FGF21 Modulates Hippocampal Cold-shock Proteins and CA2-subregion Proteins in Neonatal Mice with Hypoxia-ischemia
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Background: Fibroblast growth factor 21 (FGF21) is a neuroprotectant with cognitive enhancing effects but with poorly characterized mechanism(s) of action, particularly in females. Prior studies suggest that FGF21 may regulate cold-shock proteins (CSPs) and CA2-marker proteins in the hippocampus but empirical evidence is lacking.
Methods: We assessed in normothermic postnatal day (PND) 10 female mice, if hypoxic-ischemic (HI) brain injury (25 min 8% O/92% N) altered endogenous levels of FGF21 in serum or in the hippocampus, or its receptor β-klotho. We also tested if systemic administration of FGF21 (1.5 mg/kg) modulated hippocampal CSPs or CA2 proteins. Finally, we measured if FGF21 therapy altered markers of acute hippocampal injury.
Results: HI increased endogenous serum FGF21 (24 h), hippocampal tissue FGF21 (4d), and decreased hippocampal β-klotho levels (4d). Exogenous FGF21 therapy modulated hippocampal CSP levels, and dynamically altered hippocampal CA2 marker expression (24 h and 4d). Finally, FGF21 ameliorated neuronal damage markers at 24 h but did not affect GFAP (astrogliosis) or Iba1 (microgliosis) levels at 4d.
Conclusions: FGF21 therapy modulates CSP and CA2 protein levels in the injured hippocampus. These proteins serve different biological functions, but our findings suggest that FGF21 administration modulates them in a homeostatic manner after HI.
Impact: Hypoxic-ischemic (HI) injury in female post-natal day (PND) 10 mice decreases hippocampal RNA binding motif 3 (RBM3) levels in the normothermic newborn brain. HI injury in normothermic newborn female mice alters serum and hippocampal fibroblast growth factor 21 (FGF21) levels 24 h post-injury. HI injury in normothermic newborn female mice alters hippocampal levels of N-terminal EF-hand calcium binding protein 2 (NECAB2) in a time-dependent manner. Exogenous FGF21 therapy ameliorates the HI-mediated loss of hippocampal cold-induced RNA-binding protein (CIRBP). Exogenous FGF21 therapy modulates hippocampal levels of CA2-marker proteins after HI.
Chen Y, Cui H, Han Z, Xu L, Wang L, Zhang Y Neurochem Res. 2024; 49(10):2910-2925.
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Jackson T, Herrmann J, Fink E, Au A, Kochanek P Pediatr Crit Care Med. 2023; 25(3):259-270.
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Snyder K, Gorse K, Kochanek P, Jackson T Cell Death Discov. 2023; 9(1):379.
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Herrmann J, Fink E, Fabio A, Berger R, Janesko-Feldman K, Gorse K Ther Hypothermia Temp Manag. 2023; 14(2):99-109.
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