Lycopene Inhibits Toll-Like Receptor 4-Mediated Expression of Inflammatory Cytokines in House Dust Mite-Stimulated Respiratory Epithelial Cells

Lycopene supplementation reduces inflammatory, histopathological and DNA damage in an acute lung injury rabbit model

OBJECTIVE

To investigate the effects of lycopene supplementation on inflammation, lung histopathology and systemic DNA damage in an experimentally induced lung injury model, ventilated by conventional mechanical ventilation and high-frequency oscillatory ventilation, compared with a control group.

METHODS

Fifty-five rabbits sampled by convenience were supplemented with 10mg/kg lycopene for 21 days prior to the experiment. Lung injury was induced by tracheal infusion of warm saline. The rabbits were randomly assigned to the control group and subjected to protective conventional mechanical ventilation (n = 5) without supplementation or the experimental group that was subjected to acute lung injury and provided conventional mechanical ventilation and high-frequency oscillatory ventilation with and without lycopene supplementation (n = 10 rabbits in each group). Lung oxidative stress and the inflammatory response were assessed based on the number of polymorphonuclear leukocytes in bronchoalveolar lavage fluid, DNA damage and pulmonary histological damage.

RESULTS

A significant worsening of oxygenation and a decrease in static lung compliance was noted in all groups after pulmonary injury induction (partial pressure of oxygen before 451.86 ± 68.54 and after 71 ± 19.27, p < 0.05). After 4 hours, the high-frequency oscillatory ventilation groups with and without lycopene supplementation as well as the group receiving protective conventional mechanical ventilation with lycopene supplementation showed significant oxygenation improvement compared with the protective conventional mechanical ventilation group without supplementation (partial pressure of oxygen of the group with mechanical ventilation without lycopene of 102 ± 42, of the group that received conventional protective mechanical ventilation with lycopene supplementation of 362 ± 38, of the high-frequency group without lycopene supplementation of 420 ± 28 and of the high-frequency group with lycopene supplementation of 422 ± 25; p < 0.05). Compared with rabbits not receiving supplementation, those in the groups that received protective conventional mechanical ventilation with lycopene supplementation and high-frequency oscillatory ventilation with lycopene supplementation had significantly less inflammation as well as less histological injury (p < 0.05). Compared with rabbits subjected to protective conventional mechanical ventilation, significantly lower DNA damage was observed in rabbits supplemented with lycopene (p < 0.05).

CONCLUSION

Lycopene supplementation reduces inflammatory and histopathological lung injuries, regardless of the associated ventilatory mode. In addition, lycopene improved oxygenation and reduced DNA damage when protective conventional mechanical ventilation was used.

1-Bromopropane induces mitochondrial damage and lipid metabolism imbalance in respiratory epithelial cells through the PGC-1α/PPARα pathway

1-Bromopropane (1-BP) has become a new air pollutant in occupational and living environments due to its advantages in industrial applications and as a representative compound of volatile organic compounds (VOCs). As an irritant, its damaging effects on respiratory epithelium are worthy of further study. This study aimed to explore the damage effects of 1-BP on respiratory epithelial cells and reveal its underlying mechanisms. We found that exposure to 1-BP markedly reduced the viability of respiratory epithelial cells in a dose-dependent manner, and induced oxidative stress and vacuolation changes in respiratory epithelial cells. Subsequently, through RNA-seq analysis, we identified that the 1-BP-induced damage of respiratory epithelial cells was related to the mitochondrial function pathway and further verified that 1-BP caused mitochondrial damage of respiratory epithelial cells, which was manifested as ultrastructural damage, decreased membrane potential, ATP, and MFN2 levels. These damages were associated with cellular oxidative stress responses. Pretreating cells with the agonists of PGC-1α and PPARα, we revealed that 1-BP affected the expression of PGC-1α and interfered with its coactivator PPARα levels, causing an increase in the expression of lipid-producing genes and a decrease in the expression of lipid-decomposing genes, thus leading to a lipid accumulation in respiratory epithelial cells. Meanwhile, the imbalance of lipid metabolism in respiratory epithelial cells induced by 1-BP further caused mitochondrial damage, and the effect was bidirectional. These findings suggested that 1-BP has a potential role in inducing respiratory epithelial cell damage and is associated with the PGC-1α/PPARα signaling pathway.

