Le cancer est l'une des principales causes de décès dans le monde. L'angiogenèse tumorale est le processus de formation de nouveaux vaisseaux sanguins à partir de vaisseaux préexistants. Une tumeur cancéreuse peut induire l'angiogenèse afin de disposer d'apports supplémentaires en oxygène et nutriments, indispensables à la poursuite de son développement. Cette thèse consiste en l'élaboration d'un modèle mathématique multi-échelle de l'angiogenèse tumorale. Ce modèle intègre les principaux mécanismes intervenant aux échelles tissulaire et moléculaire. Couplé à un modèle de croissance tumorale, notre modèle permet d'étudier les effets de l'apport en oxygène sur la croissance tumorale. D'un point de vue mathématique, ces modèles d'angiogenèse et de croissance tumorale reposent sur des équations aux dérivées partielles de réaction-diffusion et d'advection régissant l'évolution spatio-temporelle des densités de cellules endothéliales, cellules constituant la paroi des vaisseaux sanguins, et tumorales, ainsi que celle des concentrations tissulaires en substances pro- et antiangiogéniques et en oxygène. A l'échelle moléculaire, la liaison des substances angiogéniques aux récepteurs membranaires des cellules endothéliales, mécanisme clé de la communication intercellulaire, est modélisée à l'aide de lois pharmacologiques. Ce modèle permet ainsi de reproduire in silico les principaux mécanismes de l'angiogenèse et d'analyser leur rôle dans la croissance tumorale. Il permet également de simuler l'action de différentes thérapies anti-angiogéniques, et d'étudier leur efficacité sur le développement tumoral afin d'aider à l'innovation thérapeutique / Cancer is one of the main causes of death worldwide. Angiogenesis is the formation of new blood vessels from preexisting vessels. A cancerous tumor can induce angiogenesis in order to get essential additional oxygen and nutrients supply to grow. This thesis is about the development of a multiscale mathematical model of tumor-induced angiogenesis. This model takes into account the main mechanisms that occur at the tissue level and at the molecular level during angiogenesis. Coupled with a model of tumor growth, our model enables to simulate the e_ect of oxygen supply on tumor growth. On a mathematical point of view, these models of tumor-induced angiogenesis and tumor growth are based on reaction-di_usion and advection partial di_erential equations that govern the evolution of the densities of endothelial cells, that compose blood vessel wall, and tumor cells, and that of the tissue concentrations of pro- and anti-angiogenic substances and oxygen. At the molecular level, the binding of angiogenic substances to receptors located on the membrane of endothelial cells is modeled by use of pharmacological laws. Such bindings are key mechanisms of intercellular communication. This model makes it possible to reproduce in silico the main mechanisms of angiogenesis and to analyze their action on tumor growth. It also enables to simulate the action of several antiangiogenic therapies and to study their e_cacy on tumor growth in order to help therapeutic

A manutenção do estado progenitor durante o cultivo de células mesenquimais progenitoras derivadas do tecido adiposo (MSCs-TA), caracterizado pelo potencial de diferenciação e da capacidade de autorrenovação, é atualmente um dos maiores desafios da terapia celular. Sabendo da influência da angiogênese no desenvolvimento de tecidos de origem mesenquimal, avaliamos se um ambiente pro-angiogênico mimetizado em cultura forneceria condições para manutenção de um estado progenitor durante o processo de expansão celular. Utilizando como modelo de um ambiente pró-angiogênico o cultivo no meio EGM-2, o qual é suplementado pelos fatores de crescimento EGF, FGF-2, IGF e VEGF, nós demonstramos que a presença de tais fatores pró-angiogênicos é fundamental para a manutenção do estado progenitor de MSCs-TA em cultura. Verificamos que a presença de tais fatores de crescimento possibilitaram às MSCs-TA apresentarem um alto potencial de diferenciação adipogênico e osteogênico em comparação ao meio convencional DMEM/F12 e ao meio EBM, ausente de fatores. Além disso, o cultivo na presença de fatores pró-angiogênicos aumentou o potencial clonogênico das MSCs-TA, ao mesmo tempo em que aumentou a capacidade proliferativa destas células. Dentre os fatores de crescimento, EGF e FGF-2 foram responsáveis pelos efeitos mais robustos. Ao mesmo tempo, células cultivadas nas presença destas citocinas foram capazes de manter a morfologia fibroblastóide e apresentaram alta expressão do fator de pluripotência Klf-4. Em concordância com estes achados, o transplante subcutâneo de MSCs-TA cultivadas nestas condições mostrou que aquelas mantidas em EGM-2 geram um tecido semelhante ao tecido formado pela fração estromal vascular não cultivada. Estes resultados reforçam o papel do ambiente pró-angiogênico na manutenção do estado progenitor de MSCs-TA, e que tal estado foi proporcionado pela ação dos fatores de crescimento pró-angiogênicos EGF, FGF-2, IGF e VEGF nas células em cultivo, com destaque para as citocinas EGF e FGF-2. Em conclusão, o uso do ambiente pró-angiogênico no cultivo de MSCs-TA mostrou-se como uma abordagem promissora para a manutenção do estado progenitor destas células in vitro. / The maintenance of the progenitor state in the culture of adipose tissue derived- mesenchymal progenitor cell (TA-MSCs), characterized by the differentiation