Dynamics of glial fibrillary acidic protein distribution in cultured glomerular podocytes and mesangial cells of the rat kidney

Abstract

Glial fibrillary acidic protein (GFAP) has recently been shown to be expressed in the glomerular podocytes and mesangial cells (MC) of kidney (Buniatian et al (1998) Biol Cell 90, 53-61). The different localization of GFAP in podocytes and MC has raised the question whether this might reflect specific cellular functions. To address this question, in the present study podocytes and MC in early (2, 3 day-old), prolonged (5, 7 day-old) and late (14, 21 day-old) primary cultures from out-growths of glomerular explants were used. Double-immunolabeling studies demonstrated that podocytes transiently acquire myofibroblastic features, characterized by the expression of smooth muscle alpha-actin (SMAA) and increased perinuclear reaction of GFAP in prolonged cultures. The morphological differentiation of cobblestone-like podocytes into process-bearing cells was followed by loss of the myofibroblastic marker, SMAA, de novo expression of desmin, and distribution of GFAP, vimentin and desmin into the processes. In late culture, GFAP and SMAA were nearly absent from the podocytes which maintained the cobblestone-like morphology. By contrast, the myofibroblastic features gained by MC during prolonged culturing increased with time. A myofibroblast-like cytoskeleton of podocytes and MC similar to that of healthy astrocytes suggest an increased spectrum of functional activities of these cells during the acquisition of myofibroblastic features. In addition, the present study provides a new combination of biochemical and biological features by which podocytes and MC can be distinguished in culture.

Proteomic responses in the gills of fathead minnows (Pimephales promelas, Rafinesque, 1820) after 6 months and 2 years of continuous exposure to environmentally relevant dietary226Ra

“…GFAP is also known to be expressed outside the cells of the central nervous system (Doodnath et al 2010); e.g. hepatic stellate cells (Tennakoon et al 2013), glomerular podocytes and mesangial cells (Buniatian et al 1999), and Leydig cells (Davidoff et al 2002). This raises the possibility that GFAP might be synthesised in gill cells, particularly since gills are known to contain neuroepithelial cells (reviewed by Zachar and Jonz 2012).…”