Psoriasis-like Skin Lesions In Mice Research Articles

Metabolic Profiling for Unveiling Mechanisms of Kushenol F against Imiquimod-Induced Psoriasis with UHPLC/MS Analysis.

Psoriasis is a common chronic immune-mediated inflammatory skin disorder. Sophora flavescens Alt. (S. flavescens) has been widely acknowledged in the prevention and treatment of psoriasis. Kushenol F (KSCF) is a natural isopentenyl flavonoid extracted from the root of S. flavescens. We aimed to investigate the effect and mechanism of KSCF on imiquimod (IMQ)-induced psoriasis-like skin lesions in mice. A mouse model of psoriasis was induced with 5% IMQ for 5 days, and the mice were given KSCF dermally for 5 days. Changes in skin morphology, the psoriasis area, the severity index (PASI), and inflammatory factors of psoriasis-like skin lesions were evaluated. Metabolites in the psoriasis-like skin lesions were analyzed with ultra-high-performance liquid chromatography/mass spectrometry followed by a multivariate statistical analysis to identify the differential metabolites and metabolic pathway. The results of the present study confirmed that KSCF significantly reduced PASI scores, epidermal thickening, and epidermal cell proliferation and differentiation. KSCF also reduced the levels of interleukin (IL)-1β, IL-6, IL-8, IL-17A, IL-22, IL-23, and tumor necrosis factor (TNF)-α in the injured skin tissues while increasing IL-10 content. KSCF significantly regulated metabolites in the skin samples, and a total of 161 significant metabolites were identified. These differential metabolites involved sphingolipid and linoleic acid metabolism and steroid hormone biosynthesis. Collectively, KSCF inhibited the inflammatory response to prevent IMQ-induced psoriasis-like skin lesions in mice by call-backing the levels of 161 endogenous metabolites and affecting their related metabolic pathways. KSCF has the potential to be developed as a topical drug for treating psoriasis symptoms.

Cornuside alleviates psoriasis-like skin lesions in mice by relieving inflammatory effects

Psoriasis is a chronic inflammatory skin disease substantially affecting the quality of life, with no complete cure owing to its complex pathogenesis. Cornuside, a major bioactive compound present in Cornus officinalis Sieb. et Zucc., which is a well-known traditional Chinese medicine with a variety of biological and pharmacological activities, such as anti-apoptotic, antioxidant, and anti-inflammatory properties. However, its effects on psoriasis remain unclear. Our preliminary analysis of network pharmacology showed that cornuside may be involved in psoriasis by regulating the inflammatory response and IL-17 signaling pathway. Thus, we investigated the protective role and mechanism of cornuside in the pathogenesis of psoriasis in an imiquimod (IMQ)-induced psoriasis mouse model. In-vivo experiments demonstrated that cornuside-treated mice had reduced skin erythema, scales, thickness, and inflammatory infiltration. The Psoriasis Area Severity Index score was significantly lower than that of the IMQ group. Flow cytometry analysis indicated that cornuside effectively inhibited Th1- and Th17-cell infiltration and promoted aggregation of Th2 cells in skin tissues. Cornuside also inhibited the infiltration of macrophages to the skin. Furthermore, in-vitro experiments indicated that cornuside also decreased the polarization of M1 macrophages and reduced the levels of associated cytokines. Western blotting demonstrated that cornuside suppressed the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular receptor kinase (ERK) in bone marrow-derived macrophages. Our findings indicate that cornuside has a protective effect against IMQ-induced psoriasis by inhibiting M1 macrophage polarization through the ERK and JNK signaling pathways and modulating the infiltration of immune cells as well as the expression of inflammatory factors.

