miR-34a Mimic Research Articles

Glioblastoma Multiforme: A Review

In recent years, many research groups have begun to utilize bioengineered in vitro models of cancer to study mechanisms of disease progression, test drug candidates, and develop platforms to advance personalized drug treatment options. Due to advances in cell and tissue engineering over the last few decades, there are now a myriad of tools that can be used to create such in vitro systems. In this review, we describe the considerations one must take when developing model systems that accurately mimic the in vivo tumor microenvironment (TME) and can be used to answer specific scientific questions. We will summarize the importance of cell sourcing in models with one or multiple cell types and outline the importance of choosing biomaterials that accurately mimic the native extracellular matrix (ECM) of the tumor or tissue that is being modeled. We then provide examples of how these two components can be used in concert in a variety of model form factors and conclude by discussing how biofabrication techniques such as bioprinting and organ-on-a-chip fabrication can be used to create highly reproducible complex in vitro models. Since this topic has a broad range of applications, we use the final section of the review to dive deeper into one type of cancer, glioblastoma, to illustrate how these components come together to further our knowledge of cancer biology and move us closer to developing novel drugs and systems that improve patient outcomes. Glioblastomas are universally fatal cancers and contain self-renewing glioblastoma stem cells (GSCs) that initiate tumors. Traditional anticancer drug development based on in vitro cultures tends to select targets with low therapeutic indices and fails to effectively represent the tumour microenvironment's impacts. Glioblastoma multiforme (GBM) is the most common and aggressive form of brain cancer, with treatment options often constrained due to inherent resistance of malignant cells to conventional therapy. We investigated the impact of triggering programmed cell death (PCD) by using BH3 mimetic drugs in human GBM cell lines. Glioblastoma multiforme (GBM) has been characterized by the high incidence, therapy tolerance and relapse. The molecular events controlling GBM resistant to chemotherapy temozolomide (TMZ) remain to be elusive. Here, we identified WNT signaling was amplified by TMZ and mediated drug response in GBM. We found O6-methylguanine DNA methyltransferase (MGMT) was redundant to WNT-mediated chemoresistance, which was highly associated with p53 mutation status. In GBM with p53 mutation, loss of function of p53 downregulated miR-34a expression, which represses transcription of WNT ligand 6 (WNT6) by directly binding to 3′ UTR of WNT6 mRNA, leading to activation of WNT signaling, and the eventual WNT-mediated chemoresistance to TMZ. Combined treatment of TMZ with WNT inhibitor or miR34a mimic induced drug sensitivity of p53-mutant GBM cells and extended survival in xenograft mice in vivo. Our findings provide insight into understanding the molecular mechanism of GBM chemoresistance to TMZ and facilitating to develop novel treatment strategy to combat p53-mutant GBM by targeting miR-34a/WNT6 axis. Advantages and drawbacks of dexamethasone in glioblastoma multiforme: Dexamethasone has been used for many years to treat brain edema and inflammation caused by GBM.Several investigations have shown that dexamethasone also exerts antitumoral effects against GBM.Unfortunately, steroids are associated with various undesirable side effects. Herein, we review pre-clinical and clinical applications of Dexamethasone in GBM. The most widespread, malignant, and deadliest type of glial tumor is glioblastoma multiforme (GBM). Despite radiation, chemotherapy, and radical surgery, the median survival of afflicted individuals is about 12 months. Unfortunately, existing therapeutic interventions are abysmal. Dexamethasone (Dex), a synthetic glucocorticoid, has been used for many years to treat brain edema and inflammation caused by GBM. Several investigations have recently shown that Dex also exerts antitumoral effects against GBM. On the other hand, more recent disputed findings have questioned the long-held dogma of Dex treatment for GBM. Unfortunately, steroids are associated with various undesirable side effects, including severe immunosuppression and metabolic changes like hyperglycemia, which may impair the survival of GBM patients. Current ideas and concerns about Dex's effects on GBM cerebral edema, cell proliferation, migration, and its clinical outcomes were investigated in this study. Glioblastoma multiforme (GBM) is one of the most common, most formidable, and deadliest malignant types of primary astrocytoma with a poor prognosis. At present, the standard of care includes surgical tumor resection, followed by radiation therapy concomitant with chemotherapy and temozolomide. New developments and significant advances in the treatment of GBM have been achieved ..........

