NAD(P)H:quinone oxidoreductase 1 is induced by progesterone in cardiomyocytes

The Impact of High Adiposity on Endometrial Progesterone Response and Metallothionein Regulation

CONTEXT

Obesity is a disease with deleterious effects on the female reproductive tract, including the endometrium.

OBJECTIVE

We sought to understand the effects of excess adipose on the benign endometrium.

METHODS

A physiologic in vitro coculture system was developed, consisting of multicellular human endometrial organoids, adipose spheroids, and menstrual cycle hormones. Native human endometrial tissue samples from women with and without obesity were also analyzed. Benign endometrial tissues from premenopausal women ages 33 to 53 undergoing hysterectomy were obtained following written consent at Northwestern University Prentice Women's Hospital, Chicago, Illinois. Gene expression, protein expression, chromatin binding, and expression of DNA damage and oxidative damage markers were measured.

RESULTS

Under high adiposity conditions, endometrial organoids downregulated endometrial secretory phase genes, suggestive of an altered progesterone response. Progesterone specifically upregulated the metallothionein (MT) gene family in the epithelial cells of endometrial organoids, while high adiposity significantly downregulated the MT genes. Silencing MT genes in endometrial epithelial cells resulted in increased DNA damage, illustrating the protective role of MTs. Native endometrium from women with obesity displayed increased MT expression and oxidative damage in the stroma and not in the epithelium, indicating the cell-specific impact of obesity on MT genes.

CONCLUSION

Taken together, the in vitro and in vivo systems used here revealed that high adiposity or obesity can alter MT expression by decreasing progesterone response in the epithelial cells and increasing oxidative stress in the stroma.

Nrf2 Activation in Chronic Kidney Disease: Promises and Pitfalls

The nuclear factor erythroid 2-related factor 2 (Nrf2) protects the cell against oxidative damage. The Nrf2 system comprises a complex network that functions to ensure adequate responses to redox perturbations, but also metabolic demands and cellular stresses. It must be kept within a physiologic activity range. Oxidative stress and alterations in Nrf2-system activity are central for chronic-kidney-disease (CKD) progression and CKD-related morbidity. Activation of the Nrf2 system in CKD is in multiple ways related to inflammation, kidney fibrosis, and mitochondrial and metabolic effects. In human CKD, both endogenous Nrf2 activation and repression exist. The state of the Nrf2 system varies with the cause of kidney disease, comorbidities, stage of CKD, and severity of uremic toxin accumulation and inflammation. An earlier CKD stage, rapid progression of kidney disease, and inflammatory processes are associated with more robust Nrf2-system activation. Advanced CKD is associated with stronger Nrf2-system repression. Nrf2 activation is related to oxidative stress and moderate uremic toxin and nuclear factor kappa B (NF-κB) elevations. Nrf2 repression relates to high uremic toxin and NF-κB concentrations, and may be related to Kelch-like ECH-associated protein 1 (Keap1)-independent Nrf2 degradation. Furthermore, we review the effects of pharmacological Nrf2 activation by bardoxolone methyl, curcumin, and resveratrol in human CKD and outline strategies for how to adapt future Nrf2-targeted therapies to the requirements of patients with CKD.

Cytoprotective Effect of Vitamin D on Doxorubicin-Induced Cardiac Toxicity in Triple Negative Breast Cancer

