Osteoactivin promotes osteoblast adhesion through HSPG and alphavbeta1 integrin.
3T3 Cells; Actin Cytoskeleton/physiology; ADHESION; Alkaline Phosphatase/biosynthesis; Animals; Antibodies/immunology; Cell Adhesion; Cell Differentiation; Cell Line; Cell Proliferation; Chlorates/pharmacology; Extracellular Signal-Regulated MAP Kinases/biosynthesis; Eye Proteins/genetics/immunology/*metabolism; Focal Adhesion Kinase 1/biosynthesis; Focal Adhesions; Heparan Sulfate Proteoglycans/*metabolism; Heparin/pharmacology; Inbred C57BL; INTEGRIN; Membrane Glycoproteins/genetics/immunology/*metabolism; Mice; OSTEOACTIVIN; OSTEOBLAST; OSTEOBLAST DIFFERENTIATION; Osteoblasts/*physiology; Osteogenesis/physiology; Protein Binding; Rats; Receptors; Recombinant Proteins; Vitronectin/immunology/*metabolism
Osteoactivin (OA), also known as glycoprotein nmb (gpnmb) plays an important role in the regulation of osteoblast differentiation and function. OA induced osteoblast differentiation and function in vitro by stimulating alkaline phosphatase (ALP) activity, osteocalcin production, nodule formation, and matrix mineralization. Recent studies reported a role for OA in cell adhesion and integrin binding. In this study, we demonstrate that recombinant osteoactivin (rOA) as a matricellular protein stimulated adhesion, spreading and differentiation of MC3T3-E1 osteoblast-like cells through binding to alphav beta1 integrin and heparan sulfated proteoglycans (HSPGs). MC3T3-E1 cell adhesion to rOA was blocked by neutralizing anti-OA or anti-alphav and beta1 integrin antibodies. rOA stimulated-osteoblast adhesion was also inhibited by soluble heparin and sodium chlorate. Interestingly, rOA stimulated-osteoblast adhesion promoted an increase in FAK and ERK activation, resulting in the formation of focal adhesions, cell spreading and enhanced actin cytoskeleton organization. In addition, differentiation of primary osteoblasts was augmented on rOA coated-wells marked by increased alkaline phosphatase staining and activity. Taken together, these data implicate OA as a matricellular protein that stimulates osteoblast adhesion through binding to alphav beta1 integrin and cell surface HSPGs, resulting in increased cell spreading, actin reorganization, and osteoblast differentiation with emphasis on the positive role of OA in osteogenesis.
Moussa Fouad M; Hisijara Israel Arango; Sondag Gregory R; Scott Ethan M; Frara Nagat; Abdelmagid Samir M; Safadi Fayez F
Journal of cellular biochemistry
2014
2014-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/jcb.24760" target="_blank" rel="noreferrer noopener">10.1002/jcb.24760</a>
Macrophage-Associated Osteoactivin/GPNMB Mediates Mesenchymal Stem Cell Survival, Proliferation, and Migration Via a CD44-Dependent Mechanism.
*CD44; *M2 MACROPHAGES; *MSC; *OA/GPNMB; Animals; Cell Movement/*physiology; Cell Proliferation/*physiology; Cell Survival/physiology; Eye Proteins/genetics/*metabolism; Hyaluronan Receptors/genetics/*metabolism; Knockout; Macrophages/cytology/*metabolism; MAP Kinase Signaling System/physiology; Membrane Glycoproteins/genetics/*metabolism; Mesenchymal Stem Cells/cytology/*metabolism; Mice
Although MSCs have been widely recognized to have therapeutic potential in the repair of injured or diseased tissues, it remains unclear how functional activities of mesenchymal stem cells (MSCs) are influenced by the surrounding inflammatory milieu at the site of tissue injury. Macrophages constitute an essential component of innate immunity and have been shown to exhibit a phenotypic plasticity in response to various stimuli, which play a central role in both acute inflammation and wound repair. Osteoactivin (OA)/Glycoprotein non-metastatic melanoma protein B (GPNMB), a transmembrane glycoprotein that plays a role in cell differentiation, survival, and angiogenesis. The objective of this study was to investigate the potential role of OA/GPNMB in macrophage-induced MSC function. We found that reparative M2 macrophages express significantly greater levels of OA/GPNMB than pro-inflammatory M1 macrophages. Furthermore, using loss of function and rescue studies, we demonstrated that M2 macrophages-secreted OA/GPNMB positively regulates the viability, proliferation, and migration of MSCs. More importantly, we demonstrated that OA/GPNMB acts through ERK and AKT signaling pathways in MSCs via CD44, to induce these effects. Taken together, our results provide pivotal insight into the mechanism by which OA/GPNMB contributes to the tissue reparative phenotype of M2 macrophages and positively regulates functional activities of MSCs. J. Cell. Biochem. 117:
Yu Bing; Sondag Gregory R; Malcuit Christopher; Kim Min-Ho; Safadi Fayez F
Journal of cellular biochemistry
2016
2016-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/jcb.25394" target="_blank" rel="noreferrer noopener">10.1002/jcb.25394</a>
Osteoactivin induces transdifferentiation of C2C12 myoblasts into osteoblasts.
Alkaline Phosphatase/biosynthesis; Animals; Cell Line; Cell Transdifferentiation/*genetics; Core Binding Factor Alpha 1 Subunit/biosynthesis; Developmental/genetics; Eye Proteins/*genetics/metabolism; Focal Adhesion Protein-Tyrosine Kinases/biosynthesis; Gene Expression Regulation; Humans; Membrane Glycoproteins/*genetics/metabolism; Mice; Myoblasts/cytology/*metabolism; Osteoblasts/cytology/*metabolism
Osteoactivin (OA) is a novel osteogenic factor important for osteoblast differentiation and function. Previous studies showed that OA stimulates matrix mineralization and transcription of osteoblast specific genes required for differentiation. OA plays a role in wound healing and its expression was shown to increase in post fracture calluses. OA expression was reported in muscle as OA is upregulated in cases of denervation and unloading stress. The regulatory mechanisms of OA in muscle and bone have not yet been determined. In this study, we examined whether OA plays a role in transdifferentiation of C2C12 myoblast into osteoblasts. Infected C2C12 with a retroviral vector overexpressing OA under the CMV promoter were able to transdifferentiate from myoblasts into osteoblasts. Immunofluorescence analysis showed that skeletal muscle marker MF-20 was severely downregulated in cells overexpressing OA and contained significantly less myotubes compared to uninfected control. C2C12 myoblasts overexpressing OA showed an increase in expression of bone specific markers such as alkaline phosphatase and alizarin red staining, and also showed an increase in Runx2 protein expression. We also detected increased levels of phosphorylated focal adhesion kinase (FAK) in C2C12 myoblasts overexpressing OA compared to control. Taken together, our results suggest that OA is able to induce transdifferentiation of myoblasts into osteoblasts through increasing levels of phosphorylated FAK.
