Characterization of platelet-derived extracellular vesicles induced by differential platelet activation pathways / 中国输血杂志

【Objective】 To investigate the effects of platelet activation pathways on the characterization of platelet-derived extracellular vesicles(PEVs). 【Methods】 Whole blood from healthy donors was prepared into platelet suspension by centrifugation. Platelets were randomly divided into six groups, the ctrl group added no extra stimulus, and the other five groups were treated with collagen, adenosine diphosphate(ADP), thrombin, Ca2+ ionophore and freeze-thaw cycles (F-T) to activate platelets. Platelet-derived exosomes(PEXOs) and microvesicles(PMVs) were isolated by differential centrifugations, and then were determined by nano-flow cytometry and electron microscopy. The protein markers of PEXOs also were identified by western-blot. The protein concentration and content of PEXOs were also detected. 【Results】 CD9, CD81, TSG101 proteins were detected in all of the PEXOs, which had no calnexin. Both PEXOs and PMVs had CD41; PEXOs were cup-holder-like bilayer membrane vesicles under a transmission electron microscope, while PMVs were irregular membranous structure; 85%-95% of PEXOs were<100nm, 87%-94% of PMVs were 100-300nm. The concentration of exosomes and microvesicles in the F-T group was the highest(205.67±65.27 and 102.73±15.48), followed by the Ca2+ ionophore group(44.42±17.07 and 11.4±4.81). Although in the same size range, the numbers of PEVs induced by different activation conditions varied. The protein concentration of PEXOs in the F-T group(1.11±0.51) was higher than that in the control group(0.32±0.39), ADP group(0.41±0.31) and thrombin group(0.38±0.37), while the total protein(125.40±58.32) was higher than that in other three groups(the ctrl group 25.53±25.96 vs ADP group 37.21±15.73 vs thrombin group 36.28±24.18 vs Ca2+ ionophore group 47.09±23.29). 【Conclusion】 The biological characteristics of PEVs are affected by platelets activation pathways, whose ability to induce protein-packing into exosomes may also be relevant to the particle size. The freeze-thaw cycles can induce high concentrations of extracellular vesicles, which may be an ideal method for the preparation of PEVs.

Propofol inhibits myocardial injury induced by microvesicles derived from hypoxiareoxygenated endothelial cells via lncCCT4-2/CCT4 signaling

BACKGROUND: Ischemia-reperfusion (IR) induces increased release of extracellular vesicles in the heart and exacerbates myocardial IR injury. We have previously shown that propofol attenuates hypoxia/reoxygenation (HR)-induced injury in human umbilical vein endothelial cells (HUVECs) and that microvesicles derived from propofol-treated HUVECs inhibit oxidative stress in endothelial cells. However, the role of microvesicles derived from propofol post-treated HUVECs ((HR + P)-EMVs) in IR-injured cardiomyocytes is unclear. In this study, we aimed to investigate the role of (HR + P)-EMVs in cardiac IR injury compared to microvesicles derived from hypoxic/reoxygenated HUVECs (HR-EMVs) and to elucidate the underlying mechanisms. METHODS: Hypoxia/reoxygenation (HR) models of HUVECs and AC16 cells and a mouse cardiac IR model were established. Microvesicles from HR-injured HUVECs, DMSO post-treated HUVECs and propofol post-treated HUVECs were extracted by ultra-high speed centrifugation, respectively. The above EMVs were co-cultured with HR-injured AC16 cells or injected intracardially into IR mice. Flow cytometry and immunofluorescence were used to determine the levels of oxidative stress and apoptosis in cardiomyocytes. Apoptosis related proteins were detected by Western blot. Echocardiography for cardiac function and Evans blue-TTC staining for myocardial infarct size. Expression of lncCCT4-2 in EMVs and AC16 cells was analysed by whole transcriptome sequencing of EMVs and RT-qPCR. The molecular mechanism of inhibition of myocardial injury by (HR + P)-EMVs was elucidated by lentiviral knockdown of lncCCT4-2, plasmid overexpression or knockdown of CCT4, and actinomycin D assay. RESULTS: In vitro and in vivo experiments confirmed that HR-EMVs exacerbated oxidative stress and apoptosis in IR-injured cardiomyocytes, leading to increased infarct size and worsened cardiac function. Notably, (HR + P)-EMVs induced significantly less oxidative stress and apoptosis in IR-injured cardiomyocytes compared to HR-EMVs. Mechanistically, RNA sequencing of EMVs and RT-qPCR showed that lncCCT4-2 was significantly upregulated in (HR + P)-EMVs and cardiomyocytes co-cultured with (HR + P)-EMVs. Reduction of lncCCT4-2 in (HR + P)-EMVs enhanced oxidative stress and apoptosis in IR-injured cardiomyocytes. Furthermore, the anti-apoptotic activity of lncCCT4-2 from (HR + P)-EMVs was achieved by increasing the stability of CCT4 mRNA and promoting the expression of CCT4 protein in cardiomyocytes. CONCLUSIONS: Our study showed that (HR + P)-EMVs uptake by IR-injured cardiomyocytes upregulated lncCCT4-2 in cardiomyocytes and promoted CCT4 expression, thereby inhibiting HR-EMVs induced oxidative stress and apoptosis. Highlights Microvesicles from hypoxic/reoxygenated HUVECs (HR-EMVs) exacerbated oxidative stress and apoptosis in IR-injured cardiomyocytes. Microvesicles from propofol post-treated HUVECs ((HR + P)-EMVs) induced diminished oxidative stress and apoptosis in IR-injured cardiomyocytes compared with microvesicles from hypoxic/reoxygenated HUVECs (HR-EMVs). lncCCT4-2 was significantly highly expressed in (HR + P)-EMVs and cardiomyocytes co-cultured with (HR + P)-EMVs, and reduction of lncCCT4-2 in (HR + P)-EMVs enhanced oxidative stress and apoptosis in IR-injured cardiomyocytes. lncCCT4-2 inhibited HR-EMVs induced oxidative stress and apoptosis in HR-injured AC16 cells by increasing the stability of CCT4 mRNA and promoting the expression of CCT4 protein in AC16 cells.

