RNA sequencing and metabolic analysis of imiquimod-induced psoriasis-like mice with chronic restrain stress.

AIM: Psoriasis is one of the most common dermatological disorders, characterized by increased epidermal hyperplasia and immune cell infiltration. Psychological stress has been reported to contribute to the severity, aggravation, and relapse of psoriasis. However, the exact mechanism involved in psychological stress's impact on psoriasis is still unclear. We aim to investigate the role of psychological stress in psoriasis from a transcriptomic and metabolomic perspective. MAIN METHOD: We developed a chronic restrain stress (CRS)-imiquimod (IMQ)-induced psoriasis-like mouse model and performed a comprehensive comparative transcriptomic and metabolic analysis with control mice, CRS-treated mice, and IMQ-treated mice to investigate how psychological stress affects psoriasis. KEY FINDING: We found that CRS-IMQ-induced psoriasis-like mice showed significant exacerbation of psoriasis-like skin inflammation compared with mice treated with IMQ only. Mice of the CRS + IMQ group showed increased expression of keratinocyte proliferation and differentiation genes, differential regulation of cytokines, and promotion of linoleic acid metabolism. Correlation analysis of differentially expressed genes in the CRS-IMQ-induced psoriasis-like mice and human psoriasis datasets compared with respective controls revealed 96 overlapping genes of which 30 genes showed consistent induced or repressed expression in all human and mouse datasets. SIGNIFICANCE: Our study provides new insights into the effects of psychological stress on psoriasis pathogenesis and the mechanisms involved, which provides clues for development of therapeutics or biomarkers.

Oral exposure to citrinin significantly exacerbates the pathophysiology of a mouse model of imiquimod-induced psoriasis via direct activation of dendritic cell.

Citrinin, a mycotoxin produced by Penicillium citrinum and Penicillium verrucosum, mainly contaminates cereals. The aim of study was to investigate the novel immunoreactive effect of citrinin using a mouse model of psoriasis. A mouse model of psoriasis was generated by topical application of 5% imiquimod in female BALB/c mice. Standard rodent diet and rice samples with 3 ppm of citrinin were mixed to obtain a final citrinin concentration of 0.3 ppm, and a citrinin-contaminated diet was fed to mice daily. Skin thickness, scratching behavior, and trans epidermal water loss (TEWL) were monitored continuously during the imiquimod application. Immediately after the final imiquimod application, ear skin and auricular lymph node (LN) were sampled for further analysis. Only a slight increase was observed in skin thickness in the citrinin exposure group; however, citrinin exposure significantly exacerbated hyperkeratinization and inflammatory cell infiltration in histological evaluation. TEWL, which is representative of cutaneous barrier function, was significantly increased by citrinin exposure. In terms of immune function, the number of immune cells in LN (T cells and dendritic cells) and gene expression of interleukin (IL)-17 in skin tissue were significantly increased by citrinin exposure. Direct interaction of dendritic cells (DCs) in citrinin-induced psoriasis development was further examined by proinflammatory cytokine determination in THP-1 cells and murine bone marrow derived DCs. IL-6 and/or tumor necrosis factor α were significantly increased by citrinin exposure. Taken together, our results imply that oral exposure to citrinin exacerbates the symptoms of a mouse model of psoriasis via direct activation of DCs.

Mechanisms of 8-aminoquinoline induced haemolytic toxicity in a G6PDd humanized mouse model.

Primaquine (PQ) and Tafenoquine (TQ) are clinically important 8-aminoquinolines (8-AQ) used for radical cure treatment of P. vivax infection, known to target hepatic hypnozoites. 8-AQs can trigger haemolytic anaemia in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDd), yet the mechanisms of haemolytic toxicity remain unknown. To address this issue, we used a humanized mouse model known to predict haemolytic toxicity responses in G6PDd human red blood cells (huRBCs). To evaluate the markers of eryptosis, huRBCs were isolated from mice 24-48 h post-treatment and analysed for effects on phosphatidylserine (PS), intracellular reactive oxygen species (ROS) and autofluorescence. Urinalysis was performed to evaluate the occurrence of intravascular and extravascular haemolysis. Spleen and liver tissue harvested at 24 h and 5-7 days post-treatment were stained for the presence of CD169+ macrophages, F4/80+ macrophages, Ter119+ mouse RBCs, glycophorin A+ huRBCs and murine reticulocytes (muRetics). G6PDd-huRBCs from PQ/TQ treated mice showed increased markers for eryptosis as early as 24 h post-treatment. This coincided with an early rise in levels of muRetics. Urinalysis revealed concurrent intravascular and extravascular haemolysis in response to PQ/TQ. Splenic CD169+ macrophages, present in all groups at day 1 post-dosing were eliminated by days 5-7 in PQ/TQ treated mice only, while liver F4/80 macrophages and iron deposits increased. Collectively, our data suggest 8-AQ treated G6PDd-huRBCs have early physiological responses to treatment, including increased markers for eryptosis indicative of oxidative stress, resulting in extramedullary haematopoiesis and loss of splenic CD169+ macrophages, prompting the liver to act as the primary site of clearance.

