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Objective: This study aimed to investigate the role and underlying mechanisms of microRNA (miRNA)-181b in the inflammatory response in pulpitis., Methods: Quantitative reverse-transcription polymerase chain reaction (qRT-PCR), fluorescence in situ hybridization (FISH), and immunofluorescence techniques were used to determine the miRNA-181b and urokinase-type plasminogen activator (PLAU) expression levels in inflamed human dental pulp tissues (HDPTs) and lipopolysaccharide (LPS)-stimulated human dental pulp cells (hDPCs). The targets of miRNA-181b were identified and confirmed using a bioinformatics analysis, RNA sequencing, and dual-luciferase gene reporter assays. The effect of miRNA-181b or PLAU on proinflammatory cytokine expression in hDPCs was examined using qRT-PCR and western blotting. RNA sequencing was conducted to examine the signaling pathways implicated in miRNA-181b-mediated pulpitis. Western blotting and qRT-PCR were used to determine the miRNA-181b /PLAU/AKT/NF-κB signaling axis in pulpitis. A rat pulpitis model was created to observe the histopathological changes in the dental pulp tissue after the topical application of miRNA-181b agomir., Results: A significant decrease in miRNA-181b and an increase in PLAU were observed in HDPTs compared to the healthy controls, and these two factors showed a negative correlation. MiRNA-181b directly targeted PLAU. The miRNA-181b inhibitor resulted in a significant upregulation of IL-1β, IL-6 and TNF-α, whereas the knockdown of PLAU reversed this proinflammatory effect. Conversely, PLAU overexpression prevented the anti-inflammatory effects of the miRNA-181b mimics. Mechanistically, miRNA-181b inhibited the AKT/NF-κB pathway by targeting PLAU. In vivo application of the miRNA-181b agomir to inflamed pulp tissue alleviated inflammation., Conclusion: MiRNA-181b targets PLAU, negatively regulating pro-inflammatory cytokine expression via the AKT/NF-κB signaling pathway., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background The identification of large-artery stiffness as a major, independent risk factor for cardiovascular disease-associated morbidity and death has focused attention on identifying therapeutic strategies to combat this disorder. Genetic manipulations that delete or inactivate the translin/trax microRNA-degrading enzyme confer protection against aortic stiffness induced by chronic ingestion of high-salt water (4%NaCl in drinking water for 3 weeks) or associated with aging. Therefore, there is heightened interest in identifying interventions capable of inhibiting translin/trax RNase activity, as these may have therapeutic efficacy in large-artery stiffness. Methods and Results Activation of neuronal adenosine A 2A receptors (A 2A Rs) triggers dissociation of trax from its C-terminus. As A 2A Rs are expressed by vascular smooth muscle cells (VSMCs), we investigated whether stimulation of A 2A R on vascular smooth muscle cells promotes the association of translin with trax and, thereby increases translin/trax complex activity. We found that treatment of A7r5 cells with the A 2A R agonist CGS21680 leads to increased association of trax with translin. Furthermore, this treatment decreases levels of pre-microRNA-181b, a target of translin/trax, and those of its downstream product, mature microRNA-181b. To check whether A 2A R activation might contribute to high-salt water-induced aortic stiffening, we assessed the impact of daily treatment with the selective A 2A R antagonist SCH58261 in this paradigm. We found that this treatment blocked aortic stiffening induced by high-salt water. Further, we confirmed that the age-associated decline in aortic pre-microRNA-181b/microRNA-181b levels observed in mice also occurs in humans. Conclusions These findings suggest that further studies are warranted to evaluate whether blockade of A 2A Rs may have therapeutic potential in treating large-artery stiffness.