Extracellular vesicles in dermatology: updates and prospects / 中华皮肤科杂志

Extracellular vesicles are nanoscale vesicles secreted by cells, including exosomes and microvesicles. They can be ingested by recipient cells through a variety of mechanisms, transmitting intercellular information and regulating biological functions of recipient cells. Studies have found that extracellular vesicles are closely related to skin diseases, such as autoimmune diseases, pigmented diseases, tumors and wound healing, and play important biological roles in various physiological and pathological processes. This review summarizes updates on extracellular vesicles in dermatology.

Calcium Participates in Migration of VSMCS Synergistically Induced by Cyclic Stretch and Platelet-Derived Microvesicles / 医用生物力学

Objective To investigate the synergistic effects of pathologically elevated cyclic stretch and platelet-derived microvesicles (PMVs) on migration of vascular smooth muscle cells (VSMCs) and the potential role of calcium in this process. Methods The FX-5000T strain loading system was used to apply cyclic stretch to VSMCs with magnitudes of 5% and 15%, which simulated physiological and hypertensive situation respectively in vitro; wound healing assay was used to analyze VSMCs migration; Ca2+-free medium was used to remove extracellular calcium; 2-APB (an antagonist of IP3R) was used to inhibit the release of intercellular stored calcium; GSK219 (an antagonist of TRPV4) and Nifedipine (an inhibitor of L-type voltage-gated calcium channel) were applied to block the activity of respective calcium channel; thrombin was used to stimulate platelets in vitro which simulated the hypertensive activation of PMVs in vivo. ResultsCompared with 5% cyclic stretch, 15% cyclic stretch significantly promoted VSMC migration. Removal of extracellular calcium inhibited VSMCs migration, but the application of GSK219 and Nifedipine did not affect the migration up-regulated by 15% cyclic stretch; while 2-APB which inhibited the release of intracellular stored calcium could also repress VSMCs migration under 15% cyclic stretch. PMVs further promoted VSMC migration under 15% cyclic stretch condition, and both extracellular calcium and intercellular stored calcium were involved in this process. Conclusions Both intracellular and extracellular calcium play important roles in VSMC migration induced by 15% cyclic stretch, and PMVs synergistically participate in the above process. The study is aimed to provide new mechanobiological insights into the molecular mechanism and clinical targets of vascular remodeling in hypertension.

