AI-driven histologic analysis of human Achilles tendinopathy provides a roadmap to unravel pathogenesis.

Objectives: Achilles tendinopathy is a common source of pain and dysfunction, yet its pathogenesis remains poorly understood. Research on human tendons is hampered by lack of standardisation in tissue sample validation, making interpretation of results challenging. We sought to develop an automated and operator-independent approach to histologically score human tendons.

Piezo2 in sensory neurons regulates systemic and adipose tissue metabolism.

Systemic metabolism ensures energy homeostasis through inter-organ crosstalk regulating thermogenic adipose tissue. Unlike the well-described inductive role of the sympathetic system, the inhibitory signal ensuring energy preservation remains poorly understood. Here, we show that, via the mechanosensor Piezo2, sensory neurons regulate morphological and physiological properties of brown and beige fat and prevent systemic hypermetabolism.

Cellular deconstruction of the human skeletal muscle microenvironment identifies an exercise-induced histaminergic crosstalk.

Plasticity of skeletal muscle is induced by transcriptional and translational events in response to exercise, leading to multiple health and performance benefits. The skeletal muscle microenvironment harbors myofibers and mononuclear cells, but the rich cell diversity has been largely ignored in relation to exercise adaptations. Using our workflow of transcriptome profiling of individual myofibers, we observed that their exercise-induced transcriptional response was surprisingly modest compared with the bulk muscle tissue response.

Il-6 signaling exacerbates hallmarks of chronic tendon disease by stimulating reparative fibroblasts.

Tendinopathies are debilitating diseases currently increasing in prevalence and associated costs. There is a need to deepen our understanding of the underlying cell signaling pathways to unlock effective treatments. In this work, we screen cell signaling pathways in human tendinopathies and find positively enriched IL-6/JAK/STAT signaling alongside signatures of cell populations typically activated by IL-6 in other tissues.

Nicotinamide mononucleotide restores impaired metabolism, endothelial cell proliferation and angiogenesis in old sedentary male mice.

Aging is accompanied by a decline in neovascularization potential and increased susceptibility to ischemic injury. Here, we confirm the age-related impaired neovascularization following ischemic leg injury and impaired angiogenesis. The age-related deficits in angiogenesis arose primarily from diminished EC proliferation capacity, but not migration or VEGF sensitivity.