Differential changes in TGF-β/BMP signaling pathway in the right ventricular myocardium of newborns with hypoplastic left heart syndrome

Sex-biased TGFβ signalling in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare cardiovascular disorder leading to pulmonary hypertension and, often fatal, right heart failure. Sex differences in PAH are evident, which primarily presents with a female predominance and increased male severity. Disturbed signalling of the transforming growth factor-β (TGFβ) family and gene mutations in the bone morphogenetic protein receptor 2 (BMPR2) are risk factors for PAH development, but how sex-specific cues affect the TGFβ family signalling in PAH remains poorly understood. In this review, we aim to explore the sex bias in PAH by examining sex differences in the TGFβ signalling family through mechanistical and translational evidence. Sex hormones including oestrogens, progestogens, and androgens, can determine the expression of receptors (including BMPR2), ligands, and soluble antagonists within the TGFβ family in a tissue-specific manner. Furthermore, sex-related genetic processes, i.e. Y-chromosome expression and X-chromosome inactivation, can influence the TGFβ signalling family at multiple levels. Given the clinical and mechanistical similarities, we expect that the conclusions arising from this review may apply also to hereditary haemorrhagic telangiectasia (HHT), a rare vascular disorder affecting the TGFβ signalling family pathway. In summary, we anticipate that investigating the TGFβ signalling family in a sex-specific manner will contribute to further understand the underlying processes leading to PAH and likely HHT.

Hypoplastic Left Heart Syndrome: Signaling & Molecular Perspectives, and the Road Ahead

Hypoplastic left heart syndrome (HLHS) is a lethal congenital heart disease (CHD) affecting 8-25 per 100,000 neonates globally. Clinical interventions, primarily surgical, have improved the life expectancy of the affected subjects substantially over the years. However, the etiological basis of HLHS remains fundamentally unclear to this day. Based upon the existing paradigm of studies, HLHS exhibits a multifactorial mode of etiology mediated by a complicated course of genetic and signaling cascade. This review presents a detailed outline of the HLHS phenotype, the prenatal and postnatal risks, and the signaling and molecular mechanisms driving HLHS pathogenesis. The review discusses the potential limitations and future perspectives of studies that can be undertaken to address the existing scientific gap. Mechanistic studies to explain HLHS etiology will potentially elucidate novel druggable targets and empower the development of therapeutic regimens against HLHS in the future.

Anti-Mullerian hormone and cardiometabolic status: a systematic review

BACKGROUND

To summarise the relationship between Anti-mullerian hormone (AMH) levels and cardiometabolic status in different populations.

METHODS

PubMed, Scopus, and Embase were searched for retrieving observational studies published up to February 2022 investigating the relationship between AMH level and cardiometabolic status.

RESULTS

Of 3,643 studies retrieved from databases, a total of 37 observational studies were included in this review. The majority of the included studies revealed an inverse association between AMH and lipid profiles, including triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), and a positive correlation with high-density lipoprotein (HDL). While some studies have revealed a significant inverse association between AMH and glycemic parameters, including fasting plasma glucose (FPG), fasting insulin, and HOMA-IR, others found no such relationships. There is also an inconsistency among studies regarding the association of AMH with adiposity indices and blood pressure. Evidence indicates a significant association between AMH and some vascular markers, such as intima-media thickness and coronary artery calcification. Of 3 studies evaluating the relationship between AMH and cardiovascular events, two studies showed an inverse relationship between AMH levels and cardiovascular (CVD), whereas another study showed no significant association.

CONCLUSIONS

The results of this systematic review suggest that serum AMH levels can be associated with CVD risk. This may provide new insight into the use of AMH concentrations as a predictive marker for assessing the risk of cardiovascular disease, although more well-design longitudinal studies are still necessary for this area. Future studies on this topic will hopefully provide an opportunity to run a meta-analysis; it will increase the persuasiveness of this interpretation.

Anti-Müllerian hormone concentration is associated with central adiposity and reproductive hormones in expectant fathers

OBJECTIVE

The role of the anti-Müllerian hormone (AMH) as an indicator of physical and reproductive health in men is unclear. We assessed the relationships between AMH and follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and metabolic parameters, in a cohort of expectant fathers.

DESIGN

ORIGINS Project prospective cohort study.

SETTING

Community-dwelling men.

PARTICIPANTS

Partners of pregnant women attending antenatal appointments.

MAIN OUTCOME MEASURES

Serum AMH, FSH, LH, testosterone, and metabolic parameters.

RESULTS

In 485 expectant fathers, median age 33 years, median AMH was 40 pmol/L (quartiles 29, 56). AMH was inversely correlated with FSH, age, and body mass index (BMI) (correlation coefficients: -.32, -.24, and -.17 respectively). The age association was nonlinear, with peak AMH between 20 and 30 years, a decline thereafter, and somewhat steady levels after 45 years. The inverse association of AMH with FSH was log-linear and independent of age and BMI (β: -.07, SE: 0.01, p < .001). AMH was inversely correlated with waist circumference and directly associated with sex hormone-binding globulin. Testosterone was moderately correlated with AMH (correlation coefficient: .09, β: .011, SE: 0.004, p = .014): this association was mediated by an inverse relationship with BMI (mediated proportion 0.49, p < .001).

CONCLUSIONS

In reproductively active men, lower AMH is a biomarker for advancing age, and for poorer metabolic and reproductive health. The inverse association between AMH and FSH is independent of age and BMI, whereas the association of AMH and testosterone is mediated via BMI. The utility of AMH to predict reproductive and cardiometabolic outcomes in men warrants further investigation.

Circulating anti-Müllerian hormone levels and markers of subclinical cardiovascular disease in middle-aged and older men

CONTEXT

Recent research suggests that higher circulating anti-Müllerian hormone (AMH) levels are associated with less frequent occurrence of (subclinical) cardiovascular disease (CVD) in women, but evidence in men is limited.

