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Johannes Roth - One of the best experts on this subject based on the ideXlab platform.

  • 01 03 ttp s100a9 deficient mice promote a tnf dependent psoriatic arthritis phenotype triggered by the bacterial environment
    Annals of the Rheumatic Diseases, 2017
    Co-Authors: Athanasios Stratis, Johannes Roth, Thomas Vogl, Mareike Frohling, Karin Loser, Peter Paruzel, Perry J Blackshear, Debbie Stumpo, Thomas Pap
    Abstract:

    Background Psoriatic-Arthritis (PsA) is a type of inflammatory chronic arthritis with a seronegative spondyloarthropathy and associated psoriasis. The Danger-Associated Molecular Pattern molecules (DAMPs) S100A8 and S100A9 are both antimicrobial proteins with chemotactic activity and are the most abundant DAMPs expressed during many inflammatory disorders. The expression of the S100A8/S100A9-complex is highly elevated in psoriasis and psoriatic arthritis. However, the mechanisms that regulate S100A8/S100A9-complex-activities are poorly understood, which has led us to examine the role of S100A8 and S100A9 under chronic inflammatory conditions. Material and methods We crossed S100A9-deficient mice with TTP (tristetraprolin)-deficient mice into a systemic inflammatory model featuring high levels of TNF with an arthritic joint destruction phenotype. Disease progression in TTP-/- x S100A9-/- mice was analysed by immunostaining, immunohistochemistry and the adapted PASI-score. To neutralise TNF in TTP-/- x S100A9-/- mice we used an aTNF-inhibiting monoclonal antibody already in clinical use for therapy of arthritis and psoriasis. To measure altered protein levels we used Western blot analysis. Primary keratinocytes were isolated of the skin from newborn mice and infected with E.coli isolated from the faeces of mice. Results TTP/S100A9 deficiency led to highly elevated levels of the S100A9 complex partner S100A8 in the epidermis and to a severe psoriatic phenotype of TTP-/- x S100A9-/- mice. Furthermore the mice showed an accelerated course of arthritis compared to TTP-/- mice, including increased articular cartilage loss and bone destruction. Inhibition of TNF by application of anti-TNF clearly reduced the psoriatic phenotype of TTP-/- x S100A9-/- mice. Additionally, the reduction of the environmental bacterial levels led to a milder phenotype and decelerated pathogenesis. The in vitro infection of isolated keratinocytes with isolated E.coli resulted in a high expression of S100A8. Conclusions The data reveal that the S100A8/S100A9-complex acts not only as a systemic danger signal molecule, but is also TNF dependent and is essential for the regulation of inflammation. The loss of S100A9 led to a disregulated inflammatory response and this to a severe psoriasis with enhanced cartilage and bone destruction. Furthermore, an exogenic bacterial factor, such as E. coli, is also demonstrated to be important in the activation of the disease.

  • alarmins s100a8 s100a9 aggravate osteophyte formation in experimental osteoarthritis and predict osteophyte progression in early human symptomatic osteoarthritis
    Annals of the Rheumatic Diseases, 2016
    Co-Authors: R.f. Schelbergen, W. De Munter, M.h. Van Den Bosch, Annet W. Sloetjes, Johannes Roth, Thomas Vogl, W.b. Van Den Berg, Peter M Van Der Kraan, Floris P J G Lafeber, Arjen B. Blom
    Abstract:

    OBJECTIVE: Alarmins S100A8 and S100A9 are major products of activated macrophages regulating cartilage damage and synovial activation during murine and human osteoarthritis (OA). In the current study, we investigated whether S100A8 and S100A9 are involved in osteophyte formation during experimental OA and whether S100A8/A9 predicts osteophyte progression in early human OA. METHODS: OA was elicited in S100A9-/- mice in two experimental models that differ in degree of synovial activation. Osteophyte size, S100A8, S100A9 and VDIPEN neoepitope was measured histologically. Chondrogenesis was induced in murine mesenchymal stem cells in the presence of S100A8. Levels of S100A8/A9 were determined in plasma of early symptomatic OA participants of the Cohort Hip and Cohort Knee (CHECK) cohort study and osteophytes measured after 2 and 5 years. RESULTS: Osteophyte size was drastically reduced in S100A9-/- mice in ligaments and at medial femur and tibia on days 21 and 42 of collagenase-induced OA, in which synovial activation is high. In contrast, osteophyte size was not reduced in S100A9-/- mice during destabilised medial meniscus OA, in which synovial activation is scant. S100A8 increased expression and activation of matrix metalloproteinases during micromass chondrogenesis, thereby possibly increasing cartilage matrix remodelling allowing for larger osteophytes. Interestingly, early symptomatic OA participants of the CHECK study with osteophyte progression after 2 and 5 years had elevated S100A8/A9 plasma levels at baseline, while C-reactive protein, erythrocyte sedimentation rate and cartilage oligomeric matrix protein were not elevated at baseline. CONCLUSIONS: S100A8/A9 aggravate osteophyte formation in experimental OA with high synovial activation and may be used to predict osteophyte progression in early symptomatic human OA.

