Function Of Exosomes Research Articles

Abstract 249: Plasma Exosomes Impair Angiogenesis in Ischemic Hind Limb of Diabetic Mice- Role of Histone Methylation

Background: Critical limb ischemia (CLI) is one of most prevenient cardiovascular disease in diabetic patients. Recent evidence suggests that altered cargo and function of plasma exosomes (plasma-Exo) may play an important role in diabetes-induced cardiovascular complications. Here, we tested the hypotheses that inhibition of exosome biosynthesis/release improves ischemic hind limb (IHL) repair in db/db mice. Methods: Plasma-Exo from db/+ and db/db mice were isolated by density-gradient ultracentrifugation. Unilateral IHL in mice was conducted by ligation of left femoral artery. Blood perfusion in IHL was measured by Laser Doppler Imager. Results: Diabetic plasma-Exo impaired tube formation/migration of human microvascular endothelial cells (HMVECs) and blood perfusion in IHL of C57BL/6J mice. Exosome inhibitor GW4869 improved blood flow, capillary density, cell survival, and rescued necrosis of toe/toenail and fibrosis in IHL muscle of db/db mice. Mechanistically, diabetic plasma-Exo decreased secretion of pro-angiogenic factor Ang I&II, artemin, FGF2 and IGFBP1&2, and increased repressive transcriptional mark H3K27me3 and its methylase enhancer of zest homolog-2 (EZH2) in HMVECs. EZH2 inhibitor GSK343 rescued diabetic plasma-Exo-impaired tube formation and secretion of FGF2/artemin from HMVECs. Moreover, GW4869 reduced EZH2 and H3K27me3 protein expression in lung microvascular ECs of IHL db/db mice. Finally, diabetic plasma-Exo increased H3K27me3 level at promoter of artemin and FGF2. Conclusions: Diabetic plasma-Exo impair angiogenesis and IHL injury repair. Diabetic plasma-Exo impair reparative property of ECs via, at least in part, enhancement of EZH2/H3K27me3/artemin and FGF2 cascade. Inhibition of plasma-Exo biosynthesis/secretion improve IHL repair in db/db mice. Plasma-Exo may be a novel target for prevention/treatment of CLI in diabetic patients.

Abstract 272: Epigenetic Regulation Involved in Diabetes-induced Impairment in Myocardial Reparative Function of Endothelial Progenitor Cell-derived Exosomes

Myocardial infarction (MI) occurs frequently in patients with diabetes resulting in higher mortality and morbidity than non-diabetic patients. We and others have shown that bone marrow-derived endothelial progenitor cells (EPCs) promote cardiac neovascularization and attenuate ischemic injury in animal models. Moreover, emerging evidence supports that exosomes (Exo) mediate stem cell therapy by carrying cell-specific biological signatures and by inducing signaling via transfer of bioactive molecules to target cells. However, autologous cell-based therapies yielded modest clinical results, suggesting that cellular/Exo reparative function may be compromised on a background of disease such as diabetes. In addition, recent studies suggest epigenetic mechanisms, such as histone methylation for gene silencing, promotes diabetes-induced vascular complication. Therefore, we hypothesized that diabetic EPCs produce exosomes of altered and dysfunctional content which compromise EPC reparative function in ischemic heart disease via epigenetic alterations. We collected EPC-Exo from non-diabetic mice (Lepr db/+ ) and diabetic mice (Lepr db/db ) and examined their effect on tube formation and cardiomyocyte/endothelial cell survival in vitro as well as their reparative effects on permanent and acute ischemia/reperfusion (I/R) myocardial ischemic injuries in vivo . Diabetic EPC-Exo promoted neonatal rat cardiomyocyte cell apoptosis under hypoxic stress and repressed endothelial tube formation and cell survival compared to cells treated with WT EPC-Exo. In vivo studies revealed diabetic EPC-Exo significantly attenuated cardiac function, reduced capillary density, increased fibrosis and infarct size in permanent LAD ligation and I/R MI models. Mechanistically,H3K9Me3 was increased in mouse cardiac endothelial cells treated with diabetic EPC-exo, suggesting inhibition of angiogenic genes. Our results provide evidence that diabetic EPC-derived exosomes lose their cardiac reparative activities. Specific angiogenic genes will be examined by CHIP analysis of H3K9Me3. Reversing EPC-Exo function by manipulating H3K9Me3 expression will augment autologous therapies in regenerative medicine.