Discovery and Biological Evaluation of a Novel Highly Potent Selective Butyrylcholinsterase Inhibitor.

To discover novel BChE inhibitors, a hierarchical virtual screening protocol followed by biochemical evaluation was applied. The most potent compound 8012-9656 (eqBChE IC50 = 0.18 ± 0.03 µM, hBChE IC50 = 0.32 ± 0.07 µM) was purchased and synthesized. It inhibited BChE in a noncompetitive manner and could occupy the binding pocket forming diverse interactions with the target. 8012-9656 was proven to be safe in vivo and in vitro and showed comparable performance in ameliorating the scopolamine-induced cognition impairment to tacrine. Additionally, treatment with 8012-9656 could almost entirely recover the Aß1-42 (icv)-impaired cognitive function to the normal level and showed better behavioral performance than donepezil. The evaluation of the Aß1-42 total amount confirmed its anti-amyloidogenic profile. Moreover, 8012-9656 possessed blood-brain barrier (BBB) penetrating ability, a long T1/2, and low intrinsic clearance. Hence, the novel potential BChE inhibitor 8012-9656 can be considered as a promising lead compound for further investigation of anti-AD agents.

TLR7 agonist modulation of postasphyxial neurophysiological and cardiovascular adaptations in preterm fetal sheep.

Activation of Toll-like receptors (TLRs) after hypoxic-ischemic brain injury can exacerbate injury but also alleviate cell loss, as recently demonstrated with the TLR7 agonist Gardiquimod (GDQ). However, TLR agonists also modulate vascular function and neuronal excitability. Thus, we examined the effects of TLR7 activation with GDQ on cardiovascular function and seizures after asphyxia in preterm fetal sheep at 0.7 gestation (104 days, term ∼147 days). Fetuses received sham asphyxia or asphyxia induced by umbilical cord occlusion for 25 min or asphyxia followed by a continuous intracerebroventricular infusion of 3.34 mg of GDQ from 1 to 4 h after asphyxia. Fetuses were monitored continuously for 72 h postasphyxia. GDQ treatment was associated with sustained, moderate hypertension for 72 h (P < 0.05), with a transient increase in heart rate. Electroencephalographic (EEG) power was suppressed for the entire postasphyxial period in both groups, whereas EEG spectral edge transiently increased during the GDQ infusion compared with asphyxia alone (P < 0.05), with higher ß- and lower δ-EEG frequencies (P < 0.05). This increase in EEG frequency was not related to epileptiform activity. After the GDQ infusion, there was earlier onset of high-amplitude stereotypic evolving seizures, with increased numbers of seizures and seizure burden (P < 0.05). Hemodynamic function and seizure activity are important indices of preterm wellbeing. These data highlight the importance of physiological monitoring during preclinical testing of potential neuroprotective strategies.

Detrimental Effects of an Inhaled Phosphodiesterase-4 Inhibitor on Lung Inflammation in Ventilated Preterm Lambs Exposed to Chorioamnionitis Are Dose Dependent.

