- Open Access
Apolipoprotein A1 mimetic peptide ATI-5261 reverses arterial stiffness at late pregnancy and early postpartum in a COMT−/− mouse model of preeclampsia
Clinical Hypertensionvolume 24, Article number: 11 (2018)
Preeclampsia (PE) is a serious maternal complication during pregnancy. Associated arterial stiffness in PE patients leads to increased risks of cardiovascular diseases later in life. Cholesterol efflux capacity, especially ATP binding cassette transporter A1 (ABCA1) dependent capacity, has been proposed to be a likely mediator of arterial stiffness. In the present study, we aimed to evaluate the effect of an apolipoprotein A1 mimetic peptide ATI-5261 on arterial stiffness in a mouse model of PE.
Pregnant COMT−/− mice were randomized to receive vehicle or ATI-5261 (30 mg/kg per day) via subcutaneous injection from gestational days (GD) 10.5 to GD 18.5 or to 10 days postpartum. Pregnant C57BL/6 J mice received vehicle during paralleled periods were served as normal controls.
COMT−/− mice displayed maternal hypertension and proteinuria during pregnancy. Carotid–femoral pulse wave velocity (PWV) was increased at GD 18.5 and 10 days postpartum. ATI-5261 treatment in COMT−/− mice significantly reduced PWV and partially normalized impaired ex vivo vascular function at late pregnancy and early postpartum. ATI-5261 treatment also increased serum ABCA1 concentrations and cholesterol efflux capacity, as well as ABCA1 expressions in the placenta. Pup weights, crown to rump lengths and abdominal circumferences were reduced in COMT−/− mice. Treatment with ATI-5261 did not alter these fetal measurements but significantly reduced placental weights and increased fetal to placental ratios in COMT−/− mice.
ATI-5261 reversed arterial stiffness at late pregnancy and early postpartum in a COMT−/− mouse model of PE and may be a potential therapy for arterial stiffness associated with PE.
Preeclampsia (PE), defined as the development of maternal hypertension with proteinuria after 20 weeks of pregnancy, is one of leading causes of maternal and perinatal mortality and morbidity [1, 2]. Women with PE are at increased risks of cardiovascular diseases later in life, which may be associated with persisting endothelial, cardiovascular, and metabolic dysfunction, as well as increased arterial stiffness following preeclamptic pregnancies [3,4,5].
Arterial stiffness, as a consequence of normal aging, endothelial dysfunction, vascular smooth muscle cell hyperplasia and inflammation, has been demonstrated to be a predictor for increased risk for cardiovascular diseases, including stroke, coronary artery disease and heart failure, independent from blood pressure [6,7,8]. Previous studies suggest that cholesterol efflux affects several factors that are mechanistic in arterial stiffness, such as endothelial function and inflammation [9, 10]. Therefore, cholesterol efflux has been proposed to be a likely mediator of arterial stiffness supported by increasing evidence . The initial and rate-limiting step of cholesterol efflux is the transport of cellular free cholesterol to high-density lipoprotein (HDL) by cholesterol transporters, of which the best characterized are the ATP binding cassette transporter (ABC) A1, ABCG1 and scavenger receptor BI (SR-BI) . As the major cell-surface transporter, ABCA1 appears to be the main contributor to arterial stiffness changes in terms of structural and cellular function. For example, ABCA1-dependent cholesterol efflux capacity is inversely associated with pulse wave velocity (PWV) in healthy subjects . ABCA1 facilitates the release of prostaglandins in endothelial cells, resulting in anti-stiffening effects through vasodilation . In addition, the role of ABCA1 in modulating the inflammatory response has been highlighted from animal models and humans .
Apolipoprotein (Apo) A1 is the major component of HDL protein that facilitates cholesterol efflux from peripheral cells through ABCA1. ATI-5261 is a 26-amino acid Apo A1 mimetic peptide designed from c-terminus of Apo E. It has been demonstrated that ATI-5261 mimics the activity of native Apo A1 and promotes cellular cholesterol efflux via the ABCA1 in vitro [16,17,18]. Providing the observations that decreased ABCA1-mediated cholesterol efflux capacity, as well as decreased placental expressions and serum levels of ABCA1 in PE patients [19,20,21,22,23], we hypothesized that ATI-5261 treatment could reverse the impaired ABCA1-dependent cholesterol efflux associated with PE and reduce arterial stiffness in this condition. Therefore, we investigated the effect of ATI-5261 treatment on arterial stiffness in a mouse model of PE.
ATI-5261 was synthesized (Biosynthesis Inc.) from all L-amino acids (EVRSKLEEWFAAFREFAEEFLARLKS) and capped with N-terminal acetyl and C-terminal amide groups. The lyophilized peptide (∼95% of purity) was dissolved in 10 mM phosphate buffer saline (150 mM NaCl; pH 7.4), filter sterilized (0.2 μm), and stored at 4 °C until use .
