Interleukin 28A aggravates Con A-induced acute liver injury by promoting the recruitment of M1 macrophages.

Immune-mediated acute hepatic injury is characterized by the destruction of a large number of hepatocytes and severe liver function damage. Interleukin-28A (IL-28A), a member of the IL-10 family, is notable for its antiviral properties. However, despite advances in our understanding of IL-28A, its role in immune-mediated acute injury remains unclear. The present study investigated the role of IL-28A in concanavalin A (Con A)-induced acute immune liver injury. After Con A injection in mice, IL-28A level significantly increased. IL-28A deficiency was found to protect mice from acute liver injury, prolong survival time, and reduce serum aspartate aminotransferase and alanine aminotransferase levels. In contrast, recombinant IL-28A aggravated liver injury in mice. The proportion of activated M1 macrophages was significantly lower in the IL-28A-deficiency group than in the wild-type mouse group. In adoptive transfer experiments, M1 macrophages from WT could exacerbate mice acute liver injury symptoms in the IL-28A deficiency group. Furthermore, the expression of proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), IL-12, IL-6, and IL-1ß, by M1 macrophages decreased significantly in the IL-28A-deficiency group. Western blotting demonstrated that IL-28A deficiency could limit M1 macrophage polarization by modulating the nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK), and interferon regulatory factor (IRF) signaling pathways. In summary, IL-28A deletion plays an important protective role in the Con A-induced acute liver injury model and IL-28A deficiency inhibits the activation of M1 macrophages by inhibiting the NF-κB, MAPK, and IRF signaling pathways. These results provide a potential new target for the treatment of immune-related hepatic injury.

Hemin@carbon dot hybrid nanozymes with peroxidase mimicking properties for dual (colorimetric and fluorometric) sensing of hydrogen peroxide, glucose and xanthine.

The multifunctional hemin@carbon dot hybrid nanozymes (hemin@CD) with simultaneous peroxidase-like activity and fluorescence signalling property was prepared for the first time. Based on these properties, hemin@CD was applied to develop a dual-channel fluorescent probe for H2O2 and H2O2-based biocatalytic systems. By virtue of the peroxidase-like activity, hemin@CD can catalyze the oxidative coupling of 4-aminoantipyrine with phenol in the presence of H2O2 to form a pink-red quinoneimine dye with a maximum absorbance at 505 nm. Under the excitation wavelength of 480 nm, the green fluorescence of hemin@CD peaks at 540 nm and is quenched by the generated quinoneimine dye due to an inner filter effect, and also by H2O2 because of dynamic quenching. Thus, a colorimetric and fluorimetric dual-channel optical probe for H2O2 is obtained. Due to the glucose/xanthine transformations under formation of H2O2 by the relevant oxidase catalysis, the probe can be applied for detection of glucose and xanthine. The colorimetric detection limits for H2O2, glucose and xanthine are 0.11, 0.15, 0.11 µM, and the and fluorimetric detection limits are 0.15, 0.15, 0.12 µM, respectively. Graphical abstractSchematic representation of the colorimetric and fluorimetric dual probe for H2O2, glucose and xanthine based on the multifunctional emin@carbon dot) hybrid nanozymes with simultaneous peroxidase-like activity and fluorescence signalling property.

A putative triradial macrofossil from the Ediacaran Jiangchuan Biota.

The late Ediacaran Jiangchuan biota, from the Dengying Formation in eastern Yunnan, is well-known for its diverse macroalgal fossils, opening a window onto eukaryotic-dominated ecosystems from the late Neoproterozoic of South China. Although multiple lines of evidence suggest that metazoans had already evolved by the late Ediacaran, animal fossils have not yet been formally described from this locality. Here, we report a putative disc-shaped macrofossil from the Jiangchuan biota, Lobodiscus tribrachialis gen. et sp. nov. This specimen shows the triradial symmetry characteristic of trilobozoans, a group of Ediacaran macrofossils previously documented in Australia and Russia. Lobodiscus could record the youngest known occurrence of trilobozoans, strengthening taxonomic and ecological continuities between the Ediacaran "White Sea" and "Nama" assemblages. Our findings may expand the known paleogeographical distribution of trilobozoans and provide data for Ediacaran biostratigraphic correlations across the Yangtze block and globally, helping to track the diversification of early metazoan-grade organisms.

[Characterization of Metal Elements in Atmospheric PM2.5 and Health Risk Assessment in Heze in Winter from 2017 to 2018].

