Impaired regeneration in LGMD2A supported by increased Pax7 positive satellite cell content and muscle specific microRNA dysregulation

Introduction—Recent in vitro studies suggest that CAPN3 deficiency leads initially to accelerated myofiber formation followed by depletion of satellite cells (SC). In normal muscle, upregulation of miR-1 and miR-206 facilitates transition from proliferating SCs to differentiating myogenic progenitors. Methods—We examined the histopathological stages, Pax7 SC content, and muscle specific microRNA expression in biopsy specimens from well-characterized LGMD 2A patients to gain insight into disease pathogenesis. Results—Three distinct stages of pathological changes were identified that represented the continuum of the dystrophic process from prominent inflammation with necrosis and regeneration to prominent fibrosis, which correlated with age and disease duration. Pax7-positive SCs were highest in fibrotic group and correlated with down-regulation of miR-1, miR-133a, and miR-206. Conclusions—These observations, and other published reports, are consistent with microRNA dysregulation leading to inability of Pax7-positive SCs to transit from proliferation to differentiation. This results in impaired regeneration and fibrosis.This work was supported by NIH NIAMS U54 AR050733-05, Jesse’s Journey, and the muscular Dystrophy Associatio

Protocol for a mixed-methods study to develop and feasibility test a digital system for the capture of Patient-Reported Outcomes (PROs) in patients receiving Chimeric Antigen Receptor T-cell (CAR-T) therapies (The PRO-CAR-T Study)

Introduction: Chimeric antigen receptor (CAR) T-cell therapies are novel, potentially curative therapies for haematological malignancies. CAR T-cell therapies are associated with severe toxicities, meaning patients require monitoring during acute and postacute treatment phases. Electronic patient-reported outcomes (ePROs), self-reports of health status provided via online questionnaires, can complement clinician observation with potential to improve patient outcomes. This study will develop and evaluate feasibility of a new ePRO system for CAR-T patients in routine care. Methods and analysis: Multiphase, mixed-methods study involving multiple stakeholder groups (patients, family members, carers, clinicians, academics/researchers and policy-makers). The intervention development phase comprises a Delphi study to select PRO measures for the digital system, a codesign workshop and consensus meetings to establish thresholds for notifications to the clinical team if a patient reports severe symptoms or side effects. Usability testing will evaluate how users interact with the digital system and, lastly, we will evaluate ePRO system feasibility with 30 CAR-T patients (adults aged 18+ years) when used in addition to usual care. Feasibility study participants will use the ePRO system to submit self-reports of symptoms, treatment tolerability and quality of life at specific time points. The CAR-T clinical team will respond to system notifications triggered by patients’ submitted responses with actions in line with standard clinical practice. Feasibility measures will be collected at prespecified time points following CAR T-cell infusion. A qualitative substudy involving patients and clinical team members will explore acceptability of the ePRO system. Ethics and dissemination: Favourable ethical opinion was granted by the Health and Social Care Research Ethics Committee B(HSC REC B) (ref: 23/NI/0104) on 28 September 2023. Findings will be submitted for publication in high-quality, peer-reviewed journals. Summaries of results, codeveloped with the Blood and Transplant Research Unit Patient and Public Involvement and Engagement group, will be disseminated to all interested groups. Trial registration number: ISCTRN11232653

Is exposure to formaldehyde in air causally associated with leukemia?—A hypothesis-based weight-of-evidence analysis

Recent scientific debate has focused on the potential for inhaled formaldehyde to cause lymphohematopoietic cancers, particularly leukemias, in humans. The concern stems from certain epidemiology studies reporting an association, although particulars of endpoints and dosimetry are inconsistent across studies and several other studies show no such effects. Animal studies generally report neither hematotoxicity nor leukemia associated with formaldehyde inhalation, and hematotoxicity studies in humans are inconsistent. Formaldehyde's reactivity has been thought to preclude systemic exposure following inhalation, and its apparent inability to reach and affect the target tissues attacked by known leukemogens has, heretofore, led to skepticism regarding its potential to cause human lymphohematopoietic cancers. Recently, however, potential modes of action for formaldehyde leukemogenesis have been hypothesized, and it has been suggested that formaldehyde be identified as a known human leukemogen. In this article, we apply our hypothesis-based weight-of-evidence (HBWoE) approach to evaluate the large body of evidence regarding formaldehyde and leukemogenesis, attending to how human, animal, and mode-of-action results inform one another. We trace the logic of inference within and across all studies, and articulate how one could account for the suite of available observations under the various proposed hypotheses. Upon comparison of alternative proposals regarding what causal processes may have led to the array of observations as we see them, we conclude that the case fora causal association is weak and strains biological plausibility. Instead, apparent association between formaldehyde inhalation and leukemia in some human studies is better interpreted as due to chance or confounding

The Practical Realities of Giving Back

In this thematic section, authors consider practical ways of giving back to the communities in which they conduct research. Each author discusses their evolving thoughts on how to give back in these practical ways. Some of these authors discuss giving back by giving money, food, rides, parties, and water bottles. In other cases, authors discuss giving back by creating jobs in the short or long term, grant writing, advocacy, and education. Story-telling is also a theme that many of the authors in this section discuss. For some authors, non-material forms of giving back are critical—simply maintaining social ties to the communities in which they worked, or sharing humor. The authors consider the utility of their attempts at giving back, and in some cases present their personal philosophy or guidelines on the subject

