Papers by Marcelo Marques
Calcified tissue international, 2014
Parathyroid hormone (PTH) plays a key role in the development and homeostasis of mineralized tiss... more Parathyroid hormone (PTH) plays a key role in the development and homeostasis of mineralized tissues such as bone and dentine. We have reported that PTH (1-34) administration can increase dentine formation in mice and that this hormone modulates in vitro mineralization of odontoblast-like cells. The purpose of the present study was to investigate whether PTH (1-34) participates in the proliferative and apoptotic signaling of odontoblast-like cells (MDPC23). MDPC23 cells were exposed to 50 ng/ml hPTH (1-34) or vehicle for 1 (P1), 24 (P24), or 48 (P48) hours, and the cell proliferation, apoptosis, and cell number were evaluated. To examine whether changes in the proliferative and apoptotic signaling in response to PTH involve protein kinases A (PKA) and/or C (PKC), MDPC23 cells were exposed to PTH with or without PKC or PKA signaling pathway inhibitors. Overall, the results showed that the PKA pathway acts in response to PTH exposure maintaining levels of cell proliferation, while the...
PLoS ONE, 2010
Aggressive periodontitis is characterized by a rapid and severe periodontal destruction in young ... more Aggressive periodontitis is characterized by a rapid and severe periodontal destruction in young systemically healthy subjects. A greater prevalence is reported in Africans and African descendent groups than in Caucasians and Hispanics. We first fine mapped the interval 1q24.2 to 1q31.3 suggested as containing an aggressive periodontitis locus. Three hundred and eighty-nine subjects from 55 pedigrees were studied. Saliva samples were collected from all subjects, and DNA was extracted. Twenty-one single nucleotide polymorphisms were selected and analyzed by standard polymerase chain reaction using TaqMan chemistry. Non-parametric linkage and transmission distortion analyses were performed. Although linkage results were negative, statistically significant association between two markers, rs1935881 and rs1342913, in the FAM5C gene and aggressive periodontitis (p = 0.03) was found. Haplotype analysis showed an association between aggressive periodontitis and the haplotype A-G (rs1935881-rs1342913; p = 0.009). Sequence analysis of FAM5C coding regions did not disclose any mutations, but two variants in conserved intronic regions of FAM5C, rs57694932 and rs10494634, were found. However, these two variants are not associated with aggressive periodontitis. Secondly, we investigated the pattern of FAM5C expression in aggressive periodontitis lesions and its possible correlations with inflammatory/immunological factors and pathogens commonly associated with periodontal diseases. FAM5C mRNA expression was significantly higher in diseased versus healthy sites, and was found to be correlated to the IL-1b, IL-17A, IL-4 and RANKL mRNA levels. No correlations were found between FAM5C levels and the presence and load of red complex periodontopathogens or Aggregatibacter actinomycetemcomitans. This study provides evidence that FAM5C contributes to aggressive periodontitis.
Human Genetics, 2014
G"Quadruplexes-are-secondary-structures-present-in-DNA-and-RNA-molecules,-which-areformed-by-stac... more G"Quadruplexes-are-secondary-structures-present-in-DNA-and-RNA-molecules,-which-areformed-by-stacking-of-G"quartets-(i.e.-interaction-of-four-guanines-(G"tracts)-bounded-by-Hoogsteen-hydrogen-bonding).-Human-PAX9intron-1-has-a-putative-G"quadruplex" forming-region-located-near-exon-1,-which-is-conserved-among-placental-mammals.-Using-Circular-Dichroism-(CD)-analysis,-and-CD-melting-we-showed-that-this-region-isable-to-form-highly-stable-quadruplex-structures.-Due-to-the-proximity-of-the-quadruplexstructure-to-exon"intron-boundary-we-used-a-validated-double-reporter-splicing-assayand-real-time-PCR-to-analyze-its-role-on-splicing-efficiency.-The-human-quadruplex-wasshown-to-have-a-key-role-on-splicing-efficiency-of-PAX9intron-1,-as-a-mutation-thatabolished-quadruplex-formation-decreased-dramatically-splicing-efficiency.-The-lessstable,-rat-quadruplex-had-a-less-efficient-splicing-when-comparing-to-human-sequences.-Additionally,-the-treatment-with-360A,-a-strong-ligand-that-stabilizes-quadruplexstructures,-further-increased-splicing-efficiency-of-human-PAX9intron-1.-Altogetherthese-results-provide-evidences-that-G"quadruplex-structures-are-involved-in-splicingefficiency-of-PAX9-intron-1.
