The interaction between ANXA2 and lncRNA Fendrr promotes cell apoptosis in caerulein-induced acute pancreatitis

SOX6 AU controls myogenesis by cis-modulation of SOX6 in cattle

Long non-coding RNAs (lncRNAs) have been shown to be involved in the regulation of skeletal muscle development through multiple mechanisms. The present study revealed that the lncRNA SOX6 AU (SRY-box transcription factor 6 antisense upstream) is reverse transcribed from upstream of the bovine sex-determining region Y (SRY)-related high-mobility-group box 6 (SOX6) gene. SOX6 AU was significantly differentially expressed in muscle tissue among different developmental stages in Xianan cattle. Subsequently, knockdown and overexpression experiments discovered that SOX6 AU promoted primary skeletal muscle cells proliferation, apoptosis, and differentiation in bovine. The overexpression of SOX6 AU in bovine primary skeletal muscle cells resulted in 483 differentially expressed genes (DEGs), including 224 upregulated DEGs and 259 downregulated DEGs. GO functional annotation analysis showed that muscle development-related biological processes such as muscle structure development and muscle cell proliferation were significantly enriched. KEGG pathway analysis revealed that the PI3K/AKT and MAPK signaling pathways were important pathways for DEG enrichment. Notably, we found that SOX6 AU inhibited the mRNA and protein expression levels of the SOX6 gene. Moreover, knockdown of the SOX6 gene promoted the proliferation and apoptosis of bovine primary skeletal muscle cells. Finally, we showed that SOX6 AU promoted the proliferation and apoptosis of bovine primary skeletal muscle cells by cis-modulation of SOX6 in cattle. This work illustrates our discovery of the molecular mechanisms underlying the regulation of SOX6 AU in the development of beef.

LncNFYB promotes the proliferation of rheumatoid arthritis fibroblast-like synoviocytes via LncNFYB/ANXA2/ERK1/2 axis

Long noncoding RNAs (lncRNAs) are specifically expressed in different diseases and regulate disease progression. To explore the functions of rheumatoid arthritis (RA)-specific lncRNA, we determined the lncRNA expression profile of fibroblast-like synoviocytes (FLS) obtained from patients with RA and osteoarthritis (OA) using a LncRNA microarray and identified up-regulated LncNFYB in RA as a potential therapeutic target. Using gain- and loss-of-function studies, LncNFYB was proven to promote FLS proliferation and cell cycle progress but not affect their invasion, migration, and apoptotic abilities. Further investigation discovered that LncRNA could combine with annexin A2 (ANXA2) and enhance the level of phospho-ANXA2 (Tyr24) in the plasma membrane area, which induced the activation of ERK1/2 to promote proliferation. These findings provide new insights into the biological functions of LncNFYB on modification of FLS, which may be exploited for the therapy of RA.

Long non-coding RNAs and pancreatic cancer: A multifaceted view

Pancreatic cancer (PC) is a highly malignant disease with a 5-year survival rate of only 10%. Families with PC are at greater risk, as are type 2 diabetes, pancreatitis, and other factors. Insufficient early detection methods make this cancer have a poor prognosis. Additionally, the molecular mechanisms underlying PC development remain unclear. Increasing evidence suggests that long non-coding RNAs (lncRNAs) contribute to PC pathology,which may control gene expression by recruiting histone modification complexes to chromatin and interacting with proteins and RNAs. In recent studies, abnormal regulation of lncRNAs has been implicated in PC proliferation, metastasis, invasion, angiogenesis, apoptosis, and chemotherapy resistance suggesting potential clinical implications. The paper reviews the progress of lncRNA research in PC about diabetes mellitus, pancreatitis, cancer metastasis, tumor microenvironment regulation, and chemoresistance. Furthermore, lncRNAs may serve as potential therapeutic targets and biomarkers for PC diagnosis and prognosis. This will help improve PC patients' survival rate from a lncRNA perspective.

Role of lncRNAs in acute pancreatitis: pathogenesis, diagnosis, and therapy

Acute pancreatitis (AP) is one of the most common acute abdominal diseases characterized by an injury and inflammatory disorder of the pancreas with complicated pathological mechanisms. Long non-coding RNAs (lncRNAs) have been shown to play an important role in various physiological and pathological processes in humans, and they have emerged as potential biomarkers of diagnosis and therapeutic targets in various diseases. Recently, accumulating evidence has shown significant alterations in the expression of lncRNAs, which are involved in the pathogenesis of AP, such as premature trypsinogen activation, impaired autophagy, inflammatory response, and acinar cell death. Moreover, lncRNAs can be the direct target of AP treatment and show potential as biomarkers for the diagnosis. Thus, in this review, we focus on the role of lncRNAs in the pathogenesis, diagnosis, and therapy of AP and emphasize the future directions to study lncRNAs in AP, providing new insight into understanding the cellular and molecular mechanisms of AP and seeking novel biomarkers for the diagnosis and therapeutic targets to improve clinical management in the future.

