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71.
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73.
Hsia SM Kuo YH Chiang W Wang PS 《American journal of physiology. Endocrinology and metabolism》2008,295(3):E719-E726
Dysmenorrhea is directly related to elevated PGF(2alpha) levels. It is treated with nonsteroid antiinflammatory drugs (NSAIDs) in Western medicine. Since NSAIDs produce many side effects, Chinese medicinal therapy is considered as a feasible alternative medicine. Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf.) has been used as a traditional Chinese medicine for treating dysmenorrhea. However, the relationship between smooth muscle contraction and adlay extracts remains veiled. Therefore, we investigated this relationship in the rat uterus by measuring uterine contraction activity and recording the intrauterine pressure. We studied the in vivo and in vitro effects of the methanolic extracts of adlay hull (AHM) on uterine smooth muscle contraction. The extracts were fractionated using four different solvents: water, 1-butanol, ethyl acetate, and n-hexane; the four respective fractions were AHM-Wa, AHM-Bu, AHM-EA, and AHM-Hex. AHM-EA and its subfractions (175 microg/ml) inhibited uterine contractions induced by PGF(2alpha), the Ca(2+) channel activator Bay K 8644, and high K(+) in a concentration-dependent manner in vitro. AHM-EA also inhibited PGF(2alpha)-induced uterine contractions in vivo; furthermore, 375 microg/ml of AHM-EA inhibited the Ca(2+)-dependent uterine contractions. Thus 375 microg/ml of AHM-EA consistently suppressed the increases in intracellular Ca(2+) concentrations induced by PGF(2alpha) and high K(+). We also demonstrated that naringenin and quercetin are the major pure chemical components of AHM-EA that inhibit PGF(2alpha)-induced uterine contractions. Thus AHM-EA probably inhibited uterine contraction by blocking external Ca(2+) influx, leading to a decrease in intracellular Ca(2+) concentration. Thus adlay hull may be considered as a feasible alternative therapeutic agent for dysmenorrhea. 相似文献
74.
J S Sun K M Shieh H C Chiang S Y Sheu Y S Hang F J Lu Y H Tsuang 《Free radical biology & medicine》1999,26(9-10):1100-1107
Benzophenone is an ultraviolet (UV)-absorbing agent that has been used in industry and medicine for more than 30 years. Consumers of cosmetics and sunscreens containing UV-absorbers are exposed to benzophenones on a daily basis, owing to the widespread use of these compounds. However, the efficacy of these compounds as scavengers of oxidative stress is still not well established. In the present study, we investigate the antioxidative capacity of six sunscreen benzophenone compounds. A primary myoblast culture was mixed in vitro with 100 microM menadione. The cytotoxic effect by menadione-induced oxidative stress was monitored by the lucigenin- or luminol-amplified chemiluminescence, methylthiotetrazole (MTT) assay, and the antioxidative effects of various benzophenone compounds were evaluated. The results showed that the addition of menadione can induce oxidative stress on myoblasts by superoxide and hydrogen peroxide production, which can be eradicated by superoxide dismutase (SOD) and catalase, respectively, in a dose-dependent mode. The catalase has a protective effect on the cytotoxicity induced by menadione as measured by the MTT assay, while the SOD does not. The selected benzophenones also have a significant scavenging effect on the menadione-induced cell death on the myoblasts. The ortho-dihydroxyl structure and other hydroxy groups in the same ring have a stronger scavenging effect on the superoxide anion on myoblasts; thus, a stable penoxy radical may be formed. The mechanism of this effect remains to be clarified. 相似文献
75.
