BACKGROUND AND PURPOSE: The long-term impact of gadolinium retention in the dentate nuclei of patients undergoing administration of seriate gadolinium-based contrast agents is still widely unexplored. The aim of this study was to evaluate the impact of gadolinium retention on motor and cognitive disability in patients with MS during long-term follow-up.MATERIALS AND METHODS: In this retrospective study, clinical data were obtained from patients with MS followed in a single center from 2013 to 2022 at different time points. These included the Expanded Disability Status Scale score to evaluate motor impairment and the Brief International Cognitive Assessment for MS battery to investigate cognitive performances and their respective changes with time. The association with qualitative and quantitative MR imaging signs of gadolinium retention (namely, the presence of dentate nuclei T1-weighted hyperintensity and changes in longitudinal relaxation R1 maps, respectively) was probed using different General Linear Models and regression analyses.RESULTS: No significant differences in motor or cognitive symptoms emerged between patients showing dentate nuclei hyperintensity and those without visible changes on T1WIs (P = .14 and 0.92, respectively). When we tested possible relationships between quantitative dentate nuclei R1 values and both motor and cognitive symptoms, separately, the regression models including demographic, clinical, and MR imaging features explained 40.5% and 16.5% of the variance, respectively, without any significant effect of dentate nuclei R1 values (P = .21 and 0.30, respectively).CONCLUSIONS: Our findings suggest that gadolinium retention in the brains of patients with MS is not associated with long-term motor or cognitive outcomes.
FXYD1 is a key protein controlling ion channel transport. FXYD1 exerts its function by regulating Na + /K + -ATPase activity, mainly in brain and cardiac tissues. Alterations of the expression level of the FXYD1 protein cause diastolic dysfunction and arrhythmias in heart and decreased neuronal dendritic tree and spine formation in brain. Moreover, FXYD1, a target of MeCP2, plays a crucial role in the pathogenesis of the Rett syndrome, a neurodevelopmental disorder. Thus, the amount of FXYD1 must be strictly controlled in a tissue specific manner and, likely, during development. Epigenetic modifications, particularly DNA methylation, represent the major candidate mechanism that may regulate Fxyd1 expression. In the present study, we performed a comprehensive DNA methylation analysis and mRNA expression level measurement of the two Fxyd1 transcripts, Fxyd1a and Fxyd1b, in brain and heart tissues during mouse development. We found that DNA methylation at Fxyd1a increased during brain development and decreased during heart development along with coherent changes in mRNA expression levels. We also applied ultra-deep methylation analysis to detect cell to cell methylation differences and to identify possible distinct methylation profile (epialleles) distribution between heart and brain and in different developmental stages. Our data indicate that the expression of Fxyd1 transcript isoforms inversely correlates with DNA methylation in developing brain and cardiac tissues suggesting the existence of a temporal-specific epigenetic program. Moreover, we identified a clear remodeling of epiallele profiles which were distinctive for single developmental stage both in brain and heart tissues.
One of the characteristics of the SARS-CoV-2 infection in Italy is the significant regional difference in terms of lethality and mortality. These geographical variances were clear in the first wave and confirmed in the second one as well. The study aimed to analyze the correlation between regional differences in COVID-19 mortality and different regional care models, by retrospectively analyzing the association between the Italian COVID-19 deaths and the number of hospital beds, long-term care facilities, general practitioners (GPs), and the health expenditure per capita. The period considered was from 1 March 2020 to 1 March 2021. The number of hospital beds (p < 0.0001) and the number of GPs (p = 0.0094) significantly predicted the COVID-19 death rate. The Italian regions with a higher number of hospital beds and a lower number of GPs showed a higher number of deaths. Multivariate analyses confirmed the results. The Italian regions with a higher amount of centralized healthcare, as represented by the number of hospital beds, experienced a higher number of deaths, while the regions with greater community support, as exemplified by the number of the GPs, faced higher survival. These results suggest the need for a change in the current healthcare system organization.
SUMMARY: Quantitative MR imaging techniques allow evaluating different aspects of brain microstructure, providing meaningful information about the pathophysiology of damage in CNS disorders. In the study of patients with MS, quantitative MR imaging techniques represent an invaluable tool for studying changes in myelin and iron content occurring in the context of inflammatory and neurodegenerative processes. In the first section of this review, we summarize the physics behind quantitative MR imaging, here defined as relaxometry and quantitative susceptibility mapping, and describe the neurobiological correlates of quantitative MR imaging findings. In the second section, we focus on quantitative MR imaging application in MS, reporting the main findings in both the gray and white matter compartments, separately addressing macroscopically damaged and normal-appearing parenchyma.
