In this study, we demonstrate, for the first time,
estrogen-related receptor (ERR) regulation of the physiological and biochemical status of
testicular tumor Leydig cells. In a mouse
tumor Leydig cells, ERRs (α, β, and γ) were silenced via
siRNA. Cell morphology and cell physiology (proliferation and observation of monolayer formation) were performed by inverted phase-contrast microscope. Leydig cell functional markers (
steroid receptors and signaling molecules) were examined by immunofluorescence and Western blotting. Additionally,
progesterone secretion was assessed. Mitochondrial mass and membrane potential were analyzed by flow-cytometry while cGMP and Ca2+ concentrations were analyzed using immunoenzymatic and colorimetric assays, respectively. These results revealed, ERRs indirectly regulate Leydig cell proliferation while ERRα and β affect cell monolayer formation. ERRs interact with canonical and membrane
estrogen receptors (ERα, ERβ, and GPER),
androgen receptor,
metalloproteinase (
MMP 9),
protein kinase A (PKA), extracellular-regulated
kinase (ERK), and neurogenic locus notch homolog
protein 2 (Notch2). Depending on the type of ERR knocked down, coupled with
estradiol treatment, changes in
progesterone concentration and cGMP and Ca2+ concentrations constitute a microenvironment that may effect
tumor Leydig cell characteristics. ERRs should be considered important factors in developing of innovating approaches that target
pathological processes of testicular Leydig cells.