mRNA and protein expression profile of progranulin after spinal cord injury. Expression of progranulin was identified in the microarray and followed the expression profile of the delayed-expression cluster. Expression of progranulin peaked at 7 days post-injury and remained up-regulated through the end of the study (A). Protein expression was confirmed using immunohistochemistry at 28 days post-injury. Sham-injured tissue showed no progranulin positive cells at the lesion site (B). Injured tissue, however showed a large number of progranulin-positive cells (B). Double-labeling with Iba-1 (C) and NeuN (D) showed correlation of expression in microglia and neurons. Size bar = 200 μm (B), 100 μm (C, D).