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Li N, Gao S, Gao S, Wang Y, Huang H, Wang J, Shen X. Knockdown of thioredoxin interacting protein in Müller cells attenuates photoreceptor apoptosis in streptozotocin-induced diabetic mouse model. Int J Biol Macromol 2024; 271:132731. [PMID: 38815945 DOI: 10.1016/j.ijbiomac.2024.132731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 04/28/2024] [Accepted: 05/16/2024] [Indexed: 06/01/2024]
Abstract
We explored the effect of inhibition of thioredoxin interacting protein (Txnip) on neuroprotection in Müller cells under high glucose. Wild-type (WT) and Txnip knockout (Txnip-/-) mice were used to establish a streptozotocin (STZ)-induced diabetes model and a Müller cells high glucose model. We detected BDNF expression and PI3K/AKT/CREB pathway activation levels in the retina and Müller cells of each group in vivo and in vitro experiments. The Txnip-/- STZ group showed higher expression of BDNF and phosphorylation of PI3K/AKT/CREB in retina, and less retinal photoreceptor apoptosis was observed in Txnip-/- diabetic group than in WT. After using an inhibitor of PI3K signaling pathway, BDNF expression was reduced; In vitro co-cultured with Müller cells in different groups, 661 W cells showed different situations, Txnip-/- Müller cells maximum downregulated Cleaved-caspase 3 expression in 661 W, accompanied by an increase in Bcl-2/Bax ratio. These findings indicate that inhibiting endogenous Txnip in mouse Müller cells can promote their expression and secretion of BDNF, thereby reducing HG induced photoreceptor apoptosis and having important neuroprotective effects on DR. The regulation of BDNF expression by Txnip may be achieved by activating the PI3K/AKT/CREB pathway. This study suggests that regulating Txnip may be a potential target for DR treatment.
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Affiliation(s)
- Na Li
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Shuang Gao
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Sha Gao
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yanuo Wang
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hanwen Huang
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jing Wang
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China.
| | - Xi Shen
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China.
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Li J, Chen K, Li X, Zhang X, Zhang L, Yang Q, Xia Y, Xie C, Wang X, Tong J, Shen Y. Mechanistic insights into the alterations and regulation of the AKT signaling pathway in diabetic retinopathy. Cell Death Discov 2023; 9:418. [PMID: 37978169 PMCID: PMC10656479 DOI: 10.1038/s41420-023-01717-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 11/05/2023] [Accepted: 11/08/2023] [Indexed: 11/19/2023] Open
Abstract
In the early stages of diabetic retinopathy (DR), diabetes-related hyperglycemia directly inhibits the AKT signaling pathway by increasing oxidative stress or inhibiting growth factor expression, which leads to retinal cell apoptosis, nerve proliferation and fundus microvascular disease. However, due to compensatory vascular hyperplasia in the late stage of DR, the vascular endothelial growth factor (VEGF)/phosphatidylinositol 3 kinase (PI3K)/AKT cascade is activated, resulting in opposite levels of AKT regulation compared with the early stage. Studies have shown that many factors, including insulin, insulin-like growth factor-1 (IGF-1), VEGF and others, can regulate the AKT pathway. Disruption of the insulin pathway decreases AKT activation. IGF-1 downregulation decreases the activation of AKT in DR, which abrogates the neuroprotective effect, upregulates VEGF expression and thus induces neovascularization. Although inhibiting VEGF is the main treatment for neovascularization in DR, excessive inhibition may lead to apoptosis in inner retinal neurons. AKT pathway substrates, including mammalian target of rapamycin (mTOR), forkhead box O (FOXO), glycogen synthase kinase-3 (GSK-3)/nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor kappa-B (NF-κB), are a research focus. mTOR inhibitors can delay or prevent retinal microangiopathy, whereas low mTOR activity can decrease retinal protein synthesis. Inactivated AKT fails to inhibit FOXO and thus causes apoptosis. The GSK-3/Nrf2 cascade regulates oxidation and inflammation in DR. NF-κB is activated in diabetic retinas and is involved in inflammation and apoptosis. Many pathways or vital activities, such as the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) and mitogen-activated protein kinase (MAPK) signaling pathways, interact with the AKT pathway to influence DR development. Numerous regulatory methods can simultaneously impact the AKT pathway and other pathways, and it is essential to consider both the connections and interactions between these pathways. In this review, we summarize changes in the AKT signaling pathway in DR and targeted drugs based on these potential sites.
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Affiliation(s)
- Jiayuan Li
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
- Department of Cardiology, The Second Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Kuangqi Chen
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiang Li
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Xuhong Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Liyue Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Qianjie Yang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Yutong Xia
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Chen Xie
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiawei Wang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianping Tong
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China.
| | - Ye Shen
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China.
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Wu S, Mo X. Optic Nerve Regeneration in Diabetic Retinopathy: Potentials and Challenges Ahead. Int J Mol Sci 2023; 24:ijms24021447. [PMID: 36674963 PMCID: PMC9865663 DOI: 10.3390/ijms24021447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/31/2022] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Diabetic retinopathy (DR), the most common microvascular compilation of diabetes, is the leading cause of vision loss and blindness worldwide. Recent studies indicate that retinal neuron impairment occurs before any noticeable vascular changes in DR, and retinal ganglion cell (RGC) degeneration is one of the earliest signs. Axons of RGCs have little capacity to regenerate after injury, clinically leading the visual functional defects to become irreversible. In the past two decades, tremendous progress has been achieved to enable RGC axon regeneration in animal models of optic nerve injury, which holds promise for neural repair and visual restoration in DR. This review summarizes these advances and discusses the potential and challenges for developing optic nerve regeneration strategies treating DR.
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Affiliation(s)
| | - Xiaofen Mo
- Correspondence: ; Tel.: +86-021-64377134
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Insulin-like growth factor-1 stimulates retinal cell proliferation via activation of multiple signaling pathways. CURRENT RESEARCH IN NEUROBIOLOGY 2022; 4:100068. [PMID: 36589675 PMCID: PMC9800307 DOI: 10.1016/j.crneur.2022.100068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 09/05/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Insulin-like growth factor-1 (IGF-1) plays critical roles in the development of the central nervous system (CNS), including the retina, regulating cell proliferation, differentiation, and survival. Here, we investigated the role of IGF-1 on retinal cell proliferation using primary cultures from rat neural retina. Our data show that IGF-1 stimulates retinal cell proliferation and regulates the expression of neurotrophic factors, such as interleukin-4 and brain-derived neurotrophic factor. In addition, our results indicates that IGF-1-induced retinal cell proliferation requires activation of multiple signaling pathways, including phosphatidylinositol 3-kinase, protein kinase Src, phospholipase-C, protein kinase C delta, and mitogen-activated protein kinase pathways. We further show that activation of matrix metalloproteinases and epidermal growth factor receptor is also necessary for IGF-1 enhancing retinal cell proliferation. Overall, these results unveil potential mechanisms by which IGF-1 ensures retinal cell proliferation and support the notion that manipulation of IGF-1 signaling may be beneficial in CNS disorders associated with abnormal cell proliferation.
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Zhu M, Gao S, Gao S, Wang Y, Li N, Shen X. Interleukin-17A attenuates photoreceptor cell apoptosis in streptozotocin-induced diabetic mouse model. Bioengineered 2022; 13:14175-14187. [PMID: 35730427 PMCID: PMC9342149 DOI: 10.1080/21655979.2022.2084241] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Diabetic retinopathy (DR) represents an important microvascular complication of diabetes, which is the top etiology of vision impairment worldwide. Although interleukin (IL)-17A is increasingly implicated in DR development, the underlying cellular mechanisms remain poorly defined. This work aims to evaluate IL-17A levels in the retina of streptozotocin (STZ)-induced diabetic mice and elucidate their potential roles. We found IL-17A was upregulated in diabetic retina after intraperitoneal injection of STZ and high-glucose (HG)-cultured primary Müller cells. IL-17A knockout (IL-17A−/−) downregulated glial fibrillary acidic protein (GFAP) and inhibited the conversion of proneurotrophin-3 (proNT-3) to mature NT-3 in retinal specimens from diabetic mice as well as in Müller cells cultured under HG conditions. Induced apoptosis and upregulated Bax and cleaved caspase-3 were observed in retinal specimens from IL-17A−/− diabetic mice and photoreceptor (661 W) cells after co-culture with IL-17A−/− Müller cells. Moreover, RNA interference-induced gene silencing of tyrosine kinase C receptor (TrkC) in 661 W cells reversed the anti-apoptotic effect of IL-17A under HG conditions. Taken together, our findings suggest that IL-17A/NT-3/TrkC axis regulation suppresses apoptosis in photoreceptor cells, providing a new treatment strategy for DR.
