The effects of LXR agonist GW3965 on vascular reactivity and inflammation in hypertensive rat aorta

Pharmacogenetic association of the NR1H3 promoter variant with antihypertensive response among patients with hypertension: A longitudinal study

Background: The genetic factors in assessing therapeutic efficacy and predicting antihypertensive drug response are unclear. Therefore, this study aims to identify the associations between variants and antihypertensive drug response. Methods: A longitudinal study including 1837 hypertensive patients was conducted in Northern China and followed up for a median 2.24 years. The associations of 11 candidate variants with blood pressure changes in response to antihypertensive drugs and with the risk of cardiovascular events during the follow-up were examined. The dual-luciferase assay was carried out to assess the effect of genetic variants on gene transcriptional activity. Results: The variant rs11039149A>G in the promoter of nuclear receptor subfamily 1 group H member 3 (NR1H3) was associated with the change in systolic blood pressure (ΔSBP) in response to calcium channel blockers (CCBs) monotherapy. Patients carrying rs11039149AG genotype showed a significant increase of systolic blood pressure (SBP) at follow-up compared with AA carriers, and the difference of ΔSBP between AG and AA carriers was 5.94 mm Hg (95%CI: 2.09-9.78, p = 0.002). In 1,184 patients with CCBs therapy, SBP levels decreased in AA carriers, but increased in AG carriers, the difference of ΔSBP between AG and AA carriers was 8.04 mm Hg (95%CI: 3.28-12.81, p = 0.001). Further analysis in 359 patients with CCBs monotherapy, the difference of ΔSBP between AG and AA carriers was 15.25 mm Hg (95%CI: 6.48-24.02, p = 0.001). However, there was no significant difference in ΔSBP between AG and AA carriers with CCBs multitherapy. The rs11039149A>G was not associated with the cardiovascular events incidence during the follow-up. Additionally, transcriptional factor forkhead box C1 (FOXC1) bound to the NR1H3 promoter containing rs11039149A and significantly increased the transcriptional activity, while rs11039149 A to G change led to a loss-of-function and disabled FOXC1 binding. For the other 10 variants, associations with blood pressure changes or risk of cardiovascular events were not observed. Conclusion: Hypertensive patients with rs11039149AG genotype in the NR1H3 gene have a significant worse SBP control in response to CCBs monotherapy compared with AA carriers. Our findings suggest that the NR1H3 gene might act as a promising genetic factor to affect individual sensitivity to antihypertensive drugs.

ROS Suppression by Egg White Hydrolysate in DOCA-Salt Rats—An Alternative Tool against Vascular Dysfunction in Severe Hypertension

This study aimed to evaluate the potential for lowering blood pressure and beneficial effects on mesenteric resistance arteries (MRA) and conductance vessels (aorta) produced by dietary supplementation of an egg white hydrolysate (EWH) in rats with severe hypertension induced by deoxycorticosterone plus salt treatment (DOCA-salt), as well as the underlying mechanisms involved. The DOCA-salt model presented higher blood pressure, which was significantly reduced by EWH. The impaired acetylcholine-induced relaxation and eNOS expression observed in MRA and aorta from DOCA-salt rats was ameliorated by EWH. This effect on vessels (MRA and aorta) was related to the antioxidant effect of EWH, since hydrolysate intake prevented the NF-κB/TNFα inflammatory pathway and NADPH oxidase-induced reactive oxygen species (ROS) generation, as well as the mitochondrial source of ROS in MRA. At the plasma level, EWH blocked the higher ROS and MDA generation by DOCA-salt treatment, without altering the antioxidant marker. In conclusion, EWH demonstrated an antihypertensive effect in a model of severe hypertension. This effect could be related to its endothelium-dependent vasodilator properties mediated by an ameliorated vessel’s redox imbalance and inflammatory state.

Pregnane X Receptor‒4β-Hydroxycholesterol Axis in the Regulation of Overweight- and Obesity-Induced Hypertension

Background Mechanisms mediating hypertensive effects of overweight and obesity have not been fully elucidated. We showed previously that activation of pregnane X receptor (PXR) by rifampicin elevates 24-hour blood pressure (BP) and plasma 4β-hydroxycholesterol (4βHC), agonist for liver X receptor (LXR). Methods and Results In combined "PXR activation data set" (n=62) of 4 clinical trials, 1 week rifampicin dosing increased office systolic BP (SBP) by 3.1 mm Hg, DBP 1.8 mm Hg, and mean arterial pressure 2.2 mm Hg in comparison with placebo (P<0.01). Plasma 4βHC had negative correlation with SBP both in rifampicin (r=-0.46, P=0.0002) and placebo (r=-0.45, P=0.0003) arms, although 4βHC was elevated >3-fold by rifampicin. In "non-intervention data set" (n=102) of patients with obesity and healthy volunteers (body mass index, 19.2-55.2 kg/m²), 4βHC had negative correlations (P<0.00001) with office SBP (r=-0.51), diastolic BP (r=-0.50), and mean arterial pressure (r=-0.54). Lean women had higher 4βHC than men, with increasing weight repressing 4βHC (r=-0.62, P<0.00001) in both sexes. In multiple linear regression analysis, the only statistically significant predictor for SBP was 4βHC. Six-day PXR agonist dosing elevated SBP in rats (n=7-8/group). PXR activation elevated 4βHC and after PXR agonist was withdrawn and elevated 4βHC was left to act alone, SBP was reduced on days 7 to 14 in comparison with control rats. Conclusions PXR activation elevates SBP. Elevated circulating 4βHC lowers SBP in rats, and higher 4βHC is an independent predictor of lower SBP in humans. PXR-4βHC-LXR is novel BP-regulating pathway deregulated in overweight and obesity by repressed 4βHC, with implications for sex-specific BP regulation. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT00985270, NCT01293422, NCT01690104, NCT02329405, and NCT01330251.

