肝细胞癌患者血清外泌体microRNA表达鉴定

目的:探讨肝癌细胞外泌体中差异表达的microRNAs(miRNAs)在肝细胞癌(HCC)诊断中的应用价值。方法:通过高通量测序筛选肝癌细胞外泌体中差异表达的miRNAs。实时定量PCR验证差异表达分子;检测差异表达的miRNAs在健康人(Health)、慢性乙型肝炎患者(CHB)、肝硬化患者(LC)及乙型肝炎病毒阳性的肝细胞癌患者(HCC)血清外泌体中的表达。结果:高通量测序筛选到肝癌细胞外泌体中差异表达的miRNA共88种,其中58种表达上调,30种表达下调。选择其中8种差异表达的miRNAs进行q RT-PCR验证,结果显示,此8种miRNAs在细胞上清外泌体、细胞内、癌与癌旁组织中的表达趋势与测序结果一致。miR-221-3p和miR-224-5p在HCC组外泌体中的表达水平显著高于Health组、CHB组和LC组(P0.01),miR-124-3p和let-7a-5p在HCC组外泌体中的表达水平显著低于其他各组(P0.05)。四个组中,miR-21-5p、miR-191-5p、miR-34a-5p和miR-122-5p的表达水平不存在显著性差异(P0.05)。结论:血清外泌体中的miR-221-3p、miR-224-5p、miR-124-3p和let-7a-5p可能成为肝细胞癌的候选标志物。     

G-MDSC-derived exosomes attenuate collagen-induced arthritis by impairing Th1 and Th17 cell responses

The therapeutic effect of myeloid-derived suppressor cells (MDSCs) in mice with collagen-induced arthritis (CIA) remains controversial. We analyzed the role of exosomes derived from granulocytic MDSCs (G-MDSCs) in CIA and explored the potential mechanism underlying the immunosuppressive effect. In CIA mice, G-MDSC-derived exosomes (G-exo) efficiently reduced the mean arthritis index, leukocyte infiltration and joint destruction. G-exo decreased the percentages of Th1 and Th17 cells both in vivo and in vitro. The miR-29a-3p and miR-93-5p contained in G-exo were verified to inhibit Th1 and Th17 cell differentiation by targeting T-bet and STAT3, respectively. Notably, the delivery of exogenous miR-29a-3p and miR-93-5p enhanced the ability of bone marrow-derived G-exo to attenuate arthritis progression in CIA mice. Exosomes derived from human MDSCs, which overexpressed miR-29a-3p and miR-93-5p, suppressed Th1 and Th17 cell differentiation in vitro. These data showed that G-exo alleviated CIA by suppressing Th1 and Th17 cell responses. Mechanistically, miR-29a-3p and miR-93-5p were verified to inhibit the differentiation of Th1 and Th17 cells, respectively. Our findings demonstrated the therapeutic potential of G-MDSC-derived exosomal miRNAs in autoimmune arthritis.     

Exosomal miR-21-5p derived from bone marrow mesenchymal stem cells promote osteosarcoma cell proliferation and invasion by targeting PIK3R1

Mesenchymal stem cells (MSCs) are a class of pluripotent cells that can release a large number of exosomes which act as paracrine mediators in tumour-associated microenvironment. However, the role of MSC-derived exosomes in pathogenesis and progression of cancer cells especially osteosarcoma has not been thoroughly clarified until now. In this study, we established a co-culture model for human bone marrow-derived MSCs with osteosarcoma cells, then extraction of exosomes from induced MSCs and study the role of MSC-derived exosomes in the progression of osteosarcoma cell. The aim of this study was to address potential cell biological effects between MSCs and osteosarcoma cells. The results showed that MSC-derived exosomes can significantly promote osteosarcoma cells’ proliferation and invasion. We also found that miR-21-5p was significantly over-expressed in MSCs and MSC-derived exosomes by quantitative real-time polymerase chain reaction (qRT-PCR), compared with human foetal osteoblastic cells hFOB1.19. MSC-derived exosomes transfected with miR-21-5p could significantly enhance the proliferation and invasion of osteosarcoma cells in vitro and in vivo. Bioinformatics analysis and dual-luciferase reporter gene assays validated the targeted relationship between exosomal miR-21-5p and PIK3R1; we further demonstrated that miR-21-5p-abundant exosomes derived human bone marrow MSCs could activate PI3K/Akt/mTOR pathway by suppressing PIK3R1 expression in osteosarcoma cells. In summary, our study provides new insights into the interaction between human bone marrow MSCs and osteosarcoma cells in tumour-associated microenvironment.     

