TY - JOUR A1 - Tsuprykov, Oleg A1 - Chen, Xin A1 - Hocher, Carl-Friedrich A1 - Skoblo, Roman A1 - Yin, Lianghong A1 - Hocher, Berthold T1 - Why should we measure free 25(OH) vitamin D? JF - The Journal of Steroid Biochemistry and Molecular Biology N2 - Vitamin D, either in its D-2 or D-3 form, is essential for normal human development during intrauterine life, kidney function and bone health. Vitamin D deficiency has also been linked to cancer development and some auto immune diseases. Given this huge impact of vitamin Don human health, it is important for daily clinical practice and clinical research to have reliable tools to judge on the vitamin D status. The major circulating form of vitamin D is 25-hydroxyvitamin D (25(OH)D), although it is not the most active metabolite, the concentrations of total 25-hydroxyvitamin D in the serum are currently routinely used in clinical practice to assess vitamin D status. In the circulation, vitamin D - like other steroid hormones - is bound tightly to a special carrier - vitamin D-binding protein (DBP). Smaller amounts are bound to blood proteins - albumin and lipoproteins. Only very tiny amounts of the total vitamin D are free and potentially biologically active. Currently used vitamin D assays do not distinguish between the three forms of vitamin D - DBP-bound vitamin D, albumin-bound vitamin D and free, biologically active vitamin D. Diseases or conditions that affect the synthesis of DBP or albumin thus have a huge impact on the amount of circulating total vitamin D. DBP and albumin are synthesized in the liver, hence all patients with an impairment of liver function have alterations in their total vitamin D blood concentrations, while free vitamin D levels remain mostly constant. Sex steroids, in particular estrogens, stimulate the synthesis of DBP. This explains why total vitamin D concentrations are higher during pregnancy as compared to nonpregnant women, while the concentrations of free vitamin D remain similar in both groups of women. The vitamin D-DBP as well as vitamin D-albumin complexes are filtered through the glomeruli and re-uptaken by megalin in the proximal tubule. Therefore, all acute and chronic kidney diseases that are characterized by a tubular damage, are associated with a loss of vitamin D-DBP complexes in the urine. Finally, the gene encoding DBP protein is highly polymorphic in different human racial groups. In the current review, we will discuss how liver function, estrogens, kidney function and the genetic background might influence total circulating vitamin D levels and will discuss what vitamin D metabolite is more appropriate to measure under these conditions: free vitamin D or total vitamin D. KW - 1,25(OH)(2) vitamin D KW - Bioavailable vitamin D KW - Calculated free 25(OH) vitamin D KW - Free 25(OH) vitamin D KW - Free vitamin D KW - Directly measured free vitamin D KW - Genetic polymorphism KW - Total 25(OH) vitamin D KW - Vitamin D-binding protein Y1 - 2107 U6 - https://doi.org/10.1016/j.jsbmb.2017.11.014 SN - 0960-0760 VL - 180 SP - 87 EP - 104 PB - Elsevier CY - Oxford ER - TY - GEN A1 - Tammen, Harald A1 - Koemhoff, Martin A1 - Mark, Michael A1 - Hocher, Berthold A1 - Delic, Denis A1 - Hess, Rüdiger A1 - von Eynatten, Maximilian A1 - Klein, Thomas T1 - Linagliptin treatment is associated with improved cobalamin (vitamin B-12) storage in mice and potentially in humans T2 - Diabetologia : journal of the European Association for the Study of Diabetes (EASD) Y1 - 2018 SN - 0012-186X SN - 1432-0428 VL - 61 SP - S252 EP - S253 PB - Springer CY - New York ER - TY - JOUR A1 - Li, Jian A1 - Lu, Yong-Ping A1 - Tsuprykov, Oleg A1 - Hasan, Ahmed Abdallah Abdalrahman Mohamed A1 - Reichetzeder, Christoph A1 - Tian, Mei A1 - Zhang, Xiao Li A1 - Zhang, Qin A1 - Sun, Guo-Ying A1 - Guo, Jingli A1 - Gaballa, Mohamed Mahmoud Salem Ahmed A1 - Peng, Xiao-Ning A1 - Lin, Ge