Eto Shigehiko, Isome Masato, Sano Hideki, Fukuda Yutaka, Kawasaki Yukihiko, Suzuki Junzo, Igarashi Kazuei, Satriano Joseph, Suzuki Hitoshi
Department of Pediatrics, Fukushima Medical University School of Medicine, Fukushima, Japan.
Tohoku J Exp Med. 2006 Oct;210(2):145-51. doi: 10.1620/tjem.210.145.
Polyamines play an essential role in the growth and differentiation of mammalian cells. The depletion of intracellular polyamines results in the suppression of growth. Proliferation of glomerular mesangial cells (MC) is the most common pathologic change in many forms of glomerulonephritis. Agmatine is a metabolite of arginine via arginine decarboxylase (ADC), highly expressed in the kidney, and unique in its capacity to suppress intracellular polyamine levels required for proliferation. As agmatine enters mammalian cells via the polyamine transport system, its antiproliferative effects may preferentially target cells with increased proliferative kinetics. In the present study, we evaluated the antiproliferative effects of agmatine on human MC in vitro. MC proliferation was stimulated with 20% fetal bovine serum (FBS) or platelet-derived growth factor (PDGF-BB, 20 ng/ml). Cell proliferation was measured using the (4.3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) (MTT) proliferation assay. Intracellular polyamine levels were assayed by high performance liquid chromatography, and cell death was assessed by cellular DNA fragmentation enzyme-linked immunosorbent assay. The MTT proliferation assay showed that agmatine significantly suppressed proliferation of human MC treated with 20% FBS or 5% FBS + PDGF as compared to human MC treated with 5% FBS. Polyamine levels were markedly lower in cells treated with agmatine, and proliferation was rescued by administration of putrescine. The fragmented DNA was hardly detected in agmatine-treated human MC. In summary, human MC stimulated to increase their proliferative kinetics are significantly more sensitive to the antiproliferative effects of agmatine than normally cultured cells. Suppressed proliferation of the agmatine-treated human MC is not due to increased cell death. These results suggest that agmatine is a promising drug candidate for the treatment of human mesangial proliferative glomerulonephritis.
多胺在哺乳动物细胞的生长和分化过程中发挥着至关重要的作用。细胞内多胺的耗竭会导致生长受到抑制。肾小球系膜细胞（MC）的增殖是多种形式肾小球肾炎最常见的病理变化。胍丁胺是精氨酸经精氨酸脱羧酶（ADC）代谢生成的产物，在肾脏中高表达，其独特之处在于能够抑制增殖所需的细胞内多胺水平。由于胍丁胺通过多胺转运系统进入哺乳动物细胞，其抗增殖作用可能优先针对增殖动力学增加的细胞。在本研究中，我们评估了胍丁胺对人MC的体外抗增殖作用。用20%胎牛血清（FBS）或血小板衍生生长因子（PDGF - BB，20 ng/ml）刺激MC增殖。使用（4,5 - 二甲基噻唑 - 2 - 基） - 2,5 - 二苯基溴化四氮唑（MTT）增殖试验测量细胞增殖。通过高效液相色谱法测定细胞内多胺水平，并通过细胞DNA片段化酶联免疫吸附试验评估细胞死亡情况。MTT增殖试验表明，与用5% FBS处理的人MC相比，胍丁胺显著抑制了用20% FBS或5% FBS + PDGF处理的人MC的增殖。用胍丁胺处理的细胞中多胺水平明显较低，而通过给予腐胺可挽救增殖。在胍丁胺处理的人MC中几乎检测不到片段化DNA。总之，刺激增殖动力学增加的人MC对胍丁胺的抗增殖作用比正常培养的细胞明显更敏感。胍丁胺处理的人MC增殖受抑制并非由于细胞死亡增加。这些结果表明，胍丁胺是治疗人系膜增生性肾小球肾炎的有前景的候选药物。
