Modulating NF-κB Signaling Pathways Research Articles

ITF2357 regulates NF-κB signaling pathway to protect barrier integrity in retinal pigment epithelial cells.

The robust integrity of the retinal pigment epithelium (RPE), which contributes to the outer brain retina barrier (oBRB), is compromised in several retinal degenerative and vascular disorders, including diabetic macular edema (DME). This study evaluates the role of a new generation of histone deacetylase inhibitor (HDACi), ITF2357, in regulating outer blood-retinal barrier function and investigates the underlying mechanism of action in inhibiting TNFα-induced damage to RPE integrity. Using the immortalized RPE cell line (ARPE-19), ITF2357 was found to be non-toxic between 50 nM and 5 μM concentrations. When applied as a pre-treatment in conjunction with an inflammatory cytokine, TNFα, the HDACi was safe and effective in preventing epithelial permeability by fortifying tight junction (ZO-1, -2, -3, occludin, claudin-1, -2, -3, -5, -19) and adherens junction (E-cadherin, Nectin-1) protein expression post-TNFα stress. Mechanistically, ITF2357 depicted a late action at 24 h via attenuating IKK, IκBα, and p65 phosphorylation and ameliorated the expression of IL-1β, IL-6, and MCP-1. Also, ITF2357 delayed IκBα synthesis and turnover. The use of Bay 11-7082 and MG132 further uncovered a possible role for ITF2357 in non-canonical NF-κB activation. Overall, this study revealed the protection effects of ITF2357 by regulating the turnover of tight and adherens junction proteins and modulating NF-κB signaling pathway in the presence of an inflammatory stressor, making it a potential therapeutic application for retinal vascular diseases such as DME with compromised outer blood-retinal barrier.

Non-coding RNA LINC01010 regulates macrophage polarization and innate immune functions by modulating NFκB signaling pathway.

Innate immune response is regulated by tissue resident or infiltrating immune cells such as macrophages (Mφ) that play critical role in tissue development, homeostasis, and repair of damaged tissue. However, the epigenetic mechanisms that regulate Mφ plasticity and innate immune functions are not well understood. Long non-coding RNA (lncRNA) are among the most abundant class of transcriptome but their function in myeloid cell biology is less explored. In this study, we deciphered the regulatory role of previously uncharacterized lncRNAs in Mφ polarization and innate immune responses. Two lncRNAs showed notable changes in their levels during M1 and M2 Mφ differentiation. Our findings indicate that LINC01010 expression increased and AC007032 expression decreased significantly. LINC01010 exhibit myeloid cell-specificity, while AC007032.1 is ubiquitous and expressed in both myeloid and lymphoid (T cells, B cells and NK cells) cells. Expression of these lncRNAs is dysregulated in periodontal disease (PD), a microbial biofilm-induced immune disease, and responsive to lipopolysaccharide (LPS) from different oral and non-oral bacteria. Knockdown of LINC01010 but not AC007032.1 reduced the surface expression of Mφ differentiation markers CD206 and CD68, and M1Mφ polarization markers MHCII and CD32. Furthermore, LINC01010 RNAi attenuated bacterial phagocytosis, antigen processing and cytokine secretion suggesting its key function in innate immunity. Mechanistically, LINC01010 knockdown Mφ treated withEscherichia coli LPS exhibit significantly reduced expression of multiple nuclear factor kappa B pathway genes. Together, our data highlight functional role of a PD-associated lncRNA LINC01010 in shaping macrophage differentiation, polarization, and innate immune activation.

Sphingomyelin synthase 2 promotes the stemness of breast cancer cells via modulating NF-κB signaling pathway

ObjectivesMulti-drug resistance (MDR) to chemotherapy is the main obstacle influencing the anti-tumor effect in breast cancer, which might lead to the metastasis and recurrence of cancer. Until now, there are still no effective methods that can overcome MDR. In this study, we aimed to investigate the role of sphingomyelin synthase 2 (SMS2) in breast cancer resistance.MethodsQuantitative RT-PCR analysis was performed to assess changes in mRNA expression. Western blot analysis was performed to detect protein expression. Inhibitory concentration value of adriamycin (ADR) was evaluated using CCK 8 assay. The stemness ability of breast cancer cells was assessed by spheroid-formation assay. Immunofluorescence staining was conducted to show the cellular distribution of proteins. Breast tumor masses were harvested from the xenograft tumor mouse model.ResultsSMS2 overexpression increased the IC50 values of breast cancer cells. SMS2 decreased the CD24 transcription level but increased the transcription levels of stemness-related genes including CD44, ALDH, OCT 4 and SOX2 in breast cancer cells. SMS2 overexpression promoted the nuclear translocation of phosphorylated NF-κB, while suppression of SMS2 could inhibit the NF-κB pathway.ConclusionsSMS2 increased the stemness of breast cancer cells via NF-κB signaling pathway, leading to resistance to the chemotherapeutic drug ADR. Thus, SMS2 might play a critical role in the development of breast cancer resistance, which is a previously unrecognized mechanism in breast cancer MDR development.