Circulating Exosomal miR-17-5p and miR-92a-3p Predict Pathologic Stage and Grade of Colorectal Cancer

Exosomes are extracellular membrane vesicles of 50- to 130-nm diameter secreted by most tumor cells. Exosomes can mediate the intercellular transfer of proteins and RNAs, including microRNAs (miRNAs), and promote both tumorigenesis and premetastatic niche formation. In this study, we performed exosomal RNA sequencing to identify candidate exosomal miRNAs that could be associated with colorectal cancer (CRC) and its distant metastasis. The expression profiles of exosomal miRNA, as secreted by isogenic human primary CRC cell line SW480 and highly metastatic cell line SW620, were analyzed and the potential targets related to tumorigenesis and metastatic progression were investigated. We found that 25 miRNAs had been up-regulated and 5 miRNAs had been down-regulated in exosomes purified from SW620 culture supernatant. Candidate miRNAs were further evaluated for CRC diagnosis using quantitative real-time polymerase chain reaction in CRC patients. Higher expression levels of circulating exosomal miR-17-5p and miR-92a-3p were significantly associated with pathologic stages and grades of the CRC patients. CONCLUSIONS: Circulating exosomal miR-17-5p and miR-92a-3p may provide a promising noninvasive prognostic biomarker for primary and metastatic CRC.     

miR-425-5p as an exosomal biomarker for metastatic prostate cancer

Prostate cancer-related deaths are mostly caused by metastasis, which indicates the importance of identifying clinical prognostic biomarkers. In this study, we evaluated the expression profile of exosomal microRNAs (miRNAs) derived from metastatic prostate cancer (mPCa) cell lines (LNCaP and PC-3). miRNA signatures in exosomes and cells were evaluated by miRNA microarray analysis. Fourteen miRNAs were identified as candidates for specific noninvasive biomarkers. The expression of five miRNAs was validated using RT-qPCR, which confirmed that miR-205-5p, miR-148a-3p, miR-125b-5p, miR-183-5p, and miR-425-5p were differentially expressed in mPCa exosomes. Bioinformatic analyses showed that miR-425-5p was associated with residual tumor, pathologic T and N stages, and TP53 status in PCa samples. Gene ontology analysis of negatively correlated and predicted targeted genes showed enrichment of genes related to bone development pathways. The LinkedOmics database indicated that the potential target HSPB8 has a significant negative correlation with miR-425-5p. In conclusion, this study identified a panel of exosomal miRNAs with potential value as prognostic biomarkers for prostate cancer.     

PCOS follicular fluid derived exosomal miR-424-5p induces granulosa cells senescence by targeting CDCA4 expression

Polycystic ovary syndrome (PCOS) is a heterogeneous reproductive disease, characterized by increased ovarian androgen biosynthesis, chronic anovulation and polycystic ovaries. The objective of this study was to identify the altered miRNA expression profiles in follicular fluid derived exosomes isolated from PCOS patients and to investigate the molecular functions of exosomal miR-424-5p. Herein, small RNA sequencing showed that twenty-five miRNAs were differentially expressed between control and PCOS group. The alterations in the miRNA profile were related to the endocrine resistance, cell growth and proliferation, cellular senescence and insulin signaling pathway. Among these differentially expressed miRNAs, we found that the expression of miR-424-5p was significantly decreased in PCOS exosomes and primary granulosa cells (GCs). Exosome-enriched miR-424-5p significantly promoted GCs senescence and suppressed cell proliferation. Similar to the results obtained in the cells transfected with miR-424-5p mimic, miR-424-5p mimic significantly decreased cell proliferation ability and induced senescence, but treatment with miR-424-5p inhibitor got the opposite results. In addition, cell division cycle associated 4 (CDCA4) gene displayed an inverse expression pattern to those of miR-424-5p, was identified as the direct target of miR-424-5p. Overexpression of CDCA4 reversed the effects of exosomal miR-424-5p on GCs via activation of Rb/E2F1 signaling pathway. These results demonstrate that exosomal miR-424-5p inhibits GCs proliferation and induces cellular senescence in PCOS through blocking CDCA4-mediated Rb/E2F1 signaling. Our findings provide new information on abnormal follicular development in PCOS.     

