Long noncoding RNA XIST promotes cell proliferation and migration in diabetic foot ulcers through the miR-126-3p/EGFR axis

BACKGROUND

The prevalence of diabetic foot ulcers (DFUs) has caused serious harm to human health. To date, a highly effective treatment is lacking. Long noncoding RNA X-inactive specific transcript (lncRNA XIST) has been the subject of mounting research studies, all of which have found that it serves as a protective factor against certain diseases; however, its function in DFUs is not entirely understood. This study was performed to determine the importance of the lncRNA XIST in the pathogenesis and biological function of DFUs.

METHODS

Diabetic ulcer skin from rats was analysed using haematoxylin-eosin (HE), Masson's trichrome, and immunohistochemistry (IHC) staining. The differences in the expression of genes and proteins were examined with real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting. Next, the interaction was verified with a dual luciferase gene reporter assay. In addition, CCK-8, Transwell, and wound healing assays were used to assess the proliferation and migration of HaCaT cells.

RESULTS

The lncRNA XIST and epidermal growth factor receptor (EGFR) were downregulated, while microRNA-126-3p (miR-126-3p) was increased in diabetic ulcer rat skin tissues and high glucose-induced HaCaT cells. In addition, we found that the lncRNA XIST binds to miR-126-3p and that EGFR is directly targeted by miR‑126‑3p. Silencing XIST contributed to upregulated miR-126-3p expression, thus lowering EGFR levels and inhibiting the proliferative and migratory abilities of high glucose-treated HaCaT cells; however, the miR-126-3p inhibitor and overexpression of EGFR reversed this effect.

CONCLUSION

Decreased lncRNA XIST expression inhibits the proliferative and migratory abilities of high glucose-induced HaCaT cells by modulating the miR-126-3p/EGFR axis, causing delayed wound healing.

Astragaloside IV promotes exosome secretion of endothelial progenitor cells to regulate PI3KR2/SPRED1 signaling and inhibit pyroptosis of diabetic endothelial cells

BACKGROUND AIMS

Treating chronic non-healing diabetic wounds and achieving complete skin regeneration has always been a critical clinical challenge.

METHODS

In order to address this issue, researchers conducted a study aiming to investigate the role of miR-126-3p in regulating the downstream gene PIK3R2 and promoting diabetic wound repair in endothelial progenitor cell (EPC)-derived extracellular vesicles. The study involved culturing EPCs with astragaloside IV, transfecting them with miR-126-3p inhibitor or mock plasmid, interfering with high glucose-induced damage in human umbilical vein endothelial cells (HUVECs) and treating diabetic skin wounds in rats.

RESULTS

The healing of rat skin wounds was observed through histological staining. The results revealed that treatment with miR-126-3p-overexpressing EPC-derived extracellular vesicles accelerated the healing of rat skin wounds and resulted in better tissue repair with slower scar formation. In addition, the transfer of EPC-derived extracellular vesicles with high expression of miR-126-3p to high glucose-damaged HUVECs increased their proliferation and invasion, reduced necrotic and apoptotic cell numbers and improved tube formation. In this process, the expression of angiogenic factors vascular endothelial growth factor (VEGF)A, VEGFB, VEGFC, basic fibroblast growth factor and Ang-1 significantly increased, whereas the expression of caspase-1, NRLP3, interleukin-1β, inteleukin-18, PIK3R2 and SPRED1 was suppressed. Furthermore, miR-126-3p was able to target and inhibit the expression of the PIK3R2 gene, thereby restoring the proliferation and migration ability of high glucose-damaged HUVEC.

CONCLUSIONS

In summary, these research findings demonstrate the important role of miR-126-3p in regulating downstream genes and promoting diabetic wound repair, providing a new approach for treating chronic non-healing diabetic wounds.

IFN-γ enhances the therapeutic efficacy of MSCs-derived exosome via miR-126-3p in diabetic wound healing by targeting SPRED1

BACKGROUND AND AIMS

The traditional treatment of diabetic wounds is unsatisfactory. Exosomes isolated from bone marrow mesenchymal stem cells (BMSCs) promote the healing of diabetic wounds. However, whether the exosomes secreted by interferon (IFN)-γ-pretreated BMSCs have an enhanced therapeutic effect on diabetic wound healing and the relevant mechanisms remain unclear.

METHODS

In this study, we isolated exosomes from the corresponding supernatants of BMSCs with (IExos) or without IFN-γ treatment (NExos). Human umbilical vein endothelial cells (HUVECs) were used to investigate the proliferation, migration, and tube formation under different treatments in vitro. Diabetic mice were induced by intraperitoneal administration of streptozotocin, and a circular full-thickness dermal defect was then made on the back of each mouse, followed by a multisite subcutaneous injection of phosphate buffered saline or exosomes. Hematoxylin-eosin (H&E) staining, Masson's trichrome staining, and histological analysis were performed to assess the speed and quality of wound healing.

RESULTS

NExos treatment accelerated the healing of diabetic wounds by promoting angiogenesis in vivo and in vitro, and IExos exhibited superior therapeutic efficiency. MicroRNA (miR)-126-3p was significantly increased in IExos, and exosomal miR-126-3p promoted angiogenesis and diabetic wound healing via its transfer to HUVECs. miR-126-3p regulates SPRED1 by directly targeting the 3'-UTR. Mechanistically, IFN-γ-pretreated BMSCs secreted miR-126-3p-enriched exosomes, which enhanced the function of HUVECs and promoted angiogenesis via the SPRED1/Ras/Erk pathway.

CONCLUSION

Exosomal miR-126-3p secreted from IFN-γ-pretreated BMSCs exhibited higher therapeutic efficacy than NExos in diabetic wound healing by promoting angiogenesis via the SPRED1/Ras/Erk axis.

Global DNA methylation and miR-126-3p expression in Mexican women with gestational diabetes mellitus: a pilot study

BACKGROUND

Gestational diabetes mellitus (GDM), a type of diabetes that occurs for the first time during pregnancy, may predispose the development of chronic degenerative diseases and metabolic alterations in mother and offspring. DNA methylation and microRNA (miRNA) expression are regulatory mechanisms of gene expression that may contribute to the pathogenesis of GDM. Therefore, we determined global DNA methylation and miR-126-3p expression levels in 8 and 7 Mexican women with and without GDM, respectively.

METHODS AND RESULTS

Global DNA methylation was assessed by measuring the percentage of 5-methylcytosine (5-mC) in placenta, umbilical cord, and plasma DNA samples, whereas miR-126-3p expression was quantified by real-time PCR using the 2-ΔCt method of the corresponding RNA samples. A significant increase in the percentage of 5-mC was detected in placenta samples from GDM patients compared to healthy women, while plasma samples showed a significant decrease. Conversely, miR-126-3p expression levels were significantly higher in plasma from the GDM group, while placenta and umbilical cord samples showed no significant differences across experimental groups. Furthermore, DNA methylation correlated significantly with glucose levels in placenta and plasma. Likewise, miR-126-3p expression correlated significantly with plasma glucose, in addition to maternal body mass index (BMI at first trimester).

CONCLUSION

The results indicate that GDM is associated with alterations in global DNA methylation levels and miR-126-3p expression in placenta and/or plasma, providing insights into future novel approaches to diagnose and/or prevent this pathology.

Alterations in Serum miR-126-3p Levels over Time: A Marker of Pituitary Insufficiency following Head Trauma

INTRODUCTION

Traumatic brain injuries (TBIs) pose a high risk of pituitary insufficiency development in patients. We have previously reported alterations in miR-126-3p levels in sera from patients with TBI-induced pituitary deficiency.

