scholarly journals An Fgfr3-activating mutation in immature osteoblasts affects the appendicular and craniofacial skeleton

2021 ◽  
pp. dmm.048272
Author(s):  
Martin Biosse Duplan ◽  
Emilie Dambroise ◽  
Valentin Estibals ◽  
Joelle Veziers ◽  
Jérome Guicheux ◽  
...  
Keyword(s):  
Bone Growth ◽  
Growth Factor Receptor ◽  
Long Bone ◽  
Mouse Strains ◽  
Adult Mice ◽  
Activating Mutation ◽  
Bone Anomalies ◽  
Bone Elongation ◽  
Old Mice

Achondroplasia (ACH), the most common form of dwarfism is caused by a missense mutation in the gene coding for fibroblast growth factor receptor 3 (FGFR3). The resulting increase in FGFR3 signaling perturbs the proliferation and differentiation of chondrocytes (CCs), alters the process of endochondral ossification and thus reduces bone elongation. Increased FGFR3 signaling in osteoblasts (OBs) might also contribute to bone anomalies in ACH. In the present study of a mouse model of ACH, we sought to determine whether or not FGFR3 overactivation in OBs leads to bone modifications. The model carries an Fgfr3 activating mutation (Fgfr3Y367C/+) that accurately mimics ACH; we targeted the mutation to either immature OBs and hypertrophic CCs or to mature OBs by using the Osx-cre and collagen 1α1 (2.3kb-Col1α1)-cre mouse strains, respectively. We observed that Fgfr3 activation in immature OBs and hypertrophic CCs (Osx-Fgfr3) not only perturbed the hypertrophic cells of the growth plate (thus affecting long bone growth) but also led to osteopenia and low cortical thickness in long bones in adult (3-month-old) mice but not in growing (3-week-old) mice. Importantly, craniofacial membranous bone defects were present in the adult mice. In contrast, activation of Fgfr3 in mature OBs (Col1-Fgfr3) had very limited effects on skeletal shape, size and micro-architecture. In vitro, we observed that Fgfr3 activation in immature OBs was associated with low mineralization activity. In conclusion, immature OBs appears to be affected by Fgfr3 overactivation, which might contribute to the bone modifications observed in ACH independently of CCs.

scholarly journals In vitro and in vivo characterization of Recifercept, a soluble fibroblast growth factor receptor 3, as treatment for achondroplasia

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244368
Author(s):  
Diogo Gonçalves ◽  
Guylène Rignol ◽  
Pierre Dellugat ◽  
Guido Hartmann ◽  
Stephanie Sarrazy Garcia ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Bone Growth ◽  
Fibroblast Growth Factor Receptor ◽  
Genetic Disorder ◽  
Growth Factor Receptor ◽  
Model Systems ◽  
Long Bone ◽  
Fibroblast Growth

Achondroplasia is a rare genetic disorder caused by mutations in the Fibroblast Growth Factor receptor 3 (FGFR3). These mutations lead to aberrant increase of inhibitory signaling in proliferating chondrocytes at the growth plate. Recifercept is a potential treatment for this disease using a decoy approach to sequester FGFR3 ligands subsequently normalizing activation of the mutated FGFR3 receptor. Recifercept binds to FGF isoforms in vitro and in cellular model systems and reduces FGFR3 signaling. In addition, in a transgenic mouse model of achondroplasia, Recifercept restores reduced body weight and long bone growth in these mice. These data suggest that Recifercept treatment could lead to clinical benefits in children treated with this molecule.

