NF-κB Signaling Research Articles

Prolactin protects hippocampal neurons against H2O2-induced neurotoxicity by suppressing BAX and NOX4 via the NF-κB signaling pathway.

Reactive oxygen species (ROS) are physiological byproducts of neuronal metabolism. However, an imbalance between ROS generation and antioxidant capacity, often driven by dysregulated pro-oxidant enzymes like nicotinamide adenine dinucleotide phosphate oxidases (NOX), can result in deleterious oxidative stress. This oxidative stress is a critical factor in the pathogenesis of neurodegenerative diseases. While interventions with broad-spectrum antioxidants have demonstrated limited efficacy, the modulation of endogenous antioxidant mechanisms presents a promising therapeutic avenue. Here, we investigated the potential of the neuroprotective hormone prolactin to mitigate oxidative stress and subsequent neuronal cell death. Prolactin protected primary mouse hippocampal neurons from hydrogen peroxide (H2O2)-induced oxidative damage. Prolactin reduced ROS levels, lipid peroxidation, and apoptosis, and its effects were occluded by a specific prolactin receptor antagonist (G129R-hPRL). Mechanistically, prolactin suppressed H2O2-induced mRNA upregulation of pro-oxidative Nox4 and pro-apoptotic Bax. Moreover, prolactin induced nuclear factor kappa B (NF-κB) nuclear translocation, and the inhibition of the NF-κB signaling pathway abolished the neuroprotective and transcriptional effects of prolactin, indicating its central role in prolactin-mediated protection. Our findings indicate that prolactin exerts potent antioxidant and neuroprotective effects by modulating the expression of Nox4 and Bax, thereby reducing ROS generation and neuronal apoptosis. This study underscores the therapeutic potential of prolactin in attenuating oxidative stress and suggests a possible role in the treatment of neurodegenerative diseases.

Gut commensal Parabacteroides distasonis exerts neuroprotective effects in acute ischemic stroke with hyperuricemia via regulating gut microbiota-gut-brain axis.

Hyperuricemia is considered as an independent risk factor for acute ischemic stroke (AIS), and some AIS patients are accompanied by an increase in serum uric acid. Recent studies have highlighted the important role of gut microbiota in both hyperuricemia and AIS, but there is little available data on the relationship between gut microbiota and the pathogenesis of AIS with hyperuricemia (HAS). Here we profiled the gut microbiota composition in 63 HAS patients and 269 non-HAS patients through 16s rRNA sequencing. Male rat with hyperuricemia were subjected to middle cerebral artery occlusion (MCAO) to establish HAS model and were then treated with Parabacteroides distasonis. Subsequently, the neurological deficit, pathological damages and blood-brain barrier disruption were evaluated. Moreover, the levels of ROS, inflammatory cytokines, NF-𝜿B pathway related protein, and vascular density markers were determined. There were significant differences of gut microbiota composition between HAS patients and non-HAS patients, and a significant decrease in the abundance of Parabacteroides in HAS patients compared to non-HAS patients. Animal experiments showed that supplementation with P. distasonis increased beneficial commensal bacteria, significantly improved neurological deficits, pathological damages and BBB disruption, as well as reduced the level of serum uric acid in HAS rats. We further demonstrated that P. distasonis treatment decreased ROS level and increased SOD2 level, thereby reducing oxidative stress. Meanwhile, P. distasonis effectively inhibited NF-𝜿B signal pathway and reduced the production of inflammatory cytokines, including TNF-α and IL-1β, alleviating the inflammatory response. Notably, P. distasonis treatment increased the levels of vascular density markers including cluster of differentiation 31 (CD31) and alpha-smooth muscle actin (α-SMA), ameliorating vascular damage in HAS rats. Together, these findings highlighted the important role of P. distasonis in the pathogenesis of HAS, and its mechanism was involved in the regulation of gut microbiota-gut-brain axis, which implied a novel strategy against HAS.

MiR-525-5p modulates cell proliferation, cell cycle, and apoptosis in Burkitt's lymphoma by targeting MyD88 and regulating the NF-κB signaling pathway.

