Epigenetic regulation by polycomb repressive complex 1 promotes cerebral cavernous malformations.

Cerebral cavernous malformations (CCMs) are anomalies of the cerebral vasculature. Loss of the CCM proteins CCM1/KRIT1, CCM2, or CCM3/PDCD10 trigger a MAPK-Krüppel-like factor 2 (KLF2) signaling cascade, which induces a pathophysiological pattern of gene expression. The downstream target genes that are activated by KLF2 are mostly unknown. Here we show that Chromobox Protein Homolog 7 (CBX7), component of the Polycomb Repressive Complex 1, contributes to pathophysiological KLF2 signaling during zebrafish cardiovascular development. CBX7/cbx7a mRNA is strongly upregulated in lesions of CCM patients, and in human, mouse, and zebrafish CCM-deficient endothelial cells. The silencing or pharmacological inhibition of CBX7/Cbx7a suppresses pathological CCM phenotypes in ccm2 zebrafish, CCM2-deficient HUVECs, and in a pre-clinical murine CCM3 disease model. Whole-transcriptome datasets from zebrafish cardiovascular tissues and human endothelial cells reveal a role of CBX7/Cbx7a in the activation of KLF2 target genes including TEK, ANGPT1, WNT9, and endoMT-associated genes. Our findings uncover an intricate interplay in the regulation of Klf2-dependent biomechanical signaling by CBX7 in CCM. This work also provides insights for therapeutic strategies in the pathogenesis of CCM.

Validating a composite endpoint for acceptability evaluation of oral drug formulations in the pediatric population: a randomized, open-label, single dose, cross-over study.

Objective: This study aimed to validate the newly developed composite acceptability endpoint to investigate acceptability of oral pediatric drug formulations that integrates swallowability and palatability assessments. Methods: In this open-label study acceptability of oral formulations was tested in three age groups (1-<6 months, 6-<12 years, and 12-<18 years) with a 2-way cross-over design in children aged 1-<6 months (syrup and mini-tablets), and with an incomplete block design of four sequences with three out of four formulations (syrup, mini-tablets, oblong tablet, and round tablet) each in children aged 6-<18 years. The primary endpoint was acceptability derived from the composite acceptability endpoint. Secondary endpoints were palatability and acceptability derived from swallowability. Results: A total of 320 children were stratified into three age groups (80 children aged 1-<6 months, 120 children aged 6-<12 years, and 120 children aged 12-<18 years). All participants completed the study. Age-specific differences were observed in acceptability derived from the composite acceptability endpoint. Mini-tablets had the highest acceptability in participants aged 1-<6 months and 6-<12 years while the oblong tablet was leading in adolescent participants (12-<18 years). Conclusion: This study demonstrated that the composite acceptability endpoint method integrating both swallowability and palatability assessments is a sensitive method to assess acceptability of drug formulations in children of different age. Clinical Trial Registration: https://drks.de/search/de, identifier DRKS00027948.

Dosage Forms Suitability in Pediatrics: Acceptability of Antibiotics in a German Hospital.

Although drug acceptability can have a significant impact on patient adherence in pediatric therapy, data are limited, even for common therapeutic areas. We present the second part of an acceptability study conducted at the University Children's Hospital Düsseldorf, Germany. The study investigated the acceptability of most commonly used antibiotics in a pediatric hospital setting. The researchers used the acceptability reference framework to score the acceptability of five antibiotics based on 150 real-life observer reports of medicine intake. Four antibiotics assessed in this study were formulated as preparations for injection (ampicillin, ampicillin/sulbactam, ceftriaxone, and gentamicin) and one as a powder for oral liquid suspension (co-amoxiclav). All the antibiotics formulated as preparations for injection were rated negatively due to high rates of negative reactions (80%), the use of restraint (51%), the use of extra devices (99%), and long preparation and administration times (100%). The antibiotic formulated as a powder was significantly more well accepted. The study concluded that there is a lack of appropriate formulations for antibiotics for use in children. These findings are important in improving knowledge on acceptability drivers and might help in formulating and prescribing better medicines for children. The study highlights the need for healthcare professionals to have knowledge about the acceptability of different products to select the best-adapted product for each patient.

Evaluating the Acceptability, Swallowability, and Palatability of Film-Coated Mini-Tablet Formulation in Young Children: Results from an Open-Label, Single-Dose, Cross-Over Study.

