Objective To explore the effects of adipose-derived stem cell released exosomes (ADSC-Exos) on the proliferation, migration, and tube-like differentiation of human umbilical vein endothelial cells (HUVECs). Methods Adipose tissue voluntarily donated by liposuction patients was obtained. The ADSCs were harvested by enzyme digestion and identified by flow cytometry and adipogenic induction. The ADSC-Exos were extracted from the supernatant of the 3rd generation ADSCs and the morphology was observed by transmission electron microscopy. The surface proteins (Alix and CD63) were detected by Western blot. The nanoparticle tracking analyzer NanoSight was used to analyze the size distribution of ADSC-Exos. After co-culture of PKH26 fluorescently labeled ADSC-Exos with HUVECs, confocal microscopy had been used to observe whether ADSC-Exos could absorbed by HUVECs. ADSC-Exos and HUVECs were co-cultured for 1, 2, 3, 4, and 5 days. The effect of ADSC-Exos on the proliferation of HUVECs was detected by cell counting kit 8 (CCK-8) assay. The expression of VEGF protein in the supernatant of HUVECs with or without ADSC-Exos had been detected by ELISA after 12 hours. Transwell migration assay was used to detect the effect of ADSC-Exos on the migration ability of HUVECs. The effect of ADSC-Exos on the tubular structure formation of HUVECs was observed by Matrigel experiments in vitro. The formation of subcutaneous tubular structure in vivo was observed in BALB/c male nude mice via the injection of HUVECs and Matrigel with or without ADSC-Exos. After 2 weeks, the neovascularization in Matrigel was measured and mean blood vessel density (MVD) was calculated. The above experiments were all controlled by the same amount of PBS. Results After identification, the cultured cells were consistent with the characteristics of ADSCs. ADSC-Exos were circular or elliptical membranous vesicle with uniform morphology under transmission electron microscopy, and expresses the signature proteins Alix and CD63 with particle size ranging from 30 to 200 nm. Confocal microscopy results showed that ADSC-Exos could be absorbed by HUVECs. The CCK-8 analysis showed that the cell proliferation of the experimental group was better than that of the control group at each time point (P<0.05). The result of Transwell showed that the trans-membrane migration cells in the experimental group were significantly more than that in the control group (t=9.534, P=0.000). In vitro, Matrigel tube-forming experiment showed that the number of tube-like structures in the experimental group was significantly higher than that of the control group (t=15.910, P=0.000). In vivo, the MVD of the experimental group was significantly higher than that of the control group (t=16.710, P=0.000). The ELISA assay showed that the expression of VEGF protein in the supernatant of the experimental group was significantly higher than that of the control group (t=21.470, P=0.000). Conclusion ADSC-Exos can promote proliferation, migration, and tube-like structure formation of HUVECs, suggesting that ADSC-Exos can promote angiogenesisin vitro and in vivo.
Objective To summarize the bioactive substances contained in bacterial extracellular vesicles (EVs) and their mechanisms in mediating bacterial-bacterial and bacterial-host interactions, as well as their mechanisms for use in implant infection-associated clinical guidance. Methods A wide range of publications on bacterial-derived EVs were extensively reviewed, analyzed, and summarized. Results Both gram-negative bacteria (G– bacteria) and gram-positive bacteria (G+ bacteria) can secrete EVs which contain a variety of bioactive substances, including proteins, lipids, nucleic acids, and virulence factors, and mediate bacterial-bacterial and bacterial-host interactions. EVs play an important role in the pathogenic mechanism of bacteria. Conclusion Bioactive substances contained within bacteria-derived EVs play an important role in the pathogenesis of bacterial infectious diseases. In-depth study and understanding of their pathogenic mechanisms can provide new insights which will improve early clinical diagnosis, prevention, and treatment of implant-associated infection. However, at present, research in this area is still in its infancy, and many more in-depth mechanisms need to be further studied.
