The Experts below are selected from a list of 5706 Experts worldwide ranked by ideXlab platform
Stephanie Filleur - One of the best experts on this subject based on the ideXlab platform.
-
PEDF increases the tumoricidal activity of macrophages towards prostate cancer cells in vitro.
PloS one, 2017Co-Authors: Dalia Martinez-marin, Courtney Jarvis, Thomas Nelius, Werner De Riese, Olga V. Volpert, Stephanie FilleurAbstract:Background Although inflammation and prostate cancer (PCa) have been linked, the molecular interactions between macrophages and PCa cells are poorly explored. Pigment Epithelium-Derived Factor (PEDF) is an anti-angiogenic and anti-tumor factor. We previously showed that PEDF induces macrophages recruitment in vitro, correlates with macrophages density in human prostate, and stimulates macrophages polarization towards the classically activated pathway. Here, we demonstrate that PEDF modulates the interaction between macrophages and PCa cells through a bidirectional signalling leading to tumor cell apoptosis and phagocytosis. Methods RAW 264.7 and THP-1 cells, and BMDMs were grown in vitro as mono- or co-cultures with PC3 or CL1 tumor cells. The effects of PEDF and its derived P18 peptide were measured on macrophages differentiation, migration, and superoxide production, and tumor cell apoptosis and phagocytosis. PEDF receptors (ATP5B, PNPLA2, and LRP6) and CD47 mRNA and protein expression were quantified in macrophages and tumor cells by quantitative RT-PCR, western blot, immunofluorescence and flow cytometry. Results We found that PEDF induced the migration of macrophages towards tumor 3D spheroids and 2D cultures. In co-culture, PEDF increased PCa cells phagocytosis through an indirect apoptosis-dependent mechanism. Moreover, PEDF stimulated the production of superoxide by macrophages. Conditioned media from macrophages exposed to PEDF induced tumor cells apoptosis in contrast to control conditioned media suggesting that ROS may be involved in tumor cells apoptosis. ATP5B and PNPLA2 PEDF receptors on macrophages and CD47 on tumor cells were respectively up- and down-regulated by PEDF. As PEDF, blocking CD47 induced phagocytosis. Inhibiting ATP5B reduced phagocytosis. Inversely, PNPLA2 inhibition blocks differentiation but maintains phagocytosis. CD47-induced phagocytosis was partially reverted by ATP5B inhibition suggesting a complementary action. Similar effects were observed with P18 PEDF-derived peptide. Conclusions These data established that modulating the molecular interactions between macrophages and PCa cells using PEDF may be a promising strategy for PCa treatment.
-
Abstract 3359: PEDF modulatory action on macrophages: A new way to curb prostate cancer development
Tumor Biology, 2015Co-Authors: Dalia Martinez-marin, Thomas Nelius, Olga V. Volpert, Stephanie FilleurAbstract:Macrophages have been described as one of the main inflammatory components involved in prostate cancer (PCa) initiation, progression, and metastasis. PEDF (Pigment Epithelium-Derived Factor) is an anti-angiogenic factor with differentiation activities and was recently suggested as an immune-modulating factor. PEDF expression has been shown to be down-regulated in PCa compared to normal tissues. In previous studies we have demonstrated that PEDF re-expression in PCa cells curbs tumor growth in vivo and significantly prolongs the survival of tumor-bearing mice. Others have shown that PEDF expression increased the recruitment of tumor-cytotoxic macrophages into orthotopic MatLyLu rat prostate tumors suggesting a link between PEDF and inflammation in PCa. While PEDF9s role in inflammation has been suggested, the precise modes of action of PEDF on macrophages still remain unknown and necessitate further investigation. Our preliminary data have showed that PEDF stimulates the migration of monocytes/macrophages using in vitro chemotaxis boyden chamber assay and towards tumor 3D spheroids. We showed that PEDF expression levels positively correlate with macrophage density in human prostate. In both cell lines and prostate specimens, we have demonstrated that PEDF directly induces the polarization of macrophages and bone marrow derived macrophages (BMDMs) towards a M1/tumor-cytotoxic pathway. As a result of their differentiation, we have found that PEDF stimulates the phagocytosis of tumor cells, which suggest another mechanism by which PCa growth is halted. We are currently investigating the molecular mechanisms by which PEDF induces migration, differentiation and phagocytic activity in macrophages. PEDF mechanisms are being investigated by expression levels of PEDF receptors (ATP5B, PNPLA2, LRP6) in macrophage cell lines and BMDMs. So far we have been identified ATP5B and PNPLA2 as the two main receptors expressed in both cell types. While all three receptors in cell lines increased, only ATP5B and PNPLA2 receptors increased in BMDMs in response to PEDF. To map the functional region involved in PEDF9s inflammatory action, we are investigating the PEDF-derivative synthetic 18-mer peptide (residues 39-57). P18 has been shown to block endothelial cell chemotaxis and induces apoptosis in vitro, and to be more effective than its parental 34-mer peptide (residues 24-57) in blocking growth and angiogenesis in PCa. We were able to demonstrate that macrophages treated with P18 in comparison to PEDF, show a higher efficacy for macrophages differentiation. Using confocal microscopy we demonstrated a larger rate of phagocytosis of PCa cells by macrophages than compared to PEDF. The results of our study are of importance as they suggest that macrophages may play a key role in PEDF anti-tumor effects. A better understanding of PEDF may lead to further development of PEDF-based anticancer therapy or improvement of alternatives to chemotherapy for PCa. Citation Format: Dalia Martinez-Marin, Thomas Nelius, Olga Volpert, Stephanie Filleur. PEDF modulatory action on macrophages: A new way to curb prostate cancer development. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3359. doi:10.1158/1538-7445.AM2015-3359
-
Positive correlation between PEDF expression levels and macrophage density in the human prostate.
