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 Neuroinflammation in Aged Brain: Impact of the Oral Administration of Ellagic Acid Microdispersion

2020 ◽  
Vol 21 (10) ◽  
pp. 3631 ◽  
Author(s):  
Raffaella Boggia ◽  
Federica Turrini ◽  
Alessandra Roggeri ◽  
Guendalina Olivero ◽  
Francesca Cisani ◽  
...  
Keyword(s):  
Oral Administration ◽  
Ellagic Acid ◽  
Ex Vivo ◽  
Behavioral Skills ◽  
Aged Mice ◽  
Age Related ◽  
The Central Nervous System ◽  
The Impact ◽  
Old Mice

The immune system and the central nervous system message each other to preserving central homeostasis. Both systems undergo changes during aging that determine central age-related defects. Ellagic acid (EA) is a natural product which is beneficial in both peripheral and central diseases, including aging. We analyzed the impact of the oral administration of a new oral ellagic acid micro-dispersion (EAm), that largely increased the EA solubility, in young and old mice. Oral EAm did not modify animal weight and behavioral skills in young and old mice, but significantly recovered changes in “ex-vivo, in vitro” parameters in old animals. Cortical noradrenaline exocytosis decreased in aged mice. EAm administration did not modify noradrenaline overflow in young animals, but recovered it in old mice. Furthermore, GFAP staining was increased in the cortex of aged mice, while IBA-1 and CD45 immunopositivities were unchanged when compared to young ones. EAm treatment significantly reduced CD45 signal in both young and old cortical lysates; it diminished GFAP immunopositivity in young mice, but failed to affect IBA-1 expression in both young and old animals. Finally, EAm treatment significantly reduced IL1beta expression in old mice. These results suggest that EAm is beneficial to aging and represents a nutraceutical ingredient for elders.

scholarly journals Impaired immune response to Candida albicans in aged mice

2006 ◽  
Vol 55 (12) ◽  
pp. 1649-1656 ◽  
Author(s):  
Celia Murciano ◽  
Eva Villamón ◽  
Alberto Yáñez ◽  
José-Enrique O'Connor ◽  
Daniel Gozalbo ◽  
...  
Keyword(s):  
Immune Response ◽  
Candida Albicans ◽  
Fungal Infections ◽  
Acquired Resistance ◽  
Yeast Cells ◽  
T Helper 1 ◽  
Aged Mice ◽  
Old Mice ◽  
Young Mice

The prevalence of opportunistic fungal infections has increased dramatically among the aged population in recent years. This work investigated the effect of ageing on murine defences against Candida albicans. Aged C57BL/6 mice that were experimentally infected intravenously had a significantly impaired survival and a higher tissue fungal burden compared with young mice. In vitro production of tumour necrosis factor (TNF)-α by macrophages from aged mice in response to yeast cells and hyphae of C. albicans was significantly lower than production by macrophages from young mice. In vitro production of cytokines, such as TNF-α and gamma interferon (IFN-γ), by antigen-stimulated splenocytes from mice intravenously infected with C. albicans cells was also diminished in old mice. This decrease in production of T helper 1 cytokines in old mice correlated with a diminished frequency of IFN-γ-producing CD4+ T lymphocytes, although the ability to develop an acquired resistance upon vaccination (primary sublethal infection) of mice with the low-virulence PCA2 strain was not affected in aged mice. The diversity of antigens recognized by C. albicans-specific antibodies in sera from infected aged mice was clearly diminished when compared with that from infected young mice. Taken together, these data show that aged mice develop an altered innate and adaptive immune response to C. albicans and are more susceptible to systemic primary candidiasis.

scholarly journals HDAC6 inactivates Runx2 promoter to block osteogenesis of bone marrow stromal cells in age-related bone loss of mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chao Ma ◽  
Juan Gao ◽  
Jun Liang ◽  
Weixiang Dai ◽  
Zhenfei Wang ◽  
...  
Keyword(s):  
Bone Loss ◽  
Bone Formation ◽  
Osteogenic Differentiation ◽  
Differentiation Potential ◽  
Runx2 Expression ◽  
Aged Mice ◽  
Age Related ◽  
Old Mice

