scholarly journals TGFβ-Neurotrophin Interactions in Heart, Retina, and Brain

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1360
Author(s):  
Anja Schlecht ◽  
Mario Vallon ◽  
Nicole Wagner ◽  
Süleyman Ergün ◽  
Barbara M. Braunger
Keyword(s):  
Tissue Damage ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Age Related Macular Degeneration ◽  
Retinal Tissue ◽  
Age Related ◽  
Retinal Blood Vessels ◽  
Secondary Tissue ◽  
The Individual ◽  
Neurotrophin Signaling

Ischemic insults to the heart and brain, i.e., myocardial and cerebral infarction, respectively, are amongst the leading causes of death worldwide. While there are therapeutic options to allow reperfusion of ischemic myocardial and brain tissue by reopening obstructed vessels, mitigating primary tissue damage, post-infarction inflammation and tissue remodeling can lead to secondary tissue damage. Similarly, ischemia in retinal tissue is the driving force in the progression of neovascular eye diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD), which eventually lead to functional blindness, if left untreated. Intriguingly, the easily observable retinal blood vessels can be used as a window to the heart and brain to allow judgement of microvascular damages in diseases such as diabetes or hypertension. The complex neuronal and endocrine interactions between heart, retina and brain have also been appreciated in myocardial infarction, ischemic stroke, and retinal diseases. To describe the intimate relationship between the individual tissues, we use the terms heart-brain and brain-retina axis in this review and focus on the role of transforming growth factor β (TGFβ) and neurotrophins in regulation of these axes under physiologic and pathologic conditions. Moreover, we particularly discuss their roles in inflammation and repair following ischemic/neovascular insults. As there is evidence that TGFβ signaling has the potential to regulate expression of neurotrophins, it is tempting to speculate, and is discussed here, that cross-talk between TGFβ and neurotrophin signaling protects cells from harmful and/or damaging events in the heart, retina, and brain.

HtrA1: a novel regulator of physiological and pathological matrix mineralization?

2007 ◽  
Vol 35 (4) ◽  
pp. 669-671 ◽  
Author(s):  
A.E. Canfield ◽  
K.D. Hadfield ◽  
C.F. Rock ◽  
E.C. Wylie ◽  
F.L. Wilkinson
Keyword(s):  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Matrix Gla Protein ◽  
Age Related Macular Degeneration ◽  
Matrix Mineralization ◽  
Age Related ◽  
Morphogenetic Protein ◽  
Serine Protease Activity ◽  
Bmp Signalling

HtrA1 (high-temperature requirement protein A1) is a secreted multidomain protein with proven serine protease activity and the ability to regulate TGF-β (transforming growth factor-β)/BMP (bone morphogenetic protein) signalling. There is increasing evidence that HtrA1 regulates several pathological processes, including tumour development, Alzheimer's disease, age-related macular degeneration and osteoarthritis, although the mechanism(s) by which it regulates these processes have not been fully elucidated. Using overexpression and knock-down strategies, we have evidence demonstrating that HtrA1 is also a key regulator of physiological and pathological matrix mineralization in vitro. We propose that HtrA1 regulates mineralization by inhibiting TGF-β/BMP signalling and/or by cleaving specific matrix proteins, including decorin and MGP (matrix Gla protein). Taken together, these studies suggest that HtrA1 may be a novel therapeutic target for several diseases.

scholarly journals Cell–Matrix Interactions in the Eye: From Cornea to Choroid

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 687
Author(s):  
Andrew E. Pouw ◽  
Mark A. Greiner ◽  
Razek G. Coussa ◽  
Chunhua Jiao ◽  
Ian C. Han ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Transforming Growth Factor Β ◽  
Corneal Dystrophy ◽  
Tissue Growth ◽  
Age Related Macular Degeneration ◽  
Disease States ◽  
Age Related

