Psoriatic Mice Research Articles

Chlorquinaldol inhibits the activation of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 inflammasome and ameliorates imiquimod-induced psoriasis-like dermatitis in mice

Psoriasis is a common chronic autoinflammatory/autoimmune skin disease associated with elevated pro-inflammatory cytokines. The pivotal role of interleukin (IL)-1β and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome in the pathogenesis of psoriasis has been widely described. Accordingly, the suppression of NLRP3-dependent IL-1β release is a potential therapy for psoriasis. Repurposing marketed drugs is a strategy for identifying new inhibitors of NLRP3 inflammasome activation. Herein, chlorquinaldol (CQD), a historic antimicrobial agent used as a topical treatment for skin and vaginal infections, was found to have a distinct effect by inhibiting NLRP3 inflammasome activation at concentrations ranging from 2 to 6 μM. CQD significantly suppressed apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) oligomerization, NLRP3-ASC interaction, and pyroptosis in macrophages. The levels of cleaved IL-1β and caspase-1 were reduced by CQD in the cell lysates of macrophages, suggesting that CQD acted on upstream of pore formation in the cell membrane. Mechanistically, CQD reduced mitochondrial reactive oxygen species production but did not affect the nuclear factor-κB (NF-κB) pathway. Intraperitoneal administration of CQD (15 mg/kg) for 6 days was found to improve the skin lesions in the imiquimod-induced psoriatic mouse model (male C57BL/6 mice), while secretion of pro-inflammatory cytokines (IL-17 and IL-1β) and keratinocyte proliferation were significantly suppressed by CQD. In conclusion, CQD exerted inhibitory effects on NLRP3 inflammasome activation in macrophages and decreased the severity of psoriatic response in vivo. Such findings indicate that the repurposing of the old drug, CQD, is a potential pharmacological approach for the treatment of psoriasis and other NLRP3-driven diseases.

Coenzyme Q10 loaded lipid-polymer hybrid nanoparticles in gel for the treatment of psoriasis like skin condition

Psoriasis is characterized by severe dermal inflammation caused by pre-oxidants that dominate the skin's antioxidant system. The available therapeutic strategies seeks betterment in terms of cost effectiveness, long-term usage and safety. This research work highlights the use of monolithic polymer-lipid hybrid nanoparticles to deliver coenzyme Q10, a prominent antioxidant and anti-inflammatory biomolecule, to the skin. The system has both polymeric and lipidic characteristics, so each could compensate the other's shortcomings. The particle size, polydispersity index, and encapsulation efficiency of the nanoformulation were found to be 121 ± 11.61 nm, 0.252 ± 0.073, and 78.57 ± 3.88%, respectively, when produced employing the hot homogenization technique. The nanoparticles released CoQ10 steadily and consistently for up to 3 days. Further, the nanoformulation was used as a topical gel (CoQ10–0.06% w/w), and demonstrating non-newtonian rheological characteristics. An imiquimod-induced psoriatic mouse model was used to evaluate the in vivo efficacy of the nanoformulation gel, which produced a significant increase in CoQ10 efficacy when applied topically compared to free CoQ10 gels. Overall, the CoQ10 loaded NanoHybrid gel was found to be efficient for the in vivo application for the treatment of psoriasis like skin conditions.

A combination of linalool and linalyl acetate synergistically alleviates imiquimod-induced psoriasis-like skin inflammation in BALB/c mice.

Introduction: Psoriasis is a chronic inflammatory skin disorder characterized by keratinocyte hyperproliferation and differentiation with increased immune cell infiltration. The anti-psoriatic effect of lavender oil has been reported. However, its phytoconstituents, linalool (L) and linalyl acetate (LA), showed a distinctive affinity with psoriasis targets. Objectives: This investigation was aimed to determine the combined effect of L and LA in ameliorating psoriasis-like skin inflammation and its safety in long-term topical uses. Methods: The combined effect of L and LA was compared with their individual effects. The anti-psoriatic activity was performed using imiquimod (IMQ)-induced psoriasis in BALB/c mice and evaluated to reduce PASI and CosCam scores and Th-1 and Th-17 cell-specific cytokine levels. The acute and repeated dose dermal toxicities were investigated as per the OECD guidelines. Results: L and LA combination (LLA) in the 1:1 w/w ratio at 2% concentration showed a synergistic effect. The combination showed 76.31% and 71.29% recovery in PASI and CosCam Scores; however, L2% and LA2% showed 64.28% and 47.61% recovery in PASI and 64.75 and 56.76% recovery in CosCam scores, respectively. It showed >90% and >100% recovery in Th-17 and Th-1 cell-specific cytokines, respectively, and restored epidermal hyperplasia and parakeratosis toward normal compared with psoriatic mice. A marked reduction in NF-κB, cck6, and the IL-17 expression was also observed in the LLA-treated group. This combination was safe in a therapeutically effective dose for 28 days as no significant changes were observed in organ and body weights, liver and kidney parameters, and differential leukocyte counts. Conclusion: This study proves the synergy between L and LA in a 1:1 w/w ratio at 2% in the treatment of psoriasis-like skin inflammation and provides strong scientific evidence for its safe topical use.