potential and self-renewal capability, is currently one of the major challenges of cell therapy. The information that the angiogenesis influences the development of mesenchymal tissues, has led us to evaluate how a pro-angiogenic environment mimicked in culture would provide conditions for maintaining a progenitor state during the cell expansion process. We designe a model for a pro-angiogenic environment in which cells grown in EGM-2 supplemented with the following growth factors: EGF, FGF-2, IGF and VEGF, and demonstrated that the presence of such pro-angiogenic growth factors was crucial for maintenance of the progenitor of AT-MSCs in culture. We observed that the presence of such growth factors allowed to AT-MSCs a high potential of adipogenic and osteogenic differentiation compared to conventional DMEM/F12 medium and the EBM medium, in the absence of the factors. Furthermore, the culture in presence of pro-angiogenic growth factors increased the clonogenic potential of AT-MSCs and increased the proliferative capability of these cells. Among the growth factors, EGF and FGF-2 were responsible for most robust effects. At the same time, cells cultured in the presence of these cytokines were able to maintaining the fibroblastoid morphology and presented high expression levels of Klf-4 pluripotency factor. In agreement with these observations, the subcutaneous transplantation of AT-MSCs cultured under these conditions showed that those cells kept in EGM-2 generated a tissue-like to tissue formed by the stromal vascular fraction uncultivated. These results reinforce the role of the pro-angiogenic environment in the maintenance of the progenitor state of AT-MSCs, and that such a state was provided by the action of the pro-angiogenic growth factors EGF, FGF-2, IGF and VEGF in cultured cells, highlighting EGF and FGF-2 cytokines. In conclusion, we showed that the use of a pro-angiogenic environment in AT-MSCs culture is a promising approach to the maintain the progenitor state of these cells in vitro.

Malgré l’efficacité thérapeutique avérée des agents anti-angiogéniques et des agents anti-vasculaires (VDA), le mécanisme d’action précis des stratégies ciblant les vaisseaux sanguins tumoraux, les raisons de leur efficacité ainsi que les mécanismes de résistance à ces drogues sont encore mal compris. Il est rapidement apparu essentiel d’identifier des biomarqueurs capables de refléter l’angiogénèse tumorale ou les effets sur la vascularisation tumorale de ces traitements. Compte tenu de leur importance dans des pathologies vasculaires, les cellules endothéliales matures circulantes (CEC) et les progéniteurs endothéliaux circulants (CEP) ont d’emblée été pressenties comme des candidats intéressants pour être des biomarqueurs de réponse aux stratégies ciblant la vascularisation tumorale. Nous avons exploré l’intérêt de ces cellules en tant que biomarqueurs de l’angiogénèse dans des tumeurs pédiatriques, et leur rôle en tant que biomarqueurs de traitement par des agents anti-angiogéniques chez des sujets adultes atteints de cancer. Ces travaux ont mis en lumière l’intérêt des CEP et ont été à la source d’un travail plus « mécanistique » où nous avons étudié dans différents modèles murins le rôle des CEC et CEP dans le mécanisme d’action des agents anti-vasculaires et plus particulièrement le rôle fonctionnel des CEP dans la résistance à ces molécules. Par des stratégies d’association d’agents anti-angiogéniques aux VDA destinées à inhiber les CEP, nous montrons l’augmentation de l’activité anti-tumorale des VDA et offrons un rationnel mécanistique pour optimiser les schémas thérapeutiques actuels des traitements anti-vasculaires. Nos données apportent des arguments en faveur du rôle potentiel de ces cellules en tant que biomarqueurs de l’angiogénèse, des traitements anti-angiogéniques et de la résistance aux traitements anti-vasculaires. / Despite their therapeutic impact and clinical benefit, the mecanisms of action of anti-angiogenic agents and vascular disrupting agents (VDA), the reasons for their efficacy as well as the mechanisms underlying resistance to these drugs are not fully understood. Thus, identifying surrogate biomarkers of tumor angiogenesis and of the effects of these new therapeutic agents targeting tumor blood vessels has become a crucial objective. Because of their importance in vascular diseases, mature circulating endothelial cells (CEC) and circulating endothelial progenitor cells (CEP) were suggested to be potential candidate biomarkers of disease response and relapse to vascular targeting strategies. We investigated the role of these cells as biomarkers of tumor angiogenesis in pediatric solid tumors, as well as biomarkers of response to anti-angiogenic therapies in adult cancer patients. By revealing the particularly important role of CEP, these initial studies led to a more “mechanistic” study in which the cellular and molecular effects of a VDA were evaluated with regard to CEC and CEP in different mouse models; in particular, the “catalytic” role of CEP was explored as a mechanism of resistance to VDA. By combining anti-angiogenic agents aimed to inhibit CEP mobilized by the VDA, we demonstrate an increase in the anti-tumor activity of the VDA and offer a mechanistic rational to optimize VDA-based therapeutic strategies. Our data support the role of CEC and CEP as biomarkers of angiogenesis, of anti-angiogenic strategies and of resistance to vascular-disrupting therapies.

