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Gene-specific placental DNA methylation patterns differ between normal pregnancies and pregnancies complicated by hypertension. However, whether global placental DNA methylation is associated with maternal blood pressure remains controversial.Using multiple linear regression models, we analysed the association between maternal mean arterial pressure (MAP) at the third trimester of pregnancy and global DNA methylation in the placenta in 922 mothers using LC-ESI-MS/MS. To better characterize the contribution of genetic or epigenetic mechanisms, we performed isolated analyses in mothers with and without a family history of hypertension.Mean placental global DNA methylation was 3.00 ± 0.46%. A significant negative correlation between placental global DNA methylation and mean arterial blood pressure (MAP) in the third trimester could be observed (P = 0.023, r = -0.075). This association remained significant after adjusting for confounders. In placenta samples from mothers with a family history of hypertension, mean maternal MAP was higher (86.1 ± 8.1 vs. 84.6 ± 7.5, P 0.01) and placental global DNA methylation was lower (2.94 ± 0.43 vs. 3.04 ± 0.47, P 0.01) compared with samples without a family history of hypertension. Furthermore, the significant independent negative correlation between global placental DNA methylation and MAP was only found in mothers without a family history of hypertension.This study showed an independent negative correlation between placental global DNA methylation and maternal MAP in mothers without a family history of hypertension.

Background Riociguat is the first of a new class of drugs, the soluble guanylate cyclase (sGC) stimulators. Riociguat has a dual mode of action: it sensitizes sGC to the body’s own NO and can also increase sGC activity in the absence of NO. The NO-sGC-pathway is impaired in many cardiovascular diseases such as heart failure, pulmonary hypertension and diabetic nephropathy (DN). DN leads to high cardiovascular morbidity and mortality. There is still a high unmet medical need. The urinary albumin excretion rate is a predictive biomarker for these clinical events. Therefore, we investigated the effect of riociguat, alone and in combination with the angiotensin II receptor antagonist (ARB) telmisartan on the progression of DN in diabetic eNOS knock out mice, a new model closely resembling human pathology. Methods Seventy-six male eNOS knockout C57BL/6J mice were divided into 4 groups after receiving intraperitoneal high-dose streptozotocin: telmisartan (1 mg/kg), riociguat (3 mg/kg), riociguat+telmisartan (3 and 1 mg/kg), and vehicle. Fourteen mice were used as non-diabetic controls. After 12 weeks, urine and blood were obtained and blood pressure measured. Glucose concentrations were highly increased and similar in all diabetic groups. Results Riociguat, alone (105.2 ± 2.5 mmHg; mean±SEM; n = 14) and in combination with telmisartan (105.0 ± 3.2 mmHg; n = 12), significantly reduced blood pressure versus diabetic controls (117.1 ± 2.2 mmHg; n = 14; p = 0.002 and p = 0.004, respectively), whereas telmisartan alone (111.2 ± 2.6 mmHg) showed a modest blood pressure lowering trend (p = 0.071; n = 14). The effects of single treatment with either riociguat (97.1 ± 15.7 µg/d; n = 13) or telmisartan (97.8 ± 26.4 µg/d; n = 14) did not significantly lower albumin excretion on its own (p = 0.067 and p = 0.101, respectively). However, the combined treatment led to significantly lower urinary albumin excretion (47.3 ± 9.6 µg/d; n = 12) compared to diabetic controls (170.8 ± 34.2 µg/d; n = 13; p = 0.004), and reached levels similar to non-diabetic controls (31.4 ± 10.1 µg/d, n = 12). Conclusion Riociguat significantly reduced urinary albumin excretion in diabetic eNOS knock out mice that were refractory to treatment with ARB’s alone. Patients with diabetic nephropathy refractory to treatment with ARB’s have the worst prognosis among all patients with diabetic nephropathy. Our data indicate that additional stimulation of sGC on top of standard treatment with ARB`s may offer a new therapeutic approach for patients with diabetic nephropathy resistant to ARB treatment., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 855

Background and purpose Results regarding protective effects of dipeptidyl peptidase 4 (DPP4) inhibitors in renal ischaemia-reperfusion injury (IRI) are conflicting. Here we have compared structurally unrelated DPP4 inhibitors in a model of renal IRI. Experimental approach IRI was induced in uninephrectomized male rats by renal artery clamping for 30 min. The sham group was uninephrectomized but not subjected to IRI. DPP4 inhibitors or vehicle were given p.o. once daily on three consecutive days prior to IRI: linagliptin (1.5 mg·kg-1 ·day-1 ), vildagliptin (8 mg·kg-1 ·day-1 ) and sitagliptin (30 mg·kg-1 ·day-1 ). An additional group received sitagliptin until study end (before IRI: 30 mg·kg-1 ·day-1 ; after IRI: 15 mg·kg-1 ·day-1 ). Key results Plasma-active glucagon-like peptide type 1 (GLP-1) increased threefold to fourfold in all DPP4 inhibitor groups 24 h after IRI. Plasma cystatin C, a marker of GFR, peaked 48 h after IRI. Compared with the placebo group, DPP4 inhibition did not reduce increased plasma cystatin C levels. DPP4 inhibitors ameliorated histopathologically assessed tubular damage with varying degrees of drug-specific efficacies. Renal osteopontin expression was uniformly reduced by all DPP4 inhibitors. IRI-related increased renal cytokine expression was not decreased by DPP4 inhibition. Renal DPP4 activity at study end was significantly inhibited in the linagliptin group, but only numerically reduced in the prolonged/dose-adjusted sitagliptin group. Active GLP-1 plasma levels at study end were increased only in the prolonged/dose-adjusted sitagliptin treatment group. Conclusions and implications In rats with renal IRI, DPP4 inhibition did not alter plasma cystatin C, a marker of glomerular function, but may protect against tubular damage.

