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Norrie JL, Lupo MS, Little DR, Shirinifard A, Mishra A, Zhang Q, Geiger N, Putnam D, Djekidel N, Ramirez C, Xu B, Dundee JM, Yu J, Chen X, Dyer MA. Latent epigenetic programs in Müller glia contribute to stress and disease response in the retina. Dev Cell 2025; 60:1199-1216.e7. [PMID: 39753128 PMCID: PMC12014377 DOI: 10.1016/j.devcel.2024.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 07/09/2024] [Accepted: 12/06/2024] [Indexed: 04/24/2025]
Abstract
Previous studies have demonstrated the dynamic changes in chromatin structure during retinal development correlate with changes in gene expression. However, those studies lack cellular resolution. Here, we integrate single-cell RNA sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin sequencing (scATAC-seq) with bulk data to identify cell-type-specific changes in chromatin structure during human and murine development. Although promoter activity is correlated with chromatin accessibility, we discovered several hundred genes that were transcriptionally silent but had accessible chromatin at their promoters. Most of those silent/accessible gene promoters were in Müller glial cells, which function to maintain retinal homeostasis and respond to stress, injury, or disease. We refer to these as "pliancy genes" because they allow the Müller glia to rapidly change their gene expression and cellular state in response to retinal insults. The Müller glial cell pliancy program is established during development, and we demonstrate that pliancy genes are important for regulating inflammation in the murine retina in vivo.
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Affiliation(s)
- Jackie L Norrie
- Departments of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Marybeth S Lupo
- Departments of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Danielle R Little
- Departments of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Abbas Shirinifard
- Departments of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Akhilesh Mishra
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Qiong Zhang
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Natalie Geiger
- Departments of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Daniel Putnam
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Nadhir Djekidel
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Cody Ramirez
- Departments of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Beisi Xu
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jacob M Dundee
- Departments of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jiang Yu
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Xiang Chen
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Michael A Dyer
- Departments of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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Norrie JL, Lupo M, Shirinifard A, Djekidel N, Ramirez C, Xu B, Dundee JM, Dyer MA. Latent Epigenetic Programs in Müller Glia Contribute to Stress, Injury, and Disease Response in the Retina. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.15.562396. [PMID: 37905050 PMCID: PMC10614790 DOI: 10.1101/2023.10.15.562396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Previous studies have demonstrated the dynamic changes in chromatin structure during retinal development that correlate with changes in gene expression. However, a major limitation of those prior studies was the lack of cellular resolution. Here, we integrate single-cell (sc) RNA-seq and scATAC-seq with bulk retinal data sets to identify cell type-specific changes in the chromatin structure during development. Although most genes' promoter activity is strongly correlated with chromatin accessibility, we discovered several hundred genes that were transcriptionally silent but had accessible chromatin at their promoters. Most of those silent/accessible gene promoters were in the Müller glial cells. The Müller cells are radial glia of the retina and perform a variety of essential functions to maintain retinal homeostasis and respond to stress, injury, or disease. The silent/accessible genes in Müller glia are enriched in pathways related to inflammation, angiogenesis, and other types of cell-cell signaling and were rapidly activated when we tested 15 different physiologically relevant conditions to mimic retinal stress, injury, or disease in human and murine retinae. We refer to these as "pliancy genes" because they allow the Müller glia to rapidly change their gene expression and cellular state in response to different types of retinal insults. The Müller glial cell pliancy program is established during development, and we demonstrate that pliancy genes are necessary and sufficient for regulating inflammation in the murine retina in vivo. In zebrafish, Müller glia can de-differentiate and form retinal progenitor cells that replace lost neurons. The pro-inflammatory pliancy gene cascade is not activated in zebrafish Müller glia following injury, and we propose a model in which species-specific pliancy programs underly the differential response to retinal damage in species that can regenerate retinal neurons (zebrafish) versus those that cannot (humans and mice).
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Du Y, Yan B. Ocular immune privilege and retinal pigment epithelial cells. J Leukoc Biol 2023; 113:288-304. [PMID: 36805720 DOI: 10.1093/jleuko/qiac016] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Indexed: 02/04/2023] Open
Abstract
The ocular tissue microenvironment is immune-privileged and uses multiple immunosuppressive mechanisms to prevent the induction of inflammation. The retinal pigment epithelium plays an essential role in ocular immune privilege. In addition to serving as a blood barrier separating the fenestrated choriocapillaris from the retina, the retinal pigment epithelium is a source of immunosuppressive cytokines and membrane-bound negative regulators that modulate the activity of immune cells within the retina. This article reviews the current understanding of how retinal pigment epithelium cells mediate immune regulation, focusing on the changes under pathologic conditions.
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Affiliation(s)
- Yuxiang Du
- Institute of Precision Medicine, Jining Medical University, No. 133, Hehua Road, Taibaihu New District, Jining, Shandong 272067, People's Republic of China
| | - Bo Yan
- Institute of Precision Medicine, Jining Medical University, No. 133, Hehua Road, Taibaihu New District, Jining, Shandong 272067, People's Republic of China
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McClellan K, Chen EY, Kardosh A, Lopez CD, Del Rivero J, Mallak N, Rocha FG, Koethe Y, Pommier R, Mittra E, Pegna GJ. Therapy Resistant Gastroenteropancreatic Neuroendocrine Tumors. Cancers (Basel) 2022; 14:4769. [PMID: 36230691 PMCID: PMC9563314 DOI: 10.3390/cancers14194769] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/24/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022] Open
Abstract
Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a heterogenous group of malignancies originating from neuroendocrine cells of the gastrointestinal tract, the incidence of which has been increasing for several decades. While there has been significant progress in the development of therapeutic options for patients with advanced or metastatic disease, these remain limited both in quantity and durability of benefit. This review examines the latest research elucidating the mechanisms of both up-front resistance and the eventual development of resistance to the primary systemic therapeutic options including somatostatin analogues, peptide receptor radionuclide therapy with lutetium Lu 177 dotatate, everolimus, sunitinib, and temozolomide-based chemotherapy. Further, potential strategies for overcoming these mechanisms of resistance are reviewed in addition to a comprehensive review of ongoing and planned clinical trials addressing this important challenge.
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Affiliation(s)
- Kristen McClellan
- School of Medicine, Oregon Health & Science University, Portland, OR 97239, USA
| | - Emerson Y. Chen
- Division of Hematology Oncology, Knight Cancer Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Adel Kardosh
- Division of Hematology Oncology, Knight Cancer Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Charles D. Lopez
- Division of Hematology Oncology, Knight Cancer Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Jaydira Del Rivero
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nadine Mallak
- Division of Molecular Imaging and Therapy, Oregon Health & Science University, Portland, OR 97239, USA
| | - Flavio G. Rocha
- Division of Surgical Oncology, Department of Surgery, Oregon Health & Science University, Portland, OR 97239, USA
| | - Yilun Koethe
- Dotter Department of Interventional Radiology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Rodney Pommier
- Division of Surgical Oncology, Department of Surgery, Oregon Health & Science University, Portland, OR 97239, USA
| | - Erik Mittra
- Division of Molecular Imaging and Therapy, Oregon Health & Science University, Portland, OR 97239, USA
| | - Guillaume J. Pegna
- Division of Hematology Oncology, Knight Cancer Institute, Oregon Health & Science University, Portland, OR 97239, USA
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Khalifa AA, El Sokkary NH, Elblehi SS, Diab MA, Ali MA. Potential cardioprotective effect of octreotide via NOXs mitigation, mitochondrial biogenesis and MAPK/Erk1/2/STAT3/NF-kβ pathway attenuation in isoproterenol-induced myocardial infarction in rats. Eur J Pharmacol 2022; 925:174978. [DOI: 10.1016/j.ejphar.2022.174978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 04/13/2022] [Accepted: 04/22/2022] [Indexed: 11/03/2022]
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Cheng Z, Li Y, Zhu X, Wang K, Ali Y, Shu W, Zhang T, Zhu L, Murray M, Zhou F. The Potential Application of Pentacyclic Triterpenoids in the Prevention and Treatment of Retinal Diseases. PLANTA MEDICA 2021; 87:511-527. [PMID: 33761574 DOI: 10.1055/a-1377-2596] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Retinal diseases are a leading cause of impaired vision and blindness but some lack effective treatments. New therapies are required urgently to better manage retinal diseases. Natural pentacyclic triterpenoids and their derivatives have a wide range of activities, including antioxidative, anti-inflammatory, cytoprotective, neuroprotective, and antiangiogenic properties. Pentacyclic triterpenoids have great potential in preventing and/or treating retinal pathologies. The pharmacological effects of pentacyclic triterpenoids are often mediated through the modulation of signalling pathways, including nuclear factor erythroid-2 related factor 2, high-mobility group box protein 1, 11β-hydroxysteroid dehydrogenase type 1, and Src homology region 2 domain-containing phosphatase-1. This review summarizes recent in vitro and in vivo evidence for the pharmacological potential of pentacyclic triterpenoids in the prevention and treatment of retinal diseases. The present literature supports the further development of pentacyclic triterpenoids. Future research should now attempt to improve the efficacy and pharmacokinetic behaviour of the agents, possibly by the use of medicinal chemistry and targeted drug delivery strategies.
