Effect of vascular endothelial growth factor and its receptors in adult otitis media with effusion

Effect of Angiogenesis and Lymphangiogenesis in Diesel Exhaust Particles Inhalation in Mouse Model of LPS Induced Acute Otitis Media

Lymphangiogenesis and angiogenesis might have significant involvement in the pathogenesis of otitis media with effusion. This study investigated the effect of diesel exhaust particles (DEP) on inflammation and lymphangiogenesis in a mouse model of acute otitis media (AOM). BALB/c mice were injected with LPS and exposed to 100 µg/m³ DEP. The mice were divided into four groups: control (no stimulation), AOM, AOM + DEP, and DEP + AOM.

The effects of DEP inhalation pre- and post-DEP induction were estimated based on measurements of the auditory brainstem response, mRNA levels of lymphangiogenesis-related genes and cytokines, and histology of the middle ear. Cell viability of human middle ear epithelial cells decreased in a dose-response manner at 24 and 48 hours post-DEP exposure. DEP alone did not induce AOM. AOM-induced mice with pre- or post-DEP exposure showed thickened middle ear mucosa and increased expression of TNF-α and IL1-β mRNA levels compared to the control group, but increased serum IL-1β levels were not found in the AOM + Post DEP. The mRNA expression of TLR4, VEGFA, VEGFAC, and VEGFR3 was increased by pre-AOM DEP exposure.

The expression of VEFGA protein was stronger in the AOM + Post DEP group than in any other group. The expression of CD31 and CD45 markers in the mouse middle ear tissue was higher in the Pre DEP + AOM group than in the AOM group. This result implies that pre-exposure to DEP more strongly increases inflammation and lymphangiogenesis in a mouse model of acute otitis media.

[Clinical observation of chronic recurrent secretory otitis media in adults treated by balloon dilatation of Eustachian tube combined with myringotomy and catheterization]

Objective:To explore the clinical effect of balloon dilatation of the Eustachian tube combined with myringotomy and catheterization in treating chronic recurrent secretory otitis media in adults. Methods:100 cases（135 ears） of chronic recurrent secretory otitis media in our hospital from January 2018 to May 2020 were selected as the research objects, and were divided into two groups according to the random number table method, 50 cases（68 ears） in the control group and 50 cases（67ears） in the observation group. The control group received tympanostomy and catheterization, while the observation group received tympanostomy with catheterization and balloon dilatation of the Eustachian tube. The total effective rates, Eustachian tube dysfunction scores, Eustachian tube pressure R scores, pure tone thresholds, complication rates, scores of life quality and recurrence rates 1 year after operation were compared between the two groups. Results:The total effective rate was higher in the observation group than the control group（P<0.05）. Compared with pre-operation, the score of Eustachian tube dysfunction, the pure tone listening threshold of each frequency were lower and the Eustachian tube pressure R scores were higher in the two groups at 3 months, 6 months and 12 months after operation（P<0.05）; 3 months, 6 months and 12 months after operation, the scores of Eustachian tube dysfunction, the pure tone listening threshold of each frequency in the observation group were lower than those in the control group（P<0.05）, and Eustachian tube pressure R scores were higher than those in the control group（P<0.05）. Compared with the control group, the incidence of complications and recurrence rate 1 year after operation were lower in the observation group（P<0.05）. Compared with before operation, the scores of life quality in the two groups were higher at 3 months, 6 months and 12 months after operation（P<0.05）; 3 months, 6 months and 12 months after operation, the scores of life quality were higher in the observation group than the control group（P<0.05）. Conclusion:Tympanotomy combined with balloon dilatation of Eustachian tube can effectively improve the Eustachian tube function of adult patients with chronic recurrent secretory otitis media, it has impressiveclinical effects. On the one hand,it can be better to promote the recovery of patients' hearing and improve the clinical cure rate of patients; On the other hand, it reduce the occurrence of complications and disease recurrence greatly, so the quality of the patients' life were improved significantly.

The expression of VEGF and VEGFR in endotoxin induced otitis media with effusion in rats

OBJECTIVE

To investigate the expression and correlation of vascular endothelial growth factor (VEGF) and its receptor with hypoxia-inducible factor-1 α (HIF-1 α) in otitis media with effusion (OME).

METHODS

A rat model of OME was induced by injection of lipopolysaccharide (LPS) into the middle ear. Hematoxylin and eosin (HE) staining was used to observe the pathomorphological changes of the tympanic cavity in the middle ear of rats. Immunohistochemistry (IHC), western blotting and RT-qPCR were used to determine the mRNA and protein expression of VEGF, VEGFR-1, VEGFR-2 and HIF-1α in mucosa of tympanic cavity mucosa, respectively.

RESULTS

In the OME group, the epithelial space of the middle ear mucosa was significantly thickened and infiltration of a large number of inflammatory cells was found on postoperative day (POD), and the otitis media basically subsided 2 weeks after operation. VEGF mRNA expression was significantly increased on POD 1, and its protein expression peaked on POD 3. HIF-1α mRNA expression was significantly increased and peaked on POD 1, while its protein expression began to increase on POD 3 and was significantly expressed in the middle ear mucosal epithelium. HIF-1α mRNA showed a positive correlation with VEGF mRNA and VEGFR-1 mRNA expression.

CONCLUSION

VEGF mainly plays a role in the acute phase of OME, and it is abundantly expressed mediated by HIF-1α. And then it play a role in vasodilatation and increase of vascular permeability, thus promoting the generation of middle ear effusion.