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Τετάρτη 11 Σεπτεμβρίου 2019

ELMO Domain Containing 1 ( ELMOD1 ) Gene Mutation Is Associated with Mental Retardation and Autism Spectrum Disorder

Abstract

ELMO domain containing 1 (ELMOD1) encodes a protein with GTPase-activating functions. Previous studies have confirmed its overexpression in brain tissues. Although no previous study has reported mutations in this gene in human subjects, spontaneous inactivating mutations in the mouse homolog of this gene have been associated with deafness and balance problems. In the current study, we have performed whole exome sequencing (WES) in a patient with intellectual disability. We found a novel mutation in ELMOD1 gene (c.571delG, p.D191MfsTer25) in the proband and two other affected cases in the family. Segregation analysis showed that parents carried the mutation in the heterozygote state. Consequently, the current study reports the first case of mutation in ELMOD1 in human subjects and demonstrates the significant difference in the phenotypes associated with ELMOD1 mutations in humans and mice.

Klotho Is Neuroprotective in the Superoxide Dismutase (SOD1 G93A ) Mouse Model of ALS

Abstract

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by the loss of motor neurons in the brain and spinal cord. ALS neuropathology is associated with increased oxidative stress, excitotoxicity, and inflammation. We and others reported that the anti-aging and cognition-enhancing protein Klotho is a neuroprotective, antioxidative, anti-inflammatory, and promyelinating protein. In mice, its absence leads to an extremely shortened life span and to multiple phenotypes resembling human aging, including motor and hippocampal neurodegeneration and cognitive impairment. In contrast, its overexpression extends life span, enhances cognition, and confers resistance against oxidative stress; it also reduces premature mortality and cognitive and behavioral abnormalities in an animal model for Alzheimer’s disease (AD). These pleiotropic beneficial properties of Klotho suggest that Klotho could be a potent therapeutic target for preventing neurodegeneration in ALS. Klotho overexpression in the SOD1 mouse model of ALS resulted in delayed onset and progression of the disease and extended survival that was more prominent in females than in males. Klotho reduced the expression of neuroinflammatory markers and prevented neuronal loss with the more profound effect in the spinal cord than in the motor cortex. The effect of Klotho was accompanied by reduced expression of proinflammatory cytokines and enhanced the expression of antioxidative and promyelinating factors in the motor cortex and spinal cord of Klotho × SOD1 compared to SOD1 mice. Our study provides evidence that increased levels of Klotho alleviate ALS-associated pathology in the SOD1 mouse model and may serve as a basis for developing Klotho-based therapeutic strategies for ALS.

Does SCFD1 rs10139154 Polymorphism Decrease Alzheimer’s Disease Risk?

Abstract

Α number of genetic variants have been associated with Alzheimer’s disease (AD) susceptibility. Sec1 family domain-containing protein 1 (SCFD1) gene polymorphism rs10139154 has recently been implicated in the risk of developing amyotrophic lateral sclerosis (ALS). Similarities in the pathogenetic cascade of both diseases have also been described. The present study was designed to evaluate the possible contribution of SCFD1 rs10139154 to AD. A total of 327 patients with AD and an equal number of healthy controls were included in the study and genotyped for rs10139154. With logistic regression analyses, rs10139154 was examined for the association with the risk of developing AD. In the recessive mode, SCFD1 rs10139154 was associated with a decreased risk of developing AD (odds ratio (OR) (95% confidence interval (CI)) = 0.63 (0.40–0.97), p = 0.036). The current study provides preliminary evidence of the involvement of SCFD1 rs10139154 in the risk of developing AD.

Improvement of Language in Children with Autism with Combined Donepezil and Choline Treatment

Abstract

The safety and efficacy of a novel combination treatment of AChE inhibitors and choline supplement was initiated and evaluated in children and adolescents with autism spectrum disorder (ASD). Safety and efficacy were evaluated on 60 children and adolescents with ASD during a 9-month randomized, double-blind, placebo-controlled trial comprising 12 weeks of treatment preceded by baseline evaluation, and followed by 6 months of washout, with subsequent follow-up evaluations. The primary exploratory measure was language, and secondary measures included core autism symptoms, sleep and behavior. Significant improvement was found in receptive language skills 6 months after the end of treatment as compared to placebo. The percentage of gastrointestinal disturbance reported as a side effect during treatment was higher in the treatment group as compared to placebo. The treatment effect was enhanced in the younger subgroup (younger than 10 years), occurred already at the end of the treatment phase, and was sustained at 6 months post treatment. No significant side effects were found in the younger subgroup. In the adolescent subgroup, no significant improvement was found, and irritability was reported statistically more often in the adolescent subgroup as compared to placebo. Combined treatment of donepezil hydrochloride with choline supplement demonstrates a sustainable effect on receptive language skills in children with ASD for 6 months after treatment, with a more significant effect in those under the age of 10 years.

