Epinephrine evokes renalase secretion via α-adrenoceptor/NF-κB pathways in renal proximal tubular epithelial cells.

BACKGROUND/AIMS Renalase is a recently discovered, kidney-specific monoamine oxidase that metabolizes circulating catecholamines. These findings present new insights into hypertension and chronic kidney diseases. Previous data demonstrated that renalase was mainly secreted from proximal tubules which could be evoked by catecholamines. The purpose of this study is to investigate whether renalase expression is induced by epinephrine via α-adrenoceptor/NFκB pathways. METHODS HK2 cells were utilized to explore renalase expression in response to epinephrine in vitro. Phentolamine, an α-adrenoceptor antagonist, and Tosyl Phenylalanyl Chloromethyl Ketone (TPCK) were used to block α-adrenoceptor and to knock down the transcription factor NFκB, respectively. Renalase expression was analyzed using Western blot and quantitative PCR. RESULTS Both protein and mRNA levels of renalase in HK2 cells increased in response to epinephrine (P<0.05). Epinephrine-evoked renalase expression was attenuated by phentolamine and TPCK separately (P<0.05). CONCLUSION Epinephrine evokes renalase secretion via α-adrenoceptor/NF-κB pathways in renal proximal tubular epithelial cells.