Sondag Gregory R; Salihoglu Sibel; Lababidi Suzanne L; Crowder Douglas C; Moussa Fouad M; Abdelmagid Samir M; Safadi Fayez F
Journal of cellular physiology
2014
2014-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/jcp.24512" target="_blank" rel="noreferrer noopener">10.1002/jcp.24512</a>
Transgenic Expression of Osteoactivin/gpnmb Enhances Bone Formation In Vivo and Osteoprogenitor Differentiation Ex Vivo.
Animals; Bone and Bones/*metabolism; Bone Density/physiology; Bone Remodeling/genetics/*physiology; Bone Resorption/metabolism; Cell Differentiation/genetics/*physiology; Eye Proteins/genetics/*metabolism; Membrane Glycoproteins/genetics/*metabolism; Mice; Osteoblasts/*cytology; Osteoclasts/*cytology; Osteogenesis/genetics; Protein-Serine-Threonine Kinases/metabolism; Receptor; Receptors; Transforming Growth Factor beta/metabolism; Transforming Growth Factor-beta Type I; Transgenic
Initial identification of osteoactivin (OA)/glycoprotein non-melanoma clone B (gpnmb) was demonstrated in an osteopetrotic rat model, where OA expression was increased threefold in mutant bones, compared to normal. OA mRNA and protein expression increase during active bone regeneration post-fracture, and primary rat osteoblasts show increased OA expression during differentiation in vitro. To further examine OA/gpnmb as an osteoinductive agent, we characterized the skeletal phenotype of transgenic mouse overexpressing OA/gpnmb under the
Frara Nagat; Abdelmagid Samir M; Sondag Gregory R; Moussa Fouad M; Yingling Vanessa R; Owen Thomas A; Popoff Steven N; Barbe Mary F; Safadi Fayez F
Journal of cellular physiology
2016
2016-01
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/jcp.25020" target="_blank" rel="noreferrer noopener">10.1002/jcp.25020</a>
Osteoactivin Promotes Migration of Oral Squamous Cell Carcinomas.
*Cell Movement; Carcinoma; Cell Adhesion; Cell Line; Cell Proliferation; Cell Survival; Enzyme Activation; Gene Expression Regulation; Head and Neck Neoplasms/genetics/*metabolism/pathology; Humans; Integrin beta1/metabolism; Membrane Glycoproteins/genetics/*metabolism; Messenger/metabolism; Mitogen-Activated Protein Kinases/metabolism; Mouth Neoplasms/genetics/*metabolism/pathology; Neoplasm Invasiveness; Neoplastic; Protein Binding; RNA; RNA Interference; Signal Transduction; Squamous Cell Carcinoma of Head and Neck; Squamous Cell/genetics/*metabolism/pathology; Time Factors; Transfection; Tumor
Nearly 50% of patients with oral squamous cell carcinoma (OSCC) die of metastases or locoregional recurrence. Metastasis is mediated by cancer cell adhesion, migration, and invasion. Osteoactivin (OA) overexpression plays a role in metastases in several malignancies. The aims were to determine how integrin interactions modulate OA-induced OSCC cell migration; and to investigate OA effects on cell survival and proliferation. We confirmed OA mRNA and protein overexpression in OSCC cell lines. We assessed OA's interactions with integrins using adhesion inhibition assays, fluorescent immunocytochemistry and co-immunoprecipitation. We investigated OA-mediated activation of mitogen-activated protein kinases (MAPKs) and cell survival. Integrin inhibition effects on OA-mediated cell migration were determined. We assessed effects of OA knock-down on cell migration and proliferation. OA is overexpressed in OSCC cell lines, and serves as a migration-promoting adhesion molecule. OA co-localized with integrin subunits, and co-immunoprecipitated with the subunits. Integrin blocking antibodies, especially those directed against the beta1 subunit, inhibited cell adhesion (P = 0.03 for SCC15 cells). Adhesion to OA activated MAPKs in UMSCC14a cells and OA treatment promoted survival of SCC15 cells. Integrin-neutralizing antibodies enhanced cell migration with OA in the extracellular matrix. OA knock-down resulted in decreased proliferation of SCC15 and SCC25 cells, but did not inhibit cell migration. OA in the extracellular matrix promotes OSCC cell adhesion and migration, and may be a novel target in the prevention of HNSCC spread. J. Cell. Physiol. 231: 1761-1770, 2016. (c) 2015 Wiley Periodicals, Inc.
Arosarena Oneida A; Dela Cadena Raul A; Denny Michael F; Bryant Evan; Barr Eric W; Thorpe Ryan; Safadi Fayez F
Journal of cellular physiology
2016
2016-08
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/jcp.25279" target="_blank" rel="noreferrer noopener">10.1002/jcp.25279</a>
Osteoactivin regulates head and neck squamous cell carcinoma invasion by modulating matrix metalloproteases.
*Cell Movement; Carcinoma; Cell Line; cell lines; Enzymologic; extracellular matrix; Gene Expression Regulation; Head and Neck Neoplasms/*enzymology/genetics/pathology; human; Humans; matrix metalloproteinases; Matrix Metalloproteinases; Membrane Glycoproteins/genetics/*metabolism; Messenger/genetics/metabolism; neoplasm invasion; Neoplasm Invasiveness; Neoplastic; RNA; RNA Interference; Secreted/genetics/*metabolism; Signal Transduction; Squamous Cell Carcinoma of Head and Neck; Squamous Cell/*enzymology/genetics/pathology; Transfection; Tumor
Nearly 60% of patients with head and neck squamous cell carcinoma (HNSCC) die of metastases or locoregional recurrence. Metastasis is mediated by cancer cell migration and invasion, which are in part dependent on extracellular matrix degradation by matrix metalloproteinases. Osteoactivin (OA) overexpression plays a role in metastases in several malignancies, and has been shown to upregulate matrix metalloproteinase (MMP) expression and activity. To determine how OA modulates MMP expression and activity in HNSCC, and to investigate OA effects on cell invasion, we assessed effects of OA treatment on MMP mRNA and protein expression, as well as gelatinase and caseinolytic activity in HNSCC cell lines. We assessed the effects of OA gene silencing on MMP expression, gelatinase and caseinolytic activity, and cell invasion. OA treatment had differential effects on MMP mRNA expression. OA treatment upregulated MMP-10 expression in UMSCC14a (p = 0.0431) and SCC15 (p \textless 0.0001) cells, but decreased MMP-9 expression in UMSCC14a cells (p = 0.0002). OA gene silencing decreased MMP-10 expression in UMSCC12 cells (p = 0.0001), and MMP-3 (p = 0.0005) and -9 (p = 0.0036) expression in SCC25 cells. In SCC15 and SCC25 cells, OA treatment increased MMP-2 (p = 0.0408) and MMP-9 gelatinase activity (p \textless 0.0001), respectively. OA depletion decreased MMP-2 (p = 0.0023) and -9 (p \textless 0.0001) activity in SCC25 cells. OA treatment increased 70 kDa caseinolytic activity in UMSCC12 cells consistent with tissue type plasminogen activator (p = 0.0078). OA depletion decreased invasive capacity of UMSCC12 cells (p \textless 0.0001). OA's effects on MMP expression in HNSCC are variable, and may promote cancer cell invasion.
