Standard intraoral radiography vs. cone beam computed tomography for root canal systems detection in historical dental material

The study of root canal systems of historical teeth is relatively new in anthropological research. This issue has not been extensively documented in the anthropological literature. The authors of the present study have detected the visibility of root canal systems in 231 human teeth belonging to 11 individuals of both sexes from the 18th and 19th centuries in an archaeological site at Radom (Poland). Teeth were divided precisely into one-, two-, and three-rooted specimens. Each root was analyzed separately. Three methods were used: Cone Beam Computed Tomography (CBCT), Standard Intraoral Radiography in Paralleling Technique (PT), and Same Lingual Opposite Buccal (SLOB) technique with constant exposure conditions. It was found that CBCT can be used successfully, even treated as a “gold standard”, providing the highest visibility rate of all teeth types. In maxilla one-root teeth, the root canal is more visible in PT (77%) than in SLOB (54%) technique. In upper premolars, both buccal and palatal canals are more visible in SLOB (75% and 85%, respectively), and the differences are statistically significant (p = 0.0003 and p < 0.0001, respectively). In three-rooted teeth, the most visible canals are distobuccal, in both SLOB (80%) and PT (70%) methods. Less frequently diagnosed are canals in mesiobuccal roots in both radiographic methods (PT 20% and SLOB 32%). The canals in palatal root were poorly detectable. In mandibular one-root teeth, a higher visibility rate was achieved with PT (93%) than SLOB (80%) technique. In distal roots of mandibular molars, the canals are more visible in PT (59%) method. Morphology of mesial root was better detected in SLOB (74%) technique. The study demonstrates the potential of using single-root teeth when the rest of the tooth root is fragmented

Apoptotic cell clearance in chronic inflammation of lateral neck cysts

The mechanism driving accumulation of large numbers of apoptotic and necrotic neutrophils in inflamed lateral neck cysts (LNC), in the absence of infection, remains obscure. The cellular content of cysts obtained from 17 patients was co-cultured with human macrophages. Phagocytosis levels of cyst-derived neutrophils were determined and compared to the uptake of spontaneously apoptotic neutrophils. Simultaneously, the expression of cytokines in macrophages exposed to cyst contents was measured. In comparison to spontaneously apoptotic neutrophils, the phagocytosis of LNC-derived neutrophils by macrophages was inefficient. An inverse correlation between neutrophil content in LNC and their uptake was observed. Macrophages co-cultured with cyst contents responded with variable expression of IL-6, TNF-α and IL-10. The hindered clearance of apoptotic neutrophils in LNC may lead to secondary necrosis of these cells and stimulation of the inflammatory reaction. Together with local production of anti-inflammatory cytokines, this may fuel chronic inflammation in the cysts

Studies of Streptococcus anginosus Virulence in Dictyostelium discoideum and Galleria mellonella Models

For many years, Streptococcus anginosus has been considered a commensal colonizing the oral cavity, as well as the gastrointestinal and genitourinary tracts. However, recent epidemiological and clinical data designate this bacterium as an emerging opportunistic pathogen. Despite the reported pathogenicity of S. anginosus, the molecular mechanism underpinning its virulence is poorly described. Therefore, our goal was to develop and optimize efficient and simple infection models that can be applied to examine the virulence of S. anginosus and to study host-pathogen interactions. Using 23 S. anginosus isolates collected from different infections, including severe and superficial infections, as well as an attenuated strain devoid of CppA, we demonstrate for the first time that Dictyostelium discoideum is a suitable model for initial, fast, and large-scale screening of virulence. Furthermore, we found that another nonvertebrate animal model, Galleria mellonella, can be used to study the pathogenesis of S. anginosus infection, with an emphasis on the interactions between the pathogen and host innate immunity. Examining the profile of immune defense genes, including antimicrobial peptides, opsonins, regulators of nodulation, and inhibitors of proteases, by quantitative PCR (qPCR) we identified different immune response profiles depending on the S. anginosus strain. Using these models, we show that S. anginosus is resistant to the bactericidal activity of phagocytes, a phenomenon confirmed using human neutrophils. Notably, since we found that the data from these models corresponded to the clinical severity of infection, we propose their further application to studies of the virulence of S. anginosus

Inactive Gingipains from P. gingivalis Selectively Skews T Cells toward a Th17 Phenotype in an IL-6 Dependent Manner

