The role of extracellular vesicle miRNAs and tRNAs in synovial fibroblast senescence

Extracellular vesicles are mediators of intercellular communication with critical roles in cellular senescence and ageing. In arthritis, senescence is linked to the activation of a pro-inflammatory phenotype contributing to chronic arthritis pathogenesis. We hypothesised that senescent osteoarthritic synovial fibroblasts induce senescence and a pro-inflammatory phenotype in non-senescent osteoarthritic fibroblasts, mediated through extracellular vesicle cargo. Small RNA-sequencing and mass spectrometry proteomics were performed on extracellular vesicles isolated from the secretome of non-senescent and irradiation-induced senescent synovial fibroblasts. β-galactosidase staining confirmed senescence in SFs. RNA sequencing identified 17 differentially expressed miRNAs, 11 lncRNAs, 14 tRNAs and one snoRNA and, 21 differentially abundant proteins were identified by mass spectrometry. Bioinformatics analysis of miRNAs identified fibrosis, cell proliferation, autophagy, and cell cycle as significant pathways, tRNA analysis was enriched for signaling pathways including FGF, PI3K/AKT and MAPK, whilst protein analysis identified PAX3-FOXO1, MYC and TFGB1 as enriched upstream regulators involved in senescence and cell cycle arrest. Finally, treatment of non-senescent synovial fibroblasts with senescent extracellular vesicles confirmed the bystander effect, inducing senescence in non-senescent cells potentially through down regulation of NF-κβ and cAMP response element signaling pathways thus supporting our hypothesis. Understanding the exact composition of EV-derived small RNAs of senescent cells in this way will inform our understanding of their roles in inflammation, intercellular communication, and as active molecules in the senescence bystander effect

Assessment of perineal scars on translabial pelvic floor ultrasound : a pilot study

Objective: We aimed to describe a method for identifying and evaluating perineal scars using translabial pelvic floor ultrasound. We hypothesized that translabial ultrasound can identify a perineal scar and can differentiate episiotomies from spontaneous tears. Methods: This pilot study is a secondary analysis of data obtained in the Epi-No® trial. Perineal integrity was assessed using volumes acquired on pelvic floor muscle contraction according to the method previously described for anal sphincter imaging. A scar was diagnosed if a hypoechoic distortion in the perineum was noted. We postulated that an episiotomy would result in a linear scar visible on four dimensional translabial ultrasound whereas nonlinear scars were considered the result of spontaneous perineal tear of grade 2 or higher. The results of this assessment were compared with data retrieved from electronic medical records. Results: A scar was identified in 79/120 women (66%): 42 (35%) linear and 37 (31%) nonlinear. Sonographic and clinical diagnosis agreed on the presence or absence of perineal trauma in 66%. Agreement for the type of laceration was 50%. Conclusion: In this retrospective pilot study, a blinded assessment of translabial ultrasound volume data showed agreement between clinical data and sonographic assessment of perineal integrity in 66% and of type of laceration in 50%. More work is needed to optimize the method in assessment of perineal scars to improve its performance before it can be used in clinical audit and research