Akifusa Sumio, Kamio Noriaki, Shimazaki Yoshihiro, Yamaguchi Noboru, Yamashita Yoshihisa
Department of Preventive Dentistry, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan.
Free Radic Biol Med. 2008 Nov 1;45(9):1326-39. doi: 10.1016/j.freeradbiomed.2008.08.005. Epub 2008 Aug 12.
Adiponectin, produced predominantly by differentiating adipocytes, is a protein hormone with antidiabetic and immunosuppressive properties. Here, we report evidence that treatment with globular adiponectin (gAd) induces apoptosis in murine macrophage-like RAW264 cells through the generation of reactive oxygen and/or nitrogen species (ROS/RNS). Treatment with gAd induced apoptosis and enhanced the activities of caspase-3 and -9, but not caspase-8. The gAd stimulation increased ROS generation and significantly reduced the ratio of NADPH to total NADP. Pretreatment with diphenyleneiodonium or apocynin reduced ROS and apoptosis in gAd-treated cells. In addition, transfection with p47(phox)- or gp91(phox)-specific small interfering RNA (siRNA) partially reduced ROS and apoptosis in response to gAd treatment. These results suggest that the administration of gAd induces apoptosis after ROS generation involving activation of NADPH oxidases. The gAd stimulation increased the release of NO into the culture medium, the activity of nitric oxide synthase (NOS), and the expression of inducible NOS (iNOS) mRNA in RAW264 cells. l-NAME reduced gAd-induced apoptotic cell death. In addition, transfection with an iNOS-specific siRNA markedly reduced the generation of NO and the population of apoptotic cells. Taken together, these results demonstrate that the gAd-induced apoptotic process in RAW264 cells involves ROS and RNS, which are generated by NADPH oxidases and iNOS, respectively.
脂联素主要由分化中的脂肪细胞产生，是一种具有抗糖尿病和免疫抑制特性的蛋白质激素。在此，我们报告证据表明，用球状脂联素（gAd）处理可通过产生活性氧和/或氮物种（ROS/RNS）诱导小鼠巨噬细胞样RAW264细胞凋亡。用gAd处理可诱导凋亡并增强caspase-3和-9的活性，但不增强caspase-8的活性。gAd刺激增加了ROS的产生，并显著降低了NADPH与总NADP的比率。用二苯基碘鎓或夹竹桃麻素预处理可减少gAd处理细胞中的ROS和凋亡。此外，用p47（phox）或gp91（phox）特异性小干扰RNA（siRNA）转染可部分减少对gAd处理的反应中的ROS和凋亡。这些结果表明，给予gAd在ROS产生后诱导凋亡，这涉及NADPH氧化酶的激活。gAd刺激增加了RAW264细胞中NO释放到培养基中的量、一氧化氮合酶（NOS）的活性以及诱导型NOS（iNOS）mRNA的表达。L-NAME减少了gAd诱导的凋亡细胞死亡。此外，用iNOS特异性siRNA转染显著减少了NO的产生和凋亡细胞的数量。综上所述，这些结果表明，gAd诱导RAW264细胞凋亡的过程涉及ROS和RNS，它们分别由NADPH氧化酶和iNOS产生。