Longitudinal bone growth in vitro: effects of insulin-like growth factor I and growth hormone

1991 ◽  
Vol 124 (5) ◽  
pp. 602-607 ◽  
Author(s):  
Ben A. A. Scheven ◽  
Nicola J. Hamilton
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Bone Growth ◽  
Long Bone ◽  
Long Bones ◽  
Insulin Like Growth Factor ◽  
Serum Free ◽  
Factor I ◽  
Igf I

Abstract. Longitudinal growth was studied using an in vitro model system of intact rat long bones. Metatarsal bones from 18- and 19-day-old rat fetuses, entirely (18 days) or mainly (19 days) composed of chondrocytes, showed a steady rate of growth and radiolabelled thymidine incorporation for at least 7 days in serum-free media. Addition of recombinant human insulin-like growth factor-I to the culture media resulted in a direct stimulation of the longitudinal growth. Recombinant human growth hormone was also able to stimulate bone growth, although this was generally accomplished after a time lag of more than 2 days. A monoclonal antibody to IGF-I abolished both the IGF-I and GH-stimulated growth. However, the antibody had no effect on the growth of the bone explants in control, serum-free medium. Unlike the fetal long bones, bones from 2-day-old neonatal rats were arrested in their growth after 1-2 days in vitro. The neonatal bones responded to IGF-I and GH in a similar fashion as the fetal bones. Thus in this study in vitro evidence of a direct effect of GH on long bone growth via stimulating local production of IGF by the growth plate chondrocytes is presented. Furthermore, endogenous growth factors, others than IGFs, appear to play a crucial role in the regulation of fetal long bone growth.

scholarly journals Aging-Affected MSC Functions and Severity of Periodontal Tissue Destruction in a Ligature-Induced Mouse Periodontitis Model

2020 ◽  
Vol 21 (21) ◽  
pp. 8103
Author(s):  
Kyaw Thu Aung ◽  
Kentaro Akiyama ◽  
Masayoshi Kunitomo ◽  
Aung Ye Mun ◽  
Ikue Tosa ◽  
...  
Keyword(s):  
Growth Factor Receptor ◽  
Periodontal Tissue ◽  
Tissue Destruction ◽  
Aged Mice ◽  
T Cell Apoptosis ◽  
Severe Bone Loss ◽  
Fas L ◽  
Vitro Analysis ◽  
Old Mice

Mesenchymal stem cells (MSCs) are known to play important roles in the repair of lost or damaged tissues and immunotolerance. On the other hand, aging is known to impair MSC function. However, little is currently known about how aged MSCs affect the host response to the local inflammatory condition and tissue deterioration in periodontitis, which is a progressive destructive disease of the periodontal tissue potentially leading to multiple tooth loss. In this study, we examined the relationship between aging-induced impairment of MSC function and the severity of periodontal tissue destruction associated with the decrease in host immunomodulatory response using a ligature-induced periodontitis model in young and aged mice. The results of micro computerized tomography (micro-CT) and histological analysis revealed a more severe bone loss associated with increased osteoclast activity in aged (50-week-old) mice compared to young (5-week-old) mice. Immunostaining analysis revealed that, in aged mice, the accumulation of inflammatory T and B cells was higher, whereas the percentage of platelet-derived growth factor receptor α (PDGFRα)+ MSCs, which are known to modulate the apoptosis of T cells, was significantly lower than in young mice. In vitro analysis of MSC function showed that the expression of surface antigen markers for MSCs (Sca-1, CD90, CD146), colony formation, migration, and osteogenic differentiation of aged MSCs were significantly declined compared to those of young MSCs. Moreover, a significantly higher proportion of aged MSCs were positive for the senescence-associated β galactosidase activity. Importantly, aged MSCs presented a decreased expression of FAS-L, which was associated with a lower immunomodulatory property of aged MSCs to induce T cell apoptosis in co-cultures compared with young MSCs. In summary, this is the first study showing that aging-induced impairment of MSC function, including immunomodulatory response, is potentially correlated with progressive periodontal tissue deterioration.

scholarly journals Genetic neuroscience of mammalian learning and memory

2003 ◽  
Vol 358 (1432) ◽  
pp. 787-795 ◽  
Author(s):  
Susumu Tonegawa ◽  
Kazu Nakazawa ◽  
Matthew A. Wilson
Keyword(s):  
Cell Types ◽  
Genetically Engineered ◽  
Mouse Strains ◽  
Cellular Mechanisms ◽  
Genetic Manipulations ◽  
Adult Mice ◽  
Multiple Levels ◽  
Primary Research Interest

