Biochemical Markers of Oxidative Stress in Saudi Women with Recurrent Miscarriage

Melatonin-mediated actions and circadian functions that improve implantation, fetal health and pregnancy outcome

This review summarizes data related to the potential importance of the ubiquitously functioning antioxidant, melatonin, in resisting oxidative stress and protecting against common pathophysiological disorders that accompany implantation, gestation and fetal development. Melatonin from the maternal pineal gland, but also trophoblasts in the placenta, perhaps in the mitochondria, produce this molecule as a hedge against impairment of the uteroplacental unit. We also discuss the role of circadian disruption on reproductive disorders of pregnancy. The common disorders of pregnancy, i.e., stillborn fetus, recurrent fetal loss, preeclampsia, fetal growth retardation, premature delivery, and fetal teratology are all conditions in which elevated oxidative stress plays a role and experimental supplementation with melatonin has been shown to reduce the frequency or severity of these conditions. Moreover, circadian disruption often occurs during pregnancy and has a negative impact on fetal health; conversely, melatonin has circadian rhythm synchronizing actions to overcome the consequences of chronodisruption which often appear postnatally. In view of the extensive findings supporting the ability of melatonin, an endogenously-produced and non-toxic molecule, to protect against experimental placental, fetal, and maternal pathologies, it should be given serious consideration as a supplement to forestall the disorders of pregnancy. Until recently, the collective idea was that melatonin supplements should be avoided during pregnancy. The data summarized herein suggests otherwise. The current findings coupled with the evidence, published elsewhere, showing that melatonin is highly protective of the fertilized oocyte from oxidative damage argues in favor of its use for improving pregnancy outcome generally.

Untargeted metabolomics analysis reveals the metabolic disturbances and exacerbation of oxidative stress in recurrent spontaneous abortion

BACKGROUND

Recurrent spontaneous abortion (RSA) is characterized by the occurrence of two or more consecutive spontaneous abortions, with a rising prevalence among pregnant women and significant implications for their physical and mental well-being. The multifaceted etiology of RSA has posed challenges in unraveling the molecular mechanisms underlying that underlie its pathogenesis. Oxidative stress and immune response have been identified as pivotal factors in the development of its condition.

METHODS

Eleven serum samples from healthy pregnant women and 17 from RSA were subjected to liquid chromatography/mass spectrometry (LC-MS) analysis. Multivariate statistical analysis was employed to excavate system-level characterization of the serum metabolome. The measurement of seven oxidative stress products, namely superoxide dismutase (SOD), catalase (CAT), malonaldehyde (MDA), glutathione (GPx), glutathione peroxidase (GSH), oxidized glutathione (GSSG), heme oxygenase (HO-1), was carried out using ELISA.

RESULTS

Through the monitoring of metabolic and lipid alternations during RSA events, we have identified 816 biomarkers that were implicated in various metabolic pathways, including glutathione metabolism, phosphonate and phosphinate metabolism, nucleotide metabolism, sphingolipid metabolism, lysine degradation and purine metabolism, etc. These pathways have been found to be closely associated with the progression of the disease. Our finding indicated that the levels of MDA and HO-1 were elevated in the RSA group compared to the control group, whereas SOD, CAT and GPx exhibited a contrary pattern. However, no slight difference was observed in GSH and GSSG levels between the RSA group and the control group.

CONCLUSION

The manifestation of RSA elicited discernible temporal alternations in the serum metabolome and biochemical markers linked to the metabolic pathways of oxidative stress and immune response. Our investigation furnished a more comprehensive analytical framework encompassing metabolites and enzymes associated with oxidative stress. This inquiry furnished a more nuanced comprehension of the pathogenesis of RSA and established the ground work for prognostication and prophylaxis.

Effects of unpredictable chronic mild stress on the cellular redox state and mitochondrial energy homeostasis in rat adipose tissue: A comprehensive metabolic study

Unpredictable chronic mild stress (UCMS) leads to variable metabolic effects. Oxidative stress (OS) of adipose tissue (AT) and mitochondrial energy homeostasis is little investigated. This work studied the effects of UCMS on OS and the antioxidant/redox status in AT and mitochondrial energy homeostasis in rats. Twenty-four male Wistar rats (180-220 g) were divided into two equal groups; the normal control (NC) group and the UCMS group which were exposed to various stresses for 28 days. An indirect calorimetry machine was used to measure volumes of respiratory gases (VO2 & VCO2 ), total energy expenditure (TEE), and food intake (FI). The AT depots were collected, weighed, and used for measuring activities and gene expression of key antioxidant enzymes (GPx1, SOD, CAT, GR, GCL, and GS), OS marker levels including superoxide anion (SA), peroxynitrite radical (PON), nitric oxide (NO), hydrogen peroxide (H2 O2 ), lipid peroxides (LPO), t-protein carbonyl content (PCC), and reduced/oxidized glutathione levels (GSH, GSSG). Additionally, AT mitochondrial fractions were used to determine the activities of the tricarboxylic acid cycle (TCA) cycle enzymes (CS, α-KGDH, ICDH, SDH, MDH), respiratory chain complexes I-III, II-III, IV, the nicotinamide coenzymes NAD+ , NADH, and ATP/ADP levels. Compared with the NC group, the UCMS group showed very significantly increased OS marker levels, lowered antioxidant enzyme activities and gene expression, as well as lowered TCA cycle and respiratory chain activity and NAD+ , NADH, and ATP levels (p < .001 for all comparisons). Besides, the UCMS group had lowered TEE and insignificant FI and weight gain. In conclusion, AT of the UCMS-subjected rats showed a state of disturbed redox balance linked to disrupted energy homeostasis producing augmentation of AT.

Oxidative/nitrosative stress increased the risk of recurrent pregnancy loss-Taiwan Recurrent Pregnancy Loss and Environmental Study (TREPLES)

OBJECTIVE

Oxidative stress biomarkers (OSBs) may be strongly associated with disease progression and recurrent pregnancy loss (RPL). However, the research on associations of most OSBs (e.g., 8-nitroguanine [8-NO2Gua] and 4-hydroxy-2-nonenal-mercapturic acid [HNE-MA]) with RPL is limited. Therefore, we aimed to investigate the effect of OSBs exposure on RPL risk by performing a case-control study.

MATERIAL AND METHODS

We use our established dataset, Taiwan Recurrent Pregnancy Loss and Environmental Study (TREPLES), which included 514 Taiwanese reproductive age women (aged 20-50 years; 397 cases and 117 controls) from National Cheng Kung University Hospital. RPL is clinically defined by a history of two or more consecutive miscarriages, where a miscarriage is defined as the termination of pregnancy before 20 weeks of gestation. The urinary levels of several OSBs (e.g., 8-hydroxy-2'-deoxyguanosine [8-OHdG], 8-NO2Gua, 8-isoprostaglandin F2α [8-isoPGF2α], and HNE-MA) and malondialdehyde (MDA) were measured using isotope dilution liquid chromatography-tandem mass spectrometry and thiobarbituric acid reactive substances, respectively.

