Inhibition of placental mTOR signaling provides a link between placental malaria and reduced birthweight

Effects of vitrification and the superovulated environment on placental function and fetal growth in an IVF mouse model

In studies of human IVF, as compared to frozen embryo transfer (ET), fresh ET is associated with smaller infants and higher risk of small for gestational age infants. Recent observations suggest that ET using vitrified embryos is associated with higher pregnancy and live birth rates compared to fresh ET, but increased rates of large for gestational age infants. The mechanisms underlying these associations are largely unknown, and available evidence suggests that the influence of IVF, vitrification and the superovulated (SO) uterine environment on placental function and fetal growth is complex. This warrants further investigation given the prevalent practice in human IVF of both fresh ET into a SO uterine environment, and vitrification with ET into a more physiologic uterine environment. Using a mouse model that closely resembles human IVF, we investigated if vitrification of IVF embryos better preserves placental function and results in better pregnancy outcomes as compared to fresh ET because of transfer into a more physiologic endometrium. We found that the SO environment, independent of vitrification status, reduced implantation rates, inhibited placental mechanistic target of rapamycin signaling and induced placental stress signaling, resulting in fetal growth restriction (1.080 ± 0.05 g estrous fresh (n = 17 litters), 1.176 ± 0.05 g estrous vitrified (n = 12), 0.771 ± 0.06 g SO fresh (n = 15), 0.895 ± 0.08 g SO vitrified (n = 10), P < 0.0001). In addition, our study suggests that vitrification impairs the developmental potential of IVF blastocysts that resulted in a significantly smaller litter size (2.6 ± 2.3 fresh estrous vs 2.5 ± 2.4 fresh SO vs 1.6 ± 1.7 estrous vitrified vs 1.7 ± 1.8 SO vitrified, P = 0.019), with no effect on fetal growth or placental function at term. Our findings suggest that vitrification may negatively impact early embryonic viability, while the SO maternal uterine environment impairs both placental development and fetal growth in IVF.

Exploring health-related quality of life among non-Hodgkin's lymphoma survivors after completion of primary treatment: a cross-sectional study in Thailand

PURPOSES

To investigate health-related quality of life (HR-QoL) and its influencing factors among non-Hodgkin's lymphoma (NHL) survivors after completion of primary treatment.

METHODS

A cross-sectional study with 312 NHL survivors after completing primary treatment using self-reported data collected through face-to-face interviews or postal survey between May 2019 and December 2019. Sociodemographic factors, clinical characteristics, physical symptom distress, anxiety, depression, unmet supportive care needs, and adaptation (post-traumatic growth and post-traumatic stress disorder) were assessed. Data analysis included ANOVA tests to investigate HR-QoL among NHL survivors at different time points and GEE to assess predictors of HR-QoL.

RESULTS

The mean score of HR-QoL was 136.05 (SD 19.12). HR-QoL scores reported by NHL survivors in phase I (6 months or less post-treatment) were significantly lower than those in phase II (> 6 months-4 years), phase III (> 4-9 years), and phase IV (over 9 years post-treatment). Regarding HR-QoL domains, NHL survivors in phase I had significantly lower physical well-being and functional well-being scores than those in phases II, III, and IV; and significantly lower lymphoma domain score than those in phase III. GEE analysis showed that physical symptom distress, anxiety, depression, unmet supportive care needs, poor adaptation, and receiving chemotherapy disrupted HR-QoL (all P < .001).

CONCLUSIONS

Healthcare providers should re-prioritize intervention guidelines and survivorship care planning to promote HR-QoL among NHL survivors, particularly in phase I, through reducing physical and psychological symptom distress, addressing unmet needs, and enhancing adaptation outcomes.

A combined flow injection/reversed-phase chromatography-high-resolution mass spectrometry workflow for accurate absolute lipid quantification with 13C internal standards

We propose a fully automated novel workflow for lipidomics based on flow injection, followed by liquid chromatography-high-resolution mass spectrometry (FI/LC-HRMS). The workflow combined in-depth characterization of the lipidome achieved via reversed-phase LC-HRMS with absolute quantification by using a large number of lipid species-specific and/or retention time (RT)-matched/class-specific calibrants. The lipidome of 13C-labelled yeast (LILY) provided a large panel of cost-effective internal standards (ISTDs) covering triacylglycerols (TG), steryl esters (SE), free fatty acids (FA), diacylglycerols (DG), sterols (ST), ceramides (Cer), hexosyl ceramides (HexCer), phosphatidylglycerols (PG), phosphatidylethanolamines (PE), phosphatidic acids (PA), cardiolipins (CL), phosphatidylinositols (PI), phosphatidylserines (PS), phosphatidylcholines (PC), lysophosphatidylcholines (LPC) and lysophosphatidylethanolamines (LPE). The workflow in combination with the LILY lipid panel enables simultaneous quantification via (1) external multi-point calibration with internal standardization and (2) internal one-point calibration with LILY as a surrogate ISTD, increasing the coverage while keeping the accuracy and throughput high. Extensive measures on quality control allowed us to rank the calibration strategies and to automatically select the calibration strategy of the highest metrological order for the respective lipid species. Overall, the workflow enabled a streamlined analysis, with a limit of detection in the low femtomolar range, and provided validation tools together with absolute concentration values for >350 lipids in human plasma on a species level. Based on the selected standard panel, lipids from 7 classes (LPC, LPE, PC, PE, PI, DG, TG) passed stringent quality filters, which included QC accuracy, a precision and recovery bias of <30% and concentrations within the 99% confidence interval of the international laboratory comparison of SRM 1950, NIST, USA. The quantitative values are independent of common deuterated or non-endogenous ISTDs, thus offering cross-validation of different lipid methods and further standardizing lipidomics.

Inhibition of mechanistic target of rapamycin signaling decreases levels of O-GlcNAc transferase and increases serotonin release in the human placenta

Changes in placental function, in particular down-regulation of placental O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) in response to maternal stress and increased placental secretion of serotonin into the fetal circulation following maternal infection, have been mechanistically linked to adverse neurodevelopment in mice. We hypothesized that mechanistic target of rapamycin (mTOR) signaling is a key regulator of trophoblast serotonin synthesis and OGT protein expression and that serotonin is secreted by the human placenta into the fetal circulation. Placental homogenates (n=46) from elective terminations at 8-22 weeks of gestation and from healthy-term women were sexed and the protein levels of OGT and enzymes involved in serotonin synthesis was determined. Primary human trophoblast (PHT) cells were isolated from normal term placenta (n=27), cultured and transfected (n=8) with siRNA targeting a scramble sequence (control), raptor (inhibits mTOR Complex 1 (mTORC1)), or rictor (inhibits mTOR Complex 2 (mTORC2)). Subsequently, conditioned media and PHT cell lysates were collected. Free serotonin concentration was measured using ELISA in cell culture media and in platelet-depleted normal term umbilical vein and artery plasma (n=38). Both mTORC1 and mTORC2 inhibition down-regulated OGT levels in PHT cells. The level of serotonin synthesis enzyme tryptophan hydroxylase (TPH-1) was higher in early gestation female placentas and at term serotonin concentration was three-fold higher in the umbilical vein than in the umbilical artery. Inhibition of mTORC2, but not mTORC1, increased cultured PHT cell serotonin secretion. Our data are consistent with the model that mTOR signaling is a key regulator of trophoblast serotonin synthesis and OGT protein expression.

