Mechanism underlying the effect of combined therapy using glucosamine and low-dose cyclosporine A on the development of atopic dermatitis-like skin lesions in NC/Nga mice

Influence of pathogenic filaggrin variants on dupilumab treatment in atopic dermatitis

BACKGROUND

Pathogenic variants in filaggrin (FLG) are associated with an increased risk of atopic dermatitis (AD).

OBJECTIVE

We evaluated the influence of FLG variants on the effectiveness of dupilumab treatment in AD.

METHODS

This prospective observational study included adult AD patients treated with dupilumab from the BioDay registry. FLG was analyzed with single-molecule molecular inversion probe-targeted sequencing. Novel mutations were confirmed by Sanger sequencing. Eczema Area and Severity Index (EASI), Investigator Global Assessment (IGA), numeric rating scale (NRS) pruritus, Dermatology Quality of Life Index (DLQI), and Patient-Oriented Eczema Measure (POEM) were assessed at baseline and at weeks 16 and 52. The study was registered at ClinicalTrials.gov as NCT03549416.

RESULTS

Genetic analysis of the 285 included patients showed biallelic pathogenic variants (FLG-/-) in 41 (14%), monoallelic pathogenic variants (FLG-/+) in 64 (23%), and wild-type alleles (FLG+/+) in 180 patients (63%). Three novel pathogenic variants were found. We observed no clinically relevant differences in EASI, IGA, NRS pruritus, DLQI, or total POEM scores for patients with and without pathogenic FLG variants at all time points. The FLG-/- group showed significantly higher POEM flaking and dryness scores at week 16 (P < .001 and P = .002, respectively) and week 52 (P < .001 and P = .016, respectively) compared to FLG+/+ as well as significant differences compared to FLG-/+, while differences in delta scores were nonsignificant.

CONCLUSION

The effectiveness of dupilumab treatment in AD patients was not influenced by pathogenic FLG variants. However, patients with biallelic pathogenic FLG variants tended to have drier skin before and during dupilumab treatment compared to patients with monoallelic pathogenic variants or wild-type alleles.

Therapeutic effect of chinese herbal medicine gu-ben-hua-shi (AESS) formula on atopic dermatitis through regulation of yes-associated protein

Background: Atopic dermatitis (AD) is a chronic and recurrent skin disease. At present, there is a lack of sufficiently effective and safe medicines that can be used for a prolonged time and reduce the recurrence of AD. The Gu-Ben-Hua-Shi (AESS) formula has been used for many years with a good clinical effect on AD but its specific treatment mechanism is unknown.

Methods: The main components of AESS were analyzed using ultra-high performance liquid chromatography (UPLC). The composition of AESS compounds in the serum from rats was analyzed using ultra-high performance liquid chromatography-mass spectrometry. An AD mouse model was constructed using 2,4-dinitrofluorobenzene stimulation in Balb/C mice and the effect on the reduction of skin lesions and Th1/Th2/Th17/Treg balance after AESS administration were measured. The effects of AESS serum on the proliferation and apoptosis of keratinocyte cell line HaCaT and adhesion of HaCaT to human monocyte cell line THP-1 were detected in an IFN-γ/TNF-α stimulated AD-like inflammatory cell model. The effects of Yes-associated protein (YAP) expression on the therapeutic effect and a related signaling pathway were also investigated.

Results: In total, 10 components were confirmed using UPLC, namely five organic acids, three flavonoids, and two chromogenic ketones. Additionally, the similarity of the three batches of samples (S1–3) was above 0.98, indicating that the formula samples have good uniformity. These 10 compounds were also detected in rat serum, suggesting that they are absorbed into rat blood as prototype components. Furthermore, AESS effectively reduced the skin lesions in the AD mouse model, regulated the Th1/Th2/Th17/Treg imbalance, improved the proliferation ability of the AD-like cell model, and inhibited HaCaT apoptosis and adhesion to THP-1 cells. It also reduced the expression of YAP in Th17 and Treg cells of the mouse spleen and increased YAP expression in the skin. The change in YAP expression in keratinocytes weakened the curative effect of AESS, and AESS exerted its effects through the NF-κB signaling pathway.