This study was performed in accordance to the Guide for the Care and Use of Laboratory Animals published by the US NIH. All protocols were approved by the Animal Ethics Committee of Wenzhou Medical University (WZU38479–567). Female homozygous catechol-O-methyl transferase knockout (COMT−/−; Cyagen Biosciences Inc.) mice and C57BL/6 J mice (Jackson laboratories) aged 8 to 12 weeks were housed under standard conditions and maintained at 22 °C with a 12-h light/dark cycle and with ad-libitum access to food and water. Special care was taken during experimental procedures to minimize stress and discomfort to the animals. Females were mated nightly with males of a corresponding genotype and the day a vaginal plug detected was denoted as gestational day (GD) 0.5. Maternal body weight was monitored daily. Arterial blood pressure was measured in conscious mice, using the tail-cuff method before mating, at GD 10.5 and GD 18.5, and at 10 days postpartum. Mice were habituated to the restraining system for 4 consecutive days before the first measurement. ATI-5261 or vehicle was administrated via subcutaneous injection in the skinfold at the nape of neck using tuberculin syringes daily. Mice were treated with ATI-5261 at a dose of 30 mg/kg per day as one study suggests that treatment with this dose significantly reduced atherosclerosis and increased reverse cholesterol transport in Apo E−/− mice . Pregnant COMT−/− mice (n = 8 per group) were randomized into 4 groups: Group A and B: mice were treated with ATI-5261 or vehicle from GD 10.5 to GD 18.5; Group C and D: mice were treated with ATI-5261 or vehicle from GD 10.5 to 10 days postpartum. Pregnant C57BL/6 J mice (n = 8 per group) also received vehicle treatment from GD 10.5 to GD 18.5 or to 10 days postpartum and were served as normal controls (designed as Group E and F). Urine samples from all groups were collected using a clear plastic wrap at GD 18.5 as previously described . All mice were anaesthetized by inhalation of 5% sevoflurane and then euthanized by cervical dislocation. Mice in Group A, B and E were killed at GD 18.5 and pups and placentas dissected out. Litter sizes, pup weights and placenta weights were recorded. Fetal crown-to rump lengths and abdominal circumferences were measured. Embryonic death was determined by the presence of fetal resorption. The embryo resorption rate was calculated as the number of reabsorbed embryos/total number of embryos. Mice in Group C, D and F were culled at 10 days postpartum. Blood samples from all groups were taken by cardiac puncture and maternal livers were collected following euthanasia. Urine, serum and tissue specimens were stored at − 80 °C for further analysis.
Pulse wave velocity assessment
Carotid–femoral pulse wave velocity (PWV) was determined noninvasively using applanation tonometry as described previously . In brief, sevoflurane anaesthesia (8% and 5% in oxygen for induction and maintenance, respectively, 1.5 L/min) was used to immobilize the animals during tonometry measurements. Two pulse tonometers (SPT-301, Millar Instruments) were applanated on the skin of the right carotid and femoral arteries using a micromanipulator. The distances between the sternal notch and both measurement sites (carotid and femoral artery) were measured using a sliding caliper. Carotid–femoral transit time was determined using the time difference between the foot of carotid and femoral artery pulses. Carotid–femoral PWV was then calculated as the external carotid–femoral distance divided by transit time. PWV values of pregnant mice were recorded at GD 18.5 and 10 days postpartum.
The thoracic arteries were dissected from C57BL/6 J and COMT−/− mice at GD 18.5 and 10 days postpartum following euthanasia. Aortic ring segments 3–4 mm in length were prepared and wire myography was performed using an isometric wire myograph system (610 M wire myography; Danish Myo Techniques) as described previously . Ex vivo vascular function was investigated by determining vasoconstrictor responses to phenylephrine (PE), endothelium-dependent relaxation, following PE pre-constriction, in response to methacholine (Mch), and endothelium-independent relaxation to the nitric oxide (NO) donor sodium nitroprusside (SNP). Finally, high potassium solution (KPSS mmol/L; 12.45 NaCl, 25 NaHCO3, 120 KCl, 2.4 MgSO4, 1.6 CaCl2, 1.18 KH2PO4, 5 glucose, 0.034 EDTA; pH 7.4) was added and the constriction allowed to plateau. Data were continuously collected and the vessel active wall tension (ΔT in mN/mm) was transformed to active effective pressure [ΔT/(diameter/2000)] denoted by kPa.
Urine and blood analysis
The concentrations of urine albumin (Abcam, UK) and creatinine (CrystalChem, US), as well as serum ABCA1 and ABCG1 (LifeSpan Biosciences, US) were measured by mouse-specific enzyme-linked immunosorbent assays (ELISAs) as per the manufacturers’ instructions.
Cholesterol efflux capacity assay
Apo B-depleted serum was prepared by addition of PEG 6000 using the method previously described . Cholesterol efflux capacity assays were performed using mouse cAMP-treated J774 macrophages and several cellular models: Chinese hamster ovary (CHO)-K1, CHO-ABCG1, and CHO-ABCA1 as previously described [29, 30]. [3H]-cholesterol-labelled cells were incubated 4 h at 37 °C in the presence of 40-fold diluted serum samples. ABCG1-dependent efflux was calculated as the difference between efflux to CHO-ABCG1 and CHO-K1 cells. The ABCA1-dependent efflux was calculated as the difference between efflux to activated CHO-ABCA1 induced by tetracycline (1 μg/mL) and nonactivated cells. Fractional cholesterol efflux was calculated as the amount of the label recovered in the medium divided by the total label in each well. All efflux experiments were performed in triplicate for each sample.