RESULTS

The median levels of 8-NO2Gua (6.15 vs. 3.76 ng/mL) and HNE-MA (30.12 and 21.54 ng/mL) were significantly higher in the RPL group than in the control group. By categorizing the OSBs data into tertiles, after we adjusted for age and urine creatinine levels discovered that the RPL risk associated with 8-NO2Gua and HNE-MA levels in the third tertile were approximately 2 times higher than those in the first tertile (8-NO2Gua, adjusted OR = 3.27, 95 % CI = 1.66-6.43; HNE-MA, adjusted OR = 1.96, 95 % CI = 1.05-3.64; p < 0.05). These findings suggest that the oxidative stress biomarkers of 8-NO2Gua and HNE-MA are risk factors for RPL.

CONCLUSION

Our findings indicate that specific OSBs are associated with an increased RPL risk, suggesting that reducing OSB levels can improve RPL risk. Nevertheless, more studies on preventive medicine are required to understand the exposure sources and adverse outcome pathways of OSBs associated with RPL.

Disrupted Balance of the Oxidant-Antioxidant System in the Pathophysiology of Female Reproduction: Oxidative Stress and Adverse Pregnancy Outcomes

The significance of oxidative stress in the pathophysiology of male reproductive processes has been closely studied in the last two decades. Recently, it has become clear that oxidative stress can lead to numerous pathological conditions during female reproductive processes as well, contributing to the development of endometriosis, polycystic ovary syndrome and various forms of infertility. During pregnancy, physiological generation of reactive oxygen species (ROS) occurs in association with several developmental processes including oocyte maturation and implantation. An overproduction of ROS can lead to disturbances in fetal development and increases the risk for missed abortion, intrauterine growth restriction, pre-eclampsia, premature delivery and gestational diabetes. Our review focuses on the etiological role of the disrupted oxidant-antioxidant system during human gestation as it relates to adverse pregnancy outcomes.

Exposure of Reproductive-Aged Women to Multiple Metals and Its Associations with Unexplained Recurrent Miscarriage

Exposure to heavy metals exerts toxic effects on female reproduction and embryo development. This study examined the exposure of patients with unexplained recurrent miscarriage (uRM) to multiple metals and the correlations among exposures to different metals. A total of 275 participants were enrolled, including 43 healthy women without previous miscarriage (the control group) and 232 uRM women (the case group); among these uRM women, 159 had two miscarriages (2M), 42 had three miscarriages (3M) and 31 had four or more miscarriages (≥4M). A total of 22 elements were measured in serum samples via inductively coupled plasma-mass spectrometry. The levels of calcium (104.37 mg/L vs. 92.65/93.02/92.61/92.47 mg/L) and selenium (131.85 µg/L vs. 117.80/118.04/115.88/124.35 µg/L) were higher in the controls than in the total uRM group and the 2M, 3M and ≥4M subgroups. The level of vanadium was significantly lower in the controls than in the total uRM group (0.15 µg/L vs. 0.23 µg/L), and the level of lead was lower in the controls than that in the total uRM group and the 2M, 3M and ≥4M subgroups (0.01 µg/L vs. 0.28/0.18/0.63/0.34 µg/L). After adjusting for age, body mass index and education level, calcium and selenium exposure were consistently negatively associated with miscarriage, while lead exposure was positively associated with miscarriage. In addition, the correlations among exposures to different metals slightly differed between the control and uRM groups. Therefore, changes in some metal elements in the blood might be related to the risk of uRM.

Effects of amygdalin on ferroptosis and oxidative stress in diabetic retinopathy progression via the NRF2/ARE signaling pathway

Oxidative stress has been involved in the pathogenesis of diabetic retinopathy (DR). Amygdalin is an effective component of bitter almond that exhibits excellent antioxidant properties. We explored the effects of amygdalin on ferroptosis and oxidative stress in high-glucose (HG)-stimulated human retinal endothelial cells (HRECs) via the NRF2/ARE pathway. HG-stimulated HRECs were used to establish a DR model. Cell viability was evaluated using the MTT assay. The release of lactate dehydrogenase was used to evaluate cell toxicity. The protein levels of NRF2, NQO1, and HO-1 were detected using western blotting. The GSH, GSSG, GPX4, SOD, CAT, MDA, and Fe2+ levels in the HRECs were also detected. Flow cytometry was used to detect reactive oxygen species (ROS) using a fluorescent probe. Immunofluorescence staining was performed to detect NRF2 expression. The results revealed that HG stimulation decreased the levels of GSH, GPX4, SOD, and CAT but increased those of MDA, ROS, GSSG, and Fe2+ in HRECs. Ferrostatin-1 treatment reversed the effects of HG stimulation, whereas erastin aggravated these effects. Amygdalin treatment relieved HG-induced injury in HRECs. Amygdalin treatment promoted the nuclear transport of NRF2 in HG-stimulated HRECs. NQO1 and HO-1 levels were upregulated in HG-stimulated HRECs after amygdalin treatment. An inhibitor of NRF2 reversed the effects of amygdalin. Therefore, amygdalin treatment inhibited ferroptosis and oxidative stress in HG-stimulated HRECs by activating the NRF2/ARE signaling pathway.

Omega-3 fatty acid supplements and recurrent miscarriage: A perspective on potential mechanisms and clinical evidence

Recurrent miscarriage (RM) affects approximately 1%-5% of couples worldwide. Due to its complicated etiologies, the treatments for RM also vary greatly, including surgery for anatomic factors such as septate uterus and uterine adhesions, thyroid modulation drugs for hyperthyroidism and hypothyroidism, and aspirin and low molecular weight heparin for antiphospholipid syndrome. However, these treatment modalities are still insufficient to solve RM. Omega-3 fatty acids are reported to modulate the dysregulation of immune cells, oxidative stress, endocrine disorders, inflammation, etc., which are closely associated with the pathogenesis of RM. However, there is a lack of a systematic description of the involvement of omega-3 fatty acids in treating RM, and the underlying mechanisms are also not clear. In this review, we sought to determine the potential mechanisms that are highly associated with the pathogenesis of RM and the regulation of omega-3 fatty acids on these mechanisms. In addition, we also highlighted the direct and indirect clinical evidence of omega-3 fatty acid supplements to treat RM, which might encourage the application of omega-3 fatty acids to treat RM, thus improving pregnancy outcomes.

