Vol. 17 No. 3 September 2012
DOI: 10.2478/s11658-012-0013-8 Volume 17 (2012) pp 323-332 | |
Title | SODIUM NITROPRUSSIDE, A NITRIC OXIDE DONOR, FAILS TO BYPASS THE BLOCK OF NEURONAL DIFFERENTIATION IN PC12 CELLS IMPOSED BY A DOMINANT NEGATIVE Ras PROTEIN |
Authors | Judit Bator1, Judit Varga1, Gergely Berta1, Tamar Barbakadze2, David Mikeladze2, Jeremy Ramsden3 and József Szeberenyi1* |
Abstract | Nitric oxide (NO) is a mediator of a diverse array of inter- and intracellular signal transduction processes. The aim of the present study was to analyze its possible role as a second messenger in the process of neuronal differentiation of PC12 pheochromocytoma cells. Upon NGF treatment wildtype PC12 cells stop dividing and develop neurites. In contrast, a PC12 subclone (designated M-M17-26) expressing a dominant-negative mutant Ras protein keeps proliferating and fails to grow neurites after NGF treatment. Sodium nitroprusside (SNP), an NO donor, was found to induce the p53 protein and to inhibit proliferation of both PC12 and M-M17-26 cells, but failed to induce neuronal differentiation in these cell lines. Key signaling pathways (the ERK and Akt pathways) were also not affected by SNP treatment, and the phosphorylation of CREB transcription factor was only slightly stimulated. It is thus concluded from the results presented in this paper that NO is unable to activate signaling proteins acting downstream or independent of Ras that are required for neuronal differentiation. |
Keywords | Nitric oxide, Sodium nitroprusside, PC12 cells, Nerve growth factor, Neuronal differentiation, Dominant inhibitory Ras protein, p53 protein, ERK proteins, Akt protein, CREB protein |
Address and Contact Information | 1Department of Medical Biology, Medical School, University of Pécs,
7624 Pécs, Szigeti u. 12, Hungary, 2Ilia State University, Tbilisi, Georgia, 3Collegium Basilea, Institute of Advanced Study, Basel, Switzerland * Author for correspondence. e-mail address: jozsef.szeberenyi@aok.pte.hu, tel.: 36-72- 536-216, fax: 36-72-536-453 |
DOI: 10.2478/s11658-012-0014-7 Volume 17 (2012) pp 333-348 | |
Title | STABILIZATION OF ERYTHROCYTES AGAINST OXIDATIVE AND HYPOTONIC STRESS BY TANNINS ISOLATED FROM SUMAC LEAVES (Rhus typhina L.) AND GRAPE SEEDS (Vitis vinifera L.)# |
Authors | Ewa Olchowik1, Karol Lotkowski1, Saidmukhtar Mavlyanov2, Nodira Abdullajanova2, Maksim Ionov3, Maria Bryszewska3 and Maria Zamaraeva1* |
Abstract | Erythrocytes are constantly exposed to ROS due to their function in the organism. High tension of oxygen, presence of hemoglobin iron and high concentration of polyunsaturated fatty acids in membrane make erythrocytes especially susceptible to oxidative stress. A comparison of the antioxidant activities of polyphenol-rich plant extracts containing hydrolysable tannins from sumac leaves (Rhus typhina L.) and condensed tannins from grape seeds (Vitis vinifera L.) showed that at the 5-50 µg/ml concentration range they reduced to the same extent hemolysis and glutathione, lipid and hemoglobin oxidation induced by erythrocyte treatment with 400 µM ONOO- or 1 mM HClO. However, extract (condensed tannins) from grape seeds in comparison with extract (hydrolysable tannins) from sumac leaves stabilized erythrocytes in hypotonic NaCl solutions weakly. Our data indicate that both hydrolysable and condensed tannins significantly decrease the fluidity of the surface of erythrocyte membranes but the effect of hydrolysable ones was more profound. In conclusion, our results indicate that extracts from sumac leaves (hydrolysable tannins) and grape seeds (condensed tannins) are very effective protectors against oxidative damage in erythrocytes. |
Keywords | Tannins, Erythrocytes, Oxidative stress, Peroxynitrite, Hypochlorous acid, Hemolysis, Fluorescence anisotropy |
Address and Contact Information | 1Department of Biophysics, University of Białystok, ¦wierkowa 20B, 15-950
