A Dilated Residual Network for Turbine Blade ICT Image Artifact Removal.

Artifacts are divergent strip artifacts or dark stripe artifacts in Industrial Computed Tomography (ICT) images due to large differences in density among the components of scanned objects, which can significantly distort the actual structure of scanned objects in ICT images. The presence of artifacts can seriously affect the practical application effectiveness of ICT in defect detection and dimensional measurement. In this paper, a series of convolution neural network models are designed and implemented based on preparing the ICT image artifact removal datasets. Our findings indicate that the RF (receptive field) and the spatial resolution of network can significantly impact the effectiveness of artifact removal. Therefore, we propose a dilated residual network for turbine blade ICT image artifact removal (DRAR), which enhances the RF of the network while maintaining spatial resolution with only a slight increase in computational load. Extensive experiments demonstrate that the DRAR achieves exceptional performance in artifact removal.

RDASNet: Image Denoising via a Residual Dense Attention Similarity Network.

In recent years, thanks to the performance advantages of convolutional neural networks (CNNs), CNNs have been widely used in image denoising. However, most of the CNN-based image-denoising models cannot make full use of the redundancy of image data, which limits the expressiveness of the model. We propose a new image-denoising model that aims to extract the local features of the image through CNN and focus on the global information of the image through the attention similarity module (ASM), especially the global similarity details of the image. Furthermore, dilation convolution is used to enlarge the receptive field to better focus on the global features. Moreover, avg-pooling is used to smooth and suppress noise in the ASM to further improve model performance. In addition, through global residual learning, the effect is enhanced from shallow to deep layers. A large number of experiments show that our proposed model has a better image-denoising effect, including quantitative and visual results. It is more suitable for complex blind noise and real images.

ATBF1 is a potential diagnostic marker of histological grade and functions via WNT5A in breast cancer.

BACKGROUND: Histological grade has been demonstrated to be an important factor of breast cancer outcome and is associated with cell differentiation and is currently being evaluated via H&E-stained sections. Molecular biomarkers are essential to improve the accuracy of histological grading. ATBF1, a large transcription factor, has been considered a tumor suppressor gene with frequent mutations or deletions in multiple cancers. In breast cancer, ATBF1 was reported to function in cell differentiation and mammary development. However, its role in the clinic has rarely been reported. METHODS: Breast cancer tissues (BCTs) and adjacent noncancerous tissues (ANCTs) were collected to analyze the expression of ATBF1 at the mRNA and protein levels. Three anti-ATBF1 antibodies recognizing independent peptides of ATBF1 (N-terminal end, middle region and C-terminal end) were applied for IHC staining. Small interfering RNA (siRNA) was used to silence ATBF1 expression and to investigate the roles of ATBF1 in MCF7 cells. Microarrays were introduced to analyze the differentially expressed genes, enriched GO terms and KEGG terms regulated by ATBF1 and its potential downstream genes, which were further confirmed in vitro and in clinical samples. RESULTS: The expression of ATBF1 was reduced in BCTs at both the mRNA and protein levels compared with that in ANCTs. ATBF1 protein was predominantly localized in the nucleus of ANCTs but in the cytoplasm of BCTs. Both the mRNA and protein levels of ATBF1 were significantly correlated with histological grade. Consistently, knockdown of ATBF1 increased stemness marker expression and reduced differentiation markers in vitro. Further analysis identified WNT5A as an essential downstream gene of ATBF1 in breast cancer cells. Treatment of WNT5A disrupted cell proliferation induced by ATBF1 silencing. In BCTs, a significant correlation was observed between the expression of WNT5A and ATBF1. CONCLUSION: The results indicated that ATBF1 expression might be a useful diagnostic marker associated with histological grade and breast cancer malignancy. WNT5A and its signaling pathway are novel mechanisms by which ATBF1 contributes to breast cancer tumorigenesis.

[Research progress of decellularized extracellular matrix hydrogel in regenerative medicine].

Decellularized extracellular matrix (dECM) has been widely used as a scaffold for regenerative medicine due to its high biomimetic and excellent biocompatibility. As a functional polymer material with high water content and controlled fluidity, hydrogel is very promising for some minimally invasive surgery in clinical practice. In recent years, with the rapid development of hydrogel theory and technology, dECM hydrogel has gradually become a research hotspot in the field of regenerative medicine. In this paper, the related researches in recent years are reviewed regarding the preparation of dECM hydrogel and its preclinical application. The future clinical use is also prospected.

