Unilateral Bi/Multi-Portal Endoscopy for the Treatment of Complicated Lumbar Degenerative Diseases with Utilization of Uniaxial Spinal Endoscope, Instead of Arthroscope: Technique Note and Clinical Results.

Objective: This article aims to discuss a novel surgical strategy, referred to as unilateral bi/multi-portal endoscopy (UME), which used a uniaxial spinal endoscope instead of an arthroscope in the traditional unilateral biportal endoscopy (UBE) surgical procedure in our study of the treatment of complicated lumbar degenerative diseases. Methods: This retrospective study included 42 patients diagnosed with high-migrated lumbar disc herniation and bilateral spinal stenosis who underwent UME surgery from January 2021 to December 2021. Patients included 20 men and 22 women, with an average age of 55.97±14.92 years. The average follow-up period was 13.19 months. The demographic data, operation time (min), and complications were recorded and analyzed. The visual analogue scale (VAS), Oswestry Disability Index (ODI) scores were used to evaluate the surgical outcomes. Three-dimensional CT scans and MRI were conducted to evaluate the radiographic improvement. Results: A total of 26 patients were diagnosed with lumbar disc herniation and 16 with lumbar spinal stenosis. All 42 patients underwent UME surgery and achieved satisfactory outcomes. The operation time was 154.46±46.09 min. The average follow-up time was 13.19±1.33 months. The preoperative back pain (VAS-Back) and the last follow-up VAS-Back were 3.84±1.00 and 0.70±0.46, respectively (P < 0.05). The preoperative leg pain (VAS-Leg) and the last follow-up VAS-Leg were 6.46±1.08 and 1.03±0.64, respectively (P <0.05). Significant differences existed between preoperative ODI scores (58.70±11.22%) and the last follow-up ODI scores (9.24±3.04%; P<0.05). All patients achieved significant pain relief and functional improvement after the surgery. No severe complications occurred, except for two cases of postoperative dysesthesia and one case suffered from vertebral compression fractures induced by a postoperative accidental injury. Symptoms of numbness disappeared within one week with treatment using dexamethasone and neurotrophic drugs. The vertebral fracture case recovered with percutaneous kyphoplasty treatment. Conclusion: This study suggests that UME is a promising treatment strategy for high-migrated disc herniation and bilateral spinal stenosis.

Antitumor effects of the small molecule DMAMCL in neuroblastoma via suppressing aerobic glycolysis and targeting PFKL.

BACKGROUND: Neuroblastoma (NB) is a common solid malignancy in children that is associated with a poor prognosis. Although the novel small molecular compound Dimethylaminomicheliolide (DMAMCL) has been shown to induce cell death in some tumors, little is known about its role in NB. METHODS: We examined the effect of DMAMCL on four NB cell lines (NPG, AS, KCNR, BE2). Cellular confluence, survival, apoptosis, and glycolysis were detected using Incucyte ZOOM, CCK-8 assays, Annexin V-PE/7-AAD flow cytometry, and Seahorse XFe96, respectively. Synergistic effects between agents were evaluated using CompuSyn and the effect of DMAMCL in vivo was evaluated using a xenograft mouse model. Phosphofructokinase-1, liver type (PFKL) expression was up- and down-regulated using overexpression plasmids or siRNA. RESULTS: When administered as a single agent, DMAMCL decreased cell proliferation in a time- and dose-dependent manner, increased the percentage of cells in SubG1 phase, and induced apoptosis in vitro, as well as inhibiting tumor growth and prolonging survival in tumor-bearing mice (NGP, BE2) in vivo. In addition, DMAMCL exerted synergistic effects when combined with etoposide or cisplatin in vitro and displayed increased antitumor effects when combined with etoposide in vivo compared to either agent alone. Mechanistically, DMAMCL suppressed aerobic glycolysis by decreasing glucose consumption, lactate excretion, and ATP production, as well as reducing the expression of PFKL, a key glycolysis enzyme, in vitro and in vivo. Furthermore, PFKL overexpression attenuated DMAMCL-induced cell death, whereas PFKL silencing promoted NB cell death. CONCLUSIONS: The results of this study suggest that DMAMCL exerts antitumor effects on NB both in vitro and in vivo by suppressing aerobic glycolysis and that PFKL could be a potential target of DMAMCL in NB.

