BACE1 Processing of NRG1 Type III Produces a Myelin-Inducing Signal but Is Not Essential for the Stimulation of Myelination

Myelin sheath thickness is precisely adjusted to axon caliber, and in the peripheral nervous system, neuregulin 1 (NRG1) type III is a key regulator of this process. It has been proposed that the protease BACE1 activates NRG1 dependent myelination. Here, we characterize the predicted product of BACE1-mediated NRG1 type III processing in transgenic mice. Neuronal overexpression of a NRG1 type III-variant, designed to mimic prior cleavage in the juxtamembrane stalk region, induces hypermyelination in vivo and is sufficient to restore myelination of NRG1 type III-deficient neurons. This observation implies that the NRG1 cytoplasmic domain is dispensable and that processed NRG1 type III is sufficient for all steps of myelination. Surprisingly, transgenic neuronal overexpression of full-length NRG1 type III promotes hypermyelination also in BACE1 null mutant mice. Moreover, NRG1 processing is impaired but not abolished in BACE1 null mutants. Thus, BACE1 is not essential for the activation of NRG1 type III to promote myelination. Taken together, these findings suggest that multiple neuronal proteases collectively regulate NRG1 processing. © 2011 Wiley Periodicals, Inc

One Hundred Twenty-One Dystrophin Point Mutations Detected from Stored DNA Samples by Combinatorial Denaturing High-Performance Liquid Chromatography

Duchenne and Becker muscular dystrophies are caused by a large number of different mutations in the dystrophin gene. Outside of the deletion/duplication “hot spots,” small mutations occur at unpredictable positions. These account for about 15 to 20% of cases, with the major group being premature stop codons. When the affected male is deceased, carrier testing for family members and prenatal diagnosis become difficult and expensive. We tailored a cost-effective and reliable strategy to discover point mutations from stored DNA samples in the absence of a muscle biopsy. Samples were amplified in combinatorial pools and tested by denaturing high-performance liquid chromatography analysis. An anomalous elution profile belonging to two different pools univocally addressed the allelic variation to an unambiguous sample. Mutations were then detected by sequencing. We identified 121 mutations of 99 different types. Fifty-six patients show stop codons that represent the 46.3% of all cases. Three non-obvious single amino acid mutations were considered as causative. Our data support combinatorial denaturing high-performance liquid chromatography analysis as a clear-cut strategy for time and cost-effective identification of small mutations when only DNA is available

Antiplatelet Therapy for Non–ST-Segment Elevation Myocardial Infarction in Complex “Real” Clinical Scenarios: A Consensus Document of the “Campania NSTEMI Study Group”

The incidence of ST-segment elevation myocardial infarction (STEMI) has significantly decreased. Conversely, the rate of non-STEMI (NSTEMI) has increased. Patients with NSTEMI have lower short-term mortality compared to patients with STEMI, whereas at long-term follow-up, the mortality becomes comparable. This might be due to the differences in baseline characteristics, including older age and a greater prevalence of comorbidities in the NSTEMI population. Although antithrombotic strategies used in patients with NSTEMI have been well studied in clinical trials and updated guidelines are available, patterns of use and outcomes in clinical practice are less well described. Thus, a panel of Italian cardiology experts assembled under the auspices of the “Campania NSTEMI Study Group” for comprehensive discussion and consensus development to provide practical recommendations, for both clinical and interventional cardiologists, regarding optimal management of antithrombotic therapy in patients with NSTEMI. This position article presents and discusses various clinical scenarios in patients with NSTEMI or unstable angina, including special subsets (eg, patients aged ≥85 years, patients with chronic renal disease or previous cerebrovascular events, and patients requiring triple therapy or long-term antithrombotic therapy), with the panel recommendations being provided for each scenario