Cytokine Secretion Research Articles

Nucleotide-binding oligomerization domain 1 (NOD1) regulates microglial activation in pseudorabies virus infection

The primary cause of viral encephalitis (VE) is invasion of the central nervous system (CNS) by the virus, which leads to neuroinflammation and poses a significant threat to global public health. Microglia, as CNS-resident macrophages, play a crucial role in neuroinflammation and are often identified as the preferred target for the prevention or treatment of VE. In this study, we used pseudorabies virus (PRV)-induced VE in mice and pigs as a model to investigate the regulation of microglial responses during viral encephalitis and explored the mechanism of microglial activation. Cellular experiments revealed that microglial activation was accompanied by cell migration, characteristic morphological changes, phagocytosis, inflammatory cytokine production, and antigen presentation. Transcriptome analysis revealed that genes related to inflammation in PRV-infected BV2 cells were significantly enriched. The expression of the NOD1 gene in BV2 cells was significantly increased during PRV infection, after which NOD1 in BV2 cells was silenced by siRNA and overexpressed via a plasmid. NOD1 was found to be involved in the secretion of cytokines in BV2 cells by regulating the MAPK/NF-κB signalling pathway. Mouse and pig experiments have shown that NOD1 is involved in the secretion of cytokines by microglia by regulating the MAPK/NF-κB signalling pathway during PRV infection.

Applications of physical exercise in frailty: Progress, mechanisms, and prospects

Frailty is a kind of clinical state or a kind of complex pathological syndromes characterized by impaired physiological functions, weakened physical and mental resistance to stress, and reduced ability to maintain homeostasis in multiple systems. Several types of risk factors can affect the occurrence and development of frailty either independently or in conjunction with one another, including age, gender, and exercise habits; and the multidimensional systemic treatment are often required to alleviate or improve frailty. Physical exercise is the various kinds of systematic and conscious activities, it has been demonstrated that regular exercise can promote the normal metabolism processes within the body, thereby preventing or alleviating the symptoms of various diseases. Physical exercise has the potential to regulate oxidative stress, immune response, and endocrine balance in the body of frail people by activating multiple signaling pathways including mitochondrial function, cytokine secretion, and regulation of inflammatory factors, its applications in frailty has been made the significant progress and the underlying mechanisms has been further elucidated. In this review, we have summarized the recent progress on the applications of physical exercise in frailty and the potential mechanisms, hoping that our reviews may provide some helpful guidance for the further research.

Virological and Immunological Characteristics of HBeAg-Positive Chronic Hepatitis B Patients With Low HBsAg Levels.

HBeAg-positive chronic hepatitis B (CHB) with low HBsAg levels represents a relatively rare serological pattern and is closely associated with the severity of liver disease. However, the underlying mechanisms in such cases remain largely unclear. Treatment-naïve HBeAg-positive CHB patients with low HBsAg levels in China were enrolled and analysed. Invitro cell experiments and immunoassays were conducted to investigate the effects of the preS2 deletion mutation on virus reproduction and host immune response. Treatment-naïve HBeAg-positive CHB patients with low HBsAg levels (low HBsAg group) exhibited higher fibrosis scores and a greater prevalence of quasispecies mutations introduced by preS2 deletion compared to patients with positive HBeAg and high HBsAg levels (high HBsAg group). Further analysis revealed that fibrosis scores in CHB patients with the preS2 deletion mutations were significantly higher compared to both in wild-type patients and the high HBsAg group. Invitro assays indicated that while this mutation may not impact HBV replication, it significantly reduced viral infectivity. The number of viral-specific IFN-γ-secreting cells induced by the mutant was significantly lower than that induced by the wild-type strain. Additionally, the levels of HBs-specific B cells and cytokine secretion from lymphocytes triggered by the mutant strain were significantly reduced. HBeAg-positive CHB patients with low HBsAg and genotype C exhibited higher noninvasive fibrosis indexes compared with typical patients, accompanied by a significant increase in quasispecies variants associated with preS2 deletion. The emergence of the preS2 deletion mutants in patients could be due to its enhanced ability to evade the host immunity.