MiR-525-5p functions as an oncomiRNA or tumor suppressor, and has been reported in various cancer types, including laryngeal squamous cell carcinoma, glioma, breast cancer, and cervical cancer. However, the biological functions and precise mechanisms of miR-525-5p remain unclarified in Burkitt's lymphoma (BL). This study aimed to explore the roles of miR-525-5p in BL, with the goal of ascertaining its regulatory effects on the nuclear factor-kappaB (NF-κB) signaling pathway by targeting Myeloid differentiation factor 88 (MyD88). The expression levels of miR-525-5p and MyD88 were measured by quantitative real-time PCR and immunohistochemical staining, respectively. The effects of miR-525-5p overexpression on BL cell proliferation, colony-forming, and migration were evaluated by cell counting kit-8, soft agar colony-forming, and transwell assays, while cell cycle and cell apoptosis were analyzed by flow cytometry. Possible interactions between miR-525-5p and MyD88 was examined via luciferase reporter assay. The expression of MyD88 and NF-κB signaling pathway-related proteins, including p65, p-p65, IκBa, and p-ΙκBa was determined by western blotting. BL cells overexpressing miR-525-5p were treated with phorbol 12-myristate 13-acetate (PMA), and Hoechst 33258 staining and Calcein AM/EthD-I staining were used to analyze the changes in chemotherapy sensitivity of BL cells to doxorubicin (DOX). Compared with reactive lymphoid hyperplasia, miR-525-5p was dramatically downregulated in BL tissues, while the rate of MyD88 protein positivity was significantly increased. Upregulation of miR-525-5p suppressed cell proliferation, colony-forming, and migration, induced cell cycle arrest and apoptosis, and enhanced the chemosensitivity to DOX in BL cells. MiR-525-5p targeted MyD88 to inhibit the activation of NF-κB signaling pathway. PMA treatment reactivated the NF-κB pathway and reversed apoptosis mediated by miR-525-5p overexpression. These findings revealed that miR-525-5p acts as a tumor suppressor, targeting MyD88 to modulate proliferation, cell cycle progression, and apoptosis in BL cells by regulation of NF-κB signaling pathway.

ACE2 Enhances Sensitivity to PD-L1 Blockade by Inhibiting Macrophage-Induced Immunosuppression and Angiogenesis.

Anti-PD-L1-based combination immunotherapy has become the first-line treatment for unresectable hepatocellular carcinoma (HCC). However, the objective response rate is lower than 40%, highlighting the need to identify mechanisms of tolerance to immune checkpoint inhibitors and accurate biomarkers of response. Here, we employed next-generation sequencing to analyze HCC samples from 10 patients receiving anti-PD-L1 therapy. Activation of the renin-angiotensin system was elevated in nonresponders compared with responders, and ACE2 expression was significantly downregulated in nonresponders. ACE2 deficiency promoted HCC development and anti-PD-L1 resistance, whereas ACE2 overexpression inhibited HCC progression in immune competent mice. Mass cytometry by time of flight (CyTOF) revealed that ACE2 deficient murine orthotopic tumor tissues featured elevated M2-like tumor-associated macrophages (TAMs), displayed a CCR5+PD-L1+ immunosuppressive phenotype, and exhibited high VEGFα expression. ACE2 downregulated tumor intrinsic CCL5 expression by suppressing NF-κB signaling through the ACE2/angiotensin-(1-7)/Mas receptor axis. The lower CCL5 levels led to reduced activation of the JAK-STAT3 pathway and suppressed PD-L1 and VEGFα expression in macrophages, blocking macrophage infiltration and M2-like polarization. Pharmacological targeting of CCR5 using maraviroc enhanced the tumor suppressive effect of anti-PD-L1 therapy. Together, these findings suggest that activation of the ACE2 axis overcomes the immunosuppressive microenvironment of HCC and may serve as an immunotherapeutic target and predictive biomarker of response to PD-L1 blockade.

A Necessary Role for Cyclin D2 Induction During Colon Cancer Progression Mediated by L1.

The cell adhesion molecule L1CAM (L1), mainly known for its function in brain cells, is a Wnt/β-catenin signaling target gene in colorectal cancer (CRC) cells, where it promotes invasion and liver metastasis. We interrogated which genes are expressed at increased levels in human CRC tissue and induced in CRC cell lines overexpressing L1. We found increased cyclin D2 levels in CRC tissue and LS 174T and HCT 116 human CRC cells overexpressing L1. Increased cyclin D2 in CRC cells was associated with higher proliferation rates, faster motility, tumorigenesis, and liver metastasis. The suppression of cyclin D2 expression by shRNA to cyclin D2 blocked the increase in these cellular properties of L1-expressing cells. The overexpression of cyclin D2 in the absence of L1 also conferred tumorigenic properties similar to L1 expression. The pathways involved in the elevation of cyclin D2 by L1 include NF-κB, Akt, and β-catenin signaling but not the Erk pathway. We found that in a significant percentage of human CRC tissue samples, cyclin D2 is expressed at high levels in the nuclei of cancer cells. At the same time, the adjacent normal mucosa was negative for cyclin D2 staining. The results suggest that the increased cyclin D2 expression by L1 is required to induce proliferative, motile tumor development in CRC tissue and can serve as a diagnostic marker and a target for CRC therapy.

