Human mesenchymal stromal cells small extracellular vesicles attenuate sepsis-induced acute lung injury in a mouse model: the role of oxidative stress and the mitogen-activated protein kinase/nuclear factor kappa B pathway

Background aimsAcute lung injury (ALI) secondary to sepsis is a complex disease associated with high morbidity and mortality. Mesenchymal stem cells (MSCs) and their conditioned medium have been demonstrated to reduce alveolar inflammation, improve lung endothelial barrier permeability and modulate oxidative stress in vivo and in vitro. Recently, MSCs have been found to release small extracellular vesicles (sEVs) that can deliver functionally active biomolecules into recipient cells. The authors’ study was designed to determine whether sEVs released by MSCs would be effective in sepsis-induced ALI mice and to identify the potential mechanisms.MethodsA total of 6 h after cercal ligation and puncture, the mice received saline, sEV-depleted conditioned medium (sEVD-CM) or MSC sEVs via the tail vein.ResultsThe administration of MSC sEVs improved pulmonary microvascular permeability and inhibited both histopathological changes and the infiltration of polymorphonuclear neutrophils into lung tissues. In addition, the activities of antioxidant enzymes were significantly increased in the group treated with sEVs compared with the saline and sEVD-CM groups, whereas lipid peroxidation was significantly decreased. Furthermore, sEVs were found to possibly inhibit phosphorylation of the mitogen-activated protein kinase/nuclear factor kappa B (MAPK/NF-κB) pathway and degradation of IκB but increase the activities of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1.ConclusionsThese findings suggest that one of the effective therapeutic mechanisms of sEVs against sepsis-induced ALI may be associated with upregulation of anti-oxidative enzymes and inhibition of MAPK/NF-κB activation.     

miR-33a-5p in small extracellular vesicles as non-invasive biomarker for oxaliplatin sensitivity in human colorectal cancer cells

microRNAs (miRNAs) contained in small extracellular vesicles (sEVs) are candidates for non-invasive biomarkers. Oxaliplatin (L-OHP) has been approved for advanced colorectal cancer (CRC) chemotherapy. However, the response to L-OHP differs among CRC patients. In addition, CRC cells often acquire the resistance to L-OHP. This study aimed at the prediction of L-OHP sensitivity by measuring extracellular miRNAs levels. Firstly, we compared intracellular miRNAs expressions in L-OHP-sensitive CRC cells (SW620 and HCT116 cells) with those in acquired and intrinsic L-OHP-resistant cells. In microarray and real-time RT-PCR analyses, the intracellular miR-33a-5p, miR-210–3p, and miR-224–5p expressions were lower in acquired and intrinsic L-OHP-resistant CRC cells than sensitive cells. Furthermore, in SW620 cells, L-OHP sensitivity was decreased by miR-33a-5p inhibitor. On the other hand, miR-210–3p or miR-224–5p inhibitor did not affect L-OHP sensitivity in SW620 cells. Secondly, the amount of miR-33a-5p, miR-210–3p, and miR-224–5p in sEVs was compared. The amount of miR-33a-5p and miR-210–3p in sEVs secreted from acquired and intrinsic L-OHP-resistant cells tended to be small. miR-224–5p was not detected in sEVs secreted from three types of CRC cells examined. To the best of our knowledge, this is the first study demonstrating that miR-33a-5p and/or miR-210–3p in sEVs would be candidates for biomarkers of L-OHP sensitivity. In particular, miR-33a-5p is a promising candidate because it would be directly involved in L-OHP sensitivity.     

miR-21-5p in extracellular vesicles obtained from adipose tissue-derived stromal cells facilitates tubular epithelial cell repair in acute kidney injury

