Detecting Poly (ADP-Ribose) In Vitro and in Cells Using PAR Trackers.

ADP-ribosylation (ADPRylation) is a reversible posttranslational modification resulting in the covalent attachment of ADP-ribose (ADPR) moieties on substrate proteins. Naturally occurring protein motifs and domains, including WWEs, PBZs (PAR binding zinc fingers), and macrodomains, act as "readers" for protein-linked ADPR. Although recombinant, antibody-like ADPR detection reagents containing these readers have facilitated the detection of ADPR, they are limited in their ability to capture the dynamic nature of ADPRylation. Herein, we describe the preparation and use of poly(ADP-ribose) (PAR) Trackers (PAR-Ts)-optimized dimerization-dependent or split-protein reassembly PAR sensors containing a naturally occurring PAR binding domain fused to both halves of dimerization-dependent GFP (ddGFP) or split nano luciferase (NanoLuc), respectively. We also describe how these tools can be used for the detection and quantification of PAR levels in biochemical assays with extracts and in living cells. These protocols will allow users to explore the broad utility of PAR-Ts for detecting PAR in various experimental and biological systems.

Development and characterization of new tools for detecting poly(ADP-ribose) in vitro and in vivo.

ADP-ribosylation (ADPRylation) is a reversible post-translation modification resulting in the covalent attachment of ADP-ribose (ADPR) moieties on substrate proteins. Naturally occurring protein motifs and domains, including WWEs, PBZs, and macrodomains, act as 'readers' for protein-linked ADPR. Although recombinant, antibody-like ADPR detection reagents containing these readers have facilitated the detection of ADPR, they are limited in their ability to capture the dynamic nature of ADPRylation. Herein, we describe and characterize a set of poly(ADP-ribose) (PAR) Trackers (PAR-Ts)-optimized dimerization-dependent or split-protein reassembly PAR sensors in which a naturally occurring PAR binding domain, WWE, was fused to both halves of dimerization-dependent GFP (ddGFP) or split Nano Luciferase (NanoLuc), respectively. We demonstrate that these new tools allow the detection and quantification of PAR levels in extracts, living cells, and living tissues with greater sensitivity, as well as temporal and spatial precision. Importantly, these sensors detect changes in cellular ADPR levels in response to physiological cues (e.g., hormone-dependent induction of adipogenesis without DNA damage), as well as xenograft tumor tissues in living mice. Our results indicate that PAR Trackers have broad utility for detecting ADPR in many different experimental and biological systems.

Intranasal corticosteroids for allergic rhinitis.

Intranasal corticosteroids are accepted as safe and effective first-line therapy for allergic rhinitis. Several intranasal corticosteroids are available: beclomethasone dipropionate, budesonide, flunisolide, fluticasone propionate, mometasone furoate, and triamcinolone acetonide. All are efficacious in treating seasonal allergic rhinitis and as prophylaxis for perennial allergic rhinitis. In general, they relieve nasal congestion and itching, rhinorrhea, and sneezing that occur in the early and late phases of allergic response, with studies showing almost complete prevention of late-phase symptoms. The rationale for topical intranasal corticosteroids in the treatment of allergic rhinitis is that adequate drug concentrations can be achieved at receptor sites in the nasal mucosa. This leads to symptom control and reduces the risk of systemic adverse effects. Adverse reactions usually are limited to the nasal mucosa, such as dryness, burning and stinging, and sneezing, together with headache and epistaxis in 5-10% of patients regardless of formulation or compound. Differences among agents are limited to potency, patient preference, dosing regimens, and delivery, device and vehicle.