Peripheral Polymorphonuclear Leukocyte Priming Contributes to Oxidative Stress in Early Pregnancy

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.

Low molecular weight heparin treatment reduced apoptosis and oxidative cytotoxicity in the thrombocytes of patients with recurrent pregnancy loss and thrombophilia: Involvements of TRPM2 and TRPV1 channels

AIM

Recurrent pregnancy loss (RPL) is known to be associated with increased thrombophilia and oxidative toxicity. However, the mechanism of thrombophilia apoptosis and oxidative toxicity is still unclear. In addition, the treatment of heparin induced regulator roles on intracellular free Ca²⁺ ([Ca²⁺ ]_i ) and cytosolic reactive oxygen species (cytROS) concentrations in several diseases. TRPM2 and TRPV1 channels are activated by different stimuli, including oxidative toxicity. The aim of this study was to investigate the effects of low molecular weight heparin (LMWH) via modulation of TRPM2 and TRPV1 on calcium signaling, oxidative toxicity, and apoptosis in the thrombocytes of RPL patients.

STUDY DESIGN

Thrombocyte and plasma samples collected from 10 patients with RPL and 10 healthy controls were used in the current study.

MAIN FINDINGS

The [Ca²⁺ ]_i concentration, cytROS (DCFH-DA), mitochondrial membrane potential (JC-1), apoptosis, caspase-3, and caspase-9 levels were high in the plasma and thrombocytes of RPL patients, although they were diminished by the treatments of LMWH, TRPM2 (N-(p-amylcinnamoyl)anthranilic acid) and TRPV1 (capsazepine) channel blockers.

CONCLUSIONS

The current study results suggest that the treatment of LMWH is useful against apoptotic cell death and oxidative toxicity in the thrombocytes of patients with RPL, which seem to be dependent on increased levels of [Ca²⁺ ]_i concentration via the activation of TRPM2 and TRPV1.

Dynamic thiol/disulphide homeostasis and ischemic modified albumin levels in isolated oligohydramnios

OBJECTIVE

Oligohydramnios is defined as amniotic fluid index in ultrasonographic measurement is less than 5 percentile according to gestational age, the amniotic fluid volume is ≤ 5 cm, or if the single deepest dial is < 2 cm. The condition of oligohydramnios that not with fetal structural/chromosomal abnormalities, intrauterine growth retardation, intrauterine infection and maternal disease is described as isolated oligohydramnios (IO). The aim of this study is to examine whether oxidative stress and reactive oxygen species (ROS) have a place in the pathophysiology of IO.

MATERIALS AND METHODS

In this prospective case-control study, a total of 126 participants were included. The patient group consisted of 65 patients who were diagnosed IO, and the control group consisted of 61 healthy normal pregnants. Native thiol (-SH), total thiol (-SH + -SS), dynamic disulfide (-SS), IMA values from maternal serum were measured and compared between groups.

RESULTS

Maternal serum -SH and -SH + -SS values were significantly lower in the IO group than in the control group (409.47 ± 55.36 μmol/L vs. 437.40 ± 48.68 μmol/L, p = 0.03 and 457.40 ± 63.01 μmol/L vs. 484.59 ± 52.75 μmol/L, p = 0.01). In the IO group when -SS/-SH and -SS/-SH + -SS ratio was found to be statistically significantly higher than control group (5.84 ± 1.1 vs 5.41 ± 0.71, p = 0.01 and 5.2 ± 0.88 vs 4.8 ± 0.58, p = 0.01), -SH/-SH + -SS ratio was significantly lower (89.56 ± 1.7 vs 90.24 ± 1.16, p = 0.01). There was no significant difference in terms of -SS value (p = 0.66). IMA value was significantly higher in the IO group than control group (0.76 ± 0.10 ABSU vs 0.68 ± 0.06, p < 0.01). It is seen as a result of ROC analysis that -SH, -SH + -SS, -SS/-SH, -SS/-SH + -SS, -SH/-SH + -SS and IMA values have a diagnostic value for IO (p < 0.05).

CONCLUSION

The thiol/disulfide balance shifted towards oxidative stress in IO compared to control group. So oxidative stress and ROS have a place in the pathophysiology of IO.

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.

Does ischaemia-modified albumin level predict clomiphene citrate resistant polycystic ovary syndrome patients?

