A proinflammatory activity of interleukin 8 in human skin: expression of the inducible nitric oxide synthase in psoriatic lesions and cultured keratinocytes

Cytokines in psoriasis: From pathogenesis to targeted therapy

Psoriasis is a multifactorial disease that affects 0.84% of the global population and it can be associated with disabling comorbidities. As patients present with thick scaly lesions, psoriasis was long believed to be a disorder of keratinocytes. Psoriasis is now understood to be the outcome of the interaction between immunological and environmental factors in individuals with genetic predisposition. While it was initially thought to be solely mediated by cytokines of type-1 immunity, namely interferon-γ, interleukin-2, and interleukin-12 because it responds very well to cyclosporine, a reversible IL-2 inhibitor; the discovery of Th-17 cells advanced the understanding of the disease and helped the development of biological therapy. This article aims to provide a comprehensive review of the role of cytokines in psoriasis, highlighting areas of controversy and identifying the connection between cytokine imbalance and disease manifestations. It also presents the approved targeted treatments for psoriasis and those currently under investigation.

Inhibition of the Akt/NF-κB pathway is involved in the anti-gastritis effects of an ethanolic extract of the rhizome of Atractylodes macrocephala

ETHNOPHARMACOLOGICAL RELEVANCE

Gastritis can lead to ulcers and the development of gastric cancer. The rhizome of Atractylodes macrocephala Koidz. (Asteraceae), a traditional Chinese medicinal herb, is prescribed for the treatment of gastric disorders, hepatitis and rheumatism. Its bio-active compounds are considered to be particularly effective in this regard. However, the molecular processes of the herb's anti-inflammatory activity remain obscure. This study elucidates a mechanism upon which an ethanolic extract of this herb (Am-EE) exerts anti-inflammation effects in RAW264.7 macrophage cells (RAW cells) stimulated by lipopolysaccharide (LPS) treatment and HCl Ethanol-stimulated gastritis rats.

AIM OF THE STUDY

To investigate the anti-gastritis activities of Am-EE and explore the mode of action.

MATERIALS AND METHODS

Ethanol (95%) was used to prepare Am-EE. The quality of the extract was monitored by HPLC analysis. The in vivo effects of this extract were examined in an HCl Ethanol-stimulated gastritis rat model, while LPS-stimulated RAW cells were used for in vitro assays. Cell viability and nitric oxide (NO) production were observed by MTT and Griess assays. Real-time PCR was used to examine mRNA expression. The PGE₂ ELISA kit was employed to detect prostaglandin E₂ (PGE₂). Enzyme activities and protein contents were examined by immunoblotting. Luciferase reporter gene assays (LRA) were employed to observe nuclear transcription factor (NF)-κB activity. The SPSS (SPSS Inc., Chicago, Illinois, United States) application was used for statistical examination.

RESULTS

HPLC analysis indicates that Am-EE contains atractylenolide-1 (AT-1, 1.33%, w/w) and atractylenolide-2 (AT-2, 1.25%, w/w) (Additional Figure. A1). Gastric tissue damage (induced by HCl Ethanol) was significantly decreased in SD rats following intra-gastric application of 35 mg/kg Am-EE. Indistinguishable to the anti-inflammation effects of 35 mg/kg ranitidine (gastric medication). Am-EE treatment also reduced LPS-mediated nitric oxide (NO) and prostaglandin E₂ (PGE₂) production. The mRNA and protein synthesis of inducible cyclooxygenase (COX)-2 and NO synthase (iNOS) was down-regulated following treatment in RAW cells. Am-EE decreased NF-κB (p50) nuclear protein levels and inhibited NF-κB-stimulated LRA activity in RAW cells. Lastly, Am-EE decreased the up-regulated levels of phosphorylated IκBα and Akt proteins in rat stomach lysates and in LPS challenged RAW cell samples.

CONCLUSION

Our study illustrates that Am-EE suppresses the Akt/IκBα/NF-κB pathway and exerts an anti-inflammatory effect. These novel conclusions provide a pharmacological basis for the clinical use of the A. macrocephala rhizome in the treatment and prevention of gastritis and gastric cancer.

Multi-Organ-on-a-Chip for Realization of Gut-Skin Axis

The concept of physiological link between the gut and the skin, known as the gut-skin axis, has been gaining more evidence recently. Although experimental data from animal and human studies support the existence of the gut-skin axis, in vitro model platforms that can test the hypothesis are lacking. Organ-on-a-chip offers the possibility of connecting different tissues and recapitulating interactions between them. In this study, we report a multi-organ chip that can capture the basic inter-organ communication between the gut and the skin. Its modular design enables separate culture and differentiation of the gut and skin tissues, and after assembly the two organs are connected via microfluidic channels than enables perfusion and mass transfer. We showed that the impairment of the gut barrier function exacerbated the adverse effect of fatty acids on skin cells, with decreased viability, increased level of cytokine secretion and human β-defensin-2 (hBD-2), an inflammatory dermal disease marker. Based on these results, we believe that our multi-organ chip can be a novel in vitro platform for recapitulating complex mechanisms underlying the gut-skin axis. This article is protected by copyright. All rights reserved.

Regulatory Role of Nitric Oxide in Cutaneous Inflammation

Nitric oxide (NO), a signaling molecule, regulates biological functions in multiple organs/tissues, including the epidermis, where it impacts permeability barrier homeostasis, wound healing, and antimicrobial defense. In addition, NO participates in cutaneous inflammation, where it exhibits pro-inflammatory properties via the cyclooxygenase/prostaglandin pathway, migration of inflammatory cells, and cytokine production. Yet, NO can also inhibit cutaneous inflammation through inhibition of T cell proliferation and leukocyte migration/infiltration, enhancement of T cell apoptosis, as well as through down-regulation of cytokine production. Topical applications of NO-releasing products can alleviate atopic dermatitis in humans and in murine disease models. The underlying mechanisms of these discrepant effects of NO on cutaneous inflammation remain unknown. In this review, we briefly review the regulatory role of NO in cutaneous inflammation and its potential, underlying mechanisms.

Identification of Cell Markers and Their Expression Patterns in Skin Based on Single-Cell RNA-Sequencing Profiles

Atopic dermatitis and psoriasis are members of a family of inflammatory skin disorders. Cellular immune responses in skin tissues contribute to the development of these diseases. However, their underlying immune mechanisms remain to be fully elucidated. We developed a computational pipeline for analyzing the single-cell RNA-sequencing profiles of the Human Cell Atlas skin dataset to investigate the pathological mechanisms of skin diseases. First, we applied the maximum relevance criterion and the Boruta feature selection method to exclude irrelevant gene features from the single-cell gene expression profiles of inflammatory skin disease samples and healthy controls. The retained gene features were ranked by using the Monte Carlo feature selection method on the basis of their importance, and a feature list was compiled. This list was then introduced into the incremental feature selection method that combined the decision tree and random forest algorithms to extract important cell markers and thus build excellent classifiers and decision rules. These cell markers and their expression patterns have been analyzed and validated in recent studies and are potential therapeutic and diagnostic targets for skin diseases because their expression affects the pathogenesis of inflammatory skin diseases.