Isoquercitrin promotes the osteogenic differentiation of osteoblasts and BMSCs via the RUNX2 or BMP pathway.

AIM: Isoquercitrin is widely present in fruits, vegetables and medicinal herbs. As a natural phytoestrogen, isoquercitrin has been considered a possible osteoporosis prevention option to avoid the risk of hormone therapy. MATERIALS AND METHODS: The cell proliferation of osteoblasts and bone mesenchymal stem cells (BMSCs) was examined by cell counting kit-8 (CCK-8). The osteogenic differentiation was evaluated by real-time qPCR, ALP staining and Alizarin Red S staining. Small interfering RNA (siRNA) was used to knockdown the expression of runt-related transcription factor 2 (RUNX2). RESULTS: The cell proliferation of osteoblasts and BMSCs was promoted by isoquercitrin at low concentrations. High concentrations of isoquercitrin promoted the osteogenic differentiation via RUNX2 expression in osteoblasts and via the bone morphogenetic protein (BMP) pathway in BMSCs. Inhibition of RUNX2 expression in osteoblasts by siRNA or addition of noggin to the culture medium of BMSCs reduced the effects of osteogenic differentiation induced by isoquercitrin. CONCLUSIONS: These data suggest that isoquercitrin is a natural potential osteoinductive compound and might be valuable for the prevention/treatment of bone disorders.

Cellular localization of ATBF1 protein and its functional implication in breast epithelial cells.

ATBF1, a large transcription factor, was normally localized in nuclei, and its mislocalization to cytoplasm was reported in multiple cancers. However, localization of ATBF1 in breast epithelial cells and its potential functions were unknown. Here, we investigated ATBF1 localization via immunofluorescence staining in different kinds of breast epithelial cells. In MCF10A cells and normal mice mammary gland tissues, ATBF1 was mainly localized in nuclei. Knockdown of ATBF1 expression in MCF10A cells by siRNA promoted cell proliferation. Moreover, ATBF1 was co-localized with chromosome during mitosis, indicating its potential function in mitosis. In an estrogen receptor (ER)-positive breast cancer cell line (MCF7), estrogen induced ATBF1 translocation from cytoplasm to nuclei in an ER dependent pathway. In ER-negative cells (Hs578T and MDA-MB-231), ATBF1 was co-localized with GM130 in cytoplasm, indicating ATBF1 localization was associated with protein modification in golgi body. The results were beneficial for intensive investigation of ATBF1's function with different cellular localization in breast cancer.

[The Value of Early Diastolic Transmitral Velocity to Early Mitral Anulus Diastolic Velocity Ratio for Pulmonary Edema in Severe Sepsis Patients].

OBJECTIVES: To determine the association between the value of early diastolic transmitral velocity to early mitral anulus diastolic velocity ratio (E/E')measured by bedside ultrasound and pulmonary edema in severe sepsis (including septic shock) patients. METHODS: Data were obtained from the critical ultrasound database between November 2014 and August 2015. The severe sepsis (including septic shock) patients were eligible, but those with chronic heart disease or acute heart failure were excluded. Pulmonary edema was quantified by lung ultrasound score. The patients were divided into two groups according to lateral E/E'. E/E'-high group was defined as the lateral E/E'>8, and the others were in E/E'-low group. The severity and distribution of pulmonary edema were compared between the two groups. The correlation analysis and logistic regression analysis were performed to determine whether E/E' was the independent risk factor of pulmonary edma. RESULTS: There were 82 cases included. The lung ultrasound score of E/E'-high group was significantly higher than that of E/E'-low group ( P=0.007). There was no statistic difference of pulmonary edema severity in the bilateral 5 th and 6 th ultrasound exam areas, but E/E'-high group were more severe in the bilateral 1 th to 4 th ultrasound exam areas ( P=0.004). Linear-regression analysis demonstrated that E/E' and inferior vena cava diameter were independent risk factors of pulmonary edema (standardized regression coefficients were 0.425 and 0.249, respectively, P<0.05). CONCLUSIONS: E/E' is the independent risk factor of pulmonary edema in severe sepsis and septic shock patients.

[Research Advances in Regeneration of Soft Tissue with Small Intestinal Submucosa].

Small intestinal submucosa(SIS)is a natural decellularized extracellular matrix material.Due to its excellent biocompatibility,unique biomechanical properties and biological activity,it has been widely used as a scaffold in regenerative medicine.This article reviews the recent progress in the characterization and medical application of SIS respectively.The specific biological properties of the SIS,as well as its interaction with cells,are highlighted.Some of the SIS products and clinical cases are also reviewed and discussed.

