Jochen W.U. Fries

Poor Cell Survival Limits the Beneficial Impact of Mesenchymal Stem Cell Transplantation on Acute Kidney Injury

Background: Although renal tubular epithelium has a great capacity for repair it has been suggested that the administration of mesenchymal stem cells may accelerate the recovery following severe ischemic injury. Methods: Here we analyzed the survival rate and organ distribution of transplanted mesenchymal stem cells as well as their contribution to kidney regeneration after ischemic renal injury using functional tests, histological examination as well as quantitative real-time PCR. Results: Intravenously injected stem cells were mainly trapped in lungs and liver. One hour after injection, less than 1% of the injected stem cells could be detected in the injured kidneys. These cells disappeared within the first few days and did not replace renal epithelial cells precluding substantial transdifferentiation. To clarify whether reinforced stem cell delivery might promote sustained survival or conversion to tubular epithelia, stem cells were directly injected into the injured kidneys. Although these grafted cells also did not show sustained survival or contribute to structural renal repair, stem cell injection was associated with a significant but transient initial decrease in serum creatinine. Conclusion: These data suggest that mesenchymal stem cells do not significantly contribute to epithelial renewal after ischemic injury, promoting the idea that the major impact of cell-based therapy for acute kidney injury may result from paracrine or endocrine effects unrelated to stem cell transdifferentiation.

Role of balloon occlusion for mononuclear bone marrow cell deposition after intracoronary injection in pigs with reperfused myocardial infarction

AIMSnIn clinical studies on cell therapy for acute myocardial infarction (MI), cells are usually applied by intracoronary infusion with balloon (IC/B). To test the utility of balloon occlusion, mononuclear bone marrow cell (MNC) retention after intracoronary infusion without balloon (IC/noB) was compared with IC/B and intramyocardial (IM) injection.nnnMETHODS AND RESULTSnFour hours after LAD ligation in male pigs, reperfusion was allowed (confirmed by coronary angiography). Five days later, 1 x 10(8) autologous (111)Indium-labelled MNC were injected IC/noB (n = 4), IC/B (n = 4), or IM (n = 4). At 1 h the fraction of injected MNC that was detected in the heart was 4.1 +/- 1.1% after IC/noB injection, 6.1 +/- 2.5% after IC/B injection (P = 0.19), and 20.7 +/- 2.3% after IM injection (P < 0.001 vs. IC/noB and IC/B). At 24 h it was 3.0 +/- 0.6% (IC/noB), 3.3 +/- 0.5% (IC/B, P = 0.43), and 15.0 +/- 3.1% (IM, P < 0.001 vs. IC/noB and IC/B). Dynamic scintigrammes during each of four consecutive IC/B injections showed a rapid 19.6 +/- 8.0% cell loss during balloon inflation (no-flow period, phase 1) and a rapid 36.6 +/- 17.8% cell loss after balloon deflation (re-flow period, phase 2). After each of four consecutive IC/noB injections the peak cell deposit was lower, followed by one phase of rapid cell loss (30.9 +/- 11.0% after 6 min). After IM injection only a slow linear cell loss was observed (9.7% per h). In histology, PKH-67 labelled cells only rarely had passed the endothelial barrier after 24 h after IC injection, while they were exclusively found in the interstitium after IM injection.nnnCONCLUSIONnThe observation of a similar cell persistence after IC injections with and without balloon occlusion suggests that the balloon procedures currently applied in clinical studies are not necessary for cell deposit. If longer term persistence of cells plays a role for the clinical benefit of cardiac cell therapy, IM injection may be superior to IC applications.

Living donor kidney transplantation from relatives with mild urinary abnormalities in Alport syndrome: long-term risk, benefit and outcome

BACKGROUNDnAlport syndrome is a hereditary nephropathy leading to renal failure during adolescence. This study evaluates the outcome of living donor transplantation (Tx) from heterozygous mothers to their affected children.nnnMETHODSnSeven mothers were evaluated, and donation was refused in one because of proteinuria.nnnRESULTSnAll of the remaining six donors had microhaematuria, and one had proteinuria. Renal function was monitored after Tx (average 6.7 years in donors and 5.3 years in acceptors). Three of six donors developed new onset hypertension, and two new onset of proteinuria. Renal function declined significantly in four donors: (1) -35% after 2 years; (2) -25% after 3 years; (3) -30% after 4 years and (4) -60% after 14 years versus before Tx. However, creatinine clearance remained >40 ml/min in all donors. All transplanted kidneys worked well 1 and 5 years after Tx, and one failed after 10 years. One patient died from meningitis, and the remaining four remained stable.nnnCONCLUSIONnLiving donor Tx from relatives in Alport families is an ambivalent option. Proteinuria should be an exclusion criterion. Yet, even in donors with isolated microhaematuria, families and their physicians should be aware of an increased risk of renal failure in donor and recipient. This risk might be minimized by careful donor evaluation including biopsy and nephroprotective strategies after Tx in both donor and recipient.

