L-carnitine contributes to enhancement of viability and quality of platelet concentrates through changing the apoptotic and anti-apoptotic associated microRNAs

BACKGROUND

Micro RNAs are known as the main regulator of messenger RNA translation in platelets and have a vital role in process of apoptosis during platelet storage. Our pervious study revealed that the expression of miR-145 and miR-326 changed significantly in platelets under maintenance conditions. This study aimed to evaluate the effect of L-carnitine (LC) as an additive to augment platelet quality by changing the microRNA expression.

METHODS

We used ten platelet concentrate (PC) bags and divided each into two equal parts, LC- treated, and LC free PC. The expression of miR-145 and miR-326 were determined using real-time PCR. Moreover, we measured platelet count, platelet aggregation, platelet viability, and lactate dehydrogenase activity in all samples.

RESULTS

The miR-326 expression significantly increased during platelet storage with mean fold changes of 3.2 for the control and 2.5 for LC- treated PC. The mean fold changes in miR-145 expression was less in the control PC (0.52) compared to the LC- treated PC (0.79). Increased levels of platelet count, platelet aggregation, and platelet viability were found in the LC-treated compared to the untreated PC.

CONCLUSION

LC has a protective effect on platelet apoptosis, reduces the expression of apoptotic microRNA, and prevents the reduction of anti-apoptotic microRNA.

Long-term, in vivo therapeutic effects of a single dose of miR-145 micelles for atherosclerosis

Atherosclerosis is a chronic inflammatory disease that is characterized by the build-up of lipid-rich plaques in the arterial walls. The standard treatment for patients with atherosclerosis is statin therapy aimed to lower serum lipid levels. Despite its widespread use, many patients taking statins continue to experience acute events. Thus, to develop improved and alternative therapies, we previously reported on microRNA-145 (miR-145 micelles) and its ability to inhibit atherosclerosis by targeting vascular smooth muscle cells (VSMCs). Importantly, one dose of miR-145 micelles significantly abrogated disease progression when evaluated two weeks post-administration. Thus, in this study, to evaluate how long the sustained effects of miR-145 micelles can be maintained and towards identifying a dosing regimen that is practical for patients with chronic disease, the therapeutic effects of a single dose of miR-145 micelles were evaluated for up to two months in vivo. After one and two months post-treatment, miR-145 micelles were found to reduce plaque size and overall lesion area compared to all other controls including statins without causing adverse effects. Furthermore, a single dose of miR-145 micelle treatment inhibited VSMC transdifferentiation into pathogenic macrophage-like and osteogenic cells in plaques. Together, our data shows the long-term efficacy and sustained effects of miR-145 micelles that is amenable using a dosing frequency relevant to chronic disease patients.

An Increase in Plasma MicroRNA-143 Levels in the Acute Phase Is Positively Correlated With Recovery of Cardiac Function in the Chronic Phase in Patients With Acute Myocardial Infarction

BACKGROUND

MicroRNA (miR)-143 and miR-145 are non-coding RNAs present in smooth muscle cells and the heart. However, their behavior and physiological role in patients with acute myocardial infarction (AMI) have not been clarified.Methods and Results: Plasma miR-143 and miR-145 concentrations were measured on Day 0 (on admission) and on Day 7 in AMI patients who could be followed up for 6 months (n=25). The control group consisted of subjects without significant coronary stenosis (n=20). Blood samples were collected from the antecubital vein, and plasma miR-143 and miR-145 concentrations were measured by quantitative reverse transcription-polymerase chain reaction. In AMI patients (n=25), left ventricular ejection fraction (LVEF) was measured by echocardiography in the acute and chronic (6 months) phases. On Day 7, plasma miR-143 and miR-145 concentrations were significantly higher in AMI patients than in the control group and on Day 0 in AMI patients. Plasma miR-143 and miR-145 concentrations increased significantly from Day 0 to Day 7. The increase in plasma miR-143 concentrations (∆miR-143) in the acute phase was positively correlated with the increase in LVEF in the chronic phase. Among many factors, only ∆miR-143 was favorably correlated with left ventricle (LV) functional recovery in the chronic phase.

CONCLUSIONS

An increase in plasma miR-143 concentrations in the acute phase may be a biomarker predicting recovery of LV function in the chronic phase in AMI patients.

Functional analysis of the miR-145/Fascin1 cascade in canine oral squamous cell carcinoma

OBJECTIVES

Canine oral squamous cell carcinoma (SCC) often develops in the gingiva and tonsils. The biological behaviour of canine oral SCC is similar to that of human head and neck SCC (HNSCC). Inhibiting invasion and metastasis is major importance for the treatment of canine and human HNSCC. In this study, the significance of microRNA (miR)-145 and Fascin1 (FSCN1) in the invasion of canine oral SCC was explored.

MATERIALS AND METHODS

Canine oral SCC tissues and cell lines were used for miR-145 and FSCN1 expression analysis via real-time PCR and immunohistochemistry. Canine oral SCC cell lines were used for in vitro assays.

