HSPB1 as a novel regulator of ferroptotic cancer cell death

Ferroptosis is an iron-dependent form of non-apoptotic cell death, but its molecular mechanism remains largely unknown. Here, we demonstrate that heat shock protein beta-1 (HSPB1) is a negative regulator of ferroptotic cancer cell death. Erastin, a specific ferroptosis-inducing compound, stimulates heat shock factor 1 (HSF1)-dependent HSPB1 expression in cancer cells. Knockdown of HSF1 and HSPB1 enhances erastin-induced ferroptosis, whereas heat shock pretreatment and overexpression of HSPB1 inhibits erastin-induced ferroptosis. Protein kinase C-mediated HSPB1 phosphorylation confers protection against ferroptosis by reducing iron-mediated production of lipid reactive oxygen species. Moreover, inhibition of the HSF1-HSPB1 pathway and HSPB1 phosphorylation increases the anticancer activity of erastin in human xenograft mouse tumor models. Our findings reveal an essential role for HSPB1 in iron metabolism with important effects on ferroptosis-mediated cancer therapy.

A Fas-associated protein factor, FAF1, potentiates Fas-mediated apoptosis

Fas, a member of the tumor necrosis factor receptor family, can induce apoptosis when activated by Fas ligand binding or anti-Fas antibody crosslinking. Genetic studies have shown that a defect in Fas-mediated apoptosis resulted in abnormal development and function of the immune system in mice. A point mutation in the cytoplasmic domain of Fas (a single base change from T to A at base 786), replacing isoleucine with asparagine, abolishes the signal transducing property of Fas. Mice homozygous for this mutant allele (lprcg/lprcg mice) develop lymphadenopathy and a lupus-like autoimmune disease. Little is known about the mechanism of signal transduction in Fas-mediated apoptosis. In this study, we used the two-hybrid screen in yeast to isolate a Fas-associated protein factor, FAF1, which specifically interacts with the cytoplasmic domain of wild-type Fas but not the lprcg-mutated Fas protein. This interaction occurs not only in yeast but also in mammalian cells. When transiently expressed in L cells, FAF1 potentiated Fas-induced apoptosis. A search of available DNA and protein sequence data banks did not reveal significant homology between FAF1 and known proteins. Therefore, FAF1 is an unusual protein that binds to the wild type but not the inactive point mutant of Fas. FAF1 potentiates Fas-induced cell killing and is a candidate signal transducing molecule in the regulation of apoptosis.

