The Experts below are selected from a list of 840843 Experts worldwide ranked by ideXlab platform
Yasuyoshi Ueki - One of the best experts on this subject based on the ideXlab platform.
-
SH3BP2 Deficiency Ameliorates Murine Systemic Lupus Erythematosus
2020Co-Authors: Kyoko Kawahara, Tomoyuki Mukai, Yasuyoshi Ueki, Akiko Nagasu, Masanori Iseki, Hajime Nagasu, Takahiko Akagi, Shoko Tsuji, Sumie Hiramatsu-asano, Katsuhiko IshiharaAbstract:Abstract Background: The adaptor protein Src homology 3 domain-binding protein 2 (SH3BP2) is widely expressed in immune cells, such as myeloid cells, B cells, and T cells. It controls intracellular signaling pathways, including Syk and Src. The present study was undertaken to investigate the role of SH3BP2 in a murine systemic lupus erythematosus model.Methods: For the lupus model, we used Faslpr/lpr mice (C57BL/6 background). Clinical and immunological phenotypes were compared between Faslpr/lpr and SH3BP2-deficient Faslpr/lpr mice. Splenomegaly and renal involvement were assessed in 35-week-old mice. Serum levels of anti-dsDNA antibody and rheumatoid factor were determined using ELISA. Lymphocyte subsets in the spleen were analyzed by flow cytometry. To examine the role of SH3BP2 in specific cells, B cell-specific SH3BP2-deficient lupus mice were generated and analyzed; T cells and bone marrow-derived dendritic cells and macrophages were analyzed in vitro. Results: SH3BP2 deficiency significantly reduced lupus-like phenotypes, presented as splenomegaly, renal involvement, elevated serum anti-dsDNA antibody and rheumatoid factor, and increased splenic B220+CD4-CD8- T cells. Notably, SH3BP2 deficiency in B cells did not rescue the lupus-like phenotypes. Furthermore, SH3BP2 deficiency did not substantially affect the characteristics of T cells and macrophages in vitro. Interestingly, SH3BP2 deficiency suppressed the differentiation of dendritic cells in vitro and reduced the number of dendritic cells in the spleen of the lupus-prone mice.Conclusions: SH3BP2 deficiency ameliorated clinical and immunological manifestations in lupus-prone mice, possibly via targeting dendritic cell differentiation. Modulating SH3BP2 expression could thus provide a novel therapeutic approach to autoimmune diseases.
-
Microbe-Dependent Exacerbated Alveolar Bone Destruction in Heterozygous Cherubism Mice.
JBMR plus, 2020Co-Authors: Mizuho Kittaka, Tetsuya Yoshimoto, Collin Schlosser, Mikihito Kajiya, Hidemi Kurihara, Ernst J. Reichenberger, Yasuyoshi UekiAbstract:Cherubism (OMIM#118400) is a craniofacial disorder characterized by destructive jaw expansion. Gain-of-function mutations in SH3-domain binding protein 2 (SH3BP2) are responsible for this rare disorder. We have previously shown that homozygous knock-in (KI) mice (SH3BP2 KI/KI ) recapitulate human cherubism by developing inflammatory lesions in the jaw. However, it remains unknown why heterozygous KI mice (SH3BP2 KI/+ ) do not recapitulate the excessive jawbone destruction in human cherubism, even though all mutations are heterozygous in humans. We hypothesized that SH3BP2 KI/+ mice need to be challenged for developing exacerbated jawbone destruction and that bacterial stimulation in the oral cavity may be involved in the mechanism. In this study, we applied a ligature-induced periodontitis model to SH3BP2 KI/+ mice to induce inflammatory alveolar bone destruction. Ligature placement induced alveolar bone resorption with gingival inflammation. Quantification of alveolar bone volume revealed that SH3BP2 KI/+ mice developed more severe bone loss (male: 43.0% ± 10.6%, female: 42.6% ± 10.4%) compared with SH3BP2 +/+ mice (male: 25.8% ± 4.0%, female: 30.9% ± 6.5%). Measurement of bone loss by the cement-enamel junction-alveolar bone crest distance showed no difference between SH3BP2 KI/+ and SH3BP2 +/+ mice. The number of osteoclasts on the alveolar bone surface was higher in male SH3BP2 KI/+ mice, but not in females, compared with SH3BP2 +/+ mice. In contrast, inflammatory cytokine levels in gingiva were comparable between SH3BP2 KI/+ and SH3BP2 +/+ mice with ligatures. Genetic deletion of the spleen tyrosine kinase in myeloid cells and antibiotic treatment suppressed alveolar bone loss in SH3BP2 KI/+ mice, suggesting that increased osteoclast differentiation and function mediated by SYK and accumulation of oral bacteria are responsible for the increased alveolar bone loss in SH3BP2 KI/+ mice with ligature-induced periodontitis. High amounts of oral bacterial load caused by insufficient oral hygiene could be a trigger for the initiation of jawbone destruction in human cherubism. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
-
Investigating global gene expression changes in a murine model of cherubism
Bone, 2020Co-Authors: Tulika Sharma, Yasuyoshi Ueki, Ernst J. Reichenberger, Justin Cotney, Vijender Singh, Archana Sanjay, Peter MayeAbstract:Cherubism is a rare genetic disorder caused primarily by mutations in SH3BP2 resulting in excessive bone resorption and fibrous tissue overgrowth in the lower portions of the face. Bone marrow derived cell cultures derived from a murine model of cherubism display poor osteogenesis and spontaneous osteoclast formation. To develop a deeper understanding for the potential underlying mechanisms contributing to these phenotypes in mice, we compared global gene expression changes in hematopoietic and mesenchymal cell populations between cherubism and wild type mice. In the hematopoietic population, not surprisingly, upregulated genes were significantly enriched for functions related to osteoclastogenesis. However, these upregulated genes were also significantly enriched for functions associated with inflammation including arachidonic acid/prostaglandin signaling, regulators of coagulation and autoinflammation, extracellular matrix remodeling, and chemokine expression. In the mesenchymal population, we observed down regulation of osteoblast and adventitial reticular cell marker genes. Regulators of BMP and Wnt pathway associated genes showed numerous changes in gene expression, likely implicating the down regulation of BMP signaling and possibly the activation of certain Wnt pathways. Analyses of the cherubism derived mesenchymal population also revealed interesting changes in gene expression related to inflammation including the expression of distinct granzymes, chemokines, and sulfotransferases. These studies reveal complex changes in gene expression elicited from a cherubic mutation in SH3BP2 that are informative to the mechanisms responding to inflammatory stimuli and repressing osteogenesis. The outcomes of this work are likely to have relevance not only to cherubism, but other inflammatory conditions impacting the skeleton.
