The formation, metabolism and the evolution of blood platelets
Journal Title: Advances in Hygiene and Experimental Medicine - Year 2014, Vol 68, Issue
Abstract
Platelets are the smallest, depleted of nucleus blood cells which contain a typical cellular organelles including the mitochondria, so that have active metabolism. Platelets possess the highly organized cytoskeleton, specific secretory granules and unique membrane receptors system responsible for their high reactivity. The key role of blood platelets is to maintain normal hemostasis, but they also play important roles in inflammation, immune processes and the cancer progression. The anucleated, small platelets occur in representatives of all clusters of mammals, so it seems to be an adaptation feature. In other vertebrates similar hemostatic functions are played by large nucleated platelets, which are much more weakly reactive. Small, reactive platelets, appearing in the evolution of mammals, allowed the formation of clots faster and slower blood loss in case of injury, but also increased the risk of thromboembolic and cardiovascular diseases. Daily the human body forms about 1x1011 platelets, which are produced by a process of differentiation, maturation and fragmentation of the cytoplasm of mature megakaryocytes. The emergence of platelets is the final stage of megakaryocyte differentiation and is followed by formation of the direct precursors called proplatelets. The anucleated platelets are regarded as terminally differentiated cells, which are not capable of further cell division. However, despite the absence of a nucleus, in blood platelets the synthesis and transcription of mitochondrial DNA and protein synthesis occurring on the basis of mRNA from megakaryocytes has been confirmed. However, recent studies published in 2012 show that the platelets are capable not only of the process of protein synthesis, but also of generation of new cells, which are functionally and structurally similar to the parent platelets.
Authors and Affiliations
Joanna Saluk, Michał Bijak, Michał B. Ponczek, Barbara Wachowicz
Czynne usuwanie leku z komórki jako jeden z mechanizmów oporności bakterii na środki przeciwdrobnoustrojowe i metody jego zwalczania
Pompy MDR stanowią powszechny mechanizm oporności wielu gatunków bakterii, polegający na transporcie poza komórkę m.in. leków, toksyn i środków dezynfekcyjnych i antyseptycznych. Pompy, których swoistość substratowa jest...
HMGB1 – its role in tumor progression and anticancer therapy
HMGB1 is an evolutionarily conserved protein with a wide spectrum of action. Its main receptors are RAGE and TLR found on the surface of immune system cells as well as endothelial cells. Although signaling pathways for b...
Second code, or what determines actively transcribed regions and replication origins
Although each cell of a complex organism is governed by the same genome, cells which form different tissues vary in epigenetic codes that are responsible for various gene expression. These codes, through their influence...
Oxidation and deamination of nucleobases as an epigenetic tool
Recent discoveries have demonstrated that 5-methylcytosine (5mC) may be hydroxymethylated to 5-hydroxymethylcytosine (5hmC) in mammals and that genomic DNA may contain about 0.02–0.7% of 5hmC. The aforementioned modific...
The cytokines in inflammatory bowel disease
Inflammatory bowel disease includes ulcerative colitis and Crohn’s disease. It is a group of chronic disorders of unknown etiology characterized by inflammation of the gastrointestinal tract. The etiopathogenesis of infl...