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Cen LP, Ng TK, Liang JJ, Xu C, Zhuang X, Liu YF, Chen SL, Xu Y, Yang Q, Yuan XL, Qin YJ, Chan SO, Chen H, Zhang M, Schally AV, Pang CP. Agonist of growth hormone-releasing hormone enhances retinal ganglion cell protection induced by macrophages after optic nerve injury. Proc Natl Acad Sci U S A 2021; 118:e1920834118. [PMID: 34244423 PMCID: PMC8285901 DOI: 10.1073/pnas.1920834118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Optic neuropathies are leading causes of irreversible visual impairment and blindness, currently affecting more than 100 million people worldwide. Glaucoma is a group of optic neuropathies attributed to progressive degeneration of retinal ganglion cells (RGCs). We have previously demonstrated an increase in survival of RGCs by the activation of macrophages, whereas the inhibition of macrophages was involved in the alleviation on endotoxin-induced inflammation by antagonist of growth hormone-releasing hormone (GHRH). Herein, we hypothesized that GHRH receptor (GHRH-R) signaling could be involved in the survival of RGCs mediated by inflammation. We found the expression of GHRH-R in RGCs of adult rat retina. After optic nerve crush, subcutaneous application of GHRH agonist MR-409 or antagonist MIA-602 promoted the survival of RGCs. Both the GHRH agonist and antagonist increased the phosphorylation of Akt in the retina, but only agonist MR-409 promoted microglia activation in the retina. The antagonist MIA-602 reduced significantly the expression of inflammation-related genes Il1b, Il6, and Tnf Moreover, agonist MR-409 further enhanced the promotion of RGC survival by lens injury or zymosan-induced macrophage activation, whereas antagonist MIA-602 attenuated the enhancement in RGC survival. Our findings reveal the protective effect of agonistic analogs of GHRH on RGCs in rats after optic nerve injury and its additive effect to macrophage activation, indicating a therapeutic potential of GHRH agonists for the protection of RGCs against optic neuropathies especially in glaucoma.
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Affiliation(s)
- Ling-Ping Cen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Tsz Kin Ng
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
- Shantou University Medical College, 515041 Shantou, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Jia-Jian Liang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Ciyan Xu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Xi Zhuang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Yu-Fen Liu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
- Shantou University Medical College, 515041 Shantou, China
| | - Shao-Lang Chen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Yanxuan Xu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Qichen Yang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Xiang-Ling Yuan
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
- Shantou University Medical College, 515041 Shantou, China
| | - Yong Jie Qin
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital and Guangdong Academy of Medical Sciences, 510080 Guangzhou, China
| | - Sun On Chan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Haoyu Chen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Mingzhi Zhang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Andrew V Schally
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136;
- Division of Medical Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Division of Endocrinology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136
- Cancer Institute, Veterans Affairs Medical Center, Miami, FL 33125
| | - Chi Pui Pang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China;
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
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Pech-Pool S, Berumen LC, Martínez-Moreno CG, García-Alcocer G, Carranza M, Luna M, Arámburo C. Thyrotropin-Releasing Hormone (TRH) and Somatostatin (SST), but not Growth Hormone-Releasing Hormone (GHRH) nor Ghrelin (GHRL), Regulate Expression and Release of Immune Growth Hormone (GH) from Chicken Bursal B-Lymphocyte Cultures. Int J Mol Sci 2020; 21:ijms21041436. [PMID: 32093298 PMCID: PMC7073104 DOI: 10.3390/ijms21041436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/14/2020] [Accepted: 02/16/2020] [Indexed: 12/31/2022] Open
Abstract