Exosomes derived from bone marrow mesenchymal stem cells can inhibit neuroinflammation through regulating microglial phenotypes and promoting nerve injury repair. However, the underlying molecular mechanism remains unclear. In this study, we investigated the mechanism by which exosomes derived from bone marrow mesenchymal stem cells inhibit neuroinflammation. Our in vitro co-culture experiments showed that bone marrow mesenchymal stem cells and their exosomes promoted the polarization of activated BV2 microglia to their anti-inflammatory phenotype, inhibited the expression of proinflammatory cytokines, and increased the expression of anti-inflammatory cytokines. Our in vivo experiments showed that tail vein injection of exosomes reduced cell apoptosis in cortical tissue of mouse models of traumatic brain injury, inhibited neuroinflammation, and promoted the transformation of microglia to the anti-inflammatory phenotype. We screened some microRNAs related to neuroinflammation using microRNA sequencing and found that microRNA-181b seemed to be actively involved in the process. Finally, we regulated the expression of miR181b in the brain tissue of mouse models of traumatic brain injury using lentiviral transfection. We found that miR181b overexpression effectively reduced apoptosis and neuroinflamatory response after traumatic brain injury and promoted the transformation of microglia to the anti-inflammatory phenotype. The interleukin 10/STAT3 pathway was activated during this process. These findings suggest that the inhibitory effects of exosomes derived from bone marrow mesenchymal stem cells on neuroinflamation after traumatic brain injury may be realized by the action of miR181b on the interleukin 10/STAT3 pathway., Competing Interests: None

Background and Aims: Chronic vascular endothelial inflammation predisposes to atherosclerosis; however, the cell-autonomous roles for endothelial-expressing microRNAs (miRNAs) are poorly understood in this process. MiR-181b is expressed in several cellular constituents relevant to lesion formation. The aim of this study is to examine the role of genetic deficiency of the miR-181b locus in endothelial cells during atherogenesis., Methods and Results: Using a proprotein convertase subtilisin/kexin type 9 (PCSK9)-induced atherosclerosis mouse model, we demonstrated that endothelial cell (EC)-specific deletion of miR-181a2b2 significantly promoted atherosclerotic lesion formation, cell adhesion molecule expression, and the influx of lesional macrophages in the vessel wall. Yet, endothelium deletion of miR-181a2b2 did not affect body weight, lipid metabolism, anti-inflammatory Ly6C low or the pro-inflammatory Ly6C interm and Ly6C high fractions in circulating peripheral blood mononuclear cells (PBMCs), and pro-inflammatory or anti-inflammatory mediators in both bone marrow (BM) and PBMCs. Mechanistically, bulk RNA-seq and gene set enrichment analysis of ECs enriched from the aortic arch intima, as well as single cell RNA-seq from atherosclerotic lesions, revealed that endothelial miR-181a2b2 serves as a critical regulatory hub in controlling endothelial inflammation, cell adhesion, cell cycle, and immune response during atherosclerosis., Conclusions: Our study establishes that deficiency of a miRNA specifically in the vascular endothelium is sufficient to profoundly impact atherogenesis. Endothelial miR-181a2b2 deficiency regulates multiple key pathways related to endothelial inflammation, cell adhesion, cell cycle, and immune response involved in the development of atherosclerosis., (Copyright © 2022 Elsevier B.V. All rights reserved.)

MicroRNAs (miRNAs) are short endogenous noncoding RNAs regulating protein translation. However, the specific mechanism by which miR-181b influences sepsis via high-mobility group box-1 protein (HMGB1) still remains unknown. Thus, the aim of this study is to investigate the mechanism of miR-181b in regulating inflammatory response in sepsis-induced myocardial injury through targeting high-mobility group box-1 protein (HMGB1). Through cecal ligation and puncture (CLP), the rat model of sepsis was established. Then, the effect of altered expression of miR-181b and HMGB1 on cardiomyocytes was investigated. The positive expression rate of HMGB1, concentration of inflammatory factors, and serum myocardial enzyme of myocardial tissues were determined. Besides, the binding site between miR-181b and HMGB1 was determined by bioinformatics information and dual-luciferase reporter gene assay. The expression of related genes in cells of each group was determined by RT-qPCR and western blot analysis, and the apoptosis rate of transfected cells in each group was determined by TUNEL assay. HMGB1 expression and inflammatory factors were significantly increased in myocardial tissue of rats with sepsis. Cell morphology and the infiltration of inflammatory cells were significantly improved by overexpression of miR-181b. miR-181b directly targeted HMGB1, and downregulation of HMGB1 reduced inflammatory factors and myocardial injury and inhibited cardiomyocyte apoptosis in sepsis. This present study suggests that miR-181b decreased inflammatory factors and reduced myocardial injury in sepsis through downregulation of HMGB1. Thus, a better understanding of this process may aid in the development of novel therapeutic agents in sepsis., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.)