Downregulation of exosome-encapsulated miR-548c-5p is associated with poor prognosis in colorectal cancer

The role of circulating exosomal microRNAs (miRNAs) in colorectal cancer (CRC) has drawn more and more attention during the past few years. Previously, we have identified several specific miRNAs in serum exosomes as potential CRC biomarkers. However, little is known about the association between exosome-encapsulated miR-548c-5p and outcomes of patients with CRC. In the current study, the expression of serum exosomal miR-548c-5p was investigated by quantitative real-time polymerase chain reaction. Its correlation with CRC prognosis was estimated by Kaplan-Meier survival and log-rank tests. Cox regression analysis based on uni- and multivariate analyses was performed to estimate the relationship of exosome-encapsulated miR-548c-5p with the clinicopathological factors of patients with CRC. Reduced levels of serum exosomal miR-548c-5p were more significant in CRC patients with liver metastasis and at later TNM stage (III/IV tumor stages). Serum exosomal miR-548c-5p could inhibit the proliferation of CRC cells, while the precise molecular mechanisms warranted further elucidation. In addition, decreased levels of serum exosomal miR-548c-5p were independently associated with shorter overall survival in CRC adjusted by age, sex, tumor grade vascular infiltration, TNM stage (III/IV tumor stages) and metastasis (hazard ratio = 3.40, 95% confidence interval 1.02-11.27; P = 0.046). The downregulation of exosomal miR-548c-5p in serum predicts poor prognosis in patients with CRC. Exosomal miR-548c-5p may be a critical biomarker for CRC diagnosis and prognosis.     

Exosomal miRNAs as circulating biomarkers for prediction of development of haematogenous metastasis after surgery for stage II/III gastric cancer

Exosomes secreted by living cancer cells can regulate metastasis. Exosomal miRNAs can reflect pathological conditions of the original cancer cells. Therefore, we aim to identify exosomal miRNAs as circulating biomarkers for haematogenous metastasis of gastric cancer. Pre-treatment serum samples of eighty-nine patients with stage II/III gastric cancer were collected. Thirty-four of them developed haematogenous metastasis after surgery and the other fifty-five did not. Extraction of exosomes was validated by western blot, transmission electron microscopy and nanoparticle tracking analysis. MiRNA qPCR array was performed in three matched pairs of samples. Internal control was selected from PCR array and validated in the remaining samples. Expressions of exosomal miRNAs were evaluated in the remaining samples by RT-qPCR, as well as in gastric cancer tissue samples and cell culture medium. Expression levels of exosomal miRNAs were analysed with clinical characteristics. The results indicated thirteen up-regulated and six down-regulated miRNAs were found after normalization. MiR-379-5p and miR-410-3p were significantly up-regulated in metastatic patients (P < .01). Higher expression of exosomal miR-379-5p or miR-410-3p showed shorter progression-free survival of the patients (P < .05). It was also found that miR-379-5p and miR-410-3p were down-regulated in gastric cancer tissue samples, while they were significantly up-regulated in gastric cancer cell culture medium compared with cancer cells. In conclusion, exosomal miRNAs are promising circulating biomarkers for prediction of development of haematogenous metastasis after surgery for stage II/III gastric cancer.     

