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141.
142.
Zhou Q Li M Wang X Li Q Wang T Zhu Q Zhou X Wang X Gao X Li X 《International journal of biological sciences》2012,8(1):118-123
Breast milk is a complex liquid rich in immunological components that affect the development of the infant's immune system. Exosomes are membranous vesicles of endocytic origin that are found in various body fluids and that can mediate intercellular communication. MicroRNAs (miRNAs), a well-defined group of non-coding small RNAs, are packaged inside exosomes in human breast milk. Here, we identified 602 unique miRNAs originating from 452 miRNA precursors (pre-miRNAs) in human breast milk exosomes using deep sequencing technology. We found that, out of 87 well-characterized immune-related pre-miRNAs, 59 (67.82%) are presented and enriched in breast milk exosomes (P < 10(-16), χ(2) test). In addition, compared with exogenous synthetic miRNAs, these endogenous immune-related miRNAs are more resistant to relatively harsh conditions. It is, therefore, tempting to speculate that these exosomal miRNAs are transferred from the mother's milk to the infant via the digestive tract, and that they play a critical role in the development of the infant immune system. 相似文献
143.
α淀粉酶广泛应用于粮食加工、食品、酿造、发酵、纺织品和医药工业[1].由于固定化酶的优点,国内外研究人员对固定化糖化酶[2,3]和固定化α淀粉酶[4]的制备及在淀粉酶法生产葡萄糖方面的应用作了大量的研究,显示了工业应用前景.然而,迄今为止,用磁性载体固定化α淀粉酶尚未见报道.我们用磁性聚乙二醇胶体粒子作载体,制备出具有磁响应性强、稳定性强、活力高的固定化α淀粉酶.由于具有磁响应性,可借助外部磁场方便简单地回收酶,为该酶工业化生产葡萄糖提供了一种新的途径.而且,由于磁性的优点,也为该酶在食品、医药、纺织… 相似文献
144.
Enhancement of hyperthermia-induced apoptosis by local anesthetics on human histiocytic lymphoma U937 cells 总被引:2,自引:0,他引:2
Arai Y Kondo T Tanabe K Zhao QL Li FJ Ogawa R Li M Kasuya M 《The Journal of biological chemistry》2002,277(21):18986-18993
The combined effects of hyperthermia at 44 degrees C and local anesthetics on apoptosis in human histiocytic lymphoma U937 cells were investigated. When the cells were exposed to hyperthermia for l0 min marginal DNA fragmentation and nuclear fragmentation were observed. In the presence of amide-type local anesthetics further enhancement was found depending on concentration. The order of the concentration required for maximum induction was the reverse order of the lipophilicity (prilocaine > lidocaine > bupivacaine). Western blotting revealed that in hyperthermia there was initial release of Ca(2+) from the intracellular store site as indicated by increased expression of the type 1 inositol-1,4,5-trisphosphate receptor. However, the combination with lidocaine did not induce any further enhancement. Lidocaine enhanced the decrease in ATP content and the increase in intracellular Ca(2+) concentration in individual cells induced by hyperthermia. In addition, superoxide formation, decrease in the mitochondrial membrane potential, and activation of intracellular caspase-3 were found in the cells treated with hyperthermia and lidocaine. All of these were suppressed in part in the presence of the intracellular Ca(2+) ion chelator BAPTA-AM (bis-(O-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl). The present results indicate that local anesthetics at optimal concentrations enhance hyperthermia-induced apoptosis via Ca(2+)- and mitochondria-dependent pathways. Initial release of Ca(2+) from intracellular store sites caused by hyperthermia and followed by the subsequent increase in the intracellular Ca(2+) concentration and the additional activation of the mitochondrial caspase-dependent pathway (partly regulated by intracellular Ca(2+) concentration) plays a crucial role in the enhancement of apoptosis induced by the combination of hyperthermia and lidocaine. 相似文献
145.
