The combined effect of fire and nitrogen addition on biodiversity and herbaceous aboveground productivity in a coastal shrubland

Introduction

Fire and nitrogen (N) deposition each impact biodiversity and ecosystem productivity. However, the effect of N deposition on ecosystem recovery after fire is still far from understood, especially in coastal wetlands.

Methods

We selected a typical coastal shrubland to simulate three N deposition levels (0, 10, and 20 g N m-2 year-1) under two different burned conditions (unburned and burned) in the Yellow River Delta of North China. Soil properties, soil microbial biodiversity, shrub growth parameters, herbaceous biodiversity, and aboveground productivity were determined after experimental treatments for 1 year.

Results

We found that fire had a stronger influence on the ecosystem than N addition. One year after the fire, shrub growth had significantly decreased, while soil pH, soil electrical conductivity, herbaceous biodiversity, soil microbial biodiversity, and herbaceous aboveground productivity significantly increased. Conversely, a single year of N addition only slightly increased herbaceous aboveground productivity. The combined effect of fire and N addition was only significant for fungus biodiversity and otherwise had minimal influence. Interestingly, we found that herbaceous aboveground productivity was positively associated with fungal community diversity under unburned conditions but not in burned shrublands. Fire showed a great impact on soil parameters and biodiversity in the coastal wetland ecosystem even after a full year of recovery.

Discussion

Fire may also diminish the influence of several belowground factors on herbaceous aboveground productivity, which ultimately reduces recovery and stability. Appropriate N addition may be an effective way to improve the ecosystem productivity in a wetland dominated by shrub species.

S100A1 expression is increased in spinal cord injury and promotes inflammation, oxidative stress and apoptosis of PC12 cells induced by LPS via ERK signaling

Spinal cord injury (SCI) is a severe neurological disorder and the molecular mechanisms leading to its poor prognosis remain to be elucidated. S100A1, a mediator of Ca2+ handling of sarcoplasmic reticulum and mitochondrial function, operates as an endogenous danger signal (alarmin) associated with inflammatory response and tissue injury. The aim of the present study was to investigate the expression and biological effects of S100A1 in SCI. A rat model of SCI and a PC12 cell model of lipopolysaccharide (LPS)‑induced inflammation were established to examine S100A1 expression at the mRNA and protein levels. The inflammation level, which was mediated by S100A1, was determined based on inflammatory factor (IL‑1β, IL‑6 and TNF‑α) and anti‑inflammatory factor (IL‑10) expression. The effects of S100A1 on cellular oxidation and anti‑oxidation levels were observed by detecting the levels of reactive oxygen species, superoxide dismutase, catalase activities and nuclear factor erythroid 2‑related factor 2 expression. The protein levels of Bax, Bcl2 and cleaved caspase‑3 were used for the evaluation of the effects of S100A1 on apoptosis. Phosphorylated (p‑)ERK1/2 expression was used to evaluate the effects of S100A1 on ERK signaling. The results revealed that S100A1 expression was significantly upregulated in vivo and in vitro in the PC12 cell model of LPS‑inflammation. The silencing and overexpression of S100A1 helped alleviate and aggravate LPS‑induced inflammation, oxidative stress and apoptosis levels, respectively. S100A1 was found to regulate the ERK signaling pathway positively. An inhibitor of ERK signaling (MK‑8353) partially abolished the promoting effects of the overexpression of S100A1 on inflammation, oxidative stress damage and apoptosis. In conclusion, S100A1 expression was elevated in model of SCI and in the PC12 cell model of LPS‑induced inflammation. Furthermore, the overexpression/silencing S100A1 aggravated/mitigated the inflammation, oxidative stress damage and the apoptosis of LPS‑stimulated PC12 cells via the ERK signaling pathway. The present study revealed the mechanism of S100A1 in SCI, which provided a new theoretic reference for future research on SCI.

Ibuprofen on Proliferation and Apoptosis of Sarcoma Cells via PI3K/Akt/mTOR Signaling Pathway

Nowadays, there is a serious lack of information about the value-added apoptosis of sarcoma cells in China. Especially in clinical medicine, exploring the effect of ibuprofen on the growth and apoptosis of fibrosarcoma cells under the PI3K/Akt/mTOR signaling pathway can not only effectively prevent us in advance, but also be a great way to break through this field. The main purpose of this study was to investigate the effects of ibuprofen on the proliferation, cell cycle and apoptosis of fibrosarcoma cells through the PI3K/Akt/mTOR signaling pathway. We divided the HTl080 cell line into zero control group, control group and experimental group. The withering group was not inoculated with any cells, while the control group was only added with the same amount of culture medium, while the experimental group was added with 5,10,15,20 concentrations respectively. We found that the apoptosis rate of sarcoma cells in the control group increased from 5.66% to 7.12%, while the apoptosis rate of sarcoma cells in the experimental group increased significantly faster than that in the control group, with an overall increase of 7.16%, from 4.56% to 11.72%. Therefore, we can be surer that ibuprofen has a very good inhibitory effect on the proliferation, cell cycle and apoptosis of fibrosarcoma cells under the PI3K/Akt/mTOR signaling pathway. Therefore, when ibuprofen was injected into the body, it could not only observe the sarcoma cells well but also reflect the good inhibitory effect of ibuprofen on other substances in vivo under the PI3K/Akt/mTOR signaling pathway.

Peiminine Induces G0/G1-Phase Arrest, Apoptosis, and Autophagy via the ROS/JNK Signaling Pathway in Human Osteosarcoma Cells in Vitro and in Vivo

Aims: Peiminine has been reported to have various pharmacological properties, including anticancer activity. In this study, we investigated the effect of this alkaloid on osteosarcoma and explored the underlying mechanisms.

Methods: To evaluate the antiosteosarcoma effects of peiminine in vitro, cell viability was assessed by CCK-8 and live/dead assays; the effects of the drug on apoptosis and the cell cycle were examined by flow cytometry; the effects on cell migration and invasion were detected by wound healing and Transwell assays, respectively, while its effects on autophagy were observed by transmission electron microscopy and an LC3 fluorescent puncta formation assay. The role of autophagy in the peiminine-mediated effects in osteosarcoma cells was evaluated by CCK-8 assay and western blotting after the application of the autophagy inhibitor chloroquine. The effect of peiminine on reactive oxygen species (ROS) production was analyzed using fluorescence confocal microscopy and spectrophotometry. Additionally, peiminine-treated osteosarcoma cells were exposed to SP600125, a JNK inhibitor, and N-acetylcysteine, a ROS scavenger, after which the contribution of the ROS/JNK signaling pathway to osteosarcoma was assessed using cell viability and LC3 fluorescent puncta formation assays, flow cytometry, and western blotting. A xenograft mouse model of osteosarcoma was generated to determine the antitumor effects of peiminine in vivo.

Results: Peiminine suppressed proliferation and metastasis and induced cell cycle arrest, apoptosis, and autophagy in osteosarcoma cells. These anticancer effects of peiminine were found to be dependent on intracellular ROS generation and activation of the JNK pathway. In line with these results, peiminine significantly inhibited xenograft tumor growth in vivo.

Conclusions: Peiminine induced G0/G1-phase arrest, apoptosis, and autophagy in human osteosarcoma cells via the ROS/JNK signaling pathway both in vitro and in vivo. Our study may provide an experimental basis for the evaluation of peiminine as an alternative drug for the treatment of osteosarcoma.

Resveratrol benefits the lineage commitment of bone marrow mesenchymal stem cells into osteoblasts via miR-320c by targeting Runx2

Bone marrow mesenchymal stem cells (BMSCs) are a potential source of osteoblasts and have been widely used in clinical therapies due to their pluripotency. Recent publications have found that resveratrol (RSVL) played a crucial role in the proliferation and differentiation of BMSCs; however, the underlying molecular mechanism of RSVL-induced BMSCs osteogenic differentiation needs to be fully elucidated. The objective of this study was to explore functions of miRNAs in the RSVL-treated BMSCs and its effects on the differentiation potentials of BMSCs. The findings demonstrated that RSVL enhanced the osteogenesis and suppressed the adipogenesis of BMSCs in a dose-dependent manner. Besides, a novel regulatory axis containing miR-320c, and its target Runx2 was found during the differentiation process of BMSCs under RSVL treatment. Increase of miR-320c reduced the osteogenic potential of BMSCs, while knockdown of miR-320c played a positive role in the osteogenesis of BMSCs. In contrast, overexpression of miR-320c accelerated the adipogenic differentiation, while knockdown of miR-320c restrained the adipogenic differentiation of BMSCs. The results confirmed that Runx2 might be the direct target of miR-320c in RSVL-promoted osteogenic differentiation of BMSCs. This study revealed that RSVL might be used for the treatment of bone loss related diseases and miR-320c could be regarded as a novel and potential target to regulate the biological functions of BMSCs.