OBJECTIVE

We investigated whether circulating AMH levels are associated with measures of subclinical CVD in middle-aged and older men.

DESIGN

Prospective cohort study with a median follow-up time of 8.7 years. Serum AMH was measured at baseline. We assessed both cross-sectional and longitudinal associations using linear regression models adjusted for confounders.

SETTING

Dutch middle-aged and older men from the community.

PARTICIPANTS

394 men (aged 40-80 years) with an available AMH measurement at baseline.

MAIN OUTCOME MEASURES

At baseline (2001-2002): carotid intima-media thickness (CIMT), pulse wave velocity (PWV), abdominal aortic diameter, and Framingham risk score (FRS) predictions. At follow-up (2010-2011): CIMT, mean carotid aortic plaque score, PWV, and FRS predictions. All outcomes were transformed using rank-based inverse normal transformation to meet the normality assumption.

RESULTS

Higher AMH levels were associated with lower CIMT at baseline (β = -0.04; 95%CI = 0.07, -0.01), but not with the other measures of subclinical CVD at baseline. Longitudinal analyses suggested that higher baseline AMH levels were associated with lower mean plaque scores at follow-up (β = -0.03, 95%CI = -0.07, 0.00), but not with the other follow-up outcomes.

CONCLUSIONS

Our results suggest that AMH is associated with current CIMT and future carotid aortic plaque burden in men, implying that circulating AMH levels are potentially associated with local atherosclerosis rather than with total aortic stiffness.

A pilot investigation of the tricuspid valve annulus in newborns with hypoplastic left heart syndrome

Objective

Hypoplastic left heart syndrome (HLHS) is a congenital disease characterized by an underdevelopment of the anatomical components inside the left heart. Approximately 30% of newborns with HLHS will develop tricuspid regurgitation, and it is currently unknown how the valve annulus mechanics and geometry are associated with regurgitation. Thus, we present an engineering mechanics-based analysis approach to quantify the mechanics and geometry of the HLHS-afflicted tricuspid valve (TV), using 4-dimensional echocardiograms.

Methods

Infants born with HLHS (n = 8) and healthy newborns (n = 4) had their TVs imaged, and the data were imported to 3D Slicer. The annular curves were defined at 5 points in the cardiac cycle. The geometry and deformation (strain) of the TV annulus were calculated to elucidate the mechanics of this critical structure and to compare them between neonates with and without HLHS.

Results

For the annular geometry, HLHS-afflicted newborns had significantly larger annular circumferences (20%-30%) and anteroposterior diameters (35%-45%) than the healthy patients. From a biomechanics' perspective, the HLHS patients had significantly smaller strains in the anterior segments (–0.1 ± 2.6%) during end-diastolic and end-isovolumetric relaxation (1.7 ± 3.0%) compared with the healthy counterparts (–13.3 ± 2.9% and 6.8 ± 0.9%, respectively).

Conclusions

The image-based analysis presented in this study may provide novel insights into the geometric and mechanistic differences in the TV annulus between the healthy and HLHS newborns. Future longitudinal studies of the biomechanics of TV annulus and other subvalvular structures may inform our understanding of the initiation and development of tricuspid regurgitation and the design of optimal repairs in this challenging population.

Anti-Müllerian hormone and vascular dysfunction in women with chronic kidney disease

Young women with chronic kidney disease (CKD) have disproportionately increased risk of cardiovascular mortality. Reduced anti-Müllerian hormone (AMH) is linked to poor cardiovascular outcomes in the general population, but whether AMH is associated with increased cardiovascular risk in the high-risk CKD population is unknown. This study examined the association between AMH and vascular function, validated markers of cardiovascular risk, in women with CKD. An exploratory cross-sectional study was performed in 47 young women with CKD. Laboratory measurements of AMH were collected. Using standardized protocols, endothelial function was measured with brachial artery flow-mediated dilation and hyperemic velocity time integral. Arterial stiffness was measured with aortic augmentation index and pulse wave velocity. Multivariate linear regression analyses were utilized to evaluate the association between AMH levels and each measure of vascular health. Forty women (36 ± 7 years) with non-dialysis-dependent CKD and 7 women (38 ± 6 years) with dialysis-dependent CKD participated. AMH levels were inversely associated with age (p = 0.01) but not associated with eGFR (p = 0.59) or dialysis status (p = 0.97). AMH was associated with brachial artery flow-mediated dilation (R2  = 0.21 [p = 0.03]) and aortic augmentation index (R2  = 0.20 [p = 0.04]) in the non-dialysis-dependent participants, and with aortic augmentation index in all participants (R2  = 0.18 [p = 0.03]). No association between AMH and any measure of vascular function was demonstrated in the dialysis-dependent participants. AMH levels are associated with impaired vascular function in young women with CKD and may be an important marker of future cardiovascular risk. Further investigation into this female-specific cardiovascular risk factor is warranted in this high-risk population.

Anti-mullerian hormone attenuates insulin resistance and systemic inflammation in old obese C57BL/6 male mice

Purpose

Epidemiological studies show that Anti-mullerian hormone (AMH) is inversely correlated with age, obesity-related diseases, and all-cause mortality in men. To further investigate the role of AMH in aging and obesity, we studied the effect of AMH treatment on the inflammatory and metabolic parameters and weight in old male C57BL/6 mice.

Method

Thirty-six old male C57BL/6 mice (18 month-old) were either on the High-Fat Diet (HFD) or Normal Diet (ND). When obesity occurred in the HFD group, each group was divided into two subgroups; AMH-treated (ND^+AMH and HFD^+AMH) or controls (ND and HFD). The AMH subgroup received 15 ng/gbw of recombinant AMH injection every 48 h in four weeks. Then, serum AMH, CRP, fasting glucose, fasting insulin, and HOMA-IR were measured and analyzed.