Topical administration of the secretome derived from human amniotic epithelial cells ameliorates psoriasis-like skin lesions in mice

BackgroundPsoriasis is a chronic inflammatory skin disease. Tissue stem cells have exhibited a therapeutic effect on psoriatic mice. However, the therapeutic effect of topical administration of the secretome derived from tissue stem cells on psoriasis has not been reported.MethodsThe secretome from human amniotic epithelial cells (AEC-SC) and human umbilical cord mesenchymal stem cells (UMSC-SC) was topically administrated on the back of imiquimod-induced psoriasis-like mice. Subsequently, we observed the skin lesions and skin inflammation of psoriasis-like mice. Next, we further analyzed the paracrine factors in AEC-SC and UMSC-SC by protein chips. Lastly, the effect of the crucial paracrine factor was investigated by imiquimod-induced psoriasis-like mice.ResultsWe found that AEC-SC had a better therapeutic effect on attenuating psoriasis-like skin lesions including skin scales, skin redness and skin thickness than UMSC-SC, and it had a better regulatory effect on keratinocyte hyperproliferation and altered differentiation. Thus, we focused on AEC-SC. Further study showed that AEC-SC reduced the infiltration of neutrophils and interleukin-17-producing T cells. Next, the analysis of AEC-SC with protein chip revealed that the levels of anti-inflammatory factor interleukin-1 receptor antagonist (IL-1ra) were much higher in AEC-SC compared to that in UMSC-SC. More importantly, the beneficial effect of AEC-SC on psoriasis-like skin lesions and skin inflammation of mice were significantly impaired when neutralizing with IL-1ra antibody, while the recombinant human IL-1ra showed a less protective effect than AEC-SC.ConclusionsThe present study demonstrated that AEC-SC could efficiently ameliorate psoriasis-like skin lesions and skin inflammation and IL-1ra plays an essential role. Therefore, topical administration of AEC-SC may provide a novel strategy for treating psoriasis-like inflammatory skin diseases.

LB964 TET2 participates in the dysregulation of skin barrier in psoriasis

Psoriasis is a chronic inflammatory skin disease. Dysregulation of the epidermal barrier in psoriasis has been demonstrated and epigenetic modifications have been found to be associated with psoriasis. TET2 has dioxygenase activity and oxidizes 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), and is a key regulator of DNA demethylation. There is a lack of studies on the effect of TET2 on the epidermal barrier in psoriasis. We observed reduced expression of TET2 and 5hmc in the lesions of psoriasis patients. In imiquimod psoriatic dermatitis mice, we obtained similar results by immunohistochemistry. We constructed epidermal TET2 conditional knockout mice (TET2CKO). In the imiquimod psoriasis dermatitis model, TET2CKO mice presented more severe erythema, scaling and skin thickness. The TEWL assay was performed on imiquimod-treated mice and was elevated in the TET2CKO group. This indicates that epidermal TET2 deficiency exacerbates psoriatic dermatitis in mice. We next examined the expression of K14, K10, filaggrin, involucrin, which represent proliferation and differentiation, TET2CKO mice showed K14, involucrin increased and K10, filaggrin decreased. TET2 absence may accelerate the proliferation and inhibit differentiation of keratinocytes. We subsequently observed that intercellular linker molecules Claudin-1 and E-cadherin were both downregulated in TET2CKO mice. In conclusion, deletion of epidermal TET2 is involved in dysregulation of the skin barrier. By RNAseq, we found that FLG mRNA is reduced after TET2 knockdown. Deficiency of filaggrin encoded by the FLG gene, leads to impaired epidermal barrier. Filaggrin expression reduced but mutations in the FLG gene have been reported to be rarely observed in psoriasis, therefore we suppose that FLG gene expression might be regulated by TET2, which is an alternative mechanism for barrier dysregulation in non-mutant FLG patients.

Characterization and ex vivo evaluation of excised skin samples as substitutes for human dermal barrier in pharmaceutical and dermatological studies.