-
Alveolar Bone Protection by Targeting the SH3BP2-SYK Axis in Osteoclasts.
Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research, 2019Co-Authors: Mizuho Kittaka, Robert Rottapel, Tetsuya Yoshimoto, Collin Schlosser, Mikihito Kajiya, Hidemi Kurihara, Ernst J. Reichenberger, Yasuyoshi UekiAbstract:Periodontitis is a bacterially induced chronic inflammatory condition of the oral cavity where tooth-supporting tissues including alveolar bone are destructed. Previously, we have shown that the adaptor protein SH3-domain binding protein 2 (SH3BP2) plays a critical role in inflammatory response and osteoclastogenesis of myeloid lineage cells through spleen tyrosine kinase (SYK). In this study, we show that SH3BP2 is a novel regulator for alveolar bone resorption in periodontitis. Micro-CT analysis of SH3BP2-deficient (SH3BP2 -/- ) mice challenged with ligature-induced periodontitis revealed that SH3BP2 -/- mice develop decreased alveolar bone loss (male 14.9% ± 10.2%; female 19.0% ± 6.0%) compared with wild-type control mice (male 25.3% ± 5.8%; female 30.8% ± 5.8%). Lack of SH3BP2 did not change the inflammatory cytokine expression and osteoclast induction. Conditional knockout of SH3BP2 and SYK in myeloid lineage cells with LysM-Cre mice recapitulated the reduced bone loss without affecting both inflammatory cytokine expression and osteoclast induction, suggesting that the SH3BP2-SYK axis plays a key role in regulating alveolar bone loss by mechanisms that regulate the bone-resorbing function of osteoclasts rather than differentiation. Administration of a new SYK inhibitor GS-9973 before or after periodontitis induction reduced bone resorption without affecting inflammatory reaction in gingival tissues. In vitro, GS-9973 treatment of bone marrow-derived M-CSF-dependent macrophages suppressed tartrate-resistant acid phosphatase (TRAP)-positive osteoclast formation with decreased mineral resorption capacity even when GS-9973 was added after RANKL stimulation. Thus, the data suggest that SH3BP2-SYK is a novel signaling axis for regulating alveolar bone loss in periodontitis and that SYK can be a potential therapeutic target to suppress alveolar bone resorption in periodontal diseases. © 2019 American Society for Bone and Mineral Research. © 2019 American Society for Bone and Mineral Research.
-
SH3BP2 Gain-Of-Function Mutation Ameliorates Lupus Phenotypes in B6.MRL-Faslpr Mice
Cells, 2019Co-Authors: Akiko Nagasu, Tomoyuki Mukai, Yasuyoshi Ueki, Kyoko Kawahara, Masanori Iseki, Hajime Nagasu, Shoko Tsuji, Katsuhiko Ishihara, Naoki Kashihara, Yoshitaka MoritaAbstract:SH3 domain-binding protein 2 (SH3BP2) is an adaptor protein that is predominantly expressed in immune cells, and it regulates intracellular signaling. We had previously reported that a gain-of-function mutation in SH3BP2 exacerbates inflammation and bone loss in murine arthritis models. Here, we explored the involvement of SH3BP2 in a lupus model. SH3BP2 gain-of-function (P416R knock-in; SH3BP2KI/+) mice and lupus-prone B6.MRL-Faslpr mice were crossed to yield double-mutant (SH3BP2KI/+Faslpr/lpr) mice. We monitored survival rates and proteinuria up to 48 weeks of age and assessed renal damage and serum anti-double-stranded DNA antibody levels. Additionally, we analyzed B and T cell subsets in lymphoid tissues by flow cytometry and determined the expression of apoptosis-related molecules in lymph nodes. SH3BP2 gain-of-function mutation alleviated the poor survival rate, proteinuria, and glomerulosclerosis and significantly reduced serum anti-dsDNA antibody levels in SH3BP2KI/+Faslpr/lpr mice. Additionally, B220+CD4−CD8− T cell population in lymph nodes was decreased in SH3BP2KI/+Faslpr/lpr mice, which is possibly associated with the observed increase in cleaved caspase-3 and tumor necrosis factor levels. SH3BP2 gain-of-function mutation ameliorated clinical and immunological phenotypes in lupus-prone mice. Our findings offer better insight into the unique immunopathological roles of SH3BP2 in autoimmune diseases.
Marcel Deckert - One of the best experts on this subject based on the ideXlab platform.