Results

AMH injection decreased CRP level (HFD =622.86±25.73, HFD^+AMH =543.2±24.99 ng/ml, p= 0.003), fasting insulin (HFD=1.50± 0.34, HFD^+AMH =0.8±0.25 ng/ml, p=0.006) and HOMA-IR (HFD=12.76± 2.88, HFD^+AMH =7.06±2.31, p=0.008) in the obese old mice comparison with control. In ND group, just CRP levels dropped following AMH injection (ND=451.24±20.61, ND^+AMH= 326.8±23.76 ng/ml; p=0.001). Accelerated weight gain was observed in HFD^+AMH compared with the HFD subgroup (p<0.05).

Conclusions

In conclusion, increasing the circulating level of AMH could subside the systemic inflammation through decreasing CRP levels regardless of diet type and enhance insulin sensitivity in old obese mice. It can also lead to higher weight gain, without inflammation, in old obese male mice who are on an HFD.

Functional Activity of Recombinant Forms of Amh and Synergistic Action with Fsh in European Sea Bass Ovary

Although anti-Müllerian hormone (AMH) has classically been correlated with the regression of Müllerian ducts in male mammals, involvement of this growth factor in other reproductive processes only recently come to light. Teleost is the only gnathostomes that lack Müllerian ducts despite having amh orthologous genes. In adult teleost gonads, Amh exerts a role in the early stages of germ cell development in both males and females. Mechanisms involving the interaction of Amh with gonadotropin- and growth factor-induced functions have been proposed, but our overall knowledge regarding Amh function in fish gonads remains modest. In this study, we report on Amh actions in the European sea bass ovary. Amh and type 2 Amh receptor (Amhr2) are present in granulosa and theca cells of both early and late-vitellogenic follicles and cannot be detected in previtellogenic ovaries. Using the Pichia pastoris system a recombinant sea bass Amh has been produced that is endogenously processed to generate a 12–15 kDa bioactive mature protein. Contrary to previous evidence in lower vertebrates, in explants of previtellogenic sea bass ovaries, mature Amh has a synergistic effect on steroidogenesis induced by the follicle-stimulating hormone (Fsh), increasing E2 and cyp19a1a levels.

Exploration and validation of hub genes and pathways in the progression of hypoplastic left heart syndrome via weighted gene co-expression network analysis

Background

Despite significant progress in surgical treatment of hypoplastic left heart syndrome (HLHS), its mortality and morbidity are still high. Little is known about the molecular abnormalities of the syndrome. In this study, we aimed to probe into hub genes and key pathways in the progression of the syndrome.

Methods

Differentially expressed genes (DEGs) were identified in left ventricle (LV) or right ventricle (RV) tissues between HLHS and controls using the GSE77798 dataset. Then, weighted gene co-expression network analysis (WGCNA) was performed and key modules were constructed for HLHS. Based on the genes in the key modules, protein–protein interaction networks were conducted, and hub genes and key pathways were screened. Finally, the GSE23959 dataset was used to validate hub genes between HLHS and controls.

Results

We identified 88 and 41 DEGs in LV and RV tissues between HLHS and controls, respectively. DEGs in LV tissues of HLHS were distinctly involved in heart development, apoptotic signaling pathway and ECM receptor interaction. DEGs in RV tissues of HLHS were mainly enriched in BMP signaling pathway, regulation of cell development and regulation of blood pressure. A total of 16 co-expression network were constructed. Among them, black module (r = 0.79 and p value = 2e−04) and pink module (r = 0.84 and p value = 4e−05) had the most significant correlation with HLHS, indicating that the two modules could be the most relevant for HLHS progression. We identified five hub genes in the black module (including Fbn1, Itga8, Itga11, Itgb5 and Thbs2), and five hub genes (including Cblb, Ccl2, Edn1, Itgb3 and Map2k1) in the pink module for HLHS. Their abnormal expression was verified in the GSE23959 dataset.

Conclusions

Our findings revealed hub genes and key pathways for HLHS through WGCNA, which could play key roles in the molecular mechanism of HLHS.

Anti-Müllerian Hormone Concentrations Are Inversely Associated With Subclinical Atherosclerosis in Premenopausal Women

Anti-Müllerian hormone (AMH), which is secreted by granulosa cells of late preantral and small antral follicles, is a marker of ovarian reserve. The association of ovarian reserve with subclinical atherosclerosis in women of reproductive age is currently unknown. We primary investigated whether AMH levels are associated with markers of subclinical atherosclerosis in healthy, normally menstruating women. In this cross-sectional study, vascular structure and function were assessed by measurement of carotid and femoral intima–media thickness (IMT), flow-mediated dilation, carotid–femoral pulse wave velocity and augmentation index. Lipid profile and serum AMH concentrations were also measured. Seventy premenopausal women, aged 32.7 ± 6.5 years, were included. Mean AMH levels were lower in smokers than in non-smokers and negatively associated with total cholesterol (TC) levels. An inverse association between mean AMH concentrations and femoral and carotid IMT in all segments was observed. No correlation with other markers of subclinical atherosclerosis or established cardiovascular (CV) risk factors was found. After multivariable adjustment, the association between AMH concentrations and combined carotid IMT or carotid bulb IMT remained significant. In conclusion, in healthy, normally ovulating women, AMH concentrations are negatively associated with subclinical atherosclerosis indices and TC levels, independently of established CV risk factors.

Is the low AMH level associated with the risk of cardiovascular disease in obese pregnants?

