Skin Lesions In Mice Research Articles

Primary Cutaneous Aspergillosis in a Patient with CARD9 Deficiency and Aspergillus Susceptibility of Card9 Knockout Mice.

We describe a case of primary cutaneous aspergillosis caused by Aspergillus fumigatus, and elucidate the underlying genetic and immunological mechanisms. Routine clinical and laboratory investigations were performed. Whole-exome sequencing of the patient's DNA suggested the presence of a CARD9 mutation, which was confirmed by Sanger sequencing. Innate and adaptive immunological responses of patient-derived CARD9-deficient cells were evaluated with ELISA and flow cytometry. Cutaneous and pulmonary aspergillosis models were established in Card9 knockout (KO) mice, which were compared with wild-type and immunosuppressed mice, to explore the pathogenesis and Aspergillus susceptibility. A 45-year-old man presented with a 37-year history of skin lesions on his face. A diagnosis of primary cutaneous aspergillosis was made through histopathology, immunohistochemistry, and tissue culture. Sanger sequencing of CARD9 showed a homozygous frame-shift mutation (c.819_820insG, p.D274fsX60), which led to the lack of CARD9 expression. Peripheral blood mononuclear cells from the patient showed selective impairment of proinflammatory cytokines, and Th1-, Th17-, and Th22-associated responses upon fungus-specific stimulation. The cutaneous aspergillosis model established in Card9 KO mice presented with persistent infection, with fungal germs and short hyphae in tissue, consistent with the patient's lesions. Skin lesions in immunosuppressed mice were more severe, and led to death. Unlike our patient, Card9 KO mice were relatively susceptible to pulmonary aspergillosis, with reasons to be investigated. This is, to our knowledge, the first report that links cutaneous aspergillosis to CARD9 mutation. This work enriches both the phenotypic spectrum of CARD9 deficiencies and the genetic background of cutaneous aspergillosis.

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.

Inhibitory Effects of a Sargassum miyabei Yendo on Cutibacterium acnes-Induced Skin Inflammation.

Acne vulgaris is a chronic inflammatory condition of skin sebaceous follicles. To explore its effects on acne vulgaris, we investigated the antibacterial and anti-inflammatory activities of Sargassum miyabei Yendo (a brown alga) ethanolic extract (SMYEE) on Cutibacterium acnes (C. acnes)-stimulated inflammatory responses, both in vivo and in vitro. To induce inflammation in vivo, C. acnes was intradermally injected into the dorsal skin of mice, to which SMYEE was applied. The antimicrobial activity of SMYEE was evaluated by the determination of minimum inhibitory concentrations (MICs). To explore in vitro anti-inflammatory effects, HaCaT cells were stimulated with C. acnes after treatment with SMYEE. The levels of IL-8 and the underlying molecular effects in C. acnes-stimulated HaCaT cells were assessed by enzyme-linked immunosorbent assay, Western blotting, and an electrophoretic mobility shift assay. Mouse skin lesions improved after treatment with SMYEE (50 μg/mouse). Neutrophil infiltration was significantly reduced in SMYEE-treated compared to SMYEE-untreated skin lesions. SMYEE reversed the C. acnes-induced increase in IL-8 levels in HaCaT cells and suppressed dHL-60 cell migration. SMYEE also inhibited C. acnes-induced phosphorylation of the extracellular signal-regulated kinase and inhibited activator protein-1 signaling. SMYEE may be a useful treatment for C. acnes-induced acne vulgaris.

Poly-γ-Glutamate microneedles as transdermal immunomodulators for ameliorating atopic dermatitis-like skin lesions in Nc/Nga mice