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Affiliation(s)
- Minqi Zhu
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Shuang Gao
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Sha Gao
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yanuo Wang
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Na Li
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xi Shen
- Department of Ophthalmology, Ruijin Hospital, Affiliated Shanghai Jiaotong University School of Medicine, Shanghai, China
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Zheng Y, Sun Q, Xu X, Wang W. Novel peptide derived from IGF-2 displays anti-angiogenic activity in vitro and inhibits retinal angiogenesis in a model of oxygen-induced retinopathy. Clin Exp Ophthalmol 2020; 48:1261-1275. [PMID: 33026147 DOI: 10.1111/ceo.13864] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 09/11/2020] [Accepted: 09/16/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Retinopathy of prematurity (ROP), a major cause of significant visual morbidity and blindness in preterm infants, is closely related to pathological angiogenesis. The aim of the study is to evaluate the effect of a new 12-aa peptide (named peptide CW-703) from human insulin-like growth factor-2, against angiogenesis in ROP. METHODS In order to evaluate the inhibitory effect of CW-703 on the proliferation, migration, tube formation and apoptosis of human umbilical vein endothelial cells (ScienCell) in vitro, we used MTS assays, a modified Boyden chamber, Matrigel system and TUNEL assays. Effects in vivo were assayed using chorioallantoic membrane assays and oxygen-induced retinopathy (OIR) models in mice. We also performed eletrophysiological and histologic examinations to evaluate the possible toxicity of the peptide. Real-time PCR, ELISA and western blotting were used to elucidate the mechanism of CW-703. RESULTS CW-703 inhibited angiogenesis in vitro by suppressing endothelial cell proliferation, migration and tube formation. CW-703 also prevented angiogenesis in chicken chorioallantoic membrane assays and OIR assays in mice. No evident functional or morphologic abnormalities in neuroretina after CW-703 injection were revealed in electrophysiological tests and histological examinations. Moreover, we elucidated that CW-703 competed for binding to IGF-1R and inhibited angiogenesis by inhibiting IGF-1R/PI3K/AKT activation and downregulating vascular endothelial growth factor expression. CONCLUSION The novel peptide CW-703 may act as an effective inhibitor of ocular pathologic angiogenesis, especially in treating ROP.
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Affiliation(s)
- Ying Zheng
- Department of Ophthalmology, Shanghai General Hospital affiliated to Shanghai Jiaotong University, Shanghai, China
| | - Qiao Sun
- Department of Ophthalmology, Shanghai General Hospital affiliated to Shanghai Jiaotong University, Shanghai, China
| | - Xun Xu
- Department of Ophthalmology, Shanghai General Hospital affiliated to Shanghai Jiaotong University, Shanghai, China
| | - Weijun Wang
- Department of Ophthalmology, Shanghai General Hospital affiliated to Shanghai Jiaotong University, Shanghai, China
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EARLY MICROVASCULAR AND NEURAL CHANGES IN PATIENTS WITH TYPE 1 AND TYPE 2 DIABETES MELLITUS WITHOUT CLINICAL SIGNS OF DIABETIC RETINOPATHY. Retina 2020; 39:435-445. [PMID: 29206758 DOI: 10.1097/iae.0000000000001990] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE To assess and compare early modifications in inner retinal layer thickness and optical coherence tomography angiography parameters in patients with diabetes mellitus (DM) Types 1 and 2 without clinical signs of diabetic retinopathy. METHODS Ninety eyes of 90 subjects (24 Type 1 DM, 36 Type 2 DM, and 30 healthy controls) were prospectively evaluated with spectral domain OCT, swept-source OCT angiography, and color fundus photography (on the same day). Retinal nerve fiber layer, ganglion cell layer (GCL+), and nerve fiber layer + GCL+ (GCL++) thickness were automatically determined by the instrument in the 1, 3, and 6 central mm. On OCT angiography, the following parameters were evaluated: area of foveal avascular zone, number of focally dilated endings of the capillaries (detected only on OCT angiography), presence of regular/irregular foveal avascular zone, capillary loss, and capillary network irregularities in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). RESULTS Ganglion cell layer+ (P = 0.0099) and GCL++ (P = 0.0367) were significantly thicker in DM Type 1 versus DM Type 2 in 1 central mm, after adjustment for age and DM duration. The area of foveal avascular zone was significantly larger in DM Type 1 versus controls in both SCP and DCP and in DM Type 1 versus Type 2 only in DCP (P < 0.05 for all); the number of focally dilated endings of the capillaries was higher in DM Type 1 versus controls in both SCP and DCP (P < 0.01 for all); and in DM Type 2 versus controls only in DCP (P = 0.007). Perifoveal capillary loss in SCP and inner retinal layer thickness had the highest correlation in both DM types. CONCLUSION There are specific neural and microvascular modifications even before clinical signs of diabetic retinopathy in DM Types 1 and 2. Perifoveal capillary loss in the SCP is highly correlated with inner retinal layer. These data may help in characterization of patients at the preclinical stage of diabetic retinopathy.
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Zhang Y, Yan N, Wang X, Chang Y, Wang Y. MiR-129-5p regulates cell proliferation and apoptosis via IGF-1R/Src/ERK/Egr-1 pathway in RA-fibroblast-like synoviocytes. Biosci Rep 2019; 39:BSR20192009. [PMID: 31661546 PMCID: PMC6893169 DOI: 10.1042/bsr20192009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/13/2019] [Accepted: 10/22/2019] [Indexed: 02/07/2023] Open
Abstract
It is reported that miR-129-5p plays an important role in various diseases, but its effect on rheumatoid arthritis (RA) and the potential mechanism remain to be clarified. In the present research, we aimed to investigate the effect of miR-129-5p on RA and the special molecular mechanism. First, the expression of miR-129-5p was analyzed in RA patients and RA Fibroblast-like synoviocytes (RA-FLSs) by RT-PCR assay. The cell viability, apoptotic rate and the relative expression of caspase-3 and caspase-8 were measured by CCK-8, Annexin-FITC/propidium iodide (PI) and ELISA, respectively. Luciferase reporter assay was performed to investigate the target of miR-129-5p. The results revealed that the expression of miR-129-5p was down-regulated in RA patients and RA-FLSs. In addition, miR-129-5p inhibited cell proliferation and induced apoptosis of RA-FLS. Furthermore, luciferase reporter assay demonstrated that insulin-like growth factor-1 receptor (IGF-1R) was the direct target of miR-129-5p, and IGF-1R promoted cell proliferation and inhibited apoptosis by activating Src/ERK/Egr-1 signaling. Furthermoremore, the Src/ERK/Egr-1 signaling pathway was suppressed by miR-129-5p. Collectively, the results of the present study suggested that miR-129-5p regulated cell proliferation and apoptosis via IGF-1R/Src/ERK/Egr-1 signaling pathway in RA.
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Affiliation(s)
- Yan Zhang
- Department of Endocrinology, Shaanxi Provincial People’s Hospital, Xi’an 710068, China
| | - Ni Yan
- Department of Endocrinology, Shaanxi Provincial People’s Hospital, Xi’an 710068, China
| | - Xiaoqing Wang
- Outpatient Office, Shaanxi Provincial People’s Hospital, Xi’an 710068, China
| | - Yanhai Chang
- Department of Orthopaedics, Shaanxi Provincial People’s Hospital, Xi’an 710068, China
| | - Yu Wang
- Department of Orthopaedics, Xi’an Central Hospital, Xi’an 710003, China
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Gholami S, Kamali Y, Reza Rostamzad M. Glycine Supplementation Ameliorates Retinal Neuronal Damage in an Experimental Model of Diabetes in Rats: A Light and Electron Microscopic Study. J Ophthalmic Vis Res 2019; 14:448-456. [PMID: 31875100 PMCID: PMC6825695 DOI: 10.18502/jovr.v14i4.5449] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 06/15/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the potential neuroprotective effect of glycine supplementation on the retinal ultrastructure of streptozocin (STZ)-induced diabetic rats. Methods Adult male Wistar rats weighing 200–250 g (n = 40) were randomly divided into four groups of 10 each: normal group (C), glycine + normal group (G), STZ group (D), and glycine + STZ group (DG). The G and DG groups received glycine (130 mM and 1% w/v) freely in their drinking water seven days after the induction of diabetes for up to 16 weeks. Retinal samples for histopathology were examined using light and electron microscopy. Results Diabetes-induced histological changes were attenuated in the retinas of rats in the DG group. The ultrastructural alterations produced by experimental diabetes in the inner nuclear layer, outer nuclear layer, and ganglion cell layer were significantly ameliorated by glycine supplementation. Conclusion Our findings suggest that glycine supplementation effectively attenuates retinal neuronal damage in experimental diabetic rats, and thus may be a potential candidate to protect retinal ultrastructure against diabetes.
