Τρίτη 19 Νοεμβρίου 2019

LMNA-Related Muscular Dystrophy with Clinical Intrafamilial Variability

Abstract

The LMNA gene is associated to a huge broad of phenotypes, including congenital Emery-Dreifuss muscular dystrophy and late-onset LMNA-related muscular dystrophy. In these forms, muscle weakness, contractures, and cardiac impairment are common. In an autosomal dominant pedigree including 5 affected patients, NGS molecular analysis performed in 6 relatives identifies the heterozygous c.1129C>T p.Arg377Cys variant in the exon 6 of the LMNA gene in three of them. Clinical, laboratorial, imaging investigation of these affected patients showed a significant clinical variability: the father presented subclinical imaging muscular dystrophy masqueraded as radiculopathy. One of his sons presented cardiac arrhythmia, muscular weakness, elbow contractures, and intranuclear pseudoinclusions on muscle biopsy. A second son presented only decreased tendon reflexes. Two other brothers presenting myalgia and cramps were not carriers of the same mutation in the LMNA gene. Early diagnosis, considering these variable phenotype and genotype, is important for genetic counseling, as well as cardiac, and rehabilitation management.

Age- and Nicotine-Associated Gene Expression Changes in the Hippocampus of APP/PS1 Mice

Abstract

The etiology of Alzheimer’s disease (AD) has been intensively studied. However, little is known about the molecular alterations in early-stage and late-stage AD. Hence, we performed RNA sequencing and assessed differentially expressed genes (DEGs) in the hippocampus of 18-month and 7-month-old APP/PS1 mice. Moreover, the DEGs induced by treatment with nicotine, the nicotinic acetylcholine receptor agonist that is known to improve cognition in AD, were also analyzed in old and young APP/PS1 mice. When comparing old APP/PS1 mice with their younger littermates, we found an upregulation in genes associated with calcium overload, immune response, cancer, and synaptic function; the transcripts of 14 calcium ion channel subtypes were significantly increased in aged mice. In contrast, the downregulated genes in aged mice were associated with ribosomal components, mitochondrial respiratory chain complex, and metabolism. Through comparison with DEGs in normal aging from previous reports, we found that changes in calcium channel genes remained one of the prominent features in aged APP/PS1 mice. Nicotine treatment also induced changes in gene expression. Indeed, nicotine augmented glycerolipid metabolism, but inhibited PI3K and MAPK signaling in young mice. In contrast, nicotine affected genes associated with cell senescence and death in old mice. Our study suggests a potential network connection between calcium overload and cellular signaling, in which additional nicotinic activation might not be beneficial in late-stage AD.

LPP and RYR2 Gene Polymorphisms Correlate with the Risk and the Prognosis of Astrocytoma

Abstract

Astrocytoma is the most common neuroepithelial tumor. Genetic factors play an important role in the development and prognosis of astrocytoma. So this study focuses on the impact of LPP and RYR2 genes on the occurrence and prognosis of astrocytoma. Rs12594 and rs16835904 in the RYR2 gene and rs1064607, rs3796283, and rs2378456 in the LPP gene were selected and genotyped using Agena MassARRAY in 365 patients and 379 healthy populations. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined using logistic regression to assess the influence of gene polymorphisms on occurrence of astrocytoma. The association between genotype and survival outcomes was performed by the Kaplan-Meier method, the log-rank test, and the Cox regression analysis. The survival rates of patients receiving gross total resection and postoperative chemotherapy were higher than patients receiving near total resection and subtotal resection and without chemotherapy. In recessive model, the patients with LPP rs2378456 CC genotype increased the risk of astrocytoma (OR = 1.43, 95% CI 1.01–2.02, p = 0.042). Stratified analysis shows that RYR2 rs16835904 TC-TT genotype facilitated the risk of astrocytoma in male (OR = 1.93, 95% CI 1.15–3.24, p = 0.011). Cox regression analysis shows that RYR2 rs12594 AA genotype and AG genotype were associated with OS of astrocytoma (AG genotype: HR = 1.62, 95% CI 1.04–2.53, p = 0.034; AA genotype: HR = 1.70, 95% CI 1.08–2.68, p = 0.021). RYR2 and LPP genes were found to affect the occurrence and prognosis of astrocytoma.

