Jingfang granules exert anti-psoriasis effect by targeting MAPK-mediated dendritic cell maturation and PPARγ-mediated keratinocytes cell cycle progression in vitro and in vivo.

BACKGROUND: Jingfang granules (JFG), derived from JingFangBaiDu San (JFBDS), are a traditional herbal formulas used for the treatment of respiratory tract infections. They were initially prescribed to treat skin disease, such as psoriasis in Chinese Taiwan, but are not widely used for psoriasis treatment in mainland China because of the lack of anti-psoriasis mechanism research. PURPOSES: The present study was designed to evaluate the anti-psoriasis effect of JFG and reveal the correlated mechanisms of JFG in vivo and in vitro using network pharmacology, UPLC-Q-TOF-MS technology and molecular biotechnology methods. RESULTS: An imiquimod-induced psoriasis-like murine model was used to verify the anti-psoriasis effect in vivo, with inhibition of lymphocytosis and CD3+CD19+B cell proliferation in the peripheral blood and prevention of the activation of CD4+IL17+T cells and CD11c+ MHC Ⅱ+ dendritic cells (DCs) in the spleen. Network pharmacology analysis demonstrated that the targets of the active components were significantly enriched in pathways involved in cancer, inflammatory bowel disease and rheumatoid arthritis, which were closely related to cell proliferation and immune regulation. The drug-component-target networks and molecular docking analysis demonstrated the active ingredients to be luteolin, naringin and 6'-feruloylnodakenin, which had a good binding affinity to PPARγ, p38a MAPK and TNF-a. Finally, UPLC-Q-TOF-MS analysis to validate the active ingredients in drug-containing serum and in vitro experiments showed that JFG inhibited the maturation and activation of BMDCs via the p38a MAPK signaling pathway and translocation of the agonist PPARγ into the nuclei to reduce the activity of NF-κB/STAT3 inflammatory signaling pathway in keratinocytes. CONCLUSIONS: Our study demonstrated that JFG improved psoriasis by inhibiting the maturation and activation of BMDCs and proliferation and inflammation of keratinocytes, which may facilitate the applications of JFG in anti-psoriasis therapy in clinical settings.

Baicalin Ameliorates Imiquimod-Induced Psoriasis-Like Inflammation in Mice.

Baicalin is the main flavonoid from the roots of an important medicinal plant, Scutellaria baicalensis, which shows a variety biological activities. Psoriasis is a chronic immune-mediated inflammatory disease that affects the skin. The unmet need of psoriasis is that many patients do not respond adequately to available clinical treatment. In this study, we found that baicalin showed inhibited dermal inflammation in a murine model of psoriasis via topical application of imiquimod. After a 5-day topical imiquimod application, baicalin or the control vehicle cream was to applied to the lesions of BALB/c mice for a further 4 days. The erythema, scaling, and thickness of the epidermal layer significantly improved in the baicalin-treated mice. The levels of interleukin-17A, interleukin-22, interleukin-23, and tumor necrosis factor in the skin significantly decreased after baicalin treatment. Baicalin also inhibited imiquimod-induced interleukin-17A production in skin draining lymph node cells. The infiltration of γδ T cells into the skin lesions induced by imiquimod was also suppressed after baicalin treatment. These results suggest that baicalin inhibited skin inflammation through the inhibition of the interleukin-17/interleukin-23 axis in a murine model of psoriasis.

Gold lotion from citrus peel extract ameliorates imiquimod-induced psoriasis-like dermatitis in murine.

BACKGROUND: Gold lotion (GL), a natural mixed product made from the peels of six citrus fruits, has recently been identified as possessing anti-oxidative, anti-inflammatory, and immunomodulatory effects. GL has been used to protect skin against UV-induced damage, but its activity against psoriasis, a chronic autoimmune skin disease caused by dysregulation between immune cells and keratinocytes, is not known. We therefore evaluated the effect of GL on imiquimod (IMQ)-induced psoriasis-like inflammation in mice. RESULTS: GL treatment significantly attenuated IMQ-induced psoriasis-like symptoms in mice. The inflammatory cytokines upregulated by IMQ in skin lesions were also inhibited by feeding GL. In addition, GL treatment reduced the infiltration of CD4+ T cells/neutrophils in skin lesions and the percentage of IL-17-/IL-22-producing T cells in lymph nodes. Furthermore, GL impaired IMQ-induced type I interferon production by plasmacytoid dendritic cells (pDCs) in vitro. CONCLUSION: Our results indicate GL can act to suppress the initiation of psoriasis and strongly suggest that GL may have potential to be applied to the treatment of psoriasis. © 2018 Society of Chemical Industry.

