N-Myc-Interacting Protein Negatively Regulates TNF-α-Induced NF-κB Transcriptional Activity by Sequestering NF-κB/p65 in the Cytoplasm

Dietary pyruvate targets cytosolic phospholipase A2 to mitigate inflammation and obesity in mice

Obesity has a multifactorial etiology and is known to be a state of chronic low-grade inflammation, known as meta-inflammation. This state is associated with the development of metabolic disorders such as glucose intolerance and nonalcoholic fatty liver disease. Pyruvate is a glycolytic metabolite and a crucial node in various metabolic pathways. However, its role and molecular mechanism in obesity and associated complications are obscure. In this study, we reported that pyruvate substantially inhibited adipogenic differentiation in vitro and its administration significantly prevented HFD-induced weight gain, white adipose tissue inflammation, and metabolic dysregulation. To identify the target proteins of pyruvate, drug affinity responsive target stability was employed with proteomics, cellular thermal shift assay, and isothermal drug response to detect the interactions between pyruvate and its molecular targets. Consequently, we identified cytosolic phospholipase A2 (cPLA2) as a novel molecular target of pyruvate and demonstrated that pyruvate restrained diet-induced obesity, white adipose tissue inflammation, and hepatic steatosis in a cPLA2-dependent manner. Studies with global ablation of cPLA2 in mice showed that the protective effects of pyruvate were largely abrogated, confirming the importance of pyruvate/cPLA2 interaction in pyruvate attenuation of inflammation and obesity. Overall, our study not only establishes pyruvate as an antagonist of cPLA2 signaling and a potential therapeutic option for obesity but it also sheds light on the mechanism of its action. Pyruvate's prior clinical use indicates that it can be considered a safe and viable alternative for obesity, whether consumed as a dietary supplement or as part of a regular diet.

N-myc and STAT interactor degrades interferon regulatory factor 7 mediated type I interferon signaling to promote duck Tembusu virus replication

N-myc and STAT interactor (NMI) is an interferon-induced protein, which plays a variety of biological functions by participating in signal transduction and transcriptional activation, it has been reported to regulate antiviral response of different viruses in many species. However, the role of NMI in ducks during Duck Tembusu Virus (DTMUV) infection is completely unknown. In order to reveal whether duck NMI (duNMI) is involved in the antiviral response in the process of DTMUV infection and its role, we cloned and identified duNMI gene, and conducted sequence analysis of duNMI, the open reading frame region of duNMI gene is 1,137 bp, encoding 378 amino acid residues (aa), including 3 domains, Coiled-coil domain (22-126aa), NMI/IFP 35 domain 1 (NID1) domain (174-261aa) and NMI/IFP 35 domain 2 (NID2) domain (272-360aa). Analysis of tissue distribution of duNMI in 7-day-old ducks shows that the expression of duNMI is the highest in harderian gland, followed by small intestine and pancreas. Subsequently, we found that mRNA level of duNMI increases significantly after DTMUV stimulation, and overexpression of duNMI inhibits DTMUV replication in a dose-dependent manner. Besides, duNMI inhibits the transcriptional activity of IFN-I related cytokines. Specifically, we confirmed that duNMI interacts with duck regulatory factor 7 (duIRF7) through NID1 and NID2 domains and inhibit its expression and activated-IFN-β. These results support that duNMI is an inhibitor of antiviral innate immune response in the process of DTMUV infection, which will provide a theoretical basis for the prevention of DTMUV infection.

