Skin Research Institute (SRIS), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
Cardiovascular Research Institute (CVRI), Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Nat Commun. 2021 Aug 5;12(1):4722. doi: 10.1038/s41467-021-24849-4.
Mutations in the LaminA gene are a common cause of monogenic dilated cardiomyopathy. Here we show that mice with a cardiomyocyte-specific Lmna deletion develop cardiac failure and die within 3-4 weeks after inducing the mutation. When the same Lmna mutations are induced in mice genetically deficient in the LINC complex protein SUN1, life is extended to more than one year. Disruption of SUN1's function is also accomplished by transducing and expressing a dominant-negative SUN1 miniprotein in Lmna deficient cardiomyocytes, using the cardiotrophic Adeno Associated Viral Vector 9. The SUN1 miniprotein disrupts binding between the endogenous LINC complex SUN and KASH domains, displacing the cardiomyocyte KASH complexes from the nuclear periphery, resulting in at least a fivefold extension in lifespan. Cardiomyocyte-specific expression of the SUN1 miniprotein prevents cardiomyopathy progression, potentially avoiding the necessity of developing a specific therapeutic tailored to treating each different LMNA cardiomyopathy-inducing mutation of which there are more than 450.
laminA 基因突变是单基因扩张型心肌病的常见原因。在这里,我们展示了在诱导突变后 3-4 周内,心肌细胞特异性 laminA 缺失的小鼠会发生心力衰竭并死亡。当将相同的 laminA 突变诱导到 LINC 复合物蛋白 SUN1 基因缺失的小鼠中时,寿命延长至一年以上。通过使用心肌营养性腺相关病毒 9 将显性负性 SUN1 小蛋白转导和表达到 laminA 缺陷型心肌细胞中,也可以破坏 SUN1 的功能。SUN1 小蛋白破坏了内源性 LINC 复合物 SUN 和 KASH 结构域之间的结合,将心肌细胞的 KASH 复合物从核周缘移位,导致寿命至少延长五倍。SUN1 小蛋白在心肌细胞中的特异性表达可防止心肌病的进展,可能避免了开发针对每个不同 LMNA 心肌病诱导突变的特定治疗方法的必要性,目前已经发现了超过 450 种此类突变。