The let-7 tumor suppressor microRNAs are known for their regulation of oncogenes, while the RNA-binding proteins Lin28a/b promote malignancy by inhibiting let-7 biogenesis. We have uncovered unexpected roles for the Lin28/let-7 pathway in regulating metabolism. When overexpressed in mice, both Lin28a and LIN28B promote an insulin-sensitized state that resists high-fat-diet induced diabetes. Conversely, muscle-specific loss of Lin28a or overexpression of let-7 results in insulin resistance and impaired glucose tolerance. These phenomena occur, in part, through the let-7-mediated repression of multiple components of the insulin-PI3K-mTOR pathway, including IGF1R, INSR, and IRS2. In addition, the mTOR inhibitor, rapamycin, abrogates Lin28a-mediated insulin sensitivity and enhanced glucose uptake. Moreover, let-7 targets are enriched for genes containing SNPs associated with type 2 diabetes and control of fasting glucose in human genome-wide association studies. These data establish the Lin28/let-7 pathway as a central regulator of mammalian glucose metabolism.

The Lin28/let-7 Axis Regulates Glucose Metabolism

The inflammasome has an essential function in innate immune, responding to a wide variety of stimuli. Here we show that the lncRNA Neat1 promotes the activation of several inflammasomes. Neat1 associates with the NLRP3, NLRC4, and AIM2 inflammasomes in mouse macrophages to enhance their assembly and subsequent pro-caspase-1 processing. Neat1 also stabilizes the mature caspase-1 to promote interleukin-1β production and pyroptosis. Upon stimulation with inflammasome-activating signals, Neat1, which normally resides in the paraspeckles, disassociates from these nuclear bodies and translocates to the cytoplasm to modulate inflammasome activation using above mechanism. Neat1 is also up-regulated under hypoxic conditions in a HIF-2α-dependent manner, mediating the effect of hypoxia on inflammasomes. Moreover, in the mouse models of peritonitis and pneumonia, Neat1 deficiency significantly reduces inflammatory responses. These results reveal a previously unrecognized role of lncRNAs in innate immunity, and suggest that Neat1 is a common mediator for inflammasome stimuli.

/pdf/the-lncrna-neat1-promotes-activation-of-inflammasomes-in-4hcgh06o8p.pdf

The lncRNA Neat1 promotes activation of inflammasomes in macrophages.

Rationale:MicroRNAs (miRNAs) have been implicated in the epigenetic regulation of key metabolic, inflammatory, and antiangiogenic pathways in type 2 diabetes (DM) and may contribute to common disease complications. Objective:In this study, we explore plasma miRNA profiles in patients with DM. Methods and Results:Total RNA was extracted from plasma samples of the prospective population-based Bruneck study. A total of 13 candidate miRNAs identified by microarray screening and miRNA network inference were quantified by quantitative PCR in all diabetic patients of the Bruneck study and age- and sex-matched controls (1995 evaluation, n=80 each). Quantitative PCR assessment revealed lower plasma levels of miR-20b, miR-21, miR-24, miR-15a, miR-126, miR-191, miR-197, miR-223, miR-320, and miR-486 in prevalent DM, but a modest increase of miR-28-3p. Findings emerged as robust in multivariable analysis and were independent of the standardization procedure applied. For endothelial miR-126, results were confirmed in ...

Plasma MicroRNA Profiling Reveals Loss of Endothelial MiR-126 and Other MicroRNAs in Type 2 Diabetes

Inflammation is involved in pathogenesis of hypertension. NLRP3 inflammasome activation is a powerful mediator of inflammatory response via caspase-1 activation. The present study was designed to determine the roles and mechanisms of NLRP3 inflammasome in phenotypic modulation and proliferation of vascular smooth muscle cells (VSMCs) in hypertension. Experiments were conducted in spontaneously hypertensive rats (SHR) and primary aortic VSMCs. NLRP3 inflammasome activation was observed in the media of aorta in SHR and in the VSMCs from SHR. Knockdown of NLRP3 inhibited inflammasome activation, VSMC phenotypic transformation and proliferation in SHR-derived VSMCs. Increased NFκB activation, histone acetylation and histone acetyltransferase expression were observed in SHR-derived VSMCs and in media of aorta in SHR. Chromatin immunoprecipitation analysis revealed the increased histone acetylation, p65-NFκB and Pol II occupancy at the NLRP3 promoter in vivo and in vitro. Inhibition of NFκB with BAY11-7082 or inhibition of histone acetyltransferase with curcumin prevented the NLRP3 inflammasome activation, VSMC phenotype switching and proliferation in VSMCs from SHR. Moreover, curcumin repressed NFκB activation. Silencing of NLRP3 gene ameliorated hypertension, vascular remodeling, NLRP3 inflammasome activation and phenotype switching in the aorta of SHR. These results indicate that NLRP3 inflammasome activation response to histone acetylation and NFκB activation contributes to VSMC phenotype switching and proliferation and vascular remodeling in hypertension.