John J, Sulak L, Zou D, Alimena J, Berry E, Bhattacharya S, Cutts D, Dhingra N, Ferapontov A, Garabedian A, Hakala J, Heintz U, Laird E, Landsberg G, Mao Z, Narain M, Piperov S, Sagir S, Syarif R, Breedon R, Breto G, De La Barca Sanchez MC, Chauhan S, Chertok M, Conway J, Conway R, Cox PT, Erbacher R, Funk G, Gardner M, Ko W, Lander R, Mulhearn M, Pellett D, Pilot J, Ricci-Tam F, Shalhout S, Smith J, Squires M, Stolp D, Tripathi M, Wilbur S, Yohay R, Bravo C, Cousins R, Everaerts P, Farrell C, Florent A, Hauser J, Ignatenko M, Saltzberg D, Schnaible C, Valuev V, Weber M, Burt K, Clare R, Ellison J, Gary JW, Hanson G, Heilman J, Ivova PANEVA M, Jandir P, Kennedy E, Lacroix F, Long OR, Luthra A, Malberti M, Negrete MO, Shrinivas A, Wei H, Wimpenny S, Yates BR, Branson JG, Cerati GB, Cittolin S, D’Agnolo RT, Derdzinski M, Holzner A, Kelley R, Klein D, Letts J, Macneill I, Olivito D, Padhi S, Pieri M, Sani M, Sharma V, Simon S, Tadel M, Tu Y, Vartak A, Wasserbaech S, Welke C, Würthwein F, Yagil A, Zevi Della Porta G, Bradmiller-Feld J, Campagnari C, Dishaw A, Dutta V, Flowers K, Franco Sevilla M, Geffert P, George C, Golf F, Gouskos L, Gran J, Incandela J, Mccoll N, Mullin SD, Mullin SD, Richman J, Stuart D, Suarez I, West C, Yoo J, Anderson D, Apresyan A, Bornheim A, Bunn J, Chen Y, Duarte J, Mott A, Newman HB, Pena C, Pierini M, Spiropulu M, Vlimant JR, Xie S, Zhu RY, Andrews MB, Azzolini V, Calamba A, Carlson B, Ferguson T, Paulini M, Russ J, Sun M, Vogel H, Vorobiev I, Cumalat JP, Ford WT, Gaz A, Jensen F, Johnson A, Krohn M, Mulholland T, Nauenberg U, Stenson K, Wagner SR, Alexander J, Chatterjee A, Chaves J, Chu J, Dittmer S, Eggert N, Mirman N, Nicolas Kaufman G, Patterson JR, Rinkevicius A, Ryd A, Skinnari L, Soffi L, Sun W, Tan SM, Teo WD, Thom J, Thompson J, Tucker J, Weng Y, Wittich P, Abdullin S, Albrow M, Apollinari G, Banerjee S, Bauerdick LAT, Beretvas A, Berryhill J, Bhat PC, Bolla G, Burkett K, Butler JN, Cheung HWK, Chlebana F, Cihangir S, Elvira VD, Fisk I, Freeman J, Gottschalk E, Gray L, Green D, Grünendahl S, Gutsche O, Hanlon J, Hare D, Harris RM, Hasegawa S, Hirschauer J, Hu Z, Jayatilaka B, Jindariani S, Johnson M, Joshi U, Jung AW, Klima B, Kreis B, Lammel S, Linacre J, Lincoln D, Lipton R, Liu T, Lopes De Sá R, Lykken J, Maeshima K, Marraffino JM, Martinez Outschoorn VI, Maruyama S, Mason D, McBride P, Merkel P, Mishra K, Mrenna S, Nahn S, Newman-Holmes C, O’Dell V, Pedro K, Prokofyev O, Rakness G, Sexton-Kennedy E, Soha A, Spalding WJ, Spiegel L, Strobbe N, Taylor L, Tkaczyk S, Tran NV, Uplegger L, Vaandering EW, Vernieri C, Verzocchi M, Vidal R, Weber HA, Whitbeck A, Acosta D, Avery P, Bortignon P, Bourilkov D, Carnes A, Carver M, Curry D, Das S, Field RD, Furic IK, Gleyzer SV, Hugon J, Konigsberg J, Korytov A, Kotov K, Low JF, Ma P, Matchev K, Mei H, Milenovic P, Mitselmakher G, Rank D, Rossin R, Shchutska L, Snowball M, Sperka D, Terentyev N, Thomas L, Wang J, Wang S, Yelton J, Hewamanage S, Linn S, Markowitz P, Martinez G, Rodriguez JL, Adams JR, Ackert A, Adams T, Askew A, Bein S, Bochenek J, Diamond B, Haas J, Hagopian S, Hagopian V, Johnson KF, Khatiwada A, Prosper H, Weinberg M, Baarmand MM, Bhopatkar V, Colafranceschi S, Hohlmann M, Kalakhety H, Noonan D, Roy T, Yumiceva F, Adams MR, Apanasevich L, Berry D, Betts RR, Bucinskaite I, Cavanaugh R, Evdokimov O, Gauthier L, Gerber CE, Hofman DJ, Kurt P, O’Brien C, Sandoval Gonzalez LD, Silkworth C, Turner P, Varelas N, Wu Z, Zakaria M, Bilki B, Clarida W, Dilsiz K, Durgut S, Gandrajula RP, Haytmyradov M, Khristenko V, Merlo JP, Mermerkaya H, Mestvirishvili A, Moeller A, Nachtman J, Ogul H, Onel Y, Ozok F, Penzo A, Snyder C, Tiras E, Wetzel J, Yi K, Anderson I, Anderson I, Barnett BA, Blumenfeld B, Eminizer N, Fehling D, Feng L, Gritsan AV, Maksimovic P, Martin C, Osherson M, Roskes J, Sady A, Sarica U, Swartz M, Xiao M, Xin Y, You C, Xiao M, Baringer P, Bean A, Benelli G, Bruner C, Kenny RP, Majumder D, Majumder D, Malek M, Murray M, Sanders S, Stringer R, Wang Q, Ivanov A, Kaadze K, Khalil S, Makouski M, Maravin Y, Mohammadi A, Saini