Expression of Transcriptional Factors of GATA4, GATA6 and SF-1 in the Developmental Process of Rat Adrenal Cortex; the Possible Contribution of GATA4 in Limited Expression before Zonal Establishment

Abstract

The adrenal cortex consists of three zones producing different hormones: zona glomerulosa (zG), zona fasciculata (zF) and zona reticularis (zR). Accumulated knowledge has revealed the contribution of transcriptional factors to the functional development of the adrenal cortex, however, the regulatory mechanisms have not yet been fully understood. We studied the expression and localization of transcriptional factors, SF-1, GATA4 and GATA6 by immunohistochemistry in the developmental process, establishing three zones of the rat adrenal cortex. The development of the adrenal cortex was monitored by the expression of cortical enzymes, P45011β, P450aldo, and P450scc on gestational days 15, 16, 18, 19, 20 (G15, G16, G18, G19, G20) and postnatal days 1, 2, 20 (P1, P2, P20) in Spraque-Dawley rats. GATA4 expression was observed in a limited number of cortical cells from early gestation (G15) to the neonatal period (P20) before complete establishment of the cortical zones. Nearing the final phase of zG establishment (P20), GATA4 changed its intracellular localization from the nuclei to the perinuclear region. Another noteworthy finding is that GATA6 translocated from the cytoplasm into the nuclei on G19, followed by a leaning distribution of SF-1 in zG (P1) and changing the distribution of SF-1 from zG to zF parallel to the establishment of zG (P20). In conclusion, we report that GATA4 was detected in the immature phase of the adrenal cortex in limited expression but diminished in the mature adrenal cortex. GATA4 may participate in the gene transcription required for the development of the adrenal cortex.