排序方式: 共有159条查询结果,搜索用时 537 毫秒
81.
Miriam Kolko Fia Vosborg Ulrik L. Henriksen Md Mahdi Hasan-Olive Elisabeth Holm Diget Rupali Vohra Iswariya Raja Sridevi Gurubaran Albert Gjedde Shelton Tendai Mariga Dorte M. Skytt Tor Paaske Utheim Jon Storm-Mathisen Linda H. Bergersen 《Neurochemical research》2016,41(6):1229-1236
In retina, like in brain, lactate equilibrates across cell membranes via monocarboxylate transporters and in the extracellular space by diffusion, forming a basis for the action of lactate as a transmitter of metabolic signals. In the present paper, we argue that the lactate receptor GPR81, also known as HCAR1, may contribute importantly to the control of retinal cell functions in health and disease. GPR81, a G-protein coupled receptor, is known to downregulate cAMP both in adipose and nervous tissue. The receptor also acts through other down-stream mechanisms to control functions, such as excitability, metabolism and inflammation. Recent publications predict effects of the lactate receptor on neurodegeneration. Neurodegenerative diseases in retina, where the retinal ganglion cells die, notably glaucoma and diabetic retinopathy, may be linked to disturbed lactate homeostasis. Pilot studies reveal high GPR81 mRNA in retina and indicate GPR81 localization in Müller cells and retinal ganglion cells. Moreover, monocarboxylate transporters are expressed in retinal cells. We envision that lactate receptors and transporters could be useful future targets of novel therapeutic strategies to protect neurons and prevent or counteract glaucoma as well as other retinal diseases. 相似文献
82.
Vijay Sadashivaiah Pierre Sacré Yun Guan William S. Anderson Sridevi V. Sarma 《Journal of computational neuroscience》2018,45(3):193-206
Electrical stimulation of nerve fibers is used as a therapeutic tool to treat neurophysiological disorders. Despite efforts to model the effects of stimulation, its underlying mechanisms remain unclear. Current mechanistic models quantify the effects that the electrical field produces near the fiber but do not capture interactions between action potentials (APs) initiated by stimulus and APs initiated by underlying physiological activity. In this study, we aim to quantify the effects of stimulation frequency and fiber diameter on AP interactions involving collisions and loss of excitability. We constructed a mechanistic model of a myelinated nerve fiber receiving two inputs: the underlying physiological activity at the terminal end of the fiber, and an external stimulus applied to the middle of the fiber. We define conduction reliability as the percentage of physiological APs that make it to the somatic end of the nerve fiber. At low input frequencies, conduction reliability is greater than 95% and decreases with increasing frequency due to an increase in AP interactions. Conduction reliability is less sensitive to fiber diameter and only decreases slightly with increasing fiber diameter. Finally, both the number and type of AP interactions significantly vary with both input frequencies and fiber diameter. Modeling the interactions between APs initiated by stimulus and APs initiated by underlying physiological activity in a nerve fiber opens opportunities towards understanding mechanisms of electrical stimulation therapies. 相似文献
83.
Sridevi Nagarajan Willem Rens James Stalker Tony Cox Malcolm A Ferguson-Smith 《BMC bioinformatics》2008,9(1):168
Background
Comparative genomics has become a significant research area in recent years, following the availability of a number of sequenced genomes. The comparison of genomes is of great importance in the analysis of functionally important genome regions. It can also be used to understand the phylogenetic relationships of species and the mechanisms leading to rearrangement of karyotypes during evolution. Many species have been studied at the cytogenetic level by cross species chromosome painting. With the large amount of such information, it has become vital to computerize the data and make them accessible worldwide. Chromhome is a comprehensive web application that is designed to provide cytogenetic comparisons among species and to fulfil this need. 相似文献84.
85.
