Time-dependent effect of combination therapy with erythropoietin and granulocyte colony-stimulating factor in a mouse model of hypoxic-ischemic brain injury

Neurosci Bull. 2014 Feb;30(1):107-17. doi: 10.1007/s12264-013-1397-9. Epub 2014 Jan 16.

Abstract

Erythropoietin (EPO) and granulocyte colony-stimulating factor (G-CSF) are likely to play broad roles in the brain. We investigated the effects of combination therapy with EPO and G-CSF in hypoxic-ischemic brain injury during the acute, subacute, and chronic phases. A total of 79 C57BL/6 mice with hypoxic-ischemic brain injury were randomly assigned acute (days 1-5), subacute (days 11-15) and chronic (days 28-32) groups. All of them were treated with G-CSF (250 μg/kg) and EPO (5000 U/kg) or saline daily for 5 consecutive days. Behavioral assessments and immunohistochemistry for angiogenesis, neurogenesis, and astrogliosis were performed with an 8-week follow-up. Hypoxia-inducible factor-1 (HIF-1) was also measured by Western blot analysis. The results showed that the combination therapy with EPO and G-CSF in the acute phase significantly improved rotarod performance and forelimb-use symmetry compared to the other groups, while subacute EPO and G-CSF therapy exhibited a modest improvement compared with the chronic saline controls. The acute treatment significantly increased the density of CD31(+) (PECAM-1) and α-smooth muscle actin(+) vessels in the frontal cortex and striatum, increased BrdU(+)/PSA-NCAM(+) neurogenesis in the subventricular zone, and decreased astroglial density in the striatum. Furthermore, acute treatment significantly increased the HIF-1 expression in the cytosol and nucleus, whereas chronic treatment did not change the HIF-1 expression, consistent with the behavioral outcomes. These results indicate that the induction of HIF-1 expression by combination therapy with EPO and G-CSF synergistically enhances not only behavioral function but also neurogenesis and angiogenesis while decreasing the astroglial response in a time-dependent manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / drug effects*
  • Disease Models, Animal
  • Drug Therapy, Combination
  • Erythropoietin / therapeutic use*
  • Granulocyte Colony-Stimulating Factor / therapeutic use*
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Hypoxia-Ischemia, Brain / drug therapy*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Motor Activity / drug effects
  • Neurogenesis / drug effects
  • Neuroprotective Agents / therapeutic use*

Substances

  • Hif1a protein, mouse
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Neuroprotective Agents
  • Erythropoietin
  • Granulocyte Colony-Stimulating Factor