Prospect of mesenchymal stem cell microvesicles repairing pelvic floor organ prolapse by antioxidant stress / 中国临床药理学与治疗学

Pelvic organ prolapse (POP) is a common gynecological disease caused by pelvic floor fascia and ligament relaxation in middle-aged and elderly women. A large number of studies have shown that oxidative stress (OS) is one of the core mechanisms of POP. Mesenchymal stem cells (MSCs) are a research hotspot in regenerative medicine. Many evidences show that MSCs can play antioxidant properties in myocardial infarction, hyperoxic lung injury and other diseases, thus reducing inflammation and oxidative stress.In addition, microvesicles (MVs)derived from MSCs secreted can replicate the functions of MSCs through protein, mRNA, miRNA and lipid transport, and participate in many biological processes regulating tissue homeostasis and disease physiology and pathology. This article reviews the potential positive effects of MSCs-MVs in the treatment of POP through antioxidant stress.

Relationship between extracellular vesicles and radiation-induced tissue injury / 中国组织工程研究

BACKGROUND: Radiation-induced tissue injury is one of the more serious side effects of cancer patients after radiotherapy. Recent studies have shown that in the radiation-induced tissue injury model, extracellular vesicles as intercellular information carriers have two sides. On the one hand, they participate in the radiation-induced tissue injury process to mediate tissue damage. On the other hand, they participate in radiation-induced tissue injury repair by transferring biologically active substances. OBJECTIVE: To summarize the damage and repair effects of extracellular vesicles from different sources on radioactive tissue damage and to clarify the relationship between extracellular vesicles and radiation-induced tissue injury, which will be beneficial to explore new treatment strategies for radiationinduced tissue injury. METHODS: Databases of PubMed and CNKI were retrieved with the keywords of “extracellular vesicles, radiation-induced tissue damage (bone, brain, intestine, etc.), WNT signal” in Chinese and “radiation-induced tissue injury, extracellular vesicles, tissue repair and regeneration, vascular endothelial cells, bystander effects” in English. The retrieval time was from 1989 to 2020. After initial screening of titles and abstracts, irrelevant articles were excluded, and 61 eligible articles were included for result analysis. RESULTS AND CONCLUSION: Extracellular vesicles are membrane-closed vesicles that are naturally released from cells under normal physiological or abnormal pathological conditions. On the one hand, under pathological conditions, radioactive tissue damage cannot be separated from the mediation of extracellular vesicles; on the other hand, extracellular vesicles carrying information molecules can promote the repair of radioactive tissue damage. Therefore, in the field of radioactive tissue damage repair and regeneration, extracellular vesicles have the potential to become a new cell-free therapy, but whether it can be applied to clinical use requires more in-depth research and exploration.

Antitumoral potential of microvesicles extracted from human adipose-derived mesenchymal stem cells on human breast cancer cells

Aim of Study: One of the new methods that have promising results is the use of cell-derived microvesicles (MVs) to kill tumor cells. Given that MVs contain apoptotic materials, genes, and proteins, they can interfere with the fate of adjacent cells. Materials and Methods: In the present study, after adipose tissue-derived mesenchymal stem cells (AT-MSCs) isolation and characterization, MVs were derived from AT-MSCs and then characterized morphologically by standard error of the mean and size determination by DLS, and after that, the influence of MVs on human breast cancer cells (MCF-7) was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assay and apoptosis-related gene expression. The raw data were analyzed in SPSS.17 software. Results: The results indicated that MVs have a size range of 500–1500 nm, and the viability of MCF-7 was significantly decreased when treated by different concentrations of MVs and it was confirmed when apoptosis-related genes' expression level was measured by real-time reverse transcription polymerase chain reaction whereas demonstrated that apoptosis genes including Bax, P53, P21, and EP300 (2− ΔΔ CT) and ΔCT values were expressed significantly in MCF-7 treated by MVs higher than those nontreated, and decrease of Bcl-2 expression level in MVs-treated MCF-7 was also significant as an antiapoptosis-related gene. Conclusions: Taking together, AT-MSC-derived MVs demonstrated anticancer or antitumoral properties on MCF-7 cells, and it could also be effective for other types of cancer cells

Effects of Mesenchymal Stem Cells and Their Derived Microvesicles on Pulmonary Toxicity Induced by Petrol Exhaust Nanoparticle; Histological and Immuno-Histochemical Study