Ogt-mediated O-GlcNAcylation inhibits astrocytes activation through modulating NF-κB signaling pathway

Previous studies have shown that Ogt-mediated O-GlcNAcylation is essential for neuronal development and function. However, the function of O-GlcNAc transferase (Ogt) and O-GlcNAcylation in astrocytes remains largely unknown. Here we show that Ogt deficiency induces inflammatory activation of astrocytes in vivo and in vitro, and impairs cognitive function of mice. The restoration of O-GlcNAcylation via GlcNAc supplementation inhibits the activation of astrocytes, inflammation and improves the impaired cognitive function of Ogt deficient mice. Mechanistically, Ogt interacts with NF-κB p65 and catalyzes the O-GlcNAcylation of NF-κB p65 in astrocytes. Ogt deficiency induces the activation of NF-κB signaling pathway by promoting Gsk3β binding. Moreover, Ogt depletion induces the activation of astrocytes derived from human induced pluripotent stem cells. The restoration of O-GlcNAcylation inhibits the activation of astrocytes, inflammation and reduces Aβ plaque of AD mice in vitro and in vivo. Collectively, our study reveals a critical function of Ogt-mediated O-GlcNAcylation in astrocytes through regulating NF-κB signaling pathway.

Anti-Inflammatory Effect of Garcinol Extracted from Garcinia dulcis via Modulating NF-κB Signaling Pathway.

Garcinia is a significant medicinal plant with many beneficial phytoconstituents, including garcinol. This study investigated the anti-inflammatory effect of garcinol isolated from Garcinia dulcis fruit in LPS-activated THP-1 and Raw 264.7 macrophages. The results demonstrated that the low concentration of garcinol did not alter cell viability. Furthermore, co-incubation of garcinol with LPS inhibited the production of pro-inflammatory cytokines, including TNF-α, IL-8, IL-6, IL-1β, and pro-inflammatory mediators, including iNOS and COX-2 at the mRNA and protein expression levels. Garcinol also decreased the secretion of TNF-α, IL-6, IL-1β, PGE2, and NO. Moreover, the anti-inflammatory effects involved an alteration in the NF-κB signaling pathway. Downregulation of pIKKα/β, pIκBα, and pNF-κB was observed, hence reducing the translocation of pNF-κB from the cytosol into the nucleus, which subsequently decreased the production of pro-inflammatory molecules. Therefore, garcinol isolated from Garcinia dulcis is a potential candidate as an anti-inflammatory agent for inflammation-related disease treatment.

A Nanocurcumin and Pyrroloquinoline Quinone Formulation Prevents Hypobaric Hypoxia-Induced Skeletal Muscle Atrophy by Modulating NF-κB Signaling Pathway.

