DUX4-induced HSATII RNA accumulation drives protein aggregation impacting RNA processing pathways.

Unlabelled: RNA-driven protein aggregation leads to cellular dysregulation by sequestering regulatory proteins, disrupting normal cellular processes, and contributing to the development of diseases and tumorigenesis. Here, we show that double homeobox 4 (DUX4), an early embryonic transcription factor and causative gene of facioscapulohumeral muscular dystrophy (FSHD), induces the accumulation of stable intranuclear RNAs, including nucleolar-associated RNA and human satellite II (HSATII) repeat RNA. Stable intranuclear RNAs drive protein aggregation in DUX4-expressing muscle cells.

E-box independent chromatin recruitment turns MYOD into a transcriptional repressor.

MYOD is an E-box sequence-specific basic Helix-Loop-Helix (bHLH) transcriptional activator that, when expressed in non-muscle cells, induces nuclear reprogramming toward skeletal myogenesis by promoting chromatin accessibility at previously silent loci. Here, we report on the identification of a previously unrecognized property of MYOD as repressor of gene expression, via E-box-independent chromatin binding within accessible genomic elements, which invariably leads to reduced chromatin accessibility. MYOD-mediated repression requires the integrity of functional domains previously implicated in MYOD-mediated activation of gene expression.

Suspended Tissue Open Microfluidic Patterning (STOMP).

Cell-laden hydrogel constructs suspended between pillars are powerful tools for modeling tissue structure and physiology, though current fabrication techniques often limit them to uniform compositions. In contrast, tissues are complex in nature with spatial arrangements of cell types and extracellular matrices. Thus, we present Suspended Tissue Open Microfluidic Patterning (STOMP), which utilizes a removable, open microfluidic patterning channel to pattern multiple spatial regions across a single suspended tissue.

Levels of Telehealth Use, Perceived Usefulness, and Ease of Use in Behavioral Healthcare Organizations After the COVID-19 Pandemic.

The use of telehealth in behavioral healthcare increased significantly since the start of the COVID-19 pandemic and remains high even as a return to in-person care is now feasible. The use of telehealth is a promising strategy to increase access to behavioral healthcare for underserved and all populations. Identifying opportunities to improve the provision of telehealth is vital to ensuring access.

Facioscapulohumeral Dystrophy: Molecular Basis and Therapeutic Opportunities.

Facioscapulohumeral dystrophy (FSHD) is caused by misexpression of the early embryonic transcription factor Double Homeobox Protein 4 (DUX4) in skeletal muscle. DUX4 is normally expressed at the 4-cell stage of the human embryo and initiates a portion of the first wave of embryonic gene expression that establishes the totipotent cells of the embryo. Following brief expression, the locus is suppressed by epigenetic silencing and remains silenced in nearly all somatic cells.

AI driven analysis of MRI to measure health and disease progression in FSHD.

Facioscapulohumeral muscular dystrophy (FSHD) affects roughly 1 in 7500 individuals. While at the population level there is a general pattern of affected muscles, there is substantial heterogeneity in muscle expression across- and within-patients. There can also be substantial variation in the pattern of fat and water signal intensity within a single muscle.

DUX4-induced HSATII transcription causes KDM2A/B-PRC1 nuclear foci and impairs DNA damage response.

Polycomb repressive complexes regulate developmental gene programs, promote DNA damage repair, and mediate pericentromeric satellite repeat repression. Expression of pericentromeric satellite repeats has been implicated in several cancers and diseases, including facioscapulohumeral dystrophy (FSHD). Here, we show that DUX4-mediated transcription of HSATII regions causes nuclear foci formation of KDM2A/B-PRC1 complexes, resulting in a global loss of PRC1-mediated monoubiquitination of histone H2A.

Regional and bilateral MRI and gene signatures in facioscapulohumeral dystrophy: implications for clinical trial design and mechanisms of disease progression.

