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Archives of Biochemistry and Biophysics Nov 2010T cells and B cells produce large amounts of cytokines which regulate bone resorption and bone formation. These factors play a critical role in the regulation of bone... (Review)
Review
T cells and B cells produce large amounts of cytokines which regulate bone resorption and bone formation. These factors play a critical role in the regulation of bone turnover in health and disease. In addition, immune cells of the bone marrow regulate bone homeostasis by cross-talking with bone marrow stromal cells and osteoblastic cells via cell surface molecules. These regulatory mechanisms are particularly relevant for postmenopausal osteoporosis and hyperparathyroidism, two common forms of bone loss caused primarily by an expansion of the osteoclastic pool only partially compensated by a stimulation of bone formation. This article describes the cytokines and immune factors that regulate bone cells, the immune cells relevant to bone, examines the connection between T cells and bone in health and disease, and reviews the evidence in favor of a link between T cells and the mechanism of action of estrogen and PTH in bone.
Topics: Animals; Bone and Bones; Cytokines; Humans; Immune System; Osteoporosis, Postmenopausal; Parathyroid Hormone
PubMed: 20599675
DOI: 10.1016/j.abb.2010.05.027 -
Biotechnology and Bioengineering Jan 2020Reliably producing functional in vitro organ models, such as organ-on-chip systems, has the potential to considerably advance biology research, drug development time,... (Review)
Review
Reliably producing functional in vitro organ models, such as organ-on-chip systems, has the potential to considerably advance biology research, drug development time, and resource efficiency. However, despite the ongoing major progress in the field, three-dimensional bone tissue models remain elusive. In this review, we specifically investigate the control of perfusion flow effects as the missing link between isolated culture systems and scientifically exploitable bone models and propose a roadmap toward this goal.
Topics: Animals; Bioreactors; Bone and Bones; Cell Culture Techniques; Equipment Design; Humans; Lab-On-A-Chip Devices; Models, Biological; Tissue Array Analysis; Tissue Engineering
PubMed: 31531968
DOI: 10.1002/bit.27171 -
Biological Reviews of the Cambridge... Feb 2018Bone formation, for example during bone remodelling or fracture repair, requires mature osteoblasts to deposit bone with remarkable spatial precision. As osteoblast... (Review)
Review
Bone formation, for example during bone remodelling or fracture repair, requires mature osteoblasts to deposit bone with remarkable spatial precision. As osteoblast precursors derive either from circulation or resident stem cell pools, they and their progeny are required to migrate within the three-dimensional bone space and to navigate to their destination, i.e. to the site of bone formation. An understanding of this process is emerging based on in vitro and in vivo studies of several vertebrate species. Receptors on the osteoblast surface mediate cell adhesion and polarization, which induces osteoblast migration. Osteoblast migration is then facilitated along gradients of chemoattractants. The latter are secreted or released proteolytically by several cell types interacting with osteoblasts, including osteoclasts and vascular endothelial cells. The positions of these cellular sources of chemoattractants in relation to the position of the osteoblasts provide the migrating osteoblasts with tracks to their destination, and osteoblasts possess the means to follow a track marked by multiple chemoattractant gradients. In addition to chemotactic cues, osteoblasts sense other classes of signals and utilize them as landmarks for navigation. The composition of the osseous surface guides adhesion and hence migration efficiency and can also provide steering through haptotaxis. Further, it is likely that signals received from surface interactions modulate chemotaxis. Besides the nature of the surface, mechanical signals such as fluid flow may also serve as navigation signals for osteoblasts. Alterations in osteoblast migration and navigation might play a role in metabolic bone diseases such as osteoporosis.
Topics: Animals; Bone and Bones; Osteoblasts; Vertebrates
PubMed: 28631442
DOI: 10.1111/brv.12345 -
Current Opinion in Endocrinology,... Aug 2021This article reviews the current state of research in type 1 diabetes and bone, focusing on human bone turnover markers and histomorphometry. (Review)
Review
PURPOSE OF REVIEW
This article reviews the current state of research in type 1 diabetes and bone, focusing on human bone turnover markers and histomorphometry.
