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Introduction: Neuroinflammation contributes to secondary injury after traumatic brain injury (TBI), which has been mainly mediated by the microglia. MiR-124 was reported to play an important role in the polarization of microglia by targeting TLR4 signaling pathway. However, the role and mechanism of miR-124 in neuroinflammation mediated by microglia after TBI is unclear. To clarify this, we performed this research. Methods: The expression of miR-124 was first measured by RT-PCR in the injured brain at 1/3/7 days post-TBI. Then, miR-124 mimics or inhibitors administration was used to interfere the expression of miR-124 at 24 h post-TBI. Subsequently, the microglia polarization markers were detected by RT-PCR, the expression of inflammatory cytokines was detected by ELISA, the expression of TLR4/MyD88/IRAK1/TRAF6/NF-κB was measured by WB, and the neurological deficit was evaluated by NSS and MWM test. At last, in vitro experiments were performed to explore the exact target molecule of miR-124 on TLR4 signaling pathway. Results: Animal research indicated that the expression of miR-124 was downregulated after TBI. Upregulation of miR-124 promoted the M2 polarization of microglia and inhibited the activity of TLR4 pathway, as well as reduced neuroinflammation and neurological deficit after TBI. In vitro experiments indicated that miR-124 promoted the M2 polarization of microglia and reduced neuroinflammation by inhibiting TRAF6. Conclusion: This study demonstrated that upregulation of miR-124 promoted the M2 polarization of microglia and reduced neuroinflammation after TBI by inhibiting TRAF6. [ABSTRACT FROM AUTHOR]

Background/Aims: MicroRNAs play an important role in regulating myocardial infarction (MI)-induced cardiac injury. MicroRNA-124 (miR-124) plays a vital role in regulating cellular proliferation, differentiation and apoptosis. Although the alteration of miR-124 was confirmed in peripheral blood of MI patients, little is known regarding the biological functions of miR-124 in cardiomyocytes. This study was designed to explore the role of miR-124 in MI and its underlying mechanisms. Methods: Real-time PCR was used to quantify the microRNAs levels. TUNEL and Flow cytometry were performed to measure cell apoptosis. Western blot analysis was employed to detect expression of Bcl-2, Bax, Caspase-3 and STAT3 proteins. Results: We revealed that miR-124 was significantly up-regulated in a mice model of MI and in neonatal rat ventricular myocytes (NRVMs) with H2O2 treatment. H2O2 treatment induced cardiomyocyte injury with reduced cell viability and enhanced apoptotic cell death, whereas silencing expression of miR-124 by AMO-124 (antisense inhibitor oligodeoxyribonucleotides) alleviated these deleterious changes. AMO-124 decreased the expression of Bax and cleaved-caspase-3 and upregulated the expression of Bcl-2 in H2O2-treated NRVMs. Besides, AMO-124 improved mitochondrial dysfunction of NRVMs induced by H2O2 treatment. Moreover, antagomir-124 markedly decreased the infarct area and apoptotic cardiomyocytes and improved cardiac function in MI mice. Furthermore, we identified STAT3 as a direct target of miR-124, and downregulation of miR-124 ameliorated the diminished levels of STAT3 and p-STAT3 (Tyr705) in response to H2O2 or MI. STAT3 inhibitor, stattic, was shown to attenuate the elevation of p-STAT3 in NRVMs with AMO-124 transfection. Inhibiting of STAT3 activity by stattic abrogated protective effects of AMO-124 on H2O2-induced cardiomyocytes apoptosis. Conclusion: Taken together, our data demonstrate that downregulation of miR-124 inhibits MI-induced apoptosis through upregulating STAT3, which suggests the therapeutic potential of miR-124 for myocardial infarction. [ABSTRACT FROM AUTHOR]