RESULTS

miR-145 was downregulated while FSCN1 mRNA was upregulated in canine oral SCC. Immunohistochemistry revealed that FSCN1 was upregulated in SCC when compared to normal mucosa. Transfection of canine SCC cells with miR-145 or FSCN1 siRNA suppressed cell growth and attenuated cell migration as well as invasion by inhibiting the epithelial-to-mesenchymal transition. Furthermore, the promoter region of miR-145 was highly methylated in SCC cell lines and tissues.

CONCLUSION

The expression profile and functions of miR-145 in canine oral SCC are similar to those in human HNSCC. Thus, canine oral SCC may represent a valuable preclinical model for human HNSCC.

Knockdown of Long Non-coding RNA TUG1 Suppresses Migration and Tube Formation in High Glucose-Stimulated Human Retinal Microvascular Endothelial Cells by Sponging miRNA-145

Diabetic retinopathy (DR) is a serious complication of diabetes mellitus. The purpose of this study was to investigate the potential functional role of long non-coding RNA TUG1 in high glucose (HG)-stimulated human retinal microvascular endothelial cells (hRMECs). The results demonstrated that following 72 h of HG stimulation, enhanced proliferation, migration, and tube formation process were observed in hRMECs. Moreover, HG treatment markedly increased TUG1 expression in hRMECs, and knockdown of TUG1 notably restrained the aberrant phenotypes of hRMECs induced by HG. Mechanistically, TUG1 may serve as a competing endogenous RNA (ceRNA) for miR-145, thereby blocking the repression on VEGF-A in hRMECs. Rescue experiments further indicated that inhibition of miR-145 abolished the beneficial role of TUG1 knockdown in HG-treated hRMECs. Our data suggested that knockdown of TUG1 protects hRMECs against HG stimulation partly by regulating miR-145/VEGF-A axis.

Repression of circRNA_000684 inhibits malignant phenotypes of pancreatic ductal adenocarcinoma cells via miR-145-mediated KLF5

BACKGROUND

Circular RNAs (circRNAs) are aberrantly expressed in pancreatic ductal adenocarcinoma (PDAC). In the current study, we investigated how circRNA_000684 affected the progression of PDAC, and how it regulated kruppel-like factor 5 (KLF5) and microRNA (miR)-145.

METHODS

Differentially expressed circRNAs, miRs and genes related to PDAC as well as their targeting relationship were predicted using bioinformatics analyses. Binding relationships among circRNA_000684, miR-145 and KLF5 were verified using dual-luciferase reporter gene assay, RIP and RNA pull-down assay, respectively. The effects of circRNA_000684, miR-145, KLF5 on the malignant phenotypes of PDAC cells and human umbilical vein endothelial cell (HUVEC) angiogenesis were assessed using loss- and gain-of function experiments by CCK-8 assay, scratch test, Transwell and tube formation assays. RT-qPCR and Western blot analysis were used to determine MCM2, MMP2 and MMP9 and VEGFA expression. In addition, the roles of circRNA_000684, miR-145, and KLF5 in tumor growth were validated through in vivo experiments.

RESULTS

Expression of CircRNA_000684 and KLF5 was upregulated, whereas miR-145 expression was downregulated in PDAC tissues and cells. CircRNA_000684 repression or miR-145 elevation inhibited the proliferation, invasion and migration of PDAC cells and HUVEC angiogenesis, as evidenced by lower levels of MCM2, MMP2 and MMP9 and VEGFA. CircRNA_000684 negatively regulated miR-145 expression, while miR-145 negatively regulated KLF5. In-vivo, circRNA_000684 elevation or miR-145 repression promoted tumor growth.

CONCLUSION

Taken together, the present study provided evidence clarifying that circRNA_000684 could downregulate miR-145 expression and elevate KLF5 to promote the progression of PDAC.

MicroRNA-145 plays a role in mitochondrial dysfunction in alveolar epithelial cells in lipopolysaccharide-induced acute respiratory distress syndrome

BACKGROUND

Acute respiratory distress syndrome (ARDS) causes substantial mortalities. Alveolar epithelium is one of the main sites of cell injuries in ARDS. As an important kind of microRNAs (miRNAs), microRNA-145 (miR-145) has been studied in various diseases, while its role in ARDS has not been investigated.

METHODS

Lipopolysaccharide (LPS) was intratracheally instilled to establish a rat ARDS model. Cytokines from bronchoalveolar lavage fluid (BALF) were measured using rat tumor necrosis factor-α and interleukin-6 enzyme-linked immunosorbent assay kits (R&D Systems), and the pathological structures were evaluated using hematoxylin and eosin (H&E) staining and transmission electron microscope; the lung miR-145 messenger RNA (mRNA) was detected using quantitative polymerase chain reaction. Bioinformatics focused on the target genes and possible pathways of gene regulation.

RESULTS

A rat model of LPS-induced ARDS was successfully established. The miR-145 was down-regulated in the LPS-induced ARDS lung, and mitochondrial dysfunction was observed in alveolar epithelial cells, most obviously at 72 hours after LPS. TargetScan and miRDB databases were used to predict the target genes of miR-145. A total of 428 overlapping genes were identified, seven genes were associated with mitochondrial function, and Ogt, Camk2d, Slc8a3, and Slc25a25 were verified. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were enriched in the mitogen-activated protein kinase (MAPK) signaling pathway, and Gene Ontology (GO) biological process was mainly enriched in signal transduction and transcription regulation.