  • op0024 the function of pstpip1 and s100a8 s100a9 in hyperzincaemia hypercalprotectinaemia and the papa syndrom
    Annals of the Rheumatic Diseases, 2013
    Co-Authors: Selina Kathleen Fassl, Judith Austermann, Thomas J. Vogl, Johannes Roth
    Abstract:

    Background Hypercalprotectinaemia and hyperzincaemia is a very rare autoinflammatory syndrome that is characterized by excessively high S100A8/S100A9 complex (calprotectin) serum concentrations (0.9-12.0 g/l, normal range Objectives The molecular link between PSTPIP1 mutations and elevated S100A8/S100A9 concentrations is currently unknown. The present project focuses therefore on the identification of molecular links between PSTPIP1 and S100A8/S100A9 and the potential function of PSTPIP1 for the release of S100A8/S100A9. Methods The intracellular distribution of E250K and wildtype PSTPIP1 was determined in transfected cell lines by immunofluorescence analysis. The interactions between PSTPIP1, S100A8/S100A9 and microtubules were characterized via immunoprecipitations. These interaction studies were confirmed and further characterized by in vitro interaction studies using a modified S100A8/S100A9-ELISA and microtubule binding assays. Results The immunofluorescence and immunoprecipitation results point towards an interaction between PSTPIP1 and S100A8/S100A9 in vivo . Moreover we could specify this interaction in vitro as direct and strictly calcium-dependent. Using several deletion constructs of PSTPIP1 we have some first evidences indicating that the S100A8/S100A9 binding motif is located within the same region described to be mutated in hyperzincaemia and hypercalprotectinaemia patients. Microtubule co-sedimentation experiments indicate a mutual interference of PSTPIP1 and S100A8/S100A9 on their interaction with microtubules which is altered by using the E250K mutated PSTPIP1. Conclusions PSTPIP1 and S100A8/S100A9 directly interact in a calcium-dependent manner and the E250K mutation is apparently located within the S100A8/S100A9 binding region. Therefore this mutation might have an influence on the S100A8/S100A9-PSTPIP1 interaction. In addition PSTPIP1 and S100A8/S100A9 seem to have a regulatory function on their tubulin binding capability. This in turn might be of important relevance for the tubulin-dependent secretion of the S100A8/S100A9 proteins and putatively the cause for the high serum concentrations of S100A8/S100A9 in hyperzincaemia and hypercalprotectinaemia patients. References Vogl et al. (2007) Nat. Med. 13, 1042-1049; Rammes et al. (1997) J. Biol. Chem. 272, 9496-9502; Wise et al. (2002) Hum. Mol. Gen. 11(8), 961-969. Disclosure of Interest None Declared

  • active involvement of alarmins s100a8 and s100a9 in the regulation of synovial activation and joint destruction during mouse and human osteoarthritis
    Arthritis & Rheumatism, 2012
    Co-Authors: Peter L E M Van Lent, R.f. Schelbergen, Annet W. Sloetjes, Johannes Roth, Arjen B. Blom, Thomas Vogl, Floris P J G Lafeber, W F Lems, Hans Cats, W.b. Van Den Berg
    Abstract:

    Objective To investigate whether alarmins S100A8 and S100A9 are involved in mediating cartilage destruction during murine and human osteoarthritis (OA). Methods Two different murine models of OA that differed in terms of synovial activation were compared. Cartilage destruction was measured histologically. Synovial biopsy and serum samples from OA patients were derived from the Cohort Hip and Cohort Knee (CHECK) patients with symptomatic early OA. Expression of mediators in the synovium was measured by reverse transcription–polymerase chain reaction analysis and immunolocalization. Results In collagenase-induced OA, which showed marked synovial activation, interleukin-1β was expressed at significant levels only during the early stages of disease, whereas S100A8 and S100A9 expression remained high for a prolonged period of time (up to day 21 after induction). In S100A9-knockout mice, we found a major impact of S100A8 and S100A9 on synovial activation (62% inhibition) and OA cartilage destruction (45–73% inhibition) as compared to wild-type controls. In contrast, in the surgically induced destabilized medial meniscus model, in which synovial involvement is scant, we found no role of S100A8 and S100A9 in the focal OA cartilage destruction. Examination of arthroscopic synovial biopsy samples from patients in the early symptomatic OA CHECK cohort revealed substantial levels of S100A8 and S100A9 messenger RNA and protein, which correlated significantly with synovial lining thickness, cellularity in the subintima, and joint destruction. Levels of S100A8/A9 serum protein were significantly enhanced (19%) at baseline in patients who had pronounced progression of joint destruction after 2 years. Conclusion Our data suggest that the S100A8 and S100A9 proteins are crucially involved in synovial activation and cartilage destruction during OA and that high levels may predict joint destruction in humans with OA.

