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21.
Zhenwen Cui Zhihong Zhong Yong Yang Baofeng Wang Yuhao Sun Qingfang Sun Guo‐yuan Yang Liuguan Bian 《Journal of biochemical and molecular toxicology》2016,30(8):396-403
Free radical damage caused by ferrous iron is involved in the pathogenesis of secondary brain injury after intracerebral hemorrhage (ICH). NF‐E2‐related factor 2 (Nrf2), a major phase II gene regulator that binds to antioxidant response element, represents an important cellular cytoprotective mechanism against oxidative damage. We hypothesized that Nrf2 might protect astrocytes from damage by Fe2+. Therefore, we examined cytotoxicity in primary astrocytes induced by iron overload and evaluated the effects of Fe2+ on Nrf2 expression. The results demonstrated that 24‐h Fe2+ exposure exerted time‐ and concentration‐dependent cytotoxicity in astrocytes. Furthermore, Fe2+ exposure in astrocytes resulted in time‐ and concentration‐dependent increases in Nrf2 expression, which preceded Fe2+ toxicity. Nrf2‐specific siRNA further knocked down Nrf2 levels, resulting in greater Fe2+‐induced astrocyte cytotoxicity. These data indicate that induction of Nrf2 expression could serve as an adaptive self‐defense mechanism, although it is insufficient to completely protect primary astrocytes from Fe2+‐induced neurotoxicity. 相似文献
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Zhi Qian Zeyuan Zhong Shuo Ni Dejian Li Fangxue Zhang Ying Zhou Zhanrong Kang Jun Qian Baoqing Yu 《Journal of cellular and molecular medicine》2020,24(17):10112-10127
Postmenopausal Osteoporosis (PMOP) is oestrogen withdrawal characterized of much production and activation by osteoclast in the elderly female. Cytisine is a quinolizidine alkaloid that comes from seeds or other plants of the Leguminosae (Fabaceae) family. Cytisine has been shown several potential pharmacological functions. However, its effects on PMOP remain unknown. This study designed to explore whether Cytisine is able to suppress RANKL‐induced osteoclastogenesis and prevent the bone loss induced by oestrogen deficiency in ovariectomized (OVX) mice. In this study, we investigated the effect of Cytisine on RAW 264.7 cells and bone marrow monocytes (BMMs) derived osteoclast culture system in vitro and observed the effect of Cytisine on ovariectomized (OVX) mice model to imitate postmenopausal osteoporosis in vivo. We found that Cytisine inhibited F‐actin ring formation and tartrate‐resistant acid phosphatase (TRAP) staining in dose‐dependent ways, as well as bone resorption by pit formation assays. For molecular mechanism, Cytisine suppressed RANK‐related trigger RANKL by phosphorylation JNK/ERK/p38‐MAPK, IκBα/p65‐NF‐κB, and PI3K/AKT axis and significantly inhibited these signalling pathways. However, the suppression of PI3K‐AKT‐NFATc1 axis was rescued by AKT activator SC79. Meanwhile, Cytisine inhibited RANKL‐induced RANK‐TRAF6 association and RANKL‐related gene and protein markers such as NFATc1, Cathepsin K, MMP‐9 and TRAP. Our study indicated that Cytisine could suppress bone loss in OVX mouse through inhibited osteoclastogenesis. All data provide the evidence that Cytisine may be a promising agent in the treatment of osteoclast‐related diseases such as osteoporosis. 相似文献
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The construction of inulin-assimilating and sorbitol-producing fusants was achieved by intergeneric protoplast fusion between Kluyveromyces sp. Y-85 and Saccharomyces cerevisiae E-15. The cells of parental strains were pretreated with 0.1% EDTA (w/v) and 2-mercaptoethanol (0.1%, v/v) and then exposed to 2.0% (w/v) Zymolase at 30 °C for 30–40 min. The optimized fusion condition demonstrated that with the presence of 30% (w/v) polyethylene glycol 6000 (PEG-6000) and 10 mM CaCl2 for 30 min, the fusion frequency reached 2.64 fusants/106 parental cells. The fusants were screened by different characters between two parental strains and further identified by DNA contents, inulinase activity and sorbitol productivity. One of the genetically stable fusants, Strain F27, reached a maximal sorbitol production of 4.87 g/100 ml under optimal fermentation condition. 相似文献
