Experimental study of dopamine ameliorating the inflammatory damage of olfactory bulb in mice with allergic rhinitis / 中华耳鼻咽喉头颈外科杂志

Objective: To investigate the effects of dopamine on olfactory function and inflammatory injury of olfactory bulb in mice with allergic rhinitis (AR). Methods: AR mouse model was established by using ovalbumin (OVA), and the mice were divided into two groups: olfactory dysfunction (OD) group and without OD group through buried food pellet test (BFPT). The OD mice were randomly divided into 2 groups, and OVA combined with dopamine (3, 6, 9 and 12 days, respectively) or OVA combined with an equal amount of PBS (the same treatment time) was administered nasally. The olfactory function of mice was evaluated by BFPT. The number of eosinophils and goblet cells in the nasal mucosa were detected by HE and PAS staining. Western blotting, immunohistochemistry or immunofluorescence were used to detect the expression of olfactory marker protein (OMP) in olfactory epithelium, the important rate-limiting enzyme tyrosine hydroxylase (TH) of dopamine, and the marker proteins glial fibrillary acidic protein (GFAP) and CD11b of glial cell in the olfactory bulb. TUNEL staining was used to detect the damage of the olfactory bulb. SPSS 26.0 software was used for statistical analysis. Results: AR mice with OD had AR pathological characteristics. Compared with AR mice without OD, the expression of OMP in olfactory epithelium of AR mice with OD was reduced (F=26.09, P<0.05), the expression of GFAP and CD11b in the olfactory bulb was increased (F value was 38.95 and 71.71, respectively, both P<0.05), and the expression of TH in the olfactory bulb was decreased (F=77.00, P<0.05). Nasal administration of dopamine could shorten the time of food globule detection in mice to a certain extent, down-regulate the expression of GFAP and CD11b in the olfactory bulb (F value was 6.55 and 46.11, respectively, both P<0.05), and reduce the number of apoptotic cells in the olfactory bulb (F=25.64, P<0.05). But dopamine had no significant effect on the number of eosinophils and goblet cells in nasal mucosa (F value was 36.26 and 19.38, respectively, both P>0.05), and had no significant effect on the expression of OMP in the olfactory epithelium (F=55.27, P>0.05). Conclusion: Dopamine can improve olfactory function in mice with AR to a certain extent, possibly because of inhibiting the activation of glial cells in olfactory bulb and reducing the apoptotic injury of olfactory bulb cells.

The expression and significance of TRPM8 among chronic rhinosinusitis with nasal polyps / 中华耳鼻咽喉头颈外科杂志

Objective: To compare the expression and difference of melastatin-related transient receptor potential 8(TRPM8) among chronic rhinosinusitis, nasal polyps and normal mucosa tissues. And to explore the significant expression of TRPM8 among CRSwNP. Methods: Fifty-one patients underwent endoscopic sinus surgery in the Department of Otorhinolaryngology Head and Neck Surgery of Renmin Hospital of Wuhan University from February 2019 to January 2020 were recruited, including 33 males and 18 females, aged from 14 to 65 years old (34.55±1.689).Immunohistochemistry was used to detected the expression of TRPM8 protein among CRSsNP(17),CRSwNP (17) and control tissuses(17). In addition, the correlation between the expression of TRPM8 protein in CRSwNP patients and preoperative CT Lund-Mackay scores and preoperative VAS scores and sinonasal outcome test-20 scores was analyzed, respectively. The primary human nasal epithelial cells were cultured in vitro and the expression of TRPM8 was detected by quantitative real-time PCR and western blotting . The tissue in control group, chronic rhinosinusitis without nasal polyps (CRSsNP) group and the CRSwNP group were collected and grinded into tissue homogenized. The expression of TRPM8 protein was detected by western blotting after 24 h stimulation after homogenate was added into the medium of RPMI 2650 and primary nasal epithelial cells. Results: Compared with the control, the expression of TRPM8 was significantly up-regulated in nasal polyps (t=6.852, P<0.05). TRPM8 was mainly expressed in epithelial cells. The expression of TRPM8 in the epithelial cells of CRSsNP had no difference with the control group (t=1.980, P>0.05). In addition, the expression of TRPM8 in CRSwNP patients was positively correlated with the preoperative CT Lund-Mackay scores and VAS scores and SNOT-20 scores (r=0.512, P<0.05;r=0.853, P<0.01;r=0.814, P<0.01). After cultured primary epithelial cells in vitro, the expression level of TRPM8 in epithelial cells derived from nasal polyp was significantly higher than that in control group (t=8.845, P<0.05). By adding the homogenization of control and CRSsNP and CRSwNP tissues, the expression of TRPM8 in RPMI 2650 cells and primary nasal epithelial cells was changed and that was significantly increased after adding the homogenization of the group of CRSwNP. Conclusion: TRPM8 is highly expressed in nasal polyps epithelial cells, suggesting that TRPM8 may be involved in the pathogenesis of nasal polyps regulated by nasal epithelial cells.