Establishment of murine model of allergic photocontact dermatitis to ketoprofen and characterization of pathogenic T cells

Stereoselectivity of Interaction of Nonsteroidal Anti-Inflammatory Drug S-Ketoprofen with L/D-Tryptophan in Phospholipid Membranes

The mechanisms of stereoselectivity of the interaction of chiral drugs with active sites of enzymes and cell receptors attract significant attention. The first reason is the difference in therapeutic activity of the enantiomers of the common drugs. Another reason is the interest in the role of chiral inversion of amino acids involved in various peptides in the development of many diseases including Alzheimer’s, Parkinson’s, type II diabetes, and a number of other pathological conditions. In our study we use elementary chemical process—electron transfer (ET) to simulate individual stages of ligand–receptor and enzyme–substrate interactions. In particular, previous studies of photoinduced ET in chiral donor-acceptor dyads consisting of the nonsteroidal anti-inflammatory drug (R/S)-ketoprofen and (L)-tryptophan show the stereo and spin selectivity of ET in diastereomers. The present study is devoted to the interaction of (S)-ketoprofen with L- and D-enantiomers of tryptophan in homogeneous aqueous solution and in phospholipid membranes. The study was done using the NMR technique and molecular modeling. These approaches confirm efficient penetration of ketoprofen into the lipid bilayer and binding with tryptophan molecule. The short-lived paramagnetic intermediates formed during the photoinduced ET from electron donor tryptophan to ketoprofen have been detected using the chemically induced dynamic nuclear polarization (CIDNP) technique. It was found that S-ketoprofen interacts stereoselectively with tryptophan enantiomers in the lipid membrane. The formation of the ketyl radical of ketoprofen under irradiation leads to the oxidation of membrane lipids and may be the cause of ketoprofen phototoxicity. However, in contrast to a homogeneous solution in phosphate buffer saline, where the amino acid tryptophan accelerates the photodecomposition of KP due to intramolecular hydrogen transfer, tryptophan in a lipid membrane significantly reduces the rate of photodegradation due to a reversible electron (or hydrogen) transfer reaction. The stereoselectivity in the rate of KP and lipids decomposition under UV irradiation of S-ketoprofen in the presence of tryptophan enantiomers in lipid bilayer has been detected.

Photochemical Reaction of Ketoprofen with Proteinogenic Amino Acids

Ketoprofen (KP) is one of the most popular nonsteroidal anti-inflammatory drugs; however, drug-induced photosensitivity of KP has been reported as a serious adverse effect. KP incorporated into a protein can produce an allergen under UV irradiation, which causes drug-induced photosensitivity. The photochemistry of KP with 20 kinds of proteinogenic amino acids in phosphate buffer solutions at pH 7.4 was studied by transient absorption spectroscopy. The KP carboxylate anion (KP^-) gave rise to a carbanion via a decarboxylation within a laser pulse, and the carbanion yielded 3-ethylbenzophenone ketyl biradical (3-EBPH) through a proton transfer reaction. Twelve kinds of proteinogenic amino acids obviously accelerated the reaction. Structural information on the complexes of KP docked in the binding sites of human serum albumin (HSA) was obtained by molecular mechanics (MM) and molecular dynamics (MD) calculations. The photochemical reaction of KP^- with amino acid residues in HSA was discussed on the basis of the experimental and calculational results. The information on the reactivity of KP with the amino acids and the stable structures of the KP-HSA complexes should be essential for understanding of the initial step for drug-induced photosensitivity.

Hydrogen Abstraction of Ketoprofen in the Excited Triplet State with Indole and Methylindoles

Relaxation of excited states and reactivity of ketoprofen (KP), one of the most popular nonsteroidal anti-inflammatory drugs, with indole and methylindoles have been studied with transient absorption and quantum chemical calculations. KP in the excited triplet state, ³KP*, abstracted a hydrogen atom from indole and methylindoles to afford a ketyl radical and a counter radical. The bimolecular quenching rate constants of ³KP* by indole and methylindoles, k_q, and the hydrogen atom abstraction rate constants, k_r, were obtained. The k_r values for methylindoles were larger than that for indole; in addition, transient spectra at around 350 nm, assigned to the corresponding C-centered radical, was observed. These results indicate that ³KP* abstracts a hydrogen atom of the methyl group as well as that of N-H in the indole frame. These findings give us information on the reactivity of excited KP in the vicinity of tryptophan in a KP-protein complex, which will ultimately cause photosensitization on human skin.

