Select de novo gene and protein expression during renal epithelial cell culture in rotating wall vessels is shear stress dependent

The rotating wall vessel has gained popularity as a clinical cell culture t ool to produce hormonal implants. It is desirable to understand the mechani sms by which the rotating wall vessel induces genetic changes, if we are to prolong the useful life of implants. During rotating wall vessel culture g ravity is balanced by equal and opposite hydrodynamic forces including shea r stress. The current study provides the first evidence that shear stress r esponse elements, which modulate gene expression in endothelial cells, are also active in epithelial cells. Rotating wall culture of renal cells chang es expression of select gene products including the giant glycoprotein scav enger receptors cubulin and megalin, the structural microvillar protein vil lin, and classic shear stress response genes ICAM, VCAM and MnSOD. Using a putative endothelial cell shear stress response element binding site as a d ecoy, we demonstrate the role of this sequence in the regulation of selecte d genes in epithelial cells. However, many of the changes observed in the r otating wall vessel are independent of this response element. It remains to define other genetic response elements modulated during rotating wall vess el culture, including the role of hemodynamics characterized by 3-dimension ality, low shear and turbulence, and cospatial relation of dissimilar cell types.