CONCLUSIONS

The miR-145 is down-regulated in LPS-induced ARDS, and affects its downstream genes targeting mitochondrial functions.

Silencing of long non-coding RNA Sox2ot inhibits oxidative stress and inflammation of vascular smooth muscle cells in abdominal aortic aneurysm via microRNA-145-mediated Egr1 inhibition

Long non-coding RNAs (lncRNAs) have been largely reported to contribute to the development and progression of abdominal aortic aneurysm (AAA), a common vascular degenerative disease. The present study was set out with the aim to investigate the possible role of lncRNA Sox2ot in the development of AAA. In this study, we found that lncRNA Sox2ot and early growth response factor-1 (Egr1) were highly expressed, while microRNA (miR)-145 was poorly expressed in Ang II-induced AAA mice and oxidative stress-provoked vascular smooth muscle cell (VSMC) model. Egr1 was a potential target gene of miR-145, and lncRNA Sox2ot could competitively bind to miR-145 to upregulate Egr1 expression. Overexpression of miR-145-5p was found to attenuate oxidative stress and inflammation by inhibiting Egr1 both in vivo and in vitro, which was counteracted by lncRNA Sox2ot. Taken together, the present study provides evidence that downregulation of lncRNA Sox2ot suppressed the expression of Egr1 through regulating miR-145, thus inhibiting the development of AAA, highlighting a theoretical basis for AAA treatment.

MicroRNA-145 is involved in endothelial cell dysfunction and acts as a promising biomarker of acute coronary syndrome

Background

Acute coronary syndrome (ACS) is a serious type of cardiovascular diseases. This study aimed to investigate the expression patterns and clinical value of microRNA-145 (miR-145) in ACS patients, and further uncover the function of miR-145 in ACS rats.

Methods

Quantitative real-time PCR was used to estimate the expression of miR-145. Diagnostic value of miR-145 was evaluated, and its correlation with endothelial injury marker (vWF and H-FABP) and pro-inflammatory cytokines (IL-6 and TNF-α) was analyzed. Coronary artery ligation was adopted to construct the ACS rat model, and the effects of miR-145 on endothelial injury, inflammation and vascular endothelial cells (VECs) biological function were examined.

Results

Downregulated expression of miR-145 was found in the ACS serum samples compared with the healthy controls. The expression of miR-145 was proved to be a diagnostic biomarker and negatively correlated with vWF, H-FABP, IL-6 and TNF-α. The similar serum expression trends of miR-145 in ACS patients were also observed in the ACS rats, and the overexpression of miR-145 could decrease the elevated vWF, H-FABP, IL-6 and TNF-α in the animal model. Moreover, the upregulation of miR-145 in VECs led to promoted proliferation and migration. The bioinformatics prediction data and luciferase report results indicated that FOXO1 was a direct target of miR-145.

Conclusions

In conclusion, it was hypothesized that serum decreased expression of miR-145 may serve as a potential diagnostic biomarker in ACS patients. Overexpression of miR-145 may improve the endothelial injury and abnormal inflammation through targeting FOXO1, indicating that miR-145 serves as a candidate therapeutic target of ACS.

MicroRNA-145 Inhibits Cell Migration and Invasion in Colorectal Cancer by Targeting TWIST

Introduction

MicroRNAs function as oncogenes or tumor suppressors in the development of various human cancers. We investigated the effect of microRNA-145 (miR-145) on colorectal cancer (CRC) cell invasion and migration.

Methods

The levels of miR-145 in CRC cells were examined by quantitative PCR; Western blotting was used to detect TWIST1 (twist family bHLH transcription factor 1) protein and the epithelial–mesenchymal transition (EMT)-related proteins (E-cadherin, vimentin). Then, we transfected miR-145 mimics or inhibitor into CRC cells and used the wound healing and Transwell invasion assays to investigate their migration and invasive capability, respectively.

Results

The miR-145 mimics suppressed CRC cell invasion and migration significantly; in contrast, miR-145 downregulation had the opposite effect. Furthermore, miR-145 regulated TWIST1 levels negatively at transcriptional level. TWIST1 knockdown significantly inhibited the CRC cell migration ability and the number of CRC cells that crossed the Transwell membrane. There was no significant difference in terms of migration and invasive capability after the cells had been transfected with miR-145 mimics or inhibitor plus TWIST1 small interfering RNA (siRNA) as compared to the TWIST1 siRNA–only group. Furthermore, we demonstrate that the inhibition of miR-145 could enhance the capability for lung metastasis in vivo.

Conclusion

Taken together, these findings indicate that miR-145 acts as a new tumor suppressor by regulating TWIST1 and plays a vital role in the invasive and migration ability of CRC cells.