Exosomal miR-375 promotes the activity of osteoblasts in prostate cancer

Studies have shown that exosomes influence tumour metastasis, diagnosis, and treatment. It has been found that exosomal miRNAs are closely linked to the metastatic microenvironment. However, the regulatory role of exosomes from prostate cancer (PCa) cells in bone metastasis remains poorly understood. Here, exosomes were isolated and purified by ultracentrifugation, total RNA from cells and total miRNA from exosomes were isolated, and the level of miR-375 was analyzed by RT-PCR. Exosome libraries from LNCaP cells and RWPE-1 cells were sequenced and filtered with an Illumina HiSeq^TM 2500 system. The activity of alkaline phosphatase, the extent of extracellular matrix mineralization, and the expression of osteoblast activity-related marker genes were measured to evaluate osteoblast activity. Morphological observation, particle size analysis, and molecular phenotyping confirmed that the isolated extracts contained exosomes. Differential expression analysis confirmed the high expression of miR-375 in LNCaP cell-derived exosomes. This study suggest that exosomes could enter osteoblasts and increase their miR-375 level. In addition, exosomal miR-375 could significantly promote the activity of osteoblasts.This study lays the foundation for further investigations on the function of exosomal miR-375 in the activation and differentiation of osteoblasts and the mechanism of bone metastasis in PCa.     

Dependence of Intracellular and Exosomal microRNAs on Viral E6/E7 Oncogene Expression in HPV-positive Tumor Cells

Specific types of human papillomaviruses (HPVs) cause cervical cancer. Cervical cancers exhibit aberrant cellular microRNA (miRNA) expression patterns. By genome-wide analyses, we investigate whether the intracellular and exosomal miRNA compositions of HPV-positive cancer cells are dependent on endogenous E6/E7 oncogene expression. Deep sequencing studies combined with qRT-PCR analyses show that E6/E7 silencing significantly affects ten of the 52 most abundant intracellular miRNAs in HPV18-positive HeLa cells, downregulating miR-17-5p, miR-186-5p, miR-378a-3p, miR-378f, miR-629-5p and miR-7-5p, and upregulating miR-143-3p, miR-23a-3p, miR-23b-3p and miR-27b-3p. The effects of E6/E7 silencing on miRNA levels are mainly not dependent on p53 and similarly observed in HPV16-positive SiHa cells. The E6/E7-regulated miRNAs are enriched for species involved in the control of cell proliferation, senescence and apoptosis, suggesting that they contribute to the growth of HPV-positive cancer cells. Consistently, we show that sustained E6/E7 expression is required to maintain the intracellular levels of members of the miR-17~92 cluster, which reduce expression of the anti-proliferative p21 gene in HPV-positive cancer cells. In exosomes secreted by HeLa cells, a distinct seven-miRNA-signature was identified among the most abundant miRNAs, with significant downregulation of let-7d-5p, miR-20a-5p, miR-378a-3p, miR-423-3p, miR-7-5p, miR-92a-3p and upregulation of miR-21-5p, upon E6/E7 silencing. Several of the E6/E7-dependent exosomal miRNAs have also been linked to the control of cell proliferation and apoptosis. This study represents the first global analysis of intracellular and exosomal miRNAs and shows that viral oncogene expression affects the abundance of multiple miRNAs likely contributing to the E6/E7-dependent growth of HPV-positive cancer cells.     

Cancer-secreted exosomal miR-21-5p induces angiogenesis and vascular permeability by targeting KRIT1

Cancer-secreted exosomes are critical mediators of cancer-host crosstalk. In the present study, we showed the delivery of miR-21-5p from colorectal cancer (CRC) cells to endothelial cells via exosomes increased the amount of miR-21-5p in recipient cells. MiR-21-5p suppressed Krev interaction trapped protein 1 (KRIT1) in recipient HUVECs and subsequently activated β-catenin signaling pathway and increased their downstream targets VEGFa and Ccnd1, which consequently promoted angiogenesis and vascular permeability in CRC. A strong inverse correlation between miR-21-5p and KRIT1 expression levels was observed in CRC-adjacent vessels. Furthermore, miR-21-5p expression in circulating exosomes was markedly higher in CRC patients than in healthy donors. Thus, our data suggest that exosomal miR-21-5p is involved in angiogenesis and vascular permeability in CRC and may be used as a potential new therapeutic target.Subject terms: Cancer microenvironment, Colon cancer     

Genome-wide microRNA profiling of bovine milk-derived exosomes infected with <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>