MicroRNA-208a-3p promotes osteosarcoma progression via targeting PTEN

Osteosarcoma (OS) is a malignant bone tumor with a poor prognosis. Accumulated evidence has suggested that microRNAs (miRNAs/miRs) may function as either oncogenes or tumor suppressors, which are associated with tumorigenesis and the progression of different types of cancer. In the present study, the role of miR-208a-3p in OS was investigated. The expression levels of miR-208a-3p in OS tissues and cell lines were determined via reverse transcription-quantitative PCR (RT-qPCR). MTT and colony formation assays were performed to verify the proliferation rate of OS cells. In addition, the effects of miR-208a-3p on the migration and invasion of OS cells were revealed using wound-healing and Transwell assays, respectively. Furthermore, the association between miR-208a-3p and phosphatase and tensin homolog (PTEN) 3'-untranslated region was determined via luciferase reporter assays, western blot and RT-qPCR analysis. The results indicated that miR-208a-3p was upregulated in OS tissues and cell lines compared with adjacent normal tissues and human osteoblastic cells, respectively. miR-208a-3p overexpression promoted and miR-208a-3p knockdown inhibited OS cells proliferation and metastatic potential. Additionally, PTEN was validated as a direct target of miR-208a-3p and its expression was negatively associate with that of miR-208a-3p in OS cells. Taken together, these results may suggest that miR-208a-3p promoted OS cells proliferation and metastatic potential via targeting PTEN. Therefore, miR-208a-3p may be considered as a diagnostic biomarker for OS.

Antibacterial Effect of the Controlled Nanoscale Precipitates Obtained by Different Heat Treatment Schemes with a Ti-Based Nanomaterial, Ti-7.5Mo-5Cu Alloy

It is well known that copper is an excellent option for a Ti-based alloy component as a β-stabilizer that provides improved biocompatibility and antibacterial ability. The development of a Ti-based nanomaterial containing Cu is a promising strategy for addressing implant-associated infections (OII). However, the antibacterial mechanism of copper-related alloys is still unknown. There are two popular hypotheses: copper ion release sterilization and alloy contact sterilization. The main mechanism of contact sterilization may be Cu-related phase (Ti₂Cu) precipitation. Because excess copper can lead to cytotoxicity and reduce the β-Ti phase content, molybdenum needs to be added to the alloy given its well-known and widely researched β-stabilizer characteristics, which can provide satisfactory mechanical properties, wear resistance, and biocompatibility. Our study created a Ti-based nanomaterial, Ti-7.5Mo-5Cu, and performed two kinds of heat treatment schemes at different solution temperatures: 750 and 900 °C. The above schemes resulted in homogeneous and heterogeneous nucleation on the precipitation behavior of the Ti₂Cu crystal phase, which controlled its amount, distribution, and size. Finally, our results showed that Ti-7.5Mo-5Cu, especially at 900 °C, possessed excellent antibacterial ability, corrosion resistance, cytocompatibility, and induced osteogenic differentiation, indicating its potential for use as a biomedical antibacterial alloy in the future.

[Clinical study of psychological changes and post traumatic stress disorder in elderly patients with hip fracture]

Objective: To explore the psychological state and affected factors of elderly patients with hip fractures. Methods: A retrospective analysis of 156 elderly hip fracture patients(>65 years) admitted to the Department of Orthopaedics, the First Affiliated Hospital of Harbin Medical University from January 2016 to August 2019 was performed. General and psychological information were collected by questionnaire.General information included age, gender, education, whether surgery, length of stay.SCL-90, a self-assessment scale, was chosen as the psychological test to analyzed the elderly hip fracture patients' psychological status during hospitalization and the norms of SCL-90 in Chinese which were established in 1986 were used as the control group. The prognostic factors were examined by univariate and multivariate analysis. Results: Somatization, interpersonal sensitivity, depression, anxiety, paranoid factor scores, and total scores of the elderly hip fracture patients were significantly higher than control group(all P=0.00).Univariate analysis and logistic regression analysis showed that non-surgery treatment and more than 10 days of hospitalization were independent prognostic factors that affected the psychological state of elderly hip fracture patients (all P=0.00). Conclusion: Elderly patients hospitalized with osteoporosis and hip fractures are prone to have negative emotional and psychological changes.The length of hospitalization and the choice of treatment can affect patients' psychological state, suggesting that effective psychological intervention is necessary.

Mesenchymal Stem Cell Conditioned Medium Induces Differentiation of Bone Mesenchymal Stem Cells and Affects the Secretion of IL-6 and IL-1β in Inflammatory Environment

BMSCs can be an ideal tissue repair seed cell. Inflammation affects bone repair and bone damage. Our study evaluated the effects of mesenchymal stem cell conditioned medium on BMSCs differentiation and IL-6 and IL-1β secretion in inflammatory environment in vitro. Rat BMSCs were isolated and randomly divided into control group, inflammation group (treated with LPS) and induction group (mesenchymal stem cell conditioned medium in the presence of LPS) followed by analysis of BMSCs proliferation by MTT assay, Caspase 3 activity, expression of type II collagen, Runx2, OC and PPARγ 2 by real-time PCR, ALP activity, and secretion of IL-6 and IL-1β by ELISA. In inflammation group, BMSCs proliferation was significantly inhibited and Caspase 3 activity was significantly increased, along with decreased expression of type II collagen, Runx2 and OC, reduced ALP activity of ALP, increased PPARγ2 and the secretion of IL-6 and IL-1β (P < 0.05). Induction group showed significantly promoted BMSCs proliferation, decreased Caspase 3 activity, upregulated type II collagen, Runx2 and OC, elevated ALP activity, decreased PPARγ2 expression and IL-6 and IL-1β secretion compared to inflammation group (P < 0.05). Mesenchymal stem cell conditioned medium induces proliferation of BMSCs in an inflammatory environment, inhibits apoptosis and adipogenic differentiation, promotes osteogenic differentiation, and inhibits the secretion of inflammatory cytokines IL-6 and IL-1β.

[Reviewing the surgery strategy for fracture neck of femur]

Femoral neck fracture is a frequently occurring and dangerous disease of elderly patient, whose morbidity is increasing gradually with the aging of population and has become a serious social problem. Prosthetic joint replacement can relief pain and restore joint function effectively, so that more and more doctors consider it a main option for the treatment of displaced femoral neck fractures in the elderly. However, the extensive operation and high cost are burdens for patients and society. As medical technology development, the surgery strategy for fracture neck of femur should be redefined. The choice of treatment should be varied individually depend on therapeutic indication and patients' clinical condition. The treatment of aged patients with femoral neck fractures should be developed into personalized therapeutic strategies.

MicroRNA-92b-5p modulates melatonin-mediated osteogenic differentiation of bone marrow mesenchymal stem cells by targeting ICAM-1

Osteoporosis is closely associated with the dysfunction of bone metabolism, which is caused by the imbalance between new bone formation and bone resorption. Osteogenic differentiation plays a vital role in maintaining the balance of bone microenvironment. The present study investigated whether melatonin participated in the osteogenic commitment of bone marrow mesenchymal stem cells (BMSCs) and further explored its underlying mechanisms. Our data showed that melatonin exhibited the capacity of regulating osteogenic differentiation of BMSCs, which was blocked by its membrane receptor inhibitor luzindole. Further study demonstrated that the expression of miR‐92b‐5p was up‐regulated in BMSCs after administration of melatonin, and transfection of miR‐92b‐5p accelerated osteogenesis of BMSCs. In contrast, silence of miR‐92b‐5p inhibited the osteogenesis of BMSCs. The increase in osteoblast differentiation of BMSCs caused by melatonin was attenuated by miR‐92b‐5p AMO as well. Luciferase reporter assay, real‐time qPCR analysis and western blot analysis confirmed that miR‐92b‐5p was involved in osteogenesis by directly targeting intracellular adhesion molecule‐1 (ICAM‐1). Melatonin improved the expression of miR‐92b‐5p, which could regulate the differentiation of BMSCs into osteoblasts by targeting ICAM‐1. This study provided novel methods for treating osteoporosis.