MicroRNA-145 Involves in the Pathogenesis of Renal Vascular Lesions and May Become a Potential Therapeutic Target in Patients with Juvenile Lupus Nephritis

AIMS

The current study was conducted with the central objective of investigating the expression of microRNA-145 (miR-145) in renal vascular lesions (RVLs) in juvenile lupus nephritis (JLN) and its possible mechanism.

METHODS

The clinical data of 49 JLN patients confirmed by renal biopsy were collected and followed by grouping according to the RVLs score after hematoxylin-eosin staining: mild, moderate, and severe groups. In situ hybridization was used to detect the expression of miR-145 in renal vessels which was then being compared among different RVLs groups. Up-LV-miR-145 and LV-miR-NC lentiviral vectors were constructed and transfected into human vascular smooth muscle cells (HVSMCs), respectively. After HVSMCs were treated with 10.0 µg/L platelet-derived growth factor (PDGF)-BB for 24 h, the proliferation, migration, and apoptosis of endothelial cells were detected by MTT, Transwell assay, and flow cytometry, respectively. Western blot was used to detect expression of alpha-smooth muscle actin (α-SM-actin) and osteopontin (OPN).

RESULTS

The expression of miR-145 in renal vascular cells was statistically significant. The higher the inner membrane ratio, the lesser the miR-145 expression. After treatment with PDGF-BB, expression of miR-145 in HVSMCs decreased, proliferation and migration ability enhanced, apoptosis decreased, α-SM-actin decreased, and OPN increased. The proliferation and migration ability of HVSMCs in the LV-miR-145 group suppressed, apoptosis enhanced, α-SM-actin increased, and OPN decreased.

CONCLUSIONS

Our study revealed that miR-145 expression decreased with the increase of vascular damage. miR-145 can inhibit proliferation, migration, and differentiation phenotypic transformation of HVSMCs induced by PDGF-BB. miR-145 may be involved in the pathogenesis of RVLs and may be a new target for treatment of RVLs in lupus nephritis.

Elevated microRNA-145 inhibits the development of oral squamous cell carcinoma through inactivating ERK/MAPK signaling pathway by down-regulating HOXA1

Background: Oral cancer is one of the most frequent solid cancers worldwide, and oral squamous cell carcinoma (OSCC) constitutes approximately 90% of oral cancers. The discovery of reliable prognostic indicators would be a potential strategy for OSCC treatment. In the present study, we aim to explore the underlying mechanism by which microRNA-145 (miR-145) affected OSCC. Methods: Forty-eight patients diagnosed with OSCC were enrolled to obtain the OSCC tissues and adjacent normal tissues. The targeting relationship between miR-145 and Homeobox A1 (HOXA1) was verified. In order to assess the effects of miR-145 in OSCC and the detailed regulatory mechanism, the SCC-9 cell line was adopted, in which expression of miR-145 and HOXA1 were altered by transfection. Then, a series of in vitro and in vivo experiments were performed to evaluate the cell viability, migration, invasion, and tumor growth. Results: miR-145 was poorly expressed and HOXA1 was highly expressed in OSCC. HOXA1 was verified as a target of miR-145 to mediate the activation of the extracellular signal-regulated kinase/mitogen activated protein kinase (ERK/MAPK) signaling pathway. In the circumstance of miR-145 elevation or HOXA1 depletion, the SCC-9 cell line manifested with inhibited cell viability, invasion, and migration in vitro, coupled with reduced tumor growth in vivo, with a decreased expression of ERK/MAPK signaling pathway-related genes/proteins. Conclusion: These findings suggested that miR-145 can inhibit HOXA1 to inactivate the ERK/MAPK signaling pathway, thereby suppressing OSCC cell proliferation, migration, and invasion to further inhibit the development of OSCC, highlighting a novel therapeutic target for the OSCC treatment.

Baicalin protects human retinal pigment epithelial cell lines against high glucose-induced cell injury by up-regulation of microRNA-145

BACKGROUND

Diabetic retinopathy (DR) is a common complication of diabetes mellitus, which is a major reason of blindness. Baicalin (BAI) is a flavonoid extracted from Scutellaria baicalensis, whose pharmacological characterizes have been widely reported in various diseases. However, it remains unclear the effect of BAI on DR. The study aimed to confirm the protective effect of BAI on DR.

METHODS

ARPE-19 cells and HRMECs were exposed to the high glucose (HG) environment to construct a cell injury model. After treatment with HG and BAI, cell viability, apoptosis, inflammatory cytokines and ROS generations were determined in ARPE-19 cells and HRMECs. Subsequently, microRNA-145 (miR-145) inhibitor and its negative control were transfected into ARPE-19 cells, and the regulatory effects on HG-and BAI-co-treated cells were detected. NF-κB and p38MAPK signaling pathways were finally examined to state the underling mechanisms.

RESULTS

HG treatment significantly induced ARPE-19 cells and HRMECs injury in vitro. BAI significantly promoted cell proliferation, reduced apoptosis, as well as inhibited the release of IL-1β, IL-6, IL-8 and ROS level in HG-injured ARPE-19 cells and HRMECs. Additionally, the expression level of miR-145 was up-regulated in HG-and BAI-co-treated cells. More importantly, miR-145 inhibition reversed the protective effect of BAI on HG-injured ARPE-19 cells. Besides, we observed that BAI inhibited the activations of NF-κB and p38MAPK pathways by up-regulating miR-145.

