Aging increases nuclear chromatin entropy of erythroid precursor cells in mice spleen hematopoietic tissue

Despite recent advances in hematopoietic tissue research, effects of aging on hematopoietic erythroid precursor (EP) cells are unclear. In this article we present results suggesting that chromatin textural entropy of EP cells in mouse spleen increases with age, while chromatin homogeneity decreases. The experiment was conducted on a total of 32 male Swiss white mice. Spleen tissue was acquired from four age groups: 10 days, 1 month, 4 months, and 7 months old mice. A total of 640 randomly selected, nonoverlapping EP cell nuclei (20 per animal) were analyzed using the gray level co-occurrence matrix method. There was statistically highly significant difference between the age groups, both in chromatin entropy (ANOVA, F = 12.99, p < 0.0001) and in homogeneity (ANOVA, F = 7.05, p < 0.001). When the individual groups were compared (ANOVA post hoc test), statistical difference was detected in all group pairs, except between the animals 4 months and 7 months old, either in chromatin entropy or homogeneity. The detected increase of chromatin disorder in mouse juvenile period/early adulthood suggests that cell intrinsic factors such as epigenetic dysregulation and DNA damage accumulation may have an important role in EP cell aging.