Tumor Necrosis Factor Modulation of CPCs

这个项目的总体目标是建立病理性之间的机制关系。 炎症与心脏祖细胞(CPC)介导的组织修复。心肌梗塞后(毫升)， CPC数量增加，但不能产生足够的内源性愈合，这表明 微环境损害了它们的修复能力。在左心室重构过程中，有持续的 促炎症细胞因子肿瘤坏死因子-a的阐述。肿瘤坏死因子在心肌梗死后的作用 心脏是异质性的，依赖于它的两个细胞表面受体(TNFR)--TNFR1促进LV 核因子-KB和p38MAPK的重构和激活，而TNFR2则相反 而且是有益的。然而，不同的TNFR特异性效应是否延伸到CPC并调节其 修复能力尚不清楚。在我们的初步研究中，我们发现了一个新的发现，即 抑制CPC的心肌细胞分化，转而促进肾上腺素能表型，从而 加强重塑。这种反应依赖于TNFR1并与核因子-KB相关，并且可以 与TNFR2相反，因此，我们假设通过TNFR1、TNFR2和NF-KB的差异肿瘤坏死因子信号 Plavs在决定肾上腺素能与心肌源性命运的关系中起着关键作用 毫升后的CPC容量。我们提出了三个目标。在目标1中，我们将确定TNFR的影响- 依赖于CPC活性和肾上腺素能与心源性分化信号的体外研究 GFP标记的来自野生型(WT)、TNFR1-/-、TNFR2-/-、显性-阴性(DN)-1KBA的LIN-/c-kit CPC 转基因(Tg)，和Tg-dN-P38A MAPK小鼠心脏。我们还将确定神经肾上腺素能类型 细胞来自心脏，而不是常驻神经前体细胞。在目标2中，我们将描述 活体心脏修复过程中CPC定位的TNFR信号转导。在小鼠再灌流的ML模型中，我们将 GFP标记的Lin-/c-kit WT、TNFR1-/-、TNFR2-/-或TG-dN-KBA CPC，并确定细胞的命运及其 对左心室重构和组织肾上腺素能激活的影响。在目标3中，我们将确定肿瘤坏死因子在 组织微环境对CPC介导的修复和肾上腺素能分化的影响 GFP标记的WT Lin-/c-kit CPC在WT中再灌流m1和TNF-1后的移植反应 /-小鼠，或使用依那西普限制全身肿瘤坏死因子抑制。总的来说，这些研究将：1) 揭示肿瘤坏死因子作为CPC功能的抑制因子和通过TNFR1和NF-1介导的修复的新作用 KB；2)为衰竭心脏中的肾上腺素能细胞定义迄今未知的CPC来源；以及3)靶点 肿瘤坏死因子信号通路提高CPC移植疗效的潜在治疗途径 相关性(请参阅说明)： 这些研究将建立肿瘤坏死因子-a深刻影响的新范式。 心脏祖细胞(CPC)通过其两种受体的不同作用而表现出的行为，并通过这些 对组织修复有利(心脏细胞)或有害(肾上腺素能细胞)的细胞。结果是 将阐明与肿瘤坏死因子信号相关的潜在治疗途径，这些途径既可以提高疗效 外源性祖细胞移植并增强心脏的内在修复能力 心肌梗死在没有祖细胞治疗的情况下。

The overarching objective of this project is to establish the mechanistic relationships between pathological inflammation and cardiac progenitor cell (CPC)-mediated tissue repair. After myocardial infarction (Ml), CPCs are increased in number but fail to produce sufficient endogenous healing, suggesting that factors in the microenvironment compromise their reparative capacity. During LV remodeling, there is sustained elaboration of the pro-inflammatory cytokine tumor necrosis factor-a (TNF). The effects of TNF in the post-MI heart are heterogeneous and depend on its two cell-surface receptors (TNFRs) - TNFRl promotes LV remodeling and activation of nuclear factor (NF)-KB and p38 MAPK, whereas TNFR2 opposes these effects and is beneficial. However, whether divergent TNFR-specific effects extend to CPCs and modulate their reparative capacity is unknown. In our preliminary studies, we have uncovered the novel finding that TNF inhibits cardiomyocyte differentiation of CPCs and instead promotes an adrenergic phenotype that can potentiate remodeling. This response is dependent on TNFR1 and associated with NF-KB, and can be opposed by TNFR2, Hence, we hypothesize that differential TNF signaling via TNFR1, TNFR2, and NF-KB plavs a critical role in determining adrenergic versus cardiomyogenic fate and, conseguentiv, the reparative capacity of CPCs following Ml. We propose three Aims. In Aim 1, we will determine the effects of TNFR- dependent signaling on CPC competence and adrenergic versus cardiogenic differentiation in vitro using GFP-labeled lin-/c-kit+ CPCs from wild-type (WT), TNFRl-/-, TNFR2-/-, dominant-negative (DN)-lKBa transgenic (Tg), and Tg-DN-p38a MAPK mouse hearts. We will also establish that neuroadrenergic-type cells are derived from cardiac and not resident neural progenitors. In Aim 2, we will delineate the role of CPC-localized TNFR-signaling during cardiac repair in vivo. In a murine reperfused Ml model, we will deliver GFP-labeled lin-/c-kit+ WT, TNFR1-/-, TNFR2-/-, or Tg-DN-kBa CPCs and determine cell fate and their effects on LV remodeling and tissue adrenergic activation. In Aim 3, we will determine the effects of TNF in the tissue microenvironment on CPC-mediated repair and adrenergic differentiation by defining remodeling responses upon transplantation of GFP-labeled WT lin-/c-kit+ CPCs following reperfused Ml in WT and TNF- /- mice, or upon circumscribed systemic TNF inhibition with etanercept. Collectively, these studies will: 1) uncover a novel role for TNF as an inhibitor of CPC function and CPC-mediated repair via TNFR1 and NF- KB; 2) define a heretofore unknown CPC-derived origin for adrenergic cells in the failing heart; and 3) target potential therapeutic avenues related to TNF signaling to enhance the efficacy of CPC transplantation RELEVANCE (See instructions): These studies will establish the novel paradigm that tumor necrosis factor-a (TNF) profoundly influences cardiac progenitor cell (CPC) behavior through the divergent effects of its two receptors, and channels these cells toward either beneficial (cardiac cell) or detrimental (adrenergic cell) fates for tissue repair. The results will shed light on potential therapeutic avenues related to TNF signaling that can both enhance the efficacy of exogenous progenitor cell transplantation and augment the heart's intrinsic capacity to repair itself after myocardial infarction in the absence of progenitor cell therapy.