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Affiliation(s)
- Soghra Gholami
- Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Younes Kamali
- Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Mohammad Reza Rostamzad
- Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, International Division, Shiraz, Iran
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IGF-1 and IGF-1R modulate the effects of IL-4 on retinal ganglion cells survival: The involvement of M1 muscarinic receptor. Biochem Biophys Res Commun 2019; 519:53-60. [PMID: 31474338 DOI: 10.1016/j.bbrc.2019.08.124] [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: 08/01/2019] [Accepted: 08/23/2019] [Indexed: 11/22/2022]
Abstract
Trophic factors are involved in different cellular responses. Previously we demonstrated that IL-4 treatment induces an increase in retinal ganglion cell survival (RGCS) and regulates cholinergic differentiation of retinal cells in vitro. Data from literature show that IGF-1 also promotes RGCS, an effect mediated by PI-3K/AKT pathway. The aim of this study was to investigate the role of IGF-1 and IGF-1R on RGCS mediated by IL-4 treatment and the role of M1 acetylcholine receptors in this effect. Here we show that the effect of IL-4 on RGCS depends on IGF-1 and IGF-1R activation, the PI-3K/AKT and NFkB intracellular pathways and depends on M1 mAChRs activation. IGF-1 increases the levels of M1 mAChRs in 15min, 45min, 24 h and 48 h in mixed retinal cells culture, modulates the levels of IL-4, pIGF-1R, IGF-1R. IL-4 modulates IGF-1, pIGF-1R and IGF-1R levels in different time intervals. These results put in evidence a crosstalk between IL-4 and IGF-1 and a role of M1 mAChRs, IGF-1 and IGF-1R in RGCS mediated by IL-4.
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Ho MT, Teal CJ, Shoichet MS. A hyaluronan/methylcellulose-based hydrogel for local cell and biomolecule delivery to the central nervous system. Brain Res Bull 2019; 148:46-54. [PMID: 30898580 DOI: 10.1016/j.brainresbull.2019.03.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/01/2019] [Accepted: 03/12/2019] [Indexed: 02/03/2023]
Abstract
Regenerative medicine strategies rely on exogenous cell transplantation and/or endogenous cell stimulation. Biomaterials can help to increase the regenerative potential of cells and biomolecules by controlling transplanted cell fate and provide a local, sustained release of biomolecules. In this review, we describe the use of a hyaluronan/methylcellulose (HAMC)-based hydrogel as a delivery vehicle to the brain, spinal cord, and retina to promote cellular survival and tissue repair. We discuss various controlled release strategies to prolong the delivery of factors for neuroprotection. The versatility of this hydrogel for a diversity of applications highlights its potential to enhance cell- and biomolecule-based treatment strategies.
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Affiliation(s)
- Margaret T Ho
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada; Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
| | - Carter J Teal
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada; Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
| | - Molly S Shoichet
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada; Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada; Department of Chemistry, University of Toronto, Toronto, Canada.
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Zafar S, Sachdeva M, Frankfort BJ, Channa R. Retinal Neurodegeneration as an Early Manifestation of Diabetic Eye Disease and Potential Neuroprotective Therapies. Curr Diab Rep 2019; 19:17. [PMID: 30806815 PMCID: PMC7192364 DOI: 10.1007/s11892-019-1134-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW Diabetic retinopathy (DR) is a major cause of visual impairment and blindness throughout the world. Microvascular changes have long been regarded central to disease pathogenesis. In recent years, however, retinal neurodegeneration is increasingly being hypothesized to occur prior to the vascular changes classically associated with DR and contribute to disease pathogenesis. RECENT FINDINGS There is growing structural and functional evidence from human and animal studies that suggests retinal neurodegeneration to be an early component of DR. Identification of new therapeutic targets is an ongoing area of research with several different molecules undergoing testing in animal models for their neuroprotective properties and for possible use in humans. Retinal neurodegeneration may play a central role in DR pathogenesis. As new therapies are developed, it will be important to develop criteria for clinically defining retinal neurodegeneration. A standardization of the methods for monitoring neurodegeneration along with more sensitive means of detecting preclinical damage is also needed.
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Affiliation(s)
- Sidra Zafar
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA
| | - Mira Sachdeva
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA
| | | | - Roomasa Channa
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
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He H, Weir RL, Toutounchian JJ, Pagadala J, Steinle JJ, Baudry J, Miller DD, Yates CR. The quinic acid derivative KZ-41 prevents glucose-induced caspase-3 activation in retinal endothelial cells through an IGF-1 receptor dependent mechanism. PLoS One 2017; 12:e0180808. [PMID: 28796787 PMCID: PMC5552119 DOI: 10.1371/journal.pone.0180808] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/21/2017] [Indexed: 12/03/2022] Open
Abstract
Retinal microaneurysms, an early disease manifestation of diabetic retinopathy, are associated with retinal endothelial cell (REC) death and macular edema. We previously demonstrated that a quinic acid (QA) analog, KZ-41, promoted REC survival by blunting stress-induced p38 MAPK activation. Herein, we sought to expand our understanding of the pro-survival signal transduction pathways actuated by KZ-41. Using human RECs exposed to high glucose (25 mM, 72 hours), we demonstrated that KZ-41 blocks caspase-3 activation by triggering phosphorylation of the PI3K regulatory subunit (p85; Tyr458) and its downstream target Akt (Ser473). Akt signal transduction was accompanied by autophosphorylation of the receptor tyrosine kinase, insulin growth factor-1 receptor (IGF-1R). IGF-1R knockdown using either the tyrosine kinase inhibitor AG1024 or silencing RNA abolished KZ-41’s pro-survival effect. Under high glucose stress, caspase-3 activation correlated with elevated ERK1/2 phosphorylation and decreased insulin receptor substrate-1 (IRS-1) levels. KZ-41 decreased ERK1/2 phosphorylation and reversed the glucose-dependent reduction in IRS-1. To gain insight into the mechanistic basis for IGF-1R activation by KZ-41, we used molecular modeling and docking simulations to explore a possible protein:ligand interaction between the IGF-1R kinase domain and KZ-41. Computational investigations suggest two possible KZ-41 binding sites within the kinase domain: a region with high homology to the insulin receptor contains one potential allosteric binding site, and another potential site on the other side of the kinase domain, near the hinge domain. These data, together with previous proof-of-concept efficacy studies demonstrating KZ-41 mitigates pathologic retinal neovascularization in the murine oxygen-induced retinopathy model, suggests that QA derivatives may offer therapeutic benefit in ischemic retinopathies.
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Affiliation(s)
- Hui He
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
| | - Rebecca L. Weir
- Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Jordan J. Toutounchian
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
| | - Jayaprakash Pagadala
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
| | - Jena J. Steinle
- Department of Anatomy, Wayne State University, Detroit, Michigan, United States of America
| | - Jerome Baudry
- Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Duane D. Miller
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
| | - Charles R. Yates
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
- Department of Ophthalmology, UTHSC College of Medicine, Memphis, Tennessee, United States of America
- * E-mail:
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14
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Kancherla S, Kohler WJ, van der Merwe Y, Chan KC. In Vivo Evaluation of the Visual Pathway in Streptozotocin-Induced Diabetes by Diffusion Tensor MRI and Contrast Enhanced MRI. PLoS One 2016; 11:e0165169. [PMID: 27768755 PMCID: PMC5074510 DOI: 10.1371/journal.pone.0165169] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 10/07/2016] [Indexed: 02/07/2023] Open
Abstract
Visual function has been shown to deteriorate prior to the onset of retinopathy in some diabetic patients and experimental animal models. This suggests the involvement of the brain's visual system in the early stages of diabetes. In this study, we tested this hypothesis by examining the integrity of the visual pathway in a diabetic rat model using in vivo multi-modal magnetic resonance imaging (MRI). Ten-week-old Sprague-Dawley rats were divided into an experimental diabetic group by intraperitoneal injection of 65 mg/kg streptozotocin in 0.01 M citric acid, and a sham control group by intraperitoneal injection of citric acid only. One month later, diffusion tensor MRI (DTI) was performed to examine the white matter integrity in the brain, followed by chromium-enhanced MRI of retinal integrity and manganese-enhanced MRI of anterograde manganese transport along the visual pathway. Prior to MRI experiments, the streptozotocin-induced diabetic rats showed significantly smaller weight gain and higher blood glucose level than the control rats. DTI revealed significantly lower fractional anisotropy and higher radial diffusivity in the prechiasmatic optic nerve of the diabetic rats compared to the control rats. No apparent difference was observed in the axial diffusivity of the optic nerve, the chromium enhancement in the retina, or the manganese enhancement in the lateral geniculate nucleus and superior colliculus between groups. Our results suggest that streptozotocin-induced diabetes leads to early injury in the optic nerve when no substantial change in retinal integrity or anterograde transport along the visual pathways was observed in MRI using contrast agent enhancement. DTI may be a useful tool for detecting and monitoring early pathophysiological changes in the visual system of experimental diabetes non-invasively.
