TNF and ROS Crosstalk in Inflammation

Comparison of genotoxic versus nongenotoxic stabilization of p53 provides insight into parallel stress-responsive transcriptional networks

The tumor suppressor protein p53 is activated in response to diverse intrinsic and extrinsic cellular stresses and controls a broad cell-protective gene network. Whether p53:DNA binding and subsequent transcriptional activation differs downstream of these diverse intrinsic and extrinsic activators is controversial. Using primary human fibroblasts, we assessed the genome-wide profile of p53 binding, chromatin structure, and transcriptional dynamics after either genotoxic or nongenotoxic activation of p53. Activation of p53 by treatment with either etoposide or the small-molecule MDM2 inhibitor nutlin 3A yields strikingly similar genome-wide binding of p53 and concomitant changes to local chromatin modifications and structure. DNA damage, but not p53 activation per se, leads to increased expression of genes in an inflammatory cytokine pathway. The NF-κB pathway inhibitor Bay 11-7082 abrogates etoposide-mediated activation of the inflammation gene signature but does not affect expression of canonical p53 target genes. Our data demonstrate that differential activation of p53 within the same cell type leads to highly similar genome-wide binding, chromatin dynamics, and gene expression dynamics and that DNA damage-mediated signaling through NF-κB likely controls the observed pro-inflammatory cytokine gene expression pattern.

RETRACTED: Silence of lncRNA CHRF protects H9c2 cells against lipopolysaccharide-induced injury via up-regulating microRNA-221

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Given the comments of Dr Elisabeth Bik regarding this article “… the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Oxidative hotspots on actin promote skeletal muscle weakness in rheumatoid arthritis

Skeletal muscle weakness in patients suffering from rheumatoid arthritis (RA) adds to their impaired working abilities and reduced quality of life. However, little molecular insight is available on muscle weakness associated with RA. Oxidative stress has been implicated in the disease pathogenesis of RA. Here we show that oxidative post-translational modifications of the contractile machinery targeted to actin result in impaired actin polymerization and reduced force production. Using mass spectrometry, we identified the actin residues targeted by oxidative 3-nitrotyrosine (3-NT) or malondialdehyde adduct (MDA) modifications in weakened skeletal muscle from mice with arthritis and patients afflicted by RA. The residues were primarily located to three distinct regions positioned at matching surface areas of the skeletal muscle actin molecule from arthritis mice and RA patients. Moreover, molecular dynamic simulations revealed that these areas, here coined "hotspots", are important for the stability of the actin molecule and its capacity to generate filaments and interact with myosin. Together, these data demonstrate how oxidative modifications on actin promote muscle weakness in RA patients and provide novel leads for targeted therapeutic treatment to improve muscle function.

Engulfment, persistence and fate of Bdellovibrio bacteriovorus predators inside human phagocytic cells informs their future therapeutic potential

In assessing the potential of predatory bacteria, such as Bdellovibrio bacteriovorus, to become live therapeutic agents against bacterial infections, it is crucial to understand and quantify Bdellovibrio host cell interactions at a molecular level. Here, we quantify the interactions of live B. bacteriovorus with human phagocytic cells, determining the uptake mechanisms, persistence, associated cytokine responses and intracellular trafficking of the non-growing B. bacteriovorus in PMA-differentiated U937 cells. B. bacteriovorus are engulfed by U937 cells and persist for 24 h without affecting host cell viability and can be observed microscopically and recovered and cultured post-uptake. The uptake of predators is passive and depends on the dynamics of the host cell cytoskeleton; the engulfed predators are eventually trafficked through the phagolysosomal pathway of degradation. We have also studied the prevalence of B. bacteriovorus specific antibodies in the general human population. Together, these results quantify a period of viable persistence and the ultimate fate of B. bacteriovorus inside phagocytic cells. They provide new knowledge on predator availability inside hosts, plus potential longevity and therefore potential efficacy as a treatment in humans and open up future fields of work testing if predators can prey on host-engulfed pathogenic bacteria.

[Ru(bpy)2(NO)SO3](PF6), a Nitric Oxide Donating Ruthenium Complex, Reduces Gout Arthritis in Mice

Monosodium urate crystals (MSU) deposition induces articular inflammation known as gout. This disease is characterized by intense articular inflammation and pain by mechanisms involving the activation of the transcription factor NFκB and inflammasome resulting in the production of cytokines and oxidative stress. Despite evidence that MSU induces iNOS expression, there is no evidence on the effect of nitric oxide (NO) donors in gout. Thus, the present study evaluated the effect of the ruthenium complex donor of NO {[Ru(bpy)₂(NO)SO₃](PF₆)} (complex I) in gout arthritis. Complex I inhibited in a dose-dependent manner MSU-induced hypersensitivity to mechanical stimulation, edema and leukocyte recruitment. These effects were corroborated by a decrease of histological inflammation score and recruitment of Lysm-eGFP⁺ cells. Mechanistically, complex I inhibited MSU-induced mechanical hypersensitivity and joint edema by triggering the cGMP/PKG/ATP-sensitive K (+) channels signaling pathway. Complex I inhibited MSU-induced oxidative stress and pro-inflammatory cytokine production in the knee joint. These data were supported by the observation that complex I inhibited MSU-induced NFκB activation, and IL-1β expression and production. Complex I also inhibited MSU-induced activation of pro-IL-1β processing. Concluding, the present data, to our knowledge, is the first evidence that a NO donating ruthenium complex inhibits MSU-induced articular inflammation and pain. Further, complex I targets the main physiopathological mechanisms of gout arthritis. Therefore, it is envisaged that complex I and other NO donors have therapeutic potential that deserves further investigation.

4-Hexylresorcinol and silk sericin increase the expression of vascular endothelial growth factor via different pathways

Angiogenesis plays an important role in active inflammation and wound healing. Our results showed that silk sericin and 4-hexylresorcinol (4HR) increased vascular endothelial growth factor (VEGF) expression in a dose-dependent manner in RAW264.7 cells. Unlike 4HR, silk sericin increased the expression of hypoxia inducible factor-1α (HIF-1α) and HIF-2α. Pretreatment with an HIF inhibitor decreased the sericin-induced increase in VEGF expression. However, the HIF inhibitor did not affect the 4HR-induced increase in VEGF expression. An inhibitor of matrix metalloproteinase (MMP) declined the 4HR-induced increase in VEGF expression. Silk sericin increased production of reactive oxygen species (ROS), whereas 4HR decreased ROS. M1 markers were increased by silk sericin treatment, and M2 markers were increased by 4HR treatment. VEGF and angiogenin expression were higher in rats treated with a 4HR-incorporated silk mat than in rats treated with a silk mat alone. In conclusion, silk sericin and 4HR increased VEGF expression in RAW264.7 cells via HIF-mediated and MMP-mediated pathways, respectively. Silk sericin exerted like pro-oxidant effects and 4HR exerted anti-oxidant effects. Rats treated with a 4HR-incorporated silk mat showed higher levels of VEGF and angiogenin than those treated with a silk mat alone.

