24 results on '"Elena Kistanova"'
Search Results
2. Influence of Ovarian Status and Steroid Hormone Concentration on Day of Timed Artificial Insemination (TAI) on the Reproductive Performance of Dairy Cows Inseminated with Sexed Semen
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Stanimir Yotov, Ivan Fasulkov, Anatoli Atanasov, Elena Kistanova, Branimir Sinapov, Boyana Ivanova, Dobri Yarkov, and Darina Zaimova
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cows ,ovarian status ,steroid hormones ,pregnancy ,sexed semen ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
This study aimed to evaluate the effect of the ovarian status and steroid hormone concentration on the day of TAI on the reproductive performance of dairy cows subjected to estrus synchronization treatment and timed artificial insemination with sexed semen. Seventy-eight cyclic Holstein cows pre-treated with PGF2α-GnRH were divided in two groups—I (Preselect-OvSynch, n = 38) and II (OvSynch+PRID-7-day+eCG, n = 40)—and inseminated with sexed semen. The presence of preovulatory follicle (PF) with or without corpus luteum (CL), the PF diameter, the estradiol (E2) and progesterone (P4) concentrations on the day of TAI, the pregnancy rate (PR) and embryo loss were determined. On the day of TAI, 78.4% of all the pregnant cows presented a PF (mean size 1.80 ± 0.12 cm) without CL, low P4 (0.59 ± 0.28 ng/mL) and high E2 (12.35 ± 2.62 pg/mg) concentrations. The positive correlation between the size of the PF and the level of E2 in the pregnant cows from group II was stronger than that of group I (R = 0.82 vs. R = 0.52, p < 0.05). The pregnancy rate on day 30 (57.5% vs. 36.8%) and day 60 (50% vs. 26.3%; p < 0.05) and the embryo losses (13% vs. 28.5%) showed better effects of treatment in group II. In conclusion, the ovarian status and the steroid hormone concentration on the day of TAI influence the pregnancy rates of dairy cows subjected to estrus synchronization and timed artificial insemination with sexed semen. more...
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- 2023
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3. Oregonin from Alnus incana bark affects DNA methyltransferases expression and mitochondrial DNA copies in mouse embryonic fibroblasts
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Jelena Krasilnikova, Liga Lauberte, Elena Stoyanova, Desislava Abadjieva, Mihail Chervenkov, Mattia Mori, Elisa De Paolis, Vanya Mladenova, Galina Telysheva, Bruno Botta, and Elena Kistanova
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Oregonin ,Alnus incana bark ,DNA methyltransferases mRNAs ,mtDNA copy ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Oregonin is an open-chain diarylheptanoid isolated from Alnus incana bark that possesses remarkable antioxidant and anti-inflammatory properties, inhibits adipogenesis, and can be used in the prevention of obesity and related metabolic disorders. Here, we aimed to investigate the effects of oregonin on the epigenetic regulation in cells as well as its ability to modulate DNA methylating enzymes expression and mitochondrial DNA (mtDNA) copies. Our results show that oregonin altered the expression of DNA methyltransferases and mtDNA copy numbers in dependency on concentration and specificity of cells genotype. A close correlation between mtDNA copy numbers and mRNA expression of the mtDnmt1 and Dnmt3b was established. Moreover, molecular modeling suggested that oregonin fits the catalytic site of DNMT1 and partially overlaps with binding of the cofactor. These findings further extend the knowledge on oregonin, and elucidate for the first time its potential to affect the key players of the DNA methylation process, namely DNMTs transcripts and mtDNA. more...
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- 2018
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4. Resumption of Cyclic Ovarian Activity by Herbal Preparation AyuFertin in Bulgarian Murrah Buffaloes at Early Postpartum
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Yordanka Ilieva, Nasko Vasilev, Ivan Fasulkov, Pencho Penchev, Desislava Abadjieva, Vanya Mladenova, Ayla Ilyazova, Dasha Mihaylova, Stanimir Yotov, and Elena Kistanova
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postpartum buffalo ,AyuFertin treatment ,ovarian activity ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
This study evaluates the phytochemical composition and ability of herbal preparation AyuFertin, supplemented shortly after calving, to resume the cyclic ovarian activity in postpartum Bulgarian Murrah buffaloes. In total, 13 healthy Bulgarian Murrah buffaloes at the age of 4–10 years, calved in March–April 2019 were involved in the experiment. Seven experimental buffaloes were treated individually per os with AyuFertin according to producer instruction. All animals were subjected to regular ultrasound examination of ovaries. GC-MS analysis of fatty acids composition and HPLC-DAD analysis of carotenoid and tocopherol content in AyuFertin were conducted. The determination of estrus occurrence and natural mating were done by a fertile bull. The development of the large follicles (12.5–14.3 mm) in 85.7% of treated animals was observed on day 24 postpartum compared to 0% in controls. Clinical signs of estrus were recorded in 71.4% of the animals, followed by an 80% pregnancy rate versus 16% in controls within 70 days after calving. In conclusion, the supplementation of the bioactive herbal product AyuFertin from day 21 postpartum can stimulate the follicular growth in the buffalo’s ovary, which leads to the development of follicles with ovulatory capacity, followed by successful ovulation. The above-mentioned treatment resulted in a better pregnancy rate in the treated multiparous compared to the control buffaloes bred by natural service. more...
