EPO for the Brain
EPO (Erythropoietin) is a human protein hormone that is predominantly produced in kidneys. It plays a major role in the formation of red blood cells, a process known as erythropoiesis. EPO is commonly used to treat and prevent anaemia in nephrology and cancer patients. Today this pharmaceutical is produced as recombinant human EPO in animal cell cultures, especially in Chinese hamster ovary (CHO) cells. EPO is the leading biopharmaceutical with a world-wide market of about ten billion Euro per year. This hormone has a bad reputation in the public due to its abuse in unethical and illegal doping of athletes.
More recently it was shown that in the human body EPO is made in different tissues when oxygen supply is limited. In these cases the hormone protects these tissues by inhibiting apoptosis, a cell death program that occurs in stress conditions. In this context EPO is a potential treatment for stroke, diabetes-induced eye damage and peripheral nerve injury.
In the human blood, the EPO protein has attached several complex sugar structures which make up to 40% of its molecular mass. These sugar moieties modify half-life and function of the hormone in the human body. A specific form of this complex glycoprotein, the asialo-EPO, can provide tissue protection but does not stimulate red blood cells. Thus, recombinant asialo-EPO is regarded as a safe drug as it has no potential doping activity.
Scientists from the Chair of Plant Biotechnology of the University of Freiburg, Germany, around Dr. Eva Decker and Professor Ralf Reski and from the Freiburg-based biotech company greenovation have genetically engineered the moss Physcomitrella patens in such a way that it now produces recombinant human asialo-EPO in the moss bioreactor. Attachment of the correct sugar moieties to the recombinant protein was proven by Professor Friedrich Altmann from the University of Natural Resources and Life Sciences in Vienna, Austria.
The collaborative work was supported by the German Federal Ministry for Education and Research (BMBF) and by the Baden-Württemberg Stiftung.
The researchers published their results in the current online-version of the Plant Biotechnology Journal.
Juliana Parsons, Friedrich Altmann, Claudia K. Arrenberg, Anna Koprivova, Anna K. Beike, Christian Stemmer, Gilbert Gorr, Ralf Reski, Eva L. Decker (2012): Moss-based production of asialo-erythropoietin devoid of Lewis A and other plant-typical carbohydrate determinants. Plant Biotechnology Journal, DOI: 10.1111/j.1467-7652.2012.00704.x.