Enhanced release of inflammatory mediators from lithium-stimulated neutrophils in psoriasis

Anti-psoriasis effect of 18β-glycyrrhetinic acid by breaking CCL20/CCR6 axis through its vital active group targeting GUSB/ATF2 signaling

BACKGROUND

Psoriasis is an immune-mediated chronic inflammatory skin disease. Current research suggests that the long-term persistence and recurrence of psoriasis are closely related to the feedback loop formed between keratinocytes and immune cells, especially in Th 17 or DC cells expressing CCR6. CCL20 is the ligand of CCR6. Therefore, drugs that block the expression of CCL20 or CCR6 may have a certain therapeutic effect on psoriasis. Glycyrrhetinic acid (GA) is the main active ingredient of the plant drug licorice and is often used to treat autoimmune diseases, including psoriasis. However, its mechanism of action is still unclear.

METHODS

Psoriasis like skin lesion model was established by continuously applying imiquimod on the back skin of normal mice and CCR6-/- mice for 7 days. The therapeutic and preventive effects of glycyrrhetinic acid (GA) on the model were observed and compared. The severity of skin injury is estimated through clinical PASI scores and histopathological examination. qRT-PCR and multiple cytoline assay were explored to detect the expression levels of cytokines in animal dorsal skin lesions and keratinocyte line HaCaT cells, respectively. The dermis and epidermis of the mouse back were separated for the detection of CCL20 expression. Transcription factor assay was applied to screen, and luciferase activity assay to validate transcription factors regulated by GA. Technology of surface plasmon laser resonance with LC-MS (SPR-MS), molecular docking, and enzyme activity assay were used to identified the target proteins for GA. Finally, we synthesized different derivatives of 18beta-GA and compared their effects, as well as glycyrrhetinic acid (GL), on the skin lesion of imiquimod-induced mice to evaluate the active groups of 18beta-GA.

RESULTS

18β-glycyrrhetinic acid (GA) improved IMQ-induced psoriatic lesions, and could specifically reduce the chemokine CCL20 level of the epidermis in lesion area, especially in therapeutic administration manner. The process was mainly regulated by transcription factor ATF2 in the keratinocytes. In addition, GUSB was identified as the primary target of 18βGA. Our findings indicated that the subject on molecular target research of glycyrrhizin should be glycyrrhetinic acid (GA) instead of glycyrrhizic acid (GL), because GL showed little activity in vitro or in vivo. Apart from that, α, β, -unsaturated carbonyl in C11/12 positions was crucial or unchangeable to its activity of 18βGA, while proper modification of C3 or C30 position of 18βGA may vastly increase its activity.

CONCLUSION

Our research indicates that 18βGA exerted its anti-psoriasis effect mainly by suppressing ATF2 and downstream molecule CCL20 predominately through α, β, -unsaturated carbonyl at C11/12 position binding to GUSB in the keratinocytes, and then broke the feedback loop between keratinocytes and CCR6-expressing immune cells. GA has more advantages than GL in the external treatment of psoriasis. A highlight of this study is to investigate the influence of special active groups on the pharmacological action of a natural product, inspired by the molecular docking result.

A Rare Phenomenon of Lithium-Associated Acne Inversa: A Case Series and Literature Review

Lithium use has been associated with dermatological issues, including psoriasis, folliculitis, and acneiform outbreaks. The lithium dosage and the therapeutic range of serum lithium levels are closely correlated with the frequency of cutaneous adverse effects. Lithium-induced acne inversa is a less well-known adverse effect, causing significant morbidity. Acne inversa (hidradenitis suppurativa) is a chronic inflammatory illness of the skin seen in the folds of the skin and face and distinguished by the presence of painful nodules and fistulas, as well as a propensity for tissue fibrosis. We report two cases of bipolar affective disorder who received long-term lithium treatment and experienced acne inversa during treatment, which subsided once the lithium was withdrawn.