Apios americana Medikus tuber polysaccharide exerts anti-inflammatory effects by activating autophagy

The tubers of Apios americana Medikus possess high nutritional value and have been used as food in many countries for a long time. However, few researches have focused on the tuber polysaccharides. In the present study, a purified polysaccharide (ATP-1) was isolated with the average molecular weights of 12.16 kDa. ATP-1 significantly suppressed the release of nitric oxide (NO) and inflammatory cytokines from LPS-induced RAW 264.7 cells, as well as oxidative stress and mitochondrial dysfunction. Meanwhile, ATP-1 reduced oxidative damage via the NF-κB, MAPKs and Nrf2-Keap1 signaling pathways in RAW264.7 macrophages. Furthermore, autophagy was activated by HMGB1-Beclin1, Sirt1-FoxO1 and Akt-mTOR signaling pathways, leading to a relief of oxidative stress, mitochondrial dysfunction, inflammation and an expression enhancement of autophagy-related proteins, such as LC3, Beclin1, Atg4, Atg5, and Atg7. In summary, our results suggested that ATP-1 might help to activate the anti-inflammation system，resulting in prevention of LPS-induced damage in RAW264.7 cells.

Cell-specific immune-modulation of cadmium on murine macrophages and mast cell lines in vitro

Toxic trace metals are widespread contaminants that are potentially immunotoxic even at environmentally low exposure levels. They can modulate the immunity to infections, e.g., in wildlife species living in contaminated areas. The diverse immune cell types can be differentially affected by the exposure leading to the modulation of specific protective mechanisms. Macrophages and mast cells, part of the innate immune system, trigger immune responses and perform particular effector functions. The present study compared toxicological and functional effects of cadmium in two models of murine macrophages (RAW264.7 and NR8383 cell lines) and two models of murine mast cells (MC/9 and RBL-2H3 cell lines). Cadmium was selected as a model compound because its known potential to induce reactive oxygen species and its relevance as an environmental contaminant. Mechanisms of toxicity, such as redox imbalance and apoptosis induction were measured in stationary cells, while functional outcome effects were measured in activated cells. Cadmium-depleted glutathione antioxidant in all four cell lines tested although reactive oxygen species was not significantly increased. Mast cells had full dose-response depletion of glutathione below cytotoxic levels while in macrophages the depletion was not complete. Functional endpoints tumour necrosis factor-alpha and nitrite production in lipopolysaccharide-activated macrophages were increased by cadmium exposure. In contrast, mast cell lipopolysaccharide-induced tumour necrosis factor-alpha and IgE-mediated histamine release were reduced by cadmium. These data indicate potentially differential effects of cadmium among murine innate immune cell types, where mast cells would be more susceptible to oxidative stress and their function might be at a higher risk to be modulated compared to macrophages.

Participation of NADPH Oxidase-Related Reactive Oxygen Species in Leptin-Promoted Pulmonary Inflammation: Regulation of cPLA2α and COX-2 Expression

Obesity is a worldwide epidemic problem and correlates to varieties of acute or chronic lung diseases such as acute respiratory distress syndrome, chronic obstructive pulmonary disease, and pulmonary fibrosis. An increase of leptin, a kind of adipokine, in lean mice plasma has been found to impair immune responses and facilitate the infection of Klebsiella pneumoniae, resulting in increased pneumonia severity. Also, a higher leptin level is found in exhaled breath condensates of obese or asthmatic subjects, compared to healthy ones, suggesting that leptin is involved in the occurrence or exacerbation of lung injury. In previous studies, we showed that leptin stimulated cytosolic phospholipase A2-α (cPLA2α) gene expression in lung alveolar type II cells via mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB)-activated coactivator p300. Herein, we show that the in vivo application of leptin in the respiratory system upregulated the expression of inflammatory proteins cPLA2α and cyclooxygenase-2 (COX-2) together with leukocyte infiltration. Treatment with an ROS scavenger (N-acetylcysteine, NAC), an NADPH oxidase inhibitor (apocynin), or an activating protein (AP)-1 inhibitor (tanshinone IIA) attenuated leptin-mediated cPLA2α/COX-2 expression and leukocyte recruitment in the lung. Leptin increased intracellular oxidative stress in a leptin receptor (OB-R) and NADPH oxidase-dependent manner, leading to the phosphorylation of the AP-1 subunit c-Jun. In summation, leptin increased lung cPLA2α/COX-2 expression and leukocyte recruitment via the NADPH oxidase/ROS/AP-1 pathway. Understanding the inflammatory effects of leptin on the pulmonary system provides opportunities to develop strategies against lung injury related to metabolic syndrome or obesity.

Glutathione accelerates osteoclast differentiation and inflammatory bone destruction

Chronic inflammation associated with bone tissues often destructs bones, which is essentially performed by osteoclasts in the presence of immunoregulatory molecules. Hence, regulating osteoclastogenesis is crucial to develop therapeutics for bone-destructive inflammatory diseases. It is believed that reactive oxygen species (ROS) are involved in receptor activator of NF-κB (RANK) ligand (RANKL)-induced osteoclast differentiation, and, therefore, glutathione (GSH), the most abundant endogenous antioxidant, suppresses osteoclast differentiation and bone resorption by RANKL. Interestingly, GSH also contributes to inflammatory responses, and the effects of GSH on osteoclast differentiation and bone destruction under inflammatory conditions have not yet been determined. Here, we investigated how GSH affects inflammatory cytokine-stimulated osteoclast differentiation in vitro and in a mouse model of inflammatory bone destruction. We found that GSH significantly promoted TNFα-stimulated osteoclast formation, while an inhibitor of GSH synthesis, buthionine sulfoximine, suppressed it. GSH facilitated the nuclear localisation of the nuclear factor of activated T cells c1 (NFATc1) protein, a master regulator of osteoclastogenesis, as well as the expression of osteoclast marker genes in a dose-dependent manner. N-acetylcysteine, a substrate of GSH synthesis, also stimulated osteoclast formation and NFATc1 nuclear localisation. GSH did not suppress cell death after osteoclast differentiation. In mouse calvaria injected with lipopolysaccharide, GSH treatment resulted in a fivefold increase in the osteolytic lesion area. These results indicate that GSH accelerates osteoclast differentiation and inflammatory bone destruction, suggesting GSH appears to be an important molecule in the mechanisms responsible for inflammatory bone destruction by osteoclasts.

A new perspective on oxidation of DNA repair proteins and cancer

Reactive oxygen and nitrogen species (RONS) are formed as byproducts of many endogenous cellular processes, in response to infections, and upon exposure to various environmental factors. An increase in RONS can saturate the antioxidation system and leads to oxidative stress. Consequently, macromolecules are targeted for oxidative modifications, including DNA and protein. The oxidation of DNA, which leads to base modification and formation of abasic sites along with single and double strand breaks, has been extensively investigated. Protein oxidation is often neglected and is only recently being recognized as an important regulatory mechanism of various DNA repair proteins. This is a review of the current state of research on the regulation of DNA repair by protein oxidation with emphasis on the correlation between inflammation and cancer.

Atrial Natriuretic Peptide: A Potential Early Therapy for the Prevention of Multiple Organ Dysfunction Syndrome Following Severe Trauma

Trauma remains a tremendous medical burden partly because of increased expenditure for the management of multiple organ dysfunction syndrome (MODS) developed during hospital stay. The intestinal barrier injury continues to be a second insult resulting in MODS which currently lacks efficient strategies for prevention. Recent studies have uncovered multi-organ protective benefits of atrial natriuretic peptide (ANP) in cardiovascular disease. However, the role of ANP in the prevention of MODS following severe trauma has not been understood. In our laboratory study, 1-h infusion of exogenous ANP during hemorrhagic shock following severe trauma induced high-level expression of endogenous serum ANP after 24 h, this effect was related to the improved level of functional biomarkers in multiple organs. Such phenomenon has not been found in other laboratories. A thorough literature review consequently was performed to uncover the potential mechanisms, to appraise therapy safety, and to propose uncertainties. In severe trauma, short-term exogenous ANP therapy during hemorrhagic shock may promote sustained endogenous expression of ANP from intestinal epithelium through activating a positive feedback loop mechanism involving phospholipase C-γ1 and reactive oxygen species crosstalk. This feedback loop may prevent MODS through multiple signaling pathways. Administration of ANP during hemorrhagic shock is thought to be safe. Further studies are required to confirm our proposed mechanisms and to investigate the dose, duration, and timing of ANP therapy in severe trauma.