Atmospheric PM2.5 samples were collected in Heze, Shandong Province, from a total of three sampling sites at Heze College, Huarun Pharmacy, and a wastewater treatment plant between October 15, 2017 and January 31, 2018, to determine the concentrations of 21 metal elements in PM2.5 using inductively coupled plasma mass spectrometry (ICP-MS). The degree of elemental enrichment was also discussed, the health risks and potential heavy metal ecological risks were assessed. The results showed that ρ (PM2.5) ranged from 26.7 to 284.1 µg·m-3 at the three sampling sites during the sampling period, and the concentration values did not differ significantly, all of which were at high pollution levels. The highest concentrations of K were found in the three sampling sites, accounting for 31.03%, 39.47%, and 38.43% of the total, respectively, mainly due to the high contribution of biomass burning in autumn and winter in Heze, a large agricultural city. The highest concentrations of Zn, 89.70, 84.21, and 67.68 ng·m-3, were found in the trace elements at the three sampling sites, respectively. The enrichment factor results showed that the enrichment factor values of Zn, Pb, Sn, Sb, Cd, and Se were higher than 100, among which the enrichment factors of Cd and Se were higher than 2 000 and 4 000, respectively, which were significantly influenced by anthropogenic activities and might have been related to industrial production, metal smelting, road sources, and coal combustion emissions. The health risk results showed that there was some potential non-carcinogenic risk (HQ>0.1 for children and adults) for As and a combined potential non-carcinogenic risk (HI>0.1) and some potential carcinogenic risk (CRT>1×10-6) for both children and adults at the three sampling sites. There was a more significant carcinogenic risk (CRT>1×10-4) for adults at the wastewater treatment plant, and the slightly higher carcinogenic risk for adults than that for children may have been related to the longer outdoor activity and higher PM2.5 exposure for adults. The elements with the highest potential ecological risk values were Cd, As, and Pb, with Cd exhibiting a very high potential ecological risk that should be taken seriously. All three sampling sites showed a very high combined potential ecological risk, with the intensity spatially expressed as Heze College>Huarun Pharmacy>wastewater treatment plant.

Arachidonic acid released by PIK3CA mutant tumor cells triggers malignant transformation of colonic epithelium by inducing chromatin remodeling.

Key gene mutations are essential for colorectal cancer (CRC) development; however, how the mutated tumor cells impact the surrounding normal cells to promote tumor progression has not been well defined. Here, we report that PIK3CA mutant tumor cells transmit oncogenic signals and result in malignant transformation of intestinal epithelial cells (IECs) via paracrine exosomal arachidonic acid (AA)-induced H3K4 trimethylation. Mechanistically, PIK3CA mutations sustain SGK3-FBW7-mediated stability of the cPLA2 protein, leading to the synthetic increase in AA, which is transported through exosome and accumulated in IECs. Transferred AA directly binds Menin and strengthens the interactions of Menin and MLL1/2 methyltransferase. Finally, the combination of VTP50469, an inhibitor of the Menin-MLL interaction, and alpelisib synergistically represses PDX tumors harboring PIK3CA mutations. Together, these findings unveil the metabolic link between PIK3CA mutant tumor cells and the IECs, highlighting AA as the potential target for the treatment of patients with CRC harboring PIK3CA mutations.

Effects of mental rotation on map representation in orienteers-behavioral and fNIRS evidence.

Objective: Taking orienteering as an example, this study aimed to reveal the effects of mental rotation on orienteers' map representation and their brain processing characteristics. Methods: Functional near-infrared spectroscopic imaging (fNIRS) was used to explore the behavioral performance and cortical oxyhemoglobin concentration changes of map-represented cognitive processing in orienteering athletes under two task conditions: normal and rotational orientation. Results: Compared to that in the normal orientation, athletes' task performance in the rotated orientation condition was significantly decreased, as evidenced by a decrease in correct rate and an increase in reaction time; in the normal orientation condition, blood oxygen activation in the dorsolateral prefrontal lobe was significantly greater than that in the ventral prefrontal lobe, which was significantly correlated with the correct rate. With rotating orientation, the brain oxygen average of each region of interest was enhanced, and the brain region specifically processed was the ventral prefrontal lobe, specifically correlating with the correct rate. Conclusions: Mental rotation constrains the map representation ability of athletes, and map representation in rotational orientation requires more functional brain activity for information processing. Ventral lateral prefrontal lobe activation plays an important role in the map representation task in rotational orientation.

