Kostja Renko

Learn More
The essential micronutrient selenium (Se) exerts its biological effects mainly through enzymatically active selenoproteins. Their biosynthesis depends on the 21st proteinogenic amino acid selenocysteine and thus on dietary Se supply. Hepatically derived selenoprotein P (SEPP) is the central selenoprotein in blood controlling Se transport and distribution.(More)
CONTEXT Hyperinsulinemia and insulin resistance are the major reasons for a higher prevalence of several cancer entities in type 2 diabetes mellitus and obesity. Metformin exerts a growth-inhibitory effect by reducing hyperinsulinemia and by a direct cellular action. OBJECTIVE We investigated the effect of metformin on growth of differentiated human(More)
The acute-phase response (APR) is characterized by an impaired metabolism of the essential trace element selenium (Se). Moreover, low-Se concentrations correlate to mortality risk in sepsis. Therefore, we analyzed the expression of the central Se transport and storage protein selenoprotein P (Sepp1) during an APR in mice. Serum Se and Sepp1 concentrations(More)
Selenium modifies inflammatory reactions in rodents and humans. The liver controls metabolism and transport of selenium via hepatically-derived SEPP (selenoprotein P). Intracellular SEPS (selenoprotein S) modifies endoplasmic-reticulum function and immune-cell activity. Polymorphisms in SEPS have been associated with cytokine levels and inflammatory(More)
SePP (selenoprotein P) is central for selenium transport and distribution. Targeted inactivation of the Sepp gene in mice leads to reduced selenium content in plasma, kidney, testis and brain. Accordingly, activities of selenoenzymes are reduced in Sepp(-/-) organs. Male Sepp(-/-) mice are infertile. Unlike selenium deficiency, Sepp deficiency leads to(More)
Enzymatic 5'- and 5-deiodination are key reactions for local and systemic activation and inactivation of iodothyronines and thyronamines. Expression of the three deiodinase (DIO) isoenzymes is regulated by a number of parameters, including thyroid status, genotype, micronutrient availability, and disease-related signaling. In addition, DIO are potential(More)
BACKGROUND Deiodinases (DIO1, 2, and 3) are key enzymes in thyroid hormone (TH) activation and inactivation with impact on energy metabolism, development, cell differentiation, and a number of other physiological processes. The three DIO isoenzymes thus constitute sensitive rate-limiting components within the TH axis, prone to dysregulation by endocrine(More)
Benign and malignant thyroid nodules are more prevalent in females than in males. Experimental data suggest that the proliferative effect of oestrogen rather than polymorphisms is responsible for this gender difference. This study analysed whether both differentiated thyroid cells and thyroid stem and progenitor cells are targets of oestrogen action. In(More)
Sorafenib, a multikinase inhibitor has recently been approved for the treatment of radio-iodine refractory thyroid carcinoma. However, toxic side effects may lead to dose reduction. In the present study, we analyzed whether a combined therapy with metformin may allow a dose reduction of sorafenib without loss of effectiveness at the same time. In HTh74(More)
Infectious diseases impair Se metabolism, and low Se status is associated with mortality risk in adults with critical disease. The Se status of neonates is poorly characterised, and a potential impact of connatal infection is unknown. We hypothesised that an infection negatively affects the Se status of neonates. We conducted an observational case-control(More)