Effectiveness of a patient-specific guide for femoral stem implantation in primary total hip arthroplasty: a randomized control trial.

PURPOSE: The purpose of the present study was to evaluate the efficacy and feasibility of a novel CT-based patient-specific femoral alignment guide (PSG) as compared with conventional pre-operative planning during THA. METHODS: From March 2020 to September 2020, patients receiving unilateral primary THA were enrolled and randomly allocated to the conventional pre-operative planning group and the PSG group. Primary outcomes were radiographic measurements including lower limb length, femoral offset, femoral anteversion and stem varus/valgus angle, and post-operative perception of leg length discrepancy (LLD). Secondary outcomes were surgical time, intra-operative blood loss, total blood loss, visual analogue scale (VAS), and Harris Hip Score (HHS). The occurrence of post-operative complications was also recorded. RESULTS: Of the 104 patients screened, 80 cases were enrolled for analysis. The demographics of the two groups were similar. The PSG group illustrated significant improvements (p < 0.001) in lower limb length, femoral offset, femoral anteversion, and stem varus/valgus angle. Patients in the PSG group showed more favourable HHS (p < 0.001) at seven day, four week, andthree month (p = 0.003) follow-up. Perception of LLD was found significantly lower in the PSG group at three tmonth (p = 0.043), six month (p = 0.025), and 12-month (p = 0.048) follow-up. Utilization of the PSG had no significant increase in operative time, intra-operative blood loss, total blood loss, or VAS. No complication was noted in either group. CONCLUSION: Relative to conventional pre-operative planning, the application with the PSG could potentially provide a simple and reliable solution for improving femoral prosthesis orientation in THA with high accessibility and low healthcare costs. TRN: ChiCTR2000031043 Date of registration: 2020/3/21.

Dioscin inhibits the growth of human osteosarcoma by inducing G2/M-phase arrest, apoptosis, and GSDME-dependent cell death in vitro and in vivo.

Pyroptosis is a form of programmed cell death (PCD) that plays a vital role in immunity and diseases. Although it was recently reported that chemotherapy drugs can induce pyroptosis through caspase-3-dependent cleavage of gasdermin E (GSDME), the role of pyroptosis in osteosarcoma (OS) with dioscin is less understood. In this study, we explored the effects of dioscin on OS in vitro and in vivo and further elucidated the underlying molecular mechanisms and found that dioscin-triggered pyroptosis in GSDME-dependent cell death and that GSDME-N was generated by caspase-3. Furthermore, dioscin inhibited cancer cell growth by inducing G2/M arrest and apoptosis through the JNK/p38 pathway. In vivo, dioscin significantly inhibited OS proliferation. Taken together, our results demonstrate that dioscin can induce apoptosis through the JNK/p38 pathway and GSDME-dependent pyroptosis in OS, identifying it as a potential therapeutic drug for treatment of this disease.

LncRNA CRNDE is activated by SP1 and promotes osteosarcoma proliferation, invasion, and epithelial-mesenchymal transition via Wnt/ß-catenin signaling pathway.

Long noncoding RNAs (lncRNAs) were identified as a vital part in the development and progression of cancer in recent years. Colorectal neoplasia differentially expressed (CRNDE), a lncRNA, functions as an oncogene in some malignant neoplasias, but its role in the progression of osteosarcoma (OS) is still poorly understood. To dissect the difference in the expression of CRNDE, quantitative real-time polymerase chain reaction was utilized to evaluate it in OS tissues and cell lines (U2OS, MG63, and MNNG/HOS) compared with that in the adjacent normal tissues/osteoblast cells (hFOB1.19). The role of CRNDE in OS lines was assessed using Cell Counting Kit-8, colony formation, 5-ethynyl-2'-deoxyuridine staining, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining, flow cytometry, Transwell assays, and Western blot, respectively. The results demonstrated that the expression of CRNDE was high in OS tissues and cell lines, and partly induced by SP1. CRNDE knockdown attenuated OS cell proliferation and invasion and induced apoptosis and G0/G1 arrest. Moreover, the expression of mesenchymal markers N-cadherin, Vimentin and Snail were downregulated, while the expression of epithelial markers E-cadherin and ZO-1 were conversely upregulated due to CRNDE knockdown. The mechanistic investigations showed that CRNDE promoted glycogen synthase kinase-3ß phosphorylation to activate the Wnt/ß-catenin pathway. The results suggested that lncRNA CRNDE indeed contributed to OS proliferation, invasion, and epithelial-mesenchymal transition, working as an oncogene, demonstrating that lncRNA CRNDE may be a valid therapeutic target for the OS.