Tapping basement membrane motifs: Oral junctional epithelium for surface-mediated soft tissue attachment to prevent failure of percutaneous devices

Teeth, long-lasting percutaneous organs, feature soft tissue attachment through adhesive structures, hemidesmosomes, in the junctional epithelium basement membrane adjacent to teeth. This soft tissue attachment prevents bacterial infection of the tooth despite the rich - and harsh - microbial composition of the oral cavity. Conversely, millions of percutaneous devices (catheters, dental, and orthopedic implants) fail from infection yearly. Standard of care antibiotic usage fuels antimicrobial resistance and is frequently ineffective. Infection prevention strategies, like for dental implants, have failed in generating durable soft tissue adhesion - like that seen with the tooth - to prevent bacterial colonization at the tissue-device interface. Here, inspired by the impervious natural attachment of the junctional epithelium to teeth, we synthesized four cell adhesion peptide (CAPs) nanocoatings, derived from basement membranes, to promote percutaneous device soft tissue attachment. The two leading nanocoatings upregulated integrin-mediated hemidesmosomes, selectively increased keratinocyte proliferation compared to fibroblasts, which cannot form hemidesmosomes, and expression of junctional epithelium adhesive markers. CAP nanocoatings displayed marked durability under simulated clinical conditions and the top performer CAP nanocoating was validated in a percutaneous implant murine model. Basement membrane CAP nanocoatings, inspired by the tooth and junctional epithelium, may provide an alternative anti-infective strategy for percutaneous devices to mitigate the worldwide threat of antimicrobial resistance. STATEMENT OF SIGNIFICANCE: Prevention and management of medical device infection is a significant healthcare challenge. Overzealous antibiotic use has motivated alternative material innovations to prevent infection. Here, we report implant cell adhesion peptide nanocoatings that mimic a long-lasting, natural "medical device," the tooth, through formation of cell adhesive structures called hemidesmosomes. Such nanocoatings sidestep the use of antimicrobial or antibiotic elements to form a soft-tissue seal around implants. The top performing nanocoatings prompted expression of hemidesmosomes and defensive factors to mimic the tooth and was validated in an animal model. Application of cell adhesion peptide nanocoatings may provide an alternative to preventing, rather that necessarily treating, medical device infection across a range of device indications, like dental implants.

Insights into the functional role of grass carp IL-8 in head kidney leukocytes: pro-inflammatory effects and signalling mechanisms

Interleukin-8 (IL-8) is a critical chemokine regulating immune cells' chemotaxis as well as their physiological or pathological activations. In fish cells, recombinant IL-8 proteins induced transcriptions of pro-inflammatory cytokines. Nonetheless, the exact mechanisms underlying the function of fish IL-8 as a pro-inflammatory cytokine are still unclear. In this paper, the authors first prepared recombinant grass carp IL-8 (rgcIL-8) using an Escherichia coli expression system, and later confirmed rgcIL-8 increased gene expression of il8, il1β and tumour necrosis factor alpha (tnfα) in grass carp head kidney leukocytes (HKLs). Using signalling pathway inhibitors, the authors showed that rgcIL-8 regulated transcriptions of pro-inflammatory cytokines via MAPK and/or NF-κB signalling pathways. They cloned gcIL-8-specific receptor CXCR1 and subsequently discovered that gcIL-8 could increase the activity of NF-κB and the transcription of IL-1β via CXCR1. Simultaneously, antibody neutralization assay showed that endogenous IL-8 is partially relevant to the self-regulation of IL-1β. Moreover, rgcIL-8 led to the expression of inducible nitric oxide synthase gene, causing an accumulation of nitric oxide in the culture medium of HKLs, suggesting the potential of gcIL-8 to mediate inflammatory response. This study not only enriched the function of IL-8 in teleost but also revealed it as a potential target for the inflammatory control in grass carp.

The anti-inflammatory effects of an ethanolic extract of the rhizome of Atractylodes lancea, involves Akt/NF-κB signaling pathway inhibition

ETHNOPHARMACOLOGICAL RELEVANCE

The dried rhizome of Atractylodes lancea (Thumb.) DC. (Compositae) has been prescribed in folk medicine for the management of various inflammatory conditions such as rheumatic diseases, gastritis and hepatitis. However, the molecular mechanisms underlying the beneficial properties of this herb remain elusive.

AIM OF THE STUDY

In this study, we investigated the anti-gastritis activities of Al-EE (an ethanolic extract of the herb) and explored the mechanism of action.

MATERIALS AND METHODS

An ethanolic extract of the Atractylodes lancea (Thumb.) DC. (Compositae) rhizome, Al-EE, was prepared with ethanol (95%) and quality controlled using HPLC analysis. To determine the in vivo effects of this extract, we utilised a HCl/EtOH-induced gastritis rat model. In vitro assays were carried out using a lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cell model. MTT assays were used to examine cell viability, while Griess assays were carried out to measure nitric oxide (NO) production. Messenger RNA expression was examined by real-time PCR. Prostaglandin E₂ (PGE₂) production was examined using ELISA assays. To examine protein expression and enzymatic activities, we employed western blot analysis. Nuclear transcription factor (NF)-κB activity was determined by Luciferase reporter assays.

RESULTS

The content of atractylenolide (AT)-1 and AT-2 in Al-EE was 0.45% and 5.07% (w/w), respectively (Supplementary Fig. 1). Al-EE treatment suppressed the production of NO and PGE₂, reduced the mRNA expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2 and tumor necrosis factor (TNF)-α, while also reducing the protein levels of iNOS and COX-2 in RAW264.7 macrophage cells. Furthermore, Al-EE inhibited the nuclear protein levels of NF-κB (p65) and NF-κB-driven luciferase reporter gene activity in RAW264.7 macrophage cells. Critically, intra-gastric injection of Al-EE (25 mg/kg) attenuated HCl/EtOH-induced gastric damage in SD rats, while the phosphorylation of Akt and IκBα was suppressed by Al-EE in vitro and in vivo.

CONCLUSION

In summary, Al-EE has significant anti-gastritis effects in vivo and in vitro, which can be associated with the inhibition of the Akt/IκBα/NF-κB signalling pathway. This mechanistic finding provides a pharmacological basis for the use of the A. lancea rhizome in the clinical treatment of various inflammatory conditions.

Insights into interplay of immunopathophysiological events and molecular mechanistic cascades in psoriasis and its associated comorbidities

Psoriasis is an inflammatory skin disease with complex pathogenesis and multiple etiological factors. Besides the essential role of autoreactive T cells and constellation of cytokines, the discovery of IL-23/Th17 axis as a central signaling pathway has unraveled the mechanism of accelerated inflammation in psoriasis. This has provided insights into psoriasis pathogenesis and revolutionized the development of effective biological therapies. Moreover, genome-wide association studies have identified several candidate genes and susceptibility loci associated with this disease. Although involvement of cellular innate and adaptive immune responses and dysregulation of immune cells have been implicated in psoriasis initiation and maintenance, there is still a lack of unifying mechanism for understanding the pathogenesis of this disease. Emerging evidence suggests that psoriasis is a high-mortality disease with additional burden of comorbidities, which adversely affects the treatment response and overall quality of life of patients. Furthermore, changing trends of psoriasis-associated comorbidities and shared patterns of genetic susceptibility, risk factors and pathophysiological mechanisms manifest psoriasis as a multifactorial systemic disease. This review highlights the recent progress in understanding the crucial role of different immune cells, proinflammatory cytokines and microRNAs in psoriasis pathogenesis. In addition, we comprehensively discuss the involvement of various complex signaling pathways and their interplay with immune cell markers to comprehend the underlying pathophysiological mechanism, which may lead to exploration of new therapeutic targets and development of novel treatment strategies to reduce the disastrous nature of psoriasis and associated comorbidities.

