Sonic Hedgehog pathway is upregulated in adamantinomatous craniopharyngiomas

OBJECTIVES

Pituitary stem cells play a role in the oncogenesis of human adamantinomatous craniopharyngiomas (aCPs). We hypothesized that crosstalk between the Wnt/β-catenin and Sonic Hedgehog (SHH) pathways, both of which are important in normal pituitary development, would contribute to the pathogenesis of aCPs.

DESIGN

To explore the mRNA and protein expression of components of the SHH signaling pathway in aCPs and their relationship with the identification of CTNNB1/β-catenin mutations and patients outcomes.

PATIENTS AND METHODS

In 18 aCP samples, CTNNB1 was sequenced, and the mRNA expression levels of SHH pathway members (SHH, PTCH1, SMO, GLI1, GLI2, GLI3, and SUFU) and SMO, GLI1, GLI3, SUFU, β-catenin, and Ki67 proteins were evaluated by quantitative real-time PCR and immunohistochemistry respectively. Anterior normal pituitaries were used as controls. Associations between molecular findings and clinical data were analyzed.

RESULTS

The aCPs presented higher mRNA expression of SHH (+400-fold change (FC); P<0.01), GLI1 (+102-FC; P<0.001), and GLI3 (+5.1-FC; P<0.01) than normal anterior pituitaries. Longer disease-free survival was associated with low SMO and SUFU mRNA expression (P<0.01 and P=0.02 respectively). CTNNB1/β-catenin mutations were found in 47% of the samples. aCPs with identified mutations presented with higher mRNA expression of SMO and GLI1 (+4.3-FC; P=0.02 and +10.2-FC; P=0.03 respectively). SMO, GLI1, GLI3, and SUFU staining was found in 85, 67, 93, and 64% of the samples respectively. Strong GLI1 and GLI3 staining was detected in palisade cells, which also labeled Ki67, a marker of cell proliferation.

CONCLUSIONS

The upregulation of SHH signaling occurs in aCPs. Thus, activation of Wnt/β-catenin and SHH pathways, both of which are important in pituitary embryogenesis, appears to contribute to the pathogenesis of aCP.

Thirteen years experience with selective screening for disorders in purine and pyrimidine metabolism

Purine and pyrimidine disorders represent a heterogeneous group with variable clinical symptoms and low prevalence rate. In the last thirteen years, we have studied urine/plasma specimens from about 1600 patients and we have identified 35 patients: eight patients with adenylosuccinate lyase deficiency, eight patients with hypoxanthine-guanine phosphoribosyltransferase deficiency, one patient with purine nucleoside phosphorylase deficiency, ten patients with xanthine dehydrogenase deficiency, six patients with molybdenum cofactor deficiency and two patients with dihydropyrimidine dehydrogenase deficiency. Despite low incidence of these diseases, our findings highlight the importance of including the purine and pyrimidine analysis in the selective screening for inborn errors of metabolism in specialized laboratories, where amino acid and organic acid disorders are simultaneously investigated.

[Beneficial effect of preferred music on cognitive functions in minimally conscious state patients]

Several studies have shown that music can boost cognitive functions in normal and brain-damaged subjects. A few studies have suggested a beneficial effect of music in patients with a disorder of consciousness but it is difficult to conclude since they did not use quantified measures and a control condition/group. The aim of the present study was to compare the effect of music to that of a continuous sound on the relational behavior of patients in a minimally conscious state (MCS). Behavioral responses of six MCS patients were evaluated using items from the Coma Recovery Scale-Revised. Weekly evaluation sessions were carried out, over four weeks, under two conditions: following the presentation of either the patient's preferred music, or following a continuous sound (control condition). Qualitative and quantitative analyses showed that twelve of the eighteen sessions (66.6%) showed a better result for the music condition than for the control condition. This new protocol suggests that preferred music has a beneficial effect on the cognitive abilities of MCS patients. The results further suggest that cerebral plasticity may be enhanced in autobiographical (emotional and familiar) contexts. These findings should now be further extended with an increased number of patients to further validate the hypothesis of the beneficial effect of music on cognitive recovery.