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Affiliation(s)
- Zhengqi Cheng
- Sydney Pharmacy School, The University of Sydney, Camperdown, Australia
| | - Yue Li
- Sydney Pharmacy School, The University of Sydney, Camperdown, Australia
| | - Xue Zhu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, China
| | - Ke Wang
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, China
| | - Youmna Ali
- Sydney Pharmacy School, The University of Sydney, Camperdown, Australia
| | - Wenying Shu
- Department of Pharmacy, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Ting Zhang
- Save Sight Institute, The University of Sydney, Sydney, Australia
| | - Ling Zhu
- Save Sight Institute, The University of Sydney, Sydney, Australia
| | - Michael Murray
- Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
| | - Fanfan Zhou
- Sydney Pharmacy School, The University of Sydney, Camperdown, Australia
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Rossino MG, Lulli M, Amato R, Cammalleri M, Dal Monte M, Casini G. Oxidative Stress Induces a VEGF Autocrine Loop in the Retina: Relevance for Diabetic Retinopathy. Cells 2020; 9:E1452. [PMID: 32545222 PMCID: PMC7349409 DOI: 10.3390/cells9061452] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 06/01/2020] [Accepted: 06/10/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Oxidative stress (OS) plays a central role in diabetic retinopathy (DR), triggering expression and release of vascular endothelial growth factor (VEGF), the increase of which leads to deleterious vascular changes. We tested the hypothesis that OS-stimulated VEGF induces its own expression with an autocrine mechanism. METHODS MIO-M1 cells and ex vivo mouse retinal explants were treated with OS, with exogenous VEGF or with conditioned media (CM) from OS-stressed cultures. RESULTS Both in MIO-M1 cells and in retinal explants, OS or exogenous VEGF induced a significant increase of VEGF mRNA, which was abolished by VEGF receptor 2 (VEGFR-2) inhibition. OS also caused VEGF release. In MIO-M1 cells, CM induced VEGF expression, which was abolished by a VEGFR-2 inhibitor. Moreover, the OS-induced increase of VEGF mRNA was abolished by a nuclear factor erythroid 2-related factor 2 (Nrf2) blocker, while the effect of exo-VEGF resulted Nrf2-independent. Finally, both the exo-VEGF- and the OS-induced increase of VEGF expression were blocked by a hypoxia-inducible factor-1 inhibitor. CONCLUSIONS These results are consistent with the existence of a retinal VEGF autocrine loop triggered by OS. This mechanism may significantly contribute to the maintenance of elevated VEGF levels and therefore it may be of central importance for the onset and development of DR.
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Affiliation(s)
- Maria Grazia Rossino
- Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.G.R.); (R.A.); (M.C.)
| | - Matteo Lulli
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50134 Florence, Italy;
| | - Rosario Amato
- Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.G.R.); (R.A.); (M.C.)
| | - Maurizio Cammalleri
- Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.G.R.); (R.A.); (M.C.)
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, 56124 Pisa, Italy
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.G.R.); (R.A.); (M.C.)
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, 56124 Pisa, Italy
| | - Giovanni Casini
- Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.G.R.); (R.A.); (M.C.)
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, 56124 Pisa, Italy
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8
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Amato R, Giannaccini M, Dal Monte M, Cammalleri M, Pini A, Raffa V, Lulli M, Casini G. Association of the Somatostatin Analog Octreotide With Magnetic Nanoparticles for Intraocular Delivery: A Possible Approach for the Treatment of Diabetic Retinopathy. Front Bioeng Biotechnol 2020; 8:144. [PMID: 32158755 PMCID: PMC7051943 DOI: 10.3389/fbioe.2020.00144] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/12/2020] [Indexed: 12/17/2022] Open
Abstract
The somatostatin analog octreotide (OCT) displays important neuroprotective and anti-angiogenic properties that could make it an interesting candidate to treat diabetic retinopathy (DR). Unfortunately, systemic drug administration is hindered by severe side effects, therefore topical administration routes are preferable. However, drug delivery through eye drops may be difficult due to ocular barriers and, in the long term, could induce ocular damage. On the other hand, intraocular injections must be repeated to maintain drug concentration, and this may cause severe damage to the eye. To decrease injection frequency, long-term release and reduced biodegradation could be obtained by binding the drug to biodegradable polymeric nanoparticles. In the present study, we made a preparation of OCT bound to magnetic nanoparticles (MNP-OCT) and tested its possible use as an OCT delivery system to treat retinal pathologies such as DR. In particular, in vitro, ex vivo, and in vivo experimental models of the mammalian retina were used to investigate the possible toxicity of MNPs, possible effects of the binding to MNPs on OCT bioactivity, and the localization of MNP-OCT in the retina after intraocular injection. The results showed that, both in human retinal endothelial cells (HRECs) and in mouse retinal explants, MNPs were not toxic and the binding with MNPs did not influence OCT antiangiogenic or antiapoptotic activity. Rather, effects of MNP-OCT were observed at concentrations up to 100-fold (in HRECs) or 10-fold (in mouse retinal explants) lower compared to OCT, indicating that OCT bioactivity was enhanced in MNP-OCT. MNP-OCT in mouse retinas in vivo after intraocular delivery were initially localized mainly to the outer retina, at the level of the retinal pigment epithelium, while after 5 days they were observed throughout the retinal thickness. These observations demonstrate that MNP-OCT may be used as an OCT intraocular delivery system that may ensure OCT localization to the retina and enhanced OCT bioactivity. Further studies will be necessary to determine the OCT release rate in the retina and the persistence of drug effects in the long period.
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Affiliation(s)
- Rosario Amato
- Department of Biology, University of Pisa, Pisa, Italy
| | | | - Massimo Dal Monte
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| | - Maurizio Cammalleri
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| | - Alessandro Pini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | | | - Matteo Lulli
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Giovanni Casini
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
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9
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Rossino MG, Dal Monte M, Casini G. Relationships Between Neurodegeneration and Vascular Damage in Diabetic Retinopathy. Front Neurosci 2019; 13:1172. [PMID: 31787868 PMCID: PMC6856056 DOI: 10.3389/fnins.2019.01172] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 10/16/2019] [Indexed: 12/15/2022] Open
Abstract
Diabetic retinopathy (DR) is a common complication of diabetes and constitutes a major cause of vision impairment and blindness in the world. DR has long been described exclusively as a microvascular disease of the eye. However, in recent years, a growing interest has been focused on the contribution of neuroretinal degeneration to the pathogenesis of the disease, and there are observations suggesting that neuronal death in the early phases of DR may favor the development of microvascular abnormalities, followed by the full manifestation of the disease. However, the mediators that are involved in the crosslink between neurodegeneration and vascular changes have not yet been identified. According to our hypothesis, vascular endothelial growth factor (VEGF) could probably be the most important connecting link between the death of retinal neurons and the occurrence of microvascular lesions. Indeed, VEGF is known to play important neuroprotective actions; therefore, in the early phases of DR, it may be released in response to neuronal suffering, and it would act as a double-edged weapon inducing both neuroprotective and vasoactive effects. If this hypothesis is correct, then any retinal stress causing neuronal damage should be accompanied by VEGF upregulation and by vascular changes. Similarly, any compound with neuroprotective properties should also induce VEGF downregulation and amelioration of the vascular lesions. In this review, we searched for a correlation between neurodegeneration and vasculopathy in animal models of retinal diseases, examining the effects of different neuroprotective substances, ranging from nutraceuticals to antioxidants to neuropeptides and others and showing that reducing neuronal suffering also prevents overexpression of VEGF and vascular complications. Taken together, the reviewed evidence highlights the crucial role played by mediators such as VEGF in the relationship between retinal neuronal damage and vascular alterations and suggests that the use of neuroprotective substances could be an efficient strategy to prevent the onset or to retard the development of DR.
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Affiliation(s)
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| | - Giovanni Casini
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
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10
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Gábriel R, Pöstyéni E, Dénes V. Neuroprotective Potential of Pituitary Adenylate Cyclase Activating Polypeptide in Retinal Degenerations of Metabolic Origin. Front Neurosci 2019; 13:1031. [PMID: 31649495 PMCID: PMC6794456 DOI: 10.3389/fnins.2019.01031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/12/2019] [Indexed: 01/06/2023] Open
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP1-38) is a highly conserved member of the secretin/glucagon/VIP family. The repressive effect of PACAP1-38 on the apoptotic machinery has been an area of active research conferring a significant neuroprotective potential onto this peptide. A remarkable number of studies suggest its importance in the etiology of neurodegenerative disorders, particularly in relation to retinal metabolic disorders. In our review, we provide short descriptions of various pathological conditions (diabetic retinopathy, excitotoxic retinal injury and ischemic retinal lesion) in which the remedial effect of PACAP has been well demonstrated in various animal models. Of all the pathological conditions, diabetic retinopathy seems to be the most intriguing as it develops in 75% of patients with type 1 and 50% of patients with type 2 diabetes, with concomitant progression to legal blindness in about 5%. Several animal models have been developed in recent years to study retinal degenerations and out of these glaucoma and age-related retina degeneration models bear human recapitulations. PACAP neuroprotection is thought to operate through enhanced cAMP production upon binding to PAC1-R. However, the underlying signaling network that leads to neuroprotection is not fully understood. We observed that (i) PACAP is not equally efficient in the above conditions; (ii) in some cases more than one signaling pathways are activated; (iii) the coupling of PAC1-R and signaling is stage dependent; and (iv) PAC1-R is not the only receptor that must be considered to interpret the effects in our experiments. These observations point to a complex signaling mechanism, that involves alternative routes besides the classical cAMP/protein kinase A pathway to evoke the outstanding neuroprotective action. Consequently, the possible contribution of the other two main receptors (VPAC1-R and VPAC2-R) will also be discussed. Finally, the potential medical use of PACAP in some retinal and ocular disorders will also be reviewed. By taking advantage of, low-cost synthesis technologies today, PACAP may serve as an alternative to the expensive treatment modelities currently available in ocular or retinal conditions.
