Dexamethasone and MicroRNA-204 Inhibit Corneal Neovascularization

INTRODUCTION

This was an in vivo animal study designed to investigate the interaction between dexamethasone (Dex) and microRNA-204 (miR-204) in a mouse alkali burn-induced corneal neovascularization (CNV) model. The function of miR-204 was then investigated in human mammary epithelial cells (HMECs) in vitro.

MATERIALS AND METHODS

The CNV model was induced by corneal alkali burn in BLAB/c mice. The mice were randomly divided into five groups: normal control (Ctrl), alkali burn-induced corneal injury (Alkali), alkali burn + Dex (Dex), alkali burn + negative control (NTC), and alkali burn + miR-204 agomir (miR-204). Subconjunctival injection of NTC, Dex, or miR-204 agomir was conducted at 0, 3, and 6 days, respectively, after alkali burn. The corneas were collected at day 7 after injury, and the CNV area was observed using immunofluorescence staining. The expression of miR-204 was analyzed with quantitative real time (qRT)-PCR. In HMECs, exogenous miR-204 agomir or antagomir was used to strengthen or inhibit the expression of miR-204. Migration assays and tube formation studies were conducted to evaluate the function of miR-204 on HMECs.

RESULTS

At 7 days post-alkali burn, CNV grew aggressively into the cornea. MicroRNA-204 expression was reduced in the Alkali group in contrast with the Ctrl group (P = .003). However, miR-204 was upregulated in the Dex group (vs. alkali group, P = .008). The CNV areas in the NTC and miR-204 groups were 59.30 ± 8.32% and 25.60 ± 2.30%, respectively (P = .002). In vitro, miR-204 agomir showed obvious inhibition on HMEC migration in contrast with NTC (P = .033) and miR-204 antagomir (P = .017). Compared with NTC, miR-204 agomir attenuated tube formation, while miR-204 antagomir accelerated HMEC tube formation (P < .05).

CONCLUSION

The role of Dex in attenuating CNV may be partly attributed to miR-204. MiR-204 may be a potential therapeutic target in alkali burn-induced CNV.

Liposomal AntagomiR-155-5p Restores Anti-Inflammatory Macrophages and Improves Arthritis in Preclinical Models of Rheumatoid Arthritis

OBJECTIVE

We previously reported an increased expression of microRNA-155 (miR-155) in the blood monocytes of patients with rheumatoid arthritis (RA) that could be responsible for impaired monocyte polarization to anti-inflammatory M2-like macrophages. In this study, we employed two preclinical models of RA, collagen-induced arthritis and K/BxN serum transfer arthritis, to examine the therapeutic potential of antagomiR-155-5p entrapped within PEGylated (polyethylene glycol [PEG]) liposomes in resolution of arthritis and repolarization of monocytes towards the anti-inflammatory M2 phenotype.

METHODS

AntagomiR-155-5p or antagomiR-control were encapsulated in PEG liposomes of 100 nm in size and -10 mV in zeta potential with high antagomiR loading efficiency (above 80%). Mice were injected intravenously with 1.5 nmol/100 μL PEG liposomes containing antagomiR-155-5p or control after the induction of arthritis.

RESULTS

We demonstrated the biodistribution of fluorescently tagged PEG liposomes to inflamed joints one hour after the injection of fluorescently tagged PEG liposomes, as well as the liver's subsequent accumulation after 48 hours, indicative of hepatic clearance, in mice with arthritis. The injection of PEG liposomes containing antagomiR-155-5p decreased arthritis score and paw swelling compared with PEG liposomes containing antagomiR-control or the systemic delivery of free antagomiR-155-5p. Moreover, treatment with PEG liposomes containing antagomiR-155-5p led to the restoration of bone marrow monocyte defects in anti-inflammatory macrophage differentiation without any significant functional change in other immune cells, including splenic B and T cells.

CONCLUSION

The injection of antagomiR-155-5p encapsulated in PEG liposomes allows the delivery of small RNA to monocytes and macrophages and reduces joint inflammation in murine models of RA, providing a promising strategy in human disease.

MiR-184-5p represses neuropathic pain by regulating CCL1/CCR8 signaling interplay in the spinal cord in diabetic mice

BACKGROUND

Diabetic neuropathic pain (DNP) is a serious complication for diabetic patients involving nervous system. MicroRNAs (miRNAs) are small-noncoding RNAs which are dysregulated in neuropathic pain, and might be critical molecules for pain treatment. Our previous study has shown miR-184-5p was significantly downregulated in DNP. Therefore, the mechanism of miR-184-5p in DNP was investigated in this study.

METHODS

A DNP model was established through streptozotocin (STZ). The pharmacological tools were injected intrathecally, and pain behavior was evaluated by paw withdrawal mechanical thresholds (PWMTs). Bioinformatics analysis, Dual-luciferase reporter assay and fluorescence-in-situ-hybridization (FISH) were used to seek and confirm the potential target genes of miR-184-5p. The expression of relative genes and proteins was analyzed by quantitative reverse transcriptase real-time PCR (qPCR) and western blotting.

RESULTS

MiR-184-5p expression was down-regulated in spinal dorsal on days 7 and 14 after STZ, while intrathecal administration of miR-184-5p agomir attenuates neuropathic pain induced by DNP and intrathecal miR-184-5p antagomir induces pain behaviors in naïve mice. Chemokine CC motif ligand 1 (CCL1) was found to be a potential target of miR-184-5p and the protein expression of CCL1 and the mRNA expression of CCR8 were up-regulated in spinal dorsal on days 7 and 14 after STZ. The luciferase reporter assay and FISH demonstrated that CCL1 is a direct target of miR-184-5p. MiR-184-5p overexpression attenuated the expression of CCL1/CCR8 in DNP; intrathecal miR-184-5p antagomir increased the expression of CCL1/CCR8 in spinal dorsal of naïve mice.

