The pre-B lymphocyte
protein 3 (VPREB3) is expressed during B cell differentiation and in subsets of mature B lymphocytes and is mainly found in bone marrow and lymphoid tissue germinative centers. So far, its function in B cells remains to be clarified. The
messenger RNA (
mRNA) of VPREB3 was previously detected in
aldosterone-producing
adenomas (APA); however, further information about this
protein in human adrenocortical cells and tissues is currently unavailable. Therefore, in the present study, we, for the first time, investigate the
protein expression of VPREB3 in human adrenocortical tissues. In addition, we approach the previously suggested similarities in expression patterns of
aldosterone-producing cells and Purkinje neurons. Immunohistochemical analysis of VPREB3 was performed in 13 nonpathological adrenals (NA), 6 adrenal glands with idiopathic
hyperaldosteronism (IHA), 18 APA, 5
cortisol-producing
adenomas (CPA), and 5 nonpathological human cerebellum specimens. The
mRNA levels of VPREB3, steroidogenic
enzymes, and other
aldosterone biosynthesis markers were detected in 53 APA samples using real-time RT-PCR (qPCR) and compared to the clinical data of APA patients. In our results, the VPREB3
protein was diffusely detected in APA, partially or weakly detected in CPA, and immunolocalized in the zona glomerulosa of NA and IHA, as well as in the cytoplasm of cerebellar Purkinje cells. In APA, VPREB3
mRNA levels were significantly correlated to plasma
aldosterone (P = 0.026; R = 0.30), KCNJ5 mutations (P = 0.0061; mutated 34:19 wild type),
CYP11B2 (P < 0.0001; R = 0.65), Purkinje cell
protein 4 (PCP4; P < 0.0001; R = 0.53), and
voltage-dependent calcium channels CaV1.3 (P = 0.023; R = 0.31) and CaV3.2 (P = 0.0019; R = 0.42). Based on our data, we hypothesize a possible role for VPREB3 in
aldosterone biosynthesis, and present ideas for future functional studies.