Excised animal and human skins are frequently used in permeability testing in pharmaceutical research. Several factors exist that may have influence on the results. In the current study some of the skin parameters that may affect drug permeability were analysed for human, mouse, rat and pig skin. Classic biophysical skin parameters were measured (e.g. pH, hydration, permittivity, transepidermal water loss). Physiological characteristics of the skins were also analysed by confocal Raman spectroscopy, scanning electron microscopy and two-photon microscopy. Based on biophysical testing, skin barrier function was damaged in psoriatic mouse skin and in marketed pig skin. Hydration and pH values were similar among the species, but freezing and thawing reduced the water content of the skins and shifted the surface pH to acidic. Aging reduced hydration and permittivity, resulting in impaired barrier function. Mechanical sensitization used in permeability studies resulted in proportional thinning of dead epidermis. Results indicate that depending on the scientific question it should be considered whether fresh or frozen tissue is used, and for certain purposes rodent skins are well usable. The structure of the skin tissue (ceramide, cholesterol, keratin, natural moisturizing factor or urea) is similar in rats and mice, but due to the higher skin thickness the lipid distribution is different in porcine skin. Psoriasis led to irregular chemical composition of the skin. A comprehensive evaluation of skin samples of four species was performed. The biophysical and microscopic observations should be considered when selecting drug penetration models and experimental conditions.

POS0442 GLPG4399: SELECTIVE SIK3 INHIBITION AS A NOVEL MODE OF ACTION FOR THE TREATMENT OF INFLAMMATORY ARTHRITIC DISEASES (PRECLINICAL)

BackgroundSalt-inducible kinases (SIKs) is a family of kinases with immunomodulatory function identified using a proprietary adenoviral shRNA knockdown target discovery platform. Moreover, SIK inhibition has previously been shown to have a role in inflammatory signalling.1–3 These findings suggest a therapeutic potential for SIK inhibition in inflammatory indications. A medicinal chemistry effort resulted in the development of a first-in-class, oral, selective SIK3 inhibitor: GLPG4399. This compound may be beneficial in inflammatory diseases such as rheumatoid and psoriatic arthritis which are chronic disorders characterized by impaired joint synovial inflammation.ObjectivesOur research aimed to characterize GLPG4399 and explore its impact in arthritis-relevant inflammatory in vitro phenotypic cell assays, and to evaluate the therapeutic potential of selective SIK3 inhibition in in vivo experimental models of arthritis.MethodsThe selectivity and potency of GLPG4399 was profiled using biochemical and target-based cell assays. The mode of action of selective SIK3 inhibition in inflammation was explored in an in vitro panel of innate (monocytes, macrophages, dendritic cells) and adaptive (B and T lymphocytes) immune phenotypic assays and in a lipopolysaccharide (LPS)-stimulated human whole blood assay by measuring the production of inflammatory cytokines. In vivo target engagement was evaluated in an acute LPS-stimulated cytokine release mouse model by measuring plasma tumour necrosis factor (TNF) α levels. The therapeutic efficacy of GLPG4399 was evaluated in vivo in collagen-induced arthritis (CIA) and IL-23-induced psoriatic arthritis mouse models by assessing disease activity endpoints.ResultsGLPG4399 was shown to be a SIK3 inhibitor with high selectivity against a panel of 370 kinases. The wide effect of SIK3 inhibition on key immune cell types was demonstrated by GLPG4399’s reduction of pro-inflammatory cytokines produced by monocytes, macrophages, dendritic cells, B and T lymphocytes in a panel of in vitro innate and adaptive immune phenotypic assays. The biological activity and target engagement of GLPG4399 was further demonstrated by dose-dependent inhibition of TNFα production in vitro in LPS-stimulated human whole blood and in vivo in the blood of LPS-challenged mice. Oral treatment with GLPG4399 in mice resulted in a significant and dose-dependent improvement of disease activity score in both CIA and the psoriatic arthritis disease model. Moreover, bone erosion in CIA and new bone formation in the psoriatic arthritis disease model were significantly reduced.ConclusionOur preclinical findings demonstrate the strong immunomodulatory effect of SIK3 inhibition in arthritis-relevant inflammatory cell assays and highlight the significant preclinical efficacy of GLPG4399 in two experimental arthritis mouse models. The novel mechanisms of action of GLPG4399 represents a promising approach for the treatment of arthritis.

Synthesis and In-Vivo Evaluation of Benzoxazole Derivatives as Promising Anti-Psoriatic Drugs for Clinical Use.

