miRNA-17 members that target Bmpr2 influence signaling mechanisms important for embryonic stem cell differentiation in vitro and gastrulation in embryos

Unraveling Therapeutic Opportunities and the Diagnostic Potential of microRNAs for Human Lung Cancer

Lung cancer is a major public health problem and a leading cause of cancer-related deaths worldwide. Despite advances in treatment options, the five-year survival rate for lung cancer patients remains low, emphasizing the urgent need for innovative diagnostic and therapeutic strategies. MicroRNAs (miRNAs) have emerged as potential biomarkers and therapeutic targets for lung cancer due to their crucial roles in regulating cell proliferation, differentiation, and apoptosis. For example, miR-34a and miR-150, once delivered to lung cancer via liposomes or nanoparticles, can inhibit tumor growth by downregulating critical cancer promoting genes. Conversely, miR-21 and miR-155, frequently overexpressed in lung cancer, are associated with increased cell proliferation, invasion, and chemotherapy resistance. In this review, we summarize the current knowledge of the roles of miRNAs in lung carcinogenesis, especially those induced by exposure to environmental pollutants, namely, arsenic and benzopyrene, which account for up to 1/10 of lung cancer cases. We then discuss the recent advances in miRNA-based cancer therapeutics and diagnostics. Such information will provide new insights into lung cancer pathogenesis and innovative diagnostic and therapeutic modalities based on miRNAs.

Non-Coding RNAs as Biomarkers for Embryo Quality and Pregnancy Outcomes: A Systematic Review and Meta-Analysis

Despite advances in in vitro fertilization (IVF), there is still a lack of non-invasive and reliable biomarkers for selecting embryos with the highest developmental and implantation potential. Recently, small non-coding RNAs (sncRNAs) have been identified in biological fluids, and extracellular sncRNAs are explored as diagnostic biomarkers in the prediction of IVF outcomes. To determine the predictive role of sncRNAs in embryo quality and IVF outcomes, a systematic review and meta-analysis was performed. Articles were retrieved from PubMed, EMBASE, and Web of Science from 1990 to 31 July 2022. Eighteen studies that met the selection criteria were analyzed. In total, 22 and 47 different sncRNAs were found to be dysregulated in follicular fluid (FF) and embryo spent culture medium (SCM), respectively. MiR-663b, miR-454 and miR-320a in FF and miR-20a in SCM showed consistent dysregulation in two different studies. The meta-analysis indicated the potential predictive performance of sncRNAs as non-invasive biomarkers, with a pooled area under curve (AUC) value of 0.81 (95% CI 0.78, 0.844), a sensitivity of 0.79 (95% CI 0.72, 0.85), a specificity of 0.67 (95% CI 0.52, 0.79) and a diagnostic odds ratio (DOR) of 8 (95% CI 5, 12). Significant heterogeneity was identified among studies in sensitivity (I2  =  46.11%) and specificity (I2  =  89.73%). This study demonstrates that sncRNAs may distinguish embryos with higher developmental and implantation potentials. They can be promising non-invasive biomarkers for embryo selection in ART. However, the significant heterogeneity among studies highlights the demand for prospective multicenter studies with optimized methods and adequate sample sizes in the future.

CiRS-187 regulates BMPR2 expression by targeting miR-187 in bovine cumulus cells treated with BMP15 and GDF9

Circular RNAs (circRNAs) play vital roles in regulating biological processes. However, the contributions of circRNAs to BMPR2 regulation during follicle development remain unknown. In this study, we first verified the optimal conditions for BMP15 and GDF9 treatment in bovine cumulus cells. Then, we screened and identified candidate microRNAs (miRNAs) that may target the BMPR2 3'UTR with TargetScan, a luciferase reporter assay and RT-qPCR. Next, we transfected miR-187 into bovine cumulus cells, and the results showed that miR-187 regulated BMPR2 and inhibited its expression. To explore the competing endogenous RNA (ceRNA) mechanism, we predicted the sponging circRNAs of miR-187 and identified ciRS-187. We further detected miR-187 and BMPR2 expression and apoptosis levels upon knockdown of ciRS-187 and found that ciRS-187 upregulated BMPR2 expression. The results provide a theoretical basis for a ceRNA mechanism of circRNAs related to follicle development.

