Yu Yue, Ren Da-bin, Sun Ren-yu, Wang Shi-wen
Department of Pathophysiology, Institute of Basic Medical Sciences, CAMS and PUMC, Beijing 100005, China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2006 Dec;28(6):781-5.
To explore roles of extracellular signal-regulated kinase (ERK) 1/2, p38 mitogen activated protein kinase (p38 MAPK) and nuclear factor (NF) -KB in expression of inducible nitric oxide synthase (iNOS) in rat alveolar macrophages induced by high mobility group box 1 (HMGB1 ).
Primary rat alveolar macrophages (PRAMs) cultured in vitro were incubated with PD98059 ( inhibitor against ERK), SB203580 (inhibitor against p38 MAPK) , PDTC (inhibitor against NF-kappaB), or PD98059 plus SB203580 for 2 hours, respectively. HMGB1 was added into the cultures and incubated with cells for 6 hours. Total RNA of PRAMs was extracted and iNOS mRNA expression was semi-quantified with reverse transcription-polymerase chain reaction ( RT-PCR). Greiss reaction was applied to determine nitrite/nitrate (NO2-/NO3- ) concentration in PRAMs culture supernatants.
Expression of iNOS mRNA and NO production in PRAMs culture supernatants were down-regulated by inhibition of ERK or p38 MAPK by PD98059 or SB203580, respectively (P <0. 05). Moreover, inhibition of iNOS expression and NO production was observed after simultaneous pretreatment with PD98059 and SB203580 (P < 0. 05). Expression of iNOS mRNA in PRAMs and NO production in PRAMs culture supernatants were down-regulated by inhibition of NF-kappaB by PDTC (P <0. 05).
Cellular signal molecules of ERK, p38 MAPK, and NF-kappaB all participate in the expression of iNOS and NO production in PRAMs induced by HMGB1.
探讨细胞外信号调节激酶（ERK）1/2、p38丝裂原活化蛋白激酶（p38 MAPK）和核因子（NF）-κB在高迁移率族蛋白B1（HMGB1）诱导的大鼠肺泡巨噬细胞诱导型一氧化氮合酶（iNOS）表达中的作用。
体外培养的原代大鼠肺泡巨噬细胞（PRAMs）分别用PD98059（ERK抑制剂）、SB203580（p38 MAPK抑制剂）、PDTC（NF-κB抑制剂）或PD98059加SB203580孵育2小时。将HMGB1加入培养物中并与细胞孵育6小时。提取PRAMs的总RNA，并用逆转录-聚合酶链反应（RT-PCR）对iNOS mRNA表达进行半定量。采用格里斯反应测定PRAMs培养上清液中亚硝酸盐/硝酸盐（NO2-/NO3-）浓度。
PD98059或SB203580分别抑制ERK或p38 MAPK后，PRAMs培养上清液中iNOS mRNA的表达和NO的产生均下调（P<0.05）。此外，PD98059和SB203580同时预处理后，观察到iNOS表达和NO产生受到抑制（P<0.05）。PDTC抑制NF-κB后，PRAMs中iNOS mRNA的表达和PRAMs培养上清液中NO的产生均下调（P<0.05）。
ERK、p38 MAPK和NF-κB细胞信号分子均参与HMGB1诱导的PRAMs中iNOS的表达和NO的产生。