A1 - Hocher, Berthold T1 - Folate treatment of pregnant rat dams abolishes metabolic effects in female offspring induced by a paternal pre-conception unhealthy diet JF - Diabetologia : journal of the European Association for the Study of Diabetes (EASD) N2 - Aims/hypothesis Paternal high-fat diet prior to mating programmes impaired glucose tolerance in female offspring. We examined whether the metabolic consequences in offspring could be abolished by folate treatment of either the male rats before mating or the corresponding female rats during pregnancy. Methods Male F0 rats were fed either control diet or high-fat, high-sucrose and high-salt diet (HFSSD), with or without folate, before mating. Male rats were mated with control-diet-fed dams. After mating, the F0 dams were fed control diet with or without folate during pregnancy. KW - Glucose tolerance KW - High-fat-sucrose-salt diet KW - Maternal folate treatment KW - Paternal programming Y1 - 2018 U6 - https://doi.org/10.1007/s00125-018-4635-x SN - 0012-186X SN - 1432-0428 VL - 61 IS - 8 SP - 1862 EP - 1876 PB - Springer CY - New York ER - TY - JOUR A1 - Luo, Ting A1 - Chen, Xiaoyi A1 - Zeng, Shufei A1 - Guan, Baozhang A1 - Hu, Bo A1 - Meng, Yu A1 - Liu, Fanna A1 - Wong, Taksui A1 - Lu, Yongpin A1 - Yun, Chen A1 - Hocher, Berthold A1 - Yin, Lianghong T1 - Bioinformatic identification of key genes and analysis of prognostic values in clear cell renal cell carcinoma JF - Oncology Letters N2 - The present study aimed to identify new key genes as potential biomarkers for the diagnosis, prognosis or targeted therapy of clear cell renal cell carcinoma (ccRCC). Three expression profiles (GSE36895, GSE46699 and GSE71963) were collected from Gene Expression Omnibus. GEO2R was used to identify differentially expressed genes (DEGs) in ccRCC tissues and normal samples. The Database for Annotation, Visualization and Integrated Discovery was utilized for functional and pathway enrichment analysis. STRING v10.5 and Molecular Complex Detection were used for protein-protein interaction (PPI) network construction and module analysis, respectively. Regulation network analyses were performed with the WebGestal tool. UALCAN web-portal was used for expression validation and survival analysis of hub genes in ccRCC patients from The Cancer Genome Atlas (TCGA). A total of 65 up- and 164 downregulated genes were identified as DEGs. DEGs were enriched with functional terms and pathways compactly related to ccRCC pathogenesis. Seventeen hub genes and one significant module were filtered out and selected from the PPI network. The differential expression of hub genes was verified in TCGA patients. Kaplan-Meier plot showed that high mRNA expression of enolase 2 (ENO2) was associated with short overall survival in ccRCC patients (P=0.023). High mRNA expression of cyclin D1 (CCND1) (P<0.001), fms related tyrosine kinase 1 (FLT1) (P=0.004), plasminogen (PLG) (P<0.001) and von Willebrand factor (VWF) (P=0.008) appeared to serve as favorable factors in survival. These findings indicate that the DEGs may be key genes in ccRCC pathogenesis and five genes, including ENO2, CCND1, PLT1, PLG and VWF, may serve as potential prognostic biomarkers in ccRCC. KW - clear cell renal cell carcinoma KW - bioinformatics KW - differentially expressed genes KW - biomarkers KW - Kaplan-Meier plot Y1 - 2018 U6 - https://doi.org/10.3892/ol.2018.8842 SN - 1792-1074 SN - 1792-1082 VL - 16 IS - 2 SP - 1747 EP - 1757 PB - Spandidos publ LTD CY - Athens ER - TY - GEN A1 - Hocher, Berthold A1 - Yin, Lianghong T1 - Why Current PTH Assays Mislead Clinical Decision Making in Patients with Secondary Hyperparathyroidism T2 - Nephron N2 - Preclinical studies in cell culture systems as well as in whole animal chronic kidney disease (CKD) models showed that parathyroid hormone (PTH), oxidized at the 2 methionine residues (positions 8 and 