Discovery of a macrocyclic γ-AApeptide binding to lncRNA GAS5 and its therapeutic implication in Type 2 diabetes

TGF-β receptor I inhibitor may restrict the induction of EMT in inflamed intestinal epithelial cells

Despite the extensive body of research, understanding the exact molecular mechanisms governing inflammatory bowel diseases (IBDs) still demands further investigation. Transforming growth factor-β1 (TGF-β1) signaling possesses a multifacial effect on a broad range of context-dependent cellular responses. However, long-term TGF-β1 activity may trigger epithelial-mesenchymal transition (EMT), followed by fibrosis. This study aimed to determine the role of epithelial TGF-β1 signaling in inflammatory bowel disease (IBD) pathogenesis. The expression of TGF-β1 signaling components and EMT-related and epithelial tight junction markers was examined in IBD patients (n = 60) as well as LPS-induced Caco-2/RAW264.7 co-culture model using quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting, and immunofluorescence staining. Furthermore, the effect of A83-01, as a TGF-β receptor I (TβRI) inhibitor, on the inflamed epithelial cells was evaluated in vitro. To evaluate the cytotoxic effects of the TβRI inhibitor, a cell viability assay was performed by the MTS method. Considering the activation of canonical and non-canonical TGF-β1 signaling pathways in IBD patients, expression results indicated that administering A83-01 in inflamed Caco-2 cells substantially blocked the expression level of TGF-β1, SMAD4, and PI3K and the phosphorylation of p-SMAD2/3, p-AKT, and p-RPS6 as well as prevented downregulation of LncGAS5 and LncCDKN2B. Further analysis revealed that the inhibition of TGF-β1 signaling in inflamed epithelial cells by the small molecule could suppress the EMT-related markers as well as improve the expression of epithelial adherens and tight junctions. Collectively, these findings indicated that the inhibition of the TGF-β1 signaling could suppress the induction of EMT in inflamed epithelial cells as well as exert a protective effect on preserving tight junction integrity. There is a pressing need to determine the exact cellular mechanisms by which TGF-β1 exerts its effect on IBD pathogenesis.

Long non-coding RNA screening and identification of potential biomarkers for type 2 diabetes

BACKGROUND

To investigate new lncRNAs as molecular markers of T2D.

METHODS

We used microarrays to identify differentially expressed lncRNAs and mRNAs from five patients with T2D and paired controls. Through bioinformatics analysis, qRT-PCR validation, ELISA, and receiver operating characteristic (ROC) curve analysis of 100 patients with T2D and 100 controls to evaluate the correlation between lncRNAs and T2D, and whether lncRNAs could be used in the diagnosis of T2D patients.

RESULTS

We identified 68 and 74 differentially expressed lncRNAs and mRNAs, respectively. The top five upregulated lncRNAs are ENST00000381108.3, ENST00000515544.1, ENST00000539543.1, ENST00000508174.1, and ENST00000564527.1, and the top five downregulated lncRNAs are TCONS_00017539, ENST00000430816.1, ENST00000533203.1, ENST00000609522.1, and ENST00000417079.1. The top five upregulated mRNAs are Q59H50, CYP27A1, DNASE1L3, GRIP2, and lnc-TMEM18-12, and the top five downregulated mRNAs are GSTM4, PODN, GLYATL2, ZNF772, and CLTC. Examination of lncRNA-mRNA interaction pairs indicated that the target gene of lncRNA XR_108954.2 is E2F2. Multiple linear regression analysis showed that XR_108954.2 (r = 0.387, p < 0.01) and E2F2 (r = 0.368, p < 0.01) expression levels were positively correlated with glucose metabolism indicators. Moreover, E2F2 was positively correlated with lipid metabolism indicators (r = 0.333, p < 0.05). The area under the ROC curve was 0.704 (95% CI: 0.578-0.830, p = 0.05) for lncRNA XR_108954.2 and 0.653 (95% CI: 0.516-0.790, p = 0.035) for E2F2.

CONCLUSIONS

This transcriptome analysis explored the aberrantly expressed lncRNAs and identified E2F2 and lncRNA XR_108954.2 as potential biomarkers for patients with T2D.

The clinical value of long noncoding RNA GAS5 in acute ischemic stroke: Correlation with disease risk, inflammation, severity, and risk of recurrence

Background

Long noncoding RNA growth arrest‐specific 5 (lnc‐GAS5) is involved in the pathophysiology of acute ischemic stroke (AIS) by regulating vascular stenosis, inflammation, and neurocyte apoptosis. This study aimed to explore the clinical value of lnc‐GAS5 in patients with AIS.

