Ras-dependent induction of cellular responses by constitutively active phosphatidylinositol-3 kinase

Phosphatidylinositol (Pl)-3 kinase is one of many enzymes stimulated by growth factors. A constitutively activated mutant, p110, that functions independently of growth factor stimulation was constructed to determine the specific responses regulated by Pl-3 kinase. The p110 protein exhibited high specific activity as a Pl-3 kinase and as a protein kinase. Expression of p110 in NIH 3T3 cells induced transcription from the fos promoter. Co-expression of dominant negative Ras blocked this response. When expressed in Xenopus laevis oocytes, p110 increased the amount of guanosine 5'-triphosphate-bound Ras, caused activation of the Ras effector Raf-1, and induced Ras-dependent oocyte maturation. These findings show that Pl-3 kinase can stimulate diverse Ras-dependent cellular processes, including oocyte maturation and fos transcription.

Amelioration of lupus-like autoimmune disease in NZB/WF1 mice after treatment with a blocking monoclonal antibody specific for complement component C5

New Zealand black x New Zealand white (NZB/W) F1 mice spontaneously develop an autoimmune syndrome with notable similarities to human systemic lupus erythematosus. Female NZB/WF1 mice produce high titers of antinuclear antibodies and invariably succumb to severe glomerulonephritis by 12 months of age. Although the development of the immune-complex nephritis is accompanied by abundant local and systemic complement activation, the role of proinflammatory complement components in disease progression has not been established. In this study we have examined the contribution of activated terminal complement proteins to the pathogenesis of the lupus-like autoimmune disease. Female NZB/W F1 mice were treated with a monoclonal antibody (mAb) specific for the C5 component of complement that blocks the cleavage of C5 and thus prevents the generation of the potent proinflammatory factors C5a and C5b-9. Continuous therapy with anti-C5 mAb for 6 months resulted in significant amelioration of the course of glomerulonephritis and in markedly increased survival. These findings demonstrate an important role for the terminal complement cascade in the progression of renal disease in NZB/W F1 mice, and suggest that mAb-mediated C5 inhibition may be a useful approach to the therapy of immune-complex glomerulonephritis in humans.

Alfvénic velocity spikes and rotational flows in the near-Sun solar wind

The prediction of a supersonic solar wind¹ was first confirmed by spacecraft near Earth^2,3 and later by spacecraft at heliocentric distances as small as 62 solar radii⁴. These missions showed that plasma accelerates as it emerges from the corona, aided by unidentified processes that transport energy outwards from the Sun before depositing it in the wind. Alfvénic fluctuations are a promising candidate for such a process because they are seen in the corona and solar wind and contain considerable energy^5-7. Magnetic tension forces the corona to co-rotate with the Sun, but any residual rotation far from the Sun reported until now has been much smaller than the amplitude of waves and deflections from interacting wind streams⁸. Here we report observations of solar-wind plasma at heliocentric distances of about 35 solar radii^9-11, well within the distance at which stream interactions become important. We find that Alfvén waves organize into structured velocity spikes with duration of up to minutes, which are associated with propagating S-like bends in the magnetic-field lines. We detect an increasing rotational component to the flow velocity of the solar wind around the Sun, peaking at 35 to 50 kilometres per second-considerably above the amplitude of the waves. These flows exceed classical velocity predictions of a few kilometres per second, challenging models of circulation in the corona and calling into question our understanding of how stars lose angular momentum and spin down as they age^12-14.

A flat inclined modular photobioreactor for outdoor mass cultivation of photoautotrophs

A flat inclined modular photobioreactor (FIMP) for mass cultivation of photoautotrophic microorganisms is described. It consists of flat glass reactors connected in cascade facing the sun with the proper tilt angles to assure maximal exposure to direct beam radiation. The optimal cell density in reference to the length of the reactor light path was evaluated, and the effect of the tilt angle on utilization of both direct beam as well as diffuse sunlight was quantitatively assessed. The mixing mode and extent were also optimized in reference to productivity of biomass. The FIMP proved very successful in supporting continuous cultures of the tested species of photoautotrophs, addressing the major criteria involved in design optimization of photobioreactors: Made of fully transparent glass, inclined toward the sun and endowed with a high surface-to-volume ratio, it combines an optimal light path with a vigorous agitation system. The maximal exposure to the culture to solar irradiance as well as the substantial control of temperature facilitate, under these conditions, a particularly high, extremely light-limited optimal cell density. The integrated effects of these growth conditions resulted in record volumetric and areal output rates of Monodus subterraneus, Anabana siamensis, and Spirulina platensis. (c) 1996 John Wiley & Sons, Inc.