Icariin Protects against Glucocorticoid-Induced Osteonecrosis of the Femoral Head in Rats.

BACKGROUND/AIMS: Glucocorticoid (GC)-related osteonecrosis of the femoral head (ONFH) is a common complication following administration of steroids to treat many diseases. Our previous study demonstrated that icariin (ICA) might have a beneficial effect on the bone marrow mesenchymal stem cells (BMSCs) of patients with steroid-associated osteonecrosis. In this study, we investigated the underlying mechanisms of ICA associated with the potential enhancement of osteogenesis and anti-adipogenesis in GC-related ONFH. METHODS: In vitro cell proliferation was evaluated by CCK-8 assay. Alizarin red S and alkaline phosphatase (ALP) activity were used to measure osteogenic differentiation, while adipogenic differentiation was revealed by oil red O staining and TG content assay. The expression level of osteogenesis-associated genes and PPARγ was evaluated by RT-qPCR, western blotting and immunofluorescence. A total of 30 female SD rats were randomly separated into three groups: a control group, a methylprednisolone (MPS) group and a MPS + ICA group. Serum ALP and TG (triglyceride), micro-CT scanning, histological and immunohistochemical analyses were performed in the animal model. RESULTS: In the in vitro study, ICA promoted proliferation, improved osteogenic differentiation and suppressed adipogenic differentiation of BMSCs treated with MPS. The group treated with MPS and 10-6 M ICA expressed higher levels of Runx2, ALP, bone morphogenetic protein (BMP) 2, and OC and lower expression of PPARγ than the MPS group. In the in vivo study, ICA prevented bone loss in a rat model of GC-related ONFH as shown by micro-CT scanning, histological and immunohistochemical analyses. CONCLUSIONS: ICA is an effective compound for promoting bone repair and preventing or delaying the progression of GC-associated ONFH in rats. This effect can be explained by its ability to improve the balance between adipogenesis and osteogenesis, indicating that ICA is an effective candidate for management of GC-associated ONFH.

Long non-coding RNA BDNF-AS modulates osteogenic differentiation of bone marrow-derived mesenchymal stem cells.

For patients with osteoporosis, the inability of osteogenic differentiation is the key reason for bone loss. In this study, we investigated the expression and function of long non-coding RNA BDNF-AS in mesenchymal stem cell-derived osteogenic differentiation. Mouse bone marrow-derived mesenchymal stem cells (BMMSCs) were cultured in vitro and induced toward osteogenic differentiation. Quantitative real-time PCR (qRT-PCR) was used to evaluate gene expressions of BDNF-AS and BDNF during osteogenic differentiation. BMMSCs were also extracted from ovariectomized (OVX) mice. The dynamic change of BDNF-AS in OVX-derived BMMSCs during osteogenic differentiation was also evaluated. Lentivirus was used to upregulate BDNF-AS in BMMSCs. The effects of BDNF-AS upregulation on BMMSCs' proliferation and osteogenic differentiation were then evaluated. In addition, qRT-PCR and western blot were applied to further examine the effect of BDNF-AS upregulation on osteogenesis-associated signaling pathways, including BDNF, OPN, and Runx2, in osteogenic differentiation. BDNF-AS was downregulated, whereas BDNF was upregulated in osteogenic differentiation of BMMSCs. Among OVX-derived BMMSCs, BDNF-AS expression was upregulated during osteogenic differentiation. Lentivirus-induced BDNF-AS upregulation promoted BMMSCs self-proliferation but inhibited osteogenic differentiation, as demonstrated by proliferation, alizarin red staining, and alkaline phosphatase activity assays, respectively. QRT-PCR and western blot demonstrated that BDNF, OPN, and Runx2 were downregulated by BDNF-AS upregulation in the differentiated BMMSCs. BDNF-AS is dynamically regulated in osteogenic differentiation. Upregulating BDNF-AS inhibits osteogenesis, possibly through inverse regulation on BDNF and osteogenic signaling pathways.

Correction to: Arthroscopic release using F and C method versus conventional open release method in the treatment of gluteal muscle contracture: a comparative study.

Upon publication of this article [1], it was requested that: the corresponding author, Hong Wang's affiliation address be changed from.

