Distribution of superoxide dismutase 1 and glutathione peroxidase 1 in the cyclic canine endometrium

Effect of pyometra on vascularity alterations, oxidative stress, histopathology and inflammatory molecules in feline

This study aimed to investigate blood flow, hemodynamical features by Doppler ultrasound, the oxidative stress biomarkers from serum samples, and histopathology from uterine tissue, in healthy queens and queens with pyometra. Twenty queens were categorized into two groups, according to signs, history, and ultrasound findings, as pyometra and control healthy queens. Doppler ultrasonography, total antioxidant capacity (TAC), malondialdehyde (MDA), albumin, bacteriological isolation, histopathology, and immunohistochemistry of tumor necrosis factor-alpha (TNF-α) and nuclear factor kappa B (NF-κB) P65 were performed. Uterine diameter and thickness increased significantly in the pyometra group compared to control. Uterine peak velocity and flow rate were significantly higher in the control group. The pyometra group showed a significant decrease in albumin, TAC, and a significant increase in MDA. Fibrosis and mononuclear inflammatory cell infiltration were seen in the pyometra samples. The mean area percentage of TNF-α expression in the uteri of the pyometra group was higher. The expression of NF-κB P65 in the uteri in the pyometra group was significantly higher. Doppler ultrasonography can provide valuable information for diagnosing pyometra in queens by elevating the uterine thickness with reducing blood flow rate. Oxidative stress, TNF-α, and NF-κB expression alterations varied between pyometra and control groups.

Spatial and temporal expression profile of sex steroid receptors and antioxidant enzymes in the maternal-fetal interface of domestic cats

Sex steroids and antioxidant enzymes modulate uterine and placental physiology. Failures in the expression, signaling, and/or secretion of these mediators are associated with female infertility and gestational problems. However, there is no data on the expression profile of receptors for sex steroids and antioxidant enzymes in the maternal-fetal interface of domestic cats. Uterus and placenta samples from non-pregnant diestrus cats and cats in mid- and late pregnancy were used to analyze the protein and gene expression of the receptors for estrogen alpha (ERα), progesterone (PR), and androgen (AR) and the antioxidant enzymes superoxide dismutase 1 (SOD1), catalase, and glutathione peroxidase 1 (GPX1) by immunohistochemistry and qPCR. Higher uterine expression of ERα, Pr, and Sod1 was observed in the pregnant cats, especially in mid-pregnancy, compared to non-pregnant diestrus cats, as well as reduced endometrial catalase immunostaining. In the placenta, the mRNA expression of Erα, Pr, Ar, and Gpx1 was higher in late pregnancy in relation to mid-pregnancy. Moreover, weak or no placental expression was observed for catalase in mid- and late pregnancy, while strong immunostaining was observed for AR in trophoblasts and decidual cells in mid-pregnancy. The findings of this study demonstrated that pregnancy in female cats increases the uterine expression of sex steroid receptors and antioxidant enzymes, and that the placental expression of these mediators varies according to gestational age.

Estrogen and progesterone receptors and antioxidant enzymes are expressed differently in the uterus of domestic cats during the estrous cycle

Sex steroids and antioxidant enzymes are important in female sexual development and adequate modulation of the estrous cycle, pregnancy, and fetal development. Therefore, modifications in its signaling or expression in the genital system are associated with reproductive dysfunctions. However, the spatial-temporal expression profile of receptors for sex steroids and antioxidant enzymes in the uterus of domestic cats throughout the estrous cycle needs to be studied. Cats in proestrus/estrus (N = 6), diestrus, (N = 7), and anestrus (N = 6) were used to evaluate the uterine expression of estrogen alpha (ERα), progesterone (PR), and androgen (AR) receptors and of the antioxidant enzymes superoxide dismutase 1 (SOD1), catalase and glutathione peroxidase 1 (GPX1) by immunohistochemistry and qPCR. The uterus of cats in diestrus showed lower protein and mRNA expression of ERα and PR compared to proestrus/estrus and anestrus, mainly in the luminal and glandular epithelium and myometrium, different from catalase and SOD1, which showed higher expression in diestrus in relation to other phases of the cycle. GPX1, on the other hand, showed lower uterine gene expression in diestrus compared to proestrus/estrus and anestrus. No significant differences in AR expression were observed. In conclusion, ERα and PR sex steroid receptors and antioxidant enzymes are expressed differently in the uterus of domestic cats during the estrous cycle.