METHODS

To investigate why TBI-induced pituitary deficiency develops only in some patients and to reveal the relationship between miR-126-3p with hormone axes, we used mice that were epigenetically modified with miR-126-3p at the embryonic stage. These modified mice were subjected to mild TBI (mTBI) according to the Marmarou's weight-drop model at 2 months of age. The levels of miR-126-3p were assessed at 1 and 30 days in serum after mTBI. Changes in miR-126-3p levels after mTBI of wild-type and miR-126-3p* modified mouse lines validated our human results. Additionally, hypothalamus, pituitary, and adrenal tissues were analyzed for transcripts and associated serum hormone levels.

RESULTS

We report that miR-126-3p directly affects hypothalamus-pituitary-adrenal (HPA) axis upregulation and ACTH secretion in the acute phase after mTBI. We also demonstrated that miR-126-3p suppresses Gnrh transcripts in the hypothalamus and pituitary, but this is not reflected in serum FSH/LH levels. The increase in ACTH levels in the acute phase may indicate that upregulation of miR-126-3p at the embryonic stage has a protective effect on the HPA axis after TBI. Notably, the most prominent transcriptional response is found in the adrenals, highlighting their role in the pathophysiology of TBI.

CONCLUSION

Our study revealed the role of miR-126-3p in TBI and pituitary deficiency developing after TBI, and the obtained data will significantly contribute to elucidating the mechanism of pituitary deficiency development after TBI and development of new diagnostic and treatment strategies.

Alteration of circulating miRNAs during myocardial infarction and association with lipid levels

BACKGROUND

Increasing mortality and morbidity of coronary artery disease (CAD) highlight the emerging need for novel noninvasive markers such as circulating microRNAs (miRNAs).

OBJECTIVE

To evaluate the circulating levels of miR-126-3p, miR-210-3p, let-7g-5p, and miR-326, and their associations with known contributors to CAD, in CAD subgroups.

METHODS

We divided the cohort into 4 groups: non-CAD controls (≤30% stenosis; n = 55), and patients with stable angina pectoris (SAP; n = 48), unstable AP (UAP; n = 46), and myocardial infarction (MI; n = 36). The circulating levels of miR-126-3p, miR-210-3p, let-7g-5p, and miR-326 were determined using TaqMan Advanced miRNA Assays in serum specimens.

RESULTS

Circulating miR-126-3p levels were lower in the MI and UAP groups, compared with the non-CAD group, whereas miR-210-3p circulating levels were lower in the MI group than others. The levels of circulating let-7g-5p were shown to be useful for distinguishing UAP from MI, and there were substantial differences in circulating let-7g-5p levels between the UAP and MI groups. Moreover, lipid levels and ratios were lower in individuals with high circulating miR-126-3p and miR-210-3p levels.

CONCLUSIONS

The study results suggest that circulating miR-126-3p, miR-210-3p, and let-7g-5p are differentiated between different clinical presentations of CAD and associated with lipid levels, which are important risk factors and determinants of CAD.

Mechanism of human chorionic gonadotropin in endometrial receptivity via the miR-126-3p/PI3K/Akt/eNOS axis

Human chorionic gonadotropin (hCG) might affect endometrial receptivity, exerting integral roles in embryo implantation. This study explored the action of hCG in endometrial receptivity via the miR-126-3p/PIK3R2/PI3K/Akt/eNOS axis. The embryo implantation dysfunction (EID) mouse models were established by administrating mifepristone and human endometrial epithelial cells (EECs) were used for in vivo experiments, both followed by hCG treatment. Expression level of CD105 and protein levels of cadherin CD144 and CD146 in mice were determined by immunohistochemistry and Western blot. The levels of miR-126-3p and PIK3R2 mRNA and PIK3R2, p-PI3K p85 α, PI3K p110 α, p-Akt, Akt, p-eNOS, and eNOS protein levels were measured. Cell proliferation was evaluated by CCK-8 and EdU assays. The binding sites of miR-126-3p and PIK3R2 were predicted and verified. hCG-treated EECs were further transfected with miR-126-inhibitor for functional rescue experiments. hCG ameliorated endometrial receptivity in EID mice. Moreover, hCG promoted miR-126-3p and suppressed PIK3R2 in EID mice and EECs. miR-126-3p targeted PIK3R2. EEC proliferation was enhanced after hCG treatment but inhibited by miR-126-3p downregulation. Both in vivo and in vitro experiments validated that hCG activated the PI3K/Akt/eNOS pathway through the miR-126-3p/PIK3R2 axis. Collectively, hCG improves endometrial receptivity by activating the PI3K/Akt/eNOS pathway via regulating miR-126-3p/PIK3R2.

Circulating miRNAs in girls with abdominal obesity: miR-221-3p as a biomarker of response to weight loss interventions

BACKGROUND

Recent studies have associated several microRNAs (miRNAs) with childhood obesity and energy homeostasis, suggesting that an individual miRNA profile could be used as an early predictor to estimate the response to weight loss interventions in the design of precision nutrition.

OBJECTIVE

To investigate associations between the expression of circulating adiposity-related miRNAs and the response to a weight loss intervention.

METHODS

A total of 51 Spanish girls (age 7-16 years) with abdominal obesity underwent 8 weeks of a multidisciplinary intervention for weight loss. Participants were stratified into two groups in accordance with changes in body mass index (BMI) standard deviation score: low-responders (LR) and high-responders (HR). The expression of 39 circulating miRNAs (c-miRNAs) was evaluated in plasma of all subjects before the intervention.

RESULTS

Six miRNAs were differentially expressed between LR and HR. However, after adjustment for Tanner stage, the association was maintained only for miR-126-3p and miR-221-3p with a higher expression in HR group compared to LR group. After the intervention, miR-221-3p expression decreased in all subjects with a significant difference in the change within groups. However, changes in miR-126-3p levels were not significant. The expression of miR-221-3p was positively correlated with body weight, BMI and waist circumference, and negatively correlated with quantitative insulin sensitivity check index.

CONCLUSIONS

Bioinformatic analysis evidenced that miR-221-3p participates in several obesity-related pathways, and more interestingly, this miRNA targets several candidate genes to childhood obesity according to DisGeNet database. Thus, miR-221-3p could be used for predicting the response to a multidisciplinary intervention for weight loss in young girls.

MEK1/2 inhibitor inhibits neointima formation by activating miR-126-3p/ C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C motif chemokine receptor 4 (CXCR4) axis

Endothelial dysfunction is an initial and essential step in vascular-remodeling diseases, including atherosclerosis and neointima formation. During vascular remodeling, activated endothelial cells can release pro-inflammatory factors that promote phenotypic switching of vascular smooth muscle cells (VSMCs) to the proliferative phenotype. We previously reported that MEK1/2 inhibitor, U0126, has a protective effect on the development of atherosclerosis and vascular calcification. However, the effect of MEK1/2 inhibitors on neointimal formation and the underlying mechanism is not fully understood. We determined that MEK1/2 inhibitor reduced carotid artery ligation-induced neointimal formation, while increased collagen and elastin levels and vascular integrality. Mechanistically, MEK1/2 inhibitor or ERK1/2 siRNA increased miR-126-3p level in endothelial cells, thereby inhibiting expression of regular of G-protein signaling 16 (RGS16), a miR-126-3p target gene, to activate the C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C motif chemokine receptor 4 (CXCR4) signaling pathway. Accordingly, miR-126-3p was also increased by U0126 in serum and carotid artery. RGS16 was inhibited while CXCR4 and CXCL12 was increased by U0126 in neointimal areas, especially in the endothelium. Moreover, similar results were observed in atherosclerotic plaques of high-fat diet-fed apolipoprotein E deficiency (apoE^−/−) mice. In addition, vascular cell adhesion molecule 1 (VCAM-1), another miR-126-3p target gene, was reduced by U0126 in the neointimal areas, resulting reduced monocytes/macrophages accumulation. Taken together, our results indicate that MEK1/2 inhibitor can reduce neointima formation by activating endothelial miR-126-3p production to facilitate endothelium repair while reduce monocyte adhesion/infiltration.