Prostate, 2013Co-Authors: Thomas Nelius, Dalia Martinez-marin, Werner De Riese, Christina A. Samathanam, Natalie Gaines, Jessica Stevens, Johnny Hickson, Stephanie FilleurAbstract:BACKGROUND: In this study, we investigated the capacity of pigment epithelium-derived factor (PEDF) to modulate the recruitment and the differentiation of monocytes/macrophages both in vitro and in human prostate. METHODS: Using Boyden chambers, we assessed PEDF effect on the migration of monocytes and chemically activated RAW 264.7 macrophages. Normal, prostatitis, and prostate cancer specimens were retrospectively selected and examined by immunohistochemistry for PEDF expression and infiltration of immune CD68 + macrophagic cells. PEDF expression and macrophage density were then correlated with each other and clinicopathological parameters. M1 and M2 differentiation markers were quantified by qRT-PCR, Western blotting, and ELISA. RESULTS: In chemotaxis, PEDF induced the migration of monocytes/macrophages. In immunohistochemistry, macrophages were markedly increased in prostatitis and malignant compared to normal tissues. PEDF was expressed at variable levels in the stroma and epithelium. PEDF mRNA was down-regulated in both prostate cancer and prostatitis compared to normal tissues. In correlation studies, macrophage density and PEDF expression were respectively positively and negatively associated with prostate size. Most importantly, PEDF expression positively correlated with macrophage density. Finally, PEDF stimulated the expression of iNOS, IL12, and TNFα; and inhibited IL10 and arginase 1 in mouse and human macrophages confirming a M1-type differentiation. CONCLUSIONS: Our data demonstrate that PEDF acts directly on monocytes/macrophages by inducing their migration and differentiation into M1-type cells. These findings suggest a possible role of macrophages in PEDF anti-tumor properties and may support further development of PEDF-based anti-cancer therapy.
-
Effect of PEDF on the in vivo antitumor activities of low-dose chemotherapy in CRPC.
Journal of Clinical Oncology, 2013Co-Authors: Thomas Nelius, Jennifer Hirsch, Everardo Cobos, Stephanie FilleurAbstract:173 Background: The development of metronomic/low dose administration of conventional chemotherapeutic drugs has shown great promise in the treatment of castration-refractory prostate cancer (CPRC). Pigment Epithelium-Derived Factor (PEDF) is a natural angio-inhibitor which is down-regulated in prostate cancer. We have previously demonstrated that the over-expression of PEDF in human CRPC PC3 cells decreased tumor growth in vivo. In the present study, we further validated PEDF anti-tumor properties in the highly metastatic CRPC LNCaP-derivative CL1 cells. We also hypothesized that PEDF may enhance the cytotoxicity effects of low dose docetaxel (DTX) and cyclophosphamide (CTX) chemotherapies in vivo. Methods: PC3 and CL1 cell lines were genetically modified to stably express the fluorescent DsRed Express protein with PEDF. Resulting cells were characterized in vitro for PEDF expression by western blot and, for proliferation by growth curves and clone formation in matrigel. PEDF anti-tumor effects were asse...
-
Positive correlation between PEDF expression levels and macrophage density in the human prostate
The Prostate, 2012Co-Authors: Thomas Nelius, Dalia Martinez-marin, Werner De Riese, Christina A. Samathanam, Natalie Gaines, Jessica Stevens, Johnny Hickson, Stephanie FilleurAbstract:BACKGROUND In this study, we investigated the capacity of pigment epithelium-derived factor (PEDF) to modulate the recruitment and the differentiation of monocytes/macrophages both in vitro and in human prostate. METHODS Using Boyden chambers, we assessed PEDF effect on the migration of monocytes and chemically activated RAW 264.7 macrophages. Normal, prostatitis, and prostate cancer specimens were retrospectively selected and examined by immunohistochemistry for PEDF expression and infiltration of immune CD68 + macrophagic cells. PEDF expression and macrophage density were then correlated with each other and clinicopathological parameters. M1 and M2 differentiation markers were quantified by qRT-PCR, Western blotting, and ELISA. RESULTS In chemotaxis, PEDF induced the migration of monocytes/macrophages. In immunohistochemistry, macrophages were markedly increased in prostatitis and malignant compared to normal tissues. PEDF was expressed at variable levels in the stroma and epithelium. PEDF mRNA was down-regulated in both prostate cancer and prostatitis compared to normal tissues. In correlation studies, macrophage density and PEDF expression were respectively positively and negatively associated with prostate size. Most importantly, PEDF expression positively correlated with macrophage density. Finally, PEDF stimulated the expression of iNOS, IL12, and TNFα; and inhibited IL10 and arginase 1 in mouse and human macrophages confirming a M1-type differentiation. CONCLUSIONS Our data demonstrate that PEDF acts directly on monocytes/macrophages by inducing their migration and differentiation into M1-type cells. These findings suggest a possible role of macrophages in PEDF anti-tumor properties and may support further development of PEDF-based anti-cancer therapy. Prostate 73: 549–561, 2013. © 2012 Wiley Periodicals, Inc.
S Patricia Becerra - One of the best experts on this subject based on the ideXlab platform.