Our aim was to investigate whether Antimullerian Hormone (AMH), complete blood count (CBC), Homeostasis model assessment (HOMA-IR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and weight gain have any diagnostic value for the prediction of cardiovascular disease (CVD) in obese and non-obese pregnant patients. A prospective, case-control study was carried out, including 187 patients (93 obese, and 94 non-obese). CVD risk for each patient was evaluated according to the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA). A multivariate logistic regression model was used to identify the independent risk factors of CVD in obese and non-obese patients. The obese patients had significantly lower levels of AMH when compared to the non-obese ones (p = .002). Insulin, HOMA-IR, HbA1c, and SBP were significantly higher in obese patients than non-obese ones (p < .001, p < .001 and p = .001, respectively). Age, SBP, and decreased AMH levels had significantly associated with risk factors of CVD in the obese group (p = .001, p = .002, and p = .049, respectively). Our study suggests that decreased AMH levels, increased age, and SBP are associated with CVD in obese patients. AMH may be used to evaluate CVD risk in advanced aged, obese patients.IMPACT STATEMENTWhat is already known on this subject? Obesity is one of the most common medical complications of pregnancy. Obesity increases maternal complications such as preeclampsia, caesarean rate, cardiovascular disease, obesity, and diabetes after pregnancy; and neonatal complications including macrosomia, hypoglycaemia, hyperbilirubinemia, delivery trauma, shoulder dystocia, and adult-onset obesity, and diabetes. Obese patients have lower serum AMH levels.What the results of this study add? A significant relationship between AMH levels and CVD risk in obese pregnant women was observed.What are the implications of these findings for clinical practice and/or further research? Based on this finding, we concluded that decreased AMH levels are predictive for CVD in obese pregnant women.

Association of Anti-Mullerian Hormone with C-Reactive Protein in Men

While serum anti-mullerian hormone (AMH) levels are inversely associated with all-cause mortality in men, the underlying mechanisms are unclear. Elevated levels of inflammation, also associated with all-cause mortality, and may be the link between AMH and mortality. Hence, we examined the association of AMH with serum c-reactive protein (CRP), a biomarker of inflammation, in men. We included men ≥20 years from the National Health and Nutrition Examination Survey (1999–2004). We used survey weight-adjusted linear regression to examine the association between AMH and CRP without and with adjustment for age, race, body mass index (BMI), smoking, hypertension, diabetes, cholesterol, glomerular filtration rate (GFR), testosterone, androstenedione, and sex hormone binding globulin. Of the 949 men, 212 (22%) were elderly, 493 (52%) Caucasian, 254 (27%) current smokers, 100 (10%) diabetics, and 312 (33%) had hypertension. Mean (SD) AMH was 8.4 (7.2) ng/mL and median (IQR) CRP level was 0.17 (3) mg/L. Using linear regression, each 10 ng/mL rise in AMH was associated with 0.09 mg/dL (95%CI = −0.14 to −0.03; p = 0.002) decrease before and 0.08 mg/dL (95%CI = −0.13 to −0.02; p = 0.004) decrease in CRP after adjusting for potential confounders. Similarly, men in the highest quartile of AMH had significantly lower CRP compared to those in the lowest quartile (unadjusted difference = −0.19 mg/dL; 95%CI = −0.31 to −0.06; p = 0.006, adjusted difference = −0.16 mg/dL; 95%CI = −0.3 to −0.01; p = 0.035). We found an independent, robust, and inverse association between CRP and AMH in men. Effect of AMH on mortality may be through amelioration of inflammation.

miR-486 is modulated by stretch and increases ventricular growth

Perturbations in biomechanical stimuli during cardiac development contribute to congenital cardiac defects such as hypoplastic left heart syndrome (HLHS). This study sought to identify stretch-responsive pathways involved in cardiac development. miRNA-Seq identified miR-486 as being increased in cardiomyocytes exposed to cyclic stretch in vitro. The right ventricles (RVs) of patients with HLHS experienced increased stretch and had a trend toward higher miR-486 levels. Sheep RVs dilated from excessive pulmonary blood flow had 60% more miR-486 compared with control RVs. The left ventricles of newborn mice treated with miR-486 mimic were 16.9%-24.6% larger and displayed a 2.48-fold increase in cardiomyocyte proliferation. miR-486 treatment decreased FoxO1 and Smad signaling while increasing the protein levels of Stat1. Stat1 associated with Gata-4 and serum response factor (Srf), 2 key cardiac transcription factors with protein levels that increase in response to miR-486. This is the first report to our knowledge of a stretch-responsive miRNA that increases the growth of the ventricle in vivo.

Anti-Müllerian Hormone Levels and Cardiometabolic Disturbances by Weight Status Among Men in the 1999 to 2004 National Health and Nutrition Examination Survey

Context

Serum anti-Müllerian hormone level (AMH) and body mass index may be jointly associated with cardiometabolic risk.

Objectives

Examine the contribution of AMH to cardiometabolic disturbances by weight status among US adult men.

Design

Cross-sectional analysis using data from the 1999 to 2004 waves of the National Health and Nutrition Examination Survey.

Setting

Multistage probability sampling of the noninstitutionalized US population.

Participants

US men aged ≥18 years. Final analytic sample sizes ranged from 517 to 1063 participants.

Main Outcome and Exposure Measures

Cardiometabolic disturbances (metabolic syndrome and its components, insulin resistance, diabetes, and chronic inflammation) and AMH were obtained from trained staff and nurses in a mobile examination center or during in-home visits.

Results

AMH was directly associated with insulin resistance among obese men [OR 1.08 (95% CI 1.00, 1.15); P = 0.046; N = 146], whereas AMH was inversely associated with waist circumference (WC) among obese men [OR 0.95 (95% CI 0.91, 0.99); P = 0.049; N = 146]. An inverse relationship was also observed between categorical AMH and diabetes status [medium vs low AMH; OR 0.19 (95% CI 0.043, 0.84); P = 0.030; N = 145] among obese men, with a strong inverse relationship also detected among overweight men [high vs low AMH; OR 0.011 (95% CI 0.0004, 0.27); P = 0.007; N = 193]. An inverse relationship between continuous AMH and diabetes [OR 0.75 (95% CI: 0.59, 0.93); P = 0.011; N = 193] was also detected among overweight men.

Conclusions

AMH was associated with specific cardiometabolic risk factors, including WC, diabetes status, and insulin resistance, in overweight and obese US men.

