LINC00271 inhibits epithelial-mesenchymal transition of papillary thyroid cancer cells by downregulating trefoil factor 3 expression

Inhibition of YTHDF1 prevents hypoxia-induced pulmonary artery smooth muscle cell proliferation by regulating Foxm1 translation in an m6A-dependent manner

Pulmonary arterial hypertension (PAH) is a chronic disease characterized by pulmonary vascular remodeling. It refers to the abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs), and hypoxia is an important risk factor for this progression. The present study aims to investigate the role of YTHDF1 in the regulation of hypoxic PASMC proliferation and the underlying mechanism. Human PASMCs were transfected with si-YTHDF1/2/3 followed by treatment of hypoxia, and the PASMC proliferation and Foxm1 expression were detected. Through RNA pull-down, RNA immunoprecipitation, and protein synthesis assay, the mechanism of YTHDF1 regulating Foxm1 was explored. Next, Foxm1 was inhibited by thiostrepton, and cell proliferation was detected. In vivo, mice received a tail vein injection of adenovirus containing si-YTHDF1 and were exposed to hypoxia treatment. Pulmonary vascular changes, right ventricular systolic pressure (RVSP), and genes involving proliferation were analyzed. YTHDF1 silencing reduced more hypoxic PASMC proliferation and Foxm1 protein level than YTHDF2/3 silencing. Mechanical results showed that YTHDF1 interacted with Foxm1 mRNA and up-regulated Foxm1 protein level by enhancing the translation efficiency in an m6A-dependent manner. Furthermore, YTHDF1 facilitated hypoxic PASMC proliferation and proliferation marker expressions through up-regulation of Foxm1 in an m6A-dependent manner. In vivo, the YTHDF1 silencing alleviated pulmonary vascular changes and fibrosis, reduced RVSP, inhibited the interaction of YTHDF1 and Foxm1, and reduced proliferation marker levels, as compared to the PAH group. In conclusion, YTHDF1 silencing inhibits hypoxic PASMC proliferation by regulating Foxm1 translation in an m6A-dependent manner.

LncRNA MAPKAPK5_AS1 facilitates cell proliferation in hepatitis B virus -related hepatocellular carcinoma

We explored the biological role of long non-coding RNA (lncRNA) MAPKAPK5_AS1 (MAAS) and the mechanism of its differential expression in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Differentially expressed lncRNAs in HBV-related HCC were determined using bioinformatics analysis. Gain-of-function experiments were conducted to evaluate the effect of MAAS on cell proliferation. A xenograft model was established for in vivo experiments. Dual-luciferase reporter assays, chromatin immunoprecipitation, co-immunoprecipitation, and methylated RNA immunoprecipitation were performed to elucidate the underlying molecular mechanisms. MAAS was upregulated in HBV-related HCC cancerous tissues and its high expression was closely related to the poor survival probability of patients. Functional assays revealed that MAAS overexpression facilitated the proliferation of HBV⁺HCC cells in vitro and in vivo. Mechanistically, MAAS promoted the MYC proto-oncogene (c-Myc)-induced transcriptional activation of cyclin-dependent kinase 4 (CDK4), CDK6, and S-phase kinase associated protein 2 via stabilizing c-Myc protein, thereby facilitating G1/S transition. The latter contributed to the paradoxical proliferation of HBV⁺HCC cells. Although MAAS was upregulated in HBV-related HCC cancerous tissues, it was highly expressed in M2 macrophages, a major phenotype of tumor-associated macrophages in HBV-related HCC, instead of in HBV⁺HCC cells. HBeAg, an HBV-associated antigen, further elevated the MAAS level in M2 macrophages by enhancing the methyltransferase-like 3-mediated N6-methyladenosine modification of MAAS. The increased MAAS in the M2 macrophages was then transferred to HBV⁺HCC cells through the M2 macrophage-derived exosomes, promoting cell proliferation. Our findings show that HBV⁺HCC cell-secreted HBeAg upregulates MAAS expression in M2 macrophages by affecting its m⁶A modification. The upregulated MAAS is then transferred to HBV⁺HCC cells via exosomes, facilitating the proliferation of HBV⁺HCC cells by targeting c-Myc.

Exosomal transfer of activated neutrophil-derived lncRNA CRNDE promotes proliferation and migration of airway smooth muscle cells in asthma

BACKGROUND

Activated neutrophil-derived exosomes reportedly contribute to the proliferation of airway smooth muscle cells (ASMCs), thereby aggravating the airway wall remodeling during asthma; however, the specific mechanism remains unclear.

