The association between acute fatty liver disease and nitric oxide during malaria in pregnancy.

BACKGROUND: Liver disease is a common feature of malaria in pregnancy, but its pathogenesis remains unclear. METHODS: To understand the pathogenesis of liver disease during malaria in pregnancy, comparative proteomic analysis of the liver in a mouse model of malaria in pregnancy was performed. RESULTS: Decreased levels of mitochondrial and peroxisomal proteins were observed in the livers of pregnant mice infected with the lethal rodent malaria parasite Plasmodium berghei strain NK65. By contrast, increased levels of perilipin-2, amyloid A-1, and interferon (IFN)-γ signalling pathway-related proteins were observed in the livers of infected pregnant mice, suggesting that IFN-γ signalling may contribute to the development of liver disease during malaria in pregnancy. IFN-γ signalling is a potential trigger of inducible nitric oxide synthase (iNOS) expression. Liver disease associated with microvesicular fatty infiltration and elevated liver enzymes in pregnant wild-type mice infected with malaria parasites was improved by iNOS deficiency. CONCLUSIONS: In this study, a causative role of iNOS in liver disease associated with microvesicular fatty infiltration during malaria in pregnancy was demonstrated. These findings provide important insight for understanding the role of iNOS-mediated metabolic responses and the pathogenesis of high-risk liver diseases in pregnancy, such as acute fatty liver.

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.

Gravidity-dependent associations between interferon response and birth weight in placental malaria.

BACKGROUND: Maternal malarial infection leads to poor perinatal outcomes, including low birth weight from preterm delivery and/or fetal growth restriction, particularly in primigravidas. In placental malaria, Plasmodium falciparum-infected red blood cells cause an inflammatory response that can interfere with maternal-fetal exchange, leading to poor growth. The type I interferon (IFN-I) pathway plays an immunomodulatory role in viral and bacterial infections, usually by suppressing inflammatory responses. However, its role in placental malaria is unknown. This study examines the cytokine responses in placental tissue from subsets of malaria-infected and uninfected women, and attempts to correlate them with particular birth outcomes. METHODS: 40 whole placental biopsy samples were obtained from pregnant women at least 16 years of age recruited to a larger prospective chemoprevention trial against malaria. These were patients at Tororo District Hospital in Uganda, an area of high malaria endemicity where approximately 40% of women have evidence of malaria infection at delivery. They were regularly followed at a local clinic and monitored for fever, with blood smears performed then and at time of delivery to diagnose malaria infection. Placenta biopsies were taken for histological diagnosis of placental malaria, as well as quantitative PCR analysis of genes in the IFN-I pathway (IFN-ß, IL-10 and MX-1). Parameters such as infant birth weight and gestational age were also recorded. RESULTS: Histological analysis revealed placental malaria in 18 samples, while 22 were found to be uninfected. RT-PCR analysis showed a four-fold increase in IFN-ß and IL-10 expression in multigravidas with placental malaria when compared to gravidity-matched, uninfected controls. This effect was not observed in primigravidas. Interestingly, linear regression analysis showed a positive association between IFN-ß levels and higher birth weights (ß = 101.2 g per log2-fold increase in IFN-ß expression, p = 0.042). This association was strongest in primigravidas with placental malaria (ß = 339.0, p = 0.006). CONCLUSIONS: These results demonstrate differential regulation of the IFN-I pathway in placental malaria according to gravidity, with the greatest anti-inflammatory response seen in multigravidas. The association between IFN-ß levels and higher birth weight also suggests a protective role for IFN-I against fetal growth restriction in placental malaria.