It is known that growth hormone (GH) is expressed in immune cells, where it exerts immunomodulatory effects. However, the mechanisms of expression and release of GH in the immune system remain unclear. We analyzed the effect of growth hormone-releasing hormone (GHRH), thyrotropin-releasing hormone (TRH), ghrelin (GHRL), and somatostatin (SST) upon GH mRNA expression, intracellular and released GH, Ser133-phosphorylation of CREB (pCREBS133), intracellular Ca2+ levels, as well as B-cell activating factor (BAFF) mRNA expression in bursal B-lymphocytes (BBLs) cell cultures since several GH secretagogues, as well as their corresponding receptors (-R), are expressed in B-lymphocytes of several species. The expression of TRH/TRH-R, ghrelin/GHS-R1a, and SST/SST-Rs (Subtypes 1 to 5) was observed in BBLs by RT-PCR and immunocytochemistry (ICC), whereas GHRH/GHRH-R were absent in these cells. We found that TRH treatment significantly increased local GH mRNA expression and CREB phosphorylation. Conversely, SST decreased GH mRNA expression. Additionally, when added together, SST prevented TRH-induced GH mRNA expression, but no changes were observed in pCREBS133 levels. Furthermore, TRH stimulated GH release to the culture media, while SST increased the intracellular content of this hormone. Interestingly, SST inhibited TRH-induced GH release in a dose-dependent manner. The coaddition of TRH and SST decreased the intracellular content of GH. After 10 min. of incubation with either TRH or SST, the intracellular calcium levels significantly decreased, but they were increased at 60 min. However, the combined treatment with both peptides maintained the Ca2+ levels reduced up to 60-min. of incubation. On the other hand, BAFF cytokine mRNA expression was significantly increased by TRH administration. Altogether, our results suggest that TRH and SST are implicated in the regulation of GH expression and release in BBL cultures, which also involve changes in pCREBS133 and intracellular Ca2+ concentration. It is likely that TRH, SST, and GH exert autocrine/paracrine immunomodulatory actions and participate in the maturation of chicken BBLs.
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Affiliation(s)
- Santiago Pech-Pool
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico; (S.P.-P.); (M.C.)
- Posgrado en Ciencias Químico-Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico; (L.C.B.); (G.G.-A.)
| | - Laura C. Berumen
- Posgrado en Ciencias Químico-Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico; (L.C.B.); (G.G.-A.)
| | - Carlos G. Martínez-Moreno
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico; (S.P.-P.); (M.C.)
| | - Guadalupe García-Alcocer
- Posgrado en Ciencias Químico-Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico; (L.C.B.); (G.G.-A.)
| | - Martha Carranza
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico; (S.P.-P.); (M.C.)
| | - Maricela Luna
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico; (S.P.-P.); (M.C.)
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230, Mexico
- Correspondence: (M.L.); (C.A.); Tel.: +52-(55)-5623-4066 (M.L.); +52-(55)-5623-4065 (C.A.); Fax: +52-(55)-5623-4005 (M.L. & C.A.)
| | - Carlos Arámburo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico; (S.P.-P.); (M.C.)
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230, Mexico
- Correspondence: (M.L.); (C.A.); Tel.: +52-(55)-5623-4066 (M.L.); +52-(55)-5623-4065 (C.A.); Fax: +52-(55)-5623-4005 (M.L. & C.A.)
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Fleming T, Balderas-Márquez JE, Epardo D, Ávila-Mendoza J, Carranza M, Luna M, Harvey S, Arámburo C, Martínez-Moreno CG. Growth Hormone Neuroprotection Against Kainate Excitotoxicity in the Retina is Mediated by Notch/PTEN/Akt Signaling. Invest Ophthalmol Vis Sci 2020; 60:4532-4547. [PMID: 31675424 DOI: 10.1167/iovs.19-27473] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose In the retina, growth hormone (GH) promotes axonal growth, synaptic restoration, and protective actions against excitotoxicity. Notch signaling pathway is critical for neural development and participates in the retinal neuroregenerative process. We investigated the interaction of GH with Notch signaling pathway during its neuroprotective effect against excitotoxic damage in the chicken retina. Methods Kainate (KA) was used as excitotoxic agent and changes in the mRNA expression of several signaling markers were determined by qPCR. Also, changes in phosphorylation and immunoreactivity were determined by Western blotting. Histology and immunohistochemistry were performed for morphometric analysis. Overexpression of GH was performed in the quail neuroretinal-derived immortalized cell line (QNR/D) cell line. Exogenous GH was administered to retinal primary cell cultures to study the activation of signaling pathways. Results KA disrupted the retinal cytoarchitecture and induced significant cell loss in several retinal layers, but the coaddition of GH effectively prevented these adverse effects. We showed that GH upregulates the Notch signaling pathway during neuroprotection leading to phosphorylation of the PI3K/Akt signaling pathways through downregulation of PTEN. In contrast, cotreatment of GH with the Notch signaling inhibitor, DAPT, prevented its neuroprotective effect against KA. We identified binding sites in Notch1 and Notch2 genes for STAT5. Also, GH prevented Müller cell transdifferentiation and downregulated Sox2, FGF2, and PCNA after cotreatment with KA. Additionally, GH modified TNF receptors immunoreactivity suggesting anti-inflammatory actions. Conclusions Our data indicate that the neuroprotective effects of GH against KA injury in the retina are mediated through the regulation of Notch signaling. Additionally, anti-inflammatory and antiproliferative effects were observed.