Background/Aims: Gestational diabetes (GDM) might be associated with alterations in the metabolomic profile of affected mothers and their offspring. Until now, there is a paucity of studies that investigated both, the maternal and the fetal serum metabolome in the setting of GDM. Mounting evidence suggests that the fetus is not just passively affected by gestational disease but might play an active role in it. Metabolomic studies performed in maternal blood and fetal cord blood could help to better discern distinct fetal from maternal disease interactions. Methods: At the time of birth, serum samples from mothers and newborns (cord blood samples) were collected and screened for 163 metabolites utilizing tandem mass spectrometry. The cohort consisted of 412 mother/child pairs, including 31 cases of maternal GDM. Results: An initial non-adjusted analysis showed that eight metabolites in the maternal blood and 54 metabolites in the cord blood were associated with GDM. After Benjamini-Hochberg (BH) procedure and adjustment for confounding factors for GDM, fetal phosphatidylcholine acyl-alkyl C 32:1 and proline still showed an independent association with GDM. Conclusions: This study found metabolites in cord blood which were associated with GDM, even after adjustment for established risk factors of GDM. To the best of our knowledge, this is the first study demonstrating an independent association between fetal serum metabolites and maternal GDM. Our findings might suggest a potential effect of the fetal metabolome on maternal GDM. (c) 2018 The Author(s) Published by S. Karger AG, Basel, Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 637

Observational studies from all over the world continue to find high prevalence rates of vitamin D insufficiency and deficiency in many populations, including pregnant women. Beyond its classical function as a regulator of calcium and phosphate metabolism, vitamin D elicits numerous effects in the human body. Current evidence highlights a vital role of vitamin D in mammalian gestation. During pregnancy, adaptations in maternal vitamin D metabolism lead to a physiologic increase of vitamin D levels, mainly because of an increased renal production, although other potential sources like the placenta are being discussed. A sufficient supply of mother and child with calcium and vitamin D during pregnancy ensures a healthy bone development of the fetus, whereas lack of either of these nutrients can lead to the development of rickets in the child. Moreover, vitamin D insufficiency during pregnancy has consistently been associated with adverse maternal and neonatal pregnancy outcomes. In multitudinous studies, low maternal vitamin D status was associated with a higher risk for pre-eclampsia, gestational diabetes mellitus and other gestational diseases. Likewise, several negative consequences for the fetus have been reported, including fetal growth restriction, increased risk of preterm birth and a changed susceptibility for later-life diseases. However, study results are diverging and causality has not been proven so far. Meta-analyses on the relationship between maternal vitamin D status and pregnancy outcomes revealed a wide heterogeneity of studied populations and the applied methodology in vitamin D assessment. Until today, clinical guidelines for supplementation cannot be based on high-quality evidence and it is not clear if the required intake for pregnant women differs from non-pregnant women. Long-term safety data of vitamin D supplementation in pregnant women has not been established and overdosing of vitamin D might have unfavorable effects, especially in mothers and newborns with mutations of genes involved in vitamin D metabolism. Reliable data from large observational and interventional randomized control trials are urgently needed as a basis for any detailed and safe recommendations for supplementation in the general population and, most importantly, in pregnant women. This is of utmost importance, as ensuring a sufficient vitamin D-supply of mother and child implies a great potential for the prevention of birth complications and development of diseases.

Dipeptidyl peptidase type 4 (DPP-4) inhibitors were reported to have beneficial effects in experimental models of chronic kidney disease. The underlying mechanisms are not completely understood. However, these effects could be mediated via the glucagon-like peptide-1 (GLP-1)/GLP-1 receptor (GLP1R) pathway. Here we investigated the renal effects of the DPP-4 inhibitor linagliptin in Glp1r-/- knock out and wild-type mice with 5/6 nephrectomy (5/6Nx). Mice were allocated to groups: sham + wild type + placebo; 5/6Nx+ wild type + placebo; 5/6Nx+ wild type + linagliptin; sham + knock out+ placebo; 5/6Nx + knock out+ placebo; 5/6Nx + knock out+ linagliptin. 5/6Nx caused the development of renal interstitial fibrosis, significantly increased plasma cystatin C and creatinine levels and suppressed renal gelatinase/collagenase, matrix metalloproteinase-1 and -13 activities; effects counteracted by linagliptin treatment in wildtype and Glp1r-/- mice. Two hundred ninety-eight proteomics signals were differentially regulated in kidneys among the groups, with 150 signals specific to linagliptin treatment as shown by mass spectrometry. Treatment significantly upregulated three peptides derived from collagen alpha-1(I), thymosin beta 4 and heterogeneous nuclear ribonucleoprotein Al (HNRNPA1) and significantly downregulated one peptide derived from Y box binding protein-1 (YB-1). The proteomics results were further confirmed using western blot and immunofluorescence microscopy. Also, 5/6Nx led to significant up-regulation of renal transforming growth factor-beta 1 and pSMAD3 expression in wild type mice and linagliptin significantly counteracted this up-regulation in wild type and GIplr-/- mice. Thus, the renoprotective effects of linagliptin cannot solely be attributed to the GLP-1/GLP1R pathway, highlighting the importance of other signaling pathways (collagen I homeostasis, HNRNPA1,YB-1,thymosin beta 4 and TGF-beta 1) influenced by DPP-4 inhibition.