Inhibition of inflammatory response in human keratinocytes by magnetic nanoparticles functionalized with PBP10 peptide derived from the PIP2-binding site of human plasma gelsolin

Background

Human plasma gelsolin (pGSN) is a multifunctional actin-binding protein involved in a variety of biological processes, including neutralization of pro-inflammatory molecules such as lipopolysaccharide (LPS) and lipoteichoic acid (LTA) and modulation of host inflammatory response. It was found that PBP10, a synthetic rhodamine B-conjugated peptide, based on the phosphoinositide-binding site of pGSN, exerts bactericidal activity against Gram-positive and Gram-negative bacteria, interacts specifically with LPS and LTA, and limits microbial-induced inflammatory effects. The therapeutic efficiency of PBP10 when immobilized on the surface of iron oxide-based magnetic nanoparticles was not evaluated, to date.

Results

Using the human keratinocyte cell line HaCaT stimulated by bacterially-derived LPS and LTA as an in vitro model of bacterial infection, we examined the anti-inflammatory effects of nanosystems consisting of iron oxide-based magnetic nanoparticles with aminosilane (MNP@NH₂) or gold shells (MNP@Au) functionalized by a set of peptides, derived from the phosphatidylinositol 4,5-bisphosphate (PIP2)-binding site of the human plasma protein gelsolin, which also binds LPS and LTA. Our results indicate that these nanosystems can kill both Gram-positive and Gram-negative bacteria and limit the production of inflammatory mediators, including nitric oxide (NO), reactive oxygen species (ROS), and interleukin-8 (IL-8) in the response to heat-killed microbes or extracted bacterial cell wall components. The nanoparticles possess the potential to improve therapeutic efficacy and are characterized by lower toxicity and improved hemocompatibility when compared to free peptides. Atomic force microscopy (AFM) showed that these PBP10-based nanosystems prevented changes in nanomechanical properties of cells that were otherwise stimulated by LPS.

Conclusions

Neutralization of endotoxemia-mediated cellular effects by gelsolin-derived peptides and PBP10-containing nanosystems might be considered as potent therapeutic agents in the improved therapy of bacterial infections and microbial-induced inflammation.

An ethanol extract of the rhizome of Atractylodes chinensis exerts anti-gastritis activities and inhibits Akt/NF-κB signaling

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizome of Atractylodes chinensis (DC.) kodiz (Compositae) has traditionally been used to treat inflammatory disorders such as arthritis and stomach ache, but scanted report has been issued on its anti-inflammatory mechanisms.

AIM OF THE STUDY

Here, we investigated the anti-gastritis activities and explored the mechanism of action of an ethanolic extract of the herb (Ac-EE).

MATERIALS AND METHODS

Ac-EE was prepared with 95% ethanol. To determine its in vivo effects, we employed an HCl/EtOH-induced gastritis rat model. We used a lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage model for in vitro assays. Griess and MTT assays were used to measure nitric oxide (NO) production and cell viability, respectively. We used real-time PCR to determine mRNA levels. To measure prostaglandin E₂ (PGE₂) production we used a PGE₂ EIA kit. To estimate protein levels and enzyme activities, we employed immunoblotting. Luciferase assays were used to examine nuclear transcription factor (NF)-κB activities.

RESULTS

Intragastric administration of Ac-EE (30 mg/kg) ameliorated HCl/EtOH-induced stomach tissue damages in SD rats. Ac-EE inhibited the levels of NO and PGE_2, down regulated mRNA and protein levels of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2. Ac-EE suppressed the nuclear level of NF-κB (p50), and inhibited NF-κB luciferase activity. The Phosphorylation of Akt and IκBα was also inhibited by Ac-EE both in vivo and in vitro.

CONCLUSION

Ac-EE treatment exerts an anti-gastritis effect in rats. Inhibition of the Akt/IκBα/NF-κB signaling pathway is associated with this effect, providing a pharmacological basis for the clinical application of the rhizome of A. chinensis in the treatment of inflammatory diseases.

Psoriasis and Respiratory Comorbidities: The Added Value of Fraction of Exhaled Nitric Oxide as a New Method to Detect, Evaluate, and Monitor Psoriatic Systemic Involvement and Therapeutic Efficacy

Psoriasis is a chronic inflammatory systemic disease characterized by a wide range of comorbidities. Respiratory comorbidities are currently poorly characterized and with discordant results. The systemic state of inflammation caused by psoriasis acts de novo on respiratory tissues and amplifies preexisting inflammation from asthma or chronic obstructive pulmonary disease. Because the lungs act as a gas exchanger between the internal and external environment, the impact of chronic psoriasis inflammation may be easily assessed through the analysis of exhaled breath. The fraction of exhaled nitric oxide test (FeNO) is a potential noninvasive solution that can provide quantitative and qualitative indices of respiratory airway inflammation. FeNO is routinely used to screen and manage asthmatic patients. Recent pilot studies contain encouraging data that underscore its possible use with systemic inflammatory nonpulmonary diseases, such as psoriasis. FeNO may therefore be a useful tool to evaluate underestimated airway inflammation and at the same time globally evaluate the impact of systemically antipsoriatic therapies.

Dipterocarpus obtusifolius attenuates the effects of lipopolysaccharide‑induced inflammatory response in RAW264.7 macrophages

Dipterocarpus obtusifolius has been traditionally used as a herbal medicine and is considered to have anticancer properties. The biological activity of D. obtusifolius in inflammation and the underlying mechanisms of its activity remain to be elucidated. The present study investigated the effects of D. obtusifolius methanolic extract (DOME) on lipopolysaccharide (LPS)‑stimulated inflammation in RAW264.7 cells. The effects of DOME on the production of nitric oxide, prostaglandin E2 and pro‑inflammatory cytokines were assessed by ELISA, western blot analysis and reverse transcription‑quantitative polymerase chain reaction. It was demonstrated that expression of inducible nitric oxide synthase, cyclooxygenase‑2, interleukin‑1β and tumor necrosis factor‑α was suppressed by DOME in LPS‑stimulated cells. Furthermore, treatment with DOME suppressed phosphorylation of mitogen activated protein kinase (MAPK) molecules, including extracellular signal‑regulated kinase, c‑Jun N‑terminal kinase and p38 MAPK. Translocation of the nuclear factor‑κB p65 subunit into the nucleus was additionally inhibited by DOME. Phosphorylation of MAPK promoter activity was inhibited by treatment with DOME, PD98059, SB202190 and SP600125. These results demonstrated that DOME inhibits LPS‑induced inflammatory responses. Therefore, DOME may be a potential therapeutic approach for the treatment of inflammatory diseases.

Immunobiology of Nitric Oxide and Regulation of Inducible Nitric Oxide Synthase

Nitric oxide (NO) is a bioactive gas that has multiple roles in innate and adaptive immune responses. In macrophages, nitric oxide is produced by inducible nitric oxide synthase upon microbial and cytokine stimulation. It is needed for host defense against pathogens and for immune regulation. This review will summarize the role of NO and iNOS in inflammatory and immune responses and will discuss the regulatory mechanisms that control inducible nitric oxide synthase expression and activity.

