25 results on '"Leitão RFC"'
Search Results
2. Selective inhibition of interleukin 6 receptor decreased inflammatory cytokines and increased proteases in an experimental model of critical calvarial defect.
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Melo RCO, Martins AA, Vieira GHA, Andrade RVS, Silva DNA, Chalmers J, Silveira TM, Pirih FQ, Araújo VS, Silva JSP, Lopes MLDS, Leitão RFC, Araújo Júnior RF, Silva ILG, Silva LJT, Barbosa EG, and Araújo AA
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- Animals, Male, Rats, Antibodies, Monoclonal, Humanized pharmacology, Antibodies, Monoclonal, Humanized therapeutic use, X-Ray Microtomography, Peptide Hydrolases metabolism, Immunohistochemistry, Random Allocation, Rats, Wistar, Cytokines metabolism, Receptors, Interleukin-6 antagonists & inhibitors, Disease Models, Animal, Skull drug effects
- Abstract
Considering the lack of consensus related to the impact of selective IL-6 receptor inhibition on bone remodeling and the scarcity of reports, especially on large bone defects, this study proposed to evaluate the biological impact of the selective inhibitor of interleukin-6 receptor (tocilizumab) in an experimental model of critical calvarial defect in rats. In this preclinical and in vivo study, 24 male Wistar rats were randomly divided into two groups (n=12/group): defect treated with collagen sponge (CG) and defect treated with collagen sponge associated with 2 mg/kg tocilizumab (TCZ). The defect in the parietal bone was created using an 8-mm diameter trephine drill. After 90 days, the animals were euthanized, and tissue samples (skull caps) were evaluated through micro-CT, histological, immunohistochemistry, cytokines, and RT-qPCR analyses. Tocilizumab reduced mononuclear inflammatory infiltration (P<0.05) and tumor necrosis factor (TNF)-α levels (P<0.01) and down-regulated tissue gene expression of BMP-2 (P<0.001), RUNX-2 (P<0.05), and interleukin (IL)-6 (P<0.05). Moreover, it promoted a stronger immunostaining of cathepsin and RANKL (P<0.05). Micro-CT and histological analyses revealed no impact on general bone formation (P>0.05). The bone cells (osteoblasts, osteoclasts, and osteocytes) in the defect area were similar in both groups (P>0.05). Tocilizumab reduced inflammatory cytokines, decreased osteogenic protein, and increased proteases in a critical bone defect in rats. Ninety days after the local application of tocilizumab in the cranial defect, we did not find a significant formation of bone tissue compared with a collagen sponge.
- Published
- 2024
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3. Molecular epidemiology and antimicrobial resistance in Clostridioides difficile strains isolated from children and adolescents in a tertiary referral pediatric hospital in Fortaleza, Brazil.
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Nogueira HBR, Costa CL, Quesada-Gómez C, Pacífico DM, Ferreira EO, Leitão RFC, and Brito GAC
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- Humans, Child, Adolescent, Female, Male, Brazil epidemiology, Cross-Sectional Studies, Prospective Studies, Child, Preschool, Risk Factors, Infant, Molecular Epidemiology, Diarrhea microbiology, Diarrhea epidemiology, Ribotyping, Drug Resistance, Bacterial genetics, Clostridioides difficile genetics, Clostridioides difficile drug effects, Clostridioides difficile isolation & purification, Tertiary Care Centers statistics & numerical data, Anti-Bacterial Agents pharmacology, Clostridium Infections epidemiology, Clostridium Infections microbiology, Microbial Sensitivity Tests, Hospitals, Pediatric
- Abstract
Background: C. difficile has been increasingly reported as a cause of gastrointestinal disease in children, ranging from mild self-limiting diarrhea to severe conditions such as pseudomembranous colitis and toxic megacolon. Only two pediatric research groups reported the presence of C. difficile infection in Brazilian children, but no previous research has examined C. difficile infection among children in northeastern Brazil. This prospective cross-sectional study investigated the molecular epidemiology and antimicrobial resistance of C. difficile strains isolated from children and adolescents with diarrhea referred to a tertiary pediatric hospital in Brazil while exploring the associated risk factors., Results: Toxin positivity or C. difficile isolation was found in 30.4 % (17/56) samples. C. difficile was isolated from 35 % (6/17) samples. Four toxigenic strains were identified (tpi+, tcdA+, tcdB+, cdtB-, without tcdC deletions) belonging to PCR ribotypes and PFGE-pulsotypes: 046 (new pulsotype 1174), 106 (NAP11), 002 (new pulsotype 1274), 012 (new pulsotype NML-1235). Two of the six isolates belonging to ribotypes 143 and 133 were non-toxigenic. All toxigenic strains were sensitive to metronidazole and vancomycin. Regarding the clinical manifestation, diarrhea lasted an average of 11 days, ranging from 3 to 50 days and was often associated with mucus and/or blood. All six patients from whom the C. difficile was isolated had a chronic disease diagnosis, with these comorbidities as the main risk factors., Conclusion: Our study enhances our understanding of the present epidemiological landscape of C. difficile-associated diarrhea (CDI) among children in northeastern Brazil, reveling a substantial CDI frequency of 30.4 %, with toxigenic strains detected in 76.4 % of cases, highlighting a higher prevalence compared to earlier Brazilian studies. In the globalized world, an understanding of disease-generating strains, the associated risk factors, clinical manifestation, and antimicrobial sensitivity has fundamental epidemiological importance and draws attention to preventive measures, allowing for more decisive action., Competing Interests: Conflicts of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Sociedade Brasileira de Infectologia. Published by Elsevier España, S.L.U. All rights reserved.)
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- 2024
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4. Mu and Kappa opioid receptor immunolabeling indicates the prognosis of oropharyngeal squamous cell carcinoma: A cross-sectional observational study.
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Dantas TS, Silva PGB, de Oliveira Filho OV, Magalhães IA, Alves APNN, Cunha MDPSS, Mota MRL, Leitão RFC, and Sousa FB
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- Humans, Squamous Cell Carcinoma of Head and Neck, Receptors, Opioid, kappa metabolism, Caspase 3, Retrospective Studies, Ki-67 Antigen metabolism, Cross-Sectional Studies, Prognosis, Carcinoma, Squamous Cell diagnosis, Oropharyngeal Neoplasms diagnosis, Head and Neck Neoplasms
- Abstract
Background: Opioids are the most effective drugs currently available for cancer pain management. The administration of morphine, in addition to its analgesic effect, can alter tumor development., Objective: To characterize the immunoexpression of opioid receptors µ and κ in oropharyngeal squamous cell carcinoma, and correlate it with prognostic factors, proliferation markers, and cell death., Materials and Methods: A retrospective, cross-sectional observational study was carried out with 50 patients diagnosed at Haroldo Juaçaba Hospital. Sociodemographic, clinicopathological, and overall survival data were collected, and excisional biopsies were taken for immunohistochemistry using tissue microarrays for opioid receptors µ and κ, Ki-67, and caspase-3. Immunolabeling was evaluated and correlated with other variables using Mann-Whitney, Kruskal-Wallis, Spearman correlation, log-rank (Mantel-Cox), and Cox regression tests., Results: Immunoexpression of opioid receptors µ and κ, Ki-67, and caspase-3 was significantly higher in p16+ and p16- primary tumors and lymph node metastases than in surgical resection margins. The overall survival of patients with p16- tumors was 57.53 ± 8.43 months and that of patients with p16+ tumors was slightly higher at 75.92 ± 11.14 months. Multivariate analysis showed that the expression of opioid receptors µ and κ in the nucleus was directly associated with a lower and higher risk of death, respectively., Conclusion: We found increased expression of opioid receptors µ and κ in tumor tissues. The nuclear expression of opioid receptors µ and κ influences overall survival and may be a prognostic factor of oropharyngeal squamous cell carcinoma., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)
- Published
- 2023
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5. Agaricus blazei Murill polysaccharides/alginate/poly(vinyl alcohol) blend as dressings for wound healing.