-
PEDF and Derived Peptides Prevent Apoptosis and Promote Differentiation of Retinal Photoreceptors
2021Co-Authors: Germán Michelis, Olga Lorena German, Rafael Villasmil, Nora P. Rotstein, Luis E. Politi, S Patricia BecerraAbstract:Pigment epithelium-derived factor (PEDF) is a cytoprotective protein for the retina. We hypothesize that this protein acts on neuronal survival and differentiation of photoreceptor cells in culture. The purpose of the present study was to evaluate the neurotrophic effects of PEDF and its fragments in an in vitro model of cultured primary retinal neurons that die spontaneously in the absence of trophic factors. Results show that PEDF protected photoreceptor precursors from apoptosis, preserved mitochondrial function and promoted polarization of opsin enhancing their developmental process, as well as induced neurite outgrowth in amacrine neurons. These effects were abolished by an inhibitor of the PEDF receptor or receptor-derived peptides that block ligand/receptor interactions. While all the activities were specifically conferred by short peptide fragments (17 amino acid residues) derived from the PEDF neurotrophic domain, no effects were triggered by peptides from the PEDF antiangiogenic region. The observed effects on retinal neurons imply a specific activation of the PEDF receptor by a small neurotrophic region of PEDF. Our findings support the neurotrophic PEDF peptides as neuronal guardians for the retina, highlighting their potential as promoters of retinal differentiation, and inhibitors of retina cell death and its blinding consequences.
-
PEDF peptides promote photoreceptor survival in rd10 retina models.
Experimental eye research, 2019Co-Authors: Alberto M. Hernández-pinto, Preeti Subramanian, Federica Polato, Andrés De La Rocha-muñoz, Susan Vitale, Enrique J. De La Rosa, S Patricia BecerraAbstract:The purpose of the study is to evaluate the protective properties of PEDF peptide fragments on rd10 mouse models of retinal degeneration ex vivo. Human recombinant PEDF and synthetic peptides were used. Rd10 retinal explants as well as wild-type retinal explants treated with zaprinast to mimic the rd10 photoreceptor cell death were employed. PEDF protein was intravitreally administered into rd10 mice. Outer nuclear layer thickness measurements in retinal sections, TUNEL labeling in retinal explants, western blots and immunofluorescence with retinal samples were performed. PEDF protein levels in the RPE of rd10 mice decreased with age (P15 - P25). Levels of PEDF receptor PEDF-R declined in the photoreceptor inner segments from rd10 relative to wild-type mice at P25. PEDF administration increased the outer nuclear layer thickness of rd10 retinas in vivo and decreased the number of TUNEL+ nuclei of photoreceptors in rd10 retinal explant cultures, both relative to untreated controls. Peptides containing the PEDF neurotrophic region decreased the number of TUNEL+ photoreceptors in both rd10 and zaprinast-induced cell death ex vivo models, while peptides without the neurotrophic region and/or lacking affinity for PEDF-R were ineffective in protecting photoreceptors. Thus, retinal explants are a valuable system to evaluate PEDF activity. Short peptides with the photoreceptor-protective property of PEDF may prove useful for the development of therapeutic agents for photoreceptor protection in retinal degenerations.
-
Pigment epithelium-derived factor hinders photoreceptor cell death by reducing intracellular calcium in the degenerating retina.
Cell death & disease, 2018Co-Authors: Antonella Comitato, Preeti Subramanian, S Patricia Becerra, Giandomenico Turchiano, Monica Montanari, Valeria MarigoAbstract:Calcium ions play a critical role in neuronal cell death. Pigment epithelium-derived factor (PEDF) is a promising neuroprotective protein for photoreceptor cells but the mechanisms mediating its effects against retinal degeneration are still not well characterized. We addressed this question in the rd1 degenerating mouse retina that bears a mutation in the Pde6b gene encoding one subunit of the phosphodiesterase enzyme. Loss of phosphodiesterase activity in rod photoreceptor cells increases cyclic guanosine monophosphate (cGMP) levels leading to a rise in intracellular calcium. Short-term treatments with recombinant human PEDF protein decreased intracellular calcium in photoreceptors in vivo. Taking advantage of calcium pump blockers, we defined that PEDF signaling acts on PMCA calcium pumps to lower intracellular calcium. PEDF restrained cell death pathways activated by high calcium levels and engaging calpains, BAX and AIF. The neurotrophic effects were mediated by the PEDF receptor (PEDF-R), encoded by the PNPLA2 gene. Finally, peptides containing the neurotrophic domain of PEDF targeted these same cell death pathways in vivo. The findings reveal rescue from death of degenerating photoreceptor cells by a PEDF-mediated preservation of intracellular calcium homeostasis.
-
PEDF in the Retina
The Serpin Family, 2015Co-Authors: Jeanee Bullock, S Patricia BecerraAbstract:Pigment epithelium-derived factor (PEDF) is a protective protein of the eye, with neurotrophic and anti-angiogenic activities. It was discovered as a secreted factor from retinal pigment epithelium. The interphotoreceptor matrix and vitreous humor contain soluble and diffusible PEDF protein, which interacts with glycosaminoglycans, collagen, and cell-surface receptors to act on retina cells. Sequence alignment reveals that PEDF is a member of the serpin superfamily. PEDF shares hallmark features of serpins including the conserved tertiary structure with an exposed peptide loop towards its C-end. However, it is classified as a noninhibitory serpin. This review will summarize studies on the role of PEDF in the retina, in particular its anti-angiogenic, antiapoptotic, and anti-inflammatory properties. Studies with established animal models for retina diseases have demonstrated the importance of PEDF in the eye. In addition, PEDF is considered an important marker for retinal pigment epithelium derived from stem cells. The therapeutic potential of PEDF will be emphasized.
-
The effects of PEDF on cancer biology: mechanisms of action and therapeutic potential
Nature reviews. Cancer, 2013Co-Authors: S Patricia Becerra, Vicente NotarioAbstract:The potent actions of pigment epithelium-derived factor (PEDF) on tumour-associated cells, and its extracellular localization and secretion, stimulated research on this multifunctional serpin. Such studies have identified several PEDF receptors and downstream signalling pathways. Known cellular PEDF responses have expanded from the initial discovery that PEDF induces retinoblastoma cell differentiation to its anti-angiogenic, antitumorigenic and antimetastatic properties. Although the diversity of PEDF activities seems to be complex, they are consistent with the varied mechanisms that regulate this multimodal factor. If PEDF is to be used for cancer management, a deeper appreciation of its many functions and mechanisms of action is needed.