TLN-58, an Additional hCAP18 Processing Form, Found in the Lesion Vesicle of Palmoplantar Pustulosis in the Skin

We previously reported that the early vesicle of the palmoplantar pustulosis (PPP) vesicle originated from eccrine sweat in the acrosyringium and that the PPP vesicle contains the antimicrobial peptide human cathelicidin-18/LL-37. The concentration of LL-37 was sufficient to induce the subsequent inflammation in lesions and human keratinocytes, and the PPP vesicles contained additional small fragments of human cathelicidin-18, of approximately 7 kDa, which have not been identified. The aim of the present study was to clarify the additional processed forms found in PPP vesicles and their physiological effects on normal keratinocytes and sweat gland cells. Lesional PPP vesicles were collected from PPP patients, and endogenous human cathelicidin-18/LL-37 was depleted using a LL-37 antibody affinity column. A designed recombinant human cathelicidin-18 peptide was prepared and incubated with the depleted PPP vesicle fluid to confirm the additional processed form. In-gel digestion analysis and protein sequencing confirmed the additional form as TLN-58. TLN-58 up-regulated IL-17C, IL-8, IL-23, IL-1α, and IL-1β mRNA and protein expression in normal human keratinocytes and also showed antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, and group A Streptococcus species, similar to LL-37. This additional form could be involved in the continued inflammation in PPP lesions.

PDK1 in NF-κB signaling is a target of Xanthium strumarium methanolic extract-mediated anti-inflammatory activities

ETHNOPHARMACOLOGICAL RELEVANCE

Xanthium strumarium L. (Asteraceae) has traditionally been used to treat bacterial infections, nasal sinusitis, urticaria, arthritis, chronic bronchitis and rhinitis, allergic rhinitis, edema, lumbago, and other ailments. However, the molecular mechanisms by which this plant exerts its anti-inflammatory effects are poorly characterized. Here we studied the immunopharmacological activities of the methanolic extract of the aerial parts of this plant (Xs-ME) and validated its pharmacological targets.

MATERIALS AND METHODS

To evaluate the anti-inflammatory activity of Xs-ME, we employed lipopolysaccharide (LPS)-treated macrophages and an HCl/EtOH-induced mouse model of gastritis. We also used HPLC to identify the potentially active anti-inflammatory components of this extract. The molecular mechanisms of its anti-inflammatory activity were studied by kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes.

RESULTS

The production of nitric oxide (NO) and prostaglandin E2 (PGE2) were both suppressed by Xs-ME. Moreover, orally administered Xs-ME ameliorated HCl/EtOH-induced gastric lesions. Furthermore, this extract downregulated the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 and reduced the nuclear levels of NF-κB. Signaling events upstream of NF-κB translocation, such as phosphorylation of AKT and the formation of PDK1-AKT signaling complexes, were also inhibited by Xs-ME. Moreover, Xs-ME suppressed the enzymatic activity of PDK1. Additionally, PDK1-induced luciferase activity and Akt phosphorylation were both inhibited by Xs-ME. We also identified the polyphenol resveratrol as a likely active anti-inflammatory component in Xs-ME that targets PDK1.

CONCLUSION

Xs-ME exerts anti-inflammatory activity in vitro and in vivo by inhibiting PDK1 kinase activity and blocking signaling to its downstream transcription factor, NF-κB.

Biochemical and Biophysical Cues in Matrix Design for Chronic and Diabetic Wound Treatment

Progress in biomaterial science and engineering and increasing knowledge in cell biology have enabled us to develop functional biomaterials providing appropriate biochemical and biophysical cues for tissue regeneration applications. Tissue regeneration is particularly important to treat chronic wounds of people with diabetes. Understanding and controlling the cellular microenvironment of the wound tissue are important to improve the wound healing process. In this study, we review different biochemical (e.g., growth factors, peptides, DNA, and RNA) and biophysical (e.g., topographical guidance, pressure, electrical stimulation, and pulsed electromagnetic field) cues providing a functional and instructive acellular matrix to heal diabetic chronic wounds. The biochemical and biophysical signals generally regulate cell-matrix interactions and cell behavior and function inducing the tissue regeneration for chronic wounds. Some technologies and devices have already been developed and used in the clinic employing biochemical and biophysical cues for wound healing applications. These technologies can be integrated with smart biomaterials to deliver therapeutic agents to the wound tissue in a precise and controllable manner. This review provides useful guidance in understanding molecular mechanisms and signals in the healing of diabetic chronic wounds and in designing instructive biomaterials to treat them.

MCPIP-1, Alias Regnase-1, Controls Epithelial Inflammation by Posttranscriptional Regulation of IL-8 Production

Pattern recognition receptors are critical for the detection of invading microorganisms. They activate multiple pathways that lead to the induction of proinflammatory responses and pathogen clearance. The intensity and duration of this immune reaction must be tightly controlled spatially and temporally in every tissue by different negative regulators. We hypothesized that monocyte chemoattractant protein-1-induced protein-1 (MCPIP-1) might play a role in maintaining immune homeostasis in the epithelium both under physiological conditions and upon bacterial infection. To this end, we examined the distribution of the MCPIP-1 transcript and protein in various tissues. The MCPIP-1 protein level was higher in epithelial cells than in myeloid cells. MCPIP-1 exerted RNase activity towards the interleukin (IL)-8 transcript and the lifespan of IL-8 was determined by the presence of the stem-loops/hairpin structures at the 3'UTR region of IL-8 mRNA. Moreover, using fully active, purified recombinant MCPIP-1 protein, we elucidated the mechanism by which MCPIP-1 controls the IL-8 mRNA level. In conclusion, we uncovered a novel IL-8-dependent mechanism via which MCPIP-1 maintains epithelial homeostasis. This study reveals for the first time that MCPIP-1 plays a crucial anti-inflammatory role not only in myeloid cells but also in epithelial cells.

A Novel Treatment of Contact Dermatitis by Topical Application of Phospholipase A2 Inhibitor: A Double-Blind Placebo-Controlled Pilot Study

Phospholipase A2 hydrolyzes membrane phospholipids releasing arachidonic acid and lysophospholipids. These are key precursors of inflammatory mediators, such as prostaglandins, leukotrienes, thromboxanes and PAF, in numerous inflammatory/allergic diseases, including skin inflammation. Accordingly, inhibition of PLA2 has long been postulated as a potentially potent antiinflammatory therapy. In the present study we tested the effect of a novel PLA2 inhibitor on contact dermatitis in human subjects. A double-blind, placebo-controlled pilot study was conducted on contact dermatitis patients (n = 11) treated with the inhibitor-containing topical preparation (1% cream). Disease severity was assessed by physician's assessment before treatment (day 0) as well as after 14-days and 30-days. Patients treated with 1% PLA2 inhibitor-containing cream showed a 69.9% reduction in disease score while placebo-treated patients showed a reduction of 36.5% with p = 0.0024. The clear improvement in the disease score of inhibitor-treated patients supports the involvement of PLA2 activity in skin inflammation and the therapeutic prospective of its inhibition.

In vitro antioxidative and anti-inflammatory effects of the compound K-rich fraction BIOGF1K, prepared from Panax ginseng

Background

BIOGF1K, a compound K-rich fraction prepared from the root of Panax ginseng, is widely used for cosmetic purposes in Korea. We investigated the functional mechanisms of the anti-inflammatory and antioxidative activities of BIOGF1K by discovering target enzymes through various molecular studies.

Methods

We explored the inhibitory mechanisms of BIOGF1K using lipopolysaccharide-mediated inflammatory responses, reporter gene assays involving overexpression of toll-like receptor adaptor molecules, and immunoblotting analysis. We used the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay to measure the antioxidative activity. We cotransfected adaptor molecules, including the myeloid differentiation primary response gene 88 (MyD88) and Toll/interleukin-receptor domain containing adaptor molecule-inducing interferon-β (TRIF), to measure the activation of nuclear factor (NF)-κB and interferon regulatory factor 3 (IRF3).