VEGF promotes diabetic retinopathy by upregulating the PKC/ET/NF-κB/ICAM-1 signaling pathway

Diabetic retinopathy (DR) is a common microvascular complication in patients with diabetes mellitus. DR is caused by chronic hyperglycemia and is characterized by progressive loss of vision because of damage to the retinal microvasculature. In this study, we investigated the regulatory role and clinical significance of the vascular endothelial growth factor (VEGF)/protein kinase C (PKC)/endothelin (ET)/nuclear factor-κB (NF-κB)/intercellular adhesion molecule 1 (ICAM-1) signaling pathway in DR using a rat model. Intraperitoneal injections of the VEGF agonist, streptozotocin (STZ) were used to generate the DR model rats. DR rats treated with the VEGF inhibitor (DR+VEGF inhibitor) were used to study the specific effects of VEGF on DR pathology and the underlying mechanisms. DR and DR+VEGF agonist rats were injected with the PKCβ2 inhibitor, GF109203X to determine the therapeutic potential of blocking the VEGF/PKC/ET/NF-κB/ICAM-1 signaling pathway. The body weights and blood glucose levels of the rats in all groups were evaluated at 16 weeks. DR-related retinal histopathology was analyzed by hematoxylin and eosin staining. ELISA assay was used to estimate the PKC activity in the retinal tissues. Western blotting and RT-qPCR assays were used to analyze the expression levels of PKC-β2, VEGF, ETs, NF-κB, and ICAM-1 in the retinal tissues. Immunohistochemistry was used to analyze VEGF and ICAM-1 expression in the rat retinal tissues. Our results showed that VEGF, ICAM-1, PKCβ2, ET, and NF-κB expression levels as well as PKC activity were significantly increased in the retinal tissues of the DR and DR+VEGF agonist rat groups compared to the control and DR+VEGF inhibitor rat groups. DR and DR+VEGF agonist rats showed significantly lower body weight and significantly higher retinal histopathology scores and blood glucose levels compared to the control and DR+VEGF inhibitor group rats. However, treatment of DR and DR+VEGF agonist rats with GF109203X partially alleviated DR pathology by inhibiting the VEGF/ PKC/ET/NF-κB/ICAM-1 signaling pathway. In summary, our data demonstrated that inhibition of the VEGF/ PKC/ET/NF-κB/ICAM-1 signaling pathway significantly alleviated DR-related pathology in the rat model. Therefore, VEGF/PKC/ET/NF-κB/ICAM-1 signaling axis is a promising therapeutic target for DR.

Molecular characterization and transcriptional conservation of N-myc-interactor, Nmi, by type I and type II IFNs in mandarin fish Siniperca chuatsi

N-myc-interactor (Nmi) belongs to interferon (IFN) stimulated genes (ISGs) and is involved in the regulation of physiological processes including viral infection, inflammatory response, apoptosis and tumorigenesis in mammals. However, the function of Nmi in teleost fish remains to be explored. In this study, an Nmi homologue was characterized from mandarin fish Siniperca chuatsi. The mandarin fish Nmi shares two conserved functional Nmi/IFP35 homology domains (NIDs) with mammalian Nmi protein in its C-terminal domain and a coiled coil region (CC) in its N-terminal domain, with its genomic DNA sequence consisting of nine exons and eight introns. Subcellular localization analysis shows that mandarin fish Nmi is a cytoplasmic protein and that its localization is dependent on the CC and NID1 regions. High and constitutive mRNA level of Nmi was observed in all examined tissues, with the highest level being observed in blood. In addition, the Nmi gene was significantly induced in various organs/tissues following the infection of infectious spleen and kidney necrosis virus (ISKNV), and its mRNA and protein level was also significantly induced in vitro after the treatment of IFNh, IFNc, as well as IFN-γ. The dual luciferase activity analysis indicated that the Nmi promoter was activated by the three type I IFNs through interferon-stimulated response element (ISRE) sites, and it can be also transcriptionally activated by IFN-γ via IRF1 which can activate the expression of Nmi through ISRE. Taken together, it is demonstrated in this study that the transcription of Nmi in mandarin fish can be regulated by type I and type II IFNs, thus confirming that Nmi in fish is also an ISG, and is involved in antiviral and IFN-induced innate immunity.

Zhikang Capsule Ameliorates Inflammation, Drives Polarization to M2 Macrophages, and Inhibits Apoptosis in Lipopolysaccharide-induced RAW264.7 Cells

OBJECTIVE

To explore the anti-inflammatory effect of the traditional Chinese medicine Zhikang capsule (ZKC) on lipopolysaccharide (LPS)-induced RAW264.7 cells.