Geniposide alleviates imiquimod-induced psoriasis-like skin lesions in mice via inhibition of angiogenesis

In this study, we aimed to evaluate the protective effect of geniposide (GEN) on imiquimod (IMQ)-induced psoriasis-like skin lesions in mice. Firstly, visual changes of psoriatic skin lesions were observed and the severity was recorded using psoriasis area and severity index (PASI) score. Histological changes were assessed by HE staining for epidermal thickness and Masson’s staining for collagen fibers. Then, photographs of microvascular inside the skin were taken for macroscopic observation, and microscopic changes associated with angiogenesis were evaluated. Furthermore, expression of angiogenic factors were analyzed by ELISA, immunohistochemistry and immunofluorescence, separately. Lastly, the expression of VEGFR signaling-related proteins was detected by WB. Compared with control, IMQ drove a significant increment of epidermal thicknesses with higher PASI scores and more dermal collagen deposition. IMQ treatment led to abnormal keratinocyte proliferation, increased microvascular inside skin, growing production of angiogenesis-related factors, up-regulated expression of VEGFR1 and VEGFR2, and enhanced phosphorylation of p38. However, GEN significantly ameliorated the psoriatic skin lesions, the epidermal thickness, the formation of collagen fibers, and abnormal keratinocyte proliferation. Importantly, GEN inhibited angiogenesis, the production of angiogenic factors (VEGF-A, Ang-2, TNF-α, and IL-17A), and the proliferation of vascular endothelial cells. Simultaneously, GEN curbed the expression of VEGFR1, VEGFR2, p38, and P-p38 proteins involved in VEGFR signaling. Of note, the suppressive effect of GEN was reversed in the HUVECs with over-expressed VEGFR1 or VEGFR2 related to the cells without transfection. These findings suggest that VEGFR1 and VEGFR2 participate in the anti-angiogenesis of GEN in IMQ-induced psoriasis-like skin lesions in mice.

Ze-Qi-Tang formula inhibits MDSCs glycolysis through the down-regulation of p21/Hif1α/Glut1 signal in psoriatic-like mice

BackgroundPsoriasis is a chronic immune-mediated inflammatory skin disease that affects the quality of life and mental health of approximately 150 million people worldwide. Ze-Qi-Tang (ZQT) is a classic compound used in China for lung disease; however, its mechanism of action in psoriasis remains unclear. This study aimed to investigate the therapeutic effect of the ZQT formula on psoriasis and explore the underlying molecular mechanisms. MethodsPeripheral blood samples were collected from patients with psoriasis and healthy individuals. Flow cytometry was used to detect changes in the proportions of myeloid-derived suppressor cells (MDSCs) and other immune cells. Psoriasis was induced in mice by the daily application of imiquimod. ZQT was administered separately or in combination with anti-Gr1 antibody to deplete MDSC. The glycolysis levels of the MDSCs were detected using a Seahorse analyzer. The p21/Hif1α/Glut1 pathway was identified and validated by mRNA sequence, RT-qPCR, WB, IF, and the application of p21 inhibitor UC2288. ResultsThe number of MDSCs was significantly increased in patients with psoriasis, with the increased expression of p21, Hif1α, and Glut1 in MDSCs. ZQT significantly alleviated psoriasis-like skin lesions in mice. ZQT formula significantly reduced the number of MDSCs in psoriatic-like mice and enhanced their suppressive capacity for T cells. The efficacy of ZQT in alleviating psoriatic dermatitis is compromised by MDSC depletion. ZQT decreased the expressions of p21, Hif1α, and Glut1-induced glycolysis in MDSCs, thereby inhibiting Th17 cell differentiation. ConclusionThese suggest that ZQT alleviates IMQ-induced psoriatic dermatitis, by inhibiting p21/Hif1α/Glut1-induced glycolysis in MDSCs.

MiR-26a-5p inhibits the proliferation of psoriasis-like keratinocytes in vitro and in vivo by dual interference with the CDC6/CCNE1 axis.