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Affiliation(s)
- Robert Gábriel
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary.,János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Etelka Pöstyéni
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Viktória Dénes
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
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11
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Cammalleri M, Dal Monte M, Locri F, Pecci V, De Rosa M, Pavone V, Bagnoli P. The urokinase-type plasminogen activator system as drug target in retinitis pigmentosa: New pre-clinical evidence in the rd10 mouse model. J Cell Mol Med 2019; 23:5176-5192. [PMID: 31251468 PMCID: PMC6653070 DOI: 10.1111/jcmm.14391] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/05/2019] [Accepted: 05/02/2019] [Indexed: 12/14/2022] Open
Abstract
Retinitis pigmentosa (RP) is characterized by progressive loss of vision due to photoreceptor degeneration leading to secondary inflammation. The urokinase-type plasminogen activator (uPA) system contributes to retinal inflammation, but its role in RP is unknown. In the rd10 mouse model of RP, we addressed this question with the use of the peptide UPARANT designed to interact with the uPA system. UPARANT was systemically administered from post-natal day (PD) 10 to PD30 when its efficacy in RP rescue was investigated using electroretinographic recordings, Western blot and immunocytochemistry. Temporal profile of protein expression in the uPA system was also investigated. UPARANT reduced both Müller cell gliosis and up-regulated levels of inflammatory markers and exerted major anti-apoptotic effects without influencing the autophagy cascade. Rescue from retinal cell degeneration was accompanied by improved retinal function. No scotopic phototransduction was rescued in the UPARANT-treated animals as determined by the kinetic analysis of rod-mediated a-waves and confirmed by rod photoreceptor markers. In contrast, the cone photopic b-wave was recovered and its rescue was confirmed in the whole mounts using cone arrestin antibody. Investigation of the uPA system regulation over RP progression revealed extremely low levels of uPA and its receptor uPAR both of which were recovered by HIF-1α stabilization indicating that HIF-1 regulates the expression of the uPA/uPAR gene in the retina. Ameliorative effects of UPARANT were likely to occur through an inhibitory action on up-regulated activity of the αvβ3 integrin/Rac1 pathway that was suggested as a novel target for the development of therapeutic approaches against RP.
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Affiliation(s)
| | | | - Filippo Locri
- Department of Biology, University of Pisa, Pisa, Italy
| | - Valeria Pecci
- Department of Biology, University of Pisa, Pisa, Italy
| | - Mario De Rosa
- Department of Experimental Medicine, Second University of Napoli, Napoli, Italy
| | - Vincenzo Pavone
- Department of Chemical Sciences, University of Napoli Federico II, Napoli, Italy
| | - Paola Bagnoli
- Department of Biology, University of Pisa, Pisa, Italy
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12
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Zunino V, Catalano MG, Zenga F, Penner F, Maletta F, Valerio F, Rinella L, Arvat E, Fortunati N. Benzene affects the response to octreotide treatment of growth hormone secreting pituitary adenoma cells. ENVIRONMENTAL RESEARCH 2019; 173:489-496. [PMID: 30986651 DOI: 10.1016/j.envres.2019.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/05/2019] [Accepted: 04/07/2019] [Indexed: 06/09/2023]
Abstract
Growth hormone (GH) secreting pituitary adenomas are the main cause of acromegaly. Somatostatin analogs are the gold standard of medical therapy; however, resistance represents a big drawback in acromegaly management. We recently demonstrated that benzene (BZ) modifies the aggressiveness of GH-secreting rat pituitary adenoma cells (GH3), increasing GH secretion and altering the synthesis of molecules involved in the somatostatin signaling pathway. Based on these pieces of evidence, this study aimed to evaluate the effects of BZ on octreotide (OCT) efficacy in GH-secreting adenoma cells. In GH3 cells, BZ counteracted the anti-proliferative action of OCT. GH gene expression, unmodified by OCT, remained high in BZ-treated cells as well as after treatment with the association of both. GH secretion, reduced by OCT, was increased after treatment with BZ alone or when the pollutant was used with OCT. The combination of BZ and OCT greatly reduced the gene expression of ZAC1 and SSTR2; and this reduction was also present at a protein level. BZ caused an increase in the protein level of the transcription factor STAT3 and in its phosphorylated form. In the presence of BZ, OCT lost the ability to reduce the phosphorylated protein levels. Finally, in primary cultures of human pituitary adenoma cells, BZ caused an increase in GH secretion. OCT decreased GH secretion, but the addition of BZ reversed the OCT effect. In conclusion, our results suggest that BZ may have an important role in the resistance of pituitary adenomas to the pharmacological treatment with somatostatin analogs.
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Affiliation(s)
- Valentina Zunino
- Department of Medical Sciences, University of Turin, I-10126, Turin, Italy
| | | | - Francesco Zenga
- Division of Neurosurgery, Città della Salute e della Scienza University Hospital, I-10126, Turin, Italy
| | - Federica Penner
- Division of Neurosurgery, Città della Salute e della Scienza University Hospital, I-10126, Turin, Italy
| | - Francesca Maletta
- Division of Pathology, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - Francesco Valerio
- Department of Medical Sciences, University of Turin, I-10126, Turin, Italy
| | - Letizia Rinella
- Department of Medical Sciences, University of Turin, I-10126, Turin, Italy
| | - Emanuela Arvat
- Department of Medical Sciences, University of Turin, I-10126, Turin, Italy; Division of Oncological Endocrinology, Città della Salute e della Scienza University Hospital, I-10126, Turin, Italy
| | - Nicoletta Fortunati
- Division of Oncological Endocrinology, Città della Salute e della Scienza University Hospital, I-10126, Turin, Italy.
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Molecular and Cellular Mechanisms Underlying Somatostatin-Based Signaling in Two Model Neural Networks, the Retina and the Hippocampus. Int J Mol Sci 2019; 20:ijms20102506. [PMID: 31117258 PMCID: PMC6566141 DOI: 10.3390/ijms20102506] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 02/06/2023] Open
Abstract
Neural inhibition plays a key role in determining the specific computational tasks of different brain circuitries. This functional "braking" activity is provided by inhibitory interneurons that use different neurochemicals for signaling. One of these substances, somatostatin, is found in several neural networks, raising questions about the significance of its widespread occurrence and usage. Here, we address this issue by analyzing the somatostatinergic system in two regions of the central nervous system: the retina and the hippocampus. By comparing the available information on these structures, we identify common motifs in the action of somatostatin that may explain its involvement in such diverse circuitries. The emerging concept is that somatostatin-based signaling, through conserved molecular and cellular mechanisms, allows neural networks to operate correctly.
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Memmert S, Damanaki A, Nokhbehsaim M, Nogueira AVB, Eick S, Cirelli JA, Jäger A, Deschner J. Regulation of somatostatin receptor 2 by proinflammatory, microbial and obesity-related signals in periodontal cells and tissues. Head Face Med 2019; 15:2. [PMID: 30609928 PMCID: PMC6319011 DOI: 10.1186/s13005-018-0185-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 12/04/2018] [Indexed: 12/18/2022] Open
Abstract
Background Periodontitis is a chronic disease characterized by a progressive and irreversible destruction of the tooth-supporting tissues, including gingiva and periodontal ligament (PDL). Microorganisms, such as Fusobacterium nucleatum, evoke an inflammatory host response, which leads to increased levels of inflammatory mediators, such as interleukin (IL)-1β. Periodontitis has been linked to obesity, and adipokines have been suggested to represent a pathomechanistic link. The hormone somatostatin (SST) exerts antiproliferative, antiangiogenetic, proapoptotic, anti-nociceptive and other effects through binding to its receptors, such as SSTR2. Therefore, the objective of the present study was to examine the regulation of SSTR2 in periodontal cells and tissues under inflammatory, microbial and obesity-related conditions. Methods In-vitro, human PDL fibroblasts were exposed to IL-1β, F. nucleatum, leptin or visfatin. The SSTR2 regulation was assessed by real-time PCR and immunocytochemistry. In-vivo, the SSTR2 expression was analyzed in gingival biopsies of periodontally diseased and healthy subjects by real-time PCR and immunohistochemistry. Additionally, the SSTR2 expression was determined in gingival biopsies of rats with ligature-induced periodontitis, rats with diet-induced obesity, and periodontally and systemically healthy control animals. For statistical analyses, the Mann-Whitney-U test and ANOVA with post-hoc tests were applied (p < 0.05). Results Exposure of PDL cells to IL-1β and F. nucleatum caused a significant SSTR2 upregulation by 2.6-fold and 6.4-fold, respectively. Additionally, leptin and visfatin increased significantly the SSTR2 gene expression by 3.0-fold and 2.8-fold, respectively. These stimulatory effects were also observed at protein level. SSTR2 expressions in human gingival biopsies from sites of periodontitis were significantly higher than those in healthy biopsies. Similarly, SSTR2 expression levels were significantly enhanced at periodontally-diseased sites in rat experimental periodontitis. Finally, the SSTR2 expression was significantly upregulated in gingival biopsies of obese rats as compared to normal weight control animals. Conclusions Our study provides original insights into the SSTR2 regulation in cells and tissues of the periodontium. We demonstrate for the first time that proinflammatory, microbial and obesity-associated molecules result in an SSTR2 upregulation. Since SST has been shown to be antiproliferative, antiangiogenetic, and proapoptotic, our study suggests that SSTR2 might play a critical role in the aetiopathogenesis of periodontitis.
