Background
This study examines the predictive value of a novel systemic immune‐inflammation index (SII, platelet × neutrophil/lymphocyte ratio) in coronary artery disease (CAD) patients.
Methods
A ...total of 5602 CAD patients who had undergone a percutaneous coronary intervention (PCI) were enrolled. They were divided into two groups by baseline SII score (high SII vs low SII) to analyse the relationship between SII groups and the long‐term outcome. The primary outcomes were major cardiovascular events (MACE) which includes nonfatal myocardial infarction (MI), nonfatal stroke and cardiac death. Secondary outcomes included a composite of MACE and hospitalization for congestive heart failure.
Results
An optimal SII cut‐off point of 694.3 × 109 was identified for MACE in the CAD training cohort (n = 373) and then verified in the second larger CAD cohort (n = 5602). Univariate and multivariate analyses showed that a higher SII score (≥694.3) was independently associated with increased risk of developing cardiac death (HR: 2.02; 95% CI: 1.43‐2.86), nonfatal MI (HR: 1.42; 95% CI: 1.09‐1.85), nonfatal stroke (HR: 1.96; 95% CI: 1.28‐2.99), MACE (HR: 1.65; 95% CI: 1.36‐2.01) and total major events (HR: 1.53; 95% CI: 1.32‐1.77). In addition, the SII significantly improved risk stratification of MI, cardiac death, heart failure, MACE and total major events than conventional risk factors in CAD patients by the significant increase in the C‐index (P < .001) and reclassification risk categories by significant NRI (P < .05) and IDI (P < .05).
Conclusions
SII had a better prediction of major cardiovascular events than traditional risk factors in CAD patients after coronary intervention.
Alterations in RNA levels are frequently reported in brain of subjects diagnosed with autism, schizophrenia, depression, and other psychiatric diseases, but it remains unclear whether the underlying ...molecular pathology involves changes in gene expression, as opposed to alterations in messenger RNA processing. Pre-clinical studies have revealed that stress, drugs, and a variety of other environmental factors lead to changes in RNA levels in brain via epigenetic mechanisms, including modification of histone proteins. A number of site-specific modifications of the nucleosome core histones—including the trimethylated forms of histone H3 lysines K4, K9, and K27—are of particular interest for postmortem research, because these marks differentiate between active and inactive chromatin and seem to remain relatively stable during tissue autolysis. Therefore, histone methylation profiling at promoter regions could provide important clues about mechanisms of gene expression in human brain during development and in disease. Intriguingly, mutations within the genes encoding the H3K9-specific methyltransferase, EHMT1 , and the H3K4-specific histone demethylase, JARID1C/SMCX , have been linked to mental retardation and autism, respectively. In addition, the H3K4-specific methyltransferase, MLL1 , is essential for hippocampal synaptic plasticity and might be involved in cortical dysfunction of some cases of schizophrenia. Together, these findings emphasize the potential significance of histone lysine methylation for orderly brain development and also as a molecular toolbox to study chromatin function in postmortem tissue.
Angelman syndrome, a severe neurodevelopmental disorder, is primarily caused by mutations or deletions of maternally inherited ubiquitin protein ligase E3A (UBE3A). Activation of the silenced ...paternal copy of UBE3A can occur with pharmacological perturbation; however, an environmental approach has not been examined. Here, we found Ube3a is highly expressed in embryonic and early neonatal mouse retina and is maternally‐, but not paternally‐, expressed in ganglion cells, amacrine cells, and horizontal cells. Moreover, we analyzed UBE3A expression in the retina and visual cortex of postnatal day 28 mice (P28) following exposure to light emissions from white compact‐fluorescent bulbs or blue light‐emitting diodes from postnatal day 0 (P0) to 28 (P28), encompassing a crucial phase of visual system development. We found higher levels of Ube3a RNA and protein in the retina, but not visual cortex compared with tissues from P28 mice exposure to typical lighting (controls). Levels of both paternal‐ and maternal‐UBE3A protein in mouse retina were higher than controls in P28 mice exposed to white or blue light. Moreover, levels of open and repressive chromatin structures, indicated by histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3), respectively, were increased in the Ube3a promoter from mouse retina exposed to white or blue light. Our findings strongly suggest that extended exposure to white or blue light constitutes a substantial environmental factor that can effectively promote UBE3A expression within the central nervous system.