A Long Noncoding RNA (lncRNA)-Associated Competing Endogenous RNA (ceRNA) Network Identifies Eight lncRNA Biomarkers in Patients with Osteoarthritis of the Knee

Background

Osteoarthritis (OA) of the knee is a common disease that is associated with chronic pain. This study aimed to identify and investigate the functional role of biomarkers associated with long noncoding RNA (lncRNA) in the progression of OA of the knee by lncRNA-associated competing endogenous RNA (ceRNA) integrated network analysis.

Material/Methods

High-quality microRNA (miRNA)-lncRNA and miRNA-mRNA interactions and lncRNA and mRNA expression profiles for patients with OA of the knee with mild and severe pain were obtained from the Gene Expression Omnibus (GEO) database (GSE99662). A three-step computational method was used to construct the lncRNA-associated ceRNA interaction network in OA by integrating miRNA-lncRNA/mRNA interactions and lncRNA/mRNA expression profiles in patients with OA with mild and severe pain.

Results

A total of 1,870 dysregulated lncRNA-mRNA interactions were obtained in the lncRNA-associated ceRNA network in OA, including 476 gain and 1,394 loss interactions, covering 131 lncRNAs and 1,251 mRNAs. Characterization of the lncRNA-associated ceRNA network in OA indicated that lncRNAs had roles in the network. Further differential expression analysis identified eight lncRNA biomarkers, which could distinguish between patients with OA with mild pain and severe pain. These lncRNA-associated interactions showed significantly different co-expression patterns in samples from patients with OA of the knee associated with mild pain.

Conclusions

Integrated network analysis of lncRNA-associated ceRNA identified eight lncRNA molecular biomarkers associated with the progression of OA of the knee.

Non‑covalent proteasome inhibitor PI‑1840 induces apoptosis and autophagy in osteosarcoma cells

Osteosarcoma (OS) is the predominant form of primary bone malignancy in children and adolescents. Although the combination of chemotherapy and modified surgical therapy leads to marked improvements in the survival rate, the therapeutic outcomes remain unsatisfactory. Therefore, the identification of novel drugs with higher efficacy and fewer side‑effects is urgently required. Proteasome inhibitors have been approved by the Food and Drug Administration (FDA) for the treatment of certain cancers, although none of them are directed against OS. Non‑covalent proteasome inhibitors, such as PI‑1840, are superior to covalent ones in numerous respects in view of their chemical structure; however, to date, no studies have been published on the effects of non‑covalent proteasome inhibitors on OS cells. In the present study, the antineoplastic effects of PI‑1840 were systematically evaluated in the OS cell lines, MG‑63 and U2‑OS. Cell viability and morphological changes were assessed by Cell Counting Kit‑8 (CCK‑8) and live/dead assays. The cell cycle was analyzed using flow cytometry (FCM) and western blot analysis (assessing the levels of the proteins p21, p27, and the tyrosine kinase, WEE1). The extent of cell apoptosis and autophagy were assessed by FCM, western blot analysis [of the apoptosis‑associated proteins, microtubule‑associated protein 1 light chain 3 α (LC3) and Beclin1], and mRFP‑GFP‑LC3 adenovirus transfection assay. Transwell and wound healing assays, and western blot analysis of the matrix metalloproteinases (MMPs)2 and 9 were performed to preliminarily evaluate the migration and invasion capability of the cells. In the present study, our results revealed that PI‑1840 inhibited the proliferation of OS cells and induced apoptosis, partly due to attenuation of the nuclear factor‑κB (NF‑κB) pathway. In addition, PI‑1840‑induced autophagy was detected, and inhibiting the autophagy of the OS cells led to an increase in the survival rate of the U2‑OS cells rather than of the MG‑63 cells. Furthermore, PI‑1840 attenuated the migration and invasion capabilities of the OS cells. In conclusion, the present study revealed PI‑1840 to be a promising drug for the treatment of OS.

miR-196 acts as a tumor suppressor in osteosarcoma by targeting HOXA9

Abnormal expression of microRNAs (miRNAs) has been found in most cancer types. Therefore, the discovery of miRNAs could help us to understand the mechanism of tumor initiation and development. The purpose of this study was to investigate the significance of miR-196 in osteosarcoma (OS) and to identify its target genes. We found miR-196 expression was significantly reduced in OS tissues and cell lines (Saos-2 and MG-63) as compared to normal tissues and cell line. The OS cell line proliferation and migration abilities were inhibited by miR-196 overexpression but promoted by miR-196 downregulation in vitro. Moreover, we revealed that miR-196 could bind to the 3'-untranslated region (3'-UTR) of homeobox A9 (HOXA9) and inhibit HOXA9 expression in OS cell lines. Furthermore, knockdown the expression of HOXA9 resulted in decreased proliferation and migration which was similar to that observed with miR-196 overexpression in OS cell lines. In summary, miR-196 inhibits proliferation and migration of OS cell lines through regulating HOXA9, which might be a useful target for OS treatment.

Construction and analysis of a ceRNA‑ceRNA network reveals two potential prognostic modules regulated by hsa‑miR‑335‑5p in osteosarcoma

Osteosarcoma is an aggressive cancer of the skeletal system, which is associated with a poor prognosis due to the high recurrence rate. Although previous studies have revealed that competitive endogenous RNAs (ceRNAs) are involved in various biological processes in the physiology and development of osteosarcoma, the roles of ceRNAs in osteosarcoma recurrence remain largely unexplored. The present study constructed a ceRNA-ceRNA network for osteosarcoma by systematically integrating matched expression profiles for microRNAs (miRNAs/miRs) and mRNAs, and identified two ceRNA-mediated modules that were associated with recurrence in patients with osteosarcoma. A multivariate Cox regression analysis demonstrated that the recurrence-free prognosis associated with the expression of the two modules was independent of other clinical factors. In addition, hsa-miR-335-3p was identified as an upstream regulating factor for both modules. In conclusion, the results of the present study suggested that ceRNAs may act as potential therapeutic biomarkers for predicting the recurrence of osteosarcoma, and may help to identify patients with osteosarcoma at a high risk of recurrence, who may benefit from adjuvant therapy.

Tetrahydrocurcumin induces mesenchymal-epithelial transition and suppresses angiogenesis by targeting HIF-1α and autophagy in human osteosarcoma

Human osteosarcoma is considered a malignant tumor with poor prognosis that readily metastasizes. Tetrahydrocurcumin (THC) has been reported to have anti-tumor activity in numerous tumors. In addition, hypoxia-inducible factor-1α (HIF-1α) has been demonstrated to be associated with tumor metastasis by regulating epithelial-mesenchymal transition (EMT). However, the role of THC in osteosarcoma remains uncertain. Therefore, this study aimed to elucidate the potential mechanisms. We found that THC significantly reduced the growth of osteosarcoma cells and suppressed migration and invasion, as tested in a nude mouse lung metastasis model. Additionally, the mesenchymal-epithelial transition (MET) process was facilitated by THC. Mechanistically, our study showed that HIF-1α had a pivotal role in the anti-metastatic effect of THC. Importantly, HIF-1α expression was downregulated by THC by inhibiting Akt/mTOR and p38 MAPK pathways. Moreover, THC exhibited a remarkable inhibitory effect on HIF-1α expression and angiogenesis under hypoxic conditions. Furthermore, THC activated autophagy and induced MET and suppressed angiogenesis in a HIF-1α-related manner. Taken together, our findings suggest that THC suppresses metastasis and invasion and this may be associated with HIF-1α and autophagy, which would potentially provide therapeutic strategies for human osteosarcoma.