LK, Skhirtladze N, Toda S, Lange D, Rebassoo F, Wright D, Anelli C, Baden A, Baron O, Belloni A, Calvert B, Eno SC, Ferraioli C, Gomez JA, Hadley NJ, Jabeen S, Jabeen S, Kellogg RG, Kolberg T, Kunkle J, Lu Y, Mignerey AC, Shin YH, Skuja A, Tonjes MB, Tonwar SC, Apyan A, Barbieri R, Baty A, Bierwagen K, Brandt S, Bierwagen K, Busza W, Cali IA, Demiragli Z, Di Matteo L, Gomez Ceballos G, Goncharov M, Gulhan D, Iiyama Y, Innocenti GM, Klute M, Kovalskyi D, Lai YS, Lee YJ, Levin A, Luckey PD, Marini AC, Mcginn C, Mironov C, Narayanan S, Niu X, Paus C, Ralph D, Roland C, Roland G, Salfeld-Nebgen J, Stephans GSF, Sumorok K, Varma M, Velicanu D, Veverka J, Wang J, Wang TW, Wyslouch B, Yang M, Zhukova V, Dahmes B, Evans A, Finkel A, Gude A, Hansen P, Kalafut S, Kao SC, Klapoetke K, Kubota Y, Lesko Z, Mans J, Nourbakhsh S, Ruckstuhl N, Rusack R, Tambe N, Turkewitz J, Acosta JG, Oliveros S, Avdeeva E, Bloom K, Bose S, Claes DR, Dominguez A, Fangmeier C, Gonzalez Suarez R, Kamalieddin R, Keller J, Knowlton D, Kravchenko I, Meier F, Monroy J, Ratnikov F, Siado JE, Snow GR, Alyari M, Dolen J, George J, Godshalk A, Harrington C, Iashvili I, Kaisen J, Kharchilava A, Kumar A, Rappoccio S, Roozbahani B, Alverson G, Barberis E, Baumgartel D, Chasco M, Hortiangtham A, Massironi A, Morse DM, Nash D, Orimoto T, Teixeira De Lima R, Trocino D, Wang RJ, Wood D, Zhang J, Hahn KA, Kubik A, Mucia N, Odell N, Pollack B, Pozdnyakov A, Schmitt M, Stoynev S, Sung K, Trovato M, Velasco M, Brinkerhoff A, Dev N, Hildreth M, Jessop C, Karmgard DJ, Kellams N, Lannon K, Marinelli N, Meng F, Mueller C, Musienko Y, Planer M, Reinsvold A, Ruchti R, Smith G, Taroni S, Valls N, Wayne M, Wolf M, Woodard A, Antonelli L, Brinson J, Bylsma B, Durkin LS, Flowers S, Hart A, Hill C, Hughes R, Ji W, Ling TY, Liu B, Luo W, Puigh D, Rodenburg M, Winer BL, Wulsin HW, Driga O, Elmer P, Hardenbrook J, Hebda P, Koay SA, Lujan P, Marlow D, Medvedeva T, Mooney M, Olsen J, Palmer C, Piroué P, Saka H, Stickland D, Tully C, Zuranski A, Malik S, Barnes VE, Benedetti D, Bortoletto D, Gutay L, Jha MK, Jones M, Jung K, Miller DH, Neumeister N, Primavera F, Radburn-Smith BC, Shi X, Shipsey I, Silvers D, Sun J, Svyatkovskiy A, Wang F, Xie W, Xu L, Parashar N, Stupak J, Adair A, Akgun B, Chen Z, Ecklund KM, Geurts FJM, Guilbaud M, Li W, Michlin B, Northup M, Padley BP, Redjimi R, Roberts J, Rorie J, Tu Z, Zabel J, Betchart B, Bodek A, de Barbaro P, Demina R, Eshaq Y, Ferbel T, Galanti M, Galanti M, Garcia-Bellido A, Han J, Harel A, Hindrichs O, Hindrichs O, Khukhunaishvili A, Petrillo G, Tan P, Verzetti M, Arora S, Barker A, Chou JP, Contreras-Campana C, Contreras-Campana E, Ferencek D, Gershtein Y, Gray R, Halkiadakis E, Hidas D, Hughes E, Kaplan S, Kunnawalkam Elayavalli R, Lath A, Nash K, Panwalkar S, Park M, Salur S, Schnetzer S, Sheffield D, Somalwar S, Stone R, Thomas S, Thomassen P, Walker M, Foerster M, Riley G, Rose K, Spanier S, York A, Bouhali O, Castaneda Hernandez A, Celik A, Dalchenko M, De Mattia M, Delgado A, Dildick S, Dildick S, Eusebi R, Gilmore J, Huang T, Kamon T, Krutelyov V, Krutelyov V, Mueller R, Osipenkov I, Pakhotin Y, Patel R, Patel R, Perloff A, Rose A, Safonov A, Tatarinov A, Ulmer KA, Akchurin N, Cowden C, Damgov J, Dragoiu C, Dudero PR, Faulkner J, Kunori S, Lamichhane K, Lee SW, Libeiro T, Undleeb S, Volobouev I, Appelt E, Delannoy AG, Greene S, Gurrola A, Janjam R, Johns W, Maguire C, Mao Y, Melo A, Ni H, Sheldon P, Snook B, Tuo S, Velkovska J, Xu Q, Arenton MW, Cox B, Francis B, Goodell J, Hirosky R, Ledovskoy A, Li H, Lin C, Neu C, Sinthuprasith T, Sun X, Wang Y, Wolfe E, Wood J, Xia F, Clarke C, Harr R, Karchin PE, Kottachchi Kankanamge Don C, Lamichhane P, Sturdy J, Belknap DA, Carlsmith D, Cepeda M, Dasu S, Dodd L, Duric S, Gomber B, Grothe M, Hall-Wilton R, Herndon M, Hervé A, Klabbers P, Lanaro A, Levine A, Long K, Loveless R, Mohapatra A, Ojalvo I, Perry T, Pierro GA, Polese G, Ruggles T, Sarangi T, Savin A, Sharma A, Smith N, Smith WH, Taylor D, Woods N. Event generator tunes obtained from underlying event and multiparton scattering measurements

