Plasmalemma permeability and necroptosis: New targets for intracerebral hemo

描述（由申请人提供）：非创伤性脑出血（ICH）是一个主要的公共卫生问题，缺乏特异性治疗。我们提出了几条线的证据表明，质膜渗透性和坏死有助于胶原酶诱导的小鼠脑出血后的细胞死亡。ICH后，质膜对碘化丙啶（PI）的渗透性是细胞损伤和死亡的关键特征;在TNF α和Fas受体缺陷的小鼠中，ICH后质膜渗透性降低50%;通过EM、组织学和生化标准评估，ICH后发生坏死样细胞死亡; RIPK 3敲除（控制程序性坏死的关键分子）导致ICH后PI+细胞减少。这些初步研究结果强烈表明，坏死性凋亡（由TNF/Fas启动，由RIPK 1和RIPK 3介导）有助于细胞死亡，并可能神经功能障碍，脑出血后。Necrostatins是RIPK 1的小分子抑制剂，其抑制细胞中的坏死性凋亡并防止脑创伤和缺血性中风模型中的细胞死亡和功能缺陷。Kollidon VA 64是FDA批准的药丸制造中的配方成分，可在体内CCI和ICH后重新密封受损细胞。VA 64给药减少了CCI后的血脑屏障损伤、脑水肿、细胞死亡和运动功能障碍，并在小鼠胶原酶ICH后重新密封受损细胞并减少BBB损伤。使用小鼠胶原酶和自体血液ICH模型，我们提出了3个具体目标来检验中心假设，即（1）质膜损伤是ICH后细胞死亡的标志物和介导物，（2）程序性坏死有助于ICH后细胞死亡和功能结局。目的1将使用脉冲标记实验来跟踪损伤细胞在体内的命运，并检验质膜完整性的丧失是ICH后致死性细胞损伤的生物标志物的假设;目的2将检验VA 64恢复质膜完整性、减少继发性损伤并挽救ICH后损伤的脑细胞免于死亡的假设;目的3将使用RIPK 3敲除小鼠和necrostatin以及使用necrostatin加VA 64的转化方法来检验脑出血后坏死性凋亡诱导质膜完整性丧失和细胞死亡的假设。这些目标的完成将确立坏死是ICH的核心，并可能确立VA 64和坏死抑制素作为ICH的新疗法。

DESCRIPTION (provided by applicant): Non-traumatic intracerebral hemorrhage (ICH) is a major public health problem that lacks specific therapy. We present several lines of evidence suggesting that plasmalemma permeability and necrosis contribute to cell death after collagenase induced ICH in mice. Following ICH, plasmalemma permeability to propidium iodide (PI) is a key feature of cellular injury and death; plasmalemma permeability after ICH is reduced by 50% in mice deficient in TNF alpha and Fas receptor; necrotic-like cell death, assessed by EM, histological, and biochemical criteria occurs after ICH; and PI+ cells are reduced after ICH by RIPK3 knockout (a key molecule governing programmed necrosis). These preliminary findings strongly suggest that necroptosis (initiated by TNF/Fas and mediated by RIPK1 and RIPK3) contribute to cell death, and perhaps neurological dysfunction, after ICH. Necrostatins are small molecule inhibitors of RIPK1 that inhibit necroptosis in cells and protect against cell death and functional deficits in brain trauma and ischemic stroke models. Kollidon VA64 is a FDA approved formulary component in pill manufacture that reseals injured cells after CCI and ICH in vivo. VA64 administration reduces blood brain barrier damage, brain edema, cell death, and motor dysfunction after CCI, and reseals injured cells and reduces BBB damage after collagenase ICH in mice. Using mouse collagenase and autologous blood ICH models, we propose 3 specific aims to test the central hypotheses that (1) plasmalemma damage is a marker and mediator of cell death after ICH, and (2) that programmed necrosis contributes to cell death and functional outcome after ICH. Aim 1 will use pulse labeling experiments to follow the fate of injured cells in vivo and test the hypothesis that loss of plasmalemma integrity is a biomarker of fatal cellular injury after ICH; Aim 2 will test the hypothesis that VA64 restores plasmalemma integrity, reduces secondary injury and rescues injured brain cells from death after ICH; Aim 3 will test the hypothesis that necroptosis induces loss of plasmalemma integrity and cell death after ICH, using RIPK3 knockout mice and necrostatins, and a translational approach using necrostatins plus VA64. Completion of these Aims will establish necrosis as central to ICH, and may establish VA64 and necrostatins as novel therapies for ICH.