RECENT FINDINGS
Bone turnover markers have been used for decades to document static bone turnover status in a variety of diseases but especially in diabetes. Two new studies focus on dynamic testing conditions to examine the acute effects of insulin and exercise on bone turnover. Publications of human bone histomorphometry in type 1 diabetes are few but there are several new studies currently underway.
SUMMARY
Here, we review the most recent literature on human bone turnover markers and histomorphometry. Low bone turnover is thought to be a major underlying factor in bone fragility in T1DM. Further studies in human transilial bone biopsies will be helpful in determining the mechanisms.
Topics: Biomarkers; Biopsy; Bone Density; Bone Remodeling; Bone and Bones; Diabetes Mellitus, Type 1; Exercise; Forecasting; Humans; Hypoglycemic Agents; Ilium; Insulin
PubMed: 34183539
DOI: 10.1097/MED.0000000000000644 -
Advanced Drug Delivery Reviews Sep 2012Demineralized bone matrix (DBM) is an osteoconductive and osteoinductive commercial biomaterial and approved medical device used in bone defects with a long track record... (Review)
Review
Demineralized bone matrix (DBM) is an osteoconductive and osteoinductive commercial biomaterial and approved medical device used in bone defects with a long track record of clinical use in diverse forms. True to its name and as an acid-extracted organic matrix from human bone sources, DBM retains much of the proteinaceous components native to bone, with small amounts of calcium-based solids, inorganic phosphates and some trace cell debris. Many of DBM's proteinaceous components (e.g., growth factors) are known to be potent osteogenic agents. Commercially sourced as putty, paste, sheets and flexible pieces, DBM provides a degradable matrix facilitating endogenous release of these compounds to the bone wound sites where it is surgically placed to fill bone defects, inducing new bone formation and accelerating healing. Given DBM's long clinical track record and commercial accessibility in standard forms and sources, opportunities to further develop and validate DBM as a versatile bone biomaterial in orthopedic repair and regenerative medicine contexts are attractive.
Topics: Animals; Bone Demineralization Technique; Bone Matrix; Bone Regeneration; Bone Substitutes; Bone Transplantation; Bone and Bones; Humans; Osteogenesis
PubMed: 22728914
DOI: 10.1016/j.addr.2012.06.008 -
Singapore Medical Journal Sep 2017Benign periarticular, bone and joint lipomatous lesions are rare entities that are increasingly being identified using current imaging techniques. This pictorial review... (Review)
Review
Benign periarticular, bone and joint lipomatous lesions are rare entities that are increasingly being identified using current imaging techniques. This pictorial review illustrates the wide range of imaging presentations of these lesions at various sites and their pathognomonic features. The main lesions reviewed include intraosseous lipoma, liposclerosing myxofibrous tumour, lipoma arborescens and intra-articular lipoma.
Topics: Adult; Bone Neoplasms; Bone and Bones; Female; Humans; Lipoma; Magnetic Resonance Imaging; Male; Middle Aged; Sacrum; Tibia
PubMed: 28948289
DOI: 10.11622/smedj.2017087 -
The Journal of Clinical Investigation May 2006Skin and bone - what comes to mind at hearing this phrase? While certainly a metaphor for disease, it also defines two very different tissues, one a flexible and... (Review)
Review
Skin and bone - what comes to mind at hearing this phrase? While certainly a metaphor for disease, it also defines two very different tissues, one a flexible and contiguous outer covering, the other a morphologically diverse hard tissue distributed at over 200 sites in the body. As the accompanying series of Reviews highlights, these tissues are indeed diverse, but there are also surprising similarities. Skin is the interface between the internal organs and the environment, and as such plays a crucial role in the body's defense mechanism. The skin and its many appendages are responsible for functions as diverse as epidermal barrier and defense, immune surveillance, UV protection, thermoregulation, sweating, lubrication, pigmentation, the sensations of pain and touch, and, importantly, the protection of various stem cell niches in the skin. Bone serves a number of purposes: it provides protection for vital organs, a lever for locomotion, a reservoir for calcium, and the site of adult hematopoiesis. The tissue is composed of osteoblasts, osteoclasts, and their individual precursors plus a complex mixture of mesenchymal, myeloid, and lymphoid cells in the marrow space. Finally, the endothelial microenvironment provides nutrition and is a conduit for the influx and emigration of cells that impact bone biology in several important ways. This Review series guides the reader through these various facets of 2 diverse, yet interdependent, tissues.
