ACT’s HG program is in preclinical development investigating the possibility of using the cells to treat cardiovascular disease, stroke, and cancer. The company recently published research in the journal Nature Methods describing a method for generating large numbers of hemangioblasts, which are newly characterized stem cells capable of differentiating into both hematopoietic (blood cell forming) and angiogenic (blood vessel endothelium forming) cells. Endothelial cells comprise the single layer of tissue that lines the interior of the entire circulatory system, from the heart to the smallest capillary. Endothelial cells are involved in control of blood pressure by constricting and dilation of blood vessels; clotting of blood; formation of new blood vessels; and inflammation and swelling. Endothelial cells also control the passage of materials and immune cells (i.e., white blood cells) into and out of the circulation. Some organs, such as the kidney and brain, have highly differentiated endothelial cells that function as filters to keep out unwanted materials and cells.
According to the recently published research, when the HG cells were injected into animals with retinal damage due to diabetes or ischemia-reperfusion injury (lack of adequate blood flow) of the retina, the cells homed to the site of injury and showed robust reparative function of the entire damaged vasculature within 24-48 hours. The cells showed a similar regenerative capacity in animal models of both myocardial infarction (50% reduction in mortality rate) and hind limb ischemia, with restoration of blood flow to near normal levels. These cells were able to generate functional blood vessels in the presence of severe tissue injury as well as in chronic disease states. These cells have a robust vascular reparative ability under what is typically considered very adverse growth conditions making them potentially ideal for treatment of diabetic vascular complications where profound tissue compromise exists and healing is typically severely compromised. The results of the research suggest the possibility of using nature’s early cellular developmental components to restore vascularization and function in patients with vascular disease. An injection of these cells may be able to prevent a patient from having a leg amputated or a patient from dying after a heart attack.
While the cells in the study were tested in animal models, the breakthrough could ultimately benefit many human patients suffering from vascular disease. Advanced Cell Technology plans to file an IND with the Food and Drug Administration for the first clinical application of these HG cells by the end of 2008.