HSP60, Inflammation and Cardiovascular Disease

描述（由申请人提供）：之前我们已经证明细胞外（ex）热休克蛋白（HSP）60导致心肌细胞凋亡和TNF和IL-1$的合成。阻断toll样受体（TLR）4减少，但不消除细胞凋亡，这表明HSP60与TLR4的相互作用是复杂的，涉及其他蛋白。我们的首要假设是HSP60可以引起细胞凋亡和炎症，这与HSP60的异常表达、分布或翻译后修饰有关。我们将扩大我们在这一重要领域的研究，有三个特定的目标，旨在进一步确定HSP60在心力衰竭和其他心血管疾病中的作用。SA1 -探讨exHSP60介导细胞凋亡和炎症的机制。我们将进一步研究TLR4在exHSP60信号传导中的作用，确定TLR4抑制剂itoran是否能在体外和体内减少细胞凋亡，并进一步表征质膜相关HSP60。SA2 -研究细胞外HSP60转运及其翻译后修饰在其毒性中的作用。我们假设HSP60的翻译后修饰影响了它的定位和细胞外毒性。研究发现，糖尿病和其他疾病患者的血液中含有高水平的热休克蛋白60。我们将研究翻译后修饰和外泌体在HSP60毒性中的作用。其次，我们将检查膜相关HSP60的来源。SA3 -研究HSP60在重复性损伤和热休克悖论中的作用-热休克反应是保护性的，然而，当热休克反应是在炎症应激后引起的，而不是保护性的，因此会增加损伤。我们发现，HSP60在炎症和热休克后增加，但当这些刺激的顺序相反时则没有增加。HSP60的增加与细胞凋亡增加有关。此外，阻断活化热休克因子（HSF）可减少细胞凋亡。我们将通过选择性敲除模型研究HSF1和hs2在热休克悖论中的作用。HSP60在热休克悖论中的作用将通过检查其细胞定位和操纵其表达来研究。计划中的工作将扩大PI对HSP60及其在心血管炎症和细胞凋亡中的作用的研究，并有可能导致心力衰竭的新治疗方法。

DESCRIPTION (provided by applicant): Previously we have shown that extracellular (ex) heat shock protein (HSP)60 causes cardiac myocyte apoptosis and the synthesis of TNF and IL-1$. Blocking toll-like receptor (TLR)4 decreased, but did not abolish apoptosis, suggesting that the interaction of HSP60 with TLR4 is complex and involves other proteins. Our over-arching hypothesis is that HSP60 can cause apoptosis and inflammation, and this is associated with abnormal expression, distribution or post-translational modification of HSP60. We will expand our investigation in this important area with 3 specific aims designed to further define the role of HSP60 in heart failure and other cardiovascular disease. SA1 - Investigate the mechanism(s) of exHSP60 mediated apoptosis and inflammation. We will extend our investigation of TLR4 in exHSP60 signaling, determine whether, Eritoran, an inhibitor of TLR4, can reduce apoptosis in vitro and in vivo, and further characterize plasma membrane associated HSP60. SA2 - Investigate extracellular HSP60 trafficking and the role of post-translational modification in its toxicity. We hypothesize that post-translational modifications of HSP60 influence its localization and its extracellular toxicity. Studies have found high levels of HSP60 in the blood of patients with diabetes and other diseases. We will investigate the role of post- translational modifications as well as exosomes in the toxicity of this HSP60. Second we will examine the source of membrane associated HSP60. SA3 - Investigate the role of HSP60 in Repetitive Injury and the Heat Shock Paradox - The heat shock response is protective, and yet, when the heat shock response is induced after an inflammatory stress, rather than protection, increased injury occurs, hence. We found that HSP60 is increased after inflammation followed by heat shock, but not when the order of these stimuli is reversed. This increase in HSP60 is associated with increased apoptosis. In addition, blocking activated heat shock factor (HSF) decreased apoptosis. We will investigate the role of HSF1 and 2 in the heat shock paradox with selective knockout models. HSP60's role in the heat shock paradox will be studied by examining its cellular localization and manipulating its expression. The planned work will expand the PI's investigation of HSP60 and its role in cardiovascular inflammation and apoptosis and has the potential to lead to new therapeutic approaches to heart failure. PUBLIC HEALTH RELEVANCE: We have shown that when HSP60 is outside the cell it causes heart cell death. The presence of HSP60 in the blood correlates with cardiovascular disease. We will investigate how HSP60 causes heart cell death, whether a new drug can block heart cell death, and whether changes to HSP60 make it more lethal. Lastly, we will investigate the how HSP60 exacerbates repetitive injury, which is very important in ICU patients and others, but seldom studied. These studies will enhance our understanding of cardiovascular disease.