Atopic dermatitis (AD), a common, relapsing, inflammatory disorder of the skin, is associated with T helper type 2 (Th2)-biased immune responses. Despite the efficacy of existing drugs for AD treatment, their safety and side effects cause concern. The present study describes the use of dissolvable poly-γ-glutamate (γ-PGA) microneedles (MNs) with immunomodulatory effects for effectively relieving AD-like symptoms in Nc/Nga mice. γ-PGA MNs can easily penetrate the epidermis and release γ-PGA into the dendritic cell–rich dermis to interact with dendritic cells for modulating immune responses. Transdermal administration of high-molecular-weight (HMW, 1100 kDa) γ-PGA MNs significantly reduced clinical dermatitis scores, epidermal thickness, and mast cell infiltration in mice by downregulating immunoglobulin (Ig)E and IgG1 levels (Th2-associated antibodies) compared with the AD control group. However, low-molecular-weight (200–400 kDa) γ-PGA MNs ameliorated AD-like skin lesions less effectively than HMW γ-PGA MNs, thus indicating that the MW of γ-PGA may affect its immunomodulatory properties. Notably, the mouse skin quickly recovered its barrier function within 4 h after MN application. No weight loss or abnormality was observed in the MN-treated mice during the 8-week treatment period. These results suggest that the γ-PGA MNs represent an innovative, safe, and reliable therapeutic strategy for AD management. Statement of SignificanceThis study is the first to explore the feasibility of using poly-γ-glutamate (γ-PGA) microneedles (MNs) as transdermal immunomodulators for improving atopic dermatitis (AD) symptoms and to evaluate their immunomodulatory effect in mice with spontaneously developed AD. Transdermal administration of γ-PGA MNs enables the γ-PGA to localize in the skin for activation of dermal dendritic cells, thus modulating immune responses. We demonstrate that high-molecular-weight γ-PGA MNs can be retained in the skin for at least 6 days and effectively suppress AD-like skin lesions in mice by reducing infiltration of mast cells and downregulating Th2-associated antibody production (IgE and IgG1). The developed MN device has the potential to replace conventional therapy and to become an innovative treatment strategy for AD.

Effects of Electrospun Fibrous Membranes of PolyCaprolactone and Chitosan/Poly(Ethylene Oxide) on Mouse Acute Skin Lesions.

Polycaprolactone (PCL) is a synthetic polymer with good mechanical properties that are useful to produce biomaterials of clinical application. It can be successfully combined with chitosan, which enhances the biomaterial properties through the modulation of molecular and cellular mechanisms. The objective of this study was to evaluate the effects of the use of electrospun fibrous membranes consisting of polycaprolactone (PCL) or polycaprolactone coated with chitosan and poly(ethylene oxide) (PCL+CHI/PEO) on mouse skin lesions. Sixty four Black-57 mice were divided into PCL and PCL+CHI/PEO groups. A 1 cm2 lesion was made on the animals’ backs, and the membranes were sutured in place. The tissues were extracted on the 3rd, 7th, and 14th days after the lesion. The tissues were analyzed by histology with Hematoxylin and Eosin (H&E) and Sirius Red stains, morphometry, immunohistochemistry, and Western blot. On the 3rd, 6th, and 9th days after the lesion, the PCL+CHI/PEO group showed a higher wound-healing rate (WHR). On the 3 day, the PCL+CHI/PEO group showed a greater amount of inflammatory infiltrate, greater expression of proliferating cell nuclear antigen (PCNA), and smooth muscle actin (α-SMA) (p < 0.05) compared to the PCL group. On the 7th day after the lesion, the PCL+CHI/PEO group showed a greater amount of inflammatory infiltrate, expression of Tumor Necrosis Factor (TNF-α) and PCNA (p < 0.05). In addition, it showed a greater immunolabeling of Monocyte Chemoattractant Protein-1 (MCP-1) and deposition of collagen fibers compared to the PCL group. The PCL+CHI/PEO membrane modulated the increase in the inflammatory infiltrate, the expression of MCP-1, PCNA, and α-SMA in lesions of mice.

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.

Stress aggravates and prolongs imiquimod-induced psoriasis-like epidermal hyperplasis and IL-1β/IL-23p40 production.