Hämangiosarkome, maligne endotheliale Neoplasien, werden bei den Haussäugetieren am häufigsten beim Hund beobachtet und treten bei diesem vor allem in Milz und rechtem Herzohr auf. Anhand ihrer Wachstumsmuster werden sie in kapilläre, kavernöse und solide wachsende Tumoren eingeteilt (PULLEY u. STANNARD 1990, HARRY u. PALEOLOG 2003). Die Prognose kaniner Hämangiosarkome der Milz ist schlecht, wobei in der Literatur nach Splenektomie mediane Überlebenszeiten von 19-240 Tagen angegeben werden (JOHNSON et al. 1989, OGILVIE et al. 1996, SPANGLER u. KASS 1997, WOOD et al. 1998) und auch Praktiker von sehr stark variierenden Überlebenszeiten berichten. Die Eignung verschiedener Parameter (z.B. adjuvante Chemotherapie, klinisches Staging) zur prognostischen Beurteilung wurde bereits von zahlreichen Autoren untersucht (BROWN et al. 1985, SORENMO et al. 1993, WOOD et al. 1998). Studien zum eventuellen Einfluss des Wachstumsmusters auf die Variabilität der Überlebenszeiten existieren bisher jedoch nicht. Darüber hinaus können Hämangiosarkome der Milz auch diagnostisch eine Herausforderung darstellen. Dies ist zum Einen bedingt durch die hohe Anfälligkeit der Milz gegenüber einer raschen Autolyse, zum Anderen erschwert die sehr variable Histomorphologie in einigen Fällen eine sichere Diagnosestellung. Mit dem immunhistologischen Nachweis klassischer Endothelzellmarker wie von Willebrand Faktor und CD31 kann in den meisten Fällen die Diagnose gesichert werden. Besonders bei schlecht differenzierten Hämangiosarkomen, erweisen sich die genannten Marker oftmals als z. T. unzuverlässig (VON BEUST et al. 1988, GAMLEM u. NORDSTOGA 2008). Bei rein solide wachsenden Neoplasien kann der Transkriptionsfaktor Fli-1 hilfreich bei der Diagnose sein (STEIGER et al. 2003). Pro- und anti-angiogene Faktoren steuern in einem streng regulierten, stufenweise ablaufenden Prozess die Entstehung neuer Blutgefäße aus präexistenten Gefäßen – die Angiogenese (KERBEL et al. 1998, CARMELIET et al. 1998, RAK et al. 2000, JOUSSEN et al. 2003, DISTLER et al. 2003). Diese Faktoren konnten u.a. in Neoplasien und deren versorgenden Gefäßen nachgewiesen werden (RESTUCCI et al. 2002, RESTUCCI et al. 2004). Ziel der Studie ist (I) die Untersuchung der Überlebenszeiten von Hunden mit lienalen Hämangiosarkomen unter Berücksichtigung des Wachstumsmusters und weiterer Parameter, (II) wird mittels vergleichender immunhistologischer Untersuchungen die Eignung klassischer Endothelzellmarker sowie angiogener Faktoren und deren Rezeptoren zum Nachweis neoplastischer Endothelzellen überprüft. Der Vergleich des Expressionsverhaltens der genannten Marker zwischen Hämangiosarkomen und nicht-neoplastischen Endothelzellen gibt eventuell Hinweise auf die biologische Wertigkeit der Neoplasien.

No description available.

Circulating angiogenic cells (CACs) are early predictors of cardiovascular health and are inversely proportional to related outcomes. Increased number and function of CACs is seen in healthy individuals compared with individuals with cardiovascular disease (CVD). Exercise increases CAC number and function in CVD populations, through a nitric oxide-mediated mechanism. Inactivity is a growing concern in industrialized nations; it is an independent risk factor for CVD and is linked to increased mortality. The purpose of this study was to understand the effect of reduced physical activity (rPA) on two CAC populations (CFU-Hill and CD34+) in highly active individuals. We examined the mechanisms underlying changes in CAC function as a result of rPA with maintained energy balance. The two sub-populations of CACs responded differently to rPA. CFU-Hill CACs, decreased in number and amount of intracellular nitric oxide while CD34+ cells, did not change. Gene expression analyses indicated that oxidative stress- related genes did not change in CFU-Hill cells with rPA. However, correlations between CFU-Hill cell numbers, intracellular nitric oxide, and genes that are related to nitric oxide were observed. We concluded that rPA caused the observed decrease in CFU-Hill number and intracellular nitric oxide through a decrease in nitric oxide cellular availability, not oxidative stress.