FcεRI Signaling in the Modulation of Allergic Response: Role of Mast Cell-Derived Exosomes.

Mast cells (MCs) are immune cells that act as environment resident sentinels playing a crucial role in Th2-mediated immune responses, including allergic reactions. Distinguishing features of MCs are the presence of numerous cytoplasmic granules that encapsulate a wide array of preformed bio-active molecules and the constitutive expression of the high affinity receptor of IgE (FcεRI). Upon FcεRI engagement by means of IgE and multivalent antigens, aggregated receptors trigger biochemical pathways that ultimately lead to the release of granule-stored and newly synthesized pro-inflammatory mediators. Additionally, MCs are also able to release exosomes either constitutively or upon stimulation. Exosomes are nanosized vesicles of endocytic origin endowed with important immunoregulatory properties, and represent an additional way of intercellular communication. Interestingly, exosomes generated upon FcεRI engagement contain co-stimulatory and adhesion molecules, lipid mediators, and MC-specific proteases, as well as receptor subunits together with IgE and antigens. These findings support the notion that FcεRI signaling plays an important role in influencing the composition and functions of exosomes derived by MCs depending on their activation status.

Exosome-based Tumor Therapy: Opportunities and Challenges.

Exosomes play an important role in transferring information among different cell types, as they transport materials from the cell membrane to the cytoplasm. They are involved not only in normal physiological functions, but also in the occurrence and development of a variety of diseases. Cancer is a major health problem affecting humans. Currently, exosomes are considered novel stars in tumor therapy. To present a review focusing on the role of exosomes in tumorigenesis and development and the possibility of treating tumors with exosome-targeted therapies or using exosomes as carriers. We reviewed literature related to the biological origin and function of exosomes and exosome-tumor relationship. Exosomes are closely related to tumor immunity, angiogenesis, pre-metastasis microenvironment, chemoresistance, energy metabolism, etc. Tumor therapy involving the targeting of exosomes involves block the generation, secretion, uptake of exosomes, and elimination of circulating exosomes, and develop antitumor vaccines. Exosome as delivery vehicles can be loaded with chemotherapeutic drugs, therapeutic genes, and other therapeutic drugs to target cells. Prospects and challenges of exosome-based tumor therapy are also discussed. Exosomes are involved in multiple processes during tumor development and should be further studied as novel targets for cancer therapy.

Glutamine deprivation alters the origin and function of cancer cell exosomes

Exosomes are secreted extracellular vesicles carrying diverse molecular cargos, which can modulate recipient cell behaviour. They are thought to derive from intraluminal vesicles formed in late endosomal multivesicular bodies (MVBs). An alternate exosome formation mechanism, which is conserved from fly to human, is described here, with exosomes carrying unique cargos, including the GTPase Rab11, generated in Rab11‐positive recycling endosomal MVBs. Release of Rab11‐positive exosomes from cancer cells is increased relative to late endosomal exosomes by reducing growth regulatory Akt/mechanistic Target of Rapamycin Complex 1 (mTORC1) signalling or depleting the key metabolic substrate glutamine, which diverts membrane flux through recycling endosomes. Vesicles produced under these conditions promote tumour cell proliferation and turnover and modulate blood vessel networks in xenograft mouse models in vivo. Their growth‐promoting activity, which is also observed in vitro, is Rab11a‐dependent, involves ERK‐MAPK‐signalling and is inhibited by antibodies against amphiregulin, an EGFR ligand concentrated on these vesicles. Therefore, glutamine depletion or mTORC1 inhibition stimulates release from Rab11a compartments of exosomes with pro‐tumorigenic functions, which we propose promote stress‐induced tumour adaptation.

Role of Circular Ribonucleic Acids in the Treatment of Traumatic Brain and Spinal Cord Injury.

