Aberrant Cyclization Affords a C-6 Modified Cyclic Adenosine 5′-Diphosphoribose Analogue with Biological Activity in Jurkat T Cells

*S Supporting Information ABSTRACT: Two nicotinamide adenine dinucleotide (NAD +) analogues modified at the 6 position of the purine ring were synthesized, and their substrate properties toward Aplysia californica ADP-ribosyl cyclase were investigated. 6-N-Methyl NAD + (6-N-methyl nicotinamide adenosine 5′-dinucleotide 10) hydrolyzes to give the linear 6-N-methyl ADPR (adenosine 5′-diphosphoribose, 11), whereas 6-thio NHD + (nicotinamide 6-mercaptopurine 5′-dinucleotide, 17) generates a cyclic dinucleotide. Surprisingly, NMR correlation spectra confirm this compound to be the N1 cyclic product 6-thio N1-cIDPR (6-thio cyclic inosine 5′-diphosphoribose, 3), although the corresponding 6-oxo analogue is well-known to cyclize at N7. In Jurkat T cells, unlike the parent cyclic inosine 5′-diphosphoribose N1-cIDPR 2, 6-thio N1-cIDPR antagonizes both cADPR- and N1cIDPR-induced Ca 2+ release but possesses weak agonist activity at higher concentration. 3 is thus identified as the first C-6 modified cADPR (cyclic adenosine 5′-diphosphoribose) analogue antagonist; it represents the first example of a fluorescent N1cyclized cADPR analogue and is a new pharmacological tool for intervention in the cADPR pathway of cellular signaling

2ʹ-Deoxyadenosine 5ʹ-diphosphoribose is an endogenous TRPM2 superagonist

Transient receptor potential melastatin 2 (TRPM2) is a ligand-gated Ca2+-permeable nonselective cation channel. Whereas physiological stimuli, such as chemotactic agents, evoke controlled Ca2+ signals via TRPM2, pathophysiological stimuli such as reactive oxygen species and genotoxic stress result in prolonged TRPM2-mediated Ca2+ entry and, consequently, apoptosis. To date, adenosine 5'-diphosphoribose (ADPR) has been assumed to be the main agonist for TRPM2. Here we show that 2'-deoxy-ADPR was a significantly better TRPM2 agonist, inducing 10.4-fold higher whole-cell currents at saturation. Mechanistically, this increased activity was caused by a decreased rate of inactivation and higher average open probability. Using high-performance liquid chromatography (HPLC) and mass spectrometry, we detected endogenous 2'-deoxy-ADPR in Jurkat T lymphocytes. Consistently, cytosolic nicotinamide mononucleotide adenylyltransferase 2 (NMNAT-2) and nicotinamide adenine dinucleotide (NAD)-glycohydrolase CD38 sequentially catalyzed the synthesis of 2'-deoxy-ADPR from nicotinamide mononucleotide (NMN) and 2'-deoxy-ATP in vitro. Thus, 2'-deoxy-ADPR is an endogenous TRPM2 superagonist that may act as a cell signaling molecule

Does the Comprehensive ICF Core Set for rheumatoid arthritis capture occupational therapy practice? A content-validity study

Background: The ICF Core Sets for rheumatoid arthritis (RA) constitute an application of the International Classification of Functioning, Disability and Health (ICF). Purpose: To explore whether the ICF Core Sets for RA include the areas of functioning and environmental factors that are typically treated by occupational therapists in their clinical everyday practice with clients with RA. Methods: In a three-round survey occupational therapists were asked about their intervention goals when treating clients with RA. The identified goals were grouped into goal classes that were then linked to the ICF. Results. 41 occupational therapists in nine countries named 533 intervention goals that were grouped into 48 goal classes and then linked to ICF categories of all ICF components. The goal classes self-confidence, relaxation and psycho-social well-being are not represented in the Comprehensive ICF Core Set for RA. Conclusion: The validity of the ICF Core Set for RA from the perspective of occupational therapists was largely confirmed

Validation of the comprehensive ICF core set for osteoarthritis: the perspective of physical therapists

Background and purpose: Osteoarthritis is a common chronic disease associated with functional impairments and activity limitations, as well as participation restrictions. The Comprehensive International Classification of Functioning, Disability and Health (ICF) Core Set for Osteoarthritis is an application of the ICF and represents the typical spectrum of problems in functioning of patients with osteoarthritis.Objective: To validate the Comprehensive ICF Core Set for Osteoarthritis from the perspective of physical therapists.Methods: Physical therapists experienced in the treatment of patients with osteoarthritis were asked about patients' problems, resources and aspects of the environmental factors treated by physical therapists in patients with osteoarthritis in a three-round, electronic-mail survey using the Delphi technique. Responses were linked to the ICF.Results: Seventy-two experts from 22 countries named 744 meaningful concepts that covered all ICF components. One hundred and fifty-two ICF categories were linked to these answers, 32 concepts were linked to the not-yet-developed personal factors component, and 14 issues were not covered by a single ICF category. Twelve ICF categories were not represented in the Comprehensive ICF Core Set for Osteoarthritis, although at least 75% of the participants rated them as important.Discussion and conclusion: The content validity of the ICF was widely supported by the physical therapists. However, several issues were raised that were not covered and need to be investigated further

