Mechanism of inhibition of melanoma by fucoxanthin simulated in vitro digestion products in cell models constructed using human malignant melanoma cells (A375) and keratinocytes (HaCaT).

Recently, the increasing incidence of malignant melanoma has become a major public health concern owing to its poor prognosis and impact on quality of life. Consuming foods with potent antitumor compounds can help prevent melanoma and maintain skin health. Fucoxanthin (FX), a naturally occurring carotenoid found in brown algae, possesses antitumor properties. However, its bioavailability, safety risks, and in vivo effects and mechanisms against melanoma remain unclear. This research focused on evaluating the safety and prospective antimelanoma impact of simulated gastrointestinal digestion products (FX-ID) on HaCaT and A375 cells.The results indicate that FX-ID exerts negative effects on mitochondria in A375 cells, increases Bax expression, releases Cytochrome C, and activates cleaved caspase-3, ultimately promoting apoptosis. Additionally, FX-ID influences the mitogen-activated protein kinase (MAPK) pathway by enhancing cyclooxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB) levels, consequently facilitating apoptosis and inflammation without significantly impacting HaCaT cells. These findings provide insight into inhibitory mechanism of FX-ID against melanoma, guiding the development of functional foods for prevention.

Engeletin attenuates the inflammatory response via inhibiting TLR4-NFκB signaling pathway in Crohn's disease-like colitis.

ETHNOPHARMACOLOGICAL RELEVANCE: Smilax glabra rhizome has a long history been used for clinical purposes in traditional Chinese medicinal for treating various inflammatory conditions. Engeletin1 (ENG) is one of the most abundant bioactive compounds found in Smilax glabra rhizome, with anti-inflammatory, antioxidant, and ulcer-preventing activities. AIM OF THE STUDY: The purpose of this study was to investigate the ability of ENG to alleviate inflammatory symptoms and improve epithelial barrier integrity utilize a 2,4,6-trinitrobenzene sulfonic acid2 (TNBS)-induced murine model in Crohn's disease3 (CD)-like colitis, and to characterize the underlying anti-inflammatory mechanisms of action. MATERIALS AND METHODS: A colitis model was established in BALB/c mice and treated with ENG for 7 days. RAW264.7 macrophages were pre-treated with ENG and lipopolysaccharide4 (LPS) stimulation. The mice's weight and colon length were assessed. qPCR and Western blotting were used to analyze gene expression and TLR4-NFκB pathway. Flow cytometry was used to analyze the polarization states of the macrophages. RESULTS: Treatment with ENG was sufficient to significantly alleviate symptoms of inflammation and colonic epithelial barrier integrity in treated mice. Significant inhibition of TNF-α, IL-1ß, and IL-6 expression was observed following ENG treatment in vivo and in vitro. ENG was also determined to be capable of inhibiting the expression of iNOS and CD86, inhibited M1 macrophage polarization in vitro, as well as the TLR4-NFκB signaling pathway. Molecular docking showed a highly stable binding between ENG and TLR4. CONCLUSION: ENG has been proven to alleviate inflammation and ameliorate the damage of epithelial barrier in CD-like colitis. ENG also suppressed the M1 macrophages polarization and the inhibited inflammatory cytokines. TLR4-NFκB signaling pathway, especially TLR4, may be the target of ENG. These data offer a new insight into the therapeutic mechanisms of ENG.

Protein Kinase R (PKR) as a Novel dsRNA Sensor in Antiviral Innate Immunity.

Protein kinase R (PKR), a key double-stranded RNA (dsRNA)-activated sensor, is pivotal for cellular responses to diverse stimuli. This protocol delineates a comprehensive methodological framework employing single luciferase assays, yeast assays, immunoblot assays, and quantitative PCR (qPCR) to discern and validate PKR activities and their downstream impacts on NF-κB-activating signaling pathways. These methodologies furnish a systematic approach to unraveling the role of PKR as a dsRNA sensor and effector in antiviral innate immunity, enabling in-depth analyses of dsRNA sensor activities.