Investigation of miR-126-3p loaded on adipose stem cell-derived exosomes for wound healing of full-thickness skin defects

OBJECTIVE

To investigate the function of miR-126-3p loaded on adipose stem cell (ADSC)-derived exosomes (ADSC-Exos) in wound healing of full-thickness skin defects.

METHODS

ADSCs transfected with miR-126-3p mimic, miR-126-3p inhibitor or pcDNA3.1-PIK3R2, or PKH26-marked ADSC-Exos were cultured with fibroblasts or human umbilical vein endothelial cells (HUVECs). The proliferation and migration rates of fibroblasts and angiogenesis of HUVECs were measured. Rats with full-thickness skin defects were injected with ADSC-Exos or exosomes extracted from ADSCs transfected with miR-126-3p inhibitor and the wound healing rates were measured. The wound bed, collagen deposition and angiogenesis in injured rats were assessed.

RESULTS

ADSC-Exos could be ingested by fibroblasts and HUVECs. Co-incubation with ADSCs or ADSC-Exos promoted the proliferation and migration of fibroblasts and angiogenesis of HUVECs, which was further enhanced by miR-126-3p overexpression. Inhibition of ADSC-Exos or miR-126-3p or PIK3R2 overexpression suppressed the proliferation and migration of fibroblasts and angiogenesis of HUVECs. ADSC-derived exosomal miR-126-3p increased wound healing rate, collagen deposition and newly formed vessels in injured rats.

CONCLUSION

ADSC-derived exosomal miR-126-3p promotes wound healing of full-thickness skin defects by targeting PIK3R2.

Expression Profiles of Circulating microRNAs in South African Type 2 Diabetic Individuals on Treatment

Aim: The influence of disease duration and anti-diabetic treatment on epigenetic processes has been described, with limited focus on interactions with microRNAs (miRNAs). miRNAs have been found to play key roles in the regulation of pathways associated with type 2 diabetes mellitus (T2DM), and expression patterns in response to treatment may further promote their use as therapeutic targets in T2DM and its associated complications. We therefore aimed to investigate the expressions of circulating miRNAs (miR-30a-5p, miR-1299, miR-182-5p, miR-30e-3p and miR-126-3p) in newly diagnosed and known diabetics on treatment, in South Africa.

Methods: A total of 1254 participants with an average age of 53.8years were included in the study and classified according to glycaemic status (974 normotolerant, 92 screen-detected diabetes and 188 known diabetes). Whole blood levels of miR-30a-5p, miR-1299, miR-182-5p, miR-30e-3p and miR-126-3p were quantitated using RT-qPCR. Expression analysis was performed and compared across groups.

Results: All miRNAs were significantly overexpressed in subjects with known diabetes when compared to normotolerant individuals, as well as known diabetics vs. screen-detected (p<0.001). Upon performing regression analysis, of all miRNAs, only miR-182-5p remained associated with the duration of the disease after adjustment for type of treatment (OR: 0.127, CI: 0.018–0.236, p=0.023).

Conclusion: Our findings revealed important associations and altered expression patterns of miR-30a-5p, miR-1299, miR-182-5p, miR-30e-3p and miR-126-3p in known diabetics on anti-diabetic treatment compared to newly diagnosed individuals. Additionally, miR-182-5p expression decreased with increasing duration of T2DM. Further studies are, however, recommended to shed light on the involvement of the miRNA in insulin signalling and glucose homeostasis, to endorse its use as a therapeutic target in DM and its associated complications.

Longitudinal Circulating Levels of miR-23b-3p, miR-126-3p and lncRNA GAS5 in HCC Patients Treated with Sorafenib

Human hepatocellular carcinoma (HCC) is the most frequent primary tumor of the liver and the third cause of cancer-related deaths. The multikinase inhibitor sorafenib is a systemic drug for unresectable HCC. The identification of molecular biomarkers for the early diagnosis of HCC and responsiveness to treatment are needed. In this work, we performed an exploratory study to investigate the longitudinal levels of cell-free long ncRNA GAS5 and microRNAs miR-126-3p and -23b-3p in a cohort of 7 patients during the period of treatment with sorafenib. We used qPCR to measure the amounts of GAS5 and miR-126-3p and droplet digital PCR (ddPCR) to measure the levels of miR-23b-3p. Patients treated with sorafenib displayed variable levels of GAS5, miR-126-3p and miR-23b-3p at different time-points of follow-up. miR-23b-3p was further measured by ddPCR in 37 healthy individuals and 25 untreated HCC patients. The amount of miR-23b-3p in the plasma of untreated HCC patients was significantly downregulated if compared to healthy individuals. The ROC curve analysis underlined its diagnostic relevance. In conclusion, our results highlight a potential clinical significance of circulating miR-23b-3p and an exploratory observation on the longitudinal plasmatic levels of GAS5, miR-126-3p and miR-23b-3p during sorafenib treatment.

LncRNA XIST is involved in rheumatoid arthritis fibroblast-like synoviocytes by sponging miR-126-3p via the NF-κB pathway

The role and mechanism of lncRNA XIST (XIST) in the development of rheumatoid arthritis (RA) was explored in this study. RT-qPCRs were performed to detect the expression of XIST and miR-126-3p in synovial tissues and cells. Target gene prediction and luciferase gene reporter assay were used to validate downstream target genes of XIST. MTT assay, EdU staining and Annexin V/PI staining were performed to explore the effects of XIST and miR-126-3p on cell proliferation and apoptosis. Western blotting analysis was used to detect the expression of related proteins. We found that the expression levels of XIST in tissues and cells were significantly higher than that in normal tissues and cells. Down-regulation of XIST could inhibit cell proliferation rate and increase apoptosis rate. Luciferase gene reporter assay showed that miR-126-3p was a downstream target gene of XIST. Overexpression of miR-126-3p significantly inhibited RA-FLS cell proliferation and induced RA-FLS cell apoptosis. In addition, down-regulation of XIST could increase the ratio of caspase-3 and Bax/Bcl-2. In addition, overexpression of miR-126-3p could inhibit the NF-κB signalling pathway by reducing the expression levels of p-p65 and p-IκBα in RA-FLS cells. In conclusion, down-regulation of XIST can inhibit the proliferation of synovial fibroblasts by increasing the expression levels of miR-126-3p/NF-κB, thereby inhibiting the occurrence and development of RA.