Surface Properties and MC3T3-E1 Cell Response of Cortical Bone Allografts Modified with Low-Concentration Phosphoric Acid.

BACKGROUND/AIMS: This experimental study aimed to evaluate the effect of low-concentration phosphoric acid on the surface structure of cortical allografts. METHODS: Allogenic cortical bones were obtained from femurs and tibias of New Zealand white rabbits. The bones were modified by treatment with various concentrations of phosphoric acid (10%, 20% or 30%) for 10, 30 or 60 minutes, then evaluated by the following methods: 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and LIVE/DEAD assay, alkaline phosphatase (ALP) assay, biomechanical properties testing, contact angle detection, quantitative real-time polymerase chain reaction (Q-PCR), western blotting and scanning electron microscopy (SEM). RESULTS: Compared with the other groups, the group modified with 10% H3PO4 for 10 minutes had lower cytotoxicity according to MTT and LIVE/DEAD assays, higher hydrophilicity in the contact angle detection test and greater stability in the biomechanical properties test. Moreover, an up-regulation of osteopontin (OPN) in bones modified with 10% H3PO4 was observed by Q-PCR and western blotting. In addition, ALP assay and SEM showed that surface porosity and osteoinductivity were increased in the group modified with 10% H3PO4. CONCLUSIONS: Low-concentration phosphoric acid may be a potential method for surface modification of cortical allografts. Further animal experiments and animal infection model studies are required to validate the efficacy of surface-modified cortical allografts to repair large segmental bone defects.

Down-regulation of islet amyloid polypeptide expression induces death of human annulus fibrosus cells via mitochondrial and death receptor pathways.

Islet amyloid polypeptide (IAPP) exerts its biological effects by participating in the regulation of glucose metabolism and cell apoptosis. The main goal of the present study was to investigate the expression of IAPP in degenerated intervertebral disc tissue and IAPP's modulation of extracellular matrix (ECM) catabolic and anabolic genes in human AF cells. We found that the expression of IAPP, the calcitonin receptor, and receptor activity modifying protein decreased considerably in AF cells during the progression of intervertebral disc degeneration (IDD). Meanwhile, transfection with pLV-siIAPP decreased the expression of IAPP and its receptors and reduced glucose uptake and the expression of aggrecan, Col2A1, and BG. Down-regulation of IAPP also induced a significant increase in reactive oxygen species generation in AF cells, along with a decrease in matrix metalloproteinases and an increase in the concentration of cellular Ca2+, ultimately leading to death. Further analysis revealed that siIAPP intervention promoted the release of cytochrome c from mitochondria, resulting in the activation of Caspase-3 and Caspase-9. In contrast, significantly decreased expression of Caspase-3 and Caspase-9 was observed in AF cells transfected with pLV-IAPP. The concentrations of Fas and FasL proteins were significantly decreased in AF cells transfected with PLV-IAPP, while activation of the Fas/FasL system and cell death were induced by siIAPP intervention. Mechanistically, AMPK/Akt-mTOR signaling pathways were involved. In conclusion, down-regulation of IAPP expression induces the death of human AF cells via mitochondrial and death receptor pathways, potentially offering a novel therapeutic target for the treatment of IDD.

Arthroscopic release using F and C method versus conventional open release method in the treatment of gluteal muscle contracture: a comparative study.