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Affiliation(s)
- Svenja Memmert
- Department of Orthodontics, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Welschnonnenstr, 17 53111, Bonn, Germany. .,Section of Experimental Dento-Maxillo-Facial Medicine, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Bonn, Germany.
| | - Anna Damanaki
- Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Marjan Nokhbehsaim
- Section of Experimental Dento-Maxillo-Facial Medicine, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Bonn, Germany
| | - Andressa V B Nogueira
- Department of Diagnosis and Surgery, School of Dentistry at Araraquara, Sao Paulo State University, UNESP, Araraquara, Brazil
| | - Sigrun Eick
- Department of Periodontology, Laboratory for Oral Microbiology, zmk bern, Zahnmedizinische Kliniken, Bern, Switzerland
| | - Joni A Cirelli
- Department of Diagnosis and Surgery, School of Dentistry at Araraquara, Sao Paulo State University, UNESP, Araraquara, Brazil
| | - Andreas Jäger
- Department of Orthodontics, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Welschnonnenstr, 17 53111, Bonn, Germany
| | - James Deschner
- Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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de Vries LH, Lodewijk L, Willems SM, Dreijerink KMA, de Keizer B, van Diest PJ, Schepers A, Bonenkamp HJ, van Engen-van Grunsven IACH, Kruijff S, van Hemel BM, Links TP, Nieveen van Dijkum EJM, van Eeden S, Valk GD, Borel Rinkes IHM, Vriens MR. SSTR2A expression in medullary thyroid carcinoma is correlated with longer survival. Endocrine 2018; 62:639-647. [PMID: 30128959 PMCID: PMC6244936 DOI: 10.1007/s12020-018-1706-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/27/2018] [Indexed: 12/23/2022]
Abstract
PURPOSE Medullary thyroid carcinoma (MTC) derives from the parafollicular C-cells of the thyroid gland. Somatostatin receptors (SSTRs) are expressed in various neuroendocrine tumours including MTC. The aim of this study was to evaluate SSTR2A as a prognostic factor for MTC, to study distribution of SSTR2A expression within tumours and to compare expression of SSTR2A between primary tumours and corresponding lymph node metastases. METHODS Patients who underwent surgery between 1988 and 2014 for MTC from five tertiary referral centres in The Netherlands were included. In total, primary tumours of 114 patients and lymph node metastases of 34 patients were analysed for expression of SSTR2A using a tissue microarray, and correlated with clinicopathological variables and survival. RESULTS The mean age of patients was 45.5 years (SD 16.2), 55 patients were male (49.5%). Primary tumours of 58 patients (50.9%) showed SSTR2A expression. In multivariate Cox-regression analysis, SSTR2A positivity correlated independently with better overall survival (OS) (HR 0.3; 95% CI 0.1-1.0). In stage IV MTC patients, 10-year survival rates for SSTR2A-negative and positive patients were 43% and 96%, respectively. In 53.9% of patients with lymph node metastases, expression in primary tumour and lymph node metastases differed. CONCLUSION SSTR2A expression is correlated with longer OS in MTC, especially for stage IV patients, suggesting that SSTR2A expression might be a useful prognostic factor in MTC. The SSTR2A status of the primary MTC does not predict expression in lymph node metastases.
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Affiliation(s)
- Lisa H de Vries
- Department of Surgery, University Medical Centre Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | - Lutske Lodewijk
- Department of Surgery, University Medical Centre Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | - Stefan M Willems
- Department of Pathology, University Medical Centre Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | - Koen M A Dreijerink
- Department of Endocrine Oncology, University Medical Centre Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | - Bart de Keizer
- Department of Radiology, University Medical Centre Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | - Paul J van Diest
- Department of Pathology, University Medical Centre Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | - Abbey Schepers
- Department of Surgery, Leiden University Medical Centre, Albinusdreef 2, 2333ZA, Leiden, The Netherlands
| | - Han J Bonenkamp
- Department of Surgery, Radboud University Medical Centre, Geert Grooteplein 8, 6525GA, Nijmegen, The Netherlands
| | | | - Schelto Kruijff
- Department of Surgery, University Medical Centre Groningen, Hanzeplein 1, 9700RB, Groningen, The Netherlands
| | - Bettien M van Hemel
- Department of Pathology, University Medical Centre Groningen, Hanzeplein 1, 9700RB, Groningen, The Netherlands
| | - Thera P Links
- Department of Internal Medicine, University Medical Centre Groningen, Hanzeplein 1, 9700RB, Groningen, The Netherlands
| | - Els J M Nieveen van Dijkum
- Department of Surgery, Academic Medical Centre Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands
| | - Susanne van Eeden
- Department of Pathology, Academic Medical Centre Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands
| | - Gerlof D Valk
- Department of Endocrine Oncology, University Medical Centre Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | - Inne H M Borel Rinkes
- Department of Surgery, University Medical Centre Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | - Menno R Vriens
- Department of Surgery, University Medical Centre Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands.
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Chen X, Zhang XY, Shen Y, Fan LL, Ren ML, Wu YP. Synthetic paclitaxel-octreotide conjugate reversing the resistance of A2780/Taxol to paclitaxel in xenografted tumor in nude mice. Oncotarget 2018; 7:83451-83461. [PMID: 27825139 PMCID: PMC5347781 DOI: 10.18632/oncotarget.13120] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 10/12/2016] [Indexed: 12/11/2022] Open
Abstract
Peptide hormone-based targeted therapy to tumors has been studied extensively. Our previous study shows that somatostatin receptor expresses high level on drug-resistant human ovarian cancer. The paclitaxel-octreotide conjugate (POC) exhibits enhanced growth inhibition, as well as reduced toxicity, in paclitaxel-resistant human ovarian cancer cells. The aim of this study was to investigate the effect of targeted cytotoxicity and potential reversal mechanism of resistance in paclitaxel-resistant human ovarian cancer cells xenografted into nude mice. The SSTR2 shows higher expression levels in tumor tissue. Moreover, fluorescein-labeled POC displays favorable targeting in tumor cells. POC presents the perfect efficacy in inhibiting tumor growth and exerts lower or no toxic effects on normal tissues. Real-time PCR and Western Blotting has demonstrated that the mRNA and protein expressions of SSTR2 in POC group were significantly higher, while MDR1, α-tubulin, βIII-tubulin, VEGF and MMP-9 were significantly lower than in the other treatment groups and controls. Combined with the previous study in vitro, this study evaluates an effective approach on the treatment of paclitaxel-resistant ovarian cancer which expresses somatostatin receptor SSTR. Our investigation has also revealed the possible molecular mechanism of POC in treating the ovarian cancer, and therefore, provided a theoretical basis for the clinical application of this newly-invented compound.
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Affiliation(s)
- Xi Chen
- Department of Obstetrics and Gynaecology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing 210009, China
| | - Xiao-Yu Zhang
- Department of Obstetrics and Gynaecology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing 210009, China
| | - Yang Shen
- Department of Obstetrics and Gynaecology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing 210009, China
| | - Li-Li Fan
- Department of Obstetrics and Gynaecology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing 210009, China
| | - Mu-Lan Ren
- Department of Obstetrics and Gynaecology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing 210009, China
| | - Yong-Ping Wu
- Jiangsu Provincial Institute of Materia Medica, Nanjing 210009, China
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Amato R, Dal Monte M, Lulli M, Raffa V, Casini G. Nanoparticle-Mediated Delivery of Neuroprotective Substances for the Treatment of Diabetic Retinopathy. Curr Neuropharmacol 2018; 16:993-1003. [PMID: 28714394 PMCID: PMC6120116 DOI: 10.2174/1570159x15666170717115654] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 05/04/2017] [Accepted: 07/14/2017] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is a major complication of diabetes, characterized by extensive vascular pathology leading to vision loss. Neuronal suffering and death are also present in the diabetic retina as a result of different molecular mechanisms that are compromised or modified in response to high glucose. The aim of this paper is to highlight recent data indicating that neurodegeneration is likely to play a primary role in the development of DR and that strategies based on nanomedicine may be exploited to deliver neuroprotection to the retina. METHODS An extensive analysis of the publications dealing with the role of neuroprotection in DR and with nanoparticle-mediated drug delivery to the retina has been conducted using PubMed, with particular attention to the most recent papers. RESULTS There are important limitations related to possible systemic side effects of neuroprotective substances and to drug bioavailability in the retina such as, for instance, the amount of drug reaching the retina, the need of keeping to a minimum the number of administrations (especially, for example, in the case of intraocular injections) and the need of assuring a long-lasting, graded intraocular drug delivery. In recent years, a variety of investigations have been aimed at the exploitation of approaches of nanomedicine to enhance the pharmacokinetics and pharmacodynamic activity of intraocularly delivered drugs. In particular, we provide some preliminary results that we have obtained about the feasibility of delivering magnetic nanoparticles functionalized with a neuroprotectant to mouse eyes through intraocular injections. CONCLUSION We propose that nanoparticles functionalized with neuroprotective substances may be used to protect the diabetic retina, thus causing an impact in the design of future pharmacologic treatments for DR.
