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Biology subjects

Castell, S. D.

Publications and source records attributed to Castell, S. D..

2 recordsLinked to original sources

Salivary Proinflammatory Cytokines IL-1β, IL-6 And TNF Decrease With Age.

Objectiveto analyze salivary concentrations interleukin-1{beta} (IL-1{beta}), 6 (IL-6) and tumor necrosis factor (TNF) according to age in healthy subjects to determine baseline inflammatory state of the oral mucosa in elderly subjects, who are at higher risk of developing inflammation-related diseases. Materials and methodssixty-four healthy volunteers were divided into groups according to age: 20-39 (G1; n=20); 40-59 (G2; n=24); 60-80 years (G3; n=20). Their stomatognathic system and periodontal status were assessed; consumption of food sources of fatty acids (FA) was evaluated using a validated food frequency questionnaire. IL-1{beta}, IL-6, and TNF salivary levels were determined (ELISA) in mixed unstimulated saliva. Kruskal Wallis and Spearmans correlation tests were applied (p<0.05). Resultssalivary IL-1{beta} and TNF levels were lower in G2 (p=0.001) and G3 (p<0.001) than in G1; IL-6 levels were lower in G3 than in G2 and G1 (p= <0.001). IL-1{beta} showed the highest concentration in all groups (p<0.001). No statistically significant differences in salivary cytokine levels were observed on sex in any of the groups. Associations were observed between salivary cytokines and consumption of some foods containing FA. Conclusionsalivary concentration of proinflammatory cytokines decreased with age. It could be influenced by ageing-related changes. In addtition, the baseline inflammatory state of the oral mucosa would appear to be influenced by dietary intake of sources of anti-inflammatory FA. Clinical relevancethe knowledge about inflammatory state of the oral mucosa, as determined by salivary cytokine concentrations, could be useful for understanding and prevention of developing inflammation-related diseases.

pathology↗

New insights into how MutS separates its function in the regulation of the Pol IV access to replication sites from that in the conserved MMR pathway

MutS initiates mismatch repair by recognizing mismatches in newly replicated DNA. Specific interactions between MutS and mismatches within double-stranded DNA promote ADP-ATP exchange and a conformational change into a sliding clamp. Here, we demonstrated that MutS from Pseudomonas aeruginosa associates with primed DNA replication substrates. The predicted structure of this MutS-DNA complex revealed a new DNA binding site, in which Asn 279 and Arg 272 appeared to directly interact with the 3-OH terminus of primed DNA. Mutation of these residues resulted in a noticeable defect in the interaction of MutS with replication DNA substrates. Remarkably, MutS interaction with a mismatch within primed DNA induced a compaction of the protein structure and impaired the formation of an ATP-bound sliding clamp. Our findings reveal a novel DNA binding mode, conformational change and intramolecular signaling for MutS recognition of mismatches within DNA replication structures.

biochemistry↗