Generation of a competing endogenous RNA network and validation of BNIP1 expression in the lung of irradiated mice.

BACKGROUND: Radiation-induced lung injury (RILI) is a serious complication of radiation therapy, and it is mediated by long non-coding RNAs (lncRNAs). STUDY DESIGN AND METHODS: Mouse lung tissues were examined using RNA-Seq and RNA-Seq libraries 72 h after the administration of 6 Gy of X-ray irradiation. The target mRNAs were functionally annotated and the target lncRNA-based miRNAs and target miRNA-based mRNAs were predicted after irradiation to establish the lncRNA-miRNA-mRNA ceRNA axis. RESULTS: The analyses showed that relative to unirradiated controls, 323 mRNAs, 114 miRNAs, and 472 lncRNAs were significantly up-regulated following irradiation, whereas 1907 mRNAs, 77 miRNAs, and 1572 lncRNAs were significantly down-regulated following irradiation. Voltage-gated ion channels, trans-membrane receptor protein tyrosine kinases, and vascular endothelial growth factor have all been associated with dysregulated miRNA-mRNA relationships. KEGG pathway analysis of the dysregulated miRNA-mRNA targets revealed involvement in pathways associated with the hedgehog signaling pathway-fly, ErbB signaling, VEGF signaling, axon guidance, and focal adhesion. KEGG analysis of differentially expressed showed enrichment of mRNAs in primary immunodeficiency, the intestinal immune axis for IgA production, hematopoietic cell lineages, systemic lupus erythematosus, and Th1 and Th2 cell differentiation. Finally, the ceRNA network revealed that BNIP1 was a critical mRNA modulated by the most significant upregulation of lncRNA E230013L22Rik. CONCLUSION: In summary, the lncRNA-miRNA-mRNA ceRNA axis of RILI was constructed following irradiation in a mouse model. RNA dysregulation in the early stage of RILI may lead to severe complications at a later stage, with BNIP1 contributing to radiation-induced cellular apoptosis in RILI.

Evaluation of the lncRNA-miRNA-mRNA ceRNA network in lungs of miR-147 -/- mice.

Background: Previous studies have documented important roles for microRNA-147 (miR-147) in inflammation, radiation-induced injury, cancer, and a range of other diseases. Murine lungs exhibit high levels of miRNA, mRNA, and lncRNA expression. However, very little research to date has focused on the lncRNA-miRNA-mRNA competing endogenous RNA (ceRNA) networks associated with miR-147, and the regulation of lncRNAs and miRNAs in this setting remains poorly understood. Methods: After establishing a miR-147-/- model mouse, samples of lung tissue were harvested for RNA-sequencing, and differentially expressed lncRNAs, miRNAs, and mRNAs were identified. The miRNA targets of these lncRNAs and the identified miRNAs were first overlapped to facilitate the prediction of target mRNAs, with analyses then examining the overlap between these targets and mRNAs that were differentially expressed. Then, these target mRNAs were subjected to pathway enrichment analyses. These results were ultimately used to establish a miR-147-related ceRNA network. Results: Relative to wild-type mice, the lungs of miR-147-/- mice exhibited 91, 43, and 71 significantly upregulated lncRNAs, miRNAs, and mRNAs, respectively, together with 114, 31, and 156 that were significantly downregulated. The lncRNA-miRNA-mRNA network established based on these results led to the identification of Kcnh6 as a differentially expressed hub gene candidate and enabled the identification of a range of regulatory relationships. KEGG pathway enrichment showed that the mRNA targets of differentially expressed lncRNAs and miRNAs in the mice were associated with tumor-related signaling, endometrial cancer, bladder cancer, and ErbB signaling. Conclusion: These results suggest that the identified ceRNA network in miR-147-/- mice shapes tumor-associated signaling activity, with miR-147 potentially regulating various lncRNAs and miRNAs through Kcnh6, ultimately influencing tumorigenesis. Future studies of the lncRNA, miRNA, and mRNA regulatory targets shown to be associated with miR-147 in the present study may ultimately lead to the identification of novel clinically relevant targets through which miR-147 shapes the pathogenesis of cancer and other diseases.

Analysis of lncRNA-miRNA-mRNA Expression in the Troxerutin-Mediated Prevention of Radiation-Induced Lung Injury in Mice.

Background: Radiation-induced lung injury (RILI) is a critical factor that leads to pulmonary fibrosis and other diseases. LncRNAs and miRNAs contribute to normal tissue damage caused by ionizing radiation. Troxerutin offers protection against radiation; however, its underlying mechanism remains largely undetermined. Methods: We established a model of RILI in mice pretreated with troxerutin. The lung tissue was extracted for RNA sequencing, and an RNA library was constructed. Next, we estimated the target miRNAs of differentially expressed (DE) lncRNAs, and the target mRNAs of DE miRNAs. Then, functional annotations of these target mRNAs were performed using GO and KEGG. Results: Compared to the control group, 150 lncRNA, 43 miRNA, and 184 mRNA were significantly up-regulated, whereas, 189 lncRNA, 15 miRNA, and 146 mRNA were markedly down-regulated following troxerutin pretreatment. Our results revealed that the Wnt, cAMP, and tumor-related signaling pathways played an essential role in RILI prevention via troxerutin using lncRNA-miRNA-mRNA network. Conclusion: These evidences revealed that the abnormal regulation of RNA potentially leads to pulmonary fibrosis. Therefore, targeting lncRNA and miRNA, along with a closer examination of competitive endogenous RNA (ceRNA) networks are of great significance to the identification of troxerutin targets that can protect against RILI.