Background: Doxorubicin (Dox) is a first-line treatment for triple negative breast cancer (TNBC), but its use may be limited by its cardiotoxicity mediated by the production of reactive oxygen species. We evaluated whether vitamin D may prevent Dox-induced cardiotoxicity in a mouse TNBC model. Methods: Female Balb/c mice received rodent chow with vitamin D₃ (1500 IU/kg; vehicle) or chow supplemented with additional vitamin D₃ (total, 11,500 IU/kg). the mice were inoculated with TNBC tumors and treated with intraperitoneal Dox (6 or 10 mg/kg). Cardiac function was evaluated with transthoracic echocardiography. The cardiac tissue was evaluated with immunohistochemistry and immunoblot for levels of 4-hydroxynonenal, NAD(P)H quinone oxidoreductase (NQO1), C-MYC, and dynamin-related protein 1 (DRP1) phosphorylation. Results: At 15 to 18 days, the mean ejection fraction, stroke volume, and fractional shortening were similar between the mice treated with vitamin D + Dox (10 mg/kg) vs. vehicle but significantly greater in mice treated with vitamin D + Dox (10 mg/kg) vs. Dox (10 mg/kg). Dox (10 mg/kg) increased the cardiac tissue levels of 4-hydroxynonenal, NQO1, C-MYC, and DRP1 phosphorylation at serine 616, but these increases were not observed with vitamin D + Dox (10 mg/kg). A decreased tumor volume was observed with Dox (10 mg/kg) and vitamin D + Dox (10 mg/kg). Conclusions: Vitamin D supplementation decreased Dox-induced cardiotoxicity by decreasing the reactive oxygen species and mitochondrial damage, and did not decrease the anticancer efficacy of Dox against TNBC.

Systematic review of the nuclear factor erythroid 2-related factor 2 (NRF2) system in human chronic kidney disease: alterations, interventions, and relation to morbidity

BACKGROUND

NRF2 and its effectors NAD(P)H:quinoneoxidoreductase 1 (NQO1) and heme oxygenase 1 (HO-1) are of interest in kidney disease. We therefore reviewed studies about their status in patients with chronic kidney disease (CKD).

METHODS

We undertook systematic searches of PubMed and EMBASE databases. Alterations of NRF2, NQO1 and HO-1 in CKD, their responses to interventions and their relation to clinically relevant parameters were reported.

RESULTS

We identified 1373 articles, of which 32 studies met the inclusion criteria. NRF2 levels were decreased in the majority of analyses of CKD patients. Half of the analyses showed a similar or increased NQO1 level vs. control, whereas NQO1 was decreased in half of the analyses. Most of the studies reported either an increased or similar HO-1 level in CKD patients compared to controls. For patients with CKD stages 1-4, studies reported positive correlations to markers of kidney disease severity. Also, positive associations of NQO1/HO-1 levels to inflammation and comorbidities were reported. One third of the studies showed discordant changes between gene expression and protein level of NRF2 system components. Two thirds of intervention studies (50% dietary, such as using resistant starch) reported an increase of NRF2, NQO1, or HO-1.

CONCLUSIONS

In patients with CKD, NRF2 expression was downregulated, while NQO1 and HO-1 showed varying alterations related to inflammation, comorbidities, and severity of kidney damage. Interventions that increased NRF2 system components were described, but their effectiveness and clinical relevance require further clinical studies of high quality. Research on gene expression together with protein analyses is indispensable to understand NRF2 system alterations in CKD.

Ascorbic Acid and Alpha-Tocopherol Contribute to the Therapy of Polycystic Ovarian Syndrome in Mouse Models

Polycystic ovary syndrome (PCOS) affects up to 10% of women within reproductive ages and has been a cause of infertility and poor quality of life. Alteration in the oxidant-antioxidant profile occurs in PCOS. This study, therefore, investigates the contribution of ascorbic acid (AA) and alpha-tocopherol(ATE) on different PCOS parameters. The mifepristone and letrozole models were used, and young mature female mice were randomly assigned to groups of six per group. On PCOS induction with either mifepristone or letrozole, mice were administered AA and ATE at doses ranging from 10-1000mg/kg to 0.1-1000 mg/kg in the respective models. Vaginal cytology, body weights, and temperature, as well as blood glucose, testosterone, and insulin levels, were measured. Total antioxidant capacity and malondialdehyde levels were analyzed. Determination of gene expression of some reactive oxygen species and histomorphological analysis on the ovaries and uteri were performed. At the end of the experiments, AA and ATE restored reproductive cycling, with AA being more effective. AA and ATE increased fasting blood glucose but had no significant effect on serum insulin levels. AA decreased testosterone levels, but ATE caused slight increases. AA and ATE both increased total antioxidant capacity and decreased malondialdehyde levels. AA and ATE also slightly upregulated the mRNA expressions of catalase, superoxide dismutase, and heme oxygenase 1 mainly. AA and ATE also decreased ovarian weight and mostly resolved cysts in the ovaries and congestion in the uterus. This study has shown that AA and ATE are beneficial in the therapy of PCOS.