METHODS

Lipopolysaccharide (LPS)-EXO and si-CRNDE-EXO were extracted from the media of human neutrophils treated with LPS and LPS + si-CRNDE (a siRNA targets long non-coding RNA CRNDE), respectively. Human ASMCs were co-cultured with LPS-EXO or si-CRNDE-EXO, and cell viability, proliferation, and migration were measured. The interplay of CRNDE, inhibitor of nuclear factor kappa B kinase subunit beta (IKKβ), and nuclear receptor subfamily 2 group C member 2 (TAK1) was explored using RNA immunoprecipitation (RIP) and Co-IP assays. A mouse model of asthma was induced using ovalbumin.

RESULTS

CRNDE was upregulated in LPS-EXO and successfully transferred from LPS-treated neutrophils to ASMCs through exosome. Mechanically, CRNDE loaded in LPS-EXO reinforced TAK1-mediated IKKβ phosphorylation, thereby activating the nuclear factor kappa B (NF-κB) pathway. Functionally, silencing CRNDE in LPS-EXO, an IKKβ inhibitor, and an NF-κB inhibitor all removed the upregulation of cell viability, proliferation, and migration induced by LPS-EXO in ASMCs. In the end, the in vivo experiment demonstrated that CRNDE knockdown in neutrophils effectively reduced the thickness of bronchial smooth muscle in a mouse model for asthma.

CONCLUSION

Activated neutrophils-derived CRNDE was transferred to ASMCs through exosomes and activated the NF-κB pathway by enhancing IKKβ phosphorylation. The latter promoted the proliferation and migration of ASMCs and then contributed to airway remodeling in asthma.

HNRNPA1-mediated exosomal sorting of miR-483-5p out of renal tubular epithelial cells promotes the progression of diabetic nephropathy-induced renal interstitial fibrosis

Diabetic nephropathy (DN) is a serious complication in type 1 and type 2 diabetes, and renal interstitial fibrosis plays a key role in DN progression. Here, we aimed to probe into the role and potential mechanism of miR-483-5p in DN-induced renal interstitial fibrosis. In this study, we corroborated that miR-483-5p expression was lessened in type 1 and type 2 diabetic mice kidney tissues and high glucose (HG)-stimulated tubular epithelial cells (TECs), and raised in the exosomes derived from renal tissues in type 1 and type 2 diabetic mice. miR-483-5p restrained the expressions of fibrosis-related genes in vitro and renal interstitial fibrosis in vivo. Mechanistically, miR-483-5p bound both TIMP2 and MAPK1, and TIMP2 and MAPK1 were bound up with the regulation of miR-483-5p on renal TECs under HG conditions. Importantly, HNRNPA1-mediated exosomal sorting transported cellular miR-483-5p out of TECs into the urine. Our results expounded that HNRNPA1-mediated exosomal sorting transported cellular miR-483-5p out of TECs into the urine, thus lessening the restraint of cellular miR-483-5p on MAPK1 and TIMP2 mRNAs, and ultimately boosting extracellular matrix deposition and the progression of DN-induced renal interstitial fibrosis.

LncRNA SNHG5 promotes cervical cancer progression by regulating the miR-132/SOX4 pathway

BACKGROUND

The long non-coding RNA (lncRNA) small nucleolar RNA host gene 5 (SNHG5) has been verified as a crucial regulator in many types of tumours but not clear in cervical cancer (CC). This study aims to investigate the effect and further mechanisms of lncRNA SNHG5 in CC.

METHODS

The expression of SNHG5 and miR-132, as well as SOX4 (sex-determining region Y-box 4) mRNA expression were determined by quantitative real-time PCR (qRT-PCR). The protein level of SOX4 and epithelial-mesenchymal transition (EMT)-related proteins were evaluated by western blot. Then, Edu and Transwell assay were performed to assess the proliferation, migration and invasion of CC cells. RNA immunoprecipitation (RIP) and RNA pull-down assay were conducted to explore the relationship between SNHG5 and miR-132.

RESULTS

SNHG5 and SOX4 were upregulated, and miR-132 was downregulated in CC tissues and cell lines. SNHG5 was positively correlated with FIGO stage (p = .003) and lymph node metastasis (p = .001). Pearson's correlation analysis conveyed that SNHG5 was positively correlated with SOX4, and miR-132 was negatively correlated with SOX4 and SNHG5. Knockdown of SNHG5 in vitro reduced CC cell proliferation, migration and invasion through regulating miR-132. Moreover, overexpression of miR-132 restrained CC cell proliferation, migration, and invasion through targeting SOX4, and SNHG5 enhanced SOX4 expression via negatively regulating miR-132.