CONCLUSIONS

Results demonstrated that BAI exhibited the protective effect against HG-induced cell injury by up-regulation of miR-145.

MicroRNA-145 attenuates IL-6-induced enhancements of sensitivity to UVB irradiation by suppressing MyD88 in HaCaT cells

MicroRNAs (miRNAs/miRs) play vital roles in various immune diseases including systemic lupus erythematosus (SLE). The current study aimed to assess the role of miR-145 in interleukin-6 (IL-6)-treated HaCaT cells under ultraviolet B (UVB) irradiation and further explore the potential regulatory mechanism. HaCaT cells were pretreated with IL-6 and then exposed to UVB to assess the effect of IL-6 on sensitivity of HaCaT cells to UVB irradiation. The levels of miR-145 and MyD88 were altered by transfection and the transfected efficiency was verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR)/western blot analysis. Cell viability, percentage of apoptotic cells and expression levels of apoptosis-related factors were measured by trypan blue assay, flow cytometry assay, and western blot analysis, respectively. In addition, the levels of c-Jun N-terminal kinases (JNK) and nuclear factor-κB (NF-κB) signaling pathway-related factors were assessed by western blot analysis. IL-6 treatments significantly aggravated the reduction of cell viability and promotion of cell apoptosis caused by UVB irradiation in HaCaT cells. Interestingly, miR-145 level was augmented by UVB exposure and miR-145 mimic alleviated IL-6-induced increase of sensitivity to UVB irradiation in HaCaT cells, as dramatically increased cell viability and reduced cell apoptosis. Opposite effects were observed in miR-145 inhibitor-transfected cells. Meanwhile, MyD88 was negatively regulated by miR-145 and MyD88 mediated the regulatory effect of miR-145 on IL-6- and UVB-treated cells. In addition, miR-145 mimic inhibited the JNK and NF-κB pathways by down-regulating MyD88. In conclusion, the present study demonstrated that miR-145 alleviated IL-6-induced increase of sensitivity to UVB irradiation by down-regulating MyD88 in HaCaT cells.

Effect of microRNA-145 on proliferation and apoptosis of human non-small cell lung cancer A549 cells by regulating mTOR signaling pathway

Our study aims to explore the impact of microRNA-145 (miR-145) on proliferation and apoptosis of non-small cell lung cancer (NSCLC) cells by modulating mTOR signaling pathway. Paired NSCLC and adjacent normal tissues were obtained from 50 NSCLC patients between January 2014 and January 2016. Human lung adenocarcinoma A549 cell line was assigned into the control, mimics, mimics-negative control (NC), inhibitor and inhibitor-NC groups. Quantitative RT-PCR and Western blot were applied to detect the expressions of miR-145 and mTOR. MTT, scratch test, Transwell and flow cytometry were carried out to analyze the effect of miR-145 on A549 cell proliferation, migration, invasion, apoptosis and cycle distribution and regulation of mTOR signaling pathway. MiR-145 expression in NSCLC tissues was lower than that in adjacent normal tissues, while mTOR expression was higher in NSCLC tissues than in adjacent normal tissues. Compared with the control and mimics groups, cell proliferation, migration and invasion abilities decreased in the mimics group; additionally, cell apoptosis rate increased and cells were mostly in G1 phase. MiR-145 inhibited the activation of mTOR signaling pathway. Compared with the control and inhibitor-NC groups, mTOR signaling pathway was activated and cell proliferation, migration and invasion abilities increased in the inhibitor group, and cell apoptosis rate decreased and cells were less in G1 phase. The study indicated that miR-145 expression was low in NSCLC and influenced NSCLC cells by negatively regulating mTOR signaling pathway. This article is protected by copyright. All rights reserved.

Hypoxia promotes the skewed differentiation of umbilical cord mesenchymal stem cells toward type II alveolar epithelial cells by regulating microRNA-145

Mesenchymal stem cells (MSCs) are well recognized for their ability to differentiate into type II alveolar epithelial (ATII) cells in damaged lungs, which is critical for reepithelization and recovery in acute lung injury (ALI). However, the high level of transforming growth factor-β (TGF-β) commonly seen in injured lung tissues is also able to induce MSCs to differentiate into fibroblast-like cells. In this study, we found that hypoxia could promote umbilical cord mesenchymal stem cells (UCMSCs) differentiation into ATII cells rather than into fibroblast-like cells, and this effect was mainly mediated by microRNA-145 (miR-145), which could induce the inhibition of TGF-β signaling by targeting TGF-β receptor II (TGFβRII). Clarifying the function of hypoxia in the fate determination of MSCs is important for improving stem cell-based therapies for ALI.

MicroRNA-145 Mediates the Formation of Angiotensin II-Induced Murine Abdominal Aortic Aneurysm

BACKGROUND

MicroRNA-145 (miR-145) has been implicated in vascular smooth muscle cell differentiation, but the underlying mechanisms have not been fully understood, especially their role in abdominal aortic aneurysm (AAA) expansion. Here, we sought to explore and define the mechanisms of miR-145 function in the experimental AAA models in AngII-infused ApoE-/- mice.

