Expression and Distribution of the Na+ : HCO3- Cotransporter(NBC) and K+ : Cl- Cotransporter(KCC) mRNA in Human Nasal Mucosa and Nasal Polyp / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Electrolyte transport by nasal epithelia has been suggested to be important for controlling the quantity and composition of the nasal fluid and may play an important role in the development of nasal polyps. Transepithelial transport of ion and water in various fluid-transporting epithelia is strictly dependent on the localization of specific membrane proteins in the polarized epithelial cells. Na+ : HCO3-cotransporter (NBC) transports Na+ and HCO3- into the intracellular from extracellular space and induces the evacuation of H+, regulating pH. K+ : Cl- cotransporter (KCC) controls the cell volume and resorption of NaCl which is associated with the extracellular transport of K+ and Cl-. The present study evaluated the presense of mRNA for NBC and KCC in human inferior turbinate and nasal polyp. MATERIALS AND METHOD: The expression of NBC and KCC mRNA isoforms in inferior turbinate mucosa and nasal polyp was evaluated, using RT-PCR and in situ hybridization. RESULTS: RT-PCR revealed that the inferior turbinate and nasal polyp mucosa expressed kNBC, KCC1 and 4 mRNA. In in situ hybridization, their distribution was noted in the epithelial layer and submucosal glands of both mucosa. CONCLUSION: These results indicate that these types of ion transporters are expressed in human nasal mucosa and nasal polyp, controlling the fluid and ion transport in nasal epithelium and submucosal glands.

Expression of Guanylin and Uroguanylin mRNA in Human Nasal Mucosa and Nasal Polyp / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Guanylin and uroguanylin are small, heat-stable peptides that were originally isolated from the small intestine and urine, respectively. Functionally, it has been proposed that these peptides can regulate the ion and water transport in various fluid-transporting epithelia. The present study evaluated the presence of mRNAs for the human guanylin and uroguanylin in human inferior turbinate mucosa and nasal polyp. MATERIALS AND METHOD: The expression and localization of mRNA for both peptides were investigated in inferior turbinate tissues and nasal polyp using reverse transcriptase polymerase chain reaction (RT-PCR) and in situ hybridization. RESULTS: The mRNAs for both peptides were detected in human turbinate mucosa and nasal polyp. In situ hybridization revealed that they were localized in the epithelial layer and submucosal glands of inferior turbinate mucosa and in the epithelial layer of nasal polyp. However, their expression in the superficial epithelium of nasal polyp was noted at lower levels than in the inferior turbinate mucosa. CONCLUSION: These results indicate that guanylin and uroguanylin in the nasal mucosa may participate in normal physiological processes, but also suggest that altered expression of these genes in nasal polyp may cause impaired electrolyte and water transport across the epithelial cells.