No description available.

<p>UVOD: Hipertenzivna oboljenja u trudnoći predstavljaju heterogenu grupu bolesti koja se javljaju kod 3-8% trudnica op&scaron;te populacije. Najteže forme ovih oboljenja preeklampsija, eklampsija i HELLP sindrom su vodeći uzročnici morbiditeta i mortaliteta majke i ploda u odnosu na sve druge komplikacije u trudnoći. Etiopatogeneza ovih oboljenja je jo&scaron; uvek nedovoljno razja&scaron;njena ali se smatra da placenta ima ključnu ulogu u nastanku ovih komplikacija, odnosno da placentalna insuficijencija, koja nastaje kao posledica nedovoljne adaptacije decidualnih i intramiometrijalnih delova spiralnih arterija već u prvih nekoliko nedelja trudnoće, dovodi do redukcije utero-placentalne cirkulacije i lokalne placentalne hipoksije, &scaron;to se nepovoljno održava i na majku i na plod. U cilju razja&scaron;njenja patofiziolo&scaron;kih mehanizama nastanka hipertenzivnih oboljenja u trudnoći i pronalaska dovoljno senzitivnih makera koji bi pomogli u ranom predviđanju nastanka najtežih formi ovih oboljenja, do sada su ispitivani brojni proteini koji učestvuju u procesima stvaranja i razvoja placentalne vaskularne mreže kao &scaron;to su vaskularni endotelni faktor rasta (VEGF-A), placentalni faktor rasta (PlGF) i solubilni receptor fms-like tirozin kinaza receptor (sFlt-1). CILJ: Uporediti serumske koncentracije (sFlt-1, PlGF, VEGF-A, PAPP-a, free&szlig;hCG, glukoze, ukupnog holesterola, HDL holesterola, LDL holesterola, triglicerida, apo-AI, apoB, AST, ALT, GGT, kreatinina, ureje, mokraćne kiseline, hsCRP, Na, K, Cl, P, Mg i Ca između grupe trudnica sa preeklampsijom, hroničnom i gestacijskom hipertenzijom i kontrolne grupe trudnica u prvom trimestru trudnoće između 11 i 14. nedelje gestacije. Ispitati da li se vrednosti odabranih laboratorijskih parametara (sFlt-1, VEGF-A i PLGF) kod ispitivanih trudnica statistički značajno razlikuju u odnosu na gestacijsku nedelju u trenutku porođaja, težinu i dužinu i APGAR skor bodovanja novorođenčeta. Ispitati da li se vrednosti angiogenih proteina:sFlt-1, VEGF-A, PlGF značajno razlikuju kod ispitivanih trudnica u odnosu na broj prethodnih trudnoća i starosti trudnica. MATERIJAL I METODE: Istraživanje je sprovedeno kao prospektivno analitička studija u Kliničkom centru Vojvodine, u periodu od juna 2012. do februara 2015. godine. U istraživanje je uključeno ukupno 143 trudnice starosti od 18 &ndash; 43 godine. Sve trudnice uključene u istraživanje podeljene su na dve ispitivane i jednu kontrolnu grupu. Prvu ispitivanu grupu činilo je 43 trudnice koje su po definisanim kriterijuma razvile preeklampsiju u aktuelnoj trudnoći. Drugu ispitivanu grupu činilo je 46 trudnica kojima je dijagnostikovana ili potvrđena hronična ili gestacijska hipertenzija u aktuelnoj trudnoći. Kontrolnu grupu činilo je 54 zdravih trudnica sa verifikovanim fiziolo&scaron;kim ishodom trudnoće u terminu, bez maternalnih i fetalnih komplikacija. Prilikom regrutovanja trudnica (između 11+0 i 13+6 nedelja gestacije) za uče&scaron;će u istraživanju, uzeti su anamnestički podaci o faktorima rizika za pojavu hipertenzivnih oboljenja u trudnoći, i u okviru kliničkog i aku&scaron;erskog pregleda urađena su antropometrijska merenja, merenje krvnog pritiska, i specijalizovani ultrazvučni pregled ploda radi utvrđivanja gestacijske starosti ploda i određivanja rizika za pojavu hromozomskih anomalija ploda. Trudnicama je nakon uzimanja anamnestičkih podataka i kliničkog i aku&scaron;erskog pregleda i potpisanog pisanog pristanka pacijenta o dobrovoljnom učestvovanju u istraživanju izvađena krv radi određivanja odabranih laboratorijskih parametara. Serumske koncentracije sFlt1, VEGF-A i PIGF određivane su kvantitativnom ELISA tehnikom (R&amp;D Systems Europe Ltd. Abingdon, UK), dok su: glukoza, ukupni holesterol, HDL holesterol, LDL holesterol, trigliceridi, apo-AI I apoB, AST, ALT, GGT, kreatinin, ureja, mokraćna kiselina, hsCRP, Na, K, Cl, Mg, P, Ca određivani na automatizovanim analizatorskim sistemima. Sve trudnice su kategorisane u 2 ispitivane i kontrolnu grupu na osnovu pojave ili isključenja hipertenzivnih oboljenja u aktuelnoj trudnoći. Statistička obrada podataka urađena je u statističkom programu STATISTICA 12 (StatSoft Inc.,Tulsa, OK, USA). Podaci su predstavljeni tabelarno i grafički, nivo statističe značajnosti p, je tumačen statistički značajnim ukoliko su vrednosti p&lt;0,05. REZULTATI: Vrednosti serumskih koncentracija sFlt-1 se statistički značajno razlikuju u sve tri grupe ispitanica i značajno su vi&scaron;e u grupama sa hipertenzivnim oboljenjima u odnosu na zdravu grupu ispitanica, p&lt;0,001. Serumske