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Affiliation(s)
- Thomas Fleming
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México.,Department of Physiology, University of Alberta, Edmonton, Canada
| | - Jerusa E Balderas-Márquez
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - David Epardo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - José Ávila-Mendoza
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States
| | - Martha Carranza
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Maricela Luna
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Steve Harvey
- Department of Physiology, University of Alberta, Edmonton, Canada
| | - Carlos Arámburo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Carlos G Martínez-Moreno
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
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Neuroprotective Peptides in Retinal Disease. J Clin Med 2019; 8:jcm8081146. [PMID: 31374938 PMCID: PMC6722704 DOI: 10.3390/jcm8081146] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 07/26/2019] [Accepted: 07/31/2019] [Indexed: 02/07/2023] Open
Abstract
In the pathogenesis of many disorders, neuronal death plays a key role. It is now assumed that neurodegeneration is caused by multiple and somewhat converging/overlapping death mechanisms, and that neurons are sensitive to unique death styles. In this respect, major advances in the knowledge of different types, mechanisms, and roles of neurodegeneration are crucial to restore the neuronal functions involved in neuroprotection. Several novel concepts have emerged recently, suggesting that the modulation of the neuropeptide system may provide an entirely new set of pharmacological approaches. Neuropeptides and their receptors are expressed widely in mammalian retinas, where they exert neuromodulatory functions including the processing of visual information. In multiple models of retinal diseases, different peptidergic substances play neuroprotective actions. Herein, we describe the novel advances on the protective roles of neuropeptides in the retina. In particular, we focus on the mechanisms by which peptides affect neuronal death/survival and the vascular lesions commonly associated with retinal neurodegenerative pathologies. The goal is to highlight the therapeutic potential of neuropeptide systems as neuroprotectants in retinal diseases.
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Schally AV, Zhang X, Cai R, Hare JM, Granata R, Bartoli M. Actions and Potential Therapeutic Applications of Growth Hormone-Releasing Hormone Agonists. Endocrinology 2019; 160:1600-1612. [PMID: 31070727 DOI: 10.1210/en.2019-00111] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/03/2019] [Indexed: 11/19/2022]
Abstract
In this article, we briefly review the identification of GHRH, provide an abridged overview of GHRH antagonists, and focus on studies with GHRH agonists. Potent GHRH agonists of JI and MR class were synthesized and evaluated biologically. Besides the induction of the release of pituitary GH, GHRH analogs promote cell proliferation and exert stimulatory effects on various tissues, which express GHRH receptors (GHRH-Rs). A large body of work shows that GHRH agonists, such as MR-409, improve pancreatic β-cell proliferation and metabolic functions and facilitate engraftment of islets after transplantation in rodents. Accordingly, GHRH agonists offer a new therapeutic approach to treating diabetes. Various studies demonstrate that GHRH agonists promote repair of cardiac tissue, producing improvement of ejection fraction and reduction of infarct size in rats, reduction of infarct scar in swine, and attenuation of cardiac hypertrophy in mice, suggesting clinical applications. The presence of GHRH-Rs in ocular tissues and neuroprotective effects of GHRH analogs in experimental diabetic retinopathy indicates their possible therapeutic applications for eye diseases. Other effects of GHRH agonists, include acceleration of wound healing, activation of immune cells, and action on the central nervous system. As GHRH might function as a growth factor, we examined effects of GHRH agonists on tumors. In vitro, GHRH agonists stimulate growth of human cancer cells and upregulate GHRH-Rs. However, in vivo, GHRH agonists inhibit growth of human cancers xenografted into nude mice and downregulate pituitary and tumoral GHRH-Rs. Therapeutic applications of GHRH analogs are discussed. The development of GHRH analogs should lead to their clinical use.
