Remodeling of the chromatin structure of the facioscapulohumeral muscular dystrophy (FSHD) locus and upregulation of FSHD-related gene 1 (FRG1) expression during human myogenic differentiation

<p>Abstract</p> <p>Background</p> <p>Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant neuromuscular disorder associated with the partial deletion of integral numbers of 3.3 kb D4Z4 DNA repeats within the subtelomere of chromosome 4q. A number of candidate FSHD genes, adenine nucleotide translocator 1 gene (<it>ANT1</it>), FSHD-related gene 1 (<it>FRG1</it>), <it>FRG2 </it>and <it>DUX4c</it>, upstream of the D4Z4 array (FSHD locus), and double homeobox chromosome 4 (<it>DUX4</it>) within the repeat itself, are upregulated in some patients, thus suggesting an underlying perturbation of the chromatin structure. Furthermore, a mouse model overexpressing <it>FRG1 </it>has been generated, displaying skeletal muscle defects.</p> <p>Results</p> <p>In the context of myogenic differentiation, we compared the chromatin structure and tridimensional interaction of the D4Z4 array and <it>FRG1 </it>gene promoter, and <it>FRG1 </it>expression, in control and FSHD cells. The <it>FRG1 </it>gene was prematurely expressed during FSHD myoblast differentiation, thus suggesting that the number of D4Z4 repeats in the array may affect the correct timing of <it>FRG1 </it>expression. Using chromosome conformation capture (3C) technology, we revealed that the <it>FRG1 </it>promoter and D4Z4 array physically interacted. Furthermore, this chromatin structure underwent dynamic changes during myogenic differentiation that led to the loosening of the <it>FRG1</it>/4q-D4Z4 array loop in myotubes. The <it>FRG1 </it>promoter in both normal and FSHD myoblasts was characterized by H3K27 trimethylation and Polycomb repressor complex binding, but these repression signs were replaced by H3K4 trimethylation during differentiation. The D4Z4 sequences behaved similarly, with H3K27 trimethylation and Polycomb binding being lost upon myogenic differentiation.</p> <p>Conclusion</p> <p>We propose a model in which the D4Z4 array may play a critical chromatin function as an orchestrator of <it>in cis </it>chromatin loops, thus suggesting that this repeat may play a role in coordinating gene expression.</p

Expression Profiling of FSHD-1 and FSHD-2 Cells during Myogenic Differentiation Evidences Common and Distinctive Gene Dysregulation Patterns

BACKGROUND: Determine global gene dysregulation affecting 4q-linked (FSHD-1) and non 4q-linked (FSHD-2) cells during early stages of myogenic differentiation. This approach has been never applied to FSHD pathogenesis. METHODOLOGY/PRINCIPAL FINDINGS: By in vitro differentiation of FSHD-1 and FSHD-2 myoblasts and gene chip analysis we derived that gene expression profile is altered only in FSHD-1 myoblasts and FSHD-2 myotubes. The changes seen in FSHD-1 regarded a general defect in cell cycle progression, probably due to the upregulation of myogenic markers PAX3 and MYOD1, and a deficit of factors (SUV39H1 and HMGB2) involved in D4Z4 chromatin conformation. On the other hand, FSHD-2 mytubes were characterized by a general defect in RNA metabolism, protein synthesis and degradation and, to a lesser extent, in cell cycle. Common dysregulations regarded genes involved in response to oxidative stress and in sterol biosynthetic process. Interestingly, our results also suggest that miRNAs might be implied in both FSHD-1 and FSHD-2 gene dysregulation. Finally, in both cell differentiation systems, we did not observe a gradient of altered gene expression throughout the 4q35 chromosome. CONCLUSIONS/SIGNIFICANCE: FSHD-1 and FSHD-2 cells showed, in different steps of myogenic differentiation, a global deregulation of gene expression rather than an alteration of expression of 4q35 specific genes. In general, FSHD-1 and FSHD-2 global gene deregulation interested common and distinctive biological processes. In this regard, defects of cell cycle progression (FSHD-1 and to a lesser extent FSHD-2), protein synthesis and degradation (FSHD-2), response to oxidative stress (FSHD-1 and FSHD-2), and cholesterol homeostasis (FSHD-1 and FSHD-2) may in general impair a correct myogenesis. Taken together our results recapitulate previously reported defects of FSHD-1, and add new insights into the gene deregulation characterizing both FSHD-1 and FSHD-2, in which miRNAs may play a role