Arosarena Oneida A; Barr Eric W; Thorpe Ryan; Yankey Hilary; Tarr Joseph T; Safadi Fayez F
Journal of cellular physiology
2018
2018-01
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/jcp.25900" target="_blank" rel="noreferrer noopener">10.1002/jcp.25900</a>
Glycoprotein NMB: an Emerging Role in Neurodegenerative Disease.
Animals; GPNMB; Humans; Immune System/metabolism; Membrane Glycoproteins/chemistry/*metabolism; Nerve Degeneration/pathology; Neurodegeneration; Neurodegenerative Diseases/*metabolism/therapy; Neuroinflammation; Neuroprotection
Neurodegeneration is characterized by severe neuronal loss leading to the cognitive and physical impairments that define various neurodegenerative diseases. Neuroinflammation is one hallmark of neurodegenerative diseases and can ultimately contribute to disease progression. Increased inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1beta (IL-1 beta), and tumor necrosis factor-alpha (TNF-alpha) are associated with Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). Unfortunately, current therapeutic options lack ability to stop or effectively slow progression of these diseases and are primarily aimed at alleviating symptoms. Thus, it is crucial to discover novel treatment candidates for neurodegenerative diseases. Glycoprotein nonmetastatic melanoma protein B (GPNMB) is a type-I transmembrane glycoprotein first identified in a melanoma cell line. GPNMB augments bone mineral deposition by stimulating osteoblast differentiation. Aside from its anabolic function in the bone, emerging evidence suggests that GPNMB has anti-inflammatory and reparative functions. GPNMB has also been demonstrated to be neuroprotective in an animal model of ALS, cerebral ischemia, and other disease models. Given these discoveries, GPNMB should be investigated as a potential therapeutic option for multiple neurodegenerative diseases.
Budge Kevin M; Neal Matthew L; Richardson Jason R; Safadi Fayez F
Molecular neurobiology
2018
2018-06
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1007/s12035-017-0707-z" target="_blank" rel="noreferrer noopener">10.1007/s12035-017-0707-z</a>
Orthosilicic acid, Si(OH)4, stimulates osteoblast differentiation in vitro by upregulating miR-146a to antagonize NF-kappaB activation.
*microRNA; *NF-kappaB; *Osteoblastic differentiation; *Osteoclastic differentiation; *Silicic acid; Animals; Cell Differentiation/*drug effects; Humans; Mesenchymal Stem Cells/*metabolism; Mice; MicroRNAs/*biosynthesis; NF-kappa B/*metabolism; Osteoblasts/*metabolism; Osteogenesis/drug effects; RAW 264.7 Cells; Silicic Acid/*pharmacology
UNLABELLED: Accumulating evidence over the last 40years suggests that silicate from dietary as well as silicate-containing biomaterials is beneficial to bone formation. However, the exact biological role(s) of silicate on bone cells are still unclear and controversial. Here, we report that orthosilicic acid (Si(OH)4) stimulated human mesenchymal stem cells (hMSCs) osteoblastic differentiation in vitro. To elucidate the possible molecular mechanisms, differential microRNA microarray analysis was used to show that Si(OH)4 significantly up-regulated microRNA-146a (miR-146a) expression during hMSC osteogenic differentiation. Si(OH)4 induced miR-146a expression profiling was further validated by quantitative RT-PCR (qRT-PCR), which indicated miR-146a was up-regulated during the late stages of hMSC osteogenic differentiation. Inhibition of miR-146a function by anti-miR-146a suppressed osteogenic differentiation of MC3T3 pre-osteoblasts, whereas Si(OH)4 treatment promoted osteoblast-specific genes transcription, alkaline phosphatase (ALP) production, and mineralization. Furthermore, luciferase reporter assay, Western blotting, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence showed that Si(OH)4 decreased TNFalpha-induced activation of NF-kappaB, a signal transduction pathway that inhibits osteoblastic bone formation, through the known miR-146a negative feedback loop. Our studies established a mechanism for Si(OH)4 to promote osteogenesis by antagonizing NF-kappaB activation via miR-146a, which might be interesting to guide the design of osteo-inductive biomaterials for treatments of bone defects in humans. STATEMENT OF SIGNIFICANCE: Accumulating evidence over 40years suggests that silicate is beneficial to bone formation. However, the biological role(s) of silicate on bone cells are still unclear and controversial. Here, we report that Si(OH)4, the simplest form of silicate, can stimulate human mesenchymal stem cells osteoblastic differentiation. We identified that miR-146a is the expression signature in bone cells treated with Si(OH)4. Further analysis of miR-146a in bone cells reveals that Si(OH)4 upregulates miR-146a to antagonize the activation of NF-kappaB. Si(OH)4 was also shown to deactivate the same
Zhou Xianfeng; Moussa Fouad M; Mankoci Steven; Ustriyana Putu; Zhang Nianli; Abdelmagid Samir; Molenda Jim; Murphy William L; Safadi Fayez F; Sahai Nita
Acta biomaterialia
2016
2016-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.actbio.2016.05.007" target="_blank" rel="noreferrer noopener">10.1016/j.actbio.2016.05.007</a>
Mutation in osteoactivin decreases bone formation in vivo and osteoblast differentiation in vitro.
*Signal Transduction; Alkaline Phosphatase/metabolism; Animals; Apoptosis; Bone and Bones/metabolism/pathology; Cell Differentiation/genetics; Eye Proteins/*genetics; Inbred DBA; Male; Membrane Glycoproteins/*genetics; Mice; Mutation; Newborn; Osteoblasts/cytology/*physiology; Osteocalcin/*genetics; Osteogenesis/*genetics; Phenotype; Receptors; Transforming Growth Factor beta/metabolism
We have previously identified osteoactivin (OA), encoded by Gpnmb, as an osteogenic factor that stimulates osteoblast differentiation in vitro. To elucidate the importance of OA in osteogenesis, we characterized the skeletal phenotype of a mouse model, DBA/2J (D2J) with a loss-of-function mutation in Gpnmb. Microtomography of D2J mice showed decreased trabecular mass, compared to that in wild-type mice [DBA/2J-Gpnmb(+)/SjJ (D2J/Gpnmb(+))]. Serum analysis showed decreases in OA and the bone-formation markers alkaline phosphatase and osteocalcin in D2J mice. Although D2J mice showed decreased osteoid and mineralization surfaces, their osteoblasts were increased in number, compared to D2J/Gpnmb(+) mice. We then examined the ability of D2J osteoblasts to differentiate in culture, where their differentiation and function were decreased, as evidenced by low alkaline phosphatase activity and matrix mineralization. Quantitative RT-PCR analyses confirmed the decreased expression of differentiation markers in D2J osteoblasts. In vitro, D2J osteoblasts proliferated and survived significantly less, compared to D2J/Gpnmb(+) osteoblasts. Next, we investigated whether mutant OA protein induces endoplasmic reticulum stress in D2J osteoblasts. Neither endoplasmic reticulum stress markers nor endoplasmic reticulum ultrastructure were altered in D2J osteoblasts. Finally, we assessed underlying mechanisms that might alter proliferation of D2J osteoblasts. Interestingly, TGF-beta receptors and Smad-2/3 phosphorylation were up-regulated in D2J osteoblasts, suggesting that OA contributes to TGF-beta signaling. These data confirm the anabolic role of OA in postnatal bone formation.