Zhongming Zhang - One of the best experts on this subject based on the ideXlab platform.
-
PEDF protects cardiomyocytes by promoting FUNDC1‑mediated mitophagy via PEDF-R under hypoxic condition.
International journal of molecular medicine, 2018Co-Authors: Zhiwei Liu, Zhu Wang, Hao Zhang, Hongyan Dong, Xiaoyu Wang, Qixiang Zhao, Yiqian Zhang, Zhongming ZhangAbstract:Pigment epithelial-derived factor (PEDF) is known to exert diverse physiological activities. Previous studies suggest that hypoxia could induce mitophagy. Astoundingly, under hypoxic condition, we found that PEDF decreased the mitochondrial density of cardiomyocytes. In this study, we evaluated whether PEDF could decrease the mitochondrial density and play a protective role in hypoxic cardiomyocytes via promoting mitophagy. Immunostaining and western blotting were used to analyze mitochondrial density and mitophagy of hypoxic cardiomyocytes. Gas chromatography‑mass spectrometry and ELISA were used to analyze levels of palmitic acid and diacylglycerol. Transmission Electron Microscopy was used to detect mitophagy and the mitochondrial density in adult male Sprague-Dawley rat model of acute myocardial infarction. Compared to the control group, we observed that PEDF decreased mitochondrial density through promoting hypoxic cardiomyocyte mitophagy. PEDF increased the levels of palmitic acid and diacylglycerol, and then upregulated the levels of protein kinase Cα (PKC-α) and its activation. Furthermore, inhibition of PKC-α by Go6976 could effectively suppress PEDF-induced mitophagy. Besides, we found that PEDF promoted FUNDC1-mediated cardiomyocyte mitophagy via ULK1, which depended on the activation of PKC-α. Finally, we discovered that mitophagy was increased and mitochondrial density was reduced in adult male Sprague-Dawley rat model of acute myocardial infarction. We concluded that PEDF promotes mitophagy to protect hypoxic cardiomyocytes, through PEDF/PEDF-R/PA/DAG/PKC-α/ULK1/FUNDC1 pathway.
-
PEDF Inhibits the Activation of NLRP3 Inflammasome in Hypoxia Cardiomyocytes through PEDF Receptor/Phospholipase A2
International journal of molecular sciences, 2016Co-Authors: Zhongxin Zhou, Zhu Wang, Qiuhua Guan, Fan Qiu, Zhiwei Liu, Hao Zhang, Hongyan Dong, Zhongming ZhangAbstract:The nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome has been linked to sterile inflammation, which is involved in ischemic injury in myocardial cells. Pigment epithelium-derived factor (PEDF) is a multifunctional secreted glycoprotein with many biological activities, such as anti-inflammatory, antioxidant and anti-angiogenic properties. However, it is not known whether and how PEDF acts to regulate the activation of the NLRP3 inflammasome in cardiomyocytes. In the present study, we used the neonatal cardiomyocytes models of ischemia-like conditions to evaluate the mitochondrial fission and the activation of the NLRP3 inflammasome. We also determined the mechanism by which PEDF inhibits hypoxia-induced activation of the NLRP3 inflammasome. We found that PEDF decreased the activation of the NLRP3 inflammasome in neonatal cardiomyocytes through pigment epithelial-derived factor receptor/calcium-independent phospholipase A2 (PEDFR/iPLA2). Meanwhile, PEDF reduced Drp1-induced mitochondrial fission and mitochondrial fission-induced mitochondrial DNA (mtDNA), as well as mitochondrial reactive oxygen species (mtROS) release into cytosol through PEDFR/iPLA2. We also found that PEDF inhibited mitochondrial fission-induced NLRP3 inflammasome activation. Furthermore, previous research has found that endogenous cytosolic mtDNA and mtROS can serve as activators of NLRP3 inflammasome activity. Therefore, we hypothesized that PEDF can protect against hypoxia-induced activation of the NLRP3 inflammasome by inhibiting mitochondrial fission though PEDFR/iPLA2.
-
Pigment Epithelium-Derived Factor (PEDF) Improves Ischemic Cardiac Functional Reserve Through Decreasing Hypoxic Cardiomyocyte Contractility Through PEDF Receptor (PEDF-R).
Journal of the American Heart Association, 2016Co-Authors: Yiqian Zhang, Zhiwei Liu, Hao Zhang, Hongyan Dong, Xiaoyu Wang, Zhongming ZhangAbstract:Background Pigment epithelium‐derived factor (PEDF), which belongs to the noninhibitory serpin family, has shown the ability to stimulate several physiological processes, such as antiangiogenesis, anti‐inflammation, and antioxidation. In the present study, the effects of PEDF on contractility and calcium handling of rat ventricular myocytes were investigated. Methods and Results Adult Sprague‐Dawley rat models of acute myocardial infarction (AMI) were surgically established. PEDF‐lentivirus was delivered into the myocardium along and away from the infarction border to overexpress PEDF. Video edge detection was used to measure myocyte shortening in vitro. Intracellular Ca2+ was measured in cells loaded with the Ca2+ sensitive fluorescent indicator, Fura‐2‐acetoxymethyl ester. PEDF local overexpression enhanced cardiac functional reserve in AMI rats and reduced myocardial contracture bordering the infracted area. Exogenous PEDF treatment (10 nmol/L) caused a significant decrease in amplitudes of isoproterenol‐stimulated myocyte shortening, Ca2+ transients, and caffeine‐evoked Ca2+ transients in vitro. We then tested a potential role for PEDF receptor‐mediated effects on upregulation of protein kinase C (PKC) and found evidence of signaling through the diacylglycerol/PKCα pathway. We also confirmed that pretreatment of cardiomyocytes with PEDF exhibited dephosphorylation of phospholamban at Ser16, which could be attenuated with PKC inhibition. Conclusions The results suggest that PEDF depresses myocyte contractility by suppressing phosphorylation of phospholamban and Ca2+ transients in a PKCα‐dependent manner through its receptor, PEDF receptor, therefore improving cardiac functional reserve during AMI.
