D-Luciferin

D-luciferin is a cell-permeable chemiluminescent luciferase substrate with a Km of approximately 2 μM. D-luciferin could emit lights upon oxidative decarboxylation in the presence of ATP. D-luciferin provides a bioluminescent signal for in vivo and in vitro detection of cellular ATP levels. D-Luciferin chould be used to assay the expression of the luciferase gene linked to a promoter of interest. Alternatively, D-luciferin and luciferase can be used to assess ATP availability in cellular or biochemical assays. D-luciferin could be administrated intravenously or intraperitonealy. In vivo and in vitro bioluminescence imaging (BLI) is a promising technique for non-invasive tumour imaging. The repeatability coefficients of intravenously and intraperitonealy was 80.2% and 95.0%, respectively. PEmax of IP was 5.6 times higher for IV. When compared with IP, IV administration showed better repeatability and better sensitivity. It would be more beneficial to evaluate the accurate tumor burden of the small tumors rather than the larger tumors [1].

Reference:
Keyaerts M, Verschueren J, Bos T J, et al.  Dynamic bioluminescence imaging for quantitative tumour burden assessment using IV or IP administration of D-luciferin: effect on intensity, time kinetics and repeatability of photon emission[J]. European journal of nuclear medicine and molecular imaging, 2008, 35(5): 999-1007.

The Drug Excipient Cyclodextrin Interacts With d-Luciferin and Interferes With Bioluminescence Imaging.[Pubmed:27030398]

Mol Imaging. 2016 Jan 27;15. pii: 15/0/1536012115625225.

Cyclodextrins are well-characterized, barrel-shaped molecules that can solubilize organic small molecules in aqueous solution via host-guest interactions. As such, cyclodextrins are used as excipients for experimental therapeutics in vivo. We observed unanticipated modifications to bioluminescence imaging (BLI) signal intensity when 2-hydroxy-propyl-beta-cyclodextrin (HPCD) was coinjected as an excipient. We hypothesized that HPCD bindsD-Luciferin and interferes with the BLI signal. Using luciferase-expressing cell lines, we showed that HPCD lowers the BLI signal in a concentration-dependent manner. Flow cytometry revealed that HPCD resulted in reduced cellular accumulation ofD-Luciferin, and mass spectrometry revealedD-Luciferin HPCD species, confirming a direct interaction. In vivo imaging using a luciferase mouse model demonstrated that HPCD reduced luciferin-mediated BLI compared to luciferin alone. The implications of using HPCD as an excipient in BLI studies are discussed.

Hydrazide d-luciferin for in vitro selective detection and intratumoral imaging of Cu(2.).[Pubmed:27131992]

Biosens Bioelectron. 2016 Sep 15;83:200-4.

Copper is an essential micronutrient involved in fundamental life processes but using a bioluminescence (BL) probe to selectively sense Cu(2+)in vitro or image Cu(2+)in vivo is still unavailable. Herein, a latent BL probe hydrazide D-Luciferin (1) was rationally designed and successfully applied it for selective detection of Cu(2+)in vitro and imaging Cu(2+) in living cells and in tumors. Upon the catalysis of Cu(2+), 1 was converted to D-Luciferin and turned on the BL in the presence of firefly luciferase (fLuc). In vitro tests indicated that 1 could be applied for highly selective sensing Cu(2+) within the range of 0-80muM with a limit of detection (LOD) of 39.0nM. Cell and animal experiments indicated that 1 could be applied for specific BL imaging of Cu(2+) in living cells and tumors and the BL signal of 1 was more stable and longer than that of D-Luciferin. We envision that this unique probe 1 might serve as an elucidative tool for further exploration of the biological roles of Cu(2+) in physiological and pathological processes in the near future.

Intracellular Self-Assembly of Cyclic d-Luciferin Nanoparticles for Persistent Bioluminescence Imaging of Fatty Acid Amide Hydrolase.[Pubmed:27348334]

ACS Nano. 2016 Jul 26;10(7):7147-53.

Fatty acid amide hydrolase (FAAH) overexpression induces several disorder symptoms in nerve systems, and therefore long-term tracing of FAAH activity in vivo is of high importance but remains challenging. Current bioluminescence (BL) methods are limited in detecting FAAH activity within 5 h. Herein, by rational design of a latent BL probe (d-Cys-Lys-CBT)2 (1), we developed a "smart" method of intracellular reduction-controlled self-assembly and FAAH-directed disassembly of its cyclic D-Luciferin-based nanoparticles (i.e., 1-NPs) for persistent BL imaging of FAAH activity in vitro, in cells, and in vivo. Using aminoluciferin methyl amide (AMA), Lys-amino-D-Luciferin (Lys-Luc), and amino-D-Luciferin (NH2-Luc) as control BL probes, we validated that the persistent BL of 1 from luciferase-expressing cells or tumors was controlled by the activity of intracellular FAAH. With the property of long-term tracing of FAAH activity in vivo of 1, we envision that our BL precursor 1 could probably be applied for in vivo screening of FAAH inhibitors and the diagnosis of their related diseases (or disorders) in the future.

Label-Free Cell Phenotypic Identification of D-Luciferin as an Agonist for GPR35.[Pubmed:27424891]

Methods Mol Biol. 2016;1461:3-17.

D-Luciferin (also known as beetle or firefly luciferin) is one of the most widely used bioluminescent reporters for monitoring in vitro or in vivo luciferase activity. The identification of several natural phenols and thieno[3,2-b]thiophene-2-carboxylic acid derivatives as agonists for GPR35, an orphan G protein-coupled receptor, had motivated us to examine the pharmacological activity of D-Luciferin, given that it also contains phenol and carboxylic acid moieties. Here, we describe label-free cell phenotypic assays that ascertain D-Luciferin as a partial agonist for GPR35. The agonistic activity of D-Luciferin at the GPR35 shall evoke careful interpretation of biological data when D-Luciferin or its analogues are used as probes.