NOX enzymes and pulmonary disease

Scutellarein Suppresses the Production of ROS and Inflammatory Mediators of LPS-Activated Bronchial Epithelial Cells and Attenuates Acute Lung Injury in Mice

Scutellarein is a key active constituent present in many plants, especially in Scutellaria baicalensis Georgi and Erigeron breviscapus (vant.) Hand-Mazz which possesses both anti-inflammatory and anti-oxidative activities. It also is the metabolite of scutellarin, with the ability to relieve LPS-induced acute lung injury (ALI), strongly suggesting that scutellarein could suppress respiratory inflammation. The present study aimed to investigate the effects of scutellarein on lung inflammation by using LPS-activated BEAS-2B cells (a human bronchial epithelial cell line) and LPS-induced ALI mice. The results showed that scutellarein could reduce intracellular reactive oxygen species (ROS) accumulation through inhibiting the activation of NADPH oxidases, markedly downregulating the transcription and translation of pro-inflammatory cytokines, including interleukin-6 (IL-6), C-C motif chemokine ligand 2 (CCL2), and C-X-C motif chemokine ligand (CXCL) 8 in LPS-activated BEAS-2B cells. The mechanism study revealed that it suppressed the phosphorylation and degradation of IκBα, consequently hindering the translocation of p65 from the cytoplasm to the nucleus and its subsequent binding to DNA, thereby decreasing NF-κB-regulated gene transcription. Notably, scutellarein had no impact on the activation of AP-1 signaling. In LPS-induced ALI mice, scutellarein significantly decreased IL-6, CCL2, and tumor necrosis factor-α (TNF-α) levels in the bronchoalveolar lavage fluid, attenuated lung injury, and inhibited neutrophil infiltration. Our findings suggest that scutellarein may be a beneficial agent for the treatment of infectious pneumonia by virtue of its anti-oxidative and anti-inflammatory activities.

Porphyromonas gingivalis triggers inflammation in hepatocyte depend on ferroptosis via activating the NF-κB signaling pathway

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterized by excessive fat deposition in hepatocytes caused by non-alcoholic liver injury. Porphyromonas gingivalis (P.g) is the main pathogen causing periodontitis, which can aggravate the progression of NAFLD in our previously study. The objective of this study was to further investigate the pathogenesis and moleculer michanisma of NAFLD aggravated by P.g.

METHODS

A mouse model of NAFLD was established, and the changes of inflammatory factors and NF-κB signaling pathway in liver tissue and L-02 cells were analyzed by transcriptome sequencing, Western blot, IHC and RT-PCR. In addition, the NF-κB signaling pathway inhibitor QNZ and ferroptosis inhibitor Fer-1 were used to analyze the relationship between NF-κB signaling pathway and ferroptosis in vitro.

RESULTS

In vivo and in vitro experiments, P.g can induce liver inflammation and activate NF-κB signaling pathway. At the same time, P.g promotes ferroptosis and inflammation in L-02 in vitro. QNZ alleviates ferroptosis and inflammatory activation in L-02. Fer-1 can relieve the L-02 inflammation caused by P.g products.

CONCLUSION

Porphyromonas gingivalis can induce ferroptosis and inflammation in hepatocytes and further worsen liver lesions. The mechanism of ferroptosis in hepatocytes depends on NF-κB signaling pathway, which provides a new strategy for clinical treatment and prevention of NAFLD.

TEMPO-conjugated tobacco mosaic virus as a magnetic resonance imaging contrast agent for detection of superoxide production in the inflamed liver

Superoxide, an anionic dioxygen molecule, plays a crucial role in redox regulation within the body but is implicated in various pathological conditions when produced excessively. Efforts to develop superoxide detection strategies have led to the exploration of organic-based contrast agents for magnetic resonance imaging (MRI). This study compares the effectiveness of two such agents, nTMV-TEMPO and kTMV-TEMPO, for detecting superoxide in a mouse liver model with lipopolysaccharide (LPS)-induced inflammation. The study demonstrates that kTMV-TEMPO, with a strategically positioned lysine residue for TEMPO attachment, outperforms nTMV-TEMPO as an MRI contrast agent. The enhanced sensitivity of kTMV-TEMPO is attributed to its more exposed TEMPO attachment site, facilitating stronger interactions with water protons and superoxide radicals. EPR kinetics experiments confirm kTMV-TEMPO's faster oxidation and reduction rates, making it a promising sensor for superoxide in inflamed liver tissue. In vivo experiments using healthy and LPS-induced inflamed mice reveal that reduced kTMV-TEMPO remains MRI-inactive in healthy mice but becomes MRI-active in inflamed livers. The contrast enhancement in inflamed livers is substantial, validating the potential of kTMV-TEMPO for detecting superoxide in vivo. This research underscores the importance of optimizing contrast agents for in vivo imaging applications. The enhanced sensitivity and biocompatibility of kTMV-TEMPO make it a promising candidate for further studies in the realm of medical imaging, particularly in the context of monitoring oxidative stress-related diseases.

The Impressive Anti-Inflammatory Activity of Cerium Oxide Nanoparticles: More than Redox?

Cerium oxide nanoparticles (CNPs) are biocompatible nanozymes exerting multifunctional biomimetic activities, including superoxide dismutase (SOD), catalase, glutathione peroxidase, photolyase, and phosphatase. SOD- and catalase-mimesis depend on Ce3+/Ce4+ redox switch on nanoparticle surface, which allows scavenging the most noxious reactive oxygen species in a self-regenerating, energy-free manner. As oxidative stress plays pivotal roles in the pathogenesis of inflammatory disorders, CNPs have recently attracted attention as potential anti-inflammatory agents. A careful survey of the literature reveals that CNPs, alone or as constituents of implants and scaffolds, strongly contrast chronic inflammation (including neurodegenerative and autoimmune diseases, liver steatosis, gastrointestinal disorders), infections, and trauma, thereby ameliorating/restoring organ function. By general consensus, CNPs inhibit inflammation cues while boosting the pro-resolving anti-inflammatory signaling pathways. The mechanism of CNPs' anti-inflammatory effects has hardly been investigated, being rather deductively attributed to CNP-induced ROS scavenging. However, CNPs are multi-functional nanozymes that exert additional bioactivities independent from the Ce3+/Ce4+ redox switch, such as phosphatase activity, which could conceivably mediate some of the anti-inflammatory effects reported, suggesting that CNPs fight inflammation via pleiotropic actions. Since CNP anti-inflammatory activity is potentially a pharmacological breakthrough, it is important to precisely attribute the described effects to one or another of their nanozyme functions, thus achieving therapeutic credibility.

Asymmetric synthesis of chiral (thio)chromanes and exploration on their structure-activity relationship in macrophages

A CuCl/(R,R)-Ph-BPE-catalyzed enantioselective hydroallylation of 2H-chromenes and 2H-thiochromenes with allylic phosphate electrophiles is developed, which enables highly efficient and atom-economical asymmetric access to a series of 4-allyl chromanes and thiochromanes in high yields (up to 91%) with excellent enantioselectivities (up to 99% ee). These valuable chiral chromane and thiochromane products can serve as crucial intermediates for accessing bioactive compounds containing oxygen and sulfur atoms. In addition, the antioxidant and anti-inflammatory effects of various chromanes and thiochromanes were investigated in RAW 264.7 macrophages. The chromanes and thiochromanes exhibited significant inhibitory effects on the production of reactive oxygen species (ROS) and the secretion of pro-inflammatory cytokines, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). These findings indicate that the newly synthesized chromanes and thiochromanes hold promise as potential lead compounds for the development of antioxidant and anti-inflammatory drugs.