Abstract Background Senile osteoporosis can cause bone fragility and increased risk for fractures and has been one of the most prevalent and severe diseases affecting the elderly population worldwidely. The underlying mechanisms are currently intensive areas of investigation. In age-related bone loss, decreased bone formation overweighs increased bone resorption. The molecular mechanisms underlying defective bone formation in age-related bone loss are not completely understood. In particular, the specific role of histone acetylation in age-related bone loss has not been examined thoroughly. Methods We employed 6- and 18-month-old mice to investigate the mechanisms of defective bone formation in age-related bone loss. Bone marrow stromal cells (BMSCs) were induced to undergo in vitro osteogenic differentiation. Chromatin immunoprecipitation (ChIP) was used to investigate the binding of histone deacetylases (HDACs) on Runx2 promoter in BMSCs. Luciferase reporter and transient transfection assay were employed to study Runx2 gene expression modulation by HDAC and androgen receptor (AR). siRNA and HDAC6 inhibitor, Tubastatin A, were used to inhibit HDAC6 in vitro. And systemic administration of Tubastatin A was used to block HDAC6 in vivo. Results Age-related trabecular bone loss was observed in 18-month-old mice compared with 6-month-old mice. In vitro osteogenic differentiation potential of BMSCs from 18-month-old mice was weaker than 6-month-old mice, in which there was Runx2 expression inactivation in BMSCs of 18-month-old mice compared with 6-month-old mice, which was attributable to HDAC6-mediated histone hypoacetylation in Runx2 promoter. There was competitive binding of HDAC6 and AR on Runx2 promoter to modulate Runx2 expression in BMSCs. More importantly, through siRNA- or specific inhibitor-mediated HDAC6 inhibition, we could activate Runx2 expression, rescue in vitro osteogenesis potential of BMSCs, and alleviate in vivo age-related bone loss of mice. Conclusion HDAC6 accumulation and histone hypoacetylation on Runx2 promoter contributed to the attenuation of in vitro osteogenic differentiation potential of BMSCs from aged mice. Through HDAC6 inhibition, we could activate Runx2 expression and osteogenic differentiation potential of BMSCs from aged mice and alleviate the age-related bone loss of aged mice. Our study will benefit not only for understanding the age-related bone loss, but also for finding new therapies to treat senile osteoporosis.

scholarly journals Defucosylated Mouse–Dog Chimeric Anti-EGFR Antibody Exerts Antitumor Activities in Mouse Xenograft Models of Canine Tumors

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3599
Author(s):  
Guanjie Li ◽  
Tomokazu Ohishi ◽  
Mika K. Kaneko ◽  
Junko Takei ◽  
Takuya Mizuno ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Line ◽  
Growth Factor Receptor ◽  
High Sensitivity ◽  
Osteosarcoma Cell ◽  
Antibody Treatment ◽  
Antitumor Effects ◽  
Vitro Analysis

The epidermal growth factor receptor (EGFR) contributes to tumor malignancy via gene amplification and protein overexpression. Previously, we developed an anti-human EGFR (hEGFR) monoclonal antibody, namely EMab-134, which detects hEGFR and dog EGFR (dEGFR) with high sensitivity and specificity. In this study, we produced a defucosylated mouse–dog chimeric anti-EGFR monoclonal antibody, namely E134Bf. In vitro analysis revealed that E134Bf highly exerted antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity against a canine osteosarcoma cell line (D-17) and a canine fibroblastic cell line (A-72), both of which express endogenous dEGFR. Moreover, in vivo administration of E134Bf significantly suppressed the development of D-17 and A-72 compared with the control dog IgG in mouse xenografts. These results indicate that E134Bf exerts antitumor effects against dEGFR-expressing canine cancers and could be valuable as part of an antibody treatment regimen for dogs.

scholarly journals Functional Relationship Between T15 and J558 Idiotypes in BALB/c Mice

1991 ◽  
Vol 1 (3) ◽  
pp. 213-224 ◽  
Author(s):  
Meenal Vakil ◽  
John F. Kearney
Keyword(s):  
B Cells ◽  
Inbred Strains ◽  
Newborn Mice ◽  
Stage Of Development ◽  
Subsequent Response ◽  
Inbred Strains Of Mice ◽  
Vitro Analysis ◽  
A Minor ◽  
Old Mice