Lycopene Inhibits Postoperative Abdominal Adhesion Formation in a Mouse Model

INTRODUCTION

The prevention of postoperative abdominal adhesions is one of the top concerns of surgeons after abdominal surgery. Therefore, identifying effective interventions to reduce postoperative abdominal adhesions are essential.

METHODS

Fifty male Bagg's albino/c mice were randomly divided into five groups, and all groups underwent postoperative adhesion model surgery, except for the sham group. The sham and control groups were gavaged with saline solution. Based on the control group, the sodium hyaluronate group was treated with 1 mL sodium hyaluronate (smeared on the modeling site and the abdominal cavity was closed). The other two groups were gavaged with different doses of lycopene (10 μg/kg and 20 μg/kg). Seven d after surgery, the mice were sacrificed and adhesion conditions were assessed using Nair's scoring system. Subsequently, adherent tissues were harvested and the inflammation was assessed by using haematoxylin and eosin staining and enzyme linked immunosorbent assay for interleukin-6 and transforming growth factor-β1. Oxidative stress and collagen deposition condition were also detected in each mouse. Furthermore, a lycopene-induced HMrSV5 cell model was used to explore the possible functional mechanisms.

RESULTS

20 μg/kg of lycopene-treated group had a lower Nair's and inflammation score, both with an average score of 1.75. Also, the level of transforming growth factor -β1 and interleukin-6 in the 20 μg/kg of lycopene-treated group was lower than others. Furthermore, 20 μg/kg of lycopene had reduced the reactive oxygen species and malondialdehyde levels in adhesion tissues compared to other groups. Fiber thickness and α-smooth muscle actin expression in adherent tissues were significantly reduced after lycopene treatment. Besides, 20 μg/kg of lycopene treatment can promote the expression of nuclear factor erythroid 2-related factor 2 and silent information regulator 1. In in-vitro studies, lycopene protected mesothelial cells from H2O2 -induced oxidative stress injury.

CONCLUSIONS

Lycopene can attenuate abdominal adhesion in the mouse model by reducing inflammation and oxidative stress, and the possible mechanism may rely on promoting the expression of nuclear factor erythroid 2-related factor 2 and silent information regulator 1.

Therapeutic potential of monoterpene molecules acts against 7KCh-mediated oxidative stress and neuroinflammatory amyloidogenic signalling pathways

Alzheimer's disease (AD) is a degenerative disorder characterised by amyloid-beta aggregates activated by the accumulation of lipid molecules and their derivatives, especially 7-ketocholesterol (7KCh), an oxidised lipid that plays a great part in the progression of AD. The current therapeutics need bio-potential molecules and their biomedical application preventing 7KCh-induced cytotoxicity. In this study, bornyl acetate (BA) and menthol (ME), the natural monoterpenes were investigated for their neuroprotective effects against 7KCh-induced SH-SY5Y cells and their effects were compared to the standard drug galantamine (GA). 7KCh-induced changes like lipid accumulation, amyloid generation, free radical generation, acetylcholinesterase levels, calcium accumulation and mitochondrial membrane integrity were analysed in SH-SY5Y cells with or without BA and ME treatment. Furthermore, various mediators involved in the amyloidogenic, inflammatory and apoptotic pathways were studied. In our results, the cells induced with 7KCh upon co-treatment with BA and ME significantly reduced lipid accumulation and amyloid generation through toll-like receptor (TLR) 4 suppression and enhanced ATP binding cassette (ABCA) 1-mediated clearance. Co-treatment with BA and ME concurrently regulated oxidative stress, acetylcholinesterase activity, mitochondrial membrane potential and intracellular calcification altered by 7KCh-induced SH-SY5Y cells. Moreover, 7KCh-induced cells showed elevated mRNA levels of misfolded protein markers and apoptotic mediators which were significantly downregulated by BA and ME co-treatment. In addition, the protein expression of amyloidogenic, proinflammatory as well as pro-apoptotic markers was decreased by BA and ME co-treatment in 7KCh-induced cells. Overall, BA and ME mediated inhibition of amyloidogenic activation and cell survival against 7KCh-induced inflammation, thereby preventing the onset and progression of AD in comparison to GA.