Handgrip strength is positively associated with bone mineral density in middle and aged adults: results from NHANES 2013-2014.

Few studies have examined the association between handgrip strength and BMD in specific subgroups. Therefore, we examined the associations of handgrip strength with BMD aged ≥ 40 years and found that handgrip strength is associated with BMD which is independent of BMI, physical activity, and other potential confounders. PURPOSE: Previous studies have revealed that handgrip strength is a measure of muscular fitness and is associated with fracture and bone mineral density (BMD) in adolescents and adults, with conflicting results. In addition, few studies have examined the association between handgrip strength in predefined subgroups such as sex, age, and physical activity in a whole population. METHODS: We examined the associations of handgrip strength with BMD in 2720 adults (1359 men and 1361 women) aged ≥ 40 years (mean age, 58.6 ± 11.8 years) from the National Health and Nutrition Examination Survey (NHANES) 2013-2014. NHANES collects data via household interviews and direct standardized physical examinations conducted in specially equipped mobile examination centers. The date of final data collection was 2014 and the present data analysis was conducted in January to February 2020. RESULTS: Handgrip strength was significantly associated with total femur (r = 0.482, P < 0.001) and femoral neck BMD (r = 0.427, P < 0.001) among all participants, respectively. After adjustment for age, sex, race, body mass index (BMI), physical activity, smoking, history of diabetes, history of hypertension, and history of high cholesterol, each unit (1 SD) of BMI-adjusted handgrip strength was positively associated with 0.026 g/cm2 increase in total femur BMD (P < 0.001) and 0.027 g/cm2 increase in femoral neck BMD (P < 0.001). There was a significant increasing trend in total femur and femoral BMD as handgrip strength increased from the lowest quartile to the highest quartile (P for trend < 0.001). For subgroup analysis, there were no significant interaction effects of handgrip strength with BMD between predefined subgroups (all P > 0.05). CONCLUSIONS: High level of handgrip strength is associated with increased BMD. The association is independent of BMI, physical activity, and other potential confounders.

Protective effect and mechanisms of action of Mongolian medicine Sulongga-4 on pyloric ligation-induced gastroduodenal ulcer in rats.

BACKGROUND: Sulongga-4 (SL-4) is a herbal formula used in traditional Mongolian medical clinics for the treatment of peptic ulcers and gastroenteritis, even though its pharmacological mechanism has not been well characterized. AIM: To evaluate the protective effect and identify the mechanisms of action of SL-4 on gastroduodenal ulcer induced by pyloric ligation (PL) in rats. METHODS: PL was performed to induce gastric and duodenal ulcers in rats, which were then treated with oral SL-4 (1.3, 2.6, or 3.9 g/kg per day) for 15 d. PL-induced gastroduodenal ulceration. Therapeutic effects were characterized by pathological and histological evaluations and inflammatory indicators were analyzed by enzyme-linked immunosorbent assay. Microarray analyses were conducted to identify gene expression profiles of gastroduodenal tissue in PL rats with or without SL-4 treatment. The candidate target genes were selected and verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: SL-4 decreased histopathological features in the PL-induced ulcerated rats. SL-4 significantly (P < 0.05) decreased expression of tumor necrosis factor-α, interleukin (IL)-1ß, IL-6, endotoxin, platelet-activating factor, and increased prostaglandin E2 and epidermal growth factor in ulcer tissue. Microarray analysis was used to identify a panel of candidate target genes for SL-4 acting on PL-induced ulceration. Genes included some complement and coagulation cascade and retinol metabolism pathways that are closely associated with inflammatory responses and gastric mucosal protective mechanisms. qRT-PCR showed that altered expression of the selected genes, such as CYP2b2, UGT2b1, A2m, and MASP1 was consistent with the microarray results. CONCLUSION: SL-4 exerts protective effects against PL-induced gastroduodenal ulcers via reducing inflammatory cytokines and elevating expression of gastric acid inhibitory factors. Downregulation of CYP2b2 and UGT2b1 genes in retinol metabolism and upregulation of A2m and MASP1 genes in the complement and coagulation cascades pathways are possibly involved in SL-4-mediated protection against gastroduodenal ulcer.

Novel agent DMAMCL suppresses osteosarcoma growth and decreases the stemness of osteosarcoma stem cell.