-
PEDF and PEDF derived peptide 44mer inhibit oxygen glucose deprivation induced oxidative stress through upregulating pparγ via PEDF r in h9c2 cells
Biochemical and Biophysical Research Communications, 2016Co-Authors: Wei Zhuang, Qiuhua Guan, Zhiwei Liu, Hao Zhang, Hongyan Dong, Jiajun Pan, Tengteng Wei, Huazhu Cui, Zhongming ZhangAbstract:Pigment epithelial-derived factor (PEDF) is a glycoprotein with broad biological activities including inhibiting oxygen-glucose deprivation(OGD)-induced cardiomyocytes apoptosis through its anti-oxidative properties. PEDF derived peptide-44mer shows similar cytoprotective effect to PEDF. However, the molecular mechanisms mediating cardiomyocytes apoptosis have not been fully established. Here we found that PEDF and 44mer decreased the content of ROS. This content was abolished by either PEDF-R small interfering RNA (siRNA) or PPARγ antagonist. The level of Lysophosphatidic acid (LPA) and phospholipase A2 (PLA2) was observed as drawn from the ELISA assays. PEDF and 44mer sequentially induced PPARγ expression was observed both in qPCR and Western blot assays. The level of LPA and PLA2 and PPARγ expression increased by PEDF and 44mer was significantly attenuated by PEDF-R siRNA. However, PEDF and 44mer inhibited the H9c2 cells and cultured neonatal rat myocardial cells apoptosis rate. On the other hand, TUNEL assay and cleavage of procaspase-3 showed that PEDF-R siRNA or PPARγ antagonist increased the apoptosis again. We conclude that under OGD condition, PEDF and 44mer reduce H9c2 cells apoptosis and inhibit OGD-induced oxidative stress via its receptor PEDF-R and the PPARγ signaling pathway.
-
PEDF and PEDF-derived peptide 44mer inhibit oxygen–glucose deprivation-induced oxidative stress through upregulating PPARγ via PEDF-R in H9c2 cells
Biochemical and biophysical research communications, 2016Co-Authors: Wei Zhuang, Qiuhua Guan, Zhiwei Liu, Hao Zhang, Hongyan Dong, Jiajun Pan, Tengteng Wei, Huazhu Cui, Zhongming ZhangAbstract:Pigment epithelial-derived factor (PEDF) is a glycoprotein with broad biological activities including inhibiting oxygen-glucose deprivation(OGD)-induced cardiomyocytes apoptosis through its anti-oxidative properties. PEDF derived peptide-44mer shows similar cytoprotective effect to PEDF. However, the molecular mechanisms mediating cardiomyocytes apoptosis have not been fully established. Here we found that PEDF and 44mer decreased the content of ROS. This content was abolished by either PEDF-R small interfering RNA (siRNA) or PPARγ antagonist. The level of Lysophosphatidic acid (LPA) and phospholipase A2 (PLA2) was observed as drawn from the ELISA assays. PEDF and 44mer sequentially induced PPARγ expression was observed both in qPCR and Western blot assays. The level of LPA and PLA2 and PPARγ expression increased by PEDF and 44mer was significantly attenuated by PEDF-R siRNA. However, PEDF and 44mer inhibited the H9c2 cells and cultured neonatal rat myocardial cells apoptosis rate. On the other hand, TUNEL assay and cleavage of procaspase-3 showed that PEDF-R siRNA or PPARγ antagonist increased the apoptosis again. We conclude that under OGD condition, PEDF and 44mer reduce H9c2 cells apoptosis and inhibit OGD-induced oxidative stress via its receptor PEDF-R and the PPARγ signaling pathway.
Chuhan Chung - One of the best experts on this subject based on the ideXlab platform.
-
pigment epithelium derived factor PEDF normalizes matrix defects in ipscs derived from osteogenesis imperfecta type vi
Rare diseases (Austin Tex.), 2016Co-Authors: Glenn S. Belinsky, Leanne M Ward, Chuhan ChungAbstract:ABSTRACTOsteogenesis imperfecta (OI) Type VI is characterized by a defect in bone mineralization, which results in multiple fractures early in life. Null mutations in the PEDF gene, Serpinf1, are the cause of OI VI. Whether PEDF restoration in a murine model of OI Type VI could improve bone mass and function was previously unknown. In Belinsky et al, we provided evidence that PEDF delivery enhanced bone mass and improved parameters of bone function in vivo. Further, we demonstrated that PEDF temporally inhibits Wnt signaling to enhance osteoblast differentiation. Here, we demonstrate that generation of induced pluripotent stem cells (iPSCs) from a PEDF null patient provides additional evidence for PEDF's role in regulating extracellular matrix proteins secreted from osteoblasts. PEDF null iPSCs have marked abnormalities in secreted matrix proteins, capturing a key feature of human OI Type VI, which were normalized by exogenous PEDF. Lastly, we place our recent findings within the broader context of PEDF b...
