Activation Of Signaling Pathway Research Articles

Prolonged Survival of Neutrophils Induced by Tumor-Derived G-CSF/GM-CSF Promotes Immunosuppression and Progression in Laryngeal Squamous Cell Carcinoma.

Tumor-associated neutrophils (TANs) play a crucial role in tumor progression and exhibit prolonged survival. However, the mechanism underlying their extended lifespan and significance in laryngeal squamous cell carcinoma (LSCC) remains unclear. Herein, it is observed that apoptosis of TANs is significantly delayed owing to induction by tumor-derived G-CSF and GM-CSF through the activation of the PI3K-AKT signaling pathway, upregulation of anti-apoptotic Mcl-1 expression, and downregulation of activated Caspase-3 levels. It is found that prolonged survival of TANs leads to the accumulation of aged CXCR4+ neutrophils that exhibit potent immunosuppressive properties and are associated with poor patient prognosis. Furthermore, extended survival promotes the enhanced immunosuppressive function of CD8+ T cells by TANs, thereby facilitating the in vitro and in vivo progression and growth of human LSCC tumors. Importantly, this effect could be reversed by blocking G-CSF and GM-CSF stimulation of neutrophils. These findings elucidate the pivotal role of pathologically prolonged neutrophil survival in impairing CD8+ T cell immunity and suggest targeting it as a potential therapeutic strategy for tumors.

Heparin-binding EGF-like growth factor: mechanisms of biological activity and potential therapeutic applications

The diphtheria toxin receptor on sensitive mammalian cells is known as the membrane anchored precursor of heparin-binding EGF-like growth factor (HB-EGF). When the precursor is cleaved by metalloproteinases, a soluble form (sHB-EGF) is formed that can bind to the EGF receptors, resulting in activation of signaling pathways that regulate cell proliferation, differentiation, migration, and inhibition of apoptosis. The ability of HB-EGF to cause both positive and negative consequences for organism underscores the complexity of its biological functions and the need for a nuanced understanding of its role in health and disease. In this review the data on the HB-EGF structure, biological activity, involvement in the mechanism of diphtheria toxin action, wound healing, tumor progression as well as the methods of HB-EGF delivery are summarized. Keywords: cell proliferation, diphtheria toxin, EGF receptor, heparin-binding EGF-like growth factor, signal transduction, wound healing

Clopidogrel ameliorates high-fat diet-induced hepatic steatosis in mice through activation of the AMPK signaling pathway and beyond.

Metabolic dysfunction-associated steatotic liver disease (MASLD) frequently confers an increased risk of vascular thrombosis; however, the marketed antiplatelet drugs are investigated for the prevention and treatment of MASLD in patients with these coexisting diseases. To determine whether clopidogrel could ameliorate high-fat diet (HFD)-induced hepatic steatosis in mice and how it works, mice were fed on normal diet or HFD alone or in combination with or without clopidogrel for 14weeks, and primary mouse hepatocytes were treated with palmitate/oleate alone or in combination with the compounds examined for 24h. Body weight, liver weight, insulin resistance, triglyceride and total cholesterol content in serum and liver, histological morphology, transcriptomic analysis of mouse liver, and multiple key MASLD-associated genes and proteins were measured, respectively. Clopidogrel mitigated HFD-induced hepatic steatosis (as measured with oil red O staining and triglyceride kit assay) and reduced elevations in serum aminotransferases, liver weight, and the ratio of liver to body weight. Clopidogrel downregulated the expression of multiple critical lipogenic (Acaca/Acacb, Fasn, Scd1, Elovl6, Mogat1, Pparg, Cd36, and Fabp4), profibrotic (Col1a1, Col1a2, Col3a1, Col4a1, Acta2, and Mmp2), and proinflammatory (Ccl2, Cxcl2, Cxcl10, Il1a, Tlr4, and Nlrp3) genes, and enhanced phosphorylation of AMPK and ACC. However, compound C (an AMPK inhibitor) reversed enhanced phosphorylation of AMPK and ACC in clopidogrel-treated primary mouse hepatocytes and alleviated accumulation of intracellular lipids. We concluded that clopidogrel may prevent and/or reverse HFD-induced hepatic steatosis in mice, suggesting that clopidogrel could be repurposed to fight fatty liver in patients.

