In vivo expression of the interleukin 4 receptor alpha by astrocytes in epilepsy cerebral cortex

Cytokine. 2000 Nov;12(11):1656-61. doi: 10.1006/cyto.2000.0773.

Abstract

We reported previously that non-neoplastic astrocytes (derived from brain tissues of patients with epilepsy) expressed interleukin 4 receptor alpha (IL-4Ralpha) and responded to interleukin 4 (IL-4) in culture. To determine whether reactivity of cultured astrocytes was relevant to primary tissue, we investigated IL-4Ralpha expression in specimens of non-neoplastic cerebral cortex removed for surgical treatment of intractable epilepsy compared to specimens of glial tumours, which have been reported to contain IL-4Ralpha. Freshly frozen tissues from eight cases (four epilepsy, four malignant astrocytoma) were evaluated for IL-4Ralpha expression by reverse-transcriptase polymerase chain reaction (RT-PCR), Southern blotting, and double-labelled immunohistochemistry with antibodies to IL-4Ralpha and glial fibrillary acidic protein (GFAP). IL-4Ralpha mRNA was detectable in both non-neoplastic and neoplastic tissues, whereas interleukin 2 receptor gamma chain (IL-2Rgammac) mRNA was not found. By immunohistochemistry, IL-4Ralpha protein co-localized to cells displaying GFAP and astrocytic morphology in epilepsy tissues. As anticipated, IL-4Ralpha was detectable in astrocytoma, but, surprisingly, was also observed in GFAP-positive, non-neoplastic "reactive" astrocytes adjacent to tumour. Results are consistent with the concept that non-neoplastic epilepsy astrocytes express IL-4Ralpha in situ, thus confirming in vitro studies and implying IL-4 sensitivity in vivo.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / metabolism
  • Astrocytes / metabolism*
  • Blotting, Southern
  • Brain / pathology
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology
  • Cells, Cultured
  • Cerebral Cortex / metabolism*
  • Epilepsy / metabolism*
  • Glial Fibrillary Acidic Protein / metabolism
  • Glioblastoma / metabolism
  • Glioblastoma / pathology
  • Humans
  • Immunohistochemistry
  • Interleukin-4 / pharmacology*
  • RNA, Messenger / metabolism
  • Receptors, Interleukin-2 / metabolism
  • Receptors, Interleukin-4 / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured

Substances

  • Actins
  • Glial Fibrillary Acidic Protein
  • RNA, Messenger
  • Receptors, Interleukin-2
  • Receptors, Interleukin-4
  • Interleukin-4