Skin-penetrating methotrexate alleviates imiquimod-induced psoriasiform dermatitis via decreasing IL-17-producing gamma delta T cells

The Anti-Psoriatic Efficacy and Safety Profile of Topical and Intralesional Methotrexate: A Literature Review

Methotrexate (MTX) has long been considered the first-line oral systemic pharmacotherapy for psoriasis. The drug has several well-known systemic side effects, such as bone marrow suppression and hepatotoxicity. To avoid them, the use of topical or intralesional administrations of MTX has become an interesting option. With the advent of novel drug delivery systems, especially nanocarriers, the usage of a high-efficacy and safe topical MTX for psoriasis has nearly been attained. This review examined the development, anti-psoriatic efficacy and adverse effects of topical forms of MTX (plain MTX; MTX with chemical enhancer; MTX using nanotechnology; MTX with protein transduction domains; MTX with liquid crystalline systems; and MTX with physical enhancer/laser) and intralesional MTX in psoriasis patients and psoriasis-induced animals. The efficacy of topical MTX varied with the drug delivery technology employed. Nevertheless, the overall safety profile of the topical forms was favourable. A 25 mg/mL MTX solution injected intralesionally at the nail matrix worked well for nail psoriasis recalcitrant to topical treatment. To improve the standard of care for patients with psoriasis, randomized controlled trials that establish the most effective MTX-delivery system are needed.

Potential effects and mechanisms of Chinese herbal medicine in the treatment of psoriasis

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is a chronic inflammatory dermatosis related to high morbidity and mortality. The incidence of psoriasis is increasing in recent decades. Some patients with psoriasis are anxious about the underlying side effects of synthetic drugs they are on. Therefore, they are eager to seek alternative and efficient therapy, such as Chinese herbal medicine (CHM). Researchers have found some CHM provides best source for the development of anti-psoriatic drugs because of their structural diversity and fewer adverse reactions. Some of CHM formulas or active constituents extracted from CHM have been rapidly developed into clinical drugs with good efficacy. At present, along with the CHM formulas, single CHM and its active components have been extensively accepted and utilized in the treatment of psoriasis, whose therapeutic mechanisms hitherto have not been thoroughly illustrated.

AIM OF THE STUDY

This review aimed to comprehensively summarize about the existing therapeutic mechanisms of CHM in the treatment of psoriasis and to provide a reference to develop future related studies in this field.

MATERIALS AND METHODS

Relevant literatures about how CHM treated psoriasis were acquired from published scientific studies (including PubMed, CNKI, Web of Science, Baidu Scholar, The Plant List, Elsevier and SciFinder). All plants appearing in the review have been included in The Plant List or Medicinal Plant Names Services (MPNS).

RESULTS

In this review, we collect numerous literatures about how CHM treats psoriasis via immune cells, signaling pathways and disease-related mediators and systematically elucidates potential mechanisms from the point of the suppression of oxidative stress, the inhibition of abnormal abnormal proliferation and differentiation, the inhibition of immune responses, and the suppression of angiogenesis.

CONCLUSIONS

Psoriasis is considered as a complicated disease caused by interaction among various mechanisms. The CHM formulas, single CHM and its active components have considerable positive reports about the treatment of psoriasis, which brings hope for a promising future of CHM in the clinical therapy of psoriasis. In the paper, we have concluded that the existing therapeutic mechanisms of CHM in the treatment of psoriasis.

Identification of phosphodiesterase-4 as the therapeutic target of arctigenin in alleviating psoriatic skin inflammation

Introduction

Arctigenin, derived from Arctium lappa L., has multiple pharmacological activities, including immunoregulatory, anti-diabetic, anti-tumor, and neuroprotective effects. Nevertheless, the potential therapeutic target of arctigenin in modulating inflammation remains undefined.

Objectives

In the present study, we identified that arctigenin was a phosphodiesterase-4 (PDE4) selective inhibitor for the first time. Further investigations were performed to fully uncover the effects and mechanism of arctigenin on experimental murine psoriasis model.

