Exosomal U2AF2 derived from human bone marrow mesenchymal stem cells attenuates the intervertebral disc degeneration through circ_0036763/miR-583/ACAN axis.

Intervertebral disc degeneration (IDD) is one of the major leading causes of back pain affecting the patient's quality of life. However, the roles of circular RNA (circRNA) in IDD remains unclear. This study aimed to explore the function and underlying mechanism of circ_0036763 in IDD. In this study, expressions of circ_0036763, U2 small nuclear RNA auxiliary factor 2 (U2AF2), miR-583 and aggrecan (ACAN) in primary human nucleus pulposus cells (HNPCs) derived from IDD patients and healthy controls were detected by quantitative real-time reverse transcription-PCR (qRT-PCR) or Western blot (WB). The relationship between pre-circ_0036763 and U2AF2, circ_0036763 and miR-583, miR-583 and ACAN mRNA was determined by bioinformatic analysis, miRNA pull down or RNA immunoprecipitation (RIP) assay. The expressions of Collagen I and Collagen II were evaluated by WB. Co-culture of bone marrow mesenchymal stem cells (bMSCs) or bMSCs-derived exosomes and HNPCs were performed to identify the effect of U2AF2 on the mature of circ_0036763 and ACAN. Results indicated that circ_0036763, U2AF2 and ACAN were downregulated while miR-583 was upregulated in HNPCs derived from IDD patients compared with that in normal HNPCs. Besides, overexpression of circ_0036763 elevated the expressions of ACAN and Collagen II whereas reduced Collagen I expression in HNPCs. Moreover, U2AF2 promoted the mature of circ_0036763, and circ_0036763 positively regulated ACAN by directly sponging miR-583. Furthermore, exosomal U2AF2 derived from bMSCs could increase U2AF2 levels in HNPCs and subsequently regulate the expression of ACAN by circ_0036763/miR-583 axis. In summary, circ_0036763 modified by exosomal U2AF2 derived from bMSCs alleviated IDD through regulating miR-583/ACAN axis in HNPCs. Thus, this study might provide novel therapeutic targets for IDD.

Evaluation of Cartilaginous Endplate Degeneration Based on Magnetic Resonance Imaging.

In order to carry out the evaluation of cartilaginous endplate degeneration based on magnetic resonance imaging (MRI), this paper retrospectively analyzed the MRI data from 120 cases of patients who were diagnosed as lumbar intervertebral disc degeneration and underwent MRI examinations in the designated hospital of this study from June 2018 to June 2020. All cases underwent conventional sagittal and transverse T1WI and T2WI scans, and some cases were added with sagittal fat-suppression T2WI scans; then, the number of degenerative cartilaginous endplates and its ratio to degenerative lumbar intervertebral discs were counted and calculated, and the T1WI and T2WI signal characteristics of each degenerative cartilage endplate and its correlation with cartilaginous endplate degeneration were summarized, compared, and analyzed to evaluate the cartilaginous endplate degeneration by those magnetic resonance information. The study results show that there were 33 cases of cartilaginous endplate degeneration, accounting for 27.50% of all those 120 patients with lumbar intervertebral disc degeneration (54 degenerative endplates in total), including 9 cases with low T1WI and high T2WI signals, 5 cases with high T1WI and low T2WI signals, 12 cases with high and low mixed T1WI and high or mixed T2WI signals, and 4 cases with both low T1WI and T2WI signals. Therefore, MRI scanning can clearly present the abnormal signals of lumbar intervertebral disc and cartilaginous endplate degeneration, accurately identity their lesion locations, and type their degenerative characteristics, which may be best inspection method for the evaluation of cartilaginous endplate degeneration in the early diagnosis of intervertebral disc degeneration. The study results of this paper provide a reference for further researches on the evaluation of cartilaginous endplate degeneration based on magnetic resonance imaging.

Is Unilateral Percutaneous Kyphoplasty Superior to Bilateral Percutaneous Kyphoplasty for Osteoporotic Vertebral Compression Fractures? Evidence from a Systematic Review of Discordant Meta-Analyses.

BACKGROUND: Several meta-analyses have been performed to compare unilateral percutaneous kyphoplasty (PKP) and bilateral PKP in the treatment of osteoporotic vertebral compression fractures (OVCFs), but inconsistencies in the results have led to questions as to which technique is preferable. OBJECTIVE: This study was designed to clarify the benefits and disadvantages of unilateral PKP versus bilateral PKP as found in numerous discordant meta-analyses and thereby present surgical treatment recommendations for OVCFs considering the current best evidence. STUDY DESIGN: Systematic review/Meta-analysis. METHODS: Meta-analyses on unilateral and bilateral PKP for OVCFs were included by searching Pubmed, Embase, and Cochrane library. Meta-analysis quality was assessed using Oxford Levels of Evidence and Assessment of Multiple Systematic Reviews (AMSTAR). The Jadad decision algorithm was used to identify the best evidence. RESULTS: Eight eligible meta-analyses were included, 7 of which were Level-II evidence and one was Level-III evidence. The AMSTAR scores varied from 7 to 8. The Jadad decision algorithm suggested that the best meta-analysis should be selected depending upon publication characteristics and methodology of primary studies, language restrictions, and whether data analysis was performed on individual patients. The best available evidence indicated that both unilateral and bilateral PKP could receive similar good clinical and radiological outcomes. However, without increasing the risk of complications, unilateral PKP required shorter surgical time and less cement volume, offering better pain relief and quality of life at post-operative short term follow-ups. LIMITATIONS: Primary studies had defects in their methodologies. CONCLUSIONS: Unilateral PKP appears to be superior to bilateral PKP in the treatment of OVCFs. KEY WORDS: Osteoporotic vertebral compression fractures, percutaneous kyphoplasty, meta-analysis.