Role of PATJ in stroke prognosis by modulating endothelial to mesenchymal transition through the Hippo/Notch/PI3K axis.

Through GWAS studies we identified PATJ associated with functional outcome after ischemic stroke (IS). The aim of this study was to determine PATJ role in brain endothelial cells (ECs) in the context of stroke outcome. PATJ expression analyses in patient's blood revealed that: (i) the risk allele of rs76221407 induces higher expression of PATJ, (ii) PATJ is downregulated 24 h after IS, and (iii) its expression is significantly lower in those patients with functional independence, measured at 3 months with the modified Rankin scale ((mRS) ≤2), compared to those patients with marked disability (mRS = 4-5). In mice brains, PATJ was also downregulated in the injured hemisphere at 48 h after ischemia. Oxygen-glucose deprivation and hypoxia-dependent of Hypoxia Inducible Factor-1α also caused PATJ depletion in ECs. To study the effects of PATJ downregulation, we generated PATJ-knockdown human microvascular ECs. Their transcriptomic profile evidenced a complex cell reprogramming involving Notch, TGF-ß, PI3K/Akt, and Hippo signaling that translates in morphological and functional changes compatible with endothelial to mesenchymal transition (EndMT). PATJ depletion caused loss of cell-cell adhesion, upregulation of metalloproteases, actin cytoskeleton remodeling, cytoplasmic accumulation of the signal transducer C-terminal transmembrane Mucin 1 (MUC1-C) and downregulation of Notch and Hippo signaling. The EndMT phenotype of PATJ-depleted cells was associated with the nuclear recruitment of MUC1-C, YAP/TAZ, ß-catenin, and ZEB1. Our results suggest that PATJ downregulation 24 h after IS promotes EndMT, an initial step prior to secondary activation of a pro-angiogenic program. This effect is associated with functional independence suggesting that activation of EndMT shortly after stroke onset is beneficial for stroke recovery.

NOTCH1 Gene as a Novel Cause of Thoracic Aortic Aneurysm in Patients with Tricuspid Aortic Valve: Two Cases Reported.

Thoracic aortic aneurysms (TAA) consist of abnormal dilation or the widening of a portion of the ascending aorta, due to weakness or destructuring of the walls of the vessel and are potentially lethal. The congenital bicuspid aortic valve (BAV) is considered a risk factor for the development of TAA because asymmetric blood flow through the bicuspid aortic valve detrimentally influences the wall of the ascending aorta. NOTCH1 mutations have been associated with non-syndromic TAAs as a consequence of BAV, but little is known regarding its haploinsufficiency and its relationship with connective tissue abnormalities. We report two cases in which there is clear evidence that alterations in the NOTCH1 gene are the cause of TAA in the absence of BAV. On the one hand, we describe a 117 Kb deletion that includes a large part of the NOTCH1 gene and no other coding genes, suggesting that haploinsufficiency can be considered a pathogenic mechanism for this gene associated with TAA. In addition, we describe two brothers who carry two variants, one in the NOTCH1 gene and another in the MIB1 gene, corroborating the involvement of different genes of the Notch pathway in aortic pathology.

Screening for Prognostic microRNAs Associated with Treatment Failure in Diffuse Large B Cell Lymphoma.

Diffuse large B cell lymphoma (DLBCL) treatment with R-CHOP regimen produces 5-year progression-free survival and overall survival of around 60-70%. Our objective was to discover prognostic biomarkers allowing early detection of the remaining 30-40% with poor long-term outcome. For this purpose, we applied a novel strategy: from a cohort of DLBCL patients, treated with standard therapy, a discovery group of 12 patients with poor prognosis (advanced stage III-IV, R-IPI > 2) was formed, consisting of six chemoresistant (refractory/early relapse < 12 months) and six chemosensitive (complete remission > 3 years) subjects. By using microarray assays, the most differentially expressed miRNAs were defined as an initial set of prognostic miRNA candidates. Their expression was then analyzed in a validation cohort of 68 patients and the three miRNAs with the most significant impact on event-free and overall survival were selected. In the DLBCL cell line U-2932 the transfection with miR-1244 and miR-193b-5p, but not miR-1231, blocked the effect of CHOP on cell viability. A subsequent gene set enrichment analysis in patients revealed the implication of the first two miRNAs in cell cycle control and chemoresistance-related pathways, whereas the last one was involved in immunological processes. In conclusion, this novel strategy identified three promising prognostic markers for DLBCL patients at high risk of failure with standard therapy.

