A host receptor enables type 1 pilus-mediated pathogenesis of Escherichia coli pyelonephritis.

Type 1 pili have long been considered the major virulence factor enabling colonization of the urinary bladder by uropathogenic Escherichia coli (UPEC). The molecular pathogenesis of pyelonephritis is less well characterized, due to previous limitations in preclinical modeling of kidney infection. Here, we demonstrate in a recently developed mouse model that beyond bladder infection, type 1 pili also are critical for establishment of ascending pyelonephritis. Bacterial mutants lacking the type 1 pilus adhesin (FimH) were unable to establish kidney infection in male C3H/HeN mice. We developed an in vitro model of FimH-dependent UPEC binding to renal collecting duct cells, and performed a CRISPR screen in these cells, identifying desmoglein-2 as a primary renal epithelial receptor for FimH. The mannosylated extracellular domain of human DSG2 bound directly to the lectin domain of FimH in vitro, and introduction of a mutation in the FimH mannose-binding pocket abolished binding to DSG2. In infected C3H/HeN mice, type 1-piliated UPEC and Dsg2 were co-localized within collecting ducts, and administration of mannoside FIM1033, a potent small-molecule inhibitor of FimH, significantly attenuated bacterial loads in pyelonephritis. Our results broaden the biological importance of FimH, specify the first renal FimH receptor, and indicate that FimH-targeted therapeutics will also have application in pyelonephritis.

DNA in fresh urine supernatant is not affected by additional centrifugation and is protected against deoxyribonuclease.

Urinary DNA is widely studied as a non-invasive marker for monitoring of kidneys after transplantation or the progression of urinary tract tumors. The quantity of urinary DNA especially of mitochondrial origin has been reported to mirror kidney damage in various renal diseases and their models. Processing of samples might affect urinary DNA concentrations but the details are not clear. Samples of urine were collected from fifteen healthy volunteers. DNA was extracted from the whole urine, but also from the supernatant after centrifugation at 1600 g and 16000 g. In addition, we have analyzed the DNA in the microparticles in the pellet after the last spin. DNA was measured using fluorometry and real time PCR targeting nuclear and mitochondrial sequences. Addition of deoxyribonuclease to aliquots of samples enabled the characterization of DNA protection. Centrifugation at 1600 g decreased the concentration of extracted DNA by 66% at least in samples with higher DNA in whole urine. Interestingly, the additional spin at 16000 g did not result in a significant decrease in DNA concentration in the supernatant despite detectable microparticle-associated DNA. Deoxyribonuclease decreases total and nuclear DNA by 26% and 31% in whole urine. The majority of urinary mitochondrial DNA seems to be protected against deoxyribonuclease. Our results indicate high variability in urinary DNA even in healthy probands. Extracellular urinary DNA is partially bound to cell debris or microparticles, but a considerable part is still in the supernatant and is protected against cleavage. Further research should identify the nature of the protection, especially for mitochondrial DNA. Better understanding of the biology of urinary DNA should help its clinical interpretation.

Plasmatic apelin shows a promising potential as a screening biomarker for atrial fibrillation.

OBJECTIVES: Purpose of this study was to evaluate properties of apelin, a peptide detectable in peripheral blood, for atrial fibrillation (AF) detection in a diverse population of patients covering a broad spectrum from healthy to polymorbid patients. BACKGROUND: AF is the most common cardiac arrhythmia with constantly increasing incidence and prevalence. Currently available diagnostic tools do not provide sufficient detection rate. Large proportion of patients with AF remains undiagnosed and the possibility of screening at-risk groups would be significantly beneficial. METHODS: We designed this study as a multi-centre retrospective study. Study population included 183 patients. 64 in non-AF and 119 in AF group. RESULTS: Apelin plasma concentration was significantly lower in AF group compared to non-AF group (p < 0.001). Receiver operating characteristic analysis of apelin as a predictor of AF scored area under the curve of 0.79, sensitivity = 0.941 and specificity = 0.578. Multivariate analysis using logistic regression adjusted for age, BMI, apelin, dilated LV, dilated LA, arterial hypertension, and gender showed only apelin and age to be statistically significant contributors for AF. CONCLUSION: Apelin might be a promising biomarker for detecting AF in our study population. These results suggest promising potential of apelin as a screening biomarker for AF (Tab. 2, Fig. 1, Ref. 46). Text in PDF www.elis.sk Keywords: biomarker, apelin, arrhythmia, atrial fibrillation.