Cardiac inducing colonies halt fibroblast activation and induce cardiac/endothelial cells to move and expand via paracrine signaling

Myocardial fibrosis (MF), a common event that develops after myocardial infarction, initially is a reparative process but eventually leads to heart failure and sudden cardiac arrest. In MF, the infarct area is replaced by a collagenous-based scar induced by "excessive" collagen deposition from activated cardiac fibroblasts. The scar prevents ventricular wall thinning; however, over time it expands to noninfarcted myocardium. Therapies to prevent fibrosis include reperfusion, anti-fibrotic agents, and ACE inhibitors. Paracrine factor (PF)/stem cell research has recently gained significance as a therapy. We consistently find that cardiac inducing colonies (CiCs) (derived from human germline pluripotent stem cells) secrete PFs at physiologically relevant concentrations that suppress cardiac fibroblast activation and excessive extracellular matrix protein secretion. These factors also affect human cardiomyocytes and endothelial cells by inducing migration/proliferation of both populations into a myocardial wound model. Finally, CiC factors modulate matrix turnover and proinflammation. Taking the results together, we show that CiCs could help tip the balance from fibrosis toward repair.

Reversing Cardiac Hypertrophy at the Source Using a Cardiac Targeting Peptide Linked to miRNA106a: Targeting Genes That Cause Cardiac Hypertrophy

Causes and treatments for heart failure (HF) have been investigated for over a century culminating in data that have led to numerous pharmacological and surgical therapies. Unfortunately, to date, even with the most current treatments, HF remains a progressive disease with no therapies targeting the cardiomyocytes directly. Technological advances within the past two to three years have brought about new paradigms for treating many diseases that previously had been extremely difficult to resolve. One of these new paradigms has been a shift from pharmacological agents to antisense technology (e.g., microRNAs) to target the molecular underpinnings of pathological processes leading to disease onset. Although this paradigm shift may have been postulated over a decade ago, only within the past few years has it become feasible. Here, we show that miRNA106a targets genes that, when misregulated, have been shown to cause hypertrophy and eventual HF. The addition of miRNA106a suppresses misexpressed HF genes and reverses hypertrophy. Most importantly, using a cardiac targeting peptide reversibly linked to miRNA106a, we show delivery is specific to cardiomyocytes.

miR-17-5p attenuates kidney ischemia-reperfusion injury by inhibiting the PTEN and BIM pathways

Background

Kidney ischemia-reperfusion (I/R) injury is an independent risk factor for delayed graft function after kidney transplantation with long-term graft survival deterioration. Previously, we found that the upregulated expression of miR-17-5p exerts a protective effect in kidney I/R injury, but the mechanism has not been clearly studied.

Methods

A kidney I/R injury model was induced in adult C57BL/6 male mice (20–22 g) by clamping both kidney pedicles for 30 min. The miR-17-5p agomir complex was injected into mice 24 h before surgery via the tail vein at a total injection volume of 10 µL/g body weight. The mice were euthanized on post-I/R injury day 2, and kidney function, apoptosis, autophagy, and related molecules were then detected. Human kidney-2 (HK-2) cells, which underwent hypoxia/reoxygenation, were treated with the miR-17-5p agomir, miR-17-5p antagomir, and small interfering ribonucleic acids (siRNAs). Cell viability, apoptosis, autophagy, and molecules were also examined.

Results

Autophagy, miR-17-5p expression, and kidney function damage were significantly more increased in the I/R group than in the sham group. In the cultured HK-2 cells underwent hypoxia/reoxygenation, the miR-17-5p agomir directly inhibited the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and Bcl-2 like protein 11 (BIM), and attenuated apoptosis and autophagy. Further, miR-17-5p inhibited autophagy by activating the protein kinase B (Akt)/Beclin1 pathway, which was suppressed by siRNAs. Additionally, the administration of miR-17-5p agomir greatly improved kidney function in the I/R mice group by inhibiting autophagy and apoptosis.

Conclusions

These findings suggest a new possible therapeutic strategy for the prevention and treatment of kidney I/R injury. The upregulation of miR-17-5p expression appears to inhibit apoptosis and autophagy by suppressing PTEN and BIM expression, which in turn upregulates downstream Akt/Beclin1 expression.