Introduction: Long noncoding RNA small nuclear host gene 1 (SNHG1) was involved in neuroinflammation in microglial BV-2 cells; however, its interaction with microRNA (miR)-181b in lipopolysaccharide (LPS)-induced BV-2 cells remained poor., Methods: BV-2 cells were treated with LPS and then were subjected to observation on morphology and immunofluorescence staining. After transfection, levels of inflammatory cytokines interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) were determined with enzyme-linked immunosorbent assay (ELISA). The potential binding sites between SNHG1 and miR-181b were confirmed using dual-luciferase reporter assay. Quantitative real-time polymerase chain reaction and Western blot were applied for detecting the mRNA and protein expressions of proinflammatory cytokines, ionized calcium-binding adapter molecule 1 (Iba1), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS)., Results: LPS led to the morphological changes and activation of BV-2 cells. The transfection of SNHG1 overexpression vector further promoted LPS-induced SNHG1 upregulation, inflammatory cytokines (IL-1β, IL-6, and TNF-α) generation and Iba-1, COX-2, and iNOS expressions, whereas silencing SNHG1 did the opposite. miR-181b functions as a downstream miRNA of SNHG1. In LPS-treated cells, the inhibition of miR-181b induced by SNHG1 promoted inflammation response and the expressions of Iba-1, COX-2, and iNOS., Conclusion: SNHG1 was involved in LPS-induced microglial activation and inflammation response via targeting miR-181b, providing another evidence of the roles of SNHG1 implicated in neuroinflammation of microglia., (© 2021 S. Karger AG, Basel.)

Nuclear-enriched abundant transcript 1 (NEAT1), a vital long noncoding RNA (lncRNA), exhibits the functions in disparate cancers. Nevertheless, the influences of NEAT1 in congenital heart disease (CHD) remain unreported. The research delves into whether NEAT1 affects H9c2 cells apoptosis and autophagy under the hypoxia condition. Overexpressed NEAT1 vector was transfected into H9c2 cells; then, functions of NEAT1 in cell viability, apoptosis, autophagy, PI3K/AKT/mTOR and JAK1/STAT3 pathways were detected in H9c2 cells under hypoxia condition. Expression of NEAT1 and miR-181b in hypoxia and blood samples from CHD was evaluated. After miR-181b inhibitor transfection, functions of miR-181b repression in the above-mentioned cell behavior and PI3K/AKT/mTOR and JAK1/STAT3 pathways were reassessed. Overexpressed NEAT1 clearly allayed hypoxia-triggered H9c2 cells apoptosis and autophagy. The decreased NEAT1 and miR-181b were showcased in hypoxia and blood samples from CHD; meanwhile, elevated miR-181b evoked by overexpressed NEAT1 was observed in hypoxia-managed H9c2 cells. More importantly, miR-181b inhibition obviously overturned the influences of NEAT1 in hypoxia-affected H9c2 cells apoptosis and autophagy. Besides, overexpressed NEAT1 facilitated PI3K/AKT/mTOR and JAK1/STAT3 activations via enhancing miR-181b. The research exposed that NEAT1 eased hypoxia-triggered H9c2 cells apoptosis and autophagy by expediting PI3K/AKT/mTOR and JAK1/STAT3 pathways via elevating miR-181b.

