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Purpose of Investigation The purpose of this study was to study the expression of adenosine diphosphate ribosylation factor GTPase-activating protein 3 (ArfGAP3) in the anterior vaginal wall of patients with pelvic organ prolapse (POP). Materials and Methods From July 2016 to July 2018, the anterior vaginal wall of 31 POP patients (pelvic organ prolapse quantification [POP-Q] II-III [n = 10] and POP-Q IV [n = 21]) with pelvic floor dysfunction-related symptoms who underwent vaginal hysterectomy were enrolled in POP group in the Department of Gynecology of Wuhan University People’s Hospital. The anterior vaginal wall of 28 non-POP patients who underwent vaginal hysterectomy was selected as control group. The expression of 3 groups was determined by immunohistochemical staining, Western blotting, and quantitative real-time fluorescence polymerase chain reaction. Results The expression levels of ArfGAP3 of POP-Q II-III and POP-Q IV groups were lower than the control group (P < 0.05), and there were significant differences between POP-Q II-III and POP-Q IV groups (P < 0.05). Conclusions The expression of ArfGAP3 in the anterior vaginal wall of POP patients decreased, which was related to the pathogenesis and clinical grading of POP.

International audience; Poly(ADP-ribose) polymerases (PARPs/ARTDs) use nicotinamide adenine dinucleotide (NAD +) to catalyse the synthesis of a long branched poly(ADPribose) polymer (PAR) attached to the acceptor amino acid residues of nuclear proteins. PARPs act on single-and double-stranded DNA breaks by recruiting DNA repair factors. Here, in in vitro biochemical experiments, we found that the mammalian PARP1 and PARP2 proteins can directly ADP-ribosylate the termini of DNA oligonucleotides. PARP1 preferentially catalysed covalent attachment of ADP-ribose units to the ends of recessed DNA duplexes containing 3-cordycepin, 5-and 3phosphate and also to 5-phosphate of a singlestranded oligonucleotide. PARP2 preferentially ADPribosylated the nicked/gapped DNA duplexes containing 5-phosphate at the double-stranded termini. PAR glycohydrolase (PARG) restored native DNA structure by hydrolysing PAR-DNA adducts generated by PARP1 and PARP2. Biochemical and mass spectrometry analyses of the adducts suggested that PARPs utilise DNA termini as an alternative to 2-hydroxyl of ADP-ribose and protein acceptor residues to catalyse PAR chain initiation either via the 2 ,1-O-glycosidic ribose-ribose bond or via phosphodiester bond formation between C1 of ADPribose and the phosphate of a terminal deoxyribonucleotide. This new type of post-replicative modification of DNA provides novel insights into the molecular mechanisms underlying biological phenomena of ADP-ribosylation mediated by PARPs.

A common strategy organisms have for controlling biological processes in a cell is to decorate important proteins with a chemical tag, such as a phosphate, methyl, or acetyl group. One of the most complex and fragile of these so-called posttranslational modifications is known as adenosine diphosphate ribosylation, or ADPr. This modification is used by many pathogens, including the causative agent of cholera, which uses ADPr to orchestrate lysis of intestinal cells. In mammals, the tag is involved in DNA repair, and malfunctions in ADPr decoration can lead to cancer. Despite ADPr’s importance, researchers know little about its precise molecular mechanisms or the specific amino acids ADPr decorates. To remedy this situation, a team led by Ivan Matic of the Max Planck Institute for Biology of Ageing has developed a mass spectrometry technique to identify and quantify ADPr in cells (Nat. Chem. Biol. 2016, DOI: 10.1038/nchembio.2180). The method reveals that histone

Acute and chronic treatments of mice with the glutathione-depleting agent, L-buthionine-(SR)-sulfoximine (BSO), impaired the mineralocorticoid receptor (MR)-dependent biological response by inhibiting aldosterone binding. This steroid-binding inhibition was fully reversed when reducing agents were added to kidney cytosol obtained from mice treated for 5 h, but it was only partially reversed in cytosol obtained from mice treated for 10 days. Although the oligomeric structure of the MR-hsp90 heterocomplex was always unaffected, a decreased amount of MR protein was evidenced after the long term treatment. Such a deleterious effect was correlated with a post-translational modification of MR, as demonstrated by an increased level of receptor carbonylation. In addition, a failure at the elongation/termination step was also observed during the receptor translation process in a reticulocyte lysate system. Thus, a high polyribosomes/monomers ratio and both increased proteolysis and decreased ADP-ribosylatable concentration of elongation factor 2 (EF-2) were shown. Importantly, similar observations were also performed in vivo after depletion of glutathione. Notwithstanding the EF-2 functional disruption, not all renal proteins were equally affected as the MR. Interestingly, both EF-2 and MR expressed in old mice were similarly affected as in L-buthionine-(SR)-sulfoximine-treated young mice. We therefore propose that a dramatic depletion of glutathione in kidney cells mimics the cumulative effect of aging which, at the end, may lead to a renal mineralocorticoid dysfunction.

Adenosine diphosphate-ribosyltransferase (ADPRT) and poly-ADP-ribose glycohydrolase (poly-ADPRG) activities were investigated in the different structures of bovine lenses. These activities and protein ADP ribosylation were detected only in the lens epithelium proliferative layer. The poly-ADPR glycohydrolase activity decreased, but the poly-ADPR polymerase activity increased during aging. In lens epithelial cells of older animals, the poly-ADP-ribose level and average chain length decreased but the chain number increased. Involvement of DNA break accumulation during aging in the increase of ADPRT activity of lens epithelial cells is discussed.