This study aims to examine the role of ischaemic-modified albumin (IMA) in predicting clomiphene citrate (CC) resistance in patients with CC-resistant and CC-sensitive infertile polycystic ovary syndrome (PCOS). Sixty women patients admitted to the infertility clinic were evaluated. The patients were divided into two groups. Group 1 comprised 30 infertile PCOS patients with CC resistance; group 2 was the control group comprising 30 infertile PCOS patients with CC sensitivity. Serum IMA levels of PCOS patients with CC resistance were significantly higher than CC sensitivity patients (p < .001). The independent variables BMI and age effects were adjusted according to the logistic regression method with groups. Significant differences were observed between the two groups in the levels of IMA (p = .0005), HOMA-IR (p = .0045), insulin (p = .022), free testosterone (p = .0001) and total testosterone (p = .03) values. By using ROC curve analysis for IMA between study and control groups, cut off point of IMA was calculated as 0.505 U/mL, sensitivity was 80% and specificity was 63%. The area under the curve was 0.926. This shows us that more oxidative stress (OS) occurs in the CC-resistant group. As a reflection of OS in the follicular endocrine, microenvironment may be linked with impaired oocyte developmental competence and embryo quality in association with increased IMA, free testosterone, total testosterone, insulin and HOMA-IR levels.Impact statementWhat is already known on this subject? In previous studies, IMA was compared between PCOS and control groups. In this study, serum IMA levels were measured in infertile PCOS patients resistant to CC for the first time.What the results of this study add? Serum IMA levels were significantly higher in resistant infertile PCOS patients compared to the control group. This shows us that more OS occurs in the CC-resistant group.What the implications are of these findings for clinical practice and/or further research? IMA will be a guide for PCOS management in patients with CC-resistant PCOS.

Increased oxidative stress is associated with thiol/disulphide homeostasis in clomiphene citrate resistant polycystic ovary syndrome

The purpose of this study was to evaluate the relation CC resistant PCOS and the thiol/disulphide homeostasis, used as a marker of OS, by measuring that exchange using a novel technique. Sixty women patients admitted to the infertility clinic were evaluated. The patients were divided into two groups. Group 1 comprised 30 infertile PCOS patients with CC resistance; Group 2 was the control group comprising 30 infertile PCOS patients with CC sensitivity. Serum total thiol (p = .024), native thiol (p = .0052), disulphide (p = .003), index 1 (p = .001), index 2 (p = .001) and index 3 (p = .001), HOMA-IR (p < .001) and free testosterone (p < .001) were statistically significant. The independent variables BMI and age effects were adjusted according to the logistic regression method with groups. Significant differences were observed between the two groups in the levels of native thiol (p* = .0042), total thiol (p* = .024), disulphide (p* = .0003), index 1 (p* = .0001) index 2 (p*= .0001), index 3 (p* = .0001), HOMA-IR (p* = .0044), insulin (p*= .032) and free testosterone (p* = .0001) values. The thiol/disulphide homeostasis viewed in favour of OS. Like a reflection of OS in the follicular endocrine microenvironment may be linked with increased thiol/disulphide homeostasis, free testosterone, insulin and HOMA-IR levels.Impact statementWhat is already known about this subject? In previous studies, thiol/disulphide homeostasis was compared between PCOS and control groups. In this study, serum thiol/disulphide homeostasis was measured in infertile PCOS patients resistant to CC for the first time.What do the results of this study add? Disulphide concentrations were significantly higher in patients with CC resistant patients thanthe control group. This shows us that more OS occurs in the CC-resistant group.What are the implications of these findings for clinical practice and further research? Thiol/disulphide homeostasis will be a guide for PCOS management in patients with CC-resistant PCOS.

Maternal serum thiol/disulfide homeostasis in pregnancies complicated by fetal hypoxia

We aimed to evaluate maternal serum thiol/disulphide homeostasis in pregnancies complicated by fetal distress (FD). A total of 100 patients beyond the 34th week of pregnancy were included in this study, and they were divided into two groups. The study group included 50 patients who had been diagnosed with FD; the control group was composed of 50 patients who had shown no signs of FD and who had undergone an elective (previous) caesarean section (CS). The native thiol, total thiol and native thiol/total thiol (%) concentrations were lower in Group 1 patients than Group 2 patients (p < .001). The disulphide, disulphide/native thiol (%) and disulphide/total thiol (%) concentrations were higher in Group 1 patients than Group 2 patients (p < .001). This study suggests that maternal thiol/disulphide homeostasis is impaired in pregnancies complicated by FD.IMPACT STATEMENTWhat is already known about this subject? Oxidative stress (OS) has previously been investigated in FD. This study reports for the first time a new novel and automatic measurement method.What do the results of this study add? This study shows that the thiol balance shifts in the direction of disulphide in the cases of FD.What are the implications of these findings for clinical practice and further research? Thiol balance can be used for the timely diagnosis of FD.

Low transcriptional activity of PON2 in recurrent abortion: A novel therapeutic agent?

OBJECTIVE

Oxidative stress has been reported to be associated with various pregnancy complications and to play key roles in many of them. An inadequate level of antioxidant defense may eventually lead to an early pregnancy loss. There is a lack of information about the roles of the PON2 and PON3 enzymes in the etiology of the cases of unexplained recurrent abortus. The aim of our study is to determine and present the data regarding the roles of these enzymes for the first time.

