Tissue Neutrophil Infiltration Research Articles

Fibrin aggravates periodontitis through inducing NETs formation from mitochondrial DNA.

This study investigated the role of fibrin on neutrophil extracellular traps (NETs) formation from neutrophils and to elucidate the involvement of mitochondria in NETs formation during periodontitis. Plasminogen-deficient (Plg-/-) mice were employed to evaluate the effects of fibrin deposition on inflammation, bone resorption, and neutrophil infiltration in periodontal tissues. In addition, invitro tests evaluated fibrin's impact on neutrophil-driven inflammation. Mitochondrial reactive oxygen species (mtROS) levels within neutrophils were quantified utilizing flow cytometry and immunofluorescence invitro. Furthermore, the anti-inflammatory properties of the mtROS scavenger, Mito-TEMPO, were confirmed to regulate the NET formation invitro and invivo. Plasminogen deficiency resulted in increased fibrin deposition, neutrophil infiltration, inflammatory factors concentration, and alveolar bone resorption in periodontal tissues. After neutrophils were treated by fibrin invitro, the expression of inflammatory factors, the formation of mtROS, and NETs enriched in mitochondrial DNA (mtDNA) were upregulated, which were reversed by Mito-TEMPO invitro. Moreover, Mito-TEMPO alleviated inflammation in Plg-/- mice. This study showed that fibrin deposition in gingiva induced the NET formation in Plg-/- mice, in which the DNA in NETs was from mitochondria depending on increasing mtROS.

Mechanism of total saponins of Panax japonicus against liver injury induced by acetaminophen in mice based on ERK/NF-κB/COX-2 signaling pathway

This study investigated the effects and mechanisms of total saponins of Panax japonicus(TSPJ) against liver injury induced by acetaminophen(APAP). Male Kunming mice were randomly divided into a blank control group, TSPJ group(200 mg·kg~(-1), ig), model group, APAP+ TSPJ low-dose group(50 mg·kg~(-1), ig), APAP+ TSPJ medium-dose group(100 mg·kg~(-1), ig), APAP+ TSPJ high-dose group(200 mg·kg~(-1), ig), and APAP+ N-acetyl-L-cysteine group(200 mg·kg~(-1), ip). The administration group received the corresponding medications via ig or ip once a day for 14 consecutive days. After the last administration for one hour, except for the blank control group and TSPJ group, all groups of mice were given 500 mg·kg~(-1) APAP by gavage. After 24 hours, mouse serum and liver tissue were collected for serum alanine aminotransferase(ALT), aspartate aminotransferase(AST), reactive oxygen species(ROS), tumor necrosis factor alpha(TNF-α), interleukin-1 beta(IL-1β), cyclooxygenase-2(COX-2), IL-6, IL-4, IL-10, as well as lactate dehydrogenase(LDH), glutathione(GSH), superoxide dismutase(SOD), catalase(CAT), total antioxidant capacity(T-AOC), malondialdehyde(MDA), and myeloperoxidase(MPO) liver tissue. Hematoxylin-eosin staining was used to observe the morphological changes of liver tissue. The mRNA expression levels of lymphocyte antigen 6G(Ly6G), galectin 3(Mac-2), TNF-α, IL-1β, COX-2, IL-6, IL-4, and IL-10 in liver tissue were determined by quantitative real-time polymerase chain reaction(PCR). Western blot was utilized to detect the protein expression levels of Ly6G, Mac-2, extracellular regulated protein kinases(ERK), phosphorylated extracellular regulated protein kinases(p-ERK), COX-2, inhibitor of nuclear factor κB protein α(IκBα), phosphorylated inhibitor of nuclear factor κB protein α(p-IκBα), and nuclear factor-κB subunit p65(NF-κB p65) in cytosol and nucleus in liver tissue. The results manifested that TSPJ dramatically reduced liver coefficient, serum ALT, AST, ROS, TNF-α, IL-1β, IL-6, and COX-2 levels, LDH, MPO, and MDA contents in liver tissue, and mRNA expressions of TNF-α, IL-1β, and IL-6 in APAP-induced liver injury mice. It prominently elevated serum IL-4 and IL-10 levels, GSH, CAT, SOD, and T-AOC contents, and mRNA expressions of IL-4 and IL-10 in liver tissue, improved the degree of liver pathological damage, and suppressed neutrophil infiltration and macrophage recruitment in liver tissue. In addition, TSPJ lessened the mRNA and protein expressions of neutrophil marker Ly6G, macrophage marker Mac-2, and COX-2 in liver tissue, protein expressions of p-ERK, p-IκBα, and NF-κB p65 in nuclear, and p-ERK/ERK and p-IκBα/p-IκBα ratios and hoisted protein expression of NF-κB p65 in cytosol. These results suggest that TSPJ has a significant protective effect on APAP-induced liver injury in mice, and it can alleviate APAP-induced oxidative damage and inflammatory response. Its mechanism may be related to suppressing ERK/NF-κB/COX-2 signaling pathway activation, thus inhibiting inflammatory cell infiltration, cytokine production, and liver cell damage.

