@article{SatwikoIkedaNakayamaetal.2015, author = {Satwiko, Muhammad Gahan and Ikeda, Koji and Nakayama, Kazuhiko and Yagi, Keiko and Hocher, Berthold and Hirata, Ken-Ichi and Emoto, Noriaki}, title = {Targeted activation of endothelin-1 exacerbates hypoxia-induced pulmonary hypertension}, series = {Biochemical and biophysical research communications}, volume = {465}, journal = {Biochemical and biophysical research communications}, number = {3}, publisher = {Elsevier}, address = {San Diego}, issn = {0006-291X}, doi = {10.1016/j.bbrc.2015.08.002}, pages = {356 -- 362}, year = {2015}, abstract = {Pulmonary arterial hypertension (PAH) is a fatal disease that eventually results in right heart failure and death. Current pharmacologic therapies for PAH are limited, and there are no drugs that could completely cure PAH. Enhanced activity of endothelin system has been implicated in PAH severity and endothelin receptor antagonists have been used clinically to treat PAH. However, there is limited experimental evidence on the direct role of enhanced endothelin system activity in PAL-I. Here, we investigated the correlation between endothelin-1 (ET-1) and PAH using ET-1 transgenic (ETTG) mice. Exposure to chronic hypoxia increased right ventricular pressure and pulmonary arterial wall thickness in ETTG mice compared to those in wild type mice. Of note, ETTG mice exhibited modest but significant increase in right ventricular pressure and vessel wall thickness relative to wild type mice even under normoxic conditions. To induce severe PAH, we administered SU5416, a vascular endothelial growth factor receptor inhibitor, combined with exposure to chronic hypoxia. Treatment with SU5416 modestly aggravated hypoxia-induced pulmonary hypertension, right ventricular hypertrophy, and pulmonary arterial vessel wall thickening in ETTG mice in association with increased interleukin-6 expression in blood vessels. However, there was no sign of obliterative endothelial cell proliferation and plexiform lesion formation in the lungs. These results demonstrated that enhanced endothelin system activity could be a causative factor in the development of PAH and provided rationale for the inhibition of endothelin system to treat PAH. (C) 2015 Elsevier Inc. All rights reserved.}, language = {en} } @article{TsuprykovChaykovskaKretschmeretal.2015, author = {Tsuprykov, Oleg and Chaykovska, Lyubov and Kretschmer, Axel and Stasch, Johannes-Peter and Pfab, Thiemo and Krause-Relle, Katharina and Reichetzeder, Christoph and Kalk, Philipp and Adamski, Jerzy and Hocher, Berthold}, title = {Endothelin-1 overexpression improves renal function in eNOS knockout mice}, series = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology}, volume = {37}, journal = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology}, number = {4}, publisher = {Karger}, address = {Basel}, issn = {1015-8987}, doi = {10.1159/000438516}, pages = {1474 -- 1490}, year = {2015}, abstract = {Background/Aims: To investigate the renal phenotype under conditions of an activated renal ET-1 system in the status of nitric oxide deficiency, we compared kidney function and morphology in wild-type, ET-1 transgenic (ET+/+), endothelial nitric oxide synthase knockout (eNOS-/-) and ET+/+eNOS-/- mice. Methods: We assessed blood pressure, parameters of renal morphology, plasma cystatin C, urinary protein excretion, expression of genes associated with glomerular filtration barrier and tissue remodeling, and plasma metabolites using metabolomics. Results: eNOS-/- and ET+/+eNOS-/- mice developed hypertension. Osteopontin, albumin and protein excretion were increased in eNOS-/- and restored in ET+/+eNOS-/- animals. All genetically modified mice developed renal interstitial fibrosis and glomerulosclerosis. Genes involved in tissue remodeling (serpinel, TIMP1, Collal, CCL2) were up-regulated in eNOS-/-, but not in ET+/+eNOS-/- mice. Plasma levels of free carnitine and acylcarnitines, amino acids, diacyl phosphatidylcholines, lysophosphatidylcholines and hexoses were descreased in eNOS-/- and were in the normal range in ET+/+eNOS-/- mice. Conclusion: eNOS-/- mice developed renal dysfunction, which was partially rescued by ET-1 overexpression in eNOS-/- mice. The metabolomics results suggest that ET-1 overexpression on top of eNOS knockout is associated with a functional recovery of mitochondria (rescue effect in 13-oxidation of fatty acids) and an increase in antioxidative properties (normalization of monounsaturated fatty acids levels). (C) 2015 The Author(s) Published by S. Karger AG, Basel}, language = {en} } @misc{OngvonWebskyHocher2015, author = {Ong, Albert C. M. and von Websky, Karoline and Hocher, Berthold}, title = {Endothelin and Tubulointerstitial Renal Disease}, series = {Seminars in nephrology}, volume = {35}, journal = {Seminars in nephrology}, number = {2}, publisher = {Elsevier}, address = {Philadelphia}, issn = {0270-9295}, doi = {10.1016/j.semnephrol.2015.03.004}, pages = {197 -- 207}, year = {2015}, abstract = {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. (C) 2015 Elsevier Inc. All rights reserved.}, language = {en} }