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Source: Seminars in Hematology - April 1, 2017 Category: Hematology Source Type: research
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Source: Seminars in Hematology - December 31, 2016 Category: Hematology Source Type: research
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Source: Seminars in Hematology - December 31, 2016 Category: Hematology Source Type: research
Table of Contents
(Source: Seminars in Hematology)
Source: Seminars in Hematology - December 31, 2016 Category: Hematology Source Type: research
Molecular mechanisms underlying lineage bias in aging hematopoiesis
Although hematopoietic stem cells (HSCs) have traditionally been thought to possess the ability to give rise to all the mature cell types in the hematopoietic system, this conception of hematopoiesis was typically based on evaluation of hematopoietic output from large numbers of HSCs using transplantation models. More recent studies evaluating HSCs at the clonal or near-clonal level, both in transplantation studies and during in situ hematopoiesis, have established that individual HSCs can exhibit lineage bias, giving rise to myeloid-biased, lymphoid-biased, or more balanced differentiation, with the prop ortion of myel...
Source: Seminars in Hematology - November 18, 2016 Category: Hematology Authors: Harold K. Elias, David Bryder, Christopher Y. Park Source Type: research
Accumulation of DNA damage in the aged hematopoietic stem cell compartment
Aging is associated with loss of functional potential of multiple tissue systems, and there has been significant interest in understanding how tissue specific cells contribute to this decline. DNA damage accumulation has been widely associated with aging in differentiated cell types. However, tissue specific stem cells were once thought to be a geno-protected population, as damage accrued in a stem cell population has the potential to be inherited by differentiated progeny as well as propagated within the stem cell compartment through self-renewal divisions. (Source: Seminars in Hematology)
Source: Seminars in Hematology - November 17, 2016 Category: Hematology Authors: Isabel Beerman Tags: 54/1 Aging and Hematopoiesis Source Type: research
Hematopoiesis in Aging: Current Concepts and Challenges
One of the major achievements of medicine in the 20th century has been the dramatic extension of life expectancy [1], which is largely attributable to better access to, and improvements in, medical care [2]. While this represents a welcome change, it has also resulted in an increased prevalence of age-related degenerative disorders as well as a rise in the incidence of age-related cancers [3 –5]. Recognition of these trends has led to increasing efforts to better understand the molecular mechanisms of aging in both humans as well as model organisms. (Source: Seminars in Hematology)
Source: Seminars in Hematology - November 3, 2016 Category: Hematology Authors: Christopher Y. Park Tags: 54/1 Aging and Hematopoiesis Source Type: research
Rejuvenation of aged hematopoietic stem cells
Until recently, there was broad consensus in the stem cell aging field that the phenotype of aged hematopoietic stem cells (HSCs) is fixed —dominated by cell-intrinsic regulatory mechanisms that cannot be altered by pharmacological or genetic means. The conventional thinking was that HSC aging could not be reverted by therapeutic intervention. This paradigm has started to shift dramatically, primarily because hallmarks of aged HSCs h ave been successfully reverted by distinct experimental approaches by multiple laboratories. (Source: Seminars in Hematology)
Source: Seminars in Hematology - October 23, 2016 Category: Hematology Authors: Novella Guidi, Hartmut Geiger Source Type: research
The Epigenetic Basis of Hematopoietic Stem Cell Aging
Highly proliferative tissues such as the gut, skin and bone marrow lose millions of cells each day to normal attrition and challenge from different biological adversities. To achieve a lifespan beyond the longevity of individual cell types, tissue-specific stem cells sustain these tissues throughout the life of a human. For example, the lifespan of erythrocytes is about 100 days and adults make about two million new erythrocytes every second. A small pool of hematopoietic stem cells (HSCs) in the bone marrow is responsible for the lifetime maintenance of these populations. (Source: Seminars in Hematology)
