Investigating the Immune-Stimulating Potential of ß-Glucan from Aureobasidium pullulans in Cancer Immunotherapy.

ß-glucan, a polysaccharide found in various sources, exhibits unique physicochemical properties, yet its high polymerization limits clinical applications because of its solubility. Addressing this limitation, we introduce PPTEE-glycan, a highly purified soluble ß-1,3/1,6-glucan derived from Aureobasidium pullulans. The refined PPTEE-glycan demonstrated robust immune stimulation in vitro, activated dendritic cells, and enhanced co-stimulatory markers, cytokines, and cross-presentation. Formulated as a PPTEE + microemulsion (ME), it elevated immune responses in vivo, promoting antigen-specific antibodies and CD8+ T cell proliferation. Intratumoral administration of PPTEE + ME in tumor-bearing mice induced notable tumor regression, which was linked to the activation of immunosuppressive cells. This study highlights the potential of high-purity Aureobasidium pullulans-derived ß-glucan, particularly PPTEE, as promising immune adjuvants, offering novel avenues for advancing cancer immunotherapy.

Water Extract of Desalted Salicornia europaea Inhibits RANKL-Induced Osteoclast Differentiation and Prevents Bone Loss in Ovariectomized Mice.

Osteoporosis, which is often associated with increased osteoclast activity due to menopause or aging, was the main focus of this study. We investigated the inhibitory effects of water extract of desalted Salicornia europaea L. (WSE) on osteoclast differentiation and bone loss in ovariectomized mice. Our findings revealed that WSE effectively inhibited RANKL-induced osteoclast differentiation, as demonstrated by TRAP staining, and also suppressed bone resorption and F-actin ring formation in a dose-dependent manner. The expression levels of genes related to osteoclast differentiation, including NFATc1, ACP5, Ctsk, and DCSTAMP, were downregulated by WSE. Oral administration of WSE improved bone density and structural parameters in ovariectomized mice. Dicaffeoylquinic acids (DCQAs) and saponins were detected in WSE, with 3,4-DCQA, 3,5-DCQA, and 4,5-DCQA being isolated and identified. All tested DCQAs, including the aforementioned types, inhibited osteoclast differentiation, bone resorption, and the expression of osteoclast-related genes. Furthermore, WSE and DCQAs reduced ROS production mediated by RANKL. These results indicate the potential of WSE and its components, DCQAs, as preventive or therapeutic agents against osteoporosis and related conditions.

Oral Administration of Lactobacillus sakei CVL-001 Improves Recovery from Dextran Sulfate Sodium-Induced Colitis in Mice by Microbiota Modulation.

Inflammatory bowel disease (IBD) is an intestinal chronic inflammatory disease, and its incidence is steadily increasing. IBD is closely related to the intestinal microbiota, and probiotics are known to be a potential therapeutic agent for IBD. In our study, we evaluated the protective effect of Lactobacillus sakei CVL-001, isolated from Baechu kimchi, on dextran sulfated sodium (DSS)-induced colitis in mice. The oral administration of L. sakei CVL-001 according to the experimental schedule alleviated weight loss and disease activity in the mice with colitis. Furthermore, the length and histopathology of the colon improved. The expression of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß genes decreased in the colons of mice that were administered L. sakei CVL-001, whereas that of IL-10 increased. The expressions of genes coding for E-cadherin, claudin3, occludin, and mucin were also restored. In co-housed conditions, L. sakei CVL-001 administration did not improve disease activity, colon length, and histopathology. Microbiota analysis revealed that L. sakei CVL-001 administration increased the abundance of microbiota and altered Firmicutes/Bacteroidetes ratio, and decreased Proteobacteria. In conclusion, L. sakei CVL-001 administration protects mice from DSS-induced colitis by regulating immune response and intestinal integrity via gut microbiota modulation.

Ethanol extract of Chrysanthemum zawadskii inhibits the NLRP3 inflammasome by suppressing ASC oligomerization in macrophages.