Familial Psychosis Associated With a Missense Mutation at MACF1 Gene Combined With the Rare Duplications DUP3p26.3 and DUP16q23.3, Affecting the CNTN6 and CDH13 Genes.

Psychosis is a highly heritable and heterogeneous psychiatric condition. Its genetic architecture is thought to be the result of the joint effect of common and rare variants. Families with high prevalence are an interesting approach to shed light on the rare variant's contribution without the need of collecting large cohorts. To unravel the genomic architecture of a family enriched for psychosis, with four affected individuals, we applied a system genomic approach based on karyotyping, genotyping by whole-exome sequencing to search for rare single nucleotide variants (SNVs) and SNP array to search for copy-number variants (CNVs). We identified a rare non-synonymous variant, g.39914279 C > G, in the MACF1 gene, segregating with psychosis. Rare variants in the MACF1 gene have been previously detected in SCZ patients. Besides, two rare CNVs, DUP3p26.3 and DUP16q23.3, were also identified in the family affecting relevant genes (CNTN6 and CDH13, respectively). We hypothesize that the co-segregation of these duplications with the rare variant g.39914279 C > G of MACF1 gene precipitated with schizophrenia and schizoaffective disorder.

Detection of the EGFR G719S Mutation in Non-small Cell Lung Cancer Using Droplet Digital PCR.

Objectives: The main objectives of the study were (1) to set-up a droplet digital PCR (ddPCR) assay for the non-invasive detection of G719S EGFR mutation in NSCLC patients; (2) to determine the limits of detection of the ddPCR assay for G719S mutation and (3) to compare COBAS® and ddPCR System for G719S quantification in plasma. Materials and Methods: Blood samples were collected from 22 patients diagnosed with advanced NSCLC. Then, plasma ctDNA was extracted with the Qiagen Circulating Nucleic Acids kit and quantified by QuantiFluor® dsDNA System. The mutational study of EGFR was carried out by digital droplet PCR (ddPCR) with the QX200 Droplet Digital PCR System with specific probes and primers. Results: We observed the lowest percentage of G719S mutant allele could be detected in a wildtype background was 0.058%. In the specificity analysis, low levels of G719S mutation were detected in healthy volunteers with a peak of 21.65 mutant copies per milliliter of plasma and 6.35 MAFs. In those patients whose tissue biopsy was positive for G719S mutation, mutant alleles could also be detected in plasma using both ddPCR and COBAS® System. Finally, when mutational status was studied using both genotyping techniques, higher mutant copies/ml and higher mutant allele fraction (MAF) correlated with higher Semiquantitative Index obtained by COBAS®. Conclusions: Although tissue biopsies cannot be replaced due to the large amount of information they provide regarding tumor type and structure, liquid biopsy and ddPCR represents a new promising strategy for genetic analysis of tumors from plasma samples. In the present study, G719S mutation was detected in a highly sensitive manner, allowing its monitorization with a non-invasive technique.

Eosinophilic COPD Patients Display a Distinctive Serum miRNA Profile From Asthma and Non-eosinophilic COPD / Los pacientes con EPOC eosinofílica presentan un perfil de miRNA en suero diferente a los asmáticos y EPOC no eosinofílicos

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) are common chronic airway diseases that may overlap in some individuals. Asthma COPD overlap (ACO) is a heterogeneous conditions that includes smoking-asthma (SA) and COPD with eosinophilia (COPDe). MicroRNAs (miRNA) are regulators of gene expression with a great potential as biomarkers. OBJECTIVES: The objective of this study was to identify distinctive miRNA signatures in patients from the whole spectrum of chronic obstructive bronchial disease (SA, COPDe, non-smoking asthmatics (NSA), and COPD) that could serve as diagnostic biomarkers or describe differential molecular mechanisms with potential therapeutic implications. METHODS: From a previously characterized cohort of ACO, COPD and asthma patients, we selected a discovery group of 40 patients for miRNA expression profiling by means of microarray technology. Differential expression of miRNAs were validated by quantitative PCR in the complete cohort (n = 274). RESULTS: Thirty differentially expressed miRNAs (eBAYES p < 0.05, fold change ≥ 2) were found among the different groups of patients regarding COPDe: 19 COPD-vs-COPDe, 13 NSA-vs-COPDe, 11 SA-vs-COPDe. A characteristic down-regulated miRNA expression pattern was identified in COPDe patients. Differential expression of miR-619-5p and miR-4486 in COPDe patients were validated in the complete cohort (n = 274). Conclusions: We postulate that COPDe patients show a characteristic expression profile of miRNAs distinctive from asthma and COPD. Also that SA and COPDe patients, which have been typically clustered in the ACO group, display distinct molecular events