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Affiliation(s)
- Andrew V Schally
- Veterans Affairs Medical Center, Miami, Florida
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida
- Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida
| | - Xianyang Zhang
- Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, Florida
| | - Renzhi Cai
- Veterans Affairs Medical Center, Miami, Florida
| | - Joshua M Hare
- Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, Florida
| | - Riccarda Granata
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Manuela Bartoli
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, Georgia
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Expression of growth hormone and growth hormone receptor genes in human eye tissues. Exp Eye Res 2019; 181:61-71. [PMID: 30633923 DOI: 10.1016/j.exer.2019.01.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 12/27/2018] [Accepted: 01/07/2019] [Indexed: 11/23/2022]
Abstract
In humans, the polygenic growth hormone (GH) locus is located on chromosome 17 and contributes with three types of proteins: pituitary GH which consists of at least two isoforms one of 22 kDa and the other of 20 kDa, placental GH, which also exhibits isoforms, and chorionic somatomammotropin hormone (CSH). While pituitary GH results from the expression of the GH-1 (GH-N) gene, placental GH is produced by the expression of the GH-2 (GH-V) gene and CSH is contributed by expression of the CSH-1 and CSH-2 genes. The location where GH-1 is expressed is the anterior pituitary and the rest of the genes in the locus are expressed in placenta. On the other hand, expression and synthesis of GH in extra-pituitary tissues, including the eye, has been recently described. However, the physiological role of GH in the eye has not yet been elucidated, although a possible neuroprotective role has been hypothesized. Thus, we analyzed GH-1, GH-2, CSH1/2, Pit-1, GHR, GHRH, GHRHR, SST, SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5 to elucidate the expression and regulation of the GH locus in the human eye. Through qPCR analysis, we only found evidence of GH-1 expression in retina, choroid and trabecular meshwork; its transcript turned out to be the same as pituitary GH mRNA found in major species, and no splicing variants were detected. PIT1 was absent in all the ocular tissues implying an independent GH-1 expression mechanism. We found evidence of GHR in the cornea, choroid coat and retina. These results suggest autocrine and/or paracrine regulation, possibly exerted by GHRH and SSTs (since their mRNAs and receptors were found predominantly in retinal, choroidal and corneal tissues) since expression of both molecules was detected in different ocular tissues, as well as in the same tissues where GH-1 expression was confirmed. Our results add solid evidence about the existence of a regulatory local system for GH expression and release in the human eye.
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Pérez-Ibave DC, Rodríguez-Sánchez IP, Garza-Rodríguez ML, Pérez-Maya AA, Luna M, Arámburo C, Tsin A, Perry G, Mohamed-Noriega K, Mohamed-Noriega J, Cavazos-Adame H, Mohamed-Hamsho J, Barrera-Saldaña HA. Expression of growth hormone gene in the baboon eye. Exp Eye Res 2018; 169:157-169. [PMID: 29407222 DOI: 10.1016/j.exer.2018.01.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 12/24/2017] [Accepted: 01/05/2018] [Indexed: 12/28/2022]
Abstract
The human growth hormone (GH) locus is comprised by two GH (GH1 and GH2) genes and three chorionic somatomammotropin (CSH1, CSH2 and CSH-L) genes. While GH1 is expressed in the pituitary gland, the rest are expressed in the placenta. However, GH1 is also expressed in several extrapituitary tissues, including the eye. So to understand the role of this hormone in the eye we used the baboon (Papio hamadryas), that like humans has a multigenic GH locus; we set up to investigate the expression and regulation of GH locus in adult and fetal baboon ocular tissues. We searched in baboon ocular tissues the expression of GH1, GH2, CSH1/2, Pit1 (pituitary transcription factor 1), GHR (growth hormone receptor), GHRH (growth hormone releasing hormone), GHRHR (growth hormone releasing hormone receptor), SST (somatostatin), SSTR1 (somatostatin receptor 1), SSTR2 (somatostatin receptor 2), SSTR3 (somatostatin receptor 3), SSTR4 (somatostatin receptor 4), and SSTR5 (somatostatin receptor 5) mRNA transcripts and derived proteins, by qPCR and immunofluorescence assays, respectively. The transcripts found were characterized by cDNA cloning and sequencing, having found only the one belonging to GH1 gene, mainly in the retina/choroid tissues. Through immunofluorescence assays the presence of GH1 and GHR proteins was confirmed in several retinal cell layers. Among the possible neuroendocrine regulators that may control local GH1 expression are GHRH and SST, since their mRNAs and proteins were found mainly in the retina/choroid tissues, as well as their corresponding receptors (GHRH and SSTR1-SSTR5). None of the ocular tissues express Pit1, so gene expression of GH1 in baboon eye could be independent of Pit1. We conclude that to understand the regulation of GH in the human eye, the baboon offers a very good experimental model.
