scholarly journals Down‐regulation of the Sp1 transcription factor by an increase of microRNA-4497 in human placenta is associated with early recurrent miscarriage

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Huaiyun Tang ◽  
Linqing Pan ◽  
Yun Xiong ◽  
Leilei Wang ◽  
Yugui Cui ◽  
...  

Abstract Background The pathophysiological mechanism of recurrent miscarriage (RM) is unclear. The goals of this study were to determine the role of microRNA-4497 overexpression in placental villus tissues in early RM; To identify the potential target mRNAs of miRNA-4497; And to investigate the microRNA-4497-mediated regulatory mechanisms in placental trophoblasts. Methods Bioinformatics analysis was performed to identify the candidate target genes of miRNA-4497. The protein expression of Sp1 transcription factor (SP1), chemokine (C-X-C motif) receptor 5 (CXCR5) and bone morphogenetic protein 8a (BMP8A) were determined in the villus tissues of the RM and normal groups by Western blotting and immunohistochemistry. Cultured 293T cells were co-transfected with the miRNA-4497 agomir or luciferase reporter vectors containing the wild-type or mutant 3’-UTRs of the target mRNAs to verify the regulatory role of miRNA-4497. Results Bioinformatics analysis suggested that SP1, CXCR5 and BMP8A mRNAs are potential targets of miRNA-4497. The expression of SP1, CXCR5 and BMP8A proteins in the chorionic villus tissues of RM placentas were significantly decreased compared to those in the normal controls. Moreover, SP1 protein levels were inversely correlated with the levels of miRNA-4497 in the placentas of RM patients and normal controls. The expression of SP1 mRNA and protein were down-regulated in HTR-8/SVneo cells after forced overexpression of the miRNA-4497 agomir. The results of the co-transfection assay showed that mutation of the miRNA-4497-binding sites in the 3’-untranslated region (3’-UTR) of SP1 led to a recovery of luciferase activity upon overexpression of miRNA-4497, suggesting that SP1 could be a direct target of miRNA-4497. Conclusions An increased miRNA-4497 level in the placental villus tissues associated with recurrent miscarriage may down-regulate SP1 expression. The negative regulation of SP1 by miRNA-4497 may potentially contribute to the pathogenesis of recurrent miscarriage through promotion of trophoblast apoptosis. These findings provide novel information on the regulation of placental trophoblast apoptosis, and could be useful for the development of new therapeutic strategies for better management of recurrent miscarriage.

2021 ◽  
Vol 12 (9) ◽  
Author(s):  
Xuexiu Zhang ◽  
Jianning Yao ◽  
Haoling Shi ◽  
Bing Gao ◽  
Haining Zhou ◽  
...  

AbstractCircular RNAs (circRNAs) have been reported to play crucial roles in the progression of various cancers, including colorectal cancer (CRC). SP1 (Sp1 transcription factor) is a well-recognized oncogene in CRC and is deemed to trigger the Wnt/β-catenin pathway. The present study was designed to investigate the role of circRNAs which shared the same pre-mRNA with SP1 in CRC cells. We identified that hsa_circ_0026628 (circ_0026628), a circular RNA that originated from SP1 pre-mRNA, was upregulated in CRC cells. Sanger sequencing and agarose gel electrophoresis verified the circular characteristic of circ_0026628. Functional assays including CCK-8, colony formation, transwell, immunofluorescence staining, and sphere formation assay revealed the function of circ_0026628. RNA pull-down and mass spectrometry disclosed the proteins interacting with circ_0026628. Mechanistic assays including RIP, RNA pull-down, CoIP, ChIP, and luciferase reporter assays demonstrated the interplays between molecules. The results depicted that circ_0026628 functioned as a contributor to CRC cell proliferation, migration, EMT, and stemness. Mechanistically, circ_0026628 served as the endogenous sponge of miR-346 and FUS to elevate SP1 expression at the post-transcriptional level, thus strengthening the interaction between SP1 and β-catenin to activate the Wnt/β-catenin pathway. In turn, the downstream gene of Wnt/β-catenin signaling, SOX2 (SRY-box transcription factor 2), transcriptionally activated SP1 and therefore boosted circ_0026628 level. On the whole, SOX2-induced circ_0026628 sponged miR-346 and recruited FUS protein to augment SP1, triggering the downstream Wnt/β-catenin pathway to facilitate CRC progression.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ti-Dong Shan ◽  
Han Yue ◽  
Xue-Guo Sun ◽  
Yue-Ping Jiang ◽  
Li Chen