All components of the endothelin (ET) system are present in renal tubular cells. In this review, we summarize current knowledge about ET and the most common tubular diseases: acute kidney injury (AKI) and polycystic kidney disease. AKI originally was called acute tubular necrosis, pointing to the most prominent morphologic findings. Similarly, cysts in polycystic kidney disease, and especially in autosomal-dominant polycystic kidney disease, are of tubular origin. Preclinical studies have indicated that the ET system and particularly ETA receptors are involved in the pathogenesis of ischemia-reperfusion injury, although these findings have not been translated to clinical studies. The ET system also has been implicated in radiocontrast-dye-induced AKI, however, ET-receptor blockade in a large human study was not successful. The ET system is activated in sepsis models of AKI; the effectiveness of ET blocking agents in preclinical studies is variable depending on the model and the ET-receptor antagonist used. Numerous studies have shown that the ET system plays an important role in the complex pathophysiology associated with cyst formation and disease progression in polycystic kidney disease. However, results from selective targeting of ET-receptor subtypes in animal models of polycystic kidney disease have proved disappointing and do not support clinical trials. These studies have shown that a critical balance between ETA and ETB receptor action is necessary to maintain structure and function in the cystic kidney. In summary, ETs have been implicated in the pathogenesis of several renal tubulointerstitial diseases, however, experimental animal findings have not yet led to use of ET blockers in human beings.

Purpose of review Incretin-based therapy with glucagon-like peptide-1 receptor (GLP-1R) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors is considered a promising therapeutic option for type 2 diabetes mellitus. Cumulative evidence, mainly from preclinical animal studies, reveals that incretin-based therapies also may elicit beneficial effects on kidney function. This review gives an overview of the physiology, pathophysiology, and pharmacology of the renal incretin system. Recent findings Activation of GLP-1R in the kidney leads to diuretic and natriuretic effects, possibly through direct actions on renal tubular cells and sodium transporters. Moreover, there is evidence that incretin-based therapy reduces albuminuria, glomerulosclerosis, oxidative stress, and fibrosis in the kidney, partially through GLP-1R-independent pathways. Molecular mechanisms by which incretins exert their renal effects are understood incompletely, thus further studies are needed. Summary The GLP-1R and DPP-4 are expressed in the kidney in various species. The kidney plays an important role in the excretion of incretin metabolites and most GLP-1R agonists and DPP-4 inhibitors, thus special attention is required when applying incretin-based therapy in renal impairment. Preclinical observations suggest direct renoprotective effects of incretin-based therapies in the setting of hypertension and other disorders of sodium retention, as well as in diabetic and nondiabetic nephropathy. Clinical studies are needed in order to confirm translational relevance from preclinical findings for treatment options of renal diseases.

Dipeptidyl peptidase (DPP)-4 inhibitors delay chronic kidney disease (CKD) progression in experimental diabetic nephropathy in a glucose-independent manner. Here we compared the effects of the DPP-4 inhibitor linagliptin versus telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. Animals were allocated to 1 of 4 groups: sham operated plus placebo; 5/6 nephrectomy plus placebo; 5/6 nephrectomy plus linagliptin; and 5/6 nephrectomy plus telmisartan. Interstitial fibrosis was significantly decreased by 48% with linagliptin but a non-significant 24% with telmisartan versus placebo. The urine albumin-to-creatinine ratio was significantly decreased by 66% with linagliptin and 92% with telmisartan versus placebo. Blood pressure was significantly lowered by telmisartan, but it was not affected by linagliptin. As shown by mass spectrometry, the number of altered peptide signals for linagliptin in plasma was 552 and 320 in the kidney. For telmisartan, there were 108 peptide changes in plasma and 363 in the kidney versus placebo. Linagliptin up-regulated peptides derived from collagen type I, apolipoprotein C1, and heterogeneous nuclear ribonucleoproteins A2/B1, a potential downstream target of atrial natriuretic peptide, whereas telmisartan up-regulated angiotensin II. A second study was conducted to confirm these findings in 5/6 nephrectomy wild-type and genetically deficient DPP-4 rats treated with linagliptin or placebo. Linagliptin therapy in wild-type rats was as effective as DPP-4 genetic deficiency in terms of albuminuria reduction. Thus, linagliptin showed comparable efficacy to telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. However, the underlying pathways seem to be different. Copyright (C) 2016, International Society of Nephrology. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Background: The need for an improved treatment for diabetic nephropathy is greatest in patients who do not adequately respond to angiotensin II receptor blockers (ARBs). This study investigated the effect of the novel dipeptidyl peptidase-4 inhibitor linagliptin alone and in combination with the ARB telmisartan on the progression of diabetic nephropathy in diabetic endothelial nitric oxide synthase (eNOS) knockout mice. Methods: Sixty male eNOS knockout C57BL/6J mice were divided into four groups after receiving intraperitoneal high-dose streptozotocin: telmisartan (1 mg/kg), linagliptin (3 mg/kg), linagliptin + telmisartan (3 mg/kg + 1 mg/kg) and vehicle. Fourteen mice were used as non-diabetic controls. Results: After 12 weeks, urine and blood were obtained and blood pressure measured. Glucose concentrations were increased and similar in all diabetic groups. Telmisartan alone reduced systolic blood pressure by 5.9 mmHg versus diabetic controls (111.2 +/- 2.3 mmHg vs 117.1 +/- 2.2 mmHg; mean +/- SEM; P = 0.071). Combined treatment significantly reduced albuminuria compared with diabetic controls (71.7 +/- 15.3 mu g/24 h vs 170.8 +/- 34.2 mu g/24 h; P = 0.017), whereas the effects of single treatment with either telmisartan (97.8 +/- 26.4 mu g/24 h) or linagliptin (120.8 +/- 37.7 mu g/24 h) were not statistically significant. DPP-4 inhibition, alone and in combination, led to significantly lower plasma osteopontin levels compared with telmisartan alone. Histological analysis revealed reduced glomerulosclerosis after Linagliptin alone and in combination with telmisartan in comparison to non treated diabetic animals (p < 0.01 and p < 0.05). Kidney malonaldehyde immune-reactivity, a marker of oxidative stress, was significantly lower in animals treated with linagliptin. Conclusions: DPP-4 inhibition on top of ARB treatment significantly reduced urinary albumin excretion and oxidative stress in diabetic eNOS knockout mice. Linagliptin on top of an angiotensin II receptor blocker may offer a new therapeutic approach for patients with diabetic nephropathy.