ANTECEDENTES: El asma y la enfermedad pulmonar obstructiva crónica (EPOC) son enfermedades crónicas comunes de la vía aérea y pueden solaparse en algunos individuos. El solapamiento de asma y EPOC (ACO, por sus siglas en inglés) es una enfermedad heterogénea que incluye el asma en fumadores (AF) y la EPOC con eosinofilia (EPOCe). Los microRNA (miRNA) son reguladores de la expresión de genes con gran potencial para su uso como biomarcadores. OBJETIVOS: El objetivo de este estudio fue identificar las firmas características de miRNA en pacientes del espectro de enfermedades pulmonares obstructivas crónicas al completo (AF, EPOCe, asmáticos no fumadores y EPOC) que pudieran servir como biomarcadores diagnósticos o describir mecanismos moleculares diferenciales con potenciales implicaciones terapéuticas. MÉTODOS: A partir de una cohorte previamente caracterizada de pacientes con ACO, EPOC y asma, seleccionamos un grupo de descubrimiento de 40 pacientes para realizar sus perfiles de expresión de miRNA mediante microarrays. La expresión diferencial de miRNA se validó mediante PCR cuantitativa en la cohorte completa (n = 274). RESULTADOS: Se encontraron 30 miRNA expresados diferencialmente (eBayes p < 0,05, fold change [cambio en incremento] ≥ 2) entre los diferentes grupos de pacientes en relación con la EPOCe: 19 EPOC comparado con EPOCe, 13 asmáticos no fumadores comparado con EPOCe, 11 AF comparado con EPOCe. Se identificó un patrón característico de expresión con regulación a la baja de miRNA. La expresión diferencial de miR-619-5p y miR-4486 en los pacientes con EPOCe se validó con la cohorte al completo (n = 274). CONCLUSIONES: Postulamos que los pacientes con EPOCe muestran un perfil de expresión de miRNA característico y diferente al del asma y la EPOC. También que los pacientes con AF y con EPOCe, que se han agrupado típicamente en el grupo de ACO, muestran eventos moleculares diferenciales

Eosinophilic COPD Patients Display a Distinctive Serum miRNA Profile From Asthma and Non-eosinophilic COPD.

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) are common chronic airway diseases that may overlap in some individuals. Asthma COPD overlap (ACO) is a heterogeneous conditions that includes smoking-asthma (SA) and COPD with eosinophilia (COPDe). MicroRNAs (miRNA) are regulators of gene expression with a great potential as biomarkers. OBJECTIVES: The objective of this study was to identify distinctive miRNA signatures in patients from the whole spectrum of chronic obstructive bronchial disease (SA, COPDe, non-smoking asthmatics (NSA), and COPD) that could serve as diagnostic biomarkers or describe differential molecular mechanisms with potential therapeutic implications. METHODS: From a previously characterized cohort of ACO, COPD and asthma patients, we selected a discovery group of 40 patients for miRNA expression profiling by means of microarray technology. Differential expression of miRNAs were validated by quantitative PCR in the complete cohort (n=274). RESULTS: Thirty differentially expressed miRNAs (eBAYES p<0.05, fold change ≥2) were found among the different groups of patients regarding COPDe: 19 COPD-vs-COPDe, 13 NSA-vs-COPDe, 11 SA-vs-COPDe. A characteristic down-regulated miRNA expression pattern was identified in COPDe patients. Differential expression of miR-619-5p and miR-4486 in COPDe patients were validated in the complete cohort (n=274). CONCLUSIONS: We postulate that COPDe patients show a characteristic expression profile of miRNAs distinctive from asthma and COPD. Also that SA and COPDe patients, which have been typically clustered in the ACO group, display distinct molecular events.

Can the Macrogeometry of Dental Implants Influence Guided Bone Regeneration in Buccal Bone Defects? Histomorphometric and Biomechanical Analysis in Beagle Dogs.

