Swimming Impacts on Pancreatic Inflammatory Cytokines, miR-146a and NF-кB Expression Levels in Type-2 Diabetic Rats

BACKGROUND

Obesity-induced chronic inflammation is a key component in the pathogenesis of insulin resistance and type-2 diabetes Objective: This study aimed to evaluate the effect of swimming exercise on pancreatic expression levels of inflammatory cytokines, miR-146a and NF-кB in type-2 diabetic male rats.

METHODS

Twenty- eight male Wistar rats were divided into four groups: control (Con), exercise, diabetes and diabetic exercise (n = 7). Diabetes induction performed by the combination of high-fat diet (HFD, 4 weeks) and streptozotocin (35 mg/kg. ip). After induction of diabetes, the rats swam in the exercise groups for 12 weeks. Then, blood and tissue samples were collected.

RESULTS

Our results indicated a significant increase in expression levels of miR-146, NF-κB and inflammatory cytokines (IL-6, TNF-α, and IL-1β) while a significant decrease in pancreatic expression levels of TRAF6 and IRAK1 in diabetic group as compared to the control group. In contrast, swimming exercise resulted in a significant decrease in expression levels of miR-146a, NF-кB and inflammatory cytokines and a significant increase in expression levels of TRAF6 and IRAK1 in the exercise-diabetic group compared to the diabetic group.

CONCLUSION

Our results indicated a significant increase in expression levels of miR-146, NF-κB and inflammatory cytokines (IL-6, TNF-α, and IL-1β) while a significant decrease in pancreatic expression levels of TRAF6 and IRAK1 in diabetic group as compared to the control group. In contrast, swimming exercise resulted in a significant decrease in expression levels of miR-146a, NF-кB and inflammatory cytokines and a significant increase in expression levels of TRAF6 and IRAK1 in the exercise-diabetic group compared to the diabetic group.

Inflammasome Activation Induced by a Snake Venom Lys49-Phospholipase A2 Homologue

Background: Snake venom phospholipases A₂ (PLA₂s) have hemolytic, anticoagulant, myotoxic, oedematogenic, bactericidal, and inflammatory actions. BthTX-I, a Lys49-PLA₂ isolated from Bothrops jararacussu venom, is an example of Lys49-PLA₂ that presents such actions. NLRP3 is a cytosolic receptor from the NLR family responsible for inflammasome activation via caspase-1 activation and IL-1β liberation. The study of NLRs that recognize tissue damage and activate the inflammasome is relevant in envenomation. Methods: Male mice (18–20 g) received an intramuscular injection of BthTX-I or sterile saline. The serum was collected for creatine-kinase (CK), lactate dehydrogenase (LDH), and interleukin-1β (IL-1β) assays, and muscle was removed for inflammasome activation immunoblotting and qRT-PCR expression for nucleotide and oligomerization domain, leucine-rich repeat-containing protein family, pyrin-containing domain 3 receptor (NLRP3) inflammasome components. Results: BthTX-I-induced inflammation and myonecrosis, shown by intravital microscope, and LDH and CK release, respectively. Mouse treatment with A438079, a P2X7 receptor antagonist, did not modify these effects. BthTX-I induced inflammasome activation in muscle, but P2X7R participation in this effect was not observed. Conclusion: Together, the results showed for the first time that BthTX-I in gastrocnemius muscle induces inflammation and consequently, inflammasome activation via NLRP3 with caspase-1 activation and IL-1β liberation.

Ephedra sinica Stapf and Gypsum Attenuates Heat-Induced Hypothalamic Inflammation in Mice

Ephedra sinica Stapf (EH) exert toxic effects, such as excitability, cardiac arrhythmia, and others. On the contrary, in traditional herbal medicine, EH and gypsum (GF) are used most often to treat symptoms caused by external stressors. The hypothalamus plays a crucial role in thermal homeostasis. Inflammatory response in the hypothalamus by thermal stressors may affect thermal and energy homeostasis. This study investigates the effect of EH and GF against heat-induced mouse model. Mice were divided into four groups: saline, saline plus heat, EH plus heat, and GF plus heat treated groups. Heat stress was fixed at 43 °C for 15 min once daily for 3 days. Weight and ear and rectal temperature measurements were made after terminating heat stress. Hypothalamus tissue was collected to evaluate the HSP70, nuclear factor kappa-Β (NF-kB), and interleukin (IL)-1β protein expression levels. EH and GF treatment suppressed the increased body temperature. EH significantly ameliorated heat-induced body weight loss, compared to gypsum. Regulatory effects of EH and GF for body temperature and weight against heat stress were mediated by IL-1β reduction. EH showed significant HSP70 and NF-kB inhibition against heat stress. EH and GF contribute to the inhibition of heat-induced proinflammatory factors and the promotion of hypothalamic homeostasis.

