Project description:Aims: Mesenchymal stem cells (MSCs) gradually become attractive candidates for cardiac inflammation modulation, yet understanding of the mechanism remains elusive. Strikingly, recent studies indicated that exosomes secreted by MSCs might be a novel mechanism for the beneficial effect of MSCs transplantation after myocardial infarction. We therefore explored the role of MSC-derived exosomes (MSC-Exo) in the immunomodulation of macrophages after myocardial ischemia-reperfusion and its implications in cardiac injury repair. Methods and Results: Exosomes were isolated from the supernatant of MSCs using a gradient centrifugation method. Administration of MSC-Exo through intramyocardial injection after myocardial ischemia reperfusion reduced infarct size and alleviated inflammation level in heart and serum. Systemic depletion of macrophages with clodronate liposomes abolished the curative effects of MSC-Exo. MSC-Exo modified the polarization of M1 macrophages to M2 macrophages both in vivo and in vitro. miRNA-sequencing of MSC-Exo and bioinformatics analysis implicated miR-182 as a potent candidate mediator of macrophage polarization and TLR4 as a downstream target. Diminishing miR-182 in MSC-Exo partially attenuated its modulation of macrophage polarization. Likewise, knock down of TLR4 also conferred cardioprotective efficacy and reduced inflammation level in a mouse model of myocardial ischemia/reperfusion. Conclusion: Our data indicates that MSC-Exo attenuates myocardial ischemia/reperfusion injury via shuttling miR-182 that modifies the polarization state of macrophages. This study sheds new light on the application of MSC-Exo a potential therapeutic tool for myocardial ischemia/reperfusion injury.
Project description:Early reperfusion of ischemic cardiac tissue remains the most effective intervention for improving clinical outcome following myocardial infarction. However, abrupt increases in intracellular Ca2+ during myocardial reperfusion cause cardiomyocyte death and consequent loss of cardiac function, referred to as ischemia/reperfusion (IR) injury. Cardiac IR is accompanied by dynamic changes in expression of microRNAs (miRNAs), which inhibit specific mRNA targets. miR-214 is up-regulated during ischemic injury and heart failure in mice and humans, but its potential role in these processes is unknown. We show that genetic deletion of miR-214 in mice causes loss of cardiac contractility, increased apoptosis, and excessive fibrosis in response to IR injury. The microarray contains 6 samples, each containing cDNA pooled from 3 mice per group. There are no replicates. The array was designed to make 3 different pairwise comparisons between the following: P14 WT and miR-214 KO hearts; adult WT and miR-214 KO skeletal muscle; adult WT and miR-214 KO hearts
Project description:Expression profiling of prostate EPT1 cells transducted with two types of miRNAs (miR-182, miR-203) and RNAi clones knocking down SNAI2.
Project description:We performed RNA-seq experiments, one with the WT control and Mir182ΔM/ΔM osteoclast precursors at baseline and after RANKL stimulation, the other with miR-182 gain of function approach using the control and Mir182mTg BMMs, to identify genes regulated by miR-182 in osteoclast precursors.
Project description:Early reperfusion of ischemic cardiac tissue remains the most effective intervention for improving clinical outcome following myocardial infarction. However, abrupt increases in intracellular Ca2+ during myocardial reperfusion cause cardiomyocyte death and consequent loss of cardiac function, referred to as ischemia/reperfusion (IR) injury. Cardiac IR is accompanied by dynamic changes in expression of microRNAs (miRNAs), which inhibit specific mRNA targets. miR-214 is up-regulated during ischemic injury and heart failure in mice and humans, but its potential role in these processes is unknown. We show that genetic deletion of miR-214 in mice causes loss of cardiac contractility, increased apoptosis, and excessive fibrosis in response to IR injury.
