MZe786, a hydrogen sulfide-releasing aspirin prevents preeclampsia in heme oxygenase-1 haplodeficient pregnancy under high soluble flt-1 environment

Region-Specific and Pregnancy-Enhanced Vasodilator Effects of Hydrogen Sulfide

Hydrogen sulfide (H2S) is a cardiovascular signaling molecule that causes vasodilation in vascular smooth muscle cells, but its mechanism is unclear. We examined how H2S affects mesenteric and uterine arteries without endothelium in nonpregnant and pregnant rats and the underlying mechanisms. H2S donors GYY4137 and NaHS relaxed uterine arteries more than mesenteric arteries in both pregnant and nonpregnant rats. GYY4137 and NaHS caused greater relaxation in the uterine artery of pregnant versus nonpregnant rats. High extracellular K+ abolished NaHS relaxation in pregnant uterine arteries, indicating potassium channel involvement. NaHS relaxation was unaffected by voltage-gated potassium channel blockers, reduced by ATP-sensitive potassium channel blockers, and abolished by calcium-activated potassium (BKCa) channel blockers. Thiol-reductant dithiothreitol also prevented NaHS relaxation. Thus, H2S has region-specific and pregnancy-enhanced vasodilator effects in the uterine arteries, mainly mediated by BKCa channels and sulfhydration.

Advances of H2S in Regulating Neurodegenerative Diseases by Preserving Mitochondria Function

Neurotoxicity is induced by different toxic substances, including environmental chemicals, drugs, and pathogenic toxins, resulting in oxidative damage and neurodegeneration in mammals. The nervous system is extremely vulnerable to oxidative stress because of its high oxygen demand. Mitochondria are the main source of ATP production in the brain neuron, and oxidative stress-caused mitochondrial dysfunction is implicated in neurodegenerative diseases. H2S was initially identified as a toxic gas; however, more recently, it has been recognized as a neuromodulator as well as a neuroprotectant. Specifically, it modulates mitochondrial activity, and H2S oxidation in mitochondria produces various reactive sulfur species, thus modifying proteins through sulfhydration. This review focused on highlighting the neuron modulation role of H2S in regulating neurodegenerative diseases through anti-oxidative, anti-inflammatory, anti-apoptotic and S-sulfhydration, and emphasized the importance of H2S as a therapeutic molecule for neurological diseases.

Novel therapeutic and diagnostic approaches for preeclampsia

PURPOSE OF REVIEW

This review will summarize recent findings relating to the diagnostic approach to preeclampsia and current avenues of research aimed at modifying the underlying disease process.

RECENT FINDINGS

Growing international consensus supports a broad preeclampsia definition that incorporates maternal end-organ and uteroplacental dysfunction. Recent evidence demonstrates that this definition better identifies women and babies at risk of adverse outcomes compared to the traditional definition of hypertension and proteinuria. Multiple studies have demonstrated the usefulness and cost-effectiveness of angiogenic biomarkers such as soluble fms-like tyrosine kinase-1 and placental growth factor as a clinical adjunct to diagnose and predict severity of preeclampsia associated outcomes. Current novel therapeutic approaches to preeclampsia target pathogenic pathways (e.g. antiangiogenesis) or downstream effects such as oxidative stress and nitric oxide. Recent findings relating to these promising candidates are discussed. Multicenter clinical trials are needed to evaluate their effectiveness and ability to improve fetal and maternal outcomes.

SUMMARY

We provide an updated framework of the current approaches to define and diagnose preeclampsia. Disease modifying therapies (in particular, targeting the angiogenic pathway) are being developed for the first time and promise to revolutionize the way we manage preeclampsia.

Statins in pre-eclampsia or fetal growth restriction: A systematic review and meta-analysis on maternal blood pressure and fetal growth across species

BACKGROUND

Several human randomised controlled trials (RCTs) are investigating the effects of statins on pre-eclampsia (PE) and fetal growth restriction (FGR). This cross-species meta-analysis summarises the preclinical evidence of statin use for PE and FGR.

OBJECTIVES

Evaluate the effects of statins on maternal blood pressure (MBP) and birthweight (BW) in pregnancies complicated by PE or FGR.

SEARCH STRATEGY

PubMed and Embase.com were searched on 10 May 2022 using 'statins' and 'pregnancy'.

SELECTION CRITERIA

We included RCTs and cohorts with matched control groups as well as animal studies.

DATA COLLECTION AND ANALYSIS

The main outcomes were MBP in mmHg and BW in grams. The standardised mean difference (SMD) with a 95% confidence interval (CI) was calculated. Subgroup analyses on species, statin, dose, timing and route of administration were performed if subgroups included at least three studies.