Identifying a Gene Deficiency in the Antiviral Innate Immune Signaling Pathway.

Innate immunity is an important defense barrier for the human body. After viral pathogen-associated molecular patterns (PAMPs) are detected by host-pathogen recognition receptors (PRRs), the associated signaling pathways trigger the activation of the interferon (IFN) regulatory factor (IRF) family members and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). However, any gene defects among the signaling adaptors will compromise innate immune efficiency. Therefore, investigating genetic defects in the antiviral innate immune signaling pathway is important. We summarize the commonly used research methods related to antiviral immune gene defects and outline the relevant research protocols, which will help investigators study antiviral innate immunity.

Syzygium cumini (L.) skeels mitigate diabetic nephropathy by regulating Nrf2 pathway and mitocyhondrial dysfunction: In vitro and in vivo studies.

ETHNOPHARMACOLOGICAL PREVALENCE: Hyperglycemia in diabetes increases the generation of advanced glycation end products (AGEs) through non-enzymatic reactions. The interaction between AGEs and their receptors (RAGE) leads to oxidative and inflammatory stress, which plays a pivotal role in developing diabetic nephropathy. Syzygium cumini (SC) L. (DC.) homeopathic preparations viz. 200C, 30C, and mother tincture [MT] are used to treat diabetes. This study aimed to elucidate the regulatory effects of SC preparations (200C, 30C, and MT) on the nuclear factor erythroid 2-related factor 2 (Nrf2) - nuclear factor-κB (NF-κB) pathways and mitochondrial dysfunction in mitigating diabetic nephropathy (DN). MATERIALS AND METHODS: Streptozotocin-induced diabetic rats were treated with SC preparations (200C, 30C, MT; 1:20 dilution in distilled water; 600 µL/kg body weight) and metformin (45 mg/kg body weight) twice daily for 40 days. DN was evaluated through biochemical parameters and histological examination. Renal tissue lysates were analyzed for glycation markers. Protein and gene levels of Nrf2, NF-κB, and mitochondrial dysfunctional signaling were determined via western blotting and RT-qPCR. An immunohistochemical analysis of the kidneys was performed. In vitro, human serum albumin (HSA - 10 mg/ml) was glycated with methylglyoxal (MGO - 55 mM) in the presence of SC preparations (200C, 30C, MT) for eight days. Glycated samples (400 µg/mL) were incubated with renal cells (HEK-293) for 24 h. Further reactive oxygen species production, Nrf2 nuclear translocation, and protein or gene expression of Nrf2 and apoptosis markers were analyzed by western blotting, RT-qPCR, and flow cytometry. Molecular docking of gallic and ellagic acid with the HSA-MGO complex was performed. RESULT: In vivo experiments using streptozotocin-induced diabetic rats treated with SC preparations exhibited improved biochemical parameters, preserved kidney function, and reduced glycation adduct formation in a dose-dependent manner. Furthermore, SC preparations downregulated inflammatory mediators such as RAGE, NF-κB, vascular endothelial growth factor (VEGF), and Tumor necrosis factor α (TNF-α) while upregulating the Nrf2-dependent antioxidant and detoxification pathways. They downregulated B-cell lymphoma 2 (Bcl-2) associated X-protein (BAX), C/EBP homologous protein (CHOP), Dynamin-related protein 1 (DRP1), and upregulated BCL 2 gene expression. Notably, SC preparations facilitated nuclear translocation of Nrf2, leading to the upregulation of antioxidant enzymes and the downregulation of oxidative stress markers. Molecular docking studies revealed favorable interactions between gallic (-5.26 kcal/mol) and ellagic acid (-4.71 kcal/mol) with the HSA-MGO complex. CONCLUSION: SC preparations mitigate renal cell apoptosis and mitochondrial dysfunction through Nrf2-dependent mechanisms.