Białystok, Poland, 2Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Abdullaev 83, Tashkent, 100125, Uzbekistan, 3Department of General Biophysics, University of ŁódĄ, Banacha 12/16, 90-237 ŁódĄ, Poland # Paper authored by participant of the international conference: 18th Meeting, European Association for Red Cell Research, Wrocław – Piechowice, Poland, May 12-15th, 2011. Publication cost was covered by the organizers of this meeting. * Author for correspondence. e-mail: m.zamaraeva@uwb.edu.pl, tel. +48 85 745 7349 |
DOI: 10.2478/s11658-012-0015-6 Volume 17 (2012) pp 349-375 | |
Title | MODULATION OF PHYSIOLOGICAL AND PATHOLOGICAL ACTIVITIES OF LYSOZYME BY BIOLOGICAL MEMBRANES |
Authors | Valeriya Trusova |
Abstract | The molecular details of interactions between lipid membranes and lysozyme (Lz), a small polycationic protein with a wide range of biological activities, have long been the focus of numerous studies. The biological consequences of this process are considered to embrace at least two aspects: i) correlation between antimicrobial and membranotropic properties of this protein, and ii) lipid-mediated Lz amyloidogenesis. The mechanisms underlying the lipid-assisted protein fibrillogenesis and membrane disruption exerted by Lz in bacterial cells are believed to be similar. The present investigation was undertaken to gain further insight into Lz-lipid interactions and explore the routes by which Lz exerts its antimicrobial and amyloidogenic actions. Binding and Förster resonance energy transfer studies revealed that upon increasing the content of anionic lipids in lipid vesicles, Lz forms aggregates in a membrane environment. Total internal reflection fluorescence microscopy and pyrene excimerization reaction were employed to study the effect of Lz on the structural and dynamic properties of lipid bilayers. It was found that Lz induces lipid demixing and reduction of bilayer free volume, the magnitude of this effect being much more pronounced for oligomeric protein. |
Keywords | Amyloid toxicity, Antimicrobial activity, “Carpet” mechanism, Fluorescence spectroscopy, Lipid membranes, Lipid domain formation, Lysozyme, Membrane free volume, Membrane destabilization, Protein aggregation |
Address and Contact Information | Department of Biological and Medical Physics, V. N. Karazin Kharkov National
University, 4 Svobody Sq., Kharkov 61077, Ukraine * Address for correspondence: Valeriya Trusova, 19-32 Geroyev Truda St., Kharkov 61144, Ukraine. E-mail: valtrusova@yahoo.com |
DOI: 10.2478/s11658-012-0016-5 Volume 17 (2012) pp 376-392 | |
Title | HUMAN ADIPOSE-DERIVED STEM CELLS FOR THE TREATMENT OF INTRACEREBRAL HEMORRHAGE IN RATS VIA FEMORAL INTRAVENOUS INJECTION |
Authors | Kuo-Liang Yang1,2*, Jiunn-Tat Lee3, Cheng-Yoong Pang4,5, Ting-Yi Lee1, Shee-Ping Chen1, Hock-Kean Liew4, Shin-Yuan Chen6, Tzu-Yung Chen7 and Py-Yu Lin1 |
Abstract | Human adipose-derived stem cells (huADSC) were generated from fat tissue of a 65-year-old male donor. Flow cytometry and reverse transcription polymerase chain reaction (RT-PCR) analyses indicated that the huADSC express neural cell proteins (MAP2, GFAP, nestin and ß-III tubulin), neurotrophic growth factors (BDNF and GDNF), and the chemotactic factor CXCR4 and its corresponding ligand CXCL12. In addition, huADSC expressed the characteristic mesenchymal stem cell (MSC) markers CD29, CD44, CD73, CD90, CD105 and HLA class I. The huADSC were employed, via a right femoral vein injection, to treat rats inflicted with experimental intracerebral hemorrhage (ICH). Behavioral measurement on the experimental animals, seven days after the huADSC therapy, showed a significant functional improvement in the rats with stem cell therapy in comparison with rats of the control group without the stem cell therapy. The injected huADSC were detectable in the brains of the huADSC treated rats as determined by histochemistry analysis, suggesting a role of the infused huADSC in facilitating functional recovery of the experimental animals with ICH induced stroke. |
