Cementum is the outer-, mineralized-tissue covering the tooth root and an essential part of the system of periodontal tissue that anchors the tooth to the bone. Periodontal disease results from the destructive behavior of the host elicited by an infectious biofilm adhering to the tooth root and left untreated, may lead to tooth loss. We describe a novel protocol for identifying peptide sequences from native proteins with the potential to repair damaged dental tissues by controlling hydroxyapatite biomineralization. Using amelogenin as a case study and a bioinformatics scoring matrix, we identified regions within amelogenin that are shared with a set of hydroxyapatite-binding peptides (HABPs) previously selected by phage display. One 22-amino acid long peptide regions referred to as amelogenin-derived peptide 5 (ADP5) was shown to facilitate cell-free formation of a cementum-like hydroxyapatite mineral layer on demineralized human root dentin that, in turn, supported attachment of periodontal ligament cells in vitro. Our findings have several implications in peptide-assisted mineral formation that mimic biomineralization. By further elaborating the mechanism for protein control over the biomineral formed, we afford new insights into the evolution of protein-mineral interactions. By exploiting small peptide domains of native proteins, our understanding of structure-function relationships of biomineralizing proteins can be extended and these peptides can be utilized to engineer mineral formation. Finally, the cementomimetic layer formed by ADP5 has the potential clinical application to repair diseased root surfaces so as to promote the regeneration of periodontal tissues and thereby reduce the morbidity associated with tooth loss.
Amelogenin ; chemistry ; physiology ; Biomimetic Materials ; chemistry ; Calcium-Binding Proteins ; Carrier Proteins ; physiology ; Cementogenesis ; physiology ; Dental Cementum ; chemistry ; Humans ; Peptide Fragments ; Peptide Mapping ; methods ; Peptides ; physiology ; Protein Engineering ; methods ; Sequence Homology, Amino Acid ; Tissue Engineering ; methods ; Tooth Calcification ; physiology

BACKGROUND: It is not known how cardiac functions are affected during anaphylaxis. OBJECTIVE: Our aim was to measure the cardiac functions shortly after an anaphylaxis attack using a new technique that detects subclinical left ventricular dysfunction. METHODS: Patients in our hospital who experienced anaphylaxis and urticaria (control group) due to any cause were included in the study. Tryptase levels were measured on the third hour of the reaction and 6 weeks later. Left ventricular systolic functions were evaluated with global strain measurement using echocardiography, approximately 4 hours and 6-week post reaction. RESULTS: Twelve patients were included in the anaphylaxis group (83.3% female; mean age, 43.25 ± 9.9 years). The causes of anaphylaxis were drug ingestion (n = 11) and venom immunotherapy. Eight of the anaphylactic reactions (66.7%) were severe and in 9 reactions (75%) tryptase levels increased. In the anaphylaxis group, strain values measured shortly after anaphylaxis were significantly lower than those calculated 6 weeks later (p < 0.001) and tryptase levels significantly increased (p = 0.002). The strain values measured both shortly after anaphylaxis and 6 weeks later did not differ according to severity of anaphylaxis. In severe anaphylaxis, tryptase levels during anaphylaxis and 6 weeks later were significantly higher (p = 0.019, p = 0.035). The control group evidenced no differences regarding strain and tryptase levels measured at reaction and 6 weeks later. At reaction, in the anaphylaxis group, the tryptase levels were higher and the strain values were lower than those in the urticaria group (p = 0.007, p = 0.003). CONCLUSION: Cardiac dysfunction may develop during an anaphylaxis independent of severity of reaction.
Anaphylaxis ; Eating ; Echocardiography ; Female ; Humans ; Immunotherapy ; Tryptases ; Urticaria ; Venoms ; Ventricular Dysfunction, Left