Chitosan oligosaccharides: A potential therapeutic agent for inhibiting foam cell formation in atherosclerosis

Foam cell formation is a key hallmark in atherosclerosis and associated cardiovascular diseases (CVDs). The potential anti-atherosclerotic potential of chitosan oligosaccharides (COS) was investigated using oxLDL-treated RAW264.7 murine cells. COS treatment led to a significant inhibition of lipid accumulation, as demonstrated by Oil Red O staining, and reduced levels of total cholesterol, free cholesterol, cholesterol esters, and triglycerides in.oxLDL-treated RAW264.7 cells. COS blocked cholesterol influx through down-regulating class A1 scavenger receptors (SR-A1) and cluster of differentiation 36 (CD36) expression and stimulated cholesterol efflux through up-regulating ABC transporters ABCA-1 and ABCG-1 expressions. Additionally, COS treatment stimulated nuclear signaling pathways involving peroxisome proliferator-activated receptor-γ (PPAR-γ) and liver X receptor α (LXR-α), and also led to the phosphorylation of AMP-activated protein kinase (AMPK). COS further demonstrated anti-inflammatory effects by inhibiting the production of pro-inflammatory cytokines and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in oxLDL-treated RAW264.7 cells, through suppression of NF-κB signaling. Furthermore, COS alleviated oxidative stress induced by oxLDL by activating Nrf2 signaling and enhancing the expression of antioxidant genes, including heme oxygenase-1 (HO-1), superoxide dismutase (SOD), glutathione peroxidase (Gpx), and catalase (CAT). In conclusion, COS can be beneficial in preventing atherosclerosis and related diseases.

Acidic polysaccharides from Cistanche deserticola and their effects on the polarization of tumor-associated macrophages

Three purified polysaccharides, CDAP-1, CDAP-2, and CDAP-3, were prepared from the rhizome of Cistanche deserticola and characterized. Structural analysis revealed that CDAP-1 and CDAP-2 are highly branched RG-I-type polysaccharides with side chains, including arabinans, galactans, and/or AGs, whereas CDAP-3 is a typical HG-type polysaccharide. In vivo tests revealed that treatment with the crude polysaccharide fraction (CDCP) significantly prolonged the survival of H22 tumor-bearing mice and exhibited antitumor effects. In vitro experiments demonstrated that all three polysaccharides could polarize M2-like TAMs toward the M1 phenotype. As a major component of CDCP, CDAP-2 could act on M2 macrophages through the TLR4 receptor-mediated NF-κB signaling pathway. An in vitro cell model verified that CDAP-2 could inhibit cell proliferation by reversing the polarization of M2-like TAMs to the cytotoxic M1 phenotype. Overall, we found that CDCP showed a clear antitumor effect and that its major component, CDAP-2, could reverse the suppressive TAM phenotype in the microenvironment, providing a scientific basis for the clinical application and development of C. deserticola.

Epigenetic Mechanisms of Aluminum-Induced Neurotoxicity and Alzheimer's Disease: A Focus on Non-Coding RNAs.

Aluminum (Al) is known to induce neurotoxic effects, potentially contributing to Alzheimer's disease (AD) pathogenesis. Recent studies suggest that epigenetic modification may contribute to Al neurotoxicity, although the mechanisms are still debatable. Therefore, the objective of the present study was to summarize existing data on the involvement of epigenetic mechanisms in Al-induced neurotoxicity, especially AD-type pathology. Existing data demonstrate that Al exposure induces disruption in DNA methylation, histone modifications, and non-coding RNA expression in brains. Alterations in DNA methylation following Al exposure were shown to be mediated by changes in expression and activity of DNA methyltransferases (DNMTs) and ten-eleven translocation proteins (TETs). Al exposure was shown to reduce histone acetylation by up-regulating expression of histone deacetylases (HDACs) and impair histone methylation, ultimately contributing to down-regulation of brain-derived neurotrophic factor (BDNF) expression and activation of nuclear factor κB (NF-κB) signaling. Neurotoxic effects of Al exposure were also associated with aberrant expression of non-coding RNAs, especially microRNAs (miR). Al-induced patterns of miR expression were involved in development of AD-type pathology by increasing amyloid β (Aβ) production through up-regulation of Aβ precursor protein (APP) and β secretase (BACE1) expression (down-regulation of miR-29a/b, miR-101, miR-124, and Let-7c expression), increasing in neuroinflammation through NF-κB signaling (up-regulation of miR-9, miR-125b, miR-128, and 146a), as well as modulating other signaling pathways. Furthermore, reduced global DNA methylation, altered histone modification, and aberrant miRNA expression were associated with cognitive decline in Al-exposed subjects. However, further studies are required to evaluate the contribution of epigenetic mechanisms to Al-induced neurotoxicity and/or AD development.