On the role of sex steroids in biological functions by classical and non-classical pathways. An update.

The sex steroid hormones (SSHs) play several roles in regulation of various processes in the cardiovascular, immune, muscular and neural systems. SSHs affect prenatal and postnatal development of various brain structures, including regions associated with important physiological, behavioral, cognitive, and emotional functions. This action can be mediated by either intracellular or transmembrane receptors. While the classical mechanisms of SSHs action are relatively well examined, the physiological importance of non-classical mechanism of SSHs action through membrane-associated and transmembrane receptors in the brain remains unclear. The most recent summary describing the role of SSHs in different body systems is lacking. Therefore, the aim of this review is to discuss classical and non-classical signaling pathways of testosterone and estradiol action via their receptors at functional, cellular, tissue level and to describe the effects on various body systems and behavior. Particular emphasis will be on brain regions including the hippocampus, hypothalamus, frontal cortex and cerebellum.

ZDF (fa/fa) rats show increasing heterogeneity in main parameters during ageing, as confirmed by biometrics, oxidative stress markers and MMP activity.

NEW FINDINGS: What is the central question of this study? The aim was to characterize Zucker diabetic fatty [ZDF (fa/fa)] rats and two control strains [Wistar and lean ZDF (fa/+) rats] during ageing. What is the main finding and its importance? Zucker diabetic fatty (fa/fa) rats with lower glycaemia have higher body and left ventricular weights and lower plasma gelatinase activity compared with hyperglycaemic rats. Given that type 2 diabetes is a heterogeneous metabolic disorder, the inhomogeneity of ZDF (fa/fa) rats might be beneficial in the study of its different aspects. Our experiments might promote a discussion regarding suitable normoglycaemic control animals for aged ZDF (fa/fa) rats, especially in experiments focused on myocardial tissue. ABSTRACT: Zucker diabetic fatty [ZDF (fa/fa)] rats, which are an animal model for the study of type 2 diabetes, are considered as a uniform group in most experimental studies; however, there are indications of their increasing inhomogeneity over time. The main objective of our study was to monitor biometric and biochemical parameters of ZDF (fa/fa) rats during their development of type 2 diabetes and compare them with two control strains [Wistar and lean ZDF (fa/+) rats]. According to fasting glycaemia, ZDF (fa/fa) rats were split arbitrarily into two phenotypes: obese, ZDF (fa/fa) FAT; and diabetic, ZDF (fa/fa) DIA. Glycaemia increased progressively only in the ZDF (fa/fa) DIA animals, which also exhibited higher cholesterol levels compared with ZDF (fa/fa) FAT animals. In addition, ZDF (fa/fa) FAT rats revealed more pronounced left ventricular hypertrophy and higher body weight, differentiating them from ZDF (fa/fa) DIA rats. We also investigated the activity of matrix metalloproteinases (MMPs), which are multifunctional enzymes involved in tissue remodelling. Rats in the ZDF (fa/fa) FAT group revealed lower plasma MMP2 and MMP9 activity compared with the ZDF (fa/fa) DIA group. However, increased myocardial MMP2 activity indicated left ventricular remodelling in both ZDF phenotypes. Given that type 2 diabetes in humans is a heterogeneous metabolic disorder, the heterogeneity of ZDF (fa/fa) rats might be beneficial in the study of different aspects of this pathology. Moreover, Wistar rats could serve as a more appropriate control for aged ZDF (fa/fa) rats than the commonly used ZDF fa/+ rats, which showed an increase in left ventricular weight, carbonyl stress markers in the left myocardium and MMP2 activity in both ventricles, indicating heart remodelling processes compared with the Wistar control group.

Dynamics of Plasma and Urinary Extracellular DNA in Acute Kidney Injury.

Early and reliable markers of acute kidney injury (AKI) are essential. One such candidate marker of tissue damage is extracellular DNA (ecDNA). The aim of our present study is to describe the unknown dynamics of ecDNA in an animal model of AKI. Glycerol-induced nephropathy was used to model AKI in adult male Wistar rats (n = 93). Blood and urine samples were collected 1, 3, and 24 h after model induction. Total ecDNA and its sub-cellular origin was assessed. In the plasma, total ecDNA and nuclear ecDNA were significantly increased in the AKI group already after 1 h (160% and 270%, respectively, p = 0.02 and p = 0.04). Both nuclear and mitochondrial ecDNA were higher after 3 h (180% and 170%, respectively, p = 0.002 and p = 0.005). Urinary ecDNA concentrations in the AKI group were significantly increased only 24 h after model induction (130% for total ecDNA, p = 0.009; 210% for nuclear ecDNA, p = 0.02; and 200% for mitochondrial ecDNA, p = 0.0009). Our results indicate that plasma ecDNA has the potential to serve as an early and sensitive, albeit non-specific marker of AKI. Further studies should elucidate the source of ecDNA and the dynamics of ecDNA in other animal models of AKI and patients with AKI.

