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1.
Article in English | MEDLINE | ID: mdl-38301034

ABSTRACT

Importance: The prompt effective treatment of acute agitation among patients with schizophrenia or bipolar disorder can alleviate distressing symptoms for the patient and decrease the risk of escalation to aggression and the potential for serious harm to the patient, health care providers, and others.Observations: A commonly used approach for the management of acute agitation has been the intramuscular administration of antipsychotic medications and/or benzodiazepines. However, US Food and Drug Administration-approved treatments with alternative routes of delivery now include inhaled loxapine powder and, more recently, dexmedetomidine sublingual film. Two formulations of intranasal olanzapine for acute agitation are in development.Conclusions and Relevance: Intranasal formulations offer the potential for favorable pharmacokinetics and onset of action combined with ease of delivery obviating the need for injections and are thus consistent with patient-centered factors such as preference and self-administration. In this review, alternative methods of medication delivery are discussed, with an emphasis on the potential for intranasal administration to treat acute agitation in adult patients with schizophrenia or bipolar disorder.Prim Care Companion CNS Disord 2024;26(1):23nr03596. Author affiliations are listed at the end of this article.


Subject(s)
Antipsychotic Agents , Bipolar Disorder , Loxapine , Schizophrenia , Adult , Humans , Schizophrenia/complications , Schizophrenia/drug therapy , Antipsychotic Agents/therapeutic use , Bipolar Disorder/complications , Bipolar Disorder/drug therapy , Psychomotor Agitation/drug therapy , Psychomotor Agitation/etiology , Loxapine/adverse effects
2.
Neurol Genet ; 10(1): e200121, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38179414

ABSTRACT

Cerebral cavernous malformations (CCMs) are vascular lesions characterized by a porous endothelium. The lack of a sufficient endothelial barrier can result in microbleeds and frank intracerebral hemorrhage. A primary mechanism for lesion development is a sequence variant in at least 1 of the 3 CCM genes (CCM1, CCM2, and CCM3), which influence various signaling pathways that lead to the CCM phenotype. A common downstream process associated with CCM gene loss of function involves overactivation of RhoA and its effector Rho-associated kinase (ROCK). In this study, we review RhoA/ROCK-related mechanisms involved in CCM pathophysiology as potential therapeutic targets. Literature searches were conducted in PubMed using combinations of search terms related to RhoA/ROCK and CCMs. In endothelial cells, CCM1, CCM2, and CCM3 proteins normally associate to form the CCM protein complex, which regulates the functions of a wide variety of protein targets (e.g., MAP3K3, SMURF1, SOK-1, and ICAP-1) that directly or indirectly increase RhoA/ROCK activity. Loss of CCM complex function and increased RhoA/ROCK activity can lead to the formation of stress fibers that contribute to endothelial junction instability. Other RhoA/ROCK-mediated pathophysiologic outcomes include a shift to a senescence-associated secretory phenotype (primarily mediated by ROCK2), which is characterized by endothelial cell migration, cell cycle arrest, extracellular matrix degradation, leukocyte chemotaxis, and inflammation. ROCK represents a potential therapeutic target, and direct (fasudil, NRL-1049) and indirect (statins) ROCK inhibitors have demonstrated various levels of efficacy in reducing lesion burden in preclinical models of CCM. Current (atorvastatin) and planned (NRL-1049) clinical studies will determine the efficacy of ROCK inhibitors for CCM in humans, for which no US Food and Drug Administration-approved or EU-approved pharmacologic treatment exists.

3.
Front Surg ; 9: 866041, 2022.
Article in English | MEDLINE | ID: mdl-36227017

ABSTRACT

Background: The studies which address the impact of costs of robotic vs. laparoscopic approach on quality of life (cost-effectiveness studies) are scares in general surgery. Methods: The Spanish national study on cost-effectiveness differences among robotic and laparoscopic surgery (ROBOCOSTES) is designed as a prospective, multicentre, national, observational study. The aim is to determine in which procedures robotic surgery is more cost-effective than laparoscopic surgery. Several surgical operations and patient populations will be evaluated (distal pancreatectomy, gastrectomy, sleeve gastrectomy, inguinal hernioplasty, rectal resection for cancer, Heller cardiomiotomy and Nissen procedure). Discussion: The results of this study will demonstrate which treatment (laparoscopic or robotic) and in which population is more cost-effective. This study will also assess the impact of previous surgical experience on main outcomes.