Caffeic Acid Phenethyl Ester Suppresses Cytokine- and Chemotherapy-Induced Inflammation in Triple-Negative Breast Cancer via NF-κB Signalling

Background: Triple-negative breast cancer (TNBC) remains a significant clinical challenge due to its aggressive nature and lack of targeted therapies. In TNBC, inflammation contributes to tumour progression by promoting cell proliferation, survival, and migration. It may be triggered by cytokines such as TNF-α or chemotherapeutic agents such as doxorubicin (DOX). Thus, identifying agents that suppress inflammation in TNBC is of prime interest. Caffeic acid phenethyl ester (CAPE) is a naturally occurring anti-inflammatory compound that exhibits selective cytotoxicity against some cancer cells. However, its impact on cytokine or chemotherapy induced inflammation in TNBC has not yet been explored. Aim: This study aimed to investigate the effects of CAPE on TNF-α- or DOX-induced inflammation and metastatic markers in TNBC. Methods: The effects of CAPE and DOX on TNBC cell viability and migration were assessed using the MTT and wound healing assays, respectively. The effect of CAPE on the expression of pro-inflammatory cytokines, epithelial-mesenchymal transition (EMT) markers, and tumour invasion markers was evaluated using RT-qPCR. Results: CAPE inhibited TNF-α-induced proliferation and migration of TNBC cells. CAPE also suppressed TNF-α- and DOX-induced upregulation of NF-κB-regulated pro-inflammatory genes, IL-1B, IL-6, IL-8, and TNF-α, corroborating the evidence that CAPE suppresses NF-κB signalling. Additionally, CAPE suppressed EMT in TNF-α–stimulated and DOX-treated cells by downregulating vimentin and VCAM1. Furthermore, CAPE reduced the expression of the cancer invasion markers MMP2 and MMP9. Conclusions: We demonstrated the anticancer potential of CAPE and its ability to suppress cytokine and chemotherapy-induced inflammation. This study offers novel insights into the role of CAPE in suppressing inflammation and metastasis markers in TNBC, specifically in the context of TNF-α and DOX-induced NF-κB signalling. These findings underscore the urgent need to further study CAPE as a possible adjuvant for treating patients with TNBC, especially those undergoing chemotherapy.

Analysis of human neutrophils from nasal polyps by single-cell RNA sequencing reveals roles of neutrophils in chronic rhinosinusitis

BackgroundChronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 (T2) inflammation. Recent studies, including our own, suggest that neutrophils are also elevated in T2 nasal polyps (NPs) and that elevated neutrophils display an activated phenotype. However, the actual roles of neutrophils in NP pathogenesis in T2 CRSwNP are still largely unclear. ObjectiveTo reveal the roles and heterogeneity of neutrophils in NP tissue by single cell RNA-Sequencing (scRNA-Seq) analysis. MethodsWe developed a novel microwell-based scRNA-Seq assay (BD Rhapsody platform) using granulocyte enriched samples from 5 control sinus tissues (CTs), 5 NP tissues and patient matched peripheral blood (PB) samples. This approach allowed for the examination of differential expression of genes in NP neutrophils by the Benjamini-Hochberg algorithm and predicted the overall function of NP neutrophils by pathway and gene ontology (GO) enrichment analyses. ResultsAfter all QC steps, we successfully detected neutrophils. We identified 333 down-regulated and 128 up-regulated genes in NP neutrophils (1,151 cells) compared to all PB neutrophils (13,591 cells) (>1.5-fold, q<0.05), and found commonly dysregulated genes in NP neutrophils compared to both all PB and CT neutrophils (3,136 cells). Commonly down-regulated genes in NP neutrophils were associated with the innate immune system, and up-regulated genes were associated with NF-κB signaling, cytokine activity and cellular response to oxygen-containing compounds. NP neutrophils displayed 4 clusters revealing potential heterogeneity of neutrophils in NP tissue. ConclusionsElevated neutrophils in NP tissue appear to exist in several subphenotypes that may play important pathogenic roles in CRSwNP.

The Effects and Mechanisms of Chrysosplenetin in Targeting RANKL-Induced NF-κB Signaling and NFATc1 Activation to Protect Bone Density in Osteolytic Diseases.