Exosomes from microRNA 146a overexpressed bone marrow mesenchymal stem cells protect against spinal cord injury in rats

BackgroundThis study aimed to investigate the effect of microRNA 146a (miR-146a) overexpressed bone marrow mesenchymal stem cells (BMMSCs) exosomes on spinal cord injury (SCI) recovery. MethodsRat BMMSCs were isolated and transfected with miR-146a mimic (miR-mimic) and control mimic (NC-mimic), after which their exosomes were isolated. Afterward, SCI rat models were constructed, then treated with phosphate buffer saline (PBS), NC BMMSCs exosomes (separated from the culture medium of BMMSCs with NC-mimic), and miR-146a overexpressed BMMSCs exosomes (isolated from the culture medium of BMMSCs with miR-mimic), respectively; additionally, rats underwent sham surgery were treated with PBS as controls. ResultsMiR-146a was upregulated in BMMSCs, and BMMSCs derived exosomes post miR-mimic transfection. Then in SCI rats, BMMSCs exosomes elevated the Basso, Beattie, and Bresnahan (BBB) score and reduced hematoxylin&eosin-reflected spinal cord tissue injury. In addition, BMMSCs exosomes did not affect TUNEL positive cells rate while increased NeuN(+) cells/field in spinal cord tissue from SCI rats. As for inflammation, BMMSCs exosomes repressed pro-inflammatory cytokine expressions, including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, in spinal cord tissue from SCI rats. Furthermore, miR-146a overexpressed BMMSCs exosomes presented with notably better effects regarding elevating BBB score in SCI rats and reducing tissue injury, neuron apoptosis, and inflammation while enhancing neuron viability in spinal cord tissue from SCI rats. ConclusionsMiR-146a overexpressed BMMSCs exosomes enhance locomotor capacity and neuron viability while reducing neuron apoptosis and spinal cord tissue inflammation in SCI rats.

Celastrol attenuates 6-hydroxydopamine-induced neurotoxicity by regulating the miR-146a/PI3K/Akt/mTOR signaling pathways in differentiated rat pheochromocytoma cells

BackgroundParkinson's disease (PD) is a neurological disorder. Recently, celastrol (Cel) has been reported to have neuroprotective properties. We investigated the protective effects of Cel on PD in a cell model with 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in PC12 cells and further addressed the underlying protective mechanisms of Cel. MethodsPC12 cells were treated with 6-OHDA, and Cel was added to the medium at various concentrations. The CCK-8 assay, Hoechst/PI staining, and flow cytometry analysis were performed to detect cellular viability and apoptosis. Mitochondrial membrane potential (MMP) was examined by JC-1 staining. ROS level was quantified by ROS staining. The effects of Cel on the expression of miR-146a and PI3K/Akt/mTOR pathway were then clarified using real-time PCR and Western blotting. Moreover, a miR-146a mimic was synthesized and transfected into PC12 cells to further determine the mechanisms of Cel's neuronal protection against 6-OHDA-induced neurotoxicity. ResultsCel greatly improved cell viability and lessened apoptosis. Flow cytometry showed that Cel especially inhibited early apoptosis. Cel also obviously restored the MMP and decreased ROS level destroyed by 6-OHDA. Moreover, 6-OHDA increased the expression of miR-146a and decreased pAkt/mTOR protein levels, whereas Cel reversed these changes. In particular, miR-146a targeted and inhibited the expression of PI3K, an upstream molecule of Akt/mTOR. Transfection of 6-OHDA-treated neurons with miR-146a mimic notably attenuated Cel's protective effects. LimitationsThere were no animal experiments in our study. ConclusionsCel exerts neuroprotective activity against 6-OHDA-caused neurotoxicity by regulating miR-146a/PI3K/Akt/mTOR pathway, which provides a potential application of Cel for treating neurodegenerative diseases.

The protective effect of MiR-27a on the neonatal hypoxic-ischemic encephalopathy by targeting FOXO1 in rats.