Maternal obesity during pregnancy leads to adipose tissue ER stress in mice via miR-126-mediated reduction in Lunapark

AIMS/HYPOTHESIS

Levels of the microRNA (miRNA) miR-126-3p are programmed cell-autonomously in visceral adipose tissue of adult offspring born to obese female C57BL/6J mice. The spectrum of miR-126-3p targets and thus the consequences of its dysregulation for adipocyte metabolism are unknown. Therefore, the aim of the current study was to identify novel targets of miR-126-3p in vitro and then establish the outcomes of their dysregulation on adipocyte metabolism in vivo using a well-established maternal obesity mouse model.

METHODS

miR-126-3p overexpression in 3T3-L1 pre-adipocytes followed by pulsed stable isotope labelling by amino acids in culture (pSILAC) was performed to identify novel targets of the miRNA. Well-established bioinformatics algorithms and luciferase assays were then employed to confirm those that were direct targets of miR-126-3p. Selected knockdown experiments were performed in vitro to define the consequences of target dysregulation. Quantitative real-time PCR, immunoblotting, histology, euglycaemic-hyperinsulinaemic clamps and glucose tolerance tests were performed to determine the phenotypic and functional outcomes of maternal programmed miR-126-3p levels in offspring adipose tissue.

RESULTS

The proteomic approach confirmed the identity of known targets of miR-126-3p (including IRS-1) and identified Lunapark, an endoplasmic reticulum (ER) protein, as a novel one. We confirmed by luciferase assay that Lunapark was a direct target of miR-126-3p. Overexpression of miR-126-3p in vitro led to a reduction in Lunapark protein levels and increased Perk (also known as Eif2ak3) mRNA levels and small interference-RNA mediated knockdown of Lunapark led to increased Xbp1, spliced Xbp1, Chop (also known as Ddit3) and Perk mRNA levels and an ER stress transcriptional response in 3T3-L1 pre-adipocytes. Consistent with the results found in vitro, increased miR-126-3p expression in adipose tissue from adult mouse offspring born to obese dams was accompanied by decreased Lunapark and IRS-1 protein levels and increased markers of ER stress. At the whole-body level the animals displayed glucose intolerance.

CONCLUSIONS/INTERPRETATION

Concurrently targeting IRS-1 and Lunapark, a nutritionally programmed increase in miR-126-3p causes adipose tissue insulin resistance and an ER stress response, both of which may contribute to impaired glucose tolerance. These findings provide a novel mechanism by which obesity during pregnancy leads to increased risk of type 2 diabetes in the offspring and therefore identify miR-126-3p as a potential therapeutic target.

Can Be miR-126-3p a Biomarker of Premature Aging? An Ex Vivo and In Vitro Study in Fabry Disease

Fabry disease (FD) is a lysosomal storage disorder (LSD) characterized by lysosomal accumulation of glycosphingolipids in a wide variety of cytotypes, including endothelial cells (ECs). FD patients experience a significantly reduced life expectancy compared to the general population; therefore, the association with a premature aging process would be plausible. To assess this hypothesis, miR-126-3p, a senescence-associated microRNA (SA-miRNAs), was considered as an aging biomarker. The levels of miR-126-3p contained in small extracellular vesicles (sEVs), with about 130 nm of diameter, were measured in FD patients and healthy subjects divided into age classes, in vitro, in human umbilical vein endothelial cells (HUVECs) “young” and undergoing replicative senescence, through a quantitative polymerase chain reaction (qPCR) approach. We confirmed that, in vivo, circulating miR-126 levels physiologically increase with age. In vitro, miR-126 augments in HUVECs underwent replicative senescence. We observed that FD patients are characterized by higher miR-126-3p levels in sEVs, compared to age-matched healthy subjects. We also explored, in vitro, the effect on ECs of glycosphingolipids that are typically accumulated in FD patients. We observed that FD storage substances induced in HUVECs premature senescence and increased of miR-126-3p levels. This study reinforces the hypothesis that FD may aggravate the normal aging process.

Downregulation of miR-126-3p expression contributes to increased inflammatory response in placental trophoblasts in preeclampsia

MiR-126-3p is a prototype of an endothelial miRNA and has protective effects on endothelial cells. However, little is known about the effects of miR-126-3p on placental trophoblasts. In the present study, we tested the hypothesis that aberrant miR-126-3p expression is present in preeclamptic placenta which contributes to increased inflammatory response in trophoblasts. Placentas were obtained immediately after delivery from normotensive and preeclamptic pregnancies. Villous tissue was either fixed with formalin or used for trophoblast isolation. Trophoblast miR-126-3p expression was assessed by in situ hybridization of formalin-fixed tissue sections and by RT-PCR in cultured syncytiotrophoblasts. Culture medium was collected for measurement of IL-6, TNFα, and 8-Isoprostane production by ELISA and total cellular protein was collected for evaluation of HIF1α expression by Western blot. Effects of overexpression of miR-126-3p in trophoblasts on cytokine production were tested by transfection of pre-mir-126, a precursor of miR-126, into primary isolated trophoblasts. We found that downregulation of miR-126-3p expression was associated with increased IL-6 and TNFα production in trophoblasts from preeclamptic placentas vs. normal placentas. Moreover, transient overexpression of miR-126-3p significantly reduced IL-6 and TNFα production in trophoblasts from both normal and preeclamptic placentas. We further found that increase in miR-126-3p expression not only suppressed hypoxia-induced increases in IL-6 and TNFα production, but also attenuated hypoxia-induced increases in HIF1α expression and 8-Isoprostane production in trophoblasts cultured under hypoxic condition. These results provide plausible evidence that downregulation of miR-126-3p expression reduces anti-inflammatory and anti-oxidative stress activities in placental trophoblasts in preeclampsia.

Underexpression of miR-126-3p in Patients with Cholangiocarcinoma

Objectives:

To evaluate the expression of miR-126-3p and its potential as a biomarker for cholangiocarcinoma (CCA) and to better understand the prognosis, comorbidities, and lifestyle habits associated with the disease.

Methods:

Fifty-nine individuals were distributed into either the study group (38 CCA patients) or the control group (21 individuals without liver diseases). Total RNA was extracted, cDNA synthesis was performed, and miR-126-3p expression was assessed using real-time PCR. For statistical analysis, alpha error was set at 5%.

Results:

MiR-126-3p was found to be underexpressed in the study group relative to the controls (0.42; P=0.001). Additionally, marked underexpression was found in the study group in when associated with smoking (0.28; P=0.0001), alcoholism (0.19; P=0.0001), hypertension (0.29; P=000.1), and diabetes (0.12; P=0.0003) relative to the controls. No association was found between miR-126-3p expression and tumor subtypes (iCCA=0.42; pCCA=0.45; dCCA=0.72; P=0.9155). A total of 67% of dCCA patients were event-free at 16 months of follow up, while both pCCA and iCCA exhibited event-free survival rates of 25%, though there was no significant difference between these subgroups (P=0.273).