Abdelmagid Samir M; Belcher Joyce Y; Moussa Fouad M; Lababidi Suzanne L; Sondag Gregory R; Novak Kimberly M; Sanyurah Afif S; Frara Nagat A; Razmpour Roshanak; Del Carpio-Cano Fabiola E; Safadi Fayez F
The American journal of pathology
2014
2014-03
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.ajpath.2013.11.031" target="_blank" rel="noreferrer noopener">10.1016/j.ajpath.2013.11.031</a>
Role of inflammation in the aging bones.
*Models; Aging; Aging/*physiology; Animals; Biological; Bone adaptation; Bone and Bones/cytology/immunology/*physiopathology; Bone Marrow Cells/physiology; Bone resorption; Cell Differentiation/*physiology; Cumulative Trauma Disorders/physiopathology; Humans; Inflammation; Inflammation/*physiopathology; Macrophages; Macrophages/*physiology; Osteoblasts; Osteoblasts/*physiology; Osteoclasts; Osteoclasts/*physiology
Chronic inflammation in aging is characterized by increased inflammatory cytokines, bone loss, decreased adaptation, and defective tissue repair in response to injury. Aging leads to inherent changes in mesenchymal stem cell (MSC) differentiation, resulting in impaired osteoblastogenesis. Also, the pro-inflammatory cytokines increase with aging, leading to enhanced myelopoiesis and osteoclastogenesis. Bone marrow macrophages (BMMs) play pivotal roles in osteoblast differentiation, the maintenance of hematopoietic stem cells (HSCs), and subsequent bone repair. However, during aging, little is known about the role of macrophages in the differentiation and function of MSC and HSC. Aged mammals have higher circulating pro-inflammatory cytokines than young adults, supporting the hypothesis of increased inflammation with aging. This review will aid in the understanding of the potential role(s) of pro-inflammatory (M1) and anti-inflammatory (M2) macrophages in differentiation and function of osteoblasts and osteoclasts in relation to aging.
Abdelmagid Samir M; Barbe Mary F; Safadi Fayez F
Life sciences
2015
2015-02
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.lfs.2014.11.011" target="_blank" rel="noreferrer noopener">10.1016/j.lfs.2014.11.011</a>
Osteoactivin inhibition of osteoclastogenesis is mediated through CD44-ERK signaling.
*MAP Kinase Signaling System; *Signal Transduction; Animals; Cell Differentiation; Cells; Cultured; Eye Proteins/*metabolism; Hyaluronan Receptors/*metabolism; Inbred C57BL; Male; Membrane Glycoproteins/*metabolism; Mice; Osteoclasts/*cytology/metabolism; RANK Ligand/metabolism; Recombinant Proteins/metabolism
Osteoactivin is a heavily glycosylated protein shown to have a role in bone remodeling. Previous studies from our lab have shown that mutation in Osteoactivin enhances osteoclast differentiation but inhibits their function. To date, a classical receptor and a signaling pathway for Osteoactivin-mediated osteoclast inhibition has not yet been characterized. In this study, we examined the role of Osteoactivin treatment on osteoclastogenesis using bone marrow-derived osteoclast progenitor cells and identify a signaling pathway relating to Osteoactivin function. We reveal that recombinant Osteoactivin treatment inhibited osteoclast differentiation in a dose-dependent manner shown by qPCR, TRAP staining, activity and count. Using several approaches, we show that Osteoactivin binds CD44 in osteoclasts. Furthermore, recombinant Osteoactivin treatment inhibited ERK phosphorylation in a CD44-dependent manner. Finally, we examined the role of Osteoactivin on receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteolysis in vivo. Our data indicate that recombinant Osteoactivin inhibits RANKL-induced osteolysis in vivo and this effect is CD44-dependent. Overall, our data indicate that Osteoactivin is a negative regulator of osteoclastogenesis in vitro and in vivo and that this process is regulated through CD44 and ERK activation.
Sondag Gregory R; Mbimba Thomas S; Moussa Fouad M; Novak Kimberly; Yu Bing; Jaber Fatima A; Abdelmagid Samir M; Geldenhuys Werner J; Safadi Fayez F
Experimental & molecular medicine
2016
2016-09
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1038/emm.2016.78" target="_blank" rel="noreferrer noopener">10.1038/emm.2016.78</a>
Mutation in Osteoactivin Promotes Receptor Activator of NFkappaB Ligand (RANKL)-mediated Osteoclast Differentiation and Survival but Inhibits Osteoclast Function.
*Mutation; Akt; Animals; bone; bone marrow; Bone Remodeling; Cell Differentiation/*physiology; Cell Survival/*physiology; Eye Proteins/*genetics; Inbred DBA; MAP kinases (MAPKs); Membrane Glycoproteins/*genetics; Mice; osteoactivin; osteoclast; Osteoclasts/*cytology; osteopetrosis; RANK Ligand/metabolism/*physiology; Signal Transduction; X-Ray Microtomography
We previously reported on the importance of osteoactivin (OA/Gpnmb) in osteogenesis. In this study, we examined the role of OA in osteoclastogenesis, using mice with a nonsense mutation in the Gpnmb gene (D2J) and wild-type controls (D2J/Gpnmb(+)). In these D2J mice, micro-computed tomography and histomorphometric analyses revealed increased cortical thickness, whereas total porosity and eroded surface were significantly reduced in D2J mice compared with wild-type controls, and these results were corroborated by lower serum levels of
Abdelmagid Samir M; Sondag Gregory R; Moussa Fouad M; Belcher Joyce Y; Yu Bing; Stinnett Hilary; Novak Kimberly; Mbimba Thomas; Khol Matthew; Hankenson Kurt D; Malcuit Christopher; Safadi Fayez F
The Journal of biological chemistry
2015
2015-08
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1074/jbc.M114.624270" target="_blank" rel="noreferrer noopener">10.1074/jbc.M114.624270</a>
Emerging lung cancer therapeutic targets based on the pathogenesis of bone metastases.
Lung cancer is the second most common cancer and the leading cause of cancer related mortality in both men and women. Each year, more people die of lung cancer than of colon, breast, and prostate cancers combined. It is widely accepted that tumor metastasis is a formidable barrier to effective treatment of lung cancer. The bone is one of the frequent metastatic sites for lung cancer occurring in a large number of patients. Bone metastases can cause a wide range of symptoms that could impair quality of life of lung cancer patients and shorten their survival. We strongly believe that molecular targets (tumor-related and bone microenvironment based) that have been implicated in lung cancer bone metastases hold great promise in lung cancer therapeutics. Thus, this paper discusses some of the emerging molecular targets that have provided insights into the cascade of metastases in lung cancer with the focus on bone invasion. It is anticipated that the information gathered might be useful in future efforts of optimizing lung cancer treatment strategies.
