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211.
Yating Wang Jun Wang Ding Bai Jinlin Song Rui Ye Zhihe Zhao Lei Lei Jin Hao Chunmiao Jiang Shanbao Fang Shu An Qian Cheng Juan Li 《Journal of cellular physiology》2013,228(9):1935-1942
The presence of an appropriate number of viable cells is prerequisite for successive differentiation during chondrogenesis. Chondrogenic differentiation has been reported to be influenced by mechanical stimuli. This research aimed to study the effects of cyclic compressive stress on cell viability of rat bone marrow‐derived MSCs (BMSCs) during chondrogenesis as well as its underlying mechanisms. The results showed that dynamic compression increased cell quantity and viability remarkably in the early stage of chondrogenesis, during which the expression of Ihh, Cyclin D1, CDK4, and Col2α1 were enhanced significantly. Possible signal pathways implicated in the process were explored in our study. MEK/ERK and p38 MAPK were not found to function in this process while BMP signaling seemed to play an important role in the mechanotransduction during chondrogenic proliferation. In conclusion, dynamic compressive stress could enhance cell viability during chondrogenesis, which might be achieved by activating BMP signaling. J. Cell. Physiol. 228: 1935–1942, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
212.
Can Chen Yi Wang Sally S. L. Goh Jing Yang Dang Hoang Lam Yukti Choudhury Felix Chang Tay Shouhui Du Wee Kiat Tan Yovita Ida Purwanti Weimin Fan Shu Wang 《Journal of neurochemistry》2013,126(3):318-330
The breakthrough in derivation of human‐induced pluripotent stem cells (hiPSCs) provides an approach that may help overcome ethical and allergenic challenges posed in numerous medical applications involving human cells, including neural stem/progenitor cells (NSCs). Considering the great potential of NSCs in targeted cancer gene therapy, we investigated in this study the tumor tropism of hiPSC‐derived NSCs and attempted to enhance the tropism by manipulation of biological activities of proteins that are involved in regulating the migration of NSCs toward cancer cells. We first demonstrated that hiPSC‐NSCs displayed tropism for both glioblastoma cells and breast cancer cells in vitro and in vivo. We then compared gene expression profiles between migratory and non‐migratory hiPSC‐NSCs toward these cancer cells and observed that the gene encoding neuronal nitric oxide synthase (nNOS) was down‐regulated in migratory hiPSC‐NSCs. Using nNOS inhibitors and nNOS siRNAs, we demonstrated that this protein is a relevant regulator in controlling migration of hiPSC‐NSCs toward cancer cells, and that inhibition of its activity or down‐regulation of its expression can sensitize poorly migratory NSCs and be used to improve their tumor tropism. These findings suggest a novel application of nNOS inhibitors in neural stem cell‐mediated cancer therapy. 相似文献
213.
Zhong‐Fei Ni Zhi‐Wei Ma Ao‐Ji Xie Xiang‐Shu Cheng Qun Wang Jian‐Zhi Wang Gong‐Ping Liu 《Journal of neurochemistry》2013,124(3):388-396
Hyperhomocysteinemia (Hhcy) may induce memory deficits with β‐amyloid (Aβ) accumulation and tau hyperphosphorylation. Simultaneous supplement of folate and vitamin B12 partially restored the plasma homocysteine level and attenuated tau hyperphosphorylation, Aβ accumulation and memory impairments induced by Hhcy. However, folate and vitamin B12 treatment have no effects on Hhcy which has the methylenetetrahydrofolate reductase genotype mutation. In this study, we investigated the effects of simultaneous supplement of betaine on Alzheimer‐like pathological changes and memory deficits in hyperhomocysteinemic rats after a 2‐week induction by vena caudalis injection of homocysteine (Hcy). We found that supplementation of betaine could ameliorate the Hcy‐induced memory deficits, enhance long‐term potentiation (LTP) and increase dendritic branches numbers and the density of the dendritic spines, with up‐regulation of NR1, NR2A, synaptotagmin, synaptophysin, and phosphorylated synapsin I protein levels. Supplementation of betaine also attenuated the Hcy‐induced tau hyperphosphorylation at multiple AD‐related sites through activation protein phosphatase‐2A (PP2A) with decreased inhibitory demethylated PP2AC at Leu309 and phosphorylated PP2AC at Tyr307. In addition, supplementation of betaine also decreased Aβ production with decreased presenilin‐1 protein levels. Our data suggest that betaine could be a promising candidate for arresting Hcy‐induced AD‐like pathological changes and memory deficits. 相似文献
214.
215.
Jing Yang Chao Wang Chang Shu Li Liu Jianing Geng Songnian Hu Jie Feng 《Microbial ecology》2013,65(4):975-981
The ocean is a natural habitat for antibiotic-producing bacteria, and marine aquaculture introduces antibiotics into the ocean to treat infections and improve aquaculture production. Studies have shown that the ocean is an important reservoir of antibiotic resistance genes. However, there is a lack of understanding and knowledge about the clinical importance of the ocean resistome. We investigated the relationship between the ocean bacterial resistome and pathogenic resistome. We applied high-throughput sequencing and metagenomic analyses to explore the resistance genes in bacterial plasmids from marine sediments. Numerous putative resistance determinants were detected among the resistance genes in the sediment bacteria. We also found that several contigs shared high identity with transposons or plasmids from human pathogens, indicating that the sediment bacteria recently contributed or acquired resistance genes from pathogens. Marine sediment bacteria could play an important role in the global exchange of antibiotic resistance. 相似文献
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217.