In inbred strains of mice, antiphosphorylcholine (PC) and anti-α1,3 dextran (DEX). antibodies are structurally distinct from each other and have been shown to exhibit noncrossreactive antigen binding and idiotypic specificities. However, the prototype anti-PC and anti-DEX antibodies, TEPC15 and J558, respectively, were shown to be connected via a common autoantiidiotypic monoclonal antibody isolated from newborn BALB/c mice. The capacity of various monoclonal anti-PC and anti-DEX antibodies as well as the antigens PC and DEX to modulate T15 and J558 idiotypes in BALB/c mice was tested by their administration to newborn mice. Anti-PC antibodies of the .T15 idiotype injected into 2-4-day-old mice, at a time when T15 anti-PC precursors develop in BALB/c mice, suppressed the anti- PC response of these mice at 6 weeks of age. Similarly, J558 antibodies injected into 8-12-day-old mice, at a time when J558 precursors normally develop, suppressed the response to DEX. As a further demonstration of this connectivity, the injection of J558 into 4-day-old mice led to a down modulation of T15 idiotype, whereas both T15 and a minor idiotypeexpressing antibody M167 when injected into 8-12-day-old mice caused a reduction in expression of the J558 idiotype. As predicted from in vitro analysis, injection of anti-PC antibodies of the M167 idiotype 2 to 4 days after birth enhanced the subsequent response to PC. However, anti-PC antibodies expressing another minor M603 idiotype did not affect the PC. response. The results parallel thein vitroenhancement of M167 antibodies but not M603 on T15 binding to antiidiotypein vitro. Similarly, anti-DEX antibodies expressing the M104E idiotype had no detectable effects on the capacity to respond to PC or DEX or on the expression of T15 and J558 idiotypes as adults. Exposure of newborn mice to PC led to a dramatic reduction in the response to DEX as adults, whereas exposure to DEX at this stage of development had no effect on response to PC as adults. Collectively, these observations provide evidence for a complex functional connectivity between T15 and J558 idiotype-bearing B cells during ontogeny and extend our previous observations that development of these idiotypes is regulated by idiotype-directed interactions between B cells or their immunoglobulin products.

IQGAP1 binds the Axl receptor kinase and inhibits its signaling

2018 ◽  
Vol 475 (19) ◽  
pp. 3073-3086
Author(s):  
Laëtitia Gorisse ◽  
Zhigang Li ◽  
Andrew C. Hedman ◽  
David B. Sacks
Keyword(s):  
Growth Factor ◽  
Intracellular Signaling ◽  
Growth Factor Receptor ◽  
Direct Interaction ◽  
Specific Protein ◽  
Tyrosine Kinase Receptor ◽  
Proximity Ligation ◽  
Vitro Analysis ◽  
In Cells

Axl is a tyrosine kinase receptor that is important for hematopoiesis, the innate immune response, platelet aggregation, engulfment of apoptotic cells and cell survival. Binding of growth arrest-specific protein 6 (Gas6) activates Axl signaling, but the mechanism of inactivation of the Axl receptor is poorly understood. In the present study, we show that IQGAP1 modulates Axl signaling. IQGAP1 is a scaffold protein that integrates cell signaling pathways by binding several growth factor receptors and intracellular signaling molecules. Our in vitro analysis revealed a direct interaction between the IQ domain of IQGAP1 and Axl. Analysis by both immunoprecipitation and proximity ligation assays demonstrated an association between Axl and IQGAP1 in cells and this interaction was decreased by Gas6. Unexpectedly, reducing IQGAP1 levels in cells significantly enhanced the ability of Gas6 to stimulate both Axl phosphorylation and activation of Akt. Moreover, IQGAP1 regulates the interaction of Axl with the epidermal growth factor receptor. Our data identify IQGAP1 as a previously undescribed suppressor of Axl and provide insight into regulation of Axl function.

Pan-cancer analysis of FGFR1-3 genomic alterations to reveal a complex molecular landscape.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3620-3620 ◽  
Author(s):  
Melanie A. Krook ◽  
Ian M. Silverman ◽  
Karthikeyan Murugesan ◽  
Gabrielle Ernst ◽  
Julie Reeser ◽  
...  
Keyword(s):  
Drug Sensitivity ◽  
Growth Factor Receptor ◽  
Kinase Domain ◽  
Clinical Activity ◽  
Missense Mutations ◽  
Genomic Alterations ◽  
Molecular Landscape ◽  
Vitro Analysis ◽  
Tumor Types

3620 Background: Activating genomic alterations (GAs) in the fibroblast growth factor receptor (FGFR) gene family occur in many tumor types. FGFR1-3 mutations and rearrangements are of particular interest given evidence of clinical activity of selective FGFR inhibitors in patients (pts) with susceptible alterations. We queried FGFR1-3 GAs in patient tumor samples analyzed using comprehensive genomic profiling (CGP) and performed in vitro characterization of select novel alterations. Methods: Tumor samples were assayed by hybrid capture based CGP on 0.8-1.2 Mb of the genome to identify GAs in exons and select introns in up to 404 genes (Foundation Medicine, Inc, Cambridge MA). Cell lines were stably transduced with alterations of interest and transformation assays and drug sensitivity assays were performed to determine oncogenic potential and sensitivity to FGFR inhibition by pemigatinib. Results: GAs in FGFR1-3 were present in 6314 of 274,694 pt specimens (2.3%), of which 4091 (64.8%) were short variants and 2269 (35.9%) were rearrangements. Tumor types with the highest frequency of FGFR1-3 alterations were bladder cancer (17.9%), cholangiocarcinoma (11.1%), endometrial cancer (7.9%), and glioma (5.5%) (Table). We identified 270 unique FGFR1-3 short-variants, including 144 missense mutations and 94 truncating alterations. Of short variants, the most frequent were FGFR3 p.S249C (18.3%), FGFR2 p.S252W (9.9%) and FGFR1 p.N546K (6.9%). Truncating alterations were largely identified in exon 18, downstream of the kinase domain. We identified 476 unique FGFR1-3 rearrangement pairs ( FGFR1; n=77, FGFR2; n=338, FGFR3; n=61). FGFR3-TACC3 was the most prevalent FGFR rearrangement (29.0%), followed by FGFR2-BICC1 and FGFR2-N/A (both 9.7%). In vitro analysis of the transforming potential and drug sensitivity for select alterations will be reported. Conclusions: FGFR1-3 mutations and rearrangements are highly diverse and present at low to moderate frequencies across many cancers. Therefore, cataloging and characterizing these diverse alterations has the potential to facilitate precision medicine. Tumor-specific and -agnostic trials of selective FGFR inhibitors in pts with susceptible alterations are ongoing. [Table: see text]