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- 2021
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5. Tribulus terrestris Alters the Expression of Growth Differentiation Factor 9 and Bone Morphogenetic Protein 15 in Rabbit Ovaries of Mothers and F1 Female Offspring.
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Desislava Abadjieva and Elena Kistanova
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Medicine ,Science - Abstract
Although previous research has demonstrated the key role of the oocyte-derived factors, bone morphogenetic protein (BMP) 15 and growth differentiation factor (GDF) 9, in follicular development and ovulation, there is a lack of knowledge on the impact of external factors, which females are exposed to during folliculogenesis, on their expression. The present study investigated the effect of the aphrodisiac Tribulus terrestris on the GDF9 and BMP15 expression in the oocytes and cumulus cells at mRNA and protein levels during folliculogenesis in two generations of female rabbits. The experiment was conducted with 28 New Zealand rabbits. Only the diet of the experimental mothers group was supplemented with a dry extract of T. terrestris for the 45 days prior to insemination. The expression of BMP15 and GDF9 genes in the oocytes and cumulus cells of mothers and F1 female offspring was analyzed using real-time polymerase chain reaction (RT-PCR). The localization of the GDF9 and BMP15 proteins in the ovary tissues was determined by immunohistochemical analysis. The BMP15 and GDF9 transcripts were detected in the oocytes and cumulus cells of rabbits from all groups. T. terrestris caused a decrease in the BMP15 mRNA level in the oocytes and an increase in the cumulus cells. The GDF9 mRNA level increased significantly in both oocytes and cumulus cells. The downregulated expression of BMP15 in the treated mothers' oocytes was inherited in the F1 female offspring born to treated mothers. BMP15 and GDF9 show a clearly expressed sensitivity to the bioactive compounds of T. terrestris. more...
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- 2016
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6. Endocrine disrupting chemicals and their detection in an IVF laboratory
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Michal Ješeta, Kateřina Franzová, Lenka Mekiňová, Elena Kistanova, Peter Harbulák, Jana Žáková, Eva Lousová, Pavel Ventruba, and Igor Crha
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Cell Biology ,Molecular Biology - Abstract
The endocrine disruptors are chemicals with the capacity to influence physiological processes in the organism, most often through hormonal control. They are present in the environment and in the products of daily use. They are often found in food, released from plastic bottles for water, present in cosmetics or fertilizers. Latest research suggests that they can be released from plastics used in the IVF laboratories and can be even present in the manipulation and cultivation media used for isolation and fertilization of gametes and subsequent cultivation of embryos. Permanent and long-term utilization of these substances has adverse effects in human reproductive health, mainly by the means of interfering with synthesis and action mechanisms of reproductive hormones. Moreover, some endocrine disruptors show a range of adverse effects directly on the gametes or embryos cultured in the in vitro conditions. The article provides an overview on bisphenols detected in plastics and media commonly used in the IVF laboratory and considers their possible impact on effectiveness of the IVF methods in a human laboratory. more...
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- 2021
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7. New gene markers involved in regulation of granulosa cells development and differentiation towards endodermal and epithelial tissues – a new insight into the stemness specificity of ovarian follicular cells
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Wiesława Kranc, Małgorzata Popis, Claudia Dompe, Afsaneh Golkar-Narenji, Michal Jeseta, Paul E Mozdziak, Elena Kistanova, Alexander Makarevich, Marie Machatkova, Dorota Bukowska, Radek Prochazka, Jędrzej M. Jaśkowski, Kornel Ratajczak, Jarosław Sobolewski, and Paweł Antosik more...
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endocrine system ,Cell Biology ,Molecular Biology ,hormones, hormone substitutes, and hormone antagonists - Abstract
Maintaining of female fertility is strictly dependent on proper hormonal regulation. Granulosa cells (GCs) are components of ovarian follicles, and they are important in paracrine regulation of the ovary. Preovulatory follicle GCs are responsible for production of estrogens to the ovary microenvironment and lead to the LH surge. Proper functioning of GCs is necessary to ensure appropriate conditions for oocyte development, maturation, ovulation and its release to the oviduct. Long-term in vitro culture of GCs show significant stem-like characteristics. Understanding the molecular processes underlying GCs differentiation towards different cell lineages may reveal other possible stem cell markers. A transcriptomic analysis of short-term primary in vitro cultured GCs, which were isolated from porcine preovulatory follicles was the major focus of the study. The ontological groups herby considered are associated with endodermal and epithelial tissues. Results were and compare to freshly isolated GC cells. 6 the most reduced expression: HSD17B1, DAPL1, NEBL, MAL2, DAB1, ITM2A were chosen for analysis. These genes have been response for processes associated with GCs development and differentiation towards endodermal and epithelial tissues, which make them important for further consideration. more...