Immune modulation of buffalo peripheral blood mononuclear cells by two asparaginyl endopeptidases from Fasciola gigantica

BackgroundFascioliasis is a zoonotic parasitic disease caused by Fasciola hepatica and Fasciola gigantica, which poses a serious threat to global public health and livestock farming. Fasciola gigantica secretes and excretes various components to manipulate the immune response, thereby enhancing its invasion, migration, and survival in vivo. However, the roles of specific components in immune modulation, such as asparagine endopeptidase, remain unknown.MethodsThe transcriptional abundance of members of the asparagine endopeptidase family (also known as the legumain family) from F. gigantica was analyzed. Two highly transcribed asparagine endopeptidases in metacercariae, juveniles and adults were cloned, and their recombinant proteins—recombinant F. gigantica legumain (rFgLGMN-1) and (rFgLGMN-2)—were expressed in prokaryotic expression system. Their regulatory effects on buffalo peripheral blood mononuclear cells (PBMCs), including proliferation, migration, total nitric oxide (NO) production, cytokine secretion, and phagocytosis were explored in vitro.ResultsTen members of the legumain family were detected in F. gigantica, among of which FgLGMN-1 and FgLGMN-2 exhibited high transcription levels in juveniles and adults. The isolation of sequences indicated that FgLGMN-1 encodes 409 amino acids, while FgLGMN-2 encodes 403 amino acids. Both recombinant FgLGMN-1 (rFgLGMN-1) and rFgLGMN-2 were recognized by serum from buffaloes infected with F. gigantica. Both rFgLGMN-1 and rFgLGMN-2 inhibited the proliferation of PBMCs, and rFgLGMN-1 also inhibited the migration of PBMCs. While rFgLGMN-1 increased the production of total NO, rFgLGMN-2 decreased NO production. Both rFgLGMN-1 and rFgLGMN-2 increased the transcription of the cytokines interleukin-10 and transforming growth factor β. The effect of rFgLGMN-1 and rFgLGMN-2 on the phagocytosis of PBMCs varied depending on their concentrations.ConclusionsrFgLGMN-1 and rFgLGMN-2 modulate several cellular and immunological functions of PBMCs, and exhibited distinct regulatory effects on these in vitro, which indicated that they may play roles in immune modulation and facilitate fluke development. However, due to uncertainties associated with in vitro experiments, further studies are necessary to elucidate the precise functions of these legumains.Graphical

The moderating effect of dietary fiber intake on the association between sleep pattern and liver fibrosis in metabolic dysfunction-associated steatotic liver disease: a study from NHANES

BackgroundInsufficient nocturnal sleep was associated with a higher risk of fibrosis in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Dietary fiber intake may improve the stimulate the secretion of sleep cytokines, inhibit the inflammatory pathway, contribute to regulating sleep disorders and alleviate liver fibrosis. The associations of dietary fiber intake, sleep patterns, with liver fibrosis remain unclear. The study aimed to explore the associations between dietary fiber, sleep, and liver fibrosis, as well as the moderating effect of dietary fiber intake between sleep patterns and liver fibrosis in MASLD patients.MethodsUsing data from the National Health and Nutrition Examination Survey (NHANES) database spanning from 2017 to 2020, a cross-sectional study included participants with MASLD was performed to assess the relationship between sleep patterns, dietary fiber intake, and liver fibrosis. Weighted univariate and multivariate logistic regression models were used to examine the linear connection between sleep pattern, dietary fiber intake, and liver fibrosis. Restricted cubic spline (RCS) method was also performed to describe the nonlinear relationship. A two-part linear regression model was also used to estimate threshold effects. The moderating effect of dietary fiber intake was further investigated in different subgroups. All results were presented as odds ratios (ORs) and 95% confidence intervals (CIs).ResultsTotally, 1343 MASLD patients were included for final analysis. Among them, 207 (15.41%) have liver fibrosis. Dietary fiber intake did not correlate significantly with sleep pattern in patients with MASLD (Spearman’s r = -0.028, P = 0.1678). Poor sleep pattern was related to higher odds of liver fibrosis (OR = 3.23, 95%CI: 1.05–9.90), while dietary fiber intake ≥ 15 gm/day was associated with lower liver fibrosis risk (OR = 0.51, 95%CI: 0.32–0.83). On the association between sleep pattern and liver fibrosis stratified by dietary fiber intake revealed that poor sleep patterns (OR = 15.13, 95%CI: 4.40-52.01) remained associated with increased liver fibrosis risk among individuals with dietary fiber intake < 15 gm/day. No connection was observed between poor sleep patterns and liver fibrosis in MASLD patients with higher dietary fiber intake, with moderate dietary fiber supplementation beneficial in mitigating poor sleep patterns associated with liver fibrosis. The similar findings were also found in patients aged < 50 years old, ≥ 50 years old, females, those with and without CVD groups, hypertension, and dyslipidemia. Particularly, dietary fiber intake also moderates the relationship between sleep patterns and liver fibrosis in the F4 stage (OR = 13.26, 95%CI: 4.08–43.11).ConclusionDietary fiber intake affects the relationship between sleep patterns and liver fibrosis in MASLD patients.

