Abstract

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 (alpha, beta, and gamma) were silenced via siRNA. Cell morphology and cell physiology (proliferation and observation of monolayer formation) were observed 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 ERRalpha and beta affect cell monolayer formation. ERRs interact with canonical and membrane estrogen receptors (ERalpha, ERbeta, 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.