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Publication
Journal: Journal of Molecular Biology
September/13/2004
Abstract
Sso10a is a member of a group of DNA-binding proteins thought to be important in chromatin structure and regulation in the hyperthermophilic archaeon Sulfolobus solfataricus. We have determined the structure of Sso10a to 1.47A resolution directly with unlabelled native crystals by a novel approach using sulfur single-wavelength anomalous scattering (SAS) from a chromium X-ray source. The 95 amino acid residue protein contains a winged helix DNA-binding domain with an extended C-terminal alpha-helix that leads to dimerization by forming a two-stranded, antiparallel coiled-coil rod. The winged helix domains are at opposite ends of the extended coiled coil with two putative DNA-recognition helices separated by 55A and rotated by 83 degrees. Formation of stable dimers in solution is demonstrated by both analytical ultracentrifugation and differential scanning calorimetry. With a T0 of 109 degrees C, Sso10a is one of the most stable two-stranded coiled coils known. The coiled coil contains a rare aspartate residue (D69) in the normally hydrophobic d position of the heptad repeat, with two aspartate-lysine (d-g') interhelical ion pairs in the symmetrical dimer. Mutation of D69 to alanine resulted in an increase in thermal stability, indicating that destabilization resulting from the partially buried aspartate residue cannot be offset by ion pair formation. Possible DNA-binding interactions are discussed on the basis of comparisons to other winged helix proteins. The structure of Sso10a provides insight into the structures of the conserved domain represented by COG3432, a group of more than 20 hypothetical transcriptional regulators coded in the genomic sequences of both crenarchaeota and euryarchaeota.
Publication
Journal: Aging
February/23/2017
Abstract
Isoketals (IsoKs) are highly reactive γ-ketoaldehyde products of lipid peroxidation that covalently adduct lysine side chains in proteins, impairing their function. Using C. elegans as a model organism, we sought to test the hypothesis that IsoKs contribute to molecular aging through adduction and inactivation of specific protein targets, and that this process can be abrogated using salicylamine (SA), a selective IsoK scavenger. Treatment with SA extends adult nematode longevity by nearly 56% and prevents multiple deleterious age-related biochemical and functional changes. Testing of a variety of molecular targets for SA's action revealed the sirtuin SIR-2.1 as the leading candidate. When SA was administered to a SIR-2.1 knockout strain, the effects on lifespan and healthspan extension were abolished. The SIR-2.1-dependent effects of SA were not mediated by large changes in gene expression programs or by significant changes in mitochondrial function. However, expression array analysis did show SA-dependent regulation of the transcription factor ets-7 and associated genes. In ets-7 knockout worms, SA's longevity effects were abolished, similar to sir-2.1 knockouts. However, SA dose-dependently increases ets-7 mRNA levels in non-functional SIR-2.1 mutant, suggesting that both are necessary for SA's complete lifespan and healthspan extension.
Publication
Journal: Proteins: Structure, Function and Genetics
August/15/2001
Abstract
We have used NMR methods to characterize the structure and dynamics of ribonuclease Sa in solution. The solution structure of RNase Sa was obtained using the distance constraints provided by 2,276 NOEs and the C6-C96 disulfide bond. The 40 resulting structures are well determined; their mean pairwise RMSD is 0.76 A (backbone) and 1.26 A (heavy atoms). The solution structures are similar to previously determined crystal structures, especially in the secondary structure, but exhibit new features: the loop composed of Pro 45 to Ser 48 adopts distinct conformations and the rings of tyrosines 51, 52, and 55 have reduced flipping rates. Amide protons with greatly reduced exchange rates are found predominantly in interior beta-strands and the alpha-helix, but also in the external 3/10 helix and edge beta-strand linked by the disulfide bond. Analysis of (15)N relaxation experiments (R1, R2, and NOE) at 600 MHz revealed five segments, consisting of residues 1-5, 28-31, 46-50, 60-65, 74-77, retaining flexibility in solution. The change in conformation entropy for RNase SA folding is smaller than previously believed, since the native protein is more flexible in solution than in a crystal.
Publication
Journal: Oncodevelopmental biology and medicine : the journal of the International Society for Oncodevelopmental Biology and Medicine
October/11/1982
Abstract
The intracellular presence of alpha-fetoprotein (AFP) and serum albumin (SA) has been recently demonstrated in the developing brain of primates, rats and mice. We report here the morphologic localization by immunocytochemical methods of AFP, SA, ovalbumin (OA) and immunoglobulin G (IgG) in the nervous system of chicken embryos. AFP was detected inside cells of the neural crest as soon as 48 hours after fertilization. Subsequently, the protein could be localized in many other neural structures, including cerebral cortex, brain stem nuclei, sensory retina, spinal cord and dorsal root ganglia. Disappearance of AFP inside the nervous system was observed 15 to 17 days after fertilization. The localization pattern of SA was similar to that of AFP, with the only difference being a short (2 to 3 days) displacement in time. On the contrary, OA and IgG were not found in the developing nervous system throughout the period examined. This provides support to the selectivity of the neural internalization of AFP and SA, and seems to exclude a mechanism of passive diffusion to explain such incorporation.