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

BACKGROUND: Placental Plasmodium falciparum malaria can trigger intervillositis, a local inflammatory response more strongly associated with low birthweight than placental malaria infection alone. Fetal growth (and therefore birthweight) is dependent on placental amino acid transport, which is impaired in placental malaria-associated intervillositis. Here, we tested the hypothesis that mechanistic target of rapamycin (mTOR) signaling, a pathway known to regulate amino acid transport, is inhibited in placental malaria-associated intervillositis, contributing to lower birthweight. METHODS: We determined the link between intervillositis, mTOR signaling activity, and amino acid uptake in tissue biopsies from both uninfected placentas and malaria-infected placentas with and without intervillositis, and in an in vitro model using primary human trophoblast (PHT) cells. RESULTS: We demonstrated that (1) placental mTOR activity is lower in cases of placental malaria with intervillositis, (2) placental mTOR activity is negatively correlated with the degree of inflammation, and (3) inhibition of placental mTOR activity is associated with reduced placental amino acid uptake and lower birthweight. In PHT cells, we showed that (1) inhibition of mTOR signaling is a mechanistic link between placental malaria-associated intervillositis and decreased amino acid uptake and (2) constitutive mTOR activation partially restores amino acid uptake. CONCLUSIONS: Our data support the concept that inhibition of placental mTOR signaling constitutes a mechanistic link between placental malaria-associated intervillositis and decreased amino acid uptake, which may contribute to lower birthweight. Restoring placental mTOR signaling in placental malaria may increase birthweight and improve neonatal survival, representing a new potential therapeutic approach.

Experimental Malaria in Pregnancy Induces Neurocognitive Injury in Uninfected Offspring via a C5a-C5a Receptor Dependent Pathway.

The in utero environment profoundly impacts childhood neurodevelopment and behaviour. A substantial proportion of pregnancies in Africa are at risk of malaria in pregnancy (MIP) however the impact of in utero exposure to MIP on fetal neurodevelopment is unknown. Complement activation, in particular C5a, may contribute to neuropathology and adverse outcomes during MIP. We used an experimental model of MIP and standardized neurocognitive testing, MRI, micro-CT and HPLC analysis of neurotransmitter levels, to test the hypothesis that in utero exposure to malaria alters neurodevelopment through a C5a-C5aR dependent pathway. We show that malaria-exposed offspring have persistent neurocognitive deficits in memory and affective-like behaviour compared to unexposed controls. These deficits were associated with reduced regional brain levels of major biogenic amines and BDNF that were rescued by disruption of C5a-C5aR signaling using genetic and functional approaches. Our results demonstrate that experimental MIP induces neurocognitive deficits in offspring and suggest novel targets for intervention.

Effect of pharmacogenetics on plasma lumefantrine pharmacokinetics and malaria treatment outcome in pregnant women.

BACKGROUND: Pregnancy has considerable effects on the pharmacokinetic properties of drugs used to treat uncomplicated Plasmodium falciparum malaria. The role of pharmacogenetic variation on anti-malarial drug disposition and efficacy during pregnancy is not well investigated. The study aimed to examine the effect of pharmacogenetics on lumefantrine (LF) pharmacokinetics and treatment outcome in pregnant women. METHODS: Pregnant women with uncomplicated falciparum malaria were enrolled and treated with artemether-lumefantrine (ALu) at Mkuranga and Kisarawe district hospitals in Coast Region of Tanzania. Day-7 LF plasma concentration and genotyping forCYP2B6 (c.516G>T, c.983T>C), CYP3A4*1B, CYP3A5 (*3, *6, *7) and ABCB1 c.4036A4G were determined. Blood smear for parasite quantification by microscopy, and dried blood spot for parasite screening and genotyping using qPCR and nested PCR were collected at enrolment up to day 28 to differentiate between reinfection from recrudescence. Treatment response was recorded following the WHO protocol. RESULTS: In total, 92 pregnant women in their second and third trimester were included in the study and 424 samples were screened for presence of P. falciparum. Parasites were detected during the follow up period in 11 (12%) women between day 7 and 28 after treatment and PCR genotyping confirmed recrudescent infection in 7 (63.3%) women. The remaining four (36.4%) pregnant women had reinfection: one on day 14 and three on day 28. The overall PCR-corrected treatment failure rate was 9.0% (95% CI 4.4-17.4). Day 7 LF concentration was not significantly influenced by CYP2B6, CYP3A4*1B and ABCB1 c.4036A>G genotypes. Significant associations between CYP3A5 genotype and day 7 plasma LF concentrations was found, being higher in carriers of CYP3A5 defective variant alleles than CYP3A5*1/*1 genotype. No significant influence of CYP2B6, CYP3A5 and ABCB1 c.4036A>Genotypes on malaria treatment outcome were observed. However, CYP3A4*1B did affect malaria treatment outcome in pregnant women followed up for 28 days (P = 0.018). CONCLUSIONS: Genetic variations in CYP3A4 and CYP3A5may influence LF pharmacokinetics and treatment outcome in pregnant women.