IL-1β-driven amyloid plaque clearance is associated with an expansion of transcriptionally reprogrammed microglia

BACKGROUND

Neuroinflammation is thought to contribute to the pathogenesis of Alzheimer's disease (AD), yet numerous studies have demonstrated a beneficial role for neuroinflammation in amyloid plaque clearance. We have previously shown that sustained expression of IL-1β in the hippocampus of APP/PS1 mice decreases amyloid plaque burden independent of recruited CCR2+ myeloid cells, suggesting resident microglia as the main phagocytic effectors of IL-1β-induced plaque clearance. To date, however, the mechanisms of IL-1β-induced plaque clearance remain poorly understood.

METHODS

To determine whether microglia are involved in IL-1β-induced plaque clearance, APP/PS1 mice induced to express mature human IL-1β in the hippocampus via adenoviral transduction were treated with the Aβ fluorescent probe methoxy-X04 (MX04) and microglial internalization of fibrillar Aβ (fAβ) was analyzed by flow cytometry and immunohistochemistry. To assess microglial proliferation, APP/PS1 mice transduced with IL-1β or control were injected intraperitoneally with BrdU and hippocampal tissue was analyzed by flow cytometry. RNAseq analysis was conducted on microglia FACS sorted from the hippocampus of control or IL-1β-treated APP/PS1 mice. These microglia were also sorted based on MX04 labeling (MX04+ and MX04- microglia).

RESULTS

Resident microglia (CD45loCD11b+) constituted > 70% of the MX04+ cells in both Phe- and IL-1β-treated conditions, and < 15% of MX04+ cells were recruited myeloid cells (CD45hiCD11b+). However, IL-1β treatment did not augment the percentage of MX04+ microglia nor the quantity of fAβ internalized by individual microglia. Instead, IL-1β increased the total number of MX04+ microglia in the hippocampus due to IL-1β-induced proliferation. In addition, transcriptomic analyses revealed that IL-1β treatment was associated with large-scale changes in the expression of genes related to immune responses, proliferation, and cytokine signaling.

CONCLUSIONS

These studies show that IL-1β overexpression early in amyloid pathogenesis induces a change in the microglial gene expression profile and an expansion of microglial cells that facilitates Aβ plaque clearance.

N-acetyl cysteine inhibits lipopolysaccharide-mediated synthesis of interleukin-1β and tumor necrosis factor-α in human periodontal ligament fibroblast cells through nuclear factor-kappa B signaling

BACKGROUND

The aim of this study was to investigate the role of n-acetyl cysteine (NAC) in the lipopolysaccharide (LPS)-mediated induction of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) synthesis by human periodontal ligament fibroblast cells (hPDLFs). In addition, we aimed to determine the involvement of the nuclear factor-kappa B (NF-κB) pathway in any changes in IL-1β and TNF-α expression observed in response to LPS and NAC.

METHODS

HPDLFs were obtained by primary culture. The culture medium used in this experiment was Dulbecco's Modified Eagle Medium (DMEM low-glucose). Cells were stimulated with various concentrations of NAC or LPS. Cell proliferation was measured at various time-points with the cell Counting Kit 8 (CCK-8) assay. mRNA levels of IL-1β and TNF-α were determined by real-time quantitative polymerase chain reaction (RT-qPCR) analysis. Protein levels of IL-1β and TNF-α were measured by enzyme-linked immunosorbent assay (ELISA). Protein and mRNA expression levels of NF-κB were measured by western blot and RT-qPCR.

RESULTS

The results showed that LPS treatment in hPDLFs induced mRNA and protein expression of IL-1β, TNF-α, and NF-κB. However, these effects were eliminated by pretreatment with NAC. Pretreatment with both NAC (1 mmol/L) and BAY11-7082 (10 μmol/L) significantly inhibited the NF-κB activity induced by LPS.

CONCLUSION

NAC inhibits the LPS-mediated synthesis of tumor TNF-α and IL-1β in hPDLFs, through the NF-κB pathway.

Season and size of urban particulate matter differentially affect cytotoxicity and human immune responses to Mycobacterium tuberculosis

