Fatty degeneration and wnt10b expression in the supraspinatus muscle after surgical repair of torn rotator cuff tendon

Single-cell transcriptomic analysis of the identity and function of fibro/adipogenic progenitors in healthy and dystrophic muscle

Fibro/adipogenic progenitors (FAPs) are skeletal muscle stromal cells that support regeneration of injured myofibers and their maintenance in healthy muscles. FAPs are related to mesenchymal stem cells (MSCs/MeSCs) found in other adult tissues, but there is poor understanding of the extent of similarity between these cells. Using single-cell RNA sequencing (scRNA-seq) datasets from multiple mouse tissues, we have performed comparative transcriptomic analysis. This identified remarkable transcriptional similarity between FAPs and MeSCs, confirmed the suitability of PDGFRα as a reporter for FAPs, and identified extracellular proteolysis as a new FAP function. Using PDGFRα as a cell surface marker, we isolated FAPs from healthy and dysferlinopathic mouse muscles and performed scRNA-seq analysis. This revealed decreased FAP-mediated Wnt signaling as a potential driver of FAP dysfunction in dysferlinopathic muscles. Analysis of FAPs in dysferlin- and dystrophin-deficient muscles identified a relationship between the nature of muscle pathology and alteration in FAP gene expression.

The role of WNT10B in physiology and disease: A 10-year update

WNT10B, a member of the WNT family of secreted glycoproteins, activates the WNT/β-catenin signaling cascade to control proliferation, stemness, pluripotency, and cell fate decisions. WNT10B plays roles in many tissues, including bone, adipocytes, skin, hair, muscle, placenta, and the immune system. Aberrant WNT10B signaling leads to several diseases, such as osteoporosis, obesity, split-hand/foot malformation (SHFM), fibrosis, dental anomalies, and cancer. We reviewed WNT10B a decade ago, and here we provide a comprehensive update to the field. Novel research on WNT10B has expanded to many more tissues and diseases. WNT10B polymorphisms and mutations correlate with many phenotypes, including bone mineral density, obesity, pig litter size, dog elbow dysplasia, and cow body size. In addition, the field has focused on the regulation of WNT10B using upstream mediators, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). We also discussed the therapeutic implications of WNT10B regulation. In summary, research conducted during 2012-2022 revealed several new, diverse functions in the role of WNT10B in physiology and disease.