Conclusion:

The underexpression of mir-126-3p is associated with cholangiocarcinoma and can be potentiated by alcoholism, hypertension, diabetes, and smoking, the latter of which is an independent risk factor for this cancer. Furthermore, dCCA patients exhibit higher survival rates relative to patients with pCCA and iCCA.

miR-126-3p contributes to parathyroid tumor angiogenesis

Tumors of the parathyroid glands are highly vascularized and display a microRNA (miRNA) profile divergent from normal parathyroid glands (PaNs). Angiogenic miRNAs, namely miR-126-3p, miR-126-5p, and miR-296-5p, have been found downregulated in parathyroid tumors. Here, we show that miR-126-3p expression levels are reduced in parathyroid adenomas (PAds; n = 12) compared with PaNs (n = 4). In situ hybridization (ISH) of miR-126-3p and miR-296-5p in 10 PAds show that miR-126-3p is expressed by endothelial cells lining the walls of great vessels and by cells within the thin stroma surrounding acinar structures. At variance, miR-296-5p was detectable in most PAd epithelial cells. Combining ISH for miR-126-3p with immunohistochemistry for the endothelial and mesenchymal markers CD34, CD31 and α-smooth muscle actin (αSMA), we could identify that miR-126-3p is localized in the αSMA-positive thin stroma. Further, miR-126-3p-expressing cells are enriched in the CD34-positive stromal cells surrounding epithelial cell acinar structures, a cellular pattern consistent with tumor-associated myofibroblasts (TAMs). In line with this, CD34-positive cells, sorted by FACS from PAds tissues, express miR-126-3p at higher levels than CD34-negative cells, suggesting that miR-126-3p downregulation promotes the endothelial-to-αSMA+ mesenchymal transition. In human mesenchymal stem cells derived from bone marrow (hBM-MSCs), a model of TAMs, the co-culture with PAds-derived cells for 5 days decreases miR-126-3p, while it increases VEGFA expression. At variance, adrenomedullin (ADM) expression is unaffected. Finally, overexpression of the miR-126-3p mimic in both hBM-MSCs and PAds-derived explants downregulates VEGFA expression levels. In conclusion, miR-126-3p is expressed by both endothelial cells and TAMs in PAds, and its downregulation promotes neoangiogenesis, possibly through VEGFA overexpression.

ERK1/2 inhibition reduces vascular calcification by activating miR-126-3p-DKK1/LRP6 pathway

Rationale: Vascular microcalcification increases the risk of rupture of vulnerable atherosclerotic lesions. Inhibition of ERK1/2 reduces atherosclerosis in animal models while its role in vascular calcification and the underlying mechanisms remains incompletely understood.

Methods: Levels of activated ERK1/2, DKK1, LRP6 and BMP2 in human calcific aortic valves were determined. ApoE deficient mice received ERK1/2 inhibitor (U0126) treatment, followed by determination of atherosclerosis, calcification and miR-126-3p production. C57BL/6J mice were used to determine the effect of U0126 on Vitamin D₃ (VD₃)-induced medial arterial calcification. HUVECs, HAECs and HASMCs were used to determine the effects of ERK1/2 inhibitor or siRNA on SMC calcification and the involved mechanisms.

Results: We observed the calcification in human aortic valves was positively correlated to ERK1/2 activity. At cellular and animal levels, U0126 reduced intimal calcification in atherosclerotic lesions of high-fat diet-fed apoE deficient mice, medial arterial calcification in VD₃-treated C57BL/6J mice, and calcification in cultured SMCs and arterial rings. The reduction of calcification was attributed to ERK1/2 inhibition-reduced expression of ALP, BMP2 and RUNX2 by activating DKK1 and LRP6 expression, and consequently inactivating both canonical and non-canonical Wnt signaling pathways in SMCs. Furthermore, we determined ERK1/2 inhibition activated miR-126-3p production by facilitating its maturation through activation of AMPKα-mediated p53 phosphorylation, and the activated miR-126-3p from ECs and SMCs played a key role in anti-vascular calcification actions of ERK1/2 inhibition.

Conclusions: Our study demonstrates that activation of miR-126-3p production in ECs/SMCs and interactions between ECs and SMCs play an important role in reduction of vascular calcification by ERK1/2 inhibition.

miR-126-3p contributes to sorafenib resistance in hepatocellular carcinoma via downregulating SPRED1

Background

Sorafenib can prolong the survival of patients with advanced hepatocellular carcinoma (HCC). However, drug resistance remains the main obstacle to improving its efficiency. This study aimed to explore the likely molecular mechanism of sorafenib resistance.

Methods

Differentially expressed microRNAs (miRNAs) related to sorafenib response were analyzed with the Limma package in R software. The expression levels of miR-126-3p and sprouty-related EVH1 domain-containing protein 1 (SPRED1) in HCC cells were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell viability and proliferation were detected with Cell Counting Kit-8 (CCK-8), EdU proliferation, and clone formation assays. Transwell assays were performed to measure cell migration and invasion. TargetScan, MicroRNA Target Prediction Database (miRDB), and StarBase v2.0 were used to predict the targets of miR-126-3p. SPRED1 was confirmed as a target gene of miR-126-3p by dual-luciferase reporter assay and Western blotting. Finally, the in vivo anti-tumor effect of LV-miR-126-3p inhibitor combined with sorafenib was evaluated via subcutaneous tumor models.

Results

HCC cells with high expression of miR-126-3p exhibited increased resistance to sorafenib. The results of bioinformatics analysis and the dual-luciferase reporter assay showed that miR-126-3p directly targeted SPRED1. The sensitivity of HCC cells to sorafenib was markedly enhanced by SPRED1 upregulation. Gain- and loss-of function experiments verified that miR-126-3p induced sorafenib resistance in HCC through downregulating SPRED1. Furthermore, the inhibition of miR-126-3p markedly increased the effectiveness of sorafenib against HCC in vivo. Mechanistically, our results suggested that miR-126-3p promoted sorafenib resistance via targeting SPRED1 and activating the ERK signaling pathway.

Conclusions

Our study demonstrates that regulating the miR-126-3p/SPRED1 axis might be a promising strategy for enhancing the antitumor effect of sorafenib in the treatment of HCC.

miR-126-3p and miR-16-5p as novel serum biomarkers for disease activity and treatment response in symptomatic dermographism

Symptomatic dermographism (SD) is the most common form of physical urticaria. So far no promising serum biomarkers for SD have been reported. Recently, microRNAs (miRNAs) have been reported to be serum biomarkers for chronic spontaneous urticaria. However, association of miRNAs with SD remains unclear. We enrolled 55 SD patients and 52 healthy controls in this study. We found that serum expressions of miR-126-3p and miR-16-5p were significantly downregulated in active SD patients and upregulated in remission. The area under the curve values of miR-126-3p (0.769) and miR-16-5p (0.789) showed significant ability to diagnostic SD. Serum level of vascular endothelial growth factor (VEGF)-A, a known target of the two miRNAs, was significantly increased in active SD patients and decreased in remission. Moreover, serum VEGF-A level was inversely correlated with expressions of miR-126-3p and miR-16-5p. Our findings indicate that miR-126-3p and miR-16-5p can serve as potential serum biomarkers for SD.

