(188cs) In silico/in Vitro Combined Study of Lamin a/C Protein Mutations and Their Effects on Biomechanical and Molecular Properties

Authors: 
Laurini, E., University of Trieste
Pricl, S., University of Trieste
Marson, D., University of Trieste
Fermeglia, M., University of Trieste
Boccardo, S., University of Trieste
Sbaizero, O., University of Trieste
Lanzicher, T., University of Trieste
Puzzi, L., University of Trieste
Borin, D., University of Trieste
Chen, S. N., University of Colorado
Mestroni, L., University of Colorado
Long, C. S., University of Colorado
Taylor, M. R. G., University of Colorado
Lee, P., Array BioPharma Inc.
Idiopathic dilated cardiomyopathy (DCM) is a primary disease of the cardiac muscle in which ventricular chamber dilation and systolic dysfunction lead to the so-called ‘pump failure’.1 It is worth to highlight that DCM very frequently is caused by genetic factors,2 among which LaminA/C gene mutantion. Nuclear lamins are the major components of the nuclear lamina, a dense fibrillar network residing in the inner part of the nuclear membrane of the cells. Mutations in the LMNA gene, which encodes the A-type lamins (lamin A and C), cause a consistent number of clinically different syndromes known as laminopathies. Given the clinical impact of LMNA cardiomyopathies, understanding lamin function will fulfill a clinical need and will lead to advancement in the treatment of heart failure. A multidisciplinary approach combining molecular modeling, cell biology and atomic force microscopy (AFM) will be used in this work to analyze the biomechanical properties of human lamin A/C gene (LMNA) mutations (E161K, D192G, N195K). To this purpose, a computational analysis of the human LMNA protein structure and the possible functional differences towards mechanical stresses, in the presence of the 3 different genetic alterations will be performed compared to the wild type protein (Figure 1, left). In parallel, modified biomechanical properties will be assessed using AFM technology (Figure 1, right), in order to support the results obtained by molecular modeling. This approach, together with further molecular biology study on cells expressing the 3 different mutated LMNA will allow us to quantify distinct biomechanical and structural defects in LMNA mutations and correlate the defects with clinical phenotypic severity.

References

[1] Cattin ME, Muchir A, Bonne G. 'State-of-the-heart' of cardiac laminopathies. Curr Opin Cardiol 2013;28:297-304.

[2] Bera M, Ainavarapu SR, Sengupta K. Significance of 1B and 2B domains in modulating elastic properties of lamin A. Sci Rep 2016;6:27879.