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Saraiva MM, Campelo MDS, Câmara Neto JF, Gonzaga MLDC, Bastos MDSR, Soares SA, Ricardo NMPS, Cerqueira GS, Leitão RFC, and Ribeiro MENP
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- Humans, Polysaccharides pharmacology, Wound Healing, Bandages, Polymers, Polyvinyl Alcohol chemistry, Alginates chemistry
- Abstract
Macromolecules with antioxidant properties such as polysaccharides from Agaricus blazei Murill mushroom (PAbs) are an excellent option for manufacturing wound dressings. Based on this, this study aimed to analyze preparation, physicochemical characterization, and assessment of the potential wound-healing activity of films based on sodium alginate and polyvinyl alcohol loaded with PAbs. PAbs did not significantly alter the cell viability of human neutrophils in a concentration range of 1-100 μg mL
-1 . The Infrared Spectroscopy (FTIR) indicates that the components present in the films (PAbs/Sodium Alginate (SA)/Polyvinyl Alcohol (PVA)) present an increase in hydrogen bonds due to the increase of hydroxyls present in the components. Thermogravimetry (TGA), Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD) characterizations indicate a good miscibility between the components where PAbs increasing the amorphous characteristics of the films and that the addition of SA increased the mobility of the chains PVA polymers. The addition of PAbs to films significantly improves properties such as mechanical, thickness, and water vapor permeation. The morphological study evidenced good miscibility between the polymers. The wound healing evaluation indicated that F100 film presented better results from the fourth day onward compared to the other groups. It favored the formation of a thicker dermis (476.8 ± 18.99 μm), with greater collagen deposition and a significant reduction in malondialdehyde and nitrite/nitrate, markers of oxidative stress. These results indicate that PAbs is a candidate for wound dressing., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)- Published
- 2023
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6. Comparative biofilm-forming ability between Clostridioides difficile strains isolated in Latin America and the epidemic NAP1/027 strain.
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Morais MLGDS, Santos MGC, Costa CL, Martins CS, Leitão RFC, de Melo Pacífico D, Quesada-Gómez C, Castelo Branco D, Ferreira EO, and Brito GAC
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- Humans, Bacterial Proteins genetics, Bacterial Proteins metabolism, Biofilms, Latin America, Multilocus Sequence Typing, Vancomycin pharmacology, Bacterial Toxins metabolism, Clostridioides difficile genetics, Clostridioides difficile metabolism, Clostridium Infections microbiology
- Abstract
Introduction: One of the challenges in treating Clostridioides difficile infection (CDI) is that the bacterium forms biofilms, a critical virulence mechanism known to promote antibiotic resistance and, as a result, consequently, a higher recurrence of the disease. The goal of this study was to compare the ability of three MLST Clade 2 strains to form a biofilm in vitro: ICC-45 (ribotype SLO231/UK[CE]821), a ST41 toxinotype IXb isolated in Brazil; and two epidemic NAP1/027/ST01 strains: NAP1/027/ST01 (LIBA5756), isolated during a 2010 outbreak in Costa Rica and the reference epidemic strain NAP1/027/ST01 (R20291); and ATCC700057, a non-toxigenic strain., Methods: The ability of strains to form biofilm was evaluated using crystal violet staining. In addition, samples were stained with the Film Tracer biofilm matrix (Invitrogen®) and the biofilm matrix thickness was measured using confocal microscopy. The matrix architecture was determined using Scanning electron microscop. Confocal microscopy was used to detect the presence of toxin A (tcdA) using an anti- Clostridioides difficile TcdA antibody. The expression of virulence genes ( tcdA , tcdB , tcdC , cdtB , spo0A , slpA , cwp66 and cwp84 ) was examined, as well as the effect of antibiotics metronidazole (MTZ) and vancomycin (VAN) on biofilm growth., Results: All of the strains tested formed a moderate biofilm with 1.1
570nm >3.5. After 72h, biofilm biomass of the NAP1/027/ST01 epidemic strains (LIBA5756 and R20291) was significantly higher than ICC-45 and ATCC 700057 biofilms, as confirmed by electron and confocal microscopy. At 120h, the LIBA5756 biofilm biomass decreased compared to other strains. The toxigenic strains R20291 or LIBA 5756 had higher expression of genes tcdA , tcdB , tcdC , cdtA , slpA and spo0A than ICC-45, but there were no significant differences in the expression levels of cdtB , cwp66 and cwp84 . In epidemic strains, VAN and MTZ inhibited biofilm formation; however, in the ICC-45 strain, MIC concentrations of VAN and MIC and 4MIC of MTZ did not inhibit biofilm formation., Conclusion: The three MLST Clade 2 isolated from different rybotipes, two of which were isolated from Latin America, are competent biofilm-forming bacteria, indicating their ability to induce C. difficile infection recurrence, making treatment difficult., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Morais, Santos, Costa, Martins, Leitão, de Melo Pacífico, Quesada-Gómez, Castelo Branco, Ferreira and Brito.) - Published
- 2022
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7. Role of Pannexin-1-P2X7R signaling on cell death and pro-inflammatory mediator expression induced by Clostridioides difficile toxins in enteric glia.
