PHACTR1, a pro-atherosclerotic mechanosensitive PPARgamma corepressor in endothelial cells

Background

Numerous genome-wide association studies revealed that SNPs at phosphatase and actin regulator 1 (PHACTR1) locus are strongly correlated with coronary artery disease (CAD). However, the mechanism linking these variants to CAD remains uncertain.

Purpose

We studied the biological functions and molecular mechanisms of PHACTR1 in atherosclerosis.

Methods and results

Analysis of GTEx database showed that CAD-related SNPs in PHACTR1 are cis-eQTLs for PHACTR1 in arteries. Therefore, we generated Phactr1 knockout mice and crossed them with apolipoprotein E-deficient (ApoE−/−) mice to induce atherosclerosis by high-fat/high-cholesterol (HF-HC) diet. Phactr1 deficiency significantly inhibited atherosclerosis with decreased inflammatory cell infiltration. Western blot showed that PHACTR1 was restricted to endothelial cells (ECs) in mice. Mechanistically, RNAseq of aortic ECs revealed that the major molecular function of PHACTR1 was transcriptional regulation. PPARγ/RXRα was the top transcription factor, and PPARγ target gene expression substantially increased in Phactr1−/− mice. Moreover, we generated endothelial cell specific Phactr1−/−, ApoE−/− mice and found decreased atherosclerotic plaque area in aortic sinus. In vitro, PHACTR1 associated with PPARγ and inhibited PPARγ transcriptional activity. The inhibitory effect of PHACTR1 on PPARγ required its shuttling from cytosol to nucleus triggered by disturbed flow, a well-established pro-atherosclerotic stimulus.

Conclusion

Our results identified PHACTR1 as a mechanosensitive corepressor of PPARγ in ECs to promote atherosclerosis. Endothelial PHACTR1 is a potential therapeutic target for atherosclerosis treatment.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Natural Science Foundation of China (NSFC), China Postdoctoral Science Foundation (CPSF)

Twofold improved tumor-to-brain contrast using a novel T1 relaxation-enhanced steady-state (T1RESS) MRI technique

A technique that provides more accurate cancer detection would be of great value. Toward this end, we developed T1 relaxation-enhanced steady-state (T₁RESS), a novel magnetic resonance imaging (MRI) pulse sequence that enables the flexible modulation of T1 weighting and provides the unique feature that intravascular signals can be toggled on and off in contrast-enhanced scans. T₁RESS makes it possible to effectively use an MRI technique with improved signal-to-noise ratio efficiency for cancer imaging. In a proof-of-concept study, "dark blood" unbalanced T₁RESS provided a twofold improvement in tumor-to-brain contrast compared with standard techniques, whereas balanced T₁RESS greatly enhanced vascular detail. In conclusion, T₁RESS represents a new MRI technique with substantial potential value for cancer imaging, along with a broad range of other clinical applications.

Acupuncture for menopausal symptoms in Chinese women: a systematic review

Menopause-related symptoms are common problems of middle-aged women that can seriously affect their quality of life. Menopausal hormone therapy (MHT) for climacteric symptoms is the first choice recommended by the International Menopause Society and likewise by other societies and institutions covering this field. However, non-hormonal therapies can be an alternative effective option, especially for women who are not suitable for MHT. Acupuncture is one of the most important methods. With deepening experience of the use of traditional Chinese acupuncture and moxibustion in the improvement of menopause symptoms, more clinical evidence has been obtained to support the effectiveness and safety of this treatment concept that is very often used in China. This review summarizes the evidence for effective treatment of climacteric complaints by acupuncture in recent years, shares the clinical experience of the authors of this review, all of whom head or work in units with daily large numbers of outpatients, and includes, in particular, results from studies performed in the Department of Acupuncture--Moxibustion of Tsinghua University Chuiyangliu Hospital, Beijing, China. In addition, there is a summary about the safety of acupuncture treatment in traditional Chinese medicine.

Associations of serum magnesium levels and calcium-magnesium ratios with mortality in patients with coronary artery disease

AIMS

Low magnesium (Mg) and high calcium (Ca) levels are linked to increased cardiovascular disease (CVD) risk in the general population. This prospective study assessed whether there are any independent associations of serum Mg levels and Ca-Mg ratios with mortality in patients with coronary artery disease (CAD).

METHODS

This prospective cohort study included 3380 CAD patients. Cox regression models were used to estimate associations of serum Mg and Ca-Mg ratio with risk of mortality.