Identification of HSPG2 as a bladder pro-tumor protein through NID1/AKT signaling

PurposeHeparan sulfate proteoglycans (HSPGs) are complex molecules found on the cell membrane and within the extracellular matrix, increasingly recognized for their role in tumor progression. This study aimed to investigate the involvement of Heparan sulfate proteoglycan 2 (HSPG2) in the progression of bladder cancer.MethodsWe identified HSPG2 as a promoter of bladder tumor progression using single-cell RNA sequencing and transcriptome analysis of sequencing data from seven patient samples obtained from the Gene Expression Omnibus (GEO) database (GSE135337). Transcript profiles of 28 normal tissues and 407 bladder tumor tissues were analyzed for HSPG2 expression and survival outcomes using the Sanger tools and cBioPortal databases. HSPG2-overexpressing T24 and Biu-87 cell lines were generated, and cell proliferation and migration were assessed using CCK-8 and Transwell assays. Western blotting and immunostaining were performed to evaluate the activation of Nidogen-1 (NID1)/protein kinase B (AKT) signaling. Mouse models with patient-derived tumor organoids (HSPG2high and HSPG2low) were established to assess anticancer effects.ResultsOur results demonstrated a marked upregulation of HSPG2 in malignant bladder tumors, which correlated significantly with poor patient prognosis. HSPG2 overexpression consistently enhanced bladder tumor cell proliferation and conferred chemotherapy resistance, as shown in both in vitro and in vivo experiments. Mechanistically, HSPG2 upregulated NID1 expression, leading to the activation of the AKT pro-survival signaling pathway and promoting sustained tumor growth in bladder cancer.ConclusionThis study highlights the critical pro-tumor role of HSPG2/NID1/AKT signaling in bladder cancer and suggests its potential as a therapeutic target in clinical treatment.

Benzoylmesaconine mitigates NLRP3 inflammasome-related diseases by reducing intracellular K+ efflux and disrupting NLRP3 inflammasome assembly

BackgroundBenzoylmesaconine (BMA), a major alkaloid derived from the traditional Chinese medicine Aconitum carmichaeli Debx, exhibits potent anti-inflammatory properties. However, the precise mechanism underlying its action remains unclear. PurposeThis study aimed to investigate the inhibitory mechanism of BMA on the NLRP3 inflammasome and assess its therapeutic efficacy in NLRP3-related metabolic diseases. MethodsA classic NLRP3 inflammasome-activated bone marrow-derived macrophage (BMDM) model was established to evaluate BMA's effects on NLRP3 upstream and downstream protein expression, as well as pyroptosis. Two distinct animal disease models, MSU-induced gouty arthritis and DSS-induced colitis, were utilized to validate BMA's anti-inflammatory activity in vivo. ResultsIn vitro findings revealed that BMA can suppress NLRP3 inflammasome activation by inhibiting interleukin-1β (IL-1β) secretion and GSDMD-N protein expression. This mechanism involved blocking intracellular K+ efflux and interfering with the formation of NLRP3 inflammasomes. In vivo studies demonstrated that BMA significantly alleviated inflammatory symptoms in MSU-induced acute gout and DSS-induced colitis models. ConclusionThese findings suggest that BMA effectively inhibits the activation of the NLRP3 signaling pathway through dual mechanisms: reducing intracellular K+ efflux and disrupting NLRP3 inflammasome assembly. This multifaceted action highlights the therapeutic potential of BMA for NLRP3-related diseases.

SKI-606, a Src inhibitor, ameliorates benzene-induced hematotoxicity via blocking ROS/Src kinase-mediated p38 and Akt signaling pathways

Exposure to benzene causes acute myelosuppression and other hematologic disorders. However, the detailed mechanism by which benzene exerts its severe hematotoxicity and potential treatments still require further deciphering and exploration. Herein, we found that hydroquinone (HQ), a main benzene metabolite, significantly increased intracellular reactive oxygen species (ROS) formation and subsequently caused damage to DNA, leading to impaired colony formation capacity and induction of apoptosis in human hematopoietic stem/progenitor cells (HSPCs) in vitro. The effects were mediated by activation of Src kinase, which subsequently activated the p38 signaling pathway while inhibiting the Akt signaling pathway. The mechanism was further verified by pre-treatment with a Src kinase inhibitor SKI-606, which effectively reversed the dampened self-renewal capacity and increased apoptosis of HSPCs induced by HQ in vitro. Furthermore, administration of SKI-606 partially reversed benzene-induced hematotoxicity and prolonged the survival time in benzene-poisoned mice. Taken together, these findings highlight that HQ-induced hematotoxicity in HSPCs is attributed to the Src kinase-mediated activation of p38 signaling pathway and repression of Akt signaling pathway. Notably, SKI-606 as a tyrosine kinase inhibitor may be a promising and potential agent for alleviating benzene-induced hematotoxicity.