Exposure to air pollution particulate matter (PM) and tuberculosis (TB) are two of the leading global public health challenges affecting low and middle income countries. An estimated 4.26 million premature deaths are attributable to household air pollution and an additional 4.1 million to outdoor air pollution annually. Mycobacterium tuberculosis (M.tb) infects a large proportion of the world's population with the risk for TB development increasing during immunosuppressing conditions. There is strong evidence that such immunosuppressive conditions develop during household air pollution exposure, which increases rates of TB development. Exposure to urban air pollution has been shown to alter the outcome of TB therapy. Here we examined whether in vitro exposure to urban air pollution PM alters human immune responses to M.tb. PM2.5 and PM10 (aerodynamic diameters <2.5μm, <10μm) were collected monthly from rainy, cold-dry and warm-dry seasons in Iztapalapa, a highly populated TB-endemic municipality of Mexico City with elevated outdoor air pollution levels. We evaluated the effects of seasonality and size of PM on cytotoxicity and antimycobacterial host immunity in human peripheral blood mononuclear cells (PBMC) from interferon gamma (IFN-γ) release assay (IGRA)+ and IGRA- healthy study subjects. PM10 from cold-dry and warm-dry seasons induced the highest cytotoxicity in PBMC. With the exception of PM2.5 from the cold-dry season, pre-exposure to all seasonal PM reduced M.tb phagocytosis by PBMC. Furthermore, M.tb-induced IFN-γ production was suppressed in PM2.5 and PM10-pre-exposed PBMC from IGRA+ subjects. This observation coincides with the reduced expression of M.tb-induced T-bet, a transcription factor regulating IFN-γ expression in T cells. Pre-exposure to PM10 compared to PM2.5 led to greater loss of M.tb growth control. Exposure to PM2.5 and PM10 collected in different seasons differentially impairs M.tb-induced human host immunity, suggesting biological mechanisms underlying altered M.tb infection and TB treatment outcomes during air pollution exposures.

Anti-Apoptotic Effects of Docosahexaenoic Acid in IL-1β-Induced Human Chondrosarcoma Cell Death through Involvement of the MAPK Signaling Pathway

Osteoarthritis (OA) is a degenerative disease characterized by progressive articular cartilage destruction and joint marginal osteophyte formation with different degrees of synovitis. Docosahexaenoic acid (DHA) is an unsaturated fatty acid with anti-inflammatory, antioxidant, and antiapoptotic functions. In this study, the human chondrosarcoma cell line SW1353 was cultured in vitro, and an OA cell model was constructed with inflammatory factor IL-1β stimulation. After cells were treated with DHA, cell apoptosis was measured. Western blot assay was used to detect protein expression of apoptosis-related factors (Bax, Bcl-2, and cleaved caspase-3) and mitogen-activated protein kinase (MAPK) signaling pathway family members, including extracellular signal-regulated kinase (ERK), c-JUN N-terminal kinase (JNK), and p38 MAPK. Our results show that IL-1β promotes the apoptosis of SW1353 cells, increases the expression of Bax and cleaved caspase-3, and activates the MAPK signaling pathway. In contrast, DHA inhibits the expression of IL-1β, inhibits IL-1β-induced cell apoptosis, and has a certain inhibitory effect on the activation of the MAPK signaling pathway. When the MAPK signaling pathway is inhibited by its inhibitors, the effects of DHA on SW1353 cells are weakened. Thus, DHA enhances the apoptosis of SW1353 cells through the MAPK signaling pathway.

Effects of NLRP6 in Cerebral Ischemia/Reperfusion (I/R) Injury in Rats

The NOD-like receptor protein 6 (NLRP6), an intracytoplasmic pattern recognition receptor in the nucleotide-binding domain, leucine-rich repeat-containing (NLR) innate immune receptor family, influences the inflammation reaction. The role of NLRP6 in cerebral ischemia-reperfusion (I/R) injury in rats is unclear. We explore the function of NLRP6 in cerebral I/R injury. The investigators used a middle cerebral artery occlusion/reperfusion model (MCAO) to imitate ischemic injury. We found the peak expression of NLRP6 is in 48-h post-cerebral I/R injury. The expression of NLRP6 siRNA, as well as the expression of protein and mRNA, was detected by Western blot and qRT-PCR. The degree of IL-1β and IL-18 was assessed by ELISA. After downregulating NLRP6, the expression of IL-1β, IL-18, cleaved Caspase-1, and myeloperoxidase (MPO) were reduced. In HE and Nissl staining, pathological injury of brain tissue after downregulating NLRP6 was improved. NLRP6 siRNA decreased the NLRP6-ASC binding states by CO-IP. NRP6 has a pro-inflammatory effect in cerebral I/R injury, which may provide a new target for the treatment of cerebral I/R injury.

Chaetocin attenuates gout in mice through inhibiting HIF-1α and NLRP3 inflammasome-dependent IL-1β secretion in macrophages

Chaetocin is a fungal metabolite that possesses a potential anti-inflammatory activity. Acute gout is a self-limiting inflammatory response to monosodium urate (MSU) crystals. However, the effect of cheatocin on gout has not been elucidated. In the study, we found that chaetocin could decrease MSU induced IL-1β secretion in bone marrow derived macrophages by several mechanisms, including inhibiting the activation of NLRP3 inflammasome. Chaetocin negatively regulated apoptosis-associated speck-like protein with a CARD domain oligomerization, and caspase-1 processing, key events during inflammasome activation. Furthermore, chaetocin restrain expressions of Hypoxia-inducible factor-1α and Hexokinase 2, mediators of glycolysis, which necessary for synthesis of pro-IL-1β during inflammasome priming. In vivo, chaetocin ameliorate MSU-induced arthritis, which showed as reduced local swelling and inflammatory cell infiltration. In MSU-induced peritonitis model, the peritoneal macrophages of chaetocin-pretreated mice showed significantly decreased mRNA levels of HIF-1α and NLRP3 related genes. These findings suggested that chaetocin has a potent anti-inflammatory effect against gout. More importantly, it is proposed that the inhibiting of glycolysis pathway would be a new avenue for the treatment of gout flare and other IL-1β related diseases.

