p21 Improving Osteoarthritis by Regulating the Pyroptosis of Cartilage Cells.

Background: The regulation of p21 in the pyroptosis of cartilage cells still needs to be further clarified. We aimed to explore the regulation of p21 on the pyroptosis of cartilage cells and to reveal the improvement of osteoarthritis. Methods: Chondrocytes were collected and isolated from patients with osteoarthritis (average age 58.64 ± 4.32) in Xuzhou Third People's Hospital, China in 2019, and healthy volunteers (average age 58.23 ± 3.91) were enrolled as the control group. mRNA expression levels of p21 and pyroptosis-related proteins (NLRP3, ASC, total caspase1 and cleaved-Caspase1) were detected by Western blot and real-time PCR. Cell activity, total number of cells and number of dead cells were calculated with CCK-8, MTT. And the regulation of p21 on the pyroptosis of cartilage cells was verified with overexpression and knockdown of p21 in cartilage cells. Results: In cartilage cells of patients with osteoarthritis, the transcription and translation levels of pyrolysis-related genes (NLRP3, cleaved-caspase 1, and ASC) significantly increased (P<0.01). p21 expression was up-regulated and positively correlated with the changing trend of pyrolysis-related proteins (P<0.01). Overexpressing p21 genes in normal cartilage cells significantly increased the expression of pyrolysis-related proteins (P<0.01). Conclusion: The pyroptosis of cartilage cells is causally related to the process of osteoarthritis, and can be regulated by transcription factor p21, which is a potential therapeutic target for osteoarthritis.

Circular RNA CircDHRS3 Aggravates IL-1ß-induced ECM Degradation, Apoptosis, and Inflammatory Response via Mediating MECP2 Expression.

Previous studies have reported that circular RNA hsa_circ_0010024 (circDHRS3), microRNA (miR)-193a-3p, and Methyl CpG binding protein 2 (MECP2) are unconventionally expressed in osteoarthritis (OA) cartilage samples. However, the regulatory mechanisms among circDHRS3, miR-193a-3p, and MECP2 in OA pathogenesis are unclear. Changes of circDHRS3, miR-193a-3p, and MECP2 mRNA were detected by qRT-PCR. Several protein levels were evaluated using western blotting. Cell proliferation was analyzed by 5-Ethynyl-2'-deoxyuridine (EdU) and cell counting assays. Cell apoptosis was determined by flow cytometry assay. Detection of pro-inflammatory cytokines was conducted using ELISA. The relationship between circDHRS3 or MECP2 and miR-193a-3p was validated by dual-luciferase reporter assay. We verified that circDHRS3 and MECP2 were overexpressed in OA cartilage samples, whereas miR-193a-3p was downregulated. CircDHRS3 silencing weakened IL-1ß-induced chondrocyte cartilage extracellular matrix (ECM) degradation, apoptosis, and inflammatory response. CircDHRS3 adsorbed miR-193a-3p to modulate MECP2 expression. Also, silencing of miR-193a-3p impaired circDHRS3 silencing-mediated suppression on IL-1ß-induced chondrocyte injury. Also, MECP2 overexpression alleviated miR-193a-3p mimic-mediated inhibition on IL-1ß-prompted chondrocyte injury. CircDHRS3 silencing reduced MECP2 expression via sponging miR-193a-3p, thereby weakening IL-1ß-induced chondrocyte ECM degradation, apoptosis, and inflammatory response.

Circ_SPG11 plays contributing effects on IL-1ß-induced chondrocyte apoptosis and ECM degradation via miR-665 inhibition-mediated GREM1 upregulation.

