Hyaluronan is synthesized by primitive hemopoietic cells, participates in their lodgment at the endosteum following transplantation, and is involved in the regulation of their proliferation and differentiation in vitro by Susan K. Nilsson, David N. Haylock, Hayley M. Johnston, Teresa Occhiodoro, Tracey J. Brown, and Paul J. Simmons Blood Volume 101(3):856-862 February 1, 2003 ©2003 by American Society of Hematology

HA expression on murine BM HSCs HA expression on murine BM HSCs.(A) Sca-1 and Kit expression characteristics of Lin−murine BM cells; R1 sort region for HSCs. (B) HA expression on all R1 HSCs (gray line) as detected using HABP. (C) Control (Red 670 alone) for HA expression on Lin−Rhdull ce... HA expression on murine BM HSCs.(A) Sca-1 and Kit expression characteristics of Lin−murine BM cells; R1 sort region for HSCs. (B) HA expression on all R1 HSCs (gray line) as detected using HABP. (C) Control (Red 670 alone) for HA expression on Lin−Rhdull cells. (D) HABP binding to Lin−Rhdull cells. (E) HABP binding to Lin−Rhdull cells following hyaluronidase pretreatment. The percentages represent the proportion of positive cells. Susan K. Nilsson et al. Blood 2003;101:856-862 ©2003 by American Society of Hematology

HA synthase expression in murine BM subpopulations HA synthase expression in murine BM subpopulations.Has-1, Has-2, and Has-3 PCR products were specifically amplified under RT-PCR conditions described in “Materials and methods.” BMS2 stromal cell line: positive control known to express HA synthases. HA synthase expression in murine BM subpopulations.Has-1, Has-2, and Has-3 PCR products were specifically amplified under RT-PCR conditions described in “Materials and methods.” BMS2 stromal cell line: positive control known to express HA synthases. Susan K. Nilsson et al. Blood 2003;101:856-862 ©2003 by American Society of Hematology

HA expression on human CB progenitors HA expression on human CB progenitors.Scatter properties of Lin− CB cells. HA expression on human CB progenitors.Scatter properties of Lin− CB cells. (Panels A,C,E,G) CD34 and CD38 expression of maturing progenitors: R1 to R4, respectively (Panels B,D,F,H). HA expression on each progenitor subpopulation (gray line) as detected using HABP. Susan K. Nilsson et al. Blood 2003;101:856-862 ©2003 by American Society of Hematology

HA synthase expression in human CB subpopulations HA synthase expression in human CB subpopulations.Has-1, Has-2, and Has-3 PCR products were specifically amplified under RT-PCR conditions described in “Materials and methods.” Human stroma: positive control known to express HA synthases. HA synthase expression in human CB subpopulations.Has-1, Has-2, and Has-3 PCR products were specifically amplified under RT-PCR conditions described in “Materials and methods.” Human stroma: positive control known to express HA synthases. Susan K. Nilsson et al. Blood 2003;101:856-862 ©2003 by American Society of Hematology

HA synthesis by human HPCs HA synthesis by human HPCs.HA synthesis by CB CD34+CD38− cells following 60 hours in culture demonstrated using Superose 12 size exclusion chromatography by the difference in [3H] counts eluted at fractions 15 to 25 before digestion withStreptomyces hyaluro... HA synthesis by human HPCs.HA synthesis by CB CD34+CD38− cells following 60 hours in culture demonstrated using Superose 12 size exclusion chromatography by the difference in [3H] counts eluted at fractions 15 to 25 before digestion withStreptomyces hyaluronidase (○) versus total digestion of high-molecular-weight material to the enzymatic degradation products tetrasaccharides and hexasaccharides (●). The 3 peaks represent HA within the cell supernatant. The molecular weights of synthesized HA were determined by comparison with eluted purified HA of known molecular size. For calculation of recovery, counts were taken as significant when they were more than 3 SDs above the mean background (n = 15). Susan K. Nilsson et al. Blood 2003;101:856-862 ©2003 by American Society of Hematology

Representative experiment of HA-HABP binding negatively regulating HSC proliferation and differentiation.(A) Number of progenitors produced per 320 CD34+CD38− CB HSCs seeded in serum-free culture for 6 days with various concentrations of HABP. (B) CD15 expr... Representative experiment of HA-HABP binding negatively regulating HSC proliferation and differentiation.(A) Number of progenitors produced per 320 CD34+CD38− CB HSCs seeded in serum-free culture for 6 days with various concentrations of HABP. (B) CD15 expression of cells cultured in various concentrations of HABP in Figure 6A. (C-F) CD34 and CD38 expression of cells cultured in various HABP concentrations in Figure 6A. The percentage in each quadrant represents the proportion of cultured cells expressing the particular phenotype. The number in parentheses represents the total number of CD34+CD38− cells in the culture compared with the original 320 cells seeded. Susan K. Nilsson et al. Blood 2003;101:856-862 ©2003 by American Society of Hematology