MiR-17 Knockdown Promotes Vascular Smooth Muscle Cell Phenotypic Modulation Through Upregulated Interferon Regulator Factor 9 Expression

BACKGROUND

MiR-17 is a small noncoding RNA that plays an important role in the development of tumorgenesis, which recently has emerged to be involved in regulation of inflammatory responses and angiogenesis. However, the effect and underlying mechanism of miR-17 on vascular smooth muscle cell (VSMC) phenotypic modulation have not been investigated.

METHODS AND RESULTS

In the current study, we observed that miR-17 expression tested by real-time polymerase chain reaction (RT-PCR) was downregulated in VSMCs administrated with platelet-derived growth factor-BB stimulation and carotid arteries subjected to wire injury, which were accompanied with decreased VSMC differentiation markers. Loss-of-function strategy demonstrated that miR-17 knockdown promoted VSMC phenotypic modulation characterized as decreased VSMC differentiation marker genes, increased proliferated and migrated capability of VSMC examined by RT-PCR and western blot analysis. Mechanistically, the bioinformatics analysis and luciferase assay demonstrated that miR-17 directly targeted Interferon Regulator Factor 9 (IRF9) and the upregulated IRF9 expression was responsible for the promoted effect miR-17 knockdown on VSMC phenotypic modulation.

CONCLUSIONS

Taken together, our results demonstrated that miR-17 knockdown accelerated VSMC phenotypic modulation partially through directly targeting to IRF9, which suggested that miR-17 may act as a novel therapeutic target for intimal hyperplasia management.

Novel Advances in Modifying BMPR2 Signaling in PAH

Pulmonary Arterial Hypertension (PAH) is a disease of the pulmonary arteries, that is characterized by progressive narrowing of the pulmonary arterial lumen and increased pulmonary vascular resistance, ultimately leading to right ventricular dysfunction, heart failure and premature death. Current treatments mainly target pulmonary vasodilation and leave the progressive vascular remodeling unchecked resulting in persistent high morbidity and mortality in PAH even with treatment. Therefore, novel therapeutic strategies are urgently needed. Loss of function mutations of the Bone Morphogenetic Protein Receptor 2 (BMPR2) are the most common genetic factor in hereditary forms of PAH, suggesting that the BMPR2 pathway is fundamentally important in the pathogenesis. Dysfunctional BMPR2 signaling recapitulates the cellular abnormalities in PAH as well as the pathobiology in experimental pulmonary hypertension (PH). Approaches to restore BMPR2 signaling by increasing the expression of BMPR2 or its downstream signaling targets are currently actively explored as novel ways to prevent and improve experimental PH as well as PAH in patients. Here, we summarize existing as well as novel potential treatment strategies for PAH that activate the BMPR2 receptor pharmaceutically or genetically, increase the receptor availability at the cell surface, or reconstitute downstream BMPR2 signaling.

Molecular targeting of vulnerable RNA sequences in SARS CoV-2: identifying clinical feasibility

Covid-19 (SARS CoV-2) has become a deadly, world-wide pandemic. Although most who are infected survive, complications from the virus can be pronounced and long-lasting. To date, of all the respiratory viruses including influenza and coronaviruses, only influenza has had a drug (i.e., Tamiflu) specifically targeted to treat and prevent infection. As a result, additional agents that specifically target viral production and are clinically feasible are needed to alleviate respiratory viral infections. The idea of using a miRNA/siRNA molecular approach for treating various diseases was postulated over a decade ago; however, only within the past few years has it become feasible. One technological advancement has been the molecular linkage of lipophilic moieties to mi/siRNAs in order to bypass the need for enveloping these inhibitory RNAs in lipid-based transfection reagents, which could irritate the airway if inhaled. Here we show that siRNAs and miRNAs inhibit SARS CoV-2 spike protein production in a dose-dependent manner in both HEK293 cells and a primary human airway tracheal cell line. We also show that this inhibition is equally robust using a clinically relevant siRNA that does not need to be prepped with a transfection reagent.

