Hayashi Toshio, Matsui-Hirai Hisako, Miyazaki-Akita Asaka, Fukatsu Akiko, Funami Jun, Ding Qun-Fang, Kamalanathan Sumitra, Hattori Yuichi, Ignarro Louis J, Iguchi Akihisa
Department of Geriatrics, Nagoya University Graduate School of Medicine, Tsuruma-cho 65, Showa-ku, Nagoya 466-8550, Japan.
Proc Natl Acad Sci U S A. 2006 Nov 7;103(45):17018-23. doi: 10.1073/pnas.0607873103. Epub 2006 Oct 30.
Senescence may contribute to the pathogenesis of atherosclerosis. Although the bioavailability of nitric oxide (NO) is limited in senescence, the effect of NO on senescence and its relationship to cardiovascular risk factors have not been investigated fully. We studied these factors by investigating senescence-associated beta-galactosidase (SA-beta-gal) and human telomerase activity in human umbilical venous endothelial cells (HUVECs). Treatment with NO donor (Z)-1-[2-(2-aminoethyl)-N-(2-aminoethyl)amino]diazen-1-ium-1,2-diolate (DETA-NO) and transfection with endothelial NO synthase (eNOS) into HUVECs each decreased the number of SA-beta-gal positive cells and increased telomerase activity. The NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) abolished the effect of eNOS transfection. The physiological concentration of 17beta-estradiol activated hTERT, decreased SA-beta-gal-positive cells, and caused cell proliferation. However, ICI 182780, an estrogen receptor-specific antagonist, and L-NAME each inhibited these effects. Finally, we investigated the effect of NO bioavailability on high glucose-promoted cellular senescence of HUVECs. Inhibition by eNOS transfection of this cellular senescence under high glucose conditions was less pronounced. Treatment with L-arginine or L-citrulline of eNOS-transfected cells partially inhibited, and combination of L-arginine and L-citrulline with antioxidants strongly prevented, high glucose-induced cellular senescence. These data demonstrate that NO can prevent endothelial senescence, thereby contributing to the anti-senile action of estrogen. The ingestion of NO-boosting substances, including L-arginine, L-citrulline, and antioxidants, can delay endothelial senescence under high glucose. We suggest that the delay in endothelial senescence through NO and/or eNOS activation may have clinical utility in the treatment of atherosclerosis in the elderly.
细胞衰老可能参与动脉粥样硬化的发病机制。尽管一氧化氮（NO）的生物利用度在衰老过程中受到限制，但NO对衰老的影响及其与心血管危险因素的关系尚未得到充分研究。我们通过研究人脐静脉内皮细胞（HUVECs）中的衰老相关β-半乳糖苷酶（SA-β-gal）和人端粒酶活性来探讨这些因素。用NO供体（Z）-1-[2-（2-氨基乙基）-N-（2-氨基乙基）氨基]重氮-1,2-二醇盐（DETA-NO）处理以及将内皮型一氧化氮合酶（eNOS）转染到HUVECs中，均可减少SA-β-gal阳性细胞的数量并增加端粒酶活性。一氧化氮合酶抑制剂N（G）-硝基-L-精氨酸甲酯（L-NAME）消除了eNOS转染的作用。生理浓度的17β-雌二醇激活了hTERT，减少了SA-β-gal阳性细胞，并导致细胞增殖。然而，雌激素受体特异性拮抗剂ICI 182780和L-NAME均抑制了这些作用。最后，我们研究了NO生物利用度对高糖诱导的HUVECs细胞衰老的影响。在高糖条件下，通过eNOS转染抑制这种细胞衰老的作用不太明显。用L-精氨酸或L-瓜氨酸处理eNOS转染的细胞可部分抑制高糖诱导的细胞衰老，而L-精氨酸和L-瓜氨酸与抗氧化剂联合使用则可强烈预防高糖诱导的细胞衰老。这些数据表明，NO可以预防内皮细胞衰老，从而有助于雌激素的抗衰老作用。摄入包括L-精氨酸、L-瓜氨酸和抗氧化剂在内的提高NO水平的物质，可以延缓高糖条件下的内皮细胞衰老。我们认为，通过NO和/或eNOS激活来延缓内皮细胞衰老可能对老年动脉粥样硬化的治疗具有临床应用价值。