Our primary research interest is to understand the molecular and cellular mechanisms on neuronal circuitry underlying the acquisition, consolidation and retrieval of hippocampus-dependent memory in rodents. We study these problems by producing genetically engineered (i.e. spatially targeted and/or temporally restricted) mice and analysing these mice by multifaceted methods including molecular and cellular biology, in vitro and in vivo physiology and behavioural studies. We attempt to identify deficits at each of the multiple levels of complexity in specific brain areas or cell types and deduce those deficits that underlie specific learning or memory. We will review our recent studies on the acquisition, consolidation and recall of memories that have been conducted with mouse strains in which genetic manipulations were targeted to specific types of cells in the hippocampus or forebrain of young adult mice.

scholarly journals Isotypic and allotypic specificity of mouse rheumatoid factors.

1983 ◽  
Vol 157 (3) ◽  
pp. 1006-1019 ◽  
Author(s):  
J L Van Snick ◽  
V Stassin ◽  
B de Lestré
Keyword(s):  
Normal Mouse ◽  
Mouse Strains ◽  
Igg Subclass ◽  
Rheumatoid Factors ◽  
Spleen Cells ◽  
Polyclonal Activation ◽  
Old Mice ◽  
Reactive Antibody

The specificity of polyclonal mouse rheumatoid factors (RF) was analyzed by competition experiments with heat-aggregated mouse IgG subclasses. The RF spontaneously produced by three normal mouse strains (129/Sv, CBA/Ht, and C57Bl/6) and by two strains with autoimmune diseases (MRL/l and NZB) were found to consist of distinct non-cross-reactive antibody subpopulations each specific for one IgG subclass. The sera of the normal strains contained IgG1- and IgG2a-specific RF. The autoimmune strains produced an additional variety of RF that was specific for The autoimmune strains produced an additional variety of RF that was specific for IgG2b. Also, the RF secreted by spleen cells of various normal strains after in vitro polyclonal activation with lipopolysaccharide could be resolved into distinct subpopulations specific for IgG1 or IgG2a. These results were confirmed by the analysis of monoclonal RF derived from BALB/c, C57Bl/6, CBA/Ht, and 129/Sv mice: of 73 hybridomas with RF activity, 71 displayed a strict subclass specificity. The subclass predominantly recognized depended on the origin of the spleen cells used to generate the hybridomas. After polyclonal activation in vitro, a broad spectrum of different specificities was obtained with 16 RF specific for IgG1, 13 for IgG2a, and 4 for IgG2b. In contrast, 27 of 28 monoclonal RF derived from 129/Sv and BALB/c mice without prior polyclonal activation were specific for IgG2a, and of these 75% were allotype specific since they failed to react with IgG2a of the b allotype. These results demonstrate the importance of subclass specificity in the production of RF in vivo. With the exception of the IgG2b-specific clones, all these monoclonal RF reacted preferentially with heat-aggregated or antigen-bound IgG. Among the hybridomas generated by the fusion of in vitro polyclonally activated spleen cells of 4-wk-old mice, the frequency of clones with RF activity was at least 40 times higher than that of clones specific for mouse IgM, human IgG, ovalbumin, and hen lysozyme.

scholarly journals Incidence and severity of G6PI-induced arthritis are not increased in genetically distinct mouse strains upon aging

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Nico Andreas ◽  
Sylvia Müller ◽  
Nicole Templin ◽  
Paul M. Jordan ◽  
Harald Schuhwerk ◽  
...  
Keyword(s):  
Immune Cell ◽  
Ex Vivo ◽  
Wild Type Mouse ◽  
Mouse Strains ◽  
Functional Difference ◽  
Susceptible Mouse ◽  
Age Related ◽  
Th Cell ◽  
Old Mice