Interleukin-37 is involved in the immunopathogenesis of infectious mononucleosis.

BACKGROUND: Multiple immunopathological responses to viruses are observed in infectious mononucleosis (IM), a manifestation of primary infection with Epstein-Barr virus (EBV). Protective effects of the negative immunoregulatory molecule interleukin-37 (IL-37) have been observed in various bacterial and viral infections. However, the function of IL-37 in IM remains unknown. METHODS: Flow cytometry and enzyme-linked immunosorbent assay (ELISA) were used to determine the expression of IL-37 in the peripheral blood of patients diagnosed with IM, and the variation of lymphocyte subsets. Furthermore, the associations between IL-37 expression and the percentage of lymphocyte subgroups were analyzed. RESULTS: Patients with IM had severe immune dysfunction. The control group had a lower expression of IL-37 than the patients with IM. There were significant associations between IL-37 expression and both the proportion of CD3+T cells and the ratio of CD3+CD4+ to CD3+CD8+T cells. Patients with higher levels of IL-37 expression had lower levels of the liver inflammation indicators, alanine aminotransferase (ALT) and aspartate aminotransferase (AST). CONCLUSIONS: IL-37 may affect the immune pathogenesis of patients with IM infected with EBV, and may have immunotherapeutic benefit for EBV-associated illnesses.

In Situ Reconstructed Mo-doped Amorphous FeOOH Boosts the Oxygen Evolution Reaction.

Developing a fast and highly active oxygen evolution reaction (OER) catalyst to change energy kinetics technology is essential for making clean energy. Herein, we prepare three-dimensional (3D) hollow Mo-doped amorphous FeOOH (Mo-FeOOH) based on the precatalyst MoS2 /FeC2 O4 via in situ reconstruction strategy. Mo-FeOOH exhibits promising OER performance. Specifically, it has an overpotential of 285 mV and a durability of 15 h at 10 mA cm-2 . Characterizations indicate that Mo was included inside the FeOOH lattice, and it not only modifies the electronic energy levels of FeOOH but also effectively raises the inherent activity of FeOOH for OER. Additionally, in situ Raman analysis indicates that FeC2 O4 gradually transforms into the FeOOH active site throughout the OER process. This study provides ideas for designing in situ reconstruction strategies to prepare heteroatom doping catalysts for high electrochemical activity.

MicroRNA-146b protects kidney injury during urinary tract infections by modulating macrophage polarization.

Urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) can lead to severe kidney injury. However, the molecular mechanisms underlying the pathological process of kidney injury are still incompletely understood. In the present study, we demonstrate that microRNA-146b (miR-146b) deficiency aggravates kidney injury during UTIs caused by UPEC. In a mouse kidney infection model utilizing urosepsis isolate CFT073, we found that miR-146b expression significantly increased in the early stages of UPEC infection. Also, miR-146b-deficient mice displayed exacerbated inflammation in the kidney injury with severe M1 macrophage infiltration. Additionally, the results showed that miR-146b targeted interferon regulatory factor 5-regulated M1 macrophage polarization during UTIs. The results suggested that miR-146b contributed significantly to the control of kidney damage during UTIs, highlighting that miR-146b might be used as a novel therapeutic target for treating kidney injury during UTIs. IMPORTANCE Kidney injury during acute urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) is an important public health problem. However, how kidney injury develops during UPEC infection is still unclear. Although antibiotic therapy is currently an effective treatment for UTI, it cannot avoid kidney injury. MicroRNAs have gained extensive attention as essential molecules capable of regulating the autoimmune response. Among these, microRNA-146b (miR-146b) is involved in regulating inflammatory responses. In the present study, we demonstrated that miR-146b played an essential role in the development of kidney injury during UTIs caused by UPEC. The results showed that miR-146b may suppress M1 macrophage polarization and alleviate acute kidney injury. Furthermore, the miR-146b activator, agomir, in order to upregulate miR-146b, was effective in treating kidney damage by inhibiting the activation of M1 macrophages. In conclusion, our findings elucidated the mechanisms by which miR-146b alleviated kidney injury induced by UTIs, shed new light on the relationship between microRNA and bacterial infection, and provided a novel therapeutic target for treating this common bacterial infection.

Pyruvate Dehydrogenase Kinase 2 Accelerates Endotoxin Shock by Promoting Mitogen-Activated Protein Kinase Activation.