New sets of parameters ("tunes") for the underlying-event (UE) modelling of the pythia8, pythia6 and herwig++ Monte Carlo event generators are constructed using different parton distribution functions. Combined fits to CMS UE proton-proton ([Formula: see text]) data at [Formula: see text] and to UE proton-antiproton ([Formula: see text]) data from the CDF experiment at lower [Formula: see text], are used to study the UE models and constrain their parameters, providing thereby improved predictions for proton-proton collisions at 13[Formula: see text]. In addition, it is investigated whether the values of the parameters obtained from fits to UE observables are consistent with the values determined from fitting observables sensitive to double-parton scattering processes. Finally, comparisons are presented of the UE tunes to "minimum bias" (MB) events, multijet, and Drell-Yan ([Formula: see text] lepton-antilepton+jets) observables at 7 and 8[Formula: see text], as well as predictions for MB and UE observables at 13[Formula: see text].

The von Hippel-Lindau tumor suppressor protein regulates gene expression and tumor growth through histone demethylase JARID1C

In clear-cell renal cell carcinoma (ccRCC), inactivation of the tumor suppressor von Hippel-Lindau (VHL) occurs in the majority of the tumors and is causal for the pathogenesis of ccRCC. Recently, a large-scale genomic sequencing study of ccRCC tumors revealed that enzymes that regulate histone H3 lysine 4 trimethylation (H3K4Me3), such as JARID1C/KDM5C/SMCX and MLL2, were mutated in ccRCC tumors, suggesting that H3K4Me3 might have an important role in regulating gene expression and tumorigenesis. In this study we report that in VHL-deficient ccRCC cells, the overall H3K4Me3 levels were significantly lower than that of VHL+/+ counterparts. Furthermore, this was hypoxia-inducible factor (HIF) dependent, as depletion of HIF subunits by small hairpin RNA in VHL-deficient ccRCC cells restored H3K4Me3 levels. In addition, we demonstrated that only loss of JARID1C, not JARID1A or JARID1B, abolished the difference of H3K4Me3 levels between VHL-/- and VHL+/+ cells, and JARID1C displayed HIF-dependent expression pattern. JARID1C in VHL-/- cells was responsible for the suppression of HIF-responsive genes insulin-like growth factor-binding protein 3 (IGFBP3), DNAJC12, COL6A1, growth and differentiation factor 15 (GDF15) and density-enhanced phosphatase 1. Consistent with these findings, the H3K4Me3 levels at the promoters of IGFBP3, DNAJC12, COL6A1 and GDF15 were lower in VHL-/- cells than in VHL+/+ cells, and the differences disappeared after JARID1C depletion. Although HIF2α is an oncogene in ccRCC, some of its targets might have tumor suppressive activity. Consistent with this, knockdown of JARID1C in 786-O VHL-/- ccRCC cells significantly enhanced tumor growth in a xenograft model, suggesting that JARID1C is tumor suppressive and its mutations are tumor promoting in ccRCC. Thus, VHL inactivation decreases H3K4Me3 levels through JARID1C, which alters gene expression and suppresses tumor growth.