Chrysanthemum zawadskii (C. zawadskii) is used in traditional East Asian medicine for the treatment of various diseases, including inflammatory disease. However, it has remained unclear whether extracts of C. zawadskii inhibit inflammasome activation in macrophages. The present study assessed the inhibitory effect of an ethanol extract of C. zawadskii (CZE) on the activation of the inflammasome in macrophages and the underlying mechanism. Bone marrow-derived macrophages were obtained from wild-type C57BL/6 mice. The release of IL-1ß and lactate dehydrogenase in response to nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome activators, such as ATP, nigericin and monosodium urate (MSU) crystals, was significantly decreased by CZE in lipopolysaccharide (LPS)-primed BMDMs. Western blotting revealed that CZE inhibited ATP-induced caspase-1 cleavage and IL-1ß maturation. To investigate whether CZE inhibits the priming step of the NLRP3 inflammasome, we confirmed the role of CZE at the gene level using RT-qPCR. CZE also downregulated the gene expression of NLRP3 and pro-IL-1ß as well as NF-κB activation in BMDMs in response to LPS. Apoptosis-associated speck-like protein containing a caspase-recruitment domain (CARD) oligomerization and speck formation by NLRP3 inflammasome activators were suppressed by CZE. By contrast, CZE did not affect NLR family CARD domain-containing protein 4 or absent in melanoma 2 inflammasome activation in response to Salmonella typhimurium and poly(dA:dT) in LPS-primed BMDMs, respectively. The results revealed that three key components of CZE, namely linarin, 3,5-dicaffeoylquinic acid and chlorogenic acid, decreased IL-1ß secretion in response to ATP, nigericin and MSU. These findings suggest that CZE effectively inhibited activation of the NLRP3 inflammasome.

WFDC2 Promotes Spasmolytic Polypeptide-Expressing Metaplasia Through the Up-Regulation of IL33 in Response to Injury.

BACKGROUND & AIMS: WAP 4-disulfide core domain protein 2 (WFDC2), also known as human epididymis protein 4, is a small secretory protein that is highly expressed in fibrosis and human cancers, particularly in the ovaries, lungs, and stomach. However, the role of WFDC2 in carcinogenesis is not fully understood. The present study aimed to investigate the role of WFDC2 in gastric carcinogenesis with the use of preneoplastic metaplasia models. METHODS: Three spasmolytic polypeptide-expressing metaplasia (SPEM) models were established in both wild-type and Wfdc2-knockout mice with DMP-777, L635, and high-dose tamoxifen, respectively. To reveal the functional role of WFDC2, we performed transcriptomic analysis with DMP-777-treated gastric corpus specimens. RESULTS: Wfdc2-knockout mice exhibited remarkable resistance against oxyntic atrophy, SPEM emergence, and accumulation of M2-type macrophages in all 3 SPEM models. Transcriptomic analysis revealed that Wfdc2-knockout prevented the up-regulation of interleukin-33 (IL33) expression in the injured mucosal region of SPEM models. Notably, supplementation of recombinant WFDC2 induced IL33 production and M2 macrophage polarization, and ultimately promoted SPEM development. Moreover, long-term treatment with recombinant WFDC2 was able to induce SPEM development. CONCLUSIONS: WFDC2 expressed in response to gastric injury promotes SPEM through the up-regulation of IL33 expression. These findings provide novel insights into the role of WFDC2 in gastric carcinogenesis.

Melatonin Inhibits Osteoclastogenesis and Bone Loss in Ovariectomized Mice by Regulating PRMT1-Mediated Signaling.

Melatonin, a pineal gland hormone, has been suggested to treat postmenopausal osteoporosis due to its inhibitory effect on osteoclast differentiation. We previously reported that protein arginine methyltransferase 1 (PRMT1) was an important mediator of receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. However, the relationship between melatonin and PRMT1 in osteoclast differentiation and estrogen deficiency-induced osteoporosis is unclear. In this study, we investigated the inhibitory mechanisms of melatonin in vitro and in vivo by focusing on PRMT1. Melatonin treatment effectively blocked RANKL-induced osteoclastogenesis by inhibiting PRMT1 and asymmetric dimethylarginine (ADMA) expression. RANKL-induced tumor necrosis factor receptor-associated factor 6 (TRAF6) and the phosphorylation of JNK were also suppressed by melatonin, and TRAF6 siRNA attenuated RANKL-induced p-JNK and PRMT1 production. Melatonin inhibited the transcriptional activity of NF-κB by interfering with the binding of PRMT1 and NF-κB subunit p65 in RANKL-treated bone marrow-derived macrophages. Our results also revealed that melatonin inhibits RANKL-induced PRMT1 expression through receptors-independent pathway. Thus, the anti-osteoclastogenic effect of melatonin was mediated by a cascade of inhibition of RANKL-induced TRAF6, JNK, PRMT1, and NF-κB signaling in melatonin receptors-independent pathway. In vivo, ovariectomy caused significant decreases in bone mineral density, but melatonin treatment alleviated the ovariectomized (OVX)-induced bone loss by inhibiting bone resorption. Furthermore, the expression PRMT1 and TRAP mRNA was upregulated in OVX-femurs, but effectively suppressed by melatonin injection. These findings suggest that melatonin inhibited osteoclast differentiation and estrogen deficiency-induced osteoporosis by suppressing RANKL-induced TRAF6, JNK, PRMT1, and NF-κB signaling cascades in melatonin receptors-independent pathway.

