Microglial activation in response to pathological stimuli is characterized by increased migratory activity and potential cytotoxic action on injured neurons during later stages of neurodegeneration. The initial molecular changes in the CNS favoring neuronofugal migration of microglia remain, however, largely unknown. We report that the extracellular matrix… (More)
Figure 7. Activated microglia downregulate TN-R expression by cultured OLs. A, Effect of MCM and cytokines on TN-R protein expression. Media conditioned by OLs maintained for 2 d in MCM, TNF-a (1TNF ), or IL-1b (1IL-1b) were analyzed by sandwich ELISA using monoclonal Ab tn-R1 as a linker. Values for the TN-R content represent mean 6 SD of triplicate measurements of OL-conditioned media obtained from three (for MCM and TNF-a) and two (for IL-1b) independent experiments. In each experimental set, values for TN-R from OLs maintained in culture medium only (-MCM ) were set as 1.0. B, Effect of MCM and TNF-a on TN-R mRNA expression by cultured OLs. Total RNA isolated from OLs maintained for 2 d in culture medium (lanes 1 and 4 ), MCM (lanes 2 and 5), or in culture medium containing TNF-a (lanes 3 and 6 ) was analyzed by RT-PCR using GAPDH-specific (lanes 1–3) and TN-R-specific primers (lanes 4–6 ). The apparent molecular weights of the DNA marker (in base pairs) are shown at the right.