Long-term T cell memory requires the surface expression of self-peptide/major histocompatibility complex molecules

How memory T cells are maintained in vivo is poorly understood. To address this problem, a male-specific peptide (H-Y) was identified and used to activate female anti-H-Y T cells in vitro. Anti-H-Y T cells survived in vivo for at least 70 days in the absence of antigen. This persistence was not because of the intrinsic ability of memory T cells to survive in vivo. Instead, the survival and function of adoptively transferred memory cells was found to require transporter of antigen protein 1-dependent expression of self-peptide/major histocompatibility complex class I molecules in recipient animals. Therefore, it appears that the level of T cell receptor engagement provided by transporter of antigen protein 1-dependent, self-peptide/major histocompatibility complexes is sufficient to maintain the long-term survival and functional phenotype of memory cells in the absence of persistent antigen. These data suggest that positive selection plays a role not only in T cell development but also in the maintenance of T cell memory.

Acetylcholine stimulates cortical precursor cell proliferation in vitro via muscarinic receptor activation and MAP kinase phosphorylation

Increasing evidence has shown that some neurotransmitters act as growth-regulatory signals during brain development. Here we report a role for the classical neurotransmitter acetylcholine (ACh) to stimulate proliferation of neural stem cells and stem cell-derived progenitor cells during neural cell lineage progression in vitro. Neuroepithelial cells in the ventricular zone of the embryonic rat cortex were found to express the m2 subtype of the muscarinic receptor. Neural precursor cells dissociated from the embryonic rat cortical neuroepithelium were expanded in culture with basic fibroblast growth factor (bFGF). reverse transcriptase-polymerase chain reaction (RT-PCR) revealed the presence of m2, m3 and m4 muscarinic receptor subtype transcripts, while immunocytochemistry demonstrated m2 protein. ACh and carbachol induced an increase in cytosolic Ca2+ and membrane currents in proliferating (BrdU+) cells, both of which were abolished by atropine. Exposure of bFGF-deprived precursor cells to muscarinic agonists not only increased both cell number and DNA synthesis, but also enhanced differentiation of neurons. These effects were blocked by atropine, indicating the involvement of muscarinic ACh receptors. The growth-stimulating effects were also antagonized by a panel of inhibitors of second messengers, including 1,2-bis-(O-aminophenoxy)-ethane-N,N,N', N'-tetraacetic acid (BAPTA-AM) to chelate cytosolic Ca2+, EGTA to complex extracellular Ca2+, pertussis toxin, which uncouples certain G-proteins, the protein kinase C inhibitor H7 and the mitogen-activated protein kinase (MAPK) inhibitor PD98059. Muscarinic agonists activated MAPK, which was significantly inhibited by atropine and the same panel of inhibitors. Thus, muscarinic receptors expressed by neural precursors transduce a growth-regulatory signal during neurogenesis via pathways involving pertussis toxin-sensitive G-proteins, Ca2+ signalling, protein kinase C activation, MAPK phosphorylation and DNA synthesis.

A photosystem I reaction center driven by chlorophyll d in oxygenic photosynthesis

A far-red type of oxygenic photosynthesis was discovered in Acaryochloris marina, a recently found marine prokaryote that produces an atypical pigment chlorophyll d (Chl d). The purified photosystem I reaction center complex of A. marina contained 180 Chl d per 1 Chl a with PsaA-F, -L, -K, and two extra polypeptides. Laser excitation induced absorption changes of reaction center Chl d that was named P740 after its peak wavelength. A midpoint oxidation reduction potential of P740 was determined to be +335 mV. P740 uses light of significantly low quantum energy (740 nm = 1.68 eV) but generates a reducing power almost equivalent to that produced by a special pair of Chl a (P700) that absorbs red light at 700 nm (1.77 eV) in photosystem I of plants and cyanobacteria. The oxygenic photosynthesis based on Chl d might either be an acclimation to the far-red light environments or an evolutionary intermediate between the red-absorbing oxygenic and the far-red absorbing anoxygenic photosynthesis that uses bacteriochlorophylls.

Strong induction of activin expression after injury suggests an important role of activin in wound repair

Activins are members of the transforming growth factor beta (TGF beta) superfamily, which comprises a growing group of dimeric proteins. TGF beta and several other members of this superfamily are known to play an important role in wound healing. However, expression of activin during wound healing has not been demonstrated so far. In this study we have analyzed the expression pattern of activin and activin receptors in normal and wounded skin. We found a large induction of activin A and a minor induction of activin B mRNA expression 1 day after skin injury and high expression levels of activin A and B were found within the first 7 days after wounding. At 13 days after injury, expression of activin A mRNA had returned to the basal level, whereas high levels of activin B persisted. In situ hybridization studies revealed expression of activin A in the granulation tissue below the wound and activin B in the hyperproliferative epithelium at the wound edge and in the migrating epithelial tongue. All known types of activin receptors as well as the activin binding protein follistatin were expressed in normal and wounded skin. However, no significant induction of receptor gene expression was seen during the repair process. The distribution of activins and activin receptors in the wound suggests multiple autocrine and paracrine activities of the ligands during wound healing. Our data provide evidence for a novel function of activin and indicate that--besides TGF beta s themselves--other members of this superfamily might also play an important role in tissue repair.