FcRγIIA attenuates pathology of cutaneous leishmaniasis and modulates ITAMa/i balance

BackgroundLeishmania is the causal parasite of leishmaniasis, a neglected tropical disease affecting millions of individuals worldwide, and its dissemination is linked to climate change. Despite the complexity and effectiveness of the immune response, the parasite has developed many strategies to evade it and take control of the host cell to replicate. These evasion strategies start at early stages of infection by hijacking immune receptors to mitigate the cellular response. In this study, we examined whether Leishmania uses the Fc receptor FcγRIIA/CD32a and its downstream signaling pathways to evade the host immune response.MethodsRegarding in vivo studies, CD32a transgenic mice and the corresponding wild types were infected with Leishmania major Friedlin strain. For the in vitro experiments, BMDMs isolated from WT or CD32a transgenic mice and control or CD32a knockdown differentiated THP-1s were infected with two species of Leishmania, Leishmania major and L. tropica.ResultsIn vivo, expression of FcγRIIA/CD32a was found to accelerate the signs of inflammation while simultaneously preventing the formation of necrotic lesions after Leishmania infection. In infected macrophages, the presence of FcγRIIA/CD32a did not affect the secretion of proinflammatory cytokines, while the balance between ITAMa and ITAMi proteins was disturbed with improved Fyn and Lyn activation. Unexpectedly, infection with L. tropica but not L. major triggered an intracytoplasmic processing of FcγRIIA/CD32a.ConclusionsOur observations underscore the significance of FcγRIIA/CD32a in cutaneous leishmaniasis and its potential use as a therapeutic target.Graphical

Functional and phenotypic changes in natural killer cells expressing immune checkpoint receptors PD-1, CTLA-4, LAG-3, and TIGIT in non-small cell lung cancer: the comparative analysis of tumor microenvironment, peripheral venous blood, and tumor-draining veins.

Natural killer (NK) cells are a cytotoxic subset of innate lymphoid cells and have key roles in antitumoral immunity. This study evaluates the roles of immune checkpoint receptors on NK cell phenotype and functions both before and after circulation through tumor tissue. Twenty non-small cell lung cancer patients undergoing surgery and 21 healthy controls were included. Lymphocytes were isolated from peripheral venous blood, tumor-draining venous blood, and tumor tissue. Immune checkpoint receptor (ICR) expressions, intracellular cytokines, and cytotoxic capacity of NK cell subsets were analyzed by flow cytometry. Circulatory levels of sPD-1, sCTLA-4, sLAG-3, and sTIGIT were determined by ELISA. PD-1, CTLA-4, and LAG-3 expressions of both cytotoxic (CD56neg/dimCD16bright) and cytokine-producing (CD56bright/dimCD16neg) NK cells increased in tumor tissue compared to both peripheral and tumor-draining veins. NK cells expressing PD-1, CTLA-4, or LAG-3 had significantly lower IFN- and TNF- and increased IL-10 expressions in tumor tissue compared to peripheral venous blood. The cytotoxic activity (perforin and granzyme A expressions) of NK cells from tumor tissue was significantly reduced compared to peripheral blood. Soluble ICRs decreased in peripheral blood and tumor-draining vein of the patients compared to peripheral blood of healthy individuals. However, NK cell phenotype and functions were similar in peripheral blood and tumor-draining vein. NSCLC tumor microenvironment impacts ICR expressions in NK cells, and ICR-expressing NK cells have impaired inflammatory cytokine secretion and cytotoxic activities with a regulatory phenotype. However, tumor-draining venous blood did not reflect the immune status of the tumor tissue.

The predominant role of FliC contributes to the flagella-related pathogenicity of ST34 S. Typhimurium monophasic variant

Over the past two decades, the monophasic variant of Salmonella enterica serovar Typhimurium (S. Typhimurium) has rapidly emerged and increased worldwide. This upsurge is especially true for the European clone of the ST34 S. Typhimurium monophasic variant. The key distinction between ST34 S. Typhimurium and its monophasic variant is that the genes that encode for second-phase flagellin (FljB) and the regions around it have been replaced with various multidrug resistance cassettes. To determine if the loss of fljB or the retention of fliC,-the gene coding for first-phase flagellin (FliC)-, would impact its pathogenicity, we constructed various mutations, including deletions of fljB, fliC, fliC/fljB, and strains where fliC was replaced with fljB. Our results showed that the loss of fljB in ST34 S. Typhimurium and its monophasic variant does not affect bacterial motility, cell infection ability, survival in macrophages, induced pro-inflammatory cytokines secretion, virulence, or persistent infection in mice. However, the deletion of fliC caused a significant decrease in these outcomes for both strains, while the replacement of fliC with fljB only partially restored these capabilities. Consequently, we determined that FliC is predominant in the flagellar expression of ST34 S. Typhimurium other than FljB. This finding demonstrates that replacing the fljB gene with various resistance regions in ST34 S. Typhimurium monophasic variants can enhance bacterial survival under specific antibiotic farming practices and spread globally.

