Developmental toxicity of the angiotensin II type 1 receptor antagonists during human pregnancy: a report of 10 cases

To Explore the Putative Molecular Targets of Diabetic Nephropathy and their Inhibition Utilizing Potential Phytocompounds

BACKGROUND

This review critically addresses the putative molecular targets of Diabetic Nephropathy (DN) and screens effective phytocompounds that can be therapeutically beneficial, and highlights their mechanistic modalities of action.

INTRODUCTION

DN has become one of the most prevalent complications of clinical hyperglycemia, with individual-specific variations in the disease spectrum that leads to fatal consequences. Diverse etiologies involving oxidative and nitrosative stress, activation of polyol pathway, inflammasome formation, Extracellular Matrix (ECM) modifications, fibrosis, and change in dynamics of podocyte functional and mesangial cell proliferation adds up to the clinical complexity of DN. Current synthetic therapeutics lacks target-specific approach, and is associated with the development of inevitable residual toxicity and drug resistance. Phytocompounds provides a vast diversity of novel compounds that can become an alternative therapeutic approach to combat the DN.

METHODS

Relevant publications were searched and screened from research databases like GOOGLE SCHOLAR, PUBMED and SCISEARCH. Out of 4895 publications, the most relevant publications were selected and included in this article.

RESULT

This study critically reviews over 60 most promising phytochemical and provides with their molecular targets, that can be of pharmacological significance in context to current treatment and concomitant research in DN.

CONCLUSION

This review highlights those most promising phytocompounds that have the potential of becoming new safer naturally-sourced therapeutic candidates and demands further attention at clinical level.

Candesartan Does Not Activate PPARγ and Its Target Genes in Early Gestation Trophoblasts

Angiotensin II receptor 1 blockers are commonly used to treat hypertension in women of childbearing age. While the fetotoxic effects of these drugs in the second and third trimesters of pregnancy are well documented, their possible impacts on placenta development in early gestation are unknown. Candesartan, a member of this group, also acts as a peroxisome proliferator-activated receptor gamma (PPARγ) agonist, a key regulator shown to be important for placental development. We have previously shown that trophoblasts do not express the candesartan target-receptor angiotensin II type 1 receptor AGTR1. This study investigated the possible role of candesartan on trophoblastic PPARγ and its hallmark target genes in early gestation. Candesartan did not affect the PPARγ protein expression or nuclear translocation of PPARγ. To mimic extravillous trophoblasts (EVTs) and cytotrophoblast/syncytiotrophoblast (CTB/SCT) responses to candesartan, we used trophoblast cell models BeWo (for CTB/SCT) and SGHPL-4 (EVT) cells as well as placental explants. In vitro, the RT-qPCR analysis showed no effect of candesartan treatment on PPARγ target genes in BeWo or SGHPL-4 cells. Treatment with positive control rosiglitazone, another PPARγ agonist, led to decreased expressions of LEP and PPARG1 in BeWo cells and an increased expression of PPARG1 in SGHPL-4 cells. Our previous data showed early gestation-placental AGTR1 expression in fetal myofibroblasts only. In a CAM assay, AGTR1 was stimulated with angiotensin II and showed increased on-plant vessel outgrowth. These results suggest candesartan does not negatively affect PPARγ or its target genes in human trophoblasts. More likely, candesartan from maternal serum may first act on fetal-placental AGTR1 and influence angiogenesis in the placenta, warranting further research.

A case of a pregnant woman with primary aldosteronism and superimposed preeclampsia treated with esaxerenone

During pregnancy, there is no established treatment for idiopathic hyperaldosteronism (IHA), the most common form of primary aldosteronism (PA) due to bilateral adrenal hyperplasia. Here, we report the case of a pregnant patient with IHA who was successfully treated with esaxerenone, a non-steroidal mineralocorticoid receptor (MR) antagonist. A 39-year-old woman, was diagnosed with IHA and commenced on nifedipine 20 mg daily because she desired to be pregnant. After one year, she became pregnant. Her blood pressure was well controlled until 34 weeks of gestation when her home blood pressure became elevated up to 140/90 mmHg. Although the dose of nifedipine was increased to 80 mg daily, her blood pressure increased to 151/97 mmHg and urinary test showed proteinuria of 2+ in 35 weeks of gestation. She was diagnosed with superimposed preeclampsia (SPE) and additionally treated with esaxerenone. Her blood pressure decreased to 120-140/98-100 mmHg and the proteinuria improved to +/-. A successful cesarean section at 37 weeks resulted in the delivery of a healthy baby boy. Her blood pressure was well controlled although esaxerenone was discontinued 2 weeks after the delivery. This is the first case of a pregnant woman who was safely treated with esaxerenone despite being a female at advanced maternal age who had been diagnosed with IHA and developed SPE. Further studies are needed to investigate the efficacy and safety of non-steroidal selective MR antagonist in similar pregnant patients with IHA, to establish better treatment strategy for these patients.