Osteosarcoma (OS) is the most common primary malignancy of bone that mostly affects children, adolescents, and young people. Despite advances have been made in multimodal therapy of OS, the long-term survival rate has reached a plateau, and the main obstacles are bad response to chemotherapy and gained chemoresistance. In this study, we tested the therapeutic effect of a newly reported drug, DMAMCL, on OS. Five human OS cell lines (143B, MNNG, MG63, Saos-2, U-2OS), and the mouse fibroblast cell line (NIH3T3) and human retinal epithelial cell (ARPE19) were used. The anti-tumor effect of DMAMCL was studied by MTS assay or IncuCyte-Zoom (in vitro), and Xenograft-mice-model (in vivo). Changes of cell cycle, apoptotic cells, caspase3/7 activities, and stemness after DMAMCL treatment were investigated. BAX siRNAs were used to knockdown the expression of BAX. Expressions of CyclinB1, CDC2, BCL-2 family, PARP, CD133, and Nanog were measured by Western Blotting. DMAMCL-induced dose-dependent OS cell death in vitro, and suppressed tumor growth and extended the survival of xenograft-bearing mice. DMAMCL-induced G2/M phase arrest in vitro, and apoptosis both in vitro and in vivo. Down-regulation of BAX expression attenuated the DMAMCL-induced OS cell death in vitro. We also found that DMAMCL inhibited the stemness in OS cells. These results indicated that DMAMCL possess therapeutic value in OS and may be a promising candidate for the new drug discovery for OS therapy.

Activating transcription factor 6 (ATF6) negatively regulates Polo-like kinase 4 expression via recruiting C/EBPß to the upstream-promoter during ER stress.

Polo-like kinase 4 (PLK4) is a member of the serine/threonine protein kinase family involved in cell-cycle regulation and cellular response to stresses. However, the alteration of PLK4 in response to endoplasmic reticulum (ER) stress has not been well described. In the present study, we focused on the regulation of PLK4 regulation in response to ER stress. PLK4 expression was dramatically reduced under ER stress induced by brefeldin A (BFA), tunicamycin (TM), or thapsigargin (TG) and down regulation of PLK4 expression was dependent on activating transcription factor 6 (ATF6) and CCAAT/enhancer-binding protein ß (C/EBPß). Luciferase activity analysis of the truncated PLK4 promoter indicated that region from -1343 to -1250 of the PLK4 promoter was sensitive to BFA or TG. Additionally, ChIP and ChIP Re-IP assays showed that ATF6 and C/EBPß were assembled on the same region of Plk4 promoter. Notably, we identified one C/EBPß responsive element at position -1284, to which ATF6 or C/EBPß binding was enhanced by BFA or TG under in vitro and in vivo conditions. Finally, overexpression of PLK4 inhibits apoptosis and promotes cell proliferation in response to ER stress. In summary, these results demonstrated that ER stress plays a crucial role in PLK4 expression. ATF6 may upregulate DNA-binding affinities after BFA treatment, via recruiting C/EBPß to the upstream promoter of PLK4. These findings may contribute to the understanding of the molecular mechanism of PLK4 regulation.

Cyclic GMP-AMP synthase is essential for cytosolic double-stranded DNA and fowl adenovirus serotype 4 triggered innate immune responses in chickens.

Cyclic GMP-AMP (cGAMP) synthase (cGAS) is a predominant DNA sensor inducing the activation of the innate immune responses that produce proinflammatory cytokines and type I interferons, which has been well-investigated in mammals. However, chicken cGAS (chcGAS), which participates in avian innate immunity, has not been well-investigated. Here, we cloned the complete open reading frame sequence of chcGAS. Multiple sequence alignment and phylogenetic analysis revealed that chcGAS was homologous to mammalian cGAS. The chcGAS mRNA was highly expressed in the bone marrow and ileum. The subcellular localization of chcGAS was mainly in the cytoplasm, and partial co-localization was observed in the endoplasmic reticulum. Through overexpression and RNA interference, we demonstrated that chcGAS responded to exogenous dsDNA, HS-DNA, and poly(dA:dT), and to self dsDNA from the DNA damage response, thereby triggering the activation of STING/TBK1/IRF7-mediated innate immunity in both chicken embryonic fibroblasts and chicken liver cancer cells. Furthermore, downregulation of chcGAS enhanced the infection of fowl adenovirus serotype 4 in LMH cells. Our results demonstrated that chcGAS was an important cytosolic DNA sensor activating innate immune responses and may shed light on a strategy for preventing infectious diseases in the poultry industry.