Background: Treatment of bronchopulmonary dysplasia in preterm infants is challenging due to its multifactorial origin. In rodent models of neonatal lung injury, selective inhibition of phosphodiesterase 4 (PDE4) has been shown to exert anti-inflammatory properties in the lung. We hypothesized that GSK256066, a highly selective, inhalable PDE4 inhibitor, would have beneficial effects on lung injury and inflammation in a triple hit lamb model of Ureaplasma parvum (UP)-induced chorioamnionitis, prematurity, and mechanical ventilation. Methods: Twenty-one preterm lambs were surgically delivered preterm at 129 days after 7 days intrauterine exposure to UP. Sixteen animals were subsequently ventilated for 24 hours and received endotracheal surfactant and intravenous caffeine citrate. Ten animals were randomized to receive twice a high (10 µg/kg) or low dose (1 µg/kg) of nebulized PDE4 inhibitor. Results: Nebulization of high, but not low, doses of PDE4 inhibitor led to a significant decrease in pulmonary PDE activity, and was associated with lung injury and vasculitis, influx of neutrophils, and increased proinflammatory cytokine messenger RNA levels. Conclusion: Contrary to our hypothesis, we found in our model a dose-dependent proinflammatory effect of an inhaled highly selective PDE4 inhibitor in the lung. Our findings indicate the narrow therapeutic range of inhaled PDE4 inhibitors in the preterm population.

Genetic determinants of cellular addiction to DNA polymerase theta.

Polymerase theta (Pol θ, gene name Polq) is a widely conserved DNA polymerase that mediates a microhomology-mediated, error-prone, double strand break (DSB) repair pathway, referred to as Theta Mediated End Joining (TMEJ). Cells with homologous recombination deficiency are reliant on TMEJ for DSB repair. It is unknown whether deficiencies in other components of the DNA damage response (DDR) also result in Pol θ addiction. Here we use a CRISPR genetic screen to uncover 140 Polq synthetic lethal (PolqSL) genes, the majority of which were previously unknown. Functional analyses indicate that Pol θ/TMEJ addiction is associated with increased levels of replication-associated DSBs, regardless of the initial source of damage. We further demonstrate that approximately 30% of TCGA breast cancers have genetic alterations in PolqSL genes and exhibit genomic scars of Pol θ/TMEJ hyperactivity, thereby substantially expanding the subset of human cancers for which Pol θ inhibition represents a promising therapeutic strategy.

A novel fluorescent-colorimetric probe for Al3+ and Zn2+ ion detection with different response and applications in F- detection and cell imaging.

A novel Schiff base fluorescence probe (HL) was synthesized by the condensation of salicylaldehyde and an 8-aminoquinoline derivative. This probe acts as a "turn-on" dual selectivity fluorescence probe for Zn2+ and Al3+ ions, providing different colors and detection limits (DL) of 11.5 and 23.5 nM, respectively. Moreover, when Zn2+ and Al3+ co-exist, HL exhibits a preference for Al3+ by displacing Zn2+ from the HL-Zn2+ complex, realizing a dual-channel signal output for Al3+. The HL-Al3+ system could further discern F- by a "turn-off" fluorescence response with a DL of 86.0 nM. Furthermore, the probe HL was capable of monitoring intracellular Al3+, Zn2+ and F- in living PC12 cells in vitro through fluorescence imaging, which proved its value in potential in vivo applications.

Substituted 1,3-dioxoisoindoline-4-aminoquinolines coupled via amide linkers: Synthesis, antiplasmodial and cytotoxic evaluation.

Synthesis of C-5-substituted 1,3-dioxoisoindoline-4-aminoquinolines having amide group as a spacer was developed with an intent to evaluate their antiplasmodial activities. The synthesized dioxoisoindoline-aminoquinolines tethered with ß-alanine as a spacer and secondary amine as substituent displayed good anti-plasmodial activities. Compound 7j, with an optimum combination of ß-alanine and an ethyl chain length as linker along with diethylamine as the secondary amine counterpart at dioxoisoindoline proved to be most potent and non-cytotoxic with IC50 of 0.097 µM against W2 strain of P. falciparum and a selective index of >2000.

Synthesis and biological evaluation of new quinoline derivatives as antileishmanial and antitrypanosomal agents.

