S100B and S100A1 proteins in bovine retina: their calcium-dependent stimulation of a membrane-bound guanylate cyclase activity as investigated by ultracytochemistry

Rambotti, Maria Grazia; Giambanco, Ileana; Spreca, A; Donato, Rosario

doi:10.1016/s0306-4522(99)00074-3

Cited by 51 publications

(34 citation statements)

References 45 publications

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“…S100B is a member of a family of Ca 2+ -binding proteins of the EF-hand type [36] and is produced by various cell types including astrocytes, maturing oligodendrocytes, neural progenitor cells, Langerhans cells, dendritic cells and myoblasts [37]. S100B is specifically found in several cell types in bovine retina, including photoreceptors and Müller glial processes, in which S100B-stimulated membrane-bound guanylate cyclase activity can be induced [38]. GFAP and S100B content has been reported to be reduced in glia cultured in high glucose medium [39].…”

Section: Discussionmentioning

confidence: 99%

Hyperglycaemia-induced pro-inflammatory responses by retinal Müller glia are regulated by the receptor for advanced glycation end-products (RAGE)

et al. 2010

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Aims/hypothesis Up-regulation of the receptor for AGEs (RAGE) and its ligands in diabetes has been observed in various tissues. Here, we sought to determine levels of RAGE and one of its most important ligands, S100B, in diabetic retina, and to investigate the regulatory role of S100B and RAGE in Müller glia. Methods Streptozotocin-diabetes was induced in SpragueDawley rats. RAGE, S100B and glial fibrillary acidic protein (GFAP) were detected in retinal cryosections. In parallel, the human retinal Müller cell line, MIO-M1, was maintained in normal glucose (5.5 mmol/l) or high glucose (25 mmol/l). RAGE knockdown was achieved using small interfering RNA (siRNA), while soluble RAGE was used as a competitive inhibitor of RAGE ligand binding. RAGE, S100B and cytokines were detected using quantitative RT-PCR, western blotting, cytokine protein arrays or ELISA. Activation of mitogen-activated protein kinase (MAPK) by RAGE was determined by western blotting. Results Compared with non-diabetic controls, RAGE and S100B were significantly elevated in the diabetic retina with apparent localisation in the Müller glia, occurring concomitantly with upregulation of GFAP. Exposure of MIO-M1 cells to high glucose induced increased production of RAGE and S100B. RAGE signalling via MAPK pathway was linked to cytokine production. Blockade of RAGE prevented cytokine responses induced by high glucose and S100B in Müller glia. Conclusions/interpretation Hyperglycaemia in vivo and in vitro exposure to high glucose induce upregulation of RAGE and its ligands, leading to RAGE signalling, which links to pro-inflammatory responses by retinal Müller glia. These data shed light on the potential clinical application of RAGE blockade to inhibit the progression of diabetic retinopathy.

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Section: Discussionmentioning

confidence: 99%

Hyperglycaemia-induced pro-inflammatory responses by retinal Müller glia are regulated by the receptor for advanced glycation end-products (RAGE)

et al. 2010

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“…Does S100B or S100A1 have a role in type III IF dynamics in vivo? S100B, but not S100A1 was localized to GFAP, vimentin and desmin IFs in several cell lines as well as to GFAP IFs in Müller cells in bovine retina, and was observed to follow the destiny of these IFs after cell treatment with colchicine, taxol, cold, or inhibitors of phosphatases (all conditions that cause a dramatic rearrangement of IFs or, in the case of phosphatase inhibitors, IF disassembly and condensation of residual IFs in a paranuclear structure also containing MTs) (27,28,52). Also, at several cell sites MTs with their attached S100B appear surrounded and/or flanked by IFs with their attached S100B (32).…”

Section: Garbuglia Et Almentioning

confidence: 99%

“…The observation that S100B is also found associated with IFs in glial cells (26,27,52) prompted a study of possible regulatory effects of this protein as well as of S100A1 on glial and skeletal muscle IFs. The IF subunits in mature glial and skeletal muscle cells are glial fibrillary acidic protein (GFAP) and desmin, respectively, both of which belong to type III IFs (1)(2)(3)(4)(5).…”