Activation of the endothelin (ET) system promotes vasoconstriction, inflammation, and fibrosis in various tissues, including the lung. Therefore, ET-1 transgenic mice overexpressing ET-1 develop pulmonary fibrosis in a slow, age-dependent manner. In vivo, NO is the most important counterregulatory mediator of the ET system and decreases ET-1 promoter activity. The aim of our study was to elucidate the impact on pulmonary inflammation and fibrosis of the interaction between NO and the ET system in young ET-1 transgenic mice before the onset of pulmonary fibrosis. Male ET-1 transgenic mice and wild-type littermates at the age of 8 weeks were randomly allocated to the following 6 groups: WT (n = 11), wild-type animals without treatment; WT + l-NAME (n = 14), wild-type animals receiving l-NAME, an inhibitor of NO synthase; WT + l-NAME + LU (n = 13), wild-type animals receiving l-NAME and LU 302872, a dual ETA/ETB-receptor antagonist; ET1tg (n = 10), ET-1 transgenic mice; ET1tg + l-NAME (n = 13); and ET1tg + l-NAME + LU (n = 13). After 6 weeks, animals were euthanized, and hearts and lungs were harvested for histology and immunohistochemistry. No differences in pulmonary inflammation, as indicated by macrophage infiltration, or in interstitial fibrosis were observed between WT and ET1tg mice at baseline; however, inflammation and interstitial fibrosis were significantly enhanced in ET1tg mice, but not in WT groups, after l-NAME treatment. The combined ETA/ETB-receptor antagonist LU 302872 abolished inflammation and interstitial fibrosis in l-NAME-treated ET1tg mice. Perivascular fibrosis and media/lumen ratio of pulmonary bronchi and arteries did not differ between all study groups. In our study l-NAME induced pulmonary fibrosis and inflammation only in young ET1tg mice. Additional treatment with LU 302872 abolished these effects. We thus conclude that an imbalance between an activated ET system and a suppressed NO system contributes to pulmonary inflammation and fibrosis.

Background The matrix metalloproteinases (MMP) MMP-2 and MMP-9 are physiological regulators of vascular remodelling. Their dysregulation could contribute to vascular calcification. We examined the role of the MMP-2 and MMP-9 in uraemic vascular calcification in vivo and in vitro. Methods The impact of pharmacological MMP inhibition on the development of media calcifications was explored in an aggressive animal model of uraemic calcification. In addition, the selective effects of addition and inhibition, respectively, of MMP-2 and MMP-9 on calcium-/phosphate-induced calcifications were studied in a murine cell line of vascular smooth muscle cells (VSMCs). Results High-dose calcitriol treatment of uraemic rats given a high phosphate diet induced massive calcifications, apoptosis and increased gene expressions of MMP-2, MMP-9 and of osteogenic transcription factors and proteins in aortic VSMC. The MMP inhibitor doxycycline prevented the VSMC transdifferentiation to osteoblastic cells, suppressed transcription of mediators of matrix remodelling and almost completely blocked aortic calcifications while further increasing apoptosis. Similarly, specific inhibitors of either MMP-2 or -9, or of both gelatinases (Ro28-2653) and a selective knockdown of MMP-2/-9 mRNA expression blocked calcification of murine VSMC induced by calcification medium (CM). In contrast to MMP inhibition, recombinant MMP-2 or MMP-9 enhanced CM-induced calcifications and the secretion of gelatinases. Conclusions These data indicate that both gelatinases provide essential signals for phenotypic VSMC conversion, matrix remodelling and the initiation of vascular calcification. Their inhibition seems a promising strategy in the prevention of vascular calcifications.

