Kypreou Katerina P, Sourlingas Thomae G, Sekeri-Pataryas Kalliope E
Institute of Biology, National Centre for Scientific Research, 'Demokritos', Aghia Paraskevi 153 10, Athens, Greece.
Exp Gerontol. 2004 Apr;39(4):469-79. doi: 10.1016/j.exger.2003.12.014.
In the present study we investigated the age-related response of Phytohemaglutinin (PHA)-activated S phase human lymphocytes isolated from peripheral blood from donors of four different age groups, namely young (25-30 years), mid-aged (40-45 years), senior (60-65 years) and elderly (80-95 years) on the induction of the linker histone variant, H1 degrees and histone H4 acetylation after treatment with the very specific histone deacetylase (HDAC) inhibitor, trichostatin A (TSA). The cell system of peripheral blood lymphocytes is ideal for the study of H1 degrees induction since they do not synthesize this particular linker histone variant. Lymphocytes isolated from peripheral blood were activated with PHA (5 microg/10(6) cells/ml medium) and placed in culture for a duration of 72 h at which time cells are in the S phase. Forty-eight hours after inoculation, TSA (250 ng/10(6) cells/ml medium) was added to the cell cultures for a period of 24 h. Assays were performed 72 h after initiation of cultures. The results showed that the induction of H1 degrees after TSA treatment increased to a statistically significant degree in the elderly age group with respect to both the young and the mid-aged age groups. Moreover histone H4 acetylation was found to increase as a function of increasing donor age. A hyperacetylation pattern was observed even in the youngest age group analyzed. Specifically, the tetra-acetylated (H4.4) H4 form increased to a statistically significant degree with the concomitant decrease in the non-acetylated H4 for (H4.0) as a function of donor age. The other acetylated H4 forms (H4.1, H4.2, and H4.3) remained more or less constant, irrespective of donor age. These results show that the sensitivity of lymphocytes to TSA is enhanced with increasing donor age. Since to date, 11 class I and II HDACs have been isolated that have been found by other investigators to have differential responses to HDAC inhibitors, these findings may indicate that there is also a differential age-related response of certain HDACs or perhaps a senescent-specific HDAC. This line of research warrants further study.
在本研究中，我们调查了从四个不同年龄组供体的外周血中分离出的经植物血凝素（PHA）激活的S期人淋巴细胞，即青年组（25 - 30岁）、中年组（40 - 45岁）、老年组（60 - 65岁）和高龄组（80 - 95岁），在用非常特异的组蛋白去乙酰化酶（HDAC）抑制剂曲古抑菌素A（TSA）处理后，连接组蛋白变体H1°和组蛋白H4乙酰化的诱导情况。外周血淋巴细胞的细胞系统对于研究H1°诱导是理想的，因为它们不合成这种特定的连接组蛋白变体。从外周血分离的淋巴细胞用PHA（5μg/10⁶细胞/ml培养基）激活，并在培养72小时，此时细胞处于S期。接种48小时后，将TSA（250 ng/10⁶细胞/ml培养基）加入细胞培养物中24小时。在培养开始72小时后进行测定。结果表明，与青年组和中年组相比，TSA处理后H1°的诱导在高龄组中增加到具有统计学显著意义的程度。此外，发现组蛋白H4乙酰化随着供体年龄的增加而增加。即使在分析的最年轻年龄组中也观察到高乙酰化模式。具体而言，随着供体年龄的增加，四乙酰化（H4.4）H4形式增加到具有统计学显著意义的程度，同时非乙酰化H4（H4.0）减少。其他乙酰化H4形式（H4.1、H4.2和H4.3）无论供体年龄如何，都或多或少保持恒定。这些结果表明，淋巴细胞对TSA的敏感性随着供体年龄的增加而增强。由于迄今为止，已经分离出11种I类和II类HDAC，其他研究人员发现它们对HDAC抑制剂有不同的反应，这些发现可能表明某些HDAC也存在与年龄相关的差异反应，或者可能存在衰老特异性HDAC。这一研究方向值得进一步研究。
