title: Age-related reduction of chromatin fractal dimension in toluidine blue - stained hepatocytes.
abstract: In this study, we proposed a hypothesis that chromatin of mouse hepatocytes exhibits age-related reduction of fractal dimension. This hypothesis was based on previously published works demonstrating that complexity of biological systems such as tissues, decreases during the process of physiological aging. Liver tissue was obtained from 24 male mice divided into 3 age groups: 10-days-old (young, juvenile), 210-days-old (adult) and 390-days-old. The tissue was stained using a modification of toluidine blue (nucleic acid - specific) staining method. A total of 480 chromatin structures (20 for each animal) were analyzed. For each structure, the values of fractal dimension, lacunarity, textural angular second moment and inverse difference moment were calculated using ImageJ software and its plugins. The results indicated the age-related reduction in fractal dimension and increase in lacunarity (p<0.01). Fractal dimension is a potentially good indicator of age associated changes in chromatin structure. To our knowledge, this is the first study to show that fractal complexity of hepatocyte chromatin decreases during the process of physiological aging. Fractal analysis as a method could be useful in detection of small age-related changes in chromatin distribution not otherwise visible with naked eye on conventional tissue micrographs.
authors.affiliation: Laboratory for Cellular Physiology, Institute of Medical Physiology, Faculty of Medicine University of Belgrade, Visegradska 26/II, RS-11129, Belgrade, Serbia. Electronic address: igor.pantic@mfub.bg.ac.rs.
authors.forename: Igor
authors.initials: I
authors.lastname: Pantic
authors.affiliation: Health Center Studenica, Kraljevo, Jug Bogdanova 112, RS-36000, Kraljevo, Serbia.
authors.forename: Danica
authors.initials: D
authors.lastname: Petrovic
authors.affiliation: Laboratory for Cellular Physiology, Institute of Medical Physiology, Faculty of Medicine University of Belgrade, Visegradska 26/II, RS-11129, Belgrade, Serbia.
authors.forename: Jovana
authors.initials: J
authors.lastname: Paunovic
authors.affiliation: Institute of pathological physiology, School of Medicine, University of Belgrade, Dr Subotica 9, RS-11129, Belgrade, Serbia.
authors.forename: Danijela
authors.initials: D
authors.lastname: Vucevic
authors.affiliation: Institute of pathological physiology, School of Medicine, University of Belgrade, Dr Subotica 9, RS-11129, Belgrade, Serbia.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Radosavljevic
authors.affiliation: Institute of Histology and Embryology, School of Medicine, University of Belgrade Visegradska 26/II, RS-11129, Belgrade, Serbia.
authors.forename: Senka
authors.initials: S
authors.lastname: Pantic
mesh_terms: D000818:Animals; D016922:Cellular Senescence / Q000502:physiology*; D002843:Chromatin / Q000378:metabolism*; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism; D008297:Male; D051379:Mice; D013194:Staining and Labeling / Q000379:methods*; D014048:Tolonium Chloride / Q000737:chemistry*
chemical_list: D002843:Chromatin; D014048:Tolonium Chloride
keywords: Aging; Complexity; DNA damage; Euchromatin; Microscopy