Melatonin inhibits bovine viral diarrhea virus replication by ER stress-mediated NF-κB signal pathway and autophagy in MDBK cells.

Bovine viral diarrhea-mucosal disease (BVD-MD) is a contagious disease in cattle, caused by the bovine viral diarrhea virus (BVDV). This virus continues to spread globally, exerting pressure on both public health and the economy. Despite its impact, there are currently no effective drugs for treating BVDV. This study utilized Madin-Darby bovine kidney (MDBK) cells as a model to investigate the antiviral effects of melatonin against Bovine Viral Diarrhea Virus (BVDV) and its connection with endoplasmic reticulum (ER) stress. Our results show that melatonin can suppress BVDV proliferation in MDBK cells by modulating the endoplasmic reticulum (ER) stress-mediated NF-κB pathway and autophagy. Specifically, melatonin alleviated ER stress, inhibited the activation of IκBα and p65, regulated autophagy, and reduced the expression levels of pro-inflammatory cytokines. Further, when we treated BVDV-infected cells with the ER stress inducer thapsigargin, it led to significant activation of the NF-κB pathway and autophagy. Conversely, treating the cells with the ER stress inhibitor 4-phenylbutyric acid reversed these effects. These findings suggest that melatonin exerts its antiviral effects primarily through the PERK-eIF2α-ATF4 of ER stress-mediated NF-κB pathway and autophagy. Overall, our study underscores the potential of melatonin as an effective protective and therapeutic option against BVDV, offering insights into its anti-infective mechanisms.

Comparative analysis of noise and music exposure on inflammatory responses on lipopolysaccharide-induced septic rats.

OBJECTIVE: Environmental factors such as noise and music can significantly impact physiological responses, including inflammation. This study explored how environmental factors like noise and music affect lipopolysaccharide (LPS)-induced inflammation, with a focus on systemic and organ-specific responses. MATERIALS AND METHODS: 24 Wistar rats were divided into four groups (n = 6 per group): Control group, LPS group, noise-exposed group, and music-exposed group. All rats, except for the Control group, received 10 mg/kg LPS intraperitoneally. The rats in the noise-exposed group were exposed to 95 dB noise, and the music-exposed group listened to Mozart's K. 448 music (65-75 dB) for 1 h daily over 7 days. An enzyme-linked immunosorbent assay was utilized to detect the levels of inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß), in serum and tissues (lung, liver, and kidney). Western blot examined the phosphorylation levels of nuclear factor-κB (NF-κB) p65 in organ tissues. RESULTS: Compared with the Control group, LPS-induced sepsis rats displayed a significant increase in the levels of TNF-α and IL-1ß in serum, lung, liver, and kidney tissues, as well as a remarkable elevation in the p-NF-κB p65 protein expression in lung, liver, and kidney tissues. Noise exposure further amplified these inflammatory markers, while music exposure reduced them in LPS-induced sepsis rats. CONCLUSION: Noise exposure exacerbates inflammation by activating the NF-κB pathway, leading to the up-regulation of inflammatory markers during sepsis. On the contrary, music exposure inhibits NF-κB signaling, indicating a potential therapeutic effect in reducing inflammation.

Caffeic acid phenethyl ester attenuates Enterococcus faecalis infection in vivo: antioxidants and NF-κB have a protective role against stomach damage.