MATERIALS AND METHODS

We measured the transcriptional levels of the PON2 and PON3 enzymes in the curettage materials obtained from the patients with unexplained recurrent abortus (n=25) and compared the results with those measured in the abortus materials from healthy pregnant women (n=50) who had undergone a voluntary abortion. The transcriptional activities of PON2 and PON3 enzymes were measured through quantification of their respective mRNAs by RT-qPCR assay. For each gene, 2^-ΔCt replication values of the control and the patient groups were compared using the Student's t-test, and the p values were calculated thereafter. Fold-changes in the enzyme transcription levels were interpreted as up- or down-regulation.

RESULTS

PON2 mRNA expressions were found to be highly decreased in the patient group (p=0.000002). PON3 transcription, when compared to the healthy pregnant women, was found to be down-regulated in the patient group; however, the difference was not statistically significant (p=0.69).

CONCLUSIONS

In this study, we evaluated the expressional regulation of the PON2 and PON3 enzymes in unexplained recurrent abortus. Our results demonstrate for the first time that the expressions of PON2 and PON3 are down-regulated in the abortion specimens of the patients with recurrent miscarriage. Although both enzymes had low expression levels, the decrease in the transcriptional activity of PON2 revealed a high statistical significance. According to these results, it is rational to speculate that PON2 may be a novel therapeutic agent in the management of the cases with unexplained recurrent abortion.

Effect of Coenzyme Q10 on Th1/Th2 Paradigm in Females with Idiopathic Recurrent Pregnancy Loss

PROBLEM

Recurrent pregnancy loss is characterized by predominant Th1-type immunity and increased reactive oxygen species. Low levels of Coenzyme Q10 are found in the plasma of RPL as compared to healthy pregnant females. Our aim was to investigate whether in vitro supplementation of PBMCs from such females with CoQ10 could change the observed Th1 bias.

METHOD OF STUDY

PBMCs were isolated from 20 RPL pregnant and non-pregnant females and 16 healthy pregnant females and incubated with CoQ10 in in vitro conditions. Phenotyping of Th1, Th2, and Th17 cells was performed by flow cytometry. Cytokine levels were determined by ELISA.

RESULTS

PBMCs treated with CoQ10 showed significantly decreased percentage of Th1 cells (P < 0.005) in pregnant females with history of RPL than in the untreated ones. Also, levels of IFN-γ and TNF-α were significantly decreased in the culture supernatant of treated PBMCs from RPL. DCFDA staining showed significantly reduced production of ROS in the treated PBMCs in RPL females.

CONCLUSION

CoQ10 was effective in maintaining the immune homeostasis by reducing the proportion of IFN-γ-producing T cells and proinflammatory cytokine levels in the RPL pregnant females. This property could be attributed to the capability of CoQ10 in reducing oxidative stress by decreasing ROS production.

The oxidative stress index increases among patients with hyperemesis gravidarum but not in normal pregnancies

OBJECTIVE

The etiology and pathogenesis of hyperemesis gravidarum (HG) is still undetermined and has been suggested to involve oxidative stress. We aimed to evaluate the status of oxidative stress in HG by measuring the levels of total oxidant status (TOS), total antioxidant status (TAS), and by calculating the oxidative stress index (OSI).

METHODS

In a case-control trial, fasting morning blood samples of patients with HG (n = 41) and healthy pregnant women (n = 39) were collected for analysis of serum TOS and TAS values as well as for calculation of OSI according to the formula: OSI = TOS / TAS × 100.

RESULTS

Serum TOS and TAS levels were similar in both groups. However, serum TAS levels were lower among HG patients compared to controls, which resulted in an increase in OSI (P = 0.025).

DISCUSSION

The present study supports the role of systemic oxidative stress, reflected by an imbalance between the TOS and TAS, in patients with HG. Our findings distinguish the mechanism underlying oxidative stress to result from reduction of antioxidants rather than an increase in oxidants.

The role of oxidative stress in spontaneous abortion and recurrent pregnancy loss: a systematic review