Calcium signaling and oxidant stress in the vasculature

Recent evidence suggests that oxidant stress plays a major role in several aspects of vascular biology. Oxygen free radicals are implicated as important factors in signaling mechanisms leading to vascular pathologies such as postischemic reperfusion injury and atherosclerosis. The role of intracellular Ca(2+) in these signaling events is an emerging area of vascular research that is providing insights into the mechanisms mediating these complex physiological processes. This review explores sources of free radicals in the vasculature, as well as effects of free radicals on Ca(2+) signaling in vascular endothelial and smooth muscle cells. In the endothelium, superoxides enhance and peroxides attenuate agonist-stimulated Ca(2+) responses, suggesting differential signaling mechanisms depending on radical species. In smooth muscle cells, both superoxides and peroxides disrupt the sarcoplasmic reticulum Ca(2+)-ATPase, leading to both short- and long-term effects on smooth muscle Ca(2+) handling. Because vascular Ca(2+) signaling is altered by oxidant stress in ischemia-related disease states, understanding these pathways may lead to new strategies for preventing or treating arterial disease.

Panagiotopoulou E, Panagoulias I, Pandini CE, Panduro Vazquez JG, Pani P, Panitkin S, Pantea D, Paolozzi L, Papadopoulou TD, Papageorgiou K, Paramonov A, Paredes Hernandez D, Parker AJ, Parker MA, Parker KA, Parodi F, Parsons JA, Parzefall U, Pascuzzi VR, Pasqualucci E, Passaggio S, Pastore F, Pásztor G, Pataraia S, Pater JR, Pauly T, Pearce J, Pearson B, Pedersen LE, Pedersen M, Pedraza Lopez S, Pedro R, Peleganchuk SV, Penc O, Peng C, Peng H, Penwell J, Peralva BS, Perego MM, Perepelitsa DV, Perez Codina E, Perini L, Pernegger H, Perrella S, Peschke R, Peshekhonov VD, Peters K, Peters RFY, Petersen BA, Petersen TC, Petit E, Petridis A, Petridou C, Petroff P, Petrolo E, Petrov M, Petrucci F, Pettersson NE, Peyaud A, Pezoa R, Phillips PW, Piacquadio G, Pianori E, Picazio A, Piccaro E, Piccinini M, Pickering MA, Piegaia R, Pilcher JE, Pilkington AD, Pin AWJ, Pinamonti M, Pinfold JL, Pingel A, Pires S, Pirumov H, Pitt M, Plazak L, Pleier MA, Pleskot V, Plotnikova E, Pluth D, Poettgen R, Poggioli L, Pohl D, Polesello G, Poley A, Policicchio A, Polifka R, Polini A, Pollard CS, Polychronakos V, Pommès K, Pontecorvo L, Pope BG, Popeneciu GA, Poppleton A, Pospisil S, Potamianos K, Potrap IN, Potter CJ, Potter CT, Poulard G, Poveda J, Pozdnyakov V, Pozo Astigarraga ME, Pralavorio P, Pranko A, Prell S, Price D, Price LE, Primavera M, Prince S, Prokofiev K, Prokoshin F, Protopopescu S, Proudfoot J, Przybycien M, Puddu D, Purohit M, Puzo P, Qian J, Qin G, Qin Y, Quadt A, Quayle WB, Queitsch-Maitland M, Quilty D, Raddum S, Radeka V, Radescu V, Radhakrishnan SK, Radloff P, Rados P, Ragusa F, Rahal G, Raine JA, Rajagopalan S, Rammensee M, Rangel-Smith C, Ratti MG, Rauch DM, Rauscher F, Rave S, Ravenscroft T, Ravinovich I, Raymond M, Read AL, Readioff NP, Reale M, Rebuzzi DM, Redelbach A, Redlinger G, Reece R, Reed RG, Reeves K, Rehnisch L, Reichert J, Reiss A, Rembser C, Ren H, Rescigno M, Resconi S, Rezanova OL, Reznicek P, Rezvani R, Richter R, Richter S, Richter-Was E, Ricken O, Ridel M, Rieck P, Riegel CJ, Rieger J, Rifki O, Rijssenbeek M, Rimoldi A, Rimoldi M, Rinaldi L, Ristić B, Ritsch E, Riu I, Rizatdinova F, Rizvi E, Rizzi C, Robertson SH, Robichaud-Veronneau A, Robinson D, Robinson JEM, Robson A, Roda C, Rodina Y, Rodriguez Perez A, Rodriguez Rodriguez D, Roe S, Rogan CS, Røhne O, Roloff J, Romaniouk A, Romano M, Romano Saez SM, Romero Adam E, Rompotis N, Ronzani M, Roos L, Ros E, Rosati S, Rosbach K, Rose P, Rosien NA, Rossetti V, Rossi E, Rossi LP, Rosten JHN, Rosten R, Rotaru M, Roth I, Rothberg J, Rousseau D, Rozanov A, Rozen Y, Ruan X, Rubbo F, Rudolph MS, Rühr F, Ruiz-Martinez A, Rurikova Z, Rusakovich NA, Ruschke A, Russell HL, Rutherfoord JP, Ruthmann N, Ryabov YF, Rybar M, Rybkin G, Ryu S, Ryzhov A, Rzehorz GF, Saavedra AF, Sabato G, Sacerdoti S, Sadrozinski HFW, Sadykov