Ghrelin protects against contact dermatitis and psoriasiform skin inflammation by antagonizing TNF-α/NF-κB signaling pathways

Contact dermatitis and psoriasis are skin disorders caused by immune dysregulation, yet much remains unknown about their underlying mechanisms. Ghrelin, a recently discovered novel peptide and potential endogenous anti-inflammatory factor expressed in the epidermis, is involved in skin repair and disease. In this study, we investigated the expression pattern and therapeutic effect of ghrelin in both contact dermatitis and psoriasis mouse models induced by oxazolone (OXA) and imiquimod (IMQ), respectively, and in TNF-α-stimulated RAW264.7 macrophages, NHEKs and skin fibroblasts. Ghrelin expression was reduced in both the OXA-induced contact dermatitis and IMQ-induced psoriasis mouse models. Furthermore, treatment with ghrelin attenuated skin inflammation in both the contact dermatitis and psoriasis mouse models. Mice administered PBS after OXA- or IMQ-induced model generation exhibited typical skin inflammation, whereas ghrelin treatment in these mouse models substantially decreased the dermatitis phenotype. In addition, exogenous ghrelin attenuated the inflammatory reaction induced by TNF-α in RAW264.7 cells. Moreover, ghrelin administration limited activation of NF-κB signaling. In summary, ghrelin may represent a potential molecular target for the prevention and treatment of inflammatory skin diseases, including contact dermatitis and psoriasis.

Tetramethylpyrazine reduces inflammation in the livers of mice fed a high fat diet

The present study aimed to assess the protective effects of tetramethylpyrazine (TMP) on the livers of mice fed a high fat diet. The mice were divided into five groups: Regular diet; high fat diet; simvastatin‑treated; and low and high dose TMP‑treated groups. The results demonstrated that, compared with the control group, serum glucose, total cholesterol (TC) and low‑density lipoprotein cholesterol levels were increased in the model group. Additionally, compared with the model group, simvastatin lowered the TC level, whereas TMP did not. Compared with the control group, the level of malondialdehyde (MDA) in the liver tissue was increased and the level of glutathione peroxidase (GSH‑pX) in the liver tissue was decreased in the model group. Furthermore, compared with the model group, TMP decreased the level of MDA and increased the level of GSH‑Px; however, simvastatin did not have these effects. Immunohistochemistry and western blotting were performed; the results showed that, compared with the control group, the levels of inflammatory factors (tumor necrosis factor‑α and interleukin‑6) in the liver tissue were increased, and the ratio of phosphorylated (p)‑nuclear factor κB (NF‑κB)/NF‑κB was also increased in the model group. The addition of TMP and simvastatin demonstrated that, compared with the model group, the inflammatory factor levels and the ratio of p‑NF‑κB/NF‑κB were decreased. In addition, liver lipid deposition was examined in the model group using hematoxylin and eosin staining and Oil Red O staining, and the results showed that TMP and simvastatin reduced liver lipid deposition. Furthermore, compared with the control group, the reactive oxygen species (ROS) level in the liver tissue was increased. Compared with that in the model group, TMP and simvastatin decreased the ROS level. In conclusion, TMP, similar to simvastatin, exerted a notable hepatoprotective effect on mice fed a high fat diet with non‑alcoholic fatty liver disease, by inhibiting inflammatory factors and the p‑NF‑κB/ROS signaling pathway.

Modulation of α-adrenoceptor signalling protects photoreceptors after retinal detachment by inhibiting oxidative stress and inflammation

BACKGROUND AND PURPOSE

Currently available treatments do not halt progression of photoreceptor death and subsequent visual impairment related to retinal detachment (RD) which is observed in various retinal disorders. This study investigated the neuroprotective effects of two adrenoceptor ligands, the α₁ -adrenoceptor antagonist doxazosin and the α₂ -adrenoceptor agonist guanabenz, against photoreceptor cell death in RD.

EXPERIMENTAL APPROACH

We used a model of experimental RD in Brown-Norway rats induced by subretinal injection of sodium hyaluronate. Oxidative stress biomarkers and cytokine production were quantified with elisa. Protein expression levels and immunofluorescent labelling were determined in rats with RD and controls for mechanistic elucidation. The effects of systemic (i.p.) administration of doxazosin or guanabenz on photoreceptor apoptosis, retinal histology and electroretinography were evaluated in rats with RD and compared to the effects in vehicle controls.

KEY RESULTS

Photoreceptors were the major source of RD-induced ROS overproduction in the rat retina through the regulation of NADPH oxidase. Systemic administration of doxazosin or guanabenz decreased the RD-induced production of ROS and proinflammatory cytokines, including IL-1β and the chemokine CCL2, and suppressed retinal gliosis, resulting in attenuation of photoreceptor death and preservation of retinal structures and functions in RD.

CONCLUSIONS AND IMPLICATIONS

Our findings point to α-adrenoceptors as novel therapeutic targets to provide photoreceptor protection and suggest that both doxazosin and guanabenz, two FDA-approved drugs, could be further explored to treat retinal diseases.

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.

Anti-apoptosis effect of amino acid modified gadofullerene via a mitochondria mediated pathway

A proposed molecular mechanism of the anti-apoptosis effect of GF-Ala through a mitochondria mediated pathway.

Baicalin Ameliorates Collagen-Induced Arthritis Through the Suppression of Janus Kinase 1 (JAK1)/Signal Transducer and Activator of Transcription 3 (STAT3) Signaling in Mice

Background

Rheumatoid arthritis is an autoimmune disease that causes chronic joint inflammation and there is no cure. Baicalin, as an ingredient in the roots of Scutellaria baicalensis, is supposed to possess an anti-inflammatory effect. However, the protective effect of baicalin on collagen-induced arthritis requires further investigation.

Material/Methods

A model of rheumatoid arthritis was established in 20 mice (8- to 10-weeks old). The mice were randomly divided into 2 groups after modeling and then injected with saline or baicalin, respectively. The synovial fluids and tissues were collected, and the pressure pain threshold and clinical arthritis score were measured. The levels of tumor necrosis factor (TNF)-α, interlukin-1β (IL-1β), IL-6, matrix metalloproteinases (MMP)-2, MMP-9, nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and their downstream inflammatory mediators Janus kinase 1 (JAK1)/signal transducer and activator of transcription 3 (STAT3), extracellular signal-regulated kinases 1/2 (ERK1/2), p38, Jun N-terminal kinases (JNK) activation were detected using enzyme-linked immunosorbent assay (ELISA), and western blotting analyses. The mononuclear cells apoptosis ratio was calculated by flowcytometry analyses.

Results

Baicalin significantly reduced disease activities in a rheumatoid arthritis mouse model, which were reflected by pressure pain thresholds and clinical arthritis scores. Relevant proinflammatory cytokines such as TNF-α, IL-1β, IL-6, gelatinases (MMP-2, MMP-9) and inducible enzymes (iNOS, COX-2) were generally suppressed. Moreover, baicalin treatment induced cells apoptosis in synovial fluid monocytes and markedly down regulated JAK1/STAT3 but not mitogen-activated protein kinases (MAPKs) expressions in synovium of arthritis.

