Dimethyl itaconate alleviates the pyroptosis of macrophages through oxidative stress.

Macrophages are involved in the pathophysiology of many diseases as critical cells of the innate immune system. Pyroptosis is a form of macrophage death that induces cytokinesis of phagocytic substances in the macrophages, thereby defending against infection. Dimethyl itaconate (DI) is an analog of itaconic acid with anti-inflammatory effects. However, the effect of dimethyl itaconate on macrophage pyroptosis has not been elucidated clearly. Thus, the present study aimed to analyze the effect of DI treatment on a macrophage pyroptosis model (Lipopolysaccharide, LPS + Adenosine Triphosphate, ATP). The results showed that 0.25 mM DI ameliorated macrophage pyroptosis and downregulated interleukin (IL)-1ß expression. Then, real-time quantitative polymerase chain reaction (RT-qPCR) was used to confirm the result of RNA-sequencing of the upregulated oxidative stress-related genes (Gclc and Gss) and downregulated inflammation-related genes (IL-12ß and IL-1ß). In addition, Gene Ontology (GO) enrichment analysis showed that differential genes were associated with transcript levels and DNA replication. Kyoto encyclopedia of genes and genomes (KEGG) enrichment showed that signaling pathways, such as tumor necrosis factor (TNF), Jak, Toll-like receptor and IL-17, were altered after DI treatment. N-acetyl-L-cysteine (NAC) reversed the DI effect on the LPS + ATP-induced macrophage pyroptosis and upregulated the IL-1ß expression. Oxidative stress-related protein Nrf2 is involved in the DI regulation of macrophage pyroptosis. Taken together, these findings suggested that DI alleviates the pyroptosis of macrophages through oxidative stress.

Macrophages enhance lipopolysaccharide induced apoptosis via Ang1 and NF-κB pathways in human umbilical vein endothelial cells.

Lipopolysaccharide (LPS) could induce apoptosis and dysfunction of endothelial cells. We aimed to reveal the effects of macrophages on cell proliferation and apoptosis in LPS induced human umbilical vein endothelial cells (HUVECs). THP-1 derived macrophages and HUVECs were co-cultured in the presence of LPS. Cell viability was measured by Cell Counting Kit-8 and apoptosis was analyzed by flow cytometry. Expression of Ang1, the NF-κB component p65 was evaluated by western blot and quantitative PCR. Small interfering RNAs (siRNAs) were used to knockdown the expression of proinflammatory cytokines and p65 in HUVECs. Plasmid transfection-mediated overexpression of Ang1 was employed to see its effects on cell proliferation and apoptosis in HUVECs. Macrophages enhanced LPS-induced proliferation impairments and apoptosis in HUVECs, which could be attenuated by siRNA-mediated knockdown of cytokines TNF-α, IL-1ß, IL-6 and IL-12p70 in macrophages. The dysfunction of HUVECs was tightly associated with reduced Ang1 expression and increased phosphorylated p65 (p-65). Overexpression of Ang1 in HUVECs significantly decreased p-p65, suggesting negatively regulation of p-p65 by Ang1. Overexpression of Ang1, adding recombinant Ang1 or silencing of p65 substantially attenuated the dysfunction of HUVECs in terms of cell proliferation and apoptosis. In conclusions, THP-1-derived macrophages enhance LPS induced dysfunction of HUVECs via Ang1 and NF-κB pathways, suggesting new therapeutic targets for sepsis.

Genome-wide characterization and developmental expression profiling of long non-coding RNAs in Sogatella furcifera.

The genome-wide characterization of long non-coding RNA (lncRNA) in insects demonstrates their importance in fundamental biological processes. Essentially, an in-depth understanding of the functional repertoire of lncRNA in insects is pivotal to insect resources utilization and sustainable pest control. Using a custom bioinformatics pipeline, we identified 1861 lncRNAs encoded by 1852 loci in the Sogatella furcifera genome. We profiled lncRNA expression in different developmental stages and observed that the expression of lncRNAs is more highly temporally restricted compared to protein-coding genes. More up-regulated Sogatella furcifera lncRNA expressed in the embryo, 4th and 5th instars, suggesting that increased lncRNA levels may play a role in these developmental stages. We compared the relationship between the expression of Sogatella furcifera lncRNA and its nearest protein gene and found that lncRNAs were more correlated to their downstream coding neighbors on the opposite strand. Our genome-wide profiling of lncRNAs in Sogatella furcifera identifies exciting candidates for characterization of lncRNAs, and also provides information on lncRNA regulation during insect development.

