Figure 1

Thimerosal increases BDNF levels in cultured microglia and neurons: Mediation by zinc and metalloproteases. (A) Primary cultures of microglia and neuron were exposed to thimerosal (TM; 1αM) for 60min, and the resulting increase in free zinc was analyzed by FluoZin-3AM staining. Scale bar: 100αm. Representative of nα=α4 individual experiments. (B) Mixed cortical cell cultures were exposed to thimerosal (TM; 1αM) for 60min. In situ zymography for MMP showed that TM exposure induced MMP activation in neuronal cells. APMA, a potent MMP activator, also induced similar increases in MMP activity, whereas addition of GM6001 (GM), an MMP inhibitor, reduced increases in MMP activity by TM. Scale bar: 100αm. The image is representative of nα=α3 individual experiments. (C) Western blots of microglial (top left) and neuronal (top right) cells with anti-BDNF antibody revealed that treatment with TM increased levels of BDNF in both cell types. Addition of GM6001 (GM) attenuated the increase in BDNF. The image is representative of nα=α4 individual experiments. Bottom row graphs represent respective densitometric analysis for each blots, in which BDNF/Actin for CTL (control) was set as 1. *pα<α0.05 vs. CTL, #pα<α0.05 vs. TM.