Deoxyelephantopin Induces Reactive Oxygen Species-Mediated Apoptosis and Autophagy in Human Osteosarcoma Cells

BACKGROUND/AIMS

Osteosarcoma is the predominant form of primary bone malignancy. Although the combinational application of neoadjuvant chemotherapy and surgical resection significantly increases the survival rate, the therapeutic outcome remains unsatisfactory. Deoxyelephantopin (DET), an active ingredient of Elephantopus scaber, has been reported to have an anti-tumor effect in recent publications. This study aimed to investigate whether DET has antineoplastic effects on osteosarcoma cells and its underlying mechanism.

METHODS

Cell viability and morphological changes were assessed by MTT and Live/dead assays. Cell apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential were detected utilizing Annexin V-FITC/PI double staining, DCFH-DA and JC-1 probes, respectively. Autophagy was detected by mRFP-GFP-LC3 adenovirus transfection and western blot.

RESULTS

DET dose-dependently reduced the viability of osteosarcoma cells following the increase in intracellular ROS levels. Pretreatment with N-acetylcysteine (NAC) reversed this effect. Furthermore, DET induced mitochondrial apoptosis. Depolarized cells were increased, and apoptosis-related proteins, such as Bax, Bcl-2, cleaved caspase-9, cleaved caspase-3 and cleaved ploy ADP-ribose polymerase, were activated. Additionally, we found that DET could induce autophagy in osteosarcoma cells, but autophagy inhibition did not affect the decrease in cell viability.

CONCLUSION

DET induced apoptosis in osteosarcoma cells through ROS generation, mitochondrial dysfunction and caspase activation; in addition, autophagy was involved in the effects of DET on osteosarcoma cells.

Osteoclast regulation of osteoblasts via RANK‑RANKL reverse signal transduction in vitro

The treatment of osteoporosis typically inhibits the activity of osteoclasts, which subsequently results in the suppression of bone formation and maintenance, however the underlying mechanism remains to be elucidated. The receptor activator of nuclear factor κ-B ligand (RANKL)-receptor activator of nuclear factor κ-B (RANK) signaling axis is important in the osteoblast regulation of osteoclasts. RANKL surface-bound molecules expressed on T cells stimulate a reverse signaling transduction in order to regulate the T cells, therefore the present study hypothesized that RANKL expressed on osteoblasts may transfer reverse signals to regulate osteoblasts. A series of experiments were designed to test the hypothesis, using MTT, stealth RNA interference, reverse transcription-quantitative polymerase chain reaction, western blot analysis, alkaline phosphatase activity assay and alizarin red staining. The present study observed the role of RANK-RANKL reverse signaling on osteoblasts, regulated by osteoclasts. Osteoblasts were treated with recombinant RANK proteins. The soluble RANK enhanced the mineralization of osteoblasts. When the RANKL was knocked down in the osteoblast, RANK demonstrated a weak osteogenic effect on the RANKL-deficient osteoblast compared with the wild-type osteoblast which served as a control. Addition of soluble RANK activated the p38 mitogen activated protein kinase (MAPK) signaling pathway in the osteoblast and blocking this same pathway in E1 cells reduced the effect of RANK. In the co-culture system of osteoblasts and osteoclasts, p38 MAPK in E1 cells was phosphorylated a short time following co-culture and the phosphorylation then blocked by abundant soluble RANKL. The findings suggested that RANKL expressed on osteoblasts transferred reverse signals from the exterior of the cell to the interior, which regulated the osteoblasts.

A New Perspective for Osteosarcoma Therapy: Proteasome Inhibition by MLN9708/2238 Successfully Induces Apoptosis and Cell Cycle Arrest and Attenuates the Invasion Ability of Osteosarcoma Cells in Vitro

BACKGROUND

The proteasome exists in all eukaryotic cells and provides the main route of intracellular proteins degradation involved in cell growth and apoptosis. Proteasome inhibition could block protein degradation pathways and disturb regulatory networks, possibly leading to profound effects on cell growth, particularly in cancer cells. A proteasome inhibitor with an appropriate toxicity index for malignant cells rather than normal cells would be an attractive anticancer therapy.

METHODS

The human osteosarcoma (OS) cell lines MG-63 and Saos-2 and normal osteoblast cells were used to study the antitumour activity of the proteasome inhibitor MLN9708/2238.

RESULTS

MLN2238 inhibited cell growth, induced cell cycle arrest and apoptosis, and attenuated the invasion abilities of MG-63 and Saos-2 cells, with little cytotoxicity to normal cells. In addition, MLN2238 promoted antitumour mechanisms including the accumulation of E2F1, P53, P21 and other negative G2/M checkpoint proteins; up-regulated the relative expression ratio of BAX/BCL-2, APAF-1 and pro-apoptotic proteins of the BCL-2 family; triggered mitochondrial outer membrane permeabilization (MOMP); down-regulated BCL-2 and XIAP; activated caspase3/8/9; and suppressed MMP2/9 expression and secretion levels.

CONCLUSIONS

The proteasome may be a novel biochemical target for OS treatment in vitro. Our study provides a promising mechanistic framework for MLN9708/2238 in OS treatment, supporting its clinical development.

A single nucleotide polymorphism in the 3'-untranslated region of the KRAS gene disrupts the interaction with let-7a and enhances the metastatic potential of osteosarcoma cells

The objective of the present study was to explore the molecular mechanism with which a single nucleotide polymorphism (rs61764370) interferes with the interaction between the 3'-untranslated region (3'-UTR) of Kirsten rat sarcoma viral oncogene homolog (KRAS) and let-7a, and its association with the metastasis of osteosarcoma (OS). In this study, we confirmed that KRAS is a target of let-7a in OS cells, and the introduction of rs61764370 minor allele into KRAS 3'-UTR significantly compromised the microRNA (miRNA)/mRNA interaction using a luciferase reporter system. Additionally, a total of 36 OS tissue samples of three different genotypes (TT,22; TG,10; GG,4) were obtained, and the expression of let-7a and KRAS was determined. We showed that let-7a mRNA expression was similar between each group whereas the mRNA and protein expression of KRAS in the TT genotype group was significantly lower than that in the GT or GG genotype groups. Moreover, we identified a negative regulatory relationship between let-7a and KRAS. Furthermore, we demonstrated that let-7a and KRAS interfered with the viability, invasiveness and migration of OS cells genotyped as TT. In the OS cells genotyped as TG, let-7a exerted minimal effects, and the effect of KRAS siRNA remained. Taken together, the findings of the present study demonstrated that the KRAS 3'-UTR rs61764370 polymorphism interfered with miRNA/mRNA interaction, and showed that the minor allele was associated with an elevated risk of developing metastatic disease in OS.

Osthole Induces Cell Cycle Arrest and Inhibits Migration and Invasion via PTEN/Akt Pathways in Osteosarcoma

BACKGROUND/AIMS

Osteosarcoma is the second highest cause of cancer-related death in children and adolescents. Majority of osteosarcoma patients (90%) show metastasis. Previous reports revealed that osthole showed antitumor activities via induction of apoptosis and inhibition of proliferation. However, the potential effects and detailed molecular mechanisms involved remained unclear.

METHODS

Cell viability was analyzed by MTT assay in osteosarcoma cell lines MG-63 and SAOS-2. Cell cycle was detected by flow cytometry. The effects of migration and invasion were evaluated by wound healing assay and transwell assays. Moreover, the level of proteins expression was determined by Western blot.

RESULTS

The cell viability of MG63 and SAOS-2 were markedly inhibited by osthole in a dose- and time-dependent manner. Cell cycle was arrested and the ability of migration and invasion was obviously reduced when cells were exposed to osthole. Moreover, enzymes involved in PTEN/Akt pathway were regulated such as PTEN and p-Akt proteins. Furthermore, osthole inhibited the tumor growth in vivo.

CONCLUSION

Our study unraveled, for the first time, the ability of osthole to suppress osteosarcoma and elucidated the regulation of PTEN/Akt pathway as a signaling mechanism for the anti-tumor action of osthole. These findings indicate that osthole may represent a novel therapeutic strategy in the treatment of osteosarcoma.

