Increased oxidative stress in the placenta tissue and cell culture of tumour-bearing pregnant rats

Comprehensive morphological study of free radical processes in chronic chorioamnionitis on the background of iron deficiency anemia in pregnancy

OBJECTIVE

Aim: To establish the features of free radical processes in the endotheliocytes of the chorionic plate of the placenta in chronic chorioamnionitis against the background of iron deficiency anemia of pregnant women using both chemiluminescent and histochemical methods of research.

PATIENTS AND METHODS

Materials and Methods: 82 placentas from parturients at 37 - 40 weeks of gestation were studied. Including, for comparison, the placenta during physiological pregnancy and the observation of iron deficiency anemia of pregnant women without inflammation of the placenta. The number of observations in specific study groups is given in the tables. To achieve the objective and solve the tasks set in this study, there were carried out the following histochemical, chemiluminescent, morphometric and statistical methods of material processing.

RESULTS

Results: In case of chorionamnionitis against the background of anemia in pregnancy, the R/B ratio (R/B - ratio between amino- (blue) and carboxyl (red) groups of proteins)) in the method with bromophenol blue according to Mikel Calvo was 1.56±0.021, indicators of chemiluminescence of nitroperoxides were 133±4.5, relative optical density units of histochemical staining using the method according to A. Yasuma and T. Ichikawa was - 0.224±0.0015.

CONCLUSION

Conclusions: With chronic chorioamnionitis, the intensity of the glow of nitroperoxides, the average indicators of the R/B ratio, and the optical density of histochemical staining for free amino groups of proteins are increased compared to placentas of physiological pregnancy and anemia of pregnant women. Comorbid i anemia of pregnant women causes increasing of the intensity of the glow of nitroperoxides, the average values of the R/B ratio, and the optical density of histochemical staining for free amino groups of proteins comparing to placentas with inflammation without anemia. The key factor in the formation of morphological features of chronic chorioamnionitis with comorbid anemia is the intensification of free radical processes, which is reflected by the increase in the concentration of nitroperoxides in the center of inflammation, with the subsequent intensification of the processes of oxidative modification of proteins, which is followed by the increasing activity of the processes of limited proteolysis.

Maternal-placental axis and its impact on fetal outcomes, metabolism, and development

Maternal obesity could impact offspring's health. During "critical period" such as pregnancy insults have a significant role in developing chronic diseases later in life. Literature has shown that diet can play a major role in essential metabolic and development processes on fetal outcomes. Moreover, the placenta, an essential organ developed in pregnancy, seems to have its functions impaired based on pre-gestational and gestational nutritional status. Specifically, a high-fat diet has been shown as a potential nutritional insult that also affects the maternal-placental axis, which is involved in offspring development and outcome. Moreover, some classes of nutrients are associated with pregnancy complications such as reduced intake of micronutrients and diabetes, preeclampsia, and preterm delivery. Thus, we will summarize the current literature on maternal environment factors that impacts the placental development and consequently the fetal an offspring health, or the maternal-placental axis, and this on fetal outcomes, metabolism, and development.

Experimental evidence of the neurotoxic effect of monosodium glutamate in adult female Sprague Dawley rats: The potential protective role of Zingiber officinale Rosc. rhizomes