CONCLUSION

This research illustrates that miR-184-5p alleviates DNP through the inhibition of CCL1/CCR8 signaling expression.

MiR-199a-5p enhances neuronal differentiation of neural stem cells and promotes neurogenesis by targeting Cav-1 after cerebral ischemia

AIMS

MicroRNAs (miRs) are involved in endogenous neurogenesis, enhancing of which has been regarded as a potential therapeutic strategy for ischemic stroke treatment; however, whether miR-199a-5p mediates postischemic neurogenesis remains unclear. This study aims to investigate the proneurogenesis effects of miR-199a-5p and its possible mechanism after ischemic stroke.

METHODS

Neural stem cells (NSCs) were transfected using Lipofectamine 3000 reagent, and the differentiation of NSCs was evaluated by immunofluorescence and Western blotting. Dual-luciferase reporter assay was performed to verify the target gene of miR-199a-5p. MiR-199a-5p agomir/antagomir were injected intracerebroventricularly. The sensorimotor functions were evaluated by neurobehavioral tests, infarct volume was measured by toluidine blue staining, neurogenesis was detected by immunofluorescence assay, and the protein levels of neuronal nuclei (NeuN), glial fibrillary acidic protein (GFAP), caveolin-1 (Cav-1), vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF) were measured by Western blotting.

RESULTS

MiR-199a-5p mimic enhanced neuronal differentiation and inhibited astrocyte differentiation of NSCs, while a miR-199a-5p inhibitor induced the opposite effects, which can be reversed by Cav-1 siRNA. Cav-1 was through the dual-luciferase reporter assay confirmed as a target gene of miR-199a-5p. miR-199a-5p agomir in rat stroke models manifested multiple benefits, such as improving neurological deficits, reducing infarct volume, promoting neurogenesis, inhibiting Cav-1, and increasing VEGF and BDNF, which was reversed by the miR-199a-5p antagomir.

CONCLUSION

MiR-199a-5p may target and inhibit Cav-1 to enhance neurogenesis and thus promote functional recovery after cerebral ischemia. These findings indicate that miR-199a-5p is a promising target for the treatment of ischemic stroke.

MiR2233p increases resistance of colorectal cancer cells to 5fluorouracil via targeting SORBS1

OBJECTIVES

5-Fluorouracil (5-FU) is the first-line drug for treating colorectal cancer (CRC), and the resistance of tumor cells to 5-FU is the main cause of chemotherapeutic failure. However, the resistant mechanism is still unclear. This study aims to explore the tumor suppressor genes involved in 5-FU resistance in CRC, and to find the microRNA (miRNA) that regulates these genes.

METHODS

CRC data sets GSE28702 and GSE69657 were downloaded from Gene Expression Omnibus (GEO) database, and gene expression profiles of patients in the FOLFOX chemotherapeutic response group and the non-response group were analyzed, and differential expression genes were identified between the 2 groups. Target gene was then selected. Online bioinformatics databases TargetScan, miRwalk, and miRDB were used to predict miRNA targeting the interested gene sorbin and SH3 domain containing 1 (SORBS1). siSORBS1, HA-SORBS1, miR-223-3p mimic, anti-miR-223-3p, and their corresponding negative controls (siNC, HA, miR-NC, and anti-miR-NC) were transfected into CRC cell lines of HCT116 and SW620 by transient transfection technique, respectively. Co-transfection was done with miRNA and plasmid (miR-NC+HA, miR-223-3p mimic+HA, or miR-223-3p mimic+HA-SORBS1) or anti-miRNA and siRNA (anti-miR-NC+siNC, anti-miR-223-3p+siNC, or anti-miR-223-3p+siSORBS1) in HCT116 cells. Real-time reverse transcription PCR (real-time RT-PCR) and/or Western blotting were used to detect the expression levels of SORBS1 and miR-223-3p in cells. After transfection, the cells were treated with different concentrations of 5-FU, and the cell viability was detected by methyl thiazolyl tetrazolium (MTT) method. The targeting relationship between miR-223-3p and SORBS1 was comfirmed by dual luciferase reporter gene assay.

RESULTS

There were 409 and 528 highly expressed genes in the FOLFOX chemotherapeutic response group of GSE69657 and GSE28702, respectively. There were 22 overlapping genes in the response group, among which exist 3 tumor suppressor genes might be involved in chemosensitivity in CRC, and SORBS1 was selected as the target gene for further study. Three online bioinformatics databases predicted miRNAs targeting SORBS1 and obtained an intersection molecule miR-223-3p. After treatment with 5-FU (25 µmol/L) for 12-36 h, the levels of miR-223-3p in HCT116 and SW620 cells were significantly down-regulated (all P<0.05). After transfection with siSORBS1 or miR-223-3p mimic, the expression levels of SORBS1 in HCT116 and SW620 cells were down-regulated, and the cell viability was increased (all P<0.05). After transfection with HA-SORBS1 or anti-miR-223-3p, the expression levels of SORBS1 in HCT116 and SW620 cells were up-regulated, and the cell viability was decreased (all P<0.05). The result of dual luciferase reporter gene assay showed that the luciferase activity of cells co-transfected with SORBS1 3'-UTR wild plasmid and miR-223-3p mimic was significantly lower than that of the 3'-UTR wild plasmid and miR-NC cells (P<0.05). Compared with co-transfection with miR-223-3p mimic and HA, the cell viability of cells co-transfected with miR-223-3p mimic and HA-SORBS1 was decreased significantly (P<0.01). Compared with the co-transfected anti-miR-223-3p and siNC, the cell viability of the co-transfected anti-miR-223-3p and siSORBS1 was significantly increased (P<0.05).