2-(4-Chlorophenyl)-5-benzoxazoleacetic acid (CBA) and its ester, methyl-2-(4-chloro-phenyl)-5-benzoxazoleacetate (MCBA), were synthesized, and their structures were confirmed by 1HNMR, IR, and mass spectrophotometry. The anti-psoriatic activities of CBA and MCBA were tested using an imiquimod (IMQ)-induced psoriatic mouse model, in which mice were treated both topically (1% w/w) and orally (125 mg/kg) for 14 days. The erythema intensity, thickness, and desquamation of psoriasis were scored by calculating the psoriasis area severity index (PASI). The study also included the determination of histopathological alterations in the skin tissues of treated mice. Topical and oral administration of CBA and MCBA led to a reduction in erythema intensity, thickness, and desquamation, which was demonstrated by a significant decrease in the PASI value. In addition, skin tissues of mice treated with CBA and MCBA showed less evidence of psoriatic alterations, such as hyperkeratosis, parakeratosis, scale crust, edema, psoriasiform, and hyperplasia. After administration of either topical or oral dosing, the anti-psoriatic effects were found to be stronger in MCBA-treated than in CBA-treated mice. These effects were comparable to those produced by Clobetasol propionate, the reference drug. This drug discovery could be translated into a potential new drug for future clinical use in psoriasis treatment.

Oxidative stress induces meiotic defects of oocytes in a mouse psoriasis model

Psoriasis, an immune-mediated inflammatory disease, is associated with poor pregnancy outcomes. Emerging evidence indicates that these defects are likely attributed to compromised oocyte competence. Nevertheless, little is known about the underlying associated mechanisms between psoriasis and poor oocyte quality. In this study, we construct an imiquimod-induced chronic psoriasis-like mouse model to review the effects of psoriasis on oocyte quality. We discover that oocytes from psoriasis-like mice display spindle/chromosome disorganization, kinetochore-microtubule mis-attachment, and aneuploidy. Importantly, our results show that melatonin supplement in vitro and in vivo not only increases the rate of matured oocytes but also significantly attenuates oxidative stress and meiotic defects by restoring mitochondrial function in oocytes from psoriasis-like mice. Altogether, our data uncover the adverse effects of psoriasis symptoms on oocytes, and melatonin supplement ameliorates oxidative stress and meiotic defects of oocytes from psoriatic mice.

3, 3′- diindolylmethane hinders IL-17A/IL-17RA interaction and mitigates imiquimod-induced psoriasiform in mice

Psoriasis is a highly inflammatory autoimmune-mediated skin disease. The strongest evidence has pointed to the influential role of interleukin (IL) −17A in the aberrant pathology of psoriasis. Henceforth, targeting the IL-17A cytokine is of prime importance in controlling the disease severity of psoriasis. Reportedly, 3, 3′- diindolylmethane (DIM) is a phytochemical that alleviated acute atopic dermatitis. Howbeit, the therapeutic intervention of DIM against IL-17A/IL-17RA interaction and its signaling mediated pathogenesis in psoriasis remains unexplored. In the current report, we decoded the molecular basis of DIM in psoriasis. Docking analysis has reported that DIM identified an IL-17A binding region in the functional fibronectin-III-like domain of IL-17RA and abrogated IL-17A/IL-17RA interaction. In-vitro experiments demonstrated that DIM impeded IL-17A mediated hyper-proliferative phenotype of psoriatic-like keratinocytes. Furthermore, DIM abated the catabolic effects of IL-17A stimulated expression of pathogenic mediators like HMGB-1, Cyr-61, CCL-20, and VEGF via blunted activation of JAK/STAT pathway in psoriatic like keratinocytes. Profoundly, DIM restricted the reprogramming of psoriatic-like keratinocytes to overexpress IL-17RA in concert with IL-17A stimulation. In line with in-vitro studies, DIM also ameliorated skin lesions and epidermal hyperplasia in an imiquimod-induced mice model of psoriasis. Additionally, DIM also reduced STAT-3 phosphorylation and associated expression of Cyr-61, CCL-20, and VEGF in psoriatic mice. However, if DIM has a direct effect on STAT-3 inhibition or it negatively regulates STAT-3 function via blockade of IL-17A/IL-17RA interaction needs to be investigated in the future. Conclusively, our studies demonstrated that the blockade of IL-17A/IL-17RA interaction is a novel therapeutic perspective of DIM against the progression of psoriasis disease.

Chloroform Extract of Plumbago zeylanica Linn. Roots Ameliorates the Epidermal Thickness of Imiquimod-induced Psoriatic Mice through Cell Cycle and Apoptosis


 Introduction: Psoriasis vulgaris is a chronic skin disease which is characterized by recurrent scales on skin. The global prevalence of this disease has increased in ten years. Plumbagin is an active compound in the P. zeylanica Linn. Some recent studies revealed that P. zeylanica Linn extracts have the antiproliferative activity, which is used for treatment of some human diseases. The aim of this study was to investigated the effect of Chloroform extract of P. zeylanica Linn roots (CEP) on epidermal thickness of Imiquimod-induced psoriatic mice. 
 
