1
|
Mirzahosseini G, Adam JM, Nasoohi S, El-Remessy AB, Ishrat T. Lost in Translation: Neurotrophins Biology and Function in the Neurovascular Unit. Neuroscientist 2023; 29:694-714. [PMID: 35769016 DOI: 10.1177/10738584221104982] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The neurovascular unit (NVU) refers to the functional building unit of the brain and the retina, where neurons, glia, and microvasculature orchestrate to meet the demand of the retina's and brain's function. Neurotrophins (NTs) are structural families of secreted proteins and are known for exerting neurotrophic effects on neuronal differentiation, survival, neurite outgrowth, synaptic formation, and plasticity. NTs include several molecules, such as nerve growth factor, brain-derived neurotrophic factor, NT-3, NT-4, and their precursors. Furthermore, NTs are involved in signaling pathways such as inflammation, apoptosis, and angiogenesis in a nonneuronal cell type. Interestingly, NTs and the precursors can bind and activate the p75 neurotrophin receptor (p75NTR) at low and high affinity. Mature NTs bind their cognate tropomyosin/tyrosine-regulated kinase receptors, crucial for maintenance and neuronal development in the brain and retina axis. Activation of p75NTR results in neuronal apoptosis and cell death, while tropomysin receptor kinase upregulation contributes to differentiation and cell growth. Recent findings indicate that modulation of NTs and their receptors contribute to neurovascular dysfunction in the NVU. Several chronic metabolic and acute ischemic diseases affect the NVU, including diabetic and ischemic retinopathy for the retina, as well as stroke, acute encephalitis, and traumatic brain injury for the brain. This work aims to review the current evidence through published literature studying the impact of NTs and their receptors, including the p75NTR receptor, on the injured and healthy brain-retina axis.
Collapse
Affiliation(s)
- Golnoush Mirzahosseini
- Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Justin Mark Adam
- Department of Medicine, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Sanaz Nasoohi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Tauheed Ishrat
- Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| |
Collapse
|
2
|
Subirada PV, Tovo A, Vaglienti MV, Luna Pinto JD, Saragovi HU, Sánchez MC, Anastasía A, Barcelona PF. Etiological Roles of p75 NTR in a Mouse Model of Wet Age-Related Macular Degeneration. Cells 2023; 12:cells12020297. [PMID: 36672232 PMCID: PMC9856885 DOI: 10.3390/cells12020297] [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: 12/12/2022] [Revised: 01/04/2023] [Accepted: 01/06/2023] [Indexed: 01/13/2023] Open
Abstract
Choroidal neovascularization (CNV) is a pathological angiogenesis of the choroidal plexus of the retina and is a key feature in the wet form of age-related macular degeneration. Mononuclear phagocytic cells (MPCs) are known to accumulate in the subretinal space, generating a chronic inflammatory state that promotes the growth of the choroidal neovasculature. However, how the MPCs are recruited and activated to promote CNV pathology is not fully understood. Using genetic and pharmacological tools in a mouse model of laser-induced CNV, we demonstrate a role for the p75 neurotrophin receptor (p75NTR) in the recruitment of MPCs, in glial activation, and in vascular alterations. After laser injury, expression of p75NTR is increased in activated Muller glial cells near the CNV area in the retina and the retinal pigmented epithelium (RPE)-choroid. In p75NTR knockout mice (p75NTR KO) with CNV, there is significantly reduced recruitment of MPCs, reduced glial activation, reduced CNV area, and the retinal function is preserved, as compared to wild type mice with CNV. Notably, a single intravitreal injection of a pharmacological p75NTR antagonist in wild type mice with CNV phenocopied the results of the p75NTR KO mice. Our results demonstrate that p75NTR is etiological in the development of CNV.