MAIN RESULTS

Our data included one human and 12 animal studies. Prenatal administration of statins significantly reduced MBP during pregnancy (SMD  -2.49 mmHg [95% CI -4.26 to -0.71], p = 0.01). There was no significant effect of statins on BW (SMD 0.69 [95% CI -0.65 to 2.03], p = 0.28). Our subgroup analyses showed no effect on MBP of different doses, species or route of administration.

CONCLUSIONS

Our cross-species meta-analyses demonstrate that statins only reduce maternal blood pressure in rodent pregnancies complicated by pre-eclampsia or fetal growth restriction and have no effect on birthweight across species. The broad confidence intervals, inconsistent direction of the observed effects across the studies and large risk of bias lead us to conclude that a solid base for further human RCTs is lacking.

Pravastatin and placental insufficiency associated disorders: A systematic review and meta-analysis

Background: Uteroplacental insufficiency associated disorders, such as preeclampsia, fetal growth restriction and obstetrical antiphospholipid syndrome, share pathophysiology and risk factors with cardiovascular diseases treated with statins. Objective: To evaluate pregnancy outcomes among women with uteroplacental insufficiency disorders who were treated with statins. Search Strategy: Electronic databases were searched from inception to January 2022 Selection Criteria: Cohort studies and randomized controlled trials. Data collection and analysis: Pooled odds ratios were calculated using a random-effects model; meta-regression was utilized when applicable. Main Results: The analysis included ten studies describing 1,391 women with uteroplacental insufficiency disorders: 703 treated with pravastatin and 688 not treated with statins. Women treated with pravastatin demonstrated significant prolongation of pregnancy (mean difference 0.44 weeks, 95%CI:0.01-0.87, p = 0.04, I2 = 96%) and less neonatal intensive care unit admissions (OR = 0.42, 95%CI: 0.23-0.75, p = 0.004, I2 = 25%). In subgroup analysis, prolongation of pregnancy from study entry to delivery was statistically significant in cohort studies (mean difference 8.93 weeks, 95%CI:4.22-13.95, p = 0.00) but not in randomized control studies. Trends were observed toward a decrease in preeclampsia diagnoses (OR = 0.54, 95%CI:0.27-1.09, p = 0.09, I = 44%), perinatal death (OR = 0.32, 95%CI:0.09-1.13, p = 0.08, I2 = 54%) and an increase in birth weight (mean difference = 102 g, 95%CI: -14-212, p = 0.08, I2 = 96%). A meta-regression analysis demonstrated an association between earlier gestational age at initiation of treatment and a lower risk of preeclampsia development (R2 = 1). Conclusion: Pravastatin treatment prolonged pregnancy duration and improved associated obstetrical outcomes in pregnancies complicated with uteroplacental insufficiency disorders in cohort studies. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/ identifier CRD42020165804 17/2/2020.

Hydrogen sulfide against preeclampsia exposure-induced oxidative mitochondrial damage in HTR-8/SVneo cells

Extravillous trophoblast invasion disorder caused by oxidative stress is involved in the pathogenesis of preeclampsia (PE). In order to identify whether hydrogen sulfide (H2S) can prevent oxidative stress injury in extravillous trophoblasts. HTR-8/SVneo cells were detected by H2S inhibiting H2O2 induced oxidative mitochondrial damage. Reactive oxygen species (ROS) were detected, as well as malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD). JC-1 detected the potential of the mitochondrial membrane in this experiment. Then to detect the expression level of the apoptosis-inducing protein B-cell lymphoma-2 (Bcl-2) associated X protein (Bax), caspase 3, p53, p-p53, the apoptosis-inhibiting protein Bcl-2, PRAP, and the mitochondria fission protein Drp1, p-Drp1. CCK-8 assay, it was demonstrated that cell proliferation in the NaHS group was significantly higher than that in the Mod group, indicating that H2S may induce cell proliferation. Transwell assay elucidated that cell invasion in the NaHS group was recovered compared to the Mod group. ROS concentration no matter in cells or mitochondria was decreased by NaHS, which we could get from the comparison between the Mod group, PAG group, and NaHS group. The concentration of MDA was significantly lower in the NaHS group, and the concentration of SOD was extremely high in the NaHS group. Utilized JC-1 to detect mitochondrial membrane potential and found that cells from the NaHS group had a stable potential while cells from the Mod group and PAG group partly lost their potential, which could demonstrate that NaHS could maintain mitochondrial membrane potential. The western blot results revealed that p-Drp1 had a significant decline in the NaHS group, which means mitochondria fission was decreased in the NaHS group. The expression level of Bax and caspase 3 was significantly lower than in the Mod group and PAG group, and the expression level of Bcl-and PRAP was significantly higher in the NaHS group. That could prove that NaHS protect HTR-8/SVneo cell by inhibiting cell apoptosis. These promising results show that H2S elicits its effects on cell apoptosis by decreasing ROS concentration, maintaining mitochondrial membrane stability, and promoting apoptosis-inhibiting protein expression in cells.