Mini-tablets are advantageous over liquid formulations in overcoming challenges related to stability, taste, and dosage. This open-label, single-dose, cross-over study investigated the acceptability and safety of drug-free, film-coated mini-tablets in children aged 1 month-6 years (stratified: 4-6 years, 2-<4 years, 1-<2 years, 6-<12 months, and 1-<6 months), and their preference for swallowing either a high quantity of 2.0 mm or a low quantity of 2.5 mm diameter mini-tablets. The primary endpoint was acceptability derived from swallowability. The secondary endpoints were investigator-observed palatability, acceptability as a composite endpoint derived from both swallowability and palatability, and safety. Of 320 children randomized, 319 completed the study. Across all tablet sizes, quantities and age groups, acceptability rates based on swallowability were high (at least 87%). Palatability was rated as "pleasant/neutral" in 96.6% of children. The acceptability rates as per the composite endpoint were at least 77% and 86% for the 2.0 mm and 2.5 mm film-coated mini-tablets, respectively. No adverse events or deaths were reported. Recruitment in the 1-<6-months group was stopped early due to coughing-evaluated as "choked on" in three children. Both 2.0 mm and 2.5 mm film-coated mini-tablets are suitable formulations for young children.

Neuroimaging in Primary Coenzyme-Q10-Deficiency Disorders.

Coenzyme Q10 (CoQ10) is an endogenously synthesized lipid molecule. It is best known for its role as a cofactor within the mitochondrial respiratory chain where it functions in electron transfer and ATP synthesis. However, there are many other cellular pathways that also depend on the CoQ10 supply (redox homeostasis, ferroptosis and sulfide oxidation). The CoQ10 biosynthesis pathway consists of several enzymes, which are encoded by the nuclear DNA. The majority of these enzymes are responsible for modifications of the CoQ-head group (benzoquinone ring). Only three enzymes (PDSS1, PDSS2 and COQ2) are required for assembly and attachment of the polyisoprenoid side chain. The head-modifying enzymes may assemble into resolvable domains, representing COQ complexes. During the last two decades, numerous inborn errors in CoQ10 biosynthesis enzymes have been identified. Thus far, 11 disease genes are known (PDSS1, PDSS2, COQ2, COQ4, COQ5, COQ6, COQ7, COQ8A, COQ8B, COQ9 and HPDL). Disease onset is highly variable and ranges from the neonatal period to late adulthood. CoQ10 deficiency exerts detrimental effects on the nervous system. Potential consequences are neuronal death, neuroinflammation and cerebral gliosis. Clinical features include encephalopathy, regression, movement disorders, epilepsy and intellectual disability. Brain magnetic resonance imaging (MRI) is the most important tool for diagnostic evaluation of neurological damage in individuals with CoQ10 deficiency. However, due to the rarity of the different gene defects, information on disease manifestations within the central nervous system is scarce. This review aims to provide an overview of brain MRI patterns observed in primary CoQ10 biosynthesis disorders and to highlight disease-specific findings.

Acceptability, Swallowability, Palatability, and Safety of Multiple Film-Coated Mini-Tablets in Children Aged ≥2-<7 Years: Results of an Open-Label Randomised Study.

This single-centre, open-label, randomised, parallel-group study assessed the acceptability, swallowability, palatability, and safety of film-coated, 3 mm diameter mini-tablets in children aged ≥2-<7 years. In total, 300 participants were randomised (2:2:1:1) to receive a single oral administration of 16 (group A) or 32 (group B) mini-tablets with soft food or 16 (group C) or 32 (group D) mini-tablets with water. Children in each group were stratified by age group (2-<3 years; 3-<4 years; 4-<5 years; 5-<6 years; and 6-<7 years). Groups C and D were pooled for statistical analyses. The rates of acceptability (swallowed ≥80% of the mini-tablets with or without chewing), swallowability (swallowed all mini-tablets without chewing or any leftover), and palatability (positive/neutral responses) were ≥80.0%, ≥42.0%, and ≥82.0%, respectively, across the study groups. No marked differences were observed between groups or across age groups. No adverse events or issues of clinical relevance with deglutition were reported. Mini-tablets taken with soft food or water provide a suitable method for administering medicines to children aged ≥2-<7 years. This study was registered in the German Clinical Trial Register (No. DRKS00024617).

Dosage Forms Suitability in Pediatrics: Acceptability of Analgesics and Antipyretics in a German Hospital.