Collapse
Affiliation(s)
| | - Albana Tovo
- Departamento de Bioquímica Clínica, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Córdoba 5016, Argentina
| | - María Victoria Vaglienti
- Departamento de Bioquímica Clínica, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Córdoba 5016, Argentina
| | | | - Horacio Uri Saragovi
- Lady Davis Research Institute-Jewish General Hospital, Center for Experimental Therapeutics, Department of Pharmacology and Therapeutics, Department of Ophthalmology and Vision Sciences, McGill University, Montreal, QC H3T 1E2, Canada
| | - Maria Cecilia Sánchez
- Departamento de Bioquímica Clínica, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Córdoba 5016, Argentina
| | - Agustín Anastasía
- Instituto Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba 5016, Argentina
- Instituto Universitario de Ciencias Biomédicas de Córdoba (IUCBC), Córdoba 5016, Argentina
- Correspondence: (A.A.); (P.F.B.)
| | - Pablo Federico Barcelona
- Departamento de Bioquímica Clínica, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Córdoba 5016, Argentina
- Correspondence: (A.A.); (P.F.B.)
| |
Collapse
|
3
|
Zafer D, Adams T, Olson E, Stenman L, Taparli O, Eickhoff J, Cengiz P, Mezu-Ndubuisi OJ. Retinal vascular recovery revealed by retinal imaging following neonatal hypoxia ischemia in mice: Is there a role for tyrosine kinase receptor modulation? Brain Res 2022; 1796:148093. [PMID: 36116486 PMCID: PMC10013450 DOI: 10.1016/j.brainres.2022.148093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 09/06/2022] [Accepted: 09/11/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Hypoxic ischemic encephalopathy (HIE) secondary to perinatal asphyxia leads to long-term visual disabilities. Dilated retinal exams in human newborns with HIE is an emerging diagnostic tool, but phenotypes of hypoxia ischemia (HI) related retinal vascular injury are unclear. 7,8-Dihydroxyflavone (7,8-DHF) is a TrkB agonist with protective effects on HI-related brain damage. We studied retinal vessels in a mouse model of neonatal HIE and the efficacy of 7,8-DHF in ameliorating HI-related retinal vascular injury. METHODS C57BL6/J mice at post-natal day (P) 9 received unilateral left carotid artery ligation followed by exposure to 10 % oxygen for 50 min. Phosphate buffered saline or 7,8-DHF (5 mg/kg) were administered daily for 7 days intraperitoneally. Control groups of naïve or carotid artery ligation only mice were studied. Fluorescein angiography was performed in acute (two weeks post-exposure) and chronic (four weeks post-exposure) time points. Retinal artery width, retinal vein width, and collateral vessel length were quantified. RESULTS Ligation of the common carotid artery alone caused retinal artery dilation in acute and chronic time points, but had no effect on retinal veins. At acute time point, HI caused increased retinal artery vasodilation, but was reversed by 7,8-DHF. HI caused short collateral vessel formation in ipsilateral eyes, rescued by 7,8-DHF treatment. CONCLUSION Retinal artery vasodilation and collateral vessel formation due to HI were rescued by 7,8-DHF treatment. Retinal and collateral vessel monitoring could be diagnostic biomarkers for HI severity. Studies to elucidate mechanisms of 7,8-DHF action on retinal vessels could aid development of therapies for neonatal HI.
Collapse
Affiliation(s)
- Dila Zafer
- Department of Pediatrics, University of Wisconsin, Madison, WI, USA; Waisman Center, University of Wisconsin, Madison, WI, USA
| | - Thao Adams
- Department of Pediatrics, University of Wisconsin, Madison, WI, USA
| | - Ellie Olson
- Department of Pediatrics, University of Wisconsin, Madison, WI, USA
| | - Lauren Stenman
- Department of Pediatrics, University of Wisconsin, Madison, WI, USA.
| | - Onur Taparli
- Department of Pediatrics, University of Wisconsin, Madison, WI, USA; Waisman Center, University of Wisconsin, Madison, WI, USA.
| | - Jens Eickhoff
- Department of Pediatrics, University of Wisconsin, Madison, WI, USA.
| | - Pelin Cengiz
- Department of Pediatrics, University of Wisconsin, Madison, WI, USA; Waisman Center, University of Wisconsin, Madison, WI, USA.