METHODS

miR-145 was overexpressed in ApoE-/- mice via lentivirus infection, and then the incidence of AAA, maximum abdominal aortic diameter, elastin degradation and MMP2 activation were determined in AngII-infused ApoE-/- mice.

RESULTS

In vivo overexpression of miR-145 by lentivirus infection greatly decreased the incidence of AAA, maximum abdominal aortic diameter, and elastin degradation, accompanied with downregulation of MMP2 activation in AngII-infused ApoE-/- mice. Cell culture assays indicated that miR-145 inhibited AngII-induced upregulation of MMP2 gene expression. In contrast, deficiency of MMP2 abolished the effects of miR-145 on AngII-induced elastin and collagens degradations in ApoE-/- mice.

CONCLUSION

These data suggest that regulation of expression of miR-145 may be a potential therapeutic option for vascular disease progression such as AAA expansion.

MicroRNA-145-based differentiation of human mesenchymal stem cells to smooth muscle cells

OBJECTIVES

To investigate the role of microRNA-145, that regulates gene expression of genes related to differentiation, proliferation and the phenotype of smooth muscle cells (SMCs), in the differentiation of human bone marrow mesenchymal stem cells (hBM-MSCs) to SMCs.

RESULTS

Real-time PCR analysis indicated significant upregulation of SMC markers, including SM-α-actin, calponin, caldesmon and SMMHC, in SMCs compared to hBM-MSCs. Conversely, Krüppel-like factor 4, the direct target of microRNA-145 and the suppressor of smooth muscle differentiation, was suppressed in hBM-MSC-derived SMCs. Western blot analysis and immunocytochemistry also confirmed that the introduction of microRNA-145 into hBM-MSCs induced mature contractile SMCs. The functionality of hBM-MSC-derived SMCs was assessed by proliferation assay using PDGF-BB and contractility assay using carbachol. The results showed that the produced SMCs contracted in response to carbachol stimulation.

CONCLUSION

Overexpression of microRNA-145 in undifferentiated hBM-MSCs results in functionally mature contractile SMCs that can be used in drug discovery and cell therapy in SMC disorders such as vascular disease.

MicroRNA-145 inhibits hepatic stellate cell activation and proliferation by targeting ZEB2 through Wnt/β-catenin pathway

The activation of hepatic stellates cells (HSCs) is well believed to play a pivotal role in the development of liver fibrosis. MicroRNA-145 (miR-145) is known to suppress the progression of hepatocellular carcinoma, and is previously reported to be associated with Wnt/β-catenin pathway, but its role in the progression of hepatic fibrosis and activation of HSCs remains unknown and is warranted for investigation. In the present study, we found that the expression of miR-145 is significantly down-regulated in vivo in CCl4-induced mice liver fibrosis as well as in transforming growth factor-β1 (TGF-β1) induced HSC-T6 cell lines and human hepatic stellate cell line LX-2 in vitro. Furthermore, over-expression of miR-145 inhibited TGF-β1-induced the activation and proliferation of HSC-T6 cells in vitro. Mechanistically, we identified that zinc finger E-box-binding homeobox 2 (ZEB2), a key mediator of epithelial-to-mesenchymal transition, acted as a functional downstream target for miR-145. Interestingly, ZEB2 was shown to be involved in the TGF-β1-induced HSCs activation by regulating Wnt/β-catenin signaling pathway. Taken together, our results revealed the critical regulatory role of miR-145 in HSCs activation and implied miR-145 as a potential candidate for therapy of hepatic fibrosis by regulation of Wnt/β-catenin through targeting ZEB2.

miR-145 modulates lncRNA-ROR and Sox2 expression to maintain human amniotic epithelial stem cell pluripotency and β islet-like cell differentiation efficiency

In this study, we observed a great reduction in the expression of the endogenous long noncoding RNA ROR (lncRNA-ROR) and the stem cell transcription factor Sox2, in contrast to a marked increase in miR-145 expression, during the course of in vitro induced differentiation of human amniotic epithelial stem cells (HuAECs). Bioinformatics analysis and the luciferase reporter assay revealed binding of miR-145 to specific sites in lncRNA-ROR and Sox2, silencing their expression. Overexpression of a lncRNA-ROR-specific siRNA effectively downregulated the expression levels of Sox2 and other stem cell markers in HuAECs while weakening the efficiency of HuAEC differentiation into β islet-like cells. Moreover, the in vitro response of HuAEC-derived β islet-like cells to extracellular stimuli and C-peptide release by these cells were markedly weakened in the siRNA-ROR transfection group. Furthermore, the in vivo expression of β islet-like cell biomarkers was substantially reduced in HuAECs in the siRNA-ROR transfection group, and their in vivo β islet-like cell differentiation and insulin release capacities were reduced in a streptozocin-induced diabetic rat model. The experimental results indicate that lncRNA-ROR effectively maintains Sox2 gene expression through competitive binding to miR-145, achieving pluripotency maintenance in HuAECs and regulation of their directed β islet-like cell differentiation efficiency.