RESULTS

A total of 562 deaths (331 due to CVD) were recorded during a 7.59-year (median) follow-up. Spline plots displayed U-shaped associations between serum Mg levels and Ca-Mg ratios and risk of mortality. When compared with a moderate group, adjusted hazard ratios (95% confidence intervals) for low Mg levels and high Ca-Mg ratios were 1.59 (1.30-1.95) and 1.31 (1.06-1.61) for all-cause mortality, and 1.71 (1.32-2.22) and 1.44 (1.09-1.89) for CVD mortality, respectively. There was also a tendency to increase risk of mortality in patients with high serum Mg levels and low Ca-Mg ratios. Associations of low serum Mg and high Ca-Mg ratio with risk of mortality did not change when stratified by gender, body mass index, CAD type, estimated glomerular filtration rate, use of diuretics, or history of diabetes or hypertension.

CONCLUSION

This study demonstrated that a moderate Ca-Mg ratio (range: 3.91-4.70) had the lowest mortality risk, and that low serum Mg and high Ca-Mg ratio were independent risk factors of mortality in CAD patients. Nevertheless, the optimal dose-response of Mg and Ca for mitigating CAD risk still requires further investigation.

[Consistency of ALK Ventana-D5F3 immunohistochemistry interpretation in lung adenocarcinoma among Chinese histopathologists]

Objective: To understand the consistency of ALK Ventana-D5F3 immunohistochemistry (IHC) interpretation in Chinese lung adenocarcinoma among histopathologists from different hospitals, and to recommend solution for the problems found during the interpretation of ALK IHC in real world, with the aim of the precise selection of patients who can benefit from ALK targeted therapy. Methods: This was a multicenter and retrospective study. A total of 109 lung adenocarcinoma cases with ALK Ventana-D5F3 IHC staining were collected from 31 lung cancer centers in RATICAL research group from January to June in 2018. All cases were scanned into digital imaging with Ventana iSCANcoreo Digital Slide Scanning System and scored by 31 histopathologists from different centers according to ALK binary (positive or negative) interpretation based on its manufacturer's protocol. The cases with high inconsistency rate were further analyzed using FISH/RT-PCR/NGS. Results: There were 49 ALK positive cases and 60 ALK negative cases, confirmed by re-evaluation by the specialist panel. Two cases (No. 2302 and No.2701) scored as positive by local hospitals were rescored as negative, and were confirmed to be negative by RT-PCR/FISH/NGS. The false interpretation rate of these two cases was 58.1% (18/31) and 48.4% (15/31), respectively. Six out of 31 (19.4%) pathologists got 100% accuracy. The minimum consistency between every two pathologists was 75.8%.At least one pathologist gave negative judgement (false negative) or positive judgement (false positive) in the 49 positive or 60 negative cases, accounted for 26.5% (13/49), 41.7% (25/60), respectively, with at least one uncertainty interpretation accounted for 31.2% (34/109). Conclusion: There are certain heterogeneities and misclassifications in the real world interpretation of ALK-D5F3 IHC test, which need to be guided by the oncoming expert consensus based on the real world data.

Comparison of microRNAs in adipose and muscle tissue from seven indigenous Chinese breeds and Yorkshire pigs

Elucidation of the pig microRNAome is essential for interpreting functional elements of the genome and understanding the genetic architecture of complex traits. Here, we extracted small RNAs from skeletal muscle and adipose tissue, and we compared their expression levels between one Western breed (Yorkshire) and seven indigenous Chinese breeds. We detected the expression of 172 known porcine microRNAs (miRNAs) and 181 novel miRNAs. Differential expression analysis found 92 and 12 differentially expressed miRNAs in adipose and muscle tissue respectively. We found that different Chinese breeds shared common directional miRNA expression changes compared to Yorkshire pigs. Some miRNAs differentially expressed across multiple Chinese breeds, including ssc-miR-129-5p, ssc-miR-30 and ssc-miR-150, are involved in adipose tissue function. Functional enrichment analysis revealed that the target genes of the differentially expressed miRNAs are associated mainly with signaling pathways rather than metabolic and biosynthetic processes. The miRNA-target gene and miRNA-phenotypic traits networks identified many hub miRNAs that regulate a large number of target genes or phenotypic traits. Specifically, we found that intramuscular fat content is regulated by the greatest number of miRNAs in muscle tissue. This study provides valuable new candidate miRNAs that will aid in the improvement of meat quality and production.