Authors
Publication
Journal: Zhongguo yao li xue bao = Acta pharmacologica Sinica
June/24/1999
Abstract
OBJECTIVE
To study the actions of salvianolic acid A (SA-A) on liver injury and liver fibrosis.
METHODS
The liver fibrotic rat was made by i.p. injection of CCl4. The model rats were divided into 3 groups treated with SA-A, colchicine (Col), and Salvia miltiorrhiza Bunge (SMB), respectively. Six wk later the rat liver pathology was examined, type I and III collagen in the liver were examined by immunohistochemistical method. Also hydroxyproline (Hyd) and malondialdehyde (MDA) in the liver, alanine aminotransferase (AlaAT), aspartate aminotransferase (AspAT), and albumin (Alb) levels in the serum were measured.
RESULTS
SA-A inhibited serum AlaAT and AspAT activities, decreased MDA and Hyd contents, alleviated liver fibrogenesis, protected deposition of type I and III collagen in liver matrix. The actions of SA-A on liver fibrosis were similar to those of Col and SMB, action of SA-A decreasing MDA was better than that of Col.
CONCLUSIONS
SA-A has marked effects against liver injury and fibrosis, associated with its anti-lipid peroxidation actions.
Publication
Journal: Shock
September/30/2009
Abstract
Endotoxemia caused by LPS is a life-threatening and inflammatory condition contributing to multiple organ failure. Viruses or bacteria require sialic acid (SA) for target-cell binding. We suggest that exogenous SA through masking or mediating the binding of LPS to the target cells may attenuate LPS-induced liver dysfunction and cecal ligation and puncture-induced shock. We found that SA can directly scavenge O2-, H2O2, and NO activity by a chemiluminescence analyzer and bind to LPS with high affinity using surface plasmon resonance. Intravenous SA significantly increased plasma SA concentration within 4 h. We then assessed the potential effect of SA on LPS-induced acute endotoxemia in the rat. Intravenous LPS (10-50 mg/kg) dose-dependently increased plasma endotoxin and reactive oxygen species in the blood, bile, and liver and increased plasma alanine aminotransferase and aspartate aminotransferase levels as well as TNF-alpha, monocyte chemoattractant protein 1, tissue inhibitor of metalloproteinase 1, IL-1beta, and IL-6 levels in the rats. Thirty minutes after LPS stimulation, SA decreased LPS-enhanced endotoxin level, oxidative stress, alanine aminotransferase and aspartate aminotransferase levels, and cytokine concentration and ameliorated histopathologic alteration in the liver. We found that SA increased LPS-depressed Mn-superoxide dismutase, CuZn-superoxide dismutase, and heat shock protein 70 and decreased LPS-enhanced iNOS and proapoptotic Bax protein expression in the liver by Western blot. Sialic acid was given after treatment to rats subjected to cecal ligation and puncture, and the hypotensive effect was blunted for 6 h. In conclusion, SA treatment can counteract LPS-enhanced acute endotoxemia and oxidative injury via a direct scavenging reactive oxygen species activity and neutralization potential.
Publication
Journal: European Journal of Clinical Pharmacology
March/1/1984
Abstract
The kinetics of disposition of total and free salicylic acid (SA) in blood plasma was evaluated after single and multiple oral administration of acetylsalicylic acid (ASA) to healthy female and male volunteers. In both single and multiple dose studies significant sex differences were found in the plasma levels of SA, which were due, at least in part, to individual, sex-determined differences in the rate of absorption and elimination of SA; a slower absorption rate in men reduced the magnitude of the peak plasma levels of SA. The corresponding area under concentration-time curves were always significantly lower. The elimination rate of SA in men was increased in comparison with women. The higher plasma clearance in men resulted from the kinetics of absorption and elimination. The sex differences appear to be clinical significance, since men achieved lower plasma levels of SA than women after the same weight-adjusted dose of ASA.