Thermoresponsive gel containing bilirubin nanoparticles exerts anti-inflammatory effects by inhibiting neutrophil infiltration and augmenting interleukin-10 levels in carrageenan-induced rat paw edema.

Topical corticosteroids treat cutaneous inflammation but have side effects. In earlier studies, bilirubin exhibited anti-inflammatory effect, but its hydrophobicity and poor absorption limit its potential. Synthesis of bilirubin nanoparticles (BNP) and bilirubin nanoparticles gels (BNP gel) to study the anti-inflammatory effect of topical BNP gel against carrageenan-induced rat paw edema in Wistar rats. BNP were synthesized, and BNP gels were prepared by mixing BNP of different concentrations with pluronic F-127 (PF-127). A different group for each formulation was assigned with five rats in each group. After 1 h of carrageenan (1% [w/v]) injection in each group, different gels were applied topically to their respective groups. Paw edema size, percent inflammation, percent edema inhibition, and inhibition time50 were evaluated. Interleukin-10 (IL-10) levels and neutrophil infiltration in rat paw tissue were evaluated by enzyme-linked immunosorbent assay and hematoxylin and eosin, respectively. Synthesized spherical-shaped BNP had negative zeta potential. BNP gels markedly reduced paw edema size and % inflammation as compared to carrageenan and bulk bilirubin gel (Bulk B gel) treated group and significantly increased IL-10 levels and inhibited neutrophil infiltration. BNP gels exhibited a better anti-inflammatory effect than bulk B gel and comparable anti-inflammatory potential with clobetasol.

A convergent evolutionary pathway attenuating cellulose production drives enhanced virulence of some bacteria

Bacteria adapt to selective pressure in their immediate environment in multiple ways. One mechanism involves the acquisition of independent mutations that disable or modify a key pathway, providing a signature of adaptation via convergent evolution. Extra-intestinal pathogenic Escherichia coli (ExPEC) belonging to sequence type 95 (ST95) represent a global clone frequently associated with severe human infections including acute pyelonephritis, sepsis, and neonatal meningitis. Here, we analysed a publicly available dataset of 613 ST95 genomes and identified a series of loss-of-function mutations that disrupt cellulose production or its modification in 55.3% of strains. We show the inability to produce cellulose significantly enhances ST95 invasive infection in a rat model of neonatal meningitis, leading to the disruption of intestinal barrier integrity in newborn pups and enhanced dissemination to the liver, spleen and brain. Consistent with these observations, disruption of cellulose production in ST95 augmented innate immune signalling and tissue neutrophil infiltration in a mouse model of urinary tract infection. Mutations that disrupt cellulose production were also identified in other virulent ExPEC STs, Shigella and Salmonella, suggesting a correlative association with many Enterobacteriaceae that cause severe human infection. Together, our findings provide an explanation for the emergence of hypervirulent Enterobacteriaceae clones.

Synergistic Anti-Inflammatory Activity of Apolipoprotein A-I and CIGB-258 in Reconstituted High-Density Lipoproteins (rHDL) against Acute Toxicity of Carboxymethyllysine in Zebrafish and Its Embryo.

