Background— Lymphatic network and chemokine-mediated signals are essential for leukocyte traffic during the proximal steps of alloimmune response. We aimed to determine the role of lymphatic vessels and their principal growth signaling pathway, vascular endothelial growth factor (VEGF)-C/D/VEGFR-3, during acute and chronic rejection in cardiac allografts. Methods and Results— Analysis of heterotopically transplanted rat cardiac allografts showed that chronic rejection increased VEGF-C + inflammatory cell and hyaluronan receptor-1 (LYVE-1) + lymphatic vessel density. Allograft lymphatic vessels were VEGFR-3 + , contained antigen-presenting cells, and produced dendritic cell chemokine CCL21. Experiments with VEGFR-3/LacZ mice or mice with green fluorescent protein–positive bone marrow cells as cardiac allograft recipients showed that allograft lymphatic vessels originated almost exclusively from donor cells. Intraportal adenoviral VEGFR-3-Ig (Ad.VEGFR-3-Ig/VEGF-C/D-Trap) perfusion was used to inhibit VEGF-C/D/VEGFR-3 signaling. Recipient treatment with Ad.VEGFR-3-Ig prolonged rat cardiac allograft survival. Ad.VEGFR-3-Ig did not affect allograft lymphangiogenesis but was linked to reduced CCL21 production and CD8 + effector cell entry in the allograft. Concomitantly, Ad.VEGFR-3-Ig reduced OX62 + dendritic cell recruitment and increased transcription factor Foxp3 expression in the spleen. In separate experiments, treatment with a neutralizing monoclonal VEGFR-3 antibody reduced arteriosclerosis, the number of activated lymphatic vessels expressing VEGFR-3 and CCL21, and graft-infiltrating CD4 + T cells in chronically rejecting mouse cardiac allografts. Conclusions— These results show that VEGFR-3 participates in immune cell traffic from peripheral tissues to secondary lymphoid organs by regulating allograft lymphatic vessel CCL21 production and suggest VEGFR-3 inhibition as a novel lymphatic vessel–targeted immunomodulatory therapy for cardiac allograft rejection and arteriosclerosis.
Background-Ischemia/reperfusion injury may have deleterious short-and long-term consequences for cardiac allografts.The underlying mechanisms involve microvascular dysfunction that may culminate in primary graft failure or untreatable chronic rejection. Methods and Results-Here, we report that rat cardiac allograft ischemia/reperfusion injury resulted in profound microvascular dysfunction that was prevented by donor treatment with peroral single-dose simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase and Rho GTPase inhibitor, 2 hours before graft procurement. During allograft preservation, donor simvastatin treatment inhibited microvascular endothelial cell and pericyte RhoA/Rho-associated protein kinase activation and endothelial cell-endothelial cell gap formation; decreased intragraft mRNA levels of hypoxia-inducible factor-1␣, inducible nitric oxide synthase, and endothelin-1; and increased heme oxygenase-1. Donor, but not recipient, simvastatin treatment prevented ischemia/reperfusion injury-induced vascular leakage, leukocyte infiltration, the no-reflow phenomenon, and myocardial injury. The beneficial effects of simvastatin on vascular stability and the no-reflow phenomenon were abolished by concomitant nitric oxide synthase inhibition with N-nitro-L-arginine methyl ester and RhoA activation by geranylgeranyl pyrophosphate supplementation, respectively. In the chronic rejection model, donor simvastatin treatment inhibited cardiac allograft inflammation, transforming growth factor-1 signaling, and myocardial fibrosis. In vitro, simvastatin inhibited transforming growth factor-1-induced microvascular endothelial-to-mesenchymal transition. Conclusions-Our results demonstrate that donor simvastatin treatment prevents microvascular endothelial cell and pericyte dysfunction, ischemia/reperfusion injury, and chronic rejection and suggest a novel, clinically feasible strategy to protect cardiac allografts. (Circulation. 2011;124:1138-1150.)Key Words: endothelium Ⅲ inflammation Ⅲ ischemia Ⅲ microcirculation Ⅲ transplantation R estoration of compromised blood flow is vital in vascular occlusion, but paradoxically, tissue reperfusion is often accompanied by significant morbidity and mortality. This is especially evident in heart transplantation in which ischemia/ reperfusion injury (IRI) may result in primary graft failure and the development of untreatable chronic rejection. [1][2][3] Clinically feasible organ preservation strategies are needed to limit early IRI, to blunt subsequent pathological immunological and tissue remodeling responses, and to prolong cardiac allograft recipient survival. Clinical Perspective on p 1150Endothelial cell (EC) dysfunction is a hallmark of IRI 4 -6 and the development of cardiac allograft fibrosis and arteriosclerosis, manifestations of chronic rejection. 2,3,7 IRI 5 and several IRIrelated factors such as hypoxia, thrombin, vascular endothelial growth factor, and RhoA GTPase activation are involved in EC-EC gap formation and compromised endothelial stability. 6,8 -10...