The dysregulation of circular RNA (circRNA) has been monitored in osteoarthritis (OA) cartilage, hinting that circRNA deregulation modulates OA progression. We thus aimed to unveil the role of circRNA spastic paraplegia 11 (circ_SPG11) in OA conditions. The upregulation of circ_SPG11 was observed in OA cartilage and IL-1ß-treated chondrocytes. Knockdown of circ_SPG11 restored IL-1ß-depleted cell proliferation and alleviated IL-1ß-induced cell apoptosis and ECM degradation. Circ_SPG11 bound to miR-665 and negatively regulated miR-665 expression. Inhibition of miR-665 reversed the inhibitory effect on IL-1ß-induced chondrocyte injury caused by circ_SPG11 knockdown. GREM1 was a target of miR-665, and circ_SPG11 knockdown depleted GREM1 expression by enriching miR-665. Overexpression of GREM1 also reversed the inhibitory effect on IL-1ß-induced chondrocyte injury caused by miR-665 enrichment. Circ_SPG11 might promote IL-1ß-induced chondrocyte apoptosis and ECM degradation via increasing GREM1 expression by decoying miR-665.

Effects of BMP-2 compound with fibrin on osteoporotic vertebral fracture healing in rats.

OBJECTIVES: To investigate the effects of bone morphogenetic protein-2 (BMP-2) compound with fibrin on osteoporotic vertebral fracture healing in rats. METHODS: For the present study 160 Specific-Pathogen Free 32-week-old female Sprague-Dawley rats were used. 120 rats were randomly divided in three groups (experimental, model and sham operation group- n=40 per group) and were ovariectomized to establish the osteoporosis model. 40 rats served as a control group without treatment. The expression of BMP-2 in the fracture zone at the 4th, 6th, 8th, and 12th weeks was detected by qRT-PCR. The expression of BALP and CTX-I in serum at the 12th week was detected by Elisa. RESULTS: At week 8, the morphology of the sham operation group was the same and the fracture healing occurred more slowly than in the other groups. At week 12, the expression of BMP-2 in the model group was significantly higher than that in the other three groups (p<0.05). At week 12, the maximum load, maximum strain, and elastic modulus of model group were significantly lower than those of the other three groups. CONCLUSIONS: BMP-2 compound with fibrin can enhance the timing and quality of bone fracture healing in rats.

Comparison of the clinical effect of DHS and PFNA on senile osteoporotic fracture and their significance of changes in BALP expression level.

OBJECTIVE: To investigate the clinical effects of dynamic hip screw (DHS) and proximal femoral nail anti-rotation (PFNA) on senile osteoporosis patients and their effects on the expression level of bone-specific alkaline phosphatase (BALP). METHODS: 116 elderly patients with osteoporotic fracture were divided into DHS group (n=67) and PFNA group (n=49). BALP values were measured by ELISA before operation and 30 days after operation. RESULTS: The operation time, the bleeding volume, and the weight-bearing time of PFNA group was shorter than DHS group (p<0.05); the dominant blood loss and occult blood loss in PFNA group were less than those in DHS group (p<0.05); the healing time and detumescence time, the complications of PFNA group was fewer than the DHS group (p<0.05). The ten-meter walking speed and the five sitting tests in PFNA group were shorter than that in DHS group (p<0.05); the excellent and good rate and Harris score in PFNA group were higher than those in DHS group (p<0.05). The expression of BALP in PFNA group was lower than that in DHS group (p<0.05). CONCLUSION: PFNA surgery has less trauma, fewer complications, more optimistic postoperative healing and recovery degree, and is more conducive to the reduction of BALP expression level.

Effects of hip replacement combined with alendronate sodium on postoperative healing of osteoporotic femoral neck fracture and levels of CTX-1 and BALP in patients.