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Affiliation(s)
| | | | | | | | - Giovanni Casini
- Address correspondence to this author at the Department of Biology, University of Pisa, via S. Zeno 31, I-56127 Pisa, Italy; Tel: ++39-050-2211423; E-mail:
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18
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Wang J, Tian W, Wang S, Wei W, Wu D, Wang H, Wang L, Yang R, Ji A, Li Y. Anti-inflammatory and retinal protective effects of capsaicin on ischaemia-induced injuries through the release of endogenous somatostatin. Clin Exp Pharmacol Physiol 2017; 44:803-814. [PMID: 28429852 DOI: 10.1111/1440-1681.12769] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 03/31/2017] [Accepted: 04/15/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Jun Wang
- Henan University School of Medicine; Kaifeng China
| | - Wenke Tian
- Henan University School of Medicine; Kaifeng China
| | | | - Wenqiang Wei
- Henan University School of Medicine; Kaifeng China
| | - Dongdong Wu
- Henan University School of Medicine; Kaifeng China
| | | | - Li Wang
- The First Affiliated Hospital of Henan University; Kaifeng China
| | - Ruisheng Yang
- The First Affiliated Hospital of Henan University; Kaifeng China
| | - Ailing Ji
- Henan University School of Medicine; Kaifeng China
| | - Yanzhang Li
- Henan University School of Medicine; Kaifeng China
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19
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Li M, Wang S, Wang S, Zhang L, Wu D, Yang R, Ji A, Li Y, Wang J. Occludin downregulation in high glucose is regulated by SSTR 2 via the VEGF/NRP1/Akt signaling pathway in RF/6A cells. Exp Ther Med 2017; 14:1732-1738. [PMID: 28810643 DOI: 10.3892/etm.2017.4651] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 03/23/2017] [Indexed: 01/20/2023] Open
Abstract
Occludin is a tight junction protein that forms the permeability barrier, which is typically disturbed in ischemic associated diseases. The aim of the present study was to determine whether somatostatin receptor 2 (SSTR2) in RF/6A cells is involved in the modulation of the downregulation of occludin induced by high glucose, and to evaluate the implicated molecules. RF/6A cells were maintained in Dulbecco's modified Eagle medium and treated with 0 or 30 mM D-glucose. SSTR2 agonist octreotide (OCT), OCT with SSTR2 antagonist cycle-somatostatin (c-SOM) and neuropilin 1 (NRP1) inhibitor ATWLPPR, respectively, were administered to RF/6A cells under high glucose conditions. Cell apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling. Western blot analysis was used to detect the protein expression level of SSTR2, occludin, vascular endothelial growth factor (VEGF), protein kinase B (Akt), phosphorylated Akt (p-Akt), extracellular signal-related kinases (ERK) and p-ERK proteins. The amount of VEGF released was determined by ELISA. Notably, the level of occludin reduced significantly under high glucose conditions. The results indicated that the administration of OCT prevented the reduction of occludin induced by high glucose, and co-administration with c-SOM reversed the effect of OCT. Increased VEGF secretion and expression of VEGF, p-Akt and p-ERK in RF/6A cells induced by high glucose were inhibited by OCT. ATWLPPR also prevented the downregulation of occludin, but did not inhibit p-Akt and p-ERK levels under high glucose conditions. The current study concluded that the activation of SSTR2 prevents high glucose-induced occludin downregulation in RF/6A cells, and VEGF, NRP1, p-Akt and p-ERK were implicated in this process. The pharmacological effects of SSTR2 targeting to endothelium may be used to assess the role of resistance of permeability and anti-inflammation.
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Affiliation(s)
- Mengling Li
- Department of Physiology, Henan University School of Medicine, Kaifeng, Henan 475004, P.R. China
| | - Shuaiwei Wang
- Department of Physiology, Henan University School of Medicine, Kaifeng, Henan 475004, P.R. China
| | - Songjiang Wang
- Department of Physiology, Henan University School of Medicine, Kaifeng, Henan 475004, P.R. China
| | - Lei Zhang
- Department of Physiology, Henan University School of Medicine, Kaifeng, Henan 475004, P.R. China
| | - Dongdong Wu
- Department of Physiology, Henan University School of Medicine, Kaifeng, Henan 475004, P.R. China
| | - Ruisheng Yang
- Department of Clinical Laboratory, The First Affiliated Hospital of Henan University, Kaifeng, Henan 475001, P.R. China
| | - Ailing Ji
- Department of Physiology, Henan University School of Medicine, Kaifeng, Henan 475004, P.R. China
| | - Yanzhang Li
- Department of Physiology, Henan University School of Medicine, Kaifeng, Henan 475004, P.R. China
| | - Jun Wang
- Department of Physiology, Henan University School of Medicine, Kaifeng, Henan 475004, P.R. China
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Herac M, Niederle B, Raderer M, Krebs M, Kaserer K, Koperek O. Expression of somatostatin receptor 2A in medullary thyroid carcinoma is associated with lymph node metastasis. APMIS 2016; 124:839-45. [DOI: 10.1111/apm.12584] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 06/20/2016] [Indexed: 01/30/2023]
Affiliation(s)
- Merima Herac
- Clinical Institute of Pathology; Medical University of Vienna; Vienna Austria
| | - Bruno Niederle
- Section of Endocrine Surgery; Division of General Surgery; Department of Surgery; Medical University of Vienna; Vienna Austria
| | - Markus Raderer
- Department of Internal Medicine I; Division of Oncology; Medical University of Vienna; Vienna Austria
| | - Michael Krebs
- Department of Internal Medicine I; Division of Endocrinology and Metabolism; Medical University of Vienna; Vienna Austria
| | | | - Oskar Koperek
- Clinical Institute of Pathology; Medical University of Vienna; Vienna Austria
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21
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Dal Monte M, Casini G. Indirect blockade of vascular endothelial growth factor: the potential for eye disease therapy. EXPERT REVIEW OF OPHTHALMOLOGY 2016. [DOI: 10.1586/17469899.2016.1131609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Acetyl-11-keto-β-boswellic acid reduces retinal angiogenesis in a mouse model of oxygen-induced retinopathy. Exp Eye Res 2015; 135:67-80. [DOI: 10.1016/j.exer.2015.04.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 02/27/2015] [Accepted: 04/21/2015] [Indexed: 11/22/2022]
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23
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Alig SK, Stampnik Y, Pircher J, Rotter R, Gaitzsch E, Ribeiro A, Wörnle M, Krötz F, Mannell H. The tyrosine phosphatase SHP-1 regulates hypoxia inducible factor-1α (HIF-1α) protein levels in endothelial cells under hypoxia. PLoS One 2015; 10:e0121113. [PMID: 25799543 PMCID: PMC4370726 DOI: 10.1371/journal.pone.0121113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 01/28/2015] [Indexed: 12/12/2022] Open
Abstract
Introduction The tyrosine phosphatase SHP-1 negatively influences endothelial function, such as VEGF signaling and reactive oxygen species (ROS) formation, and has been shown to influence angiogenesis during tissue ischemia. In ischemic tissues, hypoxia induced angiogenesis is crucial for restoring oxygen supply. However, the exact mechanism how SHP-1 affects endothelial function during ischemia or hypoxia remains unclear. We performed in vitro endothelial cell culture experiments to characterize the role of SHP-1 during hypoxia. Results SHP-1 knock-down by specific antisense oligodesoxynucleotides (AS-Odn) increased cell growth as well as VEGF synthesis and secretion during 24 hours of hypoxia compared to control AS-Odn. This was prevented by HIF-1α inhibition (echinomycin and apigenin). SHP-1 knock-down as well as overexpression of a catalytically inactive SHP-1 (SHP-1 CS) further enhanced HIF-1α protein levels, whereas overexpression of a constitutively active SHP-1 (SHP-1 E74A) resulted in decreased HIF-1α levels during hypoxia, compared to wildtype SHP-1. Proteasome inhibition (MG132) returned HIF-1α levels to control or wildtype levels respectively in these cells. SHP-1 silencing did not alter HIF-1α mRNA levels. Finally, under hypoxic conditions SHP-1 knock-down enhanced intracellular endothelial reactive oxygen species (ROS) formation, as measured by oxidation of H2-DCF and DHE fluorescence. Conclusions SHP-1 decreases half-life of HIF-1α under hypoxic conditions resulting in decreased cell growth due to diminished VEGF synthesis and secretion. The regulatory effect of SHP-1 on HIF-1α stability may be mediated by inhibition of endothelial ROS formation stabilizing HIF-1α protein. These findings highlight the importance of SHP-1 in hypoxic signaling and its potential as therapeutic target in ischemic diseases.