Impacts of PAH accumulation on reproductive hormones, indices of oxidative stress and BPDE-albumin adduct in women with recurrent pregnancy loss

Chronic exposure to Poly aromatic hydrocarbons (PAHs) may be associated with adverse pregnancy outcomes. Disruption of hormonal and redox balance by toxic PAH metabolites may interfere with successful pregnancy leading to miscarriage. The association of exposure to PAH contaminated mussel via the dietary route with perturbations in reproductive hormones, biomarkers of oxidative stress, and PAH metabolites were assessed in women with recurrent pregnancy loss (RPL). Furthermore, an analysis of the concentration of PAHs in environmentally relevant bivalve animals was performed to preliminary get insights into the levels of these pollutants in the environment. Seventy-six women (20-35 years) were categorized into 18 fertile women without RPL (control), and Groups I, II, and III comprising 24, 18, and 16 women with RPL (2, 3, and > 3 abortions respectively) were studied. Whole blood samples were collected for the estimation of malondialdehyde (MDA), catalase, reduced glutathione (GSH), glutathione-S-transferase (GST), progesterone (P4), follicle-stimulating hormone (FSH), benzo[a]pyren-7,8-dihydrodiol-9,10-epoxide-albumin adduct (BPDE-albumin) and urine for α-naphthol and β-naphthol. Two species of mussel Donax trunculus and Andar aduloii samples were collected for the estimation of 16 priority PAHs. The concentration of PAHs exceeding the maximum limits was observed in the two species of mussels studied. Higher levels of BPDE-albumin, MDA, GST, α and β-naphthol and lower GSH, catalase, FSH, and P4 were observed in women with RPL (Groups I-III) compared to controls (p =  < 0.001). Negative associations were observed between BPDE-albumin and catalase (r = - 0.276, p = 0.036), and GSH (r = - 0.331, p = - 0.011) only in women with RPL. Collectively, our findings indicate a possible association of chronic PAH accumulation with recurrent pregnancy loss in women.

Graphical abstract

High PAH exposure in pregnant women is associated with 10-epoxide-albumin adduct formation and high MDA levels in their sera. On the other hand, PAH exposure in those women led to a decrease in their GSH, catalase, P4, and FSH sera levels. These findings indicate that PAH exposure can exert different physiological effects in pregnant women leading to a high level of abortion in those women.

Inflammatory Cytokines, Redox Status, and Cardiovascular Diseases Risk after Weight Loss via Bariatric Surgery and Lifestyle Intervention

Background and Objectives: Obesity is a chronic inflammatory condition and is considered a major risk factor for cardiovascular disease (CVD). The effects of obesity management via sleeve gastrectomy (SG) and lifestyle intervention (LS) on inflammatory cytokines, redox status, and CVD risk were studied in this work. Materials and Methods: A total of 92 participants (18 to 60 years old) with obesity (BMI ≥ 35 kg/m² were divided into two groups: the bariatric surgery (BS) group (n = 30), and the LS group (n = 62). According to the achievement of 7% weight loss after 6 months, the participants were allocated to either the BS group, the weight loss (WL) group, or the weight resistance (WR) group. Assessments were performed for body composition (by bioelectric impedance), inflammatory markers (by ELISA kits), oxidative stress (OS), antioxidants (by spectrophotometry), and CVD risk (by the Framingham risk score (FRS) and lifetime atherosclerotic cardiovascular disease risk (ASCVD)). Measurements were taken before and after six months of either SG or LS (500 kcal deficit balanced diet, physical activity, and behavioral modification). Results: At the final assessment, only 18 participants in the BS group, 14 participants in the WL group, and 24 participants in the WR group remained. The loss in fat mass (FM) and weight loss were greatest in the BS group (p < 0.0001). Levels of IL-6, TNF-a, MCP-1, CRP, and OS indicators were significantly reduced in the BS and WL groups. The WR group had significant change only in MCP-1 and CRP. Significant reductions in the CVD risk in the WL and BS groups were detected only when using FRS rather than ASCVD. The FM loss correlated inversely with FRS-BMI and ASCVD in the BS group, whereas in the WL group, FM loss correlated only with ASCVD. Conclusions: BS produced superior weight and fat mass loss. However, both BS and LS produced a similar reduction in the inflammatory cytokines, relief of OS indicators, and enhancement of antioxidant capacity, and consequently reduced the CVD risk.

Impact of some heavy metal pollution on idiopathic recurrent spontaneous abortion.. [DOI: 10.21203/rs.3.rs-2355371/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Environmental pollution with heavy metal (HM) may be associated with human reproductive failure where pollutants are accumulated in marine organisms and sediment and subsequently transferred to man through food chain. Oxidative stress and disruption of homeostatic regulation of reproductive hormones has been implicated in HM induced reproductive toxicity. The HM, indices of oxidative stress, reproductive hormone and red cell indices in women with recurrent pregnancy loss (RPL) were assessed in this study. Methods Seventy-six women (20–35 years) categorized into 18 fertile women without RPL (control group), and Groups I, II and III comprising 24, 18 and 16 women with RPL (2, 3, and > 3 abortions respectively) were studied. Whole blood samples were collected for the estimation of cadmium (Cd), lead (Pb), metallothionein (rbcMT), malondialdehyde (MDA), reduced glutathione (GSH), progesterone, haemoglobin (Hb), mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH). Mussel samples were collected for Cd, Pb and metallothionein (MT) estimation. Results The cadmium content of mussels were above the maximum limit. Women with RPL (Groups I-III) had higher Cd, Pb, rbcMT and MDA and lower catalase, GSH, P4, Hb, MCV and MCH compared to Group I (p = < 0.001). Negative associations were observed between Cd and catalase (r=-0.320, p = 0.014), GSH (r=-0.359, p=-0.006) and MCV (r=-0.391, p=-0.002) respectively and between Pb and GSH (r=-0.501, p = < 0.001), Hb (r=-0.289, p = 0.028), MCV (r=-0.394, p = 0.002) and MCH (r=-0.277, p = 0.036) respectively in women with RPL. Positive correlations were observed between Cd and Pb (r = 0.533, p = < 0.001), rbcMT with Cd (r = 0.312, p = 0.017), Pb (r = 0.488, p = < 0.000) and MDA (r = 0.282, p = 0.032) respectively in women with RPL. Conclusion Elevated cadmium levels in mussels, metallothionein, MDA and reduced antioxidants, progesterone and red cell indices observed in women with RPL suggest that HM induced oxidative stress and hormonal imbalance may be implicated in recurrent pregnancy loss.

Progress of oxidative stress in endometrium decidualization

The difficulty in maintaining the balance between oxides and antioxidants causes a phenomenon named oxidative stress. Oxidative stress often leads to tissue damage and participates in the pathogenesis of a series of diseases. Decidua provides the 'soil' for embryo implantation, and the normal decidualization shows the characteristics of strong antioxidation. Once the mechanism of antioxidant stress goes awry, it will lead to a series of pregnancy-related diseases. In recent years, more and more studies have shown that oxidative stress is involved in pregnancy-related diseases caused by abnormal decidualization of the endometrium. In order to have a more comprehensive understanding of the role of oxidative stress in decidual defect diseases, this paper reviews the common decidual defect diseases in conjunction with relevant regulatory molecules, in order to arouse thinking about the importance of oxidative stress, and to provide more theoretical basis for the aetiology of decidual defects.

