miR-155 Levels Research Articles

Bidirectional negative feedback actions of DNMT3A and miR-145 in regulating autophagy in cardiac fibroblasts and affecting myocardial fibrosis.

Epigenetic regulation has crucial implications for myocardial fibrosis. It has been reported that autophagy, regulated by miR-145, is implicated in the proliferation and fibrosis of cardiac fibroblasts (CFs). However, how it works during the process remains unclear. This study explored the exact effects of epigenetic regulation of miR-145 expression on autophagy, proliferation, and fibrosis of CFs. To examine the expression levels of myocardial fibrosis markers (α-SMA and collagen I), autophagy-related proteins (LC3I, LC3II, p62), DNMT3A, and miR-145, qRT-PCR and western blot were employed. And the proliferation of CFs was detected by CCK-8 and ErdU. As for the determination of the binding relationship between DNMT3A and miR-145, dual-luciferase assay was conducted. Next, the detection of the methylation level of the pre-miR-145 promoter region was completed by MSP. And the verification of the effect of the DNMT3A/miR-145 axis on myocardial fibrosis was accomplished by constructing mouse myocardial infarction (MI) models based on the ligation of the left anterior descending method. In TGF-β1-activated CFs, remarkable up-regulation of DNMT3 and considerable down-regulation of miR-145 were observed. And further experiments indicated that DNMT3A was able to down-regulate miR-145 expression by maintaining the hypermethylation level of the pre-miR-145 promoter region. In addition, DNMT3A expression could be directly targeted and negatively modulated by miR-145. Moreover, in vitro cell experiments and mouse MI models demonstrated that DNMT3A overexpression could inhibit autophagy, and promote cell proliferation and fibrosis of CFs. However, this kind of effect could be reversed by miR-145 overexpression. In summary, myocardial fibroblast autophagy can be regulated by bidirectional negative feedback actions of DNMT3A and miR-145, thus affecting myocardial fibrosis. This finding will provide a potential target for the clinical treatment of myocardial fibrosis.

Differential Expression of miR-146 and miR-155 in Active and Latent Tuberculosis Infection.

Tuberculosis (TB) is one of the leading causes of death worldwide. Besides, one-third of the world population is infected with Mycobacterium tuberculosis (MTB) while staying clinically asymptomatic; the situation is called latent TB infection (LTBI). MiR-21, miR-31, miR-146a, and miR-155 play an important role in many immune and inflammatory pathways. In the present study the expression levels of MiR-21, miR-31, miR-146a, and miR-155 in peripheral blood mononuclear cells (PBMCs) from patients with active TB, latently infected individuals (LTBI), and healthy controls (HC) were investigated. Participants were recruited at the Bouali Hospital, Zahedan University of Medical Sciences, Zahedan, Iran from 2010 to 2011. PBMCs were stimulated with PPD before RNA extraction. TaqMan RT-qPCR assay was used to analyze the expression levels of miRNAs. The results indicated no significant differences in the expression of miR-21 and miR-31 between different groups; however, in patients with active TB, the expression of miR-21 (P=0.03) and miR-31 (P=0.04) were significantly increased after stimulation with PPD compared to the unstimulated condition. The expression of miR-146 in response to PPD in both LTBI (P=0.02) and TB (P=0.03) groups compared to the HC group was increased. No significant differences were found in the expression level of miR-155 in response to PPD between LTBI and HC groups. However, the fold change was significantly higher in the TB group in comparison with the HC (P=0.03) and LTBI (P=0.05) groups. The results confirm the main role of miR-146 and miR-155 in TB infection and suggest a role for miR-146 and miR-155 as infection and activation markers in tuberculosis infection, respectively.

Lower Plasma miR-223 Level Is Associated with Clopidogrel Resistance in Acute Coronary Syndrome: A Systematic Review and Meta-Analysis.

