Cohort #2: hGRPs with FK-506/Rapamycin differentiated into astrocytes in SOD1^G93A cervical spinal cord.

<p>Transplanted HuNA⁺ hGRPs differentiated into GFAP⁺ astrocytes by disease endstage in gray matter both near the injection site (<b>A</b>) and at distances up to 6 mm (<b>B</b>: image represents region with migrating cells approximately 3 mm caudal to the injection site), as well as in white matter (<b>C</b>). At disease endstage, approximately 50–80% of all HuNA⁺ cells co-expressed the astrocyte marker GFAP at sites within 1 mm rostral or caudal of the injection sites, regardless of whether cells were found in gray (<b>A</b>) or white (<b>C</b>) matter (<b>D</b>). This percentage decreased at greater distances from the injection sites (<b>B</b>, <b>D</b>). In addition to the pan-GFAP marker, transplanted-derived astrocytes were labeled with the human-specific GFAP marker (<b>E</b>–<b>F</b>). Only a minor fraction (approximately 1%) of HuNA⁺ cells co-expressed the microglial marker, Iba1 (<b>G</b>–<b>H</b>). Arrowheads denote HuNA/GFAP double-labeled cells in panels <b>A</b> and <b>C</b>. Scale bars: 50 µm.