Role of flotillins in the endocytosis of GPCR in salivary gland epithelial cells

Park, M.Y.,Kim, N.,Wu, L.L.,Yu, G.Y.,Park, K. Academic Press 2016 Biochemical and biophysical research communication Vol.476 No.4

Endocytosis has numerous functions in cellular homeostasis. Defects in the endocytic pathway of receptors may lead to dysfunction of salivary gland secretion. Therefore, elucidating the complex mechanisms of endocytosis may facilitate solutions for disease treatment and prevention. The muscarinic type 3 receptor (M3R), a G-protein-coupled receptor (GPCR) located in the plasma membrane, is involved in numerous physiological activities such as smooth muscle contraction and saliva secretion. M3R enters cells through clathrin-mediated endocytosis (CME), while flotillins (flot-1 and -2), highly conserved proteins residing in lipid-raft microdomains, make use of clathrin-independent endocytosis (CIE) for their internalization. Since these two proteins use two discrete pathways for endocytic entry, the association of flotillins with CME is poorly understood. We examined whether flotillins play a role in CME of M3R using immunoblotting, immunocytochemistry, confocal immunofluorescence microscopy, co-immunoprecipitation, and RNA interference techniques in secretory epithelial cells. Upon stimulation with a cholinergic agonist, M3R, flot-1, and flot-2 each internalized from the plasma membrane into intracellular sites. The addition of chlorpromazine and cytochalasin D, well-known inhibitors of CME, inhibited internalization of M3R via CME. Filipin III and methyl-β-cyclodextrin (mβCD) acting as lipid raft inhibitors disrupted internalization of flot-½ via CIE. Interestingly, filipin III and mβCD slightly reduced expression level of M3R whereas chlorpromazine and cytochalasin D did not affect internalization of the flotillin isoforms. M3R and flot-½ colocalized and interacted with each other as they entered the cytosol during limited periods of incubation. Moreover, knockdown of flot-1 or -2 by flotillin-specific siRNA prevented internalization and reduced the endocytic efficiency of M3R. Our results suggest that flot-1 and -2 are partially involved in CME of M3R by facilitating its internalization.

THE EVOLUTION OF THE GALAXY STELLAR MASS FUNCTION AT<i>z</i>= 4-8: A STEEPENING LOW-MASS-END SLOPE WITH INCREASING REDSHIFT

Song, Mimi,Finkelstein, Steven L.,Ashby, Matthew L. N.,Grazian, A.,Lu, Yu,Papovich, Casey,Salmon, Brett,Somerville, Rachel S.,Dickinson, Mark,Duncan, K.,Faber, Sandy M.,Fazio, Giovanni G.,Ferguson, He American Astronomical Society 2016 The Astrophysical Journal Vol.825 No.1

<P>We present galaxy stellar mass functions (GSMFs) at z = 4-8 from a rest-frame ultraviolet (UV) selected sample of similar to 4500 galaxies, found via photometric redshifts over an area of similar to 280 arcmin(2) in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS)/Great Observatories Origins Deep Survey (GOODS) fields and the Hubble Ultra Deep Field. The deepest Spitzer/IRAC data to date and the relatively large volume allow us to place a better constraint at both the low- and high-mass ends of the GSMFs compared to previous space-based studies from pre-CANDELS observations. Supplemented by a stacking analysis, we find a linear correlation between the rest-frame UV absolute magnitude at 1500 angstrom (M-UV) and logarithmic stellar mass (log M-*) that holds for galaxies with log(M-*/M-circle dot) less than or similar to 10. We use simulations to validate our method of measuring the slope of the log M-*-M-UV relation, finding that the bias is minimized with a hybrid technique combining photometry of individual bright galaxies with stacked photometry for faint galaxies. The resultant measured slopes do not significantly evolve over z = 4-8, while the normalization of the trend exhibits a weak evolution toward lower masses at higher redshift. We combine the log M-*-M-UV distribution with observed rest-frame UV luminosity functions at each redshift to derive the GSMFs, finding that the low-mass-end slope becomes steeper with increasing redshift from alpha = -1.55(-0.07)(+0.08) at z = 4 to alpha = -2.25(-0.35)(+0.72) at z = 8. The inferred stellar mass density, when integrated over M-* = 10(8)-10(13) M-circle dot, increases by a factor of 10(-2)(+30) between z = 7 and z = 4 and is in good agreement with the time integral of the cosmic star formation rate density.</P>