  • alarmins s100a8 and s100a9 elicit a catabolic effect in human osteoarthritic chondrocytes that is dependent on toll like receptor 4
    Arthritis & Rheumatism, 2012
    Co-Authors: R.f. Schelbergen, Annet W. Sloetjes, Johannes Roth, Thomas Vogl, A B Blom, Martijn H J Van Den Bosch, Shahla Abdollahiroodsaz, Wim B Schreurs, John S Mort, W.b. Van Den Berg
    Abstract:

    Objective S100A8 and S100A9 are two Ca2+ binding proteins classified as damage-associated molecular patterns or alarmins that are found in high amounts in the synovial fluid of osteoarthritis (OA) patients. The purpose of this study was to investigate whether S100A8 and/or S100A9 can interact with chondrocytes from OA patients to increase catabolic mediators. Methods Using immunohistochemistry, we stained for S100A8 and S100A9 protein, matrix metalloproteinases (MMPs), and a cartilage-breakdown epitope specific for MMPs (VDIPEN) in cartilage from OA donors. Isolated chondrocytes or explants from OA and non-OA donors were stimulated with S100A8 and/or S100A9. Messenger RNA and protein levels of MMPs, cytokines, and cartilage matrix molecules were determined with quantitative reverse transcription–polymerase chain reaction and Luminex techniques, respectively. For receptor blocking studies, specific inhibitors for Toll-like receptor 4 (TLR-4), receptor for advanced glycation end products (RAGE), and carboxylated glycans were used. Results In cartilage from OA patients, the expression of S100A8 and S100A9 protein close to chondrocytes was associated with proteoglycan depletion and expression of MMP-1, MMP-3, and VDIPEN. Stimulation of chondrocytes with S100A8 and S100A9 caused a strong up-regulation of catabolic markers (MMPs 1, 3, 9, and 13, interleukin-6 [IL-6], IL-8, and monocyte chemotactic protein 1) and down-regulation of anabolic markers (aggrecan and type II collagen), thereby favoring cartilage breakdown. Blocking TLR-4, but not carboxylated glycans or RAGE, inhibited the S100 effect. The catabolic S100 effect was significantly more pronounced in chondrocytes from OA patients as compared to those from non-OA patients, possibly due to higher TLR-4 expression. Conclusion S100A8 and S100A9 have a catabolic effect on human chondrocytes that is TLR-4 dependent. OA chondrocytes are more sensitive than normal chondrocytes to S100 stimulation.

Arne Skerra - One of the best experts on this subject based on the ideXlab platform.

  • the crystal structure of the human s100a8 s100a9 2 heterotetramer calprotectin illustrates how conformational changes of interacting α helices can determine specific association of two ef hand proteins
    Journal of Molecular Biology, 2007
    Co-Authors: Ingo P Korndorfer, Florian Brueckner, Arne Skerra
    Abstract:

    Abstract The EF-hand proteins S100A8 and S100A9 are important calcium signalling proteins that are involved in wound healing and provide clinically relevant markers of inflammatory processes, such as rheumatoid arthritis and inflammatory bowel disease. Both can form homodimers via distinct modes of association, probably of lesser stability in the case of S100A9, whereas in the presence of calcium S100A8 and S100A9 associate to calprotectin, the physiologically active heterooligomer. Here we describe the crystal structure of the (S100A8/S100A9)2 heterotetramer at 1.8 A resolution. Its quaternary structure illustrates how specific heteroassociation is energetically driven by a more extensive burial of solvent accessible surface areas in both proteins, most pronounced for S100A9, thus leading to a dimer of heterodimers. A major contribution to tetramer association is made by the canonical calcium binding loops in the C-terminal halves of the two proteins. The mode of heterodimerisation in calprotectin more closely resembles the subunit association previously observed in the S100A8 homodimer and provides trans stabilisation for S100A9, which manifests itself in a significantly elongated C-terminal α-helix in the latter. As a consequence, two different putative zinc binding sites emerge at the S100A8/S100A9 subunit interface. One of these corresponds to a high affinity arrangement of three His residues and one Asp side-chain, which is unique to the heterotetramer. This structural feature explains the well known Zn2+ binding activity of calprotectin, whose overexpression can cause strong dysregulation of zinc homeostasis with severe clinical symptoms.