Background/Aims: In diabetic nephropathy (DN), the current angiotensin-II-blocking pharmacotherapy is frequently failing. For diabetic cardiomyopathy (DC), there is no specific remedy available. Relaxin-2 (Rlx) - an anti-fibrotic, anti-inflammatory, and vasoprotecting peptide - is a candidate drug for both. Methods: Low-dose (32 µg/kg/day) and high-dose (320 µg/kg/day) Rlx were tested against vehicle (n = 20 each) and non-diabetic controls (n = 14) for 12 weeks in a model of type-1 diabetes induced in endothelial nitric oxide synthase knock-out (eNOS-KO) mice by intraperitoneal injection of streptozotocin. Results: Diabetic animals showed normal plasma creatinine, markedly increased albuminuria and urinary malonyldialdehyde, elevated relative kidney weight, glomerulosclerosis, and increased glomerular size, but no relevant interstitial fibrosis. Neither dose of Rlx affected these changes although the drug was active and targeted plasma levels were achieved. Of note, we found no activation of the renal TGF-β pathway in this model. In the hearts of diabetic animals, no fibrotic alterations indicative of DC could be determined which precluded testing of the initial hypothesis. Conclusions: We investigated a model showing early DN without overt tubulo-interstitial fibrosis and activation of the TGF-β-Smad-2/3 pathway. In this model, Rlx proved ineffective; however, the same may not apply to other models and types of diabetes.

Background/Aims: Excess maternal salt intake during pregnancy may alter fetal development. However, our knowledge on how an increased salt intake during pregnancy influences fetal eye development is limited. In this study, we investigated the effects of high-salt treatment on the developing eyes in chick embryos, especially focusing on the development of the retina and the lens. Methods: 5.5-day chick embryos were exposed to 280mosm/l (n=17), or 300mosm/l (n=16) NaCl. The treated embryos were then incubated for 96 hours before they were fixed with 4% paraformaldehyde for H&E staining, whole-mount embryo immunostaining and TUNEL staining. BrdU and PH3 incorporation experiments were performed on the chick embryos after high-salt treatment. RT-PCR analyses were conducted from chick retina tissues. Results: We demonstrated that high-salt treatment altered the size of eyes in chick embryos, induced malformation of the eyes and impaired the development of the lens and the retina. We found an impaired expression of Paired box 6 (PAX6) and neuronal cells in the developing retina as revealed by neurofilament immunofluorescent staining. There was a reduction in the number of BrdU-positive cells and PH3-positive cells in the retina, indicating an impaired cell proliferation with high-salt treatment. High-salt treatment also resulted in an increased number of TUNEL-positive cells in the retina, indicating a higher amount of cell death. RT-PCR data displayed that the expression of the pro-apoptotic molecule nerve growth factor (NGF) in chick retina was increased and CyclinD1 was reduced with high-salt treatment. The size of the lens was reduced and Pax6 expression in the lens was significantly inhibited. High salt-treatment was detrimental to the migration of neural crest cells. Conclusion: Taken together, our study demonstrated that high-salt exposure of 5.5-day chick embryos led to an impairment of retina and lens development, possibly through interfering with Pax6 expression.

Background: Western blot is the gold standard method to determine individual protein expression levels. However, western blot is technically difficult to perform in large sample sizes because it is a time consuming and labor intensive process. Dot blot is often used instead when dealing with large sample sizes, but the main disadvantage of the existing dot blot techniques, is the absence of signal normalization to a housekeeping protein. Methods: In this study we established a one dot two development signals (ODTDS) dot blot method employing two different signal development systems. The first signal from the protein of interest was detected by horseradish peroxidase (HRP). The second signal, detecting the housekeeping protein, was obtained by using alkaline phosphatase (AP). Results: Inter-assay results variations within ODTDS dot blot and western blot and intra-assay variations between both methods were low (1.04 - 5.71%) as assessed by coefficient of variation. Conclusions: ODTDS dot blot technique can be used instead of western blot when dealing with large sample sizes without a reduction in results accuracy.

Aims Symptoms of cancer cachexia (CC) include fatigue, shortness of breath, and impaired exercise capacity, which are also hallmark symptoms of heart failure (HF). Herein, we evaluate the effects of drugs commonly used to treat HF (bisoprolol, imidapril, spironolactone) on development of cardiac wasting, HF, and death in the rat hepatoma CC model (AH-130). Methods and results Tumour-bearing rats showed a progressive loss of body weight and left-ventricular (LV) mass that was associated with a progressive deterioration in cardiac function. Strikingly, bisoprolol and spironolactone significantly reduced wasting of LV mass, attenuated cardiac dysfunction, and improved survival. In contrast, imidapril had no beneficial effect. Several key anabolic and catabolic pathways were dysregulated in the cachectic hearts and, in addition, we found enhanced fibrosis that was corrected by treatment with spironolactone. Finally, we found cardiac wasting and fibrotic remodelling in patients who died as a result of CC. In living cancer patients, with and without cachexia, serum levels of brain natriuretic peptide and aldosterone were elevated. Conclusion Systemic effects of tumours lead not only to CC but also to cardiac wasting, associated with LV-dysfunction, fibrotic remodelling, and increased mortality. These adverse effects of the tumour on the heart and on survival can be mitigated by treatment with either the β-blocker bisoprolol or the aldosterone antagonist spironolactone. We suggest that clinical trials employing these agents be considered to attempt to limit this devastating complication of cancer.