Poor Birth Outcomes in Malaria in Pregnancy: Recent Insights Into Mechanisms and Prevention Approaches

Pregnant women in malaria-endemic regions are susceptible to malaria in pregnancy, which has adverse consequences on birth outcomes, including having small for gestational age and preterm babies. These babies are likely to have low birthweights, which predisposes to infant mortality and lifelong morbidities. During malaria in pregnancy, Plasmodium falciparum-infected erythrocytes express a unique variant surface antigen, VAR2CSA, that mediates sequestration in the placenta. This process may initiate a range of host responses that contribute to placental inflammation and dysregulated placental development, which affects placental vasculogenesis, angiogenesis and nutrient transport. Collectively, these result in the impairment of placental functions, affecting fetal development. In this review, we provide an overview of malaria in pregnancy and the different pathological pathways leading to malaria in pregnancy-associated low birthweight. We also discuss current prevention and management strategies for malaria in pregnancy, and some potential therapeutic interventions that may improve birth outcomes. Lastly, we outline some priorities for future research that could bring us one step closer to reducing this health burden.

Unraveling Cell Death Pathways during Malaria Infection: What Do We Know So Far?

Malaria is a parasitic disease (caused by different Plasmodium species) that affects millions of people worldwide. The lack of effective malaria drugs and a vaccine contributes to this disease, continuing to cause major public health and socioeconomic problems, especially in low-income countries. Cell death is implicated in malaria immune responses by eliminating infected cells, but it can also provoke an intense inflammatory response and lead to severe malaria outcomes. The study of the pathophysiological role of cell death in malaria in mammalians is key to understanding the parasite-host interactions and design prophylactic and therapeutic strategies for malaria. In this work, we review malaria-triggered cell death pathways (apoptosis, autophagy, necrosis, pyroptosis, NETosis, and ferroptosis) and we discuss their potential role in the development of new approaches for human malaria therapies.

The host mTOR pathway and parasitic diseases pathogenesis

The mechanistic (or mammalian) target of rapamycin (mTOR) is considered as a critical regulatory enzyme involved in essential signaling pathways affecting cell growth, cell proliferation, protein translation, regulation of cellular metabolism, and cytoskeletal structure. Also, mTOR signaling has crucial roles in cell homeostasis via processes such as autophagy. Autophagy prevents many pathogen infections and is involved on immunosurveillance and pathogenesis. Immune responses and autophagy are therefore key host responses and both are linked by complex mTOR regulatory mechanisms. In recent years, the mTOR pathway has been highlighted in different diseases such as diabetes, cancer, and infectious and parasitic diseases including leishmaniasis, toxoplasmosis, and malaria. The current review underlines the implications of mTOR signals and intricate networks on pathogen infections and the modulation of this master regulator by parasites. Parasitic infections are able to induce dynamic metabolic reprogramming leading to mTOR alterations in spite of many other ways impacting this regulatory network. Accordingly, the identification of parasite effects and interactions over such a complex modulation might reveal novel information regarding the biology of the abovementioned parasites and might allow the development of therapeutic strategies against parasitic diseases. In this sense, the effects of inhibiting the mTOR pathways are also considered in this context in the light of their potential for the prevention and treatment of parasitic diseases.

mTORC1 Transcriptional Regulation of Ribosome Subunits, Protein Synthesis, and Molecular Transport in Primary Human Trophoblast Cells

Mechanistic Target of Rapamycin Complex 1 (mTORC1) serves as positive regulator of placental nutrient transport and mitochondrial respiration. The role of mTORC1 signaling in modulating other placental functions is largely unexplored. We used gene array following silencing of raptor to identify genes regulated by mTORC1 in primary human trophoblast (PHT) cells. Seven hundred and thirty-nine genes were differentially expressed; 487 genes were down-regulated and 252 up-regulated. Bioinformatic analyses demonstrated that inhibition of mTORC1 resulted in decreased expression of genes encoding ribosomal proteins in the 60S and 40S ribosome subunits. Furthermore, down-regulated genes were functionally enriched in genes involved in eIF2, sirtuin and mTOR signaling, mitochondrial function, and glutamine and zinc transport. Stress response genes were enriched among up-regulated genes following mTORC1 inhibition. The protein expression of ribosomal proteins RPL26 (RPL26) and Ribosomal Protein S10 (RPS10) was decreased and positively correlated to mTORC1 signaling and System A amino acid transport in human placentas collected from pregnancies complicated by intrauterine growth restriction (IUGR). In conclusion, mTORC1 signaling regulates the expression of trophoblast genes involved in ribosome and protein synthesis, mitochondrial function, lipid metabolism, nutrient transport, and angiogenesis, representing novel links between mTOR signaling and multiple placental functions critical for normal fetal growth and development.

Does cereal, protein and micronutrient availability hold the key to the malnutrition conundrum? An exploratory analysis of cereal cultivation and wasting patterns of India

Background: High prevalence of maternal malnutrition, low birth-weight and child malnutrition in India contribute substantially to the global malnutrition burden. Rural India has disproportionately higher levels of child malnutrition. Stunting and wasting are the primary determinants of child malnutrition and their district-level distribution shows clustering in different geographies and regions. Methods: The last round of National Family Health Survey (NFHS4) has disaggregated data by district, enabling a more nuanced understanding of the prevalence of markers of malnutrition. We used data from NFHS4 and agricultural statistics datasets to analyse relationship of area under cereal cultivation with the prevalence of malnutrition at the district level. We analysed malnutrition through data on under-5 stunting and wasting; maternal malnutrition was assessed through prevalence of women's low BMI and short stature by district.  Results: Stunting and wasting patterns across districts show a distinct geographical and age distribution; districts with higher wasting showed relatively high prevalence of 40% before six months of age. Wasting was associated with higher cultivation of millets, with a stronger association seen for jowar and other millets (Kodo millet, little millet, proso millet, barnyard millet and foxtail millet). Stunting was associated with cultivation of all crops except other millets. Low women's BMI was seen associated with cultivation of rice and millets. The analysis was limited by lack of fine-scale data on prevalence of low birth-weight and type of cereal consumed. Conclusions: Multi-site observational studies of long-term effects of type of cereals consumed could help explain the ecogeographic distribution of malnutrition in India. Cereals, particularly millets constitute the bulk of protein intake among the poor, especially in rural areas in India where high prevalence of  wasting persists.