CIGB-258 is a 3 kDa altered peptide ligand from heat shock protein (HSP) 60 that exhibits anti-inflammatory activity against the acute toxicity of carboxymethyllysine (CML) with antioxidant and anti-glycation activities via protection of high-density lipoprotein (HDL) and apolipoprotein A-I (apoA-I). It is necessary to test a synergistic interaction between apoA-I and CIGB-258 in reconstituted high-density lipoproteins (rHDL). Several rHDLs were synthesized containing palmitoyloleoyl phosphatidylcholine (POPC), cholesterol, apoA-I, and CIGB-258 at molar ratios of 95:5:1:0, 95:5:1:0.1, 95:5:1:0.5, and 95:5:1:1 for rHDL-(1:0), rHDL-(1:0.1), rHDL-(1:0.5), and rHDL-(1:1), respectively. As the CIGB-258 content in rHDL was increased, the particle size of rHDL was 1.4-times higher than rHDL-(1:0) to rHDL-(1:1), from 60 nm to 83 nm, respectively. As the CIGB-258 content was increased, the rHDL showed the most resistance to isothermal denaturation by a urea treatment, and rHDL-(1:1) exhibited the highest structural stability and the strongest antioxidant ability against LDL oxidation. Co-treatment of rHDL-(1:0), rHDL-(1:0.5), and rHDL-(1:1) resulted in up to 10%, 24%, and 34% inhibition of HDL glycation, inhibition of HDL glycation, which was caused by the CML, with protection of apoA-I. Microinjection of each rHDL into zebrafish embryos in the presence of CML showed that a higher CIGB-258 content in rHDL was associated with higher survivability with the least inflammation and apoptosis. Furthermore, an intraperitoneal injection of rHDL and CML showed that a higher CIGB-258 content in rHDL was also associated with higher survivability of zebrafish and faster recovery of swimming ability. The rHDL-(1:1) group showed the lowest triglyceride, AST, and ALT serum levels with the least production of interleukin-6, oxidized product, and neutrophil infiltration in hepatic tissue. In conclusion, CIGB-258 could bind well to phospholipids and cholesterol to stabilize apoA-I in the rHDL structure against denaturation stress and larger particle sizes. The rHDL containing CIGB-258 enhanced the in vitro antioxidant ability against LDL oxidation, the anti-glycation activity to protect HDL, and the in vivo anti-inflammatory activity against CML toxicity in zebrafish adults and embryos. Overall, incorporating apoA-I and CIGB-258 in rHDL resulted in a synergistic interaction to enhance the structural and functional correlations in a dose-dependent manner of CIGB-258.

Methylprednisolone pulse-enhanced neutrophil extracellular trap formation in mice with imiquimod-induced lupus-like disease, resulting in ischaemia of the femoral head cartilage

ObjectivesMethylprednisolone (mPSL) pulse therapy is an essential option for patients with active systemic lupus erythematosus, but there is a risk of adverse events related to microcirculation disorders, including idiopathic osteonecrosis...

Catheter-associated bladder mucosal trauma during intermittent voiding: An experimental study in pigs.

The objective of this study is to characterize bladder mucosal trauma associated with intermittent catheterization with conventional eyelet catheters (CECs) and to assess if a microhole zone catheter (MHZC) design concept reduces this adverse effect. A porcine model was developed to reflect human catheterization and bladder drainage. Nine pigs were randomized for catheterization with CEC (n= 6) or MHZC (n= 3). The bladder was drained repeatedly 20 times through the catheter. Cystoscopy was performed before and after the procedure, and bladders were analysed by histopathology. Two additional pigs were used for cystoscopy visualization of suction events in vivo. Cystoscopy, gross pathology, histopathological score, leucocyte infiltration, and intracatheter pressure at flow stops during voiding were compared for each group. A significant higher pressure gradient was measured inside the CECs compared with MHZCs during flow stop. Consequently, CECs resulted in suction events inflicting bladder trauma characterized by loss of epithelium, oedema, haemorrhage, and neutrophil tissue infiltration. No significant trauma was identified when using MHZC. Considerable mucosal bladder trauma is inflicted by CECs which may be an overlooked risk factor for urinary tract infection. Catheters can be designed to minimize mucosal suction and reduce associated trauma. This may be a solution to reduce infection frequency and increase user comfort. Furthermore, the study demonstrates the potential of pigs as an attractive animal model for investigating urinary catheter performances.