Chun-Hao Tsai Yi-Chun Chiang Hsien-Te Chen Po-Hao Huang Horng-Chaung Hsu Chih-Hsin Tang 《Biochimica et Biophysica Acta (BBA)/General Subjects》2013
Background
Diabetes is an independent risk factor of osteoarthritis (OA). Angiogenesis is essential for the progression of OA. Here, we investigated the intracellular signaling pathways involved in high glucose (HG)-induced vascular endothelial growth factor (VEGF) expression in human synovial fibroblast cells.Methods
HG-mediated VEGF expression was assessed with qPCR and ELISA. The mechanisms of action of HG in different signaling pathways were studied using Western blotting. Knockdown of proteins was achieved by transfection with siRNA. Chromatin immunoprecipitation assays were used to study in vivo binding of c-Jun to the VEGF promoter.Results
Stimulation of OA synovial fibroblasts (OASF) with HG induced concentration- and time-dependent increases in VEGF expression. Treatment of OASF with HG increased reactive oxygen species (ROS) generation. Pretreatment with NADPH oxidase inhibitor (APO or DPI), ROS scavenger (NAC), PI3K inhibitor (Ly294002 or wortmannin), Akt inhibitor, or AP-1 inhibitor (curcumin or tanshinone IIA) blocked the HG-induced VEGF production. HG also increased PI3K and Akt activation. Treatment of OASF with HG increased the accumulation of phosphorylated c-Jun in the nucleus, AP-1-luciferase activity, and c-Jun binding to the AP-1 element on the VEGF promoter.Conclusions
Our results suggest that the HG increases VEGF expression in human synovial fibroblasts via the ROS, PI3K, Akt, c-Jun and AP-1 signaling pathway.General significance
We link high glucose on VEGF expression in osteoarthritis. 相似文献76.
Chen YC Su YN Chou PC Chiang WC Chang MC Wang LS Teng SC Wu KJ 《The Journal of biological chemistry》2005,280(37):32505-32511
Nijmegen breakage syndrome (NBS) is a chromosomal instability syndrome associated with cancer predisposition, radiosensitivity, microcephaly, and growth retardation. The NBS gene product, NBS1 (p95) or nibrin, is a part of the hMre11 complex, a central player associated with double strand break repair. We previously demonstrated that c-Myc directly activates NBS1 expression. Here we have shown that constitutive expression of NBS1 in Rat1a and HeLa cells induces/enhances their transformation. Repression of endogenous NBS1 levels using short interference RNA reduces the transformation activity of two tumor cell lines. Increased NBS1 expression is observed in 40-52% of non-small cell lung carcinoma, hepatoma, and esophageal cancer samples. NBS1 overexpression stimulates phosphatidylinositol (PI) 3-kinase activity, leading to increased phosphorylation levels of Akt and its downstream targets such as glycogen synthase kinase 3beta and mammalian target of rapamycin in different cell lines and tumor samples. Transformation induced by NBS1 overexpression can be inhibited by a PI3-kinase inhibitor (LY294002). Repression of endogenous Akt expression by short interference RNA decreases the transformation activity of Rat1a cells overexpressing NBS1. These results indicate that overexpression of NBS1 is an oncogenic event that contributes to transformation through the activation of PI3-kinase/Akt. 相似文献
77.
Tsai CT Chiang FT Chen WP Hwang JJ Tseng CD Wu CK Yu CC Wang YC Lai LP Lin JL 《Cell calcium》2011,49(1):1-11
Angiotensin II (AngII) has been implicated in the mechanism of atrial fibrillation (AF). There may be calcium-dependent pro-fibrillatory effect of AngII on atrial myocytes. We used cultured confluent HL-1 atrial myocyte monolayer with spontaneously propagated depolarization to study direct pro-fibrillatory effect of AngII and its molecular mechanism. AngII stimulation induced fibrillatory-like complex electrogram and calcium wave propagation. AngII shortened action potential duration and augmented calcium transient, thus increasing electrochemical gradient of forward-mode sodium-calcium exchanger (NCX) current and induced frequent irregular afterdepolarizations. AngII increased expression of sodium-calcium exchanger (NCX), further increasing calcium-membrane voltage coupling gain. The fibrillatory effect of AngII was attenuated by NCX blocker SEA0400 and NCX siRNA knockdown. AngII increased expression of L-type calcium channel and augmented calcium transient through PKC and CREB. The fibrillatory effect of AngII was also attenuated by PKC inhibitor chelerythrine and dominant negative form of CREB. In conclusions, AngII itself may electrically contribute to the mechanism of AF through increasing NCX expression and augmenting calcium transient, which is PKC and CREB dependent. Specific genetic knockdown of NCX attenuated calcium mediated afterdepolarization and complex electrogram. 相似文献
78.