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Loureiro AV, Moura-Neto LI, Martins CS, Silva PIM, Lopes MBS, Leitão RFC, Coelho-Aguiar JM, Moura-Neto V, Warren CA, Costa DVS, and Brito GAC
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- Animals, Annexins, Caspase 3 metabolism, Cell Death, Inflammation Mediators, Male, Mice, Mice, Inbred C57BL, Neuroglia metabolism, Phosphatidylserines, Bacterial Toxins metabolism, Clostridioides difficile, Connexins genetics, Connexins metabolism, Nerve Tissue Proteins genetics, Nerve Tissue Proteins metabolism, Receptors, Purinergic P2X7 genetics
- Abstract
Clostridioides difficile ( C. difficile) produces toxins A (TcdA) and B (TcdB), both associated with intestinal damage and diarrhea. Pannexin-1 (Panx1) channels allows the passage of messenger molecules, such as adenosine triphosphate (ATP), which in turn activate the P2X7 receptors (P2X7R) that regulate inflammation and cell death in inflammatory bowel diseases. The aim of this study was to verify the effect of C. difficile infection (CDI) in the expression of Panx1 and P2X7R in intestinal tissues of mice, as well as their role in cell death and IL-6 expression induced by TcdA and TcdB in enteric glial cells (EGCs). Male C57BL/6 mice (8 weeks of age) were infected with C. difficile VPI10463, and the control group received only vehicle per gavage. After three days post-infection (p.i.), cecum and colon samples were collected to evaluate the expression of Panx1 by immunohistochemistry. In vitro , EGCs (PK060399egfr) were challenged with TcdA or TcdB, in the presence or absence of the Panx1 inhibitor (10Panx trifluoroacetate) or P2X7R antagonist (A438079), and Panx1 and P2X7R expression, caspase-3/7 activity and phosphatidylserine binding to annexin-V, as well as IL-6 expression were assessed. CDI increased the levels of Panx1 in cecum and colon of mice compared to the control group. Panx1 inhibitor decreased caspase-3/7 activity and phosphatidylserine-annexin-V binding, but not IL-6 gene expression in TcdA and TcdB-challenged EGCs. P2X7 receptor antagonist accentually reduced caspase-3/7 activity, phosphatidylserine-annexin-V binding, and IL-6 gene expression in TcdA and TcdB-challenged EGCs. In conclusion, Panx1 is increased during CDI and plays an important role in the effects of C. difficile toxins in EGCs, participating in cell death induced by both toxins by promoting caspase-3/7 activation via P2X7R, which is also involved in IL-6 expression induced by both toxins., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Loureiro, Moura-Neto, Martins, Silva, Lopes, Leitão, Coelho-Aguiar, Moura-Neto, Warren, Costa and Brito.)
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- 2022
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8. Host and Clostridioides difficile-Response Modulated by Micronutrients and Glutamine: An Overview.
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Loureiro AV, Barbosa MLL, Morais MLGS, Souza IP, Terceiro LS, Martins CS, Sousa APR, Leitão RFC, Shin JH, Warren CA, Costa DVS, and Brito GAC
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Changes in intestinal microbiota are integral to development of Clostridioides difficile ( C. difficile )-associated nosocomial diarrhea. Certain diets, especially Western diets, increase susceptibility to C. difficile infection (CDI). Here, we discuss recent findings regarding how nutrients modulate response of the host and C. difficile during infection. Calcium has a role in the sporulation and germination process. Selenium is effective in reducing the total amount of C. difficile toxin A (TcdA) and toxin B (TcdB) and in decreasing its cytotoxicity. In addition, selenium phosphate synthetase deficiency reduces C. difficile growth and spore production. On the other hand, iron has a dual role in C. difficile growth. For instance, high intracellular levels can generate reactive hydroxyl radicals, whereas low levels can reduce its growth. In humans, zinc deficiency appears to be related to the recurrence of CDI, in contrast, in the CDI model in mice a diet rich in zinc increased the toxin's activity. Low vitamin D levels contribute to C. difficile colonization, toxin production, and inflammation. Furthermore, glutamine appears to protect intestinal epithelial cells from the deleterious effects of TcdA and TcdB. In conclusion, nutrients play an important role in modulating host and pathogen response. However, further studies are needed to better understand the mechanisms and address some controversies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Loureiro, Barbosa, Morais, Souza, Terceiro, Martins, Sousa, Leitão, Shin, Warren, Costa and Brito.)
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- 2022
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9. Successful Pre-Clinical Management of Irinotecan-Debilitated Animals: A Protein- Based Accessory Phytomedicine.
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Rangel GFP, Ramos MV, do Carmo LD, Rabelo LMA, Silva AAV, de Sousa TFG, Lima Júnior RCP, Wong DVT, Leitão RFC, Magalhães PJC, Sousa BF, Frederico MJS, and Alencar NMN
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- Animals, Cyclooxygenase 2, Interleukin-10, Interleukin-6, Iodoacetamide, Irinotecan pharmacology, Latex chemistry, Latex pharmacology, NF-kappa B, Plant Proteins pharmacology, Plant Proteins therapeutic use, Calotropis chemistry, Cysteine Proteases
- Abstract
Background: Calotropis procera is a laticiferous plant (Apocynaceae) found in tropical regions all over the world. The ultrastructural characteristics of laticifers, their restricted distribution among different taxonomic groups, and in some species in each clade, as peptidases from latex, make them very attractive for biological analysis., Objective: The study aims to investigate the effects of LP-PII-IAA (laticifer protein (LP) sub-fraction II (PII) of C. procera presenting an iodoacetamide-inhibited cysteine proteinase activity) on irinotecan-induced intestinal mucositis, a serious adverse effect of this medicine for the treatment of cancer., Methods: LP-PII-IAA is composed of closely related isoforms (90%) of peptidases derived from catalysis and an osmotin protein (5%). Animals receiving co-administration of LP-PII-IAA presented a significant decrease in mortality, absence of diarrhea, histological preservation, and normalization of intestinal functions., Results: Clinical homeostasis was accompanied by a reduction in MPO activity and declined levels of IL-1β, IL-6 and KC, while the IL-10 level increased in LP-PII-IAA-treated animals. COX-2 and NF-kB immunostaining was reduced and the levels of oxidative markers (GSH, MDA) were normalized in animals that received LP-PII-IAA., Conclusion: We suggest that peptidases from the latex of Calotropis procera were instrumental in the suppression of the adverse clinical and physiological effects of irinotecan., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
- Published
- 2022
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10. The Receptor AT1 Appears to Be Important for the Maintenance of Bone Mass and AT2 Receptor Function in Periodontal Bone Loss Appears to Be Regulated by AT1 Receptor.
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Lima MLS, Martins AA, Medeiros CACX, Guerra GCB, Santos R, Bader M, Pirih FQ, Araújo Júnior RF, Brito GAC, Leitão RFC, Silva RA, Barbosa SJA, Melo RCO, and Araújo AA
- Subjects
- Alveolar Bone Loss genetics, Alveolar Bone Loss pathology, Angiotensin II metabolism, Animals, Disease Models, Animal, Male, Mandibular Diseases genetics, Mandibular Diseases pathology, Mice, Mice, Knockout, Periodontitis genetics, Periodontitis pathology, Receptor, Angiotensin, Type 1 genetics, Receptor, Angiotensin, Type 2 genetics, Alveolar Bone Loss metabolism, Mandibular Diseases metabolism, Periodontitis metabolism, Receptor, Angiotensin, Type 1 metabolism, Receptor, Angiotensin, Type 2 metabolism
- Abstract
A large number of experimental studies has demonstrated that angiotensin II (Ang II) is involved in key events of the inflammatory process. This study aimed to evaluate the role of Ang II type 1 (AT1) and Ang II type 2 (AT2) receptors on periodontitis. Methods: Experimental periodontitis was induced by placing a 5.0 nylon thread ligature around the second upper left molar of AT1 mice, no-ligature or ligature (AT1-NL and AT1-L), AT2 (AT2-NL or AT2-L) and wild type (WT-NL or L). Alveolar bone loss was scanned using Micro-CT. Cytokines, peptides and enzymes were analyzed from gingival tissues by Elisa and RT-PCR. Results: The blockade of AT1 receptor resulted in bone loss, even in healthy animals. Ang II receptor blockades did not prevent linear bone loss. Ang II and Ang 1-7 levels were significantly increased in the AT2-L ( p < 0.01) group compared to AT2-NL and AT1-L. The genic expression of the Mas receptor was significantly increased in WT-L and AT2-L compared to (WT-NL and AT2-NL, respectively) and in AT1-L. Conclusions: Our data suggest that the receptor AT1 appears to be important for the maintenance of bone mass. AT2 receptor molecular function in periodontitis appears to be regulated by AT1.
