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991.
Chi Zhang Xian-rui Yuan Hao-yu Li Zi-jin ZhaoYi-wei Liao Xiang-yu WangJun Su Shu-shan SangQing Liu 《Biochemical and biophysical research communications》2014
Glutamate-mediated excitotoxicity is involved in many acute and chronic brain diseases. Dynamin related protein 1 (Drp-1), one of the GTPase family of proteins that regulate mitochondrial fission and fusion balance, is associated with apoptotic cell death in cancer and neurodegenerative diseases. Here we investigated the effect of downregulating Drp-1 on glutamate excitotoxicity-induced neuronal injury in HT22 cells. We found that downregulation of Drp-1 with specific small interfering RNA (siRNA) increased cell viability and inhibited lactate dehydrogenase (LDH) release after glutamate treatment. Downregulation of Drp-1 also inhibited an increase in the Bax/Bcl-2 ratio and cleavage of caspase-9 and caspase-3. Drp-1 siRNA transfection preserved the mitochondrial membrane potential (MMP), reduced cytochrome c release, enhanced ATP production, and partly prevented mitochondrial swelling. In addition, Drp-1 knockdown attenuated glutamate-induced increases of cytoplasmic and mitochondrial Ca2+, and preserved the mitochondrial Ca2+ buffering capacity after excitotoxicity. Taken together, these results suggest that downregulation of Drp-1 protects HT22 cells against glutamate-induced excitatory damage, and this neuroprotection may be dependent at least in part on the preservation of mitochondrial function through regulating intracellular calcium homeostasis. 相似文献
992.
Hye-In Kim Fu-Shi Quan Ji-Eun Kim Na-Rae Lee Hyun Ji Kim Su Ji Jo Chae-Min Lee Dae Sik Jang Kyung-Soo Inn 《Biochemical and biophysical research communications》2014
Extracts of Prunella vulgaris have been shown to exert antiestrogenic effects. To identify the compounds responsible for these actions, we isolated the constituents of P. vulgaris and tested their individual antiestrogenic effects. Rosmarinic acid, caffeic acid, ursolic acid (UA), oleanolic acid, hyperoside, rutin and betulinic acid (BA) were isolated from the flower stalks of P. vulgaris var. lilacina Nakai (Labiatae). Among these constituents, UA and BA showed significant antiestrogenic effects, measured as a decrease in the mRNA level of GREB1, an estrogen-responsive protein; the effects of BA were stronger than those of UA. UA and BA were capable of suppressing estrogen response element (ERE)-dependent luciferase activity and expression of estrogen-responsive genes in response to exposure to estradiol, further supporting the suppressive role of these compounds in estrogen-induced signaling. However, neither UA nor BA was capable of suppressing estrogen signaling in cells ectopically overexpressing estrogen receptor α (ERα). Furthermore, both mRNA and protein levels of ERα were reduced by treatment with UA or BA, suggesting that UA and BA inhibit estrogen signaling by suppressing the expression of ERα. Interestingly, both compounds enhanced prostate-specific antigen promoter activity. Collectively, these findings demonstrate that UA and BA are responsible for the antiestrogenic effects of P. vulgaris and suggest their potential use as therapeutic agents against estrogen-dependent tumors. 相似文献
993.
The nematode Caenorhabditis elegans (C. elegans) is an ideal model organism to study the cell fate specification mechanisms during embryogenesis. It is generally believed that cell fate specification in C. elegans is mainly mediated by lineage-based mechanisms, where the specification paths are driven forward by a succession of asymmetric cell divisions. However, little is known about how each binary decision is made by gene regulatory programs. In this study, we endeavor to obtain a global understanding of cell lineage/fate divergence processes during the early embryogenesis of C. elegans. We reanalyzed the EPIC data set, which traced the expression level of reporter genes at single-cell resolution on a nearly continuous time scale up to the 350-cell stage in C. elegans embryos. We examined the expression patterns for a total of 131 genes from 287 embryos with high quality image recordings, among which 86 genes have replicate embryos. Our results reveal that during early embryogenesis, divergence between sister lineages could be largely explained by a few genes. We predicted genes driving lineage divergence and explored their expression patterns in sister lineages. Moreover, we found that divisions leading to fate divergence are associated with a large number of genes being differentially expressed between sister lineages. Interestingly, we found that the developmental paths of lineages could be differentiated by a small set of genes. Therefore, our results support the notion that the cell fate patterns in C. elegans are achieved through stepwise binary decisions punctuated by cell divisions. Our predicted genes driving lineage divergence provide good starting points for future detailed characterization of their roles in the embryogenesis in this important model organism. 相似文献
994.