Maternal inflammation leads to different mTORC1 activity varied by anatomic locations in mouse placenta†

Maternal inflammation (MI) is associated with many adverse perinatal outcomes. The placenta plays a vital role in mediating maternal-fetal resource allocation. Studies have shown that MI contributes to placental dysfunction, which then leads to adverse birth outcomes and high health risks throughout childhood. Placental mammalian target of rapamycin complex 1 (mTORC1) signaling pathway links maternal nutrient availability to fetal growth; however, the impact of MI on mTORC1 signaling in the placenta remains unclear. In this study, we sought to explore the changes of mTORC1 signaling in the mouse placenta at late gestation by using two models of MI employing lipopolysaccharide (LPS) and interleukin-1β (IL-1β) to mimic acute (aMI) and sub-chronic (cMI) inflammatory states, respectively. We determined placental mTORC1 activity by measuring the activity of mTORC1 downstream molecules, including S6k, 4Ebp1, and rpS6. In the aMI model, we found that mTORC1 activity was significantly decreased in the placental decidual and junctional zone at 2 and 6 h after LPS surgery, respectively; however, mTORC1 activity was significantly increased in the placental labyrinth zone at 2, 6, and 24 h after LPS treatment, respectively. In the cMI model, we observed that mTORC1 activity was increased only in the placental labyrinth zone after consecutive IL-1β exposure. Our study reveals that different parts of the mouse placenta react differently to MI, leading to variable mTORC1 activity throughout the placenta. This suggests that different downstream molecules of mTORC1 from different parts of the mouse placenta may be used in clinical research to monitor the fetal well-being during MI.

Is the minimal clinically important difference (MCID) in acute pain a good measure of analgesic efficacy in regional anesthesia?

In the field of acute pain medicine research, we believe there is an unmet need to incorporate patient related outcome measures that move beyond reporting pain scores and opioid consumption. The term “minimal clinically important difference” (MCID) defines the clinical benefit of an intervention as perceived by the patient, as opposed to a mathematically determined statistically significant difference that may not necessarily be clinically significant. The present article reviews the concept of MCID in acute postoperative pain research, addresses potential pitfalls in MCID determination and questions the clinical validity of extrapolating MCID determined from chronic pain and non-surgical pain studies to the acute postoperative pain setting. We further suggest the concepts of minimal clinically important improvement, substantial clinical benefit and patient acceptable symptom state should also represent aspirational outcomes for future research in acute postoperative pain management.

Placental function in maternal obesity

Maternal obesity is associated with pregnancy complications and increases the risk for the infant to develop obesity, diabetes and cardiovascular disease later in life. However, the mechanisms linking the maternal obesogenic environment to adverse short- and long-term outcomes remain poorly understood. As compared with pregnant women with normal BMI, women entering pregnancy obese have more pronounced insulin resistance, higher circulating plasma insulin, leptin, IGF-1, lipids and possibly proinflammatory cytokines and lower plasma adiponectin. Importantly, the changes in maternal levels of nutrients, growth factors and hormones in maternal obesity modulate placental function. For example, high insulin, leptin, IGF-1 and low adiponectin in obese pregnant women activate mTOR signaling in the placenta, promoting protein synthesis, mitochondrial function and nutrient transport. These changes are believed to increase fetal nutrient supply and contribute to fetal overgrowth and/or adiposity in offspring, which increases the risk to develop disease later in life. However, the majority of obese women give birth to normal weight infants and these pregnancies are also associated with activation of inflammatory signaling pathways, oxidative stress, decreased oxidative phosphorylation and lipid accumulation in the placenta. Recent bioinformatics approaches have expanded our understanding of how maternal obesity affects the placenta; however, the link between changes in placental function and adverse outcomes in obese women giving birth to normal sized infants is unclear. Interventions that specifically target placental function, such as activation of placental adiponectin receptors, may prevent the transmission of metabolic disease from obese women to the next generation.

Ursodeoxycholic acid improves feto-placental and offspring metabolic outcomes in hypercholanemic pregnancy

Perturbations in the intrauterine environment can result in lifelong consequences for metabolic health during postnatal life. Intrahepatic cholestasis of pregnancy (ICP) can predispose offspring to metabolic disease in adulthood, likely due to a combination of the effects of increased bile acids, maternal dyslipidemia and deranged maternal and fetal lipid homeostasis. Whereas ursodeoxycholic acid (UDCA) is a commonly used treatment for ICP, no studies have yet addressed whether it can also prevent the metabolic effects of ICP in the offspring and fetoplacental unit. We therefore analyzed the lipid profile of fetal serum from untreated ICP, UDCA-treated ICP and uncomplicated pregnancies and found that UDCA ameliorates ICP-associated fetal dyslipidemia. We then investigated the effects of UDCA in a mouse model of hypercholanemic pregnancy and showed that it induces hepatoprotective mechanisms in the fetal liver, reduces hepatic fatty acid synthase (Fas) expression and improves glucose tolerance in the adult offspring. Finally, we showed that ICP leads to epigenetic changes in pathways of relevance to the offspring phenotype. We therefore conclude that UDCA can be used as an intervention in pregnancy to reduce features of metabolic disease in the offspring of hypercholanemic mothers.

Does cereal, protein and micronutrient availability hold the key to the malnutrition conundrum? An exploratory analysis of cereal cultivation and wasting patterns of India

Background: High prevalence of maternal malnutrition, low birth-weight and child malnutrition in India contribute substantially to the global malnutrition burden. Rural India has disproportionately higher levels of child malnutrition. Stunting and wasting are the primary determinants of malnutrition and their district-level distribution shows clustering in different geographies and regions. Methods: The last round of National Family Health Survey (NFHS4) has disaggregated data by district, enabling a more nuanced understanding of the prevalence of markers of malnutrition. We used data from NFHS4 and agricultural statistics datasets to analyse relationship of cereal cultivation with the prevalence of child malnutrition. We studied the current science on growth-related nutrient-sensing pathways to explain this pattern.  Results: Stunting and wasting patterns across districts show a distinct geographical and age distribution; districts with higher wasting showed early prevalence of 40% at six months of age. Wasting was associated with higher cultivation of millets, with a stronger association seen for jowar and other millets. Low maternal BMI in districts with higher wasting could be linked to the consumption of millets as staple. We conceptualised a hypothetical schematic pathway linking early origin of wasting in children with millet-based diet, driven by inhibition of critical intra-cellular pathways controlling growth covering pre-natal, post-natal and early childhood. The analysis was limited by lack of fine-scale data on prevalence of low birth-weight and type of cereal consumed. Conclusions: Multi-site observational studies of long-term effects of type of cereals consumed could help explain the ecogeographic distribution of malnutrition in India. Cereals, particularly millets constitute the bulk of protein intake among the poor, especially in rural areas in India where wasting persists. Policies and programs targeting malnutrition need to address type of cereal consumed in order to impact childhood malnutrition in parts of India where subsistence cultivation of millets for staple consumption is prevalent.