Endotoxin shock remains one of the major causes of mortality worldwide. Pyruvate dehydrogenase kinase (PDK) 2 is an important regulatory enzyme involved in glucose metabolism. The purpose of this study was to determine the regulatory effect of PDK2 on LPS-induced endotoxin shock and explore the mechanisms in vivo and in vitro. Here, we showed that PDK2 contributed to Toll-like receptor (TLR)-mediated inflammation. Lipopolysaccharide (LPS) activation of TLR4 pathways resulted in PDK2 upregulation in macrophages and dendritic cells (DCs). PDK2 overexpression enhanced TLR4 signaling pathway activation, whereas downregulating PDK2 expression inhibited TLR4 signaling pathway activation. Pharmacological inhibition of PDK2 significantly decreased the mortality rate and alleviated pathological injury in the lungs and livers of LPS-challenged mice, while significantly suppressing proinflammatory cytokine production. Thus, we confirmed that PDK2 is involved in LPS-induced endotoxin shock by modulating TLR4-mitogen-activated protein kinase signaling and inducing the production of proinflammatory cytokines in macrophages and DCs. Our findings highlight the importance of PDK2 as a novel target to treat septic shock.

A Characterization of Brain Area Activation in Orienteers with Different Map-Recognition Memory Ability Task Levels-Based on fNIRS Evidence.

BACKGROUND: Mapping memory ability is highly correlated with an orienteer's level, and spatial memory tasks of different difficulties can reveal the spatial cognitive characteristics of high-level athletes. METHODS: An "expert-novice" experimental paradigm was used to monitor behavioral performance and changes in cerebral blood oxygen concentration in orienteering athletes with tasks of different difficulty and cognitive load using functional near-infrared spectroscopic imaging (fNIRS). RESULTS: (1) there was no difference between high-/low-level athletes' map recognition and memory abilities in the non-orienteering scenario; (2) with increasing task difficulty, both high-/low-level athletes showed significantly decreasing behavioral performance, reduced correctness, longer reaction time, and strengthened cerebral blood oxygen activation concentration. There was no significant difference in L-DLPFC cerebral oxygen concentration between high-/low-level athletes in the simple map task, and the cerebral oxygen concentration in all brain regions was lower in the expert group than in the novice group in the rest of the task difficulty levels; (3) the correctness rate in the expert group in the complex task was closely related to the activation of the right hemisphere (R-DLPFC, R-VLPFC). CONCLUSIONS: Experts have a specific cognitive advantage in map-recognition memory, showing higher task performance and lower cerebral blood oxygen activation; cognitive load constrains map-recognition memory-specific ability and produces different performance effects and brain activation changes on spatial memory processing.

IL-37 isoform D acts as an inhibitor of soluble ST2 to boost type 2 immune homeostasis in white adipose tissue.

White adipose tissue (WAT) homeostasis substantiated by type 2 immunity is indispensable to counteract obesity and metabolic disorders. IL-33/suppression of tumorigenicity (ST) 2 signaling promotes type 2 response in WAT, while potential regulators remain to be discovered. We identified human IL-37 isoform D (IL-37D) as an effective trigger for ST2-mediated type 2 immune homeostasis in WAT. IL-37D transgene amplified ST2+ immune cells, promoted M2 macrophage polarization and type 2 cytokine secretion in WAT that mediate beiging and inflammation resolution, thereby increasing energy expenditure, reducing obesity and insulin resistance in high-fat diet (HFD)-fed mice. Mechanistically, either endogenous or exogenous IL-37D inhibited soluble ST2 (sST2) production from WAT challenged with HFD or TNF-α. Recombinant sST2 impaired the beneficial effects of IL-37D transgene in HFD-fed mice, characterized by damaged weight loss, insulin action, and type 2 cytokine secretion from WAT. In adipose-derived stem cells, IL-37D inhibited TNF-α-stimulated sST2 expression through IL-1 receptor 8 (IL-1R8)-dependent NF-κB inactivation. Collectively, human IL-37D suppresses sST2 to boost type 2 immune homeostasis in WAT, which may be a promising therapy target for obesity and metabolic disorders.

IL-37d Negatively Regulates NLRP3 Transcription via Receptor-mediated Pathway and Alleviates DSS-induced Colitis.