The extracellular matrix (ECM) plays a crucial role in all parts of the eye, from maintaining clarity and hydration of the cornea and vitreous to regulating angiogenesis, intraocular pressure maintenance, and vascular signaling. This review focuses on the interactions of the ECM for homeostasis of normal physiologic functions of the cornea, vitreous, retina, retinal pigment epithelium, Bruch’s membrane, and choroid as well as trabecular meshwork, optic nerve, conjunctiva and tenon’s layer as it relates to glaucoma. A variety of pathways and key factors related to ECM in the eye are discussed, including but not limited to those related to transforming growth factor-β, vascular endothelial growth factor, basic-fibroblastic growth factor, connective tissue growth factor, matrix metalloproteinases (including MMP-2 and MMP-9, and MMP-14), collagen IV, fibronectin, elastin, canonical signaling, integrins, and endothelial morphogenesis consistent of cellular activation-tubulogenesis and cellular differentiation-stabilization. Alterations contributing to disease states such as wound healing, diabetes-related complications, Fuchs endothelial corneal dystrophy, angiogenesis, fibrosis, age-related macular degeneration, retinal detachment, and posteriorly inserted vitreous base are also reviewed.

scholarly journals Pirfenidone Alleviates Choroidal Neovascular Fibrosis through TGF-β/Smad Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Chuang Gao ◽  
Xin Cao ◽  
Lili Huang ◽  
Yueqi Bao ◽  
Tao Li ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Transforming Growth Factor Β ◽  
Age Related Macular Degeneration ◽  
Type I ◽  
Fundus Fluorescein Angiography ◽  
Smad Signaling ◽  
Age Related ◽  
Smad Signaling Pathway

Background. Transforming growth factor-β (TGF-β) plays a major role in CNV. However, the mechanism is unclear. This study investigates the effect of Pirfenidone (PFD) on TGF-β/Smad signaling pathway on the development of choroidal neovascular fibrosis in choroidal neovascularization (CNV) mouse model. C57BL/6J male mice (aged from 6 to 8 weeks) received intravitreal injections of phosphate-buffered saline (PBS)/PFD solution on 14 days after laser injury. Mice were anesthetized by intraperitoneal injection of 4% pentobarbital (0.05 mg/g body weight). Optical Coherence Tomography (OCT), Fundus Fluorescein angiography (FFA), and hematoxylin-eosin (HE) were used to assess CNV formation. The fibrosis area was monitored by staining the collagen type I (Col-I). Western blotting was used to analyze the expression of TGF-β2, Smad 2/3, phosphorylated Smad 2/3 (p-Smad 2/3), and α-smooth muscle actin (α-SMA). Terminal deoxynucleotidy1 transferase dUTP nick-end labelling (TUNEL) assay was performed on cryosections of mouse eyes to detect apoptosis. Our data showed PFD inhibited areas of fibrosis during day 21 to day 28. We also found that the levels of TGF-β2 protein expressions increasingly reached the peak till the 3rd week during the CNV development. The protein levels of Smad 2/3, p-Smad 2/3, and α-SMA also increased significantly in CNV mice, but this response was profoundly suppressed by the TGF-β inhibitor PFD. The results of this study suggest that TGF-β2 represents a target to prevent or treat choroidal neovascular fibrosis, and PFD may provide an alternative to traditional methods for Wet Age-related macular degeneration (wAMD) treatment.

scholarly journals LRG1 as a novel therapeutic target in eye disease

Eye ◽  
2022 ◽  
Author(s):  
Giulia De Rossi ◽  
Marlene E. Da Vitoria Lobo ◽  
John Greenwood ◽  
Stephen E. Moss
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Age Related Macular Degeneration ◽  
New Drugs ◽  
High Rate ◽  
Eye Disease ◽  
Ageing Population ◽  
Age Related ◽  
Number Of Patients

AbstractRetinal and choroidal diseases are major causes of blindness and visual impairment in the developed world and on the rise due to an ageing population and diabetes epidemic. Standard of care is centred around blockade of vascular endothelial growth factor (VEGF), but despite having halved the number of patients losing sight, a high rate of patient non-response and loss of efficacy over time are key challenges. Dysregulation of vascular homoeostasis, coupled with fibrosis and inflammation, are major culprits driving sight-threatening eye diseases. Improving our knowledge of these pathological processes should inform the development of new drugs to address the current clinical challenges for patients. Leucine-rich α-2 glycoprotein 1 (LRG1) is an emerging key player in vascular dysfunction, inflammation and fibrosis. Under physiological conditions, LRG1 is constitutively expressed by the liver and granulocytes, but little is known about its normal biological function. In pathological scenarios, such as diabetic retinopathy (DR) and neovascular age-related macular degeneration (nvAMD), its expression is ectopically upregulated and it acquires a much better understood pathogenic role. Context-dependent modulation of the transforming growth-factor β (TGFβ) pathway is one of the main activities of LRG1, but additional roles have recently been emerging. This review aims to highlight the clinical and pre-clinical evidence for the pathogenic contribution of LRG1 to vascular retinopathies, as well as extrapolate from other diseases, functions which may be relevant to eye disease. Finally, we will provide a current update on the development of anti-LRG1 therapies for the treatment of nvAMD.

