microRNA-650 promotes inflammation induced apoptosis of intestinal epithelioid cells by targeting NLRP6

NLRP inflammasomes in health and disease

NLRP inflammasomes are a group of cytosolic multiprotein oligomer pattern recognition receptors (PRRs) involved in the recognition of pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) produced by infected cells. They regulate innate immunity by triggering a protective inflammatory response. However, despite their protective role, aberrant NLPR inflammasome activation and gain-of-function mutations in NLRP sensor proteins are involved in occurrence and enhancement of non-communicating autoimmune, auto-inflammatory, and neurodegenerative diseases. In the last few years, significant advances have been achieved in the understanding of the NLRP inflammasome physiological functions and their molecular mechanisms of activation, as well as therapeutics that target NLRP inflammasome activity in inflammatory diseases. Here, we provide the latest research progress on NLRP inflammasomes, including NLRP1, CARD8, NLRP3, NLRP6, NLRP7, NLRP2, NLRP9, NLRP10, and NLRP12 regarding their structural and assembling features, signaling transduction and molecular activation mechanisms. Importantly, we highlight the mechanisms associated with NLRP inflammasome dysregulation involved in numerous human auto-inflammatory, autoimmune, and neurodegenerative diseases. Overall, we summarize the latest discoveries in NLRP biology, their forming inflammasomes, and their role in health and diseases, and provide therapeutic strategies and perspectives for future studies about NLRP inflammasomes.

Increased miR-6132 promotes deep vein thrombosis formation by downregulating FOXP3 expression

Background

Deep vein thrombosis (DVT) is associated with aberrant gene expression that is a common peripheral vascular disease. Here, we aimed to elucidate that the epigenetic modification of forkhead box protein 3 (FOXP3) at the post-transcriptional level, which might be the key trigger leading to the down-regulation of FOXP3 expression in DVT.

Methods

In order to explore the relationship between microRNAs (miRNAs) and FOXP3, mRNA and microRNA microarray analysis were performed. Dual luciferase reporter assay was used to verify the upstream miRNAs of FOXP3. Quantitative real-time polymerase chain reaction, flow cytometry and Western blot were used to detect the relative expression of miR-6132 and FOXP3. Additionally, DVT models were established to investigate the role of miR-6132 by Murine Doppler Ultrasound and Hematoxylin-Eosin staining.

Results

Microarray and flow cytometry results showed that the FOXP3 expression was decreased while miR-6132 level was increased substantially in DVT, and there was significant negative correlation between miR-6132 and FOXP3. Moreover, we discovered that overexpressed miR-6132 reduced FOXP3 expression and aggravated DVT formation, while miR-6132 knockdown increased FOXP3 expression and alleviated DVT formation. Dual luciferase reporter assay validated the direct binding of miR-6132 to FOXP3.

Conclusion

Collectively, our data elucidate a new avenue through which up-regulated miR-6132 contributes to the formation and progression of DVT by inhibiting FOXP3 expression.

MicroRNA-mediated epigenetic regulation of inflammasomes in inflammatory responses and immunopathologies

Inflammation represents the first-line defense mechanism of the host against pathogens and cellular stress. One of the most critical inflammatory responses is characterized by the activation of inflammasomes, intracellular multiprotein complexes that induce inflammatory signaling pathways in response to various pathogen-associated molecular patterns or danger-associated molecular patterns under physiological and pathological conditions. Inflammasomes are tightly regulated in normal cells, and dysregulation of these complexes is observed in various pathological conditions, especially inflammatory diseases and cancers. Epigenetic regulation has been suggested as a key mechanism in modulating inflammasome activity, and microRNAs (miRNAs) have been implicated in the post-transcriptional regulation of inflammasomes. Therefore, miRNA-mediated epigenetic regulation of inflammasomes in pathological conditions has received considerable attention, and current strategies for targeting inflammasomes have been shown to be effective in the treatment of diseases associated with inflammasome activation. This review summarizes recent studies suggesting the roles of miRNAs in the epigenetic control of inflammasomes and highlights the potential of miRNAs as a therapeutic tool for treating human diseases.