NaCl regulation of plasma membrane H(+)-ATPase gene expression in a glycophyte and a halophyte

NaCl regulation of plasma membrane H(+)-ATPase gene expression in the glycophyte tobacco (Nicotiana tabacum L. var Wisconsin 38) and the halophyte Atriplex nummularia L. was evaluated by comparison of organ-specific mRNA abundance using homologous cDNA probes encoding the ATPases of the respective plants. Accumulation of mRNA was induced by NaCl in fully expanded leaves and in roots but not in expanding leaves or stems. The NaCl responsiveness of the halophyte to accumulate plasma membrane H(+)-ATPase mRNA in roots was substantially greater than that of the glycophyte. Salt-induced transcript accumulation in A. nummularia roots was localized by in situ hybridization predominantly to the elongation zone, but mRNA levels also increased in the zone of differentiation. Increased message accumulation in A. nummularia roots could be detected within 8 h after NaCl (400 mM) treatment, and maximal levels were severalfold greater than in roots of untreated control plants. NaCl-induced plasma membrane H(+)-ATPase gene expression in expanded leaves and roots presumably indicates that these organs require increased H(+)-electrochemical potential gradients for the maintenance of plant ion homeostasis for salt adaptation. The greater capacity of the halophyte to induce plasma membrane H(+)-ATPase gene expression in response to NaCl may be a salt-tolerance determinant.

Extraction and validation of a new set of CMS pythia8 tunes from underlying-event measurements

New sets of CMS underlying-event parameters ("tunes") are presented for the pythia8 event generator. These tunes use the NNPDF3.1 parton distribution functions (PDFs) at leading (LO), next-to-leading (NLO), or next-to-next-to-leading (NNLO) orders in perturbative quantum chromodynamics, and the strong coupling evolution at LO or NLO. Measurements of charged-particle multiplicity and transverse momentum densities at various hadron collision energies are fit simultaneously to determine the parameters of the tunes. Comparisons of the predictions of the new tunes are provided for observables sensitive to the event shapes at LEP, global underlying event, soft multiparton interactions, and double-parton scattering contributions. In addition, comparisons are made for observables measured in various specific processes, such as multijet, Drell-Yan, and top quark-antiquark pair production including jet substructure observables. The simulation of the underlying event provided by the new tunes is interfaced to a higher-order matrix-element calculation. For the first time, predictions from pythia8 obtained with tunes based on NLO or NNLO PDFs are shown to reliably describe minimum-bias and underlying-event data with a similar level of agreement to predictions from tunes using LO PDF sets.

Coexistence of oxidized lipids and alpha-tocopherol in all lipoprotein density fractions isolated from advanced human atherosclerotic plaques

After investigation of the contents and redox status of antioxidants and lipids in homogenates of both normal artery and atherosclerotic plaque, we now investigated them in the density fractions (very low, low, high, and protein fractions) of atherosclerotic plaque freshly obtained from carotid endarterectomy. By using the optimum extraction method (homogenization in carbonate buffer) and after density gradient ultracentrifugation, we isolated and characterized density fractions of plaque for apolipoproteins, size and contents of alpha-tocopherol (alpha-TOH), unesterified cholesterol, cholesteryl linoleate (Ch18:2), and hydroxides and hydroperoxides of Ch18:2, ie, Ch18:2-O(O)H. The distribution of apolipoproteins was more heterogeneous than that in the corresponding lipoproteins isolated from blood, and the majority of material in all plaque density fractions was present in large particles eluting in the void volume of gel-filtration columns. The content of unesterified cholesterol per unit of protein in low- and high-density fractions was 10-fold that in corresponding plasma lipoproteins. Low- and very-low-density fractions contained most of the lesion lipids and alpha-TOH. Two to five percent of lesion Ch18:2 was present as Ch18:2-O(O)H and distributed more or less equally among all density fractions, yet the content of alpha-TOH per unit of Ch18:2 was higher than that in corresponding plasma lipoproteins. These results demonstrate that alpha-TOH and oxidized lipids coexist in all lesion density fractions, further supporting the notion that large proportions of lipids in lipoproteins of advanced stages of atherosclerosis are oxidized. However, although not ruling it out, our results do not support the suggestion that advanced stages of atherosclerosis are associated with gross deficiencies in the lipoproteins' vitamin E content.

