Cytoprotection by darbepoetin/epoetin alfa in pig tubular and mouse mesangial cells.

Background: Erythropoietin has recently been found to have cytoprotective effects in the central nervous system (CNS) and retina. The purpose of this study was to determine if darbepoetin alfa (DA) has cytoprotective properties in renal tissues.

Methods: DA was studied in LLC/PK1 and mesangial cells.

Multiple tristetraprolin sequence domains required to induce apoptosis and modulate responses to TNFalpha through distinct pathways.

Expression of the immediate early protein tristetraprolin (TTP) is induced by numerous stimuli, including tumor necrosis factor-alpha (TNFalpha). Evidence indicates that TTP limits production of TNFalpha and other cytokines by directly binding and destabilizing their mRNAs. This effect seems to require only the conserved TTP zinc finger region, and is characteristic of the related proteins TIS11b and TIS11d.

Cytoplasmic localization of tristetraprolin involves 14-3-3-dependent and -independent mechanisms.

The immediate early gene tristetraprolin (TTP) is induced transiently in many cell types by numerous extracellular stimuli. TTP encodes a zinc finger protein that can bind and destabilize mRNAs that encode tumor necrosis factor-alpha (TNFalpha) and other cytokines. We hypothesize that TTP also has a broader role in growth factor-responsive pathways.