Similar Datasets
Project description:Heparan sulfate (HS) regulation of FGFR function, which is essential for salivary gland (SG) development, is determined by the immense structural diversity of sulfated HS domains. 3-O-sulfotransferases generate highly 3-O-sulfated HS domains (3-O-HS), and Hs3st3a1 and Hs3st3b1 are enriched in myoepithelial cells (MECs) that produce basement membrane (BM) and are a growth factor signaling hub. Hs3st3a1;Hs3st3b1 double-knockout (DKO) mice generated to investigate 3-O-HS regulation of MEC function and growth factor signaling show loss of specific highly 3-O-HS and increased FGF/FGFR complex binding to HS. During development, this increases FGFR-, BM- and MEC-related gene expression, while in adult, it reduces MECs, increases BM and disrupts acinar polarity, resulting in salivary hypofunction. Defined 3-O-HS added to FGFR pulldown assays and primary organ cultures modulates FGFR signaling to regulate MEC BM synthesis, which is critical for secretory unit homeostasis and acinar function. Understanding how sulfated HS regulates development will inform the use of HS mimetics in organ regeneration.
| S-EPMC11365954 | biostudies-literature
Project description:FGF signaling is essential for salivary gland (SG) development and heparan sulfate (HS) regulation of FGFR function is determined by immense structural diversity of sulfated HS domains. The basement membrane (BM), containing HS proteoglycans, collagens and laminins, separates epithelia from stroma and controls growth factor-matrix cross-talk. 3-O-sulfotransferases generate highly 3-O-sulfated HS domains (3-O-HS) and Hs3st3a1 and Hs3st3b1 are enriched in myoepithelial cells (MECs), which produce BM and are a growth factor signaling hub. To investigate 3-O-HS regulation of MEC function and growth factor signaling, we generated Hs3st3a1;Hs3st3b1 double knockout (DKO) mice. The DKO HS loses specific highly 3-O-sulfated tetrasaccharides, which increases FGF/FGFR-complex binding to HS. During development this leads to increased FGFR-, BM- and MEC-related gene expression. However, in adult DKO SGs the secretory units containing acinar and MECs, have reduced MECs, increased BM and disrupted acinar polarity, resulting in salivary hypofunction. We used defined 3-O-sulfated-HS in FGFR pulldown assays and primary organ cultures to investigate 3-O-HS-dependent mechanisms regulating MEC development. We find that 3-O-HS modulates FGFR signaling to regulate MEC BM synthesis which is critical for secretory unit homeostasis and acinar function. Understanding how sulfated HS regulates development will inform the use of HS mimetics in organ regeneration.
2024-08-02 | GSE235185 | GEO
Project description:FGF signaling is essential for salivary gland (SG) development and heparan sulfate (HS) regulation of FGFR function is determined by immense structural diversity of sulfated HS domains. The basement membrane (BM), containing HS proteoglycans, collagens and laminins, separates epithelia from stroma and controls growth factor-matrix cross-talk. 3-O-sulfotransferases generate highly 3-O-sulfated HS domains (3-O-HS) and Hs3st3a1 and Hs3st3b1 are enriched in myoepithelial cells (MECs), which produce BM and are a growth factor signaling hub. To investigate 3-O-HS regulation of MEC function and growth factor signaling, we generated Hs3st3a1;Hs3st3b1 double knockout (DKO) mice. The DKO HS loses specific highly 3-O-sulfated tetrasaccharides, which increases FGF/FGFR-complex binding to HS. During development this leads to increased FGFR-, BM- and MEC-related gene expression. However, in adult DKO SGs the secretory units containing acinar and MECs, have reduced MECs, increased BM and disrupted acinar polarity, resulting in salivary hypofunction. We used defined 3-O-sulfated-HS in FGFR pulldown assays and primary organ cultures to investigate 3-O-HS-dependent mechanisms regulating MEC development. We find that 3-O-HS modulates FGFR signaling to regulate MEC BM synthesis which is critical for secretory unit homeostasis and acinar function. Understanding how sulfated HS regulates development will inform the use of HS mimetics in organ regeneration.