Identifying the aberrant expression of DUX4 in skeletal muscle as the cause of facioscapulohumeral dystrophy (FSHD) has led to rational therapeutic development and clinical trials. Several studies support the use of MRI characteristics and the expression of DUX4-regulated genes in muscle biopsies as biomarkers of FSHD disease activity and progression. We performed lower-extremity MRI and muscle biopsies in the mid-portion of the tibialis anterior (TA) muscles bilaterally in FSHD subjects and validated our prior reports of the strong association between MRI characteristics and expression of genes regulated by DUX4 and other gene categories associated with FSHD disease activity.

snRNA-seq analysis in multinucleated myogenic FSHD cells identifies heterogeneous FSHD transcriptome signatures associated with embryonic-like program activation and oxidative stress-induced apoptosis.

The sporadic nature of DUX4 expression in FSHD muscle challenges comparative transcriptome analyses between FSHD and control samples. A variety of DUX4 and FSHD-associated transcriptional changes have been identified, but bulk RNA-seq strategies prohibit comprehensive analysis of their spatiotemporal relation, interdependence and role in the disease process. In this study, we used single-nucleus RNA-sequencing of nuclei isolated from patient- and control-derived multinucleated primary myotubes to investigate the cellular heterogeneity in FSHD.

DUX4 expression in cancer induces a metastable early embryonic totipotent program.

The transcription factor DUX4 regulates a portion of the zygotic gene activation (ZGA) program in the early embryo. Many cancers express DUX4 but it is unknown whether this generates cells similar to early embryonic stem cells. Here we identified cancer cell lines that express DUX4 and showed that DUX4 is transiently expressed in a small subset of the cells.

SMCHD1 and LRIF1 converge at the FSHD-associated D4Z4 repeat and LRIF1 promoter yet display different modes of action.

Facioscapulohumeral muscular dystrophy (FSHD) is caused by the epigenetic derepression of the 4q-linked D4Z4 macrosatellite repeat resulting in inappropriate expression of the D4Z4 repeat-encoded DUX4 gene in skeletal muscle. In 5% of FSHD cases, D4Z4 chromatin relaxation is due to germline mutations in one of the chromatin modifiers SMCHD1, DNMT3B or LRIF1. The mechanism of SMCHD1- and LRIF1-mediated D4Z4 repression is not clear.

Human DUX4 and mouse Dux interact with STAT1 and broadly inhibit interferon-stimulated gene induction.

DUX4 activates the first wave of zygotic gene expression in the early embryo. Mis-expression of DUX4 in skeletal muscle causes facioscapulohumeral dystrophy (FSHD), whereas expression in cancers suppresses IFNγ induction of major histocompatibility complex class I (MHC class I) and contributes to immune evasion. We show that the DUX4 protein interacts with STAT1 and broadly suppresses expression of IFNγ-stimulated genes by decreasing bound STAT1 and Pol-II recruitment.

Human DUX4 and porcine DUXC activate similar early embryonic programs in pig muscle cells: implications for preclinical models of FSHD.

Human DUX4 and its mouse ortholog Dux are normally expressed in the early embryo-the 4-cell or 2-cell cleavage stage embryo, respectively-and activate a portion of the first wave of zygotic gene expression. DUX4 is epigenetically suppressed in nearly all somatic tissue, whereas facioscapulohumeral dystrophy (FSHD)-causing mutations result in its aberrant expression in skeletal muscle, transcriptional activation of the early embryonic program and subsequent muscle pathology. Although DUX4 and Dux both activate an early totipotent transcriptional program, divergence of their DNA binding domains limits the use of DUX4 expressed in mice as a preclinical model for FSHD.

Facioscapulohumeral muscular dystrophy: the road to targeted therapies.

Advances in the molecular understanding of facioscapulohumeral muscular dystrophy (FSHD) have revealed that FSHD results from epigenetic de-repression of the DUX4 gene in skeletal muscle, which encodes a transcription factor that is active in early embryonic development but is normally silenced in almost all somatic tissues. These advances also led to the identification of targets for disease-altering therapies for FSHD, as well as an improved understanding of the molecular mechanism of the disease and factors that influence its progression. Together, these developments led the FSHD research community to shift its focus towards the development of disease-modifying treatments for FSHD.

Hearing Their Voices: Engaging Certified Peer Specialists in Dialogues About Racism and Recovery.

Certified peer specialists (CPSs) may be uniquely situated to help address inequities within the behavioral health system. However, CPSs and other mental health care providers often do not have opportunities to discuss their experiences with racism in the workplace. The Southeast Mental Health Technology Transfer Center and Georgia Mental Health Consumer Network offered the six-part Racism and Recovery event series as a space for such discussions (N=356 participants).