METHODS

Safe concentrations of ZKC (0.175, 0.35, and 0.7 mg/mL) were used after the half-maximal inhibitory concentration (IC₅₀) of RAW264.7 cells was calculated through the CCK-8 assay. In addition, the optimal intervention duration of ZKC (0.7 mg/mL) on RAW264.7 cells was determined to be 6 h, since all proinflammatory mediators [tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), inteleukin-6 (IL-6), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and monocyte chemotactic protein-1 (MCP-1)] had a decreasing tendency and relatively down-regulated mRNA expression levels as compared with other durations (4, 8, and 12 h). RAW264.7 cells were pretreated with ZKC at various concentrations (0.175, 0.35 and 0.7 mg/mL) for 6 h and then stimulated with LPS (1 µg/mL) for an additional 12 h.

RESULTS

In terms of inflammation, ZKC could reverse LPS-induced upregulation of TNF-α, IL-1β, IL-6, COX-2, iNOS, and MCP-1 at both the mRNA and protein levels in RAW264.7 cells in a dose-dependent manner. In terms of the NF-κB signaling pathway, ZKC could reduce phosphorylated p65 and promote M2 polarization of RAW264.7 cells under LPS stimulation in a dose-dependent manner. Moreover, ZKC exhibited a protective effect on macrophages from apoptosis.

CONCLUSION

ZKC exhibited obvious antiinflammatory and anti-apoptotic effects on LPS-induced RAW264.7 cells at the cellular level, and a weakened NF-κB signaling pathway may be a potential significant target.

NMI Facilitates Influenza A Virus Infection by Promoting Degradation of IRF7 through TRIM21

Acute respiratory infections caused by influenza A virus (IAV) spread widely and lead to substantial morbidity and mortality. Host cell induction of type I interferon (IFN-I) plays a fundamental role in eliminating the virus during the innate antiviral response. The potential role of N-myc and STAT interactor (NMI) and its underlying mechanisms of action during IAV infection, however, remain elusive. In this study, we found that the expression of NMI increased after IAV infection. Nmi-knockout mice infected with IAV displayed increased survival rate, decreased weight loss, lower viral replication, and attenuated lung inflammation when compared with wild-type mice. Deficiency of NMI promoted the production of IFN-I and IFN-stimulated genes in vivo and in vitro. Reduced levels of NMI also resulted in an increase of the expression of IFN regulator factor (IRF) 7. Further studies have revealed that NMI could interact with IRF7 after IAV infection, and this interaction involved its NID1 and NID2 domain. In addition, NMI facilitated ubiquitination and proteasome-dependent degradation of IRF7 through recruitment of the E3 ubiquitin ligase TRIM21 (tripartite motif-containing 21) to limit the IAV-triggered innate immunity. Our findings reveal a clearer understanding of the role of NMI in regulating the host innate antiviral response and provide a potential therapeutic target for controlling IAV infection.

The Role of Chinese Herbal Therapy in Methamphetamine Abuse and its Induced Psychiatric Symptoms

Repeated intake of methamphetamine (METH) leads to drug addiction, the inability to control intake, and strong drug cravings. It is also likely to cause psychiatric impairments, such as cognitive impairment, depression, and anxiety. Because the specific neurobiological mechanisms involved are complex and have not been fully and systematically elucidated, there is no established pharmacotherapy for METH abuse. Studies have found that a variety of Chinese herbal medicines have significant therapeutic effects on neuropsychiatric symptoms and have the advantage of multitarget comprehensive treatment. We conducted a systematic review, from neurobiological mechanisms to candidate Chinese herbal medicines, hoping to provide new perspectives and ideas for the prevention and treatment of METH abuse.