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Marino R Thuraisingam T Camateros P Kanagaratham C Xu YZ Henri J Yang J He G Ding A Radzioch D 《Journal of immunology (Baltimore, Md. : 1950)》2011,186(7):4433-4442
Secretory leukocyte protease inhibitor (SLPI) is an anti-inflammatory protein that is observed at high levels in asthma patients. Resiquimod, a TLR7/8 ligand, is protective against acute and chronic asthma, and it increases SLPI expression of macrophages in vitro. However, the protective role played by SLPI and the interactions between the SLPI and resiquimod pathways in the immune response occurring in allergic asthma have not been fully elucidated. To evaluate the role of SLPI in the development of asthma phenotypes and the effect of resiquimod treatment on SLPI, we assessed airway resistance and inflammatory parameters in the lungs of OVA-induced asthmatic SLPI transgenic and knockout mice and in mice treated with resiquimod. Compared with wild-type mice, allergic SLPI transgenic mice showed a decrease in lung resistance (p < 0.001), airway eosinophilia (p < 0.001), goblet cell hyperplasia (p < 0.001), and plasma IgE levels (p < 0.001). Allergic SLPI knockout mice displayed phenotype changes significantly more severe compared with wild-type mice. These phenotypes included lung resistance (p < 0.001), airway eosinophilia (p < 0.001), goblet cell hyperplasia (p < 0.001), cytokine levels in the lungs (p < 0.05), and plasma IgE levels (p < 0.001). Treatment of asthmatic transgenic mice with resiquimod increased the expression of SLPI and decreased inflammation in the lungs; resiquimod treatment was still effective in asthmatic SLPI knockout mice. Taken together, our study showed that the expression of SLPI protects against allergic asthma phenotypes, and treatment by resiquimod is independent of SLPI expression, displayed through the use of transgenic and knockout SLPI mice. 相似文献
27.
Relationship of stigma behaviors and breeding system in three Mazus (Phrymaceae) species with bilobed stigma 下载免费PDF全文
Sensitive stigma has been recognized to facilitate outcrossing. We hypothesized that species with different levels of sensitivity might have corresponding differences in components of their breeding system. In this study, three Mazus species with bilobed stigmas were used to test the hypothesis. We explored stigma behaviors of the species in reaction time, recovery time, permanent closing time, and the minimum pollen load causing permanent closure. We investigated floral traits, pollinator type and behavior, pollination intensity, and natural schedule of pollen deposition on stigma. Moreover, we evaluated the mating system of the species by checking seed set after controlled pollination treatments, namely, natural flowers with open pollination, enclosed flowers without pollination, and enclosed flowers with self and outcross hand pollination. Results indicated that stigma of M. pumilus (N. L. Burman) Steenis was not sensitive, whereas stigmas of M. miquelii Makino and M. stachydifolius (Turcz.) Maxim. closed and reopened quickly in response to pollination. Accordingly, hand pollination treatments revealed that seed set of self-spontaneous pollination in M. pumilus was similar to the other treatments. For M. miquelii, outcross pollen resulted in significantly higher seed set than self-pollen.Mazus stachydifolius was self-incompatible. Additionally, the corresponding characteristics in other components of the breeding system for each species were found. Our study indicated that the sensitivity of bilobed stigma might be linked with floral traits and the mating system in a given species. Sensitive stigma should be regarded as an evolutionary mechanism for enhancement of outcrossing. 相似文献
28.