Bovine milk is rich in exosomes, which contain abundant miRNAs and play important roles in the regulation of neonatal growth and development of adaptive immunity. Here, we analyzed miRNA expression profiles of bovine milk exosomes from three healthy and three mastitic cows, and then six miRNA libraries were constructed. Interestingly, we detected no scRNAs and few snRNAs in milk exosomes; this result indicated a potential preference for RNA packaging in milk exosomes. A total of 492 known and 980 novel exosomal miRNAs were detected, and the 10 most expressed miRNAs in the six samples accounted for 80–90% of total miRNA-associated reads. Expression analyses identified 18 miRNAs with significantly different expression between healthy and infected animals; the predicted target genes of differentially expressed miRNAs were significantly enriched in immune system process, response to stimulus, growth, etc. Moreover, target genes were significantly enriched in several Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways including inflammatory, immune, and cancer pathways. Our survey provided comprehensive information about milk exosomes and exosomal miRNAs involved in mastitis. Moreover, the differentially expressed miRNAs, especially miR-223 and miR-142-5p, could be considered as potential candidates for mastitis.     

Comparative profile of exosomal microRNAs in postmenopausal women with various bone mineral densities by small RNA sequencing

To explore the role of plasma miRNAs in exosomes in early postmenopausal women. Small RNA sequencing was implemented to clarify the expression of miRNA in plasma exosomes obtained from 15 postmenopausal women, divided into groups of osteoporosis, osteopenia, and normal bone mass based on bone mineral density. Differentially expressed miRNAs (DEMs) were identified by comparing miRNA expression profiles. Five putative miRNAs, miR-224-3p, miR-25-5p, miR-302a-3p, miR-642a-3p, and miR-766-5p were confirmed by real-time PCR; miRNA target genes were obtained from 4 databases: miRWalk, miRDB, RNA22, and TargetScan. The miRNA-mRNA- Kyoto Encyclopedia of Genes and Genomes (KEGG) networks were analyzed, and the DEMs' potential role was investigated by gene ontology terms and KEGG pathway annotation. The results suggest that characterizing plasma exosomal miRNA profiles of early postmenopausal women by small RNA sequencing could identify novel exo-miRNAs involved in bone remodeling, and miR-642a-3p maybe contribute to the prediction and diagnosis of early postmenopausal osteoporosis.     

高通量测序技术分析急性髓系白血病血浆外泌体微RNA表达谱差异

急性髓系白血病（acute myeloid leukemia,AML）是一类造血干细胞的恶性克隆性疾病,目前的诊断方法不利于疾病的早期发现,且诊断结果重复性较差。已有大量研究显示,细胞外microRNA（miRNA或miR）富集在外泌体（exosome）中,且受其表面膜的保护而具有很好的稳定性,是理想的分子标志物。目前,多种实体肿瘤均已检测到肿瘤特异性外泌体miRNA(exosomal miRNA)。然而,在AML患者中未见此外泌体miRNA报道。本研究探讨急性髓系白血病血浆外泌体miRNA表达谱差异及新miRNA序列。采用solexa高通量测序技术对7例AML患者（AML组）及7例健康对照者（对照组）血浆外泌体miRNAs进行测序,利用Mireap预测软件进行新miRNAs分析,通过edger差异分析软件筛选组间差异miRNA,获得211个已知的差异表达miRNAs以及2个新miRNAs,选择4个差异表达的miRNAs：miR-155-5p、miR-335-5p、miR-451a及xxx-m0038 5p（新miRNA）,在两组（各23例）的血浆外泌体样本中,进行实时荧光定量PCR（qRT-PCR）验证,验证结果与测序结果一致。对差异表达的外泌体miRNA进行靶基因预测及其GO（Gene Ontology）和信号通路富集分析,发现靶基因聚集的生物学功能多数参与生物进展过程的调控。靶基因主要富集在FoxO、MAPK、Hippo信号通路以及HTLV-I感染等。结果显示,AML患者与健康对照者的血浆外泌体miRNA存在着差异性表达。差异性表达的miRNA特异性很高,对进一步阐明AML白血病发生与发展的分子机制、研发新的无创诊断方法、新的诊断标记物和有效治疗AML的方法具有十分重要和深远的意义。     

