Single-cell and spatially resolved interactomics of tooth-associated keratinocytes in periodontitis.

Periodontitis affects billions of people worldwide. To address relationships of periodontal niche cell types and microbes in periodontitis, we generated an integrated single-cell RNA sequencing (scRNAseq) atlas of human periodontium (34-sample, 105918-cell), including sulcular and junctional keratinocytes (SK/JKs). SK/JKs displayed altered differentiation states and were enriched for effector cytokines in periodontitis. Single-cell metagenomics revealed 37 bacterial species with cell-specific tropism. Fluorescence in situ hybridization detected intracellular 16 S and mRNA signals of multiple species and correlated with SK/JK proinflammatory phenotypes in situ. Cell-cell communication analysis predicted keratinocyte-specific innate and adaptive immune interactions. Highly multiplexed immunofluorescence (33-antibody) revealed peri-epithelial immune foci, with innate cells often spatially constrained around JKs. Spatial phenotyping revealed immunosuppressed JK-microniches and SK-localized tertiary lymphoid structures in periodontitis. Here, we demonstrate impacts on and predicted interactomics of SK and JK cells in health and periodontitis, which requires further investigation to support precision periodontal interventions in states of chronic inflammation.

Feline Oral Squamous Cell Carcinoma: A Critical Review of Etiologic Factors.

Feline oral squamous cell carcinoma (FOSCC) is the most common oral neoplasia in cats. This malignant tumor is locally invasive, has a high mortality rate, and its etiology is not yet known. In humans, head and neck squamous cell carcinoma is associated with tobacco smoke, alcohol consumption, and human papillomavirus infection. Herein, a critical review about the potential etiologic factors of FOSCC was performed, considering publications between 2000 and 2022, aiming to synthesize all available scientific evidence regarding this issue. Recommendations of the PRISMA statement and the Cochrane Collaboration were followed and the PubMed database searched by using the MeSH terms MeSH terms "oral", "mouth", "lingual", "labial", "gingiva", "carcinoma", "squamous", and "feline". The selection process for eligible studies was based on specific inclusion and exclusion criteria and the quality of the studies assessed. The initial search resulted in 553 publications, with only 26 of these being included in the review. Sixteen studies were related to viral etiology and nine related to environmental factors such as exposure to tobacco smoke, ectoparasitic products, and the presence of oral comorbidities. When evaluated, feline papillomavirus was detected in 16.2% of samples of FOSCC. In the three studies focused on exposure to tobacco smoke, 35.2% (30/85) of cats with FOSCC had a history of this exposure. The consumption of canned food and the use of deworming collars were associated, in only one publication, with a risk of neoplasia increased by 4.7 and 5.3 times, respectively. Among 485 cats with FOSCC, 6.4% had dental and oral pathology (i.e., periodontal disease or feline chronic gingivostomatitis). The present study demonstrates that the available evidence on the etiology of FOSCC is still limited, however, there has been an increasing interest on this topic. To better understand the role of the possible etiological factors of this aggressive disease, and model for its human counterpart, large, prospective multi-institutional studies are needed.

Preparation of biological samples for microplastic identification by Nile Red.

Many methods have been used to isolate and identify microplastics from biological matrices. In biological samples, Nile Red can stain undigested residues, such as fats, soaps, and gels formed during organic matter removal, hindering the identification of fluorescent microplastics (≥2 µm). Thus, adjustments on sample preparation (e.g., fat removal) are required for the accurate identification of Nile Red stained microplastics. Multiples tests allowed to identify that digestion with 10% KOH at 60 °C for 24 h, followed by treatments with boiling water, acetone, and staining, produced good results in fourteen biological samples, including vertebrates and invertebrates. Digestion efficiencies were 94-100%, except for feces, which were 87%. Recovery rates of spiked microplastics were 97-100%, and few effects were observed in the infrared spectra and carbonyl index of seven polymers, with only the occasional yellowing suggesting surface changes. Filtration rates were improved by reducing the amount of sample. Small fluorescent microplastics could be identified in all samples under the microscope. Overall, the proposed method was efficient in removing natural organic matter from biological samples for Nile Red staining, requiring minimal sample handling, improving sample throughput, and allowing quantification of fluorescent microplastics in biological samples.

Worldwide contamination of fish with microplastics: A brief global overview.

Widespread contamination of microplastics may lead to internalization in fish. This literature review from March 2019 to March 2020 details that a median of 60% of fish, belonging to 198 species captured in 24 countries, contain microplastics in their organs. Carnivores species ingested more microplastics than omnivores. Only 14% of fish were from aquaculture. Most studies focused on digestive systems, with presence in other organs currently being insufficiently assessed. Based on this assessment, knowledge gaps that should be addressed in future studies were identified.