Nonalcoholic Fatty Liver Hepatocyte-Derived lncRNA MALAT1 Aggravates Pancreatic Cell Inflammation via the Inhibition of Autophagy by Upregulating YAP

Background

Acute pancreatitis (AP) is one of the most common gastrointestinal disorders, which causes death with a high mortality rate of about 30%. The study aims to identify whether the nonalcoholic fatty liver disease (NAFLD)-derived lncRNA MALAT1 participates in the inflammation of pancreatic cell and its potential mechanism.

Methods

The NAFLD cell model was constructed by treating HepG2 cells with FFA. The in vitro model of acute pancreatitis (AP) was established by the administration of caerulein on AR42J cells. MALAT1 and si-MALAT1 were transfected into pancreatic cells, and then exosomes were collected from the NAFLD cell model and then were cocultured with AR42J cells. Transmission electron microscopy was used to observe the morphology of exosomes. Oil Red O staining was applied to reveal the lipid deposition. The triglyceride, IL-6, and TNF-α levels were detected using ELISA. The MALAT1 level in exosomes was detected by qRT-PCR. The CD9, CD63, CD81, and CYP2E1, LC3II, and LC3I levels were detected by western blot.

Results

MALAT1 was upregulated in NAFLD-derived exosomes and increased the levels of IL-6 and TNF-α in pancreatic cells. NAFLD-derived exosomes inhibited YAP phosphorylation, decreased the levels of IL-6 and TNF-α, and reduced the ratio of LC3II/LC3I protein in pancreatic cells. Silencing MALAT1 significantly returned the inhibitory effect of NAFLD on hippo-YAP pathway. YAP1 signal transduction inhibitor CA3 reversed the decrease of LC3II/LC3I expression and the increase of IL-6 and TNF-α levels induced by MALAT1 in the AP cell model.

Conclusions

NAFLD-derived MALAT1 exacerbates pancreatic cell inflammation via inhibiting autophagy by upregulating YAP.

Inhibition of ANXA2 regulated by SRF attenuates the development of severe acute pancreatitis by inhibiting the NF-κB signaling pathway

BACKGROUND

Acute pancreatitis (AP) is an inflammatory process of the pancreas resulting from biliary obstruction or alcohol consumption. Approximately, 10-20% of AP can evolve into severe AP (SAP). In this study, we sought to explore the physiological roles of the transcription factor serum response factor (SRF), annexin A2 (ANXA2), and nuclear factor-kappaB (NF-κB) in SAP.

METHODS

C57BL/6 mice and rat pancreatic acinar cells (AR42J) were used to establish an AP model in vivo and in vitro by cerulein with or without lipopolysaccharide (LPS). Production of pro-inflammatory cytokines (IL-1β and TNF-α) were examined by ELISA and immunoblotting analysis. Hematoxylin and eosin (HE) staining and TUNEL staining were performed to evaluate pathological changes in the course of AP. Apoptosis was examined by flow cytometric and immunoblotting analysis. Molecular interactions were tested by dual luciferase reporter, ChIP, and Co-IP assays.

RESULTS

ANXA2 was overexpressed in AP and correlated to the severity of AP. ANXA2 knockdown rescued pancreatic acinar cells against inflammation and apoptosis induced by cerulein with or without LPS. Mechanistic investigations revealed that SRF bound with the ANXA2 promoter region and repressed its expression. ANXA2 could activate the NF-κB signaling pathway by inducing the nuclear translocation of p50. SRF-mediated transcriptional repression of ANXA2-protected pancreatic acinar cells against AP-like injury through repressing the NF-κB signaling pathway.

CONCLUSION

Our study highlighted a regulatory network consisting of SRF, ANXA2, and NF-κB that was involved in AP progression, possibly providing some novel targets for treating SAP.