Development of nanoparticles from natural lipids for topical delivery of thymol: Investigation of its anti-inflammatory properties.

Wound healing involves the integration of biological and molecular events and, in case of chronic wounds, the use of drugs can be associated to side effects. Therefore, there is a search for alternatives therapeutics that encompass minimal toxicity. The use of natural compounds is an attractive approach for treating inflammatory disorders, wounds and burns. In this context, thymol has antimicrobial, antioxidant and antiseptic properties and is a promising compound in wound healing and inflammation management. However, essential oils and their constituents such as thymol present high volatility and can also easily decompose, thereby the encapsulation of these compounds into nanoparticles may be an efficient approach to modulate the release of the active ingredient, to increase the physical stability and to eventually reduce the toxicity. The aims of this work were to encapsulate thymol in nanostructured lipid carriers (NLCs) composed of natural lipids and assess its in vivo anti-inflammatory and antipsoriatic activity. The carrier containing thymol was produced by sonication method and showed 107.7 (±3.8) nm of size, zeta potential of -11.6 (±2.9) mV and entrapment efficiency of 89.1 (±4.2)%. Thymol-NLCs were incorporated into a gel and the final formulation presented rheological characteristics and pH suitable for topic application. In addition, the gel containing thymol-NLCs was tested in vivo on two different mouse models of skin inflammation, showing anti-inflammatory activity. Finally, this formulation was tested in an imiquimod-induced psoriasis mouse model and showed improved healing, compared to negative control. Therefore, thymol-NLCs is an interesting formulation for future treatment of inflammatory skin diseases.

Natural Modulators of Endosomal Toll-Like Receptor-Mediated Psoriatic Skin Inflammation.

Psoriasis is a chronic inflammatory autoimmune disease that can be initiated by excessive activation of endosomal toll-like receptors (TLRs), particularly TLR7, TLR8, and TLR9. Therefore, inhibitors of endosomal TLR activation are being investigated for their ability to treat this disease. The currently approved biological drugs adalimumab, etanercept, infliximab, ustekinumab, ixekizumab, and secukizumab are antibodies against effector cytokines that participate in the initiation and development of psoriasis. Several immune modulatory oligonucleotides and small molecular weight compounds, including IMO-3100, IMO-8400, and CPG-52364, that block the interaction between endosomal TLRs and their ligands are under clinical investigation for their effectiveness in the treatment of psoriasis. In addition, several chemical compounds, including AS-2444697, PF-05387252, PF-05388169, PF-06650833, ML120B, and PHA-408, can inhibit TLR signaling. Although these compounds have demonstrated anti-inflammatory activity in animal models, their therapeutic potential for the treatment of psoriasis has not yet been tested. Recent studies demonstrated that natural compounds derived from plants, fungi, and bacteria, including mustard seed, Antrodia cinnamomea extract, curcumin, resveratrol, thiostrepton, azithromycin, and andrographolide, inhibited psoriasis-like inflammation induced by the TLR7 agonist imiquimod in animal models. These natural modulators employ different mechanisms to inhibit endosomal TLR activation and are administered via different routes. Therefore, they represent candidate psoriasis drugs and might lead to the development of new treatment options.

Imiquimod-induced psoriasis-like inflammation in differentiated Human keratinocytes: Its evaluation using curcumin.