Background/Aims: Doxorubicin (DOX) is a widely used chemotherapeutic agent for colorectal cancer (CRC). However, the acquirement of DOX resistance limits its clinical application for cancer therapy. Mounting evidence has suggested that aberrantly expressed lncRNAs contribute to drug resistance of various tumors. Our study aimed to explore the role and molecular mechanisms of lncRNA X-inactive specific transcript (XIST) in chemoresistance of CRC to DOX. Methods: The expressions of XIST, miR-124, serum and glucocorticoid-inducible kinase 1 (SGK1) mRNA in DOX-resistant CRC tissues and cells were detected by qRT-PCR or western blot analysis. DOX sensitivity was assessed by detecting IC50 value of DOX, the protein levels of P-glycoprotein (P-gp) and glutathione S-transferase-π (GST-π) and apoptosis. The interactions between XIST, miR-124 and SGK1 were confirmed by luciferase reporter assay, qRT-PCR and western blot. Xenograft tumor assay was used to verify the role of XIST in DOX resistance in CRC in vivo. Results: XIST expression was upregulated and miR-124 expression was downregulated in DOX-resistant CRC tissues and cells. Knockdown of XIST inhibited DOX resistance of CRC cells, as evidenced by the reduced IC50 value of DOX, decreased P-gp and GST-π levels and enhanced apoptosis in XIST-silenced DOX-resistant CRC cells. Additionally, XIST positively regulated SGK1 expression by interacting with miR-124 in DOX-resistant CRC cells. miR-124 suppression strikingly reversed XIST-knockdown-mediated repression on DOX resistance in DOX-resistant CRC cells. Moreover, SGK1-depletion-elicited decrease of DOX resistance was greatly restored by XIST overexpression or miR-124 inhibition in DOX-resistant CRC cells. Furthermore, XIST knockdown enhanced the anti-tumor effect of DOX in CRC in vivo. Conclusion: XIST exerted regulatory function in resistance of DOX possibly through miR-124/SGK1 axis, shedding new light on developing promising therapeutic strategy to overcome chemoresistance in CRC patients. [ABSTRACT FROM AUTHOR]

Background/Aims: HULC is a multifunctional lncRNA that has pro-angiogenic function in various cancers. The present study was designed to see the role of lncRNA HULC in normal endothelial cells angiogenesis. Methods: Cell viability, apoptosis, migration, tube formation and expression levels of angiogenesis-related proteins were respectively assessed in human microvascular endothelial HMEC-1 cells after lncRNA HULC was silenced by shRNA transfection. Cross-regulation between lncRNA HULC and miR-124, and between miR-124 and MCL-1 were detected by qRT-PCR, sequence analysis, and luciferase reporter assay. Results: Silence of lncRNA HULC significantly reduced viability, migration, tube formation and protein levels of VEGF, VEGFR2, CD144 and eNOS in HMEC-1 cells. Meanwhile, silence of lncRNA HULC induced apoptosis in HMEC-1 cells, as Bcl-2 was down-regulated, Bax was up-regulated, and caspase-3 and -9 were cleaved. miR-124 expression was negatively regulated by lncRNA HULC, and HULC worked as a molecular sponge for miR-124, in having miR-124 exhausted. Besides, MCL-1 was a target gene of miR-124. Rescue assay results showed that the effects of lncRNA HULC silence on HMEC-1 cells growth, migration and angiogenesis were abolished by miR-124 suppression. Similarly, the effects of miR-124 on HMEC-1 cells were abolished by MCL-1 overexpression. Furthermore, MCL-1 activated PI3K/AKT and JAK/STAT signaling pathways. Conclusion: These findings suggest a pro-angiogenic role of lncRNA HULC in endothelial cells. The pro-angiogenic actions of lncRNA HULC may be through sponging miR-124, preventing MCL-1 from degradation by miR-124. [ABSTRACT FROM AUTHOR]

Background/Aims: Retinal Müller cells could be induced to differentiate into retinal ganglion cells (RGCs), but RGCs derived from Müller cells have defects in axon growth, leading to a defect in signal conduction. In this study we aimed to explore the role of miR-124 in axon growth of RGCs derived from Müller cells. Methods: Müller cells were isolated from rat retina and induced to dedifferentiate into retinal stem cells. The stem cells were infected by PGCFU- Atoh7-GFP lentivirus and then transfected with miR-124 or anti-miR-124, and the length of axon was compared. Furthermore, the cells were injected into the eyes of rat chronic ocular hypertension glaucoma model and axon growth in vivo was examined. The targeting of CoREST by miR-124 was detected by luciferase assay. Results: In retinal stem cells, the length of axon was 1,792±64.54 µm in miR-124 group, 509±21.35 μm in control group, and only 87.9±9.24 μm in anti-miR-124 group. In rat model, miR-124 promoted axon growth of RGCs differentiated from retinal stem cells. Furthermore, we found that miR-124 negatively regulated CoREST via directly targeting the binding site in CoREST 3' UTR. Conclusions: We provide the first evidence that miR-124 regulates axon growth of RGCs derived from Müller cells, and miR-124 has translational potential for gene therapy of glaucoma. [ABSTRACT FROM AUTHOR]