The anti-tumor growth effect of a novel agent DMAMCL in rhabdomyosarcoma in vitro and in vivo.

BACKGROUND: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children with poor survival. New treatment approaches are urgently needed to improve treatment efficacy in RMS patients. DMAMCL is a novel agent from Asteraceae family that has been tested in phase I clinical trials in adult glioma in Australia. METHODS: Five RMS cell lines (RD, RH18, RH28, RH30 and RH41) were used. The in vitro anti-tumor effect of DMAMCL, alone or in combination with VCR or Epirubicin, was studied using MTS assay or IncuCyte-Zoom cell confluency assay, and further validated by xenograft-mouse model in vivo. Changes in caspase-3/7 activity, cell-cycle progression and generation of ROS after DMAMCL treatment were investigated. Bim mRNA expression was measured by RT-qPCR, and protein expressions of Bim and phosphorylated-NF-κB(p65) by Western blotting. Small interfering RNAs (siRNA) of Bim were used to study the role of Bim in DMAMCL-induced cell death. RESULTS: In vitro, DMAMCL treatment induced a dose-dependent increase in cell death that could be blocked by pan-caspase-inhibitor-Z-VAD-fmk in five RMS cell lines. The percent of cells in SubG1 phase and activities of caspase-3/7 increased after DMAMCL treatment; The combination of DMAMCL with VCR or Epirubicin significantly increased cell death compared to each reagent alone. In vivo, DMAMCL(75 mg/kg or 100 mg/kg) inhibited tumor growth and prolonged survival of mice bearing xenograft RMS tumors (RD, RH18, RH30, RH41). Compared to treatment with DMAMCL or VCR, a combination of two reagents caused significant inhibition of tumor growth (RD, RH41), even after treatment termination. The expression of Bim increased at protein level after DMAMCL treatment both in vitro and in vivo. The expression of p-NF-κB(p65) had a transient increase and the generation of ROS increased after DMAMCL treatment in vitro. Transfection of Bim siRNA into RMS cells blocked the DMAMCL-induced increase of Bim and partially attenuated the DMAMCL-induced cell death. CONCLUSION: DMAMCL had an anti-tumor growth effect in vitro and in vivo that potentially mediated by Bim, NF-κB pathway and ROS. A combination of DMAMCL with chemotherapeutic drugs significantly increased the treatment efficacy. Our study supports further clinical evaluation of DMAMCL in combination with conventional chemotherapy.

Myostatin knockout induces apoptosis in human cervical cancer cells via elevated reactive oxygen species generation.

Myostatin (Mstn) is postulated to be a key determinant of muscle loss and cachexia in cancer. However, no experimental evidence supports a role for Mstn in cancer, particularly in regulating the survival and growth of cancer cells. In this study, we showed that the expression of Mstn was significantly increased in different tumor tissues and human cancer cells. Mstn knockdown inhibited the proliferation of cancer cells. A knockout (KO) of Mstn created by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) 9 (CRISPR/Cas9) induced mitochondria-dependent apoptosis in HeLa cells. Furthermore, KO of Mstn reduced the lipid content. Molecular analyses demonstrated that the expression levels of fatty acid oxidation-related genes were upregulated and then increased rate of fatty acid oxidation. Mstn deficiency-induced apoptosis took place along with generation of reactive oxygen species (ROS) and elevated fatty acid oxidation, which may play a role in triggering mitochondrial membrane depolarization, the release of cytochrome c (Cyt-c), and caspase activation. Importantly, apoptosis induced by Mstn KO was partially rescued by antioxidants and etomoxir, thereby suggesting that the increased level of ROS was functionally involved in mediating apoptosis. Overall, our findings demonstrate a novel function of Mstn in regulating mitochondrial metabolism and apoptosis within cancer cells. Hence, inhibiting the production and function of Mstn may be an effective therapeutic intervention during cancer progression and muscle loss in cachexia.

Leonurine hydrochloride promotes osteogenic differentiation and increases osteoblastic bone formation in ovariectomized mice by Wnt/ß-catenin pathway.