Chrysosplenetin (CHR), an O-methylated flavonol from Chamomilla recutita and Laggera pterodonta, has previously demonstrated efficacy in enhancing osteoblast differentiation for treating postmenopausal osteoporosis. This study aims to evaluate CHR's potential to inhibit osteoclastogenesis and prevent bone deterioration in both in vitro and in vivo models. Using tartaric acid-resistant acid phosphatase staining and hydroxyapatite resorption assays, we examined the impact of CHR on RANKL-induced osteoclasts derived from mouse bone marrow monocytes. Additionally, Western blot analysis and qRT-PCR were utilized to assess the protein and gene expressions within the MAPK and NF-κB signaling pathways, as well as the NFATc1 pathway. In vivo, CHR's effects were validated using micro-CT and histomorphometry in an ovariectomized mouse model, showing significant reduction in osteoclast activity and bone loss. The study confirms CHR's inhibition of osteoclastogenesis through interference with RANKL-mediated signaling pathways, suggesting its potential as a novel therapeutic agent for osteolytic conditions related to osteoclast-osteoblast dysregulation.

Damascenone Inhibits Osteoclastogenesis by Epigenetically Modulating Nrf2-Mediated ROS Scavenge and Counteracts OVX-Induced Osteoporosis

BackgroundBone formation and resorption regulate bone homeostasis. Excessive osteoclastogenesis enhances bone resorption and causes osteoporosis. Although medicines targeting osteoclast have been developed, these drugs have several side effects. Natural compounds have advantages in safety and efficiency, making them potential candidates for osteoporosis treatment. PurposeThis study aims to elucidate the role of damascenone (Dama) in osteoclastogenesis and osteoporosis. Study design and methodsTo demonstrate the effect of Dama on osteoclast differentiation and function, we performed multiple in vitro experiments including TRAP staining, F-actin staining, bone slice resorption assay, real-time PCR, and western bolt. Further, ROS detection, network pharmacology, microscale thermophoresis assay, and ChIP assay were conducted to elucidate the underlying molecular mechanism. Finally, the in vivo effects of Dama were verified using an ovariectomy induced osteoporosis mice model. ResultsDama inhibited RANKL-induced osteoclast differentiation and bone resorptive function in vitro. The expression of osteoclast-related genes and activation of MAPKs and NF-κB signaling in osteoclast were also attenuated by Dama. Meanwhile, Dama reduced intracellular ROS level via up-regulating Nrf2 expression. Network pharmacology demonstrated that HDAC2 is the potential direct target of Dama. Dama inhibited HDAC2 function and increased H3K27ac level of Nrf2, which induced Nrf2 expression and activated ROS scavenging enzymes. Inhibiting NRF2 or activating HDAC2 attenuated the effect of Dama on osteoclastogenesis. Finally, Dama injection suppressed in vivo osteoclastogenesis and ameliorated bone loss induced by OVX. ConclusionDama attenuates osteoclastogenesis by epigenetically modulating Nrf2 expression and ROS scavenge. This study provides evidence for Dama being a potential treatment for osteoporosis.

Cedrol attenuates acute ischemic injury through inhibition of microglia-associated neuroinflammation via ERβ-NF-κB signaling pathways

Microglia-associated neuroinflammation plays essential roles in pathology of acute stroke. Cedrol, a natural compound extracted from ginger, has been shown to confer inhibitory effects on inflammation in various diseases. However, whether Cedrol suppresses neuroinflammation and protects brains from acute ischemic injury still remains unclear. In this study, we found that Cedrol inhibited microglia activation and the production of inflammatory factors in LPS-challenged microglia and the penumbra region of middle cerebral artery occlusion (MCAO) mice. We also found that Cedrol reduced the infarct size and mNSS scores and improved acute cerebral ischemia-induced behavioral outcomes, suggesting remarked neuroprotection of Cedrol. Molecular docking analysis showed that Cedrol bound to estrogen receptor β (ERβ) with moderate-strong affinity. Intriguingly, treatment with fulvestrant, an ER blocker, abolished the anti-inflammatory effects of Cedrol. Cedrol significantly reversed the LPS- and MCAO-induced increases in phosphorylation levels of IκB and NF-κB P65 in primary microglia and MCAO mice, respectively. Additionally, Cedrol was observed to rescue LPS-induced shuttling of NF-κB P65 from cytoplasm to nuclei in primary microglia, indicating inhibitory effects of Cedrol on NF-κB signaling. These results suggest microglia associated neuroinflammation may be mediated by ERβ-NF-κB signaling pathway. Together, our study reveals that Cedrol protected brain function from acute cerebral ischemia through inhibition of microglia-associated neuroinflammation via ERβ-NF-κB signaling pathways, and Cedrol may serve as an alternative option for treatment of acute stroke injury.