Conclusion: AESS may play a role in the treatment of AD by affecting the expression of YAP. These findings can be used to promote its use as an alternative medication for prolonged use with fewer side effects.

Role of YAP-related T cell imbalance and epidermal keratinocyte dysfunction in the pathogenesis of atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is characterized by impaired skin barrier function and immune system dysfunction. The expression and role of Yes-associated protein (YAP) in AD are unclear.

OBJECTIVE

To characterize the role of the YAP in T cell imbalance and epidermal keratinocyte dysfunction in the pathogenesis of AD.

METHODS

We included 35 patients with AD (21 acute and 14 chronic). An AD mouse model was constructed using 2,4-dinitrofluorobenzene, and AD-like inflammatory cell model was constructed using TNF-α/IFN-γ-activated HaCaT cells. The proportion of Th1/Th2/Th17/Treg cells was detected using flow cytometry. After mononuclear cells were obtained from human peripheral blood or mouse spleen and induced to differentiate into different T cell subsets, YAP mRNA and protein expression were analyzed. Up-regulation of YAP was induced by lentivirus and down-regulation of YAP was induced by its specific inhibitor verteporfin (VP). The expression of YAP in skin lesions and infiltrating T cell subsets was detected using immunohistochemistry and double immunofluorescence staining, respectively.

RESULTS

We found differing degrees of Th1/Th2/Th17/Treg imbalance in acute and chronic AD. YAP expression was downregulated in Treg cells and upregulated in Th17 cells; YAP expression was downregulated in the AD epidermis. After YAP overexpression, the proportion of both Th17 and the Treg cells differentiated from mouse spleen mononuclear cells increased. There was an opposite trend after YAP inhibition. The proliferation and migration decreased and apoptosis increased after YAP inhibition in HaCaT cells.

CONCLUSION

Change of YAP expression may cause T cell imbalance and hamper the healing of the epidermis in AD.

Glucosamine regulation of fibroblast growth factor 21 expression in liver and adipose tissues

Obesity is associated with metabolic disorders. Fibroblast growth factor 21 (FGF21) has been recognized as important in metabolism. Glucosamine (GLN) has been demonstrated to perform diverse beneficial functions. This study aimed to reveal whether and how GLN would modulate FGF21 production in relation to metabolism. With in vivo model of normal diet (ND) and high-fat diet (HFD) mice receiving GLN injection and in vitro model of mouse AML12 liver cells and differentiated 3T3L1 adipocytes challenged with GLN, GLN appeared to improve the glucose metabolism in HFD and ND mice and to elevate FGF21 protein expression in HFD liver and to increase both FGF21 protein and mRNA levels in WAT from HFD and ND mice and it also upregulated FGF21 expression in both AML12 and differentiated 3T3L1 cells. By using inhibitors against various signaling pathways, p38, Akt, NF-κB, and PKA appeared potentially involved in GLN-mediated FGF21 production in AML12 cells; GLN was able to mediate activation of NF-κB, p38 or PKA/CREB signaling. Our accumulated findings suggest that GLN may potentially improve the metabolic performance by inducing FGF21 production in liver and adipose tissues and such induction in liver cells may act in part due to GLN induction of the NF-κB, p38 and PKA pathways.

Therapeutic anti-psoriatic effects of myeloid-derived suppressor cells in combination with systemic tacrolimus (FK-506) in an imiquimod-induced mouse model of psoriasis