Strategies to prevent the health abnormalities associated with the extensive use of MSG (monosodium glutamate) as a flavoring booster are badly needed. The current study was conducted to investigate oxidative stress, inflammation, and abnormal lipid profile as the main risk factors of neurotoxicity in MSG-exposed female albino rats. Besides, the effect of concurrent consumption of Zingiber officinale rhizomes powder was studied at low doses. Twenty rats (total) were split into 4 separate groups. The 1st group was a negative control group (without any treatment), while the others received 6 mg MSG/kg. The 2nd group was left untreated, whereas the 3rd and 4th groups were given a regular laboratory diet that included ginger rhizome powder supplements (GRP, 0.5 & 1%, respectively) for six weeks. In brain tissue homogenates, exposure to MSG caused a significant depletion of gamma-aminobutyric acid (GABA) and total protein levels, while triglycerides and cholesterol contents were significantly elevated. Moreover, a noteworthy upsurge in oxidative load and inflammation markers was also noticed associated with a marked reduction of antioxidant levels, which histopathological staining verified further. The rat diet formulated with GRP, with a dose-dependent effect, resulted in increased GABA and total protein contents and attenuated inflammation, oxidative stress, abnormal lipid profile, and marked histological changes in cerebral cortical neurons of MSG-administered animals. Therefore, this study reveals that GRP shields rats against the neurotoxicity that MSG causes. The anti-inflammatory as well as antioxidant, and lipid-normalizing properties of rhizomes of ginger may be accountable for their observed neuroprotective action.

Placental, Foetal, and Maternal Serum Metabolomic Profiles in Pregnancy-Associated Cancer: Walker-256 Tumour Model in a Time-Course Analysis

Cancer during pregnancy presents a delicate coexistence, imposing ethical and professional challenges on both the patient and medical team. In this study, we aimed to explore in a pre-clinical model the impact of tumour evolution in serum, placental and foetal metabolomics profiles during pregnancy in a time-course manner. Pregnant Wistar rats were distributed into two experimental groups: Control (C) and Walker-256 tumour-bearing (W). The rats were euthanised on three different gestational periods: at 12 days post-conception (dpc), at 16 dpc, and at 19 dpc. Serum, placenta and foetal metabolomic profiles were performed by 1H-NMR spectra following the analyses using Chenomx NMR Analysis Software V8.3. The tumour evolution was exponential, affecting the placental metabolomic profile during all the pregnancy stages. The placental tissue in tumour-bearing dams developed at a lower speed, decreasing the foetus's weight. Associated with the serum metabolomic changes related to tumour growth, the placental metabolomic alterations impacted many metabolic pathways related to energy provision, protein synthesis and signalling, which directly harmed the foetus's development. The development of the foetus is clearly affected by the damage induced by the tumour evolution, which alters the metabolic profile of both the serum and the placenta, impairing early embryonic development.

Placental pathology in cancer during pregnancy and after cancer treatment exposure

Cancer during pregnancy has been associated with (pathologically) small for gestational age offspring, especially after exposure to chemotherapy in utero. These infants are most likely growth restricted, but sonographic results are often lacking. In view of the paucity of data on underlying pathophysiological mechanisms, the objective was to summarize all studies investigating placental pathology related to cancer(treatment). A systematic search in PubMed/Medline, Embase (OVID) and SCOPUS was conducted to retrieve all studies about placental pathology in cancer during pregnancy or after cancer treatment, published until August 2020. The literature search yielded 5784 unique publications, of which 111 were eligible for inclusion. Among them, three groups of placental pathology were distinguished. First, various histopathologic changes including maternal vascular malperfusion have been reported in pregnancies complicated by cancer and after cancer treatment exposure, which were not specific to type of cancer(treatment). Second, cancer(treatment) has been associated with placental cellular pathology including increased oxidative damage and apoptosis, impaired angiogenesis and genotoxicity. Finally, involvement of the placenta by cancer cells has been described, involving both the intervillous space and rarely villous invasion, with such fetuses are at risk of having metastases. In conclusion, growth restriction is often observed in pregnancies complicated by cancer and its cause can be multifactorial. Placental histopathologic changes, cellular pathology and genotoxicity caused by the cancer(treatment) may each play a role.

Pregnancy and Cancer: Cellular Biology and Mechanisms Affecting the Placenta

Cancer during pregnancy is rarely studied due to its low incidence (1:1000). However, as a result of different sociocultural and economic changes, women are postponing pregnancy, so the number of pregnant women with cancer has been increasing in recent years. The importance of studying cancer during pregnancy is not only based on maternal and foetal prognosis, but also on the evolutionary mechanisms of the cell biology of trophoblasts and neoplastic cells, which point out similarities between and suggest new fields for the study of cancer. Moreover, the magnitude of how cancer factors can affect trophoblastic cells, and vice versa, in altering the foetus's nutrition and health is still a subject to be understood. In this context, the objective of this narrative review was to show that some researchers point out the importance of supplementing branched-chain amino acids, especially leucine, in experimental models of pregnancy associated with women with cancer. A leucine-rich diet may be an interesting strategy to preserve physiological placenta metabolism for protecting the mother and foetus from the harmful effects of cancer during pregnancy.