The causal and pathogenetic factors linked to traumatic brain injury (TBI) and spinal cord injury (SCI) are complex. This complexity is a contributive factor in the minimal improvement outcomes of injured individuals. Several studies have demonstrated the potentiality of stem cells in facilitating neuronal growth and improve outcome in various neurological conditions, including TBI and SCI. However, the efficiency concerning stem cell delivery at injured sites is open to question. Circular ribonucleic acids (circular RNAs) have recently been the focus of attention owing to their disparate functions and features in vivo. Exosomes have close relationship with circular RNAs and might have a significant impact on circular RNA expressions. Herein, we reviewed the specific functions of circular RNAs, exosomes, and stem cells in central nervous system conditions, particularly TBI and SCI, and attempted to show the connection among them. Our analyses showed the role of circular RNAs in brain/spinal cord injuries to be multifaceted, as they can modulate several signaling mechanisms while also acting as sponges for microRNAs and binding to their sites. Additionally, circular RNAs can activate several biological, molecular, and cellular activities in the wake of brain/spinal cord injuries. Thus, both non-pharmacological and pharmacological interventions centered on the regulation of circular RNAs could be promising for TBI and SCI.

The role of exosome lipids in central nervous system diseases.

Central nervous system (CNS) diseases are common diseases that threaten human health. The CNS is highly enriched in lipids, which play important roles in maintaining normal physiological functions of the nervous system. Moreover, many CNS diseases are closely associated with abnormal lipid metabolism. Exosomes are a subtype of extracellular vesicles (EVs) secreted from multivesicular bodies (MVBs) . Through novel forms of intercellular communication, exosomes secreted by brain cells can mediate inter-neuronal signaling and play important roles in the pathogenesis of CNS diseases. Lipids are essential components of exosomes, with cholesterol and sphingolipid as representative constituents of its bilayer membrane. In the CNS, lipids are closely related to the formation and function of exosomes. Their dysregulation causes abnormalities in exosomes, which may, in turn, lead to dysfunctions in inter-neuronal communication and promote diseases. Therefore, the role of lipids in the treatment of neurological diseases through exosomes has received increasing attention. The aim of this review is to discuss the relationship between lipids and exosomes and their roles in CNS diseases.

Effect of mastitis on the function of milk-derived exosomes: observations from mammary epithelial cells

Effect of mastitis on the function of milk-derived exosomes: observations from mammary epithelial cells

Osteocyte-derived exosomes induced by mechanical strain promote human periodontal ligament stem cell proliferation and osteogenic differentiation via the miR-181b-5p/PTEN/AKT signaling pathway

BackgroundThe oral cavity is a complex environment in which periodontal tissue is constantly stimulated by external microorganisms and mechanical forces. Proper mechanical force helps maintain periodontal tissue homeostasis, and improper inflammatory response can break the balance. Periodontal ligament (PDL) cells play crucial roles in responding to these challenges and maintaining the homeostasis of periodontal tissue. However, the mechanisms underlying PDL cell property changes induced by inflammatory and mechanical force microenvironments are still unclear. Recent studies have shown that exosomes function as a means of cell-cell and cell-matrix communication in biological processes.MethodsHuman periodontal ligament stem cells (HPDLSCs) were tested by the CCK8 assay, EdU, alizarin red, and ALP staining to evaluate the functions of exosomes induced by a mechanical strain. MicroRNA sequencing was used to find the discrepancy miRNA in exosomes. In addition, real-time PCR, FISH, luciferase reporter assay, and western blotting assay were used to investigate the mechanism of miR-181b-5p regulating proliferation and osteogenic differentiation through the PTEN/AKT pathway.ResultsIn this study, the exosomes secreted by MLO-Y4 cells exposed to mechanical strain (Exosome-MS) contributed to HPDLSC proliferation and osteogenic differentiation. High-throughput miRNA sequencing showed that miR181b-5p was upregulated in Exosome-MS compared to the exosomes derived from MLO-Y4 cells lacking mechanical strain. The luciferase reporter assay demonstrated that miR-181b-5p may target phosphatase tension homolog deletion (PTEN). In addition, PTEN was negatively regulated by overexpressing miR-181b-5p. Real-time PCR and western blotting assay verified that miR-181b-5p enhanced the protein kinase B (PKB, also known as AKT) activity and improved downstream factor transcription. Furthermore, miR-181b-5p effectively ameliorated the inhibition of HPDLSC proliferation and promoted HPDLSC induced by inflammation.ConclusionsThis study concluded that exosomes induced by mechanical strain promote HPDLSC proliferation via the miR-181b-5p/PTEN/AKT signaling pathway and promote HPDLSC osteogenic differentiation by BMP2/Runx2, suggesting a potential mechanism for maintaining periodontal homeostasis.