DHS-21, a dicarbonyl/l-xylulose reductase (DCXR) ortholog, regulates longevity and reproduction in Caenorhabditis elegans

Son, L.T.,Ko, K.M.,Cho, J.H.,Singaravelu, G.,Chatterjee, I.,Choi, T.W.,Song, H.O.,Yu, J.R.,Park, B.J.,Lee, S.K.,Ahnn, J. North-Holland Pub ; Elsevier Science Ltd 2011 FEBS letters Vol.585 No.9

Dicarbonyl/l-xylulose reductase (DCXR) converts l-xylulose into xylitol, and reduces various α-dicarbonyl compounds, thus performing a dual role in carbohydrate metabolism and detoxification. In this study, we identified DHS-21 as the only DCXR ortholog in Caenorhabditis elegans. The dhs-21 gene is expressed in various tissues including the intestine, gonadal sheath cells, uterine seam (utse) cells, the spermathecal-uterus (sp-ut) valve and on the plasma membrane of spermatids. Recombinant DHS-21 was shown to convert l-xylulose to xylitol using NADPH as a cofactor. Dhs-21 null mutants of C. elegans show defects in longevity, reproduction and egg-laying. Knock-down of daf-16 and elt-2 transcription factors affected dhs-21 expression. These results suggest that DHS-21 is a bona fide DCXR of C. elegans, essential for normal life span and reproduction.

New self-activated eulytite-type compounds of M₇Zr(PO₄)₆ (M=Ca, Sr, Ba)

Qin, L.,Wei, D.,Huang, Y.,Kim, S.I.,Yu, Y.M.,Seo, H.J. Elsevier Sequoia 2013 Journal of alloys and compounds Vol.574 No.-

Eulytite-type orthophosphates M<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> (M=Ca, Sr, Ba) were prepared by conventional high temperature solid-state reaction. Sr<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> and Ba<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> crystallize in the pure eulytite-type phase with cubic space group (I4@?3d). The impurity phase β-Ca<SUB>3</SUB>(PO<SUB>4</SUB>)<SUB>2</SUB> was inevitably coexisted with the Ca<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> phase. The luminescence properties are investigated by UV-VUV excitation and emission spectroscopy and X-ray-excited luminescence (XEL) spectroscopy. The broad excitation and emission bands are observed due to the charge transfer transition from Zr<SUP>4+</SUP> to O<SUP>2-</SUP> in M<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> (M=Ca, Sr, Ba) eulytite. The characteristics of the phosphors including the luminescence mechanism are explained by Stokes shift, decay curves, and CIE color coordinates. The Sr<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>3</SUB> and Ba<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>3</SUB> phosphors exhibit unusual spectral features with the emission bands at 470 and 480nm, respectively. The weak luminescence centered at 495nm is observed in the Ca<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> eulytite with lifetime of 4.67μs. The unusual self-activated luminescence is discussed on the base of the crystal structure of eulytite.