Receptor-interacting protein kinase 2 contributes to host innate immune responses against Fusobacterium nucleatum in macrophages and decidual stromal cells.

PROBLEM: Chorioamnionitis is caused by a bacterial infection that ascends from the vagina and can cause adverse pregnancy outcomes (APOs). Fusobacterium nucleatum (F. nucleatum) is a periodontal pathogen associated with the occurrence of APOs. In this study, we evaluated whether receptor-interacting protein kinase 2 (Ripk2), an adaptor protein of the cytosolic receptors nucleotide-binding oligomerization domain (NOD)1 and NOD2, in macrophages and human decidual stromal cells (hDSCs) contributes to immune responses against F. nucleatum. METHOD OF STUDY: Bone marrow-derived macrophages (BMDMs) isolated from wild-type (WT) and Ripk2-deficient mice and hDSCs were cultured with F. nucleatum (MOI 1, 10, 100). BMDMs and hDSCs were assessed using enzyme-linked immunosorbent assay, Western blot analysis, real-time PCR, and nitrite assay. RESULTS: Fusobacterium nucleatum-induced production of IL-6, but not of TNF-α and IL-10, was lower in Ripk2-deficient BMDMs than in WT cells. Western blotting revealed a decrease in F. nucleatum-induced p65 phosphorylation in Ripk2-deficient macrophages, whereas mitogen-activated protein kinases activation was comparable between WT and Ripk2-deficient cells. The production of nitric oxide (NO) in response to F. nucleatum and the gene and protein expression of inducible NO synthase was impaired in Ripk2-deficient BMDMs. In hDSCs, F. nucleatum upregulated the gene and protein expression of NOD1, NOD2, and Ripk2 in a time-dependent manner. F. nucleatum also increased the production of IL-6, CXCL8, and CCL2, whereas this production was decreased by the Ripk2 inhibitors SB203580 and PP2. CONCLUSIONS: In conclusion, Ripk2 signaling appears to contribute to the F. nucleatum-induced immune response and can be a preventive and therapeutic target against APOs.

Protein arginine methyltransferase 1 contributes to the development of allergic rhinitis by promoting the production of epithelial-derived cytokines.

BACKGROUND: Arginine methylation is a posttranslational modification mediated by protein arginine methyltransferases (PRMTs). Although previous studies have shown that PRMT1 contributes to the severity of allergic airway inflammation or asthma, the underlying mechanism is poorly understood. OBJECTIVE: This study aimed to explore the role of PRMT1 and its relevant mechanism in the development of allergic rhinitis (AR). METHODS: The expression levels of PRMTs and cytokines were determined by RT-PCR, and the localization of PRMT1 was determined by immunohistochemistry and confocal microscopy. The levels of house dust mite (HDM)-specific immunoglobulins in serum and of cytokines in nasal lavage fluids were determined by ELISA. PRMT1 inhibition was achieved by siRNA and treatment with the pan PRMT inhibitor arginine N-methyltransferase inhibitor-1. RESULTS: PRMT1 expression was significantly increased in the nasal mucosa of patients and mice with AR. The degree of eosinophilic infiltration in the nasal mucosa was reduced in PRMT1+/- AR mice compared with wild-type mice. PRMT1 haploinsufficiency reduced the levels of HDM-specific immunoglobulins in serum and those of TH2 (IL-4, IL-5, and IL-13) and epithelial (thymic stromal lymphopoietin [TSLP], IL-25, and IL-33) cytokines in the nasal lavage fluids of AR mice. In nasal epithelial cells, HDM and IL-4 cooperate to enhance PRMT1 expression through a mitogen-activated protein kinase-dependent pathway. In addition, PRMT1 was essential for the production of TSLP, IL-25, and IL-33 in response to HDM and IL-4. Arginine N-methyltransferase inhibitor-1 treatment alleviated AR in the mouse model. CONCLUSIONS: PRMT1 plays an important role in AR development by regulating epithelial-derived cytokine production and might be a new therapeutic target for AR.