V. Sridevi P. Giridhar P. S. Simmi G. A. Ravishankar 《Plant Cell, Tissue and Organ Culture》2010,101(3):339-347
Direct differentiation of shoot buds from the collar region of hypocotyl segments of Coffea canephora was obtained on Murashige and Skoog (MS) medium supplemented with 40 μM silver nitrate (AgNO3) and growth regulators indole-3-acetic acid (IAA) and N6 benzyladenine (BA). The highest response to shoot differentiation
of 60% frequency and the maximum number of multiple shoots (2–3) per explant were obtained on MS medium containing 8.87 μM
BA and 2.85 μM IAA. Apart from this, 70% of hypocotyl explants produced yellow friable embryogenic callus and also globular
primary somatic embryos. Subsequent transfer onto the same medium induced secondary somatic embryogenesis. The micro-shoots,
upon transfer to the same medium, in the following 6 weeks developed into 4-cm-long shoots with a single root. Further subculturing
onto the same medium induced 4–5 roots in a 4-week period. The resulting plantlets were hardened and transferred to micro-pots
containing sand:compost mixture (1:2), where 65% of them survived and resumed growth. By using optimal levels of AgNO3, it was possible to obtain effective direct organogenesis and embryogenesis. This system was used for genetic transformation
using Agrobacterium tumefaciens. A stable transformation frequency of 2–5% was obtained when both types of explants, i.e., hypocotyl explants with collar
region or hypocotyl explants without collar region, were co-cultivated with A. tumefaciens GV 3101 harboring pCAMBIA 1305.2 binary vector. This is the first report of a hypocotyl collar region-based Agrobacterium-mediated transformation protocol for the economically important tropical plant C. canephora. 相似文献
86.
Acid protease production by solid-state fermentation using Aspergillus oryzae MTCC 5341: optimization of process parameters 总被引:1,自引:0,他引:1
K. S. Vishwanatha A. G. Appu Rao Sridevi Annapurna Singh 《Journal of industrial microbiology & biotechnology》2010,37(2):129-138
Aspergillus oryzae MTCC 5341, when grown on wheat bran as substrate, produces several extracellular acid proteases. Production of the major
acid protease (constituting 34% of the total) by solid-state fermentation is optimized. Optimum operating conditions obtained
are determined as pH 5, temperature of incubation of 30°C, defatted soy flour addition of 4%, and fermentation time of 120 h,
resulting in acid protease production of 8.64 × 105 U/g bran. Response-surface methodology is used to generate a predictive model of the combined effects of independent variables
such as, pH, temperature, defatted soy flour addition, and fermentation time. The statistical design indicates that all four
independent variables have significant effects on acid protease production. Optimum factor levels are pH 5.4, incubation temperature
of 31°C, 4.4% defatted soy flour addition, and fermentation time of 123 h to yield a maximum activity of 8.93 × 105 U/g bran. Evaluation experiments, carried out to verify the predictions, reveal that A. oryzae produces 8.47 × 105 U/g bran, which corresponds to 94.8% of the predicted value. This is the highest acid protease activity reported so far,
wherein the fungus produces four times higher activity than previously reported [J Bacteriol 130(1): 48–56, 1977]. 相似文献
87.
Shin HM Minter LM Cho OH Gottipati S Fauq AH Golde TE Sonenshein GE Osborne BA 《The EMBO journal》2006,25(1):129-138
Notch1 specifically upregulates expression of the cytokine interferon-gamma in peripheral T cells through activation of NF-kappaB. However, how Notch mediates NF-kappaB activation remains unclear. Here, we examined the temporal relationship between Notch signaling and NF-kappaB induction during T-cell activation. NF-kappaB activation occurs within minutes of T-cell receptor (TCR) engagement and this activation is sustained for at least 48 h following TCR signaling. We used gamma-secretase inhibitor (GSI) to prevent the cleavage and subsequent activation of Notch family members. We demonstrate that GSI blocked the later, sustained NF-kappaB activation, but did not affect the initial activation of NF-kappaB. Using biochemical approaches, as well as confocal microscopy, we show that the intracellular domain of Notch1 (N1IC) directly interacts with NF-kappaB and competes with IkappaBalpha, leading to retention of NF-kappaB in the nucleus. Additionally, we show that N1IC can directly regulate IFN-gamma expression through complexes formed on the IFN-gamma promoter. Taken together, these data suggest that there are two 'waves' of NF-kappaB activation: an initial, Notch-independent phase, and a later, sustained activation of NF-kappaB, which is Notch dependent. 相似文献
88.