Diabetes mellitus is one of the most prevalent chronic diseases worldwide. Diabetic patients are at risk of developing cataract and present for surgery at an earlier age than non-diabetics. The aim of this study was to review the problems associated with cataract surgery in a diabetic patient. Corneal complications in diabetic patients include delayed wound healing, risk of developing epithelial defects or recurrent erosions due to the impairment of epithelial basement membranes and epithelial–stromal interactions. Diabetic patients present lower endothelial cell density and their endothelium is more susceptible to trauma associated with cataract surgery. A small pupil is common in diabetic patients making cataract surgery technically challenging. Finally diabetic patients have an increased risk for developing postoperative pseudophakic cystoid macular edema, posterior capsule opacification or endophthalmitis. In patients with pre-proliferative or proliferative diabetic retinopathy, diabetic macular edema or iris neovascularization adjunctive therapy such as an intravitreal anti-vascular endothelial growth factor injection, can inhibit exacerbation related to cataract surgery.
Diclofenac (DICL), as well as the combination of DEX and DICL, were superior to DEX monotherapy in minimizing CRT change and the incidence of PCME. Combination medication showed no added value compared to DICL monotherapy in uneventful cataract surgery.
Organ damage and innate immunity during heart transplantation may evoke adaptive immunity with serious consequences. Because lymphatic vessels bridge innate and adaptive immunity, they are critical in immune surveillance; however, their role in ischemia–reperfusion injury (IRI) in allotransplantation remains unknown. We investigated whether the lymphangiogenic VEGF‐C/VEGFR3 pathway during cardiac allograft IRI regulates organ damage and subsequent interplay between innate and adaptive immunity. We found that cardiac allograft IRI, within hours, increased graft VEGF‐C expression and lymphatic vessel activation in the form of increased lymphatic VEGFR3 and adhesion protein expression. Pharmacological VEGF‐C/VEGFR3 stimulation resulted in early lymphatic activation and later increase in allograft inflammation. In contrast, pharmacological VEGF‐C/VEGFR3 inhibition during cardiac allograft IRI decreased early lymphatic vessel activation with subsequent dampening of acute and chronic rejection. Genetic deletion of VEGFR3 specifically in the lymphatics of the transplanted heart recapitulated the survival effect achieved by pharmacological VEGF‐C/VEGFR3 inhibition. Our results suggest that tissue damage rapidly changes lymphatic vessel phenotype, which, in turn, may shape the interplay of innate and adaptive immunity. Importantly, VEGF‐C/VEGFR3 inhibition during solid organ transplant IRI could be used as lymphatic‐targeted immunomodulatory therapy to prevent acute and chronic rejection.
We found that alloimmune response induces PDGF-A, PDGF-C, and PDGF-D expression in the graft vasculature. PDGF-A, PDGF-C, and PDGF-D mediated profibrotic and proarteriosclerotic effects in transplanted hearts involving the TGF-beta1 pathway. Inhibition of signaling of all PDGF-ligands except that of PDGF-B may thus be needed to inhibit chronic rejection in cardiac allografts.
Purpose Multifocal intraocular lenses (MIOLs) are often discouraged in patients with or at risk of retinal disorders (including diabetic retinopathy, age-related macular degeneration, and epiretinal membranes), as MIOLs are believed to reduce contrast sensitivity (CS). Concerns with MIOLs have also been raised in individuals with visual field defects, fixation instability or eccentric preferred retinal locations. The aim of this study is to review the influence of MIOL on quality of vision in patients with retinal diseases. Methods We reviewed the PubMed and Web of Science databases to identify relevant studies using the following keywords: multifocal intraocular lens, cataract surgery, cataract extraction, lens exchange, diabetic retinopathy, age-related macular degeneration, and contrast sensitivity. Results Studies evaluating CS in MIOLs present conflicting results: MIOLs either did not influence CS or resulted in worse performance under low-illuminance conditions and higher spatial frequencies when compared to monofocal IOLs. Nevertheless, MIOLs preserved CS levels within the age-matched normal range. Two studies reported that patients with concurrent retinal diseases receiving a MIOL, both unilaterally and bilaterally, reported a significant improvement in visual-related outcomes. Individuals with a monofocal IOL in one eye and a MIOL in the fellow eye reported greater subjective satisfaction with the MIOL. Conclusion We were unable to find evidence suggesting that patients with retinal diseases should be advised against MIOLs. Nevertheless, more research is needed to address the aforementioned concerns and to optimize the use of MIOLs in eyes with retinal disease.
In diabetic patients with DME or PDR, the intravitreal levels of permeability and proangiogenic factors Ang-2 and VEGF were lower in simvastatin-treated than in those without statin medication. Moreover, the levels of MMP-9 and TGF-β1, factors involved in the breakdown of basement membrane and fibroproliferation, were lower in patients with PDR having simvastatin medication. When acetylsalicylic acid was combined with simvastatin treatment, the intraocular levels of Ang-2 and VEGF were significantly lower than in diabetics treated with simvastatin alone. These data provide a novel insight into the potential protective mechanisms underlying simvastatin medication in patients with diabetic retinopathy complications.
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