Psoriasis is a common, chronic multifactorial inflammatory skin disease with both genetic and environmental components. A number of studies have suggested that psoriasis episodes are often preceded by stressful life events. Nevertheless, the underline mechanisms of stress in psoriasis remain unexplored. To address this question, we established an emotional stress mouse model induced by empty bottle stimulation, and applied imiquimod (IMQ), a ligand of TLR7/8 and effective potent immune activator, on the dorsal skin to induce psoriasis-like lesions. We found that empty bottles induced emotional stress exaggerated and prolonged psoriasiform dermatitis, which appeared as more prominent epidermal hyperplasia in the emotional stress mice compared with the control mice. Higher mRNA expression of Il-1β, Il-17a, and Il-22, as well as higher secretion of IL-1β, IL-12p40, IL-17, and IL-22 were observed in the skin lesion of emotional stress mice. The emotional stress condition and IMQ treatment synergistically led to higher expression levels of neurotransmitters and their receptors in the skin, especially substance P (SP), we also found that SP could stimulate DCs to secrete more IL-23p40 in vitro. In addition, NK-1R antagonist partially abrogated enhanced epidermal thickness and the level of neurotransmitters in emotional stress mice. Taken together, these results indicate that stress exacerbates and prolongs psoriasiform dermatitis in mice by up-regulating IL-1β and IL-23p40, which were related to local DCs stimulated by abnormal SP.

Conjugated linoleic acid attenuates 2,4-dinitrofluorobenzene-induced atopic dermatitis in mice through dual inhibition of COX-2/5-LOX and TLR4/NF-κB signaling

Conjugated linoleic acid (CLA), commonly found in beef, lamb and dairy products, has been reported to exhibit anti-inflammatory and antipruritus effects and to inhibit the release of chemical mediators such as histamine and eicosanoid in laboratory rodents. The chief objective of the study is to assess the efficacy of CLA on atopic dermatitis (AD) in mice and to explore possible mechanisms with CLA treatments. To develop a new therapy for AD, the anti-AD potential of CLA was investigated by inducing AD-like skin lesions in mice using 2,4-dinitrofluorobenzene. We evaluated dermatitis severity; histopathological changes; serum levels of T helper (Th) cytokines (interferon-γ, interleukin-4); changes in protein expression by western blotting and immunohistochemistry staining for cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), toll like receptor 4 (TLR-4), myeloid differentiation factor 88 (MyD88), nuclear factor-κB (NF-κB) and tumor necrosis factor α (TNF-α); and production of the proinflammatory lipid mediators, such as prostaglandin E2 and leukotriene B4, in the skin lesions. Treatment with CLA ameliorated the development of AD-like clinical symptoms and effectively inhibited epidermal hyperplasia and infiltration of mast cells and CD4+ T cells in the AD mouse skin. Total serum immunoglobulin E levels and the expression levels of Th1/Th2 cytokines and lipid mediators in dorsal skin were dramatically suppressed by CLA. Furthermore, CLA down-regulated the expressions of COX-2, 5-LOX, TLR4, MyD88, NF-κB and TNF-α. Taken together, our findings demonstrate the potential usefulness of CLA as an anti-inflammatory dietary supplement or drug for the prevention and management of AD skin diseases by modulating the COX-2/5-LOX and TLR4/MyD88/NF-κB signaling pathways.

Genomic characterization and pathogenicity analysis of the probiotic Vagococcus lutrae strain VL-18 causing severe skin lesions in warm-blooded animals

Vagococcus sp. has been recently used in aquaculture as a probiotic for gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax). However, the safety of this probiotic species remains largely unclear. In this study, V. lutrae strain VL-18, which caused a systematic skin lesion in a sea lion, was isolated from an aquarium in Dalian, China. Infection tests were performed to confirm its potential toxicity for European sea bass and mice. A chicken embryo chorioallantoic membrane (CAM) assay was conducted to validate the pathogenesis of this strain in chicken embryos. We further determined the complete genome of strain VL-18 by the PacBio RSII sequencing platform to understand its genetic basis as a potential pathogen. The results showed that V. lutrae strain VL-18 did not cause any noticeable tissue damage to European sea bass. However, intracutaneous injection of 1.8 × 108 CFU ml−1 V. lutrae strain VL-18, the LD50 value, caused severe skin lesions in mice. In addition, no mortality was observed for the mice after oral injection of strain VL-18, indicating that V. lutrae might infect mice via direct contact instead of oral administration. The chicken embryo CAM assay with 5 × 107 CFU ml−1 strain VL-18 caused 93.3% mortality of chicken embryos. Comparative genomic analysis of Vagococcus sp. revealed that the majority of Vagococcus sp. strains harboured multiple virulence factors, such as cytolysin, haemolysin, and serine protease, which resulted in potential pathogenesis in warm-blooded animals. This study confirmed that V. lutrae is an emerging zoonotic pathogen in warm-blooded animals. Therefore, the use of Vagococcus strains as probiotics should be immediately stopped. This is the first complete genome of Vagococcus lutrae. This study enhanced our understanding of the pathogenesis of a probiotic agent and underscored the safety assessment of probiotic strains, which are essential for the sustainable development of the aquaculture industry.