Neutrophils in Psoriasis

Neutrophils are the most abundant innate immune cells. The pathogenic roles of neutrophils are related to chronic inflammation and autoimmune diseases. Psoriasis is a chronic systemic inflammatory disease affecting ~2–3% of the world population. The abundant presence of neutrophils in the psoriatic skin lesions serves as a typical histopathologic hallmark of psoriasis. Recent reports indicated that oxidative stress, granular components, and neutrophil extracellular traps from psoriatic neutrophils are related to the initial and maintenance phases of psoriasis. This review provides an overview on the recent (up to 2019) advances in understanding the role of neutrophils in the pathophysiology of psoriasis, including the effects of respiratory burst, degranulation, and neutrophil extracellular trap formation on psoriatic immunity and the clinical relationships.

Neutrophils and redox stress in the pathogenesis of autoimmune disease

Polymorphonuclear leukocytes, or neutrophils, are specialist phagocytic cells of the innate immune system. Their primary role is host defence against micro-organisms, which they kill via phagocytosis, followed by release of reactive oxygen species (ROS) and proteolytic enzymes within the phagosome. ROS are generated via the action of the NADPH oxidase (also known as NOX2), in a process termed the 'Respiratory Burst'. This process consumes large amounts of oxygen, which is converted into the highly-reactive superoxide radical O₂^- and H₂O₂. Subsequent activation of myeloperoxidase (MPO) generates secondary oxidants and chloroamines that are highly microbiocidal in nature, which together with proteases such as elastase and gelatinase provide a toxic intra-phagosomal environment able to kill a broad range of micro-organisms. However, under certain circumstances such as during an auto-immune response, neutrophils can be triggered to release ROS and proteases extracellularly causing damage to host tissues, modification of host proteins, lipids and DNA and dysregulation of oxidative homeostasis. This review describes the range of ROS species produced by human neutrophils with a focus on the implications of neutrophil redox products in autoimmune inflammation.

Lithium and psoriasis: what primary care and family physicians should know

OBJECTIVE

This review focuses on the association of lithium treatment and psoriasis. The mechanism of action of lithium in causing psoriasis and the clinical presentation of psoriasis secondary to lithium treatment are considered.

DATA SOURCES

A search of the literature from 1949 to 2007 was performed using MEDLINE, with the following search terms: lithium, psoriasis, skin, dermatology, and psychodermatology.

DATA SYNTHESIS

Lithium is involved in a variety of cutaneous reactions including psoriasis, which may present as exacerbation of preexisting psoriasis, induction of de novo psoriasis, pustular psoriasis, nail changes, and psoriatic arthropathy. The appearance of psoriatic lesions may occur at normal therapeutic serum lithium levels. The refractory period for the development of psoriatic lesions is variable and generally longer in induction and shorter in exacerbation of psoriasis. Lithium-induced psoriasis is often resistant to conventional treatment modalities, and some cases may require dose reduction or discontinuation of lithium treatment.

CONCLUSION

Lithium is the mainstay of treatment in bipolar disorder and is associated with a variety of cutaneous side effects including psoriasis. Primary care providers and family physicians should be knowledgeable about the association of lithium and its dermatologic side effects. Early recognition and management could be beneficial in avoiding the issues of noncompliance and further deterioration of mood symptoms secondary to obviously disfiguring skin appearance. Primary care, psychiatry, and dermatology liaison services will prove helpful in managing these patients.

Drug-Induced Psoriasis: An Evidence-Based Overview and the Introduction of Psoriatic Drug Eruption Probability Score

Psoriasis is a common skin disorder that needs a long-term management, not only because, of its prevalence but also because of the profound impact it can have on patients quality of life. Drugs may result in exacerbation of a preexisting psoriasis, in induction of psoriatic lesions on clinically uninvolved skin in patients with psoriasis, or in precipitation of the disease in persons without family history of psoriasis or in predisposed individuals. The knowledge of the drugs that may induce, trigger, or exacerbate the disease is of primary importance in clinical practice. By reviewing the literature, there are many reports on drug-induced psoriasis, but the data are not univocal. We propose, when possible, the use of a probability score from the authors to obtain a better classification and further understanding of drug-induced psoriasis.

