Growth Arrest Specific 1 (GAS1) is a protein expressed when cells are arrested and during development. When ectopically expressed, GAS1 induces cell arrest and apoptosis of different cell lines, and we have previously demonstrated that the apoptotic process set off by GAS1 is caused by its capacity inhibiting the GDNF-mediated intracellular survival signaling. In the present work, we have dissected the molecular pathway leading to cell death. We employed the SH-SY5Y human neuroblastoma cell line that expresses GAS1 when deprived of serum. We observed, as we have previously described, that the presence of GAS1 reduces RET phosphorylation and inhibits the activation of AKT. We have now determined that the presence of GAS1 also triggers the dephosphorylation of BAD, which, in turn, provokes the release of Cytochrome-c from the mitochondria to the cytosol activating caspase-9, prompting the activity of caspase-3 and resulting in apoptosis of the cells. The apoptotic process is intrinsic, because there is no activation of caspase-8, thus this is consistent with apoptosis induced by the lack of trophic support. Interestingly, in cells where GAS1 has been silenced there is a significant delay in the onset of apoptosis.

Clinical manifestations of coronavirus disease 2019 (COVID-19) in pregnant women are diverse, and little is known of the impact of the disease on placental physiology. Severe acute respiratory syndrome coronavirus (SARS-CoV-2) has been detected in the human placenta, and its binding receptor ACE2 is present in a variety of placental cells, including endothelium. Here, we analyze the impact of COVID-19 in placental endothelium, studying by immunofluorescence the expression of von Willebrand factor (vWf), claudin-5, and vascular endothelial (VE) cadherin in the decidua and chorionic villi of placentas from women with mild and severe COVID-19 in comparison to healthy controls. Our results indicate that: (1) vWf expression increases in the endothelium of decidua and chorionic villi of placentas derived from women with COVID-19, being higher in severe cases; (2) Claudin-5 and VE-cadherin expression decrease in the decidua and chorionic villus of placentas from women with severe COVID-19 but not in those with mild disease. Placental histological analysis reveals thrombosis, infarcts, and vascular wall remodeling, confirming the deleterious effect of COVID-19 on placental vessels. Together, these results suggest that placentas from women with COVID-19 have a condition of leaky endothelium and thrombosis, which is sensitive to disease severity.

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-Objective: To determine the correlations between excessive daytime sleepiness (EDS), assessed by the Epworth sleepiness scale (ESS), and the multiple sleep latency test (MSLT) and nocturnal sleep architecture features, clinical symptoms of narcolepsy (CSN) and subjective sleep quality (SSQ) in patients with narcolepsy. Method: Twenty three untreated patients were studied and compared with a matched control group. Diagnosis of narcolepsy was carried out employing a clinical interview, a polysomnographic (PSG) record, and an MSLT. Results: Subjective number of awakenings was the SSQ indicator that best correlated with EDS (ESS and MSLT). Regarding clinical features, diurnal tiredness and sleep paralysis correlated with ESS values. Increase in ESS was related with decrease in total sleep time, SWS, and sleep onset latency. On the other hand, increase in MSLT was related with decrease in SWS. Conclusion: These data suggest that EDS in patients with narcolepsy could be impaired by disturbed nocturnal sleep.KEy WORDS: narcolepsy, clinical symptoms, subjective sleep quality, sleep architecture, Epworth sleepiness scale, multiple sleep latency test, excessive daytime sleepiness. Correlação entre as características objetivas e subjetivas do sono noturno e a hipersonolência diurna em pacientes narcolepticosResumo -Objetivo: Determinar as correlações entre hipersonolência, avaliada pela escala de sonolência Epworth (ESE) e o teste múltiplo de latência do sono (TMLS) com a arquitetura do sono (AS), sintomas e qualidade subjetiva do sono em pacientes narcolepticos. Método: Comparou-se um grupo de vinte e tres pacientes narcolepticos sem tratamento com grupo controle. O diagnóstico de narcolepsia foi realizado por uma entrevista clinica, polissonografia e o TMLS. Resultados: O número subjetivo de despertares foi o indicador com maior relação com a hipersonolência, o cansaço diurno e a paralisia do sono também foi correlacionados com a ESE.O aumento do índice na ESE foi correlacionado com uma diminuição do tempo total do sono, no sono de ondas lentas (SOL) e com a latência para o início do sono. O incremento na TMLS foi relacionado com diminuição do SOL. Conclusão: Os dados sugerem que a hipersonolência diurna em pacientes portadores de narcolepsia pode se correlacionar com as alterações da arquitetura do sono noturno. PALAVRAS-CHAVE: sintoma clínico de narcolepsia, qualidade subjetiva do sono, teste múltiplo de latência do sono, hipersonolência.

Nitric oxide (NO) is an essential messenger molecule in brain, where it is produced in neurons mostly by the activity of the neuronal isoform of nitric oxide synthase (nNOS). To understand the participation of the different isoforms of NOS in physiological functioning and in pathological processes, mice with null mutations for each of the NOS isoforms have been generated. In the present paper, we report that there is a selective protection from oxidative damage in the brain of mice with a targeted disruption of the nNOS gene. The cerebellum of these mice shows reduced levels of lipid peroxidation (LP) at the different ages tested, compared with wild-type mice, and also a reduction in the formation of reactive oxygen species (ROS). We observed a decrease of LP in cortex, and no effect on either LP or ROS formation was observed in striatum of knockout mice compared with wild type. We also report increased spontaneous motor activity of knockout mice. The expression and activity of nNOS are crucial to maintain redox status in brain, and we consider that the alteration in oxidative damage may help us to explain the phenotypical characteristics of nNOS knockout mice and their differential susceptibility to brain insults.

The overexpression of GAS1 (Growth Arrest Specific 1) in glioma cells induces cell cycle arrest and apoptosis. We previously demonstrated that the apoptotic process set off by GAS1 is caused by its capacity to inhibit the Glial cell-derived neurotrophic factor (GDNF)-mediated intracellular survival signaling pathway. Whereas on the other hand, PTEN is a tumor suppressor, inactive in many tumors, and both GAS1 and PTEN inhibit the PI3K/AKT pathway. Therefore, it is relevant to investigate the potential additive effect of the overexpression of GAS1 and PTEN on tumor growth. In particular, we employed secreted forms of both GAS1 (tGAS1) and PTEN (PTEN-LONG, or PTEN-L) and tested their combined effect on glioma cells. We observed that the co-expression of both the proteins inhibited the growth of U-87 MG human glioblastoma cells more effectively than when independently expressed, and decreased the activity of both AKT and ERK1/2. Interestingly, the combination of the soluble forms was always the most effective treatment. To improve the transfer of tGAS1 and PTEN-L, we employed a lentiviral vector with a p2A peptide-enabled dual expression system that allowed the generation of the two proteins using a single promoter (CMV), in equimolar amounts. The viral vector reduced the growth of U-87 MG cells in vitro and had a striking effect in inhibiting their proliferation after inoculating it into the immunosuppressed mice. The present results support a potential adjuvant role for the combined use of tGAS1 and PTEN-L in the treatment of glioblastoma.

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