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Affiliation(s)
- Swarupa Kancherla
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States of America
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - William J. Kohler
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States of America
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Yolandi van der Merwe
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States of America
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- Louis J. Fox Center for Vision Restoration, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Kevin C. Chan
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States of America
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- Louis J. Fox Center for Vision Restoration, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, PA, United States of America
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
- * E-mail:
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15
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Kong D, Gong L, Arnold E, Shanmugam S, Fort PE, Gardner TW, Abcouwer SF. Insulin-like growth factor 1 rescues R28 retinal neurons from apoptotic death through ERK-mediated BimEL phosphorylation independent of Akt. Exp Eye Res 2016; 151:82-95. [PMID: 27511131 DOI: 10.1016/j.exer.2016.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/27/2016] [Accepted: 08/05/2016] [Indexed: 10/21/2022]
Abstract
Insulin-like growth factor 1 (IGF-1) can provide long-term neurotrophic support by activation of Akt, inhibition of FoxO nuclear localization and suppression of Bim gene transcription in multiple neuronal systems. However, MEK/ERK activation can also promote neuron survival through phosphorylation of BimEL. We explored the contribution of the PI3K/Akt/FoxO and MEK/ERK/BimEL pathways in IGF-1 stimulated survival after serum deprivation (SD) of R28 cells differentiated to model retinal neurons. IGF-1 caused rapid activation of Akt leading to FoxO1/3-T32/T24 phosphorylation, and prevented FoxO1/3 nuclear translocation and Bim mRNA upregulation in response to SD. IGF-1 also caused MAPK/MEK pathway activation as indicated by ERK1/2-T202/Y204 and Bim-S65 phosphorylation. Overexpression of FoxO1 increased Bim mRNA expression and amplified the apoptotic response to SD without shifting the serum response curve. Inhibition of Akt activation with LY294002 or by Rictor knockdown did not block the protective effect of IGF-1, while inhibition of MEK activity with PD98059 prevented Bim phosphorylation and blocked IGF-1 protection. In addition, knockdown of Bim expression was protective during SD, while co-silencing of FoxO1 and Fox03 expression had little effect. Thus, the PI3K/Akt/FoxO pathway was not essential for protection from SD-induced apoptosis by IGF-1 in R28 cells. Instead, IGF-1 protection was dependent on activation of the MEK/ERK pathway leading to BimEL phosphorylation, which is known to prevent Bax/Bak oligomerization and activation of the intrinsic mitochondrial apoptosis pathway. These studies demonstrate the requirement of the MEK/ERK pathway in a model of retinal neuron cell survival and highlight the cell specificity for IGF-1 signaling in this response.
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Affiliation(s)
- Dejuan Kong
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, United States
| | - Lijie Gong
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, United States
| | - Edith Arnold
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, United States
| | - Sumathi Shanmugam
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, United States
| | - Patrice E Fort
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, United States
| | - Thomas W Gardner
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, United States
| | - Steven F Abcouwer
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, United States.
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16
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Ávila-Mendoza J, Mora J, Carranza M, Luna M, Arámburo C. Growth hormone reverses excitotoxic damage induced by kainic acid in the green iguana neuroretina. Gen Comp Endocrinol 2016; 234:57-67. [PMID: 27064058 DOI: 10.1016/j.ygcen.2016.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 04/05/2016] [Accepted: 04/05/2016] [Indexed: 11/28/2022]
Abstract
It is known that growth hormone (GH) is expressed in extrapituitary tissues, including the nervous system and ocular tissues, where it is involved in autocrine/paracrine actions related to cell survival and anti-apoptosis in several vertebrates. Little is known, however, in reptiles, so we analyzed the expression and distribution of GH in the eye of green iguana and its potential neuroprotective role in retinas that were damaged by the intraocular administration of kainic acid (KA). It was found, by Western blotting, that GH-immunoreactivity (GH-IR) was expressed as two isoforms (15 and 26kDa, under reducing conditions) in cornea, vitreous, retina, crystalline, iris and sclera, in varying proportions. Also, two bands for the growth hormone receptor (GHR)-IR were observed (70 and 44kDa, respectively) in the same tissues. By immunofluorescence, GH-IR was found in neurons present in several layers of the neuroretina (inner nuclear [INL], outer nuclear [ONL] and ganglion cell [GCL] layers) as determined by its co-existence with NeuN, but not in glial cells. In addition, GH and GHR co-expression was found in the same cells, suggesting paracrine/autocrine interactions. KA administration induced retinal excitotoxic damage, as determined by a significant reduction of the cell density and an increase in the appearance of apoptotic cells in the INL and GCL. In response to KA injury, both endogenous GH and Insulin-like Growth Factor I (IGF-I) expression were increased by 70±1.8% and 33.3±16%, respectively. The addition of exogenous GH significantly prevented the retinal damage produced by the loss of cytoarchitecture and cell density in the GCL (from 4.9±0.79 in the control, to 1.45±0.2 with KA, to 6.35±0.49cell/mm(2) with KA+GH) and in the INL (19.12±1.6, 10.05±1.9, 21.0±0.8cell/mm(2), respectively) generated by the long-term effect of 1mM KA intraocular administration. The co-incubation with a specific anti-GH antibody, however, blocked the protective effect of GH in GCL (1.4±0.23cell/mm(2)) and INL (11.35±1.06), respectively. Furthermore, added GH induced an increase of 90±14% in the retinal IGF-I concentration and the anti-GH antibody also blocked this effect. These results indicate that GH and GHR are expressed in the iguana eye and may be able to exert, either directly of mediated by IGF-I, a protective mechanism in neuroretinas that suffered damage by the administration of kainic acid.
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Affiliation(s)
- José Ávila-Mendoza
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico
| | - Janeth Mora
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico
| | - Martha Carranza
- 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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17
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Rathnasamy G, Foulds WS, Ling EA, Kaur C. Glutamate Inhibits the Pro-Survival Effects of Insulin-Like Growth Factor-1 on Retinal Ganglion Cells in Hypoxic Neonatal Rat Retina. Mol Neurobiol 2016; 54:3453-3464. [DOI: 10.1007/s12035-016-9905-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 05/03/2016] [Indexed: 11/29/2022]
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18
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Parker J, Mitrousis N, Shoichet MS. Hydrogel for Simultaneous Tunable Growth Factor Delivery and Enhanced Viability of Encapsulated Cells in Vitro. Biomacromolecules 2016; 17:476-84. [DOI: 10.1021/acs.biomac.5b01366] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- James Parker
- Department
of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
- Donnelly
Centre, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada
| | - Nikolaos Mitrousis
- Donnelly
Centre, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada
- Institute
of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
| | - Molly S. Shoichet
- Department
of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
- Donnelly
Centre, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada
- Institute
of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
- Department
of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E1, Canada
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19
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Aneke-Nash CS, Parrinello CM, Rajpathak SN, Rohan TE, Strotmeyer ES, Kritchevsky SB, Psaty BM, Bůžková P, Kizer JR, Newman AB, Strickler HD, Kaplan RC. Changes in insulin-like growth factor-I and its binding proteins are associated with diabetes mellitus in older adults. J Am Geriatr Soc 2015; 63:902-9. [PMID: 25989565 DOI: 10.1111/jgs.13390] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To determine whether changes in insulin-like growth factor (IGF) protein levels are greater in participants with type 2 diabetes mellitus or worsening glycemia than in normoglycemic individuals over a 9-year follow-up period. DESIGN Retrospective analysis of a cohort study. SETTING Participants were recruited from North Carolina, California, Maryland, and Pennsylvania. PARTICIPANTS Cardiovascular Health Study All Stars participants, a cohort study of community-dwelling adults aged 65 and older (N=897). MEASUREMENTS Plasma IGF-I, IGF binding protein (IGFBP)-1, and IGFBP-3 levels were assessed and American Diabetes Association cut-points for impaired glucose tolerance (IGT), impaired fasting glucose (IFG), and diabetes mellitus were used to classify participants at baseline (1996-97) and follow-up (2005-06). RESULTS At baseline, mean age was 76.3±3.6, and 18.5% had diabetes mellitus. Participants with IFG alone and IGT plus IFG had higher IGF-I levels and lower IGFBP-1 levels than those with normoglycemia or diabetes mellitus. The greatest percentage change in IGF levels occurred in those who had diabetes mellitus at baseline (9-year changes: -9.3% for IGF-I, 59.7% for IGFBP-1, -13.4% for IGFBP-3), the smallest in individuals who remained normoglycemic at follow-up (9-year changes: -3.7% for IGF-I, 25.6% for IGFBP-1, -6.4% for IGFBP-3), and intermediate in those who were normoglycemic but developed IFG at follow-up. CONCLUSION Degrees of glycemic impairment are associated with varying degrees of change in IGF protein levels. The changes observed in the diabetes mellitus group have been previously shown to be associated with heart failure, cancer, and noncancer mortality.