Synergistic effect of DDT and its metabolites in lipopolysaccharide-mediated TNF-α production is inhibited by progesterone in peripheral blood mononuclear cells.

Increased TNF-α levels have been associated with adverse pregnancy outcomes. Lipopolysaccharide (LPS), 1,1,1-trichloro-2,2-bis-(chlorophenyl)ethane (DDT), 1,1-bis-(chlorophenyl)-2,2-dichloroethene (DDE), and 1,1-dichloro-2,2-bis(chlorophenyl)ethane (DDD) induce TNF-α release in peripheral blood mononuclear cells (PBMC). Conversely, progesterone (P4) inhibits TNF-α secretion. Pregnant women in malaria endemic areas may be co-exposure to these compounds. Thus, this study was to investigate the synergistic effect of LPS and these pesticides in PBMC and to assess P4 influence on this synergy. Cultured PBMC were exposed to each pesticide in the presence of LPS, P4, or their combination. TNF-α was measured by ELISA. All pesticides enhanced TNF-α synthesis in PBMC. Co-exposure with LPS synergizes TNF-α production, which is blocked by progesterone. These results indicate that these organochlorines act synergistically with LPS to induce TNF-α secretion in PBMC. This effect is blocked by P4.

Molecular dissection of placental malaria protein VAR2CSA interaction with a chemo-enzymatically synthesized chondroitin sulfate library.

Placental malaria, a serious infection caused by the parasite Plasmodium falciparum, is characterized by the selective accumulation of infected erythrocytes (IEs) in the placentas of the pregnant women. Placental adherence is mediated by the malarial VAR2CSA protein, which interacts with chondroitin sulfate (CS) proteoglycans present in the placental tissue. CS is a linear acidic polysaccharide composed of repeating disaccharide units of D-glucuronic acid and N-acetyl-D-galactosamine that are modified by sulfate groups at different positions. Previous reports have shown that placental-adhering IEs were associated with an unusually low sulfated form of chondroitin sulfate A (CSA) and that a partially sulfated dodecasaccharide is the minimal motif for the interaction. However, the fine molecular structure of this CS chain remains unclear. In this study, we have characterized the CS chain that interacts with a recombinant minimal CS-binding region of VAR2CSA (rVAR2) using a CS library of various defined lengths and sulfate compositions. The CS library was chemo-enzymatically synthesized with bacterial chondroitin polymerase and recombinant CS sulfotransferases. We found that C-4 sulfation of the N-acetyl-D-galactosamine residue is critical for supporting rVAR2 binding, whereas no other sulfate modifications showed effects. Interaction of rVAR2 with CS is highly correlated with the degree of C-4 sulfation and CS chain length. We confirmed that the minimum structure binding to rVAR2 is a tri-sulfated CSA dodecasaccharide, and found that a highly sulfated CSA eicosasaccharide is a more potent inhibitor of rVAR2 binding than the dodecasaccharides. These results suggest that CSA derivatives may potentially serve as targets in therapeutic strategies against placental malaria.

Experimental Neospora Caninum Infection in Pregnant Dairy Heifers Raises Concentrations of Pregnancy-Associated Glycoproteins 1 and 2 in Foetal Fluids.

Plasma concentrations of PAG-1 are used for pregnancy diagnosis and as a marker of placental/foetal well-being, while those of PAG-2 may be an indicator of abortion risk in Neospora caninum-infected cows. Studies have shown that N. caninum infection modifies PAG-1 and PAG-2 patterns in maternal blood plasma. However, no prior work has examined the effects of N. caninum infection on concentrations of PAGs in foetal fluids. In this study, PAG-1, PAG-2 and pH levels were determined in the amniotic and allantoic fluids of foetuses collected at 152 days of gestation from control uninfected dams and from dams experimentally infected with N. caninum on Day 110 of gestation. Foetal fluids from infected foetuses had significantly higher PAG-2 concentrations (p = 0.026) and pH values (p = 0.02) than fluids from non-infected foetuses. In infected foetuses, significantly higher concentrations of PAG-1 (p < 0.001) and PAG-2 (p < 0.001) were detected in fluid samples showing antibodies against N. caninum than those without antibodies. Moreover, pH values were significantly higher (p = 0.011) in foetal fluid samples with antibodies than in samples from non-infected foetuses. In conclusion, this is the first report on the effect of N. caninum infection on PAG levels in foetal fluids. Our results indicate that following the experimental infection of dams with N. caninum on Day 110 of gestation, foetal fluids collected from the infected foetuses of these dams featured higher PAG-1 and PAG-2 levels and pH values than fluids from non-infected controls, provided that the samples tested showed the presence of antibodies. The clinical implications of these findings are that following infection with N. caninum, most cows will experience some level of placental damage and that this injury correlates with foetal fluid PAG levels and pH.

