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111.
Nie L Feng W Diaz R Gratton MA Doyle KJ Yamoah EN 《The Journal of biological chemistry》2005,280(15):15097-15102
L-Alpha-difluoromethylornithine (DFMO) is a chemopreventive agent for colon cancer in clinical trials. Yet, the drug produces an across-frequency elevation of the hearing threshold, suggesting that DFMO may affect a common trait along the cochlear spiral. The mechanism for the ototoxic effects of DFMO remains uncertain. The cochlear duct is exclusively endowed with endocochlear potential (EP). EP is a requisite for normal sound transduction, as it provides the electromotive force that determines the magnitude of the receptor potential of hair cells. EP is generated by the high throughput of K(+) across cells of the stria vascularis, conferred partly by the activity of Kir4.1 channels. Here, we show that the ototoxicity of DFMO may be mediated by alteration of the inward rectification of Kir4.1 channels, resulting in a marked reduction in EP. These findings are surprising given that the present model for EP generation asserts that Kir4.1 confers the outflow of K(+) in the stria vascularis. We have proposed an alternative model. These findings should also enable the rational design of new pharmaceuticals devoid of the untoward effect of DFMO. 相似文献
112.
Evelin Ramóna Péli Nie Lei Tamás Pócs Zsanett Laufer Stefan Porembski Zoltán Tuba 《Central European Journal of Biology》2011,6(5):838-849
In our present studies, the recovery of photosynthetic activity after rehydration was demonstrated. We measured chlorophyll
fluorescence, CO2 gas exchange and the pigment composition in the previously long-term air-dried cryptogamic inselberg crusts collected from
two tropical areas. The cryptobiotic crusts were collected from different localities on similar ecological and climatic conditions
from extreme habitats of inselbergs (outcrops). These inselbergs are characterized by a dry microclimate and are covered by
scarce soil. We found that the ecophysiological responses of both cryptogamic inselberg crusts showed an extremely high degree
of desiccation-tolerance due to the fast and full recovery during rehydration. The photosynthetic activity of the cryptobiotic
crusts were restored and regained within 15 and 40 min, respectively, after rehydration. Photosynthetic activity of the crusts
was retained at all applied light intensities when enough water was available, however the degree of the recovery was different
between the crusts. Photosynthetic pigment contents were strongly and positively correlated with water content. Our results
indicated that tropical desiccation-tolerant cryptogamic crusts found on inselberg rock surfaces have CO2 fixation ability in the range of cyanobacteria and lichens, suggesting that at a global scale they can assimilate CO2 in a significant amount. 相似文献
113.
Jianping Liu Bo Nie Boling Yu Feiyun Xu Qian Zhang Ya Wang Weifeng Xu 《Plant biotechnology journal》2023,21(8):1590-1610
Ubc13 is required for Lys63-linked polyubiquitination and innate immune responses in mammals, but its functions in plant immunity still remain largely unknown. Here, we used molecular biological, pathological, biochemical, and genetic approaches to evaluate the roles of rice OsUbc13 in response to pathogens. The OsUbc13-RNA interference (RNAi) lines with lesion mimic phenotypes displayed a significant increase in the accumulation of flg22- and chitin-induced reactive oxygen species, and in defence-related genes expression or hormones as well as resistance to Magnaporthe oryzae and Xanthomonas oryzae pv oryzae. Strikingly, OsUbc13 directly interacts with OsSnRK1a, which is the α catalytic subunit of SnRK1 (sucrose non-fermenting-1-related protein kinase-1) and acts as a positive regulator of broad-spectrum disease resistance in rice. In the OsUbc13-RNAi plants, although the protein level of OsSnRK1a did not change, its activity and ABA sensitivity were obviously enhanced, and the K63-linked polyubiquitination was weaker than that of wild-type Dongjin (DJ). Overexpression of the deubiquitinase-encoding gene OsOTUB1.1 produced similar effects with inhibition of OsUbc13 in affecting immunity responses, M. oryzae resistance, OsSnRK1a ubiquitination, and OsSnRK1a activity. Furthermore, re-interfering with OsSnRK1a in one OsUbc13-RNAi line (Ri-3) partially restored its M. oryzae resistance to a level between those of Ri-3 and DJ. Our data demonstrate OsUbc13 negatively regulates immunity against pathogens by enhancing the activity of OsSnRK1a. 相似文献
114.
Buer Song Lifei Nie Khurshed Bozorov Chao Niu Rustamkhon Kuryazov Haji Akber Aisa Jiangyu Zhao 《化学与生物多样性》2023,20(3):e202201059
The chemical transformation of the tricyclic furo[2,3-d]pyrimidines was performed under isosteric and scaffold-hopping strategies focusing on the synthesis of its arylidene and imine-containing derivatives. Naturally-occurring alkaloids mackinazolinone and isaindigotone were as templates of target heterocycles. Synthesized compounds evaluated for their antitumor activity on human cancer cervical HeLa, breast MCF-7, and colon HT-29 cell lines. Four compounds: 8c , 8e , 10b , and 10c demonstrated potency against HeLa and HT-29 cell lines, and IC50 values were between 7.37–13.72 μM, respectively. The molecular docking results showed that compounds 8c and 10b had good binding and high matching with the target EGFR protein. 相似文献
115.