R, Safai Tehrani F, Saha P, Sahinsoy M, Saimpert M, Saito T, Sakamoto H, Sakurai Y, Salamanna G, Salamon A, Salazar Loyola JE, Salek D, Sales De Bruin PH, Salihagic D, Salnikov A, Salt J, Salvatore D, Salvatore F, Salvucci A, Salzburger A, Sammel D, Sampsonidis D, Sánchez J, Sanchez Martinez V, Sanchez Pineda A, Sandaker H, Sandbach RL, Sandhoff M, Sandoval C, Sankey DPC, Sannino M, Sansoni A, Santoni C, Santonico R, Santos H, Santoyo Castillo I, Sapp K, Sapronov A, Saraiva JG, Sarrazin B, Sasaki O, Sato K, Sauvan E, Savage G, Savard P, Savic N, Sawyer C, Sawyer L, Saxon J, Sbarra C, Sbrizzi A, Scanlon T, Scannicchio DA, Scarcella M, Scarfone V, Schaarschmidt J, Schacht P, Schachtner BM, Schaefer D, Schaefer L, Schaefer R, Schaeffer J, Schaepe S, Schaetzel S, Schäfer U, Schaffer AC, Schaile D, Schamberger RD, Scharf V, Schegelsky VA, Scheirich D, Schernau M, Schiavi C, Schier S, Schillo C, Schioppa M, Schlenker S, Schmidt-Sommerfeld KR, Schmieden K, Schmitt C, Schmitt S, Schmitz S, Schneider B, Schnoor U, Schoeffel L, Schoening A, Schoenrock BD, Schopf E, Schott M, Schouwenberg JFP, Schovancova J, Schramm S, Schreyer M, Schuh N, Schulte A, Schultens MJ, Schultz-Coulon HC, Schulz H, Schumacher M, Schumm BA, Schune P, Schwartzman A, Schwarz TA, Schweiger H, Schwemling P, Schwienhorst R, Schwindling J, Schwindt T, Sciolla G, Scuri F, Scutti F, Searcy J, Seema P, Seidel SC, Seiden A, Seifert F, Seixas JM, Sekhniaidze G, Sekhon K, Sekula SJ, Seliverstov DM, Semprini-Cesari N, Serfon C, Serin L, Serkin L, Sessa M, Seuster R, Severini H, Sfiligoj T, Sforza F, Sfyrla A, Shabalina E, Shaikh NW, Shan LY, Shang R, Shank JT, Shapiro M, Shatalov PB, Shaw K, Shaw SM, Shcherbakova A, Shehu CY, Sherwood P, Shi L, Shimizu S, Shimmin CO, Shimojima M, Shirabe S, Shiyakova M, Shmeleva A, Shoaleh Saadi D, Shochet MJ, Shojaii S, Shope DR, Shrestha S, Shulga E, Shupe MA, Sicho P, Sickles AM, Sidebo PE, Sideras Haddad E, Sidiropoulou O, Sidorov D, Sidoti A, Siegert F, Sijacki D, Silva J, Silverstein SB, Simak V, Simic L, Simion S, Simioni E, Simmons B, Simon D, Simon M, Sinervo P, Sinev NB, Sioli M, Siragusa G, Sivoklokov SY, Sjölin J, Skinner MB, Skottowe HP, Skubic P, Slater M, Slavicek T, Slawinska M, Sliwa K, Slovak R, Smakhtin V, Smart BH, Smestad L, Smiesko J, Smirnov SY, Smirnov Y, Smirnova LN, Smirnova O, Smith JW, Smith MNK, Smith RW, Smizanska M, Smolek K, Snesarev AA, Snyder IM, Snyder S, Sobie R, Socher F, Soffer A, Soh DA, Sokhrannyi G, Solans Sanchez CA, Solar M, Soldatov EY, Soldevila U, Solodkov AA, Soloshenko A, Solovyanov OV, Solovyev V, Sommer P, Son H, Song HY, Sood A, Sopczak A, Sopko V, Sorin V, Sosa D, Sotiropoulou CL, Soualah R, Soukharev AM, South D, Sowden BC, Spagnolo S, Spalla M, Spangenberg M, Spanò F, Sperlich D, Spettel F, Spieker TM, Spighi R, Spigo G, Spiller LA, Spousta M, St. Denis RD, Stabile A, Stamen R, Stamm S, Stanecka E, Stanek RW, Stanescu C, Stanescu-Bellu M, Stanitzki MM, Stapnes S, Starchenko EA, Stark GH, Stark J, Staroba P, Starovoitov P, Stärz S, Staszewski R, Steinberg P, Stelzer B, Stelzer HJ, Stelzer-Chilton O, Stenzel H, Stewart GA, Stillings JA, Stockton MC, Stoebe M, Stoicea G, Stolte P, Stonjek S, Stradling AR, Straessner A, Stramaglia ME, Strandberg J, Strandberg S, Strandlie A, Strauss M, Strizenec P, Ströhmer R, Strom DM, Stroynowski R, Strubig A, Stucci SA, Stugu B, Styles NA, Su D, Su J, Suchek S, Sugaya Y, Suk M, Sulin VV, Sultansoy S, Sumida T, Sun S, Sun X, Sundermann JE, Suruliz K, Suster CJE, Sutton MR, Suzuki S, Svatos M, Swiatlowski M, Swift SP, Sykora I, Sykora T, Ta D, Taccini C, Tackmann K, Taenzer J, Taffard A, Tafirout R, Taiblum N, Takai H, Takashima R, Takeshita T, Takubo Y, Talby M, Talyshev AA, Tan KG, Tanaka J, Tanaka M, Tanaka R, Tanaka S, Tanioka R, Tannenwald BB, Tapia Araya S, Tapprogge S, Tarem S, Tartarelli GF, Tas P, Tasevsky M, Tashiro T, Tassi E, Tavares Delgado A, Tayalati Y, Taylor AC, Taylor GN, Taylor PTE, Taylor W, Teischinger FA, Teixeira-Dias P, Temming KK, Temple D, Ten Kate H, Teng PK, Teoh JJ, Tepel F, Terada S, Terashi K, Terron J, Terzo