Psoriasis is a chronic inflammatory proliferative dermatological ailment that currently lacks a definitive cure. Employing data mining techniques, this study identified a collection of substantially downregulated miRNAs (top 10). Notably, 32 targets were implicated in both the activation of the IL-17 signaling pathway and cell cycle dysregulation. In silico analysis revealed that one of these miRNAs, miR-26a-5p, is a highly conserved cross-species miRNA. Strikingly, the miR-26a-5p sequences in humans and mice are identical, and mmu-miR-26a-5p was found to target the same 7 cell cycle targets as its human counterpart, hsa-miR-26a-5p. Among these targets, CDC6 and CCNE1 were the most effective targets of miR-26a-5p, which was further validated in vitro using a dual luciferase reporter system and qPCR assay. The therapeutic assessment of miR-26a-5p revealed its remarkable efficacy in inhibiting the proliferation and G1/S transition of keratinocytes (HaCaT and HEKs) in vitro. In vivo experiments corroborated these findings, demonstrating that miR-26a-5p effectively suppressed imiquimod (IMQ)-induced psoriasis-like skin lesions in mice over an 8-day treatment period. Histological analysis via H&E staining revealed that miR-26a-5p treatment resulted in reduced keratinocyte thickness and immune cell infiltration into the spleens of IMQ-treated mice. Mechanistic investigations revealed that miR-26a-5p induced a cascade of downregulated genes associated with the IL-23/IL-17A axis, which is known to be critical in psoriasis pathogenesis, while concomitantly suppressing CDC6 and CCNE1 expression. These findings were corroborated by qPCR and Western blot analyses. Collectively, our study provides compelling evidence supporting the therapeutic potential of miR-26a-5p as a safe and reliable endogenous small nucleic acid for the treatment of psoriasis.

Xiaoyin Jiedu Granules may alleviate psoriasis-like skin diseases in mice by regulating sphingosine 1-phosphate receptor expression and reducing Th17 cells

Sphingosine-1-phosphate (S1P) is associated with the onset and severity of psoriasis, a chronic inflammatory skin disease linked to innate and adaptive immune responses. This study explores the therapeutic effect of Xiaoyin Jiedu Granules, a combination of traditional Chinese medicines, on psoriasis-like skin lesions in mice and the underlying mechanism. We used imiquimod (IMQ) to induce psoriasis-like dermatitis in mice; the effects of Xiaoyin Jiedu Granules on S1P receptors (S1PRs) were investigated using histology and immunohistochemistry. The effects of Xiaoyin Jiedu Granules on the proliferation, differentiation, and activation of the NF-κB pathway in keratinocytes were verified using quantitative polymerase chain reaction (qPCR) and western blotting analyses. CD4+Th17 cells were screened using flow cytometry; the effects of Xiaoyin Jiedu Granules on the differentiation of Th17 cells and the content of related inflammatory factors were also verified. S1PR1-5 was highly expressed in psoriatic lesions. Xiaoyin Jiedu Granules significantly inhibited the secretion of proliferation-related proteins (K6, K16, K17, and IL-36γ) and proinflammatory cytokines (IL-17 and IL-22), transformation of Th17 cells, and activation of the NF-κB pathway and effectively alleviated IMQ-induced psoriasis-like dermatitis. Overall, our findings indicate that Xiaoyin Jiedu Granules have anti-inflammatory activity against S1PR expression, keratinocytes, and immune cells and can therefore mitigate psoriasis. Inhibiting the expression of S1PRs may be an effective treatment strategy against psoriasis.

Kaempferol modulates IFN-γ induced JAK-STAT signaling pathway and ameliorates imiquimod-induced psoriasis-like skin lesions

Immune-mediated inflammation contributes to the development of psoriasis. However, long-term treatment with global immunosuppressive agents may cause a variety of side effects including recurrent infections. Kaempferol (KP), a natural flavonol, present in various plants is proposed to be useful for the treatment of psoriasis patients. Nevertheless, an explicit understanding of KP induced mechanisms is a prerequisite for its use in clinics. Therefore, we investigated the therapeutic effects and potential mode of action of KP using IFN-γ induced HaCaT cells and imiquimod-induced psoriasis-like skin lesions in mice. In this study, we found KP reduced intracellular ROS production, inhibited rhIFN-γ-induced IFN-γR1 expression, and up-regulated SOCS1 levels in HaCaT cells. In addition, KP inhibited rhIFN-γ-induced phosphorylation of JAK-STAT signaling molecules in HaCaT cells. Most importantly, KP alleviated imiquimod-induced psoriasis-like skin lesions in mice, histopathology and proportion of DCs in the skin. Besides, it reduced the population of γδT17 cells in the lymph nodes of the psoriatic mice and also decreased the gene expression of many proinflammatory cytokines, including interleukin IL-23, IL-17A, TNF-α, IL-6, and IL-1β in addition to down-regulation of the proinflammatory JAK-STAT signaling pathway. Thus, KP modulated IFN-γ induced JAK-STAT signaling pathway by inducing IFN-γR1 expression and up-regulating SOCS1 expression. In addition, KP also ameliorated imiquimod-induced psoriasis by reducing the dendritic cell numbers, and γδT17 cell population, along with down- modulation of the JAK-STAT pathway.