Systemic and local responses of cytokines and tissue histology following intramammary lipopolysaccharide challenge in dairy cows

During bovine mastitis, immune responses include the release of cytokines and the recruitment of leukocytes, resulting in profound structural and functional changes in the mammary gland. Our aims were to delineate systemic and local cytokine responses and to quantify histological changes in the mammary tissue of lactating cows after acute intramammary lipopolysaccharide (LPS) challenge. Ten multiparous dairy cows were paired to either treatment (TRT) or control (CON) groups. For TRT cows, one side of the udder was randomly assigned to receive treatment with LPS (50 µg in 10 mL of saline, TL) into both the front and rear quarters; the contralateral quarters received saline (10 mL). Udder-halves of CON cows were similarly assigned randomly to receive either saline (10 mL, CS) or no infusion (untreated). Temporal changes in the concentrations of 15 cytokines in the blood (0, 3, 6, 12, and 24 h relative to the LPS infusion) and in mammary tissue (0, 3, and 12 h) were determined, as were concomitant changes in mammary histology. The cytokines IL-6, IL-10, MCP-1, and MIP-1β showed a systemic response as their concentrations were significantly different in the plasma of TRT cows as compared with CON cows after LPS challenge. The cytokines IL-1α, IL-1β, IL-6, IL-8, IL-17A, IL-36RA, IP-10, MCP-1, MIP-1α, MIP-1β, TNF-α, and VEGF-A showed a local response in TL glands, and 8 cytokines, IL-1β, IL-6, IL-10, IL-17A, IL-36RA, IP-10, MIP-1β, and VEGF-A showed systemic changes in the nonchallenged mammary glands adjacent to LPS-infused glands. Endotoxin challenge evoked changes in the histology of mammary tissue that included a 5.2- and 7.2-fold increases in the number of neutrophils in alveolar lumens at 3 h and 12 h, respectively. In summary, LPS challenge induced specific local and systemic responses in cytokine induction and elicited neutrophil infiltration in bovine mammary tissue.

Subgingival titanium wire implantation induces weak inflammatory responses but does not promote substantial T cell activation.

Titanium is a biocompatible material commonly used for dental treatments. However, the detailed mechanism underlying the weak biological activity of titanium has not been elucidated. We investigated both the inflammatory responses and T cell activation induced by solid titanium in the gingiva in mice. Both titanium and nickel wire implantation promoted neutrophil infiltration into the gingiva on day 2. Nickel, but not titanium, wire implantation enhanced proinflammatory cytokine expression and dendritic cell activity in gingival tissue by day 2. Nickel wire implantation enhanced the activity of T cells in draining lymph nodes on day 5. Moreover, T cell and neutrophil infiltration and elevated proinflammatory cytokine expression in the gingival tissue were still observed on day 5. However, no such augmented biological responses were observed after titanium wire implantation. These findings suggest that, unlike nickel, solid titanium does not induce sufficient inflammatory responses leading to T cell activation in gingival tissue.

The inflammatory microenvironment of nasal polyps in patients with chronic rhinosinusitis and the relationship of this microenvironment with the nasal microbiome