Conclusions

These observations confirm the relief of rheumatoid arthritis by baicalin. Our results indicate the effect is related with the modulation of decreased proinflammatory cytokines and inflammatory markers. And the apoptosis promotion of monocytes in synovial fluid were also inhibited. Moreover, the molecular mechanism implies suppressed JAK1/STAT3 signaling with baicalin treatment.

Melatonin restricts the viability and angiogenesis of vascular endothelial cells by suppressing HIF-1α/ROS/VEGF

Angiogenesis is an essential process involved in various physiological, including placentation, and pathological, including cancer and endometriosis, processes. Melatonin (MLT), a well-known natural hormone secreted primarily in the pineal gland, is involved in regulating neoangiogenesis and inhibiting the development of a variety of cancer types, including lung and breast cancer. However, the specific mechanism of its anti-angiogenesis activity has not been systematically elucidated. In the present study, the effect of MLT on viability and angiogenesis of human umbilical vein endothelial cells (HUVECs), and the production of vascular endothelial growth factor (VEGF) and reactive oxygen species (ROS), under normoxia or hypoxia was analyzed using Cell Counting kit 8, tube formation, flow cytometry, ELISA and western blot assays. It was determined that the secretion of VEGF by HUVECs was significantly increased under hypoxia, while MLT selectively obstructed VEGF release as well as the production of ROS under hypoxia. Furthermore, MLT inhibited the viability of HUVECs in a dose-dependent manner and reversed the increase in cell viability and tube formation that was induced by hypoxia/VEGF/H₂O₂. Additionally, treatment with an inhibitor of hypoxia inducible factor (HIF)-1α (KC7F2) and MLT synergistically reduced the release of ROS and VEGF, and inhibited cell viability and tube formation of HUVECs. These observations demonstrate that MLT may serve dual roles in the inhibition of angiogenesis, as an antioxidant and a free radical scavenging agent. MLT suppresses the viability and angiogenesis of HUVECs through the downregulation of HIF-1α/ROS/VEGF. In summary, the present data indicate that MLT may be a potential anticancer agent in solid tumors with abundant blood vessels, particularly combined with KC7F2.

Hydroxytyrosol Exerts Anti-Inflammatory and Anti-Oxidant Activities in a Mouse Model of Systemic Inflammation

Hydroxytyrosol (3,4-dihydroxyphenil-ethanol, HT), the major phenol derived from olive oil consumption, has shown different anti-inflammatory and anti-oxidant activities in vitro which may explain the chronic-degenerative diseases preventive properties of olive oil. The aim of this study was to examine the ability of HT reduce inflammatory markers, Cyclooxygenase-2 (COX2) and Tumour Necrosis Factor alfa (TNF-α and oxidative stress in vivo on a mouse model of systemic inflammation. Balb/c mice were pre-treated with HT (40 and 80 mg/Kg b.w.) and then stimulated by intraperitoneal injection of lipopolysaccharide (LPS). Blood was collected to measure COX2 gene expression by qPCR and TNF-α level by ELISA kit in plasma. In addition, the total anti-oxidant power of plasma and the DNA damage were measured by FRAP test and COMET assay, respectively. LPS increased the COX2 expression, the TNF-α production and the DNA damage. HT administration prevented all LPS-induced effects and improved the anti-oxidant power of plasma. HT demonstrated in vivo anti-inflammatory and anti-oxidant abilities. The results may explain the health effects of olive oil in Mediterranean diet. HT represents an interesting molecule for the development of new nutraceuticals and functional food useful in chronic diseases prevention.

The Role of NADPH Oxidases and Oxidative Stress in Neurodegenerative Disorders

For a number of years, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOX) was synonymous with NOX2/gp91^phox and was considered to be a peculiarity of professional phagocytic cells. Over the last decade, several more homologs have been identified and based on current research, the NOX family consists of NOX1, NOX2, NOX3, NOX4, NOX5, DUOX1 and DUOX2 enzymes. NOXs are electron transporting membrane proteins that are responsible for reactive oxygen species (ROS) generation-primarily superoxide anion (O₂^●-), although hydrogen peroxide (H₂O₂) can also be generated. Elevated ROS leads to oxidative stress (OS), which has been associated with a myriad of inflammatory and degenerative pathologies. Interestingly, OS is also the commonality in the pathophysiology of neurodegenerative disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). NOX enzymes are expressed in neurons, glial cells and cerebrovascular endothelial cells. NOX-mediated OS is identified as one of the main causes of cerebrovascular damage in neurodegenerative diseases. In this review, we will discuss recent developments in our understanding of the mechanisms linking NOX activity, OS and neurodegenerative diseases, with particular focus on the neurovascular component of these conditions. We conclude highlighting current challenges and future opportunities to combat age-related neurodegenerative disorders by targeting NOXs.

Effect of hypoxia/reoxygenation on the biological effect of IGF system and the inflammatory mediators in cultured synoviocytes

Hypoxia/reoxygenation (H/R) plays an important role in the pathogenesis of osteoarthritis. Fibroblast-like synoviocytes (FLS), which are highly sensitive to H/R, are thought to be associated with cartilage degradation during osteoarthritis development. In this study, we investigated the biological effects of insulin-like growth factor (IGF) system and the expression of inflammatory mediators in FLS. We also pretreated FLS with tumor necrosis factor-α (TNF-α) before H/R in order to observe the response of FLS with the background of inflammatory cytokines. H/R increased the levels of TNF-α-induced C-C chemokine ligand 5 (CCL5), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in cell-free culture supernatants; H/R also increased the expression of TNF-α-induced insulin-like growth factor binding protein 3 (IGFBP-3), downregulated the expression of insulin-like growth factor 1 (IGF-1), promoted the loss of mitochondrial membrane potential (MMP), the openness of mitochondrial permeability transition pore (MPTP), the release of intracellular reactive oxygen species (ROS), and mitochondrial matrix swelling, outer membrane rupture and decrease in cristae. Furthermore, H/R induced the expression of catabolic factors and activated the NF-κB signaling pathway in FLS. We therefore concluded that H/R may play a role in inducing inflammation and increase the TNF-α-induced inflammatory effect in FLS, contributing to osteoarthritis pathogenesis.

Nrf2: Molecular and epigenetic regulation during aging

Increase in life-span is commonly related with age-related diseases and with gradual loss of genomic, proteomic and metabolic integrity. Nrf2 (Nuclear factor-erythroid 2-p45 derived factor 2) controls the expression of genes whose products include antioxidant proteins, detoxifying enzymes, drug transporters and numerous cytoprotective proteins. Several experimental approaches have evaluated the potential regulation of the transcription factor Nrf2 to enhance the expression of genes that contend against accumulative oxidative stress and promote healthy aging. Negative regulators of Nrf2 that act preventing it´s binding to DNA-responsive elements, have been identified in young and adult animal models. However, it is not clearly established if Nrf2 decreased activity in several models of aging results from disruption of that regulation. In this review, we present a compilation of evidences showing that changes in the levels or activity of Keap1 (Kelch-like ECH associated protein 1), GSK-3β (glycogen synthase kinase-3), Bach1, p53, Hrd1 (E3 ubiquitin ligase) and miRNAs might impact on Nrf2 activity during elderly. We conclude that understanding Nrf2 regulatory mechanisms is essential to develop a rational strategy to prevent the loss of cellular protection response during aging.

