Expression of renin/prorenin receptor in rat kidney and cultured mesangial cells / 生理学报

ABSTRACT

The renin/prorenin receptor (RnR) has recently been cloned and demonstrated to exist in different cells in the cardiovascular and renal systems, playing an important role in physiological and pathophysiological situations. In the present study, we used immunofluorescence method to identify whether and where the RnR expressed in cultured rat renal mesangial cells (MCs) and rat kidney. By using the prorenin handle region peptide (HRP) as a decoy peptide of the RnR, we observed the distribution of the HRP-RnR complex in the MCs. Our results showed that the RnR was localized in the perinuclear zone and plasma membrane of the MCs. At the organ level, the RnR was observed in the mesangium of cortical glomeruli in rat kidney. The FITC-labeled HRP (FITC-HRP) translocated from cell culture medium into the cytoplasm within 30 s. Colocalization of the HRP and RnR was observed mainly on the cell membrane and in the perinuclear zone of cytoplasm by using immunofluorescence and confocal microscopy. At 30 min the FITC-HRP was mainly observed in the nucleus while the RnR remained in the perinuclear zone of cytoplasm. Taken together, our results confirm the expression of RnR in the renal MCs. It is suggested that internalization of the RnR after binding with its ligand is at least one of the pathways through which the RnR exerts its biological actions.