Salivary changes in oxidative stress related to inflammation in oral and gastrointestinal diseases.

OBJECTIVES: The early diagnosis and monitoring of Crohn's disease (CD) and orofacial granulomatosis (OFG) might be facilitated by assaying potential disease biomarkers in saliva. Markers of oxidative stress and inflammation were assayed in salivas from patients with CD, OFG and concurrent OFG and CD (OFG + CD). SUBJECTS: Unstimulated whole mouth saliva was collected from 93 subjects, and immunoglobulin A (IgA), lactoferrin (LF) and myeloperoxidase (MPO) were determined by ELISA. Markers of oxidative stress and antioxidant status were assayed spectrophotometrically. RESULTS: Immunoglobulin A was significantly (p < .03) higher in experimental groups vs the control group. LF was significantly (p < .01) higher in OFG + CD compared to CTRL and CD. Ferric reducing antioxidant power was lower (p ≤ .009) in all experimental groups, and advanced glycation end products were higher (p ≤ .01) in CD and OFG + CD patients. CONCLUSION: Oxidative stress is increased in saliva in CD and OFG. Although MPO, a product of inflammatory cells, was not significantly increased, the other innate immune markers, IgA and LF, which are also secreted by salivary glands, were increased. This study suggests that saliva might be utilized in monitoring CD and OFG but further longitudinal studies focused on analysing a panel of salivary markers are needed.

The Effect of Melatonin on Periodontitis.

BACKGROUND: Periodontitis is a chronic disease with a complex etiology that includes bacterial colonization, excessive inflammation, and oxidative stress. The hormone melatonin has antioxidant properties and might contribute to alleviating chronic conditions by reducing oxidative stress. The aim of this study was to analyze the effect of exogenous melatonin on periodontitis in an animal model of the disease as well as in patients with periodontitis. METHODS: In rats with ligature-induced periodontitis, melatonin was administered in drinking water for two weeks. In the human study, patients with treatment-resistant periodontitis were asked to rinse their mouths with a solution containing melatonin or placebo every evening for two weeks. Periodontal status as well as salivary markers of oxidative stress were assessed at the end of the study. RESULTS: Neither radiography nor µCT revealed any significant effects of melatonin on alveolar bone loss. Gum recession was the only improved macroscopic measure in rats (p < 0.05). Analysis of salivary markers of oxidative stress revealed no effects of treatment in rats or humans despite clearly elevated melatonin concentrations in melatonin treated groups. CONCLUSION: Our results do not support the use of melatonin for the treatment of periodontitis. However, the negative outcome is limited by the short duration of the study and the chosen route of application as well as the dose of melatonin.

Beneficial Effect of Quercetin on Erythrocyte Properties in Type 2 Diabetic Rats.

Diabetes mellitus is characterized by tissue oxidative damage and impaired microcirculation, as well as worsened erythrocyte properties. Measurements of erythrocyte deformability together with determination of nitric oxide (NO) production and osmotic resistance were used for the characterization of erythrocyte functionality in lean (control) and obese Zucker diabetic fatty (ZDF) rats of two age categories. Obese ZDF rats correspond to prediabetic (younger) and diabetic (older) animals. As antioxidants were suggested to protect erythrocytes, we also investigated the potential effect of quercetin (20 mg/kg/day for 6 weeks). Erythrocyte deformability was determined by the filtration method and NO production using DAF-2DA fluorescence. For erythrocyte osmotic resistance, we used hemolytic assay. Erythrocyte deformability and NO production deteriorated during aging-both were lower in older ZDF rats than in younger ones. Three-way ANOVA indicates improved erythrocyte deformability after quercetin treatment in older obese ZDF rats only, as it was not modified or deteriorated in both (lean and obese) younger and older lean animals. NO production by erythrocytes increased post treatment in all experimental groups. Our study indicates the potential benefit of quercetin treatment on erythrocyte properties in condition of diabetes mellitus. In addition, our results suggest potential age-dependency of quercetin effects in diabetes that deserve additional research.

