Publications by authors named "Marcell C Medeiros"

Background: Oral squamous cell carcinoma (SCC) is associated with oral microbial dysbiosis. In this unique study, we compared pre- to post-treatment salivary microbiome in patients with SCC by 16S rRNA gene sequencing and examined how microbiome changes correlated with the expression of an anti-microbial protein.

Results: Treatment of SCC was associated with a reduction in overall bacterial richness and diversity.

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Purpose: Galanin receptor 2 (GALR2) plays a significant role in the progression of head and neck squamous cell carcinomas (HNSCC). Since there is virtually no information on immunomodulation mediated by its ligand in the tumor microenvironment, we assessed the effects of galanin on peripheral blood mononuclear cells (PBMCs).

Methods: After verification of GALR2 expression and it activity in PBMCs we evaluated the effect of galanin and conditioned media from HNSCC cell lines silenced for galanin or antibody-depleted, on proliferation, apoptosis, cytokine expression and activation/differentiation of immune cells.

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Background: Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer worldwide, with human papillomavirus (HPV)-related HNSCC rising to concerning levels. Extensive clinical, genetic and epigenetic differences exist between HPV-associated HNSCC and HPV-negative HNSCC, which is often linked to tobacco use. However, 5-hydroxymethylation (5hmC), an oxidative derivative of DNA methylation and its heterogeneity among HNSCC subtypes, has not been studied.

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Objectives: The aim of this study was to evaluate the effect of specific inhibition of MMP-13 on inflammation and inflammatory bone resorption in a murine model of lipopolysaccharide (LPS)-induced periodontitis.

Materials And Methods: Periodontitis was induced in mice by micro-injections of LPS into the gingival tissues adjacent to the palatal surfaces of maxillary molars twice a week for 15 days. Matrix metalloproteinase-13 (Mmp-13) shRNA or a specific biochemical inhibitor were also injected into the same sites in alternating days with the LPS injections.

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Objective: The aim of this study was to investigate the functionality of ATC/TTC (Hap-1) and ATT/TTC (Hap-2) Interleukin (IL) 8 gene haplotypes in the response of neutrophils to Gram-negative bacteria associated with periodontitis.

Design: Neutrophils were isolated by gradient centrifugation from whole peripheral blood of systemically healthy individuals presenting the two IL8 gene haplotypes. Neutrophils were stimulated with P.

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Individuals carrying the ATC/TTC haplotype (Hap-1) in the interleukin 8 (IL8) gene were reported as more susceptible to chronic periodontitis (CP), an infectious disease associated with Gram-negative bacteria, in comparison to patients with the ATT/TTC haplotype (Hap-2). This study investigated the functionality of the IL8 haplotypes in lymphocytes and monocytes of individuals carrying the Hap-1 or Hap-2 IL8 haplotypes in the response to CP-associated Gram-negative bacteria (periodontopathogens). Peripheral blood was collected from 6 subjects carrying each haplotype, and their immune cells were challenged with periodontopathogens or phorbol 12-myristate 13-acetate (PMA) plus Ionomycin.

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Objectives: Studies have documented the anti-inflammatory effects of spices, which may be related to treatment of chronic diseases. The purpose of this study was to evaluate the influence of curcumin and piperine and their association on experimental periodontal repair in rats.

Materials And Methods: Periodontitis was induced via the installation of a ligature around the first molar.

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Objective: The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) on the healing of biomaterial graft areas (i.e., coagulum, deproteinized bovine bone, and biphasic ceramics comprising hydroxyapatite and β-tricalcium phosphate).

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This study aimed to characterize the dynamics of suppressor of cytokine signaling (SOCS1) expression in a rat model of lipopolysaccharide-induced periodontitis. Wistar rats in the experimental groups were injected three times/week with LPS from Escherichia coli on the palatal aspect of the first molars, and control animals were injected with vehicle (phosphate-buffered saline). Animals were sacrificed 7, 15, and 30 days after the first injection to analyze inflammation (stereometric analysis), bone loss (macroscopic analysis), gene expression (qRT-PCR), and protein expression/activation (Western blotting).

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The immune system detects shifts from homeostasis and eliminates altered cells. However, neoplastic cells can modulate the host response to escape immunosurveillance thereby allowing tumor progression. Head and neck squamous cell carcinoma (HNSCC) is one of the most immunosuppressive cancers but its role in co-opting the immune system to actively promote tumor growth has not been investigated.

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Chronic periodontitis (CP) is an infectious inflammatory disease that affects tooth-supporting structures and in which dental plaque bacteria, immune mechanisms and genetic predisposition play important roles. Interleukin 4 (IL-4) is a key anti-inflammatory cytokine with relevant action in imbalances in inflamed periodontal tissue. Individuals carrying the TCI/CCI genotype (S-haplotype) of the IL-4 gene are 5 times more susceptible to CP, whereas the CTI/TTD genotype (P-haplotype) confers protection against CP.

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Bone regeneration is a process that involves several molecular mediators, such as growth factors, which directly affect the proliferation, migration and differentiation of bone-related cells. The osteogenic growth peptide (OGP) and its C-terminal pentapeptide OGP(10-14) have been shown to stimulate the proliferation, differentiation, alkaline phosphatase activity and matrix mineralization of osteoblastic lineage cells. However, the exact molecular mechanisms that promote osteoblastic proliferation and differentiation are not completely understood.

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NOD2 is a member of the NLR family of proteins that participate in the activation of the innate immune response. RIP2 is a downstream kinase activated by both NOD1 and NOD2. There is scarcity of information regarding the relevance of NOD2 in periodontitis, a chronic inflammatory condition characterized by inflammatory bone resorption.

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Objective: The aim of this study was to evaluate a possible synergism between AGE-RAGE and TLR4 signaling and the role of p38 MAPK and NF-kB signaling pathways on the modulation of the expression of inflammatory cytokines and proliferation of cells from the innate and adaptive immune response.

Material And Methods: T lymphocyte (JM) and monocyte (U937) cell lines were stimulated with LPS and AGE-BSA independently and associated, both in the presence and absence of p38 MAPK and NF-kB inhibitors. Proliferation was assessed by direct counting and viability was assessed by a biochemical assay of mitochondrial function.

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