The gut microbe-derived metabolite trimethylamine-N-oxide induces aortic valve fibrosis via PERK/ATF-4 and IRE-1α/XBP-1s signaling in vitro and in vivo.

BACKGROUND AND AIMS: The gut microbe-derived metabolite trimethylamine-N-oxide (TMAO) has been implicated in the development of cardiovascular fibrosis. Endoplasmic reticulum (ER) stress occurs after the dysfunction of ER and its structure. The three signals PERK/ATF-4, IRE-1α/XBP-1s and ATF6 are activated upon ER stress. Recent reports have suggested that the activation of PERK/ATF-4 and IRE-1α/XBP-1s signaling contributes to cardiovascular fibrosis. However, whether TMAO mediates aortic valve fibrosis by activating PERK/ATF-4 and IRE-1α/XBP-1s signaling remains unclear. METHODS: Human aortic valve interstitial cells (AVICs) were isolated from aortic valve leaflets. PERK IRE-1α, ATF-4, XBP-1s and CHOP expression, and production of collagen Ⅰ and TGF-ß1 were analyzed following treatment with TMAO. The role of PERK/ATF-4 and IRE-1α/XBP-1s signaling pathways in TMAO-induced fibrotic formation was determined using inhibitors and small interfering RNA. RESULTS: Diseased valves produced greater levels of ATF-4, XBP-1, collagen Ⅰ and TGF-ß1. Interestingly, diseased cells exhibited augmented PERK/ATF-4 and IRE-1α/XBP-1s activation after TMAO stimulation. Inhibition and silencing of PERK/ATF-4 and IRE-1α/XBP-1s each resulted in enhanced suppression of TMAO-induced fibrogenic activity in diseased cells. Mice treated with dietary choline supplementation had substantially increased TMAO levels and aortic valve fibrosis, which were reduced by 3,3-dimethyl-1-butanol (DMB, an inhibitor of trimethylamine formation) treatment. Moreover, a high-choline and high-fat diet remodeled the gut microbiota in mice. CONCLUSIONS: TMAO promoted aortic valve fibrosis through activation of PERK/ATF-4 and IRE-1α/XBP-1s signaling pathways in vitro and in vivo. Modulation of diet, gut microbiota, TMAO, PERK/ATF-4 and IRE1-α/XBP-1s may be a promising approach to prevent aortic valve fibrosis.

Serum Klotho Modifies the Associations of 25-Hydroxy Vitamin D With All-Cause and Cardiovascular Mortality.

BACKGROUND: The association between 25-hydroxyvitamin D and mortality remains controversial. Klotho, a biomarker of vitamin D activation and metabolism, may play a key role in this association. However, it is unclear whether the association between vitamin D deficiency and mortality risk is modified by klotho levels. Therefore, this study investigated the joint association of serum 25-hydroxyvitamin D [25(OH)D] and klotho with mortality risk in American community-dwelling adults. METHODS: A total of 9870 adults from the National Health and Nutrition Examination Survey (2007-2016) were included in our study. Mortality data were ascertained by linking participants to National Death Index records. Cox proportional hazards models were used to assess the association among serum 25(OH)D, serum klotho, and all-cause and cardiovascular disease (CVD) mortality. RESULTS: We found a significant interaction between klotho and serum 25(OH)D in all-cause mortality (P = .028). With klotho > 848.4 pg/mL (risk threshold on mortality), no significant all-cause and CVD mortality risk was observed at any level of serum 25(OH)D. However, with klotho < 848.4 pg/mL, a significant all-cause and CVD mortality risk was observed with serum 25(OH)D < 50 nmol/L [hazards ratio (HR), 1.36; 95% confidence interval (CI), 1.10-1.69; HR, 1.78; 95% CI, 1.16-3.45) and serum 25(OH)D of continuous variable (HR, 0.98; 95% CI, .97-.99; HR, 0.98; 95% CI, .98-.99). In addition, vitamin D metabolism disruption accessed by the combination of decreasing serum 25(OH)D (<50 nmol/L) and klotho (<848.4 pg/mL) was associated with significant all-cause mortality (HR, 1.48; 95% CI, 1.11-1.96) and CVD mortality (HR, 2.36; 95% CI, 1.48-3.75). CONCLUSIONS: Vitamin D-associated mortality risk is observed only with concurrently decreasing klotho, indicating that vitamin D metabolism dysfunction increases the risk of mortality. Klotho levels could help predict long-term mortality outcomes and thus may be useful concurrently for guiding vitamin D supplementation therapy decision-making in populations with vitamin D deficiency.

Identification of Novel Phenotypes Correlated with CKD: A Phenotype-Wide Association Study.

Background: A comprehensive understanding of phenotypes related to CKD will facilitate the identification and management of CKD. We aimed to panoramically test and validate associations between multiple phenotypes and CKD using a phenotype-wide association study (PheWAS). Methods: 15,815 subjects from cross-sectional cohorts of the National Health and Nutrition Examination Survey (1999-2006) were randomly 50:50 split into training and testing sets. CKD was defined as eGFR < 60 mL/min/1.73m2. We performed logistic regression analyses between each of 985 phenotypes with CKD in the training set (false discovery rate < 1%) and validated in the testing set (false discovery rate < 1% ). Random forest (RF) model, Nagelkerke's Pseudo-R2, and the area under the receiver operating characteristic (AUROC) were used to validate the identified phenotypes. Results: We identified 18 phenotypes significantly related to CKD, among which retinol, red cell distribution width (RDW), and C-peptide were less researched. The top 5 identified phenotypes were blood urea nitrogen (BUN), homocysteine (HCY), retinol, parathyroid hormone (PTH), and osmolality in RF importance ranking. Besides, BUN, HCY, PTH, retinol, and uric acid were the most important phenotypes based on Pseudo-R2. AUROC of the RF model was 0.951 (full model) and 0.914 (top 5 phenotypes). Conclusion: Our study demonstrated associations between multiple phenotypes with CKD from a holistic view, including 3 novel phenotypes: retinol, RDW, and C-peptide. Our findings provided valid evidence for the identification of novel biomarkers for CKD.