The aim of this experimental animal study was to assess guided bone regeneration (GBR) and implant stability (ISQ) around two dental implants with different macrogeometries. Forty eight dental implants were placed within six Beagle dogs. The implants were divided into two groups (n = 24 per group): G1 group implants presented semi-conical macrogeometry, a low apical self-tapping portion, and an external hexagonal connection (whereby the cervical portion was bigger than the implant body). G2 group implants presented parallel walls macrogeometry, a strong apical self-tapping portion, and an external hexagonal connection (with the cervical portion parallel to the implant body). Buccal (mouth-related) defects of 2 mm (c2 condition) and 5 mm (c3 condition) were created. For the control condition with no defect (c1), implants were installed at crestal bone level. Eight implants in each group were installed under each condition. The implant stability quotient (ISQ) was measured immediately after implant placement, and on the day of sacrifice (3 months after the implant placement). Histological and histomorphometric procedures and analysis were performed to assess all samples, measuring crestal bone loss (CBL) and bone-to-implant contact (BIC). The data obtained were compared with statistical significance set at p < 0.05. The ISQ results showed a similar evolution between the groups at the two evaluation times, although higher values were found in the G1 group under all conditions. Within the limitations of this animal study, it may be concluded that implant macrogeometry is an important factor influencing guided bone regeneration in buccal defects. Group G1 showed better buccal bone regeneration (CBL) and BIC % at 3 months follow up, also parallel collar design can stimulate bone regeneration more than divergent collar design implants. The apical portion of the implant, with a stronger self-tapping feature, may provide better initial stability, even in the presence of a bone defect in the buccal area.

Generation of two induced pluripotent stem cell (iPSC) lines from p.F508del Cystic Fibrosis patients.

Cystic Fibrosis (CF) is a monogenic, lethal disease caused by mutations in the cystic fibrosis transmembrane conductance (CFTR) gene. Here we report the production of CF-iPS cell lines from two different p.F508del homozygous female patients (Table 1). Two different primary cell types, skin fibroblasts and keratinocytes, were transfected with retroviral cocktails containing four: c-MYC, KLF4, OCT4 and SOX2 (MKOS) or three: KLF4, OCT4 and SOX2 (KOS) reprogramming factors. Two fibroblast-derived MKOS lines are described in the main text. The lines carry the p.F508del mutation, have a normal karyotype, express pluripotency markers and are able to differentiate into the three germ layers.

Effects of Resveratrol and Other Polyphenols on the Most Common Brain Age-Related Diseases.

BACKGROUND: With global increase in elderly population, modern societies must find strategies to reduce the consequences of aging process; thereby decreasing the incidence of age-related neurodegenerative diseases. Oxidative stress and recently inflammation, have been pointed out as the leading causes of brain aging. Thereby, the consumption or administration of antioxidant and anti-inflammatory molecules, such as polyphenols, is a beneficial strategy recommended for preventing brain aging and several brain age-related diseases. METHODS AND RESULTS: Several studies suggest that long term consumption of dietary polyphenols offers protection against development of neurodegenerative diseases. These beneficial effects are in part due to their antioxidant and anti-inflammatory properties, together with their positive role in the modulation of processes involved in the physiopathology of several neurodegenerative diseases (e.g., epigenetic factors, amyloid deposition, cholinesterase inhibition, autophagy, and neurotrophic factors, among others). Altogether, these molecules open the door to the research of new neuroprotective strategies. This review summarizes the latest discoveries in how polyphenols can exert positive effects on brain health in aging, emphasizing those effects on the diseases that most commonly affect the brain during aging: Parkinson's Disease (PD), Alzheimer's disease (AD), dementia and depression. Moreover, within are addressed the epigenetic effects of polyphenols as possible mediators in their positive effects on brain health, and the future challenges of research in this topic Conclusion: In brief, this review presents a report of state-of the art knowledge regarding the positive influences of polyphenols on the most common brain age-related diseases as well as in healthy brain aging.