The NADPH Oxidase Inhibitors Apocynin and Diphenyleneiodonium Protect Rats from LPS-Induced Pulmonary Inflammation

Inflammation is the body's response to insults, for instance, lung inflammation is generally caused by pathogens or by exposure to pollutants, irritants and toxins. This process involves many inflammatory cells such as epithelial cells, monocytes, macrophages and neutrophils. These cells produce and release inflammatory mediators such as pro-inflammatory cytokines, lipids and reactive oxygen species (ROS). Lung epithelial cells and phagocytes (monocytes, macrophages and neutrophils) produce ROS mainly by the NADPH oxidase NOX1 and NOX2, respectively. The aim of this study was to investigate the effects of two NADPH oxidase inhibitors, apocynin and diphenyleneiodonium (DPI), on lipopolysaccharide (LPS)-induced lung inflammation in rats. Our results showed that apocynin and DPI attenuated the LPS-induced morphological and histological alterations of the lung, reduced edema and decreased lung permeability. The evaluation of oxidative stress markers in lung homogenates showed that apocynin and DPI inhibited LPS-induced NADPH oxidase activity, and restored superoxide dismutase (SOD) and catalase activity in the lung resulting in the reduction in LPS-induced protein and lipid oxidation. Additionally, apocynin and DPI decreased LPS-induced MPO activity in bronchoalveolar liquid and lung homogenates, TNF-α and IL-1β in rat plasma. NADPH oxidase inhibition could be a new therapeutic strategy for the treatment of inflammatory lung diseases.

Morpho-functional changes of lungfish Protopterus dolloi skin in the shift from freshwater to aestivating conditions

African dipnoi (Protopterus sp.) are obligate air-breathing fish that, during dry season, may experience a period of dormancy named aestivation. Aestivation is characterized by complete reliance on pulmonary breathing, general decrease of metabolism and down-regulation of respiratory and cardiovascular functions. To date, little is known about morpho-functional rearrangements induced by aestivation in the skin of African lungfishes. Our study aims to identify, in the skin of P. dolloi, structural modifications and stress-induced molecules in response to short-term (6 days) and long-term (40 days) aestivation. Light microscopy showed that short-term aestivation induces major reorganization, with narrowing of epidermal layers and decrease of mucous cells; prolonged aestivation is characterized by regenerative processes and re-thickening of epidermal layers. Immunofluorescence reveals that aestivation correlates with an increased oxidative stress and changes of Heat Shock Proteins expression, suggesting a protective role for these chaperons. Our findings revealed that lungfish skin undergoes remarkable morphological and biochemical readjustments in response to stressful conditions associated with aestivation.

Novel studies on Drosophila melanogaster model reveal the roles of JNK-Jak/STAT axis and intestinal microbiota in insulin resistance

The JNK pathway play a critical role in insulin resistance induced by a long-term high-sugar diet. However, the roles of up- and downstream molecules of the JNK pathway in insulin resistance are less known in vertebrates and invertebrates. As a classical organism in biological research, Drosophila melanogaster (D. melanogaster) has been widely applied to the studies of mechanism of insulin resistance. Based on previous studies, we found a novel predictive mechanism of the formation of insulin resistance in D. melanogaster. We found that JNK activated by high-sugar diet and dysregulated intestinal microbiota could mediate inflammation, and then the activated JNK released Upd3, which in turn stimulated Jak/STAT pathway to release ImpL2. ImpL2 can compete with Drosophila insulin-like peptides (Dilps) for binding with the insulin receptor and inhibit the activation of insulin pathway. In this study, we reviewed novel studies on the insulin signalling pathway based on the D. melanogaster model. The findings support our hypothesis. We, therefore, described how a long-term high-sugar diet disrupts intestinal microbiota to induce inflammation and the disruption of JNK-Jak/STAT axis. This description may offer some new clues to the formation of insulin resistance.

Bone matrix quality in a developing high-fat diet mouse model is altered by RAGE deletion

Overweightness and obesity in adolescents are epidemics linked to chronic low-grade inflammation and elevated fracture risk. The increased fracture risk observed in overweight/obese adolescence contrasts the traditional concept that high body mass is protective against fracture, and thus highlights the need to determine why weight gain becomes detrimental to fracture during growth and maturity. The Receptor for Advanced Glycation End products (RAGE) is a central inflammatory regulator that can influence bone metabolism. It remains unknown how RAGE removal impacts skeletal fragility in overweightness/obesity, and whether increased fracture risk in adolescents could result from low-grade inflammation deteriorating bone quality. We characterized the multiscale structural, mechanical, and chemical properties of tibiae extracted from adolescent C57BL/6J (WT) and RAGE null (KO) mice fed either low-fat (LF) or high-fat (HF) diet for 12 weeks starting at 6 weeks of age using micro-computed tomography, strength, Raman spectroscopy, and nanoindentation. Overweight/obese WT HF mice possessed degraded mineral-crystal quality and increased matrix glycoxidation in the form of pentosidine and carboxymethyl-lysine, with HF diet in females only showing reduced cortical surface expansion and TMD independently of RAGE ablation. Furthermore, in contrast to males, HF diet in females led to more material damage and plastic deformation. RAGE KO mitigated glycoxidative matrix accumulation, preserved mineral quantity, and led to increased E/H ratio in females. Taken together, these results highlight the complex, multi-scale and sex-dependent relationships between bone quality and function under overweightness, and identifies RAGE-controlled glycoxidation as a target to potentially preserve matrix quality and mechanical integrity.

α-Iso-cubebene attenuates neointima formation by inhibiting HMGB1-induced monocyte to macrophage differentiation via suppressing ROS production

α-Iso-cubebene (ICB) is a dibenzocyclooctadiene lignin contained in Schisandra chinensis, a medicinal herb used to improve cardiovascular symptoms. To investigate the mechanisms involved, the effects of ICB on cellular production of reactive oxygen species (ROS) was determined using cultured human THP-1 cells. When THP-1 cells were stimulated with HMGB1, cellular concentration of ROS was increased in dose- and time-dependent manners. These increases were significantly attenuated in cells pretreated with NADPH oxidase inhibitors, diphenyleneiodonium chloride and apocynin, but not by other inhibitors related to ROS generation in monocytes. The expression of constitutively expressed NADPH oxidase (NOX) subunits including NOX1, NOX2, NOX4 and NOX5 was not affected by HMGB1, but HMGB1-induced ROS production was exclusively attenuated in NOX2-deficient cells using siRNA, suggesting an enhanced NOX2 complex assembly. When cells were stimulated with HMGB1, p47phox phosphorylation at ser345, ser359 and ser370 was increased in dose- and time-dependent manners, which were significantly attenuated in ICB (3-10 μg/mL)-pretreated cells. In addition, HMGB1-induced monocyte-macrophage differentiation (MMD) in bone marrow-derived cells isolated from mice were significantly attenuated in cells treated with apocynin and ICB. Also, macrophage infiltration and intimal hyperplasia in the wire-injured femoral artery were significantly attenuated in ICB-treated mice compared to wild-type control mice. The results of this study show that ICB inhibits HMGB1-induced MMD by suppressing ROS production in monocytes, thus suggest that ICB has therapeutic potential for vascular inflammation with subsequent intimal hyperplasia related to vascular injury.

Redox signaling at the crossroads of human health and disease

Redox biology is at the core of life sciences, accompanied by the close correlation of redox processes with biological activities. Redox homeostasis is a prerequisite for human health, in which the physiological levels of nonradical reactive oxygen species (ROS) function as the primary second messengers to modulate physiological redox signaling by orchestrating multiple redox sensors. However, excessive ROS accumulation, termed oxidative stress (OS), leads to biomolecule damage and subsequent occurrence of various diseases such as type 2 diabetes, atherosclerosis, and cancer. Herein, starting with the evolution of redox biology, we reveal the roles of ROS as multifaceted physiological modulators to mediate redox signaling and sustain redox homeostasis. In addition, we also emphasize the detailed OS mechanisms involved in the initiation and development of several important diseases. ROS as a double‐edged sword in disease progression suggest two different therapeutic strategies to treat redox‐relevant diseases, in which targeting ROS sources and redox‐related effectors to manipulate redox homeostasis will largely promote precision medicine. Therefore, a comprehensive understanding of the redox signaling networks under physiological and pathological conditions will facilitate the development of redox medicine and benefit patients with redox‐relevant diseases.

