Improving the repair mechanism and miRNA expression profile of tibial defect in rats based on silent information regulator 7 protein analysis of mesenchymal stem cells.

The aim of this study was to verify the role of Silent Information Regulator 7 (SIRT7) in improving the repair mechanism of bone marrow mesenchymal stem cells (BMMSCs) and the expression of microribonucleic acid (miRNA). Human BMMSCs were extracted from patients with femoral fractures, and the proliferation activity of human BMMSCs before and after knockout SIRT7 and the expression levels of bone-related genes and proteins were compared. Thirty-two 8-week-old male Sprague-Dawley (SD) rats were randomly divided into a blank group, a chitosan scaffold group, a control group, and a silence information regulator knockout group 7 (n = 8). In addition to the blank group, the chitosan scaffold, the green fluorescent protein (GFP) transfected stem cell composite chitosan scaffold, and the SIRT7 knockout stem cell composite chitosan scaffold were implanted in the other three groups, respectively. The X-rays and small animal in vivo three-dimensional tomography (Micro-CT) were adopted to quantitatively analyze the volume fraction, the number of trabeculae, and the connection density. Compared with the other three groups, the bone defect was formed more in the medullary mesenchymal stem cell knockout group, and the bone volume fraction, number of trabeculae and connection density were significantly increased (P < 0.05). MiR-98-5p can significantly promote the formation of bone molecules and bone structure in rats (P < 0.05). Human BMMSCs combined with chitosan scaffold can accelerate the repair of tibial defects. MiR-98-5p targeting and regulating bone formation gene (CKIP-1) could significantly improve the process of osteogenesis in rats.

Circ-ATAD1 is overexpressed in osteosarcoma (OS) and suppresses the maturation of miR-154-5p to increase cell invasion and migration.

BACKGROUND: Circ-ATAD1 plays an oncogenic role in gastric cancer. However, its roles in other cancers are unclear. We aimed to analyze the role of circ-ATAD1 in osteosarcoma (OS). METHODS: The expression levels of circ-ATAD1, mature miR-154-5p, and premature miR-154-5p in paired OS and non-tumor tissues from 56 OS patients were determined using RT-qPCR. Nuclear fractionation assay was performed to analyze the subcellular location of circ-ATAD1. The interaction between circ-ATAD1 and premature miR-154-5p was analyzed using RNA pull-down assay. The role of circ-ATAD1 in regulating miR-154-5p maturation was analyzed using RT-qPCR in cells with overexpression. Transwell assays were performed to analyze the roles of circ-ATAD1 and miR-154-5p in regulating OS cell invasion and migration. RESULTS: Circ-ATAD1 was overexpressed in OS compared to non-tumor tissues and was detected in the nuclei of OS cells. Mature miR-154-5p, but not premature miR-154-5p, was downregulated in OS tissues compared to non-tumor tissues and was inversely correlated with circ-ATAD1. In OS cells, circ-ATAD1 overexpression decreased the expression of mature miR-154-5p, but not premature miR-154-5p. Transwell assay analysis showed that circ-ATAD1 overexpression increased cell invasion and migration, and mature miR-154-5p overexpression suppressed these cell behaviors. In addition, circ-ATAD1 overexpression reduced the effects of mature miR-154-5p overexpression on cell behaviors. CONCLUSIONS: Circ-ATAD1 is overexpressed in OS and suppresses miR-154-5p maturation to increase cell invasion and migration.

Involvement of increased expression of chemokine C-C motif chemokine 22 (CCL22)/CC chemokine receptor 4 (CCR4) in the inflammatory injury and cartilage degradation of chondrocytes.