This study aimed to study the roleof microRNA (miR)-181b and its target TIMP3 in the development of diabetic nephropathy (DMN) via inhibiting the apoptosis of mesangial cells. Real-time polymerase chain reaction (RT-PCR) was adopted to compare the miR-181b expression between subjects with diabetic nephropathy (DN) and normal control. In addition, luciferase assays were utilized to explore the regulatory relationship between TIMP3 and miR-181b. Real-time PCR and densitometry analysis were conducted to measure the levels of TIMP3 mRNA/protein in DMN or in cells treated by miR-181b inhibitors, miR-181b mimics, and TIMP3 siRNA. And the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was adopted to study the effect of miR-181b on cell survival and apoptosis. miR-181b expression was much higher in the DN group, and the results of computational analysis identified TIMP3 as a miR-181b target. The luciferase activity of cells transfected with wild-type TIMP3 and mutant2 TIMP3 was significantly reduced, whereas the luciferase activity of cells transfected with mutant1 TIMP3 was evidently higher. Furthermore, a negative regulatory relationship was established between TIMP3 and miR-181b expression with a correlation efficient of -0.5351. The levels of TIMP3 mRNA/protein expression were apparently increased in the DN group. In addition, the treatment of cells with miR-181b mimics and TIMP3 siRNA remarkably lowered the levels of TIMP3 mRNA/protein, whereas the transfection of cells with miR-181b inhibitors notably elevated the expression of TIMP3 mRNA/protein. miR-181b promoted the survival of cells and inhibited their apoptosis. The miR-181b expression was related to the development of DMN and could be used as a prognosis biomarker of DMN in the patients with DM., (© 2019 Wiley Periodicals, Inc.)

Background: The aim of the study was to measure the expression of microRNA (miR)-181b in patients with lung cancer, investigate its biological function and elucidate the underlying mechanisms associated with the development of lung cancer., Methods: miR-181b expression in tissues was measured via RT-qPCR. After A549 cells were transfected with miR-181b mimic or si-Sox6, the proliferation, migration and cell cycle distribution of A549 were evaluated using cell counting kit-8 assay, transwell assay and flow cytometry. The levels of cell cycle-related proteins and Sox6 were analyzed by western blotting. Gene targets of miR-181b were predicted via bioinformatics analysis and verified using a dual-luciferase reporter gene assay., Results: Expression of miR-181b was significantly downregulated in lung cancer tissues (P < 0.05), and was inversely correlated with the degree of cell differentiation and clinical stages of lung cancer (both P < 0.05). Additionally, the expression of miR-181b was significantly lower in adenocarcinoma compared with squamous cell carcinoma in the lungs (P < 0.05). Overexpression of miR-181b significantly decreased the protein level of Sox6 and significantly suppressed the cell proliferation and metastasis (both P < 0.05); this effect was also observed in A549 cells transfected with si-Sox6. The luciferase activity of a Sox6 3'-untranslated region-based reporter construct was significantly lower when transfected with miR-181b (P < 0.05), which suggests that Sox6 is a direct target of miR-181b., Conclusion: The results of the present study suggest that miR-181b may function as a tumor inhibitor in the development of lung cancer via targeting Sox6 to decrease the proliferation and metastasis of lung cancer cells., (Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Background: Lung cancer stem cells have the ability to self-renew and are resistant to conventional chemotherapy. MicroRNAs (miRNAs) regulate and control the expression and function of many target genes; therefore, miRNA disorders are involved in the pathogenesis of human diseases, such as cancer. However, the effects of miRNA dysregulation on tumour stemness and drug resistance have not been fully elucidated. miR-181b has been reported to be a tumour suppressor miRNA and is associated with drug-resistant non-small cell lung cancer., Methods: Cancer stem cell (CSC)-like properties were tested by a cell proliferation assay and flow cytometry; miR-181b expression was measured by real-time PCR; and Notch2 and related proteins were detected by Western blotting and immunohistochemistry. A mouse xenograft model was also established., Results: In this study, we found that ectopic miR-181b expression suppressed cancer stem cell properties and enhanced sensitivity to cisplatin (DDP) treatment by directly targeting Notch2. miR-181b could inactivate the Notch2/Hes1 signalling pathway. In addition, tumours from nude mice treated with miR-181b were significantly smaller than tumours from mice treated with control agomir. Decreased miR-181b expression and increased Notch2 expression were observed to have a significant relationship with overall survival (OS) and CSC-like properties in non-small cell lung cancer (NSCLC) patients., Conclusions: This study elucidates an important role of miR-181b in the regulation of CSC-like properties, suggesting a potential therapeutic target for overcoming drug resistance in NSCLC.