Assessment of Apoptosis Pathway in Peripheral Blood of Autistic Patients

Abstract

Autism spectrum disorder (ASD) includes a number of severe neurodevelopmental disorders known by defects in social interaction, impaired verbal and non-verbal interactions, and stereotypic activities and limited interests. Dysregulation of apoptotic pathways have been demonstrated in brain tissues of affected individuals. In the present study, we evaluated expression levels of apoptosis-related genes and miRNAs in peripheral blood of ASD patients compared with healthy subjects. Transcript levels of BCL2CASP8, and hsa-29c-3p were significantly lower in total ASD patients compared with total normal children (P values = 0.003, 0.002, and 0.01 respectively). When sex of study participants was considered in the analysis, the difference in transcript levels of these genes was significant only in male subjects. Peripheral expression of BCL2 and hsa-29c-3p had 100% sensitivity 92% specificity in ASD diagnosis. The diagnostic power of combination of transcript levels of these genes was estimated to be 78% based on the calculated AUC value. The present study provides evidences for dysregulation of apoptotic pathways in peripheral blood of ASD patients and suggests certain apoptosis-related genes as biomarkers in this regard.

Sevoflurane Exerts an Anti-depressive Action by Blocking the HMGB1/TLR4 Pathway in Unpredictable Chronic Mild Stress Rats

Abstract

This study was performed to investigate whether sevoflurane has an anti-depressive effect and to elucidate its underlying mechanism. Unpredictable chronic mild stress (uCMS)–treated rats were used for inducing depressive-like behavior and subsequently treated with sevoflurane. A forced swimming test was conducted with the rats. An ELISA was performed to detect the levels of brain-derived neurotrophic factor (BDNF) and inflammatory cytokines in the hippocampus of the rats. Differentially expressed genes in uCMS and normal rats were analyzed by microarray. qRT-PCR, western blot, and flow cytometry, and gain and loss of function measurements were carried out to determine the association between sevoflurane and the HMGB1/TLR4 pathway. A forced swimming test with uCMS rats exposed to sevoflurane demonstrated that a 2% sevoflurane treatment resulted in an anti-depressive effect. In addition, ELISAs of TNF-α (tumor necrosis factor-α), IL-1β (interleukin-1 beta), IL-6 (interleukin-6), and BDNF supported an effect of sevoflurane on inflammatory cytokines and a neurotrophic factor. HMGB1 was dramatically induced in uCMS rats, and the HMGB1/TLR4 pathway was implicated in sevoflurane exposure. A 2% sevoflurane treatment resulted in a restoration of HMGB1/TLR4 signaling and expression of cytokines and BDNF. HMGB1 overexpression partially prevented the protective effect of 2% SF, suggesting sevoflurane protects uCMS rats.

PINK1 Silencing Modifies Dendritic Spine Dynamics of Mouse Hippocampal Neurons

Abstract

PTEN-induced kinase 1 (PINK1) mutations can cause early-onset Parkinson’s disease and patients are likely to develop cognitive decline, depression, and dementia. Several neurophysiological studies have demonstrated PINK1 deficiency impairs striatal and hippocampal presynaptic plasticity. Dendritic spine postsynaptic abnormalities are common in neurological diseases; however, whether PINK1 silencing modifies dendritic spine dynamics of hippocampal neurons is unclear. To address this question, confocal images of mouse cultured hippocampal neurons transfected with plasmids to silence PINK1 were analyzed. These studies revealed that PINK1 silencing increased density of thin spines and reduced head size of stubby spines. Immunoblotting analysis uncovered that PINK1 silencing decreased expression of postsynaptic density proteins (PSD95 and Shank) and glutamate receptors (NR2B and mGluR5). We also found PINK1 silencing regulated dendritic spine morphology by actin regulatory proteins (RhoGAP29 and ROCK2) and regulated neuronal survival by decreased Akt activation. These results suggest PINK1 may regulate postsynaptic plasticity in hippocampal neurons generating presymptomatic alterations in dendritic spines that eventually could lead to the neurodegeneration and cognitive decline often seen in Parkinson’s disease.

Role of Melatonin Receptors in Hyperthermia-Induced Acute Seizure Model of Rats

Abstract

Melatonin is a neurohormone that has anticonvulsant activity in different experimental seizure models including hyperthermic febrile seizure. However, the mechanisms of this effect are not clear at the receptor level. The aim of the study was to determine which melatonin receptors involve in the hyperthermic febrile seizure model. 22–30 days Wistar male rats were used, and in children, it corresponds to 1.5–2 years. Groups were performed as (1) control, (2) ethanol/saline, (3) DMSO, (4) melatonin (MT), (5) MT + luzindole (LUZ), (6) MT + K-185, (7) MT + prazosin (PRZ), (8) MT + LUZ + K-185, (9) MT + LUZ + PRZ, (10) MT + K-185 + PRZ, and (11) MT + LUZ + PRZ + K-185. The hyperthermic febrile seizure pattern was established by keeping the rats in 45 °C hot water, and the latency, duration, and severity of seizures were determined in all groups. MT, LUZ, K-185, and PRZ were given 15, 45, 15, and 30 min before the induction of seizure, respectively. It was observed that melatonin shortened the duration of seizure, reduced the severity, and did not affect latency and that these effects were not completely blocked by receptor antagonists when compared with control, ethanol/saline, and DMSO groups. In conclusion, the fact that the anticonvulsant effect of melatonin is not completely blocked by all melatonin receptor antagonists. We can conclude that a multimodal mechanism may be responsible for the effect of melatonin receptors alone on the anticonvulsant effect of melatonin. It will be useful to design new pharmacological studies to make the subject clear.