As a part of our project aimed at developing new safe chemotherapeutic agents against tropical diseases, a series of aryl derivatives of 2- and 3-aminoquinoline, some of them new compounds, was designed, synthesized, and evaluated as antiproliferative agents against Trypanosoma cruzi, the parasite responsible for American trypanosomiasis (Chagas' disease), and Leishmania mexicana, the etiological agent of Leishmaniasis. Some of them showed a remarkable activity as parasite growth inhibitors. Fluorine-containing derivatives 11b and 11c were more than twice more potent than geneticin against intracellular promastigote form of Leishmania mexicana exhibiting both IC50 values of 41.9 µM. The IC50 values corresponding to fluorine and chlorine derivatives 11b-d were in the same order than benznidazole against epimastigote form. These drugs are interesting examples of effective antiparasitic agents with outstanding potential not only as lead drugs but also to be used for further in vivo studies. In addition, the obtained compounds showed no toxicity in Vero cells, which makes them good candidates to control tropical diseases. Regarding the probable mode of action, assayed quinoline derivatives interacted with hemin, inhibiting its degradation and generating oxidative stress that is not counteracted by the antioxidant defense system of the parasite.

Antileishmanial activity of a 4-hydrazinoquinoline derivative: Induction of autophagy and apoptosis-related processes and effectiveness in experimental cutaneous leishmaniasis.

Currently, available treatment options for leishmaniasis are limited and unsatisfactory. In a previous study, a quinoline derivative (AMQ-j), exhibited a strong effect against Leishmania amazonensis and its antileishmanial activity was preliminarily associated with mitochondrial dysfunction. The present study further explores the antileishmanial effect of this compound against L. amazonensis, as well as determines the main cellular processes involved in the death of the parasite. Moreover, this study evaluated the in vivo effect of the AMQ-j in BALB/c mice experimentally infected by L. amazonensis. The results showed that the compound AMQ-j induces a set of morphological and biochemical features that could correlate with both autophagy-related and apoptosis-like processes, indicating intense mitochondrial swelling, a collapse of the mitochondrial membrane potential, an abnormal chromatin condensation, an externalization of phosphatidylserine, an accumulation of lipid bodies, a disorganization of cell cycle, a formation of autophagic vacuoles, and an increase of acidic compartments. Treatment with AMQ-j through an intralesional route was effective in reducing the parasite burden and size of the lesion. No significant increase in the serum levels of hepatic or renal damage toxicity markers was observed. These findings contribute to the understanding of the mode of action of quinoline derivatives involved in the death of Leishmania parasites and encourage new studies in other experimental models of Leishmania infection.

Comparison of normal versus imiquimod-induced psoriatic skin in mice for penetration of drugs and nanoparticles.

BACKGROUND: As an immune-mediated skin disease, psoriasis encounters therapeutic challenges on topical drug development due to the unclear mechanism, and complicated morphological and physiological changes in the skin. METHODS: In this study, imiquimod-induced psoriatic mouse skin (IMQ-psoriatic skin) was chosen as the in vitro pathological model to explore the penetration behaviors of drugs and nanoparticles (NPs). RESULTS: Compared with normal skin, significantly higher penetration and skin accumulation were observed in IMQ-psoriatic skin for all the three model drugs. When poorly water-soluble curcumin was formulated as NPs that were subsequently loaded in gel, the drug's penetration and accumulation in both normal and IMQ-psoriatic skins were significantly improved, in comparison with that of the curcumin suspension. Interestingly, the NPs' size effect, in terms of their penetration and accumulation behaviors, was more pronounced for IMQ-psoriatic skin. Furthermore, by taking three sized FluoSpheres® as model NPs, confocal laser scanning microscopy demonstrated that the penetration pathways of NPs no longer followed the hair follicles channels, instead they were more widely distributed in the IMQ-psoriatic skin. CONCLUSION: In conclusion, the alternation of the IMQ-psoriatic skin structure will lead to the enhanced penetration of drug and NPs, and should be considered in topical drug formulation and further clinical practice for psoriasis therapy.

Chitosan-based nanoformulated (-)-epigallocatechin-3-gallate (EGCG) modulates human keratinocyte-induced responses and alleviates imiquimod-induced murine psoriasiform dermatitis.