koncentracije VEGF-A su značajno niže u grupi trudnica sa preeklampsijom u odnosu na zdrave trudnice kontrolne grupe (p&lt;0,001), dok se nivoi serumskih koncentracija PlGF statistički značajno razlikuju između sve tri grupe trudnica tako da su najniže vrednosti uočene u grupi sa preeklampsijom (p&lt;0,001) u odnosu na preostale dve grupe ispitanica. Nije uočeno postojanje statistički značajne razlike u nivoima PAPP-A, biohemijskih parametara (glukoze, AST, ALT, GGT kreatinina, ureje, mokraćne kiseline), lipidskih parametara (uk. holesterol, LDL, apo A-I, apo B), parametara inflamatornog (kompletna krvna slika, fibrinogen), hemostaznog (D-dimer, vWF-antigen) i elektrolitskog statusa (Na, K, Cl, P, Mg), p&gt;0,05. Nivoi free &szlig;hCG i HDL holesterola su značajno niže, dok su vrednosti hsCRP i triglicerida značajno vi&scaron;e u grupi trudnica sa preeklampsijom u odnosu na grupu bez hipertenzivnih poremećaja u trudnoći. Serumske koncentracije sFlt-1 preko 865 pg/ml imaju senzitivnost od 93% i specifičnost od 81,5% u predviđanju nastanka preeklampsije, dok serumske koncentracije PlGF ispod 60 pg/ml senzitivnost od 88,4% i specifičnost od 79,6% u predviđanju pojave preeklampsije. Serumske koncentracije sFlt-1, VEGF-A i PlGF ne pokazuju statistički značajnu razliku u odnosu na godine života trudnice i broja prethodnih trudnoća p&gt;0,05. Serumske koncentracije sFlt-1 i PlGF se značajno razlikuju u odnosu na telesnu težinu novorođenčeta, tako da su niže vrednosti oba proteina detektovane u grupi novorođenčadi sa porođajnom težinom ispod 1500 gr. u odnosu na telesnu masu između 2800-3300 gr, p&lt;0,001. Takođe su nađene niže vrednosti sFlt-1 i PlGF u grupi trudnica koje su se porodile pre 33. nedelje gestacije u odnosu na nedelju gestacije u trenutku porođaja preko 37 nedelje gestacije, p&lt;0,001. Serumske koncentracije sFlt-1 i PlGF se značajno razlikuju u odnosu na indeks telesne mase majke tako da su vi&scaron;e vrednosti sFlt-1 i niže vednosti PlGF nađene u grupi trudnica sa indeksom telesne mase ispod 25 u odnosu na grupu trudnica sa indeksom telesne mase preko 30 kg/m2, p&lt;0,001. Serumske koncentracije sFlt-1 u prvom trimestru trudnoće su značajno povezane sa parametrima inflamacije (hsCRP), vrednostima dijastolnog krvnog pritiska i nivoima free &szlig;hCG. Takođe se uočava značajna povezanost koncentracije PlGF sa indeksom telesne mase, vrednostima sistolnog krvnog pritiska i koncentracijom hsCRP u prvom trimestru trudnoće. ZAKLJUČAK: Nivoi antiangiogenog proteina sFlt-1 su vi&scaron;e u grupi trudnica sa preeklampsijom u odnosu na grupu sa hroničnom i gestacijskom hipertenzijom i grupu trudnica bez hipertenzivnih poremećaja trudnoći. Nivoi proangiogenog proteina VEGF-A su značajno niže u grupi trudnica sa preeklampsijom i hroničnom i gestacijskom hipertenzijom u odnosu na grupu trudnica bez hipertenzivnih poremećaja u trudnoći. Serumske koncentracije proangiogenog proteina PlGF su niže u grupi trudnica sa preeklampsijom u odnosu na grupu sa hroničnom i gestacijskom hipertenzijom i grupu trudnica bez hipertenzivnih poremećaja trudnoći. Serumske koncentracije placentalnog proteina free &szlig;hCG i HDL holesterola su značajno niže, dok su vrednosti hsCRP i triglicerida značajno vi&scaron;e u grupi trudnica sa preeklampsijom u odnosu na grupu bez hipertenzivnih poremećaja u trudnoći. Između trudnica sa hipertenzivnim poremećajima u trudnoći i zdravih trudnica nije uočeno postojanje značajne razlike u vrednostima placentalnog proteina PAPP-A, biohemijskih parametara (glukoze, AST, ALT, GGT kreatinina, ureje, mokraćne kiseline), lipidskih parametara (uk. holesterol, LDL, apo A-I, apo B), parametara inflamatornog (kompletna krvna slika, fibrinogen), hemostaznog (D-dimer, vWF-antigen) i elektrolitskog statusa (Na, K, Cl, P, Mg). Serumske koncentracije sFlt-1 i PlGF se značajno razlikuju u odnosu na gestacijsku starost na porođaju i telesnu masu novorođenčeta i niže su kod trudnica koje su se prevremeno porodile kao i kod novorođenčati sa manjom porođajnom težinom. Serumske koncentracije sFlt-1 se značajno razlikuju u odnosu telesnu dužinu i APGAR skor novorođenčeta, tako da su vi&scaron;e vrednosti sFlt-1 udružene sa većom telesnom dužinom novorođenčeta i boljim APGAR skorom. Serumske koncentracije sFlt-1, VEGF-A i PlGF se ne razlikuju značajno u odnosu na godine života trudnice i broja prethodnih trudnoća. Nivoi proteina angiogeneze sFlt-1 i PlGF predstavljaju dobre prediktore u predviđanju nastanka preeklampsije u prvom trimestru trudnoće.