The disruption of blood-brain barrier induced by long-term arsenic exposure is associated with the increase of MMP-9 and MMP-2: The characteristics are similar to those caused by senescence.

Accumulating evidence suggests that Matrix metalloproteinase-9 (MMP-9) and −2 (MMP-2) are involved in the neuropathological processes by contributing to breaking the extracellular matrix and the tight junctions that constitute the blood-brain barrier (BBB). However, the influences of arsenic (As) on these two MMPs were inconsistent. In the cross-sectional study of 500 adults, serum MMP-2 and MMP-9 positively correlated with urine arsenic. And the positive correlation between urine tAs and serum MMP-9/2 was found in people older than 59 years. In vivo studies, we found that arsenic exposure or senescence might decrease number of neurons and neuritic density and increase serum and cortical MMP-9/2 levels. Furthermore, arsenic exposure or senescence could disrupt the tight junction of BBB and elevate MMP-9 and MMP-2 expression in the cerebral microvascular endothelium. The MMP-9 and MMP-2 are of particular interest when researching the link between arsenic exposure and nerve damage. • Arsenic exposure significantly increased serum MMP2 and MMP9. • Age and arsenic metabolism ability might modify the relationship between arsenic and serum MMP-9 or MMP-2. • Arsenic exposure may disrupt the BBB by increasing endothelial MMP-9 and MMP-2 in mice. • Senescence and arsenic may combine damage to the BBB and increase the risk of brain injury in mice. [ABSTRACT FROM AUTHOR]