Ovarian Oxidative Stress Induced Follicle Depletion After Zona Pellucida 3 Vaccination Is Associated With Subfertility in BALB/c Mice

Impaired follicular development associated with autoimmune ovarian disease (AOD), is a typical side effect of ZP3 vaccine-induced subfertility and contributes to the fertility decline, but the mechanism is unknown. In this study, a AOD model was established with recombinant mouse zona pellucida 3 (mZP3) protein in the BALB/c mice, and co-administrated with 0.5 mg/kg antioxidant stress drug sodium selenite (SS), whereas intraperitoneal injection was used and the relationships among oxidant stress (OS), follicle loss and fertility were evaluated. Here we demonstrated that ZP3 vaccination elicited high antibody titers and correlated with reductions of ovarian follicle numbers in both fertile and infertile mice, whereby magnitudes of both factors were negatively correlated with litter size. Moreover, increased OS in ovaries of mZP3-immunized mice was related to high levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and is accompanied by a decrease in the total antioxidant capacity (TAC) of ovaries. Meanwhile, activation of caspase-3 and caspase-9 along with increased Bax and decreased Bcl-2 levels were observed, indicating the ongoing apoptosis of ovarian cells. Notably, inhibition of OS with SS reduced ovarian ROS and apoptosis levels, which was consisted with restoration of follicle numbers. More importantly, SS treatment when co-administered concurrently with mZP3 immunization led to significantly improved fertility (P < 0.05) and the average litter size of the mZP3-vaccinated SS-treated group increased by ~29.2% as compared with that of the vaccinated but untreated group. In conclusion, infertility caused by ZP3 vaccination was mechanistically associated with ovarian OS which triggered depletion of ovarian follicles.

NR4A1 promotes oxidative stresses after myocardial ischemia reperfusion injury in aged mice

Myocardial infarction (MI) is a serious disease which is responsible for major death in the elderly. Myocardial oxidative stress contributes to pathophysiology of MI. The nuclear receptor subfamily 4 group A member 1 (NR4A1) has been shown to regulate oxidative stress in several diseases. However, the precise roles of NR4A1 in MI-induced oxidative stress in elderly remain unknown. In present study, the effects of NR4A1 deficiency on oxidative stress were evaluated in aged MI mice. A MI aged mice model was established in wide-type (WT) and NR4A1 deficient mice. The expression of NR4A1, oxidative stress markers was measured. The myocardial functions were monitored. NR4A1 was upregulated in aged MI WT mice, which was positively correlated to the elevated oxidative stress. NR4A1 deficient MI mice had significantly decreased expression of oxidative stress markers malondialdehyde and hydrogen peroxide while had improved myocardial function. In summary, NR4A1 deficiency could attenuate oxidative stress in aged MI mice.

Cadmium and Cadmium/BDE (47 or 209) Exposure Affect Mitochondrial Function, DNA Damage/Repair Mechanisms and Barrier Integrity in Airway Epithelial Cells

Heavy metals and Brominated diphenyl ether flame-retardants (BDEs) often coexist in the environment and are capable of inducing injury, cytotoxicity or genotoxicity in human epithelial cells of the lung. We studied the effects of single Cadmium chloride (CdCl2) or CdCl2/BDE (47 or 209) mixtures in airway epithelial cells, using A549 cell line cultured at submerged conditions and air–liquid interface (ALI) (an in vitro model described as physiologically relevant in vivo-like). We evaluated cell viability, oxidative stress, apoptosis, DNA damage/repair (Comet assay, γH2AX phosphorylation ser139), mitochondrial redox balance (NOX-4, Nrf2 and TFAM) and cell barrier integrity (TEER, ZO-1, Claudin-1, E-cadherin-1) in A549 cells exposed to CdCl2 (1 nM to 10 µM), or to CdCl2 (100 nM)/BDEs (47 or 209) (100 nM). CdCl2 (10 μM) reduced cell viability and increased apoptosis. CdCl2 (100 nM) significantly affected DNA-damage/repair (Olive Tail length production), γH2AX phosphorylation and oxidative stress (ROS/JC-1 production) in submerged cell cultures. CdCl2 (100 nM) decreased viability, TEER, ZO-1, Claudin-1 and E-cadherin-1 mRNA expression, and Nrf2 and TFAM while increased NOX-4, in ALI culture of cells. In both cell culture approaches, the cells stimulated with Cadmium/BDEs mixtures did not show a significant increase in the effects observed in the cells treated with CdCl2 alone. CdCl2 inhalation might exert cytotoxicity and genotoxicity, playing a pivotal role in the uncontrolled oxidative stress, damaging DNA and gene expression in airway epithelial cells. No additional or synergistic adverse effects of CdCl2/BDEs mixture were observed in comparison to CdCl2 alone in lung epithelium.

Targeting Oxidative Stress as a Therapeutic Approach for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease characterized by an abnormal reepithelialisation, an excessive tissue remodelling and a progressive fibrosis within the alveolar wall that are not due to infection or cancer. Oxidative stress has been proposed as a key molecular process in pulmonary fibrosis development and different components of the redox system are altered in the cellular actors participating in lung fibrosis. To this respect, several activators of the antioxidant machinery and inhibitors of the oxidant species and pathways have been assayed in preclinical in vitro and in vivo models and in different clinical trials. This review discusses the role of oxidative stress in the development and progression of IPF and its underlying mechanisms as well as the evidence of oxidative stress in human IPF. Finally, we analyze the mechanism of action, the efficacy and the current status of different drugs developed to inhibit the oxidative stress as anti-fibrotic therapy in IPF.

Quercetin Prevents LPS-Induced Oxidative Stress and Inflammation by Modulating NOX2/ROS/NF-kB in Lung Epithelial Cells

Oxidative stress caused by the production of reactive oxygen species (ROS) plays a major role in inflammatory processes. We hypothesized that modulation of ROS via quercetin may protect against oxidative stress and inflammation. Thus, this study aimed to investigate the effects of quercetin on oxidative stress and inflammation in lung epithelial A549 cells. The lipopolysaccharide (LPS)-induced elevation of intracellular ROS levels was reduced after quercetin treatment, which also almost completely abolished the mRNA and protein expression of nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) induced by LPS stimulation. In addition, quercetin suppressed the nuclear translocation of nuclear factor kappa B (NF-κB) and reduced levels of inflammatory cytokine tumor necrosis factor (TNF)-α, interleukin (IL)-1, and IL-6, which had increased significantly after LPS exposure. Our data demonstrated that quercetin decreased ROS-induced oxidative stress and inflammation by suppressing NOX2 production.

Tear Levels of Inflammatory Cytokines in Keratoconus: A Meta-Analysis of Case-Control and Cross-Sectional Studies

Purpose

To assess the tear levels of inflammatory cytokines in patients with keratoconus (KC).

Design

Systemic review and meta-analysis.

Methods

The following electronic databases and search engine were searched: PubMed, EMBASE, Web of Science, and Google Scholar. A systematic search of all relevant studies published through January 2021 was conducted, and the standardized mean difference (SMD) and 95% confidence interval (CI) of cytokine levels were calculated to estimate the pooled effects. Sensitivity analysis, subgroup analysis, and metaregression were applied to explore the sources of heterogeneity.

Results

A total of 7 studies with 374 participants (374 eyes) from clinical studies were included. The tear levels of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) were significantly increased in KC compared with normal controls. The SMD of IL-1β was 1.93 (95% CI 0.22 to 3.65, P = 0.03). The SMD of IL-6 was 1.22 (95% CI 0.59 to 1.84, P < 0.001). The SMD of TNF-α was 1.75 (95% CI 0.66 to 2.83, P = 0.002). There was no significant difference between the two groups on interleukin-4 (IL-4) and interleukin-10 (IL-10). The SMD for IL-4 was 2.36 (95% CI -0.28 to 5.00, P = 0.08) and for IL-10 was 0.30 (95% CI -1.29 to 1.89, P = 0.71). Meta-regression analysis indicated that the heterogeneity maybe significantly correlated with the method of detection, the different ages, and the source of population.

Conclusions

Our meta-analysis demonstrated that proinflammatory cytokines IL-1β, IL-6, and TNF-α were increased, indicating that cytokine profile changed in KC tears and inflammation may play an important role in the pathogenesis and development of KC.