Zhiwei Xu Perry E. Sheffield Hong Su Xiaoyu Wang Yan Bi Shilu Tong 《International journal of biometeorology》2014,58(2):239-247
Young children are thought to be particularly sensitive to heat waves, but relatively less research attention has been paid to this field to date. A systematic review was conducted to elucidate the relationship between heat waves and children’s health. Literature published up to August 2012 were identified using the following MeSH terms and keywords: “heatwave”, “heat wave”, “child health”, “morbidity”, “hospital admission”, “emergency department visit”, “family practice”, “primary health care”, “death” and “mortality”. Of the 628 publications identified, 12 met the selection criteria. The existing literature does not consistently suggest that mortality among children increases significantly during heat waves, even though infants were associated with more heat-related deaths. Exposure to heat waves in the perinatal period may pose a threat to children’s health. Pediatric diseases or conditions associated with heat waves include renal disease, respiratory disease, electrolyte imbalance and fever. Future research should focus on how to develop a consistent definition of a heat wave from a children’s health perspective, identifying the best measure of children’s exposure to heat waves, exploring sensitive outcome measures to quantify the impact of heat waves on children, evaluating the possible impacts of heat waves on children’s birth outcomes, and understanding the differences in vulnerability to heat waves among children of different ages and from different income countries. Projection of the children’s disease burden caused by heat waves under climate change scenarios, and development of effective heat wave mitigation and adaptation strategies that incorporate other child protective health measures, are also strongly recommended. 相似文献
995.
Guo-Dong Su Deng-Feng Huang Shuang-Yan Han Sui-Ping Zheng Ying Lin 《Applied microbiology and biotechnology》2010,86(5):1493-1501
Two alternative cell-surface display systems were developed in Pichia pastoris using the α-agglutinin and Flo1p (FS) anchor systems, respectively. Both the anchor cell wall proteins were obtained originally
from Saccharomyces cerevisiae. Candida antarctica lipase B (CALB) was displayed functionally on the cell surface of P. pastoris using the anchor proteins α-agglutinin and FS. The activity of CALB displayed on P. pastoris was tenfold higher than that of S. cerevisiae. The hydrolytic and synthetic activities of CALB fused with α-agglutinin and FS anchored on P. pastoris were investigated. The hydrolytic activities of both lipases displayed on yeast cells surface were more than 200 U/g dry
cell after 120 h of culture (200 and 270 U/g dry cell, respectively). However, the synthetic activity of CALB fused with α-agglutinin
on P. pastoris was threefold higher than that of the FS fusion protein when applied to the synthesis of ethyl caproate. Similarly, the CALB
displayed on P. pastoris using α-agglutinin had a higher catalytic efficiency with respect to the synthesis of other short-chain flavor esters than
that displayed using the FS anchor. Interestingly, for some short-chain esters, the synthetic activity of displaying CALB
fused with α-agglutinin on P. pastoris was even higher than that of the commercial CALB Novozyme 435. 相似文献
996.
Khadijeh Bijangi-Vishehsaraei Mohammad Reza Saadatzadeh Su Huang Michael P. Murphy Ahmad R. Safa 《Molecular and cellular biochemistry》2010,342(1-2):133-142
Cellular FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein (c-FLIP) is a major resistance factor for the tumor necrosis factor-related apoptosis-inducing ligand TRAIL and in drug resistance in human malignancies. c-FLIP is an antagonist of caspases-8 and -10, which inhibits apoptosis and is expressed as long (c-FLIPL) and short (c-FLIPS) splice forms. c-FLIP is often overexpressed in various human cancers, including breast cancer. Several studies have shown that silencing c-FLIP by specific siRNAs sensitizes cancer cells to TRAIL and anticancer agents. However, systemic use of siRNA as a therapeutic agent is not practical at present. In order to reduce or inhibit c-FLIP expression, small molecules are needed to allow targeting c-FLIP without inhibiting caspases-8 and -10. We used a small molecule inhibitor of c-FLIP, 4-(4-chloro-2-methylphenoxy)-N-hydroxybutanamide (CMH), and show that CMH, but not its inactive analog, downregulated c-FLIPL and c-FLIPS mRNA and protein levels, caused poly(ADP-ribose) polymerase (PARP) degradation, reduced cell survival, and induced apoptosis in MCF-7 breast cancer cells. These results revealed that c-FLIP is a critical apoptosis regulator that can serve as a target for small molecule inhibitors that downregulate its expression and serve as effective targeted therapeutics against breast cancer cells. 相似文献
997.