Although tacrolimus (FK-506) has been shown to be an effective monotherapy for psoriasis, it does not always work well. Currently, combination therapy is frequently used to manage psoriasis because clinical trials have shown it may provide additive or synergistic benefits and reduce risks of adverse effects. Myeloid-derived suppressor cells (MDSCs) have potent immunomodulatory and anti-inflammatory properties in autoimmune diseases. We previously reported that MDSCs had protective effects in a murine model of imiquimod (IMQ)-induced psoriasis. The present study was undertaken to investigate the systemic immunomodulatory and therapeutic efficacy effects of MDSC plus FK-506 in an IMQ-induced mouse model of psoriasis and to investigate the immunomodulatory mechanisms involved. Systemic MDSC plus FK-506 therapy was found to have a significant anti-psoriatic effect in the murine model, to reduce levels of pro-inflammatory cytokines Th1 cytokines (TNF-α and IFN-γ) and Th17 cytokines (IL-17A and IL-23) in serum and skin. However, treatment with MDSCs or FK-506 alone had little impact. Furthermore, the anti-psoriatic effects of MDSC plus FK-506 were associated with histopathological reductions in inflammatory infiltration, epidermal hyperplasia, and hyperkeratosis. In addition, this combined treatment also attenuated IMQ-induced splenomegaly, and increased the proportion of CD4⁺CD25⁺FoxP3⁺ regulatory T (Treg) cells and decreased the proportions of CD4⁺IFN-γ⁺ Th1 cells and CD4⁺IL-17⁺ Th17 cells in spleen. Taken together, our results show systemic combination therapy with MDSCs and FK-506 had a better therapeutic effect in our IMQ-induced psoriasis model than either agent alone, and suggest that this combinatorial therapy might be useful for the management of autoimmune skin diseases like psoriasis.

The Effects of Fabric Containing Chamaecyparis obtusa Essential Oil on Atopic Dermatitis-Like Lesions: A Functional Clothing Possibility

BACKGROUND

Essential oil derived from Chamaecyparis obtusa (EOCO) has been used as an alternative treatment for allergy-related diseases due to its immune-modulating characteristics. Clothing has the longest and most intense contact with human skin, and functional fabrics with intrinsic properties have been increasingly implemented in medical applications. Specially designed fabrics may support atopic dermatitis (AD) treatment. In this study, the effects of fabric containing EOCO on AD were investigated using an NC/Nga mouse model.

METHODS

The fabric was applied for 6 h per day for 14 days. The therapeutic effects were evaluated according to measurements of skin lesion severity (modified SCORAD score), transepidermal water loss (TEWL), serum IgE and inflammatory cytokine levels, lesion thickness measured after hematoxylin and eosin staining, and immunohistochemical and Western blot analysis for skin epidermal differentiation protein.

RESULTS

The EOCO group exhibited significantly reduced modified SCORAD score, TEWL, and serum IgE levels. Among the inflammatory cytokines analyzed, only the mean values of regulated on activation, normal T cell expressed and secreted were observed to be decreased compared with other control groups. The histological analysis of the skin also revealed that the EOCO group expressed reduced epidermal hyperplasia and recovered filaggrin, involucrin, and loricrin expression.

CONCLUSIONS

It was confirmed that fabric containing EOCO has anti-atopic and anti-inflammatory properties. The study data show that fabric containing EOCO can be implemented as an alternative functional clothing for people suffering from AD.

Effects of Pelargonium sidoides and Coptis Rhizoma 2 : 1 Mixed Formula (PS + CR) on Ovalbumin-Induced Asthma in Mice

Pelargonium sidoides (PS) is traditionally used to treat respiratory and gastrointestinal infections, dysmenorrhea, and hepatic disorders in South Africa. Coptis Rhizoma (CR) is used to treat gastroenteric disorders, cardiovascular diseases, and cancer in East Asia. In the present study, we intended to observe the possible beneficial antiasthma effects of PS and CR on the ovalbumin- (OVA-) induced asthma C57BL/6J mice. Asthma in mice was induced by OVA sensitization and subsequent boosting. PS + CR (300 and 1,000 mg/kg; PO) or dexamethasone (IP) was administered once a day for 16 days. The changes in the body weight and gains, lung weights and gross inspections, total and differential cell counts of leukocytes in bronchoalveolar lavage fluid (BALF), serum OVA-specific immunoglobulin E (OVA-sIgE) levels, interleukin-4 (IL-4) and IL-5 levels in BALF and lung tissue homogenate, and IL-4 and IL-5 mRNA levels in lung tissue homogenates were analyzed with lung histopathology: mean alveolar surface area (ASA), alveolar septal thickness, numbers of inflammatory cells, mast cells, and eosinophils infiltrated in the alveolar regions, respectively. Significant increases in lung weights, total and differential cell counts of leukocytes in BALF, serum OVA-sIgE levels, and IL-4 and IL-5 levels in BALF and lung tissue homogenate were observed in OVA control as compared to those of intact control. In addition, OVA control showed a significant decrease in mean ASA and increases in alveolar septal thickness, numbers of inflammatory cells, mast cells, and eosinophils infiltrated in alveolar regions. However, these allergic and inflammatory asthmatic changes were significantly inhibited by PS + CR in a dose-dependent manner. In this study, PS + CR showed dose-dependent beneficial effects on OVA-induced asthma in mice through anti-inflammatory and antiallergic activities. Therefore, it is expected that PS + CR have enough potential as a new therapeutic agent or as an ingredient of a medicinal agent for various allergic and inflammatory respiratory diseases including asthma.