Publication
Journal: Biomacromolecules
December/26/2007
Abstract
Cationic polymers have been receiving growing attention as gene delivery carriers. Herein, a series of novel cationic supramolecular polyrotaxanes with multiple cationic alpha-cyclodextrin (alpha-CD) rings threaded and blocked on a poly[(ethylene oxide)-ran-(propylene oxide)] (P(EO-r-PO)) random copolymer chain were synthesized and investigated for gene delivery. In the cationic polyrotaxanes, approximately 12 cationic alpha-CD rings were threaded on the P(EO-r-PO) copolymer with a molecular weight of 2370 Da and an EO/PO molar ratio of 4:1, while the cationic alpha-CD rings were grafted with linear or branched oligoethylenimine (OEI) of various chain lengths and molecular weights up to 600 Da. The OEI-grafted alpha-CD rings were only located selectively on EO segments of the P(EO-r-PO) chain, while PO segments were free of complexation. This increased the mobility of the cationic alpha-CD rings and the flexibility of the polyrotaxanes, which enhanced the interaction of the cationic alpha-CD rings with DNA and/or the cellular membrane. All cationic polyrotaxanes synthesized in this work could efficiently condense plasmid DNA to form nanoparticles that were suitable for delivery of the gene. Cytotoxicity studies showed that the cationic polyrotaxanes with all linear OEI chains of molecular weights up to 423 Da exhibited much less cytotoxicity than high-molecular-weight branched polyethylenimine (PEI) (25 kDa) in both HEK293 and COS7 cell lines. The cationic polyrotaxanes displayed high gene transfection efficiencies in a variety of cell lines including HEK293, COS7, BHK-21, SKOV-3, and MES-SA. Particularly, the gene delivery capability of the cationic polyrotaxanes in HEK293 cells was much higher than that of high-molecular-weight branched PEI (25 k).
Publication
Journal: Analytical Chemistry
June/5/2007
Abstract
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was developed for spatial profiling of phytochemicals and secondary metabolites in integrated herbal tissue without solvent extraction. Abundant alkaloid ions, including (+)-menisperine (m/z 356), magnoflorine (m/z 342), stepharanine (m/z 324), protonated sinomenine (m/z 330), protonated sinomendine (m/z 338), and a metabolite at m/z 314, could be directly desorbed from alpha-cyano-4-hydroxycinnamic acid- (CHCA-) coated stem tissue of Sinomenium acutum upon N2 laser (337 nm) ablation, while the ion signals desorbed from sinapinic acid- (SA-) coated and 2,5-dihydroxybenzoic acid- (DHB-) coated stem tissue were at least 10 times weaker. Solvent composition in the matrix solution could have significant effects on the ion intensity of the metabolites. Under optimized conditions that maximize the ion intensity and form homogeneous matrix crystals on the tissue surface, spatial distributions of the metabolites localized in different tissue regions, including cortex, phloem, xylem, rim, and pith, and their relative abundances could be semiquantitatively determined. The three metabolites detected at m/z 356, 342, and 314 showed specific distributions in the herbal samples collected from different growing areas, while others were not. By applying principal component analysis (PCA), the characteristic metabolites in specific tissue regions could be easily determined, allowing unambiguous differentiation of the herbal samples from different geographic locations.
Publication
Journal: Experimental Hematology
June/20/2001
Abstract
OBJECTIVE
The hematopoietic microenvironment is complex, and the role of myofibroblast in its function is crucial. In order to obtain a stable model reflecting this particular cell type, we have previously established human bone marrow cell lines from primary myofibroblastic Stro1(+) population (pStro1(+)). We placed HPV16 E6 and E7 expression under the control of different promoters. Here, we have characterized and studied the hematopoietic support for two cell lines corresponding to the promoters alpha-SM (alphaSM-56 line) and SV40 (SV40-56 line).
METHODS
The expression profile was analyzed at the RNA level by gene array and at the protein level by Western blot, flow cytometry, and ELISA. Hematopoietic support determined using colony-forming unit (CFU) and stroma-adherent colony-forming cell (SA-CFC) assays.
RESULTS
The phenotype of cell lines was not significantly modified compared with primary myofibroblastic cells. They secreted a broad spectrum of hematopoietic cytokines and nonspecific mediators. The two lines allowed the growth of hematopoietic precursors and had different support capabilities.
CONCLUSIONS
We have extensively characterized two novel human bone marrow stromal cell lines. They retained a myofibroblastic phenotype and have substantial but different hematopoietic support capabilities. These lines provided a basis for determining stromal factors involved in stem-cell regulation.