Results

BIOGF1K suppressed lipopolysaccharide-triggered NO release in macrophages as well as DPPH-induced electron-donating activity. It also blocked lipopolysaccharide-induced mRNA levels of interferon-β and inducible nitric oxide synthase. Moreover, BIOGF1K diminished the translocation and activation of IRF3 and NF-κB (p50 and p65). This extract inhibited the upregulation of NF-κB-linked luciferase activity provoked by phorbal-12-myristate-13 acetate as well as MyD88, TRIF, and inhibitor of κB (IκBα) kinase (IKKβ), and IRF3-mediated luciferase activity induced by TRIF and TANK-binding kinase 1 (TBK1). Finally, BIOGF1K downregulated the NF-κB pathway by blocking IKKβ and the IRF3 pathway by inhibiting TBK1, according to reporter gene assays, immunoblotting analysis, and an AKT/IKKβ/TBK1 overexpression strategy.

Conclusion

Overall, our data suggest that the suppression of IKKβ and TBK1, which mediate transcriptional regulation of NF-κB and IRF3, respectively, may contribute to the broad-spectrum inhibitory activity of BIOGF1K.

In vitro and in vivo anti-inflammatory activity of Phyllanthus acidus methanolic extract

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus acidus (L.) Skeels (Phyllanthaceae) has traditionally been used to treat gastric trouble, rheumatism, bronchitis, asthma, respiratory disorders, and hepatitis. Despite this widespread use, the pharmacological activities of this plant and their molecular mechanisms are poorly understood. Therefore, we evaluated the immunopharmacological activities of the methanolic extract of the aerial parts of this plant (Pa-ME) and validated its pharmacological targets.

MATERIALS AND METHODS

Lipopolysaccharide (LPS)-treated macrophages, an HCl/EtOH-induced gastritis model, and an acetic acid-injected capillary permeability mouse model were employed to evaluate the anti-inflammatory activity of Pa-ME. Potentially active anti-inflammatory components of this extract were identified by HPLC. The molecular mechanisms of the anti-inflammatory activity were studied by kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes.

RESULTS

Pa-ME suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) and prevented morphological changes in LPS-treated RAW264.7 cells. Moreover, both HCl/EtOH-induced gastric damage and acetic acid-triggered vascular permeability were restored by orally administered Pa-ME. Furthermore, this extract downregulated the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 and reduced the nuclear levels of NF-κB. Signalling events upstream of NF-κB translocation, such as phosphorylation of Src and Syk and formation of Src/Syk signalling complexes, were also inhibited by Pa-ME. The enzymatic activities of Src and Syk were also suppressed by Pa-ME. Moreover, Src-induced and Syk-induced luciferase activity and p85/Akt phosphorylation were also inhibited by Pa-ME. Of the identified flavonoids, kaempferol and quercetin were revealed as partially active anti-inflammatory components in Pa-ME.

CONCLUSION

Pa-ME exerts anti-inflammatory activity in vitro and in vivo by suppressing Src, Syk, and their downstream transcription factor, NF-κB.

Silicon-based quantum dots induce inflammation in human lung cells and disrupt extracellular matrix homeostasis

Quantum dots (QDs) are nanocrystalline semiconductor materials that have been tested for biological applications such as cancer therapy, cellular imaging and drug delivery, despite the serious lack of information of their effects on mammalian cells. The present study aimed to evaluate the potential of Si/SiO2 QDs to induce an inflammatory response in MRC-5 human lung fibroblasts. Cells were exposed to different concentrations of Si/SiO2 QDs (25-200 μg·mL(-1)) for 24, 48, 72 and 96 h. The results obtained showed that uptake of QDs was dependent on biocorona formation and the stability of nanoparticles in various biological media (minimum essential medium without or with 10% fetal bovine serum). The cell membrane damage indicated by the increase in lactate dehydrogenase release after exposure to QDs was dose- and time-dependent. The level of lysosomes increased proportionally with the concentration of QDs, whereas an accumulation of autophagosomes was also observed. Cellular morphology was affected, as shown by the disruption of actin filaments. The enhanced release of nitric oxide and the increase in interleukin-6 and interleukin-8 protein expression suggested that nanoparticles triggered an inflammatory response in MRC-5 cells. QDs decreased the protein expression and enzymatic activity of matrix metalloproteinase (MMP)-2 and MMP-9 and also MMP-1 caseinase activity, whereas the protein levels of MMP-1 and tissue inhibitor of metalloproteinase-1 increased. The present study reveals for the first time that silicon-based QDs are able to generate inflammation in lung cells and cause an imbalance in extracellular matrix turnover through a differential regulation of MMPs and tissue inhibitor of metalloproteinase-1 protein expression.

In vivo and in vitro anti-inflammatory activities of Persicaria chinensis methanolic extract targeting Src/Syk/NF-κB

ETHNOPHARMACOLOGIC RELEVANCE

Persicaria chinensis L. (Polygonaceae) [also synonym as Polygonum chimnense L.] has been used as Chinese traditional medicine to treat ulcer, eczema, stomach ache, and various inflammatory skin diseases. Due to no molecular pharmacological evidence of this anti-inflammatory herbal plant, we investigated the inhibitory mechanisms and target proteins contributing to the anti-inflammatory responses of the plant by using its methanolic extract (Pc-ME).

MATERIALS AND METHODS

We used lipopolysaccharide (LPS)-treated macrophages and a murine HCl/EtOH-induced gastritis model to evaluate the anti-inflammatory activity of Pc-ME. HPLC analysis was employed to identify potential active components of this extract. Molecular approaches including kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes were used to confirm target enzymes.

RESULTS

Pc-ME inhibited LPS-induced nitric oxide and prostaglandin E2 release by RAW264.7 macrophages and ameliorated HCl/EtOH-induced gastric ulcers in mice. The nuclear translocation of NF-κB (p65 and p50) was suppressed by Pc-ME. Phosphorylation of Src and Syk, their kinase activities, and formation of the signaling complex of these proteins were repressed by Pc-ME. Phosphorylation of p85 and Akt induced by Src or Syk overexpression was blocked by Pc-ME. In the mouse gastritis model, orally administered Pc-ME suppressed the increased phosphorylation of IκBα, Αkt, Src, and Syk. Caffeic acid, kaempferol, and quercetin, identified as major anti-inflammatory components of Pc-ME by HPLC, displayed strong nitric oxide inhibitory activity in LPS-treated macrophages.

CONCLUSION

Pc-ME might play a pivotal ethnopharmacologic role as an anti-inflammatory herbal medicine by targeting Syk and Src kinases and their downstream transcription factor NF-κB.

Biologics in dermatology: an integrated review

The advent of biologics in dermatologic treatment armentarium has added refreshing dimensions, for it is a major breakthrough. Several agents are now available for use. It is therefore imperative to succinctly comprehend their pharmacokinetics for their apt use. A concerted endeavor has been made to delve on this subject. The major groups of biologics have been covered and include: Drugs acting against TNF-α, Alefacept, Ustekinumab, Rituximab, IVIG and Omalizumab. The relevant pharmacokinetic characteristics have been detailed. Their respective label (approved) and off-label (unapproved) indications have been defined, highlighting their dosage protocol, availability and mode of administration. The evidence level of each indication has also been discussed to apprise the clinician of their current and prospective uses. Individual anti-TNF drugs are not identical in their actions and often one is superior to the other in a particular disease. Hence, the section on anti-TNF agents mentions the literature on each drug separately, and not as a group. The limitations for their use have also been clearly brought out.