This study aimed to investigate the relationship between the expression of microRNA (miR)-181b, protein inhibitor of activated STAT3 (PIAS3) and STAT3, and to examine the function of the miR-181b/PIAS3/STAT3 axis on the Warburg effect and xenograft tumour growth of colon cancer. Moreover, a positive feedback loop between miR-181b and STAT3 that regulated the Warburg effect in colon cancer was explored. A luciferase reporter assay was used to identify whether PIAS3 was a direct target of miR-181b. The gain-of-function and loss-of-function experiments were performed on HCT 116 cells to investigate the effect of miR-181b/PIAS3/STAT3 on the Warburg effect and xenograft tumour growth of colon cancer, as determined by commercial kits and xenograft experiments. The relationship between the expression of miR-181b, PIAS3 and STAT3 in HCT 116 and HT-29 cells was determined using RT-qPCR and Western blot. We found miR-181b was a direct regulator of PIAS3. miR-181b promoted the Warburg effect and the growth of colon cancer xenografts; however, these effects could be reversed by PIAS3. miR-181b expression interacted with STAT3 phosphorylation in a positive feedback loop in colon cancer cells via regulating PIAS3 expression. In conclusion, this study for the first time demonstrated that miR-181b contributed to the Warburg effect and xenograft tumour growth of colon cancer by targeting PIAS3. Moreover, a positive feedback loop between miR-181b and STAT3 that regulated the Warburg effect in colon cancer was also demonstrated. This study suggested miR-181b/PIAS3/STAT3 axis as a novel target for colon cancer treatment., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Adipose-derived stem cells (ADSCs) have been demonstrated to promote cerebral vascular remodeling processes after stroke. However, the exact molecular mechanism by which ADSCs exert protective roles in ischemic stroke is still poorly understood. In this study, we identified the role of exosomal microRNA-181b-5p (181b-Exos) in regulating post-stroke angiogenesis. The results of migration assay and capillary network formation assay showed that exosomes secreted by ADSCs (ADSCs-Exos) promoted the mobility and angiogenesis of brain microvascular endothelial cells (BMECs) after oxygen-glucose deprivation (OGD). Quantitative real-time polymerase chain reaction (qRT-PCR) showed that microRNA-212-5p (miR-212-5p) and miR-181b-5p were upregulated in BMECs subjected to the brain extract of the middle cerebral artery occlusion rats. The migration distance and tube length were increased in BMECs cultured with 181b-Exos. Furthermore, we identified that transient receptor potential melastatin 7 (TRPM7) was a direct target of miR-181b-5p. TRPM7 mRNA and protein levels were declined in BMECs cultured with 181b-Exos, but not in BMECs cultured with 212-Exos. Overexpression of TRPM7 reversed the effects of 181b-Exos on migration and tube formation of BMECs. In addition, 181b-Exos upregulated the protein expression of hypoxia-inducible factor 1α and vascular endothelial cell growth factor, and downregulated the protein expression of tissue inhibitor of metalloproteinase 3. The regulatory effect of 181b-Exos was attenuated by overexpressing TRPM7. Altogether, ADSCs-Exos promote the angiogenesis of BMECs after OGD via miR-181b-5p/TRPM7 axis, suggesting that ADSCs-Exos may represent a novel therapeutic approach for stroke recovery.