Characterization and comparative analysis of microRNAs in the rice pest Sogatella furcifera.

MicroRNAs (miRNAs) are a class of endogenous regulatory RNA molecules 21-24 nucleotides in length that act as functional regulators of post-transcriptional repression of messenger RNA. We report the identification and characterization of a conserved miRNA and 171 novel miRNAs in the migratory rice pest Sogatella furcifera by deep sequencing, which were observed to be biased towards female adults of the insect, modulating the functionality and targets of the miRNAs in sex differentiation. A switch in arm usage was also observed in 9 miRNA when compared to the insect ancestor during insect evolution. The miRNA loci showed high 5' fidelity in both miRNA and star species and about 93.4% of WBPH miRNAs conserved within non-planthopper species were homologous with planthopper species. The novel miRNAs identified in this study provide a better understanding of the sRNA and the regulatory role of miRNA in sexual dimorphism and alteration in the expression or function of miRNAs in the rice pest.

Scavenger Receptor SCARA5 Acts as an HMGB1 Recognition Molecule Negatively Involved in HMGB1-Mediated Inflammation in Fish Models.

Scavenger receptor class A member 5 (SCARA5) and high-mobility group box 1 (HMGB1) protein have become increasingly attractive for their critical functions in innate inflammatory reactions and disorders. However, the functional relevance between these two molecules has never been described. This study discovered that SCARA5 is an HMGB1 recognition receptor that is negatively involved in HMGB1-mediated inflammation in pufferfish (Tetraodon nigroviridis) and zebrafish (Danio rerio) models. Hence, SCARA5 is added as a new member to the HMGB1 receptor family. Tetraodon HMGB1 (TnHMGB1) is a trafficking protein that can be secreted from the nucleus to the outside of cells upon CpG-oligodeoxynucleotide (ODN) stimulation. This protein exerts a strong synergistic effect on CpG-ODN-induced inflammation, as determined by the enhanced proinflammatory cytokine expression through coadministration of TnHMGB1 with CpG-ODN and impaired inflammatory responses through TnHMGB1 depletion. Tetraodon SCARA5 (TnSCARA5) is an inducible protein detected upon TnHMGB1 stimulation; this protein plays an inhibitory role in CpG-ODN-induced inflammation because TnSCARA5 overexpression suppresses cell responsiveness to CpG-ODN induction, whereas TnSCARA5 ablation intensifies the inflammatory reactions. TnSCARA5 can strongly associate with TnHMGB1 through the A and B boxes, depending on the redox state of the cysteine residues, but T box inhibits the association. TnSCARA5 mediates the endocytosis of TnHMGB1 into lysosomes. Results suggest that TnSCARA5 inhibits the CpG-ODN-mediated inflammation via the clearance of HMGB1 mediator for CpG-ODN stimulant. The above findings highlight a novel regulatory mechanism underlying innate inflammation and provide new insights into the clinical treatment of HMGB1-mediated diseases.

Characterization of SIGIRR/IL-1R8 Homolog from Zebrafish Provides New Insights into Its Inhibitory Role in Hepatic Inflammation.

Single Ig IL-1R-related molecule (SIGIRR, also called IL-1R8 or Toll/IL-1R [TIR]8), a negative regulator for Toll/IL-1R signaling, plays critical roles in innate immunity and various diseases in mammals. However, the occurrence of this molecule in ancient vertebrates and its function in liver homeostasis and disorders remain poorly understood. In this study, we identified a SIGIRR homology from zebrafish (Danio rerio [DrSIGIRR]) by using a number of conserved structural and functional hallmarks to its mammalian counterparts. DrSIGIRR was highly expressed in the liver. Ablation of DrSIGIRR by lentivirus-delivered small interfering RNA in the liver significantly enhanced hepatic inflammation in response to polyinosinic-polycytidylic acid [poly(I:C)] stimulation, as shown by the upregulation of inflammatory cytokines and increased histological disorders. In contrast, depletion of TIR domain-containing adaptor inducing IFN-ß (TRIF) or administration of TRIF signaling inhibitor extremely abrogated the poly(I:C)-induced hepatic inflammation. Aided by the zebrafish embryo model, overexpression of DrSIGIRR in vivo significantly inhibited the poly(I:C)- and TRIF-induced NF-κB activations; however, knockdown of DrSIGIRR promoted such activations. Furthermore, pull-down and Duolink in situ proximity ligation assay assays showed that DrSIGIRR can interact with the TRIF protein. Results suggest that DrSIGIRR plays an inhibitory role in TRIF-mediated inflammatory reactions by competitive recruitment of the TRIF adaptor protein from its TLR3/TLR22 receptor. To our knowledge, this study is the first to report a functional SIGIRR homolog that existed in a lower vertebrate. This molecule is essential to establish liver homeostasis under inflammatory stimuli. Overall, the results will enrich the current knowledge about SIGIRR-mediated immunity and disorders in the liver.

