LGR5 enhances the osteoblastic differentiation of MC3T3-E1 cells through the Wnt/ß-catenin pathway.

Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) is a Wnt-associated gene that contributes to cell proliferation and self-renewal in various organs. LGR5 is expressed in Ewing sarcoma, and LGR5-overexpressing mesenchymal stem cells promote fracture healing. However, the effects of LGR5 on osteoblastic differentiation remain unclear. The aim of the present study was to explore the function of LGR5 in osteoblastic differentiation. LGR5 was overexpressed or knocked down in the MC3T3-E1 pre-osteoblastic cell line via lentiviral transfection and its function in osteoblastic differentiation was investigated. The mRNA expression levels of the osteoblast differentiation markers alkaline phosphatase (ALP), osteocalcin and collagen type I a1 were determined, and ALP and Alizarin red staining were performed. In addition, the effects of LGR5 modulation on ß-catenin and the expression of target genes in the Wnt pathway were investigated. The results revealed that the overexpression of LGR5 promoted osteoblastic differentiation. This was associated with enhancement of the stability of ß-catenin and its levels in the cell nucleus, which enabled it to activate Wnt signaling. By contrast, the inhibition of LGR5 decreased the osteogenic capacity of MC3T3-E1 cells. These results indicate that LGR5 is a positive regulator of osteoblastic differentiation, whose effects are mediated through the Wnt/ß-catenin signaling pathway. This suggests suggesting that the regulation of LGR5/Wnt/ß-catenin signaling has potential as a therapy for osteoporosis.

Inhibition of Y1 Receptor Promotes Osteogenesis in Bone Marrow Stromal Cells via cAMP/PKA/CREB Pathway.

Inhibition of neuropeptide Y1 receptor stimulates osteogenesis in vitro and in vivo. However, the underlying mechanisms involved in these effects remain poorly understood. Here we identify the effects of Y1 receptor deficiency on osteogenic differentiation in human bone marrow stromal cells (BMSCs) by using genetic and pharmacological regulation, and to explore the pathways mediating these effects. In BMSCs, inhibition of Y1 receptor stimulates osteogenesis and upregulates the expression levels of the master transcriptional factor RUNX2. Mechanistically, Y1 receptor deficiency increases the levels of intracellular cAMP, which via protein kinase A (PKA) mediated pathways results in activation of phospho-CREB (p-CREB). We find RUNX2 activation induced by Y1 receptor deficiency is reversed by H-89, a PKA inhibitor. These results indicate Y1 receptor deficiency activates PKA-mediated phosphorylation of CREB, leading to activation of RUNX2 and enhances osteogenic differentiation in BMSCs. In conclusion, these data indicate that Y1 receptor deficiency promotes osteogenic differentiation by RUNX2 stimulation through cAMP/PKA/CREB pathway.

The acromion-greater tuberosity impingement index: A new radiographic measurement and its association with rotator cuff pathology.

PURPOSE: Several radiographic parameters describe humeral head coverage by the acromion. We describe a new radiographic measurement, the acromion-greater tuberosity impingement index (ATI), and its ability to predict rotator cuff pathology. METHODS: The ATI was measured with magnetic resonance imaging (MRI) and X-ray analysis in 83 patients with rotator cuff pathology and 76 patients with acute rotator cuff tears. The lateral acromial angle (LAA), acromion type, the acromion index (AI) and the critical shoulder angle (CSA) were measured to assess their correlations with the ATI. Receiver operating characteristic (ROC) curves were used to predict degenerative rotator cuff pathology. The change in the ATI after acromion surgery was evaluated in both groups. RESULTS: According to the ROC curves, the ATI is a good predictor of degenerative rotator cuff pathology on both X-ray (cut-off, 0.865) and MRI (cut-off, 0.965). Patients with degenerative rotator cuff pathology had a significantly higher average ATI compared to the trauma group (p = 0.001 for X-ray and MRI). The degenerative group had a significantly lower LAA (p = 0.001) and a higher ratio of type III acromion (p = 0.035) than the trauma group. The ATI on X-ray was negatively related to the LAA and positively related to the AI, the CSA and acromion type (each p < 0.05). The ATI on MRI was negatively related to the LAA and positively related to the AI and acromion type (each p <0.05). More patients in the degenerative group than the trauma group needed acromioplasty or acromion decompression (p < 0.05). The ATI on MRI was significantly lower after acromion surgery compared to before surgery in both groups (p < 0.05). CONCLUSION: The ATI is a good predictor of degenerative supraspinatus tendon tears or subacromial impingement syndrome. The ATI on MRI is more accurate and can precisely guide acromion surgery.