Chemistry and immunostimulatory activity of a polysaccharide from Undaria pinnatifida

An immunologically active polysaccharide named as UPP-2 (1035.52 kDa) was isolated from Undaria pinnatifida using traditional water extraction followed by DEAE Sepharose fast flow chromatography. UPP-2 was proven to be a low sulfated polysaccharide with relatively abundant uronic acid (13.08 ± 0.67%). UPP-2 mainly consisted of xylose (64.55%), glucose (23.81%), arabinose (5.90%) and mannose (4.26%), and its main glycosidic linkage types included →2)-α-D-Xylp-(1→, →4)-α-D-Glcp-(1→, α-D-Xylp-(1→ and →2,4)-β-D-Xylp-(1 → . Results indicated that UPP-2 significantly promoted the proliferation and pinocytic capacity of RAW264.7 cells, and upregulated the mRNA expressions of iNOS, TNF-α, IL-6 and IL-1β at 100-600 μg/mL with a maximum of 195, 42, 768 and 539 times of those of the negative control, respectively. Moreover, UPP-2 significantly increased the secretions of nitric oxide, TNF-α and IL-6 at 100-600 μg/mL (8.0, 73.1 and 188.7 times compared to those of the negative control, respectively), as well as promoted the production of IL-1β obviously at 600 μg/mL. Overall, UPP-2 could be served as a potential dietary supplement or functional food based on its immunostimulatory activity.

Consequences of interleukin 1β-triggered chronic inflammation in the mouse prostate gland: Altered architecture associated with prolonged CD4+ infiltration mimics human proliferative inflammatory atrophy

BACKGROUND

Elevated expression of the proinflammatory cytokine interleukin 1β (IL-1β) has been observed in expressed prostatic secretions of patients with chronic prostatitis/chronic pelvic pain syndrome, and genetic polymorphisms associated with the IL1B gene are linked to increased risk for aggressive prostate cancer.

METHODS

To study the role of IL-1β expression in prostate inflammation, we examined IL1B expression in human prostatic proliferative inflammatory atrophy (PIA) lesions and developed a tetracycline-regulated human IL1B transgene in the mouse prostate.

RESULTS

Here, we demonstrate that IL1B expression is a common finding in human PIA lesions, which harbored focal IL1B expression in epithelial and stromal compartments. Human IL1B expression in the mouse prostate elicited acute and chronic inflammation. Penetrance and expressivity were variable and tunable by altering transgene dosage and the presence of an exogenous inducible marker antigen (green fluorescent protein). Inflammation was characterized by infiltration of CD4+ T cells, demonstrating an adaptive immune response. Chronic inflammation persisted after doxycycline (Dox) withdrawal. Reactive epithelia increased expression of downstream cytokines, and altered glandular architecture was observed upon sustained induction of IL1B. Immunohistochemical analyses revealed a higher proliferative index and decreased Nkx3.1 expression in inflamed mouse prostates.

CONCLUSIONS

These data implicate IL-1β in human prostate pathology and this model provides a versatile platform to interrogate molecular mechanisms of inflammation-associated prostate pathologies associated with episodic or sustained IL-1β expression.

HIF-1α regulates IL-1β and IL-17 in sarcoidosis

Sarcoidosis is a complex systemic granulomatous disease of unknown etiology characterized by the presence of activated macrophages and Th1/Th17 effector cells. Data mining of our RNA-Seq analysis of CD14⁺monocytes showed enrichment for metabolic and hypoxia inducible factor (HIF) pathways in sarcoidosis. Further investigation revealed that sarcoidosis macrophages and monocytes exhibit higher protein levels for HIF-α isoforms, HIF-1β, and their transcriptional co-activator p300 as well as glucose transporter 1 (Glut1). In situ hybridization of sarcoidosis granulomatous lung tissues showed abundance of HIF-1α in the center of granulomas. The abundance of HIF isoforms was mechanistically linked to elevated IL-1β and IL-17 since targeted down regulation of HIF-1α via short interfering RNA or a HIF-1α inhibitor decreased their production. Pharmacological intervention using chloroquine, a lysosomal inhibitor, decreased lysosomal associated protein 2 (LAMP2) and HIF-1α levels and modified cytokine production. These data suggest that increased activity of HIF-α isoforms regulate Th1/Th17 mediated inflammation in sarcoidosis.