Publication
Journal: Aging
February/23/2017
Abstract
The corneal epithelium plays important roles in the maintenance of corneal transparency for good vision, and acts as a protective barrier against foreign insults. Structural and functional changes with aging in the corneal epithelium have been documented. Here we found that transforming growth factor-β (TGF-β) is highly expressed in the elderly donor corneal epithelium, as are senescence-associated genes, such as p16 and p21. In human corneal epithelial cell (HCEC) models, TGF-β induces cellular senescence, characterized by increased SA-β-gal positive cells and elevated expression of p16 and p21. Pharmacological inhibition of TGF-β signaling alleviates TGF-β-induced cellular senescence. In addition, we determined that senescence-associated inflammation was significantly aggravated in TGF-β-induced cellular senescence by detecting the expression of interleukin-6 (IL-6), IL-8, and tumor necrosis factor alpha (TNFα). Both genetic and pharmacological approaches revealed that blocking nuclear factor-κB (NF-κB) signaling not only inhibited the production of inflammatory factors, but also rescued the senescent phenotype induced by TGF-β in HCECs. Mechanistically, TGF-β induced an atypical RNA stress responses, leading to accelerated mRNA degradation of IκBα, an inhibitor of NF-κB. Together, our data indicate that TGF-β-driven NF-κB activation contributes to corneal epithelial senescence via RNA metabolism and the inflammation blockade can attenuate TGF-β-induced senescence.
Publication
Journal: Journal of Reproduction and Development
October/18/2007
Abstract
Sanguinarine (SA), a phytobiotic from Sanguinaria Canadensis, has been demonstrated to inhibit vessel growth. Current restrictions on the use of antibiotic growth promoters have motivated addition of this alkaloid as a naturally appetizing feed additive for farm animals. However, concern may araise since angiogenesis is a fundamental event in ovarian follicle growth. Therefore, the aim of this study was to evaluate the potential negative role of SA in follicular angiogenesis. For this purpose, we studied the effect of 300 nM SA on the production of vascular endothelial growth factor (VEGF) by swine granulosa cells from follicles >5 mm and on the activation of Akt, the main effector of the VEGF signalling pathway. In addition, the potential interference of SA in vessel development was tested in an in vitro angiogenesis bioassay. SA inhibited both VEGF production and VEGF-induced Akt activation in swine granulosa cells. Moreover, it was able to block vessel growth induced by VEGF. Taken together, our results suggest that SA could be detrimental to follicular angiogenesis, and therefore supplementation of feed with this alkaloid should be carefully considered.
Publication
Journal: PLoS ONE
January/29/2020
Abstract
<Abstr<em>a</em>ctText>The psychologic<em>a</em>l he<em>a</em>lth (PH) of doctors <em>a</em>ffects the qu<em>a</em>lity of medic<em>a</em>l service <em>a</em>nd is rel<em>a</em>ted to the s<em>a</em>fety of p<em>a</em>tients. The serious problems with the doctor-p<em>a</em>tient rel<em>a</em>tionship in Chin<em>a</em> c<em>a</em>n le<em>a</em>d to long-term imb<em>a</em>l<em>a</em>nces in doctor PH, <em>a</em>nd the poor PH st<em>a</em>tus of doctors h<em>a</em>s r<em>a</em>ised schol<em>a</em>rs' concern. Current rese<em>a</em>rch m<em>a</em>inly focuses on how f<em>a</em>ctors such <em>a</em>s soci<em>a</em>l support <em>a</em>nd the imp<em>a</em>ct of the residenti<em>a</em>l environment correl<em>a</em>te with individu<em>a</em>l PH. We continue this direction of rese<em>a</em>rch to see how the mech<em>a</em>nism of soci<em>a</em>l support imp<em>a</em>cts physici<em>a</em>n PH, <em>a</em>lso investig<em>a</em>ting the moder<em>a</em>ting effect of demogr<em>a</em>phic indic<em>a</em>tors on physici<em>a</em>n PH.</Abstr<em>a</em>ctText><Abstr<em>a</em>ctText>B<em>a</em>sed on <em>a</em> survey of 399 physici<em>a</em>ns, <em>a</em> descriptive <em>a</em>n<em>a</em>lysis of me<em>a</em>sured d<em>a</em>t<em>a</em> w<em>a</em>s done using SPSS 19.0. Pe<em>a</em>rson correl<em>a</em>tion coefficient <em>a</em>n<em>a</em>lysis w<em>a</em>s used to ex<em>a</em>mine the correl<em>a</em>tions between PH <em>a</em>nd the soci<em>a</em>l support r<em>a</em>ting sc<em>a</em>le (SSRS) <em>a</em>nd the demogr<em>a</em>phic v<em>a</em>ri<em>a</em>bles. KMO <em>a</em>nd B<em>a</em>rtlett methods were used to ex<em>a</em>mine the correl<em>a</em>tions between PH <em>a</em>nd SDS (<em>a</em> sc<em>a</em>le to me<em>a</em>sure depression) <em>a</em>nd between PH <em>a</em>nd <em>SAS</em> (<em>a</em> sc<em>a</em>le to me<em>a</em>sure <em>a</em>nxiety). The method of f<em>a</em>ctor <em>a</em>n<em>a</em>lysis w<em>a</em>s used for multicolline<em>a</em>rity tests, <em>a</em>nd multiple stepwise regression <em>a</em>n<em>a</em>lysis w<em>a</em>s used to explore the demogr<em>a</em>phic f<em>a</em>ctors correl<em>a</em>ted with PH <em>a</em>nd SSRS. Two-w<em>a</em>y inter<em>a</em>ctions in moder<em>a</em>ted multiple regression were used to test the moder<em>a</em>ting effect of educ<em>a</em>tion level <em>a</em>nd title on SSRS, SDS, <em>a</em>nd <em>SAS</em>.