A miR-511-binding site SNP in the 3'UTR of IGF-1 gene is associated with proliferation and apoptosis of PK-15 cells

Insulin-like growth factor-1 (IGF-1) is a functional candidate gene for pig growth and development due to its crucial role in the growth axis of growth hormone-IGF-1. Considering that the 3' untranslated region (3'UTR) of gene may affect its expression, we analyzed the effect of a single-nucleotide polymorphism (SNP) (rs34142920, c.674C > T) on gene expression, cell proliferation, and apoptosis and the possible related molecular mechanisms in PK-15 cells. The SNP was found in the 3'UTR of IGF-1 in Bama Xiang pig in previous investigations. Results showed that the SNP was located at the target site binding to microRNA (miR-511). The 3'UTR of IGF-1 gene with C allele significantly downregulated the expression of IGF-1 gene compared with that of the gene with T allele by luciferase assay. miR-511 was transfected into porcine kidney cell line (PK-15 cells) to reveal its effects on cells and whether or not it targets IGF-1. The expression levels of IGF-1 at mRNA and protein levels were remarkably downregulated. miR-511 significantly inhibited cell proliferation and promoted cell apoptosis by downregulating the phosphorylation level of AKT and ERK1/2. This finding confirmed that miR-511 inhibits proliferation and promotes apoptosis by downregulating the IGF-1 in PK-15 cells.

Comparison of miRNA expression profiles in individuals with chronic or aggressive periodontitis

OBJECTIVES

MicroRNAs (miRNAs) may play an important role in inflammatory response. However, the involvement of miRNAs in the pathogenesis of periodontitis is unclear. The present study aimed to compare the miRNA expression profiles in individuals with chronic (CP) or aggressive (AP) periodontitis.

MATERIALS AND METHODS

Eighteen non-smoker individuals (CP = 9 and AP = 9) without any history of systemic diseases or previous periodontal therapies were selected at the Clinics of Periodontology from the Federal University of Minas Gerais. Gingival tissue samples were collected during the initial periodontal therapy. miRNAs were isolated, and expression patterns of 754 miRNAs were assessed with a quantitative miRNA PCR array. miRNAs expression profiles were compared between CP and AP groups.

RESULTS

There were no differences observed in the miRNAs expression profiles between CP and AP (p > 0.05). According to the microarray analyses, the most expressed miRNAs in both groups were hsa-miR-1274b, hsa-let-7b-5p, hsa-miR-24-3p, hsa-miR-19b-3p, hsa-miR-720, hsa-miR-126-3p, hsa-miR-17-3p and hsa-miR-21-3p.

CONCLUSION

Findings suggested no differences in miRNAs expression profiles between chronic and aggressive forms of periodontitis. The overexpression of specific miRNAs could provide insights into the pathogenesis of both forms of the disease.

MiRNA-17 encoded by the miR-17-92 cluster increases the potential for steatosis in hepatoma cells by targeting CYP7A1

Background

The miRNA cluster miR-17-92 is known to act as an oncogene in various cancers. Members of this cluster were also found to be involved in some other pathological process, such as steatosis, which is a pivotal event in the initiation and progression of nonalcoholic fatty liver disease (NAFLD). This study aimed to explore whether miR-17, one of the most functional miRNAs in the miR-17-92 family, participates in the process of steatosis in hepatoma cells.

Methods

We developed both a miR-17-expressing transgenic mouse model and a miR-17-expressing HepG2 cell model, the latter was established via stable transfection. Real-time PCR and western blot were applied to measure the expression levels of miR-17 and the potential target gene CYP7A1. The luciferase assay was used to confirm direct binding of miR-17 and CYP7A1. The oleic acid induction assay and Oil-Red-O staining were performed to support the determination of steatotic changes in HepG2 cell.

Results

Extensive steatotic changes were observed in the livers of transgenic mice. Fewer were seen in the wild-type animals. CYP7A1 was confirmed as a target gene of miR-17, and the expression of CYP7A1 was found to be negatively regulated in both the transgenic mice liver cells and the miR-17-expressing HepG2 cells. CYP7A1 was found to participate in miR-17-induced steatosis, as its repressed expression in miR-17 HepG2 cells exacerbated steatotic change. Re-introduction of CYP7A1 into miR-17 HepG2 cell partially alleviated steatosis.

