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951.
Physiological and biochemical responses to acute ozone-induced oxidative stress in Medicago truncatula. 总被引:1,自引:0,他引:1
Michael C Puckette Hua Weng Ramamurthy Mahalingam 《Plant Physiology and Biochemistry》2007,45(1):70-79
Oxidative signaling mediated by reactive oxygen species (ROS) is a central component of biotic and abiotic stresses in plants. Acute ozone (O(3)) fumigation is a useful non-invasive treatment for eliciting endogenous ROS in planta. In this study, 38 different accessions of the model legume, Medicago truncatula, from various geographical regions were fumigated with 300 nmol mol(-1) of O(3) for a period of six hours. Phenotypic symptoms were evaluated 24 and 48 h after the end of treatment. A majority of the accessions showed distinct visible damage. Eight accessions showing varying sensitivities to ozone were subjected to biochemical analysis to evaluate correlations between ozone damage and levels of ROS, antioxidants, and lipid peroxidation. Two-way analysis of variance indicated highly significant interactions between O(3) damage and levels of ROS, ascorbate, glutathione and lipid peroxidation. There were significant differences among the accessions for these traits before and after the end of O(3) fumigation, as indicated by equal variance Student's t-test. This study suggests that multiple physiological and biochemical mechanisms may govern O(3) tolerance or sensitivity. Surveying a large collection of germplasm led to identification of multiple resistant and sensitive lines for investigating molecular basis of O(3) phytotoxicity. The most resistant JE154 accession also showed enhanced tolerance to chronic O(3) and dehydration stress, suggesting germplasm with increased tolerance to acute O(3) can be a useful resource for improving resistance to multiple abiotic stressors. 相似文献
952.
De‐Yi Yan Jiahao Tang Liang Chen Bingzhang Wang Sheji Weng Zhongjie Xie Zong‐Yi Wu Zijian Shen Bingli Bai Lei Yang 《Journal of cellular and molecular medicine》2020,24(3):2330-2341
Osteoporosis is caused by disturbance in the dynamic balance of bone remodelling, a physiological process, vital for maintenance of healthy bone tissue in adult humans. In this process, a new bone is formed by osteoblasts and the pre‐existing bone matrix is resorbed by osteoclasts. Imperatorin, a widely available and inexpensive plant extract with antioxidative and apoptotic effects, is reported to treat osteoporosis. However, the underlying mechanism and specific effects on bone metabolism have not been elucidated. In this study, we used rat bone marrow‐derived mesenchymal stem cells and found that imperatorin can activate RUNX2, COL1A1 and osteocalcin by promoting the Ser9 phosphorylation of GSK3β and entry of β‐catenin into the nucleus. Imperatorin also enhanced the production of phospho‐AKT (Ser473), an upstream factor that promotes the Ser9 phosphorylation of GSK3β. We used ipatasertib, a pan‐AKT inhibitor, to inhibit the osteogenic effect of imperatorin, and found that imperatorin promotes osteogenesis via AKT/GSK3β/β‐catenin pathway. Next, we used rat bone marrow‐derived monocytes, to check whether imperatorin inhibits osteoclast differentiation via AKT/GSK3β/β‐catenin pathway. Further, we removed the bilateral ovaries of rats to establish an osteoporotic model. Intragastric administration of imperatorin promoted osteogenesis and inhibited osteoclast in vivo. Our experiments showed that imperatorin is a potential drug for osteoporosis treatment. 相似文献
953.