Downregulation of lncRNA NEAT1 Relieves Caerulein-Induced Cell Apoptosis and Inflammatory Injury in AR42J Cells Through Sponging miR-365a-3p in Acute Pancreatitis

Mounting evidence suggests that long non-coding RNAs (lncRNAs) and microRNAs exert a critical regulatory role in acute pancreatitis. The present study aimed to explore the role of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in acute pancreatitis (AP) that was induced by caerulein in rat pancreatic acinar cells (AR42J). The potential target sites of lncRNA NEAT1 and miR-365a-3p were predicted using starBase and were confirmed using dual-luciferase reporter assay. Reverse transcription-quantitative polymerase chain reaction was performed to assess lncRNA NEAT1 and miR-365a-3p expression levels in AP induced by caerulein. Cell Counting Kit-8 and flow cytometry assays were performed to assess AR42J cell viability. Western blotting was performed to evaluate the expression of apoptosis-related proteins. Interleukin (IL)-1β, IL-6, and tumor necrosis factor-α levels were detected by ELISA. The results of the dual-luciferase reporter assay confirmed that miR-365a-3p could bind to NEAT1. LncRNA NEAT1 was upregulated in AR42J cells treated with 10 nmol/l caerulein, and miR-365a-3p was expressed at low levels in an AP model. Overexpression of miR-365a-3p suppressed the apoptosis and inflammatory response of AR42J cells induced by caerulein. Importantly, inhibition of lncRNA NEAT1 decreased apoptosis and inflammation in caerulein-treated AR42J cells, while these effects were reverted upon co-transfection with a miR-365a-3p inhibitor. In conclusion, lncRNA NEAT1 was involved in AP progression by sponging miR-365a-3p and may thus be a novel target for treating patients with AP.

LncRNA FENDRR Servers as a Possible Marker of Essential Hypertension and Regulates Human Umbilical Vein Endothelial Cells Dysfunction via miR-423-5p/Nox4 Axis

Purpose

Essential hypertension (EH) is an intricate non-communicable infirmity and lncRNAs are validated as essential mediators in EH. The study aimed to propose the expression pattern of FENDRR and miR-423-5p, substantiate the potential mechanism of FENDRR/miR-423-5p/Nox4 axis in EH.

Patients and Methods

The expression of FENDRR and miR-423-5p was evaluated by qRT-PCR and the clinical significance was explored by the ROC curve. Pearson correlation indicated the relationship between FENDRR and miR-423-5p. The function of FENDRR and miR-423-5p on HUVECs was clarified by CCK-8 assay, Transwell assay, and flow cytometry. Western blot was used to assess the relative protein expression of Nox4.

Results

FENDRR was highly expressed and miR-423-5p was lowly expressed in EH patients and a negative correlation between them was determined. FENDRR might serve as a predictive diagnosis in differentiating EH patients. Knockdown of FENDRR or overexpression of miR-423-5p showed expansionary effects in cell proliferation, cell migration, and inhibiting cell apoptosis. Meanwhile, miR-423-5p was determined as a target of FENDRR and mediated the function of FENDRR on HUVECs. Moreover, Nox4 is a down-streaming target gene of miR-423-5p. The protein expression of Nox4 was regulated by the alternation of miR-423-5p expression.

Conclusion

FENDRR played an energetic role in EH and contributed to HUVECs dysfunction by restricting cell proliferation, suppressing cell migration, and accelerating cell apoptosis by manipulating the miR-423-5p/Nox4 axis.

Prognostic and Predicted Significance of FENDRR in Colon and Rectum Adenocarcinoma

Background

The role of fetal-lethal non-coding developmental regulatory RNA (FENDRR) has been explored in various cancers; however, its relationship with colon adenocarcinoma/rectum adenocarcinoma (COAD/READ) remains unclear. The objectives of this study were to identify and assess any associations between FENDRR and COAD/READ using The Cancer Genome Atlas (TCGA) database and the Genetic Data Commons (GDC) Data Portal.

Methods

The records of patients with COAD/READ were collected from the GDC Data Portal. After comparing the expression level of FENDRR in COAD/READ and healthy tissues, we evaluated the association of FENDRR with clinicopathological characters and the survival rate, the impact of FENDRR on prognosis, the biological function of FENDRR, and the relative abundance of tumor-infiltrating immune cells in patients with COAD/READ. Moreover, we aimed to construct a protein-protein interaction (PPI) network for selecting genes and a ceRNA network for presenting mRNA-miRNA-lncRNA interactions.

Results

In patients with COAD/READ, FENDRR expression could differentiate tumor tissues from the adjacent healthy tissues since it was significantly lower in the former than in the latter. High FENDRR expression was correlated with poorer survival and higher tumor stage, current tumor stage, and metastasis stage, and also exhibited high scores for apoptosis, autophagy, and senescence. Immune cell infiltration analysis showed that the high expression group had significantly lower immune and stromal scores. Low FENDRR expression was correlated with poor overall survival (OS), and thus, it could serve as an independent risk factor. The prognostic models constructed in the study performed well for the prediction of OS and disease-specific survival (DFS) using FENDRR expression. Gene set enrichment analysis revealed that vascular smooth muscle contraction, melanogenesis, basal cell carcinoma, and Hedgehog signaling pathways were significantly enriched in patients with high FENDRR expression. Eight hub genes, namely, PKM, ALDOA, PFKP, ALDOC, PYGL, CTNNB1, PSMA5, and WNT5A, were selected from the PPI network, and a ceRNA network was constructed based on the differentially expressed mRNAs, miRNAs, and lncRNAs to illustrate their regulatory relationships.