Methods

Crystal structure determination, PDEs enzyme assay, and isothermal titration calorimetry were included to illustrate the binding specialty, inhibitory effects, and selectivity of arctigenin on PDE4D. The anti-inflammatory effects were conducted in LPS-activated human peripheral blood mononuclear cells (PBMCs) and RAW264.7 cells. Imiquimod-induced murine psoriasis was performed to uncover the therapeutic effects and mechanism of arctigenin in vivo.

Results

Arctigenin could bind to the catalytic domain of PDE4D via formation of hydrogen bonds as well as π-π stacking interactions between the dibenzyl butyrolactone of arctigenin and several residues of PDE4D. Accordingly, arctigenin showed prominent anti-inflammation in human PBMCs and murine RAW264.7 cells. PDE4 inhibition by arctigenin resulted in elevation of intracellular cyclic adenosine monophosphate (cAMP) and phosphorylation of cAMP-response element binding protein (CREB), which were largely blocked through intervention of protein kinase A (PKA) activity by H89 treatment or reduction of protein expression by siRNA transfection. Moreover, we first identified that a topical application of arctigenin ameliorated experimental psoriatic manifestations in imiquimod-induced murine psoriasis model by decreasing adhesion and chemotaxis of several inflammatory cells. Further proteomics analysis revealed that arctigenin could rectify the immune dysfunction and hyperactivation of keratinocytes in the inflamed skin microenvironments, which might be largely related to the expression of Keratins.

Conclusion

The research provided credible clew that inhibition of PDE4 by arctigenin might function as the potential therapeutic approach for the treatment of psoriasis.

Skin atrophy caused by topical glucocorticoids is less common in patients with atopic dermatitis than in those with psoriasis

Although the long-term use of topical glucocorticoids (TGC) may induce skin atrophy including striae distensae (SD), patients with atopic dermatitis (AD) appear to have lesser degree of skin atrophy than those with psoriasis (PSO). Periostin, encoded by POSTN, is involved in tissue remodelling processes of chronic AD lesions. This study was designed to investigate the difference in the occurrence of skin atrophy in patients with AD or PSO when treated with TGC and to elucidate the association between skin atrophy and periostin. Big data analysis using Korean Health Claims Database was performed to determine the prevalence of SD in AD and PSO patients. Blood and skin eosinophils count and dermal fibrosis between AD and PSO patients were compared, and immunohistochemistry for periostin and mRNA sequencing in the dermis were performed. Animal experiments using AD and PSO murine model were conducted. Big data analysis revealed that patients with AD have significantly lesser degree of SD than patients with PSO. The ratio of the dermal fibrous tissues and eosinophil counts were significantly higher in AD patients. In AD skin, periostin was more widely distributed in the entire dermis and POSTN mRNAs were significantly upregulated. Dermal thickness and fibrosis were significantly higher in AD mice even after TGC treatment. A significant positive correlation was observed between dermal fibrosis and tissue eosinophil counts. Lesser skin atrophy in AD patients even after long-term TGC application could be resulted from skin fibrosis caused by increased tissue eosinophils and periostin deposition.

Gamma Delta T Cells and Their Pathogenic Role in Psoriasis

γδT cells are an unconventional population of T lymphocytes that play an indispensable role in host defense, immune surveillance, and homeostasis of the immune system. They display unique developmental, distributional, and functional patterns and rapidly respond to various insults and contribute to diverse diseases. Although γδT cells make up only a small portion of the total T cell pool, emerging evidence suggest that aberrantly activated γδT cells may play a role in the pathogenesis of psoriasis. Dermal γδT cells are the major IL-17-producing cells in the skin that respond to IL-23 stimulation. Furthermore, γδT cells exhibit memory-cell-like characteristics that mediate repeated episodes of psoriatic inflammation. This review discusses the differentiation, development, distribution, and biological function of γδT cells and the mechanisms by which they contribute to psoriasis. Potential therapeutic approaches targeting these cells in psoriasis have also been detailed.