Epidural injection of varying doses of capsaicin alleviates inflammatory pain in rats via the TLR4/AKT/NF-κB pathway.

Capsaicin (CAP) induces transient pain sensation by activating transient receptor potential vanilloid-1 (TRPV1). However, the initial neuronal excitation induced by CAP is followed by a prolonged refractory period, resulting in long-lasting analgesia. Although the effects of CAP on microglia in the dorsal root ganglion of neuropathic pain disorders have been reported, the regulatory pathways of CAP on microglia remain poorly defined. A chronic pain model was established via plantar injection of complete Freund's adjuvant (CFA), and different doses of CAP were administered to rats. Pain behavior, expression of pain-related factors, protein expression of TRPV1 in nerve cells, and the inflammatory activation of microglia were evaluated. In vitro experiments were conducted to explore the activation and migration ability of microglia, expression of inflammatory cytokines and pathway proteins, TRPV1 expression in nerve cells, and intracellular calcium concentration under different doses of CAP. Different doses of CAP alleviated chronic pain in rats, reduced TRPV1 expression in nerve cells, and inhibited the activation of microglia; however, high doses of CAP were particularly effective in improving chronic pain. In vitro experiments confirmed that CAP reduces the secretion of inflammatory cytokines by microglia via inhibition of the TLR4/AKT/NF-κB signaling pathway. This mechanism reduced the injury and apoptosis of nerve cells, the expression of TRPV1, and the influx of calcium ions in nerve cells. CAP reduced inflammatory responses in microglia in a dose-dependent manner by inhibiting the TLR4/AKT/NF-κB signaling pathway, which consequently reduced TRPV1 expression on neuronal cells and reduced chronic pain.

Engineered Magneto-Piezoelectric Nanoparticles-Enhanced Scaffolds Disrupt Biofilms and Activate Oxidative Phosphorylation in Icam1+ Macrophages for Infectious Bone Defect Regeneration.

Infectious bone defects pose significant clinical challenges due to persistent infection and impaired bone healing. Icam1+ macrophages were identified as crucial and previously unrecognized regulators in the repair of bone defects, where impaired oxidative phosphorylation within this macrophage subset represents a significant barrier to effective bone regeneration. To address this challenge, dual-responsive iron-doped barium titanate (BFTO) nanoparticles were synthesized with magnetic and ultrasonic properties. These nanoparticles were further loaded with the anti-inflammatory agent curcumin and coated with engineered mesenchymal stem cell membranes (EMM) modified with γ3 peptide, creating BFTO-Cur@EMM nanoparticles specifically designed to target Icam1+ macrophages. These nanoparticles were shown to disrupt bacterial biofilms under alternating magnetic fields (AMF) and to activate oxidative phosphorylation and osteogenic immune responses in Icam1+ macrophages via low-intensity pulsed ultrasound (LIPUS). Transcriptomic sequencing and validation experiments demonstrated that this approach activates oxidative phosphorylation (OXPHOS) by stimulating the JAK2-STAT3 pathway and inhibiting the MAPK-JNK pathway, thereby promoting the polarization of Icam1+ macrophages toward a pro-reparative phenotype and enhancing the secretion of pro-angiogenic and osteogenic cytokines. These nanoparticles were subsequently integrated into quaternized chitosan (QCS) and tricalcium phosphate (TCP) to create a bioink for three-dimensional (3D) printing anti-infection QT/BFTO-Cur@EMM bone repair scaffolds. In vivo studies indicated that these scaffolds significantly improved the healing of infectious bone defects without causing thermal damage to surrounding tissues. This work highlights the potential of this material and the targeting of Icam1+ macrophages as an effective strategy for simultaneously controlling infection and promoting bone regeneration.

Current Status of Research on Nanomaterials Combined with Mesenchymal Stem Cells for the Treatment of Ischemic Stroke.