BackgroundNeonatal hypoxic-ischemic encephalopathy (HIE), a kind of hypoxic-ischemic brain damage caused by perinatal asphyxia, is the most crucial cause of neonatal death and long-term neurological dysfunction in children. We aimed to investigate the protective effects of micro (mi)R-27a on HIE in neonatal rats.MethodsA rat model of neonatal HIE was constructed by modification of the Rice-Vannucci model. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to test the expressions of miR-27a, FOXO1 messenger RNA (mRNA), interleukin-1β (IL-1β) mRNA, and tumor necrosis factor-α (TNF-α) mRNA, and western blot was applied to test the expression of FOXO1. In order to overexpress miR-27a, an intracerebroventricular injection (i.c.v) of miR-27a mimic was administered. We adopted 2,3,5-triphenytetrazolium chloride (TTC) staining and brain water content measurement to test the effects of miR-27a on the infarcted volume and edema in brain after HIE. Flow cytometry (FCM) analysis was applied to test the effects of miR-27a on the infiltrated peripheral immune cells in the rat brains after HIE.ResultsWe successfully established a rat model of neonatal HIE. It was revealed that the expressions of miR-27a decreased gradually after HIE, however, the expressions of FOXO1 mRNA increased. After injection of the miR-27a mimic, the expression of miR-27a in the rat HIE model brains was significantly upregulated, however, the expression of FOXO1 was robustly downregulated. Both TTC staining and brain water content showed that the infarcted volume and brain edema was markedly increased after HIE. Interestingly, the overexpression of miR-27a reduced the infarcted volume and edema induced by HIE. Additionally, RT-qPCR and FCM analysis showed that HIE lead to increases of IL-1β, TNF-α, and infiltrated immune cells. Overexpression of miR-27a could reduce the expressions of IL-1β mRNA and TNF-α mRNA, and the cell numbers of infiltrated peripheral macrophages and neutrophils in the brain.ConclusionsMiR-27a plays protective roles by reducing infarct volume and brain edema, and inhibiting inflammatory factors and infiltrated peripheral immune cells by targeting FOXO1 in neonatal HIE rats.

MALAT1 regulates hypertrophy of cardiomyocytes by modulating the miR-181a/HMGB2 pathway.

Noncoding RNAs are important for the regulation of cardiac hypertrophy. The function of MALAT1 (a long noncoding mRNA), miR-181a, and HMGB2, their contribution to cardiac hypertrophy, and the regulatory relationship between them during this process remain unknown. In the present study, we treated primary cardiomyocytes with angiotensin II (Ang II) to mimic cardiac hypertrophy. MALAT1 expression was significantly downregulated in Ang II-treated cardiomyocytes compared with control cardiomyocytes. Ang II-induced cardiac hypertrophy was suppressed by overexpression of MALAT1 and promoted by genetic knockdown of MALAT1. A dual-luciferase reporter assay demonstrated that MALAT1 acted as a sponge for miR-181a and inhibited its expression during cardiac hypertrophy. Cardiac hypertrophy was suppressed by overexpression of an miR-181a inhibitor and enhanced by overexpression of an miR-181a mimic. HMGB2 was downregulated during cardiac hypertrophy and was identified as a target of miR-181a by bioinformatics analysis and a dual-luciferase reporter assay. miR-181a overexpression decreased the mRNA and protein levels of HMGB2. Rescue experiments indicated that MALAT1 overexpression reversed the effect of miR-181a on HMGB2 expression. In summary, the results of the present study show that MALAT1 acts as a sponge for miR-181a and thereby regulates expression of HMGB2 and development of cardiac hypertrophy. The novel MALAT1/miR-181a/HMGB2 axis might play a crucial role in cardiac hypertrophy and serve as a new therapeutic target.

Tendon-Specific Dicer Deficient Mice Exhibit Hypoplastic Tendon Through the Downregulation of Tendon-Related Genes and MicroRNAs.

Tendon is a fibrous connective tissue, that is, transmitting the forces that permit body movement. However, tendon/ligament biology is still not fully understood and especially, the role of miRNAs in tendon/ligament is sparse and uncharacterized in in vivo models. The objectives of this study were to address the function of DICER using mice with tendon/ligament-specific deletion of Dicer (Dicer conditional knockout; cKO), and to identify key miRNAs in tendon/ligament. Dicer cKO mice exhibited hypoplastic tendons through structurally abnormal collagen fibrils with downregulation of tendon-related genes. The fragility of tendon did not significantly affect the tensile strength of tendon in Dicer cKO mice, but they showed larger dorsiflexion angle in gait compared with Control mice. We identified two miRNAs, miR-135a and miR-1247, which were highly expressed in the Achilles tendon of Control mice and were downregulated in the Achilles tendon of Dicer cKO mice compared with Control mice. miR-135a mimic increased the expression of tendon-related genes in injured Achilles tendon-derived fibroblasts. In this study, Dicer cKO mice exhibited immature tendons in which collagen fibrils have small diameter with the downregulation of tendon-related genes such as transcriptional factor, extracellular matrix, and miRNAs. Thus, DICER plays an important role in tendon maturation, and miR-135a may have the potential to become key miRNA for tendon maturation and healing.