Synthesis of Pyrimidine Derivatives Possessing an Antioxidative Property and Their Inhibitory Effects on Picryl Chloride-Induced Contact Hypersensitivity Reaction

We conducted a preliminary structure-activity relationship (SAR) study of some barbituric acid and uracil derivatives against the picryl chloride-induced contact hypersensitivity reaction. The introduction of an antioxidative moiety to the side chain of the C(6)-position of uracil was effective against this model. The introduction of dimethoxyphenol (8b) or dimethylphenol (8c) instead of di-t-butylphenol (8a) as an antioxidative moiety gave diminished activities, so, the reactive oxygen would contribute to the inflammation of this model, and an antioxidative activity was required for exhibiting the inhibitory activity. The inhibitory activity was significantly affected by the substituent at the N(1)-phenyl moiety.

Decreased expression levels of L-selectin on subsets of leucocytes and increased serum L-selectin in severe psoriasis

L-selectin is a leucocyte adhesion molecule involved in leucocyte interactions with vascular endothelial cells. Following leucocyte activation L-selectin is endoproteolytically released from the cell surface. To assess whether psoriasis vulgaris results in systemic leucocyte activation, we examined expression levels of L-selectin on subsets of peripheral blood leucocytes from patients with psoriasis (n = 25) and normal control subjects. Serum levels of soluble L-selectin were quantified by ELISA in patients with psoriasis (n = 75), pustulosis palmaris et plantaris, and contact dermatitis, as well as normal control subjects. Psoriasis severity was evaluated by psoriasis area and severity index (PASI). L-selectin expression levels on CD4+ T cells, B cells, monocytes, and neutrophils from patients with severe-type psoriasis (PASI > or = 15) was significantly decreased compared with leucocytes from normal control subjects. Furthermore, L-selectin expression on CD4+ T cells showed good inverse correlation with PASI scores. Monocyte L-selectin expression was restored when the skin lesions of psoriasis were remitted. The frequencies of L-selectin+ CD4+ T cells or L-selectin+ CD8+ T cells from patients with psoriasis were almost normal. Serum L-selectin levels in patients with severe-type psoriasis were significantly higher than those in normal control subjects. These results suggest that subsets of leucocytes may be activated in psoriasis, and that L-selectin expression levels on some leucocyte subsets, especially CD4+ T cells, tend to correlate with disease severity of psoriasis.

Synthesis and biological evaluation of CX-659S and its related compounds for their inhibitory effects on the delayed-type hypersensitivity reaction

In order to find novel nonsteroidal compounds possessing an inhibitory activity against delayed-type hypersensitivity (DTH) reactions, we conducted random screening using a picryl chloride (PC)-induced contact hypersensitivity reaction (CHR) in mice, and found compound 1 as a lead compound. Then we synthesized and evaluated an extensive series of 5-carboxamidouracil derivatives focused on both the uracil and the antioxidative moieties. Among them, we found that the hindered phenol moiety was necessary to exhibit the activities; especially, compounds 28a-28c having the partial structure of vitamin E were found to exert potent activities against the DTH reaction by both oral and topical administration. And compound 28c showed antioxidative activity against lipid peroxidation with an IC50 of 5.9 microM. Compound 28c (CX-659S) was chosen as a candidate drug for the treatment of cutaneous disorders such as atopic dermatitis and allergic contact dermatitis.

Lithium-induced follicular hyperkeratosis

A wide range of cutaneous reactions have been described in association with lithium therapy. Follicular eruptions have been noted briefly, but are not well documented in the dermatological literature. We report a 68-year-old man who developed a florid erythematous follicular eruption on the extensor surfaces of the limbs, with macular truncal erythema 6 months after commencing lithium therapy. His blood lithium levels were within the therapeutic range and there was no clinical evidence of lithium toxicity. Histology of lesional skin showed perifollicular inflammation and follicular plugging. The eruption improved on drug withdrawal. The cutaneous reactions to lithium and possible pathogenic mechanisms are discussed.

