Besides the well-known double-helical conformation, DNA is capable of folding into various noncanonical arrangements, such as G-quadruplexes (G4s) and i-motifs (iMs), whose occurrence in gene promoters, replication origins, and telomeres highlights the breadth of biological processes that they might regulate. Particularly, previous studies have reported that G4 and iM structures may play different roles in controlling gene transcription. Anyway, molecular tools able to simultaneously stabilize/destabilize those structures are still needed to shed light on what happens at the biological level.
View Article and Find Full Text PDFContrasting results exist on the association between CTLA-4 rs231775 and acute rejection in kidney transplant recipients. We herein conducted an updated systematic review with meta-analysis and trial sequential analysis (TSA) to clarify this relationship and to establish whether the current evidence is sufficient to draw firm conclusions. In addition, noteworthiness of significant pooled odds ratios (ORs) was estimated by false positive report probability (FPRP).
View Article and Find Full Text PDFIn the present study we systematically re-analyzed results from meta-analyses and genome-wide association studies (GWASs) to assess the credibility of genetic associations with acute rejection risk in renal transplantation. A comprehensive literature search was performed on PubMed, Web of Knowledge, Cochrane library, and Open Grey up to July 2019. Methodological quality of systematic meta-analyses was assessed by the AMSTAR tool.
View Article and Find Full Text PDFDespite the isolation of hundreds of bioactive isocyanides from terrestrial fungi and bacteria as well as marine organisms, the isocyanide functionality has so far received little attention from a medicinal chemistry standpoint. The widespread tenet that isocyanides are chemically and metabolically unstable has restricted bioactivity studies to their antifouling properties and technical applications. In order to confirm or refute this idea, the hepatic metabolism of six model isocyanides was investigated.
View Article and Find Full Text PDFAll cells require sustained intracellular energy flux, which is driven by redox chemistry at the subcellular level. NAD, its phosphorylated variant NAD(P), and its reduced forms NAD(P)/NAD(P)H are all redox cofactors with key roles in energy metabolism and are substrates for several NAD-consuming enzymes ( poly(ADP-ribose) polymerases, sirtuins, and others). The nicotinamide salvage pathway, constituted by nicotinamide mononucleotide adenylyltransferase (NMNAT) and nicotinamide phosphoribosyltransferase (NAMPT), mainly replenishes NAD in eukaryotes.
View Article and Find Full Text PDFMulticomponent transformations, such as Ugi and Passerini reactions, allow for the fast synthesis of libraries of medium complexity, avoiding the formation of waste residues and significantly reducing time and money expenditure. Although the Ugi reaction has found a vast number of uses in medicinal chemistry, the employment of the Passerini reaction has received scant attention due to the formation of an α-acyloxyamide, which hardly resists the hydrolytic enzymes in the body. On the other hand, an overlooked possibility with the Passerini products is to exploit the presence of an ester group in the design and synthesis of soft drugs.
View Article and Find Full Text PDFCancer induces alteration of hematopoiesis to fuel disease progression. We report that in tumor-bearing mice the macrophage colony-stimulating factor elevates the myeloid cell levels of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD salvage pathway, which acts as negative regulator of the CXCR4 retention axis of hematopoietic cells in the bone marrow. NAMPT inhibits CXCR4 through a NAD/Sirtuin 1-mediated inactivation of HIF1α-driven gene transcription, leading to mobilization of immature myeloid-derived suppressor cells (MDSC) and enhancing their production of suppressive nitric oxide.
View Article and Find Full Text PDFIn recent years, channels that mediate store-operated calcium entry (SOCE, i.e., the ability of cells to sense a decrease in endoplasmic reticulum luminal calcium and induce calcium entry across the plasma membrane) have been associated with a number of disorders, spanning from immune disorders to acute pancreatitis and have been suggested to be druggable targets.
View Article and Find Full Text PDFOld multicomponent reactions are still a source of inspiration for discovering novel combinations of three or more reactants. A simple idea is to replace one of the educts of a known multicomponent reaction with another functional group and still be able to mimic the same reactivity. Following this line of thought, we report a three-component reaction in which isocyanides are able to open the epoxide intermediate of the Bargellini reaction affording 3-carboxamido-isobutyric acids in yields of 47-95%.
View Article and Find Full Text PDFA novel series of 4-aryl-3-cyano-2-(3-hydroxyphenyl)-6-morpholino-pyridines have been designed as potential phosphatidylinositol-3-kinase (PI3K) inhibitors. The compounds have been synthesized using the Guareschi reaction to prepare the key 4-aryl-3-cyano-2,6-dihydroxypyridine intermediate. A different selectivity according to the nature of the aryl group has been observed.
View Article and Find Full Text PDFIn the present manuscript, starting from the 1,4-benzodiazepin-2-one nucleus, a privileged structure in medicinal chemistry, we have synthesized a novel class of cis-locked combretastatins named combreatabenzodiazepines. They show similar cytotoxic and antitubulin activity compared to combretastatin A-4 in neuroblastoma cells, showing a better pharmacokinetic profile. This class of compounds has therefore the potential for further development as antitubulin agents.
View Article and Find Full Text PDF(Z)-Arylchlorooximes and α-isocyanoacetamides undergo a smooth reaction to produce 1,3-oxazol-2-oxime derivatives in good yields. Opening of the oxazole ring and deoximation reaction give a facile access to aryl-α-ketoamide amides, a class of privileged scaffolds in medicinal chemistry and important synthetic intermediates in organic chemistry.
View Article and Find Full Text PDFNicotinamide phoshophoribosyltransferase (NAMPT) plays a key role in the replenishment of the NAD pool in cells. This in turn makes this enzyme an important player in bioenergetics and in the regulation of NAD-using enzymes, such as PARPs and sirtuins. Furthermore, there is now ample evidence that NAMPT is secreted and has a role as a cytokine.
View Article and Find Full Text PDFAs part of an effort to identify novel selective modulators of sirtuins, we synthesized and tested several isosteres and constrained analogues of nicotinamide. Biological data suggest that compound 2 is selective for Sirt3 over Sirt1 and Sirt2.
View Article and Find Full Text PDFNAD is an essential coenzyme involved in numerous metabolic pathways. Its principal role is in redox reactions, and as such it is not heavily "consumed" by cells. Yet a number of signaling pathways that bring about its consumption have recently emerged.
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