Kushwaha, Asha D., and Deepika Saraswat. A nanocurcumin and pyrroloquinoline quinone formulation prevents hypobaric hypoxia-induced skeletal muscle atrophy by modulating NF-κB signaling pathway. High Alt Med Biol. 23:249-263, 2022. Background: Hypobaric hypoxia (HH)-induced deleterious skeletal muscle damage depends on exposure time and availability of oxygen at cellular level, which eventually can limit human work performance at high altitude (HA). Despite the advancements made in pharmacological (performance enhancer, antioxidants) and nonpharmacological therapeutics (acclimatization strategies), only partial success has been achieved in improving physical performance at HA. A distinctive combination of nanocurcumin (NC) and pyrroloquinoline quinone (PQQ) has been formulated (named NCF [nanocurcumin formulation], Indian patent No. 302877) in our laboratory, and has proven very promising in improving cardiomyocyte adaptation to chronic HH. We hypothesized that NCF might improve skeletal muscle adaptation and could be a performance enhancer at HA. Material and Methods: Adult Sprague-Dawley rats (220 ± 10 g) were divided into five groups (n = 6/group): normoxia vehicle control, hypoxia vehicle control, hypoxia NCF, hypoxia NC, and hypoxia PQQ. All the animals (except those in normoxia) were exposed to simulated HH in a chamber at temperature 22°C ± 2°C, humidity 50% ± 5%, altitude 25,000 ft for 1, 3, or 7 days. After completion of the stipulated exposure time, gastrocnemius and soleus muscles were excised from animals for further analysis. Results: Greater lengths of hypoxic exposure caused progressively increased muscle ring finger-1 (MuRF-1; p < 0.01) expression and calpain activation (0.56 ± 0.05 vs. 0.13 ± 0.02 and 0.44 ± 0.03 vs. 0.12 ± 0.021) by day 7, respectively in the gastrocnemius and soleus muscles. Myosin heavy chain type I (slow oxidative) fibers significantly (p > 0.01) decreased in gastrocnemius (>50%) and soleus (>46%) muscles by the seventh day of exposure. NCF supplementation showed (p ≤ 0.05) tremendous improvement in skeletal muscle acclimatization through effective alleviation of oxidative damage, and changes in calpain activity and atrophic markers at HA compared with hypoxia control or treatment alone with NC/PQQ. Conclusion: Thus, NCF-mediated anti-oxidative, anti-inflammatory effects lead to decreased proteolysis resulting in mitigated skeletal muscle atrophy under HH.

LINC01534/miR-135b-5p/PTPRT axis regulates inflammatory response in loosening total hip replacement via modulating NF-κB signaling pathway

Aseptic loosening after total hip replacement brings adverse health outcomes and increased risk for complications. The resorptive activity of inflammatory cells activated by the presence of wear-generated debris plays a critical role in debris-induced osteolysis. Previous studies indicate that the abnormally expressed LINC01534 plays a critical role in inflammatory responses. In this study, we aimed to elucidate the functional role and underlying mechanism of LINC01534 in debris-induced osteolysis. We first confirmed that LINC01534 was highly expressed in hip cartilage tissues from aseptic loosening patients. By using an IL-1β-induced inflammation model mimicking debris-induced osteolysis, we demonstrated that LINC01534 promoted IL-1β-induced inflammatory response in hip chondrocytes. Knockdown of LINC01534 inhibited the expression of inflammatory IL-6, IL-8, and TNF-α in hip chondrocytes. Our results showed that LINC01534 functioned as a competing endogenous RNA (ceRNA) by sponging miR-135b-5p in hip chondrocytes. Moreover, bioinformatics analysis and luciferase reporter assay demonstrated that CCHC-Type Zinc Finger Nucleic Acid Binding Protein (PTPRT) is a downstream target of miR-135b-5p. Knockdown of PTPRT attenuated the IL-1β-induced inflammatory responses in hip chondrocytes. In addition, we revealed that inhibition of miR-135b-5p or overexpression of PTPRT could antagonize the effects of LINC01534 knockdown on inflammation attenuation in hip chondrocytes. Mechanistically, we demonstrated that LINC01534/miR-135b-5p/PTPRT axis regulated the NF-κB signaling pathway in hip chondrocytes. Taken together, our findings suggest that LINC01534/miR-135b-5p/PTPRT axis might be a valuable therapeutic target for the treatment of debris-induced osteolysis.

Algae-derived polysaccharides supplementation ameliorates heat stress-induced impairment of bursa of Fabricius via modulating NF-κB signaling pathway in broilers