BACKGROUND: Interleukin-37 (IL-37) is a new negative immune regulator. It has 5 splicing forms, IL-37a-e, and most research mainly focuses on IL-37b functions in diverse diseases. Our previous research found that IL-37d inhibits lipopolysaccharide-induced inflammation in endotoxemia through a mechanism different from that of IL-37b. However, whether IL-37d plays a role in colitis and the underlying mechanisms is still obscure. Herein, we identified whether IL-37d regulates NLRP3 inflammasome activity and determined its effect on colitis. METHODS: NLRP3 inflammasome in macrophages from IL-37d transgenic (IL-37dtg) and control wild type (WT) mice were activated by lipopolysaccharide and adenosine 5'-triphosphate. The expression of NLRP3 inflammasome components and its downstream effector, IL-1ß, were detected by real-time polymerase chain reaction, western blot, and ELISA. The models of alum-induced peritonitis and dextran sodium sulfate (DSS)-induced colitis were used to investigate the function of IL-37d on regulating the activity of NLRP3 inflammasome in vivo. RESULTS: Our results showed that the activation of NLRP3 inflammasome in macrophage and alum-induced peritonitis was inhibited by IL-37d. Strikingly, IL-37d suppressed NLRP3 expression at the priming step via inhibiting NF-κB activation by transcriptional profiling. Moreover, the recombinant protein IL-37d attenuated NLRP3 inflammasome activation and the production of IL-1ß, which could be reversed by IL-1R8 knockdown. Finally, IL-37d transgenic mice resisted DSS-induced acute colitis and NLRP3 inflammasome activation. CONCLUSION: Interleukin-37d inhibits overactivation of the NLRP3 inflammasome through regulating NLRP3 transcription in an IL-1R8 receptor-mediated signaling pathway.

TNFAIP8L2/TIPE2 impairs autolysosome reformation via modulating the RAC1-MTORC1 axis.

Macroautophagy/autophagy is an evolutionarily conserved process that involves the selective degradation of cytoplasmic components within lysosomes in response to starvation. Autophagy is an ancient defense mechanism that has been closely integrated with the immune system and has multiple effects on innate and adaptive immunity. The pro-inflammatory and anti-inflammatory cytokines can activate and inhibit autophagy, respectively. TNFAIP8L2/TIPE2 (tumor necrosis factor, alpha-induced protein 8-like 2) is a newly identified immune negative regulator of innate and adaptive immunity that plays an important role in immune homeostasis. However, whether and how TNFAIP8L2 controls autophagy is still unknown. Murine TNFAIP8L2 can directly bind to and block the RAC1 GTPase activity to regulate innate immunity. RAC1 can also bind to MTOR and regulate MTORC1 cellular localization and activity. Here, we find that TNFAIP8L2 can compete with MTOR for binding to the GTP-bound state of RAC1 and negatively regulate MTORC1 activity. Interestingly, TNFAIP8L2 overexpression fails to induce autophagy flux by the suppression of the MTOR activity under glutamine and serum starvation. Instead, TNFAIP8L2 appears to impair autophagic lysosome reformation (ALR) during prolonged starvation. Finally, we demonstrate that TNFAIP8L2 overexpression leads to a defect in MTOR reactivation and disrupts autophagy flux, thereby leading to cell death. Furthermore, TNFAIP8L2 deficiency can exacerbate the inflammatory response and lung injury by controlling the MTOR activity in an LPS-induced mouse endotoxemia model. Our study reveals a novel role of TNFAIP8L2 in autophagy by regulating the RAC1-MTORC1 axis that supports its potential as a target for therapeutic treatment.Abbreviations: ALR: autophagic lysosome reformation; BafA1: bafilomycin A1; BMDMs: bone marrow-derived macrophages; Co-IP: Co-Immunoprecipitation; LAMP1: lysosomal associated membrane protein 1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MTORC1: mechanistic target of rapamycin kinase complex 1; RAPA: rapamycin; RPS6: ribosomal protein S6; SQSTM1/p62: sequestosome 1; Starv: Starvation; TNFAIP8L2/TIPE2: tumor necrosis factor-alpha-induced protein-8 like-2.

A Comorbid Rat Model of Neuroendocrine-Immune System Alterations Under the Impact of Risk Factors for Stroke.

