Tobacco-Produced Hormone Protects Kidney Cells from Damage

Eythropoietin (EPO) is a glycoprotein hormone that controls red blood cell production. EPO acts as a general tissue-protective agent that has the potential to treat numerous diseases and injuries, including stroke, myocardial infraction and spinal cord injury. It is also involved in the brain's response to neuronal damage and in wound healing.

Recombinant EPO is an important biopharmaceutical that is used extensively in anemia caused by kidney failure, chemotherapy and AIDS. Unfortunately, cell cultures are unlikely to meet the anticipated market demands for EPO because of high production costs. The use of plants as expression systems may address these limitations to enable practical, cost-effective delivery of EPO in tissue injury prevention therapeutics.

A team of researchers from Canada developed transgenic tobacco plants accumulating high levels of EPO (up to 0.05% of total soluble protein in leaves). The scientists found that higher accumulation levels of EPO can be achieved in the endoplasmic reticulum than in the apoplast or chloroplasts. More importantly, the team also demonstrated that plant-derived EPO had enhanced receptor-binding affinity and was able to protect kidney epithelial cells from cytokine-induced death in vitro. The tobacco-produced EPO does not possess the potentially harmful side-effects associated with excessive haematopoietic activity.

The paper published by the Plant Biotechnology Journal is available for download at http://dx.doi.org/10.1111/j.1467-7652.2008.00389.x