Transcriptomic and lipidomic profiling reveals distinct bioactive lipid signatures in slow and fast muscles and highlights the role of resolvin-D2 in fiber type determination during myogenesis.

Skeletal muscles are predominantly composed of long, multinucleated muscle fibers, classified according to their metabolic and contractile phenotype. The determination of fiber types is influenced by various factors (e.g.

Apelin stimulation of the vascular skeletal muscle stem cell niche enhances endogenous repair in dystrophic mice.

Impaired skeletal muscle stem cell (MuSC) function has long been suspected to contribute to the pathogenesis of muscular dystrophy (MD). Here, we showed that defects in the endothelial cell (EC) compartment of the vascular stem cell niche in mouse models of Duchenne MD, laminin α2-related MD, and collagen VI-related myopathy were associated with inefficient mobilization of MuSCs after tissue damage. Using chemoinformatic analysis, we identified the 13-amino acid form of the peptide hormone apelin (AP-13) as a candidate for systemic stimulation of skeletal muscle ECs.

Clearance of defective muscle stem cells by senolytics restores myogenesis in myotonic dystrophy type 1.

Muscle stem cells, the engine of muscle repair, are affected in myotonic dystrophy type 1 (DM1); however, the underlying molecular mechanism and the impact on the disease severity are still elusive. Here, we show using patients' samples that muscle stem cells/myoblasts exhibit signs of cellular senescence in vitro and in situ. Single cell RNAseq uncovers a subset of senescent myoblasts expressing high levels of genes related to the senescence-associated secretory phenotype (SASP).

Physical Activity and Patient-Reported Outcomes in Monoclonal Plasma Cell Disorders.

Introduction: Plasma cell disorders (PCD) are a group of conditions characterized by disproportionate proliferation of a single clone of B lymphocytes. Multiple myeloma (MM) is a malignant type of plasma cell disorders. Improvements in MM survival have led patients and physicians to pursue strategies to improve quality of life for those living longer with this disease.

-acetylneuraminate pyruvate lyase controls sialylation of muscle glycoproteins essential for muscle regeneration and function.

Deleterious variants in acetylneuraminate pyruvate lyase (NPL) cause skeletal myopathy and cardiac edema in humans and zebrafish, but its physiological role remains unknown. We report generation of mouse models of the disease: , carrying the human p.Arg63Cys variant, and with a 116-bp exonic deletion.

An engineered multicellular stem cell niche for the 3D derivation of human myogenic progenitors from iPSCs.

Fate decisions in the embryo are controlled by a plethora of microenvironmental interactions in a three-dimensional niche. To investigate whether aspects of this microenvironmental complexity can be engineered to direct myogenic human-induced pluripotent stem cell (hiPSC) differentiation, we here screened murine cell types present in the developmental or adult stem cell niche in heterotypic suspension embryoids. We identified embryonic endothelial cells and fibroblasts as highly permissive for myogenic specification of hiPSCs.

Assessment of Muscle Function Following hiPSC-Derived Myoblast Transplantation in Dystrophic Mice.

Muscular dystrophies are caused by genetic variants in genes encoding for proteins important for muscle structure or function, leading to a loss of muscle integrity and muscle wasting. To this day, no cure has been found for these diseases. Different therapeutic approaches are under intensive investigation.

Fibro-adipogenic progenitors in skeletal muscle homeostasis, regeneration and diseases.

Skeletal muscle possesses a remarkable regenerative capacity that relies on the activity of muscle stem cells, also known as satellite cells. The presence of non-myogenic cells also plays a key role in the coordination of skeletal muscle regeneration. Particularly, fibro-adipogenic progenitors (FAPs) emerged as master regulators of muscle stem cell function and skeletal muscle regeneration.

Macrophages Are Key Regulators of Stem Cells during Skeletal Muscle Regeneration and Diseases.

Muscle regeneration is a closely regulated process that involves a variety of cell types such as satellite cells, myofibers, fibroadipogenic progenitors, endothelial cells, and inflammatory cells. Among these different cell types, macrophages emerged as a central actor coordinating the different cellular interactions and biological processes. Particularly, the transition of macrophages from their proinflammatory to their anti-inflammatory phenotype was shown to regulate inflammation, myogenesis, fibrosis, vascularization, and return to homeostasis.

Estimating the dim light melatonin onset of adolescents within a 6-h sampling window: the impact of sampling rate and threshold method.