Extracellular Hsp90 of Candida albicans contributes to the virulence of the pathogen by activating the NF-κB signaling pathway and inducing macrophage pyroptosis

Strategies aimed at targeting fungal extracellular heat shock protein 90 (eHsp90) using vaccines and antibodies have demonstrated encouraging potential in the prevention and management of invasive fungal diseases (IFDs). However, the precise underlying mechanism by which eHsp90 contributes to the heightened virulence of Candida albicans (C. albicans) remains an enigma, awaiting further elucidation. In our current research, we have found that the 47-kDa fragment of C. albicans Hsp90 (CaHsp90), which serves as the primary antigenic determinant, is not degraded within C. albicans cells. Moreover, we have discovered that extracellular CaHsp90 (eCaHsp90) is derived from the components of lysed C. albicans cells. We also generated recombinant CaHsp90 in Escherichia coli, and found that eCaHsp90 spreads beyond the initial C. albicans colonization site, thereby enhancing the overall virulence of the organism. Our results further clarify that eCaHsp90 activates the nuclear factor kappa-B (NF-κB) signaling pathway and upregulates the expression of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3). This upregulation results in the activation of Gasdermin D (GSDMD) and subsequent macrophage pyroptosis, ultimately increasing the virulence of C. albicans. This study provides valuable insights into the mechanism by which eCaHsp90 contributes to the virulence of C. albicans, offering a pharmacological basis for antifungal strategies targeting fungal eHsp90.

Race for the surface between THP-1 macrophages and Staphylococcus aureus on various titanium implants with well-defined topography and wettability.

Gristina et al. (1987) suggested the fate of a biomaterial is decided in a “race for the surface” between pathogens and the host. To gain deeper insight into the mechanisms behind this concept, we investigated the “race for the surface” across three co-culture scenarios with THP-1 macrophages and Staphylococcus aureus (1:1 ratio), varying the order of addition: (i) simultaneous, (ii) macrophages first, and (iii) S. aureus first, on six Ti6Al4V-ELI surfaces modified with specific topographies and wettability. The outcome of the race for the surface was not influenced by these biomaterials but by the chronological introduction of macrophages and S. aureus. When macrophages and S. aureus arrived simultaneously, macrophages won the race, leading to the lowest number of viable S. aureus through rapid phagocytosis and killing. When macrophages arrived and established first, macrophages still prevailed but under greater challenge resulting from the lower bacterial killing efficiency of adherent macrophages and numerous viable intracellular bacteria, supporting the concept of the so-called immunocompromised zone around implants (upregulation of TLR-2 receptor and pro-inflammatory IL-1β). When S. aureus arrived first establishing a biofilm, bacteria won the race, leading to macrophage dysfunction and cell death (upregulation of FcγR and TLR-2 receptors, NF-κB signaling, NOX2 mediated reactive oxygen species), contributing to a persistent biofilm phenotype (upregulation of clfA, icaA, sarA, downregulation of agrA, hld, lukAB) and intracellular survival of S. aureus (lipA upregulation). The clinical implications are bacterial colonization of the implant and persistence of intracellular bacteria in periprosthetic tissues, which can lead to infection chronicity. Statement of SignificanceGristina et al. (1987) suggested the fate of a biomaterial is decided in a “race for the surface” between bacterial pathogens and host cells. There is a lack of in vitro co-culture models and knowledge on macrophage-S. aureus interactions on biomaterial surfaces, and none has evaluated the expression of virulence factors in S. aureus biofilms.We have successfully developed co-culture models and molecular panels and elucidated important cellular and molecular interactions between macrophages and S. aureus on a broad range of titanium biomaterials with well-defined surface topography and wettability. Our findings highlight the critical role of biofilm formation and the chronological order of bacteria or macrophage arrival in determining the fate of the surface.

Glycyrrhizic acid and patchouli alcohol in Huoxiang Zhengqi attenuate intestinal inflammation and barrier injury via regulating endogenous corticosterone metabolism mediated by 11β-HSD1

