scholarly journals Identification and characterization of novel IGFBP5 interacting protein: evidence IGFBP5-IP is a potential regulator of osteoblast cell proliferation

2006 ◽  
Vol 290 (3) ◽  
pp. C900-C906 ◽  
Author(s):  
Yousef G. Amaar ◽  
Blanca Tapia ◽  
Shin-Tai Chen ◽  
David J. Baylink ◽  
Subburaman Mohan

Insulin-like growth factor binding protein-5 (IGFBP5) is a multifunctional protein, which acts not only as a traditional binding protein, but also functions as a growth factor independent of IGFs to stimulate bone formation. It has been predicted that the intrinsic growth factor action of IGFBP5 involves binding of IGFBP5 to a putative receptor to induce downstream signaling pathways and/or nuclear translocation of IGFBP5 to influence transcription of genes involved in osteoblast cell proliferation/differentiation. Our study indentified proteins that bound to IGFBP5 using IGFBP5 as bait in a yeast two-hybrid screen of the U2 human osteosarcoma cell cDNA library. One of the clones that interacted strongly with the bait under high-stringency conditions corresponded to a novel IGFBP5 interacting protein (IGFBP5-IP) encoded by a gene that resides in mouse chromosome 10. The interaction between IGFBP5-IP and IGFBP5 is confirmed by in vitro coimmunoprecipitation studies that used pFlag and IGFBP5 polyclonal antibody, and cell lysates overexpressing both IGFBP5-IP and IGFBP5. Northern blot and RT-PCR analysis showed that the IGFBP-IP is expressed in both untransformed normal human osteoblasts and in osteosarcoma cell lines, which are known to produce IGFBP5. To determine the roles of IGFBP5-IP, we evaluated the effect of blocking the expression of IGFBP5-IP on osteoblast proliferation. We found that using a IGFBP5-IP-specific small interfering-hairpin plasmid resulted in a decrease in both basal and IGFBP5-induced osteoblast cell proliferation. On the basis of these findings, we predict that IGFBP5-IP may act as intracellular mediator of growth promoting actions of IGFBP5 and perhaps other osteoregulatory agents in bone cells.

2000 ◽  
Vol 15 (1) ◽  
pp. 68-81 ◽  
Author(s):  
Sarah L. Dallas ◽  
Douglas R. Keene ◽  
Scott P. Bruder ◽  
Juha Saharinen ◽  
Lynn Y. Sakai ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Menglin Zou ◽  
Jingfeng Zou ◽  
Xingxing Hu ◽  
Weishuai Zheng ◽  
Mingyang Zhang ◽  
...  

Despite past extensive studies, the mechanisms underlying pulmonary fibrosis (PF) still remain poorly understood. The aberrantly activated lung myofibroblasts, predominantly emerging through fibroblast-to-myofibroblast differentiation, are considered to be the key cells in PF, resulting in excessive accumulation of extracellular matrix (ECM). Latent transforming growth factor-β (TGFβ) binding protein-2 (LTBP2) has been suggested as playing a critical role in modulating the structural integrity of the ECM. However, its function in PF remains unclear. Here, we demonstrated that lungs originating from different types of patients with PF, including idiopathic PF and rheumatoid arthritis-associated interstitial lung disease, and from mice following bleomycin (BLM)-induced PF were characterized by increased LTBP2 expression in activated lung fibroblasts/myofibroblasts. Moreover, serum LTBP2 was also elevated in patients with COVID-19-related PF. LTBP2 silencing by lentiviral shRNA transfection protected against BLM-induced PF and suppressed fibroblast-to-myofibroblast differentiation in vivo and in vitro. More importantly, LTBP2 overexpression was able to induce differentiation of lung fibroblasts to myofibroblasts in vitro, even in the absence of TGFβ1. By further mechanistic analysis, we demonstrated that LTBP2 silencing prevented fibroblast-to-myofibroblast differentiation and subsequent PF by suppressing the phosphorylation and nuclear translocation of NF-κB signaling. LTBP2 overexpression-induced fibroblast-to-myofibroblast differentiation depended on the activation of NF-κB signaling in vitro. Therefore, our data indicate that intervention to silence LTBP2 may represent a promising therapy for PF.


2009 ◽  
Vol 7 (10) ◽  
pp. 1157-1163 ◽  
Author(s):  
Christoph Schmid ◽  
Irene Schläpfer ◽  
Margaretha Waldvogel ◽  
Jürgen Zapf ◽  
E. Rudolf Froesch

2020 ◽  
Vol 20 (18) ◽  
pp. 1628-1639
Author(s):  
Sergi Gómez-Ganau ◽  
Josefa Castillo ◽  
Andrés Cervantes ◽  
Jesus Vicente de Julián-Ortiz ◽  
Rafael Gozalbes