Plasmodium falciparum malaria elicits inflammatory responses that dysregulate placental amino acid transport.

Placental malaria (PM) can lead to poor neonatal outcomes, including low birthweight due to fetal growth restriction (FGR), especially when associated with local inflammation (intervillositis or IV). The pathogenesis of PM-associated FGR is largely unknown, but in idiopathic FGR, impaired transplacental amino acid transport, especially through the system A group of amino acid transporters, has been implicated. We hypothesized that PM-associated FGR could result from impairment of transplacental amino acid transport triggered by IV. In a cohort of Malawian women and their infants, the expression and activity of system A (measured by Na⁺-dependent ¹4C-MeAIB uptake) were reduced in PM, especially when associated with IV, compared to uninfected placentas. In an in vitro model of PM with IV, placental cells exposed to monocyte/infected erythrocytes conditioned medium showed decreased system A activity. Amino acid concentrations analyzed by reversed phase ultra performance liquid chromatography in paired maternal and cord plasmas revealed specific alterations of amino acid transport by PM, especially with IV. Overall, our data suggest that the fetoplacental unit responds to PM by altering its placental amino acid transport to maintain adequate fetal growth. However, IV more profoundly compromises placental amino acid transport function, leading to FGR. Our study offers the first pathogenetic explanation for FGR in PM.

Toxoplasma gondii isolate with genotype Chinese 1 triggers trophoblast apoptosis through oxidative stress and mitochondrial dysfunction in mice.

Congenital toxoplasmosis may result in abortion, severe mental retardation and neurologic damage in the offspring. Placental damage is considered as the key event in this disease. Here we show that maternal infection with Toxoplasma gondii Wh3 isolate of genotype Chinese 1, which is predominantly prevalent in China, induced trophoblast apoptosis of pregnant mouse. PCR array analysis of 84 key genes in the biogenesis and functions of mouse mitochondrion revealed that ten genes were up-regulated at least 2-fold in the Wh3 infection group, compared with those in the control. The elevated levels of reactive oxygen species (ROS), malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG), as well as the decreased glutathione (GSH), were observed in the infected mice. The mRNA levels of NADPH oxidase 1 and glutathione peroxidase 6 (GPx6) were significantly increased. The production of excessive ROS was NADPH oxidase-dependent, which contributed to mitochondrial structural damage and mitochondrial dysfunction in placentas, followed by the cleavage of caspase-9 and caspase-3, and finally resulted in apoptosis of trophoblasts. All the above-mentioned phenomena were inhibited by pretreatment with the antioxidant of N-acetylcysteine (NAC). Taken together, we concluded that Wh3 infection during pregnancy may contribute to trophoblast apoptosis by oxidative stress-induced mitochondrial dysfunction and activation of the downstream signaling pathway.

The correlation of Tim-3 and IFN-γ expressions in mice infected with Toxoplasma gondii during gestation.