Repeat assessment of examination signs among children in Malawi with fast-breathing pneumonia

Background

As part of a randomised controlled trial of treatment with placebo versus 3 days of amoxicillin for nonsevere fast-breathing pneumonia among Malawian children aged 2–59 months, a subset of children was hospitalised for observation. We sought to characterise the progression of fast-breathing pneumonia among children undergoing repeat assessments to better understand which children do and do not deteriorate.

Methods

Vital signs and physical examination findings, including respiratory rate, arterial oxygen saturation measured by pulse oximetry (S_pO2), chest indrawing and temperature were assessed every 3 h for the duration of hospitalisation. Children were assessed for treatment failure during study visits on days 1, 2, 3 and 4.

Results

Hospital monitoring data from 436 children were included. While no children had S_pO2 90–93% at baseline, 7.4% (16 of 215) of children receiving amoxicillin and 9.5% (21 of 221) receiving placebo developed S_pO2 90–93% during monitoring. Similarly, no children had chest indrawing at enrolment, but 6.6% (14 of 215) in the amoxicillin group and 7.2% (16 of 221) in the placebo group went on to develop chest indrawing during hospitalisation.

Conclusion

Repeat monitoring of children with fast-breathing pneumonia identified vital and physical examination signs not present at baseline, including S_pO2 90–93% and chest indrawing. This information may support providers and policymakers in developing guidance for care of children with nonsevere pneumonia.

This study characterised the progression of fast-breathing pneumonia among children in Malawi. Repeat monitoring of children identified vital and physical exam signs not present at baseline, including oxygen saturation of 90–93% and chest indrawing.http://bit.ly/2vUlckS

Does body mass index impact assisted reproductive technology treatment outcomes in gestational carriers

BACKGROUND

The purpose of this study was to assess whether increased body mass index (BMI) negatively affects assisted reproductive technology (ART) outcomes among gestational carriers.

METHODS

A retrospective matched case-control cohort, including all gestational carrier (GC) cycles performed at CReATe Fertility Centre (Toronto, ON, Canada) between 2003 and 2016.

SETTING

A Canadian fertility clinic, with a large surrogacy program.

PATIENTS

All gestational carriers that had undergone a cycle completed to a transfer at our clinic, and had BMI and outcome data available, were matched by BMI to infertile patients treated at our clinic during the same years provided they had undergone a cycle completed to a transfer, and had outcomes data available.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Clinical pregnancies rates, miscarriage rates and live birth rates.

RESULTS

BMI was not a reliable prediction factor of any of the measured outcomes. Importantly, the gestational carrier population had better outcomes and a significantly lower overall incidence of maternal, fetal and neonatal complications when compared with infertile patients, treated at our clinic during the same years.

CONCLUSION

BMI is not a reliable predictor of outcomes among gestational carriers.

Uptake of intermittent preventive treatment for malaria during pregnancy with Sulphadoxine-Pyrimethamine in Malawi after adoption of updated World Health Organization policy: an analysis of demographic and health survey 2015-2016

Background

Malawi adopted the 2012 updated Word Health Organization (WHO) Intermittent preventive treatment of malaria during pregnancy with sulphadoxine-pyrimethamine (IPTp-SP) policy in 2013. This study aimed to estimate the proportion of and identify factors associated with the uptake of at least three doses of IPTp with SP among pregnant women in Malawi after the adoption and operationalisation of updated WHO IPTp-SP policy.

Methods

The 2015–16 Malawi Demographic and Health Survey dataset was analysed. Of 1219 women aged 15–49 years who had live births and the children were born after the date of July 2015, 1069 women were included in the analysis. Bivariate and multiple logistic regression were used in data analysis. The statistical analysis took into account a complex survey sample design.

Results

Of the 1069 women, 447 (42, 95% CI: 38.1–45.6) received three (optimal) or more doses of IPTp-SP. Less than half (47%) managed to attend at least four antenatal care (ANC) clinics. Only 52% received optimal SP doses among those who made at least four ANC visits. Only the number of ANC visits was associated with the optimal uptake of SP. Women who attended ANC three times only and those who visited ANC once or twice only were less likely to receive at least three doses of SP than those who managed to attend ANC at least four times during pregnancy (AOR = 0.71, 95% CI 0.49–1.02) and (AOR = 0.12, 95% CI 0.06–0.21) respectively.

Conclusions

To achieve effective malaria prevention in pregnancy, IPTP-SP is used alongside other interventions. However, there is low uptake of optimal SP doses in Malawi, and this seems to be associated with the number of ANC visits. Moreover, there is limited effectiveness of an increased number of ANC visits on the uptake of optimal SP doses. Further research should be done to explore health systems factors affecting uptake of optimal IPTp with SP doses during pregnancy.

Effectiveness of Sulfadoxine-Pyrimethamine for Intermittent Preventive Treatment of Malaria and Adverse Birth Outcomes in Pregnant Women

Effectiveness of intermittent preventive treatment in pregnancy with sulfadoxine–pyrimethamine (IPTp-SP) for prevention of malaria and adverse birth outcomes can be compromised by parasites-resistance to sulfadoxine–pyrimethamine. This study prospectively evaluated the effectiveness of IPTp-SP in Southeast Tanzania. From January 2017 to May 2019, HIV-negative and malaria-negative (mRDT) pregnant women attending their first antenatal-care visit in the second or third trimester (n = 500) were enrolled to receive monthly IPTp-SP and followed the protocol till delivery. The primary outcome was the prevalence of histopathological placental malaria. Secondary outcomes were anemia, malaria parasites detected during pregnancy and at delivery, adverse birth outcomes (low-birth-weight [LBW], premature birth, fetal anemia, still birth, and spontaneous abortion). Rates of histopathological placental malaria, any parasitemia at delivery (placental, cord or maternal), and any adverse birth outcome were 9.4%, 20.9%, and 26.5%, respectively. Rates of symptomatic malaria and parasitemia during pregnancy were 2.8% and 16%, respectively. Histopathological placental malaria significantly increased the odds of any adverse birth outcomes, particularly LBW. IPTp-SP with more than or equal to three doses significantly improved birth weight and reduced the risk of LBW by 56% compared to <3 SP doses (p = 0.009). IPTp-SP with more than or equal to three doses is still effective in improving birth weight. However, the detection of histopathological placental-malaria in one-tenth and parasitemia in one-fifth of pregnant women reflects the need to optimize the prevention of malaria during pregnancy.