Pro-angiogenic effect of PC-3 exosomes in endothelial cells in vitro

The progression to a castration-resistant prostate cancer can occur after treatment with androgen deprivation therapy, resulting in poor prognosis and ineffective therapy response. Hormone dependence transition has been associated with increased tumor vascularization. Considering that exosomes are important components in communication between tumor cells and the microenvironment, we examined the angiogenic potential of exosomes released from Pca cell lines with distinctive profiles of androgen response through exosomes isolation, microscopy and uptake, functional assays follow up by microarray, RT-qPCR and bioinformatics analysis. HUVEC cells treated with PC-3 exosomes (androgen independent) showed increased invasion and tube formation ability. In order to identify microRNAs (miRNAs) related to the angiogenic response, the characterization of exosomal miRNA profile was performed. As result we suggest that the miR-27a-3p could be involved in the pro-angiogenic effect of PC-3 exosomes.     

microRNA-16-5p-containing exosomes derived from bone marrow-derived mesenchymal stem cells inhibit proliferation,migration, and invasion,while promoting apoptosis of colorectal cancer cells by downregulating ITGA2

Colorectal cancer (CRC) is a form of cancer developing from either the colon or rectum. Nowadays, research supports the functionality of exosome expressing microRNAs (miRNAs) as potential biomarker for various cancers including CRC. This study was performed with the intent of investigating the roles of both bone marrow-derived mesenchymal stem cells (BMSCs) and exosomal miR-16-5p in CRC by regulating integrin α2 (ITGA2). A microarray-based analysis was conducted to screen the CRC-associated differentially expressed genes (DEGs) as well as potential regulatory miRNAs. Next, the role of miR-16-5p in terms of its progression in association with CRC was determined. Subsequently, CRC cells were exposed to exosomes secreted by BMSCs transfected with miR-16-5p, isolated and cocultured with CRC cells in an attempt to identify the role of exosomes. Effects of BMSCs-derived exosomes overexpressing miR-16-5p on biological functions of CRC cells and tumorigenicity were all subsequently detected. Effects of miR-16-5p treated with CRC cells in regard to CRC in vivo were also measured. ITGA2 was overexpressed, while miR-16-5p was poorly expressed in CRC cells and miR-16-5p targeted ITGA2. The in vitro experiments revealed that the BMSCs-derived exosomes overexpressing miR-16-5p inhibited proliferation, migration, and invasion, while simultaneously stimulating the apoptosis of the CRC cells via downregulation of ITGA2. Furthermore, the results of in vivo experiments confirmed that the BMSCs-derived exosomes overexpressing miR-16-5p repressed the tumor growth of CRC. Collectively, BMSCs-derived exosomes overexpressing miR-16-5p restricted the progression of CRC by downregulating ITGA2.     

Exosomal miR-146a-5p and miR-155-5p promote CXCL12/CXCR7-induced metastasis of colorectal cancer by crosstalk with cancer-associated fibroblasts

C-X-C motif chemokine receptor 7 (CXCR7) is a newly discovered atypical chemokine receptor that binds to C-X-C motif chemokine ligand 12 (CXCL12) with higher affinity than CXCR4 and is associated with the metastasis of colorectal cancer (CRC). Cancer-associated fibroblasts (CAFs) have been known to promote tumor progression. However, whether CAFs are involved in CXCR7-mediated metastasis of CRC remains elusive. We found a significant positive correlation between CXCR7 expression and CAF activation markers in colonic tissues from clinical specimens and in villin-CXCR7 transgenic mice. RNA sequencing revealed a coordinated increase in the levels of miR-146a-5p and miR-155-5p in CXCR7-overexpressing CRC cells and their exosomes. Importantly, these CRC cell-derived miR-146a-5p and miR-155-5p could be uptaken by CAFs via exosomes and promote the activation of CAFs through JAK2–STAT3/NF-κB signaling by targeting suppressor of cytokine signaling 1 (SOCS1) and zinc finger and BTB domain containing 2 (ZBTB2). Reciprocally, activated CAFs further potently enhanced the invasive capacity of CRC cells. Mechanistically, CAFs transfected with miR-146a-5p and miR-155-5p exhibited a robust increase in the levels of inflammatory cytokines interleukin-6, tumor necrosis factor-α, transforming growth factor-β, and CXCL12, which trigger the epithelial–mesenchymal transition and pro-metastatic switch of CRC cells. More importantly, the activation of CAFs by miR-146a-5p and miR-155-5p facilitated tumor formation and lung metastasis of CRC in vivo using tumor xenograft models. Our work provides novel insights into CXCR7-mediated CRC metastasis from tumor–stroma interaction and serum exosomal miR-146a-5p and miR-155-5p could serve as potential biomarkers and therapeutic targets for inhibiting CRC metastasis.Subject terms: Cancer microenvironment, Colon cancer     