-
pigment epithelium derived factor PEDF inhibits wnt β catenin signaling in the liver
Cellular and molecular gastroenterology and hepatology, 2015Co-Authors: Petr Protiva, Jingjing Gong, Richard Torres, Xuchen Zhang, Glenn S. Belinsky, Mona Cornwell, Susan E. Crawford, Yasuko Iwakiri, Bharath Sreekumar, Chuhan ChungAbstract:Background & Aims Pigment epithelium-derived factor (PEDF) is a secretory protein that inhibits multiple tumor types. PEDF inhibits the Wnt coreceptor, low-density lipoprotein receptor-related protein 6 (LRP6), in the eye, but whether the tumor-suppressive properties of PEDF occur in organs such as the liver is unknown. Methods Wnt-dependent regulation of PEDF was assessed in the absence and presence of the Wnt coreceptor LRP6. Whole genome expression analysis was performed on PEDF knockout (KO) and control livers (7 months). Interrogation of Wnt/β-catenin signaling was performed in whole livers and human hepatocellular carcinoma (HCC) cell lines after RNA interference of PEDF and restoration of a PEDF-derived peptide. Western diet feeding for 6 to 8 months was used to evaluate whether the absence of PEDF was permissive for HCC formation (n = 12/group). Results PEDF levels increased in response to canonical Wnt3a in an LRP6-dependent manner but were suppressed by noncanonical Wnt5a protein in an LRP6-independent manner. Gene set enrichment analysis (GSEA) of PEDF KO livers revealed induction of pathways associated with experimental and human HCC and a transcriptional profile characterized by Wnt/β-catenin activation. Enhanced Wnt/β-catenin signaling occurred in KO livers, and PEDF delivery in vivo reduced LRP6 activation. In human HCC cells, RNA interference of PEDF led to increased levels of activated LRP6 and β-catenin, and a PEDF 34-mer peptide decreased LRP6 activation and β-catenin signaling, and reduced Wnt target genes. PEDF KO mice fed a Western diet developed sporadic well-differentiated HCC. Human HCC specimens demonstrated decreased PEDF staining compared with hepatocytes. Conclusions PEDF is an endogenous inhibitor of Wnt/β-catenin signaling in the liver.
-
Pigment Epithelium-Derived Factor (PEDF) Inhibits Wnt/β-catenin Signaling in the Liver.
Cellular and molecular gastroenterology and hepatology, 2015Co-Authors: Petr Protiva, Jingjing Gong, Bharath K. Sreekumar, Richard Torres, Xuchen Zhang, Glenn S. Belinsky, Mona Cornwell, Susan E. Crawford, Yasuko Iwakiri, Chuhan ChungAbstract:Background & Aims Pigment epithelium-derived factor (PEDF) is a secretory protein that inhibits multiple tumor types. PEDF inhibits the Wnt coreceptor, low-density lipoprotein receptor-related protein 6 (LRP6), in the eye, but whether the tumor-suppressive properties of PEDF occur in organs such as the liver is unknown. Methods Wnt-dependent regulation of PEDF was assessed in the absence and presence of the Wnt coreceptor LRP6. Whole genome expression analysis was performed on PEDF knockout (KO) and control livers (7 months). Interrogation of Wnt/β-catenin signaling was performed in whole livers and human hepatocellular carcinoma (HCC) cell lines after RNA interference of PEDF and restoration of a PEDF-derived peptide. Western diet feeding for 6 to 8 months was used to evaluate whether the absence of PEDF was permissive for HCC formation (n = 12/group). Results PEDF levels increased in response to canonical Wnt3a in an LRP6-dependent manner but were suppressed by noncanonical Wnt5a protein in an LRP6-independent manner. Gene set enrichment analysis (GSEA) of PEDF KO livers revealed induction of pathways associated with experimental and human HCC and a transcriptional profile characterized by Wnt/β-catenin activation. Enhanced Wnt/β-catenin signaling occurred in KO livers, and PEDF delivery in vivo reduced LRP6 activation. In human HCC cells, RNA interference of PEDF led to increased levels of activated LRP6 and β-catenin, and a PEDF 34-mer peptide decreased LRP6 activation and β-catenin signaling, and reduced Wnt target genes. PEDF KO mice fed a Western diet developed sporadic well-differentiated HCC. Human HCC specimens demonstrated decreased PEDF staining compared with hepatocytes. Conclusions PEDF is an endogenous inhibitor of Wnt/β-catenin signaling in the liver.
-
PEDF & Stem Cells: Niche vs. Nurture
Current drug delivery, 2014Co-Authors: Philip Fitchev, Chuhan Chung, Beth A. Plunkett, Charles B. Brendler, Susan E. CrawfordAbstract:Anti-angiogenic pigment epithelium-derived factor (PEDF) is a multifunctional 50kD secreted glycoprotein emerging as a key factor in stem cell renewal. Characteristics of the stem cell niche can be highly dependent on location, access to the vasculature, oxygen tension and neighboring cells. In the neural stem cell (NSC) niche, specifically the subventricular zone, PEDF actively participates in the self renewal process and promotes stemness by upregulating Notch signaling effectors Hes1 and Hes5. The local vascular endothelial cells and ependymal cells are the likely sources of PEDF for the NSC while mesenchymal and retinal stem cells can actually produce PEDF. The opposing actions of PEDF and VEGF on various cells are recapitulated in the NSC niche. Intraventricular injection of PEDF promotes stem cell renewal, while injection of VEGF prompts differentiation and neurogenesis in the subventricular zone. Enhancing the expression of PEDF in stem cells has promising therapeutic implications. Bone marrow mesenchymal stem cells overexpressing PEDF effectively inhibited pathologic angiogenesis in the murine eye and these same cells suppressed hepatocellular carcinoma growth. As a protein with bioactivities in nearly all normal organ systems, it is likely that PEDF will continue to gain visibility as an essential component in the development and delivery of novel stem cell-based therapies to combat disease.