MicroRNA-145 and MicroRNA-133a Inhibited Proliferation, Migration, and Invasion, While Promoted Apoptosis in Hepatocellular Carcinoma Cells Via Targeting FSCN1

BACKGROUND

Deregulation of FSCN1 has been observed in human cancers. However, the regulatory mechanism of FSCN1 in hepatocellular carcinoma (HCC) remains largely unknown.

AIMS

Our study aimed to reveal the roles of microRNA (miR)-133a, miR-145, and FSCN1 in HCC cells.

METHODS

Real-time RT-PCR and western blot were performed to determine the expression of miR-133a, miR-145, and FSCN1. Luciferase reporter assay was used to determine whether FSCN1 was a target of miR-133a and miR-145. Effects of miR-133a, miR-145, and FSCN1 on HCC cell proliferation, apoptosis, migration, and invasion were then investigated.

RESULTS

We showed that the expression of FSCN1 was increased in HCC tissues compared to the normal adjacent tissues. Moreover, upregulation of FSCN1 and downregulation of miR-145 and miR-133a co-existed in HCC. Functional studies revealed that miR-145 and miR-133a negatively regulated the expression of FSCN1 in HCC cells, via directly binding to the 3'-untranslational region of FSCN1 mRNA. Overexpression of miR-145 and miR-133a led to decreased FSCN1 expression, and downregulation of miR-145 and miR-133a resulted in increased FSCN1 expression in HCC cells. Furthermore, overexpression of miR-145 and miR-133a inhibited cellular proliferation, migration, and invasion, while promoted apoptosis in HCC cells. On the contrary, inhibition of miR-145 and miR-133a promoted cellular proliferation, migration, and invasion, while suppressed apoptosis in HCC cells.

CONCLUSION

Our study suggests that the abnormal upregulation of FSCN1 in HCC is associated with downregulation of miR-145 and miR-133a, and miR-145 and miR-133a inhibit malignant progression of HCC in vitro, possibly via directly targeting FSCN1.

MiR-145 facilitates proliferation and migration of endothelial progenitor cells and recanalization of arterial thrombosis in cerebral infarction mice via JNK signal pathway

Arterial thrombosis in cerebral infarction severely affects patients' lives. Classical treatment including surgery and medication both had significantly adverse effects, making it necessary to find novel strategy. Endothelial progenitor cells (EPCs) have been shown to enhance the recanalization of thrombosis, while leaving its molecular mechanism unclear. EPCs were separated from peripheral blood, and were transfected by microRNA (miR)-145. The growth, proliferation and migration abilities were quantified by MTT, clone formation and Transwell assays, respectively. Cell apoptosis was evaluated by flow cytometry. The activation of JNK signaling pathway was measured by Western blotting, followed by JNK inhibitor SP600125. In a mouse cerebral infarction model, miR-145 transfected EPCs were injected to observe the condition of arterial thrombosis. MiR-145 transfection enhanced growth, migration and proliferation of EPCs without induction of apoptosis. MiR-145 exerts its effects via JNK signaling pathway, as the blocking inhibited cell migration/proliferation. In vivo injection of miR-145 transfected EPCs also potentiated cell proliferation and migration, in addition to the recanalization of arterial thrombosis. MiR-145 facilitates proliferation and migration of EPCs and recanalization of arterial thrombosis in cerebral infarction mice via JNK signal pathway. This study provided new insights regarding infarction treatment.

Lipid nanoparticle delivery of a microRNA-145 inhibitor improves experimental pulmonary hypertension

Therapies that exploit RNA interference (RNAi) hold great potential for improving disease outcomes. However, there are several challenges that limit the application of RNAi therapeutics. One of the most important challenges is effective delivery of oligonucleotides to target cells and reduced delivery to non-target cells. We have previously developed a functionalized cationic lipopolyamine (Star:Star-mPEG-550) for in vivo delivery of siRNA to pulmonary vascular cells. This optimized lipid formulation enhances the retention of siRNA in mouse lungs and achieves significant knockdown of target gene expression for at least 10days following a single intravenous injection. Although this suggests great potential for developing lung-directed RNAi-based therapies, the application of Star:Star-mPEG mediated delivery of RNAi based therapies for pulmonary vascular diseases such as pulmonary arterial hypertension (PAH) remains unknown. We identified differential expression of several microRNAs known to regulate cell proliferation, cell survival and cell fate that are associated with development of PAH, including increased expression of microRNA-145 (miR-145). Here we test the hypothesis that Star:Star-mPEG mediated delivery of an antisense oligonucleotide against miR-145 (antimiR-145) will improve established PAH in rats. We performed a series of experiments testing the in vivo distribution, toxicity, and efficacy of Star:Star-mPEG mediated delivery of antimiR-145 in rats with Sugen-5416/hypoxia induced PAH. We showed that after subchronic therapy of three intravenous injections over 5weeks at 2mg/kg, antimiR-145 accumulated in rat lung tissue and reduced expression of endogenous miR-145. Using a novel in situ hybridization approach, we demonstrated substantial distribution of antimiR-145 in the lungs as well as the liver, kidney, and spleen. We assessed toxic effects of Star:Star-mPEG/antimiR-145 with serial complete blood counts of leukocytes and serum metabolic panels, gross pathology, and histopathology and did not detect significant off-target effects. AntimiR-145 reduced the degree of pulmonary arteriopathy, reduced the severity of pulmonary hypertension, and reduced the degree of cardiac dysfunction. The results establish effective and low toxicity of lung delivery of a miRNA-145 inhibitor using functionalized cationic lipopolyamine nanoparticles to repair pulmonary arteriopathy and improve cardiac function in rats with severe PAH.