Although medicine acceptability is likely to have a significant impact on the patient's adherence in pediatrics and therefore on therapy success, there is still little data even for common therapeutic areas. For analgesics/antipyretics, healthcare professionals face a wide variety of products and need knowledge to select the best adapted product for each patient. We investigated acceptability of those products most used at the University Children's Hospital Düsseldorf, Germany. Based on 180 real-life observer reports of medicine intake, we used the acceptability reference framework to score acceptability of six distinct medicines. Both ibuprofen and paracetamol tablets, mainly used in adolescents, were positively accepted. This was not the case for the solution for injection of metamizole sodium. Regarding syrups, mainly used in children under 6 years of age, ibuprofen flavored with strawberry and provided with an oral syringe was positively accepted, while paracetamol flavored with orange and provided with a measuring cup was not. Suppository appeared to be an alternative to oral liquids in infants and toddlers with palatability and administration issues. Differences appeared to be driven by dosage forms and formulations. These findings improve knowledge on acceptability drivers and might help formulating and prescribing better medicines for children.

Exploring Acceptability Drivers of Oral Antibiotics in Children: Findings from an International Observational Study.

Antibiotics are among the most commonly prescribed drugs in children. Adherence to the treatment with these drugs is of the utmost importance to prevent the emergence of resistant bacteria, a global health threat. In children, medicine acceptability is likely to have a significant impact on compliance. Herein we used a multivariate approach, considering simultaneously the many aspects of acceptability to explore the drivers of oral antibiotic acceptability in children under twelve, especially in toddlers and in preschoolers. Based on 628 real-life observer reports of the intake of 133 distinct medicines, the acceptability reference framework highlighted the influence of many factors such as age and sex of patients, previous exposure to treatment, place of administration, administration device, flavor agent in excipients and active pharmaceutical ingredient. These findings from an international observational study emphasize the multidimensional nature of acceptability. Therefore, it is crucial to consider all these different aspects for assessing this multi-faceted concept and designing or prescribing a medicine in order to reach adequate acceptability in the target population.

Pooled RT-qPCR testing for SARS-CoV-2 surveillance in schools - a cluster randomised trial.

BACKGROUND: The extent to which children and adolescents contribute to SARS-CoV-2 transmission remains not fully understood. Novel high-capacity testing methods may provide real-time epidemiological data in educational settings helping to establish a rational approach to prevent and minimize SARS-CoV-2 transmission. We investigated whether pooling of samples for SARS-CoV-2 detection by RT-qPCR is a sensitive and feasible high-capacity diagnostic strategy for surveillance of SARS-CoV-2 infections in schools. METHODS: In this study, students and school staff of 14 educational facilities in Germany were tested sequentially between November 9 and December 23, 2020, two or three times per week for at least three consecutive weeks. Participants were randomized for evaluation of two different age adjusted swab sampling methods (oropharyngeal swabs or buccal swabs compared to saliva swabs using a 'lolli method'). Swabs were collected and pooled for SARS-CoV-2 RT-qPCR. Individuals of positive pooled tests were retested by RT-qPCR the same or the following day. Positive individuals were quarantined while the SARS-CoV-2 negative individuals remained in class with continued pooled RT-qPCR surveillance. The study is registered with the German Clinical Trials register (registration number: DRKS00023911). FINDINGS: 5,537 individuals were eligible and 3970 participants were enroled and included in the analysis. In students, a total of 21,978 swabs were taken and combined in 2218 pooled RT-qPCR tests. We detected 41 positive pooled tests (1·8%) leading to 36 SARS-CoV-2 cases among students which could be identified by individual re-testing. The cumulative 3-week incidence for primary schools was 564/100,000 (6/1064, additionally 1 infection detected in week 4) and 1249/100,000 (29/2322) for secondary schools. In secondary schools, there was no difference in the number of SARS-CoV-2 positive students identified from pooled oropharyngeal swabs compared to those identified from pooled saliva samples (lolli method) (14 vs. 15 cases; 1·3% vs. 1·3%; OR 1.1; 95%-CI 0·5-2·5). A single secondary school accounted for 17 of 36 cases (47%) indicating a high burden of asymptomatic prevalent SARS-CoV-2 cases in the respective school and community. INTERPRETATION: In educational settings, SARS-CoV-2 screening by RT-qPCR-based pooled testing with easily obtainable saliva samples is a feasible method to detect incident cases and observe transmission dynamics. FUNDING: Federal Ministry of education and research (BMBF; Project B-FAST in "NaFoUniMedCovid19"; registration number: 01KX2021).