Regulatory role of miR-146a in corneal epithelial wound healing via its inflammatory targets in human diabetic cornea

PurposeMiR-146a upregulated in limbus vs. central cornea and in diabetic vs. non-diabetic limbus has emerged as an important immune and inflammatory signaling mediator in corneal epithelial wound healing. Our aim was to investigate the potential inflammation-related miR-146a target genes and their roles in normal and impaired diabetic corneal epithelial wound healing. MethodsOur previous data from RNA-seq combined with quantitative proteomics of limbal epithelial cells (LECs) transfected with miR-146a mimic vs. mimic control were analyzed. Western blot and immunostaining were used to confirm the expression of miR-146a inflammatory target proteins in LECs and organ-cultured corneas. Luminex assay was performed on conditioned media at 6- and 20-h post-wounding in miR-146a mimic/inhibitor transfected normal and diabetic cultured LECs. ResultsOverexpression of miR-146a decreased the expression of pro-inflammatory TRAF6 and IRAK1 and downstream target NF-κB after challenge with lipopolysaccharide (LPS) or wounding. Additionally, miR-146a overexpression suppressed the production of downstream inflammatory mediators including secreted cytokines IL-1α, IL-1β, IL-6 and IL-8, and chemokines CXCL1, CXCL2 and CXCL5. These cytokines and chemokines were upregulated in normal but not in diabetic LEC during wounding. Furthermore, we achieved normalized levels of altered secreted cytokines and chemokines in diabetic wounded LEC via specific inhibition of miR-146a. ConclusionOur study documented significant impact of miR-146a on the expression of inflammatory mediators at the mRNA and protein levels during acute inflammatory responses and wound healing, providing insights into the regulatory role of miR-146a in corneal epithelial homeostasis in normal and diabetic conditions.

Effect of miR-34a on the Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells (BMSCs) in Hyperlipidemia Rats

This study intends to explore miR-34a’s effect on BMSCs osteogenic differentiation of hyperlipidemia. 20 SD rats were equally assigned into control group (normal diet) and high-fat group (research diet). Cells were transfected with miR-34a mimic or negative control followed by meausring miR-34a, Dvl2, PPAR-γ, ALP, Runx2, and sp7, and ALP activity. The number of mineralized nodules, adipocytes, miR-34a and PPAR-γ expression in high-fat group were significantly increased and Dvl2, ALP, Runx2, and sp7 mRNA showed opposite profiles. Meanwhile, Runx2, ALP protein, cytoplasm and nuclear blue-black particles, Dvl2 protein and mRNA in miR-34a mimic group were significantly downregulated (P < 0.05). Additionally, the luciferase activity of wild-type plasmid+miR-34a mimic group was significantly lower than mutant group, indicating that miR-34a targets Dvl2. In conclusion, miR-34a inhibits the osteogenic differentiation of hyperlipidemia BMSCs by inhibiting the expression of Dvl2, Runx2 and ALP activity, indicating that it might be target in the hyperlipidemia treatment.

Expression of Concern: MicroRNA-26a reduces synovial inflammation and cartilage injury in osteoarthritis of knee joints through impairing the NF-κB signaling pathway.

The Editorial Office has been made aware of potential issues surrounding the scientific validity of this paper, including duplications between the BMS-345541 panel of Figure 6D and the miR-26a mimics panel of figure 3D, one of which appears to be vertically flipped and the colour altered, as well as duplications found between cells on the Figure 4C miR-26a mimic panel and the Figure 7C BMS-345541 panel, which has also been vertically flipped. The authors have been contacted with regards to these concerns but have currently not responded to the Journal's queries.

