MiRNA-based therapeutic potential in multiple sclerosis.

This review will briefly introduce microRNAs (miRNAs) and dissect their contribution to multiple sclerosis (MS) and its clinical outcomes. For this purpose, we provide a concise overview of the present knowledge of MS pathophysiology, biomarkers and treatment options, delving into the role of selectively expressed miRNAs in clinical forms of this disease, as measured in several biofluids such as serum, plasma or cerebrospinal fluid (CSF). Additionally, up-to-date information on current strategies applied to miRNA-based therapeutics will be provided, including miRNA restoration therapy (lentivirus expressing a specific type of miRNA and miRNA mimic) and miRNA inhibition therapy such as antisense oligonucleotides, small molecules inhibitors, locked nucleic acids (LNAs), anti-miRNAs, and antagomirs. Finally, it will highlight future directions and potential limitations associated with their application in MS therapy, emphasizing the need for improved delivery methods and validation of therapeutic efficacy.

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.

MiR-223-3p increases resistance of colorectal cancer cells to 5-fluorouracil via targeting SORBS1. / MiR-223-3p通过靶向SORBS1å¢žåŠ ç»“ç›´è‚ ç™Œç»†èƒžå¯¹5-氟尿嘧啶的耐药性.

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.

Oligochitosan-based nanovesicles for nonalcoholic fatty liver disease treatment via the FXR/miR-34a/SIRT1 regulatory loop.

Non-alcoholic fatty liver disease (NAFLD) is currently a common chronic liver disease worldwide. By now, however, there isn't any FDA-approved specific drug for NAFLD treatment. It has been noticed that farnesoid X receptor (FXR), miR-34a and Sirtuin1 (SIRT1) is related to the occurrence and development of NAFLD. A oligochitosan-derivated nanovesicle (UBC) with esterase responsive degradability was designed to co-encapsulate FXR agonist (obeticholic acid, OCA) and miR-34a antagomir (anta-miR-34a) into the hydrophobic membrane and the center aqueous lumen of nanovesicles, respectively, by dialysis method. The action of UBC/OCA/anta-miR-34a loop on the regulation of lipid deposition via nanovesicles was evaluated on high-fat HepG2 cells and HFD-induced mice. The obtained dual drug-loaded nanovesicles UBC/OCA/anta-miR-34a could enhance the cellular uptake and intracellular release of OCA and anta-miR-34a, leading to the reduced lipid deposition in high-fat HepG2 cells. In NAFLD mice models, UBC/OCA/anta-miR-34a achieved the best curative effect on the recovery of body weight and hepatic function. Meanwhile, in vitro and vivo experiments validated that UBC/OCA/anta-miR-34a effectively activated the expression level of SIRT1 by enhancing the FXR/miR-34a/SIRT1 regulatory loop. This study provides a promising strategy for constructing oligochitosan-derivated nanovesicles to co-deliver OCA and anta-miR-34a for NAFLD treatment. STATEMENT OF SIGNIFICANCE: This study proposed a strategy to construct oligochitosan-derivated nanovesicles to co-deliver obeticholic acid and miR-34a antagomir for NAFLD treatment. Based on the FXR/miR-34a/SIRT1 action loop, this nanovesicle effectively exerted a synergetic effect of OCA and anta-miR-34a to significantly regulate lipid deposition and recover liver function in NAFLD mice.

Transglutaminase-Polyethyleneimine Nanoflowers Mediated Cellular Delivery of Anti-miR-210 for Effective Glioblastoma Therapy.

Glioblastoma (GBM) is a deadly tumor of the central nervous system (CNS) having a dismal prognosis. miRNA-based therapeutics hold immense potential for GBM therapy; however, its delivery remains a daunting challenge. MicroRNA-210 has been established as a critical oncomiR in GBM. Our group has developed novel, PEI-functionalized transglutaminase-based nanoflowers (TGNFs, ∼61 nm in diameter) for the efficient delivery of anti-miR-210 to glioblastoma cells in vitro. TGNFs show low cytotoxicity to normal human fibroblasts, do not affect the liver and kidney health of CD1 mice, and offer >95% anti-miR encapsulation efficiency, serum stability, and protection against polyanion moieties. Their synthesis is cost-effective and does not involve the application of harsh chemicals. TGNFs successfully delivered anti-miR-210 to glioblastoma cells, decreasing cellular proliferation and migration and increasing apoptosis. Overall, this research highlights the potential of TGNFs as delivery agents in miRNA inhibition therapy and encourages further preclinical studies to explore the potential of miR-210 as a therapeutic target in GBM and various other cancers where the oncogenic role of miR-210 has been well-established.