</p> / <p>INTRODUCTION: Hypertensive disorders in pregnancy are a heterogeneous group of diseases that occur in 3-8% of all pregnancies. The most difficult forms of these diseases: preeclampsia, eclampsia and HELLP syndrome are the leading causes of maternal and fetal morbidity and mortality in relation to all other pregnancy complications. Etiopathogenesis of these diseases is still insufficiently understood but it is thought that the placenta plays a key role in the development of these complications, and that placental insufficiency, which occurs as a result of insufficient adaptation of decidual intramiometrial and parts of the spiral arteries in the first few weeks of pregnancy, leading to a reduction of utero- placental circulation and local placental hypoxia, which adversely affects the mother and the fetus. In order to elucidate the pathophysiological mechanisms of hypertensive disorders in pregnancy and to find sufficiently sensitive makers for early prediction of the most severe forms of these diseases, so far have been investigated a number of proteins involved in the processes of creation and development of placental vascular network such as vascular endothelial growth factor (VEGF-A), placental growth factor (PlGF) and soluble fms-like receptor tyrosine kinase receptor (sFlt-1). OBJECTIVE: The aim of the study was to compare serum concentration of sFlt-1, PlGF, VEGF-A, PAPP-A, free&szlig;hCG, glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, apo-AI, apo B, AST, ALT, GGT, creatinine, urea, uric acid, hsCRP, Na, K, Cl, P, Mg and Ca between the group of pregnant women with preeclampsia, chronic and gestational hypertension and the control group of pregnant women in the first trimester of pregnancy between 11 and 14 weeks gestation. Also the aim was to examine whether the value of selected laboratory parameters (sFlt-1, VEGF-A and PlGF) differ in relation to gestational week at the time of birth, weight, length and APGAR scoring system of newborns. The aim was to examine whether the value of angiogenic proteins: sFlt-1, VEGF-A and PlGF differ significantly in relation to the number of previous pregnancies and age of the pregnant woman. MATERIALS AND METHODS: The study was conducted as a prospective analytical study in the Clinical Center of Vojvodina, in the period from June 2012 to February 2015. The study included a total of 143 pregnant women aged 18 - 43 years. All pregnant women included in the study were divided into two study and one control group. The first study group consisted of 43 pregnant women who developed preeclampsia during the current pregnancy. The second study group consisted of 46 pregnant women who are newly diagnosed or confirmed chronic or gestational hypertension during the current pregnancy. The control group consisted of 54 healthy pregnant women with verified physiological outcome of pregnancy at term without maternal and fetal complications. Patients were included in the study between 11 + 0 and 13 + 6 weeks of gestation. All patients had data about risk factors for developing hypertensive disorders in pregnancy. After clinical and obstetric examination all patients underwent anthropometric measurements, measurement of blood pressure, and specialized ultrasound examination to determine precise gestational age of the fetus and to determine the risk for fetal chromosomal abnormalities. All patients signed a written consent of the patient&#39;s voluntary participation in the study. Serum levels of sFlt1, VEGF-A and PlGF were determined by quantitative ELISA (R &amp; D Systems Europe Ltd., Abingdon, UK), while glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, apo-AI, apo B, AST, ALT, GGT, creatinine, urea, uric acid, hsCRP, Na, K, Cl, P, Mg, Ca were determined on automated analyzer systems. All pregnant women were categorized into 2 study and a control group on the basis of presence of hypertensive disorders in the current pregnancy. Statistical analysis was performed in 12 statistical program STATISTICA (StatSoft Inc., Tulsa, OK, USA). The data are presented in tables and graphs, the level of significance p is interpreted statistically significant if the p value was less than &lt;0.05. RESULTS: Serum concentrations of sFlt-1 are statistically significantly different in all study groups and significantly higher in the groups with hypertensive disorders compared to healthy subjects p &lt;0.001. Serum levels of VEGF-A are significantly lower in the preeclampsia group compared to healthy control group (p &lt;0.001), while the levels of serum concentration of PlGF statistically significantly different between all groups so that the lowest values are observed in the preeclampsia group (p &lt;0.001) compared