Simplified LC-MS/MS method for quantification of IG-105, a novel tubulin ligand, and its application to the pharmacokinetic study in rats at the anticancer effective dose

IG-105, N-(2, 6-dimethoxypyridine-3-yl)-9-methylcarbazole-3-sulfonamide, a novel carbazole sulfonamide, shows a potent anticancer activity in a variety of human tumor cells in vitro and in vivo. In the present study, a rapid and convenient liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed and applied to the pharmacokinetic study of IG-105 in rats. Chromatographic separation was accomplished on a C₁₈ column using an isocratic mobile phase of acetonitrile-water-acetic acid (56:44:0.2, v/v/v). The ion transitions of IG-105 and combretastatin A4 (internal standard) in selected reaction monitoring mode were m/z 398→154 and m/z 317→286, respectively. The assay exhibited good linearity over the range of 2-512 ng/mL. Intra- and inter-day precisions were within 8.2 %, and the accuracies ranged from -6.0 to 3.7 %. The extraction recoveries were higher than 90 %, and the matrix effects were negligible. All quality control samples were stable at different storage conditions. The validated LC-MS/MS method was successfully applied to a preclinical pharmacokinetic study of IG-105 in rats after a single oral dose of 100, 250, or 1000 mg/kg which showed tumor growth inhibition activity. The absorption of IG-105 was proved to be rapid but saturated to a certain extent into the blood circulation, from where it was distributed and eliminated gradually.

Mitochondrial ALDH2 protects against lipopolysaccharide-induced myocardial contractile dysfunction by suppression of ER stress and autophagy

Lipopolysaccharide (LPS), an essential component of outer membrane of the Gram-negative bacteria, plays a pivotal role in myocardial anomalies in sepsis. Recent evidence depicted an essential role for mitochondrial aldehyde dehydrogenase (ALDH2) in cardiac homeostasis. This study examined the effect of ALDH2 on endotoxemia-induced cardiac anomalies. Echocardiographic, cardiac contractile and intracellular Ca²⁺ properties were examined. Our results indicated that LPS impaired cardiac contractile function (reduced fractional shortening, LV end systolic diameter, peak shortening, maximal velocity of shortening/relengthening, prolonged relengthening duration, oxidation of SERCA, and intracellular Ca²⁺ mishandling), associated with ER stress, inflammation, O₂^- production, increased autophagy, CAMKKβ, phosphorylated AMPK and suppressed phosphorylation of mTOR, the effects of which were significantly attenuated or negated by ALDH2. LPS promoted early endosomal formation (as evidenced by RAB4 and RAB5a), apoptosis and necrosis (MTT and LDH) while decreasing late endosomal formation (RAB7 and RAB 9), the effects were reversed by ALDH2. In vitro study revealed that LPS-induced SERCA oxidation, autophagy and cardiac dysfunction were abrogated by ALDH2 activator Alda-1, the ER chaperone TUDCA, the autophagy inhibitor 3-MA, or the AMPK inhibitor Compound C. The beneficial effect of Alda-1 against LPS was nullified by AMPK activator AICAR or rapamycin. CAMKKβ inhibition failed to rescue LPS-induced ER stress. Tunicamycin-induced cardiomyocyte dysfunction was ameliorated by Alda-1 and autophagy inhibition, the effect of which was abolished by rapamycin. These data suggested that ALDH2 protected against LPS-induced cardiac anomalies via suppression of ER stress, autophagy in a CAMKKβ/AMPK/mTOR-dependent manner.

[Efficacy and safety of anti-interleukin-5 therapy in patients with asthma: systematic reviews]

Objective: To evaluate the efficacy and safety of anti-Interleukin-5 therapy in patients with asthma. Methods: Data were collected from PubMed, E-Mbase, Springer, Ovid, Cochrane Library, ClinicalTrials.gov, CNKI and Wanfang database (-Feb 2017). Bibliographies of the retrieved articles were checked and analyzed. Results: Twenty publications involving a total of 6 406 patients were used in the analysis, including 23 randomly controlled trials (RCTs) which compared anti-interleukin 5 monoclonal antibody with placebo. Pooled analyses showed that anti-interleukin 5 monoclonal antibody significantly reduced exacerbation risk [RR=0.66, 95%CI(0.59, 0.73)], increased FEV(1)[MD=0.10, 95%CI(0.07, 0.13)] and FEV(1)% predicted [MD=3.90, 95%CI(1.86, 5.95)], and improved the scores on the Asthma Quality of Life Questionnaire (AQLQ) [MD=0.24, 95%CI(0.16, 0.32)]. Anti-interleukin 5 monoclonal antibody was also associated with significantly decreased risk of adverse events than placebo[OR=0.71, 95%CI(0.58, 0.87)]. Conclusion: Anti-interleukin 5 monoclonal antibody reduces the risk of exacerbations and improves quality of life in patients with asthma, and is tolerated well.