Whole-cell lysates were made from homogenized harvested maternal liver and placenta samples with radio-immunoprecipitation assay buffer (Abcam, UK) containing a protease inhibitor cocktail (Roche, UK). Protein concentrations were determined through a Direct Detect Spectrometer (Merck, Darmstadt, Germany). Western blot analysis was carried out under reducing conditions using specific antibodies (Novus Biologicals, US) to detect the expressions of ABCA1 (NB400–105), ABCG1 (NB400–132), SR-BI (NB400–104) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH; NB100–56875). Immune complexes were visualized using horseradish peroxidase-conjugated secondary antibody with enhanced chemiluminescence on a BioRad Chemidoc MP system.
All normally distributed data are expressed as means ± SEM and were compared using Student’s t test or one-way ANOVA with post-hoc analysis (Tukey’s procedure). Analysis was conducted using IBM SPSS Statistics 22. A p-value of < 0.05 was accepted as statistically significant.
Maternal blood pressure and proteinuria
Maternal blood pressure values are shown in Table 1 and Fig. 1a. Compared with nonpregnant state, systolic blood pressure in vehicle treated COMT−/− mice was significantly increased at GD 18.5 and the increased blood pressure returned to nonpregnant levels at 10 days after delivery; systolic blood pressure in vehicle treated C57BL/6 J mice was significantly decreased at GD 18.5; systolic blood pressure in ATI-5261 treated COMT−/− mice was unaltered during pregnancy. There were no significant differences in systolic blood pressure between nonpregnant COMT−/− mice and nonpregnant C57BL/6 J mice. Systolic blood pressure was significantly increased in vehicle treated or ATI-5261 treated COMT−/− mice compared with C57BL/6 J mice at GD 10.5. This increase was also observed at GD 18.5.
Proteinuria was assessed by calculating the albumin/creatinine ratio at GD 18.5. The ratio was significantly increased in vehicle treated or ATI-5261 treated COMT−/− mice compared with vehicle treated C57BL/6 J mice (Fig. 1b). Treatment with ATI-5261 had no effects on proteinuria.
Pulse wave velocity and arterial stiffness
Arterial stiffness was assessed by carotid–femoral PWV. Carotid–femoral PWV was significantly higher at GD 18.5 and 10 days postpartum in vehicle treated COMT−/− mice compared with C57BL/6 J mice (Table 1; Fig. 1c). ATI-5261 treatment significantly reduced carotid–femoral PWV in COMT−/− mice at GD 18.5 and 10 days postpartum (Table 1; Fig. 1c).
Ex vivo vascular function
Aortic arteries from COMT−/− mice exhibited increased constriction in response to PE as well as reduced relaxation in response to MCh, compared with arteries from C57BL/6 J mice (Fig. 2). After treatment with ATI-5261, artery constriction to PE in COMT−/− mice at doses of 3 × 10− 7 M, 10− 6 M and 3 × 10− 6 M was normalized to that in C57BL/6 J mice at GD 18.5 (Fig. 2a). Similarly, ATI-5261 treatment normalized artery constriction in COMT−/− mice at doses of 3 × 10− 7 M and 10− 6 M at 10 days postpartum (Fig. 2b). In terms of the endothelium-dependent relaxation response to MCh, ATI-5261 treatment normalized artery relaxation in COMT−/− mice at doses of 10− 7 M and 3 × 10− 7 M at GD 18.5 and at doses of 3 × 10− 8 M, 10− 7 M and 3 × 10− 7 M at 10 days postpartum, respectively (Fig. 2c and d). There were no differences in relaxation in response to SNP between groups at either GD 18.5 or 10 days postpartum (data not shown).
Fetal and placental measurements
Fetal and placental measurements are detailed in Table 2. Pup weights, crown to rump lengths and abdominal circumferences were decreased in vehicle treated COMT−/− mice compared with C57BL/6 J mice. Treatment with ATI-5261 did not alter these fetal measurements in COMT−/− mice. Placental weights were increased and fetal to placental ratios were decreased in vehicle treated COMT−/− mice compared with C57BL/6 J mice. ATI-5261 treatment significantly reduced placental weights and increased fetal to placental ratios in COMT−/− mice. There were no gross abnormalities after treatments with ATI-5261 in COMT−/− mice.
Serum ABCA1 and ABCG1
There were no significant differences in serum ABCA1 and ABCG1 concentrations at GD 18.5 between vehicle treated COMT−/− mice and C57BL/6 J mice (Fig. 3a and b). However, serum ABCA1 and ABCG1 concentrations were significantly decreased in vehicle treated COMT−/− mice at 10 days postpartum compared with C57BL/6 J mice (Fig. 3a and b). ATI-5261 treatment significantly increased serum ABCA1 in COMT−/− mice at GD 18.5 and 10 days postpartum (Fig. 3a) but had no effects on serum ABCG1 concentrations (Fig. 3b).