Immunomodulatory Activity of the Most Commonly Used Antihypertensive Drugs-Angiotensin Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers

This review article is focused on antihypertensive drugs, namely angiotensin converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB), and their immunomodulatory properties reported in hypertensive patients as well as in experimental settings involving studies on animal models and cell lines. The immune regulatory action of ACEI and ARB is mainly connected with the inhibition of proinflammatory cytokine secretion, diminished expression of adhesion molecules, and normalization of CRP concentration in the blood plasma. The topic has significant importance in future medical practice in the therapy of patients with comorbidities with underlying chronic inflammatory responses. Thus, this additional effect of immune regulatory action of ACEI and ARB may also benefit the treatment of patients with metabolic syndrome, allergies, or autoimmune disorders.

Reporting of offspring data in diabetes, HIV infection and hypertension trials during pregnancy: a systematic review

BACKGROUND

Clinical trials are conducted during pregnancy to evaluate benefits and risks of medicines for mother and child. The safety of maternal treatments is a key issue for healthcare professionals and parents.

OBJECTIVE

To analyse offspring data reported in clinical trials in pregnant women with diabetes, HIV infection or hypertension (three of the most common diseases in women of childbearing potential) and either treated prior to pregnancy for these chronic diseases or diagnosed and treated during pregnancy.

METHODS

PubMed and Embase (1 January 1997 to 31 December 2017) were searched for drug trials in pregnant women with diabetes, HIV infection or hypertension. Titles and abstracts were screened, followed by a full-text review of eligible articles. Inclusion criteria were interventional clinical trials in pregnant women treated with medication and full text in English. Trial characteristics, maternal and offspring data were extracted. Data were summarised by disease and study. Twelve key items were considered for the offspring.

RESULTS

Overall, 196 articles reporting 132 clinical trials (diabetes n=55; HIV n=59; hypertension n=18) were included. Key offspring data were frequently not reported, for example, number of births (diabetes: 22/55, 40%; HIV: 14/59, 24%; hypertension: 10/18, 56%). Congenital malformations were often not reported with sufficient detail (diabetes: 40/55, 73%; HIV: 39/59, 66%; hypertension: 17/18, 94%). Similar observations were made for other key items (eg, fetal losses, neonatal deaths).

CONCLUSION

Under-reporting of key data for the offspring was frequent in publications of clinical trials in pregnant women with diabetes, HIV infection or hypertension making the assessment of the benefit-risk ratio of treatment options during pregnancy difficult.

TRIAL REGISTRATION NUMBER

CRD42017057024.

Pediatric and Adolescent Headache

PURPOSE OF REVIEW

This article provides the practicing neurologist with a comprehensive, evidence-based approach to the diagnosis and management of headache in children and adolescents, with a focus on migraine.

RECENT FINDINGS

Four triptans are now labeled by the US Food and Drug Administration (FDA) for acute migraine treatment in adolescents, and rizatriptan is labeled for use in children age 6 and older. For preventive migraine treatment, the Childhood and Adolescent Migraine Prevention trial demonstrated that approximately 60% of children and adolescents with migraine will improve with a three-pronged treatment approach that includes: (1) lifestyle management counseling (on sleep, exercise, hydration, caffeine, and avoidance of meal skipping); (2) optimally dosed acute therapy, specifically nonsteroidal anti-inflammatory drugs and triptans; and (3) a preventive treatment that has some evidence for efficacy. For the remaining 40% of children and adolescents, and for those who would not have qualified for the Childhood and Adolescent Migraine Prevention trial because of having continuous headache or medication-overuse headache, the clinician's judgment remains the best guide to preventive therapy selection.

SUMMARY

Randomized placebo-controlled trials have been conducted to guide first-line acute and preventive migraine treatments in children and adolescents. Future research is needed to guide treatment for those with more refractory migraine, as well as for children and adolescents who have other primary headache disorders.