Conclusions

miR-17 is a novel regulator of CYP7A1 signaling in hepatic lipid metabolism, suggesting a potential therapeutic approach for fatty liver.

Electronic supplementary material

The online version of this article (10.1186/s11658-018-0083-3) contains supplementary material, which is available to authorized users.

CRISPR/CAS9 ablation of individual miRNAs from a miRNA family reveals their individual efficacies for regulating cardiac differentiation

Although it is well understood that genetic mutations, chromosomal abnormalities, and epigenetic miscues can cause congenital birth defects, many defects are still labeled idiopathic, meaning their origin is not yet understood. microRNAs are quickly entering the causal fray of developmental defects. miRNAs use a 7-8 base-pair seed sequence to target a corresponding sequence on one or multiple mRNAs resulting in rapid down-regulation of translation. miRNAs can also control protein 'amounts' in cells. As a result if miRNAs are over or under expressed during development protein homeostasis can be compromised resulting in defects in the development of organ systems. Here, we show that during differentiation of embryonic stem cells, individual miRNAs that reside in the miRNA17 family (composed of 14 miRNAs) do not share the same function even though they have the same seed sequence. The advent of CRISPR/CAS9 technology has not only yielded a true observation of individual miRNA function, it has also reconnected advanced molecular biology approaches to classical cell biology approaches such as gene rescue. We show that miRNA106a and to a lesser extent miR17 and 93 target the cardiac suppressor gene Fog2, which specifically suppress Gata-4 and Coup-TF2. However, when each miRNA is knocked out, we find that their targeting efficacies for Fog2 differ resulting in varying degrees of cardiac differentiation.

Convergence of miR-143 overexpression, oxidative stress and cell death in HCT116 human colon cancer cells

MicroRNAs (miRNAs) regulate a wide variety of biological processes, including tumourigenesis. Altered miRNA expression is associated with deregulation of signalling pathways, which in turn cause abnormal cell growth and de-differentiation, contributing to cancer. miR-143 and miR-145 are anti-tumourigenic and influence the sensitivity of tumour cells to chemotherapy and targeted therapy. Comparative proteomic analysis was performed in HCT116 human colon cancer cells stably transduced with miR-143 or miR-145. Immunoblotting analysis validated the proteomic data in stable and transient miRNA overexpression conditions in human colon cancer cells. We show that approximately 100 proteins are differentially expressed in HCT116 human colon cancer cells stably transduced with miR-143 or miR-145 compared to Empty control cells. Further, Gene Ontology and pathway enrichment analysis indicated that proteins involved in specific cell signalling pathways such as cell death, response to oxidative stress, and protein folding might be modulated by these miRNAs. In particular, antioxidant enzyme superoxide dismutase 1 (SOD1) was downregulated by stable expression of either miR-143 or miR-145. Further, SOD1 gain-of-function experiments rescued cells from miR-143-induced oxidative stress. Moreover, miR-143 overexpression increased oxaliplatin-induced apoptosis associated with reactive oxygen species generation, which was abrogated by genetic and pharmacological inhibition of oxidative stress. Overall, miR-143 might circumvent resistance of colon cancer cells to oxaliplatin via increased oxidative stress in HCT116 human colon cancer cells.

Characterization of Lgr5+ Progenitor Cell Transcriptomes after Neomycin Injury in the Neonatal Mouse Cochlea

Lgr5+ supporting cells (SCs) are enriched hair cell (HC) progenitors in the cochlea. Both in vitro and in vivo studies have shown that HC injury can spontaneously activate Lgr5+ progenitors to regenerate HCs in the neonatal mouse cochlea. Promoting HC regeneration requires the understanding of the mechanism of HC regeneration, and this requires knowledge of the key genes involved in HC injury-induced self-repair responses that promote the proliferation and differentiation of Lgr5+ progenitors. Here, as expected, we found that neomycin-treated Lgr5+ progenitors (NLPs) had significantly greater HC regeneration ability, and greater but not significant proliferation ability compared to untreated Lgr5+ progenitors (ULPs) in response to neomycin exposure. Next, we used RNA-seq analysis to determine the differences in the gene-expression profiles between the transcriptomes of NLPs and ULPs from the neonatal mouse cochlea. We first analyzed the genes that were enriched and differentially expressed in NLPs and ULPs and then analyzed the cell cycle genes, the transcription factors, and the signaling pathway genes that might regulate the proliferation and differentiation of Lgr5+ progenitors. We found 9 cell cycle genes, 88 transcription factors, 8 microRNAs, and 16 cell-signaling pathway genes that were significantly upregulated or downregulated after neomycin injury in NLPs. Lastly, we constructed a protein-protein interaction network to show the interaction and connections of genes that are differentially expressed in NLPs and ULPs. This study has identified the genes that might regulate the proliferation and HC regeneration of Lgr5+ progenitors after neomycin injury, and investigations into the roles and mechanisms of these genes in the cochlea should be performed in the future to identify potential therapeutic targets for HC regeneration.

