Astragaloside IV - mediated endothelial progenitor cell exosomes promote autophagy and inhibit apoptosis in hyperglycemic damaged endothelial cells via miR-21/PTEN axis.

INTRODUCTION: As one of the basic components of Astragalus, Astragaloside IV (AS-IV) has a protective effect on endothelial injury caused by diabetes. AS-IV stimulated endothelial progenitor cells (EPCs) to secrete exosomes loaded with miR-21. This study aimed to investigate the effects of AS-IV-mediated EPCs exosomal miR-21 (EPC-exos-miR-21) on high glucose (HG) damaged endothelial cells. MATERIALS AND METHODS: After the isolation of EPCs derived from fetal umbilical cord blood, exosomes of EPCs were obtained by differential centrifugation. The morphology of exosomes was observed by electron microscopy. The particle size distribution of exosomes was detected by Nanoparticle Tracking Analysis. Human umbilical vein endothelial cells (HUVECs) were treated with 33 mM glucose to establish an HG injury model. Flow cytometry and TUNEL assay were used to characterize the surface markers of primary EPCs and the apoptosis of HUVECs. The gene and protein expression were detected by qPCR, immunofluorescence, and Western blotting. A dual luciferase assay was used to verify the targeting relationship of miR-21 with PTEN. RESULTS: HG environment led to time- and dose-dependent inhibition and enhancement of autophagy and apoptosis in HUVECs. AS-IV stimulated EPCs to secrete exosomes loaded with miR-21. Exosomes secreted by EPCs pretreated with AS-IV [EPC-exo(ASIV)] promoted autophagy and inhibited apoptosis in HG-impaired HUVECs. PTEN is a target of miR-21. MiR-21 carried by EPC-exo(ASIV) repressed PTEN expression in HG-impaired HUVECs. In contrast, p-AKT, p-mTOR, p-PI3K, cleaved PARP and PARP levels were upregulated. Compared to the HG group, the expression of autophagy regulatory genes (ATG5, beclin1 and LC3) was enhanced in the EPC-exo(ASIV) group and EPC-exo(ASIV)-miR-21 mimic group. In contrast, apoptosis-positive regulatory genes (Bax, caspase-3 and caspase-9) were attenuated. Further overexpression of PTEN reversed the expression of these genes. CONCLUSIONS: AS-IV-mediated EPC-exos-miR-21 could enhance autophagy and depress apoptosis in HG-damaged endothelial cells via the miR-21/PTEN axis.

Comparative Proteomic Analysis of the Effect of the Four-Herb Chinese Medicine ANBP on Promoting Mouse Skin Wound Healing.

Traditional Chinese medicine has great potential to improve wound healing. ANBP, the mixture of 4 Chinese herbs- Agrimoniapilosa, Nelumbonucifera, Boswelliacarteri, and Pollen typhae-is effective in trauma treatment while its mechanism is still elusive. In this study, quantitative proteomics and bioinformatics analyses were performed to decipher the possible roles of ANBP in accelerated wound healing of mouse skin. Among all 3171 identified proteins, 90, 71, 80, and 140 proteins were found to be differently expressed in 6 hours, 3 days, 7 days, and 14 days ANBP-treated tissues compared with corresponding control tissues, respectively. The result showed that different biological processes and pathways were activated at different healing stages. At the early healing stage, ANBP treatment mainly affected several biological processes, including immune and defense response, vascular system restoration, hemostasis and coagulation regulation, lipid metabolism and signal transduction, while muscle tissue, hair, epidermis, extracellular matrix and tissue remodeling related activities were the major events in ANBP promoted later wound healing. This is the first quantitative proteome study of ANBP-treated wound tissues, which provide a new perspective for the mechanism of ANBP accelerated wound healing and is of guiding significance for clinical application of ANBP in trauma disorders cure.

Effects of the Four-Herb Compound ANBP on Wound Healing Promotion in Diabetic Mice.

Wound healing is a troublesome problem in diabetic patients. Besides, there is also an increased risk of postsurgical wound complications for diabetic patient. It has been revealed that traditional Chinese medicine may promote healing and inhibit scar formation, while the changes of morphology and physiology of wounds on such medicine treatment still remain elusive. In this study, we first used the ultralow temperature preparation method to produce mixed superfine powder from Agrimonia pilosa (A), Nelumbo nucifera (N), Boswellia carteri (B), and Pollen typhae (P), named as ANBP. Applying ANBP on 40 streptozotocin (STZ)-induced diabetic C57BL/6 mice (4-6 weeks, 20 ± 2 g), we observed that the wound healing process was accelerated and the wound healing time was shortened (14 days, P < .05). Pathological observation using hematoxylin-eosin staining indicated that inflammatory cells were reduced (P < .05) while the thickness of granulation tissue and length of epithelial tongue were increased (P < .05). The vascular density was increased on 7 and 14 days after ANBP treatment. Masson and Sirius red staining showed that, at the early stage of trauma, the expressions of Col I and Col III, especially Col III, were increased in the ANBP group (P < .05). Studies in vitro demonstrated that tubular formation was significantly increased after ANBP treatment on human vascular endothelial cells in a dose-dependent way. Taken together, our studies revealed that ANBP treatment could accelerate wound healing, promote vascularization, and inhibit inflammation, suggesting the potential clinic application of ANBP for diabetes mellitus and refractory wounds.