Regulatory effect of estrogen receptor-α-mediated Wnt/β-catenin signaling pathway on osteoblast proliferation

This study was designed to investigate the regulatory effect of estrogen receptor-α (ERα)-mediated Wnt/β-catenin signaling pathway on osteoblast proliferation. Mc3T3-El cells were infected by ERα and ERβ small interfering ribose nucleic acid (siRNA) viruses and treated with estradiol 2 (E2) for 120 min after 24-h infection. Western blot was used to detect expressions of β-catenin, Gsk 3β, p-Gsk3β (Ser9) and CyclinDl; and methyl thiazolyl tetrazolium (MTT) was applied to detect osteoblast proliferation after interference by different ERs. Western blot results indicated that the expressions of β-catenin, p-Gsk3β (Ser9) and CyclinDl decreased after ERβ interference and ERα + ERβ joint interference, and a more obvious decrease was found after the joint interference. After ERβ interference, β-catenin, p-Gsk3β (Ser9) and CyclinDl were strongly expressed compared with expressions in the blank control group. MTT results demonstrated that the proliferation rate of osteoblast was lower after the joint interference than after ERβ interference, while a slight increase was found in the proliferation rate after ERβ interference in comparison with the blank control group. It can be concluded that estradiol is able to promote the proliferation of osteoblasts in mice by ERα-mediated Wnt/β-catenin signaling pathway.

Transplantation of iliac bone flaps pedicled with sartorius muscular fascia around superficial circumflex iliac vessels in the treatment of osteonecrosis of the femoral head

The aim of this study was to evaluate the efficacy and clinical application of iliac bone flaps pedicled with sartorius muscular fascia around superficial circumflex iliac vessels for the treatment of Association for Research on Osseous Circulation (ARCO) stage II-III osteonecrosis of the femoral head (ONFH) in young adults. In total, 35 patients with ONFH at ARCO stage II-III were treated with iliac bone flaps pedicled with sartorius muscular fascia around superficial circumflex iliac vessels. Patients were classified according to etiological factors and ARCO stages. Postoperative clinical assessment was accomplished with Harris hip scores (HHSs), and ARCO stage change was evaluated with imaging. All 35 patients completed the follow-up. The HHS results indicated that hip function was improved significantly from the preoperative status of 56.53±7.66 points to the postoperative status of 87.49±5.89 points (P<0.0001). Postoperative imaging displayed apparent osteogenesis and satisfactory structural remodeling in 32 patients, presenting no staging progress. Three patients exhibited mild collapse (<2 mm) compared with preoperative collapse. No patients developed osteoarthritis or required total hip arthroplasty. The clinical success rate was 91.43%. Iliac bone flaps pedicled with sartorius muscular fascia around superficial circumflex iliac vessels is a feasible means for treating ARCO stage II-III ONFH in young adults, who have abundant blood circulation, good osteogenesis and function of the hip. It is also an effective means for retaining the femoral head.

Long noncoding RNA FGFR3-AS1 promotes osteosarcoma growth through regulating its natural antisense transcript FGFR3

Long noncoding RNAs (lncRNAs), a new class of RNAs with no protein-coding potential, have been reported to have crucial roles in the regulation of a variety of tumors. However, the functions and molecular mechanisms of lncRNAs to osteosarcoma are still largely unknown. The purpose of this study is to examine the expression, functions and molecular mechanisms of a new lncRNA FGFR3 antisense transcript 1 (FGFR3-AS1) in osteosarcoma. The expression of FGFR3-AS1 was examined by real-time quantitative PCR. The regulation of FGFR3 by FGFR3-AS1 was examined by RNase protection assay, real-time quantitative PCR, western blotting, and luciferase reporter assay. The effects of FGFR3-AS1 on osteosarcoma cell proliferation and cell cycle were determined by Cell Counting Kit-8, Ethynyl deoxyuridine incorporation assay and flow cytometry. FGFR3-AS1 was upregulated in osteosarcoma. Increased FGFR3-AS1 expression correlates with large tumor size, advanced Enneking stage, metastasis and poor survival. Through antisense pairing with FGFR3 3'UTR, FGFR3-AS1 increases FGFR3 mRNA stability and upregulates FGFR3 expression. The expression of FGFR3-AS1 and FGFR3 is positively correlated in osteosarcoma tissues. Knockdown of FGFR3-AS1 inhibits the proliferation and cell cycle progression of osteosarcoma cells in vitro. Moreover, knockdown of FGFR3-AS1 inhibits xenograft tumor growth of osteosarcoma cells in vivo. These data demonstrate the mechanisms of how antisense noncoding RNA regulate the expression of sense genes, and show the pivotal functions of FGFR3-AS1 in osteosarcoma.

The effects of 6-gingerol on proliferation, differentiation, and maturation of osteoblast-like MG-63 cells

We investigated whether 6-gingerol affects the maturation and proliferation of osteoblast-like MG63 cells in vitro. Osteoblast-like MG63 cells were treated with 6-gingerol under control conditions, and experimental inflammation was induced by tumor necrosis factor-α (TNF-α). Expression of different osteogenic markers and cytokines was analyzed by real-time PCR, Western blotting, and enzyme-linked immunosorbent assay. In addition, alkaline phosphatase (ALP) enzyme activity and biomineralization as markers for differentiation were measured. Treatment with 6-gingerol resulted in insignificant effects on the proliferation rate. 6-Gingerol induced the differentiation of osteoblast-like cells with increased transcription levels of osteogenic markers, upregulated ALP enzyme activity, and enhanced mineralized nodule formation. Stimulation with TNF-α led to enhanced interleukin-6 and nuclear factor-κB expression and downregulated markers of osteoblastic differentiation. 6-Gingerol reduced the degree of inflammation in TNF-α-treated MG-63 cells. In conclusion, 6-gingerol stimulated osteoblast differentiation in normal physiological and inflammatory settings, and therefore, 6-gingerol represents a promising agent for treating osteoporosis or bone inflammation.

THE EFFECT OF DIHYDROARTEMISININ ON THE PROLIFERATION, METASTASIS AND APOPTOSIS OF HUMAN OSTEOSARCOMA CELLS AND ITS MECHANISM

This study aims to research the effect of dihydroartemisinin on the proliferation, metastasis and apoptosis in human osteosarcoma cells 143B and the underlying mechanism. This study designed five groups for experiment and control, using dimethylsulfoxide (DMSO), and docosahexaenoic acid (DHA) at concentrations of 15, 25, 35 μmol.L-1 respectively. Experiments including methyl thiazolyl tetrazolium (MTT) assay, clone formation assay, Hoechst 33258 staining assay, luciferase reporter plasmid assay, Western blot and scratch test were carried out. In addition, SPSS 18.0 software from IBM was used for statistical analysis and all the data obtained from the experiments were expressed as mean ± SD, and variance was used to compare the difference between the groups. DHA is proved to be able to inhibit the proliferation and metastasis of osteosarcoma cells, as well as leaving a positive effect on apoptosis in the cytomorphosis. It achieves regulation over the human osteosarcoma cells by keeping the expression of related protein under control.

Axonal regeneration in early stages of sciatic nerve crush injury is enhanced by α7nAChR in rats

This study investigated the role of alpha 7 nicotinic acetylcholine receptor (α7nAChR) in axonal regeneration after crush injury to the rat sciatic nerve. The time course of α7nAChR expression following injury was assessed by immunohistochemistry and western blotting, and local inflammation, as indicated by the expression of tumor necrosis factor (TNF)-α, was detected by enzyme-linked immunosorbent assay. Axonal regeneration was evaluated by the pinch-test, morphometric analysis, and by measuring growth-associated protein 43 expressions. Local α7nAChR expression increased on day 1, peaked on day 3, and remained elevated on day 5 following nerve injuries. Prominent α7nAChR immunoreactivity was observed in Schwann cells, endothelial cells of the capillaries, and a small number of inflammatory cells. Application of the selective α7nAChR agonist PNU-282987 decreased TNF-α level and enhanced axonal regeneration, but this effect was blocked by concomitant treatment with methyllycaconitine, a α7nAChR antagonist. The results indicate that the local expression of α7nAChR is increased during the early stages of sciatic nerve injury, and application of a α7nAChR agonist promotes axonal regeneration by suppression of TNF-α-mediated inflammation. The α7nAChR can act as a neuroprotective agent and α7nAChR activation may be a useful therapeutic strategy to treat peripheral nerve injury.