To evaluate the relationship between the plasma miR-223 expression level and clopidogrel resistance in acute coronary syndrome (ACS) patients. We performed a search for publications using online databases including PubMed, EMBASE, Cochrane Library, and Chinese Databases (CNKI database, Weipu database, and Wanfang database) from the inception of the databases to June 18, 2023, to identify studies reporting the relationship between the plasma miR-223 level and clopidogrel resistance in ACS patients. Two researchers independently searched and screened to ensure the consistency of the results and assess the quality of the included studies according to the Newcastle-Ottawa scale. A fixed-effects model was used for pooling data with STATA 14.0. Four articles including 399 Chinese ACS patients were eligible for the meta-analysis. Low plasma miR-223 levels were independently correlated with clopidogrel resistance in Chinese ACS patients (OR 0.58, 95% CI: 0.33-1.04). Lower plasma miR-223 levels are associated with clopidogrel resistance in Chinese ACS patients, suggesting that miR-223 may be a potential diagnostic biomarker of clopidogrel resistance.

Correlation between Circulating miR-16, miR-29a, miR-144 and miR-150, and the Radiotherapy Response and Survival of Non-Small-Cell Lung Cancer Patients.

Despite the success of current therapy concepts, patients with advanced non-small-cell lung cancer (NSCLC) still have a very poor prognosis. Therefore, biological markers are urgently needed, which allow the assessment of prognosis, or prediction of the success of therapy or resistance in this disease. Circulating microRNAs (miRs) have potential as biomarkers for the prognosis and prediction of response to therapy in cancer patients. Based on recent evidence that circulating miR-16, miR-29a, miR-144 and miR-150 can be regulated by ionizing radiation, the concentration of these four miRs was assessed in the plasma of NSCLC patients at different time points of radiotherapy by digital droplet PCR (ddPCR). Furthermore, their impact on patients' prognosis was evaluated. The mean plasma levels of miR-16, miR-29a, miR-144 and miR-150 significantly differed intra- and inter-individually, and during therapy in NSCLC patients, but showed a strong positive correlation. The individual plasma levels of miR-16, miR-29a and miR-144 had prognostic value in NSCLC patients during or at the end of radiotherapy in Cox's regression models. NSCLC patients with low levels of these three miRs at the end of radiotherapy had the worst prognosis. However, miR-150 plasma levels and treatment-dependent changes were not predictive. In conclusion, circulating miR-16, miR-29a and miR-144, but not miR-150, have a prognostic value in NSCLC patients undergoing radiotherapy.

XPO1 mutations identify early-stage CLL characterized by shorter time to first treatment and enhanced BCR signalling.

Here we evaluated the epigenomic and transcriptomic profile of XPO1 mutant chronic lymphocytic leukaemia (CLL) and their clinical phenotype. By ATAC-seq, chromatin regions that were more accessible in XPO1 mutated CLL were enriched of binding sites for transcription factors regulated by pathways emanating from the B-cell receptor (BCR), including NF-κB signalling, p38-JNK and RAS-RAF-MEK-ERK. XPO1 mutant CLL, consistent with the chromatin accessibility changes, were enriched with transcriptomic features associated with BCR and cytokine signalling. By combining epigenomic and transcriptomic data, MIR155HG, the host gene of miR-155, and MYB, the transcription factor that positively regulates MIR155HG, were upregulated by RNA-seq and their promoters were more accessible by ATAC-seq. To evaluate the clinical impact of XPO1 mutations, we investigated a total of 957 early-stage CLL subdivided into 3 independent cohorts (N = 276, N = 286 and N = 395). Next-generation sequencing analysis identified XPO1 mutations as a novel predictor of shorter time to first treatment (TTFT) in all cohorts. Notably, XPO1 mutations maintained their prognostic value independent of the immunoglobulin heavy chain variable status and early-stage prognostic models. These data suggest that XPO1 mutations, conceivably through increased miR-155 levels, may enhance BCR signalling leading to higher proliferation and shorter TTFT in early-stage CLL.

MiRNAs: novel noninvasive biomarkers as diagnostic and prognostic tools in neonatal sepsis

The study aimed to assess the diagnostic and prognostic value of 3 specific microRNAs (miRNAs) in early-onset neonatal sepsis (NS). We examined miR-1, miR-124, and miR-34a in 70 NS patients upon admission and compared them to 70 healthy controls by RT-PCR. The main finding of the study was the difference in miRNA expression levels between NS patients and controls. Higher expression levels of miR-1 and miR-124 were significantly associated with NS, while miR-34a expression was reduced. Among the studied miRNAs, miR-34a exhibited the highest specificity (97%) as a confirmatory test for NS. In the multivariate model, miR-1 and miR-124 were found to be significant predictors of disease progression or mortality. Overall, the study suggests that miR-1, miR-124, and miR-34a could serve as potential biomarkers for diagnosing and predicting outcomes in early-onset NS.