| | - Olachi J Mezu-Ndubuisi
- Department of Pediatrics, University of Rochester, Rochester, NY, USA; Department of Ophthalmology, University of Rochester, Rochester, NY, USA.
| |
Collapse
|
4
|
Yu Y, Xia LK, Di Y, Nie QZ, Chen XL. Mechanism of piR-1245/PIWI-like protein-2 regulating Janus kinase-2/signal transducer and activator of transcription-3/vascular endothelial growth factor signaling pathway in retinal neovascularization. Neural Regen Res 2022; 18:1132-1138. [PMID: 36255003 PMCID: PMC9827762 DOI: 10.4103/1673-5374.355819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Inhibiting retinal neovascularization is the optimal strategy for the treatment of retina-related diseases, but there is currently no effective treatment for retinal neovascularization. P-element-induced wimpy testis (PIWI)-interacting RNA (piRNA) is a type of small non-coding RNA implicated in a variety of diseases. In this study, we found that the expression of piR-1245 and the interacting protein PIWIL2 were remarkably increased in human retinal endothelial cells cultured in a hypoxic environment, and cell apoptosis, migration, tube formation and proliferation were remarkably enhanced in these cells. Knocking down piR-1245 inhibited the above phenomena. After intervention by a p-JAK2 activator, piR-1245 decreased the expression of hypoxia inducible factor-1α and vascular endothelial growth factor through the JAK2/STAT3 pathway. For in vivo analysis, 7-day-old newborn mice were raised in 75 ± 2% hyperoxia for 5 days and then piR-1245 in the retina was knocked down. In these mice, the number of newly formed vessels in the retina was decreased, the expressions of inflammation-related proteins were reduced, the number of apoptotic cells in the retina was decreased, the JAK2/STAT3 pathway was inhibited, and the expressions of hypoxia inducible factor-1α and vascular endothelial growth factor were decreased. Injection of the JAK2 inhibitor JAK2/TYK2-IN-1 into the vitreous cavity inhibited retinal neovascularization in mice and reduced expression of hypoxia inducible factor-1α and vascular endothelial growth factor. These findings suggest that piR-1245 activates the JAK2/STAT3 pathway, regulates the expression of hypoxia inducible factor-1α and vascular endothelial growth factor, and promotes retinal neovascularization. Therefore, piR-1245 may be a new therapeutic target for retinal neovascularization.
Collapse
Affiliation(s)
- Yong Yu
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Li-Kun Xia
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Yu Di
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Qing-Zhu Nie
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Xiao-Long Chen
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China,Correspondence to: Xiao-Long Chen, .
| |
Collapse
|
5
|
Modulation of Mesenchymal Stem Cells for Enhanced Therapeutic Utility in Ischemic Vascular Diseases. Int J Mol Sci 2021; 23:ijms23010249. [PMID: 35008675 PMCID: PMC8745455 DOI: 10.3390/ijms23010249] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 12/12/2022] Open
Abstract
Mesenchymal stem cells are multipotent stem cells isolated from various tissue sources, including but not limited to bone marrow, adipose, umbilical cord, and Wharton Jelly. Although cell-mediated mechanisms have been reported, the therapeutic effect of MSCs is now recognized to be primarily mediated via paracrine effects through the secretion of bioactive molecules, known as the “secretome”. The regenerative benefit of the secretome has been attributed to trophic factors and cytokines that play neuroprotective, anti-angiogenic/pro-angiogenic, anti-inflammatory, and immune-modulatory roles. The advancement of autologous MSCs therapy can be hindered when introduced back into a hostile/disease environment. Barriers include impaired endogenous MSCs function, limited post-transplantation cell viability, and altered immune-modulatory efficiency. Although secretome-based therapeutics have gained popularity, many translational hurdles, including the heterogeneity of MSCs, limited proliferation potential, and the complex nature of the secretome, have impeded the progress. This review will discuss the experimental and clinical impact of restoring the functional capabilities of MSCs prior to transplantation and the progress in secretome therapies involving extracellular vesicles. Modulation and utilization of MSCs–secretome are most likely to serve as an effective strategy for promoting their ultimate success as therapeutic modulators.