CONCLUSION

SNHG5 promotes SOX4 expression to accelerate CC cell proliferation, migration and invasion through negatively regulating miR-132.

lncRNA-CRNDE regulates BMSC chondrogenic differentiation and promotes cartilage repair in osteoarthritis through SIRT1/SOX9

Osteoarthritis (OA) is the most common chronic and degenerative joint disease. Although traditional OA medications can partially relieve pain, these medications cannot completely cure OA. Therefore, it is particularly important to find an effective treatment for OA. This study explored the function of long non-coding RNA (lncRNA)-colorectal neoplasia differentially expressed gene (CRNDE) in the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and the underlying molecular mechanism, aiming to develop a new treatment method for osteoarthritis. BMSCs were isolated from rat bone marrow using the gradient centrifugation method. And BMSC chondrogenic differentiation was induced with chondrogenic medium. The expression of lncRNA-CRNDE was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Silent information regulator factor 2-related enzyme 1 (SIRT1) and cartilage marker genes Aggrecan and collagen 2 (α1) protein expression were researched using western blot. Alcian blue staining was employed to examine the content of cartilage matrix proteoglycan glycosaminoglycan (GAG). The interaction between lncRNA-CRNDE and SIRT1 was detected by RNA pull-down and RNA immunoprecipitation (RIP) assay. Ubiquitination experiments were performed to measure the ubiquitination level of SIRT1. The combination between SMAD ubiquitination regulatory factor 2 (SMURF2) and SIRT1, as well as SRY-related high-mobility-group box 9 (SOX9) and collagen 2 (α1) promoter, was detected by Co-immunoprecipitation or ChIP. With the prolongation of induction time, the expression of lncRNA-CRNDE, SIRT1, cartilage marker genes Aggrecan and collagen 2 (α1) in BMSC osteogenic differentiation was gradually increased. Also, the content of cartilage matrix proteoglycan GAG was gradually elevated with the extension of the induction time. Further increase in the expression of SIRT1, cartilage marker genes Aggrecan and collagen 2 (α1) by overexpression of lncRNA-CRNDE also indicated elevated GAG content. RNA pull-down and RIP assay confirmed the binding between lncRNA-CRNDE and SIRT1. qRT-PCR and western blot showed that interference with lncRNA-CRNDE significantly inhibited the protein expression of SIRT1. BMSCs transfected with si-CRNDE increased ubiquitination levels of SIRT1 mediated by the E3 ligase SMURF2, leading to the reduced protein stability of SIRT1. However, overexpression of lncRNA-CRNDE increased the binding ability of SOX9 and collagen 2 (α1) promoter, which was reversed by the simultaneous transfection of CRNDE overexpression (pcDNA-CRNDE) and SIRT1 small interfering RNA (si-SIRT1). lncRNA-CRNDE regulates BMSC chondrogenic differentiation to promote cartilage repair in osteoarthritis through SIRT1/SOX9.

Up-regulation of LncRNA NEAT1 induces apoptosis of human placental trophoblasts

The trophoblast apoptosis induced by placental oxidative stress is a contributor to the pathological development of preeclampsia (PE), whereas the molecular mechanism remains unclear. In this study, we explored the role and mechanism of Long non-coding RNA (LncRNA) NEAT1 in trophoblasts apoptosis. In the placenta tissues of PE patients and H₂O₂-treated human trophoblast cell line HTR-8/SVneo, the expressions of LncRNA NEAT1, p53, and estrogen receptor α (ESRα) were increased whereas miR-18a-5p expression was decreased. ESRα expression was up-regulated by LncRNA NEAT1 overexpression and down-regulated by miR-18a-5p overexpression in HTR-8/SVneo cells. LncRNA NEAT1 could release ESRα expression through sponging miR-18a-5p and the transcription of LncRNA NEAT1 was promoted by p53. miR-18a-5p overexpression suppressed H₂O₂-induced cell apoptosis in HTR-8/SVneo cells, while the inhibitory effect of miR-18a-5p overexpression on cell apoptosis was abrogated by LncRNA NEAT1 overexpression. In summary, LncRNA NEAT1 transcription was induced by p53 under oxidative stress condition, the high expression of LncRNA NEAT1 subsequently increased ESRα expression by sponging miR-18a-5p, thus inducing trophoblasts apoptosis.