NAD+ improves cognitive function and reduces neuroinflammation by ameliorating mitochondrial damage and decreasing ROS production in chronic cerebral hypoperfusion models through Sirt1/PGC-1α pathway

Background

Microglial-mediated neuroinflammation plays an important role in vascular dementia, and modulating neuroinflammation has emerged as a promising treatment target. Nicotinamide adenine dinucleotide (NAD⁺) shows anti-inflammatory and anti-oxidant effects in many neurodegenerative disease models, but its role in the chronic cerebral hypoperfusion (CCH) is still unclear.

Methods

The bilateral common carotid artery occlusion (BCCAO) was performed to establish CCH models in Sprague-Dawley rats. The rats were given daily intraperitoneal injection of NAD⁺ for 8 weeks. The behavioral test and markers for neuronal death and neuroinflammation were analyzed. Mitochondrial damage and ROS production in microglia were also assessed. RNA-seq was performed to investigate the mechanistic pathway changes. For in vitro studies, Sirt1 was overexpressed in BV2 microglial cells to compare with NAD⁺ treatment effects on mitochondrial injury and neuroinflammation.

Results

NAD⁺ administration rescued cognitive deficits and inhibited neuroinflammation by protecting mitochondria and decreasing ROS production in CCH rats. Results of mechanistic pathway analysis indicated that the detrimental effects of CCH might be associated with decreased gene expression of PPAR-γ co-activator1α (PGC-1α) and its upstream transcription factor Sirt1, while NAD⁺ treatment markedly reversed their decrease. In vitro study confirmed that NAD⁺ administration had protective effects on hypoxia-induced neuroinflammation and mitochondrial damage, as well as ROS production in BV2 microglia via Sirt1/PGC-1α pathway. Sirt1 overexpression mimicked the protective effects of NAD⁺ treatment in BV2 microglia.

Conclusions

NAD⁺ ameliorated cognitive impairment and dampened neuroinflammation in CCH models in vivo and in vitro, and these beneficial effects were associated with mitochondrial protection and ROS inhibition via activating Sirt1/PGC-1α pathway.

From Oxidative Stress to Inflammation in the Posterior Ocular Diseases: Diagnosis and Treatment

Most irreversible blindness observed with glaucoma and retina-related ocular diseases, including age-related macular degeneration and diabetic retinopathy, have their origin in the posterior segment of the eye, making their physiopathology both complex and interconnected. In addition to the age factor, these diseases share the same mechanism disorder based essentially on oxidative stress. In this context, the imbalance between the production of reactive oxygen species (ROS) mainly by mitochondria and their elimination by protective mechanisms leads to chronic inflammation. Oxidative stress and inflammation share a close pathophysiological process, appearing simultaneously and suggesting a relationship between both mechanisms. The biochemical end point of these two biological alarming systems is the release of different biomarkers that can be used in the diagnosis. Furthermore, oxidative stress, initiating in the vulnerable tissue of the posterior segment, is closely related to mitochondrial dysfunction, apoptosis, autophagy dysfunction, and inflammation, which are involved in each disease progression. In this review, we have analyzed (1) the oxidative stress and inflammatory processes in the back of the eye, (2) the importance of biomarkers, detected in systemic or ocular fluids, for the diagnosis of eye diseases based on recent studies, and (3) the treatment of posterior ocular diseases, based on long-term clinical studies.

Anti-Inflammatory Effects of Four Psilocybin-Containing Magic Mushroom Water Extracts in vitro on 15-Lipoxygenase Activity and on Lipopolysaccharide-Induced Cyclooxygenase-2 and Inflammatory Cytokines in Human U937 Macrophage Cells

Purpose

During a pathological inflammation, macrophages are activated to produce accumulation of inflammatory mediators such as induced-cyclooxygenase-2 (COX-2), 15-lipoxygenase (15-LOX) and pro-inflammatory cytokines. Pathological inflammation is a significant problem in many chronic diseases. As a result, more research into natural remedies with anti-inflammatory potential is crucial. Since ancient times, psilocybin-containing mushrooms, also known as magic mushrooms, were used for mind healing and also to advance the quality of life. However, not much is known about their anti-inflammatory potential. This study aimed at investigating the anti-inflammatory effects of four psilocybin-containing mushrooms (Panaeolus cyanescens, Psilocybe natalensis, Psilocybe cubensis and Psilocybe cubensis leucistic A+ strain) from genus Panaeolus and Psilocybe for the first time in vitro on 15-LOX activity and also on lipopolysaccharide (LPS)-induced inflammation in human U937 macrophage cells.

Methods

Mushrooms were grown and extracted with boiling hot water. Effects of the four water extracts on 15-LOX activity were determined. Confluent human U937 cells were differentiated with phorbol 12-myristate 13-acetate and treated with the hot-water extracts (25 and 50 µg/mL) 2 hours before being stimulated with 1 µg/mL LPS over 24 hours. Quercetin was used as a positive control. Control cells were differentiated but not LPS-induced nor treated. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 concentrations were measured. Levels of COX-2 and mitochondrial activity were also determined.

Results

The four water extracts had poor 15-LOX inhibition activity with IC₅₀ > 250 µg/mL. Extracts were safe at the concentration studied and inhibited the LPS-induced production of pro-inflammatory mediators, TNF-α and IL-1β significantly and lowered IL-6 and COX-2 concentrations in treated human U937 macrophage cells. Water extracts also increased percentage viability of treated cells and levels of anti-inflammatory IL-10 non-significantly.

Conclusion

The study suggested that the hot-water extracts of the four psilocybin-containing magic mushrooms have potential anti-inflammatory effects executed by down-regulating pro-inflammatory mediators.

Use of Antioxidants for the Neuro-Therapeutic Management of COVID-19

Coronavirus Disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is an emergent infectious disease that has caused millions of deaths throughout the world. COVID-19 infection's main symptoms are fever, cough, fatigue, and neurological manifestations such as headache, myalgias, anosmia, ageusia, impaired consciousness, seizures, and even neuromuscular junctions' disorders. In addition, it is known that this disease causes a series of systemic complications such as adverse respiratory distress syndrome, cardiac injury, acute kidney injury, and liver dysfunction. Due to the neurological symptoms associated with COVID-19, damage in the central nervous system has been suggested as well as the neuroinvasive potential of SARS-CoV-2. It is known that CoV infections are associated with an inflammation process related to the imbalance of the antioxidant system; cellular changes caused by oxidative stress contribute to brain tissue damage. Although anti-COVID-19 vaccines are under development, there is no specific treatment for COVID-19 and its clinical manifestations and complications; only supportive treatments with immunomodulators, anti-vascular endothelial growth factors, modulating drugs, statins, or nutritional supplements have been used. In the present work, we analyzed the potential of antioxidants as adjuvants for the treatment of COVID-19 and specifically their possible role in preventing or decreasing the neurological manifestations and neurological complications present in the disease.

Apocynin prevents cigarette smoking-induced loss of skeletal muscle mass and function in mice by preserving proteostatic signalling

Background and Purpose

Skeletal muscle dysfunction is a major comorbidity of chronic obstructive pulmonary disease (COPD). This type of muscle dysfunction may be a direct consequence of oxidative insults evoked by cigarette smoke (CS) exposure. The present study examined the effects of a potent Nox inhibitor and reactive oxygen species (ROS) scavenger, apocynin, on CS‐induced muscle dysfunction.

Experimental Approach

Male BALB/c mice were exposed to either room air (sham) or CS generated from nine cigarettes per day, 5 days a week for 8 weeks, with or without the coadministration of apocynin (5 mg·kg⁻¹, i.p.). C2C12 myotubes exposed to either hydrogen peroxide (H₂O₂) or water‐soluble cigarette smoke extract (CSE) with or without apocynin (500 nM) were used as an experimental model in vitro.

Key Results

Eight weeks of CS exposure caused muscle dysfunction in mice, reflected by 10% loss of muscle mass and 54% loss of strength of tibialis anterior which were prevented by apocynin administration. In C2C12 myotubes, direct exposure to H₂O₂ or CSE caused myofibre wasting, accompanied by ~50% loss of muscle‐derived insulin‐like growth factor (IGF)‐1 and two‐fold induction of Cybb, independent of cellular inflammation. Expression of myostatin and MAFbx, negative regulators of muscle mass, were up‐regulated under H₂O₂ but not CSE conditions. Apocynin treatment abolished CSE‐induced Cybb expression, preserving muscle‐derived IGF‐1 expression and signalling pathway downstream of mammalian target of rapamycin (mTOR), thereby preventing myofibre wasting.