2024-08-02 | GSE235184 | GEO
Project description:Heparan sulfate (HS) serves as a cell-surface co-receptor for growth factors, morphogens, and chemokines. These HS and protein binding events depend on the fine structure and distribution of domains along an HS chain. A given domain can vary in terms of uronic acid epimer, N- and O-sulfate, and N-acetate content. The most highly sulfated regions of HS chains, N-sulfated (NS) domains, play prominent roles in HS and protein binding. We have analyzed HS oligosaccharides from various mammalian sources and provide evidence that NS domains residing at the nonreducing end (NRE) are, on average, longer than those residing in the internal regions of the chain. Additionally, they are more highly sulfated than their internal counterparts. These features are independent of the sulfation pattern of the bulk HS chains. From disaccharide analysis, it is clear that NS domains do not always occupy HS NREs. However, when they do, they tend to terminate in a subset of N-sulfated disaccharides. Our observations are consistent with a significant role of NRE NS domains in HS-growth factor interactions.
| S-EPMC2881759 | biostudies-literature
Project description:Lipoprotein lipase (Lpl) acts on triglyceride-rich lipoproteins in the peripheral circulation, liberating free fatty acids for energy metabolism or storage. This essential enzyme is synthesized in parenchymal cells of adipose tissue, heart, and skeletal muscle and migrates to the luminal side of the vascular endothelium where it acts upon circulating lipoproteins. Prior studies suggested that Lpl is immobilized by way of heparan sulfate proteoglycans on the endothelium, but genetically altering endothelial cell heparan sulfate had no effect on Lpl localization or lipolysis. The objective of this study was to determine if extracellular matrix proteoglycans affect Lpl distribution and triglyceride metabolism.We examined mutant mice defective in collagen XVIII (Col18), a heparan sulfate proteoglycan present in vascular basement membranes. Loss of Col18 reduces plasma levels of Lpl enzyme and activity, which results in mild fasting hypertriglyceridemia and diet-induced hyperchylomicronemia. Humans with Knobloch Syndrome caused by a null mutation in the vascular form of Col18 also present lower than normal plasma Lpl mass and activity and exhibit fasting hypertriglyceridemia.This is the first report demonstrating that Lpl presentation on the lumenal side of the endothelium depends on a basement membrane proteoglycan and demonstrates a previously unrecognized phenotype in patients lacking Col18.
| S-EPMC2978080 | biostudies-literature
Project description:Heparan sulfate-modified proteoglycans (HSPGs) are important regulators of signaling and molecular recognition at the cell surface and in the extracellular space. Disruption of HSPG core proteins, HS-synthesis, or HS-degradation can have profound effects on growth, patterning, and cell survival. The Drosophila neuromuscular junction provides a tractable model for understanding the activities of HSPGs at a synapse that displays developmental and activity-dependent plasticity. Muscle cell-specific knockdown of HS biosynthesis disrupted the organization of a specialized postsynaptic membrane, the subsynaptic reticulum (SSR), and affected the number and morphology of mitochondria. We provide evidence that these changes result from a dysregulation of macroautophagy (hereafter referred to as autophagy). Cellular and molecular markers of autophagy are all consistent with an increase in the levels of autophagy in the absence of normal HS-chain biosynthesis and modification. HS production is also required for normal levels of autophagy in the fat body, the central energy storage and nutritional sensing organ in Drosophila. Genetic mosaic analysis indicates that HS-dependent regulation of autophagy occurs non-cell autonomously, consistent with HSPGs influencing this cellular process via signaling in the extracellular space. These findings demonstrate that HS biosynthesis has important regulatory effects on autophagy and that autophagy is critical for normal assembly of postsynaptic membrane specializations.
| S-EPMC5584867 | biostudies-other
Project description:Carbohydrate chip technology has a great potential for the high-throughput evaluation of carbohydrate-protein interactions. Herein, we report syntheses of novel sulfated oligosaccharides possessing heparin and heparan sulfate partial disaccharide structures, their immobilization on gold-coated chips to prepare array-type Sugar Chips, and evaluation of binding potencies of proteins by surface plasmon resonance (SPR) imaging technology. Sulfated oligosaccharides were efficiently synthesized from glucosamine and uronic acid moieties. Synthesized sulfated oligosaccharides were then easily immobilized on gold-coated chips using previously reported methods. The effectiveness of this analytical method was confirmed in binding experiments between the chips and heparin binding proteins, fibronectin and recombinant human von Willebrand factor A1 domain (rh-vWf-A1), where specific partial structures of heparin or heparan sulfate responsible for binding were identified.