MiR-146a suppresses the expression of vascular endothelial growth factor and inflammatory responses in diabetic retinopathy

This study was designed to explore the role of miR-146a in diabetic retinopathy (DR). 30 healthy control (HC), 50 patients with type 2 diabetes mellitus, and 48 DR patients were enrolled. Blood was collected and levels of miR-146a expression, vascular endothelial growth factor (VEGF), and three inflammatory cytokines (NF-κB, IL-1β, and TNF-α) were detected. Moreover, ARPE-19 cells were treated with miR-146a mimic or inhibitor in the presence of high glucose to evaluate its effect in vitro. DR patients had the lowest level of miR-146a and the highest level of VEGF as well as the most severe inflammation among the three groups. In addition, the miR-146a level was negatively correlated with the expression of VEGF and three inflammatory cytokines, respectively in DR patients. Moreover, VEGF expression was positively correlated with these three inflammatory cytokines in DR patients. In summary, miR-146a could inhibit VEGF expression and inflammation in DR.

MicroRNAs modulate Chlamydia trachomatis infection- and vaccine-induced immunity in macrophages

Abstract Recent studies indicate that microRNAs (miRNAs), including immune cell type-specific miRNAs modulate inflammation and immune response to Chlamydia trachomatis (CT) genital infection. However, the role of these miRNAs in modulation of immune cell function following CT infection or vaccine stimulation has not been investigated. We hypothesized that pretreatment of CT-infected and vaccine-stimulated macrophages with miRNA mimics or inhibitors will modulate secretion of inflammatory cytokines and expression of IFN-γ pathway-related genes. Thus, THP-1-differentiated macrophages (TDM) transfected with miRNA mimics or inhibitors were infected with CT or stimulated with a Vibrio cholerae ghost (rVCG)-based vaccine (rVCG-MECA) and the level of inflammatory cytokines secreted in culture supernatants was assessed by cytokine ELISA. Also, TDM expression of IFN-γ pathway-related genes was assessed by RT-qPCR. The results show that CT infection of TDM resulted in the downregulation of miR-15a, miR-29a, miR-146a and miR-222 while stimulation with rVCG-MECA resulted in their upregulation, as we previously reported. The level of TNF-α, IL-8, IL-1β and IFN-γ secreted by miRNA mimic- or inhibitor-treated TDM following infection or vaccine stimulation was dependent on the miRNA type. Furthermore, CT infection of untreated macrophages increased mRNA expression of INFGR1, JAK2, STAT1 and SOCS1. However, pretreatment of CT-infected cells with miR-146a mimic or inhibitor showed significantly decreased expression of these genes. The study demonstrated that miRNAs differentially modulate macrophage secretion of inflammatory cytokines and expression of IFN-γ pathway-related genes following CT infection or vaccine stimulation. Supported by None.

Neurotoxic Astrocytes Directly Converted from Sporadic and Familial ALS Patient Fibroblasts Reveal Signature Diversities and miR-146a Theragnostic Potential in Specific Subtypes.

A lack of stratification methods in patients with amyotrophic lateral sclerosis (ALS) is likely implicated in therapeutic failures. Regional diversities and pathophysiological abnormalities in astrocytes from mice with SOD1 mutations (mSOD1-ALS) can now be explored in human patients using somatic cell reprogramming. Here, fibroblasts from four sporadic (sALS) and three mSOD1-ALS patients were transdifferentiated into induced astrocytes (iAstrocytes). ALS iAstrocytes were neurotoxic toward HB9-GFP mouse motor neurons (MNs) and exhibited subtype stratification through GFAP, CX43, Ki-67, miR-155 and miR-146a expression levels. Up- (two cases) and down-regulated (three cases) miR-146a values in iAstrocytes were recapitulated in their secretome, either free or as cargo in small extracellular vesicles (sEVs). We previously showed that the neuroprotective phenotype of depleted miR-146 mSOD1 cortical astrocytes was reverted by its mimic. Thus, we tested such modulation in the most miR-146a-depleted patient-iAstrocytes (one sALS and one mSOD1-ALS). The miR-146a mimic in ALS iAstrocytes counteracted their reactive/inflammatory profile and restored miR-146a levels in sEVs. A reduction in lysosomal activity and enhanced synaptic/axonal transport-related genes in NSC-34 MNs occurred after co-culture with miR-146a-modulated iAstrocytes. In summary, the regulation of miR-146a in depleted ALS astrocytes may be key in reestablishing their normal function and in restoring MN lysosomal/synaptic dynamic plasticity in disease sub-groups.