Variation of the Oxidative Profile in Pregnant Women With and Without Gestational Complications

INTRODUCTION

Oxidative stress is closely related to the pathophysiology of gestation, where the placenta is susceptible to oxidative damage, contributing to the onset of gestational complications. Currently, few studies evaluate the use of oxidative markers for prediction of risk of gestational complications. However, there are some reports that suggest these biomarkers as potential prognostic biomarkers. Therefore, the objective of this study was to compare the biomarkers of oxidative stress from gestations with and without complications, and also evaluate the delta of variation in these markers from the first gestational trimester.

MATERIAL AND METHODS

A total of 45 pregnant women were evaluated during the three gestational trimesters, of whom 15 developed gestational complications by the end of gestation. The evaluated oxidative damage markers were thiobarbituric acid reactive substances and nitric oxide dosage. Evaluation of the antioxidant system was performed by the quantification of vitamin C, sulfhydryl groups, total antioxidant capacity, plasmatic iron reduction ability, the evaluation of catalase and delta-aminolevulinate dehydratase enzymatic activity.

RESULTS

According to the results, the markers of oxidative damage are increased, and the antioxidant profile decreased, in the third trimester of complicated pregnancies as compared to uncomplicated pregnancies. Moreover, the delta of variation in both oxidative damage markers and antioxidants was higher in complicated gestations as compared to uncomplicated gestations, thus suggesting a higher oxidative stress in pregnancies with complications.

CONCLUSIONS

Oxidative stress parameters appear altered in pregnant women with gestational complications. The markers to oxidative stress can be possible biomarkers, helping in understanding mechanisms underlying the associations between complications during pregnancy and various health outcomes.

Comprehensive investigations of key mitochondrial metabolic changes in senescent human fibroblasts

There is a paucity of detailed data related to the effect of senescence on the mitochondrial antioxidant capacity and redox state of senescent human cells. Activities of TCA cycle enzymes, respiratory chain complexes, hydrogen peroxide (H₂O₂), superoxide anions (SA), lipid peroxides (LPO), protein carbonyl content (PCC), thioredoxin reductase 2 (TrxR2), superoxide dismutase 2 (SOD2), glutathione peroxidase 1 (GPx1), glutathione reductase (GR), reduced glutathione (GSH), and oxidized glutathione (GSSG), along with levels of nicotinamide cofactors and ATP content were measured in young and senescent human foreskin fibroblasts. Primary and senescent cultures were biochemically identified by monitoring the augmented cellular activities of key glycolytic enzymes including phosphofructokinase, lactate dehydrogenase, and glycogen phosphorylase, and accumulation of H₂O₂, SA, LPO, PCC, and GSSG. Citrate synthase, aconitase, α-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, and complex I-III, IIIII, and IV activities were significantly diminished in P25 and P35 cells compared to P5 cells. This was accompanied by significant accumulation of mitochondrial H₂O₂, SA, LPO, and PCC, along with increased transcriptional and enzymatic activities of TrxR2, SOD2, GPx1, and GR. Notably, the GSH/GSSG ratio was significantly reduced whereas NAD⁺/NADH and NADP⁺/NADPH ratios were significantly elevated. Metabolic exhaustion was also evident in senescent cells underscored by the severely diminished ATP/ADP ratio. Profound oxidative stress may contribute, at least in part, to senescence pointing at a potential protective role of antioxidants in aging-associated disease.

Lauric Acid, a Dietary Saturated Medium-Chain Fatty Acid, Elicits Calcium-Dependent Eryptosis

Cardiovascular diseases (CVD) are a leading cause of mortality worldwide, and dietary habits represent a major risk factor for dyslipidemia; a hallmark of CVD. Saturated fatty acids contribute to CVD by aggravating dyslipidemia, and, in particular, lauric acid (LA) raises circulating cholesterol levels. The role of red blood cells (RBCs) in CVD is increasingly being appreciated, and eryptosis has recently been identified as a novel mechanism in CVD. However, the effect of LA on RBC physiology has not been thoroughly investigated. RBCs were isolated from heparin-anticoagulated whole blood (WB) and exposed to 50-250 μM of LA for 24 h at 37 °C. Hemoglobin was photometrically examined as an indicator of hemolysis, whereas eryptosis was assessed by Annexin V-FITC for phosphatidylserine (PS) exposure, Fluo4/AM for Ca²⁺, light scatter for cellular morphology, H₂DCFDA for oxidative stress, and BODIPY 581/591 C11 for lipid peroxidation. WB was also examined for RBC, leukocyte, and platelet viability and indices. LA caused dose-responsive hemolysis, and Ca²⁺-dependent PS exposure, elevated erythrocyte sedimentation rate (ESR), cytosolic Ca²⁺ overload, cell shrinkage and granularity, oxidative stress, accumulation of lipid peroxides, and stimulation of casein kinase 1α (CK1α). In WB, LA disrupted leukocyte distribution with elevated neutrophil-lymphocyte ratio (NLR) due to selective toxicity to lymphocytes. In conclusion, this report provides the first evidence of the pro-eryptotic potential of LA and associated mechanisms, which informs dietary interventions aimed at CVD prevention and management.

The role of oxidative stress in patients with recurrent pregnancy loss: a review

BACKGROUND

Recurrent pregnancy loss (RPL) presents one of the main problems in the field of reproductive medicine, due to the unknown etiology in 50% of cases, as well as limited evidence-based diagnostic and therapeutic modalities. Recent studies indicate that systemic and placental oxidative stress (OS) represents an essential factor in the etiopathogenesis of RPL. This article is a comprehensive narrative synthesis of previously published studies concerning the role of oxidative stress in the etiology of recurrent pregnancy loss.

METHODS

We conducted literature search of published studies in the English language focusing on oxidative stress and its association with recurrent pregnancy loss (RPL) utilizing the Medline and Cochrane databases from 2000 through January 2021. The keywords used were "recurrent pregnancy loss" "oxidative stress and recurrent pregnancy loss" and "oxidative stress biomarkers and recurrent pregnancy loss".

RESULTS

The search yielded 1116 publications, of which 92 were included in the final analysis. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) at basal levels have various physiological functions whereas deviation from redox window is associated with different pathologies including early pregnancy loss. The currently available studies support the concept that increased oxidative stress (OS) and deficient antioxidant protection is implicated in the etiology of recurrent pregnancy loss (RPL) but underlying mechanisms through which OS affects pregnancy outcome remains largely indefinable.

CONCLUSIONS

Future research in this field can provide new insights regarding the OS-mediated damage in recurrent pregnancy loss as well as potential applications of antioxidant therapy in this group of patients.