The Proteolytic Fraction From Vasconcellea cundinamarcensis Latex Displays Anti-Inflammatory Effect in A Mouse Model of Acute TNBS-Induced Colitis

The proteolytic fraction (P1G10) from Vasconcellea cundinamarcensis, displays gastric protective and healing activities in different skin lesions in mice and human. In an excisional model, this fraction accelerates resolution of lesions and modulates inflammatory mediators. Based on these data, we assessed its anti-inflammatory activity in murine colitis model, induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) adopted by its physiopathological similarity with human colitis. Twenty four hours after colitis induction followed by three days of treatment, P1G10 at 0.3 and 3.0 mg/Kg induced 30% increase in body weight (p < 0.0001) and ~80% reduction in colon macroscopic damage score (p < 0.05) compared to the untreated TNBS-induced colitis group. Histological analyses showed that 0.3 mg/Kg P1G10 reduced the inflammatory profile and tissue damage (47%, p < 0.05) when it was proteolytically active. Compared to TNBS group, 0.3 mg/Kg P1G10 reduced MPO activity (80%, p < 0.01), MCP-1 (47%, p < 0.05) and TNF-α (50%, no significant) and increased IL-10 (330%, p < 0.001) levels in the supernatant of colonic tissue homogenate. P1G10 treatment also reduced COX-2 expression (60%, p < 0.05) and metalloprotease-2 activity (39%, p < 0.05) while increased globet cell density (140%, p < 0.01), that contributes to mucus layer protection in colonic tissue. Taken together, these findings suggest that low doses of active P1G10 promotes lesion resolution, at least in part by its anti-inflammatory activity, in TNBS-colitis model.

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.

Suppression of DNCB-Induced Atopic Skin Lesions in Mice by Wikstroemia indica Extract

Wikstroemia indica (L.) C.A. Mey. is used in traditional Chinese medicine to treat inflammatory diseases such as arthritis and bronchitis. In this study, we aimed to investigate the effects of an ethanolic extract of W. indica on cutaneous inflammation in mice with 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD). Dermal administration of W. indica ethanolic extract to DNCB-sensitized hairless mice with dermatitis, for two weeks, reduced erythema, scaling, and edema. Skin hydration was improved and transepidermal water loss was reduced at a W. indica concentration of 1%. Furthermore, W. indica also significantly reduced serum IgE and IL-4 concentrations in our mouse model. These results suggest that W. indica has potential as a topical treatment for AD and as an adjunctive agent to control AD.

NCM 1921, a Mixture of Several Ingredients, Including Fatty Acids and Choline, Attenuates Atopic Dermatitis in 1-Chloro-2,4-Dinitrobenzene-Treated NC/Nga Mice.

