Infusion of human embryonic kidney cell line conditioned medium reverses kainic acid induced hippocampal damage in mice.

Abstract

Hippocampal neurodegeneration is one of the hallmarks in neurological and neurodegenerative diseases such as temporal lobe epilepsy and Alzheimer disease. Human embryonic kidney (HEK) cells are a mixed population of cells, including neurons, and their conditioned medium is enriched with erythropoietin (EPO). Because EPO is a known neuroprotectant, we hypothesized that infusion of HEK cells or HEK-conditioned medium (HEK-CM) may provide neuroprotection against kainic acid (KA)-induced hippocampal damage in mice. Adult CF1 mice were treated with KA to induce hippocampal damage. On 3rd and 5th days after KA treatment, HEK cells or HEK-CM was infused intravenously through the tail vein. On the 7th and 8th days after KA treatment, all groups of mice were subjected to cognitive and depression assessment by use of a novel object recognition test and a forced swim test, respectively. Subsequent to this assessment, mice were killed and the brain samples were used to assess the histopathology and messenger RNA expression for EPO and B-cell lymphoma-2 (Bcl-2). We found that infusion of HEK cells/HEK-CM improves cognitive function and alleviates symptoms of depression. Histological assessment demonstrates complete neuroprotection against KA-mediated excitotoxicity, and the hippocampal cytoarchitecture of HEK cells/HEK-CM treated mice was comparable to normal control mice. HEK cells/HEK-CM treatment could provide neuroprotection by upregulating the endogenous EPO and Bcl-2 in KA-treated mice. Our present data demonstrate for the first time that infusion of HEK cells/HEK-CM can prevent excitotoxic hippocampal damage and alleviate consequent behavioral abnormalities.