Picea mariana polyphenolic extract inhibits phlogogenic mediators produced by TNF-α-activated psoriatic keratinocytes: Impact on NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Picea mariana ((Miller) Britton, Sterns, and Poggenburg; Pinaceae) bark has been traditionally used by North American natives for treating topical inflammations. It has been also suggested to improve various inflammatory skin disorders like Psoriasis vulgaris. Extracts from this bark storage protein contain polyphenolic compounds which have well-known antiinflammatory activities. Based on the capacity of polyphenolic compounds to modulate functions of normal human keratinocytes, this study was set up to decipher the mechanisms of action of a chemically characterized polyphenolic extract from Picea mariana bark (BS-EAcf) on lesional keratinocytes of skin with psoriasis vulgaris, a disease driven by the immune system in which TNF-α plays a significant role.

MATERIALS AND METHODS

BS-EAcf corresponds to the ethyl acetate soluble fraction from the hot water extract of Picea mariana bark. BS-EAcf effects were evaluated in normal human (NHK) and psoriatic (PK) keratinocytes stimulated by TNF-α. Cell viability was assessed by lactate deshydrogenase release and propidium iodide (PI) staining. The mechanisms of action of BS-EAcf in keratinocytes were investigated by flow cytometry, ELISAs, RT-PCR and western blot analyses.

RESULTS

PK exhibited a higher response to TNF-α than NHK regarding the ICAM-1 expression and the production of NO, IL-6, IL-8, fractalkine and PGE2, whereas BS-EAcf significantly inhibited this TNF-α-induced increase at concentrations without causing keratinocyte toxicity. Additionally, this extract significantly inhibited the TNF-α-induced release of elafin and VEGF by PK and NHK. Since TNF-α activation of most of these factors is dependent on the NF-κB pathway, this latter was studied in TNF-α-activated PK. BS-EAcf inhibited the TNF-α-induced phosphorylation and degradation of total IκBα as well as phosphorylation of NF-κB p65.

CONCLUSIONS

The ethyl acetate fraction from Picea mariana bark extract showed inhibitory effects of cytokines, chemokines, adhesion molecules, nitric oxide and prostaglandins produced by keratinocytes under TNF-α activation through down-regulating the NF-κB pathway. This study demontrated that this extract could be a potential antiinflammatory agent capable of improving psoriatic skin.

In vitro anti-inflammatory effect of picrasmalignan A by the inhibition of iNOS and COX‑2 expression in LPS‑activated macrophage RAW 264.7 cells

Picrasma quassioides (P. quassioides) has been widely used as a traditional Chinese medicine for clearing fever and detoxification. Previous phytochemical studies have identified a novel dihydrobenzofuran-type neolignan, picrasmalignan A, isolated from the stems of P. quassioides. In the present study, the in vitro anti-inflammatory effects and molecular mechanisms of picrasmalignan A have been investigated in cultured RAW 264.7 cells, a mouse macrophage‑like cell line. A Griess assay was used to demonstrate the inhibitory effect of picrasmalignan A on the overproduction of nitric oxide (NO). An enzyme-linked immunosorbent assay was used to determine the levels of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The inhibitory effect on the enzymatic activity of cyclooxygenase 2 (COX‑2) and inducible nitric oxide synthase (iNOS) was observed by colorimetric and fluorimetric assays, respectively. Western blotting was conducted to detect the expression of iNOS and COX-2. Results showed that picrasmalignan A suppressed lipopolysaccharide-stimulated NO production and pro-inflammatory cytokine secretion, including TNF-α and IL-6, in a dose-dependent manner. It also significantly inhibited the expression and enzymatic activity of iNOS and COX-2. These results may demonstrate the anti-inflammatory mechanism of picrasmalignan A.

Neural nitric oxide synthase participates in pemphigus vulgaris acantholysis through upregulation of Rous sarcoma, mammalian target of rapamycin and focal adhesion kinase

Pemphigus vulgaris (PV) is an autoimmune blistering skin disease characterized by suprabasal acantholysis produced as a consequence of desmoglein (Dsg) and non-Dsg autoantibodies binding to several targeting molecules localized on the membrane of keratinocytes. Nitric oxide (NO) may exert a pathogenic function in several immunological processes. We have previously demonstrated that neural nitric oxide synthase (nNOS) plays part in PV acantholysis. Also, our group has described a relevant role for HER [human epidermal growth factor receptor (EGFR) related] isoforms and several kinases such as Src (Rous sarcoma), mammalian target of rapamycin (mTOR) and focal adhesion kinase (FAK), as well as caspases in PV development. Using a passive transfer mouse model of PV, we aimed to investigate the relationship between the increase in nNOS and EGFR, Src, mTOR and FAK kinase upregulation observed in PV lesions. Our results revealed a new function for nNOS, which contributes to EGFR-mediated PV acantholysis through the upregulation of Src, mTOR and FAK. In addition, we found that nNOS participates actively in PV at least in part by increasing caspase-9 and caspase-3 activities. These findings underline the important issue that in PV acantholysis, caspase activation is a nNOS-linked process downstream of Src, mTOR and FAK kinase upregulation.

CD8(+) T cells mediate RAS-induced psoriasis-like skin inflammation through IFN-γ

The RAS signaling pathway is constitutively activated in psoriatic keratinocytes. We expressed activated H-RAS^V12G in suprabasal keratinocytes of adult mice and observed rapid development of a psoriasis-like skin phenotype characterized by basal keratinocyte hyperproliferation, acanthosis, hyperkeratosis, intraepidermal neutrophil microabscesses and increased Th1/Th17 and Tc1/Tc17 skin infiltration. The majority of skin infiltrating CD8⁺ T cells co-expressed IFN-γ and IL-17A. When RAS was expressed on a Rag1−/− background, microabscess formation, iNOS expression and keratinocyte hyperproliferation were suppressed. Depletion of CD8⁺ but not CD4⁺ T cells reduced cutaneous and systemic inflammation, the RAS-induced increase in cutaneous Th17 and IL-17⁺ γΔ T cells, and epidermal hyperproliferation to levels similar to a Rag1−/− background. Reconstitution of Rag1−/− inducible RAS mice with purified CD8⁺ T cells restored microabscess formation and epidermal hyperproliferation. Neutralization of IFN-γ but not IL-17A in CD8⁺ T cell reconstituted Rag1−/− mice expressing RAS blocked CD8-mediated skin inflammation, iNOS expression and keratinocyte hyperproliferation. These results show for that CD8⁺ T cells can orchestrate skin inflammation with psoriasis-like pathology in response to constitutive RAS activation in keratinocytes, and this is primarily mediated through IFN-γ.

Sphingosine 1-phosphate protects primary human keratinocytes from apoptosis via nitric oxide formation through the receptor subtype S1P₃

Although the lipid mediator sphingosine 1-phosphate (S1P) has been identified to induce cell growth arrest of human keratinocytes, the sphingolipid effectively protects these epidermal cells from apoptosis. The molecular mechanism of the anti-apoptotic action induced by S1P is less characterized. Apart from S1P, endogenously produced nitric oxide (NO•) has been recognized as a potent modulator of apoptosis in keratinocytes. Therefore, it was of great interest to elucidate whether S1P protects human keratinocytes via a NO•-dependent signalling pathway. Indeed, S1P induced an activation of endothelial nitric oxide synthase (eNOS) in human keratinocytes leading to an enhanced formation of NO•. Most interestingly, the cell protective effect of S1P was almost completely abolished in the presence of the eNOS inhibitor L-NAME as well as in eNOS-deficient keratinocytes indicating that the sphingolipid metabolite S1P protects human keratinocytes from apoptosis via eNOS activation and subsequent production of protective amounts of NO•. It is well established that most of the known actions of S1P are mediated by a family of five specific G protein-coupled receptors. Therefore, the involvement of S1P-receptor subtypes in S1P-mediated eNOS activation has been examined. Indeed, this study clearly shows that the S1P(3) is the exclusive receptor subtype in human keratinocytes which mediates eNOS activation and NO• formation in response to S1P. In congruence, when the S1P(3) receptor subtype is abrogated, S1P almost completely lost its ability to protect human keratinocytes from apoptosis.