Collapse
|
6
|
Tang JJ, Feng S, Chen XD, Huang H, Mao M, Wang HY, Li S, Lu XM, Wang YT. The Effects of P75NTR on Learning Memory Mediated by Hippocampal Apoptosis and Synaptic Plasticity. Curr Pharm Des 2021; 27:531-539. [PMID: 32938344 DOI: 10.2174/1381612826666200916145142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 08/18/2020] [Indexed: 11/22/2022]
Abstract
Neurological diseases bring great mental and physical torture to the patients, and have long-term and sustained negative effects on families and society. The attention to neurological diseases is increasing, and the improvement of the material level is accompanied by an increase in the demand for mental level. The p75 neurotrophin receptor (p75NTR) is a low-affinity neurotrophin receptor and involved in diverse and pleiotropic effects in the developmental and adult central nervous system (CNS). Since neurological diseases are usually accompanied by the regression of memory, the pathogenesis of p75NTR also activates and inhibits other signaling pathways, which has a serious impact on the learning and memory of patients. The results of studies shown that p75NTR is associated with LTP/LTD-induced synaptic enhancement and inhibition, suggest that p75NTR may be involved in the progression of synaptic plasticity. And its proapoptotic effect is associated with activation of proBDNF and inhibition of proNGF, and TrkA/p75NTR imbalance leads to pro-survival or proapoptotic phenomena. It can be inferred that p75NTR mediates apoptosis in the hippocampus and amygdale, which may affect learning and memory behavior. This article mainly discusses the relationship between p75NTR and learning memory and associated mechanisms, which may provide some new ideas for the treatment of neurological diseases.
Collapse
Affiliation(s)
- Jun-Jie Tang
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Shuang Feng
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Xing-Dong Chen
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Hua Huang
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Min Mao
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Hai-Yan Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Sen Li
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Xiu-Min Lu
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Yong-Tang Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| |
Collapse
|
7
|
Elshaer SL, Park HS, Pearson L, Hill WD, Longo FM, El-Remessy AB. Modulation of p75 NTR on Mesenchymal Stem Cells Increases Their Vascular Protection in Retinal Ischemia-Reperfusion Mouse Model. Int J Mol Sci 2021; 22:E829. [PMID: 33467640 PMCID: PMC7830385 DOI: 10.3390/ijms22020829] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/10/2021] [Accepted: 01/11/2021] [Indexed: 12/17/2022] Open
Abstract
Mesenchymal stem cells (MSCs) are a promising therapy to improve vascular repair, yet their role in ischemic retinopathy is not fully understood. The aim of this study is to investigate the impact of modulating the neurotrophin receptor; p75NTR on the vascular protection of MSCs in an acute model of retinal ischemia/reperfusion (I/R). Wild type (WT) and p75NTR-/- mice were subjected to I/R injury by increasing intra-ocular pressure to 120 mmHg for 45 min, followed by perfusion. Murine GFP-labeled MSCs (100,000 cells/eye) were injected intravitreally 2 days post-I/R and vascular homing was assessed 1 week later. Acellular capillaries were counted using trypsin digest 10-days post-I/R. In vitro, MSC-p75NTR was modulated either genetically using siRNA or pharmacologically using the p75NTR modulator; LM11A-31, and conditioned media were co-cultured with human retinal endothelial cells (HREs) to examine the angiogenic response. Finally, visual function in mice undergoing retinal I/R and receiving LM11A-31 was assessed by visual-clue water-maze test. I/R significantly increased the number of acellular capillaries (3.2-Fold) in WT retinas, which was partially ameliorated in p75NTR-/- retinas. GFP-MSCs were successfully incorporated and engrafted into retinal vasculature 1 week post injection and normalized the number of acellular capillaries in p75NTR-/- retinas, yet ischemic WT retinas maintained a 2-Fold increase. Silencing p75NTR on GFP-MSCs coincided with a higher number of cells homing to the ischemic WT retinal vasculature and normalized the number of acellular capillaries when compared to ischemic WT retinas receiving scrambled-GFP-MSCs. In vitro, silencing p75NTR-MSCs enhanced their secretome, as evidenced by significant increases in SDF-1, VEGF and NGF release in MSCs conditioned medium; improved paracrine angiogenic response in HREs, where HREs showed enhanced migration (1.4-Fold) and tube formation (2-Fold) compared to controls. In parallel, modulating MSCs-p75NTR using LM11A-31 resulted in a similar improvement in MSCs secretome and the enhanced paracrine angiogenic potential of HREs. Further, intervention with LM11A-31 significantly mitigated the decline in visual acuity post retinal I/R injury. In conclusion, p75NTR modulation can potentiate the therapeutic potential of MSCs to harness vascular repair in ischemic retinopathy diseases.
