Sphingolipids (SLs) regulate signal transduction pathways involved in several biological processes. Dysregulation of SL metabolism leads to the outburst and progression of diseases, from rare syndromes to disorders of high socio-economic impact. Several enzymes of SL metabolism have been validated as therapeutics targets, including ceramide synthases (CerS), dihydroceramide desaturase (Des1), ceramidases (CDases) and sphingosine-1-phosphate (S1P) lyase (Sgpl1). Therefore, the discovery of compounds able to modulate these enzyme activities is of pharmacologic relevance. Such compounds may arise from library screening, which requires the availability of high throughput screening (HTS) methods, currently very scarce. On the other hand, knowing the molecular mechanisms involved in SL functions may lead to the identification of novel therapeutic targets. This line encompasses the chemical synthesis of small molecules and the study of their role on/as:
1) Cell fate, with special attention to apoptosis, autophagy and cytoplasmic vacuolation processes. Identification of molecular targets involved in the activity of Jaspine B at inducing cytoplasmic vacuolation and methuosis. Biological models include several types of cancer.
2) Pharmacological chaperones of mutated enzymes in rare diseases. Biological models include Niemann-Pick, Gaucher and Farber disease.
3) Cell membrane composition. Biological and biophysical models for the study of infective and cell-cell communication processes.
4) Inhibitors of sphingolipid metabolism with biomedical applications. Structural modifications of natural sphingolipids to design inhibitors or modulators of sphingolipid metabolism.
5) Sphingolipid probes as tools for trafficking and analytical applications. The bioactive molecules of interest are either rationally designed, according to the target protein, or obtained as targeted combinatorial libraries. In this case, the development of high throughput screening (HTS) procedures is required. A general approach is shown below:
Our current interests in this area are addressed at the following targets:
1. Set-up of HTS methods based on novel self-immolative substrates for Sgpl1 (luminogenic S1P analogs) and alkaline ceramidases ACER1 and ACER2 (fluorogenic ceramide analogs).
2. Development of Sgpl1 activity-based probes.
3. To explore the performance of proteolysis targeting chimeras (PROTACS) as modulators of sphingolipid metabolism.