Melatonin modulates the Notch1 signaling pathway and Sirt3 in the hippocampus of hypoxic-ischemic neonatal rats

The Notch1 signaling pathway plays a crucial role in the development of the central nervous system, governing pivotal functional activities in the brain, such as neurogenesis. Sirt3 is instrumental in managing mitochondrial homeostasis and is essential to cell survival. Dysregulation of these signaling pathways is implicated in the pathogenesis of a wide range of diseases, including neurodegenerative disorders such as stroke. We have previously shown that melatonin significantly improved the perinatal brain damage caused by hypoxia-ischemia (HI) through the activation of several protective mechanisms such as restoring mitochondria status and increasing the hippocampal cell proliferation. This study assessed whether melatonin affects the Notch1 signaling pathway and Sirt3 after neonatal HI. Results show that HI significantly increased Notch1 expression both in hippocampal neurons and glial cells as well as the expression of the key proteins of the pathway NICD, HES1, and c-Myc. Melatonin significantly prevented the Notch1 signaling pathway activation induced by HI, maintaining NICD and HES1 expression to control levels. In the same neurons, melatonin also prevents the Sirt3 depletion caused by HI. In summary, this study provides new insights into the effects of melatonin on the Notch1 signaling pathway and Sirt3 in in vivo neonatal brain ischemia. We suggest that the rapid modulation of the Notch1 signaling pathway and Sirt3 induced by melatonin may support neuronal survival during ischemia.

Quorum Sensing Molecule Autoinducer-2 Promotes Macrophage Classical Polarization and Exacerbates Periodontal Inflammation Via Nf-Κb Signalling.

The role of quorum sensing signaling in the immunoinflammatory response during the development of periodontitis is not yet known. This study aimed to explore the effect of Autoinducer-2, a quorum sensing signaling molecule, on macrophage phenotypic remodeling in the immune microenvironment of periodontitis, to further elucidate its mechanism and to discover inhibitors against periodontitis. Bioluminescence experiments and periodontitis model were used to demonstrate the association between periodontitis progression with AI-2. Next, AI-2 challenged macrophage was introduced to transcriptomic sequence and the immune profile was characterized in combination with flow cytometry, qPCR, and immunofluorescence. Activation of NF-κB signalling by AI-2 was confirmed by fluorescence co-localization and immunoblotting. Finally, morphological methods such as Micro-CT and HE, TRAP staining and immunological methods such as immunohistochemistry/fluorescence staining were used to assess the mechanisms by which AI-2 regulates periodontitis progression. AI-2 level was positively correlated with the progression of periodontitis stages and was significantly higher in periodontitis stage III and IV patients. AI-2 promotes macrophage classical polarization and facilitates the secretion of inflammatory factors in vitro, which is dependent on the activation of the NF-κB signaling pathway. AI-2 promotes alveolar bone resorption, but D-ribose acts as a quorum sensing inhibitor to alleviate macrophage classical polarization and attenuates alveolar bone resorption and inflammatory responses in periodontitis mice. Our study demonstrates that AI-2 promoted classical polarization of macrophage and exacerbated periodontal inflammation which could be reversed by D-ribose.

Modification of xylan in secondary walls alters cell wall biosynthesis and wood formation programs and improves saccharification.

Wood of broad-leaf tree species is a valued source of renewable biomass for biorefinery and a target for genetic improvement efforts to reduce its recalcitrance. Glucuronoxylan (GX) plays a key role in recalcitrance through its interactions with cellulose and lignin. To reduce recalcitrance, we modified wood GX by expressing GH10 and GH11 endoxylanases from Aspergillus nidulans in hybrid aspen (Populus tremula L. × tremuloides Michx.) and targeting the enzymes to cell wall. The xylanases reduced tree height, modified cambial activity by increasing phloem and reducing xylem production, and reduced secondary wall deposition. Xylan molecular weight was decreased, and the spacing between acetyl and MeGlcA side chains was reduced in transgenic lines. The transgenic trees produced hypolignified xylem having thin secondary walls and deformed vessels. Glucose yields of enzymatic saccharification without pretreatment almost doubled indicating decreased recalcitrance. The transcriptomics, hormonomics and metabolomics data provided evidence for activation of cytokinin and ethylene signalling pathways, decrease in ABA levels, transcriptional suppression of lignification and a subset of secondary wall biosynthetic program, including xylan glucuronidation and acetylation machinery. Several candidate genes for perception of impairment in xylan integrity were detected. These candidates could provide a new target for uncoupling negative growth effects from reduced recalcitrance. In conclusion, our study supports the hypothesis that xylan modification generates intrinsic signals and evokes novel pathways regulating tree growth and secondary wall biosynthesis.

