Vascular endothelial growth factor expression in patients suffering from thrombangitis obliterans

Circulating angiogenic factors in patients with thromboangiitis obliterans

Background

Thromboangiitis obliterans (TAO, also known as Buerger's disease) is a non-atherosclerotic inflammatory vascular disease that primarily affects arteries in the extremities of young adult smokers. Since the etiology of TAO is still unknown, therapeutic options are limited. Recent attempts in therapeutic angiogenesis have been promising. Therefore, the aim of our study was to evaluate angiogenic processes and factors including circulating progenitor cells in TAO.

Methodology/Principal Findings

TAO patients with critical limb ischemia and age- and gender-matched nonsmokers and smokers without cardiovascular disease (n = 12 in each group) were enrolled in the study. Flow cytometric analysis of peripheral blood showed significantly decreased levels of circulating CD45^dimCD34⁺ progenitor cells in TAO patients and in smokers compared to nonsmokers. In contrast to both control groups, the proportion of CD45^dimCD34⁺ progenitor cells co-expressing VEGF receptor-2 (VEGFR2) was significantly elevated in TAO patients. Enzyme-linked immunosorbent assay (ELISA) of common angiogenic factors (such as VEGF) did not clearly point to pro- or antiangiogenic conditions in serum or plasma of TAO patients. Serum of TAO patients and controls was evaluated in proliferation, migration (scratch assay) and spheroid sprouting assays using human umbilical vein endothelial cells (HUVECs). Serum of TAO patients exhibited a diminished sprouting capacity of HUVECs compared to both control groups. Proliferation and migration of endothelial cells were impaired after treatment with serum of TAO patients.

Conclusion

Levels of circulating progenitor cells were altered in TAO patients compared to healthy nonsmokers and smokers. Furthermore, serum of TAO patients exhibited an antiangiogenic activity (impaired endothelial cell sprouting, migration and proliferation) on endothelial cells, which may contribute to vascular pathology in this patient population.

Successful Stem Cell Therapy Using Umbilical Cord Blood-Derived Multipotent Stem Cells for Buerger's Disease and Ischemic Limb Disease Animal Model

Buerger's disease, also known as thromboangiitis obliterans, is a nonatherosclerotic, inflammatory, vasoocclusive disease. It is characterized pathologically as a panangiitis of medium and small blood vessels, including both arteries and adjacent veins, especially the distal extremities (the feet and the hands). There is no curative medication or surgery for this disease. In the present study, we transplanted human leukocyte antigen-matched human umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) into four men with Buerger's disease who had already received medical treatment and surgical therapies. After the stem cell transplantation, ischemic rest pain suddenly disappeared from their affected extremities. The necrotic skin lesions were healed within 4 weeks. In the follow-up angiography, digital capillaries were increased in number and size. In addition, vascular resistance in the affected extremities, compared with the preoperative examination, was markedly decreased due to improvement of the peripheral circulation. Because an animal model of Buerger's disease is absent and also to understand human results, we transplanted human UCB-derived MSCs to athymic nude mice with hind limb ischemia by femoral artery ligation. Up to 60% of the hind limbs were salvaged in the femoral artery-ligated animals. By in situ hybridization, the human UCB-derived MSCs were detected in the arterial walls of the ischemic hind limb in the treated group. Therefore, it is suggested that human UCB-derived MSC transplantation may be a new and useful therapeutic armament for Buerger's disease and similar ischemic diseases.

Serum concentrations of vascular endothelial growth factor and monocyte-colony stimulating factor in peripheral arterial disease

Vascular endothelial growth factor (VEGF) strongly promotes angiogenesis, and monocyte-colony stimulating factor (M-CSF) regulates the differentiation, proliferation, and survival of monocytes. Both VEGF and M-CSF are expressed in atherosclerotic lesions. The present study was performed to clarify the role of VEGF and M-CSF in the development of peripheral artery disease (PAD). The serum VEGF and M-CSF concentrations were determined in patients with arteriosclerosis obliterans (ASO) and thromboangitis obliterans (TAO). In both patient groups the serum VEGF concentrations were significantly higher than those in the control subjects. In contrast, the serum M-CSF concentrations in the ASO patients were significantly higher than those in both the TAO patients and control subjects, but there were no differences in the M-CSF concentrations between the TAO patients and control subjects. There was no correlation between the serum concentrations of VEGF and M-CSF. In conclusion, the serum VEGF concentration was increased in ASO and TAO patients, but increased concentration of M-CSF was seen only in ASO patients. These results may reflect a difference between ASO and TAO in disease pathogenesis.