Acceptability of small-sized oblong tablets in comparison to syrup and mini-tablets in infants and toddlers: A randomized controlled trial.

OBJECTIVE: There is limited evidence for the acceptability of various drug formulations holding the potential to improve medicines administration to children. Suitable formulations need to meet the requirements of pediatric patients. Previous studies have demonstrated the acceptance of mini-tablets. Oblong tablets may carry more active ingredient content per unit than mini-tablets and could be an important alternative when the drug substance requires administration of higher doses. The primary objective was to demonstrate non-inferiority of acceptability of oblong tablets in comparison to 3 ml glucose syrup in children aged 1 to 5 years. Secondary objectives were investigation of acceptability, swallowability and palatability of mini-tablets, oblong tablets and glucose syrup in children between 1 and 5 years. METHODS: An open, randomized, single dose two-way cross-over design in two parallel study arms was applied. 280 children were stratified to one of five age groups and randomized to receiving one oblong tablet (2.5 × 6 mm) in comparison either to 3 ml glucose syrup or to three mini-tablets (2 × 2 mm). Acceptability and swallowability were assessed according to pre-defined evaluation criteria. The application of the formulations was video documented to evaluate the palatability. RESULTS: As primary objective, non-inferiority was observed regarding acceptability of the oblong tablet compared to syrup in all age groups (84.4% vs 80.1%, difference 4,29% points with 95% CI of -3.00%,11.57%). For swallowability, superiority of the oblong tablet compared to syrup could be shown (74.5% vs. 53.2%, difference 21.26% points, 95% CI of 11.29%, 31.23%). Regarding palatability, <10% of children demonstrated unpleasant reaction after intake of the oblong tablet or mini-tablets as graded by both raters, however, in contrast up to 40% of children after intake of syrup. CONCLUSION: Oblong tablets are a promising, safe alternative to liquid drug formulations and administration of multiple mini-tablets in children.

Sensing and Responding of Cardiomyocytes to Changes of Tissue Stiffness in the Diseased Heart.

Cardiomyocytes are permanently exposed to mechanical stimulation due to cardiac contractility. Passive myocardial stiffness is a crucial factor, which defines the physiological ventricular compliance and volume of diastolic filling with blood. Heart diseases often present with increased myocardial stiffness, for instance when fibrotic changes modify the composition of the cardiac extracellular matrix (ECM). Consequently, the ventricle loses its compliance, and the diastolic blood volume is reduced. Recent advances in the field of cardiac mechanobiology revealed that disease-related environmental stiffness changes cause severe alterations in cardiomyocyte cellular behavior and function. Here, we review the molecular mechanotransduction pathways that enable cardiomyocytes to sense stiffness changes and translate those into an altered gene expression. We will also summarize current knowledge about when myocardial stiffness increases in the diseased heart. Sophisticated in vitro studies revealed functional changes, when cardiomyocytes faced a stiffer matrix. Finally, we will highlight recent studies that described modulations of cardiac stiffness and thus myocardial performance in vivo. Mechanobiology research is just at the cusp of systematic investigations related to mechanical changes in the diseased heart but what is known already makes way for new therapeutic approaches in regenerative biology.

Notch and Bmp signaling pathways act coordinately during the formation of the proepicardium.

BACKGROUND: The epicardium is the outer mesothelial layer of the heart. It encloses the myocardium and plays key roles in heart development and regeneration. It derives from the proepicardium (PE), cell clusters that appear in the dorsal pericardium (DP) close to the atrioventricular canal and the venous pole of the heart, and are released into the pericardial cavity. PE cells are advected around the beating heart until they attach to the myocardium. Bmp and Notch signaling influence PE formation, but it is unclear how both signaling pathways interact during this process in the zebrafish. RESULTS: Here, we show that the developing PE is influenced by Notch signaling derived from the endothelium. Overexpression of the intracellular receptor of notch in the endothelium enhances bmp expression, increases the number of pSmad1/5 positive cells in the DP and PE, and enhances PE formation. On the contrary, pharmacological inhibition of Notch1 impairs PE formation. bmp2b overexpression can rescue loss of PE formation in the presence of a Notch1 inhibitor, but Notch gain-of-function could not recover PE formation in the absence of Bmp signaling. CONCLUSIONS: Endothelial Notch signaling activates bmp expression in the heart tube, which in turn induces PE cluster formation from the DP layer.

