Toxicity of inorganic arsenic and its metabolites on haematopoietic progenitors ¿in vitro¿: comparison between species and sexes.

Inorganic arsenic (iAs) and its metabolites are transferred to the foetus through the placental barrier and this exposure can compromise the normal development of the unborn. For this reason, we assessed the toxicity of sodium arsenite (iAsIII) and its metabolites Dimethylarsinic acid (DMAV), Monomethylarsonic acid (MMAV) and Monomethylarsonous acid (MMAIII) on human haematopoietic cord blood cells and murine bone marrow progenitors in vitro, looking at the effects induced at different concentrations in the two genders. The expression of two enzymes responsible for arsenic biotransformation Arsenic Methyltranferase (AS3MT) and Glutathione S-transferase omega 1 (GSTO1) was evaluated in human cord blood cells. Cord blood and bone marrow cells were exposed in vitro to iAsIII at a wide range of concentrations: from 0.0001 µM to 10 µM. The methylated arsenic metabolites were tested only on human cord blood cells at concentrations ranging from 0.00064 µM to 50 µM. The results showed that iAsIII was toxic on male and female colony forming units to about the same extent both in human and in mouse. Surprisingly, very low concentrations of iAsIII increased the proliferation rate of both human and murine female cells, while male cells showed no significant modulation. MMAV and DMAV did not exert detectable toxicity on the cord blood cells, while MMAIII had a marked toxic effect both in male and female human progenitors. AS3MT mRNA expression was not induced in human cord blood cells after iAsIII exposure. GSTO1 expression decreased after MMAIII treatment. This study provides evidence that exposure to iAsIII and MMAIII at µM concentrations is associated with immunosuppression in vitro.

FERRARIO Daniele;  CROERA Cristina;  BRUSTIO Roberta;  COLLOTTA Angelo;  BOWE Gerard;  VAHTER Marie;  GRIBALDO Laura; 

2011-10-20

ELSEVIER IRELAND LTD

JRC44971

0300-483X,   

http://www.sciencedirect.com/science/article/pii/S0300483X08001765,    https://publications.jrc.ec.europa.eu/repository/handle/JRC44971,   

10.1016/j.tox.2008.04.008,