Chia-Hsuan Chen Hsiu-Lin Huang Mu-Tzu Chang Li-Chia Chiang Shih-Lin Cheng Bing-Tsan Liu Chih-Hua Wang Ming-Che Wu Mu-Chiou Huang 《Biologia》2011,66(6):1196-1201
The complete mitochondrial genome sequence of the Formosan sambar (Rusa unicolor swinhoei) was obtained by DNA sequencing based on PCR fragments amplified by 26 primer pairs designed by ourselves. The results indicated
that the mtDNA is 16,505 bp in size. This is the first report on mitochondrial DNA (mtDNA) sequence analysis of the Formosan
sambar and the sequence was deposited in the GenBank database under the accession number DQ989636. The complete mitochondrial
sequence included the following gene sequences: 12S and 16S rRNAs, 22 tRNAs and 13 protein-coding genes. The base composition
of the sequence was as follows: A, 33.51%; T, 28.97%; C, 24.07%; and G, 13.46%. The mitochondrial D-loop region was also analyzed
for comparative purposes in the Formosan sambar and 13 other species within the Cervidae family using neighbour-joining method.
The phylogenetic tree demonstrated that there are two separate groups, a European type and an Asian type, within the Cervidae
family. The D-loop sequences of mtDNA of 24 Formosan sambar animals were compared, and the results showed that the Formosan
sambar can be divided into two clades. 相似文献
79.
寄主龄期、过寄生和寄主饥饿处理对菜蛾盘绒茧蜂幼蜂及畸形细胞发育的影响 总被引:1,自引:2,他引:1
过寄生、寄生时寄主龄期和寄生后寄主饥饿处理影响菜蛾盘绒茧蜂Cotesia plutellae(Kurdj.)幼蜂及畸形细胞的发育。显微解剖和观察表明,4龄小菜蛾Plutella xylostella L.幼虫被寄生后,其体内菜蛾盘绒茧蜂幼蜂发育不整齐、假寄生比例增高。过寄生后,每头被寄生的寄主血腔中畸形细胞数量明显增多,但直径变小;随着过寄生程度的加剧,幼蜂发育严重受阻。寄主营养显著影响体内幼蜂及畸形细胞的发育,被寄生的小菜蛾经饥饿处理62 h后,体内畸形细胞的数量、活性明显降低,与此同时,幼蜂的发育也受到明显抑制,寄主发育与寄生蜂和畸形细胞的发育呈正相关性。由此可见,寄主不同龄期、过寄生及寄主营养状况均对寄主体内幼蜂和畸形细胞发育产生影响。 相似文献
80.
Summary Inorganic sulfate salts are used to form aqueous two-phase systems with polyethylene glycol (PEG) for enzyme purification. Two enzymes, L-aspartase and fumarase produced byEscherichia coli are efficiently separated into different phases in spite of the high degree of similarity in molecular weight and amino acid sequence between them. The ratio of L-aspartase to fumarase in the PEG-rich phase is more than sixty (60) times the ratio before extraction. A high degree of purification in a single extraction step can be achieved by careful selections of PEG molecular weight, pH, cation of the salts, and sodium chloride levels. Cations of sulfate-containing salts in the following order: NH
4
+
>Na+>Mg2+ tend to increase the partition of L-aspartase in the PEG-rich phase. The maximal degree of enzyme purification is obtained by using PEG 4000 and ammonium sulfate as a phase system at a stable pH for both enzymes. 相似文献