Conclusion and Implications

Targeted pharmacological inhibition of Nox‐derived ROS may alleviate the lung and systemic manifestations in smokers with COPD.

Downregulation of DUOX1 function contributes to aging-related impairment of innate airway injury responses and accelerated senile emphysema

Aging is associated with a gradual loss of lung function due to increased cellular senescence, decreased regenerative capacity, and impaired innate host defense. One important aspect of innate airway epithelial host defense to nonmicrobial triggers is the secretion of alarmins such as IL-33 and activation of type 2 inflammation, which were previously found to depend on activation of the NADPH oxidase (NOX) homolog DUOX1, and redox-dependent signaling pathways that promote alarmin secretion. Here, we demonstrate that normal aging of C57BL/6J mice resulted in markedly decreased lung innate epithelial type 2 responses to exogenous triggers such as the airborne allergen Dermatophagoides pteronyssinus, which was associated with marked downregulation of DUOX1, as well as DUOX1-mediated redox-dependent signaling. DUOX1 deficiency was also found to accelerate age-related airspace enlargement and decline in lung function but did not consistently affect other features of lung aging such as senescence-associated inflammation. Intriguingly, observations of age-related DUOX1 downregulation and enhanced airspace enlargement due to DUOX1 deficiency in C57BL/6J mice, which lack a functional mitochondrial nicotinamide nucleotide transhydrogenase (NNT), were much less dramatic in C57BL/6NJ mice with normal NNT function, although the latter mice also displayed impaired innate epithelial injury responses with advancing age. Overall, our findings indicate a marked aging-dependent decline in (DUOX1-dependent) innate airway injury responses to external nonmicrobial triggers, but the impact of aging on DUOX1 downregulation and its significance for age-related senile emphysema development was variable between different C57BL6 substrains, possibly related to metabolic alterations due to differences in NNT function.

Nuclear factor-kappaB regulates the transcription of NADPH oxidase 1 in human alveolar epithelial cells

Objective

Acute lung injury (ALI) is characterized by inflammation and oxidative stress. Nuclear factor-kappaB (NF-κB) mediates the expression of various inflammation-related genes, including the NADPH oxidase family. This study aimed to identify the potential regulatory role of NF-κB on NADPH oxidases in tumor necrosis factor-α (TNF-α)-induced oxidative stress in human alveolar epithelial cells.

Methods

A549 cells were treated with TNF-α for 24 h to establish ALI cell models. RT-PCR, western blot, assessment of oxidative stress, Alibaba 2.1 online analysis, electrophoretic mobility shift assays and luciferase reporter analysis were employed to identify the potential regulatory role of NF-κB on NADPH oxidases in TNF-α-induced oxidative stress in human alveolar epithelial cells.

Results

The expression of NF-κB/p65 was notably upregulated in TNF-α-stimulated A549 cells. NF-κB knockdown by siRNA significantly inhibited the TNF-α-induced oxidative stress. Moreover, NF-κB/p65 siRNA could inhibit the activation of NOX1, NOX2 and NOX4 mRNA and protein expression in TNF-α-stimulated A549 cells. The next study demonstrated that NF-κB activated the transcription of NOX1 by binding to the -261 to -252 bp (NOX1/κB2, TAAAAATCCC) region of NOX1 promoter in TNF-α-stimulated A549 cells.

Conclusion

Our data demonstrated that NF-κB can aggravate TNF-α-induced ALI by regulating the oxidative stress response and the expression of NOX1, NOX2 and NOX4. Moreover, NF-κB could promote the NOX1 transcriptional activity via binding its promoter in TNF-α-stimulated A549 cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01464-z.

Identification and validation of redox-immune based prognostic signature for hepatocellular carcinoma

The intimate interaction between redox signaling and immunity has been widely revealed. However, the clinical application of relevant therapeutic is unavailable due to the absence of validated markers that stratify patients. Here, we identified novel biomarkers for prognosis prediction in hepatocellular carcinoma (HCC). Prognostic redox-immune-related genes for predicting overall survival (OS) of HCC were identified using datasets from TCGA, LIRI-JP, and GSE14520. LASSO Cox regression was employed to construct the signature model and generate a risk score in the TCGA cohort. The signature contained CDO1, G6PD, LDHA, GPD1L, PPARG, FABP4, CCL20, SPP1, RORC, HDAC1, STC2, HDGF, EPO, and IL18RAP. Patients in the high-risk group had a poor prognosis compared to the low-risk group. Univariate and multivariate Cox regressions identified this signature as an independent factor for predicting OS. Nomogram constructed by multiple clinical parameters showed good performance for predicting OS indicated by the c-index, the calibration curve, and AUC. GSEA showed that oxidoreductase activity and peroxisome-related metabolic pathways were enriched in the low-risk group, while glycolysis activity and hypoxia were higher in the high-risk group. Furthermore, immune profiles analysis showed that the immune score and stromal score were significantly decreased in the high-risk group in the TCGA cohort. There was a considerably lower infiltration of anti-tumor immune cells while a higher proportion of pro-tumor immune cells in silico. Immune markers were distinctly expressed between the subgroups, and redox-sensitive immunoregulatory biomarkers were at higher levels in the high-risk group. Altogether, we identified a redox-immune prognostic signature. A more severe redox perturbation-driven immunosuppressive environment in the high-risk group stratified by the signature may account for poor survival. This may provide a clue to the combined therapy targeting redox and immune in HCC.

Cellular and Molecular Processes in Pulmonary Hypertension

Pulmonary hypertension (PH) is a progressive lung disease characterized by persistent pulmonary vasoconstriction. Another well-recognized characteristic of PH is the muscularization of peripheral pulmonary arteries. This pulmonary vasoremodeling manifests in medial hypertrophy/hyperplasia of smooth muscle cells (SMCs) with possible neointimal formation. The underlying molecular processes for these two major vascular responses remain not fully understood. On the other hand, a series of very recent studies have shown that the increased reactive oxygen species (ROS) seems to be an important player in mediating pulmonary vasoconstriction and vasoremodeling, thereby leading to PH. Mitochondria are a primary site for ROS production in pulmonary artery (PA) SMCs, which subsequently activate NADPH oxidase to induce further ROS generation, i.e., ROS-induced ROS generation. ROS control the activity of multiple ion channels to induce intracellular Ca²⁺ release and extracellular Ca²⁺ influx (ROS-induced Ca²⁺ release and influx) to cause PH. ROS and Ca²⁺ signaling may synergistically trigger an inflammatory cascade to implicate in PH. Accordingly, this paper explores the important roles of ROS, Ca²⁺, and inflammatory signaling in the development of PH, including their reciprocal interactions, key molecules, and possible therapeutic targets.

Vascular dysfunction as a potential culprit of sarcopenia

Aging-related changes to biological structures such as cardiovascular and musculoskeletal systems contribute to the development of comorbid conditions including cardiovascular disease and frailty, and ultimately lead to premature death. Although, frail older adults often demonstrate both cardiovascular and musculoskeletal comorbidities, the etiology of sarcopenia, and especially the contribution of cardiovascular aging is unclear. Aging-related vascular calcification is prevalent in older adults and is a known risk factor for cardiovascular disease and death. The effect vascular calcification has on function during aging is not well understood. Emerging findings suggest vascular calcification can impact skeletal muscle perfusion, negatively affecting nutrient and oxygen delivery to skeletal muscle, ultimately accelerating muscle loss and functional decline. The present review summarizes existing evidence on the biological mechanisms linking vascular calcification with sarcopenia during aging.