BACKGROUND: Psoriasis is a chronic and currently incurable inflammatory skin disease characterized by hyperproliferation, aberrant differentiation, and inflammation, leading to disrupted skin barrier function. The use of natural agents that can abrogate these effects could be useful for the treatment of psoriasis. Earlier studies have shown that treatment of keratinocytes and mouse skin with the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) mitigated inflammation and increased the expression of caspase-14 while promoting epidermal differentiation and cornification. However, bioavailability issues have restricted the development of EGCG for the treatment of psoriasis. MATERIALS AND METHODS: To overcome these limitations, we employed a chitosan-based polymeric nanoparticle formulation of EGCG (CHI-EGCG-NPs, hereafter termed nanoEGCG) suitable for topical delivery for treating psoriasis. We investigated and compared the efficacy of nanoEGCG versus native or free EGCG in vitro and in an in vivo imiquimod (IMQ)-induced murine psoriasis-like dermatitis model. The in vivo relevance and efficacy of nanoEGCG formulation (48 µg/mouse) were assessed in an IMQ-induced mouse psoriasis-like skin lesion model compared to free EGCG (1 mg/mouse). RESULTS: Like free EGCG, nanoEGCG treatment induced differentiation, and decreased proliferation and inflammatory responses in cultured keratinocytes, but with a 4-fold dose advantage. Topically applied nanoEGCG elicited a significant (p<0.01) amelioration of psoriasiform pathological markers in IMQ-induced mouse skin lesions, including reductions in ear and skin thickness, erythema and scales, proliferation (Ki-67), infiltratory immune cells (mast cells, neutrophils, macrophages, and CD4+ T cells), and angiogenesis (CD31). We also observed increases in the protein expression of caspase-14, early (keratin-10) and late (filaggrin and loricrin) markers of differentiation, and the activator protein-1 factor (JunB). Importantly, a significant modulation of several psoriasis-related inflammatory cytokines and chemokines was observed compared to the high dose of free EGCG (p<0.05). Taken together, topically applied nanoEGCG displayed a >20-fold dose advantage over free EGCG. CONCLUSION: Based on these observations, our nanoEGCG formulation represents a promising drug-delivery strategy for treating psoriasis and possibly other inflammatory skin diseases.

Adamantane amine-linked chloroquinoline derivatives as chloroquine resistance modulating agents in Plasmodium falciparum.

Previously we have shown that pentacycloundecylamine-chloroquinoline (PCU-CQ) conjugates possess significant chemosensitizing abilities and can circumvent the resistance associated with chloroquine (CQ) resistant plasmodia. In order to further explore structurally related polycyclic compounds as reversed CQ agents we synthesized a series of eight aza-adamantanol (1-4) and adamantane-imine (5-8) CQ conjugates. All conjugates showed limited cytotoxicity against CHO cells (IC50 > 37 µM). Compounds 1, 2 and 5 were highly active (K1 IC50 < 100 nM) exhibiting a 3-4-fold increase in antiplasmodial activity against CQ resistant strain K1 compared to CQ. Reduced cross-resistance (resistance index, RI: 2-4.3) relative to CQ (RI = 38) was also observed for these compounds. Compound 1 which showed an 18-fold enhancement at retaining its activity against the K1 strain compared to CQ is a promising candidate to substitute CQ in P. falciparum resistant malaria.

Low systemic exposure and calcemic effect of calcipotriol/betamethasone ointment in rats with imiquimod-induced psoriasis-like dermatitis.

Vitamin D3 (VD3) analogues-containing ointments are known to occasionally cause hypercalcemia in psoriasis patients, and the frequency of hypercalcemia is suggested to vary based on the VD3 analogue used. In this study, to address the differences in calcemic effects of VD3-containing ointments, the calcemic effects of marketed VD3-containing ointments, including calcipotriol (Cal), maxacalcitol (Max), tacalcitol (Tac), calcipotriol/betamethasone dipropionate (Cal/BDP) and maxacalcitol/betamethasone butyrate propionate (Max/BBP) ointments, were evaluated in a rat model of imiquimod-induced dermatitis. The topical application of Tac, Max and Max/BBP ointments, but not Cal and Cal/BDP ointments, to the imiquimod-induced skin lesions significantly induced an increase in the serum calcium level compared with the vaseline-treated group. Calcemic effect of VD3 analogues in rats treated with VD3-containing ointments was analyzed by evaluating the expression of vitamin D receptor target genes, such as Cyp24a1, Trpv5 and CalbindinD28k, in the intestine and kidney. Real-time reverse transcription PCR (RT-PCR) analysis showed that the renal and intestinal Cyp24a1 expressions in the Cal- and Cal/BDP-treated groups were significantly lower than those in the Tac-, Max- and Max/BBP-treated groups, suggesting that systemic exposure of VD3 analogues in the Cal- and Cal/BDP-treated groups were lower than those in the other ointment-treated groups. In addition, the renal Trpv5 and CalbindinD28k expressions, calcium-transporting genes, were increased in the Max- and Max/BBP-treated groups compared with the Cal- and Cal/BDP-treated groups. Thus, because of the low systemic exposure of VD3 analogues, Cal and Cal/BDP ointments have lower calcemic effect than the other VD3-containing ointments in rats with psoriasis-like dermatitis.