18), caused a loss of function. This was so far not considered in the development of PTH assays used in current clinical practice. Patients with advanced CKD are subject to oxidative stress, and plasma proteins (including PTH) are targets for oxidants. In patients with CKD, a considerable but variable fraction (about 70 to 90%) of measured PTH appears to be oxidized. Oxidized PTH (oxPTH) does not interact with the PTH receptor resulting in loss of biological activity. Currently used intact PTH (iPTH) assays detect both oxidized and non-oxPTH (n-oxPTH). Clinical studies demonstrated that bioactive, n-oxPTH, but not iPTH nor oxPTH, is associated with mortality in CKD patients. KW - Serum intact-parathyroid hormone level KW - Dialysis patients KW - Mortality Y1 - 2017 U6 - https://doi.org/10.1159/000455289 SN - 1660-8151 SN - 2235-3186 SN - 0028-2766 VL - 136 IS - 2 SP - 137 EP - 142 PB - Karger CY - Basel ER - TY - CHAP A1 - Hocher, Berthold A1 - Armbruster, Franz Paul A1 - Scholze, Alexandra A1 - Marckmann, Peter A1 - Reichetzeder, Christoph A1 - Roth, Heinz Jürgen A1 - Tepel, Martin T1 - Non-oxidized, biological active parathyroid hormone determines motality in hemodialsysis patients T2 - Nephrology, dialysis, transplantation Y1 - 2013 SN - 0931-0509 VL - 28 SP - 33 EP - 33 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Vignon-Zellweger, Nicolas A1 - Rahnenführer, Jan A1 - Theuring, Franz A1 - Hocher, Berthold T1 - Analysis of cardiac and renal endothelin receptors by in situ hybridization in mice JF - Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion N2 - Background: Endothelin-1 (ET-1) is a multifunctional peptide, which is implicated in the renal and cardiac physicology as well as in many pathologies of these systems. ET-1's actions take place after the activation of two receptors: ETA and ETB. The expression of these receptors may be modulated during the pathologic process. The analysis of the distribution and level of expression of the receptors in animal models is therefore crucial. Methods: We developed a protocol for non-radioactive in situ hybridization for the mRNA of the two endothelin receptors on paraffin-embedded tissue using digoxigenin-labeled RNA probes. Results: In heart and kidney, the staining was reliable and specific. In a mouse model for endothelin/nitric oxide imbalance, cardiac ETB expression was reduced. The distribution of the receptors was in accordance with the actual knowledge. Differences in cell specific expression are discussed. Conclusions: We developed a protocol for the in situ hybridization of the endothelin receptors in mice. Given that the endothelin system is implicated in the development of many diseases, we believe that this protocol may be useful for a number of future preclinical studies. KW - Endothelin-1 KW - endothelin receptors KW - in situ hybridization KW - mouse Y1 - 2012 U6 - https://doi.org/10.7754/Clin.Lab.2012.120216 SN - 1433-6510 VL - 58 IS - 9-10 SP - 939 EP - 949 PB - Clin Lab Publ., Verl. Klinisches Labor CY - Heidelberg ER - TY - JOUR A1 - von Websky, Karoline A1 - Reichetzeder, Christoph A1 - Hocher, Berthold T1 - Physiology and pathophysiology of incretins in the kidney JF - Current opinion in nephrology and hypertension : reviews of all advances, evaluations of key references, comprehensive listing of papers N2 - Purpose of reviewIncretin-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 findingsActivation 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.SummaryThe 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. KW - DDP-4 inhibition KW - diabetes KW - diabetic nephropathy KW - GLP-1 receptor KW - hypertension KW - incretins KW - kidney KW - renal impairment Y1 - 2014 U6 - https://doi.org/10.1097/01.mnh.0000437542.77175.a0 SN - 1062-4821 SN - 1473-6543 VL - 23 IS - 1 SP - 54 EP - 60 PB - Lippincott Williams & Wilkins CY - Philadelphia ER -