Poly(ADP-ribose) Polymerase-1 (PARP1) in Atherosclerosis: From Molecular Mechanisms to Therapeutic Potential

Poly(ADP-ribosyl)ation reactions, carried out by poly(ADP-ribose) polymerases (PARPs/ARTDs), are reversible posttranslational modifications impacting on numerous cellular processes (e.g., DNA repair, transcription, metabolism, or immune functions). PARP1 (EC 2.4.2.30), the founding member of PARPs, is particularly important for drug development for its role in DNA repair, cell death, and transcription of proinflammatory genes. Recent studies have established a novel concept that PARP1 is critically involved in the formation and destabilization of atherosclerotic plaques in experimental animal models and in humans. Reduction of PARP1 activity by pharmacological or molecular approaches attenuates atherosclerotic plaque development and enhances plaque stability as well as promotes the regression of pre-established atherosclerotic plaques. Mechanistically, PARP1 inhibition significantly reduces monocyte differentiation, macrophage recruitment, Sirtuin 1 (SIRT1) inactivation, endothelial dysfunction, neointima formation, foam cell death, and inflammatory responses within plaques, all of which are central to the pathogenesis of atherosclerosis. This article presents an overview of the multiple roles and underlying mechanisms of PARP1 activation (poly(ADP-ribose) accumulation) in atherosclerosis and emphasizes the therapeutic potential of PARP1 inhibition in preventing or reversing atherosclerosis and its cardiovascular clinical sequalae

A mikrobiom és a rák

Az emberi szervezet legtöbb szerve és kompartmentje nem steril, ezekben új generációs szekvenálási eljárásokkal bakteriális DNS vagy RNS mutatható ki. Az egy adott kompartmentben kimutatható baktérium örökítőanyag összességét metagenomnak, a transzkriptek összességét meta- transzkriptomnak, a baktériumok összességét pedig mikrobiomnak nevezzük. A mikrobiom összetétele megváltozik neoplasztikus betegségekben, amit onkobiózisnak nevezünk, az így kialakult fajösszetételt pedig onkobiomnak. A daganatok jelentős része kolonizálódik, és a daganatokban található baktériumok elősegítik a daganat növekedését, illetve fejlődését. A daganattól távoli kompartmentek (például bél) is áteshetnek onkobiotikus transzformáción. A bélmikrobiom onkobiotikus transzformációja során csökken a bélmikrobiom metabolikus kapacitása és több citosztatikus bakteriális metabolit szintézise lecsökken, ami a daganatsejtek proliferációjához és a metasztázisok képződéséhez vezet. A bélmikrobiom immunológiai tulajdonságai alapvetően meghatározzák azt, hogy az immunrendszer mennyiben tolerogén a daganatsejtekkel szemben, így elsődleges a daganatimmunitás szempontjából. Az onkobiózis önmagában nem indukál daganatokat, azonban elősegítheti növekedésüket és metasztázisképző képességüket. A baktériumoknak fontos szerepe van az antineoplasztikus terápia sikerességében, illetve a mellékhatások kialakításában

Oncobiosis and Microbial Metabolite Signaling in Pancreatic Adenocarcinoma

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Taxamat: automated biodiversity data management tool – implications for microbiome studies

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PARP1 Inhibition Augments UVB-Mediated Mitochondrial Changes-Implications for UV-Induced DNA Repair and Photocarcinogenesis

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The role of bile acids in carcinogenesis

Bile acids are soluble derivatives of cholesterol produced in the liver that subsequently undergo bacterial transformation yielding a diverse array of metabolites. The bulk of bile acid synthesis takes place in the liver yielding primary bile acids; however, other tissues have also the capacity to generate bile acids (e.g. ovaries). Hepatic bile acids are then transported to bile and are subsequently released into the intestines. In the large intestine, a fraction of primary bile acids is converted to secondary bile acids by gut bacteria. The majority of the intestinal bile acids undergo reuptake and return to the liver. A small fraction of secondary and primary bile acids remains in the circulation and exert receptor-mediated and pure chemical effects (e.g. acidic bile in oesophageal cancer) on cancer cells. In this review, we assess how changes to bile acid biosynthesis, bile acid flux and local bile acid concentration modulate the behavior of different cancers. Here, we present in-depth the involvement of bile acids in oesophageal, gastric, hepatocellular, pancreatic, colorectal, breast, prostate, ovarian cancer. Previous studies often used bile acids in supraphysiological concentration, sometimes in concentrations 1000 times higher than the highest reported tissue or serum concentrations likely eliciting unspecific effects, a practice that we advocate against in this review. Furthermore, we show that, although bile acids were classically considered as pro-carcinogenic agents (e.g. oesophageal cancer), the dogma that switch, as lower concentrations of bile acids that correspond to their serum or tissue reference concentration possess anticancer activity in a subset of cancers. Differences in the response of cancers to bile acids lie in the differential expression of bile acid receptors between cancers (e.g. FXR vs. TGR5). UDCA, a bile acid that is sold as a generic medication against cholestasis or biliary surge, and its conjugates were identified with almost purely anticancer features suggesting a possibility for drug repurposing. Taken together, bile acids were considered as tumor inducers or tumor promoter molecules; nevertheless, in certain cancers, like breast cancer, bile acids in their reference concentrations may act as tumor suppressors suggesting a Janus-faced nature of bile acids in carcinogenesis