Human reproduction is not considered a highly efficient biological process. Before the end of the first trimester, 30%-50% of conceptions end in spontaneous abortion. Most losses occur at the time of implantation. 15%-20% of clinical pregnancies end in spontaneous abortions. Recurrent pregnancy loss is a frustrating clinical problem both for clinicians and patients. Recurrent pregnancy loss affects 0.5%-3% of women in the reproductive age group, and between 50%-60% of recurrent pregnancy losses are idiopathic. Oxidative stress-induced damage has been hypothesized to play a role in spontaneous abortion, idiopathic recurrent pregnancy loss, hydatidiform mole, defective embryogenesis, and drug-induced teratogenicity. Some studies implicate systemic and placental oxidative stress in the pathophysiology of abortion and recurrent pregnancy loss. Oxidant-induced endothelial damage, impaired placental vascularization and immune malfunction have all been proposed to play a role in the pathophysiology of idiopathic recurrent pregnancy loss. Oxidative stress-induced placental dysfunction may be a common cause of the multifactorial and polygenic etiologies of abortion, recurrent pregnancy loss, defective embryogenesis, hydatidiform mole, and drug-induced teratogenic effects. Oxidative stress-induced modification of phospholipids has been linked to the formation of antiphospholipid antibodies in the antiphospholipid syndrome. The objective of this review was to examine the association between oxidative stress, spontaneous abortion and recurrent pregnancy loss, based on the published literature. We conducted an extensive literature search utilizing the databases of Medline, CINAHL, and Cochrane from 1986 to 2005. The following keywords were used: oxidative stress, abortion, recurrent pregnancy loss, reactive oxygen species, antioxidants, fetal development, and embryopathies. We conducted an electronic search, as well as a manual search of cross-references. We have included all studies in the English language found in the literature focusing on oxidative stress and its association with abortions, recurrent pregnancy loss and drug-induced teratogenicity. The role of antioxidant vitamins for primary prevention of oxidative stress-induced pathologies needs to be investigated further.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to state that the causes of spontaneous and recurrent abortion are multifaceted, however, some of the causes may be preventable and also explain that the role of oxidative stress during pregnancy and adverse pregnancy outcomes has a basis in pathophysiology, although the role of oxidative stress and the treatment of oxidative stress during or before pregnancy remains speculative.

Application of intracellular alkaline phosphatase activity measurement in detection of neutrophil adherence in vitro

We have proposed the use of the fluorimetric method with 4-methylumbelliferyl phosphate (4-MUP) specific substrate for the alkaline phosphatase determination in the neutrophil adhesion assay. We provide evidence that the endogenous neutrophil alkaline phosphatase (NAP) activity evaluation is reliable to quantify neutrophil adhesion at a wide range of cell numbers (10(4)-10(6)). The results obtained by fluorimetric NAP activity test correlate to the results of adherence evaluated using the MTT reduction assay. The fluorimetric NAP activity test may be applied for resting as well as activated neutrophils without the risk of the activators interferences into the test. The alkaline phosphatase survey with the use of 4-MUP substrate is recommended herein as a sensitive, repeatable, simple, and reliable method of the neutrophil adherence determination in vitro.

The role of free radicals and antioxidants in reproduction

PURPOSE OF REVIEW

This review summarizes the role of free radicals and oxidative stress in the pathophysiology of human reproduction.

RECENT FINDINGS

An extensive review of the literature on the role of oxidative stress in influencing assisted reproduction and its outcome is described in this article. Free radicals or reactive oxygen species mediate their action through many of the proinflammatory cytokines and this mechanism has been proposed as a common underlying factor for endometriosis, ovarian cancer, polycystic ovary disease, and various other pathologies affecting the female reproductive process, as highlighted in this review. Oxidative stress, sperm DNA damage, and apoptosis have been implicated in male infertility. Elevated reactive oxygen species levels correlate with the poor fertility outcomes seen in the assisted reproductive technology setting.

SUMMARY

Oxidative stress has been implicated in male and female infertility, including fetal dysmorphogenesis, abortions, and intrauterine growth restriction. Accurate evaluation of seminal oxidative stress by standardized assays may help in the diagnosis and management of male infertility. There is evidence in the literature on the beneficial effects of oral antioxidant supplementation in male infertility. Current ongoing trials will provide answers on the safety and effectiveness of antioxidants in improving maternal and fetal outcomes. Further studies need to be conducted to determine if antioxidant supplementation will prevent fetal developmental defects in high-risk pregnancy with diabetes.

Trophoblast contact deactivates human neutrophils

Trophoblasts are fetal epithelial cells that form an interface between mother and offspring. To evaluate their anti-inflammatory capacity, we tested the hypothesis that trophoblasts deactivate neutrophils using single-cell assays. Several biophysical (Ca2+ and NAD(P)H oscillation frequency) and physiological (oxidant production) markers of activated neutrophils revert to a nonactivated phenotype as activated cells make contact with trophoblasts. Indistinguishable results were obtained using syncytiotrophoblasts and in experiments using trophoblasts and neutrophils from the same mother to recapitulate the semiallogeneic system. These changes suggest reduced hexose monophosphate shunt (HMS) activity. We discovered that two metabolic regulatory points, glucose transport and HMS enzyme trafficking, are affected by trophoblasts. This restriction in HMS activity deactivates neutrophils, thereby limiting oxidative DNA damage within trophoblasts.