-
Une mutation hétérozygote de SH3BP2 amplifie la réponse inflammatoire à l’infection des macrophages dans un modèle de chérubisme chez la souris
Medecine sciences : M S, 2015Co-Authors: Marcel Deckert, Virginie Prod 'hommeAbstract:Des mutations de SH3BP2 a l'origine du cherubisme Le cherubisme est une dysplasie cra-nio-faciale rare, caracterisee par un elargissement symetrique de la partie inferieure du visage qui donne au patient une apparence semblable a celle des cherubins de la Renaissance. Cette maladie genetique est transmise de maniere autosomique dominante. Les patients presentent une erosion importante des os de la mâchoire dans lesquels s'accumulent des kystes fibreux remplis de cel-lules multinucleees geantes de type osteoclaste. Les lesions apparaissent dans la petite enfance, entre 2 et 5 ans, et progressent jusqu'a la puberte pour regresser presque completement a l'âge adulte. Cette maladie reste benigne mais engendre des troubles importants de la face et de la denti-tion, associes a des problemes esthe-tiques et psychologiques qui neces-sitent une intervention chirurgicale dans les cas severes. La majorite des mutations associees au cherubisme affectent l'exon 9 du gene SH3BP2 codant pour 3BP2 ou SH3BP2 (Abl SH3 binding protein 2). Ces mutations conduisent au changement d'un unique acide amine dans la sequence R 415 SPPDG 420 de 3BP2 [1]. 3BP2 est une proteine adaptatrice que nous avions identifiee comme un partenaire de la proteine tyrosine kinase SYK [2] et d'autres molecules de signalisation comme les kinases SRC et les facteurs d'echange nucleotidique VAV. Ainsi, 3BP2 est impliquee dans l'activation de programmes transcriptionnels et cellulaires (comme le remodelage du reseau d'actine) via l'engagement de multiples recepteurs dans les reponses leucocytaires [3], la differenciation des osteoclastes [4] et le remodelage osseux [1]. L'etiologie du cherubisme est longtemps restee inconnue, mais le developpement de modeles chez la souris a permis d'importants pro-gres dans la comprehension des fac-teurs declencheurs de cette maladie enigmatique. Le knock-in des mutations P416R et G418R (respective-ment P418R et G420R chez l'homme) dans le gene SH3BP2 montre qu'un seul allele mutant n'est pas suffisant pour declencher la maladie chez la sou-ris. Les souris mutantes homozygotes developpent cependant une osteopo-rose severe et une inflammation sys-temique, avec des niveaux eleves de TNF- (tumor necrosis factor) serique, resultant d'une hyperactivation des voies de signalisation dependantes des kinases SRC et SYK et du facteur de transcription NFATc1 (nuclear factor of activated T-cells) dans les macro-phages et les osteoclastes. Ainsi, ces modeles definissent le cherubisme comme une maladie hereditaire auto-inflammatoire mediee par les cellules myeloides, et conferent a la mutation du gene SH3BP2 un role moteur dans cette maladie [5, 6]. Une avancee importante dans la comprehension du cherubisme est venue du laboratoire du Dr Rottapel, qui a identifie l'inter-action entre 3BP2 et la poly(ADP-ribosyl)polymerase tankyrase comme une etape cle dans la pathogenese de la maladie [7]. La fixation de tankyrase sur le motif RSPPDG de la proteine 3BP2 sauvage, en catalysant la poly(ADP-ribosyl)ation (PARyla-tion) de 3BP2, entraine sa polyubi-quitination par RNF146 (ring finger protein 146), une E3 ubiquitine ligase dependante de la PARylation des proteines. Cette sequence de modifications post-traductionnelles est suivie de la degradation de 3BP2 par le proteasome, assurant ainsi l'ho-meostasie proteique de 3BP2. Dans le cherubisme, ce mecanisme est defec-tueux car les mutations ponctuelles du motif RSPPDG de 3BP2 abolissent son interaction avec tankyrase, avec pour consequence une accumulation des proteines 3BP2 mutantes a l'ori-gine du syndrome auto-inflamma-toire observe [6, 7].
-
Une mutation hétérozygote de SH3BP2 amplifie la réponse inflammatoire à l'infection des macrophages dans un modèle de chérubisme chez la souris
médecine sciences, 2015Co-Authors: Marcel Deckert, Virginie Prod 'hommeAbstract:Des mutations de SH3BP2 à l'origine du chérubisme Le chérubisme est une dysplasie cra-nio-faciale rare, caractérisée par un élargissement symétrique de la partie inférieure du visage qui donne au patient une apparence semblable à celle des chérubins de la Renaissance. Cette maladie génétique est transmise de manière autosomique dominante. Les patients présentent une érosion importante des os de la mâchoire dans lesquels s'accumulent des kystes fibreux remplis de cel-lules multinucléées géantes de type ostéoclaste. Les lésions apparaissent dans la petite enfance, entre 2 et 5 ans, et progressent jusqu'à la puberté pour régresser presque complètement à l'âge adulte. Cette maladie reste bénigne mais engendre des troubles importants de la face et de la denti-tion, associés à des problèmes esthé-tiques et psychologiques qui néces-sitent une intervention chirurgicale dans les cas sévères. La majorité des mutations associées au chérubisme affectent l'exon 9 du gène SH3BP2 codant pour 3BP2 ou SH3BP2 (Abl SH3 binding protein 2). Ces mutations conduisent au changement d'un unique acide aminé dans la séquence R 415 SPPDG 420 de 3BP2 [1]. 3BP2 est une protéine adaptatrice que nous avions identifiée comme un partenaire de la protéine tyrosine kinase SYK [2] et d'autres molécules de signalisation comme les kinases SRC et les facteurs d'échange nucléotidique VAV. Ainsi, 3BP2 est impliquée dans l'activation de programmes transcriptionnels et cellulaires (comme le remodelage du réseau d'actine) via l'engagement de multiples récepteurs dans les réponses leucocytaires [3], la différenciation des ostéoclastes [4] et le remodelage osseux [1]. L'étiologie du chérubisme est longtemps restée inconnue, mais le développement de modèles chez la souris a permis d'importants pro-grès dans la compréhension des fac-teurs déclencheurs de cette maladie énigmatique. Le knock-in des mutations P416R et G418R (respective-ment P418R et G420R chez l'homme) dans le gène SH3BP2 montre qu'un seul allèle mutant n'est pas suffisant pour déclencher la maladie chez la sou-ris. Les souris mutantes homozygotes développent cependant une ostéopo-rose sévère et une inflammation sys-témique, avec des niveaux élevés de TNF- (tumor necrosis factor) sérique, résultant d'une hyperactivation des voies de signalisation dépendantes des kinases SRC et SYK et du facteur de transcription NFATc1 (nuclear factor of activated T-cells) dans les macro-phages et les ostéoclastes. Ainsi, ces modèles définissent le chérubisme comme une maladie héréditaire auto-inflammatoire médiée par les cellules myéloïdes, et confèrent à la mutation du gène SH3BP2 un rôle moteur dans cette maladie [5, 6]. Une avancée importante dans la compréhension du chérubisme est venue du laboratoire du Dr Rottapel, qui a identifié l'inter-action entre 3BP2 et la poly(ADP-ribosyl)polymérase tankyrase comme une étape clé dans la pathogenèse de la maladie [7]. La fixation de tankyrase sur le motif RSPPDG de la protéine 3BP2 sauvage, en catalysant la poly(ADP-ribosyl)ation (PARyla-tion) de 3BP2, entraîne sa polyubi-quitination par RNF146 (ring finger protein 146), une E3 ubiquitine ligase dépendante de la PARylation des protéines. Cette séquence de modifications post-traductionnelles est suivie de la dégradation de 3BP2 par le protéasome, assurant ainsi l'ho-méostasie protéique de 3BP2. Dans le chérubisme, ce mécanisme est défec-tueux car les mutations ponctuelles du motif RSPPDG de 3BP2 abolissent son interaction avec tankyrase, avec pour conséquence une accumulation des protéines 3BP2 mutantes à l'ori-gine du syndrome auto-inflamma-toire observé [6, 7].