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- 2021
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11. AT1 and AT2 Receptor Knockout Changed Osteonectin and Bone Density in Mice in Periodontal Inflammation Experimental Model.
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Lima MLS, Medeiros CACX, Guerra GCB, Santos R, Bader M, Pirih FQ, Araújo Júnior RF, Chan AB, Cruz LJ, Brito GAC, Leitão RFC, Silveira EJDD, Garcia VB, Martins AA, and Araújo AA
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- Animals, Disease Models, Animal, Lipopolysaccharides toxicity, Male, Mice, Knockout, Nitric Oxide Synthase Type II genetics, Periodontitis chemically induced, Periodontitis diagnostic imaging, Periodontitis pathology, Porphyromonas gingivalis pathogenicity, RANK Ligand metabolism, X-Ray Microtomography, Mice, Bone Density genetics, Periodontitis genetics, Receptor, Angiotensin, Type 1 genetics, Receptor, Angiotensin, Type 2 genetics
- Abstract
Background: The aim of this study was to evaluate the role of AT1 and AT2 receptors in a periodontal inflammation experimental model., Methods: Periodontal inflammation was induced by LPS/ Porphyromonas gingivalis . Maxillae, femur, and vertebra were scanned using Micro-CT. Maxillae were analyzed histopathologically, immunohistochemically, and by RT-PCR., Results: The vertebra showed decreased BMD in AT1 H compared with WT H ( p < 0.05). The femur showed increased Tb.Sp for AT1 H and AT2 H, p < 0.01 and p < 0.05, respectively. The Tb.N was decreased in the vertebra (WT H-AT1 H: p < 0.05; WT H-AT2 H: p < 0.05) and in the femur (WT H-AT1 H: p < 0.01; WT H-AT2 H: p < 0.05). AT1 PD increased linear bone loss ( p < 0.05) and decreased osteoblast cells ( p < 0.05). RANKL immunostaining was intense for AT1 PD and WT PD ( p < 0.001). OPG was intense in the WT H, WT PD, and AT2 PD when compared to AT1 PD ( p < 0.001). AT1 PD showed weak immunostaining for osteocalcin compared with WT H, WT PD, and AT2 PD ( p < 0.001). AT1 H showed significantly stronger immunostaining for osteonectin in fibroblasts compared to AT2 H ( p < 0.01)., Conclusion: AT1 receptor knockout changed bone density, the quality and number of bone trabeculae, decreased the number of osteoblast cells, and increased osteonectin in fibroblasts.
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- 2021
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12. Analysis of the Immunoexpression of Opioid Receptors and their Correlation with Markers of Angiogenesis, Cell Proliferation and Apoptosis in Breast Cancer.
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De Sousa AM, Dantas TS, Barros Silva PG, Martins CDS, Freire GE, Junior HLR, Brito GAC, Pereira KMA, and Leitão RFC
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- Apoptosis, Breast Neoplasms pathology, Cell Proliferation, Cross-Sectional Studies, Female, Humans, Ki-67 Antigen metabolism, Middle Aged, Neoplasm Staging, Retrospective Studies, Vascular Endothelial Growth Factor A metabolism, Breast Neoplasms metabolism, Lymph Nodes metabolism, Receptors, Opioid, kappa metabolism, Receptors, Opioid, mu metabolism
- Abstract
Objective: Breast cancer is a disease of great concern. The prognosis of this tumor is related to its staging. Opioids are widely used to minimize pain in oncology clinics; however, the relationship between the administration of opioids and their effects on tumor cells has yet to be elucidated. Therefore, this study aimed to evaluate the immunoexpression of mu- (μ) and kappa- (κ) opioid receptors and their correlation with markers of angiogenesis, cell proliferation, and apoptosis in biopsies of breast tumors., Methods: Demographic data, tumor characteristics, opioid use, and prognostic factors were collected from medical records. After the selection of the excisional biopsies, immunohistochemistry was performed for μ- and κ-opioid receptors, vascular endothelial growth factor (VEGF), Ki-67, and TUNEL., Results: A significant predominance of Ki-67 and μ-opioid receptor immunoexpression in the lymph nodes was observed in patients administered opioid medications. The luminal A subtype showed higher apoptosis levels (TUNEL) compared to the luminal B subtype. Patients with T4 tumor who had recurrence demonstrated a reduced expression of κ-opioid receptors at the lymph node location. Correlation analyses between the μ and κ opioid markers, VEGF, Ki-67, and TUNEL showed that these findings are likely involved in the same mechanisms the cancer of T4 stage breast cancer., Conclusion: The κ-opioid receptor has a lower immunoexpression in nodal tumor metastasis with recurrence, whereas the μ-opioid receptor is directly related to expression of TUNEL-positive cells in tumors and indirectly to Ki-67 in nodal metastasis. Neither of the two receptors was expressed in the primary tumor or nodal metastasis in relation to VEGF.
- Published
- 2021
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13. Bisphosphonate-related osteonecrosis induced change in alveolar bone architecture in rats with participation of Wnt signaling.
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de Sousa Ferreira VC, Lopes AP, Alves NM, Sousa FRN, Pereira KMA, Gondim DV, Girão VCC, Leitão RFC, and Goes P
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- Animals, Diphosphonates toxicity, Female, Maxilla, Rats, Rats, Wistar, Wnt Signaling Pathway, Zoledronic Acid toxicity, Bisphosphonate-Associated Osteonecrosis of the Jaw, Bone Density Conservation Agents toxicity
- Abstract
Objective: This work aimed to study the role of inflammation in medication-related osteonecrosis of the jaw (MRONJ) in rats with focus on Wnt signaling., Methods: A total of 36 female Wistar rats (12 weeks ± 200 g) were divided into 2 groups (n = 6) in 3 experiments: saline (SAL) and zoledronic acid (ZOL). For MRONJ induction, rats received 0.1 mg/kg of ZOL (ip) 3×/week for 9 weeks. Animals from the SAL group received 0.1 mg/kg of 0.9% SAL, ip 3×/week for 9 weeks. On the 8th week, 3 left upper molars were extracted, and on the 11th week, they were euthanized. Maxillae were evaluated by macroscopic and histopathological analyses; scanning electron microscopy (SEM); immunohistochemistry for DKK-1, Wnt 10b, and caspase-3; and Raman spectrometry. Gingiva was also collected for TNF-α e IL-1β quantification., Results: Bone necrosis was confirmed by healing impairment, reduced number of viable osteocytes, increased caspase-3 immunoexpression, and increased number of empty lacunae (p < 0.05). ZOL enhanced inflammation and increased gingival levels of IL-1β and TNF-α (p < 0.05). Irregular indentations were seen on bone after ZOL administration. Bone necrosis was marked by reduced amount of total and type I collagen. ZOL reduced the mineral/matrix ratio and increased carbonate/phosphate ratio. It was observed a significant reduction on Wnt10b and beta-catenin immunolabeling in the bone tissue of ZOL group., Conclusion: In summary, MRONJ model caused bone necrosis due to intense inflammation. Wnt signaling seems to play an important role in this process., Clinical Relevance: New therapeutic strategies focusing on Wnt pathway can provide an interesting approach for future treatments.