Construction and validation of a competing endogenous RNA network in the thymus of miR-147-/- mice.

BACKGROUND: Prior evidence has demonstrated that miR-147 can regulate cellular proliferation, migration, apoptotic death, inflammatory responses, and the replication of viruses through its interactions with specific mRNA targets. LncRNA-miRNA-mRNA interactions are often found in various biological processes. No studies have documented lncRNA-miRNA-mRNA regulatory interactions in miR-147-/- mice. METHODS: Thymus tissue samples from miR-147-/- mice were systematically analyzed to detect patterns of lncRNA, miRNA, and mRNA dysregulation in the absence of this biologically important miRNA. Briefly, RNA-sequencing was used to analyze samples of thymus tissue from wild-type (WT) and miR-147-/- mice. Radiation damage models of miR-147-/- mice were prepared and prophylactic intervention with the drug trt was performed. The validation of miR-47, PDPK1,AKT and JNK were carried out by qRT-PCR, western blot and fluorescence in situ hybridization. Apoptosis was detected by Hoechst staining, and histopathological changes were detected by HE staining. RESULTS: We showed the identification of 235 mRNAs, 63 lncRNAs, and 14 miRNAs that were significantly upregulated in miR-147-/- mice as compared to WT controls, as well as 267 mRNAs, 66 lncRNAs and 12 miRNAs exhibiting significant downregulation. Predictive analyses of the miRNAs targeted by dysregulated lncRNAs and their associated mRNAs were further performed, highlighting the dysregulation of pathways including the Wnt signaling pathway, Thyroid cancer, Endometrial cancer (include PI3K/AKT) and Acute myeloid leukemia pathway(include PI3K/AKT) pathways. Troxerutin (TRT) upregulated PDPK1 via targeting miR-147 to promote AKT activation and inhibit JNK activation in the lungs of mice in radioprotection. CONCLUSION: Together, these results highlight the potentially important role of miR-147 as a key regulator of complex lncRNA-miRNA-mRNA interacting networks. Further research focusing on PI3K/AKT pathways in miR-147-/- mice in radioprotection will thus benefit current knowledge of miR-147 while also informing efforts to improve radioprotection.

Activation of long-non-coding RNA NEAT1 sponging microRNA-147 inhibits radiation damage by targeting PDPK1 in troxerutin radioprotection.

A better understanding of the molecular mechanism involving the lncRNA-miRNA-mRNA network underlying radiation damage can be beneficial for radioprotection. This study was designed to investigate the potential role of lncRNA NEAT1, miR-147 and Phosphoinositide Dependent Protein Kinase 1 (PDPK1) interaction in radioprotection by troxerutin (TRT). We first demonstrated that NEAT1 sponged miR-147, and PDPK1 mRNA was the primary target of miR-147. In the cells, the NEAT1 and PDPK1 levels were downregulated after the radiation but increased after the treatment with TRT. The miR-147 level was significantly induced by radiation and inhibited by TRT. NEAT1 negatively regulated the expression of miR-147, whereas miR-47 targeted PDPK1 to downregulate its expression. In radioprotection, TRT effectively upregulated NEAT1 to inhibit miR-147 and to upregulate PDPK1. We concluded that TRT could promote radioprotection by stimulating NEAT1 to upregulate PDPK1 expression by suppressing miR-147. NEAT1 could be a critical therapeutic target of radiation damage.

Targeting p65 to inhibit Cas3 transcription by Onjisaponin B for radiation damage therapy in p65+/- mice.