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.

Antitumor Activity of Anti-miR-21 Delivered through Lipid Nanoparticles.

The ability of lipid nanoparticles (LNPs) to deliver nucleic acids have shown a great therapeutic potential to treat a variety of diseases. Here, an optimized formulation of QTsome lipid nanoparticles (QTPlus) is utilized to deliver an anti-miR-21 (AM21) against cancer. The miR-21 downstream gene regulation and antitumor activity is evaluated using mouse and human cancer cells and macrophages. The antitumor activity of QTPlus encapsulating AM21 (QTPlus-AM21) is further evaluated in combination with erlotinib and atezolizumab (ATZ). QTPlus-AM21 demonstrates a superior miR-21-dependent gene regulation and eventually inhibits A549 non-small cell lung cancer growth in vitro. QTPlus-AM21 further induces chemo-sensitization of A549 cells to erlotinib with a combination index of 0.6 in inhibiting A549 cell growth. When systemically administers to MC38 tumor-bearing mouse model, QTPlus-AM21 exhibits an antitumor immune response with over 80% tumor growth inhibition (TGI%) and over twofold and fourfold PD-1 and PD-L1 upregulation in tumors and spleens. The combination therapy of QTPlus-AM21 and ATZ further shows a higher antitumor response (TGI% over 90%) and successfully increases M1 macrophages and CD8 T cells into TME. This study provides new insights into the antitumor mechanism of AM21 and shows great promise of QTPlus-AM21 in combination with chemotherapies and immunotherapies.

Anti-hsa-miR-59 alleviates premature senescence associated with Hutchinson-Gilford progeria syndrome in mice.

Hutchinson-Gilford progeria syndrome (HGPS) is a lethal premature aging disorder without an effective therapeutic regimen. Because of their targetability and influence on gene expression, microRNAs (miRNAs) are attractive therapeutic tools to treat diseases. Here we identified that hsa-miR-59 (miR-59) was markedly upregulated in HGPS patient cells and in multiple tissues of an HGPS mouse model (LmnaG609G/G609G ), which disturbed the interaction between RNAPII and TFIIH, resulting in abnormal expression of cell cycle genes by targeting high-mobility group A family HMGA1 and HMGA2. Functional inhibition of miR-59 alleviated the cellular senescence phenotype of HGPS cells. Treatment with AAV9-mediated anti-miR-59 reduced fibrosis in the quadriceps muscle, heart, and aorta, suppressed epidermal thinning and dermal fat loss, and yielded a 25.5% increase in longevity of LmnaG609G/G609G mice. These results identify a new strategy for the treatment of HGPS and provide insight into the etiology of HGPS disease.

MicroRNA-155-5p Aggravates Adriamycin-Induced Focal Segmental Glomerulosclerosis through Targeting Nrf2.

INTRODUCTION: Focal segmental glomerulosclerosis (FSGS) is characterized by focal and segmental obliteration of glomerular capillary tufts with increased matrix and usually associated with nephrotic range proteinuria. FSGS is a huge burden to society; however, the mechanisms remain unclear and treatment is still lacking. METHODS: Adriamycin nephropathy was induced by Adriamycin injection and some mice were also injected with Anti-miR-155-5p LNA or YC-1 (a pharmacological inhibitor of HIF-1). At 6 weeks, the mice were sacrificed, and kidneys, blood and urine samples were collected for further analysis. RESULTS: We demonstrated a significant increase of miR-155-5p in kidney tissues in Adriamycin-induced FSGS mouse models. We also found Adriamycin treatment led to the activation of HIF-1, and inhibition of HIF-1 using YC-1 partly prevented the induction of miR-155-5p. Functionally, anti-miR-155-5p attenuated kidney injury and delayed the progression of renal fibrosis. Further, anti-miR-155-5p also enhanced the expression of Nrf2 following Adriamycin treatment. Further, our luciferase microRNA target reporter assay verified Nrf2 as a direct target of miR-155-5p. Our further results indicated anti-miR-155-5p could suppress kidney oxidative stress and inflammation, also supporting Nrf2 was the direct target of miR-155-5p. Finally, we also found miR-155-5p did not increase in serum but significantly increased in urine, indicating urinary miR-155-5p may be useful for FSGS diagnosis. CONCLUSION: This study identified a HIF-1/miR-155-5p/Nrf2 axis which can promote kidney oxidative stress and inflammation, finally aggravating kidney injury and accelerating the progression of renal fibrosis in FSGS. Moreover, the increase in urinary miR-155-5p may be useful for the diagnosis of FSGS.

