Metformin ameliorates animal models of dermatitis

Metformin, a potent AMPK activator is the most commonly used drug for diabetes. According to recent reports, metformin lowers the risk of diabetic complications and inflammatory diseases. We found the expression levels of AMPK subunits including PRKAA1, PRKAA2, PRKAB1 and PRKAB2 are decreased in skin biopsies of dermatitis patients from multiple datasets. Interestingly, metformin treatment ameliorates dermatitis symptom in animal model of dermatitis using O-tetradecanoylphorbol-13-acetate (TPA). Especially, the levels of epidermis and dermis thickness were decreased by metformin. We found NFκB activity as well as of gene expression associated with collagen synthesis are attenuated by metformin treatment. These results suggest that metformin treatment alleviates animal model of dermatitis.

Nintedanib ameliorates animal model of dermatitis

Nintedanib, a receptor tyrosine kinase (RTK) inhibitor has been developed as therapeutics for idiopathic pulmonary fibrosis and non-small lung cancer. We found that the expression levels of RTK, especially VEGFR1 is increased in skin biopsies of dermatitis patients from multiple independent datasets. Moreover, VEGFR1 is highly expressed by infiltrated cells in dermis from oxazolone (OXA) treated mice. Interestingly, nintedanib alleviates dermatitis symptom in OXA-induced animal model. Especially, levels of epidermis thickness, infiltrated immune cells including mast cells and eosinophils were decreased from mice cotreated with nintedanib and OXA compared with OXA treated mice. Moreover, serum IgE and Th2 cytokines including IL-4 and IL-13 were decreased by nintedanib treatment. These results suggest an evidence that nintedanib alleviates animal model of dermatitis.

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.

Antiallergic effects of anti-interleukin-33 are associated with suppression of immunoglobulin light chain and inducible nitric oxide synthase

OBJECTIVE

We aimed to find novel genes that are significantly induced in allergic mice and that are significantly downregulated with anti-interleukin (IL) 33 treatment.

METHODS

Thirty-six mice were allocated into each of group A (intraperitoneal [i.p.]) sensitized and intranasally challenged to saline solution), group B (sensitized and challenged to ovalbumin), group C (sensitized and challenged with ovalbumin, and null treatment with i.p. saline solution), and group D (sensitized and challenged with ovalbumin, and treatment with anti-IL-33 i.p. injection). We counted the number of nose-scratching in 10 minutes, serum ovalbumin-specific immunoglobulin E (IgE), and titers of cytokines (IL-1, IL-4, IL-5, IL-10, IL-13) in bronchoalveolar lavage fluid. By using one whole lung from each mouse, we performed microarray analysis and real-time polymerase chain reaction.

RESULTS

group D showed a significantly reduced nose-scratching events and lower serum ovalbumin-specific IgE compared with groups B and C. All the cytokines in the bronchoalveolar lavage fluid were significantly decreased after anti-IL-33 treatment. Microarray analysis revealed that group B (immunoglobulin free light chain [IgFLC], 89.1 times; nitric oxide synthase [NOS] 2, 11.5 times) and group C (IgFLC, 141.6 times; NOS2, 11.7 times) had significantly increased expression of IgFLC and NOS2 genes compared with group A. After anti-IL-33 treatment, group D showed significantly decreased expression of both IgFLC (49.3 times) and NOS2 (6.5 times). In real-time polymerase chain reaction, groups B and C had significantly increased expression of these genes (IgFLC, 10.4 times and 29 times, respectively; NOS2, 3.8 times and 4.5 times, respectively). After treatment, group D showed significantly decreased expression of IgFLC (5.0 times) and NOS2 (2.5 times).

CONCLUSION

The antiallergic effect of anti-IL-33 can be explained by suppression of IgFLC and NOS2 in a murine model of allergic rhinitis.

Prolonged Anti-Orthostatic Hind Limb Unloading and Murine Allergic Asthma

BACKGROUND

Hind limb unloading (HU) is one of the ground-based models of simulated microgravity. As bacterial and viral infections could affect the immune system, the immunologic effect of HU should be studied in a specific-pathogen-free (SPF) laboratory. However, a review of the literature did not reveal any studies on the immunologic effects of prolonged HU in a murine model of allergic disease. Accordingly, the present study was undertaken to evaluate the effect of HU in a murine model of allergic asthma in a SPF laboratory.

METHODS

Twenty BALB/c mice were allocated equally to Group A (control group), Group B (HU group), Group C (allergic group), or Group D (allergic + HU group). Weight gains, serum total and ovalbumin (OVA)-specific IgE, titers of IL-1, IL-5, IL-10, and IFN-γ in bronchoalveolar lavage (BAL) fluid, and histopathologic findings of the lungs were compared.

RESULTS

After 2 wk of HU, Group D showed significantly more weight loss (-2.0±0.2 g) than Group C (-1.1±0.4 g). Groups B and D showed significant increases in serum OVA-specific IgE as compared with Groups A and C. Group D had significantly lower titers of IL-5 (Group C: 53.0±15.2 pg·ml(-1), Group D: 21.9±13.9 pg·ml(-1)), IL-10 (Group C: 430.8±138.3 pg·ml(-1), Group D: 217.6±51.2 pg·ml(-1)), and IFN-γ (Group C: 104.3±37.5 pg·ml(-1), Group D: 36.7±12.8 pg·ml(-1)) in BAL fluid than Group C. Peri-bronchiolar and pulmonary infiltrations of inflammatory cells were significantly greater in Group D than in Group C.

CONCLUSIONS

Prolonged HU may cause significant weight loss and aggravate disease courses.

Benzaldehyde suppresses murine allergic asthma and rhinitis

To evaluate the antiallergic effects of oral benzaldehyde in a murine model of allergic asthma and rhinitis, we divided 20 female BALB/c mice aged 8-10 weeks into nonallergic (intraperitoneally sensitized and intranasally challenged to normal saline), allergic (intraperitoneally sensitized and intranasally challenged to ovalbumin), and 200- and 400-mg/kg benzaldehyde (allergic but treated) groups. The number of nose-scratching events in 10 min, levels of total and ovalbumin-specific IgE in serum, differential counts of inflammatory cells in bronchoalveolar lavage (BAL) fluid, titers of Th2 cytokines (IL-4, IL-5, IL-13) in BAL fluid, histopathologic findings of lung and nasal tissues, and expressions of proteins involved in apoptosis (Bcl-2, Bax, caspase-3), inflammation (COX-2), antioxidation (extracellular SOD, HO-1), and hypoxia (HIF-1α, VEGF) in lung tissue were evaluated. The treated mice had significantly fewer nose-scratching events, less inflammatory cell infiltration in lung and nasal tissues, and lower HIF-1α and VEGF expressions in lung tissue than the allergic group. The number of eosinophils and neutrophils and Th2 cytokine titers in BAL fluid significantly decreased after the treatment (P<0.05). These results imply that oral benzaldehyde exerts antiallergic effects in murine allergic asthma and rhinitis, possibly through inhibition of HIF-1α and VEGF.