Oyewumi Moses O; Alazizi Adnan; Wehrung Daniel; Manochakian Rami; Safadi Fayez F
International journal of cell biology
2014
1905-7
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1155/2014/236246" target="_blank" rel="noreferrer noopener">10.1155/2014/236246</a>
The glycoprotein GPNMB attenuates astrocyte inflammatory responses through the CD44 receptor.
Astrocyte; CD44; GPNMB; Neuroinflammation; Parkinson's disease
BACKGROUND: Neuroinflammation is one of the hallmarks of neurodegenerative diseases, such as Parkinson's disease (PD). Activation of glial cells, including microglia and astrocytes, is a characteristic of the inflammatory response. Glycoprotein non-metastatic melanoma protein B (GPNMB) is a transmembrane glycoprotein that releases a soluble signaling peptide when cleaved by ADAM10 or other extracellular proteases. GPNMB has demonstrated a neuroprotective role in animal models of ALS and ischemia. However, the mechanism of this protection has not been well established. CD44 is a receptor expressed on astrocytes that can bind GPNMB, and CD44 activation has been demonstrated to reduce NFkappaB activation and subsequent inflammatory responses in macrophages. GPNMB signaling has not been investigated in models of PD or specifically in astrocytes. More recently, genetic studies have linked polymorphisms in GPNMB with risk for PD. Therefore, it is important to understand the role this signaling protein plays in PD. METHODS: We used data mining techniques to evaluate mRNA expression of GPNMB and its receptor CD44 in the substantia nigra of PD and control brains. Immunofluorescence and qPCR techniques were used to assess GPNMB and CD44 levels in mice treated with MPTP. In vitro experiments utilized the immortalized mouse astrocyte cell line IMA2.1 and purified primary mouse astrocytes. The effects of recombinant GPNMB on cytokine-induced astrocyte activation was determined by qPCR, immunofluorescence, and measurement of nitric oxide and reactive oxygen production. RESULTS: Increased GPNMB and CD44 expression was observed in the substantia nigra of human PD brains and in GFAP-positive astrocytes in an animal model of PD. GPNMB treatment attenuated cytokine-induced levels of inducible nitric oxide synthase, nitric oxide, reactive oxygen species, and the inflammatory cytokine IL-6 in an astrocyte cell line and primary mouse astrocytes. Using primary mouse astrocytes from CD44 knockout mice, we found that the anti-inflammatory effects of GPNMB are CD44-mediated. CONCLUSIONS: These results demonstrate that GPNMB may exert its neuroprotective effect through reducing astrocyte-mediated neuroinflammation in a CD44-dependent manner, providing novel mechanistic insight into the neuroprotective properties of GPNMB.
Neal Matthew L; Boyle Alexa M; Budge Kevin M; Safadi Fayez F; Richardson Jason R
Journal of neuroinflammation
2018
2018-03
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1186/s12974-018-1100-1" target="_blank" rel="noreferrer noopener">10.1186/s12974-018-1100-1</a>
Integrin mediated adhesion of osteoblasts to connective tissue growth factor (CTGF/CCN2) induces cytoskeleton reorganization and cell differentiation.
Animals; Mice; Signal Transduction; Cell Line; Cell Adhesion; *Cell Differentiation; Connective Tissue Growth Factor/chemistry/*metabolism; Core Binding Factor Alpha 1 Subunit/metabolism; Cytoskeleton/*metabolism; Extracellular Signal-Regulated MAP Kinases/metabolism; Focal Adhesion Protein-Tyrosine Kinases/metabolism; Integrins/*metabolism; Osteoblasts/*cytology/*metabolism; rac GTP-Binding Proteins/metabolism; Transcriptional Activation; Receptors; Vitronectin/metabolism
Pre-osteoblast adhesion and interaction with extracellular matrix (ECM) proteins through integrin receptors result in activation of signaling pathways regulating osteoblast differentiation. Connective tissue growth factor (CTGF/CCN2) is a matricellular protein secreted into the ECM. Prior studies in various cell types have shown that cell adhesion to CTGF via integrin receptors results in activation of specific signaling pathways that regulate cell functions, such as differentiation and cytoskeletal reorganization. To date, there are no studies that have examined whether CTGF can serve as an adhesive substrate for osteoblasts. In this study, we used the MC3T3-E1 cell line to demonstrate that CTGF serves as an adhesive matrix for osteoblasts. Anti-integrin blocking experiments and co-immunoprecipitation assays demonstrated that the integrin alphavbeta1 plays a key role in osteoblast adhesion to a CTGF matrix. Immunofluorescence staining of osteoblasts cultured on a CTGF matrix confirmed actin cytoskeletal reorganization, enhanced spreading, formation of focal adhesions, and activation of Rac1. Alkaline phosphatase (ALP) staining and activity assays, as well as Alizarin red staining demonstrated that osteoblast attachment to CTGF matrix enhanced maturation, bone nodule formation and matrix mineralization. To investigate whether the effect of CTGF on osteoblast differentiation involves integrin-mediated activation of specific signaling pathways, we performed Western blot, chromatin immunoprecipitation (ChIP) and qPCR assays. Osteoblasts cultured on a CTGF matrix showed increased total and phosphorylated (activated) forms of focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK). Inhibition of ERK blocked osteogenic differentiation in cells cultured on a CTGF matrix. There was an increase in runt-related transcription factor 2 (Runx2) binding to the osteocalcin gene promoter, and in the expression of osteogenic markers regulated by Runx2. Collectively, the results of this study are the first to demonstrate CTGF serves as a suitable matrix protein, enhancing osteoblast adhesion (via alphavbeta1 integrin) and promoting cell spreading via cytoskeletal reorganization and Rac1 activation. Furthermore, integrin-mediated activation of ERK signaling resulted in increased osteoblast differentiation accompanied by an increase in Runx2 binding to the osteocalcin promoter and in the expression of osteogenic markers.
Hendesi Honey; Barbe Mary F; Safadi Fayez F; Monroy M Alexandra; Popoff Steven N
PloS one
2015
2015
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1371/journal.pone.0115325" target="_blank" rel="noreferrer noopener">10.1371/journal.pone.0115325</a>
Parkinson's disease biomarker: a patent evaluation of WO2013153386.