Sequoyitol Alleviates High Glucose-Induced Inflammation, Oxidative Stress and Apoptosis of Retina Epithelial Cells

Diabetic retinopathy (DR) is a serious microvascular complication of diabetes, contributing to visual impairment and blindness. Sequoyitol (Seq), a form of inositol derivatives, has been demonstrated to be a therapeutic potential for diabetes and diabetic nephropathy. The aim of this study is to explore the effects of Seq on DR. ARPE-19 cells were cultured in high glucose (HG) condition to simulate DR in vitro. Seq (1,10 and 20 µM) was applied for treatment. CCK-8 assay was performed to detect cell viability. Flow cytometry analysis was conducted to determine cell apoptosis rate. The production level of inflammatory cytokines and oxidative stress-related factors were determined using their commercial kits. The protein expressions of corresponding genes were detected using western blotting. The results revealed that Seq significantly increased cell viability and protein expression of PCNA and Ki67 which were decreased after HG induction. HG promoted cell apoptosis by decreasing protein expression of Bcl-2 and increasing protein expression of Bax and cleaved caspase-3, which was then reversed by Seq treatment. Besides, Seq abolished the promoting effects of HG on the production of pro-inflammatory cytokines and oxidative stress-related factors. Furthermore, Seq suppressed the promoting effect of HG on the activation of NF-κB signaling by inhibiting phosphorylation of kBa and NF-κB nucleus translocation. These results indicated that Seq might protect ARPE-19 cells against HG-induced cell viability, apoptosis, inflammation and oxidative stress by regulating NF-κB signaling, providing evidence for the potential application of Seq in the therapy of DR.

N-myc-interactor mediates microbiome induced epithelial to mesenchymal transition and is associated with chronic lung allograft dysfunction

BACKGROUND

Recent evidence suggests a role for lung microbiome in occurrence of chronic lung allograft dysfunction (CLAD). However, the mechanisms linking the microbiome to CLAD are poorly delineated. We investigated a possible mechanism involved in microbial modulation of mucosal response leading to CLAD with the hypothesis that a Proteobacteria dominant lung microbiome would inhibit N-myc-interactor (NMI) expression and induce epithelial to mesenchymal transition (EMT).

METHODS

Explant CLAD, non-CLAD, and healthy nontransplant lung tissue were collected, as well as bronchoalveolar lavage from 14 CLAD and matched non-CLAD subjects, which were followed by 16S rRNA amplicon sequencing and quantitative polymerase chain reaction (PCR) analysis. Pseudomonas aeruginosa (PsA) or PsA-lipopolysaccharide was cocultured with primary human bronchial epithelial cells (PBEC). Western blot analysis and quantitative reverse transcription (qRT) PCR was performed to evaluate NMI expression and EMT in explants and in PsA-exposed PBECs. These experiments were repeated after siRNA silencing and upregulation (plasmid vector) of EMT regulator NMI.

RESULTS

16S rRNA amplicon analyses revealed that CLAD patients have a higher abundance of phyla Proteobacteria and reduced abundance of the phyla Bacteroidetes. At the genera level, CLAD subjects had an increased abundance of genera Pseudomonas and reduced Prevotella. Human CLAD airway cells showed a downregulation of the N-myc-interactor gene and presence of EMT. Furthermore, exposure of human primary bronchial epithelial cells to PsA resulted in downregulation of NMI and induction of an EMT phenotype while NMI upregulation resulted in attenuation of this PsA-induced EMT response.

CONCLUSIONS

CLAD is associated with increased bacterial biomass and a Proteobacteria enriched airway microbiome and EMT. Proteobacteria such as PsA induces EMT in human bronchial epithelial cells via NMI, demonstrating a newly uncovered mechanism by which the microbiome induces cellular metaplasia.

Downregulation of N-myc Interactor Promotes Cervical Cancer Cells Growth by Activating Stat3 Signaling

N-myc interactor (NMI), a member of the oncogene Myc family, has been reported to be closely related to the development of cancer. However, the character of NMI in cervical carcinoma has not been reported. Herein, we found that downregulation of NMI protein not only promoted the proliferation, migration, and invasion of HeLa cells, but also decreased their expression of Caspase-3 and Caspase-9. Silencing NMI promotes the epithelial-mesenchymal transition of human cervical carcinoma HeLa cells by upregulating N-cadherin, vimentin, and downregulating E-cadherin. Further investigation illustrated the downregulation of NMI can activate the STAT3 signaling pathway. In conclusion, we found that the downregulation of NMI plays an important role in the progression of cervical cancer, and may served as a novel therapeutic target for cervical cancer.

