Asialo-rhuEPO, a non-hematopoietic recombinant human erythropoietin (EPO) derivative lacking sialic acid, has been reported to display broad tissue-protective effects against damage triggered by ischemia/reperfusion (I/R), hypoxia or cytotoxic agents in the brain, the heart, the kidneys and the liver. However, attempts to translate its protective effects into clinical practice is hampered by unavailability of suitable expression system and its costly and limit production from expensive mammalian cell-made EPO (rhuEPOM) by enzymatic desialylation. It is known that plants can synthesize complex N-glycans similar to mammals, but lack sialylating capacity. We hypothesized that the plant-based expression system lacking sialylating capacity while possessing ability to synthesize complex N-glycans can be utilized to produce asialo-rhuEPO. Our previous studies have demonstrated that co-expression of human EPO and ?1,4-galactosyltransferase (GalT) genes in tobacco plants could produce soluble asialo-rhuEPO. Purified plant-produced asialo-rhuEPO (asialo- rhuEPOP) from transgenic tobacco leaves was found to have better cytoprotective effect than rhuEPOM in protecting neuronal-like mouse neuroblastoma cells, murine HL-1 cardiomyocytes and pancreatic ?-cells from staurosporine-induced cell death. These milestone studies have set the stage for the current proposed research activities. This SC1 application is aimed at: a. studying in vivo neuroprotective properties of asialo-rhuEPOP in a mouse model of I/R injury; b. characterizing its general pharmacological characteristics as a necessary step toward clinical translation; c. further improving its expression levels in plants. The proposed research activities would help developing asialo-rhuEPOP as a drug for the treatment of stroke patients. Furthermore, these studies will lay a solid foundation for us to compete for non-SCORE support for studying tissue-protective effects and action mechanisms of asialo-rhuEPOP in various animal models of tissue injury and clinical trials. The proposed project will also provide training opportunities for our students who will be engaged in hypothesis-driven research to prepare themselves with scientific competency and laboratory experience either to work in the pharmaceutical/biotechnology industries, or to pursue advanced studies.
There is an acute need to develop tissue-protective drugs to prevent or/and protect tissue/cell damages caused by ischemia/reperfusion, hypoxia or cytotoxic agents in the brain, the heart, the pancreas and the kidneys. Plant-based expression system can be used to produce a non-hematopoietic EPO derivative asialo-rhuEPO, which could be used as a neuroprotective agent for protecting brain damage from ischemia/reperfusion as well as a broad-spectrum cytoprotective agent for preventing and protecting diverse tissue injuries.
|Arthur, Elena; Kittur, Farooqahmed S; Lin, Yuan et al. (2017) Plant-Produced Asialo-Erythropoietin Restores Pancreatic Beta-Cell Function by Suppressing Mammalian Sterile-20-like Kinase (MST1) and Caspase-3 Activation. Front Pharmacol 8:208|