USF-1 inhibition protects against oxygen-and-glucose-deprivation-induced apoptosis via the downregulation of miR-132 in HepG2 cells

Differential expression profile of plasma exosomal microRNAs in acute type A aortic dissection with acute lung injury

MicroRNAs (miRNAs) packaged into exosomes mediate cell communication and contribute to the pathogenesis of acute type A aortic dissection (ATAAD) with acute lung injury (ALI). The expression profile of plasma exosomal miRNAs in ATAAD patients with ALI hasn’t been identified. We performed a miRNA-sequencing to analyze the differentially expressed miRNAs (DE-miRNAs) of circulating exosomes in ATAAD patients with ALI compared to patients without ALI, founding 283 specific miRNAs in two groups. We respectively selected the top 10 downregulated and upregulated DE-miRNAs for further studies. The predicted transcription factors (TFs) of these DE-miRNAs were SMAD2, SRSF1, USF1, etc. The Gene Ontology (GO) and Kyoto Encyclopedia Genes and Genomes (KEGG) analysis predicted their target genes mainly involved acute inflammatory response, cell junction, cytoskeleton, NF-κB signaling pathway, etc. Construction and analysis of the PPI network revealed that RHOA and INSR were considered hub genes with the highest connectivity degrees. Moreover, we confirmed two exosomal miRNAs (hsa-miR-485-5p and hsa-miR-206) by real-time quantitative polymerase chain reaction (RT-qPCR) in a validation cohort. Our study identified a plasma exosomal miRNAs signature related to ATAAD with ALI. Certain DE-miRNAs may contribute to the progression of this disease, which help us better understand the pathogenesis of ATAAD with ALI.

Intermittent hypoxia preconditioning protects WRL68 cells against oxidative injury: Involvement of the PINK1/Parkin-mediated mitophagy regulated by nuclear respiratory factor 1

The protective effect of intermittent hypoxia (IH) preconditioning against oxidative injury in hepatic cells was investigated and the involvement of the PINK1/Parkin-mediated mitophagy regulated by nuclear respiratory factor 1 (NRF-1) was evaluated. The results showed that IH preconditioning protected HepG2 cells against oxygen and glucose deprivation/reperfusion (OGD/Rep)-induced injury and protected WRL68 cells against H₂O₂ or AMA-induced oxidative injury. IH preconditioning up-regulated the protein level of NRF-1, PINK1, Parkin, and LC3 II, promoted the recruitment of the cytosolic Parkin, indicating the initiation of the PINK1/Parkin-mediated mitophagy in WRL68 cells. When NRF-1 was down-regulated by NRF-1 specific shRNA, the protein level of PINK1 and Parkin as well as the mitophagy level were significantly decreased. After IH preconditioning, the protein level of PINK1 and the recruitment of Parkin in CCCP-treated group were significantly higher than that of the control group, indicating the increased mitophagy capacity. And the increased mitophagy capacity induced by IH preconditioning was also reduced by down-regulation of NRF-1. Furthermore, the protective effect of IH preconditioning against H₂O₂-induced oxidative injury in WRL68 cells was inhibited when NRF-1 or PINK1 was down-regulated by specific shRNA. Mitochondrial ROS generation may be responsible for the increased expression of NRF-1 induced by IH preconditioning. In conclusion, the PINK1/Parkin-mediated mitophagy regulated by NRF-1 was involved in IH preconditioning-induced protective effect against oxidative cellular injury in hepatic cells.

bFGF promotes neurological recovery from neonatal hypoxic-ischemic encephalopathy by IL-1β signaling pathway-mediated axon regeneration

INTRODUCTION

Neonatal hypoxia-ischemic brain damage (HIBD) can lead to serious neuron damage and dysfunction, causing a significant worldwide health problem. bFGF as a protective reagent promotes neuron repair under hypoxia/ischemia (HI). However, how bFGF and downstream molecules were regulated in HI remains elusive.

METHODS

We established an in vitro HI model by culturing primary cortical neurons and treated with oxygen-glucose deprivation (OGD). We suppressed the expression of bFGF by using siRNA (small interfering RNA) interference to detect the neuronal morphological changes by immunofluorescence staining. To determine the potential mechanisms regulated by bFGF, the change of downstream molecular including IL-1β was examined in bFGF knockdown condition. IL-1β knockout (KO) rats were generated using CRISPR/Cas9-mediated technologies. We used an accepted rat model of HI, to assess the effect of IL-1β deletion on disease outcomes and carried out analysis on the behavior, histological, cellular, and molecular level.

RESULTS

We identified that OGD can induce endogenous expression of bFGF. Both OGD and knockdown of bFGF resulted in reduction of neuron numbers, enlarged cell body and shortened axon length. We found molecules closely related to bFGF, such as interleukin-1β (IL-1β). IL-1β was up-regulated after bFGF interference under OGD conditions, suggesting complex signaling between bFGF and OGD-mediated pathways. We found HI resulted in up-regulation of IL-1β mRNA in cortex and hippocampus. IL-1β KO rats markedly attenuated the impairment of long-term learning and memory induced by HI. Meanwhile, IL-1β^-/- (KO, homozygous) group showed better neurite growth and less apoptosis in OGD model. Furthermore, serine/threonine protein kinase (AKT1) mRNA and protein expression was significantly up-regulated in IL-1β KO rats.