miR-328-3p Affects Axial Length Via Multiple Routes and Anti-miR-328-3p Possesses a Potential to Control Myopia Progression.

Purpose: We previously reported miR-328-3p as a novel risk factor for myopia through a genetic association study of the PAX6 gene. In the present study, we first explored the effects of miR-328-3p on other myopia-related genes, and then tested whether anti-miR-328-3p may be used for myopia control. Methods: The luciferase report assay and transient transfection were used to confirm miR-328-3p target genes. The chromatin immunoprecipitation (ChIP) assay was used to investigate retinoic acid receptor on the miR-328-3p promoter. Mice and pigmented rabbits were induced to have myopia by the form deprivation method, and then anti-miR-328-3p oligonucleotide was topically instilled to the myopic eyes. The axial length was measured to assess the therapeutic effect of anti-miR-328-3p. A toxicity study using much higher doses was conducted to assess the safety and ocular irritation of anti-miR-328-3p. Results: The report assay and transfection of miR-328-3p mimic confirmed that miR-328-3p dose-dependently decreased both mRNA and protein expression of fibromodulin (FMOD) and collagen1A1 (COL1A1). We subsequently showed that FMOD promoted TGF-ß1 expression, and overexpression of FMOD increased the phosphorylation levels of p38-MAPK and JNK. The ChIP study showed that retinoic acid binds to miR-328-3p promoter and up-regulates miR-328-3p expression. In myopic animal studies, anti-miR-328-3p was as effective as 1% atropine and had a dose-dependent effect on suppressing axial elongation. In the toxicity study, anti-miR-328-3p did not cause any unwanted effects in the eyes or other organs. Conclusions: Micro (mi)R-328-3p affects myopia development via multiple routes. anti-miR-328-3p possesses a potential as a novel therapy for myopia control.

Inhibition of microRNA-33b specifically ameliorates abdominal aortic aneurysm formation via suppression of inflammatory pathways.

Abdominal aortic aneurysm (AAA) is a lethal disease, but no beneficial therapeutic agents have been established to date. Previously, we found that AAA formation is suppressed in microRNA (miR)-33-deficient mice compared with wild-type mice. Mice have only one miR-33, but humans have two miR-33 s, miR-33a and miR-33b. The data so far strongly support that inhibiting miR-33a or miR-33b will be a new strategy to treat AAA. We produced two specific anti-microRNA oligonucleotides (AMOs) that may inhibit miR-33a and miR-33b, respectively. In vitro studies showed that the AMO against miR-33b was more effective; therefore, we examined the in vivo effects of this AMO in a calcium chloride (CaCl2)-induced AAA model in humanized miR-33b knock-in mice. In this model, AAA was clearly improved by application of anti-miR-33b. To further elucidate the mechanism, we evaluated AAA 1 week after CaCl2 administration to examine the effect of anti-miR-33b. Histological examination revealed that the number of MMP-9-positive macrophages and the level of MCP-1 in the aorta of mice treated with anti-miR-33b was significantly reduced, and the serum lipid profile was improved compared with mice treated with control oligonucleotides. These results support that inhibition of miR-33b is effective in the treatment for AAA.

Poly-antioxidants for enhanced anti-miR-155 delivery and synergistic therapy of metastatic breast cancer.