The mammalian gastrointestinal tract hosts a significant microbial symbiont community, an intriguing feature of this complex organ system. This study aimed to investigate the anti-inflammatory, antioxidant, and protective effects of caffeic acid phenethyl ester (CAPE) against Enterococcus faecalis infection in the stomach at a dose of 106 CFU in Swiss mice. A total of 30 mice were randomly assigned to three groups of ten mice each. Group I was the negative control, Group II was infected orally with E. faecalis for 18 days, and Group III was infected with E. faecalis and treated with CAPE orally at a daily dose of 4 mg/kg for 18 days. We assessed the antioxidant activities of stomach homogenate and the immunohistochemical expressions of the transcription factor nuclear factor kappa B (NF-κB) and proliferating cell nuclear antigen (PCNA). Histopathological examination was performed on the stomachs of all mice. Group II had decreased levels of antioxidant activity and positive expressions of NF-κB and PCNA. Histological observations revealed an increase in mucosal and glandular thickness compared with Group I. Group III, treated with CAPE, showed a significant increase in antioxidant activities and a significant decrease in NF-κB and PCNA immunoreactivities compared with Group II. In addition, Group III showed restoration of the normal thickness of the non-glandular and glandular parts of the stomach. Our results revealed that E. faecalis infection has damaging effects on the stomach and proved that CAPE has promising protective, anti-inflammatory, and antioxidant effects against E. faecalis. Further studies may investigate the potential therapeutic effects of CAPE against E. faecalis infection.

Basal-to-inflammatory transition and tumor resistance via crosstalk with a pro-inflammatory stromal niche.

Cancer-associated inflammation is a double-edged sword possessing both pro- and anti-tumor properties through ill-defined tumor-immune dynamics. While we previously identified a carcinoma tumor-intrinsic resistance pathway, basal-to-squamous cell carcinoma transition, here, employing a multipronged single-cell and spatial-omics approach, we identify an inflammation and therapy-enriched tumor state we term basal-to-inflammatory transition. Basal-to-inflammatory transition signature correlates with poor overall patient survival in many epithelial tumors. Basal-to-squamous cell carcinoma transition and basal-to-inflammatory transition occur in adjacent but distinct regions of a single tumor: basal-to-squamous cell carcinoma transition arises within the core tumor nodule, while basal-to-inflammatory transition emerges from a specialized inflammatory environment defined by a tumor-associated TREM1 myeloid signature. TREM1 myeloid-derived cytokines IL1 and OSM induce basal-to-inflammatory transition in vitro and in vivo through NF-κB, lowering sensitivity of patient basal cell carcinoma explant tumors to Smoothened inhibitor treatment. This work deepens our knowledge of the heterogeneous local tumor microenvironment and nominates basal-to-inflammatory transition as a drug-resistant but targetable tumor state driven by a specialized inflammatory microenvironment.

Thymol and p-Cymene Protect the Liver by Mitigating Oxidative Stress, Suppressing TNF-α/NF-κB, and Enhancing Nrf2/HO-1 Expression in Immobilized Rats.

This study aimed to investigate the effects of the monoterpenes thymol and p-cymene on the liver of rats subjected to prolonged immobilization stress and to discover the possible mechanism behind this effect. For 14 consecutive days, the rats were placed in a restrainer for 2.5 h every day to expose them to stress. During the same period, thymol (10 mg/kg, gavage) and p-cymene (50 mg/kg, intraperitoneally) were also administered. Thymol and p-cymene prevented the increase in malondialdehyde levels and the decrease in glutathione content in the liver of rats exposed to chronic immobility. They also increased the activity of the glutathione peroxidase enzyme in the liver of stressed animals, but only thymol could increase the activity of superoxide dismutase. These monoterpenes reduced the expression of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, and IL-6 and nuclear factor kappa B (NF-κB) in the liver of stressed animals. They increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Thymol and p-cymene greatly prevented the infiltration of inflammatory cells in the liver parenchyma of stressed rats. In conclusion, the study found that thymol and p-cymene have a hepatoprotective effect on immobilized rats, likely exerted by suppressing oxidative stress and inflammation, stimulating Nrf2/HO-1 signaling, and inhibiting the TNF-α/NF-κB pathway.

Disulfiram attenuates cell and tissue damage and blood‒brain barrier dysfunction after intracranial haemorrhage by inhibiting the classical pyroptosis pathway.