Background aimsAcute kidney injury (AKI) is often associated with poor patient outcomes. Extracellular vesicles (EVs) have a marked therapeutic effect on renal recovery. This study sought to explore the functional mechanism of EVs from adipose tissue-derived stromal cells (ADSCs) in tubular epithelial cell (TEC) repair in AKI.MethodsADSCs were cultured and EVs were isolated and identified. In vivo and in vitro AKI models were established using lipopolysaccharide (LPS).ResultsEVs increased human kidney 2 (HK-2) cell viability; decreased terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells and levels of kidney injury molecule 1, cleaved caspase-1, apoptosis-associated speck-like protein containing a CARD, gasdermin D-N, IL-18 and IL-1β; and elevated pro-caspase-1. EVs carried miR-21-5p into LPS-induced HK-2 cells. Silencing miR-21-5p partly eliminated the ability of EVs to suppress HK-2 cell pyroptosis and inflammation. miR-21-5p targeted toll-like receptor 4 (TLR4) and inhibited TEC pyroptosis and inflammation after AKI by inhibiting TLR4. TLR4 overexpression blocked the inhibitory effects of EVs on TEC pyroptosis and inflammation. EVs suppressed the nuclear factor-κB/NOD-like receptor family pyrin domain-containing 3 (NF-κB/NLRP3) pathway via miR-21-5p/TLR4. Finally, AKI mouse models were established and in vivo assays verified that ADSC-EVs reduced TEC pyroptosis and inflammatory response and potentiated cell repair by mediating miR-21-5p in AKI mice.ConclusionsADSC-EVs inhibited inflammation and TEC pyroptosis and promoted TEC repair in AKI by mediating miR-21-5p to target TLR4 and inhibiting the NF-κB/NLRP3 pathway.     

Licochalcone A reverses NNK-induced ectopic miRNA expression to elicit in vitro and in vivo chemopreventive effects

BackgroundChemoprevention is the best cost-effective way regarding cancers. MicroRNAs (miRNAs) have been reported to be differentially expressed during the development of lung cancer. However, if lung cancer prevention can be achieved through modulating miRNAs expression so far remains unknown.PurposeTo discover ectopically expressed miRNAs in NNK-induced lung cancer and clarify whether Licochalcone A (lico A) can prevent NNK-induced lung cancer by modulating miRNA expression.Study design and methodsA/J mice were used to construct a lung cancer model by intraperitoneal injection with physiological saline NNK (100 mg/kg). Chemopreventive effects of lico A against lung cancer at 2 mg/kg and 20 mg/kg doses were evaluated in vivo. MicroRNA array and RT-qPCR were used to assess the expression levels of miRNAs. MLE-12 cells were treated with 0.1 mg/ml NNK, stimulating the ectopic expression pattern of miR-144-3p, miR-20a-5p, miR-29c-3p, let-7d-3p, and miR-328-3p. miR-144-3p mimics and inhibitors were used to manipulate miR-144-3p levels. The effects of lico A (10 μM) on cell cycle distribution, apoptosis, and the expression of CK19, RASA1, miR-144-3p, miR-20a-5p, miR-29c-3p, let-7d-3p, and miR-328-3p in NNK-treated MLE-12 cells were studied.ResultsThe expression levels of miR-144-3p, miR-20a-5p, and miR-29c-3p increased, while those of let-7d-3p and miR-328-3p decreased in both NNK-induced A/J mice and MLE-12 cells. Lico A could reverse the NNK-induced ectopic miRNA (miR-144-3p, miR-20a-5p, miR-29c-3p, let-7d-3p, and miR-328-3p) expression both in vivo and in vitro and elicit in vivo lung cancer chemopreventive effect against NNK. In MLE-12 cells, the overexpression of miR-144-3p elicited the same effect as NNK regarding the expression of lung cancer biomarker CK19; the silencing of miR-144-3p reversed the effect of NNK on cell cycle distribution and apoptosis. Lico A could reverse the effect of NNK on the expression of miR-144-3p, CK19, and RASA1 (predicted target of miR-144-3p).ConclusionThe present study suggests that miR-144-3p, miR-20a-5p, miR-29c-3p, let-7d-3p, and miR-328-3p were involved in the in vivo pathogenesis of NNK-induced lung cancer, and lico A could reverse the effect of NNK both in vivo and in vitro to elicit lung cancer chemopreventive effects through, at least partially, these five ectopically expressed miRNAs, especially miR-144-3p.     

In vitro and in vivo anti-metastatic effect of the alkaliod matrine from Sophora flavecens on hepatocellular carcinoma and its mechanisms

BackgroundsHepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancer with high metastasis and recurrence rates. Hypoxia-induced miRNAs and HIF-1α are demonstrated to play essential roles in tumor metastasis. Matrine (C₁₅H₂₄N₂O), an alkaloid extracted from Sophora flavescens Aiton, has been used as adjuvant therapy for liver cancer in China. The anti-metastasis effects of matrine on HCC and the underlying mechanisms remain poorly understood.PurposeWe aimed to investigate the effects of matrine on metastasis of HCC both in vitro and in vivo, and explored whether miR-199a-5p and HIF-1α are involved in the action of matrine.MethodsMTT method, colony formation, wound healing and matrigel transwell assays were performed to evaluate the effects of matrine on cell proliferation, migration and invasion. Nude mice xenograft model and immunohistochemistry (IHC) assay were employed to investigate the anti-metastatic action of matrine in vivo. Quantitative real-time PCR, western blot and dual luciferase reporter assay were conducted to determine the underlying mechanisms of matrine.ResultsMatrine exerted stronger anti-proliferative action on Bel7402 and SMMC-7721 cells under hypoxia than that in normoxia. Both matrine and miR-199a-5p exhibited significant inhibitory effects on migration, invasion and EMT in Bel7402 and SMMC-7721 cells under hypoxia. Further study showed that miR-199a-5p was downregulated in HCC cell lines, and this microRNA was identified to directly target HIF-1α, resulting in decreased HIF-1α expression. Matrine induced miR-199a-5p expression, decreased HIF-1α expression and inhibited metastasis of Bel7402 and SMMC-7721 cells, while miR-199a-5p knockdown reversed the inhibitory effects of matrine on cell migration, invasion, EMT and HIF-1α expression. In vivo, matrine showed significant anti-metastatic activity in the nude mouse xenograft model. H&E and IHC analysis indicated that lung and liver metastasis nodules were reduced, and the protein expression of HIF-1α and Vimentin were significantly decreased by i.p injection of matrine.ConclusionsMatrine exhibits significant anti-metastatic effect on HCC, which is attributed to enhanced miR-199a-5p expression and subsequently impaired HIF-1α signaling and EMT. These findings suggest that miR-199a-5p is a potential therapeutic target of HCC, and matrine may represent a promising anti-metastatic medication for HCC therapy.     

Immune regulatory targets of mesenchymal stromal cell exosomes/small extracellular vesicles in tissue regeneration

Mesenchymal stromal cell (MSC) therapies have demonstrated therapeutic efficacy in a wide-ranging array of tissue injury and disease indications. An important aspect of MSC-mediated therapeutic activities is immune modulation. Consistent with the concentration of MSC therapeutic potency in its secretion, a significant proportion of MSC immune potency resides in the small extracellular vesicles (sEVs) secreted by MSCs. These sEVs, which also include exosomes, carry a large cargo enriched in proteins with potent immunomodulatory activities. They have been reported to exert potent effects on humoral and cellular components of the immune system in vitro and in vivo, and may have the potential to support the diametrically opposite pro- and anti-inflammatory functions necessary for tissue repair and regeneration following injury. Following injury, pro-inflammatory activities are necessary to neutralize injury and remove dead or injured tissue, while anti-inflammatory activities to facilitate migration and proliferation of reparative cell types and to increase vascularization and nutrient supply are necessary to repair and regenerate new tissue. Therefore, a critical immunomodulatory requisite of MSC sEVs in tissue regeneration is the capacity to support the appropriate immune activities at the appropriate time. Here, we review how some of the immune regulatory targets of MSC sEVs could support the dynamic immunomodulatory activities during tissue repair and regeneration.     

Suppression of LINC00707 alleviates lipopolysaccharide-induced inflammation and apoptosis in PC-12 cells by regulated miR-30a-5p/Neurod 1

ABSTRACT

Long noncoding RNA (lncRNA) has emerged as a pivotal regulator improving neural regeneration in the progression of spinal cord injury (SCI). However, whether lncRNAs can be targeted for therapeutic intervention of SCI remains unclear. In this study, we found that LINC00707 expression was significantly up-regulated in lipopolysaccharide (LPS)-treated PC-12, a model that mimics nerve cell injury in an inflammatory environment after SCI. Suppression of LINC00707 alleviated LPS-induced inflammation and apoptosis in PC-12 cells. Furthermore, we found that LINC00707 adsorbed miR-30a-5p and silenced miR-30a-5p or overexpressed Neurod 1 reversed the effect of LINC00707 on the inflammation and apoptosis of LPS-treated PC-12 cells. These findings revealed that LINC00707 alleviates LPS-induced inflammation and apoptosis in PC-12 cells by targeting miR-30a-5p/Neurod 1, providing a preliminary theoretical basis for the clinical application of LINC00707 in SCI.     

miR-146a-5p circuitry uncouples cell proliferation and migration,but not differentiation,in human mesenchymal stem cells