Xi-Mei Zhang Qiu-Ming Li Dong-Ju Su Ning Wang Zhi-Yan Shan Lian-Hong Jin Lei Lei 《Molecular biology reports》2010,37(3):1197-1202
Recently, differentiated somatic cells had been reprogrammed to pluripotential state in vitro, and various tissue cells had
been elicited from those cells. Epigenetic modifications allow differentiated cells to perpetuate the molecular memory needed
for the cells to retain their identity. DNA methylation and histone deacetylation are important patterns involved in epigenetic
modification, which take critical roles in regulating DNA expression. In this study, we dedifferentiated NIH/3T3 fibroblasts
by 5-aza-2-deoxycytidine (5-aza-dC) and Trichstatin A (TSA) combination, and detected gene expression pattern, DNA methylation
level, and differentiation potential of reprogrammed cells. As the results, embryonic marker Sox2, klf4, c-Myc and Oct4 were
expressed in reprogrammed NIH/3T3 fibroblasts. Total DNA methylation level was significant decreased after the treatment.
Moreover, exposure of the reprogrammed cells to all trans-retinoic acid (RA) medium elicited the generation of neuronal class
IIIβ-tubulin-positive, neuron-specific enolase (NSE)-positive, nestin-positive, and neurofilament light chain (NF-L)-positive
neural-like cells. 相似文献
998.
Sheng-Yi Lin Chi-Mei Hsueh Sung-Liang Yu Chih-Chung Su Weng-Yoon Shum Kuan-Chuan Yeh Gee-Chen Chang Jeremy J. W. Chen 《Nucleic acids research》2010,38(18):6148-6158
Carcinogenesis is determined based on both cell proliferation and death rates. Recent studies demonstrate that heat shock proteins (HSPs) regulate apoptosis. HLJ1, a member of the DnaJ-like Hsp40 family, is a newly identified tumor suppressor protein closely related to relapse and survival in non-small cell lung cancer (NSCLC) patients. However, its role in apoptosis is currently unknown. In this study, NSCLC cell lines displaying varying HLJ1 expression levels were subjected to ultraviolet (UV) irradiation, followed by flow cytometry. Interestingly, the percentages of apoptotic cells in the seven cell lines examined were positively correlated with HLJ1 expression. Enforcing expression of HLJ1 in low-HLJ1 expressing highly invasive cells promoted UV-induced apoptosis through enhancing JNK and caspase-3 activation in NSCLC. Additionally, UV irradiation led to reduced levels of HLJ1 predominantly in apoptotic cells. The pan-caspase inhibitor, zVAD-fmk and caspase-3-specific inhibitor, DEVD-fmk, prevented UV-induced degradation of HLJ1 by the late stage of apoptosis. Further experiments revealed a non-typical caspase-3 cleavage site (MEID) at amino acid 125–128 of HLJ1. Our results collectively suggest that HLJ1 is a novel substrate of caspase-3 during the UV-induced apoptotic process. 相似文献
999.
Xin Chai Yan-Fang Su Yun-Hui Zheng Shi-Lun Yan Xiao Zhang Xiu-Mei Gao 《Biochemical Systematics and Ecology》2010
A chemical investigation of the roots of Triosteum pinnatifidum led to the isolation of 10 iridoids, elucidated as triohimas A–C, naucledal, secologanin dimethyl acetal, grandifloroside, sweroside, loganin, vogeloside and (E)-aldosecologanin. Most of the compounds were derived from loganin or secologanin with a glucose moiety at C-1 position. The results indicate a close relationship between the two genera Triosteum and Lonicera, and support the viewpoint that the iridoids derived from loganin or secologanin could be the chemotaxonomic markers of the Caprifoliaceae family. 相似文献
1000.
Huaping Lei Yonggang Wang Fengyin Liang Weiwei Su Yifan Feng Xiaoling Guo Ning Wang 《Biochemical Systematics and Ecology》2010
Essential oils were isolated from the leaves of Platycladus orientalis growing in 16 areas of China. The essential oils were analyzed by gas chromatography and gas chromatography-mass spectrometry. In total, 98 volatile compounds were identified. Chemical variability in essential oil composition was evaluated using cluster analysis and principal component analysis. The two analyses led to the identification of four chemotypes: α-pinene, α-pinene/3-carene, cedrol, and cedrol/terpinyl acetate. Geographically, the populations growing in close proximity had similar essential oil composition. The chemical variability could possibly be attributed to genetic and environmental factors. 相似文献