Abstract Background The complications caused by diabetes mellitus (DM) are the focus of clinical treatment. However, little is known about diabetic enteropathy (DE) and its potential underlying mechanism. Methods Intestinal epithelial cells (IECs) and intestinal epithelial stem cells (IESCs) were harvested from BKS.Cg-Dock7m+/+Leprdb/JNju (DM) mice, and the expression of R-Spondin 3 (Rspo3) was detected by RT-qPCR, Western blotting, immunohistochemistry, and immunofluorescence. The role of Rspo3 in the abnormal differentiation of IECs during DM was confirmed by knockdown experiments. Through miRNA expression profiling, bioinformatics analysis, and RT-qPCR, we further analyzed the differentiation-related miRNAs in the IECs from mice with DM. Results Abnormal differentiation of IECs was observed in the mice with DM. The expression of Rspo3 was upregulated in the IECs from the mice with DM. This phenomenon was associated with Rspo3 overexpression. Additionally, Rspo3 is a major determinant of Lgr5+ stem cell identity in the diabetic state. Microarray analysis, bioinformatics analysis, and luciferase reporter assays revealed that microRNA (miR)-380-5p directly targeted Rspo3. Moreover, miR-380-5p upregulation was observed to attenuate the abnormal differentiation of IECs by regulating Rspo3 expression. Conclusions Together, our results provide definitive evidence of the essential role of Rspo3 in the differentiation of IECs in DM.


Life Sciences ◽  
2008 ◽  
Vol 83 (9-10) ◽  
pp. 305-312 ◽  
Author(s):  
Solomon S. Solomon ◽  
Gipsy Majumdar ◽  
Antonio Martinez-Hernandez ◽  
Rajendra Raghow

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Zhihao Xu ◽  
Dapeng Dong ◽  
Xiaofei Chen ◽  
Huaqiong Huang ◽  
Shenglan Wen

It is widely reported that miR-381 is dysregulated in various tumors. However, the specific role of miR-381 in respiratory infections has not been reported. To probe this role, A549 cells were pretreated with 1 μg/mL LPS for 24 h. The level of miR-381 was detected using RT-qPCR. The expression of proinflammatory cytokines was determined using an ELISA kit and western blotting. Bioinformatics analysis was used to predict the target genes of miR-381, and a luciferase reporter assay was used to validate the expression of the target genes. miR-381 expression was increased in A549 cells treated with LPS, which is a ligand of TLRs. Further study revealed that the overexpression of miR-381 increased the activity of NF-κB signaling, thereby increasing the expression of IL-6, TNFα, and COX-2. Further study revealed that IκBα was a target gene of miR-381. The upregulation of miR-381 under LPS stimulation contributes to respiratory infections mainly by targeting IκBα.


Author(s):  
Yang Sun ◽  
Jun-Gong Jin ◽  
Wei-Yang Mi ◽  
Hao-Wu ◽  
Shi-Rong Zhang ◽  
...  

Glioma is the most common and lethal malignant intracranial tumor. Long noncoding RNAs (lncRNAs) have been identified as pivotal regulators in the tumorigenesis of glioma. However, the role of lncRNA urothelial carcinoma-associated 1 (UCA1) in glioma genesis is still unknown. The purpose of this study was to investigate the underlying function of UCA1 on glioma genesis. The results demonstrated that UCA1 was upregulated in glioma tissue and indicated a poor prognosis. UCA1 knockdown induced by si-UCA1 significantly suppressed the proliferative, migrative, and invasive activities of glioma cell lines (U87 and U251). Bioinformatics analysis and luciferase reporter assay verified the complementary binding within UCA1 and miR-122 at the 3-UTR. Functional experiments revealed that UCA1 acted as an miR-122 sponge to modulate glioma cell proliferation, migration, and invasion via downregulation of miR-122. Overall, the present study demonstrated that lncRNA UCA1 acts as an endogenous sponge of miR-122 to promote glioma cell proliferation, migration, and invasion, which provides a novel insight and therapeutic target in the tumorigenesis of glioma.


2020 ◽  
Author(s):  
Feng Liu ◽  
Hao Wu ◽  
Guangyong Wu ◽  
Jun Long ◽  
Jin Dai ◽  
...  

Abstract Background: Long noncoding RNAs are widely studied in glioma. However, the role of the lncRNA NEAT1 and KDM3A in glioma has not yet been reported. We aimed to reveal the role of these two lncRNAs in the development of glioma through this study.Methods: Samples from glioma patients and normal brain tissues were collected, and the expression of NEAT1 was detected by qRT-PCR. A dual-luciferase reporter gene assay, chromatin immunoprecipitation (ChIP), RNA-binding protein immunoprecipitation (RIP), and RNA pulldown experiments were used to identify the relationship between FOXK1, NEAT1, miR-128, and KDM3A. The CCK8 assay, Transwell assay and flow cytometry were used to detect cell viability, invasion and migration ability, and the cell cycle and apoptosis, respectively. Tumor formation experiments verified the effect of NEAT1 on gliomas in vivo.Results: FOXK1 and NEAT1 were significantly overexpressed in glioma tissues and cells, and NEAT1 was significantly related to WHO classification. FOXK1 bound the NEAT1 gene promoter region in glioma cells, and interference with FOXK1 inhibited NEAT1 expression. NEAT1 inhibited miR-128 expression by binding miR-128; significantly improved cell viability and invasion and migration capabilities; increased the expression of KDM3A and activated the Wnt signaling pathway. Interference with KDM3A reversed the above results. In addition, interference with NEAT1 decreased KDM3A expression and inhibited tumor growth.Conclusion: Interference with NEAT1 promoted the expression of miR-128, thereby suppressing the expression of KDM3A and inhibiting the occurrence and development of glioma, while the expression of NEAT1 was shown to be regulated by the upstream transcription factor FOXK1.