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- 2021
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8. Challenges of stem cell application in research and clinical practice – an update
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Maurycy Jankowski, Marie Machatkova, Pavel Ventruba, Elena Kistanova, Alexander Makarevich, Radek Prochazka, and Michal Jeseta
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Cell Biology ,Molecular Biology - Abstract
There are multiple possible applications of stem cells in medicine, from cell-based therapies for degenerative and dystrophic conditions, through novel approaches in cancer treatment, to in vitro organ printing. However, there are still several challenges that need to be overcame before stem cells therapies can be successfully introduced worldwide on a large scale. These include sourcing of stem cells, preventing their aberrant progression and ethical concerns regarding their use in animals and humans. Among the multiple stem cell types present in the human organism from the period of embryonic development to adulthood, this review focuses on the three types that gain the most attention in relation to modern research: embryonic stem cells, induced pluripotent stem cells and adult stem cells. There are a number of obstacles that need to be removed before these cells can be widely applied in clinical practice, including the choice of the perfect source of stem cells, full elucidation of the mechanisms of stem cell differentiation and plasticity, and minimization of adverse side effect potential. Nonetheless, the focus of the scientific community on the topic of stem cells remains unhindered, bringing hope that all of the possible concerns will be addressed in the future. more...
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- 2021
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9. Systematic analysis of nutrigenomic effects of polyphenols related to cardiometabolic health in humans – Evidence from untargeted mRNA and miRNA studies
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Tatjana Ruskovska, Irena Budić-Leto, Karla Fabiola Corral-Jara, Vladimir Ajdžanović, Anna Arola-Arnal, Francisca Isabel Bravo, Georgia-Eirini Deligiannidou, Jaroslav Havlik, Milkica Janeva, Elena Kistanova, Christos Kontogiorgis, Irena Krga, Marika Massaro, Marko Miler, Hicham Harnafi, Verica Milosevic, Christine Morand, Egeria Scoditti, Manuel Suárez, David Vauzour, Dragan Milenkovic, University Goce Delcev (UGD), Institute for Adriatic Crops and Karst Reclamation, Unité de Nutrition Humaine (UNH), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Clermont Auvergne (UCA), University of Belgrade [Belgrade], Universitat Rovira i Virgili, Democritus University of Thrace (DUTH), Czech University of Life Sciences Prague (CZU), Bulgarian Academy of Sciences (BAS), Natl Res Council CNR, Inst Ecosyst Study ISE, Res Unit Pisa, Pisa, Italy, Univ Mohammed 1, Oujda, Morocco, University of East Anglia [Norwich] (UEA), University of California [Davis] (UC Davis), and University of California (UC) more...
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Aging ,Bioinformatics ,[SDV.MHEP.GEG]Life Sciences [q-bio]/Human health and pathology/Geriatry and gerontology ,Cardiometabolic health ,Polyphenols ,Integrated multi-omics ,Genomics ,[SDV.BC]Life Sciences [q-bio]/Cellular Biology ,Biochemistry ,MicroRNAs ,Nutrigenomics ,Neurology ,Cardiovascular Diseases ,Humans ,RNA, Messenger ,Molecular Biology ,Biotechnology - Abstract
International audience; Cardiovascular and metabolic disorders present major causes of mortality in the ageing population. Polyphenols present in human diets possess cardiometabolic protective properties, however their underlying molecular mechanisms in humans are still not well identified. Even though preclinical and in vitro studies advocate that these bioactives can modulate gene expression, most studies were performed using targeted approaches. With the objective to decipher the molecular mechanisms underlying polyphenols cardiometabolic preventive properties in humans, we performed integrative multi-omic bioinformatic analyses of published studies which reported improvements of cardiometabolic risk factors following polyphenol intake, together with genomic analyses performed using untargeted approach. We identified 5 studies within our criteria and nearly 5000 differentially expressed genes, both mRNAs and miRNAs, in peripheral blood cells. Integrative bioinformatic analyses (e.g. pathway and gene network analyses, identification of transcription factors, correlation of gene expression profiles with those associated with diseases and drug intake) revealed that these genes are involved in the processes such as cell adhesion and mobility, immune system, metabolism, or cell signaling. We also identified 27 miRNAs known to regulate processes such as cell cytoskeleton, chemotaxis, cell signaling, or cell metabolism. Gene expression profiles negatively correlated with expression profiles of cardiovascular disease patients, while a positive correlation was observed with gene expression profiles following intake of drugs against cardiometabolic disorders. These analyses further advocate for health protective effects of these bioactives against age-associated diseases. In conclusion, polyphenols can exert multigenomic modifications in humans and use of untargeted methods coupled with bioinformatic analyses represent the best approach to decipher molecular mechanisms underlying healthy-ageing effects of these bioactives. more...