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.

Long-Acting β2 Adrenergic Receptor Agonist Ameliorates Imiquimod-Induced Psoriasis-Like Skin Lesion by Regulating Keratinocyte Proliferation and Apoptosis.

Psoriasis is a chronic inflammatory disease that affects approximately 1%–5% of the population worldwide. Considering frequent relapse, adverse drug reactions, and large costs of treatment, it is urgent to identify new medications for psoriasis. Keratinocytes play an essential role during psoriasis development, and they express high levels of β2-Adrenergic receptor (β2-AR), which increases intracellular cAMP levels when activated. Increased level of cAMP is associated with the inhibition of epidermal cell proliferation. In the present study, we observed the effect of salmeterol, a long-acting β2-AR agonist, on the proliferation and apoptosis of keratinocytes as well as imiquimod-induced psoriasis-like skin lesions in mice. As phosphodiesterase 4 (PDE4) inhibitors increases intracellular cAMP concentration by inhibiting its inactivation, we further explored the synergetic effect of a PDE4 inhibitor and salmeterol on psoriasis-like skin lesions in mice. Our results indicated that salmeterol effectively inhibited the proliferation of HaCaT cells induced by TNF-α and serum, and this effect was accompanied by significantly increased apoptosis and CREB phosphorylation, which were reversed by the PKA inhibitor, H89. Salmeterol ameliorated imiquimod-induced psoriasis-like skin lesions in mice, but salmeterol combined with a PDE4 inhibitor had no synergetic effect in improving skin lesions in mice. Of note, the synergistic effects of anti-proliferation and induction of apoptosis in HaCaT cells appeared by inhibiting ERK signaling. In summary, salmeterol, a long-acting β2-AR agonist, alleviates the severity of psoriasis via inhibiting the proliferation and promoting apoptosis of keratinocytes, partially by activating the cAMP/PKA signaling pathway.

Dihydroartemisinin Alleviates Imiquimod-Induced Psoriasis-like Skin Lesion in Mice Involving Modulation of IL-23/Th17 Axis.

Background: Psoriasis is a T help 17 (Th17) cell-mediated chronic inflammatory skin disease. Recent studies have shown that dihydroartemisinin (DHA) can significantly reduce experimental autoimmune encephalomyelitis and rheumatoid arthritis by regulating Th17 cells.Objective: To verify whether DHA can improve the symptoms of psoriasis and to further explore the possible mechanism.Methods: The efficiency of DHA was preliminary detected on human keratinocytes (HaCaT) cells in psoriatic condition. Then, imiquimod-induced psoriasis-like model in BALB/c mice was established to evaluate the effects of DHA in vivo.Results: Under the stimulation of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), DHA inhibited the proliferation of HaCaT cells and significantly affected the mRNA expression levels of IFN-γ, interleukin (IL), IL-17A and IL-23. DHA treatment reduced the severity of psoriasis-like skin and resulted in less infiltration of immune cells in skin lesions. DHA restored the expression of IFN-γ, IL-17A, and IL-23 in skins, as well as a decrease of cytokines and chemokines in skin supernatant. DHA also altered the cellular composition in the spleen, which is the makeup of the T cells, dendritic cells (DCs), and macrophages. DHA recovered Th17-related profile with decreased frequency of IL-17+CD4+T cells from splenocyte of mice. Furthermore, DHA also inhibited the concentration of IL-17 from Th17 cells and the expression of Th17 cell-related transcription factors retinoid-related orphan receptor-gamma t (ROR-γt) in vitro. In addition, phosphorylation of signal transducer and activator of transcription-3 (STAT3) was significantly reduced in DHA treatment mice, suggesting that the IL-23/Th17 axis plays a pivotal role.Conclusion: DHA inhibits the progression of psoriasis by regulating IL-23/Th17 axis and is expected to be an effective drug for the treatment of psoriasis.