MicroRNA-214 regulates osteosarcoma survival and growth by directly targeting phosphatase and tensin homolog

An increasing number of microRNAs (miRNAs) have been identified as diagnostic and prognostic biomarkers, as well as additional therapeutic tools, in skeletal diseases. Recent studies have established the pathophysiological role of miR‑214, using human osteoporotic bone specimens. However, miR‑214 expression levels and the underlying regulatory mechanism in human osteosarcoma remain unclear. Quantitative polymerase chain reaction (qPCR) was used to examine the expression of miR‑214 in human osteosarcoma tissues and cells. Transfection of the cells with either a miR‑214 expressing‑plasmid, mimic or inhibitor was performed, in order to investigate the role of miR‑214 in osteosarcoma. In this study, miR‑214 was shown to be significantly increased in the majority of 15 examined osteosarcoma tissues and in the Saos‑2 human osteosarcoma cell line. Overexpression of miR‑214 in Saos‑2 cells induced cell proliferation, while inhibition of miR‑214 promoted Saos‑2 cell apoptosis in vitro. Furthermore, ectopic expression of miR‑214 markedly promoted osteosarcoma development in a subcutaneous xenotransplantation model in BALB/c athymic nude mice. The role of miR‑214 in osteocarcinogenesis was further investigated and phosphatase and tensin homolog (PTEN) was determined to be a direct target of miR‑214 in Saos‑2 cells. The proliferation‑promoting effect of PTEN knockdown was similar to that of miR‑214 overexpression. This study revealed that miR‑214 exerted a crucial role in promoting osteosarcoma progression and this suggests that modulation of miR‑214 levels may provide a novel therapeutic approach in cancer treatment.

A selenosemicarbazone complex with copper efficiently down-regulates the 90-kDa heat shock protein HSP90AA1 and its client proteins in cancer cells

Background

The 90-kDa heat shock protein HSP90AA1 is critical for the stability of several proteins that are important for tumor progression and thus, is a promising target for cancer therapy. Selenosemicarbazone metal complexes have been shown to possess anticancer activity through an unknown molecular mechanism.

Methods

The MTT assay, fluorescence-activated cell sorting, and fluorescent microscopy were used to analyze the mechanism of the anti-cancer activity of the selenosemicarbazone metal complexes. Additionally, RNA-seq was applied to identify transcriptional gene changes, and in turn, the signaling pathways involved in the process of 2-24a/Cu-induced cell death. Last, the expression of HSP90AA1, HSPA1A, PIM1, and AKT proteins in 2-24a/Cu-treated cells were investigated by western blot analysis.

Results

A novel selenosemicarbazone copper complex (2-24a/Cu) efficiently induced G2/M arrest and was cytotoxic in cancer cells. 2-24a/Cu significantly induced oxidative stress in cancer cells. Interestingly, although RNA-seq revealed that the transcription of HSP90AA1 was increased in 2-24a/Cu-treated cells, western blotting showed that the expression of HSP90AA1 protein was significantly decreased in these cells. Furthermore, down-regulation of HSP90AA1 led to the degradation of its client proteins (PIM1 and AKT1), which are also cancer therapy targets.

Conclusion

Our results showed that 2-24a/Cu efficiently generates oxidative stress and down-regulates HSP90AA1 and its client proteins (PIM1, AKT1) in U2os and HeLa cells. These results demonstrate the potential application of this novel copper complex in cancer therapy.

Acriflavine suppresses the growth of human osteosarcoma cells through apoptosis and autophagy

The aim of this study was to investigate the effects of acriflavine on viability and induction of apoptosis and autophagy in human osteosarcoma cell lines MG63. Inhibition of cell proliferation by acriflavine was determined using MTT assay. Induction of apoptosis was examined by measuring the changes in expression of Bcl-2 and Bax in messenger RNA (mRNA) and protein levels. Identification of the proteolytic cleavage of poly (ADP)-ribose polymerase (PARP) and caspase-3 and caspase-9 was carried out to study apoptotic cell death. Autophagic effects were examined by quantitation of mRNA expression of autophagy protein 5 (Atg5) and Beclin1 and identifying accumulation of microtubule-associated protein 1 light chain 3 (LC3)-II. The results showed acriflavine inhibited cell proliferation of osteosarcoma cells in dose-dependent fashion. Acriflavine-induced cell death was attributed to both apoptosis and autophagy. Moreover, it was associated with changes in the levels of Bcl-2 and Bax in the osteosarcoma cells. The antiseptic agent, acriflavine, has anticancer potential through synergistic activity of apoptosis and autophagy.

Bufalin inhibited the growth of human osteosarcoma MG-63 cells via down-regulation of Bcl-2/Bax and triggering of the mitochondrial pathway

Cinobufacini (Huachansu), a Chinese medicine prepared from the skin of Bufo bufo gargarizans Cantor (Bufonidae), has potent anti-tumor activity in vitro and in vivo. However, the molecular mechanism of cell apoptosis induced by Bufalin remains elusive. Here, we investigated the apoptosis in Bufalin-treated human osteosarcoma MG-63 cells. The results showed that Bufalin could inhibit cell proliferation and induce apoptosis in a dose- and time-dependent manner. Further investigation revealed that a disruption of mitochondrial transmembrane potential (MMP) and an up-regulation of reactive oxygen species (ROS) in Bufalin-treated cells. By western blot analysis, we found that the up-regulation of Apaf-1, cleaved PARP, cleaved caspase-3, cleaved caspase-9, and Bax/Bcl-2, varies with different concentration of Bufalin. These protein interactions may play a pivotal role in the regulation of apoptosis. Taken together, these results overall indicate that Bufalin could be used as an effective anti-tumor agent in therapy of osteosarcoma targets the mitochondrial-dependent signaling pathway.

Histone deacetylase inhibitor sodium butyrate promotes the osteogenic differentiation of rat adipose-derived stem cells

Adult stem cells hold great promise for use in tissue repair and regeneration. Recently, adipose tissue-derived stem cells (ADSCs) were found to be an appealing alternative to bone marrow stem cells (BMSCs) for bone tissue engineering. The main benefit of ADSCs is that they can be easily and abundantly available from adipose tissue. However, our prior study discovered an important phenomenon that BMSCs have greater osteogenic potential than ADSCs in vitro and epigenetic regulation plays a critical role in runt-related transcription factor 2 (Runx2) expression and thus osteogenesis. In this study, we aimed to improve the osteogenic potential of ADSCs by histone deacetylase inhibitor sodium butyrate (NaBu). We found that NaBu promoted rat ADSC osteogenic differentiation by altering the epigenetic modifications on the Runx2 promoter.

miR-126 functions as a tumor suppressor in osteosarcoma by targeting Sox2

Osteosarcoma (OS) is the most common malignant bone tumor in children and young adults, the early symptoms and signs of which are non-specific. The discovery of microRNAs (miRNAs) provides a new avenue for the early diagnosis and treatment of OS. miR-126 has been reported to be highly expressed in vascularized tissues, and is recently widely studied in cancers. Herein, we explored the expression and significance of miR-126 in OS. Using TaqMan RT-PCR analysis, we analyzed the expression of miR-126 in 32 paired OS tumor tissues and 4 OS cell lines and found that miR-126 was consistently under-expressed in OS tissues and cell lines compared with normal bone tissues and normal osteoblast cells (NHOst), respectively. As miR-126 is significantly decreased in OS tissues and cell lines, we sought to compensate for its loss through exogenous transfection into MG-63 cells with a miR-126 mimic. Ectopic expression of miR-126 inhibited cell proliferation, migration and invasion, and induced apoptosis of MG-63 cells. Moreover, bioinformatic prediction suggested that the sex-determining region Y-box 2 (Sox2) is a target gene of miR-126. Using mRNA and protein expression analysis, luciferase assays and rescue assays, we demonstrate that restored expression of Sox2 dampened miR-126-mediated suppression of tumor progression, which suggests the important role of miR-126/Sox2 interaction in tumor progression. Taken together, our data indicate that miR-126 functions as a tumor suppressor in OS, which exerts its activity by suppressing the expression of Sox2.