Conclusion

FENDRR may serve as a potential biomarker for the diagnosis and prognosis of COAD/READ.

LncRNA FENDRR promotes apoptosis of Leydig cells in late-onset hypogonadism by facilitating the degradation of Nrf2

This study aimed to investigate the role of lncRNA FENDRR in apoptosis of Leydig cells and the further mechanism. The apoptosis of Leydig cells (TM3 cell line) was induced by H₂O₂-treatment and detected by flow cytometry. The function of FENDRR was determined by in vitro and in vivo silencing experiments. The mechanism of FENDRR in regulating the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) was assessed by RNA immunoprecipitation, RNA pull-down, and ubiquitination assays. FENDRR expression was up-regulated in H₂O₂-treated TM3 cells. Knockdown of FENDRR augmented Nrf2 and HO-1 protein levels and testosterone production in H₂O₂-treated TM3 cells, whereas the apoptosis rate and caspase 3 activity were decreased. Mechanically, FENDRR bound to Nrf2 and promoted its ubiquitination and degradation. Nrf2 overexpression reversed the effects FENDRR overexpression on apoptosis, caspase 3 activity, and testosterone concentration in H₂O₂-treated TM3 cells. The in vivo experiments showed that FENDRR silence increased serum testosterone level and improved testosterone-related anti-depression behaviors of late-onset hypogonadism (LOH) mice. Our findings suggested that FENDRR could promote apoptosis of Leydig cells in LOH partly through facilitating Nrf2 degradation.

Long Non-coding RNA FENDRR Modulates Autophagy Through Epigenetic Suppression of ATG7 via Binding PRC2 in Acute Pancreatitis

Acute pancreatitis (AP) is an inflammatory, complicated pancreatic disease, carrying significant morbidity and mortality. However, the molecular and cellular mechanisms involved in AP pathogenesis remain to be elucidated. Here, we explore the role of FOXF1 adjacent non-coding developmental regulatory RNA (FENDRR) in AP progression. Caerulein with or without LPS- induced or taurolithocholic acid 3-sulfate (TLC-S)-induced AP mouse models and cell models were performed for the validation of FENDRR expression in vivo and in vitro, respectively. Histopathological examinations of pancreatic tissues were performed to evaluate the severity of AP. Transmission electron microscopy was utilized to visualize the autophagic vacuoles. siRNA specifically targeting FENDRR was further applied. Flow cytometry was employed to assess cell apoptosis. ELISA, immunoflureoscence, and western blotting analysis were also performed to determine the levels of inflammatory cytokines and autophagy activity. RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP) assays were carried out to reveal the epigenetic regulation of FENDRR on ATG7. Additionally, silencing FENDRR was also verified in AP mouse models. Higher FENDRR and impaired autophagy were displayed in both AP mouse models and cell models. FENDRR knockdown dramatically attenuated caerulein- or TLC-S-induced AR42J cells apoptosis and autophagy suppression. Further mechanistic experiments implied that the action of FENDRR is moderately attributable to its repression of ATG7 via direct interaction with the epigenetic repressor PRC2. Moreover, the silencing of FENDRR significantly induced the promotion of ATG7, thus alleviating the development of AP in vivo. Our study highlights FENDRR as a novel target that may contribute to AP progression, suggesting a therapeutic target for AP treatment.

miR-9 alleviated the inflammatory response and apoptosis in caerulein-induced acute pancreatitis by regulating FGF10 and the NF-κB signaling pathway

