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Introduction Skin is susceptible to senescence‐associated secretory phenotype (SASP) and inflamm‐ageing partly owing to the degeneration of mitochondria. AdipoRon (AR) has protective effects on mitochondria in metabolic diseases such as diabetes. We explored the role of AR on mitochondria damage induced by skin inflamm‐ageing and its underlying mechanism. Methods Western blot, immunofluorescence and TUNEL staining were used to detect inflammatory factors and apoptosis during skin ageing. Transmission electron microscopy, ATP determination kit, CellLight Mitochondria GFP (Mito‐GFP), mitochondrial stress test, MitoSOX and JC‐1 staining were used to detect mitochondrial changes. Western blot was applied to explore the underlying mechanism. Flow cytometry, scratch test, Sulforhodamine B assay and wound healing test were used to detect the effects of AR on cell apoptosis, migration and proliferation. Results AR attenuated inflammatory factors and apoptosis that increased in aged skin, and improved mitochondrial morphology and function. This process at least partly depended on the suppression of dynamin‐related protein 1 (Drp1)‐mediated excessive mitochondrial division. More specifically, AR up‐regulated the phosphorylation of Drp1 at Serine 637 by activating AMP‐activated protein kinase (AMPK), thereby inhibiting the mitochondrial translocation of Drp1. Moreover, AR reduced mitochondrial fragmentation and the production of superoxide, preserved the membrane potential and permeability of mitochondria and accelerated wound healing in aged skin. Conclusion AR rescues the mitochondria in aged skin by suppressing its excessive division mediated by Drp1.

BackgroundTumor cells use aerobic glycolysis to rapidly generate ATP and growth substrate which expenses a large amount of glucose. However, how tumor cells take in enough glucose from the tumor microenvironment of insufficient blood supply remains poorly understood. The cellular FLICE-like inhibitory protein (FLIP), a cell apoptosis inhibiting molecule, is highly expressed in hepatocellular carcinoma (HCC) and is implicated in HCC development.MethodsThe effects of FLIPL (the long form of FLIP) on aerobic glycolysis and glucose uptake were assessed in HCC cells and xenograft tumors. The correlations between FLIPL expression and sodium/glucose cotransporter 1 (SGLT1) expression in clinical HCC tissues were analyzed. The consequences of FLIPL-induced regulation of SGLT1 at the transcription and translation levels and the interaction between FLIPL and SGLT1 were examined. FLIPL-mediated tolerance upon glucose limitation and its mechanism were detected.ResultsWe report a novel role for FLIPL in promoting the aerobic glycolysis of HCC cells. FLIPL overexpression induced a significant increase in cell aerobic glycolysis indexes including glucose uptake, glucose consumption, and lactate production. FLIPL co-localized and interacted with SGLT1, a major active glucose transporter in HCC cells. FLIPL increased the stability of SGLT1 protein by inhibiting its ubiquitination and degradation. The expression level of FLIPL was positively correlated with the expression level of SGLT1 in 79 HCC tissues from surgical operation. Furthermore, FLIPL increased cell tolerance ability and decreased cell apoptosis to low glucose by regulating SGLT1.ConclusionsOur results indicate that FLIPL plays an essential role in HCC aerobic glycolysis and that SGLT1 is required for FLIPL-modulated tumor proliferation under low glucose conditions. Targeting the actions of FLIPL in cell glucose-dependent aerobic glycolysis may provide an attractive strategy for therapeutic intervention in HCC.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-016-0358-3) contains supplementary material, which is available to authorized users.

Background Aging skin is characterized by a disturbed structure and lack of blood supply, which makes it difficult to heal once injured. ADSCs secrete large amounts of cytokines, which promote wound healing and vascular regeneration through paracrine secretion, and the number of cytokines can be elevated by hypoxic pretreating. However, the components of ADSCs are difficult to retain in wounds. Gelatin methacrylate (GelMA) is a photopolymerizable hydrogel synthesized from gelatin and has recently emerged as a potentially attractive material for tissue engineering applications. GelMA loaded with concentrated hypoxic pretreated ADSCs conditioned medium could provide a new method of treating wounds in aged skin. Methods Primary ADSCs were isolated from human adipose tissue and characterized by flow cytometry and differentiation test. ADSCs in passages 4-6 were pretreated in the hypoxic and normoxic environments to collect conditioned medium, the conditioned medium was then concentrated to prepare concentrated ADSCs conditioned medium(cADSC-CM)(the one collected from ADSCs under hypoxia was called hypo-CM ,and the one from normoxia was called nor-CM). The concentration of cytokines was detected. After treated with cADSC-CM, the abilities of proliferation, migration, and tube formation of human umbilical vascular endothelial cells (HUVECs) were assayed, and Akt/mTOR and MAPK signal pathway was detected using western blotting. GelMA+hypo-CM hydrogel was prepared, and a comprehensive evaluation of morphology, protein release efficiency, degradation rate, mechanical properties, and rheology properties were performed. Full-thickness skin wounds were created on the backs of 20-month-old mice. After surgery, GelMA, GelMA+F12, GelMA+hypo-CM, and GelMA+nor-CM were applied to the wound surface respectively. H&E, Masson, and immunohistochemistry staining were performed, and a laser Doppler perfusion imager was used to evaluate the blood perfusion. The student’s t-test was used for analysis between two groups and a one-way analysis of variance (ANOVA) was used for analysis among multi groups. Results Our results revealed that 1) wounds in aged skin healed more slowly than that in young skin and exhibited poorer perfusion; 2) hypoxic pretreated ADSCs secreted more cytokines including VEGF by activating HIF1α; 3) hypo-CM promoted proliferation and migration of HUVECs through VEGF/Akt/mTOR and MAPK signal pathway; 4) GelMA-hypoCM accelerated wound healing and angiogenesis in aged skin in vivo. Conclusion GelMA loaded with concentrated hypoxic pretreated adipose-derived mesenchymal stem cells conditioned medium could accelerate wound healing in aged skin by promoting angiogenesis.