- Published
- 2021
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14. Effect of Dexamethasone-Loaded PLGA Nanoparticles on Oral Mucositis Induced by 5-Fluorouracil.
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Ribeiro SB, de Araújo AA, Oliveira MMB, Santos Silva AMD, da Silva-Júnior AA, Guerra GCB, Brito GAC, Leitão RFC, Araújo Júnior RF, Garcia VB, Vasconcelos RC, and de Medeiros CACX
- Abstract
Oral mucositis (OM) is characterized by the presence of severe ulcers in the oral region that affects patients treated with chemotherapy. It occurs in almost all patients who receive radiotherapy of the head and neck, as well as patients who undergo hematopoietic cell transplantation. The pathophysiology of OM is complex, and there is no effective therapy. The aim of this study was to evaluate the effect of dexamethasone-loaded poly(d,l-Lactic- co -glycolic) nanoparticles (PLGA-DEX NPs) on an OM model induced in hamsters. The NPs were synthesized using the emulsification-solvent evaporation method and were characterized by the size, zeta potential, encapsulation efficiency, atomic force microscopy, physicochemical stability, and the in vitro release. The OM was induced by the administration of 5-FU on the first and second days and mechanical trauma on the 4th day of the experiment. PLGA-DEX NPs were administered to treat OM. The animals were euthanized on the 10th day. Macroscopic and histopathological analyses were performed, measurement of malonaldehyde (MDA) and ELISA was used to determine the levels of IL-1β and TNF-α. Immunoexpressions of NF-κB, COX-2, and TGF-β were determined by immunohistochemistry, and qRT-PCR was used to quantify the gene expression of the GILZ, MKP1, and NF-κB p65. The PLGA-DEX NPs (0.1 mg/kg) significantly reduced macroscopic and histopathological scores, decreased MDA, TNF-α and IL-1β levels, immunostaining for NF-κB, COX-2, TGF-β, and suppressed NF-κB p65 mRNA expression, but increased GILZ and MKP1 expression.
- Published
- 2021
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15. Anti-inflammatory latex proteins of the medicinal plant Calotropis procera: a promising alternative for oral mucositis treatment.
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Ramos MV, Freitas APF, Leitão RFC, Costa DVS, Cerqueira GS, Martins DS, Martins CS, Alencar NMN, Freitas LBN, and Brito GAC
- Subjects
- Animals, Fluorouracil toxicity, Male, Mesocricetus, Stomatitis pathology, Anti-Inflammatory Agents therapeutic use, Calotropis chemistry, Latex chemistry, Plant Proteins therapeutic use, Stomatitis drug therapy
- Abstract
Objective and Design: Oral mucositis (OM) is an intense inflammatory reaction progressing to tissue damage and ulceration. The medicinal uses of Calotropis procera are supported by anti-inflammatory capacity. PII-IAA, a highly homogenous cocktail of laticifer proteins (LP) prepared from the latex of C. procera, with recognized pharmacological properties was tested to treat OM., Materials and Subjects: Male Golden Sirius hamsters were used in all treatments., Treatment: The latex protein samples were injected i.p. (5 mg/Kg) 24 h before mucositis induction (mechanical trauma) and 24 h later., Methods: Histology, cytokine measurements [ELISA], and macroscopic evaluation [scores] were performed., Results: PII-IAA eliminated OM, accompanied by total disappearance of myeloperoxidase activity and release of IL-1b, as well as reduced TNF-a. Oxidative stress was relieved by PII-IAA treatment, as revealed by MDA and GSH measurements. PII-IAA also reduced the expression of adhesion molecules (ICAM-1) and Iba-1, two important markers of inflammation, indicating modulatory effects. Histological analyses of the cheek epithelium revealed greater deposition of type I collagen fibers in animals given PII-IAA compared with the control group. This performance was only reached when LPPII was treated with iodoacetamide (IAA), an irreversible inhibitor of proteolytic activity of cysteine proteases. The endogenous proteolytic activity of LPPII induced adverse effects in animals. Candidate proteins involved in the phytomodulatory activity are proposed., Conclusions: Therapy was successful in treating OM with the laticifer protein fraction, containing peptidases and osmotin, from Calotropis procera. The effective candidate from the latex proteins for therapeutic use is PII-IAA.
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- 2020
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16. Effect of Gold Nanoparticle on 5-Fluorouracil-Induced Experimental Oral Mucositis in Hamsters.
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Vilar CJF, Ribeiro SB, de Araújo AA, Guerra GCB, de Araújo Júnior RF, Brito GAC, Leitão RFC, Pontes DL, Gasparotto LHDS, Oliveira MMB, Viana AD, de Medeiros WMTQ, Bezerra BGP, and de Medeiros CACX
- Abstract
Background: Oral mucositis (OM) is a severe inflammation of the oral mucosal cells associated with chemotherapy and/or radiotherapy-induced toxicity, resulting in epithelial ulcers and higher risk of death from sepsis. The aim of the present study was to evaluate the nanoparticle (AuNp) effect on OM induced in hamsters., Materials and Methods: 5-fluorouracil (5FU) was used on the first and second day of the experimental model in Golden sirian hamsters, and on the fourth day, mechanical trauma was applied to induce OM. The animals were divided into groups, i.e., polyvinylpyrrolidone (PVP), mechanical trauma (MT), 5FU, and groups treated with gold nanoparticles (AuNps) (62.5, 125, and 250 μg/kg). On the 10th day, animals were euthanized for macroscopic, histopathological, immunohistochemical, western blot, quantitative polymerase chain reaction (qRT-PCR), and AuNp quantification., Results: AuNp (250 μg/kg) reduced TNF-α, IL-1β, COX-2, NF-κB, TGF-β, and SMAD 2/3; increased glutathione levels; decreased the expression of Kelch ECH-associated protein 1 (KEAP1); and induced heme oxygenase 1 ( HMOX-1 ) and NAD (P) H quinone oxidoreductase 1 ( NQO1 ) genes., Conclusions: AuNp (250 μg/kg) prevented 5-FU-induced OM in hamsters and improved the parameters of inflammation and oxidative stress.
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- 2020
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17. Role of Inflammatory Markers in Prognosis of Oral Squamous Cell Carcinoma.
