The quantity of therapeutic gene products released from genetically engineered cells can be controlled externally at different levels. The widely used approach of controlling expression, however, generally has the disadvantage that chemical substances must be applied for stimulation. An alternative strategy aims at controlling gene products at posttranslational levels such as secretion. The secretion of a therapeutic agent can be regulated if the agent is targeted to the regulated secretory pathway and stored in the secretory granules until its release. In this article we address the question of whether the release of -endorphin, an opioid with a potent analgesic effect, could be induced by electrically stimulating stably transfected Neuro-2a cells. Throughout this study we used the human proopiomelanocortin (POMC) gene, which is the precursor molecule for human -endorphin. We analyzed its subcellular localization and found it in the regulated secretory pathway in Neuro-2a cells. Using electrical field stimulation we were able to identify a stimulation pattern that significantly increased the release of -endorphin-immunoreactive material, although to a limited extent. This result indicates that electrical stimulation of secretion could be used to manipulate the amount of a therapeutic agent released from transplanted cells.
Cell Transplantation publishes original, peer-reviewed research and review articles on the subject of cell transplantation and its application to human diseases. To ensure high-quality contributions from all areas of transplantation, separate section editors and editorial boards have been established. Articles deal with a wide range of topics including physiological, medical, preclinical, tissue engineering, and device-oriented aspects of transplantation of nervous system, endocrine, growth factor-secreting, bone marrow, epithelial, endothelial, and genetically engineered cells, among others. Basic clinical studies and immunological research papers are also featured. To provide complete coverage of this revolutionary field, Cell Transplantation will report on relevant technological advances, and ethical and regulatory considerations of cell transplants. Cell Transplantation is now an Open Access journal starting with volume 18 in 2009, and therefore there will be an inexpensive publication charge, which is dependent on the number of pages, in addition to the charge for color figures. This will allow work to be disseminated to a wider audience and also entitle the corresponding author to a free PDF, as well as prepublication of an unedited version of the manuscript.