scholarly journals Synthetic Hydroxyapatite Inhibits Bisphosphonate Toxicity to the Oral Mucosa In Vitro

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2086 ◽  
Author(s):  
George Bullock ◽  
Cheryl Miller ◽  
Alasdair McKechnie ◽  
Vanessa Hearnden
Keyword(s):  
Oral Mucosa ◽  
Metabolic Activity ◽  
Calcium Binding ◽  
Soft Tissues ◽  
Pamidronic Acid ◽  
Dependent Manner ◽  
Porous Hydroxyapatite ◽  
Socket Preservation ◽  
Oral Cells

Medication-related osteonecrosis of the jaw (MRONJ) is a side effect of bisphosphonate therapy, characterised by exposed necrotic bone. The soft tissues of the oral mucosa no longer provide a protective barrier and MRONJ patients experience pain, infections and difficulties eating. We hypothesised that hydroxyapatite (Ca5(PO4)3(OH)) could reduce bisphosphonate concentrations and protect the oral mucosa by exploiting bisphosphonate’s calcium binding affinity. The effect of zoledronic acid (ZA) and pamidronic acid (PA) on the metabolism of oral fibroblasts, oral keratinocytes and three-dimensional oral mucosa models was investigated and then repeated in the presence of hydroxyapatite granules. Without hydroxyapatite, ZA and PA significantly reduced the metabolic activity of oral cells in a dose-dependent manner. Both drugs reduced epithelial thickness and 30 µM ZA resulted in loss of the epithelium. Hydroxyapatite granules had a protective effect on oral cells, with metabolic activity retained. Oral mucosa models retained their multi-layered epithelium when treated with ZA in the presence of hydroxyapatite granules and metabolic activity was comparable to controls. These results demonstrate hydroxyapatite granules protected oral soft tissues from damage caused by bisphosphonate exposure. Porous hydroxyapatite granules are currently used for socket preservation and this data suggests their potential to prevent MRONJ in at-risk patients.

scholarly journals In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

2011 ◽  
Vol 56 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marisa H. Miceli ◽  
Stella M. Bernardo ◽  
T. S. Neil Ku ◽  
Carla Walraven ◽  
Samuel A. Lee
Keyword(s):  
Candida Albicans ◽  
Metabolic Activity ◽  
Biofilm Formation ◽  
High Dose ◽  
Dependent Manner ◽  
Planktonic Cells ◽  
Content Type ◽  
Heparin Sodium ◽  
The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

scholarly journals PD-1 dependent expansion of Amphregulin+FOXP3+ cells is associated with oral immune dysfunction in HIV patients on therapy

2021 ◽  
Author(s):  
N Bhaskaran ◽  
E Schneider ◽  
F Faddoul ◽  
A Paes da Silva ◽  
R Asaad ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Oral Mucosa ◽  
Immune Dysfunction ◽  
People Living With Hiv ◽  
Dependent Manner ◽  
Mucosal Tissues ◽  
T Cell Regulation ◽  
Ifn Γ

AbstractResidual systemic inflammation and mucosal immune dysfunction persist in people living with HIV (PLWH) despite treatment with combined anti-retroviral therapy (cART), but the underlying immune mechanisms are poorly understood. Here we report an altered immune landscape involving upregulation of TLR- and inflammasome signaling, localized CD4+ T cell hyperactivation, and counterintuitively, an enrichment of CD4+CD25+FOXP3+ regulatory T cells (Tregs) in the oral mucosa of HIV+ patients on therapy. Using human oral tonsil cultures, we found that HIV infection causes an increase in a unique population of FOXP3+ cells expressing PD-1, IFN-γ, Amphiregulin (AREG), and IL-10. These cells persisted even in the presence of the anti-retroviral drug and underwent further expansion driven by TLR-2 ligands and IL-1β. IL-1β also promoted PD-1 upregulation in AKT1 dependent manner. PD-1 stabilized FOXP3 and AREG expression in these cells through a mechanism requiring the activation of Asparaginyl Endopeptidase (AEP). Importantly, these FOXP3+ cells were incapable of suppressing CD4+ T cells in vitro. Concurrently, HIV+ patients harbored higher levels of PD-1, IFN-γ, Amphiregulin (AREG), and IL-10 expressing FOXP3+ cells, which strongly correlated with CD4+ T cell hyperactivation, suggesting an absence of CD4+ T cell regulation in the oral mucosa. Taken together, this study provides insights into a novel mechanism of FOXP3+ cell dysregulation and reveals a critical link in the positive feedback loop of oral mucosal immune activation events in HIV+ patients on therapy.One Sentence SummaryHIV-induced immune dysfunction in lymphoid and mucosal tissues

scholarly journals Profilaggrin is a major epidermal calcium-binding protein.