Topical methotrexate in dermatology: a review of the literature

Background: Systemic methotrexate (MTX) is a useful treatment for many dermatologic conditions, however, the risk of adverse events prevents its use in patients with minimal or localized disease. Topical application of MTX may be an option to avoid the systemic adverse effects of oral MTX.Objective: To assess what is known about the efficacy and safety of topical methotrexate.Methods: A search on Pubmed was conducted. There were no limits on publication date.Results: A total of 963 articles were discovered. Using our exclusion criteria, 916 articles were excluded; 47 articles were used for full text assessment. Topical MTX has been used primarily in psoriasis but also in mycosis fungoides, lymphomatoid papulosis, and oral precancerous lesions. Optimal delivery system and formulation for adequate penetration is still under investigation.Conclusion: The quality of evidence for the utility of topical methotrexate in psoriasis is good, however, for other dermatologic diseases, the quality is poor. Topical MTX with improved delivery methods may be a viable tool against certain localized dermatologic conditions for patients who do not tolerate oral MTX. Further double-blinded randomized controled studies are needed to substantiate the utility of topical methotrexate.

Development, characterization and evaluation of topical methotrexate-entrapped deformable liposome on imiquimod-induced psoriasis in a mouse model

The aim of this study was to prepare and characterize topical methotrexate (MTX) with different percentages (0.05%, 0.1%, 0.25% and 0.5%) entrapped in deformable liposomes using phosphatidylcholine and oleic acid. The effectiveness and sub-acute toxicity of these topical formulations were investigated in imiquimod (IMQ)-induced psoriasis in a mouse model (IMQP). The particle sizes of formulations were around 100 nm with a mean zeta potential of -72.87 mV. The entrapment efficiency (EE%) of MTX in liposomal formulations were more than 85%. Franz cell permeability studies indicated that permeation of MTX through the healthy BALB/c mice skin is very low; however, in the inflammatory skin, which was induced by IMQ it was significant (50%). Liposomal MTX (LM 0.05 and 0.1%) caused significant reduction of thickness score dose-dependently in IMQP compared to the injected MTX. Moreover, investigation of the inflammatory factor and pathological examinations of skin proved the superiority of the LM treating group. Pathological examinations also showed there are no toxicity in organs of the mice that received the LM. Blood cell count test didn't show any abnormality. MTX-entrapped deformable liposomes could be a topical option in future for the treatment of human psoriasis with a less toxicity and merit further investigations.

Resident and monocyte-derived Langerhans cells are required for imiquimod-induced psoriasis-like dermatitis model

BACKGROUND

Langerhans cells (LCs) are dendritic cells that reside in the epidermis and local inflammation results in an increased differentiation of monocyte-derived LCs. Only few studies have investigated on the role of LCs in psoriasis-like dermatitis model, but the results are variable and the exact role of LCs in psoriasis model remains to be elucidated.

OBJECTIVE

To explore the functional role of resident (rLCs) and monocyte-derived LCs (mLCs) in imiquimod (IMQ)-induced psoriasis-like inflammation using human Langerin-diphtheria toxin subunit A (huLang-DTA) mice.

METHODS

5% IMQ cream was topically applied on the skins. Clinical and histopathological features were evaluated. Psoriasis-related gene expression was analyzed by quantitative polymerase chain reaction. The production of psoriasis-related cytokines including IL-17A and IL-22 by T cells were assessed by flow cytometry from the lesional skins.

RESULTS

huLang-DTA mice showed a common depletion of both rLCs and mLCs in the IMQ-treated skins. huLang-DTA mice had a reduced IMQ-induced psoriasis-like inflammation featuring erythema, scale, and thickness compared with wild-type mice. Psoriatic lesions from huLang-DTA mice had a decreased level of Il23a and accordingly demonstrated an attenuated cytokine production of IL-17A and IL-22 from γδ^low T cells. mLCs revealed a significantly greater level of IL-23 expression compared to rLCs in response to topical IMQ treatment.

