Rat model of polymicrobial infection, immunity, and alveolar bone resorption in periodontal disease

One of the predominant polymicrobial infections of humans is expressed clinically as periodontal disease. Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia have been strongly implicated as members of a pathogenic consortium in the etiology of adult periodontitis. In this study we hypothesized that P. gingivalis, T. denticola, and T. forsythia are synergistic in terms of virulence potential and induce chronic periodontal inflammation that leads to alveolar bone resorption in a polymicrobial infection in rats. Groups of rats were infected with either P. gingivalis, T. denticola, or T. forsythia in monomicrobial infections or with all three species in polymicrobial oral infections with or without Fusobacterium nucleatum. PCR analyses of oral microbial samples demonstrated that rats infected with one bacterium were orally colonized by each of the bacteria during the study interval, and increased serum immunoglobulin G (IgG) antibody levels substantiated the interaction of the host with the infecting bacteria. PCR analyses of the rats with polymicrobial infections demonstrated that most rats were infected with P. gingivalis, T. denticola, and T. forsythia as a consortium. Furthermore, all rats exhibited a significant increase in the level of IgG antibody to the polymicrobial consortium. Radiographic measurement of alveolar bone resorption showed that rats infected with the polymicrobial consortium with or without F. nucleatum exhibited significantly increased alveolar bone resorption compared to the resorption in uninfected control rats, as well as the resorption in rats infected with one of the microbes. These results documented that P. gingivalis, T. denticola, and T. forsythia not only exist as a consortium that is associated with chronic periodontitis but also exhibit synergistic virulence resulting in the immunoinflammatory bone resorption characteristic of periodontitis.     

Benzothiazole appended 2,2′-(1,4-phenylene)diacetonitrile for the colorimetric and fluorescence detection of cyanide ions

A benzothiazole appended 2,2′-(1,4-phenylene)diacetonitrile derivative (2Z,2′Z)-2,2′-(1,4-phenylene)bis(3-(3-(benzo[d]thiazol-2-yl)-4-hydroxyphenyl)acrylonitrile) (PDBT) has been synthesized and investigated as a novel sensor, capable of showing high selectivity and sensitivity towards CN⁻ over a wide range of other interfering anions. After reaction with CN⁻, PDBT shows a new absorption peak at 451 nm with a color transformation from colorless to reddish-brown. When yellow fluorescent PDBT is exposed to CN⁻, it displays a significant increase in fluorescence at 445 nm, resulting in strong sky-blue fluorescence emission. The nucleophilic addition reaction of CN⁻ plays a role in the sensing mechanism of PDBT to CN⁻. PDBT can distinguish between a broad variety of interfering anions and CN⁻ with remarkable selectivity and sensitivity. Furthermore, the detection limit of the PDBT probe for CN⁻ is 0.62 μM, which is significantly lower than the WHO standard of 1.9 μM for drinking water. Density functional theory simulations corroborated the observed fluorescence changes and the internal charge transfer process that occurs after cyanide ion addition. In addition, real-time applications of PDBT, such as cell imaging investigations and the detection of CN⁻ in water samples, were successfully carried out.

(2Z,2′Z)-2,2′-(1,4-Phenylene)bis(3-(3-(benzo[d]thiazol-2-yl)-4-hydroxyphenyl)acrylonitrile) (PDBT) has been synthesized and investigated as a novel PDBT, capable of showing high selectivity and sensitivity towards CN⁻ over a wide range of other interfering anions.     

Prostaglandin E2 receptors have differential effects on Leishmania major infection

Through their receptors, prostaglandins play crucial roles in various infections. Although prostaglandin E₂ (PGE₂) is implicated as a susceptibility factor in Leishmania infection, the relative contributions of its four receptors – EP1, EP2, EP3 and EP4 – to this infection remain unknown. We report that Leishmania major infection of BALB/c‐derived peritoneal macrophages up‐regulated EP1 and EP3 expressions but down‐regulated EP2 and EP4 expressions. EP2 and EP4 agonists reduced parasite load, but EP1 and EP3 agonists increased parasite load in macrophages in vitro. Agonists of EP2 and EP4, antagonists of EP1 and EP3, or lentivirally expressed EP1‐shRNA and EP3‐shRNA significantly reduced parasite burden in susceptible BALB/c mice. These novel data suggest differential regulation and counteractive functions of EP receptor subsets.     

MicroRNAs from urinary extracellular vesicles are non-invasive early biomarkers of diabetic nephropathy in type 2 diabetes patients with the ‘Asian Indian phenotype’

AimsMicroRNAs (miRNAs) from extracellular vesicles (EVs) have been proposed as promising biomarkers for a number of diseases. In this study, their potential as urine-based biomarkers of diabetic nephropathy (DN) was assessed.MethodsMiRNAs were profiled in urinary EVs from 160 fasting subjects with normal glucose tolerance (NGT) and in T2DM patients with either microalbumininuria (MIC) or macroalbuminuria (MAC).ResultsA total of 73 miRNAs detected in urinary EVs (NGT) were predicted to target important functions for kidney homoeostasis, thereby validating their use as indicators of kidney dysfunction. Indeed, a urinary EV miRNA signature was found to comprise increased levels of let-7i-3p, miR-24-3p and miR-27b-3p, and decreased levels of miR-15b-5p, to identify patients with MIC. ROC curve analysis confirmed this ability to identify MIC in normo-albuminuria T2DM (T2DM-NA) patients and to differentiate between MAC and T2DM patients. These miRNAs were also predicted to target protein networks involved in the Wnt/β-catenin signalling cascade, activin receptor signalling and cell differentiation/proliferation, and correlated with eGRF, HbA_1c, serum creatinine, urea, albumin and blood pressure. Concentrations of miR-30a-5p were specifically modified in urinary EVs from patients with MAC, but not MIC, suggesting that miR-30a-5p could be related to severe kidney damage.ConclusionUrinary EV miRNAs correlate with the degree of MIC. As they are also thought to regulate pathways that are targets of pharmacological agents to prevent DN (reticulum stress, activin receptors), they may also serve as non-invasive ‘liquid biopsies’ to stratify patients at risk of developing MAC and to monitor treatment efficacy.