4.
Cell Death Dis ; 12(6): 616, 2021 06 15.
Article in English | MEDLINE | ID: mdl-34131105

ABSTRACT

RTP801/REDD1 is a stress-regulated protein whose upregulation is necessary and sufficient to trigger neuronal death. Its downregulation in Parkinson's and Huntington's disease models ameliorates the pathological phenotypes. In the context of Alzheimer's disease (AD), the coding gene for RTP801, DDIT4, is responsive to Aß and modulates its cytotoxicity in vitro. Also, RTP801 mRNA levels are increased in AD patients' lymphocytes. However, the involvement of RTP801 in the pathophysiology of AD has not been yet tested. Here, we demonstrate that RTP801 levels are increased in postmortem hippocampal samples from AD patients. Interestingly, RTP801 protein levels correlated with both Braak and Thal stages of the disease and with GFAP expression. RTP801 levels are also upregulated in hippocampal synaptosomal fractions obtained from murine 5xFAD and rTg4510 mice models of the disease. A local RTP801 knockdown in the 5xFAD hippocampal neurons with shRNA-containing AAV particles ameliorates cognitive deficits in 7-month-old animals. Upon RTP801 silencing in the 5xFAD mice, no major changes were detected in hippocampal synaptic markers or spine density. Importantly, we found an unanticipated recovery of several gliosis hallmarks and inflammasome key proteins upon neuronal RTP801 downregulation in the 5xFAD mice. Altogether our results suggest that RTP801 could be a potential future target for theranostic studies since it could be a biomarker of neuroinflammation and neurotoxicity severity of the disease and, at the same time, a promising therapeutic target in the treatment of AD.


Subject(s)
Alzheimer Disease/genetics , Encephalitis/genetics , Memory Disorders/genetics , Transcription Factors/physiology , Alzheimer Disease/complications , Alzheimer Disease/pathology , Animals , Case-Control Studies , Disease Models, Animal , Encephalitis/etiology , Encephalitis/pathology , Female , Humans , Male , Memory Disorders/etiology , Memory Disorders/pathology , Mice , Mice, Transgenic , Neuroimmunomodulation/genetics , Neurotoxicity Syndromes/etiology , Neurotoxicity Syndromes/genetics , Neurotoxicity Syndromes/pathology , Severity of Illness Index
5.
Complement Ther Med ; 52: 102482, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32951732

ABSTRACT

Sickle cell disease (SCD) is a hematologic disorder with complex pathophysiology that includes chronic hemolysis, vaso-occlusion and inflammation. Increased leukocyte-erythrocyte-endothelial interactions, due to upregulated expression of adhesion molecules and activated endothelium, are thought to play a primary role in initiation and progression of SCD vaso-occlusive crisis and end-organ damage. Several new pathophysiology-based therapeutic options for SCD are being developed, chiefly targeting the inflammatory pathways. Omega-3 fatty acids are polyunsaturated fatty acids that are known to have effects on diverse physiological processes. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the principal biologically active omega-3 fatty acids. The therapeutic effects of DHA and EPA on chronic inflammatory disorders and cardiovascular diseases are well recognized. The therapeutic effects of omega-3 fatty acids are attributed to their anti-inflammatory and anti-thrombotic eicosanoids, and the novel class of EPA and DHA derived lipid mediators: resolvins, protectins and maresins. Blood cell membranes of patients with SCD have abnormal fatty acids composition characterized by high ratio of pro-inflammatory arachidonic acid (AA) to anti-inflammatory DHA and EPA (high omega-6/omega-3 ratio). In addition, experimental and clinical studies provide evidence that treatment with DHA does confer improvement in rheological properties of sickle RBC, inflammation and hemolysis. The clinical studies have shown improvements in VOC rate, markers of inflammation, adhesion, and hemolysis. In toto, the results of studies on the therapeutic effects of omega-3 fatty acids in SCD provide good body of evidence that omega-3 fatty acids could be a safe and effective treatment for SCD.