CONCLUSION

Although both rLCs and mLCs are involved in the development of IMQ-induced psoriasis-like dermatitis, inflammation-induced mLCs present a superior capacity for producing IL-23 in this murine experimental model of psoriasis.

In vivo anti-psoriatic activity, biodistribution, sub-acute and sub-chronic toxicity studies of orally administered methotrexate loaded chitin nanogel in comparison with methotrexate tablet

The anti-psoriatic efficacy of orally administered methotrexate loaded chitin nanogel (MCNG) was evaluated (two doses- 2.715 mg/kg and 5.143 mg/kg) and compared against orally administered methotrexate tablet MTX (5.143 mg/kg). MCNG at both dose levels of 2.715 mg/kg and 5.143 mg/kg exhibited significant anti-psoriatic activity which is very much comparable with MTX, caused normalization of histological features and inflammatory score associated with induced psoriasis. Biodistribution studies revealed the presence of drug in serum and in vital organs at all the three cases with highest amount in MCNG at 5.143 mg/kg dose, followed by MTX tablet and are lowest in MCNG at 2.715 mg/kg dose. MCNG at the highest dose of 5.143 mg/kg caused liver, lung and kidney toxicities on sub acute toxicity studies and MTX tablet was found to be toxic on liver and lung on sub chronic toxicity studies. MCNG 2.715 mg/kg was found to be safe on both sub acute and sub chronic administrations, suggesting that it can provide sufficient serum and tissue level of methotrexate necessary to clear psoriatic lesions, without inducing systemic toxicity and expected to be a better alternative for orally administered conventional methotrexate tablet for patients who need systemic medications for psoriasis.

Antipsoriatic Effects of Wannachawee Recipe on Imiquimod-Induced Psoriasis-Like Dermatitis in BALB/c Mice

Psoriasis is a common immune-mediated chronic inflammatory skin disease characterized by thick and erythema raised plaques with adherent silvery scales. T-cells are activated via the IL-23/Th17 axis which is involved in psoriasis pathogenesis. Conventional treatments of psoriasis have adverse events that influence patients' adherence. Wannachawee Recipe (WCR) is Thai traditional medicine that is known to be effective for psoriasis patients; however, preclinical evidence is still lacking. This study investigated the therapeutic potential of WCR on antiproliferant activity using imiquimod- (IMQ-) induced psoriasis-like dermatitis in a mouse model. Psoriasis-like dermatitis was induced on the shaved dorsal skin and right ear pinna of BALB/c mice by topical application of IMQ for 15 consecutive days after which WCR was administered to the mice by oral gavage for 10 days. Phenotypical observations, histopathological examinations, and ELISA of skin and blood samples were conducted. WCR significantly ameliorated development of IMQ-induced psoriasis-like dermatitis and reduced levels of Th17 cytokines (IL-17A, IL-22, and IL-23) in both serum and dorsal skin. Histopathological findings showed a decrease in epidermal thickness and inflammatory T-cell infiltration in the WCR-treated groups. The WCR has pharmacological actions which regulate Th17 related cytokines suggesting that it is a potential alternative therapeutic strategy for psoriasis.

Interleukin-21 receptor signalling is not critically required for imiquimod-induced psoriasiform dermatitis in mice

Psoriasis is largely mediated by interleukin (IL)-23/T helper (Th) 17 axis, and IL-21 is a pleiotropic cytokine expressed by Th17 cells. Despite previously reported possible pathogenic roles of IL-21 in human psoriasis, we found that IL-21 receptor (IL-21R) signalling was not crucial for imiquimod-induced psoriatic inflammation, using IL-21R^-/- mice. The severity of imiquimod-induced psoriatic manifestation and pro-inflammatory Th17 cytokine levels, IL-17A-producing γδ T cells and CD4+ T cells, and in vitro IL-17A production by γδ T cells after IL-23 stimulation was comparable between wild-type and IL-21R^-/- mice. Collectively, IL-21R signalling was not critically involved in IMQ-induced psoriatic inflammation despite an increased IL-21 expression in the IMQ-treated mouse skin. Our data may represent the significant differences between human psoriasis and murine psoriasis model, and further studies using other models will be required to elucidate the role of IL-21 in psoriasis pathogenesis.