Skin inflammation: reactive oxygen species and the role of iron

Superoxide and hydrogen peroxide are reactive oxygen species (ROS) primarily produced by phagocytic cells as a consequence of the process of phagocytosis. This defensive role, may, however, become one of attack when production of ROS is excessive and overwhelms cellular scavenging systems. This happens in situations such as acute inflammation and results in host cell membrane damage, which is particularly prevalent in the presence of transition metal catalysts such as iron and copper. The skin is uniquely vulnerable to this attack being rich in polyunsaturated fatty acids and exposed to high oxygen tensions and ultraviolet light, both of which promote production of ROS. Additionally, the respiratory burst of infiltrating polymorphonuclear leukocytes and macrophages in inflamed skin will produce high local levels of superoxide that can release "catalytic iron" from storage proteins such as ferritin. The role of iron and ROS in the pathogenesis of inflammatory skin disease is discussed as is the possibility of novel therapeutic strategies based on their removal.

Synergistic induction of interleukin-6 by tumor necrosis factor and lithium chloride in mice: possible role in the triggering and exacerbation of psoriasis by lithium treatment

One of the side effects of treatment of manic depressive disease with lithium salts is the triggering or aggravation of psoriasis. In a murine model, subcutaneous (s.c.) injection of a combination of tumor necrosis factor (TNF) and lithium chloride (LiCl) induces a psoriasiform inflammatory reaction. Recent studies suggest that interleukin (IL)-6 and its inducer TNF may play an important role in the pathophysiology of psoriasis. To understand the mechanism involved in the exacerbation of psoriasis by lithium salts, the IL-1, IL-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF) levels in murine skin injected with TNF in combination with LiCl were studied. IL-6 levels in skin extracts of mice treated s.c. with a combination of TNF and LiCl were considerably increased as compared to the levels found in skin extracts from mice treated with TNF or LiCl alone. In contrast, in the same skin extracts IL-1 levels were not changed and GM-CSF was even not detectable. Although less pronounced, increased IL-6 levels could also be found in the sera of mice treated s.c. with TNF and LiCl. Injection with IL-1, interferon-gamma, lipopolysaccharide, or phorbol 12-myristate 13-acetate also induced IL-6 in murine skin. However, these IL-6 levels were not enhanced by co-treatment with LiCl. Likewise, on inflammatory reaction could be seen in mice treated with these agents. These results suggest a role for endogenous TNF and IL-6 in the triggering or aggravation of psoriasis in lithium-treated patients.

Etretinate or cyclosporin-A treatment normalizes the enhanced respiratory burst of polymorphonuclear leukocytes in psoriasis

During a therapeutic trial to treat psoriasis with either etretinate or cyclosporin A (CyA) we measured the respiratory burst activity of polymorphonuclear leukocytes (PMN). Six patients received 0.5-0.75 mg/kg etretinate and 14 patients 2.5-5.0 mg/kg CyA over a period of 10 weeks. The extent of psoriasis was graded by the psoriasis area-and-severity index (PASI score). The respiratory burst of PMN isolated from the peripheral blood was measured employing luminol-enhanced chemiluminescence at weeks 0, 3 and 10 and compared with that of 26 healthy control individuals. PMN were stimulated with zymosan particles, aggregated immunoglobulin (aggIg) and concanavalin A (ConA). Both treatment regimens improved psoriasis; at 10 weeks there was an approximate 40% PASI score reduction under etretinate and an 80% improvement under CyA. Before treatment the respiratory burst was abnormally high under stimulation with the three stimuli in patients (p = 0.021 to less than 0.0001). After 3 to 10 weeks PMN activity normalized in all patients and even tended to drop below values correlating with an improvement in skin lesions. We conclude that the elevated respiratory burst of PMN in psoriasis normalizes under treatment with both etretinate and CyA.

Acneiform eruption induced by lithium carbonate

A 26-year-old female developed a severe acneiform eruption on her face, chest and back soon after she started taking lithium carbonate for psychosis. Histopathological examination revealed it to be folliculitis, rather than true acne. The eruption continued for six months but was resolved three months after discontinuing the drug. It has not reappeared in the following 3 years.