</Abstr<em>a</em>ctText><Abstr<em>a</em>ctText>Our results indic<em>a</em>te th<em>a</em>t the level of PH is influenced by the <em>a</em>ge, educ<em>a</em>tion, <em>a</em>nd title of <em>a</em> doctor. A physici<em>a</em>n's title is signific<em>a</em>ntly <em>a</em>nd positively correl<em>a</em>ted with PH, but <em>a</em>ge <em>a</em>nd educ<em>a</em>tion <em>a</em>re signific<em>a</em>ntly neg<em>a</em>tively rel<em>a</em>ted. Age, educ<em>a</em>tion, <em>a</em>nd title <em>a</em>lso <em>a</em>ffect the level of SSRS in physici<em>a</em>ns. SSRS is positively correl<em>a</em>ted with <em>a</em>ge, educ<em>a</em>tion, <em>a</em>nd title, <em>a</em>nd SSRS positively influences PH. Educ<em>a</em>tion <em>a</em>nd title h<em>a</em>d signific<em>a</em>nt effects on the moder<em>a</em>ting influences of SSRS, SDS, <em>SAS</em>, <em>a</em>nd PH.</Abstr<em>a</em>ctText><Abstr<em>a</em>ctText>The f<em>a</em>ctors directly <em>a</em>ffecting PH include SSRS, <em>a</em>ge, <em>a</em>nd title, while educ<em>a</em>tion w<em>a</em>s found to be <em>a</em>n indirect influencing f<em>a</em>ctor. To meet go<em>a</em>ls expressed in Chinese government policy rel<em>a</em>ted to these issues, we suggest strengthening the guid<em>a</em>nce of the medi<em>a</em>, introducing l<em>a</em>ws <em>a</em>nd regul<em>a</em>tions on doctor-p<em>a</em>tient risk m<em>a</em>n<em>a</em>gement <em>a</em>nd control, reforming the review mech<em>a</em>nism of hospit<em>a</em>l job titles, improving the educ<em>a</em>tion level of doctors, building <em>a</em> comprehensive ev<em>a</em>lu<em>a</em>tion system of "pr<em>a</em>ctice perform<em>a</em>nce + doctor-p<em>a</em>tient s<em>a</em>tisf<em>a</em>ction", <em>a</em>nd strengthening doctor-p<em>a</em>tient emp<em>a</em>thy. Through such me<em>a</em>sures, the level of PH in physici<em>a</em>ns will improve.</Abstr<em>a</em>ctText>
Publication
Journal: South African Medical Journal
February/4/2018
Abstract
Background. Implanon NXT, a long-acting reversible contraceptive, was introduced in South Africa (SA) in early 2014, aiming to expand the method mix and increase its effectiveness. Initial uptake was high, but has since declined considerably. In these early years after the implant’s introduction, it is important to identify reasons for the decline, and remedy gaps in services. Objectives. To determine periods of use, reasons for the use and early removal of the implant Implanon NXT. Methods. In 2016, we recruited 152 women from six clinics in the City of Johannesburg, and six in North West Province, SA. A semistructured interview was administered to 91 women currently using the implant and 61 previous users. We examined user perspectives, factors influencing women’s experiences with the implant and reasons for discontinuation. Results. The participants’ mean age was 30 years, with only 15% aged <25. Implant uptake was motivated by convenience (less frequent visits required than for short-acting methods) and by favourable views of the method among friends, family and healthcare providers. Only about a quarter of women recalled being counselled pre-insertion about implant effectiveness, and half about side-effects pre-insertion. Among discontinuers, the median time to device removal was 8 months (interquartile range 6 - 12), and this was primarily as a result of side-effects (90%), especially bleeding-pattern changes and headaches. Removals were most common among married and cohabiting women, often ascribed to the effects of bleeding on their sexual relationships. Rumours and misinformation contributed to some removals. Overall, women’s experiences with the implant were rated ‘good’ or ‘very good’ by 74% of those continuing use, many of whom reported not having experienced any side-effects or that these had diminished over time. Conclusion. Levels of acceptability among continuing users were high, mainly linked to the method’s convenience. While early favourable views drove uptake, negative perceptions, if unaddressed, may now undermine services. Deficiencies in counselling around effectiveness and side-effects may extend to contraceptive services more generally. Women require more intensive support when experiencing sideeffects, including effective systematic approaches to ameliorating bleeding and headaches. Implant services could specifically target young women and first-time contraceptive users. These actions together could reverse the persistent decline in implant use in SA.