Despite the great progress in the control of primary tumor growth, metastasis remains the major challenge of breast cancer therapy in clinics, which is highly related to the upregulation of reactive oxygen species (ROS) and overexpression of its relevant pro-survival miR-155 gene. Therefore, we fabricated a poly-antioxidant (FTP) to deliver anti-miR-155 for synergistic treatment of metastatic breast cancer by ROS scavenging and miR-155 inhibition. FTP was synthesized by the polymerization of fluorated-polyethyleneimine (FPEI) and antioxidants (TEMPOL), using a glutathione (GSH) responsive linker for controlled drug release. Notably, the poly-drug strategy could not only promote the tumoral accumulation of small molecular antioxidants but also enhance the transfection efficiency of anti-miR-155 owing to the hydrophobic property of TEMPOL. After synergistic treatment, the NF-κB pathway was significantly blocked, thereby generating strong anti-metastatic ability both in vitro and in vivo. The poly-antioxidant could be a new type of nanoplatform for highly efficient and safe miRNA delivery, which also provides a promising strategy for the synergistic treatment of metastatic breast cancer.

Targeted Suppression of miRNA-33 Using pHLIP Improves Atherosclerosis Regression.

BACKGROUND: miRNA therapeutics have gained attention during the past decade. These oligonucleotide treatments can modulate the expression of miRNAs in vivo and could be used to correct the imbalance of gene expression found in human diseases such as obesity, metabolic syndrome, and atherosclerosis. The in vivo efficacy of current anti-miRNA technologies hindered by physiological and cellular barriers to delivery into targeted cells and the nature of miRNAs that allows one to target an entire pathway that may lead to deleterious off-target effects. For these reasons, novel targeted delivery systems to inhibit miRNAs in specific tissues will be important for developing effective therapeutic strategies for numerous diseases including atherosclerosis. METHODS: We used pH low-insertion peptide (pHLIP) constructs as vehicles to deliver microRNA-33-5p (miR-33) antisense oligonucleotides to atherosclerotic plaques. Immunohistochemistry and histology analysis was performed to assess the efficacy of miR-33 silencing in atherosclerotic lesions. We also assessed how miR-33 inhibition affects gene expression in monocytes/macrophages by single-cell RNA transcriptomics. RESULTS: The anti-miR-33 conjugated pHLIP constructs are preferentially delivered to atherosclerotic plaque macrophages. The inhibition of miR-33 using pHLIP-directed macrophage targeting improves atherosclerosis regression by increasing collagen content and decreased lipid accumulation within vascular lesions. Single-cell RNA sequencing analysis revealed higher expression of fibrotic genes (Col2a1, Col3a1, Col1a2, Fn1, etc) and tissue inhibitor of metalloproteinase 3 (Timp3) and downregulation of Mmp12 in macrophages from atherosclerotic lesions targeted by pHLIP-anti-miR-33. CONCLUSIONS: This study provides proof of principle for the application of pHLIP for treating advanced atherosclerosis via pharmacological inhibition of miR-33 in macrophages that avoid the deleterious effects in other metabolic tissues. This may open new therapeutic opportunities for atherosclerosis-associated cardiovascular diseases via selective delivery of other protective miRNAs.

Emerging therapeutic targets for epilepsy: preclinical insights.

INTRODUCTION: Around 30% of patients with epilepsy suffer from drug-resistant seizures. Drug-resistant seizures may have significant consequences such as sudden death in epilepsy, injuries, memory disturbances, and childhood learning and developmental problems. Available antiepileptic drugs (AEDs) work via numerous mechanisms - mainly through inhibition of voltage-operated Na+ and/or Ca2+ channels, excitation of K+ channels, enhancement of GABA-mediated inhibition and/or blockade of glutamate-produced excitation. However, the discovery and development of novel brain targets may improve the future pharmacological management of epilepsy and hence is of pivotal importance. AREAS COVERED: This article examines novel drug targets such as brain multidrug efflux transporters and inflammatory pathways; it progresses to discuss possible strategies for the management of drug-resistant seizures. Reduction of the consequences of blood brain barrier dysfunction and enhancement of anti-oxidative defense are discussed. EXPERT OPINION: Novel drug targets comprise brain multidrug efflux transporters, TGF-ß, Nrf2-ARE or m-TOR signaling and inflammatory pathways. Gene therapy and antagomirs seem the most promising targets. Epileptic foci may be significantly suppressed by viral-vector-mediated gene transfer, leading to an increased in situ concentration of inhibitory factors (for instance, galanin). Also, antagomirs offer a promising possibility of seizure inhibition by silencing micro-RNAs involved in epileptogenesis and possibly in seizure generation.

microRNA-671-5p reduces tumorigenicity of ovarian cancer via suppressing HDAC5 and HIF-1α expression.