Salivary exosomes: properties, medical applications, and isolation methods.

Salivary exosomes are extracellular vesicles (EVs) with abundant CD63 immunoreactivity on their surface. Based on their size and protein composition, these exosomes can be categorized into two classes of exosomes I (mean diameter of 83.5nm) and II (mean diameter of 40.5nm). We have attempted to review the features of these exosomes, including origin, composition, separation methods, and their application in medicine. Not only the composition of salivary exosomes is invaluable in term of diagnosis, but can also afford an understanding in roles of the contents and components of these exosomes in the fundamental pathophysiologic processes of different diseases. since these EVs can cross the epithelial barriers they may be essential for transporting of multifarious components from the blood into saliva. Thus, in comparison to other bodily fluids, salivary exosomes are probably a better and accessible tool to examine the function of exosomes in the diagnosis and treatment of disease.

Cow milk exosomes activate NK cells and γδT cells in human PBMCs in vitro

Cow milk is a nourishing food containing numerous essential nutrients. In Japan, the consumption of cow milk is thought to enhance resistance to exhaustion-related diseases. Although several nutrients in cow milk, such as lactoferrin, are thought to modulate immune cells, the mechanisms remain unclear. Recently, the immunoregulatory functions of food-derived microRNAs or exosomes have been reported. Therefore, we studied the effects of exosomes derived from cow milk (CM-Exs) on immune cells in the present study. We obtained blood samples from healthy adult donors with the approval of the ethics committee. Peripheral blood mononuclear cells (PBMCs) were stimulated with CM-Exs in the absence or presence of interleukin-2 (IL-2) and IL-12. Cell surface markers and intracellular cytokine production were analysed by flow cytometry. CM-Ex stimulation enhanced the expression of CD69 on NK cells. Although CM-Ex stimulation alone did not induce interferon-γ (IFN-γ) production by NK cells or γδT cells, simultaneous stimulation with CM-Ex, IL-2 and IL-12 significantly enhanced IFN-γ production. In conclusion, cow milk consumption alone may not activate immune cells; however, CM-Exs could enhance immune cells under inflammatory conditions.

Protective Role of Astrocyte-Derived Exosomal microRNA-361 in Cerebral Ischemic-Reperfusion Injury by Regulating the AMPK/mTOR Signaling Pathway and Targeting CTSB.

BackgroundEvidence has shown that microRNAs (miRNAs) are implicated in ischemic diseases. Therefore, the aim of the present study was to identify the functions of astrocyte (ATC)-derived exosomal miR-361 on cerebral ischemic-reperfusion (I/R) injury.MethodsA rat model of cerebral I/R injury was initially established, followed by injection of ATC-derived exosomes. Next, the protective function of ATC-derived exosomes in rats with cerebral I/R injury was evaluated, and then the effect of miR-361 on rats with cerebral I/R injury was evaluated by changing miR-361 expression in exosomes. PC12 cells that underwent oxygen-glucose deprivation/reoxygenation were used to simulate I/R in vitro. The effect of ATC-derived exosomal miR-361 on the viability and apoptosis of OGD/R-treated PC12 cells was also assessed. The bioinformatic analysis predicted the targeted gene of miR-361.ResultsIt was found that I/R was damaging to the brain nerves of rats, while ATC-derived exosomal miR-361 relieved nerve damage caused by I/R. Furthermore, the in vitro experiments demonstrated that ATC-derived exosomal miR-361 increased OGD/R-inhibited PC12 cell activity and suppressed cell apoptosis. Bioinformatics predicted that miR-361 targeted cathepsin B (CTSB). CTSB upregulation blocked the protective roles of miR-361. In addition, miR-361 was found to downregulate the AMPK/mTOR signaling pathway by targeting CTSB.ConclusionThe present study demonstrated that ATC-derived exosomal miR-361 alleviates nerve damage in rats with cerebral I/R injury by targeting CTSB and downregulating the AMPK/mTOR pathway. This may offer novel insights into treatment for I/R injury.