Publication
Journal: Autophagy
March/22/2019
Abstract
Macroautophagy/autophagy is a cellular process in which cytosolic contents are degraded by lysosome in response to various stress conditions. Apart from its role in the maintenance of cellular homeostasis, autophagy also involves in regulation of cell cycle progression under nutrient-deprivation conditions. However, whether and how autophagy is regulated by the cell cycle especially during mitosis remains largely undefined. Here we show that WIPI2/ATG18B (WD repeat domain, phosphoinositide interacting 2), an autophagy-related (ATG) protein that plays a critical role in autophagosome biogenesis, is a direct substrate of CUL4-RING ubiquitin ligases (CRL4s). Upon mitosis induction, CRL4s are activated via neddylation, and recruit WIPI2 via DDB1 (damage specific DNA binding protein 1), leading to polyubiquitination and proteasomal degradation of WIPI2 and suppression of autophagy. The WIPI2 protein level and autophagy during mitosis could be rescued by knockdown of CRL4s or treatment with MLN4924/Pevonedistat, a selective inhibitor of CRLs, via suppression of NAE1 (NEDD8 activating enzyme E1 subunit 1). Moreover, restoration of WIPI2 rescues autophagy during mitosis and leads to mitotic slippage and cell senescence. Our study thus discovers a novel function of CRL4s in autophagy by targeting WIPI2 for polyubiquitination and proteasomal degradation during mitosis. Abbreviations: ACTB, actin beta; ATG, autophagy-related; AMPK, AMP-activated protein kinase; AURKB/ARK2, aurora kinase B; BafA1, bafilomycin A1; CCNB1, cyclin B1; CDK1, cyclin dependent kinase 1; CHX, cycloheximide; CQ, chloroquine; CRL4s, CUL4-RING ubiquitin ligases; DDB1, damage specific DNA binding protein 1; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; GFP, green fluorescent protein; GST, glutathione S-transferase; MAP1LC3B/LC3B, microtubule associated protein 1 light chain 3 beta; STK11/LKB1,serine/threonine kinase 11; MTORC1/MTOR complex 1, mechanistic target of rapamycin kinase complex 1; NAE1, NEDD8 activating enzyme E1 subunit 1; NOC, nocodazole; RING, really interesting new gene; RBX1, ring-box 1; SA-GLB1/β-gal, senescence-associated galactosidase beta 1; TSC2, TSC complex subunit 2; TUBA, tubulin alpha; WIPI2, WD repeat domain, phosphoinositide interacting 2.
Publication
Journal: Optics Express
May/10/2015
Abstract
In this work we present for the first time, to the best of our knowledge, a stretched-pulse mode-locked fiber laser based on topological insulator. As a saturable absorber (SA) a ~0.5 mm thick lump of antimony telluride (Sb2Te3) deposited on a side-polished fiber was used. Such a SA introduced 6% modulation depth with 43% of non-saturable losses, which is sufficient for supporting stretched-pulse mode-locking. The ring laser resonator based on Er-doped active fiber with managed intracavity dispersion was capable of generating ultrashort optical pulses with full width at half maximum (FWHM) of 30 nm centered at 1565 nm. The pulses with duration of 128 fs were repeated with a frequency of 22.32 MHz.
Publication
Journal: Shock
October/18/2004
Abstract
Lipopolysaccharide (LPS), the gram-negative bacterial cell wall component, induces tolerance to a secondary challenge of LPS in macrophages (Mphi) as evidenced by reduced inflammatory mediator production. However, it is uncertain if heat-killed (HK) gram-positive bacteria Staphylococcus aureus (Sa) can induce a similar tolerance and alter responses to LPS. We hypothesized that HKSa induces homologous tolerance and cross tolerance to LPS stimulation in human promonocytic THP-1 cells. We measured TNF-alpha, TxB2, and IFN-gamma production and the phosphorylation of p38, JNK, and ERK-1/2 in human promonocytic THP-1 cells. HKSa (10 microg/mL) significantly stimulated naive (nonpretreated) cell TNF-alpha (P<0.05) and TxB2 production (P<0.05). However, HKSa-pretreated cells challenged secondarily with HKSa (10 microg/mL) exhibited a decrease in the production of TNF-alpha (89 +/- 5%, P<0.05) and TxB2 (85 +/- 3%, P<0.05) compared with HKSa-stimulated naive cells. By contrast, secondary LPS challenge of HKSa-pretreated cells augmented TNF-alpha (41 +/- 3%, P<0.05) and TxB2 (42 +/- 6%, P<0.05) compared with LPS-stimulated naive cells. In naive cells, HKSa and LPS stimulation also significantly phosphorylated the mitogen-activated kinases (MAPKs) p38, JNK, and ERK-1/2 (P<0.005) compared with basal levels. HKSa and LPS induced homologous tolerance as evidenced by the down-regulation of the three MAPK (P<0.05), thus paralleling data on mediator production. HKSa-pretreated cells' priming responses to LPS correlated with augmented phosphorylation of JNK and p38 (P<0.05), whereas ERK-1/2 phosphorylation remained down-regulated. In contrast to TNF-alpha and TxB2 production, HKSa-induced IFN-gamma was up-regulated (26 +/- 5%) in HKSa-pretreated cells compared with HKSa-stimulated naive cells. IFN-gamma antibody exhibited reversed priming in HKSa-pretreated cells as evidenced by a reduction in TNF-alpha. Exogenous human IFN-gamma- (1 microg/mL) and HKSa-pretreated cells secondarily stimulated with HKSa did not prevent the induction of tolerance. In contrast, exogenous IFN-gamma pretreatment prevented the induction of LPS homologous tolerance resulting in an increase in TNF-alpha production. The data demonstrate that HKSa induces homologous tolerance but causes priming to LPS.