miR-145, targeting high-mobility group A2, is a powerful predictor of patient outcome in ovarian carcinoma

MicroRNA-145 (miR-145) expression is downregulated in several human cancers, but its clinical and functional relevance to ovarian carcinoma has not yet been elucidated. This study addressed the hypothesis that miR-145 serves as a prognostic biomarker and a tumor suppressor that regulates the expression of high-mobility group A2 (HMGA2) oncoprotein in ovarian cancer. Here, we found that low miR-145 expression and HMGA2 overexpression determined by qRT-PCR and immunohistochemistry significantly correlated with advanced stage, lymph node involvement, and distant metastasis in 74 ovarian carcinomas. Low miR-145 expression significantly correlated with tumor recurrence and worse overall survival (HR=8.62, P = 0.039). Transfection of pre-miR-145 resulted in reduced cell growth and migration, and increased apoptosis of ovarian cancer cells by TUNEL, colony forming, and cell migration assays. MiR-145 was found to directly target HMGA2 by luciferase assay and Western blotting. Our findings suggest that miR-145 functions as a tumor suppressor in ovarian cancer and directly targets HMGA2 oncoprotein. Low miR-145 and high HMGA2 expressions are potential biomarkers of poor prognosis of ovarian carcinoma and miR-145 is the more powerful predictor of patient outcome.

MicroRNA-145 suppresses hepatocellular carcinoma by targeting IRS1 and its downstream Akt signaling

Accumulating evidences have proved that dysregulation of microRNAs (miRNAs) is involved in cancer initiation and progression. In this study, we showed that miRNA-145 level was significantly decreased in hepatocellular cancer (HCC) tissues and cell lines, and its low expression was inversely associated with the abundance of insulin receptor substrate 1 (IRS1), a key mediator in oncogenic insulin-like growth factor (IGF) signaling. We verified IRS1 as a direct target of miR-145 using Western blotting and luciferase reporter assay. Further, the restoration of miR-145 in HCC cell lines suppressed cancer cell growth, owing to down-regulated IRS1 expression and its downstream Akt/FOXO1 signaling. Our results demonstrated that miR-145 could inhibit HCC through targeting IRS1 and its downstream signaling, implicating the loss of miR-145 regulation may be a potential molecular mechanism causing aberrant oncogenic signaling in HCC.

Down-regulation of microRNA-145 ablates c-Myc inhibition and promotes hepatoma progression

AIM: To investigate whether microRNA-145 (miR-145) controls hepatoma progression through modulating c-Myc activity.

METHODS: Quantitative real-time PCR was used to detect miR-145 expression in different liver lesions and cell lines. Quantitative real-time PCR and Western blot were adopted to detect the expression of c-Myc mRNA and protein in different liver lesions, respectively. After transfection of HepG2 cells with an miR-145 mimic, quantitative real-time PCR, Western blot and flow cytometry were used to detect the expression of c-Myc mRNA and protein and cell apoptosis, respectively.

RESULTS: MiR-145 mRNA was underexpressed in hepatocellular carcinoma (HCC) and tumor-adjacent tissue compared to normal liver tissue (0.878 ± 0.146 vs 0.265 ± 0.084, 0.271 ± 0.096, both P < 0.05). MiR-145 mRNA was also underexpressed in HepG2 cells compared to L-02 cells (0.755 ± 0.185 vs 0.471 ± 0.074, P < 0.05). C-Myc mRNA and protein were overexpressed in HCC and tumor-adjacent tissue compared to normal liver tissue (mRNA: 0.136 ± 0.071, 0.451 ± 0.026 vs 0.029 ± 0.023; protein: 0.301 ± 0.022, 0.445 ± 0.018 vs 0.137 ± 0.011; all P < 0.05). C-Myc protein expression was down-regulated in HepG2 cells transfected with an miR-145 mimic compared to cells transfected with empty vector and untransfected cells (0.146 ± 0.011 vs 0.366 ± 0.014, 0.350 ± 0.013, both P < 0.05). Transfection of an miR-145 mimic promoted the apoptosis of HepG2 cells compared to cells transfected with empty vector and untransfected cells (3.000 ± 0.100 vs 1.167 ± 0.153, 0.933 ± 0.208, both P < 0.05).

CONCLUSION: MiR-145 down-regulation-mediated ablation of inhibition of c-Myc may be a major cause of hepatocarcinogenesis. MiR-145 can promote cell apoptosis.