Toward a panoramic perspective of the association between environmental factors and cardiovascular disease: An environment-wide association study from National Health and Nutrition Examination Survey 1999-2014.

OBJECTIVES: An environment-wide association study (EWAS) may be useful to comprehensively test and validate associations between environmental factors and cardiovascular disease (CVD) in an unbiased manner. APPROACH AND RESULTS: Data from National Health and Nutrition Examination Survey (1999-2014) were randomly 50:50 spilt into training set and testing set. CVD was ascertained by a self-reported diagnosis of myocardial infarction, coronary heart disease or stroke. We performed multiple linear regression analyses associating 203 environmental factors and 132 clinical phenotypes with CVD in training set (false discovery rate < 5%) and significant factors were validated in the testing set (P < 0.05). Random forest (RF) model was used for multicollinearity elimination and variable importance ranking. Discriminative power of factors for CVD was calculated by area under the receiver operating characteristic (AUROC). Overall, 43,568 participants with 4084 (9.4%) CVD were included. After adjusting for age, sex, race, body mass index, blood pressure and socio-economic level, we identified 5 environmental variables and 19 clinical phenotypes associated with CVD in training and testing dataset. Top five factors in RF importance ranking were: waist, glucose, uric acid, and red cell distribution width and glycated hemoglobin. AUROC of the RF model was 0.816 (top 5 factors) and 0.819 (full model). Sensitivity analyses reveal no specific moderators of the associations. CONCLUSION: Our systematic evaluation provides new knowledge on the complex array of environmental correlates of CVD. These identified correlates may serve as a complementary approach to CVD risk assessment. Our findings need to be probed in further observational and interventional studies.

Higenamine Combined with [6]-Gingerol Suppresses Doxorubicin-Triggered Oxidative Stress and Apoptosis in Cardiomyocytes via Upregulation of PI3K/Akt Pathway.

Sini decoction is a well-known formula of traditional Chinese medicine, which has been used to treat cardiovascular disease for many years. Previously, we demonstrated that Sini decoction prevented doxorubicin-induced heart failure in vivo. However, its active components are still unclear. Thus, we investigated the active components of Sini decoction and their cardioprotective mechanisms in the in vitro neonatal rat cardiomyocytes and H9c2 cell line models of doxorubicin-induced cytotoxicity. Our results demonstrated that treatment with higenamine or [6]-gingerol increased viability of doxorubicine-injured cardiomyocytes. Moreover, combined use of higenamine and [6]-gingerol exerted more profound protective effects than either drug as a single agent, with effects similar to those of dexrazoxane, a clinically approved cardiac protective agent. In addition, we found that treatment with doxorubicin reduced SOD activity, increased ROS generation, enhanced MDA formation, induced release of LDH, and triggered the intrinsic mitochondria-dependent apoptotic pathway in cardiomyocytes, which was inhibited by cotreatment of higenamine and [6]-gingerol. Most importantly, the cytoprotection of higenamine plus [6]-gingerol could be abrogated by LY294002, a PI3K inhibitor. In conclusion, combination of higenamine and [6]-gingerol exerts cardioprotective effect against doxorubicin-induced cardiotoxicity through activating the PI3K/Akt signaling pathway. Higenamine and [6]-gingerol may be the active components of Sini decoction.

Electroacupuncture treatment of chronic insomniacs.

BACKGROUND: Due to the quick rhythm of life and work pressure, more and more people suffer from sleep quality problems. In this study, we investigated the effect of electroacupuncture on sleep quality of chronic insomniacs and the safety of electroacupuncture therapy. METHODS: Four courses of electroacupuncture treatment were applied to 47 patients. With pre-treatment and post-treatment self-control statistical method, Pittsburgh sleep quality index (PSQI) scores were used for evaluating sleep quality. Polysomnogram was used for detecting insomniacs' changes in sleep architecture. The safety of electroacupuncture was evaluated by monitoring the self-designed adverse events and side effects during treatment and post-treatment. RESULTS: Electroacupuncture considerably improved insomniacs' sleep quality and social function during the daytime. Electroacupuncture had certain repairing effect on the disruption in sleep architecture. At the same time, electroacupuncture prolonged slow wave sleep (SWS) time and relatively rapid eye movement sleep (REM sleep) time. There was no hangover, addiction or decrements in vigilance during the daytime (incidence rate was 0). However, insomnia rebound rate was about 23% within one month. CONCLUSIONS: These results suggest that electroacupuncture has beneficial effect on sleep quality improvement in the patients with chronic insomnia, which may be associated with repairing sleep architecture, reconstructing sleep continuity, as well as prolonging SWS time and REM sleep time. Electroacupuncture treatment for chronic insomnia is safe. Therefore, electroacupuncture therapy could be a promising avenue of treatment for chronic insomnia.