This study aimed to investigate the protective effects of dietary algae-derived polysaccharides (ADP) from Enteromorpha prolifera against heat stress (HS)-induced bursa of Fabricius injure in broilers, and to elucidate the molecular mechanisms underlying the protective effect. A total of 144 8-week-old male yellow-feathered broilers were randomly allocated into 3 treatments of 6 replicates each (8 broilers per replicate): thermoneutral zone group (TN, fed basal diet); heat stress group (HS, fed basal diet); heat stress + ADP group (HSA, basal diet supplemented with 1,000 mg/kg ADP). Broilers in TN group were raised at 23.6 ± 1.8°C during the whole study. Broilers in HS and HSA groups were exposed to 33.2 ± 1.5°C for 10 h/day. The experimental period lasted for four weeks. The results showed that HS and dietary ADP had no significant effects on bursa of Fabricius index (P > 0.05). HS exposure increased the apoptosis rate of bursa of Fabricius (P < 0.05), and the apoptosis rate was reduced by dietary ADP (P < 0.05). Besides, broilers in HS and HSA groups had a lower glutathione-S transferase (GST) activity and total anti-oxidation capacity (T-AOC), whereas had a higher malondialdehyde (MDA) levels of bursa of Fabricius than those in TN group (P < 0.05). HS exposure elevated the concentration of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-4, and IL-6, while decreased the concentration of interferon-γ (INF-γ) and IL-2 (P < 0.05), and dietary inclusion of ADP reduced the IL-1β level and increased the IL-2 level of bursa of Fabricius (P < 0.05). Compared with TN group, broilers in HS and HSA groups had lower relative mRNA expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and GSTT1 in bursa of Fabricius (P < 0.05). Additionally, HS exposure down-regulated the mRNA expression of inhibitor kappa B alpha (IκBα), IFN-γ, and IL-2, while up-regulated the mRNA expression of nuclear factor-kappa B (NF-κB) p65, TNF-α, IL-1β, and IL-6 in bursa of Fabricius (P < 0.05). However, dietary inclusion of ADP up-regulated the mRNA expression of IκBα and down-regulated the mRNA expression of NF-κB p65, TNF-α, and IL-6 in bursa of Fabricius (P < 0.05). Furthermore, HS exposure increased the relative protein expression levels of total and nuclear NF-κB p65 (P < 0.05), but dietary ADP supplementation reduced the relative protein expression levels of total and nuclear NF-κB p65 in bursa of Fabricius (P < 0.05). Collectively, dietary ADP ameliorated the impairment of histology, cell apoptosis and immune balance in bursa of Fabricius of heat stressed broilers, which is involved in modulation of NF-κB signaling pathway.

UCHL1 inhibition attenuates cardiac fibrosis via modulation of nuclear factor-κB signaling in fibroblasts

The ubiquitin-proteasome system (UPS) plays an essential role in cellular homeostasis and myocardial function. Ubiquitin carboxy-terminal hydrolase 1 (UCHL1) is involved in cardiac remodeling, but its underlying mechanisms are largely unknown. Here, we observed that the UCHL1 was significantly up-regulated in angiotensin II-infused heart and primary cardiac fibroblast (CF). Systemic administration of the UCHL1 inhibitor LDN57444 significantly ameliorated cardiac fibrosis and improved cardiac function induced by angiotensin II. Also, LDN57444 inhibited CF cell proliferation as well as attenuated collagen I, and CTGF gene expression in the presence of Ang II. Mechanistically, UCHL1 promotes angiotensin II-induced fibrotic responses by way of activating nuclear factor kappa B (NF-κB) signaling. Moreover, suppression of the NF-κB pathway interfered with UCHL1 overexpression-mediated fibrotic responses. Besides, the chromatin immunoprecipitation assay demonstrated that NF-κB can bind to the UCHL1 promoter and trigger its transcription in cardiac fibroblasts. These findings suggest that UCHL1 positively regulates cardiac fibrosis by modulating NF-κB signaling pathway and identify UCHL1 could be a new treatment strategy for cardiac fibrosis.

Characterization and immune function of decapentaplegic (Dpp) gene from the oriental river prawn, Macrobrachium nipponense

The Decapentaplegic (Dpp) gene, which belongs to the TGF‐β superfamily, is involved in multiple developmental processes in eukaryotic species. In this study, we firstly identified and characterized Dpp from Macrobrachium nipponense. Its full-length open reading frame (ORF) cDNA was 1332 bp, encoding 443 amino acids. The putative MnDpp protein contained a signal peptide, a TGF-β propeptide region and a TGF-β domain. Its TGF-β domain was highly conserved from vertebrates to invertebrates, and exhibited highly similarity to Dpp derived from Bombyx mori. qRT-PCR analysis suggested that MnDpp expressed in all tested tissues and responded to both bacterial and virus pathogens, indicating MnDpp was involved in the innate immune response of M. nipponense. Knockdown of MnDppin vivo significantly increased bacteria growth and markedly decreased the expressions of NF-κB signaling genes including dorsal, relish, TAK1, TAB1, Ikkβ and Ikkε as well as antimicrobial peptides (AMPs) including ALF2, ALF3, ALF4, ALF5, Cru1 and Cru2. Moreover, in vitro overexpression of MnDpp protein in HEK293T cells further demonstrated that it exerted antibacterial immune response by activation of NF-κB signaling cascade. In summary, these results indicated that MnDpp played an important role in the innate immunity in M. nipponense by modulating NF-κB signaling pathway, which might provide new insights about Dpp in crustaceans and paved the way for a better understanding of the crustacean innate immune system.

