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.
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.
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.
Summary
The influence of dialysis modalities on HRQoL before and after kidney transplantation (KT) and the role of adherence to medication on HRQoL have not been fully studied. Sixty four dialysis ...patients who answered the 15D HRQoL survey during dialysis were surveyed again after KT. Adherence and employment were also investigated. The mean 15D score was highest among home hemodialysis patients (HHD) and lowest among in‐center hemodialysis patients (icHD). After KT, the mean 15D score improved significantly in 78.6% of peritoneal dialysis patients (PD), 47.6% of HHD, and 53.8% of icHD. Then, mean 15D score remained unchanged in 28.6% of HHD and in 23.1% of icHD patients. A deterioration in the 15D score occurred in 14.3% of PD, 23.1% of icHD, and 23.8% of HHD patients, and this was influenced by the number of pills (P = 0.04). Adherence to medication was the lowest in PD, timing being the most challenging task showing a connection to higher creatinine concentration (never forgot 1.41 mg/dl vs. forgot 2.08 mg/dl P = 0.05). Employed patients had a higher mean 15D score. The icHD and PD patients benefited the most from KT and HHD the least. Low pill burden and employment were linked to a better HRQoL.
Background Associations between mode of renal replacement therapy and employment rate have not been well characterized. Study Design Cross-sectional registry analysis. Setting & Participants The ...employment status of all prevalent 15- to 64-year-old dialysis and kidney transplant patients in Finland at the end of 2007 (N = 2,637) was analyzed by combining data from the Finnish Registry for Kidney Diseases with individual-level employment statistics of the Finnish government. Predictor Prevalence rate ratios (PRRs) of employment according to treatment modality with adjustment for age, sex, cause of end-stage renal disease (ESRD), duration of ESRD, and comorbid conditions were estimated using Cox regression with a constant time at risk. Outcome Employment status of patients on dialysis therapy or after transplant. Measurements Clinical data were collected from the Finnish Registry for Kidney Diseases, and employment data were acquired from Statistics Finland. Results 19% of hemodialysis patients, 31% of peritoneal dialysis patients, and 40% of patients with a functioning transplant were employed; the overall employment rate for the Finnish population aged 15-64 years is 67%. Home hemodialysis patients and those treated with automated peritoneal dialysis had employment rates of 39% and 44%, respectively. In adjusted analysis, patients on home hemodialysis therapy (PRR, 1.87), on automated peritoneal dialysis therapy (PRR, 2.14), or with a kidney transplant (PRR, 2.30) had higher probabilities of employment than in-center hemodialysis patients. Patients with type 1 or 2 diabetes as the cause of ESRD had the lowest probability of employment (PRR, 0.48-0.60 compared with glomerulonephritis). Patients aged 25-54 years more frequently were employed than those younger than 25 or older than 54 years. Sex did not predict employment. For transplant recipients, longer time since transplant was associated with higher employment in addition to the mentioned factors. Limitations Cross-sectional design. Conclusions Employment rate of home dialysis patients was similar to that of transplant recipients and higher than that of in-center hemodialysis patients. Patients with diabetes were less likely to be employed.
BACKGROUNDExpression of both platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) is increased during the development of chronic rejection which remains the major ...reason for late allograft loss in clinical kidney transplantation. Sunitinib is a tyrosine kinase inhibitor which inhibits both VEGF and PDGF receptors. Here we investigated its effect on the development of chronic rejection.
METHODSRat aortic denudation model was used to define sunitinib dose. In vitro studies were done to investigate the effect of sunitinib on smooth muscle cell proliferation and migration. Kidney transplantations were performed from dark agouti rat strain (DA) to Wistar furth rat strain rats and syngenic DA-DA grafts were used as controls. Allografts were immunosuppressed either with cyclosporine or with cyclosporine and sunitinib. Grafts were harvested at 5 and 90 days for histology and immunohistochemistry. Serum creatinine levels were measured weekly to monitor graft function.
RESULTSSunitinib decreased neointimal formation and smooth muscle cell proliferation and migration in a dose-dependent manner. Sunitinib was well tolerated and almost completely prevented chronic rejection changes and preserved significantly better renal graft function after transplantation. Sunitinib also inhibited chronic PDGF-A and -B and VEGF-A and -B expressions.
CONCLUSIONSThese results demonstrate that combined inhibition of PGDF and VEGF with sunitinib prevents chronic rejection changes in experimental kidney transplantation which indicates that sunitinib could be a potential intervention also in clinical kidney transplantation.