Subject(s)
Anemia, Sickle Cell/drug therapy , Fatty Acids, Omega-3/pharmacology , Fatty Acids, Omega-3/therapeutic use , Humans
6.
Article in English | MEDLINE | ID: mdl-32447175

ABSTRACT

Sickle cell disease (SCD) is one of the most common inherited blood disorder among African Americans affecting 70,000-100,000 individuals in the United States. It is characterized by abnormal hemoglobin (HbS) which develops into severe hemolytic anemia and vaso-occlusive crisis. Therefore, patients with SCD suffer from a chronic state of inflammation, which is responsible for multiple organ damage, ischemic attacks, and premature death. Another major hallmark of SCD patients is the abnormally low levels of omega-3 fatty acids, especially docosahexaenoic acid (DHA) in their red blood cell membranes. Treatment with DHA can reduce red blood cell adhesion and enhance cerebral blood flow, thus, our main goal is to investigate the effect of SC411, which is a novel, highly purified DHA ethyl ester formulation with a proprietary delivery platform in SCD. Utilizing a transgenic mouse model of SCD (HbSS-Townes) and recurrent hypoxic challenges (10%O2, 0.5% CO2 and balance N2 for 3 h) to mimic ischemic-like conditions, our data suggest that SC411 can elevate blood DHA and eicosapentaenoic acid (EPA) levels after 8 weeks of treatment. SC411 can also decrease arachidonic acid (AA) and sickling of red blood cells. In addition, SC411-treated SCD mice showed presented with cerebral blood flow, alleviated neuroinflammation, and revived working memory which ultimately enhanced overall survival. In summary, this study suggests that treatment with SC411 improves cellular and functional outcomes in SCD mice. This finding may provide novel therapeutic opportunities in the treatment against ischemic injury elicited by SCD.


Subject(s)
Anemia, Sickle Cell/drug therapy , Docosahexaenoic Acids/chemistry , Esters/administration & dosage , Anemia, Sickle Cell/genetics , Anemia, Sickle Cell/psychology , Animals , Arachidonic Acid/blood , Cerebrovascular Circulation , Disease Models, Animal , Docosahexaenoic Acids/blood , Esters/chemistry , Esters/pharmacology , Humans , Male , Memory, Short-Term/drug effects , Mice , Mice, Transgenic , Survival Analysis , Treatment Outcome
7.
PLoS One ; 14(9): e0221258, 2019.
Article in English | MEDLINE | ID: mdl-31483835

ABSTRACT

In any sport the selection of players for a team is fundamental for its subsequent performance. Many factors condition the selection process from the characteristics of the sport discipline to financial limitations, including a long list of restrictions associated with the environment of the competitions in which the team takes part. All of this makes the process of selecting a roster of players very complex, as it is affected by multiple variables and in many cases marked by a great deal of subjectivity. The purpose of this article was to objectively select the players for a basketball team using an evolutionary algorithm, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) that uses stochastic search methods based on the imitation of natural biological evolution. The sample was composed of the players from the teams competing in the top Spanish basketball league, the Association of Basketball Clubs (ACB). To assess the quality of the solutions obtained, the results were compared with the teams in the ACB playing in the same competition as the players used in the study. The results make it possible to obtain different solutions for composing teams rendering financial resources profitable and taking into account the restrictions of the competition and of each sport management.


Subject(s)
Algorithms , Athletic Performance , Basketball , Humans
8.
Exp Eye Res ; 187: 107773, 2019 10.
Article in English | MEDLINE | ID: mdl-31445902

ABSTRACT

The retinal degeneration 10 (rd10) mouse is a model of autosomal recessive retinitis pigmentosa (RP), a disease that causes blindness through the progressive loss of photoreceptors. This study shows evidence of sex-related differences in RP onset and progression in rd10 retinas. The disease onset was considerably earlier in the female rd10 mice than in the male rd10 mice, as evidenced by a loss of PDE6ß proteins and rod-dominated electroretinogram (ERG) responses at an early age. Single photopic flash and flicker ERG responses and immunolabeling of opsin molecules were analyzed in both genders to assess the sex differences in the degeneration of cones in the RP retinas. The averaged amplitudes of cone-mediated ERG responses obtained from the females were significantly smaller than the amplitudes of the responses from the age-matched males in the late stages of the RP, suggesting that cones might degenerate faster in the female retinas as the disease progressed. The rapid degeneration of cones caused a more substantial decrease in the ERG responses derived from the On-pathway than the Off-pathway in the females. In addition, the male rd10 mice had heavier body weights than their female counterparts aged between postnatal (P)18 and P50 days. In summary, female rd10 mice were more susceptible to retinal degeneration, suggesting that the female sex might be a risk factor for RP. The results have important implications for future studies exploring potential sex-related differences in RP development and progression in the clinic.