Hypercholesterolemia and carotid atherosclerosis contribute to the etiology of stroke. However, there has been a lack of appropriate comorbid animal models incorporating some of the ubiquitous characteristics that precede strokes. Curcumin is a natural active polyphenolic compound extracted from the rhizoma of Curcuma longa L. which possesses comprehensive bioactivities. The present study aimed to evaluate whether neurobehavioral deficits, neuroendocrine-immune dysregulations and cerebral microcirculation dysfunction, are part of the initial stages of cerebral ischemia in individuals suffering from carotid atherosclerosis resulting from a high cholesterol diet (HCD) and if they could be tested using a comorbid animal model. Furthermore, the utility of this model will be examined following the administration of curcumin. Adult wild-type SD rats were fed a regular diet or HCD and supplemented with either vehicle or curcumin for 4 weeks. Carotid injury was induced by an air-drying endothelial denudation method at the end of the second week. Plasma cholesterol, carotid pathomorphology, neurobehavioral tests, and neuroendocrine-immune parameters were measured. We found higher plasma levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), intima and media (I/M) ratio, but lower high-density lipoprotein-cholesterol (HDL-C), spatial learning and memory capacity impairment, elevated NPY expression in the hypothalamus, increased plasma concentration of leptin, upregulated TNF-α, IL-1ß, and CRP in the circulation as well as TNF-α and IL-1ß in the cerebral cortex, plus enhanced ICAM-1, VCAM-1, and E-selectin in cerebral microvessels in HCD-fed model rats. All these alterations were ameliorated by curcumin. These results suggest that a comorbid rat model was effectively developed by HCD and carotid injury.

Toll-like Receptor 4 Inhibitor TAK-242 Improves Fulminant Hepatitis by Regulating Accumulation of Myeloid-Derived Suppressor Cell.

Fulminant hepatitis (FH) is an acute clinical disease with a poor prognosis and high mortality rate. The purpose of this study was to determine the protective effect of the Toll-like receptor 4 (TLR4) inhibitor TAK-242 on lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced explosive hepatitis and explore in vivo and in vitro mechanisms. Mice were pretreated with TAK-242 for 3 h prior to LPS (10 µg/kg)/D-GalN (250 mg/kg) administration. Compared to the LPS/D-GalN group, the TAK-242 pretreatment group showed significantly prolonged survival, reduced serum alanine aminotransferase and aspartate aminotransferase levels, relieved oxidative stress, and reduced inflammatory interleukin (IL)-6, IL-12, and tumor necrosis factor-α levels. In addition, TAK-242 increased the accumulation of myeloid-derived suppressor cells (MDSCs). Next, mice were treated with an anti-Gr-1 antibody to deplete MDSCs, and adoptive transfer experiments were performed. We found that TAK-242 protected against FH by regulating MDSCs. In the in vitro studies, TAK-242 regulated the accumulation of MDSCs and promoted the release of immunosuppressive inflammatory cytokines. In addition, TAK-242 inhibited protein expression of nuclear factor-κB and mitogen-activated protein kinases. In summary, TAK-242 had a hepatoprotective effect against LPS/D-GalN-induced explosive hepatitis in mice. Its protective effect may be involved in suppressing inflammation, reducing oxidative stress, and increasing the proportion of MDSCs.

Pyruvate Kinase M2 Contributes to TLR-Mediated Inflammation and Autoimmunity by Promoting Pyk2 Activation.

Toll-like receptors (TLRs) play critical roles in regulating the abnormal activation of the immune cells resulting in the pathogenesis of inflammation and autoimmune diseases. Pyruvate kinase M2 (PKM2), which governs the last step of glycolysis, is involved in multiple cellular processes and pathological conditions. However, little is known about the involvement of PKM2 in regulating TLR-mediated inflammation and autoimmunity. Herein, we investigated the role of PKM2 in the activation of the TLR pathways and the pathogenesis of inflammation and autoimmune diseases. The activation of TLR4, TLR7 and TLR9 pathways was found to induce the up-regulation of PKM2 expression in macrophages, dendritic cells (DCs) and B cells. The over-expression of PKM2 promotes the activation of TLR4, TLR7 and TLR9 pathways while interference with the PKM2 expression or the addition of the PKM2 inhibitor (PKM-IN) markedly inhibited the activation of TLR4, TLR7 and TLR9 pathways. Mechanistically, PKM2 augmented the activation of TLR4, TLR7 and TLR9 pathways by promoting the activation of the proline-rich tyrosine kinase 2 (Pyk2). Intriguingly, the PKM2 inhibitor PKM2-IN significantly protected the mice from the endotoxic shock mediated by the TLR4-agonist LPS. Additionally, it alleviated the progression in the TLR7-agonist imiquimod-mediated lupus mice and spontaneous lupus MRL/lpr mice. Moreover, PKM2 expression was highly elevated in the monocytes, DCs and B cells from systemic lupus erythematous (SLE) patients compared with those from the healthy donors. Besides, the PKM2 expression level was positively correlated with the degree of activation of these immune cells. In summary, PKM2 contributed to TLR-mediated inflammation and autoimmunity and can be a valuable target to control inflammation and autoimmunity.