to the other two study groups. There is no statistically significant differences in the levels of PAPP-A, biochemical parameters (glucose, AST, ALT, GGT creatinine, urea, uric acid), lipid parameters (total cholesterol, LDL, apo AI, apo B), inflammatory parameters (complete blood count, fibrinogen), hemostatic (D-dimer, vWF-antigen) and electrolyte status (Na, K, Cl, P, Mg, Ca), p&gt; 0.05. Levels of free &szlig;hCG and HDL cholesterol levels are significantly lower, while the value of hsCRP and triglycerides significantly higher in the group of women with preeclampsia compared to the healthy control group. Serum concentrations of sFlt-1 over 865 pg/ml have a sensitivity of 93% and specificity of 81.5% in predicting preeclampsia, while serum PlGF concentration below 60 pg/ml, a sensitivity of 88.4% and a specificity of 79.6% in predicting preeclampsia. Serum concentrations of sFlt-1, VEGF-A and PlGF do not show a statistically significant difference compared to the age of pregnant women and the number of previous pregnancies p&gt; 0.05. Serum concentrations of sFlt-1 and PlGF are significantly different in relation to the weight of the newborn, so that the lower values of both proteins are in the group of infants with birth weight below 1500 gr. in relation to the body weight between 2800-3300 gr., p &lt;0.001. There is also lower concentrations of sFlt-1 and PlGF in a group with deliveries before 33 weeks of gestation compared to the deliveries after 37 week of gestation, p &lt;0.001. Serum concentrations of sFlt-1 and PlGF are significantly different in relation to the mother&#39;s body mass index so that the lower values of sFlt-1 and PlGF are in the group of women with a body mass index below 25 in relation to a group with a body mass index over 30 kg/m2, p &lt;0.001. Serum concentrations of sFlt-1 in the first trimester of pregnancy were significantly associated with the parameters of inflammation (hsCRP), diastolic blood pressure and levels of free &szlig;hCG. It is also observed a significant correlation between PlGF with a body mass index, systolic blood pressure and hsCRP concentration in the first trimester of pregnancy. CONCLUSION: The levels of anti-angiogenic protein sFlt-1 are higher in the group of pregnant women with preeclampsia than in the group with chronic and gestational hypertension and the control healthy group. Levels of proangiogenic VEGF-A protein are significantly lower in the preeclampsia group and group with gestational and chronic hypertension compared to the control group. Serum levels of proangiogenic PlGF protein are significantly lower in the preeclampsia group than in the group with chronic and gestational hypertension and the control group. Serum concentrations of placental protein free &szlig;hCG and HDL cholesterol are significantly lower, while the value of hsCRP and triglycerides significantly higher in the preeclampsia group compared to the control group. Among pregnant women with hypertensive disorders in pregnancy and healthy pregnant women there are no significant differences in the values of placental PAPP-A protein, biochemical parameters (glucose, AST, ALT, GGT creatinine, urea, uric acid), lipid parameters (total cholesterol, LDL, apo AI, apo B), inflammatory parameters (complete blood count, fibrinogen), hemostatic (D-dimer, vWF-antigen) and electrolyte status (Na, K, Cl, P, Mg, Ca). Serum concentrations of sFlt-1 and PlGF are significantly different in relation to gestational age at delivery and newborn body weight and are lower in group with preterm delivery and newborns with lower birth weight. Serum concentrations of sFlt-1 are significantly different compared to body length and Apgar score, so that the higher values of sFlt-1 are associated with better outcome of newborns (greater body length and better APGAR score). Serum concentrations of sFlt-1, VEGF-A and PlGF are not different significantly with respect to age of pregnancy and the number of previous pregnancies. The levels of sFlt-1 and PlGF represents helpful markers in prediction of preeclampsia in the first trimester of pregnancy.</p>