Gardenia jasminoides extract without crocin improved atopic dermatitis-like skin lesions via suppression of Th2-related cytokines in Dfe-induced NC/Nga mice

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD) is a pruritic, chronic, relapsing inflammatory skin disease. Gardenia jasminoides extract (GJE) has been used as a traditional remedy for the treatment of various inflammatory diseases, including AD. The specific effects of the extract components, which include crocin, geniposidic acid, and gardenoside, on inflammatory responses in AD are not entirely clear.

AIM OF THE STUDY

We determined the effects of G. jasminoides extract with crocin removed (GJE-C) on AD-like skin lesions in Dermatophagoies farina crude extract (Dfe)-treated NC/Nga mice, a well-known AD mouse model.

MATERIALS AND METHODS

To prepare the mice, 150 μl of 4% sodium dodecyl sulfate (SDS) was applied to the shaved dorsal skin or ear of NC/Nga mice 1 h before application of 100 mg Dfe. After 7 d, GJE-C was applied every day for 14 d. We performed behavior, histological, ELISA, assays to evaluate chemokines, cytokines, and skin barrier proteins in skin or serum samples from treated and untreated NC/Nga mice.

RESULTS

Topical application of GJE-C improved the severity scores of the AD-like skin lesions, frequency of scratching, and ear swelling in Dfe-treated NC/Nga mice similar to the complete GJE. In addition, GJE-C also reduced serum IgE and chemokine levels as well as the inflammatory response. Topical application of GJE-C also resulted in decreased infiltration of inflammatory cells, such as mast cells, via reduction of Th2 inflammatory mediators, including interleukin (IL)-4, IL-5, and IL-13, pro-inflammatory cytokines, and chemokines, and increased skin barrier protein expression in Dfe-treated NC/Nga mice. The GJE components geniposidic acid and gardenoside inhibited the production of atopic-related chemokines in HaCaT cells, but inclusion of crocin dampened this inhibition of chemokine production.

CONCLUSIONS

Together, these findings indicate that GJE-C may improve AD-like lesions by inhibiting the Th2 inflammatory response and expression of chemokines while increasing the expression of skin barrier proteins. These data provide experimental evidence that GJE-C may harbor therapeutic potential for AD.

Biodegradable Chitosan Decreases the Immune Response to Trichinella spiralis in Mice

The purpose of this study was to evaluate the potential of chitosan units released during natural degradation of the polymer to activate the immune system against T. spiralis infection. High molecular weight chitosan was injected intraperitoneally into C57BL/6 mice. Flow cytometry and cytokine concentration, measured by ELISA, were used to characterize peritoneal cell populations during T. spiralis infection. The strong chemo-attractive properties of chitosan caused considerable infiltration into the peritoneal cavity of CD11b⁺ cells, with reduced expression of MHC class II, CD80, CD86, Dectin-1 or CD23 receptors in comparison to T. spiralis-infected mice. After prolonged chitosan biodegradation, cell populations expressing IL-4R, MR and Dectin-1 receptors were found to coexist with elevated IL-6, IL-10, TGF-β and IgA production. IgA cross-reacted with T. spiralis antigen and chitosan. It was found that chitosan treatment attracted immune cells with low activity, which resulted in the number of nematodes increasing. The glucosamine and N-acetyl-D-glucosamine residues were recognized by wheat germ agglutinin (WGA) lectin and therefore any biodegradable chitosan units may actively downregulate the immune response to the parasite. The findings are relevant for both people and animals treated with chitosan preparations.