Atopic dermatitis (AD) is a chronic inflammatory skin disease in humans. In this study, we evaluated the effects of a mixture (NCM 1921) of omega-3 butter, omega-3 beef tallow oil, omega-3 lard oil, caprylic acid, lauric acid, choline, and Fe on AD in 1-chloro-2,4-dinitrobenzene (DNCB)-treated NC/Nga mice. NCM 1921 significantly ameliorated the macroscopic and microscopic signs and reduced skin thickness and mast cell incorporation in the skin lesions of mice with DNCB-induced AD. Furthermore, it reduced serum immunoglobulin E levels; reduced the number of IgE-producing B cells, peripheral blood mononuclear cells, white blood cells, and differential white blood cells; and increased the number of lymphocytes. NCM 1921 normalized the total cell number in dorsal skin tissue, the axillary lymph node, and spleen following DNCB exposure and reduced the number of CD23+/B220+ cells in the axillary lymph node and CD3+ cells in dorsal skin tissue. Moreover, it reduced the levels of interleukin (IL)-4 and IL-13 but increased the levels of interferon-γ in anti-CD3–stimulated splenocytes. Immunohistofluorescence staining showed that NCM 1921 treatment significantly increased claudin1, filaggrin, and Sirt1 protein expressions in AD skin lesions. These results suggest that NCM 1921 could be a valuable remedy for the treatment of AD.

Liraglutide improved inflammation via mediating IL-23/Th-17 pathway in obese diabetic mice with psoriasiform skin

Objectives The purpose of this study was to investigate the effect of liraglutide on obesity diabetic mice with psoriasiform skin inflammation. Methods Wild-type mice and db/db mice were randomly divided into five groups (n = 6): including the control group which received Vaseline, the imiquimod (IMQ)-induction group and the liraglutide-treatment group. The advanced treatment with liraglutide (0.3 mg/kg/d) for 4 weeks before IMQ induced psoriatic skin inflammation in the db/db + IMQ + Lira group. Basic parameters of diabetes, PASI, histopathology of skin, the expression of IL-17A, IL-23, IL-22, and TNF-α in the skin of back were measured. Results After IMQ induction, the psoriatic skin inflammation and pathological changes in the db/db + IMQ group were more serious than those in the WT + IMQ group. The glucose metabolism and insulin resistance of in the db/db + IMQ + Lira group were significantly improved, Psoriasis Area and Severity Index (PASI) was significantly reduced, and the protein and mRNA expressions of IL-23, IL-17, IL-22, and TNF-α in the back skin tissues were decreased. Conclusions Liraglutide can improve psoriasis skin lesions of obese diabetic mice, and the mechanism may be related to the inhibition of the expression of IL-23, IL-17, IL-22, and TNF-α through the IL-23/Th-17 pathway.

Enzyme-treated date plum leave extract ameliorates atopic dermatitis-like skin lesion in hairless mice

Objective: To evaluate the effect of different extracts of Diospyros lotus leaves in atopic dermatitis Methods: Diospyros lotus leaves were extracted in ethanol and treated with or without hydrochloric acid or α-rhamnosidase to obtain three different extracts-ethanol, acid-hydrolyzed, and enzyme-hydrolyzed leaf extracts of date plum. The myricitrin content in all samples was measured using HPLC analysis. In vitro antioxidant and anti-inflammatory activities of the extracts were determined by measuring DPPH radical scavenging activities and nitric oxide production in RAW264.7 cells, respectively. Seven- week-old male hairless mice were used to evaluate the anti-atopic dermatitis effects of three extracts in vivo. Splenocytes and mast cells were used to further determine the anti-atopic dermatitis effects of the major compound in the ethanol leaf extract. Results: Enzyme-hydrolyzed leaf extract showed significant in vitro antioxidant and anti-inflammatory activities, and attenuated atopic dermatitis-like skin symptoms and clinical signs more significantly than ethanol and acid-hydrolyzed leaf extracts in 1-fluoro-2,4- dinitrobenzene and house dust mite antigen-treated hairless mice. Enzyme-hydrolyzed leaf extract also suppressed the serum level of immunoglobulin E, interleukin (IL)-4, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, thymic stromal lymphopoietin, and thymus and activation-regulated chemokine in mice with atopic dermatitis. Furthermore, histological analysis revealed that enzyme- hydrolyzed leaf extract suppressed the increased epidermal thickness, dermal infiltration of inflammatory cells, and infiltration and degranulation of mast cells more markedly than the other two extracts in atopic dermatitis-like skin lesions. In addition, this extract effectively inhibited the production of IFN-γ, IL-4,and thymus and activation-regulated chemokine compared with the other two extracts in concanavalin A-stimulated splenocytes. Myricitrin, a major compound of enzyme-hydrolyzed leaf extract, suppressed atopic dermatitis biomarkers in stimulated mouse splenocytes and HMC-1 human mast cells. Conclusions: These results suggest that enzyme-hydrolyzed leaf extract might be a potential candidate to treat atopic dermatitis.

