More and more evidence indicates that microvesicles (MVs) play a key role in cell-to-cell communication. The MVs are circular fragments of membrane released from the endosomal compartment as exosomes or shed from the cell surface membranes of most types. Components of donor cells are incorporated into MVs that contain bioactive lipids, proteins, genetic cargoes. MVs derived from stem cells may reprogram cells that survived in injury tissue and favor tissue regeneration by delivering their bioactive cargoes to influence the behaviors of recipient cells. Compared with mesenchymal stem cells (MSCs), MVs derived from MSCs were found to mimic the beneficial effects of these cells. These proregenerative effects mediated by MVs can be explained by the fact that MVs are enriched in bioactive lipids, anti-apoptotic and pro-stimulatory growth factors or cytokines, and deliver mRNAs, regulatory miRNAs and proteins that improve overall cell function. Therefore, it opens novel perspectives in exploiting these MVs in tissue regeneration and repair. In addition, the use of MVs instead of stem cells could represent a safe and potentially more advantageous alternative to cell-therapy approaches.
ObjectiveTo summarize the causes, clinical manifestations, diagnosis and treatment methods for the intestinoseminal vesicle fistula. MethodLiteratures about intestinoseminal vesicle fistula at home and abroad were retrieved, the causes, clinical manifestations, diagnosis and treatment methods were analyzed. ResultsThe clinical reports of 19 patients with intestinoseminal vesicle fistula were searched.The intestinoseminal vesicle fistula occurred after the rectal low anterior resection with stomal leak, sigmoid diverticulum, inflammatory bowel disease, prostatectomy or radiotherapy.The main clinical symptoms were pneumaturia, fecaluria, fever, scrotal swelling and pain, orchitis, epididymitis and so on.Imaging methods such as enhanced CT or CT with rectal contrast and so on could confirm the diagnosis.The conservative treatment such as indwelling catheter, antibiotics, parenteral nutrition, and the operation methods such as sinus incision and drainage, mucosa/skeletal muscle flap repairment, urine/stool bypass could cure majority of cases. ConclusionsThe intestinoseminal vesicle fistula is a rare and independent disease.Through the discussion of the intestinoseminal vesicle fistula, it could improve the knowledge, and avoid misdiagnosis and mistreatment of the intestinoseminal vesicle fistula.
ObjectiveTo review the current progresses in purification strategies, biological characters, and functions of endothelial progenitor cells (EPCs) derived extracellular vesicles (EVs) (EPC-EVs). MethodsRecent relevant publications on the EPC-EVs were extensively reviewed, analyzed, and summarized. ResultsEPC-EVs are usually isolated by differential centrifugation and exhibit a homogenous pattern of spheroid particles with a diameter ranging from 60 to 160 nm under transmission electron microscopy. EPC-EVs are positive for cell-surface markers of EPCs (CD31, CD34, and CD133), and negative for markers of platelets (P-selectin and CD42b) and monocytes (CD14). Recent studies have shown the effectiveness of EPC-EVs in ischemic injuries, anti-Thy1 glomerulonephritis, and cardiomyocyte hypertrophy, and also shown their predictive role in cardio-cerebral-vascular diseases. ConclusionAn alluring prospect exists on the EPC-EVs-related research. Further studies are required to decipher the composition of EPC-EVs and their precise role in pathophysiological processes, and to investigate the molecular mechanisms for their targeting and function.
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 observe the effect and mechanism of human umbilical cord blood mesenchymal stem cells-derived microvesicles (hUMSCs-MVs) on the injury of the primary rat retinal ganglion cells (RGCs) by high glucose environment. Methods The primary RGCs of Sprague Dawley rats were cultured in vitro, hUMSCs-MVs were isolated and extracted by ultra-centrifugation. hUMSCs-MVs were internalized with RGCs. The RGCs were divided into 4 groups under the conditions below: normal control group (group A), high glucose condition group (group B, RGCs+glucose 33 mmol/L), normal RGCs co-cultured with hUMSCs-MVs group (group C, RGCs+hUMSCs-MVs), and RGCs co-cultured with hUMSCs-MVs in high glucose condition group (group D, RGCs+hUMSCs-MVs+glucose 33 mmol/L). The cell activity was detected by CCK-8 test. Annexin Ⅴ/PI staining detected the cell apoptosis rate by flow cytometry. And the relative expression levels of the genes such as Bcl-2, Bax and Caspase-3 were detected by fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Statistical analysis was performed by using One-way analysis of variance and SNK-q test was used for the comparison between groups. Results The hUMSCs-MVs were extracted by ultra-centrifugation, which were characterized as single or cluster of circular membranous vesicle-like structure with diameter ranging from 100 nm to 1000 nm. The flow cytometry analysis showed that hUMSCS-MVs were highly positived by the surface markers of CD44, CD29, CD73, and CD105 whereas been poorly expressed the integrin (CD49f), HLA class Ⅱ, CD34, CD45. There were significant differences in the cell activity and the apoptosis rate among 4 groups, the cell apoptosis rate of group B was higher significantly than that of group A and group D (F=107.92, P=0.000), the cell activity of group B was lower than that of group A and group D (F=382.11, P=0.000). The results of RT-PCR and Western blot showed that the relative mRNA (F=219.79, 339.198, 1 071.21; P=0.000, 0.000, 0.000) and protein (F=544.28, 295.79, 224.75; P=0.000, 0.000, 0.000) expression of Bcl-2, Bax, Caspase-3 and the protein expression of cleaved Capspase-3 (F=533.18, P=0.000) in group B and D were higher significantly than those in group A and C. The relative expression of Bcl-2 mRNA and protein in group B was significantly lower than that of in group D (P＜0.05). The relative expression of Bax, Caspase-3 mRNA and protein in group B was higher than that in group D (P＜0.05). The relative expression of cleaved Caspase-3 protein in group B was higher significantly than that in group D (P＜0.05). Conclusion The hUMSCs-MVs can protect the cultured rat RGCs from the damage of the high glucose condition through increasing the cell activity and reducing the apoptosis rate of RGCs by promoting the Bcl-2 expression, decreasing the expression of Bax and Caspase-3 and inhibiting the Caspase-3 into the activity form of cleaved Caspase-3.