Content validation of the International Classification of Functioning, Disability and Health (ICF) Core Set for stroke: the perspective of occupational therapists

Background: The "ICF Core Set for stroke" is an application of the International Classification of Functioning, Disability and Health (ICF) and represents the typical spectrum of problems in the functioning of patients with stroke.Purpose: The objective of this study was to validate this ICF Core Set from the perspective of occupational therapists.Methods: In a three-round electronic mail survey using the Delphi technique, occupational therapists experienced in stroke treatment were asked about patients'problems, patients' resources, and aspects of environment they take care of. Two health professionals linked responses to the ICF.Findings: Sixty-nine occupational therapists in 21 countries named 1,747 concepts that occupational therapists treat in patients with stroke. These concepts were linked to 347 different ICF categories. Twenty-three concepts were linked to the ICF component Personal Factors.Conclusion: The content validity of the "ICF Core Set for stroke" was largely supported by occupational therapists

Aberrant Cyclization Affords a C-6 Modified Cyclic Adenosine 5′-Diphosphoribose Analogue with Biological Activity in Jurkat T Cells

Two nicotinamide adenine dinucleotide (NAD⁺) analogues modified at the 6 position of the purine ring were synthesized, and their substrate properties toward <i>Aplysia californica</i> ADP-ribosyl cyclase were investigated. 6-<i>N</i>-Methyl NAD⁺ (6-<i>N</i>-methyl nicotinamide adenosine 5′-dinucleotide <b>10</b>) hydrolyzes to give the linear 6-<i>N</i>-methyl ADPR (adenosine 5′-diphosphoribose, <b>11</b>), whereas 6-thio NHD⁺ (nicotinamide 6-mercaptopurine 5′-dinucleotide, <b>17</b>) generates a cyclic dinucleotide. Surprisingly, NMR correlation spectra confirm this compound to be the <i>N</i>1 cyclic product 6-thio <i>N</i>1-cIDPR (6-thio cyclic inosine 5′-diphosphoribose, <b>3</b>), although the corresponding 6-oxo analogue is well-known to cyclize at <i>N</i>7. In Jurkat T cells, unlike the parent cyclic inosine 5′-diphosphoribose <i>N</i>1-cIDPR <b>2</b>, 6-thio <i>N</i>1-cIDPR antagonizes both cADPR- and <i>N</i>1-cIDPR-induced Ca²⁺ release but possesses weak agonist activity at higher concentration. <b>3</b> is thus identified as the first C-6 modified cADPR (cyclic adenosine 5′-diphosphoribose) analogue antagonist; it represents the first example of a fluorescent <i>N</i>1-cyclized cADPR analogue and is a new pharmacological tool for intervention in the cADPR pathway of cellular signaling

8-Bromo-cyclic inosine diphosphoribose: towards a selective cyclic ADP-ribose agonist

cADPR (cyclic ADP-ribose) is a universal Ca(2+) mobilizing second messenger. In T-cells cADPR is involved in sustained Ca(2+) release and also in Ca(2+) entry. Potential mechanisms for the latter include either capacitative Ca(2+) entry, secondary to store depletion by cADPR, or direct activation of the non-selective cation channel TRPM2 (transient receptor potential cation channel, subfamily melastatin, member 2). Here we characterize the molecular target of the newly-described membrane-permeant cADPR agonist 8-Br-N(1)-cIDPR (8-bromo-cyclic IDP-ribose). 8-Br-N(1)-cIDPR evoked Ca(2+) signalling in the human T-lymphoma cell line Jurkat and in primary rat T-lymphocytes. Ca(2+) signalling induced by 8-Br-N(1)-cIDPR consisted of Ca(2+) release and Ca(2+) entry. Whereas Ca(2+) release was sensitive to both the RyR (ryanodine receptor) blocker RuRed (Ruthenium Red) and the cADPR antagonist 8-Br-cADPR (8-bromo-cyclic ADP-ribose), Ca(2+) entry was inhibited by the Ca(2+) entry blockers Gd(3+) (gadolinium ion) and SKF-96365, as well as by 8-Br-cADPR. To unravel a potential role for TRPM2 in sustained Ca(2+) entry evoked by 8-Br-N(1)-cIDPR, TRPM2 was overexpressed in HEK (human embryonic kidney)-293 cells. However, though activation by H(2)O(2) was enhanced dramatically in those cells, Ca(2+) signalling induced by 8-Br-N(1)-cIDPR was almost unaffected. Similarly, direct analysis of TRPM2 currents did not reveal activation or co-activation of TRPM2 by 8-Br-N(1)-cIDPR. In summary, the sensitivity to the Ca(2+) entry blockers Gd(3+) and SKF-96365 is in favour of the concept of capacitative Ca(2+) entry, secondary to store depletion by 8-Br-N(1)-cIDPR. Taken together, 8-Br-N(1)-cIDPR appears to be the first cADPR agonist affecting Ca(2+) release and secondary Ca(2+) entry, but without effect on TRPM2