A Comparative Assessment Study of Known Small-Molecule Keap1-Nrf2 Protein-Protein Interaction Inhibitors: Chemical Synthesis, Binding Properties, and Cellular Activity

Inhibiting the protein-protein interaction (PPI) between the transcription factor Nrf2 and its repressor protein Keap1 has emerged as a promising strategy to target oxidative stress in diseases, including central nervous system (CNS) disorders. Numerous non-covalent small-molecule Keap1-Nrf2 PPI inhibitors have been reported to date, but many feature suboptimal physicochemical properties for permeating the blood-brain barrier, while others contain problematic structural moieties. Here, we present the first side-by-side assessment of all reported Keap1-Nrf2 PPI inhibitor classes using fluorescence polarization, thermal shift assay, and surface plasmon resonance-and further evaluate the compounds in an NQO1 induction cell assay and in counter tests for nonspecific activities. Surprisingly, half of the compounds were inactive or deviated substantially from reported activities, while we confirm the cross-assay activities for others. Through this study, we have identified the most promising Keap1-Nrf2 inhibitors that can serve as pharmacological probes or starting points for developing CNS-active Keap1 inhibitors.

Expression of NAD(P)H quinone dehydrogenase 1 (NQO1) is increased in the endometrium of women with endometrial cancer and women with polycystic ovary syndrome

OBJECTIVE

Women with a prior history of polycystic ovary syndrome (PCOS) have an increased risk of endometrial cancer (EC).

AIM

To investigate whether the endometrium of women with PCOS possesses gene expression changes similar to those found in EC.

DESIGN AND METHODS

Patients with EC, PCOS and control women unaffected by either PCOS or EC were recruited into a cross-sectional study at the Nottingham University Hospital, UK. For RNA sequencing, representative individual endometrial biopsies were obtained from women with EC, PCOS and a woman unaffected by PCOS or EC. Expression of a subset of differentially expressed genes identified by RNA sequencing, including NAD(P)H quinone dehydrogenase 1 (NQO1), was validated by quantitative reverse transcriptase PCR validation (n = 76) and in the cancer genome atlas UCEC (uterine corpus endometrioid carcinoma) RNA sequencing data set (n = 381). The expression of NQO1 was validated by immunohistochemistry in EC samples from a separate cohort (n = 91) comprised of consecutive patients who underwent hysterectomy at St Mary's Hospital, Manchester, between 2011 and 2013. A further 6 postmenopausal women with histologically normal endometrium who underwent hysterectomy for genital prolapse were also included. Informed consent and local ethics approval were obtained for the study.

RESULTS

We show for the first that NQO1 expression is significantly increased in the endometrium of women with PCOS and EC. Immunohistochemistry confirms significantly increased NQO1 protein expression in EC relative to nonmalignant endometrial tissue (P < .0001).

CONCLUSIONS

The results obtained here support a previously unrecognized molecular link between PCOS and EC involving NQO1.

Dual character of flavonoids in attenuating and aggravating ischemia-reperfusion-induced myocardial injury

The concept that flavonoids exert cardioprotection against myocardial ischemia-reperfusion (I/R) injury has been acknowledged by a large body of evidence. However, recent studies reported cardiotoxic effects of certain flavonoids, while the underlying mechanisms have remained largely elusive. Flavonoids have been demonstrated to activate aryl hydrocarbon receptor (Ahr), which is implicated in an array of cell signaling processes. The present study examined the cardioprotective roles of quercetin (Qu) and β-naphthoflavone (β-NF) against I/R injury and explored whether the underlying mechanism proceeds via molecular signaling downstream of Ahr. An oxygen glucose deprivation/reoxygenation (OGD/R) model of I/R was established in myocardial H9c2 cells in the absence or presence of Qu or β-NF. Qu as well as β-NF reversed OGD/R-induced overproduction of reactive oxygen species by increasing the anti-oxidative capacity of the cells and protected them from lethal injury, as demonstrated by a decreased cell death rate, lactate hydrogenase leakage and caspase-3 activity as determined by flow cytometry, colorimetric assay and western blot analysis, respectively. Immunocytochemistry, co-immunoprecipitation and western blot assays collectively revealed that Qu and β-NF engendered the translocation of Ahr from the cytoplasm into the cell nucleus, where binding of Ahr with the Ahr nuclear translocator (ARNT) blocked its binding to hypoxia-inducible factor (HIF)-1α, which inhibited the cardioprotection of HIF-1α, including the induction of nitric oxide (NO) and inhibition of vascular endothelial growth factor (VEGF) production. Ahr knockdown recovered the binding of ARNT to HIF-1α and the generation of NO and VEGF. The results of the present study suggested a dual character of Qu and β-NF in the process of myocardial I/R.