Increased Systemic Antioxidant Power Ameliorates the Aging-Related Reduction in Oocyte Competence in Mice

Ovarian aging is associated with elevated oxidative stress and diminished oocyte developmental competence. We aimed to determine the impact of systemic antioxidant treatment in aged mice. Female outbred CF-1 mice were aged for 9 months prior to an 8-week 45 mg Euterpe oleracea (açaí) daily supplement. The açaí treatment induced a threefold increase in serum antioxidant power (FRAP) compared to both young and aged mice (p < 0.0001). Compared to young mice, aged mice had fewer oocytes and reduced blastocyst development (p < 0.0001); açaí did not affect the oocyte numbers, but improved blastocyst formation (p < 0.05). Additionally, açaí alleviated the aging-related decrease in implantation potential (p < 0.01). The aged mice showed evidence of elevated ovarian ER stress (increased whole-ovary PDIA4 expression, granulosa cell and oocyte GRP78 expression, and oocyte PDIA4 protein), reduced oocyte mitochondrial quality (higher PRKN activation and mitochondrial DNA oxidative damage), and dysregulated uterine glandular epithelium. Antioxidant intervention was sufficient to lessen these effects of ovarian aging, likely in part by the upregulation of NRF2. We conclude that açaí treatment is a promising strategy to improve ER and mitochondrial function in the ovaries, thereby ameliorating the decreased oocyte competence that occurs with ovarian aging.

Exploration of the hepatoprotective effect and mechanism of magnesium isoglycyrrhizinate in mice with arsenic trioxide‑induced acute liver injury

Arsenic trioxide (ATO)-induced hepatotoxicity limits the therapeutic effect of acute myelogenous leukemia treatment. Magnesium isoglycyrrhizinate (MgIG) is a natural compound extracted from licorice and a hepatoprotective drug used in liver injury. It exhibits anti-oxidant, anti-inflammatory and anti-apoptotic properties. The aim of the present study was to identify the protective action and underlying mechanism of MgIG against ATO-induced hepatotoxicity. A total of 50 mice were randomly divided into five groups (n=10/group): Control; ATO; MgIG and high- and low-dose MgIG + ATO. Following continuous administration of ATO for 7 days, the relative weight of the liver, liver enzyme, histological data, antioxidant enzymes, pro-inflammatory cytokines, cell apoptosis and changes in Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2 (Keap1-Nrf2) signaling pathway were observed. MgIG decreased liver injury, decreased the liver weight and liver index, inhibited oxidative stress and decreased the activity of glutathione, superoxide dismutase and catalase, production of reactive oxygen species and levels of pro-inflammatory cytokines, including IL-1β, IL-6 and TNF-α. Western blotting showed a decrease in Bax and caspase-3. There was decreased cleaved caspase-3 expression and increased Bcl-2 expression. MgIG notably activated ATO-mediated expression of Keap1 and Nrf2 in liver tissue. MgIG administration was an effective treatment to protect the liver from ATO-induced toxicity. MgIG maintained the level of Nrf2 in the liver and protected the antioxidative defense system to attenuate oxidative stress and prevent ATO-induced liver injury.

Effects of Essential Trace Elements and Oxidative Stress on Endemic Arsenism Caused by Coal Burning in PR China

Few studies have investigated the association between essential trace elements and oxidative stress in environmental media and populations with endemic arsenism caused by coal burning. Element contents and oxidative stress indicators were measured. Moreover, the expression of genes related to the nuclear factor E2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)-antioxidant response element (ARE) signaling pathway and Nrf2-ARE binding ability is detected. The results show that the contents of arsenic, copper, iron, and chromium were increased in environmental media from the arsenism area compared with the control area; however, the selenium content decreased. The arsenic, iron, chromium, and copper contents and the copper/zinc ratio were also increased in the arsenic-exposed population; however, the selenium content decreased. The results also show that the concentrations of arsenic, iron, and chromium and the copper/zinc ratio increased gradually with the severity of arsenism. However, selenium concentrations decreased gradually with the severity of arsenism. The contents of malondialdehyde, 8-hydroxyldeoxyguanosine, and protein carbonyl in plasma increased, while the levels of sulfhydryl, thioredoxin reductase (TrxR), glutathione peroxidase (Gpx), and superoxide dismutase 1 (SOD1) decreased. The mRNA expression of Keap1 and TrxR1 decreased in the blood, while the mRNA expression of Nrf2, GPx1, and SOD1 increased. Moreover, the Nrf2 protein content and Nrf2-ARE binding ability increased, and the Keap1 protein content decreased. In conclusion, our data suggest that the increased arsenic content in environmental media and populations was accompanied by abnormal levels of essential trace elements. Insufficient selenium intake, copper, and chromium overload and a high copper/zinc ratio might be some of the causes of arsenism, which might be related to the Nrf2/Keap1-ARE signaling pathway.