Humans; Disease Progression; Biomarkers/metabolism; Phosphorylation; Mitochondria/pathology; mitophagy; autophagy; clinical testing; Dopaminergic Neurons/pathology; mitochondrial membrane potential; Parkinson Disease/*diagnosis/physiopathology; Patents as Topic; Protein Kinases/*metabolism; Ubiquitin-Protein Ligases/*metabolism
INTRODUCTION: Parkinson's disease (PD) is a neurodegenerative movement disorder resultant from the loss of dopaminergic neurons in the brain. There is an urgent need for effective biomarkers that can be used in the early diagnosis of PD. Mitochondrial dysfunction plays a significant role in PD pathology, which has led to the evaluation of mitophagy markers, PTEN-induced putative kinase 1 (PINK1), and PARKIN as possible biomarkers for the early diagnosis of PD. AREAS COVERED: The current patent describes the use of phosphorylation of PINK1 and PARKIN as a diagnostic measure. Specifically, Ser65 on PARKIN, which is phosphorylated by PINK1, and the autophosphorylation of PINK1 at Thr257 are described. EXPERT OPINION: This patent describes a much needed methodology that can easily be adapted in the clinical setting by which a biological sample, such as serum or cerebrospinal fluid, is collected and analyzed for the phosphorylation markers. Here, the phosphorylation activity seen in PINK1 and PARKIN can differentiate between age-matched controls and PD patients. This patent presents a novel diagnostic measure in early PD, as well as determines which medications would have a beneficial effect on a patient's disease progression.
Geldenhuys Werner J; Abdelmagid Samir M; Gallegos Patrick J; Safadi Fayez F
Expert opinion on therapeutic patents
2014
2014-08
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1517/13543776.2014.931375" target="_blank" rel="noreferrer noopener">10.1517/13543776.2014.931375</a>
The anabolic effects of vitamin D-binding protein-macrophage activating factor (DBP-MAF) and a novel small peptide on bone.
Female; Humans; Male; Time Factors; Animals; Rats; Radiography; Densitometry; Peptides/*chemistry; Anabolic Agents/pharmacology; Bone and Bones/*drug effects/*metabolism; Femur/metabolism/pathology; Glycopeptides/chemistry; Macrophage-Activating Factors/*pharmacology; Osteoporosis; Tibia/diagnostic imaging/metabolism; Vitamin D-Binding Protein/*pharmacology; Newborn
Vitamin D-binding protein-macrophage activating factor (DBP-MAF) has previously been shown to stimulate bone resorption and correct the skeletal defects associated with osteopetrosis in two nonallelic mutations in rats. This same protein and a small fragment of the protein have now been shown to demonstrate an anabolic effect on the skeleton of both newborn and young adult, intact rats. The novel peptide fragment was synthetically produced based on the human amino acid sequence at the site of glycosylation in the third domain of the native protein (DBP). The peptide tested is 14 amino acids in length and demonstrates no homologies other than to that region of DBP. Newborn rats were injected i.p. with saline, peptide (0.4 ng/g body wt.) or DBP-MAF (2 ng/g body wt.) every other day from birth to 14 days of age. On day 16 the rats were euthanized and the long bones collected for bone densitometry by pQCT. After 2 weeks of treatment with either the whole protein (DBP-MAF) or the small peptide, bone density was significantly increased in the treated animals compared to the saline controls. Young adult female rats (180 grams) were given s.c. injections of saline or peptide (0.4 ng/g body wt. or 5 ng/g body wt.) every other day for 2 weeks; 2 days after the final injections, the rats were euthanized and the femurs and tibias collected for bone densitometry. Both doses of the peptide resulted in significant increases in bone density as determined by pQCT. Young adult rats were injected locally with a single dose of the peptide (1 microg) or saline into the marrow cavity of the distal femur. One week after the single injection, the bones were collected for radiographic and histological evaluation. The saline controls showed no evidence of new bone formation, whereas the peptide-treated animals demonstrated osteoinduction in the marrow cavity and osteogenesis of surrounding cortical and metaphyseal bone. These data suggest that DBP-MAF and the synthetic peptide represent therapeutic opportunities for the treatment of a number of bone diseases and skeletal disorders. Systemic administration could be used to treat osteoporosis and a number of other osteopenias, and local administration could be effective in fractures, bony defect repairs, spinal surgery, and joint replacement.
Schneider Gary B; Grecco Kristina J; Safadi Fayez F; Popoff Steven N
Critical reviews in eukaryotic gene expression
2003
1905-06
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1615/critreveukaryotgeneexpr.v13.i24.190" target="_blank" rel="noreferrer noopener">10.1615/critreveukaryotgeneexpr.v13.i24.190</a>
Osteoactivin (GPNMB) ectodomain protein promotes growth and invasive behavior of human lung cancer cells.
Female; Humans; Animals; Mice; Apoptosis; GPNMB; *Cell Movement; Neoplasm Invasiveness; Membrane Glycoproteins/*metabolism; Biomarkers; *Cell Proliferation; cell adhesion; Cell Adhesion; integrin; lung cancer; Lung Neoplasms/metabolism/*pathology; NSCLC; Protein Domains; Xenograft Model Antitumor Assays; Carcinoma; Cultured; Tumor Cells; Nude; Non-Small-Cell Lung/metabolism/*pathology; Tumor/*metabolism
The potential application of GPNMB/OA as a therapeutic target for lung cancer will require a greater understanding of the impact of GPNMB/OA ectodomain (ECD) protein shedding into tumor tissues. Thus, in this work we characterized GPNMB/OA expression and extent of shedding of its ECD protein while evaluating the impact on lung cancer progression using three non-small cell lung cancer (NSCLC) cell lines: A549, SK-MES-1 and calu-6. We observed a direct correlation (R2 = 0.89) between GPNMB/OA expression on NSCLC cells and the extent of GPNMB/OA ECD protein shedding. Meanwhile, siRNA-mediated knockdown of GPNMB/OA in cancer cells significantly reduced GPNMB/OA ECD protein shedding, migration, invasion and adhesion to extracellular matrix materials. Also, exogenous treatment of cancer cells (expressing low GPNMB/OA) with recombinant GPNMB/OA protein (rOA) significantly facilitated cell invasion and migration, but the effects of rOA was negated by inclusion of a selective RGD peptide. Further studies in athymic (nu/nu) mice-bearing calu-6 showed that intratumoral supplementation with rOA effectively facilitated in vivo tumor growth as characterized by a high number of proliferating cells (Ki67 staining) coupled with a low number of apoptotic cells. Taken together, our results accentuate the relevance of GPNMB/OA ECD protein shedding to progression of lung cancer. Thus, strategies that suppress GPNMB/OA expression on lung cancer cells as well as negate shedding of GPNMB/OA ECD protein are worthy of consideration in lung cancer therapeutics.
Oyewumi Moses O; Manickavasagam Dharani; Novak Kimberly; Wehrung Daniel; Paulic Nikola; Moussa Fouad M; Sondag Gregory R; Safadi Fayez F
Oncotarget
2016
2016-03
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.18632/oncotarget.7323" target="_blank" rel="noreferrer noopener">10.18632/oncotarget.7323</a>
Identification of Novel Agents for the Treatment of Brain Metastases of Breast Cancer.