Hydrogen sulfide rescues high glucose-induced migration dysfunction in HUVECs by upregulating miR-126-3p

Diabetes (especially Type II) is one of the primary threats to cardiovascular health. Wound healing defects and vascular dysfunction are common in diabetic patients, and the primary cause of deterioration is sustained high plasma glucose. microRNA, a noncoding RNA, has regulatory functions that are critical to maintaining homeostasis. MicroRNA (miR)-126-3p is a potential diabetes biomarker and a proangiogenic factor, and its plasma level decreases in diabetic patients. Previous studies have revealed the proangiogenic character of the gasotransmitter hydrogen sulfide (H₂S). However, little is known about the relationship between H₂S and miR-126-3p when the extracellular glucose level is high, let alone their influences on deteriorated endothelial cell migration, a key component of angiogenesis, which is crucial for wound healing. Human umbilical vein endothelial cells (HUVECs) were treated with high glucose (33.3 mmol/L) or normal glucose (5.5 mmol/L) for 48 h. Affymetrix miRNA profiling and real-time PCR were used to validate the miRNA expression. An H₂S probe (HSip-1) was used to detect endogenous H₂S. Scratch wound-healing assays were used to evaluate HUVEC migration. The protein levels were quantified by Western blot. Both exogenous and endogenous H₂S could upregulate the miR-126-3p levels in HUVECs or muscle tissue. High glucose decreased the H₂S level and the protein expression of the H₂S-producing enzyme cystathionine γ-lyase (CSE) in HUVECs; however, the DNA methyltransferase 1 (DNMT1) protein level was upregulated. CSE overexpression not only increased the miR-126-3p level by decreasing the DNMT1 protein level but also rescued the deteriorated cell migration in HUVECs treated with high glucose. DNMT1 overexpression decreased the miR-126-3p level and inhibited the migration of HUVECs, whereas silencing DNMT1 improved cell migration. High glucose decreased the endogenous H₂S and miR-126-3p levels and increased the DNMT1 expression, thus inducing the migration dysfunction of HUVECs. Treatment with exogenous H₂S or the overexpression of the endogenously produced enzyme CSE would rescue this migration dysfunction through H₂S-DNMT1-miR-126-3p.

MiR-126-3p inhibits apoptosis and promotes proliferation by targeting phosphatidylinositol 3-kinase regulatory subunit 2 in porcine ovarian granulosa cells

Objective

Numerous studies have indicated that the apoptosis and proliferation of granulosa cells (GCs) are closely related to the normal growth and development of follicles and ovaries. Previous evidence has suggested that miR-126-3p might get involved in the apoptosis and proliferation of GCs, and phosphatidylinositol 3-kinase regulatory subunit 2 (PIK3R2) gene has been predicted as one target of miR-126-3p. However, the molecular regulation of miR-126-3p on PIK3R2 and the effects of PIK3R2 on porcine GCs apoptosis and proliferation remain virtually unexplored.

Methods

In this study, using porcine GCs as a cellular model, luciferase report assay, mutation and deletion were applied to verify the targeting relationship between miR-126-3p and PIK3R2. Annexin-V/PI staining and 5-ethynyl-2′-deoxyuridine assay were applied to explore the effect of PIK3R2 on GCs apoptosis and proliferation, respectively. Real-time quantitative polymerase chain reaction and Western Blot were applied to explore the regulation of miR-126-3p on PIK3R2 expression.

Results

We found that miR-126-3p targeted at PIK3R2 and inhibited its mRNA and protein expression. Knockdown of PIK3R2 significantly inhibited the apoptosis and promoted the proliferation of porcine GCs, and significantly down-regulated the mRNA expression of several key genes of PI3K pathway such as insulin-like growth factor 1 receptor (IGF1R), insulin receptor (INSR), pyruvate dehydrogenase kinase 1 (PDK1), and serine/threonine kinase 1 (AKT1).

Conclusion

MiR-126-3p might target and inhibit the mRNA and protein expressions of PIK3R2, thereby inhibiting GC apoptosis and promoting GC proliferation by down-regulating several key genes of the PI3K pathway, IGF1R, INSR, PDK1, and AKT1. These findings would provide great insight into further exploring the molecular regulation of miR-126-3p and PIK3R2 on the functions of GCs during the folliculogenesis in female mammals.

MicroRNA-126-3p Attenuates Intracerebral Hemorrhage-Induced Blood-Brain Barrier Disruption by Regulating VCAM-1 Expression

Background

miR-126 is closely related to the occurrence of various complications after intracerebral hemorrhage (ICH), but the molecular mechanism is not fully elucidated. This study aimed to explore the mechanism of miR-126-3p in alleviating brain injury after ICH.

Methods

Serum miR-126-3p levels were compared between patients with IHC and healthy controls. A rat model of ICH was generated by intracerebral injection of Type VII collagenase. The rats were intracerebral injected with miR-126-3p mimics or negative control miRNA. Rat brain microvascular endothelial cells (BMECs) were used as a cell model of blood-brain barrier (BBB), and validated by immunofluorescence staining of Factor VIII. The BBB permeability of BMECs after miR-126-3p antagomir transfection was determined by FITC-dextran 20 through a confluent BMECs layer (measured over 120 min). The binding site of miR-126-3p in the 3'UTR of VCAM-1 was predicated by TargetScan, and verified by dual luciferase reporter assay. The expression levels of miR-126-3p and vascular cell adhesion molecule-1 (VCAM-1) in rat brain tissues and BMECs were measured by real-time PCR or western blotting.

Results

Serum miR-126-3p level was markedly down-regulated in patients with ICH. The rats with ICH had decreased miR-126-3p levels in serum and hemorrhagic area, while those changes were reversed by the treatment with miR-126-3p mimic. VCAM-1 is a direct target of miR-126-3p, and VCAM-1 expression in hemorrhagic area was down-regulated by the administration of miR-126-3p mimic in rats. Inhibition of miR-126-3p by anti-miR126 treatment in BMECs resulted in barrier leakage.

Conclusion

miR-126-3p attenuates intracerebral hemorrhage-induced blood-brain barrier disruption, which is associated with down-regulated expression of VCAM-1 in hemorrhagic area.

miR-126-3p down-regulation contributes to dabrafenib acquired resistance in melanoma by up-regulating ADAM9 and VEGF-A

Background

Development of resistance to inhibitors of BRAF (BRAFi) and MEK (MEKi) remains a great challenge for targeted therapy in patients with BRAF-mutant melanoma. Here, we explored the role of miRNAs in melanoma acquired resistance to BRAFi.

Methods

miRNA expression in two BRAF-mutant melanoma cell lines and their dabrafenib-resistant sublines was determined using Affymetrix GeneChip® miRNA 3.1 microarrays and/or qRT-PCR. The effects of miR-126-3p re-expression on proliferation, apoptosis, cell cycle, ERK1/2 and AKT phosphorylation, dabrafenib sensitivity, invasiveness and VEGF-A secretion were evaluated in the dabrafenib-resistant sublines using MTT assays, flow cytometry, immunoblotting, invasion assays in Boyden chambers and ELISA. ADAM9, PIK3R2, MMP7 and CXCR4 expression in the sensitive and dabrafenib-resistant cells was determined by immunoblotting. Small RNA interference was performed to investigate the consequence of VEGFA or ADAM9 silencing on proliferation, invasiveness or dabrafenib sensitivity of the resistant sublines. Long-term proliferation assays were carried out in dabrafenib-sensitive cells to assess the effects of enforced miR-126-3p expression or ADAM9 silencing on resistance development. VEGF-A serum levels in melanoma patients treated with BRAFi or BRAFi+MEKi were evaluated at baseline (T0), after two months of treatment (T2) and at progression (TP) by ELISA.

Results

miR-126-3p was significantly down-regulated in the dabrafenib-resistant sublines as compared with their parental counterparts. miR-126-3p replacement in the drug-resistant cells inhibited proliferation, cell cycle progression, phosphorylation of ERK1/2 and/or AKT, invasiveness, VEGF-A and ADAM9 expression, and increased dabrafenib sensitivity. VEGFA or ADAM9 silencing impaired proliferation and invasiveness of the drug-resistant sublines. ADAM9 knock-down in the resistant cells increased dabrafenib sensitivity, whereas miR-126-3p enforced expression or ADAM9 silencing in the drug-sensitive cells delayed the development of resistance. At T0 and T2, statistically significant differences were observed in VEGF-A serum levels between patients who responded to therapy and patients who did not. In responder patients, a significant increase of VEGF-A levels was observed at TP versus T2.

