scholarly journals Role of CD38 in Adipose Tissue: Tuning Coenzyme Availability?

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3734
Author(s):  
Andrea Benzi ◽  
Alessia Grozio ◽  
Sonia Spinelli ◽  
Laura Sturla ◽  
Andreas H. Guse ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Energy Metabolism ◽  
Nicotinamide Adenine Dinucleotide ◽  
Second Messenger ◽  
Nicotinamide Adenine ◽  
Degrading Enzymes ◽  
Cd38 Expression ◽  
Expression And Activity

Nicotinamide adenine dinucleotide (NAD+) is a fundamental molecule in the regulation of energy metabolism, representing both a coenzyme and a substrate for different NAD+ degrading enzymes. Among these enzymes, CD38 can be seen under two perspectives: as the enzyme synthesizing Ca2+-mobilizing second messenger, starting from NAD+, and as the major NAD+-consumer, to be inhibited to increase NAD+ levels. Indeed, the regulation of NAD+ availability is a key event during different processes. In this review, we examine the recent studies related to the modulation of CD38 expression and activity, and the consequent changes in NAD(P)(H), in adipose tissue, during inflammation and cold-induced thermogenesis.

scholarly journals Cellular and mitochondrial mechanisms of atrial fibrillation

2020 ◽  
Vol 115 (6) ◽  
Author(s):  
Fleur E. Mason ◽  
Julius Ryan D. Pronto ◽  
Khaled Alhussini ◽  
Christoph Maack ◽  
Niels Voigt
Keyword(s):  
Atrial Fibrillation ◽  
Nicotinamide Adenine Dinucleotide ◽  
Molecular Mechanisms ◽  
Treatment Options ◽  
Specific Treatment ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Mitochondrial Activity ◽  
Atp Production

AbstractThe molecular mechanisms underlying atrial fibrillation (AF), the most common form of arrhythmia, are poorly understood and therefore target-specific treatment options remain an unmet clinical need. Excitation–contraction coupling in cardiac myocytes requires high amounts of adenosine triphosphate (ATP), which is replenished by oxidative phosphorylation in mitochondria. Calcium (Ca2+) is a key regulator of mitochondrial function by stimulating the Krebs cycle, which produces nicotinamide adenine dinucleotide for ATP production at the electron transport chain and nicotinamide adenine dinucleotide phosphate for the elimination of reactive oxygen species (ROS). While it is now well established that mitochondrial dysfunction plays an important role in the pathophysiology of heart failure, this has been less investigated in atrial myocytes in AF. Considering the high prevalence of AF, investigating the role of mitochondria in this disease may guide the path towards new therapeutic targets. In this review, we discuss the importance of mitochondrial Ca2+ handling in regulating ATP production and mitochondrial ROS emission and how alterations, particularly in these aspects of mitochondrial activity, may play a role in AF. In addition to describing research advances, we highlight areas in which further studies are required to elucidate the role of mitochondria in AF.

scholarly journals Nicotinamide adenine dinucleotide as a photocatalyst

2019 ◽  
Vol 5 (7) ◽  
pp. eaax0501 ◽  
Author(s):  
Jinhyun Kim ◽  
Sahng Ha Lee ◽  
Florian Tieves ◽  
Caroline E. Paul ◽  
Frank Hollmann ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Metallic Nanoparticles ◽  
Chemical Conversion ◽  
Nicotinamide Adenine ◽  
Traditional Role ◽  
Life Span Extension ◽  
Redox Biocatalysis ◽  
Total Turnover ◽  
Prosthetic Groups

Nicotinamide adenine dinucleotide (NAD+) is a key redox compound in all living cells responsible for energy transduction, genomic integrity, life-span extension, and neuromodulation. Here, we report a new function of NAD+ as a molecular photocatalyst in addition to the biological roles. Our spectroscopic and electrochemical analyses reveal light absorption and electronic properties of two π-conjugated systems of NAD+. Furthermore, NAD+ exhibits a robust photostability under UV-Vis-NIR irradiation. We demonstrate photocatalytic redox reactions driven by NAD+, such as O2 reduction, H2O oxidation, and the formation of metallic nanoparticles. Beyond the traditional role of NAD+ as a cofactor in redox biocatalysis, NAD+ executes direct photoactivation of oxidoreductases through the reduction of enzyme prosthetic groups. Consequently, the synergetic integration of biocatalysis and photocatalysis using NAD+ enables solar-to-chemical conversion with the highest-ever-recorded turnover frequency and total turnover number of 1263.4 hour−1 and 1692.3, respectively, for light-driven biocatalytic trans-hydrogenation.

NAD(P)H oxidase–dependent platelet superoxide anion release increases platelet recruitment

Blood ◽  
2002 ◽  
Vol 100 (3) ◽  
pp. 917-924 ◽  
Author(s):  
Florian Krötz ◽  
Hae Young Sohn ◽  
Torsten Gloe ◽  
Stefan Zahler ◽  
Tobias Riexinger ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Thrombus Formation ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Human Platelets ◽  
Nicotinamide Adenine ◽  
Irreversible Aggregation ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Specific Peptide

Abstract Platelets, although not phagocytotic, have been suggested to release O2−. Since O2−-producing reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) oxidases can be specifically activated by certain agonists and are found in several nonphagocytotic tissues, we investigated whether such an enzyme is the source of platelet-derived O2−. We further studied which agonists cause platelet O2−release and whether platelet-derived O2− influences thrombus formation in vitro. Collagen, but not adenosine 5′-diphosphate (ADP) or thrombin, increased O2− formation in washed human platelets. This was a reduced nicotinamide adenine dinucleotide (NADH)–dependent process, as shown in platelet lysates. Consistent with a role of a platelet, NAD(P)H oxidase expression of its subunits p47phox and p67phoxand inhibition of platelet O2− formation by diphenylene-iodoniumchloride (DPI) and by the specific peptide-antagonist gp91ds-tat were observed. Whereas platelet-derived O2− did not influence initial aggregation, platelet recruitment to a preformed thrombus following collagen stimulation was significantly attenuated by superoxide dismutase (SOD) or DPI. It was also inhibited when ADP released during aggregation was cleaved by the ectonucleotidase apyrase. ADP in supernatants of collagen-activated platelets was decreased in the presence of SOD, resulting in lower ADP concentrations available for recruitment of further platelets. Exogenous O2−increased ADP- concentrations in supernatants of collagen-stimulated platelets and induced irreversible aggregation when platelets were stimulated with otherwise subthreshold concentrations of ADP. These results strongly suggest that collagen activation induces NAD(P)H oxidase–dependent O2− release in platelets, which in turn enhances availability of released ADP, resulting in increased platelet recruitment.

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