Female; Humans; Animals; Mice; Apoptosis; Cell Line; ADME; Antineoplastic Agents/*therapeutic use; brain cancer; Brain Neoplasms/*drug therapy/pathology/*secondary; Breast Neoplasms/*pathology; chemotherapy; CNS; distribution; drug discovery; Drug resistance; Tumor
BACKGROUND: Brain cancer from metastasized breast cancer has a high mortality rate in women. The treatment of lesions is hampered in large part by the blood-brain barrier (BBB), which prevents adequate distribution of anti-cancer compounds to brain metastases. METHOD: In this study we used a novel screening method to identify candidate molecules that are well-suited to utilizing the BBB choline transporter for distribution into the brain parenchyma. RESULTS: From our screen we identified two compounds, Ch-1 and Ch-2 that were able to reduce the brain tumor burden in a murine mouse model of brain metastasis of breast cancer. These compounds also significantly increased the survival of mice by more than 10 days. Mechanistic studies indicated that Ch-1 is able to prevent the activation of the pro-survival mitogen-activated kinases (MAPKs) by osteoactivin (OA; Glycoprotein nonmetastatic melanoma protein B GPNMB). CONCLUSION: The results from this study show that nutrient transporter virtual screening is a viable novel alternative to traditional drug screening programs to identify anti-cancer compounds for the treatment of brain cancers.
Venishetty Vinay K; Geldenhuys Werner J; Terell-Hall Tori B; Griffith Jessica I G; Sondag Gregory R; Safadi Fayez F; Lockman Paul R
Current cancer drug targets
2017
1905-7
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.2174/1568009617666161121123948" target="_blank" rel="noreferrer noopener">10.2174/1568009617666161121123948</a>
TRAPPC9: Novel insights into its trafficking and signaling pathways in health and disease (Review).
Trafficking protein particle complex 9 (TRAPPC9) is a protein subunit of the transport protein particle II (TRAPPII), which has been reported to be important in the trafficking of cargo from the endoplasmic reticulum (ER) to the Golgi, and in intraGolgi and endosometoGolgi transport in yeast cells. In mammalian cells, TRAPPII has been shown to be important in Golgi vesicle tethering and intraGolgi transport. TRAPPC9 is considered to be a novel molecule capable of modulating the activation of nuclear factorkappaB (NFkappaB). Mutations in TRAPPC9 have been linked to a rare consanguineous hereditary form of mental retardation, as part of the NFkappaB pathways. In addition, TRAPPC9 has been reported to be involved in breast and colon cancer and liver diseases. The present review highlights the most recent publications on the structure, expression and function of TRAPPC9, and its association with various human diseases.
Mbimba Thomas; Hussein Nazar J; Najeed Ayesha; Safadi Fayez F
International journal of molecular medicine
2018
2018-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.3892/ijmm.2018.3889" target="_blank" rel="noreferrer noopener">10.3892/ijmm.2018.3889</a>
Autophagy plays an essential role in bone homeostasis.
osteoclast; autophagosome; autophagy; osteoblast; osteocytes
Autophagy is very critical for multiple cellular processes. Autophagy plays a critical role in bone cell differentiation and function.
Jaber Fatima A; Khan Nazir M; Ansari Mohammad Y; Al-Adlaan Asaad A; Hussein Nazar J; Safadi Fayez F
Journal of cellular physiology
2019
2019-02
<a href="http://doi.org/10.1002/jcp.27071" target="_blank" rel="noreferrer noopener">10.1002/jcp.27071</a>
The glycoprotein GPNMB attenuates astrocyte inflammatory responses through the CD44 receptor.
Female; Humans; Male; Animals; Mice; Reactive Oxygen Species/metabolism; Astrocyte; CD44; GPNMB; *Neuroinflammation; *Parkinson's disease; Case-Control Studies; Analysis of Variance; Signal Transduction/drug effects; Hyaluronan Receptors/*metabolism; Glial Fibrillary Acidic Protein/metabolism; Nitric Oxide/metabolism; Cells; Cultured; RNA; Messenger/metabolism; Chemical; 3; Databases; 1-Methyl-4-phenyl-1; 2; 6-tetrahydropyridine/pharmacology; Anti-Inflammatory Agents/*therapeutic use; Astrocytes/*drug effects; Cytokines/genetics/metabolism; Inflammation/*drug therapy/etiology; Membrane Glycoproteins/*therapeutic use; Neurotoxins/toxicity; Parkinson Disease/complications/*pathology
BACKGROUND: Neuroinflammation is one of the hallmarks of neurodegenerative diseases, such as Parkinson's disease (PD). Activation of glial cells, including microglia and astrocytes, is a characteristic of the inflammatory response. Glycoprotein non-metastatic melanoma protein B (GPNMB) is a transmembrane glycoprotein that releases a soluble signaling peptide when cleaved by ADAM10 or other extracellular proteases. GPNMB has demonstrated a neuroprotective role in animal models of ALS and ischemia. However, the mechanism of this protection has not been well established. CD44 is a receptor expressed on astrocytes that can bind GPNMB, and CD44 activation has been demonstrated to reduce NFkappaB activation and subsequent inflammatory responses in macrophages. GPNMB signaling has not been investigated in models of PD or specifically in astrocytes. More recently, genetic studies have linked polymorphisms in GPNMB with risk for PD. Therefore, it is important to understand the role this signaling protein plays in PD. METHODS: We used data mining techniques to evaluate mRNA expression of GPNMB and its receptor CD44 in the substantia nigra of PD and control brains. Immunofluorescence and qPCR techniques were used to assess GPNMB and CD44 levels in mice treated with MPTP. In vitro experiments utilized the immortalized mouse astrocyte cell line IMA2.1 and purified primary mouse astrocytes. The effects of recombinant GPNMB on cytokine-induced astrocyte activation was determined by qPCR, immunofluorescence, and measurement of nitric oxide and reactive oxygen production. RESULTS: Increased GPNMB and CD44 expression was observed in the substantia nigra of human PD brains and in GFAP-positive astrocytes in an animal model of PD. GPNMB treatment attenuated cytokine-induced levels of inducible nitric oxide synthase, nitric oxide, reactive oxygen species, and the inflammatory cytokine IL-6 in an astrocyte cell line and primary mouse astrocytes. Using primary mouse astrocytes from CD44 knockout mice, we found that the anti-inflammatory effects of GPNMB are CD44-mediated. CONCLUSIONS: These results demonstrate that GPNMB may exert its neuroprotective effect through reducing astrocyte-mediated neuroinflammation in a CD44-dependent manner, providing novel mechanistic insight into the neuroprotective properties of GPNMB.
Neal Matthew L; Boyle Alexa M; Budge Kevin M; Safadi Fayez F; Richardson Jason R
Journal of neuroinflammation
2018
2018-03
<a href="http://doi.org/10.1186/s12974-018-1100-1" target="_blank" rel="noreferrer noopener">10.1186/s12974-018-1100-1</a>
TRAPPC9: Novel insights into its trafficking and signaling pathways in health and disease (Review).
