Background: Porphyromonas gingivalis (Pg), a periodontal pathogen, has interstrain variability in virulence. The aim of this study is to determine the contribution of the cell invasion ability and proteolytic activity of Pg to its virulence in a murine model of periodontitis.
Methods: Three clinical isolates: KUMC-P1 (P1: low cell invasion ability and low proteolytic activity); KUMC-P4 (P4: low cell invasion ability and high proteolytic activity); and KUMC-P8 (P8: high cell invasion ability and low proteolytic activity), were orally administered into mice. Alveolar bone loss (ABL) and bacterial invasion of gingival tissues were measured. Additionally, effects of the three strains on transepithelial electrical resistance (TER) and the levels of tight-junction proteins in gingival epithelial cells were evaluated in vitro.
Results: ABL induced by the three strains was in the sequence P4 > P8 > P1, and the difference between P8 and P1 was not significant. Amounts of Pg detected within the gingival tissues were increased by all three strains compared with the sham group, and bacterial level was positively correlated with ABL. In vitro, P4 had a greater effect than the other strains on epithelial barrier disruption, as evidenced by the reduced levels of tight-junction proteins and TER.
Conclusion: The proteolytic activity of Pg was more critical than the cell invasion ability for inducing experimental periodontitis in mice, which could be attributed to the paracellular pathway dependence of gingival tissue invasion by bacteria in the mice.
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http://dx.doi.org/10.1902/jop.2016.160262 | DOI Listing |
Pharmaceuticals (Basel)
January 2025
Laboratory of Toxinology and Cardiovascular Research, University of Western São Paulo (UNOESTE), Presidente Prudente 19050-680, SP, Brazil.
We compared the enzymatic, coagulant, and neuromuscular activities of two variants (yellow-CDRy and white-CDRw) of venom with a sample of (CDT) venom and examined their neutralization by antivenom against CDT venom. The venoms were screened for enzymatic and coagulant activities using standard assays, and electrophoretic profiles were compared by SDS-PAGE. Neutralization was assessed by preincubating venoms with crotalic antivenom and assaying the residual activity.
View Article and Find Full Text PDFMolecules
January 2025
Dipartimento di Chimica, Università di Pavia, Via Taramelli 12, 27100 Pavia, Italy.
Spontaneous cleavage reactions normally occur in vivo on amino acid peptide backbones, leading to fragmentation products that can have different physiological roles and toxicity, particularly when the substrate of the hydrolytic processes are neuronal peptides and proteins highly related to neurodegeneration. We report a hydrolytic study performed with the HPLC-MS technique at different temperatures (4 °C and 37 °C) on peptide fragments of different neuronal proteins (amyloid-β, tau, and α-synuclein) in physiological conditions in the presence of Cu and Zn ions, two metal ions found at millimolar concentrations in amyloid plaques. The coordination of these metal ions with these peptides significantly protects their backbones toward hydrolytic degradation, preserving the entire sequences over two weeks in solution, while the free peptides in the same buffer are fully fragmented after the same or even shorter incubation period.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Department of Experimental Medicine, University of Salento, Via Provinciale Lecce-Monteroni n. 165, 73100 Lecce, Italy.
Peripherin belongs to heterogeneous class III of intermediate filaments, and it is the only intermediate filament protein selectively expressed in the neurons of the peripheral nervous system. It has been previously discovered that peripherin interacts with proteins important for the endo-lysosomal system and for the transport to late endosomes and lysosomes, such as RAB7A and AP-3, although little is known about its role in the endocytic pathway. Here, we show that peripherin silencing affects lysosomal abundance but also positioning, causing the redistribution of lysosomes from the perinuclear area to the cell periphery.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Biophysics and Biotechnology Department, Voronezh State University, 1 Universitetskaya Square, 394018 Voronezh, Russia.
This study explores various methods for the covalent immobilization of cysteine proteases (ficin, papain, and bromelain). Covalent immobilization involves the formation of covalent bonds between the enzyme and a carrier or between enzyme molecules themselves without a carrier using a crosslinking agent. This process enhances the stability of the enzyme and allows for the creation of preparations with specific and controlled properties.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Laboratorio de Biología de la Reproducción, Departamento Biomédico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta 1240000, Chile.
Proteasome-mediated protein degradation is essential for maintaining cellular homeostasis, particularly during spermatogenesis, where extensive cellular transformations, such as spermatid differentiation, require precise protein turnover. A key player in this process is the ubiquitin-proteasome system (UPS). This study aimed to investigate proteasome enzymatic activity at different stages of the spermatogenic cycle within the seminiferous tubules of mice and explore the regulatory mechanisms that influence its proteolytic function.
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