-
une mutation heterozygote de SH3BP2 amplifie la reponse inflammatoire a l infection des macrophages dans un modele de cherubisme chez la souris
M S-medecine Sciences, 2015Co-Authors: Marcel Deckert, Virginie ProdhommeAbstract:Des mutations de SH3BP2 a l'origine du cherubisme Le cherubisme est une dysplasie cra-nio-faciale rare, caracterisee par un elargissement symetrique de la partie inferieure du visage qui donne au patient une apparence semblable a celle des cherubins de la Renaissance. Cette maladie genetique est transmise de maniere autosomique dominante. Les patients presentent une erosion importante des os de la mâchoire dans lesquels s'accumulent des kystes fibreux remplis de cel-lules multinucleees geantes de type osteoclaste. Les lesions apparaissent dans la petite enfance, entre 2 et 5 ans, et progressent jusqu'a la puberte pour regresser presque completement a l'âge adulte. Cette maladie reste benigne mais engendre des troubles importants de la face et de la denti-tion, associes a des problemes esthe-tiques et psychologiques qui neces-sitent une intervention chirurgicale dans les cas severes. La majorite des mutations associees au cherubisme affectent l'exon 9 du gene SH3BP2 codant pour 3BP2 ou SH3BP2 (Abl SH3 binding protein 2). Ces mutations conduisent au changement d'un unique acide amine dans la sequence R 415 SPPDG 420 de 3BP2 [1]. 3BP2 est une proteine adaptatrice que nous avions identifiee comme un partenaire de la proteine tyrosine kinase SYK [2] et d'autres molecules de signalisation comme les kinases SRC et les facteurs d'echange nucleotidique VAV. Ainsi, 3BP2 est impliquee dans l'activation de programmes transcriptionnels et cellulaires (comme le remodelage du reseau d'actine) via l'engagement de multiples recepteurs dans les reponses leucocytaires [3], la differenciation des osteoclastes [4] et le remodelage osseux [1]. L'etiologie du cherubisme est longtemps restee inconnue, mais le developpement de modeles chez la souris a permis d'importants pro-gres dans la comprehension des fac-teurs declencheurs de cette maladie enigmatique. Le knock-in des mutations P416R et G418R (respective-ment P418R et G420R chez l'homme) dans le gene SH3BP2 montre qu'un seul allele mutant n'est pas suffisant pour declencher la maladie chez la sou-ris. Les souris mutantes homozygotes developpent cependant une osteopo-rose severe et une inflammation sys-temique, avec des niveaux eleves de TNF- (tumor necrosis factor) serique, resultant d'une hyperactivation des voies de signalisation dependantes des kinases SRC et SYK et du facteur de transcription NFATc1 (nuclear factor of activated T-cells) dans les macro-phages et les osteoclastes. Ainsi, ces modeles definissent le cherubisme comme une maladie hereditaire auto-inflammatoire mediee par les cellules myeloides, et conferent a la mutation du gene SH3BP2 un role moteur dans cette maladie [5, 6]. Une avancee importante dans la comprehension du cherubisme est venue du laboratoire du Dr Rottapel, qui a identifie l'inter-action entre 3BP2 et la poly(ADP-ribosyl)polymerase tankyrase comme une etape cle dans la pathogenese de la maladie [7]. La fixation de tankyrase sur le motif RSPPDG de la proteine 3BP2 sauvage, en catalysant la poly(ADP-ribosyl)ation (PARyla-tion) de 3BP2, entraine sa polyubi-quitination par RNF146 (ring finger protein 146), une E3 ubiquitine ligase dependante de la PARylation des proteines. Cette sequence de modifications post-traductionnelles est suivie de la degradation de 3BP2 par le proteasome, assurant ainsi l'ho-meostasie proteique de 3BP2. Dans le cherubisme, ce mecanisme est defec-tueux car les mutations ponctuelles du motif RSPPDG de 3BP2 abolissent son interaction avec tankyrase, avec pour consequence une accumulation des proteines 3BP2 mutantes a l'ori-gine du syndrome auto-inflamma-toire observe [6, 7].