Psoriasis is considered to be a systemic disease of immune dysfunction. It is still unclear what triggers the inflammatory cascade associated with psoriasis but recent evidences suggest the vital role of IL-23/IL-17A cytokine axis in etiology of psoriasis. Several studies have been conducted in psoriatic-like animal models but ethical issues and complexity surrounding it halts the screening of new anti-psoriatic drug candidates. Hence, in this study, we developed a new in-vitro model for psoriasis using imiquimod (IMQ) induced differentiated HaCaT cells which could be used for screening of new anti-psoriatic drug candidates. The differentiated HaCaT cells were treated with IMQ (100µM) to induce psoriatic like inflammation and its effect was investigated using a natural anti-psoriatic compound, curcumin. The proliferation of psoriatic-like cells was inhibited by curcumin at 25 and 50µM concentrations. The psoriatic-like cells decreased in number with increase in apoptotic and dead cells upon curcumin treatment. Curcumin inhibited the proliferation of IMQ-induced differentiated HaCaT cells (Psoriatic-like cells) by down-regulation of pro-inflammatory cytokines, interleukin-17, tumor necrosis factor-α, interferon-γ, and interleukin-6. Apart from this, curcumin significantly enhanced the skin-barrier function by up-regulation of involucrin (iNV) and filaggrin (FLG), the regulators of epidermal skin barrier. The IMQ-induced differentiated HaCaT in vitro model recapitulated some aspects of the psoriasis pathogenesis similar to murine model. Henceforth, we conclude that this model may be used for rapid screening of anti-psoriatic drug candidates and warrant further mechanistic studies.

Paeonol ameliorates imiquimod-induced psoriasis-like skin lesions in BALB/c mice by inhibiting the maturation and activation of dendritic cells.

Paeonol, an active component derived from the traditional Chinese medicine Cortex Moutan, possesses anti-inflammatory, analgesic, antioxidant and anti-allergic properties. Psoriasis is a chronic, recurrent, inflammatory dermatosis accompanied by excessive activation of Toll­like receptors (TLRs) in dendritic cells (DCs), which are primarily responsible for initiating an immune response. We investigated the effect of paeonol on inflammation in an imiquimod (IMQ)-induced psoriasis-like mouse model and murine bone marrow-derived dendritic cells (BMDCs) stimulated by R848. Mice were intragastrically administered 100 mg/kg (high), 50 mg/kg (medium) and 25 mg/kg (low) paeonol, respectively. We evaluated inflammation of psori-asis­like lesions based on histological changes, protein levels of myeloid differentiation factor 88 (MyD88) and TLR8 in skin lesions by western blotting, and levels of CD11c+ DCs in skin by immunoassay and in spleens by flow cytometry. Inflammatory cytokines [interleukin (IL)-23, IL-12 and IL-1ß] in skin lesions and BMDCs were also assessed by RT-PCR and ELISA. Application of paeonol decreased IMQ-induced keratinocyte proliferation, and infiltration of CD3+ cells, while the treatment ameliorated CD11c+ cells in the spleen and skin, and reduced MyD88 and TLR8 proteins in skin lesions. Paeonol inhibited IMQ-induced mRNA expression of IL-23, but not IL-12 and IL-1ß in BMDCs, along with significantly lower levels of DCs expressing MHCⅡ, CD80 and CD86 in vitro. These results indicate that paeonol suppresses the maturation and activation of DCs by decreasing MyD88 and TLR8 proteins in the TLR7/8 signaling pathway which finally alleviates psoriasis­like skin lesions. The TLR7/8 signaling pathway in DCs provides an important insight into the mechanism of psoriasis, and paeonol may be a potent therapeutic drug for psoriasis.

Topical imiquimod 5% as an alternative therapy in periocular basal cell carcinoma in two patients with surgical contraindication. / Imiquimod 5% tópico como terapia alternativa en carcinoma basocelular periocular en 2 pacientes con contraindicación quirúrgica.

CLINICAL CASES: The cases are presented of two patients with periocular basal cell carcinoma of the eyelid who received topical imiquimod 5%, with a good response. Both had a functional state that contraindicated surgical treatment. CONCLUSION: Imiquimod cream 5% was shown to be an effective alternative to surgical treatment of periocular basal cell carcinoma, especially in those cases where surgery is not possible.