Sodium Thiosulphate-Loaded Liposomes Control Hydrogen Sulphide Release and Retain Its Biological Properties in Hypoxia-like Environment

Hypoxia, or insufficient oxygen availability is a common feature in the development of a myriad of cardiovascular-related conditions including ischemic disease. Hydrogen sulphide (H2S) donors, such as sodium thiosulphate (STS), are known for their cardioprotective properties. However, H2S due to its gaseous nature, is released and cleared rapidly, limiting its potential translation to clinical settings. For the first time, we developed and characterised liposome formulations encapsulating STS and explored their potential for modulating STS uptake, H2S release and the ability to retain pro-angiogenic and biological signals in a hypoxia-like environment mirroring oxygen insufficiency in vitro. Liposomes were prepared by varying lipid ratios and characterised for size, polydispersity and charge. STS liposomal encapsulation was confirmed by HPLC-UV detection and STS uptake and H2S release was assessed in vitro. To mimic hypoxia, cobalt chloride (CoCl2) was administered in conjunction with formulated and non-formulated STS, to explore pro-angiogenic and metabolic signals. Optimised liposomal formulation observed a liposome diameter of 146.42 ± 7.34 nm, a polydispersity of 0.22 ± 0.19, and charge of 3.02 ± 1.44 mV, resulting in 25% STS encapsulation. Maximum STS uptake (76.96 ± 3.08%) from liposome encapsulated STS was determined at 24 h. Co-exposure with CoCl2 and liposome encapsulated STS resulted in increased vascular endothelial growth factor mRNA as well as protein expression, enhanced wound closure and increased capillary-like formation. Finally, liposomal STS reversed metabolic switch induced by hypoxia by enhancing mitochondrial bioenergetics. These novel findings provide evidence of a feasible controlled-delivery system for STS, thus H2S, using liposome-based nanoparticles. Likewise, data suggests that in scenarios of hypoxia, liposomal STS is a good therapeutic candidate to sustain pro-angiogenic signals and retain metabolic functions that might be impaired by limited oxygen and nutrient availability.

Emerging pharmacologic interventions for pre-eclampsia treatment

INTRODUCTION

Pre-eclampsia is a serious pregnancy complication and a major global concern for the mortality of both mother and fetus. Existing symptomatic treatments do not delay disease progression; thus, timely delivery of the baby is the most effective measure. However, the risk of various maternal and fetal injuries remains.

AREAS COVERED

In this review, we summarize the potential strategies for pharmacologic interventions in pre-eclamptic therapy. Specifically, we discuss the pathophysiological process of various effective candidate therapeutics that act on potential pathways and molecular targets to inhibit key stages of the disease. We refer to this pathogenesis-focused drug discovery model as a pathogenesis-target-drug (P-T-D) strategy. Finally, we discuss the introduction of nanotechnologies to improve the safety and efficacy of therapeutics via their specific placental targeting ability and placental retention effects.

EXPERT OPINION

Despite the active development of novel pharmacological treatments based on our current knowledge of pre-eclamptic pathogenesis, investigations are still in the early phase. Thus, further exploration of the pathological mechanisms, integrated with the P-T-D strategy and novel nanosystems, could encourage the development of more effective and safer strategies. Such advances could lead to a shift from expectant management to mechanistic-based therapy for pre-eclampsia.

Progress and perspective on hydrogen sulfide donors and their biomedical applications

Following the discovery of nitric oxide (NO) and carbon monoxide (CO), hydrogen sulfide (H₂ S) has been identified as the third gasotransmitter in humans. Increasing evidence have shown that H₂ S is of preventive or therapeutic effects on diverse pathological complications. As a consequence, it is of great significance to develop suitable approaches of H₂ S-based therapeutics for biomedical applications. H₂ S-releasing agents (H₂ S donors) play important roles in exploring and understanding the physiological functions of H₂ S. More importantly, accumulating studies have validated the theranostic potential of H₂ S donors in extensive repertoires of in vitro and in vivo disease models. Thus, it is imperative to summarize and update the literatures in this field. In this review, first, the background of H₂ S on its chemical and biological aspects is concisely introduced. Second, the studies regarding the H₂ S-releasing compounds are categorized and described, and accordingly, their H₂ S-donating mechanisms, biological applications, and therapeutic values are also comprehensively delineated and discussed. Necessary comparisons between related H₂ S donors are presented, and the drawbacks of many typical H₂ S donors are analyzed and revealed. Finally, several critical challenges encountered in the development of multifunctional H₂ S donors are discussed, and the direction of their future development as well as their biomedical applications is proposed. We expect that this review will reach extensive audiences across multiple disciplines and promote the innovation of H₂ S biomedicine.