-
pigment epithelium derived factor PEDF suppresses il 1β mediated c jun n terminal kinase jnk activation to improve hepatocyte insulin signaling
Endocrinology, 2014Co-Authors: Arijeet K. Gattu, Petr Protiva, Susan E. Crawford, Yasuko Iwakiri, Jennifer A. Doll, Andreas L Birkenfeld, Steven M Jay, Mark Saltzman, Varman T Samuel, Chuhan ChungAbstract:Pigment epithelium-derived factor (PEDF) is an antiinflammatory protein that circulates at high levels in the metabolic syndrome. Metabolic studies of PEDF knockout (KO) mice were conducted to investigate the relationship between PEDF, inflammatory markers, and metabolic homeostasis. Male PEDF KO mice demonstrated a phenotype consisting of increased adiposity, glucose intolerance, and elevated serum levels of metabolites associated with the metabolic syndrome. Genome expression analysis revealed an increase in IL-1β signaling in the livers of PEDF KO mice that was accompanied by impaired IRS and Akt signaling. In human hepatocytes, PEDF blocked the effects of an IL-1β challenge by suppressing activation of the inflammatory mediator c-Jun N-terminal kinase while restoring Akt signaling. RNA interference of PEDF in human hepatocytes was permissive for c-Jun N-terminal kinase activation and decreased Akt signaling. A metabolomics profile identified elevated circulating levels of tricarboxyclic acid cycle int...
Thomas Nelius - One of the best experts on this subject based on the ideXlab platform.
-
PEDF increases the tumoricidal activity of macrophages towards prostate cancer cells in vitro.
PloS one, 2017Co-Authors: Dalia Martinez-marin, Courtney Jarvis, Thomas Nelius, Werner De Riese, Olga V. Volpert, Stephanie FilleurAbstract:Background Although inflammation and prostate cancer (PCa) have been linked, the molecular interactions between macrophages and PCa cells are poorly explored. Pigment Epithelium-Derived Factor (PEDF) is an anti-angiogenic and anti-tumor factor. We previously showed that PEDF induces macrophages recruitment in vitro, correlates with macrophages density in human prostate, and stimulates macrophages polarization towards the classically activated pathway. Here, we demonstrate that PEDF modulates the interaction between macrophages and PCa cells through a bidirectional signalling leading to tumor cell apoptosis and phagocytosis. Methods RAW 264.7 and THP-1 cells, and BMDMs were grown in vitro as mono- or co-cultures with PC3 or CL1 tumor cells. The effects of PEDF and its derived P18 peptide were measured on macrophages differentiation, migration, and superoxide production, and tumor cell apoptosis and phagocytosis. PEDF receptors (ATP5B, PNPLA2, and LRP6) and CD47 mRNA and protein expression were quantified in macrophages and tumor cells by quantitative RT-PCR, western blot, immunofluorescence and flow cytometry. Results We found that PEDF induced the migration of macrophages towards tumor 3D spheroids and 2D cultures. In co-culture, PEDF increased PCa cells phagocytosis through an indirect apoptosis-dependent mechanism. Moreover, PEDF stimulated the production of superoxide by macrophages. Conditioned media from macrophages exposed to PEDF induced tumor cells apoptosis in contrast to control conditioned media suggesting that ROS may be involved in tumor cells apoptosis. ATP5B and PNPLA2 PEDF receptors on macrophages and CD47 on tumor cells were respectively up- and down-regulated by PEDF. As PEDF, blocking CD47 induced phagocytosis. Inhibiting ATP5B reduced phagocytosis. Inversely, PNPLA2 inhibition blocks differentiation but maintains phagocytosis. CD47-induced phagocytosis was partially reverted by ATP5B inhibition suggesting a complementary action. Similar effects were observed with P18 PEDF-derived peptide. Conclusions These data established that modulating the molecular interactions between macrophages and PCa cells using PEDF may be a promising strategy for PCa treatment.
-
Abstract 3359: PEDF modulatory action on macrophages: A new way to curb prostate cancer development
Tumor Biology, 2015Co-Authors: Dalia Martinez-marin, Thomas Nelius, Olga V. Volpert, Stephanie FilleurAbstract:Macrophages have been described as one of the main inflammatory components involved in prostate cancer (PCa) initiation, progression, and metastasis. PEDF (Pigment Epithelium-Derived Factor) is an anti-angiogenic factor with differentiation activities and was recently suggested as an immune-modulating factor. PEDF expression has been shown to be down-regulated in PCa compared to normal tissues. In previous studies we have demonstrated that PEDF re-expression in PCa cells curbs tumor growth in vivo and significantly prolongs the survival of tumor-bearing mice. Others have shown that PEDF expression increased the recruitment of tumor-cytotoxic macrophages into orthotopic MatLyLu rat prostate tumors suggesting a link between PEDF and inflammation in PCa. While PEDF9s role in inflammation has been suggested, the precise modes of action of PEDF on macrophages still remain unknown and necessitate further investigation. Our preliminary data have showed that PEDF stimulates the migration of monocytes/macrophages using in vitro chemotaxis boyden chamber assay and towards tumor 3D spheroids. We showed that PEDF expression levels positively correlate with macrophage density in human prostate. In both cell lines and prostate specimens, we have demonstrated that PEDF directly induces the polarization of macrophages and bone marrow derived macrophages (BMDMs) towards a M1/tumor-cytotoxic pathway. As a result of their differentiation, we have found that PEDF stimulates the phagocytosis of tumor cells, which suggest another mechanism by which PCa growth is halted. We are currently investigating the molecular mechanisms by which PEDF induces migration, differentiation and phagocytic activity in macrophages. PEDF mechanisms are being investigated by expression levels of PEDF receptors (ATP5B, PNPLA2, LRP6) in macrophage cell lines and BMDMs. So far we have been identified ATP5B and PNPLA2 as the two main receptors expressed in both cell types. While all three receptors in cell lines increased, only ATP5B and PNPLA2 receptors increased in BMDMs in response to PEDF. To map the functional region involved in PEDF9s inflammatory action, we are investigating the PEDF-derivative synthetic 18-mer peptide (residues 39-57). P18 has been shown to block endothelial cell chemotaxis and induces apoptosis in vitro, and to be more effective than its parental 34-mer peptide (residues 24-57) in blocking growth and angiogenesis in PCa. We were able to demonstrate that macrophages treated with P18 in comparison to PEDF, show a higher efficacy for macrophages differentiation. Using confocal microscopy we demonstrated a larger rate of phagocytosis of PCa cells by macrophages than compared to PEDF. The results of our study are of importance as they suggest that macrophages may play a key role in PEDF anti-tumor effects. A better understanding of PEDF may lead to further development of PEDF-based anticancer therapy or improvement of alternatives to chemotherapy for PCa. Citation Format: Dalia Martinez-Marin, Thomas Nelius, Olga Volpert, Stephanie Filleur. PEDF modulatory action on macrophages: A new way to curb prostate cancer development. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3359. doi:10.1158/1538-7445.AM2015-3359
-
Positive correlation between PEDF expression levels and macrophage density in the human prostate.
