Pharmacogenetics in the treatment of pre-eclampsia: current findings, challenges and perspectives

Pharmacogenomics of Preeclampsia therapies: Current evidence and future challenges for clinical implementation

Preeclampsia is a pregnancy-specific disorder, and it is a leading cause of maternal and perinatal morbidity and mortality. The application of pharmacogenetics to antihypertensive agents and dose selection in women with preeclampsia is still in its infancy. No current prescribing guidelines from the clinical pharmacogenetics implementation consortium (CPIC) exist for preeclampsia. Although more studies on pharmacogenomics are underway, there is some evidence for the pharmacogenomics of preeclampsia therapies, considering both the pharmacokinetic (PK) and pharmacodynamic (PD) properties of drugs used in preeclampsia. It has been revealed that the CYP2D6*10 variant is significantly higher in women with preeclampsia who are non-responsive to labetalol compared to those who are in the responsive group. Various genetic variants of PD targets, i.e., NOS3, MMP9, MMP2, TIMP1, TIMP3, VEGF, and NAMPT, have been investigated to assess the responsiveness of antihypertensive therapies in preeclampsia management, and they indicated that certain genetic variants of MMP9, TIMP1, and NAMPT are more frequently observed in those who are non-responsive to anti-hypertensive therapies compared to those who are responsive. Further, gene-gene interactions have revealed that NAMPT, TIMP1, and MMP2 genotypes are associated with an increased risk of preeclampsia, and they are more frequently observed in the non-responsive subgroup of women with preeclampsia. The current evidence is not rigorous enough for clinical implementation; however, an institutional or regional-based retrospective analysis of audited data may help close the knowledge gap during the transitional period from a traditional approach (a "one-size-fits-all" strategy) to the pharmacogenomics of preeclampsia therapies.

ARG2 single-nucleotide polymorphism rs3742879 affects plasma arginase 2 levels, nitric oxide formation and antihypertensive therapy response in preeclampsia

Aim: This work examined whether ARG1 (rs2781659, rs2781667, rs2246012 and rs17599586) and ARG2 (rs3742879 and rs10483801) single-nucleotide polymorphisms (SNPs) are associated with antihypertensive therapy responsiveness in preeclampsia (PE) and their effects on arginase isoforms and nitrite concentrations in responsive and nonresponsive patients. Methods: SNP genotypes were determined by TaqMan assays. Plasma arginase levels were measured by ELISA and nitrite concentrations were measured using an ozone-based chemiluminescence assay. Results: The G allele for ARG2 rs3742879 (A>G) was less frequent in nonresponsive compared with responsive patients (15.5% vs 24.7%) and the G carriers of the nonresponsive subgroup had lower arginase 2 (9.2 ± 7.5 ng/ml vs 19.1 ± 17.3 ng/ml) and higher nitrite concentrations (110.2 ± 52.8 nM vs 78.5 ± 37.9 nM) than carriers of the AA genotype (all p < 0.05). Conclusion: ARG2 SNP rs3742879 is associated with diminished arginase 2 levels and increased nitric oxide formation in nonresponsive PE patients.

LncRNA small nucleolar RNA host gene 5 inhibits trophoblast autophagy in preeclampsia by targeting microRNA-31-5p and promoting the transcription of secreted protein acidic and rich in cysteine

Preeclampsia (PE) is a pregnancy-related complication. Dysregulation of long non-coding RNAs (lncRNAs) contributes to the pathogenesis of PE. The current study sought to investigate the effect of lncRNA small nucleolar RNA host gene 5 (SNHG5) on trophoblast autophagy in PE. A PE mouse model was established, followed by detection of parameters such as blood pressure, proteinuria, triglycerides, total cholesterol, low-density lipoprotein, and high-density lipoprotein, observation of alterations of mouse placenta and kidney, and detection of B-cell chronic lymphocytic leukemia/lymphoma-2, Bcl-2-associated X protein, and SNHG5 expression patterns. The expressions of LC3, Beclin-1, and p62 in the placenta of PE mice were detected. Moreover, the SNHG5 expression was downregulated in the established HTR-8/SVneo trophoblast model, followed by evaluation of cell proliferation, apoptosis, and autophagy. After combination treatment with 3-MA (an autophagy inhibitor) and si-SNHG5, the behaviors of HTR-8/SVneo cells were observed. The binding relations between SNHG5 and miR-31-5p, and miR-31-5p and SPARC were verified. The expressions of miR-31-5p and SPARC in the placenta of mice and trophoblasts were determined. Our results demonstrated a poor expression of lncRNA SNHG5 in PE mice. SNHG5 overexpression reduced the PE phenotype and tissue damage in mice. SNHG5 silencing reduced the proliferation, migration, and invasion of trophoblasts, but elevated apoptosis and autophagy. SNHG5 sponged miR-31-5p to promote SPARC transcription. Additionally, miR-31-5p knockdown or 3-MA treatment reverted the stimulative effect of SNHG5 silencing on trophoblast autophagy. Collectively, our study demonstrated that lncRNA SNHG5 alleviated the PE phenotype and inhibited trophoblast autophagy by sponging miR-31-5p and promoting SPARC transcription.