Abstract Background The incidence of rheumatoid arthritis is correlated with age. In this study, we analyzed the association of the incidence and severity of glucose-6-phosphate isomerase (G6PI)-induced arthritis with age in two different mouse strains. Methods Young and very old mice from two different arthritis-susceptible wild-type mouse strains were analyzed after a single subcutaneous injection of G6PI s.c. The metabolism and the function of synoviocytes were analyzed in vitro, the production of bioactive lipid mediators by myeloid cells and synoviocytes was assessed in vitro and ex vivo by UPLC-MS-MS, and flow cytometry was used to verify age-related changes of immune cell composition and function. Results While the severity of arthritis was independent from age, the onset was delayed in old mice. Old mice showed common signs of immune aging like thymic atrophy associated with decreased CD4+ effector T cell numbers. Despite its decrease, the effector T helper (Th) cell compartment in old mice was reactive and functionally intact, and their Tregs exhibited unaltered suppressive capacities. In homeostasis, macrophages and synoviocytes from old mice produced higher amounts of pro-inflammatory cyclooxygenase (COX)-derived products. However, this functional difference did not remain upon challenge in vitro nor upon arthritis reactions ex vivo. Conclusion While old mice show a higher baseline of inflammatory functions, this does not result in increased reaction towards self-antigens in arthritis-susceptible mouse strains. Together, our data from two different mouse strains show that the susceptibility for G6PI-induced arthritis is not age-dependent.

scholarly journals Theobroma cacao improves bone growth by modulating defective ciliogenesis in a mouse model of achondroplasia

2021 ◽  
Author(s):  
L. Martin ◽  
N. Kaci ◽  
C. Benoist-Lasselin ◽  
M. Mondoloni ◽  
S. Decaudaveine ◽  
...  
Keyword(s):  
Mouse Model ◽  
Primary Cilium ◽  
Theobroma Cacao ◽  
Primary Cilia ◽  
Bone Growth ◽  
Ex Vivo ◽  
Growth Factor Receptor ◽  
Drug Candidates ◽  
Bone Elongation

AbstractA gain-of-function mutation in the fibroblast growth factor receptor 3 gene (FGFR3) results in achondroplasia (ACH), the most frequent form of dwarfism. The constitutive activation of FGFR3 impaired bone formation and elongation and many signaling transduction pathways. Identification of new and relevant compounds targeting the FGFR3 signaling pathway is of broad importance for the treatment of ACH. Natural plant compounds are the prime sources of drug candidates. Here, we found that the phenol compound (-)-epicatechin isolated from Theobroma cacao effectively inhibits FGFR3’s downstream signaling pathways. Transcriptomic analysis in Fgfr3 mouse model showed that ciliary mRNA expression was modified and influenced significantly by the Indian hedgehog and PKA pathways. (-)-Epicatechin is able to rescue impairments in the expression of these mRNA that control both the structural organization of the primary cilium and ciliogenesis-related genes. In femurs isolated from a mouse model (Fgfr3Y367C/+) of ACH, we showed that (-)-epicatechin countered the bone growth impairment during 6 days of ex vivo cultures. We confirmed in vivo that daily subcutaneous injections of (-)-epicatechin in Fgfr3Y367C/+ mice increased bone elongation and rescued the primary cilium defect observed in chondrocytes. This modification of the primary cilia promoted the typical columnar arrangement of flat proliferative chondrocytes and thus enhanced bone elongation. The results of the present proof-of-principle study illustrated (-)-epicatechin’s ability may facilitate the development of (-)-epicatechin as a treatment for patients with ACH.

scholarly journals Palovarotene reduces heterotopic ossification in juvenile FOP mice but exhibits pronounced skeletal toxicity

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
John B Lees-Shepard ◽  
Sarah-Anne E Nicholas ◽  
Sean J Stoessel ◽  
Parvathi M Devarakonda ◽  
Michael J Schneider ◽  
...  
Keyword(s):  
Heterotopic Ossification ◽  
Bone Growth ◽  
Genetic Disorder ◽  
Activin A ◽  
Fibrodysplasia Ossificans Progressiva ◽  
Skeletal Maturation ◽  
Long Bone ◽  
Synovial Joint ◽  
Live Animal

