Endothelial Progenitor Cells and Heart Disease

Endothelial progenitor cells are stem cells present in the bone marrow, peripheral circulation, and in the blood vessels themselves and are responsible, in large part, for maintaining the health of blood vessel walls and the cardiovascular system. Several studies have attempted to assess differences in levels of endothelial progenitor cells (EPCs) in those with and without heart and circulatory disease and the consensus appears to be that a decreased number and impaired functionality of these stem cells exists in those with metabolic syndrome and cardiovascular disease such as atherosclerosis. Research by Jialal (et al, 2010) examined the levels of EPCs in those with metabolic syndrome but no incidence, as yet, of diabetes or cardiovascular disease. They found that these patients also had lower levels of EPCs, that those cells present had lower clonogenic capacity (decreased colony forming units), and that the EPCs were impaired in terms of their ability to incorporate into tubular structures, thus increasing the risk factors for cardiovascular disease in these patients.

Endothelial Progenitor Cells and Inflammation

EPCs, also sometimes referred to as Circulating Progenitor Cells (CPCs), have also been identified as a key factor in the risk of major adverse cardiac events (MACE) and cardiovascular disease in general, particularly in associating with increased low-grade inflammation. A review of four longitudinal studies by Fadini (et al, 2010), looked at CPC levels along with high-sensitive C-reactive protein (an inflammatory marker) in 1057 patients, most of whom were high risk individuals for CVD, and found a significant relationship between low CPC levels alone, and in combination with higher hsCRP levels, and the accuracy of MACE prediction. The study is helpful in identifying those who are at an increased short term risk of MACE in order to attempt to lower that risk; it may also be helpful in providing a possible treatment strategy in raising CPC levels and lowering circulating hsCRP where possible.

EPCs in Autoimmune Disease

Endothelial progenitor cells are also being studied in light of their potential role in autoimmune diseases such as rheumatoid arthritis which is frequently associated with increased cardiovascular disease risk. This association is due, in part, to anecdotal evidence from patients having stem cell therapy for an unrelated condition who later reported improvements in their arthritis symptoms. Faulty endothelial progenitor cells have now been observed in patients with rheumatoid arthritis and are thought to contribute to the reduced vasculogenesis common with the disease (Szekanecz, et al, 2010). Abnormalities in angiogenesis allow the pannus to develop and grow through increased blood supply, thereby exacerbating joint remodelling, and cartilage and bone destruction leading to RA symptoms (Weber, and de Bandt, 200). Numerous researchers are now investigating the potential for inhibiting angiogenesis whilst improving circulating levels of EPCs in order to promote cardiovascular health.

Continue –> Problems with Stem Cell Heart Therapy
View References