ObjectiveTo summarize the research progress of mesenchymal stem cells derived exosomes (MSCs-EXOs) in wound repair in recent years.MethodsThe literature about the role of MSCs-EXOs in wound repair at home and abroad was extensively consulted. The mechanism of MSCs-EXOs in wound repair and its clinical application prospects were summarized and analyzed.ResultsMSCs-EXOs can inhibit early inflammatory reaction, promote angiogenesis, proliferation, and migration of epithelial cells, regulate collagen synthesis, and inhibit scar proliferation in the later stage of wound healing. Compared with MSCs, MSCs-EXOs have many advantages, such as high stability, easy storage, non-tumorigenicity, no proliferation, easy quantitative use, and so on. It has broad clinical application prospects.ConclusionMSCs-EXOs can promote wound repair and hopefully develop into a clinical product to promote the repair of acute or chronic wounds.
ObjectiveTo investigate the effect of adipose-derived stem cell derived exosomes (ADSC-Exos) on angiogenesis after skin flap transplantation in rats.MethodsADSCs were isolated and cultured by enzymatic digestion from voluntary donated adipose tissue of patients undergoing liposuction. The 3rd generation cells were observed under microscopy and identified by flow cytometry and oil red O staining at 14 days after induction of adipogenesis. After cells were identified as ADSCs, ADSC-Exos was extracted by density gradient centrifugation. And the morphology was observed by transmission electron microscopy, the surface marker proteins (CD63, TSG101) were detected by Western blot, and particle size distribution was measured by nanoparticle size tracking analyzer. Twenty male Sprague Dawley rats, weighing 250-300 g, were randomly divided into ADSC-Exos group and PBS group with 10 rats in each group. ADSC-Exos (ADSC-Exos group) and PBS (PBS group) were injected into the proximal, middle, and distal regions of the dorsal free flaps with an area of 9 cm×3 cm along the long axis in the two groups. The survival rate of the flap was measured on the 7th day, and then the flap tissue was harvested. The tissue morphology was observed by HE staining, and mean blood vessel density (MVD) was measured by CD31 immunohistochemical staining.ResultsADSCs were identified by microscopy, flow cytometry, and adipogenic induction culture. ADSC-Exos was a round or elliptical membrane vesicle with clear edge and uniform size. It has high expression of CD63 and TSG101, and its size distribution was 30-200 nm, which was in accordance with the size range of Exos. The distal necrosis of the flaps in the ADSC-Exos group was milder than that in the PBS group. On the 7th day, the survival rate of the flaps in the ADSC-Exos group was 64.2%±11.5%, which was significantly higher than that in the PBS group (31.0%±6.6%; t=7.945, P=0.000); the skin appendages in the middle region of the flap in the ADSC-Exos group were more complete, the edema in the proximal region was lighter and the vasodilation was more extensive. MVD of the ADSC-Exos group was (103.3±27.0) /field, which was significantly higher than that of the PBS group [(45.3±16.2)/field; t=3.190, P=0.011].ConclusionADSC-Exos can improve the blood supply of skin flaps by promoting the formation of neovascularization after skin flap transplantation, thereby improve the survival rate of skin flaps in rats.
ObjectiveTo investigate the effects of adipose-derived stem cell released exosomes (ADSC-Exos) on wound healing in diabetic mice.MethodsThe ADSCs were isolated from the adipose tissue donated by the patients and cultured by enzymatic digestion. The supernatant of the 3rd generation ADSCs was used to extract Exos (ADSC-Exos). The morphology of ADSC-Exos was observed by transmission electron microscopy. The membrane-labeled proteins (Alix and CD63) were detected by Western blot, and the particle size distribution was detected by nanoparticle tracking analyzer. The fibroblasts were isolated from the skin tissue donated by the patients and cultured by enzymatic digestion. The 5th generation fibroblasts were cultured with PKH26-labeled ADSC-Exos, and observed by confocal fluorescence microscopy. The effects of ADSC-Exos on proliferation and migration of fibroblasts were observed with cell counting kit 8 (CCK-8) and scratch method. Twenty-four 8-week-old Balb/c male mice were used to prepare a diabetic model. A full-thickness skin defect of 8 mm in diameter was prepared on the back. And 0.2 mL of ADSC-Exos and PBS were injected into the dermis of the experimental group (n=12) and the control group (n=12), respectively. On the 1st, 4th, 7th, 11th, 16th, and 21st days, the wound healing was observed and the wound healing rate was calculated. On the 7th, 14th, and 21st days, the histology (HE and Masson) and CD31 immunohistochemical staining were performed to observe the wound structure, collagen fibers, and neovascularization.ResultsADSC-Exos were the membranous vesicles with clear edges and uniform size; the particle size was 40-200 nm with an average of 102.1 nm; the membrane-labeled proteins (Alix and CD63) were positive. The composite culture observation showed that ADSC-Exos could enter the fibroblasts and promote the proliferation and migration of fibroblasts. Animal experiments showed that the wound healing of the experimental group was significantly faster than that of the control group, and the wound healing rate was significantly different at each time point (P<0.05). Compared with the control group, the wound healing of the experimental group was better. There were more microvessels in the early healing stage, and more deposited collagen fibers in the late healing stage. There were significant differences in the length of wound on the 7th, 14th, and 21st days, the number of microvessels on the 7th and 14th days, and the rate of deposited collagen fibers on the 14th and 21st days between the two groups (P<0.05).ConclusionADSC-Exos can promote the wound healing in diabetic mice by promoting angiogenesis and proliferation and migration of fibroblasts and collagen synthesis.