Increased small extracellular vesicle levels and decreased miR-126 levels associated with atrial fibrillation and coexisting diabetes mellitus.

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia. Diabetes mellitus (DM) is one of the risk factors for the development of stroke and thromboembolism in patients with AF. Early identification may reduce the incidence of complications and mortality in AF patients. AF patients with DM have different pattern of small extracellular vesicle (sEV) levels and sEV-derived microRNA (miRNA) expression compared with those without DM. We compared sEV levels and sEV-miRNA expression in plasma from AF patients with and without DM using nanoparticle tracking analysis and droplet digital polymerase chain reaction, respectively. We observed a significant increase in total sEV levels (p = .004) and a significant decrease in sEV-miR-126 level (p = .004) in AF patients with DM. Multivariate logistic regression analysis revealed a positive association between total sEV levels and AF with DM (p = .019), and a negative association between sEV-miR-126 level and AF with DM (p = .031). The combination of clinical data, total sEVs, and sEV-miR-126 level had an area under the curve of 0.968 (p < .0001) for discriminating AF with DM, which was shown to be significantly better than clinical data analysis alone (p = .0368). These results suggest that an increased level of total sEV and a decreased sEV-miR-126 level may play a potential role in the pathophysiology and complications of AF with DM, especially endothelial dysfunction, and can be considered as an applied biomarker for distinguishing between AF with and without DM.

MicroRNA expression as a diagnostic parameter in early endometrial cancer

ObjectivesMicroRNAs (miRNAs) have emerged as biomarkers that showed strong diagnostic potential in various diseases, including cancer. This study aimed to estimate the expression and diagnostic potential of miRNAs (miR-200a, miR-21,...

MicroRNAs miR-16 and miR-519 control meningioma cell proliferation via overlapping transcriptomic programs shared with the RNA-binding protein HuR.

Meningiomas are the most common type of primary central nervous system tumors. In about 80% cases, these tumors are benign and grow very slowly, but the remainder 20% can unlock higher proliferation rates and become malignant. In this study we examined two miRs, miR-16 and miR-519, and evaluated their role in tumorigenesis and cell growth in human meningioma. A cohort of 60 intracranial grade 1 and grade 2 human meningioma plus 20 healthy meningeal tissues was used to quantify miR-16 and miR-519 expressions. Cell growth and dose-response assays were performed in two human meningioma cell lines, Ben-Men-1 (benign) and IOMM-Lee (aggressive). Transcriptomes of IOMM-lee cells were measured after both miR-mimics transfection, followed by integrative bioinformatics to expand on available data. In tumoral tissues, we detected decreased levels of miR-16 and miR-519 when compared with arachnoid cells of healthy patients (miR-16: P=8.7e-04; miR-519: P=3.5e-07). When individually overexpressing these miRs in Ben-Men-1 and IOMM-Lee, we observed that each showed reduced growth (P<0.001). In IOMM-Lee cell transcriptomes, downregulated genes, among which ELAVL1/HuR (miR-16: P=6.1e-06; miR-519:P=9.38e-03), were linked to biological processes such as mitotic cell cycle regulation, pre-replicative complex, and brain development (FDR<1e-05). Additionally, we uncovered a specific transcriptomic signature of miR-16/miR-519-dysregulated genes which was highly enriched in HuR targets (>6-fold; 79.6% of target genes). These results were confirmed on several public transcriptomic and microRNA datasets of human meningiomas, hinting that the putative tumor suppressor effect of these miRs is mediated, at least in part, via HuR direct or indirect inhibition.

Changes and Clinical Value of Serum miR-24 and miR-223 Levels in Patients with Severe Pneumonia.