Cholesterol efflux capacity
Total cholesterol efflux capacity and ABCA1-dependent efflux were significantly increased in ATI-5261 treated COMT−/− mice at GD 18.5 compared to vehicle treated COMT−/− mice (Fig. 3c). The increases of total cholesterol efflux capacity and ABCA1-dependent efflux in ATI-5261 treated COMT−/− mice were also observed at 10 days postpartum (Fig. 3d). Interestingly, ABCA1-dependent efflux was decreased in vehicle treated COMT−/− mice at 10 days postpartum, compared to C57BL/6 J mice (Fig. 3d). ATI-5261 treatment normalized ABCA1-dependent efflux at 10 days postpartum (Fig. 3d). ABCG1-dependent efflux was not affected by mice genotypes or treatments (Fig. 3c and d).
Cholesterol acceptor/receptor expressions
Western blotting revealed that hepatic protein expressions of ABCA1, ABCG1 and SR-BI were decreased in COMT−/− mice at GD 18.5, compared to C57BL/6 J mice (Fig. 4a). Decreased hepatic ABCA1 expression was also observed at 10 days postpartum (Fig. 4b). At GD 18.5, placental protein expressions of ABCA1 and ABCG1 was reduced in COMT−/− mice, compared to C57BL/6 J mice (Fig. 4c and d). ATI-5261 treatment significantly increased hepatic expression of ABCA1 and ABCG1 in COMT−/− mice at 10 days postpartum and increased placental expression of ABCA1 but not ABCG1 at GD 18.5 (Fig. 4).
In the present study, we firstly demonstrated that treatments with ATI-5261 reduced arterial stiffness at late pregnancy and early postpartum in the COMT−/− mouse model of PE. ATI-5261 therapy was associated with increased serum ABCA1 concentration and cholesterol efflux capacity, as well as increased ABCA1 expression in the placenta and the liver.
The etiology of PE is currently unclear but there is a consensus that the placenta plays a key role in the pathogenesis of PE. It is believed that PE develops as consequences of impaired trophoblast invasion and inadequate remodelling of the uterine spiral arteries. Subsequent oxidative stress and inflammation in the placenta alters expressions of pro-inflammatory, anti-angiogenic and angiogenic factors, contributing to endothelial cell dysfunction and an inflammatory response . The vascular dysfunction in PE patients also presents as increased arterial stiffness during pregnancy and postpartum, which is associated with inflammation in this condition . However, various circulating factors that disturb the balance between vasodilatory and vasoconstrictor mechanisms are involved in the maternal vascular dysfunction of PE .
In the present study, we observed that systolic blood pressure was significantly decreased in C57BL/6 J mice at GD 18.5, compared with nonpregnant state. This phenomenon has also been demonstrated in previous studies [34,35,36]. However, the decline of maternal blood pressure was absent during COMT−/− mice pregnancy. It has been postulated that altered maternal blood pressure control during pregnancy may contribute to the development of PE , supporting the use of pregnant COMT−/− mice as an animal model of PE. Kanasaki et al. firstly demonstrated that pregnant COMT−/− mice displayed a PE-like phenotype resulting from an absence of 2-methoxyoestradiol (2-ME) . Following studies consistently observed maternal hypertension and increased proteinuria at late gestation, aberrant umbilical blood flow and vascular response, as wells as compromised fetal growth [39, 40]. Consistent results, particularly increased PWV and impaired vascular response, were also observed in our study. Interestingly, increased blood pressure at GD 18.5 returned to prepregnant level at 10 days after delivery. However, increased PWV persisted at 10 days postpartum. These observations suggest that persistent increased arterial stiffness may be associated with the deficiency in COMT in this mouse model of PE. 2-ME is generated by COMT in the placenta and elevated during normal human pregnancy [41, 42]. 2-ME counters angiogenesis and restores hypoxia-induced disruption by inhibiting hypoxia-inducible factor-1a [43, 44]. Emerging evidence suggests that 2-ME plays a role in cardiovascular function. It is reported that 2-ME attenuates hypertension and vascular remodelling , reduces atherosclerotic lesion formation  and inhibits neointima formation and smooth muscle cell growth [47, 48]. Moreover, 2-ME induces vasodilation by stimulating NO release in vascular endothelial cells , and regulates vascular tone and blood flow by inducing the synthesis of vasodilatory substances, such as NO and prostacyclin . In addition, pharmacological inhibition of COMT produces arterial hypertension and endothelial dysfunction in pregnant rats which may be attributed to reduced NO bioavailability. These factors may all contribute to the increased arterial stiffness and impaired vascular function observed in the present study.