Preeclampsia and Gestational Hypertension: Biochemical and Antioxidant Features in Vitro Might Help Understand Different Outcomes

OBJECTIVE

 Gestational hypertension (GH) is characterized by increased blood pressure after the 20^th gestational week; the presence of proteinuria and/or signs of end-organ damage indicate preeclampsia (PE). Heme oxygenase-1 (HO-1) is an antioxidant enzyme with an important role in maintaining endothelial function, and induction of HO-1 by certain molecules shows potential in attenuating the condition's effects over endothelial tissue. HO-1 production can also be stimulated by potassium iodide (KI). Therefore, we evaluated the effects of KI over HO-1 expression in human umbilical vein endothelial cells (HUVECs) incubated with plasma from women diagnosed with GH or PE.

METHODS

 Human umbilical vein endothelial cells were incubated with a pool of plasma of healthy pregnant women (n = 12), pregnant women diagnosed with GH (n = 10) or preeclamptic women (n = 11) with or without the addition of KI for 24 hours to evaluate its effect on this enzyme expression. Analysis of variance was performed followed by Dunnet's test for multiple comparisons between groups only or between groups with addition of KI (p ≤ 0.05).

RESULTS

 KI solution (1,000 µM) reduced HO-1 in the gestational hypertension group (p = 0.0018) and cytotoxicity in the preeclamptic group (p = 0.0143); treatment with KI reduced plasma cytotoxicity but did not affect the preeclamptic group's HO-1 expression.

CONCLUSION

 Our findings suggest that KI alleviates oxidative stress leading to decreased HO-1 expression; plasma from preeclamptic women did not induce the enzyme's expression in HUVECs, and we hypothesize that this is possibly due to inhibitory post-transcriptional mechanisms in response to overexpression of this enzyme during early pregnancy.

Placental Ischemia Says "NO" to Proper NOS-Mediated Control of Vascular Tone and Blood Pressure in Preeclampsia

In this review, we first provide a brief overview of the nitric oxide synthase (NOS) isoforms and biochemistry. This is followed by describing what is known about NOS-mediated blood pressure control during normal pregnancy. Circulating nitric oxide (NO) bioavailability has been assessed by measuring its metabolites, nitrite (NO₂) and/or nitrate (NO₃), and shown to rise throughout normal pregnancy in humans and rats and decline postpartum. In contrast, placental malperfusion/ischemia leads to systemic reductions in NO bioavailability leading to maternal endothelial and vascular dysfunction with subsequent development of hypertension in PE. We end this article by describing emergent risk factors for placental malperfusion and ischemic disease and discussing strategies to target the NOS system therapeutically to increase NO bioavailability in preeclamptic patients. Throughout this discussion, we highlight the critical importance that experimental animal studies have played in our current understanding of NOS biology in normal pregnancy and their use in finding novel ways to preserve this signaling pathway to prevent the development, treat symptoms, or reduce the severity of PE.

Therapeutic Drug Monitoring in Pregnant Patients

During pregnancy, there are several physiological changes during each trimester that can affect the absorption, distribution, metabolism, and elimination of drugs. Although there is a potential need to understand the pharmacokinetics and pharmacodynamics of drugs in pregnant patients, therapeutic drug monitoring is not well established for various drug classes due to ethical and safety concerns regarding the neonate. Potential risks from in utero drug exposure to the fetus may impact growth and development and may cause malformations or teratogenesis. The clinician must consider the benefits of drug treatment for the pregnant mother versus the risk to the fetus, before prescribing medications during pregnancy. The objective of this review is to aid clinicians, pharmacists, and laboratorians in understanding the pharmacokinetic and pharmacodynamic changes during pregnancy, to provide drug class recommendations for monitoring therapy throughout pregnancy via therapeutic drug monitoring, and to highlight the recent directives of governing agencies on maternal and fetal health.

NAMPT single-nucleotide polymorphism rs1319501 and visfatin/NAMPT affect nitric oxide formation, sFlt-1 and antihypertensive therapy response in preeclampsia

Aim: We examined the relationships between visfatin/NAMPT and nitrite concentrations (a marker of nitric oxide [NO] formation) or sFlt-1 levels in 205 patients with preeclampsia (PE) responsive or nonresponsive to antihypertensive therapy, and whether NAMPT SNPs rs1319501 and rs3801266 affect nitrite concentrations in PE and 206 healthy pregnant women. Patients & methods: Circulating visfatin/NAMPT and sFlt-1 levels were measured by ELISA, and nitrite concentrations by using an ozone-based chemiluminescence assay. Results: In nonresponsive PE patients, visfatin/NAMPT levels were inversely related to nitrite concentrations and positively related to sFlt-1 levels. NAMPT SNP rs1319501 affected nitrite concentrations in nonresponsive PE patients and was tightly linked with NAMPT functional SNPs in Europeans. Conclusion: NAMPT SNP rs1319501 and visfatin/NAMPT affect NO formation, sFlt-1 levels and antihypertensive therapy response in PE.