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- 2022
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10. Systematic bioinformatic analysis of nutrigenomic data of flavanols in cell models of cardiometabolic disease
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Irena Krga, Pedro Mena, Christine Morand, Claudia Nunes dos Santos, Dragan Milenkovic, Ana Rodriguez-Mateos, Egeria Scoditti, Manuel Suarez, Elena Kistanova, Sonia De Pascual-Teresa, Marie-Paule Gonthier, Maria Annunziata Carluccio, Eileen R. Gibney, Emilie Combet, Nadia Calabriso, Francisca Isabel Bravo, Ken Declerk, Wim Vanden Berghe, Begona Muguerza, Anna Arola-Arnal, Andreia Gomes, Marika Massaro, Tatjana Ruskovska, Emilie Combet, Ana Rodriguez-Mateos, Andreia Gomes, Marika Massaro, Manuel Suarez Recio, Wim Vanden Berghe, Anna Arola-Arnal, Tatjana Ruskovska, Begoña Muguerza, Claudia N Santos, Elena K Kistanova, Irena Krga, Egeria Scoditti, Sonia de Pascual-Teresa, Francisca Isabel Bravo, Claudia Nunes dos Santos, and Pedro Mena more...
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flavanols, bioinformatic analysis, nitrigenomic, cardiometabolic disease - Published
- 2020
11. DOSE- DEPENDENT EFFECT OF TRIBULUS TERRESTRIS DRY EXTRACT ON REPRODUCTIVE ORGANS OF GROWING MALE RABBITS
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Desislava Abadjieva, Svetlana Grigorova, Natasha Gjorgovska, and Elena Kistanova
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- 2019
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12. Drone brood fed supplement impacts on the folliculogenesis in growing gilts
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Elena Kistanova, Elena Zdoroveva, Michail Nevitov, Aleksey Nosov, Mikhail Vysokikh, Iuliia Sukhanova, Polina Vishnyakova, Desislava Abadjieva, Desislava Ankova, Pavel Rashev, Gennadi Boryaev, Elena Kistanova, Elena Zdoroveva, Michail Nevitov, Aleksey Nosov, Mikhail Vysokikh, Iuliia Sukhanova, Polina Vishnyakova, Desislava Abadjieva, Desislava Ankova, Pavel Rashev, and Gennadi Boryaev more...
- Abstract
The biological properties of bee drone brood make it an ideal additive for growth promotion in animal husbandry instead of banned hormonal anabolics and antibiotics. However, the drone brood action on mammalian ovaries has not been well studied. The present study analyzes the impact of drone brood homogenate (DBH) in the diet of growing gilts on folliculogenesis. Large White female pigs at the age of 35 days were randomly divided into two groups of 10 animals each, and fed with the same basal diets. The experimental group was supplemented with 25 mg/kg forage of DBH for 180 days, after which the animals were slaughtered and morphometric, histological and immunohistochemical evaluation of their ovaries was performed. In addition, the expression of ovarian growth factors BMP15 and GDF9 in oocytes and cumulus cells was analyzed by RT-PCR. A significant increase in body weight and average daily gain at day 145 in the DBH-supplemented group was established. The length of the ovaries in the treated animals also was enhanced. More pools of primordial follicles, involved in intensive growth, as well as a larger diameter of primary and tertiary follicles were found in the ovaries of DBH-supplemented animals. These findings corresponded with an increase in the expression of GDF9 mRNA in the oocytes and cumulus cells. At the same time, signs of atresia in the Graafian follicles of treated animals were observed. The supplementation with DBH stimulates the early stages of folliculogenesis in gilts, but provokes atresia in the last stage of follicular development., Biološka svojstva pčelinjeg trutovskog legla čine ga idealnim dodatkom za poboljšanje rasta u stočarstvu umjesto zabranjenih hormonskih anabolika i antibiotika. Ipak, utjecaj trutovskog legla na jajnike u sisavaca još uvijek nije dovoljno istražen. U ovom se radu analiziran je utjecaj homogenata trutovskog legla (DBH) u prehrani nazimica na folikulogenezu. Ženke pasmine veliki jorkšir u dobi od 35 dana nasumično su podijeljene u dvije skupine po 10 životinja, s jednakim osnovnim prehrambenim obrokom. Pokusnoj skupini u krmu je dodavano 25 mg/kg DBH-a tijekom 180 dana, nakon čega su životinje usmrćene te je učinjena morfometrijska, histološka i imunohistokemijska procjena jajnika. Zatim je u oocitama i stanicama kumulusa RT-PCR-om analiziran izražaj faktora rasta jajnika, BMP15 i GDF9. U skupini s dodatkom prehrani DBH ustanovljen je znakovit porast tjelesne mase i prosječnog dnevnog prinosa 145. dan. Povećana je i dužina jajnika u pokusnih životinja. U životinja hranjenih dodatkom pronađeno je više nakupina primordijalnih folikula uključenih u intenzivan rast, kao i veći promjer primarnih i tercijarnih folikula. Ovi su rezultati u skladu s porastom izražaja GDF9 mRNA u oocitama i stanicama kumulusa. Istodobno su opaženi znakovi atrezije u Graafovim folikulima pokusnih životinja. Dodatak prehrani DBH stimulira rane stadije folikulogeneze u nazimica, ali uzrokuje atreziju u posljednjem stadiju folikularnog razvoja. more...