CONCLUSIONS

MiR-223-3p increases 5-FU resistance in CRC cells by targeting SORBS1,and miR-223-3p is expected to become a new target for clinical treatment of CRC.

Identification of a physiologic vasculogenic fibroblast state to achieve tissue repair

Tissue injury to skin diminishes miR-200b in dermal fibroblasts. Fibroblasts are widely reported to directly reprogram into endothelial-like cells and we hypothesized that miR-200b inhibition may cause such changes. We transfected human dermal fibroblasts with anti-miR-200b oligonucleotide, then using single cell RNA sequencing, identified emergence of a vasculogenic subset with a distinct fibroblast transcriptome and demonstrated blood vessel forming function in vivo. Anti-miR-200b delivery to murine injury sites likewise enhanced tissue perfusion, wound closure, and vasculogenic fibroblast contribution to perfused vessels in a FLI1 dependent manner. Vasculogenic fibroblast subset emergence was blunted in delayed healing wounds of diabetic animals but, topical tissue nanotransfection of a single anti-miR-200b oligonucleotide was sufficient to restore FLI1 expression, vasculogenic fibroblast emergence, tissue perfusion, and wound healing. Augmenting a physiologic tissue injury adaptive response mechanism that produces a vasculogenic fibroblast state change opens new avenues for therapeutic tissue vascularization of ischemic wounds.

Hippocampal miR-206-3p participates in the pathogenesis of depression via regulating the expression of BDNF

As a widely-known neuropsychiatric disorder, the exact pathogenesis of depression remains elusive. MiRNA-206 (miR-206) is conventionally known as one of the myomiRs and has two forms: miR-206-3p and miR-206-5p. Recently, miR-206 has been demonstrated to regulate the biosynthesis of brain-derived neurotrophic factor (BDNF), a very popular target involved in depression and antidepressant responses. Here we assumed that miR-206 may play a role in depression, and various methods including the chronic social defeat stress (CSDS) model of depression, quantitative real-time reverse transcription PCR, western blotting, immuofluorescence and virus-mediated gene transfer were used together. It was found that CSDS robustly increased the level of miR-206-3p but not miR-206-5p in the hippocampus. Both genetic overexpression of hippocampal miR-206-3p and intranasal administration of AgomiR-206-3p induced not only notable depressive-like behaviors but also significantly decreased hippocampal BDNF signaling cascade and neurogenesis in naïve C57BL/6J mice. In contrast, both genetic knockdown of hippocampal miR-206-3p and intranasal administration of AntagomiR-206-3p produced significant antidepressant-like effects in the CSDS model of depression. Furthermore, it was found that the antidepressant-like effects induced by miR-206-3p inhibition require the hippocampal BDNF-TrkB system. Taken together, hippocampal miR-206-3p participates in the pathogenesis of depression by regulating BDNF biosynthesis and is a feasible antidepressant target.

Antagonist targeting miR‑106b‑5p attenuates acute renal injury by regulating renal function, apoptosis and autophagy via the upregulation of TCF4

Acute renal injury (ARI) is a life‑threatening condition and a main contributor to end‑stage renal disease, which is mainly caused by ischemia‑reperfusion (I/R). miR‑106b‑5p is a kidney function‑related miRNA; however, whether miR‑106b‑5p regulates the progression of ARI remains unclear. The present study thus aimed to examine the effects of miR‑106b‑5p antagonist on the regulation of ARI progression. It was found that miR‑106b‑5p expression was upregulated in the renal tissue of rats with I/R‑induced ARI and in NRK‑52E rat renal proximal tubular epithelial cells subjected to hypoxia‑reoxygenation (H/R). In vitro, H/R induction suppressed the proliferation, and promoted the apoptosis and autophagy of NRK‑52E cells, whereas miR‑106b‑5p antagonist (inhibition of miR‑106b‑5p) promoted the proliferation, and attenuated the apoptosis and autophagy of NRK‑52E cells under the H/R condition. Dual luciferase reporter gene assay validated that transcription factor 4 (TCF4) was a target of miR‑106b‑5p. It was further found that TCF4 overexpression promoted the proliferation, and inhibited the apoptosis and autophagy of NRK‑52E cells subjected to H/R. Moreover, the effects of miR‑106b‑5p antagonist on NRK‑52E cell proliferation, apoptosis and autophagy were mediated through the regulation of TCF4. In vivo, miR‑106b‑5p antagonist reduced the severity of renal injury, decreased cell proliferation in renal tissues and lowered the serum creatinine (Scr) and blood urea nitrogen (BUN) levels in the blood samples from rats with I/R‑induced ARI. On the whole, the findings presented herein demonstrate that miR‑106b‑5p antagonist attenuates ARI by promoting the proliferation, and suppressing the apoptosis and autophagy of renal cells via upregulating TCF4.

