The lack of the Celf2a splicing factor converts a Duchenne genotype into a Becker phenotype

Substitutions, deletions and duplications in the dystrophin gene lead to either the severe Duchenne muscular dystrophy (DMD) or mild Becker muscular dystrophy depending on whether out-of-frame or in-frame transcripts are produced. We identified a DMD case (GSΔ44) where the correlation between genotype and phenotype is not respected, even if carrying a typical Duchenne mutation (exon 44 deletion) a Becker-like phenotype was observed. Here we report that in this patient, partial restoration of an in-frame transcript occurs by natural skipping of exon 45 and that this is due to the lack of Celf2a, a splicing factor that interacts with exon 45 in the dystrophin pre-mRNA. Several experiments are presented that demonstrate the central role of Celf2a in controlling exon 45 splicing; our data point to this factor as a potential target for the improvement of those DMD therapeutic treatments, which requires exon 45 skipping

Differential expression of cyclooxygenases in hypertrophic scar and keloid tissues

Hypertrophic scar (HS) and keloid (KL) are two forms of an abnormal cutaneous scarring process, mainly characterized by excessive extracellular matrix deposition and fibroblast proliferation. Despite the increased understanding of the molecular and cellular events leading to HS and KL, the pathogenesis of these lesions remains poorly understood. A pivotal role in the formation of abnormal scars has been ascribed to transforming growth factor-β, whose activity appears to be mediated through a link with pathways acting via cyclooxygenases (COX-1 and COX-2). To date, there is no report on the in vivo expression of COX-1 and COX-2 in human HS and KL tissues. Therefore, using immunohistochemistry and Western blot analysis, we investigated 36 cases of KL, 32 cases of HS, and 25 cases of normal skin in order to define the localization and distribution of COX-1 and COX-2 in the tissues of these scar lesions and the overlying epidermis. The results mainly show the following: (a) a significant overexpression of COX-1 in HS tissues and the overlying epidermis as compared with normal skin and KL tissues and (b) a significant overexpression of COX-2 in KL tissue and the overlying epidermis in contrast to normal skin and HS tissues. Our data support the hypothesis that both COXs are involved in the pathogenesis of scar lesions in different ways and, particularly, COX-1 in the formation of HS and COX-2 in the formation of KL. In addition, the overexpression of COX-1 and COX-2 in the epidermis overlying HS and KL tissues, respectively, underlines the importance of epithelial- mesenchymal interactions in the pathogenesis of scar lesion

Use of routine ureteral stents in cesarean hysterectomy for placenta accreta

OBJECTIVE: To evaluate benefits of use of ureteral stents in association with cesarean hysterectomy in case of placenta accreta. METHODS: This was a single center, cohort study. Clinical records of singleton pregnancies with placenta accreta who underwent cesarean hysterectomy were included in the study. For this study, pregnancies with diagnoses of placenta accreta, increta, or percreta were considered under the umbrella term of placenta accreta. For all women with placenta accreta, delivery was planned via cesarean hysterectomy at 340-356 weeks, without any attempt to remove the placenta. Reasons for earlier delivery included vaginal bleeding and spontaneous onset of labor. The primary outcome was the incidence of unintentional urinary tract injury. Outcomes were compared in a cohort of women who had planned the placement of ureteral stents and in those who did not. RESULTS: Forty-four singleton gestations with confirmed placenta accreta at the time of cesarean hysterectomy were included in the study. Twenty-four (54.5%) of the included women had the placing of ureteral stents prior to cesarean, while 20 (45.5%) did not. At histological confirmation, most of them had placenta accreta (17/44, 38.6%), 14 placenta increta (31.8%), and 13 placenta percreta (29.6%). Urinary tract injuries occurred in eight cases (18.2%), six in the ureteral stents and two in the non-ureteral stents group (25 versus 10%; p = .21). All the injuries were bladder injuries, while no cases of ureteral injury were recorded. All injuries were recognized intraoperatively. CONCLUSION: In case of placenta accreta, the use of ureteral stents in association with cesarean hysterectomy does not reduce the risk of urinary tract injury

Drug resistance in Medulloblastoma is driven by YB-1, ABCB1 and a seven-gene drug signature