Pregnancy and Cancer: the INCIP Project

PURPOSE OF REVIEW

Cancer diagnosis in young pregnant women challenges oncological decision-making. The International Network on Cancer, Infertility and Pregnancy (INCIP) aims to build on clinical recommendations based on worldwide collaborative research.

RECENT FINDINGS

A pregnancy may complicate diagnostic and therapeutic oncological options, as the unborn child must be protected from potentially hazardous exposures. Pregnant patients should as much as possible be treated as non-pregnant patients, in order to preserve maternal prognosis. Some approaches need adaptations when compared with standard treatment for fetal reasons. Depending on the gestational age, surgery, radiotherapy, and chemotherapy are possible during pregnancy. A multidisciplinary approach is the best guarantee for experience-driven decisions. A setting with a high-risk obstetrical unit is strongly advised to safeguard fetal growth and health. Research wise, the INCIP invests in clinical follow-up of children, as cardiac function, neurodevelopment, cancer occurrence, and fertility theoretically may be affected. Furthermore, parental psychological coping strategies, (epi)genetic alterations, and pathophysiological placental changes secondary to cancer (treatment) are topics of ongoing research. Further international research is needed to provide patients diagnosed with cancer during pregnancy with the best individualized management plan to optimize obstetrical and oncological care.

Genetic and microscopic assessment of the human chemotherapy-exposed placenta reveals possible pathways contributive to fetal growth restriction

INTRODUCTION

Fetal growth restriction (FGR) carries an increased risk of perinatal mortality and morbidity. A major cause of FGR is placental insufficiency. After in utero chemotherapy-exposure, an increased incidence of FGR has been reported. In a prospective cohort study we aimed to explore which pathways may contribute to chemotherapy-associated FGR.

METHODS

Placental biopsies were collected from 25 cancer patients treated with chemotherapy during pregnancy, and from 66 control patients. Differentially expressed pathways between chemotherapy-exposed patients and controls were examined by whole transcriptome shotgun sequencing (WTSS) and Ingenuity Pathway Analysis (IPA). Immunohistochemical studies for 8-OHdG and eNOS (oxidative DNA damage), proliferation (PCNA) and apoptosis (Cleaved Caspase 3) were performed. The expression level of eNOS, PCNA and IGFBP6 was verified by real-time quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR).

RESULTS

Most differential expressed genes between chemotherapy-exposed patients and controls were related to growth, developmental processes, and radical scavenging networks. The duration of chemotherapy exposure had an additional impact on the expression of genes related to the superoxide radicals degeneration network. Immunohistochemical analyses showed a significantly increased expression of 8-OHdG (P = 0.003) and a decreased expression of eNOS (P=0.015) in the syncytiotrophoblast of the placenta of cancer patients. A decreased expression of PCNA was detected by immunohistochemistry as RT-qPCR (NS).

CONCLUSION

Chemotherapy exposure during pregnancy results in an increase of oxidative DNA damage and might impact the placental cellular growth and development, resulting in an increased incidence of FGR in this specific population. Further large prospective cohort studies and longitudinal statistical analyses are needed.

Dietary leucine supplementation minimises tumour-induced damage in placental tissues of pregnant, tumour-bearing rats

Background

The occurrence of cancer during pregnancy merges two complex, poorly understood metabolic and hormonal conditions. This association can exacerbate the conditions of both the mother and the foetus. The branched-chain amino acid leucine enhances cellular activity, particularly by increasing protein synthesis. This study aimed to analyse the modulatory effect of a leucine-rich diet on direct and indirect tumour-induced placental damage. This was accomplished by evaluating the expression of genes involved in protein synthesis and degradation and assessing anti-oxidant enzyme activity in placental tissues collected from pregnant, tumour-bearing rats.

