Abstract:
:We induced an essential fatty acid deficiency (EFAD) in human umbilical vein endothelial cells by culture in medium with 20% (vol/vol) delipidated fetal calf serum. EFAD, reflected by decreased cellular linoleic acid (18:2 omega 6) and arachidonic acid (20:4 omega 6) and emergence of the oleic acid derivative 5,8,11-eicosatrienoic acid (20:3 omega 9; Mead's acid), was evident after 1 week of culture and became pronounced after 2 weeks. Beyond that time point, control cells (cultured in 20% normal fetal calf serum) grew deficient of 18:2 omega 6, and EFAD cells died. 18:2 omega 6 addition to EFAD cells resulted in dose-dependent increases of 18:2 omega 6 and 20:4 omega 6. 20:4 omega 6 or 5,8,11,14,17-eicosapentaenoic acid (20:5 omega 3) additions resulted in normalization of these acids, and conversion of 20:5 omega 3 to 4,7,10,13,16,19-docosahexaenoic acid (22:6 omega 3) was noted. Agonist-induced increases in concentrations of prostacycline (prostaglandin I2; PGI2) and cytosolic Ca2+, [Ca2+]i, were reduced in EFAD cells and not restored by 18:2 omega 6 or 20:4 omega 6 additions. Change of the medium in EFAD cultures 1 day before the experiments decreased 20:3 omega 9 and normalized the PGI2 production and [Ca2+]i changes, whereas addition of 20:3 omega 9 to control cells impaired the [Ca2+]i response, indicating a suppressive effect of 20:3 omega 9. Thus, EFAD in endothelial cells is associated with abnormalities of eicosanoid and second-messenger production partly attributable to 20:3 omega 9 accumulation. Moreover, the gradual emergence of 18:2 omega 6 deficiency in regularly grown control cells underlines the need for careful analysis of fatty acids in long-term cell cultures.
journal_name
Proc Natl Acad Sci U S Aauthors
Lerner R,Lindström P,Berg A,Johansson E,Rosendahl K,Palmblad Jdoi
10.1073/pnas.92.4.1147subject
Has Abstractpub_date
1995-02-14 00:00:00pages
1147-51issue
4eissn
0027-8424issn
1091-6490journal_volume
92pub_type
杂志文章abstract::Two decades after the discovery of the first animal microRNA (miRNA), the number of miRNAs in animal genomes remains a vexing question. Here, we report findings from analyzing 1,323 short RNA sequencing samples (RNA-seq) from 13 different human tissue types. Using stringent thresholding criteria, we identified 3,707 s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1420955112
更新日期:2015-03-10 00:00:00
abstract::An oligoribonucleotide (a 27-mer) that mimics the sarcin/ricin (S/R) domain of Escherichia coli 23S rRNA binds elongation factor EF-G; the Kd is 6.9 microM, whereas for binding to ribosomes it is 0.7 microM. Binding saturates when EF-G and the S/R RNA are equimolar; at saturation 70% of the input RNA is in complexes w...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.23.12280
更新日期:1997-11-11 00:00:00
abstract::We report measurements of the geometrical structure and temporal evolution of metastable helical intermediates in the pathway for cholesterol crystallization in native and model biles. We find that the lecithin component in the bile can dramatically affect the kinetics along this pathway. We also present a theoretical...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.23.11341
更新日期:1993-12-01 00:00:00
abstract::Visual processing depends critically on the receptive field (RF) properties of visual neurons. However, comprehensive characterization of RFs beyond the primary visual cortex (V1) remains a challenge. Here we report fine RF structures in secondary visual cortex (V2) of awake macaque monkeys, identified through a proje...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1525505113
更新日期:2016-02-16 00:00:00
abstract::Sympatric speciation (SS), i.e., speciation within a freely breeding population or in contiguous populations, was first proposed by Darwin [Darwin C (1859) On the Origins of Species by Means of Natural Selection] and is still controversial despite theoretical support [Gavrilets S (2004) Fitness Landscapes and the Orig...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1514896112
更新日期:2015-09-22 00:00:00
abstract::Epithelial barrier disruption is a major cause of inflammatory bowel disease (IBD); however, the mechanism through which epigenetic regulation modulates intestinal epithelial integrity remains largely undefined. Here we show that EZH2, the catalytic subunit of polycomb repressive complex (PRC2), is indispensable for m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1700909114
更新日期:2017-05-09 00:00:00
abstract::Microtubules (MTs) are hollow cytoskeletal filaments assembled from αβ-tubulin heterodimers. Tau, an unstructured protein found in neuronal axons, binds to MTs and regulates their dynamics. Aberrant Tau behavior is associated with neurodegenerative dementias, including Alzheimer's. Here, we report on a direct force me...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1513172112
