Altered β-1,4-galactosyltransferase I expression during early inflammation after spinal cord contusion injury

Post-traumatic inflammation has been implicated in secondary tissue damage after spinal cord injury (SCI). β-1,4-Galactosyltransferase I (β-1,4-GalT-I) is a key inflammatory mediator that plays a critical role in the initiation and maintenance of inflammatory reaction in diseases. The aim of the current study was to investigate whether β-1,4-GalT-I is expressed in SCI. Spinal cord contusion model was established in adult rats. Real-time PCR and Western blot analysis were used to detect the spatio-temporal expression of β-1,4-GalT-I after SCI. Lectin-fluorescent staining with RCA-I was used to detect the galactosylation of the membrane glycoproteins. The interaction and colocalization between β-1,4-GalT-I and E-selectin in the injured spinal cords were also assessed by immunoprecipitation of E-selectin and double immunofluorescent staining, respectively. Real-time PCR revealed that β-1,4-GalT-I mRNA reached the peak at 1 d after spinal cord contusion. In situ hybridization indicated that β-1,4-GalT-I mRNA was mainly distributed in the local inflammatory cells, adjacent to the center of injury. Double immunofluorescent staining showed that β-1,4-GalT-I mostly overlapped with ED1-positive macrophages 1 d after SCI, partly colocalized with microglia, neutrophils and a few with oligodendrocytes and astrocytes. The result of Lectin-fluorescent staining with RCA-I was similar to that of double immunofluorescent staining. Terminal galactosylation of E-selectin underwent obvious changes between sham and 3 d after SCI by immunoprecipitation of E-selectin. Thus, the transient expression of high levels of β-1,4-GalT-I may provide new insight into the early inflammation after SCI.