Interactions between microRNAs and long non-coding RNAs in cardiac development and repair

Non-coding RNAs (ncRNAs) are emerging players in muscle regulation. Based on their length and differences in molecular structure, ncRNAs are subdivided into several categories including small interfering RNAs, stable non-coding RNAs, microRNAs (miRs), long non-coding RNAs (lncRNAs), and circular RNAs. miRs and lncRNAs are able to post-transcriptionally regulate many genes and bring into play several traits simultaneously due to a myriad of different targets. Recent studies have emphasized their importance in cardiac regeneration and repair. As their altered expression affects cardiac function, miRs and lncRNAs could be potential targets for therapeutic intervention. In this context, miR- and lncRNA-based gene therapies are an interesting field for harnessing the complexity of ncRNA-based therapeutic approaches in cardiac diseases. In this review we will focus on lncRNA- and miR-driven regulations of cardiac development and repair. Finally, we will summarize miRs and lncRNAs as promising candidates for the treatment of heart diseases.

Inhibition of Fatty Acid Synthase Reduces Blastocyst Hatching through Regulation of the AKT Pathway in Pigs

Fatty acid synthase (FASN) is an enzyme responsible for the de novo synthesis of long-chain fatty acids. During oncogenesis, FASN plays a role in growth and survival rather than acting within the energy storage pathways. Here, the function of FASN during early embryonic development was studied using its specific inhibitor, C75. We found that the presence of the inhibitor reduced blastocyst hatching. FASN inhibition decreased Cpt1 expression, leading to a reduction in mitochondria numbers and ATP content. This inhibition of FASN resulted in the down-regulation of the AKT pathway, thereby triggering apoptosis through the activation of the p53 pathway. Activation of the apoptotic pathway also leads to increased accumulation of reactive oxygen species and autophagy. In addition, the FASN inhibitor impaired cell proliferation, a parameter of blastocyst quality for outgrowth. The level of OCT4, an important factor in embryonic development, decreased after treatment with the FASN inhibitor. These results show that FASN exerts an effect on early embryonic development by regulating both fatty acid oxidation and the AKT pathway in pigs.

Peroxisome proliferator-activated receptor δ improves porcine blastocyst hatching via the regulation of fatty acid oxidation

Peroxisome proliferator-activated receptor δ (Pparδ) is a nuclear receptor that plays critical roles in lipid metabolism, glucose metabolism, and cell growth and differentiation. Several recent studies have shown that Pparδ promotes blastocyst hatching in vitro. However, the mechanism by which it promotes preimplantation embryonic development in vitro remains unclear. In this study, oocytes and parthenotes were treated with a specific agonist of PPARδ, GW501516. The activation of PPARδ had no effect on oocyte maturation for 1 μM and 10 μM GW501516 compared with the control group. Additionally, the PPARδ agonist did not affect blastocyst formation (77.79 ± 3.59% [10 μM], 79.00 ± 5.53% [50 μM], and 79.64 ± 6.00% [100 μM] vs. 81.69 ± 2.61% [control]). However, the blastocyst hatching rate was significantly greater for parthenotes treated with 10 and 50 μM agonist, and did not differ between those treated with 100 μM agonist and the control group (61.80 ± 3.03% [10 μM], 65.10 ± 5.25% [50 μM], and 38.85 ± 7.45% [100 μM] vs. 41.77 ± 10.88% [0 μM]). Activation of PPARδ also increased blastocyst quality and cell number, as well as ATP production. There were no clear differences in mitochondrial membrane potential, mitochondrion copy number, or glucose consumption between the treatment and control groups. However, PPARδ activation enhanced lipid accumulation via Fabp3 and Fabp5. Fatty acid oxidation also increased in response to treatment with the agonist via the rate-limiting gene Cpt2. Reactive oxygen species were modified and REDOX maintenance-related gene expression increased significantly in GW501516-exposed blastocysts. In addition, the activation of PPARδ resulted in changes in miRNA content. After treatment with the PPARδ agonist, miR-99 increased and miR-32 decreased. These data showed that PPARδ has a positive impact on blastocyst hatching via the regulation of lipid metabolism.