BACKGROUND: Gluteal muscle contracture (GMC), a debilitating disease, usually starts in early childhood after variable dose of injections around the buttock, if left untreated it worsens gradually and persists throughout the life. Because the disease mostly affects adolescents and adults, there is always an aesthetic concerns. Purposeof the study was to introduce the arthroscopic F and C method of GMC release, and to compare its clinical efficiency with conventional open surgery in terms of clinical outcome, rate of complications, patient's satisfactions, and recurrence. METHODS: Between Jan 2013 and July 2015, 75 patients received an arthroscopic release with F and C release method and 71 patients received conventional open release of GMC. Primary surgeries in 16 years or older patients were included in the study. Two groups were compared clinically using Hip Outcome Scores - Activities of Daily Living Subscale (HOS-ADL), Hip Outcome Scores - Sports Subscale (HOS-Sports), Visual Analogue Scale (VAS), and Ye et al. evaluation criteria. RESULTS: No statistically significant differences were observed in Hip Outcome Scores - Activities of Daily Living Subscale (HOS-ADL) (P = 0.078), Hip Outcome Scores - Sports Subscale (HOS-Sports) (P = 0.340), and Visual Analogue Scale (VAS) (P = 0.524) between the two groups. 74 (98.7%) patients in the arthroscopic surgery group had good to excellent results, whereas 69 (97.1%) patients in the conventional open surgery group had good to excellent results (P = 0.727). No statistically significant difference was observed in recurrence rate (P = 0.612). Statistically significant differences were observed in incision length, use of post-operative analgesia, post-operative off-bed activity, and hospital stay. Complications were significantly higher in the conventional open surgery group (n = 21) than in the arthroscopic surgery group (n = 10) (P = 0.016). More importantly, cosmetic satisfaction was 100% in arthroscopic release group, whereas only 71% had cosmetic satisfaction in conventional open surgery group (P < 0.001). CONCLUSION: Both, arthroscopic surgery and conventional open surgery, are highly effective tools for the GMC release in adolescent and adult patients. Arthroscopic GMC release with F and C method allows precise and selective release of contracture bands with small surgical trauma resulting fewer complications, high cosmetic satisfaction and minimal recurrence.

Low bone mineral density in chronic hepatitis B virus infection: A case-control study.

OBJECTIVE: Osteoporosis is the well-known major complication in chronic hepatitis B virus (HBV) infection. Fewer reports are available of the relationship between bone loss and chronic HBV infection. We investigated the bone mineral density (BMD) and prevalence of osteoporosis in chronic HBV patients in comparison with healthy subjects. METHODS: We assessed 148 chronic HBV patients and 148 age- and gender-matched healthy controls by dual energy X-ray absorptiometry (DEXA) for determination of BMD. T-score was used to define bone status according to the World Health Organization's classification. RESULTS: The BMD values were significantly lower in HBV patients in all scan of specific regions compared with the controls (P < 0.05). The prevalence of osteoporosis in either of lumbar spine (LS), total hip (TH) or the femoral neck (FN) was significantly higher in the HBV patients group compared with the healthy controls. The rate of osteopenia and osteoporosis for HBV patients aged 45-54 years was significantly higher than that of the healthy controls. CONCLUSIONS: Chronic HBV infection was associated with low BMD and increased the risk of developing subsequent osteoporosis.

The effects of mPEG proportion and LA/GA ratio on degradation and drug release behaviors of PLGA-mPEG microparticles.

The purpose of this research was to evaluate the effects of mPEG proportion and LA/GA ratio on degradation and release behavior of PLGA-mPEG microparticles prepared by the emulsion evaporation method. Mometasone furoate was employed as model drug and encapsulated into five types of PLGA-mPEG microparticles in the same molecular weight (Mw), but different in mPEG proportion or LA/GA ratio. All types of PLGA-mPEG microparticles showed similar drug encapsulation efficiency and particle mean size, but PLGA-mPEG microparticles with higher mPEG proportion showed a faster Mw reduction rate, mass loss rate and size decrease rate according to the in vitro degradation experiment, and also, a faster drug release rate according to the in vitro release experiment. On the other hand, higher LA/GA ratio in PLGA chain of PLGA-mPEG causes a slower Mw reduction rate, mass loss rate, size decrease rate, and thus, a slower drug release rate.

TNF-a mediated inflammatory macrophage polarization contributes to the pathogenesis of steroid-induced osteonecrosis in mice.

The phenotypic polarization of macrophages are involved in steroid-induced osteonecrosis (ON). This study tried to investigate the detrimental and beneficial roles of M1/M2 macrophages associated with TNF-a in ON. Mice ON model was induced by the injection of methylprednisolone. After that, flow cytometry technique, immunohistochemistry, immunofluorescence, ELISA, and RT-PCR methods were used to investigate the expression pattern of macrophages and the expression of inflammatory cytokines. During the progression of ON, massive chronic inflammatory cells infiltrated into the necrotic zone, represented by the infiltration of macrophages. In the early stage of ON, there was high TNF-a activity; and a large population of M1 macrophages infiltrated into the necrotic zone. On the contrary, the expression of TNF-a gradually decreased; simultaneously, a larger M2 cell population presented in the necrotic zone in the late stage of ON. The increased M2 macrophages could be beneficial for resolving inflammation and promoting tissue repair, confirmed by the histologic findings of appositional new bone formation around the necrotic bone. Thus, it showed that TNF-a-mediated alteration of M1/M2 macrophage polarization contributed to the pathogenesis of steroid-induced osteonecrosis. M1-polarized macrophages appeared to be disruptive in the early stage of ON, while M2-polarized macrophages played an important role in the late stage during the pathogenesis of ON.