BackgroundWe investigated the characteristics of the microbial community of the nasal sinuses in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and identified the correlations of the nasal microbiome with the inflammatory microenvironment of the nasal cavity. MethodologyWe collected matched nasal secretion and polyp tissue samples from 77 CRSwNP patients. Then, we extracted microbial DNA from cotton swabs, used high-throughput sequencing technology based on 16S ribosomal RNA (rRNA) to detect the bacterial community composition, and detected cytokines such as interleukin (IL)-5, IL-8, IL-17a, IL-17e, IL-18, IL-27 and interferon (INF)-gamma in the polyp tissue samples using Luminex. Eosinophils and neutrophils in the peripheral blood and polyp tissue were counted, and the relationships between inflammatory factors or inflammatory cell counts and nasal microbial diversity were analyzed. ResultsAmong the inflammatory factors evaluated, IL-5 had a positive rate of 32.47%, IFN-γ had a positive rate of 84.42%, IL-17A and IL-17E had positive rates of 75.32%, IL-18 had a positive rate of 94.81%, IL-27 had a positive rate of 68.83%, and IL-8 had a positive rate of 100%. IL-17a and IL-27 were negatively correlated with both Enterobacter and Anaerococcus, IL-8 was negatively correlated with both Enterobacter and Staphylococcus, IL-18 was positively correlated with Candidatus Arthromitus and negatively correlated with Haemophilus, and IL-27 was positively correlated with Faecalibaculum. Lactobacillus and Enterococcus were positively correlated with the degree of neutrophil infiltration in nasal polyp tissue. ConclusionsIn Southwest China, inflammation of the nasal polyps exhibits a variety of patterns. Enterobacteria and anaerobic bacteria may be correlated with the inflammatory pattern of nasal polyps. The neutrophil-mediated inflammatory response plays an important role in patients with CRSwNP in Southwest China.

An agonistic anti-signal regulatory protein α antibody for chronic inflammatory diseases

Signal regulatory protein (SIRPα) is an immune inhibitory receptor expressed by myeloid cells to inhibit immune cell phagocytosis, migration, and activation. Despite the progress of SIRPα and CD47 antagonist antibodies to promote anti-cancer immunity, it is not yet known whether SIRPα receptor agonism could restrain excessive autoimmune tissue inflammation. Here, we report that neutrophil- and monocyte-associated genes including SIRPA are increased in inflamed tissue biopsies from patients with rheumatoid arthritis and inflammatory bowel diseases, and elevated SIRPA is associated with treatment-refractory ulcerative colitis. We next identify an agonistic anti-SIRPα antibody that exhibits potent anti-inflammatory effects in reducing neutrophil and monocyte chemotaxis and tissue infiltration. In preclinical models of arthritis and colitis, anti-SIRPα agonistic antibody ameliorates autoimmune joint inflammation and inflammatory colitis by reducing neutrophils and monocytes in tissues. Our work provides a proof of concept for SIRPα receptor agonism for suppressing excessive innate immune activation and chronic inflammatory disease treatment.

Investigation of the efficacy of systemic N-Acetyl Cysteine therapy preventing nasal mucositis following radiotherapy.

Radiotherapy (RT) is one of the main methods used in the treatment of head and neck cancers but may cause mucosal side effects in the tumor area and surrounding structures. These include nasal mucosal disorders and chronic rhinosinusitis due to disruption of the mucociliary system. This situation seriously affects the quality of life of the patients and there is no accepted effective method for its treatment yet. In our study, we aimed to examine the side effects of RT on the nasal mucosa and mucociliary system and to investigate histopathologically and immunohistochemically the effectiveness of N-acetyl cysteine (NAC) in preventing these side effects of RT. The study was carried out with 30 female Sprague Dawley rats devided in three groups. No intervention was made in the control group. On the second day of the experiment, 30 Gy radiotherapy was applied to the head area in the RT group. NAC was administered intraperitoneally at a dose of 1 g/kg/day for 14 days from the first day of the study to the RT+ NAC group. On the second day, 30 Gy of radiotherapy was applied to the head area 1 hour after the NAC application. On the 14th day, 1 hour after NAC was applied to the RT+NAC group, all animals were sacrificed. The nasal mucosa samples were stained with hematoxylin-eosin, and the intensity and extent of staining sentan in the nasopharyngeal tissue samples were evaluated by immunohistochemical staining using anti-SNTN antibody. The loss of cilia in the nasal tissue was lower in the RT+NAC group than in the RT group. The intensity and extent of staining in the nasopharyngeal tissue of Sentan was higher in the RT+NAC group than in the RT group. Mucosal neutrophil and mononuclear inflammatory cell infiltration in the nasal tissue, vascular dilatation, hyperemia and hemorrhage, erosion and shedding of the mucosal epithelium, mucosal ulceration were found to be similar in the RT+NAC group and the control group. It was milder in the RT+NAC group than in the RT group, but not statistically significant. Radiotherapy caused pathological changes in the nasal mucosa, caused loss of cilia and a decrease in the level of Sentan, the cilia apical protein. The results of our study showed that NAC treatment can reduce the side effects of RT on the nasal mucosa. It also showed that NAC was effective in preventing the loss of cilia, which is the building block of the mucociliary system, and improving the expression of Sentan.