- Published
- 2020
13. Editorial
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Dimitrina Kacheva, Elena Kistanova, Boyko Georgiev, Desislava Abadjieva, Stanimir Yotov, Maya Ignatova, Vassil Nikolov, and Boyko Likov
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Europe ,Endocrinology ,Animals, Domestic ,Reproduction ,Animals ,Animal Science and Zoology ,Congresses as Topic ,Societies, Medical ,Biotechnology - Published
- 2015
14. Structure, Polymorphism and Regulation of Tumor Necrosis Factor Genes at Genomic Loci
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Elena Kistanova, Regina L. Turetskaya, Irina A. Udalova, Dmitry V. Kuprash, Mark Boldin, Sergei A. Nedospasov, and Julia Smirnova
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Genetics ,Tumor necrosis factor alpha ,Biology ,Molecular biology ,Gene - Published
- 2015
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15. Enhanced Pharmacokinetics of Factor VIIa as a Monomeric Fc Fusion
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Robert T. Peters, Tongyao Liu, Nancy Moore, Tamera Ashworth, Joe Salas, Qi Lu, Glenn F. Pierce, John Kulman, Haiyan Jiang, and Elena Kistanova
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Male ,Recombinant Fusion Proteins ,Population ,Factor VIIa ,Receptors, Fc ,Pharmacology ,Hemophilia A ,law.invention ,chemistry.chemical_compound ,Tissue factor ,Mice ,Neonatal Fc receptor ,Pharmacokinetics ,law ,medicine ,Animals ,Humans ,education ,Factor IX ,Mice, Knockout ,education.field_of_study ,biology ,business.industry ,Factor X ,Histocompatibility Antigens Class I ,Hematology ,Immunoglobulin Fc Fragments ,Mice, Inbred C57BL ,Disease Models, Animal ,chemistry ,Recombinant factor VIIa ,Immunology ,Recombinant DNA ,biology.protein ,Prothrombin Time ,business ,medicine.drug ,Half-Life - Abstract
Recombinant Factor VIIa (rFVIIa) is utilized for on-demand treatment of bleeding episodes in hemophilia patients with neutralizing antibodies (inhibitors) against Factor VIII or Factor IX, but a short half-life in the circulation (~2.5hrs) limits its use in a prophylactic setting. Recombinant FVIIa variants with improved pharmacokinetic properties may enable improved treatment and prevention of bleeding episodes in the inhibitor population. In this study we describe recombinant FVIIaFc (rFVIIaFc), a recombinant Fc-fusion protein generated to utilize the neonatal Fc receptor (FcRn)-mediated recycling pathway that protects immunoglobulin G from catabolism. On the basis of activity, rFVIIaFc exhibited a 5.5-fold extension in terminal half-life in hemophilia A mice compared to rFVIIa. The potency of rFVIIaFc was comparable to that of rFVIIa in thrombin generation assay and ROTEM. In agreement with these data, rFVIIaFc and rFVIIa showed similar acute efficacy at comparable molar doses in the tail clip bleeding model in hemophilia A mice. Taken together, these studies demonstrate enhanced pharmacokinetics and similar hemostatic properties for rFVIIaFc compared to rFVIIa. more...
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- 2014
16. Functional Domains of the Nuclear Receptor Hepatocyte Nuclear Factor 4
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Margarita Hadzopoulou-Cladaras, Catherine Evagelopoulou, Elena Kistanova, C Cladaras, John A.A. Ladias, and Shengyou Zeng
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Transcriptional Activation ,Macromolecular Substances ,Molecular Sequence Data ,Receptors, Cytoplasmic and Nuclear ,Biology ,digestive system ,Biochemistry ,Protein Structure, Secondary ,Structure-Activity Relationship ,Transactivation ,Animals ,Amino Acid Sequence ,Apolipoproteins C ,Molecular Biology ,Nuclear receptor co-repressor 1 ,Apolipoproteins B ,Sequence Deletion ,Nuclear receptor co-repressor 2 ,Genetics ,Apolipoprotein C-III ,Cell Biology ,Phosphoproteins ,Rats ,Cell biology ,DNA-Binding Proteins ,Nuclear receptor coactivator 1 ,Gene Expression Regulation ,Hepatocyte Nuclear Factor 4 ,Liver ,Hepatocyte nuclear factor 4 ,Nuclear receptor ,Trans-Activators ,Nuclear receptor coactivator 2 ,Small heterodimer partner ,Sequence Alignment ,Transcription Factors - Abstract
The hepatocyte nuclear factor 4 (HNF-4) is a member of the nuclear receptor superfamily and participates in the regulation of several genes involved in diverse metabolic pathways and developmental processes. To date, the functional domains of this nuclear receptor have not been identified, and it is not known whether its transcriptional activity is regulated by a ligand or other signals. In this report, we show that HNF-4 contains two transactivation domains, designated AF-1 and AF-2, which activate transcription in a cell type-independent manner. AF-1 consists of the extreme N-terminal 24 amino acids and functions as a constitutive autonomous activator of transcription. This short transactivator belongs to the class of acidic activators, and it is predicted to adopt an amphipathic alpha-helical structure. In contrast, the AF-2 transactivator is complex, spanning the 128-366 region of HNF-4, and it cannot be further dissected without impairing activity. The 360-366 region of HNF-4 contains a motif that is highly conserved among transcriptionally active nuclear receptors, and it is essential for AF-2 activity, but it is not necessary for dimerization and DNA binding of HNF-4. Thus, HNF-4 deletion mutants lacking the 361-465 region bind efficiently to DNA as homo- and heterodimers and behave as dominant negative mutants. Remarkably, the full transactivation potential of AF-2 is inhibited by the region spanning residues 371-465 (region F). The inhibitory effect of region F on the HNF-4 AF-2 activity is a unique feature among members of the nuclear receptor superfamily, and we propose that it defines a distinct regulatory mechanism of transcriptional activation by HNF-4. more...