Integrated Analysis of the Mechanisms of Da-Chai-Hu Decoction in Type 2 Diabetes Mellitus by a Network Pharmacology Approach

Background

The incidence of type 2 diabetes mellitus (T2DM) has increased year by year, which not only seriously affects people's quality of life, but also imposes a heavy economic burden on the family, society, and country. Currently, the pathogenesis, diagnosis, and treatment of T2DM are still unclear. Therefore, exploration of a precise multitarget treatment strategy is urgent. Here, we attempt to screen out the active components, effective targets, and functional pathways of therapeutic drugs through network pharmacology with taking advantages of traditional Chinese medicine (TCM) formulas for multitarget holistic treatment of diseases to clarify the potential therapeutic mechanism of TCM formulas and provide a systematic and clear thought for T2DM treatment.

Methods

First, we screened the active components of Da-Chai-Hu Decoction (DCHD) by absorption, distribution, metabolism, excretion, and toxicity (ADME/T) calculation. Second, we predicted and screened the active components of DCHD and its therapeutic targets for T2DM relying on the Traditional Chinese Medicine Systems Pharmacology Analysis Platform (TCMSP database) and Text Mining Tool (GoPubMed database), while using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) to obtain T2DM targets. Third, we constructed a network of the active component-target, target-pathway of DCHD using Cytoscape software (http://cytoscape.org/,ver.3.5.1) and then analyzed gene function, related biological processes, and signal pathways through the DAVID database.

Results

We screened 77 active components from 1278 DCHD components and 116 effective targets from 253 ones. After matching the targets of T2DM, we obtained 38 important targets and 7 core targets were selected through further analysis. Through enrichment analysis, we found that these important targets were mainly involved in many biological processes such as oxidative stress, inflammatory reaction, and apoptosis. After analyzing the relevant pathways, the synthetic pathway for the treatment of T2DM was obtained, which provided a diagnosis-treatment idea for DCHD in the treatment of T2DM.

Conclusions

This article reveals the mechanism of DCHD in the treatment of T2DM related to inflammatory response and apoptosis through network pharmacology, which lays a foundation for further elucidation of drugs effective targets.

MiR-139-5p negatively regulates PMP22 to repress cell proliferation by targeting the NF-κB signaling pathway in gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors worldwide. Peripheral myelin protein 22 (PMP22) is a 22-kDa tetraspan glycoprotein that is predominantly expressed by myelinating Schwann cells. However, recent studies have shown that PMP22 is closely related to cell proliferation and tumorigenesis in different cancers. In this study, we discovered a new miRNA that regulates PMP22 and gastric cancer cell prolifration. Our bioinformatics analysis suggested that there is a conserved miRNA recognition site for miR-139-5p on the 3' UTR of PMP22. Interestingly, our results showed overexpression of miR-139-5p significantly suppressed growth and prolifration in GC cells and inhibited tumor growth in nude mice xenografted with GC cells. MiR-139-5p suppressed the activity of a luciferase reporter containing the PMP22-3' UTR, and the ectopic expression of PMP22 rescued the miR-139-5p-mediated inhibition of cell proliferation in GC cells. Mechanistically, miR-139-5p may negatively regulate PMP22 to repress cell proliferation by targeting the NF-κB signaling pathway in gastric cancer. Finally, overexpression of miR-139-5p significantly inhibited tumor growth in nude mice xenografted with GC cells.and the miR-139-5p levels were inversely correlated with PMP22 expression in nude mice tumor. Taken together, our data suggest an important regulatory role of miR-139-5p in gastric cancer, suggesting that miR-139-5p and PMP22 might be important diagnostic or therapeutic targets for gastric cancer and other human diseases.