scholarly journals Intranasal delivery of mesenchymal stem cell secretome repairs the brain of Alzheimer’s mice

2020 ◽  
Vol 28 (1) ◽  
pp. 203-218 ◽  
Author(s):  
Giulia Santamaria ◽  
Edoardo Brandi ◽  
Pietro La Vitola ◽  
Federica Grandi ◽  
Giovanni Ferrara ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Treatment Protocol ◽  
Aged Mice ◽  
Memory Recovery ◽  
Amyloid Oligomers ◽  
Plaque Load ◽  
Direct Use ◽  
Old Mice

AbstractThe multiplicity of systems affected in Alzheimer’s disease (AD) brains calls for multi-target therapies. Although mesenchymal stem cells (MSC) are promising candidates, their clinical application is limited because of risks related to their direct implantation in the host. This could be overcome by exploiting their paracrine action. We herein demonstrate that in vivo systemic administration of secretome collected from MSC exposed in vitro to AD mouse brain homogenates (MSC-CS), fully replicates the cell-mediated neuroreparative effects in APP/PS1 AD mice. We found a complete but transient memory recovery by 7 days, which vanished by 14 days, after a single MSC-CS intravenous administration in 12-month or 22–24-month-old mice. Treatment significantly reduced plaque load, microglia activation, and expression of cytokines in astrocytes in younger, but not aged, mice at 7 days. To optimize efficacy, we established a sustained treatment protocol in aged mice through intranasal route. Once-weekly intranasal administration of MSC-CS induced persistent memory recovery, with dramatic reduction of plaques surrounded by a lower density of β-amyloid oligomers. Gliosis and the phagocytic marker CD68 were decreased. We found a higher neuronal density in cortex and hippocampus, associated with a reduction in hippocampal shrinkage and a longer lifespan indicating healthier conditions of MSC-CS-treated compared to vehicle-treated APP/PS1 mice. Our data prove that MSC-CS displays a great multi-level therapeutic potential, and lay the foundation for identifying the therapeutic secretome bioreactors leading to the development of an efficacious multi-reparative cocktail drug, towards abrogating the need for MSC implantation and risks related to their direct use.

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.

The native structure of the eukaryotic ribosome

1983 ◽  
Vol 41 ◽  
pp. 432-433
Author(s):  
R.A. Milligan ◽  
P.N.T. Unwin
Keyword(s):  
Ribosomal Proteins ◽  
Crystal Form ◽  
Native Structure ◽  
X Ray Diffraction ◽  
Eukaryotic Ribosome ◽  
Vitro Analysis ◽  
In Vitro Analysis ◽  
Resolution Structure ◽  
Stable Unit

A detailed understanding of the mechanism of protein synthesis will ultimately depend on knowledge of the native structure of the ribosome. Towards this end we have investigated the low resolution structure of the eukaryotic ribosome embedded in frozen buffer, making use of a system in which the ribosomes crystallize naturally.The ribosomes in the cells of early chicken embryos form crystalline arrays when the embryos are cooled at 4°C. We have developed methods to isolate the stable unit of these arrays, the ribosome tetramer, and have determined conditions for the growth of two-dimensional crystals in vitro, Analysis of the proteins in the crystals by 2-D gel electrophoresis demonstrates the presence of all ribosomal proteins normally found in polysomes. There are in addition, four proteins which may facilitate crystallization. The crystals are built from two oppositely facing P4 layers and the predominant crystal form, accounting for >80% of the crystals, has the tetragonal space group P4212, X-ray diffraction of crystal pellets demonstrates that crystalline order extends to ~ 60Å.

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