MicroRNA-20a elevates osteogenic/odontoblastic differentiation potential of dental pulp stem cells by nuclear factor-κB/p65 signaling pathway via targeting interleukin-8

ObjectiveIn this study, we aimed to explore the mechanism underlying microRNA-20a (miR-20a) in viability, migration and osteogenic/odontoblastic differentiation of dental pulp stem cells (DPSCs). DesignThe results of Targetscan unveiled that interleukin (IL)− 8 might bind to miR-20a, which was confirmed by dual-luciferase reporter assay. MiR-20a expression was up-regulated or down-regulated in DPSCs, followed by measurement of cell viability and migration via MTT and wound healing assays. Then, IL-8 was over-expressed in miR-20a mimic-transfected DPSCs with or without nuclear factor (NF)-κB inhibitor. The effect of miR-20a on osteogenic/odontoblastic differentiation potential of DPSCs was determined by alkaline phosphatase and alizarin red S staining. The expression levels of IL-8, osteogenic differentiation indicators and NF-κB/p65 signaling pathway in cells were detected through quantitative real-time polymerase chain reaction (qRT-PCR) or western blot ResultsContrary to the down-regulated miR-20a, up-regulated miR-20a not only reinforced the viability and migration of DPSCs, but also promoted cell osteogenic/odontoblastic differentiation potential and related gene expressions (alkaline phosphatase, osteocalcin, and dentin sialophosphoprotein (DSPP)). Furthermore, IL-8 was verified to be the target of miR-20a. IL-8 over-expression effectively suppressed the osteogenic/odontoblastic differentiation potential as well as inhibited the activation of NF-κB pathway in DPSCs induced by miR-20a mimic, but these effects could be counteracted by NF-κB inhibitor. ConclusionMiR-20a up-regulation accelerated the viability, migration and osteogenic/odontoblastic differentiation potential of DPSCs by regulating NF-κB/p65 signaling pathway via targeting IL-8, which might be a potential treatment target for dental diseases.

MicroRNA-30a contributes to pre-eclampsia through regulating the proliferation, apoptosis, and angiogenesis modulation potential of mesenchymal stem cells by targeting AVEN

ABSTRACT Pre-eclampsia (PE) is a pregnancy-associated disease related to an unprecedented hypertension attack. Mesenchymal stem cells (MSCs) play a crucial role in PE pathology. . Our research was designed to illustrate the functions of microRNA-30a (miR-30a) in proliferation, apoptosis, and the potential of regulating angiogenesis in MSCs, and to analyze its potential molecular mechanisms. TargetScan software and the luciferase reporter assay were used to forecast and verify the relationship between miR-30a and AVEN. MiR-30a and AVEN expression in the decidual tissue and decidua (d)MSCs of healthy pregnant women and PE patients were assessed using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Cell proliferation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide (MTT), flow cytometry, and transwell assays were used to evaluate cell proliferation, growth, the cell cycle, apoptosis, and migration. Furthermore, the tube formation ability was evaluated using the human umbilical vein endothelial cell (HUVEC) tube formation assay. AVEN is the target gene of miR-30a. MiR-30a was upregulated in decidual tissues and dMSCs of PE patients. However, AVEN was weakly expressed, and AVEN expression was negatively related to miR-30a levels in decidual tissues and dMSCs of PE patients. Compared to the mimic control group, upregulation of miR-30a inhibited dMSC proliferation and cell growth, promoted G0/G1 phase arrest, and induced apoptosis. Furthermore, the miR-30a mimic transfected dMSC culture supernatant suppressed HTR-8/SVneo cell migration ability and HUVEC tube formation ability. However, AVEN reversed these changes. In conclusion, miR-30a/AVEN may serve as a new axis for PE treatment.

MiRNA-29a inhibits atherosclerotic plaque formation by mediating macrophage autophagy via PI3K/AKT/mTOR pathway.