The impact of mouse strain-specific spatial and temporal immune responses on the progression of neuropathic pain

The present study was designed to investigate the correlation between the spatial and temporal aspects of immune responses and genetic heterogeneity in the progression of peripheral neuropathic pain. To address this issue, we first screened four inbred mouse strains (C57BL/6J, C3H/He, DBA/2, and A/J mice) to identify high- and low-responder strains to mechanical hypersensitivity induced by partial sciatic nerve ligation (pSNL). Among these strains, the C57BL/6J strain showed the highest vulnerability to pSNL-induced mechanical hypersensitivity, whereas the C3H/HeSlc strain was most resistant. C3H/HeSlc mice exhibited a significant increase in CD206-immunoreactivity (anti-inflammatory macrophages) in the dorsal root ganglia (DRG) at 3 and 7 days, and lower Iba1-immunoreactivity (microglia) in the spinal cord from 3 to 14 days after pSNL than C57BL/6J mice. These phenomena might be associated with a decrease in the production of inflammatory factors (interleukin-1β, interleukin-6, and CX3CL1) in the DRG and the poor responsiveness of spinal microglia (i.e. microglial production of IL1β, CCL2, and TNFα) against CX3CL1 in C3H/HeSlc mice. Behavioral experiments using bone marrow (BM) chimeric mice derived by crossing C3H/HeSlc and C57BL/6J strains showed that the strength of mechanical hypersensitivity 3 days following pSNL was inversely correlated with the increase in the ratio of anti-inflammatory/pro-inflammatory DRG macrophages, which was based on the BM-derived hematopoietic cells from donor mice. By contrast, the intensity of Iba1-immunoreactivity (microglia) in the spinal cord was dependent on the phenotypes of recipient mice, but not affected by the phenotypes of BM-derived donor hematopoietic cells. These findings suggest that the strain-specific aspects of DRG macrophages and spinal microglia might be related to the early and late phases of pSNL-induced mechanical hypersensitivity, respectively. This study presents a greater understanding of the differences in neuropathic pain among genetically heterogeneous inbred mouse strains, and provides further insights into the spatial and temporal roles of the immune system in the pathogenesis of neuropathic pain.

Addition of UVA-absorber butyl methoxy dibenzoylmethane to topical ketoprofen formulation reduces ketoprofen-photoallergic reaction

Topical application of ketoprofen (KP) clinically evokes the allergic type of photocontact dermatitis. To avoid this adverse reaction, we investigated the beneficial effect of each ultraviolet (UV) filter that was included in topical ketoprofen formulation. We first tested the inhibitory effects of four UVA filters by a modified local lymph node assay following KP application on the mouse skin and UVA irradiation on the same site. In this assessment, butyl methoxy dibenzoylmethane (BMDBM), when included in KP application, exerted the most effective inhibitory effect on stimulation with KP and UVA. We manufactured topical patch and gel KP applicants containing BMDBM, which retained KP penetration through the skin and KP stability toward UVA. The ability of BMDBM in these formulations to inhibit KP photosensitivity was evaluated by a modified adjuvant and strip method in guinea pigs, and the photoallergic reactions induced by the BMDBM-containing KP applicants were lower than the non-containing ones. It is known that KP has a cross-reactivity with benzophenone upon UVA exposure, but such a photocross-reactivity of BMDBM with KP was not observed in a mouse ear swelling model. The anti-inflammatory effect of the BMDBM-containing KP patch applicant was comparable to the non-containing one. These results suggest that the addition of BMDBM into KP topical formulations is efficacious for inhibition of KP photocontact dermatitis.

Review of allergic and photoallergic contact dermatitis from an ingredient in a medicament vehicle consisting of a compress, poultice, plaster, and tape

The topical application of a medicament vehicle consisting of a compress, poultice, plaster, and tape containing a nonsteroidal anti-inflammatory drug or methyl salicylate is prevalent in Japan. The method is effective for conveying ingredients to the muscles via the skin for the relief of muscular pain. However, an ingredient in the occlusive vehicle can cause allergic and photoallergic contact dermatitis. We summarize cases reported over the past decade and discuss the current strategy for diminishing the risk of allergic and photoallergic contact dermatitis.

Induction of eosinophil-infiltrating drug photoallergy in mice

BACKGROUND

Drug photoallergy is one of the highly incident adverse effects. Several different histological patterns have been recognized.

OBJECTIVE

To establish a murine model of the eosinophil-infiltrating type of drug photoallergy by using afloqualone (AQ), a representative photosensitive drug.

METHODS

AKR/J mice were sensitized by intraperitoneal injection of afloqualone solution (2mg/kg/mouse) and irradiation of shaved abdomen with ultraviolet A light (UVA) (12J/cm(2)). This sensitization procedure was repeated 2-12 times, and 3 days after the last immunization, mice were challenged by a subcutaneous injection of AQ solution and irradiation of the same site with UVA. The draining lymph node cells (LNCs) were used for transfer and cytokine production studies, and the challenged skin was analyzed for chemokine expression.