Anti-Psoriatic Effects of Middle Fragment of Chlamydial Plasmid-Encoded Protein pGP3 in an Imiquimod-Induced Psoriasis Mouse Model.

BackgroundPreviously, we demonstrated that the chlamydial protein pGP3 forms a stable complex with LL-37 to neutralize its proinflammatory activity during the pathogenesis of psoriasis. The middle domain of pGP3 (pGP3M) is critical for the binding and neutralization of LL-37. Here, we further examined the mechanism underlying pGP3-mediated inhibition of psoriasis progression and evaluated the inhibitory effect of pGP3M on the development of psoriasis-like skin lesions in mice.Material/MethodsStock solutions of pGP3M and pGP3 (100 μg/mL) were prepared using sterile ultrapure water and intramuscularly injected into the left leg of the imiquimod (IMQ)-induced psoriasis mouse model. The severity of skin lesions was evaluated based on the psoriasis area and severity index score and ear skin thickness. The skin biopsy and blood samples were collected on the 8th day for histological analysis and inflammatory cytokines detection.ResultsErythema, scaling, and thickening were observed on the dorsal skin and the right ear skin of IMQ-treated mice. Treatment with pGP3 and pGP3M alleviated the IMQ-induced erythema, inflammatory cell infiltration, and scaly plaques. Compared with IMQ-treated and PBS-treated mice, pGP3- and PGP3M-treated mice had less inflammatory cell infiltration in skin tissues and had significantly reduced IL-17A, IFN-γ, and IL-22 levels in serum.ConclusionsThe anti-psoriatic efficacy of exogenous pGP3M was similar to that of pGP3. This indicated that pGP3M attenuated the IMQ-induced inflammatory and psoriatic symptoms in mice by binding and inhibiting LL-37. Further research is needed to examine the toxicity of pGP3 and pGP3M before clinical trial evaluation.

Daphnetin inhibits proliferation and inflammatory response in human HaCaT keratinocytes and ameliorates imiquimod-induced psoriasis-like skin lesion in mice

BackgroundPsoriasis is a common chronic inflammatory skin disease. Keratinocytes hyperproliferation and excessive inflammatory response contribute to psoriasis pathogenesis. The agents able to attenuate keratinocytes hyperproliferation and excessive inflammatory response are considered to be potentially useful for psoriasis treatment. Daphnetin exhibits broad bioactivities including anti-proliferation and anti-inflammatory. This study aims to evaluate the anti-psoriatic potential of daphnetin in vitro and in vivo, and explore underlying mechanisms.MethodsHaCaT keratinocytes was stimulated with the mixture of IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) to establish psoriatic keratinocyte model in vitro. Cell viability was measured using Cell Counting Kit-8 (CCK-8). Quantitative Real-Time PCR (qRT-PCR) was performed to measure the mRNA levels of hyperproliferative marker gene keratin 6 (KRT6), differentiation marker gene keratin 1 (KRT1) and inflammatory factors IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. Western blotting was used to detect the protein levels of p65 and p-p65. Indirect immunofluorescence assay (IFA) was carried out to detect p65 nuclear translocation. Imiquimod (IMQ) was used to construct psoriasis-like mouse model. Psoriasis severity (erythema, scaling) was scored based on Psoriasis Area Severity Index (PASI). Hematoxylin and eosin (H&E) staining was performed to examine histological change in skin lesion. The expression of inflammatory factors including IL-6, TNF-α, IL-23A and IL-17A in skin lesion was measured by qRT-PCR.ResultsDaphnetin attenuated M5-induced hyperproliferation in HaCaT keratinocytes. M5 stimulation significantly upregulated mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. However, daphnetin treatment partially attenuated the upregulation of those inflammatory cytokines. Daphnetin was found to be able to inhibit p65 phosphorylation and nuclear translocation in HaCaT keratinocytes. In addition, daphnetin significantly ameliorate the severity of skin lesion (erythema, scaling and epidermal thickness, inflammatory cell infiltration) in IMQ-induced psoriasis-like mouse model. Daphnetin treatment attenuated IMQ-induced upregulation of inflammatory cytokines including IL-6, IL-23A and IL-17A in skin lesion of mice.ConclusionsDaphnetin was able to attenuate proliferation and inflammatory response induced by M5 in HaCaT keratinocytes through suppression of NF-κB signaling pathway. Daphnetin could ameliorate the severity of skin lesion and improve inflammation status in IMQ-induced psoriasis-like mouse model. Daphnetin could be an attractive candidate for future development as an anti-psoriatic agent.