Background/Aims: Retinal Müller cells could be induced to differentiate into retinal ganglion cells (RGCs), but RGCs derived from Müller cells have defects in axon growth, leading to a defect in signal conduction. In this study we aimed to explore the role of miR-124 in axon growth of RGCs derived from Müller cells. Methods: Müller cells were isolated from rat retina and induced to dedifferentiate into retinal stem cells. The stem cells were infected by PGC-FU-Atoh7-GFP lentivirus and then transfected with miR-124 or anti-miR-124, and the length of axon was compared. Furthermore, the cells were injected into the eyes of rat chronic ocular hypertension glaucoma model and axon growth in vivo was examined. The targeting of CoREST by miR-124 was detected by luciferase assay. Results: In retinal stem cells, the length of axon was 1,792±64.54 µm in miR-124 group, 509±21.35 µm in control group, and only 87.9±9.24 µm in anti-miR-124 group. In rat model, miR-124 promoted axon growth of RGCs differentiated from retinal stem cells. Furthermore, we found that miR-124 negatively regulated CoREST via directly targeting the binding site in CoREST 3′ UTR. Conclusions: We provide the first evidence that miR-124 regulates axon growth of RGCs derived from Müller cells, and miR-124 has translational potential for gene therapy of glaucoma. [ABSTRACT FROM AUTHOR]

Background/Aims: A growing body of evidence indicates that the abnormal expression of microRNAs (miRNAs) play an important role in sensitizing the cellular response to ionizing radiation (IR). The aim of this study was to investigate whether the expression of miR-124 correlated with radiosensitivity in the context of non-small-cell lung carcinoma (NSCLC). Methods: Quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to quantify miR-124 expression in NSCLC tissues and cell lines. The role of miR-124 in NSCLC proliferation and radiosensitivity was analyzed using CCK-8 and flow cytometry apoptosis assays. Luciferase activity assays, RT-PCR, and Western blot assays were performed to confirm the target gene of miR-124. Results: In this study, we found that miR-124 was downregulated both in clinical NSCLC samples and in cell lines. miR-124 inhibited the proliferation of NSCLC cells and enhanced the apoptosis of NSCLC cells exposed to ionizing radiation. We identified signal transducer and activator of transcription 3 (STAT3) as a direct target of miR-124 by using target prediction algorithms and luciferase assays. Overexpression of STAT3 in A549 cell lines restored the enhanced radiosensitivity induced by miR-124. Conclusion: Taking these observations into consideration, we illustrated that miR-124 is a potential target for enhancing the radiosensitivity of NSCLC cells by targeting STAT3. [ABSTRACT FROM AUTHOR]

Background/Aims: With the aging population increases, senile osteoporosis has become a global public health problem. Previous evidence has shown that miR-124 has important effects on the occurrence and development of osteoporosis. However, the role of miR-124 in the process of osteoclastogenesis is still obscure. Methods: First of all, we measured the expression level of miR-124 in bone marrow monocytes (BMMs) of osteoporotic mice (ovariectomized mice: OVX). Next, we evaluated the alteration of miR-124 during osteoclast differentiation of BMMs. Then, BMMs were transfected with miR-124 mimics or inhibitors to explore the influences of miR-124 on osteoclast differentiation of BMMs in vitro. Furthermore, bioinformatics analysis and luciferase reporter assay were performed for prediction and identification of the target of miR-124. Results: BMMs from OVX mice exhibited lower expression of miR-124 compared with Sham mice. Additionally, miR-124 was down-regulated when BMMs differentiated into osteoclasts. In addition, inhibition of miR-124 promoted BMMs differentiated into osteoclasts in vitro, whereas overexpression of miR-124 attenuated this procedure, demonstrated by increased expression of osteoclast specific genes and TRAP staining. Furthermore, Rab27a was confirmed to be the direct target of miR-124 by bioinformatics, Western blot and luciferase reporter assay analysis. Conclusion: Our findings revealed that miR-124 has an important role in osteoclastogenesis via targeting Rab27a. Thus, targeting miR-124 promises a therapeutic potential in the treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