OBJECTIVE: To investigate the effects of linagliptin alone and in combination with the angiotensin II receptor blocker (ARB), telmisartan on blood pressure (BP), kidney function, heart morphology and oxidative stress in rats with renovascular hypertension. METHODS: Fifty-seven male Wistar rats underwent unilateral surgical stenosis of the renal artery [2-kidney-1-clip (2k1c) method]. Animals were randomly divided into four treatment groups (n = 14-18 per group) receiving: telmisartan (10 mg/kg per day in drinking water), linagliptin (89 ppm in chow), combination (linagliptin 89 ppm + telmisartan 10 mg/kg per day) or placebo. An additional group of 12 rats underwent sham surgery. BP was measured one week after surgery. Hypertensive animals entered a 16-week dosing period. BP was measured 2, 4, 8, 12 and 16 weeks after the initiation of treatment. Blood and urine were tested for assessment of kidney function and oxidative stress 6, 10, 14 and 18 weeks after surgery. Blood and urine sampling and organ harvesting were finally performed. RESULTS: Renal stenosis caused an increase in mean ± SD systolic BP as compared with the sham group (157.7 ± 29.3 vs. 106.2 ± 20.5 mmHg, respectively; P

The prevalence of diabetes mellitus and its complications, such as diabetic nephropathy (DN), is rising worldwide and prevention and treatment are therefore becoming increasingly important. Therapy of DN is particularly important for patients who do not adequately respond to angiotensin receptor blocker (ARB) treatment. Novel approaches include the stimulation of soluble guanylate cyclase (sGC) as it is reported to have beneficial effects on cardiac and renal damage. We aimed to investigate the effects of the sGC stimulator riociguat and ARB telmisartan on kidney function and structure in a hypertensive model of diabetic nephropathy. Seventy-six diabetic male eNOS knockout C57BL/6J mice were randomly divided after having received streptozotocin: telmisartan (1 mg/kg/d), riociguat (3 mg/kg/d), riociguat+telmisartan (3+1 mg/kg/d), and vehicle. Fourteen mice were used as non-diabetic controls. Treatment duration was 11 weeks. Glucose concentrations were increased and similar in all diabetic groups. Telmisartan insignificantly reduced blood pressure by 5.9 mmHg compared with diabetic controls (111.2 +/- 2.3 mmHg vs. 117.1 +/- 2.2 mmHg; p = 0.071). Treatment with riociguat both alone and in combination with telmisartan led to a significant reduction of blood pressure towards diabetic vehicle (105.2 +/- 2.5 mmHg and 105.0 +/- 3.2 mmHg, respectively, vs. 117.1 +/- 2.2 mmHg). Combined treatment also significantly decreased albuminuria compared with diabetic controls (47.3 +/- 9.6 mu g/24 h vs. 170.8 +/- 34.2 mu g/24 h; p = 0.002) reaching levels similar to those of non-diabetic controls (34.4 +/- 10.6 mu g/24 h), whereas the reduction by single treatment with either telmisartan (97.8 +/- 26.4 mu g/24 h) or riociguat (97.1 +/- 15.7 mu g/24 h) was not statistically significant. The combination treatment led to a significant (p < 0.01) decrease of tissue immunoreactivity of malondialdehyde, as consequence of reduced oxidative stress. In conclusion, stimulation of sGC significantly reduced urinary albumin excretion in diabetic eNOS knockout mice treated already with ARB. Thus, this new drug class on top of standard ARBs administration may offer a new therapeutic approach for patients resistant to ARB treatment.

SUMMARY Background: As the prevalence of diabetes rises, its complications such as diabetic nephropathy affect an increaseing number of patients. Consequently, the need for biomarkers in rodent models which reflect the stage and course of diabetic nephropathy is high. This article focuses on Heart-type fatty acid binding protein (H-FABP), osteopontin (OPN), nephrin, and Neutrophil gelatinase-associated lipocalin (NGAL) in urine, and kidney injury molecule (KIM)-1, clusterin, and tissue inhibitior of metalloproteinases (TIMP) 1 in plasma in uni-nephrectomized rats with streptocotozin-induced type 1 diabetes mellitus, a common animal model to explore renal impairment in the setting of diabetes mellitus. Methods: 23 male Wistar rats were uni-nephrectomized and subsequently divided into two study groups. The diabetic group received streptozotocin (STZ) via tail-vein injection, the non-diabetic group received citrate buffer without STZ. Subsequently, blood glucose, body weight, and blood pressure were checked regularly. After 18 weeks, animals were placed in metabolic cages, blood and urine obtained and subsequently organs were harvested after sacrifice. Results: Blood glucose levels were highly increased in diabetic animals throughout the experiment, whereas systolic blood pressure did not differ between the study groups. At study end, classical biomarkers such as urinary albumin and protein and plasma cystatin c were only slightly but not significantly different between groups indicating a very early disease state. In contrast, urinary excretion of H-FABP, OPN, nephrin, and NGAL were highly increased in diabetic animals with a highly significant p-value (p