Keywords | Adipose-derived stem cells, Adult stem cells, Adipose tissue, Intracerebral hemorrhage, Intravenous stem cell injection, Neural stem cells, Regenerative medicine, Stem cell therapy, Stroke, Stromal cells |
Address and Contact Information | 1Buddhist Tzu Chi Stem Cells Center, Buddhist Tzu Chi Medical Center, Buddhist
Compassion Relief Tzu Chi Foundation, Hualien, Taiwan, 2Institute of Medical Biotechnology, Buddhist Tzu Chi University, Buddhist Compassion Relief Tzu Chi Foundation, Hualien, Taiwan, 3Division of Plastic Surgery, Department of Surgery, Buddhist Tzu Chi Medical Center and Buddhist Tzu Chi University, Buddhist Compassion Relief Tzu Chi Foundation, Hualien, Taiwan, 4Department of Research, Buddhist Tzu Chi Medical Center, Buddhist Compassion Relief Tzu Chi Foundation, Hualien, Taiwan, 5Graduate Institute of Clinical Medicine, Buddhist Tzu Chi University, Buddhist Compassion Relief Tzu Chi Foundation, Hualien, Taiwan, 6Division of Functional Neuroscience, Department of Neurosurgery, Neuro-Medical Scientific Center, Buddhist Tzu Chi Medical Center, Buddhist Compassion Relief Tzu Chi Foundation, Hualien, Taiwan, 7Department of Neurosurgery, Buddhist Tzu Chi Medical Center Taichung Branch, Buddhist Compassion Relief Tzu Chi Foundation, Taichung, Taiwan * Author for correspondence. e-mail: edward@tzuchi.com.tw, asdinap@yahoo.com.tw, tel.: +886-03-8561825#3373 |
DOI: 10.2478/s11658-012-0017-4 Volume 17 (2012) pp 393-407 | |
Title | PHYLOGENETIC ORIGIN AND TRANSCRIPTIONAL REGULATION AT THE POST-DIAUXIC PHASE OF SPI1 IN Saccharomyces cerevisiae |
Authors | Fernando Cardona1,2*, Marcel.Li Del Olmo2 and Agustin Aranda1 |
Abstract | The gene SPI1 of Saccharomyces cerevisiae encodes a cell wall protein that is induced in several stress conditions, particularly in the postdiauxic and stationary phases of growth. It has a paralogue, SED1, which shows some common features in expression regulation and in the null mutant phenotype. In this work we have identified homologues in other species of yeasts and filamentous fungi, and we have also elucidated some aspects of the origin of SPI1 by duplication and diversification of SED1. In terms of regulation, we have found that the expression in the post-diauxic phase is regulated by genes related to the PKA pathway and stress response (MSN2/4, YAK1, POP2, SOK2, PHD1 and PHO84) and by genes involved in the PKC pathway (WSC2, PKC1 and MPK1). |
Keywords | SPI1, Phylogenetic origin, Transcriptional regulation, Post-diauxic, Nutrient starvation, PKA, PKC |
Address and Contact Information | 1Departamento de Biotecnología, Instituto de Agroquímica y Tecnología
de Alimentos, CSIC, Paterna, Spain, 2Departament de Bioquímica i Biologia Molecular, Universitat de Valencia, Burjassot, Spain * Author for correspondence. Current address: Unitat de Genetica Molecular, Institut de Biomedicina de Valencia, CSIC, C/ Jaume Roig 11, E46010, Valencia, Spain. e-mail: fcardona@ibv.csic.es, tel.: +34963391756, fax: +34963393744 |
DOI: 10.2478/s11658-012-0018-3 Volume 17 (2012) pp 408-421 | |
Title | SYNERGISTIC EFFECTS OF AMYLOID PEPTIDES AND LEAD ON HUMAN NEUROBLASTOMA CELLS |
Authors | Challa Suresh1,2, Johnny Johnson1, Roshini Mohan1 and Chellu S. Chetty1* |
Abstract | Aggregated amyloid peptides (AP), major components of senile plaques, have been considered to play a very important and crucial role in the development and neuro-pathogenesis of Alzheimer’s disease (AD). In the present in vitro study the synergistic effects of Pb2+, a heavy metal, and AP on the human neuroblastoma SH-SY5Y cells were investigated. The cells treated with Pb2+ (0.01-10 µM) alone exhibited a significant decrease in viability and IC50 was 5 µM. A similar decrease in viability was also observed when the cells were exposed to AP, Aß1-40 (20-120 µM) and Aß25-35 (2.5-15 µM) for 48 hrs. The IC50 values were 60 µM and 7.5 µM for Aß1-40 and Aß25-35 respectively. To assess the synergistic effects the