Levels of anti-Müllerian hormone in premenopausal women with the antiphospholipid syndrome and its association with the risk of clinical complications

Objective

The study aims to investigate the ovarian reserve in premenopausal women with antiphospholipid syndrome (APS) and to evaluate whether it is associated with cumulative organ damage or the risk of clinical complications.

Methods

This single-center study was conducted in 23 premenopausal female patients (10 with primary APS and 13 with secondary APS) and 24 healthy volunteers. Serum anti-Müllerian hormone (AMH) levels were measured by enzyme-linked immunoassay. Disease-specific organ damage (DIAPS score) and the risk of clinical complications (aGAPSS score) were additionally evaluated in APS patients.

Results

Serum AMH levels were similar in APS patients (median 6.06, interquartile range 4.31–7.54 ng/ml) and in controls (4.87, 2.64–6.40 ng/ml; P = 0.116), and no differences were observed between the primary (6.60, 5.49–8.88 ng/ml) and secondary (6.06, 3.91–7.30 ng/ml; P = 0.532) forms of the syndrome. In individuals with APS, serum AMH levels correlated inversely with the aGAPSS score (rho–0.421, 95% confidence intervals −0.716 to −0.001; P = 0.045), while no associations were observed with the DIAPS score (rho–0.001, −0.423 to 0.422; P = 0.996).

Conclusions

Ovarian reserve is not reduced in premenopausal women with APS. In addition, serum AMH levels may reflect the risk of APS-related clinical complications but not the burden of disease-specific organ damage.

Serum alanine aminotransferase levels and all-cause mortality

BACKGROUND AND OBJECTIVES

Studies have examined the relationship between serum alanine aminotransferase (ALT) and mortality with inconsistent results. Our aims were to examine the association of normal range serum ALT with mortality, to explore a nonlinear relationship between ALT and mortality, and to investigate whether age modifies this relationship.

STUDY

We used the continuous National Health and Nutrition Examination Survey (NHANES) from 1999 to 2010. Vital status of the participants was obtained by probabilistic matching between NHANES and the National Death Index. Cox proportional models were used to examine the relationship with and without adjustment for age, sex, race, BMI, hypertension, diabetes, alcohol use, serum triglycerides, prescription drug use, and glomerular filtration rate, and accounting for the sampling methodology of NHANES. Nonlinear relationship was examined using spline (single knot at 17 U/l) regression. Interaction terms were used to examine effect modification by age.

RESULTS

Higher serum ALT was associated with lower all-cause mortality [adjusted hazard ratio (HR)/ALT increment=0.98, 95% confidence interval (CI)=0.97-0.99]; however, this relationship was nonlinear and present only until 17 U/l (adjusted HR/ALT increment=0.93, 95% CI=0.91-0.95) and not thereafter. Age modified the relationship between ALT and mortality; elderly patients (>64 years) had a 6% lower adjusted mortality risk than younger (<35 years) participants (HR/ALT increment=0.94, 95% CI=0.91-0.96; interaction P<0.001).

CONCLUSION

Increase in serum ALT within the normal range is initially associated with lower mortality, but has no effect after 17 U/l. The elderly show a significantly larger decrease in mortality with an increase in ALT than younger individuals. The mechanisms underlying this relationship need further exploration.

Anti-Müllerian Hormone Trajectories Are Associated With Cardiovascular Disease in Women: Results From the Doetinchem Cohort Study

BACKGROUND

Earlier age at menopause is widely considered to be associated with an increased risk of cardiovascular disease. However, the underlying mechanisms of this relationship remain undetermined. Indications suggest that anti-Müllerian hormone (AMH), an ovarian reserve marker, plays a physiological role outside of the reproductive system. Therefore, we investigated whether longitudinal AMH decline trajectories are associated with an increased risk of cardiovascular disease (CVD) occurrence.

METHODS

This study included 3108 female participants between 20 and 60 years of age at baseline of the population-based Doetinchem Cohort. Participants completed ≥1 of 5 consecutive quinquennial visits between 1987 and 2010, resulting in a total follow-up time of 20 years. AMH was measured in 8507 stored plasma samples. Information on total CVD, stroke, and coronary heart disease was obtained through a hospital discharge registry linkage. The association of AMH trajectories with CVD was quantified with joint modeling, with adjustment for age, smoking, oral contraceptive use, body mass index, menopausal status, postmenopausal hormone therapy use, diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, and glucose levels.

RESULTS

By the end of follow-up, 8.2% of the women had suffered from CVD, 4.9% had suffered from coronary heart disease, and 2.6% had experienced a stroke. After adjustment, each ng/mL lower _logAMH level was associated with a 21% higher risk of CVD (hazard ratio, 1.21; 95% confidence interval, 1.07-1.36) and a 26% higher risk of coronary heart disease (hazard ratio, 1.25; 95% confidence interval, 1.08-1.46). Each additional ng/mL/year decrease of _logAMH was associated with a significantly higher risk of CVD (hazard ratio, 1.46; 95% confidence interval, 1.14-1.87) and coronary heart disease (hazard ratio, 1.56; 95% confidence interval, 1.15-2.12). No association between AMH and stroke was found.

CONCLUSIONS

These results indicate that AMH trajectories in women are independently associated with CVD risk. Therefore, we postulate that the decline of circulating AMH levels may be part of the pathophysiology of the increased cardiovascular risk of earlier menopause. Confirmation of this association and elucidation of its underlying mechanisms are needed to place these results in a clinical perspective.