A minimally invasive modified reverse sural adipofascial flap for treating posttraumatic distal tibial and calcaneal osteomyelitis

Our aim was to report a modified reverse sural adipofascial flap for treating posttraumatic distal tibial or calcaneal osteomyelitis. We retrospectively reviewed the records of 15 patients with posttraumatic distal tibial or calcaneal osteomyelitis treated with modified reverse sural adipofascial flaps between 2005 and 2010. The flap was raised through 2 short incisions in the posterior aspect of the lower leg. The raw surface of the flap was covered with a full-thickness skin graft. Donor sites were closed primarily. Lower Extremity Functional Scale (LEFS) scores and 2-point discrimination (TPD) were recorded preoperatively and postoperatively. There were 12 males and 3 females, with an average age of 39 years (range = 18-55 years). Twelve lesions were in the distal tibia and 3 in the calcaneus. The flap ranged in size from 11 × 5 cm to 16 × 7 cm. All flaps survived, and skin grafts healed without complications. Recipient sites had an anatomic contour, and all patients were able to ambulate without the assistance of special shoes or orthoses. No infections recurred, and no ulcers of the grafted skin occurred with the regular wearing of shoes. The follow-up duration was 18.7 ± 6.8 months (range = 12-36 months). The mean LEFS score increased from 22.4 ± 8.3 preoperatively to 53.0 ± 11.2 postoperatively (P = .001). TPD markedly recovered at 24 months postoperatively. The modified reverse sural adipofascial flap provides good outcomes in treating distal tibial and calcaneal osteomyelitis with minimal donor site morbidity.

Construction of adipose scaffold for bone repair with gene engineering bone cells

The bone defect repairing is still a challenge in orthopedics. As the gene engineering bones have been used in the bone repairing clinic, the scaffold construction is a critical fact to be considered. This study aims to construct optimal scaffolds using adipose tissue in the bone repair together with the gene engineering osteocytes. Rat adipose stem cells (ASC) were prepared; the cells were transduced with the OCT-4 gene carrying lentiviral vectors (OCT-4-Lv). Artificial bone defects were created in the rat femoral bone. The bone defects were filled up with adipose scaffolds and shaped by using surrounding muscles and supported with orthopedic splints. ASCs with or without transducing the OCT-4-Lv were injected into the adipose scaffolds. The rats were sacrificed 12 weeks after the surgery. After receiving the OCT-4-Lv, the expressions of OCT-4, RUNX2 and osteocalcin were detected in the ASCs. X-ray examination showed that rats received the OCT-4-Lv transduced ASCs together with the adipose pad had new bone formation in the defect area; none of the control rats showed any new bone formation in situ. The results were supported by histological assessment. Using adipose scaffold and OCT-4-modified ASC transplantation can repair bone defects.

Effect of growth factors (BMP-4/7 & bFGF) on proliferation & osteogenic differentiation of bone marrow stromal cells

BACKGROUND & OBJECTIVES

BMP (bone morphogenetic protein)-4/7 and bFGF (basic fibroblast growth factor) significantly promote the osteogenic activity and the proliferation of rabbit BMSCs (bone marrow stromal cells), respectively. However, their synergistic effects on the proliferation and the differentiation of BMSCs remain unclear. In the present study, the effects of bFGF and BMP-4/7 were investigated on the proliferation and the differentiation of rat BMSCs in vitro.

METHODS

BMSCs were isolated from New Zealand white rabbits and cultured to the third passage. The samples were divided into five groups according to the material implanted: (A) 80 ng/ml BMP-4/7; (B) 80 ng/ml bFGF; (C) 30 ng/ml BMP-4/7 and 30 ng/ml bFGF; (D) 50 ng/ml BMP-4/7 and 50 ng/ml bFGF; and (E) 80 ng/ml BMP-4/7 and 80 ng/ml bFGF. Cell proliferation was analyzed using methyl thiazolyl tetrazolium (MTT) assay. Alkaline phosphatase activity and osteocalcin (OC) dynamics were also measured.

RESULTS

BMP-4/7 alone significantly (P<0.05) promoted the proliferation of BMSCs. At the same time, it also promoted or inhibited the osteogenic differentiation of BMSCs. The synergistic effects of BMP-4/7 and bFGF significantly promoted both the proliferation and the osteogenic differentiation of BMSCs. The treatment of the synergistic effects was dose and time dependent.

INTERPRETATION & CONCLUSIONS

A rational combination of BMP-4/7 and bFGF can promote the proliferation and the osteogenic differentiation of BMSCs. In addition, the synergistic functions are effective.

Vitamin D metabolism in human bone marrow stromal (mesenchymal stem) cells

There are many human extra-renal tissues and cells that biosynthesize 1α,25-dihydroxyvitamin D (1α,25(OH)(2)D) by the action of CYP27B1/1α-hydroxylase. Human marrow stromal cells (hMSCs), also known as mesenchymal stem cells, were isolated from marrow discarded from well-characterized, consented subjects during common orthopedic procedures. Human MSCs can give rise to osteoblasts, chondrocytes, adipocytes, and other lineages. Their in vitro differentiation to osteoblasts is stimulated by 1α,25(OH)(2)D, and recent evidence indicates that they have the capacity to metabolize vitamin D in a regulated manner. Human MSCs express the vitamin D receptor, 25-hydroxylases, 1α-hydroxylase, and 24-hydroxylase; stimulation of in vitro osteoblastogenesis by 25(OH)D depends on the activity of CYP27B1/1α-hydroxylase. The finding that hMSCs are a both a producer and target of 1α,25(OH)(2)D suggests a potential autocrine/paracrine role of vitamin D metabolism in osteoblast differentiation. Expression and enzyme activity of CYP27B1/1α-hydroxylase are upregulated by substrate 25(OH)D and Parathyroid Hormone (PTH) and are downregulated by 1α,25(OH)(2)D. With subject age, there are decreases in basal osteoblast potential and in stimulation of osteoblastogenesis by 1α,25(OH)(2)D, 25(OH)D, and PTH. In vitro treatment with a combination of 25(OH)D and PTH rejuvenated osteoblastogenesis with hMSCs from elders; this was attributable to increases in CYP27B1/1α-hydroxylase and in receptor for each hormone by the reciprocal factor. Other clinical variables beside age, i.e. low serum 25(OH)D or low estimated glomerular filtration rate, are correlated with reduced osteoblastogenesis. These studies suggest that osteoblastogenesis may not be optimal unless there is sufficient serum 25(OH)D substrate for hMSCs to synthesize and respond to local 1α,25(OH)(2)D.

Result of a randomized clinical trial comparing different types of anesthesia on the immune function of patients with osteosarcoma undergoing radical resection

AIM

The purpose of this article was to explore the effects of different anesthesia drugs and techniques on the immune function of patients with osteosarcoma around the knee undergoing radical resection.

METHODS

Forty-five ASA (American Society of Anesthesiologists) I-II patients were randomized and divided into three groups: the epidural anesthesia group (Group A), the general anesthesia group (Group B), and the combination of epidural anesthesia and general anesthesia group (Group C). The populations of T lymphocyte subsets (CD3+, CD4+, CD8+, CD4+/CD8+) and a possible association between these variables were investigated 2 h before anesthesia, before and after skin incision, and on the 1st, 3rd and 5th days after operation.

RESULTS

The serum sIL-2 levels and T lymphocyte subset populations did not show significant differences among the three groups before anesthesia and skin incision. Serum sIL-2R increased 2 h after skin incision and on the 1st and 3rd day after operation in groups A and B (P < 0.01), and was higher than that of group C 2 h after skin incision and on the 1st day after operation (P < 0.01). Serum sIL-2R increased on the 1st postoperative day in group C. The CD3+, CD4+ and CD4+/CD8+ populations decreased significantly in all groups 2 h after skin incision, and on the 1st and 3rd days after operation (P < 0.05). However, in group C, CD4+/CD8+ levels had almost returned to baseline values on the 3rd day after operation (P > 0.05), and were significantly higher than those of groups A and B (P < 0.05). On the 5th day after operation, CD3+, CD4+ and CD4+/CD8+ levels had returned to baseline values before anesthesia in group C (P > 0.05), and were significantly higher than those of groups A and B (P < 0.05).