/pdf/nlrp3-inflammasome-activation-contributes-to-vsmc-phenotypic-3ossfqtvu1.pdf

NLRP3 inflammasome activation contributes to VSMC phenotypic transformation and proliferation in hypertension.

Regulation of Nuclear Factor-KappaB (NF-κB) signaling pathway by non-coding RNAs in cancer: Inhibiting or promoting carcinogenesis?

Increasing studies have shown that circRNA is closely related to the carcinogenesis and development of many cancers. However, biological functions and the underlying molecular mechanism of circRNAs in triple-negative breast cancer (TNBC) remain largely unclear so far. Here, we investigated the expression pattern of circRNAs in four pairs of TNBC tissues and paracancerous normal tissues using RNA-sequencing. The expression and prognostic significance of circSEPT9 were evaluated with qRT-PCR and in situ hybridization in two TNBC cohorts. The survival curves were drawn by the Kaplan-Meier method, and statistical significance was estimated with the log-rank test. A series of in vitro and in vivo functional experiments were executed to investigate the role of circSEPT9 in the carcinogenesis and development of TNBC. Mechanistically, we explored the potential regulatory effects of E2F1 and EIF4A3 on biogenesis of circSEPT9 with chromatin immunoprecipitation (ChIP), luciferase reporter and RNA immunoprecipitation (RIP) assays. Furthermore, fluorescent in situ hybridization (FISH), luciferase reporter and biotin-coupled RNA pull-down assays were implemented to verify the relationship between the circSEPT9 and miR-637 in TNBC. Increased expression of circSEPT9 was found in TNBC tissues, which was positively correlated with advanced clinical stage and poor prognosis. Knockdown of circSEPT9 significantly suppressed the proliferation, migration and invasion of TNBC cells, induced apoptosis and autophagy in TNBC cells as well as inhibited tumor growth and metastasis in vivo. Whereas up-regulation of circSEPT9 exerted opposite effects. Further mechanism research demonstrated that circSEPT9 could regulate the expression of Leukemia Inhibitory Factor (LIF) via sponging miR-637 and activate LIF/Stat3 signaling pathway involved in progression of TNBC. More importantly, we discovered that E2F1 and EIF4A3 might promote the biogenesis of circSEPT9. Our data reveal that the circSEPT9 mediated by E2F1 and EIF4A3 facilitates the carcinogenesis and development of triple-negative breast cancer through circSEPT9/miR-637/LIF axis. Therefore, circSEPT9 could be used as a potential prognostic marker and therapeutical target for TNBC.

The circRNA circSEPT9 mediated by E2F1 and EIF4A3 facilitates the carcinogenesis and development of triple-negative breast cancer

Diabetic nephropathy (DN) as the primary cause of end-stage kidney disease is a common complication of diabetes. Recent researches have shown the activation of nuclear factor kappa light-chain enhancer of activated B cells (NF-κB) and NACHT, LRR and PYD domain-containing protein 3 (NLRP3) inflammasome are associated with inflammation in the progression of DN, but the exact mechanism is unclear. Long noncoding RNAs (lncRNAs) have roles in the development of many diseases including DN. However, the relationship between lncRNAs and inflammation in DN remains largely unknown. Our previous study has revealed that 14 lncRNAs are abnormally expressed in DN by RNA sequencing and real-time quantitative PCR (qRT-PCR) in the renal tissues of db/db DN mice. In this study, these lncRNAs were verified their expressions by qRT-PCR in mesangial cells (MCs) cultured under high- and low-glucose conditions. Twelve lncRNAs displayed the same expressional tendencies in both renal tissues and MCs. In particular, long intergenic noncoding RNA (lincRNA)-Gm4419 was the only one associating with NF-κB among these 12 lncRNAs by bioinformatics methods. Moreover, Gm4419 knockdown could obviously inhibit the expressions of pro-inflammatory cytokines and renal fibrosis biomarkers, and reduce cell proliferation in MCs under high-glucose condition, whereas overexpression of Gm4419 could increase the inflammation, fibrosis and cell proliferation in MCs under low-glucose condition. Interestingly, our results showed that Gm4419 could activate the NF-κB pathway by directly interacting with p50, the subunit of NF-κB. In addition, we found that p50 could interact with NLRP3 inflammasome in MCs. In conclusion, our findings suggest lincRNA-Gm4419 may participate in the inflammation, fibrosis and proliferation in MCs under high-glucose condition through NF-κB/NLRP3 inflammasome signaling pathway, and may provide new insights into the regulation of Gm4419 during the progression of DN.