DNA Polymorphisms in SREBF1 and FASN Genes Affect Fatty Acid Composition in Korean Cattle (Hanwoo)

Bhuiyan, M.S.A.,Yu, S.L.,Jeon, J.T.,Yoon, D.,Cho, Y.M.,Park, E.W.,Kim, N.K.,Kim, K.S.,Lee, J.H. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.6

Sterol regulatory element binding factor 1 (SREBF1) and fatty acid synthase (FASN) genes play an important role in the biosynthesis of fatty acids and cholesterol, and in lipid metabolism. This study used polymorphisms in the intron 5 of bovine SREBF1 and in the thioesterase (TE) domain of FASN genes to evaluate their associations with beef fatty acid composition. A previously identified 84-bp indel (L: insertion/long type and S: deletion/short type) of the SREBF1 gene in Korean cattle had significant associations with the concentration of stearic (C18:0), linoleic (C18:2) and polyunsaturated fatty acids (PUFA). The stearic acid concentration was 6.30% lower in the SS than the LL genotype (p<0.05), but the linoleic and PUFA contents were 11.06% and 12.20% higher in SS compared to LL (p<0.05). Based on the sequence analysis, five single nucleotide polymorphisms (SNPs) g.17924G>A, g.18043C>T, g.18440G>A, g.18529G>A and g.18663C>T in the TE domain of the FASN gene were identified among the different cattle breeds studied. Among these, only g.17924 G>A and g.18663C>T SNPs were segregating in the Hanwoo population. The g.17924G>A SNP is a non-synonymous mutation (thr2264ala) and was significantly associated with the contents of palmitic (C16:0) and oleic acid (C18:1). The oleic acid concentration was 3.18% and 2.79% higher in Hanwoo with the GG genotype than the AA and AG genotypes, respectively (p<0.05), whereas the GG genotype had 3.8% and 4.01% lower palmitic acid than in those cattle with genotype AA and AG, respectively (p<0.05). Tissue expression data showed that SREBFI and FASN genes were expressed in a variety of tissues though they were expressed preferentially in different muscle tissues. In conclusion, the 84-bp indel of SREBF1 and g.17924G>A SNP of the FASN gene can be used as DNA markers to select Hanwoo breeding stock for fatty acid composition.

High Sustained Virologic Response with Daclatasvir plus Asunaprevir in HCV GT-1b Chinese, Korean and Taiwanese without Baseline NS5A Polymorphisms

( F. Mcphee ),( L. Wei ),( Q. Xie ),( Y. Suzuki ),( J. Toyota ),( Y. Karino ),( K. Chayama ),( Y. Kawakami ),( M. L. Yu ),( S. H. Ahn ),( N. Zhou ),( H. Kumada ) 대한간학회 2016 춘·추계 학술대회 (KASL) Vol.2016 No.1

Aims: Daclatasvir (DCV) plus asunaprevir (ASV) has demonstrated highsustained virologic response (SVR) in HCV genotype (GT-)1b infection.NS5A-Y93H and NS5A-L31 resistance-associated polymorphisms(RAPs) to DCV are known to impact DCV+ASV response in GT-1b-infectedJapanese. The effect of RAPs on SVR at posttreatment week12 (SVR12) to DCV+ASV was explored in mainland Chinese, Korean,and Taiwanese.Methods: Pooled data from 2 studies of DCV (60 mg daily) + ASV(100 mg capsule, twice-daily) for 24 weeks in GT-1b-infected interferon/ribavirin-naive and -experienced patients from mainland China,Korea, and Taiwan. Similar Japanese data (4 studies; n=445) werepooled for comparison. SVR12 with versus without baseline Y93Hand/or L31 RAPs was compared by age (<65 vs ≥65 years), cirrhosisstatus, and baseline HCV-RNA.Results: SVR12 and baseline NS5A sequences were available for 282patients (126 mainland Chinese [45%〕, 80 Koreans [28%〕, 76Taiwanese [27%〕). NS5A-Y93H and/or -L31 RAPs were observed pretreatmentin 8% mainland Chinese, 14% Korean, and 18%Taiwanese patients, compared with 19% in Japanese. SVR12 in allnon-Japanese patients is shown (Figure); rates were broadly similarbetween countries and with Japanese data (Japanese: 96% overallwithout RAPs, 41% with RAPs). Responses were lower among patientswith baseline RAPs. By contrast, SVR12 in patients without RAPs washigh (92-100%), irrespective of cirrhosis, age, or baseline HCV-RNA.Conclusions: At least 95% of HCV GT-1b-infected patients from mainlandChina, Korea or Taiwan without baseline NS5A-Y93H or -L31polymorphisms who had HCV-RNA ≤7 log10 IU/mL achieved SVR12on DCV+ASV, regardless of cirrhosis status and age.