Role of miR-24 in Multiple Endocrine Neoplasia Type 1: A Potential Target for Molecular Therapy

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant inherited multiple cancer syndrome of neuroendocrine tissues. Tumors are caused by an inherited germinal heterozygote inactivating mutation of the MEN1 tumor suppressor gene, followed by a somatic loss of heterozygosity (LOH) of the MEN1 gene in target neuroendocrine cells, mainly at parathyroids, pancreas islets, and anterior pituitary. Over 1500 different germline and somatic mutations of the MEN1 gene have been identified, but the syndrome is completely missing a direct genotype-phenotype correlation, thus supporting the hypothesis that exogenous and endogenous factors, other than MEN1 specific mutation, are involved in MEN1 tumorigenesis and definition of individual clinical phenotype. Epigenetic factors, such as microRNAs (miRNAs), are strongly suspected to have a role in MEN1 tumor initiation and development. Recently, a direct autoregulatory network between miR-24, MEN1 mRNA, and menin was demonstrated in parathyroids and endocrine pancreas, showing a miR-24-induced silencing of menin expression that could have a key role in initiation of tumors in MEN1-target neuroendocrine cells. Here, we review the current knowledge on the post-transcriptional regulation of MEN1 and menin expression by miR-24, and its possible direct role in MEN1 syndrome, describing the possibility and the potential approaches to target and silence this miRNA, to permit the correct expression of the wild type menin, and thereby prevent the development of cancers in the target tissues.

Therapeutic effects of micro-RNAs in preclinical studies of acute kidney injury: a systematic review and meta-analysis

AKI has a high mortality rate, may lead to chronic kidney disease, and effective therapies are lacking. Micro-RNAs (miRNAs) regulate biologic processes by potently inhibiting protein expression, and pre-clinical studies have explored their roles in AKI. We conducted a systematic review and meta-analysis of miRNAs as therapeutics in pre-clinical AKI. Study screening, data extraction, and quality assessments were performed by 2 independent reviewers. Seventy studies involving 42 miRNA species were included in the analysis. All studies demonstrated significant effects of the miRNA intervention on kidney function and/or histology, with most implicating apoptosis and phosphatase and tensin homolog (PTEN) signaling. Fourteen studies (20.0%) examined the effect of miRNA-21 in AKI, and meta-analysis demonstrated significant increases in serum creatinine and kidney injury scores with miR-21 antagonism and pre-conditioning. No studies reported on adverse effects of miRNA therapy. Limitations also included lack of model diversity (100% rodents, 61.4% ischemia-reperfusion injury), and predominance of male sex (78.6%). Most studies had an unclear risk of bias, and the majority of miRNA-21 studies were conducted by a single team of investigators. In summary, several miRNAs target kidney function and apoptosis in pre-clinical AKI models, with data suggesting that miRNA-21 may mediate protection and kidney repair.Systematic review registration ID: CRD42019128854.

Effect of miR-124 on PI3K/Akt signal pathway in refractory epilepsy rats

This research aimed to investigate the effect of miR-124 on the PI3K/Akt signaling pathway in refractory epilepsy rats. Ten healthy SD rats were selected as a control group, thirty-six successfully established model rats were randomly divided into the model group, mir-124-agomir, mir-124-antagomir, mir-124-agomir+ LY294002 group (combined group), with 9 rats in each group. PI3K or (and) Akt expressions were intervened respectively. The changes in attack latency and cognitive function were observed, and the correlation among miR-124, PI3K, Akt, and attack latency was analyzed. Up-regulation of the level of miR-124 could increase the seizure interval of rats (P&lt; 0.05), improve the cognitive function of rats (P&lt; 0.05), and promote the expression of PI3K, AKT. The level of miR-124, PI3K, Akt was positively correlated with the latent time of seizures in rats, and the level of miR-124 was positively correlated with the level of PI3K, Akt (P&lt; 0.05). In conclusion, miR-124 can play a protective role in temporal lobe epilepsy by promoting PI3K/Akt signaling pathway, including the protection of cognitive function, which may be a potential target for clinical treatment of intractable epilepsy in the future.

MicroRNAs in non-small cell lung cancer: Gene regulation, impact on cancer cellular processes, and therapeutic potential

Lung cancer remains the most lethal cancer among men and women in the United States and worldwide. The majority of lung cancer cases are classified as non-small cell lung cancer (NSCLC). Developing new therapeutics on the basis of better understanding of NSCLC biology is critical to improve the treatment of NSCLC. MicroRNAs (miRNAs or miRs) are a superfamily of genome-derived, small noncoding RNAs that govern posttranscriptional gene expression in cells. Functional miRNAs are commonly dysregulated in NSCLC, caused by genomic deletion, methylation, or altered processing, which may lead to the changes of many cancer-related pathways and processes, such as growth and death signaling, metabolism, angiogenesis, cell cycle, and epithelial to mesenchymal transition, as well as sensitivity to current therapies. With the understanding of miRNA biology in NSCLC, there are growing interests in developing new therapeutic strategies, namely restoration of tumor suppressive miRNAs and inhibition of tumor promotive miRNAs, to combat against NSCLC. In this article, we provide an overview on the molecular features of NSCLC and current treatment options with a focus on pharmacotherapy and personalized medicine. By illustrating the roles of miRNAs in the control of NSCLC tumorigenesis and progression, we highlight the latest efforts in assessing miRNA-based therapies in animal models and discuss some critical challenges in developing RNA therapeutics.

Intrahippocampal miR-342-3p inhibition reduces β-amyloid plaques and ameliorates learning and memory in Alzheimer's disease

Accumulation of extracellular amyloid-β (Aβ) in hippocampal subregions is a hallmark of Alzheimer's disease (AD), which promotes neuronal apoptosis, potentiates cognitive decline and play a causative role in AD pathogenesis. However, whether this process is controlled by distinct miRNAs at the posttranscriptional level remain fascinating but poorly understood. Using post mortem hippocampal samples from human AD patients and 3xTg-AD mouse, we demonstrate that miR-342-3p expression was significantly induced during the AD development. With the aid of intrahippocampal injection of miR-342-3p antagomir, we further show that in vivo miR-342-3p inhibition synergistically improved cognitive deficits in 3xTg-AD mice. The hippocampal Aβ-plaque burden in 3xTg-AD mice, as revealed by immunohistochemical analysis with 4G8 antibody, was attenuated also. Mechanistically, the upregulation of neuronal miR-342-3p is linked to an increase in the activation of the stress kinase c-Jun N-terminal kinase with the subsequent death of the neurons in Aβ-challenged HT22 hippocampal neuronal cells. These findings support the model that derangement of hippocampus signal transduction and subsequent neuronal apoptosis in AD arises as a consequence of increased Aβ burden and chronic activation of the JNK MAPK cascade in a miR-342-3p-dependent manner. Overall, we described for the first time the regulatory activity of miR-342-3p on relevant Aβ metabolism pathways in Alzheimer's disease.