ABSTRACT DNA methylation is an epigenetic mark implicated in crucial biological processes. Most of the knowledge about DNA methylation is based on bulk experiments, in which DNA methylation of genomic regions is reported as average methylation. However, average methylation does not inform on how methylated cytosines are distributed in each single DNA molecule. Here, we propose Methylation Class (MC) profiling as a genome-wide approach to the study of DNA methylation heterogeneity from bulk bisulfite sequencing experiments. The proposed approach is built on the concept of MCs, groups of DNA molecules sharing the same number of methylated cytosines. The relative abundances of MCs from sequencing reads incorporates the information on the average methylation, and directly informs on the methylation level of each molecule. By applying our approach to publicly available bisulfite-sequencing datasets, we individuated cell-to-cell differences as the prevalent contributor to methylation heterogeneity. Moreover, we individuated signatures of loci undergoing imprinting and X-inactivation, and highlighted differences between the two processes. When applying MC profiling to compare different conditions, we identified methylation changes occurring in regions with almost constant average methylation. Altogether, our results indicate that MC profiling can provide useful insights on the epigenetic status and its evolution at multiple genomic regions.
Isolated, paced, isovolumically beating, neonatal pig (≈2 days) hearts were perfused with a crystalloid solution during four periods: (1) baseline, HR 150 bpm; (2) HR-response curves, HR 150–360 bpm; (3) tachycardia, HR 300 bpm; and (4) posttachycardia, HR 150 bpm. Group I was studied with glucose (5.5 mM) as the sole substrate. During baseline, left ventricular peak systolic pressure (PSP) averaged 123 ± 7 mm Hg; end diastolic pressure (EDP), 4.9 ± 0.4 mm Hg; relaxation time constant (Tau), 29.5 ± 3.9 ms; glucose oxidation (14CO2from [14C]glucose), 1535 ± 96 nmol/min/gdry; and myocardial oxygen consumption (MVO2), 17.4 ± 0.4 μmol/min/gdry. During tachycardia, PSP was 83 ± 4* mm Hg; EDP, 9.8 ± 1.7* mm Hg; Tau, 29.9 ± 5.4 ms; glucose oxidation, 1921 ± 136* nmol/min/gdry; and MVO2, 21.1 ± 0.7* μmol/min/gdry(*different from baseline,P< 0.05). Posttachycardia, all parameters returned to near baseline values, except EDP, which remained elevated. Group II was studied with glucose (5.5 mM) and palmitate (0.55 mM). When compared to those of Group I, the mechanical responses were similar. During baseline, glucose oxidation was 149 ± 24 nmol/min/gdry; palmitate oxidation, 343 ± 28 nmol/min/gdry; and MVO2, 18.4 ± 0.7 μmol/min/gdry. Both oxidation rates increased significantly during tachycardia, indicating aerobic metabolic reserve. Posttachycardia, glucose oxidation returned to baseline, but palmitate oxidation remained elevated, suggesting enhanced beta oxidation. Group III was perfused with glucose (5.5 mM) and pyruvate (5.5 mM), along with iodoacetate (50 μM) to inhibit glycolysis. PSP was maintained, but Tau (HRs ≥ 270 bpm) and EDP (HRs ≥ 180 bpm) markedly increased. In conclusion, for the isovolumically beating, neonatal pig heart stressed with tachycardia: (1) PSP decreases, EDP increases, and Tau remains relatively constant; (2) substrate oxidation is enhanced; and (3) glycolysis, rather than glucose oxidation, appears to be important for supporting ventricular diastolic function.
The bidirectional microbiota–gut–brain axis has raised increasing interest over the past years in the context of health and disease, but there is a lack of information on molecular mechanisms underlying this connection. We hypothesized that change in microbiota composition may affect brain epigenetics leading to long-lasting effects on specific brain gene regulation. To test this hypothesis, we used Zebrafish (Danio Rerio) as a model system. As previously shown, treatment with high doses of probiotics can modulate behavior in Zebrafish, causing significant changes in the expression of some brain-relevant genes, such as BDNF and Tph1A. Using an ultra-deep targeted analysis, we investigated the methylation state of the BDNF and Tph1A promoter region in the brain and gut of probiotic-treated and untreated Zebrafishes. Thanks to the high resolution power of our analysis, we evaluated cell-to-cell methylation differences. At this resolution level, we found slight DNA methylation changes in probiotic-treated samples, likely related to a subgroup of brain and gut cells, and that specific DNA methylation signatures significantly correlated with specific behavioral scores.
