Open Competition Domain Science-M grant from NWO for Catherine Robin

For patients suffering from blood related diseases, the transplantation of healthy donor hematopoietic stem cells (HSCs) is often the only curative therapy. HSCs are the stem cells that produce mature blood cells. Obtaining enough immune compatible HSCs from matched donors (e.g., siblings) or unrelated volunteers remains a great challenge for the clinic. To provide equal opportunities for all patients, there is thus an urgent need for alternative sources of HSCs or ways to produce them in a petri dish (in vitro). To be successful, HSC cultures must allow expansion of HSCs while maintaining their stem cell properties. To date, this has proven to be very difficult, mainly because the process of HSC expansion is still not fully understood.

HSC expansion

Within the developing embryo, HSC expansion mainly occurs during a short time window in the fetal liver. Studying this process is difficult because of the overall complex architecture of the fetal liver and the myriad of processes occurring at the same time. Even in simpler model organisms such as the zebrafish – where HSC expansion occurs in a certain type of tissue called caudal hematopoietic tissue (CHT) – it remains difficult to precisely dissect the cellular and molecular events required for HSC expansion. However, it has become clear that blood vessels play an indispensable part in supporting HSC expansion.

A surrogate niche for HSC expansion

In the lab of Catherine Robin, a unique approach was recently developed by Bart Weijts, who is a senior postdoc in the group. It allows the transformation of a “simple” blood vessel into a blood vessel capable to attract, maintain and expand HSCs in the zebrafish embryo. Bart Weijts explains: “the mere possibility to trick a normal blood vessel into acquiring the properties to support hematopoiesis (i.e. the formation of blood) has stunned us as it goes against our current believe that HSC expansion can only occur during a specific time window at a precise anatomical location. One of the strengths of this method is the ability to directly compare the untransformed blood vessel in an untreated embryo against the transformed blood vessel in a treated embryo. Thereby, we can meticulously study the cellular and molecular properties that are acquired by the blood vessel to support HSC expansion.” With the NWO Science-M project, the group aims to contribute to the development of alternative strategies to produce therapeutical HSCs in vitro.

About NWO-M grants

The NWO Domain Science-M grants are intended for realizing curiosity-driven, fundamental research of high quality and/or scientific urgency. It offers researchers the possibility to elaborate creative and risky ideas to realize scientific innovations that can form the basis for the research themes of the future. A total of 16 out 71 proposals were granted in the M-round 20-3. The proposal of Catherine Robin was ranked 1^st.