Enhanced stability of tristetraprolin mRNA protects mice against immune-mediated inflammatory pathologies.

Tristetraprolin (TTP) is an inducible, tandem zinc-finger mRNA binding protein that binds to adenylate-uridylate-rich elements (AREs) in the 3'-untranslated regions (3'UTRs) of specific mRNAs, such as that encoding TNF, and increases their rates of deadenylation and turnover. Stabilization of Tnf mRNA and other cytokine transcripts in TTP-deficient mice results in the development of a profound, chronic inflammatory syndrome characterized by polyarticular arthritis, dermatitis, myeloid hyperplasia, and autoimmunity. To address the hypothesis that increasing endogenous levels of TTP in an intact animal might be beneficial in the treatment of inflammatory diseases, we generated a mouse model (TTPΔARE) in which a 136-base instability motif in the 3'UTR of TTP mRNA was deleted in the endogenous genetic locus. These mice appeared normal, but cultured fibroblasts and macrophages derived from them exhibited increased stability of the otherwise highly labile TTP mRNA. This resulted in increased TTP protein expression in LPS-stimulated macrophages and increased levels of TTP protein in mouse tissues. TTPΔARE mice were protected from collagen antibody-induced arthritis, exhibited significantly reduced inflammation in imiquimod-induced dermatitis, and were resistant to induction of experimental autoimmune encephalomyelitis, presumably by dampening the excessive production of proinflammatory mediators in all cases. These data suggest that increased systemic levels of TTP, secondary to increased stability of its mRNA throughout the body, can be protective against inflammatory disease in certain models and might be viewed as an attractive therapeutic target for the treatment of human inflammatory diseases.

Keloids and Hypertrophic Scars: A Spectrum of Clinical Challenges.

Since their earliest description, keloids and hypertrophic scars have beleaguered patients and clinicians alike. These scars can be aesthetically disfiguring, functionally debilitating, emotionally distressing, and psychologically damaging, culminating in a significant burden for patients. Our current understanding of keloid pathophysiology has grown and continues to advance while molecular biology, genetics, and technology provide ever-deepening insight into the nature of wound healing and the pathologic perturbations thereof. Greater understanding will lead to the development and application of refined therapeutic modalities. This article provides an overview of our current understanding of keloids, highlighting clinical characteristics and diagnostic criteria while providing a comprehensive summary of the many therapeutic modalities available. The proposed mechanism, application, adverse events, and reported efficacy of each modality is evaluated, and current recommendations are summarized.

Therapeutic and immunomodulatory effects of glucosamine in combination with low-dose cyclosporine a in a murine model of imiquimod-induced psoriasis.

Although cyclosporine A (CsA) is a potent immunomodulating agent and is commonly used as a systemic agent for the management of psoriasis patients, current clinical treatments are not always effective due to the clinical inefficacy of low-doses and numerous harmful effects of higher doses. Currently, the combined use of two other systemic drugs often has better therapeutic efficacy and is safer than low or high dose of a single drug. Glucosamine (Glu) also has immunomodulatory properties for autoimmune diseases. The aims of our study were to investigate the therapeutic efficacy of Glu in combination with low-dose CsA on imiquimod (IMQ)-induced psoriasis-like dermatitis in mice and to determine its immunomodulatory mechanism. We found that combined treatment with Glu (300 mg/kg) and low-dose (10 or 20mg/kg) CsA strongly ameliorated the development of psoriasis-like skin lesions and reduced the levels of Th1 cytokine (TNF-α) and Th17 cytokines (IL-17, IL-22, and IL-23) in the serum and dorsal skin. Histological findings also showed that the thickening of epidermis, stratum corneum, and inflammatory cell infiltration. Particularly, these combined treatments increased the number of CD4(+)CD25(+) regulatory T (Treg) cells in splenic. These results suggest that use of a combination of each drug might be used as an efficacious and safe alternative therapeutic strategy, as well as may provide an immunomodulatory approach for T cell-mediated autoimmune diseases, including psoriasis.

Imiquimod for anogenital warts in non-immunocompromised adults.