No single treatment significantly reduces the mortality rate and improves neurological outcomes after intracerebral haemorrhage (ICH). New evidence suggests that pyroptosis-specific proteins are highly expressed in the perihaematomal tissues of patients with ICH and that the disulfiram (DSF) inhibits pyroptosis. An ICH model was established in C57BL/6 mice by intracranial injection of collagenase, after which DSF was used to treat the mice. Cell model of ICH was constructed, and DSF was used to treat the cells. HE, TUNEL, Nissl, FJC and IF staining were performed to evaluate the morphology of brain tissues; Western blotting and ELISA were performed to measure the protein expression of NOD-like receptor protein 3 (NLRP3)/Caspase-1/gasdermin D (GSDMD) classical pyroptosis pathway and Toll-likereceptor4 (TLR4)/nuclear factor-kappaB (NF-κB) inflammatory signaling pathway and blood‒brain barrier-associated factoes, and the wet/dry weight method was used to determine the brain water content. The expression of proteins related to the NLRP3/Caspase-1/GSDMD pathway and the TLR4/NF-κB pathway was upregulated in tissues surrounding the haematoma compared with that in control tissues; Moreover, the expression of the blood-brain barrier structural proteins occludin and zonula occludens-1 (ZO-1) was downregulated, and the expression of Aquaporin Protein-4 (AQP4) and matrix metalloprotein 9 (MMP-9) was upregulated. DSF significantly inhibited these changes, reduced the haematoma volume, decreased the brain water content, reduced neuronal death and degeneration and improved neurological function after ICH. ICH activated the classical pyroptosis pathway and TLR4/NF-κB inflammatory pathway, disruped the expression of blood-brain barrier structural proteins, and exacerbated brain injury and neurological dysfunction. DSF inhibited these changes and exerted the therapeutic effects on pathological changes and dysfunction caused by ICH.

Protective effect of carvacrol hydrogel on the alveolar bone in rats with periodontitis.

OBJECTIVES: This study aimed to investigate the protective effect and mechanism of carvacrol hydrogel on the alveolar bone in rats with periodontitis. METHODS: A thermosensitive hydrogel supported by carvacrol was prepared using poloxamer and hydroxypropyl methyl cellulose as matrix. SD rats were randomly divided into blank group, periodontitis group, blank hydrogel group, and low-, medium-, and high-dose hydrogel groups. The periodontitis symptoms and the CT structure of the alveolar bone were observed. The changes in liver, spleen, kidney, and periodontal tissues were observed. The related indexes of bone metabolism in serum were detected. The expression of osteoprotegerin (OPG) and nuclear transcription factor-κB (NF-κB) pathway proteins was determined by Western blot. The levels of inflammatory factors were assessed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: Carvacrol hydrogel had good slow release, biocompatibility, and cell adhesion. The periodontitis of rats in the carvacrol hydrogel group was significantly alleviated, the expression of OPG protein in gingival tissue was significantly increased (P<0.01), and the levels of receptor activator of NF-κB ligand (RANKL), receptor activator of NF-κB (RANK), NF-κB protein, and inflammatory factors were significantly decreased (P<0.01). CONCLUSIONS: Carvacrol hydrogel can regulate the OPG and NF-κB pathways, reduce alveolar bone absorption, and improve periodontal inflammation.

Palmitic acid promotes miRNA release from adipocyte exosomes by activating NF-κB/ER stress.