2012 ◽  
Vol 90 ◽  
pp. 0-0
Author(s):  
K DONOVAN ◽  
O ALEKSEEV ◽  
W CHO ◽  
J AZIZKHAN-CLIFFORD

2020 ◽  
Author(s):  
kunwei niu ◽  
Shibin Qu ◽  
Xuan Zhang ◽  
Jimin Dai ◽  
Jianlin Wang ◽  
...  

Abstract Background: To investigate the underlying mechanisms of lncRNA URHC in HCC. Methods: RT-qPCR, FISH staining, EdU, colony formation, and tumor xenografts experiments were used to identify localized and biological effects of URHC on HCC cells in vitro and in vivo. The Bioinformatics analysis, Dual- luciferase reporter assay, and rescue experiments revealed the potential mechanism of URHC. Results: We found that URHC was mainly localized in the cytoplasm. URHC silencing may inhibit the HCC cells proliferation. And URHC positively regulated the level of DNAJB9 by sponging miR-5007-3p. Conclusion: Together, our study elucidated the role of URHC as a miRNA sponge in HCC, and shed new light on lncRNA-directed diagnostics and therapeutics in HCC.


2017 ◽  
Vol 44 (2) ◽  
pp. 505-514 ◽  
Author(s):  
Minghui Liu ◽  
Kai Yin ◽  
Xu Guo ◽  
Huijin Feng ◽  
Min Yuan ◽  
...  

Background/Aims: This study focused on the oncogenic role of Diphthamide biosynthesis 1 (DPH1) in colorectal cancer (CRC) cells. Methods: The expression of DPH1 was determined by quantitative RT-PCR analysis and western blotting in CRC tissues. The role of DPH1 in CRC cells was investigated via cell viability and invasion assays under the condition of DPH1 silencing or overexpression. Bioinformatics analysis and luciferase reporter analysis were used to identify the upstream microRNA which might regulate DPH1.The inverse correlation between the microRNA and DPH1 was also detected in CRC cells. Results: We identified an unexpected role for DPH1 as an oncogene in CRC cells. The tumour-suppressive miR-218-5p regulates DPH1 directly and negatively. Loss of miR-218-5p drives the oncogenic role of DPH1 in CRC cells. Conclusion: The modulation of DPH1 by miR-218-5p may be an important regulatory axis during CRCtumourigenesis.


2021 ◽  
Author(s):  
Jing Ye ◽  
Xiaozhen Chen ◽  
Bing Liao ◽  
Xiaohua Jiang ◽  
Zhihuai Dong ◽  
...  

Abstract Background Emerging as the most abundant posttranscriptional internal mRNA modification in eukaryotes, N6-methyladenosine (m6A) modification has gathered tremendous scientific interest in recent years. However, no study addresses the role of m6A modification in ferroptosis. Here, we showed that m6A modifications are decreased in RSL3-induced ferroptosis in hypopharyngeal squamous cell carcinoma (HPSCC). We found that AlkB homolog 5 (ALKBH5), one of the m6A demethylases, is the primary factor involved in aberrant m6A modification. Methods Bioinformatics analysis, sample analysis, cell biological analyses and transcriptome sequencing were performed to evaluate the correlation between m6A modification and ferroptosis as well as molecular mechanism of ALKBH5 function. Transcriptome-wide m6A-seq and RIP-seq data and following m6A dot blot, MeRIP-qPCR, RIP-qPCR and dual luciferase reporter assays were mapped to screen and validate the candidate targets of ALKBH5. Results ALKBH5-knockdown impaired ferroptotic cell death in HPSCC. However, overexpression of ALKBH5 has an opposite effect, suggesting that ALKBH5 is a positive regulator of ferroptosis. Mechanistically, ALKBH5-mediated m6A demethylation led to a post-transcriptional inhibition of NFE2L2/NRF2, the central player in the regulation of antioxidant molecules in cells, at two m6A residues in the 3ʹ-UTR. Therefore, knocking down ALKBH5 subsequently increases the expression levels of NFE2L2/NRF2 and increased cell resistance to ferroptosis. In addition, m6A-mediated NFE2L2/NRF2 stabilization relied on the m6A reader IGF2BP2. Conclusion ALKBH5 functions as a tumor suppresser through ferroptosis in HPSCC. ALKBH5 destabilizes NFE2L2/NRF2 expression in HPSCC through an m6A-IGF2BP2-dependent mechanism. Together, our work uncovers a critical link between ALKBH5-NFE2L2/NRF2 and ferroptosis, providing insight into the functional importance of the reversible mRNA m6A methylation and its modulators in HPSCC.


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