Tubular cell-derived exosomal miR-150-5p contributes to renal fibrosis following unilateral ischemia-reperfusion injury by activating fibroblast in vitro and in vivo

Unilateral ischemia reperfusion injury (UIRI) with longer ischemia time is associated with an increased risk of acute renal injury and chronic kidney disease. Exosomes can transport lipid, protein, mRNA, and miRNA to corresponding target cells and mediate intercellular information exchange. In this study, we aimed to investigate whether exosome-derived miRNA mediates epithelial-mesenchymal cell communication relevant to renal fibrosis after UIRI. The secretion of exosomes increased remarkably in the kidney after UIRI and in rat renal tubular epithelium cells (NRK-52E) after hypoxia treatment. The inhibition of exosome secretion by Rab27a knockout or GW4869 treatment ameliorates renal fibrosis following UIRI in vivo. Purified exosomes from NRK-52E cells after hypoxia treatment could activate rat kidney fibroblasts (NRK-49F). The inhibition of exosome secretion in hypoxic NRK-52E cells through Rab27a knockdown or GW4869 treatment abolished NRK-49F cell activation. Interestingly, exosomal miRNA array analysis revealed that miR-150-5p expression was increased after hypoxia compared with the control group. The inhibition of exosomal miR-150-5p abolished the ability of hypoxic NRK-52E cells to promote NRK-49F cell activation in vitro, injections of miR-150-5p enriched exosomes from hypoxic NRK-52E cells aggravated renal fibrosis following UIRI, and renal fibrosis after UIRI was alleviated by miR-150-5p-deficient exosome in vivo. Furthermore, tubular cell-derived exosomal miR-150-5p could negatively regulate the expression of suppressor of cytokine signaling 1 to activate fibroblast. Thus, our results suggest that the blockade of exosomal miR-150-5p mediated tubular epithelial cell-fibroblast communication may provide a novel therapeutic target to prevents UIRI progression to renal fibrosis.     

Cancer-associated fibroblasts-derived exosomes upregulate microRNA-135b-5p to promote colorectal cancer cell growth and angiogenesis by inhibiting thioredoxin-interacting protein

ObjectiveThe role of exosomes in human cancers has been identified, while the effect of cancer-associated fibroblasts (CAFs)-derived exosomes (CAF-exos) transmitting microRNAs (miRNAs) on colorectal cancer (CRC) remains largely unknown. We aim to explore the impact of CAF-derived exosomal miR-135b-5p on CRC progression by targeting thioredoxin-interacting protein (TXNIP).MethodsCRC tissues were collected to obtain CAF-exos, which were used to co-culture with LoVo and HT29 cells. The effect of miR-135b-5p and TXNIP on the in vivo growth, in vitro proliferation, apoptosis, migration, invasion and angiogenesis of CRC cells. miR-135b-5p and TXNIP expression in exosomes and CRC cells were detected and their targeting relationship was confirmed.ResultsMiR-135b-5p was upregulated whereas TXNIP was downregulated in CRC tissues and cells. The CAF-exos and CAF-exos upregulating miR-135b-5p promoted in vivo growth, in vitro proliferation, migration and invasion, and suppressed apoptosis of CRC cells, and also promoted the HUVEC angiogenesis. TXNIP was confirmed as a target of miR-135b-5p and overexpression of TXNIP could weaken the pro-CRC effect of exosomal miR-135b-5p,ConclusionCAF-exos upregulate miR-135b-5p to promote CRC cell growth and angiogenesis by inhibiting TXNIP.