Prenatal hypocalvaria after prolonged intrauterine exposure to angiotensin II receptor antagonists

We report a case of prenatal exposure to angiotensin II receptor antagonists (ARA II) from the beginning of pregnancy in a patient with a hypokinetic dilated cardiomyopathy. This case report emphasizes the fetal renal impact of prolonged intrauterine exposure to renin-angiotensin system (RAS) blockers, and highlights that this exposure can cause severe prenatal hypocalvaria. This delayed ossification can be reversible after birth, but the presence of anhydramnios indicates an early and irreversible block of RAS blockers in the fetus that is responsible for fetal kidney development abnormalities. This association carries a high risk of neonatal death. Prolonged exposure to ARA II or other RAS blockers remains prohibited throughout pregnancy.

Placental transfer and mammary excretion of a novel angiotensin receptor blocker fimasartan in rats

Background

Fimasartan (FMS) is a potent angiotensin receptor blocker for the treatment of mild to moderate hypertension. This study aimed to evaluate the transfer of FMS to fetus and breast milk in rats.

Methods

In order to study the transfer to the fetus and nursing pup, pregnant and nursing maternal rats were administered with FMS by a constant intravenous infusion to reach target plasma concentrations of 200 ng/mL and 100 ng/mL. The concentrations of FMS in plasma, placenta, amniotic fluid, fetus, and milk were determined by a validated LC-MS/MS assay.

Results

Upon constant intravenous infusion, the plasma FMS concentration reached the target steady state concentrations (C_ss = 200 ng/mL and 100 ng/mL) in 24 h. The tissue-to-plasma partition coefficients (K_p) for placenta, amniotic fluid, and milk were obtained based on the observed FMS concentrations in the tissues and C_ss. The K_p values for all tissues were not different between high (C_ss = 200 ng/mL) and low (C_ss = 100 ng/mL) dose groups. While the mean K_p of the placenta was 44.6–59.0 %, the mean K_p was 1.3–1.7 % for the amniotic fluid and 14.9–17.0 % for fetus. The mean K_p of milk was 10.4–15.2 %.

Conclusions

Placental transfer and milk excretion of FMS was relatively lower compared to other angiotensin receptor blockers.

Regulator of G protein signaling 5 is a determinant of gestational hypertension and preeclampsia

Preeclampsia is a systemic vascular disorder of pregnancy and is associated with increased sensitivity to angiotensin II (AngII) and hypertension. The cause of preeclampsia remains unknown. We identified the role of regulator of G protein (heterotrimeric guanine nucleotide–binding protein) signaling 5 (RGS5) in blood pressure regulation during pregnancy and preeclampsia. RGS5 expression in human myometrial vessels is markedly suppressed in gestational hypertension and/or preeclampsia. In pregnant RGS5-deficient mice, reduced vascular RGS5 expression causes gestational hypertension by enhancing vascular sensitivity to AngII. Further challenge by increasing AngII results in preeclampsia-like symptoms, namely, more severe hypertension, proteinuria, placental pathology, and reduced birth weight. In pregnant heterozygote null mice, treatment with peroxisome proliferator–activated receptor (PPAR) agonists normalizes vascular function and blood pressure through effects on RGS5. These findings highlight a key role of RGS5 at the interface between AngII and PPAR signaling. Because preeclampsia is refractory to current standard therapies, our study opens an unrecognized and urgently needed opportunity for treatment of gestational hypertension and preeclampsia.

Endothelium-dependent relaxation and angiotensin II sensitivity in experimental preeclampsia

Objective

We investigated endothelial dysfunction and the role of angiotensin (Ang)-II type I (AT1-R) and type II (AT2-R) receptor in the changes in the Ang-II sensitivity in experimental preeclampsia in the rat.

Methods

Aortic rings were isolated from low dose lipopolysaccharide (LPS) infused pregnant rats (experimental preeclampsia; n=9), saline-infused pregnant rats (n=8), and saline (n=8) and LPS (n=8) infused non-pregnant rats. Endothelium-dependent acetylcholine--mediated relaxation was studied in phenylephrine-preconstricted aortic rings in the presence of vehicle, N^G-nitro-L-arginine methyl ester and/or indomethacin. To evaluate the role for AT1-R and AT2-R in Ang-II sensitivity, full concentration response curves were obtained for Ang-II in the presence of losartan or PD123319. mRNA expression of the AT1-R and AT2-R, eNOS and iNOS, COX1 and COX2 in aorta were evaluated using real-time RT-PCR.

Results

The role of vasodilator prostaglandins in the aorta was increased and the role of endothelium-derived hyperpolarizing factor and response of the AT1-R and AT2-R to Ang-II was decreased in pregnant saline infused rats as compared with non-pregnant rats. These changes were not observed during preeclampsia.

Conclusion

Pregnancy induced adaptations in endothelial function, which were not observed in the rat model for preeclampsia. This role of lack of pregnancy induced endothelial adaptation in the pathophysiology of experimental preeclampsia needs further investigation.