Gingipain cysteine proteases are considered key virulence factors of Porphyromonas gingivalis. They significantly influence antibacterial and homeostatic functions of macrophages, neutrophils, the complement system, and cytokine networks. Recent data indicate the role of P. gingivalis in T cell differentiation;however, the involvement of gingipains in this process remains elusive. Therefore, the aim of this study was to investigate the contribution of danger signals triggered by the gingipains on the generation of Th17 cells, which play a key role in protection against bacterial diseases but may cause chronic inflammation and bone resorption. To this end we compared the effects of the wild-type strain of P. gingivalis (W83) with its isogenic mutant devoid of gingipain activity (Delta K Delta RAB), and bacterial cells pretreated with a highly-specific inhibitor of gingipains activity (KYTs). Antigen presenting cells (APCs), both professional (dendritic cells), and non-professional (gingival keratinocytes), exposed to viable bacteria expressed high amounts of cytokines (IL-6, IL-21, IL-23). These cytokines are reported to either stimulate or balance the Th17-dependent immune response. Surprisingly, cells infected with P. gingivalis devoid of gingipain activity showed increased levels of all tested cytokines compared to bacteria with fully active enzymes. The effect was dependent on both the reduction of cytokine proteolysis and the lack of cross-talk with other bacterial virulence factors, including LPS and fimbriae that induce de novo synthesis of cytokines. The profile of lymphocyte T differentiation from naive T cells showed enhanced generation of Th17 in response to bacteria with inactive gingipains. Moreover, we found that gingipain-dependent induction of Th17 cells was highly specific, since other T cell-subsets remained unchanged. Finally, inhibition of IL-6 signaling in dendritic cells led to a significant depletion of the Th17 population. Cumulatively, this study revealed a previously undisclosed role of gingipain activity in the process of Th17 differentiation reliant on blocking signaling through IL-6. Since inactivation of gingipains accelerates the skewing of T cells toward Th17 cells, which are detrimental in periodontitis, IL-6 signaling may serve as an attractive target for treatment of the disease

Aristolochic acid I determine the phenotype and activation of macrophages in acute and chronic kidney disease

Acute and chronic kidney injuries are multifactorial traits that involve various risk factors. Experimental animal models are crucial to unravel important aspects of injury and its pathophysiological mechanisms. Translating knowledge obtained from experimental approaches into clinically useful information is difficult;therefore, significant attention needs to be paid to experimental procedures that mimic human disease. Herein, we compared aristolochic acid I (AAI) acute and chronic kidney injury model with unilateral ischemic-reperfusion injury (uIRI), cisplatin (CP)- or folic acid (FA)-induced renal damage. The administration of AAI showed significant changes in serum creatinine and BUN upon CKD. The number of neutrophils and macrophages were highly increased as well as AAI-induced CKD characterized by loss of tubular epithelial cells and fibrosis. The in vitro and in vivo data indicated that macrophages play an important role in the pathogenesis of AA-induced nephropathy (AAN) associated with an excessive macrophage accumulation and an alternative activated macrophage phenotype. Taken together, we conclude that AA-induced injury represents a suitable and relatively easy model to induce acute and chronic kidney injury. Moreover, our data indicate that this model is appropriate and superior to study detailed questions associated with renal macrophage phenotypes

Permanent and reliable inactivation of Huntington's disease mutation via customized CRISPR/SaCas9 gene editing

Allele-specific CRISPR/SaCas9 gene editing therapy targeting the mutated HTT exon-1 would decrease the formation of mHTT aggregates reducing the neuronal dysfunction and striatum atrophy

Adhesive protein-mediated crosstalk between <i>Candida albicans</i> and <i>Porphyromonas gingivalis</i> in dual species biofilm protects the anaerobic bacterium in unfavorable oxic environment

Abstract The oral cavity contains different types of microbial species that colonize human host via extensive cell-to-cell interactions and biofilm formation. Candida albicans —a yeast-like fungus that inhabits mucosal surfaces—is also a significant colonizer of subgingival sites in patients with chronic periodontitis. It is notable however that one of the main infectious agents that causes periodontal disease is an anaerobic bacterium— Porphyromonas gingivalis. In our study, we evaluated the different strategies of both pathogens in the mutual colonization of an artificial surface and confirmed that a protective environment existed for P. gingivalis within developed fungal biofilm formed under oxic conditions where fungal cells grow mainly in their filamentous form i.e. hyphae. A direct physical contact between fungi and P. gingivalis was initiated via a modulation of gene expression for the major fungal cell surface adhesin Als3 and the aspartic proteases Sap6 and Sap9. Proteomic identification of the fungal surfaceome suggested also an involvement of the Mp65 adhesin and a “moonlighting” protein, enolase, as partners for the interaction with P. gingivalis. Using mutant strains of these bacteria that are defective in the production of the gingipains—the proteolytic enzymes that also harbor hemagglutinin domains—significant roles of these proteins in the formation of bacteria-protecting biofilm were clearly demonstrated