Lezhava Teimuraz, Monaselidze Jamlet, Jokhadze Tinatin, Gorgoshidze Maia, Kiladze Maia, Gaiozishvili Maia
Department of Genetics, Iv. Javakishvili Tbilisi State University, Chavchavadze ave.1, Tbilisi, Georgia.
Age (Dordr). 2011 Sep;33(3):433-8. doi: 10.1007/s11357-010-9185-1. Epub 2010 Sep 24.
The levels of chromosome instability and heat absorption of chromatin have been studied in cultured lymphocytes derived from blood of 80-93- and 18-30-year-old individuals, under the effect of heavy metal Cu(II) and Cd(II) salts. The analysis of the results obtained indicates that 50 μM Cu(II) induced a significantly higher level of cells with chromosome aberrations in old donors (13.8 ± 1.5% vs control, 3.8 ± 1.7%), whereas treatment with 100 μM Cd(II) did not induce any changes in the background index. Analysis of the lymphocyte melting curves showed that Cu(II) ions caused more effective condensation of heterochromatin in old healthy individuals compared with young donors, which was expressed by the increase of the T (m) of elderly chromatin by ~3°C compared with the norm. Treatment of lymphocyte chromatin of old individuals with 100 μM Cd(II) caused decondensation (deheterochromatinization) of both the facultative and constitutive domains of heterochromatin. The deheterochromatinization T (m) was decreased by ~3-3.5°C compared with the T (m) observed for young individuals. Thus, the chromatin of cultured lymphocytes from the old-aged individuals underwent modification under the influence of copper and cadmium salts. Cu(II) caused additional heterochromatinization of heterochromatin, and Cd(II) caused deheterochromatinization of facultative and constitutive heterochromatin. Our data may be important as new information on the remodeling of constitutive and facultative heterochromatin induced by heavy metals in aging, aging pathology, and pathology linked with metal ions.
在重金属铜（II）和镉（II）盐的作用下，对来自80 - 93岁和18 - 30岁个体血液的培养淋巴细胞中的染色体不稳定性水平和染色质的热吸收进行了研究。对所得结果的分析表明，50μM铜（II）在老年供体中诱导出具有染色体畸变的细胞水平显著更高（13.8±1.5%对比对照组，3.8±1.7%），而用100μM镉（II）处理未引起背景指数的任何变化。淋巴细胞解链曲线分析表明，与年轻供体相比，铜（II）离子在老年健康个体中导致异染色质更有效的凝聚，这表现为老年染色质的熔解温度（Tm）比正常升高约3°C。用100μM镉（II）处理老年个体的淋巴细胞染色质导致异染色质的兼性和组成性结构域解聚（去异染色质化）。与年轻个体观察到的Tm相比，去异染色质化的Tm降低了约3 - 3.5°C。因此，老年个体培养淋巴细胞的染色质在铜盐和镉盐的影响下发生了修饰。铜（II）导致异染色质额外的异染色质化，而镉（II）导致兼性和组成性异染色质的去异染色质化。我们的数据作为关于衰老、衰老病理学以及与金属离子相关病理学中重金属诱导的组成性和兼性异染色质重塑的新信息可能具有重要意义。