Glucosamine has an antiallergic effect in mice with allergic asthma and rhinitis

BACKGROUND

Glucosamine (GlcN) is generally used as a dietary supplement because of its antiinflammatory effects. We evaluated the antiallergic effect of GlcN in mice with allergic asthma and rhinitis.

METHODS

Thirty-two mice were allocated equally into 4 groups (n = 8). In group A (control), we performed intraperitoneal/intranasal challenge using sterile saline. In group B (asthma/rhinitis), we used ovalbumin for intraperitoneal/intranasal challenge to induce allergic asthma and rhinitis. In groups C and D (GlcN treatment), mice were given 1% and 5% GlcN throughout the period of ovalbumin challenge, respectively. We measured serum total and ovalbumin-specific immunoglobulin E (IgE), cytokine titers (interleukin-1, -4, -5, -6, -10, and -17; tumor necrosis factor-α; and interferon-γ), and the number of inflammatory cells (eosinophils, neutrophils, lymphocytes) in bronchoalveolar lavage (BAL) fluid. We also performed histopathologic examination of the lung and nasal cavity. Finally, we performed real-time polymerase chain reaction for the genes Bcl-2, EC-SOD, VEGF, caspase-3, Bax, COX-2, Hif-1α, and heme oxygenase-1.

RESULTS

Compared with group B, group D had significant serum total and ovalbumin-specific IgE decreases after GlcN treatment (p < 0.05). Titers for IL-4, IL-5, IL-6, and IL-17 in BAL fluid were significantly decreased in group D (p < 0.05). Eosinophils in BAL fluid were significantly decreased in group D compared with group B (p < 0.05). Groups C and D showed significant improvement of inflammation compared with group B. Group D had significant downregulation of EC-SOD, Bax, Hif-1α, and heme oxygenase-1 compared with group B.

CONCLUSION

GlcN had a significant antiallergic effect in mice with allergic asthma and rhinitis.

Interleukin-4 Downregulation of Involucrin Expression in Human Epidermal Keratinocytes Involves Stat6 Sequestration of the Coactivator CREB-Binding Protein

Skin barrier defects play an important role in atopic dermatitis (AD). Involucrin, an important barrier protein suppressed in human AD, is downregulated by interleukin-4 (IL-4). However, the molecular mechanism for IL-4 downregulation of involucrin has not been delineated, and especially how Stat6, a transcriptional activator, represses involucrin expression is unknown. Since Stats usually recruit p300/CBP in the general transcription machinery of their target genes and involucrin expression also involves p300/CBP, we hypothesize that Stat6 activated by IL-4 may sequestrate p300/CBP from the involucrin transcription complex, thus suppressing involucrin expression in keratinocytes. Using IL-4 transgenic mice, an AD mouse model, we find that involucrin expression is similarly downregulated as in human AD. In HaCat cells, the Jak inhibitor and dominant negative studies indicate that the Jaks-Stat6 pathway is involved in IL-4 downregulation of involucrin. Next, we transfected HaCat cells with an involucrin promoter-luciferase construct and then treated them with IL-4. IL-4 greatly suppresses the promoter activity, which is totally abolished by cotransfecting the CREB-binding protein (CBP) expression vector, indicating that IL-4 cannot downregulate involucrin in the presence of excess CBP. Finally, chromatin immunoprecipitation assay demonstrates that IL-4 decreases CBP binding to the involucrin transcription complex. For the first time, we defined a molecular mechanism for IL-4 downregulation of involucrin in keratinocytes, which may play an important role in the pathogenesis of AD.