cells were exposed to IC50 of both AP and Pb2+, which resulted in further reduction of the viability. The study was extended to determine the lactate dehydrogenase (LDH) release to assess the cytotoxic effects, 8-isoprostane for extent of oxidative damage, COX 1 and 2 for inflammation related changes, p53 protein for DNA damage and protein kinases A and C for signal transduction. The data suggest that the toxic effects of AP were most potent in the presence of Pb2+, resulting in an aggravated clinical pathological condition. This could be attributed to the oxidative stress, inflammation neuronal apoptosis and an alteration in the activities of the signaling enzymes. |
Keywords | Amyloid peptides, Lead, LDH, Oxidative stress, Inflammation, Neuronal apoptosis, Signaling |
Address and Contact Information | 1Department of Natural Sciences, Savannah State University, Savannah,
GA 31404, USA, 2Department of Biochemistry, National Institute of Nutrition, Hyderabad-500007, AP, India * Author for correspondence. e-mail: chettyc@savannahstate.edu, tel.: 912-358-4277, fax: 912- 353-3093/912-358-4780 |
DOI: 10.2478/s11658-012-0020-9 Volume 17 (2012) pp 422-432 | |
Title | SHP-2 AND PTP-PEST INDUCTION DURING Rb-E2F ASSOCIATED APOPTOSIS |
Authors | Liza D. Morales1,3, Karina Pena1, Dae Joon Kim2,3 and Jonathan H. Lieman1* |
Abstract | Apoptosis is intimately connected to cell cycle regulation via the Retinoblastoma (Rb)-E2F pathway and thereby serves an essential role in tumor suppression by eliminating aberrant hyperproliferative cells. Upon loss of Rb activity, an apoptotic response can be elicited through both p53-dependent and p53-independent mechanisms. While much of this apoptotic response has been attributed to the p19ARF/ p53 pathway, increasing evidence has supported the role of protein tyrosine phosphatases (PTPs) in contributing to the initiation of the Rb-E2F-associated apoptotic response. One protein tyrosine phosphatase, PTP-1B, which is induced by the Rb-E2F pathway, has been shown to contribute to a p53-independent apoptotic pathway by inactivating focal adhesion kinase. This report identifies two additional PTPs, SHP-2 and PTP-PEST, that are also directly activated by the Rb-E2F pathway and which can contribute to signal transduction during p53-independent apoptosis. |
Keywords | Apoptosis, Focal adhesion kinase, Rb, E2F-1, Phosphatase, PTP-1B, SHP-2, PTP-PEST, PTPN1, PTPN11, PTPN12, Tumor suppressor |
Address and Contact Information | 1Department of Biology, The University of Texas-Pan American, Edinburg,
TX,USA, 2Department of Pharmacology and 3Edinburg Regional Academic Health Center, Medical Research Division, University of Texas Health Science Center at San Antonio, Edinburg, TX, USA * Author for correspondence. e-mail: jlieman@utpa.edu, tel.: 956-665-3656, fax: 956- 665-3657 |
DOI: 10.2478/s11658-012-0022-7 Volume 17 (2012) pp 433-445 | |
Title | De novo SYNTHESIS OF PROTEIN PHOSPHATASE 1A, MAGNESIUM DEPENDENT, ALPHA ISOFORM (PPM1A) DURING OOCYTE MATURATION |
Authors | Dana Chuderland1§, Zeev Dvashi2§, Ruth Kaplan-Kraicer1, Daniella Ben-Meir2, Ruth Shalgi1* and Sara Lavi2 |
Abstract | Oocyte maturation in mammals is a multiple-stage process that generates fertilizable oocytes. Ovarian oocytes are arrested at prophase of the first meiotic division characterized by the presence of a germinal vesicle. Towards ovulation, the oocytes resume meiosis and proceed to the second metaphase in a process known as maturation; they undergo nuclear and cytoplasmic changes that are accompanied by translation and degradation of mRNA. Protein phosphatase 1A, magnesium dependent, alpha isoform (PPM1A), which belongs to the metal-dependent serine/threonine protein phosphatase family, is highly conserved during evolution. PPM1A plays a significant role in many cellular functions such as cell cycle progression, apoptosis and cellular differentiation. It works through diverse signaling pathways, including p38 MAP kinase JNK and transforming growth factor beta (TGF-ß). Herein we report that PPM1A is expressed in mouse oocytes and that its mRNA level rises during oocyte maturation. Using quantitative real-time polymerase chain reaction (qPCR) and western blot analysis, we found that PPM1A mRNA is synthesized at the beginning of the maturation process and remains elevated in the mature oocytes, promoting the accumulation of PPM1A protein. Since PPM1A function is mainly affected by its level, we propose that it might have an important role in oocyte maturation. |
