TY  - JOUR
A1  - Glosse, Philipp
A1  - Feger, Martina
A1  - Mutig, Kerim
A1  - Chen, Hong
A1  - Hirche, Frank
A1  - Hasan, Ahmed Abdallah Abdalrahman Mohamed
A1  - Gaballa, Mohamed Mahmoud Salem Ahmed
A1  - Hocher, Berthold
A1  - Lang, Florian
A1  - Föller, Michael
T1  - AMP-activated kinase is a regulator of fibroblast growth factor 23 production
JF  - Kidney international : official journal of the International Society of Nephrology
N2  - Fibroblast growth factor 23 (FGF23) is a proteohormone regulating renal phosphate transport and vitamin D metabolism as well as inducing left heart hypertrophy. FGF23-deficient mice suffer from severe tissue calcification, accelerated aging and a myriad of aging-associated diseases. Bone cells produce FGF23 upon store-operated calcium ion entry (SOCE) through the calcium selective ion channel Orai1. AMP-activated kinase (AMPK) is a powerful energy sensor helping cells survive states of energy deficiency, and AMPK down-regulates Orai1. Here we investigated the role of AMPK in FGF23 production. Fgf23 gene transcription was analyzed by qRT-PCR and SOCE by fluorescence optics in UMR106 osteoblast-like cells while the serum FGF23 concentration and phosphate metabolism were assessed in AMPKa1-knockout and wild-type mice. The AMPK activator, 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) down-regulated, whereas the AMPK inhibitor, dorsomorphin dihydrochloride (compound C) and AMPK gene silencing induced Fgf23 transcription. AICAR decreased membrane abundance of Orai1 and SOCE. SOCE inhibitors lowered Fgf23 gene expression induced by AMPK inhibition. AMPKa1-knockout mice had a higher serum FGF23 concentration compared to wild-type mice. Thus, AMPK participates in the regulation of FGF23 production in vitro and in vivo. The inhibitory effect of AMPK on FGF23 production is at least in part mediated by Orai1-involving SOCE.
KW  - calcium
KW  - FGF23
KW  - Klotho
KW  - Orai1
KW  - phosphate
KW  - parathyroid hormone
Y1  - 2018
U6  - https://doi.org/10.1016/j.kint.2018.03.006
SN  - 0085-2538
SN  - 1523-1755
VL  - 94
IS  - 3
SP  - 491
EP  - 501
PB  - Elsevier
CY  - New York
ER  - 
TY  - JOUR
A1  - Feger, Martina
A1  - Fajol, Abul
A1  - Lebedeva, Aleksandra
A1  - Meissner, Adrian
A1  - Michael, Diana
A1  - Völkl, Jakob
A1  - Alesutan, Ioana
A1  - Schleicher, Erwin
A1  - Reichetzeder, Christoph
A1  - Hocher, Berthold
A1  - Qadri, Syed M.
A1  - Lang, Florian
T1  - Effect of Carbon Monoxide Donor CORM-2 on Vitamin D-3 Metabolism
JF  - Kidney & blood pressure research : official organ of the Gesellschaft für Nephrologie
N2  - Background/Aims: Carbon monoxide (CO) interferes with cytochrome-dependent cellular functions and acts as gaseous transmitter. CO is released from CO-releasing molecules (CORM) including tricarbonyl-dichlororuthenium (II) dimer (CORM-2), molecules considered for the treatment of several disorders including vascular dysfunction, inflammation, tissue ischemia and organ rejection. Cytochrome P450-sensitive function include formation of 1,25-dihydroxyvitamin D-3 (1,25(OH)(2)D-3) by renal 25-hydroxyvitamin D-3 1-alpha-hydroxylase (Cyp27b1). The enzyme is regulated by PTH, FGF23 and klotho. 1,25(OH)(2)D-3 regulates Ca2+ and phosphate transport as well as klotho expression. The present study explored, whether CORM-2 influences 1,25(OH)(2)D-3 formation and klotho expression. Methods: Mice were treated with intravenous CORM-2 (20 mg/kg body weight). Plasma 1,25(OH)(2)D-3 and FGF23 concentrations were determined by ELISA, phosphate, calcium and creatinine concentrations by colorimetric methods, transcript levels by quantitative RT-PCR and protein expression by western blotting. Fgf23 mRNA transcript levels were further determined in rat osteosarcoma UMR106 cells without or with prior treatment for 24 hours with 20 mu M CORM-2. Results: CORM-2 injection within 24 hours significantly increased FGF23 plasma levels and decreased 1,25(OH)(2)D-3 plasma levels, renal Cyp27b1 gene expression as well as renal klotho protein abundance and transcript levels. Moreover, treatment of UMR106 cells with CORM-2 significantly increased Fgf23 transcript levels. Conclusion: CO-releasing molecule CORM-2 enhances FGF23 expression and release and decreases klotho expression and 1,25(OH)(2)D-3 synthesis.
KW  - CORM-2
KW  - 1,25-Dihydroxyvitamin D-3
KW  - Klotho
KW  - FGF23
KW  - Phosphate
KW  - Calcium
Y1  - 2013
U6  - https://doi.org/10.1159/000355730
SN  - 1420-4096
SN  - 1423-0143
VL  - 37
IS  - 4-5
SP  - 496
EP  - 505
PB  - Karger
CY  - Basel
ER  -