The Origin of Skin Dendritic Cell Network and Its Role in Psoriasis

Dendritic cells (DCs) are heterogeneous groups of innate immune cells, which orchestrate immune responses by presenting antigens to cognate T cells and stimulating other types of immune cells. Although the term ‘DCs’ generally represent highly mixed subsets with functional heterogeneity, the classical definition of DCs usually denotes conventional DCs (cDCs). Skin contains a unique DC network mainly composed of embryo precursor-derived epidermal Langerhans cells (LCs) and bone marrow-derived dermal cDCs, which can be further classified into type 1 (cDC1) and type 2 (cDC2) subsets. Psoriasis is a chronic inflammatory skin disease, which is principally mediated by IL-23/IL-17 cytokine axis. In the psoriatic skins, DCs are prominent cellular sources for TNF-α and IL-23, and the use of blocking antibodies against TNF-α and IL-23 leads to a significant clinical improvement in psoriatic patients. Recent elegant human and mouse studies have shown that inflammation-induced inflammatory DCs, LCs, dermal cDC2, and monocyte-derived DCs are pivotal DC subsets in psoriatic inflammation. Thus, targeting specific pathogenic DC subsets would be a potential strategy for alleviating and preventing DC-derived IL-23-dependent psoriatic inflammation and other inflammatory dermatoses in the future.

Topical administration of reversible SAHH inhibitor ameliorates imiquimod-induced psoriasis-like skin lesions in mice via suppression of TNF-α/IFN-γ-induced inflammatory response in keratinocytes and T cell-derived IL-17

DZ2002, a reversible S-adenosyl-l-homocysteine hydrolase (SAHH) inhibitor with immunosuppressive properties and potent therapeutic activity against various autoimmune diseases in mice. The present study was designed to characterize the potential therapeutic effects of DZ2002 on murine model of psoriasis and reveal the correlated mechanisms. In this report, we demonstrated that in vitro, DZ2002 significantly decreased the expression of pro-inflammatory cytokines and adhesion molecule including IL-1α, IL-1β, IL-6, IL-8, TNF-α and ICAM-1 by inhibiting the phosphorylation of p38 MAPK, ERK and JNK in TNF-α/IFN-γ-stimulated HaCaT human keratinocytes. Topical administration of DZ2002 alleviated the imiquimod (IMQ)-induced psoriasis-like skin lesions and inflammation in mice, the therapeutic effect was comparable with the Calcipotriol. Moreover, the inflammatory skin disorder was restored by DZ2002 treatment characterized by reducing both of the CD3⁺ T cell accumulation and the psoriasis-specific cytokines expression. Further, we found that DZ2002 improved IMQ-induced splenomegaly and decreased the frequency of splenic IL-17-producing T cells. Our finding offered the convincing evidence that SAHH inhibitor DZ2002 might attenuate psoriasis by simultaneously interfering the abnormal activation and differentiation of keratinocytes and accumulation of IL-17-producing T cells in skin lesions.

Anti-psoriatic and toxicity evaluation of methotrexate loaded chitin nanogel in imiquimod induced mice model

Methotrexate loaded chitin nanogel (MCNG) was formulated for its topical use in psoriasis. MCNG was characterized by DLS, TEM and FTIR. The MCNG particles were spherical in shape with size of 196±14nm, having surface charge of +9.21±0.42 mv. MCNG exhibited greater swelling and drug release at acidic pH than neutral and alkaline conditions. The treatment with MCNG showed significant level of toxicity on HaCaT and THP-1 cells and was taken up well by HaCaT cells as revealed by fluorescent microscopy. MCNGs exhibited significant anti-inflammatory activity as revealed by the inhibitory effects observed on the activity of COX-2 and LOX-5 enzymes expressed in THP-1 cells. Skin permeation studies revealed an increased trasdermal flux of methotrexate from MCNG with loosened stratum corneum and other epidermal layers of skin in comparison with control methotrexate solution treated samples. Significant anti-psoriatic efficacy on imiquimod (IMQ) induced model of psoriasis without any dermal and systemic toxicities suggest that it as an ideal delivery platform for topical delivery of methotrexate in psoriasis. Thus it is expected to become a better alternative for the oral delivery of methotrexate in the selected disease.

