Ghrelin regulates insulin resistance by targeting insulin-like growth factor-1 receptor via miR-455-5p in hepatic cells

Objective: To explore the mechanism by which ghrelin regulates insulin sensitivity through modulation of miR-455-5p in hepatic cells. Methods: HepG2 cells were treated with or without DAG (1 μM). Glucose consumption, intracellular glycogen content, phosphorylation of PI3K and Akt stimulated by insulin, expression of miR-455-5p, as well as IGF-1R protein level were analyzed. In addition, bioinformatic analysis, dual luciferase reporter assay, miR- 455-5p mimic or inhibitor treatment was conducted to investigate the molecular mechanisms. Results: High glucose treatment upregulated miR-455-5p expression but reduced glucose consumption and glycogen content. DAG reversed the effect of high glucose on glucose metabolism, increased protein level of IGF-1R and phosphorylation of PI3K/Akt stimulated by insulin, as well as downregulated miR-455-5p expression. Bioinformatic analysis indicated IGF-1R was the target of miR-455-5p. Dual luciferase reporter assay, as well as transfection with miR-455-5p mimic/inhibitor confirmed that DAG activated IGF-1R/PI3K/Akt signaling via inhibiting miR-455-5p. Conclusion: DAG improves insulin resistance via miR-455-5p- mediated activation of IGF-1R/PI3K/Akt system, suggesting that suppression of miR-455-5p or activation of DAG may be potential targets for T2DM therapy.

三氧化二砷联合普纳替尼对白血病细胞KG-1的抑制效应

目的:探讨小分子酪氨酸激酶抑制剂普纳替尼联合三氧化二砷(arsenic trioxide,ATO)对人急性髓系白血病细胞KG-1的作用及可能机制。方法:CCK-8法检测普纳替尼及ATO对KG-1细胞增殖的影响;流式细胞术AnnexinⅤ/PI双重染色法检测细胞凋亡;实时荧光定量PCR检测细胞凋亡相关基因的表达;Western blot检测凋亡相关蛋白、成纤维细胞生长因子受体1(fibroblast growth factor receptor 1,FGFR1)蛋白及信号通路分子磷酸化水平的表达变化。结果:(1)ATO及普纳替尼对KG-1细胞的增殖抑制作用呈剂量依赖性,两药联合较单药作用具有更高的增殖抑制率、更少的集落形成及更多的细胞凋亡,差异均有统计学意义。(2)与DMSO组相比,ATO或普纳替尼均能显著下调Bcl-2表达,上调Bax及Caspase-3表达(P均<0.05);与单药作用相比,联合用药促进Bax及Caspase-3表达的作用更强(P均<0.01)。(3)普纳替尼显著抑制FGFR1基因及蛋白的表达(P均<0.01),ATO的加入并未使FGFR1表达进一步下降。信号通路研究显示,ATO可以显著抑制m-TOR和MAPK、STAT5的磷酸化(P均<0.001),但对PI3K/AKT、STAT3的磷酸化无明显影响。普纳替尼可以显著抑制FGFR1蛋白表达及STAT3、STAT5的磷酸化(P均<0.001),但对PI3K/AKT及MAPK的磷酸化无明显影响。两药联合后,STAT3的磷酸化水平较ATO或普纳替尼单药组进一步下调(P均<0.01)。结论:普纳替尼及ATO可能通过不同机制抑制KG-1细胞增殖及集落形成并诱导细胞凋亡;两药联合可进一步增强对KG-1细胞株的抑制效应。

蛋白激酶全抑制分析揭示KG-1细胞增殖的分子机制

目的:通过分析KG-1细胞对各种蛋白激酶抑制剂的反应,探讨其增殖的分子机制。方法:采用CCK-8法、实时荧光定量PCR(qRT-PCR)和Western-blot检测各种蛋白激酶抑制剂对KG-1细胞增殖、相关基因mRNA表达水平以及FGFR1下游信号通路蛋白磷酸化水平的影响。结果:NVP-BGJ398和PD173074有效抑制KG-1细胞的增殖,表明FGFR及其下游信号通路在KG-1细胞增殖过程中具有关键作用。使用FGFR抑制剂处理后,p-FGFR1和p-STAT5水平显著下降(P<0.001),p-Akt水平稍有下降(P<0.05),并未影响p-ERK水平(P>0.05)。结论:FGFR1OP2-FGFR1主要作用于下游STAT5信号通路,以促进细胞增殖。蛋白激酶全抑制分析是一种可靠而直接的方法,可用于确定癌细胞增殖的分子机制。