Abstract 65: Restoration of Growth Differentiation Factor 11 Protects Against Stroke in Mice

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Anjali Chauhan ◽  
Jacob Hudobenko ◽  
Anthony Patrizz ◽  
Louise D McCullough
Keyword(s):  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
The Elderly ◽  
Vehicle Group ◽  
Peripheral Tissues ◽  
Delayed Treatment ◽  
Aged Mice ◽  
Infarct Area ◽  
Age Related

Introduction: GDF 11 is a member of the transforming growth factor β superfamily. Loss of GDF11 occurs with aging and declining levels correlate with several detrimental age-associated phenotypes in both peripheral tissues and brain. Restoration of GDF11 enhances neurogenesis and cognitive function in aged mice. Brain expression of GDF11 has not been investigated after stroke. Stroke differentially affects the elderly. In this work we examined the role of GDF11 in aging, stroke and its potential utility as a neuroprotective agent. Methods: Male C57/BL6NCrl young (2-3 months) and aged (19-21) mice were used. Brain GDF11 expression was evaluated in young and aged mice by western blot. Focal ischemia was induced with a transient middle cerebral artery occlusion (MCAO). Mice were randomly assigned into two groups and were subjected to 90 min MCAO. Group 1 received vehicle (phosphate buffered saline) and group 2 was administered rGDF11 (100 ug/kg., ip) at the onset of ischemia. In additional experiments, the efficacy of delayed treatment (3 h after ischemia) with rGDF11 was tested. These mice were subjected to a 60 min MCAO. Mice were euthanized after 24 hours and 7 days respectively and brains were harvested to estimate infarct area. Results: A significant decrease in brain GDF11 levels was observed in aged mice as compared to young (p<0.05). Additionally, a significant decline in brain GDF11 expression was observed after stroke at 24 hours vs. sham groups (p<0.05). A significant decrease in cortical and hemispheric infarct area was observed in the rGDF11 group (cortical 48.73±1.05; hemisphere 49.68±3.58) as compared to vehicle group (60.54±4.88; 61.35±6.03), when GDF was administered at the time of ischemia. Delayed treatment with rGDF11 also reduced infarct at 7 days. Conclusions: Brain GDF11 levels decline with age and after stroke. Supplementation with rGDF11 ameliorates stroke induced injury in young mice at 24h and 7 days. These finding suggest potential role of GDF11 in age and stroke. Restoration of age-related loss of GDF may be a viable therapy for stroke.

scholarly journals Macrophage to myofibroblast transition contributes to subretinal fibrosis secondary to neovascular age-related macular degeneration

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Karis Little ◽  
Maria Llorián-Salvador ◽  
Miao Tang ◽  
Xuan Du ◽  
Stephen Marry ◽  
...  
Keyword(s):  
Growth Factor ◽  
Macular Degeneration ◽  
Transforming Growth Factor ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Two Stage ◽  
Blocking Antibody ◽  
Age Related ◽  
Subretinal Fibrosis ◽  
Isolectin B4