Background: Diesel vehicles exhaust contains toxic nanoparticles that drastically affect lung tissue due to their direct cytotoxic effects, induction of oxidative stress, inflammatory signaling pathways and DNA damage. Mesenchymal stem cells (MSCs) exhibit anti-inflammatory effects and efficient regenerative capacity in chronic lung diseases. Objectives: Evaluation of the effects of MSCs and MSCs-derived micro vesicles (MSCs-MVs) on pulmonary toxicity induced by diesel exhaust nanoparticles (DENPs). Materials and Methods: Sixty male rats were equally divided into: Group I (Control rats), Group II (DENPs group) received repeated doses of DENPs (180μg/rat) intratracheally every other day for 6 days, Group III (MSCs group) received MSCs intravenously (3×106 cells) after the last dose of DENPs and Group IV (MSCs-MVs group) received MSCs-MVs (0.5 mg/mL) intravenously after the last dose of DENPs. Lung tissue were subjected to histological and immunohistochemical assessment. Inflammatory cytokines and bronchoalveolar lavage fluid (BALF) contents of inflammatory cells, albumin, LDH and total proteins were evaluated. Results: Histological picture of lung tissue in DENPs group showed numerous collapsed alveoli, thick interalveolar septa and marked cellular infiltration. Elastic fibers were markedly decreased by DENPs. Increased optical density of NF-κB/p65 immunoreactivity. Bronchoalveolar lavage fluid showed significant elevation of inflammatory cytokines (TNF-a, IL-6), polymorphonuclear leukocytes (PMN), neutrophils, macrophages, LDH, total proteins and albumin. Treatment with either MSCs or MSCs-MVs led to a significant amelioration of all of the aforementioned studied parameters. Conclusion: MSCs-MVs and MSCs showed significant therapeutic effects against DENPs damaging effects on the lung tissues via their regenerative capacity and anti-inflammatory effects.

The Effect of Mesenchymal Stem Cells Derived Microvesicles on the Treatment of Experimental CCL4 Induced Liver Fibrosis in Rats

BACKGROUND AND OBJECTIVES: The release of microvesicles (MVs) from mesenchymal stem cells (MSCs) has been implicated in intercellular communication, and may contribute to beneficial paracrine effects of stem cell-based therapies. We investigated the effect of administration of MSC-MVs on the therapeutic potential of carbon tetrachloride (CCL₄) induced liver fibrosis in rats.METHODS: Our work included: isolation and further identification of bone marrow MSC-MVs by transmission electron microscopy (TEM). Liver fibrosis was induced in rats by CCl4 followed by injection of prepared MSC-MVs in injured rats. The effects of MSC-MVs were evaluated by biochemical analysis of liver functions, RNA gene expression quantitation for collagen-1α, transforming growth factor β (TGF-β), interleukin-1β (IL-1β), vascular endothelial growth factor (VEGF) by real time reverse transcription PCR (RT-PCR) techniques. Finally histopathological examination of the liver tissues was assessed for all studied groups.RESULTS: BM-MSC-MVs treated group showed significant increase in serum albumin levels, VEGF quantitative gene expression (p < 0.05), while it showed a significant decrease in serum alanine transaminase (ALT) enzyme levels, quantitative gene expression of TGF-β, collagen-1α, IL-1β compared to CCL₄ fibrotic group (p < 0.05). Additionally, the histopathological assessment of the liver tissues of BM-MSC-MVs treated group showed marked decrease in the collagen deposition & improvement of histopathological picture in comparison with CCL₄ fibrotic group.CONCLUSIONS: Our study demonstrates that BM-MSC-MVs possess anti-fibrotic, anti-inflammatory, and pro-angiogenic properties which can promote the resolution of CCL₄ induced liver fibrosis in rats.

Improvement of the retention volume of fat transplantation by adipose tissue mesenchymal stem cell-derived microvesicles / 中华整形外科杂志