Inhibitory Effect of Imiquimod-Induced Psoriasis-Like Skin Inflammation in Mice by Histamine H4 Receptor Agonist 4-Methylhistamine

Psoriasis is a chronic inflammatory immune-mediated autoimmune skin disorder. The histamine H4 receptor (H4R) agonist 4-methylhistamine (4-MH) plays an important role in immunomodulation of inflammatory responses associated with allergic inflammatory diseases. In this study, we investigated the effects of H4R agonist 4-MH on the development of imiquimod (IMQ)-induced psoriasis-like skin inflammation in mice and explored the immunoregulatory mechanism involved. The total clinical severity scores were significantly ameliorated by treatment with 4-MH (20 mg/kg) and 4-MH (40 mg/kg). Histological analysis of the skin revealed that 4-MH (20 mg/kg) and 4-MH (40 mg/kg) significantly attenuated the psoriatic phenotypes, including epidermal hyperplasis, hyperkeratosis and lymphocytes infiltration. Treatment with 4-MH (20 mg/kg) and 4-MH (40 mg/kg) led to reductions in the levels of Th1 cytokines (TNF-α, IFN-α, and IL-27) in the serum and dorsal skin, whereas Th17 cytokines levels (IL-17A and IL-23) did not change in response to treatment with 4-MH (20 mg/kg) and 4-MH (40 mg/kg). Furthermore, the number of CD4(+) CD25(+) FoxP3(+) regulatory T (Treg) cells was significantly increased by treatment with 4-MH (40 mg/kg). Taken together, these results imply that H4R agonist 4-MH might be an effective immunomodulatory approach for treatment of patients with psoriasis and the effects may be related to inhibited epidermal alteration, selectively reduced Th1 pro-inflammatory cytokines, and recruited CD4(+) CD25(+) FoxP3(+) Treg cells.

Targeting adenosine receptors to prevent inflammatory skin diseases

Adenosine mediates its effects through activation of a family of four G-protein-coupled receptors, named A1 , A2A , A2B and A3 . This nucleoside plays an important role in immunity and inflammation, and the A2A adenosine receptor subtype has a key role in the inhibition of inflammatory processes besides promoting wound healing. In this issue of Experimental Dermatology, Arasa et al. show that the topical application of a selective A2A agonist, CGS 21680, to mouse skin reduced epidermal hyperplasia as well as skin inflammation, similarly to topical corticoids, without side effects like skin atrophy. Rigorously following up this work is important for the development of novel treatment strategies for chronic hyperproliferative inflammatory dermatoses, such as targeting the A2A adenosine receptor family.

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.

Dermal-resident versus recruited γδ T cell response to cutaneous vaccinia virus infection

The study of T cell immunity at barrier surfaces has largely focused on T cells bearing the αβ TCR. However, T cells that express the γδ TCR are disproportionately represented in peripheral tissues of mice and humans, suggesting they too may play an important role responding to external stimuli. In this article, we report that, in a murine model of cutaneous infection with vaccinia virus, dermal γδ T cell numbers increased 10-fold in the infected ear and resulted in a novel γδ T cell population not found in naive skin. Circulating γδ T cells were specifically recruited to the site of inflammation and differentially contributed to dermal populations based on their CD27 expression. Recruited γδ T cells, the majority of which were CD27(+), were granzyme B(+) and made up about half of the dermal population at the peak of the response. In contrast, recruited and resident γδ T cell populations that made IL-17 were CD27(-). Using a double-chimera model that can discriminate between the resident dermal and recruited γδ T cell populations, we demonstrated their divergent functions and contributions to early stages of tissue inflammation. Specifically, the loss of the perinatal thymus-derived resident dermal population resulted in decreased cellularity and collateral damage in the tissue during viral infection. These findings have important implications for our understanding of immune coordination at barrier surfaces and the contribution of innate-like lymphocytes on the front lines of immune defense.