-
loss of tankyrase mediated destruction of 3bp2 is the underlying pathogenic mechanism of cherubism
Cell, 2011Co-Authors: Noam Levaot, Ioannis D. Dimitriou, Andrew Scotter, Salima Janmohamed, Marcel Deckert, Oleksandr Voytyuk, Fabrice Sircoulomb, Arun Chandrakumar, Paul M Krzyzanowski, Feng CongAbstract:SUMMARY Cherubism is an autosomal-dominant syndrome characterized by inflammatory destructive bony lesions resulting in symmetrical deformities of the facial bones. Cherubism is caused by mutations in SH3BP2, the gene that encodes the adaptor protein 3BP2. Most identified mutations in 3BP2 lie within the peptide sequence RSPPDG. A mouse model of cherubism develops hyperactive bone-remodeling osteoclasts and systemic inflammation characterized by expansion of the myelomonocytic lineage. The mechanism by which cherubism mutations alter 3BP2 function has remained obscure. Here we show that Tankyrase, a member of the poly(ADP-ribose) polymerase (PARP) family, regulates 3BP2 stability through ADP-ribosylation and subsequent ubiquitylation by the E3-ubiquitin ligase RNF146 in osteoclasts. Cherubism mutations uncouple 3BP2 from Tankyrase-mediated protein destruction, which results in its stabilization and subsequent hyperactivation of the SRC, SYK, and VAV signaling pathways.
-
L’adaptateur 3BP2 - Quelle place pour cette protéine dans la signalisation des leucocytes ?
Medecine sciences : M S, 2006Co-Authors: Marcel DeckertAbstract:Les proteines adaptatrices, bien que depourvues d’activite enzymatique intrinseque, jouent un role essentiel dans la biologie des cellules en regulant l’assemblage de complexes multimoleculaires de signalisation essentiels a la transmission intracellulaire des signaux extracellulaires recus par la cellule. Le nombre croissant de pathologies associees a des alterations de la fonction des proteines adaptatrices est une preuve supplementaire de l’importance de ces proteines dans la regulation cellulaire. L’adaptateur 3BP2 (ou SH3BP2) a ete initialement identifie en 1993 comme une proteine interagissant avec la proto-oncoproteine kinase c-Abl, puis en 1998 comme un partenaire des kinases de la famille Syk. 3BP2 montre une organisation en modules structuraux typique d’une molecule adaptatrice avec un domaine PH aminoterminal, une region centrale riche en proline et un domaine SH2 carboxyterminal. Si la fonction physiologique exacte de 3BP2 reste a ce jour inconnue, des etudes ont cependant montre un role de 3BP2 dans la signalisation par les immunorecepteurs (recepteurs de l’antigene des cellules T et B et recepteurs des immunoglobulines). Dans les leucocytes, 3BP2 s’associe avec un ensemble de molecules essentielles a la biologie de ces cellules, incluant les kinases Src et Syk, l’adaptateur transmembranaire LAT, les facteurs d’echange nucleotidique Vav, la phospholipase C-γ et les proteines 14-3-3. La decouverte en 2001 de mutations du gene 3bp2/SH3BP2 dans une maladie genetique rare du developpement craniofacial, appelee cherubisme, laisse entrevoir un role additionnel de 3BP2 dans la biologie des osteoclastes et, plus largement, des cellules hematopoietiques.
Tomoyuki Mukai - One of the best experts on this subject based on the ideXlab platform.
-
SH3BP2 Deficiency Ameliorates Murine Systemic Lupus Erythematosus
2020Co-Authors: Kyoko Kawahara, Tomoyuki Mukai, Yasuyoshi Ueki, Akiko Nagasu, Masanori Iseki, Hajime Nagasu, Takahiko Akagi, Shoko Tsuji, Sumie Hiramatsu-asano, Katsuhiko IshiharaAbstract:Abstract Background: The adaptor protein Src homology 3 domain-binding protein 2 (SH3BP2) is widely expressed in immune cells, such as myeloid cells, B cells, and T cells. It controls intracellular signaling pathways, including Syk and Src. The present study was undertaken to investigate the role of SH3BP2 in a murine systemic lupus erythematosus model.Methods: For the lupus model, we used Faslpr/lpr mice (C57BL/6 background). Clinical and immunological phenotypes were compared between Faslpr/lpr and SH3BP2-deficient Faslpr/lpr mice. Splenomegaly and renal involvement were assessed in 35-week-old mice. Serum levels of anti-dsDNA antibody and rheumatoid factor were determined using ELISA. Lymphocyte subsets in the spleen were analyzed by flow cytometry. To examine the role of SH3BP2 in specific cells, B cell-specific SH3BP2-deficient lupus mice were generated and analyzed; T cells and bone marrow-derived dendritic cells and macrophages were analyzed in vitro. Results: SH3BP2 deficiency significantly reduced lupus-like phenotypes, presented as splenomegaly, renal involvement, elevated serum anti-dsDNA antibody and rheumatoid factor, and increased splenic B220+CD4-CD8- T cells. Notably, SH3BP2 deficiency in B cells did not rescue the lupus-like phenotypes. Furthermore, SH3BP2 deficiency did not substantially affect the characteristics of T cells and macrophages in vitro. Interestingly, SH3BP2 deficiency suppressed the differentiation of dendritic cells in vitro and reduced the number of dendritic cells in the spleen of the lupus-prone mice.Conclusions: SH3BP2 deficiency ameliorated clinical and immunological manifestations in lupus-prone mice, possibly via targeting dendritic cell differentiation. Modulating SH3BP2 expression could thus provide a novel therapeutic approach to autoimmune diseases.
-
SH3BP2 Gain-Of-Function Mutation Ameliorates Lupus Phenotypes in B6.MRL-Faslpr Mice
Cells, 2019Co-Authors: Akiko Nagasu, Tomoyuki Mukai, Yasuyoshi Ueki, Kyoko Kawahara, Masanori Iseki, Hajime Nagasu, Shoko Tsuji, Katsuhiko Ishihara, Naoki Kashihara, Yoshitaka MoritaAbstract:SH3 domain-binding protein 2 (SH3BP2) is an adaptor protein that is predominantly expressed in immune cells, and it regulates intracellular signaling. We had previously reported that a gain-of-function mutation in SH3BP2 exacerbates inflammation and bone loss in murine arthritis models. Here, we explored the involvement of SH3BP2 in a lupus model. SH3BP2 gain-of-function (P416R knock-in; SH3BP2KI/+) mice and lupus-prone B6.MRL-Faslpr mice were crossed to yield double-mutant (SH3BP2KI/+Faslpr/lpr) mice. We monitored survival rates and proteinuria up to 48 weeks of age and assessed renal damage and serum anti-double-stranded DNA antibody levels. Additionally, we analyzed B and T cell subsets in lymphoid tissues by flow cytometry and determined the expression of apoptosis-related molecules in lymph nodes. SH3BP2 gain-of-function mutation alleviated the poor survival rate, proteinuria, and glomerulosclerosis and significantly reduced serum anti-dsDNA antibody levels in SH3BP2KI/+Faslpr/lpr mice. Additionally, B220+CD4−CD8− T cell population in lymph nodes was decreased in SH3BP2KI/+Faslpr/lpr mice, which is possibly associated with the observed increase in cleaved caspase-3 and tumor necrosis factor levels. SH3BP2 gain-of-function mutation ameliorated clinical and immunological phenotypes in lupus-prone mice. Our findings offer better insight into the unique immunopathological roles of SH3BP2 in autoimmune diseases.