High salt diet impairs the protective immunity against mucosal HSV-2 infection

Abstract Herpes simplex virus type2 (HSV-2) is the main cause of genital ulcer disease. Because of asymptomatic viral shedding, HSV-2 is highly prevalent and infected nearly 500 million people worldwide. Recently, excessive sodium intake has threatened global health. It is well known that excessive sodium intake affects various diseases by altering gut microbiome. However, the effect of excessive sodium intake on vaginal microbiome and vaginal immune system is unknown. In this study, we investigate the effects of high salt diet on vaginal microbiome and HSV-2 disease progression. We found that high salt diet compromises the anti-viral immunity in a mouse HSV-2 model. In 16S ribosomal RNA sequencing of vaginal microbiome, high salt diet results vaginal dysbiosis. High salt diet induced vaginal dysbiosis promotes neutrophil infiltration in vaginal tissue and vaginal lumen. In addition, Single-cell RNA analysis of vaginal neutrophil reveals dominant increase in neutrophil expressing MMPs that could damage vaginal tissue. Our findings suggest that high salt diet related vaginal dysbiosis impairs antiviral protection via neutrophil recruitment.

Adhesive Ergothioneine Hyaluronate Gel Protects against Radiation Gastroenteritis by Alleviating Apoptosis, Inflammation, and Gut Microbiota Dysbiosis

Radiation gastroenteritis represents one of the most prevalent and hazardous complications of abdominopelvic radiotherapy, which not only severely reduces patients' life quality but also restricts radiotherapy efficacy. However, there is currently no clinically available oral radioprotector for this threatening disease due to its complex pathogenesis and the harsh gastrointestinal environment. To this end, this study developed a facile but effective oral radioprotector, ergothioneine hyaluronate (EGT@HA) gel, protecting against radiation gastroenteritis by synergistically regulating oxidative stress, inflammation, and gut microbiota. In vitro and cellular experiments verified the chemical stability and free radical scavenging ability of EGT and its favorable cellular radioprotective efficacy by inhibiting intracellular reactive oxidative species (ROS) generation, DNA damage, mitochondrial damage, and apoptosis. At the in vivo level, EGT@HA with prolonged gastrointestinal residence mitigated radiation-induced gastrointestinal tissue injury, apoptosis, neutrophil infiltration, and gut flora dysbiosis. For the first time, this work investigated the protective effects of EGT@HA gel on radiation gastroenteritis, which not only hastens the advancement of the novel gastrointestinal radioprotector but also provides a valuable gastrointestinal radioprotection paradigm by synergistically modulating oxidative stress, inflammation, and gut microbiota disturbance.

Lafutidine Ameliorates Indomethacin-Induced Small Intestinal Damage in Rats by Modifying the Intestinal Mucosal Barrier, Inflammation, and Microbiota

Introduction: Nonsteroidal anti-inflammatory drug (NSAID)-induced small intestinal damage is a serious and escalating clinical problem without effective treatment. Lafutidine (LAF) is a novel histamine H2 receptor antagonist with a mucosal protective action. This study aimed to investigate the protective effect of LAF on indomethacin (IND)-induced enteropathy in rats. Methods: Rats were treated with LAF for 10 days with concomitant IND treatment on the final 5 days. Changes in metabolism and hematological and biochemical parameters were measured, and intestinal damage was blindly scored. Intestinal mucosal tissue and luminal contents were collected for transcriptome and microbiota sequencing. Intestinal inflammation and barrier function were also evaluated. Results: LAF treatment prevented anorexia and weight loss in rats and ameliorated reductions in hemoglobin, hematocrit, total protein, and albumin levels. LAF reduced the severity of IND-induced intestinal damage including macroscopic and histopathological damage score. Transcriptome sequencing results indicated that LAF might have positive effects on intestinal inflammation and the intestinal mucosal barrier. Further research revealed that LAF decreased neutrophil infiltration, and IL-1β and TNF-α expression in intestinal tissue. Besides, the treatment increased mucus secretion, MUC2, Occludin, and ZO-1 expression, and decreased serum D-lactate levels. LAF treatment also ameliorates microbial dysbiosis in small intestine induced by IND and increased the abundance of Lactobacillus acidophilus. Conclusion: LAF may protect against NSAID enteropathy via enhancing the intestinal mucosal barrier, inhibiting inflammation, and regulating microbiota.