Abstract Background Macular fibrosis causes irreparable vision loss in neovascular age-related macular degeneration (nAMD) even with anti-vascular endothelial growth factor (VEGF) therapy. Inflammation is known to play an important role in macular fibrosis although the underlying mechanism remains poorly defined. The aim of this study was to understand how infiltrating macrophages and complement proteins may contribute to macular fibrosis. Methods Subretinal fibrosis was induced in C57BL/6J mice using the two-stage laser protocol developed by our group. The eyes were collected at 10, 20, 30 and 40 days after the second laser and processed for immunohistochemistry for infiltrating macrophages (F4/80 and Iba-1), complement components (C3a and C3aR) and fibrovascular lesions (collagen-1, Isolectin B4 and α-SMA). Human retinal sections with macular fibrosis were also used in the study. Bone marrow-derived macrophages (BMDMs) from C57BL/6J mice were treated with recombinant C3a, C5a or TGF-β for 48 and 96 h. qPCR, Western blot and immunohistochemistry were used to examine the expression of myofibroblast markers. The involvement of C3a-C3aR pathway in macrophage to myofibroblast transition (MMT) and subretinal fibrosis was further investigated using a C3aR antagonist (C3aRA) and a C3a blocking antibody in vitro and in vivo. Results Approximately 20~30% of F4/80+ (or Iba-1+) infiltrating macrophages co-expressed α-SMA in subretinal fibrotic lesions both in human nAMD eyes and in the mouse model. TGF-β and C3a, but not C5a treatment, significantly upregulated expression of α-SMA, fibronectin and collagen-1 in BMDMs. C3a-induced upregulation of α-SMA, fibronectin and collagen-1 in BMDMs was prevented by C3aRA treatment. In the two-stage laser model of induced subretinal fibrosis, treatment with C3a blocking antibody but not C3aRA significantly reduced vascular leakage and Isolectin B4+ lesions. The treatment did not significantly alter collagen-1+ fibrotic lesions. Conclusions MMT plays a role in macular fibrosis secondary to nAMD. MMT can be induced by TGF-β and C3a but not C5a. Further research is required to fully understand the role of MMT in macular fibrosis. Graphical abstract Macrophage to myofibroblast transition (MMT) contributes to subretinal fibrosis. Subretinal fibrosis lesions contain various cell types, including macrophages and myofibroblasts, and are fibrovascular. Myofibroblasts are key cells driving pathogenic fibrosis, and they do so by producing excessive amount of extracellular matrix proteins. We have found that infiltrating macrophages can transdifferentiate into myofibroblasts, a phenomenon termed macrophage to myofibroblast transition (MMT) in macular fibrosis. In addition to TGF-β1, C3a generated during complement activation in CNV can also induce MMT contributing to macular fibrosis. RPE = retinal pigment epithelium. BM = Bruch’s membrane. MMT = macrophage to myofibroblast transition. TGFB = transforming growth factor β. a-SMA = alpha smooth muscle actin. C3a = complement C3a.

scholarly journals Inflammatory Mediators and Angiogenic Factors in Choroidal Neovascularization: Pathogenetic Interactions and Therapeutic Implications

2010 ◽  
Vol 2010 ◽  
pp. 1-14 ◽  
Author(s):  
Claudio Campa ◽  
Ciro Costagliola ◽  
Carlo Incorvaia ◽  
Carl Sheridan ◽  
Francesco Semeraro ◽  
...  
Keyword(s):  
Growth Factor ◽  
Choroidal Neovascularization ◽  
Inflammatory Mediators ◽  
Transforming Growth Factor ◽  
Pathological Condition ◽  
Inflammatory Cells ◽  
Angiogenic Factors ◽  
Age Related Macular Degeneration ◽  
Therapeutic Implications ◽  
Age Related

Choroidal neovascularization (CNV) is a common and severe complication in heterogeneous diseases affecting the posterior segment of the eye, the most frequent being represented by age-related macular degeneration. Although the term may suggest just a vascular pathological condition, CNV is more properly definable as an aberrant tissue invasion of endothelial and inflammatory cells, in which both angiogenesis and inflammation are involved. Experimental and clinical evidences show that vascular endothelial growth factor is a key signal in promoting angiogenesis. However, many other molecules, distinctive of the inflammatory response, act as neovascular activators in CNV. These include fibroblast growth factor, transforming growth factor, tumor necrosis factor, interleukins, and complement. This paper reviews the role of inflammatory mediators and angiogenic factors in the development of CNV, proposing pathogenetic assumptions of mutual interaction. As an extension of this concept, new therapeutic approaches geared to have an effect on both the vascular and the extravascular components of CNV are discussed.