Balancing thromboembolic and bleeding risk with non-vitamin K antagonist oral anticoagulants (NOACs):A systematic review and meta-analysis on gender differences

Sex and gender differences have been reported in atrial fibrillation (AF), especially in relation to differences in thromboembolic and bleeding risks. More recently, pharmacological treatments have changed following the introduction of non-vitamin K antagonist oral anticoagulants (NOACs) progressively replacing vitamin K antagonists (VKAs). The aims of this systematic review are to summarize the available evidence on NOACs and the relationship to major adverse outcomes according to sex. Moreover, we performed a meta-analysis of data from the phase III clinical trials investigating the sex effect on stroke/systemic embolic events (SEE) and major bleeding. Our literature review found small differences in NOACs efficacy and safety between male and female patients, even if so far available literature is limited to post-hoc ancillary analyses from randomized trials and one cohort study. Meta-analysis from NOAC trials found a differential effect of NOACs, with male patients being more protected from stroke/SEE and female patients more protected from major bleeding events. Further data are needed to fully elucidate sex differences in AF patients treated with NOACs

ANALISYS OF GENE EXPRESSION PROFILE DURING MYOGENESIS EVIDENCES DIFFERENT MOLECULAR DEFECTS AT THE BASIS OF FSHD-1 AND FSHD-2 PATHOGENESIS

Germ line cell-derived pluripotent stem cells (GPSCs) are derived from spermatogonial stem cells and are similar to embryonic stem (ES) cells in that they can proliferate intensively and differentiate into a variety of cell types. Previous studies have revealed some inherent differences in gene expression between undifferentiated mouse ES cells and GPSCs. Our aims were to generate functional hepatocytes from mouse GPSCs in vitro and to investigate whether the differences in gene expression may impact on the hepatocyte differentiation capacity of the GPSCs compared with ES cells. Mouse GPSCs and ES cells were induced to differentiate into hepatocytes through embryoid body formation, with very high efficiency. These hepatocytes were characterized at cellular, molecular, and functional levels. The GPSCderived hepatocytes expressed hepatic markers and were metabolically active as shown by albumin and haptoglobin secretion, urea synthesis, glycogen storage, and indocyanine green uptake. We also performed an unprecedented DNA microarray analysis comparing different stages of hepatocyte differentiation. Gene expression profiling demonstrated a strong similarity between GPSC and ES cells at different stages of induced hepatic differentiation. Moreover, Pearson correlation analysis of the microarray datasets suggested that, at late hepatic differentiation stages, the in vitro-derived cells were closer to fetal mouse primary hepatocytes than to those obtained from neonates. We have shown for the first time that adult GPSCs can be induced to differentiate into functional hepatocytes in vitro. Moreover, our ongoing in vivo work shows that GPSC-derived hepatocytes can colonize the liver of monocrotaline-treated, partially hepatectomised mice. These GPSC-derived hepatocytes thus offer great potential for cell replacement therapy for a wide variety of liver diseases

Admission neutrophil-to-lymphocyte ratio predicts length of hospitalization and need for ICU admission in adults with Status Epilepticus

Background and objectives: Status epilepticus (SE) is a time-dependent neurological emergency. The current study evaluated the prognostic value of admission neutrophil-to-lymphocyte ratio (NLR) in patients with status epilepticus. Methods: In this retrospective observational cohort study we included all consecutive patients discharged from our neurology unit with the clinical or EEG diagnosis of SE from 2012 to 2022. Stepwise multivariate analysis was conducted to test the association of NLR with length of hospitalization, need for Intensive Care Unit (ICU) admission and 30 days mortality. Receiver operating characteristic (ROC) analysis was performed to identify the best cutoff for NLR to identify patients who will need ICU admission. Results: A total of 116 patients were enrolled in our study. NLR was correlated with length of hospitalization (p = 0.020) and need for ICU admission ( p = 0.046). In addition, the risk of ICU admission increased in patients with intracranial hemorrhage and length of hospitalization was correlated with C-reactive protein-to-albumin ratio (CRP/ALB). ROC analysis identified a NLR of 3.6 as best cutoff value to discriminate need of ICU admission (area under the curve [AUC]=0.678; p = 0.011; Youden's index=0.358; sensitivity, 90.5%, specificity, 45.3%). Discussion: In patients with SE admission NLR could be a predictor of length of hospitalization and need for ICU admission