BACKGROUND: 30% of people with anogenital warts (AGW) have spontaneous regression of lesions but there is no way to determine whether a specific lesion will remain. There are a wide range of options available for treating people with AGW and selection is based on clinician's experience, patient preferences and adverse effects. The imiquimod could offer the advantages of patient-applied therapies without incurring the limitations of provider-administered treatments. OBJECTIVES: To assess the effectiveness and safety of imiquimod for the treatment of AGW in non-immunocompromised adults. SEARCH METHODS: We searched the Cochrane Sexually Transmitted Infections Group Specialized Register (15 April 2014), CENTRAL (1991 to 15 April 2014), MEDLINE (1946 to 15 April 2014), EMBASE (1947 to 15 April 2014), LILACS (1982 to 15 April 2014), World Health Organization International Clinical Trials Registry (ICTRP) (15 April 2014), ClinicalTrials.gov (15 April 2014), Web of Science (2001 to 15 April 2014) and OpenGrey (15 April 2014). We also handsearched conference proceedings, contacted trial authors and reviewed the reference lists of retrieved studies. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing the use of imiquimod with placebo, any other patient-applied or any other provider-administered treatment (excluding interferon and 5-fluorouracil which are assessed in other Cochrane Reviews) for the treatment of AGW in non-immunocompromised adults. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trials for inclusion, extracted data and assessed risk of bias. We resolved any disagreements through consensus. The quality of the evidence was assessed using the GRADE approach. MAIN RESULTS: Ten RCTs (1734 participants) met our inclusion criteria of which six were funded by industry. We judged the risk of bias of the included trials as high. Six trials (1294 participants) compared the use of imiquimod versus placebo. There was very low quality evidence that imiquimod was superior to placebo in achieving complete and partial regression (RR 4.03, 95% CI 2.03 to 7.99; RR 2.56, 95% CI 2.05 to 3.20, respectively). When compared with placebo, the effects of imiquimod on recurrence (RR 2.76, 95% CI 0.70 to 10.91), appearance of new warts (RR 0.76, 95% CI 0.58 to 1.00) and frequency of systemic adverse reactions (RR 0.91, 95% CI 0.63 to 1.32) were imprecise. We downgraded the quality of evidence to low or very low. There was low quality evidence that imiquimod led to more local adverse reactions (RR 1.73, 95% CI 1.18 to 2.53) and pain (RR 11.84, 95% CI 3.36 to 41.63).Two trials (105 participants) compared the use of imiquimod versus any other patient-applied treatment (podophyllotoxin and podophyllin). The estimated effects of imiquimod on complete regression (RR 1.09, 95% CI 0.80 to 1.48), partial regression (RR 0.77, 95% CI 0.40 to 1.47), recurrence (RR 0.49, 95% CI 0.21 to 1.11) or the presence of local adverse reactions (RR 1.24, 95% CI 1.00 to 1.54) were imprecise (very low quality evidence). There was low quality evidence that systemic adverse reactions were less frequent with imiquimod (RR 0.30, 95% CI 0.09 to 0.98).Finally, two trials (335 participants) compared imiquimod with any other provider-administered treatment (ablative methods and cryotherapy). There was very low quality of evidence that imiquimod did not have a lower frequency of complete regression (RR 0.84, 95% CI 0.56 to 1.28). There was very low quality evidence that imiquimod led to a lower rate of recurrence during six-month follow-up (RR 0.24, 95% CI 0.10 to 0.56) but this did not translate in to a lower recurrence from six to 12 months (RR 0.71, 95% CI 0.40 to 1.25; very low quality evidence). There was very low quality evidence that imiquimod was associated with less pain (RR 0.30, 95% CI 0.17 to 0.54) and fewer local reactions (RR 0.55, 95% CI 0.40 to 0.74). AUTHORS' CONCLUSIONS: The benefits and harms of imiquimod compared with placebo should be regarded with caution due to the risk of bias, imprecision and inconsistency for many of the outcomes we assessed in this Cochrane Review. The evidence for many of the outcomes that show imiquimod and patient-applied treatment (podophyllotoxin or podophyllin) confer similar benefits but fewer systematic reactions with the Imiquimod, is of low or very low quality. The quality of evidence for the outcomes assessing imiquimod and other provider-administered treatment were of very low quality.