Collapse
Affiliation(s)
- Sally L. Elshaer
- Augusta Biomedical Research Corporation, Charlie Norwood VA Medical Center, Augusta, GA 30901, USA; (S.L.E.); (L.P.); (W.D.H.)
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - Hang-soo Park
- Department of Surgery, University of Illinois at Chicago, Chicago, IL 60612, USA;
- Department of Obstetrics and Gynecology, University of Chicago, Chicago, IL 60637, USA
| | - Laura Pearson
- Augusta Biomedical Research Corporation, Charlie Norwood VA Medical Center, Augusta, GA 30901, USA; (S.L.E.); (L.P.); (W.D.H.)
| | - William D. Hill
- Augusta Biomedical Research Corporation, Charlie Norwood VA Medical Center, Augusta, GA 30901, USA; (S.L.E.); (L.P.); (W.D.H.)
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29403, USA
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29403, USA
| | - Frank M. Longo
- Department of Neurology and Neurological Sciences, Stanford University, Palo Alto, CA 94304, USA;
| | - Azza B. El-Remessy
- Augusta Biomedical Research Corporation, Charlie Norwood VA Medical Center, Augusta, GA 30901, USA; (S.L.E.); (L.P.); (W.D.H.)
- Department of Surgery, University of Illinois at Chicago, Chicago, IL 60612, USA;
- Department of the Pharmacy, Doctors Hospital of Augusta, Augusta, GA 30909, USA
| |
Collapse
|
8
|
c-Jun N-terminal Kinase Mediates Ligand-independent p75 NTR Signaling in Mesencephalic Cells Subjected to Oxidative Stress. Neuroscience 2020; 453:222-236. [PMID: 33253821 DOI: 10.1016/j.neuroscience.2020.11.036] [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: 05/30/2020] [Revised: 11/01/2020] [Accepted: 11/22/2020] [Indexed: 12/11/2022]
Abstract
The p75 neurotrophin receptor (p75NTR) is a multifunctional protein that regulates cellular responses to pathological conditions in specific regions of the nervous system. Activation of p75NTR in certain neuronal populations induces proteolytic processing of the receptor, thereby generating p75NTR fragments that facilitate downstream signaling. Expression of p75NTR has been reported in neurons of the ventral midbrain, but p75NTR signaling mechanisms in such cells are poorly understood. Here, we used Lund Human Mesencephalic cells, a population of neuronal cells derived from the ventral mesencephalon, to evaluate the effects of oxidative stress on p75NTR signaling. Subjection of the cells to oxidative stress resulted in decreased cell-surface localization of p75NTR and intracellular accumulation of p75NTR fragments. Oxidative stress-induced p75NTR processing was reduced by pharmacological inhibition of metalloproteases or γ-secretase, but was unaltered by blockade of the ligand-binding domain of p75NTR. Furthermore, inhibition of c-Jun N-terminal Kinase (JNK) decreased p75NTR cleavage induced by oxidative damage. Altogether, these results support a mechanism of p75NTR activation in which oxidative stress stimulates JNK signaling, thereby facilitating p75NTR processing via a ligand-independent mechanism involving induction of metalloprotease and γ-secretase activity. These findings reveal a novel role for JNK in ligand-independent p75NTR signaling, and, considering the susceptibility of mesencephalic neurons to oxidative damage associated with Parkinson's disease (PD), merit further investigation into the effects of p75NTR on PD-related neurodegeneration.