RESULTS

More than 10 times of sensitization induced a massive infiltrate of eosinophils and lymphocytes at the challenged site. AKR/J mice were a high responder strain. The sensitivity was transferred with 5-8 x 10(7) immune lymph node and spleen cells into naïve mice. CD4(+) T cells were mainly responsible for this sensitivity, since 1 x 10(7) CD4(+) cells alone induced a high level of sensitivity, but CD8(+) T cells evoked the sensitivity to a lesser degree. Culture supernatants from AQ-photoimmuned lymph node cells contained a higher level of IL-4 and lower interferon-gamma than those from mice immunized with dinitrofluorobenzene. Finally, the skin of AQ-photochallenged site exhibited high expression of CCL24/eotaxin-2, a chemokine for eosinophils.

CONCLUSION

It is suggested that eosinophilic drug photoallergy is mediated by sensitized Th2 cells and locally produced eosinophil-attracting chemokines.

Skin application of the nonsteroidal anti-inflammatory drug ketoprofen downmodulates the antigen-presenting ability of Langerhans cells in mice

BACKGROUND

Ketoprofen (KP) is widely used as a topical nonsteroidal anti-inflammatory drug that inhibits prostaglandin (PG) biosynthesis. As PGE(2) upregulates the antigen-presenting activity of Langerhans cells (LCs), i.e. migration to lymph nodes and expression of immunocompetent molecules, modulation of LC functions resulting from topical application of KP is an issue to be clarified.

OBJECTIVES

To investigate the in vivo effect of KP application to the skin and the in vitro effect of KP addition to the culture on the antigen-presenting ability of murine LCs. Methods Ears of BALB/c mice were painted with picryl chloride (PCl) hapten, KP or both. An immunofluorescence study of epidermal sheets and a flow cytometric analysis of epidermal cell suspensions from the treated ears were performed.

RESULTS

PCl altered the morphology of LCs and reduced their number, and simultaneous application of 10% KP maintained LC morphology and number. KP at 5% or 10% clearly decreased the PCl-augmented expression of major histocompatibility complex class II and CD86 on LCs. In cultivation of freshly isolated epidermal cells, 5 mmol L(-1) KP inhibited the culture-promoted expression of these molecules on LCs, whereas 100 micromol L(-1) indomethacin was not inhibitory. The further addition of PGE(2) to the KP-containing epidermal cell culture did not restore the expression of these molecules. Moreover, topical application of 10% KP to the sensitizing sites suppressed the development of contact hypersensitivity to PCl.

CONCLUSIONS

KP may have the potential to inhibit the antigen-presenting ability of LCs, in a PGE(2)-independent manner.

Epidermal chemokines and modulation by antihistamines, antibiotics and antifungals

Growing evidence has demonstrated that chemokines released from epidermal cells control inflammatory skin diseases. Keratinocytes elaborate both Th1- and Th2-associated chemokines, although the former is more abundantly produced than the latter. Downmodulation of keratinocyte production of chemokines is one of the therapeutic approaches for cutaneous inflammatory disorders. Recent observations have shown that keratinocyte chemokine production can be modulated by well-used drugs, including antihistamines, antibiotics and antifungals. Utilization of the beneficial side effects of these drugs may by clinically valuable.

Stimulation of Langerhans cells with ketoprofen plus UVA in murine photocontact dermatitis to ketoprofen

BACKGROUND

Ketoprofen (KP) clinically evokes the allergic type of photocontact dermatitis when applied to the skin and irradiated with ultraviolet A (UVA). We have established a murine model of photocontact dermatitis to KP, which is a T cell-mediated delayed type hypersensitivity.

OBJECTIVE

To further explore the mechanism underlying this sensitivity, we investigated whether KP plus UVA activates the antigen-presenting ability of Langerhans cells (LCs).

METHODS

We analyzed the expression of surface molecules on LCs in the murine epidermis treated with KP plus UVA by immunohistochemistry and flow cytometry. Changes in the cytokine expression of epidermal cells from KP-phototreated skin were also examined by real-time PCR.

RESULTS

LCs became larger after treatment with KP plus UVA. The number of LCs was significantly decreased 2-3 days after KP phototreatment and recovered on day 5. A flow cytometric analysis revealed that KP plus UVA increased the percentage of LCs that highly expressed MHC class II, CD86, CD80, CD54 and CD40, whereas neither KP nor UVA alone enhanced the expression. KP phototreatment augmented the expression of I-A and CD86 on LCs in KP and UVA dose-dependent manners. A real-time PCR analysis of KP-phototreated skin showed that the expression of mRNA for IL-1alpha and GM-CSF was immediately increased after treatment.

CONCLUSION

A photosensitizing regimen of KP plus UVA activates LCs at least partly by stimulating keratinocytes to produce cytokines. Two strains of mice (BALB/c and AKR) differ in responsiveness to KP and the difference is not related to the activation of keratinocytes.