Rock Inhibition as Therapy for Cerebral Cavernous Malformation

描述（申请人提供）：脑海绵体畸形（CCM）是一种常见的出血性血管异常，以散发和家族性常染色体显性形式呈现。它影响了超过一百万的美国人，使他们终生有患中风和癫痫的风险。目前还没有治疗方法来预防CCM病变的发生或临床进展。我们在小鼠中开发了两个CCM家族基因（Ccm1和2）杂合的新型CCM模型，这些模型表现出再现人类疾病的CCM病变。我们的研究小组和其他研究人员认为，RhoA/ROCK信号在杂合子Ccm1和Ccm2小鼠的血管高通透性中起作用。这种高渗透性可以通过ROCK抑制剂法舒地尔或辛伐他汀逆转，辛伐他汀也会影响这一相同的途径。我们提供的证据表明，小鼠病变内皮细胞（EC）和手术切除的人类CCM病变中ROCK活性增加。我们假设异常的RhoA激活是CCM发病的最终原因，因此体内ROCK抑制会抑制病变发展和出血。考虑到两种药物的机制差异和潜在的临床优势，我们建议比较法舒地尔和辛伐他汀选择性抑制Rho的效果。我们进一步假设ROCK抑制会影响相关CCM血管靶点的分子生物标志物和相关基因表达，从而验证了治疗效果。为了验证这些假设，提出了三个目标。在Specific Aim 1中，我们研究了高剂量和低剂量法舒地尔或辛伐他汀对早期和晚期CCM病变负担、出血和表型的影响，并比较了小鼠模型CCM1和2的治疗效果。在Specific Aim 2中，我们研究了高剂量和低剂量法舒地尔或辛伐他汀对体内MRI预先筛选的小鼠CCM病变的影响，包括对病变大小、出血、表型标记物以及ROCK相关基因和相关信号通路的差异表达的影响。在Specific Aim 3中，我们研究了手术切除的人类CCM病变中ROCK激活的生物标志物，通过相关基因表达验证，作为人类治疗的潜在靶点。我们建议比较来自散发性和家族性背景的病变，并与三个已知的人类基因位点进行比较。这种转化策略利用了许多机制发现和最近优化的模型，以开发一种新的可行的治疗CCM的方法。

DESCRIPTION (provided by applicant): The cerebral cavernous malformation (CCM) is a common hemorrhagic vascular anomaly, presenting in sporadic and familial autosomal dominant forms. It affects more than a million Americans, predisposing them to a lifetime risk of stroke and epilepsy. There is currently no therapy to prevent the genesis or clinical progression of CCM lesions. We have developed novel models of CCM in mice heterozygous for two of the CCM familial genes (Ccm1 and 2), and these exhibit CCM lesions recapitulating the human disease. Our group and others have implicated RhoA/ROCK signaling in vascular hyperpermeability in heterozygous Ccm1 and Ccm2 mice. This hyperpermeability can be reversed by the ROCK inhibitor, fasudil, or by simvastatin which also impacts this same pathway. And we provided evidence of increased ROCK activity in endothelial cells (EC) of murine lesions, and in surgically resected human CCM lesions. We hypothesize that aberrant RhoA activation is the ultimate cause of CCM pathogenesis, such that in vivo ROCK inhibition will inhibit lesion development and hemorrhage. We propose to compare the effect of selective ROCK inhibition with fasudil, versus broader Rho inhibition with simvastatin, given mechanistic differences and potential clinical advantages of each drug. We further hypothesize that ROCK inhibition impacts molecular biomarkers and related gene expression in relevant CCM vascular targets, validating the therapeutic effect. Three aims are proposed to test these hypotheses. In Specific Aim 1, we examine the effect of fasudil or simvastatin at high and low doses on CCM lesion burden, hemorrhage and phenotype, with onset of treatment early and later in life, and we compare therapeutic effect in murine models CCM1 and 2. In Specific Aim 2, we examine the effect of high and low doses of fasudil or simvastatin on established murine CCM lesions pre-screened by in vivo MRI, including effects on lesion size, hemorrhage, phenotypic markers, and the differential expression of genes related to ROCK and associated signaling pathways. And in Specific Aim 3 we examine biomarkers of ROCK activation in surgically resected human CCM lesions, validated by correlative gene expression, as a potential target of therapy in man. We propose to compare lesions from sporadic and familial backgrounds, and with each of three known human gene loci. This translational strategy leverages a number of mechanistic discoveries and recently optimized models, to develop a novel and viable therapy for CCM. PUBLIC HEALTH RELEVANCE: There is presently no therapy to reduce the development of cerebral cavernous malformations, nor the significant associated morbidity, despite the fact that more than one million Americans bear these lesions. The recent implication of the RhoA/ROCK pathway in this disease, the existence of well-tolerated drugs that can modulate this pathway, and our development of a useful animal model of the disease create the opportunity to translate these new fundamental insights into a therapeutic strategy for this neurovascular disease.