Collapse
|
9
|
Elshaer SL, Alwhaibi A, Mohamed R, Lemtalsi T, Coucha M, Longo FM, El-Remessy AB. Modulation of the p75 neurotrophin receptor using LM11A-31 prevents diabetes-induced retinal vascular permeability in mice via inhibition of inflammation and the RhoA kinase pathway. Diabetologia 2019; 62:1488-1500. [PMID: 31073629 PMCID: PMC8808141 DOI: 10.1007/s00125-019-4885-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/28/2019] [Indexed: 02/07/2023]
Abstract
AIMS/HYPOTHESIS Breakdown of the inner blood-retinal barrier (BRB) is an early event in the pathogenesis of diabetic macular oedema, that eventually leads to vision loss. We have previously shown that diabetes causes an imbalance of nerve growth factor (NGF) isoforms resulting in accumulation of its precursor proNGF and upregulation of the p75 neurotrophin receptor (p75NTR), with consequent increases in the activation of Ras homologue gene family, member A (RhoA). We also showed that genetic deletion of p75NTR in diabetes preserved the BRB and prevented inflammatory mediators in retinas. This study aims to examine the therapeutic potential of LM11A-31, a small-molecule p75NTR modulator and proNGF antagonist, in preventing diabetes-induced BRB breakdown. The study also examined the role of p75NTR/RhoA downstream signalling in mediating cell permeability. METHODS Male C57BL/6 J mice were rendered diabetic using streptozotocin injection. After 2 weeks of diabetes, mice received oral gavage of LM11A-31 (50 mg kg-1 day-1) or saline (NaCl 154 mmol/l) for an additional 4 weeks. BRB breakdown was assessed by extravasation of BSA-AlexaFluor-488. Direct effects of proNGF were examined in human retinal endothelial (HRE) cells in the presence or absence of LM11A-31 or the Rho kinase inhibitor Y-27632. RESULTS Diabetes triggered BRB breakdown and caused significant increases in circulatory and retinal TNF-α and IL-1β levels. These effects coincided with significant decreases in retinal NGF and increases in vascular endothelial growth factor and proNGF expression, as well as activation of RhoA. Interventional modulation of p75NTR activity through treatment of mouse models of diabetes with LM11A-31 significantly mitigated proNGF accumulation and preserved BRB integrity. In HRE cells, treatment with mutant proNGF (10 ng/ml) triggered increased cell permeability with marked reduction of expression of tight junction proteins, zona occludens-1 (ZO-1) and claudin-5, compared with control, independent of inflammatory mediators or cell death. Modulating p75NTR significantly inhibited proNGF-mediated RhoA activation, occludin phosphorylation (at serine 490) and cell permeability. ProNGF induced redistribution of ZO-1 in the cell wall and formation of F-actin stress fibres; these effects were mitigated by LM11A-31. CONCLUSIONS/INTERPRETATION Targeting p75NTR signalling using LM11A-31, an orally bioavailable receptor modulator, may offer an effective, safe and non-invasive therapeutic strategy for treating macular oedema, a major cause of blindness in diabetes.
Collapse
Affiliation(s)
- Sally L Elshaer
- Augusta Biomedical Research Corporation, Augusta, GA, USA
- Charlie Norwood VA Medical Center, Augusta, GA, USA
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Abdulrahman Alwhaibi
- Augusta Biomedical Research Corporation, Augusta, GA, USA
- Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Riyaz Mohamed
- Augusta Biomedical Research Corporation, Augusta, GA, USA
- Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Tahira Lemtalsi
- Augusta Biomedical Research Corporation, Augusta, GA, USA
- Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Maha Coucha
- Augusta Biomedical Research Corporation, Augusta, GA, USA
- Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University, Palo Alto, CA, USA
| | - Azza B El-Remessy
- Augusta Biomedical Research Corporation, Augusta, GA, USA.
- Charlie Norwood VA Medical Center, Augusta, GA, USA.
- Department of the Pharmacy, Doctors Hospital of Augusta, Augusta, GA, 30909, USA.
| |
Collapse
|