Exosomes derived from chemically induced human hepatic progenitors inhibit oxidative stress induced cell death

The emerging field of regenerative medicine has revealed that the exosome contributes to many aspects of development and disease through intercellular communication between donor and recipient cells. However, the biological functions of exosomes secreted from cells have remained largely unexplored. Here, we report that the human hepatic progenitor cells (CdHs)‐derived exosome (EXOhCdHs) plays a crucial role in maintaining cell viability. The inhibition of exosome secretion treatment with GW4869 results in the acceleration of reactive oxygen species (ROS) production, thereby causing a decrease of cell viability. This event provokes inhibition of caspase dependent cell death signaling, leading to a ROS‐dependent cell damage response and thus induces promotion of antioxidant gene expression or repair of cell death of hypoxia‐exposed cells. Together, these findings show the effect of exosomes in regeneration of liver cells, and offer valuable new insights into liver regeneration.

MSC-derived exosomal miR-34a/c-5p and miR-29b-3p improve intestinal barrier function by targeting the Snail/Claudins signaling pathway

AimsMesenchymal stem cell (MSC)-derived exosomes (MSCs-exos) regulate biological functions in different diseases, such as liver fibrosis, diabetes, and ischaemic heart injury. However, the function of MSC-derived exosomes on the intestinal barrier and the underlying mechanisms are poorly characterized. Main methodsThe expression of miR-34a/c-5p, miR-29b-3p and Claudin-3 in human normal intestinal tissues and damaged intestinal tissues was evaluated by RT-qPCR. The effect of MSC-secreted exosomes on Claudins in Caco-2 cells was measured by using confocal microscopy, RT-qPCR and Western blot. Dual luciferase reporter assays and RNA immunoprecipitation (RIP) assays were performed to study the interaction between miR-34a/c-5p, miR-29b-3p and Snail. I/R-induced intestinal damage in rats was used to determine the in vivo effect of MSC-exos on intestinal barrier function. Key findingsIn this study, we found that miR-34a/c-5p, miR-29b-3p and Claudin-3 were downregulated in damaged human intestinal tissues. MSC-exos increased the expression of Claudin-3, Claudin-2 and ZO-1 in Caco-2 cells. Further studies demonstrated that MSC-exos promoted Claudin-3, Claudin-2 and ZO-1 expression in Caco-2 cells by Snail, which was targeted by miR-34a/c-5p and miR-29b-3p. In vivo experiments showed that MSC-derived exosomes could improve I/R-induced intestinal damage through the Snail/Claudins signaling pathway. SignificanceThe findings here suggest a novel molecular basis for the therapy of intestinal barrier dysfunction.

Biogenesis, Biologic Function and Clinical Potential of Exosomes in Different Diseases

Exosomes are extracellular vesicles (EVs) belonging to the nanovesicles family that function as signaling molecules between cells. After their first description in the late 1960s, interest in their potential as a research target has steadily increased. They are small secreted organelles with a single membrane that are well enriched in lipids, proteins, nucleic acids, and glycoconjugates. Exosomes take part in a larger communication network in which cells communicate between one another by DNA shuttling, proteins, RNA, and membrane-bound factors. The machinery of protein quality control occurs through the process termed “exosome biogenesis”. Furthermore, the pathway involved in intercellular movement of vesicles is vital in various aspects of human health and diseases. Due to their inherent properties, exosomes are currently being developed as potential therapeutic agents in a wide range of diseases including infectious and non-infectious diseases. Exosomes and other EVs sourced from Mesenchymal stem cells (MSCs) have been shown in different studies to possess therapeutic effects in diverse disease models either in vivo or in vitro. Some mechanisms and/or pathways that MSC-derived exosomes use to illustrate their therapeutic effect against some diseases have also been summarized. This review aims to highlight the recent findings and potential therapeutic application of exosomes in different diseases such as autoimmune, cardiovascular, obesity, neural, soft tissues, bone, and cartilage.

