Abstract:
:Neural crest cell derivatives have been suggested to be involved in thymus development. We established nonlymphoid thymic stromal cell cultures capable of supporting T-cell differentiation. In these nonlymphoid cell cultures, we identified cells with phenotypic and biochemical markers specific for neuronal cells. Neurofilament mRNA and 68- and 160-kDa neurofilament proteins, as well as 74-kDa synapsin I isoform, were expressed in many of the cultured cells. For example, neurofilament immunoreactivity was detected in 20-30% of the cells. To see whether thymic neuronal-like cells were involved in a neural differentiation pathway, we investigated the effect of nerve growth factor (NGF) and interleukin 6 (IL-6), two known neurotrophic factors. The expression of the above-described neural markers was enhanced by NGF and IL-6, which we report to be produced in an autocrine way by thymic stromal cell cultures. Finally, we found that IL-6 gene expression in these cell cultures was enhanced by NGF. Evidence is thus offered of a neuromodulatory loop within the thymic stromal cell population supported by local production of NGF and IL-6 and involving neural cell elements. Interestingly, IL-6, which is known to be implicated in thymocyte differentiation, also displays a neuromodulatory activity on thymic stromal cells, suggesting a multivalent role for this cytokine within the thymus.
journal_name
Proc Natl Acad Sci U S Aauthors
Screpanti I,Meco D,Scarpa S,Morrone S,Frati L,Gulino A,Modesti Adoi
10.1073/pnas.89.8.3209keywords:
subject
Has Abstractpub_date
1992-04-15 00:00:00pages
3209-12issue
8eissn
0027-8424issn
1091-6490journal_volume
89pub_type
杂志文章abstract::Ion channel proteins control ionic flux across biological membranes through conformational changes in their transmembrane pores. An exponentially increasing number of channel structures captured in different conformational states are now being determined; however, these newly resolved structures are commonly classifie...
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.1902702116
更新日期:2019-07-09 00:00:00
abstract::Nanobacteria-like objects evidenced at the surface of the orthopyroxenes of the Tataouine meteorite in South Tunisia have been studied by scanning and transmission electron microscopies. A method of micromanipulation has been developed to ensure that exactly the same objects were studied by both methods. We have shown...
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.0832464100
更新日期:2003-06-24 00:00:00
abstract::Large quantities of mineral dust particles are frequently ejected into the atmosphere through the action of wind. The surface of dust particles acts as a sink for many gases, such as sulfur dioxide. It is well known that under most conditions, sulfur dioxide reacts on dust particle surfaces, leading to the production ...
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.1212297109
更新日期:2012-12-18 00:00:00
abstract::Plants frequently respond to herbivorous insect attack by synthesizing defense proteins that deter insect feeding and prevent additional herbivory. Maize (Zea mays L.) lines, resistant to feeding by a number of lepidopteran species, rapidly mobilize a unique 33-kDa cysteine protease in response to caterpillar feeding....
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.202224899
更新日期:2002-10-01 00:00:00
abstract::Agrobacterium tumefaciens is routinely used to engineer desirable genes into dicotyledonous plants. However, the economically important graminaceous plant maize is refractory to tumor induction by inoculation with virulent strains of A. tumefaciens. Currently, the only clearcut evidence for transferred DNA (T-DNA) tra...
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.90.4.1488
更新日期:1993-02-15 00:00:00
abstract::Transforming growth factor beta (TGF-beta) signals through a receptor complex containing the type I (TGF-beta RI) and type II (TGF-beta RII) receptors. We describe here biochemical studies on early events in the TGF-beta signaling pathways. TGF-beta RII is highly phosphorylated when expressed alone in COS-1 cells; its...
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.92.5.1565
更新日期:1995-02-28 00:00:00
abstract::The total synthesis of the sialic acid-containing antigenic epitope fucose GM(1) (Fuc-GM(1)) by an improved reactivity-based one-pot synthetic strategy is reported. Based on a thioglycoside reactivity database, three saccharide building blocks, 3, 4, and 5, were designed and prepared to incorporate a descending order ...