IL-17A synergizes with IFN-γ to upregulate iNOS and NO production and inhibit chlamydial growth

IFN-γ-mediated inducible nitric oxide synthase (iNOS) expression is critical for controlling chlamydial infection through microbicidal nitric oxide (NO) production. Interleukin-17A (IL-17A), as a new proinflammatory cytokine, has been shown to play a protective role in host defense against Chlamydia muridarum (Cm) infection. To define the related mechanism, we investigated, in the present study, the effect of IL-17A on IFN-γ induced iNOS expression and NO production during Cm infection in vitro and in vivo. Our data showed that IL-17A significantly enhanced IFN-γ-induced iNOS expression and NO production and inhibited Cm growth in Cm-infected murine lung epithelial (TC-1) cells. The synergistic effect of IL-17A and IFN-γ on Chlamydia clearance from TC-1 cells correlated with iNOS induction. Since one of the main antimicrobial mechanisms of activated macrophages is the release of NO, we also examined the inhibitory effect of IL-17A and IFN-γ on Cm growth in peritoneal macrophages. IL-17A (10 ng/ml) synergizes with IFN-γ (200 U/ml) in macrophages to inhibit Cm growth. This effect was largely reversed by aminoguanidine (AG), an iNOS inhibitor. Finally, neutralization of IL-17A in Cm infected mice resulted in reduced iNOS expression in the lung and higher Cm growth. Taken together, the results indicate that IL-17A and IFN-γ play a synergistic role in inhibiting chlamydial lung infection, at least partially through enhancing iNOS expression and NO production in epithelial cells and macrophages.

Antioxidant and anti-inflammatory activities of Maillard reaction products isolated from sugar-amino acid model systems

We investigated the antioxidant and anti-inflammatory activities of both crude and ultrafiltrated Maillard reaction (MR) products (MRPs) derived from sugar-amino acid MR models, comprising fructose (Fru), glucose (Glu) or ribose (Rib) reacted with glycine (Gly) or lysine (Lys), respectively. Crude MRPs derived from Glu-Lys showed the greatest capacity (P < 0.05) to inhibit nitric oxide (NO) and interleukin 8 (IL-8) production in interferon γ and phorbol ester-induced Caco-2 cells. Moreover, one ultrafiltrated fraction (MW < 1 kDa) recovered from Glu-Lys exhibited the greatest (P < 0.05) affinity to inhibit NO. This effect also corresponded to an inhibition of both iNOS transcription and translation. The NO and IL-8 inhibitory activities of crude MRPs were positively correlated with intracellular oxidation inhibitory activity. In conclusion, we have demonstrated an anti-inflammatory capacity of MRPs in inflamed Caco-2 cells that is specific to low molecular weight (MW < 1 kDa) Glu-Lys MRPs.

Glutathione peroxidase activity in the blood cells of psoriatic patients correlates with their responsiveness to Efalizumab

Biological treatment of psoriasis, a chronic inflammatory immune-mediated pathology of huge social impact, has become a recent revolutionizing breakthrough in the management of the disease. Apart from anti-TNF-alpha biologics, recombinant proteins-inhibitors of the T lymphocytes-antigen presenting cells interaction, Efalizumab among them, have been successfully used in the therapy of psoriasis. Serious concern regarding safety and efficacy of biologics remains because they induce numerous adverse effects and a significant number of patients are non-responders. Up-to-now, there are no biochemical or/and immunological markers of the clinical efficacy of these drugs. This study searches for immunological and redox markers of the clinical response in the group of psoriatic patients treated with Efalizumab. Clinical response to Efalizumab was assessed by Psoriasis Area and Severity Index and correlated with suppression of T-cell functions, plasma cytokines, membrane-associated polyunsaturated fatty acids (PUFAs), antioxidant enzymes and markers of oxidative stress. A 12-week Efalizumab therapy did not affect abnormal plasma levels of pro-inflammatory cytokines and lower-than-normal content of PUFAs esterified in phospholipids of red cell membranes. It did, however, suppress T-cell-mediated functions and decrease nitrites/nitrates and malonyl dialdehyde levels independently on the clinical outcome. On contrast, activities of glutathione peroxidase (GPx) and glutathione S-transferase in granulocytes were remarkably increased and catalase decreased exclusively in non-responders vs complete or partial responders. High baseline GPx in erythrocytes decreased in responders. It is concluded that clinical response to Efalizumab correlates with GPx activity in the blood cells, suggesting that high hydroperoxide levels are involved in psoriasis persistence.

Redox imbalance in T cell-mediated skin diseases

The skin is permanently exposed to physical, chemical, and biological aggression by the environment. In addition, acute and chronic inflammatory events taking place in the skin are accompanied by abnormal release of pro-oxidative mediators. In this paper, we will briefly overview the homeostatic systems active in the skin to maintain the redox balance and also to counteract abnormal oxidative stress. We will concentrate on the evidence that a local and/or systemic redox dysregulation accompanies the chronic inflammatory disorder events associated to psoriasis, contact dermatitis, and atopic dermatitis. We will also discuss the fact that several well-established treatments for the therapy of chronic inflammatory skin disorders are based on the application of strong physical or chemical oxidants onto the skin, indicating that, in selected conditions, a further increase of the oxidative imbalance may lead to a beneficial outcome.

Inhibition of IL-8 production by green tea polyphenols in human nasal fibroblasts and A549 epithelial cells

The attraction of leukocytes to tissues is essential in order for inflammation and the host response to infection to occur. Airway inflammation is a very common cause illness with a substantial impact on health care. Neutrophils play an essential role in the host defense and in inflammation, but the latter may trigger and sustain the pathogenesis of a range of acute and chronic diseases. Infiltration of neutrophils occurs as a response to chemoattractant molecules by resident tissue cells. The recruitment of neutrophils in airway inflammation may account for the generation of IL-8. To evaluate the effectiveness of green tea polyphenols in the modulation of airway inflammation through the blocking of neutrophil chemokine production, nasal mucosal fibroblasts and A549 bronchial epithelial cells were analyzed for the production of IL-8. Both nasal mucosal fibroblasts and bronchial epithelial cells produced significant amounts of IL-8 through stimulation of IL-1beta. Tea polyphenols were very effective in the inhibition of IL-8 production. Among the polyphenols tested, EGCG and ECG showed strong inhibitory activity in dose-dependent manners. EGC and EC showed moderate inhibition at 48 h culture, whereas (-)catechin was not effective. Production of IL-8 after stimulation by proinflammatory cytokines in both nasal fibroblasts and bronchial epithelial cells was significantly blocked by pretreatment with green tea polyphenols.

Anti-inflammatory effect of Streblus asper leaf extract in rats and its modulation on inflammation-associated genes expression in RAW 264.7 macrophage cells

AIM OF THIS STUDY

Streblus asper is a medicinal plant from Thailand used in folk medicine for the treatment of several inflammatory diseases. In this study, we investigated the anti-inflammatory effect of Streblus asper leaf ethanolic extract (SAE).