The multidimensional analysis of brain MR images, including radiomic features and clinicodemographic data, is highly informative of the clinical status of patients with multiple sclerosis, representing a promising approach to bridge the gap between conventional imaging and disability. BACKGROUND AND PURPOSE: Conventional MR imaging explains only a fraction of the clinical outcome variance in multiple sclerosis. We aimed to evaluate machine learning models for disability prediction on the basis of radiomic, volumetric, and connectivity features derived from routine brain MR images. MATERIALS AND METHODS: In this retrospective cross-sectional study, 3T brain MR imaging studies of patients with multiple sclerosis, including 3D T1-weighted and T2-weighted FLAIR sequences, were selected from 2 institutions. T1-weighted images were processed to obtain volume, connectivity score (inferred from the T2 lesion location), and texture features for an atlas-based set of GM regions. The site 1 cohort was randomly split into training (n = 400) and test (n = 100) sets, while the site 2 cohort (n = 104) constituted the external test set. After feature selection of clinicodemographic and MR imaging–derived variables, different machine learning algorithms predicting disability as measured with the Expanded Disability Status Scale were trained and cross-validated on the training cohort and evaluated on the test sets. The effect of different algorithms on model performance was tested using the 1-way repeated-measures ANOVA. RESULTS: The selection procedure identified the 9 most informative variables, including age and secondary-progressive course and a subset of radiomic features extracted from the prefrontal cortex, subcortical GM, and cerebellum. The machine learning models predicted disability with high accuracy (r approaching 0.80) and excellent intra- and intersite generalizability (r ≥ 0.73). The machine learning algorithm had no relevant effect on the performance. CONCLUSIONS: The multidimensional analysis of brain MR images, including radiomic features and clinicodemographic data, is highly informative of the clinical status of patients with multiple sclerosis, representing a promising approach to bridge the gap between conventional imaging and disability.
BACKGROUND AND PURPOSE:Modifications of magnetic susceptibility have been consistently demonstrated in the subcortical gray matter of MS patients, but some uncertainties remain concerning the underlying neurobiological processes and their clinical relevance. We applied quantitative susceptibility mapping and longitudinal relaxation rate relaxometry to clarify the relative contribution of atrophy and iron and myelin changes to deep gray matter damage and disability in MS. MATERIALS AND METHODS:Quantitative susceptibility mapping and longitudinal relaxation rate maps were computed for 91 patients and 55 healthy controls from MR images acquired at 3T. Applying an external model, we estimated iron and myelin concentration maps for all subjects. Subsequently, changes of deep gray matter iron and myelin concentration (atrophy-dependent) and content (atrophy-independent) were investigated globally (bulk analysis) and regionally (voxel-based and atlas-based thalamic subnuclei analyses). The clinical impact of the observed MRI modifications was evaluated via regression models. RESULTS:We identified reduced thalamic (P < .001) and increased pallidal (P < .001) mean iron concentrations in patients with MS versus controls. Global myelin and iron content in the basal ganglia did not differ between the two groups, while actual iron depletion was present in the thalamus (P < .001). Regionally, patients showed increased iron concentration in the basal ganglia (P ≤ .001) and reduced iron and myelin content in thalamic posterior-medial regions (P ≤ .004), particularly in the pulvinar (P ≤ .001). Disability was predicted by thalamic volume (B = -0.341, P = .02), iron concentration (B = -0.379, P = .005) and content (B = -0.406, P = .009), as well as pulvinar iron (B = -0.415, P = .003) and myelin (B = -0.415, P = .02) content, independent of atrophy. CONCLUSIONS:Quantitative MRI suggests an atrophy-related iron increase within the basal ganglia of patients with MS, along with an atrophy-independent reduction of thalamic iron and myelin correlating with disability. Absolute depletions of thalamic iron and myelin may represent sensitive markers of subcortical GM damage, which add to the clinical impact of thalamic atrophy in MS.
DNA methylation alterations are related to multiple molecular mechanisms. The DNA context of CpG sites plays a crucial role in the maintenance and stability of methylation patterns. The quantitative relationship between DNA composition and DNA methylation has been studied in normal as well as pathological conditions, showing that DNA methylation status is highly dependent on the local sequence context. In this work, we describe this relationship by analyzing the DNA sequence context associated to methylation profiles in both physiological and pathological conditions. In particular, we used DNA motifs to describe methylation stability patterns in normal tissues and aberrant methylation events in cancer lesions. In this manuscript, we show how different groups of DNA sequences can be related to specific epigenetic events, across normal and cancer tissues, and provide a thorough structural and functional characterization of these sequences.