Background: miR-29a plays a vital role in AS, but the relationship between the miR-29a-targeted PI3K signaling pathway and AS remains unclear. Therefore, this study was carried out.Methods: Gene expression profiles from the GEO database containing AS samples were analyzed. ApoE−/− mice and RAW264.7 cells were treated with miR-29a negative control (NC), miR-29a mimic and miR-29a inhibitor to establish the AS model. Then MOVAT staining, TEM, Western blotting, and immunofluorescence staining were adopted for testing target proteins.Results: DEGs were identified from GSE137578, GSE132651, GSE113969, GSE43292, and GSE97210 datasets. It was found that there were targeted binding sites between miR-29a and PIK3CA. Besides, GO and KEGG analysis demonstrated that autophagy was an enriched pathway in AS. Later, PPI network was depicted, and hub genes were then determined. The results revealed that miR-29a suppressed the areas of plaques and lesional macrophages, but had no impact on VSMCs. TEM results showed the organelles pyknosis of lesional macrophages damaged morphological changes. Furthermore, miR-29a amplified the M2-like macrophages but suppressed the polarization of M1-like macrophages in atherosclerotic plaques. According to mouse and RAW 264.7 cell experiments, miR-29a significantly inhibited the protein expressions of PI3K, p-PI3K, p-AKT, and p-mTOR, which were consistent with the increased expressions of autophagy-related proteins, Beclin 1 and LC3II. However, the miR-29a suppression exhibited the contrary results.Conclusion: MiR-29a elevation induces the increase of autophagy by down-regulating the PI3K/AKT/mTOR pathway in the progression of AS, indicating that miR-29a is a novel therapeutic strategy for AS.

Toxoplasma gondii promotes microRNA-34a to inhibit Foxp3 expression in adverse outcomes of pregnancy in mice

Infection with Toxoplasma gondii (T. gondii) during the pregnant period causes microcephaly, mental and psychomotor retardation or death. Miserable outcomes are mainly linked with regulatory T cells (Tregs) dysfunction. Forkhead box P3 (Foxp3), a vital regulator of establishment and maintenance of Tregs, can be modulated by microRNAs (miRNAs). Previously, our study revealed that T. gondii infection in pregnant mice induced Tregs dysfunction, accompanied with reduced Foxp3 expression. The role of miRNAs in the inhibition of Foxp3 triggered by T. gondii remains unclear. Herein, T. gondii infection promotes miR-34a expression in the placenta of mice. miR-34a mimic inhibits Foxp3 expression via targeting 3′ untranslated region (3′UTR) whereas its inhibitor promotes Foxp3 expression in vitro. T. gondii antigens could enhance the activity of miR-34a promoter via a Smad4-dependent mechanism. Collectively, our data reveal a new avenue through which T. gondii inhibits Foxp3 expression necessary to drive adverse outcomes of pregnancy in mice.

Niclosamide induces miR-148a to inhibit PXR and sensitize colon cancer stem cells to chemotherapy.

SummaryTumor recurrence is often attributed to cancer stem cells (CSCs). We previously demonstrated that down-regulation of Pregnane X Receptor (PXR) decreases the chemoresistance of CSCs and prevents colorectal cancer recurrence. Currently, no PXR inhibitor is usable in clinic. Here, we identify miR-148a as a targetable element upstream of PXR signaling in CSCs, which when over-expressed decreases PXR expression and impairs tumor relapse after chemotherapy in mouse tumor xenografts. We then develop a fluorescent reporter screen for miR-148a activators and identify the anti-helminthic drug niclosamide as an inducer of miR-148a expression. Consequently, niclosamide decreased PXR expression and CSC numbers in colorectal cancer patient-derived cell lines and synergized with chemotherapeutic agents to prevent CSC chemoresistance and tumor recurrence in vivo. Our study suggests that endogenous miRNA inducers is a viable strategy to down-regulate PXR and illuminates niclosamide as a neoadjuvant repurposing strategy to prevent tumor relapse in colon cancer.

MiR-146a alleviates lung injury caused by RSV infection in young rats by targeting TRAF-6 and regulating JNK/ERKMAPK signaling pathways

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection in infants and children. The present study aimed to investigate the effects of miR-146a on RSV replication and the related mechanisms. Material and methods: We pretreated A549 and HEp-2 cells and young rats with miR-146a mimic before infection with RSV. The expressions of miR-146a and RSV-F mRNA in cells and lung tissues were detected by RT-qPCR, and production of IL-1β, IL-6, IL-18, and TNF-α in bronchial alveolar lavage fluid (BALF) were determined by ELISA. The expression level of TRAF-6 and activation of the JNK/ERK/MAPK/NF-κB signaling pathway was detected by Western blotting. Results: RSV infection significantly reduced miR-146a levels in both A549 and HEp-2 cells and rat lung tissues. RSV infection resulted in accelerated growth, increased release of inflammatory cytokines, increased expression of TRAF-6, and activation of the JNK pathway in cells, and the lung inflammatory infiltration and the pathological score increased in rats. Overexpression of miR-146a targeted down-regulation of TRAF-6 expression and JNK/ERK/MAPK/NF-κB pathway induced by RSV infection, reduced the production of inflammatory cytokines IL-1β, IL-6 and TNF-α, and alleviate lung injury in young rats. We got similar results in both A549 and HEp-2 cell experiments. Conclusion: MiR-146a alleviates lung injury caused by RSV infection in young rats by targeting TRAF-6 and regulating JNK/ERK/MAPK signaling pathways.

