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991.
High‐Resolution Molecular Validation of Self‐Renewal and Spontaneous Differentiation in Clinical‐Grade Adipose‐Tissue Derived Human Mesenchymal Stem Cells 下载免费PDF全文
Amel Dudakovic Emily Camilleri Scott M. Riester Eric A. Lewallen Sergiy Kvasha Xiaoyue Chen Darcie J. Radel Jarett M. Anderson Asha A. Nair Jared M. Evans Aaron J. Krych Jay Smith David R. Deyle Janet L. Stein Gary S. Stein Hee‐Jeong Im Simon M. Cool Jennifer J. Westendorf Sanjeev Kakar Allan B. Dietz Andre J. van Wijnen 《Journal of cellular biochemistry》2014,115(10):1816-1828
992.
993.
Plant allocation patterns may affect soil C and N storage due to differences in litter quality and the depth of plant C and
N inputs into the soil. We studied the dynamics of dual-labeled (13C/15N) Pinus ponderosa needles and fine roots placed at two soil depths (O and A horizon) in a temperate conifer forest soil during 2 y. Input of
C as fine roots resulted in much more C retained in soil (70.5 ± 2.2% of applied) compared with needle C (42.9 ± 1.3% of applied)
after 1.5 y. Needles showed faster mass loss, rates of soil 13CO2 efflux, and more 15N immobilized into microbial biomass than did fine roots. The larger proportion of labile C compounds initially present in
needles (17% more needle C was water soluble than in fine roots) likely contributed to its shorter C residence time and greater
degree of transformation in the soil. A double exponential decay function best described the rate of 13C loss, with a smaller initial pulse of C loss from fine roots (S1k1) and a slower decay rate of the recalcitrant C pool for fine roots (0.03 y−1) compared with (0.19 y−1) for needles. Soil 13C respiration, representing heterotrophic respiration of litter C, was much more seasonal from the O horizon than from the
A. However, offsetting seasonal patterns in 13C dynamics in the O horizon resulted in no net effect of soil depth on total 13C retention in the soil after 1.5 y for either litter. Almost 90% of applied litter N was retained in the soil after 1.5 y,
independent of litter quality or soil depth. Very small amounts of 13C or 15N (<3% of applied) moved to the horizon above or below the placement depth (i.e., O to A or A to O). Our results suggest that
plant allocation belowground to fine roots results in more C retained and less N mineralized compared with allocation aboveground
to needles, primarily due to litter quality differences. 相似文献
994.
Lee EG Yoon SH Das A Lee SH Li C Kim JY Choi MS Oh DK Kim SW 《Biotechnology and bioengineering》2009,102(1):200-208
The amplification of gltA gene encoding citrate synthase of TCA cycle was required for the efficient conversion of acetyl-CoA, generated during vanillin production from ferulic acid, to CoA, which is essential for vanillin production. Vanillin of 1.98 g/L was produced from the E. coli DH5alpha (pTAHEF-gltA) with gltA amplification in 48 h of culture at 3.0 g/L of ferulic acid, which was about twofold higher than the vanillin production of 0.91 g/L obtained by the E. coli DH5alpha (pTAHEF) without gltA amplification. The icdA gene encoding isocitrate dehydrogenase of TCA cycle was deleted to make the vanillin producing E. coli utilize glyoxylate bypass which enables more efficient conversion of acetyl-CoA to CoA in comparison with TCA cycle. The production of vanillin by the icdA null mutant of E. coli BW25113 harboring pTAHEF was enhanced by 2.6 times. The gltA amplification of the glyoxylate bypass in the icdA null mutant remarkably increased the production rate of vanillin with a little increase in the amount of vanillin production. The real synergistic effect of gltA amplification and icdA deletion was observed with use of XAD-2 resin reducing the toxicity of vanillin produced during culture. Vanillin of 5.14 g/L was produced in 24 h of the culture with molar conversion yield of 86.6%, which is the highest so far in vanillin production from ferulic acid using recombinant E. coli. 相似文献
995.
