Sirtuin 7 (SIRT7) is a NAD+-dependent deacetylase in the sirtuin family. In a previous study, human bone marrow mesenchymal stem cells (hBMSCs) with reduced SIRT7 activity were developed to evaluate the effect of SIRT7 on osteogenesis. SIRT7 knockdown significantly enhanced osteoblast-specific gene expression, alkaline phosphatase activity, and mineral deposition in vitro. Additionally, SIRT7 knockdown upregulated β-catenin. The enhanced osteogenesis due to SIRT7 knockdown was partially rescued by a Wnt/β-catenin inhibitor. Furthermore, SIRT7 knockdown hBMSCs combined with a chitosan scaffold significantly promoted bone formation in a rat tibial defect model, as determined by imaging and histological examinations. These findings suggest that SIRT7 has an essential role in osteogenic differentiation of hBMSCs, partly by activation of the Wnt/β-catenin signaling pathway.

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Background Curcumin has been demonstrated to exert anti-oxidant, anti-fibrotic, anti-inflammatory, and anti-cancer activities. This study was conducted to observe the effect and inner mechanism of curcumin in rats with radiation-induced liver damage (RILD). Methods Thirty SD rats were classified into Control, Radiation group and Curcumin (Cur) + Radiation group (n = 10 in each group). The changes in body weight of the rats were observed on the 3rd, 7th and 14th days after the treatment with curcumin. On the 14th day post treatment, the heart blood of the rats was drawn for measurement of liver function indices including total protein (TP), alanine aminotransfetase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) as well as aspartate aminotransfetase (AST). Subsequently, the rats were euthanized and liver tissues were taken to observe liver morphological changes using hematoxylin-eosin (HE), and to analyze apoptosis condition using transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assays. Meanwhile, the oxidative stress level in liver tissue homogenate was determined by biochemical analysis. The expression of nuclear factor kappa B (NF-κB) pathway-associated and apoptosis-associated proteins was detected using Western blot analysis, and the expression levels of inflammatory factors were measured by Enzyme-linked immunosorbent assay (ELISA). Results The reduced body weight was observed in rats of the Radiation group compared to the Control and Cur + Radiation groups on day 14. In the Radiation group, hepatic cell edema and inflammatory cell infiltration could be visible under the light microscope, and the hepatocytes presented with vacuolar degeneration. In the Cur + Radiation group, the hepatocytes swelled under the microscope, but the pathological changes were alleviated in comparison with the Radiation group. RILD rats with curcumin treatment presented with decreased ALT, AST, ALP, LDH, and maleicdialdehyde (MDA) levels, and elevated TP, superoxide dismutase (SOD), caspase activated DNase (CAD) and glutathione (GSH) levels. Apoptosis and inflammation in rats with RILD were up-regulated, and the NF-κB pathway was activated, but they were reversed after continuously intragastric administration of curcumin for 14 days. Conclusion Our study highlights that curcumin treatment reduces the liver damage caused by radiation through the inhibition of the NF-κB pathway.

ObjectiveThe aim of this study was to evaluate our treatment algorithm and results in revision surgery of malunited tibial plateau fracture after failure of initial treatment.MethodsOur revision strategy was as follows: First, we determined the presence of any infection. Second, we determined whether the patient required total knee arthroplasty (TKA). Third, based on the characteristics of the tibial plateau fracture malunion, patients underwent one of the following surgical methods to achieve reduction: original fracture line osteotomy, tibial tubercle + original fracture line osteotomy, fibula head + original fracture line osteotomy, and metaphyseal open window reduction rod technique. The results was assessed with healing time, Rasmussen score, knee range of motion and complication rates.ResultsA total of 25 patients 16 men and 9 women; Mean age: 47.4 years (range: 35–63 years) underwent tibial plateau fracture revision operation. The time interval between the two surgeries was 2–24 months. The follow-up time was 12–30 months, and the operation time was 120–300 min. All patients received bone union at the last follow-up. The healing time was 3–6 months. The postoperative Rasmussen score was 19–29 (mean 23.8) compared with 14.4 points before the operation (p < 0.05). The postoperative knee joint activity was 60–110° (mean 95.0°), compared with 57.8° before the operation (p < 0.05). Six patients still had a 2-mm collapse on the articular surface, and 4 patients still had slight valgus (<5°). Except for 2 TKA cases, fracture reduction was excellent in 15 cases and good in 8 cases, with a good rate of 100%. Superficial wound infections occurred in 3 patients.ConclusionBecause revision of tibial plateau fracture malunion caused by failure of initial treatment is difficult, it is necessary to create a detailed surgical plan before the operation. Satisfactory clinical effects can be obtained if the correct revision strategy is used. The key to success is adopting a proper revision strategy according to the unique characteristics of the patient's tibial plateau fracture malunion.Level of EvidenceLevel IV, Therapeutic Study.