3-OST-1 Regulation of Antithrombin Isoform Partitioning

描述(申请人提供)：内皮细胞介导的抗炎途径的失调可导致心血管疾病，这是西方世界的头号杀手，以及严重的脓毒症，在美国每年导致22万人死亡。我们的长期目标是阐明内皮细胞的新的抗炎过程，这可能导致对抗严重脓毒症、心脏病发作和中风的新方法。抗凝血酶(AT)是一种血液蛋白，部分通过多种异构体(β-AT、α-AT、L-AT)的存在来预防炎症；然而，抗炎机制尚不清楚。β-AT优先分布于血管壁，被认为具有很高的抗炎活性。因此，特定AT形式的分隔可能会向血管壁传达强烈的抗炎基调。分配也可能有助于增强抗炎AT亚型的稳定性，因为缺乏分配的AT形式是极其短暂的。在生物学上，AT被认为受一种名为HSAT+的内皮细胞成分的调节。然而，目前尚不清楚HSAT+是否参与AT的分区和抗炎活动。我们已经确定HSAT+是血管内皮细胞内化AT所必需的，并试图评估HSAT+和AT内吞作用在AT分区和AT抗炎活性中的作用。我们建议：(1)评价HSAT+在AT抗炎作用中的作用。这将通过研究AT疗法对HSAT+缺乏或野生型小鼠所致感染性休克的疗效来实现。(2)阐明HSAT+介导AT内化的分子机制。将进行细胞生物学实验，以确定AT抗炎信号是否与AT内化的独特途径有关。(3)确定HSAT+在调节不同AT亚型的分配中的作用。为了验证HSAT+是否优先影响具有高抗炎活性的AT亚型的血管分割和寿命，我们将使用新的分子成像技术来跟踪注射到HSAT+缺陷或野生型小鼠体内的AT亚型的分割和命运。总之，这些目的将展示HSAT+的新作用，并为阐明HSAT+介导的AT分配在保护心血管系统的炎症过程中的参与提供基础。外行描述：血管炎症是许多重大疾病的共同特征，如心脏病发作和中风，这些疾病是西方世界的主要杀手。人体通常会抑制血管炎症，我们希望发现参与这一过程的分子。这一发现可能会导致开发新的疗法来对抗血管炎症的破坏性后果。

DESCRIPTION (provided by applicant): Dysregulation of endothelial cell mediated anti-inflammatory pathways can lead to cardiovascular disease, the leading killer in the western world, and severe sepsis, which accounts for 220,000 deaths/year in the United States. Our long term goal is to elucidate novel anti-inflammatory processes of endothelial cells, which may lead to new approaches to combat severe sepsis, heart attack and stroke. Antithrombin (AT) is a blood protein that, in part, prevents inflammation through the existence of multiple isoforms (beta-AT, alpha-AT, L- AT); however, the anti-inflammatory mechanisms are poorly understood. beta-AT preferentially partitions to the blood vessel wall and is considered to exhibit high anti-inflammatory activity. Thus, partitioning of specific AT forms may convey a strong anti-inflammatory tone to the blood vessel wall. Partitioning may also serve to enhance the stability of anti-inflammatory AT isoforms, for AT forms that lack partitioning are extremely short-lived. AT biology is thought to be regulated by an endothelial cells component called HSAT+. However, it is unclear whether HSAT+ is involved in AT partitioning and anti-inflammatory activity. We have determined that HSAT+ is required for endothelial cell internalization of AT and seek to evaluate the involvement of HSAT+ and AT endocytosis in AT partitioning and AT anti-inflammatory activity. We propose to: (1) Evaluate the role of HSAT+ in the anti-inflammatory activity of AT. This will be accomplished by studying the efficacy of AT therapy in treating septic shock induced in HSAT+ deficient or wild-type mice. (2) Elucidate molecular mechanisms by which HSAT+ mediates AT internalization. Cell biologic experiments will be conducted to determine if AT anti-inflammatory signaling is associated with a unique pathway of AT internalization. (3) Establish the role of HSAT+ in regulating the partitioning of distinct AT isoforms. To examine if HSAT+ preferentially influences the vascular partitioning and longevity of AT forms with high anti-inflammatory activity, we shall use novel molecular imaging techniques to follow the partitioning and fate of AT isoforms injected into HSAT+ deficient or wild-type mice. Together, these Aims will demonstrate novel roles for HSAT+ and provide foundations for elucidating the involvement of HSAT+ mediated AT partitioning in protecting against inflammatory processes of the cardiovascular system. Lay description: Vascular inflammation is a common denominator of numerous major diseases, such as heart attack and stroke, which are the leading killers in the western world. The body normally inhibits vascular inflammation and we wish to discover molecules involved in this processes. Such a discovery could lead to the development of novel therapeutics to combat the devastating consequences of vascular inflammation.