Publication
Journal: Acta Veterinaria Hungarica
April/22/2016
Abstract
Infection of host cells with the influenza virus is mediated by specific interactions between the viral haemagglutinin (HA) and cell oligosaccharides containing sialic acid (SA) residues. Avian and human influenza viruses bind to alpha-2, 3 and alpha-2, 6 sialic acid-linked receptors, respectively. To date, there have been no detailed tissue distribution data on alpha-2, 3 and alpha-2, 6 sialic acid-linked receptors in the domestic cat, a relatively new mammalian host for influenza virus infections. In this study, the tissue distribution of human and avian type sialic acid influenza receptors was determined in various organs (respiratory tract, gastrointestinal tract, brain, cerebellum, spleen, kidney, heart and pancreas) of domestic cat by binding with the lectins Maackia amurensis agglutinin II (MAA II) and Sambucus nigra agglutinin (SNA), respectively. The results revealed that both alpha-2, 3 and alpha-2, 6 sialic acid-linked receptors were extensively detected in the trachea, bronchus, lung, kidney, spleen, pancreas and gastrointestinal tract. Endothelial cells of gastrointestinal tract organs were negative for alpha-2, 3 sialic acid-linked receptors in cats. The presence of alpha-2, 3 and alpha-2, 6 sialic acid-linked receptors in the major organs examined in the present study suggests that each major organ may be affected by influenza virus infection. Because of receptor distribution in the gastrointestinal tract, the experimental infection of cats with human influenza virus may be relatively easy while their infection with avian influenza virus may be difficult. These data can explain the involvement of multiple organs in influenza virus infection and should help investigators interpret the results obtained when cats are infected with influenza virus and estimate the risk of infection between cats and humans.
Publication
Journal: Neurobiology of Learning and Memory
March/2/2017
Abstract
Synaptopodin (SP) is a proline-rich actin-associated protein essential for the formation of a spine apparatus (SA) in dendritic spines. The SA consists of stacks of smooth endoplasmic reticulum (sER) contiguous with the meshwork of somatodendritic ER. Spines of SP-deficient mice contain sER but no SA, demonstrating that SP is necessary for the assembly of ER cisterns into the more complex SA organelle. Although the SA was described decades ago, its function was difficult to investigate and remained elusive, in part because reliable markers for the SA were missing. After SP was identified as an essential component and a reliable marker of the SA, a role of SP/SA in hippocampal synaptic plasticity could be firmly established using loss-of-function approaches. Further studies revealed that SP/SA participate in the regulation of Caan plasticity and in activity-dependent changes in the spine actin cytoskeleton. In this review we are summarizing recent progress made on SP/SA in Hebbian plasticity and discuss open questions such as causality, spatiotemporal dynamics and complementarity of SP/SA-dependent mechanisms. We are proposing that computational modeling of spine Caaling and actin remodeling pathways could address some of these issues and could indicate future research directions. Moreover, reaction-diffusion simulations could help to identify key feedforward and feedback regulatory motifs regulating the switch between an LTP and an LTD signaling module in SP/SA-containing spines, thus helping to find a unified view of SP/SA action in Hebbian plasticity.