MicroRNAs (miRs) have been implicated in the development of acute pancreatitis (AP). However, the role and potential mechanism of miR-9 in AP progression remains unclear. Caerulein-treated AR42J cells were used as a cellular model of AP. Results revealed caerulein triggered an inflammatory response by promoting the secretion of inflammatory cytokines [tumor necrosis factor-α, interleukin (IL) 1β and IL-6], as evidenced by ELISA. Furthermore, caerulein-induced apoptosis was reported by flow cytometry and western blot assays. Additionally, miR-9 expression was downregulated by caerulein treatment, as demonstrated by reverse transcription quantitative PCR. However, miR-9 overexpression reduced the inflammatory response and apoptosis in caerulein-treated AR42J cells. miR-9 knockdown resulted in opposite effects. Furthermore, fibroblast growth factor (FGF) 10 was validated to be targeted via miR-9 by luciferase, RNA immunoprecipitation and RNA pull-down assays. Results demonstrated increased FGF10 expression in caerulein-treated AR42J cells and that FGF10 overexpression exacerbated the caerulein-induced inflammatory response and apoptosis, while its knockdown had the opposite effect. Additionally, FGF10 reversed the effect of miR-9 on caerulein-induced injury in AR42J cells. Results demonstrated that miR-9 inhibited the expression of the nuclear factor κB (NF-κB) pathway-related proteins by downregulating FGF10. As a result, miR-9 decreased inflammatory response and apoptosis in caerulein-treated AR42J cells by targeting FGF10 and blocking NF-κB signaling, suggesting that miR-9 may serve as a novel target for AP treatment.

MiR-146b-3p protects against AR42J cell injury in cerulein-induced acute pancreatitis model through targeting Anxa2

Background

Acute pancreatitis (AP) is a common inflammatory disorder. MicroRNAs play crucial roles in the pathogenesis of AP. In this article, we explored the detailed role and molecular mechanisms of miR-146b-3p in AP progression.

Methods

The rat AR42J cells were treated with cerulein to establish the AP model in vitro. The miR-146b-3p and Annexin A2 (Anxa2) mRNA levels were assessed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were tested using the Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. Caspase-3 activity and the production of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay and qRT-PCR. Targeted interaction between miR-146b-3p and Anxa2 was verified by the dual-luciferase reporter and RNA immunoprecipitation assays. Western blot analysis was performed to detect the expression of Anxa2 protein.

Results

Our data revealed that miR-146b-3p was significantly downregulated in AP samples. The enforced expression of miR-146b-3p alleviated cerulein-induced injury in AR42J cells, as evidenced by the promotion in cell viability and the repression in cell apoptosis, as well as the reduction in IL-1β, IL-6, and TNF-α production. Anxa2 was directly targeted and inhibited by miR-146b-3p. Moreover, the alleviative effect of miR-146b-3p overexpression on cerulein-induced AR42J cell injury was mediated by Anxa2.

Conclusions

The current work had led to the identification of miR-146b-3p overexpression that protected against cerulein-induced injury in AR42J cells at least in part by targeting Anxa2, revealing a promising target for AP diagnosis and treatment.

Long Non-Coding RNA FENDRR: Gene Structure, Expression, and Biological Relevance

The FOXF1 Adjacent Noncoding Developmental Regulatory RNA (Fendrr) plays an important role in the control of gene expression in mammals. It is transcribed in the opposite direction to the neighboring Foxf1 gene with which it shares a region containing promoters. In humans, FENDRR is located on chromosome 16q24.1, and is positively regulated both by the FOXF1 distant lung-specific cis-acting enhancer and by trans-acting FOXF1. Fendrr has been shown to function as a competing endogenous RNA, sponging microRNAs and protein factors that control stability of mRNAs, and as an epigenetic modifier of chromatin structure around gene promoters and other regulatory sites, targeting them with histone methyltrasferase complexes. In mice, Fendrr is essential for development of the heart, lungs, and gastrointestinal system; its homozygous loss causes embryonic or perinatal lethality. Importantly, deregulation of FENDRR expression has been causatively linked also to tumorigenesis, resistance to chemotherapy, fibrosis, and inflammatory diseases. Here, we review the current knowledge on the FENDRR structure, expression, and involvement in development and tissue maintenance.

LncRNA MEG3 Participates in Caerulein-Induced Inflammatory Injury in Human Pancreatic Cells via Regulating miR-195-5p/FGFR2 Axis and Inactivating NF-κB Pathway