Cerivastatin represses atherogenic gene expression through the induction of KLF2 via isoprenoid metabolic pathways.

Earlier clinical studies have reported that cerivastatin has an anti-atherosclerotic effect that is unique among the statins. In our study, human THP-1 macrophage cells were used to study the effects of various statins on the expressions of the atherosclerotic genes and Kruppel-like factor 2 (KLF2). Cerivastatin significantly inhibited the two atherosclerotic genes, monocyte chemoattractant protein-1 (MCP-1) and C-C chemokine receptor type 2 (CCR2) at both the mRNA and protein levels, while the other statins did not. Accordingly, cerivastatin was also the most potent inducer of KLF2 transcription in the macrophages. An siRNA-induced reduction in KLF2 expression blocked the inhibition of MCP-1 and CCR2 by cerivastatin. When the cells were further treated with mevalonate, farnesylpyrophosphate (FPP) or geranylgeranyl pyrophosphate (GGPP), the effects of cerivastatin on KLF2, MCP-1 and CCR2 were obviously reversed. Thus, the results showed that cerivastatin was a potent inhibitor of the inflammation genes MCP-1 and CCR2 through the induction of KLF2. The regulation of MCP-1, CCR2 and KLF2 by cerivastatin was isoprenoid pathway dependent. Our studies suggest that the effect of cerivastatin on atherosclerotic genes and KLF2 expression may contribute to the cardioprotection observed in reported clinical studies.

Distinguished biomimetic dECM system facilitates early detection of metastatic breast cancer cells.

Breast cancer is the most prevalent malignant tumor affecting women's health. Bone is the most common distant metastatic organ, worsening the quality of life and increasing the mortality of patients. Early detection of breast cancer bone metastasis is urgent for halting disease progression and improving tumor prognosis. Recently, extracellular matrix (ECM) with biomimetic tissue niches opened a new avenue for tumor models in vitro. Here, we developed a biomimetic decellularized ECM (dECM) system to recapitulate bone niches at different situations, bone mimetic dECM from osteoblasts (BM-ECM) and bone tumor mimetic dECM from osteosarcoma cells (OS-ECM). The two kinds of dECMs exhibited distinct morphology, protein composition, and distribution. Interestingly, highly metastatic breast cancer cells tended to adhere and migrate on BM-ECM, while lowly metastatic breast cancer cells preferred the OS-ECM niche. Epithelial-to-mesenchymal transition was a potential mechanism to initiate the breast cancer cell migration on different biomimetic dECMs. Importantly, in the nude mice model, the dECM system captured metastatic breast cancer cells as early as 10 days after orthotopic transplantation in mammary gland pads, with higher signal on BM-ECM than that on OS-ECM. Collectively, the biomimetic dECM system might be a promising tumor model to distinguish the metastatic ability of breast cancer cells in vitro and to facilitate early detection of metastatic breast cancer cells in vivo, contributing to the diagnosis of breast cancer bone metastasis.

Preclinical Evaluation of Bioactive Small Intestinal Submucosa-PMMA Bone Cement for Vertebral Augmentation.

In vertebroplasty and kyphoplasty, bioinert poly(methyl methacrylate) (PMMA) bone cement is a conventional filler employed for quick stabilization of osteoporotic vertebral compression fractures (OVCFs). However, because of the poor osteointegration, excessive stiffness, and high curing temperature of PMMA, the implant loosens, the adjacent vertebrae refracture, and thermal necrosis of the surrounding tissue occurs frequently. This investigation addressed these issues by incorporating the small intestinal submucosa (SIS) into PMMA (SIS-PMMA). In vitro analyses revealed that this new SIS-PMMA bone cement had improved porous structure, as well as reduced compressive modulus and polymerization temperature compared with the original PMMA. Furthermore, the handling properties of SIS-PMMA bone cement were not significantly different from PMMA. The in vitro effect of PMMA and SIS-PMMA was investigated on MC3T3-E1 cells via the Transwell insert model to mimic the clinical condition or directly by culturing cells on the bone cement samples. The results indicated that SIS addition substantially enhanced the proliferation and osteogenic differentiation of MC3T3-E1 cells. Additionally, the bone cement's biomechanical properties were also assessed in a decalcified goat vertebrae model with a compression fracture, which indicated the SIS-PMMA had markedly increased compressive strength than PMMA. Furthermore, it was proved that the novel bone cement had good biosafety and efficacy based on the International Standards and guidelines. After 12 weeks of implantation, SIS-PMMA indicated significantly more osteointegration and new bone formation ability than PMMA. In addition, vertebral bodies with cement were also extracted for the uniaxial compression test, and it was revealed that compared with the PMMA-implanted vertebrae, the SIS-PMMA-implanted vertebrae had greatly enhanced maximum strength. Overall, these findings indicate the potential of SIS to induce efficient fixation between the modified cement surface and the host bone, thereby providing evidence that the SIS-PMMA bone cement is a promising filler for clinical vertebral augmentation.