Ischemic stroke (IS) is a disease with high mortality and disability rates worldwide and is a serious threat to patient health. Owing to the narrow therapeutic window, effective treatments during the recovery period are limited. However, in recent years, mesenchymal stem cells (MSCs) have attracted attention and have shown therapeutic potential in IS treatment because of their abilities to home and secrete multiple bioactive substances and potential for differentiation and substitution. The therapeutic mechanisms of MSCs in IS include the regulatory effects of MSCs on microglia, the dual role of MSCs in astrocytes, how MSCs connect innate and adaptive immunity, the secretion of cytokines by MSCs to counteract apoptosis and MSC apoptosis, the promotion of angiogenesis by MSCs to favor the restoration of the blood‒brain barrier (BBB), and the potential function of local neural replacement by MSCs. However, the low graft survival rate, insufficient homing, poor targeting, and inability to achieve directional differentiation of MSCs limit their wide application. As an approach to compensate for the shortcomings of MSCs, scientists have used nanomaterials to assist MSCs in homing, survival and proliferation. In addition, the unique material of nanomaterials adds tracking, imaging and real-time monitoring to stroke treatment. The identification of effective treatments for stroke is urgently needed; thus, an understanding of how MSCs treat stroke and further improvements in the use of nanomaterials are necessary.

Extracellular vesicles from fifth-stage larval Angiostrongylus cantonensis upregulate cholesterol biosynthesis and suppress NLRP2-associated inflammatory responses in mouse astrocytes.

Angiostrongylus cantonensis is a zoonotic parasite that causes severe symptoms in humans, including eosinophilic meningitis and eosinophilic meningoencephalitis. Extracellular vesicles (EVs) derived from helminthes have been implicated in regulating host survival and immune response. However, the roles of A. cantonensis EVs in modulating parasite pathogenesis and host immune response remain poorly understood. Herein, we characterized EVs derived from A. cantonensis fifth-stage larvae (L5) and adult worms. Ultrastructural features showed that EVs from adult worms are smaller in size compared with those from L5. Proteomic analysis identified stage-specific proteins packaged in L5 and adult worm EVs. To investigate the crosstalk between L5 EVs and host cells, RNA sequencing analysis was conducted to identify the differentially expressed genes (DEGs) and enriched biological pathways in mouse astrocytes treated with L5 EVs. GO and KEGG enrichment analysis demonstrated that the pathways related to "cholesterol biosynthesis" are significantly upregulated in L5 EV-treated astrocytes. Based on the transcriptomic data, we observed a downregulated trend of NOD-like receptors (NLRs) protein 2 (NLRP2), a key regulator of brain inflammation, in mouse astrocytes treated with L5 EVs. To validate this result, we utilized ATP to induce the expression of NLRP2 inflammasome-related genes and proteins, as well as the secretion of downstream cytokines. Notably, ATP-induced overexpression of NLRP2 inflammasome-related molecules was significantly reduced in mouse astrocytes upon L5 EV treatment. Collectively, our data suggest that A. cantonensis L5 EVs enhance cholesterol synthesis and potentially modulate immune response by reducing NLRP2 inflammasome-related signaling in non-permissive host cells.IMPORTANCEAngiostrongylus cantonensis is a significant causative agent of eosinophilic meningitis and eosinophilic meningoencephalitis in humans. Helminth-derived extracellular vesicles (EVs) are known to play a crucial role in parasite pathogenesis and host immunomodulation. However, the protein compositions of A. cantonensis EVs and their roles in parasite pathogenesis and host immune response remain unclear. Our results demonstrate for the first time the distinct protein compositions in A. cantonensis L5 and adult worm EVs. The highly abundant proteins in L5 EVs that have immunomodulatory or pathogenic potential in the host deserve further investigation. Additionally, the uptake of L5 EVs by mouse astrocytes significantly upregulates cholesterol synthesis and suppresses ATP-induced NLRP2 inflammasome-related signaling. This study highlights the immunomodulatory roles of L5 EVs in non-permissive hosts, suggesting their potential as therapeutic targets and vaccine candidates against A. cantonensis.