Clinical and genetic determinants of nevirapine plasma trough concentration

Background: Only few data are available on the influence of CYP2B6 and CYP3A4/A5 polymorphisms on nevirapine plasma concentrations in the Caucasian population. Our aim was to assess the impact of CYP2B6 and CYP3A4/A5 polymorphisms on nevirapine plasma concentrations consecutively collected. Methods: We retrospectively analyzed clinical data of all HIV-positive patients who were followed at the Infectious Diseases Unit, DIBIC Luigi Sacco, University of Milan between January 2000 and December 2015. All patients with at least one nevirapine plasma trough concentration (NVP C min ) determination were tested for CYP2B6 c.516 G>T, CYP3A4*22C>T and CYP3A5*3 A>G polymorphisms. Univariate and multivariate regression analyses were carried out considering NVP C min as the dependent variable and genetic polymorphisms and clinical characteristics as independent variables. Results: A total of 143 patients were evaluated. Most of them were males (61.5%) and Caucasian (92.3%). Overall, NVP C min varied from 1571 to 14,189  ng/mL (median  =  5063  ng/mL, interquartile range  =  3915–6854). The median NVP C min significantly differed in patients with different CYP2B6 genotypes, but did not vary in those with different CYP3A phenotypes. In the final general linear model, factors significantly associated with a higher NVP C min were each extra unit of T alleles of CYP2B6 rs3745274 (β  =  0.328, 95% confidence interval  =  0.172–0.484; p   <  0.0001), older age (β  =  0.362, 95% confidence interval  =  0.193–0.532; p   <  0.0001) and hepatitis C virus coinfection (β  =  0.161, 95% confidence interval  =  0.006–0.315; p   <  0.041). Conclusion: Our study, conducted in a prevalent Caucasian population, highlighted the importance of CYP2B6 genetic variants in influencing nevirapine plasma trough concentration. Furthermore, older age and hepatitis C virus coinfection significantly increase exposure to nevirapine

Persistent chemosensory dysfunction in a young patient with mild COVID-19 with partial recovery 15 months after the onset

Objective: It is reported that recovery from COVID-19 chemosensory deficit generally occurs in a few weeks, although olfactory dysfunction may persist longer. Here, we provide a detailed follow-up clinical investigation in a very young female patient (17-year-old) with a long-lasting anosmia after a mild infection, with partial recovery 15 months after the onset. Methods: Neuroimaging and neurophysiologic assessments as well as olfactory mucosa swabbing for microbiological and immunocytochemical analyses were performed. Olfactory and gustatory evaluations were conducted through validated tests. Results: Chemosensory evaluations were consistent with anosmia associated with parosmia phenomena and gustatory impairment, the latter less persistent. Brain MRI (3.0 T) showed no microvascular injury in olfactory bulbs and brain albeit we cannot rule out slight structural abnormalities during the acute phase, and a high-density EEG was negative. Immunocytochemistry of olfactory mucosa swabs showed high expression of ACE2 in sustentacular cells and lower dot-like cytoplasmic positivity in neuronal-shaped cells. Discussion: The occurrence of long-term persistent olfactory deficit in spite of the absence of structural brain and olfactory bulb involvement supports the view of a possible persistent dysfunction of both sustentacular cells and olfactory neurons. The gustatory dysfunction even if less persisting for the described features could be related to a primary gustatory system involvement. Future longitudinal studies are needed to investigate the persistence of chemosensory impairment, which could have a relevant impact on the daily life