Pantic Igor, Paunovic Jovana, Vucevic Danijela, Radosavljevic Tatjana, Dugalic Stefan, Petkovic Anita, Radojevic-Skodric Sanja, Pantic Senka
Laboratory for Cellular Physiology, Institute of Medical Physiology, Faculty of Medicine, University of Belgrade, Visegradska 26/II, RS-11129 Belgrade, Serbia.
University of Haifa, 199 Abba Hushi Blvd, Mount Carmel, Haifa 3498838, Israel.
Microsc Microanal. 2017 Oct;23(5):1024-1029. doi: 10.1017/S1431927617012545. Epub 2017 Sep 18.
Although there are numerous recent works focusing on fractal properties of DNA and chromatin, many issues regarding changes in chromatin fractality during physiological aging remain unclear. In this study, we present results indicating that in mice, there is an age-related reduction of chromatin fractal complexity in a population of spleen follicular cells (SFCs). Spleen tissue was obtained from 16 mice and fixated in Carnoy solution. The youngest animal was newborn, and each animal was exactly 1 month older than the previous. We performed fractal analysis of SFC chromatin structure, stained using Giemsa technique. Fractal analysis was done in a plugin algorithm of ImageJ software. We also performed gray-level co-occurrence matrix (GLCM) analysis of all chromatin structures with the calculation of parameters such as angular second moment and inverse difference moment. Giemsa-stained SFC chromatin exhibited an age-dependent reduction of fractal dimension with statistically significant (p<0.01) linear trend. Moreover, there was a statistically significant increase of SFC chromatin lacunarity. The chromatin GLCM parameters did not significantly change. To our knowledge, this is the first study to perform fractal and GLCM analyses of SFC chromatin and to investigate potential changes of fractal parameters during postnatal development.
尽管近期有许多研究聚焦于DNA和染色质的分形特性,但关于生理衰老过程中染色质分形性变化的许多问题仍不明确。在本研究中,我们呈现的结果表明,在小鼠中,脾滤泡细胞(SFCs)群体中染色质分形复杂性存在与年龄相关的降低。从16只小鼠获取脾组织并固定于卡诺伊溶液中。最年幼的动物为新生小鼠,每只动物比前一只大1个月整。我们对采用吉姆萨技术染色的SFC染色质结构进行了分形分析。分形分析在ImageJ软件的一个插件算法中进行。我们还对所有染色质结构进行了灰度共生矩阵(GLCM)分析,并计算了角二阶矩和逆差矩等参数。吉姆萨染色的SFC染色质呈现出分形维数随年龄降低的趋势,具有统计学显著(p<0.01)的线性趋势。此外,SFC染色质孔隙率有统计学显著增加。染色质GLCM参数没有显著变化。据我们所知,这是第一项对SFC染色质进行分形和GLCM分析并研究出生后发育过程中分形参数潜在变化的研究。