| S-EPMC2423310 | biostudies-literature
Project description:Heparan sulfate (HS) molecules are ubiquitous in animal tissues where they function as ligands that are dramatically involved in the regulation of the proteins they bind. Of these, chemokines are a family of small proteins with many biological functions. Their well-conserved monomeric structure can associate in various oligomeric forms especially in the presence of HS. Application of protein surface analysis and energy calculations to all known chemokine structures leads to the proposal that four different binding modes are created by the folding and oligomerization of these proteins. So, based on the present state of our knowledge, four different clusters of amino acids should be involved in the recognition process. Our results help to rationalize how unique sequences of HS specifically bind any given chemokine. The conclusions open the route for a rational design of compounds of therapeutical interest that could influence chemokine activity.
| S-EPMC122172 | biostudies-literature
Project description:Human fibroblast growth factor-2 (FGF2) regulates cellular processes including proliferation, adhesion, motility, and angiogenesis. FGF2 exerts its biological function by binding and dimerizing its receptor (FGFR), which activates signal transduction cascades. Effective binding of FGF2 to its receptor requires the presence of heparan sulfate (HS), a linear polysaccharide with N-sulfated domains (NS) localized at the cell surface and extracellular matrix. HS acts as a platform facilitating the formation of a functional FGF-FGFR-HS ternary complex. Crystal structures of the signaling ternary complex revealed two conflicting architectures. In the asymmetrical model, two FGFs and two FGFRs bind a single HS chain. In contrast, the symmetrical model postulates that one FGF and one FGFR bind to the free end of the HS chain and dimerization require these ends to join, bringing the two half-complexes together. In this study, we screened a hexasaccharide HS library for compositions that are able to bind FGF2. The library was composed primarily of NS domains internal to the HS chain with minor presence of non-reducing end (NRE) NS. The binders were categorized into low versus high affinity binders. The low affinity fraction contained primarily hexasaccharides with low degree of sulfation that were internal to the HS chains. In contrast, the high affinity bound fraction was enriched in NRE oligosaccharides that were considerably more sulfated and had the ability to promote FGFR-mediated cell proliferation. The results suggest a role of the NRE of HS in FGF2 signaling and favor the formation of the symmetrical architecture on short NS domains.
| S-EPMC3103309 | biostudies-literature
Project description:Hair follicle (HF) morphogenesis and cycling are a result of intricate autonomous epithelial-mesenchymal interactions. Once the first HF cycle is complete it repeatedly undergoes cyclic transformations. Heparan sulfate (HS) proteoglycans are found on the cell surface and in the extracellular matrix where they influence a variety of biological processes by interacting with physiologically important proteins, such as growth factors. Inhibition of heparanase (an HS endoglycosidase) in in vitro cultured HFs has been shown to induce a catagen-like process. Therefore, this study aimed to elucidate the precise role of HS in HF morphogenesis and cycling. An inducible tetratransgenic mouse model was generated to excise exostosin glycosyltransferase 1 (Ext1) in keratin 14-positive cells from P21. Interestingly, EXT1(StEpi?/StEpi?) mice presented solely anagen HFs. Moreover, waxing the fur to synchronize the HFs revealed accelerated hair regrowth in the EXT1(StEpi?/StEpi?) mice and hindered cycling into catagen. The ablation of HS in the interfollicular epidermal cells of mature skin led to the spontaneous formation of new HFs and an increase in Sonic Hedgehog expression resembling wild-type mice at P0, thereby indicating that the HS/Sonic Hedgehog signaling pathway regulates HF formation during embryogenesis and prevents HF formation in mature skin. Finally, the knock-out of HS also led to the morphogenesis and hyperplasia of sebaceous glands and sweat glands in mature mice, leading to exacerbated sebum production and accumulation on the skin surface. Therefore, our findings clearly show that an intricate control of HS levels is required for HF, sebaceous gland, and sweat gland morphogenesis and HF cycling.
| S-EPMC4155684 | biostudies-literature