Nishiya T Matsumoto K Maekawa S Kajita E Horinouchi T Fujimuro M Ogasawara K Uehara T Miwa S 《The Journal of biological chemistry》2011,286(11):9009-9019
Inducible nitric-oxide synthase (iNOS, NOS2) plays a prominent role in macrophage bactericidal and tumoricidal activities. A relatively large amount of NO produced via iNOS, however, also targets the macrophage itself for apoptotic cell death. To uncover the intrinsic mechanisms of iNOS regulation, we have characterized the SPRY domain- and SOCS box-containing protein 1 (SPSB1), SPSB2, and SPSB4 that interact with the N-terminal region of iNOS in a D-I-N-N-N sequence-dependent manner. Fluorescence microscopy revealed that these SPSB proteins can induce the subcellular redistribution of iNOS from dense regions to diffused expression in a SOCS box-dependent manner. In immunoprecipitation studies, both Elongin C and Cullin-5, components of the multi-subunit E3 ubiquitin ligase, were found to bind to iNOS via SPSB1, SPSB2, or SPSB4. Consistently, iNOS was polyubiquitinated and degraded in a proteasome-dependent manner when SPSB1, SPSB2, or SPSB4 was expressed. SPSB1 and SPSB4 had a greater effect on iNOS regulation than SPSB2. The iNOS N-terminal fragment (residues 1-124 of human iNOS) could disrupt iNOS-SPSB interactions and inhibit iNOS degradation. In lipopolysaccharide-treated macrophages, this fragment attenuated iNOS ubiquitination and substantially prolonged iNOS lifetime, resulting in a corresponding increase in NO production and enhanced NO-dependent cell death. These results not only demonstrate the mechanism of SPSB-mediated iNOS degradation and the relative contributions of different SPSB proteins to iNOS regulation, but also show that iNOS levels are sophisticatedly regulated by SPSB proteins in activated macrophages to prevent overproduction of NO that could trigger detrimental effects, such as cytotoxicity. 相似文献
996.
997.
Wei-Wei Pan Jian-Jie Zhou Chao Yu Ying Xu Lian-Jun Guo Hai-Yi Zhang Dawang Zhou Fang-Zhou Song Heng-Yu Fan 《The Journal of biological chemistry》2013,288(41):29680-29691
Cullin-RING ubiquitin ligases (CRLs) are the largest family of E3 ligases and require cullin neddylation for their activation. The NEDD8-activating enzyme inhibitor MLN4924 reportedly blocked cullin neddylation and inactivated CRLs, which resulted in apoptosis induction and tumor suppression. However, CRL roles in ovarian cancer cell survival and the ovarian tumor repressing effects of MLN4924 are unknown. We show here that CRL4 components are highly expressed in human epithelial ovarian cancer tissues. MLN4924-induced DNA damage, cell cycle arrest, and apoptosis in ovarian cancer cells in a time- and dose-dependent manner. In addition, MLN4924 sensitized ovarian cancer cells to other chemotherapeutic drug treatments. Depletion of CRL4 components Roc1/2, Cul4a, and DDB1 had inhibitory effects on ovarian cancer cells similar to MLN4924 treatment, which suggested that CRL4 inhibition contributed to the chemotherapeutic effect of MLN4924 in ovarian cancers. We also investigated for key CRL4 substrate adaptors required for ovarian cancer cells. Depleting Vprbp/Dcaf1 did not significantly affect ovarian cancer cell growth, even though it was expressed by ovarian cancer tissues. However, depleting Cdt2/Dcaf2 mimicked the pharmacological effects of MLN4924 and caused the accumulation of its substrate, CDT1, both in vitro and in vivo. MLN4924-induced DNA damage and apoptosis were partially rescued by Cdt1 depletion, suggesting that CRL4CDT2 repression and CDT1 accumulation were key biochemical events contributing to the genotoxic effects of MLN4924 in ovarian cancer cells. Taken together, these results indicate that CRL4CDT2 is a potential drug target in ovarian cancers and that MLN4924 may be an effective anticancer agent for targeted ovarian cancer therapy. 相似文献
998.