Leonurine hydrochloride (LH) is a synthetic chemical compound derived from leonurine that can be extracted from Leonurus sibiricus and possesses antioxidant, anti-apoptosis, and neuroprotective activities. In previous studies, LH has been demonstrated to attenuate osteoclast activity and prevent bone loss. However, it is unknown whether LH accelerates bone formation and promotes osteogenic differentiation. We systematically examined the effects of LH on ovariectomized-induced osteoporotic mice and the MC3T3-E1 osteoblastic cell line. The results revealed that LH enhanced differentiation of MC3T3-E1 cells, with a dose-dependent increase in alkaline phosphatase (ALP) activity. Moreover, LH upregulated osteogenesis-related gene expression, including osterix, alpha 1 type 1 collagen, runt-related transcription factor 2 (Runx2) and ALP, as shown by quantitative reverse transcription-polymerase chain reaction analysis. At the same time, elevated expression of low-density lipoprotein receptor-related protein 5 and ß-catenin mRNA was detected in the Wnt/ß-catenin pathway. A western blot analysis revealed that LH dose-dependently increased the expression of Runx2 and ß-catenin, and promoted phosphorylation of glycogen synthase kinase-3ß in vitro. The in vivo results showed that administering LH (15 mg/kg/d) for 8 weeks alleviated destruction of the trabecular microstructure caused by osteoporosis. LH increased the bone mineral density and trabecular number, decreased trabecular separation according to a micro-computed tomography scan. In addition, LH enhanced the expression of ß-catenin and Runx2 in vivo. In conclusion, LH promoted osteogenic differentiation and bone formation in vivo and in vitro, which alleviated osteoporosis through activation of the Wnt/ß-catenin pathway.

CHOP negatively regulates Polo-like kinase 2 expression via recruiting C/EBPα to the upstream-promoter in human osteosarcoma cell line during ER stress.

Polo-like kinase 2 (Plk2) is a member of the serine/threonine protein kinase family involved in cell-cycle regulation and cellular response to stresses. However, the alteration of Plk2 in response to endoplasmic reticulum (ER) stress has not been well described. In the present study, we focused on the regulation of Plk2 regulation in response to ER stress. Plk2 expression was dramatically decreased under ER stress induced by brefeldin A (BFA), thapsigargin (TG), or tunicamycin (TM), and this down regulation of Plk2 expression was dependent on activating transcription factor 4 (ATF4) and C/EBP homology protein (CHOP). Luciferase activity analysis of the truncated Plk2 promoter indicated that regions from -2506 to -1806 and from -1002 to -830 of the Plk2 promoter were sensitive to BFA. Additionally, ChIP and ChIP Re-IP assays showed that CHOP and C/EBPα were assembled on the same region of Plk2 promoter. Notably, we identified two C/EBPα responsive elements at positions -2002 and -948, to which C/EBPα or CHOP binding was enhanced by BFA under in vitro and in vivo conditions. Finally, overexpression of Plk2 inhibits cell apoptosis and promotes cell proliferation in response to ER stress. In summary, these results demonstrated that ER stress plays a crucial role in Plk2 expression. CHOP may up-regulate DNA-binding affinities after BFA treatment, via recruiting C/EBPα to the upstream-promoter of Plk2. These findings may contribute to the understanding of the molecular mechanism of Plk2 regulation.

Curcumin alleviates glucocorticoid-induced osteoporosis by protecting osteoblasts from apoptosis in vivo and in vitro.

Curcumin, an active component of the rhizomes of Curcumin longa L., possesses broad anti-inflammation and anti-cancer properties. Curcumin was previously reported to be capable of protecting ovariectomized rats against osteoporosis. However, the effect of curcumin on glucocorticoid-induced osteoporosis (GIO) is not yet clear. The present study investigated the effects of curcumin on dexamethasone (Dex)-induced osteoporosis in vivo and Dex-induced osteoblast apoptosis in vivo and in vitro. The GIO rat model was induced by subcutaneous injection of Dex for 60 days and verified to be successful as evidenced by the significantly decreased bone mineral density (BMD) determined using dual X-ray absorptiometry. Subsequently, curcumin administration (100 mg/kg) for 60 days obviously increased BMD and bone-alkaline phosphatase, decreased carboxy-terminal collagen cross links, enhanced bone mechanical strength, and improved trabecular microstructure, thereby alleviating Dex-induced osteoporosis. Mechanically, curcumin remarkably reversed Dex-induced femoral osteoblast apoptosis in vivo. In cultured primary osteoblasts, pretreatment with curcumin concentration-dependently decreased the number of Dex-induced apoptotic osteoblasts by down-regulating the ratio of Bax/Bcl-2 as well as the levels of cleaved caspase-3 and cleaved poly ADP-ribose polymerase (PARP). Moreover, curcumin pretreatment activated extracellular signal regulated kinase (ERK) signalling in Dex-induced osteoblasts by up-regulating the expression level of p-ERK1/2. Taken together, our study demonstrated that curcumin could ameliorate GIO by protecting osteoblasts from apoptosis, which was possibly related to the activation of the ERK pathway. The results suggest that curcumin may be a promising drug for prevention and treatment of GIO.