 
 Methods: This was a post-test only control group design. A total of 42 male BALB/c mice was divided into six groups. Mice in treatment groups orally received 25, 50, and 100 mg/kg body weight CEP, respectively while positive control orally received 1 mg/kg body weight Methotrexate for seven days. Evaluation of epidermal thickness based on histological changes, serum IL-23 level by ELISA, and Cyclin-dependent kinase 2, Cyclin A, and Caspase-3 expressions by immunohistochemistry.
 
 
 Results: Administrations of CEP decreased the epidermal thickness of psoriatic plaques in all treatment groups (p = 0.002, 0.003, and 0.016 respectively) compared to negative control but it did not reduce the serum IL-23 level. The expressions of CDK2 and Cyclin A reduced in T2 and T3 groups and the expression of Caspase-3 increased was only in T3 group. 
 
 
 Conclusion: Chloroform extract of P. zeylanica Linn roots administrations reduce the epidermal thickness of Imiquimod-induced psoriatic mice by inhibition of keratinocyte cell cycle and induction of Caspase-3 expression.

Therapeutic effects of the extract of Sancao Formula, a Chinese herbal compound, on imiquimod-induced psoriasis via cysteine-rich protein 61

ObjectivePsoriasis is a common chronic inflammatory skin disease that is prone to recurrence, and the proinflammatory factor, cysteine-rich protein 61 (Cyr61), is important in its pathophysiology. Long-term clinical practice has shown that Sancao Formula (SC), a Chinese herbal compound, is effective in the treatment of psoriasis, but the precise mechanism remains unknown. In this study, we investigate the mechanism by which SC extract alleviates imiquimod (IMQ)-induced psoriasis. MethodsThe expression of Cyr61 in psoriatic lesions and normal healthy skin was detected using immunohistochemical analysis to investigate the biological role of Cyr61 in models of psoriatic inflammation. A psoriatic mouse model was established by topical application of IMQ, and the effect of topical application of SC extract was evaluated using the psoriasis area and severity index (PASI) score, hematoxylin-eosin staining, and histopathological features of the skin. Next, a HaCaT cell inflammation model was established using interferon-γ (IFN-γ), and the effect of SC extract on the mRNA and protein levels of Cyr61 and intercellular cell adhesion molecule-1 (ICAM-1) was confirmed using Western blot and quantitative real-time polymerase chain reaction analyses. ResultsImmunohistochemical staining showed that the expression of Cyr61 in psoriatic lesions was higher than that in normal skin samples (78.26% vs 41.18%, P < 0.05), and the number of Cyr61-positive cells in psoriatic lesions was also significantly higher than in normal skin (18.66 ± 2.51 vs 4.33 ± 1.52, P < 0.05). Treatment in mice with IMQ-induced psoriasis showed that SC extract could significantly improve the inflammatory phenotype, PASI score (10.875 ± 0.744 vs 3.875 ± 0.582, P < 0.05), and pathological features compared with those in IMQ model group; SC treatment was also associated with decreased levels of Cyr61 and ICAM-1. In the IFN-γ-induced inflammatory cell model, the mRNA and protein levels of Cyr61 and ICAM-1 were upregulated, while the SC extract downregulated the levels of Cyr61 and ICAM-1. ConclusionThe results provide a theoretical basis for the involvement of Cyr61 in the pathogenesis of psoriasis, and suggest that SC should be used to target Cyr61 for the prevention of psoriasis recurrence.

Regulation of Janus Kinase-signal Transducers and Activators of Transcription Pathways in Psoriatic Mice by Chinese Herbal Compound and Efficacy of Chinese Traditional Medicine under Nano-suspension Technology.