  • the crystal structure of the human s100a8 s100a9 2 heterotetramer calprotectin illustrates how conformational changes of interacting alpha helices can determine specific association of two ef hand proteins
    Journal of Molecular Biology, 2007
    Co-Authors: Ingo P Korndorfer, Florian Brueckner, Arne Skerra
    Abstract:

    The EF-hand proteins S100A8 and S100A9 are important calcium signalling proteins that are involved in wound healing and provide clinically relevant markers of inflammatory processes, such as rheumatoid arthritis and inflammatory bowel disease. Both can form homodimers via distinct modes of association, probably of lesser stability in the case of S100A9, whereas in the presence of calcium S100A8 and S100A9 associate to calprotectin, the physiologically active heterooligomer. Here we describe the crystal structure of the (S100A8/S100A9)(2) heterotetramer at 1.8 A resolution. Its quaternary structure illustrates how specific heteroassociation is energetically driven by a more extensive burial of solvent accessible surface areas in both proteins, most pronounced for S100A9, thus leading to a dimer of heterodimers. A major contribution to tetramer association is made by the canonical calcium binding loops in the C-terminal halves of the two proteins. The mode of heterodimerisation in calprotectin more closely resembles the subunit association previously observed in the S100A8 homodimer and provides trans stabilisation for S100A9, which manifests itself in a significantly elongated C-terminal alpha-helix in the latter. As a consequence, two different putative zinc binding sites emerge at the S100A8/S100A9 subunit interface. One of these corresponds to a high affinity arrangement of three His residues and one Asp side-chain, which is unique to the heterotetramer. This structural feature explains the well known Zn(2+) binding activity of calprotectin, whose overexpression can cause strong dysregulation of zinc homeostasis with severe clinical symptoms.

Thomas Vogl - One of the best experts on this subject based on the ideXlab platform.

  • autoinhibitory regulation of s100a8 s100a9 alarmin activity locally restricts sterile inflammation
    Journal of Clinical Investigation, 2018
    Co-Authors: Thomas Vogl, Athanasios Stratis, Viktor Wixler, Tom Voller, Sumita Thurainayagam, Selina K Jorch, Stefanie Zenker, Alena Dreiling, Deblina Chakraborty, Mareike Frohling
    Abstract:

    Autoimmune diseases, such as psoriasis and arthritis, show a patchy distribution of inflammation despite systemic dysregulation of adaptive immunity. Thus, additional tissue-derived signals, such as danger-associated molecular patterns (DAMPs), are indispensable for manifestation of local inflammation. S100A8/S100A9 complexes are the most abundant DAMPs in many autoimmune diseases. However, regulatory mechanisms locally restricting DAMP activities are barely understood. We now unravel for the first time, to our knowledge, a mechanism of autoinhibition in mice and humans restricting S100-DAMP activity to local sites of inflammation. Combining protease degradation, pull-down assays, mass spectrometry, and targeted mutations, we identified specific peptide sequences within the second calcium-binding EF-hands triggering TLR4/MD2-dependent inflammation. These binding sites are free when S100A8/S100A9 heterodimers are released at sites of inflammation. Subsequently, S100A8/S100A9 activities are locally restricted by calcium-induced (S100A8/S100A9)2 tetramer formation hiding the TLR4/MD2-binding site within the tetramer interphase, thus preventing undesirable systemic effects. Loss of this autoinhibitory mechanism in vivo results in TNF-α-driven fatal inflammation, as shown by lack of tetramer formation in crossing S100A9-/- mice with 2 independent TNF-α-transgene mouse strains. Since S100A8/S100A9 is the most abundant DAMP in many inflammatory diseases, specifically blocking the TLR4-binding site of active S100 dimers may represent a promising approach for local suppression of inflammatory diseases, avoiding systemic side effects.