Exosome-based delivery nanoplatforms: next-generation theranostic platforms for breast cancer.

Breast cancer is the most frequent type of malignancy, and the leading cause of cancer-related death in women across the globe. Exosomes are naturally derived 50-150 nm nanovesicles with a variety of bioactive molecules to regulate the complex intracellular pathways involved in all stages of breast cancer development. Exosomes are also considered as a potential new generation of natural nanocarriers due to their intriguing endogenous functionalities. Recently, the development of exosome-based delivery nanoplatforms that combine the inherent unique advantages of exosomes with advanced nanotechnology has emerged as a promising area. In the present review, we first declare the fundamental principles of the relationship between exosomes and breast cancer, ranging from the initiation and progression of breast cancer, to drug resistance. More efforts are made to present a comprehensive overview of the recent advances of exosome nanotechnology for breast cancer therapy, including natural exosomes from different cell types, engineered exosomes with cargo loading and membrane modification, and artificial bionic exosomes with more stable and scalable properties. Based on the recent advanced nanotechnologies, exosome-based delivery nanoplatforms have been considered as the next-generation theranostic platforms, which sheds the light on the achievement of the clinical translation of exosomes for breast cancer therapy.

BMSCs and Osteoblast-Engineered ECM Synergetically Promotes Osteogenesis and Angiogenesis in an Ectopic Bone Formation Model.

Bone mesenchymal stem cells (BMSCs) have been extensively used in bone tissue engineering because of their potential to differentiate into multiple cells, secrete paracrine factors, and attenuate immune responses. Biomaterials are essential for the residence and activities of BMSCs after implantation in vivo. Recently, extracellular matrix (ECM) modification with a favorable regenerative microenvironment has been demonstrated to be a promising approach for cellular activities and bone regeneration. The aim of the present study was to evaluate the effects of BMSCs combined with cell-engineered ECM scaffolds on osteogenesis and angiogenesis in vivo. The ECM scaffolds were generated by osteoblasts on the small intestinal submucosa (SIS) under treatment with calcium (Ca)-enriched medium and icariin (Ic) after decellularization. In a mouse ectopic bone formation model, the SIS scaffolds were demonstrated to reduce the immune response, and lower the levels of immune cells compared with those in the sham group. Ca/Ic-ECM modification inhibited the degradation of the SIS scaffolds in vivo. The generated Ca/Ic-SIS scaffolds ectopically promoted osteogenesis according to the results of micro-CT and histological staining. Moreover, BMSCs on Ca/Ic-SIS further increased the bone volume percentage (BV/TV) and bone density. Moreover, angiogenesis was also enhanced by the Ca/Ic-SIS scaffolds, resulting in the highest levels of neovascularization according to the data ofCD31 staining. In conclusion, osteoblast-engineered ECM under directional induction is a promising strategy to modify biomaterials for osteogenesis and angiogenesis. BMSCs synergetically improve the properties of ECM constructs, which may contribute to the repair of large bone defects.

Enhancement of Tendon Repair Using Tendon-Derived Stem Cells in Small Intestinal Submucosa via M2 Macrophage Polarization.

(1) Background: Reconstruction of Achilles tendon defects and prevention of postoperative tendon adhesions were two serious clinical problems. In the treatment of Achilles tendon defects, decellularized matrix materials and mesenchymal stem cells (MSCs) were thought to address both problems. (2) Methods: In vitro, cell adhesion, proliferation, and tenogenic differentiation of tendon-derived stem cells (TDSCs) on small intestinal submucosa (SIS) were evaluated. RAW264.7 was induced by culture medium of TDSCs and TDSCs-SIS scaffold groups. A rat Achilles tendon defect model was used to assess effects on tendon regeneration and antiadhesion in vivo. (3) Results: SIS scaffold facilitated cell adhesion and tenogenic differentiation of TDSCs, while SIS hydrogel coating promoted proliferation of TDSCs. The expression of TGF-ß and ARG-1 in the TDSCs-SIS scaffold group were higher than that in the TDSCs group on day 3 and 7. In vivo, the tendon regeneration and antiadhesion capacity of the implanted TDSCs-SIS scaffold was significantly enhanced. The expression of CD163 was significantly highest in the TDSCs-SIS scaffold group; meanwhile, the expression of CD68 decreased more significantly in the TDSCs-SIS scaffold group than the other two groups. (4) Conclusion: This study showed that biologically prepared SIS scaffolds synergistically promote tendon regeneration with TDSCs and achieve antiadhesion through M2 polarization of macrophages.