Objective@#To investigate the possibility of adipose tissue mesenchymal stem cell-derived microvesicles (ADSC-MVs) to improve the retention volume of fat transplantation.@*Methods@#Human adipose tissue was obtained from 5 healthy female patients aged from 20 to 30 years, who came to the hospital for abdominal liposuction. Adipose tissue mesenchymal stem cells (ADSCs) were acquired by collagenase enzymatic hydrolysis. ADSC-MVs were isolated from the supernatant of cultured ADSCs through ultra-centrifugation, and characterized by transmission electron microscope and PKH26 staining. Sixteen BALB/c-nu nude mice were randomly divided into 2 groups (n=8, mice/group) by random number table method. In EV group, the mice were subcutaneously injected 0.35 ml human fat, with 7 μg ADSC-EVs (final concentration is 20 μg/ml), while 0.35 ml human fat were in blank group. The mice were sacrificed and the grafts were harvested at 1 month and 3 months after transplantation. Weight and volume of transplanted fat were tested. Morphology of adipocytes, fibrosis and necrosis of fat tissue were confirmed by HE staining. Blood vessel density were accessed by CD31 staining.SPSS 13.0 was used for statistical analysis and Student-t test was applied to compare the data from two groups.@*Results@#One month after fat transplantation, the volume of fat grafts in blank group was lower than that in MV group. Besides, lipoliquefaction can be observed in fat grafts of blank group. Fat grafts in MV group had a higher volume and littler necrosis and lipolique faction. Three months after grafting, the volume of fat grafts in blank group [(0.057±0.009) ml] was significantly lower than that in MV group [(0.103±0.015) ml], t=8.117, P<0.001. MV group had an increased number of vessels (29.6±4.0/field) compared with grafts from the Blank group (23.0±2.4/field), t=2.825, P=0.022. Histological analysis revealed that the fat grafts in MV group consisted less fat necrosis and fibrosis than control group.@*Conclusions@#ADSC-MVs can improve the retention volume of fat transplantation.

Effects of circulating microvesicles containing microRNA-27 a on blood brain barrier tight junction injury of ischemia stroke mice / 中国药理学通报

Aim To study the effect of circulating mi-crovesicles containing miR-27 a on blood brain barrier tight junction injury of ischemia stroke mice and its mechanism. Methods The middle cerebral artery occlusion mouse model was established, and the mi-crovesicles in the supernatant of 2 h of ischemic stroke brain tissues were separated by centrifugal ultrafiltra-tion method. The transmission electron microscopy was used to observe microvesicle morphology, and the di-ameter of microvesicles was detected. Based on the 2 h ischemia stroke mouse model, mice were injected via femoral vein with microvesicles at 5 mg · kg-1 . TTC staining was applied to detect infarction volume of is-chemia brain, while HE staining was applied to detect the expression change of tight junction protein occludin and claudin-5 . Western blot was subjected to detect occludin, claudin-5, TLR4, NF-κB and p38 protein expression. ELISA method was used to measure the contents of cytokines IL-1β and TNF-α. Results The microvesicle shape was approximately circular bi-lateral membrane structure, with an average diameter of 160 nm, which conformed to the morphological char-acteristics of microvesicles. Compared with the ische-mic stroke group, injection of microvesicles could ag-gravate the damage of brain tissues in ischemic mice, further increase the infarct volume and reduce the posi-tive staining areas of occludin and claudin-5 in ische-mia brain tissues. Meanwhile, the protein expressions of occludin and claudin-5 further decreased, and fur-ther up-regulated TLR4 and phosphorylation of NF-κB and p38 compared with the ischemia stroke group. Al-so, more content of IL-1βand TNF-αwere detected in ischemia stroke group injected with microvesicles com-pared with those in ischemia stroke group with signifi-cant difference, while the injection of antagomir-27a could alleviate brain damage and reduce the activation of TLR4, NF-κB and p38 in ischemia stroke mice. Conclusions Microvesicles containing miR-27 a could significantly attenuate brain injury in ischemia stroke mice, while aggravate the tight junction damage of ischemia brain. The mechanism might be correlated with the up-regulation of the expression of TLR4 , the phosphorylation of NF-κB, p38, and the release of cy-tokines IL-1β and TNF-α.

The protective effects and mechanisms of human umbilical cord blood mesenchymal stem cells-derived microvesicles on the injury of rat retinal ganglion cells induced by high glucose condition / 中华眼底病杂志

Objective To 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.

The protective effects of Astragaloside Ⅳ on diastolic function of rat thoracic aortic rings impaired by microvesicles / 中国应用生理学杂志