OBJECTIVE: The release of adipose tissue-derived miRNAs is increased under conditions of obesity, but the exact molecular mechanisms involved have not been elucidated. This study investigated whether obesity-induced increases in palmitic acid (PA) content could activate the NF-κB/endoplasmic reticulum stress (ER stress) pathway and promote the expression and release of exosomal miRNAs in adipocytes. METHODS: Abdominal adipose tissue and serum samples were collected from normal weight individuals and people with obesity to clarify the correlation of serum PA content with NF-κB/ER stress and the release of exosomal miRNAs. NF-κB and ER stress were blocked in obese mice and in vitro cultured adipocytes to demonstrate the molecular mechanisms by which PA promotes the release of exosomal miRNAs.The morphology, particle size and distribution of the exosomes were observed via transmission electron microscopy and NTA. RESULTS: Accompanied by increased serum PA levels, the NF-κB/ER stress pathway was activated in the adipose tissue of people with obesity and in high-fat diet (HFD)-induced obese mice; moreover, the levels of miRNAs in both adipose tissue and serum were increased. P-p65 (Bay11-7082) and ER stress (TUDCA) blockers significantly reduced the levels of miRNAs in abdominal adipose tissue and serum, decreased blood glucose levels, and improved glucose tolerance and insulin sensitivity in obese mice. In 3T3-L1 adipocytes, high concentrations of PA activated the NF-κB/ER stress pathway and increased the expression and release of miRNAs in exosomes. P-p65 (Bay11-7082) and ER stress (TUDCA) blockers significantly reversed the increased release exosomal miRNAs cause by PA. CONCLUSIONS: Obesity-induced increases in PA content increase the expression and release of miRNAs in adipocyte exosomes by activating the NF-κB/ER stress pathway.

Ameliorative role of catechin to combat against lindane instigated liver toxicity via modulating PI3K/PIP3/Akt, Nrf-2/Keap-1, NF-κB pathway and histological profile.

Lindane (LDN) is a well-known herbicidal drug that exerts deleterious impacts on vital body organs including the liver. Catechin (CTN) is a plant-based flavonoid that demonstrates various pharmacological abilities. This trial was executed to evaluate the ameliorative efficacy of CTN to combat LDN instigated hepatotoxicity in male albino rats (Rattus norvegicus). Thirty-two rats were categorized into four groups including control, LDN (30 mg/kg), LDN (30 mg/kg) + CTN (40 mg/kg) and CTN (40 mg/kg) alone treated group. It was observed that LDN dysregulated the expressions of PI3K/PIP3/Akt and Nrf-2/Keap-1 pathway. Moreover, the activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), heme­oxygenase-1 (HO-1) and glutathione reductase (GSR) were subsided after LDN intoxication. Besides, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), ALT (Alanine aminotransferase), AST (Aspartate transaminase), Gamma-glutamyl transferase (GGT) and ALP (Alkaline phosphatase) were increased whereas reduced the levels of albumin and total proteins in response to LDN exposure. Additionally, LDN administration escalated the levels of Interleukin-6 (IL-6), Nuclear factor kappa-B (NF-κB), Interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and the activity of cyclooxygenase-2 (COX-2). Furthermore, the gene expressions of Bcl-2-associated X protein (Bax) and Cysteinyl aspartate-acid proteases-3 (Caspase-3) were enhanced whereas the expression of B-cell lymphoma-2 (Bcl-2) was lowered following the LDN treatment. LDN instigated various histological impairments in hepatic tissues. Nonetheless, concurrent administration of CTN remarkably ameliorated liver impairments via regulating aforementioned disruptions owing to its antioxidant, anti-apoptotic and histo-protective potentials.

Gypenoside LXXV Alleviates Colitis by Reprograming Macrophage Polarization via the Glucocorticoid Receptor Pathway.

An imbalance in the macrophage phenotype is closely related to various inflammatory diseases. Here, we discovered that gypenoside LXXV (GP-75), a type of saponin from Gynostemma pentaphyllum, can reprogram M1-like macrophages into M2-like ones. On a mechanistic level, GP-75 inhibits NF-κB-COX2 signaling by targeting the glucocorticoid receptor (GR). Administration of GP-75, either orally or by intraperitoneal injection, significantly alleviates ulcerative colitis in mice, a pathogenesis associated with macrophage polarization. Clodronate liposomes, which deplete macrophages in mice, as well as GR antagonist RU486, abrogate the anticolitis effect of GP-75, thus confirming the pivotal role of macrophages in GP-75 function. We also showed that GP-75 has no toxicity in mice. Overall, this is the first report that demonstrates the effect of GP-75 on macrophage reprograming and as an agent against colitis. Because G. pentaphyllum is gaining popularity as a functional food, our findings offer new perspectives on the use of gypenosides as potential nutraceuticals for medical purposes.