Severe pneumonia progresses rapidly, so early assessment of the severity and prognosis is crucial for reducing mortality rates. We explore the role of serum microRNA-24 (miR-24) and microRNA-223 (miR-223) in the prognosis of severe pneumonia. There were a total of 96 patients with general pneumonia, 94 patients with severe pneumonia, and 93 healthy people, who were enrolled in this study. The levels of serum miR-24 and miR-223 were detected by real-time fluorescent quantitative PCR in all groups. The serum miR-223 level in the severe group was higher than that in the common group and the control group, and the miR-24 level was lower than that in the common group and the control group (P<0.05). The serum miR-223 levels and APACHEII scores in the death group were higher than those in the survival group on the first, third, and seventh day after admission, while the miR-24 levels were lower than those in the survival group (P<0.05). The proportion of patients with mechanical ventilation in the death group was higher than that in the survival group (P<0.05). The level of serum miR-24 was negatively correlated with APACHEII score and mechanical ventilation in patients who died of severe pneumonia (P<0.05), and miR-223 was positively correlated with APACHEII score and mechanical ventilation (P<0.05). The AUC predicted by serum miR-24, miR-223, and APACHEII scores alone and jointly were 0.867, 0.839, 0.791, and 0.952, respectively. MiR-24 and miR-223 are protective and independent risk factors for mortality in severe pneumonia patients, respectively (P<0.05). MiR-24 was a protective factor affecting the death of patients with severe pneumonia, and miR-223 was an independent risk factor affecting the death of patients with severe pneumonia (P<0.05). The combination of serum miR-24 and miR-223 levels on the first day after admission and APACHEII score can effectively predict prognosis.

In chronic spontaneous urticaria, IgE and C-reactive protein are linked to distinct microRNAs and interleukin-31.

Chronic spontaneous urticaria (CSU) is a common and disabling disease. Assessments of IgE and C-reactive protein (CRP) are recommended in the diagnostic work-up, but the role and clinical relevance of these biomarkers are not well characterized. Moreover, it remains unknown if elevated levels of IgE or CRP are linked to CSU microRNA (miRNA) signatures or interleukin 31 (IL-31). We measured IgE and CRP serum levels in 47 CSU patients (and 45 healthy controls) and determined CSU disease activity using the urticaria activity score (UAS7). Expression levels of miR-155 and miR-221 were assessed by RT-PCR, and IL-31 levels were determined by ELISA. Total IgE and CRP levels were independently increased in CSU patients. IgE and CRP levels were highest and lowest in patients with high and mild disease activity. IgE levels correlated with miR-155 levels, whereas CRP levels correlated with miR-221 levels. miR-155 and miR-221 were significantly overexpressed in CSU patients. ROC analyses linked miRNA-155 and CSU with a sensitivity of 79% and specificity of 87%, and miRNA-221 and CSU with a sensitivity of 75% and specificity of 91%. High CRP and miR-221 expression levels were linked to elevated levels of IgG anti-TPO and IL-31. IgE and CRP are useful biomarkers for disease activity in CSU, with distinct miRNA profiles. High CRP and miR-221 levels may point to autoimmune CSU and a role for IL-31.

Plasma miR-153 and miR-223 levels as potential biomarkers in Parkinson's disease

Plasma miR-153 and miR-223 levels as potential biomarkers in Parkinson's disease

Long-Term LDL-Apheresis Treatment and Dynamics of Circulating miRNAs in Patients with Severe Familial Hypercholesterolemia.

Lipoprotein apheresis (LA) is a therapeutic option for patients with severe hypercholesterolemia who have persistently elevated LDL-C levels despite attempts at drug therapy. MicroRNAs (miRNAs), important posttranscriptional gene regulators, are involved in the pathogenesis of atherosclerosis. Our study aimed to monitor the dynamics of twenty preselected circulating miRNAs in patients under long-term apheresis treatment. Plasma samples from 12 FH patients (men = 50%, age = 55.3 ± 12.2 years; mean LA overall treatment time = 13.1 ± 7.8 years) were collected before each apheresis therapy every sixth month over the course of four years of treatment. Eight complete follow-up (FU) samples were measured in each patient. Dynamic changes in the relative quantity of 6 miRNAs (miR-92a, miR-21, miR-126, miR-122, miR-26a, and miR-185; all p < 0.04) during FU were identified. Overall apheresis treatment time influenced circulating miR-146a levels (p < 0.04). In LDLR mutation homozygotes (N = 5), compared to heterozygotes (N = 7), we found higher plasma levels of miR-181, miR-126, miR-155, and miR-92a (all p < 0.03). Treatment with PCSK9 inhibitors (N = 6) affected the plasma levels of 7 miRNAs (miR-126, miR-122, miR-26a, miR-155, miR-125a, miR-92a, and miR-27a; all p < 0.04). Long-term monitoring has shown that LA in patients with severe familial hypercholesterolemia influences plasma circulating miRNAs involved in endothelial dysfunction, cholesterol homeostasis, inflammation, and plaque development. The longer the treatment using LA, the better the miRNA milieu depicting the potential cardiovascular risk.