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Affiliation(s)
- Diana Cristina Pérez-Ibave
- Universidad Autónoma de Nuevo León, Hospital Universitario "Dr. José Eleuterio González", Servicio de Oncología, Monterrey, Nuevo León, 64460, México
| | - Irám Pablo Rodríguez-Sánchez
- Universidad Autónoma de Nuevo León, Facultad de Medicina, Departamento de Genética, Monterrey, Nuevo León, 64460, México
| | - María Lourdes Garza-Rodríguez
- Universidad Autónoma de Nuevo León, Facultad de Medicina, Departamento de Bioquímica y Medicina Molecular, Monterrey, Nuevo León, 64460, México
| | - Antonio Alí Pérez-Maya
- Universidad Autónoma de Nuevo León, Facultad de Medicina, Departamento de Bioquímica y Medicina Molecular, Monterrey, Nuevo León, 64460, México
| | - Maricela Luna
- Universidad Nacional Autónoma de México, Instituto de Neurobiología, Departamento de Neurobiología Celular y Molecular, Querétaro, Qro., 76230, México
| | - Carlos Arámburo
- Universidad Nacional Autónoma de México, Instituto de Neurobiología, Departamento de Neurobiología Celular y Molecular, Querétaro, Qro., 76230, México
| | - Andrew Tsin
- UTRGV, School of Medicine, Department of Biomedical Sciences, Edinburg, TX, 78541, USA
| | - George Perry
- University of Texas at San Antonio, Department of Biology, San Antonio, TX, 78249, USA
| | - Karim Mohamed-Noriega
- Universidad Autónoma de Nuevo León, Hospital Universitario "Dr. José Eleuterio González", Departamento de Oftalmología, Monterrey, Nuevo León, 64460, México
| | - Jibran Mohamed-Noriega
- Universidad Autónoma de Nuevo León, Hospital Universitario "Dr. José Eleuterio González", Departamento de Oftalmología, Monterrey, Nuevo León, 64460, México
| | - Humberto Cavazos-Adame
- Universidad Autónoma de Nuevo León, Hospital Universitario "Dr. José Eleuterio González", Departamento de Oftalmología, Monterrey, Nuevo León, 64460, México
| | - Jesús Mohamed-Hamsho
- Universidad Autónoma de Nuevo León, Hospital Universitario "Dr. José Eleuterio González", Departamento de Oftalmología, Monterrey, Nuevo León, 64460, México
| | - Hugo Alberto Barrera-Saldaña
- Universidad Autónoma de Nuevo León, Facultad de Medicina, Departamento de Bioquímica y Medicina Molecular, Monterrey, Nuevo León, 64460, México; Vitagénesis, SA. Edificio Vitaxentrum, Blvd. Puerta del Sol 1005, Colinas de San Jerónimo, Monterrey, Nuevo León, 64630, México.
