Effects of vitamin D diet early in life on airway inflammation in different endotypes of asthma mice models / 中国医师进修杂志

ABSTRACT

Objective:To investigate the effects of different doses of vitamin D diet early in life on airway inflammation in different endotypes of asthma mice models.Methods:In the Animal House of Shanghai General Hospital of Nanjing Medical University in June 2022, the BALB/c mice with 14 d pregnant were selected, the offspring mice were divided into vitamin D sufficient group and vitamin D deficient group by random number table method with 12 each. The mice in the vitamin D sufficient group were given a feed with sufficient vitamin D content, while the mice in the vitamin D deficient group were given a feed without vitamin D. At the age of 8 weeks, the mice were sensitized and stimulated with ovalbumin to establish a T2 type asthma model, while the mice were sensitized and stimulated with ovalbumin combined with ozone exposure to establish a non-T2 type asthma model, with 6 mice in each model. The level of serum 25 hydroxy vitamin D 3 was detected by enzyme-linked immunosorbent assay (ELISA) method. The lung tissue was stained with HE to evaluate the inflammatory response score and calculate the eosinophils density and neutrophils density. In bronchoalveolar lavage fluid (BALF), the expression levels of interleukin (IL)-4, IL-6, IL-10 and IL-17A, the inflammatory cell count (total cell count, neutrophil count and eosinophil count) were detected. Results:The 25 hydroxy vitamin D 3 in T2 type asthma mice and non-T2 type asthma mice of vitamin D deficient group were significantly lower than that in vitamin D sufficient group (8.12 ± 1.72) μg/L vs. (26.63 ± 2.54) μg/L and (6.86 ± 1.65) μg/L vs. (23.81 ± 3.09) μg/L, and there was statistical difference ( P<0.01). The inflammatory response score in non-T2 type asthma mice of vitamin D deficient group was significantly higher than that in non-T2 type asthma mice of vitamin D sufficient group (2.58 ± 0.49) scores vs. (1.83 ± 0.21) scores, and there was statistical difference ( P<0.05), there was no statistical differences in inflammatory response score in T2 type asthma mice between two groups ( P>0.05). The neutrophils density and eosinophils density in T2 type asthma mice and non-T2 type asthma mice of vitamin D deficient group were significantly higher than those in vitamin D sufficient group, T2 type asthma mice (20.30 ± 1.95) cells/100 μm vs. (12.58 ± 1.04) cells/100 μm and (5.25 ± 0.62) cells/100 μm vs. (3.15 ± 0.35) cells/100 μm; non-T2 type asthma mice (53.48±5.19) cells/100 μm vs. (33.80 ± 2.74) cells/100 μm and (3.00 ± 0.29) cells/100 μm vs. (2.17 ± 0.21) cells/100 μm, and there were statistical differences ( P<0.01 or <0.05). The BALF total cell count in T2 type asthma mice and non-T2 type asthma mice of vitamin D deficient group was significantly higher than that in vitamin D sufficient group, the BALF eosinophil count in T2 type asthma mice of vitamin D deficient group was significantly higher than that in T2 type asthma mice of vitamin D sufficient group, the BALF neutrophil count in non-T2 type asthma mice of vitamin D deficient group was significantly higher than that in T2 type asthma mice of vitamin D sufficient group, and there were statistical differences ( P<0.01); there was no statistical difference in BALF neutrophil count in T2 type asthma mice between two groups ( P>0.05); there was no statistical difference in BALF eosinophil count in non-T2 type asthma mice between two groups ( P>0.05). The BALF total cell count and neutrophil count in non-T2 type asthma mice of both groups were significantly higher than those in T2 type asthma mice, but the BALF eosinophil count in T2 type asthma mice was significantly higher non-T2 type asthma mice, and there were statistical differences ( P<0.05). The BALF IL-4, IL-6 and IL-17A in T2 type asthma mice and non-T2 type asthma mice of vitamin D deficient group were significantly higher than those in vitamin D sufficient group, the BALF IL-10 was significantly lower than those in vitamin D sufficient group, and there were statistical differences ( P<0.01 or <0.05). In vitamin D deficient group, the BALF IL-4 in non-T2 type asthma mice was significantly lower than that in T2 type asthma mice, the BALF IL-6 and IL-17A were significantly higher than those in T2 type asthma mice, and there were statistical differences ( P<0.05); in vitamin D sufficient group, the BALF IL-6 and IL-17A in non-T2 type asthma mice were significantly higher than those in T2 type asthma mice, and there were statistical differences ( P<0.05). Conclusions:Vitamin D deficiency is involved in different mechanisms of airway inflammation in T2 type asthma and non-T2 type asthma, and this effect may be more obvious for non-T2 type asthma.