Mode of action exploration for prostate epithelial cell injury caused by bisphenol A

Bisphenol A (BPA) is a typical food chemical contaminant with various detrimental effects, especially on reproductive system. Male prostate damage is also one of its major adverse health effects, of which mode of action (MOA) remains unclear. This study aims to explore the MOA for prostate toxicity of BPA using human normal prostate epithelial cell RWPE-1 for 28-day human-relevant-level exposure. A physiological based pharmacokinetic model was used to determine the concentration of BPA based on the actual oral exposure in China. The possible key events were identified by high-throughput transcriptome sequencing and validated by qPCR, Western blot and cell cycle assay, and the benchmark concentration analysis were conducted. The enriched KEGG pathways include the endocytosis, cell cycle, cellular senescence, MAPK and TNF signaling pathways. With increasing BPA concentrations, the increased mRNA and/or protein expressions of MAPKAPK2, c-JUN and c-fos in the MAPK signaling pathway, the increased mRNA expressions of CCND1 and CDKN1A, the decreased mRNA expression of CDC25C, the increased proportion of G0/G1 phase and S phase, as well as the decreased proportion of G2/M phase, were observed. The lowest value of benchmark concentration lower confidence limit (BMCL) was retrieved from G2/M phase ratio, with 110.580 and 175.862 nM for BMCL5 and BMCL10, respectively, much higher than the male gonad maximum concentration of 0.019 nM of BPA at the current exposure level of adult Chinese males. In conclusion, the MOA of BPA induced male prostatic toxicity at human-relevant levels may include: key event (KE)1-MAPK signaling pathway activation, KE2-disorder of cell cycle regulatory gene expression (increased expression of CCND1 and CDKN1A, decreased expression of CDC25C), and KE3-disturbance of cell cycle (increased proportion of G0/G1 and S phases, decreased proportion of G2/M phases). However, more studies are needed to validate and complete the MOA.

Dietary Tributyrin Improves Growth Performance, Meat Quality, Muscle Oxidative Status, and Gut Microbiota in Taihe Silky Fowls under Cyclic Heat Stress.

Heat stress adversely affects poultry production and meat quality, leading to economic losses. This study aimed to investigate the effects of adding tributyrin on growth performance, meat quality, muscle oxidative status, and gut microbiota of Taihe silky fowls under cyclic heat stress (CHS) conditions. In this study, 120-day-old Taihe silky fowls (male) were randomly divided into six dietary treatments. These treatments included a normal control treatment (NC, fed a basal diet), a heat stress control treatment (HS, fed a basal diet), and HS control treatments supplemented with 0.04%, 0.08%, 0.16%, and 0.32% tributyrin, respectively. The NC treatment group was kept at 24 ± 1 °C, while the HS treatment birds were exposed to 34 ± 1 °C for 8 h/d for 4 weeks. Results showed that CHS decreased growth performance and compromised the meat quality of broilers (p < 0.05). However, tributyrin supplementation improved ADG and FCR in broilers exposed to CHS (p < 0.05). Additionally, tributyrin supplementation resulted in increased shear force value and GSH-Px activity, as well as a decrease in drip loss, ether extract content, and MDA content of the breast muscle in broilers under CHS (p < 0.05). Furthermore, tributyrin supplementation up-regulated the mRNA expressions of Nrf2, NQO1, HO-1, SOD, and GSH-Px of the breast muscle in broilers exposed to CHS (p < 0.05). Based on these positive effects, the study delved deeper to investigate the impact of 0.16% tributyrin supplementation (HS + 0.16%T) on the cecum microbiota. The HS + 0.16%T treatment showed an increase in the relative abundance of Rikenellaceae_RC9_gut_group (p < 0.05) and a trend towards an increase in Lactobacillus (p = 0.096) compared to the HS treatment. The results indicate that supplementation successfully improved the growth performance and meat quality of Taihe silky fowls. Furthermore, tributyrin supplementation, particularly at levels of 0.16%, improved meat quality by enhancing muscle antioxidant capacity, which is believed to be associated with activation of the Nrf2 signaling pathway.