Endothelin-1 Induces NF-κB via Two Independent Pathways in Human Renal Tubular Epithelial Cells

Background: Endothelin-1 (ET-1) is a major transcriptional activator of renal proximal tubule cells acting in an autocrine and paracrine manner. In animal studies, ET-1 has been implicated in progressive renal interstitial fibrosis by promoting gene expression, possibly via the inflammatory NF-ĸB signal pathway. While ET-1-dependent mechanisms of signal transduction have been studied mainly in tumor cell lines, we analyzed the mechanism of ET-1-induced, NF-ĸB-mediated target gene activation in proximal tubule cells. Methods: Human renal proximal tubule cells were stimulated with ET-1 and gene expression analyzed by protein microarray, Western blot, non-radioactive electromobility shift assay, and quantitative real-time polymerase chain reaction. Results: Activation of NF-ĸB occurs only via an ET-1-specific type A receptor (not type B as in animals). Induction can be blocked by bosentan, and endothelin-A but not endothelin-B receptor-specific antagonists. Protein microarray screening shows activation of two independent cascades (via the endothelin-A receptor, or via diacylglycerol) leading to NF-ĸB induction. The independent induction is also reflected by target gene expression such as the vascular cell adhesion molecule-1, interleukin-6, and fractalkine at different time points. Conclusion: Thus prohibiting ET-1-mediated gene transcription necessitates blocking of NF-ĸB and diacylglycerol signal transduction in proximal tubule cells.

Soluble Tissue Factor Induces Coagulation on Tumor Endothelial Cells In Vivo if Coadministered With Low-Dose Lipopolysaccharides

Objective—This study was performed to evaluate the mechanisms leading to tumor vessel occlusion by tissue factor–based drugs, which are used in vascular targeting approaches for the treatment of malignant tumors. Methods and Results—The effects of nontargeted soluble tissue factor were evaluated in vitro and in vivo. Tumor-bearing mice were treated with (1) the extracellular portion of tissue factor (soluble tissue factor), (2) low nontoxic doses of lipopolysaccharides, or (3) a combination thereof. The combination treatment showed the best effects and resulted in selective thrombosis of tumor vessels. On the basis of our data from subsequent in vitro analyses, including surface plasmon resonance measurements and endothelial cell based coagulation assays, we propose a model on how soluble tissue factor, although lacking its membrane anchor, can promote selective tumor vessel occlusion. Conclusions—To our knowledge, this is the first report to describe the molecular mechanisms of coagulation induction by untargeted soluble tissue factor in vivo. Combination treatments including soluble tissue factor might represent an alternative vascular targeting approach for the treatment of malignant tumors.

Differential effects of red and white wines on inhibition of the platelet-derived growth factor receptor: impact of the mash fermentation.

AIMSnModerate wine consumption is associated with a significant reduction of cardiovascular mortality. The molecular basis of this phenomenon remains unknown. Platelet-derived growth factor (PDGF) is an important contributor to atherogenesis. We investigated the effects of selected red and white wines on PDGF receptor (PDGFR) signalling in rat and human vascular smooth muscle cells (VSMCs).nnnMETHODS AND RESULTSnAll red wines concentration dependently inhibited the ligand-induced tyrosine phosphorylation of the PDGFR, downstream signalling events such as mitogen activated protein (MAP) kinase activation (Erk 1/2) and induction of immediate early genes (Egr-1, c-fos), and PDGF-induced cellular responses, whereas all white wines had no effect. At concentrations achieved after wine consumption in humans, all red wines completely abolished PDGF-dependent VSMC proliferation and migration. Red wines also inhibited PDGFR phosphorylation in vascular tissue, and in human coronary smooth muscle cells. Quantitative analyses of all tested wines and of samples collected at various time points (Days 0-16) of the mash fermentation, which is only performed for red wine, revealed that flavonoids of the catechin family, which potently inhibit PDGFR signalling, are extracted from grape seeds and skins during this process and therefore accumulate specifically in red wine. The accumulation of flavonoids correlated with the inhibitory potency of red wines on PDGFR signalling. Furthermore, this procedure could be imitated by incubation of wines with shredded grape seeds, and flavonoid-enriched white wine inhibited the PDGFR as potently as red wines.nnnCONCLUSIONnOnly red wines abrogate a critical pathogenic mechanism during atherogenesis, PDGFR signalling, in VSMCs. This effect is mediated by non-alcoholic constituents, which accumulate during the mash fermentation. Our findings offer a molecular explanation for the vasoprotective effects particularly of red wine. Therefore, future epidemiological studies should consider differential protective effects of red and white wine in vivo.