Background: The Epidermal Growth Factor Receptor (EGFR) is a transmembrane protein that acts as a receptor of extracellular protein ligands of the epidermal growth factor (EGF/ErbB) family. It has been shown that EGFR is overexpressed by many tumours and correlates with poor prognosis. Therefore, EGFR can be considered as a very interesting therapeutic target for the treatment of a large variety of cancers such as lung, ovarian, endometrial, gastric, bladder and breast cancers, cervical adenocarcinoma, malignant melanoma and glioblastoma. Methods: We have followed a structure-based virtual screening (SBVS) procedure with a library composed of several commercial collections of chemicals (615,462 compounds in total) and the 3D structure of EGFR obtained from the Protein Data Bank (PDB code: 1M17). The docking results from this campaign were then ranked according to the theoretical binding affinity of these molecules to EGFR, and compared with the binding affinity of erlotinib, a well-known EGFR inhibitor. A total of 23 top-rated commercial compounds displaying potential binding affinities similar or even better than erlotinib were selected for experimental evaluation. In vitro assays in different cell lines were performed. A preliminary test was carried out with a simple and standard quick cell proliferation assay kit, and six compounds showed significant activity when compared to positive control. Then, viability and cell proliferation of these compounds were further tested using a protocol based on propidium iodide (PI) and flow cytometry in HCT116, Caco-2 and H358 cell lines. Results: The whole six compounds displayed good effects when compared with erlotinib at 30 μM. When reducing the concentration to 10μM, the activity of the 6 compounds depends on the cell line used: the six compounds showed inhibitory activity with HCT116, two compounds showed inhibition with Caco-2, and three compounds showed inhibitory effects with H358. At 2 μM, one compound showed inhibiting effects close to those from erlotinib. Conclusion: Therefore, these compounds could be considered as potential primary hits, acting as promising starting points to expand the therapeutic options against a wide range of cancers.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zehua Zhang ◽  
Fei Dai ◽  
Fei Luo ◽  
Wenjie Wu ◽  
Shuai Zhang ◽  
...  

AbstractOsteosarcoma is a malignant osteoblastic tumor that can gravely endanger the lives and health of children and adolescents. Therefore, there is an urgent need to explore new biomarkers for osteosarcoma and determine new targeted therapies to improve the efficacy of osteosarcoma treatment. Diaphanous related formin 3 (DIAPH3) promotes tumorigenesis in hepatocellular carcinoma and lung adenocarcinoma, suggesting that DIAPH3 may be a target for tumor therapy. To date, there have been no reports on the function of DIAPH3 in osteosarcoma. DIAPH3 protein expression in osteosarcoma tissues and healthy bone tissues adjacent to cancer cells was examined by immunohistochemical staining. DIAPH3 mRNA expression correlates with overall survival and reduced disease-free survival. DIAPH3 protein is upregulated in osteosarcoma tissues, and its expression is significantly associated with tumor size, tumor stage, node metastasis, and distant metastasis. Functional in vitro experiments revealed that DIAPH3 knockdown suppressed cell proliferation and suppressed cell migration and invasion of osteosarcoma cell lines MG-63 and HOS. Functional experiments demonstrated that DIAPH3 knockdown inhibited subcutaneous tumor growth and lung metastasis in vivo. In conclusion, DIAPH3 expression can predict the clinical outcome of osteosarcoma. In addition, DIAPH3 is involved in the proliferation and metastasis of osteosarcoma, and as such, DIAPH3 may be a potential therapeutic target for osteosarcoma.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Mingwu Deng ◽  
Xiangsheng Wang ◽  
Ziyou Yu ◽  
Yizuo Cai ◽  
Wei Liu ◽  
...  

Abstract Background Tissue expansion techniques play an important role in plastic surgery. How to improve the quality of the expanded skin and shorten the expansion period are still worth investigating. Our previous studies found that a cell-free fat extract (CEFFE) possessed pro-angiogenic and pro-proliferative activities. However, the role of CEFFE on tissue expansion has remained unclear. The purpose of this study was to evaluate the effect of CEFFE on tissue expansion. Methods A rat tissue expansion model was used. Animals were treated with CEFFE by subcutaneous injection. After 4 weeks of tissue expansion, the skin necrosis and retraction rates were evaluated, the thicknesses of the epidermis and dermis were determined by histological analyses, blood vessel density was measured by anti-CD31 staining, cell proliferation was assessed by proliferating cell nuclear antigen staining, and the expression of specific proteins was evaluated by western blot analyses. In addition, the effects of CEFFE on the proliferation and cell cycle of cultured HaCaT cells were evaluated in vitro. Results CEFFE treatment significantly decreased the necrosis rate and retraction of the expanded skin. The thickness of the epidermal and dermal layers was higher in CEFFE-treated compared to untreated skin. The density of blood vessels and cell proliferation in the epidermis of the expanded skin was improved by CEFFE treatment. In addition, CEFFE treatment significantly increased the expression of the vascular endothelial growth factor receptor, epidermal growth factor receptor, collagen type 1, and collagen type 3. CEFFE also increased the proliferation of HaCaT cells in culture. Conclusions CEFFE improves the quality of the expanded skin by promoting angiogenesis and cell proliferation. It could be potentially used clinically for augmenting tissue expansion.


2021 ◽  
Author(s):  
Can Chen ◽  
Yi Zong ◽  
Jiaojiao Tang ◽  
Ruisheng Ke ◽  
Lizhi Lv ◽  
...  

Background: The aim of this study was to investigate the role of miR-369-3p in hepatocellular carcinoma (HCC). Materials & methods: The expression levels of miR-369-3p were detected using the quantitative real-time reverse transcription-PCR analysis. The cell counting kit-8 and transwell assays were used to explore the effects of miR-369-3p on cell proliferation, migration and invasion of HCC cells. Results: The miR-369-3p expression was downregulated in HCC tissues and cell lines, in comparison to the normal controls, respectively. In vitro, overexpression of miR-369-3p in Hep 3B and Huh7 cells inhibited cell proliferation, migration and invasion. SOX4 was a direct target of miR-369-3p. Conclusion: Our results suggested that miR-369-3p may be a tumor suppressor in HCC by targeting SOX4.


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