Effect of Topical Application of Black Seed Oil on Imiquimod-Induced Psoriasis-like Lesions in the Thin Skin of Adult Male Albino Rats.

Psoriasis is a chronic inflammatory skin disease that affects about 1%-3% of the world's population. Black seed oil, i.e., the oil extracted from black seeds (Nigella sativa seeds), possesses a broad spectrum of pharmacological actions including anti-inflammatory, immunostimulatory, and antioxidant properties. This study aimed to investigate the effect of black seed oil on imiquimod (IMQ) induced psoriasis-like skin lesions. To this end, 30 male albino rats were divided into three groups: group I, control group; group II, psoriasis-induced group receiving daily topical applications of IMQ cream (5%) on the shaved back skin for 10 consecutive days; and group III, black seed oil group receiving a daily topical dose of black seed oil 5 mg/kg body weight for 10 days after induction of psoriasis. Animals of all groups were sacrificed and specimens obtained from the skin of the central part of the back were processed for histological and immunohistochemical staining with proliferating cell nuclear antigen (PCNA). IMQ application led to epidermal inflammation, hyperplasia and alterations in the normal appearance of keratinocytes with degenerative changes observed at both light and electron microscopic levels. Collagenous fibers were abundant in the dermis and PCNA-positive cells were detected in all layers of the epidermis. However, topical use of black seed oil strongly inhibited IMQ-induced psoriasis-like inflammation and alleviated all epidermal and dermal changes observed after IMQ application, allowing us to conclude that black seed oil can be used as an adjuvant topical therapy for treating psoriasis. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:166-174, 2018. © 2017 Wiley Periodicals, Inc.

In Vivo and In Vitro Activities and ADME-Tox Profile of a Quinolizidine-Modified 4-Aminoquinoline: A Potent Anti-P. falciparum and Anti-P. vivax Blood-Stage Antimalarial.

Natural products are a prolific source for the identification of new biologically active compounds. In the present work, we studied the in vitro and in vivo antimalarial efficacy and ADME-Tox profile of a molecular hybrid (AM1) between 4-aminoquinoline and a quinolizidine moiety derived from lupinine (Lupinus luteus). The aim was to find a compound endowed with the target product profile-1 (TCP-1: molecules that clear asexual blood-stage parasitaemia), proposed by the Medicine for Malaria Venture to accomplish the goal of malaria elimination/eradication. AM1 displayed a very attractive profile in terms of both in vitro and in vivo activity. By using standard in vitro antimalarial assays, AM1 showed low nanomolar inhibitory activity against chloroquine-sensitive and resistant P. falciparum strains (range IC50 16-53 nM), matched with a high potency against P. vivax field isolates (Mean IC50 29 nM). Low toxicity and additivity with artemisinin derivatives were also demonstrated in vitro. High in vivo oral efficacy was observed in both P.berghei and P. yoelii mouse models with IC50 values comparable or better than those of chloroquine. The metabolic stability in different species and the pharmacokinetic profile in the mouse model makes AM1 a compound worth further investigation as a potential novel schizonticidal agent.

Anti-Psoriasis Effects and Mechanisms of Α-(8-Quinolinoxy) Zinc Phthalocyanine-Mediated Photodynamic Therapy.