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Protective effects of agonists of growth hormone-releasing hormone (GHRH) in early experimental diabetic retinopathy. Proc Natl Acad Sci U S A 2017; 114:13248-13253. [PMID: 29180438 PMCID: PMC5740669 DOI: 10.1073/pnas.1718592114] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The studies described here are relevant to the cure of diabetic retinopathy, a leading cause of blindness with currently limited therapeutic options. Here we provided evidence showing that agonists of growth hormone-releasing hormone (GHRH) can significantly diminish retinal neurovascular injury characterizing the early stages of diabetic retinopathy through antioxidant and anti-inflammatory effects. The results of the presented studies provide information on the potential therapeutic effects of GHRH agonists and shed light on the role of hypothalamic hormones in retinal physiology and their effect on visual disorders. In addition, our findings suggest protective effects of GHRH analogs in other disease conditions affecting retinal neuronal cells and, possibly, other nonretinal neurons. The potential therapeutic effects of agonistic analogs of growth hormone-releasing hormone (GHRH) and their mechanism of action were investigated in diabetic retinopathy (DR). Streptozotocin-induced diabetic rats (STZ-rats) were treated with 15 μg/kg GHRH agonist, MR-409, or GHRH antagonist, MIA-602. At the end of treatment, morphological and biochemical analyses assessed the effects of these compounds on retinal neurovascular injury induced by hyperglycemia. The expression levels of GHRH and its receptor (GHRH-R) measured by qPCR and Western blotting were significantly down-regulated in retinas of STZ-rats and in human diabetic retinas (postmortem) compared with their respective controls. Treatment of STZ-rats with the GHRH agonist, MR-409, prevented retinal morphological alteration induced by hyperglycemia, particularly preserving survival of retinal ganglion cells. The reverse, using the GHRH antagonist, MIA-602, resulted in worsening of retinal morphology and a significant alteration of the outer retinal layer. Explaining these results, we have found that MR-409 exerted antioxidant and anti-inflammatory effects in retinas of the treated rats, as shown by up-regulation of NRF-2-dependent gene expression and down-regulation of proinflammatory cytokines and adhesion molecules. MR-409 also significantly down-regulated the expression of vascular endothelial growth factor while increasing that of pigment epithelium-derived factor in diabetic retinas. These effects correlated with decreased vascular permeability. In summary, our findings suggest a neurovascular protective effect of GHRH analogs during the early stage of diabetic retinopathy through their antioxidant and anti-inflammatory properties.
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Harvey S, Martinez-Moreno CG. Growth hormone and ocular dysfunction: Endocrine, paracrine or autocrine etiologies? Growth Horm IGF Res 2016; 29:28-32. [PMID: 27082451 DOI: 10.1016/j.ghir.2016.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/17/2016] [Accepted: 03/21/2016] [Indexed: 02/01/2023]
Abstract
The eye is a target site for GH action and growth hormone has been implicated in diabetic retinopathy and other ocular dysfunctions. However, while this could reflect the hypersecretion of pituitary GH, the expression of the GH gene is now known to occur in ocular tissues and it could thus also reflect excess GH production within the eye itself. The possibility that ocular dysfunctions might arise from endocrine, autocrine or paracrine etiologies of GH overexpression is therefore the focus of this brief review.
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Affiliation(s)
- Steve Harvey
- Department of Physiology, University of Alberta, Edmonton T6H 2H7, Canada.
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Harvey S, Martínez-Moreno CG, Ávila-Mendoza J, Luna M, Arámburo C. Growth hormone in the eye: A comparative update. Gen Comp Endocrinol 2016; 234:81-7. [PMID: 26828817 DOI: 10.1016/j.ygcen.2016.01.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 01/25/2016] [Indexed: 01/03/2023]
Abstract
Comparative studies have previously established that the eye is an extrapituitary site of growth hormone (GH) production and action in fish, amphibia, birds and mammals. In this review more recent literature and original data in this field are considered.
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Affiliation(s)
- Steve Harvey
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada.
| | | | - José Ávila-Mendoza
- Departamento de Neurobiología, Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico
| | - Maricela Luna
- Departamento de Neurobiología, Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico
| | - Carlos Arámburo
- Departamento de Neurobiología, Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico
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Šarić B, Brzović Šarić V, Barberić M, Predović J, Rumenjak V, Cerovski B. Oxidative stress impact on growth hormone secretion in the eye. Croat Med J 2016; 56:326-33. [PMID: 26321025 PMCID: PMC4576746 DOI: 10.3325/cmj.2015.56.326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Aim To evaluate the influence of oxidative stress on extrapituitary growth hormone (GH) secretion in the eye and to analyze the interdependence between eye and serum GH levels under normal and hypoxic conditions. Methods Pars plana vitrectomy (PPV) was performed in 32 patients with developed proliferative diabetic retinopathy (PDR) and 49 non-diabetic controls, both of whom required this procedure as part of their regular treatment in the period from April 2013 to December 2014. During PPV, vitreous samples were taken and blood was simultaneously collected from the cubital vein. GH levels in serum and vitreous samples were measured by electrochemical luminescence assay. Oxidative stress was measured by enzyme-linked immunosorbent assay of advanced oxidation protein products (AOPP) and lipid hydroperoxide (LPO) in serum and vitreous. Results Serum AOPP levels were significantly higher than vitreous levels in both groups (P < 0.001 for each group) and LPO levels were significantly higher only in PDR group (P < 0.001). There was a significant positive correlation between serum and vitreous LPO levels in PDR group (r = 0.909; P < 0.001). Serum GH levels were significantly higher than vitreous levels in both groups (P < 0.001 for each group). Serum GH levels were significantly higher in PDR group than in controls (P = 0.012). Vitreous GH values were slightly higher in PDR group, but the difference was not significant. Conclusion Our study confirms that GH production in the eye is autonomous and independent of oxidative stress or pituitary GH influence.