The anti-inflammatory properties of HDL and Apo A1 are well established in previous studies [51, 52]. Apo A1 mimetic peptides display anti-inflammatory and antioxidant properties and function in part by promoting cholesterol efflux and reverse cholesterol transport via ABCA1 [53, 54]. Inflammation and oxidative stress are key potential mechanisms that could induce changes in the stiffness of arteries [55, 56]. Therefore, anti-inflammatory interventions are suggested to be able to improve arterial stiffness as a potential therapy, while beneficial effects have been shown in several studies [57,58,59]. In the present study, ATI-5261 treatment increased serum ABCA1 concentrations and ABCA1-dependent cholesterol efflux, accompanied by reduced arterial stiffness in COMT−/− mice. ABCA1 is well known for its role in regulating cholesterol transport to either cell surface-bound or internalized apolipoproteins and HDL formation . Through this process ABCA1 reduces the amount of free cholesterol present in the plasma membrane and decreases membrane lipid raft content, which dampens inflammatory signalling by reducing Toll-like receptors in lipid rafts [61, 62]. The interaction of Apo A1 and ABCA1 activates Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3), which suppresses pro-inflammatory genes such as tumour necrosis factor-α . Macrophage-specific ABCA1 deficiency is associated with increased pro-inflammatory gene expression and cytokine release both in vivo in animal models and ex vivo . The potential mechanisms are ATI-5261, as an Apo A1 mimetic peptide, functions as an anti-inflammatory agent; ABCA1 functions as an anti-inflammatory receptor to suppress the expression of inflammatory factors and to be the molecular basis for the interaction between inflammation and reserve cholesterol transport . Apart from that, ABCA1 may also play an important role in regulating endothelial function [65, 66] and vascular smooth muscle cells proliferation and phenotypic changes , which are key factors that affect arterial stiffness.
Consistent with previous studies in humans [19, 20, 22], placental ABCA1 expressions were decreased in the COMT−/− mice model of PE. The ABC transporters comprise a family of functionally diverse polytopic transmembrane proteins and are able to translocate a wide variety of substrates, including amino acids, lipids, ions, peptides and drugs, across extracellular and intracellular biological membranes . In particular, ABCA1 and ABCG1 have been described to be involved in feto-maternal lipid transport and fetal lipid homeostasis . Functional loss of ABCA1 in mice causes severe placental malformation and fetal growth retardation , also emphasizing the unique role of ABCA1 in reproduction. Therefore, the decreased fetal growth in COMT−/− mice may be partially explained by the decreased levels of ABCA1 and ABCG1 in the placenta. ATI-5261 treatment significantly increased ABCA1 levels in the placenta but did not improve fetal growth in our study. The decreased placental weights and increased fetal to placental ratios by ATI-5261 treatment may indicate the improvement of placental function . We speculate that the beneficial effects of ATI-5261 on placental function may not be able to encounter other deficiencies in COMT−/− mice resulting in impaired fetal growth.
A limitation of this study is that only one dose of ATI-5261 had been examined. However, in vivo studies on ATI-5261 are limited. The effectiveness and safety during pregnancy still need further investigation. COMT−/− mice had been used as a model of PE in the present study. Currently, a number of animal models of PE exist and have facilitated the testing of pharmacological interventions that may ameliorate or prevent PE. However, none of these animal models exactly mirror the human condition and fetal outcomes and mirror the placental pathology characterized by the impaired trophoblast invasion in pregnancies complicated with PE .
This is the first study, to our knowledge, to investigate the effect of ATI-5261 treatment on arterial stiffness in a mouse model of PE. In conclusion, ATI-5261 reversed arterial stiffness at late pregnancy and early postpartum in COMT−/− mice. This important study provides crucial evidence to support the further research and development of a potential new therapy for arterial stiffness associated with PE.
ATP binding cassette transporter A1
ATP binding cassette transporter G1
Pulse wave velocity
Scavenger receptor BI
Ghulmiyyah L, Sibai B. Maternal mortality from preeclampsia/eclampsia. Semin Perinatol. 2012;36:56–9.
Vogel JP, Souza JP, Mori R, Morisaki N, Lumbiganon P, Laopaiboon M, et al. Maternal complications and perinatal mortality: findings of the World Health Organization multicountry survey on maternal and newborn health. BJOG. 2014;121(Suppl 1):76–88.
Ahmed R, Dunford J, Mehran R, Robson S, Kunadian V. Pre-eclampsia and future cardiovascular risk among women: a review. J Am Coll Cardiol. 2014;63:1815–22.
Scantlebury DC, Hayes SN. How does preeclampsia predispose to future cardiovascular disease? Curr Hypertens Rep. 2014;16:472.
Estensen ME, Remme EW, Grindheim G, Smiseth OA, Segers P, Henriksen T, et al. Increased arterial stiffness in pre-eclamptic pregnancy at term and early and late postpartum: a combined echocardiographic and tonometric study. Am J Hypertens. 2013;26:549–56.
Franklin SS, Gustin W, Wong ND, Larson MG, Weber MA, Kannel WB, et al. Hemodynamic patterns of age-related changes in blood pressure. The Framingham Heart Study. Circulation. 1997;96:308–15.
Sutton-Tyrrell K, Najjar SS, Boudreau RM, Venkitachalam L, Kupelian V, Simonsick EM, et al. Elevated aortic pulse wave velocity, a marker of arterial stiffness, predicts cardiovascular events in well-functioning older adults. Circulation. 2005;111:3384–90.
Park S, Lakatta EG. Role of inflammation in the pathogenesis of arterial stiffness. Yonsei Med J. 2012;53:258–61.
Prosser HC, Ng MK, Bursill CA. The role of cholesterol efflux in mechanisms of endothelial protection by HDL. Curr Opin Lipidol. 2012;23:182–9.
Vaisar T, Tang C, Babenko I, Hutchins P, Wimberger J, Suffredini AF, et al. Inflammatory remodeling of the HDL proteome impairs cholesterol efflux capacity. J Lipid Res. 2015;56:1519–30.