Yong-Gang Nie Ze-Jun Zhang Ronald R. Swaisgood Fu-Wei Wei 《European Journal of Wildlife Research》2012,58(1):235-241
In the first-ever study of reproductive endocrinology in wild male giant pandas (Ailuropoda melanoleuca), we provide new insights into the reproductive ecology of the species. We tracked and observed pandas in Foping Nature Reserve
of the Qinling Mountains for 3 years, collecting fecal samples for testosterone metabolite analysis and data on reproductive
activity. Males encountered multiple potential mates and competed for reproductive access to females. Male testosterone metabolites
increased in February, peaked in March and April, and fell back to baseline after the mating season. However, males did not
maintain a high testosterone level throughout the mating season. Male testosterone instead peaked during encounters with potential
mates and declined between encounters. These results indicate that testicular activity is typically dormant until mobilized
by interactions with females and potentially by interactions with male competitors. This suggests that male pandas may be
energetically constrained, elevating testosterone levels only when necessary to meet the demands of intrasexual competition
and courtship and fertilization of females. Maintaining a high testosterone level is metabolically expensive and male pandas
enter the mating season during a period of low food availability. If this hypothesis is correct, male panda body condition
may be an important determinant of reproductive outcome, and anthropogenic activities that diminish foraging resources may
have significant impacts on the mating ecology of the species, affecting its conservation. 相似文献
116.
Tian L Branford-White C Wang W Nie H Zhu L 《International journal of biological macromolecules》2012,50(3):782-787
This study evaluates the bleaching efficiency of the hydrogen peroxide bleaching process combined with laccase-mediated system pretreatment (LMS-HPBP) in the treatment of scoured cotton fabric. By changing the factors of laccase-mediated system pretreatment and the hydrogen peroxide bleaching process and examining the subsequent whiteness value and retained tensile strength of the samples, we find three LMS-HPBP processes that are more environment friendly than the conventional hydrogen peroxide bleaching process (CHPBP): (i) bleaching with lower dosage of hydrogen peroxide; (ii) bleaching at reduced temperature; (iii) bleaching for shortened duration. Whiteness, retained tensile strength and K/S values of cotton fabric samples treated by i-iii processes were similar to or higher than those by CHPBP. X-ray diffraction (XRD) analysis also demonstrated that the three processes rendered fabric of both lower crystallinity and bigger crystallite size than those by CHPBP. In addition, the "green" short-flow process was developed to treat cotton fabric and the results obtained shows this method is feasible as a new energy-saving process. 相似文献
117.
Exposure to ionizing radiation may induce a heritable genomic instability phenotype that results in a persisting and enhanced genetic and functional change among the progeny of irradiated cells. Since radiation-induced bystander effects have been demonstrated with a variety of biological end points under both in vitro and in vivo conditions, this raises the question whether cytoplasmic irradiation or the radiation-induced bystander effect can also lead to delayed genomic instability. In the present study, we used the Radiological Research Accelerator Facility charged-particle microbeam for precise nuclear or cytoplasmic irradiation. The progeny of irradiated and the bystander human hamster hybrid (A(L)) cells were analyzed using multicolor banding (mBAND) to examine persistent chromosomal changes. Our results showed that the numbers of metaphase cells involving changes of human chromosome 11 (including rearrangement, deletion and duplication) were significantly higher than that of the control in the progeny of both nuclear and cytoplasmic targeted cells. These chromosomal changes could also be detected among the progeny of bystander cells. mBAND analyses of clonal isolates from nuclear and cytoplasm irradiations as well as the bystander cell group showed that chromosomal unstable clones were generated. Analyses of clonal stability after long-term culture indicated no significant change in the number of unstable clones for the duration of culture in each irradiated group. These results suggest that genomic instability that is manifested after ionizing radiation exposure is not dependent on direct damage to the cell nucleus. 相似文献
118.
119.
Ze Yu Hao Wang Yilin Fang Liangliang Lu Minghao Li Bingru Yan Yuzhe Nie Chunbo Teng 《Journal of cellular biochemistry》2020,121(3):2318-2329
Heat shock proteins (HSPs) were known as the molecular chaperones, which play a pivotal role in the protein quality control system, ensuring correct folding of proteins, and facilitating the correct refolding of damaged proteins via the transient interaction with their substrate proteins. They also practice in the regulation of cell cycles and are involved in apoptosis. We found that HspB2 was almost completely silent in pancreatic cancer and few studies investigated the role of HspB2 in cancer cells, particularly in pancreatic cancer. Here, we reported that HspB2 effectively inhibited cell proliferation in Panc-1 cells. Specifically, we demonstrated that HspB2 could combine mut-p53 and change the DNA binding site of mutant p53, subsequently upregulated the expression of RPRM, BAI-1, and TSAP6 which were the downstream genes of wt-p53, participate in mediating downstream responses to p53, including inhibiting cell proliferation and angiogenesis. The main aim of this study is to investigate the relationship between HspB2 and p53, and provide a novel treatment strategy for pancreatic cancer. 相似文献
120.