induction of human embryonic stem cells into neuronal differentiation by increasing cyclic adenosine mono phosphate

introduction: to evaluate the camp -mediated ibmx (3-isobutyle -1-methyl xanthin) and db-camp (dibutyryl camp) effects on differentiation of human embryonic stem cells (hescs) into nerve cells were the objectives of this study. methods: we have used royan h1 hesc- derived embryoid bodies with four treatment groups: six days treatment with ibmx (5×10 -4m) and db-camp (10 -9m) (referred to as camp), retinoic acid (ra, 10 -6m), ibmx + db-camp + ra, and control (no treatment). immunocytochemistry was carried out for neural specific antibodies including β-tubulin iii, microtubule associated protein 2 (map-2), neurofilament protein-heavy chain (nf-h), glial fibrilary acidic protein (gfap) and synaptophysin as well as morphological studies. semiquantitative rt-pcr was also used to evaluate gene expression involved in neurogenesis. results: in the 4+6+4 days the neuronal process were apparently observed. immunocytochemical studies using nerve specific antibodies for proteins such as β- tubulin iii, map-2, nf-h, gfap and synaptophysin showed the presence of these neuronal and astrocyte markers in differentiated cells by camp. evaluation of expression of genes involved in neurogenesis showed that hash1, synaptophysin, β-adrenergic receptor and acetylcholine receptor- which were silent in embryoid bodies - switched on after treatment with camp and/or ra. relative expression of nerve specific genes showed a significant enhancement in expression of synaptophysin, nfm and β-adrenergic receptor during differentiation, which, with the enhancement in camp treated groups were more than those treated with ra and control (p < 0.05). conclusion: in conclusion, this study showed that camp could be a neurogenic agent for human embryonic stem cells differentiation.