Liao S, McLachlan CS. Cholesterol efflux: does it contribute to aortic stiffening? J Cardiovasc Dev Dis. 2018;5 https://doi.org/10.3390/jcdd5020023.
Fu Y. Rate-limiting factors of cholesterol efflux in reverse cholesterol transport: acceptors and donors. Clin Exp Pharmacol Physiol. 2010;37:703–9.
Favari E, Ronda N, Adorni MP, Zimetti F, Salvi P, Manfredini M, et al. ABCA1-dependent serum cholesterol efflux capacity inversely correlates with pulse wave velocity in healthy subjects. J Lipid Res. 2013;54:238–43.
Liu D, Ji L, Tong X, Pan B, Han JY, Huang Y, et al. Human apolipoprotein A-I induces cyclooxygenase-2 expression and prostaglandin I-2 release in endothelial cells through ATP-binding cassette transporter A1. Am J Physiol Cell Physiol. 2011;301:C739–48.
Westerterp M, Bochem AE, Yvan-Charvet L, Murphy AJ, Wang N, Tall AR. ATP-binding cassette transporters, atherosclerosis, and inflammation. Circ Res. 2014;114:157–70.
Bielicki JK, Zhang H, Cortez Y, Zheng Y, Narayanaswami V, Patel A, et al. A new HDL mimetic peptide that stimulates cellular cholesterol efflux with high efficiency greatly reduces atherosclerosis in mice. J Lipid Res. 2010;51:1496–503.
Hafiane A, Bielicki JK, Johansson JO, Genest J. Apolipoprotein E derived HDL mimetic peptide ATI-5261 promotes nascent HDL formation and reverse cholesterol transport in vitro. Biochim Biophys Acta. 1842;2014:1498–512.
Zheng Y, Patel AB, Narayanaswami V, Bielicki JK. Retention of alpha-helical structure by HDL mimetic peptide ATI-5261 upon extensive dilution represents an important determinant for stimulating ABCA1 cholesterol efflux with high efficiency. Biochem Biophys Res Commun. 2013;441:71–6.
Baumann M, Korner M, Huang X, Wenger F, Surbek D, Albrecht C. Placental ABCA1 and ABCG1 expression in gestational disease: pre-eclampsia affects ABCA1 levels in syncytiotrophoblasts. Placenta. 2013;34:1079–86.
Liu L, Zhang M, Li L, Li C, Min X, Zheng M. Expression and clinical significance of ATP-binding cassette transporter 1 in serum and placental tissue in Chinese patients with preeclampsia. Gynecol Obstet Investig. 2014;78:194–200.
Liu L, Zhang M, Min X, Cai L. Low serum levels of ABCA1, an ATP-binding cassette transporter, are predictive of preeclampsia. Tohoku J Exp Med. 2015;236:89–95.
Chigusa Y, Kondoh E, Mogami H, Nishimura F, Ujita M, Kawasaki K, et al. ATP-binding cassette transporter A1 expression is decreased in preeclamptic placentas. Reprod Sci. 2013;20:891–8.
Mistry HD, Kurlak LO, Mansour YT, Zurkinden L, Mohaupt MG, Escher G. Increased maternal and fetal cholesterol efflux capacity and placental CYP27A1 expression in preeclampsia. J Lipid Res. 2017;58:1186–95.
Zheng Y, Patel AB, Narayanaswami V, Hura GL, Hang B, Bielicki JK. HDL mimetic peptide ATI-5261 forms an oligomeric assembly in solution that dissociates to monomers upon dilution. Biochemistry. 2011;50:4068–76.
Chew JL, Chua KY. Collection of mouse urine for bioassays. Lab Anim (NY). 2003;32:48–50.
Leloup AJ, Fransen P, Van Hove CE, Demolder M, De Keulenaer GW, Schrijvers DM. Applanation tonometry in mice: a novel noninvasive technique to assess pulse wave velocity and arterial stiffness. Hypertension. 2014;64:195–200.
Silswal N, Parelkar N, Andresen J, Wacker MJ. Restoration of endothelial function in Pparalpha (−/−) mice by Tempol. PPAR Res. 2015;2015:728494.
Li XM, Tang WH, Mosior MK, Huang Y, Wu Y, Matter W, et al. Paradoxical association of enhanced cholesterol efflux with increased incident cardiovascular risks. Arterioscler Thromb Vasc Biol. 2013;33:1696–705.
Favari E, Calabresi L, Adorni MP, Jessup W, Simonelli S, Franceschini G, et al. Small discoidal pre-beta1 HDL particles are efficient acceptors of cell cholesterol via ABCA1 and ABCG1. Biochemistry. 2009;48:11067–74.
Low H, Hoang A, Sviridov D. Cholesterol efflux assay. J Vis Exp. 2012;61:e3810.
Brennan LJ, Morton JS, Davidge ST. Vascular dysfunction in preeclampsia. Microcirculation. 2014;21:4–14.
Ciftci FC, Ciftci O, Gullu H, Caliskan M, Uckuyu A, Ozcimen EE. Does mild preeclampsia cause arterial stiffness and ventricular remodeling through inflammation? Ginekol Pol. 2014;85:900–7.