The Origin of Coercivity Enhancement of Sintered NdFeB Magnets Prepared by Dy Addition

N. J. Yu,M. X. Pan,P. Y. Zhang,H. L. Ge 한국자기학회 2013 Journal of Magnetics Vol.18 No.3

The effect of Dy addition on the microstructure and magnetic properties of the sintered NdFeB magnets was investigated. The results of the microstructure analysis showed that Dy-free and Dy-doped samples are composed of Nd₂Fe ₁₄B (P42/mnm) and a trace of Nd-rich phase. Dy addition reduces significantly the pole density factor of (004), (006) and (008) crystal faces as estimated by the Horta formula. Accordingly, the coercivity of the Dy-doped sample increases from 2038 kA·m?1 up to 2288 kA·m?1. The Hcj(T)/Ms(T) versus /Ms(T) (Kronmuller-plot) behavior shows that the nucleation is the dominating mechanism for the magnetization reversal in these two kinds of magnets, and two microstructural parameters of αk and Neff are obtained. The Kronmuller-Plot gives evidence for an increase of the αk responsible for an increase of the coercivity as the result of the increase of the magnetic field as the magnetic domain reversed.

High-efficiency p–i–n organic light-emitting diodes with a novel n-doping electron transport layer

Wei Xu,M.A. Khan,Yu Bai,X.Y. Jiang,Z.L. Zhang,W.Q. Zhu 한국물리학회 2009 Current Applied Physics Vol.9 No.4

We demonstrate p–i–n organic light-emitting diodes (OLEDs) incorporating an n-doping transport layer which comprises 8-hydroxy-quinolinato lithium (Liq) doped into 4'7-diphyenyl-1,10-phenanthroline (Bphen) as ETL and a p-doping transport layer which includes tetrafluro-tetracyano-quinodimethane (F4-TCNQ) doped into 4,4',4''-tris(3-methylphenylphenylamono) triphenylamine (m-MTDATA). In order to examine the improvement in the conductivity of transport layers, hole-only and electron-only devices are fabricated. The current and power efficiency of organic light-emitting diodes have been improved significantly after introducing a novel n-doping (Bphen: 33 wt% Liq) layer as an electron transport layer (ETL) and a p-doping layer composed of m-MTDATA and F4-TCNQ as a hole transport layer (HTL). Compared with the control device (without doping), the current efficiency and power efficiency of Device C (most efficient) is enhanced by approximately 51% and 89%, respectively, while driving voltage is reduced by 29%. This improvement is attributed to the improved conductivity of the transport layers that leads to the efficient charge balance in the emission zone. We demonstrate p–i–n organic light-emitting diodes (OLEDs) incorporating an n-doping transport layer which comprises 8-hydroxy-quinolinato lithium (Liq) doped into 4'7-diphyenyl-1,10-phenanthroline (Bphen) as ETL and a p-doping transport layer which includes tetrafluro-tetracyano-quinodimethane (F4-TCNQ) doped into 4,4',4''-tris(3-methylphenylphenylamono) triphenylamine (m-MTDATA). In order to examine the improvement in the conductivity of transport layers, hole-only and electron-only devices are fabricated. The current and power efficiency of organic light-emitting diodes have been improved significantly after introducing a novel n-doping (Bphen: 33 wt% Liq) layer as an electron transport layer (ETL) and a p-doping layer composed of m-MTDATA and F4-TCNQ as a hole transport layer (HTL). Compared with the control device (without doping), the current efficiency and power efficiency of Device C (most efficient) is enhanced by approximately 51% and 89%, respectively, while driving voltage is reduced by 29%. This improvement is attributed to the improved conductivity of the transport layers that leads to the efficient charge balance in the emission zone.