Prelimbic cortex miR-34a contributes to (2R,6R)-hydroxynorketamine-mediated antidepressant-relevant actions

The ketamine metabolite (2R,6R)-hydroxynorketamine (HNK) has recently been suggested to exert fast-acting antidepressant-relevant actions and was proposed as an ideal next-generation antidepressant. However, the microRNA-mediated mechanism underlying its effects is still unknown. In the present study, we investigated the role of miR-34a in the prelimbic (PL) cortex during (2R,6R)-HNK-mediated antidepressant-like effects. Male (8–10 weeks old) C57BL/6J mice and primary hippocampal cultured neurons were employed. The tests of forced swimming, tail suspension, sucrose preference, and female urine sniffing were used as indices of depressive-like behaviors. (2R,6R)-HNK enhanced miR-34a levels in a time-dependent manner at 1, 24 h, and 3 days in vitro, in a time-dependent manner at 1 and 24 h, and in a dose-dependent manner at 10 and 30 mg/kg in PL. Pretreatment with NBQX or verapamil blocked (2R,6R)-HNK-enhanced miR-34a expression and NBQX pretreatment blocked AMPA-elevated miR-34a levels in vitro. AAV-miR-34a in PL produced antidepression-behavioral effects and rescued stress-induced depressive-like behaviors. Moreover, PL AAV-miR-34a increased the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) and potentiated evoked excitatory postsynaptic currents (EPSCs). Slices incubated with miR-34a mimic acutely enhanced the frequency and amplitude of mEPSCs in the PL. Intra-PL application of miR-34a rapidly produced antidepression-like effects and reversed stress-evoked depressive-like behaviors. Furthermore, intra-PL application of anti-miR-34a attenuated both systemic and local (2R,6R)-HNK-mediated antidepressant-like actions. Collectively, these results suggest that miR-34a in PL plays an antidepression-like role and contributes to the fast-acting antidepressant-relevant actions of (2R,6R)-HNK. The present study provides evidence for a miR-34a-dependent mechanism underlying the fast-acting antidepressant-like actions of (2R,6R)-HNK, indicating a novel role of PL miR-34a in antidepression.

Upregulation of microRNA-34a enhances myocardial ischemia-reperfusion injury via the mitochondrial apoptotic pathway

Mitochondrial oxidative injury can result in many cardiovascular diseases including cardiac ischemia-reperfusion (I/R) injury. This study was designed to investigate whether microRNA-34a (miR-34a) influences cardiac I/R or hypoxia/reoxygenation (H/R) injury by regulating the mitochondrial apoptotic pathway from oxidative injury.In vivo, myocardial infarction size was examined by Evan blue/TTC staining. Apoptosis was assessed by TUNEL assay. Heart function was measured by echocardiography. Lactate dehydrogenase (LDH) and creatine kinase (CK) were evaluated. In vitro, H9c2 cardiomyocytes were exposed to H/R stimulation. Cell viability was assessed by the CCK-8 assay and apoptosis was detected by Annexin V/PI staining. Mitochondrial superoxide, mitochondrial membrane potential (MMP) and ATP production was evaluated by detection kits, and related proteins were detected by western blotting analysis. We observed that the level of miR-34a was significantly upregulated in I/R rats compared to the sham group. Injection of adenovirus inhibiting miR-34a into the left ventricular anterior wall improved heart function and decreased I/R injury. H9c2 cardiomyocytes exposed to H/R stimulation displayed an obvious increase in miR-34a expression. In addition, miR-34a inhibitor alleviated, whereas miR-34a mimic aggravated H/R-induced mitochondrial injury. Bcl-2 was identified as a target gene of miR-34a by dual-luciferase reporter gene detection. Knockdown of Bcl-2 abolished the cardioprotection of the miR-34a inhibitor in H9c2 cells. In summary,our study demonstrates that inhibition of miR-34a exhibits therapeutic potential in treatment of myocardial I/R injury by restraining mitochondrial apoptosis.