Actin dynamics and the Bmp pathway drive apical extrusion of proepicardial cells.

The epicardium, the outer mesothelial layer enclosing the myocardium, plays key roles in heart development and regeneration. During embryogenesis, the epicardium arises from the proepicardium (PE), a cell cluster that appears in the dorsal pericardium (DP) close to the venous pole of the heart. Little is known about how the PE emerges from the pericardial mesothelium. Using a zebrafish model and a combination of genetic tools, pharmacological agents and quantitative in vivo imaging, we reveal that a coordinated collective movement of DP cells drives PE formation. We found that Bmp signaling and the actomyosin cytoskeleton promote constriction of the DP, which enables PE cells to extrude apically. We provide evidence that cell extrusion, which has been described in the elimination of unfit cells from epithelia and the emergence of hematopoietic stem cells, is also a mechanism for PE cells to exit an organized mesothelium and fulfil their developmental fate to form a new tissue layer, the epicardium.

Notch and interacting signalling pathways in cardiac development, disease, and regeneration.

Cardiogenesis is a complex developmental process involving multiple overlapping stages of cell fate specification, proliferation, differentiation, and morphogenesis. Precise spatiotemporal coordination between the different cardiogenic processes is ensured by intercellular signalling crosstalk and tissue-tissue interactions. Notch is an intercellular signalling pathway crucial for cell fate decisions during multicellular organismal development and is aptly positioned to coordinate the complex signalling crosstalk required for progressive cell lineage restriction during cardiogenesis. In this Review, we describe the role of Notch signalling and the crosstalk with other signalling pathways during the differentiation and patterning of the different cardiac tissues and in cardiac valve and ventricular chamber development. We examine how perturbation of Notch signalling activity is linked to congenital heart diseases affecting the neonate and adult, and discuss studies that shed light on the role of Notch signalling in heart regeneration and repair after injury.

Notch signalling restricts inflammation and serpine1 expression in the dynamic endocardium of the regenerating zebrafish heart.

The zebrafish heart regenerates after ventricular damage through a process involving inflammation, fibrotic tissue deposition/removal and myocardial regeneration. Using 3D whole-mount imaging, we reveal a highly dynamic endocardium during cardiac regeneration, including changes in cell morphology, behaviour and gene expression. These events lay the foundation for an initial expansion of the endocardium that matures to form a coherent endocardial structure within the injury site. We studied two important endocardial molecules, Serpine1 and Notch, which are implicated in different aspects of endocardial regeneration. Notch signalling regulates developmental gene expression and features of endocardial maturation. Also, Notch manipulation interferes with attenuation of the inflammatory response and cardiomyocyte proliferation and dedifferentiation. serpine1 is strongly expressed very early in the wound endocardium, with decreasing expression at later time points. serpine1 expression persists in Notch-abrogated hearts, via what appears to be a conserved mechanism. Functional inhibition studies show that Serpine1 controls endocardial maturation and proliferation and cardiomyocyte proliferation. Thus, we describe a highly dynamic endocardium in the regenerating zebrafish heart, with two key endocardial players, Serpine1 and Notch signalling, regulating crucial regenerative processes.

Notch regulates blastema proliferation and prevents differentiation during adult zebrafish fin regeneration.

Zebrafish have the capacity to regenerate several organs, including the heart and fins. Fin regeneration is epimorphic, involving the formation at the amputation plane of a mass of undifferentiated, proliferating mesenchymal progenitor-like cells, called blastema. This tissue provides all the cell types that form the fin, so that after damage or amputation the fin pattern and structure are fully restored. How blastema cells remain in this progenitor-like state is poorly understood. Here, we show that the Notch pathway plays an essential role during fin regeneration. Notch signalling is activated during blastema formation and remains active throughout the regeneration process. Chemical inhibition or morpholino-mediated knockdown of Notch signalling impairs fin regeneration via decreased proliferation accompanied by reduced expression of Notch target genes in the blastema. Conversely, overexpression of a constitutively active form of the Notch1 receptor (N1ICD) in the regenerating fin leads to increased proliferation and to the expansion of the blastema cell markers msxe and msxb, as well as increased expression of the proliferation regulator aldh1a2. This blastema expansion prevents regenerative fin outgrowth, as indicated by the reduction in differentiating osteoblasts and the inhibition of bone regeneration. We conclude that Notch signalling maintains blastema cells in a plastic, undifferentiated and proliferative state, an essential requirement for fin regeneration.