Melatonin attenuates TNF-α and IL-1β expression in synovial fibroblasts and diminishes cartilage degradation: Implications for the treatment of rheumatoid arthritis

The hormone melatonin has many properties, including antioxidant, anti-inflammatory, and immunomodulatory effects. Melatonin has been demonstrated to be beneficial in several inflammatory autoimmune diseases, but its effects in rheumatoid arthritis (RA) remain controversial. We sought to determine how melatonin regulates inflammation in RA. We found that melatonin dose-dependently inhibits tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β expression through the PI3K/AKT, ERK, and NF-κB signaling pathways. We also identified that melatonin inhibits TNF-α and IL-1β production by upregulating miR-3150a-3p expression. Synovial tissue specimens from RA patients and culture of human rheumatoid fibroblast-like synoviocytes confirmed that the MT1 receptor is needed for the anti-inflammatory activities of melatonin. Importantly, melatonin also significantly reduced paw swelling, cartilage degradation, and bone erosion in the collagen-induced arthritis mouse model. Our results indicate that melatonin ameliorates RA by inhibiting TNF-α and IL-1β production through downregulation of the PI3K/AKT, ERK, NF-κB signaling pathways, as well as miR-3150a-3p overexpression. The role of melatonin as an adjuvant treatment in patients with RA deserves further clinical studies.

Potential Role of H-Ferritin in Mitigating Valvular Mineralization

Objective- Calcific aortic valve disease is a prominent finding in elderly and in patients with chronic kidney disease. We investigated the potential role of iron metabolism in the pathogenesis of calcific aortic valve disease. Approach and Results- Cultured valvular interstitial cells of stenotic aortic valve with calcification from patients undergoing valve replacement exhibited significant susceptibility to mineralization/osteoblastic transdifferentiation in response to phosphate. This process was abrogated by iron via induction of H-ferritin as reflected by lowering ALP and osteocalcin secretion and preventing extracellular calcium deposition. Cellular phosphate uptake and accumulation of lysosomal phosphate were decreased. Accordingly, expression of phosphate transporters Pit1 and Pit2 were repressed. Translocation of ferritin into lysosomes occurred with high phosphate-binding capacity. Importantly, ferritin reduced nuclear accumulation of RUNX2 (Runt-related transcription factor 2), and as a reciprocal effect, it enhanced nuclear localization of transcription factor Sox9 (SRY [sex-determining region Y]-box 9). Pyrophosphate generation was also increased via upregulation of ENPP2 (ectonucleotide pyrophosphatase/phosphodiesterase-2). 3H-1, 2-dithiole-3-thione mimicked these beneficial effects in valvular interstitial cell via induction of H-ferritin. Ferroxidase activity of H-ferritin was essential for this function, as ceruloplasmin exhibited similar inhibitory functions. Histological analysis of stenotic aortic valve revealed high expression of H-ferritin without iron accumulation and its relative dominance over ALP in noncalcified regions. Increased expression of H-ferritin accompanied by elevation of TNF-α (tumor necrosis factor-α) and IL-1β (interleukin-1β) levels, inducers of H-ferritin, corroborates the essential role of ferritin/ferroxidase via attenuating inflammation in calcific aortic valve disease. Conclusions- Our results indicate that H-ferritin is a stratagem in mitigating valvular mineralization/osteoblastic differentiation. Utilization of 3H-1, 2-dithiole-3-thione to induce ferritin expression may prove a novel therapeutic potential in valvular mineralization.

IL-1β expression is increased and regulates GABA transmission following chronic ethanol in mouse central amygdala

The interleukin-1 system (IL-1) is a prominent pro-inflammatory pathway responsible for the initiation and regulation of immune responses. Human genetic and preclinical studies suggest a critical role for IL-1β signaling in ethanol drinking and dependence, but little is known about the effects of chronic ethanol on the IL-1 system in addiction-related brain regions such as the central amygdala (CeA). In this study, we generated naïve, non-dependent (Non-Dep) and dependent (Dep) male mice using a paradigm of chronic-intermittent ethanol vapor exposure interspersed with two-bottle choice to examine 1) the expression of IL-1β, 2) the role of the IL-1 system on GABAergic transmission, and 3) the potential interaction with the acute effects of ethanol in the CeA. Immunohistochemistry with confocal microscopy was used to assess expression of IL-1β in microglia and neurons in the CeA, and whole-cell patch clamp recordings were obtained from CeA neurons to measure the effects of IL-1β (50 ng/ml) or the endogenous IL-1 receptor antagonist (IL-1ra; 100 ng/ml) on action potential-dependent spontaneous inhibitory postsynaptic currents (sIPSCs). Overall, we found that IL-1β expression is significantly increased in microglia and neurons of Dep compared to Non-Dep and naïve mice, IL-1β and IL-1ra bi-directionally modulate GABA transmission through both pre- and postsynaptic mechanisms in all three groups, and IL-1β and IL-1ra do not alter the facilitation of GABA release induced by acute ethanol. These data suggest that while ethanol dependence induces a neuroimmune response in the CeA, as indicated by increased IL-1β expression, this does not significantly alter the neuromodulatory role of IL-1β on synaptic transmission.