Subject(s)
Retina/physiopathology , Retinitis Pigmentosa/physiopathology , Sex Factors , Animals , Blotting, Western , Body Weight , Cyclic Nucleotide Phosphodiesterases, Type 6/metabolism , Disease Models, Animal , Disease Progression , Electroretinography , Female , Immunohistochemistry , Male , Mice , Mice, Inbred C57BL , Mice, Mutant Strains , Retina/enzymology , Retinal Cone Photoreceptor Cells/enzymology , Retinal Cone Photoreceptor Cells/physiology , Retinal Rod Photoreceptor Cells/enzymology , Retinal Rod Photoreceptor Cells/physiology , Retinitis Pigmentosa/diagnosis , Retinitis Pigmentosa/enzymology
9.
J Drug Deliv ; 2019: 1957360, 2019.
Article in English | MEDLINE | ID: mdl-31360551

ABSTRACT

Despite recent advances, the drug development process continues to face significant challenges to efficiently improve the poor solubility of active pharmaceutical ingredients (API) in aqueous media or to improve the bioavailability of lipid-based formulations. The inherent high intra- and interindividual variability of absorption of oral lipophilic drug leads to inconsistent and unpredictable bioavailability and magnitude of the therapeutic effect. For this reason, the development of lipid-based drugs remains a challenging endeavour with a high risk of failure. Therefore, effective strategies to assure a predictable, consistent, and reproducible bioavailability and therapeutic effect for lipid-based medications are needed. Different solutions to address this problem have been broadly studied, including the approaches of particle size reduction, prodrugs, salt forms, cocrystals, solid amorphous forms, cyclodextrin clathrates, and lipid-based drug delivery systems such as self-emulsifying systems and liposomes. Here, we provide a brief description of the current strategies commonly employed to increase the bioavailability of lipophilic drugs and present Advanced Lipid Technologies® (ALT®), a combination of different surfactants that has been demonstrated to improve the absorption of omega-3 fatty acids under various physiological and pathological states.

10.
Sensors (Basel) ; 18(11)2018 Nov 21.
Article in English | MEDLINE | ID: mdl-30469380

ABSTRACT

The Internet of Things (IoT) is faced with challenges that require green solutions and energy-efficient paradigms. Architectures (such as ARM) have evolved significantly in recent years, with improvements to processor efficiency, essential for always-on devices, as a focal point. However, as far as software is concerned, few approaches analyse the advantages of writing efficient code when programming IoT devices. Therefore, this proposal aims to improve source code optimization to achieve better execution times. In addition, the importance of various techniques for writing efficient code for Raspberry Pi devices is analysed, with the objective of increasing execution speed. A complete set of tests have been developed exclusively for analysing and measuring the improvements achieved when applying each of these techniques. This will raise awareness of the significant impact the recommended techniques can have.

