Dutta Subarna, Muraganadan T, Vasudevan Madavan
Department of Biochemistry, University of Calcutta, Kolkata, West Bengal, India.
Theomics International Private Limited, Bengaluru, India.
Cytoskeleton (Hoboken). 2025 Jul;82(7):456-470. doi: 10.1002/cm.21895. Epub 2024 Aug 1.
Most of the single point mutations of the LMNA gene are associated with distinct muscular dystrophies, marked by heterogenous phenotypes but primarily the loss and symmetric weakness of skeletal muscle tissue. The molecular mechanism and phenotype-genotype relationships in these muscular dystrophies are poorly understood. An effort has been here to delineating the adaptation of mechanical inputs into biological response by mutant cells of lamin A associated muscular dystrophy. In this study, we implement engineered smooth and pattern surfaces of particular young modulus to mimic muscle physiological range. Using fluorescence and atomic force microscopy, we present distinct architecture of the actin filament along with abnormally distorted cell and nuclear shape in mutants, which showed a tendency to deviate from wild type cells. Topographic features of pattern surface antagonize the binding of the cell with it. Correspondingly, from the analysis of genome wide expression data in wild type and mutant cells, we report differential expression of the gene products of the structural components of cell adhesion as well as LINC (linkers of nucleoskeleton and cytoskeleton) protein complexes. This study also reveals mis expressed downstream signaling processes in mutant cells, which could potentially lead to onset of the disease upon the application of engineered materials to substitute the role of conventional cues in instilling cellular behaviors in muscular dystrophies. Collectively, these data support the notion that lamin A is essential for proper cellular mechanotransduction from extracellular environment to the genome and impairment of the muscle cell differentiation in the pathogenic mechanism for lamin A associated muscular dystrophy.
LMNA基因的大多数单点突变与不同的肌肉营养不良症相关,其特征为表型异质性,但主要是骨骼肌组织的丧失和对称性无力。这些肌肉营养不良症中的分子机制以及表型-基因型关系尚不清楚。本文旨在通过与核纤层蛋白A相关的肌肉营养不良症的突变细胞来描述机械输入如何转化为生物反应。在本研究中,我们制作了具有特定杨氏模量的工程化光滑表面和图案化表面,以模拟肌肉的生理范围。利用荧光显微镜和原子力显微镜,我们展示了肌动蛋白丝的独特结构,以及突变体中异常扭曲的细胞和细胞核形状,这些突变体显示出偏离野生型细胞的趋势。图案化表面的地形特征会抑制细胞与之结合。相应地,通过对野生型和突变体细胞的全基因组表达数据进行分析,我们报告了细胞粘附结构成分以及LINC(核骨架与细胞骨架连接物)蛋白复合物的基因产物的差异表达。本研究还揭示了突变体细胞中错误表达的下游信号传导过程,当应用工程材料替代传统信号来引导肌肉营养不良症中的细胞行为时,这可能会潜在地导致疾病的发生。总的来说,这些数据支持了这样一种观点,即核纤层蛋白A对于从细胞外环境到基因组的适当细胞机械转导至关重要,并且在与核纤层蛋白A相关的肌肉营养不良症的致病机制中,肌肉细胞分化受损。