Serum anti-mullerian hormone and all-cause mortality in men

Several studies have examined an association of anti-mullerian hormone to various risk factors for mortality, however, to the best of our knowledge, no study has reported a direct relationship between anti-mullerian hormone and all-cause mortality. Therefore, we examined the relationship between baseline anti-mullerian hormone levels and subsequent all-cause mortality in men during median follow-up of 9.4 (range = 0-13) years. We used the continuous National Health and Nutrition Examination Surveys from 1999-2004 combined with National Death Index for vital status information through December 2011. Cox proportional hazard models were fit to estimate hazard ratios for all-cause mortality. Models were adjusted for age, ethnic background, body mass index, hypertension, diabetes, smoking status, c-reactive protein, total cholesterol, estimated glomerular filtration rate, serum estradiol, testosterone, sex hormone binding globulin, and androstenedione. Of the 989 men, 30 % were older than 65 years, 51 % were Caucasians, 33 % had hypertension, 27 % were active smokers, and 11 % had diabetes. Mean serum anti-mullerian hormone level of the population was 7.2 (6.3) ng/mL. During the 8943 person-years of follow-up, 164 (17 %) men died. In unadjusted analysis, each unit increase in serum anti-mullerian hormone level was associated with a 13 % lower risk of death (HR = 0.87; 95 %CI = 0.83-0.92). In multivariable models, the inverse association between serum anti-mullerian hormone levels and mortality remained significant (HR = 0.94; 95 %CI = 0.90-0.98) and was independent of confounding variables. Similarly, individuals in the highest quartile had significantly lower risk of death as compared to individuals in the lowest quartile (unadjusted HR = 0.13, 95 %CI = 0.07-0.25; adjusted HR = 0.36, 95 %CI = 0.16-0.81). We found an independent and inverse association between serum anti-mullerian hormone levels and all-cause mortality in men. The mechanism underlying this association is unknown. Further studies are needed to validate our findings in men and to examine this association in women.

The association of low ovarian reserve with cardiovascular disease risk: a cross-sectional population-based study

STUDY QUESTION

Is there a relationship between serum anti-Müllerian hormone (AMH) level and cardiovascular disease (CVD) risk in premenopausal women?

SUMMARY ANSWER

There are indications that premenopausal women with very low ovarian reserve may have an unfavorable CVD risk profile.

WHAT IS KNOWN ALREADY

Age at menopause is frequently linked to CVD occurrence. AMH is produced by ovarian antral follicles and provides a measure of remaining ovarian reserve Literature on whether AMH is related to CVD risk is still scarce and heterogeneous.

STUDY DESIGN, SIZE, DURATION

Cross-sectional study in 2338 women (age range of 20-57 years) from the general population, participating in the Doetinchem Cohort Study between 1993 and 1997.

PARTICIPANTS/MATERIALS, SETTING, METHODS

CVD risk was compared between 2338 premenopausal women in different AMH level-categories, with adjustment for confounders. CVD risk was assessed through levels of systolic and diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol and glucose, in addition to a summed score of CVD risk factors. Among other factors, analyses were corrected for smoking, oral contraceptive use and BMI.

MAIN RESULTS AND THE ROLE OF CHANCE

The relationship of serum AMH levels with CVD risk factor outcomes was nonlinear. Women with AMH levels <0.16 µg/l had 0.11 (95% confidence intervals (CIs) 0.01; 0.21) more metabolic risk factors compared with women with AMH levels ≥0.16 µg/l. There was no association of individual risk factor levels with AMH levels, besides a tendency towards lower total cholesterol levels of 0.11 mmol/l (95% CI -0.23; 0.01) in women with AMH levels <0.002 µg/l compared with women with AMH levels ≥0.16 µg/l. Although not statistically significant, these effect sizes were larger in women below 40 years of age.

LIMITATIONS, REASONS FOR CAUTION

Causality and temporality of the studied association cannot be addressed here. Moreover, the clinical and statistical significance of the results of this exploratory study should be interpreted with caution due to the absence of adjustment for multiple statistical testing.

WIDER IMPLICATIONS OF THE FINDINGS

This population-based study supports previous findings that premenopausal women with very low AMH levels may have an increased CVD risk. It lays the groundwork for future research to focus on this group of women. Longitudinal studies with more sensitive AMH assays may furthermore help better understand the implications of these results.

STUDY FUNDING/COMPETING INTEREST

No financial support was received for this research or manuscript. The Doetinchem Cohort Study is conducted and funded by the Dutch National Institute for Public Health and the Environment F.J.M.B. has received fees and grant support from Merck Serono, Gedeon Richter, Ferring BV and Roche.

TRIAL REGISTRATION NUMBER

N/A.

Electrical and mechanical stimulation of cardiac cells and tissue constructs

The field of cardiac tissue engineering has made significant strides over the last few decades, highlighted by the development of human cell derived constructs that have shown increasing functional maturity over time, particularly using bioreactor systems to stimulate the constructs. However, the functionality of these tissues is still unable to match that of native cardiac tissue and many of the stem-cell derived cardiomyocytes display an immature, fetal like phenotype. In this review, we seek to elucidate the biological underpinnings of both mechanical and electrical signaling, as identified via studies related to cardiac development and those related to an evaluation of cardiac disease progression. Next, we review the different types of bioreactors developed to individually deliver electrical and mechanical stimulation to cardiomyocytes in vitro in both two and three-dimensional tissue platforms. Reactors and culture conditions that promote functional cardiomyogenesis in vitro are also highlighted. We then cover the more recent work in the development of bioreactors that combine electrical and mechanical stimulation in order to mimic the complex signaling environment present in vivo. We conclude by offering our impressions on the important next steps for physiologically relevant mechanical and electrical stimulation of cardiac cells and engineered tissue in vitro.

A novel variation of GDF3 in Chinese Han children with a broad phenotypic spectrum of non-syndromic CHDs

BACKGROUND

The GDF3 gene plays a fundamental role in embryonic morphogenesis. Recent studies have indicated that GDF3 plays a previously unrecognised role in cardiovascular system development. Non-syndromic CHDs might be a clinically isolated manifestation of GDF3 mutations. The purpose of the present study was to identify potential pathological mutations in the GDF3 gene in Chinese children with non-syndromic CHDs, and to gain insight into the aetiology of non-syndromic CHDs.