Deletion of NADPH oxidase 2 attenuates cisplatin-induced acute kidney injury through reducing ROS-induced proximal tubular cell injury and inflammation.

Cisplatin is a commonly used chemotherapeutic agent in cancer treatment. However, its high nephrotoxicity limits its therapeutic application and efficacy. Cisplatin induces nephrotoxicity mainly through oxidative stress and inflammation. Reactive oxygen species (ROS) in the kidneys mainly arise from nicotinamide adenine dinucleotide phosphate (NADPH) oxidases 2 (NOX2), which is highly upregulated during ischemia-reperfusion injury and diabetes mellitus. However, its role in cisplatin-induced acute kidney injury (AKI) remains unknown. A 8-10-week-old NOX2 gene-knockout and wild-type mice were injected with 25 mg/kg cisplatin intraperitoneally for experiments. We investigated the role of NOX2 in cisplatin-induced AKI and found that NOX2-mediated ROS production is a key inflammatory mediator of proximal tubular cell injury in cisplatin-induced AKI. NOX2 gene-knockout alleviated cisplatin-induced renal function decline, tubular injury score, kidney injury molecule-1(Kim-1) expression, and interleukin (IL)-6 and IL-1α levels with a reduction of ROS production. Moreover, in cisplatin-induced AKI, intercellular adhesion molecule 1 (ICAM-1) and the chemoattractant CXC ligand 1 (CXCL1) were highly expressed in association with neutrophil infiltration, which were all attenuated by deletion of NOX2. These data indicate that NOX2 aggravates cisplatin nephrotoxicity by promoting ROS-mediated tissue injury and neutrophil infiltration. Thus, appropriate targeting of NOX2/ROS pathway may minimize the risk of cisplatin-induced kidney injury in patients receiving cancer therapy.

Lipocalin-2 deletion attenuates lipopolysaccharide-induced acute lung inflammation via downregulating chemotaxis-related genes

Lipocalin-2 (LCN2) is an acute phase protein used as a biomarker for acute lung injury (ALI). Although the innate immune functions of LCN2 have been studied, how LCN2 contributes to ALI induced by lipopolysaccharide (LPS) remains unknown. In this study, we investigated the effect of LCN2 deletion on LPS-induced ALI using RNA-sequencing. LPS-treated LCN2 knockout (KO) mice had a decreased histopathological score and reduced neutrophil and macrophage infiltration in lung tissue compared with LPS-treated WT mice. RNA-sequencing analysis identified 38 differentially expressed genes (DEGs), including Cxcl5, Cxcl13, Xcl1, Saa1, and Cd14. In particular, Gene Ontology analysis of DEGs revealed a significant reduction in the inflammatory response, neutrophil chemotaxis, and chemokine-mediated signaling in LPS-treated LCN2KO mice compared with LPS-treated WT mice. Thus, these results suggest that LCN2 deletion alleviates LPS-induced ALI and that LCN2 may be involved in chemotaxis-related gene expression.

β-Cryptoxanthin Attenuates Cigarette-Smoke-Induced Lung Lesions in the Absence of Carotenoid Cleavage Enzymes (BCO1/BCO2) in Mice.