Prognosis and outcome of pregnancies exposed to renin-angiotensin system blockers

OBJECTIVE

To study pregnancy outcomes and fetal renal prognosis markers in cases of exposure to renin-angiotensin system blockers.

METHODS

We conducted a retrospective study of a series of 21 patients exposed to blockers of the renin-angiotensin system during pregnancy. Two markers were prenatally studied, fetal serum β2-microglobulin and amniotic fluid volume. Poor renal prognosis evaluation was based on postnatal glomerular filtration rate or on the presence of renal histologic lesions.

RESULTS

Of the 21 fetuses, only one had a normal postnatal renal function at birth (oligohydramnios regression and normal β2-microglobulin). All fetuses with persistent oligohydramnios or β2-microglobulin ≥ 5 mg/L presented an adverse renal outcome.

CONCLUSION

Exposure to renin-angiotensin system blockers complicated by oligohydramnios is associated with a very poor outcome. We propose a prenatal management based on amniotic fluid volume monitoring and fetal serum β2-microglobulin. However, our preliminary results have to be confirmed by a larger study.

Is there an embryopathy associated with first-trimester exposure to angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists? A critical review of the evidence

Drugs that interfere with the renin-angiotensin system, such as angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), are widely used to manage hypertension and heart failure. Adequate functioning of the RAS is essential for normal fetal kidney development. The potential for ACEIs and ARBs to impair fetal and neonatal renal function if taken after the first trimester of pregnancy has been well documented. Although these drugs were not found to be teratogenic in animals, until recently little was known about the teratogenic effects of ACEIs and ARBs in humans when exposure was limited to the first trimester of pregnancy. New evidence from epidemiologic studies indicates that there may be an elevated teratogenic risk when these drugs are taken during the first trimester of pregnancy. However, this elevated risk does not appear to be specific to ACEIs and ARBs, but is instead related to maternal factors and diseases that typically coexist with hypertension in pregnancy, such as diabetes, advanced maternal age, and obesity. Women who become pregnant while being treated with an ACEI or ARB should be advised to avoid exposure to these drugs during the second and third trimesters of pregnancy by switching to a different class of antihypertensive drugs between weeks 8 and 10 after conception.

Angiotensin II type 2 receptor is critical for the development of human fetal pancreatic progenitor cells into islet-like cell clusters and their potential for transplantation

Local renin-angiotensin systems (RASs) regulate the differentiation of tissue progenitors. However, it is not known whether such systems can regulate the development of pancreatic progenitor cells (PPCs). To address this issue, we characterized the expression profile of major RAS components in human fetal PPC preparations and examined their effects on the differentiation of PPCs into functional islet-like cell clusters (ICCs). We found that expression of RAS components was highly regulated throughout PPC differentiation and that locally generated angiotensin II (Ang II) maintained PPC growth and differentiation via Ang II type 1 and type 2 (AT(1) and AT(2)) receptors. In addition, we observed colocalization of AT(2) receptors with critical β-cell phenotype markers in PPCs/ICCs, as well as AT(2) receptor upregulation during differentiation, suggesting that these receptors may regulate β-cell development. In fact, we found that AT(2) , but not AT(1) , receptor was a key mediator of Ang II-induced upregulation of transcription factors important in β-cell development. Furthermore, lentivirus-mediated knockdown of AT(2) receptor suppressed the expression of these transcription factors in ICCs. Transplantation of AT(2) receptor-depleted ICCs into immune-privileged diabetic mice failed to ameliorate hyperglycemia, implying that AT(2) receptors are indispensable during ICC maturation in vivo. These data strongly indicate that a local RAS is involved in governing the functional maturation of pancreatic progenitors toward the endocrine lineage.

[Pregnancy hypertension]

Hypertension occurs in 6-8% of pregnancies, preeclampsia in 2%, found to be "severe" in 0.6%. Preeclampsia remains a major cause of foetal, and even maternal, mortality. Two different aspects are described: "maternal" preeclampsia is related to pre-existent vascular lesions in the mother, "placental" preeclampsia is due to a primary defect in early placentation. The earliest disorder seems to be a "materno-foetal immune maladaptation", characterized by a defective cooperation between uterine NK cells and foetal HLA-C. Defective angiogenesis is also involved, which has been accounted for by an abnormal production of soluble receptors for angiogenic factors and TGF-beta. The resulting placental ischemia is responsible for an increased shedding of trophoblastic debris in the maternal circulation, an inflammatory syndrome, and finally generalized endothelial dysfunction, which is the clue to maternal symptoms. Clinical presentations range from benign isolated hypertension to life-threatening severe preeclampsia, which entails a major risk of maternal complications and foetal death. Antihypertensive treatment does not improve the foetal or maternal prognosis, in spite of blood pressure lowering. Very early preventive treatments have been developed, which seem largely more promising. Research is very active in this field. Finally, women who had preeclampsia are more prone to future hypertension, type 2 diabetes, or coronary disease.