Age- and Phenotype-Dependent Changes in Circulating MMP-2 and MMP-9 Activities in Normotensive and Hypertensive Rats.

Matrix metalloproteinases (MMPs) are important in the pathogenesis of numerous diseases. The present study aimed to monitor the activation of MMP-2 and MMP-9 in spontaneously hypertensive rats (SHR) and their normotensive counterparts-Wistar-Kyoto rats (WKY). The animals were divided according to age (7, 20, and 52 weeks) and phenotype into: WKY-7, WKY-20, WKY-52, SHR-7, SHR-20 and SHR-52 groups. MMP plasma activities were determined by gelatine zymography. We monitored selected parameters of oxidative stress and antioxidant status. N-terminal pro-brain natriuretic peptide (NT-proBNP) was determined as a marker of heart function and neurohumoral activation. SHR-7 showed higher MMP-2 activity compared with WKY-7, while SHR-52 showed lower MMP-2 and MMP-9 activities compared with WKY-52. Examining age-dependent changes in MMP activities, we found a decrease in MMP-2 activity and increase in MMP-9 activity with increasing age in both phenotypes. Parameters of oxidative stress and antioxidant status as well as NT-proBNP levels were not significantly worsened due to aging in SHR. Our results suggest that hypertension is accompanied by varying MMP activation during aging. The results of our study may indicate that MMP-2 inhibition is therapeutically applicable during the development of hypertension, while in developed, stabilized and uncomplicated hypertension, systemic MMP-2 and MMP-9 inhibition may not be desirable.

Quercetin Exerts Age-Dependent Beneficial Effects on Blood Pressure and Vascular Function, But Is Inefficient in Preventing Myocardial Ischemia-Reperfusion Injury in Zucker Diabetic Fatty Rats.

Background: Quercetin (QCT) was shown to exert beneficial cardiovascular effects in young healthy animals. The aim of the present study was to determine cardiovascular benefits of QCT in older, 6-month and 1-year-old Zucker diabetic fatty (ZDF) rats (model of type 2 diabetes). Methods: Lean (fa/+) and obese (fa/fa) ZDF rats of both ages were treated with QCT for 6 weeks (20 mg/kg/day). Isolated hearts were exposed to ischemia-reperfusion (I/R) injury (30 min/2 h). Endothelium-dependent vascular relaxation was measured in isolated aortas. Expression of selected proteins in heart tissue was detected by Western blotting. Results: QCT reduced systolic blood pressure in both lean and obese 6-month-old rats but had no effect in 1-year-old rats. Diabetes worsened vascular relaxation in both ages. QCT improved vascular relaxation in 6-month-old but worsened in 1-year-old obese rats and had no impact in lean controls of both ages. QCT did not exert cardioprotective effects against I/R injury and even worsened post-ischemic recovery in 1-year-old hearts. QCT up-regulated expression of eNOS in younger and PKCε expression in older rats but did not activate whole PI3K/Akt pathway. Conclusions: QCT might be beneficial for vascular function in diabetes type 2; however, increasing age and/or progression of diabetes may confound its vasculoprotective effects. QCT seems to be inefficient in preventing myocardial I/R injury in type 2 diabetes and/or higher age. Impaired activation of PI3K/Akt kinase pathway might be, at least in part, responsible for failing cardioprotection in these subjects.

Promotion of whole blood rheology after vitamin C supplementation: focus on red blood cells 1.

Hemorheological properties represent significant contributors in the pathogenesis of cardiovascular diseases. As plasma vitamin C is inversely associated with blood viscosity in humans, we aimed to characterize the effect of vitamin C supplementation on hemorheology with an emphasis on erythrocyte functions. Twenty young healthy volunteers were asked to take vitamin C (1000 mg per day) for 3 weeks. We observed beneficial effect of intervention on multiple hemorheological parameters: whole blood viscosity in the range of medium to high shear rates, Casson yield stress, complex viscosity, and storage and loss moduli. As erythrocyte properties play a significant role in hemorheology, we characterized their deformability, nitric oxide production, and sodium pump activity in erythrocyte membranes. We can conclude that observed promotion in whole blood rheology may be consequence of improved erythrocyte functionality as concerns their ability to pass through narrow capillaries of the microcirculation, nitric oxide production, and sodium pump activity. Parameters reflecting oxidative stress and antioxidant status in plasma were not affected by our intervention. As improvement in hemorheology may play an important role in cardioprotection, it would be challenging to investigate the vitamin C supplementation to patients suffering from microcirculatory disturbances and worsened organ perfusion in the case of cardiovascular diseases.