MicroRNA-744 promotes proliferation of osteosarcoma cells by targeting PTEN.

MicroRNAs (miRNAs/miRs) are non-coding RNAs that regulate protein synthesis by targeting mRNAs for translational repression or degradation. Previous studies have reported that aberrant expression of miR­744 may be involved in human osteosarcoma; however, the underlying mechanisms remain elusive. In the present study, the expression levels of miR­744 and its downstream signals were determined by reverse transcription­quantitative PCR and western blotting. Cell proliferation was assessed using the bromodeoxyuridine assay, and the target of miR­744 was investigated using a dual­luciferase activity assay. The present study identified a significant upregulation of miR­744 in osteosarcoma tissues compared with adjacent non­tumor tissues. Furthermore, it was demonstrated that ectopic overexpression of miR­744 induced by a miR­744 precursor significantly enhanced proliferation of the osteosarcoma cell line MG63, whereas opposite results were observed following suppression of miR­744 with its inhibitor. Moreover, as a unique anti­oncogene, PTEN was identified as a direct target of miR­744. It was confirmed that miR­744 downregulated PTEN expression in MG63 cells by targeting the PTEN 3'untranslated region, and that the downstream AKT signal was also regulated by miR­744. Collectively, the present results suggested that miR­744 promoted proliferation of human osteosarcoma cells by directly regulating the PTEN/AKT signaling pathway.

A technique combining "U" shape suture and shared tunneling to treat the posterior cruciate ligament rupture and posterior root tears of the medial meniscus.

BACKGROUND: The standard treatment of the posterior cruciate ligament (PCL) rupture accompanied with the posterior root of medial meniscus (PRMM) tears is controversial. Our research describes a minimally invasive technique for the PCL rupture accompanied with the PRMM tears. METHODS: We described a "U" shape suture and shared tunneling technique to treat the PCL rupture accompanied with PRMM tears. Three patients (ages 28, 42, and 59 years old) who underwent this surgery have been followed up for more than 1 year at most. The MRI was done, and the hospital for special surgery (HSS) score was adopted to evaluate the clinical effect. Firstly, we built both femoral and tibial bone tunnels for the PCL reconstruction. Secondly, we used the suture hook to pass the suture line through the PRMM. Thirdly, we passed the prepared tendon through the bone tunnel and fixed the prepared tendon by an endobutton plate and an interference screw (Smith & Nephew) respectively on the side of the femur and tibia. At last, we used an endobutton plate (Smith & Nephew) outside the tibial bone tunnel to fix the PRMM. RESULTS: These three patients did not show any complications. At 1 year after the operation, we found good knee stability, negative posterior drawer test, and normal range of motion compared with the contralateral knee joint. The MRI also showed a good union of the PRMM and PCL. The hospital for special surgery (HSS) score was 90 points. CONCLUSIONS: With an ideal therapeutic effect, this technique is worthy to be promoted for patients with the PCL rupture and PRMM tears.

No effectiveness of anticoagulants for thromboprophylaxis after non-major knee arthroscopy: a systemic review and meta-analysis of randomized controlled trials.