COVID-19: Oxidative Preconditioning as a Potential Therapeutic Approach

This Article summarizes the likely benefits of central nervous system oxidative preconditioning in the reduction of COVID-19 based on its putative pathogenesis. The current COVID-19 outbreak caused a pandemic with millions of infected patients and death cases worldwide. The clinical features of severe acute respiratory syndrome coronavirus (SARS-CoV) was initially linked with respiratory disorders, but recent studies have reported alterations of neurological and cerebrovascular functions in COVID-19 patients. The main viral infection features are related to cell death, inflammation, and cytokine generation, which can be associated with the dysregulation of redox systems or oxidative stress. However, until now, there is no available and effective therapeutic approach. Thus, it is necessary to search for care and adequate protection against the disease, especially for susceptible and vulnerable groups. Preconditioning, a well-known antioxidative stress and anti-inflammatory approach, is protective against many neurological age-related disorders. COVID-19 severity and morbidity have been observed in elderly patients. The aim of the present study is to elucidate the possible protective role of oxidative preconditioning in aged patients at high risk of developing severe COVID-19 complications.

Aronia melanocarpa Fruit Bioactive Fraction Attenuates LPS-Induced Inflammatory Response in Human Bronchial Epithelial Cells

To demonstrate the anti-inflammatory activity of Aronia melanocarpa fruit extract, human bronchial epithelial cells (BEAS-2B) were treated with lipopolysaccharide (LPS) and the effects of aronia bioactive fraction (ABF^®), anthocyanin enriched extract from the fruit of A. melanocarpa, were evaluated. Following pretreatment with ABF^® at 10–25 µg /mL, BEAS-2B cells were exposed to LPS and the expression of inflammatory mediators (tumor necrosis factor [TNF]-α, interleukin [IL]-6, IL-8, regulated upon activation, normal T cell expressed and presumably secreted [RANTES], IL-1β, cyclooxygenase-2 [COX-2], and inducible nitric oxide synthase [iNOS]) was analyzed. In LPS-stimulated BEAS-2B cells, ABF^® pretreatment significantly decreased the mRNA expression of TNF-α, IL-6, IL-8, RANTES, IL-1β, and COX-2 at doses of 10 and 25 µg/mL. ABF^® also attenuated the secretion of TNF- α, IL-6, IL-8, and RANTES protein, as demonstrated by enzyme linked immunosorbent assay. Western blot analyses revealed the decreased expression of COX-2 and iNOS following ABF^® treatment. ROS production was decreased, and the cell cycle was arrested at the G0/G1 and S phases following ABF^® pretreatment. Our results suggest that ABF^® may have potential as a nutraceutical agent for the suppression of airway inflammation.

Plasma Treatment Limits Cutaneous Squamous Cell Carcinoma Development In Vitro and In Vivo

Cutaneous squamous cell carcinoma (SCC) is the most prevalent cancer worldwide, increasing the cost of healthcare services and with a high rate of morbidity. Its etiology is linked to chronic ultraviolet (UV) exposure that leads to malignant transformation of keratinocytes. Invasive growth and metastasis are severe consequences of this process. Therapy-resistant and highly aggressive SCC is frequently fatal, exemplifying the need for novel treatment strategies. Cold physical plasma is a partially ionized gas, expelling therapeutic doses of reactive oxygen and nitrogen species that were investigated for their anticancer capacity against SCC in vitro and SCC-like lesions in vivo. Using the kINPen argon plasma jet, a selective growth-reducing action of plasma treatment was identified in two SCC cell lines in 2D and 3D cultures. In vivo, plasma treatment limited the progression of UVB-induced SSC-like skin lesions and dermal degeneration without compromising lesional or non-lesional skin. In lesional tissue, this was associated with a decrease in cell proliferation and the antioxidant transcription factor Nrf2 following plasma treatment, while catalase expression was increased. Analysis of skin adjacent to the lesions and determination of global antioxidant parameters confirmed the local but not systemic action of the plasma anticancer therapy in vivo.

Modulation of inflammatory pathways, medicinal uses and toxicities of Uvaria species: potential role in the prevention and treatment of inflammation

The therapeutic efficacy of the contemporary anti-inflammatory drugs are well established; however, prolonged use of such can often lead to serious and life-threatening side effects. Natural product-based anti-inflammatory compounds with superior efficacy and minimum toxicity can serve as possible therapeutic alternatives in this scenario. Genus Uvaria is a part of Annonaceae family, while the majority of its species are widely distributed in tropical rain forest regions of South East Asia. Uvaria species have been used extensively used as traditional medicine for treating all sorts of inflammatory diseases including catarrhal inflammation, rheumatism, acute allergic reactions, hemorrhoids, inflammatory liver disease and inflamed joints. Phytochemical analysis of Uvaria species has revealed flavones, flavonoids, tannins, saponins, polyoxygenated cyclohexene and phenolic compounds as major phyto-constituents. This review is an attempt to highlight the anti-inflammatory activity of Uvaria species by conducting a critical appraisal of the published literature. The ethnopharmacological relevance of Uvaria species in the light of toxicological studies is also discussed herein. An extensive and relevant literature on anti-inflammatory activity of Uvaria species was collected from available books, journals and electronic databases including PubMed, ScienceDirect, Scopus, Proquest and Ovid. Extracts and isolates of Uvaria species exhibited significant anti-inflammatory activity through various mechanisms of action. 6,7-di-O-Methyl-baicalein, flexuvarol B, chrysin, (-)-zeylenol, 6-hydroxy-5,7-dimethoxy-flavone, and pinocembrin were the most potent anti-inflammatory compounds with comparable IC₅₀ with positive controls. Therefore, it is suggested that further research should be carried out to determine the pharmacokinetics, pharmacodynamics and toxicity of these therapeutically significant compounds, to convert the pre-clinical results into clinical data for drug development and design.

NADPH oxidases: Pathophysiology and therapeutic potential in age-associated pulmonary fibrosis

Oxidative stress has been associated with a number of human fibrotic diseases, including idiopathic pulmonary fibrosis (IPF). Although oxidative stress is associated with both fibrosis and aging, the precise cellular sources(s) of reactive oxygen species (ROS) that contribute to the disease pathogenesis remain poorly understood. NADPH oxidase (Nox) enzymes are an evolutionarily conserved family, where their only known function is the production of ROS. A growing body of evidence supports a link between excessive Nox-derived ROS and numerous chronic diseases (including fibrotic disease), which is most prevalent among the elderly population. In this review, we examine the evidence for Nox isoforms in the pathogenesis of IPF, and the potential to target this enzyme family for the treatment of IPF and related fibrotic disorders. A better understanding of the Nox-mediated redox imbalance in aging may be critical to the development of more effective therapeutic strategies for age-associated fibrotic disorders. Strategies aimed at specifically blocking the source(s) of ROS through Nox inhibition may prove to be more effective as anti-fibrotic therapies, as compared to antioxidant approaches. This review also discusses the potential of Nox-targeting therapeutics currently in development.

NADPH oxidase-mediated endothelial injury in HIV- and opioid-induced pulmonary arterial hypertension

We previously demonstrated that the combined exposure of human pulmonary microvascular endothelial cells (HPMECs) to morphine and viral protein(s) results in the oxidative stress-mediated induction of autophagy, leading to shift in the cells from early apoptotic to apoptosis-resistant proliferative status associated with the angioproliferative remodeling observed in pulmonary arterial hypertension (PAH). In this study, we tried to delineate the major source of HIV-1 protein Tat and morphine induced oxidative burst in HPMECs and its consequences on vascular remodeling and PAH in an in vivo model. We observed switch from the initial increased expression of NADPH oxidase (NOX) 2 in response to acute treatment of morphine and HIV-Tat to later increased expression of NOX4 on chronic treatment in the endoplasmic reticulum of HPMECs without any alterations in the mitochondria. Furthermore, NOX-dependent induction of autophagy was observed to play a pivotal role in regulating the endothelial cell survival. Our in vivo findings showed significant increase in pulmonary vascular remodeling, right ventricular systolic pressure, and Fulton index in HIV-transgenic rats on chronic administration of morphine. This was associated with increased oxidative stress in lung tissues and rat pulmonary microvascular endothelial cells. Additionally, endothelial cells from morphine-treated HIV-transgenic rats demonstrated increased expression of NOX2 and NOX4 proteins, inhibition of which ameliorated their increased survival upon serum starvation. In conclusion, this study describes NADPH oxidases as one of the main players in the oxidative stress-mediated endothelial dysfunction on the dual hit of HIV-viral protein(s) and opioids.