Urea and creatinine levels in saliva of patients with and without periodontitis.

Despite the fact that saliva contains measurable concentrations of urea and creatinine, it is not widely used in clinical nephrology. One of the reasons is the high inter- and intra-individual variability in the salivary markers of kidney function. We hypothesized that gingival bleeding in patients with periodontitis could contribute to this variability by increasing the concentration of salivary urea or creatinine. Samples were collected from 25 patients with periodontitis and 29 healthy controls. In addition, saliva samples from five healthy volunteers were artificially contaminated with blood. The concentration of urea, but not that of creatinine, was more than twice as high in patients with periodontitis than in controls. Artificial contamination of saliva with blood did not affect the salivary concentration of creatinine. Salivary urea increased only with very high levels of contamination (≥2.5% blood in saliva), but that did not occur in patients. In conclusion, periodontitis increases the concentration of salivary urea, but this is not likely to be a result of contamination with blood. Future studies should investigate the composition of the oral microbiome, specifically regarding how it affects the concentration of salivary urea. Salivary creatinine seems to be a more robust non-invasive marker of renal functions than salivary urea.

Short-term effects of continuous positive airway pressure on oxidative stress in severe sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) is associated with oxidative stress that is involved in the pathogenesis of cardiovascular and metabolic complications. The concentrations of salivary markers of oxidative stress in patients with OSA increase considerably during the night. The dynamics is not affected by continuous positive airway pressure (CPAP) in mild to moderate OSA. The aim of this study was to analyze the short-term effects of CPAP on salivary oxidative stress markers in patients with severe OSA. METHODS: Salivary samples were collected from 24 patients with apnea-hypopnea index higher than 30 during the first (diagnostic) night, who were treated by CPAP during the second (therapeutic) night. RESULTS: The salivary markers of oxidative stress (TBARS, AGEs, and AOPP) were higher in the morning after the diagnostic night when compared to the evening concentrations (p < 0.01 for TBARS and p < 0.05 for AGEs and AOPP). Treatment by CPAP significantly decreased the morning concentrations of TBARS, AOPP (p < 0.01 for both), and AGEs (p < 0.05). Also, TBARS and AGEs positively correlated with apnea-hypopnea index (r = 0.48 and 0.49, respectively; p < 0.05). Antioxidant statuss was not affected. CONCLUSION: Severe OSA is associated with increased levels of saliva markers for lipid peroxidation, protein oxidative damage, and carbonyl damage. Even short-term CPAP partially prevents oxidative and carbonyl stress during the night and this can be monitored non-invasively using saliva.

Exosomes-Associated DNA-New Marker in Pregnancy Complications?

Despite a large number of studies, the etiology of pregnancy complications remains unknown. The involvement of cell-free DNA or fetal cell-free DNA in the pathogenesis of pregnancy complications is currently being hypothesized. Cell-free DNA occurs in different forms-free; part of neutrophil extracellular traps; or as recently discovered, carried by extracellular vesicles. Cell-free DNA is believed to activate an inflammatory pathway, which could possibly cause pregnancy complications. It could be hypothesized that DNA in its free form could be easily degraded by nucleases to prevent the inflammatory activation. However, recently, there has been a growing interest in the role of exosomes, potential protectors of cell-free DNA, in pregnancy complications. Most of the interest from recent years is directed towards the micro RNA carried by exosomes. However, exosome-associated DNA in relation to pregnancy complications has not been truly studied yet. DNA, as an important cargo of exosomes, has been so far studied mostly in cancer research. This review collects all the known information on the topic of not only exosome-associated DNA but also some information on vesicles-associated DNA and the studies regarding the role of exosomes in pregnancy complications from recent years. It also suggests possible analysis of exosome-associated DNA in pregnancy from plasma and emphasizes the importance of such analysis for future investigations of pregnancy complications. A major obstacle to the advancement in this field is the proper uniformed technique for exosomes isolation. Similarly, the sensitivity of methods analyzing a small fraction of DNA, potentially fetal DNA, carried by exosomes is variable.

Oxidative and carbonyl stress in pregnant women with obstructive sleep apnea.