Assessment of DNA damage in relation to heavy metal induced oxidative stress in females with recurrent pregnancy loss (RPL)

Pregnancy termination consecutively for three or more times during the first trimester is termed as Recurrent pregnancy loss (RPL). In addition to the abnormal karyotype, heavy metal induced oxidative damage may contribute as prominent etiological factor in pregnancy termination. Oxidative stress is considered crucial in etiology underlying RPL with altered antioxidant status and subsequent DNA damage. The current case controlled study investigated Total antioxidant capacity (TAC), DNA damage (8OHdG) and heavy metals in RPL group (n = 30) and the women with successful pregnancies and no cases of miscarriage as control group (30 women). Heavy metals -Antimony (Sb) and Arsenic (As) were measured by Inductively Coupled Plasma Mass spectrophotometry (ICP-MS). There was significant decrease in levels of TAC in RPL group compared to healthy pregnant women (P < 0.05). On contrary, elevated levels of As and Sb were observed in RPL group with subsequent increase in the levels of 8OHdG (P < 0.001); indicating extensive DNA damage in these patients. Furthermore, increased levels of As and Sb in RPL group were positively correlated with 8OHdG and negatively with total antioxidant capacity. The outcome of the study provides clear insight of the role of metal induced oxidative stress that plays a vital role in the pathophysiology underlying RPL.

Association of M55L and Q192R polymorphisms of paraoxonase 1 gene (PON1) with recurrent pregnancy loss risk: A case-control study

Background

Recurrent pregnancy loss (RPL) refers to the incidence of two or more abortions before the first half of pregnancy. Oxidative stress has been hypothesized to play a central role in RPL.

Objective

To investigate the relationship between Q192R and L55M polymorphisms of PON1 as antioxidant enzyme and the risk of RPL.

Materials and Methods

In this case–control study, 110 women with RPL (case) and 110 healthy fertile women (control) referred to the Research and Clinical Center for Infertility, Shiraz, Iran were enrolled. Genomic DNA was extracted from the peripheral blood in all participants. Polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism method.

Results

Statistical analysis of Q192R polymorphism showed a significant difference for the RR genotype between the case and control group (OR = 11, CI = 1.39–86.87, p = 0.005) but none for the QR and QQ genotypes. No significant association was observed between the R and Q allelic frequency in the RPL participants compared to the control group (p = 0.53). Also, statistical analysis of the L55M polymorphism for MM genotype in the case group compared with the control group showed a significant difference (OR = 3.59, CI = 0.97–13.30, p = 0.042), but none for the LM and LL genotypes.

Conclusion

The findings showed a significant correlation between the Q192R polymorphisms and the L55M PON1 enzyme and RPL in this study population.

Whole-Genome Sequencing Reveals Exonic Variation of ASIC5 Gene Results in Recurrent Pregnancy Loss

Family trio next-generation sequencing-based variant analysis was done to identify the genomic reason on unexplained recurrent pregnancy loss (RPL). A family (dead fetus and parents) from Saudi Arabia with an earlier history of three unexplained RPLs at the ninth week of pregnancy was included in the study. Whole-genome sequencing (WGS) of a dead fetus and the parents was done to identify the pathogenic variation and confirmed through Sanger sequencing. WGS of dead fetus identifies a novel homozygous exonic variation (NM_017419.3:c.680G>T) in ASIC5 (acid-sensing ion channel subunit family member 5) gene; the parents are heterozygous. Newly designed ARMS PCR followed by direct sequencing confirms the presence of heterozygous in one subject and absence of homozygous novel mutation among randomly selected healthy Saudis. The second family with heterozygous was confirmed with three unexplained RPLs. Pathogenicity analysis of R227I amino acid substitution in ASIC5 protein through molecular docking and interaction analysis revealed that the mutations are highly pathogenic, decrease the stability of the protein, and prevent binding of amiloride, which is an activator to open the acid-sensing ion channel of ASIC5. The identified rare and novel autosomal recessive mutation, c.680G>T:p.R227I (ASIC5Saudi), in two families confirm the ASIC5 gene association with RPL and can be fatal to the fetus.

Maternal selenium deficiency during gestation is positively associated with the risks for LBW and SGA newborns in a Chinese population

BACKGROUND

Maternal selenium (Se) deficiency is associated with some adverse pregnant outcomes. However, it remains controversial whether maternal Se deficiency during gestation enhances the risks for low-birth-weight (LBW) and small-for-gestational-age (SGA) newborns.

METHODS

For our cohort study, total 3133 mother-and-infant pairs were selected. Maternal serum Se concentration was detected by graphite furnace atomic absorption spectrometry. According to international references for maternal serum Se concentration, subjects were divided into Se deficiency (<45.0 μg/L), Se insufficiency (45.0-94.9 μg/L) and Se sufficiency (≥95.0 μg/L).

RESULTS

There was a positive relation of maternal serum Se concentration in gestation and neonatal birth weight. Further analysis showed that the risks for LBW and SGA in SD group were significantly higher than that in SI and SS group, the adjusted ORs for LBW and SGA newborns were 1.87 (95%CI: 1.02, 3.45; P = 0.04) and 1.47 (95%CI: 1.07, 2.02; P = 0.02) in SI group, and 3.92 (95%CI: 2.03, 7.57; P < 0.001) and 2.77 (95%CI: 1.92, 4.02; P < 0.001) in SD group compared to SS group. In different gender subgroup, positive relations were observed between maternal Se deficiency and the risk for LBW girls, as well as the risks for both SGA girls and boys.

CONCLUSION

Maternal Se deficiency in gestation was positively associated with the risk for LBW girls, as well as the risks for both SGA girls and boys.

Telomere Length in Idiopathic Recurrent Pregnancy Loss

OBJECTIVE

Telomere length is used as an indicator of biological aging. It is well known that one of the most remarkable risk factors of recurrent pregnancy losses is advanced maternal age. The objective of this study was to investigate the correlation between idiopathic recurrent pregnancy loss and telomere length.

METHOD

The study group included 40 women, while the control group consisted of 41 healthy women whose age and body mass index were matched. A venous blood sample was taken from all participants into EDTA tubes in the early follicular phase, and telomere length was measured through the qPCR technique.

RESULTS

When the mean TL of the groups was compared, it was determined that TL was significantly shorter among the iRPL group (7763.89±924.58 base pair) compared to the control group (8398.84±1102.95 base pair) (p<0.006). Whereas FSH and E2 were higher in the iRPL group, TAFC was lower (p<0.001). When the correlation between telomere length and endocrine parameters was statistically tested in the iRPL group, a negative correlation was found between FSH and telomere length (r=-0.437; p<0.001).

CONCLUSION

Shortened telomere length might play a role in the etiology of iRPL. We are of the opinion that patients with RPL should be screened for the presence of cardiovascular diseases and other chronic diseases, as is the case for POF.