<p>Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer in part due to inherent resistance to chemotherapy, including the first-line drug gemcitabine. Gemcitabine is a nucleoside pyrimidine analog that has long been the backbone of chemotherapy for PDAC, both as a single agent, and more recently, in combination with nab-paclitaxel. Since gemcitabine is hydrophilic, it must be transported through the hydrophobic cell membrane by transmembrane nucleoside transporters. Human equilibrative nucleoside transporter-1 (hENT1) and human concentrative nucleoside transporter-3 (hCNT3) both have important roles in the cellular uptake of the nucleoside analog gemcitabine. While low expression of hENT1 and hCNT3 has been linked to gemcitabine resistance clinically, mechanisms regulating their expression in the PDAC tumor microenvironment are largely unknown. We identified that the matricellular protein Cysteine-Rich Angiogenic Inducer 61 (CYR61) negatively regulates expression of hENT1 and hCNT3. CRISPR/Cas9-mediated knockout of CYR61 significantly increased expression of hENT1 and hCNT3 and cellular uptake of gemcitabine. CRSIPR-mediated knockout of CYR61 sensitized PDAC cells to gemcitabine-induced apoptosis. Conversely, adenovirus-mediated overexpression of CYR61 decreased hENT1 expression and reduced gemcitabine-induced apoptosis. We demonstrate that CYR61 is expressed primarily by stromal pancreatic stellate cells (PSCs) within the PDAC tumor microenvironment, with Transforming Growth Factor- β (TGF-β) inducing the expression of CYR61 in PSCs through canonical TGF-β-ALK5-Smad signaling. Activation of TGF-β signaling or expression of CYR61 in PSCs promotes resistance to gemcitabine in an in vitro co-culture assay with PDAC cells. Our results identify CYR61 as a TGF-β induced stromal-derived factor that regulates gemcitabine sensitivity in PDAC and suggest that targeting CYR61 may improve chemotherapy response in PDAC patients.</p> / Dissertation

Le faible poids de naissance (FPN) est un facteur de risque indépendant reconnu de maladies cardiovasculaires et d'hypertension à l'âge adulte, mais les mécanismes physiopathologiques sous-tendant cette programmation précoce ne sont que partiellement connus. Chez l'adulte, la dysfonction endothéliale et l'altération tant quantitative que qualitative de la cellule progénitrice endothéliale (PEC) sont un marqueur précoce et sensible de risque cardiovasculaire. Des altérations vasculaires (raréfaction microvasculaire, anomalies de la structure vasculaire) et une dysfonction endothéliale (altération de la vasodilatation endothélium-dépendante) sont retrouvées chez le nouveau-né de FPN. Cependant, l'hypothèse d'une altération de la cellule progénitrice endothéliale chez le nouveau-né de FPN reste à être démontrée. Au cours de notre travail, nous avons montré une altération des capacités clonogéniques et angiogéniques des PECs des nouveau-nés de FPN, tant in vitro qu'in vivo. Cette dysfonction pourrait être liée à un déséquilibre antiangiogénique d'origine environnementale conduisant à un profil antiangiogénique d'expression génique de la PEC. Ainsi, nous avons pu montrer qu'une surexpression du gène de la thrombospondine-1 pouvait en partie expliquer la réduction du potentiel angiogénique des PECs du nouveau-né de FPN via une inhibition de la transduction du signal de la voie Akt/PI3K. D'autre part, une diminution des concentrations circulantes de VEGF, dont le rôle critique dans la néovascularisation est bien connu, peut-être liée à une augmentation de son inhibiteur circulant, sFlt1 (récepteur soluble au VEGF), a été retrouvée chez le nouveau-né de FPN. / Low birth weight (LBW) is a risk factor for cardiovascular disease in adulthood. However, the mechanisms explaining cardiovascular programming are incompletely understood. In adults, a reduced level of circulating endothelial progenitor cells (EPCs) is correlated with cardiovascular disease and independently predicts atherosclerosis disease progression. Recent studies demonstrated an impairment of vascular structure (microvascular rarefaction) and function (impaired vasodilation) in LBW neonates. Thus, we hypothesized that LBW infants display an EPCs impairment.We demonstrated an alteration of clonogenic and angiogenic capacities of EPCs fropm LBW infants, both in vitro and in vivo. This could be due to a fetal antiangiogenic imbalance and a subsequent antiangiogenic gene expression profile in EPCs of LBW infants. Through an inhibition of Akt/PI3K signaling, an upregulation of thrombospondin-1 expression could partially explain such observations. Moreover, VEGF pathway, the main angiogenesis regulator, could be involved as we found reduced circulating levels of VEGF, probably due to an increase of its main inhibitor, sFlt1 (soluble receptor of VEGF 1) in LBW infants. The addition of VEGF reversed the in vitro negative effect of LBW infants' sera on EPCs angiogenic function.This investigation opens the way for more studies of EPCs function in LBW subjects. Indeed, many questions emerged about the impact of such dysfunction on the future health of LBW infants.