MiR-142-3p Regulates ILC1s by Targeting HMGB1 via the NF-κB Pathway in a Mouse Model of Early Pregnancy Loss

Objective Innate lymphoid cells(ILCs)are a class of newly discovered immunocytes.Group 1 ILCs(ILC1s)are identified in the decidua of humans and mice.High mobility group box 1(HMGB1)is predicted to be one of the target genes of miR-142-3p,which is closely related to pregnancy-related diseases.Furthermore,miR-142-3p and HMGB1 are involved in regulating the NF-κB signaling pathway.This study aimed to examine the regulatory effect of miR-142-3p on ILC1s and the underlying mechanism involving HMGB1 and the NF-κB signaling pathway.Methods Mouse models of normal pregnancy and abortion were constructed,and the alterations of ILC1s,miR-142-3p,ILC1 transcription factor(T-bet),and pro-inflammatory cytokines of ILC1s(TNF-α,IFN-γand IL-2)were detected in mice from different groups.The targeting regulation of HMGB1 by miR-142-3p in ILC1s,and the expression of HMGB1 in normal pregnant mice and abortive mice were investigated.In addition,the regulatory effects of miR-142-3p and HMGB1 on ILC1s were detected in vitro by CCK-8,Annexin-V/PI,ELISA,and RT-PCR,respectively.Furthermore,changes of the NF-κB signaling pathway in ILC1s were examined in the different groups.For the in vivo studies,miR-142-3p-Agomir was injected in the uterus of abortive mice to evaluate the abortion rate and alterations of ILC1s at the maternal-fetal interface,and further detect the expression of HMGB1,pro-inflammatory cytokines,and the NF-κB signaling pathway.Results The number of ILC1s was significantly increased,the level of HMGB1 was significantly upregulated,and that of miR-142-3p was considerably downregulated in the abortive mice as compared with the normal pregnant mice(all P<0.05).In addition,miR-142-3p was found to drastically inhibit the activation of the NF-κB signaling pathway(P<0.05).The number of ILC1s and the levels of pro-inflammatory cytokines were significantly downregulated and the activation of the NF-κB signaling pathway was inhibited in the miR-142-3p Agomir group(all P<0.05).Conclusion miR-142-3p can regulate ILC1s by targeting HMGB1 via the NF-κB signaling pathway,and attenuate the inflammation at the maternal-fetal interface in abortive mice.

Involvement of ERK1/2 and p38 MAPK in up-regulation of 14-3-3 protein induced by hydrogen peroxide preconditioning in PC12 cells

Objective To investigate the protective effects of hydrogen peroxide preconditioning （HPP） on the pheochromocytoma （PC12） cells treated with 1-methyl-4-phenylpyridinium （MPP^＋） and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 4′,6′-diamidino-2-phenylindole （DAPI） staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase （MAPK） were determined by Western blot. Enzyme-linked immunosorbent assay （ELISA） was used to measure the activity of extracellular signal-regulated protein kinase 1/2 （ERK1/2）. Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^＋ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^＋- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP＋ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.

MiR-183-5p promotes the progression of non-small cell lung cancer through targeted regulation of FOXO1