METHODS

A total of 200 non-syndromic CHDs patients and 202 normal control patients were sampled. There were two exons of the human GDF3 gene amplified using polymerase chain reaction. The polymerase chain reaction products were purified and directly sequenced.

RESULTS

One missense mutation (c.C635T, p.Ser212 Leu, phenotype: isolated muscular ventricular septal defect) was found that has not been reported previously.

CONCLUSIONS

To the best of our knowledge, this is the first study to investigate the role of the GDF3 gene in non-syndromic CHDs. Our results expand the spectrum of mutations associated with CHDs and first suggest the potentially disease-related GDF3 gene variant in the pathogenesis of CHDs.

Anti-Müllerian hormone is a gonadal cytokine with two circulating forms and cryptic actions

Anti-Müllerian hormone (AMH) is a multi-faceted gonadal cytokine. It is present in all vertebrates with its original function in phylogeny being as a regulator of germ cells in both sexes, and as a prime inducer of the male phenotype. Its ancient functions appear to be broadly conserved in mammals, but with this being obscured by its overt role in triggering the regression of the Müllerian ducts in male embryos. Sertoli and ovarian follicular cells primarily release AMH as a prohormone (proAMH), which forms a stable complex (AMHN,C) after cleavage by subtilisin/kexin-type proprotein convertases or serine proteinases. Circulating AMH is a mixture of proAMH and AMHN,C, suggesting that proAMH is activated within the gonads and putatively by its endocrine target-cells. The gonadal expression of the cleavage enzymes is subject to complex regulation, and the preliminary data suggest that this influences the relative proportions of proAMH and AMHN,C in the circulation. AMH shares an intracellular pathway with the bone morphogenetic protein (BMP) and growth differentiation factor (GDF) ligands. AMH is male specific during the initial stage of development, and theoretically should produce male biases throughout the body by adding a male-specific amplification of BMP/GDF signalling. Consistent with this, some of the male biases in neuron number and the non-sexual behaviours of mice are dependent on AMH. After puberty, circulating levels of AMH are similar in men and women. Putatively, the function of AMH in adulthood maybe to add a gonadal influence to BMP/GDF-regulated homeostasis.

Cyclic stretch of embryonic cardiomyocytes increases proliferation, growth, and expression while repressing Tgf-β signaling

Perturbed biomechanical stimuli are thought to be critical for the pathogenesis of a number of congenital heart defects, including Hypoplastic Left Heart Syndrome (HLHS). While embryonic cardiomyocytes experience biomechanical stretch every heart beat, their molecular responses to biomechanical stimuli during heart development are poorly understood. We hypothesized that biomechanical stimuli activate specific signaling pathways that impact proliferation, gene expression and myocyte contraction. The objective of this study was to expose embryonic mouse cardiomyocytes (EMCM) to cyclic stretch and examine key molecular and phenotypic responses. Analysis of RNA-Sequencing data demonstrated that gene ontology groups associated with myofibril and cardiac development were significantly modulated. Stretch increased EMCM proliferation, size, cardiac gene expression, and myofibril protein levels. Stretch also repressed several components belonging to the Transforming Growth Factor-β (Tgf-β) signaling pathway. EMCMs undergoing cyclic stretch had decreased Tgf-β expression, protein levels, and signaling. Furthermore, treatment of EMCMs with a Tgf-β inhibitor resulted in increased EMCM size. Functionally, Tgf-β signaling repressed EMCM proliferation and contractile function, as assayed via dynamic monolayer force microscopy (DMFM). Taken together, these data support the hypothesis that biomechanical stimuli play a vital role in normal cardiac development and for cardiac pathology, including HLHS.

Reducing endoglin activity limits calcineurin and TRPC-6 expression and improves survival in a mouse model of right ventricular pressure overload

BACKGROUND

Right ventricular (RV) failure is a major cause of mortality worldwide and is often a consequence of RV pressure overload (RVPO). Endoglin is a coreceptor for the profibrogenic cytokine, transforming growth factor beta 1 (TGF-β1). TGF-β1 signaling by the canonical transient receptor protein channel 6 (TRPC-6) was recently reported to stimulate calcineurin-mediated myofibroblast transformation, a critical component of cardiac fibrosis. We hypothesized that reduced activity of the TGF-β1 coreceptor, endoglin, limits RV calcineurin expression and improves survival in RVPO.

METHODS AND RESULTS

We first demonstrate that endoglin is required for TGF-β1-mediated calcineurin/TRPC-6 expression and up-regulation of alpha-smooth muscle antigen (α-SMA), a marker of myofibroblast transformation, in human RV fibroblasts. Using endoglin haploinsufficient mice (Eng(+/-)) we show that reduced endoglin activity preserves RV function, limits RV fibrosis, and attenuates activation of the calcineurin/TRPC-6/α-SMA pathway in a model of angio-obliterative pulmonary hypertension. Next, using Eng(+/-) mice or a neutralizing antibody (Ab) against endoglin (N-Eng) in wild-type mice, we show that reduced endoglin activity improves survival and attenuates RV fibrosis in models of RVPO induced by pulmonary artery constriction. To explore the utility of targeting endoglin, we observed a reversal of RV fibrosis and calcineurin levels in wild-type mice treated with a N-Eng Ab, compared to an immunoglobulin G control.

CONCLUSION

These data establish endoglin as a regulator of TGF-β1 signaling by calcineurin and TRPC-6 in the RV and identify it as a potential therapeutic target to limit RV fibrosis and improve survival in RVPO, a common cause of death in cardiac and pulmonary disease.

Hypoplastic left heart syndrome - unresolved issues

Hypoplastic left heart syndrome (HLHS) is one of the most challenging congenital heart defects. At present, it is expected that - at best - 70% of newborns with HLHS will reach adulthood. This review addresses the problems of right ventricular (RV) failure and insufficient growth of pulmonary vasculature in these patients. In order to further improve long-term prognosis translational research to control RV function, growth of pulmonary arteries and progress in chronic circulatory support are clearly needed to provide a further improvement for adults with HLHS.