OBJECTIVES@#To investigate the effects of Astragaloside IV (AST) on diastolic function of rat thoracic aorta rings which was injured by microvesicles derived from hypoxia/reoxygenation (H/R)-treated human umbilical vein endothelial cells (HUVECs), and the mechanism of AST.@*METHODS@#H/R-induced endothelial microvesicles (H/R-EMVs) were generated from cultured HUVECs under the condition of hypoxia for 12 hour/Reoxygenation for 4 hour, H/R-EMVs were stored in D-Hank's solution. Male Wistar rats were underwent thoracotomy, the thoracic aorta with intact endothelium were carefully removed and cut into 3~4 mm rings. The experiment was divided into six groups. H/R-EMVs group:thoracic aortic rings of rats were incubated in culture medium and treated with H/R-EMVs in a final concentration of 10g/ml; different doses of AST groups:thoracic aortic rings of rats were treated with 10, 20, 40, 60 mg/L AST co-incubated with 10g/ml H/R-EMVs respectively; control group were treated with the same volume of D-Hank's solution. Duration of incubation was 4 h, each group was tested in five replicate aortic rings. Effects of AST on endothelium-dependent relaxation were detected. The production of nitric oxide (NO) and the level of endothelial NO synthase (eNOS), phosphorylated eNOS (p-eNOS, Ser-1177), serine/threonine kinase (Akt), phosphorylated Akt (p-Akt, Ser-473), extracellular regulated protein kinases (ERK1/2) and phosphorylated ERK1/2 (p-ERK1/2, Thr202/Tyr204) of rat thoracic aortic rings were detected.@*RESULTS@#Teng/ml H/R-EMVs could impaire the relaxation of rat thoracic aortic rings significantly (<0.01). Compared with H/R-EMVs group, relaxation of rat thoracic aortic rings was increased by 20, 40 and 60 mg/L AST in a concentration-dependent manner (<0.01), the level of NO production was also enhanced (<0.05, <0.01). The level of t-eNOS, t-Akt and ERK1/2 was not changed, but the level of p-eNOS, p-Akt and p-ERK1/2 increased by the treatment with AST (<0.01).@*CONCLUSIONS@#AST could effectively ameliorate endotheliumdependent relaxation of rat thoracic aortic rings impaired by H/R-EMVs in a concentration-dependent manner, the mechanism might involve the increase in production of NO, and the protein level of p-eNOS, p-Akt and p-ERK1/2.

Exosomas placentarios y preeclampsia / Placental exosomes and preeclampsia

El éxito del embarazo se asocia con una correcta placentación, esencial para el crecimiento y desarrollo del feto. El sincitiotrofoblasto en el embarazo normal produce y secreta una variedad de elementos necesarios para lograr este objetivo, entre ellos, los exosomas placentarios. Estos llevan proteínas citoplasmáticas y ligadas a la membrana y ácidos nucleicos que pueden reprogramar a las células receptoras. Dependiendo de sus interacciones con el sistema inmune pueden dividirse en inmuno-estimulantes o inmuno-supresores. La producción y secreción de exosomas placentarios inmunosupresores provoca un efecto protector en la unidad feto-placentaria. Aquellos aislados del plasma materno son activos in vitro y se incorporan a las células diana por endocitosis. Su efecto está regulado por factores que incluyen tensión de oxígeno y se correlaciona con la perfusión placentaria. La preeclampsia es un síndrome caracterizado una disminución del flujo sanguíneo útero-placentario asociado a una invasión trofoblástica alterada que puede conducir a hipoxia placentaria y disfunción endotelial, liberando materiales nocivos en la circulación, lo que ocasiona daños en la función endotelial. Se han reportado cambios en la liberación, concentración en plasma materno, composición y actividad de exosomas placentarios en asociación con la preeclampsia. En esta revisión se analiza el origen de los exosomas placentarios y cómo podrían estar involucrados en la fisiopatología de la preeclampsia.

The success of pregnancy is associated with a correct placentation that is essential for the growth and development of the fetus. In a normal pregnancy, the syncytiotrophoblast produces and secretes a variety of elements necessary to achieve this goal, among them placental exosomes. These carry cytoplasmic and membrane-bound proteins and nucleic acids that can reprogram the receptor cells. Depending on their interactions with the immune system, they can be divided into immunostimulants or immunosuppressants. The production and secretion of immunosuppressive placental exosomes causes a protective effect on the fetal­placental unit. Those isolated from maternal plasma are active in vitro and are incorporated into the target cells by endocytosis. Their effect, regulated by factors that include oxygen tension, correlates with placental perfusion. Preeclampsia is a syndrome characterized by a decrease in uteroplacental blood flow associated with an altered trophoblastic invasion that can lead to placental hypoxia and endothelial dysfunction, releasing harmful materials into the circulation and causing damage to endothelial function. Reports have associated changes in the release, concentration in maternal plasma, composition, and activity of placental exosomes with preeclampsia. In this review, we analyze the origin of placental exosomes and how they might be involved in the pathophysiology of preeclampsia.