1993 ◽  
Vol 13 (1) ◽  
pp. 613-625 ◽  
Author(s):  
N G Markova ◽  
L N Marekov ◽  
C C Chipev ◽  
S Q Gan ◽  
W W Idler ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Expression Patterns ◽  
Epidermal Cells ◽  
Epidermal Differentiation ◽  
Amino Terminus ◽  
Calcium Signal ◽  
Dependent Manner ◽  
Structural Protein ◽  
Rnase Protection

Profilaggrin is a major highly phosphorylated protein component of the keratohyalin granules of mammalian epidermis. It contains 10 to 12 tandemly repeated filaggrin units and is processed into the intermediate filament-associated protein filaggrin by specific dephosphorylation and proteolysis during terminal differentiation of the epidermal cells. Later, filaggrin itself is degraded to free amino acids that participate in maintenance of epidermal flexibility. The present paper describes the structural organization of the 5' region of the human profilaggrin gene as well as the amino terminus of the profilaggrin protein. The primary profilaggrin transcript consists of three exons and two introns. The first exon (exon I) is only 54 bp and is untranslated. The coding sequences are distributed between exon II (159 bp) and exon III, which contains the information for 10 to 12 filaggrin repeats (972 bp each) and the 3' noncoding sequences. A very large intron separates exons I and II. The combination of a very short exon I with an unusually long intron 1 makes the structure of the profilaggrin gene unique among the epidermally expressed genes investigated so far. Comparison of the expression patterns revealed by primer extension and RNase protection analysis of foreskin epidermal and cultured keratinocyte RNAs suggests that alternately spliced messages, which are different from profilaggrin mRNA, are transcribed from the profilaggrin gene system at earlier stages of epidermal differentiation. The amino terminus of profilaggrin exhibits a significant homology to the small calcium-binding S100-like proteins. It contains two alpha-helical regions, termed EF-hands, that bind calcium in vitro. This is the first example of functional calcium-binding domains fused to a structural protein. We suggest that in addition to its role in filament aggregation and the maintenance of epidermal flexibility, profilaggrin may play an important role in the differentiation of the epidermis by autoregulating its own processing in a calcium-dependent manner or by participating in the transduction of calcium signal in epidermal cells.

scholarly journals Calprotectin and the Initiation and Progression of Head and Neck Cancer

2018 ◽  
Vol 97 (6) ◽  
pp. 674-682 ◽  
Author(s):  
P.P. Argyris ◽  
Z.M. Slama ◽  
K.F. Ross ◽  
A. Khammanivong ◽  
M.C. Herzberg
Keyword(s):  
Head And Neck ◽  
Calcium Binding ◽  
Gene Networks ◽  
Tumor Formation ◽  
Carcinoma Cells ◽  
Epidermal Differentiation ◽  
Matrix Metalloproteinase 2 ◽  
Dependent Manner ◽  
Cellular Development

Calprotectin (S100A8/A9), a heterodimeric complex of calcium-binding proteins S100A8 and S100A9, is encoded by genes mapping to the chromosomal locus 1q21.3 of the epidermal differentiation complex. Whereas extracellular calprotectin shows proinflammatory and antimicrobial properties by signaling through RAGE and TLR4, intracytoplasmic S100A8/A9 appears to be important for cellular development, maintenance, and survival. S100A8/A9 is constitutively expressed in myeloid cells and the stratified mucosal epithelia lining the oropharyngeal and genitourinary mucosae. While upregulated in adenocarcinomas and other cancers, calprotectin mRNA and protein levels decline in head and neck squamous cell carcinoma (HNSCC). S100A8/A9 is also lost during head and neck preneoplasia (dysplasia). Calprotectin decrease does not correlate with the clinical stage (TNM) of HNSCC. When expressed in carcinoma cells, S100A8/A9 downregulates matrix metalloproteinase 2 expression and inhibits invasion and migration in vitro. S100A8/A9 regulates cell cycle progression and decelerates cancer cell proliferation by arresting at the G2/M checkpoint in a protein phosphatase 2α–dependent manner. In HNSCC, S100A8 and S100A9 coregulate with gene networks controlling cellular development and differentiation, cell-to-cell signaling, and cell morphology, while S100A8/A9 appears to downregulate expression of invasion- and tumorigenesis-associated genes. Indeed, tumor formation capacity is attenuated in S100A8/A9-expressing carcinoma cells in vivo. Hence, intracellular calprotectin appears to function as a tumor suppressor in head and neck carcinogenesis. When compared with S100A8/A9-low HNSCC based on analysis of TCGA, S100A8/A9-high HNSCC shows significant upregulation of apoptosis-related genes, including multiple caspases. Accordingly, S100A8/A9 facilitates DNA damage responses in HNSCC, promotes apoptotic cell death, and confers sensitivity to cisplatin and X-radiation in vitro. In the tumor milieu, loss of S100A8/A9 strongly associates with poor squamous differentiation and higher tumor grading, EGFR upregulation, increased DNA methylation, and, finally, poorer overall survival for patients with HNSCC. Hence, intracellular calprotectin shows a multifaceted protective role against the development of HNSCC.

