Inhibitors of cholera toxin-induced adenosine diphosphate ribosylation of membrane-associated proteins block stem cell differentiation

Two potent inhibitors of mono-adenosine diphosphate (ADP) ribosylation have recently been described and characterized, named p- methoxylbenzylaminodecamethylene guanidine sulfate (MBAMG) and benzylaminododecylguanine hydrochloride (BADGH). We have used these agents to investigate the role of ADP ribosylation in hematopoiesis using long-term marrow cultures. The addition of MBAMG (10(-6) mol/L) or BADGH (5 X 10(-4) mol/L) led to both an inhibition of mature cell production and the development of colony-stimulating factor (CSF-1)- responsive GM-CFC, but had no effect upon spleen colony-forming units (CFU-S) or on progenitor cells which respond to the multilineage stimulating factor present in WEHI-3B cell-conditioned medium. These data indicate that these inhibitors of mono-ADP ribosylation can block the commitment and/or differentiation of stem cells and infers that ADP ribosylation may be of some importance in the hematopoietic process.