Project description:To identify genes differentially modulated by anti-miR-182 treatment in a liver melanoma metastasis mouse model. Targeting oncogenic microRNAs is emerging as a promising strategy for cancer therapy. Here we provide proof-of-principle for the safety and efficacy of miRNA targeting against metastatic tumors. We tested the effect of targeting miR-182, a pro-metastatic miRNA frequently overexpressed in melanoma, whose silencing represses invasion and induces apoptosis in vitro. In particular, we assessed the effect of anti-miR-182 oligonucleotides synthesized with 2’ sugar modifications and a phosphorothioate backbone in a mouse model of melanoma liver metastasis. Luciferase imaging showed that mice treated with anti-miR-182 had an appreciably lower burden of liver metastases compared to the control. We confirmed that miR-182 levels were effectively downregulated in the anti-miR treated tumors relative to the scrambled treated tumor both in the liver and in the spleen. This downregulation was accompanied by an upregulation of miR-182 direct targets. Transcriptome analysis of mouse tissues treated with anti-miR-182 or scramble oligonucleotides revealed an enrichment for genes controlling survival, adhesion and migration modulated in response to anti-miR-182 treatment. These data indicate that in vivo administration of anti-miRs allows for efficient miRNA targeting and concomitant upregulation of target levels. Our results suggest that the use of anti-miR-182 is a promising therapeutic strategy for metastatic melanoma and provide solid proof-of-principle for similar strategies against other metastatic tumors. Keywords: Differentially expressed genes (mRNAs) in response to miRNA inhibition
Project description:A unique feature of the liver is its high regenerative capacity, which is essential to maintain liver homeostasis. However, key regulators of liver regeneration (LR) remain ill-defined. Here, we identify hepatic miR-182-5p as a key regulator of LR. Suppressing miR-182-5p, whose expression is significantly induced in the liver of mice post two-thirds partial hepatectomy (PH), abrogates PH-induced LR in mice. In contrast, liver-specific overexpression of miR-182-5p promotes LR in mice with PH. Overexpression of miR-182-5p failed to promote proliferation in hepatocytes, but stimulates proliferation when hepatocytes are cocultured with stellate cells. Mechanistically, miR-182-5p stimulates Cyp7a1-mediated cholic acid production in hepatocytes, which promotes hedgehog (Hh) ligand production in stellate cells, leading to the activation of Hh signaling in hepatocytes and consequent cell proliferation. Collectively, our study identified miR-182-5p as a critical regulator of LR and uncovers a Cyp7a1/cholic acid-dependent mechanism by which hepatocytes crosstalk to stellate cells to facilitate LR.
Project description:To identify genes differentially modulated by anti-miR-182 treatment in a liver melanoma metastasis mouse model. Targeting oncogenic microRNAs is emerging as a promising strategy for cancer therapy. Here we provide proof-of-principle for the safety and efficacy of miRNA targeting against metastatic tumors. We tested the effect of targeting miR-182, a pro-metastatic miRNA frequently overexpressed in melanoma, whose silencing represses invasion and induces apoptosis in vitro. In particular, we assessed the effect of anti-miR-182 oligonucleotides synthesized with 2â sugar modifications and a phosphorothioate backbone in a mouse model of melanoma liver metastasis. Luciferase imaging showed that mice treated with anti-miR-182 had an appreciably lower burden of liver metastases compared to the control. We confirmed that miR-182 levels were effectively downregulated in the anti-miR treated tumors relative to the scrambled treated tumor both in the liver and in the spleen. This downregulation was accompanied by an upregulation of miR-182 direct targets. Transcriptome analysis of mouse tissues treated with anti-miR-182 or scramble oligonucleotides revealed an enrichment for genes controlling survival, adhesion and migration modulated in response to anti-miR-182 treatment. These data indicate that in vivo administration of anti-miRs allows for efficient miRNA targeting and concomitant upregulation of target levels. Our results suggest that the use of anti-miR-182 is a promising therapeutic strategy for metastatic melanoma and provide solid proof-of-principle for similar strategies against other metastatic tumors. Keywords: Differentially expressed genes (mRNAs) in response to miRNA inhibition Quadruplicate (n=4) samples of anti-miR-182 treated human melanoma metastasis compared to quadruplicate control treated metastasis.
Project description:This experiment is designed to evaluate gene expression alteration following miR-182 transfection in glioma cells. We find a significant elevation of NF kappa B transcriptional targets. Total RNA were extracted from SNB-19 glioma cells transfected with miR-182 mimic oligo or miRNA mimic negative control 36 hours after transfection, two biological replications for each treatment.
Project description:miR-182 over-expression enhances macrophage resistance to intracellular pathogens. This transcriptional profiling experiment was conducted to identify the basis for protection. Primary human alveolar macrophage-like monocyte derived macrophages were transfected with miR-182 mimic or control RNA, then infected overnight with F. tularensis Live Vaccine Strain at MOI-10 or mock infected.