Maternal and early life arsenite exposure impairs neurodevelopment and increases the expression of PSA-NCAM in hippocampus of rat offspring.
Although epidemiological investigations indicate that chronic arsenic exposure can induce developmental neurotoxicity in children, the molecular mechanisms are still poorly understood. Neural cell adhesion molecules (NCAMs) play critical roles during the development of nervous system. Polysialylation of NCAM (PSA-NCAM) is a critical functional feature of NCAM-mediated cell interactions and functions. The present study aimed at investigating the effects of maternal and early life arsenite exposure on NCAM and PSA-NCAM in rat offspring. To this end, mother rats were divided into three groups and exposed to 0, 2.72 and 13.6mg/L sodium arsenite, respectively, during gestation and lactation. After weaning, rat offspring drank the same solution as their mothers. Neural reflex parameters, arsenic level of hippocampus, ultra-structural changes of hippocampus, the expression of NCAM, PSA-NCAM and two polysialyltransferases (STX and PST) in rat offspring were assessed. Arsenite exposure significantly prolonged the time of completing reflex response of surface righting, negative geotaxis and cliff avoidance of rat offspring in 13.6mg/L As-exposed group. Neurons and capillaries presented pathological changes and the expression of NCAM, PSA-NCAM, STX and PST were up-regulated in hippocampus of rat offspring exposed to arsenite. These results indicated that maternal arsenite exposure increases the expression of PSA-NCAM, NCAM and polysialyltransferases in hippocampus of rat offspring on postnatal day (PND) 21 and PND120, which might contribute to the impaired neurodevelopment following arsenite exposure.