ObjectiveTo review the advances in utilizing paracrine effect of stem cells in knee osteoarthritis (OA) treatment.MethodsThe researches in applying stem cells derived conditioned medium, extracellular matrix, exosomes, and microvesicles in knee OA treatment and cartilage repair were reviewed and analyzed.ResultsThe satisfying outcomes of using different products of stem cells paracrine effect in knee OA condition as well as cartilage defect is revealed in studies in vitro and in vivo. The mechanism including suppressing the intraarticular inflammation, the apoptosis of chondrocytes, and the degradation of cartilage matrix, while enhancing the synthesis of cartilage matrix, the differentiation of in-situ stem cells into chondrocytes and the migration to the affected area. The effectiveness can be further improved supplemented with the tissue engineering methods or gene modification.ConclusionCompared with the traditional stem cell therapy, applying the products from paracrine effect of stem cells in knee OA treatment is more economical and safer, presenting great potential in clinical practice.
ObjectiveTo explore the possibility of constructing tissue engineered adipose by adipose tissue derived extracellular vesicles (hAT-EV) combined with decellularized adipose tissue (DAT) scaffolds, and to provide a new therapy for soft tissue defects.MethodsThe adipose tissue voluntarily donated by the liposuction patient was divided into two parts, one of them was decellularized and observed by HE and Masson staining and scanning electron microscope (SEM). Immunohistochemical staining and Western blot detection for collagen type Ⅰ and Ⅳ and laminin were also employed. Another one was incubated with exosome-removed complete medium for 48 hours, then centrifuged to collect the medium and to obtain hAT-EV via ultracentrifugation. The morphology of hAT-EV was observed by transmission electron microscopy; the nanoparticle tracking analyzer (NanoSight) was used to analyze the size distribution; Western blot was used to analyse membrane surface protein of hAT-EV. Adipose derived stem cells (ADSCs) were co-cultured with PKH26 fluorescently labeled hAT-EV, confocal fluorescence microscopy was used to observe the uptake of hAT-EV by ADSCs. Oil red O staining was used to evaluate adipogenic differentiation after hAT-EV and ADSCs co-cultured for 15 days. The DAT was scissored and then injected into the bilateral backs of 8 C57 mice (6-week-old). In experimental group, 0.2 mL hAT-EV was injected weekly, and 0.2 mL PBS was injected weekly in control group. After 12 weeks, the mice were sacrificed, and the new fat organisms on both sides were weighed. The amount of new fat was evaluated by HE and peri-lipoprotein immunofluorescence staining to evaluate the ability of hAT-EV to induce adipogenesis in vivo.ResultsAfter acellularization of adipose tissue, HE and Masson staining showed that DAT was mainly composed of loosely arranged collagen with no nucleus; SEM showed that no cells and cell fragments were found in DAT, and thick fibrous collagen bundles could be seen; immunohistochemical staining and Western blot detection showed that collagen type Ⅰ and Ⅳ and laminin were retained in DAT. It was found that hAT-EV exhibited a spherical shape of double-layer envelope, with high expressions of CD63, apoptosis-inducible factor 6 interacting protein antibody, tumor susceptibility gene 101, and the particle size of 97.9% hAT-EV ranged from 32.67 nmto 220.20 nm with a peak at 91.28 nm. Confocal fluorescence microscopy and oil red O staining showed that hAT-EV was absorbed by ADSCs and induced adipogenic differentiation. In vivo experiments showed that the wet weight of fat new organisms in the experimental group was significantly higher than that in the control group (t=2.278, P=0.048). HE staining showed that the structure of lipid droplets in the experimental group was more than that in the control group, and the collagen content in the control group was higher than that in the experimental group. The proportion of new fat in the experimental group was significantly higher than that in the control group ( t=4.648, P=0.017).ConclusionDAT carrying hAT-EV can be used as a new method to induce adipose tissue regeneration and has a potential application prospect in the repair of soft tissue defects.
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.
Objective To review the mechanism of extracellular vesicles (EVs) in treating intervertebral disc degeneration (IVDD). Methods The literature about EVs was reviewed and the biological characteristics and mechanism of EVs in the treatment of IVDD were summarized. Results EVs are a kind of nano-sized vesicles with a double-layered lipid membrane structure secreted by many types of cells. EVs contain many bioactive molecules and participate in the exchange of information between cells, thus they play important roles in inflammation, oxidative stress, senescence, apoptosis, and autophagy. Moreover, EVs are found to slow down the process of IVDD by delaying the pathological progression of the nucleus pulposus, cartilage endplates, and annulus fibrosus. Conclusion EVs is expected to become a new strategy for the treatment of IVDD, but the specific mechanism remains to be further studied.