Epigenetic regulation of circ-HIPK3, circ-PVT1, miR-25, and miR-149 in radiosensitivity of breast cancer

Assessing the radiosensitivity of cells before administering radiation therapy (RT) to individuals diagnosed with breast cancer (BC) can facilitate the selection of appropriate treatment regimens and minimize the incidence of adverse side effects in patients undergoing radiation exposure.In this research, blood samples were obtained from 60 women who had been diagnosed with Invasive Ductal Carcinoma (IDC) Breast Cancer. The average age of the patients was 47 ± 9.93. Additionally, the study incorporated 20 healthy women, with an average age of 44.43 ± 6.7. A standard G2 assay was conducted to predict the cellular response to radiation. Out of the 60 samples, the G2 assay identified 20 patients with breast cancer who exhibited radiosensitivity. Hence, molecular investigations were ultimately conducted on two equivalent cohorts comprising 20 subjects each, one with and the other without cellular radiosensitivity. The expression levels of miR-149, miR-25, circ-PVT1, and circ-HIPK3 in peripheral blood mononuclear cells (PBMCs) were evaluated using quantitative polymerase chain reaction (qPCR). Receiver Operating Characteristic (ROC) curves were used to evaluate the sensitivity and specificity of the RNAs. An analysis using binary logistic regression was performed to investigate the relationship between RNAs and both BC and cellular radiosensitivity (CR) in patients with BC.The findings revealed a significant upregulation of Circ-HIPK3 and circ-PVT1 in individuals diagnosed with BC. The levels of Circ-HIPK3 and Circ-PVT1 were found to be directly associated with CR in BC patients. The analysis of the ROC curve demonstrated that circ-HIPK3 and circ-PVT1 exhibit favorable specificity and sensitivity in accurately predicting both BC and CR in patients with BC. The findings from the binary logistic regression analysis demonstrated that circ-HIPK3 and circ-PVT1 were effective predictors of both BC and CR. The ROC curve and binary logistic regression analyses provide evidence that miR-25 is a reliable predictor for BC patients exclusively.Our research has demonstrated that circ-HIPK3, circ-PVT1, and miR-25 may be involved in BC regulatory processes. The circular RNAs Circ-HIPK3 and circ-PVT1, as well as miR-25, among other significant biomarkers, could potentially serve as promising biomarkers for predicting BC. Furthermore, Circ-HIPK3 and circ-PVT1 have the potential to serve as biomarkers for predicting CR in BC patients.

Circulating Plasma miR-122 and miR-583 Levels Are Involved in Chronic Hepatitis B Virus Pathogenesis and Serve As Novel Diagnostic Biomarkers.

Background: MicroRNAs regulate many biological processes and are involved in the pathogenesis of many diseases including chronic hepatitis B (CHB). Moreover, besides investigation of their roles in hepatitis B virus (HBV) infection, a noninvasive, sensitive, and specific biomarker is essential in the diagnosis of liver diseases. This study was designed to evaluate the role of miR-122, miR-583, and miR-24 in the pathogenesis of CHB both in active chronic hepatitis (ACH) patients and in inactive carriers (IC). Materials and Methods: Plasma samples and all relevant clinical features were collected from 43 patients with CHB (28 ACH and 15 IC) and 43 healthy controls. Quantitative real-time PCR was performed to detect the plasma levels of miR-122, miR-583, and miR-24. Results: Results show miR-122 (p = 0.0001) and miR-583 (p = 0.006) but not miR-24 (p = 0.65) were upregulated in patients with CHB versus the control group. Interestingly, there was a significant increase in the plasma expression of miR-583 in IC versus ACH. Moreover, receiver operating characteristic curve analysis determined plasma levels of miR-122 (area under the ROC curve [AUC] = 0.89, p < 0.0001, sensitivity: 100%, specificity: 62.5%) and miR-583 (AUC = 0.71, p = 0.0007, sensitivity: 90%, specificity: 47.62%) as sensitive biomarkers to discriminate CHB patients from controls. Conclusion: Our data showed an increase in the plasma levels of miR-583 in IC versus ACH patients. Moreover, we demonstrated that miR-122 and miR-583 may serve as potential biomarkers for CHB diagnosis and activity.