[Chemical Constituents in Petroleum Ether Extract of Mongolian Medicine Halenia corniculata].

OBJECTIVE: To study the chemical constituents of Mongolian medicine Halenia corniculata. METHODS: Positive phase and reversed phase silica gel, as well as Sephadex LH-20 methods were used to separate and purify. The structure of the isolated constituents was identified according to the NMR spectroscopy data and the literature data. RESULTS: Nine compounds were isolated from 95% ethanol extracts of petroleum ether part of Halenia corniculata and identified as: 1-hydroxy-2,3,4,6-tetramethoxyxanthone (1), 1-hydroxy-2,3, 5-trimethoxyxanthone (2) 1-hydroxy-3,7-dimethoxyxanthone (3), 1-hydroxy-3,5,6,7,8-pentamethoxyxanthone (4), 1-hydroxy-2,3,4, 7-tetramethoxyxanthone (5), 1-hydroxy-3,5-dimethoxyxanthone (6),1-hydroxy-2,3,4,5,7-pentamethoxyxanthone (7), palmitic acid (8) and ß-sitosterol (9). CONCLUSION: Compounds 3, 4 and 8 are isolated from this genus for the first time, Compound 1 is isolated from this plant for the first time.

Recombinant human bone morphogenetic protein-2 versus autogenous iliac crest bone graft for lumbar fusion: a meta-analysis of ten randomized controlled trials.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) as a substitute for iliac crest bone graft (ICBG) has been increasingly widely used in lumbar fusion. It has been proven non-inferior in fusion success and clinical outcomes when compared with ICBG. However, increasingly, some potentially uncommon and serious complications associated with the use of rhBMP-2 have been of great concern to surgeons. The purpose of this study was to determine whether rhBMP-2 could be considered an effective and, more importantly, a relatively safe substitute for ICBG in lumbar fusion. METHODS: Randomized controlled trials that compared rhBMP-2 with ICBG for lumbar fusion were identified by computer and manual searching. The risk of bias and clinical relevance of the included studies were assessed. Publication bias was explored using funnel plot and statistical tests (Egger's test and Begg's test). Meta-analyses were performed using the Cochrane systematic review methods. RESULTS: Ten randomized controlled trials (1,342 patients) met the inclusion criteria. Compared with ICBG, the use of rhBMP-2 significantly decreased the risk of fusion failure at all time intervals (6 months: p < 0.0001, RR = 0.55, 95 % CI = 0.42-0.72; 12 months: p = 0.0003, RR = 0.53, 95 % CI = 0.37-0.75; 24 months: p < 0.00001, RR = 0.31, 95 % CI = 0.21-0.46) and the rate of reoperation (p = 0.0001, RR = 0.52, 95 % CI = 0.37-0.72). There was no statistical difference in clinical improvement on the Oswestry Disability Index, although a favorable trend in the rhBMP-2 group was found (p = 0.12, RR = 0.73, 95 % CI = 0.49-1.08). Subgroup analyses stratified by the type of surgical procedure yielded similar results. Owing to the different data formats, meta-analysis on adverse events was not performed. CONCLUSION: RhBMP-2 was superior to the ICBG for achieving fusion success and avoiding reoperation. However, evidence from the Food and Drug Administration document and subsequent independent studies has demonstrated that original, industry-sponsored trials underestimated rhBMP-2-related adverse events. There are still security risks in the use of rhBMP-2.

[Expression and localization of ArgBP2 in osteosarcoma MG-63 cells].