Ursolic acid inhibits the invasiveness of A498 cells via NLRP3 inflammasome activation.

Renal cell cancer is a common malignant tumor of the urinary system. Ursolic acid (UA) serves an important antitumor role in certain types of cancer, such as lung cancer, breast cancer and hepatocellular carcinoma; however, to the best of our knowledge, the effect of UA on renal cancer has not yet been investigated. In the present study, A498 cells were treated with different concentrations of UA for 12, 24 and 48 h, and then MCC950, an inhibitor of the NLR family pyrin domain-containing 3 (NLRP3) receptor, was added to block NLRP3 signaling. The proliferation of A498 cells was analyzed using an MTS assay and invasiveness was analyzed using a Transwell assay. The expression levels of NLRP3, cleaved caspase-1, IL-1ß and MMP-2 were detected using western blotting. The present results demonstrated that the invasiveness of A498 cells was significantly decreased following UA treatment (P<0.05), while expression levels of NLRP3, cleaved caspase-1 and IL-1ß were significantly increased, and MMP-2 expression was decreased following UA stimulation (P<0.05). This was reversed by MCC950 treatment (P<0.05), with the exception of NLRP3. In conclusion, the present results indicated that UA exposure decreased the proliferation and invasiveness of A498 cells. Additionally, UA exposure significantly decreased MMP-2 production and induced the activation of NLRP3 inflammasome, which was reversed by MCC950 treatment, indicating that NLRP3 activation may be involved in UA inhibition of A498 cell invasiveness.

IL-37 isoform D downregulates pro-inflammatory cytokines expression in a Smad3-dependent manner.

IL-37 is a new member of IL-1 family and possesses five different isoforms (named as IL-37 a-e). IL-37b has been demonstrated as a physiological suppressor of immune responses. However, the function of other isoforms remains unknown. Here, we show that IL-37d possesses anti-inflammatory roles both in vitro and in vivo. Firstly, IL-37d is expressed in peripheral blood mononuclear cells (PBMCs) and umbilical cords-derived mesenchymal stem cells (UCMSCs). Secondly, IL-37d overexpression markedly inhibits IL-1ß-induced IL-6 production in A549 cells. Consistently, bone marrow-derived macrophages (BMDMs) from IL-37d transgenic mice express low levels of pro-inflammatory cytokines (such as IL-6 and TNF-α) following LPS stimulation, compared with those from wild-type mice. Furthermore, IL-37d transgenic mice produce less pro-inflammatory cytokines, and show much less degree of LPS-induced endotoxemia in vivo. Mechanistically, IL-37d interacts with Smad3 and promotes nuclear translocation of pSmad3. SIS3 (a specific Smad3 inhibitor) treatment completely blocks the inhibitory effects of IL-37d. Thus, our data indicate that IL-37d is a functional cytokine that negatively regulates pro-inflammatory cytokines expression in a Smad3-dependent manner.

Immunomodulatory effects of xanthan gum in LPS-stimulated RAW 264.7 macrophages.

In this study, we evaluated the immunomodulatory effects of xanthan gum (XG) in RAW264.7 macrophages and the underlying molecular mechanisms. We used scanning electron microscopy (SEM) to analyze the morphology of XG-treated RAW264.7 cells with and without lipopolysaccharide (LPS) stimulation and investigated the subsequent effects on nitric oxide (NO), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor (TNF-α), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) levels in LPS-activated mouse RAW264.7 macrophages. We also analyzed the binding affinity of XG to Toll-like receptor 4 (TLR4) with surface plasmon resonance (SPR) analysis and observed that XG decreased NO, IL-6 and TNF-α secretion into the culture medium and iNOS and COX-2 protein levels induced by LPS. This study reveals a two-way immunomodulatory effect of XG on inflammatory mediators in RAW264.7 macrophages that may involve the TLR4 signal pathway, providing a pharmacological basis for the use of XG in the control of inflammatory disorders.