Molecular mechanisms of biogenesis of apoptotic exosome-like vesicles and their roles as damage-associated molecular patterns

Recent research has led to contradictory notions regarding the conventional theory that apoptotic cell death can evoke inflammatory or immunogenic responses orchestrated by released damage-associated patterns (DAMPs). By inducing IL-1β from bone marrow-derived macrophages in an effort to determine the inflammatory mediators released from apoptotic cells, we found that exosomal fractions called "apoptotic exosome-like vesicles" (AEVs) prepared from apoptotic-conditioned medium were the main inflammatory factors. These AEVs showed characteristics of exosomes in their size, density, morphology, and protein expression but had unique marker proteins, sphingosine-1-phosphate receptors 1 and 3 (S1PR1 and 3). Their biogenesis was completely dependent on cellular sphingosine-1-phosphate (S1P)/S1PRs signaling from multiple fine spindles of plasma membrane accompanied by F-actin, S1PR1, S1PR3, and CD63 at the early apoptotic phase and progressing to the maturation of F-actin-guided multivesicular endosomes mediated by Gβγ subunits of S1PRs downstream. S1P-loaded S1PRs on AEVs were critical factors for inducing IL-1β via NF-κB transcriptional factor and p38 MAPK, possibly through the RHOA/NOD2 axis, in differentiating macrophages. The AEVs induced genes of proinflammatory cytokines, chemokines, and mediators in both in vitro and in vivo models. In conclusion, AEVs could be key inflammatory mediators, acting as DAMPs that could explain the pathogeneses of various chronic inflammations, autoimmune diseases, or cancers in the future.

Inhibitory effect of Saposhnikovia divaricate polysaccharide on fibroblast-like synoviocytes from rheumatoid arthritis rat in vitro

To study the mechanism and inhibitory effect of Saposhnikovia divaricata polysaccharide (SDP) on fibroblast-like synoviocytes (FLS) isolated from rheumatoid arthritis rat model. Rheumatoid arthritis rat model was established by the classical composite factors including wind, cold, damp plus biological agents. The synovial tissues were digested with trypsin to isolate FLS cells. The different dosage of SDP was applied in culture. The cell viability was evaluated by MTT assay and the apoptosis was determined by analytic flow cytometry. The expression change of p53 gene was monitored by RT-PCR method. The production of secretory inflammation factors TNF-α and IL-1β were determined by ELISA. The proliferative and apoptotic proteins such as Bcl-2, Bax, Caspase-3, MMP-1, MMP-3, P53 were measured by western blotting. Our data demonstrated that treatment with high concentration of SDP could enhance the expression of P53 at both mRNA (P<0.05) and protein (P<0.05) level, inhibit the secretion of TNF-α (P<0.05) and IL-1β (P<0.05). Simultaneously, the Bcl-2/Bax ratio and level of MMP-1, MMP-3 was significantly decreased, and apoptotic marker caspase-3 protein was increased. In addition, the FACS analysis consistently consolidated the apoptosis-inducing effect of SDP on RAFLS. SDP could significantly inhibit dysplasia of RAFLS via modulation of p53 expression and suppression of inflammatory factors, which suggested a potential therapeutic value for rheumatoid arthritis.

The aqueous extract of Phellinus igniarius (SH) ameliorates dextran sodium sulfate-induced colitis in C57BL/6 mice

Phellinus igniarius, which is called Sanghuang in Chinese, is a fungal herb widely used in Traditional Chinese Medicine to treat stomachache, inflammation and tumors. Recent studies have demonstrated the antitumor, anti-diabetic, anti-inflammatory and immunity-modulating activities of P. igniarius. In the present study, we investigated that ameliorating effect of the aqueous extract of P. igniarius fruiting body (SH) on dextran sodium sulfate (DSS)-induced colitis in C57BL/6 mice. Treatment with SH (250 and 400 mg/kg) for 8 weeks effectively alleviated the pathological indicators of colitis such as bodyweight reduction, disease activity index score, shortening of colon length and abnormal colon histology. The plasma levels of lipopolysaccharide (LPS) and inflammatory factors such as interleukin-6 (IL-6), IL-1β and tumor necrosis factor (TNF)-α were all significantly reduced. Supplementation of SH (10 mg/L) also inhibited LPS-elicited IL-1β production by RAW264.7 macrophages. Real-time PCR and western blot showed that treatment with SH significantly inhibited the phosphorylation of nuclear factor kappa B inhibitor alpha (IκBα) and decreased the expression of IL-6/IL-1β-maturation genes such as apoptosis-associated speck-like protein (ASC3) and caspase-1 in the colon of DSS-induced colitis mice. These results suggest that SH is adequate for the treatment of colitis. Inhibiting the expression and release of inflammatory factors may participate in the colitis-ameliorating effect of SH.

