Nintedanib ameliorates animal model of dermatitis

Abstract

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.

Figure 1

The expression levels of VEGFR1/FLT1 in animal model of dermatitis and dermatitis patients. (a) Relative expression levels of FLT1 in normal (n = 121) and dermatitis patients (n = 128). (b) mRNA expression of Flt1 was measured in oxazolone (OXA) treated mice ear and vehicle control (n = 15). (c) Histological analysis (H&E, Sirius red and toluidine blue staining) of control and oxazolone treated mice ear. Scale bar = 100 μm. (d) Immunofluorescent analysis of VEGFR1 from control and oxazolone treated mice ear. Scale bar = 100 μm. Data are presented as mean ± SEM and analyzed by student t-test. *p  <  0.05, **p  <  0.01 compared to control.

Figure 2

Morphological analysis of nintedanib-treated mice. (a) Schematic diagram of oxazolone (OXA)-induced animal model. Four groups: untreated controls, OXA only and mice treated with DEX (Dexamethasone) or nintedanib (NIN) one hour after every OXA challenge. (b) Representative photographs of mouse ears from each group on day 0 and 21. (c) Ear thickness was measured every week as indicated. Data are from three independent experiments (n = 15). Data are presented as mean  ±  SEM. Data (Day 21) are analyzed by student t-test. ***p  <  0.005 compared to oxazolone treated. (d) Ear weight was measured at day 21. Data are from three independent experiments (n = 15). Data are presented as mean  ±  SEM and analyzed by one-way ANOVA (****p < 0.001 compared to control, ^##p < 0.01, ^###p < 0.005 compared to oxazolone treated).

Figure 3

Histological analysis of nintedanib-treated mice. (a) H&E, sirius red and toluidine blue staining in ear lesions. Scale bar = 50 μm (b) Mean of epidermal thickness was measured using three different sections. (c) Mean of epidermal thickness was measured using three different sections. (d) Mean of mast cells (black arrow in toluidine blue staining) in dermis was measured. (e) Mean of eosinophil cells (red arrow in sirius red staining) in dermis was measured. (f) Serum IgE level was measured by ELISA at day 21. Data are from three independent experiments (n = 15). Data are presented as mean  ±  SEM of changes in values and analyzed by one-way ANOVA (**p < 0.01, ***p < 0.005, ****p < 0.001 compared to control, ^#p < 0.05, ^##p < 0.01, ^###p < 0.005, ^####p < 0.001 compared to oxazolone treated).

Figure 4

Expression of cytokines in nintedanib-treated mice. (a) mRNA levels of TNF-α from indicated mice ear. (b) mRNA levels of IL-β from indicated mice ear. (c) mRNA levels of IFN-γ from indicated mice ear. (d) mRNA levels of IL-4 from indicated mice ear. (e) mRNA levels of IL-5 from indicated mice ear. (f) mRNA levels of IL-6 from indicated mice ear. (g) mRNA levels of IL-10 from indicated mice ear. (h) mRNA levels of IL-13 from indicated mice ear. Data are from three independent experiments (n = 15). Data are presented as mean  ±  SEM and analyzed by one-way ANOVA (*p < 0.05, **p < 0.01, ***p < 0.005 versus control) and (^#p < 0.05, ^##p < 0.01 versus OXA).