title: Angiopoietin-like-2 and -3 act through their coiled-coil domains to enhance survival and replating capacity of human cord blood hematopoietic progenitors.
abstract: Several angiopoietin-like (ANGPTL) molecules have been implicated in enhancement of ex-vivo expansion of murine and human (hu) hematopoietic stem cells, but there are no reports on hematopoietic progenitor cells (HPCs). We assessed purified recombinant endotoxin-free hu ANGPTL-2 Coiled-Coil (CC), -3, -3CC, -3 fibrinogen-like domain (FLD), -4, -4CC, -5CC, -6 and -7 for effects on proliferation and survival of HPCs from hu cord blood (CB). None of the ANGPTL molecules stimulated CB HPC proliferation, or enhanced or inhibited colony formation of CB HPC stimulated by various growth factors. However, ANGPTL-2CC, -3, and -3CC significantly enhanced survival of HPC (CFU-GM, BFU-E, CFU-GEMM) subjected to delayed addition of growth factors. Survival enhancing effects of ANGPTL-3 were neutralized by purified anti-ANGPTL-3, but not by anti-ANGPTL-4, -6, or -7. ANGPTL-2CC, -3, and -3CC, but not -4, -6, or -7 also enhanced replating capacity of single CB CFU-GEMM colonies, an estimate of the self-renewal capabilities of HPCs, by greater than 2 fold. Effects of at least ANGPTL-3CC may in part be mediated through phosphorylation of ERK. The ANGPTL molecules did not influence ex-vivo expansion of hu CB CD34(+) cells, alone, or in combination with SCF, TPO, Flt3-ligand, with or without IL-3. Thus, among ANGPTL family members, ANGPTL-2 and -3 had enhancing activities on human HPC survival and replating activity, effects requiring the CC domain of the ANGPTL molecules. This information is of relevance to hu HPC regulation.
authors: Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202-5181, USA. hbroxmey@iupui.edu
authors: Hal E
authors: HE
authors: Broxmeyer
authors: Edward F
authors: EF
authors: Srour
authors: Scott
authors: S
authors: Cooper
authors: Carrie T
authors: CT
authors: Wallace
authors: Giao
authors: G
authors: Hangoc
authors: Byung-Soon
authors: BS
authors: Youn
mesh_terms: D000091302:Angiopoietin-Like Protein 2; D000091303:Angiopoietin-Like Protein 3; D000075802:Angiopoietin-like Proteins; D042682:Angiopoietins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology; D057134:Antibodies, Neutralizing / Q000494:pharmacology; D018952:Antigens, CD34 / Q000096:biosynthesis; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004921:Erythropoietin / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology*
chemical_list: C485792:ANGPTL2 protein, human; C479896:ANGPTL3 protein, human; D000091302:Angiopoietin-Like Protein 2; D000091303:Angiopoietin-Like Protein 3; D000075802:Angiopoietin-like Proteins; D042682:Angiopoietins; D057134:Antibodies, Neutralizing; D018952:Antigens, CD34; D036341:Intercellular Signaling Peptides and Proteins; D011994:Recombinant Proteins; D004921:Erythropoietin