V2 阿肆呢 声望 11 生物化学与分子生物学 2021-04-15 07:07:12 上传
Hyperphosphorylation and accumulation of neurofilament proteins in Alzheimer disease brain and in okadaic acid-treated SY5Y cells
Abstract We investigated the role of neurofilament (NF) proteins in Alzheimer disease (AD) neurofibrillary degeneration. The levels and degree of phosphorylation of NF proteins in AD neocortex were determined by Western blots developed with a panel of phosphorylation-dependent NF antibodies. Levels of all three NF subunits and the degree of phosphorylation of NF-H and NF-M were significantly increased in AD as compared to Huntington disease brains used as control tissue. The increase in the levels of NF-H and NF-M was 1.7- and 1.5-fold (P<0.01) as determined by monoclonal antibody SMI33, and was 1.6-fold (P<0.01) in NF-L using antibody NR4. The phosphorylation of NF-H and NF-M in AD was increased respectively at the SMI31 epitope by 1.6- and 1.9-fold (P<0.05) and at the SMI33 epitope by 2.7- and 1.3-fold (P<0.01 and P<0.05). Essentially similar effects were observed in SY5Y human neuroblastoma cells when treated with okadaic acid, an inhibitor of protein phosphatase (PP)-2A and -1. This is the first biochemical evidence which unambiguously demonstrates the hyperphosphorylation and the accumulation of NF subunits in AD brain, and shows that the inhibition of PP-2A/PP-1 activities can lead to the hyperphosphorylation of NF-H and NF-M subunits.
V1 阿凯 声望 7 2021-04-15 06:36:02 上传
Mesenchymal stem cells attenuate cardiac fibroblast proliferation and collagen synthesis through paracrine actions
Abstract Mesenchymal stem cells (MSC) transplantation has been shown to decrease fibrosis in the heart; however, whether MSC directly influence the function of cardiac fibroblasts (CFB) remains unknown. MSC-conditioned medium significantly attenuated proliferation of CFB compared with CFB-conditioned medium. MSC-conditioned medium upregulated antiproliferation-related genes such as elastin, myocardin and DNA-damage inducible transcript 3, whereas CFB-conditioned medium upregulated proliferation-related genes such as alpha-2-macrogrobulin and v-kit Hardy–Zuckerman 4 feline sarcoma viral oncogene homolog. MSC-conditioned medium significantly downregulated type I and III collagen expression, and significantly suppressed type III collagen promoter activity. MSC may exert paracrine anti-fibrotic effects at least in part through regulation of CFB proliferation and collagen synthesis.
V3 李程 声望 292 2021-04-15 06:08:27 上传
肘关节置换术后假体周围感染
关节置换是一种能够提高患者生活质量、改善关节功能的手术方式。但是由于肘关节结构复杂,关节置换术后常伴有一些并发症,如假体不稳、尺神经病变、术后感染、异位骨化等。其中术后假体周围感染是关节置换术后最可怕的并发症。对患者而言,这种并发症不仅需要长期住院、多次手术、面对高昂的医疗花费,而且严重时可能会导致截肢或死亡。对医生而言,由于目前相关诊断与治疗缺乏 统一的标准和共识,假体周围感染的临床诊断、治疗仍然面临着严峻的挑战。目前,假体周围感染的研究多数与髋、膝关节感染相关,然而有关肘关节假体周围感染的临床研究较少。现对肘关节假体周围感染的流行病学、诊断、治疗的相关文献作一综述。
V1 Breanne 声望 1 植物生物技术 2021-04-15 06:00:42 上传
Expression of functionally active ATP-sensitive K-channels in insect cells using baculovirus
Abstract We have expressed active ATP-sensitive K-channels (KATP charmels) in Spodoptera frugiperda (Sf9) cells using a baculovirus vector. A high yield of active channels was obtained on co-infection with SUR1 and Kir6.2 engineered to contain N- and/or C-terminal tags to permit detection by Western blotting. Channel activity was sensitive to ATP, glibenclamide and diazoxide. Channel activity was also obtained on expression of a C-terminally truncated Kir6.2 (Kir6.2ΔC26): these channels were blocked by ATP but were insensitive to sulphonylureas. In contrast to Xenopus oocytes and mammalian cells the full length Kir6.2 also gave rise to active channels in Sf9 cells when expressed alone. The highest yield of active KATP channels was obtained on infection with a fusion protein containing SUR1 linked to Kir6.2ΔC26 via a 6-amino acid linker.