Global DNA methylation in placental tissues from pregnant with preeclampsia: A systematic review and pathway analysis

Pre-eclampsia (PE) is the major cause of fetal and maternal mortality and can be classified according to gestational age of onset into early-onset (EOPE, <34 weeks of gestation) and late- (LOPE, ≥34 weeks of gestation). DNA methylation (DNAm) may help to understand the abnormal placentation in PE. Therefore, we performed a systematic review to assess the role of global DNAm on pathophysiology of PE, focused on fetal and maternal tissues of placenta from pregnant with PE, including EOPE and LOPE. We searched the databases EMBASE, Medline/PubMed, Cochrane Central Register of Controlled Trials, Scopus, Lilacs, Scielo and Google Scholar, and followed the MOOSE guidelines. Moreover, we performed pathway analysis with the overlapping genes from the included studies. Twelve out of 24 included studies in the qualitative analysis considered the classification into EOPE and LOPE. We did not found heterogeneity in the criteria used for diagnosis of PE, and a few studies evaluated whether confounding factors would influence placental DNAm. Fourteen out of 24 included studies showed hypomethylation in placental tissue from pregnant with PE compared to controls. The differences in DNAm are specific to genes or differentially methylated regions, and more evident in EOPE and preterm PE compared to controls, rather than LOPE and term PE. The overlapping genes from included studies revealed pathways relevant to pathophysiology of PE. Our findings highlighted the heterogeneous results of the included studies, mainly focused on North America and China. Replication studies in different populations should use the same placental tissues, techniques to assess DNAm and pipelines for bioinformatic analysis.

Pharmacogenetic Implications of eNOS Polymorphisms (Glu298Asp, T786C, 4b/4a) in Cardiovascular Drug Therapy

Endothelial nitric oxide synthase (NOS3 or eNOS) is the enzyme responsible for the highest production of nitric oxide, with the greatest impact on the cardiovascular system, encoded by the eNOS gene, which presents various polymorphisms. ENOS gene polymorphisms play an important role in the response to drugs affecting nitric oxide (NO) signaling. This review discusses the pharmacogenetic impact of eNOS polymorphisms on the response to drugs affecting NO activity: angiotensin converting enzyme inhibitors, angiotensin II receptor antagonists, calcium blockers, beta-blockers, diuretics, phosphodiesterase inhibitors, and statins. The identification of biomarkers that accurately predict particular phenotypes is a challenge that needs additional large studies, in different populations. Efforts should be oriented towards a more accurate evaluation of the effects of eNOS genetic variants on biochemical parameters reflecting eNOS gene expression and enzymatic activity, in different diseases, as well as following drug treatment. This approach will allow for a better understanding of the role of eNOS genetic variants in cardiovascular disease progression and for cardiovascular drug therapy optimization.

Pharmacogenetic relevance of endothelial nitric oxide synthase polymorphisms and gene interactions

Endothelial nitric oxide synthase (NOS3) is a key enzyme responsible for nitric oxide (NO) generation in the vascular endothelium. Endothelial dysfunction is characterized by reduced NO production, and is a hallmark of cardiovascular diseases. Drugs with cardiovascular action may activate NOS3 and result in NO release and vasodilation. Moreover, genetic variations affect NOS3 expression and activity, and may partially explain the variability in the responses to cardiovascular drugs. We reviewed NO signaling and genetic effects on NO formation, and the effects of NOS3 polymorphisms, haplotypes and gene-gene interactions within NO signaling pathways on the responses to cardiovascular drugs. We discuss the role of rare NOS3 variants and further gene-gene interactions analysis for the development of novel therapies for cardiovascular diseases.

Pharmacogenomics of Hypertension and Preeclampsia: Focus on Gene-Gene Interactions

Hypertension is a leading cause of cardiovascular mortality, but only about half of patients on antihypertensive therapy achieve blood pressure control. Preeclampsia is defined as pregnancy-induced hypertension and proteinuria, and is associated with increased maternal and perinatal mortality and morbidity. Similarly, a large number of patients with preeclampsia are non-responsive to antihypertensive therapy. Pharmacogenomics may help to guide the personalized treatment for non-responsive hypertensive patients. There is evidence for the association of genetic variants with variable response to the most commonly used antihypertensive drugs. However, further replication is needed to confirm these associations in different populations. The failure to replicate findings from single-locus association studies has prompted the search for novel statistical methods for data analysis, which are required to detect the complex effects from multiple genes to drug response phenotypes. Notably, gene–gene interaction analyses have been applied to pharmacogenetic studies, including antihypertensive drug response. In this perspective article, we present advances of considering the interactions among genetic polymorphisms of different candidate genes within pathways relevant to antihypertensive drug response, and we highlight recent findings related to gene–gene interactions on pharmacogenetics of hypertension and preeclampsia. Finally, we discuss the future directions that are needed to unravel additional genes and variants involved in the responsiveness to antihypertensive drugs.