The relationship between semen factors and unexplained recurrent spontaneous abortion

BACKGROUND

The male factor may contribute to unexplained recurrent spontaneous abortion (URSA). The relationship between semen factors and URSA is largely unknown. The analysis of metabolomics which is broadly acknowledged as the omics closest to the phenotype is suitable for providing assistance in the semen parameters analysis.

METHODS

We conducted a study including couples with URSA and controls which was next combined with a meta-analysis, and finally the study included 2352 subjects on semen parameters and URSA. Metabolomics analysis was conducted to detect semen metabolic factors related to URSA in total of 106 samples including seminal plasma and sperm cells.

RESULTS

The URSA group had significantly lower total sperm count, sperm concentration, motility and normal morphology percentage. Meta-analysis next showed consistent findings. Metabolomics revealed that 4 metabolites and one pathway and 8 metabolites and one pathway were significantly associated with URSA in sperm and seminal plasma, respectively. The combination of ascorbic acid and guanine in seminal plasma and hexadecanedioic acid and pyroglutamic acid in sperm showed ability for URSA prediction.

CONCLUSION

We provided novel insights into semen indices in relation to URSA. Lower sperm number and quality might increase the risk of URSA, and oxidative stress and hormone metabolism in sperm as well as nucleic acid synthesis and oxidative stress in seminal plasma were related to URSA.

Exposure to a high selenium environment in Punjab, India: Biomarkers and health conditions

Seleniferous areas have been identified and described in many parts of the world. Despite the interest in selenium as a trace element of considerable toxicologic and nutritional relevance, however, only a few studies have been carried out on human health effects of such high selenium environments. We collected blood, hair and nail samples from 680 adult volunteers (267 men and 413 women) living in seven villages located in the seleniferous area of Punjab, India. We measured selenium levels in these specimens. We also administered a questionnaire to collect information about diet and other lifestyle characteristics, to identify the sources of selenium exposure and to correlate it with a number of health conditions. Serum and hair selenium contents were highly correlated, while the association of these biomarkers with nail selenium content was weaker. Serum selenium showed limited association with consumption of locally produced foods, while pulses and vegetables, along with cereals and pulses, were associated to higher hair and nail selenium contents, respectively. Association of a number of adverse health endpoints with serum and hair selenium was stronger than for nail selenium contents. Such endpoints included higher prevalence of nausea and vomiting, bad breath, worm infestation, breathlessness exert and bad breath, chest pain, hair and nail abnormalities and loss, garlic odor, edema, spontaneous abortion, and overall selenosis. In contrast, we gathered no evidence of dermatitis or loss of appetite in residents most exposed to selenium. Overall, and despite some statistical imprecision in effect estimates, these results confirm the occurrence of adverse health effects in subjects exposed to high levels of environmental selenium. Nail selenium contents may be less adequate to reflect and monitor such overexposure, compared with blood and hair levels.

Mutations in the zebrafish hmgcs1 gene reveal a novel function for isoprenoids during red blood cell development

Erythropoiesis is the process by which new red blood cells (RBCs) are formed and defects in this process can lead to anemia or thalassemia. The GATA1 transcription factor is an established mediator of RBC development. However, the upstream mechanisms that regulate the expression of GATA1 are not completely characterized. Cholesterol is 1 potential upstream mediator of GATA1 expression because previously published studies suggest that defects in cholesterol synthesis disrupt RBC differentiation. Here we characterize RBC development in a zebrafish harboring a single missense mutation in the hmgcs1 gene (Vu57 allele). hmgcs1 encodes the first enzyme in the cholesterol synthesis pathway and mutation of hmgcs1 inhibits cholesterol synthesis. We analyzed the number of RBCs in hmgcs1 mutants and their wild-type siblings. Mutation of hmgcs1 resulted in a decrease in the number of mature RBCs, which coincides with reduced gata1a expression. We combined these experiments with pharmacological inhibition and confirmed that cholesterol and isoprenoid synthesis are essential for RBC differentiation, but that gata1a expression is isoprenoid dependent. Collectively, our results reveal 2 novel upstream regulators of RBC development and suggest that appropriate cholesterol homeostasis is critical for primitive erythropoiesis.

Effects of Selenium and Melatonin on Ocular Ischemic Syndrome

Purpose

To determine the effects of selenium, melatonin, and selenium + melatonin administered for one month on anterior chamber (AC) malondialdehyde (MDA) and AC glutathione (GSH) levels in patients with ocular ischemic syndrome.

Materials and Methods

Thirty-five patients were included in the study. Study groups were formed as follows: (1) control group, (2) ischemia group, (3) selenium + ischemia group, (4) melatonin + ischemia group, and (5) selenium + melatonin + ischemia group. AC samples were obtained. MDA and GSH levels in AC samples were evaluated.

Results

MDA levels were significantly increased in ischemia groups. Selenium and melatonin supplementation resulted in reduction of MDA levels and significant increase in GSH values.

Discussion

Increased lipid peroxidation associated with ischemia of the anterior segment has been prevented by selenium and melatonin supplementation. This trial is registered with ClinicalTrials.gov NCT04005222.

Molecular and biochemical investigations of key antioxidant/oxidant molecules in Saudi patients with recurrent miscarriage

The present study was undertaken to: i) Determine the levels of oxidative stress (OS) markers, malondialdehyde (MDA), superoxide anions (SOA) and hydrogen peroxide (H₂O₂), in both plasma and placental tissues of recurrent miscarriage (RM) patients in comparison with those of healthy pregnant (HP) and non-pregnant (NP) women; ii) determine the levels of enzymatic antioxidants [glutathione peroxidase (GPx), glutathione reductase (GSR), superoxide dismutase (SOD) and catalase (CAT)], and non-enzymatic antioxidant micronutrients [selenium (Se), zinc (Zn), copper (Cu) and manganese (Mn)] in both plasma and placental tissues of RM patients, in comparison with those of HP and NP women; iii) profile differential expression levels of selected antioxidant and apoptosis-related genes in the placental tissues of RM cases, in relation to those of HP women of matched gestational age, using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The results revealed highly significant increases of all investigated OS markers in plasma and placental tissues of RM patients compared with those of HP women. Moderate, but significant, increases of OS markers were observed in the plasma of HP patients in relation to those of NP women. The activities of antioxidant enzymes exhibited statistically significant decreases in both plasma and placental tissues of RM patients compared with those of HP women. The significantly reduced level of antioxidant enzymes was also evident in the plasma of HP women as compared with those of NP women. Results of RT-qPCR assays clearly indicated that the expression level of apoptosis-related genes [tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and S100A8], and pro-inflammatory cytokine genes [tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-8] were significantly upregulated in placental tissue of RM cases in relation to those of HP subjects. By contrast, mRNA transcriptional levels of key antioxidant genes (GPx, SOD, GSR and CAT) were found to be significantly reduced in placental tissue of RM patients in comparison to those of HP women. In conclusion, our data highlight a plausible cause-effect association between the observed increase in placental OS level and depletion of the activity of antioxidant enzymes. This suggests that OS is a contributing factor in the pathogenesis of idiopathic RM.

