Epileptiform Activity and Cognitive Deficits in SNAP-25+/− Mice are Normalized by Antiepileptic Drugs

Synaptosomal-associated protein of 25 kDa (SNAP-25) is a protein that participates in the regulation of synaptic vesicle exocytosis through the formation of the soluble NSF attachment protein receptor complex and modulates voltage-gated calcium channels activity. The Snap25 gene has been associated with schizophrenia, attention deficit hyperactivity disorder, and bipolar disorder, and lower levels of SNAP-25 have been described in patients with schizophrenia. We used SNAP-25 heterozygous (SNAP-25+/−) mice to investigate at which extent the reduction of the protein levels affects neuronal network function and mouse behavior. As interactions of genotype with the specific laboratory conditions may impact behavioral results, the study was performed through a multilaboratory study in which behavioral tests were replicated in at least 2 of 3 distinct European laboratories. Reductions of SNAP-25 levels were associated with a moderate hyperactivity, which disappeared in the adult animals, and with impaired associative learning and memory. Electroencephalographic recordings revealed the occurrence of frequent spikes, suggesting a diffuse network hyperexcitability. Consistently, SNAP-25+/− mice displayed higher susceptibility to kainate-induced seizures, paralleled by degeneration of hilar neurons. Notably, both EEG profile and cognitive defects were improved by antiepileptic drugs. These results indicate that reduction of SNAP-25 expression is associated to generation of epileptiform discharges and cognitive dysfunctions, which can be effectively treated by antiepileptic drug

Morphology of the toe flexor muscles in older people with toe deformities

Objective: Despite suggestions that atrophied, or weak toe flexor muscles are associated with the formation of toe deformities, there has been little evidence to support this theory. This study aimed to determine whether the size of the toe flexor muscles differed in older people with and without toe deformities. Methods: Forty-four older adults (>60 years) were recruited for the study. Each participant had their feet assessed for the presence of hallux valgus or lesser toe deformities. Intrinsic and extrinsic toe flexor muscles were imaged with an ultrasound system using a standardised protocol. Assessor blinded muscle thickness and cross-sectional area was measured using Image J software. Results: Participants with lesser toe deformities (n=20) were found to have significantly smaller quadratus plantae (p=0.003), flexor digitorum brevis (p=0.013), abductor halluces (p=0.004) and flexor halluces brevis (p=0.005) muscles than the participants without any toe deformities (n=19). Female participants with hallux valgus (n=10) were found to have significantly smaller abductor hallucis (p=0.048) and flexor halluces brevis (p=0.013) muscles than the female participants without any toe deformities (n=10; p<0.05). Conclusion: This is the first study to use ultrasound to investigate the size of the toe flexor muscles in older people with hallux valgus and lesser toe deformities compared to otherwise healthy older adults. The size of the abductor hallucis and flexor hallucis brevis muscles were decreased in participants with hallux valgus whereas the quadratus plantae, flexor digitorum brevis, abductor hallucis and flexor halluces brevis muscles were smaller in those participants with lesser toe deformities

Prolactin supplementation to culture medium improves beta-cell survival

OBJECTIVES.: Recent studies demonstrated that prolactin (PRL) has beneficial effects on β cells for islet transplantation. We examined the effect of human recombinant PRL (rhPRL) supplementation to the culture media to determine its potential use in the context of clinical islet transplantation. MATERIALS AND METHODS.: Each human islet isolated from 14 deceased multiorgan donors was cultured in Miami modified media-1 supplemented with or without rhPRL (500 μg/L) for 48 hr. β-Cell survival and proliferation (BrdU and Ki-67) were determined by laser scanning cytometry. The cytoprotective effects of rhPRL against noxious stimuli were assessed by flow cytometry (tetramethylrhodamine ethyl ester). Cytokine/chemokine and tissue factor productions were measured in vitro, and islet potency was assessed in vivo in diabetic immunodeficient mice. RESULTS.: β-Cell survival during culture was 37% higher in the rhPRL group than in control (P=0.029). rhPRL protected β cells in vitro from cytokines, Nitric oxide donor, and H2O 2. The exposure to rhPRL did not affect human β-cell proliferation with our protocol. rhPRL treatment did not alter cytokine/chemokine and tissue factor production in vitro or affected human islet functionality in vivo: recipient mice achieved normoglycemia with a comparable tempo, whereas loss of graft function was observed in two of the seven mice in the control group and in none of the rhPRL group (p=n.s.). CONCLUSION.: rhPRL supplementation to islet culture media improved human β-cell-specific survival without altering islet quality. Addition of rhPRL to cultured islets may grant a more viable β-cell mass in culture. The development of β-cell cytoprotective strategies will be of assistance in improving islet transplantation outcomes

Sox2 Acts in Thalamic Neurons to Control the Development of Retina-Thalamus-Cortex Connectivity

International audienceVisual system development involves the formation of neuronal projections connecting the retina to the thalamic dorso-lateral geniculate nucleus (dLGN) and the thalamus to the visual cerebral cortex. Patients carrying mutations in the SOX2 transcription factor gene present severe visual defects, thought to be linked to SOX2 functions in the retina. We show that Sox2 is strongly expressed in mouse postmitotic thalamic projection neurons. Cre-mediated deletion of Sox2 in these neurons causes reduction of the dLGN, abnormal distribution of retino-thalamic and thalamo-cortical projections, and secondary defects in cortical patterning. Reduced expression, in mutants, of Sox2 target genes encoding ephrin-A5 and the serotonin transport molecules SERT and vMAT2 (important for establishment of thalamic connectivity) likely provides a molecular contribution to these defects. These findings unveil thalamic SOX2 function as a novel regulator of visual system development and a plausible additional cause of brain-linked genetic blindness in humans

Clinical Factors Predicting Tumour Upgrading in Patients Under Active Surveillance and Elected to Active Treatment after Disease Reclassification or Progression

To evaluate clinical factors associated with tumour upgrading (UPG) in low-intermediate risk patients who progressed while under active surveillance (AS) and underwent delayed radical prostatectomy