MicroRNAs in cancer cell death pathways: Apoptosis and necroptosis

To protect tissues and the organism from disease, potentially harmful cells are removed through programmed cell death processes, including apoptosis and necroptosis. These types of cell death are critically controlled by microRNAs (miRNAs). MiRNAs are short RNA molecules that target and inhibit expression of many cellular regulators, including those controlling programmed cell death via the intrinsic (Bcl-2 and Mcl-1), extrinsic (TRAIL and Fas), p53-and endoplasmic reticulum (ER) stress-induced apoptotic pathways, as well as the necroptosis cell death pathway. In this review, we discuss the current knowledge of apoptosis and necroptosis pathways and how these are impaired in cancer cells. We focus on how miRNAs disrupt apoptosis and necroptosis, thereby critically contributing to malignancy. Understanding which and how miRNAs and their targets affect cell death pathways could open up novel therapeutic opportunities for cancer patients. Indeed, restoration of pro-apoptotic tumor suppressor miRNAs (apoptomiRs) or inhibition of oncogenic miRNAs (oncomiRs) represent strategies that are currently being trialed or are already applied as miRNA-based cancer therapies. Therefore, better understanding the cancer type-specific expression of apoptomiRs and oncomiRs and their underlying mechanisms in cell death pathways will not only advance our knowledge, but also continue to provide new opportunities to treat cancer.

Pre-treatment with microRNA-181a Antagomir Prevents Loss of Parvalbumin Expression and Preserves Novel Object Recognition Following Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) can result in permanent impairment in memory and learning and may be a precursor to other neurological sequelae. Clinical treatments to ameliorate the effects of mTBI are lacking. Inhibition of microRNA-181a (miR-181a) is protective in several models of cerebral injury, but its role in mTBI has not been investigated. In the present study, miR-181a-5p antagomir was injected intracerebroventricularly 24 h prior to closed-skull cortical impact in young adult male mice. Paw withdrawal, open field, zero maze, Y maze, object location and novel object recognition tests were performed to assess neurocognitive dysfunction. Brains were assessed immunohistologically for the neuronal marker NeuN, the perineuronal net marker wisteria floribunda lectin (WFA), cFos, and the interneuron marker parvalbumin. Protein quantification was performed with immunoblots for synaptophysin and postsynaptic density 95 (PSD95). Fluorescent in situ hybridization was utilized to localize hippocampal miR-181a expression. MiR-181a antagomir treatment reduced neuronal miR-181a expression after mTBI, restored deficits in novel object recognition and increased hippocampal parvalbumin expression in the dentate gyrus. These changes were associated with decreased dentate gyrus hyperactivity indicated by a relative reduction in PSD95 and cFos expression. These results suggest that miR-181a inhibition may be a therapeutic approach to reduce hippocampal excitotoxicity and prevent cognitive dysfunction following mTBI.

MiR-1a-3p mitigates isoproterenol-induced heart failure by enhancing the expression of mitochondrial ND1 and COX1

MicroRNAs (miRNAs) have become potential targets for the treatment of heart failure (HF). It has been shown that miR-1 can reverse cardiac hypertrophy during the compensatory phase of HF development, but it is unknown whether miR-1 can still reverse cardiac dysfunction and improve cardiac remodeling after HF progresses to the decompensation stage. We established a mouse model of isoproterenol-induced HF and then injected miR-1a-3p agomir (agomir-1) into the tail vein. Echocardiography showed that the mice treated with agomir-1 had significantly increased ejection fraction and fractional shortening. These mice also showed a decrease in the N-terminal pro-B type natriuretic peptide (NT-proBNP) levels, but this remained higher than in controls. Cardiac hypertrophy, myocardial fibrosis, apoptosis, and glycogen deposition were reduced in mice treated with agomir-1. Furthermore, we found that supplementation of agomir-1 increased the expression of two mitochondrial DNA-encoded proteins, mitochondrially encoded NADH dehydrogenase 1 (ND1) and mitochondrially encoded cytochrome c oxidase I (COX1). In conclusion, our study found that miR-1a-3p alleviated the symptoms of ISO-induced HF in mice by enhancing mitochondrial ND1 and COX1. The results of this work may provide new therapeutic strategies for the treatment of HF patients.

Hypoxia-Regulated miR-146a Targets Cell Adhesion Molecule 2 to Promote Proliferation, Migration, and Invasion of Clear Cell Renal Cell Carcinoma

BACKGROUND/AIMS

miR-146a has recently been shown to promote cell proliferation, migration, and invasion in many cancers, but the role of miR-146a in clear cell renal cell carcinoma (ccRCC) remains unclear.

METHODS

Reverse transcription quantitative PCR (RT-qPCR) was performed to investigate the mRNA expression of miR-146a and CADM2 in ccRCC tissues. The luciferase reporter assay, Western blotting, and ChIP assay were carried out to explore the promoter and the transcription factor of miR-146a. Moreover, the effect of miR-146a and CADM2 on ccRCC cells was explored using methyl thiazolyl tetrazolium, colony formation, and migration and invasion assays. The luciferase reporter assay, RT-qPCR, western blotting, and immunofluorescence assay were carried out to investigate whether CADM2 is directly regulated by miR-146a. A tumor xenograft model and immunohistochemical staining were used to examine the carcinogenic effect of miR-146a and CADM2 in vivo.

