Hereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease, is a rare genetic disorder, known for its endothelial dysplasia causing vessel malformations, severe nose bleeds and... Show moreHereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease, is a rare genetic disorder, known for its endothelial dysplasia causing vessel malformations, severe nose bleeds and internal bleedings. In the majority of patients mutations are found in genes belonging to the TGFβ superfamily, causing a disbalance in the TGFβ signaling pathway by haploinsufficiency of the remaining functional protein. In this thesis we studied different aims and approaches to influence HHT1-MNC homing and differentiation to restore their contribution to tissue repair. In various experimental methods inducing ischemic and/or direct tissue damage, we aimed to improve tissue repair in the Eng+/- mice. Using DPP4 inhibition, we increased the SDF1-CXCR4 homing mechanism, to restore the impaired homing capacity of the HHT1-MNCs. Furthermore, we focused on correcting the M1/M2 differentiation in Eng+/- mice. Via use of the BMP receptor inhibitor LDN we aimed to restore the skewed BMP/TGFβ signaling; stimulating the TGFβ pathway signaling to induce M2 differentiation. We concluded that DPP4 inhibition can be used to improve the HHT1 immune system and tissue repair, and is best used in concert with other drugs or therapies that stimulate cardiac or tissue repair, like anti-coagulants or cell therapy. Show less
Chapter 2 investigated the generation of knockin mESC line in order to study the biallelic distribution of Nanog expression at the protein level. Chapter 3 investigated the generation of human ECs... Show moreChapter 2 investigated the generation of knockin mESC line in order to study the biallelic distribution of Nanog expression at the protein level. Chapter 3 investigated the generation of human ECs from hESCs using a spin-EB differentiation approach. Chapter 4 described the rst derivation of three human iPS cell lines in the Netherlands: two from healthy individuals and one from a patient with HHT. Chapter 5 investigated the use of hiPSC-EC as a model for studying HHT1 in vitro.Chapter 6 investigated the role of Gja5 that encodes for the gap junction protein Cx40 in the development of AVMs in the HHT2 mouse model. Show less
