TY - JOUR A1 - Sharkovska, Yuliya A1 - Kalk, Philipp A1 - Lawrenz, Bettina A1 - Godes, Michael A1 - Hoffmann, Linda Sarah A1 - Wellkisch, Kathrin A1 - Geschka, Sandra A1 - Relle, Katharina A1 - Hocher, Berthold A1 - Stasch, Johannes-Peter T1 - Nitric oxide-independent stimulation of soluble guanylate cyclase reduces organ damage in experimental low- renin and high-renin models N2 - Objectives The nitric oxide-soluble guanylate cyclase (sGC)-cGMP signal transduction pathway is impaired in different cardiovascular diseases, including pulmonary hypertension, heart failure and arterial hypertension. Riociguat is a novel stimulator of soluble guanylate cyclase (sGC). However, little is known about the effects of sGC stimulators in experimental models of hypertension. We thus investigated the cardio-renal protective effects of riociguat in low- renin and high-renin rat models of hypertension. Methods The vasorelaxant effect of riociguat was tested in vitro on isolated saphenous artery rings of normal and nitrate tolerant rabbits. The cardiovascular in-vivo effects of sGC stimulation were evaluated in hypertensive renin-transgenic rats treated with the nitric oxide-synthase inhibitor N- nitro-L-arginine methyl ester (L-NAME) (high-renin model) and in rats with 5/6 nephrectomy (low-renin model). Results In both animal models, riociguat treatment improved survival and normalized blood pressure. Moreover, in the L-NAME study part, riociguat reduced cardiac target organ damage as indicated by lower plasma ANP, lower relative left ventricular weight and lower cardiac interstitial fibrosis, and reduced renal target organ damage as indicated by lower plasma creatinine and urea, less glomerulosclerosis and less renal interstitial fibrosis. In the 5/6 nephrectomy study part, riociguat reduced cardiac target organ damage as indicated by lower plasma ANP, lower relative left ventricular weight, lower myocyte diameter and lower arterial media/lumen ratio, and reduced renal target organ damage as indicated by improved creatinine clearance and less renal interstitial fibrosis. Conclusion We demonstrate for the first time that the novel sGC stimulator riociguat shows in two independent models of hypertension a potent protection against cardiac and renal target organ damage. J Hypertens 28: 1666-1675 (c) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins. Y1 - 2010 UR - http://journals.lww.com/jhypertension/pages/default.aspx U6 - https://doi.org/10.1097/Hjh.0b013e32833b558c SN - 0263-6352 ER - TY - JOUR A1 - Mutig, Kerim A1 - Kahl, Thomas A1 - Saritas, Turgay A1 - Godes, Michael A1 - Persson, Pontus A1 - Bates, James A1 - Raffi, Hajamohideen A1 - Rampoldi, Luca A1 - Uchida, Shinichi A1 - Hille, Carsten A1 - Dosche, Carsten A1 - Kumar, Satish A1 - Castaneda-Bueno, Maria A1 - Gamba, Gerardo A1 - Bachmann, Sebastian T1 - Activation of the Bumetanide-sensitive Na+, K+,2Cl(-) Cotransporter (NKCC2) Is Facilitated by Tamm-Horsfall Protein in a Chloride-sensitive Manner JF - The journal of biological chemistry N2 - Active transport of NaCl across thick ascending limb (TAL) epithelium is accomplished by Na+, K+,2Cl(-) cotransporter (NKCC2). The activity of NKCC2 is determined by vasopressin (AVP) or intracellular chloride concentration and includes its amino-terminal phosphorylation. Co-expressed Tamm-Horsfall protein (THP) has been proposed to interact with NKCC2. We hypothesized that THP modulates NKCC2 activity in TAL. THP-deficient mice (THP-/-) showed an increased abundance of intracellular NKCC2 located in subapical vesicles (+47% compared with wild type (WT) mice), whereas base-line phosphorylation of NKCC2 was significantly decreased (-49% compared with WT mice), suggesting reduced activity of the transporter in the absence of THP. Cultured TAL cells with low endogenous THP levels and low base-line phosphorylation of NKCC2 displayed sharp increases in NKCC2 phosphorylation (+38%) along with a significant change of intracellular chloride concentration upon transfection with THP. In NKCC2-expressing frog oocytes, co-injection with THP cRNA significantly enhanced the activation of NKCC2 under low chloride hypotonic stress (+112% versus +235%). Short term (30 min) stimulation of the vasopressin V2 receptor pathway by V2 receptor agonist (deamino-cis-D-Arg vasopressin) resulted in enhanced NKCC2 phosphorylation in WT mice and cultured TAL cells transfected with THP, whereas in the absence of THP, NKCC2 phosphorylation upon deamino-cis-D-Arg vasopressin was blunted in both systems. Attenuated effects of furosemide along with functional and structural adaptation of the distal convoluted tubule in THP-/- mice supported the notion that NaCl reabsorption was impaired in TAL lacking THP. In summary, these results are compatible with a permissive role for THP in the modulation of NKCC2-dependent TAL salt reabsorptive function. Y1 - 2011 U6 - https://doi.org/10.1074/jbc.M111.222968 SN - 0021-9258 VL - 286 IS - 34 SP - 30200 EP - 30210 PB - American Society for Biochemistry and Molecular Biology CY - Bethesda ER - TY - JOUR A1 - Hocher, Berthold A1 - Heimerl, Dirk A1 - Slowinski, Torsten A1 - Godes, Michael A1 - Halle, Horst A1 - Priem, Friedrich A1 - Pfab, Thiemo T1 - Birthweight and Fetal Glycosylated Hemoglobin at Birth in Newborns Carrying the GLUT1 XbaI Gene Polymorphism JF - Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion N2 - Background: Low birthweight is an independent risk factor of glucose intolerance and type 2 diabetes in later life. Genetically determined insulin resistance and subsequently impaired glucose uptake might explain both reduced fetal growth and elevated blood glucose. The glucose transporter 1 (GLUT!) plays an important role for fetal glucose uptake as well as for maternal-fetal glucose transfer, and it has been associated with insulin resistance in adults. The present study hypothesized that the common fetal GLUT1 XbaI polymorphism might reduce fetal insulin sensitivity and/or glucose supply in utero, thus affecting fetal blood glucose and fetal growth. Methods: A genetic association study was conducted at the obstetrics department of the Charite University Hospital, Berlin, Germany. 119.1 white women were included after delivery, and all newborns were genotyped for the GLUT1 XbaI polymorphism. Total glycosylated hemoglobin was quantified, serving as a surrogate of glycemia during the last weeks of pregnancy. Results: The analysis of this large population showed no significant differences in fetal glycosylated hemoglobin or birthweight for the different fetal GLUT1 XbaI genotypes. Only newborns carrying the mutated allele show the previously published inverse association between birthweight and glycosylated hemoglobin. Conclusions: The results suggest that there is no prenatal effect of the fetal GLUT1 XbaI polymorphism on fetal insulin sensitivity, intrauterine fetal glucose supply or fetal growth. However, the polymorphism seems to modulate the inverse interaction between birthweight and fetal glycemia. KW - GLUT1 XbaI gene polymorphism KW - birthweight KW - total glycosylated hemoglobin KW - insulin resistance KW - fetal programming Y1 - 2011 SN - 1433-6510 VL - 57 IS - 9-10 SP - 651 EP - 657 PB - Clin Lab Publ., Verl. Klinisches Labor CY - Heidelberg ER -