CCL22, which could induce chondrocyte apoptosis, was identified to be overexpressed in damaged cartilage. This study was conducted with the aim of investigating the effects of CCL22 interference on chondrocyte injury. The osteoarthritis model was established by stimulating chondrocytes with LPS. The expressions of CCL22, CCR4, matrix metallopeptidase (MMP) 3, MMP9, MMP13, (a disintegrin and metalloproteinase with thrombospondin-like motifs) ADAMTS-4, collagen II and inflammatory cytokines were measured using quantitative reverse transcription PCR (RT-qPCR) and western blot. Besides, immunoprecipitation (IP) was employed to verify the binding of CCL22 and CCR4. After CCR4 was overexpressed, cell viability was observed using Cell Counting Kit-8 (CCK-8). Additionally, cell apoptosis as well as its related proteins was detected by TUNEL and western blot, respectively. ng What's more, glycosaminoglycan (GAG) level was detected using GAG kits. CCL22 and CCR4 expression increased noticeably in LPS-stimulated ATDC5 chondrocytes. CCL22 inhibition could suppress the expression of CCR4 in LPS-induced ATDC5 cells. Likewise, CCL22 inhibition could revive the activation of LPS-induced ATDC5 cells by regulating CCR4. In addition, CCL22 knockdown alleviated inflammatory response and cell apoptosis through CCR4. Furthermore, the cartilage degradation of ADTC5 cells could be relieved by CCL22 silence via regulating CCR4. CCL22/CCR4 expression was increased in osteoarthritic cartilage injury and participated in the inflammation and cartilage degradation of chondrocytes.

The exosomal transfer of human bone marrow mesenchymal stem cell-derived miR-1913 inhibits osteosarcoma progression by targeting NRSN2.

OBJECTIVE: Osteosarcoma is a malignant bone tumor consisting of mesenchymal cells. This study aimed to investigate the inhibitory effects of human bone marrow mesenchymal stem cell (hBMSC)-derived miR-1913 on osteosarcoma. METHODS: Cell viability was determined using CCK8 and colony formation assays. The cell migration and invasion abilities were assessed using wound healing and transwell assays. RT-qPCR and western blot were used to measure the miR-1913, Neurensin-2 (NRSN2), N-cadherin, and E-cadherin expression levels. Dual luciferase reporter assays were conducted to identify the target relationship between miR-1913 and NRSN2. The exosomes were extracted and identified using TEM and NTA assays. RESULTS: In the osteosarcoma tumor tissues and cell lines, the NRSN2 expressions were up-regulated, which correlated with a poor osteosarcoma prognosis. MiR-1913 inhibited the cell viability, proliferation, migration, and invasion by negatively targeting NRSN2. Furthermore, the hBMSC-derived exosomes delivered miR-1913 to inhibit the NRSN2 expression in the osteosarcoma cells. CONCLUSION: The inhibitory role of hBMSC-derived miR-1913 on osteosarcoma progression was achieved by targeting NRSN2, indicating the potential therapeutic value of hBMSC-derived miR-1913.

Effect of neutrophil-to-lymphocyte ratio on short-term prognosis of elderly patients with hip fracture.

OBJECTIVE: To investigate the effect of neutrophil-to-lymphocyte ratio (NLR) on short-term prognosis in elderly patients with hip fracture. METHODS: Altogether, 124 elderly patients with hip fractures who underwent surgery in our hospital were retrospectively studied, and they were divided into survival group (n=98) and death group (n=26) according to their 1-year survival. General data of both groups were collected and compared, and indicators with statistical differences in univariate analysis were further examined by logistic regression analysis. Venous blood samples were drawn from all patients 1 day after the surgery to detect and compare NLR, serum procalcitonin (PCT) and C-reactive protein (CRP) levels between both groups. ROC curve was used to analyze the clinical value of NLR in predicting the prognosis of patients. NLR cutoff value obtained by the ROC curve analysis was adopted to divide the patients into high and low ratio groups, and Kaplan-Meier (K-M) curves were used to assess the survival rate of patients in both groups. RESULTS: There were significant differences in age, gender, marital status, medical history and American Society of Anesthesiologists (ASA) grades between both groups. Logistic regression analysis showed that advanced age (≥85 years), male gender, and higher ASA grades (III-IV) were risk factors for short-term poor prognosis in elderly patients with hip fracture. Compared with survival group, NLR, PCT and CRP levels were higher in death group. ROC curve showed that the AUC of NLR predicting patients' prognosis was 0.804 at a cutoff value of 6.939%. K-M curves showed that the overall survival was lower in high-ratio group than in low-ratio group. CONCLUSION: Advanced age (overall survival was lower in high-ratio group than in low-ratio group), male gender, and higher ASA grades (III-IV) were risk factors for short-term poor prognosis in elderly patients with hip rifracture. NLR has some clinical value in predicting and evaluating the prognosis of patients.