Research ReportIncreased CD147 (EMMPRIN) expression in the rat brain following traumatic brain injury

- EMMPRIN stimulates the production of MMPs.
- EMMPRIN and MMP-9 significantly increase in the injured cortex after TBI.
- The up-regulation of EMMPRIN is associated with increased CD147 expression.
- EMMPRIN/MMP-9 up-regulation may contribute to secondary brain injury following TBI.

The extracellular matrix metalloproteinase inducer (EMMPRIN), or CD147, has been known to play a key regulatory role in vascular permeability and leukocyte activation by inducing the expression of matrix metalloproteinases (MMPs). The effects of traumatic brain injury on the expression of EMMPRIN remain poorly understood. In this study, we investigated changes in EMMPRIN expression in a rat model of fluid percussion injury (FPI) and examined the potential association between EMMPRIN and MMP-9 expression. Adult male rats were subjected to FPI. EMMPRIN expression was markedly up-regulated in the brain tissue surrounding the injured region 6-48 h after TBI, as measured by immunoblot and immunohistochemistry. EMMPRIN expression was localized to inflammatory cells. The increase in EMMPRIN expression was temporally correlated with an increase in MMP-9 levels. These data demonstrate, for the first time, changes in CD147 and MMP-9 expression following TBI. These data also suggest that CD147 and MMP-9 may play a role in vascular injuries after TBI.