Dihydroartemisinin ameliorates psoriatic skin inflammation and its relapse by diminishing CD8+ T-cell memory in wild-type and humanized mice.

Conventional immunosuppressants cause side effects and do not prevent the recurrence of autoimmune diseases. Moreover, they may not inhibit autoimmunity mediated by pathogenic memory T-cells. Dihydroartemisinin (DHA) has been shown to regulate autoimmunity. However, it remains unknown whether DHA impacts psoriasis and its recurrence. The objective of this study was to determine therapeutic effects of DHA on psoriasis and its relapse as well as its underlying mechanisms.Methods: We established animal models of imiquimod (IMQ)-induced psoriasis-like wild-type mice and humanized NSG mice receiving lesional human skin from patients with psoriasis. Many immunoassays, including immunohistochemistry, flow cytometry, quantitative RT-PCR and Western blotting, were performed.Results: We found that DHA not only ameliorated acute skin lesion of psoriatic mice, but also alleviated its recurrence by diminishing CD8+ central memory T (TCM) and CD8+ resident memory T (TRM) cells. It attenuated epidermal pathology and T-cell infiltration in the skin of IMQ-induced psoriatic mice while suppressing expression of IL-15, IL-17 and other proinflammatory cytokines in the skin. Surprisingly, DHA reduced the frequency and number of CD8+, but not CD4+, subset of CD44highCD62Lhigh TCM in psoriatic mice, whereas methotrexate (MTX) lowered CD4+, but not CD8+, TCM frequency and number. Indeed, DHA, but not MTX, downregulated eomesodermin (EOMES) and BCL-6 expression in CD8+ T-cells. Furthermore, DHA, but not MTX, reduced the presence of CD8+CLA+, CD8+CD69+ or CD8+CD103+ TRM cells in mouse skin. Interestingly, treatment with DHA, but not MTX, during the first onset of psoriasis largely prevented psoriasis relapse induced by low doses of IMQ two weeks later. Administration of recombinant IL-15 or CD8+, but not CD4+, TCM cells resulted in complete recurrence of psoriasis in mice previously treated with DHA. Finally, we demonstrated that DHA alleviated psoriatic human skin lesions in humanized NSG mice grafted with lesional skin from psoriatic patients while reducing human CD8+ TCM and CD103+ TRM cells in humanized mice.Conclusion: We have provided the first evidence that DHA is advantageous over MTX in preventing psoriasis relapse by reducing memory CD8+ T-cells.

Mechanism of danshensu-induced inhibition of abnormal epidermal proliferation in psoriasis

Psoriasis is a chronic, inflammatory skin disease with high incidence and high rates of relapse, for which no satisfactory treatments are currently available. Yes-associated protein (YAP) is highly expressed in psoriasis and may regulate the proliferation and apoptosis of keratinocytes. Danshen is a traditional Chinese medicine, commonly used in the treatment of psoriasis. Danshensu is the most abundant water-soluble component of Danshen, but its therapeutic mechanism is still unclear. In this study, MTT was used to detect the effects of different danshensu concentrations (0.125, 0.25, 0.5 mmol/l) on the proliferation of an M5-based psoriasis cell model. The effects of danshensu on cell cycle and apoptosis were detected by flow cytometry. Cyclins and apoptosis-related proteins were evaluated by Western blot. Danshensu (20, 40, 80 mg/kg/day) was administered intraperitoneally to the imiquimod (IMQ) psoriasis mouse model. After 7 days, the expression of YAP in the lesions was detected by immunohistochemistry and Western blot. We found that danshensu reduced the expression of YAP in the M5 psoriasis cell model, inhibited cell proliferation, induced cell cycle arrest in G0/G1 phase, and promoted cell apoptosis. All these effects were partly reverted by YAP overexpression. The skin lesions of IMQ mice were thinned and the scales reduced after intragastric administration of danshensu, which also resulted in dose-dependent inhibition of YAP expression. We concluded that danshensu prevents abnormal epidermis proliferation in psoriasis possibly by modulating YAP expression. Our work can provide a theoretical basis for the clinical application of Danshen in the treatment of psoriasis.

