OPA1 mutations induce mitochondrial DNA instability and optic atrophy ‘plus’ phenotypes

Mutations in OPA1, a dynamin-related GTPase involved in mitochondrial fusion, cristae organization and control of apoptosis, have been linked to non-syndromic optic neuropathy transmitted as an autosomal-dominant trait (DOA). We here report on eight patients from six independent families showing that mutations in the OPA1 gene can also be responsible for a syndromic form of DOA associated with sensorineural deafness, ataxia, axonal sensory-motor polyneuropathy, chronic progressive external ophthalmoplegia and mitochondrial myopathy with cytochrome c oxidase negative and Ragged Red Fibres. Most remarkably, we demonstrate that these patients all harboured multiple deletions of mitochondrial DNA (mtDNA) in their skeletal muscle, thus revealing an unrecognized role of the OPA1 protein in mtDNA stability. The five OPA1 mutations associated with these DOA ‘plus’ phenotypes were all mis-sense point mutations affecting highly conserved amino acid positions and the nuclear genes previously known to induce mtDNA multiple deletions such as POLG1, PEO1 (Twinkle) and SLC25A4 (ANT1) were ruled out. Our results show that certain OPA1 mutations exert a dominant negative effect responsible for multi-systemic disease, closely related to classical mitochondrial cytopathies, by a mechanism involving mtDNA instability

Sintesi ed epossidazione di immino diaziridine

Comunicazione oral

Microreactor-Mediated Organocatalysis: Towards the Development of Sustainable Domino Reactions

Microreactor-mediated organocatalysed Michael reactions have been developed. By using a soluble proline-derived catalyst, Michael-type reactions, leading to γ-nitroketones, have been optimized in homogeneous and continuous-flow conditions. As proof of principle, an integrated microfluidic system able to perform domino processes useful in the preparation of bicyclo[4.4.0]decanes with six contiguous stereogenic centres has been set up

Straightforward access to 4-membered sulfurated heterocycles: introducing a strategy for the single and double functionalization of thietane 1-oxide

A strategy for the stereoselective functionalization of thietane 1-oxide has been developed by using the corresponding organometallic intermediates that reacted with electrophiles leaving intact the 4-membered ring

Soluble urokinase-type Plasminogen Activator Receptor (suPAR) as an independent factor predicting worse prognosis and extra bone marrow involvement in multiple myeloma patients.

The urokinase-type plasminogen activator (uPA) system, which consists of a proteinase (uPA), a receptor (uPAR or CD87) and inhibitors, is involved in proteolysis, cell migration, tissue remodelling, angiogenesis and cell adhesion. Recent findings suggest that malignant plasma cells express uPA and uPAR. The expression of these factors could represent a process by which myeloma plasma cells interact with the bone marrow (BM) environment and influence important biological events such as bone matrix degradation, plasma cell invasion and homing and, possibly, clinical evolution. We evaluated uPAR (CD87) and its soluble form (suPAR) in 49 multiple myeloma (MM) patients and correlated their expression and levels with clinico-biological characteristics of the disease. Flow cytometric analysis demonstrated that CD87 was expressed in all MM patients. High CD87 expression was associated with higher intensity of expression of CD56 (P = 0.038), CD38 (P = 0.058) and CD138 (P = 0.054) and CD45bright positivity (P = 0.014). suPAR levels correlated positively with soluble serum CD138 (P = 0.001), creatinine (P = 0.001), beta2-microglobulin (P < 0.001), disease stage (P = 0.017) and extra-BM involvement (P = 0.002). In the 46 evaluable patients, multivariate analysis showed that high levels of suPAR (P = 0.0214) and disease stage (P = 0.0064) were predictive of extra-BM involvement. In multivariate Cox analysis, 13q deletion (P = 0.0278), high soluble serum CD138 (P = 0.0201) and high suPAR (P = 0.0229) were the only parameters that independently affected survival. We conclude that CD87 is expressed on myeloma plasma cells and that suPAR, which predicts extra-BM involvement and poor prognosis, possibly represents a molecule with a relevant role in the biology of MM