Identification and In Silico Characterization of a Novel Point Mutation within the Phosphatidylinositol Glycan Anchor Biosynthesis Class G Gene in an Iranian Family with Intellectual Disability

Abstract

Intellectual disability (ID) is characterized by limited mental ability and adaptive behavior that imposes a heavy burden on the patients’ families and the health care system. This study was aimed at determining the molecular aspect of nonsyndromic ID, in a family from South Khorasan Province in Iran. Exome sequencing was performed, as well as complete clinical examinations of the family. Afterward, in silico studies have been done to examine the changes that occurred in the protein structure, in association with the ID phenotype. The PIGG (NC_000004.12) mutation was found on Chr 4:517639G>A, and this chromosomal location was proposed as the disorder-causing variant. This Arg658Gln alteration was confirmed by Sanger sequencing, using specific primers for PIGG. In conclusion, our study indicated a novel mutation in the PIGG in the affected family. This mutation is a novel variant (p. R658Q) with an autosomal recessive inheritance pattern. These findings could improve genetic counseling in the future.

Targeted Multiple Reaction Monitoring Analysis of CSF Identifies UCHL1 and GPNMB as Candidate Biomarkers for ALS

Abstract

The neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD) share some common molecular deficits including disruption of protein homeostasis leading to disease-specific protein aggregation. While insoluble protein aggregates are the defining pathological confirmation of diagnosis, patient stratification based on early molecular etiologies may identify distinct subgroups within a clinical diagnosis that would respond differently in therapeutic development programs. We are developing targeted multiple reaction monitoring (MRM) mass spectrometry methods to rigorously quantify CSF proteins from known disease genes involved in lysosomal, ubiquitin-proteasomal, and autophagy pathways. Analysis of CSF from 21 PD, 21 ALS, and 25 control patients, rigorously matched for gender, age, and age of sample, revealed significant changes in peptide levels between PD, ALS, and control. In patients with PD, levels of two peptides for chromogranin B (CHGB, secretogranin 1) were significantly reduced. In CSF of patients with ALS, levels of two peptides from ubiquitin carboxy-terminal hydrolase like protein 1 (UCHL1) and one peptide each for glycoprotein non-metastatic melanoma protein B (GPNMB) and cathepsin D (CTSD) were all increased. Analysis of patients with ALS separated into two groups based on length of survival after CSF sampling revealed that the increases in GPNMB and UCHL1 were specific for short-lived ALS patients. While analysis of additional cohorts is required to validate these candidate biomarkers, this study suggests methods for stratification of ALS patients for clinical trials and identifies targets for drug efficacy measurements during therapeutic development.

Upregulated Expression of CUX1 Correlates with Poor Prognosis in Glioma Patients: a Bioinformatic Analysis

Abstract

Cut-like homeobox-1 (CUX1) is expressed in the upper layer of the cortex and participates in DNA replication, cell cycle control, and DNA repair. It has been shown to be involved in the proliferation of various types of solid tumors. The aims of this study were to explore the relationship between CUX1 expression and the prognosis of glioma by performing a series of functional experiments and bioinformatic analyses. Firstly, we found that CUX1 expression levels differed among patients with different grades of gliomas, and they were significantly correlated with the prognosis of glioma patients according to an analysis of data from a public database. qRT-PCR, western blotting, and immunohistochemical analysis of CUX1 were performed to demonstrate that the expression of CUX1 was positively correlated with the glioma WHO grade (P < 0.05) and several malignant clinical pathological parameters, including Ki67 and P53mut. In addition, the multivariate Cox regression and Kaplan–Meier curves showed that CUX1 expression exerted predictive value for overall survival. Finally, to further investigate the functions of CUX1, we identified CUX1-associated genes and, though GO/KEGG analysis, their associated biological functions and signaling pathways; the results suggested that the activity of CUX1 might be exerted via the JAK-STAT pathway or other key regulators of the cell cycle to promote proliferation, inflammation, and chemotherapy resistance in glioma. Taken together, these results indicate that CUX1 is a potential biomarker of malignancy and prognosis and may serve as a potential therapeutic target for glioma patients.

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