Qiang Hao Weina Li Cun Zhang Xin Qin Xiaochang Xue Meng Li Zhen Shu Tianjiao Xu Yujin Xu Weihua Wang Wei Zhang Yingqi Zhang 《Biochemical and biophysical research communications》2013,430(1):436-441
Controversial roles of FOXP3 in different cancers have been reported previously, while its role in gastric cancer is largely unknown. Here we found that FOXP3 is unexpectedly upregulated in some gastric cancer cells. To test whether increased FOXP3 remains the tumor suppressor role in gastric cancer as seen in other cancers, we test its function in cell proliferation both at basal and TNFα mimicked inflammatory condition. Compared with the proliferation inhibitory role observed in basal condition, FOXP3 is insufficient to inhibit the cell proliferation under TNFα treatment. Molecularly, we found that TNFα induced an interaction between FOXP3 and p65, which in turn drive the FOXP3 away from the promoter of the well known target p21. Our data here suggest that although FOXP3 is upregulated in gastric cancer, its tumor suppressor role has been dampened due to the inflammation environment. 相似文献
218.
Xiao Wang Zhong-Wei Zhang Shi-Hua Tu Wen-Qiang Feng Fei Xu Feng Zhu Da-Wei Zhang Jun-Bo Du Shu Yuan Hong-Hui Lin 《Biologia》2013,68(1):74-81
Cadmium (Cd) has been identified as a significant pollutant due to its high solubility in water and soil and high toxicity to plants and animals. Rice, as one of the most important food crops, is grown in soils with variable levels of Cd and therefore, is important to discriminate the Cd tolerance of different rice cultivars to determine their suitability for cultivation in Cd-contaminated soils. This study investigates the primary mechanisms employed by four rice cultivars in attaining Cd tolerance. HA63 cultivar reduces Cd uptake by increasing Fe absorption through activation of phytosiderophores. T3028 cultivar accumulates the highest level of Cd in leaves while also activating its reactive oxygen species (ROS) scavenging system, including antioxidant enzymes and phytochelatins. In some rice cultivars (such as HA63), a cyanide-resistant respiration mechanism, important in Cd detoxification, was also promoted under the Cd stress. In conclusion, different rice cultivars may adopt different biochemical strategies and respond with different efficiency to Cd stress. 相似文献
219.
Restoration of a subtropical eutrophic shallow lake in China: effects on nutrient concentrations and biological communities 总被引:1,自引:0,他引:1
Disturbances caused by rainfall are common in streams with the impact on stream inhabitants determined by the frequency, intensity, and predictability of the event. Here, we examine the response of winter-emerging Chironomidae (Diptera) to extreme flooding disturbance. In August of 2007, a severe flood impacted southeastern Minnesota, imparting stress on aquatic communities. Chironomid pupal exuviae collections were obtained biweekly from 18 southeast Minnesota streams during the following winter to assess resistance and resilience of winter-active chironomids to flooding. Streams examined were divided into moderate (2.5–10 cm), heavy (10–20 cm), or extreme (20+ cm) rainfall categories with rainfall amounts in each category representing total precipitation during the 3-day storm. Post-flood samples were compared to samples obtained from the same localities during prior winters. Our findings contradict studies of responses by Chironomidae to flooding during warmer-water conditions and show that winter-emerging Chironomidae are resistant to stress imposed by summer spates. Significantly more taxa emerged during winter after flooding as compared to historic collections, and the number of species emerging in winter was positively correlated with rainfall severity, indicating that 15 species responded opportunistically to disturbance. This indicates that winter-active Chironomidae may be resistant to increased severity of summer spates associated with climate change predictions. 相似文献
220.
Tian-Xing Shi Shu Wang Ke-Wu Zeng Peng-Fei Tu Yong Jiang 《Bioorganic & medicinal chemistry letters》2013,23(21):5904-5908
Five new phenolic glycosides, tenuisides A–E (1?5), and a new megastigmane glycoside, tenuiside F (6), along with seventeen known compounds (7–23) were isolated from the aerial parts of Polygala tenuifolia Willd. Their structures were established by detailed analysis of NMR and HRESIMS spectroscopic data, and the absolute configurations of compounds 5 and 6 were determined by CD spectra and in-NMR-tube Mosher’s method. The inhibitory effects of these compounds were evaluated on NO production in LPS-activated BV-2 microglia cells. Compound 17 showed the strongest activity, with an IC50 value of 7.4 μM, while compounds 1, 8, 14, and 18 showed the moderate activities, with IC50 values of 16.2–38.5 μM. And their primary structure–activity relationships (SARs) of NO inhibitory effects were also briefly discussed. 相似文献