S, Testa M, Teuscher RJ, Theveneaux-Pelzer T, Thomas JP, Thomas-Wilsker J, Thompson PD, Thompson AS, Thomsen LA, Thomson E, Tibbetts MJ, Ticse Torres RE, Tikhomirov VO, Tikhonov YA, Timoshenko S, Tipton P, Tisserant S, Todome K, Todorov T, Todorova-Nova S, Tojo J, Tokár S, Tokushuku K, Tolley E, Tomlinson L, Tomoto M, Tompkins L, Toms K, Tong B, Tornambe P, Torrence E, Torres H, Torró Pastor E, Toth J, Touchard F, Tovey DR, Trefzger T, Tricoli A, Trigger IM, Trincaz-Duvoid S, Tripiana MF, Trischuk W, Trocmé B, Trofymov A, Troncon C, Trottier-McDonald M, Trovatelli M, Truong L, Trzebinski M, Trzupek A, Tseng JCL, Tsiareshka PV, Tsipolitis G, Tsirintanis N, Tsiskaridze S, Tsiskaridze V, Tskhadadze EG, Tsui KM, Tsukerman II, Tsulaia V, Tsuno S, Tsybychev D, Tu Y, Tudorache A, Tudorache V, Tulbure TT, Tuna AN, Tupputi SA, Turchikhin S, Turgeman D, Turk Cakir I, Turra R, Tuts PM, Ucchielli G, Ueda I, Ughetto M, Ukegawa F, Unal G, Undrus A, Unel G, Ungaro FC, Unno Y, Unverdorben C, Urban J, Urquijo P, Urrejola P, Usai G, Usui J, Vacavant L, Vacek V, Vachon B, Valderanis C, Valdes Santurio E, Valencic N, Valentinetti S, Valero A, Valery L, Valkar S, Valls Ferrer JA, Van Den Wollenberg W, Van Der Deijl PC, van der Graaf H, van Eldik N, van Gemmeren P, Van Nieuwkoop J, van Vulpen I, van Woerden MC, Vanadia M, Vandelli W, Vanguri R, Vaniachine A, Vankov P, Vardanyan G, Vari R, Varnes EW, Varol T, Varouchas D, Vartapetian A, Varvell KE, Vasquez JG, Vasquez GA, Vazeille F, Vazquez Schroeder T, Veatch J, Veeraraghavan V, Veloce LM, Veloso F, Veneziano S, Ventura A, Venturi M, Venturi N, Venturini A, Vercesi V, Verducci M, Verkerke W, Vermeulen JC, Vest A, Vetterli MC, Viazlo O, Vichou I, Vickey T, Vickey Boeriu OE, Viehhauser GHA, Viel S, Vigani L, Villa M, Villaplana Perez M, Vilucchi E, Vincter MG, Vinogradov VB, Vittori C, Vivarelli I, Vlachos S, Vlasak M, Vogel M, Vokac P, Volpi G, Volpi M, von der Schmitt H, von Toerne E, Vorobel V, Vorobev K, Vos M, Voss R, Vossebeld JH, Vranjes N, Vranjes Milosavljevic M, Vrba V, Vreeswijk M, Vuillermet R, Vukotic I, Wagner P, Wagner W, Wahlberg H, Wahrmund S, Wakabayashi J, Walder J, Walker R, Walkowiak W, Wallangen V, Wang C, Wang C, Wang F, Wang H, Wang H, Wang J, Wang J, Wang K, Wang R, Wang SM, Wang T, Wang W, Wanotayaroj C, Warburton A, Ward CP, Wardrope DR, Washbrook A, Watkins PM, Watson AT, Watson MF, Watts G, Watts S, Waugh BM, Webb S, Weber MS, Weber SW, Weber SA, Webster JS, Weidberg AR, Weinert B, Weingarten J, Weiser C, Weits H, Wells PS, Wenaus T, Wengler T, Wenig S, Wermes N, Werner MD, Werner P, Wessels M, Wetter J, Whalen K, Whallon NL, Wharton AM, White A, White MJ, White R, Whiteson D, Wickens FJ, Wiedenmann W, Wielers M, Wiglesworth C, Wiik-Fuchs LAM, Wildauer A, Wilk F, Wilkens HG, Williams HH, Williams S, Willis C, Willocq S, Wilson JA, Wingerter-Seez I, Winklmeier F, Winston OJ, Winter BT, Wittgen M, Wolf TMH, Wolff R, Wolter MW, Wolters H, Worm SD, Wosiek BK, Wotschack J, Woudstra MJ, Wozniak KW, Wu M, Wu M, Wu SL, Wu X, Wu Y, Wyatt TR, Wynne BM, Xella S, Xi Z, Xu D, Xu L, Yabsley B, Yacoob S, Yamaguchi D, Yamaguchi Y, Yamamoto A, Yamamoto S, Yamanaka T, Yamauchi K, Yamazaki Y, Yan Z, Yang H, Yang H, Yang Y, Yang Z, Yao WM, Yap YC, Yasu Y, Yatsenko E, Yau Wong KH, Ye J, Ye S, Yeletskikh I, Yildirim E, Yorita K, Yoshida R, Yoshihara K, Young C, Young CJS, Youssef S, Yu DR, Yu J, Yu JM, Yu J, Yuan L, Yuen SPY, Yusuff I, Zabinski B, Zacharis G, Zaidan R, Zaitsev AM, Zakharchuk N, Zalieckas J, Zaman A, Zambito S, Zanello L, Zanzi D, Zeitnitz C, Zeman M, Zemla A, Zeng JC, Zeng Q, Zenin O, Ženiš T, Zerwas D, Zhang D, Zhang F, Zhang G, Zhang H, Zhang J, Zhang L, Zhang L, Zhang M, Zhang R, Zhang R, Zhang X, Zhang Z, Zhao X, Zhao Y, Zhao Z, Zhemchugov A, Zhong J, Zhou B, Zhou C, Zhou L, Zhou L, Zhou M, Zhou N, Zhu CG, Zhu H, Zhu J, Zhu Y, Zhuang X, Zhukov K, Zibell A, Zieminska D, Zimine NI, Zimmermann C, Zimmermann S, Zinonos Z, Zinser M, Ziolkowski M, Živković L, Zobernig G, Zoccoli A, zur Nedden M, Zwalinski L. Performance of the ATLAS trigger system in 2015