ObjectiveTo summarize the relationship between exosomes and the occurrence and development of gastrointestinal cancer.MethodsThrough online database, we collected the literatures about the relationship between exosomes and the development of gastrointestinal cancer at home and abroad, and then made an review.ResultsExosomes secreted by gastrointestinal cancer cells were related to tumorigenesis, tumor cell survival, chemoresistance, and early metastasis. Exosomes could play the role of information transmission, and regulation of cell physiology and pathological process in the development of gastrointestinal cancer through a variety of intercellular binding ways, and affectted the occurrence and development of gastrointestinal cancer via epigenetic regulation and tumor related signal transduction mechanism. They had been proved to be biomarkers, targets, and drug carriers for the treatment of gastrointestinalcancer.ConclusionIt is a new way to explore the molecular mechanism of exosomes in the development of gastrointestinal cancer.
Exosomes are nanoscale vectors with a diameter of 30~100 nm secreted by living cells, and they are important media for intercellular communication. Recent studies have demonstrated that exosomes can not only serve as biomarkers for diagnosis, but also have great potential as natural drug delivery vectors. Exosomes can be loaded with therapeutic cargos, including small molecules, proteins, and oligonucleotides. Meanwhile, the unique biological compatibility, high stability, and tumor targeting of exosomes make them attractive in future tumor therapy. Though exosomes can effectively deliver bioactive materials to receptor cells, there is a wide gap between our current understanding of exosomes and their application as ideal drug delivery systems. In this review, we will briefly introduce the function and composition of exosomes, and mainly summarize the potential advantages and challenges of exosomes as drug carriers. Finally, this review is expected to provide new ideas for the development of exosome-based drug delivery systems.
ObjectiveTo explore the potential therapeutic effects of endothelial progenitor cells derived small extracellular vesicles (EPCs-sEVs) on spinal cord injury in mice.MethodsEPCs were separated from femur and tibia bone marrow of 20 C57BL/6 male mice, and identified by double fluorescence staining and flow cytometry. Then the EPCs were passaged and the cell supernatants from P2-P4 generations EPCs were collected; the EPCs-sEVs were extracted by ultracentrifugation and identified by transmission electron microscopy, nanoflow cytometry, and Western blot. Forty C57BL/6 female mice were randomly divided into 4 groups (n=10). The mice were only removed T10 lamina in sham group, and prepared T10 spinal cord injury models in the model group and the low and high concentration intervention groups. After 30 minutes, 3 days, and 7 days of operation, the mice in low and high concentration intervention groups were injected with EPCs-sEVs at concentrations of 1×109 and 1×1010cells/mL through the tail vein, respectively. The behavioral examinations [Basso Mouse Scale (BMS) score, inclined plate test, Von Frey test] , and the gross, HE staining, and immunohistochemical staining were performed to observe the structural changes of the spinal cord at 4 weeks after operation. Another 3 C57BL/6 female mice were taken to prepare T10 spinal cord injury models, and DiR-labeled EPCs- sEVs were injected through the tail vein. After 30 minutes, in vivo imaging was used to observe whether the EPCs-sEVs reached the spinal cord injury site.ResultsAfter identification, EPCs and EPCs-sEVs derived from mouse bone marrow were successfully obtained. In vivo imaging of the spinal cord showed that EPCs-sEVs were recruited to the spinal cord injury site within 30 minutes after injection. There was no significant difference in BMS scores and the maximum angle of the inclined plate test between two intervention groups and the model group within 2 weeks after operation (P>0.05), while both were significantly better than the model group (P<0.05) after 2 weeks. The Von Frey test showed that the mechanical pain threshold of the two intervention groups were significantly higher than that of model group and lower than that of sham group (P<0.05); there was no significant difference between two intervention groups (P>0.05). Compared with the model group, the injured segment of the two intervention groups had smaller spinal cord tissue defects, less mononuclear cells infiltration, more obvious tissue structure recovery, and more angiogenesis, and these differences were significant (P<0.05); there was no significant difference between the two intervention groups.ConclusionEPCs-sEVs can promote the repair of spinal cord injury in mice and provide a new plan for the biological treatment of spinal cord injury.