  • pathogenic role of the damage associated molecular patterns s100a8 and s100a9 in coxsackievirus b3 induced myocarditis
    Circulation-heart Failure, 2017
    Co-Authors: Irene Muller, Thomas Vogl, Kathleen Pappritz, Kapka Miteva, Konstantinos Savvatis, David Rohde, Patrick Most, Dirk Lassner, Burkert Pieske, Uwe Kuhl
    Abstract:

    Background: The alarmins S100A8 and S100A9 are damage-associated molecular patterns, which play a pivotal role in cardiovascular diseases, inflammation, and viral infections. We aimed to investigate their role in Coxsackievirus B3 (CVB3)–induced myocarditis. Methods and Results: S100A8 and S100A9 mRNA expression was 13.0-fold ( P =0.012) and 5.1-fold ( P =0.038) higher in endomyocardial biopsies from patients with CVB3-positive myocarditis compared with controls, respectively. Elimination of CVB3 led to a downregulation of these alarmins. CVB3-infected mice developed an impaired left ventricular function and displayed an increased left ventricular S100A8 and S100A9 protein expression versus controls. In contrast, CVB3-infected S100A9 knockout mice, which are also a complete knockout for S100A8 on protein level, showed an improved left ventricular function, which was associated with a reduced cardiac inflammatory and oxidative response, and lower CVB3 copy number compared with wild-type CVB3 mice. Exogenous application of S100A8 to S100A9 knockout CVB3 mice induced a severe myocarditis similar to wild-type CVB3 mice. In CVB3-infected HL-1 cells, S100A8 and S100A9 enhanced oxidative stress and CVB3 copy number compared with unstimulated infected cells. In CVB3-infected RAW macrophages, both alarmins increased MIP-2 (macrophage inflammatory protein-2) chemokine expression, which was reduced in CVB3 S100A8 knockdown versus scrambled siRNA CVB3 cells. Conclusions: S100A8 and S100A9 aggravate CVB3-induced myocarditis and might serve as therapeutic targets in inflammatory cardiomyopathies.

  • 01 03 ttp s100a9 deficient mice promote a tnf dependent psoriatic arthritis phenotype triggered by the bacterial environment
    Annals of the Rheumatic Diseases, 2017
    Co-Authors: Athanasios Stratis, Johannes Roth, Thomas Vogl, Mareike Frohling, Karin Loser, Peter Paruzel, Perry J Blackshear, Debbie Stumpo, Thomas Pap
    Abstract:

    Background Psoriatic-Arthritis (PsA) is a type of inflammatory chronic arthritis with a seronegative spondyloarthropathy and associated psoriasis. The Danger-Associated Molecular Pattern molecules (DAMPs) S100A8 and S100A9 are both antimicrobial proteins with chemotactic activity and are the most abundant DAMPs expressed during many inflammatory disorders. The expression of the S100A8/S100A9-complex is highly elevated in psoriasis and psoriatic arthritis. However, the mechanisms that regulate S100A8/S100A9-complex-activities are poorly understood, which has led us to examine the role of S100A8 and S100A9 under chronic inflammatory conditions. Material and methods We crossed S100A9-deficient mice with TTP (tristetraprolin)-deficient mice into a systemic inflammatory model featuring high levels of TNF with an arthritic joint destruction phenotype. Disease progression in TTP-/- x S100A9-/- mice was analysed by immunostaining, immunohistochemistry and the adapted PASI-score. To neutralise TNF in TTP-/- x S100A9-/- mice we used an aTNF-inhibiting monoclonal antibody already in clinical use for therapy of arthritis and psoriasis. To measure altered protein levels we used Western blot analysis. Primary keratinocytes were isolated of the skin from newborn mice and infected with E.coli isolated from the faeces of mice. Results TTP/S100A9 deficiency led to highly elevated levels of the S100A9 complex partner S100A8 in the epidermis and to a severe psoriatic phenotype of TTP-/- x S100A9-/- mice. Furthermore the mice showed an accelerated course of arthritis compared to TTP-/- mice, including increased articular cartilage loss and bone destruction. Inhibition of TNF by application of anti-TNF clearly reduced the psoriatic phenotype of TTP-/- x S100A9-/- mice. Additionally, the reduction of the environmental bacterial levels led to a milder phenotype and decelerated pathogenesis. The in vitro infection of isolated keratinocytes with isolated E.coli resulted in a high expression of S100A8. Conclusions The data reveal that the S100A8/S100A9-complex acts not only as a systemic danger signal molecule, but is also TNF dependent and is essential for the regulation of inflammation. The loss of S100A9 led to a disregulated inflammatory response and this to a severe psoriasis with enhanced cartilage and bone destruction. Furthermore, an exogenic bacterial factor, such as E. coli, is also demonstrated to be important in the activation of the disease.