A20 Restricts Inflammatory Response and Desensitizes Gingival Keratinocytes to Apoptosis.

The pathophysiology of periodontal disease involves a perturbed immune system to a dysbiotic microflora leading to unrestrained inflammation, collateral tissue damage, and various systemic complications. Gingival epithelial cells function as an important part of immunity to restrict microbial invasion and orchestrate the subsequent innate responses. A20 (TNFAIP3), an ubiquitin-editing enzyme, is one of the key regulators of inflammation and cell death in numerous tissues including gastrointestinal tract, skin, and lungs. Emerging evidence indicates A20 as an essential molecule in the oral mucosa as well. In this study, we characterized the role of A20 in human telomerase immortalized gingival keratinocytes (TIGKs) through loss and gain of function assays in preclinical models of periodontitis. Depletion of A20 through gene editing in TIGKs significantly increased IL-6 and IL-8 secretion in response to Porphyromonas gingivalis infection while A20 over-expression dampened the cytokine production compared to A20 competent cells through modulating NF-κB signaling pathway. In the subsequent experiments which assessed apoptosis, A20 depleted TIGKs displayed increased levels of cleaved caspase 3 and DNA fragmentation following P. gingivalis infection and TNF/CHX challenge compared to A20 competent cells. Consistently, there was reduced apoptosis in the cells overexpressing A20 compared to the control cells expressing GFP further substantiating the role of A20 in regulating gingival epithelial cell fate in response to exogenous insult. Collectively, our findings reveal first systematic evidence and demonstrate that A20 acts as a regulator of inflammatory response in gingival keratinocytes through its effect on NF-κB signaling and desensitizes cells to bacteria and cytokine induced apoptosis in the oral mucosa. As altered A20 levels can have profound effect on different cellular responses, future studies will determine whether A20-targeted therapies can be exploited to restrain periodontal inflammation and maintain oral mucosa tissue homeostasis.

Astragalus propinquus Schischkin and Panax notoginseng (A&P) compound relieved cisplatin-induced acute kidney injury through inhibiting the mincle maintained macrophage inflammation

Ethnopharmacological relevanceAcute kidney injury (AKI) is a common disease in hospitalized patients, especially in critically ill patients. It is characterised with high morbidity and mortality, and is also an important cause of chronic kidney disease and chronic renal failure. Astragalus propinquus Schischkin and Panax notoginseng (A&P) compound, a famous traditional Chinese medicine, consists of Astragalus propinquus Schischkin, Panax notoginseng, Angelica sinensis, Achyranthes bidentata, and Ecklonia kurome, has been widely used for the treatment of various kidney diseases in the southwest of China. However, the effects of A&P on treatment of AKI and its underlying mechanism are needed to be uncovered. Aim of the studyRecent researches reported that Mincle (Macrophage-inducible C-type lectin) plays a key role in renal injury of AKI by regulating the expression and secretion of inflammatory cytokines on macrophage through modulating NF-κB signaling pathway. Here, we aimed to investigate the renoprotective effect of A&P on AKI and whether by inhibiting Mincle. Materials and methodsWe established a lipopolysaccharide (LPS)-induced Bone Marrow-Derived Macrophage (BMDM) inflammatory cell model and a cisplatin-induced mouse AKI model in vitro and in vivo. Renal histopathology staining was performed to observe kidney morphology. The expression and secretion of inflammatory cytokines were detected by real-time PCR and Enzyme-linked immunosorbent assay. Western blotting was used to detect the protein levels and Flow cytometry performed to detect polarization of macrophage. ResultsThe results showed that A&P significantly reduced the mRNA expression of IL-1β, IL-6, TNFα and MCP-1 in LPS-stimulated BMDM cells, and secretion of IL-1β and IL-6 in supernatant. The same results were found in Cisplatin-induced AKI kidney and serum after treatment with A&P. The data also showed that A&P strongly reduced the mRNA and protein levels of Mincle in vitro and vivo, and also inhibited the activation of Syk and NF-κB. Notably, A&P down-regulated the M1 macrophage marker iNOS, which may relate to the inhibition of Mincle. Interestingly, both overexpression of Mincle by transfection of pcDNA3.1-Mincle plasmid and administration of TDB (a ligand of Mincle) can significantly abolished the A&P-inhibited inflammation in BMDM, suggesting Mincle pathway play a key role in macrophage inflammation in AKI. ConclusionOur findings indicated that A&P protected kidney from inhibiting inflammation through down-regulating of Mincle pathway in macrophage in AKI. It provides a potential medicine compound for the treatment of AKI.