-
Tankyrase (PARP5) Inhibition Induces Bone Loss through Accumulation of Its Substrate SH3BP2.
Cells, 2019Co-Authors: Tomoyuki Mukai, Shunichi Fujita, Yoshitaka MoritaAbstract:There is considerable interest in tankyrase because of its potential use in cancer therapy. Tankyrase catalyzes the ADP-ribosylation of a variety of target proteins and regulates various cellular processes. The anti-cancer effects of tankyrase inhibitors are mainly due to their suppression of Wnt signaling and inhibition of telomerase activity, which are mediated by AXIN and TRF1 stabilization, respectively. In this review, we describe the underappreciated effects of another substrate, SH3 domain-binding protein 2 (SH3BP2). Specifically, SH3BP2 is an adaptor protein that regulates intracellular signaling pathways. Additionally, in the human genetic disorder cherubism, the gain-of-function mutations in SH3BP2 enhance osteoclastogenesis. The pharmacological inhibition of tankyrase in mice induces bone loss through the accumulation of SH3BP2 and the subsequent increase in osteoclast formation. These findings reveal the novel functions of tankyrase influencing bone homeostasis, and imply that tankyrase inhibitor treatments in a clinical setting may be associated with adverse effects on bone mass.
-
Pharmacological inhibition of tankyrase induces bone loss in mice by increasing osteoclastogenesis.
Bone, 2018Co-Authors: Shunichi Fujita, Tomoyuki Mukai, Mizuho Kittaka, Yasuyoshi Ueki, Takafumi Mito, Shoko Kodama, Akiko Nagasu, Teruki Sone, Yoshitaka MoritaAbstract:Tankyrase is a poly (ADP-ribose) polymerase that leads to ubiquitination and degradation of target proteins. Since tankyrase inhibitors suppress the degradation of AXIN protein, a negative regulator of the canonical Wnt pathway, they effectively act as Wnt inhibitors. Small molecule tankyrase inhibitors are being investigated as drug candidates for cancer and fibrotic diseases, in which the Wnt pathways are aberrantly activated. Tankyrase is also reported to degrade the adaptor protein SH3BP2 (SH3 domain-binding protein 2). We have previously shown that SH3BP2 gain-of-function mutation enhances receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis in murine bone marrow-derived macrophages (BMMs). Although the interaction between tankyrase and SH3BP2 has been reported, it is not clear whether and how the inhibition of tankyrase affects bone cells and bone mass. Here, we have demonstrated that tankyrase inhibitors (IWR-1, XAV939, and G007-LK) enhanced RANKL-induced osteoclast formation and function in murine BMMs and human peripheral blood mononuclear cells through the accumulation of SH3BP2, subsequent phosphorylation of SYK, and nuclear translocation of NFATc1. Tankyrase inhibitors also enhanced osteoblast differentiation and maturation, represented by increased expression of osteoblast-associated genes accompanied by the accumulation of SH3BP2 protein and enhanced nuclear translocation of ABL, TAZ, and Runx2 in primary osteoblasts. Most importantly, pharmacological inhibition of tankyrase in mice significantly decreased tibia and lumbar vertebrae bone volumes in association with increased numbers of osteoclasts. Our findings uncover the role of tankyrase inhibition in bone cells and highlight the potential adverse effects of the inhibitor on bone.
-
Cherubism Mice Also Deficient in c-Fos Exhibit Inflammatory Bone Destruction Executed by Macrophages That Express MMP14 Despite the Absence of TRAP+ Osteoclasts.
Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research, 2017Co-Authors: Mizuho Kittaka, Tomoyuki Mukai, Teruhito Yoshitaka, Tetsuya Yoshimoto, Kotoe Mayahara, Jeffrey P. Gorski, Yasuyoshi UekiAbstract:Currently, it is believed that osteoclasts positive for tartrate-resistant acid phosphatase (TRAP+) are the exclusive bone-resorbing cells responsible for focal bone destruction in inflammatory arthritis. Recently, a mouse model of cherubism (SH3BP2KI/KI ) with a homozygous gain-of-function mutation in the SH3-domain binding protein 2 (SH3BP2) was shown to develop auto-inflammatory joint destruction. Here, we demonstrate that SH3BP2KI/KI mice also deficient in the FBJ osteosarcoma oncogene (c-Fos) still exhibit noticeable bone erosion at the distal tibia even in the absence of osteoclasts at 12 weeks old. Levels of serum collagen I C-terminal telopeptide (ICTP), a marker of bone resorption generated by matrix metalloproteinases (MMPs), were elevated, whereas levels of serum cross-linked C-telopeptide (CTX), another resorption marker produced by cathepsin K, were not increased. Collagenolytic MMP levels were increased in the inflamed joints of the SH3BP2KI/KI mice deficient in c-Fos. Resorption pits contained a large number of F4/80+ macrophages and genetic depletion of macrophages rescued these erosive changes. Importantly, administration of NSC405020, an MMP14 inhibitor targeted to the hemopexin (PEX) domain, suppressed bone erosion in c-Fos-deficient SH3BP2KI/KI mice. After activation of the NF-κB pathway, macrophage colony-stimulating factor (M-CSF)-dependent macrophages from c-Fos-deficient SH3BP2KI/KI mice expressed increased amounts of MMP14 compared with wild-type macrophages. Interestingly, receptor activator of NF-κB ligand (RANKL)-deficient SH3BP2KI/KI mice failed to show notable bone erosion, whereas c-Fos deletion did restore bone erosion to the RANKL-deficient SH3BP2KI/KI mice, suggesting that osteolytic transformation of macrophages requires both loss-of-function of c-Fos and gain-of-function of SH3BP2 in this model. These data provide the first genetic evidence that cells other than osteoclasts can cause focal bone destruction in inflammatory bone disease and suggest that MMP14 is a key mediator conferring pathological bone-resorbing capacity on c-Fos-deficient SH3BP2KI/KI macrophages. In summary, the paradigm that osteoclasts are the exclusive cells executing inflammatory bone destruction may need to be reevaluated based on our findings with c-Fos-deficient cherubism mice lacking osteoclasts. © 2017 American Society for Bone and Mineral Research.