Complex, coordinated and highly regulated changes in placental signaling and nutrient transport capacity in IUGR

The most common cause of intrauterine growth restriction (IUGR) in the developed world is placental insufficiency, a concept often used synonymously with reduced utero-placental and umbilical blood flows. However, placental insufficiency and IUGR are associated with complex, coordinated and highly regulated changes in placental signaling and nutrient transport including inhibition of insulin and mTOR signaling and down-regulation of specific amino acid transporters, Na+/K+-ATPase, the Na+/H+-exchanger, folate and lactate transporters. In contrast, placental glucose transport capacity is unaltered and Ca2+-ATPase activity and the expression of proteins involved in placental lipid transport are increased in IUGR. These findings are not entirely consistent with the traditional view that the placenta is dysfunctional in IUGR, but rather suggest that the placenta adapts to reduce fetal growth in response to an inability of the mother to allocate resources to the fetus. This new model has implications for the understanding of the mechanisms underpinning IUGR and for the development of intervention strategies.

Potentially inappropriate prescribing in dementia: a state-of-the-art review since 2007

OBJECTIVES

Dementia frequently occurs alongside comorbidities. Coexisting conditions are often managed with multiple medications, leading to increased risk of potentially inappropriate medication and adverse drug reactions. We aimed to estimate prevalence of, and identify factors reported to be associated with, potentially inappropriate prescribing (PIP) for older individuals diagnosed with dementia.

DESIGN

We used a state-of-the-art review approach, selecting papers written in English and published from 2007 to January 2018. Publications were retrieved from Scopus and Web of Science databases. Inclusion criteria included a formal diagnosis of dementia, a formal classification of PIP and reported prevalence of PIP as an outcome. Random effects models were used to provide a pooled estimate of prevalence of PIP. The Appraisal tool for Cross-Sectional Studies (AXIS tool) was used to assess bias in the included studies.

RESULTS

The bibliographic search yielded 221 citations, with 12 studies meeting the inclusion criteria. The estimates of PIP prevalence for people living with dementia ranged from 14% to 64%. Prevalence was 31% (95% CI 9 to 52) in the community, and 42% (95% CI 30 to 55) in nursing/care homes. PIP included prescribing likely related to dementia (eg, hypnotics and sedative and cholinesterase inhibitors) and prescribing related to treatment of comorbidities (eg, cardiovascular drugs and non-steroidal anti-inflammatory medication). Higher levels of comorbidity were associated with increased risk of PIP; however, only one study investigated associations with specific comorbidities of dementia.

CONCLUSION

PIP remains a significant issue in healthcare management for people living with dementia. Higher levels of comorbidity are associated with increased prevalence of PIP, but the specific conditions driving this increase remain unknown. Further work is necessary to investigate PIP related to the presence of common comorbidities in patients living with dementia.

A novel murine model for assessing fetal and birth outcomes following transgestational maternal malaria infection

Plasmodium falciparum infection during pregnancy is a major cause of severe maternal illness and neonatal mortality. Mouse models are important for the study of gestational malaria pathogenesis. When infected with Plasmodium chabaudi chabaudi AS in early gestation, several inbred mouse strains abort at midgestation. We report here that outbred Swiss Webster mice infected with P. chabaudi chabaudi AS in early gestation carry their pregnancies to term despite high parasite burden and malarial hemozoin accumulation in the placenta at midgestation, with the latter associated with induction of heme oxygenase 1 expression. Infection yields reduced fetal weight and viability at term and a reduction in pup number at weaning, but does not influence postnatal growth prior to weaning. This novel model allows for the exploration of malaria infection throughout pregnancy, modeling chronic infections observed in pregnant women prior to the birth of underweight infants and enabling the production of progeny exposed to malaria in utero, which is critical for understanding the postnatal repercussions of gestational malaria. The use of outbred mice allows for the exploration of gestational malaria in a genetically diverse model system, better recapitulating the diversity of infection responses observed in human populations.

The efficacy of intermittent preventive therapy in the eradication of peripheral and placental parasitemia in a malaria-endemic environment, as seen in a tertiary hospital in Abuja, Nigeria

OBJECTIVE

To determine whether intermittent preventive therapy in pregnancy (IPTp) eradicates peripheral and placental malaria and improves birth weight.

METHOD

A cross-sectional study was conducted of 426 pregnant mothers on IPTp with sulphadoxine-pyrimethamine against malaria who presented in labor, at National Hospital Abuja, Nigeria between January and June 2017. The hospital is within the malaria-endemic zone of West Africa. Consenting pregnant women with uncomplicated singleton term pregnancy who had antenatal care in the hospital and lived in the study area for at least 6 months were consecutively recruited. Peripheral and placental blood were collected and examined for malaria parasite by microscopy. Babies were weighed at birth.

RESULTS

The prevalence of peripheral malaria parasitemia and placental parasitization were 12.9% (95% confidence interval [CI] 10.0-16.6) and 9.4% (95% CI 7.0-12.7), respectively. Parasite density in both peripheral parasitemia and placental parasitization was low among the women that took IPTp, decreasing with increasing doses, with no parasitemia or parasitization in women that took up to three doses. Birth weight was lower in babies of mothers with plasmodium infestation than in those without infestation (P<0.001, P=0.024).

CONCLUSION

IPTp reduces both peripheral parasitemia and placental parasitization, with the capacity to eliminate or prevent them. IPTp also reduces low birth weight.

Plasmodium falciparum infection dysregulates placental autophagy

Plasmodium (P.) falciparum malaria during pregnancy has been frequently associated with severe consequences such as maternal anemia, abortion, premature birth, and reduced birth weight. Placental damage promotes disruption of the local homeostasis; though, the mechanisms underlying these events are still to be elucidated. Autophagy is a fundamental homeostatic mechanism in the natural course of pregnancy by which cells self-recycle in order to survive in stressful environments. Placentas from non-infected and P. falciparum-infected women during pregnancy were selected from a previous prospective cohort study conducted in the Brazilian Amazon (Acre, Brazil). Newborns from infected women experienced reduced birth weight (P = 0.0098) and placental immunopathology markers such as monocyte infiltrate (P < 0.0001) and IL-10 production (P = 0.0122). The placentas were evaluated for autophagy-related molecules. As a result, we observed reduced mRNA levels of ULK1 (P = 0.0255), BECN1 (P = 0.0019), and MAP1LC3B (P = 0.0086) genes in placentas from P. falciparum-infected, which was more striking in those diagnosed with placental malaria. Despite the protein levels of these genes followed the same pattern, the observed reduction was not statistically significant in placentas from P. falciparum-infected women. Nevertheless, our data suggest that chronic placental immunopathology due to P. falciparum infection leads to autophagy dysregulation, which might impair local homeostasis during malaria in pregnancy that may result in poor pregnancy outcomes.