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Affiliation(s)
- Chino S Aneke-Nash
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
| | - Christina M Parrinello
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Swapnil N Rajpathak
- Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Merck & Co., Inc., Whitehouse Station, New Jersey
| | - Thomas E Rohan
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
| | - Elsa S Strotmeyer
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Stephen B Kritchevsky
- Sticht Center on Aging, Section on Gerontology and Geriatric Medicine, School of Medicine, Wake Forest University, Winston-Salem, North Carolina
| | - Bruce M Psaty
- Department of Biostatistics, University of Washington, Seattle, Washington
| | - Petra Bůžková
- Department of Biostatistics, University of Washington, Seattle, Washington
| | - Jorge R Kizer
- Departments of Medicine and Public Health, Weill Medical College, Cornell University, New York, New York
| | - Anne B Newman
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Howard D Strickler
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
| | - Robert C Kaplan
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
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20
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Wang H, Liao S, Geng R, Zheng Y, Liao R, Yan F, Thrimawithana T, Little PJ, Feng ZP, Lazarovici P, Zheng W. IGF-1 signaling via the PI3K/Akt pathway confers neuroprotection in human retinal pigment epithelial cells exposed to sodium nitroprusside insult. J Mol Neurosci 2014; 55:931-40. [PMID: 25339505 DOI: 10.1007/s12031-014-0448-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 10/13/2014] [Indexed: 02/01/2023]
Abstract
The pathological increase in the levels of the second messenger nitric oxide (NO) in the vitreous cavity and retina leads to injury and cell death of the retinal pigment epithelium (RPE) cells and eventually may contribute to the occurrence and development of diabetic retinopathy. In this study, we developed a cellular model of retinopathy using D407 cells (a human RPE cell line) exposed to sodium nitroprusside (SNP) and investigated the protective effect of the insulin-like growth factor-1 (IGF-1) towards this insult. Cell death and apoptosis were examined by the methyl thiazolyl tetrazolium assay and Hoechst staining, respectively. Specific inhibitors were used and phosphorylation of relevant signaling proteins was determined by Western blotting. SNP, in a concentration-dependent fashion, increased the production of reactive oxygen species (ROS) and lipid peroxidation process causing cell death by apoptosis of D407 cells. IGF-1, in a time- and dose-dependent manner, conferred protection towards SNP-mediated insult. Both phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) and mitogen-activated protein kinase (MAPK) were activated by IGF-1 in relation to the protective effect. Blockade of the PI3K/Akt pathway abolished the protective effect of IGF-1 whereas inhibition of the MAPK pathway was ineffective. SNP decreased the phosphorylation of Akt in the cells while IGF-1 reversed this inhibitory effect. These results indicate that the protective effect of IGF-1 on D407 exposed to SNP insult is mediated by the PI3K/Akt pathway. This proposal may be exploited in the clinic to improve the viability of insulted retinal cells for maintaining physiological vision.
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Affiliation(s)
- Haitao Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
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21
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Baptista FI, Pinto MJ, Elvas F, Martins T, Almeida RD, Ambrósio AF. Diabetes induces changes in KIF1A, KIF5B and dynein distribution in the rat retina: implications for axonal transport. Exp Eye Res 2014; 127:91-103. [PMID: 25064602 DOI: 10.1016/j.exer.2014.07.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 10/25/2022]
Abstract
Diabetic retinopathy is a leading cause of vision loss and blindness. Disruption of axonal transport is associated with many neurodegenerative diseases and might also play a role in diabetes-associated disorders affecting nervous system. We investigated the impact of type 1 diabetes (2 and 8 weeks duration) on KIF1A, KIF5B and dynein motor proteins in the retina. Additionally, since hyperglycemia is considered the main trigger of diabetic complications, we investigated whether prolonged exposure to elevated glucose could affect the content and distribution of motor proteins in retinal cultures. The immunoreactivity of motor proteins was evaluated by immunohistochemistry in retinal sections and by immunoblotting in total retinal extracts from streptozotocin-induced diabetic and age-matched control animals. Primary retinal cultures were exposed to high glucose (30 mM) or mannitol (osmotic control; 24.5 mM plus 5.5 mM glucose), for seven days. Diabetes decreased the content of KIF1A at 8 weeks of diabetes as well as KIF1A immunoreactivity in the majority of retinal layers, except for the photoreceptor and outer nuclear layer. Changes in KIF5B immunoreactivity were also detected by immunohistochemistry in the retina at 8 weeks of diabetes, being increased at the photoreceptor and outer nuclear layer, and decreased in the ganglion cell layer. Regarding dynein immunoreactivity there was an increase in the ganglion cell layer after 8 weeks of diabetes. No changes were detected in retinal cultures. These alterations suggest that axonal transport may be impaired under diabetes, which might contribute to early signs of neural dysfunction in the retina of diabetic patients and animal models.
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Affiliation(s)
- Filipa I Baptista
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3004-548 Coimbra, Portugal; Pharmacology and Experimental Therapeutics, IBILI, Faculty of Medicine, University of Coimbra, 3004-548 Coimbra, Portugal
| | - Maria J Pinto
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal; PhD Programme in Experimental Biology and Biomedicine (PDBEB), Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Filipe Elvas
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3004-548 Coimbra, Portugal; Pharmacology and Experimental Therapeutics, IBILI, Faculty of Medicine, University of Coimbra, 3004-548 Coimbra, Portugal
| | - Tiago Martins
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3004-548 Coimbra, Portugal; Pharmacology and Experimental Therapeutics, IBILI, Faculty of Medicine, University of Coimbra, 3004-548 Coimbra, Portugal
| | - Ramiro D Almeida
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - António F Ambrósio
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3004-548 Coimbra, Portugal; Pharmacology and Experimental Therapeutics, IBILI, Faculty of Medicine, University of Coimbra, 3004-548 Coimbra, Portugal; CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal; AIBILI, 3004-548 Coimbra, Portugal.
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22
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Yuan D, Xu Y, Hang H, Liu X, Chen X, Xie P, Yuan S, Zhang W, Lin X, Liu Q. Edaravone protect against retinal damage in streptozotocin-induced diabetic mice. PLoS One 2014; 9:e99219. [PMID: 24897298 PMCID: PMC4045952 DOI: 10.1371/journal.pone.0099219] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 05/12/2014] [Indexed: 12/04/2022] Open
Abstract
Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a free radical scavenger, is used for the clinical treatment of retinal injury. In this study, we investigated the protective effects of edaravone against diabetic retinal damage in the mouse. Diabetic retinopathy in the mouse was induced by injection of streptozotocin. Edaravone was given once-daily and was intraperitoneally (i.p.) treated at a dose of 3 mg/kg from streptozotocin injection to 4 weeks after onset of diabetes. Retinal ganglion cells (RGCs) damage was evaluated by recording the pattern electroretinogram (ERG). RGCs damage was also detected by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and the levels of reactive oxygen species (ROS) were determined fluorometrically. The expressions of phosporylated-ERK1/2, BDNF, and caspase-3 were determined by Western blot analysis. Retinal levels of ROS, phosphorylated ERK1/2, and cleaved caspase-3 were significantly increased, whereas the expression of BDNF was significantly decreased in the retinas of diabetic mice, compared to nondiabetic mice. Administration of edaravone significantly attenuated diabetes induced RGCs death, upregulation of ROS, ERK1/2 phosphorylation, and cleaved caspase-3 and downregulation of BDNF. These findings suggest that oxidative stress plays a pivotal role in diabetic retinal damage and that systemic administration of edaravone may slow the progression of retinal neuropathy induced by diabetes.