Outcomes of arthroscopic arthrolysis for the post-traumatic elbow stiffness.

PURPOSE: Post-traumatic contracture is a common complication after elbow trauma. If conservative therapy fails to restore adequate elbow motion, surgical release is recommended. Increase in arthroscopy knowledge and skills, as well as technological advances in the passed decade of years, has made arthroscopic arthrolysis a safe and reliable treatment for patients with a post-traumatic elbow contracture. The aim of this study was to report on the clinical outcome and improvement of ROM in post-traumatic stiff elbow treated by arthroscopic arthrolysis. METHODS: Between 2008 and 2012, 34 consecutive patients with post-traumatic stiffness were treated with arthroscopic arthrolysis. Active and passive elbow movement is encouraged the day after operation with the effective pain management. Mayo Elbow Performance Index (MEPI) and visual analogue scale were measured. RESULTS: At the final follow-up, the average arc of elbow motion increased from 48.6 ± 19.3 pre-operatively to 114.5 ± 25.7, with a mean improvement of 65.9°. The MEPI score improved from 68.2 ± 16.4 pre-operatively to 92.4 ± 21.6, with a mean improvement of 24.2 (p < 0.001). Results were good to excellent in 29 patients. CONCLUSION: Injuries are the most common cause of elbow stiffness requiring surgical release. The procedure of arthroscopic arthrolysis is a good option for the treatment of post-traumatic elbow stiffness as it restores normal elbow function. Early passive/active post-operative rehabilitation is very important.

Functional outcome of limb-salvage surgery with shoulder abduction brace for bone tumors around the shoulders.

BACKGROUND: The current trend is toward salvage of the extremity after tumor excision without compromising the extent of resection for bone tumor around the shoulders. OBJECTIVES: The aim of this study was to evaluate functional outcome of patients treated with limb-salvage surgeries combined with shoulder abduction braces. METHODS: Thirty-six patients with bone tumors around the shoulders, who had limb-sparing resection and reconstruction performed with a shoulder abduction brace, were retrospectively reviewed. Allograft transplantation and rigid internal fixation was performed in 22 patients and artificial prosthetic replacement was performed in 14 patients. Functional evaluation was performed based on the Musculoskeletal Tumour Society (MSTS) scoring system. RESULTS: The overall survival was 78.8% (26/33) at 2 years. The mean final functional score was (81.2 ± 19.6%). The MSTS of patients treated by allograft transplantation and prosthetic replacement were (79.4 ± 15.3%) and (81.9 ± 18.1%), respectively. The MSTS scores differed only slightly between these two groups (P > 0.05). All the patients regained good ROM of the shoulder joints. CONCLUSIONS: Satisfactory functional outcomes can be obtained by limb-salvage surgery for bone tumor around the shoulder. Postoperatively shoulder crutches with shoulder abduction brace are encouraged as the aid of reconstruction of shoulder joint function.

Editorial: Management of PJI/SSI after joint arthroplasty.

The management of periprosthetic joint infection (PJI) and surgical site infection (SSI) after joint arthroplasty poses a major challenge in orthopedic surgery. This Editorial provides an overview of the studies published in the special issue "Management of PJI/SSI after Joint Arthroplasty", summarizing the key findings from these studies, which cover a wide range of topics, including stringent preventive strategies, comprehensive diagnostic methods, and personalized treatment modalities. The authors concluded the editorial with their perspectives regarding the status quo of research in this field and future directions for research, such as the development of novel antibiotics, biofilm research, patient-specific risk factors, and the integration of technological advancements (such as machine learning and artificial intelligence) into clinical practice. The authors emphasized the need for continued research, interdisciplinary collaboration, and the application of innovative technologies to enhance patient outcomes and mitigate the burden of these infections on healthcare systems.

Dexmedetomidine Attenuates Inflammation in Elderly Patients Following Major Hepatobiliary and Pancreatic Surgery: A Randomized Clinical Trial.