Arthroscopic knee surgery is the most commonly performed orthopedic procedure worldwide and whether thromboprophylaxis should be undertaken after knee arthroscopy is still controversial. To evaluate the efficacy of thromboprophylaxis for deep venous thrombosis (DVT) and venous thromboembolism (VTE) after knee arthroscopic surgery. A meta-analysis was conducted using data from eight randomized trials (4148 patients) to compare thromboprophylaxis with placebo or no prophylactic treatment in patients undergoing knee arthroscopy. The benefits and harms of thromboprophylaxis were evaluated, including the incidence of asymptomatic DVT, symptomatic VTE, pulmonary embolism and anti-coagulation related adverse events. Thromboprophylaxis significantly decreased the incidence of DVT (95% CI 0.07-0.64, P = 0.006) and symptomatic VTE in patients undergoing knee arthroscopy (95% CI 0.23-0.76, P = 0.004), but not significantly decreased the incidence of pulmonary embolism (n.s.). Regarding to non-major knee arthroscopy surgery (simple surgical procedures without ligament reconstruction), no significant difference of the incidence of DVT or symptomatic VTE was noted between thromboprophylactic group and control group (n.s.). Thromboprophylactic treatment showed higher incidence rate of anti-coagulation related adverse events compared with the control group (95% CI 1.12-1.90, P = 0.005). There was no significant difference of the incidence of clinically relevant major bleeding between the two groups (n.s.). This meta-analysis indicates no effectiveness of thromboprophylaxis for preventing DVT or symptomatic VTE in patients undergoing non-major knee arthroscopy. Regarding to patient undergoing knee ligament construction, the thromboprophylactic strategy should mainly take into account the patient's risk factors.

Calcifying tendinitis of the long head of the biceps brachii and superior labrum: a report of one case and literature review.

Calcifying tendinitis of the shoulder is characterized with the formation of the calcium deposits in tendon, which mostly involves supraspinatus. The formation of the calcium deposits may be related to the excessive mechanical stimulation and non-tenocytes generation from tendon stem cell. The disease is usually associated with pain, especially when activating the shoulder. We describe one case of calcifying tendinitis involving the long head of the biceps brachii and superior labrum. The related literature and researches are also reviewed. After reviewing the past articles, there are no similar cases of calcification involving the long head of the biceps brachii and superior labrum. The diagnosis and treatment scheme may be similar with Calcifying tendinitis of the supraspinatus. The differential diagnosis of calcification involving the long head of the biceps brachii and superior labrum and glenoid cavity fracture is very important. Calcifying tendinitis involving the long head of the biceps brachii and superior labrum is rare and the diagnosis need to rule out fractures. The surgical treatment of arthroscopy is effective and relieves the symptoms quickly, but may not be the first choice.

Salidroside inhibits steroid-induced avascular necrosis of the femoral head via the PI3K/Akt signaling pathway: In vitro and in vivo studies.

Dexamethasone (Dex) and other glucocorticoids are widely used to treat serious infections and immunological diseases, however they may cause steroid­induced avascular necrosis of the femoral head (SANFH). Salidroside (Sal) has demonstrated an anti­apoptotic effect on neurocytes by activating the phosphoinositide 3­kinase (PI3K)/protein kinase B (Akt) signaling pathway. In the present study, primary osteoblasts were used in vitro and in rats in vivo to determine the anti-apoptotic effect of Sal on SANFH. The result of the present study demonstrated that pretreatment with Sal increased the cell survival rate while decreasing the cell apoptosis and lactate dehydrogenase release rate. Additionally, Sal also caused the reduction of TUNEL positive cells in TUNEL staining assay. Sal decreased the expression of cleaved caspase-3, cleaved caspase­9, apoptosis regulator BAX and cytochrome C, while it increased the expression of B cell lymphoma­2 and phosphorylated­Akt in Dex­induced osteoblasts. In vivo Sal protected against SANFH in rats by decreasing the percentage of empty lacunae. The present study demonstrated that Sal alleviated Dex­induced osteoblast apoptosis by activating the PI3K/Akt signaling pathway and downregulating caspase­3 expression in osteoblasts. Sal also protected against SANFH in a rat model of SANFH by decreasing the percentage of empty lacunae. The inhibition of the mitochondrial apoptosis pathway was also involved. Further research is required to determine the full underlying mechanisms by which Sal has an effect.