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Affiliation(s)
- Stefan K. Alig
- Walter Brendel Centre of Experimental Medicine, University of Munich, Munich, Germany
- Department of Internal Medicine III, University of Munich, Munich, Germany
| | - Yvonn Stampnik
- Walter Brendel Centre of Experimental Medicine, University of Munich, Munich, Germany
| | - Joachim Pircher
- Walter Brendel Centre of Experimental Medicine, University of Munich, Munich, Germany
- Department of Internal Medicine I, University of Munich, Munich, Germany
| | - Raffaela Rotter
- Walter Brendel Centre of Experimental Medicine, University of Munich, Munich, Germany
| | - Erik Gaitzsch
- Walter Brendel Centre of Experimental Medicine, University of Munich, Munich, Germany
| | - Andrea Ribeiro
- Department of Internal Medicine IV, University of Munich, Munich, Germany
| | - Markus Wörnle
- Department of Internal Medicine IV, University of Munich, Munich, Germany
| | - Florian Krötz
- Interventional Cardiology, Starnberg Community Hospital, Starnberg, Germany
| | - Hanna Mannell
- Walter Brendel Centre of Experimental Medicine, University of Munich, Munich, Germany
- * E-mail:
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Wilson T, Omelchenko I, Foster S, Zhang Y, Shi X, Nuttall AL. JAK2/STAT3 inhibition attenuates noise-induced hearing loss. PLoS One 2014; 9:e108276. [PMID: 25275304 PMCID: PMC4183445 DOI: 10.1371/journal.pone.0108276] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 08/27/2014] [Indexed: 02/07/2023] Open
Abstract
Signal transducers and activators of transcription 3 (STAT3) is a stress responsive transcription factor that plays a key role in oxidative stress-mediated tissue injury. As reactive oxygen species (ROS) are a known source of damage to tissues of the inner ear following loud sound exposure, we examined the role of the Janus kinase 2 (JAK2)/STAT3 signaling pathway in noise induce hearing loss using the pathway specific inhibitor, JSI-124. Mice were exposed to a moderately damaging level of loud sound revealing the phosphorylation of STAT3 tyrosine 705 residues and nuclear localization in many cell types in the inner ear including the marginal cells of the stria vascularis, type II, III, and IV fibrocytes, spiral ganglion cells, and in the inner hair cells. Treatment of the mice with the JAK2/STAT3 inhibitor before noise exposure reduced levels of phosphorylated STAT3 Y705. We performed auditory brain stem response and distortion product otoacoustic emission measurements and found increased recovery of hearing sensitivity at two weeks after noise exposure with JAK2/STAT3 inhibition. Performance of cytocochleograms revealed improved outer hair cell survival in JSI-124 treated mice relative to control. Finally, JAK2/STAT3 inhibition reduced levels of ROS detected in outer hair cells at two hours post noise exposure. Together, these findings demonstrate that inhibiting the JAK2/STAT3 signaling pathway is protective against noise-induced cochlear tissue damage and loss of hearing sensitivity.
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MESH Headings
- Animals
- Cochlea/metabolism
- Cochlea/pathology
- Cochlea/physiopathology
- Epithelium/metabolism
- Evoked Potentials, Auditory, Brain Stem
- Gene Expression Regulation
- Hair Cells, Auditory/metabolism
- Hair Cells, Auditory/pathology
- Hearing Loss, Noise-Induced/metabolism
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/physiopathology
- Inflammation Mediators/metabolism
- Janus Kinase 2/antagonists & inhibitors
- Janus Kinase 2/metabolism
- Male
- Mice
- Otoacoustic Emissions, Spontaneous
- Phosphorylation
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reactive Oxygen Species/metabolism
- STAT3 Transcription Factor/antagonists & inhibitors
- STAT3 Transcription Factor/metabolism
- Signal Transduction
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Affiliation(s)
- Teresa Wilson
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Irina Omelchenko
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington, United States of America
| | - Sarah Foster
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Yuan Zhang
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Xiaorui Shi
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Alfred L. Nuttall
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, Oregon, United States of America
- Kresge Hearing Research Institute, The University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
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25
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The β-adrenergic system as a possible new target for pharmacologic treatment of neovascular retinal diseases. Prog Retin Eye Res 2014; 42:103-29. [DOI: 10.1016/j.preteyeres.2014.06.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/30/2014] [Accepted: 06/05/2014] [Indexed: 12/31/2022]
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26
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Hulse RP, Beazley-Long N, Hua J, Kennedy H, Prager J, Bevan H, Qiu Y, Fernandes ES, Gammons MV, Ballmer-Hofer K, Gittenberger de Groot AC, Churchill AJ, Harper SJ, Brain SD, Bates DO, Donaldson LF. Regulation of alternative VEGF-A mRNA splicing is a therapeutic target for analgesia. Neurobiol Dis 2014; 71:245-59. [PMID: 25151644 PMCID: PMC4194316 DOI: 10.1016/j.nbd.2014.08.012] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/29/2014] [Accepted: 08/06/2014] [Indexed: 12/02/2022] Open
Abstract
Vascular endothelial growth factor-A (VEGF-A) is best known as a key regulator of the formation of new blood vessels. Neutralization of VEGF-A with anti-VEGF therapy e.g. bevacizumab, can be painful, and this is hypothesized to result from a loss of VEGF-A-mediated neuroprotection. The multiple vegf-a gene products consist of two alternatively spliced families, typified by VEGF-A165a and VEGF-A165b (both contain 165 amino acids), both of which are neuroprotective. Under pathological conditions, such as in inflammation and cancer, the pro-angiogenic VEGF-A165a is upregulated and predominates over the VEGF-A165b isoform. We show here that in rats and mice VEGF-A165a and VEGF-A165b have opposing effects on pain, and that blocking the proximal splicing event – leading to the preferential expression of VEGF-A165b over VEGF165a – prevents pain in vivo. VEGF-A165a sensitizes peripheral nociceptive neurons through actions on VEGFR2 and a TRPV1-dependent mechanism, thus enhancing nociceptive signaling. VEGF-A165b blocks the effect of VEGF-A165a. After nerve injury, the endogenous balance of VEGF-A isoforms switches to greater expression of VEGF-Axxxa compared to VEGF-Axxxb, through an SRPK1-dependent pre-mRNA splicing mechanism. Pharmacological inhibition of SRPK1 after traumatic nerve injury selectively reduced VEGF-Axxxa expression and reversed associated neuropathic pain. Exogenous VEGF-A165b also ameliorated neuropathic pain. We conclude that the relative levels of alternatively spliced VEGF-A isoforms are critical for pain modulation under both normal conditions and in sensory neuropathy. Altering VEGF-Axxxa/VEGF-Axxxb balance by targeting alternative RNA splicing may be a new analgesic strategy. The different vegf-a splice variants, VEGF-A165a and VEGF-A165b have pro- and anti-nociceptive actions respectively. Pro-nociceptive actions of VEGF-A165a are dependent on TRPV1. Alternative pre-mRNA splicing underpins peripheral sensitization by VEGF-A isoforms in normal and neuropathic animals.
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Affiliation(s)
- R P Hulse
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK; Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK
| | - N Beazley-Long
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK; School of Life Sciences, The Medical School, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK
| | - J Hua
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - H Kennedy
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - J Prager
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - H Bevan
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - Y Qiu
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | | | - M V Gammons
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | | | | | - A J Churchill
- Clinical Sciences, University of Bristol, Bristol BS1 2LX, UK
| | - S J Harper
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - S D Brain
- King's College London, London SE1 9NH, UK
| | - D O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK.
| | - L F Donaldson
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK; School of Life Sciences, The Medical School, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK.
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27
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Hernández C, Simó-Servat O, Simó R. Somatostatin and diabetic retinopathy: current concepts and new therapeutic perspectives. Endocrine 2014; 46:209-14. [PMID: 24627166 DOI: 10.1007/s12020-014-0232-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 02/28/2014] [Indexed: 12/15/2022]
Abstract
Somatostatin (SST) is abundantly produced by the human retina, and the main source is the retinal pigment epithelium (RPE). SST exerts relevant functions in the retina (neuromodulation, angiostatic, and anti-permeability actions) by interacting with SST receptors (SSTR) that are also expressed in the retina. In the diabetic retina, a downregulation of SST production does exist. In this article, we give an overview of the mechanisms by which this deficit of SST participates in the main pathogenic mechanisms involved in diabetic retinopathy (DR): neurodegeneration, neovascularization, and vascular leakage. In view of the relevant SST functions in the retina and the reduction of SST production in the diabetic eye, SST replacement has been proposed as a new target for treatment of DR. This could be implemented by intravitreous injections of SST analogs or gene therapy, but this is an aggressive route for the early stages of DR. Since topical administration of SST has been effective in preventing retinal neurodegeneration in STZ-induced diabetic rats, it seems reasonable to test this new approach in humans. In this regard, the results of the ongoing clinical trial EUROCONDOR will provide useful information. In conclusion, SST is a natural neuroprotective and antiangiogenic factor synthesized by the retina which is downregulated in the diabetic eye and, therefore, its replacement seems a rational approach for treating DR. However, clinical trials will be needed to establish the exact position of targeting SST in the treatment of this disabling complication of diabetes.