Targeting miR-223 enhances myeloid-derived suppressor cell suppressive activities in multiple sclerosis patients.

Multiple sclerosis (MS) is an incurable autoimmune inflammatory demyelinating disease of the central nervous system. Several MS medications can modify disease course through effects on adaptive immune cells, while drugs targeting innate immunity are under investigation. Myeloid-derived suppressor cells (MDSCs) which arise during chronic inflammation, are defined by their T-cell immunosuppressive functions. MiR-223 modulates myeloid cell maturation and expansion, including MDSCs. MDSCs isolated from healthy controls (HC) and people with MS (pwMS) were co-cultured with CD4+ T-cells to study their immunosuppressive activities in vitro. Cytokines and chemokines concentration were evaluated by Luminex assay in the serum of HC, pwMS, and other neuroinflammatory diseases and correlated with MDSC activities. MDSC suppressive functions are dysregulated in pwMS compared to HC, which was reversed by glucocorticoids (GC). GC specifically downregulated miR-223 levels in MDSCs and increased the expression of STAT3. In vitro assay showed that miR-223 inhibition enhanced MDSC suppressive activity, STAT3 dependently. By multiple linear regression analysis, we demonstrated that MDSC phosphorylated STAT3 was correlated with serum GM-CSF in HC and pwMS. These results suggest that miR-223 could be a therapeutic target for enhancing MDSC's suppressive activities as an alternative to GC.

Peripheral Blood and Nasopharyngeal Swab MiRNA-155 Expression in Infants with Respiratory Syncytial Virus Infection.

MicroRNA (miR) 155 has been implicated in the regulation of innate and adaptive immunity as well as antiviral responses, but its role during respiratory syncytial virus (RSV) infections is not known. The objective of this study was to investigate the expression of miR-155 using pharyngeal swabs and peripheral blood in infants with RSV infection and uninfected controls. A prospective age-matched study was conducted in primary care in Torino from 1 August 2018 to 31 January 2020. We enrolled 66 subjects, 29 of them patients with RSV infection and 37 age-matched uninfected controls, and collected pharyngeal swabs and peripheral blood in order to assess miR-155 expression with real-time stem-loop-TaqMan real-time PCR. The data show that there is no correlation between pharyngeal swabs and peripheral blood with respect to miR-155 expression. The 1/ΔCq miR-155 expression levels in throat swabs in RSV bronchiolitis patients and healthy controls were 0.19 ± 0.11 and 0.21 ± 0.09, respectively, and were not significantly different between healthy controls and bronchiolitis (p = 0.8414). In the peripheral blood, miR-155 levels were higher than those of healthy control subjects: 0.1 ± 0.013 and 0.09 ± 0.0007, respectively; p = 0.0002. Our data provide evidence that miR-155 expression is higher in peripheral blood during RSV infection but not in swabs. This difference in the timing of sample recruitment could explain the differences obtained in the results; miR-155 activation is probably only assessable in the very early stages of infection in the swab and remains visible for longer in the blood. New investigations are needed in order to clarify whether the miR-155 expression in swabs can be influenced by different stages of virus disease of infants.

Cripto Is Targeted by miR-1a-3p in a Mouse Model of Heart Development.