ATP functions as a primary alarmin in allergen-induced type 2 immunity

Environmental allergens that interact with the airway epithelium can activate cellular stress pathways that lead to the release of danger signals known as alarmins. The mechanisms of alarmin release are distinct from damage-associated molecular patterns (DAMPs), which typically escape from cells after loss of plasma membrane integrity. Oxidative stress represents a form of allergen-induced cellular stress that stimulates oxidant-sensing mechanisms coupled to pathways, which facilitate alarmin mobilization and efflux across the plasma membrane. In this review, we highlight examples of alarmin release and discuss their roles in the initiation of type 2 immunity and allergic airway inflammation. In addition, we discuss the concept of alarmin amplification, where "primary" alarmins, which are directly released in response to a specific cellular stress, stimulate additional signaling pathways that lead to secretion of "secondary" alarmins that include proinflammatory cytokines, such as IL-33, as well as genomic and mitochondrial DNA that coordinate or amplify type 2 immunity. Accordingly, allergen-evoked cellular stress can elicit a hierarchy of alarmin signaling responses from the airway epithelium that trigger local innate immune reactions, impact adaptive immunity, and exacerbate diseases including asthma and other chronic inflammatory conditions that affect airway function.

Uptake of Nanoplastic particles by zebrafish embryos triggers the macrophage response at early developmental stage

Plastic pollution continues to erupt as a global ecological concern. As plastic debris is degraded into nanoscale and microscale particles via biodegradation, UV-irradiation, and mechanical processes, nanoplastic pollution arises as a threat to virtually every biological and ecological system on the planet. In this study, zebrafish (Danio rerio) embryos were exposed to fluorescently labeled plastic particles at nanoscales (30 nm and 100 nm). The uptake of both the nanoplastic particles (NPs) was found to exponentially increase with incubation time. Penetration of NPs through the natural barrier of the zebrafish embryos, the chorion, was observed prior to the hatching of the embryo. As a result, the NPs were found to accumulate on the body surface as well as inside the body of the zebrafish. The invasion of NPs into zebrafish embryos induced the upregulation of several stress and immune response genes including interleukins (il6 and il1b), cytochrome P450 (cyp1a and cyp51), and reactive oxygen species (ROS) removal protein-encoding genes (sod and cat). This suggested the initiation of ROS generation and removal as well as the activation of the immune response of zebrafish embryos. Colocalization of macrophages and NPs in zebrafish embryos indicated the involvement of macrophage response to the NP invasion at the early developmental stage of zebrafish.

Higher House Dust Mite-Specific IgE Levels among Chronic Spontaneous Urticaria Patients May Implicate Higher Basophil Reactivity

INTRODUCTION

Allergen-specific IgE (sIgE) sensitization exists in a considerable fraction of chronic spontaneous urticaria (CSU) patients. Basophils have been implicated in the pathogenesis of CSU. This paper aimed to explore the relationship between allergic sensitization and basophil reactivity in CSU and the possible underlying mechanism.

METHODS

Basophil-enriched leukocytes were isolated from the peripheral blood of 76 CSU patients and 9 healthy controls. Basophil CD63 and FcεRIα (the alpha subunit of the high-affinity IgE receptor) expression in the blood samples with various house dust mite (HDM)-sIgE levels were determined by flow cytometry. Basophil reactivity and SHIP-1 (a molecule related to the IgE/FcεRI signaling pathway) expression were analyzed after stimulation with an HDM allergen or other stimuli.

RESULTS

HDM-sIgEstrong positive (≥3.5 kU/L) CSU patients had a significantly higher mean percentage of basophil CD63 and higher baseline levels of FcεRIα expressed by basophils than HDM-sIgEnormal (<0.35 kU/L) CSU patients and healthy controls; the same went for total serum IgE. After stimulation with Dermatophagoides pteronyssinus peptidase 1 (Derp1) alone or together with Derp1-sIgE, the stimulation index of CD63 and levels of FcεRIα expressed by basophils in HDM-sIgEstrong positive CSU patients were significantly higher than those in HDM-sIgEnormal CSU patients and healthy controls. Significantly more SHIP-1 mRNA expression in HDM-sIgEstrong positive CSU patients was induced after the combined stimulation in comparison to other subjects.

CONCLUSION

CSU patients with higher HDM-sIgE levels (≥3.5 kU/L) may have higher CD63 and FcεRIα expression on peripheral blood basophils. Peripheral blood basophils in these CSU patients are more responsive to HDM allergen stimulation. Higher HDM-sIgE levels among CSU patients may implicate higher basophil reactivity.

