PDF(Pubmed)
Abstract：
UNASSIGNED: Cardiac arrhythmias are the main cause of sudden death due to Chronic Chagasic Cardiomyopathy (CCC). Here we investigated alterations in connexin 43 (Cx43) expression and phosphorylation in cardiomyocytes as well as associations with cardiac arrhythmias in CCC.
UNASSIGNED: C57Bl/6 mice infected with Trypanosoma cruzi underwent cardiac evaluations at 6 and 12 months after infection via treadmill testing and EKG. Histopathology, cytokine gene expression, and distribution of total Cx43 and its phosphorylated forms Cx43S368 and Cx43S325/328/330 were investigated. Human heart samples obtained from subjects with CCC were submitted to immunofluorescence analysis. In vitro simulation of a pro-inflammatory microenvironment (IL-1β, TNF, and IFN-γ) was performed in H9c2 cells and iPSC-derived cardiomyocytes to evaluate Cx43 distribution, action potential duration, and Lucifer Yellow dye transfer.
UNASSIGNED: Mice chronically infected with T. cruzi exhibited impaired cardiac function associated with increased inflammation, fibrosis and upregulated IL-1β, TNF, and IFN-γ gene expression. Confocal microscopy revealed altered total Cx43, Cx43S368 and Cx43S325/328/330 localization and phosphorylation patterns in CCC, with dispersed staining outside the intercalated disc areas, i.e., in lateral membranes and the cytoplasm. Reduced co-localization of total Cx43 and N-cadherin was observed in the intercalated discs of CCC mouse hearts compared to controls. Similar results were obtained in human CCC heart samples, which showed Cx43 distribution outside the intercalated discs. Stimulation of human iPSC-derived cardiomyocytes or H9c2 cells with IL-1β, TNF, and IFN-γ induced alterations in Cx43 localization, reduced action potential duration and dye transfer between adjacent cells.
UNASSIGNED: Heart inflammation in CCC affects the distribution and phosphorylation pattern of Cx43, which may contribute to the generation of conduction disturbances in Chagas disease.
UNASSIGNED: C57Bl/6 mice infected with Trypanosoma cruzi underwent cardiac evaluations at 6 and 12 months after infection via treadmill testing and EKG. Histopathology, cytokine gene expression, and distribution of total Cx43 and its phosphorylated forms Cx43S368 and Cx43S325/328/330 were investigated. Human heart samples obtained from subjects with CCC were submitted to immunofluorescence analysis. In vitro simulation of a pro-inflammatory microenvironment (IL-1β, TNF, and IFN-γ) was performed in H9c2 cells and iPSC-derived cardiomyocytes to evaluate Cx43 distribution, action potential duration, and Lucifer Yellow dye transfer.
UNASSIGNED: Mice chronically infected with T. cruzi exhibited impaired cardiac function associated with increased inflammation, fibrosis and upregulated IL-1β, TNF, and IFN-γ gene expression. Confocal microscopy revealed altered total Cx43, Cx43S368 and Cx43S325/328/330 localization and phosphorylation patterns in CCC, with dispersed staining outside the intercalated disc areas, i.e., in lateral membranes and the cytoplasm. Reduced co-localization of total Cx43 and N-cadherin was observed in the intercalated discs of CCC mouse hearts compared to controls. Similar results were obtained in human CCC heart samples, which showed Cx43 distribution outside the intercalated discs. Stimulation of human iPSC-derived cardiomyocytes or H9c2 cells with IL-1β, TNF, and IFN-γ induced alterations in Cx43 localization, reduced action potential duration and dye transfer between adjacent cells.
UNASSIGNED: Heart inflammation in CCC affects the distribution and phosphorylation pattern of Cx43, which may contribute to the generation of conduction disturbances in Chagas disease.
摘要：
■心律失常是慢性Chagasic心肌病（CCC）导致猝死的主要原因。在这里，我们研究了心肌细胞中连接蛋白43（Cx43）表达和磷酸化的变化以及与CCC中心律失常的关联。
■感染克氏锥虫的C57Bl/6小鼠在感染后6个月和12个月通过跑步机测试和EKG进行心脏评估。组织病理学,细胞因子基因表达，研究了总Cx43及其磷酸化形式Cx43S368和Cx43S325/328/330的分布。从患有CCC的受试者获得的人心脏样品进行免疫荧光分析。促炎微环境的体外模拟(IL-1β，TNF,和IFN-γ）在H9c2细胞和iPSC衍生的心肌细胞中进行评估Cx43分布，动作电位持续时间，和路西法黄染料转移。
■慢性感染克氏杆菌的小鼠表现出与炎症增加相关的心脏功能受损，纤维化和上调IL-1β，TNF,和IFN-γ基因表达。共聚焦显微镜显示CCC中总Cx43、Cx43S368和Cx43S325/328/330的定位和磷酸化模式发生了改变，在插入的椎间盘区域之外有分散的染色，即，在侧膜和细胞质中。与对照相比,在CCC小鼠心脏的插入盘中观察到总Cx43和N-钙黏着蛋白的共定位减少。在人类CCC心脏样本中获得了类似的结果，显示Cx43在插层圆盘外分布。用IL-1β刺激人iPSC来源的心肌细胞或H9c2细胞，TNF,和IFN-γ诱导的Cx43定位改变，减少动作电位持续时间和相邻细胞之间的染料转移。
■CCC中的心脏炎症影响Cx43的分布和磷酸化模式，这可能有助于恰加斯病中传导障碍的产生。
■感染克氏锥虫的C57Bl/6小鼠在感染后6个月和12个月通过跑步机测试和EKG进行心脏评估。组织病理学,细胞因子基因表达，研究了总Cx43及其磷酸化形式Cx43S368和Cx43S325/328/330的分布。从患有CCC的受试者获得的人心脏样品进行免疫荧光分析。促炎微环境的体外模拟(IL-1β，TNF,和IFN-γ）在H9c2细胞和iPSC衍生的心肌细胞中进行评估Cx43分布，动作电位持续时间，和路西法黄染料转移。
■慢性感染克氏杆菌的小鼠表现出与炎症增加相关的心脏功能受损，纤维化和上调IL-1β，TNF,和IFN-γ基因表达。共聚焦显微镜显示CCC中总Cx43、Cx43S368和Cx43S325/328/330的定位和磷酸化模式发生了改变，在插入的椎间盘区域之外有分散的染色，即，在侧膜和细胞质中。与对照相比,在CCC小鼠心脏的插入盘中观察到总Cx43和N-钙黏着蛋白的共定位减少。在人类CCC心脏样本中获得了类似的结果，显示Cx43在插层圆盘外分布。用IL-1β刺激人iPSC来源的心肌细胞或H9c2细胞，TNF,和IFN-γ诱导的Cx43定位改变，减少动作电位持续时间和相邻细胞之间的染料转移。
■CCC中的心脏炎症影响Cx43的分布和磷酸化模式，这可能有助于恰加斯病中传导障碍的产生。