Transfection of arginine decarboxylase gene increases the neuronal differentiation of neural progenitor cells

Growing evidence suggests that the clinical use of neural progenitor cells (NPCs) is hampered by heterogeneity, poor neuronal yield and low survival rate. Recently, we reported that retrovirus-delivered human arginine decarboxylase (hADC) genes improve cell survival against oxidative insult in murine NPCs in vitro. This study investigates whether the induced expression of hADC gene in mNPCs induces any significant change in the cell fate commitment. The evaluation of induced hADC gene function was assessed by knockdown of hADC gene using specific siRNA. The hADC gene delivery triggered higher expression of N-CAM, cell adhesion molecule and MAP-2, neuronal marker. However, the hADC gene knockdown showed downregulation of N-CAM and MAP-2 expression suggesting that hADC gene delivery favors cell fate commitment of mNPCs towards neuronal lineage. Neurite outgrowth was significantly longer in the hADC infected cells. The neurotrophic signal, BDNF aided in the neuronal commitment, differentiation, and maturation of hADC-mNPCs through PI3K and ERK1/2 activation. The induction of neuron-like differentiation is believed to be regulated by the expression of GSK-3β and Wnt/β-catenin signaling pathways. Our findings suggest that hADC gene delivery favors cell fate commitment of mNPCs towards neuronal lineage, bring new advances in the field of neurogenesis and cell therapy.

MicroRNA-145 Regulates Neural Stem Cell Differentiation Through the Sox2-Lin28/let-7 Signaling Pathway

MicroRNAs (miRNAs or miRs) regulate several biological functions, including cell fate determination and differentiation. Although miR-145 has already been described to regulate glioma development, its precise role in neurogenesis has never been addressed. miR-145 represses sex-determining region Y-box 2 (Sox2), a core transcription factor of embryonic stem cells (ESCs), to inhibit pluripotency and self-renewal in human ESCs. In addition, the Sox2-Lin28/let-7 signaling pathway regulates proliferation and neurogenesis of neural precursors. In this study, we aimed to investigate the precise role of miR-145 in neural stem cell (NSC) fate decision, and the possible involvement of the Sox2-Lin28/let-7 signaling pathway in miR-145 regulatory network. Our results show for the first time that miR-145 expression significantly increased after induction of mouse NSC differentiation, remaining elevated throughout this process. Forced miR-145 downregulation decreased neuronal markers, namely βIII-tubulin, NeuN, and MAP2. Interestingly, throughout NSC differentiation, protein levels of Sox2 and Lin28, a well-known suppressor of let-7 biogenesis, decreased. Of note, neuronal differentiation also resulted in let-7a and let-7b upregulation. Transfection of NSCs with anti-miR-145, in turn, increased both Sox2 and Lin28 protein levels, while decreasing both let-7a and let-7b. More importantly, Sox2 and Lin28 silencing partially rescued the impairment of neuronal differentiation induced by miR-145 downregulation. In conclusion, our results demonstrate a novel role for miR-145 during NSC differentiation, where miR-145 modulation of Sox2-Lin28/let-7 network is crucial for neurogenesis progression. Stem Cells 2016;34:1386-1395.

