Arterial stiffening and SMC mechanobiology in Hutchinson-Guilford Progeria Syndrome

哈钦森-吉尔福德早衰综合症中的动脉硬化和 SMC 力学生物学

• 批准号: 10368103
• 负责人: Richard Assoian
• 金额: $ 38.39万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-15 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10368103
• 关键词: Abbreviations; Acceleration; Address; Affect; Age; Aorta; Apolipoprotein E; Appearance; Arteries; Atherosclerosis; Blood Pressure; Cardiovascular Diseases; Cardiovascular Pathology; Cell Differentiation process; Cells; Cellular biology; Cessation of life; Characteristics; Child; Cholesterol; Coupling; Data; Defect; Disease; Down-Regulation; Enzymes; Event; Extracellular Matrix; Farnesyl Transferase Inhibitor; Fibronectins; Gene Chips; Gene Expression; Genes; Human; Human Characteristics; In Vitro; Knockout Mice; Lead; Link; LoxP-flanked allele; MYH11 gene; Mechanics; Modeling; Molecular; Mus; Mutation; Myocardial Infarction; Names; Patients; Phenocopy; Phenotype; Premature aging syndrome; Progeria; Property; Protein-Lysine 6-Oxidase; Proteins; Risk Factors; Smooth Muscle; Smooth Muscle Actin Staining Method; Smooth Muscle Myocytes; Stretching; Stroke; Syndrome; Tamoxifen; Teenagers; Testing; Traction Force Microscopy; Transgenic Organisms; Vascular Smooth Muscle; Vasoconstrictor Agents; age related; aged; arterial stiffness; autosomal dominant mutation; cell age; experimental study; human disease; in vivo; in vivo Model; interest; lead candidate; mouse model; mutant; normal aging; novel; osteopontin; premature; rare genetic disorder; response; sex; Abbreviations; Acceleration; Address; Affect; Age; Aorta; Apolipoprotein E; Appearance; Arteries; Atherosclerosis; Blood Pressure; Cardiovascular Diseases; Cardiovascular Pathology; Cell Differentiation process; Cells; Cellular biology; Cessation of life; Characteristics; Child; Cholesterol; Coupling; Data; Defect; Disease; Down-Regulation; Enzymes; Event; Extracellular Matrix; Farnesyl Transferase Inhibitor; Fibronectins; Gene Chips; Gene Expression; Genes; Human; Human Characteristics; In Vitro; Knockout Mice; Lead; Link; LoxP-flanked allele; MYH11 gene; Mechanics; Modeling; Molecular; Mus; Mutation; Myocardial Infarction; Names; Patients; Phenocopy; Phenotype; Premature aging syndrome; Progeria; Property; Protein-Lysine 6-Oxidase; Proteins; Risk Factors; Smooth Muscle; Smooth Muscle Actin Staining Method; Smooth Muscle Myocytes; Stretching; Stroke; Syndrome; Tamoxifen; Teenagers; Testing; Traction Force Microscopy; Transgenic Organisms; Vascular Smooth Muscle; Vasoconstrictor Agents; age related; aged; arterial stiffness; autosomal dominant mutation; cell age; experimental study; human disease; in vivo; in vivo Model; interest; lead candidate; mouse model; mutant; normal aging; novel; osteopontin; premature; rare genetic disorder; response; sex