Source: Seminars in Hematology - October 23, 2016 Category: Hematology Authors: Ashley Kramer, Grant A. Challen Tags: 54/1 Aging and Hematopoiesis Source Type: research
Rejuvenation of aged HSCs
Until recently, there was broad consensus in the stem cell aging field that the phenotype of aged HSCs is fixed – dominated by cell-intrinsic regulatory mechanisms that cannot be altered by pharmacological or genetic means. The conventional thinking was that HSC aging could not be reverted by therapeutic intervention. This paradigm has started to shift dramatically, in large part because hallmarks of aged H SCs have been successfully reverted by distinct experimental approaches by multiple laboratories. (Source: Seminars in Hematology)
Source: Seminars in Hematology - October 23, 2016 Category: Hematology Authors: Novella Guidi, Hartmut Geiger Source Type: research
Age-associated changes in human hematopoietic stem cells
Aging has a broad impact on the function of the human hematopoietic system. This review will focus primarily on the effect of aging on the human hematopoietic stem cell (HSC) population. With age, even though human HSCs increase in number, they have decreased self-renewal capacity and reconstitution potential upon transplantation. As a population, human HSCs become more myeloid-biased in their differentiation potential. This is likely due to the human HSC population becoming more clonal with age, selecting for myeloid-biased HSC clones. (Source: Seminars in Hematology)
Source: Seminars in Hematology - October 19, 2016 Category: Hematology Authors: Wendy W. Pang, Stanley L. Schrier, Irving L. Weissman Source Type: research
Clonal Hematopoiesis
Cancer results from multistep pathogenesis, yet the pre-malignant states that precede the development of many hematologic malignancies have been difficult to identify. Recent genomic studies of blood DNA from tens of thousands of people have revealed the presence of remarkably common, age-associated somatic mutations in genes associated with hematologic malignancies. These somatic mutations drive the expansion from a single founding cell to a detectable hematopoietic clone. Owing to the admixed nature of blood that provides a sampling of blood cell production throughout the body, clonal hematopoiesis is a rare view into th...
Source: Seminars in Hematology - October 19, 2016 Category: Hematology Authors: Max Jan, Benjamin L. Ebert, Siddhartha Jaiswal Tags: 54/1 Aging and Hematopoiesis Source Type: research
Lymphocyte generation and population homeostasis throughout life
Immune aging is a multi-faceted process that manifests as reduced competence to fight infections and malignant cells as well as diminished tissue repair, unprovoked inflammation and increased autoreactivity. The aging adaptive immune system, with its high complexity in functional cell subpopulations and diversity of B and T cell receptors, has to cope with the challenge of maintaining homeostasis while responding to exogenous stimuli and compensating for reduced generative capacity. With thymic involution, na ïve T cells begin to function as quasi-stem cells and maintain the compartment through peripheral homeostatic prol...
Source: Seminars in Hematology - October 18, 2016 Category: Hematology Authors: Rolando E. Yanes, Claire E. Gustafson, Cornelia M. Weyand, J örg J. Goronzy Tags: 54/1 Aging and Hematopoiesis Source Type: research
The aging hematopoietic stem cell niche: Phenotypic and functional changes and mechanisms that contribute to hematopoietic aging
In the classical model of hematopoiesis, HSCs sit at the apex of a developmental hierarchy. HSCs are self-renewing and give rise to all mature myeloid and lymphoid cell lineages. Although they are multipotent and self-renewing, HSCs are relatively quiescent in order to maintain an indefinite pool of HSCs [1]. The pool of HSCs contains multipotent progenitors (MPP), short-term HSCs (ST-HSCs), and long-term HSCs (LT-HSCs). The balance of HSC self-renewal with multi-lineage differentiation is critical for hematopoietic tissue homeostasis [2]. (Source: Seminars in Hematology)
Source: Seminars in Hematology - October 18, 2016 Category: Hematology Authors: Sarah E. Latchney, Laura M. Calvi Source Type: research
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Source: Seminars in Hematology - September 30, 2016 Category: Hematology Source Type: research