Coronary oxygen persufflation for heart preservation in pigs: analyses of endothelium and myocytes.

Background. Coronary oxygen persufflation (COP) has been shown to prolong heart preservation time up to 14 hr in a mature pig model, with excellent recovery after orthotopic transplantation. The aim of the present study was to assess the structural, metabolic, and functional myocardial and endothelial integrity after COP in mature pig hearts. Methods. Cardioplegic arrest was induced by original crystalloid Bretschneider solution (HTK 3h, n=6), modified Bretschneider solution (mHTK+COP, n=6), or University of Wisconsin solution (UW+COP, n=6). Hearts were stored for 3 (HTK 3h) or 14 hr (mHTK+COP, UW+COP) at 0° to 1°C. In addition, COP hearts were persufflated. After heterotopic transplantation and reperfusion for 7 days, hearts were analyzed by light microscopy or electron microscopy for structural injuries. Endothelial function, cardiac enzymes, metabolic parameters, and myocardial water content (MWC) were determined. Six recipient hearts served as controls. Results. Quantitative light microscopic analyses and semiquantitative electron microscopic analyses showed an equal amount of damage in all groups including HTK 3h hearts. No rejection was observed. Substance P induced an equal dilatation in all hearts. Serum levels of cardiac enzymes were similar in all groups, but energy-enriched phosphates were significantly reduced, and MWC was augmented in the HTK 3h hearts and in the UW+COP hearts, in contrast to the mHTK+COP transplants. Conclusions. The lack of structural defects related to the COP technique, similar endothelial function, and an even better metabolic state of the mHTK+COP hearts versus HTK 3h hearts demonstrate the efficacy of the COP technique for prolongation of myocardial preservation time up to 14 hr.

Hypereosinophilic syndrome associated with acute necrotizing myocarditis and cardiomyopathy.

Wir berichten über eine 55-jährige Patientin mit einer ausgeprägten eosinophilen Myokarditis und hochgradig eingeschränkter linksventrikulärer Pumpfunktion. Klinisch manifestierte sich die Erkrankung mit reduziertem Allgemeinzustand, zunehmender Belastungsdyspnoe und peripheren Ödemen. Im Blutbild fand sich eine Leukozytose mit ausgeprägter peripherer Eosinophilie (48,8%). Eine endomyokardiale Biopsie zeigte eine massive Infiltration des Myokards mit eosinophilen Granulozyten und Nekrosen. Die Symptome und Laborparameter sprechen am ehesten für ein hypereosinophiles Syndrom. Die Differentialdiagnose eines Churg-Strauss-Syndroms wird diskutiert. Es wurde eine leitliniengerechte medikamentöse Herzinsuffizienztherapie sowie immunsuppressive Therapie mit Prednisolon (Decortin H®, 1,5 mg/kgKG) eingeleitet. Darunter lies sich eine rasche Reduktion der eosinophilen Granulozyten mit Normalisierung des peripheren Blutbildes beobachten, was mit einer deutlichen Verbesserung der klinischen Symptomatik korrelierte. Insbesondere war eine signifikante Zunahme der linksventrikulären Pumpfunktion zu beobachten. Nach langsamer Dosisreduktion auf eine Erhaltungsdosis von 10 mg Prednisolon blieben das klinische Beschwerdebild und Blutbild im Verlauf stabil. We report the rare case of a 55-year-old female with massive eosinophilic myocarditis and severe, however reversible, impairment of left ventricular function. The patient presented with reduced physical condition, progressive dyspnea on exertion and peripheral edema. The white blood count revealed a leukocytosis and markedly elevated peripheral blood eosinophilics (48.8%). An endomyocardial biopsy demonstrated massive myocardial infiltration with eosinophilic granulocytes and necrosis. The symptoms and laboratory parameters indicate the presence of a hypereosinophilic syndrome. The differential diagnosis of a Churg-Strauss syndrome is discussed. Medical heart failure treatment according to international guidelines and an immunosuppressive treatment with prednisolone (Decortin H® 1.5 mg/kgBW) were initiated. This therapy led to a dramatic reduction of the eosinophilic granulocyte count and normalization of the peripheral blood count, which correlated with a significant improvement of clinical symptoms. Consistently, an increase of left-ventricular function was observed. Upon successive dose reduction to a maintenance dosage of 10 mg prednisolone, the patient’s clinical status and peripheral blood count remained stable.