Efficacy of combination therapy of oral zinc sulfate with imiquimod, podophyllin or cryotherapy in the treatment of vulvar warts.

AIM: Zinc sulfate is beneficial in the treatment of epithelial warts. We conducted this study to compare the efficacy of combination therapy of oral zinc sulfate with conventional treatments in the treatment of vulvar warts. MATERIAL AND METHODS: This study was a randomized controlled trial. The sample size was 42 in each group. Women aged 20-50 years were placed by the block randomized method into six groups: the podophyllin-, imiquimod- and cryotherapy-treated groups, and another three groups receiving 8-week combination therapy of 400 mg oral zinc sulfate with one of the above-mentioned treatments. Data were analyzed using anova and Fischer's exact test with spss16. RESULTS: A total of 228 patients were recruited and completed the study in six treatment groups. No significant difference was observed in the response to treatment among these groups. Relapse after 6 months was significantly higher in the podophyllin-, imiquimod- and cryotherapy-treated patients compared to patients receiving these treatments in combination with oral zinc sulfate (P<0.05). CONCLUSIONS: Combined therapy of oral zinc sulfate with conventional treatments of vulvar warts appears to reduce the relapse rate.

Vagarious successful treatment of recalcitrant warts in combination with CO2 laser and imiquimod 5% cream.

BACKGROUND: Imiquimod 5% cream is widely regarded as a safe and effective option when treating recalcitrant warts, owing to the ointment's negligible side effects. However, our observations highlighted case of a patient incurring severe adverse reactions due to application of the cream, although the treatment proved successful in curing recalcitrant warts which had developed on the external auditory canal and external ear. METHODS: All lesions were entirely removed with short-pulsed CO2 laser. As soon as the wound-healing process was completed, imiquimod 5% cream was self-applied on the healing wounds once daily for 5 days per week in a total of 2 weeks. RESULTS: The patient appeared normal after the CO2 laser treatment and experienced severe redness, itching, exudation, and incrustation after a 2-week imiquimod 5% cream therapy. All lesions showed no recurrence during the 12-month followed-up process. CONCLUSIONS: We concluded that a feasible treatment modality to cure recalcitrant cutaneous warts is in combination of CO2 laser and imiquimod. Immunoenhancement plays an important role in the treatment of recalcitrant warts.

TLR-induced cytokines promote effective proinflammatory natural Th17 cell responses.

Naive CD4 lymphocytes undergo a polarization process in the periphery to become induced Th17 (iTh17) cells. Using retinoic acid-related orphan receptor γt (RORγt)-gfp mice, we found that RORγt and the transcription factor promyelocytic leukemia zinc finger (PLZF) are valuable new markers to identify the recently described natural Th17 (nTh17) cell population. nTh17 cells are thymically committed to promptly produce large amounts of IL-17 and IL-22. In this study, we show that, in addition to responding to TCR cross-linking, nTh17 cells secrete IL-17 and IL-22 when stimulated with IL-23 plus IL-1ß, either in recombinant form or in supernatants from TLR4-activated dendritic cells. This innate-like ability of RORγt(+) nTh17 cells to respond to TLR4-induced cytokines was not shared by iTh17 cells. The other distinct properties of RORγt(+) nTh17 cells are their high expression of PLZF and their absence from lamina propria; iTh17 cells are found therein. RORγt(+) nTh17 cells are present in the thymus of germ-free RORγt-gfp and IL-6(-/-) RORΓ: t-gfp mice, indicating that these cells do not require symbiotic microbiota or IL-6 for their generation. Finally, we found that PLZF(+)RORγt(+) nTh17 cells represent one of the primary IL-17-producing innate-like T cell populations in a TLR7 imiquimod model of psoriasis-like disorder, indicating their involvement in this kind of lesion. Collectively, our results reveal RORγt and PLZF as characteristic markers for identifying nTh17 cells and demonstrate one of their novel properties: the ability to respond promptly to TLR-dependent proinflammatory stimuli without TCR engagement, placing them as members of the innate-like T cell family.