Conclusions

Strategies restoring miR-126-3p expression or targeting VEGF-A or ADAM9 could restrain growth and metastasis of dabrafenib-resistant melanomas and increase their drug sensitivity. Circulating VEGF-A is a promising biomarker for predicting patients’ response to BRAFi or BRAFi+MEKi and for monitoring the onset of resistance.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1238-4) contains supplementary material, which is available to authorized users.

MiR-126-3p promotes the cell proliferation and inhibits the cell apoptosis by targeting TSC1 in the porcine granulosa cells

In mammalian ovaries, many studies demonstrated that the proliferation and apoptosis of granulosa cells are involved in folliculogenesis. Previous evidence suggests that miR-126-3p might get involved in the proliferation and apoptosis of granulosa cells, and tuberous sclerosis complex 1 (TSC1) gene was predicted as one target of miR-126-3p, and moreover, granulosa cell-specific TSC1 knockout stimulated folliculogenesis in mice. However, the molecular regulation of miR-126-3p on TSC1 and its effects on cell proliferation and apoptosis remain virtually unexplored in granulosa cells. Using porcine granulosa cells as a model, the luciferase report assay, mutation, deletion, Annexin-V/PI staining, and EdU assays were applied to investigate the molecular mechanism for miR-126-3p regulating the expression of TSC1 and their effects on the cell proliferation and apoptosis. We found that miR-126-3p showed a positive effect on cell proliferation and a negative effect on cell apoptosis in porcine granulosa cells, and knockdown of TSC1 significantly promoted cell proliferation and significantly inhibited cell apoptosis in porcine granulosa cells. Furthermore, miR-126-3p might target and repress the expressions of TSC1 at the post-transcriptional level, thereby promoting cell proliferation and inhibiting cell apoptosis of granulosa cells. These findings would provide of great insight in further exploring the molecular regulation of miR-126-3p and TSC1 on the functions of granulosa cells during the folliculogenesis in mammals.

Transplantation of Endothelial Progenitor Cells Overexpressing miR-126-3p Improves Heart Function in Ischemic Cardiomyopathy

BACKGROUND

In a previous study, a low level of miR-126-3p in endothelial progenitor cells (EPCs) was linked to the outcome of ischemic cardiomyopathy (ICM) patients. However, it remains unclear whether transplantation with miR-126-3p-overexpressing EPCs (MO-EPCs) can improve the cardiac function of ICM animal models. Methods and Results: miR-126-3p overexpression by lentiviral vector significantly increased migration and tube-like structures of EPCs from ICM patients. MO-EPCs or non-modified EPCs (NM-EPCs) were transplanted into nude rats with ICM induced by coronary artery ligation. MO-EPC transplantation increased capillary density and EPC survival rate in myocardial tissues of nude rats. Cytokines were also assessed by antibody array and real-time RT-PCR. G-CSF, VEGF-A, IL-3, IL-10, IGF-1, angiogenin, HGF, TIMP-1 and TIMP-2 were upregulated, and IL-8, MCP-1, MCP-2, TNF-α, TNF-β and MIP-1β were downregulated after miR-126-3p overexpression in EPCs. The same results were obtained in infarction tissues of nude rats after MO-EPC transplantation. Eight weeks after MO-EPC transplantation, left ventricular function improved significantly with clearly decreased infarction size, increased anterior wall thickness, and inhibition of inflammation compared with the results for NM-EPC transplantation. However, MO-EPC transplantation showed no increase in survival time of nude rats with ICM during 8 weeks of observation.

CONCLUSIONS

miR-126-3p can restore the biology of EPCs from ICM patients. Moreover, MO-EPC transplantation improves cardiac function effectively, representing a promising future treatment for ICM.

Serum miR-126-3p level is down-regulated in sepsis patients

BACKGROUND

Endothelial injury is part of the pathogenesis of sepsis. The microRNA-126 (miR-126) was previously identified as an endothelial biomarker and is known to play a critical role in preserving endothelial cell integrity. However, the role of miRNA-126 in sepsis is unclear.

METHOD

Blood samples were collected from sepsis patients at the first Affiliated Hospital of Sun Yat-sen University within 24 h (n = 60) and on day 7 (n = 51) after diagnosis, and once from control subjects (n = 46). MiR-126-3p expression was evaluated by quantitative real-time PCR. The miR-126-3p level was correlated with clinical data and a set of routine and experimental biomarkers. The outcome of sepsis patients was determined by follow-up at 28 days after collection of blood samples on day 7.

RESULT

MiR-126-3p level was significantly downregulated in sepsis patients 24 h after diagnosis compared with control subjects. Degree of downregulation of serum miR-126-3p correlated with the severity of sepsis. To determine the diagnostic accuracy of miR-126-3p, the receiver operating characteristic (ROC) was performed and the AUC of miR-126-3p was 0.735. Furthermore, serum miR-126-3p concentration at this time point was correlated with the expression markers of systemic inflammation, bacterial infection, and renal and hepatic dysfunction. However, serum miR-126-3p level on day 7 day did not differ between surviving sepsis patients and those who died.

CONCLUSION

These results indicate that miR-126-3p could be a diagnostic biomarker for sepsis.

MicroRNA-126-3p suppresses cell proliferation by targeting PIK3R2 in Kaposi's sarcoma cells

Kaposi's sarcoma is a highly vascular tumor of lymphatic endothelial origin. Many deregulated miRNAs, including miR-126-3p, have been identified in Kaposi's sarcoma tissues. miR-126-3p is the most highly endothelial-specific miRNA that regulates vascular integrity and angiogenesis. In this study, we aimed to determine the effect of miR-126-3p on Kaposi's sarcoma cells through transfection of a miRNA mimic and inhibitor. Moreover, we searched the target gene (PIK3R2) of miR-126-3p using bioinformatics software and further verified PIK3R2 using luciferase reporter assays, Real-time quantitative PCR (qRT-PCR) and western blot. The results demonstrated that miR-126-3p inhibited cell proliferation, arrested cell cycle progression, induced cell apoptosis, and inhibited cell invasion of SLK cells. The bioinformatics analysis and luciferase reporter assay revealed that PIK3R2 mRNA is a direct target of miR-126-3p. Moreover, the level of expression of the PIK3R2 gene was downregulated in SLK cells transfected with miR-126-3p siRNAs. Therefore, our data demonstrated that miR-126-3p is a tumor suppressor miRNA that acts by targeting PIK3R2 in Kaposi's sarcoma cells. These findings contribute to our understanding of the molecular mechanisms underlying Kaposi's sarcoma.