The role of RIP3 in cardiomyocyte necrosis induced by mitochondrial damage of myocardial ischemia-reperfusion

Myocardial damage caused by myocardial ischemia-reperfusion injury (MIRI) is difficult to be alleviated because cardiomyocyte necrosis is an irreversible and unregulated death form. Recently, necroptosis, a necrosis form caused by tumor necrosis factor-α (TNF-α) and Fas ligand (FasL), was found to be regulated by receptor interacting protein 3 (RIP3) and RIP3-receptor interacting protein 1 (RIP1)-mixed lineage kinase domain like protein (MLKL) pathway. But it is unclear whether they also play a regulatory role in MIRI-induced necroptosis. Our previous results showed that in rat MIRI, RIP3 could translocate and express highly in mitochondria. Therefore, it is important to explore proteins that interact with RIP3 which was translocated to mitochondria. The aim of this study was to explore the role of RIP3 in cardiomyocyte necrosis induced by mitochondrial damage of hypoxia/reoxygenation (H/R). Our results showed that H/R could cause RIP3-depended mitochondrial fragmentation and necrosis-based death; and RIP3-promoted H/R-induced necroptosis in H9c2 cells through increasing lactate dehydrogenase release and inhibiting cell viability. This process did not require RIP1 or MLKL but dynamin-related protein 1 (Drp1), which was related to Drp1 activation, reactive oxygen species elevation, and ΔΨm decline. This study provides novel insights into the role of RIP3 in cardiomyocyte injury during H/R. RIP3 may serve as a potential target for the treatment of MIRI.

Nothofagin suppresses mast cell-mediated allergic inflammation

Mast cells play a major role in immunoglobulin E-mediated allergic inflammation, which is involved in asthma, atopic dermatitis, and allergic rhinitis. Nothofagin has been shown to ameliorate various inflammatory responses such as the septic response and vascular inflammation. In this study, we assessed the inhibitory effect of nothofagin on allergic inflammation using cultured/isolated mast cells and an anaphylaxis mouse model. Nothofagin treatment prevented histamine and β-hexosaminidase release by reducing the influx of calcium into the cytosol in a concentration-dependent manner. Nothofagin also inhibited the gene expression and secretion of pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin-4 by downregulating the phosphorylation of Lyn, Syk, Akt and nuclear translocation of nuclear factor-κB. To confirm these effects of nothofagin in vivo, we used a passive cutaneous anaphylaxis mouse model. Topical administration of nothofagin suppressed local pigmentation and ear thickness. Taken together, these results suggest nothofagin as a potential candidate for the treatment of mast cell-involved allergic inflammatory diseases.

Chelerythrine Attenuates the Inflammation of Lipopolysaccharide-Induced Acute Lung Inflammation Through NF-κB Signaling Pathway Mediated by Nrf2

Chelerythrine (CH), is a kind of benzo[c] phenanthridine alkaloid isolated from plants such as Chelidonium, with pharmacological activities as antitumor, antibiosis and anti-inflammation. However, few studies have demonstrated whether CH could protect against lipopolysaccharide (LPS)-induced acute lung injury (ALI), and the underlying mechanism is also uncertain. The purpose of the present study was to investigate the anti-inflammatory effects of CH on LPS-induced ALI in mice and in RAW264.7 cells. In this study, we demonstrated that treatment with CH significantly ameliorated LPS-induced pathological changes in the lung. CH also attenuated LPS-induced W/D ratio, inflammatory cell infiltration. Meanwhile, LPS-induced Tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β) production and oxidative stress were markedly suppressed by CH. Furthermore, western blot showed that CH suppressed LPS-stimulated inflammation of RAW264.7 cells through activation of nuclear factor kappa-B (NF-κB) pathway. Knocking down of nuclear factor erythroid 2-related factor 2 (Nrf2) led to the reduction of nuclear translocation of the NF-κB p65, which triggered inflammation. These experimental results provided evidence that CH could be a potential therapeutic candidate for the intervention of ALI caused by LPS.

Antioxidant and Oxidative Stress: A Mutual Interplay in Age-Related Diseases

Aging is the progressive loss of organ and tissue function over time. Growing older is positively linked to cognitive and biological degeneration such as physical frailty, psychological impairment, and cognitive decline. Oxidative stress is considered as an imbalance between pro- and antioxidant species, which results in molecular and cellular damage. Oxidative stress plays a crucial role in the development of age-related diseases. Emerging research evidence has suggested that antioxidant can control the autoxidation by interrupting the propagation of free radicals or by inhibiting the formation of free radicals and subsequently reduce oxidative stress, improve immune function, and increase healthy longevity. Indeed, oxidation damage is highly dependent on the inherited or acquired defects in enzymes involved in the redox-mediated signaling pathways. Therefore, the role of molecules with antioxidant activity that promote healthy aging and counteract oxidative stress is worth to discuss further. Of particular interest in this article, we highlighted the molecular mechanisms of antioxidants involved in the prevention of age-related diseases. Taken together, a better understanding of the role of antioxidants involved in redox modulation of inflammation would provide a useful approach for potential interventions, and subsequently promoting healthy longevity.

Pioglitazone Represents an Effective Therapeutic Target in Preventing Oxidative/Inflammatory Cochlear Damage Induced by Noise Exposure

Recent progress in hearing loss research has provided strong evidence for the imbalance of cellular redox status and inflammation as common predominant mechanisms of damage affecting the organ of Corti including noise induced hearing loss. The discovery of a protective molecule acting on both mechanisms is challenging. The thiazolidinediones, a class of antidiabetic drugs including pioglitazone and rosiglitazone, have demonstrated diverse pleiotrophic effects in many tissues where they exhibit anti-inflammatory, anti-proliferative, tissue protective effects and regulators of redox balance acting as agonist of peroxisome proliferator-activated receptors (PPARs). They are members of the family of ligand regulated nuclear hormone receptors that are also expressed in several cochlear cell types, including the outer hair cells. In this study, we investigated the protective capacity of pioglitazone in a model of noise-induced hearing loss in Wistar rats and the molecular mechanisms underlying this protective effects. Specifically, we employed a formulation of pioglitazone in a biocompatible thermogel providing rapid, uniform and sustained inner ear drug delivery via transtympanic injection. Following noise exposure (120 dB, 10 kHz, 1 h), different time schedules of treatment were employed: we explored the efficacy of pioglitazone given immediately (1 h) or at delayed time points (24 and 48 h) after noise exposure and the time course and extent of hearing recovery were assessed. We found that pioglitazone was able to protect auditory function at the mid-high frequencies and to limit cell death in the cochlear basal/middle turn, damaged by noise exposure. Immunofluorescence and western blot analysis provided evidence that pioglitazone mediates both anti-inflammatory and anti-oxidant effects by decreasing NF-κB and IL-1β expression in the cochlea and opposing the oxidative damage induced by noise insult. These results suggest that intratympanic pioglitazone can be considered a valid therapeutic strategy for attenuating noise-induced hearing loss and cochlear damage, reducing inflammatory signaling and restoring cochlear redox balance.

Activation of Glutathione Peroxidase 4 as a Novel Anti-inflammatory Strategy

The anti-oxidative enzyme, glutathione peroxidase 4 (GPX4), helps to promote inflammation resolution by eliminating oxidative species produced by the arachidonic acid (AA) metabolic network. Up-regulating its activity has been proposed as a promising strategy for inflammation intervention. In the present study, we aimed to study the effect of GPX4 activator on the AA metabolic network and inflammation related pathways. Using combined computational and experimental screen, we identified a novel compound that can activate the enzyme activity of GPX4 by more than two folds. We further assessed its potential in a series of cellular assays where GPX4 was demonstrated to play a regulatory role. We are able to show that GPX4 activation suppressed inflammatory conditions such as oxidation of AA and NF-κB pathway activation. We further demonstrated that this GPX4 activator can decrease the intracellular ROS level and suppress ferroptosis. Our study suggests that GPX4 activators can be developed as anti-inflammatory or cyto-protective agent in lipid-peroxidation-mediated diseases.