Background: Dexmedetomidine (Dex) may have anti-inflammatory properties and potentially reduce the incidence of postoperative organ injury. Objective: To investigate whether Dex protects pulmonary and renal function via its anti-inflammatory effects in elderly patients undergoing prolonged major hepatobiliary and pancreatic surgery. Design and Setting: Between October 2019 and December 2020, this randomized controlled trial was carried out at a tertiary hospital in Chongqing, China. Patients: 86 patients aged 60-75 who underwent long-duration (> 4 hrs) hepatobiliary and pancreatic surgery without significant comorbidities were enrolled and randomly assigned into two groups at a 1:1 ratio. Interventions: Patients were given either Dex or an equivalent volume of 0.9% saline (Placebo) with a loading dose of 1 µg kg-1 for 10 min, followed by 0.5 µg kg-1 hr-1 for maintenance until the end of surgery. Main Outcome Measures: The changes in serum concentrations of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were primary outcomes. Results: At one hour postoperatively, serum IL-6 displayed a nine-fold increase (P<0.05) in the Placebo group. Administration of Dex decreased IL-6 to 278.09 ± 45.43 pg/mL (95% CI: 187.75 to 368.43) compared to the Placebo group (P=0.019; 432.16 ± 45.43 pg/mL, 95% CI: 341.82 to 522.50). However, no significant differences in TNF-α were observed between the two groups. The incidence of postoperative acute kidney injury was twice as high in the Placebo group (9.30%) compared to the Dex group (4.65%), and the incidence of postoperative acute lung injury was 23.26% in the Dex group, lower than that in the Placebo group (30.23%), although there was no statistical significance between the two groups. Conclusion: Dex administration in elderly patients undergoing major hepatobiliary and pancreatic surgery reduces inflammation and potentially protects kidneys and lungs. Registration: Chinese Clinical Trials Registry, identifier: ChiCTR1900024162, on 28 June 2019.

Effects of Laser Treatment of Terbium-Doped Indium Oxide Thin Films and Transistors.

In this study, a KrF excimer laser with a high-absorption coefficient in metal oxide films and a wavelength of 248 nm was selected for the post-processing of a film and metal oxide thin film transistor (MOTFT). Due to the poor negative bias illumination stress (NBIS) stability of indium gallium zinc oxide thin film transistor (IGZO-TFT) devices, terbium-doped Tb:In2O3 material was selected as the target of this study. The XPS test revealed the presence of both Tb3+ and Tb4+ ions in the Tb:In2O3 film. It was hypothesized that the peak of the laser thermal effect was reduced and the action time was prolonged by the f-f jump of Tb3+ ions and the C-T jump of Tb4+ ions during the laser treatment. Studies related to the treatment of Tb:In2O3 films with different laser energy densities have been carried out. It is shown that as the laser energy density increases, the film density increases, the thickness decreases, the carrier concentration increases, and the optical band gap widens. Terbium has a low electronegativity (1.1 eV) and a high Tb-O dissociation energy (707 kJ/mol), which brings about a large lattice distortion. The Tb:In2O3 films did not show significant crystallization even under laser energy density treatment of up to 250 mJ/cm2. Compared with pure In2O3-TFT, the doping of Tb ions effectively reduces the off-state current (1.16 × 10-11 A vs. 1.66 × 10-12 A), improves the switching current ratio (1.63 × 106 vs. 1.34 × 107) and improves the NBIS stability (ΔVON = -10.4 V vs. 6.4 V) and positive bias illumination stress (PBIS) stability (ΔVON = 8 V vs. 1.6 V).

G-CSF/SCF exert beneficial effects via anti-apoptosis in rabbits with steroid-associated osteonecrosis.

OBJECTIVES: Osteonecrosis is also known as avascular necrosis, and two types of cell death are included in the pathogenesis of osteonecrosis: necrosis and apoptosis. Apoptosis in the osteonecrosis of femoral head is thought to be the key determinant of glucocorticoid-induced cortical bone loss. The present study was implemented to evaluate the anti-apoptotic effect of Granulocyte colony-stimulating factor and stem cell factor (G-CSF/SCF) in rabbits with steroid-induced osteonecrosis. METHODS: In the experiment, osteonecrosis was induced by low-dose lipopolysaccharide and subsequent pulsed high-dose methylprednisolone. Rabbits in preventive medicine group were treated with 100 µg/kg/d G-CSF and 25 µg/kg/d SCF. Then hematological and histomorphometric methods were used to investigate the treatment effects of osteonecrosis. Apoptosis was assessed via quantitative TUNEL staining and activated caspase-3 immunostaining and immunoblotting. RESULTS: The results showed that G-CSF/SCF treatment could increase the secretion of serum osteocalcin, but inhibit the expression of serum tartrate-resistant acid phosphatase (TRAP5b). The incidence of osteonecrosis was significantly decreased in Preventive group when compared with Steroid group (42.1% vs. 88.2%). Histomorphometric analysis showed that G-CSF/SCF pre-disposal treatment was able to increase trabecular mineral appositional rate (MAR) and bone formation rate (BFR). Quantitative TUNEL and activated caspase-3 levels showed lower apoptosis in the Preventive group. CONCLUSIONS: In conclusion, G-CSF/SCF treatment could inhibit caspase-3-dependent apoptosis in osteocytes to exert beneficial effects in preventing steroid-induced ON in rabbit models.