Exacerbation of psoriasis during lithium treatment

Exacerbation of psoriasis was observed in a 28-year-old patient following the addition of lithium carbonate to a treatment regimen of carbamazepine and other drugs for manic-depressive psychosis. The biopsied lesion histologically showed a typical psoriasiform tissue reaction and immunohistochemically, remarkable infiltration of activated helper T cells. Immunologic reaction to lithium in a patch test and a lymphocyte proliferation test could not be demonstrated. The mechanisms of lithium action and their relations to the exacerbation of psoriasis were reviewed. In this patient, although we could not define which effect of lithium was most important, it seemed that an increased blood lithium level combined with simultaneous carbamazepine administration enhanced the triggering effect of lithium and caused the exacerbation of psoriasis.

Superoxide dismutase and myeloperoxidase activity in polymorphonuclear leukocytes, and serum ceruloplasmin and copper levels, in psoriasis

The levels of superoxide dismutase (SOD) and myeloperoxidase (MPO) in polymorphonuclear leukocytes (PMN), and serum ceruloplasmin activity and copper content, were measured in 60 patients with psoriasis and 33 healthy controls. There were no significant differences in the activity of MPO between the patients and the controls. However, SOD activity in PMN was significantly lower in the patients than in the controls. Serum ceruloplasmin activity and copper levels were significantly higher in the psoriatics than in the controls.

Enhanced chemiluminescence production by phagocytosing neutrophils in psoriasis

Using serum-coated zymosan, the generation of reactive oxidants by measurement of chemiluminescence was shown to be significantly enhanced in isolated peripheral psoriatic neutrophils compared to normal controls. This response was observed irrespective of whether zymosan was opsonized with fresh autologous or normal AB serum. However, this increased activity was reduced with zymosan was opsonized with serum that was preheated at 56 degrees C for 30 min. There was no statistical correlation of chemiluminescence activity with degranulation of beta-glucuronidase in either normal or psoriatic subjects. In addition, chemiluminescence produced by normal cells was significantly increased when zymosan was opsonized with psoriatic serum. The plasma membrane-bound enzyme, NAD(P)H oxidase, which produces superoxide in response to phagocytic stimulation, was significantly increased in psoriatic neutrophils compared to normal controls. These data add further evidence for activated neutrophils in psoriasis.

Development of a psoriasis-like syndrome following lithium therapy

A correlation between lithium and psoriasis has been observed. In this paper, the case of a 17-yr-old girl is reported who developed psoriatic lesions after administration of lithium carbonate. Further-more, serum lithium levels in some psoriatic patients are disclosed, and induction of psoriasis by lithium in experimental animals is described. Serum lithium levels in 27 patients were significantly higher (p<0.025) than those of controls. Uninvolved parts of skin tissues obtained from three cases of psoriasis were transplanted to nude mice. After supplementing lithium as the chloride, these skin grafts developed the histologic change characteristic of psoriasis. However, the lithium compound by itself did not increase superoxide production of polymorphonuclear leukocytes in psoriasis.

Myeloperoxidase of polymorphonuclear leukocytes in psoriasis vulgaris

The specific activity of myeloperoxidase (MPO), an enzyme located in the primary granules of polymorphonuclear leukocytes, was measured in patients with psoriasis vulgaris and compared with that in patients with atopic dermatitis and in healthy subjects. MPO catalyzes the oxidation of guaiacol into tetraguaiacol in the presence of H2O2. The activity was determined by photometric measurement of tetraguaiacol. The specific MPO activity showed no statistically significant difference between the healthy subjects and the patients with atopic dermatitis. In comparison to these two groups the specific MPO activity of the psoriatic patients showed a slight reduction which was, however, not statistically significant.