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.0337590100
更新日期:2003-02-04 00:00:00
abstract::Neuropilin-1 (NRP1) is a 130-kDa transmembrane receptor for semaphorins, mediators of neuronal guidance, and for vascular endothelial growth factor 165 (VEGF(165)), an angiogenesis factor. A 2.2-kb truncated NRP1 cDNA was cloned that encodes a 644-aa soluble NRP1 (sNRP1) isoform containing just the a/CUB and b/coagula...
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.040337597
更新日期:2000-03-14 00:00:00
abstract::Regulated changes in gene expression underlie many biological processes, but globally profiling cell-to-cell variations in transcriptional regulation is problematic when measuring single cells. Transcriptome-wide identification of regulatory heterogeneities can be robustly achieved by randomly collecting small numbers...
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.1311647111
更新日期:2014-02-04 00:00:00
abstract::Factor VII is a precursor to a serine protease that is present in mammalian plasma. In its activated form, it participates in blood coagulation by activating factor X and/or factor IX in the presence of tissue factor and calcium. Clones coding for factor VII were obtained from two cDNA libraries prepared from poly(A) ...
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.83.8.2412
更新日期:1986-04-01 00:00:00
abstract::The timing of neocortical regional specification was examined using a monoclonal antibody, designated PC3.1, that binds a 29-kDa polypeptide and recognizes a neuronal subpopulation located in the lateral but not dorsomedial neocortex in the rat. When lateral cortical tissue fragments at embryonic days 12 and 16 were 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.89.19.8879
更新日期:1992-10-01 00:00:00
abstract::The rates of reassociation of DNA from a monkey cell line (Vero), from SV40 pseudovirus (consisting of Vero DNA and virus protein coat), and from mature SV40 were measured. The results show that the host DNA in the pseudovirus contains repeated and unique sequences in the same proportions as normal host DNA; hence, no...
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.67.4.1886
更新日期:1970-12-01 00:00:00
abstract::To study the role of the interferon- (IFN) gammaR2 chain in IFN-gamma signaling and immune function, IFN-gammaR2-deficient mice have been generated and characterized. Cells derived from IFN-gammaR2 -/- mice are unable to activate either JAK/STAT signaling proteins or gene transcription in response to IFN-gamma. The la...
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.95.14.8233
更新日期:1998-07-07 00:00:00
abstract::Calcium-dependent protein kinases (CDPKs) comprise the major group of Ca2+-regulated kinases in plants and protists. It has long been assumed that CDPKs are activated, like other Ca2+-regulated kinases, by derepression of the kinase domain (KD). However, we found that removal of the autoinhibitory domain from Toxoplas...
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.1505914112
更新日期:2015-09-08 00:00:00
abstract::Approximately 25% of patients who are prescribed opioids for chronic pain misuse them, and 5 to 10% develop an opioid use disorder. Although the neurobiological target of opioids is well known, the molecular mechanisms that are responsible for the development of addiction-like behaviors in some but not all individuals...
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.1915143117
更新日期:2020-01-28 00:00:00
abstract::A mol of creatine kinase (EC 2.7.3.2), an enzyme with two identical subunits can be titrated very rapidly and stoichiometrically with 2 mol of 2-chloromercuri-4-nitrophenol, an environmentally sensitive chromophoric probe specific for thiols. Chemical modification does not inactivate the enzyme nor can the reaction be...
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.70.10.2858
更新日期:1973-10-01 00:00:00
abstract::Children who are treated for congenital cataracts later exhibit impairments in configural face analysis. This has been explained in terms of a critical period for the acquisition of normal face processing. Here, we consider a more parsimonious account according to which deficits in configural analysis result from the ...
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.1800901115
更新日期:2018-10-30 00:00:00
abstract::Optical imaging of the functional architecture of cortex, based on intrinsic signals, is a useful tool for the study of the development, organization, and function of the living mammalian brain. This relatively noninvasive technique is based on small activity-dependent changes of the optical properties of cortex. Thus...
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.88.24.11559
更新日期:1991-12-15 00:00:00
abstract::The catalytic generation of chiral ester enolate equivalents from α,β-unsaturated aldehydes with chiral N-hetereocyclic carbene catalysts makes possible highly enantioselective hetero-Diels-Alder reactions. The reactions proceed under simple, mild conditions with both aliphatic and aromatic substituted enals as substr...