During cardiac differentiation, numerous factors contribute to the development of the heart. Understanding the molecular mechanisms underlying cardiac development will help combat cardiovascular disorders, among the leading causes of morbidity and mortality worldwide. Among the main mechanisms, we indeed find Cripto. Cripto is found in both the syncytiotrophoblast of ampullary pregnancies and the inner cell mass along the primitive streak as the second epithelial-mesenchymal transformation event occurs to form the mesoderm and the developing myocardium. At the same time, it is now known that cardiac signaling pathways are intimately intertwined with the expression of myomiRNAs, including miR-1. This miR-1 is one of the muscle-specific miRs; aberrant expression of miR-1 plays an essential role in cardiac diseases. Given this scenario, our study aimed to evaluate the inverse correlation between Cripto and miR-1 during heart development. We used in vitro models of the heart, represented by embryoid bodies (EBs) and embryonic carcinoma cell lines derived from an embryo-derived teratocarcinoma in mice (P19 cells), respectively. First, through a luciferase assay, we demonstrated that Cripto is a target of miR-1. Following this result, we observed that as the days of differentiation increased, the Cripto gene expression decreased, while the level of miR-1 increased; furthermore, after silencing miR-1 in P19 cells, there was an increase in Cripto expression. Moreover, inducing damage with a cobra cardiotoxin (CTX) in post-differentiation cells, we noted a decreased miR-1 expression and increased Cripto. Finally, in mouse cardiac biopsies, we observed by monitoring gene expression the distribution of Cripto and miR-1 in the right and left ventricles. These results allowed us to detect an inverse correlation between miR-1 and Cripto that could represent a new pharmacological target for identifying new therapies.

Exosome-shuttled miR-126 mediates ethanol-induced disruption of neural crest cell-placode cell interaction by targeting SDF1.

During embryonic development, 2 populations of multipotent stem cells, cranial neural crest cells (NCCs) and epibranchial placode cells (PCs), are anatomically adjacent to each other. The coordinated migration of NCCs and PCs plays a major role in the morphogenesis of craniofacial skeletons and cranial nerves. It is known that ethanol-induced dysfunction of NCCs and PCs is a key contributor to the defects of craniofacial skeletons and cranial nerves implicated in fetal alcohol spectrum disorder (FASD). However, how ethanol disrupts the coordinated interaction between NCCs and PCs was not elucidated. To fill in this gap, we established a well-designed cell coculture system to investigate the reciprocal interaction between human NCCs (hNCCs) and human PCs (hPCs), and also monitored the migration behavior of NCCs and PCs in zebrafish embryos. We found that ethanol exposure resulted in a disruption of coordinated hNCCs-hPCs interaction, as well as in zebrafish embryos. Treating hNCCs-hPCs with exosomes derived from ethanol-exposed hNCCs (ExoEtOH) mimicked ethanol-induced impairment of hNCCs-hPCs interaction. We also observed that SDF1, a chemoattractant, was downregulated in ethanol-treated hPCs and zebrafish embryos. Meanwhile, miR-126 level in ExoEtOH was significantly higher than that in control exosomes (ExoCon). We further validated that ExoEtOH-encapsulated miR-126 from hNCCs can be transferred to hPCs to suppress SDF1 expression in hPCs. Knockdown of SDF1 replicated ethanol-induced abnormalities either in vitro or in zebrafish embryos. On the contrary, overexpression of SDF1 or inhibiting miR-126 strongly rescued ethanol-induced impairment of hNCCs-hPCs interaction and developmental defects.

Two RNA-binding proteins mediate the sorting of miR223 from mitochondria into exosomes.

Fusion of multivesicular bodies (MVBs) with the plasma membrane results in the secretion of intraluminal vesicles (ILVs), or exosomes. The sorting of one exosomal cargo RNA, miR223, is facilitated by the RNA-binding protein, YBX1 (Shurtleff et al., 2016). We found that miR223 specifically binds a 'cold shock' domain (CSD) of YBX1 through a 5' proximal sequence motif UCAGU that may represent a binding site or structural feature required for sorting. Prior to sorting into exosomes, most of the cytoplasmic miR223 resides in mitochondria. An RNA-binding protein localized to the mitochondrial matrix, YBAP1, appears to serve as a negative regulator of miR223 enrichment into exosomes. miR223 levels decreased in the mitochondria and increased in exosomes after loss of YBAP1. We observed YBX1 shuttle between mitochondria and endosomes in live cells. YBX1 also partitions into P body granules in the cytoplasm (Liu et al., 2021). We propose a model in which miR223 and likely other miRNAs are stored in mitochondria and are then mobilized by YBX1 to cytoplasmic phase condensate granules for capture into invaginations in the endosome that give rise to exosomes.