Table 2.
Studies focusing on the expression and distribution of NOS isoforms and concomitant NO production in chronic rhinosinusitis (CRS).
| Authors, Year [Ref. No.] |
Disease (Sample Area) |
Principal Results |
|---|---|---|
| Chen et al. 2000 [28] |
CRS (cultured ethmoid cells) | iNOS expression was augmented by TNF-α and attenuated by dexamethasone, whereas eNOS expression remained unchanged. TNF-α modulated CBF activities through NO production. |
| Kim et al. 2001 [29] |
Normal mucosa (sphenoid sinus) | CBF increased after treatment with L-arginine and was inhibited by L-NAME. Both positive iNOS and eNOS immunostaining were observed in the ciliated cells. |
| Noda et al. 2012 [109] |
ECRS (ethmoid mucosa, NP) | The surgical group showed higher nasal FeNO and lower oral FeNO levels 6 months after ESS, whereas the medical group remained unchanged. Up-regulation and positive immunoreactivity of iNOS was observed in both epithelial cells and submucosal inflammatory cells. |
| Takeno et al. 2013 [110] |
ECRS and non-ECRS (ethmoid mucosa, NP) | ECRS patients showed higher oral FeNO levels and non-ECRS patients showed lower nasal FeNO levels. Positive correlations existed between blood eosinophils and FeNO levels in ECRS patients. Intense NT immunoreactivity was colocalized with eosinophil accumulation and higher NT-positive cells in ECRS patients. |
| Taruya et al. 2015 [140] |
CRSsNP and CRSwNP (ethmoid mucosa, NP) | CRSsNP patients showed increased arginase-2 activities associated with lower nasal FeNO levels. CRSwNP patients showed iNOS upregulation with concomitant higher FeNO levels. |
| Kubota et al. 2017 [111] |
ECRS and non-ECRS (frontal recess mucosa) | ECRS patients showed increased IL-5 and IL-6 mRNA levels in the frontal recess. No difference was observed in TGF-2 and iNOS levels. |
| Yoshida et al. 2019 [112] |
ECRS and non-ECRS (NP) | Nasal NO levels were decreased in ECRS patients and negatively correlated with eosinophil levels and CT scores Nasal NO levels remained unchanged after ESS. Reduction in t-PA levels by Th2 cytokines may inhibit iNOS expression. |
| Vlad et al. 2019 [141] |
CRS with BA or AR (Eth) |
Arginase 2 expression was higher in CRS patients than controls, especially in nonallergic and nonasthmatic CRSsNP patients. No correlation existed between arginase 2 and IL-13 expression. |
AR: allergic rhinitis; BA: bronchial asthma; NOS: nitric oxide synthase; CRS: chronic rhinosinusitis; CRSsNP: CRS without NP; CRSwNP: RS with NP; CBF: ciliary beat frequency; L-NAME: NG-nitro-L-arginine methyl ester; FeNO: fractional concentrations of exhaled NO; ECRS: eosinophilic chronic rhinosinusitis; NP: nasal polyp; ESS: endoscopic sinus surgery; NT: nitrotyrosine; ECP: eosinophil cationic protein; t-PA: tissue-plasminogen activator.