Several factors affecting hypericin production of Hypericum perforatum during adventitious root culture in airlift bioreactors

Wu, S. Q.,Yu, X. K.,Lian, M. L.,Park, S. Y.,Piao, X. C. POLISH ACADEMY SCIENCES WARSAW 2014 Acta physiologiae plantarum Vol.36 No.4

Hypericum perforatum L. is a traditional medicinal plant for the treatment of depression and wound healing, and hypericin is one of the main effective active substances. To optimize the culture system for producing hypericin in adventitious root, this study used balloon-type airlift bioreactors to investigate the effect of air volume, inoculation density, indole-3-butyric acid (IBA) concentration and methyl jasmonate (MeJA) concentration on hypericin content and productivity during adventitious root culture. Hypericin content and productivity were improved with increasing air volume, and 0.1 vvm (air volume/culture volume/min) was optimal for hypericin production. Inoculation density also had a great effect on hypericin accumulation. Hypericin content and productivity were favorable in an inoculation density of 5.0 g l(-1) and decreased when inoculation densities were lower or higher than 5.0 g l(-1). Furthermore, 1.25 mg l(-1) IBA enhanced hypericin content and productivity, but too low (a parts per thousand currency sign0.50 mg l(-1)) or too high (a parts per thousand yen1.50 mg l(-1)) IBA concentrations decreased hypericin accumulation. MeJA concentration significantly affected biomass accumulation and hypericin production. The biomass decreased and hypericin production increased with increasing MeJA concentration. Optimum hypericin content (1.61 mg g(-1) DW) and productivity (15.57 mg l(-1)) were obtained at 350 mu M MeJA. The hypericin content in bioreactor-grown adventitious roots was lower than in 3-year field-grown plants, but significantly higher than that in in vitro-grown plantlets and 1-year field-grown plants. Thus, the bioreactor culture of adventitious roots can realize rapid and mass production of hypericin in H. perforatum.

Ferromagnetism in Zn_1–<i>x</i>Mn_<i>x</i>O Nanoparticles Prepared by Ball Milling

Manh, T. V.,Phan, T. L.,Lee, B. W.,Liu, Chunli,Ho, T. A.,Thanh, T. D.,Vuong, N. M.,Yu, S. C. IEEE 2015 IEEE transactions on magnetics Vol.51 No.11

<P>Previous studies pointed out that ferromagnetism in Mn-doped ZnO was related to exchange interactions between Mn ions mediated by lattice defects. This means that it is possible to modify a Mn-doped ZnO paramagnet to a ferromagnet by creating lattice defects in it. The present work starts from a paramagnetic Zn0.98Mn0.02O sample prepared by solid-state reaction and then creates more defects upon mechanical milling. By changing the milling time (t(m)) from 0.5 to 20 h, we produced nanocrystalline (NC) samples with average crystallite sizes (d) ranging from 30 to 157 nm. The d decrease generated lattice strain and defects. This broadens and blurs the lines of Raman scattering and electron spin resonance (ESR) spectra. Interestingly, magnetization studies versus magnetic field revealed the samples with d <= 150 nm exhibiting room-temperature ferromagnetic (FM) order. The FM order became largest as d = 72 nm, corresponding to a saturation magnetization of M-s approximate to 0.006 emu/g. Apart from this d value, M-s would be gradually decreased. X-ray absorption fine structure (XAFS) spectra revealed a coexistence of Mn2+ and Mn3+ ions in the samples. Their concentration ratio was slightly changed with decreasing d, due to the slight shift of the absorption edge. With the features of Fourier-transformed XAFS and ESR spectra, we believe that ferromagnetism in the NC samples is related to oxygen vacancies residing on the surface of nanoparticles. Local lattice distortions can lead to zinc interstitials for the samples d < 72 nm, which decreases M-s.</P>