A stable droplet reactor for high temperature nanocrystal synthesis

We report a versatile capillary-based droplet reactor for the controlled synthesis of nanoparticles over a wide range of flow conditions and temperatures. The reactor tolerates large flow-rate differentials between individual reagent streams, and allows droplet composition to be varied independently of residence time and volume. The reactor was successfully applied to the synthesis of metal (Ag), metal-oxide (TiO(2)) and compound semiconductor (CdSe) nanoparticles, and in each case exhibited stable droplet flow over many hours of operation without fouling, even for reactions involving solid intermediates. For CdSe formed by the reaction of Cd oleate and Se, highly controlled growth could be achieved at temperatures of up to 250 °C, with emission spectra varying smoothly and reproducibly with temperature and flow-rate. The droplet reactor showed exceptional stability when operated under constant flow-rate and temperature conditions, yielding particles with well-defined band-edge emission spectra that did not vary over the course of a full day's continuous operation.

Autophagy inhibition induces enhanced proapoptotic effects of ZD6474 in glioblastoma

BACKGROUND

Autophagy is a lysosomal degradation pathway that can provide energy through its recycling mechanism to act as a cytoprotective adaptive response mediating treatment resistance in cancer cells. We investigated the autophagy-inducing effects of ZD6474, a small-molecule inhibitor that blocks activities of vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR), and RET tyrosine kinases.

METHODS

We investigated the effects of ZD6474 on autophagy in glioblastomas cells. The ZD6474 mechanism of action was determined by western blot. We then examined the impacts of the inhibition of autophagy in combination with ZD6474 on cell apoptosis in vitro. Furthermore, we evaluated the synergistic anticancer activity of combination treatment with an autophagy inhibitor (chloroquine) and ZD6474 in U251 glioblastoma cells xenograft model.

RESULTS

ZD6474-induced autophagy was dependent on signalling through the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway. ZD6474-induced autophagy was inhibited by both knockdown of the ATG7 and Beclin 1 gene, essential autophagy genes, and pharmacologic agents (chloroquine and 3-methyalanine) treatment. Both treatments also dramatically sensitised glioblastoma cells to ZD6474-induced apoptosis, decreasing cell viability in vitro. Furthermore, in a xenograft mouse model, combined treatment with ZD6474 and chloroquine significantly inhibited U251 tumour growth, and increased the numbers of apoptotic cells compared with treatment with either agent alone.

CONCLUSION

Autophagy protects glioblastoma cells from the proapoptotic effects of ZD6474, which might contribute to tumour resistance against ZD6474 treatment.

Two wound-inducible soybean cysteine proteinase inhibitors have greater insect digestive proteinase inhibitory activities than a constitutive homolog

Diverse functions for three soybean (Glycine max L. Merr.) cysteine proteinase inhibitors (CysPIs) are inferred from unique characteristics of differential regulation of gene expression and inhibitory activities against specific Cys proteinases. Based on northern blot analyses, we found that the expression in leaves of one soybean CysPI gene (L1) was constitutive and the other two (N2 and R1) were induced by wounding or methyl jasmonate treatment. Induction of N2 and R1 transcript levels in leaves occurred coincidentally with increased papain inhibitory activity. Analyses of kinetic data from bacterial recombinant CysPI proteins indicated that soybean CysPIs are noncompetitive inhibitors of papain. The inhibition constants against papain of the CysPIs encoded by the wound and methyl jasmonate-inducible genes (57 and 21 nM for N2 and R1, respectively) were 500 to 1000 times lower than the inhibition constant of L1 (19,000 nM). N2 and R1 had substantially greater inhibitory activities than L1 against gut cysteine proteinases of the third-instar larvae of western corn rootworm and Colorado potato beetle. Cysteine proteinases were the predominant digestive proteolytic enzymes in the guts of these insects at this developmental stage. N2 and R1 were more inhibitory than the epoxide trans-epoxysuccinyl-L-leucylamide-(4-guanidino)butane (E-64) against western corn rootworm gut proteinases (50% inhibition concentration = 50, 200, and 7000 nM for N2, R1, and E-64, respectively). However, N2 and R1 were less effective than E-64 against the gut proteinases of Colorado potato beetle. These results indicate that the wound-inducible soybean CysPIs, N2 and R1, function in host plant defense against insect predation, and that substantial variation in CysPI activity against insect digestive proteinases exists among plant CysPI proteins.