scholarly journals The Long Noncoding RNA Hotair Regulates Oxidative Stress and Cardiac Myocyte Apoptosis during Ischemia-Reperfusion Injury

2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Kai Meng ◽  
Jiao Jiao ◽  
Rui-Rui Zhu ◽  
Bo-Yuan Wang ◽  
Xiao-Bo Mao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Calcium Binding ◽  
Cardiac Myocyte ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Myocyte Apoptosis ◽  
Cardiac Myocyte Apoptosis

Oxidative stress and subsequent cardiac myocyte apoptosis play central roles in the initiation and progression of myocardial ischemia-reperfusion (I/R) injury. Homeobox transcript antisense intergenic RNA (Hotair) was previously implicated in various heart diseases, yet its role in myocardial I/R injury has not been clearly demonstrated. Mice with cardiac-restricted knockdown or overexpression of Hotair were exposed to I/R surgery. H9c2 cells were cultured and subjected to hypoxia/reoxygenation (H/R) stimulation to further verify the role and underlying mechanisms of Hotair in vitro. Histological examination, molecular detection, and functional parameters were determined in vivo and in vitro. In response to I/R or H/R treatment, Hotair expression was increased in a bromodomain-containing protein 4-dependent manner. Cardiac-restricted knockdown of Hotair exacerbated, whereas Hotair overexpression prevented I/R-induced oxidative stress, cardiac myocyte apoptosis, and cardiac dysfunction. Mechanistically, we observed that Hotair exerted its beneficial effects via activating AMP-activated protein kinase alpha (AMPKα). Further detection revealed that Hotair activated AMPKα through regulating the enhancer of zeste homolog 2/microRNA-451/calcium-binding protein 39 (EZH2/miR-451/Cab39) axis. We provide the evidence that endogenous lncRNA Hotair is an essential negative regulator for oxidative stress and cardiac myocyte apoptosis in myocardial I/R injury, which is dependent on AMPKα activation via the EZH2/miR-451/Cab39 axis.

scholarly journals Short term supplementation of celecoxib shifted butyrate production on a simulated model of the gut microbial ecosystem and ameliorated in vitro inflammation

2019 ◽  
Author(s):  
Emma Hernandez-Sanabria ◽  
Evelien Heiremans ◽  
Marta Calatayud Arroyo ◽  
Ruben Props ◽  
Laurent Leclercq ◽  
...  
Keyword(s):  
Community Composition ◽  
Metabolic Activity ◽  
Bacterial Community Composition ◽  
Dependent Manner ◽  
Short Term ◽  
Acetyl Coa ◽  
Host Interactions ◽  
Cox 2 ◽  
Butyrate Production

ABSTRACTCelecoxib has been demonstrated effective in the prevention and treatment of chronic inflammatory disorders through inhibition of altered cyclooxygenase-2 (COX-2) pathways. Despite the benefits for preventing colorectal cancer (CRC), continuous administration may increase risk of cardiovascular events. Understanding microbiome-drug-host interactions is fundamental for improving drug disposition and safety responses of colon-targeted formulations, but little information is available on the bidirectional interaction between individual microbiomes and celecoxib. Here we conducted in vitro batch incubations of faecal microbiota to evaluate the short-term impact of celecoxib on activity and composition of colon bacterial communities. Celecoxib-exposed microbiota shifted metabolic activity and community composition, whereas total transcriptionally active bacterial population was not significantly changed. Butyrate production decreased by 50% in a donor-dependent manner, suggesting that celecoxib impacts in vitro fermentation. Microbiota-derived acetate has been associated with inhibition of cancer markers and our results suggest uptake of acetate for bacterial functions when celecoxib was supplied, which potentially favoured bacterial competition for acetyl-CoA. We further assessed whether colon microbiota modulates anti-inflammatory efficacy of celecoxib using both a simplified inflammation model, and a novel in vitro simulation of the enterohepatic metabolism. Celecoxib was responsible for only 5% of the variance in bacterial community composition but celecoxib-exposed microbiota preserved barrier function and decreased concentrations of IL-8 and CXCL16 in a donor-dependent manner in our two cell models simulating inflammatory milieu in the gut. Our results suggest that celecoxib-microbiome-host interactions may not only elicit adaptations in community composition but also in microbiota functionality and may need to be considered for guaranteeing efficient COX-2 inhibition.IMPORTANCEAs inter-individual changes in the microbiome composition and functionality may be a confounder on pharmacotherapy, we obtained mechanistic understanding on how short-term celecoxib exposure impacts the functional activities of colon communities. Celecoxib-exposed microbiota shifted metabolic activity without impacting numbers of total active bacteria, but only community composition. Thus, increased relative abundance of particular genera during celecoxib supplementation may just indicate changes in maintenance energy. Focus on the influence of acetyl-CoA on cancer cells and verifying whether changes in acetate:propionate:butyrate ratios rather than in taxonomic diversity can be used as markers of decreased inflammation may be the next frontiers for predicting successful NSAID therapy, and ultimately for developing microbiome-based therapies.