Biosensors for Detection of Human Placental Pathologies: A Review of Emerging Technologies and Current Trends

Substantial growth in the biosensor research has enabled novel, sensitive and point-of-care diagnosis of human diseases in the last decade. This paper presents an overview of the research in the field of biosensors that can potentially predict and diagnosis of common placental pathologies. A survey of biomarkers in maternal circulation and their characterization methods is presented, including markers of oxidative stress, angiogenic factors, placental debris, and inflammatory biomarkers that are associated with various pathophysiological processes in the context of pregnancy complications. Novel biosensors enabled by microfluidics technology and nanomaterials is then reviewed. Representative designs of plasmonic and electrochemical biosensors for highly sensitive and multiplexed detection of biomarkers, as well as on-chip sample preparation and sensing for automatic biomarker detection are illustrated. New trends in organ-on-a-chip based placental disease models are highlighted to illustrate the capability of these in vitro disease models in better understanding the complex pathophysiological processes, including mass transfer across the placental barrier, oxidative stress, inflammation, and malaria infection. Biosensor technologies that can be potentially embedded in the placental models for real time, label-free monitoring of these processes and events are suggested. Merger of cell culture in microfluidics and biosensing can provide significant potential for new developments in advanced placental models, and tools for diagnosis, drug screening and efficacy testing.

Combating low birth weight due to malaria infection in pregnancy

Decreased l-arginine and nitric oxide bioavailability in pregnant women with malaria contributes to low birth weight, suggesting that l-arginine supplementation could be a potential treatment (McDonald et al).

Malaria in pregnancy alters l-arginine bioavailability and placental vascular development

Reducing adverse birth outcomes due to malaria in pregnancy (MIP) is a global health priority. However, there are few safe and effective interventions. L-arginine is an essential amino acid in pregnancy and an immediate precursor in the biosynthesis of nitric oxide (NO), but there are limited data on the impact of MIP on NO biogenesis. We hypothesized that hypoarginemia contributes to the pathophysiology of MIP and that L-arginine supplementation would improve birth outcomes. In a prospective study of pregnant Malawian women, we show that MIP was associated with lower concentrations of L- arginine and higher concentrations of endogenous inhibitors of NO biosynthesis, asymmetric and symmetric dimethylarginine, which were associated with adverse birth outcomes. In a model of experimental MIP, L-arginine supplementation in dams improved birth outcomes (decreased stillbirth and increased birth weight) compared with controls. The mechanism of action was via normalized angiogenic pathways and enhanced placental vascular development, as visualized by placental microcomputerized tomography imaging. These data define a role for dysregulation of NO biosynthetic pathways in the pathogenesis of MIP and support the evaluation of interventions to enhance L-arginine bioavailability as strategies to improve birth outcomes.

Composition of the gut microbiota transcends genetic determinants of malaria infection severity and influences pregnancy outcome

BACKGROUND

Malaria infection in pregnancy is a major cause of maternal and foetal morbidity and mortality worldwide. Mouse models for gestational malaria allow for the exploration of the mechanisms linking maternal malaria infection and poor pregnancy outcomes in a tractable model system. The composition of the gut microbiota has been shown to influence susceptibility to malaria infection in inbred virgin mice. In this study, we explore the ability of the gut microbiota to modulate malaria infection severity in pregnant outbred Swiss Webster mice.

METHODS

In Swiss Webster mice, the composition of the gut microbiota was altered by disrupting the native gut microbes through broad-spectrum antibiotic treatment, followed by the administration of a faecal microbiota transplant derived from mice possessing gut microbes reported previously to confer susceptibility or resistance to malaria. Female mice were infected with P. chabaudi chabaudi AS in early gestation, and the progression of infection and pregnancy were tracked throughout gestation. To assess the impact of maternal infection on foetal outcomes, dams were sacrificed at term to assess foetal size and viability. Alternatively, pups were delivered by caesarean section and fostered to assess neonatal survival and pre-weaning growth in the absence of maternal morbidity. A group of dams was also euthanized at mid-gestation to assess infection and pregnancy outcomes.

FINDINGS

Susceptibility to infection varied significantly as a function of source of transplanted gut microbes. Parasite burden was negatively correlated with the abundance of five specific OTUs, including Akkermansia muciniphila and OTUs classified as Allobaculum, Lactobacillus, and S24-7 species. Reduced parasite burden was associated with reduced maternal morbidity and improved pregnancy outcomes. Pups produced by dams with high parasite burdens displayed a significant reduction in survival in the first days of life relative to those from malaria-resistant dams when placed with foster dams. At midgestation, plasma cytokine levels were similar across all groups, but expression of IFNγ in the conceptus was elevated in infected dams, and IL-10 only in susceptible dams. In the latter, transcriptional and microscopic evidence of monocytic infiltration was observed with high density infection; likewise, accumulation of malaria haemozoin was enhanced in this group. These responses, combined with reduced vascularization of the placenta in this group, may contribute to poor pregnancy outcomes. Thus, high maternal parasite burden and associated maternal responses, potentially dictated by the gut microbial community, negatively impacts term foetal health and survival in the early postnatal period.

INTERPRETATION

The composition of the gut microbiota in Plasmodium chabaudi chabaudi AS-infected pregnant Swiss Webster mice transcends the outbred genetics of the Swiss Webster mouse stock as a determinant of malaria infection severity, subsequently influencing pregnancy outcomes in malaria-exposed progeny. FUND: Research reported in this manuscript was supported by the University of Florida College of Veterinary Medicine (JMM, MM, and MG), the National Institute of Allergy and Infectious Diseases, the National Institute of Diabetes and Digestive and Kidney Diseases, and the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health under award numbers T32AI060546 (to CDMS), R01HD46860 and R21AI111242 (to JMM), and R01 DK109560 (to MM). MG was supported by Department of Infectious Diseases and Immunology and University of Florida graduate assistantships. AA was supported by the 2017-2019 Peach State LSAMP Bridge to the Doctorate Program at the University of Georgia (National Science Foundation, Award # 1702361). The content is solely the responsibility of the authors and does not necessarily represent official views of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute of Allergy and Infectious Diseases, the National Institute of Diabetes and Digestive and Kidney Diseases, or the National Institutes of Health.

Downregulation of receptor tyrosine kinase-like orphan receptor 1 in preeclampsia placenta inhibits human trophoblast cell proliferation, migration, and invasion by PI3K/AKT/mTOR pathway accommodation

INTRODUCTION

Invasive deficiency of the trophoblast and poor remodeling of the uterine spiral arteries were probably the primary pathogenesis causes of preeclampsia (PE). The expression of receptor tyrosine kinase-like orphan receptor 1 (ROR1) during embryogenesis had been previously confirmed and was closely related to the function of tumor cells, which was similar to the characteristics of trophoblasts. In this work, we investigated the expression profile of ROR1 in preeclampsia placentas and the functional role of ROR1 in trophoblast cells, as well as the associated molecular mechanisms.

METHODS

The localization expression of ROR1 in the placenta was detected by immunohistochemistry in 20 cases of normal term pregnancy, preterm delivery, late-onset severe PE, and early-onset severe PE, respectively. The expression levels were determined by fluorescence quantitative PCR and Western blot. The influence of ROR1 on trophoblast proliferation, migration, invasion, and potential regulatory pathways was evaluated in HTR-8/SVneo cell lines by transient transfection methods.