Evaluation of paeonol-loaded transethosomes as transdermal delivery carriers

Paeonol shows effective anti-allergic, anti-inflammatory and analgesic activities. However, because of its poor solubility in water and high volatility at room temperature, the application of this drug is restricted in the clinic. The objective of this research was to develop a biocompatible paeonol formulation with improved stability, skin delivery and pharmacokinetic efficiency. In this paper, paeonol-loaded vesicles were prepared using an ethanol injection method. Nano-vesicles were characterized for their physical properties and encapsulation efficiency (EE). Drug permeation behavior in vitro and deposition quantity in porcine ear skin were measured with a Valia-Chien (V-C) diffusion device. Additionally, a validated and sensitive high performance liquid chromatography (HPLC) method was developed to analyze paeonol concentrations in rat plasma after transdermal administration. The results showed that the particle-size order of the nano-vesicles was the following: transethosomes (122.5±7.5nm)<transfersomes (256.5±8.9nm). Compared to the paeonol transfersomes, the transethosomes had a higher EE (85.5±5.2%), and they showed a spherical morphology with a smooth surface when viewed under a transmission electron microscope (TEM). In an in vitro permeation study, the paeonol transethosomes showed an enhanced transdermal flux of 95.7±8.8μg/cm²/h and a higher deposition quantity in porcine ear skin compared to the transfersomes. A one-compartment first-order absorption model could be used to describe the pharmacokinetics of paeonol in rats after transdermal administration. The AUC of the paeonol transethosomes was approximately 1.57- and 3.52-fold higher than those of the transfersomes and a saturated solution of paeonol in 35% ethanol, respectively. The results demonstrated that the paeonol transethosomes had a narrow size distribution, high encapsulation efficiency, and long residence in the plasma. This formulation remarkably enhanced the bioavailability of paeonol.

DNA binding specificity of the wheat bZIP protein EmBP-1

EmBP-1 is a wheat DNA binding protein of the basic leucine zipper (bZIP) class of transcription factors implicated in the mechanisms of abscisic acid mediated gene activation. Understanding the role of EmBP-1 in regulating gene transcription requires elucidation of its DNA binding specificity. The binding of EmBP-1 was studied using gel shift selection of DNA from random sequence pools. DNA binding sites were identified by sequencing of a selected pool and by cloning and sequencing individual sites. The binding sites were compared by mobility shift assay and DNase I footprinting, which show that EmBP-1 binds to a family of sequences with varying degrees of affinity. The highest affinity site bound by EmBP-1 is the palindrome GCCACGTGGC. EmBP-1 also binds several other sequences with high affinity, however most of these are asymmetric. While nearly all sequences bound by EmBP-1 contain an ACGT core sequence, EmBP-1 can also bind at least two sites with altered cores. These results provide a basis for comparing the DNA binding specificity of EmBP-1 with those of other plant bZIP proteins and provide insight into the possible target sites which EmBP-1 might bind in vivo.

Morin hydrate attenuates Staphylococcus aureus virulence by inhibiting the self-assembly of α-hemolysin

AIMS

To investigate the mechanism by which morin hydrate inhibits the haemolytic activity of α-hemolysin (Hla), a channel-forming toxin that is important for the pathogenesis of disease in experimental animals, and its therapeutic effect against Staphylococcus aureus pneumonia in a mouse model.