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- 1997
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17. In vivo electroporation and stable transformation of skin cells of newborn mice by plasmid DNA
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Alexander V. Titomirov, Elena Kistanova, and S.A Sukharev
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Biophysics ,Gene electrotransfer ,Biology ,Transfection ,Biochemistry ,Mice ,Plasmid ,Electricity ,Structural Biology ,In vivo ,Genetics ,Animals ,Cell Line, Transformed ,Skin ,integumentary system ,Electroporation ,Genetic transfer ,Nucleic Acid Hybridization ,DNA ,Fibroblasts ,Blotting, Northern ,Molecular biology ,Blotting, Southern ,Transformation (genetics) ,Animals, Newborn ,Cell culture ,Mice, Inbred CBA ,RNA ,Plasmids - Abstract
The skin cells of newborn mice were stably transformed in vivo with the aid of electroporation. The plasmid DNA was introduced subcutaneously followed by high-voltage pulses applied to the skin pleat. NEO-resistant colonies were found in primary cell cultures obtained from the treated skin. The experiments show that in vivo electroporation can be used for the introduction of plasmid DNA into skin cells of mouse. more...
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- 1991
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18. Platelet-Targeted rFVIIa-Xten Improves Thrombin Generation and Fibrin Formation Compared to Recombinant FVIIa
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Volker Schellenberger, Robert T. Peters, Joe Salas, Elena Kistanova, Nancy Moore, and Maria M. Aleman
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biology ,business.industry ,Immunology ,Cell Biology ,Hematology ,Pharmacology ,Biochemistry ,Fibrin ,Tissue factor ,Pharmacokinetics ,In vivo ,Recombinant factor VIIa ,biology.protein ,Thromboplastin ,Medicine ,Platelet ,Antibody ,business - Abstract
The development of inhibitors to replacement plasma factors in hemophilia is an ongoing clinical complication. Bypass therapies, such as recombinant factor VIIa (rFVIIa), have emerged as important alternative on-demand strategies for hemophilic patients with inhibitors to treat spontaneous bleeds and prevent bleeding during surgery. However, general prophylaxis strategies for hemophilia inhibitor patients are lacking. An attractive approach for effective prophylaxis and on-demand treatment includes engineering potent rFVIIa variants with prolonged pharmacokinetics. Because the primary mechanism of action of rFVIIa is thought to occur on the platelet surface, we combined rFVIIa with platelet-targeting and XTEN half-life extension technologies to improve its pharmacokinetic profile and procoagulant activity. Platelet-targeting was achieved by recombinant fusion of an antibody fragment which binds the human alpha IIb integrin. Half-life extension was achieved by fusion of an XTEN polypeptide which increases the hydrodynamic radius, and therefore half-life, of rFVIIa. We have shown that these rFVIIa modifications improve the pharmacokinetics and efficacy of rFVIIa in vivo in humanized alpha IIb transgenic hemophilia A mice. The goal of the current study was to evaluate and compare thrombin generation and fibrin formation kinetics in hemophilic platelet-rich plasma in the presence of platelet-targeted rFVIIa-XTEN or rFVIIa. To achieve this, platelet-rich plasma from normal human donors was treated with an inhibitory factor VIII antibody to model hemophilia A and spiked with doses of platelet-targeted rFVIIa-XTEN or rFVIIa. Reactions were triggered with low tissue factor and recalcification. Thrombin generation (n=9) was monitored by calibrated automated thrombography and fibrin formation (n=7) was monitored optically on a plate reader. Non-linear regression analysis of dose responses was used to determine EC50 values for each parameter for each donor. Platelet-targeted rFVIIa-XTEN increases the rate and peak of thrombin generation with 2- to 6-fold lower EC50 values (peak and rate, respectively) than rFVIIa. These data were confirmed by thrombin generation in platelet-rich plasma from 1 hemophilia A donor and 1 hemophilia B donor which demonstrated similar responses to platelet-targeted rFVIIa-XTEN with 2.5- to 5-fold lower EC50 values (peak and rate, respectively) than rFVIIa. Notably, platelet count-dependent changes in thrombin generation activity were similar between platelet-targeted rFVIIa-XTEN and rFVIIa. Fibrin formation analysis indicated platelet-targeted rFVIIa-XTEN increases the rate and time to plateau of fibrin formation with 5- to 13-fold lower EC50 values (rate and time to plateau, respectively) than rFVIIa. Analysis of fibrin network structure by confocal microscopy indicated platelet-targeted rFVIIa-XTEN increases fibrin network density in platelet-rich plasma clots. Together, these data show platelet-targeted rFVIIa-XTEN has more procoagulant activity than rFVIIa by supporting more thrombin generation and faster fibrin formation and suggest our approach has the potential to be an effective alternative for the treatment and prevention of bleeds in hemophilia patients with inhibitors. Disclosures Aleman: Biogen: Employment, Equity Ownership. Kistanova:Biogen: Employment, Equity Ownership. Moore:Biogen: Employment, Equity Ownership. Schellenberger:Amunix Operating Inc: Employment. Peters:Biogen: Employment. Salas:Biogen: Employment, Equity Ownership. more...
