Journal of Stem Cell Research & Therapy

Abstract

Influence of Donor Age and Passage Number on Angiogenic Activity in Human Adipose-Derived Stem Cell-Conditioned Media

Takahiro Nakamura, Tomohiko Kazama, Yuki Nagaoka, Yasuji Inamo, Hideo Mugishima, Shori Takahashi and Taro Matsumoto

Introduction: Adipose-derived stem/stromal cells (ASCs) are considered a promising cell source for therapeutic angiogenesis because the cells can be prepared following a minimally invasive procedure and because they secrete a variety of angiogenic cytokines. In the present study, the influence of donor age and passage number on angiogenic activity of ASC-conditioned media (ASC-CM) was examined.
Methods: Human ASCs (donor age, 5 months to 82 years; n = 10) were cultured, and ASC-CM were collected at passages 2, 4, and 6. The angiogenic activity of ASC-CM was evaluated with the tube formation assay using a system in which human umbilical vein endothelial cells (HUVECs) and fibroblasts were co-cultured. The concentrations of vascular endothelial growth factor-A (VEGF-A) and hepatocyte growth factor (HGF) in each ASC-CM were measured using an enzyme-linked immunosorbent assay.
Results: A donor age over 60 years affected the proliferative capacity of ASCs at passage 4 and later. ASCCM significantly enhanced HUVEC tube formation, and this response was not influenced by donor age. ASC-CM at passage 6 showed a lower tube formation capacity compared to ASC-CM at passage 4, although the capacity was still equivalent to the positive control (medium containing10 ng/mL VEGF-A). A donor age over 26 years affected VEGF-A but not HGF levels in ASC-CM, although we found no direct correlation between VEGF-A/HGF levels and the tube formation capacity.
Conclusion: Our results demonstrate a passage number-dependent but a donor age-independent decline in the angiogenic activity of ASC-CM.