RESULTS

miR-146a has been shown to promote cell proliferation, migration, and invasion. Here, we found that miR-146a is highly expressed in ccRCC tissues, whereas CADM2 is down-regulated. Hypoxia can induce the expression of miR-146a by stimulating its promoter. In addition, we demonstrated that miR-146a promoted and CADM2 inhibited proliferation, migration, and invasion of ccRCC cells. The 3' untranslated region (UTR) luciferase reporter assay identified that miR-146a targeted the 3' UTR of CADM2 and negatively regulated its expression. Ectopic expression of CADM2 counteracted the promoting effect of miR-146a on cell proliferation, migration, invasion, and the epithelial-mesenchymal transition process.

CONCLUSION

Together, the finding of down-regulation of CADM2 by miR-146a can provide new insights into ccRCC pathogenesis and might contribute to the development of novel therapeutic strategies.

MicroRNA-129 and -335 Promote Diabetic Wound Healing by Inhibiting Sp1-Mediated MMP-9 Expression

Diabetic wounds are recalcitrant to healing. However, the mechanism causing this dysfunction is not fully understood. High expression of matrix metalloproteinase-9 (MMP-9) is indicative of poor wound healing. In this study, we show that specificity protein-1 (Sp1), a regulator of MMP-9, binds directly to its promoter and enhances its expression. Additionally, we demonstrated that Sp1 is the direct target of two microRNAs (miRNAs), miR-129 and -335, which are significantly downregulated in diabetic skin tissues. In vitro experiments confirmed that miR-129 or -335 overexpression inhibits MMP-9 promoter activity and protein expression by targeting Sp1, whereas the inhibition of these miRNAs has the opposite effect. The beneficial role of miR-129 or miR-335 in diabetic wound healing was confirmed by the topical administration of miRNA agomirs in diabetic animals. This treatment downregulated Sp1-mediated MMP-9 expression, increased keratinocyte migration, and recovered skin thickness and collagen content. The combined treatment with miR-129 and miR-335 induced a synergistic effect on Sp1 repression and MMP-9 downregulation both in vitro and in vivo. This study demonstrates the regulatory mechanism of Sp1-mediated MMP-9 expression in diabetic wound healing and highlights the potential therapeutic benefits of miR-129 and -335 in delayed wound healing in diabetes.

Potent and selective effect of the mir-10b inhibitor MN-anti-mir10b in human cancer cells of diverse primary disease origin

Since microRNAs (miRNAs, miRs) have been implicated in oncogenesis, many of them have been identified as therapeutic targets. Previously we have demonstrated that miRNA-10b acts as a master regulator of the viability of metastatic tumor cells and represents a target for therapeutic intervention. We designed and synthesized an inhibitor of miR-10b, termed MN-anti-miR10b. We showed that treatment with MN-anti-miR10b led to durable regression/elimination of established metastases in murine models of metastatic breast cancer. Since miRNA-10b has been associated with various metastatic and non-metastatic cancers, in the present study, we investigated the effect of MN-anti-miR10b in a panel of over 600 cell lines derived from a variety of human malignancies. We observed an effect on the viability of multiple cell lines within each cancer type and a mostly dichotomous response with cell lines either strongly responsive to MN-anti-miR10b or not at all even at maximum dose tested, suggesting a very high specificity of the effect. Genomic modeling of the drug response showed enrichment of genes associated with the proto-oncogene, c-Jun.

Topical Lyophilized Targeted Lipid Nanoparticles in the Restoration of Skin Barrier Function following Burn Wound

Lyophilized keratinocyte-targeted nanocarriers (TLN_κ) loaded with locked nucleic acid (LNA) modified anti-miR were developed for topical application to full thickness burn injury. TLN_κ were designed to selectively deliver LNA-anti-miR-107 to keratinocytes using the peptide sequence ASKAIQVFLLAG. TLN_κ employed DOTAP/DODAP combination pH-responsive lipid components to improve endosomal escape. To minimize interference of clearance by non-targeted cells, especially immune cells in the acute wound microenvironment, surface charge was neutralized. Lyophilization was performed to extend the shelf life of the lipid nanoparticles (LNPs). Encapsulation efficiency of anti-miR in lyophilized TLN_κ was estimated to be 96.54%. Cargo stability of lyophilized TLN_κ was tested. After 9 days of loading with anti-miR-210, TLN_κ was effective in lowering abundance of the hypoxamiR miR-210 in keratinocytes challenged with hypoxia. Keratinocyte uptake of DiD-labeled TLN_κ was selective and exceeded 90% within 4 hr. Topical application of hydrogel-dispersed lyophilized TLN_κ encapsulating LNA anti-miR-107 twice a week significantly accelerated wound closure and restoration of skin barrier function. TLN_{κ/anti-miR-107} application depleted miR-107 and upregulated dicer expression, which accelerated differentiation of keratinocytes. Expression of junctional proteins such as claudin-1, loricrin, filaggrin, ZO-1, and ZO-2 were significantly upregulated following TLN_{κ/anti-miR-107} treatment. These LNPs are promising as topical therapeutic agents in the management of burn injury.