α- and β-Naphthoflavone synergistically attenuate H2O2-induced neuron SH-SY5Y cell damage

Previous studies have demonstrated an association between neurological diseases and oxidative stress (OS). Naphthoflavone is a synthetic derivative of naturally occurring flavonoids that serves an important role in the treatment and prevention of OS-related diseases. The current study was designed to apply α- and β-Naphthoflavone individually and in combination to counteract the detrimental effects of OS on neurons in vitro. Neuronal SH-SY5Y cells were subjected to 20 µM H₂O₂, followed by exposure to 20 µM α-Naphthoflavone and/or 10 µM β-Naphthoflavone. Results indicated that α- and β-Naphthoflavone effectively antagonized the apoptosis-promoting effect of H₂O₂ on neuronal SH-SY5Y cells, and that β-Naphthoflavone significantly (P<0.05) reversed H₂O₂-inhibited cell viability. Notably, co-treatment of α- and β-Naphthoflavone reversed the H₂O₂-induced apoptosis rate elevation and cell viability reduction. Further analysis demonstrated that H₂O₂ inhibited the activities of antioxidant enzymes including catalase, superoxide dismutase and glutathione peroxidase, but this was reversed by the co-treatment with α- and β-Naphthoflavone and selectively enhanced by the treatment with α- or β-Naphthoflavone. H₂O₂-stimulated p38 mitogen-activated protein kinase activation was repressed following treatment with α- and/or β-Naphthoflavone, along with a decreased expression of the apoptosis-related factors and inhibited caspase-3 activation. In conclusion, co-treatment with α- and β-Naphthoflavone minimized H₂O₂-led neuron damage compared with treatment with α- or β-Naphthoflavone, suggesting a synergetic effect between α- and β-Naphthoflavone. This indicates that utilizing α- and β-Naphthoflavone together in the clinical setting may provide a novel therapeutic for neurological disease.

An overview of the mechanisms and novel roles of Nrf2 in cardiovascular diseases

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a basic leucine zipper (bZIP) transcription factor of the cap'n'collar (CNC) family that is present in various organs. The cardiovascular system (CVS) is susceptible to a spectrum of diseases that are strongly associated with increased risks of mortality and morbidity, and studies have demonstrated that Nrf2 has a pivotal role in protection against cardiovascular diseases (CVDs). Areas covered: Nrf2 is a basic protective molecule that guards against CVD by attenuating oxidative stress, mitochondrial dysfunction, and inflammation. Initially, we briefly introduce the biological characteristics of Nrf2 and the newly discovered Neh7 domain. Next, we discuss the concrete roles of Nrf2 in the CVS and enumerate some related upstream molecules and downstream targets. Lastly, we expand our focus to the behaviors of Nrf2 in CVDs and discuss potential research directions. Expert opinion: Although certain studies have cast doubt on the positive actions of Nrf2 in the CVS, Nrf2 is a pivotal endogenous molecule for defense against CVD. The review compiled here may serve as a broad and comprehensive reference for the roles of Nrf2 in the CVS, with the aim of facilitating the design of new drugs and clinical therapies for CVDs.