The mechanism of the treatment of psoriasis-like mice with the Chinese herbal compound YinXie No.1 prepared by nano-suspension technology was investigated based on Janus kinase-signal transducers and activators of transcription (JAKs/STATs) pathway. The high-pressure homogenization technology was used in the preparation of the YinXie No.1 nano-suspensions. Then, 50 Kunming mice were equally classified into the negative control group (NC), the psoriasis model group (PsM) prepared with 5% imiquimod cream on the back, the Tripterygium glycosides-gavage group (TrG), the YinXie No.1-gavage group (YX1), and the YinXie No.1 nano suspension group (Nano-YX1). The pathological changes and the differential expressions of STAT3 and STAT5 were compared in each group after the treatment. The results showed that the particle size of nano-suspension powder was smaller and had strong stability compared with the active pharmaceutical ingredient (API). Compared with the NC group, psoriasis-like lesions were observed in the PsM group. Compared with the PsM group, the conditions of the erythema on skin lesions, the mRNA expression of STAT3 and STAT5, and protein expression of p-STAT3 and p-STAT5 in the TrG group, YX1 group, and Nano-YX1 group were notably decreased (P<0.05). Compared with the TrG group and YX1 group, the improvement effect of various indexes in the Nano-YX1 group was closer to that in the NC group, but there were differences between the NC group (P<0.05). Chinese herbal compound was helpful to regulate and control the JAKs/STATs pathway to improve the symptoms of psoriasis mice, and the preparation of Chinese herbal compound decoction by nano-suspension technology could improve the therapeutic effect.

Alpha-7 nicotinic acetylcholine receptor agonist alleviates psoriasis-like inflammation through inhibition of the STAT3 and NF-\u03baB signaling pathway

Psoriasis is a chronic inflammatory cutaneous disease; it has been discovered that stimulation of the nervous system increases susceptibility to psoriasis. Although the cholinergic anti-inflammatory pathway, which is mediated by the alpha-7 nicotinic acetylcholine receptor (α7nAChR), is critical for controlling multiple types of inflammation, its expression pattern and pathogenesis function in psoriatic lesioned skin tissue are unknown. We hereby analyzed the expression of α7nAchR in human and mouse psoriatic skin tissue. In vivo, PNU-282987 or Methyllycaconitine, a specific agonist or antagonist of α7nAchR, were administered to imiquimod (IMQ)-induced psoriatic mouse models. The macroscopic appearance and histopathological features of the psoriatic mice skin were evaluated. In addition, cell proliferation and differentiation markers were investigated. The level of pro-inflammatory cytokines released from the lesioned skin, as well as the activation of the relevant signaling pathways, were measured. Our findings indicated that psoriatic lesional skin expressed an increased level of α7nAChR, with its tissue distribution being primarily in skin keratinocytes and macrophages. In an IMQ-induced murine psoriasis model, α7nAChR agonist PNU-282987 treatment alleviated psoriasis-like inflammation by down-regulating the expression of multiple types of pro-inflammatory mediators and normalized keratinocyte proliferation and differentiation, whereas α7nAChR antagonist treatment exacerbated its effect. Mechanically, we observed that activation of the α7nAChR inhibited the activation of the STAT3 and NF-κB signaling pathways in in vitro cultured HaCaT cells induced by Th17-related cytokine IL-6/IL-22 or Th1-related cytokine TNF-α. Taken together, these findings demonstrate that attenuation of psoriatic inflammation via the cholinergic anti-inflammatory pathway is dependent on α7nAChR activation.

Mannan-binding lectin exacerbates the severity of psoriasis by promoting plasmacytoid dendritic cell differentiation via the signal transducer and activator of transcription 3-interferon regulatory factor 8 axis.

Psoriasis is a chronic inflammatory skin disease mediated by host immune responses. Plasmacytoid dendritic cells (pDC) and interferon (IFN)-α secreted by pDC are involved in the initiation of psoriasis. Mannan-binding lectin (MBL), a vital component of the complement pathway, plays a critical role in innate immune defense and the inflammatory response. Our previous study found that MBL could exacerbate skin inflammation in psoriatic mice, but the effect of MBL on pDC remains unstudied. Herein, we revealed that the circulating level of MBL was elevated in patients with psoriasis compared with the healthy controls. Moreover, the MBL level was positively correlated with disease severity, relative inflammatory cytokine levels, and peripheral blood (PB) pDC frequency in psoriasis. An in vitro study determined that the MBL protein could promote the differentiation of human pDC and upregulate the production of relative inflammatory cytokines and chemokines. Additionally, MBL-deficient (MBL-/- ) mice exhibited decreased accumulation of pDC in lymph nodes, spleens, and skin lesions with reduced secretion of pDC-related cytokines compared with wild-type (WT) mice in the preliminary stage of psoriasis induced by imiquimod. Notably, the differentiation of pDC from bone marrow (BM) cells derived from MBL-/- mice was weakened compared with that from WT mice upon Fms-like tyrosine kinase 3 ligand (Flt3L) incubation. Mechanistic research indicated that the signal transducer and activator of transcription 3 (STAT3)-interferon regulatory factor 8 (IRF8) axis was responsible for MBL-modulated pDC differentiation. In summary, these results suggest that MBL exacerbates the severity of psoriasis by enhancing pDC differentiation and pDC-related cytokine secretion via the STAT3-IRF8 axis, thus providing a new target for psoriasis treatment.