Chelerythrine Attenuates the Inflammation of Lipopolysaccharide-Induced Acute Lung Inflammation Through NF-κB Signaling Pathway Mediated by Nrf2

Chelerythrine (CH), is a kind of benzo[c] phenanthridine alkaloid isolated from plants such as Chelidonium, with pharmacological activities as antitumor, antibiosis and anti-inflammation. However, few studies have demonstrated whether CH could protect against lipopolysaccharide (LPS)-induced acute lung injury (ALI), and the underlying mechanism is also uncertain. The purpose of the present study was to investigate the anti-inflammatory effects of CH on LPS-induced ALI in mice and in RAW264.7 cells. In this study, we demonstrated that treatment with CH significantly ameliorated LPS-induced pathological changes in the lung. CH also attenuated LPS-induced W/D ratio, inflammatory cell infiltration. Meanwhile, LPS-induced Tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β) production and oxidative stress were markedly suppressed by CH. Furthermore, western blot showed that CH suppressed LPS-stimulated inflammation of RAW264.7 cells through activation of nuclear factor kappa-B (NF-κB) pathway. Knocking down of nuclear factor erythroid 2-related factor 2 (Nrf2) led to the reduction of nuclear translocation of the NF-κB p65, which triggered inflammation. These experimental results provided evidence that CH could be a potential therapeutic candidate for the intervention of ALI caused by LPS.

Functions of transcription factors NF-κB and Nrf2 in the inhibition of LPS-stimulated cytokine release by the resin monomer HEMA

OBJECTIVE

Resin monomers like 2-hydroxyethyl methacrylate (HEMA) interfere with effects induced by stressors such as lipopolysaccharide (LPS) released from cariogenic microorganisms. In this study, mechanisms underlying monomer-induced inhibition of the LPS-stimulated secretion of inflammatory cytokines from immunocompetent cells were investigated.

METHODS

Secretion of pro-inflammatory cytokines TNF-α, IL-6 and the anti-inflammatory IL-10 from RAW264.7 mouse macrophages exposed to LPS and HEMA (0-6-8mM) was determined by ELISA. The formation of reactive oxygen (ROS) and nitrogen species (RNS) was determined by flow cytometry (FACS) after staining of cells with specific fluorescent dyes. Cell viability was analyzed by FACS, and protein expression was detected by Western blotting.

RESULTS

Secretion of TNF-α, IL-6 and IL-10 from LPS-stimulated cells increased after a 24h exposure. A HEMA-induced decrease in cytokine secretion resulted from the inhibition of LPS-stimulated NF-κB activation. Nuclear translocation of NF-κB was inhibited possibly as a result of enhanced levels of hydrogen peroxide (H₂O₂) and nitric oxide (NO) in HEMA-exposed cells. Oxidative stress caused by HEMA-induced formation of H₂O₂ and LPS-stimulated peroxynitrite (ONOO) also enhanced nuclear expression of Nrf2 as the major regulator of redox homeostasis, as well as Nrf2-controlled stress protein HO-1 to inhibit NF-κB activity. HEMA inhibited the LPS-stimulated expression of NOS (nitric oxide synthase) to produce NO but counteracted the expression of Nox2, which forms superoxide anions that combine with NO to peroxynitrite.

CONCLUSIONS

Resin monomers like HEMA inhibit LPS-stimulated NF-κB activation essential for cytokine release as a crucial response of immunocompetent cells of the dental pulp to invading cariogenic pathogens.

Alteration of Tumor Metabolism by CD4+ T Cells Leads to TNF-α-Dependent Intensification of Oxidative Stress and Tumor Cell Death

The inhibitory effects of cancer on T cell metabolism have been well established, but the metabolic impact of immunotherapy on tumor cells is poorly understood. Here, we developed a CD4+ T cell-based adoptive immunotherapy protocol that was curative for mice with implanted colorectal tumors. By conducting metabolic profiling on tumors, we show that adoptive immunotherapy profoundly altered tumor metabolism, resulting in glutathione depletion and accumulation of reactive oxygen species (ROS) in tumor cells. We further demonstrate that T cell-derived tumor necrosis factor alpha (TNF-α) can synergize with chemotherapy to intensify oxidative stress and tumor cell death in an NADPH (nicotinamide adenine dinucleotide phosphate hydrogen) oxidase-dependent manner. Reduction of oxidative stress, by preventing TNF-α-signaling in tumor cells or scavenging ROS, antagonized the therapeutic effects of adoptive immunotherapy. Conversely, provision of pro-oxidants after chemotherapy can partially recapitulate the antitumor effects of T cell transfer. These findings imply that reinforcing tumor oxidative stress represents an important mechanism underlying the efficacy of adoptive immunotherapy.

Improving knowledge on the activation of bone marrow fibroblasts in MGUS and MM disease through the automatic extraction of genes via a nonnegative matrix factorization approach on gene expression profiles

Background

Multiple myeloma (MM) is a cancer of terminally differentiated plasma that is part of a spectrum of blood diseases. The role of the micro-environment is crucial for MM clonal evolution.

Methods

This paper describes the analysis carried out on a limited number of genes automatically extracted by a nonnegative matrix factorization (NMF) based approach from gene expression profiles of bone marrow fibroblasts of patients with monoclonal gammopathy of undetermined significance (MGUS) and MM.

Results

Automatic exploration through NMF, combined with a motivated post-processing procedure and a pathways analysis of extracted genes, allowed to infer that a functional switch is required to lead fibroblasts to acquire pro-tumorigenic activity in the progression of the disease from MGUS to MM.

Conclusion

The extracted biologically relevant genes may be representative of the considered clinical conditions and may contribute to a deeper understanding of tumor behavior.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1589-1) contains supplementary material, which is available to authorized users.

Dysregulation of Mesenchymal Stromal Cell Antioxidant Responses in Progressive Multiple Sclerosis

The potential of autologous cell-based therapies including those using multipotent mesenchymal stromal cells (MSCs) is being investigated for multiple sclerosis (MS) and other neurological conditions. However, the phenotype of MSC in neurological diseases has not been fully characterized. We have previously shown that MSC isolated from patients with progressive MS (MS-MSC) have reduced expansion potential, premature senescence, and reduced neuroprotective potential in vitro. In view of the role of antioxidants in ageing and neuroprotection, we examined the antioxidant capacity of MS-MSC demonstrating that MS-MSC secretion of antioxidants superoxide dismutase 1 (SOD1) and glutathione S-transferase P (GSTP) is reduced and correlates negatively with the duration of progressive phase of MS. We confirmed reduced expression of SOD1 and GSTP by MS-MSC along with reduced activity of SOD and GST and, to examine the antioxidant capacity of MS-MSC under conditions of nitrosative stress, we established an in vitro cell survival assay using nitric oxide-induced cell death. MS-MSC displayed differential susceptibility to nitrosative stress with accelerated senescence and greater decline in expression of SOD1 and GSTP in keeping with reduced expression of master regulators of antioxidant responses nuclear factor erythroid 2-related factor 2 and peroxisome proliferator-activated receptor gamma coactivator 1-α. Our results are compatible with dysregulation of antioxidant responses in MS-MSC and have significant implications for development of autologous MSC-based therapies for MS, optimization of which may require that these functional deficits are reversed. Furthermore, improved understanding of the underlying mechanisms may yield novel insights into MS pathophysiology and biomarker identification. Stem Cells Translational Medicine 2018;7:748-758.