CONCLUSION

Epidural anesthesia combined with general anesthesia might reduce the stress reaction and the effect of anesthetic drugs on sIL-2 levels and T lymphocyte subsets, contributing to the restoration of immune function in cancer patients.

Modified distally based sural adipofascial flap for reconstructing of leg and ankle

BACKGROUND

While free flaps can be used in many cases to cover soft tissue defects in the distal leg and ankle in a single stage, factors such as diabetes and advanced age can interfere with success of vascular anastomoses.

METHODS

Twenty-five patients with deep tissue exposure of the distal leg and ankle underwent reconstruction with a modified reverse sural adipofascial flap. Seventeen cases were due to trauma (13 due to high velocity trauma). All 17 had anterior tibial soft tissue defects without significant rear calf soft tissue injury. Eight patients had iatrogenic soft tissue defects due to orthopaedic surgeries for fractures. The flap is raised through two small incisions (3-5 cm) in the posterior aspect of the leg and the subcutaneous fat is split such that some is preserved with the skin. Once the flap is in place, it is covered by a full-thickness skin graft and the donor site is closed primarily.

RESULTS

Twenty-one flaps survived. Four had partial loss of the skin graft on the flap, which healed spontaneously without secondary resurfacing. Anatomic contour was obtained in the recipient sites of all 25 patients. All donor sites healed primarily with the preservation of protective sensation in the calf and acceptable aesthetic appearance. Numbness in the lateral dorsal foot improved gradually and only minor residual numbness was noted at 1 year postoperatively.

CONCLUSIONS

The modified reverse sural adipofascial flap preserved the sensation of the donor site and the anatomic contour of both recipient and donor sites.

Distribution of regulatory T cells and interaction with dendritic cells in the synovium of rheumatoid arthritis

OBJECTIVES

The aim of this study was to investigate the tissue distribution of regulatory T cells (Treg cells) and their interaction with dendritic cells (DCs) in synovium from patients with rheumatoid arthritis (RA) or osteoarthritis (OA).

METHODS

Immunohistochemical staining was used to investigate the distribution of Treg cells and the interaction between Treg cells and DCs in RA (n = 30) and OA synovium (n = 8). mRNA levels were measured by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Large numbers of Treg cells were observed in lymphoid aggregates and perivenular infiltration areas in the RA synovium. Specific cellular markers for Treg cells (Foxp3, CD39, LAG-3, and Nrp-1) were found in lymphoid aggregates, perivenular infiltration, and scattered in lining layer areas. As molecular markers for DCs, DC-LAMP, DEC-205, CD80/86, and CD83 were also detected in the lymphoid aggregates and perivenular infiltration areas in RA. Furthermore, the co-localization of Treg cells and DCs was confined mainly in the lymphoid aggregation areas. The number of DCs increased significantly more than the number of Treg cells with inflammatory progression in RA. mRNA expression of the cellular markers for Treg cells (Foxp3, LAG-3, and Nrp-1) and the molecular markers for DCs (DC-LAMP and DEC-205) was increased in RA compared with OA synovium.

CONCLUSIONS

Our results indicate that DCs play a dominant role in regulating the activation and progression of immune responses in RA, even though the number of Treg cells was upregulated at the same time. This suggests that Treg cells do not function normally to suppress the maturation of DCs in the RA synovium.

Inactivation of the Rho-ROCK signaling pathway to promote neurologic recovery after spinal cord injuries in rats

BACKGROUND

After injury, axonal regeneration of the adult central nervous system (CNS) is inhibited by myelin-derived growth-suppressing proteins. These axonal growth inhibitory proteins are mediated via activation of Rho, a small GTP-binding protein. The activated form of Rho, which is bound to GTP, is the direct activator of Rho kinase (ROCK) through serial downstream effector proteins to inhibit axonal regeneration. The objective of this study was to observe the therapeutic effect of inactivation of the Rho-ROCK signaling pathway to promote neurologic recovery after spinal cord injuries in rats.

METHODS

One hundred and twenty adult female Sprague-Dawley rats were randomly divided into three groups. Laminectomies alone were conducted in 40 rats in the sham group. Laminectomies and spinal cord transections were performed in 40 rats in the control group (treated with normal saline administered intraperitoneally). Laminectomies and spinal cord transections were performed in 40 rats in the fasudil-treated group (treated with fasudil administered intraperitoneally). Neurologic recovery was evaluated before surgery and 3 days, and 1, 2, 3, and 4 weeks after surgery using the Basso-Beattie-Bresnahan (BBB) scale of hind limb movement. At the same time, the expression of RhoA mRNA was determined with RT-PCR. Histopathologic examinations and immunofluorescence staining of NF were performed 1 month after surgery.

RESULTS

Compared with the control group, the BBB scores of the fasudil-treated group were significantly increased and the expression of RhoA mRNA was significantly decreased. In the fasudil-treated group, a large number of NF-positive regenerating fibers was observed; some fibers crossed the slit of the lesion.

CONCLUSION

Inactivation of the Rho-ROCK signaling pathway promotes CNS axonal regeneration and neurologic recovery after spinal cord injuries in rats.

Effect of recombinant adeno-associated BMP-4/7 fusion gene on the biology of BMSCs

The aim of the study was to investigate the effect of recombinant adeno-associated virus (AAV) with morphogenetic protein 4/7 fusion gene on the ossification of rabbit bone marrow stromal cells (BMSCs). The genes BMP-4 and BMP-7 were obtained through one-step reverse transcriptase polymerase chain reaction from human placental cells. The BMP-4/7 fusion gene was generated through recombination. The rabbit BMSCs were transfected with the recombinant AAV vectors carrying AAV-BMP-4/7 with various multiplicity of infection (MOI) values. Expression of fusion gene BMP-4/7 protein was determined by the ELISA method. The ossification of cells was evaluated by observing alkaline phosphatase (ALP) and osteocalcin (OC) activity after transfection for 7 and 14 days. We successfully constructed the recombinant AAV with the BMP-4/7 fusion gene. A 29-20 kDa protein was shown by SDS-PAGE electrophoresis following transfection with AAV-BMP-4/7. The fusion protein BMP-4/7 in BMSCs transferred by AAV showed a positive correlation with various MOI values. There was significantly higher ALP and OC activity in the AAV-BMP-4/7 transfection groups than in the AAV-EGFP groups (t(ALP)=896.88, P<0.001, t(OC)=543.24, P<0.01). The fusion gene BMP-4/7 is capable of enhancing the expression of BMPs and possesses significant ossification activity through AAV.

Dendritic cells of synovium in experimental model of osteoarthritis of rabbits

AIMS

Dendritic cells (DCs) are critical initiators of immune responses, however, its distribution and role in osteoarthritis (OA) remains largely unknown. This study is to investigate the distribution of DCs in the rabbits' synovium of experimental OA.

METHODS

Model of OA was established by excising the medial meniscus of both hind knees in New Zealand white rabbits. The grades of synovium and articular cartilage were assessed and scored by hematoxylin eosin stain after 2, 4, 8, and 12 weeks of operation. The distribution of DCs was investigated by immunohistochemistry staining in the synovium from OA rabbits. The levels of IL-1β and TNF-α in synovial fluid were measured by ELISA kits.

RESULTS

Molecular markers for DCs, such as DC-LAMP, CD80, CD83, and CD86 were detected in lymphoid aggregations and perivenular infiltration areas in the synovium from OA rabbits. Large numbers of DCs were observed in the synovium in the early stages (2 or 4 weeks) after operation. The number of DCs was significantly increased with the progression of inflammatory grade in synovium in the same early stages. Expression of IL-1β and TNF-α were also increased in the early stages, then decreased with the inflammatory regression in synovium.

CONCLUSION

The data from this study strongly suggested that DCs may play a key role, at least in part, in inflammation of the OA pathogenesis, especially in the early stages of OA.