Dataset Information

Astrocyte extracellular matrix modulates neuronal dendritic development.

ABSTRACT: Major developmental events occurring in the hippocampus during the third trimester of human gestation and neonatally in altricial rodents include rapid and synchronized dendritic arborization and astrocyte proliferation and maturation. We tested the hypothesis that signals sent by developing astrocytes to developing neurons modulate dendritic development in vivo. We altered neuronal development by neonatal (third trimester-equivalent) ethanol exposure in mice; this treatment increased dendritic arborization in hippocampal pyramidal neurons. We next assessed concurrent changes in the mouse astrocyte translatome by translating ribosomal affinity purification (TRAP)-seq. We followed up on ethanol-inhibition of astrocyte Chpf2 and Chsy1 gene translation because these genes encode for biosynthetic enzymes of chondroitin sulfate glycosaminoglycan (CS-GAG) chains (extracellular matrix components that inhibit neuronal development and plasticity) and have not been explored before for their roles in dendritic arborization. We report that Chpf2 and Chsy1 are enriched in astrocytes and their translation is inhibited by ethanol, which also reduces the levels of CS-GAGs measured by Liquid Chromatography/Mass Spectrometry. Finally, astrocyte-conditioned medium derived from Chfp2-silenced astrocytes increased neurite branching of hippocampal neurons in vitro. These results demonstrate that CS-GAG biosynthetic enzymes in astrocytes regulates dendritic arborization in developing neurons.

SUBMITTER: Hashimoto JG

PROVIDER: S-EPMC11361265 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Astrocyte extracellular matrix modulates neuronal dendritic development.

Hashimoto Joel G JG Margolies Nicholas N Zhang Xiaolu X Karpf Joshua J Song Yuefan Y Davis Brett A BA Zhang Fuming F Linhardt Robert J RJ Carbone Lucia L Guizzetti Marina M

bioRxiv : the preprint server for biology 20240822

Major developmental events occurring in the hippocampus during the third trimester of human gestation and neonatally in altricial rodents include rapid and synchronized dendritic arborization and astrocyte proliferation and maturation. We tested the hypothesis that signals sent by developing astrocytes to developing neurons modulate dendritic development <i>in vivo</i>. We altered neuronal development by neonatal (third trimester-equivalent) ethanol exposure in mice; this treatment increased den ...[more]

PMID: 39211148

Similar Datasets

Project description:The extracellular matrix plays a critical role in modulating cell behaviour in the developing and adult central nervous system influencing neural cell morphology, function and growth. Neurons and astrocytes, play vital roles in neural signalling and support respectively and respond to cues from the surrounding matrix environment. However, a better understanding of the impact of specific individual extracellular matrix proteins on both neurons and astrocytes is critical for advancing the development of matrix-based scaffolds for neural repair applications. This study aimed to provide an in-depth analysis of how different commonly used extracellular matrix proteins- laminin-1, Fn, collagen IV, and collagen I-affect the morphology and growth of trophic induced pluripotent stem cell (iPSC)-derived astrocyte progenitors and mouse motor neuron-like cells. Following a 7-day culture period, morphological assessments revealed that laminin-1, fibronectin, and collagen-IV, but not collagen I, promoted increased process extension and a stellate morphology in astrocytes, with collagen-IV yielding the greatest increases. Subsequent analysis of neurons grown on the different extracellular matrix proteins revealed a similar pattern with laminin-1, fibronectin, and collagen-IV supporting robust neurite outgrowth. fibronectin promoted the greatest increase in neurite extension, while collagen-I did not enhance neurite growth compared to poly-L-lysine controls. Super-resolution microscopy highlighted extracellular matrix-specific nanoscale changes in cytoskeletal organization, with distinct patterns of actin filament distribution where the three basement membrane-associated proteins (laminin-1, fibronectin, and collagen-IV) promoted the extension of fine cellular processes. Overall, this study demonstrates the potent effect of laminin-1, fibronectin and collagen-IV to promote both iPSC-derived astrocyte progenitor and neuronal growth, yielding detailed insights into the effect of extracellular matrix proteins on neural cell morphology at both the whole cell and nanoscale levels. The ability of laminin-1, collagen-IV and fibronectin to elicit strong growth-promoting effects highlight their suitability as optimal extracellular matrix proteins to incorporate into neurotrophic biomaterial scaffolds for the delivery of cell cargoes for neural repair.