Objective To investigate miR-183-5p targeting to forkhead box protein O1(FOXO1)and its corresponding effect on the proliferation,migration,invasion,and epithelial-mesenchymal transition(EMT)of non-small cell lung cancer(NSCLC)cells.Methods NSCLC tissues and adjacent normal tissues from 60 patients with NSCLC adenocarcinoma were obtained via pathological biopsy or intraoperative resection.Several cell lines were cultured in vitro,including the human normal lung epithelial cell line BEAS-2B and human NSCLC cell lines A549,SPCA-1,PC-9,and 95-D.miR-183-5p and FOXO1 mRNA expression in tissues and cells were detected by qRT-PCR;the corresponding correlations in NSCLC tissues were analyzed using the Pearson test,and the relationship between miR-183-5p expression and clinicopathological parameters was analyzed.The miR-183-5p-mediated regulation of FOXO1 was verified by bioinformatics prediction alongside double luciferase,RNA-binding protein immunoprecipitation(RIP)assay,and pull-down experiments.A549 cells were divided into control,anti-miR-NC,anti-miR-183-5p,miR-NC,miR-183-5p,miR-183-5p+pcDNA3.1,and miR-183-5p+pcDNA3.1-FOXO1 groups.Cell proliferation,invasion,migration,apoptosis,and cell cycle distribution were detected using an MTT assay,clone formation assay,Transwell assay,scratch test,and flow cytometry,respectively.The expression of EMT-related proteins in the cells was analyzed by western blotting.The effect of miR-185-3p silencing on the development of transplanted tumors was detected by analyzing tumor formation in nude mice.Results miR-183-5p expression was significantly higher in NSCLC tissues and cells than in adjacent normal tissues,whereas FOXO1 mRNA expression was significantly down-regulated.There was a significant negative correlation between miR-183-5p and FOXO1 mRNA in NSCLC tissues(P<0.05).Additionally,the expression of miR-183-5p was significantly correlated with tumor size,tumor differentiation,and tumor-node-metastasis stage in patients with NSCLC(P<0.05).miR-183-5p targeted and inhibited FOXO1 expression.Compared to the anti-miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the anti-miR-183-5p group,whereas the protein expression of E-cadherin andα-catenin and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion were significantly lower in the anti-miR-183-5p group(P<0.05).Compared to the miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells in the miR-183-5p group were significantly higher,whereas the E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly lower;furthermore,the frequency of colony formation and invasion were significantly higher in the miR-183-5p group(P<0.05).Compared with the miR-183-5p+pcDNA3.1 group,the OD value,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group,whereas E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion was significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group(P<0.05).Overall,silencing miR-185-3p inhibited the growth of transplanted tumors and promoted FOXO1 expression.Conclusion Overexpression of miR-183-5p can inhibit apoptosis and promote the proliferation,migration,invasion,and EMT,of NSCLC cells by down-regulating FOXO1 expression.

Potential role of chitinase 3-like-1 in inflammation-associated carcinogenic changes of epithelial cells

The family of mammalian chitinases includes members both with and without glycohydrolase enzymatic activity against chitin, a polymer of N-acetylglucosamine. Chitin is the structural component of fungi, crustaceans, insects and parasitic nematodes, but is completely absent in mammals. Exposure to antigens containing chitin- or chitin-like structures sometimes induces strong T helper type-I responses in mammals, which may be associated with the induction of mammalian chitinases. Chitinase 3-like-1 （CHI3L1）, a member of the mammalian chitinase family, is induced specifically during the course of inflammation in such disorders as inflammatory bowel disease, hepatitis and asthma. In addition, CHI3L1 is expressed and secreted by several types of solid tumors including glioblastoma, colon cancer, breast cancer and malignant melanoma. Although the exact function of CHI3L1 in inflammation and cancer is still largely unknown, CHI3L1 plays a pivotal role in exacerbating the inflammatory processes and in promoting angiogenesis and remodeling of the extracellular matrix. CHI3L1 may be highly involved in the chronic engagement of inflammation which potentiates development of epithelial tumorigenesis presumably by activating the mitogen-activated protein kinase and the protein kinase B signaling pathways. Anti-CHI3L1 antibodies or pan-chitinase inhibitors may have the potential to suppress CHI3Ll-mediated chronic inflammation and the subsequent carcinogenic change in epithelial cells.

Effects of miR-101-3p on goat granulosa cells in vitro and ovarian development in vivo via STC1

Background:MiRNAs act as pivotal post-transcriptional gene mediators in the regulation of diverse biological processes,including proliferation,development and apoptosis.Our previous study has showed that miR-101-3p is differentially expressed in dairy goat ovaries compared single with multiple litters.The objective of this research was to explore the potential function and molecular mechanism of miR-101-3p via its target STC1 in goat ovarian growth and development.Results:cDNA libraries were constructed using goat granulosa cells transfected with miR-101-3p mimics and negative control by RNA-sequencing.In total,142 differentially expressed unigenes(DEGs)were detected between two libraries,including 78 down-regulated and 64 up-regulated genes.GO and KEGG enrichment analysis showed the potential impacts of DEGs on ovarian development.STC1 was singled out from DEGs for further research owing to it regulates reproductive-related processes.In vitro,bioinformatics analysis and 3′-UTR assays confirmed that STC1 was a target of miR-101-3p.ELISA was performed to detect the estrogen(E2)and progesterone(P4)levels.CCK8,EdU and flow cytometry assays were performed to detect the proliferation and apoptosis of granulosa cells.Results showed that miR-101-3p regulated STAR,CYP19A1,CYP11A1 and 3β-HSD steroid hormone synthesis-associated genes by STC1 depletion,thus promoted E2 and P4 secretions.MiR-101-3p also affected the key protein PI3K,PTEN,AKT and mTOR in PI3K-AKT pathway by STC1,thereby suppressing proliferation and promoting apoptosis of granulosa cells.In vivo,the distribution and expression levels of miR-101-3p in mouse ovaries were determined through fluorescence in situ hybridisation(FISH).Immunohistochemistry results showed that STC1 expression was suppressed in mouse ovaries in miR-101-3p-agonist and siRNA-STC1 groups.Small and stunted ovarian fragments,decreased numbers of follicles at diverse stages were observed using Hematoxylin-eosin(HE)staining,thereby showing unusual ovarian development after miR-101-3p overexpression or STC1 depletion.Inhibition of miR-101-3p manifested opposite results.Conclusions:Taken together,our results demonstrated a regulatory mechanism of miR-101-3p via STC1 in goat granulosa cells,and offered the first in vivo example of miR-101-3p and STC1 functions required for ovarian development.

Transplantation Expression of 4-1BB molecule on peripheral blood T cells in liver transplanted patients and its clinical implication

OBJECTIVE: To investigate the gene expression of 4-1BB in peripheral blood mononuclear cells (PBMCs) and its possible significance in clinical liver transplantation. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the gene expression of 4-1BB in PBMCs from 22 patients receiving liver transplantation, 13 patients with primary liver carcinoma (PLC), and 12 healthy controls. To determine whether 4-1BB molecule is also expressed on the surface of CD4^+ and CD8^+ T cell, flow cytometry was used to analyse the phenotype of T cell subsets from the blood of liver transplantation patients. RESULTS: 4-1BB mRNA was detected in PBMCs from stable survivors after liver transplantation, but almost not deteeted in PBMCs from PLC patients and healthy controls. Meanwhile, 4-1BB was almost not expressed on the surface of CD4^+ and CD8^+ T cells in healthy controls and PLC patients. A low level of 4-1BB expression, however, was found on the surface of CD4^+ and CD8^+ T cells from the stable survivors after liver transplantation. CONCLUSIONS: This study demonstrates that although patients are stable after liver transplantation, effector T-cells can also be activated through the signal of 4-1BB molecule and persistent irmmune response to grafts. Blockage of 4-1BB/4-1BBL pathway may benefitially reduce the clinical dosage of immunosuppressive agents and prolong the survival of grafts.

Differentially expressed genes and signalling pathways are involved in mouse osteoblast-like MC3T3-E1 cells exposed to 17-β estradiol

Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation.In this study, complementary DNA（cDNA） microarrays were used to identify and study the expression of novel genes that may be involved in MC3T3-E1 cells’ response to 17-b estradiol. MC3T3-E1 cells were inoculated in minimum essential media alpha（a-MEM）cell culture supplemented with 17-b estradiol at different concentrations and for different time periods. MC3T3-E1 cells treated with1028mol？L2117-b estradiol for 5 days exhibited the highest proliferation and alkaline phosphatase（ALP） activity; thus, this group was chosen for microarray analysis. The harvested RNA was used for microarray hybridisation and subsequent real-time reverse transcription polymerase chain reaction（RT-PCR） to validate the expression levels for selected genes. The microarray results were analysed using both functional and pathway analysis. In this study, microarray analysis detected 5 403 differentially expressed genes,of which 1 996 genes were upregulated and 3 407 genes were downregulated, 1 553 different functional classifications were identified by gene ontology（GO） analysis and 53 different pathways were involved based on pathway analysis. Among the differentially expressed genes, a portion not previously reported to be associated with the osteoblast response to oestrogen was identified. These findings clearly demonstrate that the expression of genes related to osteoblast proliferation, cell differentiation, collagens and transforming growth factor beta（TGF-b）-related cytokines increases, while the expression of genes related to apoptosis and osteoclast differentiation decreases, following the exposure of MC3T3-E1 cells to a-MEM supplemented with 17-b estradiol. Microarray analysis with functional gene classification is critical for a complete understanding of complementary intracellular processes. This microarray analysis provides large-scale gene expression data that require further confirmatory studies.

Asymmetric Synthesis of (-)-1-Trimethylsilyl-ethanol with Immobilized Saccharomyces Cerevisiae Cells in Water/Organic Solvent Diphasic System

Asymmetric synthesis of (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphasic system was studied. The effects of shake speed, hydrophobicity of organic solvent, volume ratio of water phase to organic phase, pH value of aqueous phase and reaction temperature on the initial reaction rate, maximum yield and enantiomeric excess (ee) of the product were systematically explored. All the above-mentioned factors had significant influence on the reaction. n-Hexane was found to be the best organic solvent for the reaction. The optimum shake speed, volume ratio of water phase to organic phase, pH value and reaction temperature were 150 r.min-1, 1/2, 8 and 30 ℃ respectively, under which the maximum yield and enantiomeric excess of the product were as high as 96.8% and 95.7%, which are 15% and 16% higher than those of the corresponding reaction performed in aqueous phase. To our best knowledge, this is the most satisfactory result obtained.

Effects of natural cerebrolysin on protective proteins and pro-apoptotic molecules in mesenchymal stem cells following beta-amyloid peptide1-40-induced endoplasmic reticulum stress

BACKGROUND： Studies have demonstrated that β-amyloid peptide （Aβ）, a characteristic pathological product of Alzheimer＇s disease （AD）, results in neuronal endoplasmic reticulum stress （ERS）. However, the mechanisms of traditional Chinese medicine against ERS in AD are poorly understood. OBJECTIVE： To measure expression levels of protective proteins （GRP78 and GRP94） of ER molecular partners and pro-apoptotic Caspase-12 ER membrane expression following application of traditional Chinese medicine natural cerebrolysin （NC） to treat Aβ1-40-induced ERS. DESIGN, TIME AND SETTING： A parallel-controlled study was performed at the Institute of Integrated Western and Traditional Chinese Medicine, Shenzhen Hospital of Southern Medical University between September 2006 and November 2008. MATERIALS： Sprague Dawley male rats, 6-8 weeks old, were used to harvest tibial and femoral bone marrow. Isolation and purification of mesenchymal stem cells （MSCs） were established from the whole bone marrow by removing non-adherent cells in primary and passage cultures. Aβ1-40 was provided by Sigma, USA. NC was provided by Shenzhen Institute of Integrated Chinese and Western Medicine, China. NC was predominantly composed of Renshen （Radix Ginseng）, Tianma （Rhizoma Gastrodiae）, and Yinxingye （Ginkgo Leaf） in a proportion of 1 ： 2： 2. Following conventional water extraction technology, an extract （1 ： 20） was prepared. Six adult, male, New Zealand rabbits underwent intragastric administration of NC extract （0.976 g/kg per day） for 1 month to prepare NC-positive serum, and the remaining 6 rabbits received intragastric administration of physiological saline to prepare normal blank serum. METHODS： A total of 500 nmol/L Aβ1-40 was used to establish ERS models of primary cultured MSCs. AD cell models were incubated with different doses of NC-positive serum （2.5%, 5%, and 10%）. MSCs treated with normal blank serum served as normal blank controls. MAIN OUTCOME MEASURES： Reverse transcription-polymerase chain reaction and fluorescent immunocytochemistry were respectively used to measure mRNA and protein expression levels of GRP78, GRP94, and Caspase-12 in MSCs. RESULTS： Following Aβ1-40 exposure, mRNA and protein expression levels of GRP78 and GRP94, as well as Caspase-12, significantly increased （P 〈 0.05）, suggesting successful establishment of ERS models. Following NC-positive serum application, mRNA and protein expression levels of GRP78 and GRP94 in MSCs significantly increased （P 〈 0.05 or P 〈 0.01）. However, mRNA and protein expression levels of Caspase-12 significantly decreased （P 〈 0.05, or P 〈 0.01） compared with the ERS model group. These effects were dose-dependent. CONCLUSION： NC downregulated Caspase-12 expression and upregulated GRP78 and GRP94 expression in MSCs in a dose-dependent manner under the state of Aβ1-40-induced ERS.