More than a cell biosensor: aryl hydrocarbon receptor at the intersection of physiology and inflammation

2020 ◽  
Vol 318 (6) ◽  
pp. C1078-C1082 ◽  
Author(s):  
Tiziana Guarnieri ◽  
Provvidenza Maria Abruzzo ◽  
Alessandra Bolotta
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Inflammatory Mediators ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Downstream Target ◽  
Aryl Hydrocarbon ◽  
Inflammatory State ◽  
A Cell ◽  
The Individual ◽  
Inflammatory Molecules

Aryl hydrocarbon receptor (AhR), a highly conserved intracellular transcription factor, is activated by a plethora of ligands of both exogenous and endogenous nature. Besides activating xenobiotic-metabolizing enzymes, it is involved in the differentiation and development of hematopoietic, hepatic, nervous and immune systems. More and more data describe its role in the regulation of immune responses and in the onset and progression of inflammation. Particularly, established results view AhR as a downstream target of inflammatory molecules, since its transcription is regulated by the inflammatory cascade. Interleukin 6 (IL-6) has been described to sustain early stages of inflammation and to influence the expression of AhR either directly, following signal transducer and activator of transcription 3 (STAT3) activation, or in combination with other inflammatory mediators, e.g., transforming growth factor-β (TGF-β). In selected inflammatory milieus, once activated, AhR interacts with its targets including the IL-6 promoter, thus originating an autoinflammatory loop. This perspective review brings together evidence that, in some IL-6-driven pathways, AhR is a downstream target that amplifies the duration and extent of inflammation. Considering that many inflammatory mediators can also trigger the activities of AhR as biosensor and activator of xenobiotics metabolism, this issue is of pivotal importance. The individual susceptibly to some environmental ligands of AhR can be probably explained by considering the individual inflammatory state, which could additionally fuel the proinflammatory activity of AhR. Thus, AhR could be considered a transductor of a dynamic, bidirectional connection between internal and external environmental stimuli and the inflammatory response.

scholarly journals Alagebrium inhibits neointimal hyperplasia and restores distributions of wall shear stress by reducing downstream vascular resistance in obese and diabetic rats

2015 ◽  
Vol 309 (7) ◽  
pp. H1130-H1140 ◽  
Author(s):  
Hongfeng Wang ◽  
Dorothee Weihrauch ◽  
Judy R. Kersten ◽  
Jeffrey M. Toth ◽  
Anthony G. Passerini ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Vascular Resistance ◽  
Transforming Growth Factor ◽  
Oxidized Ldl ◽  
Neointimal Hyperplasia ◽  
Ldl Receptor ◽  
Transforming Growth Factor Β ◽  
Age Related ◽  
Wall Shear

Mechanisms of restenosis in type 2 diabetes mellitus (T2DM) are incompletely elucidated, but advanced glycation end-product (AGE)-induced vascular remodeling likely contributes. We tested the hypothesis that AGE-related collagen cross-linking (ARCC) leads to increased downstream vascular resistance and altered in-stent hemodynamics, thereby promoting neointimal hyperplasia (NH) in T2DM. We proposed that decreasing ARCC with ALT-711 (Alagebrium) would mitigate this response. Abdominal aortic stents were implanted in Zucker lean (ZL), obese (ZO), and diabetic (ZD) rats. Blood flow, vessel diameter, and wall shear stress (WSS) were calculated after 21 days, and NH was quantified. Arterial segments (aorta, carotid, iliac, femoral, and arterioles) were harvested to detect ARCC and protein expression, including transforming growth factor-β (TGF-β) and receptor for AGEs (RAGE). Downstream resistance was elevated (60%), whereas flow and WSS were significantly decreased (44% and 56%) in ZD vs. ZL rats. NH was increased in ZO but not ZD rats. ALT-711 reduced ARCC and resistance (46%) in ZD rats while decreasing NH and producing similar in-stent WSS across groups. No consistent differences in RAGE or TGF-β expression were observed in arterial segments. ALT-711 modified lectin-type oxidized LDL receptor 1 but not RAGE expression by cells on decellularized matrices. In conclusion, ALT-711 decreased ARCC, increased in-stent flow rate, and reduced NH in ZO and ZD rats through RAGE-independent pathways. The study supports an important role for AGE-induced remodeling within and downstream of stent implantation to promote enhanced NH in T2DM.

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