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  • Author: Bartosz Kempisty x
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Resveratrol and Its Analogues – Is It a New Strategy of Anticancer Therapy?

Summary

Resveratrol (RSV) is one of the polyphenols - metabolites common in plants,however it does not occur in animals. It occurs mainly in grape skin (Vitisvinifera), peanuts (Arachis hypogeal) and in the roots of (Polygonumcupidatum) a traditional Chinese curative plant.

RSV has a preventive property against the most serious diseases of modern world such as cancer, neurodegenerative diseases and cardiovascular diseases. Due to pleiotropy, RSV is currently the main object of many research teams′ interest, which is shown by the significant number of publications devoted to this subject.

Animal and human conducted studies have shown very low bioavailability of RSV (approx. 2%), which is the result of rapid biotransformation to sulphate and to a lesser extent, to the glucuronide conjugates as well. The studies on the improvement of RSV bioavailability, which have beencarried out for many years, have contributed to the synthesis of the analogues of more chemopreventive and more desirable pharmacokinetic properties. In order to enhance antiproliferative activity and RSV bioavailability, series of methyl analogues were synthesized and this will be described later in more detail. An example of such a derivative is DMU-212 (3,4,4’5-tetramethoxystilbene).

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Stemness specificity of epithelial cells – application of cell and tissue technology in regenerative medicine

Abstract

Stem cells are cells that have the potential to replicate and/or differentiate, becoming any tissue. This process could be theoretically repeated indefinitely and can be used to create or fix damaged parts any organ. There are many in vivo factors that cause stem cells to replicate and differentiate. Many of these interactions and mechanisms are still unknown. In vitro models have been successful in inducing stem cells to differentiate into the desired lineage using controlled methods. Recently, epithelial tissue has been successfully created using scaffolds on which stem cells are grown in vitro and then transplanted into the host. This transition creates significant problems. This is because in vitro -grown stem cells or stem cell-derived tissues are created in an isolated environment where virtually every aspect can be monitored and controlled. In vivo monitoring and controlling is significantly more difficult for a plethora of reasons. Cells in the body are constantly exposed to many signals and molecules which affect them. Many of the mechanisms behind these interactions and reactions are known but many others are not. As the corpus of knowledge grows, stem cells become closer to being applied in a clinical setting. In this paper, we review the current evidence on stem cell therapy in regenerative medicine and some of the challenges this field faces.

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Magnetic-Activated Cell Sorting in Combination with Swim-Up Efficiency Improve Effectivity of Spermatozoa Separation

Abstract

Correct selection of spermatozoa before their using for an assisted reproductive techniques is one of the crucial step in therapy of human infertility. It was previously reported that male factor plays a major role in infertility. Basic semen analyses and standard methods for sperm selection in many cases does not eliminate sufficiently proportion of spermatozoa with genetics defects. Magnetic Activated Cell Sorting (MACS) is a selection method which reduce apoptotic sperm and improve sperm and embryo quality. The aim of our study was the comparison of swim-up method and MACS and their combination. We tested swim-up and MACS alone and treatment of spermatozoa in combination when was is first swim-up and second MACS and vice versa. In this study we evaluated sperm concentration, motility and their DNA integrity before and after separtion methods. On the basis of our results we recommend to use swim-up before MACS method. This approach brings better results in the sperm selection - lower proportion of spermatozoa with fragmented DNA and also it brings better gain of total spermatozoa usable for next IVF or ICSI methods.

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Recent Findings of the Types of Programmed Cell Death

Summary

Cell death plays an important role in maintaining the homeostasis of multicellular organisms. It can occur in a controlled manner by apoptosis or autophagy. Cell death which occurs regardless of regulatory factors include necrosis, mitotic catastrophe or oncosis.

Apoptosis and necrosis are cellular process that leads to cell death. However their mechanisms are different, although factors triggering them can be similar. Necrosis and apoptosis have many different characteristics in terms of biochemistry and morphology.

There are two main pathways of apoptosis induction signal: receptor - dependent and mitochondrial. The outsider apoptotic pathway is induced by external factors stimulating membrane receptors having an intracellular domain called death domain.

Mitochondrial apoptotic pathway is activated by increased concentration of reactive oxygen species (ROS), DNA damage, disorders electrolyte transport and an increase in the concentration of the calcium ions in the cytoplasm. In response to stress-factors, mitochondrial channels are opened, so that is released into the cytoplasm cytochrome C. This work is aimed at an overall description of exchanged processes.