Overexpression of inhibinα(1-32)fusion protein promotes apoptosis and cell cycle arrest in a cervical cancer cell model(Hela cells)

Inhibins play important roles in the reproductive system. To evaluate whether inhibin α (1-32) fusion protein plays a role in cervical cancer growth, the plasmid pVAX-inhα was constructed and its effect on proliferation and apoptosis of the human cervical cancer cell line (Hela) was checked by flow cytometry and real-time PCR. The expression and localization of inhibin α protein were detected by RT-PCR and confocal mi- croscopy which showed that inhibin α protein was expressed and localized in the nucleus of Hela cells. Over ex- pression of inhibin α gene significantly induced cell apoptosis and ceased S phase of cell cycle. Furthermore, cell proliferation was significantly suppressed 96 h post-transfection and mRNA level of anti-apoptosis genes (Bcl-2, NFκB) were decreased but pro-apoptosis genes (Bax, wild type p53) and inhibin co receptor (TGFβR3) were increased, indicating that inhibin, through its co-receptor, might activate apoptotic and cell growth cascades which regulate proliferation and apoptosis in Hela cells. These results suggest that inhibin α (1-32) fusion pro- tein, located in the cell nucleus, can regulate Hela cells growth and apoptosis by induction of apoptotic pathways such as NFκB, Bcl-2 and p53 families. These findings may have a significant impact on future research regarding cervical cancer cell lines.

Upregulation of 25-hydroxyvitamin D_3-1α-hydroxylase by butyrate in Caco-2 cells

AIM： To investigate the possible involvement of 25-hydroxyvitamin D3-1cx-hydroxylase [1α-25（OH）2D3] in butyrate-induced differentiation in human intestinal cell line Caco-2 cells. METHODS： Caco-2 cells were incubated either with 3 mmol/L butyrate and 1 umol/L 25（OH）2D3 or with 1 umol/L 1α-25（OH）2D3 for various time intervals ranging from 0 to 72 h. Additionally, cells were co-incubated with butyrate and either 25（OH）2D3 or 1α-25（OH）2D3. 1α-25（OH）2D3 mRNA was determined semi-quantitatively using the fluorescent dye PicoGreen. Immunoblotting was used for the detection of 1α-25（OH）2D3 protein. Finally, enzymatic activity was measured by ELISA. RESULTS： Both butyrate and 1α-25（OH）2D3 stimulated differentiation of Caco-2 cells after a 48 h incubation period, while 25（OH）2D3 had no impact on cell differentiation. Synergistic effects on differentiation were observed when cells were co-incubated with butyrate and vitamin D metabolite. Butyrate transiently upregulated 1α-25（OH）2D3 mRNA followed by a timely delayed protein upregulation. Coincidently, enzymatic activity was enhanced significantly. The induction of the enzyme allowed for comparable differentiating effects of both vitamin D metabolites. CONCLUSION： Our experimental data provide a further mechanism for the involvement of the vitamin D signaling pathway in colonic epithelial cell differentiation by butyrate. The enhancement of 1α-25（OH）2D3 followed by antiproliferative effects of the vitamin D prohormone in the Caco-2 cell line suggest that 25（OH）2D3 in combination with butyrate may offer a new therapeutic approach forthe treatment of colon cancer.