Revisión de la elongación de la apófisis estiloides. Posible etiología genética. A propósito de tres casos clínicos / Examination of the elongation of the styloid apophysis. Possible genetic etiology. Report of three clinical cases

La elongación de la apófisis estiloides afecta hasta a un 28% de la población, pero no siempre con sintomatología asociada. La clasificación expuesta en este artículo aleja a esta patología del concepto clásico de Síndrome de Eagle como único término, se valorará el síndrome estiloideo, síndrome estilo-carotideo, síndrome pseudoestiloideo. Su etiología ha sido pobremente estudiada, desde su relación amigdalectomía-síndrome de Eagle, se expondrán otras posibilidades como la causa genética, aportando tres casos clínicos en una misma familia sin cirugía previa o traumatismos asociados (AU)

The elongation of the styloid process is a common disease, affecting up to 28% of the population, not always with associated symptoms. In this article the different classifications of this condition are exposed, instead of Eagle syndrome as a single term, will be discuss the styloid syndrome, carotid-Styloid, pseudo-styloid syndrome and the Eagle syndrome. The etiology has been poorly studied, since their relationship between tonsillectomy and eagle syndrome. however the possibility of a genetic cause will be discussed by three cases with this disorder in the same family, without any surgery nor traumatism associated (AU)

Sodium colistimethate loaded lipid nanocarriers for the treatment of Pseudomonas aeruginosa infections associated with cystic fibrosis.

Lung impairment is the most life-threatening factor for cystic fibrosis patients. Indeed, Pseudomonas aeruginosa is the main pathogen in the pulmonary infection of these patients. In this work, we developed sodium colistimethate loaded lipid nanoparticles, namely, solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), as a strategy to enhance the antimicrobial therapy against P. aeruginosa in cystic fibrosis patients. The nanoparticles obtained displayed a 200-400 nm size, high drug entrapment (79-94%) and a sustained drug release profile. Moreover, both SLN and NLC presented antimicrobial activity against clinically isolated P. aeruginosa. The integrity of the nanoparticles was not affected by nebulization through a mesh vibrating nebulizer. Moreover, lipid nanoparticles appeared to be less toxic than free sodium colistimethate in cell culture. Finally, an in vivo distribution experiment showed that nanoparticles spread homogenously through the lung and there was no migration of lipid nanoparticles to other organs, such as liver, spleen or kidneys.

Generation of replication-proficient influenza virus NS1 point mutants with interferon-hyperinducer phenotype.

The NS1 protein of influenza A viruses is the dedicated viral interferon (IFN)-antagonist. Viruses lacking NS1 protein expression cannot multiply in normal cells but are viable in cells deficient in their ability to produce or respond to IFN. Here we report an unbiased mutagenesis approach to identify positions in the influenza A NS1 protein that modulate the IFN response upon infection. A random library of virus ribonucleoproteins containing circa 40 000 point mutants in NS1 were transferred to infectious virus and amplified in MDCK cells unable to respond to interferon. Viruses that activated the interferon (IFN) response were subsequently selected by their ability to induce expression of green-fluorescent protein (GFP) following infection of A549 cells bearing an IFN promoter-dependent GFP gene. Using this approach we isolated individual mutant viruses that replicate to high titers in IFN-compromised cells but, compared to wild type viruses, induced higher levels of IFN in IFN-competent cells and had a reduced capacity to counteract exogenous IFN. Most of these viruses contained not previously reported NS1 mutations within either the RNA-binding domain, the effector domain or the linker region between them. These results indicate that subtle alterations in NS1 can reduce its effectiveness as an IFN antagonist without affecting the intrinsic capacity of the virus to multiply. The general approach reported here may facilitate the generation of replication-proficient, IFN-inducing virus mutants, that potentially could be developed as attenuated vaccines against a variety of viruses.

An unbiased genetic screen reveals the polygenic nature of the influenza virus anti-interferon response.

UNLABELLED: Influenza A viruses counteract the cellular innate immune response at several steps, including blocking RIG I-dependent activation of interferon (IFN) transcription, interferon (IFN)-dependent upregulation of IFN-stimulated genes (ISGs), and the activity of various ISG products; the multifunctional NS1 protein is responsible for most of these activities. To determine the importance of other viral genes in the interplay between the virus and the host IFN response, we characterized populations and selected mutants of wild-type viruses selected by passage through non-IFN-responsive cells. We reasoned that, by allowing replication to occur in the absence of the selection pressure exerted by IFN, the virus could mutate at positions that would normally be restricted and could thus find new optimal sequence solutions. Deep sequencing of selected virus populations and individual virus mutants indicated that nonsynonymous mutations occurred at many phylogenetically conserved positions in nearly all virus genes. Most individual mutants selected for further characterization induced IFN and ISGs and were unable to counteract the effects of exogenous IFN, yet only one contained a mutation in NS1. The relevance of these mutations for the virus phenotype was verified by reverse genetics. Of note, several virus mutants expressing intact NS1 proteins exhibited alterations in the M1/M2 proteins and accumulated large amounts of deleted genomic RNAs but nonetheless replicated to high titers. This suggests that the overproduction of IFN inducers by these viruses can override NS1-mediated IFN modulation. Altogether, the results suggest that influenza viruses replicating in IFN-competent cells have tuned their complete genomes to evade the cellular innate immune system and that serial replication in non-IFN-responsive cells allows the virus to relax from these constraints and find a new genome consensus within its sequence space. IMPORTANCE: In natural virus infections, the production of interferons leads to an antiviral state in cells that effectively limits virus replication. The interferon response places considerable selection pressure on viruses, and they have evolved a variety of ways to evade it. Although the influenza virus NS1 protein is a powerful interferon antagonist, the contributions of other viral genes to interferon evasion have not been well characterized. Here, we examined the effects of alleviating the selection pressure exerted by interferon by serially passaging influenza viruses in cells unable to respond to interferon. Viruses that grew to high titers had mutations at many normally conserved positions in nearly all genes and were not restricted to the NS1 gene. Our results demonstrate that influenza viruses have fine-tuned their entire genomes to evade the interferon response, and by removing interferon-mediated constraints, viruses can mutate at genome positions normally restricted by the interferon response.

Complementary roles of tumor necrosis factor alpha and interferon gamma in inducible microglial nitric oxide generation.

Proinflammatory cytokines and pathogen components activate microglia to release several substances such as nitric oxide (NO) produced after the induction of type II nitric oxide synthase (iNOS). The present study was designed to elucidate the interaction between the proinflammatory cytokines interferon gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) on iNOS expression and NO production in microglial cells. In primary mouse microglial cells exposure to IFN-gamma (5 and 10 ng/ml; 48 h) or TNF-alpha (20 ng/ml; 48 h) alone were unable to induce iNOS expression; however, when cells were exposed to both cytokines together, the expression of this enzyme and the NO production in culture media were found significantly increased. In the BV-2 microglial cell line, IFN-gamma and TNF-alpha were shown to cooperate in nuclear factor kappa B (NF-kappa B) activation, an essential transcription factor for iNOS gene transcription. Importantly, IFN-gamma induced NF-kappa B binding to DNA was totally dependent on the endogenous TNF-alpha released via MEK/ERK signalling pathway. Thus, exposure of BV-2 cells to IFN-gamma in the presence of the selective MEK inhibitor U0126 or a neutralizing anti-TNF-alpha antibody significantly reduced IFN-gamma dependent NF-kappa B activation and iNOs expression. In addition, by activating the Jak/STAT pathway IFN-gamma potentiated TNF-alpha induced NF-kappa B binding to DNA and activated additional transcription factors (i.e. IRF-1) known to be essential for iNOs gene expression. The present findings demonstrate that the proinflammatory cytokines IFN-gamma and TNF-alpha have complementary roles on iNOS expression in microglial cells and this might be relevant to understand the molecular mechanisms of microglial activation associated with the pathogenesis of several neuroinflammatory disorders in which increased levels of IFN-gamma and TNF-alpha have been reported.

Vascular endothelial growth factor protects spinal cord motoneurons against glutamate-induced excitotoxicity via phosphatidylinositol 3-kinase.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective death of motoneurons. Recently, vascular endothelial growth factor (VEGF) has been identified as a neurotrophic factor and has been implicated in the mechanisms of pathogenesis of ALS and other neurological diseases. The potential neuroprotective effects of VEGF in a rat spinal cord organotypic culture were studied in a model of chronic glutamate excitotoxicity in which glutamate transporters are inhibited by threohydroxyaspartate (THA). Particularly, we focused on the effects of VEGF in the survival and vulnerability to excitotoxicity of spinal cord motoneurons. VEGF receptor-2 was present on spinal cord neurons, including motoneurons. Chronic (3 weeks) treatment with THA induced a significant loss of motoneurons that was inhibited by co-exposure to VEGF (50 ng/mL). VEGF activated the phosphatidylinositol 3-kinase/Akt (PI3-K/Akt) signal transduction pathway in the spinal cord cultures, and the effect on motoneuron survival was fully reversed by the specific PI3-K inhibitor, LY294002. VEGF also prevented the down-regulation of Bcl-2 and survivin, two proteins implicated in anti-apoptotic and/or anti-excitotoxic effects, after THA exposure. Together, these findings indicate that VEGF has neuroprotective effects in rat spinal cord against chronic glutamate excitotoxicity by activating the PI3-K/Akt signal transduction pathway and also reinforce the hypothesis of the potential therapeutic effects of VEGF in the prevention of motoneuron degeneration in human ALS.