The immunoinhibitory receptor T cell immunoglobulin domain and mucin domain-1 (Tim-1) and Tim-3 participate in the regulation of Th immune response as well as innate immunity. However, there is no report about the expression of Tim genes in Toxoplasma gondii-infected experimental models during pregnancy. In this study, Kunming outbred pregnant mice were infected with RH strain of T. gondii through vagina at days 10 to 16 of gestation, and the mRNA expressions of Tim-1, Tim-3, interleukin (IL)-4, and interferon (IFN)-γ in the placentas, uteri, and draining lumber aortic lymph nodes (LALNs) at day 18 of gestation were analyzed using quantitative real-time PCR (qRT-PCR). Compared with uninfected pregnant controls, significantly increased levels of IFN-γ and Tim-3 were detected in the placentas (P < 0.001), uteri (P = 0.003 and P = 0.017, respectively), and LALNs (P = 0.003 and P = 0.025, respectively) of T. gondii-infected mice; there were positive and significant correlations between Tim-3 and IFN-γ mRNA expression levels in the placentas (R(2) = 0.6331, P = 0.0011), uteri (R(2) = 0.5658, P = 0.003), and LALNs (R(2) = 0.5583, P = 0.0033) of infected mice. Tim-1 (P = 0.002) and IL-4 (P = 0.003) expressions were significantly increased in the placentas, but Tim-1 were significantly decreased in the uteri (P = 0.013) and LALNs (P < 0.001) of infected pregnant mice in comparison of uninfected pregnant controls. Our data suggested that Tim-3 may play a regulatory role in T. gondii-infected pregnant mouse model.

Low Fetal Weight is Directly Caused by Sequestration of Parasites and Indirectly by IL-17 and IL-10 Imbalance in the Placenta of Pregnant Mice with Malaria.

The sequestration of infected erythrocytes in the placenta can activate the syncytiotrophoblast to release cytokines that affect the micro-environment and influence the delivery of nutrients and oxygen to fetus. The high level of IL-10 has been reported in the intervillous space and could prevent the pathological effects. There is still no data of Th17 involvement in the pathogenesis of placental malaria. This study was conducted to reveal the influence of placental IL-17 and IL-10 levels on fetal weights in malaria placenta. Seventeen pregnant BALB/C mice were divided into control (8 pregnant mice) and treatment group (9 pregnant mice infected by Plasmodium berghei). Placental specimens stained with hematoxylin and eosin were examined to determine the level of cytoadherence by counting the infected erythrocytes in the intervillous space of placenta. Levels of IL-17 and IL-10 in the placenta were measured using ELISA. All fetuses were weighed by analytical balance. Statistical analysis using Structural Equation Modeling showed that cytoadherence caused an increased level of placental IL-17 and a decreased level of placental IL-10. Cytoadherence also caused low fetal weight. The increased level of placental IL-17 caused low fetal weight, and interestingly low fetal weight was caused by a decrease of placental IL-10. It can be concluded that low fetal weight in placental malaria is directly caused by sequestration of the parasites and indirectly by the local imbalance of IL-17 and IL-10 levels.

Insight into the pathogenesis of fetal growth restriction in placental malaria: decreased placental glucose transporter isoform 1 expression.

Placental malaria, especially when complicated with intervillositis, can cause fetal growth restriction. Transplacental glucose transport by glucose transporter isoform 1 (GLUT-1) on the syncytiotrophoblast microvillous and basal plasma membranes regulates fetal growth. We found that GLUT-1 expression in the microvillous plasma membrane of Plasmodium falciparum-negative placenta biopsy specimens was comparable to that in P. falciparum-positive placenta biopsy specimens with or without intervillositis, whereas GLUT-1 expression in the basal plasma membrane was lowest in P. falciparum-positive placenta biopsy specimens with intervillositis, compared with the other 2 specimen types (P ≤ .0016). GLUT-1 expression in the basal plasma membrane also correlated negatively with monocyte infiltrate density (r = -0.43; P = .003) and positively with birth weight (r = 0.28; P = .06). These findings suggest that intervillositis, more than placental malaria per se, might cause fetal growth restriction, through impaired transplacental glucose transport.

Malaria infection alters the expression of hepatobiliary and placental drug transporters in pregnant mice.