OBJECTIVE: microRNA (miR)-based therapeutic reference has been established and expanded in the treatment of cancers. For this reason, we explored how miR-671-5p regulated tumorigenicity of ovarian cancer (OC) through regulating histone deacetylase 5 (HDAC5) and hypoxia-inducible factor-1α (HIF-1α). METHODS: miR-671-5p, HDAC5 and HIF-1α expression levels were determined in OC clinical tissues. The OC cell line H8910 was screened and transfected with the vectors that altered miR-671-5p, HDAC5 and HIF-1α levels. Finally, the proliferation, migration, invasion and apoptosis of the transfected H8910 cells were determined and the role of miR-671-5p and HDAC5 in vivo tumor growth was further discussed. RESULTS: Low expression miR-671-5p and high expression HDAC5 and HIF-1α levels were tested in OC tissues. Up-regulating miR-671-5p or down-regulating HDAC5 or HIF-1α suppressed proliferation, migration, invasion and augmented apoptosis of H8910 cells while silenced miR-671-5p or enhanced HDAC5 caused the opposite consequences. Overexpression of HDAC5 reduced while depletion of HDAC5 enhanced the influence of up-regulated miR-671-5p on OC cell growth. In animal models, suppressing miR-671-5p or promoting HDAC5 encouraged OC tumor growth. CONCLUSION: A summary delineates that miR-671-5p reduces tumorigenicity of OC via suppressing HDAC5 and HIF-1α expression levels.

Reexamining assumptions about miRNA-guided gene silencing.

MicroRNAs (miRNAs) are short endogenously expressed RNAs that have the potential to regulate the expression of any RNA. This potential has led to the publication of several thousand papers each year connecting miRNAs to many different genes and human diseases. By contrast, relatively few papers appear that investigate the molecular mechanism used by miRNAs. There is a disconnect between rigorous understanding of mechanism and the extraordinary diversity of reported roles for miRNAs. Consequences of this disconnect include confusion about the assumptions underlying the basic science of human miRNAs and slow development of therapeutics that target miRNAs. Here, we present an overview of investigations into miRNAs and their impact on gene expression. Progress in our understanding of miRNAs would be aided by a greater focus on the mechanism of miRNAs and a higher burden of evidence on researchers who seek to link expression of a particular miRNA to a biological phenotype.

MicroRNA Therapy for Dry Eye Disease.

Purpose: We tested the role of microRNA-328 in dry eye disease (DED). Benzalkonium chloride (BAC) has been used to induce DED in animal models. We first demonstrated that both BAC and hyperosmotic stress induced overexpression of miR-328 in corneal cells and then tested whether anti-miR-328 could be a new therapy. Methods: BAC was instilled to both eyes of 41 rabbits and 19 mice from day 0 to 21 to induce DED. Animals of each species were divided to receive topical instillation of saline or anti-miR-328 eye drops between day 8 and 21. The DED signs were assessed by corneal fluorescein staining, histological examination, apoptosis of corneal cells, and inflammatory cytokines in rabbit eyes. For mice, only corneal fluorescein staining was assessed for the therapeutic effects. The corneal fluorescein staining scores ranged from 0 of no staining to 4 of coalescent. Results: For the rabbits, the staining score was significantly reduced (P = 0.038) after the 14-day anti-miR-328 treatment (n = 42 eyes), but the score was not improved by saline treatment (n = 40 eyes). Furthermore, rabbit eyes treated with anti-miR-328 had thicker corneal epithelium (P = 9.4 × 10-5), fewer apoptotic cells in corneal epithelium (P = 0.002), and stroma (P = 0.029) compared with the saline-treated eyes. Anti-miR-328 was more effective than saline to reduce the block of orifices of Meibomian glands, although such an effect was only marginally significant (P = 0.059). Similarly, anti-miR-328 was more effective than saline in reducing corneal staining in mouse eyes (P = 0.005). Conclusion: Overexpression of miR-328 may contribute to DED. Anti-miR-328 protects corneal cells and promotes re-epithelialization for DED treatment.

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.