  • alarmins s100a8 s100a9 aggravate osteophyte formation in experimental osteoarthritis and predict osteophyte progression in early human symptomatic osteoarthritis
    Annals of the Rheumatic Diseases, 2016
    Co-Authors: R.f. Schelbergen, W. De Munter, M.h. Van Den Bosch, Annet W. Sloetjes, Johannes Roth, Thomas Vogl, W.b. Van Den Berg, Peter M Van Der Kraan, Floris P J G Lafeber, Arjen B. Blom
    Abstract:

    OBJECTIVE: Alarmins S100A8 and S100A9 are major products of activated macrophages regulating cartilage damage and synovial activation during murine and human osteoarthritis (OA). In the current study, we investigated whether S100A8 and S100A9 are involved in osteophyte formation during experimental OA and whether S100A8/A9 predicts osteophyte progression in early human OA. METHODS: OA was elicited in S100A9-/- mice in two experimental models that differ in degree of synovial activation. Osteophyte size, S100A8, S100A9 and VDIPEN neoepitope was measured histologically. Chondrogenesis was induced in murine mesenchymal stem cells in the presence of S100A8. Levels of S100A8/A9 were determined in plasma of early symptomatic OA participants of the Cohort Hip and Cohort Knee (CHECK) cohort study and osteophytes measured after 2 and 5 years. RESULTS: Osteophyte size was drastically reduced in S100A9-/- mice in ligaments and at medial femur and tibia on days 21 and 42 of collagenase-induced OA, in which synovial activation is high. In contrast, osteophyte size was not reduced in S100A9-/- mice during destabilised medial meniscus OA, in which synovial activation is scant. S100A8 increased expression and activation of matrix metalloproteinases during micromass chondrogenesis, thereby possibly increasing cartilage matrix remodelling allowing for larger osteophytes. Interestingly, early symptomatic OA participants of the CHECK study with osteophyte progression after 2 and 5 years had elevated S100A8/A9 plasma levels at baseline, while C-reactive protein, erythrocyte sedimentation rate and cartilage oligomeric matrix protein were not elevated at baseline. CONCLUSIONS: S100A8/A9 aggravate osteophyte formation in experimental OA with high synovial activation and may be used to predict osteophyte progression in early symptomatic human OA.

  • active involvement of alarmins s100a8 and s100a9 in the regulation of synovial activation and joint destruction during mouse and human osteoarthritis
    Arthritis & Rheumatism, 2012
    Co-Authors: Peter L E M Van Lent, R.f. Schelbergen, Annet W. Sloetjes, Johannes Roth, Arjen B. Blom, Thomas Vogl, Floris P J G Lafeber, W F Lems, Hans Cats, W.b. Van Den Berg
    Abstract:

    Objective To investigate whether alarmins S100A8 and S100A9 are involved in mediating cartilage destruction during murine and human osteoarthritis (OA). Methods Two different murine models of OA that differed in terms of synovial activation were compared. Cartilage destruction was measured histologically. Synovial biopsy and serum samples from OA patients were derived from the Cohort Hip and Cohort Knee (CHECK) patients with symptomatic early OA. Expression of mediators in the synovium was measured by reverse transcription–polymerase chain reaction analysis and immunolocalization. Results In collagenase-induced OA, which showed marked synovial activation, interleukin-1β was expressed at significant levels only during the early stages of disease, whereas S100A8 and S100A9 expression remained high for a prolonged period of time (up to day 21 after induction). In S100A9-knockout mice, we found a major impact of S100A8 and S100A9 on synovial activation (62% inhibition) and OA cartilage destruction (45–73% inhibition) as compared to wild-type controls. In contrast, in the surgically induced destabilized medial meniscus model, in which synovial involvement is scant, we found no role of S100A8 and S100A9 in the focal OA cartilage destruction. Examination of arthroscopic synovial biopsy samples from patients in the early symptomatic OA CHECK cohort revealed substantial levels of S100A8 and S100A9 messenger RNA and protein, which correlated significantly with synovial lining thickness, cellularity in the subintima, and joint destruction. Levels of S100A8/A9 serum protein were significantly enhanced (19%) at baseline in patients who had pronounced progression of joint destruction after 2 years. Conclusion Our data suggest that the S100A8 and S100A9 proteins are crucially involved in synovial activation and cartilage destruction during OA and that high levels may predict joint destruction in humans with OA.

Ingo P Korndorfer - One of the best experts on this subject based on the ideXlab platform.

