THIS IS A SYNTHESIS OF THE PROJECT, TRASLATED FROM THE ORIGINAL ITALIAN VERSION

Correction of mutations in LMNA or EMD genes in cells coming from patients with Emery-Dreifuss Muscular Dystrophy using CRISPR/Cas9 technology: towards a more effective treatment

Emery-Dreifuss Muscular Dystrophy is a degenerative disease affecting skeletal and cardiac muscle tissue, resulting in their progressive weakening, with reduced motor capacity and cardiac function. 

There are seven forms of Emery-Dreifuss Muscular Dystrophy (EDMD). The most common form is EDMD1, caused by mutations in the EMD gene, which encodes a protein called emerin; and the EDMD2, caused by mutations in the LMNA gene that encodes the proteins lamin A and lamin C. The clinical phenotype of these forms of the disease is basically the same. 

There is also a very similar form of disease, LGMD1B, which can be caused by mutation on LMNA gene. 

Furthermore many forms of dilated cardiomyopathy with conduction defects are caused by mutations in the LMNA gene. The weakening of the heart is a risk of sudden death, resulting in the need for the implantation of a defibrillator. The latter, however, does not always spare the patient from sudden death. Those explained are very relevant aspects of this disease.

Almost all EDMD1 patients are carriers of non-sense mutations of the EMD gene, leading to the absence of emerin. Emerin is a protein located in the nuclear membrane that structurally and functionally interacts with lamin A/C. On the contrary, patients with EDMD2 have missense mutations in the LMNA gene, which lead to the expression of an apparently normal, but not functioning, protein. Mutations at any point of the LMNA gene cause a disease, not only EDMD2, but also diseases affecting the adipose tissue, nerves, bone tissue, metabolic diseases and progeria. 

The lamin A/C and the emerin constitute the nuclear envelope of the cell and their structural and functional interaction is essential for the functioning of the muscular cells. In cultures of EDMD cells, whether these are carriers of LMNA or EMD mutations, the nuclear envelope appears altered in a good percentage of cells, acquiring a honeycomb appearance. This condition is a good marker of the genetic defect. 

CRISPR/Cas9 technology allows the use of specific enzymes to perform a cutting and sewing action capable of eliminating portions of a gene and/or replacing them with different portions.

In the case of EDMD1, CRISPR/Cas9 technology could eliminate the STOP signal that prevents the production of emerin. In this case, the efficiency of the technique would be easily verifiable by evaluating the presence of emerin in cells of EDMD1 patients. 

In the case of EDMD2, since it is a dominant disease, that is a disease in which some cells produce the working protein, CRISPR/Cas9 technology would eliminate the mutation of the modified lamin A/C lamina. This would eliminate the toxic effect of the mutated protein and lead to a higher expression of a working lamin A/C. 

DURATION OF THE PROJECT: 2 YEARS 

TOTAL COST: € 107,800

PROJECT MANAGERS      

• Dr. Alessandra Recchia, Center for Regenerative Medicine, University of Modena e Reggio Emilia
• Dr. Giovanna Lattanzi, CNR Molecular Genetics Institute, University of Bologna 

INVOLVED CENTERS      

• Dr. Lorenzo Maggi, Carlo Besta Neurological Institute, Milan
• Dr. Chiara Fiorillo, Giannina Gaslini Institute, Genoa