During 2015 the ATLAS experiment recorded [Formula: see text] of proton-proton collision data at a centre-of-mass energy of [Formula: see text]. The ATLAS trigger system is a crucial component of the experiment, responsible for selecting events of interest at a recording rate of approximately 1 kHz from up to 40 MHz of collisions. This paper presents a short overview of the changes to the trigger and data acquisition systems during the first long shutdown of the LHC and shows the performance of the trigger system and its components based on the 2015 proton-proton collision data.

[Ca(2+)](i) oscillation frequency regulates agonist-stimulated NF-kappaB transcriptional activity

In nonexcitable cells, stimulation by high agonist concentrations typically produces a biphasic increase in cytosolic Ca(2+) ([Ca(2+)](i)). This response is characterized by a transient initial increase because of intracellular Ca(2+) release followed by a sustained elevation which varies in amplitude depending on the nature of the stimulus. In contrast, low-level stimulation often evokes oscillatory changes in [Ca(2+)](i). The specific information provided by repetitive [Ca(2+)](i) spikes appears to be encoded in the frequency rather than in the amplitude of [Ca(2+)](i) oscillations. The specific, membrane-permeable inositol 1,4, 5-trisphosphate (Ins-1,4,5-P(3)) receptor blocker Xestospongin C (XeC, 2-20 microM) was used to affect [Ca(2+)](i) signaling in human aortic endothelial cells (HAEC) during an established response to low-level (1 microM) histamine stimulation. XeC produced a dose-dependent decrease in the frequency of [Ca(2+)](i) oscillations during histamine stimulation without affecting oscillation amplitude. Histamine stimulated a 14-fold increase in NF-kappaB-chloramphenicol acetyltransferase reporter gene activity that was dose-dependently decreased by XeC. Thus, during low-level agonist stimulation, [Ca(2+)](i) oscillation frequency regulates nuclear transcription in HAEC.

