Mutations in lamin A/C gene (LMNA) lead to development of severe disorders – laminopathies. Unlike most other types of intermediate filaments, where the pathological effect of mutations is tightly linked to alteration of mechanical and integrative function, the detailed mechanism of lamin mutations is still unclear and possibly involves the alteration of nuclear signaling and transcriptional process. Since in laminopathies mesenchymal lineage tissues are mostly affected such as myocardium, skeletal muscle, adipose and bone tissues, the role of lamin A/C in differentiation process of mesenchymal stem cells was assumed. The aim of the study was to estimate the effect of LMNA mutations on differentiation of mesenchymal stem cells into muscle, adipose and osteogenic lineages.Methods
In vitro mutagenesis was perfomed on wild type LMNA gene incorporated in a lentiviral vector. Several previously described mutations in LMNA were studied, each associated with a certain phenotype: G232E –myodistrophies, R471C – cardiomyopathies, R482L –lypodistrophies, G465D – myodistrophies and lypodistrophies. Adipose-derived mesenchymal stem cells from healthy donors were transducted with lentiviruses bearing either wild-type or mutant LMNA. Cells were then induced to either muscle, adipose or osteogenic differentiation using standart techniques.Results
Adipose differentiation was markedly decreased in all four mutations and showed 50% for LMNA G232E, 20% for G465D, 5,5% for R471C and 0% for R482L compared to wild type LMNA (100%). Osteogenic differentiation rate was 95,6%for G232E, 70,8% for R471C, 65,0% for R482L and 30,4% for G465D compared to wild type LMNA. Myogenic differentiation was severely reduced in the presence of mutant LMNA with more detailed mechanisms are currently under investigation.Conclusions
Mutations of lamin A/C gene have strong effect on the process of mesenchymal stem cells differentiation into adipose, osteogenic as well as myogenic lineage with several mutations completely abolishing adipose differentiation. We conclude that lamin plays an important role in the process of mesenchymal stem cells differentiation and more detailed mechanisms of its actions will be investigated further.