MicroRNA-650 Regulates the Pathogenesis of Alzheimer's Disease Through Targeting Cyclin-Dependent Kinase 5

Alzheimer's disease (AD) pathogenesis feature progressive neurodegeneration, amyloid-β plaque formation, and neurofibrillary tangles. Ample evidence has indicated the involvement of epigenetic pathways in AD pathogenesis. Here, we show that the expression of microRNA 650 (miR-650) is altered in brains from AD patients. Furthermore, we found that the processing of primary miR-650 to mature miR-650 is misregulated. Bioinformatic analysis predicted that miR-650 targets the expression of three AD-associated components: Apolipoprotein E (APOE), Presenilin 1 (PSEN1), and Cyclin-Dependent Kinase 5 (CDK5), and we have experimentally confirmed that miR-650 is able to significantly reduce the expression of APOE, PSEN1, and CDK5 in vitro. Importantly, the overexpression of miR-650 was further shown to significantly alter the CDK5 level and ameliorate AD pathologies in APP-PSEN1 transgenic mice. Overall, our results indicate that miR-650 influences AD pathogenesis through regulation of CDK5.

Upregulation of miR-151-5p promotes the apoptosis of intestinal epithelial cells by targeting brain-derived neurotrophic factor in ulcerative colitis mice

Ulcerative colitis (UC) is the most prevalent form of chronic inflammatory bowel disease, the etiology of which is poorly understood. This study investigated the role of miR-151-5p on UC and explored the role of brain-derived neurotrophic factor (BDNF) in a UC mouse model and cell model. A UC mouse model was engineered by dextran sulfate sodium (DSS) induction. Primary mouse intestinal epithelial cells (IECs) were isolated. Colitis mice were intraperitoneally injected with miR-151-5p antagomir and antagomir negative control, and weight loss, disease activity index, and colon length of mice were measured. Colon tissues of mice were histologically analyzed. A UC cell model was constructed by treating MODE-K cells with DSS. miR-151-5p expression in the cell model was modulated by transfection. The exogenous BDNF effect on the UC cell model and intestinal cell apoptosis, viability and proliferation was detected by flow cytometry, CCK-8 and EdU experiment. The expression of miR-151-5p and apoptosis-related proteins was assessed through q-PCR and western blotting. miR-151-5p was upregulated in the colon tissues and primary IECs of colitis mice. miR-151-5p directly inhibited the expression of BNDF. miR-151-5p upregulation promoted apoptosis in UC MODE-K cells. miR-151-5p upregulation repressed the viability of UC MODE-K cells. Exogenous BNDF treatment reversed the effect of miR-151-5p on UC MODE-K cells. miR-151-5p knockdown improved UC symptoms in mice, including alleviating weight loss, reducing disease activity index and improving colon length and damaged colon tissues. miR-151-5p contributed to intestinal epithelial cells apoptosis in colitis mice via inhibiting BNDF expression.

Screening of ulcerative colitis biomarkers and potential pathways based on weighted gene co-expression network, machine learning and ceRNA hypothesis

BACKGROUND

Ulcerative colitis (UC) refers to an intractable intestinal inflammatory disease. Its increasing incidence rate imposes a huge burden on patients and society. The UC etiology has not been determined, so screening potential biomarkers is critical to preventing disease progression and selecting optimal therapeutic strategies more effectively.

METHODS

The microarray datasets of intestinal mucosal biopsy of UC patients were selected from the GEO database, and integrated with R language to screen differentially expressed genes and draw proteins interaction network diagrams. GO, KEGG, DO and GSEA enrichment analyses were performed to explore their biological functions. Through machine learning and WGCNA analysis, targets that can be used as UC potential biomarkers are screened out. ROC curves were drawn to verify the reliability of the results and predicted the mechanism of marker genes from the aspects of immune cell infiltration, co-expression analysis, and competitive endogenous network (ceRNA).