Preventive Mechanism of Lycopene on Intestinal Toxicity Caused by Cyclophosphamide Chemotherapy in Mice by Regulating TLR4-MyD88/TRIF-TRAF6 Signaling Pathway and Gut-Liver Axis

Cyclophosphamide (CYC) is the first-line chemotherapy drug for cancer in clinical practice, and its intestinal toxicity seriously affects the treatment effect and prognosis of patients. Lycopene (LP) is the main pigment of ripe tomatoes and has strong antioxidant activity. However, the mechanism by which LP prevents CYC-induced intestinal injury remains unclear. The aim of this study was to investigate the mechanism of LP in preventing intestinal toxicity caused by CYC chemotherapy in mice. The results showed that LP significantly prevented spleen and thymus atrophy induced by CYC. In terms of intestinal injury, LP significantly increased the levels of superoxide dismutase (SOD), secretory immunoglobulin A (sIgA), interleukin (IL)-4, IL-12, and interferon (IFN)-γ, decreased the content of lipid oxidation (MDA), upregulated the protein expressions of toll-like receptors 4 (TLR4), myeloid differentiation factor 88 (MyD88), tumor necrosis factor receptor-associated factor 6 (TRAF6), toll/IL-1receptor domain containing adaptor protein inducing IFN-β (TRIF), p-P38 MAPK (P38), and p-nuclear factor kappa-B (NF-κB) p65, and improved the small intestine tissue injury induced by CYC. In terms of liver injury, LP significantly increased the content of glutathione (GSH), decreased the contents of MDA, nitric oxide (NO), IL-1β, IL-6, and tumor necrosis factor (TNF)-α, and repaired the liver tissue injury induced by CYC. Importantly, 10 mg/kg LP significantly prevented intestinal microbiota dysregulation in CYC mice. These results suggested that LP significantly prevented intestinal injury induced by CYC in mice by regulating the TLR4-MyD88/TRIF-TRAF6 signaling pathway and gut-liver axis.

α‑lipoic acid inhibits cerulein/resistin‑induced expression of interleukin‑6 by activating peroxisome proliferator‑activated receptor‑γ in pancreatic acinar cells

Cerulein‑induced pancreatitis resembles human acute pancreatitis in terms of pathological events, such as enzymatic activation and inflammatory cell infiltration in the pancreas. Cerulein is a cholecystokinin analog that increases levels of reactive oxygen species (ROS) and interleukin‑6 (IL‑6) expression level in pancreatic acinar cells. Serum levels of resistin, which is secreted from adipocytes, are reportedly higher in patients with acute pancreatitis than in healthy individuals. Previously, it was shown that the adipokine resistin can aggravate the cerulein‑induced increase in ROS levels and IL‑6 expression level in pancreatic acinar cells. Peroxisome proliferator‑activated receptor‑gamma (PPAR‑γ) is a key regulator of the transcription and expression of antioxidant enzymes, including heme oxygenase 1 (HO‑1) and catalase. α‑lipoic acid, a naturally occurring dithiol antioxidant, can prevent cerulein‑induced pancreatic damage in rats. In the present study, it was aimed to investigate whether α‑lipoic acid can attenuate the cerulein/resistin‑induced increase in IL‑6 expression and ROS levels via PPAR‑γ activation in pancreatic acinar AR42J cells. The anti‑inflammatory mechanism of α‑lipoic acid was determined using reverse transcription‑quantitative PCR, western blot analysis, enzyme‑linked immunosorbent assay, immunofluorescence staining and fluorometry. Treatment with cerulein and resistin increased ROS levels and IL‑6 expression level, which were inhibited by α‑lipoic acid in pancreatic acinar cells. α‑lipoic acid increased the nuclear translocation and expression level of PPAR‑γ and the expression levels of its target genes: HO‑1 and catalase. The PPAR‑γ antagonist GW9662 and HO‑1 inhibitor zinc protoporphyrin reversed the inhibitory effect of α‑lipoic acid on cerulein/resistin‑induced increase in ROS and IL‑6 levels. In conclusion, α‑lipoic acid inhibits the cerulein/resistin‑induced increase in ROS production and IL‑6 expression levels by activating PPAR‑γ and inducing the expression of HO‑1 and catalase in pancreatic acinar cells.