Muscle fiber types composition and type identified endplate morphology of forepaw intrinsic muscles in the rat.

The failure to accept reinnervation is considered to be one of the reasons for the poor motor functional recovery of intrinsic hand muscles (IHMs) after nerve injury. Rat could be a suitable model to be used in simulating motor function recovery of the IHMs after nerve injury as to the similarities in function and anatomy of the muscles between human and rat. However, few studies have reported the muscle fiber types composition and endplate morphologic characteristics of intrinsic forepaw muscles (IFMs) in the rat. In this study, the myosin heavy chain isoforms and acetylcholine receptors were stained by immunofluorescence to show the muscle fiber types composition and endplates on type-identified fibers of the lumbrical muscles (LMs), interosseus muscles (IMs), abductor digiti minimi (AM) and flexor pollicis brevis (FM) in rat forepaw. The majority of IFMs fibers were labeled positively for fast-switch fiber. However, the IMs were composed of only slow-switch fiber. With the exception of the IMs, the other IFMs had a part of hybrid fibers. Two-dimensional morphological characteristics of endplates on I and IIa muscle fiber had no significant differences among the IFMs. The LMs is the most suitable IFMs of rat to stimulate reinnervation of the IHMs after nerve injury. Gaining greater insight into the muscle fiber types composition and endplate morphology in the IFMs of rat may help understand the pathological and functional changes of IFMs in rat model stimulating reinnervation of IHMs after peripheral nerve injury.

A mini-invasive technique for severe arthrofibrosis of the knee: A technical note.

PURPOSE: In this article, a mini-invasive technique is described, which consists of arthroscopic adhesiolysis and quadriceps pie-crusting lengthening basing on pre-operative sonographic examination. Sonographic diagnostic value of quadriceps tendon fibrosis is also evaluated. METHODS: Pre-operative sonographic examination was performed to make an accurate location diagnosis of quadriceps fibrosis. After arthroscopic adhesiolysis, percutaneous pie-crusting release was performed basing on preoperative sonographic examination. An 18-gauge needle was used to puncture the stiff fibrous band of the distal and lateral quadriceps tendon under maximum knee flexion. The contractural quadriceps tendon is gradually released after 60-100 needle punctures. RESULTS: This technique was performed in five post-traumatic stiff knees and three stiff knees after previous infection. The contractural rectus femoris tendon is average 22% thinner than contralateral parts according to sonographic measurement. Mean maximum flexion increased from 35° preoperatively to 80° after arthroscopic adhesiolysis and 120° after pie-crusting. CONCLUSIONS: This technique is a simple, effective and mini-invasive method, allowing an immediate, aggressive rehabilitation postoperatively. Pre-operative sonographic location of quadriceps tendon fibrosis could potentially improve the efficacy and accuracy of percutaneous pie-crusting procedures.

[Arthroscopic treatment of symptomatic anterior cruciate ligament cysts of the knee].

OBJECTIVE: To explore the clinical symptom and effect of arthroscopic treatment of symptomatic anterior cruciate ligament (ACL) cysts of the knee. METHODS: Clinical data from 12 symptomatic ACL cysts patients from January 2005 to December 2010 were retrospectively analyzed,including 8 males and 4 females,with an average age of (33.7±9.5) years old (ranged, 19 to 53 years old). The locations were the left knee in 5 cases and the right knee in 7 cases. The disease duration ranged from 3 to 48 months,with a mean of (15.8±13.2) months. All cysts were arthroscopically resected. Range of motion was measured preoperatively and postoperatively, and Lysholm scoring system was used to evaluate the knee function. RESULTS: All the incisions healed by first intention, and no complications occurred. Twelve patients were followed up for an average of (32.3±6.6) months(ranged, 24 to 48 months). The symptoms of arthralgia,swelling and interlocking of the affected knees disappeared. There was no recurrence during the follow-up. There were significant differences in the range of motion and Lysholm score between pre-operation and post-operation. CONCLUSION: Arthroscopic surgery, showing its advantages of minimal invasion and rapid recovery,is an effective measure in the treatment of ACL cysts.