Exosomal release of microRNA-454 by breast cancer cells sustains biological properties of cancer stem cells via the PRRT2/Wnt axis in ovarian cancer

AimsCancer-derived exosomes carrying tumor-derived molecules such as miRNAs and proteins related to various phenotypes have been detected in both the bloodstream and other biofluids of patients with different cancers. Thus, our main purpose here was to determine the role of the exosomal microRNA-454 (miR-454) derived by MDA-MB-231 in self-renewal of cancer stem cells (CSCs) in ovarian cancer (OC). Materials and methodsExtraction of MDA-MB-231 cells-derived exosomes (231-derived exosomes) was conducted to treat CD44+/CD133+ SKOV3 and CoC1 cells to observe cell growth and stemness. Next, the differentially expressed miRNAs in SKOV3 cells after exosome treatment were filtered using microarray analysis. Subsequently, the cell viability was detected after reducing the exosomal miR-454 and the addition of a Wnt pathway inhibitor C59. Finally, the pro-tumorigenic function of exosomes on OC cells in vivo was investigated. Key findingsAfter co-culture with 231-derived exosomes, the stemness of CSCs were promoted. Subsequently, the reduction of exosomal miR-454 weakened the roles of exosomes on cell stemness. Proline-rich transmembrane protein 2 (PRRT2) was substantiated as a target gene of miR-454 in SKOV3 and CoC1 cells. C59 reversed the repressive role of exosomes in stemness of CSCs. When being evaluated in a mouse model, exosomal miR-454 led to an efficacious effect in suppressing the tumor weight and volume in vivo. SignificanceAltogether, 231-derived exosomes carrying miR-454 disrupted the Wnt pathway by targeting PRRT2, thereby promoting CSC stemness in vitro and OC cell growth in vivo.

Pancreatic stellate cells derived exosomal miR-5703 promotes pancreatic cancer by downregulating CMTM4 and activating PI3K/Akt pathway.

Exosomes play important role in tumor microenvironment, and mediate the crosstalk between pancreatic cancer (PC) cells and matrix components including pancreatic stellate cells (PSCs) to regulate pancreatic cancer progression. Here we isolated primary PSCs from PC patients, and demonstrated that PSC-derived exosomes could be internalized by PC cells to promote cell proliferation. Furthermore, we identified that miR-5703 in the exosomes acted as a driver of cell proliferation and its inhibitor suppressed the function of exosomes to promote PC cell proliferation. miR-5703 directly bound to the 3'UTR of CMTM4 and downregulated its expression. CMTM4 knockdown promoted PC cell proliferation, while overexpression of CMTM4 suppressed PC cell proliferation both in vivo and in vitro. Mechanistically, we revealed that CMTM4 suppressed PI3K/Akt pathway via downregulating PAK4. In conclusion, our results suggest that PSC-derived exosomal miR-5703 could target CMTM4 in PC cells and promote cell proliferation due to PAK4 activated PI3K/Akt pathway.

Exosomes as Messengers Between Mother and Fetus in Pregnancy.

The ability of exosomes to transport different molecular cargoes and their ability to influence various physiological factors is already well known. An exciting area of research explores the functions of exosomes in healthy and pathological pregnancies. Placenta-derived exosomes were identified in the maternal circulation during pregnancy and their contribution in the crosstalk between mother and fetus are now starting to become defined. In this review, we will try to summarize actual knowledge about this topic and to answer the question of how important exosomes are for a healthy pregnancy.

P0970EXOSOMAL MIR-92A-1-5P DERIVED FROM PROXIMAL TUBULAR EPITHELIAL CELLS INDUCES EPITHELIAL-MESENCHYMAL TRANSITION IN MESANGIAL CELLS IN DIABETIC NEPHROPATHY