Therapy resistance represents an unmet challenge in the treatment of medulloblastoma. Accordingly, the identification of targets that mark drug-resistant cell populations, or drive the proliferation of resistant cells, may improve treatment strategies. To address this, we undertook a targeted approach focused on the multi-functional transcription factor YB-1. Genetic knockdown of YB-1 in Group 3 medulloblastoma cell lines diminished cell invasion in 3D in vitro assays and increased sensitivity to standard-of-care chemotherapeutic vincristine and anti-cancer agents panobinostat and JQ1. For vincristine, this occurred in part by YB-1-mediated transcriptional regulation of multi-drug resistance gene ABCB1, as determined by chromatin immunoprecipitation. Whole transcriptome sequencing of YB-1 knockdown cells identified a role for YB-1 in the regulation of tumourigenic processes, including lipid metabolism, cell death and survival and MYC and mTOR pathways. Stable cisplatin- and vincristine-tolerant Group 3 and SHH cell lines were generated to identify additional mechanisms driving resistance to standard-of-care medulloblastoma therapy. Next-generation sequencing revealed a vastly different transcriptomic landscape following chronic drug exposure, including a drug-tolerant seven-gene expression signature, common to all sequenced drug-tolerant cell lines, representing therapeutically targetable genes implicated in the acquisition of drug tolerance. Our findings provide significant insight into mechanisms and genes underlying therapy resistance in medulloblastoma

Maternal and neonatal outcomes in planned versus emergency cesarean delivery for placenta accreta spectrum: A multinational database study

Introduction: Placenta accreta spectrum (PAS) is a condition often resulting in severe maternal morbidity. Scheduled delivery by an experienced team has been shown to improve maternal outcomes; however, the benefits must be weighed against the risk of iatrogenic prematurity. The aim of this study is to investigate the rates of emergency delivery seen for antenatally suspected PAS and compare the resulting outcomes in the 15 referral centers of the International Society for PAS (IS-PAS). Material and methods: Fifteen centers provided cases between 2008 and 2019. The women included were divided into two groups according to whether they had a planned or an emergency cesarean delivery. Delivery was defined as "planned" when performed at a time and date to suit the team. All the remaining cases were classified as "emergency". Maternal characteristics and neonatal outcomes were compared between the two groups according to gestation at delivery. Results: In all, 356 women were included. Of these, 239 (67%) underwent a planned delivery and 117 (33%) an emergency delivery. Vaginal bleeding was the indication for emergency delivery in 41 of the 117 women (41%). There were no significant differences in terms of blood loss, transfusion rates or major maternal morbidity between planned and emergency deliveries. However, the rate of maternal intensive therapy unit admission was increased with emergency delivery (45% vs 33%, P = .02). Antepartum hemorrhage was the only independent predictor of emergency delivery (aOR: 4.3, 95% confidence interval 2.4-7.7). Emergency delivery due to vaginal bleeding was more frequent with false-positive cases (antenatally suspected but not confirmed as PAS at delivery) and the milder grades of PAS (accreta/increta). The rate of infants experiencing any major neonatal morbidity was 25% at 34+1 to 36+0 weeks and 19% at >36+0 weeks. Conclusions: Emergency delivery in centers of excellence did not increase blood loss, transfusion rates or maternal morbidity. The single greatest risk factor for emergency delivery was antenatal hemorrhage. When adequate expertise and resources are available, to defer delivery in women with no significant antenatal bleeding and no risk factors for pre-term birth until >36+0 weeks can be considered to improve fetal outcomes. Further studies are needed to investigate this fully

Cross-Mapping Events in miRNAs Reveal Potential miRNA-Mimics and Evolutionary Implications

MicroRNAs (miRNAs) have important roles in various biological processes. miRNA cross-mapping is a prevalent phenomenon where miRNA sequence originating from one genomic region is mapped to another location. To have a better understanding of this phenomenon in the human genome, we performed a detailed analysis in this paper using public miRNA high-throughput sequencing data and all known human miRNAs. We observed widespread cross-mapping events between miRNA precursors (pre-miRNAs), other non-coding RNAs (ncRNAs) and the opposite strands of pre-miRNAs by analyzing the high-throughput sequencing data. Computational analysis on all known human miRNAs also confirmed that many of them could be involved in cross-mapping events. The processing or decay of both ncRNAs and pre-miRNA opposite strand transcripts may contribute to miRNA enrichment, although some might be miRNA-mimics due to miRNA mis-annotation. Comparing to canonical miRNAs, miRNAs involved in cross-mapping events between pre-miRNAs and other ncRNAs normally had shorter lengths (17–19 nt), lower prediction scores and were classified as pseudo miRNA precursors. Notably, 4.9% of all human miRNAs could be accurately mapped to the opposite strands of pre-miRNAs, which showed that both strands of the same genomic region had the potential to produce mature miRNAs and simultaneously implied some potential miRNA precursors. We proposed that the cross-mapping events are more complex than we previously thought. Sequence similarity between other ncRNAs and pre-miRNAs and the specific stem-loop structures of pre-miRNAs may provide evolutionary implications