Punicalagin Alleviates Psoriasis by Inhibiting NF-κB-Mediated IL-1β Transcription and Caspase-1-Regulated IL-1β Secretion.

Psoriasis is a chronic and inflammatory skin disorder characterized by inflammation and epidermal hyperplasia. Punicalagin (PUN) is a main active ingredient of pomegranate (Punica granatum L.) peel with multiple biological activities, such as antibacterial, antioxidant and anti-tumor effects. However, the potential effect of PUN on psoriasis remains unknown. In this study, we want to investigate the pharmacological effect of PUN on psoriasis by using imiquimod (IMQ)-induced psoriatic mice model in vivo and tumor necrosis factor a (TNF-α) and interleukin-17A (IL-17A)-stimulated HaCaT cells in vitro. Our results showed that PUN can effectively alleviate the severity of psoriasis-like symptoms. Mechanistically, PUN potently suppresses the aberrant upregulation of interleukin-1β (IL-1β) and subsequent IL-1β-mediated inflammatory cascade in keratinocytes by inhibiting the nuclear factor kappa B (NF-κB) activation and cleaved caspase-1 expression in vitro and in vivo. Taken together, our findings indicate that PUN can relieve psoriasis by repressing NF-κB-mediated IL-1β transcription and caspase-1-regulated IL-1β secretion, which provide evidence that PUN might represent a novel and promising candidate for the treatment of psoriasis.

Pinocembrin Reduces Keratinocyte Activation and Ameliorates Imiquimod-Induced Psoriasis-like Dermatitis in BALB/c Mice through the Heme Oxygenase-1/Signal Transducer and Activator of Transcription 3 Pathway.

Psoriasis is an autoimmune disease characterized by chronic skin inflammation and excessive keratinocyte proliferation. The itchy, scaly, and erythematous lesions present on psoriatic skin negatively affect patients' quality of life. Pinocembrin is a flavonoid present in propolis, fruits, and vegetables. It exerts neuroprotective effects and was used for treating ischemic stroke in a human clinical trial. However, the effects of pinocembrin on psoriasis have never been examined. In this study, we evaluated the effects of pinocembrin on human HaCaT keratinocytes and BALB/c mice with imiquimod- (IMQ-) induced psoriatic dermatitis. In interferon-γ- (IFN-γ-) activated HaCaT cells, pinocembrin reduced the expression of inflammatory cytokines, namely, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and keratinocyte proliferation markers, namely, keratin (K)16, K17, and Ki-67. The mechanism underlying these inhibitory effects involved the regulation of the heme oxygenase- (HO-) 1/signal transducer and activator of transcription (STAT) 3 pathway. In the IMQ-induced psoriatic dermatitis mouse model, the topical application of pinocembrin significantly ameliorated the Skin Psoriasis Area and Severity Index score, epidermal thickness, inflammation, hyperplasia, hyperkeratosis, and cluster of differentiation (CD) 4+ T-cell infiltration. Expression of the inflammatory cytokines and keratinocyte proliferation markers in dorsal skin was significantly decreased in the pinocembrin-treated group. Meanwhile, in lesional skin, the expression of HO-1 was upregulated, but that of phospho-STAT3 (pSTAT3) was downregulated. Collectively, our results indicated the therapeutic potential of pinocembrin. Additional studies are warranted to evaluate its clinical benefits in patients with psoriasis.

Perillyl alcohol inhibits keratinocyte proliferation and attenuates imiquimod-induced psoriasis like skin-inflammation by modulating NF-κB and STAT3 signaling pathways