Keywords | GV, MII, Transcription, Signal transduction, Phosphatase, P38-MAPK, Oocyte, Ovary, PPM1A, Maturation |
Address and Contact Information | 1Department of Cell and Developmental Biology, Sackler Faculty of Medicine, 2Cell Research and Immunology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel § Both authors contributed equally to the work * Author for correspondence. e-mail: shalgir@post.tau.ac.il, tel.: +972-3-6408685, fax: +972- 3-6407432 |
DOI: 10.2478/s11658-012-0021-8 Volume 17 (2012) pp 446-458 | |
Title | ALTERATIONS OF THE Hsp70/Hsp90 CHAPERONE AND THE HOP/CHIP CO-CHAPERONE SYSTEM IN CANCER |
Authors | Eva Ruckova, Petr Muller, Rudolf Nenutil and Borivoj Vojtesek* |
Abstract | Activation of the Hsp90 chaperone system is a characteristic of cancer cells. The regulation of chaperone activities involves their interaction with cochaperones; therefore we investigated the expression of Hsp70 and Hsp90 and their specific co-chaperones HOP and CHIP in cancer cell lines and primary cancers. Inhibition of Hsp90 by 17AAG increased the levels of Hsp70, Hsp90 and HOP but not CHIP mRNA in cancer cells. These changes are linked to activation of the HSF1 transcription factor and we show that the HOP promoter contains HSF1 binding sites, and that HSF1 binding to the HOP promoter is increased following 17AAG. The lack of alteration in the co-chaperone CHIP is explained by a lack of HSF response elements in the CHIP promoter. Nonproliferating cells expressed higher levels of CHIP and lower HOP, Hsp70 and Hsp90 levels compared to proliferating cells. Decreased expression of CHIP in proliferating cancer cells is in keeping with its proposed tumor suppressor properties, while over-expression of HOP in proliferating cells may contribute to excessive Hsp90 activity and stabilization of client proteins in tumors. In a panel of colorectal cancer samples, increased expression of Hsp70 and an increased ratio of HOP to CHIP were found, and were associated with decreased median survival. These data indicate that multiple changes occur in the chaperone/cochaperone system in cancer that impact patient survival. It is likely that the ability to identify individual alterations to this system will be beneficial for treatment strategy decisions, particularly those that employ chaperone inhibitors. |
Keywords | Chaperone, Co-chaperone, Cancer, Hsp90, Hsp70, HOP, CHIP, HSF1, 17AAG |
Address and Contact Information | Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer
Institute, Zluty kopec 7, Brno 656 53, Czech Republic * Author for correspondence. e-mail: vojtesek@mou.cz, tel.: +4205 4313 3303, fax: +4205 4321 1169 |
DOI: 10.2478/s11658-012-0019-2 Volume 17 (2012) pp459-478 | |
Title | DIFFERENCES BETWEEN GROUP X AND GROUP V SECRETORY PHOSPHOLIPASE A2 IN LIPOLYTIC MODIFICATION OF LIPOPROTEINS |
Authors | Shigeki Kamitani1,2,*, Katsutoshi Yamada2, Shigenori Yamamoto2, Yoshikazu Ishimoto2, Takashi Ono2, Akihiko Saiga2 and Kohji Hanasaki2 |