Enhanced immune responses and effectiveness of refined outer membrane protein vaccines against Vibrio harveyi in orange-spotted grouper (Epinephelus coioides)

Vibriosis is a severe infection occurring in many commercially important marine fish species. In this study, vaccines containing Vibrio harveyi recombinant outer membrane protein K (rOmpK), outer membrane protein U (rOmpU) and rOmpK-OmpU fusion protein in addition to the metabolizable Montanide^TM ISA 763 A VG adjuvant were developed and evaluated in the orange-spotted grouper. The results indicate that recombinant V. harveyi protein-based vaccines resulted in a remarkably higher expression of IL-1β and IL-8 at 24 hr, and greater antibody production, as early as 2 weeks postimmunization. Notably, enhanced immune responses and significant protective efficacy against V. harveyi infections were observed in the fusion protein vaccine-injected fishes with relative per cent survival value of 81.8%. Additionally, the rOmpK-OmpU antisera presented a high bactericidal effect on not only V. harveyi, but also Vibrio parahaermolyticus and Vibrio alginolyticus. Our results demonstrated that the fusion protein rOmpK-OmpU was an effective vaccine candidate that exhibited potentially great versatility for controlling vibrio infections.

Catechin Weakens Diabetic Retinopathy by Inhibiting the Expression of NF-κB Signaling Pathway-Mediated Inflammatory Factors

OBJECTIVE

The aim of the present study was to explore the role of catechin on the expression of heat shock protein 27 (HSP27), nuclear factor-kappa beta (NF-κB) and inflammatory factors IL-1β, IL-6 and TNF-α in streptozotocin (STZ)-induced diabetic retinopathy (DR) rats.

METHODS

A total of 150 rats were selected and randomly assigned to five groups: control group, STZ group, and three groups with different concentrations of catechin (low, middle and high concentrations). After STZ induction, DR rats were treated with different concentrations of catechin (50 mg/kg/day, low catechin group; 100 mg/kg/ day, middle catechin group; 200 mg/kg/day, high catechin group) by intravitreal injection for eight weeks. Hematoxylin and eosin (H&E) staining was used to observe the pathological changes in retinal tissues. The mRNA and protein levels of HSP27 in the retina were determined by RT-PCR and western blotting. Furthermore, the expression of NF-κB p65 and p-NF-κB p65 were determined by western blotting, while the expression of IL-1β, IL-6, and TNF-α were determined by ELISA.

RESULTS

HSP27 levels increased in STZ-induced DR rats, and became further upregulated after catechin treatment. Furthermore, IL-1β, IL-6, and TNF-α levels were upregulated in the retinas of STZ-induced DR rats, but these changes were partially inhibited after treatment with catechin. Moreover, the application of catechin inhibited the activation of NF-κB, which was upregulated in STZ-induced DR. A negative correlation was observed between the concentrations of catechin and the expression of inflammatory factors.

CONCLUSION

Catechin can weaken DR induced by STZ by increasing HSP27 levels and decreasing the production of associated inflammatory factors. This could help to treat DR in clinic.

Impact of the Reticular Stress and Unfolded Protein Response on the inflammatory response in endometrial stromal cells

During decidualization, endometrial stromal cells undergo reticular stress (RS) and unfolded protein response (UPR), allowing the endoplasmic reticulum-expansion and immunomodulators production. Physiological RS generates the activation of sensing proteins, inflammasome activation and mature-IL-1β secretion, associated with pro-implantatory effects. We focus on the impact of RS and UPR on decidualized cells and whether they induce a physiological sterile inflammatory response through IL-1β production. Human endometrial stromal cell line (HESC) after decidualization treatment with MPA + dibutyryl-cAMP (Dec) increased the expression of RS-sensors (ATF6, PERK and IRE1α) and UPR markers (sXBP1 and CHOP) in comparison with Non-dec cells. Then we found increased NLRP3 expression in Dec cells compared with Non-dec cells. In fact STF-083010 (an IRE1α inhibitor) prevented this increase. Downstream, increased levels of active caspase-1 on Dec cells were detected by FAM-Flica Caspase-1 associated with an increase in IL-1β production. Moreover, the treatment with STF-083010 decreased the invasion index observed in Dec cells, evaluated by an in vitro model of implantation. In endometrial biopsies from recurrent spontaneous abortion patients an increased expression of IRE1α was found in comparison with fertile women; while recurrent implantation failure samples showed a lower expression of sXBP1, TXNIP and NLRP3 than fertile women, suggesting that RS/UPR tenors might condition endometrial receptivity.

