Study On The Part Of Influencing Factors Of The Barrier Function Of Mouse Nasal Mucosa

Objective:Upper respiratory tract infection is a major infectious disease that threatens human health.The nasal mucosal barrier dysfunction is one of the important reasons for exterior pathogenic factors to invade the body.In order to explore the factors affecting the function of nasal mucosal barrier and to investigate the role of Yinqiao Powder,a representative prescription of cool-pungent exterior-releasing medicines,in preventing upper respiratory tract infection,the cold exposure and lipopolysaccharide nasal drip methods were used to mimic the factor as excessive cold exposure and inflammatory stimulation on the nasal mucosal barrier in mice.Methods:1.The effect of excessive cold exposure on mouse nasal mucosal immune barrier.Male KM mice were randomly divided into normal group and model group.All animals fasted for 12 h before modeling,and the normal group did not have any stimulation.In each model group,the animals were placed in-20 ? for 1h,then transferred to 25 ?for 30 min,circulated twice,and food and water were given in time after modeling.All animals were anesthetized and killed 24 hours after cold stimulation.The nasal mucosa tissue was carefully peeled under the microscope.Western blot was used to detect the protein expression of IgA and IFN-? in the nasal mucosa.2.The effect of excessive cold exposure on mouse nasal mucosal physical barrierMale KM mice were randomly divided into normal group and model group.All animals fasted for 12 h before modeling,and the normal group did not have any stimulation.In each model group,the animals were placed in-20 ? for 1h,then transferred to 25 ? for 30 min,circulated twice,and food and water were given in timeafter modeling.In the model group,animals were killed at 0 h,3 h,9 h,1 d,3 d and 5 d after cold stimulation.The nasal mucosa tissue was carefully peeled under the microscope.Western blot method was used to detect the protein expression of TJs related protein Occludin and Claudin 4 in the nasal mucosa.3.The effect of inflammation on the nasal mucosal barrier in miceMale KM mice were randomly divided into normal group and model group.All animals were fasted for 12 h before modeling.In the normal group,PBS(20 ?l / 20g)was dripped into nasal cavity slowly.In the model group,LPS(2mg / kg)was used as inflammatory inducer and dripped into nasal cavity slowly for once or five times respectively.After modeling,water and food were given normally.In the model group,animals were killed at each time point of anesthesia on the first day,the third day,the fifth day and the seventh day,respectively.The nasal mucosa tissues were carefully peeled off under the microscope.Western blot was used to detect the protein expression of IgA,Occludin,Claudin4 and Claudin5 in the nasal mucosa of mice.4.The effect of Yinqiao Powder on the nasal mucosal barrier of mice stimulated by LPSMale KM mice were randomly divided into normal group,model group,Yinqiao powder group.All the animals fasted for 12 h before modeling,the normal group dripped PBS(20 ?l / 20g)into nasal cavity slowly,the model group and Yinqiao Powder group dripped LPS(2mg / kg),once a day.The mice in Yinqiao group were given 24.28g/kg or72.54g/kg Yinqiao Powder by gavage 6 hours after LPS nasal drip stimulation.The mice in the normal group and the model group were given distilled water by gavage.At each time point on the 5th and 7th day,animals were anesthetized and killed.The nasal mucosa of the mice was carefully stripped under the microscope.Western blot was used to detect the expression of IgA and Occludin in the nasal mucosa of mice.Results:1.The effect of excessive cold exposure on mouse nasal mucosal immune barrier.The results showed that the expression of IgA and IFN-? protein in the nasal mucosa of the model group decreased significantly compared with the control group.It suggested that excessive cold exposure could decrease the nasal mucosal immune barrier of mouseunder our experimental conditions.2.The effect of excessive cold exposure on mouse nasal mucosal physical barrierThe results showed that there was little change in the expression of Occludin and Claudin4 protein in the nasal mucosa of the model group.It suggested that excessive cold exposure has little influence on the nasal mucosal physical barrier of mouse under our experimental conditions.3.The effect of inflammation on the nasal mucosal barrier in miceThe results showed that the expression of Occludin protein in the nasal mucosa of the model group was significantly decreased on the 3d,5d and 7d after LPS stimulation.It suggested that sustain inflammatory stimulation could decrease the nasal mucosal barrier of mouse.4.The effect of Yinqiao Powder on the nasal mucosa barrier of mice stimulated by LPSThe results showed that low and high doses of Yinqiao powder could increase the expression of Occludin protein in the nasal mucosa of mice stimulated by LPS.Conclusions:In this study,we found that excessive cold exposure decreases the nasal mucosal immune barrier of mouse through decreasing expression of IgA and IFN-? protein,but exerts little influence on the nasal mucosal physical barrier.Sustain inflammatory stimulation could decrease the nasal mucosal barrier of mouse.The expression of occludin in the physical barrier was decreased and the permeability of epithelial cells was increased.The effect of Yinqiao Powder on upper respiratory tract infection related to upregulating the expression of occlduin protein,reducing the permeability of epithelial barrier and promoting the expression of IgA protein.