SUMOylation regulates the aggressiveness of breast cancer-associated fibroblasts.

Cancer-associated fibroblasts (CAFs) are the most abundant stromal cellular component in the tumor microenvironment (TME). CAFs contribute to tumorigenesis and have been proposed as targets for anticancer therapies. Similarly, dysregulation of SUMO machinery components can disrupt the balance of SUMOylation, contributing to tumorigenesis and drug resistance in various cancers, including breast cancer. We explored the role of SUMOylation in breast CAFs and evaluated its potential as a therapeutic strategy in breast cancer. We used pharmacological and genetic approaches to analyse the functional crosstalk between breast tumor cells and CAFs. We treated breast CAFs with the SUMO1 inhibitor ginkgolic acid (GA) at two different concentrations and conditioned media was used to analyse the proliferation, migration, and invasion of breast cancer cells from different molecular subtypes. Additionally, we performed quantitative proteomics (SILAC) to study the differential signalling pathways expressed in CAFs treated with low or high concentrations of GA. We confirmed these results both in vitro and in vivo. Moreover, we used samples from metastatic breast cancer patients to evaluate the use of GA as a therapeutic strategy. Inhibition of SUMOylation with ginkgolic acid (GA) induces death in breast cancer cells but does not affect the viability of CAFs, indicating that CAFs are resistant to this therapy. While CAF viability is unaffected, CAF-conditioned media (CM) is altered by GA, impacting tumor cell behaviour in different ways depending on the overall degree to which SUMO1-SUMOylated proteins are dysregulated. Breast cancer cell lines exhibited a concentration-dependent response to conditioned media (CM) from CAFs. At a low concentration of GA (10µM), there was an increase in proliferation, migration and invasion of breast cancer cells. However, at a higher concentration of GA (30µM), these processes were inhibited. Similarly, analysis of tumor development revealed that at 10µM of GA, the tumors were heavier and there was a greater degree of metastasis compared to the tumors treated with the higher concentration of GA (30µM). Moreover, some of these effects could be explained by an alteration in the activity of the GTPase Rac1 and the activation of the AKT signalling pathway. The results obtained using SILAC suggest that different concentrations of GA affected cellular processes differentially, possibly influencing the secretome of CAFs. Treatment of metastatic breast cancer with GA demonstrated the use of SUMOylation inhibition as an alternative therapeutic strategy. The study highlights the importance of SUMOylation in the tumor microenvironment, specifically in cancer-associated fibroblasts (CAFs). Targeting SUMOylation in CAFs affects their signalling pathways and secretome in a concentration-dependent manner, regulating the protumorigenic properties of CAFs.

A Study of JUN’s Promoter Region and Its Regulators in Chickens

Background: The Jun proto-oncogene (JUN), also referred to as C-JUN, is an integral component of the JNK signaling pathway, which is crucial for the formation and differentiation of spermatogonial stem cells (SSCs). Investigations into the transcriptional regulation of chicken JUN can offer a molecular foundation for elucidating its mechanistic role in SSCs. Methods: In this study, we successfully cloned a 2000 bp upstream sequence of the JUN transcription start site and constructed a series of pGL3 recombinant vectors containing JUN promoters of varying lengths. Results: We verified the promoter activity of the 2000 bp upstream sequence by assessing the fluorescence intensity of DF-1 and identified the promoter activities of different regions via dual-luciferase assays. The transcription of JUN and its promoter region spanning −700 to 0 bp was modulated by an activator of the JNK signaling pathway. Bioinformatics analysis revealed that this −700 to 0 bp region was highly conserved among avian species and predicted the presence of binding sites for Wilms tumor 1 (WT1) and CCAAT/enhancer binding protein alpha (CEBPA). The JNK signaling pathway activator was found to upregulate the expression of these transcription factors in DF-1 cells. Through the deletion of binding sites and the overexpression of WT1 and CEBPA, we demonstrated that WT1 inhibited the transcription of JUN, while CEBPA promoted it. Conclusions: In conclusion, the −700 to 0 bp region is the key region of the JUN promoter, with WT1 inhibiting JUN transcription. The results of the study not only provide ideas for exploring the regulatory mechanism of JUN in chicken SSCs, but also lay an important foundation for the study of avian SSCs.