Klotho protects human monocytes from LPS-induced immune impairment associated with immunosenescent-like phenotype

In this study, we provide a new evidence on immunosenescent-like phenotype induction in low density monocytes due to the long-term treatment with lipopolysaccharide (LPS). We show that LPS caused oxidative and nitrosative stress through zinc downregulation and calcium accumulation. In turn, increased amounts of ROS/RNS and pro-inflammatory cytokines TNFα, IL-1β, IL-6 led to the irreversible DNA damage, persistent DDR activation, proliferation inhibition, reduction in cell growth and immune impairment. Furthermore, we provide evidence that klotho reduced levels of ROS/RNS and pro-inflammatory cytokines as well as upregulated secretion of anti-inflammatory IL-10 in LPS-treated monocytes, thus the observed DNA damage was less severe, promptly and properly fixed and cells quickly resumed normal proliferation and maintained their immune functionality. Therefore, klotho protein could be considered as a protective factor against immunosenescent-like phenotype in monocytes an issue relevant to many immune disorders.

Asperuloside and Asperulosidic Acid Exert an Anti-Inflammatory Effect via Suppression of the NF-κB and MAPK Signaling Pathways in LPS-Induced RAW 264.7 Macrophages

Hedyotis diffusa is a folk herb that is used for treating inflammation-related diseases in Asia. Previous studies have found that iridoids in H. diffusa play an important role in its anti-inflammatory activity. This study aimed to investigate the anti-inflammatory effect and potential mechanism of five iridoids (asperuloside (ASP), asperulosidic acid (ASPA), desacetyl asperulosidic acid (DAA), scandoside methyl ester (SME), and E-6-O-p-coumaroyl scandoside methyl ester (CSME)) that are presented in H. diffusa using lipopolysaccharide (LPS)-induced RAW 264.7 cells. ASP and ASPA significantly decreased the production of nitric oxide (NO), prostaglandin E₂ (PGE₂), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in parallel with the inhibition of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-6 mRNA expression in LPS-induced RAW 264.7 cells. ASP treatment suppressed the phosphorylation of the inhibitors of nuclear factor-kappaB alpha (IκB-α), p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK). The inhibitory effect of ASPA was similar to that of ASP, except for p38 phosphorylation. In summary, the anti-inflammatory effects of ASP and ASPA are related to the inhibition of inflammatory cytokines and mediators via suppression of the NF-κB and mitogen-activated protein kinase (MAPK) signaling pathways, which provides scientific evidence for the potential application of H. diffusa.

Kobophenol A Isolated from Roots of Caragana sinica (Buc'hoz) Rehder Exhibits Anti-inflammatory Activity by Regulating NF-κB Nuclear Translocation in J774A.1 Cells

Kobophenol A (KPA) is a biologically active natural compound isolated from the roots of Caragana sinica (Buc'hoz) Rehder (C. sinica). However, the anti-inflammatory effects of KPA have not been reported. This study aims to find out whether KPA isolated from roots of C. sinica can act as a potential substance on inflammation and analyze the molecular mechanism using the lipopolysaccharide (LPS)-stimulated J774 A.1 macrophage cell line. We showed that KPA treatment significantly suppressed the production of nitric oxide (NO) by inhibiting inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner without cytotoxicity. In the KPA also inhibited pro-inflammatory cytokine gene expression and production, such as interleukin-1β (IL-1β) and interleukin-6 (IL-6) in LPS-stimulated J774 A.1 cells. As continuing study on the mechanisms involved, we confirmed that these effects of KPA were related to the inhibition of nuclear factor-κB (NF-κB) pathway including the suppression of IκB kinase α/β (IKKα/β) phosphorylation and translocation of NF-κB into the nucleus. Taken together, the present study is the first to demonstrate that KPA isolated from C. sinica suppresses the expression of inflammatory mediators and cytokines by inhibiting NF-κB nuclear translocation in LPS-stimulated J774 A.1 macrophages. KPA may be a potential candidate for the treatment of inflammatory diseases in the future.

Reactive Oxygen Species Deficiency Due to Ncf1-Mutation Leads to Development of Adenocarcinoma and Metabolomic and Lipidomic Remodeling in a New Mouse Model of Dextran Sulfate Sodium-Induced Colitis

Inflammatory bowel disease is characterized by chronic relapsing idiopathic inflammation of the gastrointestinal tract and persistent inflammation. Studies focusing on the immune-regulatory function of reactive oxygen species (ROS) are still largely missing. In this study, we analyzed an ROS-deficient mouse model leading to colon adenocarcinoma. Colitis was induced with dextran sulfate sodium (DSS) supplied via the drinking water in wild-type (WT) and Ncf1-mutant (Ncf1) B10.Q mice using two different protocols, one mimicking recovery after acute colitis and another simulating chronic colitis. Disease progression was monitored by evaluation of clinical parameters, histopathological analysis, and the blood serum metabolome using ¹H nuclear magnetic resonance spectroscopy. At each experimental time point, colons and spleens from some mice were removed for histopathological analysis and internal clinical parameters. Clinical scores for weight variation, stool consistency, colorectal bleeding, colon length, and spleen weight were significantly worse for Ncf1 than for WT mice. Ncf1 mice with only a 7-day exposure to DSS followed by a 14-day resting period developed colonic distal high-grade dysplasia in contrast to the low-grade dysplasia found in the colon of WT mice. After a 21-day resting period, there was still β-catenin-rich inflammatory infiltration in the Ncf1 mice together with high-grade dysplasia and invasive well-differentiated adenocarcinoma, while in the WT mice, high-grade dysplasia was prominent without malignant invasion and only low inflammation. Although exposure to DSS generated less severe histopathological changes in the WT group, the blood serum metabolome revealed an increased fatty acid content with moderate-to-strong correlations to inflammation score, weight variation, colon length, and spleen weight. Ncf1 mice also displayed a similar pattern but with lower coefficients and showed consistently lower glucose and/or higher lactate levels which correlated with inflammation score, weight variation, and spleen weight. In our novel, DSS-induced colitis animal model, the lack of an oxidative burst ROS was sufficient to develop adenocarcinoma, and display altered blood plasma metabolic and lipid profiles. Thus, oxidative burst seems to be necessary to prevent evolution toward cancer and may confer a protective role in a ROS-mediated self-control mechanism.

Increased Tim-3 expression alleviates liver injury by regulating macrophage activation in MCD-induced NASH mice

As an immune checkpoint, Tim-3 plays roles in the regulation of both adaptive and innate immune cells including macrophages and is greatly involved in chronic liver diseases. However, the precise roles of Tim-3 in nonalcoholic steatohepatitis (NASH) remain unstated. In the current study, we analyzed Tim-3 expression on different subpopulations of liver macrophages and further investigated the potential roles of Tim-3 on hepatic macrophages in methionine and choline-deficient diet (MCD)-induced NASH mice. The results of flow cytometry demonstrated the significantly increased expression of Tim-3 on all detected liver macrophage subsets in MCD mice, including F4/80⁺CD11b⁺, F4/80⁺CD68⁺, and F4/80⁺CD169⁺ macrophages. Remarkably, Tim-3 knockout (KO) significantly accelerated MCD-induced liver steatosis, displaying higher serum ALT, larger hepatic vacuolation, more liver lipid deposition, and more severe liver fibrosis. Moreover, compared with wild-type C57BL/6 mice, Tim-3 KO MCD mice demonstrated an enhanced expression of NOX2, NLRP3, and caspase-1 p20 together with increased generation of IL-1β and IL-18 in livers. In vitro studies demonstrated that Tim-3 negatively regulated the production of reactive oxygen species (ROS) and related downstream pro-inflammatory cytokine secretion of IL-1β and IL-18 in macrophages. Exogenous administration of N-Acetyl-L-cysteine (NAC), a small molecular inhibitor of ROS, remarkably suppressed caspase-1 p20 expression and IL-1β and IL-18 production in livers of Tim-3 KO mice, thus significantly reducing the severity of steatohepatitis induced by MCD. In conclusion, Tim-3 is a promising protector in MCD-induced steatohepatitis by controlling ROS and the associated pro-inflammatory cytokine production in macrophages.

