Search

Aim: To reveal the cellular composition and molecular environment of the periodontal and peri‐implant inflammatory infiltrates through a single‐cell sequencing technique, which may explain the pathological difference between these two diseases. A special focus was placed on the phenotypes and potential roles of neutrophils and fibroblasts in peri‐implant/periodontal tissue immunity. Materials and Methods: High‐throughput single‐cell transcriptomic profiling of peri‐implant tissues from patients with peri‐implantitis as well as periodontal tissues from patients with periodontitis and healthy donors was performed. Immunofluorescence analysis was carried out to further validate the identified cell subtypes and their involvement in peri‐implantitis and periodontitis. Results: Based on our single‐cell resolution analysis, a quantified proportional increase of neutrophil (Neu) subtypes was shown in peri‐implantitis. Among these, a predominance of Neutro_CXCR2 was revealed. We also found the involvement of inflammation‐promoting fibroblasts as well as a predominance of CXCL8+ fibroblast–CXCR2+ neutrophil interaction in peri‐implantitis. Conclusions: Our study indicated that the predominance of CXCL8+ fibroblast–CXCR2+ neutrophil interaction might underline the enhanced host response in peri‐implantitis compared with periodontitis. This information offers a molecular basis by which fibroblast and neutrophil subtypes might be diagnostically and therapeutically targeted in peri‐implantitis. [ABSTRACT FROM AUTHOR]

Distant lung metastasis is the main factor that affects the survival rate of patients with salivary adenoid cystic carcinoma (SACC). Anoikis resistance is a feature of tumor cells that easily metastasize. The long non‐coding RNA (lncRNA) MRPL23 antisense RNA 1 (MPRL23‐AS1) is related to lung metastasis in SACC, but its role in anoikis resistance is unknown. After altering MPRL23‐AS1 expression in SACC cells, anoikis resistance was detected by calcein AM/PI staining and annexin V/PI flow cytometry. The apoptosis marker activated caspase‐3 and the bcl‐2/bax ratio were detected by Western blotting. The relationship between MPRL23‐AS1 and the promoter of the potential downstream target gene p19INK4D was identified by chromatin immunoprecipitation (ChIP)‐PCR assay. p19INK4D expression in patient tissues was determined using qRT‐PCR and immunohistochemistry. The functional experiments showed that MPRL23‐AS1 could promote anoikis resistance in vitro. MRPL23‐AS1 recruited the EZH2 to the promoter region of p19INK4D, inhibited p19INK4D expression, and promoted tumor cell anoikis resistance. p19INK4D overexpression did not affect anoikis in attached cells; however, it attenuated the anoikis resistance effect of MPRL23‐AS1 in suspension cells. p19INK4D expression was significantly lower in SACC tissues than in normal tissues. The novel MRPL23‐AS1/p19INK4D axis may be a potential SACC biomarker or therapeutic target. [ABSTRACT FROM AUTHOR]