Search Results

1 - 6 of 6 items

  • Author: Marie Machatkova x
Clear All Modify Search
Ovarian follicular cells - living in the shadow of stemness cellular competence

Abstract

Granulosa cells (GCs) are a major component found in ovarian follicular fluid among oocytes, theca cells, and ovarian surface epithelial (OSE) cells. GCs are steroidogenic and have morphological functions that are important for the development of the follicular follicle. The follicle protects the developing female egg. GCs are also essential for the maturation of the female germ cell. Stem cell properties have been found in luteinised GCs and in vivo cultures have the potential to differentiate to become cells found outside of the ovary. Both three-dimensional (3D) culturing and mouse embryonic fibroblast (MEF) medium have been used to help improve the culturing lifespan of GCs so that their profound proliferation and differentiation capabilities can be studied. Small RNAs called MicroRNAs (miRNAs) are released from exosomes originating from GCs, and they are involved in transforming growth factor (TGF)-β signalling, follicle-stimulating hormone, hormone-related miRNAs, and apoptosis-related pathway. Finding the miRNAs involved in these pathways, and the mechanisms controlling GCs are important to treating conditions like polycystic ovary syndrome (PCOS), and creating new drug therapies. Besides GCs, ovarian stem cells (OSCs) were discovered in the OSE, and they are believed to be derived from very small embryonic stem cells (VSELs). Transplanting blood mononuclear cells, cell Hormone Therapy (cHT) with bone marrow stem cell supplement and increasing vitamin C levels are all therapies currently being researched into that involve GCs to combat the effects of aging and infertility.

Running title: Stemness of ovarian follicular cells

Open access
Analysis of expression of genes responsible for regulation of cellular proliferation and migration – microarray approach based on porcine oocyte model

Abstract

The formation of mammalian oocytes begins in the ovary during fetal development. The proper development of oocytes requires close communication with surrounding somatic cells, the substances they emit allow proper maturation of oocytes. Somatic cumulus (CC) cells and oocytes form cumulus-oocyte (COC) complexes.

In this study, the Affymetrix microarray analysis was used to investigate changes in gene expression occurring in oocytes before and after in vitro maturation (IVM). The aim of the study was to examine oocyte genes involved in two ontological groups, “regulation of cell migration” and “regulation of cell proliferation” discovered by the microarray method.

We found a reduced expression of all 28 genes tested in the ontological groups: ID2, VEGFA, BTG2, CCND2, EDNRA, TGFBR3, GJA, LAMA2, RTN4, CDK6, IHH, MAGED1, INSR, CD9, PTGES, TXNIP, ITGB1, SMAD4, MAP3K1, NOTCH2 , IGFBP7, KLF10, KIT, TPM1, PLD1, BTG3, CD47 and MITF. We chose the most regulated genes down the IVM culture, and pointed out those belonging to two ontological groups.

Increased expression of the described genes before IVM maturation may indicate the important role of these genes in the process of ovum maturation. After the maturation process, the proteins produced by them did not play such an important role. In summary, the study provides us with many genes that can serve as molecular markers of oocyte processes associated with in vitro maturation. This knowledge can be used for detailed studies on the regulation of oocyte maturation processes.

Running title: Genes regulating cellular migration and proliferation in porcine oocytes

Open access
Differential expression pattern of genes involved in oxygen metabolism in epithelial oviductal cells during primary in vitro culture

Abstract

Oxygen metabolism is crucial in establishing successful pregnancy, since excessive amount of reactive oxygen species (ROS) may exert deleterious effects on the developing embryo. There are several defense mechanisms against oxidative stress in the female reproductive tract, including production of antioxidant enzymes by oviductal epithelial cells (OECs). Undoubtedly, OECs play major part in female fertility and may also serve as an in vitro model of the oviduct. Therefore, the aim of this study was to investigate the expression of genes involved in oxygen metabolism. We have isolated OECs from oviducts of crossbred gilts (n=45) and maintained their in vitro culture for 30 days, collecting their RNA at days 1, 7, 15 and 30. The gene expression was determined with the use of Affymetrix® Porcine Gene 1.1 ST Array Strip. Our results revealed 166 differentially expressed genes belonging to four ontology groups: „cellular response to oxidative stress”, “cellular response to oxygen-containing compound”, “cellular response to oxygen levels” and “cellular response to reactive oxygen species”, most of which are also involved in other major processes in the organism. However, our findings provide a valuable insight into porcine reproductive biology and may be utilized in optimization of assisted reproduction techniques.