Administration of mesenchymal stem cells (MSCs) has the potential to ameliorate degenerative disorders and to repair damaged tissues. The homing of transplanted MSCs to injured sites is a critical property of engraftment. Our aim was to identify microRNAs involved in controlling MSC proliferation and migration. MSCs can be isolated from bone marrow and umbilical cord Wharton’s jelly (BM-MSCs and WJ-MSCs, respectively), and WJ-MSCs show poorer motility yet have a better amplification rate compared with BM-MSCs. Small RNA sequencing revealed that miR-146a-5p is significantly overexpressed and has high abundance in WJ-MSCs. Knockdown of miR-146a-5p in WJ-MSCs inhibited their proliferation yet enhanced their migration, whereas overexpression of miR-146a-5p in BM-MSCs did not influence their osteogenic and adipogenic potentials. Chemokine (C-X-C motif) ligand 12 (CXCL12), together with SIKE1, which is an I-kappa-B kinase epsilon (IKKε) suppressor, is a direct target of miR-146a-5p in MSCs. Knockdown of miR-146a-5p resulted in the down-regulation of nuclear factor kappa-B (NF-κB) activity, which is highly activated in WJ-MSCs and is known to activate miR-146a-5p promoter. miR-146a-5p is also downstream of CXCL12, and a negative feedback loop is therefore formed in MSCs. These findings suggest that miR-146a-5p is critical to the uncoupling of motility and proliferation of MSCs. Our miRNome data also provide a roadmap for further understanding MSC biology.     

MiR-125a-3p inhibits cell proliferation and inflammation responses in fibroblast-like synovial cells in rheumatoid arthritis by mediating the Wnt/β-catenin and NF-κB pathways via targeting MAST3

Objectives:To explore the role and mechanism of miR-125a-3p in rheumatoid arthritis (RA) progression.Methods:The RA-tissues and fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS) were used in this study. qRT-PCR, western blot and ELISA assay were performed to detect the expression levels of IL-6, IL-β and ΤΝF-α. Dual-luciferase reporter gene assay was used to observe the binding effect of miR-125a-3p and MAST3, and CCK-8 was used to observe the effect of miR-125a-3p on the proliferation of RA-FLS.Results:miR-125a-3p was significantly downregulated in the RA-tissues and RA-FLS, and miR-125a-3p could inhibit the proliferation and reduce the inflammation response of RA-FLS. Besides, MAST3 was found as a target of miR-125a-3p, and increased MAST3 could reverse the effects of miR-125a-3p on RA-FLS including decreased proliferation, reduced inflammation level and the inactivation of Wnt/β-catenin and NF-κB pathways.Conclusions:This study suggests that miR-125a-3p could inactivate the Wnt/β-catenin and NF-κB pathways to reduce the proliferation and inflammation response of RA-FLS via targeting MAST3.     

支气管哮喘患者血清miR-29a-3p、miR-98-5p表达水平与肺功能、气道炎症和糖皮质激素治疗敏感性的关系研究

摘要 目的：探讨支气管哮喘（BA）患者血清微小核糖核酸（miR）-29a-3p、miR-98-5p表达水平与肺功能、气道炎症和糖皮质激素（GC）治疗敏感性的关系。方法：选取2020年1月～2022年1月潍坊市人民医院收治的150例BA患者为BA组,根据BA患者GC治疗敏感性将其分为抵抗组43例和敏感组107例,另选取同期57名体检健康者为对照组。收集BA组、对照组肺功能和气道炎症指标资料,采用实时荧光定量逆转录聚合酶链式反应（qRT-PCR）检测两组血清miR-29a-3p、miR-98-5p表达水平。通过Spearman相关性分析BA患者血清miR-29a-3p、miR-98-5p表达水平与肺功能和气道炎症指标的相关性,单因素和多因素Logistic回归分析BA患者GC治疗抵抗的影响因素。结果：与对照组比较,BA组血清miR-29a-3p、miR-98-5p表达水平和第1秒用力呼气容积占预计值百分比（FEV₁％）、第1秒用力呼气容积/用力肺活量（FEV₁/FVC）、峰值呼气流速（PEF）降低,呼出气一氧化氮（FeNO）水平升高（P均＜0.05）。Spearman相关性分析显示,BA患者血清miR-29a-3p、miR-98-5p表达水平与FEV₁％、FEV₁/FVC、PEF呈正相关,与FeNO水平呈负相关（P均＜0.05）。单因素分析显示,抵抗组体质指数＞24 kg/m²、吸烟比例高于敏感组,血清miR-29a-3p、miR-98-5p表达水平低于敏感组（P＜0.05）。多因素Logistic回归分析显示,体质指数＞24 kg/m²、吸烟为BA患者GC治疗抵抗的独立危险因素,血清miR-29a-3p、miR-98-5p表达水平升高为其独立保护因素（P均＜0.05）。结论：BA患者血清miR-29a-3p、miR-98-5p水平降低,与肺功能下降、气道炎症和GC治疗抵抗有关。     