Endogenous n-3 polyunsaturated fatty acids protect against imiquimod-induced psoriasis-like inflammation via the IL-17/IL-23 axis.

The beneficial effects of n-3 polyunsaturated fatty acids (PUFAs) on psoriasis have been reported in rats, mice and humans, but the specific mechanisms involved have not been well defined. The present study utilized the fat-1 mouse, a transgenic model that can endogenously convert n-6 FAs into n-3 PUFAs, to directly determine if the outcomes of psoriasis were correlated with n-3 PUFAs. Wild-type (WT) and fat-1 mice, which were treated daily with imiquimod (IMQ) cream or control cream on the shaved right ear and dorsal skin, were fed the same diet. The severity of inflammation of the ear and dorsal skin was scored according to the clinical Psoriasis Area and Severity Index (PASI) and epidermal hyperplasia was measured by H&E staining. The expression of inflammatory factors in the epidermis was analyzed by immunohistochemical analysis. Flow cytometry and an enzyme-linked immunosorbent assay were used to measure the differences in the content of inflammatory factors in the blood serum and to determine which of CD4+ T cells were present in the spleen between IMQ-induced fat-1 mice and WT mice. Fat-1 IMQ-induced mice exhibited significantly lower levels of inflammatory cell-like T helper 17 cells (Th17 cells) and higher levels of regulatory T cells (Treg cells) in the spleen as compared with the WT IMQ-induced mice. n-3 fatty acids stimulated Th17 cells to produce lower levels of inflammatory factors, including interleukin (IL)-17, IL-22, IL-23 and stimulated Treg cells to produce higher anti-inflammatory factors, such as Foxp3. In conclusion, the present study provides further insight into the mechanisms involved in preventing inflammation in psoriasis-like mice by n-3 PUFAs using a fat-1 transgenic mouse model.

Reactive oxygen species prevent imiquimod-induced psoriatic dermatitis through enhancing regulatory T cell function.

Psoriasis is a chronic inflammatory skin disease resulting from immune dysregulation. Regulatory T cells (Tregs) are important in the prevention of psoriasis. Traditionally, reactive oxygen species (ROS) are known to be implicated in the progression of inflammatory diseases, including psoriasis, but many recent studies suggested the protective role of ROS in immune-mediated diseases. In particular, severe cases of psoriasis vulgaris have been reported to be successfully treated by hyperbaric oxygen therapy (HBOT), which raises tissue level of ROS. Also it was reported that Treg function was closely associated with ROS level. However, it has been only investigated in lowered levels of ROS so far. Thus, in this study, to clarify the relationship between ROS level and Treg function, as well as their role in the pathogenesis of psoriasis, we investigated imiquimod-induced psoriatic dermatitis (PD) in association with Treg function both in elevated and lowered levels of ROS by using knockout mice, such as glutathione peroxidase-1(-/-) and neutrophil cytosolic factor-1(-/-) mice, as well as by using HBOT or chemicals, such as 2,3-dimethoxy-1,4-naphthoquinone and N-acetylcysteine. The results consistently showed Tregs were hyperfunctional in elevated levels of ROS, whereas hypofunctional in lowered levels of ROS. In addition, imiquimod-induced PD was attenuated in elevated levels of ROS, whereas aggravated in lowered levels of ROS. For the molecular mechanism that may link ROS level and Treg function, we investigated the expression of an immunoregulatory enzyme, indoleamine 2,3-dioxygenase (IDO) which is induced by ROS, in PD lesions. Taken together, it was implied that appropriately elevated levels of ROS might prevent psoriasis through enhancing IDO expression and Treg function.

A comparison of the effects of topical treatment of calcipotriol, camptothecin, clobetasol and tazarotene on an imiquimod-induced psoriasis-like mouse model.