Angiotensin II receptor antagonists against migraine in pregnancy: fatal outcome

A pregnant young woman with a severe migraine is prescribed candesartan, an angiotensin II type 1 receptor antagonist (AT II antagonists). This has a positive effect-except for severe maldevelopment of her fetus. There is an increase in the use of the fetotoxic drugs, AT II antagonists and angiotensin-converting enzyme inhibitors, as prophylactic treatment of migraines, in addition to their use as hypertensives.

[Drugs during preeclampsia. Fetal risks and pharmacology]

During pregnancy, the maternal, placental and fetal physiological characteristics constantly evolve and thereby constantly alter drug bioavailability in the mother and feto-placental unit. Gastric emptying time is increased and bowel movements are reduced. Distribution in the maternal body is mainly influenced by body mass variations, water content and fat stores. Metabolic capacity of the liver appears unchanged but renal clearance of drugs is gradually increased. The placental transfer of most drugs mainly consists of passive diffusion between the maternal and fetal circulations, along their respective concentration gradients. Only the free, unbound and non-ionized fraction of the drug readily crosses the membranes. Four anti-hypertensive drugs have been granted a license for the treatment of PE since the year 2000: these are Clonidine (Catapressan), Nicardipine (Loxen+), Labetalol (Trandate), Dihydralazine (Nepressol). Dihydralazine, Labetalol and Nicardipine are not contraindicated in the breast feeding mother. The administration of a long acting Benzodiazepine during pregnancy can lead to new born intoxication of variable severity and duration. These symptoms may precede a withdrawal syndrome (hyper-excitability, tremor, gastro-intestinal upset, such as diarrhea or vomiting). Breast feeding by mothers using benzodiazepines (Nitrazepam and Midazolam) is not recommended. In France, the use of low molecular weight heparins is not recommended during pregnancy whereas in the United States, they are recommended as a prophylactic measure. Their high molecular weight prevents their diffusion across the placental membrane and therefore prevents any fetal or neonatal risk. Bromocriptine is used as an inhibitor of lactation. During the post-partum period, serious accidents have been described: these consist of systemic hypertension, fits, infarcts (cardiac and neurological). It is contraindicated in case of systemic hypertension.

Medications during pregnancy: antihypertensives and immunosuppressives

Use of prescription and nonprescription medications is common during pregnancy and is required in many women with underlying kidney disease or hypertension and in all with solid-organ allografts. Systematic assessment of drug safety during pregnancy is lacking, as are rigorous and comprehensive studies of pharmacokinetics and pharmacodynamics to guide drug selection and dosing across pregnancy. Renal and hepatic clearances of many drugs change markedly during pregnancy and pitfalls may complicate routine therapeutic monitoring of some drugs during pregnancy. However, available data and clinical experience allow reasonable strategies for selection and dosing of immunosuppressive agents in pregnant transplant recipients and of antihypertensive agents in women with mild or more severe hypertension complicating their pregnancies.

Drugs and the fetus

PURPOSE OF REVIEW

Few drugs are licensed in pregnancy, and data on drug use in pregnancy are mainly retrospective and uncontrolled. Pregnancy exposure has increased recently to new classes of drugs, as they have been shown to be effective and well tolerated outside of pregnancy.

RECENT FINDINGS

Anti-nausea therapies, H2-receptor and proton pump inhibitors appear to be safe. Metformin is being trialed for treatment in gestational diabetes and initial reports appear encouraging. Concern has been raised about statins in early pregnancy and should be avoided. New antiepileptic medication appears effective with low risk of abnormality. However, when combined with valproate, risks are still high. Selective serotonin reuptake inhibitors for depression appear to be effective, with likely low risk for teratogenesis, although neonatal behavioural syndrome following their use in the third trimester is a concern. Angiotensin II inhibitors should be avoided in the second and third trimesters of pregnancy. Smoking cessation programmes need to be reevaluated.

SUMMARY

Information about safety of drugs and caution about prescribing in pregnancy should continue. Until large clinical trials are performed, the risk/benefit ratio of drugs during pregnancy will remain uncertain.