Preventing and treating malaria in pregnancy is a global health priority. However little is known regarding the impact of malaria infection on the maternal and fetal disposition of pharmaceuticals and other xenobiotics. Our objective was to characterize expression of key determinants of drug-disposition in maternal and fetal tissues in a validated murine model of experimental placental malaria. Balb/c mice were infected with Plasmodium berghei at mid gestation [gestational day (GD) 13] and maternal, placental, and fetal tissues were collected at GD19. Expression of key ABC drug transporters and Cyp3a11 was examined by quantitative polymerase chain reaction. Western blotting was used to examine the protein expression of multidrug resistance protein 1 (MDR1, ABCB1). Compared with controls, placental mRNA expression of Abcb1a, Abcb1b, Abcc1, Abcc2, Abcc3, and Abcg2 were significantly downregulated in the malaria-infected group (P < 0.05), as was placental MDR1 protein (P < 0.05). Significantly decreased hepatic expression of Abcc2, Abcg2, and Abcb11 and significantly increased expression of Abcb1b, Abcc1, and Abcc3 were seen in malaria-infected dams (P < 0.05) in comparison with uninfected controls. The expression of Abcb1a and Abcg2 was significantly decreased in fetal liver of infected dams, whereas levels of Abcb1b were increased (P < 0.05). Maternal and fetal hepatic expression of Cyp3a11 was significantly downregulated in the malaria group (P < 0.05). Together, malaria-induced alterations in the expression of transporters and drug-metabolizing enzymes in maternal and fetal tissues may alter the disposition of endogenous and therapeutic substrates, potentially impacting maternal and fetal outcomes.

Histopathologies, immunolocalization, and a glycan binding screen provide insights into Plasmodium falciparum interactions with the human placenta.

During pregnancy, Plasmodium falciparum-infected erythrocytes cytoadhere to the placenta. Infection is likely initiated at two sites where placental trophoblasts contact maternal blood: 1) via syncytiotrophoblast (STB), a multicellular transporting and biosynthetic layer that forms the surface of chorionic villi and lines the intervillous space, and 2) through invasive cytotrophoblasts, which line uterine vessels that divert blood to the placenta. Here, we investigated mechanisms of infected erythrocyte sequestration in relationship to the microanatomy of the maternal-fetal interface. Histological analyses revealed STB denudation in placental malaria, which brought the stromal cores of villi in direct contact with maternal blood. STB denudation was associated with hemozoin deposition (P = 0.01) and leukocyte infiltration (P = 0.001) and appeared to be a feature of chronic placental malaria. Immunolocalization of infected red blood cell receptors (CD36, ICAM1/CD54, and chondroitin sulfate A) in placentas from uncomplicated pregnancies showed that STB did not stain, while the underlying villous stroma was immunopositive. Invasive cytotrophoblasts expressed ICAM1. In malaria, STB denudation exposed CD36 and chondroitin sulfate A in the villous cores to maternal blood, and STB expressed ICAM1. Finally, we investigated infected erythrocyte adherence to novel receptors by screening an array of 377 glycans. Infected erythrocytes bound Lewis antigens that immunolocalized to STB. Our results suggest that P. falciparum interactions with STB-associated Lewis antigens could initiate placental malaria. Subsequent pathologies, which expose CD36, ICAM1, and chondroitin sulfate A, might propagate the infection.

Maternal protein deficiency during a gastrointestinal nematode infection alters developmental profile of lymphocyte populations and selected cytokines in neonatal mice.

Neonatal immune development begins in pregnancy and continues into lactation and may be affected by maternal diet. We investigated the possibility that maternal protein deficiency (PD) during a chronic gastrointestinal (GI) nematode infection could impair neonatal immune development. Beginning on d 14 of pregnancy, mice were fed protein-sufficient (PS; 24%) or protein-deficient (PD; 6%) isoenergetic diets and were infected weekly with either 0 (sham) or 100 Heligmosomoides bakeri larvae. Pups were killed on d 2, 7, 14, and d 21 and dams on d 20 of lactation. Lymphoid organs were weighed. Cytokine concentration in maternal and pup serum and in milk from pup stomachs and lymphoid cell populations in pup spleen and thymus were determined using luminex and flow cytometry, respectively. GI nematode infection increased Th2 cytokines (IL-4, IL-5, IL-13), IL-2, IL-10, and eotaxin in serum of dams whereas PD reduced IL-4 and IL-13. The lower IL-13 in PD dams was associated with increased fecal egg output and worm burdens. Maternal PD increased vascular endothelial growth factor in pup milk and eotaxin in pup serum. Maternal infection increased eotaxin in pup serum. Evidence of impaired neonatal immune development included reduced lymphoid organ mass in pups associated with both maternal infection and PD and increased percentage of T cells and T:B cell ratio in the spleen associated with maternal PD. Findings suggest that increases in specific proinflammatory cytokines as a result of the combination of infection and dietary PD in dams can impair splenic immune development in offspring.

Fetal Growth Retardation is Associated with High Apoptotic Cells and Low VEGF Expression in Placenta of Malarial Pregnant Mice.