ObjectiveTo investigate whether exosomes derived from miR-27a-overexpressing human umbilical vein endothelial cells (HUVECs)—exo (miR-27a) can promote bone regeneration and improve glucocorticoids (GC) induced osteonecrosis of femoral head (ONFH) (GC-ONFH).MethodsThe exo (miR-27a) were intended to be constructed and identified by transmission electron microscopy, nanoparticle tracking analysis, Western blot, and real-time fluorescent quantitative PCR (qRT-PCR). qRT-PCR was used to evaluate the effect of exo (miR-27a) in delivering miR-27a to osteoblasts (MC3T3-E1 cells). Alkaline phosphatase staining, alizarin red staining, and qRT-PCR were used to evaluate its effect on MC3T3-E1 cells osteogenesis. Dual-luciferase reporter (DLRTM) assay was used to verify whether miR-27a targeting Dickkopf WNT signaling pathway inhibitor 2 (DKK2) was a potential mechanism, and the mechanism was further verified by qRT-PCR, Western blot, and alizarin red staining in MC3T3-E1 cells. Finally, the protective effect of exo (miR-27a) on ONFH was verified by the GC-ONFH model in Sprague Dawley (SD) rats.ResultsTransmission electron microscopy, nanoparticle tracking analysis, Western blot, and qRT-PCR detection showed that exo (miR-27a) was successfully constructed. exo (miR-27a) could effectively deliver miR-27a to MC3T3-E1 cells and enhance their osteogenic capacity. The detection of DLRTM showed that miR-27a promoted bone formation by directly targeting DDK2. Micro-CT and HE staining results of animal experiments showed that tail vein injection of exo (miR-27a) improved the osteonecrosis of SD rat GC-ONFH model.Conclusionexo (miR-27a) can promote bone regeneration and protect against GC-ONFH to some extent.
ObjectiveTo evaluate the changes in the expression and significance of serum exosomal miRNAs in patients with DeBakey typeⅠacute aortic dissection (AAD). MethodsTwelve male patients with AAD and six healthy male medical examiners from our hospital were retrospectively included in this study. According to the time of chest pain, the AAD patients were divided into an AAD group within 24 h of chest pain onset, aged 47.00±8.79 years and an AAD group within 48 h of chest pain onset, aged 50.17±9.99 years. The healthy males were allocated to a control group, aged 49.17±4.26 years. Serum exosomal miRNAs were isolated, identified and quantified, and then differentially expressed exosomal miRNAs were screened. The bioinformatic analyses such as GO and KEGG were performed on the differentially expressed exosomal miRNAs. ResultsHigh-throughput screening results revealed differential expression of AAD serum exosomal miRNAs. The upregulated miRNAs of AAD groups was hsa-miR-574-5p (P<0.05), and downregulated miRNAs were hsa-miR-223-3p, hsa-miR-146b-5p, hsa-miR-15b-5p, and hsa-miR-155-5p (P<0.05). Further bioinformatic analysis of the above miRNAs revealed that they were mainly enriched in signaling pathways such as transforming growth factor-β, cell cycle and endoplasmic reticulum protein synthesis. ConclusionDifferential expressions of serum exosomal miRNAs in AAD patients may be related to the pathogenesis of AAD, providing new ideas and clues for further exploration of AAD diagnostic markers and pathogenesis.