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Dantas TS, Barros Silva PG, Lima Verde MEQ, Ribeiro Junior AL, Cunha MDPSS, Mota MRL, Alves APNN, Leitão RFC, and Sousa FB
- Subjects
- Carcinoma, Squamous Cell mortality, Cross-Sectional Studies, Female, Humans, Immunohistochemistry, Lymph Nodes pathology, Lymphatic Metastasis pathology, Male, Middle Aged, Mouth Neoplasms mortality, Prognosis, Retrospective Studies, Survival Rate, Carcinoma, Squamous Cell pathology, Epithelial Cells pathology, Mouth Neoplasms pathology, Tumor Necrosis Factor-alpha metabolism
- Abstract
Background: This estudie evaluated the immunostaining of cytokines in oral carcinoma, in tissue of margin of surgical resecate (MSR) and metastatic lymph nodes, as well as their role in patient prognosis., Methods: A retrospective study was carried out in patients with oral squamous cell carcinomas, and sociodemographic and clinical-pathological data were evaluated. In addition, surgical site analysis of the patients was conducted by immunohistochemistry, using a tissue microarray for inflammatory (Tumor Necrosis Factor-alpha, Interleukin-1beta, Interleukin-6, interleukin-10), transcription NF-kappa B and CD68 markers. Immunoexpression was assessed qualitatively and quantitatively using ImageJ software, and data were correlated with the prognostic factors and patient survival rates., Results: There was a greater immunoexpression of inflammatory and CD68 cytokines in primary tumour and lymph node metastasis than in MSR. In a multinomial logistic regression model, patients with low education (p = 0.041) and a high histoscore for TNF-α (p = 0.021) showed a survival rate of 15.64 (95% CI = 1.13-217.24) and 6.81 (95% CI = 1.02-105.96)., Conclusion: Therefore, despite there is an increased immunoexpression of cytokines in the primary tumour, only TNF-α was the inflammatory cytokine that influenced the survival of patients with oral cancer.
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- 2019
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18. Protective Effect of Cashew Gum (Anacardium occidentale L.) on 5-Fluorouracil-Induced Intestinal Mucositis.
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de Miranda JAL, Barreto JEF, Martins DS, de Souza Pimentel PV, da Silva Costa DV, E Silva RR, de Souza LKM, de Lima CNC, Rocha JA, de Freitas APF, da Silva DA, Scafuri AG, de Leitão RFC, de Castro Brito GA, Medeiros JVR, and Cerqueira GS
- Abstract
Intestinal mucositis is a common complication associated with 5-fluorouracil (5-FU), a chemotherapeutic agent used for cancer treatment. Cashew gum (CG) has been reported as a potent anti-inflammatory agent. In the present study, we aimed to evaluate the effect of CG extracted from the exudate of Anacardium occidentale L. on experimental intestinal mucositis induced by 5-FU. Swiss mice were randomly divided into seven groups: Saline, 5-FU, CG 30, CG 60, CG 90, Celecoxib (CLX), and CLX + CG 90 groups. The weight of mice was measured daily. After treatment, the animals were euthanized and segments of the small intestine were collected to evaluate histopathological alterations (morphometric analysis), levels of malondialdehyde (MDA), myeloperoxidase (MPO), and glutathione (GSH), and immunohistochemical analysis of interleukin 1 beta (IL-1β) and cyclooxygenase-2 (COX-2). 5-FU induced intense weight loss and reduction in villus height compared to the saline group. CG 90 prevented 5-FU-induced histopathological changes and decreased oxidative stress through decrease of MDA levels and increase of GSH concentration. CG attenuated inflammatory process by decreasing MPO activity, intestinal mastocytosis, and COX-2 expression. Our findings suggest that CG at a concentration of 90 mg/kg reverses the effects of 5-FU-induced intestinal mucositis., Competing Interests: The authors declare no conflict of interest.
- Published
- 2019
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19. Gliclazide Prevents 5-FU-Induced Oral Mucositis by Reducing Oxidative Stress, Inflammation, and P-Selectin Adhesion Molecules.
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Mafra CADCC, Vasconcelos RC, de Medeiros CACX, Leitão RFC, Brito GAC, Costa DVDS, Guerra GCB, de Araújo RF Jr, Medeiros AC, and de Araújo AA
- Abstract
Oral mucositis (OM) is one of the main side effects of the head and neck cancer treatment, particularly radiotherapy and/or chemotherapy. OM is characterized by ulcers, erythema, dysphagia, xerostomia, and increased susceptibility to opportunistic infections. In the perspective of finding pharmacological therapies to prevent inflammation and ulceration of OM, the investigation of the pleiotropic effect of commercial drugs is needed, among them gliclazide, an antidiabetic drug. This study aimed to evaluate the effect of gliclazide in an experimental OM model induced by 5-fluorouracil. Male hamsters were pre-treated with oral gliclazide (1, 5, or 10 mg/kg) for 10 days. Cheek pouch samples were subjected to histopathological and immunohistochemical analysis (COX
2 , iNOS, MMP-2, NFκB P65, GPx) and imunofluorescence (P-selectin). IL-1β and TNF-α levels, Myeloperoxidase activity (MPO) and malondialdehyde (MDA) levels were investigated by ultraviolet-visible spectroscopy analysis. NFκB NLS P50 protein levels were analyzed by western blotting. The group treated with gliclazide at a dose of 10 mg/kg showed presence of erythema, no evidence of erosion, and absence of mucosal ulceration with a score of 1 (1-2) ( p < 0.01). Histopathological data for the group treated with gliclazide 10 mg/kg showed re-epithelialization, discrete mononuclear inflammatory infiltrate and absence of hemorrhage, edema, ulcers and abscesses with a score of 1 (1-1) ( p < 0.01). Treatment with gliclazide 10 mg/kg reduced MPO activity ( p < 0.001), MDA levels ( p < 0.001) and NFκB NLS P50 ( p < 0.05) protein levels, resulting in low immunostaining to Cox-2, iNOS ( p < 0.05), NFκB P65 ( p < 0.05), and negative immunoreaction to MMP-2 ( p < 0.001). However, it appeared that for Gpx1, the staining was restored in the GLI 10-FUT group compared with 5FUT/saline ( p < 0.05). Immunofluorescence revealed decreased levels of P-selectin ( p < 0.001) after treatment with gliclazide 10 mg/kg ( p < 0.05). In summary, gliclazide accelerated mucosal recovery and reduced oxidative stress and inflammation in the 5-FU-induced OM in hamsters.- Published
- 2019
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20. 5-Fluorouracil Induces Enteric Neuron Death and Glial Activation During Intestinal Mucositis via a S100B-RAGE-NFκB-Dependent Pathway.