  • the crystal structure of the human s100a8 s100a9 2 heterotetramer calprotectin illustrates how conformational changes of interacting α helices can determine specific association of two ef hand proteins
    Journal of Molecular Biology, 2007
    Co-Authors: Ingo P Korndorfer, Florian Brueckner, Arne Skerra
    Abstract:

    Abstract The EF-hand proteins S100A8 and S100A9 are important calcium signalling proteins that are involved in wound healing and provide clinically relevant markers of inflammatory processes, such as rheumatoid arthritis and inflammatory bowel disease. Both can form homodimers via distinct modes of association, probably of lesser stability in the case of S100A9, whereas in the presence of calcium S100A8 and S100A9 associate to calprotectin, the physiologically active heterooligomer. Here we describe the crystal structure of the (S100A8/S100A9)2 heterotetramer at 1.8 A resolution. Its quaternary structure illustrates how specific heteroassociation is energetically driven by a more extensive burial of solvent accessible surface areas in both proteins, most pronounced for S100A9, thus leading to a dimer of heterodimers. A major contribution to tetramer association is made by the canonical calcium binding loops in the C-terminal halves of the two proteins. The mode of heterodimerisation in calprotectin more closely resembles the subunit association previously observed in the S100A8 homodimer and provides trans stabilisation for S100A9, which manifests itself in a significantly elongated C-terminal α-helix in the latter. As a consequence, two different putative zinc binding sites emerge at the S100A8/S100A9 subunit interface. One of these corresponds to a high affinity arrangement of three His residues and one Asp side-chain, which is unique to the heterotetramer. This structural feature explains the well known Zn2+ binding activity of calprotectin, whose overexpression can cause strong dysregulation of zinc homeostasis with severe clinical symptoms.

  • the crystal structure of the human s100a8 s100a9 2 heterotetramer calprotectin illustrates how conformational changes of interacting alpha helices can determine specific association of two ef hand proteins
    Journal of Molecular Biology, 2007
    Co-Authors: Ingo P Korndorfer, Florian Brueckner, Arne Skerra
    Abstract:

    The EF-hand proteins S100A8 and S100A9 are important calcium signalling proteins that are involved in wound healing and provide clinically relevant markers of inflammatory processes, such as rheumatoid arthritis and inflammatory bowel disease. Both can form homodimers via distinct modes of association, probably of lesser stability in the case of S100A9, whereas in the presence of calcium S100A8 and S100A9 associate to calprotectin, the physiologically active heterooligomer. Here we describe the crystal structure of the (S100A8/S100A9)(2) heterotetramer at 1.8 A resolution. Its quaternary structure illustrates how specific heteroassociation is energetically driven by a more extensive burial of solvent accessible surface areas in both proteins, most pronounced for S100A9, thus leading to a dimer of heterodimers. A major contribution to tetramer association is made by the canonical calcium binding loops in the C-terminal halves of the two proteins. The mode of heterodimerisation in calprotectin more closely resembles the subunit association previously observed in the S100A8 homodimer and provides trans stabilisation for S100A9, which manifests itself in a significantly elongated C-terminal alpha-helix in the latter. As a consequence, two different putative zinc binding sites emerge at the S100A8/S100A9 subunit interface. One of these corresponds to a high affinity arrangement of three His residues and one Asp side-chain, which is unique to the heterotetramer. This structural feature explains the well known Zn(2+) binding activity of calprotectin, whose overexpression can cause strong dysregulation of zinc homeostasis with severe clinical symptoms.

Claus W Heizmann - One of the best experts on this subject based on the ideXlab platform.

  • immunolocalization of the calcium binding s100a1 s100a5 and s100a6 proteins in the dog cochlea during postnatal development
    Developmental Brain Research, 2001
    Co-Authors: Angelique Coppens, Beat W Schafer, Claus W Heizmann, Robert Kiss, Luc Poncelet
    Abstract:

    The immunolocalization of three members of the S100 calcium-binding protein family was investigated in the dog cochlea during normal postnatal development. Sections of decalcified and paraffin-embedded cochleae from 16 beagle puppies aged from birth to 3 months were treated with polyclonal antisera raised against the human recombinant S100A1, S100A5, and S100A6 proteins. At birth, in the dog cochlea, S100A1 was expressed in the immature Deiter's cells, and slightly in the pillar cells. From the second week, S100A1 was detected in the supporting structures of the organ of Corti, i.e. the Deiter's, the pillar, the border, and the Hensen's cells, and in the reticular membrane. From birth onwards, S100A5 remained a neuronal-specific protein, only located in a subpopulation of neurons in the spiral ganglion. S100A6 was not expressed at birth. From the second week of life, the Schwann cells and nerve sheaths in the modiolus, in the spiral ganglion, and running in the direction of the organ of Corti exhibited S100A6-labeling. From the 12th postnatal day, some scattered intermediate cells started to express S100A6 protein in the stria vascularis. The number of labeled intermediate cells increased during the third week. At adult stage, the intermediate cells were S100A6-stained with cytoplasmic labeling throughout the stria vascularis from the base to the apex of the cochlea. None of the other cochlear structures expressed the S100 proteins under study during the postnatal development of the dog cochlea. The S100A1, S100A5, S100A6 immunostaining was limited to specific cell types in dog cochlea. These S100 proteins were useful markers in the study of supporting cells, neurons, nerve fibers sheaths and stria vascularis (S100A6) during the normal postnatal development of the dog cochlea.