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Affiliation(s)
- Borna Šarić
- Borna Šarić, Dobri dol 56, 10000 Zagreb, Croatia,
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Martinez-Moreno CG, Trudeau VL, Harvey S. Co-storage and secretion of growth hormone and secretoneurin in retinal ganglion cells. Gen Comp Endocrinol 2015; 220:124-32. [PMID: 25435278 DOI: 10.1016/j.ygcen.2014.11.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/14/2014] [Accepted: 11/17/2014] [Indexed: 10/24/2022]
Abstract
It is well established that growth hormone (GH) and granins are co-stored and co-secreted from pituitary somatotrophs. In this work we demonstrate for the first time that GH- and secretoneurin (SN) immunoreactivity (the secretogranin II (SgII) fragment) are similarly present in retinal ganglion cells (RGCs), which is an extrapituitary site of GH expression, and in quail QNR/D cells, which provide an experimental RGC model. The expression of SgII and chromogranin A in the pituitary gland, neuroretina and QNR/D cells was confirmed by RT-PCR analysis. Western blotting also showed that the SN-immunoreactivity in somatotrophs and QNR/D cells was associated with multiple protein bands (24, 35, 48, 72, 78, 93 and 148kDa) of which the 72kDa and 148kDa bands were most abundant. Secretoneurin was constitutively secreted from QNR/D cells as 35kDa and 37kDa proteins and unlike GH, was not increased by exogenous GH-releasing hormone (GHRH). Intracellular analysis by EM showed co-localization of GH and SN in cell bodies and neurites in QNR/D cells. This co-localization was associated with small dark bodies in the neurites. In addition, co-localization of GH and SNAP-25 in the cell surface of QNR/D's plasma membranes suggests GH-release involves specific vesicle-membrane recognition in QNR/D cells. As SN is a marker for secretory granules, GH secretion from RGCs is thus likely to be in secretory granules, as in somatotrophs.
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Affiliation(s)
| | - Vance L Trudeau
- Department of Biology, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Steve Harvey
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada.
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Lea RW, Dawson T, Martinez-Moreno CG, El-Abry N, Harvey S. Growth hormone and cancer: GH production and action in glioma? Gen Comp Endocrinol 2015; 220:119-23. [PMID: 26163024 DOI: 10.1016/j.ygcen.2015.06.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 06/02/2015] [Accepted: 06/03/2015] [Indexed: 11/16/2022]
Abstract
The hypersecretion of pituitary growth hormone (GH) is associated with an increased risk of cancer, while reducing pituitary GH signaling reduces this risk. Roles for pituitary GH in cancer are therefore well established. The expression of the GH gene is, however, not confined to the pituitary gland and it is now known to occur in many extrapituitary tissues, in which it has local autocrine or paracrine actions, rather than endocrine function. It is, for instance, expressed in cancers of the prostate, lung, skin, endometrium and colon. The oncogenicity of autocrine GH may also be greater than that induced by endocrine or exogenous GH, as higher concentrations of GHR antagonists are required to inhibit its actions. This may reflect the fact that autocrine GH is thought to act at intracellular receptors directly after synthesis, in compartments not readily accessible to endocrine (or exogenous) GH. The roles and actions of extrapituitary GH in cancer may therefore differ from those of pituitary GH. The possibility that GH may be expressed and act in glioma tumors was therefore examined by immunohistochemistry. These results demonstrate, for the first time, the presence of abundant GH- and GH receptor (GHR-) immunoreactivity in glioma, in which they were co-localized in cytoplasmic but not nuclear compartments. These results demonstrate that glioma differs from most cancers in lacking nuclear GHRs, but GH is nevertheless likely to have autocrine or paracrine actions in the induction and progression of glioma.
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Affiliation(s)
- Robert W Lea
- Brain Tumour North West, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK.
| | | | | | - Nasra El-Abry
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada
| | - Steve Harvey
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada
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