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Affiliation(s)
- Dongqing Yuan
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
| | - Yidan Xu
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
| | - Hui Hang
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
| | - Xiaoyi Liu
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
| | - Xi Chen
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
| | - Ping Xie
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
| | - Songtao Yuan
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
| | - Weiwei Zhang
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
| | - Xiaojun Lin
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
| | - Qinghuai Liu
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China
- * E-mail:
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23
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Trophic factors in the pathogenesis and therapy for retinal degenerative diseases. Surv Ophthalmol 2014; 59:134-65. [PMID: 24417953 DOI: 10.1016/j.survophthal.2013.09.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 12/27/2022]
Abstract
Trophic factors are endogenously secreted proteins that act in an autocrine and/or paracrine fashion to affect vital cellular processes such as proliferation, differentiation, and regeneration, thereby maintaining overall cell homeostasis. In the eye, the major contributors of these molecules are the retinal pigment epithelial (RPE) and Müller cells. The primary paracrine targets of these secreted proteins include the photoreceptors and choriocapillaris. Retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa are characterized by aberrant function and/or eventual death of RPE cells, photoreceptors, choriocapillaris, and other retinal cells. We discuss results of in vitro and in vivo animal studies in which candidate trophic factors, either singly or in combination, were used in an attempt to ameliorate photoreceptor and/or retinal degeneration. We also examine current trophic factor therapies as they relate to the treatment of retinal degenerative diseases in clinical studies.
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24
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Szabadfi K, Pinter E, Reglodi D, Gabriel R. Neuropeptides, trophic factors, and other substances providing morphofunctional and metabolic protection in experimental models of diabetic retinopathy. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 311:1-121. [PMID: 24952915 DOI: 10.1016/b978-0-12-800179-0.00001-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Vision is the most important sensory modality for many species, including humans. Damage to the retina results in vision loss or even blindness. One of the most serious complications of diabetes, a disease that has seen a worldwide increase in prevalence, is diabetic retinopathy. This condition stems from consequences of pathological metabolism and develops in 75% of patients with type 1 and 50% with type 2 diabetes. The development of novel protective drugs is essential. In this review we provide a description of the disease and conclude that type 1 diabetes and type 2 diabetes lead to the same retinopathy. We evaluate existing experimental models and recent developments in finding effective compounds against this disorder. In our opinion, the best models are the long-term streptozotocin-induced diabetes and Otsuka Long-Evans Tokushima Fatty and spontaneously diabetic Torii rats, while the most promising substances are topically administered somatostatin and pigment epithelium-derived factor analogs, antivasculogenic substances, and systemic antioxidants. Future drug development should focus on these.
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Affiliation(s)
- Krisztina Szabadfi
- Department of Experimental Zoology and Neurobiology, University of Pecs, Pecs, Hungary; Janos Szentagothai Research Center, University of Pecs, Pecs, Hungary.
| | - Erika Pinter
- Janos Szentagothai Research Center, University of Pecs, Pecs, Hungary; Department of Pharmacology and Pharmacotherapy, University of Pecs, Pecs, Hungary
| | - Dora Reglodi
- Department of Anatomy, PTE MTA Lendulet-PACAP Research Team, University of Pecs, Pecs, Hungary
| | - Robert Gabriel
- Department of Experimental Zoology and Neurobiology, University of Pecs, Pecs, Hungary; Janos Szentagothai Research Center, University of Pecs, Pecs, Hungary
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Bu SY, Yu GH, Xu GX. Expression of insulin-like growth factor 1 receptor in rat retina following optic nerve injury. Acta Ophthalmol 2013; 91:e427-31. [PMID: 23648097 DOI: 10.1111/aos.12096] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To investigate the apoptosis in retinal ganglion cells (RGCs) and insulin-like growth factor 1 receptor (IGF-1R) in the retina following optic nerve crush. METHODS Healthy Wistar rats (N = 70) were divided into two groups: a normal control group and an optic nerve injury group. Immunohistochemistry and flow cytometry were performed to detect the expression of IGF-1R and to measure the apoptosis of RGCs, respectively. RESULTS Immunohistochemistry revealed that at 1 hr after optic nerve injury, IGF-1R immunoreactivity began to increase and reached a maximal level at 24 hr (p < 0.05), where it remained elevated up to 14 days after injury. RGC apoptosis in the normal control group was 0.53%, while the apoptosis rate in the optic nerve injury group increased over time. The apoptosis rate in the optic nerve injury group was 1.4% at 1 hr, 4.4% at 6 hr, 5.2% at 12 hr and reached a maximal level (8.5%) at 24 hr. Subsequently, the rate declined to 1.9% 7 days after injury and 0.9% 2 weeks after injury. CONCLUSION The IGF-1R immunereactivity in the retina increased after optic nerve injury. IGF-1R may regulate the apoptosis and regeneration of RGCs at different stages after optic nerve injury.
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Affiliation(s)
- Shu-yang Bu
- Department of Ophthalmology, The Second Affiliated Hospital of Soochow University, Suzhou, China.
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Šerbedžija P, Ishii DN. Insulin and insulin-like growth factor prevent brain atrophy and cognitive impairment in diabetic rats. Indian J Endocrinol Metab 2012; 16:S601-S610. [PMID: 23565496 PMCID: PMC3602990 DOI: 10.4103/2230-8210.105578] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
There are an estimated 36 million dementia patients worldwide. The anticipated tripling of this number by year 2050 will negatively impact the capacity to deliver quality health care. The epidemic in diabetes is particularly troubling, because diabetes is a substantial risk factor for dementia independently of cerebrovascular disease. There is an urgent need to elucidate the pathogenesis of progressive brain atrophy, the cause of dementia, to allow rational design of new therapeutic interventions. This review summarizes recent tests of the hypothesis that the concomitant loss of insulin and insulin-like growth factors (IGFs) is the dominant cause for age-dependent, progressive brain atrophy with degeneration and cognitive decline. These tests are the first to show that insulin and IGFs regulate adult brain mass by maintaining brain protein content. Insulin and IGF levels are reduced in diabetes, and replacement of both ligands can prevent loss of total brain protein, widespread cell degeneration, and demyelination. IGF alone prevents retinal degeneration in diabetic rats. It supports synapses and is required for learning and memory. Replacement doses in diabetic rats can cross the blood-brain barrier to prevent hippocampus-dependent memory impairment. Insulin and IGFs are protective despite unabated hyperglycemia in diabetic rats, severely restricting hyperglycemia and its consequences as dominant pathogenic causes of brain atrophy and impaired cognition. These findings have important implications for late-onset alzheimer's disease (LOAD) where diabetes is a major risk factor, and concomitant decline in insulin and IGF activity suggest a similar pathogenesis for brain atrophy and dementia.
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Affiliation(s)
- Predrag Šerbedžija
- Department of Pharmacology, University of Colorado, Aurora, CO 80045, USA
| | - Douglas N. Ishii
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
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27
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Quintessential Risk Factors: Their Role in Promoting Cognitive Dysfunction and Alzheimer’s Disease. Neurochem Res 2012; 37:2627-58. [DOI: 10.1007/s11064-012-0854-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 07/21/2012] [Indexed: 12/13/2022]
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Fernandez DC, Pasquini LA, Dorfman D, Aldana Marcos HJ, Rosenstein RE. Early distal axonopathy of the visual pathway in experimental diabetes. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:303-13. [PMID: 22079928 DOI: 10.1016/j.ajpath.2011.09.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2011] [Revised: 09/01/2011] [Accepted: 09/08/2011] [Indexed: 02/01/2023]
Abstract
Diabetic retinopathy is a leading cause of acquired blindness. Visual function disorders have been observed in diabetic patients with very early retinopathy or even before the onset of retinopathy. The aim of the present work was to analyze the visual pathway in an early stage of experimental diabetes. Diabetes was induced in Wistar rats by an i.p. injection of streptozotocin. A deficit in anterograde transport from the retina to the superior colliculus was observed 6 weeks after streptozotocin injection. At this time point, morphologic studies did not reveal retinal ganglion cell loss or substantial alterations in the superior colliculus. The optic nerve was morphometrically evaluated at intraorbital (unmyelinated and myelinated) and intracranial sections. In animals that had been diabetic for 6 weeks, a large increase in astrocyte reactivity occurred in the distal (but not the intraorbital) portion, which coincided with significant axon loss. Moreover, profound myelin alterations and altered morphologic features of oligodendrocyte lineage were observed at the distal (but not the proximal) optic nerve portion. The present results suggest that axoglial alterations at the distal portion of the optic nerve could be the first structural change in the diabetic visual pathway.
