Overexpression of RAD54L attenuates osteoarthritis by suppressing the HIF-1α/VEGF signaling pathway: Bioinformatics analysis and experimental validation.

Osteoarthritis (OA) is a widespread chronic, progressive, degenerative joint disease that causes pain and disability. Current treatments for OA have limited effectiveness and new biomarkers need to be identified. Bioinformatics analysis was conducted to explore differentially expressed genes and DNA repair/recombination protein 54 L (RAD54L) was selected. We firstly overexpressed RAD54L in interleukin-1ß (IL-1ß)-induced human articular chondrocytes or in OA rats to investigate its effect on OA. Chondrocyte viability and apoptotic rate were measured by Cell Counting Kit-8 and flow cytometry, respectively. Then we evaluated OA severity in vivo by Hematoxylin-eosin staining and Osteoarthritis Research Society International standards. The expression of inflammatory mediators was tested by enzyme-linked immunosorbent assay. Finally, western blot was performed to determine the relative expression level of hypoxia-inducible factors 1α (HIF-1α) and vascular endothelial growth factor (VEGF). Overexpression of RAD54L promoted cell viability and attenuated apoptosis in IL-1ß-induced human chondrocytes. A lower Osteoarthritis Research Society International score and a remarkable alleviation of chondrocyte disordering and infiltration of inflammatory cells were found in cartilage tissues of OA rats after overexpressing RAD54L. The inflammatory response induced by OA was decreased by RAD54L overexpression in vitro and in vivo. In addition, RAD54L overexpression decreased the relative expression level of HIF-1α and VEGF. Overexpression of RAD54L could attenuate OA by suppressing the HIF-1α/VEGF signaling pathway, indicating that RAD54L may be a potential treatment target for OA.

A Meta-Analysis of CT as a Tool for Diagnosing and Treating Shoulder Joint Bankart Injuries.

Objective: The shoulder joint is the most flexible joint in the human body. It is a typical multiaxial ball-and-socket joint. The humeral head is approximately spherical, and the glenoid is small and shallow. This article mainly discusses the application value of computerized tomography (CT) in the early diagnosis of skeletal Bankart injury of the shoulder joint. Methods: The chemical quality was evaluated according to the physical therapy evidence database PEDro scale. The literature quality evaluation scale and the NO scale are also used to evaluate the quality of each nonrandomized study. The standard quality scores of the literature quality evaluation scale are as follows: (1) the selection of the study group; (2) the comparability of the study group; and (3) (cohort study) clear interest results. Outcome measurement: Postoperative shoulder joint stability and range of motion (ROM) are the main results of Bankart injury patients undergoing open repair surgery and arthroscopic repair surgery. The secondary results of the survey included the Rowe score, the shoulder stability score, the American shoulder and elbow surgery score ASES, the University of California, Los Angeles, shoulder score UCLA, and the operation time. Results: Four of the included studies are randomized controlled trials, and the other studies are cohort studies. After meta-analysis, a fixed-effect model (I 2 = 34%) was used to observe the difference in shoulder stability treatment between the two groups and was statistically significant (P = 0.008, RR = 0.94, 95% confidence interval: 0.89~0.98). The analysis results showed that compared with patients undergoing open surgery, patients' undergoing arthroscopic repair had better postoperative shoulder motion range (P < 0.001, SMD = 0.47, 95% confidence interval: -0.72~0.22), and there is no significant heterogeneity. Conclusion: The Bankart injury of the shoulder joint cannot be diagnosed by X-ray examination alone due to its anatomical location and the size of the fracture fragments. CT examination has a better auxiliary diagnostic effect in the early stage of skeletal Bankart injury.

A Meta-Analysis of Systemic Evaluation of Knee Ligament Injury or Intervention of Knee Proprioceptive Function Recovery.

OBJECTIVE: The knee ligaments, as a passive knee joint stability device, provide protection for the knee joint and ensure its functional integrity. This role has long been known and recognized by people. The original purpose of knee ligament reconstruction after knee ligament injury is to restore its anatomical structure and mechanical stability mechanism. METHODS: Taking athletes as the research object, randomized controlled trials (RCTs) on improving ankle joint function of athletes related to proprioception training at home and abroad were included. The search time was from the establishment of the database to December 31, 2019, and the references of related documents were traced. Two researchers independently screened the literature, extracted data, and evaluated the quality of the literature. RevMan 5.3 software was used for data analysis. RESULTS: The extensor strength, flexor strength, and flexor strength/extensor strength of the affected limb were higher than before the operation one year after surgery (P < 0.01). The Lysholm score, Lysholm instability score, and one-foot jump distance were all higher than those before surgery (P < 0.05); the difference of KT-2000 for both knees was smaller than that before surgery (P < 0.05). CONCLUSION: In maintaining the anterior stability of the knee joint, the knee ligament provides 85% static resistance to prevent the tibia from moving forward, so knee ligament injury will cause knee instability. The proprioceptive feedback mechanism plays an important role in maintaining the functional stability of joints.