Human papillomavirus type 16 antagonizes IRF6 regulation of IL-1β

Human papillomavirus type 16 (HPV16) and other oncoviruses have been shown to block innate immune responses and to persist in the host. However, to avoid viral persistence, the immune response attempts to clear the infection. IL-1β is a powerful cytokine produced when viral motifs are sensed by innate receptors that are members of the inflammasome family. Whether oncoviruses such as HPV16 can activate the inflammasome pathway remains unknown. Here, we show that infection of human keratinocytes with HPV16 induced the secretion of IL-1β. Yet, upon expression of the viral early genes, IL-1β transcription was blocked. We went on to show that expression of the viral oncoprotein E6 in human keratinocytes inhibited IRF6 transcription which we revealed regulated IL-1β promoter activity. Preventing E6 expression using siRNA, or using E6 mutants that prevented degradation of p53, showed that p53 regulated IRF6 transcription. HPV16 abrogation of p53 binding to the IRF6 promoter was shown by ChIP in tissues from patients with cervical cancer. Thus E6 inhibition of IRF6 is an escape strategy used by HPV16 to block the production IL-1β. Our findings reveal a struggle between oncoviral persistence and host immunity; which is centered on IL-1β regulation.

Synthesis of interleukin 1 beta and interleukin 6 in human lymphocytes is stimulated by tributyltin

Tributyltin (TBT) is a widespread environmental contaminant that is present in human blood and other tissues. It has been shown to disrupt the immune function of human natural killer (NK) cells and to alter the secretion of a number of pro-inflammatory cytokines from immune cells. Secretion of both interleukin 1β (IL-1β) and interleukin 6 (IL-6) from human lymphocytes can be increased dependent upon the level of TBT exposure. This study shows that the TBT-induced increases in secretion of both cytokines are due to TBT-induced increases in the synthesis of these proteins and not simply because of the release of pre-existing cytokine. Furthermore, the data indicate that these TBT-induced increases in IL-1β and IL-6 synthesis require MAP kinase signaling pathways. Additionally, elevated synthesis of IL-1β and IL-6 seen at the highest exposures to TBT (200, 200, 50 nM) were accompanied by increases in the mRNA for these cytokines. TBT-induced increases in IL-1β and IL-6 mRNAs were also shown to be dependent on MAP kinase signaling. The study suggests that TBT has the capacity to increase immune cell production of these 2 important pro-inflammatory cytokines and that this increase is in part explained by increased mRNA for the cytokines.

Physicochemical Characterization, Antioxidant and Immunostimulatory Activities of Sulfated Polysaccharides Extracted from Ascophyllum nodosum

Polysaccharides from Ascophyllum nodosum (AnPS) were extracted and purified via an optimized protocol. The optimal extraction conditions were as follows: extraction time of 4.3 h, extraction temperature of 84 °C and ratio (v/w, mL/g) of extraction solvent (water) to raw material of 27. The resulting yield was 9.15 ± 0.23% of crude AnPS. Two fractions, named AnP1-1 and AnP2-1 with molecular weights of 165.92 KDa and 370.68 KDa, were separated from the crude AnPS by chromatography in DEAE Sepharose Fast Flow and Sephacryl S-300, respectively. AnP1-1 was composed of mannose, ribose, glucuronic acid, glucose and fucose, and AnP2-1 was composed of mannose, glucuronic acid, galactose and fucose. AnPS, AnP1-1 and AnP2-1 exhibited high scavenging activities against ABTS radical and superoxide radical, and showed protective effect on H₂O₂-induced oxidative injury in RAW264.7 cells. Furthermore, the immunostimulatory activities of AnP1-1 and AnP2-1 were evaluated by Caco-2 cells, the results showed both AnP1-1 and AnP2-1 could significantly promote the production of immune reactive molecules such as interleukin (IL)-8, IL-1β, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Therefore, the results suggest that AnPS and its two fractions may be explored as a potential functional food supplement.

Hemin Induces the Activation of NLRP3 Inflammasome in N9 Microglial Cells

BACKGROUND

Hemin is an important sterile component that induces a neuroinflammatory response after intracerebral hemorrhage, in which NLRP3 inflammasome activation has also proved to be involved. Although microglial activation acts as a key contributor in the neuroinflammatory response, the relationship between hemin and NLRP3 in microglia remains poorly understood.

OBJECTIVE

To investigate whether or not hemin regulates microglia-mediated secondary injury through activating the NLRP3/caspase-1 signaling pathway in microglia.

METHODS

In this study, N9 microglial cells were treated with hemin, and subsequently used to detect the production of caspase-1 p10 and NLRP3 inflammasome assembly. An ELISA was subsequently performed to measure the secretion of IL-1β.

RESULTS

It was found that the production of activated caspase-1 was dose- and time-dependent with regards to hemin. Moreover, hemin was observed to be capable of inducing the assembly of the NLRP3 inflammasome without any increase in IL-1β. Similarly, the supernatant of hemin-treated primary microglial cells did not increase in IL-1β secretion. Furthermore, hemin-induced NLRP3 inflammasome activation did not significantly affect pyroptosis.

CONCLUSION

Hemin is a potential sterile danger signal molecule that can induce inflammasome activation without directly mediating inflammation damage on microglia.