Behavioral healthcare organizations' experiences related to use of telehealth as a result of the COVID-19 pandemic: an exploratory study.

Background: Due to the COVID-19 pandemic, healthcare providers were forced to shift many services quickly from in-person to virtual, including substance use disorder (SUD) and mental health (MH) treatment services. This led to a sharp increase in telehealth services, with health systems seeing patients virtually at hundreds of times the rate as before the onset of the COVID-19 pandemic. By analyzing qualitative data about SUD and MH care organizations' experiences using telehealth, this study aims to elucidate emergent themes related to telehealth use by the front-line behavioral health workforce.

Unchecked oxidative stress in skeletal muscle prevents outgrowth of disseminated tumour cells.

Skeletal muscle has long been recognized as an inhospitable site for disseminated tumour cells (DTCs). Yet its antimetastatic nature has eluded a thorough mechanistic examination. Here, we show that DTCs traffic to and persist within skeletal muscle in mice and in humans, which raises the question of how this tissue suppresses colonization.

Facioscapulohumeral dystrophy transcriptome signatures correlate with different stages of disease and are marked by different MRI biomarkers.

With several therapeutic strategies for facioscapulohumeral muscular dystrophy (FSHD) entering clinical testing, outcome measures are becoming increasingly important. Considering the spatiotemporal nature of FSHD disease activity, clinical trials would benefit from non-invasive imaging-based biomarkers that can predict FSHD-associated transcriptome changes. This study investigated two FSHD-associated transcriptome signatures (DUX4 and PAX7 signatures) in FSHD skeletal muscle biopsies, and tested their correlation with a variety of disease-associated factors, including Ricci clinical severity score, disease duration, D4Z4 repeat size, muscle pathology scorings and functional outcome measures.

Elevated plasma complement components in facioscapulohumeral dystrophy.

Advances in understanding the pathophysiology of facioscapulohumeral dystrophy (FSHD) have led to several therapeutic approaches entering clinical trials and an increased need to develop biomarkers of disease activity and progression. Multiple prior studies have shown early elevation of RNAs encoding components of the complement pathways and relatively widespread activated complement complexes by immunodetection in FSHD muscle. The current study tested plasma from two independent cohorts of FSHD and control subjects and found elevated complement components in both FSHD cohorts.

Canine DUXC: implications for DUX4 retrotransposition and preclinical models of FSHD.

Mis-expression of DUX4 in skeletal muscle causes facioscapulohumeral muscular dystrophy (FSHD). Human DUX4 and mouse Dux are retrogenes derived from retrotransposition of the mRNA from the parental DUXC gene. Primates and rodents have lost the parental DUXC gene, and it is unknown whether DUXC had a similar role in driving an early pluripotent transcriptional program.

A proteomics study identifying interactors of the FSHD2 gene product SMCHD1 reveals RUVBL1-dependent DUX4 repression.

Structural Maintenance of Chromosomes Hinge Domain Containing 1 (SMCHD1) is a chromatin repressor, which is mutated in > 95% of Facioscapulohumeral dystrophy (FSHD) type 2 cases. In FSHD2, SMCHD1 mutations ultimately result in the presence of the cleavage stage transcription factor DUX4 in muscle cells due to a failure in epigenetic repression of the D4Z4 macrosatellite repeat on chromosome 4q, which contains the DUX4 locus. While binding of SMCHD1 to D4Z4 and its necessity to maintain a repressive D4Z4 chromatin structure in somatic cells are well documented, it is unclear how SMCHD1 is recruited to D4Z4, and how it exerts its repressive properties on chromatin.

Systemic delivery of a DUX4-targeting antisense oligonucleotide to treat facioscapulohumeral muscular dystrophy.

Facioscapulohumeral muscular dystrophy (FSHD) is one of the most prevalent skeletal muscle dystrophies. Skeletal muscle pathology in individuals with FSHD is caused by inappropriate expression of the transcription factor DUX4, which activates different myotoxic pathways. At the moment there is no molecular therapy that can delay or prevent skeletal muscle wasting in FSHD.