Bone marrow-derived mesenchymal stem cells repair severe acute pancreatitis by secreting miR-181a-5p to target PTEN/Akt/TGF-β1 signaling

BackgroundSevere acute pancreatitis (SAP) is associated with high morbidity and mortality. Bone marrow mesenchymal stem cells (BMSCs) have shown obvious protective effect on SAP. However, little is known about the underlying mechanism. The objective of this study is to unravel the role and regulatory mechanism of miR-181a-5p in BMSCs-mediated pancreatic repair.MethodsBMSCs were isolated from Sprague-Dawley rats and characterized by flow cytometry and Oil Red O staining. Sodium taurocholate- and caerulein-induced models were used as SAP models in vivo and in vitro, respectively. Pancreatic injury were evaluated by H&E and histopathological analysis, as well as by measuring levels of amylase, lipase and cytokines. qRT-PCR and western blotting were performed to detect the level of miR-181a-5p and the protein levels of PTEN/Akt, respectively. ELISA was conducted to detect the levels of TNF-α, IL-1β, IL-6, angiopoietin, IL-4, IL-10 and TGF-β1. The apoptotic rate of AR42 J cells was quantitated by concurrent staining with Annexin-V-FITC and PI.ResultsBMSCs significantly attenuated pancreatic injury in SAP rats by reducing inflammatory infiltration and necrosis, and this effect was abolished by CXCR4 agonist AMD3100. ADM3100 exhibited more severe pancreatic injury and decreased miR-181a-5p levels in the pancreas and serum compared to SAP group. Overexpression of miR-181a-5p in BMSCs (BMSCs-miR-181a-5p) markedly potentiated the protective effect of BMSCs by reducing histological damage and levels of amylase and lipase. Moreover, BMSCs-miR-181a-5p dramatically reduced levels of angiopoietin, TNF-α, IL-1β and IL-6, but induced the levels of IL-4 and IL-10. In caerulein-treated AR42 J cells, co-culturing of BMSCs-miR-181a-5p alleviated caerulein-induced increase of amylase and lipase, and apoptosis via PTEN/Akt/TGF-β1 signaling.ConclusionBMSCs alleviate SAP and reduce inflammatory responses and apoptosis by secreting miR-181a-5p to target PTEN/Akt/TGF-β1 signaling. Hence, BMSCs-miR-181a-5p could serve as potential therapeutic target for SAP.     

miR-21a-5p Promotes Inflammation following Traumatic Spinal Cord Injury through Upregulation of Neurotoxic Reactive Astrocyte (A1) Polarization by Inhibiting the CNTF/STAT3/Nkrf Pathway

Reactive astrocytes are implicated in traumatic spinal cord injury (TSCI). Interestingly, naïve astrocytes can easily transform into neurotoxic reactive astrocytes (A1s) with inflammatory stimulation. Previous studies demonstrated that microRNA(miR)-21a-5p was up-regulated in spinal cord tissue after TSCI; however, it is not clear whether this affected reactive astrocyte polarization. Here, we aim to detect the effects of miR-21a-5p on the induction of A1 formation and the underlying mechanisms. Our study found that the expression of miR-21a-5p was significantly increased while that of Cntfr α was decreased, since naïve astrocytes transformed into A1s 3 days post-TSCI; the binding site between miR-21a-5p and Cntfr α was further confirmed in astrocytes. After treatment with CNTF, the levels of A1 markers decreased while that of A2 increased. The expression of A1 markers significantly decreased with the downregulation of miR-21a-5p, while Cntfr α siRNA treatment caused the opposite both in vitro and in vivo. To summarize, miR-21a-5p/Cntfr α promotes A1 induction and might enhance the inflammatory process of TSCI; furthermore, we identified, for the first time, the effect and potential mechanism by which CNTF inhibits naïve astrocytes transformation into A1s. Collectively, our findings demonstrate that targeting miR-21a-5p represents a prospective therapy for promoting the recovery of TSCI.     