Results

Pregnant rats were either implanted with Walker 256 tumour cells or injected with ascitic fluid (to study the indirect effects of tumour growth) and then fed a leucine-rich diet. Animals in a control group underwent the same procedures but were fed a normal diet. On the 20^th day of pregnancy, tumour growth was observed. Dams fed a normoprotein diet showed the greatest tumour growth. Injection with ascitic fluid mimicked the effects of tumour growth. Decreased placental protein synthesis and increased protein degradation were observed in both the tumour-bearing and the ascitic fluid-injected groups that were fed a normoprotein diet. These effects resulted in low placental DNA and protein content and high lipid peroxidation (measured by malondialdehyde content). Decreased placental protein synthesis-related gene expression was observed in the tumour group concomitant with increased expression of genes encoding protein degradation-associated proteins and proteolytic subunits.

Conclusions

Consumption of a leucine-rich diet counteracted the effects produced by tumour growth and injection with ascitic fluid. The diet enhanced cell signalling, ameliorated deficiencies in DNA and protein content, and balanced protein synthesis and degradation processes in the placenta. The improvements in cell signalling included changes in the mTOR/eIF pathway. In conclusion, consumption of a leucine-rich diet improved placental metabolism and cell signalling in tumour-bearing rats, and these changes reduced the deleterious effects caused by tumour growth.

Leucine-rich diet supplementation modulates foetal muscle protein metabolism impaired by Walker-256 tumour

BACKGROUND

Cancer-cachexia induces a variety of metabolic disorders of protein turnover and is more pronounced when associated with pregnancy. Tumour-bearing pregnant rats have impaired protein balance, which decreases protein synthesis and increases muscle breakdown. Because branched-chain amino acids, especially leucine, stimulate protein synthesis, we investigated the effect of a leucine-rich diet on protein metabolism in the foetal gastrocnemius muscles of tumour-bearing pregnant rats.

METHODS

Foetuses of pregnant rats with or without Walker 256 tumours were divided into six groups. During the 20 days of the experiment, the pregnant groups were fed with either a control diet (C, control rats; W, tumour-bearing rats; Cp, rats pair-fed the same normoprotein-diet as the W group) or with a leucine-rich diet (L, leucine rats; LW, leucine tumour-bearing rats; and Lp, rats pair-fed the same leucine-rich diet as the LW group). After the mothers were sacrificed, the foetal gastrocnemius muscle samples were resected, and the protein synthesis and degradation and tissue chymotrypsin-like, cathepsin and calpain enzyme activities were assayed. The muscle oxidative enzymes (catalase, glutathione-S-transferase and superoxide dismutase), alkaline phosphatase enzyme activities and lipid peroxidation (malondialdehyde) were also measured.

RESULTS

Tumour growth led to a reduction in foetal weight associated with decreased serum protein, albumin and glucose levels and low haematocrit in the foetuses of the W group, whereas in the LW foetuses, these changes were less pronounced. Muscle protein synthesis (measured by L-[3H]-phenylalanine incorporation) was reduced in the W foetuses but was restored in the LW group. Protein breakdown (as assessed by tyrosine release) was enhanced in the L and W groups, but chymotrypsin-like activity increased only in group W and tended toward an increase in the LW foetuses. The activity of cathepsin H was significantly higher in the W group foetuses, but the proteolytic calcium-dependent pathway showed similar enzyme activity. In parallel, an intense oxidative stress process was observed only in the group W foetuses.

CONCLUSIONS

These data suggested that the proteasomal and lysosomal proteolytic pathways and oxidative stress are likely to participate in the process of foetal muscle catabolism of Walker's tumour-bearing pregnant rats. The present work shows that foetal muscle can be protected by supplementation with a leucine-rich diet.