Efficacy of PTX3 and posaconazole combination in a rat model of invasive pulmonary aspergillosis.

Posaconazole is currently used for the prophylaxis of invasive pulmonary aspergillosis (IPA). Limitations to posaconazole usage are drug-drug interactions and side effects. PTX3 is an innate immunity glycoprotein with opsonic activity, proven to be protective in IPA animal models. This study investigated the combination of posaconazole with PTX3. The results indicate synergy between PTX3 and posaconazole against aspergillosis, suggesting that a combination of reduced doses of posaconazole with the immune response enhancer PTX3 might represent a treatment option with a higher therapeutic index than posaconazole.

The regulation of synaptic function by alpha-synuclein.

The cytosolic protein alpha-synuclein is enriched at the pre-synaptic terminals of almost all types of neurons in the central nervous system. alpha-Synuclein overexpression and the expression of three different mutants have been shown to sustain the pathogenesis of selected forms of Parkinson's disease. The localization of the protein and the defects found in knocked out or transgenic animals suggest a role of alpha-synuclein in the regulation of synaptic efficiency. However, the precise function of the protein and the molecular mechanisms of its action are still unclear. At synapses the synaptic vesicle release cycle is a finely tuned process composed of sequential steps that require the interconnected participation of several proteins and cytoskeletal elements. Actin microfilaments are required for the regulation of synaptic vesicle mobilization between different functional pools, for their organization at the active zone and influence the exocytotic process. We recently identified actin as a possible target of alpha-synuclein function. Through its binding to actin and the regulation of actin dynamics, alpha-synuclein could participate in the tuning of the vesicle release process, thereby modulating synaptic function and plasticity.

{alpha}-synuclein and its A30P mutant affect actin cytoskeletal structure and dynamics.

The function of alpha-synuclein, a soluble protein abundant in the brain and concentrated at presynaptic terminals, is still undefined. Yet, alpha-synuclein overexpression and the expression of its A30P mutant are associated with familial Parkinson's disease. Working in cell-free conditions, in two cell lines as well as in primary neurons we demonstrate that alpha-synuclein and its A30P mutant have different effects on actin polymerization. Wild-type alpha-synuclein binds actin, slows down its polymerization and accelerates its depolymerization, probably by monomer sequestration; A30P mutant alpha-synuclein increases the rate of actin polymerization and disrupts the cytoskeleton during reassembly of actin filaments. Consequently, in cells expressing mutant alpha-synuclein, cytoskeleton-dependent processes, such as cell migration, are inhibited, while exo- and endocytic traffic is altered. In hippocampal neurons from mice carrying a deletion of the alpha-synuclein gene, electroporation of wild-type alpha-synuclein increases actin instability during remodeling, with growth of lamellipodia-like structures and apparent cell enlargement, whereas A30P alpha-synuclein induces discrete actin-rich foci during cytoskeleton reassembly. In conclusion, alpha-synuclein appears to play a major role in actin cytoskeletal dynamics and various aspects of microfilament function. Actin cytoskeletal disruption induced by the A30P mutant might alter various cellular processes and thereby play a role in the pathogenesis of neurodegeneration.