MiRNA Expression: I/R Cardiomyocyte and Sevoflurane

Background: The effects of anesthetic drugs on myocardial cells have been a subject of research for the last 50 years. The clinical benefits of halogenated agents, particularly sevoflurane, have been demonstrated in cardiac surgery patients. These benefits are due to the action of different enzymes and a variety of molecular pathways mediated by the action of small noncoding RNAs (sRNA) such as microRNAs (miRNAs). However, the modulation potential induced by anesthetic drugs on the miRNA expression and their cardioprotective effects is unknown. Objective: To analyze the variation in the expression of a panel of miRNAs induced by halogenated agents to identify their cardioprotective effects. Aims: Variations in the expression of specific miRNAs induce the potential cardioprotective effects of halogenated agents. Methods: An ischemia/reperfusion (I/R) in vitro model of primary human cardiac myocytes (HCMs) was performed. Four study groups were performed: control group (standard culture conditions), I/R group (without hypnotic drugs exposition), I/R-propofol group (I/R-P), and I/R-sevoflurane group (I/R-S). The secretion of p53 and Akt1 cytokines was quantified in the different cell study groups using an Enzyme-Linked ImmunoSorbent Assay, and the differentially expressed miRNAs were identified carrying out a complete genomic sequencing using the Next Generation Sequencing (NGS). Results: HCMs subjected to the I/R procedure and exposed to sevoflurane showed lower secretion levels of p53 factor and higher levels of Akt-1 cytokine compared to HCMs exposed to propofol (p53: I/R-S: 10.43 ± 0.91 ng/mL; I/R-P: 137.92 ± 7.53 ng/mL; p &gt; 0.05); (Akt1: I/R-S: 0.62 ± 0.12 ng/mL; I/R-P: 0.23 ± 0.05 ng/mL; p &gt; 0.05). The miRNA gene expression analysis (NGS) showed significantly increased expression of the hsa-miR-140-5p and hsa-miR-455-5p, both miRNAs associated with cardiac function; the hsa-miR-98-5p and hsa-miR-193a-5p, both related to apoptosis inhibition; and the hsa-let-7d-5p associated with myocardial protection. This increase was observed in the HCMs group exposed to sevoflurane in comparison to the propofol group. Conclusions: Sevoflurane-induced miRNAs overexpression confers cardioprotection through various mechanisms at the DNA level and the different signaling pathways levels, such as Akt/ERK.

H2S-Scavenging Hydrogel Alleviating Mitochondria Damage to Control Periodontitis.

H2S, as a typical metabolite of periodontal pathogens, exhibits a clear positive correlation with the occurrence and development of periodontitis. H2S at physiological concentrations can regulate many biological processes. However, excess H2S in the periodontal pocket can trigger secretion of proinflammatory cytokines, cause oxidative stress, and result in mitochondrial damage and cell death in human gingival fibroblasts, exacerbating periodontitis development and periodontal tissue destruction. Worse, H2S facilitates bacteria survival and proliferation by maintaining bacterial redox balance and enhancing antibiotic resistance. Unfortunately, scavenging H2S during periodontitis treatment is usually ignored. Herein, a kind of hyaluronic acid methacryloyl/ZnO (HMZ) composite hydrogel with an H2S-scavenging ability was prepared to enhance periodontitis treatment. The HMZ hydrogel possessed good injectability and cytocompatibility and was able to remove H2S by a reaction with ZnO. As a result, the HMZ hydrogel was able to increase cell viability from 13% to 120% for human gingival fibroblasts and 22% to 94% for human periodontal ligament fibroblasts at 48 h, restore mitochondrial homeostasis, and alleviate cGAS-STING signaling pathway-mediated inflammation. Meanwhile, the HMZ hydrogel showed satisfactory antibacterial properties and efficiency of plaque biofilm removal. The in vivo results further confirmed that HMZ hydrogel decreased the concentration of H2S within the periodontal pocket from 0.7 to 0.8 mM to the normal level (0.3 to 0.4 mM), killed the bacteria in the periodontal tissues, inhibited osteoclast activity, relieved excess inflammation, and decreased the vertical distance between the cementoenamel junction and the alveolar bone crest from 1,175 µm to 798 µm on the 7th day and from 1,075 µm to 693 µm on the 14th day, achieving efficient periodontal bone regeneration. In brief, an H2S scavenging-based promising strategy was developed to enhance the therapeutic efficiency of periodontitis.

LXR regulation of adipose tissue inflammation during obesity is associated with dysregulated macrophage function.

Liver X receptors (LXRs) play essential roles in cholesterol homeostasis and immune response. In obesity, elevated cholesterol levels trigger proinflammatory responses; however, the specific contributions of LXRs to adipose tissue (AT) macrophage (ATM) phenotype and metabolic programming are not fully understood. In this study, we determine the role of LXR isoforms in diet-induced obesity AT inflammation and insulin resistance. For in vivo studies, to evaluate the effects of LXR activation on AT inflammation, obese and insulin-resistant wild-type mice were treated with 10 mg/kg of the LXR modulator naringenin (NAR) for 4 weeks, and systemic insulin sensitivity and AT inflammation were assessed. To evaluate the effects of LXR deficiency on AT inflammation, we used LXRα, LXRβ, and LXRαβ knockout (KO) mice. For in vitro studies, to assess the role of LXRs specifically in macrophages, bone marrow-derived macrophages from wild-type, LXRαKO, LXRβKO, and LXRαβKO mice were treated with 0.5μM NAR 1 h prior to lipopolysaccharide (LPS) stimulation (100 ng/mL), and the effects on macrophage function and metabolism were evaluated 24 h after LPS stimulation. We found that LXR deletion intensifies AT inflammation in an LXRβ-dependent manner. LXR deficiency in immune cells exacerbates obesity-induced AT inflammation, increasing the numbers of CD11c+, TNF-α+, and IL-1β+ ATMs. We also identified NAR as a novel LXR agonist in macrophages that reduces proinflammatory cytokine secretion by mitigating glycolysis and mitochondrial dysfunction in LPS - and LPS + IFNγ-activated macrophages. Furthermore, NAR-treated obese mice display reduced AT inflammation, characterized by decreased CD11c+, IL-1β+, and TNF-α+ ATM numbers and monocyte infiltration compared with vehicle-treated obese mice. Our study highlights distinct roles for each LXR isoform in AT inflammation regulation, with LXRβ being crucial for maintaining the anti- and proinflammatory balance in ATMs. Thus, LXRβ holds therapeutic potential as a target to treat AT inflammation and insulin resistance.