De novo characterization of the Anthurium transcriptome and analysis of its digital gene expression under cold stress.

BACKGROUND: Anthurium andraeanum is one of the most popular tropical flowers. In temperate and cold zones, a much greater risk of cold stress occurs in the supply of Anthurium plants. Unlike the freeze-tolerant model plants, Anthurium plants are particularly sensitive to low temperatures. Improvement of chilling tolerance in Anthurium may significantly increase its production and extend its shelf-life. To date, no previous genomic information has been reported in Anthurium plants. RESULTS: Using Illumina sequencing technology, we generated over two billion base of high-quality sequence in Anthurium, and demonstrated de novo assembly and annotation of genes without prior genome information. These reads were assembled into 44,382 unigenes (mean length = 560 bp). Based on similarity search with known protein in the non-redundant (nr) protein database, 27396 unigenes (62%) were functionally annotated with a cut-off E-value of 10-5. Further, DGE tags were mapped to the assembled transcriptome for gene expression analysis under cold stress. In total, 4363 differentially expressed genes were identified. Among these genes, 292, 805 and 708 genes were up-regulated after 1-h, 5-h and 24-h cold treatment, respectively. Then we mapped these cold-induced genes to the KEGG database. Specific enrichment was observed in photosynthesis pathway, metabolic pathways and oxidative phosphorylation pathway in 1-h cold-treated plants. After a 5-h cold treatment, the metabolic pathways and oxidative phosphorylation pathway were significantly identified as the top two pathways. After 24-h cold treatment, mRNA surveillance pathway, RNA transport pathway and plant-pathogen interaction pathway were significantly enriched. Together, a total of 39 cold-inducible transcription factors were identified, including subsets of AP2/ERF, Zinc figure, NAC, MYB and bZIP family members. CONCLUSION: Our study is the first to provide the transcriptome sequence resource for Anthurium plants, and demonstrate its digital gene expression profiling under cold conditions using the assembled transcriptome data for reference. These data provides a valuable resource for genetic and genomic studies under abiotic conditions for Anthurium plants.

[Application of orientation to the mechanical alignment of lower limbs in operation of high tibial osteotomy].

OBJECTIVE: To evaluate the effects of orientation to the mechanical alignment of lower limbs in high tibial osteotomy (HTO). METHODS: From March 2005 to July 2010, the data of 57 patients (63 knees) with medial compartment osteoarthritis were retrospectively analyzed. There were 24 males and 33 females with an average age of 52 years (ranged, 34 to 68). HTO was used in all the patients, and with wire the exact orientation to the mechanical alignment of lower limbs was performed in order to obtain good angle of intercepted bone. X-rays of full-length lower limbs were done at the 3rd month after operation and final follow-up, in which femorotibial angle would be observed. Clinical results were evaluated according to Hospital for Special Surgery knee scores (HSS) including pain, function, activities, myodynamia, deformity and instability. RESULTS: All patients were followed up from 24 to 60 months with an average of 36.7 months. All osteotomy site achieved radiographic healing. The femorotibial angle was corrected from preoperative (182.8 +/- 2.9) degrees to postoperative (167.6 +/- 2.5) degrees and (168.1 +/- 2.5) degrees at final follow-up (compared with preoperative data, P < 0.01). Pain relieved and genu valgum recovered. HSS score improved from preoperative 69.5 +/- 7.1 to postoperative 91.1 +/- 4.9 and 92.2 +/- 5.6 at final follow-up. According to HSS standard, 43 knees got excellent results, 18 good and 2 fair. CONCLUSION: The orientation to mechanical alignment of lower limbs using wire during operation of HTO is a good method in correcting femorotibial angle and treating medial compartment osteoarthritis of the knee. Moreover, the method is simple and precise for orthopedist.