Topics: Animals; Bone and Bones; Humans; Models, Anatomic; Models, Biological; Skin; Skin Physiological Phenomena
PubMed: 16670754
DOI: 10.1172/JCI28605 -
TheScientificWorldJournal Mar 2002The skeleton is a complicated vertebrate structure, comprised of bone cells that form, modulate, and resorb the extracellular structure of bone. It is the extracellular...
The skeleton is a complicated vertebrate structure, comprised of bone cells that form, modulate, and resorb the extracellular structure of bone. It is the extracellular structure, made up of the bone mineral (largely calcium phosphate) and the bone matrix, which constitutes the visible skeleton and the mechanical support for the vertebrate body. The matrix is the protein structure on which the bone mineral is laid down, many components of which have been identified in recent years.
Topics: Bone and Bones; Editorial Policies; Female; Humans; Internet; Male; Periodicals as Topic
PubMed: 12806003
DOI: 10.1100/tsw.2002.213 -
Birth Defects Research. Part C, Embryo... Mar 2014The attachment between tendon and bone occurs across a complex transitional tissue that minimizes stress concentrations and allows for load transfer between muscles and... (Review)
Review
The attachment between tendon and bone occurs across a complex transitional tissue that minimizes stress concentrations and allows for load transfer between muscles and skeleton. This unique tissue cannot be reconstructed following injury, leading to high incidence of recurrent failure and stressing the need for new clinical approaches. This review describes the current understanding of the development and function of the attachment site between tendon and bone. The embryonic attachment unit, namely, the tip of the tendon and the bone eminence into which it is inserted, was recently shown to develop modularly from a unique population of Sox9- and Scx-positive cells, which are distinct from tendon fibroblasts and chondrocytes. The fate and differentiation of these cells is regulated by transforming growth factor beta and bone morphogenetic protein signaling, respectively. Muscle loads are then necessary for the tissue to mature and mineralize. Mineralization of the attachment unit, which occurs postnatally at most sites, is largely controlled by an Indian hedgehog/parathyroid hormone-related protein feedback loop. A number of fundamental questions regarding the development of this remarkable attachment system require further study. These relate to the signaling mechanism that facilitates the formation of an interface with a gradient of cellular and extracellular phenotypes, as well as to the interactions between tendon and bone at the point of attachment.
Topics: Animals; Bone and Bones; Humans; Musculoskeletal Physiological Phenomena; Tendons
PubMed: 24677726
DOI: 10.1002/bdrc.21056 -
Archives of Biochemistry and Biophysics Nov 2010The female reproductive system plays a major role in regulating the acquisition and loss of bone by the skeleton from menarche through senescence. Onset of gonadal sex... (Review)
Review
The female reproductive system plays a major role in regulating the acquisition and loss of bone by the skeleton from menarche through senescence. Onset of gonadal sex steroid secretion at puberty is the major factor responsible for skeletal longitudinal and radial growth, as well as significant gain in bone density, until peak bone density is achieved in third decade of life. Gonadal sex steroids then help maintain peak bone density until menopause, including during the transient changes in skeletal mineral content associated with pregnancy and lactation. At menopause, decreased gonadal sex steroid production normally leads to rapid bone loss. The most rapid bone loss associated with decreased estrogen levels occurs in the first 8-10 years after menopause, with slower age-related bone loss occurring during later life. Age-related bone loss in women after the early menopausal phase of bone loss is caused by ongoing gonadal sex steroid deficiency, vitamin D deficiency, and secondary hyperparathyroidism. Other factors also contribute to age-related bone loss, including intrinsic defects in osteoblast function, impairment of the GH/IGF axis, reduced peak bone mass, age-associated sarcopenia, and various sporadic secondary causes. Further understanding of the relative contributions of the female reproductive system and each of the other factors to development and maintenance of the female skeleton, bone loss, and fracture risk will lead to improved approaches for prevention and treatment of osteoporosis.
Topics: Animals; Bone Diseases; Bone and Bones; Female; Humans; Lactation; Menarche; Pregnancy; Reproduction
PubMed: 20637179
DOI: 10.1016/j.abb.2010.07.006