Estrogen and progesterone dependent expression of visfatin/NAMPT regulates proliferation and apoptosis in mice uterus during estrous cycle

Visfatin is an adipokine which has an endocrine effect on reproductive functions and regulates ovarian steroidogenesis. There is scant information about the expression, regulation, and functions of visfatin in the mammalian uterus. The present study examined expression and localization of visfatin in the mouse uterus at various stages of the natural estrous cycle, effects of estrogen and progesterone on localization and expression of visfatin in the ovariectomised mouse uterus and effect of visfatin inhibition by a specific inhibitor, FK866 on proliferation and apoptosis in the uterus. Western blot analysis of visfatin showed high expression in proestrus and metestrus while it declined in estrus and diestrus. Immulocalization study also showed strong immunostaining in the cells of endometrium, myometrium, luminal and glandular epithelium during proestrus and metestrus that estrus and diestrus. The uterine visfatin expression closely related to the increased estrogen levels in proestrus and suppressed when progesterone rose to a high level in diestrus. The treatment with estrogen to ovariectomised mice up-regulates visfatin, PCNA, and active caspase3 whereas progesterone up-regulates PCNA and down-regulates visfatin and active caspase3 expression in mouse uterus. The co-treatment with estrogen and progesterone up-regulates visfatin and down-regulates PCNA and active caspase3. In vitro study showed endogenous visfatin inhibition by FK866 increased expression of PCNA and BCL2 increased catalase activity while FK866 treatment decreased expression of active caspase3 and BAX with decreased SOD and GPx activity. BrdU labeling showed that inhibition of visfatin modulates the uterine proliferation. This study showed that expression of visfatin protein is steroid dependent in mouse uterus which is involved in the regulation of proliferation and apoptosis via modulating antioxidant system in the uterus of mice during the reproductive cycle.

The PKCδ-Nrf2-ARE signalling pathway may be involved in oxidative stress in arsenic-induced liver damage in rats

Arsenic poisoning is a worldwide endemic disease that affects thousands of people. Growing evidence from animal, cell, and human studies indicates that arsenic has deleterious effects on the liver. Oxidative stress is considered the primary mechanism for arsenic toxicity in liver damage. However, the mechanisms remain unclear. In light of this fact, the main objective of this study was to investigate the effects of the protein kinase C delta-nuclear factor E2-related factor 2-antioxidant response element (PKCδ-Nrf2-ARE) signalling pathway on oxidative stress in liver damage. In the present study, we used a model of liver damage induced by coal-burning arsenic in rats, which was set up by our research group. The oxidative stress index and the transcription and protein expression levels of PKCδ, Nrf2, Keap1, SOD1, and GPx1 were detected, and then their correlation analyses were carried out. The results demonstrated that coal-burning arsenic can cause oxidative stress liver damage in rats, which may be related to the PKCδ-Nrf2-ARE signalling pathway. This study may provide a new pathway for studies of the mechanisms of arsenism.

Improved uterine immune mediators in Holstein cows supplemented with rumen-protected methionine and discovery of neutrophil extracellular traps (NET)

During the transition from prepartum to early lactation, dairy cows often experience negative energy balance (NEB) that may result in reproductive stress and decreased fertility. The objective of this study was to observe the effects of rumen-protected methionine (RPM) on plasma amino acid concentrations, uterine cytology, immunohistochemistry (IHC) of glutathione peroxidase 1 (GPX) and superoxide dismutase 1 (SOD), and to confirm neutrophil extracellular trap (NET) formation. Multiparous Holstein cows (n = 20) were randomly assigned to two treatments starting at 21 d before calving until 73 days in milk (DIM). Treatments were: CON (n = 9, no supplementation, TMR with a Lys:Met = 3.5:1) and MET (n = 11, TMR + Smartamine^® M with a Lys:Met = 2.8:1). Uterine endometrial biopsies, uterine cytology, and blood samples from the coccygeal artery or vein were collected at 15, 30, and 73 DIM. Blood plasma samples were analyzed for amino acids and metabolites. Uterine biopsies were analyzed for NET formation, neutrophil numbers, as well as GPX and SOD by IHC. Additionally, uterine cytology was analyzed for polymorphonuclear neutrophil (PMN) to epithelial cell percentage. Cows in CON had lower methionine plasma concentrations (18.05 ± 2.0 μM) than cows in MET (30.39 ± 1.6 μM). Cows in CON had greater cystine plasma concentrations (3.62 ± 0.3 μM) than cows in MET (2.8 ± 0.3 μM). No treatment differences were observed for SOD or GPX in the endometrium. Cows in CON tended to have a high score for positively immunolabeled GPX cells at 15 DIM than cows in MET. No treatment differences were observed for the percentage of PMN in uterine cytology, number of neutrophils, or extent of NET formation in the endometrium. A treatment by time interaction was observed for PMN percentage and the number of neutrophils: cows in MET tended to have greater PMN percentages than cows in CON at 15 DIM which decreased for subsequent days and cows in MET had greater neutrophil numbers in the endometrium at 30 DIM than cows in CON. In conclusion, dietary supplementation of RPM altered plasma amino acid concentrations and increased neutrophil infiltration in the postpartum period, suggesting improved uterine immunity.