We found higher Ube3a expression in the retina of P28 mice exposed to intense white or blue light (760–800 lux) compared with mice exposure to typical lighting (control, 30–60 lux). Levels of both paternal‐ and maternal‐UBE3A protein in mouse retina were higher than controls. Levels of open and repressive chromatin structures, indicated by histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3), respectively, were also increased in the Ube3a promoter from mouse retina. Our findings suggest that extended exposure to intense white or blue light constitutes a substantial environmental factor that can effectively promote UBE3A expression.
Dysfunction of prefrontal cortex in schizophrenia includes changes in GABAergic mRNAs, including decreased expression of GAD1, encoding the 67 kDa glutamate decarboxylase (GAD67) GABA synthesis ...enzyme. The underlying molecular mechanisms remain unclear. Alterations in DNA methylation as an epigenetic regulator of gene expression are thought to play a role but this hypothesis is difficult to test because no techniques are available to extract DNA from GAD1 expressing neurons efficiently from human postmortem brain. Here, we present an alternative approach that is based on immunoprecipitation of mononucleosomes with anti-methyl-histone antibodies differentiating between sites of potential gene expression as opposed to repressive or silenced chromatin. Methylation patterns of CpG dinucleotides at the GAD1 proximal promoter and intron 2 were determined for each of the two chromatin fractions separately, using a case-control design for 14 schizophrenia subjects affected by a decrease in prefrontal GAD1 mRNA levels. In controls, the methylation frequencies at CpG dinucleotides, while overall higher in repressive as compared to open chromatin, did not exceed 5% at the proximal GAD1 promoter and 30% within intron 2. Subjects with schizophrenia showed a significant, on average 8-fold deficit in repressive chromatin-associated DNA methylation at the promoter. These results suggest that chromatin remodeling mechanisms are involved in dysregulated GABAergic gene expression in schizophrenia.
Topoisomerases are expressed throughout the developing and adult brain and are mutated in some individuals with autism spectrum disorder (ASD). However, how topoisomerases are mechanistically ...connected to ASD is unknown. Here we find that topotecan, a topoisomerase 1 (TOP1) inhibitor, dose-dependently reduces the expression of extremely long genes in mouse and human neurons, including nearly all genes that are longer than 200 kilobases. Expression of long genes is also reduced after knockdown of Top1 or Top2b in neurons, highlighting that both enzymes are required for full expression of long genes. By mapping RNA polymerase II density genome-wide in neurons, we found that this length-dependent effect on gene expression was due to impaired transcription elongation. Interestingly, many high-confidence ASD candidate genes are exceptionally long and were reduced in expression after TOP1 inhibition. Our findings suggest that chemicals and genetic mutations that impair topoisomerases could commonly contribute to ASD and other neurodevelopmental disorders.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Expression of brain-derived neurotrophic factor (BDNF) is developmentally regulated in prefrontal cortex (PFC). The underlying molecular mechanisms, however, remain unclear. Here, we explore the role ...of microRNAs (miRNAs) as post-transcriptional inhibitors of BDNF. A sequential approach involving in silico, miRNA microarray, in situ hybridization and qRT–PCR studies identified a group of 10 candidate miRNAs, segregating into five miRNA families (miR-30a-5p/b/c/d, miR-103/107, miR-191, miR-16/195, miR-495), which exhibited distinct developmental and lamina-specific expression in human PFC. Luciferase assays confirmed that at least two of these miRNAs, miR-30a-5p and miR-195, target specific sequences surrounding the proximal polyadenylation site within BDNF 3′-untranslated region. Furthermore, neuronal overexpression of miR-30a-5p, a miRNA enriched in layer III pyramidal neurons, resulted in down-regulation of BDNF protein. Notably, a subset of seven miRNAs, including miR-30a-5p, exhibited an inverse correlation with BDNF protein levels in PFC of subjects age 15–84 years. In contrast, the role of transcriptional mechanisms was more apparent during the transition from fetal to childhood and/or young adult stages, when BDNF mRNA up-regulation was accompanied by similar changes in (open chromatin-associated) histone H3-lysine 4 methylation at BDNF gene promoters I and IV. Collectively, our data highlight the multiple layers of regulation governing the developmental expression of BDNF in human PFC and suggest that miRNAs are involved in the fine-tuning of this neurotrophin particularly in adulthood.