目的探讨骨髓间充质干细胞(MSCs)对肾移植受者T淋巴细胞分化和miRNA-155表达的影响。
方法选取2013年1月至2017年12月于福州总医院接受MSCs诱导+同种异体肾移植术的受者20例(MSCs组),对照组为同期配对的异体肾移植受者20例。两组患者术后免疫抑制方案均为霉酚酸酯+他克莫司+强的松。两组患者分别于移植术前、术后第15天抽取静脉血,流式细胞仪检测外周血CD4+ CD25+ FoxP3+ Treg细胞/?CD4+细胞亚群比值;ELISA检测白细胞介素2(IL-2)、肿瘤坏死因子α(TNF-α)和白细胞介素10(IL-10)浓度;免疫磁珠分选外周血T淋巴细胞后,Rea1-time PCR法检测外周血T淋巴细胞中miRNA-?155的表达。两组间均数比较采用独立t检验,治疗前后均数比较采用配对t检验。
结果移植前两组肾移植受者外周血CD4+ CD25+ FoxP3+ Treg细胞/?CD4+细胞比值、IL-2、IL-?10、TNF-α、T淋巴细胞miRNA-155表达水平差异均无统计学意义(P均> 0.05);术后第15天,与对照组相比,MSCs组外周血CD4+ CD25+ FoxP3+ Treg细胞/?CD4+细胞亚群比值(30.44﹪?± 4.23﹪? vs 26.06﹪?±4.77﹪,t = 2.365,P = 0.042)、IL-10水平(20.35?ng/?L?±?5.10?ng/?L? vs 16.63?ng/?L±6.26?ng/?L,t = 2.062,P?=?0.046)上升,而IL-2(27.47ng/?L±4.30 ng/?L vs 31.40?ng/?L±5.33 ng/L,t = 2.252,P = 0.015)、TNF-α(41.52?ng/?L±8.32?ng/L vs 46.67?ng/?L±6.71?ng/L,t = 2.157,P = 0.037)和T淋巴细胞miRNA-155表达水平(1.61±0.31 vs 1.89±0.15,t = 3.688,P?= 0.001)则降低。
结论MSCs能够升高肾移植受者外周血CD4+ CD25+ FoxP3+ Treg细胞/?CD4+细胞比值和IL-10水平,降低IL-2、TNF-α和T淋巴细胞miRNA-155表达水平,与MSCs的免疫耐受诱导有关。 相似文献
954.
955.
We present a two-stage hybrid-resolution approach for rigid-body protein-protein docking. The first stage is carried out at low-resolution (15°) angular sampling. In the second stage, we sample promising regions from the first stage at a higher resolution of 6°. The hybrid-resolution approach produces the same results as a 6° uniform sampling docking run, but uses only 17% of the computational time. We also show that the angular distance can be used successfully in clustering and pruning algorithms, as well as the characterization of energy funnels. Traditionally the root-mean-square-distance is used in these algorithms, but the evaluation is computationally expensive as it depends on both the rotational and translational parameters of the docking solutions. In contrast, the angular distances only depend on the rotational parameters, which are generally fixed for all docking runs. Hence the angular distances can be pre-computed, and do not add computational time to the post-processing of rigid-body docking results. 相似文献
956.
Shuang Zhang Hui Yan Chao-Zheng Li Yi-Hong Chen Feng-hua Yuan Yong-gui Chen Shao-Ping Weng Jian-Guo He 《PloS one》2013,8(2)
Leucine-rich repeat flightless-I-interacting protein 2 (LRRFIP2) is a myeloid differentiation factor 88-interacting protein with a positive regulatory function in toll-like receptor signaling. In this study, seven LRRFIP2 protein variants (LvLRRFIP2A-G) were identified in Litopenaeus vannamei. All the seven LvLRRFIP2 protein variants encode proteins with a DUF2051 domain. LvLRRFIP2s were upregulated in hemocytes after challenged with lipopolysaccharide, poly I:C, CpG-ODN2006, Vibrio parahaemolyticus, Staphylococcus aureus, and white spot syndrome virus (WSSV). Dual-luciferase reporter assays in Drosophila Schneider 2 cells revealed that LvLRRFIP2 activates the promoters of Drosophila and shrimp AMP genes. The knockdown of LvLRRFIP2 by RNA interference resulted in higher cumulative mortality of L. vannamei upon V. parahaemolyticus but not S. aureus and WSSV infections. The expression of L. vannamei AMP genes were reduced by dsLvLRRFIP2 interference. These results indicate that LvLRRFIP2 has an important function in antibacterials via the regulation of AMP gene expression. 相似文献
957.
Because of its highly developed social character, zebrafish is a promising model system for the study of the genetic and neurochemical basis of altered social engagement such as is common in autism and schizophrenia. The traditional shoaling paradigm investigates social cohesion in homogeneous groups of zebrafish. However, the social dynamics of mixed groups is gaining interest from a therapeutic point of view and thus warrants animal modeling. Furthermore, mutant zebrafish are not always available in large numbers. Therefore, we developed a new paradigm that allows exploring shoaling in heterogeneous groups. The effects of MK-801, a non-competitive antagonist of the glutamate N-methyl-D-aspartate (NMDA) receptor, on social cohesion were studied to evaluate the paradigm. The drug has previously been shown to mimic aspects of autism and schizophrenia. Our results show that a single MK-801-treated zebrafish reduced social cohesion of the entire shoal drastically. Preliminary observations suggest that the social dynamics of the shoal as a whole was altered. 相似文献
958.