Segmental Arterial Mediolysis in a Preterm

We firstly report on a dystrophic preterm infant with segmental arterial mediolysis (SAM) found in arteries of placental, umbilical and cerebral tissues. These arterial lesions of unknown etiology developing in the elderly are characterized by segmental lysis of the abdominal splanchnic arteries followed by aneurysms and acute bleeding. Typically, the lesions occur in a skip pattern. We could find a small number of SAM in the spleen but much more in placental and umbilical tissues. Rarely, a vascular elastosis and splitting of individual vessels in the spleen and lung could be detected. The histological findings are similar to that of adult patients.

Glomeruläre Proteinurie bei Hantavirus-Nephritis

Zusammenfassung.Hintergrund:Infektionen mit dem Hantavirus-Subtyp Puumala sind durch ein schweres Krankheitsgefühl, Fieber, Flankenschmerzen und Sehstörungen charakterisiert. Sie lösen eine tubulointerstitielle Nephritis aus, die zum akuten Nierenversagen führt.Fallbeschreibungen:Bei vier Patienten mit Hantavirus-Nephritis und akutem Nierenversagen wurde die Proteinurie mittels Mikroelektrophorese untersucht, um mögliche Ursachen des renalen Eiweißverlusts näher zu charakterisieren. Die Patienten (drei Männer, eine Frau) stellten sich mit Fieber, Kopf- und Flankenschmerzen und einem akuten Nierenversagen vor (sonographisch vergrößerte Nieren, Serumkreatinin 7,7/3,4/3,2/7,8 mg/dl, Proteinurie 1,7/0,5/1,5/9,0 g/l, positiver IgM-Antikörper-Nachweis gegen Hantavirus, Subtyp Puumala). Die Mikroelektrophorese der Urine zeigte bei allen Patienten eine große Fraktion höhermolekularer Proteine wie Transferrin und Immunglobuline als Hinweis auf eine unselektive glomeruläre Proteinurie. Histologisch zeigten die drei durchgeführten Nierenbiopsien eine normale Morphologie der Glomeruli und der Gefäße. Tubulointerstitiell lagen hämorrhagische Einblutungen und eine Infiltration mononukleärer Zellen vor. Nach 14 Tagen hatte sich die Nierenfunktion bei allen Patienten normalisiert. Eine persistierende Proteinurie entwickelte sich nicht.Schlussfolgerung:Die Hantavirus-Nephritis kann zu einer glomerulären Proteinurie führen. Die normale glomeruläre Morphologie und ein rascher Rückgang der Proteinurie weisen auf eine transiente Schädigung der glomerulären Filtrationsbarriere hin. Möglicherweise wird die vorübergehende glomeruläre Permeabilitätssteigerung durch die immunologische Auseinandersetzung mit dem Virus verursacht.Abstract.Background:Infection with hantavirus of the Puumala type is known to cause severe illness, fever, loin pain and impaired vision. Tubulointerstitial nephritis leads to acute renal failure.Case Reports:In four patients presenting with hantavirus infection and acute renal failure, proteinuria was analyzed by microelectrophoresis to explore possible causes of renal protein loss in hantavirus nephritis. The patients (three men, one woman) presented with a short history of fever, headache, loin pain and acute renal failure (enlarged kidneys in ultrasonography, serum creatinine 7.7/3.4/3.2/7.8 mg/dl, urinary protein excretion 1.7/0.5/1.5/9.0 g/l, IgM antibodies against hantavirus positive in all patients, subtype Puumala). Microelectrophoresis of the urine revealed a major fraction of higher molecular weight proteins such as transferrin and immunoglobulins indicating unselective glomerular-type proteinuria in all four patients. In three renal biopsy specimens obtained, morphology of glomeruli and vasculature was normal as judged by light microscopy. The tubulointerstitium exhibited interstitial hemorrhage and round-cell infiltrates. After 2 weeks, renal function had completely recovered in all patients and no persistent proteinuria developed.Conclusion:Hantavirus nephritis may lead to glomerular-type proteinuria. Glomerular morphology may be normal and proteinuria may cease within 2 weeks indicating a transient lesion of the glomerular filtration barrier. Transiently increased glomerular permeability may be caused by an immunologic response to virus infection.