The impact of COVID-19 on pregnancy and therapeutic drug development

Emerging data show that pregnant women with COVID-19 are at significantly higher risk of severe outcomes compared with non-pregnant women of similar age. This review discusses the invaluable insight revealed from vaccine clinical trials in women who were vaccinated and inadvertently became pregnant during the trial period. It further explores a number of clinical avenues in their management and proposes a drug development strategy in line with clinical trials for vaccines and drug treatments for the drug development community. Little is known of the long-term effects of COVID-19 on the mother and the baby. Our hypothesis that COVID-19 predisposes pregnant women to pre-eclampsia or hypertensive disorders during pregnancy is supported by a clinical study, and this may also adversely impact a woman's cardiovascular disease risk later in life. It may also increase a woman's risk of pre-eclampsia in subsequent pregnancy. This is an ever-evolving landscape, and early knowledge for healthcare providers and drug innovators is offered to ensure benefits outweigh the risks. COVID-19 mRNA vaccines appear to generate robust humoral immunity in pregnant and lactating women. This novel approach to vaccination also offers new ways to therapeutically tackle disorders of many unmet medical needs. LINKED ARTICLES: This article is part of a themed issue on The second wave: are we any closer to efficacious pharmacotherapy for COVID 19? (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.10/issuetoc.

H2S Donors and Their Use in Medicinal Chemistry

Hydrogen sulfide (H2S) is a ubiquitous gaseous signaling molecule that has an important role in many physiological and pathological processes in mammalian tissues, with the same importance as two others endogenous gasotransmitters such as NO (nitric oxide) and CO (carbon monoxide). Endogenous H2S is involved in a broad gamut of processes in mammalian tissues including inflammation, vascular tone, hypertension, gastric mucosal integrity, neuromodulation, and defense mechanisms against viral infections as well as SARS-CoV-2 infection. These results suggest that the modulation of H2S levels has a potential therapeutic value. Consequently, synthetic H2S-releasing agents represent not only important research tools, but also potent therapeutic agents. This review has been designed in order to summarize the currently available H2S donors; furthermore, herein we discuss their preparation, the H2S-releasing mechanisms, and their -biological applications.

Hydrogen sulfide releasing molecule MZe786 inhibits soluble Flt-1 and prevents preeclampsia in a refined RUPP mouse model

An imbalance in angiogenic growth factors and poor utero-placental perfusion are strongly associated with preeclampsia. The reduced utero-placental perfusion (RUPP) model that mimics insufficient placental perfusion is used to study preeclampsia. The aim of this study was to develop a refined RUPP model in C57Bl/6 J mice to test the efficacy of MZe786 as a potential inhibitor of soluble Flt-1 for preeclampsia therapy. Murine RUPP (mRUPP) was induced through bilateral ligation of the ovarian arteries at E11.5 that resulted in typical preeclampsia symptoms including increase in mean arterial pressure (MAP), kidney injury and elevated soluble Flt-1 (sFlt-1) levels in the maternal plasma and amniotic fluid. The murine RUPP kidneys showed tubular and glomerular damage along with increased oxidative stress characterised by increased nitrotyrosine staining. The mRUPP displayed abnormal placental vascular histology, reduced expression of placental cystathionine γ-lyase (CSE), the hydrogen sulfide (H₂S) producing enzyme, and resulted in adverse fetal outcomes (FGR). Importantly, oral administration of hydrogen sulfide (H₂S)-releasing compound MZe786 from E11.5 to E17.5 successfully prevented the development of preeclampsia. Specifically, MZe786 treatment reduced maternal MAP and kidney nitrotyrosine staining and improved fetal outcome. The circulation levels of sFlt-1 were dramatically decreased in MZe786 treated animals implying that H₂S released from MZe786 offered protection by inhibiting sFlt-1 levels. MZe786 prevent preeclampsia and warrant a rapid move to randomised control clinical trial.

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Refined mouse reduced uterine perfusion pressure (mRUPP) model exhibits preeclampsia symptoms.

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Mouse RUPP induces maternal hypertension, kidney injury, elevates circulating sFlt-1 levels and promotes nitrosative stress.

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Mouse RUPP reduces expression of the protective enzyme, placental cystathionine γ-lyase and causes poor fetal outcome.

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H₂S releasing aspirin, MZe786, acts as an inhibitor of sFlt-1 to successfully prevent preeclampsia and improve fetal outcome.

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MZe786 is a novel drug with therapeutic potential to prevent preeclampsia.