Spatially resolved proteomic map shows that extracellular matrix regulates epidermal growth.

Human skin comprises stratified squamous epithelium and dermis with various stromal cells and the extracellular matrix (ECM). The basement membrane (BM), a thin layer at the top of the dermis, serves as a unique niche for determining the fate of epidermal stem cells (EpSCs) by transmitting physical and biochemical signals to establish epidermal cell polarity and maintain the hierarchical structure and function of skin tissue. However, how stem cell niches maintain tissue homeostasis and control wound healing by regulating the behavior of EpSCs is still not completely understood. In this study, a hierarchical skin proteome map is constructed using spatial quantitative proteomics combined with decellularization, laser capture microdissection, and mass spectrometry. The specific functions of different structures of normal native skin tissues or tissues with a dermatologic disease are analyzed in situ. Transforming growth factor-beta (TGFß)-induced protein ig-h3 (TGFBI), an ECM glycoprotein, in the BM is identified that could enhance the growth and function of EpSCs and promote wound healing. Our results provide insights into the way in which ECM proteins facilitate the growth and function of EpSCs as part of an important niche. The results may benefit the clinical treatment of skin ulcers or diseases with refractory lesions that involve epidermal cell dysfunction and re-epithelialization block in the future.

Application of an iPSC-Derived Organoid Model for Localized Scleroderma Therapy.

Localized scleroderma (LoS) is a rare chronic disease with extensive tissue fibrosis, inflammatory infiltration, microvascular alterations, and epidermal appendage lesions. However, a deeper understanding of the pathogenesis and treatment strategies of LoS is currently limited. In the present work, a proteome map of LoS skin is established, and the pathological features of LoS skin are characterized. Most importantly, a human-induced pluripotent stem cell-derived epithelial and mesenchymal (EM) organoids model in a 3D culture system for LoS therapy is established. According to the findings, the application of EM organoids on scleroderma skin can significantly reduce the degree of skin fibrosis. In particular, EM organoids enhance the activity of epidermal stem cells in the LoS skin and promotes the regeneration of sweat glands and blood vessels. These results highlight the potential application of organoids for promoting the recovery of scleroderma associated phenotypes and skin-associated functions. Furthermore, it can provide a new therapeutic alternative for patients suffering from disfigurement and skin function defects caused by LoS.

Semaglutide attenuates excessive exercise-induced myocardial injury through inhibiting oxidative stress and inflammation in rats.

AIMS: To investigate the protective effects and mechanism of semaglutide on exercise-induced myocardial injury. MAIN METHODS: Effects of semaglutide on lipopolysaccharide (LPS)-induced oxidative stress injuries and inflammatory response were assessed in H9c2 cell via MTT assay and Western blot. Quiet control group, over training group and three doses of semaglutide treated overtraining groups were subjected to the swimming training with increasing load for consecutive 10 weeks. Immediately after the last training, the body weight, myocardial morphological changes, injury markers and inflammatory response related proteins of the model rats were analyzed. KEY FINDINGS: Semaglutide at three concentrations in LPS treated H9c2 cells significantly increased the survival rate and inhibited the apoptosis of cardiomyocytes. Moreover, semaglutide activated AMPK pathway, improve autophagy and inhibited reactive oxygen species production in LPS treated H9C2 cells. In vivo results further revealed that chronic treatment of semaglutide induced significant increase in myocardial injury markers. The pathological histology analysis results showed that semaglutide ameliorated myocardial morphological changes, reduced area of lipid accumulation and significantly decreased the expression levels of NF-κB, TNF-α and IL-1ß. SIGNIFICANCE: Semaglutide exert the protective effects on exercise-induced cardiomyopathy by activating AMPK pathway, increasing autophagy, reducing the production of ROS and inflammation-related proteins.