Unveiling the Crucial Role of Type IV Secretion System and Motility of Helicobacter pylori in IL-1ß Production via NLRP3 Inflammasome Activation in Neutrophils.

Helicobacter pylori is a gram-negative, microaerophilic, and spiral-shaped bacterium and causes gastrointestinal diseases in human. IL-1ß is a representative cytokine produced in innate immune cells and is considered to be a key factor in the development of gastrointestinal malignancies. However, the mechanism of IL-1ß production by neutrophils during H. pylori infection is still unknown. We designed this study to identify host and bacterial factors involved in regulation of H. pylori-induced IL-1ß production in neutrophils. We found that H. pylori-induced IL-1ß production is abolished in NLRP3-, ASC-, and caspase-1/11-deficient neutrophils, suggesting essential role for NLRP3 inflammasome in IL-1ß response against H. pylori. Host TLR2, but not TLR4 and Nod2, was also required for transcription of NLRP3 and IL-1ß as well as secretion of IL-1ß. H. pylori lacking cagL, a key component of the type IV secretion system (T4SS), induced less IL-1ß production in neutrophils than did its isogenic WT strain, whereas vacA and ureA were dispensable. Moreover, T4SS was involved in caspase-1 activation and IL-1ß maturation in H. pylori-infected neutrophils. We also found that FlaA is essential for H. pylori-mediated IL-1ß production in neutrophils, but not dendritic cells. TLR5 and NLRC4 were not required for H. pylori-induced IL-1ß production in neutrophils. Instead, bacterial motility is essential for the production of IL-1ß in response to H. pylori. In conclusion, our study shows that host TLR2 and NLRP3 inflammasome and bacterial T4SS and motility are essential factors for IL-1ß production by neutrophils in response to H. pylori.

Water extract of tendril of Cucurbita Moschata Duch. suppresses RANKL-induced osteoclastogenesis by down-regulating p38 and ERK signaling.

Background: Pumpkin (Curcubita sp.) is a natural product that is commonly used in folk medicine. However, the inhibitory effect and molecular mechanisms of tendril of Cucurbita Moschata Duch. (TCMD) on osteoclast differentiation have yet to be clearly elucidated. Thus, the present study aimed to investigate the effect and underlying mechanism of water extract of TCMD on osteoclast differentiation. Methods: Bone marrow-derived macrophages (BMDMs), osteoclast precursors, were cultured with macrophage colony stimulating factor (M-CSF) 30 ng/ml and receptor activator of nuclear factor-kappa B ligand (RANKL) 100 ng/ml for four days. We investigated the effect of TCMD on RANKL-induced osteoclast differentiation, tartrate-resistant acid phosphatase (TRAP) staining, F-actin ring formation, and bone resorption assay. RANKL signaling pathways were determined through Western blotting, and osteoclast differentiation marker genes were confirmed by Real-time PCR. Results: TCMD inhibited the RANKL-induced osteoclast differentiation in a dose-dependent manner without cytotoxicity. Further, F-actin ring formation and bone resorption were reduced by TCMD in RANKL-treated BMDMs. In addition, TCMD decreased the phosphorylation of p38 and ERK as well as the expression of osteoclast-related genes in BMDMs treated with RANKL. Conclusion: These findings suggest that TCMD may have preventive and therapeutic effects for destructive bone diseases.

PRMT1 mediates RANKL-induced osteoclastogenesis and contributes to bone loss in ovariectomized mice.