Prostate, 2013Co-Authors: Thomas Nelius, Dalia Martinez-marin, Werner De Riese, Christina A. Samathanam, Natalie Gaines, Jessica Stevens, Johnny Hickson, Stephanie FilleurAbstract:BACKGROUND: In this study, we investigated the capacity of pigment epithelium-derived factor (PEDF) to modulate the recruitment and the differentiation of monocytes/macrophages both in vitro and in human prostate. METHODS: Using Boyden chambers, we assessed PEDF effect on the migration of monocytes and chemically activated RAW 264.7 macrophages. Normal, prostatitis, and prostate cancer specimens were retrospectively selected and examined by immunohistochemistry for PEDF expression and infiltration of immune CD68 + macrophagic cells. PEDF expression and macrophage density were then correlated with each other and clinicopathological parameters. M1 and M2 differentiation markers were quantified by qRT-PCR, Western blotting, and ELISA. RESULTS: In chemotaxis, PEDF induced the migration of monocytes/macrophages. In immunohistochemistry, macrophages were markedly increased in prostatitis and malignant compared to normal tissues. PEDF was expressed at variable levels in the stroma and epithelium. PEDF mRNA was down-regulated in both prostate cancer and prostatitis compared to normal tissues. In correlation studies, macrophage density and PEDF expression were respectively positively and negatively associated with prostate size. Most importantly, PEDF expression positively correlated with macrophage density. Finally, PEDF stimulated the expression of iNOS, IL12, and TNFα; and inhibited IL10 and arginase 1 in mouse and human macrophages confirming a M1-type differentiation. CONCLUSIONS: Our data demonstrate that PEDF acts directly on monocytes/macrophages by inducing their migration and differentiation into M1-type cells. These findings suggest a possible role of macrophages in PEDF anti-tumor properties and may support further development of PEDF-based anti-cancer therapy.
-
Effect of PEDF on the in vivo antitumor activities of low-dose chemotherapy in CRPC.
Journal of Clinical Oncology, 2013Co-Authors: Thomas Nelius, Jennifer Hirsch, Everardo Cobos, Stephanie FilleurAbstract:173 Background: The development of metronomic/low dose administration of conventional chemotherapeutic drugs has shown great promise in the treatment of castration-refractory prostate cancer (CPRC). Pigment Epithelium-Derived Factor (PEDF) is a natural angio-inhibitor which is down-regulated in prostate cancer. We have previously demonstrated that the over-expression of PEDF in human CRPC PC3 cells decreased tumor growth in vivo. In the present study, we further validated PEDF anti-tumor properties in the highly metastatic CRPC LNCaP-derivative CL1 cells. We also hypothesized that PEDF may enhance the cytotoxicity effects of low dose docetaxel (DTX) and cyclophosphamide (CTX) chemotherapies in vivo. Methods: PC3 and CL1 cell lines were genetically modified to stably express the fluorescent DsRed Express protein with PEDF. Resulting cells were characterized in vitro for PEDF expression by western blot and, for proliferation by growth curves and clone formation in matrigel. PEDF anti-tumor effects were asse...
-
Positive correlation between PEDF expression levels and macrophage density in the human prostate
The Prostate, 2012Co-Authors: Thomas Nelius, Dalia Martinez-marin, Werner De Riese, Christina A. Samathanam, Natalie Gaines, Jessica Stevens, Johnny Hickson, Stephanie FilleurAbstract:BACKGROUND In this study, we investigated the capacity of pigment epithelium-derived factor (PEDF) to modulate the recruitment and the differentiation of monocytes/macrophages both in vitro and in human prostate. METHODS Using Boyden chambers, we assessed PEDF effect on the migration of monocytes and chemically activated RAW 264.7 macrophages. Normal, prostatitis, and prostate cancer specimens were retrospectively selected and examined by immunohistochemistry for PEDF expression and infiltration of immune CD68 + macrophagic cells. PEDF expression and macrophage density were then correlated with each other and clinicopathological parameters. M1 and M2 differentiation markers were quantified by qRT-PCR, Western blotting, and ELISA. RESULTS In chemotaxis, PEDF induced the migration of monocytes/macrophages. In immunohistochemistry, macrophages were markedly increased in prostatitis and malignant compared to normal tissues. PEDF was expressed at variable levels in the stroma and epithelium. PEDF mRNA was down-regulated in both prostate cancer and prostatitis compared to normal tissues. In correlation studies, macrophage density and PEDF expression were respectively positively and negatively associated with prostate size. Most importantly, PEDF expression positively correlated with macrophage density. Finally, PEDF stimulated the expression of iNOS, IL12, and TNFα; and inhibited IL10 and arginase 1 in mouse and human macrophages confirming a M1-type differentiation. CONCLUSIONS Our data demonstrate that PEDF acts directly on monocytes/macrophages by inducing their migration and differentiation into M1-type cells. These findings suggest a possible role of macrophages in PEDF anti-tumor properties and may support further development of PEDF-based anti-cancer therapy. Prostate 73: 549–561, 2013. © 2012 Wiley Periodicals, Inc.