MicroRNAs as New Biomarkers for Diagnosis and Prognosis, and as Potential Therapeutic Targets in Acute Myeloid Leukemia

Acute myeloid leukemias (AML) are clonal disorders of hematopoietic progenitor cells which are characterized by relevant heterogeneity in terms of phenotypic, genotypic, and clinical features. Among the genetic aberrations that control disease development there are microRNAs (miRNAs). miRNAs are small non-coding RNAs that regulate, at post-transcriptional level, translation and stability of mRNAs. It is now established that deregulated miRNA expression is a prominent feature in AML. Functional studies have shown that miRNAs play an important role in AML pathogenesis and miRNA expression signatures are associated with chemotherapy response and clinical outcome. In this review we summarized miRNA signature in AML with different cytogenetic, molecular and clinical characteristics. Moreover, we reviewed the miRNA regulatory network in AML pathogenesis and we discussed the potential use of cellular and circulating miRNAs as biomarkers for diagnosis and prognosis and as therapeutic targets.

Apigenin sensitizes hepatocellular carcinoma cells to doxorubic through regulating miR-520b/ATG7 axis

Chemo-resistance is a serious obstacle for successful treatment of cancer. Apigenin, a dietary flavonoid, has been reported as an anticancer drug in various malignant cancers. This study aimed to investigate the potential chemo-sensitization effect of apigenin in doxorubicin-resistant hepatocellular carcinoma cell line BEL-7402/ADM. We observed that apigenin significantly enhanced doxorubicin sensitivity, induced miR-520b expression and inhibited ATG7-dependent autophagy in BEL-7402/ADM cells. In addition, we also showed that miR-520b mimics increased doxorubicin sensitivity and inhibited ATG7-dependent autophagy. Meanwhile, we indicated that ATG7 was a potential target of miR-520b. Furthermore, APG inhibited the growth of hepatocellar carcinoma xenografts in nude mice by up-regulating miR-520b and inhibiting ATG7. Our finding provides evidence that apigenin sensitizes BEL-7402/ADM cells to doxorubicin through miR-520b/ATG7 pathway, which furtherly supports apigenin as a potential chemo-sensitizer for hepatocellular carcinoma.

Development of Novel Therapeutic Agents by Inhibition of Oncogenic MicroRNAs

MicroRNAs (miRs, miRNAs) are regulatory small noncoding RNAs, with their roles already confirmed to be important for post-transcriptional regulation of gene expression affecting cell physiology and disease development. Upregulation of a cancer-causing miRNA, known as oncogenic miRNA, has been found in many types of cancers and, therefore, represents a potential new class of targets for therapeutic inhibition. Several strategies have been developed in recent years to inhibit oncogenic miRNAs. Among them is a direct approach that targets mature oncogenic miRNA with an antisense sequence known as antimiR, which could be an oligonucleotide or miRNA sponge. In contrast, an indirect approach is to block the biogenesis of miRNA by genome editing using the CRISPR/Cas9 system or a small molecule inhibitor. The development of these inhibitors is straightforward but involves significant scientific and therapeutic challenges that need to be resolved. In this review, we summarize recent relevant studies on the development of miRNA inhibitors against cancer.

microRNAs in Parkinson's Disease: From Pathogenesis to Novel Diagnostic and Therapeutic Approaches

Parkinson’s disease (PD) is the most prevalent central nervous system (CNS) movement disorder and the second most common neurodegenerative disease overall. PD is characterized by the progressive loss of dopaminergic (DAergic) neurons in the substantia nigra pars compacta (SNpc) within the midbrain, accumulation of alpha-synuclein (α-SYN) in Lewy bodies and neurites and excessive neuroinflammation. The neurodegenerative processes typically begin decades before the appearance of clinical symptoms. Therefore, the diagnosis is achievable only when the majority of the relevant DAergic neurons have already died and for that reason available treatments are only palliative at best. The causes and mechanism(s) of this devastating disease are ill-defined but complex interactions between genetic susceptibility and environmental factors are considered major contributors to the etiology of PD. In addition to the role of classical gene mutations in PD, the importance of regulatory elements modulating gene expression has been increasingly recognized. One example is the critical role played by microRNAs (miRNAs) in the development and homeostasis of distinct populations of neurons within the CNS and, in particular, in the context of PD. Recent reports demonstrate how distinct miRNAs are involved in the regulation of PD genes, whereas profiling approaches are unveiling variations in the abundance of certain miRNAs possibly relevant either to the onset or to the progression of the disease. In this review, we provide an overview of the miRNAs recently found to be implicated in PD etiology, with particular focus on their potential relevance as PD biomarkers, as well as their possible use in PD targeted therapy.

MiR-630 promotes epithelial ovarian cancer proliferation and invasion via targeting KLF6

OBJECTIVE

MicroRNAs play critical roles in post-translational gene expression. The current study was to investigate the effects of miR-630 in epithelial ovarian cancer.

PATIENTS AND METHODS

Thirty epithelial ovarian cancer tissue and thirty normal ovarian tissue samples were collected and were detected miR-630 expression level with qRT-PCR. MiR-630 mimics, inhibitors and negative controls were transfected into SKOV3 and Cell Counting Kit-8 (CCK-8) assay, and transwell experiment were performed to detect the proliferation rate and migration, respectively. The luciferase reporter assay was utilized to identify miR-630's target gene. Balb/c nude mice were utilized to verify the effect of miR-630 in vivo.

RESULTS

QRT-PCR showed a significantly high miR-630 expression in epithelial ovarian cancer relative to normal ovarian tissue. The miR-630 overexpression promoted epithelial ovarian cancer cell SKOV3 proliferation and migration. Krüppel-like factor 6 (KLF6) was predicted as the target of miR-630. In vivo study also verified that miR-630 overexpression stimulated ovarian cancer growth.

CONCLUSIONS

We propose that targeting miR-630 might be a promising therapeutic approach for ovarian cancer.