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Genes regulating biochemical pathways of oxygen metabolism in porcine oviductal epithelial cells during long-term IVC

Abstract

Oxygen metabolism has an important role in the normal functioning of reproductive system, as well as the pathogenesis of female infertility. Oxidative stress seems to be responsible for the initiation or development of reproductive organ diseases, including polycystic ovary syndrome, endometriosis, preeclampsia, etc. Given the important role of maintaining balance between the production of ROS and antioxidant defence in the proper functioning of reproductive system, in the present study we aimed to analyse the expression of genes related to oxygen metabolism in porcine oviductal epithelial cells during long-term in vitro culture. The oviducts were collected from 45 crossbred gilts at the age of approximately nine months that displayed at least two regular oestrous cycles. The oviductal endothelial cells were isolated by enzymatic digestion to establish long-term primary cultures. Gene expression changes between 7, 15 and 30 daysof culturewere analysed with the use ofwhole transcriptome profiling by Affymetrix microarrays. The most of the “cellular response to oxidative stress” genes were upregulated. However, we did not observe any main trend in changes within the “cellular response to oxygen-containing compound” ontology group, where the gene expression levels were changed in various manner.

Running title: Oxygen metabolism in porcine oviductal epithelial cells

Open access
Genes encoding proteins regulating fatty acid metabolism and cellular response to lipids are differentially expressed in porcine luminal epithelium during long-term culture

Abstract

Among many factors, the epithelium lining the oviductal lumenis very important for the development of the oocyte and its subsequent fertilization. The oviductal epithelium is characterized by the presence of ciliary cells, supporting the movement of cumulus-oocyte complexes towards the uterus. By interacting with the semen, the epithelium of the fallopian tube makes the sperm acquire the ability to fertilize. So far, the exact molecular mechanisms of these changes have not been known. Hence, understanding the metabolism of oviduct epithelial cells and the level of expression of individual groups of genes seems to be a way to deepen the knowledge about the broadly understood reproduction.

In our research, we decided to culture oviductal epithelial cells (OECs) in vitro for a long period of time. After 24h, 7, 15 and 30 days, the OECs were harvested, with their RNA isolated. Transcriptomic changes were analyzed using microarrays. The “cellular response to lipid” group was represented by the following genes: MUC1, CYP24A1, KLF4, IL24, SNAI2, CXCL10, PPARD, TNC, ABCA10, while the genes belonging to the “cellular lipid metabolic processes” were: LIPG, ARSK, ACADL, FADS3, P2RX7, ACSS2, PPARD, KITLG, SPTLC3, ERBB3, KLF4, CRABP2. Additionally, PPARD and ACADL were members of the “fatty acid beta-oxidation” ontology group. Our study describes genes that are not directly related to fertility processes. However, significant changes in their expression in in vitro cultured OECs may indicate their usefulness as markers of OECs’ physiological processes.

Running title: Fatty acids changes in porcine oviductal epithelial cells in in vitro cultivation

Open access
Transforming growth factor (TGF) – is it a key protein in mammalian reproductive biology?

Abstract

The superfamily of transforming growth factors β (TGF-β) consists of cytokines that are crucial in regulating the organism’s biological functions and includes three isoforms of TGF-β protein, Anti-Müllerian Hormone (AMH), inhibin A and B, activins, 20 bone morphogenetic proteins (BMP1-20) and 9 growth factors (GDF1-9). Their signal transduction pathway involves three types of membrane receptors that exhibit a serine/threonine kinase activity, as well as the Smad proteins. After ligand binding, the Smad proteins are phosphorylated and translocated to the nucleus, where they interact with transcription factors and affect gene expression. TGF-β family members are involved in cell growth and differentiation, as well as chemo-taxis and apoptosis, and play an important role during an inflammation. Defects in TGF-β proteins or in their signalling pathway underlie many severe diseases, such as systemic lupus, systemic scleroderma, bronchial asthma, atherosclerosis, hyperthyroidism or cancer. These factors are also crucial in mammal reproductive functions, as they are involved in folliculogenesis, steroidogenesis, ovulation, maternal-embryo interaction, embryo development and uterine decidualization. Their defects result in issues with fertility. This review focuses on the relevance of TGF-β family members in a mammal reproduction with an emphasis on three TGF-β isoforms, inhibins A and B, GDF-9 and their signal transduction pathway.