更新日期:2015-11-24 00:00:00
abstract::The origins of the five groups of living seed plants, including the single relictual species Ginkgo biloba, are poorly understood, in large part because of very imperfect knowledge of extinct seed plant diversity. Here we describe well-preserved material from the Early Cretaceous of Mongolia of the previously enigmati...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1621409114
更新日期:2017-03-21 00:00:00
abstract::The circadian clock in eukaryotes controls transcriptional and posttranscriptional events, including regulation of the levels and phosphorylation state of translation factors. However, the mechanisms underlying clock control of translation initiation, and the impact of this potential regulation on rhythmic protein syn...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1918459117
更新日期:2020-05-19 00:00:00
abstract::We examined the ability of macrophages and B cells to function as antigen-presenting cells (APCs) for murine TH1 and TH2 cloned T helper cell lines. Antigen presented by concanavalin A-elicited peritoneal macrophages or resting splenic B cells stimulated antigen-dependent proliferation of both T helper subsets. Parafo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.21.8181
更新日期:1988-11-01 00:00:00
abstract::Using direct percussion, language-competent bonobo-chimpanzees Kanzi and Pan-Banisha produced a significantly wider variety of flint tool types than hitherto reported, and used them task-specifically to break wooden logs or to dig underground for food retrieval. For log breaking, small flakes were rotated drill-like o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1212855109
更新日期:2012-09-04 00:00:00
abstract::Formulas are derived for the effect of size on a free-swimming microbe's ability to follow chemical, light, or temperature stimuli or to disperse in random directions. The four main assumptions are as follows: (i) the organisms can be modeled as spheres, (ii) the power available to the organism for swimming is proport...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.20.10949
更新日期:1997-09-30 00:00:00
abstract::Visualizing macromolecular complexes by single-particle electron microscopy (EM) entails stringent biochemical purification, specimen preparation, low-dose imaging, and 3D image reconstruction. Here, we introduce the "monolayer purification" method, which employs nickel-nitrilotriacetic acid (Ni-NTA) functionalized li...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0800867105
更新日期:2008-03-25 00:00:00
abstract::A culture of mouse A9 cells yielded clones of both high and low malignancy. Confirmation of the differences in malignancy of the clones was obtained after their hybridization with subclones of YACIR a lymphoma induced by Moloney leukemia virus. Low malignant A9 clones suppressed the malignancy of the YACIR partner in ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.73.6.2004
更新日期:1976-06-01 00:00:00
abstract::Energy-coupling factor (ECF) transporters are a recently discovered family of primary active transporters for micronutrients and vitamins, such as biotin, thiamine, and riboflavin. Found exclusively in archaea and bacteria, including the human pathogens Listeria, Streptococcus, and Staphylococcus, ECF transporters may...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1217361110
更新日期:2013-02-12 00:00:00
abstract::The neuronal nucleus plays a vital role in information processing, but whether it supports computational functions such as paired-pulse facilitation, comparable to synapses, is unclear. Ca(2+)-dependent movement of calmodulin (CaM) to the nucleus is highly responsive to Ca(2+) entry through L-type channels and promote...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.211563998
更新日期:2001-12-18 00:00:00
abstract::Intact squid axons were injected with aequorin and bathed in 3 mM Ca seawater (a concentration close to that of squid blood). Sodium and potassium currents were pharmacologically blocked and repetitive voltage-clamp pulses of a duration of 1.5 ms were applied (to simulate the duration of an action potential) at amplit...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.6.1847
更新日期:1985-03-01 00:00:00
abstract::Helicobacter pylori VacA, a pore-forming toxin secreted by an autotransporter pathway, causes multiple alterations in human cells, contributes to the pathogenesis of peptic ulcer disease and gastric cancer, and is a candidate antigen for inclusion in an H. pylori vaccine. Here, we present a 2.4-A crystal structure of ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0707447104
更新日期:2007-10-09 00:00:00