Hypertensive heart disease is a major contributor to cardiovascular mortality. Endothelin is a potent vasoconstrictive and profibrotic mediator produced by the endothelin-converting enzyme (ECE), whereas natriuretic peptides, degraded by the neutral endopeptidase (NEP), have diuretic, vasodilatory, and antifibrotic properties. Thus, combined ECE/NEP inhibition may halt hypertensive cardiac remodeling. This study examined effects of SLV338, a novel ECE/NEP inhibitor, on cardiac protection in experimental renovascular hypertension (2-kidney, 1-clip [2K1C]). Male rats were allocated to 5 groups: sham-operated rats, untreated animals with 2K1C, 2K1C animals treated with oral SLV338 (30 and 100 mg/kg per day), and 2K1C animals treated with oral losartan (20 mg/kg per day). Treatment duration was 12 weeks. Blood pressure was assessed every 4 weeks. At study end, hearts were taken for histology/computer-aided histomorphometry/immunohistochemistry. Pharmacological properties of SLV338 are described. SLV338 is a dual ECE/NEP inhibitor, as demonstrated both in vitro and in vivo. In the 2K1C study, losartan lowered blood pressure by

Liver cirrhosis is often complicated by an impaired renal excretion of water and sodium. Diuretics tend to further deteriorate renal function. It is unknown whether chronic selective adenosine A(1) receptor blockade, via inhibition of the hepatorenal reflex and the tubuloglomerular feedback, might exert diuretic and natriuretic effects without a reduction of the glomerular filtration rate. In healthy animals intravenous treatment with the novel A(1) receptor antagonist SLV329 resulted in a strong dose-dependent diuretic (up to 3.4-fold) and natriuretic (up to 13.5-fold) effect without affecting creatinine clearance. Male Wistar rats with thioacetamide-induced liver cirrhosis received SLV329, vehicle or furosemide for 12 weeks. The creatinine clearance of cirrhotic animals decreased significantly (-36.5%, p < 0.05), especially in those receiving furosemide (-41.9%, p < 0.01). SLV329 was able to prevent this decline of creatinine clearance. Mortality was significantly lower in cirrhotic animals treated with SLV329 in comparison to animals treated with furosemide (17% vs. 54%, p < 0.05). SLV329 did not relevantly influence the degree of liver fibrosis, kidney histology or expression of hepatic or renal adenosine receptors. In conclusion, chronic treatment with SLV329 prevented the decrease of creatinine clearance in a rat model of liver cirrhosis. Further studies will have to establish whether adenosine A(1) receptor antagonists are clinically beneficial at different stages of liver cirrhosis.

Objectives In an experimental heart failure model, we tested the hypothesis that furosemide causes excess mortality. Background Post-hoc analysis of large clinical heart failure trails revealed that furosemide treatment might be associated with worsening of morbidity and even mortality in heart failure patients. Methods and results Myocardial infarction was induced in 7±1week old male Wistar rats by ligation of the left coronary artery. In study 1, animals were randomly assigned to treatment with furosemide (10mg/kg/d via drinking water, n =33) or placebo ( n =33) starting 18days after surgery. In study 2, animals received furosemide from day 18 and were then randomized to ongoing treatment with either furosemide only ( n =38) or furosemide plus ACE-inhibitor Ramipril (1mg/kg/d, n =38) starting on day 42. In study 1 survival rate in the furosemide group was lower than in the placebo group (hazard ratio {HR} 3.39, 95% confidence interval {CI} 1.14 to 10.09, p =0.028). The furosemide group had a lower body weight (−6%, p =0.028) at the end of the study and a higher sclerosis index of the glomeruli (+9%, p =0.026) than the placebo group. Wet lung weight, infarct size, and cardiac function were similar between the groups. In study 2, the furosemide group had a higher mortality rate than the furosemide+ramipril group (HR 4.55, 95% CI 2.0 to 10.0, p =0.0003). Conclusion In our rat model of heart failure furosemide, provided at a standard dose, was associated with increased mortality. This increased mortality could be prevented by additional administration of an ACE-inhibitor.

BACKGROUND Peritoneal fibrosis is a serious complication of peritoneal dialysis (PD); however, the mechanisms are poorly understood. The endothelin system exhibits potent pro-fibrotic properties and is known to be stimulated in peritoneal fibrosis. Thus, our study aimed at elucidating the impact of the endothelin B (ETB) receptor on peritoneal membrane thickening by means of an ETB-deficient rat model (ETB(-)(/)(-)) in experimental PD. METHODS Wild-type (WT) and ETB(-/-) rats were randomly allocated to four groups (each group n = 10): (i) WT Sham, (ii) WT PD, (iii) ETB(-/-) Sham and (iv) ETB(-/-) PD. All animals underwent surgical implantation of a port for intraperitoneal administration and 1 week of habituation to the procedure by administration of 2 ml of saline once daily. Afterwards, all animals were switched to 12 weeks of 15 ml of saline (Sham groups) or commercially available PD fluid containing 3.86% glucose (PD groups) administered twice daily. Afterwards, animals were sacrificed, and samples from visceral as well as parietal peritoneum were obtained. The samples were stained with Sirius-Red, and at 10 different sites per sample, peritoneal membrane thickness was measured using computer-aided histomorphometry devices. RESULTS Mean peritoneal membrane thickness was increased by PD in both WT and ETB(-/-) rats versus respective Sham controls (WT Sham: 22.3 +/- 0.7 microm/ETB Sham: 22.3 +/- 0.9 microm versus WT PD: 26.5 +/- 1.5 microm/ETB PD: 28.7 +/- 1.2 microm; P < 0.05, respectively). However, no difference in peritoneal membrane thickness was detected between WT PD and ETB(-/-) PD groups. CONCLUSION Our study demonstrates that PD increases peritoneal membrane thickness in a rat model, but deficiency of the ETB receptor has no detectable impact on this process.