Objective/background: Circadian rhythm sleep-wake disorders (CRSWDs) often manifest during the adolescent years. Measurement of circadian phase such as the dim light melatonin onset (DLMO) improves diagnosis and treatment of these disorders, but financial and time costs limit the use of DLMO phase assessments in clinic. The current analysis aims to inform a cost-effective and efficient protocol to measure the DLMO in older adolescents by reducing the number of samples and total sampling duration.

A week in the life of full-time office workers: work day and weekend light exposure in summer and winter.

Little is known about the light exposure in full-time office workers, who spend much of their workdays indoors. We examined the 24-h light exposure patterns of 14 full-time office workers during a week in summer, and assessed their dim light melatonin onset (DLMO, a marker of circadian timing) at the end of the working week. Six workers repeated the study in winter.

Home lighting before usual bedtime impacts circadian timing: a field study.

Laboratory studies suggest that evening light before bedtime can suppress melatonin. Here, we measured the range of evening light intensity people can generate with their household lights, and for the first time determined if varying home light before usual bedtime can shift circadian phase. This was a 3-week study with two counterbalanced conditions separated by a 5-day break.

Blacks (African Americans) have shorter free-running circadian periods than whites (Caucasian Americans).

The length of the free-running period (τ) affects how an animal re-entrains after phase shifts of the light-dark (LD) cycle. Those with shorter periods adapt faster to phase advances than those with longer periods, whereas those with longer periods adapt faster to phase delays than those with shorter periods. The free-running period of humans, measured in temporal isolation units and in forced desychrony protocols in which the day length is set beyond the range of entrainment, varies from about 23.

Human phase response curve to intermittent blue light using a commercially available device.

Light shifts the timing of the circadian clock according to a phase response curve (PRC). To date, all human light PRCs have been to long durations of bright white light. However, melanopsin, the primary photopigment for the circadian system, is most sensitive to short wavelength blue light.

Evaluation of microorganisms cultured from injured and repressed tissue regeneration sites in endangered giant aquatic Ozark Hellbender salamanders.

Investigation into the causes underlying the rapid, global amphibian decline provides critical insight into the effects of changing ecosystems. Hypothesized and confirmed links between amphibian declines, disease, and environmental changes are increasingly represented in published literature. However, there are few long-term amphibian studies that include data on population size, abnormality/injury rates, disease, and habitat variables to adequately assess changes through time.

Calculating the dim light melatonin onset: the impact of threshold and sampling rate.

The dim light melatonin onset (DLMO) is the most reliable circadian phase marker in humans, but the cost of assaying samples is relatively high. Therefore, the authors examined differences between DLMOs calculated from hourly versus half-hourly sampling and differences between DLMOs calculated with two recommended thresholds (a fixed threshold of 3 pg/mL and a variable "3k" threshold equal to the mean plus two standard deviations of the first three low daytime points). The authors calculated these DLMOs from salivary dim light melatonin profiles collected from 122 individuals (64 women) at baseline.

Human phase response curves to three days of daily melatonin: 0.5 mg versus 3.0 mg.

Context: Phase response curves (PRCs) to melatonin exist, but none compare different doses of melatonin using the same protocol.

Objective: The aim was to generate a PRC to 0.5 mg of oral melatonin and compare it to our previously published 3.

The MonoPrep Pap test for the detection of cervical cancer and its precursors. Part I: results of a multicenter clinical trial.

The MonoPrep Pap Test (MPPT; MonoGen, Lincolnshire, IL) is a novel, liquid-based specimen collection and processing technology for cytologic and molecular testing. Its usefulness in the detection of cervical cancer and its precursors was evaluated in a multicenter, masked, adjudicated, split-sample study of 10,739 samples. After preparation of a conventional smear, the residuum on the collection device was rinsed into a collection vial from which an MPPT slide was prepared.

Primary lymphoma of the larynx: new diagnostic and therapeutic approaches.

Tumors primary in the larynx, when not of squamous cell origin, require special diagnostic and therapeutic attention. An unexpected case of non-Hodgkin's lymphoma localized in the larynx in a patient with a brief history of dysphagia and hoarseness is discussed. This supraglottic tumor was extensively characterized at our institution for morphologic features by microlaryngoscopy, histology, immunocytochemical profiles with flow cytometry, chromosomal aberrations using banded karyotyping and extent of disease via PET-CT imaging.

Myoepithelial neoplasia of the submandibular gland: case report and therapeutic considerations.

Tumors of the submandibular gland typically arise from the seromucinous acini, which make up the majority of the gland. The most common benign tumor of this structure is the pleomorphic adenoma, whereas the most common malignancy of the submandibular gland is adenoid cystic carcinoma. We describe an unusual case of a neoplastic process of the myoepithelial cells of the submandibular gland in a middle-aged woman.