The interleukin-23/interleukin 17A (IL-23/IL-17A) cytokine axis plays a critical role in the pathogenesis of psoriasis. In this study, we report the effects of topical calcipotriol, camptothecin, clobetasol and tazarotene on the treatment of imiquimod (IMQ)-induced psoriasis-like inflammation, the development of which is dependent on the IL-23/IL-17A axis. IMQ-induced epidermal hyperplasia and inflammation in the BALB/c mouse ear were significantly inhibited following clobetasol treatment but not calcipotriol, camptothecin or tazarotene treatments. Real-time polymerase chain reaction showed that the mRNA levels of IL-17A, IL-17F, IL-22, IL-1ß, IL-6 and TNF-α in ear skin were significantly decreased by clobetasol. In addition, we observed that calcipotriol, camptothecin and tazarotene failed to show any inhibitory effects on the IL-23/IL-17A/IL-22 axis. We also found that clobetasol treatment inhibited the proliferation of γδ T cells and C-C chemokine receptor type 6 (CCR6) expression induced by IMQ. Calcipotriol, camptothecin and tazarotene not only failed to inhibit this proliferation but also enhanced retinoic acid-related orphan receptor γ (RORγ) expression in IMQ-induced psoriasis-like inflammation. In conclusion, we suggest that clobetasol induces the relief of IMQ-induced psoriasis-like inflammation in a mouse model but that calcipotriol, camptothecin and tazarotene cannot. Therefore, we suggest that more in-depth studies on pharmacological effects of tazarotene, camptothecin and calcipotriol should be carried out.

Humanized mouse model of glucose 6-phosphate dehydrogenase deficiency for in vivo assessment of hemolytic toxicity.

Individuals with glucose 6-phosphate dehydrogenase (G6PD) deficiency are at risk for the development of hemolytic anemia when given 8-aminoquinolines (8-AQs), an important class of antimalarial/antiinfective therapeutics. However, there is no suitable animal model that can predict the clinical hemolytic potential of drugs. We developed and validated a human (hu)RBC-SCID mouse model by giving nonobese diabetic/SCID mice daily transfusions of huRBCs from G6PD-deficient donors. Treatment of SCID mice engrafted with G6PD-deficient huRBCs with primaquine, an 8-AQ, resulted in a dose-dependent selective loss of huRBCs. To validate the specificity of this model, we tested known nonhemolytic antimalarial drugs: mefloquine, chloroquine, doxycycline, and pyrimethamine. No significant loss of G6PD-deficient huRBCs was observed. Treatment with drugs known to cause hemolytic toxicity (pamaquine, sitamaquine, tafenoquine, and dapsone) resulted in loss of G6PD-deficient huRBCs comparable to primaquine. This mouse model provides an important tool to test drugs for their potential to cause hemolytic toxicity in G6PD-deficient populations.

[Expression of NLRP3 inflammasome in BALB/c mice with imiquimod-induced psoriasis-like inflammation and therapeutic effect of mustard seed (Sinapis Alba Linn)].

OBJECTIVE: To investigate the role of NLRP3 inflammasome in imiquimod-induced psoriasis-like inflammation in mice and the therapeutic effects of mustard seed (Sinapis Alba Linn). METHODS: Thirty BALB/c mice were randomized equally into blank control group (fed with normal forage and treated with vehicle), model group (fed with normal forage and treated with 5% imiquimod cream), and experimental group (fed with 5% mustard seed forage and treated with 5% imiquimod cream). RT-PCR was used to detect the mRNA expression of NLRP3, ASC, caspase-1, and caspase-11. Immunohistochemistry was performed to determine the expression and distribution of ASC and caspase-1. ELISA was used to test the serum levels of interleukin-1ß (IL-1ß) and IL-18. RESULTS: Compared with the blank control group, the mice with imiquimod-induced psoriasis-like inflammation showed significantly increased NLRP3, ASC, caspase-1, and caspase-11 mRNA expressions, ASC and caspase-1 protein expressions , and serum levels of IL-1ß and IL-18 (P<0.05). These changes were obviously attenuated by feeding the mice with mustard seed. CONCLUSION: NLRP3 inflammasome is involved in imiquimod-induced psoriasis-like inflammation in mice, and mustard seed may suppress the inflammation induced by IL-1ß and IL-18 through down-regulating the expression of NLRP3 inflammasome.