A functional role for the GCC185 golgin in mannose 6-phosphate receptor recycling 总被引:1,自引:0,他引:1 下载免费PDF全文
Reddy JV Burguete AS Sridevi K Ganley IG Nottingham RM Pfeffer SR 《Molecular biology of the cell》2006,17(10):4353-4363
Mannose 6-phosphate receptors (MPRs) deliver newly synthesized lysosomal enzymes to endosomes and then recycle to the Golgi. MPR recycling requires Rab9 GTPase; Rab9 recruits the cytosolic adaptor TIP47 and enhances its ability to bind to MPR cytoplasmic domains during transport vesicle formation. Rab9-bearing vesicles then fuse with the trans-Golgi network (TGN) in living cells, but nothing is known about how these vesicles identify and dock with their target. We show here that GCC185, a member of the Golgin family of putative tethering proteins, is a Rab9 effector that is required for MPR recycling from endosomes to the TGN in living cells, and in vitro. GCC185 does not rely on Rab9 for its TGN localization; depletion of GCC185 slightly alters the Golgi ribbon but does not interfere with Golgi function. Loss of GCC185 triggers enhanced degradation of mannose 6-phosphate receptors and enhanced secretion of hexosaminidase. These data assign a specific pathway to an interesting, TGN-localized protein and suggest that GCC185 may participate in the docking of late endosome-derived, Rab9-bearing transport vesicles at the TGN. 相似文献
89.
Hunsur Nagendra Nagesh Kalaga Mahalakshmi Naidu Damarla Harika Rao Jonnalagadda Padma Sridevi Dharmarajan Sriram Perumal Yogeeswari Kondapalli Venkata Gowri Chandra Sekhar 《Bioorganic & medicinal chemistry letters》2013,23(24):6805-6810
Focus in this Letter is made to design and synthesize a series of nineteen new 6-(4-((substituted-1H-1,2,3-triazol-4-yl)methyl)piperazin-1-yl)phenanthridine analogues employing click chemistry and evaluated for their anti-tubercular activity against Mycobacterium tuberculosis H37Rv. Among the tested compounds, 7f and 7j exhibited good activity (MIC = 3.125 μg/mL), while 8a displayed excellent activity (MIC = 1.56 μg/mL) against the growth of M. tuberculosis H37Rv. In addition, 7f, 7j and 8a compounds were subjected to cytotoxic studies against mouse macrophage (RAW264.7) cell lines and the selectivity index values are >15 indicating suitability of compounds for further drug development. 相似文献
90.
DNA damage activates nuclear Abl tyrosine kinase to stimulate intrinsic apoptosis in cancer cell lines and mouse embryonic stem cells. To examine the in vivo function of nuclear Abl in apoptosis, we generated Abl-μNLS (μ, mutated in nuclear localization signals) mice. We show here that cisplatin-induced apoptosis is defective in the renal proximal tubule cells (RPTC) from the Ablμ/μ mice. When injected with cisplatin, we found similar levels of platinum in the Abl+/+ and the Ablμ/μ kidneys, as well as similar initial inductions of p53 and PUMAα expression. However, the accumulation of p53 and PUMAα could not be sustained in the Ablμ/μ kidneys, leading to reductions in renal apoptosis and tubule damage. Co-treatment of cisplatin with the Abl kinase inhibitor, imatinib, reduced the accumulation of p53 and PUMAα in the Abl+/+ but not in the Ablμ/μ kidneys. The residual apoptosis in the Ablμ/μ mice was not further reduced in the Ablμ/μ; p53−/− double-mutant mice, suggesting that nuclear Abl and p53 are epistatic to each other in this apoptosis response. Although apoptosis and tubule damage were reduced, cisplatin-induced increases in phospho-Stat-1 and blood urea nitrogen were similar between the Abl+/+ and the Ablμ/μ kidneys, indicating that RPTC apoptosis is not the only factor in cisplatin-induced nephrotoxicity. These results provide in vivo evidence for the pro-apoptotic function of Abl, and show that its nuclear localization and tyrosine kinase activity are both required for the sustained expression of p53 and PUMAα in cisplatin-induced renal apoptosis. 相似文献