Anti-TNF-α treatment modulates SASP and SASP-related microRNAs in endothelial cells and in circulating angiogenic cells

Endothelial cell senescence is characterized by acquisition of senescence-associated secretory phenotype (SASP), able to promote inflammaging and cancer progression. Emerging evidence suggest that preventing SASP development could help to slow the rate of aging and the progression of age-related diseases, including cancer. Aim of this study was to evaluate whether and how adalimumab, a monoclonal antibody directed against tumor necrosis factor-α (TNF-α), a major SASP component, can prevent the SASP. A three-pronged approach has been adopted to assess the if adalimumab is able to: i) modulate a panel of classic and novel senescence- and SASP-associated markers (interleukin [IL]-6, senescence associated-β-galactosidase, p16/Ink4a, plasminogen activator inhibitor 1, endothelial nitric oxide synthase, miR-146a-5p/Irak1 and miR-126-3p/Spred1) in human umbilical vein endothelial cells (HUVECs); ii) reduce the paracrine effects of senescent HUVECs' secretome on MCF-7 breast cancer cells, through wound healing and mammosphere assay; and iii) exert significant decrease of miR-146a-5p and increase of miR-126-3p in circulating angiogenic cells (CACs) from psoriasis patients receiving adalimumab in monotherapy.TNF-α blockade associated with adalimumab induced significant reduction in released IL-6 and significant increase in eNOS and miR-126-3p expression levels in long-term HUVEC cultures.A significant reduction in miR-146a-5p expression levels both in long-term HUVEC cultures and in CACs isolated from psoriasis patients was also evident. Interestingly, conditioned medium from senescent HUVECs treated with adalimumab was less consistent than medium from untreated cells in inducing migration- and mammosphere- promoting effects on MCF-7 cells.Our findings suggest that adalimumab can induce epigenetic modifications in cells undergoing senescence, thus contributing to the attenuation of SASP tumor-promoting effects.

Elevated circulating miR-126-3p expression in patients with acute myocardial infarction: its diagnostic value

Acute myocardial infarction (AMI) therapy has not remarkably improved due to delay in the diagnosis to a great extent. Circulating microRNAs have shown some potential for diagnosis of cardiovascular diseases. The aim of this study was to estimate the diagnostic value of circulating miR-126-3p for AMI. In our study, circulating miR-126-3p levels were determined by quantitative polymerase chain reaction and the results showed it was 106-fold higher than that in controls, and elevated miR-126-3p was associated with aging through logistic correlation analyses. Receiver-operator characteristic curve was used to evaluate the sensitivity and specificity of miR-126-3p for diagnosis of AMI, indicating that its diagnostic effect was superior to the current clinical markers such as CK, CK-MB, hs-TnI, and MYO. Our results indicate that miR-126-3p in circulation is a potential novel diagnostic biomarker for AMI.

MicroRNA-126-3p attenuates blood-brain barrier disruption, cerebral edema and neuronal injury following intracerebral hemorrhage by regulating PIK3R2 and Akt

MiR-126, a microRNA implicated in blood vessel integrity, angiogenesis and vascular inflammation, is markedly decreased in the sera of patients with intracerebral hemorrhage (ICH). The current study aims to evaluate the potential therapeutic effect of miR-126-3p on brain injuries in a rat model of collagenase-induced ICH. Intracerebroventricular administration of a miR-126-3p mimic significantly alleviated behavioral defects 24 h after ICH, as examined by paw placement and corner tests. ICH led to increased blood-brain barrier (BBB) permeability and cerebral edema, both of which were attenuated by miR-126-3p mimic. Treatment with miR-126-3p mimic reduced the numbers of myeloperoxidase (MPO)-positive, OX42-positive, Fluoro Jade B (FJB)-positive and NEUN/TUNEL double-positive cells around the hematoma, implying that miR-126-3p inhibited neutrophil infiltration, microglial activation and neuronal apoptosis following hemorrhage. In addition, miR-126-3p mimic suppressed the upregulation of phosphoinositide-3-kinase regulatory subunit 2 (PIK3R2) in the perihematomal area and maintained the activation of Akt. Furthermore, in vitro assays confirmed upregulation of PIK3R2 upon knockdown of miR-126-3p in rat brain microvascular endothelial cells (BMECs), and silencing of miR-126-3p resulted in impaired BMEC barrier permeability and reversed vascular endothelial growth factor (VEGF)- and angiopoietin-1 (Ang-1)-induced activation of Akt and inhibition of BMEC apoptosis. In summary, our results suggest that exogenous miR-126-3p may alleviate BBB disruption, cerebral edema and neuronal injury following ICH by targeting PIK3R2 and the Akt signaling pathway in brain vascular endothelium.

The association of miR-126-3p, miR-126-5p and miR-664-3p expression profiles with outcomes of patients with metastatic colorectal cancer treated with bevacizumab

MicroRNAs regulate the expression of genes involved in several important cancer-related processes including cell adhesion, proliferation, and tumour angiogenesis. Bevacizumab is routinely used in the treatment of patients with metastatic colorectal cancer, but, so far, no reliable biomarker predicting response to bevacizumab has been established. The aim of our retrospective study was to evaluate the association of miR-126-3p, miR-126-5p and miR-664-3p tumour expression levels with outcomes of patients with metastatic colorectal cancer treated with bevacizumab. The study included 63 patients. For the assessment of microRNA expression, gene-specific TaqMan assays were used. The median progression-free survival and overall survival for patients with low tumour expression of miR-126-3p were 8.8 and 20.6 months versus 13.5 months and median overall survival was not reached for patients with high expression ( p = 0.0064 and p = 0.0027), respectively. The median progression-free survival and overall survival for patients with low tumour expression of miR-126-5p were 9.0 and 22.2 months versus 12.0 and 23.4 months for patients with high expression ( p = 0.2113 and 0.6858), respectively. The median progression-free survival and overall survival for patients with low tumour expression of miR-664-3p were 9.1 and 22.5 months versus 8.8 and 23.4 months for patients with high expression ( p = 0.2542 and p = 0.1922), respectively. The multivariable Cox proportional hazards model revealed that miR-126-3p expression was significantly associated with progression-free survival (hazard ratio = 0.28, p = 0.0053) and also with overall survival (hazard ratio = 0.18, p = 0.0046). In conclusion, the results of this study suggest that the expression of miR-126-3p in the tumour tissue was associated with outcome of metastatic colorectal cancer patients treated with bevacizumab.

Deregulation of miR-126-3p in basal-like breast cancers stroma and its clinical significance

INTRODUCTION

The aim of this study was to investigate miR-126-3p expression in stroma and tumor cells of basal-like breast cancer tissues, in an effort to elucidate the potential effect of miR-126-3p on tumor microenvironment and progress of basal-like breast cancer.

METHODS

Expression levels of miR-126-3p in 33 paired basal-like breast cancer tissues were assayed by real-time quantitative PCR. Tumor cells and normal epithelial cell were isolated from ten paired basal-like breast cancer tissues and matched adjacent tissues, separately, using laser capture microdissect(LCM)-based PCR method. Further validated in larger sets were assayed by tissue microarrays (TMA)-based ISH method.

RESULTS

MiR-126-3p expression level had no significant differences between basal-like breast cancer subtypes and matched adjacent tissues. However, a decreasing trend of miR-126-3p expression can be found in tumor cells of basal-like subtype, compared with matched adjacent tissues, using LCM-based PCR. Using TMA method, miR-126-3p expression level was the lowest in stroma of basal-like breast cancers among four subtypes (χ2=10.55, P=0.01), and was increasing in stroma of breast cancers compared with fibroadenomas. Furthermore, strong miR-126-3p expression in stroma is significantly associated with HER-2 expression (χ2=4.70, P=0.03) and Ki-67 index. (χ2=4.84, P=0.03), which suggested a potential prognostic value of miR-126-3p in stroma of breast cancer. However, miR-126-3p expression in tumor cells derived from different subtypes hadn't significant clinical values in this study.

CONCLUSIONS

the miR-126-3p expression level in breast cancer stroma was associated with different intrinsic subtypes and its correlation with hormone receptor and Ki-67 index shed light on the potential clinical prognostic value of miR-126-3p, in the field of specific breast cancer subtypes.