TEGDMA-induced oxidative DNA damage and activation of ATM and MAP kinases

The development of strategies for the protection of oral tissues against the adverse effects of resin monomers is primarily based on the elucidation of underlying molecular mechanisms. The generation of reactive oxygen species beyond the capacity of a balanced redox regulation in cells is probably a cause of cell damage. This study was designed to investigate oxidative DNA damage, the activation of ATM, a reporter of DNA damage, and redox-sensitive signal transduction through mitogen-activated protein kinases (MAPKs) by the monomer triethylene glycol dimethacrylate (TEGDMA). TEGDMA concentrations as high as 3-5 mm decreased THP-1 cell viability after a 24 h and 48 h exposure, and levels of 8-oxoguanine (8-oxoG) increased about 3- to 5-fold. The cells were partially protected from toxicity in the presence of N-acetylcysteine (NAC). TEGDMA also induced a delay in the cell cycle. The number of THP-1 cells increased about 2-fold in G1 phase and 5-fold in G2 phase in cultures treated with 3-5 mm TEGDMA. ATM was activated in THP-1 cells by TEGDMA. Likewise, the amounts of phospho-p38 were increased about 3-fold by 3 mm TEGDMA compared to untreated controls after a 24 h and 48 h exposure period, and phospho-ERK1/2 was induced in a very similar way. The activation of both MAPKs was inhibited by NAC. Our findings suggest that the activation of various signal transduction pathways is related to oxidative stress caused by a resin monomer. Signaling through ATM indicates oxidative DNA damage and the activation of MAPK pathways indicates oxidative stress-induced regulation of cell survival and apoptosis. (C) 2008 Elsevier Ltd. All rights reserved.

MAP Kinase Phosphatase-1 Protects against Inflammatory Bone Loss

The mitogen-activated protein (MAP) kinase phosphatase (MKP) family plays an important function in regulating the pro-inflammatory cytokines by deactivating MAP kinases. MKP-1 is essential for the dephosphorylation of p38 MAP kinase that regulates expression of IL-6, TNF-alpha, and IL-1 beta. We hypothesized that MKP-1 regulates inflammatory bone loss in experimental periodontitis. Wild-type and Mkp-1(-/-) mice received A. actinomycetemcomitans LPS injection in the palatal region or PBS control 3 times/wk for 30 days. Mice were killed, and maxillae were assessed by microcomputed tomography, histological analysis, and TRAP staining for measurement of bone loss, extent of inflammation, and degree of osteoclastogenesis. Results indicated that, in LPS-injected Mkp-1(-/-) mice, significantly greater bone loss occurred with more inflammatory infiltrate and a significant increase in osteoclastogenesis compared with Mkp-1(-/-) control sites or either wild-type group. Analysis of these data indicates that MKP-1 plays a key role in the regulation of inflammatory bone loss.

Experimental evidence of MAP kinase gene expression on the response of intestinal anti-inflammatory drugs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Curcurnin abrogates LPS-induced pro-inflammatory cytokines in RAW 264.7 macrophages. Evidence for novel mechanisms involving SOCS-1,-3 and p38 MAPK

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oocyte activation and preimplantation development of bovine embryos obtained by specific inhibition of cyclin-dependent kinases

Realizaram-se dois experimentos para avaliar a eficiência da bohemina e roscovitina associadas à ionomicina para ativação partenogenética e desenvolvimento embrionário inicial de bovinos. No primeiro, foram testadas diferentes concentrações (0, 50, 75 ou 100µM) e diferentes tempos de exposição (2, 4 ou 6 horas) à bohemina ou à roscovitina na ativação de oócitos bovinos maturados in vitro (MIV) pré-expostos à ionomicina. Os melhores tratamentos, bohemina 75µM e roscovitina 50µM, ambos por seis horas, foram utilizados no segundo experimento, no qual oócitos bovinos MIV foram expostos à ionomicina seguido ou não pelo tratamento com inibidores específicos das quinases dependentes de ciclina (CDKI), e avaliados quanto à configuração nuclear, taxa de ativação e desenvolvimento até blastocisto. Os tratamentos combinados (ionomicina+CDKI) apresentaram melhor taxa de ativação (77,3%) e desenvolvimento embrionário inicial (35,2%) do que a ionomicina sozinha (69,4% e 21,9%, respectivamente), e também promoveram ativação mais uniforme (aproximadamente 90% de formação de um pronúcleo). Estes resultados demonstram que os CDKIs potencializam o efeito da ionomicina na ativação e desenvolvimento embrionário inicial e podem auxiliar na obtenção de protocolos de ativação mais eficientes, aumentando a capacidade de desenvolvimento de embriões produzidos por meio de biotécnicas reprodutivas.

A microsatellite-based, gene-rich linkage map for the AA genome of Arachis (Fabaceae)

Cultivated peanut (Arachis hypogaea) is an important crop, widely grown in tropical and subtropical regions of the world. It is highly susceptible to several biotic and abiotic stresses to which wild species are resistant. As a first step towards the introgression of these resistance genes into cultivated peanut, a linkage map based on microsatellite markers was constructed, using an F-2 population obtained from a cross between two diploid wild species with AA genome (A. duranensis and A. stenosperma). A total of 271 new microsatellite markers were developed in the present study from SSR-enriched genomic libraries, expressed sequence tags (ESTs), and by data-mining sequences available in GenBank. of these, 66 were polymorphic for cultivated peanut. The 271 new markers plus another 162 published for peanut were screened against both progenitors and 204 of these (47.1%) were polymorphic, with 170 codominant and 34 dominant markers. The 80 codominant markers segregating 1:2:1 (P < 0.05) were initially used to establish the linkage groups. Distorted and dominant markers were subsequently included in the map. The resulting linkage map consists of 11 linkage groups covering 1,230.89 cM of total map distance, with an average distance of 7.24 cM between markers. This is the first microsatellite-based map published for Arachis, and the first map based on sequences that are all currently publicly available. Because most markers used were derived from ESTs and genomic libraries made using methylation-sensitive restriction enzymes, about one-third of the mapped markers are genic. Linkage group ordering is being validated in other mapping populations, with the aim of constructing a transferable reference map for Arachis.

