Assay Development and Identification of the First Plasmodium falciparum 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase Inhibitors.

In the fight towards eradication of malaria, identifying compounds active against new drug targets constitutes a key approach. Plasmodium falciparum 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase (PfHPPK) has been advanced as a promising target, as being part of the parasite essential folate biosynthesis pathway while having no orthologue in the human genome. However, no drug discovery efforts have been reported on this enzyme. In this study, we conducted a three-step screening of our in-house antifolate library against PfHPPK using a newly designed PfHPPK-GFP protein construct. Combining virtual screening, differential scanning fluorimetry and enzymatic assay, we identified 14 compounds active against PfHPPK. Compounds' binding modes were investigated by molecular docking, suggesting competitive binding with the HMDP substrate. Cytotoxicity and in vitro ADME properties of hit compounds were also assessed, showing good metabolic stability and low toxicity. The most active compounds displayed low micromolar IC50 against drug-resistant parasites. The reported hit compounds constitute a good starting point for inhibitor development against PfHPPK, as an alternative approach to tackle the malaria parasite.

Clinical Course, Associated Factors, and Blood Pressure Profile of Delayed-Onset Postpartum Preeclampsia.

OBJECTIVE: To identify clinical risk factors associated with development of delayed-onset postpartum preeclampsia, and to characterize management and subsequent risk of cardiovascular disease. METHODS: This is a case-control study of women admitted to the hospital with delayed-onset postpartum preeclampsia (defined as a new diagnosis of preeclampsia presenting between 48 hours and 6 weeks postpartum) compared with women with full-term, uncomplicated pregnancies without a hypertensive diagnosis or diabetes. Included women delivered between January 2014 and June 2018 at a single tertiary care center. Women with an antenatal diagnosis of preeclampsia or chronic hypertension were excluded. Univariate analysis was used to identify risk factors associated with delayed-onset postpartum preeclampsia and to compare rates of hypertension and antihypertensive medication use, with follow-up beyond 3 months postpartum among a subset of women in the control group who were matched 2:1 with women in the case group. Multivariable logistic regression was performed and included covariates identified in a backward stepwise approach. RESULTS: Compared with women in the control group (n=26,936), women with delayed-onset postpartum preeclampsia (n=121) were significantly more likely to be of non-Hispanic black race (31.4% vs 18.0%), obese (39.7% vs 20.1%), and deliver by cesarean (40.5% vs 25.8%), all P<.01. For women diagnosed with delayed-onset postpartum preeclampsia, the median postpartum day of presentation was 7.0 (interquartile range 5.0-9.0), with 93.4% presenting secondary to symptoms, which was most commonly a headache. A majority (73.6%) underwent imaging studies, and 49.6% received intravenous antihypertensive agents. A total of 86 (71.0%) women with delayed-onset postpartum preeclampsia and 169 (72.8%) women in the control group had longer term information available, with a median follow-up time of 1.5 years (interquartile range 0.8-2.8). Delayed-onset postpartum preeclampsia was associated with higher blood pressures at 3 months postpartum or later (median systolic 130 mm Hg vs 112 mm Hg and median diastolic 80 mm Hg vs 70 mm Hg, P<.001). CONCLUSION: Delayed-onset postpartum preeclampsia is associated with variable management strategies. There is substantial overlap between the clinical risk factors for delayed-onset postpartum preeclampsia and antepartum preeclampsia. Our findings suggest that delayed-onset postpartum preeclampsia is also associated with an increased risk of progression to chronic hypertension.

Placental findings in non-hypertensive term pregnancies and association with future adverse pregnancy outcomes: a cohort study.

INTRODUCTION: Women with adverse pregnancy outcomes (APOs) have excess risk of later life cardiovascular disease (CVD) perhaps related to an underlying high-risk vascular phenotype. We sought to determine if placental evidence of maternal malperfusion in uncomplicated pregnancies is associated with an increased risk of APOs in subsequent pregnancies. METHODS: 536 women with more than one delivery and an initial uncomplicated pregnancy with placental pathology examination between 2008 and 2012 were included. APOs (small for gestational age, preterm delivery, or preeclampsia) were identified for each delivery. Multivariable log-binomial regression was used to estimate the risk of an APO in a subsequent pregnancy associated with MVM lesions in index pregnancy with adjustment for covariates. RESULTS: Placental pathology from the initial pregnancy was compared between women with no APO in any pregnancy (-APO/-APO; n = 403) and women with an initial uncomplicated pregnancy and a subsequent adverse outcome (-APO/+APO; n = 133). Women with MVM lesions had an increased risk of an APO in a subsequent pregnancy relative to women with no MVM lesions after adjusting for covariates (aOR = 1.61; 95%CI = 1.06-2.46). Decidual vasculopathy was found in 13/133 (9.8%) of -APO/+APO women compared with 16/403 (4.0%) of -APO/-APO women, with an adjusted odds ratio of 2.51 (95% CI = 1.31-4.80). DISCUSSION: MVM lesions found in placentas in uncomplicated pregnancies are associated with an increased risk of an adverse outcome in a subsequent pregnancy. Placental evidence of vascular malperfusion could offer a novel approach to risk stratification for subsequent pregnancy complications and perhaps future CVD.

Role of p90(RSK) in regulating the Crabtree effect: implications for cancer.

High glucose inhibits mitochondrial respiration, known as the 'Crabtree effect', in cancer cells and possibly other cell types. The upstream pathways regulating this phenomenon are poorly understood. In diabetes, where glucose levels are elevated, the p90(RSK) (p90 ribosomal S6 kinase) has received much attention as a potential upstream mediator of the effects of high glucose. Evidence is also emerging that p90(RSK) may play a role in cancer cell signalling, although the role of p90(RSK) in regulating cancer cell metabolism is unclear. In the present paper, we provide an overview of the Crabtree effect and its relationship to mitochondrial metabolism. Furthermore, preliminary data are presented suggesting a role for p90(RSK) and its upstream components, the ERK (extracellular-signal-regulated kinase) family of MAPKs (mitogen-activated protein kinases), in the Crabtree effect.

Mediterranean diet and cardioprotection: the role of nitrite, polyunsaturated fatty acids, and polyphenols.

The continually increasing rate of myocardial infarction (MI) in the Western world at least partly can be explained by a poor diet lacking in green vegetables, fruits, and fish and enriched in food that contains saturated fat. In contrast, a number of epidemiologic studies provide strong evidence highlighting the cardioprotective benefits of the Mediterranean diet enriched in green vegetables, fruits, fish, and grape wine. Regular consumption of these products leads to an accumulation of nitrate/nitrite/NO, polyunsaturated fatty acids (PUFA), and polyphenolic compounds, such as resveratrol, in the human body. Studies have confirmed that these constituents are bioactive exogenous mediators, which induce strong protection against MI. The aim of this review is to provide a critical, in-depth analysis of the cardioprotective pathways mediated by nitrite/NO, PUFA, and phenolic compounds of grape wines discovered in the recent years, including cross-talk between different mechanisms and compounds. Overall, these findings may facilitate the design and synthesis of novel therapeutic tools for the treatment of MI.