The role of ANGPTL7 in hematopoietic stem and progenitor cells has been identified by GIBH scientists

The autologous-allogeneic hematopoietic cell transplantation has been developed for decades, and numerous attempts have been made to expand the HSCs population in vitro and in vivo. Agiopoietin-like proteins belong to a 7-member family of secreted glycoproteins that share sequence homology with angiopoietins, which are important modulators of angiogenesis. Several Angptl family proteins promote the expansion of murine and human HSPCs in vitro and ex vivo. Angiopoietin-like 7 (Angptl7) in the ECM of the trabecular meshwork plays an important role in the deposition and organization of the matrix of the outflow tissue. Recently, the research group led by Prof Peng Li found that ANGPTL7 stimulated the proliferation of human HSPCs ex vivo. In addition, the team also uncovered that Angptl7, which was secreted by murine bone marrow SSEA4+ mesenchymal cells, stimulated expansion of murine HSCs ex vivo. Furthermore, Prof Li and his team generated Angptl7 knockout mice and revealed that Angptl7 is essential for HSPC repopulation in a non-cell autonomous manner.

Overall, Prof Li and his team have indicated that Angptl7 was indispensable for BM microenvironment to support HSC repopulation in mice and identified ANGPTL7 as a growth factor for human HSCs. These findings suggest that ANGPTL7 may be useful in ex vivo expansion of human HSC for transplantation therapy or gene therapy protocol in the future.

These works have been published on line by Journal of Hematology & Oncology (2015) 8:7 (DOI 10.1186/s13045-014-0102-4) and Haematologica 2015; 100(5) (doi:10.3324/haematol.2014.118612). This study was supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China, the National Basic Research Program of China (973 Program), and the Equipment Function Development & Technology Innovation Project of Chinese Academy of Sciences.