ATBF1 Participates in Dual Functions of TGF-ß via Regulation of Gene Expression and Protein Translocalization.

TGF-ß is a critical cytokine to regulate multiple pathophysiological functions. For tumor development and progression, TGF-ß was reported to play dual functions as a tumor suppressor and epithelial-mesenchymal transition (EMT) inducer. The mechanism of the TGF-ß signaling pathway is essential for TGF-ß/Smad-targeted therapy in clinic. Here, ATBF1 was demonstrated to participate in dual functions of TGF-ß via different ways. On one hand, ATBF1 expression level was associated with EMT and migration induced by TGF-ß. After TGF-ß treatment, ATBF1 expression was reduced in a dose- and time-dependent manner, along with the alteration of cell morphology and EMT marker expression. Knockdown of ATBF1 by siRNA further promoted EMT progression and cell migration. On the other hand, ATBF1 localization was associated with cell proliferation inhibited by TGF-ß. The number of cells with nucleus localization of ATBF1 in TGF-ß activation group was much higher than that in control group. After that, knockdown of ATBF1 by siRNA rescued the inhibition of cell proliferation affected by TGF-ß. These data revealed that ATBF1 is a key gene for the dual roles of TGF-ß, which may contribute to future therapy.

Initial assessment of treatment of talar posterior process fractures with open reduction and percutaneous fixation.

The purpose of this study was to provide an initial assessment of treatment for talar posterior process fractures using open reduction and internal fixation (ORIF) through posteromedial approach and percutaneous screw fixation. From January 2014 to December 2018, 12 cases with displaced fracture of talar posterior process were treated in our department. The clinical and radiological results were assessed after 4 and 12 months of operation with Visual Analog Scale (VAS) pain and American Orthopedic Foot and Ankle Society (AOFAS) scores. ORIF was performed in four of the cases and percutaneous screw fixation was performed in eight of the cases. The average follow-up period was 13 months. Complications such as wound infection, nerve injury, screw loosening, malunion or nonunion of fracture were absent. For clinical assessment, considerable mprovements were observed for the AOFAS and VAS scores at 4 and 12 months postoperatively for both techniques. There was no significant difference for AOFAS scores and VAS scores between the two techniques (p > 0.05). Both techniques showed good functional outcome and were performed for posterior talar process fracture following the fracture displacement guidelines. Percutaneous screw fixation treatment with computer-assisted three-dimensional evaluation shortened the operation time and reduced incidences of surgical complications.

Osteoblast/fibroblast coculture derived bioactive ECM with unique matrisome profile facilitates bone regeneration.

Extracellular matrix (ECM) with mimetic tissue niches was attractive to facilitate tissue regeneration in situ via recruitment of endogenous cells and stimulation of self-healing process. However, how to engineer the complicate tissue specific ECM with unique matrisome in vitro was a challenge of ECM-based biomaterials in tissue engineering and regenerative medicine. Here, we introduced coculture system to engineer bone mimetic ECM niche guided by cell-cell communication. In the cocultures, fibroblasts promoted osteogenic differentiation of osteoblasts via extracellular vesicles. The generated ECM (MN-ECM) displayed a unique appearance of morphology and biological components. The advantages of MN-ECM were demonstrated with promotion of multiple cellular behaviors (proliferation, adhesion and osteogenic mineralization) in vitro and bone regeneration in vivo. Moreover, proteomic analysis was used to clarify the molecular mechanism of MN-ECM, which revealed a specific matrisome signature. The present study provides a novel strategy to generate ECM with tissue mimetic niches via cell-cell communication in a coculture system, which forwards the development of tissue-bioactive ECM engineering along with deepening the understanding of ECM niches regulated by cells for bone tissue engineering.

ECM coating modification generated by optimized decellularization process improves functional behavior of BMSCs.