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Affiliation(s)
- Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Pg. Vall d'Hebron 119-129.08035, Barcelona, Spain
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28
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Marquez BV, Ikotun OF, Parry JJ, Rogers BE, Meares CF, Lapi SE. Development of a Radiolabeled Irreversible Peptide Ligand for PET Imaging of Vascular Endothelial Growth Factor. J Nucl Med 2014; 55:1029-34. [PMID: 24732153 DOI: 10.2967/jnumed.113.130898] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 01/24/2014] [Indexed: 01/30/2023] Open
Abstract
UNLABELLED Imaging agents based on peptide probes have desirable pharmacokinetic properties provided that they have high affinities for their target in vivo. An approach to improve a peptide ligand's affinity for its target is to make this interaction covalent and irreversible. For this purpose, we evaluated a (64)Cu-labeled affinity peptide tag, (64)Cu-L19K-(5-fluoro-2,4-dinitrobenzene) ((64)Cu-L19K-FDNB), which binds covalently and irreversibly to vascular endothelial growth factor (VEGF) as a PET imaging agent. We compared the in vivo properties of (64)Cu-L19K-FDNB in VEGF-expressing tumor xenografts with its noncovalent binding analogs, (64)Cu-L19K-(2,4-dinitrophenyl) ((64)Cu-L19K-DNP) and (64)Cu-L19K. METHODS The L19K peptide (GGNECDIARMWEWECFERK-CONH2) was constructed with 1,4,7-triazacyclononane-1,4,7-triacetic acid at the N terminus for radiolabeling with (64)Cu with a polyethylene glycol spacer between peptide and chelate. 1,5-difluoro-2,4-dinitrobenzene was conjugated at the C-terminal lysine for cross-linking to VEGF, resulting in L19K-FDNB. (64)Cu-L19K-FDNB was assayed for covalent binding to VEGF in vitro. As a control, L19K was conjugated to 1-fluoro-2,4-dinitrobenzene, resulting in L19K-DNP. PET imaging and biodistribution studies of (64)Cu-L19K-FDNB, (64)Cu-L19K-DNP, and the native (64)Cu-L19K were compared in HCT-116 xenografts. Blocking studies of (64)Cu-L19K-FDNB was performed with a coinjection of excess unlabeled L19K-FDNB. RESULTS In vitro binding studies confirmed the covalent and irreversible binding of (64)Cu-L19K-FDNB to VEGF, whereas (64)Cu-L19K-DNP and (64)Cu-L19K did not bind covalently. PET imaging showed higher tumor uptake with (64)Cu-L19K-FDNB than with (64)Cu-L19K-DNP and (64)Cu-L19K, with mean standardized uptake values of 0.62 ± 0.05, 0.18 ± 0.06, and 0.34 ± 0.14, respectively, at 24 h after injection (P < 0.05), and 0.53 ± 0.05, 0.32 ± 0.14, and 0.30 ± 0.09, respectively, at 48 h after injection (P < 0.05). Blocking studies with (64)Cu-L19K-FDNB in the presence of excess unlabeled peptide showed a 53% reduction in tumor uptake at 48 h after injection. CONCLUSION In this proof-of-concept study, the use of a covalent binding peptide ligand against VEGF improves tracer accumulation at the tumor site in vivo, compared with its noncovalent binding peptide analogs. This technique is a promising tool to enhance the potency of peptide probes as imaging agents.
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Affiliation(s)
- Bernadette V Marquez
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri
| | - Oluwatayo F Ikotun
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri
| | - Jesse J Parry
- Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri; and
| | - Buck E Rogers
- Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri; and
| | - Claude F Meares
- Department of Chemistry, University of California, Davis, California
| | - Suzanne E Lapi
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri
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29
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Phenotypes and biomarkers of diabetic retinopathy. Prog Retin Eye Res 2014; 41:90-111. [PMID: 24680929 DOI: 10.1016/j.preteyeres.2014.03.003] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 03/11/2014] [Accepted: 03/18/2014] [Indexed: 12/15/2022]
Abstract
Diabetic retinopathy (DR) remains a major cause of blindness as the prevalence of diabetes is expected to approximately double globally between 2000 and 2030. DR progresses over time at different rates in different individuals with only a limited number developing significant vision loss due to the two major vision-threatening complications, clinically significant macular edema and proliferative retinopathy. Good metabolic control is important to prevent and delay progression, but whereas some patients escape vision loss even with poor control, others develop vision loss despite good metabolic control. Our research group has been able to identify three different DR phenotypes characterized by different dominant retinal alterations and different risks of progression to vision-threatening complications. Microaneurysm turnover has been validated as a prognostic biomarker of development of clinically significant macular edema, whereas subclinical macular edema identified by OCT and mfERG appear to be also good candidates as organ-specific biomarkers of DR. Hemoglobin A1c remains the only confirmed systemic prognostic biomarker of DR progression. The availability of biomarkers of DR progression and the identification of different phenotypes of DR with different risks for development of vision-threatening complications offers new perspectives for understanding DR and for its personalized management.
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30
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Chalabi M, Duluc C, Caron P, Vezzosi D, Guillermet-Guibert J, Pyronnet S, Bousquet C. Somatostatin analogs: does pharmacology impact antitumor efficacy? Trends Endocrinol Metab 2014; 25:115-27. [PMID: 24405892 DOI: 10.1016/j.tem.2013.11.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 11/05/2013] [Accepted: 11/15/2013] [Indexed: 01/17/2023]
Abstract
Somatostatin is an endogenous inhibitor of secretion and cell proliferation. These features render somatostatin a logical candidate for the management of neuroendocrine tumors that express somatostatin receptors. Synthetic somatostatin analogs (SSAs) have longer half-lives than somatostatin, but have similar activities, and are used for the treatment of these types of disorders. Interest has focused on novel multireceptor analogs with broader affinity to several of the five somatostatin receptors, thereby presenting putatively higher antitumor activities. Recent evidence indicates that SSAs cannot be considered mimics of native somatostatin in regulating signaling pathways downstream of receptors. Here we review this knowledge, discuss the concept of biased agonism, and highlight what considerations need to be taken into account for the optimal clinical use of SSAs.
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Affiliation(s)
- Mounira Chalabi
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche (UMR) 1037, Centre de Recherche en Cancérologie de Toulouse (CRCT), Equipe labellisée Ligue Contre le Cancer and Laboratoire d'Excellence Toulouse Cancer (TOUCAN), 31432 Toulouse, France; Université Toulouse III Paul Sabatier, 31062 Toulouse, France
| | - Camille Duluc
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche (UMR) 1037, Centre de Recherche en Cancérologie de Toulouse (CRCT), Equipe labellisée Ligue Contre le Cancer and Laboratoire d'Excellence Toulouse Cancer (TOUCAN), 31432 Toulouse, France; Université Toulouse III Paul Sabatier, 31062 Toulouse, France
| | - Philippe Caron
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche (UMR) 1037, Centre de Recherche en Cancérologie de Toulouse (CRCT), Equipe labellisée Ligue Contre le Cancer and Laboratoire d'Excellence Toulouse Cancer (TOUCAN), 31432 Toulouse, France; Université Toulouse III Paul Sabatier, 31062 Toulouse, France; Service d'Endocrinologie et Maladies Métaboliques, Pôle Cardio-Vasculaire et Métabolique, Centre Hospitalier Universitaire (CHU) Larrey, 31059 Toulouse, France
| | - Delphine Vezzosi
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche (UMR) 1037, Centre de Recherche en Cancérologie de Toulouse (CRCT), Equipe labellisée Ligue Contre le Cancer and Laboratoire d'Excellence Toulouse Cancer (TOUCAN), 31432 Toulouse, France; Université Toulouse III Paul Sabatier, 31062 Toulouse, France; Service d'Endocrinologie et Maladies Métaboliques, Pôle Cardio-Vasculaire et Métabolique, Centre Hospitalier Universitaire (CHU) Larrey, 31059 Toulouse, France
| | - Julie Guillermet-Guibert
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche (UMR) 1037, Centre de Recherche en Cancérologie de Toulouse (CRCT), Equipe labellisée Ligue Contre le Cancer and Laboratoire d'Excellence Toulouse Cancer (TOUCAN), 31432 Toulouse, France; Université Toulouse III Paul Sabatier, 31062 Toulouse, France
| | - Stéphane Pyronnet
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche (UMR) 1037, Centre de Recherche en Cancérologie de Toulouse (CRCT), Equipe labellisée Ligue Contre le Cancer and Laboratoire d'Excellence Toulouse Cancer (TOUCAN), 31432 Toulouse, France; Université Toulouse III Paul Sabatier, 31062 Toulouse, France
| | - Corinne Bousquet
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche (UMR) 1037, Centre de Recherche en Cancérologie de Toulouse (CRCT), Equipe labellisée Ligue Contre le Cancer and Laboratoire d'Excellence Toulouse Cancer (TOUCAN), 31432 Toulouse, France; Université Toulouse III Paul Sabatier, 31062 Toulouse, France.