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Costa DVS, Bon-Frauches AC, Silva AMHP, Lima-Júnior RCP, Martins CS, Leitão RFC, Freitas GB, Castelucci P, Bolick DT, Guerrant RL, Warren CA, Moura-Neto V, and Brito GAC
- Subjects
- Animals, Cell Death drug effects, Cytokines metabolism, Down-Regulation drug effects, Enteric Nervous System pathology, Glial Fibrillary Acidic Protein metabolism, Intestinal Mucosa pathology, Male, Mice, Mucositis metabolism, Neuroglia pathology, Oxidative Stress drug effects, Transcription Factor RelA metabolism, Fluorouracil pharmacology, Intestinal Mucosa drug effects, Mucositis pathology, NF-kappa B metabolism, Neuroglia drug effects, Receptor for Advanced Glycation End Products metabolism, S100 Calcium Binding Protein beta Subunit metabolism
- Abstract
5-Fluorouracil (5-FU) is an anticancer agent whose main side effects include intestinal mucositis associated with intestinal motility alterations maybe due to an effect on the enteric nervous system (ENS), but the underlying mechanism remains unclear. In this report, we used an animal model to investigate the participation of the S100B/RAGE/NFκB pathway in intestinal mucositis and enteric neurotoxicity caused by 5-FU (450 mg/kg, IP, single dose). 5-FU induced intestinal damage observed by shortened villi, loss of crypt architecture and intense inflammatory cell infiltrate as well as increased GFAP and S100B co-expression and decreased HuC/D protein expression in the small intestine. Furthermore, 5-FU increased RAGE and NFκB NLS immunostaining in enteric neurons, associated with a significant increase in the nitrite/nitrate, IL-6 and TNF-α levels, iNOS expression and MDA accumulation in the small intestine. We provide evidence that 5-FU induces reactive gliosis and reduction of enteric neurons in a S100B/RAGE/NFκB-dependent manner, since pentamidine, a S100B inhibitor, prevented 5-FU-induced neuronal loss, enteric glia activation, intestinal inflammation, oxidative stress and histological injury.
- Published
- 2019
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21. Protective effect of angiotensin II receptor blocker against oxidative stress and inflammation in an oral mucositis experimental model.
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Araújo AA, Araújo LS, Medeiros CACX, Leitão RFC, Brito GAC, Costa DVDS, Guerra GCB, Garcia VB, Lima MLS, and Araújo Junior RF
- Subjects
- Animals, Antimetabolites, Antineoplastic adverse effects, Cricetinae, Fluorouracil adverse effects, Male, Mesocricetus, Models, Animal, Stomatitis chemically induced, Angiotensin Receptor Antagonists pharmacology, Angiotensin Receptor Antagonists therapeutic use, Cytokines metabolism, Inflammation Mediators metabolism, Olmesartan Medoxomil pharmacology, Olmesartan Medoxomil therapeutic use, Oxidative Stress drug effects, Stomatitis drug therapy, Stomatitis metabolism
- Abstract
Background: The aim of this study was to evaluate the effect of olmesartan medoxomil (Olme), an angiotensin II receptor antagonist, on oral mucositis (OM) experimental model., Methods: Oral mucositis was induced in hamsters with 5-fluorouracil (5-FU; 60 mg/kg day 1 and 40 mg/kg day 2). Animals (n = 10/group) were pretreated with oral Olme (1, 5, or 10 mg/kg) or vehicle 30 minutes before 5-FU injection and daily, until day 10. Cheek pouch samples were subjected to histopathological and immunostaining analysis of IL-1β, TNF-α, IL-10, TGF-β, macrophage migration inhibitory factor (MIF), SOD, MMP-2 and FGF-2. In addition, IL-1β and TNF-α levels were evaluated by ELISA. Myeloperoxidase activity (MPO), glutathione (GSH) and malondialdehyde (MDA) levels were investigated by spectroscopic UV/VIS analysis. Reverse transcriptase polymerase chain reactions (RT-PCRs) were used to quantify the expression of IL-1β, TNF-α, NF-κBp65, MKP1 and ACE2. Inducible nitric oxide synthase (iNOS) and extracellular regulated kinase (ERK)1/2 protein levels were analysed by Western blot., Results: Treatment with 10 mg/kg Olme reduced ulceration, inflammatory cell infiltration, MPO activity, MDA levels, iNOS and ERK1/2 proteins levels, MIF expression and TNF-α and IL-1β of levels and gene expression. These findings were associated with a significant increase in the immunostaining of IL-10, FGF-2 and TGF-β. In addition, gene expression of IL-1β, TNF-α, NF-κBp65 MKP1 and ACE2 was decreased., Conclusion: Olmesartan at a dose of 10 mg/kg prevented the mucosal damage and inflammation associated with 5-FU-induced OM, increasing granulation and tissue repair., (© 2018 The Authors. Journal of Oral Pathology & Medicine Published by John Wiley & Sons Ltd.)
- Published
- 2018
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22. 5-Fluorouracil induces inflammation and oxidative stress in the major salivary glands affecting salivary flow and saliva composition.
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Bomfin LE, Braga CM, Oliveira TA, Martins CS, Foschetti DA, Santos AAQA, Costa DVS, Leitão RFC, and Brito GAC
- Subjects
- Animals, Antineoplastic Agents adverse effects, Cell Death drug effects, Cell Proliferation, Cricetinae, Mucositis pathology, Saliva chemistry, Salivary Glands pathology, Fluorouracil adverse effects, Mucositis chemically induced, Saliva physiology, Salivary Glands drug effects
- Abstract
This study aimed to elucidate the effect of 5-fluorouracil (5-FU) on the histological aspects of the major salivary glands, salivary flow and saliva composition using an established oral mucositis model in hamsters. Oral mucositis was induced by two intraperitoneal administrations of 5-FU in two consecutive days (60 and 40mg/kg), followed by cheek pouch mucosa scratch, on day 4. The Pilocarpine-stimulated salivary flow was measured 4 and 10days after the first 5-FU injection. Salivary glands were harvested for histopathological analysis, measurement of inflammatory cells, quantification of pro-inflammatory cytokines (TNF-α and IL-1β), investigation of cell death and cell proliferation. Oxidative stress and oxidative defense system were also investigated in the salivary gland tissues using MDA (malondialdehyde), nitrite, non-protein sulfhydryl groups (NP-SH), SOD (superoxide dismutase) and CAT (catalase). In addition, the CAT and lysozyme activities and the IgA and SOD levels were evaluated in the saliva samples. 5-FU significantly reduced the pilocarpine-stimulated salivary flow rate on the 4th experimental day, associated with an increase in the SOD levels in saliva. Recovery of the salivary flow and SOD were observed on day 10, when an increase in the saliva lysozyme levels was detected. In addition, 5-FU promoted vacuolization in parotid (P) and periductal edema in submandibular (SM) gland, combined with an increase in the inflammatory cells influx, mostly observed on the 4th day in SM gland and on 4th and 10th days in P. Oxidative stress was found mostly on day 10 in SM, SL and P glands, associated with release of proinflammatory cytokines, observed in SM and SL glands, but not in P. 5-FU induces an inflammatory response in the major salivary glands, most observed ten days after its first injection, which may contribute to the major salivary glands hypofunction, leading to alterations in the salivary flow rate and composition., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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23. Transforming Growth Factor β1/SMAD Signaling Pathway Activation Protects the Intestinal Epithelium from Clostridium difficile Toxin A-Induced Damage.