Angelman syndrome is a severe neurodevelopmental disorder caused by deletion or mutation of the maternal allele of the ubiquitin protein ligase E3A (UBE3A). In neurons, the paternal allele of UBE3A ...is intact but epigenetically silenced, raising the possibility that Angelman syndrome could be treated by activating this silenced allele to restore functional UBE3A protein. Using an unbiased, high-content screen in primary cortical neurons from mice, we identify twelve topoisomerase I inhibitors and four topoisomerase II inhibitors that unsilence the paternal Ube3a allele. These drugs included topotecan, irinotecan, etoposide and dexrazoxane (ICRF-187). At nanomolar concentrations, topotecan upregulated catalytically active UBE3A in neurons from maternal Ube3a-null mice. Topotecan concomitantly downregulated expression of the Ube3a antisense transcript that overlaps the paternal copy of Ube3a. These results indicate that topotecan unsilences Ube3a in cis by reducing transcription of an imprinted antisense RNA. When administered in vivo, topotecan unsilenced the paternal Ube3a allele in several regions of the nervous system, including neurons in the hippocampus, neocortex, striatum, cerebellum and spinal cord. Paternal expression of Ube3a remained elevated in a subset of spinal cord neurons for at least 12 weeks after cessation of topotecan treatment, indicating that transient topoisomerase inhibition can have enduring effects on gene expression. Although potential off-target effects remain to be investigated, our findings suggest a therapeutic strategy for reactivating the functional but dormant allele of Ube3a in patients with Angelman syndrome.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
RTL1/PEG11, which has been associated with anxiety disorders, is a retrotransposon-derived imprinted gene in the placenta. However, imprinting patterns and functions of RTL1 in the brain ...have not been well-investigated. We found Rtl1 was paternally, but not maternally, expressed in brain stem, thalamus, and hypothalamus of mice, and imprinting status of RTL1 was maintained in human brain. Paternal Rtl1 knockout (Rtl1m+/p-) mice had higher neonatal death rates due to impaired suckling, and low body weights beginning on embryonic day 16.5. High paternal expression of Rtl1 was detected in the locus coeruleus (LC) and Rtl1m+/p- mice showed an increased delay in time of onset for action potentials and inward currents with decreased neuronal excitability of LC neurons. Importantly, Rtl1m+/p- mice exhibited behaviors associated with anxiety, depression, fear-related learning and memory, social dominance, and low locomotor activity. Taken together, our findings demonstrate RTL1 is imprinted in brain, mediates emotional and social behaviors, and regulates excitability in LC neurons.
•MIR125B1 is not imprinted in human brain.•miR125b-1 displays distinct spatial expression in mice.•miR125b-1 is down-regulated during brain development of mice.
Genomic imprinting is a predominantly ...brain and placenta-specific epigenetic process that contributes to parent-of-origin-specific gene expression. While microRNAs are highly expressed in the brain, their imprinting status in this tissue remains poorly studied. Previous research demonstrated that Mir125b-2 is imprinted in the human brain and regulates hippocampal circuits and functions in mice. However, the imprinting status of another isoform of miR125b, Mir125b-1, in the human brain, as well as its spatiotemporal expression patterns in mice, have not been elucidated. Here, we show MIR125B1 is not imprinted in the human brain. Moreover, miR-125b-1 was highly expressed in the brains of mice. Furthermore, miR-125b-1 was down-regulated during brain development in mice. Specifically, miR-125b-1 displayed preferential expression in the olfactory bulb, thalamus, and hypothalamus of the mouse brain. Notably, miR-125b-1 was enriched in GABAergic neurons, particularly somatostatin-expressing GABAergic neurons, compared with glutamatergic neurons. Taken together, our findings provide the imprinting status and comprehensive spatiotemporal expression profiling of Mir125b-1 in the brain.
The variability of blood pressure (BPV) has been suggested as a clinical indicator for cognitive dysfunction, yet the results from clinical studies are variable. This study investigated the ...relationship between BPV and the risk of cognitive decline or dementia. Bibliographic databases, including PubMed, Scopus, and Embase, were searched systematically for longitudinal cohort studies with BPV measurements and neuropsychological examinations or dementia diagnosis. A traditional meta‐analysis with subgroup analysis, and a further dose‐response meta‐analysis were conducted. Twenty cohort studies with 7 924 168 persons were included in this review. The results showed that a higher systolic BPV (SBPV), when measured with the coefficient of variation (SBP‐CV) or standard deviation (SBP‐SD), was associated with a higher risk of all‐cause dementia diagnosis but not incidence of cognitive decline on neuropsychological examinations. In subgroup analysis, the effect was more prominent when using BPV of shorter timeframes, during shorter follow‐ups, or among the elderly aged more than 65 years. No dose‐response relationship could be found. Our study suggested possible positive associations between SBPV and the risk of dementia. Further studies are required to validate these findings.
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