Anti-inflammatory properties of fermented pine (Pinus morrisonicola Hay.) needle on lipopolysaccharide-induced inflammation in RAW 264.7 macrophage cells.

This study was aimed to explore the antioxidant and anti-inflammatory activity of various pine needle products (non-fermented, fermented, and commercial) extracted with different solvents (hexane, ethyl acetate, and water) in lipopolysaccharide (LPS) induced RAW 264.7 cells. The phenolic/flavonoid contents of ethyl acetate extract of fermented pine needle (EAE-FPN) is higher than other pine product extracts (hexane/water). The levels of antioxidant indices (TEAC, DPPH) as well as free radical scavenging activity (H2 O2 ) were significantly improved in EAE-FPN than other pine needle product extracts. The levels of ROS and various inflammatory markers (NO, PGE2, TNF-α, and IL-1β/6) were considerably abolished by EAE-FPN in a dose-dependent manner (50-200μg/ml). Moreover, the protein expressions of inducible NO synthase (iNOS), cyclooxygenase 2 (COX-2), and nuclear factor Kappa B (NF-κB) p65 subunit were also markedly downregulated by EAE-FPN. Collectively, EAE-FPN with phenolic/flavonoid content showed excellent antioxidant and anti-inflammatory properties via modulating NF-κB signaling pathway. PRACTICAL APPLICATIONS: Pine needle drink (Pinus morrisonicola Hay) has been used as a functional beverage for many years due to its various biological properties in Asia especially in Taiwan, China, and Korea. Many researchers hinted various biological activity of fermented pine needle product but none of them explored the in-depth mechanism underpinning its antioxidant and anti-inflammatory properties in LPS-induced RAW 264.7 cell model. Hence, the current cell line study was designed to assess the underlying mechanism behind the antioxidant and anti-inflammatory activity of Pine needles extract (both non-fermented and fermented) in LPS-induced RAW 264.7 cells (macrophage). The outcome of this study distinctly showed that EAE-FPN displayed potent antioxidant and anti-inflammatory activities by regulating NF-κB signaling pathway. Therefore, pine needle could be developed into functional drink to abolish the progression of inflammatory responses in various disease condition.

Downregulation of tumor suppressor RACK1 by Helicobacter pylori infection promotes gastric carcinogenesis through the integrin β-1/NF-κB signaling pathway

Receptor of activated protein kinase C 1 (RACK1) is downregulated in gastric cancer and is involved in modulating NF-κB signaling pathway activity. However, the underlying molecular mechanisms regulating RACK1 expression are unclear. In this study, we demonstrated that downregulated expression of RACK1 was observed in gastric cancer tissue compared to adjacent normal tissue and was correlated with poor prognosis in patients. Helicobacter pylori (H. pylori) infection downregulated RACK1 expression in concert with canonical NF-κB signaling pathway activation in vivo and in vitro. RACK1 overexpression suppressed NF-κB signaling pathway activation as well as the release of downstream proinflammatory cytokines. In addition, RACK1 downregulation increased integrin β-1 expression, while integrin β-1 silencing decreased NF-κB signaling activation. Moreover, H. pylori infection downregulated RACK1 but upregulated integrin β-1 expression at the precancerous lesion stages in human subjects. Our data indicate that H. pylori infection promotes the upregulation of integrin β-1 expression via downregulation of RACK1 expression, which subsequently leads to the elevated activation of the NF-κB signaling pathway, an essential step in H. pylori-induced carcinogenesis.

