Aggrecan Is Expressed By Embryonic Brain Glia And Regulates Astrocyte Development Pdf
File Name: aggrecan is expressed by embryonic brain glia and regulates astrocyte development .zip
- Sugar glues for broken neurons
- Astrocytes as a source for extracellular matrix molecules and cytokines
- Extracellular matrix of the central nervous system: from neglect to challenge
Glial cells in the central nervous system CNS contribute to formation of the extracellular matrix, which provides adhesive sites, signaling molecules, and a diffusion barrier to enhance efficient neurotransmission and axon potential propagation. In the normal adult CNS, the extracellular matrix ECM is relatively stable except in selected regions characterized by dynamic remodeling. However, after trauma such as a spinal cord injury or cortical contusion, the lesion epicenter becomes a focus of acute neuroinflammation.
Sugar glues for broken neurons
Biochem J 15 July ; 14 : — The a disintegrin-like and metalloproteinase with thrombospondin type-1 motifs ADAMTS family of metzincins are complex secreted proteins that have diverse functions during development. The hyalectanases ADAMTS1, 4, 5, 8, 9, 15 and 20 are a subset of this family that have enzymatic activity against hyalectan proteoglycans, the processing of which has important implications during development. This review gives an overview of how the family and their substrates evolved from non-vertebrates to mammals, the expression of the hyalectanases and substrates in different species and their functions during development, and how these functions are conserved across species. Sign In or Create an Account.
Proteoglycans PGs regulate diverse functions in the central nervous system CNS by interacting with a number of growth factors, matrix proteins, and cell surface molecules. The functionality of these PGs is to a large extent dictated by the fine sulfation patterns present on their glycosaminoglycan GAG chains. In the past 15 years, there has been a significant expansion in our knowledge on the role of HS and CS chains in various neurological processes, such as neuronal growth, regeneration, plasticity, and pathfinding. However, defining the relation between distinct sulfation patterns of the GAGs and their functionality has thus far been difficult. With the emergence of novel tools for the synthesis of defined GAG structures, and techniques for their characterization, we are now in a better position to explore the structure-function relation of GAGs in the context of their sulfation patterns. In this review, we discuss the importance of GAGs on CNS development, injury, and disorders with an emphasis on their sulfation patterns.
Proteoglycans, as part of the extracellular or cell-surface milieu of most tissues and organ systems, play important roles in morphogenesis by modulating cell-matrix or cell-cell interactions, cell adhesiveness, or by binding and presenting growth and differentiation factors. Chondroitin sulfate proteoglycans which constitute the major population of proteoglycans in the central nervous system may influence formation of neuronal nuclei, establishment of boundaries for axonal growth and act as modulators of neuronal outgrowth during brain development, as well as during regeneration after injury. There is a paucity of information on the role of chondroitin sulfate proteoglycans in central nervous system organogenesis. In the chick embryo, aggrecan has a regionally specific and developmentally regulated expression profile during brain development. By Northern and Western blot analysis, aggrecan expression is first detected in chick brain on embryonic day 7 E7 , increases from E7 to E13, declines markedly after E16, and is not evident in hatchling brains. The time course and pattern of aggrecan expression observed in ventricular zone cells suggested that it might play a role in gliogenesis.
Astrocytes as a source for extracellular matrix molecules and cytokines
Synapses are specialized structures that mediate rapid and efficient signal transmission between neurons and are surrounded by glial cells. Astrocytes develop an intimate association with synapses in the central nervous system CNS and contribute to the regulation of ion and neurotransmitter concentrations. Together with neurons, they shape intercellular space to provide a stable milieu for neuronal activity. Extracellular matrix ECM components are synthesized by both neurons and astrocytes and play an important role in the formation, maintenance, and function of synapses in the CNS. The components of the ECM have been detected near glial processes, which abut onto the CNS synaptic unit, where they are part of the specialized macromolecular assemblies, termed perineuronal nets PNNs.
Determination of the molecules that regulate astrocyte development has been hindered by the paucity of markers that identify astrocytic.
Extracellular matrix of the central nervous system: from neglect to challenge
Research of the past 25 years has shown that astrocytes do more than participating and building up the blood-brain barrier and detoxify the active synapse by reuptake of neurotransmitters and ions. Indeed, astrocytes express neurotransmitter receptors and, as a consequence, respond to stimuli. Within the tripartite synapse, the astrocytes owe more and more importance. Besides the functional aspects the differentiation of astrocytes has gained a more intensive focus. Specific differentiation of neural stem cells toward the astroglial lineage is performed as a multi-step process.
Neurons and glial cells in the central nervous system are tightly associated to each other, maintaining physiological homeostasis of the human body. In addition to the cell-cell interaction, the CNS is also composed of elaborated and complicated extracellular matrixes ECMs. Neural ECMs are radically different from those of other tissues.
Metrics details. Traumatic brain injury TBI is one of the leading causes of fatality and disability worldwide. Despite its high prevalence, effective treatment strategies for TBI are limited.
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