Cumulative evidence has indicated that celastrol may suppress cancer growth; however, the underlying mechanism requires further investigation. In the present study, A549 cells were treated with various concentrations of celastrol. Lung cancer cell proliferation was evaluated using an MTT assay and observed under a microscope. Cell apoptosis was detected by Annexin V fluorescein isothiocyanate/propidium iodide double-labeled flow cytometry. The results demonstrated that celastrol suppressed proliferation and induced apoptosis in a dose-independent manner. Celastrol may also decrease the phosphorylation levels of signal transducer and activator of transcription 3 (STAT3) and the B cell lymphoma-2 (Bcl-2)/Bcl-2 associated C protein (Bax) ratio. As microRNA (miR-24 and miR-181b) were predicated to target STAT3, STAT3 activation was inhibited in miR-24-or miR-181b-treated A549 cells compared with the control treatment. The ratio of Bcl-2/Bax was further reduced in miR-24 or miR-181b-treated A549 cells. The results were further confirmed by detecting in another lung adenocarcinoma cell line, LTEP-a-2. In summary, the results of the present study demonstrated that celastrol treatment suppressed the proliferation and induced apoptosis by regulating the expression levels of miR-24 and miR-181b.

Purpose: Breast cancer is the most common invasive type of cancer among women. Role of different microRNAs (miRNAs) and poly(ADP-ribose) polymerases (PARPs) in breast cancer has been well established. This study aimed to explore the effects of miR-891b on sensitizing breast cancer cells to alkylating chemotherapeutic drugs through PARPs., Methods: The expression of miR-891b and PARP1 in human breast cancer cells HCC1806 was overexpressed by transfection with their mimics or expressing vector. Then, the transfected cells were exposed to 40 µM N-methyl-N-nitro-N-nitrosoguanidine (MNNG) for 1 h. The correlation between miR-891b and PARP1 was detected by RT-qPCR, western blot, and dual-luciferase reporter assay. Besides, MTT assay and Annexin V assay were done to measure cell proliferation and apoptosis, respectively., Results: PARP1 was a target of miR-891b, and it was negatively regulated by miR-891b. MiR-891b increased the sensitivity of the HCC1806 cells to the cytotoxic effects of MNNG through suppressing cell proliferation and increasing the percentage of apoptotic cells. Restoration of PARP1 activity in the HCC1806 cells led to loss of miR-891b mediated sensitivity of the HCC1806 cells to MNNG., Conclusion: MiR-891b increases the sensitivity of the breast cancer cells (HCC1806) to the cytotoxic effects of the chemotherapeutic agent MNNG by suppressing the expression of PARP1.

Our study aims to explore the role of microRNA-181b (miR-181b) and TLR in the regulation of cell proliferation of human epidermal keratinocytes (HEKs) in psoriasis. Twenty-eight patients diagnosed with psoriasis vulgaris were selected as a case group with their lesional and non-lesional skin tissues collected. A control group consisted of 20 patients who underwent plastic surgery with their healthy skin tissues collected. Real-time quantitative fluorescence polymerase chain reaction (RT-qPCR), in situ hybridization and immunohistochemistry were used to detect the expressions of miR-181b and TLR4 in HEKs of healthy skin, psoriatic lesional skin and non-lesional skin respectively. The 3' untranslated region (3'UTR) of TLR4 combined with miR-181b was verified by a dual-luciferase reporter assay. Western blotting and bromodeoxyuridine were applied for corresponding detection of TLR4 expression and cell mitosis. The expression of miR-181b in HEKs of psoriatic lesional skin was less than healthy skin and psoriatic non-lesional skin. In psoriatic lesional and non-lesional skin, TLR4-positive cell rates and the number of positive cells per square millimetre were higher than healthy skin. The dual-luciferase reporter assay verified that miR-181b targets TLR4. HEKs transfected with miR-181b mimics had decreased expression of TLR4, along with the decrease of mitotic indexes and Brdu labelling indexes. However, HEKs transfected with miR-181b inhibitors showed increased TLR4 expression, mitotic indexes and Brdu labelling indexes. HEKs transfected with both miR-181b inhibitors and siTLR4 had decreased mitotic indexes and Brdu labelling indexes. These results indicate that miR-181b can negatively regulate the proliferation of HEKs in psoriasis by targeting TLR4., (© 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