Ethnopharmacological relevanceUlcerative colitis (UC), a chronic inflammatory bowel disease, has become a significant public health challenge due to the limited effectiveness of available therapies. Huoxiang Zhengqi (HXZQ), a well-established traditional Chinese formula, shows potential in managing UC, as suggested by clinical and pharmacological studies. However, the active components and mechanisms responsible for its effects remain unclear. Aim of studyThis study aimed to identify the bioactive components of HXZQ responsible for its therapeutic effects on UC and to elucidate their underlying mechanisms. Materials and methodsThe effect of HXZQ against dextran sodium sulfate (DSS) -induced colitis was investigated. Ingredients in HXZQ were characterized and analyzed in colitic mice using liquid chromatography–mass spectrometry (LC-MS) and gas chromatography–mass spectrometry (GC-MS). In vitro, biological activity of compounds was assessed using lipopolysaccharide (LPS)-induced Ana-1 cells and bone marrow-derived macrophages (BMDMs), tumor necrosis factor-alpha-induced Caco-2 cells, and isolated intestinal crypts from colitic mice. These results were confirmed in vivo. The targets of the components were identified through bioinformatics analysis and validated via molecular docking, enzyme inhibition assays, and in vivo experiments. Hematoxylin and eosin (HE) staining, periodic acid-Schiff (PAS) staining, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), western blotting, and quantitative real-time polymerase chain reaction (qPCR) were employed to confirm the pharmaceutical effects. ResultsA clinical equivalent dose of HXZQ (2.5 mL/kg) effectively treated DSS-induced colitis. 113 compounds were identified in HXZQ, with 35 compounds detected in colitic mice. Glycyrrhizic acid (GA) and patchouli alcohol (PA) emerged as key contributors to the anti-colitic effects of HXZQ. Further investigation revealed that HXZQ and its active components decreased the levels of pro-inflammatory cytokines TNF-α, interleukin-1β (IL-1β), and interleukin-6 (IL-6) in colon, likely by inhibiting nuclear factor kappa-B (NF-κB) signaling pathway. This inhibition indirectly activated the intestinal farnesoid X receptor (FXR) signaling pathway, correcting bile acid imbalances caused by colitis. Additionally, these components significantly enhanced the expression of tight junction proteins ZO-1 and Occludin, as well as the adhesion protein E-cadherin, and reduced goblet cell loss, thereby repairing intestinal barrier injury. Mechanistically, GA and PA were found to inhibit 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) activity, leading to increased local active corticosterone levels in the intestine to exert anti-inflammatory effects. Notably, the inhibition of 11β-HSD1 with the selective inhibitor BVT ameliorated colitis in mice. ConclusionsHXZQ exhibits therapeutic effects on UC, primarily through GA and PA inhibiting 11β-HSD1. This suggests new natural therapy approaches for UC and positions 11β-HSD1 as a potential target for colitis treatment.

Chitosan-encapsulated Selenium Nanoparticles Alleviate CCl4 Induced Hepatotoxicity through Synergistically Modulating NF-κB and Nrf2 Signaling Pathways and Regulating Bcl-2 and Caspase-3 Expression: A Comprehensive Study with Multiple Regression Analysis

BackgroundThe delivery of selenium in a nano-form (Se-NPs) is a promising modality of treatment for various oxidative stress-induced diseases. ObjectiveThis study aims to investigate the conceivable effects of selenium nanoparticles either alone (Se-NPs) or encapsulated with chitosan (Se-CS-NPs) on toxicity induced by CCl4 in rats. MethodsEighty albino rats were divided equally into eight groups. The first group was the placebo. The second group was a positive control, while the third and the fourth groups got orally (Se-NPs 5mg/Kg) and (Se-CS-NPs 225mg/Kg) respectively. The fifth and sixth groups were protective groups in which Se-NPs or Se-CS-NPs were given simultaneously. The seventh and eighth groups were therapeutic as they received either Se-NPs or Se-CS-NPs after stopping the CCl4 injection for 4 weeks more. ResultsOur results showed that the protective and therapeutic groups showed an increase in caspase-3 gene expression with a decline in the expression of Bcl-2, Nrf2, and AFP genes. Histopathological and immunohistochemical investigations showed the role of selenium nanoparticles either alone or coated with chitosan in decreasing fibrotic marker collagen I positive reaction ConclusionSelenium nanoparticles showed an excellent effect in counteracting the toxic effect of carbon tetrachloride on liver functions, inflammation reactions, and apoptosis process. Moreover, using selenium nanoparticles has a strong role in preserving the liver architecture with its normal constituents. No additional benefit was observed when the selenium nanoparticles were encapsulated with chitosan.