RESULTS

The levels of ROR1 in the placental tissues in PE were significantly lower than those in normal term pregnancy and preterm delivery. Moreover, the expression levels of ROR1 in early-onset severe PE were significantly lower than those in its late counterparts. ROR1 overexpression increased cell proliferation, migration, and invasion of HTR-8/SVneo cells, whereas its silencing had the opposite effect. Meanwhile, the phosphorylation levels of critical kinases in the PI3K/AKT/mTOR pathways were increased by ROR1 overexpression, whereas they were decreased by the silencing of ROR1.

CONCLUSION

ROR1 might be involved in the development of PE through regulating trophoblast viability, migration, and invasion by PI3K/AKT/mTOR signaling pathway.

Differential Activation of Fetal Hofbauer Cells in Primigravidas Is Associated with Decreased Birth Weight in Symptomatic Placental Malaria

Background

Placental malaria is a leading global cause of low birth weight neonates, especially in first-time mothers. To better understand the role of innate immunity in placental malaria, we investigated the relationships between histopathological markers of placental malaria, fetal and maternal macrophage responses, and perinatal outcomes in a cross-sectional case control study of pregnant women presenting with symptomatic malaria at the time of delivery.

Results

Primigravidas showed increased hemozoin deposition in placental villi (p=0.02), syncytiotrophoblasts (p=0.01), and fetal Hofbauer cells (p=0.01). The percentage of hemozoin-positive villi negatively correlated with infant birth weight (regression coefficient [b] = -0.03 kg decrease in birth weight per % increase in hemozoin-positive villi, p=0.035). Malaria-infected placentas showed a twofold increase in Hofbauer cells (p<0.001) and maternal macrophages (p<0.001). Placental malaria was associated with a threefold increase in the percentage of M2 maternal macrophages (19.2% vs 6.4%, p=0.01). Primigravidas showed a significant decrease in the Hofbauer cell M2-percentage in placental malaria (92.7% vs. 97.0%, p=0.04), which was predictive of infant birth weight (b=0.08 kg increase in birth weight per % increase in M2 Hofbauer cells, p=0.001). There was no association between maternal macrophage response and infant birth weights.

Conclusions

Placentas with malarial infection had increased numbers of fetal Hofbauer cells in the villous stroma and maternal macrophages in the intervillous space. In primigravidas, decreased anti-inflammatory M2-type Hofbauer cells were predictive of lower birth weight. M2-type maternal macrophages were increased in placental malaria, but there was no association with gravidity or birth weight. These results suggested a protective role of M2 Hofbauer cells in fetal growth restriction.

Molecular Principles of Intrauterine Growth Restriction in Plasmodium Falciparum Infection

Malaria in pregnancy still constitutes a particular medical challenge in tropical and subtropical regions. Of the five Plasmodium species that are pathogenic to humans, infection with Plasmodium falciparum leads to fulminant progression of the disease with massive impact on pregnancy. Severe anemia of the mother, miscarriage, stillbirth, preterm delivery and intrauterine growth restriction (IUGR) with reduced birth weight are frequent complications that lead to more than 10,000 maternal and 200,000 perinatal deaths annually in sub-Saharan Africa alone. P. falciparum can adhere to the placenta via the expression of the surface antigen VAR2CSA, which leads to sequestration of infected erythrocytes in the intervillous space. This process induces a placental inflammation with involvement of immune cells and humoral factors. Especially, monocytes get activated and change the release of soluble mediators, including a variety of cytokines. This proinflammatory environment contributes to disorders of angiogenesis, blood flow, autophagy, and nutrient transport in the placenta and erythropoiesis. Collectively, they impair placental functions and, consequently, fetal growth. The discovery that women in endemic regions develop a certain immunity against VAR2CSA-expressing parasites with increasing number of pregnancies has redefined the understanding of malaria in pregnancy and offers strategies for the development of vaccines. The following review gives an overview of molecular processes in P. falciparum infection in pregnancy which may be involved in the development of IUGR.

Integrated Proteomics Reveals Apoptosis-related Mechanisms Associated with Placental Malaria

Malaria in pregnancy is a public health concern in malaria-endemic areas. Accumulation of maternal immune cells in the placenta and increased levels of inflammatory cytokines caused by sequestration of Plasmodium falciparum-infected erythrocytes have been associated to poor neonatal outcomes, including low birth weight because of fetal growth restriction. Little is known about the molecular changes occurring in a P. falciparum-infected placenta that has developed placental malaria during pregnancy but had the parasites cleared by pharmacological treatment (past infection). We conducted an integrated proteome, phosphoproteome and glycoproteome analysis in past P. falciparum-infected placentas aiming to find molecular changes associated with placental malaria. A total of 2946 proteins, 1733 N-linked glycosites and 4100 phosphosites were identified and quantified in this study, disclosing overrepresented processes related to oxidative stress, protein folding and regulation of apoptosis in past-infected placentas Moreover, AKT and ERK signaling pathways activation, together with clinical data, were further correlated to an increased apoptosis in past-infected placentas. This study showed apoptosis-related mechanisms associated with placental malaria that can be further explored as therapeutic target against adverse pregnancy outcomes.

DEPTOR at the Nexus of Cancer, Metabolism, and Immunity

DEP domain-containing mechanistic target of rapamycin (mTOR)-interacting protein (DEPTOR) is an important modulator of mTOR, a kinase at the center of two important protein complexes named mTORC1 and mTORC2. These highly studied complexes play essential roles in regulating growth, metabolism, and immunity in response to mitogens, nutrients, and cytokines. Defects in mTOR signaling have been associated with the development of many diseases, including cancer and diabetes, and approaches aiming at modulating mTOR activity are envisioned as an attractive strategy to improve human health. DEPTOR interaction with mTOR represses its kinase activity and rewires the mTOR signaling pathway. Over the last years, several studies have revealed key roles for DEPTOR in numerous biological and pathological processes. Here, we provide the current state of the knowledge regarding the cellular and physiological functions of DEPTOR by focusing on its impact on the mTOR pathway and its role in promoting health and disease.

Methionine Partially Replaced by Methionyl-Methionine Dipeptide Improves Reproductive Performance over Methionine Alone in Methionine-Deficient Mice

Decreased protein breakdown in pregnant women results in lower concentration of methionine (Met) in plasma, causing pregnancy-related metabolic disturbance. Its dipeptide methionyl-methionine (Met-Met) may exert positive influence in fetal development. This study mainly investigated whether Met-Met can be used as part of free Met to promote reproductive outcomes in mice and the underlying mechanisms. Met-deficient pregnant mice were treated with Met alone or with Met-Met during pregnancy. Daily intraperitoneal injection of 35% dietary Met in pregnant mice was the best dose among the 15–45% doses. Embryo development and newborn birth weight were enhanced when 25% of the Met in the 35% Met group was replaced with Met-Met. Met-Met replacement had higher plasma insulin, glucose, and free amino acids (AA) concentrations. Besides, in the placenta, the AA transporter mRNA abundances and peptide transporters (PhT1 and PepT1) protein levels were higher in Met-Met treatment group. Moreover, Met-Met increased 4E-BP1, S6K1 and AKT/mTOR phosphorylation. These results suggest that Met-Met could be used as a partial source of Met to promote reproductive outcomes in Met-restricted pregnant mice, which might be mediated by promoting nutrient availability and activating AKT/mTOR-mediated signaling pathway.