Serum anti-Mullerian hormone (AMH) levels correlate with infrarenal aortic diameter in healthy older men: is AMH a cardiovascular hormone?

Anti-Müllerian hormone (AMH) is a gonadal hormone present in the blood in men and pre-menopausal women. AMH regulates male sexual differentiation but has no putative function in adulthood. In recent studies, high AMH levels are associated with absence of cardiovascular disease in men and smaller atherosclerotic burden in monkeys. Mechanistically, AMH has downstream convergence with known regulators of the cardiovascular system, while the specific receptor for AMH is present in murine aorta and the human heart. Our primary objective was to examine whether AMH levels in healthy men correlated with the physical characteristics of their aorta. Our secondary aim was to document whether men with distinct vascular disorders expressed different levels of AMH. Serum AMH assayed by ELISA in 153 men (54-93 years) free from vascular disease inversely correlated with the ultrasonographic diameters of the distal- (r=-0.22, P=0.006) and mid-infrarenal aorta (r=-0.26, P=0.008). This association was similar in magnitude but opposite to that of body surface area (largest known determinant of aortic diameter) and independent of known cardiovascular risk factors. This relationship is specific to AMH, as inhibin B, a Sertoli cell hormone-like AMH, did not correlate with aortic diameter (r=-0.04, P=0.66) despite partially correlating with AMH. Among men with known vascular disease, higher AMH levels were associated with varicose vein disease, while men with higher levels of AMH were under-represented in the abdominal aortic aneurysm relative to the healthy cohort. These findings identify AMH as a novel putative regulator of the cardiovascular system.

Elderly men have low levels of anti-Müllerian hormone and inhibin B, but with high interpersonal variation: a cross-sectional study of the sertoli cell hormones in 615 community-dwelling men

The Sertoli cells of the testes secrete anti-Müllerian hormone (Müllerian inhibiting Substance, AMH) and inhibin B (InhB). AMH triggers the degeneration of the uterine precursor in male embryos, whereas InhB is part of the gonadal-pituitary axis for the regulation of sperm production in adults. However, both hormones are also putative regulators of homeostasis, and age-related changes in these hormones may therefore be important to the health status of elderly men. The levels of AMH in elderly men are unknown, with limited information being available about age-related changes in InhB. We have therefore used ELISAs to measure Sertoli cell hormone levels in 3 cohorts of community-dwelling men in New Zealand. In total, 615 men were examined, 493 of which were aged 65 or older. Serum AMH and InhB levels inversely correlated with age in men older than 50 years (p<0.001) but not in the younger men. A minority of elderly men had undetectable levels of AMH and InhB. The variation in hormone levels between similarly aged men increased with the age of men. AMH and InhB partially correlated with each other as expected (r = 0.48, p<0.001). However, the ratio of the two Sertoli hormones varied significantly between men, with this variation increasing with age. Elderly men selected for the absence of cardiovascular disease had AMH levels similar to those of young men whereas their InhB levels did not differ from aged-matched controls. These data suggests that Sertoli cell number and function changes with age, but with the extent and nature of the changes varying between men.

Myocardial alternative RNA splicing and gene expression profiling in early stage hypoplastic left heart syndrome

Hypoplastic Left Heart Syndrome (HLHS) is a congenital defect characterized by underdevelopment of the left ventricle and pathological compensation of the right ventricle. If untreated, HLHS is invariably lethal due to the extensive increase in right ventricular workload and eventual failure. Despite the clinical significance, little is known about the molecular pathobiological state of HLHS. Splicing of mRNA transcripts is an important regulatory mechanism of gene expression. Tissue specific alterations of this process have been associated with several cardiac diseases, however, transcriptional signature profiles related to HLHS are unknown. In this study, we performed genome-wide exon array analysis to determine differentially expressed genes and alternatively spliced transcripts in the right ventricle (RV) of six neonates with HLHS, compared to the RV and left ventricle (LV) from non-diseased control subjects. In HLHS, over 180 genes were differentially expressed and 1800 were differentially spliced, leading to changes in a variety of biological processes involving cell metabolism, cytoskeleton, and cell adherence. Additional hierarchical clustering analysis revealed that differential gene expression and mRNA splicing patterns identified in HLHS are unique compared to non-diseased tissue. Our findings suggest that gene expression and mRNA splicing are broadly dysregulated in the RV myocardium of HLHS neonates. In addition, our analysis identified transcriptome profiles representative of molecular biomarkers of HLHS that could be used in the future for diagnostic and prognostic stratification to improve patient outcome.

Bone morphogenetic protein endothelial cell precursor-derived regulator regulates retinal angiogenesis in vivo in a mouse model of oxygen-induced retinopathy

OBJECTIVE

Bone morphogenetic proteins (BMPs) are potently proangiogenic; however, the mechanisms underlying the regulation of vessel development by BMPs are not fully understood. To assess the significance of BMP endothelial cell precursor-derived regulator (BMPER) in blood vessel formation in vivo, we investigated its role in retinal angiogenesis.

METHODS AND RESULTS

In a model of oxygen-induced retinopathy, Bmper mRNA expression and protein levels are downregulated, correlating with the initiation of Sma and Mad related protein phosphorylation in endothelial cells. Moreover, Bmper haploinsufficiency results in an increased rate of retinal revascularization, with retinas from Bmper+/- mice displaying increased numbers of branching points and angiogenic sprouts at the leading edge of the newly formed vasculature. Furthermore, although Bmper haploinsufficiency does not alter Bmp expression, it does lead to an increase in BMP signaling, as evidenced by increased phosphorylated Sma and Mad related protein levels in endothelial cells and increased expression of known BMP target genes.

CONCLUSIONS

These observations provide compelling evidence that BMPER is important in the regulation of BMP signaling and revascularization in the hypoxic retina. These bring forth the possibility of novel therapeutic approaches for pathological angiogenesis based on manipulation of BMP signaling.