Section: S100b and S100a1 Regulate The Dynamics Of Intermediate Filammentioning

confidence: 99%

The calcium-modulated proteins, S100A1 and S100B, as potential regulators of the dynamics of type III intermediate filaments

Garbuglia

Verzini

Sorci

et al. 1999

Braz J Med Biol Res

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The Ca 2+ -modulated, dimeric proteins of the EF-hand (helix-loophelix) type, S100A1 and S100B, that have been shown to inhibit microtubule (MT) protein assembly and to promote MT disassembly, interact with the type III intermediate filament (IF) subunits, desmin and glial fibrillary acidic protein (GFAP), with a stoichiometry of 2 mol of IF subunit/mol of S100A1 or S100B dimer and an affinity of 0.5-1.0 µM in the presence of a few micromolar concentrations of Ca 2+ . Binding of S100A1 and S100B results in inhibition of desmin and GFAP assemblies into IFs and stimulation of the disassembly of preformed desmin and GFAP IFs. S100A1 and S100B interact with a stretch of residues in the N-terminal (head) domain of desmin and GFAP, thereby blocking the head-to-tail process of IF elongation. The C-terminal extension of S100A1 (and, likely, S100B) represents a critical part of the site that recognizes desmin and GFAP. S100B is localized to IFs within cells, suggesting that it might have a role in remodeling IFs upon elevation of cytosolic Ca 2+ concentration by avoiding excess IF assembly and/or promoting IF disassembly in vivo. S100A1, that is not localized to IFs, might also play a role in the regulation of IF dynamics by binding to and sequestering unassembled IF subunits. Together, these observations suggest that S100A1 and S100B may be regarded as Ca 2+ -dependent regulators of the state of assembly of two important elements of the cytoskeleton, IFs and MTs, and, potentially, of MT-and IF-based activities.

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“…The cytosolic form is presumed to be secreted (or released during cell death) acting as a chemotaxic agent for epidermal growth and differentiation. In addition, S100B binds to and regulates the calcium-dependent activity of a membranebound guanylate cyclase protein in bovine retina [56,57]. Perhaps in a manner similar to that reported in the mammalian retina, the cytoplasmic portion of S100A1 in the apical region of the vestibular hair cells may be involved in modulating sensory transduction by binding to a plasma membrane-bound protein.…”

Section: Possible Functions Of S100a1 and S100b In Vestibular End Organsmentioning

confidence: 91%

Untitled

2017

MOJAP

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Using immunohistochemical techniques, the distribution of the "classic" S100 calcium binding proteins, α (A1) and β (B), was determined in the mammalian vestibular end organs. An affinity-purified polyclonal antibody which recognized both the A1 and B subunits and two monoclonal antibodies specific for either the A1 or the B subunit were used in this study. S100A1 was localized specifically to the basal region of the sensory epithelium (saccular macula, cristae ampullaris and utricular macula) when a cross-linking fixative (4% paraformaldehyde) was utilized. Using a fixation protocol including paraformaldehyde and a precipitating fixative revealed an additional localization of S100A1 to the apical region of the saccular macula, cristae ampullaris and utricular macula. This indicates the presence of two populations of S100A1 in these cells: a cytosolic (soluble) component; and a membrane-bound fraction. In contrast, S100B was localized to the layer of the vestibular nerve fibers. Immunoreactivity for S100B was not observed in the sensory epithelium of the saccular or utricular macula or in the cristae ampullaris. The preferential distribution of S100B to the nerve fibers and S100A1 to cells of the sensory epithelium, in two forms (cytosolic and membranebound), may be important in the functional roles of S100 proteins in the vestibular sensory end organs.

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S100B and S100A1 proteins in bovine retina: their calcium-dependent stimulation of a membrane-bound guanylate cyclase activity as investigated by ultracytochemistry

Cited by 51 publications

References 45 publications

Hyperglycaemia-induced pro-inflammatory responses by retinal Müller glia are regulated by the receptor for advanced glycation end-products (RAGE)

Hyperglycaemia-induced pro-inflammatory responses by retinal Müller glia are regulated by the receptor for advanced glycation end-products (RAGE)

The calcium-modulated proteins, S100A1 and S100B, as potential regulators of the dynamics of type III intermediate filaments

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