Stimulation of mitogen-activated protein kinase kinases (MEK1/2) by mu-, delta- and kappa-opioid receptor agonists in the rat brain: regulation by chronic morphine and opioid withdrawal.

Opioid addiction modulates the extracellular signal-regulated kinase (ERK) leading to synaptic plasticity in the brain. ERK1/2 are stimulated by mitogen-activated protein kinase kinases (MEK1/2), but little is known about the regulation of MEK activity by opioid drugs. This study was designed to assess the acute effects of selective mu-, delta-, and kappa-opioid receptor agonists, as well as those induced by chronic morphine and opioid withdrawal, on the content of phosphorylated MEK1/2 in the rat brain. Sufentanil (1-30 microg/kg, 30-120 min) induced dose- and time-dependent increases in MEK1/2 phosphorylation in the cerebral cortex and corpus striatum (30-177%) through a naloxone-sensitive mechanism. Morphine (100 mg/kg, 2 h) also augmented MEK1/2 phosphorylation in the both brain regions (50-70%). Similarly, the selective delta-opioid receptor agonist SNC-80 (10 mg/kg, 30 min) increased MEK1/2 activity in the cortex (60%) that was antagonized by naltrindole. In contrast, the selective kappa-opioid receptor agonist (-)-U50488H (10 mg/kg, 30-120 min) did not modify significantly MEK1/2 phosphorylation in the cortex. Chronic morphine (10-100 mg/kg, 5 days) was not associated with alterations in the content of phosphorylated MEK1/2 in the brain (induction of tachyphylaxis to the acute effects). In morphine-dependent rats, however, naloxone (2 mg/kg)-precipitated withdrawal (2-6 h) induced robust increases in MEK1/2 phosphorylation in cortex (27-49%) and striatum (83-123%). Spontaneous opioid withdrawal (24 h) in morphine-dependent rats did not alter MEK1/2 activity in the brain. The findings may be relevant in the context of the pivotal role played by the MEK/ERK pathway in various long-lasting forms of synaptic plasticity associated with opioid addiction.

High-affinity binding of beta-carbolines to imidazoline I2B receptors and MAO-A in rat tissues: norharman blocks the effect of morphine withdrawal on DOPA/noradrenaline synthesis in the brain.

This study was designed to determine the affinity and binding profile of beta-carbolines for imidazoline I2 receptors and catalytic sites of monoamine oxidase (MAO)-A/B in rat brain and liver. The aim was also directed to assess the in vivo effects of norharman (beta-carboline) and LSL 60101 (I2 ligand) on brain 3,4-dihydroxyphenylalanine (DOPA) synthesis in morphine-dependent rats. Competition experiments against [3H]2-BFI revealed that beta-carbolines recognize the high- and low-affinity components of the brain imidazoline I2 receptor with the rank order of potency (K(iH) in nM): noreleagnine (12)>norharman (20)>harmalol (82)>harmaline (177)>>harmine (630)>harman (700)>>FG-7142 (>100,000). In liver, this rank was different: harmine (51)>harmaline (103)=noreleagnine (103)>>harmalol (1290)>harman (2000)>>norharman (12,382)>>FG-7142 (>100,000). In brain and liver, competition curves for beta-carbolines against [3H]Ro41-1049 (MAO-A) and [3H]Ro19-6327 (MAO-B) were monophasic and resulted in different drug potencies for the two MAO isozymes (higher affinities for MAO-A) and in similar pharmacological profiles in both tissues. In morphine-dependent rats, naloxone (2 mg/kg, 2 h)-precipitated withdrawal increased the synthesis of DOPA in the cerebral cortex and hippocampus (50%). Pretreatment with norharman (20 mg/kg) or LSL 60101 (20 mg/kg) (30 min before naloxone) fully prevented the stimulatory effect of opiate withdrawal on DOPA synthesis. Norharman and LSL 60101 also attenuated the severity of the withdrawal syndrome. The results indicate that beta-carbolines bind with high affinity to imidazoline I2B receptors, and similarly to I2 ligands (LSL 60101) can block the behavioural and biochemical effects of opiate withdrawal.