Methods

Plasma samples were collected from 120 patients with AIS at admission and 60 controls after enrollment, and lnc‐GAS5 expression in the plasma of all participants was assessed by reverse transcription quantitative polymerase chain reaction. In patients with AIS, disease severity was evaluated using National Institute of Health Stroke Scale (NIHSS) score, and plasma inflammatory cytokine levels were measured by enzyme‐linked immunosorbent assay. Recurrence‐free survival (RFS) was calculated during a 36‐month follow‐up period.

Results

Lnc‐GAS5 expression levels were higher in patients with AIS than in the controls (p < 0.001), and it had the potential to discriminate the controls from patients with AIS (area under the curve: 0.893, 95% confidence interval: 0.849–0.938). In patients with AIS, elevated lnc‐GAS5 levels were positively correlated with NIHSS score (r = 0.397, p < 0.001), diabetes mellitus (p = 0.046), and higher levels of tumor necrosis factor alpha (TNF‐α; r = 0.374, p < 0.001), interleukin‐6 (IL‐6; r = 0.223, p < 0.001), and interleukin‐17A (IL‐17A; r = 0.222, p = 0.015). The expression levels of lnc‐GAS5 were also negatively correlated with the levels of interleukin‐10 (IL‐10; r = −0.350, p < 0.001) and RFS (p = 0.036).

Conclusion

Lnc‐GAS5 is correlated with higher susceptibility to AIS, inflammation, and severity, and can predict an increased risk of AIS recurrence, indicating that monitoring of lnc‐GAS5 might improve the management of AIS.

Long noncoding RNA GAS5 in age-related diseases

Aging refers to a natural process and a universal phenomenon in all cells, tissues, organs and the whole organism. Long non-coding RNAs (lncRNAs) are non-coding RNAs with the length of 200 nucleotides. LncRNA growth arrest-specific 5 (lncRNA GAS5) is often down-regulated in cancer. The accumulation of lncRNA GAS5 has been found to be able to inhibit cancer growth, invasion and metastasis, while enhancing the sensitivity of cells to chemotherapy drugs. LncRNA GAS5 can be a signaling protein, which is specifically transcribed under different triggering conditions. Subsequently, it is involved in signal transmission in numerous pathways as a signal node. LncRNA GAS5, with a close relationship to multiple miRNAs, was suggested to be involved in the signaling pathway under three action modes (i.e., signal, bait and guidance). LncRNA GAS5 was found to be involved in different age-related diseases (e.g., rheumatoid arthritis, type 2 diabetes, atherosclerosis, osteoarthritis, osteoporosis, multiple sclerosis, cancer etc.). This study mainly summarized the regulatory effect exerted by lncRNA GAS5 on age-related diseases.

Downregulation of lncRNA EPB41L4A-AS1 Mediates Activation of MYD88-Dependent NF-κB Pathway in Diabetes-Related Inflammation

PURPOSE

Long non-coding RNAs (lncRNAs) have been shown to be involved in many human diseases. In this study, we aimed to reveal the role and molecular mechanism of lncRNA EPB41L4A-AS1 in type 2 diabetic mellitus (T2DM)-related inflammation.

METHODS

To explore the relationships between the expression of EPB41L4A-AS1 and inflammatory factors in the blood of T2DM patients, we analyzed peripheral blood mononuclear cell (PBMC) expression microarrays of T2DM patients and expression microarrays of PBMC treated with lipopolysaccharide (LPS) from the GEO database. The relationship between EPB41L4A-AS1 and phospho-p65 was explored by Western blotting (WB) and immunofluorescence. The interactions between EPB41L4A-AS1 and myeloid differentiation factor 88 (MYD88) were also verified through quantitative real-time PCR, WB, and chromatin immunoprecipitation. Glycolysis and mitochondrial stress were detected by Seahorse.

RESULTS

EPB41L4A-AS1 showed very low expression, which was significantly negatively correlated with levels of inflammatory factors in PBMCs of T2DM patients and PBMCs treated with LPS. These results were verified by cell experiments on PBMC and THP-1 cells. Knockdown of EPB41L4A-AS1 led to the phosphorylation and nuclear translocation of p65 and thus activated the NF-κB signaling pathway; it also reduced the enrichment of H3K9me3 in the MYD88 promoter and increased expression of MYD88. Overall, EPB41L4A-AS1 knockdown promoted the level of glycolysis and ultimately enhanced the inflammatory response.

CONCLUSION

EPB41L4A-AS1 knockdown activated the NF-κB signaling pathway through a MYD88-dependent regulatory mechanism, promoted glycolysis, and ultimately enhanced the inflammatory response. These results demonstrate that EPB41L4A-AS1 is closely associated with inflammation in T2DM, and that low expression of EPB41L4A-AS1 may be used as an indicator of chronic inflammation and possible diabetic vascular complications in T2DM patients.