Psoriasis is a chronic inflammatory and proliferative skin disease characterized by pathological skin lesions which significantly impact the quality of life. Recent studies have been proven that inhibitors of farnesyltransferase enzyme showed significant anti-psoriatic activity. Perillyl alcohol (POH) is one such natural molecule having anti proliferative, anti-inflammatory and anti-oxidant properties by inhibiting farnesyltransferase enzyme which further down regulates NF-κB and STAT3 via Ras/Raf/MAPK pathway. Hence, in the current study we aimed to find the effect of POH on human keratinocytes (HaCat) cells in in-vitro and IMQ induced psoriatic like skin inflammation model in mice. POH significantly decreased the intracellular ROS levels and inhibited the phosphorylation of NF-κB and STAT3 in in-vitro. It was found that POH (200 mg/kg, topical application) has reduced the epidermal hyperplasia, psoriasis area and severity index (PASI) scoring; splenomegaly in imiquimod (IMQ) induced psoriatic mice. Further, POH treatment has decreased the pro-inflammatory serum cytokine levels such as IL-6, IL-12/23, TNF-α and IL-1β and also reduced the expression levels of various inflammatory proteins, COX-2, iNOS, IL-17A, IL-22, NF-кB and STAT3 evidenced by Immunoblotting studies from skin samples. The levels of endogenous antioxidants like glutathione GSH, SOD, Nrf2 were restored to normal levels upon POH treatment. POH downregulated the proteins levels of TLR7, TLR8, CyclinD1 and mRNA expression of Bcl-2 in the skin samples when compared to the IMQ group. POH has ameliorated the hyper-keratosis and acanthosis which was evidenced by histopathology. Collectively, our results suggest that POH has a promising therapeutic application for ameliorating psoriasis-like skin inflammation.

Development and In Vitro/In Vivo Evaluation of pH-Sensitive Polymeric Nanoparticles Loaded Hydrogel for the Management of Psoriasis.

Methotrexate (MTX), the gold standard against psoriasis, poses severe problems when administered systemically viz increased toxicity, poor solubility and adverse reactions. Hence, a topical formulation of MTX for the management of psoriasis can be an effective approach. The present study aimed to develop an MTX based nanoparticle-loaded chitosan hydrogel for evaluating its potential efficacy in an imiquimod-induced psoriatic mice model. MTX-NPs loaded hydrogel was prepared and optimized using the o/w emulsion solvent evaporation method. Particle size, zeta potential, entrapment efficiency, in vitro drug release, ex vivo permeation, skin irritation and deposition studies were performed. Psoriatic Area and Severity Index (PASI) score/histopathological examinations were conducted to check the antipsoriatic potential of MTX-NPs loaded hydrogel using an imiquimod (IMQ)-induced psoriatic model. Optimized MTX-NPs showed a particle size of 256.4 ± 2.17 nm and encapsulation efficiency of 86 ± 0.03%. MTX-NPs loaded hydrogel displayed a 73 ± 1.21% sustained drug release in 48 h. Ex vivo permeation study showed only 19.95 ± 1.04 µg/cm2 of drug permeated though skin in 24 h, while epidermis retained 81.33% of the drug. A significant decrease in PASI score with improvement to normalcy of mice skin was observed. The developed MTX-NPs hydrogel displayed negligible signs of mild hyperkeratosis and parakeratosis, while histopathological studies showed healing signs of mice skin. So, the MTX-NPs loaded hydrogel can be a promising delivery system against psoriasis.

A Traditional Chinese Medicine Formula Danshen Baibixiao Ameliorates Imiquimod-Induced Psoriasis-Like Inflammation in Mice.

Background: Danshen Baibixiao (DB) is a traditional Chinese medicine formula, which has been used to treat psoriasis for decades. Although DB shows good efficacy in clinical practice, the pharmacological effects and underlying mechanisms of DB remain elusive. This study aimed to evaluate the anti-psoriatic effects of DB and explore its underlying mechanisms in an imiquimod (IMQ)-induced psoriasis-like mouse model. Materials and methods: DB was orally administered on IMQ-induced psoriatic mice. Psoriasis area severity index (PASI) was used to evaluate the severity of the inflammation in skin, and histological changes were evaluated by hematoxylin and eosin (H and E) staining. Levels of inflammatory cytokines, such as tumor necrosis factor α (TNF-α), interleukin (IL)-17A, IL-23, IL-6, IL-1β and IL-22 in serum were assessed by enzyme-linked immunosorbent assay (ELISA). mRNA expressions of IL-17A, IL-23, IL-6 and IL-22 were determined by real-time polymerase chain reaction (PCR). Expression levels of proteins related to NF-κB, STAT3 and MAPKs signaling pathways were measured by western blotting (WB). Results: DB significantly ameliorated the psoriatic symptoms in IMQ-induced mice. The serum levels of inflammatory cytokines (TNF-α, IL-17A, IL-23, IL-6, IL-1β and IL-22) were decreased, and mRNA expressions of IL-17A, IL-23, IL-6 and IL-22 in skin tissues were down-regulated. Moreover, WB analysis indicated that DB inhibited the activation of NF-κB, STAT3 and MAPKs signaling pathways. Conclusion: This study confirms the anti-psoriatic activity of DB in IMQ-induced psoriasis-like mice. The possible mechanism may relate to the activities of regulating the IL-23/TH-17 axis and suppressing the activation of NF-κB, STAT3 and MAPKs signaling pathways.