Ouabain Ameliorates Alzheimer’s Disease-Associated Neuropathology and Cognitive Impairment in FAD4T Mice

Background: Alzheimer’s disease (AD) is a common clinical neurodegenerative disorder, primarily characterized by progressive cognitive decline and behavioral abnormalities. The hallmark pathological changes of AD include widespread neuronal degeneration, plaques formed by the deposition of amyloid β-protein (Aβ), and neurofibrillary tangles (NFTs). With the acceleration of global aging, the incidence of AD is rising year by year, making it a major global public health concern. Due to the complex pathology of AD, finding effective interventions has become a key focus of research. Ouabain (OUA), a cardiac glycoside, is well-known for its efficacy in treating heart disease. Recent studies have also indicated its potential in AD therapy, although its exact mechanism of action remains unclear. Methods: This study integrates bioinformatics, multi-omics technologies, and in vivo and in vitro experiments to investigate the effects of OUA on the pathophysiological changes of AD and its underlying molecular mechanisms. Results: This study analyzed the expression of the triggering receptor expressed on myeloid cells 2 (TREM2) across different stages of AD using bioinformatics. Serum samples from patients were used to validate soluble TREM2 (sTREM2) levels. Using an Aβ1-42-induced microglial cell model, we confirmed that OUA enhances the PI3K/AKT signaling pathway activation by upregulating TREM2, which reduces neuroinflammation and promotes the transition of microglia from an M1 proinflammatory state to an M2 anti-inflammatory state. To evaluate the in vivo effects of OUA, we assessed the learning and memory capacity of FAD4T transgenic mice using the Morris water maze and contextual fear conditioning tests. We used real-time quantitative PCR, immunohistochemistry, and Western blotting to measure the expression of inflammation-associated cytokines and to assess microglia polarization. OUA enhances cognitive function in FAD4T mice and has been confirmed to modulate microglial M1/M2 phenotypes both in vitro and in vivo. Furthermore, through bioinformatics analysis, molecular docking, and experimental validation, TREM2 was identified as a potential target for OUA. It regulates PI3K/Akt signaling pathway activation, playing a crucial role in OUA-mediated M2 microglial polarization and its anti-inflammatory effects in models involving Aβ1-42-stimulated BV-2 cells and FAD4T mice. Conclusions: These findings indicate that OUA exerts anti-neuroinflammatory effects by regulating microglial polarization, reducing the production of inflammatory mediators, and activating the PI3K/Akt signaling pathway. Given its natural origin and dual effects on microglial polarization and neuroinflammation, OUA emerges as a promising therapeutic candidate for neuroinflammatory diseases such as AD.

N-acetylcysteine regulates NF-κB signaling pathway alleviates the pulmonary toxicity induced by indium-tin oxide nanoparticles in rats

Objective: The current study aimed to evaluate the possible protective effects of N-acetylcysteine (NAC) against Indum-tin oxide (ITO) nanoparticle (Nano-ITO) -induced pulmonary alveolar proteinosis (PAP) in rats, especially via modulation of nuclear factor kappa B (NF-κB) signaling. Methods: In October 2019, 50 adult male Sprague-Dawley rats were randomly allocated into five groups (10 rats each) as follows: blank control group, saline control group, NAC control group (200 mg/kg), Nano-ITO group (receiving a repeated intratracheal dose of 6 mg/kg Nano-ITO) and NAC intervention group (pre-treated intraperitoneally with 200 mg/kg NAC 1.5 h before the administration of an intratracheal dose of 6 mg/kg Nano-ITO). The rats were exposed twice a week for 12 weeks. Rats were then euthanized under anesthesia, and their lungs were removed for histopathological and immunohistochemical analysis. The comparison of indicators reflecting oxidative stress and pulmonary inflammation among groups was conducted using one-way analysis of variance (ANOVA) and Bonferroni's test. The effect of NAC on Nano-ITO induced NF-κB signaling pathway in rats was analyzed. Results: Histopathological examination of Nano-ITO exposed rats revealed diffuse alveolar damage, including PAP, cholesterol crystals, alveolar fibrosis, pulmonary fibrosis, and alveolar emphysema. Immunohistochemical results of Nano-ITO exposed rats showed strong positive for nuclear factor κB p65 (NF-κB p65) and nuclear factor Kappa B inhibitory factor kinase (IKK-β) and weak positive for nuclear factor κB inhibitory protein α (IκB-α) in the nuclei of bronchiolar and alveolar epithelial cells. Compared with blank control group, saline control group and NAC control group, the level of total protein (TP) in bronchoalveolar lavage fluid of rats in Nano-ITO group was significantly increased (P<0.05), and the activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD), malondialdehyde (MDA) content and total antioxidant capacity (T-AOC) were significantly increased (P<0.05), the levels of proinflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) were significantly increased (P<0.05), and the levels of NF-κB p65, IKK-β, inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS) in lung tissue were significantly increased (P<0.05). Compared with Nano-ITO group, the levels of TP, T-AOC, MDA and TNF-α in bronchoalveolar lavage fluid of rats in NAC intervention group were significantly decreased (P<0.05), and the levels of NF-κB p65 and ROS in lung tissue were significantly decreased (P<0.05). Western blot results showed that compared with the control groups, the protein expressions of NF-κB p65 and IKK-β in the lung tissue of Nano-ITO group were increased, while the protein expression of IκB-α was decreased (P<0.05). Compared with Nano-ITO group, the protein expressions of NF-κB p65 and IKK-β in lung tissue of rats in NAC intervention group were decreased, while the protein expression of IκB-α was increased (P<0.05) . Conclusion: The study demonstrated that Nano-ITO might induce pulmonary toxicity through the activation of NF-κB signaling pathway, and NAC could antagonize the pulmonary toxicity of Nano-ITO by inhibiting the NF-κB signaling pathway.

