Poly(ADP-ribose) polymerase inhibitor, 3-aminobenzamide, protects against experimental immune ovarian failure in mice

Effect of hydroxy groups on X-ray-induced reactions of azo benzene derivatives

Caged compounds whose chemical bonds are cleavable by specific stimuli are useful tools for life science research because they facilitate control of various biological activities spatiotemporally. Although caged compounds activatable by hard X-rays can be employed for control in deep tissue owing to the high bio-permeability of X-rays, chemical bond cleavage by ionizing radiation has not been investigated adequately. Previously, we demonstrated that an azo bond tethered to a rhodamine scaffold can be efficiently cleaved by hydrated electrons, which is one of the radiolysis products of water, to release rhodamine. In this study, we synthesized novel azo benzene derivatives, AZO1-4, which can release 3-aminobenzamide (3-ABA), a poly (ADP-ribose) polymerase (PARP) inhibitor, and hydroxy groups or amino groups were introduced into them in order to assess the substituent effect on azo bond cleavage. While the amount of 3-ABA was nearly the same for all the azo compounds, decomposition of azo compounds increased according to the number of hydroxy groups. Furthermore, a methoxyl-radical-adding product was detected from AZO2. These results suggested that the hydroxy group accelerates not azo bond cleavage but the other decomposition pathway.

Poly-ADP-ribose polymerase (PARP) inhibitors and ovarian function

Poly-ADP-ribose polymerase (PARP) plays an important role in DNA damage detection and repair. PARP inhibitors (PARPi) are a novel class of targeted agents used widely in the treatment of female cancer patients with BRCA mutations, including younger patients. However, the impact of PARPi on ovarian function remains a considerable problem in clinical practice. In this review article, we summarize the current understanding of PARPi's effects on the function of ovary and discuss their potential underlying mechanisms, highlighting the significance of further investigation on the criterion for ovarian failure and its preventive approaches during PARPi treatment.

Design, synthesis and evaluation of potential inhibitors for poly(ADP-ribose) polymerase members 1 and 14

Poly(ADP-ribose) polymerase (PARP) members PARP1 and PARP14 belong to an 18-member superfamily of post-translational modifying enzymes. A library of 9 novel non-NAD analog amine compounds was designed, synthesized and evaluated for inhibitory activity against PARP1 and PARP14. Both in silico studies and in vitro assays identified compound 2 as a potential PARP1 inhibitor, inhibiting activity by 93 ± 2% (PARP14 inhibition: 0 ± 6%), and 7 as a potential PARP14 inhibitor, inhibiting activity by 91 ± 2% (PARP1 inhibition: 18 ± 4%), at 10-μm concentration. Key in silico interactions with TYR907 in PARP1 and TYR1620 and TYR1646 in PARP14 have been identified. Compound 2 and compound 7 have been identified as potential leads for the development of selective PARP inhibitors.

Mechanistic perspective of protective effects of resveratrol against cisplatin-induced ovarian injury in rats: emphasis on anti-inflammatory and anti-apoptotic effects

Chemotherapeutic platinum-containing drugs are widely used to treat a variety of cancer types; however, they cause ovarian failure and infertility. The aim of this study is to investigate the molecular mechanism underlying the potential protective effect of resveratrol against cisplatin-induced ovarian damage in a rat model. Female rats were given either cisplatin (6 mg/kg, i.p., once per week for two consecutive weeks) and/or resveratrol (10 mg/kg, orally for 17 days). Follicular development, ovarian function markers, as well as apoptotic and inflammatory markers were assessed 24 h after the last resveratrol dose. Resveratrol ameliorated the marked follicular loss and the significant reduction in anti-Müllerian hormone (AMH) level triggered by cisplatin. Mechanistically, cisplatin elicited a potent inflammatory response in ovarian tissue as evidenced by the elevated expression of tumor necrosis factor, nuclear factor kappa-B, and proinflammatory enzymes. Co-treatment with resveratrol inhibited the elevation in inflammatory mediators induced by cisplatin. Further, cisplatin switched on the apoptotic machinery in ovarian tissues via increasing the expression of both cytochrome c and caspase-3 which was reversed upon resveratrol co-treatment. Resveratrol also counteracts the upregulating poly(ADP-ribose) polymerase expression which could attribute to the inflammatory and apoptotic effects of cisplatin. Resveratrol protects the ovary from cisplatin-induced toxicity through preventing the loss of the AMH-secreting granulosa cells, diminishing PARP-1 expression, and downregulating the inflammatory and apoptotic events implicated in cisplatin toxicity.