abstract::Cellular DNA and RNA were simultaneously quantitated in individual cells of cycling and quiescent populations by flow cytometry. Based on differences in RNA content, two distinct subcompartments, G1A and G1B, were recognized in the G1 phase of exponentially growing cells. After mitosis, cells reside in the low-RNA, G1...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.11.6696
更新日期:1980-11-01 00:00:00
abstract::We have isolated a protein from Saccharomyces cerevisiae that binds specifically to a nucleotide sequence associated with the autonomously replicating sequence (ARS) ARS120, located in the telomeric region of a yeast chromosome. "Footprinting" analysis revealed that a 26-base-pair DNA sequence, 5'-CAAGTGCCGTGCATAATGAT...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.3.743
更新日期:1988-02-01 00:00:00
abstract::Preincubation of quiescent BALB/C3T3 cells with uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) in conditioned medium resulted in a time- and concentration-dependent stimulation of uptake of 2-deoxyglucose, uridine, and alpha-aminoisobutyric acid over that seen in conditioned medium alone. The apparent Km values ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.8.3859
更新日期:1978-08-01 00:00:00
abstract::The amino acid sequences of a number of closely related proteins ("napin") isolated from Brassica napus were determined by mass spectrometry without prior separation into individual components. Some of these proteins correspond to those previously deduced (napA, BngNAP1, and gNa), chiefly from DNA sequences. Others we...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.8.3647
更新日期:1996-04-16 00:00:00
abstract::Transcriptionally silent genes are maintained in inaccessible chromatin. Accessibility of these genes requires their modification by chromatin remodeling complexes (CRCs), which are recruited to promoters by sequence-specific DNA-binding proteins. Early B-cell factor (EBF), which is crucial for B-cell lineage specific...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0809485106
更新日期:2009-07-07 00:00:00
abstract::Mammalian ferritin from horse spleen undergoes an electrochemical or chemical reduction reaction in which each iron atom present is reduced by one electron (2300 electrons per ferritin molecule containing 2300 Fe3+ ions). Midpoint potentials of -190 mV, -310 mV, and -416 mV were determined at pH 7.0, 8.0, and 9.0. Thi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.11.3640
更新日期:1985-06-01 00:00:00
abstract::Selective blockade of gene expression by designed small molecules is a fundamental challenge at the interface of chemistry, biology, and medicine. Transcription factors have been among the most elusive targets in genetics and drug discovery, but the fields of chemical biology and genetics have evolved to a point where...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1312473110
更新日期:2013-09-24 00:00:00
abstract::Mutations of esterase 3 confer two forms of organophosphate resistance on contemporary Australasian Lucilia cuprina. One form, called diazinon resistance, is slightly more effective against commonly used insecticides and is now more prevalent than the other form, called malathion resistance. We report here that the si...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0509590103
更新日期:2006-06-06 00:00:00
abstract::To identify mannosyl (Man)-containing intermediates of the human glycoinositol phospholipid (GPI) anchor pathway and examine their expression in paroxysmal nocturnal hemoglobinuria (PNH), mannolipid products deriving from in vitro guanosine diphosphate [3H]Man labeling of HeLa cell microsomes were characterized. The d...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.13.6025
更新日期:1992-07-01 00:00:00
abstract::The interaction between mutations in the tumor-suppressor genes Apc and p53 was studied in congenic mouse strains to minimize the influence of polymorphic modifiers. The multiplicity and invasiveness of intestinal adenomas of Apc(Min/+) (Min) mice was enhanced by deficiency for p53. In addition, the occurrence of desm...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.050585597
更新日期:2000-03-28 00:00:00
abstract::A mathematical method is developed which enables us to treat exactly the process of coincidental evolution under mutation, unequal intrachromosomal crossing-over as well as ordinary crossing-over between homologous chromosomes in a finite population of the effective size N. It makes use of finite difference equations ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.8.4001
更新日期:1979-08-01 00:00:00
abstract::Sulfur assimilation is an evolutionarily conserved pathway that plays an essential role in cellular and metabolic processes, including sulfation, amino acid biosynthesis, and organismal development. We report that loss of a key enzymatic component of the pathway, bisphosphate 3'-nucleotidase (Bpnt1), in mice, both who...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1715302115
更新日期:2018-03-20 00:00:00