Genomic and Genetic Approaches to Deciphering Acute Respiratory Distress Syndrome Risk and Mortality

Significance: Acute respiratory distress syndrome (ARDS) is a severe, highly heterogeneous critical illness with staggering mortality that is influenced by environmental factors, such as mechanical ventilation, and genetic factors. Significant unmet needs in ARDS are addressing the paucity of validated predictive biomarkers for ARDS risk and susceptibility that hamper the conduct of successful clinical trials in ARDS and the complete absence of novel disease-modifying therapeutic strategies. Recent Advances: The current ARDS definition relies on clinical characteristics that fail to capture the diversity of disease pathology, severity, and mortality risk. We undertook a comprehensive survey of the available ARDS literature to identify genes and genetic variants (candidate gene and limited genome-wide association study approaches) implicated in susceptibility to developing ARDS in hopes of uncovering novel biomarkers for ARDS risk and mortality and potentially novel therapeutic targets in ARDS. We further attempted to address the well-known health disparities that exist in susceptibility to and mortality from ARDS. Critical Issues: Bioinformatic analyses identified 201 ARDS candidate genes with pathway analysis indicating a strong predominance in key evolutionarily conserved inflammatory pathways, including reactive oxygen species, innate immunity-related inflammation, and endothelial vascular signaling pathways. Future Directions: Future studies employing a system biology approach that combines clinical characteristics, genomics, transcriptomics, and proteomics may allow for a better definition of biologically relevant pathways and genotype-phenotype connections and result in improved strategies for the sub-phenotyping of diverse ARDS patients via molecular signatures. These efforts should facilitate the potential for successful clinical trials in ARDS and yield a better fundamental understanding of ARDS pathobiology.

Focus on Early Events: Pathogenesis of Pulmonary Arterial Hypertension Development

Significance: Pulmonary arterial hypertension (PAH) is a progressive disease of the lung vasculature characterized by the proliferation of all vascular wall cell types, including endothelial, smooth muscle, and fibroblasts. The disease rapidly advances into a form with extensive pulmonary vascular remodeling, leading to a rapid increase in pulmonary vascular resistance, which results in right heart failure. Recent Advances: Most current research in the PAH field has been focused on the late stage of the disease, largely due to an urgent need for patient treatment options in clinics. Further, the pathobiology of PAH is multifaceted in the advanced disease, and there has been promising recent progress in identifying various pathological pathways related to the late clinical picture. Critical Issues: Early stage PAH still requires additional attention from the scientific community, and although the survival of patients with early diagnosis is comparatively higher, the disease develops in patients asymptomatically, making it difficult to identify and treat early. Future Directions: There are several reasons to focus on the early stage of PAH. First, the complexity of late stage disease, owing to multiple pathways being activated in a complex system with intra- and intercellular signaling, leads to an unclear picture of the key contributors to the pathobiology. Second, an understanding of early pathophysiological events can increase the ability to identify PAH patients earlier than what is currently possible. Third, the prompt diagnosis of PAH would allow for the therapy to start earlier, which has proved to be a more successful strategy, and it ensures better survival in PAH patients.

A Detailed Insight of the Anti-inflammatory Effects of Curcumin with the Assessment of Parameters, Sources of ROS and Associated Mechanisms

Background:

Curcumin is an active constituent ofCurcuma longa,which belongs to Zingiberaceae family. It is derived from the Rhizome of a perennial plant having molecular formula C21H20O6and chemically it is (1, 7- bis (4- hydroxy - 3 methoxyphenyl) -1, 6 - heptadine - 3, 5 - diene), also known as diferuloylmethane. Curcumin has been extensively used as a herbal constituent for curing several diseases and is scientifically proven to show major effects as an anti-inflammatory agent.

Objective:

Inflammation is an important factor for numerous diseases including diabetes neuropathy, cancer, asthma, arthritis, and other diseases. Prophylaxis of inflammatory diseases through synthetic medications tends to have major toxicity and side effects on a large number of population. The foremost aim of this review paper is to assess the natural anti-inflammatory effect of curcumin, source, and mechanism of action, potential therapeutic effect and models associated. Additionally, this paper aims to scrutinize inflammation, sources of reactive oxygen species, and pathways of reactive oxygen species generation and potential side effects of curcumin.

Methods:

Selection of data has been done by studying the combination of research and review papers from different databases like PubMed, Medline and Web of science from the year 1985- 2018 by using search keywords like “curcumin”, “anti-inflammatory”, “ROS”, “Curcuma longa”, “medicinal uses of curcumin”, “assessing parameters”, “inflammation”, “anti-oxidant”

Results:

On the basis of our interpretation, we have concluded that curcumin has potential therapeutic effects in different inflammatory diseases, it inhibits the inflammatory mediators, oxidation processes, and oxidative stress and has no severe toxicity on animals and humans.

Conclusion:

Oxidative stress is a major cause of inflammation and curcumin has a good potential for blocking it. Curcumin is also easily accessible herbal source and should be consumed in the form of food, antioxidant, anti-inflammatory agents and further observation should be done on its therapeutic parameters, risk factors, and toxicity studies and oral viability.

Design and synthesis of novel pyrazolo[4,3-d]pyrimidines as potential therapeutic agents for acute lung injury

Four series of total 35 new pyrazolo[4,3-d]pyrimidine compounds were designed, synthesized and evaluated for their inhibitory activity against LPS-induced NO production in RAW264.7 macrophages. Among them, compound 4e was found to be the most potent inhibitor, which decreased the production of cytokines in vitro, such as NO, IL-6 and TNF-α, with IC₅₀ values of 2.64, 4.38 and 5.63 μM, respectively. Further studies showed that compound 4e inhibited cytokines secretion of macrophages through suppressing TLR4/p38 signaling pathway. Additionally, compound 4e showed in vivo anti-inflammatory activity in LPS-induced model of acute lung injury. These data suggested that compound 4e may be a promising lead structure for the treatment of ALI.

Nitroxidized-Albumin Advanced Glycation End Product and Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease whose major clinical consequence is inflammation of small joints and contiguous structures. Oxidative and nitrosative stress along with increased formation of advanced glycation end products (AGEs) play an important role in the disease process. Generation of reactive species during glycation of proteins further adds to the oxidative and nitrosative stress. Albumin, being the most abundant plasma protein, is frequently targeted by different oxidizing and nitrating agents, including peroxynitrite (OONO-) anion. Albumin is also targeted and modified by dicarbonyl metabolites (glyoxal and methylglyoxal) which are formed in oxidative and non-oxidative processes during the synthesis of AGEs. The endogenously formed OONO- and dicarbonyls may modify plasma albumin including those albumin that have travelled or migrated to synovial cells and caused nitration, oxidation, and glycation. These modifications may produce crosslinks, aggregate in albumin and confer immunogenicity. Simultaneous modification of albumin by OONO- and dicarbonyls may generate nitroxidized-AGE-albumin which may persist in circulation for a longer duration compared to native albumin. Nitroxidized-AGE-albumin level (or serum autoantibodies against nitroxidized- AGE-albumin) along with other pre-clinical features may help predict the likely onset of RA.

5-Hydroxymethylfurfural Mitigates Lipopolysaccharide-Stimulated Inflammation via Suppression of MAPK, NF-κB and mTOR Activation in RAW 264.7 Cells

5-Hydroxymethylfurfural (5-HMF) is found in many food products including honey, dried fruits, coffee and black garlic extracts. Here, we investigated the anti-inflammatory activity of 5-HMF and its underlying mechanisms in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. 5-HMF pretreatment ranging from 31.5 to 126.0 μg/mL reduced the production of nitric oxide (NO), prostaglandin E2 (PGE2) and pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) in a concentration-dependent manner in LPS-stimulated cells. Moreover, 5-HMF-pretreated cells significantly down-regulated the mRNA expression of two major inflammatory mediators, nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and suppressed the production of pro-inflammatory cytokines, as compared with the only LPS-stimulated cells. 5-HMF suppressed the phosphorylation of extracellular regulated protein kinases (ERK1/2), c-Jun N-terminal kinase (JNK), IκBα, NF-κB p65, the mammalian target of rapamycin (mTOR) and protein kinase B (Akt). Besides, 5-HMF was proved to inhibit NF-κB p65 translocation into nucleus to activate inflammatory gene transcription. These results suggest that 5-HMF could exert the anti-inflammatory activity in the LPS-induced inflammatory response by inhibiting the MAPK, NF-κB and Akt/mTOR pathways. Thus, 5-HMF could be considered as a therapeutic ingredient in functional foods.

