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Bone & Joint Research
Vol. 11, Issue 6 | Pages 386 - 397
22 Jun 2022
Zhu D Fang H Yu H Liu P Yang Q Luo P Zhang C Gao Y Chen Y

Aims. Alcoholism is a well-known detrimental factor in fracture healing. However, the underlying mechanism of alcohol-inhibited fracture healing remains poorly understood. Methods. MicroRNA (miR) sequencing was performed on bone mesenchymal stem cells (BMSCs). The effects of alcohol and miR-19a-3p on vascularization and osteogenic differentiation were analyzed in vitro using BMSCs and human umbilical vein endothelial cells (HUVECs). An in vivo alcohol-fed mouse model of femur fracture healing was also established, and radiological and histomorphometric analyses were used to evaluate the role of miR-19a-3p. The binding of miR-19a-3p to forkhead box F2 (FOXF2) was analyzed using a luciferase reporter assay. Results. miR-19a-3p was identified as one of the key regulators in the osteogenic differentiation of BMSCs, and was found to be downregulated in the alcohol-fed mouse model of fracture healing. In vitro, miR-19a-3p expression was downregulated after ethanol administration in both BMSCs and HUVECs. Vascularization and osteogenic differentiation were independently suppressed by ethanol and reversed by miR-19a-3p. In addition, the luciferase reporter assay showed that FOXF2 is the direct binding target of miR-19a-3p. In vivo, miR-19a-3p agomir stimulated callus transformation and improved the alcohol-impaired fracture healing. Conclusion. This study is the first to demonstrate that the miR-19a-3p/FOXF2 axis has a pivotal role in alcohol-impaired fracture healing, and may be a potential therapeutic target. Cite this article: Bone Joint Res 2022;11(6):386–397


Bone & Joint Research
Vol. 11, Issue 8 | Pages 585 - 593
1 Aug 2022
Graham SM Jalal MMK Lalloo DG Hamish R. W. Simpson A

Aims

A number of anti-retroviral therapies (ART) have been implicated in potentially contributing to HIV-associated bone disease. The aim of this study was to evaluate the effect of combination ART on the fracture healing process.

Methods

A total of 16 adult male Wistar rats were randomly divided into two groups (n = eight each): Group 1 was given a combination of Tenfovir 30 mg, Lamivudine 30 mg, and Efavirenz 60 mg per day orally, whereas Group 2 was used as a control. After one week of medication preload, all rats underwent a standardized surgical procedure of mid-shaft tibial osteotomy fixed by intramedullary nail with no gap at the fracture site. Progress in fracture healing was monitored regularly for eight weeks. Further evaluations were carried out after euthanasia by micro-CT, mechanically and histologically. Two blinded orthopaedic surgeons used the Radiological Union Scoring system for the Tibia (RUST) to determine fracture healing.


Bone & Joint Research
Vol. 13, Issue 10 | Pages 559 - 572
8 Oct 2024
Wu W Zhao Z Wang Y Liu M Zhu G Li L

Aims

This study aimed to demonstrate the promoting effect of elastic fixation on fracture, and further explore its mechanism at the gene and protein expression levels.

Methods

A closed tibial fracture model was established using 12 male Japanese white rabbits, and divided into elastic and stiff fixation groups based on different fixation methods. Two weeks after the operation, a radiograph and pathological examination of callus tissue were used to evaluate fracture healing. Then, the differentially expressed proteins (DEPs) were examined in the callus using proteomics. Finally, in vitro cell experiments were conducted to investigate hub proteins involved in this process.


Aims

Exosomes derived from bone marrow mesenchymal stem cells (BMSCs) have been reported to be a promising cellular therapeutic approach for various human diseases. The current study aimed to investigate the mechanism of BMSC-derived exosomes carrying microRNA (miR)-136-5p in fracture healing.

Methods

A mouse fracture model was initially established by surgical means. Exosomes were isolated from BMSCs from mice. The endocytosis of the mouse osteoblast MC3T3-E1 cell line was analyzed. CCK-8 and disodium phenyl phosphate microplate methods were employed to detect cell proliferation and alkaline phosphatase (ALP) activity, respectively. The binding of miR-136-5p to low-density lipoprotein receptor related protein 4 (LRP4) was analyzed by dual luciferase reporter gene assay. HE staining, tartrate-resistant acid phosphatase (TRAP) staining, and immunohistochemistry were performed to evaluate the healing of the bone tissue ends, the positive number of osteoclasts, and the positive expression of β-catenin protein, respectively.