Little clinical advantage of computer-assisted navigation over conventional instrumentation in primary total knee arthroplasty at early follow-up.

PURPOSE: Even though computer-assisted navigation systems have been shown to improve the accuracy of implantation of components into the femur and tibia, long-term results are lacking and there is little evidence yet that navigation techniques also improve functional outcomes and implant longevity following total knee arthroplasty (TKA). The aim of this study was to summarize and compare the clinical outcomes of total knee arthroplasties (TKAs) performed using navigation-assisted and conventional techniques. METHODS: The study was conducted according to the guidelines described in the Cochrane Handbook for Systematic Reviews of Interventions and Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statements. Methodological features were rated independently by two reviewers. A meta-analysis of randomized controlled trials (RCTs) or quasi- randomized controlled trials (qRCTs) was carried out to evaluate the efficacy of CAS versus conventional TKA. Data were pooled in fixed and random effects models and the weighted mean difference (WMD) and odds ratio (OR) were calculated. Heterogeneity across studies was determined, and subgroup analyses by the type of navigation system (image-based or image-free navigation system) were conducted. RESULTS: Twenty-one studies that included 2333 knees were collected from different countries. The surgical time was longer for CN TKA than for the conventional procedure. There was no significant difference in the Knee Society Score between the two groups at the 3-month and 6-month follow-up. The rates of postoperative complications in patients who had CN TKA were similar to those in the patients who had conventional TKA. CONCLUSION: No significant differences in short-term clinical outcomes were found following TKAs performed with and without computer navigation system. However, there is clearly a need for additional high-quality clinical trials with long-term follow-up to confirm the clinical benefits of computer-assisted surgery.

[The use of minimally invasive injectable graft and internal fixation in tibial plateau fractures].

OBJECTIVE: To value the use of an injectable minimally invasive calcium sulfate cement for displaced tibial plateau fractures. METHODS: Thirteen patients with lateral tibial plateau fractures treated with internal fixation and bone grafting were matched with 13 patients treated using internal fixation and an injectable calcium sulfate cement. The clinical data were retrospectively analyzed. All patients were followed up for a minimum of one year. The peri-operative complication, quality of reduction, maintenance of reduction, function assessment and development of post-traumatic osteoarthritis was compared in both groups. RESULTS: Ten patients in the internal fixation and bone graft group had excellent anatomical reductions as judged on immediate post-operative radiographs but some loss of reduction on follow-up at one year was observed in 8 of the 13 (61%) cases. Twelve patients from the MIIG group had an excellent reduction on immediate post-operative radiographs but 3 (23%)demonstrated some loss of reduction of the plateau at one year follow-up (P < 0.05). CONCLUSIONS: The use of MIIG and internal fixation is associated with more favourable clinical results than conventional treatment with internal fixation and bone grafting for lateral tibial plateau fractures.

[Percutaneous reduction and fixation of osteoporotic fractures for the proximal humerus in a geriatric population].

OBJECTIVE: To appraise the value of clinical treatment of percutaneous reduction and fixation of osteoporotic fractures for the proximal humerus in a geriatric population. METHODS: Postoperation complication, mortality in hospital and within the first three months postoperation, operation time, blood transfusion requirement, the functional outcome of the shoulder had been analysed and observed in 37 cases for open and closed fixation. RESULTS: Closed reduction provided the benefit of obtaining and holding adequate reduction without the soft-tissue dissection of open reduction and internal fixation. The general complication and mortality in the first three months postoperation in the open reduction and internal fixation cases were more severe than the percutaneous cases. CONCLUSIONS: Open operation increases the risk of the geriatric population with osteoporotic proximal humerus fracture; percutaneous reduction and fixation may be preferable.