Harnessing Nature's Arsenal: Phytoconstituents targeting mediators involved in pathogenesis of Asthma

Abstract: Asthma is a persistent respiratory disorder characterized by inflammation and con-striction of the air passages, resulting in recurrent symptoms, including difficulty breathing, wheezing, coughing, and a sensation of tightness in the chest. It requires ongoing management through medications and lifestyle adjustments. The use of natural bioactive compounds in asthma management is on the rise. Researchers are increasingly exploring the potential of compounds derived from plants and herbs, such as quercetin, resveratrol, and Boswellia ex-tracts, for their anti-inflammatory and bronchodilator properties. Compounds like quercetin and resveratrol are known to reduce inflammation by inhibiting enzymes like PDE4 and LOX-5, which play key roles in asthma-related inflammation. They can additionally regulate im-mune reactions by inhibiting the secretion of pro-inflammatory cytokines like “IL-6, IL-5, and IL-4”. Additionally, some compounds, like those found in Boswellia extracts, inhibit NF-κB activation, which further reduces the production of inflammatory mediators. These natural remedies offer a promising avenue for complementing traditional asthma treatments, potential-ly providing relief from symptoms and reducing the reliance on synthetic drugs. The aim of this review is to offer an outline of well-researched plant-derived phytoconstituents that influ-ence cellular activity to control inflammatory mediators associated with asthma. Nevertheless, additional high-quality research is essential to validate the clinical effectiveness of plant-based treatments for asthma.

Human airway macrophages are metabolically reprogrammed by IFN-γ resulting in glycolysis-dependent functional plasticity

Airway macrophages (AM) are the predominant immune cell in the lung and play a crucial role in preventing infection, making them a target for host directed therapy. Macrophage effector functions are associated with cellular metabolism. A knowledge gap remains in understanding metabolic reprogramming and functional plasticity of distinct human macrophage subpopulations, especially in lung resident AM. We examined tissue-resident AM and monocyte-derived macrophages (MDM; as a model of blood derived macrophages) in their resting state and after priming with IFN-γ or IL-4 to model the Th1/Th2 axis in the lung. Human macrophages, regardless of origin, had a strong induction of glycolysis in response to IFN-γ or upon stimulation. IFN-γ significantly enhanced cellular energetics in both AM and MDM by upregulating both glycolysis and oxidative phosphorylation. Upon stimulation, AM do not decrease oxidative phosphorylation unlike MDM which shift to ‘Warburg’-like metabolism. IFN-γ priming promoted cytokine secretion in AM. Blocking glycolysis with 2-deoxyglucose significantly reduced IFN-γ driven cytokine production in AM, indicating that IFN-γ induces functional plasticity in human AM, which is mechanistically mediated by glycolysis. Directly comparing responses between macrophages, AM were more responsive to IFN-γ priming and dependent on glycolysis for cytokine secretion than MDM. Interestingly, TNF production was under the control of glycolysis in AM and not in MDM. MDM exhibited glycolysis-dependent upregulation of HLA-DR and CD40, whereas IFN-γ upregulated HLA-DR and CD40 on AM independently of glycolysis. These data indicate that human AM are functionally plastic and respond to IFN-γ in a manner distinct from MDM. These data provide evidence that human AM are a tractable target for inhalable immunomodulatory therapies for respiratory diseases.

Human airway macrophages are metabolically reprogrammed by IFN-γ resulting in glycolysis-dependent functional plasticity.