Topical application of glycolic acid suppresses the UVB induced IL-6, IL-8, MCP-1 and COX-2 inflammation by modulating NF-κB signaling pathway in keratinocytes and mice skin

BackgroundGlycolic acid (GA), commonly present in fruits, has been used to treat dermatological diseases. Extensive exposure to solar ultraviolet B (UVB) irradiation plays a crucial role in the induction of skin inflammation. The development of photo prevention from natural materials represents an effective strategy for skin keratinocytes. ObjectiveThe aim of this study was to investigate the molecular mechanisms underlying the glycolic acid (GA)-induced reduction of UVB-mediated inflammatory responses. MethodsWe determined the effects of different concentrations of GA on the inflammatory response of human keratinocytes HaCaT cells and C57BL/6J mice dorsal skin. After GA was topically applied, HaCaT and mice skin were exposed to UVB irradiation. ResultsGA reduced the production of UVB-induced nuclear factor kappa B (NF-κB)-dependent inflammatory mediators [interleukin (IL)-1β, IL-6, IL-8, cyclooxygenase (COX)-2, tumor necrosis factor-α, and monocyte chemoattractant protein (MCP-1)] at both mRNA and protein levels. GA inhibited the UVB-induced promoter activity of NF-κB in HaCaT cells. GA attenuated the elevation of senescence associated with β-galactosidase activity but did not affect the wound migration ability. The topical application of GA inhibited the genes expression of IL-1β, IL-6, IL-8, COX-2, and MCP-1 in UVB-exposed mouse skin. The mice to UVB irradiation after GA was topically applied for 9 consecutive days and reported that 1–1.5% of GA exerted anti-inflammatory effects on mouse skin. ConclusionWe clarified the molecular mechanism of GA protection against UVB-induced inflammation by modulating NF-κB signaling pathways and determined the optimal concentration of GA in mice skin exposed to UVB irradiation.

Serum metabolomics analysis reveals that obvious cardioprotective effects of low dose Sini decoction against isoproterenol-induced myocardial injury in rats

BackgroundSini decoction (SND) is used for cardiovascular disease over thousands of years in China. However, it is still lacking of dose-response relationship of SND in cardiovascular disease at the metabolic level. PurposeThe present study is designed to explore the cardioprotective effects of different dosages of SND pretreatment on the isoproterenol (ISO)-induced myocardial injury and elucidate the mechanism underlying this protective effect. MethodsThe cardioprotective effects of different dosages of SND pretreatment on the isoproterenol-induced myocardial injury were compared through a serum metabolomics approach based on ultraperformance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). In addition, the cardioprotective effects were evaluated by serum biochemical analysis and histopathological examination of myocardial tissue. Finally, in view of the fact that these perturbed bile acid and phospholipid metabolisms are connected with NF-κB signaling pathway, nuclear expression of NF-κB p65 and the activation of NF-κB were analyzed by immunohistochemistry, immunoblotting and electrophoretic mobility shift assay (EMSA), respectively. ResultsThe cardioprotective effect was observed in SND pretreatment groups, especially in low dosage SND group. The results of serum enzyme activities and histopathology were consistent with the above effect. Meanwhile, fifteen latent biomarker candidates were identified involving glucose, phospholipid, bile acid and amino acid metabolisms. Among them, five bile acids including ursodeoxycholic acid, murideoxycholic acid, muricholic acid, hyodeoxycholic acid and cholic acid, were for the first time identified as latent pathological biomarkers related to ISO-induced myocardial injury. Further, different dose SND groups exerted different of inhibition degrees to the activation of NF-κB, which was obvious in the SND-L group. ConclusionThe results revealed that Sini decoction protreatment protects myocardium better at a low dose level and one of possible cardioprotective mechanisms is modulating NF-κB signaling pathway against isoproterenol-induced myocardial injury through regulating phospholipid and bile acid metabolisms.

CD147 regulates extrinsic apoptosis in spermatocytes by modulating NFκB signaling pathways.

CD147 null mutant male mice are infertile with arrested spermatogenesis and increased apoptotic germ cells. Our previous studies have shown that CD147 prevents apoptosis in mouse spermatocytes but not spermatogonia. However, the underlying mechanism remains elusive. In the present study, we aim to determine the CD147-regulated apoptotic pathway in mouse spermatocytes. Our results showed that immunodepletion of CD147 triggered apoptosis through extrinsic apoptotic pathway in mouse testis and spermatocyte cell line (GC-2 cells), accompanied by activation of non-canonical NFκB signaling and suppression of canonical NFκB signaling. Furthermore, CD147 was found to interact with TRAF2, a factor known to regulate NFκB and extrinsic apoptotic signaling, and interfering CD147 led to the decrease of TRAF2. Consistently, depletion of CD147 by CRISPR/Cas9 technique in GC-2 cells down-regulated TRAF2 and resulted in cell death with suppressed canonical NFκB and activated non-canonical NFκB signaling. On the contrary, interfering of CD147 had no effect on NFκB signaling pathways as well as TRAF2 protein level in mouse spermatogonia cell line (GC-1 cells). Taken together, these results suggested that CD147 plays a key role in reducing extrinsic apoptosis in spermatocytes, but not spermatogonia, through modulating NFκB signaling pathway.