Goulopoulou S, Davidge ST. Molecular mechanisms of maternal vascular dysfunction in preeclampsia. Trends Mol Med. 2015;21:88–97.
Butz GM, Davisson RL. Long-term telemetric measurement of cardiovascular parameters in awake mice: a physiological genomics tool. Physiol Genomics. 2001;5:89–97.
Hefler LA, Tempfer CB, Moreno RM, O'Brien WE, Gregg AR. Endothelial-derived nitric oxide and angiotensinogen: blood pressure and metabolism during mouse pregnancy. Am J Physiol Regul Integr Comp Physiol. 2001;280:R174–82.
Chen K, Merrill DC, Rose JC. The importance of angiotensin II subtype receptors for blood pressure control during mouse pregnancy. Reprod Sci. 2007;14:694–704.
Carey LC, Rose JC. The midgestational maternal blood pressure decline is absent in mice lacking expression of the angiotensin II AT2 receptor. J Renin-Angiotensin-Aldosterone Syst. 2011;12:29–35.
Kanasaki K, Palmsten K, Sugimoto H, Ahmad S, Hamano Y, Xie L, et al. Deficiency in catechol-O-methyltransferase and 2-methoxyoestradiol is associated with pre-eclampsia. Nature. 2008;453:1117–21.
Stanley JL, Andersson IJ, Poudel R, Rueda-Clausen CF, Sibley CP, Davidge ST, et al. Sildenafil citrate rescues fetal growth in the catechol-O-methyl transferase knockout mouse model. Hypertension. 2012;59:1021–8.
Rueda-Clausen CF, Stanley JL, Thambiraj DF, Poudel R, Davidge ST, Baker PN. Effect of prenatal hypoxia in transgenic mouse models of preeclampsia and fetal growth restriction. Reprod Sci. 2014;21:492–502.
Casey ML, MacDonald PC. Characterization of catechol-O-methyltransferase activity in human uterine decidua vera tissue. Am J Obstet Gynecol. 1983;145:453–7.
Berg D, Sonsalla R, Kuss E. Concentrations of 2-methoxyoestrogens in human serum measured by a heterologous immunoassay with an 125I-labelled ligand. Acta Endocrinol (Copenh). 1983;103:282–8.
Mabjeesh NJ, Escuin D, LaVallee TM, Pribluda VS, Swartz GM, Johnson MS, et al. 2ME2 inhibits tumor growth and angiogenesis by disrupting microtubules and dysregulating HIF. Cancer Cell. 2003;3:363–75.
Fotsis T, Zhang Y, Pepper MS, Adlercreutz H, Montesano R, Nawroth PP, et al. The endogenous oestrogen metabolite 2-methoxyoestradiol inhibits angiogenesis and suppresses tumour growth. Nature. 1994;368:237–9.
Bonacasa B, Sanchez ML, Rodriguez F, Lopez B, Quesada T, Fenoy FJ, et al. 2-Methoxyestradiol attenuates hypertension and coronary vascular remodeling in spontaneously hypertensive rats. Maturitas. 2008;61:310–6.
Bourghardt J, Bergstrom G, Krettek A, Sjoberg S, Boren J, Tivesten A. The endogenous estradiol metabolite 2-methoxyestradiol reduces atherosclerotic lesion formation in female apolipoprotein E-deficient mice. Endocrinology. 2007;148:4128–32.
Barchiesi F, Jackson EK, Fingerle J, Gillespie DG, Odermatt B, Dubey RK. 2-Methoxyestradiol, an estradiol metabolite, inhibits neointima formation and smooth muscle cell growth via double blockade of the cell cycle. Circ Res. 2006;99:266–74.
Rigassi L, Barchiesi Bozzolo F, Lucchinetti E, Zaugg M, Fingerle J, Rosselli M, et al. 2-Methoxyestradiol blocks the RhoA/ROCK1 pathway in human aortic smooth muscle cells. Am J Physiol Endocrinol Metab. 2015;309:E995–1007.
Chen W, Cui Y, Zheng S, Huang J, Li P, Simoncini T, et al. 2-methoxyestradiol induces vasodilation by stimulating NO release via PPARgamma/PI3K/Akt pathway. PLoS One. 2015;10:e0118902.
Dubey RK, Jackson EK. Cardiovascular protective effects of 17beta-estradiol metabolites. J Appl Physiol (1985). 2001;91:1868–83.
Barter PJ, Nicholls S, Rye KA, Anantharamaiah GM, Navab M, Fogelman AM. Antiinflammatory properties of HDL. Circ Res. 2004;95:764–72.
Nicholls SJ, Dusting GJ, Cutri B, Bao S, Drummond GR, Rye KA, et al. Reconstituted high-density lipoproteins inhibit the acute pro-oxidant and proinflammatory vascular changes induced by a periarterial collar in normocholesterolemic rabbits. Circulation. 2005;111:1543–50.
Tabet F, Remaley AT, Segaliny AI, Millet J, Yan L, Nakhla S, et al. The 5A apolipoprotein a-I mimetic peptide displays antiinflammatory and antioxidant properties in vivo and in vitro. Arterioscler Thromb Vasc Biol. 2010;30:246–52.