Gynura procumbens ethanol extract improves vascular dysfunction by suppressing inflammation in postmenopausal rats fed a high-fat diet

CONTEXT

Gynura procumbens (Lour.) Merr. (Asteraceae) has been reported to have various pharmacological activities including anti-inflammatory effects.

OBJECTIVE

This study sought to determine whether Gynura procumbens (GP) could improve vascular reactivity by suppressing inflammation in postmenopausal rats fed with five-times heated palm oil (5HPO) diet.

MATERIALS AND METHODS

Forty-eight female Sprague-Dawley rats were randomly divided into sham [non-ovariectomized; grouped as control, GP extracts (250 and 500 mg/kg), atorvastatin (ATV, 10 mg/kg)] and postmenopausal (PM) groups [ovariectomized rats fed with 5HPO; grouped as PM, GP extracts (250 and 500 mg/kg) and ATV (10 mg/kg)]. Each group (n = 6) was either supplemented with GP extract or ATV orally once daily for 6 months.

RESULTS

In comparison with the untreated PM group, 250 and 500 mg/kg GP supplementation to PM groups reduced the systolic blood pressure (103 ± 2.7, 86 ± 2.4 vs. 156 ± 7.83 mmHg, p < 0.05), intima-media thickness (101.28 ± 3.4, 93.91 ± 2.93 vs. 143.78 ± 3.31 µM), vasoconstriction percentage induced by phenylephrine (102.5%, 88.3%, vs. 51.8%), sICAM-1 (0.49, 0.26 vs. 0.56 pg/mL) and sVCAM-1 (0.39, 0.25 vs. 0.45 pg/mL). GP extract supplementation increased vasorelaxation percentage induced by acetylcholine (78.4% vs. 47.3%) and sodium nitroprusside (84.2% vs. 53.7%), increased changes in plasma nitric oxide level (1.25%, 1.31% vs. 1.9%), and suppressed the elevation of TNF-α (0.39 vs. 1.02 pg/mL), IL-6 (0.43 vs. 0.77 pg/mL) and CRP (0.29 vs. 0.69 ng/mL) in the PM groups.

CONCLUSIONS

GP extract might improve vascular dysfunction by suppressing the inflammatory response, consequently preventing blood pressure elevation.

Untangling the Cooperative Role of Nuclear Receptors in Cardiovascular Physiology and Disease

The heart is the first organ to acquire its physiological function during development, enabling it to supply the organism with oxygen and nutrients. Given this early commitment, cardiomyocytes were traditionally considered transcriptionally stable cells fully committed to contractile function. However, growing evidence suggests that the maintenance of cardiac function in health and disease depends on transcriptional and epigenetic regulation. Several studies have revealed that the complex transcriptional alterations underlying cardiovascular disease (CVD) manifestations such as myocardial infarction and hypertrophy is mediated by cardiac retinoid X receptors (RXR) and their partners. RXRs are members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors and drive essential biological processes such as ion handling, mitochondrial biogenesis, and glucose and lipid metabolism. RXRs are thus attractive molecular targets for the development of effective pharmacological strategies for CVD treatment and prevention. In this review, we summarize current knowledge of RXR partnership biology in cardiac homeostasis and disease, providing an up-to-date view of the molecular mechanisms and cellular pathways that sustain cardiomyocyte physiology.

Selection and evaluation of quality markers from Yinlan capsule and its LXRα-mediated therapy for hyperlipidemia

BACKGROUND

The selection of active compounds for the quality evaluation of traditional Chinese medicine (TCM), specifically complex formulas, remains a challenge for researchers, as components selected as indexes usually have no clear relation with the therapeutic effects of interest. As a suggested resolution, quality control markers (Q-markers) showed good perspective for discriminating numerous compounds found for specific efficacies. In the presented study, the components of the Yinlan (YL) capsule, a TCM patent formula comprising four ingredients, were evaluated and selected for their lipid regulatory effects using principles for Q-marker selection.

PURPOSE

The mechanism of TCM therapeutic effects involves several pathways and targets that combine to become an integrated action in the body. Therefore, it is assumed that specific compounds in YL should have good affinity for related targets and obvious effects (both up- and downregulating). Thus, a series of experiments, including cytobiology, animal-based pharmacodynamics, computer-assisted drug design, conventional content determination and pharmacokinetics, would be helpful for the selection and final confirmation of Q-markers.

METHODS

The capsule was first administered to Wistar mice fed a high-fat diet and tested for their triglycerides (TG) and total cholesterol (TC) values to evaluate the effectiveness of YL. Then, liver tissue was extracted for gene expression. According to the results, the compounds in YL with good affiliation were selected and determined using UHPLC-MS-MS, and those with adequate results in the capsule were chosen as Q-marker candidates. Finally, pharmacokinetics research was performed; the candidates with desirable metabolite and bioavailability parameters were confirmed as Q-markers of YL.

RESULTS

YL capsule was capable of lowering TG and TC levels. For target selection, the expression of LXR mRNA increased significantly at all three tested dosages. Downstream genes, such as LCAT, CYP7A1, and ABCA1, and intestinal FXR mRNA also showed significant increases in expression. For screening of the Q-marker candidates, 5 compounds were selected according to abovementioned results. The pharmacokinetics research demonstrated that the rats exploited lupeol and ginsenoside Rb3 in a desirable pattern with adequate bioavailability, which confirmed their roles as lipid regulatory Q-markers.

CONCLUSION

The YL capsule was demonstrated to have obvious lipid regulatory effects, which are mainly exerted by targeting LXR and its related pathway. Lupeol and ginsenoside Rb3 were validated as Q-markers that represent the anti-hyperlipidemia activity of the capsule.