METHODS AND RESULTS

The results from the in vitro (haemolysis, western blot and cytotoxicity assays) and in vivo (mouse model of intranasal lung infection) experiments indicated that morin hydrate, a natural compound with little anti-Staph. aureus activity, could effectively antagonize the cytolytic activity of Hla, alleviate human lung cell injury, and protect against mortality of Staph. aureus pneumonia in a mouse model of infection. Molecular dynamics simulations, free energy calculations and mutagenesis assays were further employed to determine the catalytic mechanism of inhibition, which indicated that a direct binding of morin to the 'Stem' domain of Hla (residues I107 and T109) and the concomitant change in conformation led to the inhibition of the self-assembly of the heptameric transmembrane pore, thus inhibiting the biological activity of Hla for cell lysis.

CONCLUSIONS

Morin inhibited Staph. aureus virulence via inhibiting the haemolytic activity of α-hemolysin.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings suggested that morin is a promising candidate for the development of anti-virulence therapeutic agents for the treatment of Staph. aureus infections.

Real-time microfluidic recombinase polymerase amplification for the toxin B gene of Clostridium difficile on a SlipChip platform

Clostridium difficile is one of the key bacterial pathogens that cause infectious diarrhoea both in the developed and developing world. Isothermal nucleic acid amplification methods are increasingly used for identification of toxinogenic infection by clinical labs. For this purpose, we developed a low-cost microfluidic platform based on the SlipChip concept and implemented real-time isothermal recombinase polymerase amplification (RPA). The on-chip RPA assay targets the Clostridium difficile toxin B gene (tcdB) coding for toxin B, one of the proteins responsible for bacterial toxicity. The device was fabricated in clear acrylic using rapid prototyping methods. It has six replicate 500 nL reaction wells as well as two sets of 500 nL control wells. The reaction can be monitored in real-time using exonuclease fluorescent probes with an initial sample volume of as little as 6.4 μL. We demonstrated a limit of detection of 1000 DNA copies, corresponding to 1 fg, at a time-to-result of <20 minutes. This miniaturised platform for pathogen detection has potential for use in resource-limited environments or at the point-of-care because of its ease of use and low cost, particularly if combined with preserved reagents.

Light Induced Defect Creation Kinetics in Thin Film Protocrystalline Silicon Materials and Their Solar Cells

Using real time spectroscopic ellipsometry to characterize the microstructure and evolutionary growth of Si:H materials deposited with and without hydrogen dilution, phase diagrams were developed which clearly defined and established growth in the protocrystalline regime. Guided by these phase diagrams thin films and intrinsic layers in p-i-n cell structures were grown which consist solely of the protocrystalline phase so that the bulk uniform properties of the material could be characterized with confidence. Studies were carried out on the light induced changes in these films and cell structures that include the annealing out of defects as well as their creation under 1 sun illumination at temperatures from 25°C to 100°C that include the attainment of a degraded steady states (DSS). Defect states were characterized in films with electron mobility lifetimes (μτ), and subgap absorption at 1.2eV (α(1.2)); and in the i material of the p-i-n cells by the bulk limited fill factor (FF). The contributions of the different gap states to SWE are identified and characterized. The absence of direct correlations between α(1.2) with μτ and FF present in undiluted and diluted materials also found in protocrystalline Si:H. Similarities, on the other hand, are found between the μτ products and the FFs including the striking changes in the kinetics that occur at ∼40°C. Direct correlations between the changes in μτ and FF at different temperatures are presented. The reason for this correlation and lack of it for α(1.2) are briefly discussed with direct correlation of the α(1.2) to cell characteristics being presented, be it not with the FF.

Characterization of expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in prostate cancer cell lines

Stromal expression of some matrix metalloproteinases (MMPs) has been associated with increasing tumour burden in prostate cancer. We investigated the expression of mRNA (by RT-PCR) and protein (by zymography and western blotting) of MMPs and endogenous inhibitors (tissue inhibitors of metalloproteinases, TIMPs) in two parent epithelial prostate cancer cell lines and sublines of increasing invasive/metastatic potential. Expression of membrane type MMPs, MT1-MMP and MT3-MMP mRNA was higher in PC3-derived than in LNCaP-derived lines, whereas MT2-MMP mRNA expression was higher in the LNCaPderived than in PC3-derived cell lines. Active MT1, MT2 and MT3-MMP protein levels were similar in all lines, but processed MT-MMPs, indicative of latent MMP activation, were increased in more aggressive sublines. Expression of MMP-1, MMP-13 and TIMP-1 was higher in the more aggressive sublines and may be implicated in invasive/metastatic ability. Regulation of MMP-1 and MMP-13 expression may offer important therapeutic options for treating patients with prostate cancer.