Generating disease-specific induced pluripotent Stem Cells (iPSCs) in a Biobank facility for genetic disease modelling: the example of Neutral Lipid Storage Disease with Myopathy

The "Galliera Genetic Bank" (GGB) was established in 1983 as a section of the Laboratory of Human Genetics - Galliera Hospital in Genoa. Since then, samples from subjects affected by genetic disorders (and their relatives), or affected by rare diseases, have been collected and stored. The biobank takes advantage of the activity of the laboratory, skilled in pre-natal and post-natal diagnosis of chromosomal and genic disorders and exploits the lab technologies and staff experience to collect samples well characterized by cytogenetic and/or molecular analyses. Since 2008, the biobank is part of the Telethon Network of Biobanks and collaborating with the research infrastructures BBMRI Biobanking and Biomolecular Resources Research Infrastructure (www.bbmri.eu) and in 2011 it has become a new partner of EUROBIOBANK (European Network of DNA, Cell and Tissue banks for Rare Diseases - http://www.eurobiobank.org/). The expertise of the biobank was the staring point to the new activity of Generating disease-specific induced pluripotent Stem Cells (iPSCs) for genetic disease modelling. The example reported is related the Neutral Lipid Storage Disease with Myopathy (NLSD-M) that is a rare autosomal recessive disorder characterized by an abnormal intracellular accumulation of triacylglycerol into cytoplasmic lipid droplets (LDs). In most tissues the lipid droplets (LDs) are cellular organelles for the triacylglycerol storage. LDs metabolic functions are mediated by proteins bound to their surface. In particular, the lipase that catalyzes the removal of the first acyl chain from triacylglycerol is the patatin-like phospholipase domain-containing protein 2 (PNPLA2). This protein is coded by the PNPLA2 gene. PNPLA2 mutations cause the onset of Neutral Lipid Storage Disease with Myopathy. NLSD-M patients are affected by progressive myopathy, cardiomyopathy and hepatomegaly. Other clinical symptoms may include diabetes, chronic pancreatitis and short stature. NLSD-M has, at present, no specific therapy. We have previously reported clinical and genetic findings of some NLSD-M patients and have obtained dermal biopsies from them. Here we report the development of hiPSc (human induced pluripotent stem cell) from patients’ fibroblasts harboring different PNPLA2 mutations. Initial hiPSc colony selection was based on morphologic evaluation and on detection of pluripotency surface markers (SSEA-4 and TRA-1-81). HiPSc also expressed undifferentiated ES cell markers (NANOG, SOX2 and OCT4). Karyotypic analysis of hiPSc lines indicated a normal complement of chromosomes. Immunohystochemical evaluations of LDs on hiPSc revealed that they recapitulate pathological hallmark of the disease. We propose use of differentiated cells derived from hiPSc to study the pathogenetic mechanisms leading to NLSD-M and as a cellular model for therapeutic evaluation.