Acute pancreatitis (AP) is a dysfunctional pancreas disease marked by severe inflammation. Long non-coding RNAs (lncRNAs) involving in the regulation of inflammatory responses have been frequently mentioned. The purpose of this study was to ensure the function and action mode of lncRNA maternally expressed gene 3 (MEG3) in caerulein-induced AP cell model. HPDE cells were treated with caerulein to establish an AP model in vitro. The expression of MEG3, miR-195-5p, and fibroblast growth factor receptor 2 (FGFR2) was measured using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation and apoptosis were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry assay, respectively. The expression of CyclinD1, B cell lymphoma/leukemia-2 (Bcl-2), Bcl-2-associated X protein (Bax), FGFR2, P65, phosphorylated P65 (p-P65), alpha inhibitor of nuclear factor kappa beta (NF-κB) (IκB-α), and phosphorylated IκB-α (p-IκB-α) at the protein level was quantified by western blot. The concentrations of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were monitored by enzyme-linked immunosorbent assay (ELISA). The targeted relationship between miR-195-5p and MEG3 or FGFR2 was forecasted by the online software starBase v2.0 and verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. As a result, the expression of MEG3 and FGFR2 was decreased in caerulein-induced HPDE cells, while the expression of miR-195-5p was increased. MEG3 overexpression inhibited cell apoptosis and inflammatory responses that were induced by caerulein. Mechanically, miR-195-5p was targeted by MEG3 and abolished the effects of MEG3 overexpression. FGFR2 was a target of miR-195-5p, and MEG3 regulated the expression of FGFR2 by sponging miR-195-5p. FGFR2 overexpression abolished miR-195-5p enrichment-aggravated inflammatory injuries. Moreover, the NF-κB signaling pathway was involved in the MEG3/miR-195-5p/FGFR2 axis. Collectively, MEG3 participates in caerulein-induced inflammatory injuries by targeting the miR-195-5p/FGFR2 regulatory axis via mediating the NF-κB pathway in HPDE cells.

Effects of Egr1 on pancreatic acinar intracellular trypsinogen activation and the associated ceRNA network

Acute pancreatitis (AP) is a common digestive disorder with high morbidity and mortality. The present study aimed to investigate the expression of early growth response protein 1 (Egr1), and the effect of competing endogenous (ce)RNA network on trypsinogen activation. Pancreatic acinar intracellular trypsinogen activation (PAITA) is an important event in the early stage of AP; however, the underlying mechanisms remain unclear. The present study used taurolithocholic acid 3-sulfate (TLC-S)-treated AR42J cells (pancreatic cell line) to establish a PAITA model. A gene microarray and bioinformatics analysis was performed to identify the potential key targets in PAITA. The results demonstrated that Egr1, an important transcription factor, was significantly overexpressed in PAITA. In Egr1 small interfering (si)RNA-transfected cells, Egr1 expression was decreased and trypsinogen activation was significantly decreased compared with negative control siRNA-transfected cells, indicating that in TLC-S-induced PAITA, overexpression of Egr1 enhanced trypsinogen activation. A ceRNA network [mRNA-microRNA (miRNA/miR)-long non-coding (lnc)RNA] generated using the PAITA model revealed that the effects of Egr1 on PAITA may be regulated by multiple ceRNA pairs, and the lncRNAs (including NONRATT022624 and NONRATT031002) and miRNAs [including Rattus norvegicus (rno)-miR-214-3p and rno-miR-764-5p] included in the ceRNA pairs may serve roles in PAITA by regulating the expression of Egr1. The results of the present study may provide novel targets for researching the underlying mechanisms of, and developing treatments for AP.

Interference of Hsa_circ_0003928 Alleviates High Glucose-Induced Cell Apoptosis and Inflammation in HK-2 Cells via miR-151-3p/Anxa2

BACKGROUND

Diabetic nephropathy (DN) is a severe end-stage kidney disease developed from diabetes mellitus. The involvement of circular RNA (circRNAs) in the regulation of DN pathogenesis has been implied, but the underlying mechanism of DN is still lacking. This study aimed to investigate the effect of hsa_circ_0003928 on the inflammation and apoptosis of high glucose (HG)-induced renal tubular cells.

METHODS

The expression of hsa_circ_0003928, miR-151-3p and Anxa2 in blood samples from DN patients and healthy controls was detected by RT-qPCR. Human renal epithelial cells HK-2 were incubated with D-glucose (30 mmol/l) to establish DN model in vitro. RT-qPCR analysis confirmed the transfection effects and detected the expressions of TNF-α, IL-6 and IL-1β. Western blotting analysis determined the protein expression of Anxa2, Bcl-2, Bax, cleaved caspase-3 and caspase-3. The production of ROS was detected by DCF-DA method and production of inflammatory cytokines was verified by ELISA assay. CCK-8 assay and TUNEL assay were performed to determine cell viability and apoptosis, respectively. Dual-luciferase reporter assay was performed to confirm the relationship between miR-151-3p and hsa_circ_0003928 or Anxa2.