11.
J Clin Lipidol ; 11(2): 394-405, 2017.
Article in English | MEDLINE | ID: mdl-28502496

ABSTRACT

BACKGROUND: The absorption of eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) omega-3-acid ethyl esters (EEs) is influenced by food. There is a need for a formulation of EE that is less impacted by food effect. SC401 is a novel Advanced Lipid Technologies-based formulation of EPA-EE and DHA-EE. In the presence of an aqueous medium, Advanced Lipid Technologies forms stable micelles in situ independent of bile salt secretion. This effect is hypothesized to improve EPA-EE and DHA-EE bioavailability while it helps mitigate the food effect associated with their consumption. OBJECTIVE: The aim of the article was to assess the effect of food on the bioavailability of DHA and EPA after a single oral dose of 1530 mg omega-3 fatty acids EE (SC401) in 24 healthy subjects under fasted and low-fat (9% of total calories from fat) and high-fat (50% of total calories from fat) meal conditions. METHODS: This was a randomized, open-label, single-dose, 3-period, 3-way crossover study. Blood samples for pharmacokinetic analyses were taken at predose and at 0.5, 1, 2, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8, 10, 12 and 24 hours postdose. To assess the safety of the intervention, active monitoring of adverse events, physical examinations, vital signs, clinical laboratory assessments (chemistry, hematology, and urinalysis), and 12-lead electrocardiograms were conducted. RESULTS: SC401 showed high bioavailability of both EPA and DHA in fasted, low-fat meal, and high-fat meal conditions. No differences were found in SC401 DHA AUC0-t (t = 24 hours) among the 3 conditions (91.69% high-fat/fasted, 97.12% low-fat/fasted, and 105.92% low-fat/high-fat; P > .05 in all cases). In contrast, SC401 EPA AUC0-t was affected by food intake (179.06% high-fat/fasted, P < .0001; 150.05% low-fat/fasted, P < .0001) and the amount of fat taken with SC401 (83.80% low-fat/high-fat; P = .0009). SC401 was safe and well tolerated. CONCLUSIONS: A single dose of SC401 resulted in high levels of EPA and DHA total lipids in plasma in fasting and fed conditions. SC401 overcame the food effect for DHA and partially ameliorated it for EPA. SC401 represents a convenient option for treatment of severe hypertriglyceridemia, especially for patients under a restricted intake of dietary fat.


Subject(s)
Docosahexaenoic Acids/chemistry , Docosahexaenoic Acids/pharmacokinetics , Drug Compounding , Eicosapentaenoic Acid/chemistry , Eicosapentaenoic Acid/pharmacokinetics , Esters/chemistry , Food , Adult , Biological Availability , Diet, High-Fat , Docosahexaenoic Acids/adverse effects , Eicosapentaenoic Acid/adverse effects , Fasting , Female , Humans , Male
12.
Clin Ther ; 39(3): 581-591, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28189364

ABSTRACT

PURPOSE: The US Food and Drug Administration has approved several highly purified ω-3 fatty acid prescription drugs for the treatment of severe hypertriglyceridemia. These differ in the amounts and forms of docosahexaenoic acid (DHA) and/or eicosapentaenoic acid (EPA). This study compared the bioavailability of SC401 (1530 mg EPA-ethyl esters [EEs] and DHA-EEs plus Advanced Lipid Technologies⁎ [ALT†], a proprietary lipid-delivery platform to improve absorption), with. Lovaza‡ (3600 mg ω-3, primarily EPA-EEs and DHA-EEs) under low-fat feeding conditions. METHODS: This was a Phase I, randomized, open-label, single-dose, 2-way crossover study in healthy participants housed from day -3 to day 2 in each treatment period. Blood samples for pharmacokinetic measurements were collected before and after dosing, and safety profile and tolerability were assessed. FINDINGS: In unadjusted analyses, SC401 had 5% lower Cmax and approximately the same AUC0-last of EPA + DHA total lipids compared with Lovaza. When adjusted for baseline, SC401 had ~6% higher Cmax and 18% higher AUC0-last for EPA + DHA total lipids, and dose- and baseline-adjusted analyses found that SC401 had ~149% higher Cmax and 178% higher AUC0-last than Lovaza for EPA + DHA total lipids. The Tmax was also substantially longer with Lovaza (~10 hours) than with SC401 (~6 hours). IMPLICATIONS: These results indicate that SC401, an ω-3 acid EE formulation containing ALT† achieved high bioavailability of EPA and DHA, at a lower dose (1530 mg) than Lovaza (3600 mg), under low-fat feeding conditions.


Subject(s)
Docosahexaenoic Acids/administration & dosage , Eicosapentaenoic Acid/administration & dosage , Fatty Acids, Omega-3/administration & dosage , Hypolipidemic Agents/administration & dosage , Adult , Biological Availability , Chemistry, Pharmaceutical , Cross-Over Studies , Docosahexaenoic Acids/pharmacokinetics , Drug Combinations , Eicosapentaenoic Acid/pharmacokinetics , Fatty Acids, Omega-3/therapeutic use , Female , Humans , Hypertriglyceridemia/drug therapy , Hypolipidemic Agents/therapeutic use , Male , Middle Aged , Young Adult
13.
J Nutr Biochem ; 37: 39-46, 2016 11.
Article in English | MEDLINE | ID: mdl-27611101