M. R. Naidu P. Singh B. S. Dahiya 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,75(3):514-517
Summary Selection in the F3 generation for seed yield, fruiting branches/plant, effective pods/plant, and seed index (100-seed weight) was carried out in two chickpea crosses. Sixty F5 lines (15 lines/selection criterion) along with check variety were evaluated for seed yield in three distinct environments. The effects of selection criteria on yield stability was examined using linear regression approach and genotype-grouping technique. There were no differences between selection criteria for linear yield responses of F5 lines to different environments. Within all four selection criteria the lines showed similar linear responses. The non-linear component was relatively higher for lines selected for effective pods and seed index than lines selected for yield and fruiting branches. On the basis of mean yield and coefficient of variation across environments, the seed index was the least effective selection criterion for developing high yielding and stable lines. When the results of stability parameters and genotype-grouping technique were considered together, selection for yield and fruiting branches was highly effective for isolating stable and high yielding lines. 相似文献
999.
Antonietta Bernardo Mario Patrizio Giulio Levi Tamara C. Petrucci 《Cellular and molecular neurobiology》1994,14(2):159-173
Summary 1. We have previously shown that acute exposure to the HIV coat protein gp120 interferes with the -adrenergic regulation of astroglial and microglial cells (Leviet al., 1993). In particular, exposure to 100 pM gp120 for 30 min depressed the phosphorylation of vimentin and glial fibrillary acidic protein (GFAP) induced by isoproterenol in rat cortical astrocyte cultures. In the present study we have extended our analysis on the effects of gp120 on astroglial protein phosphorylation.2. We found that chronic (3-day) treatment of the cells with 100 pM gp120 before exposure to isoproterenol was substantially more effective than acute treatment in depressing the stimulatory effect of the -adrenergic agonist on vimentin and GFAP phosphorylation.3. Even after chronic treatment with gp120, no differences were found in the levels and solubility of these proteins.4. Besides stimulating the phosphorylation of intermediate filament proteins, isoproterenol inhibited the incorporation of32P into a soluble acidic protein of 80,000M
r
, which was only minimally present in Triton X-100-insoluble extracts.5. Treatment of astrocytes with a phorbol ester or exposure to3H-myristic acid indicated that the acidic 80,000M
r
protein is a substrate for protein kinase C (PKC) and is myristoylated, thus suggesting that it is related to the MARCKS family of PKC substrates.6. Acute (30-min) treatment with 100 pM gp120 totally prevented the inhibitory effect of isoproterenol on the phorphorylation of the 80,000M
r
MARCKS-like protein.7. Our studies corroborate the hypothesis that viral components may contribute to the neuropathological changes observed in AIDS through the alteration of signal transduction systems in glial cells. 相似文献
1000.
Vitamins C and E Modulate Neuronal Potassium Currents 总被引:1,自引:0,他引:1
We investigated the effects of vitamins C and E on the delayed-rectifier potassium current (IKDR), which is important in repolarizing the membrane potential, and on the transient A-type potassium current (IKA), which regulates neuronal firing frequency. The whole-cell patch-clamp technique was used to measure the currents from cultured
Drosophila neurons derived from embryonic neuroblasts. The membrane potential was stepped to different voltages between −40 and +60
mV from a holding potential of −80 mV. IKDR and IKA measured in the vitamin C-containing solution (IKDR 305 ± 16 pA, IKA 11 ± 2 pA) were smaller than those measured in the control solution (488 ± 21 pA, IKA 28 ± 3 pA). By contrast, IKDR and IKA measured in the vitamin E-containing solution (IKDR 561 ± 21 pA, IKA 31 ± 3 pA) were greater than those measured in the control solution (422 ± 15 pA, 17 ± 2 pA). These results indicate that
vitamins C and E can modulate potassium current amplitudes and possibly lead to altered neuronal excitability. 相似文献