Joan Sayós - One of the best experts on this subject based on the ideXlab platform.
-
silencing of adaptor protein SH3BP2 reduces kit pdgfra receptors expression and impairs gastrointestinal stromal tumors growth
Molecular Oncology, 2018Co-Authors: Eva Serranocandelas, Paulo Rodrigues, Sarah Bazzocco, Irati Macaya, Joaquín Arribas, César Serrano, Erola Ainsuaenrich, Arnau Navinesferrer, Alfonso Garciavalverde, Joan SayósAbstract:Gastrointestinal stromal tumors (GISTs) represent about 80% of the mesenchymal neoplasms of the gastrointestinal tract. Most GISTs contain oncogenic KIT (85%) or PDGFRA (5%) receptors. The kinase inhibitor imatinib mesylate is the preferential treatment for these tumors; however, the development of drug resistance has highlighted the need for novel therapeutic strategies. Recently, we reported that the adaptor molecule SH3 Binding Protein 2 (SH3BP2) regulates KIT expression and signaling in human mast cells. Our current study shows that SH3BP2 is expressed in primary tumors and cell lines from GIST patients and that SH3BP2 silencing leads to a downregulation of oncogenic KIT and PDGFRA expression and an increase in apoptosis in imatinib-sensitive and imatinib-resistant GIST cells. The microphthalmia-associated transcription factor (MITF), involved in KIT expression in mast cells and melanocytes, is expressed in GISTs. Interestingly, MITF is reduced after SH3BP2 silencing. Importantly, reconstitution of both SH3BP2 and MITF restores cell viability. Furthermore, SH3BP2 silencing significantly reduces cell migration and tumor growth of imatinib-sensitive and imatinib-resistant cells in vivo. Altogether, SH3BP2 regulates KIT and PDGFRA expression and cell viability, indicating a role as a potential target in imatinib-sensitive and imatinib-resistant GISTs.
-
Silencing of adaptor protein SH3BP2 reduces KIT/PDGFRA receptors expression and impairs gastrointestinal stromal tumors growth.
Molecular oncology, 2018Co-Authors: Eva Serrano-candelas, Erola Ainsua-enrich, Arnau Navinés-ferrer, Paulo Rodrigues, Alfonso García-valverde, Sarah Bazzocco, Irati Macaya, Joaquín Arribas, César Serrano, Joan SayósAbstract:Gastrointestinal stromal tumors (GISTs) represent about 80% of the mesenchymal neoplasms of the gastrointestinal tract. Most GISTs contain oncogenic KIT (85%) or PDGFRA (5%) receptors. The kinase inhibitor imatinib mesylate is the preferential treatment for these tumors; however, the development of drug resistance has highlighted the need for novel therapeutic strategies. Recently, we reported that the adaptor molecule SH3 Binding Protein 2 (SH3BP2) regulates KIT expression and signaling in human mast cells. Our current study shows that SH3BP2 is expressed in primary tumors and cell lines from GIST patients and that SH3BP2 silencing leads to a downregulation of oncogenic KIT and PDGFRA expression and an increase in apoptosis in imatinib-sensitive and imatinib-resistant GIST cells. The microphthalmia-associated transcription factor (MITF), involved in KIT expression in mast cells and melanocytes, is expressed in GISTs. Interestingly, MITF is reduced after SH3BP2 silencing. Importantly, reconstitution of both SH3BP2 and MITF restores cell viability. Furthermore, SH3BP2 silencing significantly reduces cell migration and tumor growth of imatinib-sensitive and imatinib-resistant cells in vivo. Altogether, SH3BP2 regulates KIT and PDGFRA expression and cell viability, indicating a role as a potential target in imatinib-sensitive and imatinib-resistant GISTs.
Steven A. Lietman - One of the best experts on this subject based on the ideXlab platform.
-
Cloning and characterization of the human SH3BP2 promoter
Biochemical and biophysical research communications, 2012Co-Authors: Chun Fan, Robert J. Gaivin, Michael A. Levine, Thomas A. Marth, Belinda Willard, Steven A. LietmanAbstract:SH3BP2 activating mutations lead to an unique clinical condition in which patients develop symmetrical bone resorptive lesions of the jaw, a condition termed cherubism. Due to this specific temporal sequence and location of bone resorption, we investigated the transcriptional regulation of SH3BP2 expression. Analyses of 5′- and 3′-serial promoter deletions defined the core promoter/regulatory elements, including two repressor sites (from −1,200 to −1,000 and from +86 to +115, respectively) and two activator sites (a PARP1 binding site from −44 to −21 and a second activator site from +57 to +86). We identified that PARP1 binds to DNA from −44 to −21 by Streptavidin–biotin purification and confirmed this binding by electrophoretic mobility shift assay (EMSA). Mutagenesis of the PARP1 binding site on the SH3BP2 promoter showed that this binding site is essential for SH3BP2 expression. EMSA and chromatin immunoprecipitation (ChIP) assays confirmed that PARP1 was able to bind to the SH3BP2 promoter in vitro and in vivo. Indeed, knockout of Parp1 in mice BMMs reduced expression of SH3BP2. These results demonstrate that PARP1 regulates expression of SH3BP2.