ABSTRACT

Food-derived peptides, such as ß-casomorphin BCM7, have potential to cross the gastrointestinal tract and blood-brain barrier and are associated with neurological disorders and neurodevelopmental disorders. We previously established a novel mechanism through which BCM7 affects the antioxidant levels in neuronal cells leading to inflammatory consequences. In the current study, we elucidated the effects of casein-derived peptides on neuronal development by using the neurogenesis of neural stem cells (NSCs) as an experimental model. First, the transient changes in intracellular thiol metabolites during NSC differentiation (neurogenesis) were investigated. Next, the neurogenic effects of food-derived opioid peptides were measured, along with changes in intracellular thiol metabolites, redox status and global DNA methylation levels. We observed that the neurogenesis of NSCs was promoted by human BCM7 to a greater extent, followed by A2-derived BCM9 in contrast to bovine BCM7, which induced increased astrocyte formation. The effect was most apparent when human BCM7 was administered for 1day starting on 3days postplating, consistent with immunocytochemistry. Furthermore, neurogenic changes regulated by bovine BCM7 and morphine were associated with an increase in the glutathione/glutathione disulfide ratio and a decrease in the S-adenosylmethionine/S-adenosylhomocysteine ratio, indicative of changes in the redox and the methylation states. Finally, bovine BCM7 and morphine decreased DNA methylation in differentiating NSCs. In conclusion, these results suggest that food-derived opioid peptides and morphine regulated neurogenesis and differentiation of NSCs through changes in the redox state and epigenetic regulation.


Subject(s)
Caseins/metabolism , DNA Methylation , Endorphins/metabolism , Epigenesis, Genetic , Neural Stem Cells/metabolism , Neurogenesis , Opioid Peptides/metabolism , Peptide Fragments/metabolism , Analgesics, Opioid/pharmacology , Animals , Apoptosis/drug effects , Astrocytes/cytology , Astrocytes/drug effects , Astrocytes/immunology , Astrocytes/metabolism , Caseins/adverse effects , Caseins/chemistry , Cattle , Cell Proliferation/drug effects , Cells, Cultured , DNA Methylation/drug effects , Endorphins/adverse effects , Endorphins/chemistry , Epigenesis, Genetic/drug effects , Glutathione/chemistry , Glutathione/metabolism , Humans , Methylation , Morphine/pharmacology , Neural Stem Cells/cytology , Neural Stem Cells/drug effects , Neural Stem Cells/immunology , Neurogenesis/drug effects , Opioid Peptides/adverse effects , Opioid Peptides/chemistry , Oxidation-Reduction , Peptide Fragments/adverse effects , Peptide Fragments/chemistry , Protein Processing, Post-Translational , S-Adenosylhomocysteine/chemistry , S-Adenosylhomocysteine/metabolism , S-Adenosylmethionine/chemistry , S-Adenosylmethionine/metabolism
14.
Nat Biotechnol ; 30(5): 453-9, 2012 Mar 25.
Article in English | MEDLINE | ID: mdl-22446693

ABSTRACT

The ability to specifically upregulate genes in vivo holds great therapeutic promise. Here we show that inhibition or degradation of natural antisense transcripts (NATs) by single-stranded oligonucleotides or siRNAs can transiently and reversibly upregulate locus-specific gene expression. Brain-derived neurotrophic factor (BDNF) is normally repressed by a conserved noncoding antisense RNA transcript, BDNF-AS. Inhibition of this transcript upregulates BDNF mRNA by two- to sevenfold, alters chromatin marks at the BDNF locus, leads to increased protein levels and induces neuronal outgrowth and differentiation both in vitro and in vivo. We also show that inhibition of NATs leads to increases in glial-derived neurotrophic factor (GDNF) and ephrin receptor B2 (EPHB2) mRNA. Our data suggest that pharmacological approaches targeting NATs can confer locus-specific gene upregulation effects.