Abstract Background and Aims Diabetic nephropathy (DN) has been the leading cause of end-stage renal disease in the world-wide. Exosomes play a key role in signal transduction between cell-cell communication in kidney pathophysiology. The aim of this study is to investigate that HK-2 cells-derived exosomal miR-92a-1-5p causes epithelial-mesenchymal transition (EMT) in mesangial cells (MCs), further leading to DN progression. Method The function of HK-2 cells-derived exosomes under normal glucose (NG) and high glucose (HG) was analyzed in mouse MCs model. Total RNAs were extracted from renal proximal tubular epithelial cells (RPTECs) of normal individual and type 2 diabetes for small RNA expression profiling using next-generation sequencing (NGS), then analyzed using systematic bioinformatics analyses. The expression of miR-92a-1-5p was examined in HK-2 cells-derived exosomes and MCs treated with HK-2 cells-derived exosomes under HG. The role of miR-92a-1-5p in EMT was evaluated using MCs model under NG and HG conditions. Urinary exosomal miR-92a-1-5p levels were measured in 50 type 2 diabetic patients and 34 healthy volunteers who were enrolled to determine the relationship between urinary exosomal miR-92a-1-5p and kidney function. Results Decreased E-cadherin, and increased N-cadherin and Vimentin expression were found in mouse MCs treated with HK-2 cells-derived exosomes under HG. Transcriptome analysis of RPTECs of normal individual and type 2 diabetic patient indicated that miR-92a-1-5p contributes to HG-induced renal proliferation. HG elevated miR-92a-1-5p expression in HK-2 cells and exosomes derived from-HK-2 cells, at meanwhile exosomal miR-92a-1-5p derived from-HK-2 cells under HG leads to EMT in mouse MCs. miR-92a-1-5p mimic increased EMT in mouse MCs under NG, and miR-92a-1-5p inhibitor reversed EMT in mouse MCs induced by exosomes derived from HK-2 cells under HG. EMT of mouse MCs was enhanced in the presence of exosomes isolated from the urine of type 2 diabetic patients with high levels of exosomal miR-92a-1-5p. Type 2 diabetic patients had higher urinary exosomal miR-92a-1-5p levels than normal individuals. Higher urinary exosomal miR-92a-1-5p levels were significantly correlated with lower renal function and higher albuminuria in human model. Conclusion Exosomal miR-92a-1-5p derived from HK-2 cells under HG induces EMT in mesangial cells. Blocking miR-92a-1-5p epigenetic regulatory network might be a potential therapeutic strategy to prevent EMT in DN.

Exosome-mediated miR-106a-3p derived from ox-LDL exposed macrophages accelerated cell proliferation and repressed cell apoptosis of human vascular smooth muscle cells.

Atherosclerosis (AS) is a leading disease with high mortality and morbidity in the world. It has been demonstrated that exosomes can transfer some miRNAs or proteins to regulate the biological functions of human vascular smooth muscle cells (VSMCs) and promote the progression of AS. In this study, we mainly aimed at exploring potential functions of exosomes derived from ox-LDL exposed macrophages and investigating the potential mechanisms of exosome-mediated miR-106a-3p in regulating VSMCs and promoting AS. Ox-LDL was used to treat THP-1 macrophages, CCK-8 assay was performed to detect cell viability, and flow cytometric analysis was used to detect cell apoptosis. Exosomes were isolated and collected with centrifugation, and were determined by transmission electron microscopy and WB assay. RT-PCR was used to detect the expressions of miRNAs in exosomes and VSMCs, WB assay was used to detect protein expressions. MiR-106a-3p mimic was transfected into VSMCs to verify its functions and the Luciferase gene reporter assay was performed to prove the binding site of miR-106a-3p and CASP9. Finally, GW4869, an inhibitor for exosome secretion, was used to block exosome secretion by ox-LDL induced THP-1 and to confirm the effects of miR-106a-3p on cell proliferation and apoptosis in VSMCs. We found that ox-LDL induced THP-1 could promote cell proliferation and repress cell apoptosis of VSMCs, then, exosomes were successfully isolated, which could promote cell proliferation and repressed cell apoptosis of VSMCs after adding into VSMCs. Furthermore, we found that miR-106a-3p was significantly increased in exosomes from ox-LDL induced THP-1 and its expression was also increased in VSMCs after adding into VSMCs. Moreover, miR-106a-3p overexpression could promote cell viability and repress cell apoptosis, as well as regulate associated protein expressions. Additionally, the Luciferase gene reporter assay confirmed that miR-106a-3p could directly bind with CASP9 and regulate Caspase signaling in VSMCs. Finally, blocking exosomes from ox-LDL induced THP-1 reduced the cell viability and promoted cell apoptosis in VSMCs. Above all, this study demonstrated that miR-106a-3p was increased in exosomes from ox-LDL induced THP-1 and it could promote cell proliferation and repress cell apoptosis of VSMCs. We found that the exosomes-mediated miR-106a-3p could directly bind with CASP9 and repress Caspase signaling pathway in VSMCs, which might provide a potential target for treating AS.