Magnesium isoglycyrrhizinate suppresses LPS-induced inflammation and oxidative stress through inhibiting NF-κB and MAPK pathways in RAW264.7 cells

Magnesium Isoglycyrrhizinate (MgIG), a novel molecular compound extracted from licorice root, has exhibited greater anti-inflammatory activity and hepatic protection than glycyrrhizin and β-glycyrrhizic acid. In this study, we investigated the anti-inflammatory effect and the potential mechanism of MgIG on Lipopolysaccharide (LPS)-treated RAW264.7 cells. MgIG down-regulated LPS-induced pro-inflammatory mediators and enzymes in LPS-treated RAW264.7 cells, including TNF-α, IL-6, IL-1β, IL-8, NO and iNOS. The generation of reactive oxygen species (ROS) in LPS-treated RAW264.7 cells was also reduced. MgIG attenuated NF-κB translocation by inhibiting IKK phosphorylation and IκB-α degradation. Simultaneously, MgIG also inhibited LPS-induced activation of MAPKs, including p38, JNK and ERK1/2. Taken together, these results suggest that MgIG suppresses inflammation by blocking NF-κB and MAPK signaling pathways, and down-regulates ROS generation and inflammatory mediators.

Reactive Oxygen Species Are Necessary for Bleomycin A5-Induced Apoptosis and Extracellular Matrix Elimination of Nasal Polyp-Derived Fibroblasts

BACKGROUND:

The pathology of chronic rhinosinusitis with nasal polyp (CRSwNP) is characterized by the infiltration of a large number of fibroblasts, resulting in extracellular matrix (ECM) deposition. Intralesional bleomycin A5 (BLE) injection has proved to be effective and safe, providing a novel treatment for CRSwNP. However, the mechanism is not clearly understood.

OBJECTIVES:

The aim of this study is to explore the possible mechanism of BLE-induced apoptosis in nasal polyp-derived fibroblasts (NPDFs).

MATERIAL AND METHODS:

Dichloro-dihydro-fluorescein diacetate probe, cell migration assays, and cell cycle analysis were used to detect the growth characteristics and basal reactive oxygen species (ROS) traits of NPDFs. Annexin V/propidium iodide and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay was used to detect BLE-induced apoptosis. As a control, the antioxidant glutathione (GSH) was used to abrogate ROS induced by BLE. Western blot analysis was used to evaluate the effects of BLE on apoptosis and the ECM proteins of NPDFs.

RESULTS:

The results showed that NPDFs had more active growth characteristics and higher basal ROS levels than normal nasal mucosa fibroblasts (NMFCs). NPDFs were more sensitive to BLE-induced apoptosis and ROS accumulation. GSH abrogation inhibits BLE-induced ECM degradation and apoptosis in NPDFs through a mitochondrial-mediated pathway.

CONCLUSIONS:

BLE induced NPDF apoptosis and ECM degradation through a mitochondrial-mediated pathway and in a ROS-dependent manner.

Oxidative/nitrosative stress, autophagy and apoptosis as therapeutic targets of melatonin in idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease associated with disruption of alveolar epithelial cell layer and expansion of fibroblasts/myofibroblasts. Excessive levels of oxidative/nitrosative stress, induction of apoptosis, and insufficient autophagy may be involved in IPF pathogenesis; hence, the targeting of these pathways may ameliorate IPF. Areas covered: We describe the ameliorative effect of melatonin on IPF. We summarize the research on IPF pathogenesis with a focus on oxidative/nitrosative stress, autophagy and apoptosis pathways and discuss the potential effects of melatonin on these pathways. Expert opinion: Oxidative/nitrosative stress, apoptosis and autophagy could be interesting targets for therapeutic intervention in IPF. Melatonin, as a potent antioxidant, induces the expression of antioxidant enzymes, scavenges free radicals and modulates apoptosis and autophagy pathways. The effect of melatonin in the induction of autophagy could be an important mechanism against fibrotic process in IPF lungs. Further clinical studies are necessary to determine if melatonin could be a candidate for treating IPF.

Detection of hydrogen peroxide production in the isolated rat lung using Amplex red

The objectives of this study were to develop a robust protocol to measure the rate of hydrogen peroxide (H₂O₂) production in isolated perfused rat lungs, as an index of oxidative stress, and to determine the cellular sources of the measured H₂O₂ using the extracellular probe Amplex red (AR). AR was added to the recirculating perfusate in an isolated perfused rat lung. AR's highly fluorescent oxidation product resorufin was measured in the perfusate. Experiments were carried out without and with rotenone (complex I inhibitor), thenoyltrifluoroacetone (complex II inhibitor), antimycin A (complex III inhibitor), potassium cyanide (complex IV inhibitor), or diohenylene iodonium (inhibitor of flavin-containing enzymes, e.g. NAD(P)H oxidase or NOX) added to the perfusate. We also evaluated the effect of acute changes in oxygen (O₂) concentration of ventilation gas on lung rate of H₂O₂ release into the perfusate. Baseline lung rate of H₂O₂ release was 8.45 ± 0.31 (SEM) nmol/min/g dry wt. Inhibiting mitochondrial complex II reduced this rate by 76%, and inhibiting flavin-containing enzymes reduced it by another 23%. Inhibiting complex I had a small (13%) effect on the rate, whereas inhibiting complex III had no effect. Inhibiting complex IV increased this rate by 310%. Increasing %O₂ in the ventilation gas mixture from 15 to 95% had a small (27%) effect on this rate, and this O₂-dependent increase was mostly nonmitochondrial. Results suggest complex II as a potentially important source and/or regulator of mitochondrial H₂O₂, and that most of acute hyperoxia-enhanced lung rate of H₂O₂ release is from nonmitochondrial rather than mitochondrial sources.

Gestational Hypoxia and Developmental Plasticity

Hypoxia is one of the most common and severe challenges to the maintenance of homeostasis. Oxygen sensing is a property of all tissues, and the response to hypoxia is multidimensional involving complicated intracellular networks concerned with the transduction of hypoxia-induced responses. Of all the stresses to which the fetus and newborn infant are subjected, perhaps the most important and clinically relevant is that of hypoxia. Hypoxia during gestation impacts both the mother and fetal development through interactions with an individual's genetic traits acquired over multiple generations by natural selection and changes in gene expression patterns by altering the epigenetic code. Changes in the epigenome determine "genomic plasticity," i.e., the ability of genes to be differentially expressed according to environmental cues. The genomic plasticity defined by epigenomic mechanisms including DNA methylation, histone modifications, and noncoding RNAs during development is the mechanistic substrate for phenotypic programming that determines physiological response and risk for healthy or deleterious outcomes. This review explores the impact of gestational hypoxia on maternal health and fetal development, and epigenetic mechanisms of developmental plasticity with emphasis on the uteroplacental circulation, heart development, cerebral circulation, pulmonary development, and the hypothalamic-pituitary-adrenal axis and adipose tissue. The complex molecular and epigenetic interactions that may impact an individual's physiology and developmental programming of health and disease later in life are discussed.

ROS Signaling in the Pathogenesis of Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS)

The generation of reactive oxygen species (ROS) plays an important role for the maintenance of cellular processes and functions in the body. However, the excessive generation of oxygen radicals under pathological conditions such as acute lung injury (ALI) and its most severe form acute respiratory distress syndrome (ARDS) leads to increased endothelial permeability. Within this hallmark of ALI and ARDS, vascular microvessels lose their junctional integrity and show increased myosin contractions that promote the migration of polymorphonuclear leukocytes (PMNs) and the transition of solutes and fluids in the alveolar lumen. These processes all have a redox component, and this chapter focuses on the role played by ROS during the development of ALI/ARDS. We discuss the origins of ROS within the cell, cellular defense mechanisms against oxidative damage, the role of ROS in the development of endothelial permeability, and potential therapies targeted at oxidative stress.