[EFFECT OF VITAMIN C ON APOPTOSIS OF NUCLEUS PULPOSUS CELLS INDUCED BY TUMOR NECROSIS FACTOR a AND SERUM DEPRIVATION].

OBJECTIVE: To explore the effect of Vitamin C (Vit C) on the apoptosis of human nucleus pulposus (NP) cells induced by tumor necrosis factor a (TNF-alpha) and serum deprivation. METHODS: The NP cells were isolated from patients undergoing spine corrective operation by collagenase trypsin. The experiment was divided into 3 groups: Vit C group (group A), TNF-alpha group (group B), and serum deprivation group (group C). Group A was reassigned to Al subgroup (basic medium), A2 subgroup (100 pg/mL Vit C), and A3 subgroup (200 pg/mL Vit C). Group B was reassigned to B0 subgroup (control group), Bi subgroup (100 ng/mL TNF-alpha), B2 subgroup (100 microg/mL Vit C+100 ng/mL TNF-alpha), and B3 subgroup (200 microg/mL Vit C+100 ng/mL TNF-alpha). Group C was reassigned to C0 subgroup (Control group), C1 subgroup (2% FBS), C2 subgroup (2% FBS+100 microg/mL Vit C), and C3 subgroup (2% FBS+200 microg/mL Vit C). After application of 100 pg/mL or 200 microg/mL Vit C for 24 hours, NP cells were stimulated by TNF-alpha and serum deprivation, then the apoptosis rate of NP cells was detected by a flow cytometry, and the gene expressions of the extracellular matrix of NP cells (collagen type I, collagen type II, aggrecan, and Sox9) and apoptosis related genes (p53, FAS, and Caspase 3) were detected by real-time fluoroscent quantitative PCR. Results Group A: Vit C could significantly reduce the apoptosis rate and gene expressions of p53, FAS, and Caspase 3 of NP cells in A2 and A3 subgroups when compared with Al subgroup (P<0.05), but there was no significant difference between A2 subgroup and A3 subgroup (P>0.05); Vit C could promote the expressions of the extracellular matrix (collagen type I, collagen type II, aggrecan, and Sox9) of NP cells in a concentration dependent manner (P<0.05). Group B: TNF-alpha significantly increased the apoptosis rate and the gene expressions of p53, FAS, and Caspase 3 in B1 subgroup when compared with B0 subgroup (P<0.05); however, Vit C significantly increased the apoptosis rate and the gene expressions in B2 subgroup, and significantly decreased them in B3 subgroup when compared with B1 subgroup (P<0.05). Group C: 2% FBS significantly increased the apoptosis rate of NP cells and significantly reduced the gene expressions of p53, FAS, and Caspase 3 in C1 subgroup when compared with C0 subgroup (P<0.05); Vit C could significantly reduce the apoptosis rate and gene expressions of p53, FAS, and Caspase 3 in C3 subgroup, but it could significantly increase them in C2 subgroup when compared with C1 subgroup (P<0.05). CONCLUSION: Vit C can promote the synthesis and secretion of extracellular matrix of NP cells. 200 microg/mL Vit C may delay the apoptosis induced by TNF-alpha and serum deprivation, indicating the potential therapeutic effect of Vit C on intervertebral disc degeneration.

Differential expression of extracellular-signal-regulated kinase 5 (ERK5) in normal and degenerated human nucleus pulposus tissues and cells.

Extracellular-signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family and regulates a wide variety of cellular processes such as proliferation, differentiation, necrosis, apoptosis and degeneration. However, the expression of ERK5 and its role in degenerated human nucleus pulposus (NP) is hitherto unknown. In this study, we observed the differential expression of ERK5 in normal and degenerated human nucleus pulposus tissues by using immunohistochemical staining and Western blot. Treatment of NP cells with Pro-inflammatory cytokine, TNF-α decreased ERK5 gene expression as well as NP marker gene expression; including the type II collagen and aggrecan. Suppression of ERK5 gene expression in NP cells by ERK5 siRNA resulted in decreased gene expression of type II collagen and aggrecan. Furthermore, inhibition of ERK5 activation by BIX02188 (5µM) decreased the gene expression of type II collagen and aggrecan in NP cells. Our results document the expression of ERK5 in degenerated nucleus pulposus tissues, and suggest a potential involvement of ERK5 in human degenerated nucleus pulposus.