DJ-X-013 reduces LPS-induced inflammation, modulates Th17/ myeloid-derived suppressor cells, and alters NF-κB expression to ameliorate experimental colitis.

SCOPE: Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition of unknown etiology, although recent evidence suggests that it is caused by an excessive immune response to mucosal antigens. We determined the anti-inflammatory properties of novel compound DJ-X-013 in vitro in lipopolysaccharide (LPS)-induced macrophages and in an in vivo dextran sodium sulfate (DSS)-induced model of colitis. METHODS AND RESULTS: To evaluate the anti-inflammatory properties of DJ-X-013, we used LPS-activated RAW 264.7 macrophages in vitro and a DSS-induced experimental model of colitis in vivo. We examine cellular morphology, and tissue architecture by histology, flow cytometry, RT-qPCR, multiplex, and immunoblot analysis to perform cellular and molecular studies. DJ-X-013 treatment altered cell morphology and expression of inflammatory cytokines in LPS-activated macrophages as compared to cells treated with LPS alone. DJ-X-013 also impeded the migration of RAW 264.7 macrophages by modulating cytoskeletal organization and suppressed the expression of NF-κB and inflammatory markers as compared to LPS alone. DJ-X-013 treatment improved body weight, and colon length and attenuated inflammation in the colon of DSS-induced colitis. Intriguingly, DSS-challenged mice treated with DJ-X-013 induced the numbers of myeloid-derived suppressor cells (MDSCs), dendritic cells (DCs), and natural killer T cells (NKT) in the colon lamina propria (LP) relative to DSS. DJ-X-013 also reduced the influx of neutrophils, TNF-α producing macrophages, restricted the number of Th17 cells, and suppressed inflammatory cytokines and NF-κB in the LP relative to DSS. CONCLUSION: DJ-X-013 is proposed to be a therapeutic strategy for ameliorating inflammation and experimental colitis.

Kynurenine Attenuates Ulcerative Colitis Mediated by the Aryl Hydrocarbon Receptor.

The higher prevalence of ulcerative colitis (UC) and the side effects of its therapeutic agents contribute to finding novel treatments. This study aimed to investigate whether kynurenine (KYN), a tryptophan metabolite, has the possibility of alleviating UC and further clarifying the underlying mechanism. The effect of KYN on treating UC was evaluated by intestinal pathology, inflammatory cytokines, and tight-junction proteins in colitis mice and LPS-stimulated Caco-2 cells. Our results revealed that KYN relieved pathological symptoms of UC, improved intestinal barrier function, enhanced AhR expression, and inhibited NF-κB signaling pathway activation in the colon of colitis mice. Moreover, the improved intestinal barrier function, the decreased inflammasome production, and the inhibited activation of the NF-κB signaling pathway by KYN were dependent on AhR in Caco-2 cells. KYN could trigger AhR activation, inactivate the NF-κB signaling pathway, and inhibit NLRP3 inflammasome production, thus alleviating intestinal epithelial barrier dysfunction and reducing intestinal inflammation. In conclusion, the present study reveals that KYN ameliorates UC by improving the intestinal epithelial barrier and activating the AhR-NF-κB-NLRP3 signaling pathway, and it can be a promising therapeutic agent and dietary supplement for alleviating UC.

Sodium houttuyfonate induces bacterial lipopolysaccharide shedding to promote macrophage M1 polarization against acute bacterial lung infection.