Maternal late-gestation metabolic stress is associated with changes in immune and metabolic responses of dairy calves

Metabolic stress in periparturient dairy cows is characterized by excessive lipid mobilization, inflammation, and oxidative stress that is associated with immune dysfunction. Thus, metabolic stress around the time calving is linked to the development of various early-lactation health disorders. Maternal status during late pregnancy can have carryover effects on several health and production variables of neonatal calves. However, the effects of metabolic stress during gestation on metabolic and immune responses of newborn calves remain unknown. Thus, we aimed to investigate whether metabolic stress in late-gestation dairy cows is associated with changes in the metabolic and immune responses of their offspring during the first month of life. Holstein-Friesian cows (n = 12) were blood sampled at 28 and 15 d before expected calving. The average between these 2 sampling points in the serum concentrations of nonesterified fatty acids (NEFA), haptoglobin (Hp), and oxidant status index (OSi)-defined as the ratio between reactive oxygen and nitrogen species and total antioxidant potential-were calculated as indicators of the degree of lipid mobilization, inflammation, and oxidant status (OS), respectively. Calves were subsequently divided into groups (n = 6 each) according to their dams' high or low degree of lipid mobilization, inflammation, and OS. The metabolic responses of calves in each of these groups were compared weekly throughout their first month of life by assessing serum concentration of NEFA, Hp, and OSi. Additionally, whole blood was obtained from calves at each sampling period and subjected to a lipopolysaccharide (LPS)-stimulated tumor necrosis factor-α (TNF-α) production assay to assess cell-mediated innate immunity against induced inflammatory responses, using high (5 μg/mL of blood) and low (10 ng/mL) concentrations of LPS. Calves born to cows with higher NEFA or OSi showed lower body weight at birth and throughout the study, whereas no association between any of the maternal groups and average daily gain at 4 wk of age was identified. Serum concentrations of reactive oxygen and nitrogen species were higher in calves exposed to higher maternal NEFA concentrations or OSi when compared with calves born to cows with lower values of these biomarkers. Calves exposed to high maternal OS also had higher circulating concentrations of Hp and TNF-α, indicating greater basal inflammatory responses when compared with calves born to cows with a lower OSi. In contrast, LPS-induced inflammatory responses were less robust in calves exposed to higher maternal biomarkers of inflammation or OS, suggesting compromised immune responses to microbial agonists. Collectively, these data suggest that prenatal exposure to maternal parameters of metabolic stress may adversely affect some metabolic and inflammatory responses of the offspring that could influence disease susceptibility.

dCK negatively regulates the NRF2/ARE axis and ROS production in pancreatic cancer

Objectives

Decreased deoxycytidine kinase (dCK) expression is a reported indicator of gemcitabine efficacy in pancreatic cancer, due to the impact of this kinase on gemcitabine metabolism. The transcription factor NF‐E2 p45‐related factor 2 (NRF2, also called Nfe2l2), a master regulator of redox homoeostasis, has been reported to tightly control the expression of numerous ROS‐detoxification genes and participates in drug resistance. However, the contribution of dCK to the NRF2 signalling axis has seldom been discussed and needs investigation.

Materials and methods

By overexpressing dCK in pancreatic cancer cells, we assessed the impact of dCK on NRF2 transcriptional activity. Furthermore, we measured the impact of dCK expression on the intracellular redox balance and reactive oxygen species (ROS) production. By utilizing immunohistochemical staining and tissues from pancreatic cancer patients, we assessed the correlation between dCK and NRF2 expression. Through proliferation and metastasis assays, we examined the impact of dCK expression on cell proliferation and metastasis.

Results

dCK negatively regulates NRF2 transcriptional activity, leading to the decreased expression of ARE‐driven antioxidant genes. In addition, dCK negatively regulates intracellular redox homoeostasis and ROS production. Negative correlations between dCK and NRF2 levels in pancreatic cancer cell lines and patient samples were observed. In vitro cell line studies suggested that dCK negatively regulated proliferation and metastasis.

Conclusion

Decreased dCK expression promotes NRF2‐driven antioxidant transcription, which further enhances gemcitabine treatment resistance, forming a feedback loop.

ROS and RNS signalling: adaptive redox switches through oxidative/nitrosative protein modifications

Over the last decade, a dual character of cell response to oxidative stress, eustress versus distress, has become increasingly recognized. A growing body of evidence indicates that under physiological conditions, low concentrations of reactive oxygen and nitrogen species (RONS) maintained by the activity of endogenous antioxidant system (AOS) allow reversible oxidative/nitrosative modifications of key redox-sensitive residues in regulatory proteins. The reversibility of redox modifications such as Cys S-sulphenylation/S-glutathionylation/S-nitrosylation/S-persulphidation and disulphide bond formation, or Tyr nitration, which occur through electrophilic attack of RONS to nucleophilic groups in amino acid residues provides redox switches in the activities of signalling proteins. Key requirement for the involvement of the redox modifications in RONS signalling including ROS-MAPK, ROS-PI3K/Akt, and RNS-TNF-α/NF-kB signalling is their specificity provided by a residue microenvironment and reaction kinetics. Glutathione, glutathione peroxidases, peroxiredoxins, thioredoxin, glutathione reductases, and glutaredoxins modulate RONS level and cell signalling, while some of the modulators (glutathione, glutathione peroxidases and peroxiredoxins) are themselves targets for redox modifications. Additionally, gene expression, activities of transcription factors, and epigenetic pathways are also under redox regulation. The present review focuses on RONS sources (NADPH-oxidases, mitochondrial electron-transportation chain (ETC), nitric oxide synthase (NOS), etc.), and their cross-talks, which influence reversible redox modifications of proteins as physiological phenomenon attained by living cells during the evolution to control cell signalling in the oxygen-enriched environment. We discussed recent advances in investigation of mechanisms of protein redox modifications and adaptive redox switches such as MAPK/PI3K/PTEN, Nrf2/Keap1, and NF-κB/IκB, powerful regulators of numerous physiological processes, also implicated in various diseases.

Designer exosomes produced by implanted cells intracerebrally deliver therapeutic cargo for Parkinson's disease treatment

Exosomes are cell-derived nanovesicles (50-150 nm), which mediate intercellular communication, and are candidate therapeutic agents. However, inefficiency of exosomal message transfer, such as mRNA, and lack of methods to create designer exosomes have hampered their development into therapeutic interventions. Here, we report a set of EXOsomal transfer into cells (EXOtic) devices that enable efficient, customizable production of designer exosomes in engineered mammalian cells. These genetically encoded devices in exosome producer cells enhance exosome production, specific mRNA packaging, and delivery of the mRNA into the cytosol of target cells, enabling efficient cell-to-cell communication without the need to concentrate exosomes. Further, engineered producer cells implanted in living mice could consistently deliver cargo mRNA to the brain. Therapeutic catalase mRNA delivery by designer exosomes attenuated neurotoxicity and neuroinflammation in in vitro and in vivo models of Parkinson's disease, indicating the potential usefulness of the EXOtic devices for RNA delivery-based therapeutic applications.