Neural stem cell-conditioned medium upregulated the PCMT1 expression and inhibited the phosphorylation of MST1 in SHSY5Y cells induced by Aβ_(25-35)

A progressive neurodegenerative disease,Alzheimer’s disease(AD).Studies suggest that highly expressed protein isoaspartate methyltransferase 1(PCMT1)in brain tissue.In the current study,we explored the effects of neural stem cell-conditioned medium(NSC-CDM)on the PCMT1/MST1 pathway to alleviate Aβ_(25-35)-induced damage in SH-SY5Y cells.Our data suggested that Aβ_(25-35) markedly inhibited cell viability.NSC-CDM or Neural stem cell-complete medium(NSC-CPM)had a suppression effect on toxicity when treatment with Aβ_(25-35),with a greater effect observed with NSC-CDM.Aβ_(25-35)+NSC-CDM group exhibited an increase in PCMT1 expression.sh-PCMT1 markedly decreased cell proliferation and suppressed the protective role of NSC-CDM through the induction of apoptosis and improved p-MST1 expression.Overexpression of PCMT1 reversed the Aβ_(25-35)-induced decrease in cell proliferation and apoptosis.In summary,our findings suggest that NSC-CDM corrects the Aβ_(25-35)-induced damage to cells by improving PCMT1 expressions,which in turn reduces phosphorylation of MST1.

Expression and significance of B7-H1 in peripheral blood dendritic cells from patients with bladder cancer

Objective： The aim of this study was to study the expression and the clinical significance of B7-H1 on dendritic cells （DCs） in peripheral blood from patients with bladder cancer. Methods： Peripheral blood mononuclear cell were disparted from 30 bladder cancer patients and 7 healthy controls by density gradient centfifugation and then co-cultured. The expres- sion of B7-H1 on DCs were analyzed by flow cytometry. Results： Expression of BT-H1 on DCs in bladder cancer was higher than healthy controls （P 〈 0.01）. And the expression were strongly associated with the pathological grade and clinical stage of bladder cancer （P 〈 0,05）. Conclusion： The up-regulation of B7-H1 on DCs was strongly associated with neoplastic progres-sion of bladder cancer. B7-H1/programmed death （PD）-1 signal pathway may also play an important role in immune escape of bladder cancer during initial phase of T cell immune response.

Oligomerized Amyloid-<i>β</i>_1-40Peptide Favors Cholesterol, Oxysterol, and Fatty Acid Accumulation in Human Neuronal SK-N-BE Cells

Amyloid peptide, the main component of senile plaques, is a major biological characteristic of Alzheimer’s disease (AD). The aim of the present study conducted on human neuronal SK-N-BE cells was to evaluate whether oligomerized Aβ1-40-induced cell damages was associated with lipid modifications. Under treatment with Aβ1-40 (10 - 100 μM;24 - 48 h), cell viability was recorded with the MTT test and by measuring LDH activity. Mitochondrial transmembrane potential and ATP production were assessed using flow cytometry and a luciferase-based ATP bioluminescence assay, respectively. Annexin V-CF647 staining assay for cell apoptosis detection was performed using flow cytometry. Potentially intracellular cytotoxic lipids (oxysterols: 7α-hydroxycholesterol (7α-OHC), 7β-hydroxycholesterol (7β-OHC), and 7-ketocholesterol (7KC), 24(S)-hydroxycholesterol;arachidonic acid (C20:4 n-6);VLCFAs (C22:0, C24:0, C24:6 and C26:0)) were measured using gas chromatography coupled with mass spectrometry. The cellular level of docosahexaenoic acid (C22:6 n-3), often altered in AD, was also quantified. In the presence of Aβ1-40, the percentage of MTT-positive cells decreased and was associated with an increase in LDH activity. In addition, treatment with oligomerized Aβ1-40 induced a decrease of mitochondrial transmembrane potential as well as an apoptotic cell death. Sterol analysis revealed a higher cholesterol level and a significant increase of cytotoxic oxysterols per cell (7KC + 7β-OHC), and of the [(7β-OHC + 7KC)/cholesterol] ratio, considered as a lipid peroxidation index, in Aβ1-40-treated cells. An enhancement of C20:4 n-6, C22:6 n-3 and saturated VLCFAs was also observed. Therefore, Aβ1-40-induced side effects are associated with intracellular accumulation of lipids, especially cholesterol, oxysterols (7β-OHC, 7KC), C20:4 n-6, and saturated VLCFAs, which could in turn contribute to neurotoxicity.