Xiaohong Yang Dian Teguh Jian-Ping Wu Bo He Thomas Brett Kirk Shengnan Qin Siming Li Honghui Chen Wei Xue Benjamin Ng Shek Man Chim Jennifer Tickner Jiake Xu 《Arthritis research & therapy》2015,17(1)
IntroductionStructural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population. Protein kinase C delta (PKC-δ) plays versatile functions in cell growth and differentiation, but its role in the articular cartilage and subchondral bone is not known.MethodsHistological analysis including alcian blue, safranin O staining and fluorochrome labeling were used to reveal structural alterations at the articular cartilage surface and bone–cartilage interface in PKC-δ knockout (KO) mice. The morphology and organization of chondrocytes were studied using confocal microscopy. Glycosaminoglycan content was studied by micromass culture of chondrocytes of PKC-δ KO mice.ResultsWe uncovered atypical structural demarcation between articular cartilage and subchondral bone of PKC-δ KO mice. Histology analyses revealed a thickening of the articular cartilage and calcified bone–cartilage interface, and decreased safranin O staining accompanied by an increase in the number of hypertrophic chondrocytes in the articular cartilage of PKC-δ KO mice. Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement. Consistently, in vivo calcein labeling assay showed an increased intensity of calcein labeling in the interface of the growth plate and metaphysis in PKC-δ KO mice. Furthermore, in vitro culture of chondrocyte micromass showed a decreased alcian blue staining of chondrocyte micromass in the PKC-δ KO mice, indicative of a reduced level of glycosaminoglycan production.ConclusionsOur data imply a role for PKC-δ in the osteochondral plasticity of the interface between articular cartilage and the osteochondral junction.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-015-0720-4) contains supplementary material, which is available to authorized users. 相似文献146.
147.
Vibrational optical coherence elastography (OCE) is a promising tool for extracting the mechanical property of soft tissue. Purpose of this study is focusing on settling the optimal frequency range for vibrational OCE with evenly distributed stress filed. A finite element model of 2% agar phantom was built by ANSYS with a vibration stimulation frequency range from 200 to 3000 Hz. Practical experiments were carried out for cross‐validation with the same frequencies and sample. Lateral and horizontal stress filed distributions under different frequencies were mathematically evaluated by coefficient of variance and degree of linearity. Results from simulation and practical experiment cross‐validated each other and 1000 Hz was set as the maximum ideal frequency for vibrational OCE, while the minimum frequency is set by theoretical calculation with a result of 250 Hz. An ex vivo biological sample was utilised to testify performance of vibrational OCE with excitation frequencies in and out of concluded optimal range, which showed that stiffness was better mapped out in optimal frequency range. 相似文献
148.
Methylation protects miRNAs and siRNAs from a 3'-end uridylation activity in Arabidopsis 总被引:5,自引:0,他引:5
Small RNAs of 21-25 nucleotides (nt), including small interfering RNAs (siRNAs) and microRNAs (miRNAs), act as guide RNAs to silence target-gene expression in a sequence-specific manner. In addition to a Dicer homolog, DCL1, the biogenesis of miRNAs in Arabidopsis requires another protein, HEN1. miRNAs are reduced in abundance and increased in size in hen1 mutants. We found that HEN1 is a miRNA methyltransferase that adds a methyl group to the 3'-most nucleotide of miRNAs, but the role of miRNA methylation was unknown. Here, we show that siRNAs from sense transgenes, hairpin transgenes, and transposons or repeat sequences, as well as a new class of siRNAs known as trans-acting siRNAs, are also methylated in vivo by HEN1. In addition, we show that the size increase of small RNAs in the hen1-1 mutant is due to the addition of one to five U residues to the 3' ends of the small RNAs. Therefore, a novel uridylation activity targets the 3' ends of unmethylated miRNAs and siRNAs in hen1 mutants. We conclude that 3'-end methylation is a common step in miRNA and siRNA metabolism and likely protects the 3' ends of the small RNAs from the uridylation activity. 相似文献
149.
Sausan Azzam Daniela Schlatzer David Nethery Dania Saleh Xiaolin Li Afaf Akladious Mark R. Chance Kingman P. Strohl 《Proteomics》2017,17(13-14)
Narcolepsy is a disabling neurological disorder of sleepiness linked to the loss of neurons producing orexin neuropeptides in the hypothalamus. Two well‐characterized phenotypic mouse models of narcolepsy, loss‐of‐function (orexin‐knockout), and progressive loss of orexin (orexin/ataxin‐3) exist. The open question is whether the proteomics signatures of the hypothalamus would be different between the two models. To address this gap, we utilized a label‐free proteomics approach and conducted a hypothalamic proteome analysis by comparing each disease model to that of wild type. Following data processing and statistical analysis, 14 484 peptides mapping to 2282 nonredundant proteins were identified, of which 39 proteins showed significant differences in protein expression across groups. Altered proteins in both models showed commonalties in pathways for mitochondrial dysfunction and neuronal degeneration, as well as altered proteins related to inflammatory demyelination, insulin resistance, metabolic responses, and the dopaminergic and monoaminergic systems. Model‐specific alterations in insulin degraded enzyme (IDE) and synaptosomal‐associated protein‐25 were unique to orexin‐KO and orexin/ataxin‐3, respectively. For both models, proteomics not only identified clinically suspected consequences of orexin loss on energy homeostasis and neurotransmitter systems, but also identified commonalities in inflammation and degeneration despite the entirely different genetic basis of the two mouse models. 相似文献
150.