User login
University Health Network
Results of a study published in Science challenge traditional ideas about how blood is made.
The findings suggest hematopoiesis does not occur through a gradual process consisting of multipotent, oligopotent, and unilineage progenitor stages.
Rather, hematopoietic stem cells (HSCs) mature into different types of blood cells quickly, and the process differs between early human development (fetal liver HSCs) and adulthood (HSCs from bone marrow).
The research indicates “that the whole classic ‘textbook’ view we thought we knew doesn’t actually even exist,” said study investigator John Dick, PhD, of Princess Margaret Cancer Centre in Toronto, Ontario, Canada.
He and his colleagues mapped the lineage potential of nearly 3000 single cells from 33 different populations of HSCs obtained from human blood samples taken at various life stages and ages.
The team’s discoveries build on research published in Science in 2011. In that paper, Dr Dick and his colleagues described isolating an HSC in its purest form—as a single cell capable of regenerating the entire blood system.
“Four years ago, when we isolated the pure stem cell, we realized we had also uncovered populations of stem-cell like ‘daughter’ cells that we thought at the time were other types of stem cells,” Dr Dick said.
“When we burrowed further to study these ‘daughters,’ we discovered they were actually already mature blood lineages. In other words, lineages that had broken off almost immediately from the stem cell compartment and had not developed downstream through the slow, gradual ‘textbook’ process.”
“So in human blood formation, everything begins with the stem cell, which is the executive decision-maker quickly driving the process that replenishes blood at a daily rate that exceeds 300 billion cells.”
The investigators believe this work could help advance the manufacture of blood cells in the lab, and it should aid the study of blood disorders.
“Our discovery means we will be able to understand far better a wide variety of human blood disorders and diseases—from anemia . . . to leukemia,” Dr Dick said. “Think of it as moving from the old world of black-and-white television into the new world of high-definition.” 
University Health Network
Results of a study published in Science challenge traditional ideas about how blood is made.
The findings suggest hematopoiesis does not occur through a gradual process consisting of multipotent, oligopotent, and unilineage progenitor stages.
Rather, hematopoietic stem cells (HSCs) mature into different types of blood cells quickly, and the process differs between early human development (fetal liver HSCs) and adulthood (HSCs from bone marrow).
The research indicates “that the whole classic ‘textbook’ view we thought we knew doesn’t actually even exist,” said study investigator John Dick, PhD, of Princess Margaret Cancer Centre in Toronto, Ontario, Canada.
He and his colleagues mapped the lineage potential of nearly 3000 single cells from 33 different populations of HSCs obtained from human blood samples taken at various life stages and ages.
The team’s discoveries build on research published in Science in 2011. In that paper, Dr Dick and his colleagues described isolating an HSC in its purest form—as a single cell capable of regenerating the entire blood system.
“Four years ago, when we isolated the pure stem cell, we realized we had also uncovered populations of stem-cell like ‘daughter’ cells that we thought at the time were other types of stem cells,” Dr Dick said.
“When we burrowed further to study these ‘daughters,’ we discovered they were actually already mature blood lineages. In other words, lineages that had broken off almost immediately from the stem cell compartment and had not developed downstream through the slow, gradual ‘textbook’ process.”
“So in human blood formation, everything begins with the stem cell, which is the executive decision-maker quickly driving the process that replenishes blood at a daily rate that exceeds 300 billion cells.”
The investigators believe this work could help advance the manufacture of blood cells in the lab, and it should aid the study of blood disorders.
“Our discovery means we will be able to understand far better a wide variety of human blood disorders and diseases—from anemia . . . to leukemia,” Dr Dick said. “Think of it as moving from the old world of black-and-white television into the new world of high-definition.”
University Health Network
Results of a study published in Science challenge traditional ideas about how blood is made.
The findings suggest hematopoiesis does not occur through a gradual process consisting of multipotent, oligopotent, and unilineage progenitor stages.
Rather, hematopoietic stem cells (HSCs) mature into different types of blood cells quickly, and the process differs between early human development (fetal liver HSCs) and adulthood (HSCs from bone marrow).
The research indicates “that the whole classic ‘textbook’ view we thought we knew doesn’t actually even exist,” said study investigator John Dick, PhD, of Princess Margaret Cancer Centre in Toronto, Ontario, Canada.
He and his colleagues mapped the lineage potential of nearly 3000 single cells from 33 different populations of HSCs obtained from human blood samples taken at various life stages and ages.
The team’s discoveries build on research published in Science in 2011. In that paper, Dr Dick and his colleagues described isolating an HSC in its purest form—as a single cell capable of regenerating the entire blood system.
“Four years ago, when we isolated the pure stem cell, we realized we had also uncovered populations of stem-cell like ‘daughter’ cells that we thought at the time were other types of stem cells,” Dr Dick said.
“When we burrowed further to study these ‘daughters,’ we discovered they were actually already mature blood lineages. In other words, lineages that had broken off almost immediately from the stem cell compartment and had not developed downstream through the slow, gradual ‘textbook’ process.”
“So in human blood formation, everything begins with the stem cell, which is the executive decision-maker quickly driving the process that replenishes blood at a daily rate that exceeds 300 billion cells.”
The investigators believe this work could help advance the manufacture of blood cells in the lab, and it should aid the study of blood disorders.
“Our discovery means we will be able to understand far better a wide variety of human blood disorders and diseases—from anemia . . . to leukemia,” Dr Dick said. “Think of it as moving from the old world of black-and-white television into the new world of high-definition.”