Humans; Animals; Protein Binding; Gene Expression Regulation; Structure-Activity Relationship; Protein Transport; *Signal Transduction; *Disease Susceptibility; Carrier Proteins/chemistry/genetics/*metabolism; Protein Interaction Domains and Motifs
Trafficking protein particle complex 9 (TRAPPC9) is a protein subunit of the transport protein particle II (TRAPPII), which has been reported to be important in the trafficking of cargo from the endoplasmic reticulum (ER) to the Golgi, and in intraGolgi and endosometoGolgi transport in yeast cells. In mammalian cells, TRAPPII has been shown to be important in Golgi vesicle tethering and intraGolgi transport. TRAPPC9 is considered to be a novel molecule capable of modulating the activation of nuclear factorkappaB (NFkappaB). Mutations in TRAPPC9 have been linked to a rare consanguineous hereditary form of mental retardation, as part of the NFkappaB pathways. In addition, TRAPPC9 has been reported to be involved in breast and colon cancer and liver diseases. The present review highlights the most recent publications on the structure, expression and function of TRAPPC9, and its association with various human diseases.
Mbimba Thomas; Hussein Nazar J; Najeed Ayesha; Safadi Fayez F
International journal of molecular medicine
2018
2018-12
<a href="http://doi.org/10.3892/ijmm.2018.3889" target="_blank" rel="noreferrer noopener">10.3892/ijmm.2018.3889</a>
A novel regulatory role of TRAPPC9 in L-plastin-mediated osteoclast actin ring formation
actin ring; cytoskeleton; L-plastin; osteoclast; protein trafficking; TRAPPC9; TRAPPII
Trafficking protein particle complex 9 (TRAPPC9) is a major subunit of the TRAPPII complex. TRAPPC9 has been reported to bind nuclear factor κB kinase subunit β (IKKβ) and NF-kB-inducing kinase (NIK) where it plays a role in the canonical and noncanonical of nuclear factor-κB (NF-kB) signaling pathways, receptively. The role of TRAPPC9 in protein trafficking and cytoskeleton organization in osteoclast (OC) has not been studied yet. In this study, we examined the mRNA expression of TRAPPC9 during OC differentiation. Next, we examined the colocalization of TRAPPC9 with cathepsin-K, known to mediate OC resorption suggesting that TRAPPC9 mediates the trafficking pathway within OC. To identify TRAPPC9 protein partners important for OC-mediated cytoskeleton re-organization, we conducted immunoprecipitation of TRAPPC9 in mature OCs followed by mass spectrometry analysis. Our data showed that TRAPPC9 binds various protein partners. One protein with high recovery rate is L-plastin (LPL). LPL localizes at the podosomes and reported to play a crucial role in actin aggregation thereby actin ring formation and OC function. Although the role of LPL in OC-mediated bone resorption has not fully reported in detail. Here, first, we confirmed the binding of LPL to TRAPPC9 and, then, we investigated the potential regulatory role of TRAPPC9 in LPL-mediated OC cytoskeleton reorganization. We assessed the localization of TRAPPC9 and LPL in OC and found that TRAPPC9 is colocalized with LPL at the periphery of OC. Next, we determined the effect of TRAPPC9 overexpression on LPL recruitment to the actin ring using a viral system. Interestingly, our data showed that TRAPPC9 overexpression promotes the recruitment of LPL to the actin ring when compared with control cultures. In addition, we observed that TRAPPC9 overexpression reorganizes actin clusters/aggregates and regulates vinculin recruitment into the OC periphery to initiate podosome formation.
Hussein Nazar J; Mbimba Thomas; Al-Adlaan Asaad A; Ansari Mohammad Y; Jaber Fatima A; McDermott Scott; Kasumov Takhar; Safadi Fayez F
Journal of Cellular Biochemistry
2019
2019-08
<a href="http://doi.org/10.1002/jcb.29168" target="_blank" rel="noreferrer noopener">10.1002/jcb.29168</a>
Bone mineral density in adolescent urinary stone formers: is sex important?
Bone; children; disease; fracture; health; inflammation; kidney-stones; nephrolithiasis; osteoporosis; Pediatrics; risk; Sex; Urolithiasis; Urolithiasis
Urinary stone disease (USD) is affecting a greater number of children and low bone mineral density (BMD) and increased skeletal fractures have been demonstrated in stone patients; however, the mechanism(s) driving bone disease remain unclear. This pilot study was undertaken to assess an adolescent kidney stone cohort's BMD and evaluate for an inverse correlation between BMD and urine concentration of lithogenic minerals and/or inflammatory levels. Prospective case-control study was carried out at a large pediatric center. 15 participants with USD (12-18 years of age, 8 female) were matched by age, sex, and body mass index to 15 controls. Lumbar and total body BMD z-score did not differ between groups. When stone formers were separated by sex, there was a significant difference between male stone formers vs. controls total body BMD z-score (Fig. 1). BMD z-score did not significantly correlate with urine calcium, oxalate, citrate or magnesium. Higher urine IL-13 did significantly correlate with higher total body BMD z-score (r = 0.677, p = 0.018). Total body BMD z-score did significantly correlate with body mass index (BMI) as expected for the control group (r = 0.6321, p = 0.0133). However, this relationship was not present in the USD group (r = - 0.1629, p = 0.5619). This is a small but hypothesis-generating study which demonstrates novel evidence of male-specific low BMD in adolescent stone formers. Furthermore, we demonstrated a positive association between urine
Kusumi Kirsten; Schwaderer Andrew L; Clark Curtis; Budge Kevin; Hussein Nazar; Raina Rupesh; Denburg Michelle; Safadi Fayez F
Urolithiasis
2020
2020-03-31
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
journalArticle
<a href="http://doi.org/10.1007/s00240-020-01183-w" target="_blank" rel="noreferrer noopener">10.1007/s00240-020-01183-w</a>
Transgenic Overexpression of GPNMB Protects Against MPTP-Induced Neurodegeneration.
GPNMB; Microglia; MPTP; Neuroinflammation; Neuroprotective; Parkinson's disease
Parkinson's disease (PD) is a progressive neurodegenerative disease highlighted by a marked loss of dopaminergic cell loss and motor disturbances. Currently, there are no drugs that slow the progression of the disease. A myriad of factors have been implicated in the pathogenesis and progression of PD including neuroinflammation. Although anti-inflammatory agents are being evaluated as potential disease-modifying therapies for PD, none has proven effective to date, suggesting that new and novel targets are needed. Glycoprotein nonmetastatic melanoma protein B (GPNMB) is a transmembrane glycoprotein that has recently been shown to reduce inflammation in astrocytes and to be increased in post-mortem PD brain samples. Here we show that transgenic overexpression of GPNMB protects against dopaminergic neurodegeneration in a
Budge Kevin; Neal Matthew L; Richardson Jason R; Safadi Fayez F
Molecular neurobiology
2020
2020-05-20
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
journalArticle
<a href="http://doi.org/10.1007/s12035-020-01921-6" target="_blank" rel="noreferrer noopener">10.1007/s12035-020-01921-6</a>