Journal of Periodontology, 2010
This study evaluates the ligature-induced bone loss (BL) and quality of tooth-supporting alveolar... more This study evaluates the ligature-induced bone loss (BL) and quality of tooth-supporting alveolar bone in spontaneously hypertensive rats (SHRs) by histometric, histochemical, and immunohistochemical analyses and assesses the effects of lercanidipine on these parameters. Wistar rats and SHRs were assigned to one of the following groups: normotensive rats (n = 15), untreated SHRs (n = 15), and treated SHRs (n = 15). The latter group was treated daily with lercanidipine for 45 days. Two weeks after the beginning of drug administration, the first right mandibular molar received a cotton ligature, whereas the contralateral tooth was left unligated. The following parameters were analyzed in the furcation area of decalcified histologic sections: BL, bone density (BD), number of positive cells for tartrate-resistant acid phosphatase (TRAP+), and expression of receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG). In ligated teeth, no significant differences among groups were found regarding BL, TRAP+ cells, and the ratio of RANKL/OPG+ cells (P >0.05), although the expression of RANKL was decreased in the treated SHR group (P <0.05). Increased BL and decreased BD were observed around unligated teeth of the untreated and treated SHR groups (P <0.05). In the furcation area of the unligated teeth, the untreated SHR group presented a higher number of TRAP+ cells and higher ratio of RANKL/OPG+ cells compared to the other groups. SHRs present harmful alterations in the quality of tooth-supporting bone, independently of inflammation. In addition, the administration of lercanidipine for 45 days decreased the expression of bone-resorption markers.
Archives of Oral Biology, 2014
The aim of the present study was to assess the impact of chronic consumption of Cachaça on alveol... more The aim of the present study was to assess the impact of chronic consumption of Cachaça on alveolar bone loss (BL) induced by ligature and on alveolar bone density (BD) in peripubertal rats. Male Wistar rats were assigned into one of the following groups: non-ingestion of Cachaça (n=15); Cachaça: ingestion of ascending concentrations of Cachaça during 100 days (n=15). 70th day after the beginning of Cachaça ingestion, one first mandibular molar received a ligature while the contralateral tooth was left unligated. After 30 days, the rats were killed. BL, BD, the positive cells for tartrate-resistant acid phosphatase (TRAP), receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) were analyzed in the furcation area of the ligated and unligated mandibular molars. The Cachaça group presented greater BL (0.75±0.1mm(2) for Cachaça and 0.66±0.1mm(2) for control group, respectively) and number of RANKL and OPG+ cells and lower BD (60.3±4.2% for Cachaça and 76.8±3.8% for control group, respectively) and number of TRAP+ cells around ligated teeth (p<0.05), when compared to the control group. The Cachaça group (0.42±0.02mm(2)) also presented a higher BL around unligated teeth when compared to control group (0.31±0.05mm(2)). Cachaça consumption per se and in the presence of ligature negatively affects alveolar bone by increasing the alveolar BL and reducing BD.
Archives of Oral Biology, 2012
The primary role of PTH, an 84-amino acid peptide that is produced by the parathyroid gland, is r... more The primary role of PTH, an 84-amino acid peptide that is produced by the parathyroid gland, is related to calcium homeostasis. PTH directly increases renal tubular calcium reabsorption and indirectly enhances intestinal calcium absorption. The normal physiological role of PTH on skeletal homeostasis, when secreted endogenously, is more complex, and its main function is to regulate bone remodelling rather than overall skeletal mass. 1 Intermittent PTH administration has an anabolic effect, increasing bone formation over resorption, resulting in increased bone mass. Thus, human parathyroid hormone (hPTH 1-84) and its analogue, recombinant hPTH 1-34, can be used to treat osteoporosis, which was demonstrated in studies with rodents 2,3 and humans. 1,4 Additionally, it was shown that the anabolic effect of PTH is able to accelerate the repair of bone fractures in monkeys 5 and rats. 6 Although many cell types, such as periodontal ligament cells, 7 dental pulp cells, 8-10 and odontoblasts, 11-14 can respond to PTH, most studies that investigated the effects of this a r c h i v e s o f o r a l b i o l o g y 5 7 (2 0 1 2) 1 3 1 3-1 3 1 9
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Papers by Marcelo Marques