MicroRNA-647 Targets SRF-MYH9 Axis to Suppress Invasion and Metastasis of Gastric Cancer

MicroRNAs (miRNAs) play important roles in regulating tumour development and progression. Here we show that miR-647 is repressed in gastric cancer (GC), and associated with GC metastasis. Moreover, we identify that miR-647 can suppress GC cell migration and invasion in vitro. Mechanistically, we confirm miR-647 directly binds to the 3' untranslated regions of SRF mRNA, and SRF binds to the CArG box located at the MYH9 promoter. CCG-1423, an inhibitor of RhoA/SRF-mediated gene transcription, inhibits the expression of MYH9, especially in SRF downregulated cells. Overexpression of miR-647 inhibits MGC 80-3 cells' metastasis in orthotropic GC models, but increasing SRF expression in these cells reverses this change. Importantly, we found the synergistic inhibition effect of CCG-1423 and agomir-647, an engineered miRNA mimic, on cancer metastasis in orthotropic GC models. Our study demonstrates that miR-647 functions as a tumor metastasis suppressor in GC by targeting SRF/MYH9 axis.

MicroRNA-155 promotes the pathogenesis of experimental colitis by repressing SHIP-1 expression

AIM

To explore the mechanism by which microRNA-155 (miR-155) regulates the pathogenesis of experimental colitis.

METHODS

A luciferase assay was performed to confirm the binding of miR-155 to the SHIP-1 3’-UTR. MiR-155 mimics, negative controls and SHIP-1 expression/knockdown vectors were established and then utilized in gain- and loss-of-function studies performed in raw264.7 cells and primary bone marrow-derived macrophages (BMDMs). Thereafter, dextran sulfate sodium (DSS)-induced colitis mouse model with or without antagomiR-155 treatment was established, and the levels of miR-155 and SHIP-1, as well as the pro-inflammatory capabilities, were measured by western blot, quantitative polymerase chain reaction, and immunohistochemistry.

RESULTS

MiR-155 directly bound to the 3’-UTR of SHIP-1 mRNA and induced a significant decrease in SHIP-1 expression in both raw264.7 cells and primary BMDMs. MiR-155 markedly promoted cell proliferation and pro-inflammatory secretions including IL-6, TNF-α, IL-1β, and IFN-γ, whereas these effects could be reversed by the restoration of SHIP-1 expression. In vivo studies showed that antagomiR-155 administration could alleviate DSS-induced intestinal inflammation in Balb/c mice. Moreover, significantly increased SHIP-1 expression, as well as decreased Akt activation and inflammatory response, were observed in the antagomiR-155-treated mice.

CONCLUSION

MiR-155 promotes experimental colitis by repressing SHIP-1 expression. Thus, the inhibition of miR-155 might be a promising strategy for therapy.

MicroRNAs in Neurocognitive Dysfunctions: New Molecular Targets for Pharmacological Treatments?

BACKGROUND

Neurodegenerative and cognitive disorders are multifactorial diseases (i.e., involving neurodevelopmental, genetic, age or environmental factors) characterized by an abnormal development that affects neuronal function and integrity. Recently, an increasing number of studies revealed that the dysregulation of microRNAs (miRNAs) may be involved in the etiology of cognitive disorders as Alzheimer, Parkinson, and Huntington's diseases, Schizophrenia and Autism spectrum disorders.

METHODS

From an extensive search in bibliographic databases of peer-reviewed research literature, we identified relevant published studies related to specific key words such as memory, cognition, neurodegenerative disorders, neurogenesis and miRNA. We then analysed, evaluated and summerized scientific evidences derived from these studies.

RESULTS

We first briefly summarize the basic molecular events involved in memory, a process inherent to cognitive disease, and then describe the role of miRNAs in neurodevelopment, synaptic plasticity and memory. Secondly, we provide an overview of the impact of miRNA dysregulation in the pathogenesis of different neurocognitive disorders, and lastly discuss the feasibility of miRNA-based therapeutics in the treatment of these disorders.

CONCLUSION

This review highlights the molecular basis of neurodegenerative and cognitive disorders by focusing on the impact of miRNAs dysregulation in these pathological phenotypes. Altogether, the published reports suggest that miRNAs-based therapy could be a viable therapeutic alternative to current treatment options in the future.

An Antagomir to MicroRNA-106b-5p Ameliorates Cerebral Ischemia and Reperfusion Injury in Rats Via Inhibiting Apoptosis and Oxidative Stress

We previously observed that microRNA miR-106b-5p significantly increased in serum of patients with acute ischemic stroke. The present study was to determine whether miR-106b-5p antagomir can protect against cerebral ischemia/reperfusion (I/R) injury and elucidate its underlying mechanisms. Middle cerebral artery occlusion (MCAO) was operated on male Sprague Dawley rats. MiR-106b-5p antagomir significantly decreased neurological deficit scores, infarct volumes, and neuronal injury. Furthermore, miR-106b-5p antagomir markedly reduced malondialdehyde (MDA) content, restored superoxide dismutase (SOD) activity, increased the expression of myeloid cell leukemia-1 (Mcl-1) and B cell lymphoma-2 (Bcl-2), and decreased the expression of Bax in the ischemic cortex. In PC12 cells, miR-106b-5p inhibitor increased the Mcl-1 and Bcl-2 expression, which provided protection against glutamate-induced apoptosis and oxidative damage, as evidenced by decreased lactate dehydrogenase (LDH) release, and enhanced SOD activity. Notably, luciferase reported assay proved Mcl-1 was the target gene of miR-106b-5p. In conclusion, our data indicates that the neuroprotective effects of miR-106b-5p antagomir on cerebral I/R injury are associated with its inhibition of apoptosis and oxidative stress, suggesting a potential therapeutic target for ischemic stroke.