Experimental research on the effects of different activators on the formation of platelet-rich gel and the release of bioactive substances in human platelet-rich plasma / 中华烧伤杂志

Objective@#To explore the effects of calcium gluconate and thrombin on the formation of platelet-rich gel (PRG) and the release of bioactive substances in human platelet-rich plasma (PRP) and the clinical significance.@*Methods@#Six healthy blood donors who met the inclusion criteria were recruited in our unit from May to August in 2016. Platelet samples of each donor were collected for preparation of PRP. (1) PRP in the volume of 10 mL was collected from each donor and divided into thrombin activation group (TA, added with 0.5 mL thrombin solution in dose of 100 U/mL) and calcium gluconate activation group (CGA, added with 0.5 mL calcium gluconate solution in dose of 100 g/L) according to the random number table, with 5 mL PRP in each group. Then the PRP of the two groups was activated in water bath at 37 ℃ for 1 h. The formation time of PRG was recorded, and the formation situation of PRG was observed within 1 hour of activation. After being activated for 1 h, one part of PRG was collected to observe the distribution of fibrous protein with HE staining, and another part of PRG was collected to observe platelet ultrastructure under transmission electron microscope (TEM). After being activated for 1 h, the supernatant was collected to determine the content of transforming growth factor β1, platelet-derived growth factor BB (PDGF-BB), vascular endothelial growth factor, basic fibroblast growth factor (bFGF), epidermal growth factor, and insulin-like growth factorⅠby enzyme-linked immunosorbent assay. (2) Another 10 mL PRP from each donor was collected and grouped as above, and the platelet suspension was obtained after two times of centrifugation and resuspension with phosphate buffered saline, respectively. And then they were treated with corresponding activator for 1 h as that in experiment (1). Nanoparticle tracking analyzer was used to detect the concentrations of microvesicles with different diameters and total microvesicles derived from platelet. Data were processed with t test.@*Results@#(1) The formation time of PRG in group TA was (228±40) s, and the PRG volume reached the maximum at this moment. The PRG volume shrunk to the minimum after 30 minutes of activation. The formation time of PRG in group CGA was (690±71) s, and the PRG volume reached the maximum at this moment. After 55 minutes of activation, the PRG volume shrunk to the minimum. The formation time of PRG in group TA was obviously shorter than that in group CGA (t=15.17, P<0.01). (2) HE staining showed that after 1 hour of activation, the red-stained area of fibrous protein in PRG of group TA was large and densely distributed, while that of group CGA was small and loosely distributed. TEM revealed that after 1 hour of activation, the platelets in PRG of group TA were fragmented, while lysing platelet structure, lysing α granule structure, intact α granule structure, and intact dense body structure were observed in PRG of group CGA. (3) The content of PDGF-BB released by PRP in group TA was (7.4±0.8) ng/mL, which was obviously higher than that in group CGA [(4.9±0.5) ng/mL, t=5.41, P<0.01]. The content of bFGF released by PRP in group CGA was (960±151) pg/mL, which was significantly higher than that in group TA [(384±56) pg/mL, t=8.75, P<0.01]. The content of the other 4 growth factors released by PRP in the two groups was close (with t values from 0.11 to 1.97, P values above 0.05). (4) The concentrations of total microvesicles, microvesicles with diameter more than 100 nm, and exosomes with diameter less than or equal to 100 nm derived from platelet in group CGA were (165.8±15.1)×108/mL, (142.4±12.3)×108/mL, and (23.4±2.9)×108/mL respectively, which were significantly higher than those in group TA [(24.7±4.6)×108/mL, (22.6±4.0)×108/mL, and (2.1±0.7)×108/mL, with t values from 17.36 to 22.66, P values below 0.01].@*Conclusions@#Calcium gluconate can slowly activate PRP, resulting in slowly shrunk PRG with high content of bFGF and high concentration of microvesicles, which is suitable for repairing articular cavity and sinus tract wound. Thrombin can rapidly activate PRP, resulting in quickly shrunk PRG with high content of PDGF-BB and a certain concentration of microvesicles, which is suitable for repairing acute trauma.