Relative Efficacy of Checkpoint Inhibitors for Advanced NSCLC According to Programmed Death-Ligand-1 Expression: A Systematic Review and Network Meta-Analysis

Although currently available immune checkpoint inhibitors with similar but slightly different indications are recommended for patients with advanced non-small cell lung cancer (NSCLC), their effects by programmed death-ligand-1 (PD-L1) expression level are not yet known. This meta-analysis aims to assess the survival benefit and comparative efficacy of checkpoint inhibitors according to PD-L1 expression level: <1%, 1-49%, and ≥50%. We searched the MEDLINE, EMBASE, and Cochrane database through December 2017. A fixed-effect Bayesian network meta-analysis (NMA) was performed to estimate hazard ratios (HRs) for overall survival (OS) with 95% credible intervals (CrIs). Seven trials including 3688 patients were selected from among the 673 screened studies. Checkpoint inhibitor remarkably improved OS over chemotherapy in the PD-L1 ≥ 50% subgroup compared with the PD-L1 < 1% and PD-L1 1-49% subgroups. Atezolizumab, nivolumab, and nivolumab were the most effective agents for second- or later-line settings in the PD-L1 < 1%, PD-L1 1-49%, and PD-L1 ≥ 50% subgroups, respectively. PD-L1 expression ≥50% on tumor cells could be a reliable indicator that helps patient selection in view of cost-efficiency, and each checkpoint inhibitor reported to be the best agent by PD-L1 expression level could be carefully recommended in each PD-L1 expression subgroup.

Fetal and Maternal Innate Immunity Receptors Have Opposing Effects on the Severity of Experimental Malaria in Pregnancy: Beneficial Roles for Fetus-Derived Toll-Like Receptor 4 and Type I Interferon Receptor 1

Malaria in pregnancy (MiP) is a distinctive clinical form of Plasmodium infection and is a cause of placental insufficiency leading to poor pregnancy outcomes. Maternal innate immunity responses play a decisive role in the development of placental inflammation, but the action of fetus-derived factors in MiP outcomes has been overlooked. We investigated the role of the Tlr4 and Ifnar1 genes, taking advantage of heterogenic mating strategies to dissect the effects mediated by maternally and fetally derived Toll-like receptor 4 (TLR4) or type I interferon receptor 1 (IFNAR1). Using a mouse infection system displaying severe MiP outcomes, we found that the expressions of TLR4 and IFNAR1 in the maternal compartment take part in deleterious MiP outcomes, but their fetal counterparts patently counteract these effects. We uncovered that fetal TLR4 contributes to the in vitro uptake of infected erythrocytes by trophoblasts and to the innate immune response in the placenta, offering robust protection of fetus viability, but had no sensible impact on the placental parasite burden. In contrast, we observed that the expression of IFNAR1 in the fetal compartment was associated with a reduced placental parasite burden but had little beneficial effect on fetus outcomes. Furthermore, the downregulation of Ifnar1 expression in infected placentas and in trophoblasts exposed to infected erythrocytes indicated that the interferon-IFNAR1 pathway is involved in the trophoblast response to infection. This work unravels that maternal and fetal counterparts of innate immune pathways drive opposing responses in murine placental malaria and implicates the activation of innate receptors in fetal trophoblast cells in the control of placental infection and in the protection of the fetus.

Impaired placental autophagy in placental malaria

Background

Placental malaria is a major cause of low birthweight, principally due to impaired fetal growth. Intervillositis, a local inflammatory response to placental malaria, is central to the pathogenesis of poor fetal growth as it impairs transplacental amino acid transport. Given the link between inflammation and autophagy, we investigated whether placental malaria-associated intervillositis increased placental autophagy as a potential mechanism in impaired fetal growth.

Methods

We examined placental biopsies collected after delivery from uninfected women (n = 17) and from women with Plasmodium falciparum infection with (n = 14) and without (n = 7) intervillositis. Western blotting and immunofluorescence staining coupled with advanced image analysis were used to quantify the expression of autophagic markers (LC3-II, LC3-I, Rab7, ATG4B and p62) and the density of autophagosomes (LC3-positive puncta) and lysosomes (LAMP1-positive puncta).

Results

Placental malaria with intervillositis was associated with higher LC3-II:LC3-I ratio, suggesting increased autophagosome formation. We found higher density of autophagosomes and lysosomes in the syncytiotrophoblast of malaria-infected placentas with intervillositis. However, there appear to be no biologically relevant increase in LC3B/LAMP1 colocalization and expression of Rab7, a molecule involved in autophagosome/lysosome fusion, was lower in placental malaria with intervillositis, indicating a block in the later stage of autophagy. ATG4B and p62 expression showed no significant difference across histological groups suggesting normal autophagosome maturation and loading of cargo proteins into autophagosomes. The density of autophagosomes and lysosomes in the syncytiotrophoblast was negatively correlated with placental amino acid uptake.

Conclusions

Placental malaria-associated intervillositis is associated with dysregulated autophagy that may impair transplacental amino acid transport, possibly contributing to poor fetal growth.

Oxidative Stress: A Potential Therapeutic Target in Placental Malaria

Placental malaria, characterized by sequestration of Plasmodium falciparum in the maternal placental blood space and associated inflammatory damage, contributes to poor birth outcomes and ~200,000 infant deaths annually. Specific mechanisms that contribute to placental damage and dysfunction during malaria are not completely understood. To investigate a potential role for oxidative stress, antioxidant genes and markers for oxidative damage were assessed by quantitative PCR and immunohistochemistry in Plasmodium chabaudi AS-infected pregnant mice. Widespread evidence of lipid peroxidation was observed and was associated with higher antioxidant gene expression in conceptuses of infected mice. To assess the extent to which this oxidative damage might contribute to poor birth outcomes and be amenable to therapeutic intervention, infected pregnant mice were treated with N-acetylcysteine, a free radical scavenger, or tempol, an intracellular superoxide dismutase mimetic. The results show that mice treated with N-acetylcysteine experienced malaria induced-pregnancy loss at the same rate as control animals and failed to mitigate placental oxidative damage. In contrast, tempol-treated mice exhibited subtle improvement in embryo survival at gestation day 12. Although lipid peroxidation was not consistently reduced in the placentas of these mice, it was inversely related to embryo viability. Moreover, reduced IFN-γ and CCL2 plasma levels in treated mice were associated with midgestational embryo viability. Thus, although oxidative stress is remarkable in placental malaria and its mitigation by antioxidant therapy may improve pregnancy outcomes, the underlying mechanistic basis and potential therapeutic strategies require additional investigation.