Abstract Background The risk of cardiovascular (CV) disease in type 2 diabetes mellitus (T2DM) is highly heterogeneous and an adequate risk stratification is needed. CV risk mainly depends on concomitant risk factors, combined in the metabolic syndrome (MetS). Echocardiography is an useful tool for diagnosis of cardiac organ damage and CV risk stratification in T2DM. Purpose To investigate the effects of MetS on left ventricular (LV) structure and function in patients with T2DM with normal LV ejection fraction (LVEF) and without overt coronary artery disease (CAD) and heart failure symptoms/signs. Methods We prospectively recruited 384 consecutive, uncomplicated T2DM patients. All patients underwent clinical exam, blood sampling and complete echo-Doppler exam, including determination of 2D-echo derived global longitudinal strain (GLS). LV mass index ≥45 g/m^2.7 in women and ≥49 g/m^2.7 in men was used to characterize LV hypertrophy. LV longitudinal dysfunction was assumed for GLS < 20% in absolute values. LV diastolic dysfunction was identified according to 2016 ASE/EACVI recommendations. MetS was defined according to NCEP-ATP III criteria. Significant CAD including previous myocardial infarction, LV systolic dysfunction (= LVEF <50%), hemodinamically significant valvular heart disease, primary cardiomyopathies, permanent atrial fibrillation, glomerular filtration rate <30 ml/min and inadequate echo images were exclusion criteria. The study population was divided according to presence of MetS. Results 66% of the patients (254/384) met the criteria for MetS diagnosis. They had comparable age and heart rate with controls. Diabetic patients with MetS had higher glycated haemoglobin (HbA1c) (7.2 ± 1.3 vs. 6.9 ± 1.0%, p = 0.023) and uric acid (5.5 ± 1.4 vs. 4.9 ± 1.3 mg/dl, p = 0.001) than those without, and lower glomerular filtration rate (69.5 ± 15.0 vs 74.0 ± 12,1 ml/min, p = 0.004). MetS patients showed a higher LV mass index (p < 0.0001) and a greater prevalence of both LV hypertrophy (31.9 vs 12.5%, p < 0.0001) and diastolic dysfunction (52.6 vs. 32.8%, p = 0.007) (Figure). T2DM patients with MetS also had lower GLS (20.6 ± 2.1 vs. 21.9 ± 2.2%, p = 0.001), with a greater prevalence of LV longitudinal dysfunction (38.2 vs. 24.7%, p = 0.049) (Figure). After adjusting for age, T2DM duration, sex, HbA1c, uric acid, LV mass index and LV diastolic dysfunction by a multiple regression analysis in the pooled population, GLS reduction was independently associated with MetS (β coefficient = -0.184, p < 0.02) and LV mass index (β= -0.94, p = 0.04). Conclusion In patients with T2DM, the presence of MetS induces a greater prevalence not only of LV hypertrophy and diastolic dysfunction but also of LV longitudinal deformation impairment. GLS reduction in diabetic patients is associated with MetS independently of confounders including glycemic control and diabetic duration. Abstract 433 Figure. Rate of LV alterations according to MetS
Abstract 8-Oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) is the most common marker of oxidative stress and its accumulation within the genome has been associated with major human health issues such as cancer, aging, cardiovascular and neurodegenerative diseases. The characterization of the different genomic sites where 8-oxodG accumulates and the mechanisms underlying its formation are still poorly understood. Using OxiDIP-seq, we recently derived the genome-wide distribution of 8-oxodG in human non-tumorigenic epithelial breast cells (MCF10A). Here, we identify a subset of human promoters that accumulate 8-oxodG under steady-state condition. 8-oxodG nucleotides co-localize with double strand breaks (DSBs) at bidirectional and CG skewed promoters and their density correlate with RNA Polymerase II co-occupancy and transcription. Furthermore, by performing OxiDIP-seq in quiescent (G0) cells, we found a strong reduction of oxidatively-generated damage in the majority of 8-oxodG-positive promoters in the absence of DNA replication. Overall, our results suggest that the accumulation of 8-oxodG at gene promoters occurs through DNA replication-dependent or -independent mechanisms, with a possible contribution to the formation of cancer-associated translocation events.