SUMMARY Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare genetic disease of premature aging caused by an autosomal dominant mutation in LMNA, the gene encoding laminA. The mutant protein, LmnAG608G has been named "Progerin." Children with HGPS typically die in their teenage years as a consequence of CVD (atherosclerosis, myocardial infarction and/or stroke). Remarkably, CVD and death occurs in the absence of high cholesterol, but the arteries of HGPS patients are abnormally stiff, and arterial stiffness has been identified as a cholesterol-independent risk factor for CVD. Moreover, we previously showed that in vivo inhibition of arterial stiffening reduces atherosclerosis in apoE-null mice. Because Progerin is aberrantly farnesylated, therapies for HGPS have focused farnesyltransferase inhibitors (FTIs), but those studies do not directly address the cardiovascular pathology that is thought to trigger early death in HGPS. We recently obtained the LMNAG609G mouse that corresponds to the LMNAG608G mutation in human HGPS and show here that this mouse phenocopies the human disease in showing premature arterial stiffening. Immunostaining of arterial sections and an ECM expression array have identified two lead candidates for this premature arterial stiffening, and those will be studied here. We also found that HGPS arteries are deficient in their response to vasoconstrictors, and our preliminary results link this contractility defect to a striking uncoupling of two well established smooth muscle differentiation/CArG genes: expression of smooth muscle myosin heavy chain (SM-MHC) is reduced in HGPS while smooth muscle actin (SMA) levels are relatively normal. Importantly, we have been able to recapitulate this in vivo phenotype of uncoupled SM-MHC vs. SMA expression in primary smooth muscle cells (SMCs) from WT and HGPS aortas. SM-MHC is among the most important regulators of the high contractility state in differentiated SMCs. Thus, these findings, and related traction force microscopy (TFM) experiments in Preliminary Studies, lead us to a new model for premature arterial stiffening in HGPS: the expression of mutant LaminA (Progerin) leads to a preferential downregulation of SM-MHC, and this locks HGPS SMCs into a novel intermediate tensional state in which they behave more like a de-differentiated SMC, producing ECM proteins and ECM remodeling enzymes that lead to an acceleration of arterial stiffening. Aim 1 will use age-matched WT and HGPS mice to test for causal relationships between i) ECM remodeling events and premature arterial stiffening and ii) SM-MHC expression and arterial ECM remodeling. Aim 2 will use isolated SMCs to identify molecular mechanisms and causal relationships between HGPS, SM-MHC expression, cellular contractility, and ECM remodeling. It will also establish molecular mechanisms by which expression of Progerin, and possibly WT LaminA, affects SM-MHC gene expression. Aim 3 will test for similarities and differences between arterial stiffening, ECM remodeling and SM-MHC/SMA expression in normal aging vs. HGPS.

概括 Hutchinson-Gilford progeria综合征（HGP）是罕见的遗传疾病，是由 LMNA的常染色体显性突变，编码层的基因。突变蛋白LMNAG608G已经 命名为“ progerin”。 HGP的儿童通常在CVD时死于十几岁 （动脉粥样硬化，心肌梗塞和/或中风）。值得注意的是，CVD和死亡发生在没有的情况下 高胆固醇，但HGPS患者的动脉异常僵硬，动脉僵硬一直是 被确定为CVD的胆固醇无关的危险因素。此外，我们以前证明了体内 动脉僵硬的抑制会减少Apoe-null小鼠的动脉粥样硬化。因为孕激素异常 Farnesylate，HGP的疗法已聚焦于Farnesylsylansferase抑制剂（FTI），但这些研究没有 直接解决了被认为会引发HGP早期死亡的心血管病理。 我们最近获得了与人类HGP中的LMNAG608G突变相对应的LMNAG609G小鼠 在这里表明这种小鼠表明人类疾病表现出早产动脉僵硬。 动脉切片和ECM表达阵列的免疫染色已确定了两个铅候选者 过早的动脉僵硬，这些动脉僵硬将在这里进行研究。我们还发现HGP动脉不足 他们对血管收缩剂的反应，我们的初步结果将此收缩性缺陷链接到一个惊人的 两个建立的平滑肌分化/carg基因的解耦合：平滑肌的表达 肌球蛋白重链（SM-MHC）在HGP中降低，而平滑肌肌动蛋白（SMA）水平相对较低 普通的。重要的是，我们已经能够概括这种未偶联的SM-MHC与SMA的体内表型 来自WT和HGP主动脉的原代平滑肌细胞（SMC）的表达。 SM-MHC是最多的 差异化SMC中高收缩状态的重要调节剂。因此，这些发现和相关 初步研究中的牵引力显微镜（TFM）实验，使我们成为了一个新模型 HGP中的动脉僵硬：突变层（雌蛋白）的表达导致优先下调 SM-MHC，这将HGPS SMC锁定到了一种新颖的中间紧张状态，它们的行为更加 像脱不同的SMC一样，产生ECM蛋白和ECM重塑酶，导致 动脉僵硬的加速。 AIM 1将使用年龄匹配的WT和HGP小鼠来测试因果关系 i）ECM重塑事件与过早的动脉僵硬与II）SM-MHC表达之间的关系 和动脉ECM重塑。 AIM 2将使用孤立的SMC识别分子机制和因果关系 HGP，SM-MHC表达，细胞收缩力和ECM重塑之间的关系。它也会 建立分子机制，通过该机制，过程的表达及可能会影响wt薄片，会影响SM-MHC 基因表达。 AIM 3将测试动脉僵硬，ECM重塑之间的相似性和差异 正常衰老与HGPS中的SM-MHC/SMA表达。