PURPOSE: Pregnant women are particularly susceptible to sleep-disordered breathing. Obstructive sleep apnea (OSA) in pregnancy is associated with poor pregnancy and fetal outcomes. Oxidative stress caused by intermittent hypoxemia and reoxygenation may impact pregnancy health. We hypothesize that pregnant women with OSA have a pronounced oxidative stress profile. METHODS: A case-control study was performed to study oxidative stress markers in the serum of pregnant women with or without OSA. Patients with OSA were identified between 2003 and 2009. Contemporaneous controls were pregnant subjects without apnea, gasping, or snoring around the time of delivery. Serum markers of oxidative and carbonyl stress were measured by spectrophotometric/fluorometric methods. Multiple linear regression analysis was used with a model including age, body mass index at delivery, history of diabetes, and gestational age. RESULTS: Serum samples from 23 OSA cases and 41 controls were identified. Advanced oxidation protein products, a marker for oxidative stress, and advanced glycation end products (AGEs), a marker for carbonyl stress, were significantly lower in women with OSA than in controls (p value <0.0001). Total antioxidant capacity was higher in women with OSA in comparison to controls (p value <0.0001). The difference in AGEs remained significant even after adjusting for confounders. CONCLUSION: Contrary to our hypothesis, the results of this study suggest that pregnant women with OSA have higher antioxidant capacity and lower oxidative and carbonyl stress markers compared to controls, suggesting a possible protective effect of intermittent hypoxia. Whether OSA in pregnancy impacts oxidative stress differently than OSA in the general population remains to be confirmed.

Oxidative stress in the brain caused by acute kidney injury.

Uremic encephalopathy is a severe complication of renal failure. The underlying pathogenesis is unknown although several mechanisms have been suggested. Renal failure causes oxidative stress leading to cardiovascular complications. It has been suggested as the potential mediator of uremic encephalopathy as well, but it is largely unknown whether brain tissue itself undergoes oxidative damage in uremia. The aim of our experiment was to analyze oxidative stress markers in different brain regions in an animal model of acute kidney injury (AKI). AKI was induced by ischemia-reperfusion injury in male Wistar rats. Urine was collected in metabolic cages after 24 h. Samples of plasma and several brain regions were collected after 48 h. Markers of lipid peroxidation, protein oxidation and total antioxidant capacity were assessed. Renal failure was confirmed by high plasma creatinine, urea and urinary albumin to creatinine ratio. Our data confirmed increased systemic oxidative stress in the AKI group with plasma concentrations of markers of oxidative damage being twice as high compared to the sham-operated control group. No effect was seen in the urine. In the hippocampus, lipid and protein oxidation was higher, while antioxidant capacity was lower in the rats with AKI. Lipid oxidation markers in the frontal cortex were higher by 33%. No differences to controls were found in the cerebellum and hypothalamus. In conclusion, our results indicate that AKI leads to oxidative stress in the brain, especially in the hippocampus and in the frontal cortex. This kidney-brain crosstalk mediated by increased oxidative stress might explain some of the symptoms of uremic encephalopathy. The causes and consequences of oxidative damage observed in the brain during AKI remain to be elucidated.

Deoxyribonuclease partially ameliorates thioacetamide-induced hepatorenal injury.

Several recent studies have shown that liver injury is associated with the release of DNA from hepatocytes. This DNA stimulates innate immunity and induces sterile inflammation, exacerbating liver damage. Similar mechanisms have been described for acute renal injury. Deoxyribonuclease degrades cell-free DNA and can potentially prevent some of the induced tissue damage. This study analyzed the effects of thioacetamide-induced hepatorenal injury on plasma DNA in rats. Plasma DNA of both nuclear and mitochondrial origin was higher in thioacetamide-treated animals. Administration of deoxyribonuclease resulted in a mild, nonsignificant decrease in total plasma DNA and plasma DNA of mitochondrial origin but not of nuclear origin. This was accompanied by a decrease in bilirubin, creatinine, and blood urea nitrogen as markers of renal function. In conclusion, the study confirmed the hepatotoxic and nephrotoxic effect of thioacetamide. The associated increase in cell-free DNA seems to be involved in hepatorenal pathogenesis because treatment with deoxyribonuclease resulted in a partial prevention of hepatorenal injury. Further experiments will focus on the effects of long-term treatment with deoxyribonuclease in other clinically more relevant models. Clinical studies should test endogenous deoxyribonuclease activity as a potential risk determinant for kidney or liver failure.NEW & NOTEWORTHY Thioacetamide-induced hepatorenal injury resulted in higher plasma cell-free DNA. Deoxyribonuclease decreased average cell-free DNA of mitochondrial origin but not nuclear origin. Deoxyribonuclease partially prevented hepatorenal injury in rats.