Background/Aim: Women with advanced ovarian carcinoma are less likely to receive platinum-based chemotherapy and surgery due to a greater risk of cytotoxicity and poorer outcomes. We attempted to improve a promising therapy against ovarian cancer by using a combination of dihydroartemisinin (DHA) and curcumin (Cur). Methods: Human ovarian cancer SKOV3 cells were treated with DHA, Cur alone, or a combination of both. The viability of SKOV3 cells was measured by Cell Counting Kit-8 (CCK-8) and a colony formation assay. The cell cycle and apoptosis of SKOV3 cells were monitored by flow cytometry. The mRNA and protein expression levels of target genes were respectively examined by qRT-PCR and western blot. The biological effects of miR-124 on midkine (MK) were verified by a luciferase activity analysis. Results: Combined treatment of DHA and Cur synergistically decreased cell viability, arrested cell cycle, and promoted apoptosis in SKOV3 cells. Moreover, it significantly attenuated the expression of oncogene MK and synergistically upregulated the expression of miR-124. Furthermore, miR-124 was verified to bind directly to the 3'-untranslated region of MK mRNA, resulting in mRNA degradation and reduced MK protein levels. The combination of DHA with Cur significantly inhibited tumor growth in xenograft nude mice without obvious toxicity. Conclusion: Co-treatment with DHA and Cur exhibited a synergistic anti-tumor effect on SKOV3 cells both in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Backgrounds/Aims: Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is involved in the progression of several tumors. The interaction between lncRNA and miRNA or miRNA's target genes is reported to play crucial roles in malignancy. In addition, Androgen receptor (AR) is considered to be involved in bladder cancer progression. In this study, we investigated the role of XIST in human bladder cancer and its interaction with miR-124 and AR. Methods: XIST and AR expression was detected in bladder tumor samples and cell lines. Effects of XIST and AR on bladder cancer cells growth, invasion and migration were analyzed. Bioinformatic analysis and luciferase assays were used to identify the interaction among XIST, AR and miR-124. The correlations of miR-124 with XIST and AR in bladder cancer samples were statistically analyzed. Results: XIST and AR were upregulated in bladder cancer tissues and positively correlated. Higher XIST and AR expression were related to poorer TNM stage of bladder cancer. XIST knockdown reduced bladder cancer cell's proliferation, invasion and migration. While this inhibitory effect could be partially restored by AR overexpression. XIST inhibited miR-124 expression by directly targeting. Moreover, miR-124 could bind to the 3'UTR of AR to regulate its expression. MiR-124 inhibition partially restored the XIST knockdown-induced reduction of AR, c-myc, p27, MMP13 and MMP9 expression. In bladder cancer tissues, miR-124 level was inversely correlated with the expression of XIST and AR, respectively. Conclusion: These findings indicated that XIST might be an oncogenic lncRNA that promoted the bladder cancer growth, invasion and migration via miR-124 dependent AR regulation. [ABSTRACT FROM AUTHOR]