Subject(s)
Oligonucleotides, Antisense/antagonists & inhibitors , Up-Regulation , Animals , Cell Line , Chromatin/chemistry , Chromatin/metabolism , Exons , Gene Expression Profiling , Genomics , Glial Cell Line-Derived Neurotrophic Factor/biosynthesis , HEK293 Cells , Humans , Mice , Models, Genetic , RNA, Messenger/metabolism , RNA, Small Interfering/metabolism , Receptor, EphB2/biosynthesis , Sequence Analysis, DNA , Transcription, Genetic
15.
Stem Cells ; 29(10): 1628-39, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21837653

ABSTRACT

Neural precursor cells (NPCs) are activated in central nervous system injury. However, despite being multipotential, their progeny differentiates into astrocytes rather than neurons in situ. We have investigated the role of epidermal growth factor receptor (EGFR) in the generation of non-neurogenic conditions. Cultured mouse subventricular zone NPCs exposed to differentiating conditions for 4 days generated approximately 50% astrocytes and 30% neuroblasts. Inhibition of EGFR with 4-(3-chloroanilino)-6,7-dimethoxyquinazoline significantly increased the number of neuroblasts and decreased that of astrocytes. The same effects were observed upon treatment with the metalloprotease inhibitor galardin, N-[(2R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl]-L-tryptophan methylamide (GM 6001), which prevented endogenous transforming growth factor-α (TGF-α) release. These results suggested that metalloprotease-dependent EGFR-ligand shedding maintained EGFR activation and favored gliogenesis over neurogenesis. Using a disintegrin and metalloprotease 17 (ADAM-17) small interference RNAs transfection of NPCs, ADAM-17 was identified as the metalloprotease involved in cell differentiation in these cultures. In vivo experiments revealed a significant upregulation of ADAM-17 mRNA and de novo expression of ADAM-17 protein in areas of cortical injury in adult mice. Local NPCs, identified by nestin staining, expressed high levels of ADAM-17, as well as TGF-α and EGFR, the three molecules necessary to prevent neurogenesis and promote glial differentiation in vitro. Chronic local infusions of GM6001 resulted in a notable increase in the number of neuroblasts around the lesion. These results indicate that, in vivo, the activation of a metalloprotease, most probably ADAM-17, initiates EGFR-ligand shedding and EGFR activation in an autocrine manner, preventing the generation of new neurons from NPCs. Inhibition of ADAM-17, the limiting step in this sequence, may contribute to the generation of neurogenic niches in areas of brain damage.


Subject(s)
ADAM Proteins/metabolism , Neural Stem Cells/cytology , Neurogenesis , Neurons/cytology , ADAM Proteins/antagonists & inhibitors , ADAM Proteins/genetics , ADAM17 Protein , Animals , Astrocytes/cytology , Astrocytes/enzymology , Brain Injuries/enzymology , Brain Injuries/metabolism , Cell Differentiation , Cell Proliferation , Dipeptides/pharmacology , Enzyme Activation , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/metabolism , Female , Immunohistochemistry , Intermediate Filament Proteins/genetics , Intermediate Filament Proteins/metabolism , Male , Mice , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Nestin , Neural Stem Cells/enzymology , Quinazolines/pharmacology , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Transfection , Transforming Growth Factor alpha/genetics , Transforming Growth Factor alpha/metabolism , Tyrphostins/pharmacology
18.
Int J Alzheimers Dis ; 2011: 929042, 2011.
Article in English | MEDLINE | ID: mdl-21785702

ABSTRACT

Background. Alzheimer's disease (AD) is a devastating neurological disorder and the main cause of dementia in the elderly population worldwide. Adult neurogenesis appears to be upregulated very early in AD pathogenesis in response to some specific aggregates of beta-amyloid (Aß) peptides, exhausting the neuronal stem cell pools in the brain. Previously, we characterized a conserved nonprotein-coding antisense transcript for ß-secretase-1 (BACE1), a critical enzyme in AD pathophysiology. We showed that the BACE1-antisense transcript (BACE1-AS) is markedly upregulated in brain samples from AD patients and promotes the stability of the (sense) BACE1 transcript. In the current paper, we examine the relationship between BACE1, BACE1-AS, adult neurogenesis markers, and amyloid plaque formation in amyloid precursor protein (APP) transgenic mice (Tg-19959) of various ages. Results. Consistent with previous publications in other APP overexpressing mouse models, we found adult neurogenesis markers to be noticeably upregulated in Tg-19959 mice very early in the development of the disease. Knockdown of either one of BACE1 or BACE1-AS transcripts by continuous infusion of locked nucleic acid- (LNA-) modified siRNAs into the third ventricle over the period of two weeks caused concordant downregulation of both transcripts in Tg-19959 mice. Downregulation of BACE1 mRNA was followed by reduction of BACE1 protein and insoluble Aß. Modulation of BACE1 and BACE1-AS transcripts also altered oligomeric Aß aggregation pattern, which was in turn associated with an increase in neurogenesis markers at the RNA and protein level. Conclusion. We found alterations in the RNA and protein concentrations of several adult neurogenesis markers, as well as non-protein-coding BACE1-AS transcripts, in parallel with the course of ß-amyloid synthesis and aggregation in the brain of Tg15999 mice. In addition, by knocking down BACE1 or BACE1-AS (thereby reducing Aß production and plaque deposition), we were able to modulate expression of these neurogenesis markers. Our findings suggest a distortion of adult neurogenesis that is associated with Aß production very early in amyloid pathogenesis. We believe that these alterations, at the molecular level, could prove useful as novel therapeutic targets and/or as early biomarkers of AD.