High dietary intake of β-cryptoxanthin (BCX, an oxygenated provitamin A carotenoid) is associated with a lower risk of lung disease in smokers. BCX can be cleaved by β-carotene-15,15'-oxygenase (BCO1) and β-carotene-9',10'-oxygenase (BCO2) to produce retinol and apo-10'-carotenoids. We investigated whether BCX has protective effects against cigarette smoke (CS)-induced lung injury, dependent or independent of BCO1/BCO2 and their metabolites. Both BCO1-/-/BCO2-/- double knockout mice (DKO) and wild type (WT) littermates were supplemented with BCX 14 days and then exposed to CS for an additional 14 days. CS exposure significantly induced macrophage and neutrophil infiltration in the lung tissues of mice, regardless of genotypes, compared to the non-exposed littermates. BCX treatment significantly inhibited CS-induced inflammatory cell infiltration, hyperplasia in the bronchial epithelium, and enlarged alveolar airspaces in both WT and DKO mice, regardless of sex. The protective effects of BCX were associated with lower expression of IL-6, TNF-α, and matrix metalloproteinases-2 and -9. BCX treatment led to a significant increase in hepatic BCX levels in DKO mice, but not in WT mice, which had significant increase in hepatic retinol concentration. No apo-10'-carotenoids were detected in any of the groups. In vitro BCX, at comparable doses of 3-OH-β-apo-10'-carotenal, was effective at inhibiting the lipopolysaccharide-induced inflammatory response in a human bronchial epithelial cell line. These data indicate that BCX can serve as an effective protective agent against CS-induced lung lesions in the absence of carotenoid cleavage enzymes.

Transcriptional Insights of Oxidative Stress and Extracellular Traps in Lung Tissues of Fatal COVID-19 Cases.

Neutrophil extracellular traps (NETs) and oxidative stress are considered to be beneficial in the innate immune defense against pathogens. However, defective clearance of NETs in the lung of acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients could lead to severe respiratory syndrome infection, the so-called coronavirus disease 2019 (COVID-19). To elucidate the pathways that are related to NETs within the pathophysiology of COVID-19, we utilized RNA sequencing (RNA-seq) as well as immunofluorescence and immunohistochemistry methods. RNA-seq analysis provided evidence for increased oxidative stress and the activation of viral-related signaling pathways in post-mortem lungs of COVID-19 patients compared to control donors. Moreover, an excess of neutrophil infiltration and NET formation were detected in the patients' lungs, where the extracellular DNA was oxidized and co-localized with neutrophil granule protein myeloperoxidase (MPO). Interestingly, staining of the lipid peroxidation marker 4-hydroxynonenal (4-HNE) depicted high colocalization with NETs and was correlated with the neutrophil infiltration of the lung tissues, suggesting that it could serve as a suitable marker for the identification of NETs and the severity of the disease. Moreover, local inhalation therapy to reduce the excess lipid oxidation and NETs in the lungs of severely infected patients might be useful to ameliorate their clinical conditions.

Quantitative tissue proteome profile reveals neutrophil degranulation and remodeling of extracellular matrix proteins in early stage gallbladder cancer.

Gallbladder cancer (GBC) is an aggressive malignancy of the gastrointestinal tract with a poor prognosis. It is important to understand the molecular processes associated with the pathogenesis of early stage GBC and identify proteins useful for diagnostic and therapeutic strategies. Here, we have carried out an iTRAQ-based quantitative proteomic analysis of tumor tissues from early stage GBC cases (stage I, n=7 and stage II, n=5) and non-tumor controls (n=6) from gallstone disease (GSD). We identified 357 differentially expressed proteins (DEPs) based on ≥ 2 unique peptides and ≥ 2 fold change with p value < 0.05. Pathway analysis using the STRING database showed, 'neutrophil degranulation' to be the major upregulated pathway that includes proteins such as MPO, PRTN3, S100A8, MMP9, DEFA1, AZU, and 'ECM organization' to be the major downregulated pathway that includes proteins such as COL14A1, COL1A2, COL6A1, COL6A2, COL6A3, BGN, DCN. Western blot and/or IHC analysis confirmed the elevated expression of MPO, PRTN3 and S100A8 in early stage of the disease. Based on the above results, we hypothesize that there is an increased neutrophil infiltration in tumor tissue and neutrophil degranulation leading to degradation of extracellular matrix (ECM) proteins promoting cancer cell invasion in the early stage GBC. Some of the proteins (MPO, MMP9, DEFA1) associated with 'neutrophil degranulation' showed the presence of 'signal sequence' suggesting their potential as circulatory markers for early detection of GBC. Overall, the study presents a protein dataset associated with early stage GBC.