Genetically modified animal models are an important part of medical research. By inducing conditions similar to human diseases in animals, pathophysiologic hypotheses and therapeutic strategies can be tested and evaluated.

Activation of the endothelin (ET) system promotes vasoconstriction, inflammation, and fibrosis in various tissues, including the lung. Therefore, ET-1 transgenic mice overexpressing ET-1 develop pulmonary fibrosis in a slow, age-dependent manner. In vivo, NO is the most important counterregulatory mediator of the ET system and decreases ET-1 promoter activity. The aim of our study was to elucidate the impact on pulmonary inflammation and fibrosis of the interaction between NO and the ET system in young ET-1 transgenic mice before the onset of pulmonary fibrosis. Male ET-1 transgenic mice and wild-type littermates at the age of 8 weeks were randomly allocated to the following 6 groups: WT (n = 11), wild-type animals without treatment; WT + L-NAME (n = 14), wild-type animals receiving L-NAME, an inhibitor of NO synthase; WT + L-NAME + LU (n = 13), wild-type animals receiving L-NAME and LU 302872, a dual ETA/ETB-receptor antagonist; ET1tg (n = 10), ET-1 transgenic mice; ET1tg + L-NAME (n = 13); and ET1tg + L-NAME + LU (n = 13). After 6 weeks, animals were euthanized, and hearts and lungs were harvested for histology and immunohistochemistry. No differences in pulmonary inflammation, as indicated by macrophage infiltration, or in interstitial fibrosis were observed between WT and ET1tg mice at baseline; however, inflammation and interstitial fibrosis were significantly enhanced in ET1tg mice, but not in WT groups, after L-NAME treatment. The combined ETA/ETB-receptor antagonist LU 302872 abolished inflammation and interstitial fibrosis in L-NAME-treated ET1tg mice. Perivascular fibrosis and media/lumen ratio of pulmonary bronchi and arteries did not differ between all study groups. In our study L-NAME induced pulmonary fibrosis and inflammation only in young ET1tg mice. Additional treatment with LU 302872 abolished these effects. We thus conclude that an imbalance between an activated ET system and a suppressed NO system contributes to pulmonary inflammation and fibrosis.

Type 2 diabetes mellitus (T2DM) is a highly prevalent, progressive disease that often is poorly controlled. The combination of an incretin-based therapy and insulin is a promising approach to optimize the management of glycemic control without hypoglycemia and weight gain. Linagliptin, a recently approved oral dipeptidyl peptidase-4 inhibitor, has a unique pharmacological profile. The convenient, once-daily dosing does not need adjustment in patients with hepatic and/or renal impairment. In clinical studies linagliptin shows an important reduction of blood glucose with an overall safety profile similar to that of placebo. So far, the combination of linagliptin and insulin has been tested in three major clinical studies in different populations. It has been shown that linagliptin is an effective and safe add-on therapy to insulin in patients with T2DM. The efficacy and safety of this combination was also shown in vulnerable, elderly T2DM patients and in patients with T2DM and renal impairment. Favorable effects regarding the counteraction of hypoglycemia make linagliptin especially interesting as an add-on therapy to insulin. This review aims to present the existing clinical studies on the efficacy and safety of linagliptin as add-on therapy to insulin in patients with T2DM in the context of current literature. Additionally, the possible advantages of linagliptin as an add-on therapy to insulin in relation to cardiovascular safety, patient-centered therapy and the prevention of hypoglycemia, are discussed.

Background: Uremic cardiomyopathy contributes substantially to mortality in chronic kidney disease (CKD) patients. Glucagon-like peptide-1 (GLP-1) may improve cardiac function, but is mainly degraded by dipeptidyl peptidase-4 (DPP-4). Methodology/Principal Findings: In a rat model of chronic renal failure, 5/6-nephrectomized [5/6N] rats were treated orally with DPP-4 inhibitors (linagliptin, sitagliptin, alogliptin) or placebo once daily for 4 days from 8 weeks after surgery, to identify the most appropriate treatment for cardiac dysfunction associated with CKD. Linagliptin showed no significant change in blood level AUC(0-infinity) in 5/6N rats, but sitagliptin and alogliptin had significantly higher AUC(0-infinity) values; 41% and 28% (p=0.0001 and p=0.0324), respectively. No correlation of markers of renal tubular and glomerular function with AUC was observed for linagliptin, which required no dose adjustment in uremic rats. Linagliptin 7 mu mol/kg caused a 2-fold increase in GLP-1 (AUC 201.0 ng/l*h) in 5/6N rats compared with sham-treated rats (AUC 108.6 ng/l*h) (p=0.01). The mRNA levels of heart tissue fibrosis markers were all significantly increased in 5/6N vs control rats and reduced/normalized by linagliptin. Conclusions/Significance: DPP-4 inhibition increases plasma GLP-1 levels, particularly in uremia, and reduces expression of cardiac mRNA levels of matrix proteins and B-type natriuretic peptides (BNP). Linagliptin may offer a unique approach for treating uremic cardiomyopathy in CKD patients, with no need for dose-adjustment.