The expression of microRNA-181b (miR-181b) has been investigated in various human cancers. However, the expression and functions of miR-181b in non-small cell lung cancer (NSCLC) are yet to be studied. In the present study, miR-181b expression in NSCLC tissues and cell lines was analyzed by quantitative polymerase chain reaction, and was shown to be recurrently downregulated. Following transfection of the H23 and H522 NSCLC cells lines with miR-181b, cell migration and cell invasion assays were performed to evaluate the effect of miR-181b overexpression on the cell motility. It was demonstrated that overexpression of miR-181b inhibited the migration and invasion of NSCLC cells. Subsequently, bioinformatics analysis, western blotting and luciferase reporter assays were conducted to investigate the mechanism underlying the miR-181b-mediated inhibition of NSCLC cell motility. It was found that miR-181b directly targeted high-mobility group box-1 (HMGB1) in NSCLC cells. These results reveal a novel therapeutic target, the miR-181b/HMGB1 axis, in NSCLC. Treatment approaches targeting this axis will be beneficial to prevent NSCLC from becoming invasive.

Cancer cells usually utilize glucose as a carbon source for aerobic glycolysis, which is named as ``Warburg effect''. Recent studies have shown that MicroRNAs (miRNAs), a class of short and non-coding RNAs, play a role in the regulation of metabolic reprograming in cancer cells. In the present study, we report that miR-181b negatively regulates glycolysis in gastric cancer cells. Over-expression of miR-181b mimics reduces the glucose uptake and lactate production, while increasing the cellular ATP levels in NCI-N87 and MGC80-3 cells. At the molecular level, miR-181b directly inhibits the expression level of hexokinase 2 (HK2), a key enzyme that catalyzes the first step of glycolysis, through targeting its 3'-untranslated region. In addition, miR-181b represses cell proliferation and migration and is dramatically down-regulated in human gastric cancers. Therefore, our data disclose a novel function of miR-181b in reprogramming the metabolic process in gastric cancer.

Acute lung injury (ALI) is characterized by severe lung edema and an increase in the inflammatory reaction. Considerable evidence has indicated that microRNAs (miRNAs or miRs) are involved in various human diseases; however, the expression profile and function of miRNAs in ALI have been rarely reported. The present study used miRNA microarray and reverse transcription-quantitative polymerase chain reaction to demonstrate that miR-181b is the one of the most significantly upregulated miRNA after lipopolysaccharide (LPS) stimulation in human bronchial epithelial cells, BEAS-2B. To elaborate the role of miR-181b in ALI, an assay was performed to investigate the overexpression of miR-181b in BEAS-2B cells, and the expression of inflammatory factors was then analyzed. The overexpression of miR-181b resulted in the induction of an increment in interleukin (IL)-6 levels. p65 was identified to be a primary component of NF-κB, since it was upregulated in the miR-181b overexpression in the BEAS-2B cells, while pyrrolidine dithiocarbamate, a specific inhibitor of NF-κB, was found to be able to abrogate the upregulation of the expression of p65. In conclusion, the findings of the present study suggested that miR-181b may be involved in the process of LPS-induced inflammation in BEAS-2B cells by activating the NF-κB signaling pathway, which implies that it may serve as a potential therapeutic target for ALI.

The aim of this study was to explore the microRNA (miR)-181b expression in myocardial hypertrophy and to investigate its association with cGMP-dependent protein kinase type I (PKG 1) in an in vitro model. The miR-181b level in the peripheral blood was determined in patients with myocardial hypertrophy, and an in vitro model was established via phenylephrine (PE) treatment. Reverse transcription-quantitative polymerase chain reaction analysis and western blotting were performed to detect the expression levels of miR-181b, PKG 1 and hypertrophy-related genes. The results revealed that the expression of miR-181b was elevated in the peripheral blood of patients with myocardial hypertrophy, and this may have contributed to the pathology and progression of the disease. When the primary myocardial cells were treated with PE, microscopic observation and flow cytometry revealed significant hypertrophy. Furthermore, upregulation of myocardial hypertrophy-related genes, including β-myosin heavy chain, α-sarcomeric actinin and atrial natriuretic peptide, was observed. The miR-181b expression level in the PE-treated cells was elevated, while the mRNA and protein expression levels of PKG 1 were decreased, indicating a negative correlation between miR-181b and PKG 1 in myocardial hypertrophy. In addition, when the PE-treated primary myocardial cells were transfected with miR-181b inhibitor, the reduced PKG 1 expression was restored and the myocardial hypertrophy alleviated, as indicated by the reduced cellular sizes and decreased expression levels of the myocardial hypertrophy-related genes. In conclusion, miR-181b expression has been shown to be upregulated in myocardial hypertrophy, and this may play a role in the pathogenesis of the disease by regulating the expression of PKG 1. The present findings suggest that miR-181b is a promising molecular indicator for the clinical diagnosis and treatment of cardiac hypertrophy.