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Characteristic of factors influencing the proper course of folliculogenesis in mammals

Abstract

Folliculogenesis is the process of ovarian follicle formation,, taking presence during foetal period. During the follicular development, oogoniums undergo meiosis and oocytes are formed. In the ovaries of new born sows, primary and secondary follicles are present and, 90 days after birth, tertiary follicles appear. During development in the ovarian follicles growth of granulosa cells and differentiation of the thecal cells can be observed. A cavity filled with follicular fluid appears. Granulosa cells are divided into: mural cells and corona radiata, which together with the oocyte form the cumulus oophorus. Corona radiata cells, mural layers and oolemma contact each other by a network of gap junctions. Secreted from the pituitary gland, FSH and LH gonadotropin hormones act on receptors located in granular and follicular cells. In the postnatal life tertiary follicles and Graafian follicles are formed. When the follicle reaches a diameter of 1 mm, further growth depends on the secretion of gonadotropins. Mature ovarian follicles produce: progestins, androgens and oestrogens. The growth, differentiation and steroidogenic activity of ovarian follicles, in addition to FSH and LH, is also affected by prolactin, oxytocin, steroid and protein hormones, numerous proteins from the cytokine and interleukin family, metabolic hormones like insulin, glucocorticoids, leptin, thyroid hormones and growth hormones. Despite numerous studies, many processes related to folliculogenesis have not been discovered Learning the mechanisms regulating reproductive processes would allow to easily distinguish pathological processes and discover more and more genes and mechanisms of their expression in cells that build ovarian follicles.

Open access
Pathogenesis and pathophysiology of ovarian follicular cysts in mammals

Abstract

Ovarian cysts remain to be one of the most common and serious problems in reproduction of farm animals, as well as humans. Apart from causing the fall in reproductive potential of the ovaries, occupying the place in which folliculogenesis and oogenesis occur, they also cause hormone imbalances, by preventing corpus luteum formation, hence lowering the amount of steroid hormone production. While singular cysts rarely affect fertility, hormone fluctuations that are associated with their presence promotes their multiplication, which usually has more adverse effects. While the cysts are easily detectable in humans, possessing distinct echography while examined by ultrasound, multiple factors prevent widespread use of effective detection methods among large herds of farm animals. Because of lack of noticeable symptoms of early stages of such malignancies, they rarely get detected before the animal stops to exhibit symptoms of heat. That causes scientific research to be focused on not only methods of detection, but also the ways to negate the effects of ovarian cysts and bring the affected specimen back to reproductive potential. Despite that, high costs of diagnosis and treatment, cause them to be uncommon on commercial farms. As lack of fertility eliminates animals from breeding purposed herds, ovarian cysts persist as a cause of large losses of the animal husbandry business. Continuous research, focused on natural examples of ovarian cysts should be conducted, in order to improve methods of detection, prevention, treatment and recovery from the effects of ovarian cysts.

Open access
Current Topics in Assisted Reproduction in the Czech Republic

Abstract

Assisted reproduction is a very dynamic part of reproductive gynaecology with fast changes in therapeutic approaches resulting from intensive research supported by private or public companies. This progress brings also new questions regarding ethical, legal or therapeutic issues. At the 26th Czech-Slovak symposium of assisted reproduction in Brno, several interesting topics of assisted reproduction were presented. During two days, more than 350 specialists discussed current topics related to gynaecology, embryology, andrology, genetics and sexology. From this fruitful discussion we chose the following topics that we consider to be the most important: (1) “Soft” versus “standard” stimulation protocols for IVF (2) Use of exogenous and endogenous progestins in IVF stimulation protocols (3) Cryopreservation and transplantation of ovarian tissue - state of the art and situation in the Czech Republic (4) Selection of spermatozoa with fragmented DNA: practical recommendations (5) Artificial activation of oocytes (8) Access of single and lesbian women to assisted reproduction technologies and possibility of their reproduction in the Czech Republic. Panel conclusions were presented at the end of the conference, which had great attendance, invoked lively commentaries and produced some definitive consensus. Certain issues remained inconclusive and these matters will be the subject of further discussion in future. This is a summary of the most important theses from this field in the Czech Republic in 2017.

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