At the beginning of his research career, he focused his attention on gene-disease identification including: the
Kallmann syndrome gene (involved in axonal orientation), the
OA1 gene (which deals withmelanosomes biogenesis and is mutated in
ocular albinism), the paraplegine gene (which is involved in mitochondrial biology and mutated in
hereditary spastic paraplegia), the
MID1 gene (which is involved in the development of the median line and mutated in the OBB Opitz syndrome). He then focused on identifying the mechanisms underlying rare genetic diseases, particularly regarding
lysosomal storage diseases (LSDs). In this context, he made the discovery of the
Multiple sulfatase deficiency (MSD), in which all members of the sulphatase family (17 in humans) are deficient due to a defect in a post-translational modification. Using an innovative approach, he identified the
SUMF1 (Modification Factor 1 sulphatase) gene, which is responsible for this post-translational modification and is mutated in MSD patients. It has also been shown that the overexpression of SUMF1 significantly increases the activity of exogenous sulphatase in both in vitro and in vivo models. This discovery had immediate clinical application: the SUMF1 gene is currently in use in the production of sulphatase as a tool to improve sulphatase activity for enzymatic replacement therapy. Furthermore, among his major early discoveries, he identified and characterized the Xist gene in human and mice. More recently he focused his attention on lysosomes, the organelles that are responsible for cellular waste degradation. Challenging the conventional knowledge of cellular biology, he hypothesized that lysosome is a dynamic structure subjected to global transcriptional regulation and able to adapt to environmental stimuli. Together with his team, he discovered that lysosomal, autophagy, and exocytotic biosynthesis are transcriptionally regulated by a gene network and controlled by the
TFEB master gene, that promote cellular clearance. This mechanism has been tested in various disease models including: Parkinson's, Alzheimer's, Huntington's disease, lysosomal storage disorders, the
α1-anti-trypsin deficiency and the bulbous
spinal muscular atrophy. This discovery has opened up new possible therapeutic strategies based on the possibility of globally modulating lysosomal function by acting on TFEB gene network. ==Awards==