Xiao‐Yan Xu Zhong‐Jie Ding Lei Chen Jin‐Ying Yan Gui‐Xin Li Shao‐Jian Zheng 《植物学报(英文版)》2015,57(10):848-858
Cadmium (Cd) is one of the most toxic elements and can be accumulated in plants easily; meanwhile, eIF5A is a highly conserved protein in all eukaryotic organisms. The present work tried to investigate whether eIF5A is involved in Cd accumulation and sensitivity in Arabidopsis (Arabidopsis thaliana L.) by comparing the wild‐type Columbia‐0 (Col‐0) with a knockdown mutant of AteIF5A‐2, fbr12‐3 under Cd stress conditions. The results showed that the mutant fbr12‐3 accumulated more Cd in roots and shoots and had significantly lower chlorophyll content, shorter root length, and smaller biomass, suggesting that downregulation of AteIF5A‐2 makes the mutant more Cd sensitive. Real‐time polymerase chain reaction revealed that the expressions of metal transporters involved in Cd uptake and translocation including IRT1, ZIP1, AtNramp3, and AtHMA4 were significantly increased but the expressions of PCS1 and PCS2 related to Cd detoxification were decreased notably in fbr12‐3 compared with Col‐0. As a result, an increase in MDA and H2O2 content but decrease in root trolox, glutathione and proline content under Cd stress was observed, indicating that a severer oxidative stress occurs in the mutant. All these results demonstrated for the first time that AteIF5A influences Cd sensitivity by affecting Cd uptake, accumulation, and detoxification in Arabidopsis. 相似文献
29.
Guang-Jin Zhou Yue Zhang Jian Wang Jin-Hu Guo Jun Ni Zhao-Ming Zhong Li-Qun Wang Yong-Jun Dang Jian-Feng Dai Long Yu 《DNA sequence》2004,15(3):219-224
Present work reported the cloning and characterization of a human novel RNA binding gene Partner of NOB1 (PNO1), with a length of 1637bp and a putative open reading frame of 759 bp, isolated from human kidney. It is composed of seven exons and is localized on chromosome 2p14. Western blot showed that the molecular weight of PNO1 is about 35kDa. RT-PCR results in 16 human tissues indicated that PNO1 is expressed mainly in liver, lung, spleen and kidney, slightly in thymus, testis, ovary, respectively, but not in heart, brain, skeletal muscle, placenta, pancreas, prostate, small intestine, colon and peripheral blood leukocytes. GFP fusion expression in mammalian cells exhibited its localization in the nucleus, especially in nucleoli. Subcellular localization of thirteen GFP fusion PNO1 deletion proteins showed that the region of 92-230 aa is solely responsible for its nucleolar retention, and KH domain alone is not sufficient for nucleolar retention. The PNO1 family shows significant conservation in both eukaryotes and prokaryotes. 相似文献
30.
Species in the genus Oryza (Poaceae) contain 10 genomic types and are distributed in pan-tropics of the world. To explore phylogenetic relationships
of Oryza species having the AA-genome, DNA sequences of the chloroplast trnL intron and trnL-trnF spacer, mitochondrial nad1 intron 2, and nuclear internal transcribed spacer were analyzed, based on materials from 6 cultivated (O. sativa and O. glaberrima) and 13 wild accessions, in addition to a CC-genome species (O. officinalis) that was used as an outgroup. Analyses of the combined sequence data set from different sources provide a much better resolution
of the AA-genome species than the individual data set, indicating the limitation of a single gene in phylogenetic reconstruction.
The phylogeny based on the combined data set demonstrated an apparent grouping of the AA-genome Oryza species that was well associated with their geographic origin, although the Australian O. meridionalis showed its affinity with the African species. The geographic pattern of the phylogenetic relationship was probably attributed
to the frequent genetic exchange and introgression among the AA-genome species from the same continents. In addition, Asian
cultivated rice O. sativa showed its close relation to O. rufipogon and O. nivara, whereas African cultivated rice O. glaberrima was closely linked to O. barthii and O. longistaminata, indicating the independent domestication of the two cultivated species in different geographic locations. 相似文献