THE MAIN SIGNALING SYSTEMS INVOLVED IN THE FUNCTIONING OF STEM CELLS (review of literature data)

Abstract

Modern hormone replacement therapy for endocrine disorders cannot reproduce the complex interactions of hormones. Cell transplantation is a more physiological approach to the treatment of endocrine gland dysfunction. The data obtained indicate the effectiveness of the stem cells (SCs) use for the treatment of endocrine diseases and, first of all, type 1 diabetes. SCs are cells with clonogenic potential that can repair themselves and differentiate into different types of cells. They are responsible for the regeneration and development of organs and tissues. SCs provide many opportunities for regenerative medicine and serve as a promising model system for studying the early stages of human embryo development. Many molecular mechanisms underlying SCs self-repair and carcinogenesis have been elucidated. The main signaling pathways involved in SCs are JAK/STAT (Janus kinase/signal transducer and activator of transcription), Notch, MAPK/ERK, PI3K/Akt, NF-κB, Wnt, Hedgehog (Hh), TGF-β (transforming growth factor beta) and Hippo, and analysis of their status and sequence of activation, suppression and interaction is important in the context of SCs functioning. The differentiation process of a pluripotent cell in vitro has a low efficiency. Many differentiated cells are characterized by dysregulated signaling pathways, and molecular markers for each stage of the differentiation process have not yet been identified. The development of protocols for the differentiation of pluripotent cells into β-cells that produce insulin in vitro, and their transplantation, engraftment in the body requires a clear understanding of the involvement and cross-interaction of a range of cell signaling systems. Studies of the signaling network required to maintain stemness have identified a strong correlation of these pathways with cancer signaling pathways, as well as the general cellular properties of embryonic SCs and cancer cells, which cannot be dismissed as coincidence. Studying these parallels will inevitably affect both clinical and fundamental sciences. Key words: stem cells, signaling pathways.