David L. Lacey

Bio: David L. Lacey is an academic researcher from Amgen. The author has contributed to research in topics: Osteoclast & Osteoprotegerin. The author has an hindex of 53, co-authored 90 publications receiving 40349 citations. Previous affiliations of David L. Lacey include University of Toronto.

Osteoclast differentiation and activation

Abstract: Osteoclasts are specialized cells derived from the monocyte/macrophage haematopoietic lineage that develop and adhere to bone matrix, then secrete acid and lytic enzymes that degrade it in a specialized, extracellular compartment. Discovery of the RANK signalling pathway in the osteoclast has provided insight into the mechanisms of osteoclastogenesis and activation of bone resorption, and how hormonal signals impact bone structure and mass. Further study of this pathway is providing the molecular basis for developing therapeutics to treat osteoporosis and other diseases of bone loss.

OPGL is a key regulator of osteoclastogenesis, lymphocyte development and lymph-node organogenesis

Abstract: The tumour-necrosis-factor-family molecule osteoprotegerin ligand (OPGL; also known as TRANCE, RANKL and ODF) has been identified as a potential osteoclast differentiation factor and regulator of interactions between T cells and dendritic cells in vitro. Mice with a disrupted opgl gene show severe osteopetrosis and a defect in tooth eruption, and completely lack osteoclasts as a result of an inability of osteoblasts to support osteoclastogenesis. Although dendritic cells appear normal, opgl-deficient mice exhibit defects in early differentiation of T and B lymphocytes. Surprisingly, opgl-deficient mice lack all lymph nodes but have normal splenic structure and Peyer's patches. Thus OPGL is a new regulator of lymph-node organogenesis and lymphocyte development and is an essential osteoclast differentiation factor in vivo.

osteoprotegerin-deficient mice develop early onset osteoporosis and arterial calcification

Abstract: Osteoprotegerin (OPG) is a secreted protein that inhibits osteoclast formation. In this study the physiological role of OPG is investigated by generating OPG-deficient mice. Adolescent and adult OPG-/- mice exhibit a decrease in total bone density characterized by severe trabecular and cortical bone porosity, marked thinning of the parietal bones of the skull, and a high incidence of fractures. These findings demonstrate that OPG is a critical regulator of postnatal bone mass. Unexpectedly, OPG-deficient mice also exhibit medial calcification of the aorta and renal arteries, suggesting that regulation of OPG, its signaling pathway, or its ligand(s) may play a role in the long observed association between osteoporosis and vascular calcification.

Death receptors: signaling and modulation

Abstract: Apoptosis is a cell suicide mechanism that enables metazoans to control cell number in tissues and to eliminate individual cells that threaten the animal's survival. Certain cells have unique sensors, termed death receptors, on their surface. Death receptors detect the presence of extracellular death signals and, in response, they rapidly ignite the cell's intrinsic apoptosis machinery.

Toll-like receptors.

Abstract: The innate immune system in drosophila and mammals senses the invasion of microorganisms using the family of Toll receptors, stimulation of which initiates a range of host defense mechanisms. In drosophila antimicrobial responses rely on two signaling pathways: the Toll pathway and the IMD pathway. In mammals there are at least 10 members of the Toll-like receptor (TLR) family that recognize specific components conserved among microorganisms. Activation of the TLRs leads not only to the induction of inflammatory responses but also to the development of antigen-specific adaptive immunity. The TLR-induced inflammatory response is dependent on a common signaling pathway that is mediated by the adaptor molecule MyD88. However, there is evidence for additional pathways that mediate TLR ligand-specific biological responses.

The NOX Family of ROS-Generating NADPH Oxidases: Physiology and Pathophysiology

Abstract: For a long time, superoxide generation by an NADPH oxidase was considered as an oddity only found in professional phagocytes. Over the last years, six homologs of the cytochrome subunit of the phag...

Osteoclast differentiation and activation

Abstract: Osteoclasts are specialized cells derived from the monocyte/macrophage haematopoietic lineage that develop and adhere to bone matrix, then secrete acid and lytic enzymes that degrade it in a specialized, extracellular compartment. Discovery of the RANK signalling pathway in the osteoclast has provided insight into the mechanisms of osteoclastogenesis and activation of bone resorption, and how hormonal signals impact bone structure and mass. Further study of this pathway is providing the molecular basis for developing therapeutics to treat osteoporosis and other diseases of bone loss.