Running title: Genes involved in oxygen metabolism in oviductal epithelial cells

Open access
Genes regulating programmed cell death are significantly upregulated in porcine immature oocytes

Abstract

Correct maturation of the oocyte is crucial for further fertilization and embryogenesis. It comprises of both nuclear and cytoplasmic maturation, during which the proteins, nutrients and mRNAs are assembled. Cumulus cells are connected with the oocyte via gap-junctions, which enable bi-directional transfer of molecules, forming cumulus-oocyte complex (COC). The expression pattern in CCs is thought to resemble the genes expressed in the oocyte. The CCs surrounding the gamete of high developmental competence have an increased expression of apoptotic markers. Therefore, our aim in this study was to determine whether any apoptosis-related genes are upregulated in porcine oocytes before or after IVM. We isolated COCs from 45 pubertal crossbred gilts, performed brilliant cresyl blue (BCB) staining and analyzed the gene expression pattern in oocytes before and after IVM with the use of microarray analysis. The results include 419 differentially expressed transcripts, 25 of which belong to „regulation of apoptosis” and „regulation of cell death” GO BP terms. This set of genes includes BCLAF1, EIF2AK3, KLF10, MIF, MAP3K1, NOTCH2, TXNIP and APP, all of which have been upregulated in immature porcine oocytes. Our results suggest that they play part in porcine oocyte maturation and could be used as potential markers of female gamete’s developmental competence. This knowledge could serve as a basis to improve ART in pigs.

Open access
The differentiation and transdifferentiation of epithelial cells in vitro – is it a new strategy in regenerative biomedicine?

Abstract

In modern medical research, stem cells are one of the main focuses, believed to be able to provide the solution to many currently unsolvable medical cases. However, their extraordinary potential for differentiation creates much obstacles in their potential application in clinical environment, without understanding the whole array of molecular mechanisms that drive the processes associated with their development and maturation. Because of that, there is a large need for studies that concern the most basic levels of those processes. Progenitor stem cells are a favorable target, as they are relatively lineage committed, making the amount of signaling required to reach the final form much lower. Their presence in the adult organism is also an advantage in their potential use, as they can be extracted without the need for storage from the moment of pre-natal development or birth. Epithelial tissues, because of their usual location or function, exhibit extraordinary level of plasticity and proliferative potential. That fact makes them one of the top candidates for use in applications such as tissue engineering, cell based therapies, regenerative and reconstructive medicine. The potential clinical application, however, need to be based on well developed methods, in order to provide an effective treatment without causing major side effects. To achieve that goal, a large amount of research, aiming to analyze the molecular basics of proliferation and differentiation of epithelial stem cells, and stem cells in general, needs to be conducted.

Open access
Does migrative and proliferative capability of epithelial cells reflect cellular developmental competence?

Abstract

Mammalian epithelial and epithelial-like cells are significantly involved in various processes associated with tissue development, differentiation and oncogenesis. Because of that, high number of research is focused on identifying cells that express stem-like or progenitor characteristics. Identifying such cells and recognizing their specific markers, would open new clinical opportunities in transplantology and oncology. There are several epithelia characterized by their ability to rapidly proliferate and/or differentiate. Due to their function or location they are subject to cyclic changes involving processes of apoptosis and regeneration. Literature presenting well-structured studies of these types of epithelia was analyzed in order to compare various results and establish if epithelial cells’ migrative and proliferative ability indicates their stemness potential. Endometrial, ovarian, oviductal and oral mucosal epithelia were analyzed with most of the publications delivering relatively unified results. The ability to rapidly proliferate/differentiate usually indicated the presence of some kind of stem/stem-like/progenitor cells. Most of the papers focused on pinpointing the exact location of these kind of cells, or analyzing specific markers that would be used for their future identification. There have also been substantial proportion of research that focused on discovering growth factors or intercellular signals that induced proliferation/differentiation in analyzed epithelia. Most of the research provided valuable insights into the modes of function and characteristics of the analyzed tissue, outlining the importance of such study for the possible clinical application of in vitro derived cell cultures.

Open access