scholarly journals Influence of Nano, Micro and Macro Topography of Dental Implant Surfaces on Human Gingival Fibroblasts

2021 ◽  
Vol 22 (18) ◽  
pp. 9871
Author(s):  
Morena Petrini ◽  
Tania Vanessa Pierfelice ◽  
Emira D’Amico ◽  
Natalia Di Pietro ◽  
Assunta Pandolfi ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Titanium Implant ◽  
Sem Analysis ◽  
Human Gingival Fibroblasts ◽  
Dependent Manner ◽  
Gingival Fibroblasts ◽  
Force Microscopy ◽  
Atomic Force

Current research on dental implants has mainly focused on the influence of surface roughness on the rate of osseointegration, while studies on the development of surfaces to also improve the interaction of peri-implant soft tissues are lacking. To this end, the first purpose of this study was to evaluate the response of human gingival fibroblasts (hGDFs) to titanium implant discs (Implacil De Bortoli, Brazil) having different micro and nano-topography: machined (Ti-M) versus sandblasted/double-etched (Ti-S). The secondary aim was to investigate the effect of the macrogeometry of the discs on cells: linear-like (Ti-L) versus wave-like (Ti-W) surfaces. The atomic force microscopy (AFM) and scanning electron microscopy (SEM) analysis showed that the Ti-S surfaces were characterized by a significantly higher micro and nano roughness and showed the 3D macrotopography of Ti-L and Ti-W surfaces. For in vitro analyses, the hGDFs were seeded into titanium discs and analyzed at 1, 3, and 5 days for adhesion and morphology (SEM) viability and proliferation (Cck-8 and MTT assays). The results showed that all tested surfaces were not cytotoxic for the hGDFs, rather the nano-micro and macro topography favored their proliferation in a time-dependent manner. Especially, at 3 and 5 days, the number of cells on Ti-L was higher than on other surfaces, including Ti-W surfaces. In conclusion, although further studies are needed, our in vitro data proved that the use of implant discs with Ti-S surfaces promotes the adhesion and proliferation of gingival fibroblasts, suggesting their use for in vivo applications.

scholarly journals Copper Acyl Salicylate Has Potential as an Anti-CryptococcusAntifungal Agent

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Adepemi O. Ogundeji ◽  
Boitumelo F. Porotloane ◽  
Carolina H. Pohl ◽  
Pravin S. Kendrekar ◽  
Olihile M. Sebolai
Keyword(s):  
Antifungal Activity ◽  
Metal Complex ◽  
Growth Inhibition ◽  
Metabolic Activity ◽  
Immune Cells ◽  
Dependent Manner ◽  
Content Type ◽  
Therapeutic Outcomes ◽  
Dose Dependent

ABSTRACTThein vitroantifungal activity of aspirin against cryptococcal cells has been reported. However, the unwanted effects of aspirin may limit its clinical application. Conceivably, a derivative of aspirin could overcome this challenge. Toward this end, this study considered the usage of an aspirinate-metal complex, namely, copper acyl salicylate (CAS), as an anti-Cryptococcusantifungal agent. Additionally, the study examined the effects of this compound on macrophage function. Thein vitrosusceptibility results revealed that cryptococcal cells were vulnerable (in a dose-dependent manner) to CAS, which might have effected growth inhibition by damaging cryptococcal cell membranes. Interestingly, when CAS was used in combination with fluconazole or amphotericin B, synergism was observed. Furthermore, CAS did not negatively affect the growth or metabolic activity of macrophages; rather, it sensitized those immune cells to produce interferon gamma and interleukin 6, which, in turn, might have aided in the phagocytosis of cryptococcal cells. Compared to our aspirin data, CAS was noted to be more effective in killing cryptococcal cells (based on susceptibility results) and less toxic toward macrophages (based on growth inhibition results). Taking these findings together, it is reasonable to conclude that CAS may be a better anti-Cryptococcusdrug that could deliver better therapeutic outcomes, compared to aspirin.