RESULTS

Hsa_circ_0003928 and Anxa2 mRNA levels were increased, whereas miR-151-3p was decreased in both HG-induced HK-2 cells and patients with DN. Hsa_circ_0003928 knockdown could decrease cell viability loss and apoptosis, increase Bcl-2 expression, and decrease Bax and cleaved caspase-3 expression. Besides, hsa_circ_0003928 knockdown suppressed HG-induced overproduction of ROS, TNF-α, IL-6 and IL-1β. However, the effects made by miR-151-3p inhibition were opposite to those made by hsa_circ_0003928 knockdown. Furthermore, the binding sites between miR-151-3p and hsa_circ_0003928 or Anxa2 were predicted and verified. Protein expression of Anxa2 was suppressed by hsa_circ_0003928 knockdown, which was rescued by miR-151-3p inhibition.

CONCLUSION

These results demonstrated that hsa_circ_0003928 could act as a sponge of miR-151-3p and regulate HG-induced inflammation and apoptosis partly through regulating Anxa2.

Predictive value of long non-coding RNA intersectin 1-2 for occurrence and in-hospital mortality of severe acute pancreatitis

Background

This study aimed to investigate the predictive value of long non‐coding RNA intersectin 1‐2 (lnc‐ITSN1‐2) for severe acute pancreatitis (SAP) risk, and its correlation with disease severity and in‐hospital mortality in SAP patients.

Methods

Plasma samples from 60 SAP, 60 moderate‐severe acute pancreatitis (MSAP) and 60 mild acute pancreatitis (MAP) patients were collected within 24 hours, and plasma samples from 60 age and gender‐matched healthy controls (HCs) were collected when enrollment. Lnc‐ITSN1‐2 was detected by reverse transcription‐quantitative polymerase chain reaction. In AP patients, disease severity was evaluated and in‐hospital deaths were recorded.

Results

Lnc‐ITSN1‐2 was increased in SAP patients compared with MSAP, MAP patients, and HCs, and it is well‐discriminated SAP patients from MSAP patients (area under curve (AUC): 0.699, 95% confidence interval (CI): 0.605‐0.792), MAP patients (AUC: 0.862, 95% CI: 0.798‐0.926), and HCs (AUC: 0.958, 95% CI: 0.925‐0.990). For disease severity, lnc‐ITSN1‐2 was positively correlated with Ranson's score, acute pathologic and chronic health evaluation (APACHE) II score, sequential organ failure assessment (SOFA) score, and C‐reactive protein (CRP) in SAP patients, MSAP patients, and MAP patients; meanwhile, the correlation coefficients were highest in SAP patients. Furthermore, lnc‐ITSN1‐2 displayed a good predictive value for increased in‐hospital mortality in SAP (AUC: 0.803, 95% CI: 0.673‐0.933) and MSAP (AUC: 0.854, 95% CI: 0.752‐0.956) patients, which was similar with several common prognostic factors (including Ranson's score, APACHE II score, SOFA score, and CRP).

Conclusion

Lnc‐ITSN1‐2 might be a potential biomarker for discrimination of SAP to improve the prognosis of SAP patients.

The pivotal role and mechanism of long non-coding RNA B3GALT5-AS1 in the diagnosis of acute pancreatitis

The present study planned to dig the potential impacts of long non-coding RNA B3GALT5-AS1 in acute pancreatitis (AP). A total of 66 patients who were diagnosed with AP using ultrasonic imaging were enrolled in the study. Expression levels of B3GALT5-AS1 in the serum of AP patients were determined. Afterwards, rat pancreatic AR42J acinar cells were disposed with caerulein to produce AP-like injury. The role and molecular mechanisms of B3GALT5-AS1 in AP were explored through in vitro cell experiments. The levels of lncRNA B3GALT5-AS1 were observed to be lessened in patients with AP relative to healthy controls. In addition, caerulein was observed to induce injuries in the AR42J cells (depressed cell viability, enhanced cell apoptosis, cytokines production, and levels of amylase). Overexpression of B3GALT5-AS1 alleviated the caerulein-produced injury in the AR42J cells. Moreover, it was determined that miR-203 showed a downside expression by B3GALT5-AS1 regulation, and the overexpression of B3GALT5-AS1 retrained caerulein-produced injury through the suppression of miR-203. In addition, it was observed that miR-203 lessened the level of nuclear factor interleukin-3 (NFIL3) and that NFIL3 was targeted by miR-203. Lastly, the impacts of B3GALT5-AS1 on caerulein-induced cell injury were manifested through the NF-κB signalling pathway. The data from the present study revealed that in patients with AP, B3GALT5-AS1 is expressed in reduced amounts. Overexpression of B3GALT5-AS1 may alleviate caerulein-induced cell injury in AR42J cells through the regulation of miR-203/NFIL3 axis and by inhibiting the activation of the NF-κB signals.

