, and the TP protein expression was detected by Western blot, and the volumes of 5-FU converted from 5'-DFUR both in 2 cells and medium were detected by high performance liquid chromatography (HPLC). The 50% inhibitory concentration (IC50) of 5'-DFUR on these 2 colon cancer cell lines both wild type and TP-transfected cells were evaluated by MTT assay.</p><p><b>RESULTS</b>The colorectal cancer cell lines SW480 and LOVO transfected with human TP cDNA were monitored 5 generations, and the transfections efficiency rate wea about 95%. Compared with wild type cell SW480 and LOVO, the RQ values of mRNA expression of SW480-TP and LOVO-TP were (695 ± 171) folds (t = -7.00, P = 0.002) and (282 ± 87) folds (t = -5.61, P = 0.030), respectively. Also TP protein expression in SW480-TP and LOVO-TP were higher than their parent cells shown by Western blot. The volume of 5-FU converted from 5'-DFUR in the medium cultured SW480-TP and LOVO-TP were increased compared with their parent cells, respectively (t = 19.406-66.921, P < 0.01), whereas few of 5-FU was detected both in wild, and TP-transfected cells. After transfected with TP cDNA, the IC50 of 5'-DFUR on SW480-TP and LOVO-TP were (587 ± 17) µmol/L and (1088 ± 89) µmol/L respectively, and there were significantly less than their parent cells (t = -32.59 and -8.52, P < 0.01).</p><p><b>CONCLUSIONS</b>The stabilized transfections of SW480 and LOVO with higher TP expression could be built with lentiviral vector. Transfected TP cDNA into SW480 and LOVO, could improve the expression both of TP mRNA and TP protein, increase the volume of 5-FU converted from 5'-DFUR in medium, and result in an enhancement of anticancer effect on these 2 cells.</p>

Influence of interferon-α2a on thymidine phosphorylase expression and anticancer activity of 5'-deoxy-fluorouridine in human colon carcinoma cell lines LOVO and SW480 / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To detect the effect of interferon-α2a(IFN-α2a) on thymidine phosphorylase(TP) mRNA expression levels and the anticancer activity of 5-fluorouracil(5-FU) and 5'-deoxy-fluorouridine(5'-DFUR) in human colon carcinoma cell lines LOVO and SW480.</p><p><b>METHODS</b>Two human colon cancer cell lines LOVO and SW480 were cultured and treated with IFN-α2a at a series of dosage, and fluorescence quantitative PCR was carried out to detect the TP mRNA expression levels in these 2 cell lines. Then MTT assay and software Templet were used to determine the change of 50% inhibition concentration of 5-FU or 5'-DFUR combined with IFN-α2a on the two cell lines.</p><p><b>RESULTS</b>The TP mRNA expressions were up-regulated significantly by IFN-α2a at the doses of 500 U/ml and 5000 U/ml in LOVO(P<0.01). Compared with untreated cells(IFN-α2a 0 U/ml), no significance was found for TP mRNA expression levels in LOVO and SW480 treated by IFN-α2a at the dose of 50 U/ml (P>0.05). There was no significant difference for TP mRNA expression in SW480 between the dose of 0 U/ml and 500 U/ml of IFN-α2a(P>0.05), while a significant increace was detected at the dose of 5000 U/ml (P<0.01). No significant difference was found for the IC50 values after treatment of 5-FU combined with IFN-α2a (20 U/ml) on LOVO and SW480 compared with 5-FU alone, while the IC50 values after treatment of 5'-DFUR combined with IFN-α2a decreased significantly compared with 5'-DFUR alone(P<0.05).</p><p><b>CONCLUSION</b>There is no direct inhibition effect of IFN-α2a on LOVO and SW480 in vitro, while it can up-regulate TP mRNA expression levels both in LOVO and SW480, and enhance the anticancer effect of 5'-DFUR on these 2 cell lines.</p>

Expression and clinical significance of fibroblast activation protein in colorectal carcinoma tissue / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To detect the expression of fibroblast activation protein(FAP) in colorectal cancer tissue, and to investigate the association between expression of FAP with pathological parameters.</p><p><b>METHODS</b>Fifty-five cancer tissues and 50 normal colorectal samples were examined using immunohistochemistry with anti-FAP polyclonal antibody. The distribution of positive cells in different tissues, and associations of positive cell number with tumor staging, lymph node metastasis and tumor invasion were investigated to evaluate the effects of FAP on pathological progress in colorectal cancer.</p><p><b>RESULTS</b>No FAP expression was observed in 50 normal colorectal tissue samples. FAP positive cells were seen in carcinoma associated fibroblasts(CAFs), and in few colorectal cancer cells. The numbers of FAP positive cells in tissue samples of TNM III(-IIII((40.1±15.9) was significantly greater than that of TNMI(-II( (18.3±7.7)(P<0.01). Furthermore, the number of FAP positive cells in tissue samples with lymph node metastasis (44.4±13.3) was also significantly higher than those without lymph node metastasis (18.5±8.1)(P<0.01). Significant positive correlations were found between the number of FAP-positive cells with the tumor TNM staging and lymph node metastasis(r=0.544 and r=0.793, respectively)(P<0.01). The number of FAP-positive cells was 25.2±8.9 in T2, 32.41±19.30 in T3, and 29.2±16.5 in T4. The association between number of positive cells and depth of invasion was not statistically significant(P>0.05).</p><p><b>CONCLUSIONS</b>The FAP mainly expresses in CAFs locating in colorectal cancer tissues. The number of FAP positive cells is positively correlated with TNM staging of colorectal cancer and lymph node metastasis.</p>

Study on expression of PS1 in APP-PS1 double gene stably transfected cell lines and its relation to gamma-secretase / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the role of presenilin1 (PS1) in the processing of beta-amyloid precursor protein (APP) to amyloid beta-peptide (Abeta) and its relation to gamma-secretase in the pathogenesis of Alzheimer's disease (AD).</p><p><b>METHODS</b>Several CHO cell lines stably transfected with either wide-type or mutant PS1 (M(146)L) along with APP(751) genes were established. The expression of PS1 and its half-life were determined by immunoprecipitation, Western blotting and pulse-chase experiment. Abeta released into the conditional media was quantitated by ELISA.</p><p><b>RESULTS</b>PS1 transfected CHO cells expressed an expected 45,000 full length protein. This over-expressed full length PS1 was subject to fast degradation with a half-life of less than 1 hour. In contrast to full length PS1, the truncated N-terminal and C-terminal proteins of PS1 were significantly more stable with a longer half-life of nearly 16 hours. Although the total amount of Abeta released into the conditional media did not show a significant difference between wild-type and mutant PS1 (M(146)L) transfected APP cells, mutant PS1 (M(146)L) transfected APP cells increase Abeta(1 - 42) (a subspecies of total Abeta) production with nearly a 2 fold increase, comparing to untransfected or wild-type PS1 transfected APP cells.</p><p><b>CONCLUSION</b>PS1 is involved in the processing of APP to Abeta, a nearly 2 fold increase of Abeta production in mutant PS1 (M(146)L) transfected APP cells indicates that PS1 may be the expected gamma-secretase itself.</p>