Summary
Lymphangiogenesis occurs in renal allografts and it may be involved in the maintenance of the alloreactive immune response and thus participate in the development of chronic kidney allograft ...injury. Sirolimus (SRL) has been shown to inhibit lymphangiogenesis. The aim of this study was to describe lymphangiogenesis and its regulation during the development of chronic kidney allograft injury and to investigate the effect of SRL on allograft lymphangiogenesis and chronic kidney allograft injury. A rat renal transplantation model was used. Allografts treated with cyclosporine A or with SRL were analyzed in various time points. Syngenic transplantations were used as controls. Kidney function was followed with serum creatinine. Histology was analyzed by Chronic Allograft Damage Index (CADI). Immunohistochemistry was used to detect lymphatic vessels, VEGF‐C and VEGFR‐3. In cyclosporine‐treated allografts VEGF‐C/VEGFR‐3 pathway was strongly upregulated leading to extensive lymphangiogenesis 60 days after transplantation. Lymphangiogenesis correlated positively with the CADI score. Sirolimus efficiently inhibited lymphangiogenesis, improved graft function and attenuated the development of chronic kidney allograft injury when compared with cyclosporine. In conclusion, lymphangiogenesis is associated with chronic kidney allograft injury and SRL is a potent inhibitor of lymphangiogenesis in renal allografts. Inhibition of lymphatic proliferation could mediate the nephroprotective properties of SRL.
BACKGROUNDChronic allograft injury remains a major problem in clinical kidney transplantation and different growth factors participate in its development. Epidermal growth factor (EGF) affects cell ...proliferation and mitogenesis through its tyrosine kinase receptor. Erlotinib is an orally administered tyrosine kinase inhibitor used in clinical oncology to inhibit EGF signaling. We investigated its effect on the development of chronic allograft injury in an experimental kidney transplantation model.
METHODSKidney transplantations were performed between Dark Agouti and Wistar Furth rats. Recipients were immunosuppressed either with cyclosporine A (CsA, 1.5 mg/kg/day subcutaneously) or with CsA and erlotinib (10 mg/kg/day orally). Kidney grafts were harvested after 5 and 90 days for histology and immunohistochemistry. Aorta denudation model was used for the erlotinib dose response study to define the optimal dose for the transplantation study.
RESULTSEpidermal growth factor expression was increased in CsA-treated allografts which developed intense chronic changes on day 90. Erlotinib ameliorated neointimal formation in the dose response study. In addition, erlotinib decreased chronic rejection changes and maintained better graft function in kidney transplantation model. Late posttransplant EGF and EGF receptor levels were reduced with erlotinib.
CONCLUSIONBased on these findings, EGF mediates in part the development of chronic allograft injury. Its inhibition with erlotinib prevents chronic rejection and maintains better allograft function. Therefore, EGF blocking by erlotinib provides a novel pathway to prevent chronic allograft injury.
Background
Mesangial proliferative glomerulonephritis is a common glomerular disorder that may lead to end-stage renal disease. Epidermal growth factor (EGF) plays an important role in the regulation ...of cell growth, proliferation, and differentiation and in the pathology of various renal diseases. Erlotinib is a novel, oral, highly selective tyrosine kinase inhibitor of the EGF receptor. It is clinically used to treat non-small cell lung and pancreatic cancers. Here, we investigated the effect of erlotinib on the progression of mesangioproliferative glomerulonephritis in an experimental model.
Methods
Mesangial glomerulonephritis was induced with anti-rat Thy-1.1 antibody in male Wistar rats weighing 150–160 g. Rats were treated with erlotinib (10 mg/kg/day p.o.) or vehicle only (polyethylene glycol). Native Wistar rat kidneys were used as histological controls. Serum creatinine levels were measured at day 7. Kidneys were harvested 7 days after antibody administration for histology.
Results
Native controls showed no histological signs of glomerular pathology. In the vehicle group, intense glomerular inflammation developed after 7 days and prominent mesangial cell proliferation and glomerular matrix accumulation was seen. Erlotinib was well tolerated and there were no adverse effects during the follow-up period. Erlotinib significantly prevented progression of the glomerular inflammatory response and glomerular mesangial cell proliferation as well as matrix accumulation when compared with the vehicle group. Erlotinib also preserved renal function.