Differential chamber-specific expression and regulation of long non-coding RNAs during cardiac development

Cardiovascular development is governed by a complex interplay between inducting signals such as Bmps and Fgfs leading to activation of cardiac specific transcription factors such as Nkx2.5, Mef2c and Srf that orchestrate the initial steps of cardiogenesis. Over the last decade we have witnessed the discovery of novel layers of gene regulation, i.e. post-transcriptional regulation exerted by non-coding RNAs. The function role of small non coding RNAs has been widely demonstrated, e.g. miR-1 knockout display several cardiovascular abnormalities during embryogenesis. More recently long non-coding RNAs have been also reported to modulate gene expression and function in the developing heart, as exemplified by the embryonic lethal phenotypes of Fendrr and Braveheart knock out mice, respectively. In this study, we investigated the differential expression profile during cardiogenesis of previously reported lncRNAs in heart development. Our data revealed that Braveheart, Fendrr, Carmen display a preferential adult expression while Miat, Alien, H19 preferentially display chamber-specific expression at embryonic stages. We also demonstrated that these lncRNAs are differentially regulated by Nkx2.5, Srf and Mef2c, Pitx2 > Wnt > miRNA signaling pathway and angiotensin II and thyroid hormone administration. Importantly isoform-specific expression and distinct nuclear vs cytoplasmic localization of Braveheart, Carmen and Fendrr during chamber morphogenesis is observed, suggesting distinct functional roles of these lncRNAs in atrial and ventricular chambers. Furthermore, we demonstrate by in situ hybridization a dynamic epicardial, myocardial and endocardial expression of H19 during cardiac development. Overall our data support novel roles of these lncRNAs in different temporal and tissue-restricted fashion during cardiogenesis.

Reciprocal Feedback Loop of the MALAT1-MicroRNA-194-YAP1 Pathway Regulates Progression of Acute Pancreatitis

Background

Acute pancreatitis (AP) has a high mortality rate and often has serious complications. The Hippo-YAP signaling pathway is mainly involved in cell proliferation and stem cell self-renewal. Recent studies have reported that YAP1 plays a crucial role in pancreatic cancer initiation and acute and chronic pancreatitis (CP). However, the role of YAP1 in AP still needs to be clarified.

Material/Methods

To assess the role of YAP1 in the progression of AP, we established a cell model of AP in AR42J cells. AR42J, a rat pancreatic acinar cell line, was stimulated with caerulein to mimic AP-like acinar cell injury. Levels of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) were measured by ELISA to investigate the role of YAP1 in the progression of AP.

Results

The results showed that YAP1 and MALAT1 were the targets of miR-194 and were upregulated in caerulein-treated AR42J cells. Overexpression of MALAT1 or YAP1 can increase the levels of IL-6 and TNF-α secreted by AR42J cells, while miR-194 dramatically counteracts this enhancement effect.

Conclusions

Our results demonstrated a regulation loop among MATAL1, miR-194, and YAP1, which dynamically regulates the progression of AP, providing a new therapeutic target for treatment of this disease.

GroEL Protein (Heat Shock Protein 60) of Mycoplasma gallisepticum Induces Apoptosis in Host Cells by Interacting with Annexin A2

Mycoplasma gallisepticum is an avian respiratory and reproductive tract pathogen that has a significant economic impact on the poultry industry worldwide. Although membrane proteins of Mycoplasma spp. are thought to play crucial roles in host interactions, very few have had their biochemical function defined. In this study, we found that the GroEL protein (heat shock protein 60) of Mycoplasma gallisepticum could induce apoptosis in peripheral blood mononuclear cells, and the underlying molecular mechanism was further determined. The GroEL gene from Mycoplasma gallisepticum was cloned and expressed in Escherichia coli to facilitate the functional analysis of recombinant protein. The purified GroEL protein was shown to adhere to peripheral blood mononuclear cells (PBMCs) and DF-1 cells and cause apoptosis in PBMCs. A protein pulldown assay coupled with mass spectrometry identified that annexin A2 possibly interacted with GroEL protein. Coimmunoprecipitation assays confirmed that GroEL proteins could bind to annexin A2, and confocal analysis further demonstrated that GroEL colocolized with annexin A2 in HEK293T cells and PBMCs. Moreover, annexin A2 expression was significantly induced by a recombinant GroEL protein in PBMCs, and knocking down annexin A2 expression resulted in significantly reduced apoptosis. Taken together, these data suggest that GroEL induces apoptosis in host cells by interacting with annexin A2, a novel virulence mechanism in Mycoplasma gallisepticum Our findings lead to a better understanding of molecular pathogenesis in Mycoplasma gallisepticum.