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31
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D'Alessandro A, Cervia D, Catalani E, Gevi F, Zolla L, Casini G. Protective effects of the neuropeptides PACAP, substance P and the somatostatin analogue octreotide in retinal ischemia: a metabolomic analysis. MOLECULAR BIOSYSTEMS 2014; 10:1290-304. [PMID: 24514073 DOI: 10.1039/c3mb70362b] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ischemia is a primary cause of neuronal death in retinal diseases and the somatostatin subtype receptor 2 agonist octreotide (OCT) is known to decrease ischemia-induced retinal cell death. Using a recently optimized ex vivo mouse model of retinal ischemia, we tested the anti-ischemic potential of two additional neuropeptides, pituitary adenylate cyclase activating peptide (PACAP) and substance P (SP), and monitored the major changes occurring at the metabolic level. Metabolomics analyses were performed via fast HPLC online using a microTOF-Q MS instrument, a workflow that is increasingly becoming the gold standard in the field of metabolomics. The metabolomic approach allowed detection of the most significant alterations induced in the retina by ischemia and of the significance of the protective effects exerted by OCT, PACAP or SP. All treatments were shown to reduce ischemia-induced cell death, vascular endothelial growth factor over-expression and glutamate release. The metabolomic analysis showed that OCT and, to a lesser extent, also PACAP or SP, were able to counteract the ischemia-induced oxidative stress and to promote, with various efficacies, (i) decreased accumulation of glutamate and normalization of glutathione homeostasis; (ii) reduced build-up of α-ketoglutarate, which might serve as a substrate for the enhanced biosynthesis of glutamate in response to ischemia; (iii) reduced accumulation of peroxidized lipids and inflammatory mediators; (iv) the normalization of glycolytic fluxes and thus preventing the over-accumulation of lactate or either promoting the down-regulation of the glyoxalate anti-oxidant system; (v) a reduced metabolic shift from glycolysis towards the PPP or either a blockade at the non-oxidative phase of the PPP; and (vi) tuning down of purine metabolism. In addition, OCT seemed to stimulate nitric oxide production. None of the treatments was able to restore ATP production, although ATP reservoirs were partly replenished by OCT, PACAP or SP. These data indicate that, in addition to that of somatostatin, peptidergic systems such as those of PACAP and SP deserve attention in view of peptide-based therapies to treat ischemic retinal disorders.
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Affiliation(s)
- Angelo D'Alessandro
- Dipartimento di Scienze Ecologiche e Biologiche, Università della Tuscia, L.go dell'Università snc, I-01100 Viterbo, Italy.
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Simó R, Hernández C. Neurodegeneration in the diabetic eye: new insights and therapeutic perspectives. Trends Endocrinol Metab 2014; 25:23-33. [PMID: 24183659 DOI: 10.1016/j.tem.2013.09.005] [Citation(s) in RCA: 351] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 09/02/2013] [Accepted: 09/27/2013] [Indexed: 11/29/2022]
Abstract
Diabetic retinopathy (DR), one of the leading causes of preventable blindness, has been considered a microcirculatory disease of the retina. However, there is emerging evidence to suggest that retinal neurodegeneration is an early event in the pathogenesis of DR, which participates in the development of microvascular abnormalities. Therefore, the study of the underlying mechanisms leading to neurodegeneration and the identification of the mediators in the crosstalk between neurodegeneration and microangiopathy will be essential for the development of new therapeutic strategies. In this review, an updated discussion of the mechanisms involved in neurodegeneration, as well as the link between neurodegeneration and microangiopathy, is presented. Finally, the therapeutic implications and new perspectives based on identifying those patients with retinal neurodegeneration are given.
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Affiliation(s)
- Rafael Simó
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain.
| | - Cristina Hernández
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain
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33
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Perianes-Cachero A, Burgos-Ramos E, Puebla-Jiménez L, Canelles S, Frago L, Hervás-Aguilar A, de Frutos S, Toledo-Lobo M, Mela V, Viveros M, Argente J, Chowen J, Arilla-Ferreiro E, Barrios V. Acute up-regulation of the rat brain somatostatin receptor-effector system by leptin is related to activation of insulin signaling and may counteract central leptin actions. Neuroscience 2013; 252:289-301. [DOI: 10.1016/j.neuroscience.2013.08.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 08/07/2013] [Accepted: 08/12/2013] [Indexed: 11/28/2022]
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34
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Hernández C, García-Ramírez M, Corraliza L, Fernández-Carneado J, Farrera-Sinfreu J, Ponsati B, González-Rodríguez A, Valverde AM, Simó R. Topical administration of somatostatin prevents retinal neurodegeneration in experimental diabetes. Diabetes 2013; 62:2569-78. [PMID: 23474487 PMCID: PMC3712066 DOI: 10.2337/db12-0926] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Retinal neurodegeneration is an early event in the pathogenesis of diabetic retinopathy (DR). Somatostatin (SST) is an endogenous neuroprotective peptide that is downregulated in the diabetic eye. The aim of the study was to test the usefulness of topical administration of SST in preventing retinal neurodegeneration. For this purpose, rats with streptozotocin-induced diabetes mellitus (STZ-DM) were treated with either SST eye drops or vehicle for 15 days. Nondiabetic rats treated with vehicle served as a control group. Functional abnormalities were assessed by electroretinography (ERG), and neurodegeneration was assessed by measuring glial activation and the apoptotic rate. In addition, proapoptotic (FasL, Bid, and activation of caspase-8 and caspase-3) and survival signaling pathways (BclxL) were examined. Intraretinal concentrations of glutamate and its main transporter glutamate/aspartate transporter (GLAST) were also determined. Treatment with SST eye drops prevented ERG abnormalities, glial activation, apoptosis, and the misbalance between proapoptotic and survival signaling detected in STZ-DM rats. In addition, SST eye drops inhibited glutamate accumulation in the retina and GLAST downregulation induced by diabetes mellitus. We conclude that topical administration of SST has a potent effect in preventing retinal neurodegeneration induced by diabetes mellitus. In addition, our findings open up a new preventive pharmacological strategy targeted to early stages of DR.
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Affiliation(s)
- Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain.
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35
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Beta3-adrenergic receptors modulate vascular endothelial growth factor release in response to hypoxia through the nitric oxide pathway in mouse retinal explants. Naunyn Schmiedebergs Arch Pharmacol 2013; 386:269-78. [DOI: 10.1007/s00210-012-0828-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 12/13/2012] [Indexed: 12/20/2022]
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36
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Perianes-Cachero A, Burgos-Ramos E, Puebla-Jiménez L, Canelles S, Viveros MP, Mela V, Chowen JA, Argente J, Arilla-Ferreiro E, Barrios V. Leptin-induced downregulation of the rat hippocampal somatostatinergic system may potentiate its anorexigenic effects. Neurochem Int 2012; 61:1385-96. [PMID: 23073237 DOI: 10.1016/j.neuint.2012.09.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 09/24/2012] [Accepted: 09/30/2012] [Indexed: 10/27/2022]
Abstract
The learning and memory mechanisms in the hippocampus translate hormonal signals of energy balance into behavioral outcomes involved in the regulation of food intake. As leptin and its receptors are expressed in the hippocampus and somatostatin (SRIF), an orexigenic neuropeptide, may inhibit leptin-mediated suppression of food intake in other brain areas, we asked whether chronic leptin infusion induces changes in the hippocampal somatostatinergic system and whether these modifications are involved in leptin-mediated effects. We studied 18 male Wistar rats divided into three groups: controls (C), treated intracerebroventricularly (icv) with leptin (12 μg/day) for 14 days (L) and a pair-fed group (PF) that received the same amount of food consumed by the L group. Food restriction increased whereas leptin decreased the hippocampal SRIF receptor density, due to changes in SRIF receptor 2 protein levels. These changes in the PF group were concurrent with an increase of hippocampal G protein-coupled receptor kinase 2 protein levels and activation of Akt and cyclic AMP response element binding protein. The inhibitory effect of SRIF on adenylyl cyclase (AC) activity, however, was decreased in L rats, coincident with lower G inhibitory α3 and higher AC-I levels as well as signal transducer and activator of transcription factor 3 activation. In addition, 20 male Wistar rats were included to analyze whether the leptin antagonist L39A/D40A/F41A and the SRIF receptor agonist SMS 201-995 modify SRIF signaling and food intake, respectively. Administration of L39A/D40A/F41A reversed changes in SRIF signaling, whereas SMS 201-995 ameliorated food consumption in L. Altogether, these results suggest that increased somatostatinergic tone in PF rats may be a mechanism to improve the hippocampal orexigenic effects in a situation of metabolic demand, whereas down-regulation of this system in L rats may represent a mechanism to enhance the anorexigenic effects of leptin.
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Affiliation(s)
- Arancha Perianes-Cachero
- Neurobiochemistry Unit, Department of Biochemistry and Molecular Biology, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, E-28871 Madrid, Spain
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Protective role of somatostatin receptor 2 against retinal degeneration in response to hypoxia. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:481-94. [DOI: 10.1007/s00210-012-0735-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 01/25/2012] [Indexed: 12/20/2022]
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