Huang Huan, Petkova Stefka B, Cohen Alex W, Bouzahzah Boumediene, Chan John, Zhou Jian-nian, Factor Stephen M, Weiss Louis M, Krishnamachary Mohan, Mukherjee Shankar, Wittner Murray, Kitsis Richard N, Pestell Richard G, Lisanti Michael P, Albanese Chris, Tanowitz Herbert B
Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Infect Immun. 2003 May;71(5):2859-67. doi: 10.1128/IAI.71.5.2859-2867.2003.
The myocardium of CD1 mice was examined for the activation of signal transduction pathways leading to cardiac inflammation and subsequent remodeling during Trypanosoma cruzi infection (Brazil strain). The activity of three pathways of the mitogen-activated protein kinases (MAPKs) was determined. Immunoblotting revealed a persistent elevation of phosphorylated (activated) extracellular-signal-regulated kinase (ERK), which regulates cell proliferation. During infection there was a transient activation of p38 MAPK but no activation of Jun N-terminal kinase. Early targets of activated ERK, c-Jun and c-Fos, were elevated during infection, as demonstrated by semiquantitative reverse transcription-PCR. Immunostaining revealed that the endothelium and the interstitial cells were most intensely stained with antibodies to c-Jun and c-Fos. Soon after infection, AP-1 and NF-kappa B DNA binding activity was increased. Protein levels of cyclin D1, the downstream target of ERK and NF-kappa B, were induced during acute infection. Immunostaining demonstrated increased expression of cyclin D1 in the vascular and endocardial endothelium, inflammatory cells, and the interstitial areas. Increased expression of the cyclin D1-specific phosphorylated retinoblastoma protein (Ser780) was also evident. Immunoblotting and immunostaining also demonstrated increased expression of proliferating cellular nuclear antigen that was predominantly present in the inflammatory cells, interstitial areas (i.e., fibroblasts), and endothelium. These data demonstrate that T. cruzi infection results in activation of the ERK-AP-1 pathway and NF-kappa B. Cyclin D1 expression was also increased. These observations provide a molecular basis for the activation of pathways involved in cardiac remodeling in chagasic cardiomyopathy.
研究了CD1小鼠在克氏锥虫（巴西株）感染期间，导致心脏炎症及随后重塑的信号转导通路的激活情况。测定了丝裂原活化蛋白激酶（MAPK）三条通路的活性。免疫印迹显示，调节细胞增殖的磷酸化（活化）细胞外信号调节激酶（ERK）持续升高。感染期间，p38 MAPK有短暂激活，但Jun N末端激酶未激活。半定量逆转录 - PCR显示，感染期间，活化ERK的早期靶点c - Jun和c - Fos升高。免疫染色显示，内皮细胞和间质细胞被抗c - Jun和c - Fos抗体染色最深。感染后不久，AP - 1和NF - κB DNA结合活性增加。急性感染期间，ERK和NF - κB的下游靶点细胞周期蛋白D1的蛋白水平升高。免疫染色显示，细胞周期蛋白D1在血管和心内膜内皮、炎症细胞及间质区域的表达增加。细胞周期蛋白D1特异性磷酸化视网膜母细胞瘤蛋白（Ser780）的表达增加也很明显。免疫印迹和免疫染色还显示，增殖细胞核抗原的表达增加，其主要存在于炎症细胞、间质区域（即成纤维细胞）和内皮细胞中。这些数据表明，克氏锥虫感染导致ERK - AP - 1通路和NF - κB激活，细胞周期蛋白D1表达也增加。这些观察结果为恰加斯性心肌病中心脏重塑相关通路的激活提供了分子基础。