Identification, functional analysis of chitin-binding proteins and the association of its single nucleotide polymorphisms with Vibrio parahaemolyticus resistance in Penaeus vannamei

Chitin-binding proteins (CBPs) play pivotal roles in numerous biological processes in arthropods, including growth, molting, reproduction, and immune defense. However, their function in the antibacterial immune defense of crustaceans remains relatively underexplored. In this study, twenty CBPs were identified and characterized in Penaeus vannamei. Expression profiling highlighted that the majority of CBPs were highly expressed in the intestine and hepatopancreas and responded to challenge by Vibrio parahaemolyticus. To explore the role of these CBPs in innate immunity, six CBPs (PvPrg4, PvKrtap16, PvPT-1a, PvPT-1b, PvExtensin and PvCP-AM1159) were selected for RNAi experiments. Silencing of only PvPrg4 and PvKrtap16 significantly decreased the cumulative mortality of V. parahaemolyticus-infected shrimp. Further studies demonstrated that inhibition of PvPrg4 and PvKrtap16 resulted in a marked upregulation of genes associated with the NF-κB and JAK-STAT signaling pathways, as well as antimicrobial peptides (AMPs), in both the intestine and hepatopancreas. These results collectively suggested that PvPrg4 and PvKrtap16 potentially promote V. parahaemolyticus invasion by negatively regulating the JAK-STAT and NF-κB pathways, thereby inhibiting the expression of AMPs. In addition, SNP analysis identified three SNPs in the exons of PvPrg4 that were significantly associated with tolerance to V. parahaemolyticus. Taken together, these findings are expected to assist in the molecular marker-assisted breeding of P. vannamei associated with anti-V. parahaemolyticus traits, as well as expand our understanding of CBP functions within the immune regulatory system of crustaceans.

Shen Gu An Capsule Inhibition of Postmenopausal Osteoporosis in Ovariectomized Mice Using Network Pharmacology-Based Mechanism Prediction and Pharmacological Validation

Background Postmenopausal osteoporosis (PMOP) is characterized by low bone mass and increased bone fragility in postmenopausal women. Shen Gu An capsule (SGA) has been clinically used to treat bone diseases, especially PMOP with kidney Yang deficiency. Objectives We aimed to study the effect of SGA on the treatment of PMOP. Methodology The key candidate targets and pathways of SGA for treating PMOP were predicted by Network pharmacology analysis. Then, in vivo validation using bilaterally ovariectomized C57BL/6 mice was performed, and the bone quality was analyzed by Micro-CT and histological analysis. Results In this study, we obtained 113 active compounds and 82 targets via the database of Traditional Chinese Medicine Systems Pharmacology. Subsequently, compound-target and protein−protein interaction networks were constructed. Then GO and KEGG analysis revealed that NF-κB signaling pathway might be the underlying mechanism as its well-known function in osteoclastogenesis. Furthermore, the in vivo experiments using ovariectomized mice demonstrated that SGA could decrease the number of osteoclasts and preserve bone mass through inhibiting the NF-κB signaling pathway. Conclusions SGA could prevent postmenopausal osteoporosis in ovariectomized mice through inhibiting NF-κB signaling pathway. The finding of this study provides more evidence for the clinical application of SGA to treat osteoporosis.

Targeting of ubiquitination and degradation of KLF15 by E3 ubiquitin ligase KBTBD7 regulates LPS-induced septic brain injury in microglia

Septic brain injury is a serious disease of the central nervous system that involves inflammation. Kelch repeat and BTB domain containing 7 (KBTBD7), an E3 ubiquitin ligase, is demonstrated to facilitate the pathological changes of various diseases, but its impact on septic brain injury is unclear. In this study, a rat model of septic brain injury was induced by cecal ligation and puncture (CLP). The neurobehavioral score and survival rate of CLP group were worse than those of sham group. In addition, CLP was found to evoke microglia activation, increase inflammation, induce the activation of NLRP3 inflammasome and NF-κB signaling pathway, and upregulate KBTBD7 expression. Immunofluorescence revealed strong positive KBTBD7 staining in CLP rat microglia. Furthermore, primary microglia were exposed to lipopolysaccharide (LPS) to explore the role and mechanism of KBTBD7. The results showed that KBTBD7 expression was increased in LPS-treated microglia. Knockdown of KBTBD7 markedly inhibited LPS-induced proinflammatory cytokine release, as well as the activation of NLRP3 inflammasome and NF-κB signaling pathway. The downstream molecular mechanism of KBTBD7 was then mined. Notably, co-immunoprecipitation (co-IP) results confirmed that KBTBD7 was a novel interacting protein of KLF transcription factor 15 (KLF15) and acted as an E3 ubiquitin ligase that catalyzed the ubiquitination degradation of KLF15 through the ubiquitin-proteasome system. Moreover, recovery experiment data suggested that KLF15 knockdown abolished the anti-inflammatory role of KBTBD7 knockdown in microglia, implying that KLF15 influenced the function of KBTBD7. Taken together, our results reveal a novel KBTBD7-KLF15 signal transduction pathway involved in septic brain injury and provide a potential therapeutic strategy for its treatment.