V2 徐朋朋 声望 3 动物生物技术 2021-04-15 05:52:47 上传
Phosphoinositide 3-phosphatase segregates from phosphatidylinositol 3-kinase in EGF-stimulated A431 cells and fails to in vitro hydrolyse phosphatidylinositol(3,4,5)trisphosphate
Abstract Beside 4- and 5-phosphatases playing a role in the interconversion between the D-3 phosphorylated polyphosphoinositides, the only enzyme described so far to be responsible for a phosphomonoesterasic activity on the D-3 position of inositol lipids is a specific 3-phosphatase that hydrolyzes PtdIns(3)P in NIH 3T3 cells. We report here the presence of a potent 3-phosphatase activity in different cell types. This activity is detected both in cytosol and membranes of A431 cells and is inhibited by VO43− and Zn2+. Interestingly, the cytosolic activity from A431 cells selectively hydrolyzes in vitro PtdIns(3)P and PtdIns(3,4)P2, whereas PtdIns(3,4,5)P3 remains a very poor substrate under the same conditions. Finally, assays of phosphatidylinositol 3-kinase and 3-phosphatase activities in the pool of phosphotyrosine-containing proteins isolated from EGF-stimulated A431 cells suggest a compartmentation of these two antagonistic activities during cell activation.
V1 刘文彬 声望 2 生物工程 2021-04-15 04:27:59 上传
Cu,Zn-superoxide dismutase is necessary for proper function of VDAC in Saccharomyces cerevisiae cells
Abstract Available data suggest that a copper-and zinc-containing dismutase (CuZnSOD) plays a significant role in protecting eukaryotic cells against oxidative modifications which may contribute to cell aging. Here we demonstrated that depletion of CuZnSOD in Saccharomyces cerevisiae cells (Δsod1 cells) affected distinctly channel activity of VDAC (voltage dependent anion selective channel) and resulted in a moderate reduction in VDAC levels as well as in levels of protein crucial for VDAC import into mitochondria, namely Tob55/Sam50 and Tom40. The observed alterations may result in mitochondriopathy and subsequently in the shortening of the replicative life span observed for S. cerevisiaeΔsod1 cells.
V1 王首锋 声望 1 动植物检疫 2021-04-15 04:09:35 上传
Identification of functional type 1 ryanodine receptors in mouse dendritic cells
Abstract Ca2+ signaling plays an important role in the function of dendritic cells (DC), the specialized antigen-presenting cells of the immune system. Here we describe functional ryanodine receptor (RyR) Ca2+ release channels in murine, bone marrow-derived DC. RT-PCR analysis identified selective expression of the type 1 RyR, with higher levels detected in immature rather than mature DC. The RyR activators caffeine, FK506, ryanodine and 4-chloro-m-cresol mobilized Ca2+ in DC, and responses to 4-chloro-m-cresol were inhibited by dantrolene. Furthermore, activation of RyRs both inhibited subsequent inositol trisphosphate-mediated Ca2+ release and provoked store-operated Ca2+ entry, suggesting a functional interaction between these intracellular Ca2+ channels. Thus, the RyR1 channel may play an intrinsic role in Ca2+ signaling in DC.
V2 王佩瑶 声望 9 遗传学和遗传工程系 2021-04-15 04:04:24 上传
Integrated genome-wide gene expression map and high-resolution analysis of aberrant chromosomal regions in squamous cell lung cancer
Abstract The recognition of recurrent aberrant regions in cancer is important to the discovery of candidate cancer related genes. Here we first constructed a genome-wide gene expression map of squamous lung carcinoma from the Stanford Microarray Database. High-resolution detection of aberrant chromosomal regions was performed by using moving-median method. 84% (27 of 32) of our results were consistent with the previous studies of comparative genomic hybridization or loss of heterozygosity. One overrepresented region in Xq28 was newly discovered to be related to squamous cell lung carcinoma. These observations could be of great interest for further studies.
V1 叶老巫 声望 2 生物科学与生物技术 2021-04-15 03:48:20 上传
Hematopoietic cell-specific adapter proteins, SLP-76 and BLNK, effectively activate NF-AT as well as NF-κB by Syk and Tec PTKs in non-lymphoid cell lines
Abstract To investigate the roles of various hematopoietic cell-specific adapter proteins in T cell receptor (TCR)-signaling leading to nuclear factor of activated T cell (NF-AT) and nuclear factor of κB (NF-κB) activation, we reconstituted TCR-signaling with CD8/ζ, various protein tyrosine kinases (PTKs), and adapter proteins in a non-lymphoid cell line, 293T. We show that SLP-76 and BLNK, but not LAT, effectively co-operated with Syk and Tec family PTKs to activate NF-AT and NF-κB. We also show that Tec family PTKs enhanced endogenous phospholipase C (PLC)-γ1 phosphorylation induced by CD8/ζ and Syk in 293T cells. These results imply that PLC-γ1 may play a critical role in a hematopoietic cell-specific adapter protein-mediated NF-AT and NF-κB activation in a non-lymphoid cell.
V1 纪效波 声望 5 主要研究领域为新能源材料与能源器件 2021-04-15 03:29:23 上传
Effects of lonidamine on the membrane electrical properties of Ehrlich ascites tumor cells
Abstract The effects of lonidamine on membrane electrical properties of Ehrlich ascites tumor cells are investigated. Using a dielectric relaxation technique based on the Maxwell-Wagner effect and elaborated by a ‘single-shell’ fitting procedure, the data indicate that both membrane conductivity and membrane permittivity increase after treatment of these cells with lonidamine while the conductivity of the cytosol remains unchanged. Changes in membrane proteins and/for lipids are suggested which lead to altered membrane structure and/or function.
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