Promotion of chondrogenesis of marrow stromal stem cells by TGF-ß3 fusion protein in vivo. [corrected].

The purpose of this study was to investigate the repair of the osteoarthritis(OA)-induced cartilage injury by transfecting the new TGF-ß3 fusion protein (LAP-MMP-mTGF-ß3) with targeted therapy function into the bone marrow-derived mesenchymal stem cells (MSCs) in rats. The recombinant of pIRES-EGFP-MMP was constructed by combination of DNA encoding MMP enzyme cutting site and eukaryotic expression vector pIRES-EGFP. LAP and mTGF-ß3 fragments were obtained from rat embryos by RT-PCR and inserted into the upstream and downstream of MMP from pIRES-EGFP-MMP respectively, so as to construct the recombinant plasmid of pIRES-EGFP-LAP-MMP-mTGF-ß3. pIRES-EGFP-LAP-MMP-mTGF-ß3 was transfected into rat MSCs. The genetically modified MSCs were cultured in medium with MMP-1 or not. The transfected MSCs were transplanted in the rat OA models. The OA animal models were surgically induced by anterior cruciate ligament transaction (ACLT). The pathological changes were observed under a microscope by HE staining, Alcian blue, Safranin-fast Green and graded by Mankin's scale. pIRES-EGFP-LAP-MMP-mTGF-ß3 was successfully constructed by means of enzyme cutting and sequencing, and the mTGF-ß3 fusion protein (39 kD) was certified by Western blotting. Those genetically modified MSCs could differentiate into chondrocytes induced by MMP and secrete the relevant-matrix. The transfected MSCs could promote chondrogenesis and matrix production in rat OA models in vivo. It was concluded that a new fusion protein LAP-MMP-mTGF-ß3 was constructed successfully by gene engineering, and could be used to repair the OA-induced cartilage injury.

Induction of chondrogenesis of adipose-derived stem cells by novel recombinant TGF-ß3 fusion protein.

A new type of TGF-ß3 fusion protein with targeted therapy function was constructed, and its feasibility and target specificity of inducing chondrogenesis were investigated by transfecting LAP-MMP-mTGF-ß3 gene into adipose-derived stem cells (ADSCs). The recombinant pIRES-EGFP-MMP was constructed by inserting the sense and antisense DNA of encoding the amino acid of the synthetic MMP enzyme cutting site into the eukaryotic expression vector pIRES-EGFP. LAP and mTGF-ß3 fragments were obtained by using RT-PCR and inserted into the upstream and downstream of MMP from pIRES-EGFP-MMP respectively, and the recombinant plasmid of pIRES-EGFP-LAP-MMP-mTGF-ß3 was constructed, which was transferred to ADSCs. The ADSCs were cultured and divided in three groups: experimental group (MMP group), negative control group (no MMP) and non-transfection group. The morphological changes were observed microscopically, and the expression of proteoglycan and type II collagen (ColII) was detected by using Alcian blue staining and immunohistochemistry staining at 7th, 14th and 21st day after culture. The recombinant plasmid of pIRES-EGFP-LAP-MMP-mTGF-ß3 was correctly constructed by methods of enzyme cutting and sequencing analysis. The mTGF-ß3 fusion protein was successfully expressed after transfection, and in the presence of the MMP, active protein mTGF-ß3 was generated, which significantly promoted differentiation of ADSCs into chondrocytes and the expression of cartilage matrix. The novel fusion protein LAP-MMP-mTGF-ß3 can targetedly induce differentiation of ADSCs into chondrocytes, which would open up prospects for target therapy of cartilage damage repair in future.