Jun Zhou Desheng Weng Fangjian Zhou Ke Pan Haifeng Song Qijing Wang Huan Wang Hui Wang Yongqiang Li Lixi Huang Huakun Zhang Wei Huang Jianchuan Xia 《Cancer immunology, immunotherapy : CII》2009,58(10):1587-1597
Renal cell carcinoma (RCC) has been shown to be susceptible to immunotherapeutic treatment strategies. In the present study,
patient-derived tumor cells were fused with allogeneic dendritic cells (DC) to elicit anti-tumor activity against RCC. DC
from HLA-A2+ healthy donors were fused with primary RCC cells from ten patients. Phenotype of fusion cells were characterized
by flow cytometer and confocal microscopy. In vitro, T cell proliferation, IFN-γ secretion and cytotocic T lymphocytes (CTL)
activity elicited by allogeneic DC/RCC fusion cells were assessed. Clinically, ten patients were vaccinated with allogeneic
DC/RCC fusion vaccine. The adverse effects and toxicity were observed. The clinical response was evaluated by CT scans. After
fusion, the created hybrids expressed both tumor associated antigen and DC-derived molecules and could stimulate the proliferation
and IFN-γ secretion of T cells as well as elicit strong CTL activity against RCC cells in vitro. In vivo, no serious adverse
effects, toxicity, or signs of autoimmune disease were observed after vaccination therapy. Percentage of T lymphocyte subsets
in peripheral blood of patients was increased significantly. One of ten patients exhibited a partial response with regression
of lung metastases. Six patients showed stable disease with stabilization of previously progressive disease (follow up 1.5 years).
The PR and SD responses, exhibited by 7/10 patients who received the allogeneic DC/RCC fusion vaccine treatment, suggest that
this approach is safe and can elicit immunological responses in a significant portion of patients with RCC.
J. Zhou and D. Weng contributed equally. 相似文献
959.
Immunocytochemical localization of the nervous system, Hatschek's pit and gonads in protochordata was carried out using two specific antibodies against human LH and hCG. The results indicate that there are two different kinds of LH- and hCG-like immunopositive cells in the brain vesicle and nerve tuber of amphioxus, and nerve ganglion in Styela plicata showed immuno-negative reaction to LH and hCG antibodies. At the same time, we found for the first time that LH- and hCG-like immuno-positive cells existed in the early gonads (ovaries and testis) in protochordata. Positive substance distributed in the cytoplasm, nucleoplasm and nucleolar membrane of oogonia as well as early spermatogenic cells in testis. Afterwards, this positive substance was still distributed in the cytoplasmic membrane, cytoplasm, nuclear membrane and nucleoplasm of oocyte during the development and maturation of ovary, and spermatid and spermatozoa showed immuno-negative reaction in testis. These results will provide a new mophological proof that LH and hCG may be directly involved in regulation of the gonadal development and maturation of protochordata. 相似文献
960.
Identification of proteins from feeder conditioned medium that support human embryonic stem cells 总被引:4,自引:0,他引:4
The maintenance of undifferentiated human embryonic stem cells (hESC) requires feeder cells, either in co-culture or feeder-free with conditioned medium (CM) from the feeders. In this study, we compared the CM of a supporting primary mouse embryonic feeder (MEF) and an isogenic but non-supporting MEF line (DeltaE-MEF) in order to gain an insight to the differential expression profile of secreted factors. Using two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time of flight (MALDI) tandem mass spectrometry, 13 protein identities were found to be downregulated in DeltaE-MEF compared to MEF, of which 4 were found to be soluble factors and 3 proteins were membrane-associated or related to the extracellular matrix. In addition, four other proteins were identified to be differentially expressed in MEF-CM using high pressure liquid chromatography (HPLC) and cytokine arrays. In functional experiments where CM was replaced with six of the factors identified, hESC were able to proliferate for five continuous passages whilst maintaining 68-82% and 74-98% expression of pluripotent markers, Oct-4 and Tra-1-60, respectively. Using proteomic tools, important proteins from CM that supports hESC culture have been identified, which when replaced with recombinant proteins, continue to support undifferentiated hESC growth in a feeder-free culture platform. 相似文献