Psychometric evaluation of the Basic Psychological Need Satisfaction and Frustration Scale (BPNSFS) in Italy

Two studies were conducted to adapt the Basic Psychological Need Satisfaction and Frustration Scale (BPNSFS) to the Italian context. Results suggest that the BPNSFS can be considered a promising instrument in the context of SDT-based research for investigating satisfaction and frustration of the three basic needs in Italy

Loss-of-function mutations in the X-linked biglycan gene cause a severe syndromic form of thoracic aortic aneurysms and dissections.

Thoracic aortic aneurysm and dissection (TAAD) is typically inherited in an autosomal dominant manner, but rare X-linked families have been described. So far, the only known X-linked gene is FLNA, which is associated with the periventricular nodular heterotopia type of Ehlers-Danlos syndrome. However, mutations in this gene explain only a small number of X-linked TAAD families. We performed targeted resequencing of 368 candidate genes in a cohort of 11 molecularly unexplained Marfan probands. Subsequently, Sanger sequencing of BGN in 360 male and 155 female molecularly unexplained TAAD probands was performed. We found five individuals with loss-of-function mutations in BGN encoding the small leucine-rich proteoglycan biglycan. The clinical phenotype is characterized by early-onset aortic aneurysm and dissection. Other recurrent findings include hypertelorism, pectus deformity, joint hypermobility, contractures, and mild skeletal dysplasia. Fluorescent staining revealed an increase in TGF-β signaling, evidenced by an increase in nuclear pSMAD2 in the aortic wall. Our results are in line with those of prior reports demonstrating that Bgn-deficient male BALB/cA mice die from aortic rupture. In conclusion, BGN gene defects in humans cause an X-linked syndromic form of severe TAAD that is associated with preservation of elastic fibers and increased TGF-β signaling.Genet Med 19 4, 386-395

A Positive Feedback Synapse from Retinal Horizontal Cells to Cone Photoreceptors

Cone photoreceptors and horizontal cells (HCs) have a reciprocal synapse that underlies lateral inhibition and establishes the antagonistic center-surround organization of the visual system. Cones transmit to HCs through an excitatory synapse and HCs feed back to cones through an inhibitory synapse. Here we report that HCs also transmit to cone terminals a positive feedback signal that elevates intracellular Ca2+ and accelerates neurotransmitter release. Positive and negative feedback are both initiated by AMPA receptors on HCs, but positive feedback appears to be mediated by a change in HC Ca2+, whereas negative feedback is mediated by a change in HC membrane potential. Local uncaging of AMPA receptor agonists suggests that positive feedback is spatially constrained to active HC-cone synapses, whereas the negative feedback signal spreads through HCs to affect release from surrounding cones. By locally offsetting the effects of negative feedback, positive feedback may amplify photoreceptor synaptic release without sacrificing HC-mediated contrast enhancement

Covalent and non-covalent interactions of b ig-h3 with collagen VI - big-h3 is covalently attached to the amino-terminal region of collagen VI in tissue microfibrils

© American Society for Biochemistry and Molecular BiologyTransforming growth factor-β induced gene-h3 (β igh3) was found to co-purify with collagen VI microfibrils, extracted from developing fetal ligament, after equilibrium density gradient centrifugation under both nondenaturing and denaturing conditions. Analysis of the collagen VI fraction from the non-denaturing gradient by gel electrophoresis under non-reducing conditions revealed the present of a single high molecular weight band that immunostained for both collagen VI and βigh3. When the fraction was analyzed under reducing conditions, collagen VI αchains and β ig-h3 were the only species evident. The results indicated that βig-h3 is associated with collagen VI in tissues by reducible covalent bonding, presumably disulfide bridges. Rotary shadowing and immunogold staining of the collagen VI microfibrils and isolated tetramers indicated that βigh3 was specifically and periodically associated with the double-beaded region of many of the microfibrils and that this covalent binding site was located in or near the amino-terminal globular domain of the collagen VI molecule. Using solid phase and co-immunoprecipitation assays, recombinant β ig-h3 was found to bind both native and pepsin-treated collagen VI but not individual pepsin-collagen VI chains. Blocking experiments indicated that the major in vitro β ig-h3 binding site was located in the pepsin-resistant region of collagen VI. In contrast to the tissue situation, the in vitro interaction had the characteristics of a reversible non-covalent interaction, and the Kd was measured as 1.63 x 10–8 M. Rotary shadowing of immunogold-labeled complexes of recombinant β ig-h3 and pepsin-collagen VI indicated that the in vitro βig-h3 binding site was located close to the amino-terminal end of the collagen VI triple helix. The evidence indicates that collagen VI may contain distinct covalent and non-covalent binding sites for βigh3, although the possibility that both interactions use the same binding region is discussed. Overall the study supports the concept that βig-h3 is extensively associated with collagen VI in some tissues and that it plays an important modulating role in collagen VI microfibril function.Eric Hanssen, Betty Reinboth and Mark A. Gibso

beta ig-h3 interacts directly with biglycan and decorin, promotes collagen VI aggregation, and participates in ternary complexing with these macromolecules

© 2006 by The American Society for Biochemistry and Molecular Biology, Inc.Recombinant human βig-h3 was found to bind 125I-labeled small leucine-rich proteoglycans (SLRPs), biglycan, and decorin, in co-immunoprecipitation experiments. In each instance the binding could be blocked by an excess of the unlabeled proteoglycan, confirming the specificity of the interaction. Scatchard analysis showed that biglycan bound βig-h3 more avidly than decorin with Kd values estimated as 5.88 x 10–8 and 1.02 x 10–7 M, respectively. In reciprocal blocking experiments both proteoglycans inhibited the others binding to βig-h3 indicating that they may share the same binding site or that the two binding sites are in close proximity on the βig-h3 molecule. Since βig-h3 and the SLRPs are known to be associated with the amino-terminal region of collagen VI in tissue microfibrils, the effects of including collagen VI in the incubations were investigated. Co-immunoprecipitation of 125I-labeled biglycan incubated with equimolar mixtures of βig-h3 and pepsin-collagen VI was increased 6-fold over βig-h3 alone and 3-fold over collagen VI alone. Similar increases were also observed for decorin. The findings indicate that βig-h3 participates in a ternary complex with collagen VI and SLRPs. Static light scattering techniques were used to show that βig-h3 rapidly forms very high molecular weight complexes with both native and pepsin-collagen VI, either alone or with the SLRPs. Indeed βig-h3 was shown to form a complex with collagen VI and biglycan, which appeared to be much more extensive than that formed by βig-h3 with collagen VI and decorin or those formed between the collagen and βig-h3, biglycan, or decorin alone. Biglycan core protein was shown to inhibit the extent of complexing of βig-h3 with native and pepsin-collagen VI suggesting that the glycosaminoglycan side chains of the proteoglycan were important for the formation of the large ternary complexes. Further studies showed that the direct interaction between βig-h3 and biglycan and between biglycan and collagen VI were also important for the formation of these complexes. The globular domains of collagen VI also appeared to have an influence on the interaction of the three components. Overall the results indicate that βig-h3 can differentially modulate the aggregation of collagen VI with biglycan and decorin. Thus this interplay is likely to be important in tissues such as cornea where such complexes are considered to occur.Betty Reinboth, John Thomas, Eric Hanssen and Mark A. Gibso