cDNA cloning and chromosome mapping of the human Fe65 gene: interaction of the conserved cytoplasmic domains of the human beta-amyloid precursor protein and its homologues with the mouse Fe65 protein

Using the yeast two hybrid system, a mouse embryo cDNA library was screened for proteins that interact with the C-terminus of the human beta-amyloid precursor protein (beta PP). A fusion protein was identified that interacts specifically with the cytoplasmic domain of beta PP and does not interact with the beta-amyloid region. The protein encoded by this partial mouse cDNA is identical to the C-terminus of the rat Fe65 protein. This mouse protein also interacts with the homologous C-terminal domains of the mouse amyloid precursor-like proteins, APLP1 and APLP2. These conserved cytoplasmic regions contain a common amino acid motif, Asn-Pro-Thr-Tyr, which has previously been shown to influence both the secretion and internalization of beta PP. Fe65 has been implicated in regulatory and cell signaling mechanisms because it contains two different motifs involved in protein binding, a WW domain (a variant of Src homology 3 domains) and a phosphotyrosine interaction domain (PID). Interestingly, the PID domain binds to the same motif present in the conserved cytoplasmic domains of the beta PP and beta PP-like proteins. RNA analyses reveal that Fe65 is predominantly expressed in brain and in the regions most affected by Alzheimer's disease (AD)-associated neuropathology. The human Fe65 mRNA was cloned from a fetal brain cDNA library. The message encodes a protein of 735 amino acids that is 95% identical to the rat Fe65 protein. The human Fe65 gene was mapped on human metaphase chromosomes to band 11p15 using fluorescence in situ hybridization.

Modular Design of Peptide- or DNA-Modified AIEgen Probes for Biosensing Applications

Fluorophore probes are widely used for bioimaging in cells, tissues, and animals as well as for monitoring of multiple biological processes in complex environments. Such imaging properties allow scientists to make direct visualizations of pathological events and cellular targets. Conventional fluorescent molecules have been developed for several decades and achieved great successes, but their emissions are often weakened or quenched at high concentrations that might suffer from the aggregation-caused quenching (ACQ) effect, which reduces the efficiencies of their applications. In contrast to the ACQ effect, aggregation-induced emission (AIE) luminogens (AIEgens) display much higher fluorescence in aggregated states and possess various advantages such as low background, long-term tracking ability, and strong resistance to photobleaching. Therefore, AIEgens are employed as unique fluorescence molecules and building blocks for biosensing applications in the fields of ions, amino acids, carbohydrates, DNAs/RNAs, peptides/proteins, cellular organelles, cancer cells, bacteria, and so on. Quite a few of the above biosensing missions are accomplished by modular peptide-modified AIEgen probes (MPAPs) or modular DNA-modified AIEgen probes (MDAPs) because of the multiple capabilities of peptide and DNA modules, including solubility, biocompatibility, and recognition. Meanwhile, both electrostatic interactions and coupling reactions could provide efficient methods to construct different MPAPs and MDAPs, finally resulting in a large variety of biosensing probes. Those probes exhibit leading features of detecting nucleic acids or proteins and imaging mass biomolecules. For example, under modular design, peptide modules possessing versatile recognition abilities enable MPAPs to detect numerous targets, such as integrin α_vβ₃, aminopeptidase N, MMP-2, MPO, H₂O₂, and so forth; MDAP could allow the imaging of mRNA in cells and tissue chips, suggesting the diagnostic functions of MDAP in clinical samples. Modular design offers a novel strategy to generate AIEgen-based probes and expedites functional biomacromolecules research. In this vein, here we review the progress on MPAPs and MDAPs in the most recent 10 years and highlight the modular design strategy as well as their advanced biosensing applications including briefly two aspects: (1) detection and (2) imaging. By the use of MPAPs/MDAPs, multiple bioanalytes can be efficiently analyzed at low concentrations and directly visualized through high-contrast and luminous imaging. Compared with MPAPs, the quantities of MDAPs are limited because of the difficult synthesis of long-length DNA strands. In future work, multifunctional of DNA sequences are needed to explore varieties of MDAPs for diverse biosensing purposes. At the end of this Account, some deficiencies and challenges are mentioned for briging more attention to accelerate the development of AIEgen-based probes.

Hydrogen peroxide induces intracellular calcium oscillations in human aortic endothelial cells

BACKGROUND

Because the vascular endothelium is exposed to oxidant stress resulting from ischemia/reperfusion and from the products of polymorphonuclear leukocytes or monocytes, studies were performed to examine the effect of hydrogen peroxide (1 micromol/L to 10 mmol/L) on endothelial Ca2+ signaling.