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Affiliation(s)
- Diego C Fernandez
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine, University of Buenos Aires/CEFyBO, CONICET, Buenos Aires, Argentina
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29
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Li P, Xu X, Zheng Z, Zhu B, Shi Y, Liu K. Protective Effects of Rosiglitazone on Retinal Neuronal Damage in Diabetic Rats. Curr Eye Res 2011; 36:673-9. [DOI: 10.3109/02713683.2011.572220] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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30
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Wong VHY, Bui BV, Vingrys AJ. Clinical and experimental links between diabetes and glaucoma. Clin Exp Optom 2010; 94:4-23. [PMID: 21091536 DOI: 10.1111/j.1444-0938.2010.00546.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Glaucoma is a leading cause of blindness. It is a multifactorial condition, the risk factors for which are increasingly well defined from large-scale epidemiological studies. One risk factor that remains controversial is the presence of diabetes. It has been proposed that diabetic eyes are at greater risk of injury from external stressors, such as elevated intraocular pressure. Alternatively, diabetes may cause ganglion cell loss, which becomes additive to a glaucomatous ganglion cell injury. Several clinical trials have considered whether a link exists between diabetes and glaucoma. In this review, we outline these studies and consider the causes for their lack of concordant findings. We also review the biochemical and cellular similarities between the two conditions. Moreover, we review the available literature that attempts to answer the question of whether the presence of diabetes increases the risk of developing glaucoma. At present, laboratory studies provide robust evidence for an association between diabetes and glaucoma.
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Affiliation(s)
- Vickie H Y Wong
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
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31
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Rod photoreceptor cell death is induced by okadaic acid through activation of PKC and L-type voltage-dependent Ca2+ channels and prevented by IGF-1. Neurochem Int 2010; 57:128-35. [DOI: 10.1016/j.neuint.2010.04.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 04/14/2010] [Accepted: 04/29/2010] [Indexed: 02/02/2023]
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32
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Jiang Y, Steinle JJ. Systemic propranolol reduces b-wave amplitude in the ERG and increases IGF-1 receptor phosphorylation in rat retina. Invest Ophthalmol Vis Sci 2009; 51:2730-5. [PMID: 20042659 DOI: 10.1167/iovs.09-4779] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine whether systemic application of propranolol, a nonselective beta-adrenergic receptor antagonist, with an osmotic pump will decrease the b-wave amplitude of the electroretinogram (ERG) and increase insulin-like growth factor (IGF)-1 receptor signaling. METHODS Young rats at 8 weeks of age were treated with saline, phentolamine, a nonselective alpha-adrenergic receptor antagonist, or propranolol, a nonselective beta-adrenergic receptor antagonist, delivered by osmotic pumps for 21 days. On the 21st day, all rats underwent electroretinographic analyses followed by collection of the retinas for protein assessment using Western blot analysis for IGF binding protein 3 (IGFBP3), IGF-1 receptor (IGF-1R), Akt, extracellular signal-related kinases 1 and 2 (ERK1/2), and vascular endothelial cell growth factor (VEGF). RESULTS Data indicate that 21 days of propranolol significantly decreased the b-wave amplitude of the ERG. The decrease in the b-wave amplitude occurred concurrently with a decrease in IGFBP3 levels and an increase in tyrosine phosphorylation of IGF-1 receptor on 1135/1136. This phosphorylation of IGF-1 receptor led to increased phosphorylation of Akt and ERK1/2. VEGF protein levels were also increased. CONCLUSIONS Overall, beta-adrenergic receptor antagonism produced a dysfunctional ERG, which occurred with an increase in IGF-1R phosphorylation and activation of VEGF. Systemic application of beta-adrenergic receptor antagonists may have detrimental effects on the retina.
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Affiliation(s)
- Youde Jiang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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33
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Serbedzija P, Madl JE, Ishii DN. Insulin and IGF-I prevent brain atrophy and DNA loss in diabetes. Brain Res 2009; 1303:179-94. [PMID: 19781531 DOI: 10.1016/j.brainres.2009.09.063] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 09/14/2009] [Accepted: 09/15/2009] [Indexed: 01/21/2023]
Abstract
The aim of this study was to identify factors that regulate the bulk of adult brain mass, and test the hypothesis that concomitantly reduced insulin and insulin-like growth factor (IGF) levels are pathogenic for brain atrophy associated with impaired learning and memory in diabetes. Doses of insulin, or insulin plus IGF-I that were too small to prevent hyperglycemia were infused for 12 weeks into the brain lateral ventricles of streptozotocin-diabetic adult rats. Brain wet, water and dry weights were significantly decreased in diabetic rats; insulin prevented these decreases. The decrease in brain DNA and protein contents in diabetic rats was prevented by the combination treatment, but not by insulin alone. Levels of several glia- and neuron-associated proteins were reduced in diabetes; these reductions were also prevented by the combination treatment. Although hyperglycemia was not prevented in plasma or cerebrospinal fluid, insulin prevented brain atrophy but not bulk DNA loss in diabetes, whereas the combination prevented both. Insulin actively prevented the loss of brain water content as well. Brain atrophy is associated with concomitantly reduced levels of insulin and IGF in other disorders such as Alzheimer's disease.
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Affiliation(s)
- Predrag Serbedzija
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
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Beresewicz M, Majewska M, Makarewicz D, Vayro S, Zabłocka B, Górecki DC. Changes in the expression of insulin-like growth factor 1 variants in the postnatal brain development and in neonatal hypoxia-ischaemia. Int J Dev Neurosci 2009; 28:91-7. [PMID: 19766709 DOI: 10.1016/j.ijdevneu.2009.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 09/07/2009] [Accepted: 09/13/2009] [Indexed: 01/08/2023] Open
Abstract
Insulin-like growth factor-1 (IGF-1) is a multifunctional peptide of which numerous isoforms exist. The predominant form, IGF-1Ea is involved in physiological processes while IGF-1Ec (mechano-growth factor, MGF) is expressed in response to a different set of stimuli. We have identified specific changes in the expression patterns of these IGF-1 variants in brain development in normal rats and following neonatal hypoxia-ischaemia (HI). Both IGF-1Ea and IGF-1Ec are expressed during normal postnatal brain development, albeit with highly specific temporal distributions. In contrast, HI produced increased and prolonged expression of the IGF-1Ec isoform only. Importantly, hypoxia alone stimulated the expression of IGF-1Ec as well. Thus, IGF-1Ec may play a role in HI pathology. Neonatal hypoxia-ischaemia occurs in approximately 1:4000-1:10,000 newborns and causes neurological deficits in approximately 75% of those affected. Unfortunately, no specific treatment is available. IGF-1 is known to have neuroprotective activity and its IGF-1Ec variant appears to be an endogenous protective factor in hypoxia-ischaemia. Therefore, IGF-1Ec could potentially be developed into a therapeutic modality for the attenuation or prevention of neuronal damage in this and related disorders.
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Affiliation(s)
- Małgorzata Beresewicz
- Molecular Biology Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
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Jiang Y, Walker RJ, Steinle JJ. Age-associated increase in cleaved caspase 3 despite phosphorylation of IGF-1 receptor in the rat retina. J Gerontol A Biol Sci Med Sci 2009; 64:1154-9. [PMID: 19696229 DOI: 10.1093/gerona/glp102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Diseases of aging produce many alterations in the retina, but changes in growth factor signaling in normal aging are less characterized. This study investigated modifications in insulin-like growth factor-1 (IGF-1) receptor (IGF-1R) signaling in the retina of Brown Norway x Fischer 344 F1 hybrid rats at 8, 22, and 32 months. Immunoblotting for proteins involved in IGF-1R signal transduction and electroretinograms were done to evaluate changes with aging. Aging produced a significant decrease in b-wave and oscillatory potential amplitudes in the retina. Aging produced increased phosphorylation of IGF-1R. Despite the increase in IGF-1R activity, insulin receptor substrate-1 (IRS-1) phosphorylation was significantly decreased with increasing age. Akt activity was significantly decreased at 22 and 32 months of age, resulting in increased cleaved caspase 3 levels. The results suggest that regulation of IRS-1 phosphorylation may modulate apoptotic rates in the aging retina, potentially preventing activation of vascular endothelial cell growth factor.