RESULTS

Two datasets GSE75214 and GSE87466 were integrated for screening, and a total of 107 differentially expressed genes were obtained. They were mainly related to biological functions such as humoral immune response and inflammatory response. Further screened out five marker genes, and found that they were associated with M0 macrophages, quiescent mast cells, M2 macrophages, and activated NK cells in terms of immune cell infiltration. The co-expression network found significant co-expression relationships between 54 miRNAs and 5 marker genes. According to the ceRNA hypothesis, NEAT1-miR-342-3p/miR-650-SLC6A14, NEAT1-miR-650-IRAK3, and XIST-miR-342-3p-IRAK3 axes were found as potential regulatory pathways in UC.

CONCLUSION

This study screened out five biomarkers that can be used for the diagnosis and treatment of UC, namely SLC6A14, TIMP1, IRAK3, HMGCS2, and APOBEC3B. Confirmed that they play a role in the occurrence and development of UC at the level of immune infiltration, and proposed a potential RNA regulatory pathway that controls the progression of UC.

Physiological and pathophysiological functions of NLRP6: pro- and anti-inflammatory roles

The nucleotide-binding oligomerization and leucine-rich repeat receptor (NLR) protein family consists of important immune sensors that form inflammasomes, a cytosolic multi-protein platform that induces caspase-1 activation and is involved in different inflammatory pathologies. The NLR family pyrin domain containing 6 (NLRP6) is a receptor that can signal by forming inflammasomes, but which can also play an important role without forming inflammasomes. NLRP6 regulates intestinal homeostasis and inflammation, but also is involved in cancer, the nervous system or liver diseases, with both protective and deleterious consequences. In the present article, we review the different roles of NLRP6 in these processes and offer new insights into NLRP6 activation.

This review discusses emerging roles for the NLR family pyrin domain containing 6 receptor (NLRP6) in intestinal homeostasis, inflammation, cancer, the nervous system and liver disease.

Hsa_circRNA_103124 Upregulation in Crohn's Disease Promotes Cell Proliferation and Inhibits Autophagy by Regulating the Hsa-miR-650/AKT2 Signaling Pathway

Circular RNAs (circRNAs) play important roles in the pathogenesis of Crohn's disease (CD). We discovered that hsa_circRNA_103124 was upregulated in CD patients in our previous study. Nonetheless, the function of hsa_circRNA_103124 is unclear. In this study, hsa_circRNA_103124 was predicted to interact with hsa-miR-650. Gene Ontology (GO) and pathway analyses identified AKT serine/threonine kinase 2 (AKT2) as the downstream target protein of hsa-miR-650. Activated AKT2 inhibits autophagy, but promotes cell proliferation. Recent studies suggest that the inhibition of autophagy is one of the mechanisms of CD pathogenesis. Therefore, we inferred that hsa_circRNA_103124 might regulate autophagy and proliferation by targeting AKT2 as a sponge for hsa-miR-650. Here, quantitative reverse transcription PCR (RT-QPCR) results revealed that upregulated hsa_circRNA_103124 expression in patients with CD was negatively correlated with hsa-miR-650 expression but positively correlated with the white blood cell count and calprotectin levels. TSC complex subunit 1 (TSC1), one of the proteins upstream of autophagy was downregulated in patients with CD. Consisting with the bioinformatics prediction, it was verified that hsa_circRNA_103124 targeted to hsa-miR650 by fluorescence in situ hybridization (FISH) and luciferase reporter assays. A hsa-miR-650 inhibitor reversed the promotion of rapamycin-induced autophagy and the inhibition of cell proliferation by the hsa_circRNA_103124 siRNA. However, hsa-miR-650 mimics reversed the inhibition of rapamycin-induced autophagy and the promotion of cell proliferation through hsa_circRNA_103124 overexpression. These results indicate that hsa_circRNA_103124 upregulation in patients with CD promotes cell proliferation and inhibits autophagy by regulating the hsa-miR-650/AKT2 signaling pathway.