MATERIALS AND METHODS

The experimental carrageenan-induced paw edema in rats was performed in which the SAE at doses of 125, 250, 500 mg/kg body weight was intraperitoneally administered to the rats. Then, reverse transcriptive polymerase chain reaction (RT-PCR) technique was also performed to determine the effect of SAE on the expression of inflammation-associated genes in RAW 264.7 macrophage cells stimulated with lipopolysaccharide (LPS).

RESULTS

The SAE at all given doses caused a significant dose-dependent inhibition of edema (p<0.05). Moreover, the significant and dose-dependent LPS-induced cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) mRNA expressions were demonstrated in RAW 264.7 cells treated with SAE. The inhibition is selective, since COX-1 mRNA expression did not change in the presence of SAE.

CONCLUSION

The results of this study are the first scientific evidence on the molecular effects of Streblus asper as a potential anti-inflammatory agent, which supports the fact that the plant is employed in traditional remedies.

Emerging treatments in the management of psoriasis: biological targeting with ustekinumab

Psoriasis is a chronic, genetically determined, immune-mediated, inflammatory skin disease affecting approximately 2% to 3% of Caucasian population. Given the well-established role of the immuno-mediated inflammation in the pathogenesis of psoriasis, in the past few years several key steps in the pathogenesis of this disease have been elucidated and the increased knowledge led to the development of specific drugs, commonly defined as “biologics” targeting one or more of these steps. At present an anti-CD11a antibody (efalizumab), an anti-LFA3/CD2 receptor (alefacept) and 3 antitumor necrosis factor alpha agents (adalimumab, etanercept, infliximab) are now commercially available for the treatment of both psoriasis and psoriatic arthritis. Recent studies have demonstrated that interleukins (IL) 12 and 23 play an important role in the pathophysiology of psoriasis. In fact members of the IL-12 family of cytokines have the potential to act as the next major cytokine(s) in pathogenesis and the treatment of psoriasis. Ustekinumab (CNTO 1275, Centocor Inc, Malvern, PA, USA) is a human monoclonal antibody that binds to the shared p40 protein subunit of human interleukins 12 and 23 with high affinity and specificity, thereby preventing interaction with their surface IL-12Rβ1 receptor. Different clinical studies have been conducted to date. In particular a phase II study and two phase III studies, PHOENIX 1 together with PHOENIX 2, show very encouraging results. This review reports on the latest progress made in the clinical use of biologic drugs for psoriasis focusing on the new human IL-12/23 monoclonal antibody, ustekinumab, for psoriasis.

In vitro anti-inflammatory effects of arctigenin, a lignan from Arctium lappa L., through inhibition on iNOS pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Arctigenin, a bioactive constituent from dried seeds of Arctium lappa L. (Compositae) which has been widely used as a Traditional Chinese Medicine for dispelling wind and heat included in Chinese Pharmacophere, was found to exhibit anti-inflammatory activities but its molecular mechanism remains unknown yet.

AIM OF THE STUDY

To investigate the anti-inflammatory mechanism of arctigenin.

MATERIALS AND METHODS

Cultured macrophage RAW 264.7 cells and THP-1 cells were used for the experiments. Griess assay was used to evaluate the inhibitory effect of arctigenin on the overproduction of nitric oxide (NO). ELISA was used to determine the level of pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6). The inhibitory effect on the enzymatic activity of cyclooxygenase-2 (COX-2) was tested by colorimetric method. Western blot was used to detect the expression of inducible nitric oxide synthase (iNOS) and COX-2.

RESULTS

Arctigenin suppressed lipopolysaccharide (LPS)-stimulated NO production and pro-inflammatory cytokines secretion, including TNF-alpha and IL-6 in a dose-dependent manner. Arctigenin also strongly inhibited the expression of iNOS and iNOS enzymatic activity, whereas the expression of COX-2 and COX-2 enzymatic activity were not affected by arctigenin.

CONCLUSIONS

These results indicated that potent inhibition on NO, TNF-alpha and IL-6, but not COX-2 expression and COX-2 activity, might constitute the anti-inflammatory mechanism of arctigenin. Arctigenin suppressed the overproduction of NO through down-regulation of iNOS expression and iNOS enzymatic activity in LPS-stimulated macrophage.

Clinical and biochemical effects of coenzyme Q(10), vitamin E, and selenium supplementation to psoriasis patients

OBJECTIVE

The aim of the present study was to evaluate clinical effects of supplementation with antioxidants to patients with severe erythrodermic (EP) and arthropathic (PsA) forms of psoriasis.

METHODS

Fifty-eight patients were hospitalized, treated by conventional protocols, and randomly assigned to four groups. Groups EP1 and PsA1 were supplemented with coenzyme Q(10) (ubiquinone acetate, 50 mg/d), vitamin E (natural alpha-tocopherol, 50 mg/d), and selenium (aspartate salt, 48 mug/d) dissolved in soy lecithin for 30-35 d. Groups EP2 and PsA2 (placebo) received soy lecithin. Clinical conditions were assessed by severity parameters. Markers of oxidative stress included superoxide production, copper/zinc-superoxide dismutase, and catalase activities in the circulating granulocytes, in the affected epidermis, and plasma levels of nitrites/nitrates.

RESULTS

At baseline patients had an increased superoxide release from granulocytes (10.0 +/- 0.5, 2.9 +/- 0.2, and 1.5 +/- 0.1 nmol/L per 10(6) cells/h for EP, PsA, and donors, respectively), increased copper/zinc-superoxide dismutase and catalase activities in granulocytes in EP patients and decreased in PsA patients, decreased activity of copper/zinc-superoxide dismutase (0.3 +/- 0.0, 1.8 +/- 0.1, and 2.2 +/- 0.2 U/mg protein for EP, PsA, and donors, respectively), and altered activity of catalase in psoriatic epidermis. Plasma levels of nitrites/nitrates were greater than normal in psoriatic patients. Supplementation resulted in significant improvement of clinical conditions, which corresponded to the faster versus placebo normalization of the oxidative stress markers.

CONCLUSION

Supplementation with antioxidants coenzyme Q(10), vitamin E, and selenium could be feasible for the management of patients with severe forms of psoriasis.

Acute stress induces proinflammatory signaling at chronic inflammation sites

OBJECTIVES

To analyze in a randomized controlled study whether acute psychological stress alters local proinflammatory signals in a human model of chronic inflammation, i.e., gingivitis. Chronic inflammation represents a crucial factor in a variety of diseases and factors that contribute to the onset and progression of disease. Psychological stress is assumed to represent such a factor. However, experimental human research in this area is rare.

METHODS

A total of 25 students (n = 11 females, 14 males) suffering from gingivitis were subjected to a stress (public-speaking task) and to a control condition in randomized order. Local concentrations of interleukin (IL)-8 were quantified as an indicator of proinflammatory activity at sites of inflammation. IL-8 is a strong proinflammatory mediator and involved in a variety of disease processes. Samples were taken at sites of inflammation before stress versus control condition and 0, 45, and 90 minutes afterward.

RESULTS

A significant main effect (p = .03) of acute stress on local IL-8 was found. Stress induced an increase of IL-8-concentrations; univariate effect sizes varied between d = 0.23 and d = 0.36.

CONCLUSION

This is the first human experimental in vivo study demonstrating that psychological stress alters the local concentrations of IL-8 under conditions of chronic inflammation. It provides direct evidence acute stress is involved in the regulation of local proinflammatory responses in chronic inflammation. Future studies should now explore the effects of more enduring stress conditions and the factors mediating stress effects on inflammatory signals.