METHODS AND RESULTS

At low concentrations (1 to 10 micromol/L), hydrogen peroxide did not affect intracellular Ca2+ concentration in subconfluent, indo 1-loaded human aortic endothelial monolayers. At a concentration of 100 micromol/L hydrogen peroxide, intracellular free Ca2+ gradually increased from 125.3+/-6.8 to 286.3+/-19.9 nmol/L over 4.2+/-0.9 minutes before repetitive Ca2+ oscillations were observed, consisting of an initial large, transient spike of approximately 1 micromol/L followed by several spikes of decreasing amplitudes at a frequency of 0.7+/-0.1 min-1 over 12.0+/-1.1 minutes. After these oscillations, intracellular Ca2+ reached a plateau of 543.4+/-64.0 nmol/L, which was maintained above baseline levels for >5 minutes and then partially reversible on washout of hydrogen peroxide in most monolayers. Intracellular Ca2+ oscillations were typically observed when monolayers were exposed to 100 to 500 micromol/L hydrogen peroxide. Higher concentrations of hydrogen peroxide (1 and 10 mmol/L) increased intracellular Ca2+ but only rarely (2 of 6 monolayers at 1 mmol/L) or never (at 10 mmol/L) stimulated intracellular Ca2+ oscillations. Removal of Ca2+ from the buffer either before hydrogen peroxide stimulation or during an established response did not block intracellular Ca2+ oscillations in response to 100 micromol/L hydrogen peroxide, but prior depletion of an intracellular Ca2+ store with either caffeine, histamine, or thapsigargin abolished Ca2+ oscillations.

CONCLUSIONS

Hydrogen peroxide induces concentration-dependent intracellular Ca2+ oscillations in human endothelial cells, which results from release of an endoplasmic reticulum Ca2+ store. Because oxidant production appears to occur in the micromolar range in the postischemic/anoxic endothelium and is associated with impaired endothelium-dependent relaxation, the effects of micromolar concentrations of hydrogen peroxide on endothelial Ca2+ signaling described in the present study may be important in the pathogenesis of postischemic endothelial dysfunction.

Involvement of SRPK1 in cisplatin resistance related to long non-coding RNA UCA1 in human ovarian cancer cells

The therapeutic potential of cisplatin in ovarian cancer treatment is restricted by the occurrence of cellular resistance. We aimed to explore the role of SRPK1 in cisplatin resistance related to the long non-coding RNA UCA1 in ovarian cancer cell.Totally, 24 ovarian cancer tissues and 16 normal tissues were used to assess the expression of UCA1 RNA. UCA1 stable transfected SKOV3 cells were established and the ability of cell migration, invasion and cisplatin resistance was assessed. The expression of SRPK1 and apoptosis pathway proteins was then assessed to explore the mechanism. In addition, SRPK1 knockdown cell line was also established and the effects of SRPK1 on cell migration, invasion and cisplatin resistance was evaluated.Elevated expression of UCA1 RNA was identified in ovarian cancer tissues compared with normal tissues. Expression of UCA1 RNA in SKOV3 cells enhanced the cell migration, invasion and cisplatin resistance. Increased expression of SRPK1 and anti-apoptosis proteins were found in SKOV3/pcDNA-UCA1 cells. Knocking-down SRPK1 could partly rescue the effect of UCA1 expression on cell migration, invasion and cisplatin resistance in SKOV3 cells.Elevated expression of UCA1 RNA was found in ovarian cancer tissues. UCA1 can improve the cell migration, invasion and induce cisplatin resistance. SRPK1 and apoptosis pathway proteins may be involved in the effect of UCA1.

Terahertz quantum cascade lasers operating up to ∼ 200 K with optimized oscillator strength and improved injection tunneling

A new temperature performance record of 199.5 K for terahertz quantum cascade lasers is achieved by optimizing the lasing transition oscillator strength of the resonant phonon based three-well design. The optimum oscillator strength of 0.58 was found to be larger than that of the previous record (0.41) by Kumar et al. [Appl. Phys. Lett. 94, 131105 (2009)]. The choice of tunneling barrier thicknesses was determined with a simplified density matrix model, which converged towards higher tunneling coupling strengths than previously explored and nearly perfect alignment of the states across the injection and extraction barriers at the design electric field. At 8 K, the device showed a threshold current density of 1 kA/cm2, with a peak output power of ∼ 38 mW, and lasing frequency blue-shifting from 2.6 THz to 2.85 THz with increasing bias. The wavelength blue-shifted to 3.22 THz closer to the maximum operating temperature of 199.5 K, which corresponds to ∼ 1.28ħω/κB. The voltage dependence of laser frequency is related to the Stark effect of two intersubband transitions and is compared with the simulated gain spectra obtained by a Monte Carlo approach.