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- 2015
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19. Enhancing the Acute Hemostatic Efficacy in Cynomolgus Monkeys By Targeting Activated Coagulation Factor VII to Platelets
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Elena Kistanova, Robert T. Peters, Marisol Acosta, Sarah Smith, David R. Light, Kai Chen, Haiyan Jiang, Tamera Ashworth, Nancy Moore, Joe Salas, Siyuan Tan, and Anxhela Kole
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Prothrombin time ,medicine.medical_specialty ,Hematology ,medicine.diagnostic_test ,business.industry ,Immunology ,Cell Biology ,Pharmacology ,Biochemistry ,Thromboelastometry ,hemic and lymphatic diseases ,Internal medicine ,Pharmacodynamics ,medicine ,Platelet ,business ,Whole blood ,Tenase ,Factor IX ,medicine.drug - Abstract
Recombinant activated factor VII (rFVIIa) is used for controlling bleeds in hemophilia A and B patients with inhibitory antibodies against factor VIII or factor IX. The hemostatic effect of rFVIIa at pharmacological doses is believed to be mediated by activating the tenase complex on platelets directly at the site of injury to promote thrombin generation. To increase the hemostatic activity of rFVIIa, we sought to target rFVIIa to platelets by fusing a single chain variable region of a monoclonal antibody against human platelet receptor αIIbβ3. The resulting fusion protein, FVII-189, displays higher affinity to human platelets and about 50-fold higher hemostatic activity than that of rFVIIa in whole blood from hemophilia A patients by rotational thromboelastometry (ROTEM). Here we investigated the safety, pharmacokinetics, and pharmacodynamics of FVII-189 in cynomolgus monkeys. First, we confirmed that FVII-189 cross-reacted to platelets from cynomolgus monkeys. When spiked in the monkey whole blood, FVII-189 could bind platelets in a dose-dependent manner, as measured by flow cytometry using fluorescently labeled antibodies against FVII, whereas platelet-binding by rFVIIa was not detectable in the same assay. More importantly, increased hemostatic activity of FVII-189 was observed by ROTEM in acquired hemophilic monkey blood where factor VIII activity was neutralized by the inhibitory antibodies. We then evaluated FVII-189 in cynomolgus monkeys following a bolus intravenous administration (n=3) at an equal molar dose to the pharmacological dose of rFVIIa (~2 nmol/kg). rFVIIa was included as a comparator. Both FVII-189 and rFVIIa appeared to be well tolerated with no abnormal clinical observations that could be attributed to the dosing. No apparent effects on platelet count in whole blood, as well as other hematology and coagulation parameters except for a temporary decrease in prothrombin time over a few hours, which was an expected pharmacological effect of rFVIIa and FVII-189. Compared to rFVIIa, FVII-189 cleared more rapidly in plasma, and distributed more to the platelets. The half-life of FVII-189 antigen on platelets was found to be several fold longer than that of rFVIIa antigen in plasma, as measured by ELISA of the platelet-rich plasma, or by flow cytometry of platelet-associated FVII-189 antigen. Despite the lower initial recovery and faster clearance of FVII-189 in plasma, directing FVII-189 to platelets resulted in much higher hemostatic activity of the whole blood 5 minute and 1 hour after dosing, as measured by ex vivo ROTEM assay. In conclusion, these results indicate that in cynomolgus monkeys, 1) FVII-189 is safe and does not affect the platelet clearance, 2) FVII-189 protein is targeted to platelets with fast clearance in plasma and prolonged half-life on platelets and 3) FVII-189 could be more efficacious in controlling acute bleeds than rFVIIa. Disclosures Tan: Biogen Idec: Employment, Equity Ownership. Salas:Biogen Idec: Employment, Equity Ownership. Chen:Biogen Idec: Employment, Equity Ownership. Ashworth:Biogen Idec: Employment, Equity Ownership. Smith:Biogen Idec: Employment, Equity Ownership. Kistanova:Biogen Idec: Employment, Equity Ownership. Moore:Biogen Idec: Employment, Equity Ownership. Acosta:Biogen Idec: Employment, Equity Ownership. Kole:Biogen Idec: Employment, Equity Ownership. Light:Biogen Idec: Employment, Equity Ownership. Peters:Biogen Idec: Employment. Jiang:Biogen Idec: Employment, Equity Ownership. more...