BACKGROUND: In response to radiation injury, p65 becomes activated. The formation of p65 is one target of Onjisaponin B (OB), but it has not been studied in radioprotection. In addition, there is a binding site for p65 in the promoter region of Cas3. This study evaluates the use of OB as an intervention to modulate p65/Cas3 following radiation exposure. PURPOSE: This study aimed to confirm that OB regulated the transcription of Cas3 via p65 to overcome radiation-induced damage. STUDY DESIGN AND METHODS: Cells and mice were exposed to X-rays at a dose of 6 Gy. Immunofluorescence was used to locate intracellular p65. For the protein and mRNA analyses, Western blotting and RT-qPCR-based assays were conducted accordingly. HE staining was used to observe pathological changes in tissues. DNA damage was detected by the comet assay and DNA ladder assay. Next, apoptosis was detected by flow cytometry and Hoechst staining. RESULTS: Compared with the radiation group, the expression levels of p-p65 and c-Cas3 in the drug group were significantly down-regulated by OB 20 µg/ml. When the expression of p65 was suppressed in V79 and TC cells, OB did not significantly inhibit the activation of p65 or Cas3 in response to irradiation, nor did it significantly inhibit the phosphorylation of p65 and subsequent nuclear translocation. Overexpression of p65 in V79 and MTEC-1 cells resulted in OB significantly inhibiting the activation of p65 and Cas3, and the phosphorylation and translocation of p65 into the nucleus. At 3 d for V79 cells and 24 h for MTEC-1 cells after radiation, compared with the Cas3 over plasmid transfection group, the drug transfection group had no significant effect on reducing apoptosis. In p65+/- mice, expression of the p65 gene was knocked down, leading to increased tissue apoptosis and inflammation, and serious tissue pathological changes. The inhibition of p65 activation by OB after radiation exposure was not apparent in the thymus, although it was observed in the lung. CONCLUSIONS: OB interfered with radiation injury by targeting and regulating p65/Cas3. Therefore, it has been concluded that p65 is an important target molecule for the treatment of radiation injury.

Flavonoids from Rosaroxburghii Tratt prevent reactive oxygen species-mediated DNA damage in thymus cells both combined with and without PARP-1 expression after exposure to radiation in vivo.

This study aimed to evaluate the role of FRT in ROS/DNA regulation with or without PARP-1 in radiation-injured thymus cells. The administration of FRT to PARP-1-/- (KO) mice demonstrated that FRT significantly increased the viability of thymus cells and decreased their rate of apoptosis through PARP-1. Radiation increased the levels of ROS, γ-H2AX and 53BP1, and induced DNA double strand breaks. Compared with wild type (WT) mice, levels of ROS, γ-H2AX and 53BP1 in KO mice were much less elevated. The FRT treatment groups also showed little reduction in these indicators in KO mice compared with WT mice. The results of the KO mice study indicated that FRT reduced ROS activation through inhibition of PARP-1. Furthermore, FRT reduced the concentrations of γ-H2AX by decreasing ROS activation. However, we found that FRT did not regulate 53BP1, a marker of DNA damage, because of its elimination of ROS. Levels of apoptosis-inducing factor (AIF), exhibited no significant difference after irradiation in KO mice. To summarize, ROS suppression by PARP-1 knockout in KO mice highlights potential therapeutic target either by PARP-1 inhibition combined with radiation or by treatment with a drug therapy alone. AIF-induced apoptosis could not be activated in KO mice.

Specific activation of mGlu2 induced IGF-1R transactivation in vitro through FAK phosphorylation.

Metabotropic glutamate receptor 2 (mGlu2) belongs to the group-II metabotropic glutamate (mGlu) receptors and is a neurotransmitter G protein-coupled receptor. The group-II mGlu receptors are promising antipsychotic targets, but the specific role of mGlu2 signaling remains unclear. Receptor tyrosine kinases (RTKs) are also believed to participate in brain pathogenesis. To investigate whether there is any communication between mGlu2 and RTKs, we generated a CHO-mGlu2 cell line that stably expresses mGlu2 and showed that activation of mGlu2 by LY379268, a group II mGlu agonist, was able to transactivate insulin-like growth factor 1 receptor (IGF-1R). We further determined that the Gi/o protein, Gßγ subunits, phospholipase C, and focal adhesion kinase (FAK) were involved in the IGF-1R transactivation signaling axis, which further induced the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2) and cAMP response element-binding protein. In primary mouse cortical neurons, similar signaling pathways were observed when mGlu2 were stimulated by LY487379, an mGlu2 positive allosteric modulator. Transactivation of IGF-1R through FAK in response to mGlu2 should provide a better understanding of the association of mGlu2 with brain disease.

Isolation and characterization of another cDNA encoding a chorismate mutase from the phytoparasitic nematode Meloidogyne arenaria.

A new cDNA, named Ma-cm-2, encoding a chorismate mutase (CM), has been isolated from Meloidogyne arenaria. The full-length cDNA, carrying the trans-spliced SL1 leader sequence, was 753-bp long with an open reading frame of 576 bp. The deduced protein MA-CM-2 including amino-terminal signal peptide shows significant similarity to CMs of Meloidogyne incognita, Meloidogyne javanica, and also bacteria. Secondary structure prediction of MA-CM-2 indicates the presence of the three conserved alpha-helix domains present in the Escherichia coli CMs. Reverse transcription and polymerase chain reaction analysis showed that its transcript abundance is high in the early developmental stages and low in later ones. In situ mRNA hybridization revealed that the transcripts of Ma-cm-2 accumulated specifically in the two subventral oesophageal gland cells of M. arenaria. The widespread existence of CMs in the sedentary endoparasitic nematodes implicates that this enzyme plays an important role in the host-parasite interaction.