Journal: Amino Acids

Abbreviation

Amino acids (Wien, Print)

Publisher

Springer

Journal Volumes

ISSN

0939-4451
1438-2199

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Publications 1 - 10 of 12
  • Why do Proteins use Selenocysteine Instead of Cysteine?
    Item type: Journal Article
    Nauser, Thomas; Steinmann, Daniel; Koppenol, Willem H. (2012)
    Amino Acids
  • Metallocomplex precursors for the synthesis of (18)f-fluorinated aromatic amino acids labelled in alpha fluoromethyl moiety
    Item type: Other Conference Item
    Geolchanyan, A.V.; Saghyan, A.S.; Mkrtchyan, A.F.; et al. (2016)
    Amino Acids
  • Why do proteins use selenocysteine instead of cysteine?
    Item type: Other Conference Item
    Nauser, Thomas; Steinmann, Daniel; Koppenol, Willem H. (2009)
    Amino Acids
  • Synthesis and preliminary biological evaluation of O-2((2-[18F]fluoroethyl)methylamino)ethyltyrosine ([18F]FEMAET) as a potential cationic amino acid PET tracer for tumor imaging
    Item type: Journal Article
    Chiotellis, Aristeidis; Müller, Adrienne; Weyermann, Karin; et al. (2014)
    Amino Acids
    Amino acid transport is an attractive target for oncologic imaging. Despite a high demand of cancer cells for cationic amino acids, their potential as PET probes remains unexplored. Arginine, in particular, is involved in a number of biosynthetic pathways that significantly influence carcinogenesis and tumor biology. Cationic amino acids are transported by several cationic transport systems including, ATB0,+ (SLC6A14), which is upregulated in certain human cancers including cervical, colorectal and estrogen receptor-positive breast cancer. In this work, we report the synthesis and preliminary biological evaluation of a new cationic analog of the clinically used PET tumor imaging agent O-(2-[18F]fluroethyl)-l-tyrosine ([18F]FET), namely O-2((2-[18F]fluoroethyl)methylamino)ethyltyrosine ([18F]FEMAET). Reference compound and precursor were prepared by multi-step approaches. Radiosynthesis was achieved by no-carrier-added nucleophilic [18F]fluorination in 16–20 % decay-corrected yields with radiochemical purity >99 %. The new tracer showed good stability in vitro and in vivo. Cell uptake assays demonstrated that FEMAET and [18F]FEMAET accumulate in prostate cancer (PC-3) and small cell lung cancer cells (NCI-H69), with an energy-dependent mechanism. Small animal PET imaging with NCI-H69 xenograft-bearing mice revealed good tumor visualization comparable to [18F]FET and low brain uptake, indicating negligible transport across the blood–brain barrier. In conclusion, the non-natural cationic amino acid PET probe [18F]FEMAET accumulates in cancer cells in vitro and in vivo with possible involvement of ATB0,+.
  • Towards a better understanding of nuclear processes based on proteomics
    Item type: Review Article
    Tweedie-Cullen, Ry Yves; Mansuy, Isabelle (2010)
    Amino Acids
  • A short review on creatine-creatine kinase system in relation to cancer and some experimental results on creatine as adjuvant in cancer therapy
    Item type: Journal Article
    Patra, Subrata; Ghosh, Alok; Roy, Soumya Sinha; et al. (2012)
    Amino Acids
  • The creatine kinase system and pleiotropic effects of creatine
    Item type: Journal Article
    Wallimann, Theo; Tokarska-Schlattner, Malgorzata; Schlattner, Uwe (2011)
    Amino Acids
  • The effects of creatine supplementation on striatal neural progenitor cells depend on developmental stage
    Item type: Journal Article
    Andres, Robert H.; Ducray, Angelique D.; Andereggen, Lukas; et al. (2016)
    Amino Acids
  • Creatine: a miserable life without it
    Item type: Journal Article
    Wallimann, Theo W.; Harris, Roger C.H. (2016)
    Amino Acids
  • Creatine homeostasis and the kidney: comparison between kidney transplant recipients and healthy controls
    Item type: Journal Article
    Post, Adrian; Groothof, Dion; Kremer, Daan; et al. (2024)
    Amino Acids
    Creatine is a natural nitrogenous organic acid that is integral to energy metabolism and crucial for proper cell functioning. The kidneys are involved in the first step of creatine production. With kidney transplantation being the gold-standard treatment for end-stage kidney disease, kidney transplant recipients (KTR) may be at risk of impaired creatine synthesis. We aimed to compare creatine homeostasis between KTR and controls. Plasma and urine concentrations of arginine, glycine, guanidinoacetate, creatine and creatinine were measured in 553 KTR and 168 healthy controls. Creatine intake was assessed using food frequency questionnaires. Iothalamate-measured GFR data were available in subsets of 157 KTR and 167 controls. KTR and controls had comparable body weight, height and creatine intake (all P > 0.05). However, the total creatine pool was 14% lower in KTR as compared to controls (651 ± 178 vs. 753 ± 239 mmol, P < 0.001). The endogenous creatine synthesis rate was 22% lower in KTR as compared to controls (7.8 ± 3.0 vs. 10.0 ± 4.1 mmol per day, P < 0.001). Despite lower GFR, the plasma guanidinoacetate and creatine concentrations were 21% and 41% lower in KTR as compared to controls (both P < 0.001). Urinary excretion of guanidinoacetate and creatine were 66% and 59% lower in KTR as compared to controls (both P < 0.001). In KTR, but not in controls, a higher measured GFR was associated with a higher endogenous creatine synthesis rate (std. beta: 0.21, 95% CI: 0.08; 0.33; P = 0.002), as well as a higher total creatine pool (std. beta: 0.22, 95% CI: 0.11; 0.33; P < 0.001). These associations were fully mediated (93% and 95%; P < 0.001) by urinary guanidinoacetate excretion which is consistent with production of the creatine precursor guanidinoacetate as rate-limiting factor. Our findings highlight that KTR have a disturbed creatine homeostasis as compared to controls. Given the direct relationship of measured GFR with endogenous creatine synthesis rate and the total creatine pool, creatine supplementation might be beneficial in KTR with low kidney function. Trial registration ID: NCT02811835. Trial registration URL: https://clinicaltrials.gov/ct2/show/NCT02811835.
Publications 1 - 10 of 12