Bone mesenchymal stem cells (BMSCs) have been widely applied in tissue engineering and regenerative medicine. However, small number of BMSCs and loss of stem cell characteristics after expansion in vitro limited clinical use of BMSCs. In the present study, osteoblasts were cultured to lay down extracellular matrix (ECM) and then the cells were removed (decellularization) to generate ECM coating substrates. The decellularization process was optimized to maximally remove cells and cellular components, along with integrated ECM retained which was demonstrated to be beneficial for BMSCs expansion in vitro. After decellularization, only less than 2% of residual DNA and cellular proteins were detected in TFFF-ECM (decellularized by triton X-100 (T) and three freeze/thaw cycles (FFF)), which was much less than that in TN-ECM generated by traditional decellularization method (triton X-100 (T) and NH4OH (N)). Meanwhile, ECM components and structure were preserved best after decellularization by TFFF method. More ECM proteins were detected, and structure proteins (fibronectin and collagen) exhibited as classic network fibers in TFFF-ECM. Functionally, all kinds of decellularized ECM (dECM) were demonstrated to promote BMSCs proliferation and osteogenic differentiation capacity, thus maintain the stemness of BMSCs. Importantly, cells cultured on TFFF-ECM grew faster than the cells on other kinds of dECM at early stage and TFFF-ECM was beneficial to preserve stemness of BMSCs with high expression of OCT4 and NANOG when cultured in vitro. Proteomic analysis showed the proteins in ECM functioned in multiple biological activities and signaling pathways, which contributed to stemness maintenance of BMSC. Thus, the mild decellularization process optimized in this study enhanced the effectiveness of dECM for BMSCs culture in vitro and maybe further applied to BMSCs based tissue repair.

In-Situ Mutation Detection by Magnetic Beads-Probe Based on Single Base Extension and Its Application in Genotyping of Hepatitis B Virus Pre-C Region 1896nt Locus Single Nucleotide Polymorphisms.

Hepatitis B virus (HBV) is closely related to occurrence and development of viral hepatitis. A mutation of 1896nt locus in its pre-C region can promote replication of HBV DNA and improve stability of pre-genome RNA structure, and can even help HBV evade immune clearance. In this study, magnetic beads-probe (MBs@probe) method, combined with single base extension (SBE) technology, was developed for in-situ mutation detection of HBV pre-C region 1896nt locus. Before successfully completing the genotyping of 165 HBV samples, the crucial reaction conditions were first optimized, such as SBE temperature, MBs size and amount, and probe concentration on the surface of MBs. Experimental results showed that these conditions had significant effects on MBs@probe in-situ mutation detection. Comprehensive considerations, such as 58 °C of SBE temperature, high fluorescence intensity and signal-to-noise ratios (SNRs) were obtained when MBs@probe complex was made by 100 µg of 300 nm-MBs and 3.0 µM of probes in the system. Finally, 1896nt locus mutation in pre-C region of 165 HBV samples was successfully genotyped, among which 71 HBV samples were wild types and the remaining 94 samples were mutant types. Meanwhile, 14 randomly chosen samples were taken to further analyze fluorescence intensity and SNRs respectively, and sequencing results for the first two samples were consistent with results from the MBs@probe in-situ mutation detection method. Compared with two-color fluorescence hybridization (TCFH) genotyping technology, this method generally improves the SNRs to more than 10 (which is more than 2-fold), has higher reliability and is more suitable to detect SNPs for known sites.

Icariin induces osteogenic differentiation in vitro in a BMP- and Runx2-dependent manner.

To effectively treat bone diseases using bone regenerative medicine, there is an urgent need to develop safe cheap drugs that can potently induce bone formation. Here, we demonstrate the osteogenic effect of icariin, the main active compound of Epimedium pubescens. Icariin induced osteogenic differentiation in pre-osteoblastic MC3T3-E1 cells and mouse primary osteoblasts. Icariin upregulated the mRNA expression levels of the osteoblast marker genes runt-related transcription factor 2 (Runx2) and inhibitor of DNA-binding 1 (Id-1). The osteogenic effect was inhibited by the introduction of Smad6 or dominant-negative Runx2, as well as Noggin treatment. Furthermore, icariin induced the mRNA expression of bone morphogenetic protein (BMP)-4. These data suggest that icariin exerts its potent osteogenic effect through induction of Runx2 expression, production of BMP-4 and activation of BMP signaling. The extremely low cost of icariin and its high abundance make it appealing for bone regenerative medicine.