Wyniki wyszukiwania - Biblioteka Nauki

1

Selected small molecules as inducers of pluripotency

100%

Baranek M. , Markiewicz W. , Barciszewski J.

Acta Biochimica Polonica

|

2016

|

tom 63

|

nr 4

709-716

EN

The general idea of regenerative medicine is to fix or replace tissues or organs with live and patient-specific implants. Pluripotent stem cells are capable of indefinite self-renewal and differentiation into all cell types of the body. An easily accessible source of induced pluripotent stem cells (iPSCs) may allow obtaining and culturing tissues in vitro. Many approaches in the methods leading to obtain iPSCs have been tested in order to limit immunogenicity and tumorigenesis, and to increase efficiency. One of the approaches causing pluripotency is usage of small molecule compounds. It would be of great importance to assess their specific properties and reveal their new capacity to induce pluripotent stem cells and to improve reprogramming efficiency. Identification of the epigenetic changes during cellular reprogramming will extend our understanding of stem cell biology and many therapeutic applications. In this paper we discuss mainly the nucleotide derivatives, already proven or for now only putative inducers of the cells' pluripotency, that modulate the epigenetic status of the cell.

2

The modulation of HIFs, pluripotency and differentiation genes expression by oxygen conditions in neural stem cells derived from human cord blood

63%

Szablowska-Gadomska I. , Drela K. , Podobinska M. , Ziemka-Nalecz M. , Domanska-Janik K. , Buzanska L.

|

tom 73

|

nr 1

EN

The oxygen tension is an important factor modulating cell fate and developmental decisions. There are evidences that HIFs (Hypoxia Inducible Factors) family is implicated in the regulation of pluripotency and differentiation genes. The goal of this study is to compare the influence of close to physiological oxygen conditions (5%) to atmospheric oxygen tension on differentiation process and pluripotent activity in HUCB-NSC. The expression of Hypoxia Inducible Factors, stemness and neural differentiation markers in NSC, cultured under 5% and 21% oxygen were checked on the transcriptional and translational level. We were looking at the interaction between HIFs (HIF1 alpha, HIF 2 alpha) and activity of neural differentiations genes (MAP2, GFAP, β-tubulin) as well as expression of pluripotency genes (Oct4, Sox2, Rex1 and Nanog). In order to demonstrate the impact of increased HIF1α and/ or HIF2α level on cell differentiation we used DMOG (Sigma) which is of prolyl-4-hydroksylase inhibitor to increase HIF alpha levels. Our data show, that low oxygen conditions promote proliferation of HUCBNSC at early stage of development and can activate Oct4 and Nanog genes in HUCB-NSC. The time of cultivation of the cells in low oxygen conditions and the developmental stage of the cells are the important factors for the induction of the expression of “pluripotency” genes.Hypoxia Inducible Factors HIF 1α and HIF 2α, but not HIF3α are expressed in HUCB-NSC at all stages of development. During neuronal differentiation of HUCB-NSC by using dBcAMP, 5% oxygen level act synergistically, promoting further differentiation (enhanced MAP2 expression). Application of prolyl hydroxylase inhibitor – DMOG resulted in increased expression of HIF1α but not HIF2α and increased the expression of MAP2 (only in 21% oxygen conditions) referring to variants without DMOG. Sponsored by grant from Polish Ministry of Scientific Research and Higher Education No N N302 597838 and by NSC grant No 2011/01/B/NZ3/05401

3

Techniques of human embryonic stem cell and induced pluripotent stem cell derivation

63%

Lewandowski J. , Kurpisz M.

|

2016

|

tom 64

|

nr 5

4

From blastomeres to somatic cells: reflections on cell developmental potential in light of chimaera studies - a review

63%

Zyzynska-Galenska K. , Piliszek A. , Modlinski J. A.

Animal Science Papers and Reports

|

2017

|

tom 35

|

nr 3

EN

Mammalian development is a process, whereby cells from a totipotent zygote gradually lose their potency, i.e. their ability to differentiate, in the environment of the developing embryo. An ideal model for testing the real potential of cells is the experimental production of chimaeras. The first experimentally produced mammalian (murine) chimaeras were created by Tarkowski [1961] and since then many new methods of chimaera production have been developed, including injecting cells into the blastocyst’s cavity or into cleaving embryos. This review describes how different cell types, depending on the developmental stage or culture conditions, manifest their potential to contribute to chimaeras. Cell developmental potential has been analysed in pluripotent blastomeres, which can contribute to all embryonic and extra-embryonic lineages, albeit differently depending on their developmental stage. This is the case in blastocyst lineages, with various developmental potentials depending on the surrounding cells, and in more differentiated cells from different stages of pregnancy, which in some cases may colonise chimaeric animal tissue. Cell potential has also been analysed in embryonic stem and embryonal carcinoma cells, which are pluripotent and efficiently contribute to chimaeras; in multipotent fetal and adult stem cells, which can also participate in chimaera formation; and in somatic mouse embryonic fibroblasts (MEFs), which can also be reprogrammed in the environment of the cleaving embryo. Interspecies chimaera studies have also demonstrated the pluripotency of foreign cells. Experiments with chimaeras have shown that not only pluripotent embryonic cells are capable of contributing to chimaeras, so are adult cells, which plasticity is now well-documented.