Falcarindiol improves functional recovery and alleviates neuroinflammation after spinal cord injury by inhibiting STAT/MAPK signaling pathways

Spinal cord injury (SCI) is a devastating trauma in the central nervous system (CNS), leading to motor and sensory impairment. Neuroinflammation is one of the critical contributors to the progression of secondary injury. Falcarindiol has been reported to efficaciously mitigate lipopolysaccharide (LPS)-mediated inflammation in RAW 264.7 cells. The role of falcarindiol in SCI recovery remains unclear. In this present study, traumatic SCI mice models and LPS-stimulated murine microglia cell line (BV2 cells) were performed to explore the pharmacological effects and the underlying mechanisms of falcarindiol in improving SCI repair with detection of motor function recovery, morphological changes, numbers of survival neurons and protein expression levels of inflammation or apoptosis-related proteins. Our study found that falcarindiol intervention could promote motor function recovery and reduce spinal cord tissue damage in mice following SCI. Mechanistically, falcarindiol intervention suppressed apoptosis-driven neuronal cell death and mitigated inflammatory reactions following SCI. Additionally, falcarindiol inhibited the activation of signal transducer and activator of transcription (STAT) and mitogen-activated protein kinases (MAPK) signaling pathways in vivo and in vitro. This suppression of STAT and MAPK activation by falcarindiol was reversed by STAT3 agonist Colivelin TFA and MAPK agonist C16-PAF in BV2 cells, respectively. Moreover, the study further demonstrated that the anti-inflammation role of falcarindiol was obstructed by Colivelin TFA but not by C16-PAF in LPS-stimulated BV2 cells, suggesting that falcarindiol may efficaciously ameliorate neuroinflammation through inhibiting the activation of STAT signaling pathway following SCI. Collectively, our study indicates that falcarindiol may be a novel drug candidate for the treatment and management of SCI.

Isoechinulin B, a natural product from Antarctic fungus, attenuates acute liver injury by inhibiting excessive cell adhesion

Abnormal cell adhesion between leukocytes and endothelial cells is closely associated with the development of numerous inflammation-related diseases, with adhesion molecules playing a crucial role. The disruption of cell adhesion directly or indirectly inhibits excessive cell adhesion and thus produces a therapeutic effect. However, there are only a few clinically available antagonists of cell adhesion. One of the biggest challenges is the development of novel and efficient cell adhesion inhibitors. Recently, the anti-inflammatory pharmacological activity of natural products of microbial origin has also received increasing attention. Here, we obtained a potential cell adhesion inhibitor isoechinulin B, an indole diketopiperazine derivative, from the Antarctic fungus Aspergillus sp. CPCC 401072, which is active against cell adhesion. Isoechinulin B decreased the expression of vascular endothelial adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) by inhibiting the activation of the NF-κB signaling pathway, thereby inhibiting cell adhesion between leukocytes and endothelial cells to reduce macrophage infiltration in the liver and significantly attenuate lipopolysaccharide-induced acute liver injury in mice. ConclusionIsoechinulin B is a novel cell adhesion inhibitor derived from fungi found in extreme environments.