miR-27a is up regulated and promotes inflammatory response in sepsis

MicroRNAs (miRNAs) are short, non-coding RNAs that regulate the expression of multiple target genes. Dysregulation of miRNAs is common in sepsis. Through microRNA microarray and qRT-PCR we found that the levels of miR-27a, miR-153 and miR-143 are up regulated, while let-7a, miR-218 and miR-129-5p are down regulated in lungs of septic mice. Knocking down of miR-27a down regulates expression levels of TNF-α and IL-6 significantly via reducing the phosphorylation level of NF-κB p65 and inhibiting its DNA binding activity. Furthermore, neutralisation of miR-27a up regulates PPARγ level, down regulates TNF-α expression, relieves pulmonary inflammation and promotes survival of septic mice, which demonstrates that miR-27a plays an important role in regulating inflammatory response in sepsis and provides a potential target for clinical sepsis research and treatment.     

LncRNA GIHCG promoted the proliferation and migration of renal cell carcinoma through regulating miR-499a-5p/XIAP axis

BackgroundOur previous study demonstrated that lncRNA GIHCG is upregulated in renal cell carcinoma (RCC) and that knockdown of lncRNA GIHCG suppresses the proliferation and migration of RCC cells. However, the mechanism of lncRNA GIHCG in RCC needs further exploration.MethodsThe proliferation, cell cycle, migration, and apoptosis of RCC cells were tested using CCK-8, flow cytometry, wound healing and Annexin-V/-FITC/PI flow cytometry assays, respectively. Dual-luciferase reporter and RNA pull-down or RNA immunoprecipitation assays (RIPs) were performed to analyze the interactions among lncRNA GIHCG, miR-499a-5p and XIAP. A tumour xenograft study was conducted to verify the function of lncRNA GIHCG in RCC development in vivo.ResultsKnockdown of lncRNA GIHCG inhibited cell proliferation and migration and induced G0/G1 arrest while promoting apoptosis. Overexpression of lncRNA GIHCG led to the opposite results. LncRNA GIHCG sponged miR-499a-5p and downregulated its expression in RCC cells. MiR-499a-5p overexpression suppressed RCC cell growth. MiR-499a-5p targeted XIAP and inhibited its expression. LncRNA GIHCG knockdown reduced the growth of tumour xenografts in vivo and the expression of XIAP while increasing miR-499a-5p levels.ConclusionLncRNA GIHCG accelerated the development of RCC by targeting miR-499a-5p and increasing XIAP levels.     

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.     

Effect and possible mechanisms of dioscin on ameliorating metabolic glycolipid metabolic disorder in type-2-diabetes

BackgroundOur previous study revealed that microRNA-125a-5p plays a crucial role in regulating hepatic glycolipid metabolism by targeting STAT3 in type 2 diabetes mellitus (T2DM). Dioscin, a major active ingredient in Dioscoreae nipponicae rhizomes, displays various pharmacological activities, but its role in T2DM has not been reported.PurposeThe aim of this study was to investigate the effect of dioscin on T2DM and elucidate its potential mechanism.MethodsThe effect of dioscin on glycolipid metabolic disorder in insulin-induced HepG2 cells, palmitic acid-induced AML12 cells, high-fat diet- and streptozotocin- induced T2DM rats, and spontaneous T2DM KK-Ay mice were evaluated. Then, the possible mechanisms of dioscin were comprehensively evaluated.ResultsDioscin markedly alleviated the dysregulation of glycolipid metabolism in T2DM by reducing hyperglycemia and hyperlipidemia, improving insulin resistance, increasing hepatic glycogen content, and attenuating lipid accumulation. When the mechanism was investigated, dioscin was found to markedly elevate miR-125a-5p level and decrease STAT3 expression. Consequently, dioscin increased phosphorylation levels of STAT3, PI3K, AKT, GSK-3β, and FoxO1 and decreased gene levels of PEPCK, G6Pase, SREBP-1c, FAS, ACC, and SCD1, leading to an increase in glycogen synthesis and a decrease in gluconeogenesis and lipogenesis. The effects of dioscin on regulating miR-125a-5p/STAT3 pathway were verified by miR-125a-5p overexpression and STAT3 overexpression.ConclusionsDioscin showed potent anti-T2DM activity by improving the inhibitory effect of miR-125a-5p on STAT3 signaling to alleviate glycolipid metabolic disorder of T2DM.