Nanomiemgel--a novel drug delivery system for topical application--in vitro and in vivo evaluation

Aim

The objective of this study was to formulate and evaluate a unique matrix mixture (nanomiemgel) of nanomicelle and nanoemulsion containing aceclofenac and capsaicin using in vitro and in vivo analyses and to compare it to a marketed formulation (Aceproxyvon).

Methods

Nanomicelles were prepared using Vitamin E TPGS by solvent evaporation method and nanoemulsion was prepared by high-pressure homogenization method. In vitro drug release and human skin permeation studies were performed and analyzed using HPLC. The efficiency of nanomiemgel as a delivery system was investigated using an imiquimod-induced psoriatic like plaque model developed in C57BL/6 mice.

Results

Atomic Force Microscopy images of the samples exhibited a globular morphology with an average diameter of 200, 250 and 220 nm for NMI, NEM and NMG, respectively. Nanomiemgel demonstrated a controlled release drug pattern and induced 2.02 and 1.97-fold more permeation of aceclofenac and capsaicin, respectively than Aceproxyvon through dermatomed human skin. Nanomiemgel also showed 2.94 and 2.09-fold greater Cmax of aceclofenac and capsaicin, respectively than Aceproxyvon in skin microdialysis study in rats. The PASI score, ear thickness and spleen weight of the imiquimod-induced psoriatic-like plaque model were significantly (p<0.05) reduced in NMG treated mice compared to free drug, NEM, NMI & Aceproxyvon.

Conclusion

Using a new combination of two different drug delivery systems (NEM+NMI), the absorption of the combined system (NMG) was found to be better than either of the individual drug delivery systems due to the utilization of the maximum possible paths of absorption available for that particular drug.

Inhibition of autoimmune Chagas-like heart disease by bone marrow transplantation

BACKGROUND

Infection with the protozoan Trypanosoma cruzi manifests in mammals as Chagas heart disease. The treatment available for chagasic cardiomyopathy is unsatisfactory.

METHODS/PRINCIPAL FINDINGS

To study the disease pathology and its inhibition, we employed a syngeneic chicken model refractory to T. cruzi in which chickens hatched from T. cruzi inoculated eggs retained parasite kDNA (1.4 kb) minicircles. Southern blotting with EcoRI genomic DNA digests revealed main 18 and 20 kb bands by hybridization with a radiolabeled minicircle sequence. Breeding these chickens generated kDNA-mutated F1, F2, and F3 progeny. A targeted-primer TAIL-PCR (tpTAIL-PCR) technique was employed to detect the kDNA integrations. Histocompatible reporter heart grafts were used to detect ongoing inflammatory cardiomyopathy in kDNA-mutated chickens. Fluorochromes were used to label bone marrow CD3+, CD28+, and CD45+ precursors of the thymus-dependent CD8α+ and CD8β+ effector cells that expressed TCRγδ, vβ1 and vβ2 receptors, which infiltrated the adult hearts and the reporter heart grafts.

CONCLUSIONS/SIGNIFICANCE

Genome modifications in kDNA-mutated chickens can be associated with disruption of immune tolerance to compatible heart grafts and with rejection of the adult host's heart and reporter graft, as well as tissue destruction by effector lymphocytes. Autoimmune heart rejection was largely observed in chickens with kDNA mutations in retrotransposons and in coding genes with roles in cell structure, metabolism, growth, and differentiation. Moreover, killing the sick kDNA-mutated bone marrow cells with cytostatic and anti-folate drugs and transplanting healthy marrow cells inhibited heart rejection. We report here for the first time that healthy bone marrow cells inhibited heart pathology in kDNA+ chickens and thus prevented the genetically driven clinical manifestations of the disease.