Abstract | Secretory phospholipases A2 (sPLA2s) are a diverse family of low molecular mass enzymes (13-18 kDa) that hydrolyze the sn-2 fatty acid ester bond of glycerophospholipids to produce free fatty acids and lysophospholipids. We have previously shown that group X sPLA2 (sPLA2-X) had a strong hydrolyzing activity toward phosphatidylcholine in low-density lipoprotein (LDL) linked to the formation of lipid droplets in the cytoplasm of macrophages. Here, we show that group V sPLA2 (sPLA2-V) can also cause the lipolysis of LDL, but its action differs remarkably from that of sPLA2-X in several respects. Although sPLA2-V released almost the same amount of fatty acids from LDL, it released more linoleic acid and less arachidonic acid than sPLA2-X. In addition, the requirement of Ca2+ for the lipolysis of LDL was about 10-fold higher for sPLA2-V than sPLA2-X. In fact, the release of fatty acids from human serum was hardly detectable upon incubation with sPLA2-V in the presence of sodium citrate, which contrasted with the potent response to sPLA2-X. Moreover, sPLA2-X, but not sPLA2-V, was found to specifically interact with LDL among the serum proteins, as assessed by gel-filtration chromatography as well as sandwich enzyme-immunosorbent assay using anti-sPLA2-X and anti-apoB antibodies. Surface plasmon resonance studies have revealed that sPLA2-X can bind to LDL with high-affinity (Kd = 3.1 nM) in the presence of Ca2+. Selective interaction of sPLA2-X with LDL might be involved in the efficient hydrolysis of cell surface or intracellular phospholipids during foam cell formation. |
Keywords | Secretory phospholipase A2, Low-density lipoprotein, High-density lipoprotein, Phospholipids, Calcium ion |
Address and Contact Information | 1Department of Molecular Bacteriology, RIMD, Osaka University, 3-1,
Yamada-oka, Suita-shi, Osaka 565-0871, Japan, 2Shionogi Research Laboratories, Shionogi & Co., Ltd., 3-1-1, Futaba-cho, Toyonaka, Osaka 561-0825, Japan * Author for correspondence. e-mail: skami@biken.osaka-u.ac.jp, tel.: +81-6-6879-8285, fax: +81-6-6879-8283 |
DOI: 10.2478/s11658-012-0023-6 Volume 17 (2012) pp 479-499 | |
Title | CANNABINOID-LIKE ANTI-INFLAMMATORY COMPOUNDS FROM FLAX FIBER |
Authors | Monika Styrczewska1§, Anna Kulma1§*, Katarzyna Ratajczak2, Ryszard Amarowicz3 and Jan Szopa1 |
Abstract | Flax is a valuable source of fibers, linseed and oil. The compounds of the latter two products have already been widely examined and have been proven to possess many health-beneficial properties. In the course of analysis of fibers extract from previously generated transgenic plants overproducing phenylpropanoids a new terpenoid compound was discovered. The UV spectra and the retention time in UPLC analysis of this new compound reveal similarity to a cannabinoid-like compound, probably cannabidiol (CBD). This was confirmed by finding two ions at m/z 174.1 and 231.2 in mass spectra analysis. Further confirmation of the nature of the compound was based on a biological activity assay. It was found that the compound affects the expression of genes involved in inflammatory processes in mouse and human fibroblasts and likely the CBD from Cannabis sativa activates the specific peripheral cannabinoid receptor 2 (CB2) gene expression. Besides fibers, the compound was also found in all other flax tissues. It should be pointed out that the industrial process of fabric production does not affect CBD activity. The presented data suggest for the first time that flax products can be a source of biologically active cannabinoid-like compounds that are able to influence the cell immunological response. These findings might open up many new applications for medical flax products, especially for the fabric as a material for wound dressing with anti-inflammatory properties. |
Keywords | Flax, Linum usitatissimum, Linen, Cannabinoid, Inflammation, Terpenoids, Flax fibers, Cannabinoid signaling |
Address and Contact Information | 1Faculty of Biotechnology, University of Wrocław, Przybyszewskiego 63/77,
51-148 Wrocław, Poland, 2Department of Traumatology and Hand Surgery, Wrocław Medical University, Borowska 213, 50-556 Wrocław, Poland, 3Division of Food Science, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima 10, 10-747 Olsztyn, Poland §These authors contributed equally to this work *Author for correspondence. e-mail: kulma@ibmb.uni.wroc.pl, tel.: +48713756326, fax: +48713252930 |