Drugs in exacerbation of psoriasis

Drugs that have been associated with the precipitation or exacerbation of psoriasis include lithium, beta adrenergic receptor blocking agents, and antimalarials. The withdrawal of corticosteroids has been reported to activate pustular psoriasis. Nonsteroidal anti-inflammatory drugs, such as indomethacin, have recently been reported to exacerbate psoriasis, although additional well-controlled studies are still needed. Drugs used for treatment of psoriasis will sometimes cause a flare because of irritation, phototoxicity, or hypersensitivity reaction resulting in a Koebner phenomenon. Because psoriasis is a very complex disease and its activity is often unpredictable, clinical studies on adverse drug effects on psoriasis have been difficult to conduct. This review evaluates clinical, histologic, and biochemical evidence in the literature for drug-associated onset or exacerbation of psoriasis.

Effect of lithium therapy on inflammatory response

Chemiluminescence produced by normal cells was reduced in response to zymosan which was opsonized with serum from patients on prophylactic lithium therapy, compared to control serum from normal subjects (68 +/- 3.1 vs. 93 +/- 3.4 mV/5 X 10(5) cells). Preincubation of normal cells with serum from patients also resulted in reduced chemiluminescence activity when the cells were stimulated with autologous serum-coated zymosan (47 +/- 4.5 vs. 64 +/- 6.3 mV/5 X 10(5) cells). Spontaneous complement conversion was increased in the serum of patients on lithium therapy (46.3 +/- 3.8 vs. 25.3 +/- 2.5% conversion). These studies demonstrated that lithium, at safe therapeutic levels (0.4-0.9 mmol/liter), significantly altered complement conversion and had a marked affect on chemiluminescence activity by normal cells.

The 'metabolic burst' in polymorphonuclear leukocytes from patients with quiescent psoriasis

We report an investigation of peripheral blood polymorphonuclear leukocytes (PMN) from untreated patients with mild, quiescent psoriasis. Four aspects of the 'metabolic burst' were measured to illustrate phagocytosis-related events. These were: myeloperoxidase activity, hydrogen peroxide release, superoxide production and luminol-amplified chemiluminescence. Our study does not support the concept of an intrinsic abnormality of the PMN in psoriasis, but provides additional evidence for disease activity-dependent changes in phagocytic behaviour. Possible interactions with certain humoral factors, the so-called opsonins, are discussed.

Increased in vivo secretory activity of neutrophil granulocytes in patients with psoriasis and palmoplantar pustulosis

The relationship between psoriasis and palmoplantar pustulosis (PPP) is uncertain, as is the role of the neutrophil granulocyte in these conditions. In a previous comparative study of the rate of polymorphonuclear leucocyte (PMN) phagocytosis of IgG- and IgG-C3b-coated particles, an increased uptake rate was found in both diseases. Further information on the in vivo activity of PMNs in these conditions may be obtainable by determining the level of lactoferrin (LF) in serum from such patients, since LF serves as a specific marker of the turnover and activity of the circulating pool of neutrophils. In this study on 19 patients with psoriasis and 20 patients with PPP, elevated levels of LF were found in both conditions. In contrast, the levels of lysozyme and beta 2-microglobulin, which are markers of monocyte-macrophage and lymphocyte activity, respectively, were normal. This suggests the selective activation of neutrophils in these disorders. LF was significantly correlated (P less than 0.05 and 0.001, respectively) to the rates of phagocytosis of IgG- and IgG-C3b-coated particles, but not to the chemotaxis of isolated PMNs. There was no correlation between the severity of the disease and the levels of serum LF. The data suggest the increased in vivo activity of neutrophils in psoriasis and PPP.

Alterations of surface receptors on intralesional neutrophils in pustular psoriasis and palmo-plantar pustulosis

Alterations of binding capacity of surface IgG-Fc and complement receptors were demonstrated in polymorphonuclear neutrophils (PMNs) obtained from the pustular lesions of psoriasis. A marked decrease of C3 receptors, but not of IgG-Fc, was found in PMNs from the lesions of palmo-plantar pustulosis (PPP) and bacterial pustules. PMNs from pustular lesions of psoriasis exhibited only a slight decrease in the number of C3 receptors. No significant decrease in membrane receptors was noted in circulating PMNs from psoriatic patients. We suggest that mechanisms of formation of aseptic subcorneal pustules, mediated by PMN membrane receptors for C3 fragments, are different in pustular psoriasis and PPP.