-
The role of SH3BP2 in the pathophysiology of cherubism
Orphanet Journal of Rare Diseases, 2012Co-Authors: Ernst J. Reichenberger, Michael A. Levine, Bjorn R Olsen, Maria E Papadaki, Steven A. LietmanAbstract:Cherubism is a rare bone dysplasia that is characterized by symmetrical bone resorption limited to the jaws. Bone lesions are filled with soft fibrous giant cell-rich tissue that can expand and cause severe facial deformity. The disorder typically begins in children at ages of 2-5 years and the bone resorption and facial swelling continues until puberty; in most cases the lesions regress spontaneously thereafter. Most patients with cherubism have germline mutations in the gene encoding SH3BP2, an adapter protein involved in adaptive and innate immune response signaling. A mouse model carrying a Pro416Arg mutation in SH3BP2 develops osteopenia and expansile lytic lesions in bone and some soft tissue organs. In this review we discuss the genetics of cherubism, the biological functions of SH3BP2 and the analysis of the mouse model. The data suggest that the underlying cause for cherubism is a systemic autoinflammatory response to physiologic challenges despite the localized appearance of bone resorption and fibrous expansion to the jaws in humans.
-
Decreased SH3BP2 inhibits osteoclast differentiation and function
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2011Co-Authors: Teruya Kawamoto, Chun Fan, Robert J. Gaivin, Michael A. Levine, Steven A. LietmanAbstract:Germline mutations in SH3BP2 gene have been identified in patients with cherubism, a skeletal disorder characterized by excessive osteoclastic bone resorption that is limited to the mandible and maxilla. We previously demonstrated that SH3BP2 overexpression in Raw264.7 cells increased RANKL-induced osteoclastogenesis. Here, we examine the effect of decreased SH3BP2 on osteoclastogenesis. shRNAknockdown of SH3BP2 decreased PLCγ2 phosphorylation and NFATc1 expression, and reduced the expression of osteoclast-specific genes. In BMMs knockdown of SH3BP2 led to reductions in both the number and the surface area of TRAP positive and multinucleated osteoclasts. Bone resorptive activity was also dramatically blocked by shRNAknockdown of SH3BP2. Similarly SH3BP2(−/−) deficient mice BMMs formed smaller osteoclasts that stained less with TRAP than wild-type mice. Taken together, this study demonstrates that SH3BP2 knockdown significantly decreases osteoclast differentiation and function. These results suggest that SH3BP2 plays a critical role in osteoclastogenesis and is a potential target for suppression of pathologic bone resorption.
-
SH3BP2 mutations potentiate osteoclastogenesis via PLCγ
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2010Co-Authors: Steven A. Lietman, Lihong Yin, Michael A. LevineAbstract:To determine the mechanism for the increased osteoclastogenesis in the jaw of cherubism patients with SH3BP2 mutations we evaluated the effect of mutant compared to wild-type SH3BP2 on activation of osteoclast signaling pathways. Indeed mutant forms of SH3BP2 do induce greater osteoclastogenesis. Heterozygous activating mutations in exon 9 of SH3BP2 have been found in most patients with cherubism, an unusual genetic syndrome characterized by excessive remodeling of the mandible and maxilla due to spontaneous and excessive osteoclastic bone resorption. Here we have investigated the functional consequences of SH3BP2 mutations on sRANKL-induced osteoclastogenesis in RAW 264.7 pre-osteoclast cells. sRANKL-stimulated RAW 264.7 cells were transfected with wild-type or mutant SH3BP2 plasmids. NFAT-luciferase and tartrate resistant acid phosphatase (TRAP), a marker of osteoclastic differentiation, levels were evaluated. Western immunoblots were also performed to determine phosphorylation of key proteins involved in the PI-PLC pathway leading to NFATc1 translocation. Our results indicate that forced expression of mutant forms of SH3BP2, found in cherubism patients, in RAW 264.7 cells induce greater NFAT activity and greater expression of TRAP than forced expression of wild-type SH3BP2. These findings indicate that missense SH3BP2 mutations cause a gain of protein function. Moreover, over expression of SH3BP2 in RAW 264.7 cells potentiates sRANKL-stimulated phosphorylation of PLCγ1 and PLCγ2. Our studies demonstrate that cherubism is due to gain-of-function mutations in SH3BP2 that stimulate RANKL-induced activation of PLCγ. The consequent activation of calcineurin and NFAT proteins induces the excessive osteoclastic phenotype of cherubism.
-
SH3BP2 is an activator of NFAT activity and osteoclastogenesis
Biochemical and biophysical research communications, 2008Co-Authors: Steven A. Lietman, Lihong Yin, Michael A. LevineAbstract:Heterozygous activating mutations in exon 9 of SH3BP2 have been found in most patients with cherubism, an unusual genetic syndrome characterized by excessive remodeling of the mandible and maxilla due to spontaneous and excessive osteoclastic bone resorption. Osteoclasts differentiate after binding of sRANKL to RANK induces a number of downstream signaling effects, including activation of the calcineurin/NFAT (nuclear factor of activated T cells) pathway. Here, we have investigated the functional significance of SH3BP2 protein on osteoclastogenesis in the presence of sRANKL. Our results indicate that SH3BP2 both increases nuclear NFATc1 in sRANKL treated RAW 264.7 preosteoclast cells and enhances expression of tartrate resistant acid phosphatase (TRAP), a specific marker of osteoclast differentiation. Moreover, overexpression of SH3BP2 in RAW 264.7 cells potentiates sRANKL-stimulated phosphorylation of PLCgamma1 and 2, thus providing a mechanistic pathway for the rapid translocation of NFATc1 into the nucleus and increased osteoclastogenesis in cherubism.