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.1007469107
更新日期:2010-11-30 00:00:00
abstract::The highly ordered and reproducible structure of the fungal prion HET-s makes it an excellent model system for studying the inherent properties of prions, self-propagating infectious proteins that have been implicated in a number of fatal diseases. In particular, the HET-s prion-forming domain readily folds into a rel...
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.1322933111
更新日期:2014-04-08 00:00:00
abstract::The substrate specificity of thermophilic xylose isomerase from Clostridium thermosulfurogenes was examined by using predictions from the known crystal structure of the Arthrobacter enzyme and site-directed mutagenesis of the thermophile xylA gene. The orientation of glucose as a substrate in the active site of the th...
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.88.9.4015
更新日期:1991-05-01 00:00:00
abstract::The need to assess subtle, potentially exploitable changes in serial structure is paramount in the analysis of financial data. Herein, we demonstrate the utility of approximate entropy (ApEn), a model-independent measure of sequential irregularity, toward this goal, by several distinct applications. We consider both e...
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.0405168101
更新日期:2004-09-21 00:00:00
abstract::HLA-DR2 is associated with susceptibility to multiple sclerosis (MS). A peptide from human myelin basic protein (MBP, residues 85-99) was previously found to bind to purified HLA-DR2 (DRA, DRB1*1501) and to be recognized by human MBP-specific T cell clones. Soluble HLA-DR2 was expressed in the baculovirus system by re...
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.95.20.11828
更新日期:1998-09-29 00:00:00
abstract::Loss-of-function DJ-1 mutations can cause early-onset Parkinson's disease. The function of DJ-1 is unknown, but an acidic isoform accumulates after oxidative stress, leading to the suggestion that DJ-1 is protective under these conditions. We addressed whether this represents a posttranslational modification at cystei...
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.0402959101
更新日期:2004-06-15 00:00:00
abstract::To coordinate movements with events in a dynamic environment the brain has to anticipate when those events occur. A classic example is the estimation of time to contact (TTC), that is, when an object reaches a target. It is thought that TTC is estimated from kinematic variables. For example, a tennis player might use ...
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.1713316115
更新日期:2018-03-20 00:00:00
abstract::We have studied the properties of r-eag voltage-activated potassium channels in a stably transfected human embryonic kidney cell line. It was found that r-eag channels are rapidly and reversibly inhibited by a rise in intracellular calcium from 30 to 300 nM. The inhibition does not appear to depend on the activity 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.93.18.9910
更新日期:1996-09-03 00:00:00
abstract::The origin of plant chemical ecology generally dates to the late 1950s, when evolutionary entomologists recognized the essential role of plant secondary metabolites in plant-insect interactions and suggested that plant chemical diversity evolved under the selection pressure of herbivory. However, similar ideas had alr...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 传,历史文章,杂志文章
doi:10.1073/pnas.0709231105
更新日期:2008-03-25 00:00:00
abstract::Using a diverse collection of small molecules we recently found that compound sets from different sources (commercial; academic; natural) have different protein-binding behaviors, and these behaviors correlate with trends in stereochemical complexity for these compound sets. These results lend insight into structural ...
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.1015024108
更新日期:2011-04-26 00:00:00
abstract::The peptide chain release factor 2 (RF2) gene, prfB, was cloned from Salmonella typhimurium by DNA hybridization using the Escherichia coli prfB probe. The nucleotide and amino acid sequences of prfB are 87.0% and 95.6% homologous between E. coli and S. typhimurium, respectively, including an in-frame premature UGA st...
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.87.21.8432
更新日期:1990-11-01 00:00:00
abstract::The T-box transcription factor TBX5 plays essential roles in cardiac and limb development. Various mutations in the TBX5 gene have been identified in patients with Holt-Oram syndrome, which is characterized by congenital defects in the heart and upper extremities. In this study, we identified a WW-domain-containing tr...
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.0509109102
更新日期:2005-12-13 00:00:00