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder characterized by debilitating heterotopic ossification (HO). The retinoic acid receptor gamma agonist, palovarotene, and antibody-mediated activin A blockade have entered human clinical trials, but how these therapeutic modalities affect the behavior of pathogenic fibro/adipogenic progenitors (FAPs) is unclear. Using live-animal luminescence imaging, we show that transplanted pathogenic FAPs undergo rapid initial expansion, with peak number strongly correlating with HO severity. Palovarotene significantly reduced expansion of pathogenic FAPs, but was less effective than activin A inhibition, which restored wild-type population growth dynamics to FAPs. Palovarotene pretreatment did not reduce FAPs’ skeletogenic potential, indicating that efficacy requires chronic administration. Although palovarotene inhibited chondrogenic differentiation in vitro and reduced HO in juvenile FOP mice, daily dosing resulted in aggressive synovial joint overgrowth and long bone growth plate ablation. These results highlight the challenge of inhibiting pathological bone formation prior to skeletal maturation.

scholarly journals Lactobacillus gasseri: effects on mouse intestinal flora enzyme activity and isoflavonoids in the caecum and plasma

2004 ◽  
Vol 92 (5) ◽  
pp. 771-776 ◽  
Author(s):  
Motoi Tamura ◽  
Mayumi Ohnishi-Kameyama ◽  
Kazuki Shinohara
Keyword(s):  
Saline Solution ◽  
Intestinal Flora ◽  
Physiological Saline ◽  
Faecal Flora ◽  
Lactobacillus Gasseri ◽  
Adult Mice ◽  
Significant Difference ◽  
Physiological Saline Solution ◽  
Old Mice

The effects of Lactobacillus gasseri JCM 1131T on isoflavonoid levels within the caecum and plasma were assessed in adult mice. Male 5-week-old mice were fed an AIN 93M diet for 30 d. Two groups of mice were administered either L. gasseri JCM 1131T (the LGI group) or physiological saline solution (the control (CI) group) daily for 5 d before dissection. The plasma daidzein concentration was significantly higher in the LGI group, however, their plasma equol concentration was significantly less than in the CI group. The total amount of equol present as aglycone in the caecum was significantly greater in the CI group, but there was no significant difference in the total daidzein present as caecal aglycone. In an in vitro incubation of daidzin with the faecal flora of mice, the equol concentration was significantly higher in the CI group. The numbers of lactobacilli present were significantly higher in the LGI group. The present data suggest that the administration of L. gasseri is likely to influence the effect of isoflavonoids on the host via changes in the gastrointestinal environment.

Toxicity and efficacy evaluation of multiple targeted polymalic acid conjugates for triple-negative breast cancer treatment

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Triple Negative ◽  
Growth Factor Receptor ◽  
Engineered Nanoparticles ◽  
Efficacy Evaluation ◽  
Dual Action ◽  
Epidermal Growth ◽  
Laminin 411 ◽  
Immunologic Analysis

Engineered nanoparticles are widely used for delivery of drugs but frequently lack proof of safetyfor cancer patient's treatment. All-in-one covalent nanodrugs of the third generation have beensynthesized based on a poly(β-L-malic acid) (PMLA) platform, targeting human triple-negativebreast cancer (TNBC). They significantly inhibited tumor growth in nude mice by blockingsynthesis of epidermal growth factor receptor, and α4 and β1 chains of laminin-411, the tumorvascular wall protein and angiogenesis marker. PMLA and nanodrug biocompatibility and toxicityat low and high dosages were evaluated in vitro and in vivo. The dual-action nanodrug and singleactionprecursor nanoconjugates were assessed under in vitro conditions and in vivo with multipletreatment regimens (6 and 12 treatments). The monitoring of TNBC treatment in vivo withdifferent drugs included blood hematologic and immunologic analysis after multiple intravenousadministrations. The present study demonstrates that the dual-action nanoconju-gate is highlyeffective in preclinical TNBC treatment without side effects, supported by hematologic andimmunologic assays data. PMLA-based nanodrugs of the Polycefin™ family passed multipletoxicity and efficacy tests in vitro and in vivo on preclinical level and may prove to be optimizedand efficacious for the treatment of cancer patients in the future.

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