Effects of whole-tree harvesting at three forests in upland Britain

Three experiments were established in the 1990s to examine the impact of complete residue (brash) and above-ground biomass removal (i.e. ‘whole-tree harvesting’, WTH) at clearfelling on the subsequent growth and yield of replanted Sitka spruce (Picea sitchensis). The sites were of varying fertility; two would now be considered to be of ‘medium’ risk for brash removal, while one would be a ‘high’-risk site. The interactions between brash removal and regular remedial fertilizer applications and weed control regimes were also investigated at each site. After 10 years, trees had been successfully established at all sites, and in most cases, the treatments were close to canopy closure

Quality Assurance for Duchenne and Becker Muscular Dystrophy Genetic Testing: Development of a Genomic DNA Reference Material Panel

Duchenne and Becker muscular dystrophies (DMD/BMD) are allelic X-linked recessive disorders that affect approximately 1 in 3500 and 1 in 20,000 male individuals, respectively. Approximately 65% of patients with DMD have deletions, 7% to 10% have duplications, and 25% to 30% have point mutations in one or more of the 79 exons of the dystrophin gene. Most clinical genetics laboratories test for deletions, and some use technologies that can detect smaller mutations and duplications. Reference and quality control materials for DMD/BMD diagnostic and carrier genetic testing are not commercially available. To help address this need, the Centers for Disease Control and Prevention–based Genetic Testing Reference Material Coordination Program, in collaboration with members of the genetic testing and the DMD/BMD patient communities and the Coriell Cell Repositories, have characterized new and existing cell lines to create a comprehensive DMD/BMD reference material panel. Samples from 31 Coriell DMD cell lines from male probands and female carriers were analyzed using the Affymetrix SNP Array 6.0 and Multiplex Ligation-Dependent Probe Amplification (MRC-Holland BV, Amsterdam, the Netherlands), a multiplex PCR assay, and DNA sequence analysis. Identified were 16 cell lines with deletions, 9 with duplications, and 4 with point mutations distributed throughout the dystrophin gene. There were no discordant results within assay limitations. These samples are publicly available from Coriell Institute for Medical Research (Camden, NJ) and can be used for quality assurance, proficiency testing, test development, and research, and should help improve the accuracy of DMD testing

Identification of a Recurrent Microdeletion at 17q23.1q23.2 Flanked by Segmental Duplications Associated with Heart Defects and Limb Abnormalities

Segmental duplications, which comprise ∼5%–10% of the human genome, are known to mediate medically relevant deletions, duplications, and inversions through nonallelic homologous recombination (NAHR) and have been suggested to be hot spots in chromosome evolution and human genomic instability. We report seven individuals with microdeletions at 17q23.1q23.2, identified by microarray-based comparative genomic hybridization (aCGH). Six of the seven deletions are ∼2.2 Mb in size and flanked by large segmental duplications of >98% sequence identity and in the same orientation. One of the deletions is ∼2.8 Mb in size and is flanked on the distal side by a segmental duplication, whereas the proximal breakpoint falls between segmental duplications. These characteristics suggest that NAHR mediated six out of seven of these rearrangements. These individuals have common features, including mild to moderate developmental delay (particularly speech delay), microcephaly, postnatal growth retardation, heart defects, and hand, foot, and limb abnormalities. Although all individuals had at least mild dysmorphic facial features, there was no characteristic constellation of features that would elicit clinical suspicion of a specific disorder. The identification of common clinical features suggests that microdeletions at 17q23.1q23.2 constitute a novel syndrome. Furthermore, the inclusion in the minimal deletion region of TBX2 and TBX4, transcription factors belonging to a family of genes implicated in a variety of developmental pathways including those of heart and limb, suggests that these genes may play an important role in the phenotype of this emerging syndrome

Assessment of 2q23.1 Microdeletion Syndrome Implicates MBD5 as a Single Causal Locus of Intellectual Disability, Epilepsy, and Autism Spectrum Disorder

Persons with neurodevelopmental disorders or autism spectrum disorder (ASD) often harbor chromosomal microdeletions, yet the individual genetic contributors within these regions have not been systematically evaluated. We established a consortium of clinical diagnostic and research laboratories to accumulate a large cohort with genetic alterations of chromosomal region 2q23.1 and acquired 65 subjects with microdeletion or translocation. We sequenced translocation breakpoints; aligned microdeletions to determine the critical region; assessed effects on mRNA expression; and examined medical records, photos, and clinical evaluations. We identified a single gene, methyl-CpG-binding domain 5 (MBD5), as the only locus that defined the critical region. Partial or complete deletion of MBD5 was associated with haploinsufficiency of mRNA expression, intellectual disability, epilepsy, and autistic features. Fourteen alterations, including partial deletions of noncoding regions not typically captured or considered pathogenic by current diagnostic screening, disrupted MBD5 alone. Expression profiles and clinical characteristics were largely indistinguishable between MBD5-specific alteration and deletion of the entire 2q23.1 interval. No copy-number alterations of MBD5 were observed in 7878 controls, suggesting MBD5 alterations are highly penetrant. We surveyed MBD5 coding variations among 747 ASD subjects compared to 2043 non-ASD subjects analyzed by whole-exome sequencing and detected an association with a highly conserved methyl-CpG-binding domain missense variant, p.79Gly>Glu (c.236G>A) (p = 0.012). These results suggest that genetic alterations of MBD5 cause features of 2q23.1 microdeletion syndrome and that this epigenetic regulator significantly contributes to ASD risk, warranting further consideration in research and clinical diagnostic screening and highlighting the importance of chromatin remodeling in the etiology of these complex disorders