CONCLUSIONS

We showed that IL-1β-mediated axon regeneration underlie the mechanism of bFGF for the treatment of HIBD in neonatal rats. Results from this study would provide insights and molecular basis for future therapeutics in treating HIBD.

Differential Expression of Long Noncoding RNAs and Their Function-Related mRNAs in the Peripheral Blood of Allergic Rhinitis Patients

BACKGROUND

The mechanism of long noncoding RNAs (lncRNAs) involved in the development of allergic rhinitis (AR) remains unclear.

OBJECTIVE

We investigated the mechanism by which differentially expressed lncRNAs contribute to pathogenesis of AR.

METHODS

Expression profiles of lncRNAs and mRNAs were analyzed by microarray detection from the blood samples of 3 AR patients and 3 control subjects, and the main lncRNAs were verified by quantitative real-time polymerase chain reaction (qRT-PCR) in the peripheral blood of 16 AR patients and 18 control subjects. GO (Gene_Ontology), Pathway, and Disease analysis of differentially expressed lncRNAs and mRNAs, and transcription factor prediction analysis were performed to explore synergistic effect of differentially expressed lncRNAs and their function-related mRNAs on AR pathogenesis.

RESULTS

Thirty-one lncRNAs were differentially expressed in the peripheral blood from AR patients, and 4 of the 5 most differentially expressed lncRNAs had significantly higher levels in AR patients than in control subjects by qRT-PCR analysis. A lncRNA-mRNA coexpression network analysis identified 16 pairs of positive correlations between the 4 lncRNAs and coexpressed mRNAs. GO, Pathway, and Disease analyses indicated that the 4 lncRNAs were correlated with 7 mRNAs enriched in terms of inflammation, immune response, and allergic diseases. Transcription factor prediction results suggested that Oct-1, AP-1, NF-kappaB, and c-Rel play key roles in the pathogenesis of AR mediated by lncRNAs.

CONCLUSION

Our results provide new insights into how lncRNAs and their function-related mRNAs might contribute to AR.

The Role of HOTAIR/miR-148b-3p/USF1 on Regulating the Permeability of BTB

Homeobox transcript antisense intergenic RNA (HOTAIR), as a long non-coding RNA (lncRNA), has been considered to play critical roles in the biological properties of various tumors. The purposes of this study were to investigate the role and possible molecular mechanisms of HOTAIR in regulating the permeability of blood tumor barrier (BTB) in vitro. Our present study elucidated that the expressions of HOTAIR and upstream stimulatory factor 1 (USF1) was up-regulated, but miR-148b-3p was down-regulated in glioma microvascular endothelial cells (GECs). Knockdown of HOTAIR could increase the permeability of BTB as well as down-regulated the expressions of tight junction related proteins ZO-1, occludin, claudin-5, but up-regulated miR-148b-3p expressions in GECs. Meanwhile, dual-luciferase reporter assays demonstrated that HOTAIR was a target RNA of miR-148b-3p. Furthermore, overexpression of miR-148b-3p increased the permeability of BTB by down-regulating the expressions of tight junction related proteins and USF1 in GECs, and vice versa. And further result revealed USF1 was a target of miR-148b-3p. Silence of USF1 increased the permeability of BTB duo to their interaction with the promoters of ZO-1, occludin, and claudin-5 in GECs. Taken together, our finding indicated that knockdown of HOTAIR increased BTB permeability via binding to miR-148b-3p, which further reducing tight junction related proteins in GECs by targeting USF1. Thus, HOTAIR will attract more attention since it can serve as a potential target of drug delivery across BTB and may provide novel strategies for glioma treatment.

MiR-101 reverses the hypomethylation of the LMO3 promoter in glioma cells

LIM-only protein 3 (LMO3), a member of the LIM-only protein group, is a new DNA methylation gene that was identified in gliomas via the MeDIP-Chip in our previous study. In this study, we found that LIM-only protein 3 (LMO3) is hypomethylated and overexpressed in glioma cells and tissues. The overexpression of LMO3 was correlated with a poor prognosis in glioma patients, and LMO3 was indirectly inhibited by the tumor suppressor miR-101, which is a potential prognosis marker of gliomas. MiR-101 decreased the expression of LMO3 by reversing the methylation status of the LMO3 promoter and by inhibiting the presence of the methylation-related histones H3K4me2 and H3K27me3 and increasing the presence of H3K9me3 and H4K20me3 on the promoter. It was determined that miR-101 decreases the occupancy of H3K27me3 by inhibiting EZH2, DNMT3A and EED and decreases the H3K9me3 occupancy on the LMO3 promoter via SUV39H1, SUV39H2, G9a and PHF8. Furthermore, miR-101 suppresses the expression of LMO3 by decreasing USF and MZF1.