Bone & Joint Research
Vol. 9, Issue 12 | Pages 857 - 869
1 Dec 2020
Slullitel PA Coutu D Buttaro MA Beaule PE Grammatopoulos G

As our understanding of hip function and disease improves, it is evident that the acetabular fossa has received little attention, despite it comprising over half of the acetabulum’s surface area and showing the first signs of degeneration. The fossa’s function is expected to be more than augmenting static stability with the ligamentum teres and being a templating landmark in arthroplasty. Indeed, the fossa, which is almost mature at 16 weeks of intrauterine development, plays a key role in hip development, enabling its nutrition through vascularization and synovial fluid, as well as the influx of chondrogenic stem/progenitor cells that build articular cartilage. The pulvinar, a fibrofatty tissue in the fossa, has the same developmental origin as the synovium and articular cartilage and is a biologically active area. Its unique anatomy allows for homogeneous distribution of the axial loads into the joint. It is composed of intra-articular adipose tissue (IAAT), which has adipocytes, fibroblasts, leucocytes, and abundant mast cells, which participate in the inflammatory cascade after an insult to the joint. Hence, the fossa and pulvinar should be considered in decision-making and surgical outcomes in hip preservation surgery, not only for their size, shape, and extent, but also for their biological capacity as a source of cytokines, immune cells, and chondrogenic stem cells.

Cite this article: Bone Joint Res 2020;9(12):857–869.


Objectives

MicroRNAs (miRNAs) have been reported as key regulators of bone formation, signalling, and repair. Fracture healing is a proliferative physiological process where the body facilitates the repair of a bone fracture. The aim of our study was to explore the effects of microRNA-186 (miR-186) on fracture healing through the bone morphogenetic protein (BMP) signalling pathway by binding to Smad family member 6 (SMAD6) in a mouse model of femoral fracture.

Methods

Microarray analysis was adopted to identify the regulatory miR of SMAD6. 3D micro-CT was performed to assess the bone volume (BV), bone volume fraction (BVF, BV/TV), and bone mineral density (BMD), followed by a biomechanical test for maximum load, maximum radial degrees, elastic radial degrees, and rigidity of the femur. The positive expression of SMAD6 in fracture tissues was measured. Moreover, the miR-186 level, messenger RNA (mRNA) level, and protein levels of SMAD6, BMP-2, and BMP-7 were examined.


Bone & Joint Research
Vol. 9, Issue 3 | Pages 99 - 107
1 Mar 2020
Chang C Jou I Wu T Su F Tai T

Aims

Cigarette smoking has a negative impact on the skeletal system, causes a decrease in bone mass in both young and old patients, and is considered a risk factor for the development of osteoporosis. In addition, it disturbs the bone healing process and prolongs the healing time after fractures. The mechanisms by which cigarette smoking impairs fracture healing are not fully understood. There are few studies reporting the effects of cigarette smoking on new blood vessel formation during the early stage of fracture healing. We tested the hypothesis that cigarette smoke inhalation may suppress angiogenesis and delay fracture healing.

Methods

We established a custom-made chamber with airflow for rats to inhale cigarette smoke continuously, and tested our hypothesis using a femoral osteotomy model, radiograph and microCT imaging, and various biomechanical and biological tests.


Bone & Joint Research
Vol. 8, Issue 8 | Pages 357 - 366
1 Aug 2019
Zhang B Sun H Zhan Y He Q Zhu Y Wang Y Luo C

Objectives

CT-based three-column classification (TCC) has been widely used in the treatment of tibial plateau fractures (TPFs). In its updated version (updated three-column concept, uTCC), a fracture morphology-based injury mechanism was proposed for effective treatment guidance. In this study, the injury mechanism of TPFs is further explained, and its inter- and intraobserver reliability is evaluated to perfect the uTCC.

Methods

The radiological images of 90 consecutive TPF patients were collected. A total of 47 men (52.2%) and 43 women (47.8%) with a mean age of 49.8 years (sd 12.4; 17 to 77) were enrolled in our study. Among them, 57 fractures were on the left side (63.3%) and 33 were on the right side (36.7%); no bilateral fracture existed. Four observers were chosen to classify or estimate independently these randomized cases according to the Schatzker classification, TCC, and injury mechanism. With two rounds of evaluation, the kappa values were calculated to estimate the inter- and intrareliability.