This study aimed to explore the improvement of hip replacement combined with alendronate sodium on the condition of patients with osteoporotic femoral neck fracture and factors affecting the efficacy of patients. In total, 140 patients with femoral neck fracture from July 2015 to October 2017 in the Affiliated Xuzhou Hospital of Jiangsu University were collected. Of these, 61 patients were treated with hip replacement as the control group and 79 patients were treated with alendronate sodium as the observation group on the basis of the control group. ELISA was used to detect levels of carboxy-terminal opeptide of type I collagen (CTX-I) and bone alkaline phosphatase (BALP) in serum of patients before and after treatment. Harris score was used to compare the clinical efficacy of patients after treatment. Changes in the expression of CTX-I and BALP before and after treatment were compared between the two groups, and the correlation between CTX-I and BALP levels and Harris score was analyzed. According to the clinical efficacy of patients, the two groups were divided into the significant effect group and poor effect group. Risk factors affecting the efficacy of patients were analyzed, and the ROC of subjects with risk factors was drawn. After treatment, the expression of BALP in serum increased significantly compared with that before treatment, and the expression of CTX-I decreased significantly. After treatment, the expression of BALP in serum in the observation group was significantly higher than that in the control group (P<0.05). Multivariate analysis revealed that age, time of operation, CTX-I after treatment and BALP after treatment were independent risk factors affecting the efficacy of patients. In conclusion, hip replacement combined with alendronate sodium can effectively improve the clinical efficacy of patients, and age, time of operation, CTX-I after treatment and BALP after treatment are found to be independent risk factors affecting the postoperative efficacy of patients.

Salvianolic acid A ameliorates the integrity of blood-spinal cord barrier via miR-101/Cul3/Nrf2/HO-1 signaling pathway.

Salvianolic acid A (Sal A), a bioactive compound isolated from the Chinese medicinal herb Danshen, is used for the prevention and treatment of cardiovascular diseases. However, the protective function of Sal A on preserving the role of blood-spinal cord barrier (BSCB) after spinal cord injury (SCI) is unclear. The present study investigated the effects and mechanisms of Sal A (2.5, 5, 10mg/kg, i.p.) on BSCB permeability at different time-points after compressive SCI in rats. Compared to the SCI group, treatment with Sal A decreased the content of the Evans blue in the spinal cord tissue at 24h post-SCI. The expression levels of tight junction proteins and HO-1 were remarkably increased, and that of p-caveolin-1 protein was greatly decreased after SCI Sal A. The effect of Sal A on the expression level of ZO-1, occluding, and p-caveolin-1 after SCI was blocked by the HO-1 inhibitor, zinc protoporphyrin IX (ZnPP). Also, Sal A inhibited the level of apoptosis-related proteins and improved the motor function until 21days after SCI. In addition, Sal A significantly increased the expression of microRNA-101 (miR-101) in the RBMECs under hypoxia. AntagomiR-101 markedly increased the RBMECs permeability and the expression of the Cul3 protein by targeting with 3'-UTR of its mRNA. The expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and HO-1 was significantly increased after agomiR-101 treatment. Therefore, Sal A could improve the recovery of neurological function after SCI, which could be correlated with the repair of BSCB integrity by the miR-101/Cul3/Nrf2/HO-1 signaling pathway.

Combining Bone Marrow Stromal Cells with Green Tea Polyphenols Attenuates the Blood-Spinal Cord Barrier Permeability in Rats with Compression Spinal Cord Injury.

This study was performed to investigate the effect of bone marrow stromal cells (BMSCs) combined with green tea polyphenols (GTPs) on the blood-spinal cord barrier (BSCB) permeability after spinal cord injury (SCI) in the rat model. In the model of SCI rats, we found that the water content and the BSCB permeability were decreased by BMSCs and GTPs treatment, and their combination had a synergistic effect. Further, the motor function of rats was also greatly improved by BMSCs and GTPs administration. After treated by the combination of BMSCs and GTPs, SCI rats showed the up-regulated expression of tight junction (TJ) associated proteins claudin-5, occludin and ZO-1 by Western blot, which was more remarkable than that in the single treatment. The increased expression levels of claudin-5, occludin, and ZO-1 were the most obvious in the spinal cord microvessels using immunohistochemistry assay. This led to the conclusion that the combination of BMSCs and GTPs could decrease the BSCB permeability by up-regulating protein expression levels of claudin-5, occludin, and ZO-1. In addition, after BMSCs and GTPs administration, the results of Western blot and enzyme-linked immunosorbent assay (ELISA) revealed a significant decrease in protein expression level and the activation of nuclear factor-кB (NF-кB) p65. Our results indicated that combination of BMSCs and GTPs could improve motor function after SCI, which might be correlated with improvements in BSCB integrity, and that NF-кB might be involved in the modulating process.