Background: During pregnancy, pregnant women are susceptible to malaria, contributing significantly to maternal and infant mortality. Objective: This research was conducted to study the effect of Plasmodium berghei infection in pregnant mice on fetal growth retardation through placental cell apoptosis and the change of local vascularization. Methods: Eighteen pregnant Balb/c strain mice resulting from simultanously mating were divided into two groups those were nine pregnant mice used as non infected group and nine pregnant mice infected with Plasmodium berghei on day 9th post mating used as infected group respectively. On day 15th of post mating, all of the pregnant mice were killed. Fetal weights were measured using analytic balance. Apoptosis of placental cells and VEGF expression in the placental tissue were measured using immunohistochemistry. Results: Result showed that there was sequestration of parasite-infected red blood cells (PRBCs) in intervillous space. Statistical analysis showed that the fetal weights in infected pregnant mice group was significantly lower than non infected one (p = 0.01), and the placental cell apoptosis in placental tissue of infected pregnant mice was significantly higher than the non infected one (p=0.00).There was also a significant difference on VEGF expression between infected group and non infected group (p= 0,00). Conclusion: Plasmodium berghei infection in pregnant Balb/c mice can cause fetal growth retardation due to high of placental cell apoptosis and low VEGF expression.

The chondroitin sulfate A-binding site of the VAR2CSA protein involves multiple N-terminal domains.

Malaria during pregnancy is a major health problem for African women. The disease is caused by Plasmodium falciparum malaria parasites, which accumulate in the placenta by adhering to chondroitin sulfate A (CSA). The interaction between infected erythrocytes and the placental receptor is mediated by a parasite expressed protein named VAR2CSA. A vaccine protecting pregnant women against placental malaria should induce antibodies inhibiting the interaction between VAR2CSA and CSA. Much effort has been put into defining the part of the 350 kDa VAR2CSA protein that is responsible for binding. It has been shown that full-length recombinant VAR2CSA binds specifically to CSA with high affinity, however to date no sub-fragment of VAR2CSA has been shown to interact with CSA with similar affinity or specificity. In this study, we used a biosensor technology to examine the binding properties of a panel of truncated VAR2CSA proteins. The experiments indicate that the core of the CSA-binding site is situated in three domains, DBL2X-CIDR(PAM) and a flanking domain, located in the N-terminal part of VAR2CSA. Furthermore, recombinant VAR2CSA subfragments containing this region elicit antibodies with high parasite adhesion blocking activity in animal immunization experiments.

Population pharmacokinetics of dihydroartemisinin and piperaquine in pregnant and nonpregnant women with uncomplicated malaria.

Pregnant women are particularly vulnerable to malaria. The pharmacokinetic properties of antimalarial drugs are often affected by pregnancy, resulting in lower drug concentrations and a consequently higher risk of treatment failure. The objective of this study was to evaluate the population pharmacokinetic properties of piperaquine and dihydroartemisinin in pregnant and nonpregnant women with uncomplicated malaria. Twenty-four pregnant and 24 matched nonpregnant women on the Thai-Myanmar boarder were treated with a standard fixed oral 3-day treatment, and venous plasma concentrations of both drugs were measured frequently for pharmacokinetic evaluation. Population pharmacokinetics were evaluated with nonlinear mixed-effects modeling. The main pharmacokinetic finding was an unaltered total exposure to piperaquine but reduced exposure to dihydroartemisinin in pregnant compared to nonpregnant women with uncomplicated malaria. Piperaquine was best described by a three-compartment disposition model with a 45% higher elimination clearance and a 47% increase in relative bioavailability in pregnant women compared with nonpregnant women. The resulting net effect of pregnancy was an unaltered total exposure to piperaquine but a shorter terminal elimination half-life. Dihydroartemisinin was best described by a one-compartment disposition model with a 38% lower relative bioavailability in pregnant women than nonpregnant women. The resulting net effect of pregnancy was a decreased total exposure to dihydroartemisinin. The shorter terminal elimination half-life of piperaquine and lower exposure to dihydroartemisinin will shorten the posttreatment prophylactic effect and might affect cure rates. The clinical impact of these pharmacokinetic findings in pregnant women with uncomplicated malaria needs to be evaluated in larger series.