XXXX + Progenitors Derived From Embryonic Stem Cells Penetrate Glial Scar and Promote Axonal Outgrowth Into White Matter After @entity1566 .

@entity1 @entity66 @entity1476 @entity1495 @entity1566 @entity28557 @entity130 @entity597
UNASSIGNED: The @entity66 resulting from @entity1566 is rich in chondroitin @entity597 proteoglycan (CSPG), a formidable barrier to axonal regeneration. We explored the possibility of breaching that barrier by first examining the scar in a functional in vitro model. We found that embryonic stem cell-derived neural lineage cells (ESNLCs) with prominent expression of @entity28557 ( @entity28557 ) survived, passed through an increasingly inhibitory gradient of CSPG, and expressed @entity1495 ( @entity1495 ) at the appropriate stage of their development. Outgrowth of axons from ESNLCs followed because the migrating cells sculpted pathways in which CSPG was degraded. The degradative mechanism involved @entity1495 but not @entity1476 . To confirm these results in vivo, we transplanted ESNLCs directly into the cavity of a contused spinal cord 9 days after injury. A week later, ESNLCs survived and were expressing both @entity28557 and @entity1495 . Their axons had grown through long distances (>10 mm), although they preferred to traverse white rather than gray matter. These data are consistent with the concept that expression of inhibitory CSPG within the @entity130 is an important impediment to regeneration but that @entity28557 + progenitors derived from ESNLCs can modify the microenvironment to allow axons to grow through the barrier. This beneficial action may be partly due to developmental expression of @entity1495 . We conclude that it might eventually be possible to encourage axonal regeneration in the @entity1 spinal cord by transplanting ESNLCs or other cells that express @entity28557 .