The P-Loop Domain of Yeast Clp1 Mediates Interactions Between CF IA and CPF Factors in Pre-mRNA 3′ End Formation

Cleavage factor IA (CF IA), cleavage and polyadenylation factor (CPF), constitute major protein complexes required for pre-mRNA 3′ end formation in yeast. The Clp1 protein associates with Pcf11, Rna15 and Rna14 in CF IA but its functional role remained unclear. Clp1 carries an evolutionarily conserved P-loop motif that was previously shown to bind ATP. Interestingly, human and archaean Clp1 homologues, but not the yeast protein, carry 5′ RNA kinase activity. We show that depletion of Clp1 in yeast promoted defective 3′ end formation and RNA polymerase II termination; however, cells expressing Clp1 with mutant P-loops displayed only minor defects in gene expression. Similarly, purified and reconstituted mutant CF IA factors that interfered with ATP binding complemented CF IA depleted extracts in coupled in vitro transcription/3′ end processing reactions. We found that Clp1 was required to assemble recombinant CF IA and that certain P-loop mutants failed to interact with the CF IA subunit Pcf11. In contrast, mutations in Clp1 enhanced binding to the 3′ endonuclease Ysh1 that is a component of CPF. Our results support a structural role for the Clp1 P-loop motif. ATP binding by Clp1 likely contributes to CF IA formation and cross-factor interactions during the dynamic process of 3′ end formation

Microprocessor mediates transcriptional termination of long noncoding RNA transcripts hosting microRNAs

MicroRNA (miRNA) play a major role in the post-transcriptional regulation of gene expression. Mammalian miRNA biogenesis begins with co-transcriptional cleavage of RNA polymerase II (Pol II) transcripts by the Microprocessor complex. While most miRNA are located within introns of protein coding genes, a substantial minority of miRNA originate from long non coding (lnc) RNA where transcript processing is largely uncharacterized. Here, by detailed characterization of liver-specific lnc-pri-miR-122 and genome-wide analysis, we show that most lnc-pri-miRNA do not use the canonical cleavage and polyadenylation (CPA) pathway but instead use Microprocessor cleavage to terminate transcription. Microprocessor inactivation leads to extensive transcriptional readthrough of lnc-pri-miRNA and transcriptional interference with downstream genes. Consequently we define a novel RNase III-mediated, polyadenylation-independent mechanism of Pol II transcription termination in mammalian cells

Can interventions that aim to decrease Lyme disease hazard at non-domestic sites be effective without negatively affecting ecosystem health? A systematic review protocol

Background Lyme disease (LD) is the most commonly reported, broadly distributed vector-borne disease of the northern temperate zone. It is transmitted by ticks and, if untreated, can cause skin, cardiac, nervous system and musculoskeletal disease. The distribution and incidence of LD is increasing across much of North America and Western Europe. Interventions to decrease exposure to LD hazard by encouraging behavioural change have low acceptance in high risk groups, and a safe, effective human LD vaccine is not presently available. As a result, habitat level interventions to decrease LD hazard itself (i.e. levels of infected ticks) have been proposed. However, some interventions may potentially negatively affect ecosystem health, and consequentially be neither desirable, nor politically feasible. This systematic review will catalogue interventions that aim to reduce LD hazard at non-domestic sites, and examine the evidence supporting those which are unlikely to negatively affect ecosystem health. Methods The review will be carried out in two steps. First, a screening and cataloguing stage will be conducted to identify and characterise interventions to decrease LD hazard at non-domestic sites. Secondly, the subset of interventions identified during cataloguing as unlikely to negatively affect ecosystem health will be investigated. In the screening and cataloguing step literature will be collected through database searching using pre-chosen search strings, hand-searching key journals and reviewing the websites of public health bodies. Further references will be identified by contacting stakeholders and researchers. Article screening and assessment of the likely effects of interventions on ecosystem health will be carried out independently by two reviewers. A third reviewer will be consulted if disagreements arise. The cataloguing step results will be presented in tables. Study quality will then be assessed independently by two reviewers, using adapted versions of established tools developed in healthcare research. These results will be presented in a narrative synthesis alongside tables. Though a full meta-analysis is not expected to be possible, if sub-groups of studies are sufficiently similar to compare, a partial meta-analysis will be carried out