BACKGROUND/AIMS: The aim of this study was to determine the anti-psoriasis effects of α-(8-quinolinoxy) zinc phthalocyanine (ZnPc-F7)-mediated photodynamic therapy (PDT) and to reveal its mechanisms. METHODS: HaCaT cells were used to observe the influence of ZnPc-F7-PDT on cell proliferation in vitro. The in vivo anti-psoriasis effects of ZnPc-F7-PDT were evaluated using a mouse vagina model, a propranolol-induced cavy psoriasis model and an imiquimod (IMQ)-induced nude mouse psoriasis model. Flow cytometry was carried out to determine T lymphocyte levels. Western blotting was performed to determine protein expression, and a reverse transcription-polymerase chain reaction test was performed to determine mRNA expression. RESULTS: The results showed that ZnPc-F7-PDT significantly inhibited the proliferation of HaCaT cells in vitro; when the light doses were fixed, changing the irradiation time or output power had little influence on the inhibition rate. ZnPc-F7-PDT significantly inhibited the hyperproliferation of mouse vaginal epithelium induced by diethylstilbestrol and improved propranolol- and IMQ-induced psoriasis-like symptoms. ZnPc-F7-PDT inhibited IMQ-induced splenomegaly and T lymphocyte abnormalities. ZnPc-F7-PDT did not appear to change T lymphocytes in the mouse vagina model. ZnPc-F7-PDT down-regulated the expression of proliferating cell nuclear antigen (PCNA), B-cell lymphoma-2 (Bcl-2), interleukin (IL)-17A mRNA and IL-17F mRNA, and up-regulated the expression of Bax. CONCLUSION: In conclusion, ZnPc-F7-PDT exhibited therapeutic effects in psoriasis both in vitro and in vivo and is a potential approach in the treatment of psoriasis. Potential mechanisms of these effects included the inhibition of hyperproliferation; regulation of PCNA, Bcl-2, Bax, IL-17A mRNA and IL-17F mRNA expression; and immune regulation.

GM-CSF in murine psoriasiform dermatitis: Redundant and pathogenic roles uncovered by antibody-induced neutralization and genetic deficiency.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic, Th17-derived cytokine thought to critically contribute to the pathogenesis of diverse autoimmune diseases, including rheumatoid arthritis and psoriasis. Treatment with monoclonal antibodies that block GM-CSF activity is associated with favorable therapeutic effects in patients with rheumatoid arthritis. We evaluated the role of GM-CSF as a potential target for therapeutic interference in psoriasis using a combined pharmacologic and genetic approach and the mouse model of imiquimod-induced psoriasiform dermatitis (IMQPD). Neutralization of murine GM-CSF by an anti-GM-CSF antibody ameliorated IMQPD. In contrast, genetic deficiency in GM-CSF did not alter the course of IMQPD, suggesting the existence of mechanisms compensating for chronic, but not acute, absence of GM-CSF. Further investigation uncovered an alternative pathogenic pathway for IMQPD in the absence of GM-CSF characterized by an expanded plasmacytoid dendritic cell population and release of IFNα and IL-22. This pathway was not activated in wild-type mice during short-term anti-GM-CSF treatment. Our investigations support the potential value of GM-CSF as a therapeutic target in psoriatic disease. The discovery of an alternative pathogenic pathway for psoriasiform dermatitis in the permanent absence of GM-CSF, however, suggests the need for monitoring during therapeutic use of long-term GM-CSF blockade.

Role of MyD88 signaling in the imiquimod-induced mouse model of psoriasis: focus on innate myeloid cells.

Psoriasis is a chronic skin disease associated with deregulated activation of immune cells and keratinocytes. In this study, we used the imiquimod (IMQ)-induced mouse model of psoriasis to dissect better the contribution of hematopoietic and skin-resident stromal cells to psoriasis development. The comparison of disease development in mice carrying the hematopoietic cell-specific deletion of MyD88 (Myd88fl/flVav-cre+ mice) with mice carrying the total MyD88 deficiency (Myd88-/- mice), we show that the progression of skin and systemic inflammation, as well as of epidermal thickening, was completely dependent on MyD88 expression in hematopoietic cells. However, both Myd88-/- mouse strains developed some degree of epidermal thickening during the initial stages of IMQ-induced psoriasis, even in the absence of hematopoietic cell activation and infiltration into the skin, suggesting a contribution of MyD88-independent mechanisms in skin-resident stromal cells. With the use of conditional knockout mouse strains lacking MyD88 in distinct lineages of myeloid cells (Myd88fl/flLysM-cre+ and Myd88fl/flMRP8-cre+ mice), we report that MyD88 signaling in monocytes and Mϕ, but not in neutrophils, plays an important role in disease propagation and exacerbation by modulating their ability to sustain γδ T cell effector functions via IL-1ß and IL-23 production. Overall, these findings add new insights into the specific contribution of skin-resident stromal vs. hematopoietic cells to disease initiation and progression in the IMQ-induced mouse model of psoriasis and uncover a potential novel pathogenic role for monocytes/Mϕ to psoriasis development.