Protein arginine methylation is a novel form of posttranslational modification mediated by protein arginine methyltransferase (PRMTs). PRMT1, a major isoform of the PRMT family, is responsible for various biological functions, including cellular differentiation. Although the important function that PRMT1 plays in various tissues is being increasingly recognized, its role in receptor activation of NF-κB ligand (RANKL)-induced osteoclastogenesis or osteoporosis has not yet been described. Here, we show that PRMT1 is essential for RANKL-induced osteoclastogenesis in vitro and for bone loss in vivo. RANKL treatment increased the expression of PRMT1 and its nuclear localization in bone marrow-derived macrophages (BMDMs) in a c-Jun N-terminal kinase (JNK)-dependent manner. Silencing PRMT1 attenuated RANKL-induced osteoclastogenesis by decreasing tartrate-resistant acid phosphatase (TRAP)-positive cells and inhibiting F-actin ring formation and bone resorption, which was confirmed in a separate experiment using haploinsufficient cells from PRMT1+/- mice. Our results also revealed that PRMT1 regulates the transcription activity of NF-κB by directly interacting with it in RANKL-treated BMDMs. An in vivo study showed that the haploinsufficiency of PRMT1 reduced the enzyme activity of TRAP and increased the bone mineral density in the metaphysis of ovariectomized (OVX) mice. Finally, treatment with estrogen (E2) downregulated the RANKL-induced expression of PRMT1, suggesting that estrogen may exert an inhibitory effect on osteoclastogenesis by suppressing PRMT1 expression. Our results suggest that PRMT1 plays an important role in the progression of osteoporosis and that it might be a good therapeutic target for postmenopausal osteoporosis.

Mycobacterium tuberculosis ESAT6 induces IFN-ß gene expression in Macrophages via TLRs-mediated signaling.

Mycobacterium tuberculosis is a highly virulent bacterium that causes tuberculosis. It infects about one third of the world's population. Type I interferons (IFNs) play a detrimental role in host defense against M. tuberculosis infection. Proteins secreted by M. tuberculosis through ESX-1 secretion system contribute to type I IFNs production. However, the precise mechanism by which 6-kDa early secretory antigen target (ESAT6), one of ESX-1-mediated secretory proteins, induces type I IFNs production in host cells is currently unclear. Therefore, the objective of the present study was to determine the underlying molecular mechanism regulating ESAT6-mediated gene expression of IFN-ß in macrophages. Recombinant ESAT6 produced from E. coli expression system induced IFN-ß gene expression in various types of macrophages such as mouse bone marrow-derived macrophages (BMDMs), peritoneal macrophages, and MH-S cells (murine alveolar macrophage cell line). Deficiency of TLR4 and TRIF absolutely abrogated ESAT6-induced IFN-ß gene expression. TLR2 and MyD88 were partially involved in IFN-ß gene expression in response to low dose of ESAT6. Another recombinant ESAT6 produced from baculovirus system also upregulated IFN-ß gene expression via TLR4-dependent pathway. Polymyxin B (PMB) treatment impaired LPS-induced IFN-ß expression. However, IFN-ß expression induced by ESAT6 was not influenced by PMB. This suggests that ESAT6-mediated IFN-ß expression is not due to LPS contamination. Treatment with ESAT6 resulted in activation of TBK1 and IRF3 in macrophages. Such activation was abolished in TLR4- and TRIF-deficient cells. Moreover, inhibition of IRF3 and TBK1 suppressed IFN-ß gene expression in response to ESAT6. Our results suggest that ESAT6 might contribute to virulence of M. tuberculosis by regulating type I IFNs production through TLR4-TRIF signaling pathway.

Inhibitory effect of 1­tetradecanol on Helicobacter pylori­induced production of interleukin­8 and vascular endothelial growth factor in gastric epithelial cells.

Helicobacter pylori (H. pylori) infection activates pro­inflammatory mediators, including interleukin (IL)­8 and vascular endothelial growth factor (VEGF) in gastric epithelial cells. 1­Tetradecanol (1­TD) has been purified from Dendropanax morbifera Leveille; its physiological activities are poorly understood. The present study assessed whether 1­TD has an effect on H. pylori­mediated inflammation in AGS gastric epithelial cells. 1­TD reduced IL­8 production by AGS cells in response to H. pylori in a significant and dose­dependent manner, as measured by ELISA. Western blot analysis demonstrated that 1­TD also suppressed the activation of nuclear factor­κB, and two mitogen activated protein kinase species (p38 and extracellular signal­regulated kinase 1/2), but not c­Jun N­terminal kinase in H. pylori­infected AGS cells. As predicted, VEGF expression and hypoxia inducible factor­1α stabilization induced by H. pylori in AGS cells were inhibited by 1­TD. In addition, 1­TD directly inhibited the growth of H. pylori in a dose­dependent manner, as investigated by measuring the optical density. These findings indicated that 1­TD may be a potential preventive or therapeutic agent for H. pylori­induced gastric inflammation.