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Tinoco-Veras CM, Santos AAQA, Stipursky J, Meloni M, Araujo APB, Foschetti DA, López-Ureña D, Quesada-Gómez C, Leitão RFC, Gomes FCA, and Brito GAC
- Subjects
- Animals, Bacterial Proteins metabolism, Bacterial Toxins metabolism, Cell Death drug effects, Cell Line, Cell Survival, Clostridioides difficile pathogenicity, Enterotoxins metabolism, Ileum immunology, Ileum microbiology, Intestinal Mucosa drug effects, Intestinal Mucosa immunology, Intestinal Mucosa pathology, Intestines immunology, Intestines microbiology, Mice, Transforming Growth Factor beta1 genetics, Bacterial Toxins toxicity, Enterotoxins toxicity, Intestinal Mucosa microbiology, Signal Transduction, Smad Proteins metabolism, Transforming Growth Factor beta1 metabolism
- Abstract
Clostridium difficile , the main cause of diarrhea in hospitalized patients, produces toxins A (TcdA) and B (TcdB), which affect intestinal epithelial cell survival, proliferation, and migration and induce an intense inflammatory response. Transforming growth factor β (TGF-β) is a pleiotropic cytokine affecting enterocyte and immune/inflammatory responses. However, it has been shown that exposure of intestinal epithelium to a low concentration of TcdA induces the release of TGF-β1, which has a protective effect on epithelial resistance and a TcdA/TGF-β signaling pathway interaction. The activation of this pathway in vivo has not been elucidated. The aim of this study was to investigate the role of the TGF-β1 pathway in TcdA-induced damage in a rat intestinal epithelial cell line (IEC-6) and in a mouse model of an ileal loop. TcdA increased the expression of TGF-β1 and its receptor, TβRII, in vitro and in vivo TcdA induced nuclear translocation of the transcription factors SMAD2/3, a hallmark of TGF-β1 pathway activation, both in IEC cells and in mouse ileal tissue. The addition of recombinant TGF-β1 (rTGF-β) prevented TcdA-induced apoptosis/necrosis and restored proliferation and repair activity in IEC-6 cells in the presence of TcdA. Together, these data show that TcdA induces TGF-β1 signaling pathway activation and suggest that this pathway might play a protective role against the effect of C. difficile -toxin., (Copyright © 2017 American Society for Microbiology.)
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- 2017
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24. Role of the route of leukotrienes in an experimental model of oral mucositis induced by 5-fluorouracil 1.
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Silva VCD, Leitão RFC, Brito GAC, Martins CDS, Freire GE, Aragão KS, Wanderley CWS, and Freitas MR
- Subjects
- Animals, Cricetinae, Disease Models, Animal, Fluorouracil, Immunohistochemistry, Male, Stomatitis chemically induced, Stomatitis metabolism, Cysteine metabolism, Cytokines metabolism, Leukotrienes metabolism, Stomatitis prevention & control
- Abstract
Purpose: To investigate the participation of cysteinyl leukotrienes in the pathophysiology of oral mucositis., Methods: Oral mucositis was induced in hamsters using 5-fluorouracil (5-FU; 60 and 40 mg/kg; i.p., on days 1 and 2, respectively, and with excoriations in jugal mucosa on day 4). Montelukast (10, 20, or 40 mg/kg/d; gavage), MK886 (3 mg/kg/d, i.p.), or saline or celecoxib (7.5 mg/kg/d; i.p.) was administered 1 h prior to 5-FU and daily, until the fourth (MK886) or tenth day, when the animals were euthanized and their jugal mucosa was collected for macroscopic, histopathological, and immunohistochemical evaluation., Results: Neither montelukast nor MK-886 prevented the oral mucositis induced by 5-FU, as observed by histopathological evaluation. In addition, we did not find significant differences in the expression of inducible nitric oxide synthase-2, cyclooxygenase-2, or interleukin (IL)-1β between the experimental and control groups. However, we did observe a significant decrease in tumor necrosis factor (TNF)-α expression for all doses of montelukast; we also observed a significant decrease in IL-10 with 40 mg/kg/d and MK 886., Conclusions: Cysteinyl leukotrienes do not play an important role in experimental oral mucositis induced by 5-FU. There is a modulating action specifically on TNF-α.
- Published
- 2017
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25. Effects of metformin on inflammation, oxidative stress, and bone loss in a rat model of periodontitis.
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Araújo AA, Pereira ASBF, Medeiros CACX, Brito GAC, Leitão RFC, Araújo LS, Guedes PMM, Hiyari S, Pirih FQ, and Araújo Júnior RF
- Subjects
- Alveolar Bone Loss diagnostic imaging, Alveolar Bone Loss metabolism, Alveolar Bone Loss pathology, Animals, Disease Models, Animal, Gingiva metabolism, Glutathione Peroxidase metabolism, Inflammation diagnostic imaging, Inflammation drug therapy, Inflammation metabolism, Inflammation pathology, Interleukin-1beta metabolism, Male, Malondialdehyde metabolism, Matrix Metalloproteinase 9 metabolism, Metformin therapeutic use, NF-kappa B metabolism, Periodontitis diagnostic imaging, Periodontitis metabolism, Periodontitis pathology, RANK Ligand metabolism, Rats, Rats, Wistar, Receptor Activator of Nuclear Factor-kappa B metabolism, Tumor Necrosis Factor-alpha metabolism, X-Ray Microtomography, Glutathione Peroxidase GPX1, Alveolar Bone Loss drug therapy, Metformin pharmacology, Oxidative Stress drug effects, Periodontitis drug therapy
- Abstract
Aim: To evaluate the effects of metformin (Met) on inflammation, oxidative stress, and bone loss in a rat model of ligature-induced periodontitis., Materials & Methods: Male albino Wistar rats were divided randomly into five groups of twenty-one rats each, and given the following treatments for 10 days: (1) no ligature + water, (2) ligature + water, (3) ligature + 50 mg/kg Met, (4) ligature + 100 mg/kg Met, and (5) ligature + 200 mg/kg Met. Water or Met was administered orally. Maxillae were fixed and scanned using Micro-computed Tomography (μCT) to quantitate linear and bone volume/tissue volume (BV/TV) volumetric bone loss. Histopathological characteristics were assessed through immunohistochemical staining for MMP-9, COX-2, the RANKL/RANK/OPG pathway, SOD-1, and GPx-1. Additionally, confocal microscopy was used to analyze osteocalcin fluorescence. UV-VIS analysis was used to examine the levels of malondialdehyde, glutathione, IL-1β and TNF-α from gingival tissues. Quantitative RT-PCR reaction was used to gene expression of AMPK, NF-κB (p65), and Hmgb1 from gingival tissues. Significance among groups were analysed using a one-way ANOVA. A p-value of p<0.05 indicated a significant difference., Results: Treatment with 50 mg/kg Met significantly reduced concentrations of malondialdehyde, IL-1β, and TNF-α (p < 0.05). Additionally, weak staining was observed for COX-2, MMP-9, RANK, RANKL, SOD-1, and GPx-1 after 50 mg/kg Met. OPG and Osteocalcin showed strong staining in the same group. Radiographically, linear measurements showed a statistically significant reduction in bone loss after 50 mg/kg Met compared to the ligature and Met 200 mg/kg groups. The same pattern was observed volumetrically in BV/TV and decreased osteoclast number (p<0.05). RT-PCR showed increased AMPK expression and decreased expression of NF-κB (p65) and HMGB1 after 50 mg/kg Met., Conclusions: Metformin, at a concentration of 50 mg/kg, decreases the inflammatory response, oxidative stress and bone loss in ligature-induced periodontitis in rats.
- Published
- 2017
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