CD8+ T cells regulated by CD4+CD25+ regulatory T cells in the early stage exacerbate the development of Dermatophagoides farinae-induced skin lesions via increasing mast cell infiltration in mice

Atopic dermatitis is a chronic inflammatory skin disease associated with CD4+ Th2 cell-shifted immune responses. Although the infiltration of skin lesions by CD8+ T cells has been recognized, their roles have not been fully defined. In this study, we examined the relationship between CD4+ and CD8+ cells in antigen-induced skin lesions of mice. BALB/c mice were repeatedly challenged with Dermatophagoides farinae (Der f) applied to the right ear nine times. Pre-treatment with anti-CD4 monoclonal antibody (mAb) during the third to sixth challenges, but not the post-treatment during the sixth to ninth challenges, exacerbated the development of Der f-induced ear swelling; pre-treatment with anti-CD25 mAb, which depletes regulatory T cells (Tregs), also exacerbated the lesions. Furthermore, the number of CD8+ T cells in lymph nodes was augmented by these pre-treatments. These findings prompted us to examine the effect of anti-CD8 mAb. Pre-treatment with anti-CD8 mAb, but not post-treatment, strongly inhibited the development of Der f-induced ear swelling; additionally, the epidermal hyperplasia and infiltration of mast cells were inhibited by the pre-treatment. Collectively, we revealed that CD8+ T cells regulated by CD4+CD25+ Tregs in the early stage are key contributors to the development of Der f-induced skin lesions via increasing mast cell infiltration, indicating that CD8+ T and Tregs could be potential therapeutic targets for atopic dermatitis.

The human papillomavirus 16 E5 gene potentiates MmuPV1-Dependent pathogenesis

The papillomavirus E5 gene contributes to transformation and tumorigenesis; however, its exact function in these processes and viral pathogenesis is unclear. While E5 is present in high-risk mucosotropic HPVs that cause anogenital and head and neck cancers, it is absent in cutaneous HPVs and the recently discovered mouse papillomavirus (MmuPV1), which causes papillomas and squamous cell carcinomas of the skin and mucosal epithelia in laboratory mice. We infected K14E5 transgenic mice, which express the high-risk mucosotropic HPV16 E5 gene in stratified epithelia, with MmuPV1 to investigate the effects of E5 on papillomavirus-induced pathogenesis. Skin lesions in MmuPV1-infected K14E5 mice had earlier onset, higher incidence, and reduced frequency of spontaneous regression compared to those in non-transgenic mice. K14E5 mice were also more susceptible to cervicovaginal cancers when infected with MmuPV1 and treated with estrogen compared to non-transgenic mice. Our studies support the hypothesis that E5 contributes to papillomavirus-induced pathogenesis.

Development of a chitosan hydrogel containing flavonoids extracted from Passiflora edulis leaves and the evaluation of its antioxidant and wound healing properties for the treatment of skin lesions in diabetic mice.

This study aimed to develop a chitosan-based hydrogel containing a mixture of flavonoids isolated from the leaves of Passiflora edulis Sims and to evaluate its stability, antioxidant properties, and wound healing effects on cutaneous lesions in diabetic rats. in vitro studies were carried out to evaluate the biocompatibility and flavonoid release from the chitosan hydrogel. in vivo wound healing studies were conducted on male Wistar rats, where the injured tissue was removed for histological analysis and determination of lipid peroxidation, superoxide dismutase activity, and glutathione peroxidase activity. From the histological analysis and macroscopic evaluation of the contraction of the wounds, it was observed that the formulation presented wound healing properties. In addition, treatment of the wound with the formulation stimulated the antioxidant defense system, suggesting a beneficial effect during the treatment of skin lesions in diabetic rats, especially in the first few days after wounding. According to these results, we can conclude that the chitosan hydrogel containing the flavonoid analyzed in this study has potential use as dressings in the treatment of wounds.