Somatic polyploidy was found in the tissues of all multicellular organisms (including algae, mosses, lichens, vascular plants, invertebrates, and vertebrates), which points to its adaptive value. In human and warm-blooded animals, polyploidy can be a part of normal postnatal morphogenetic programs and can be a manifestation of response to pathological stimuli and diseases.
Figure 62. Polyploidy and developmental programming of adult diseases show similar properties.
Experimental Studies Confirm the Role of Polyploidy in the Developmental Programming of Health and Disease
Recent experimental and clinical studies confirm that polyploidy can be involved in the developmental programming of adult diseases. The most convincing evidence was obtained for cardiovascular diseases that are the most susceptible to developmental programming. Thus, studies in sheep indicated that pre-term birth irreversibly increases the percentage of polyploid mononuclear cardiomyocyte and induces DNA damage, fibrosis, and lymphocytic infiltration [60]. In humans, pathologic hemodynamic load during postnatal growth permanently increases cardiomyocyte ploidy and decreases cardiac performance [33][57][65][66][33][57][67][68][69]. The inflammatory stress caused by gastroenteritis in the rat resulted in cardiomyocyte hyperpolyploidization, long-term atrophy, and cell remodeling [59][70]. The experimental model of gastroenteritis was used as gastroenteritis triggers developmental programming factors, including inflammation, growth retardation, and malabsorption, and as gastroenteritis is a major cause of diseases in toddlers, infants, and children [71][72][73]. Both types of neonatal gastroenteritis cause irreversible excessive polyploidization, long-term atrophy, and remodeling of cardiomyocytes [59][74][70]. Altogether, these data indicate that polyploidy can be involved in developmental programming as it is irreversible, responds to programming stimuli during the critical period of development, changes cell phenotype, and weakens cell function, thus meeting all basic criteria of developmental programming.