TET2 plays an essential role in erythropoiesis by regulating lineage-specific genes via DNA oxidative demethylation in a zebrafish model.

Although epigenetic modulation is critical for a variety of cellular activities, its role in erythropoiesis remains poorly understood. Ten-eleven translocation (TET) molecules participate in methylcytosine (5mC) hydroxylation, which results in DNA demethylation in several biological processes. In this research, the role of TETs in erythropoiesis was investigated by using the zebrafish model, where three TET homologs were identified. These homologs share conserved structural domains with their mammalian counterparts. Zebrafish TETs mediate the conversion of 5mC to hydroxymethylcytosine (5hmC) in zebrafish embryos, and the deletion of TET2 inhibits erythropoiesis by suppressing the expression of the scl, gata-1, and cmyb genes. TET2-upregulated lineage-specific genes and erythropoiesis are closely associated with the occurrence of 5hmC and demethylation in the intermediate CpG promoters (ICPs) of scl, gata-1, cmyb, which frequently occur at specific regions or CpG sites of these ICPs. Moreover, TET2 regulates the formation and differentiation of erythroid progenitors, and deletion of TET2 leads to erythrocyte dysplasia and anemia. Here, we preliminarily proved that TET2 plays an essential role in erythrocyte development by regulating lineage-specific genes via DNA oxidative demethylation. This report is anticipated to broaden current information on hematopoiesis and pathogenesis of hematopoiesis-related diseases.

Clinical evaluation of oral levofloxacin 500 mg once-daily dosage for treatment of lower respiratory tract infections and urinary tract infections: a prospective multicenter study in China.

Levofloxacin (LVFX), a fluoroquinolone agent, has a broad spectrum that covers Gram-positive and -negative bacteria and atypical pathogens. It demonstrates good clinical efficacy in the treatment of various infections, including lower respiratory tract infections (LRTIs) and urinary tract infections (UTIs). To evaluate the efficacy and safety of oral LVFX 500 mg once daily, a large open-label clinical trial was conducted in 1266 patients (899 with LRTIs and 367 with UTIs) at 32 centers in China. In the per-protocol population, the clinical efficacy rate (cure or improvement) at 7 to 14 days after the end of treatment was 96.4% (666/691) for LRTIs and 95.7% (267/279) for UTIs. In 53 patients diagnosed with atypical pneumonia the treatment was effective. The bacteriological efficacy rate was 96.6% (256/265) for LRTIs and 93.3% (126/135) for UTIs. The eradication rate of the causative pathogens was 100% (33/33) for Haemophilus influenzae and 96.0% (24/25) for Streptococcus pneumoniae in LRTIs, and 94.1% (80/85) for Escherichia coli in UTIs. The overall efficacy rates were 89.3% (617/691) for LRTIs and 87.8% (245/279) for UTIs. The incidence of drug-related adverse events (ADRs) was 17.3% (215/1245), and the incidence of drug-related laboratory abnormalities was 15.7% (191/1213). Common ADRs were dizziness, nausea, and insomnia. Common laboratory abnormalities included "WBC decreased", "alanine aminotransferase (ALT) increased", "aspartate aminotransferase (AST) increased", and "lactate dehydrogenase (LDH) increased". All of these events were mentioned in the package inserts of fluoroquinolones including LVFX, and most events were mild and transient. Thirty-four patients (2.7%) were withdrawn from the study because of the ADRs. No new ADRs were found. This study concluded that the dosage regimen of LVFX 500 mg once daily was effective and tolerable for the treatment of LRTIs and UTIs.