Apelin regulates mitochondrial dynamics by inhibiting Mst1-JNK-Drp1 signaling pathway to reduce neuronal apoptosis after spinal cord injury

In the secondary injury stage of spinal cord injury, mitochondrial dysfunction leads to decreased ATP production, increased ROS production, and activation of the mitochondria-mediated apoptosis signaling pathway. This ultimately intensifies neuronal death and promotes the progression of the injury. Apelin, a peptide produced by the APLN gene, has demonstrated promise in the treatment of spinal cord injury. The aim of this study was to investigate how Apelin protects neurons after spinal cord injury by influencing the mitochondrial dynamics. The results showed that Apelin has the ability to reduce mitochondrial fission, enhance the mitochondrial membrane potential, improve antioxidant capacity, facilitate the clearance of excess ROS, and ultimately decrease apoptosis in PC12 cells. Moreover, Apelin is overexpressed in neurons in the damaged part of the spinal cord, contributing to reduce mitochondrial fission, improve antioxidant capacity, increase ATP production, decrease apoptosis, promote spinal cord morphological repair, maintain the number of nissl bodies, and enhance signal transduction in the descending spinal cord pathway. Apelin exerts its protective effect by inhibiting the Mst1-JNK-Drp1 signaling pathway. In summary, our study further improved the effect of Apelin in the treatment of spinal cord injury, revealed the mechanism of Apelin in protecting damaged neurons after spinal cord injury by maintaining mitochondrial homeostasis, and provided a new therapeutic mechanism for Apelin in spinal cord injury.

Rosmarinic Acid Attenuates Salmonella enteritidis-Induced Inflammation via Regulating TLR9/NF-κB Signaling Pathway and Intestinal Microbiota.

Salmonella enteritidis (SE) infection disrupts the homeostasis of the intestinal microbiota, causing an intestinal inflammatory response and posing a great threat to human and animal health. The unreasonable use of antibiotics has led to an increase in the prevalence of drug-resistant SE, increasing the difficulty of controlling SE. Therefore, new drug strategies and research are urgently needed to control SE. Rosmarinic acid (RA) is a natural phenolic acid with various pharmacological activities, including antioxidant, anti-inflammatory and antibacterial properties. However, the protective effects and mechanism of RA on intestinal inflammation and the gut microbial disorders caused by SE have not been fully elucidated. In this study, RAW264.7 cells, MCECs and BALB/c mice were challenged with SE to assess the protective effects and mechanisms of RA. The results showed that RA enhanced the phagocytic ability of RAW264.7 cells, reduced the invasion and adhesion ability of SE in MCECs, and inhibited SE-induced inflammation in cells. Moreover, RA inhibited the activation of the NF-κB signaling pathway by upregulating TLR9 expression. Importantly, we found that RA provided protection against SE and increased the diversity and abundance of the intestinal microbiota in mice. Compared with infection control, RA significantly increased the abundance of Firmicutes and Acidibacteria and decreased the abundance of Proteobacteria, Epsilonbacteraeota and Bacteroidota. However, RA failed to alleviate SE-induced inflammation and lost its regulatory effects on the TLR9/NF-κB signaling pathway after destroying the gut microbiota with broad-spectrum antibiotics. These results indicated that RA attenuated SE-induced inflammation by regulating the TLR9/NF-κB signaling pathway and maintaining the homeostasis of the gut microbiota. Our study provides a new strategy for preventing SE-induced intestinal inflammation.

Targeting Nrf2 signaling in dry eye.

Dry eye, the most common ocular surface disease, can cause ocular surface tissue damage and discomfort symptoms and seriously affect people's quality of life. The etiology of dry eye is diverse, and its pathogenesis is complex. The oxidative stress reaction is considered to be among the important factors in the pathogenesis of dry eye. Therefore, activating the antioxidant system has a potential therapeutic effect on dry eye. Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway is considered the most important antioxidant pathway in the body. The activation of the Nrf2 signaling pathway and its interaction with other pathways are important mechanisms to prevent the occurrence and development of dry eye. This review describes the structure and function of Nrf2, summarizes the changes in the oxidative stress response in dry eye, focuses on the potential mechanism of the Nrf2 signaling pathway in the treatment of dry eye, and, finally, summarizes the drugs that activate the Nrf2 signaling pathway in the treatment of dry eye.