AIM: To construct an eukaryotic expression vector GFP-hArgBP2 and identify the expression and localization of hArgBP2 in osteosarcoma MG-63 cells. METHODS: Using pcDNA3.1-hArgBP2 as a template, we obtained human ArgBP2 coding sequence by polymerase chain reaction (PCR) amplification and cloned it into the eukaryotic expression vector. The insert was identified by restriction enzyme digestion and DNA sequencing. GFP-hArgBP2 was transfected into osteosarcoma MG-63 cells and examined by Western blot. The localization of GFP-hArgBP2 in MG-63 cells was also observed with laser scanning confocal microscopy. hArgBP2 protein was purified by immunoprecipitation assay. RESULTS: hArgBP2 was successfully constructed into the expressing vector pEGFP-C1. The length of the fragment identified by restriction enzyme digestion was 1 935 bp. The expression of GFP-hArgBP2 fusion protein with a molecular weight of 97 000Da was detected by Western blot and pulled down by GFP antibody, and its localization was in the cytoplasm and perinucleus in MG-63 cells. CONCLUSION: The recombinant plasmid of hArgBP2 gene was successfully constructed. The expression of GFP-hArgBP2 fusion protein was identified and pulled down by GFP antibody. GFP-hArgBP2 was mainly localized in the cytoplasm and perinucleus of MG-63 cells.

Upregulation of Polo-like kinase 2 gene expression by GATA-1 acetylation in human osteosarcoma MG-63 cells.

Polo-like kinase 2 (Plk2) is a member of the serine/threonine protein kinase family involved in cell-cycle regulation and cellular response to stresses. It is of great interest to investigate the molecular mechanisms that control the expression of Plk2. Here, using real-time PCR and Western blot assays, we show that trichostatin A (TSA), a histone deacetylase inhibitor, upregulated Plk2 mRNA and protein expression in the human osteosarcoma MG-63 cell line. Luciferase activity analysis of the truncated Plk2 promoter indicated that the region from -1220 to -830 of the Plk2 promoter was sensitive to TSA. Moreover, using the electrophoresis mobility shift assay and chromatin immunoprecipitation assay, we identified two GATA-1 responsive elements at positions -1051 and -949, to which GATA-1 binding was enhanced by TSA under in vitro and in vivo conditions. Immunoprecipitation and Western blot showed that the levels of acetylated GATA-1 were increased with TSA in MG-63 cells, consistent with their binding affinities to the GATA-1 responsive elements. In summary, these data demonstrate that acetylation plays a crucial role in Plk2 expression and acetylation of GATA-1 by TSA treatment may upregulate their DNA-binding affinities, resulting in the activation of Plk2 promoter. These results may contribute to the understanding of the molecular mechanism of Plk2 regulation.

[Research progress of C terminal propeptide of collagen type II].

OBJECTIVE: To review the research progress of C terminal propeptide of collagen type II (CTX-II), a osteoarthritis (OA) biomarker. METHODS: Domestic and international literature about CTX-II was reviewed extensively and summarized. RESULTS: CTX-II is investigated broadly and has the best performance of all currently available biomarkers. CTX-II is a truly useful biomarker for early diagnosis, prognosis, and measurement of treatment response in OA. CONCLUSION: Single CTX-II may be not sufficient for early diagnosis and prognosis of OA, so a combination of CTX-II and other biomarkers or diagnosis methods is needed.

[Clinical study of healing abutment on sealing socket and preservation of the gingival natural profile in single-tooth immediate implantation].

OBJECTIVE: To investigate the clinical results of use of healing abutment for sealing socket and preserving the gingival natural profile in single-tooth immediate implantation. METHODS: The osteotomy site was prepared with pilot drill directed by the periodontal probe on palatal wall of the socket,and 31 single-implant were placed into fresh sockets with flapless surgery and filled with Bio-oss. Healing abutments were simultaneously fitted on implants and ceramic crowns fabricated three months post-operation. Scientific assessment of soft tissue contour was carried out by interdental papillae index immediately after restorations. RESULTS: One implant was lost at second week after operation. The remaining 30 implants gained perfect osseointegration and the gingival natural profile was preserved completely. CONCLUSIONS: Sealing socket and preserving the gingival natural profile by healing abutment is a predictable, safe and practical method with good aesthetic results in single-tooth immediate implantation.