Selenium and Health: An Update on the Situation in the Middle East and North Africa

Selenium (Se) is an important trace element that should be present in the diet of all age groups to provide an adequate intake. Se is incorporated in 25 known selenoproteins, which mediate the biological effects of Se including, immune response regulation, maintenance of thyroid function, antioxidant defense, and anti-inflammatory actions. A balanced intake of Se is critical to achieve health benefits because depending on its status, Se has been found to play physiological roles or contribute to the pathophysiology of various diseases including, neurodegenerative diseases, diabetes, cancer, and cardiovascular disorders. Se status and intake are very important to be known for a specific population as the levels of Se are highly variable among different populations and regions. In the Middle East and North African (MENA) region, very little is known about the status of Se. Studies available show that Se status is widely variable with some countries being deficient, some over sufficient, and some sufficient. This variability was apparent even within the same country between regions. In this review, we summarized the key roles of Se in health and disease and discussed the available data on Se status and intake among countries of the MENA region.

Evaluation of oxidative stress and δ-aminolevulinate dehydratase activity in twin pregnancies

Purpose: To assess and understand the maternal oxidative stress in twin pregnancies, currently not studied, through ascertain indicators of oxidative damage in maternal blood in response of two fetuses, as well as the relation of placenta with or without the increase of oxidative stress in these gestations.Materials and methods: The activity of delta-aminolevulinate dehydratase (δ-ALA-D) was analyzed as an indirect marker of oxidative stress, as well as the quantification of thiobarbituric acid reactive substances (TBARS), protein thiol groups (P-SH) and nonprotein thiol groups (NP-SH), vitamin C (VIT C) and catalase activity (CAT) in maternal blood samples from twin (n = 30) and single (n = 30) pregnancies. This study was approved by the Human Ethics Committee UFSM (register by the number 49823015.4.0000.5346).Results: TBARS was significantly higher in twin pregnancies, while thiol groups, VIT C and CAT were decreased, asides from the reduced activity of δ-ALA-D in comparison to single fetus gestations.Conclusions: The study established an oxidative stress increased and an antioxidant ability decreased in twin pregnancies, suggesting a possible relation between the levels of oxidants and antioxidants with the complications in those gestations.

Longitudinal Study of Delta-Aminolevulinate Dehydratase Activity and Oxidative Profile in Healthy Pregnant Women

Pregnancy is characterized by changes in various organs, triggering changes in the use of energy substrates and increased oxygen consumption. In addition, gestation is an oxidative event that can be assessed by the relationship between free radicals and antioxidants produced by the body. Excessive production of free radicals has detrimental effects such as damage to enzymes, carbohydrates, and DNA. Thus, the objective of this study was to evaluate the oxidative status and antioxidant responses throughout pregnancy through a longitudinal study. Reactive oxygen species were analyzed by means of thiobarbituric acid reactive substances and nitric oxide, the antioxidant system through vitamin C, sulfhydryl groups, total antioxidant capacity, and ferric reducing ability of plasma as well as enzymes such as catalase and delta-aminolevulinate-dehydratase in pregnant women in the three gestational trimesters (n = 30). According to the results, the markers of oxidative damage showed significant differences in the different gestational trimesters where they were increased in the second trimester when compared to the first trimester. The antioxidant defenses responded differently in each gestational trimester, suggesting a response pattern to try to combat the damage caused by free radicals, in order to stabilize the increase of oxidative stress caused in the second gestational trimester.

Selenium in Complicated Pregnancy. A Review

Selenium (Se) is an essential trace element of significant importance in human health. Diet is the major source of Se, and intake of this element depends on its concentration in food sources as well as the amount of those sources consumed. Unfortunately, daily dietary intake of Se in most European countries is generally low, ∼30-40μg/day, compared with the recommended dietary allowance, ∼55 and 70μg/day for adult females and males, respectively. The importance of Se as an essential trace element is linked to its role as selenocysteine in a number of selenoproteins including antioxidant enzymes glutathione peroxidases (GSH-Pxs), thioredoxin reductases (TrxRs), and selenoprotein P (SePP). These enzymes protect tissues against the damaging effect of reactive oxygen species (ROS) and other endogenous products of cellular metabolism implicated in DNA damage and potentially leading to mutagenesis, cell death, and carcinogenesis. Reduced body Se and antioxidant enzyme activity during pregnancy results in oxidative stress within tissues contributing to premature birth, miscarriage, preeclampsia, and intrauterine growth retardation. Because placenta development is highly dependent on oxygen status, uncontrolled ROS formation is likely detrimental. Despite these findings, the role of Se and Se-dependent enzymes in pregnancy remains controversial. The objective of this review is to explore Se status in pregnancy with respect to adverse outcomes. Effects related to decreased antioxidant activity and increased oxidative stress will be highlighted.

Pleiotropic roles of melatonin in endometriosis, recurrent spontaneous abortion, and polycystic ovary syndrome

Melatonin is a neurohormone synthesized from the aromatic amino acid tryptophan mainly by the pineal gland of mammals. Melatonin acts as a broad-spectrum antioxidant, powerful free radical scavenger, anti-inflammatory agent, anticarcinogenic factor, sleep inducer and regulator of the circadian rhythm, and potential immunoregulator. Melatonin and reproductive system are interrelated under both physiological and pathological conditions. Oxidative stress, inflammation, and immune dysregulation are associated with the pathogenesis of the female reproductive system which causes endometriosis (EMS), recurrent spontaneous abortion (RSA), and polycystic ovary syndrome (PCOS). Accumulating studies have indicated that melatonin plays pleiotropic and essential roles in these obstetrical and gynecological disorders and would be a candidate therapeutic drug to regulate inflammation and immune function and protect special cells or organs. Here, we systematically review the pleiotropic roles of melatonin in EMS, RSA, and PCOS to explore its pathological implications and treatment potential.