Lactacystin-Induced Model of Hypertension in Rats: Effects of Melatonin and Captopril.

Lactacystin is a proteasome inhibitor that interferes with several factors involved in heart remodelling. The aim of this study was to investigate whether the chronic administration of lactacystin induces hypertension and heart remodelling and whether these changes can be modified by captopril or melatonin. In addition, the lactacystin-model was compared with NG-nitro-l-arginine-methyl ester (L-NAME)- and continuous light-induced hypertension. Six groups of three-month-old male Wistar rats (11 per group) were treated for six weeks as follows: control (vehicle), L-NAME (40 mg/kg/day), continuous light (24 h/day), lactacystin (5 mg/kg/day) alone, and lactacystin with captopril (100 mg/kg/day), or melatonin (10 mg/kg/day). Lactacystin treatment increased systolic blood pressure (SBP) and induced fibrosis of the left ventricle (LV), as observed in L-NAME-hypertension and continuous light-hypertension. LV weight and the cross-sectional area of the aorta were increased only in L-NAME-induced hypertension. The level of oxidative load was preserved or reduced in all three models of hypertension. Nitric oxide synthase (NOS) activity in the LV and kidney was unchanged in the lactacystin group. Nuclear factor-kappa B (NF-κB) protein expression in the LV was increased in all treated groups in the cytoplasm, however, in neither group in the nucleus. Although melatonin had no effect on SBP, only this indolamine (but not captopril) reduced the concentration of insoluble and total collagen in the LV and stimulated the NO-pathway in the lactacystin group. We conclude that chronic administration of lactacystin represents a novel model of hypertension with collagenous rebuilding of the LV, convenient for testing antihypertensive drugs or agents exerting a cardiovascular benefit beyond blood pressure reduction.

Comparison of Aerobic Preservation by Venous Systemic Oxygen Persufflation or Oxygenated Machine Perfusion of Warm-Ischemia-Damaged Porcine Kidneys.

BACKGROUND/AIM: The global shortage of donor organs for transplantation has necessitated the expansion of the organ pool through increased use of organs from less ideal donors. Venous systemic oxygen persufflation (VSOP) and oxygenated machine perfusion (OMP) have previously demonstrated beneficial results compared to cold storage (CS) in the preservation of warm-ischemia-damaged kidney grafts. The aim of this study was to compare the efficacy of VSOP and OMP for the preservation of warm-ischemia-damaged porcine kidneys using the recently introduced Ecosol preservation solution compared to CS using Ecosol or histidine-tryptophan-ketoglutarate solution (HTK). MATERIALS AND METHODS: Kidneys from German Landrace pigs (n = 5/group) were retrieved and washed out with either Ecosol or HTK after 45 min of clamping of the renal pedicle. As controls, kidneys without warm ischemia, cold stored for 24 h in HTK, were employed. Following 24 h of preservation by VSOP, OMP, CS-Ecosol, or CS-HTK, renal function and damage were assessed during 1 h using the isolated perfused porcine kidney model. RESULTS: During reperfusion, urine production was significantly higher in the VSOP and OMP groups than in the CS-HTK group; however, only VSOP could demonstrate lower urine protein concentrations and fractional excretion of sodium, which did not differ from the non-warm-ischemia-damaged control group. VSOP, CS-Ecosol, and controls showed better maintenance of the acid-base balance than CS-HTK. Reduced lipid peroxidation, as reflected in postreperfusion tissue thiobarbituric acid-reactive substance levels, was observed in the VSOP group compared to the OMP group, and the VSOP and CS-Ecosol groups had concentrations similar to the controls. The ratio of reduced to oxidized glutathione was higher in the VSOP, OMP, and CS-Ecosol groups than in the CS-HTK group and controls, with a higher ratio in the VSOP than in the OMP group. CONCLUSION: VSOP was associated with mitigation of oxidative stress in comparison to OMP and CS. Preservation of warm-ischemia-damaged porcine kidneys by VSOP was improved compared to OMP and CS, and was comparable to preservation of non-warm-ischemia-damaged cold-stored kidneys.