Defects in AMPAR trafficking and microglia activation underlie socio-cognitive deficits associated to decreased expression of phosphodiesterase 2 a.

Phosphodiesterase 2 A (PDE2A) is an enzyme involved in the homeostasis of cAMP and cGMP and is the most highly expressed PDE in human brain regions critical for socio-cognitive behavior. In cerebral cortex and hippocampus, PDE2A expression level is upregulated in Fmr1-KO mice, a model of the Fragile X Syndrome (FXS), the most common form of inherited intellectual disability (ID) and autism spectrum disorder (ASD). Indeed, PDE2A translation is negatively modulated by FMRP, whose functional absence causes FXS. While the pharmacological inhibition of PDE2A has been associated to its pro-cognitive role in normal animals and in models of ID and ASD, homozygous PDE2A mutations have been identified in patients affected by ID, ASD and epilepsy. To clarify this apparent paradox about the role of PDE2A in brain development, we characterized here Pde2a+/- mice (homozygote animals being not viable) at the behavioral, cellular, molecular and electrophysiological levels. Pde2a+/- females display a milder form of the disorder with reduced cognitive performance in adulthood, conversely males show severe socio-cognitive deficits throughout their life. In males, these phenotypes are associated with microglia activation, elevated glutathione levels and increased externalization of Glutamate receptor (GluR1) in CA1, producing reduced mGluR-dependent Long-term Depression. Overall, our results reveal molecular targets of the PDE2A-dependent pathway underlying socio-cognitive performance. These results clarify the mechanism of action of pro-cognitive drugs based on PDE2A inactivation, which have been shown to be promising therapeutic approaches for Alzheimer's disease, schizophrenia, FXS as well as other forms of ASD.

Role of Phosphodiesterases in Biology and Pathology 2.0.

Phosphodiesterases (PDEs) are ubiquitous enzymes that hydrolyse cAMP and cGMP second messengers temporally, spatially, and integratedly according to their expression and compartmentalization inside the cell [...].

Aortopathy and aortic valve surgery in patients with bicuspid aortic valve with and without raphe.

AIM: To evaluate the association between raphe in bicuspid aortic valve (BAV) patients and valve dysfunction, aortopathy and aortic valve surgery in the REBECCA registry [REgistro della valvola aortica Bicuspide della Società Italiana di ECocardiografia e CArdiovascular Imaging (SIECVI)]. METHODS: Prevalence of aortic valve dysfunction and aortopathy was investigated in BAV patients with and without raphe. Aortic valve dysfunction (regurgitation or stenosis) was categorized as mild, moderate and severe. Aortopathy was defined as annulus ≥14 mm/m2; root ≥20 mm/m2; sinotubular junction ≥16 mm/m2; ascending aorta ≥17 mm/m2, and classified in Type A, isolated ascending aorta dilatation; Type B, aortic root and ascending aorta dilatation; and Type C, isolated aortic root dilatation. RESULTS: Overall, 695 patients with BAV were enrolled; 520 (74.8%) with raphe and 175 (25.2%) without raphe. BAV patients with raphe presented more frequently with moderate or severe aortic stenosis than BAV patients without raphe (183 [35.2%] vs 34 [19.4%], p < 0.001). A higher prevalence of aortopathy, particularly Type B, was observed in patients with vs without raphe. At multivariable analysis, raphe was a predictor of aortic valve surgery at three-year follow-up (odds ratio 2.19, 95% confidence interval 1.08-4.44, p < 0.001). CONCLUSIONS: Patients with BAV and raphe have a higher prevalence of significant aortic stenosis, aortopathy, especially Type B, and a higher risk of undergoing aortic valve surgery at three-year follow-up.