NF ‐ κ B Signaling is Involved in the Effects of Intranasally Engrafted Human Neural Stem Cells on Neurofunctional Improvements in Neonatal Rat Hypoxic–Ischemic Encephalopathy

Summary Aim Hypoxic–ischemic encephalopathy ( HIE ) is a common neurological disease in infants with persistent neurobehavioral impairments. Studies found that neural stem cell ( NSC ) therapy benefits HIE rats; however, the mechanisms underlying are still unclear. The current study investigated the efficacy and molecular events of human embryonic neural stem cells ( hNSC s) in neonatal hypoxic–ischemic ( HI ) rats. Methods PKH ‐26‐labeled h NSC s were intranasally delivered to P7 Sprague Dawley rats 24 h after HI . Neurobehavioral tests were performed at the indicated time after delivery: righting reflex and gait testing at D1, 3, 5, and 7; grid walking at D7 and 14; social choice test ( SCT ) at D28; and Morris water maze from D35 to 40. Protein expression was determined by Western blot analysis. Brain damage was assessed by cresyl violet staining and MBP staining. h NSC distribution and differentiation were observed by in vivo bioluminescence imaging and immunofluorescence staining. Results (1) h NSC s migrated extensively into brain areas within 24 h after the delivery, survived even at D42 with the majority in ipsi‐hemisphere, and could be co‐labeled with NeuN or GFAP . (2) hNSC s reduced the upregulation in cytosolic IL ‐1 β , p‐I κ B α , and NF ‐ κ B p65 levels, whereas enhanced nuclear p65 expression in HI rats at D3 after the delivery. (3) hNSC s decreased HI ‐induced brain tissue loss and white matter injury at D42 after the delivery. (4) hNSC s improved neurological outcomes in HI rats in the tests of righting reflex (within 3 days), gait (D5), grid (D7), SCT (D28), and water maze (D42). Conclusion Intranasal delivery of h NSC s could prevent HI ‐induced brain injury and improve neurobehavioral outcomes in neonatal HI rats, which is possibly related to the modulation of NF ‐ κ B signaling.