ALDH2 mediates the dose-response protection of chronic ethanol against endothelial senescence through SIRT1/p53 pathway

Aldehyde dehydrogenase 2 (ALDH2) plays essential roles in drinking-associated diseases or effects. As we have previously reported, ALDH2 mediates acute ethanol-induced eNOS activation in vitro. However, whether chronic ethanol treatment has a dose-response endothelial protection, as well as the possible mediating role of ALDH2 involved, is unclear. Here, we show that appropriate dose of ethanol preserved the expression and activity of ALDH2 and eNOS, and alleviated senescence-associated phenotypes in human aortic endothelial cells. Furthermore, ALDH2 deficiency impairs the dose-response protection of ethanol against endothelial senescence by promoting the accumulation of 4-HNE, the formation of 4-HNE-SIRT1 protein adducts and the subsequent decrease in SIRT1-dependent p53 deacetylation. Collectively, our data indicate that ALDH2 mediates the protection of appropriate ethanol by modulating SIRT1/p53-dependent endothelial senescence.

[The efficacy and safety of coil embolization of septal branch in the treatment of patients with obstructive hypertrophic cardiomyopathy]

Objective: To observe the clinical efficacy and safety of coil embolization of septal branch in the treatment of obstructive hypertrophic cardiomyopathy (HOCM). Methods: Eighteen patients with HOCM hospitalized in our department from September 2014 to October 2016 were enrolled in this study. There were 12 males and 6 females in this cohort and the age of patients ranged from 22 to 64 years old. Left ventricular outflow tract gradient (LVOTG) was derived from echocardiographic apical five-chamber view at pre-operation and at 48 hours and 6 months post operation. 24-hour Holter ECG examination was performed to assess the ventricular tachycardia, atrial fibrillation, atrioventricular block at 3 days and 6 months after the interventional operation. Routine ECG and creatine kinase-MB (CK-MB) examination were performed at pre-operation, at 6, 24 and 48 hours post operation. Cardiac troponin T (cTnT) was detected at pre-operation, at 24, 48 hours and 6 days post operation. The clinical symptoms (including chest tightness, chest pain, shortness of breath, syncope) and NYHA classification were assessed at 1, 6 months after the operation by telephone follow-up or outpatient clinic visit. Results: The average preoperative LVOTG detected by cardiac catheter was 103.6 (92.0, 115.0) mmHg (1 mmHg=0.133 kPa) , and the average LVOTG significantly reduced to 44.3 (41.6, 47.2) mmHg immediately after operation (P<0.01). The average ventricular septal thickness at 48 hours (19.2±3.1) mm and 6 months (17.8±2.8) mm after operation tended to be lower than the preoperative ventricular septal thickness ((20.4±3.5) mm, P>0.05). The echocardiographic derived average LVOTG at 48 hours and 6 months after operation was 42.9 (41.1, 45.5) and 39.1 (37.5, 41.0) mmHg, which were significant lower than the preoperative average LVOTG (94.3 (88.5, 101.8) mmHg, both P<0.01). LVOTG at 6 months after operation was significantly lower than that at 48 hours after the operation (P<0.05). The NYHA classification at 6 months after operation was significantly improved compared to pre-operation NYHA classification (P<0.01). During and after the operation, there was no complete atrioventricular block and ventricular tachycardia, no patient developed anterior wall and inferior myocardial infarction. Only one patient experienced transient left bundle branch block. During the 6 months following-up, there was no death, syncope, chest pain, palpitations, shortness of breath, paroxysmal dyspnea and/or lower extremity edema, ventricular tachycardia, atrioventricular block and atrial fibrillation, complete atrioventricular block and ventricular arrhythmia. Conclusion: The coil embolization of septal branch is effective and safe for the treatment of patients with HOCM.