Pattern-wavelength coarsening from topological dynamics in silicon nanofoams

We report the experimental observation of a submicron cellular structure on the surface of silicon targets eroded by an ion plasma. Analysis by atomic force microscopy allows us to assess the time evolution and show that the system can be described quantitatively by the convective Cahn-Hilliard equation, found in the study of domain coarsening for a large class of driven systems. The space-filling trait of the ensuing pattern relates it to evolving foams. Through this connection, we are actually able to derive the coarsening law for the pattern wavelength from the nontrivial topological dynamics of the cellular structure. Thus, the study of the topological properties of patterns in nonvariational spatially extended systems emerges as complementary to morphological approaches to their challenging coarsening properties.

Chronic stress mediators act synergistically on colonic nociceptive mouse dorsal root ganglia neurons to increase excitability

BACKGROUND

Stress hormones can signal to colonic dorsal root ganglia (DRG) neurons and may play a role in sustained hyperexcitability of nociceptors.

METHODS

Mouse DRG neurons were exposed overnight to epinephrine (Epi) 5 nM and/or corticosterone (Cort) 1 μM or prior water-avoidance stress. Patch clamp recordings, visceromotor reflexes (VMRs) and molecular studies were conducted.

KEY RESULTS

Water-avoidance stress induced neuronal hyperexcitability. Incubation of DRG neurons in both Cort and Epi (but neither alone) induced hyperexcitability (rheobase decreased 51%, p < 0.05; action potential discharge increased 95%, p < 0.01); this was blocked by antagonists of the β2 adrenoreceptor (butoxamine, But) and Cort receptor (mifepristone) in combination or alone. Stress hormones enhanced voltage-gated Nav 1.7 currents (p < 0.05) and suppressed IA (p < 0.0001) and IK+ (p < 0.05) currents. Furthermore, stress hormones increased DRG β2 adrenoreceptor mRNA (59%, p = 0.007) and protein (125%, p < 0.05), also Nav 1.7 transcript (45%, p = 0.004) and protein (114%, p = 0.002). In whole-animal studies, the WAS hyperexcitability of DRG neurons was blocked by antagonists of the β2 and glucocorticoid receptors (GCR) but together they paradoxically increased VMRs to colorectal balloon distension.

CONCLUSIONS & INFERENCES

Stress mediators Epi and Cort activate β2 and GCR on DRG neurons which synergistically induce hyperexcitability of nociceptive DRG neurons and cause corresponding changes in voltage-gated Na(+) and K(+) currents. Furthermore, they increase the expression of β2 adrenoreceptors and Nav1.7 channels, suggesting transcriptional changes could contribute to sustained signaling following stress. The paradoxical effects of But and mifepristone in electrophysiological compared to VMR testing may reflect different peripheral and central actions on sensory signaling.

Sexual reproduction of the pentaploid, short-styled Oxalis pes-caprae allows the production of viable offspring

Reproduction is a key factor for the successful establishment and spread of introduced species. Oxalis pes-caprae is a tristylous species with a self- and morph-incompatibility sexual system that, in the invaded range of the western Mediterranean Basin, has been found to reproduce asexually because only the pentaploid, short-styled morph (5x S-morph) was introduced. The objective of this study was to test the ability of the 5x S-morph of O. pes-caprae to produce viable offspring in the absence of compatible mates, exploring the hypothesis that new morphs could have emerged by sexual reproduction events of the initially introduced morph. Pollen germination, pollen tube development, fruit and seed production, seed germination and offspring ploidy levels were analysed after controlled hand-pollinations to assess self- and morph-incompatibility and production of viable gametes by the 5x S-morph. The self-incompatibility system is still operating, but a partial breakdown in the morph-incompatibility system combined with the production of viable gametes was observed, allowing sexual reproduction of the 5x S-morph in the invaded range. The ability of the 5x S-morph to reproduce sexually may have major consequences for the dynamics of invasive populations of O. pes-caprae and could be one of the factors involved in the occurrence of new floral morphs in this invaded range.