Kapasi A A, Singhal P C
Department of Medicine, Long Island Jewish Medical Center, New Hyde Park, New York 11040, USA.
Mol Cell Biol Res Commun. 1999 Apr;1(1):78-81. doi: 10.1006/mcbr.1999.0106.
Aging is associated with altered immune function. We previously reported that splenocytes and thymocytes undergo apoptosis with aging in rats. In the present study, we examined the expression of genes associated with apoptosis in splenocytes and thymus in aging rats. We evaluated the expression of bax, interleukin 1-beta-converting enzyme (ICE)/ced-3 protease family, caspase-3 and tumor suppressor gene p53. Rats in age groups of 6, 24, 48, and 96 weeks were sacrificed; thymocytes and splenocytes were isolated followed by lysis in a modified RIPA buffer containing protease inhibitors. Western blot analysis of proteins was performed by probing immunoblots with antibodies against p53, bax and PARP (poly ADP-ribose polymerase). Increased aging was associated with enhanced expression of bax, p53 and cleavage of PARP by Caspase-3. The expression of p53 and cleavage of PARP indicates the presence of damaged DNA; nevertheless, the cleavage of PARP or activation of caspase-3 may be playing an important role in the initiation of early events in apoptosis. These results suggest that aging of splenocytes and thymocytes is associated with the expression of cell death genes. The present study provides an insight into age-associated altered immune function.
衰老与免疫功能改变相关。我们之前报道过，大鼠的脾细胞和胸腺细胞会随着衰老而发生凋亡。在本研究中，我们检测了衰老大鼠脾细胞和胸腺中与凋亡相关基因的表达。我们评估了bax、白细胞介素1-β转换酶（ICE）/ced-3蛋白酶家族、半胱天冬酶-3和肿瘤抑制基因p53的表达。处死6周、24周、48周和96周龄组的大鼠；分离胸腺细胞和脾细胞，然后在含有蛋白酶抑制剂的改良RIPA缓冲液中裂解。通过用抗p53、bax和PARP（聚ADP核糖聚合酶）的抗体探测免疫印迹来进行蛋白质的蛋白质印迹分析。衰老加剧与bax、p53的表达增强以及半胱天冬酶-3对PARP的切割有关。p53的表达和PARP的切割表明存在受损DNA；然而，PARP的切割或半胱天冬酶-3的激活可能在凋亡早期事件的启动中起重要作用。这些结果表明，脾细胞和胸腺细胞的衰老与细胞死亡基因的表达有关。本研究为与年龄相关的免疫功能改变提供了深入见解。