18\u03b2-Glycyrrhetinic acid induces human HaCaT keratinocytes apoptosis through ROS-mediated PI3K-Akt signaling pathway and ameliorates IMQ-induced psoriasis-like skin lesions in mice

BackgroundPsoriasis is a chronic inflammatory skin disease affecting 2–3% of the population worldwide. Hyperproliferative keratinocytes were thought to be an amplifier of inflammatory response, thereby sustaining persistence of psoriasis lesions. Agents with the ability to inhibit keratinocyte proliferation or induce apoptosis are potentially useful for psoriasis treatment. 18β-Glycyrrhetinic acid (GA), an active metabolite of glycyrrhizin, exhibits diverse pharmacological activities, including anti-inflammatory, anti-bacteria and anti-proliferation. The current study aims to evaluate the effects of GA on the proliferation and apoptosis of human HaCaT keratinocytes in vitro and investigate the effects of GA on the skin lesions of imiquimod (IMQ)-induced psoriasis-like mouse model in vivo.MethodsCell viability was assayed by CCK-8. Flow cytometry was performed to measure apoptosis and reactive oxygen species (ROS), with Annexin V-FITC/PI detection kit and DCFH-DA probe respectively. Caspase 9/3 activities were measured using caspase activity assay kits. The protein levels of Akt and p-Akt were determined using Western blotting. IMQ was applied to induce psoriasis-like skin lesions in mice. The histological change in mouse skin lesions was detected using hematoxylin and eosin (H&E) staining. The severity of skin lesions was scored based on Psoriasis Area Severity Index (PASI). RT-PCR was employed to examine the relative expression of TNF-α, IL-22 and IL-17A in mouse skin lesions.ResultsGA decreased HaCaT keratinocytes viability and induced cell apoptosis in a dose-dependent manner. In the presence of GA, intracellular ROS levels were significantly elevated. NAC, a ROS inhibitor, attenuated GA-mediated HaCaT keratinocytes growth inhibition and apoptosis. In addition, GA treatment remarkably decreased p-Akt protein level, which could be restored partially when cells were co-treated with GA and NAC. LY294002 (a PI3K inhibitor) treatment significantly enhanced GA-mediated cytotoxicity. Moreover, GA ameliorated IMQ-induced psoriasis-like skin lesions in mice.ConclusionsGA inhibits proliferation and induces apoptosis in HaCaT keratinocytes through ROS-mediated inhibition of PI3K-Akt signaling pathway, and ameliorates IMQ-induced psoriasis-like skin lesions in mice.

Chrysin alleviates imiquimod-induced psoriasis-like skin inflammation and reduces the release of CCL20 and antimicrobial peptides

Psoriasis is a common non-contagious chronic inflammatory skin lesion, with frequent recurrence. It mainly occurs due to aberrant regulation of the immune system leading to abnormal proliferation of skin cells. However, the pathogenic mechanisms of psoriasis are not fully understood. Although most of the current therapies are mostly efficient, the side effects can result in therapy stop, which makes the effectiveness of treatment strategies limited. Therefore, it is urgent and necessary to develop novel therapeutics. Here, we investigated the efficacy of chrysin, a plant flavonoid, which we previously reported to possess strong antioxidant and anti-inflammatory effects, against psoriasis-like inflammation. Our results revealed that chrysin significantly attenuated imiquimod-induced psoriasis-like skin lesions in mice, and improved imiquimod-induced disruption of skin barrier. Moreover, the TNF-α, IL-17A, and IL-22-induced phosphorylation of MAPK and JAK-STAT pathways, and activation of the NF-κB pathway were also attenuated by chrysin pretreatment of epidermal keratinocytes. Most importantly, chrysin reduced TNF-α-, IL-17A-, and IL-22-induced CCL20 and antimicrobial peptide release from epidermal keratinocytes. Thus, our findings indicate that chrysin may have therapeutic potential against inflammatory skin diseases. Our study provides a basis for further investigating chrysin as a novel pharmacologic agent and contributes to the academic advancement in the field of Chinese herbal medicine.