19.
J Neurosci ; 31(9): 3186-96, 2011 Mar 02.
Article in English | MEDLINE | ID: mdl-21368030

ABSTRACT

The generation, differentiation, and migration of newborn neurons are critical features of normal brain development that are subject to both extracellular and intracellular regulation. However, the means of such control are only partially understood. Here, we show that expression of RTP801/REDD1, an inhibitor of mTOR (mammalian target of rapamycin) activation, is regulated during neuronal differentiation and that RTP801 functions to influence the timing of both neurogenesis and neuron migration. RTP801 levels are high in embryonic cortical neuroprogenitors, diminished in newborn neurons, and low in mature neurons. Knockdown of RTP801 in vitro and in vivo accelerates cell cycle exit by neuroprogenitors and their differentiation into neurons. It also disrupts migration of rat newborn neurons to the cortical plate and results in the ectopic localization of mature neurons. On the other hand, RTP801 overexpression delays neuronal differentiation. These findings suggest that endogenous RTP801 plays an essential role in temporal control of cortical development and in cortical patterning.


Subject(s)
Cell Movement/physiology , Cerebral Cortex/physiology , Neurogenesis/physiology , Neurons/cytology , Neurons/physiology , Repressor Proteins/physiology , Animals , Body Patterning/genetics , Body Patterning/physiology , Cell Differentiation/genetics , Cell Differentiation/physiology , Cell Movement/genetics , Cells, Cultured , Cerebral Cortex/cytology , Gene Knockdown Techniques , Humans , Mice , Mice, Inbred C57BL , Neurogenesis/genetics , PC12 Cells , Rats , Repressor Proteins/antagonists & inhibitors , Repressor Proteins/genetics , Stem Cells/cytology , Stem Cells/physiology , Time Factors , Transcription Factors
20.
J Alzheimers Dis ; 20(2): 395-408, 2010.
Article in English | MEDLINE | ID: mdl-20164555

ABSTRACT

Alzheimer's disease (AD) is a devastating age-related neurodegenerative disorder characterized by progressive impairment of cognition and short-term memory loss. The deposition of amyloid-beta (Abeta) 1-42 into senile plaques is an established feature of AD neuropathology. Controversy still exists about the amyloid pathway as the initiating mechanism or a mere consequence of the events leading to AD. Nevertheless, Abeta toxicity has been probed in vitro and in vivo and increased production or decreased clearance of Abeta peptides are reported to play a major role in the development of AD. Treatment of neural stem cells with Abeta in vitro induces neuronal differentiation. Increased neurogenesis has been also described in AD patients as well as in amyloid-beta protein precursor (AbetaPP) transgenic mice. Adult neurogenesis is greatly enhanced in young AbetaPP transgenic mice, before other AD-liked pathologies, and reduced in older animals. This increased neurogenesis at young ages might be the first pathology related to AD, which is detectable long before other harmful manifestation of the disease. Therefore, understanding the mechanisms of Abeta-induced neurogenesis will reveal insights into the pathogenesis of AD and may prove useful as an early AD biomarker.


Subject(s)
Alzheimer Disease/diagnosis , Alzheimer Disease/physiopathology , Amyloid beta-Peptides , Amyloid beta-Protein Precursor/drug effects , Neurogenesis/physiology , Peptide Fragments , Alzheimer Disease/metabolism , Alzheimer Disease/therapy , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/metabolism , Animals , Brain/metabolism , Brain/pathology , Humans , Neurons/physiology , Peptide Fragments/metabolism , Stem Cells/physiology
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