Getz GS, Reardon CA. The structure/function of apoprotein A-I mimetic peptides: an update. Curr Opin Endocrinol Diabetes Obes. 2014;21:129–33.
Jain S, Khera R, Corrales-Medina VF, Townsend RR, Chirinos JA. Inflammation and arterial stiffness in humans. Atherosclerosis. 2014;237:381–90.
Patel RS, Al Mheid I, Morris AA, Ahmed Y, Kavtaradze N, Ali S, et al. Oxidative stress is associated with impaired arterial elasticity. Atherosclerosis. 2011;218:90–5.
Meng X, Qie L, Wang Y, Zhong M, Li L. Assessment of arterial stiffness affected by atorvastatin in coronary artery disease using pulse wave velocity. Clin Invest Med. 2009;32:E238.
Matsuo T, Iwade K, Hirata N, Yamashita M, Ikegami H, Tanaka N, et al. Improvement of arterial stiffness by the antioxidant and anti-inflammatory effects of short-term statin therapy in patients with hypercholesterolemia. Heart Vessel. 2005;20:8–12.
Ichihara A, Hayashi M, Koura Y, Tada Y, Kaneshiro Y, Saruta T. Long-term effects of statins on arterial pressure and stiffness of hypertensives. J Hum Hypertens. 2005;19:103–9.
Lee JY, Parks JS. ATP-binding cassette transporter AI and its role in HDL formation. Curr Opin Lipidol. 2005;16:19–25.
Zhu X, Owen JS, Wilson MD, Li H, Griffiths GL, Thomas MJ, et al. Macrophage ABCA1 reduces MyD88-dependent toll-like receptor trafficking to lipid rafts by reduction of lipid raft cholesterol. J Lipid Res. 2010;51:3196–206.
Yvan-Charvet L, Welch C, Pagler TA, Ranalletta M, Lamkanfi M, Han S, et al. Increased inflammatory gene expression in ABC transporter-deficient macrophages: free cholesterol accumulation, increased signaling via toll-like receptors, and neutrophil infiltration of atherosclerotic lesions. Circulation. 2008;118:1837–47.
Tang C, Liu Y, Kessler PS, Vaughan AM, Oram JF. The macrophage cholesterol exporter ABCA1 functions as an anti-inflammatory receptor. J Biol Chem. 2009;284:32336–43.
Yin K, Liao DF, Tang CK. ATP-binding membrane cassette transporter A1 (ABCA1): a possible link between inflammation and reverse cholesterol transport. Mol Med. 2010;16:438–49.
Vaisman BL, Demosky SJ, Stonik JA, Ghias M, Knapper CL, Sampson ML, et al. Endothelial expression of human ABCA1 in mice increases plasma HDL cholesterol and reduces diet-induced atherosclerosis. J Lipid Res. 2012;53:158–67.
Westerterp M, Tsuchiya K, Tattersall IW, Fotakis P, Bochem AE, Molusky MM, et al. Deficiency of ATP-binding cassette transporters A1 and G1 in endothelial cells accelerates atherosclerosis in mice. Arterioscler Thromb Vasc Biol. 2016;36:1328–37.
Castiglioni S, Monti M, Arnaboldi L, Canavesi M, Ainis Buscherini G, Calabresi L, et al. ABCA1 and HDL3 are required to modulate smooth muscle cells phenotypic switch after cholesterol loading. Atherosclerosis. 2017;266:8–15.
Li G, Gu HM, Zhang DW. ATP-binding cassette transporters and cholesterol translocation. IUBMB Life. 2013;65:505–12.
Stefulj J, Panzenboeck U, Becker T, Hirschmugl B, Schweinzer C, Lang I, et al. Human endothelial cells of the placental barrier efficiently deliver cholesterol to the fetal circulation via ABCA1 and ABCG1. Circ Res. 2009;104:600–8.
Christiansen-Weber TA, Voland JR, Wu Y, Ngo K, Roland BL, Nguyen S, et al. Functional loss of ABCA1 in mice causes severe placental malformation, aberrant lipid distribution, and kidney glomerulonephritis as well as high-density lipoprotein cholesterol deficiency. Am J Pathol. 2000;157:1017–29.
Hayward CE, Lean S, Sibley CP, Jones RL, Wareing M, Greenwood SL, et al. Placental adaptation: what can we learn from Birthweight:placental weight ratio? Front Physiol. 2016;7:28.
McCarthy FP, Kingdom JC, Kenny LC, Walsh SK. Animal models of preeclampsia; uses and limitations. Placenta. 2011;32:413–9.
We would like to thank Artery Therapeutics, Inc. for sharing the amino acid sequence for ATI-5261 synthesis.
This study is supported by Wenzhou Sciences Foundation (W20153389452). Shutan Liao is funded under an NHMRC Development Grant.
Availability of data and materials
The raw data supporting the findings presented in this study will be available from the corresponding author upon request.
This study was performed in accordance to the Guide for the Care and Use of Laboratory Animals published by the US NIH. All protocols were approved by the Animal Ethics Committee of Wenzhou Medical University (WZU38479–567).
Consent for publication
The authors declare that they have no competing interests.
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