The synthetic progestin norgestrel modulates Nrf2 signaling and acts as an antioxidant in a model of retinal degeneration

Retinitis pigmentosa (RP) is one of the most common retinal degenerative conditions affecting people worldwide, and is currently incurable. It is characterized by the progressive loss of photoreceptors, in which the death of rod cells leads to the secondary death of cone cells; the cause of eventual blindness. As rod cells die, retinal-oxygen metabolism becomes perturbed, leading to increased levels of reactive oxygen species (ROS) and thus oxidative stress; a key factor in the secondary death of cones. In this study, norgestrel, an FDA-approved synthetic analog of progesterone, was found to be a powerful neuroprotective antioxidant, preventing light-induced ROS in photoreceptor cells, and subsequent cell death. Norgestrel also prevented light-induced photoreceptor morphological changes that were associated with ROS production, and that are characteristic of RP. Further investigation showed that norgestrel acts via post-translational modulation of the major antioxidant transcription factor Nrf2; bringing about its phosphorylation, subsequent nuclear translocation, and increased levels of its effector protein superoxide dismutase 2 (SOD2). In summary, these results demonstrate significant protection of photoreceptor cells from oxidative stress, and underscore the potential of norgestrel as a therapeutic option for RP.

Differential Regulation of Bcl-xL Gene Expression by Corticosterone, Progesterone, and Retinoic Acid

Corticosterone (CT), progesterone (PG), and retinoic acid (RA) are capable of inhibiting Doxorubicin (Dox) from inducing apoptosis in rat cardiomyocytes. Mechanistically, CT, PG, and RA induce increases of Bcl-xL protein and mRNA, and activate a 3.2 kb bcl-x gene promoter. CT and RA, but not PG, induced the activity of a 0.9 kb bcl-x promoter, containing sequences for AP-1 and NF-kB binding. RA, but not CT or PG, induced NF-kB activation. CT, but not PG or RA, induced AP-1 activation, and induction of the 0.9 kb bcl-x reporter by CT was inhibited by dominant negative c-Jun TAM-67 or removal of AP-1 binding site. Therefore, although CT, PG, and RA all induce Bcl-xL mRNA and protein, three independent mechanisms are in operation: while CT induces Bcl-xL via AP-1 transcription factor, and RA induces NF-kB activation and bcl-x promoter activity, PG induces Bcl-xL via a mechanism independent of NF-kB or AP-1.

The decrease of NAD(P)H:quinone oxidoreductase 1 activity and increase of ROS production by NADPH oxidases are early biomarkers in doxorubicin cardiotoxicity

CONTEXT

Doxorubicin cardiotoxicity displays a complex and multifactorial progression.

OBJECTIVE

Identify early biochemical mechanisms leading to a sustained imbalance of cellular bioenergetics.

METHODS

Measurements of the temporal evolution of selected biochemical markers after treatment of rats with doxorubicin (20 mg/kg body weight).

RESULTS

Doxorubicin treatment increased lipid oxidation, catalase activity and production of H₂O₂ by Nox-NADPH oxidases, and down-regulated

NAD(P)H

quinone oxidoreductase-1 prior eliciting changes in reduced glutathione, protein carbonyls and protein nitrotyrosines. Alterations of mitochondrial and myofibrillar bioenergetics biomarkers were detected only after this oxidative imbalance was established.

CONCLUSIONS

NAD(P)H

quinone oxidoreductase-1 activity and increase of hydrogen peroxide production by NADPH oxidases are early biomarkers in doxorubicin cardiotoxicity.

Protective Effect of Progesterone during Pregnancy against Ovarian Cancer

There have been several epidemiologic studies supporting the protective role of pregnancy, although the mechanism is not clear. High level of progesterone, which is crucial in maintaining pregnancy, has been supposed to be one of the causative factors. Progesterone is produced at the corpus luteum in the early pregnancy and the placenta in the late pregnancy period. In several experimental studies, progesterone was reported to induce apoptosis of ovarian cancer cells through intrinsic and extrinsic pathways. In addition, progesterone has been shown to exert its anticancer effect through genomic and non-genomic action. The objective of this review is to discuss the protective mechanism of pregnancy against ovarian cancer focusing on the steroid hormone, progesterone.