Conclusion
These results indicate that erlotinib prevents the early events of experimental mesangial proliferative glomerulonephritis. Therefore, inhibition of the EGF receptor with erlotinib could prevent the progression of glomerulonephritis also in clinical nephrology.
Viral impact on long-term kidney graft function Helanterä, Ilkka; Egli, Adrian; Koskinen, Petri ...
Infectious disease clinics of North America,
06/2010, Letnik:
24, Številka:
2
Journal Article
Recenzirano
Acute rejection episodes are an important risk factor for the functional deterioration of solid-organ transplants. With more intense immunosuppressive protocols, the rate of acute rejection episodes ...has significantly declined in the last decade, but long-term graft function and graft survival are challenged by increasing viral complications. In this article, recent data on the role of adenovirus, polyomavirus BK and JC, cytomegalovirus, human herpesvirus-6 and -7, and parvovirus B19 on the long-term outcome of kidney transplantation are reviewed. An update on the pathophysiology of smoldering viral replication, associated inflammatory damage, and the presumed indirect viral effects is provided, and the implications for diagnostic tests and antiviral intervention are discussed.
Ischemia-reperfusion injury (IRI) and innate immune response augment adaptive immunity and may also trigger repair processes that lead to uncontrolled fibrosis and atherosclerosis as seen in chronic ...allograft injury. Simvastatin has been shown to protect from renal IRI in several experimental studies. The aim of this study was to examine the effect of donor simvastatin pretreatment and early initiation of recipient simvastatin treatment on chronic kidney allograft injury.
A rat renal transplantation model was used. Simvastatin was administered perorally for donor (5 mg/kg) and/or for recipient (2 mg/kg) 2 hours before transplantation and/or as daily treatment starting on the first postoperative day (2 mg/kg/day). The study included 5 groups: (1) no simvastatin, (2) donor pretreatment, (3) daily recipient treatment, (4) donor pretreatment + daily recipient treatment and (5) donor pretreatment + recipient pretreatment + daily recipient treatment. The grafts were recovered at day 90 for histopathological and immunohistochemical analysis. Kidney function was followed weekly with serum creatinine, and 24-hour urine protein was measured 60 and 90 days after transplantation.
We found that donor and recipient simvastatin pretreatment combined with daily recipient treatment reduced graft inflammation and chronic allograft injury. Treatment using only statins started after transplantation reduced inflammation to some extent, but did not affect chronic kidney allograft injury. Pretreatment using only donor statins impaired graft function and increased proteinuria.
Our data suggest that perioperative recipient statin treatment reduces inflammation and may protect the graft in the long term.
Objective— Chronic rejection is the main reason for the poor long-term survival of heart transplant recipients and is characterized by cardiac allograft inflammation, fibrosis, and arteriosclerosis. ...We examined the specific roles of different platelet-derived growth factor (PDGF) ligands (A–D)—potent mesenchymal cell mitogens—in rat cardiac allografts. Methods and Results— PDGFR-α mRNA was upregulated in acutely-rejecting, and PDGF-A and PDGF-C mRNA in chronically-rejecting cardiac¢hatn allografts. In acute rejection, PDGFR-α immunoreactivity increased in the media of arteries. In chronically-rejecting allografts, immunoreactivity of all PDGF ligands and receptors—except that of PDGF-B ligand—was found in the intima of arteries, and the expression of PDGF-A and PDGF-C was seen in cardiomyocytes. Intracoronary adeno-associated virus-2 (AAV2)-mediated PDGF-A and -D gene transfer enhanced cardiac allograft inflammation. AAV2-PDGF-A, AAV2-PDGF-C, and AAV2-PDGF-D significantly upregulated profibrotic TGF-β1 mRNA and accelerated cardiac fibrosis and arteriosclerosis. In contrast, AAV2-PDGF-B did not aggravate chronic rejection. Conclusions— 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-β1 pathway. Inhibition of signaling of all PDGF-ligands except that of PDGF-B may thus be needed to inhibit chronic rejection in cardiac allografts.
Alloimmune response induces PDGF-A, PDGF-C, and PDGF-D in the graft vasculature, and overexpression of these ligands upregulates TGF-β1 mRNA and enhances cardiac fibrosis and arteriosclerotic changes in cardiac allografts. Our results suggest that inhibition of signaling of all PDGF ligands except that of PDGF-B may be needed to inhibit chronic rejection in cardiac allografts.
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