Lymphedema is the accumulation of lymphatic fluid in the interstitial spaces caused by a defect in the lymphatic vascular system. It is marked by edema, chronic inflammation, and fibrosis, which can lead to painful, disfiguring abnormalities and serious infection. While primary lymphedema occurs infrequently on a hereditary or idiopathic basis, secondary lymphedema is common worldwide, primarily due to infectious disease or radical surgery and radiotherapy for cancer. Despite a continuous increase in the incidence of lymphedema, current therapeutic options are limited to palliative surgical and conservative techniques. Recent progress toward understanding the molecular mechanisms of new lymphatic vessel growth has shed new light on the treatment of lymphedema. Growth factor therapy has yet to show clear clinical benefits in treatment of diseases characterized by deficient arterial or venous vasculature; using a similar strategy to approach lymphedema may face similar hurdles. Recent groundbreaking studies have demonstrated that introduction of pluripotency-associated transcription factors can reprogram somatic cells into embryonic stem (ES)-like cells, referred to as induced pluripotent stem cells (iPSCs). The discovery of iPSCs has presented the opportunity for ES cell-equivalent stem cells to be used therapeutically without concerns about immunologic incompatibility and ethical controversy. Recently, we have developed protocols to efficiently differentiate human iPSCs and ESCs into lymphatic endothelial cell (LEC) lineages. We therefore propose to study the therapeutic effects of hPSC-derived LECs, and their bioengineered derivatives with extracellular matrix-mimicking nanomatrix, on experimental lymphedema.
In aim 1, we will develop a novel clinically compatible method to differentiate hPSCs into the lymphatic endothelial lineage and isolate pure hPSC-LECs.
In aim 2, we will engineer hPSC-derived LECs with peptide amphiphile-based nanomatrix gel for enhancing cell survival and function.
In aim 3, we will determine the effects of hPSC-derived LECs and their bioengineered constructs on experimental lymphedema. We anticipate that the results of the proposed experiments will yield new insight into the role of novel stem cell-based therapy for treating lymphedema.
We have developed methods to differentiate human pluripotent stem cells (hPSCs), including embryonic stem cells and induced pluripotent stem cells, into the lymphatic endothelial cell (LEC) lineage. In this proposal, we will seek to investigate the therapeutic effects and lymphatic neovascularization effects of hPSC-derived LECs and their bioengineered derivatives on experimental lymphedema. Ultimately this study aims to develop effective hPSC-based therapy for treatment of human lymphedema.