Selenium Concentrations for Maximisation of Thioredoxin Reductase 2 Activity and Upregulation of Its Gene Transcripts in Senescent Human Fibroblasts

Thioredoxin reductase 2 (TR2) activity, its gene transcripts, and hydrogen peroxide (H₂O₂) generation were examined in biochemically identified early-senescent P20 and senescent P30 fibroblasts subcultured in media (MEM2–MEM8) containing Se concentrations at 1.25, 2.5, 3.5, 5.0, 6.0, 7.0, and 8.0 µM, respectively. Although TR2 activity was moderately increased in P20 and P30 cells subcultured in routine growth medium (MEM1), there were progressive significant activity increases in the same cells subcultured in MEM2–MEM8. Such increases were proportional to Se concentration and peaked in P30 cells incubated with MEM7 and MEM8. H₂O₂ generation underwent progressive increases in MEM1-incubated P20 and P30 cells, peaking in the latter, but was gradually lowered in those incubated with MEM2–MEM8, reaching its lowest values when cells were incubated with MEM7 and MEM8. In parallel, TR2 gene transcripts underwent significant upregulation in P20 cells and higher magnitude upregulation in P30 cells subcultured in MEM2, MEM4, and MEM8 compared to those recorded for P5 pre-senescent cells subcultured in the same media. The computed Km Se values with respect to TR2 activity equaled 3.34 and 4.98 µM for P20 and P30 cells, respectively, with corresponding V_max activities of 55.9 and 96.2 nmol/min/mg protein. It is concluded that senescent P30 cells utilize more Se and achieve maximal TR2 activity to combat oxidative injury.

Ascorbate ameliorates Echis coloratus venom-induced oxidative stress in human fibroblasts

Reports related to the effects of Echis coloratus venom (EcV) on the antioxidant capacity of human tissues is very scarce. The present study was undertaken to investigate the activities and gene expression levels of glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT), as well as the levels of reduced glutathione (GSH), oxidized glutathione (GSSG) and the generation rates of superoxide anions (SOA), hydrogen peroxide (H₂O₂) and lipid peroxides (LPO) in cultured human fibroblasts incubated with EcV, ascorbate (Asc) and EcV plus Asc at concentrations and incubation periods that maintained cell viability. Results indicated that the activities of all antioxidant enzymes and their corresponding transcripts underwent highly significant decreases and downregulation in EcV-treated cultures (0.5 µg/ml medium for 4 h) compared to venom-free controls (P<0.001). Additionally, there were concurrent equally significant increases in SOA, H₂O₂ and LPO generation rates in the venom-incubated cultures compared to controls (P<0.001). Results also indicated very significant decreases and parallel equally significant increases in GSH and GSSG levels respectively in the envenomed cultures compared to controls (P<0.001) leading to a drastically lower GSH/GSSG ratio. However, further incubation of the EcV-treated cultures with Asc (400 µM for 12 h) restored the activities and levels of all investigated parameters including the expression levels of the antioxidant genes to control venom-free values. It is concluded that Asc acted to neutralize the increased reactive oxygen species generation, thus ameliorating the EcV-induced oxidative stress and alleviating the downregulation of antioxidant genes.

OLR1 and Loxin Expression in PBMCs of Women with a History of Unexplained Recurrent Miscarriage: A Pilot Study

AIMS

The aim of this study was to evaluate the expression of OLR1 and its alternative splicing isoform Loxin in unexplained recurrent miscarriage (uRM).

METHODS

Sixty-three women of reproductive age were recruited and were divided into four groups: 18 pregnant and 23 non-pregnant women with uRM, and 12 pregnant and 10 non-pregnant women with physiological pregnancies. Complementary DNA derived from peripheral blood mononuclear cells (PBMCs) was analyzed by quantitative real-time PCR to evaluate the expression of OLR1 and Loxin. Oxidized low-density lipoproteins (ox-LDLs) were assayed from serum by a commercially available kit.

RESULTS

Pregnant uRM women presented with a higher, though not significant, OLR1/Loxin ratio and a higher ox-LDLs serum level (p ≤ 0.05) compared with pregnant control women. OLR1 and Loxin levels were significantly decreased in non-pregnant uRM women compared with the control (OLR1: 0.00018 vs. 0.00043, p ≤ 0.005; Loxin: 0.00018 vs. 0.00060, p ≤ 0.005, respectively). Loxin expression decreased by about two-thirds (p ≤ 0.005) in pregnant women compared with non-pregnant control women. A higher expression of OLR1 in pregnant women compared with non-pregnant women with uRM (p ≤ 0.05) was observed, but no variation in Loxin expression was observed.

CONCLUSIONS

The results of this study show an association of peripheral OLR1 and Loxin expression levels in uRM women, and they suggest the possible existence of an uncontrolled oxidative stress in these women in the first trimester of pregnancy.

The effect of Echis coloratus venom on biochemical and molecular markers of the antioxidant capacity in human fibroblasts

This study was undertaken to examine the activities and levels of major antioxidants/oxidants in cultured human fibroblasts incubated with a sublethal dose of Echis coloratus venom (EcV).

Glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR) activities and gene expression levels as well as reduced glutathione (GSH) levels, and the concurrent hydrogen peroxide (H₂O₂), superoxide anions (SOA), lipid peroxides (LPO) and oxidized glutathione (GSSG) generation rates were assayed in fibroblast cultures and sonicates incubated with 0.5 µg ml^–1 medium EcV for 4 h at 37°C.

Data indicated that the activities of all antioxidant enzymes were significantly decreased and their corresponding transcripts downregulated in EcV-incubated cells compared to controls (p < 0.001). In contrast, there were parallel equally significant increases in H₂O_2, SOA and LPO generation rates in venom-incubated cells compared to controls (p < 0.001). Additionally, GSH levels were significantly decreased and those of GSSG were equally significantly increased in venom-incubated cultures compared to controls (p < 0.001) leading to a lowered GSH/GSSG ratio.

In conclusion, incubation of fibroblast cultures with EcV resulted in a shift towards oxidative metabolism causing severe OS. This correlated with significant downregulation in the expression levels of all investigated antioxidant genes.

Superoxide dismutase activity and gene expression levels in Saudi women with recurrent miscarriage

The antioxidant activities of superoxide dismutase 1 (SOD1) and SOD2, as well as the levels of the oxidant superoxide anion (SOA) and the micronutrients zinc (Zn), copper (Cu) and manganese (Mn), were assayed in plasma, whole blood and placental tissue of non-pregnant (NP), healthy pregnant (HP) women and recurrent miscarriage (RM) patients. The results showed that SOD1 and SOD2 activities and the levels of Zn, Cu and Mn in plasma and whole blood of HP women were slightly, but significantly lower, and even more significantly decreased in RM patients compared to those observed in NP women (P<0.05 and P<0.0001, respectively). Additionally, whereas plasma SOD1 and SOD2 activities and Zn, Cu and Mn levels were significantly lower in RM patients, those of whole blood and placental tissue were significantly lower when compared to HP women (P<0.001 and P<0.0001, respectively). Concurrently, there were consistent increases of equal magnitude and statistical significance in SOA levels in all the assayed samples as identified by a comparison between the subjects. The findings thus supported oxidative metabolism and excessive reactive oxygen species generation. The resultant oxidative stress, identified in whole blood and placental tissues of RM patients, may have been a primary cause of RM. Dietary supplementation of Zn, Cu and Mn may be beneficial to these patients pre- and post-conception.