MyD88 NEDDylation negatively regulates MyD88-dependent NF-κB signaling through antagonizing its ubiquitination

Myeloid differentiation factor 88 (MyD88) plays a central role in innate immunity response, however, how its activity is tightly regulated remains largely unknown. In this study, we identify MyD88 as a novel substrate of NEDD8, and demonstrate that MyD88 NEDDylation antagonizes its ubiquitination. Interestingly, in response to the stimulation of IL-1β, MyD88 NEDDylation is downregulated while its ubiquitination is upregulated. We also show that deNEDDylase NEDP1 serves as a regulator of this process. Furthermore, we demonstrate that NEDD8 negatively regulates the dimerization of MyD88 and suppresses MyD88-dependent NF-κB signaling. Taken together, this study reveals that NEDDylation of MyD88 regulates NF-κB activity through antagonizing its ubiquitination, suggesting a novel mechanism of modulating NF-κB signaling pathway.

Nanoceria restrains PM2.5-induced metabolic disorder and hypothalamus inflammation by inhibition of astrocytes activation related NF-κB pathway in Nrf2 deficient mice

Increasing studies demonstrated that air pollution (PM2.5) plays a significant role in metabolic and neurological diseases. Unfortunately, there is no direct testimony of this, and yet the molecular mechanism by which the occurrence remains unclear. In this regard, we investigated the role of NF-κB and Nrf2 signaling in PM2.5-induced metabolic disorders and neuroinflammation, and further confirmed whether Nrf2 deficiency promoted PM2.5-induced inflammatory response by up regulating astrocytes activation and nerve injury via modulating NF-κB signaling pathways. Present results found that, indeed, PM2.5 challenges results in glucose tolerance, insulin resistance, dysarteriotony, peripheral inflammation, nerve injury and hypothalamus oxidative stress through astrocytes activation related NF-κB pathway in Nrf2 deficient mice. Moreover, in vitro study, we confirmed that activated astrocytes induced by PM2.5 were involved in pathogenesis of hypothalamic inflammation, which were significantly associated with NF-κB signaling. Nanoceria as potential anti-inflammatory and anti-oxidant stress biomaterial has gained increasing attention. Moderate nanoceria treatment is able to restrain PM2.5-induced metabolic syndrome and inflammation. Inhibition of astrocytes activation related NF-κB and enhancement of Nrf2 by cerium oxide were observed in vivo and in vitro, suggesting cerium oxide inhibited hypothalamic inflammation and nerve injury by altering hypothalamic neuroendocrine alterations and decreasing glial cells activation. In addition, NF-κB inhibitor pyrollidine dithiocarbamate (PDTC) treated primary astrocytes directly determined Nrf2 pathway could be up regulated by dose-dependent nanoceria. These results suggest a new therapeutic approach or target to protect against air pollution related diseases by cerium oxide treatment.

Piperine Ameliorates Lipopolysaccharide-Induced Acute Lung Injury via Modulating NF-κB Signaling Pathways.

Piperine, one of the active components of black pepper, has been reported to have antioxidant and anti-inflammatory activities. However, the effects of piperine on lipolysaccharide (LPS)-induced acute lung injury (ALI) have not been reported. Thus, the protective effects of piperine against LPS-induced ALI were investigated in this study. LPS-induced lung injury was assessed by histological study, myeloperoxidase (MPO) activity, and inflammatory cytokine production. Our results demonstrated that piperine attenuated LPS-induced MPO activity, lung edema, and inflammatory cytokines TNF-α, IL-6, and IL-1β production. Histological studies showed that piperine obviously attenuated LPS-induced lung injury. In addition, piperine significantly inhibited LPS-induced NF-κB activation. In conclusion, our results demonstrated that piperine had a protective effect on LPS-induced ALI. The anti-inflammatory mechanism of piperine is through inhibition of NF-κB activation. Piperine may be a potential therapeutic agent for ALI.