Background/Aims: MiR-124 inhibits neoplastic transformation, cell proliferation, and metastasis and downregulates Rho-associated protein kinase (ROCK1) in Colorectal Cancer (CRC). The aim of this study was to further investigate the roles and interactions of ROCK1 and miR-124 and the effects of knockdown of ROCK1and MiR-124 in human Colorectal Cancer (CRC). Methods: Three Colorectal cancer cell lines (HCT116, HT29 and SW620) and one Human Colonic Mucosa Epithelial cell line (NCM460) were studied. The protein expression of ROCK1 was examined by Western-blot and qRT-PCR were performed to examine the expression levels of ROCK1 mRNA and miR-124. Furthermore, We performed transfection of cancer cell line (SW620) with pre-miR-124(mimics), anti-miR-124(inhibitor), ROCK1 siRNA and the control, then observed the affects of ROCK1 protein expression by westen-blot, cell proliferation by EDU ( 5-ethynyl-2’deoxyuridine assay) and expression levels of ROCK1mRNA by qRT-PCR . A soft agar formation assay, Migration and invasion assays were used to determine the effect of regulation of miR-124 and ROCK1, and survivin on the transformation and invasion capability of colorectal cancer cell. Results: MiR-124 expression was significantly downregulated in CRC cell lines compare to normal (P < 0.05). In contrast, ROCK1 protein expression was significantly increased in CRC cell lines compared to the normal (P < 0.05), whereas the gene (ROCK1mRNA) expression remained unaltered (P > 0.05). ROCK1 mRNA was unaltered in cells transfected with miR-124 mimic and miR-124 inhibitor, compared to normal controls. There was a significant reduction in ROCK1 protein in cells transfected with miR-124 mimic and a significant increase in cells transfected with miR-124 inhibitor (P < 0.05). Cell proliferation, transformation and invasion of cells transfected with miR-124 inhibitor were significantly increased compared to those in normal controls (P<0.05). However, cell proliferation, transformation and invasion of cells transfected with ROCK1 siRNA were significantly decreased compared to control (P < 0.05). Conclusions: In conclusion, our results demonstrated that miR-124 not only promoted cancer cell hyperplasia and significantly associated with CRC metastasis and progression, but also downregulated ROCK1 protein expression. More importantly, increased ROCK1 expression or inhibited miR-124 expression may constitute effective new therapeutic strategies for the treatment of renal cancer in the future. [ABSTRACT FROM AUTHOR]

Background: CD151 is highly expressed in breast cancer cells and has been shown to accelerate breast cancer by enhancing cell growth and motility, but its regulation is poorly understood. To explore post-translation regulation of CD151, for example microRNAs, will be of great importance to claim the mechanism. Methods: A luciferase reporter assay was used to determine whether CD151 was a target of miR-124. The levels of CD151 mRNA were detected by real-time PCR and CD151 protein expression was measured by western blot and flow cytometry. The effects of miR-124 expression on growth, apoptosis, cell cycle and motility of breast cancer cells were determined. Results: We discovered that miR-124 directly targets the 3' untranslated region (3'-UTR) of CD151 mRNAs and suppresses its mRNA expression and protein translation. Both siRNA of CD151 and miR-124 mimics could significantly inhibit proliferation of breast cancer cell lines via cell cycle arrest but does not induce apoptosis. Meanwhile, miR-124 mimics significantly inhibited the motility of breast cancer cells. Conclusion: miR-124 plays a critical role in inhibiting the invasive and metastatic potential of breast cancer cells, probably by directly targeting the CD151 genes. Our findings highlight an important role of miR-124 in the regulation of invasion and metastasis by breast cancer cells and suggest a potential application for miR-124 in breast cancer treatment. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The development of interstitial fibrosis and tubular atrophy is a common complication after kidney transplantation and is associated with reduced long-term outcome. The hallmark of tubulointerstitial fibrosis is an increase in extracellular matrix resulting from exaggerated activation of fibroblasts/myofibroblasts, and tubular atrophy is characterized by a decrease in tubular diameter and loss of function. Atrophic epithelial cells may undergo epithelial-to-mesenchymal transition (EMT) with potential differentiation into interstitial fibroblasts. One potential driver of EMT in developing interstitial fibrosis and tubular atrophy is chronic hypoxia. Methods: The expression of 46 EMT-related genes was analyzed in an in vitro hypoxia model in renal proximal tubular epithelial cells (RPTEC). Furthermore, the expression of 342 microRNAs (miR) was evaluated in hypoxic culture conditions. Results: Hypoxic RPTEC expressed markers of a more mesenchymal phenotype and showed an increased expression of matrix metalloproteinase-2 (MMP2). MMP2 expression in RPTEC correlated inversely with a decreased expression of miR-124, which was found to have a putative binding site for the MMP2 transcript. Overexpression of miR-124 inhibited MMP2 protein translation. Hypoxia was associated with increased migration/proliferation of RPTEC which was reversed by miR-124. Conclusions: These results indicate that hypoxia promotes a mesenchymal and migratory phenotype in renal epithelial cells, which is associated with increased MMP2 expression. Hypoxia-dependent MMP2 expression is regulated via a reduced transcription of miR-124. Overexpression of miR-124 antagonizes hypoxia-induced cell migration. Further research is needed to elucidate the functional role of miR-124 and MMP2 in the development of fibrosis in renal transplant degeneration. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]