scholarly journals Flagellar Radial Spoke Protein 2 Is a Calmodulin Binding Protein Required for Motility in Chlamydomonas reinhardtii

2004 ◽  
Vol 3 (1) ◽  
pp. 72-81 ◽  
Author(s):  
Pinfen Yang ◽  
Chun Yang ◽  
Winfield S. Sale
Keyword(s):  
Calcium Binding ◽  
Regulatory Subunit ◽  
Dependent Manner ◽  
Radial Spoke ◽  
Calcium Dependent ◽  
Calmodulin Binding ◽  
Morphological Studies ◽  
Radial Spokes

ABSTRACT Genetic and morphological studies have revealed that the radial spokes regulate ciliary and flagellar bending. Functional and biochemical analysis and the discovery of calmodulin in the radial spokes suggest that the regulatory mechanism involves control of axonemal protein phosphorylation and calcium binding to spoke proteins. To identify potential regulatory proteins in the radial spoke, in-gel kinase assays were performed on isolated axonemes and radial spoke fractions. The results indicated that radial spoke protein 2 (RSP2) can bind ATP and transfer phosphate in vitro. RSP2 was cloned and mapped to the PF24 locus, a gene required for motility. Sequencing revealed that pf24 contains a point mutation converting the first ATG to ATA, resulting in only trace amounts of RSP2 and confirming the RSP2 mapping. Surprisingly, the sequence does not include signature domains for conventional kinases, indicating that RSP2 may not perform as a protein kinase in vivo. However, the predicted RSP2 protein sequence contains Ca2+-dependent calmodulin binding motifs and a GAF domain, a domain found in diverse signaling proteins for binding small ligands including cyclic nucleotides. As predicted from the sequence, recombinant RSP2 binds calmodulin in a calcium-dependent manner. We postulate that RSP2 is a regulatory subunit of the radial spoke involved in localization of calmodulin for control of motility.

Profilaggrin is a major epidermal calcium-binding protein

1993 ◽  
Vol 13 (1) ◽  
pp. 613-625
Author(s):  
N G Markova ◽  
L N Marekov ◽  
C C Chipev ◽  
S Q Gan ◽  
W W Idler ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Expression Patterns ◽  
Epidermal Cells ◽  
Epidermal Differentiation ◽  
Amino Terminus ◽  
Calcium Signal ◽  
Dependent Manner ◽  
Structural Protein ◽  
Rnase Protection

Profilaggrin is a major highly phosphorylated protein component of the keratohyalin granules of mammalian epidermis. It contains 10 to 12 tandemly repeated filaggrin units and is processed into the intermediate filament-associated protein filaggrin by specific dephosphorylation and proteolysis during terminal differentiation of the epidermal cells. Later, filaggrin itself is degraded to free amino acids that participate in maintenance of epidermal flexibility. The present paper describes the structural organization of the 5' region of the human profilaggrin gene as well as the amino terminus of the profilaggrin protein. The primary profilaggrin transcript consists of three exons and two introns. The first exon (exon I) is only 54 bp and is untranslated. The coding sequences are distributed between exon II (159 bp) and exon III, which contains the information for 10 to 12 filaggrin repeats (972 bp each) and the 3' noncoding sequences. A very large intron separates exons I and II. The combination of a very short exon I with an unusually long intron 1 makes the structure of the profilaggrin gene unique among the epidermally expressed genes investigated so far. Comparison of the expression patterns revealed by primer extension and RNase protection analysis of foreskin epidermal and cultured keratinocyte RNAs suggests that alternately spliced messages, which are different from profilaggrin mRNA, are transcribed from the profilaggrin gene system at earlier stages of epidermal differentiation. The amino terminus of profilaggrin exhibits a significant homology to the small calcium-binding S100-like proteins. It contains two alpha-helical regions, termed EF-hands, that bind calcium in vitro. This is the first example of functional calcium-binding domains fused to a structural protein. We suggest that in addition to its role in filament aggregation and the maintenance of epidermal flexibility, profilaggrin may play an important role in the differentiation of the epidermis by autoregulating its own processing in a calcium-dependent manner or by participating in the transduction of calcium signal in epidermal cells.

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