/pdf/lincrna-gm4419-knockdown-ameliorates-nf-kb-nlrp3-57x009tepr.pdf

LincRNA-Gm4419 knockdown ameliorates NF-κB/NLRP3 inflammasome-mediated inflammation in diabetic nephropathy.

Diabetic nephropathy (DN) is one of the most significant complications of diabetes and is the primary cause of end-stage kidney disease. Cumulating evidence has shown that renal inflammation plays a role in the development and progression of DN, but the exact cellular mechanisms are unclear. Irregular expression of long non-coding RNAs (lncRNAs) is present in many diseases, including DN. However, the relationship between lncRNAs and inflammation in DN is unclear. In this study, we identified differentially expressed lncRNAs in DN using RNA-sequencing. Among these lncRNAs, we identified seven DN-related lncRNAs in vivo and in vitro using quantitative real-time PCR. One lncRNA in particular, Rpph1 (ribonuclease P RNA component H1), exhibited significantly increased expression. Further, over-expression or knockdown of Rpph1 was found to regulate cell proliferation and the expression of inflammatory cytokines in mesangial cells (MCs). The results revealed that Rpph1 directly interacts with the DN-related factor galectin-3 (Gal-3). Further, over-expression of Rpph1 promoted inflammation and cell proliferation through the Gal-3/Mek/Erk signaling pathway in MCs under low glucose conditions, while knockdown of Rpph1 inhibited inflammation and cell proliferation through the Gal-3/Mek/Erk pathway in MCs under high glucose conditions. These results provide new insight into the association between Rpph1 and the Gal-3/Mek/Erk signaling pathway during DN progression.

/pdf/long-non-coding-rna-rpph1-promotes-inflammation-and-4txg47rd9y.pdf

Long non-coding RNA Rpph1 promotes inflammation and proliferation of mesangial cells in diabetic nephropathy via an interaction with Gal-3.

Promoter hypermethylation of let-7a-3 is relevant to its down-expression in diabetic nephropathy by targeting UHRF1.

Background/aims Triple-negative breast cancer (TNBC) is a subtype of highly malignant breast cancer with poor prognosis. Growing evidence indicates that Long noncoding RNAs (lncRNAs) play important regulatory roles in the development and progression of a variety of cancers including breast cancer. However, the underlying mechanisms remain largely unknown. Methods Here, we compared the expression profiles of mRNAs, lncRNAs and miRNAs between 111 TNBC tissues and 104 non-cancerous tissues utilizing RNA-Seq Data from The Cancer Genome Atlas (TCGA). Gene Ontology and KEGG pathway enrichment analyses were executed to investigate the principal functions of the significantly dysregulated mRNAs. Moreover, Kaplan-Meier survival analyses were performed to determine the effects of differentially expressed lncRNAs/mRNAs/miRNAs on overall survival. Subsequently, we constructed a competing endogenous RNA (ceRNA) network, which included 66 dysregulated lncRNAs, 24 miRNAs and 55 mRNAs. The four dysregulated lncRNAs, three aberrantly expressed miRNAs and four mRNAs were confirmed in the ceRNA network by qRT-PCR in 30 pairs of samples, respectively. Results A total of 1441 lncRNAs, 114 miRNA and 2501 mRNAs were found to be differentially expressed in TNBC tissues compared with controls. 109 lncRNAs and 124 mRNAs might serve as prognostic signature for patients with TNBC according to the survival analysis. Functional analysis revealed that 19 mRNAs in the ceRNA network were enriched in 17 cancer-related pathways. Conclusion Taken together, we identified novel lncRNAs/miRNAs which may serve as potential biomarkers to predict the survival and therapeutic targets for TNBC patients based on a large-scale sample. More importantly, we constructed the ceRNA network of TNBC, which provides valuable information to further explore the molecular mechanism underlying tumorigenesis and development of TNBC.

/pdf/comprehensive-analysis-of-differentially-expressed-profiles-4y75rlxs63.pdf

Comprehensive Analysis of Differentially Expressed Profiles of lncRNAs/mRNAs and miRNAs with Associated ceRNA Networks in Triple-Negative Breast Cancer.

Luyu Zhang

Papers

The circRNA circSEPT9 mediated by E2F1 and EIF4A3 facilitates the carcinogenesis and development of triple-negative breast cancer

LincRNA-Gm4419 knockdown ameliorates NF-κB/NLRP3 inflammasome-mediated inflammation in diabetic nephropathy.

Long non-coding RNA Rpph1 promotes inflammation and proliferation of mesangial cells in diabetic nephropathy via an interaction with Gal-3.

Promoter hypermethylation of let-7a-3 is relevant to its down-expression in diabetic nephropathy by targeting UHRF1.

Comprehensive Analysis of Differentially Expressed Profiles of lncRNAs/mRNAs and miRNAs with Associated ceRNA Networks in Triple-Negative Breast Cancer.