  • s100 proteins in corpora amylacea from normal human brain
    Brain Research, 2000
    Co-Authors: Daphne Hoyaux, Beat W Schafer, Christine Decaestecker, Isabelle Salmon, Thomas Vogl, Claus W Heizmann, Robert Kiss, Roland Pochet
    Abstract:

    Corpora amylacea (C.A.) also named polyglucosan bodies (P.B.) are one of the hallmarks of normal brain aging. Although their functions are not yet clear, C.A. increase in number in patients suffering from neurodegenerative diseases. C.A. contain 88% of hexoses and 4% of proteins. Most of the proteins in C.A. are aging or stress proteins such as heat shock proteins, ubiquitinated proteins and advanced glycation end products which are also proinflammatory products. Stimulated by the potential role played by some S100 proteins in the inflammatory process which may be triggered in C.A., we investigated, by immunohistochemistry, the presence of different S100 proteins (S100A1, S100A2, S100A3, S100A4, S100A5, S100A6, S100A8, S100A9, S100A12 and S100B) in C.A. from normal human brain. Among the ten S100 proteins analyzed, nine (S100A) were detected in C.A. Three S100 proteins (S100A8, S100A9, S100A12) which are highly expressed in activated macrophages and used as inflammatory markers were detected in C.A. S100A8 was, in addition, found in thick neuronal processes from the pons. One (S100B) could not be found in C.A. although it was highly expressed in astrocytes. In C.A., the staining intensity was estimated by computer-assisted microscopy and gave the following order: S100A1 congruent withS100A8 congruent with S100A9>S100A5> or =S100A4>S100A12>S100A6> S100A2=S100A3. The potential inflammatory role played by S100 proteins in C.A. is discussed.

  • ca 2 binding proteins s100a6 and s100b in primary cutaneous melanoma
    Journal of Cutaneous Pathology, 1997
    Co-Authors: R Boni, Beat W Schafer, Claus W Heizmann, A Doguoglu, Evelyn C Ilg, R Dummer, G Burg
    Abstract:

    Purpose: Commercially available polyclonal antibodies against a mixture of bovine brain S100 proteins have become an established marker for immunohistochemical characterization of malignant melanoma. However, the commercially available antibodies used are undefined and to date, 13 different human S100 proteins are known. The purpose of this study was to examine the expression of 4 newly available polyclonal antibodies against the human recombinant Ca 2+ -binding S100 proteins, S100A1, S100A2, S100A4 and S100A6, in cutaneous melanoma and to correlate these findings with the standard S100 staining as well as with the metastatic potential of the primary. Methods: 39 formalin-fixed paraffin-embedded primary cutaneous melanomas were incubated with polyclonal antibodies against recombinant human S100 proteins using the APAAP method. The extent of staining was qualitatively assessed and a staining index was calculated. Findings were correlated to the metastatic potential and the overall survival in all patients. Results: Staining with antibodies against human S100A6 as well as with antibodies against conventional bovine S100 proteins was positive in all specimens. No correlation was found between the extent of protein expression and patients' outcome for standard S100 staining as well as for S100A6. S100A1, S100A2 and S100A4 stainings could not be used for statistical analysis due to their low expression in melanoma. Conclusion: Staining was positive using S100A6 antibodies in all specimens, the quality being inferior to the commercially available S100 antibody. Highly specific and well characterized antibodies against the individual S100 proteins are now available for future immunohistochemical characterization studies in melanomas.

  • expression pattern of s100 calcium binding proteins in human tumors
    International Journal of Cancer, 1996
    Co-Authors: Beat W Schafer, Claus W Heizmann
    Abstract:

    The S100 Ca2+-binding proteins recently became of major interest because of their differential expression in neoplastic tissues, their involvement in metastatic processes, and the clustered organization of at least 10 S100 genes on human chromosome 1q21, a region frequently rearranged in several tumors. As a first attempt towards a specific and differentiated immunohistochemical classification of human tumors, we produced, purified and characterized a number of human recombinant S100 proteins and raised specific polyclonal antibodies. Their distinct cellular and intracellular localization was examined by immunohistochemical methods in normal and cancerogenic human tissues and cell lines. S100A1 and S100A2 can be detected in a few normal tissues only, whereas S100A4, S100A6, and S100B are expressed at higher levels in cancer tissues. In the future, these S100 antibodies will potentially be of great value in cancer diagnosis and therapy. © 1996 Wiley-Liss, Inc.