2-(4-Methoxyphenyl)Ethyl-2-Acetamido-2-Deoxy-β- d -Pyranoside Exerts a Neuroprotective Effect through Regulation of Energy Homeostasis and O-GlcNAcylation

Abstract

Dysfunction of energy metabolism exerts a central role in triggering neuron death following cerebral ischemia. Neuronal energy metabolism is highly dependent on glucose. O-GlcNAcylation, a post-translational modification, is a novel pro-survival pathway that modulates glucose homeostasis in ischemic stroke. Here, we explored whether activation O-GlcNAcylation and maintaining energy homeostasis mediated the neuroprotective effect of 2-(4-methoxyphenyl)ethyl-2-acetamido-2-deoxy-β-d-pyranoside, a synthetic salidroside analog (named SalA-4 g) which was previously developed in our laboratory. For in vivo analyses, SalA-4 g improved the outcome after transient middle cerebral artery occlusion (MCAO). 18F-FDG PET/MRI indicated that SalA-4 g accelerated the recovery of energy metabolism in the ipsilateral hippocampus in MCAO rats. In vitro analyses showed that glucose uptake was markedly increased, and O-GlcNAcylation was also activated by SalA-4 g in hippocampal neurons under both normal and oxygen glucose deprivation (OGD) conditions. Moreover, SalA-4 g exerted obvious neuroprotective effects in hippocampal neurons against moderate OGD injury. Our study indicates that boosting a pro-survival pathway—GlcNAcylation—and regulating energy homeostasis are important biochemical mechanisms responsible for SalA-4 g neuroprotection.

Interleukine-17 Administration Modulates Adult Hippocampal Neurogenesis and Improves Spatial Learning in Mice

Abstract

Adult hippocampal neurogenesis plays an important role in health and disease. Regulating neurogenesis may be a key mechanism in the pathophysiology and treatment of several neurobehavioral disorders such as schizophrenia, depression, autism spectrum disorders and Alzheimer’s disease. Cytokines are known to affect adult neurogenesis, but conflicting studies have been reported with regard to their actual role. Interleukine-17 (IL-17), a potent pro-inflammatory cytokine, has been shown to inhibit proliferation of neuroprogenitors and thus reduce hippocampal neurogenesis, while other studies suggested it can promote neurite outgrowth. In the present study we sought to explore the possible effect of a single dose administration of IL-17 on neurogenesis related behavior, i.e. spatial learning. Surprisingly, ICR mice injected with IL-17 (8 μg) had a significant slight improvement in spatial learning in the Morris water maze paradigm, without any changes in general locomotion compared with control mice. Indeed, the expression of neurogenesis related genes was down regulated following IL-17 treatment. However, we detected an upregulation in the expression of FGF-13, a gene promoting microtubule polymerization and neurite outgrowth, thus supporting neuronal maturation. We thus suggest that IL-17 has a complex role in regulating adult neurogenesis: inhibiting neuroprogenitors proliferation on one hand, while promoting maturation of already formed neuroblasts on the other hand. Our findings suggest that these roles can potentially affect neurogenesis related behavior. Its actual role in health and disease is yet to be determined.

TGF-β Secretion by M2 Macrophages Induces Glial Scar Formation by Activating Astrocytes In Vitro

Abstract

Transforming growth factor-β (TGF-β) is a key factor that promotes fibrosis or scar formation, which could become an obstacle in the repair of impaired axons in the central nervous system (CNS) of the human body resulting from diseases or injuries. Considering that major pathological reactions occur during this process, we focused on TGF-secreting M2 macrophages to identify the interactions between M2 macrophages and astrocytes (AS) and verify the specific mechanism of fibrosis or glial scar formation. In the present study, we used the Transwell coculturing technique and found an increase in glial fibrillary acidic protein (GFAP), neurocan, IL-13, and TGF-β expression after incubation for 48 h; the expression of these proteins decreased when additional inhibitors of the TGF-β receptor were added. We concluded that fibrosis or glial scar formation would be enhanced by the secretion of neurocan from AS, resulting from the release of TGF-β from M2 macrophages. We also used M2 macrophage–conditioned medium to further confirm this finding in a subsequent experiment. We hope that the findings in this research could provide a foundation for locating new targets for treating CNS diseases or injuries.

