Multiple proteases regulate neurite outgrowth in NB2a/dl neuroblastoma cells.

摘要: : Mouse NB2a/dl neuroblastoma cells elaborate axonal neurites in response to various chemical treatments including dibutyryl cyclic AMP and serum deprivation. Hi-rudin, a specific inhibitor of thrombin, initiated neurite outgrowth cultured the presence serum; however, these typically retracted within 24 h. The cysteine protease inhibitors leupeptin N-acetyl-leucyl-leucyl-norleucinal (CI; preferential micromolar calpain but also inhibits millimolar calpain) at 10-6M considerably enhanced induced by deprivation, could not induce neuritogenesis serum. A third inhibitor, N-acetyl-leucyl-leucyl-methional (CII; calpain), had no detectable effects itself. Cells treated simultaneously with hirudin either leupeptin, CI, or CII elaborated stable Cell-free enzyme assays demonstrated that inhibited thrombin calpain, CI both proteases. These results imply distinct proteolytic events, possibly involving more than one protease, regulate initiation subsequent elongation stabilization neurites. Since addition exogenous serum-free medium did modify outgrowth, events affected may be intracellular involve proteases from calpain.