Project description:Fragile X syndrome (FXS) is a form of inherited mental retardation in humans that results from expansion of a CGG repeat in the Fmr1 gene. Recent studies suggest a role of astrocytes in neuronal development. However, the mechanisms involved in the regulation process of astrocytes from FXS remain unclear. In this study, we found that astrocytes derived from a Fragile X model, the Fmr1 knockout (KO) mouse which lacks FMRP expression, inhibited the proper elaboration of dendritic processes of neurons in vitro. Furthermore, astrocytic conditioned medium (ACM) from KO astrocytes inhibited proper dendritic growth of both wild-type (WT) and KO neurons. Inducing expression of FMRP by transfection of FMRP vectors in KO astrocytes restored dendritic morphology and levels of synaptic proteins. Further experiments revealed elevated levels of the neurotrophin-3 (NT-3) in KO ACM and the prefrontal cortex of Fmr1 KO mice. However, the levels of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), and ciliary neurotrophic factor (CNTF) were normal. FMRP has multiple RNA-binding motifs and is involved in translational regulation. RNA-binding protein immunoprecipitation (RIP) showed the NT-3 mRNA interacted with FMRP in WT astrocytes. Addition of high concentrations of exogenous NT-3 to culture medium reduced the dendrites of neurons and synaptic protein levels, whereas these measures were ameliorated by neutralizing antibody to NT-3 or knockdown of NT-3 expression in KO astrocytes through short hairpin RNAs (shRNAs). Prefrontal cortex microinjection of WT astrocytes or NT-3 shRNA infected KO astrocytes rescued the deficit of trace fear memory in KO mice, concomitantly decreased the NT-3 levels in the prefrontal cortex. This study indicates that excessive NT-3 from astrocytes contributes to the abnormal neuronal dendritic development and that astrocytes could be a potential therapeutic target for FXS.

Project description:Extracellular matrix (ECM) is comprised of different types of proteins, which change in composition and ratios during morphogenesis and disease progression. ECM proteins provide cell adhesion and impart mechanical cues to the cells. Increasing substrate stiffness has been shown to induce Yes-associated protein (YAP) translocation from the cytoplasm to the nucleus, yet these mechanistic studies used fibronectin only as the biochemical cue. How varying the types of ECM modulates mechanotransduction of stem cells remains largely unknown. Using polyacrylamide hydrogels with tunable stiffness as substrates, here we conjugated four major ECM proteins commonly used for cell adhesion: fibronectin, collagen I, collagen IV and laminin, and assessed the effects of varying ECM type and density on YAP translocation in human mesenchymal stem cells (hMSCs). For all four ECM types, increasing ECM ligand density alone can induce YAP nuclear translocation without changing substrate stiffness. The ligand threshold for such biochemical ligand-induced YAP translocation differs across ECM types. While stiffness-dependent YAP translocation can be induced by all four ECM types, each ECM requires a different optimized ligand density for this to occur. Using antibody blocking, we further identified integrin subunits specifically involved in mechanotransduction of different ECM types. Finally, we demonstrated that altering ECM type further modulates hMSC osteogenesis without changing substrate stiffness. These findings highlight the important role of ECM type in modulating mechanotransduction and differentiation of stem cells, and call for future mechanistic studies to further elucidate the role of changes in ECM compositions in mediating mechanotransduction during morphogenesis and disease progression. STATEMENT OF SIGNIFICANCE: Our study addresses a critical gap of knowledge in mechanobiology. Increasing substrate stiffness has been shown to induce nuclear YAP translocation, yet only on fibronectin-coated substrates. However, extracellular matrix (ECM) is comprised of different protein types. How varying the type of ECM modulates stem cell mechanotransduction remains largely unknown. We here reveal that the choice of ECM type can directly modulate stem cell mechanotransduction, filling this critical gap. This work has broad impacts in mechanobiology and biomaterials, as it provides the first evidence that varying ECM type can impact YAP translocation independent of substrate stiffness, opening doors for a more rational biomaterials design tuning ECM properties to control cell fate for promoting normal development and for preventing disease progression.

Dataset Information

Astrocyte extracellular matrix modulates neuronal dendritic development.

Publications

Astrocyte extracellular matrix modulates neuronal dendritic development.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets