Temporal and Spatial Expression of LGR5 After Acute Spinal Cord Injury in Adult Rats

Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5), a well-characterized marker of stem cell and cancer stem cells (CSCs), is best known as a transmembrance receptor for increases canonical Wnt signaling amplitude. In addition, in some types of human cancers, LGR5 has been found to be overexpressed. However, the distribution and function of LGR5 in spinal cord injury (SCI) are still unknown. In this study, we examined LGR5 expression and cellular localization in rats following acute SCI. Western blot analysis and immunohistochemistry exhibited an important upregulation of LGR5 in injury spinal cord. Double immunofluorescence staining showed that LGR5 was co-expressed with glial fibrillary acidic protein (GFAP). Moreover, we detected that PCNA had colocalization with LGR5 and GFAP after SCI. In the vitro model, we could find the enhanced expression of LGR5 in the primary astrocyte which was induced by the lipopolysaccharide (LPS). In particular, we found the significantly decreased ability for proliferation when this LGR5-specific siRNA transfected primary astrocytes. In a word, this is the first description of LGR5 expression in spinal cord injury. These data indicated that LGR5 might be of great significance in CNS pathophysiology after SCI.