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- 2014
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20. The activation function-1 of hepatocyte nuclear factor-4 is an acidic activator that mediates interactions through bulky hydrophobic residues
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Elena KISTANOVA, Helen DELL, Panayota TSANTILI, Eileen FALVEY, Christos CLADARAS, and Margarita HADZOPOULOU-CLADARAS
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Transcriptional Activation ,Recombinant Fusion Proteins ,Molecular Sequence Data ,In Vitro Techniques ,Biochemistry ,Protein Structure, Secondary ,Cell Line ,Electrochemistry ,Animals ,Humans ,Amino Acid Sequence ,Amino Acids ,Molecular Biology ,DNA Primers ,Base Sequence ,Sequence Homology, Amino Acid ,Basic Helix-Loop-Helix Leucine Zipper Transcription Factors ,Cell Biology ,Phosphoproteins ,Protein Structure, Tertiary ,DNA-Binding Proteins ,Hepatocyte Nuclear Factor 4 ,COS Cells ,Mutagenesis, Site-Directed ,Research Article ,Protein Binding ,Transcription Factors - Abstract
The hepatocyte nuclear factor-4 (HNF-4) contains two transcription activation domains. One domain, activation function-1 (AF-1), consists of the extreme N-terminal 24 amino acids and functions as a constitutive autonomous activator of transcription. This short transactivator belongs to the class of acidic activators, and it is predicted to adopt an amphipathic α-helical structure. Transcriptional analysis of sequential point mutations of the negatively charged residues (Asp and Glu) revealed a stepwise decrease in activity, while mutation of all acidic residues resulted in complete loss of transcriptional activity. Mutations of aromatic and hydrophobic amino acids surrounding the negatively charged residues had a much more profound effect than mutations of acidic amino acids, since even a single mutation of these residues resulted in a dramatic decrease in transactivation, thus demonstrating the importance of hydrophobic residues in AF-1 activity. Like other acidic activators, the AF-1 of HNF-4 binds the transcription factor IIB and the TATA-binding protein directly in vitro. In addition, the cAMP-response-element-binding-protein, a transcriptional adapter involved in the transactivation of a plethora of transcription factors, interacts with the AF-1 of HNF-4 and co-operates in the process of transactivation by HNF-4. The different protein targets of AF-1 suggest that the AF-1 of HNF-4 may be involved in recruiting both general transcription factors and chromatin remodelling proteins during activation of gene expression. more...
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- 2001
21. Flowcytometry as a method for advanced evaluation of boar semen
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Hayrabedyan, S., Georgiev, B., Kacheva, D., Chervenkov, M., Shumkov, K., Taushanova, P., and Elena Kistanova
22. Protected fat in the diet of lactating ewes affects milk composition, lamb body weight and their biochemical parameters
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Zdorovieva, E., Boryaev, G., Elena Kistanova, Nosov, A., Fedorov, Y., and Semigodov, N.
23. Tribulus terrestris Alters the Expression of Growth Differentiation Factor 9 and Bone Morphogenetic Protein 15 in Rabbit Ovaries of Mothers and F1 Female Offspring.
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Desislava Abadjieva and Elena Kistanova
24. ULTRASOUND DETECTION OF OVARIAN RESPONSE IN GOAT ASSISTED REPRODUCTION PROCEDURES
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Vince, Silvijo, Grizelj, Juraj, Karadjole, Martina, Đuričić, Dražen, Prvanović, Nikica, Samardžija, Marko, Turmalaj, Luigj, Gjino, Paskal, Folnožić, Ivan, Mitak, Mario, Tariba, Bruna, and Dr. Elena Kistanova more...
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ultrasonic examination ,ovary ,goat ,superovulation ,ovulation ,follicle ,corpus luteum ,ovulatory rate - Abstract
The aim of this research was to establish the importance and accuracy of the ultrasonic examination of donor and recipient goats submitted to superovulation procedures. For this reason, 17 donor goats were systematically examined by ultrasound: 1) to count the preovulatory follicles (≥ 5mm) at oestrus onset ; 2) to confirm the ovulation(s) and 3) the accuracy of the ultrasound examination was measured comparing previously findings with number of corpora lutea (CL) present when uterine flushing was performed. On the other hand, 14 recipient goat ovaries were monitored by ultrasound to assess: 1) the number of dominant follicles (≥ 5mm) present during oestrus ; 2) the ovulation and 3) the echogenic quality of CL before embryotransfer. To perform the ultrasound examination the animals were placed in dorsal recumbence and 7, 5MHz ultrasound probe was applied rectally. To predict the ovulation rate the number of large follicles (≥ 5mm) was counted by ultrasound on donor goat ovaries at the beginning of oestrus. Unovulated follicles (48h after oestrus start) were omitted. The ultrasound accuracy, measured comparing the number of ovulated follicles with number of corpora lutea counted when laparotomic flushing was performed, was 47, 5%. The ovulatory rate prediction is more accurately (72.1%) when donor goat responded with lower total number of follicles (10 or less). The response of 9 out of 14 (64%) recipient goats, after standard hormonal protocol was applied, were adequate, what means maximum 2 dominant follicles, timely occurred ovulation and good echogenic quality of respective CL. The ultrasonic examination of donor and recipient goats is appreciable tool to follow up follicular dynamics, success of superovulation procedures, confirmation of ovulation and echogenic CL quality, as well as to predict the ovulatory rate. In this way the ultrasound examinations of the ovaries could save the time and the money due to elimination of animals who did not respond to the treatment before the collection or transfer of embryos start. more...
- Published
- 2009
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