Three Constituents of Moringa oleifera Seeds Regulate Expression of Th17-Relevant Cytokines and Ameliorate TPA-Induced Psoriasis-Like Skin Lesions in Mice.

As a folk medicine, Moringa oleifera L. is used effectively to treat inflammatory conditions and skin diseases. However, its mechanism of action is not well understood, limiting its medical use. We isolated and identified three compounds, namely niazirin, marumoside A and sitosterol-3-O-β-d-glucoside, from the seeds of Moringa oleifera, and studied their effects on the expression of Th17-relevant cytokines (IL-12/IL-23 p40, IL-17A, IL-22 and IL-23 p19) using lipopolysaccharide-stimulated THP-1 cells. Additionally, as Th17 plays a critical role in the pathogenesis of psoriasis, we used a 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced psoriasis-like skin lesion mouse model to study their potential therapeutic application in vivo. The compounds suppressed the expression of IL-12/IL-23 p40, IL-17A, IL-22 and IL-23 p19 in vitro, and in vivo they ameliorated psoriasis-like skin lesions, decreased IL-17A mRNA expression, and increased the expression of keratinocyte differentiation markers. To our knowledge, this is the first report regarding the mechanism and therapeutic application of Moringa oleifera seeds to treat psoriasis-like lesions in vivo.

Ascorbic acid derivative DDH-1 ameliorates psoriasis-like skin lesions in mice by suppressing inflammatory cytokine expression

Psoriasis is a chronic inflammatory skin disease in which inflammatory cytokines play a major role in its pathogenesis. Because DDH-1, a novel amphipathic ascorbic acid derivative, has been recently shown to reduce inflammatory cytokine expression in human keratinocytes in vitro, we investigated its effect on imiquimod-induced psoriasis-like skin lesions in C57BL/6 mice. We first found that IL-1β and TNF-α mRNA expression was significantly decreased in the skin lesions treated with DDH-1. Furthermore, cutaneous administration of DDH-1 ameliorated psoriasis-like skin lesions. These results suggest that DDH-1 may be effective in the prevention and supplemental treatment of psoriasis.

Esculetin Ameliorates Psoriasis-Like Skin Disease in Mice by Inducing CD4+Foxp3+ Regulatory T Cells.

Psoriasis is an autoimmune and inflammatory skin disease affecting around 2–3% of the world's population. Patients with psoriasis need extensive treatments with global immunosuppressive agents that may cause severe side effects. Esculetin, a type of coumarins, is an active ingredient extracted mainly from the bark of Fraxinus rhynchophylla, which has been used to treat inflammatory and autoimmune diseases in China. However, the antipsoriatic effects of esculetin have not been reported. In this study, we aimed to investigate the effects of esculetin on psoriatic skin inflammation in a mouse model and explored the potential molecular mechanisms underlying its action. We found that esculetin ameliorated the skin lesion and reduced PASI scores as well as weight loss in imiquimod-induced psoriasis-like mice, accompanied with weakened proliferation and differentiation of keratinocytes and T cell infiltration in esculetin-treated psoriatic mice. In addition, esculetin reduced the frequency of CD8+CD44highCD62Llow effector T cells in psoriatic mice. In contrast, it increased the frequency of CD4+Foxp3+ Tregs in both lymph nodes and spleens of the psoriatic mice while promoting the differentiation of CD4+CD25− T cells into CD4+Foxp3+ Tregs in vitro. Interestingly, depleting CD4+Foxp3+ Tregs largely reversed esculetin-mediated reduction in PASI scores, indicating that esculetin attenuates murine psoriasis mainly by inducing CD4+Foxp3+ Tregs. Furthermore, the mRNA levels of proinflammatory cytokines in the psoriatic mouse skin, including IL-6, IL-17A, IL-22, IL-23, TNF-α, and IFN-γ, were dramatically decreased by the treatment with esculetin. Finally, we found that esculetin inhibited the phosphorylation of IKKα and P65 in the psoriatic skin, suggesting that it inhibits the activation of NF-κB signaling. Thus, we have demonstrated that esculetin attenuates psoriasis-like skin lesion in mice and may be a potential therapeutic candidate for the treatment of psoriasis in clinic.