N-myc and STAT interactor correlates with severity and prognosis in acute-on-chronic liver failure of hepatitis B virus

BACKGROUND AND AIM

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is characterized by acute deterioration of chronic liver disease with excessive inflammation. N-myc and STAT interactor (NMI), an inflammation-mediated protein, involves in various inflammatory-related diseases, but the role of NMI in development and prognosis in HBV-ACLF remains to be elucidated.

METHODS

Serum NMI from healthy controls (HCs, n = 20), chronic hepatitis B (CHB, n = 50) patients, and HBV-ACLF patients (n = 50) was determined using ELISA. NMI from peripheral blood mononuclear cells and liver was confirmed using quantitative real-time polymerase chain reaction, Western blot, and immunofluorescence.

RESULTS

Serum NMI was increased 1.9-fold or 2.2-fold from HBV-ACLF patients compared with that from HCs (P < 0.01) or CHB patients (P < 0.01). Consistently, NMI from peripheral blood mononuclear cells was upregulated significantly from HBV-ACLF patients compared with that from HCs and CHB patients at mRNA and protein levels. Hepatic NMI from HBV-ACLF patients was 2.8-fold higher than that from HCs. Serum NMI was correlated with Model for End-stage Liver Disease, Chronic Liver Failure Consortium ACLF score, and ACLF grades. In contrast, serum NMI was significantly decreased in HBV-ACLF ameliorated patients during follow-up, whereas serum NMI was sustained at high levels in non-ameliorated patients. Elevated serum NMI (≥ 198.5 pg/mL) was correlated with poor survival rate of HBV-ACLF patients. Using receiver operating characteristics curves, it was suggested that serum NMI was a potential biomarker in predicting 3-month mortality of HBV-ACLF patients.

CONCLUSIONS

Our study highlights the potential role of NMI in assessing the development and prognosis of HBV-ACLF.

Tannic acid inhibits NLRP3 inflammasome-mediated IL-1β production via blocking NF-κB signaling in macrophages

The NLRP3 inflammasome rapidly responds to many infections and stress signals and is involved in the pathogenesis of numerous inflammatory disease processes. Tannic acid plays a role in antioxidant, antifungal and antitumor activities. Here, we reported that tannic acid inhibited NLRP3 inflammasome activation by blocking NF-κB signaling to suppress IL-1β secretion. We found that the BMDMs (bone marrow-derived macrophages cells) pre-treated with tannic acid blocked caspase-1 cleavage and inhibited IL-1β secretion in a NLRP3-dependent manner, and suppressed NF-κB signaling activation by inhibiting NF-κB/P65 nuclear localization, suggesting that tannic acid inhibited NLRP3 inflammasome activation. These investigations revealed that tannic acid inhibited NLRP3 inflammasome activation via blocking NF-κB signaling in macrophages, providing us with evidence that tannic acid may be a potent inhibitor for NLRP3-driven diseases.

Identification of specific feed-forward apoptosis mechanisms and associated higher survival rates for low grade glioma and lung squamous cell carcinoma

The mechanisms of cell proliferation due to the overexpression of certain transcription factors (TFs) have been well documented in the cancer setting. However, many of these same TFs have pro-apoptotic effects, particularly when expressed or activated at high levels, a process referred to as feed-forward apoptosis (FFA). To determine whether cancers could be stratified on the basis of specific FFA signatures, RNASeq data representing samples from the cancer genome atlas were analyzed, revealing that high expression of the pro-proliferative TFs, MYC and YY1, is associated with a favorable outcome in low-grade glioma (LGG) and lung squamous cell carcinoma (LUSC), respectively. Analysis of the RNASeq data also led to the identification of specific apoptosis-effector genes whose expression levels correlate with increased survival rates, for both LGG and LUSC. Although FFA has been demonstrated as a general effect in cancer, in this report, for the first time, results identify specific TFs and their responsive effector genes that distinguish subsets of cancer samples undergoing more or less of a FFA process in a way that is associated with distinct patient survival rates.