Friends Turn Foe—Astrocytes Contribute to Neuronal Damage in NeuroAIDS

Abstract

Astrocytes play a wide variety of roles in the central nervous system (CNS). Various facets of astrocyte-neuron interplay, investigated for the past few decades, have placed these most abundant and important glial cell types to be of supreme importance for the maintenance of the healthy CNS. Interestingly, glial dysfunctions have proven to be the major contributor to neuronal loss in several CNS disorders and pathologies. Specifically, in the field of neuroAIDS, glial dysfunction–mediated neuronal stress is a major factor contributing to the HIV-1 neuropathogenesis. As there is increasing evidence that astrocytes harbor HIV-1 and serve as “safe haven” for the dormant virus in the brain, the indirect pathway of neuronal damage has taken over the direct neuronal damage in its contribution to HIV-1 neuropathogenesis. In this review, we provide a brief insight into the astrocyte functions and dysfunctions in different CNS conditions with an elaborated insight into neuroAIDS. Detailed understanding of the role of astrocytes in neuroAIDS will help in the better therapeutic management of the neurological problems associated with HIV-1 patients.

Inhibition of Mast Cell Degranulation Relieves Visceral Hypersensitivity Induced by Pancreatic Carcinoma in Mice

Abstract

Cancer pain induced by pancreatic carcinoma is one of the most common symptoms and is difficult to endure, especially in the advanced stage. Evidence suggests that mast cells are recruited and degranulate in enteric disease-related visceral hypersensitivity. However, whether mast cells promote the visceral pain induced by pancreatic carcinoma remains unclear. Here, using toluidine blue staining and western blotting, we observed that mast cells were dramatically recruited to tissues surrounding pancreatic carcinoma, but not inside the carcinoma in patients with severe visceral pain. The levels of mast cell degranulation products, including tryptase, histamine, and nerve growth factor, were significantly increased in pericarcinoma tissues relative to their levels in normal controls, as evidenced by enzyme-linked immunosorbent assay. We determined that systemic administration of mast cell secretagogue compound 48/80 exacerbated pancreatic carcinoma-induced visceral hypersensitivity in a male BALB/c nude mouse model as assessed by measuring the hunching behavior scores and mechanical withdrawal response frequency evoked by von Frey stimulation. In contrast, the mast cell stabilizer ketotifen dose-dependently alleviated pancreatic cancer pain. In addition, we observed incomplete development of abdominal mechanical hyperalgesia and hunching behavior in mast cell–deficient mice with pancreatic carcinoma. However, ketotifen did not further attenuate visceral hypersensitivity in mast cell–deficient mice with carcinoma. Finally, we confirmed that intraplantar injection of pericarcinoma supernatants from BALB/c nude mice but not mast cell–deficient mice caused acute somatic nociception. In conclusion, our findings suggest that mast cells contribute to pancreatic carcinoma-induced visceral hypersensitivity through enrichment and degranulation in pericarcinoma tissues. The inhibition of mast cell degranulation may be a potential strategy for the therapeutic treatment of pancreatic carcinoma-induced chronic visceral pain.

Association of the Polymorphism of rs1799822 on Carnitine Palmitoyltransferase II Gene with Severe Enterovirus 71 Encephalitis in Chinese Children

Abstract

Mutations of the CPT2 gene cause CPT2 deficiency and affect the β-oxidation of fatty acids. This study examined the consequence of a polymorphism of rs1799822 in the CPT2 gene with respect to EV71 encephalitis in Chinese children. The study included 406 cases of both mild and severe EV71 infection diagnosed by RT-PCR, together with controls (n = 348). We used an improved multiplex ligation detection reaction technique to detect the polymorphism of rs1799822 in the CPT2 gene. The frequency of the (AG+GG) genotype and G allele in the EV71 infection group and in the severe EV71 encephalitis group was significantly lower than in the control group (p = 0.012 vs. p = 0.005, and p = 0.022 vs. p = 0.006, respectively). The frequency of the (AG+GG) genotype and G allele in the severe EV71 encephalitis group was markedly lower than in the mild EV71 encephalitis group (p = 0.045, p = 0.033). The ATP levels in the blood of the (AG+GG) genotype were distinctly higher than in the AA genotype in mild and severe EV71 encephalitis patients (P = 0.037, P = 0.040). A polymorphism of rs1799822 in the CPT2 gene is associated with the severity of EV71 encephalitis and may be one of the protection factors of severe EV71 encephalitis.

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