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941.
942.
943.
TGF-beta2 stimulates cranial suture closure through activation of the Erk-MAPK pathway 总被引:2,自引:0,他引:2
Lee SW Choi KY Cho JY Jung SH Song KB Park EK Choi JY Shin HI Kim SY Woo KM Baek JH Nam SH Kim YJ Kim HJ Ryoo HM 《Journal of cellular biochemistry》2006,98(4):981-991
Cranial sutures are important growth sites of the skull. During suture closure, the dura mater is one of the most important sources of various positive and negative regulatory signals. Previous results indicate that TGF-beta2 from dura mater strongly accelerates suture closure, however, its exact regulatory mechanism is still unclear. In this study, we confirmed that removal of dura mater in calvarial organ culture strongly accelerates sagittal suture closure and that this effect is further enhanced by TGF-beta2 treatment. TGF-beta2 stimulated cell proliferation in the MC3T3-E1 cell line. Similarly, it stimulated the proliferation of cells in the sutural space in calvarial organ culture. Furthermore, TGF-beta2-mediated enhanced cell proliferation and suture closure were almost completely inhibited by an Erk-MAPK blocker, PD98059. These results indicate that TGF-beta2-induced activation of Erk-MAPK is an important signaling component that stimulates cell proliferation to enrich osteoprogenitor cells, thereby promoting their differentiation into osteoblasts to achieve a rapid calvarial bone expansion. 相似文献
944.
Asiatic acid (AA), a triterpene, is known to be cytotoxic to several tumor cell lines. AA induces dose- and time-dependent
cell death in U-87 MG human glioblastoma. This cell death occurs via both apoptosis and necrosis. The effect of AA may be
cell type-specific as AA-induced cell death was mainly apoptotic in colon cancer RKO cells. AA-induced glioblastoma cell death
is associated with decreased mitochondrial membrane potential, activation of caspase-9 and -3, and increased intracellular
free Ca2+. Although treatment of glioblastoma cells with the caspase inhibitor zVAD-fmk completely abolished AA-induced caspase activation,
it did not significantly block AA-induced cell death. AA-induced cell death was significantly prevented by an intracellular
Ca2+ inhibitor, BAPTA/AM. Taken together, these results indicate that AA induces cell death by both apoptosis and necrosis, with
Ca2+-mediated necrotic cell death predominating. 相似文献
945.
Mrácek J Greiner S Cho WK Rauwolf U Braun M Umate P Altstätter J Stoppel R Mlcochová L Silber MV Volz SM White S Selmeier R Rudd S Herrmann RG Meurer J 《Genomics》2006,88(3):372-380
Coevolution of cellular genetic compartments is a fundamental aspect in eukaryotic genome evolution that becomes apparent in serious developmental disturbances after interspecific organelle exchanges. The genus Oenothera represents a unique, at present the only available, resource to study the role of the compartmentalized plant genome in diversification of populations and speciation processes. An integrated approach involving cDNA cloning, EST sequencing, and bioinformatic data mining was chosen using Oenothera elata with the genetic constitution nuclear genome AA with plastome type I. The Gene Ontology system grouped 1621 unique gene products into 17 different functional categories. Application of arrays generated from a selected fraction of ESTs revealed significantly differing expression profiles among closely related Oenothera species possessing the potential to generate fertile and incompatible plastid/nuclear hybrids (hybrid bleaching). Furthermore, the EST library provides a valuable source of PCR-based polymorphic molecular markers that are instrumental for genotyping and molecular mapping approaches. 相似文献
946.
947.
Se-Eun Kang Long-Guo Jin Jae-Suk Choi Ji-Young Cho Hyun-Woung Shin Yong-Ki Hong 《Journal of applied phycology》2006,18(3-5):483-487
Genetic responses of the seaweed Ulva pertusa to pine needle ash have been compared using differential display technique. The tissue viability was assessed to evaluate the stress level with triphenyltetrazolium chloride. Total RNA, from tissues treated in seawater containing ash, was reverse transcribed and amplified by PCR with arbitrary primers. The genetic fragments responding to the stress were selectively isolated from agarose gel and sequenced with a DNA auto sequencer. According to sequence analysis, an ash-inducible gene (342 bp) and an ash-suppressed gene (1690 bp) were identified as hypothetical proteins. 相似文献
948.
