Estradiol stimulates cell proliferation via classic estrogen receptor-alpha and G protein-coupled estrogen receptor-1 in human renal tubular epithelial cell primary cultures.

This work was aimed to determine the effect of 17β-estradiol (17βE) on cell proliferation in human renal tubular epithelial cells (HRTEC) isolated from kidneys from pediatric subjects, as well as the role of estrogen receptors involved in the 17βE proliferative response. Treatment with 17βE (10 nmol/L, 24 h) significantly stimulated cell proliferation, measured by 5-bromo-2-deoxyuridine (BrdU) uptake, in HRTEC primary cultures and in tubular structures obtained by 3D cultured-HRTEC. Incubation of HRTEC with the G protein-coupled estrogen receptor 1 (GPER-1) agonist G-1 increased BrdU uptake. Incubation of HRTEC with 17βE activated the classic estrogen receptor alpha (ERα) but not ERβ. Treatment of HRTEC with the GPER-1 antagonist G-15, the ER inhibitor ICI182,780, or the β-catenin inhibitor iCRT14, completely abrogated the increase in BrdU uptake induced by 17βE. We also show that 17βE stimulated β-catenin protein expression and translocation to the nucleus of HRTEC, effects that were abrogated by G-15 and ICI 182,780. In conclusion, estradiol stimulates cell proliferation in HRTEC primary cultures through both ERα and GPER-1 estrogen receptors and involves β-catenin activation.