Indirubin ameliorates imiquimod-induced psoriasis-like skin lesions in mice by inhibiting inflammatory responses mediated by IL-17A-producing γδ T cells

ObjectivesIndirubin (IR) is a bisindole compound extracted from the leaves of Chinese herb Indigo Naturalis. Indigo Naturalis has been widely used in traditional Chinese medicine to treat inflammatory and autoimmune diseases. Psoriasis is a chronic immune-mediated inflammatory skin disease in which γδ T cells play an important role. This study aims to determine the immunoregulatory effects and the underlying mechanisms of Indirubin in psoriasis-related inflammatory responses. MethodsBALB/c mice with imiquimod (IMQ)-induced psoriasis-like dermatitis were treated with saline (Model), 1 mg/kg methotrexate (MTX) that serves as a positive control, or 12.5, 25 and 50 mg/kg Indirubin(IR) intragastrically. Keratinocytes proliferation, inflammatory cells infiltration, the expression of inflammatory cytokines and Jak/Stat pathway-related proteins in the skin lesion were examined. The abundance of γδ T cells in lymph nodes and spleen was determined by flow cytometry. The IL-17 expression and secretion, and the activation of Jak3/Stat3 pathways in in vitro cultured γδ T cell were tested. ResultsIndirubin ameliorated keratinocyte proliferation, reduced the infiltration of CD3+ T cells, IL-17 A-producing γδ T cells, and CD11b+ neutrophils, inhibited the mRNA expression of Il1, Il6, Il23, Il17a and Il22, and the protein expression of Jak/Stat pathway-related molecules in the skin lesion. Indirubin also reduced the abundance of γδ T cell and CCR6+ γδ T cells (the major IL-17 A producer) in spleen and lymph nodes. In cultured γδ T cells, Indirubin inhibited the mRNA expression of Il17a and Ifng, and the secretion of IL-17 A, while suppressed the activation of Jak3/Stat3 pathways. ConclusionIndirubin alleviates IMQ-induced psoriasis-like dermatitis mainly through reducing the inflammatory responses mediated by IL-17 A-producing γδ T cells involving Jak3/Stat3 activation. Our results highlighted the novel mechanisms by which Indirubin ameliorates psoriasis-related inflammatory responses, supporting its therapeutic potential.

C10orf99 contributes to the development of psoriasis by promoting the proliferation of keratinocytes

Psoriasis is a chronic, relapsing inflammatory skin disease. The pathogenesis of psoriasis is complex and has not been fully understood. C10orf99 was a recently identified human antimicrobial peptide whose mRNA expression is elevated in psoriatic human skin samples. In this study, we investigated the functional roles of C10orf99 in epidermal proliferation under inflammatory condition. We showed that C10orf99 protein was significantly up-regulated in psoriatic skin samples from patients and the ortholog gene expression levels were up-regulated in imiquimod (IMQ)-induced psoriasis-like skin lesions in mice. Using M5-stimulated HaCaT cell line model of inflammation and a combinational approach of knockdown and overexpression of C10orf99, we demonstrated that C10orf99 could promote keratinocyte proliferation by facilitating the G1/S transition, and the pro-proliferation effect of C10orf99 was associated with the activation of the ERK1/2 and NF-κB but not the AKT pathways. Local depletion of C10orf99 by lentiviral vectors expressing C10orf99 shRNA effectively ameliorated IMQ-induced dermatitis. Taken together, these results indicate that C10orf99 plays a contributive role in psoriasis pathogenesis and may serve as a new target for psoriasis treatment.

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

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