MicroRNA-212 Regulates the Expression of Olfactomedin 1 and C-Terminal Binding Protein 1 in Human Endometrial Epithelial Cells to Enhance Spheroid Attachment In Vitro

Successful embryo implantation requires a synchronized dialogue between a competent blastocyst and the receptive endometrium, which occurs in a limited time period known as the "window of implantation." Recent studies suggested that down-regulation of olfactomedin 1 (OLFM1) in the endometrium and fallopian tube is associated with receptive endometrium and tubal ectopic pregnancy in humans. Interestingly, the human chorionic gonadotropin (hCG) induces miR-212 expression, which modulates OLFM1 and C-terminal binding protein 1 (CTBP1) expressions in mouse granulosa cells. Therefore, we hypothesized that embryo-derived hCG would increase miR-212 expression and down-regulate OLFM1 and CTBP1 expressions to favor embryo attachment onto the female reproductive tract. We found that hCG stimulated the expression of miR-212 and down-regulated OLFM1 but not CTBP1 mRNA in both human endometrial (Ishikawa) and fallopian (OE-E6/E7) epithelial cells. However, hCG suppressed the expression of OLFM1 and CTBP1 proteins in both cell lines. The 3'UTR of both OLFM1 and CTBP1 contained binding sites for miR-212. The miR-212 precursor suppressed luciferase expression, whereas the miR-212 inhibitor stimulated luciferase expression of the wild-type (WT)-OLFM1 and WT-CTBP1 reporter constructs. Furthermore, hCG (25 IU/ml) treatments stimulated trophoblastic (Jeg-3) spheroid (blastocyst surrogate) attachment onto Ishikawa and OE-E6/E7 cells. Transfection of miR-212 precursor increased Jeg-3 spheroid attachment onto Ishikawa cells and decreased OLFM1 and CTBP1 protein expressions, whereas the opposite occurred with miR-212 inhibitor. Taken together, hCG stimulated miR-212, which in turn down-regulated OLFM1 and CTBP1 expression in fallopian and endometrial epithelial cells to favor spheroid attachment.

RhoC is a major target of microRNA-93-5P in epithelial ovarian carcinoma tumorigenesis and progression

Background

An increasing amount of evidence has revealed that microRNAs regulate various biological processes, including cell differentiation, cell proliferation, apoptosis, drug resistance, and fat metabolism. Studies have shown that miR-93’s targetome in cancer has not been fully defined. Moreover, the role of miR-93 in epithelial ovarian carcinoma (EOC) remains largely unknown.

Methods

MIR-93 mRNA expression in normal ovarian tissue, benign tumors, borderline tumors, primary ovarian carcinomas, and metastatic omentum was quantified. The ovarian carcinoma cell lines OVCAR3, SKOV3/DDP, and HO8910-PM were transfected with miR-93-5P, after which cell phenotype and expression of relevant molecules were assayed. Dual-luciferase reporter assay and a xenograft mouse model were used to examine miR-93 and its target gene RHOC (Ras homolog gene family member C).

Results

MIR-93 mRNA expression was significantly lower in ovarian carcinomas and borderline tumors than in normal ovarian tissues (p < 0.05), and was lower in metastatic omentum than in relative primary ovarian carcinomas (p < 0.05). MIR-93 mRNA expression was also negatively associated with differentiation (well vs. poor and moderate) and International Federation of Gynecology and Obstetrics staging (FIGO stage I/II vs. stage III/IV) in ovarian carcinoma (p < 0.05), besides, miR-93 was higher expressed in mucinous adenocarcinoma than the other types (p < 0.05). MiR-93-5P overexpression reduced proliferation (p < 0.05); promoted G₁ or S arrest and apoptosis (p < 0.05); suppressed migration and invasion (p < 0.05); and reduced RhoC, P70S6 kinase, Bcl-xL, matrix metalloproteinase 9 (MMP9) mRNA or protein expression; conversely, it induced P53 and cleaved PARP expression (p < 0.05). Dual-luciferase reporter assay indicated that miR-93 directly targeted RhoC by binding its 3′ untranslated region. MiR-93-5P transfection also suppressed tumor development and RhoC expression (determined by immunohistochemistry) in vivo in the xenograft mouse model (p < 0.05).

Conclusions

This is the first demonstration that miR-93-5P may inhibit EOC tumorigenesis and progression by targeting RhoC. These findings indicate that miR-93-5P is a potential suppressor of ovarian cellular proliferation. The involvement of miR-93-5P–mediated RhoC downregulation in inhibiting EOC aggressiveness may provide extended insight into the molecular mechanisms underlying cancer aggressiveness.