Interferon-γ Alters the Immune-related miRNA Expression of Microvesicles Derived from Mesenchymal Stem Cells / 华中科技大学学报（医学）（英德文版）

Increasing studies have demonstrated that interferon gamma (IFN-γ),which serves as a critical inflammatory cytokine,is essential to induce the immunosuppressive effects of mesenchymal stem cells (MSCs).However,the mechanisms underlying the enhanced immunosuppressive effects of IFN-γ-stimulated MSCs (γMSCs) are not fully understood.MSC-derived rnicrovesicles (MSC-MVs) have been viewed as potential pivotal mediators of the immunosuppressive effects of MSCs.Moreover,microRNAs (miRNAs) are important regulators of immunological processes and can be shuttled from cell to cell by MVs.The aim of our study was to analyze the the miRNA expression signature of MVs derived from γMSCs (γMSC-MVs),which may provide better understanding of the immunosuppressive property of their parent cells.Through miRNA microarray and bioinformatics analysis,we found 62 significantly differentially expressed miRNAs (DEMs) in γMSC-MVs compared with MSC-MVs.And the potential target genes and signaling pathways regulated by DEMs were predicted and analyzed.Interestingly,many DEMs and predicted signaling pathways had been.demonstrated to be involved in immunoregulation.Furthermore,the network between immunoregulation-related pathways and relevant DEMs was constructed.Collectively,our research on the miRNA repertoires of γMSC-MVs not only provides new perspectives into the mechanisms underlying the enhanced immunosuppressive property of γMSCs,but also paves the way to clinical application of these potent organelles in the future.

Histological Evaluation of Experimentally Induced Critical Size Defect Skin Wounds Using Exosomal Solution of Mesenchymal Stem Cells Derived Microvesicles

BACKGROUND AND OBJECTIVES: The present study investigated whether MSCs derived microvesicles (MVs) or (Exosomes) can exert therapeutic effects on an experimental model of cutaneous injury and explored the underlying involving mechanisms. METHODS AND RESULTS: Three bilateral full thickness circular wounds were created on the back of two groups of dogs using 2-cm dermal punch. The wounds were at least 2.5 cm apart. Saline was subcutaneously injected in 4 places around each wound area in group-I (control), whereas an equal volume of exosomal solution of MSCs derived MVs was similarly injected in group-II. The findings demonstrated that MSCs derived MVs had significantly promoted cutaneous wound healing, collagen synthesis, and vascularization at wound sites. The application of the exosomal solution had not only promoted the generation of newly formed vessels, but also have accelerated their development and maturation leading to a faster healing process. CONCLUSIONS: MSC-Exosomes appeared to be a superior candidate for treating cutaneous wounds than their originator cells, and may represent a promising opportunity to develop a novel cell-free therapy approach that might overcome the obstacles and risks associated with the use of native or engineered stem cells transplantation therapy.

Hypothesis and development of tumor pre-metastatic nich / 国际外科学杂志

Tumor invasion and metastasis are regarded as main reasons for the failure of therpy and the reason of patients death.The mechnism of tumor metastasis is still uncertain.The pre-metastatic niche hypothesis provides us with new ideas to discover the mechnism.Numerous materials are involved in the formation of the pre-metastatic niche according to this hypothesis,including bone marrow-derived cells,microvesicles,exosomes,CD44,and so on.A further research on this hypothesis helps to deeply understand the nature of metastasis and leads clinical doctors to explore novel targets for clinical diagnoses and therapies.

Preparation and process optimization of HCPT-loaded PLGA microvesicles by ultrasound / 第三军医大学学报

Objective To investigate the effects of different technical conditions on the microvesicle size,envelopment rate,morphology of surface and so on in order to select the best technical conditions to prepare HCPT(10-hydroxy-camptothecin)-loaded PLGA microvesicles.Methods Microvesicles were prepared by a water/oil/water emulsion and solvent evaporation method.Various factors related to the envelopment rate and micmparticle size were studied,such as the ratio of water phase and oil phase,ultrasound power,and time,stirring time and so on.Single factor experiments and orthogonal design testing was carried out to optimize the technology of microvesicles preparation.Results The best processing conditions for microvesicles preparation were as following: HCPT 25 mg,PLGA 1.875 g,the ratio of internal and external phases 1∶15,and the PVA concentration 3%.These preparative variables produced global,smooth and glossy microvesicles.Electric charges were probably between-40 to 0 mV,microvesicles sizes ranged from 500 to 1 000 nm,envelopment rate was 79.33%,drug loading to the microvesicles was 0.478 3%,and ultrasonic imaging was clear in vitro.Conclusion Our optimize technical conditions can prepare injectable microvesicles by ultrasound.