A linkage map for the B-genome of Arachis (Fabaceae) and its synteny to the A-genome

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Squamata, Elapidae, Micrurus surinamensis (Cuvier, 1817): new records and distribution map in the state of Mato Grosso, Brazil, with notes on diet and activity period.

We report six new records of M. surinamensis and present the map of distribution with known records for this species of semiaquatic coral snake in the state of Mato Grosso, Brazil.

A radiation hybrid map of river buffalo (Bubalus bubalis) chromosome 7 and comparative mapping to the cattle and human genomes

A preliminary radiation hybrid (RH) map containing 50 loci on chromosome 7 of the domestic river buffalo Bubalus bubalis (BBU; 2n = 50) was constructed based on a comparative mapping approach. The RH map of BBU7 includes thirty-seven gene markers and thirteen microsatellites. All loci have been previously assigned to Bos taurus (BTA) chromosome BTA6, which is known for its association with several economically important milk production traits in cattle. The map consists of two linkage groups spanning a total length of 627.9 cR(5,000). Comparative analysis of the BBU7 RH 5,000 map with BTA6 in cattle gave new evidence for strong similarity between the two chromosomes over their entire length and exposed minor differences in locus order. Comparison of the BBU7 RH 5,000 map with the Homo sapiens (HSA) genome revealed similarity with a large chromosome segment of HSA4. Comparative analysis of loci in both species revealed more variability than previously known in gene order and several chromosome rearrangements including centromere relocation. The data obtained in our study define the evolutionarily conserved segment on BBU7 and HSA4 to be between 3.5 megabases (Mb) and 115.8 Mb in the HSA4 (genome build 36) DNA sequence. Copyright (c) 2008 S. Karger AG, Basel.

A radiation hybrid map of river buffalo (Bubalus bubalis) chromosome 1 (BBU1)

The largest chromosome in the river buffalo karyotype, BBU1, is a submetacentric chromosome with reported homology between BBU1q and bovine chromosome 1 and between BBU1p and BTA27. We present the first radiation hybrid map of this chromosome containing 69 cattle derived markers including 48 coding genes, 17 microsatellites and four ESTs distributed in two linkage groups spanning a total length of 1330.1 cR(5000). The RH map was constructed based on analysis of a recently developed river buffalo-hamster whole genome radiation hybrid (BBURH5000) panel. The retention frequency of individual markers across the panel ranged from 17.8 to 52.2%. With few exceptions, the order of markers within linkage groups is identical to the order established for corresponding cattle RH maps. The BBU1 map provides a starting point for comparison of gene order rearrangements between river buffalo chromosome 1 and its bovine homologs. Copyright (C) 2007 S. Karger AG, Basel.

First radiation hybrid map of the river buffalo X chromosome (BBUX) and comparison with BTAX

We report the first radiation hybrid map of the river buffalo X chromosome generated from a recently constructed river buffalo (Bubalus bubalis) whole-genome radiation hybrid panel (BBURH5000). This map contains a total of 33 cattle-derived markers, including 10 genes, four ESTs and 19 microsatellites. The markers are distributed in two linkage groups: LG1 contains eight markers spanning 125.6 cR, and LG2 contains 25 markers spanning 366.3 cR. LG1 contains six markers in common with bovine sequence assembly BUILD 3.1. With the exception of BMS2152, the order of these markers on our BBUX map is shuffled when compared to the cow X chromosome (Bos taurus; BTAX). From LG2, two markers (AMELX and BL22) map to a more distal portion of BTAX compared to BBUX. In addition, two pairs of LG2 markers exhibit inversions compared to BTAX (ILSTS017 and ATRX; XBM38 and PPEF1). Alternatively, when compared to the most recent bovine RH map (Bov-Gen 3000rads), BL1098 and BMS2227 from LG1 as well as PLS3 and BMS1820 from LG2 showed inverted positions on the BBUX map. These discrepancies in buffalo and cattle maps may reflect evolutionary divergence of the chromosomes or mapping errors in one of the two species. Although the set of mapped markers does not cover the entire X chromosome, this map is a starting point for the construction of a high-resolution map, which is necessary for characterization of small rearrangements that might have occurred between the Bubalus bubalis and Bos taurus X chromosomes.

A first generation whole genome RH map of the river buffalo with comparison to domestic cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Preliminary radiation hybrid map for river buffalo chromosome 6 and comparison to bovine chromosome 3

We present the first radiation hybrid (RH) map of river buffalo (Bubalus bubalis) chromosome 6 (BBU6) developed with a recently constructed river buffalo whole-genome RH panel (BBURH5000). The preliminary map contains 33 cattle-derived markers, including 12 microsatellites, 19 coding genes and two ESTs, distributed across two linkage groups. Retention frequencies for markers ranged from 14.4% to 40.0%. Most of the marker orders within the linkage groups on BBU6 were consistent with the cattle genome sequence and RH maps. This preliminary RH map is the starting point for comparing gene order between river buffalo and cattle, presenting an opportunity for the examination of micro-rearrangements of these chromosomes. Also, resources for positional candidate cloning in river buffalo are enhanced.

Structural bioinformatics study of cyclin-dependent kinases complexed with inhibitors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)