Publication
Journal: OncoTargets and Therapy
February/18/2019
Abstract
Breast cancer (BC) has been the commonest malignant tumor with a low survival rate among woman. Long non-coding RNA hypoxia-inducible factor-1 alpha antisense RNA-2 (HIF1A-AS2) was correlated with various cancers.The study aimed to investigate the roles and related underlying molecular mechanisms of HIF1A-AS2 in BC.Target relationships were speculated by Targetscan 7.0 and confirmed by dual luciferase reporter assay. Proteins levels were monitored by RT-qPCR, Western blot and immunohistochemistry assays. CCK-8 assay, SA-β-gal staining and transwell assay were used to detect proliferation, senescence and invasion, respectively. Xenograft nude mice were put into use to evaluate the tumor growth and motility.The present study exhibited that HIF1A-AS2 and hypoxia-inducible factor-1 alpha (HIF-1α) were upregulated while miR-548c-3p was downregulated in MDA-MB-231, MCF-7, ZR-75-1, and BT-549 BC cell lines. Bioinformatics analysis showed HIF1A-AS2 and HIF-1α were two targets of miR-548c-3p, and the target relationship was further confirmed by dual luciferase reporter assay. Moreover, knockdown of HIF1A-AS2 by shRNA (sh-HIF1A-AS2) markedly elevated miR-548c-3p level, and the enhanced miR-548c-3p noticeably suppressed cell proliferation, invasion, and epithelial-mesenchymal transition, and promoted senescence in vitro. In addition, overexpression of HIF-1α promoted MCF-7 cell invasion. Intriguingly, low expression of HIF1A-AS2 reduced HIF-1α level by upregulating the expression of miR-548c-3p. Furthermore, experiment in xenograft nude mice has indicated that sh-HIF1A-AS2 inhibited tumor growth and motility by targeting miR-548c-3p through regulating HIF-1α/vascular endothelial growth factor (VEGF) pathway in vivo.The inhibitive effect of HIF-1α/VEGF pathway by sh-HIF1A-AS2 through targeting miR-548c-3p plays crucial regulatory roles in BC. Therefore, designing targeted drugs against HIF1A-AS2 provides a new direction for the treatment of BC.
Publication
Journal: Journal of Genetics and Genomics
April/8/2013
Abstract
Expression-independent gene or polyadenylation [poly(A)] trapping is a powerful tool for genome-wide mutagenesis regardless of whether a targeted gene is expressed. Although a number of poly(A)-trap vectors have been developed for the capture and mutation of genes across a vertebrate genome, further efforts are needed to avoid the 3'-terminal insertion bias and the splice donor (SD) read-through, and to improve the mutagenicity. Here, we present a Sleeping Beauty (SB) transposon-based vector that can overcome these limitations through the inclusion of three functional cassettes required for gene-finding, gene-breaking and large-scale mutagenesis, respectively. The functional cassette contained a reporter/selective marker gene driven by a constitutive promoter in front of a strong SD signal and an AU-rich RNA-destabilizing element (ARE), which greatly reduced the SD read-through events, except that the internal ribosomal entry site (IRES) element was introduced in front of the SD signal to overcome the phenomenon of 3'-bias gene trapping. The breaking cassette consisting of an enhanced splicing acceptor (SA), a poly(A) signal coupled with a transcriptional terminator (TT) effectively disrupted the transcription of trapped genes. Moreover, the Hsp70 promoter from tilapia genome was employed to drive the inducible expression of SB11, which allows the conditional remobilization of a trap insert from a non-coding region. The combination of three cassettes led to effective capture and disruption of endogenous genes in HeLa cells. In addition, the Cre/LoxP system was introduced to delete the Hsp70-SB11 cassette for stabilization of trapped gene interruption and biosafety. Thus, this poly(A)-trap vector is an alternative and effective tool for identification and mutation of endogenous genes in cells and animals.
Publication
Journal: Cell Cycle
February/10/2014
Publication
Journal: Brain and Language
June/30/2003
Abstract
Two patients are described with grammatical class dissociation: CG, a semantic-dementia patient who presented a disproportionate impairment of nouns compared to verbs; SA, a patient with a left parietal lesion who presented impaired sentence production and a disproportionate deficit for verbs compared to nouns. The results are discussed within the current models on semantic memory and lexical access.
Publication
Journal: Nanotechnology
March/4/2018
Abstract
In this paper, a WSe2 film prepared by chemical vapor deposition (CVD) is transferred onto a tapered fiber, and a WSe2 saturable absorber (SA) is fabricated. In order to measure the third-order optical nonlinearity of the WSe2, the Z-scan technique is applied. The modulation depth of the WSe2 SA is measured as being 21.89%. Taking advantage of the remarkable nonlinear absorption characteristic of the WSe2 SA, a mode-locked erbium-doped fiber laser is demonstrated at 1557.4 nm with a bandwidth of 25.8 nm and signal to noise ratio of 96 dB. To the best of our knowledge, the pulse duration of 163.5 fs is confirmed to be the shortest compared with previous mode-locked fiber lasers based on transition-metal dichalcogenides SAs. These results indicate that WSe2 is a powerful competitor in the application of ultrashort pulse lasers.
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