Airway macrophages (AM) are the predominant immune cell in the lung and play a crucial role in preventing infection, making them a target for host directed therapy. Macrophage effector functions are associated with cellular metabolism. A knowledge gap remains in understanding metabolic reprogramming and functional plasticity of distinct human macrophage subpopulations, especially in lung resident AM. We examined tissue-resident AM and monocyte-derived macrophages (MDM; as a model of blood derived macrophages) in their resting state and after priming with IFN-γ or IL-4 to model the Th1/Th2 axis in the lung. Human macrophages, regardless of origin, had a strong induction of glycolysis in response to IFN-γ or upon stimulation. IFN-γ significantly enhanced cellular energetics in both AM and MDM by upregulating both glycolysis and oxidative phosphorylation. Upon stimulation, AM do not decrease oxidative phosphorylation unlike MDM which shift to 'Warburg'-like metabolism. IFN-γ priming promoted cytokine secretion in AM. Blocking glycolysis with 2-deoxyglucose significantly reduced IFN-γ driven cytokine production in AM, indicating that IFN-γ induces functional plasticity in human AM, which is mechanistically mediated by glycolysis. Directly comparing responses between macrophages, AM were more responsive to IFN-γ priming and dependent on glycolysis for cytokine secretion than MDM. Interestingly, TNF production was under the control of glycolysis in AM and not in MDM. MDM exhibited glycolysis-dependent upregulation of HLA-DR and CD40, whereas IFN-γ upregulated HLA-DR and CD40 on AM independently of glycolysis. These data indicate that human AM are functionally plastic and respond to IFN-γ in a manner distinct from MDM. These data provide evidence that human AM are a tractable target for inhalable immunomodulatory therapies for respiratory diseases.

Cathelicidin: Insights into Its Impact on Metabolic Syndrome and Chronic Inflammation

Background/Objectives: LL-37 is associated with metabolic syndrome (MetS), a constellation of risk factors comprising obesity, insulin resistance (IR), dyslipidemia, and hypertension, which elevates the risk of cardiovascular disease and type 2 diabetes. Methods: In this narrative review, we analyzed the literature focusing on recent developments in the relationship between cathelicidin and various components of MetS to provide a comprehensive overview. Results: Studies have shown that LL-37 is linked to inflammation in adipose tissue (AT) and the development of IR in obesity. Cathelicidin can enhance inflammation by activating pro-inflammatory genes, as well as modulate the inflammatory response. The mechanisms of IR include the activation of complex signaling pathways that induce inflammation and reduce insulin signaling in adipocytes. The activation of Toll-like receptors (TLRs) by cathelicidin stimulates the secretion of pro-inflammatory cytokines, contributing to the disruption of insulin function in adipose cells. Cathelicidin also influences lipid metabolism, with recent research showing a negative relationship between LL-37 levels and HDL cholesterol. Therefore, LL-37 is involved not only in the regulation of inflammation but also in lipid metabolism, potentially aggravating the cardiovascular complications associated with MetS. Conclusions: Cathelicidin plays a crucial role in regulating the balance between inflammatory and anti-inflammatory responses in MetS. Understanding the impact of LL-37 on these mechanisms may unveil novel approaches for addressing MetS and its associated complications.

Dual‐functional Nanosized Albumin Facilitates CRISPR‐Cas9‐PAR2 to Mitigate Cytokine Storm via TLR4 and Pyroptosis Signaling

AbstractProtease‐activated receptor 2 (PAR2) widely modulates various cytokine secretions and inflammatory responses, while excessive cytokine releases and immune hyperactivation may trigger cytokine storm. However, the potential participation of PAR2 in cytokine storm remains elusive. CRISPR‐Cas9 as an efficient gene editing tool can be used for investigating the possible function of PAR2. In this study, albumin‐based nanoparticles (hAlbumin/cgPAR2) to protect and deliver CRISPR‐Cas9 for precise gene editing of PAR2 is constructed. Nanosized albumin largely assisted CRISPR‐Cas9‐PAR2 (cgPAR2) to enter cells via scavenger receptor‐mediated endocytosis, and then triggered potent transfection efficiency, consequently stimulating PAR2 knockout in vitro and in vivo. Apart from delivering CRISPR‐Cas9, nanosized albumin could be colocalized with TLR4 on endosome and promote PAR2 deficiency to attenuate TLR4/NF‐κB signaling, exerting the strong inhibitory effect of albumin in inflammatory responses depending on TLR4. Moreover, PAR2 deficiency induced by hAlbumin/cgPAR2 alleviated ERK/STING/NLRP3 signaling and GSDMD‐mediated pyroptosis, consequently inhibiting cytokine storm. Therefore, this study uncovered dual functions of nanosized albumin in delivering CRISPR‐Cas9 and facilitating PAR2 deficiency to prevent cytokine storm. It also uncovered that the significant role of PAR2 in modulating cytokine storm and provided a potential gene therapy strategy for treating this disease.