大黄素诱导白血病KG-1a细胞凋亡及对Bcl-2/Bax mRNA表达的影响

目的本研究观察大黄素(emodin)对人急性髓系白血病KG-1a细胞的增殖及凋亡影响,探讨Bcl-2/Bax基因在其中的作用。方法采用四唑蓝比色试验(MTT)检测大黄素对KG-1a细胞增殖的影响;流式细胞术(FCM)测定细胞周期变化与凋亡情况;RT-PCR法检测大黄素作用后细胞Bcl-2/Bax mRNA表达的变化。结果大黄素能抑制KG-1a细胞的增殖,作用48 h的半数抑制浓度(IC50)约为171.8μmol/L流式细胞仪分析出现典型的亚二倍体峰(凋亡峰),将细胞阻滞于G0/G1期,大黄素作用后KG-1a细胞Bcl-2基因表达下调,而Bax基因表达上调,并呈量效关系。结论大黄素可诱导KG-1a细胞凋亡,其机制可能与下调Bcl-2,上调Bax基因表达水平有关。

白藜芦醇增强TRAIL对人髓系白血病KG-1a细胞的细胞毒作用

目的：观察白藜芦醇作用前后TRAIL对人髓系白血病KG-1a细胞的细胞毒作用的变化。方法：流式细胞仪检测KG-1a细胞表面CD34和CD38的表达,二甲氧唑黄（XTT）细胞增殖及细胞毒性检测试剂盒检测白藜芦醇作用前后TRAIL对KG-1a细胞增殖的影响,AnnexinV-FITC/PI染色流式细胞仪检测细胞凋亡变化。流式细胞仪检测白藜芦醇作用前后KG-1a细胞表面TRAIL死亡受体表达变化。结果：人髓系白血病KG-1a细胞CD34＋CD38-占（58.67±2.87）%,101 000 ng/ml的TRAIL对KG-1a细胞增殖无明显影响,但对白藜芦醇作用后的KG-1a细胞的增殖有明显抑制作用,白藜芦醇能促进TRAIL诱导KG-1a细胞凋亡,并能上调KG-1a细胞表面TRAIL死亡受体DR5的表达。结论：白藜芦醇能增强TRAIL对人髓系白血病KG-1a细胞的细胞毒作用,其机制可能与白藜芦醇上调KG-1a细胞表面TRAIL死亡受体DR5的表达有关。

重载铁路60 kg·m^(-1)贝氏体钢轨试验及应用

为开发适应重载铁路发展和应用的高强高韧高耐磨钢轨,在对60 kg·m^(-1)贝氏体钢轨进行试制的基础上,利用蔡司倒置式光学显微镜、透射电镜及静态液压万能试验机,对钢轨母材和焊接接头的组织性能进行检验,并对钢轨和道岔辙叉翼轨、尖轨进行试铺,系统分析强韧和耐磨性能。结果表明:60 kg·m^(-1)贝氏体钢轨的母材组织均匀,基体为无碳化物贝氏体,存在少量稳定残余奥氏体和M/A组织,硬度较高,耐磨性良好,具有良好的强韧性匹配;焊接接头组织均匀,性能良好;铺设在重载线路曲线段的贝氏体钢轨服役时间达48个月、通过总重近6亿吨时,其使用寿命比珠光体钢轨提高1倍以上,道岔辙叉翼轨和尖轨的使用寿命比U75V钢轨提高3~4倍,且均未出现重伤问题,贝氏体钢轨还具有较强的抗剥离掉块能力。