Effects of low-dose light-emitting-diode therapy in combination with water bath for atopic dermatitis in NC/Nga mice

BACKGROUND

Light-emitting diode (LED) phototherapy and water bath therapy have beneficial effect on atopic dermatitis (AD)-like skin disease. However, not all current treatments work well and alternative therapies are need. The contribution of combination therapy with low-dose 850 nm LED and water bath was investigated on dermatophagoides farina (Df)-induced dermatitis in NC/Nga mice.

METHODS

Low-dose LED (10, 15, and 20 J/cm(2) ) irradiation, water bath (36 ± 1°C) were administered separately and together to the Df-induced NC/Nga mice in acrylic jar once a day for 2 weeks.

RESULTS

Combined therapy with low-dose LED therapy and water bath therapy significantly ameliorated the development of AD-like skin lesions. These effects were correlated with the suppression of total IgE, NO, histamine, and Th2-mediated immune responses. Furthermore, combination therapy significantly reduced the infiltration of inflammatory cells and the induction of thymic stromal lymphopoietin (TSLP) in the skin lesions. The beneficial therapeutic effects of this combination therapy might regulate by the inhibition of various immunological responses including Th2-mediated immune responses, inflammatory mediators such as IgE, histamine, and NO, as well as inflammatory cells.

CONCLUSIONS

The combination therapy of LED and water bath might be used as an efficacious, safe, and steroid-free alternative therapeutic strategy for the treatment of AD.

Therapeutic and immunomodulatory effects of glucosamine in combination with low-dose cyclosporine a in a murine model of imiquimod-induced psoriasis

Although cyclosporine A (CsA) is a potent immunomodulating agent and is commonly used as a systemic agent for the management of psoriasis patients, current clinical treatments are not always effective due to the clinical inefficacy of low-doses and numerous harmful effects of higher doses. Currently, the combined use of two other systemic drugs often has better therapeutic efficacy and is safer than low or high dose of a single drug. Glucosamine (Glu) also has immunomodulatory properties for autoimmune diseases. The aims of our study were to investigate the therapeutic efficacy of Glu in combination with low-dose CsA on imiquimod (IMQ)-induced psoriasis-like dermatitis in mice and to determine its immunomodulatory mechanism. We found that combined treatment with Glu (300 mg/kg) and low-dose (10 or 20mg/kg) CsA strongly ameliorated the development of psoriasis-like skin lesions and reduced the levels of Th1 cytokine (TNF-α) and Th17 cytokines (IL-17, IL-22, and IL-23) in the serum and dorsal skin. Histological findings also showed that the thickening of epidermis, stratum corneum, and inflammatory cell infiltration. Particularly, these combined treatments increased the number of CD4(+)CD25(+) regulatory T (Treg) cells in splenic. These results suggest that use of a combination of each drug might be used as an efficacious and safe alternative therapeutic strategy, as well as may provide an immunomodulatory approach for T cell-mediated autoimmune diseases, including psoriasis.

Oral administration of poly-γ-glutamate ameliorates atopic dermatitis in Nc/Nga mice by suppressing Th2-biased immune response and production of IL-17A

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is closely related to dysregulation of the T helper type 1 and 2 (Th1)/Th2 balance. A previous study showed that high molecular mass poly-γ-glutamate (γ-PGA) isolated from Bacillus subtilis sp. Chungkookjang induces the production of IL-12 from dendritic cells (DCs). Here, we investigated the effect of γ-PGA on AD-like skin disease using an Nc/Nga mouse model. In vitro, γ-PGA activated DCs and induced IL-12 production in mice. In vivo, oral administration of γ-PGA markedly reduced the AD symptoms, similar to the response seen in the dexamethasone (Dex)-treated group. Treatment with γ-PGA also decreased the serum levels of IgG1, the skin levels of Th2 cytokines, the extent of skin inflammation, and the accumulation of mast cells. Furthermore, γ-PGA was effective against established AD, significantly decreasing serum IgE and Th2 cytokines in the inflamed tissue. Interestingly, the production of IL-17A in splenocytes was also suppressed by γ-PGA, indicating that it inhibits both Th2 and Th17 immune responses. Collectively, these results suggest that oral administration of γ-PGA could be a therapeutic strategy for treating AD via the modulation of Th2-biased immune responses in an Nc/Nga mouse model.