PARP1 Differentially Interacts with Promoter region of DUX4 Gene in FSHD Myoblasts

OBJECTIVE

The goal of the study is to identity proteins, which interact with the promoter region of double homeobox protein 4 (DUX4) gene known to be causative for the autosomal dominant disorder Facioscapulohumeral Muscular Dystrophy (FSHD).

METHODS

We performed a DNA pull down assay coupled with mass spectrometry analysis to identify proteins that interact with a DUX4 promoter probe in Rhabdomyosarcomca (RD) cells. We selected the top ranked protein poly (ADP-ribose) polymerase 1 (PARP1) from our mass spectrometry data for further ChIP-qPCR validation using patients' myoblasts. We then treated FSHD myoblasts with PARP1 inhibitors to investigate the role of PARP1 in the FSHD myoblasts.

RESULTS

In our mass spectrometry analysis, PARP1 was found to be the top ranked protein interacting preferentially with the DUX4 promoter probe in RD cells. We further validated this interaction by immunoblotting in RD cells (2-fold enrichment compared to proteins pulled down by a control probe, p<0.05) and ChIP-qPCR in patients' myoblasts (65-fold enrichment, p<0.01). Interestingly, the interaction was only observed in FSHD myoblasts but not in the control myoblasts. Upon further treatment of FSHD myoblasts with PARP1 inhibitors, we showed that treatment with a PARP1 inhibitor, 3-aminobenzamide (0.5 mM), for 24 h had a suppression of DUX4 (2.6 fold, p<0.05) and ZSCAN4, a gene previously shown to be upregulated by DUX4, (1.6 fold, p<0.01) in FSHD myoblasts. Treatment with fisetin (0.5 mM), a polyphenol compound with PARP1 inhibitory property, for 24 h also suppressed the expression of DUX4 (44.8 fold, p<0.01) and ZSCAN4 (2.2 fold, p<0.05) in the FSHD myoblasts. We further showed that DNA methyltransferase 1 (DNMT1), a gene regulated by PARP1 was also enriched at the DUX4 promoter in RD cells through immunoblotting (2-fold, p<0.01) and immortalized FSHD myoblasts (42-fold, p<0.01) but not control myoblasts through ChIP qPCR.

CONCLUSION

Our results showed that PARP1 and DNMT1 interacted with DUX4 promoter and may be involved in modulating DUX4 expression in FSHD.

Resveratrol inhibits inflammatory signaling implicated in ionizing radiation-induced premature ovarian failure through antagonistic crosstalk between silencing information regulator 1 (SIRT1) and poly(ADP-ribose) polymerase 1 (PARP-1)

This study hypothesized that resveratrol, a silencing information regulator 1 (SIRT1) activator, would counteract the inflammatory signaling associated with radiotherapy-induced premature ovarian failure (POF). Immature female Sprague-Dawley rats were subjected to a single dose of γ-radiation to induce POF and treated with resveratrol (25mg/kg) once daily for two weeks before and three days post irradiation. Resveratrol preserves the entire ovarian follicle pool manifested by increasing serum anti-Müllerian hormone (AMH) levels. Radiation triggered inflammatory process in the ovary through enhanced NF-κB and poly(ADP-ribose) polymerase (PARP)-1 expression which convinced the expression of inflammatory markers including IL-6, IL-8, and visfatin mRNA levels, as well as inducible nitric oxide synthase and cyclooxygenase-2 protein expression with a concomitant reduction in IL-10 mRNA levels. Resveratrol significantly counteracted the effect of radiation and upregulated the gene expression of peroxisome proliferator-activated receptor γ (PPAR-γ) and SIRT1. Resveratrol-activated SIRT1 expression was associated with inhibition of PARP-1 and NF-κB expression-mediated inflammatory cytokines. Our findings suggest that resveratrol restored ovarian function through increasing AMH levels, and diminishing ovarian inflammation, predominantly via upregulation of PPAR-γ and SIRT1 expression leading to inhibition of NF-κB provoked inflammatory cytokines.