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Affiliation(s)
- Youde Jiang
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN, USA
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36
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Kowluru RA, Chan PS. Metabolic memory in diabetes - from in vitro oddity to in vivo problem: role of apoptosis. Brain Res Bull 2009; 81:297-302. [PMID: 19463916 DOI: 10.1016/j.brainresbull.2009.05.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 05/07/2009] [Accepted: 05/07/2009] [Indexed: 11/26/2022]
Abstract
Retinal capillary cells undergo apoptosis before pathology characteristic of retinopathy can be observed, and the appearance of apoptotic capillary cell can predict the development of pathology. The purpose of this study is to investigate the effect of reversal of hyperglycemia on retinal capillary cell apoptosis, and identify the apoptosis encoding genes. Streptozotocin-diabetic rats were maintained either in poor glycemic control (PC, glycated hemoglobin, GHb >11%) or in good glycemic control (GC, GHb <6%) for 12 months, or allowed to be in PC for 6 months followed by GC for 6 additional months (PC-GC). Capillary cell apoptosis was determined in the trypsin-digested retinal microvasculature by TUNEL staining, and the genes encoding apoptosis were identified by Oligo GEArray rat apoptosis microarray that profiles 113 genes. Six months of good glycemic control that followed 6 months of poor control failed to attenuate the number of TUNEL-positive capillary cells in the retinal microvasculature. Twenty-three retinal genes, mainly from TNF ligand and receptor, caspase, Bcl-2 and death domain subfamilies that were upregulated by least a two-fold in PC rats remain upregulated after reversal of hyperglycemia. Thus, the continued activation of apoptosis plays a major role in the resistance of retinopathy to halt after re-institution of good glycemic control, and the regulation apoptosis machinery could help retard the progression of diabetic retinopathy.
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Affiliation(s)
- Renu A Kowluru
- Kresge Eye Institute, Wayne State University, 4717 St. Antoine, Detroit, MI 48201, USA.
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37
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Bui BV, Loeliger M, Thomas M, Vingrys AJ, Rees SM, Nguyen CTO, He Z, Tolcos M. Investigating structural and biochemical correlates of ganglion cell dysfunction in streptozotocin-induced diabetic rats. Exp Eye Res 2009; 88:1076-83. [PMID: 19450451 DOI: 10.1016/j.exer.2009.01.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 01/15/2009] [Accepted: 01/19/2009] [Indexed: 11/30/2022]
Abstract
The aim of this study was to determine whether inner retinal dysfunction in diabetic rats is correlated with structural and/or biochemical changes in the retina and optic nerve. Using the electroretinogram (ERG; -5.83 to 1.28 log cd.s.m(-2)) retinal function (photoreceptor, bipolar, amacrine and ganglion cell components) was measured in control (n=13; citrate buffer) and diabetic (n=13; streptozotocin, STZ, 50 mg kg(-1)) rats, 12 weeks following treatment. Retinae and optic nerves were analyzed for structural changes and retinae were assessed for alterations in growth factor/cytokine expression using quantitative real-time PCR. We found that phototransduction efficiency was reduced 12 weeks after STZ-induced diabetes (-30%), leading to reduced amplitude of ON-bipolar (-18%) and amacrine cell (-29%) dominated responses; ganglion cell dysfunction (-84%) was more profound. In the optic nerve, nerve fascicle area and myelin sheath thickness were reduced (p<0.05), whereas the ratio of blood vessels and connective tissue to total nerve cross-sectional area was increased (p<0.05) in diabetic compared to control rats. In the retina, connective tissue growth factor (CTGF), transforming growth factor beta, type 2 receptor (TGFbeta-r2) mRNA and platelet-derived growth factor B (PDGF-B) mRNA were increased (p<0.035). Reduced ganglion cell function was correlated with increased CTGF and TGFbeta-r2, but not PDGF-B mRNA. In summary, the ganglion cell component exhibited the greatest level of dysfunction within the ERG components examined after 12 weeks of STZ-induced diabetes; the level correlated with increased CTGF and TGFbeta-r2 mRNA, but not with gross morphological changes in the retina or optic nerve.
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Affiliation(s)
- Bang V Bui
- Department of Optometry & Vision Sciences, University of Melbourne, Parkville, Victoria 3010, Australia
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Abstract
Diabetic retinopathy has long been recognized as a vascular disease that develops in most patients, and it was believed that the visual dysfunction that develops in some diabetics was due to the vascular lesions used to characterize the disease. It is becoming increasingly clear that neuronal cells of the retina also are affected by diabetes, resulting in dysfunction and even degeneration of some neuronal cells. Retinal ganglion cells (RGCs) are the best studied of the retinal neurons with respect to the effect of diabetes. Although investigations are providing new information about RGCs in diabetes, including therapies to inhibit the neurodegeneration, critical information about the function, anatomy and response properties of these cells is yet needed to understand the relationship between RGC changes and visual dysfunction in diabetes.
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Affiliation(s)
- Timothy S Kern
- Center for Diabetes Research, Department of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
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39
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Landau D, Segev Y. Role of IGF-I in Type 2 diabetes: a focus on the mouse model. Expert Rev Endocrinol Metab 2008; 3:43-49. [PMID: 30743784 DOI: 10.1586/17446651.3.1.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Insulin resistance, the key mechanism in Type 2 diabetes mellitus (T2DM) is also associated with the deregulation of other glucose homeostasis pathways, such as the growth hormone (GH)-IGF-I system. In this review, we summarize the endocrine and renal GH-IGF axis changes in db/db mice, a model of T2DM, and compare it with the nonobese diabetic mouse model of T1DM. In the latter, elevated circulating GH levels (associated with kidney disease) could be ameliorated with the use of GH antagonists. Contrary to that, in the obese db/db mice, serum GH and IGF-I levels are decreased and tissue levels of IGF-binding protein 1 (Igfbp1) are increased. The latter hinted again for the known inverse correlation between insulin and Igfbp1 and was mediated by changes in the transcription factor phosphorylated forkhead box O1 in obese animals. In addition, the decrease in circulating IGF-I and GH levels causes a state of low free and active IGF-I, which may further impair tissue viability (including pancreatic β-cells). Thus, further GH inhibition to modulate complications in T2DM is not indicated, but the therapeutic role of IGF-1 in this disease remains to be determined.
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Affiliation(s)
- Daniel Landau
- a Department of Pediatrics A, Faculty of Health Sciences, Ben Gurion University of the Negev, Soroka University Medical Center, PO Box 151, Beer Sheva 84101, Israel.
| | - Yael Segev
- b Department of Microbiology and Immunology, Faculty of Health Sciences, Ben Gurion University of the Negev, Soroka University Medical Center, PO Box 151, Beer Sheva 84101, Israel.
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Górecki DC, Beresewicz M, Zabłocka B. Neuroprotective effects of short peptides derived from the Insulin-like growth factor 1. Neurochem Int 2007; 51:451-8. [PMID: 17582656 DOI: 10.1016/j.neuint.2007.04.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 04/03/2007] [Accepted: 04/25/2007] [Indexed: 11/22/2022]
Abstract
Insulin-like growth factor I (IGF-1) is a peptide synthesized in response to growth hormone stimulation. While most of the circulating IGF-1 comes from the liver, it can also be produced in other tissues and both its expression and processing undergo tissue-specific regulation. The predominant form, IGF-1Ea is a circulating factor while two others, IGF-1Eb and IGF-1Ec (MGF), are mostly expressed in different tissues or in response to various stimuli and show some preferences with respect to the signal transduction pathways they activate. In skeletal muscle specific forms of IGF-1 play a role in development and growth and in addition to these physiological roles IGF-1 functions in the damaged muscle. IGF-1 is also important for the developing and adult brain and can reduce neuronal death caused by different types of injuries. Like many other peptide hormones IGF-1 originates from a precursor pro-hormone that undergoes extensive post-translational modifications. Processing liberates the mature peptide, which acts via the specific IGF-1 receptor but additional short peptides can arise from both N- and C-termini of various IGF-1 isoforms. These derivatives function as autonomous biologically active peptides and extremely potent neuroprotective agents. Their biological effects are independent of the activation of the IGF-1 receptor. Unfortunately, little is known about their mechanism(s) of action. Likewise, the existence of the endogenous production and wider biological effects of these short peptides are uncertain. However, considering the difference in the modes of action it might be possible to dissociate the unwanted and potentially dangerous mitogenic activity of the full-length IGF-1 exerted via its receptor from the neuroprotective effects of short derivatives mediated through different pathways. Such small molecules show good penetration through the blood brain barrier, can be inexpensively manufactured and modified to increase their stability. Therefore, they are good candidates for development into a neuroprotective therapeutic modality.
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Affiliation(s)
- Dariusz C Górecki
- Institute of Biomedical and Biomolecular Sciences, School of Pharmacy and Biomedical Sciences, Portsmouth, England, United Kingdom
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Bibliography. Current world literature. Diabetes and the endocrine pancreas. Curr Opin Endocrinol Diabetes Obes 2007; 14:170-96. [PMID: 17940437 DOI: 10.1097/med.0b013e3280d5f7e9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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