LncRNA UCA1 Accelerates the Progression of Ulcerative Colitis via Mediating the miR-331-3p/BRD4 Axis

Background

Ulcerative colitis (UC) has become one of the fastest-growing severe diseases worldwide with high morbidity. This research aimed to explore the function of lncRNA UCA1 in UC progression.

Methods

RT-qPCR analysis was used to examine the expression of UCA1 level in colonic mucosa tissues of UC patients. Then, fetal human cells (FHCs) were stimulated by LPS to induce inflammatory injury. CCK-8, flow cytometry and ELISA were adopted to determine the influence of UCA1 depletion on cell viability, apoptosis and pro-inflammatory factors levels in LPS-induced FHCs. The interaction between UCA1 and miR-331-3p or BRD4 was confirmed by luciferase reporter assay. The expressions of key factors involved in NF-κB pathway were assessed by Western blotting.

Results

LncRNA UCA1 level was elevated in colonic mucosa tissues of UC patients. LPS stimulation restrained cell viability and promoted the apoptosis and inflammatory factors levels, thus inducing FHCs inflammatory injury, while these effects were partially abolished by UCA1 knockdown. Moreover, it was found that UCA1 silence improved LPS-triggered cell injury via miR-331-3p. In addition, BRD4 was directly targeted by miR-331-3p, and BRD4 deficiency neutralized the effects of miR-331-3p repression on LPS-triggered injury in LPS-treated FHCs.

Conclusion

Our data determined that UCA1 knockdown attenuated UC development via targeting the miR-331-3p/BRD4/NF-κB pathway.

The Short Non-Coding RNA 1251-5p Regulates Stemness Transformation and Inhibits Aggression of Lung Malignant Tumor Cells

Our study investigated the effect of short-chain non-coding RNA 1251-5p on the movement and permeation of pulmonary carcinoma stem cells. LCSC in pulmonary carcinoma cells was determined and isolated by flow cytometry. After cell transfection, qRT-PCR and immunoblotting measured the level of MiR-1251-5p, MiR-650, SLC34A2, Oct4 and CD133. Spherometric mensuration was used to assess sphericity formation situation. Transwell analyzed the movement and permeation of cells, detected the relationship among MiR-1251-5p, MiR-650 and SLC34A2 by fluorescein enzyme report gene, and the results were verified by RIP and RNA pull-down detection methods. Knock-down of MiR-1251-5p can enhance the stem cell-like characteristics of LCC, promote cell migration and invasion, upregulate the level of MiR-650, Oct4 and CD133, and downregulate the level of SLC34A2, while MiR-650 inhibitor can restore the effect of the knock-down on the hyperplasia, movement and permeation of LCSC cells. Si-Mir-1251-5p promoted stem cell like characteristics of pulmonary carcinoma cell lineage H1299 and downregulated the expression of Oct4 and CD133, and upregulated the level of SLC34A2. SLC34A2 expression was negatively correlated with MiR-650 expression and positively correlated with MiR-1251-5p in LCSC cellular tissues. MiR-1251-5p regulates LCC stem cell-like state, and inhibits the movement and permeation of pulmonary carcinoma cells via MiR-650/SLC34A2 axis.

NLRP6 inflammasome

NOD-like receptor family pyrin domain containing 6 (NLRP6) is a novel NLR family member, that shows high expression in the intestine and liver (in contrast to NLRP3 in myeloid cells), to regulate inflammation and host defense against microbes. NLRP6 is reported to involved in inflammasome activation, regulation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling, antiviral interferon (IFN) signaling, mucus secretion, and antimicrobial peptide (AMP) production. Here, we discuss the recent findings as well as debates regarding: how NLRP6 is induced ("signal I″) and activated ("signal II"); its roles in intestinal cells and immune cells; how NLRP6 and NLRP9 coordinate to regulate the anti-viral immune response in the intestine; potential targeting of NLRP6 in human diseases.