The aim of the present study was to explore the association between the expression of microRNA (miRNA)-181b and plasminogen activator inhibitor-1 (PAI-1) in the placental tissue of pregnant females with a hypertensive disorder complicating pregnancy (HDCP). Placental tissue samples were obtained from 48 patients with HDCP and 40 females with a normal pregnancy. The levels of miRNA-181b and PAI-1 mRNA were determined by the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression of PAI-1 protein was analyzed by western blotting. Vascular smooth muscle cells (VSMCs) were transfected with the pEGP-miRNA-181b plasmid using Lipofectamine ® 2000. Transfection efficiency was confirmed by immunohistochemical analysis. The levels of miRNA-181b in the placental tissue of patients with HDCP were lower than those in the control group, whereas the levels of PAI-1 mRNA in the placental tissue of patients with HDCP were higher than those in the control group. The expression of the PAI-1 protein in the HDCP group was higher than that in the control group. Following transfection of VSMCs with plasmid pGCMV/EGFP/miRNA-181b, the levels of PAI-1 mRNA were reduced while the levels of miRNA-181 were upregulated. Furthermore, the expression levels of PAI-1 protein were lower than those in the control group. The levels of miRNA-181b and PAI-1 mRNA were strongly associated with HDCP. Thus, miRNA-181b may play an important role in the regulation of PAI-1. PAI-1 and miRNA-181b may be novel biomarkers to be used in HDCP therapy.

MicroRNAs are a class of small, endogenous, non-coding RNAs that function as post-transcriptional regulators. In this study, we found that miR-181b promoted cell proliferation and inhibited cell apoptosis in cervical cancer cells. And we validated a new miR-181b target gene, adenylyl cyclase 9 (AC9). miR-181b restricted cAMP production by post-transcriptionally downregulating AC9 expression. Phenotypic experiments indicated that miR-181b and AC9 exerted opposite effects on cell proliferation and apoptosis., (Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

The aim of this study was to investigate the clinical significance of microRNA-181b (miR-181b) expression in non-small cell lung cancer (NSCLC). MiR-181b expression in 126 pairs of surgically removed NSCLC tissues and their corresponding normal lung tissues was measured by real-time quantitative RT-PCR assay. Additionally, the correlation of miR-181b expression with clinicopathological factors or prognosis of patients was analyzed. At first, miR-181b expression was significantly down-regulated in NSCLC tissues as compared with their normal counterparts (P<0.001). Then, the low miR-181b expression was found to be closely correlated with larger tumor size (P=0.02), higher p-TNM stage (P=0.008) and positive lymph node metastasis (P=0.03) of NSCLC patients. After that, survival analysis found that the overall survival (P=0.001) and disease-free survival (P=0.008) of NSCLC patients with low miR-181b expression were both significantly poorer compared to those patients with high miR-181b expression. Finally, both univariate and multivariate analyses demonstrated that low miR-181b expression may be a poor prognostic marker of NSCLC patients. This is the first study to indicate that down-regulation of miR-181b may be correlated with aggressive disease progression and poor prognosis of NSCLC patients, suggesting that miR-181b might be involved in lung carcinogenesis and become a potential prognostic marker for NSCLC., (Copyright © 2013 Elsevier GmbH. All rights reserved.)