Sodium houttuyfonate (SH), derived from the widely utilized natural herb Houttuynia cordata, exhibits an effective therapeutic effect on various diseases, including bacterial and fungal infections, especially the respiratory tract infection. Therefore, the anti-microbial mechanisms of SH may be different from the single-target action mechanism of conventional antibiotics, and further research is needed to clarify this. Firstly, we discovered that SH can effectively intervene in mouse lung infections by reducing bacterial load and acute inflammation response related to pneumonia caused by Pseudomonas aeruginosa. Interestingly, our results confirmed that SH has surface activity and can directly induce changes in the cell wall the shedding of surface lipopolysaccharide (LPS). Additionally, we found that SH-induced shedding of LPS can induce M1 polarization of macrophages in the early stage, leading to the production of corresponding polarization effector molecules. Subsequently, we discovered that SH-induced M1 polarization cells can effectively phagocytose and kill bacterial cells. The protein expression results indicated that SH can enhance the expression of M1 polarization pathway of TLR4/MyD88/NF-κB during the initial phase of macrophage and pathogen interaction. In summary, our results imply that SH could directly induce the shedding of P. aeruginosa LPS in a surfactant-like manner. Afterwards, the SH induced abscisic LPS can initiate the TLR4/MyD88/NF-κB immune pathway to trigger the M1 polarization of macrophages, which might intervene the P. aeruginosa-caused acute lung infection at early stage. Based on these findings, we attempted to coin the term "immune feedback eradication mechanism against pathogen of natural product" to describe this potent antimicrobial mechanism of SH.

NF-κB and TET2 promote macrophage reprogramming in hypoxia that overrides the immunosuppressive effects of the tumor microenvironment.

Macrophages orchestrate tissue homeostasis and immunity. In the tumor microenvironment (TME), macrophage presence is largely associated with poor prognosis because of their reprogramming into immunosuppressive cells. We investigated the effects of hypoxia, a TME-associated feature, on the functional, epigenetic, and transcriptional reprogramming of macrophages and found that hypoxia boosts their immunogenicity. Hypoxic inflammatory macrophages are characterized by a cluster of proinflammatory genes undergoing ten-eleven translocation-mediated DNA demethylation and overexpression. These genes are regulated by NF-κB, while HIF1α dominates the transcriptional reprogramming, demonstrated through ChIP-seq and pharmacological inhibition. In bladder and ovarian carcinomas, hypoxic inflammatory macrophages are enriched in immune-infiltrated tumors, correlating with better patient prognoses. Coculture assays and cell-cell communication analyses support that hypoxic-activated macrophages enhance T cell-mediated responses. The NF-κB-associated hypomethylation signature is displayed by a subset of hypoxic inflammatory macrophages, isolated from ovarian tumors. Our results challenge paradigms regarding the effects of hypoxia on macrophages and highlight actionable target cells to modulate anticancer immune responses.

ACSL6-activated IL-18R1-NF-κB promotes IL-18-mediated tumor immune evasion and tumor progression.

Aberrant activation of IL-18 signaling regulates tumor immune evasion and progression. However, the underlying mechanism remains unclear. Here, we report that long-chain acyl-CoA synthase 6 (ACSL6) is highly expressed in liver cancer and correlated with poor prognosis. ACSL6 promotes tumor growth, metastasis, and immune evasion mediated by IL-18, independent of its metabolic enzyme activity. Mechanistically, upon IL-18 stimulation, ACSL6 is phosphorylated by ERK2 at S674 and recruits IL-18RAP to interact with IL-18R1, thereby reinforcing the IL-18R1-IL-18RAP heterodimer and triggering NF-κB-dependent gene expression to facilitate tumor development. Furthermore, the up-regulation of CXCL1 and CXCL5 by ACSL6 promotes tumor-associated neutrophil and tumor-associated macrophage recruitment, thereby inhibiting cytotoxic CD8+ T cell infiltration. Ablation or S674A mutation of ACSL6 potentiated anti-PD-1 therapeutic efficacy by increasing the effector activity of intertumoral CD8+ T cells. We revealed that ACSL6 is a potential adaptor that activates IL-18-NF-κB axis-mediated tumor immune evasion and provides valuable insights for developing effective immunotherapy strategies for cancer.