Multiple resistance and biochemical mechanisms of pyridaben resistance in Tetranychus urticae (Acari: Tetranychidae) 总被引:3,自引:0,他引:3
A field colony of Tetranychus urticae (Koch) (Acari: Tetranychidae) resistant to pyridaben was selected with pyridaben successively for 20 generations to produce the PR-20 strain. Resistance and multiple resistance levels of the PR-20 strain to 15 acaricides were determined using a spray bioassay. The PR-20 strain was extremely resistant to pyridaben (resistance ratio [RR] = 240]. The strain exhibited extremely strong resistance to fenpyroximate (RR=373) and acrinathrin (RR=329) and strong resistance to benzoximate (RR=84). An RR = 10-40 was observed with abamectin, fenazaquin, fenbutatin oxide, fenpropathrin, and tebufenpyrad. The PR-20 strain showed low levels of resistance (RR <10) to azocyclotin, bromopropylate, chlorfenapyr, dicofol, milbemectin, and propargite. Synergist experiments with different metabolic inhibitors revealed that piperonyl butoxide (PBO), a mixed function oxidase (MFO) inhibitor, had the greatest effect on pyridaben resistance. PBO significantly caused pyridaben resistance in the PR-20 strain to drop to the full susceptibility level of the susceptible (S) strain. However, there was no significant difference in MFO activities measured using a model substrate between the S and PR-20 strains. These results suggest that use of certain acaricides with little multiple resistance or PBO will be useful for the management of pyridaben resistance in the field. 相似文献
949.
Yoo SA Park BH Park GS Koh HS Lee MS Ryu SH Miyazawa K Park SH Cho CS Kim WU 《Journal of immunology (Baltimore, Md. : 1950)》2006,177(4):2681-2690
Calcineurin is a calcium-activated phosphatase to mediate lymphocyte activation and neuron signaling, but its role in inflammatory arthritis remains largely unknown. In this study, we demonstrate that calcineurin was highly expressed in the lining layer, infiltrating leukocytes, and endothelial cells of rheumatoid synovium. The basal expression levels of calcineurin were higher in the cultured synoviocytes of rheumatoid arthritis patients than those of osteoarthritis patients. The calcineurin activity in the synoviocytes was increased by the stimulation with proinflammatory cytokines such as IL-1beta and TNF-alpha. Moreover, rheumatoid arthritis synoviocytes had an enlarged intracellular Ca(2+) store and showed a higher degree of [Ca(2+)](i) release for calcineurin activity than osteoarthritis synoviocytes when stimulated with either TNF-alpha or phorbol myristate acetate. IL-10, an anti-inflammatory cytokine, failed to increase the Ca(2+) and calcineurin activity. The targeted inhibition of calcineurin by the overexpression of calcineurin-binding protein 1, a natural calcineurin antagonist, inhibited the production of IL-6 and matrix metalloproteinase-2 by rheumatoid synoviocytes in a similar manner to the calcineurin inhibitor, cyclosporin A. Moreover, the abundant calcineurin expression was found in the invading pannus in the joints of mice with collagen-induced arthritis. In these mice, calcineurin activity in the cultured synovial and lymph node cells correlated well with the severity of arthritis, but which was suppressed by cyclosporin A treatment. Taken together, our data suggest that the abnormal activation of Ca(2+) and calcineurin in the synoviocytes may contribute to the pathogenesis of chronic arthritis and thus provide a potential target for controlling inflammatory arthritis. 相似文献
950.
Sung-Jin Cho Dae-Hee Lee Hyuk-Jae Kwon Chi Hyun Ahn Soon Cheol Park Kil-Sang Shin 《Development genes and evolution》2006,216(6):353-351
An echiuroid species, Urechis unicinctus, was surveyed for Hox genes using polymerase chain reaction with homeobox-specific degenerate primers. We identified nine distinct homeodomain-containing gene fragments. These nine fragments were classified by comparative analysis. This analysis revealed that this echiuroid possessed at least three Hox genes from the anterior group, five from the central group, and one from the posterior group.Sung-Jin and Dae-Hee Lee contributed equally to this work.An erratum to this article can be found at 相似文献