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Abstract Background KLK15 over-expression is reported to be a significant predictor of reduced progression-free survival and overall survival in ovarian cancer. Our aim was to analyse the KLK15 gene for putative functional single nucleotide polymorphisms (SNPs) and assess the association of these and KLK15 HapMap tag SNPs with ovarian cancer survival. Results In silico analysis was performed to identify KLK15 regulatory elements and to classify potentially functional SNPs in these regions. After SNP validation and identification by DNA sequencing of ovarian cancer cell lines and aggressive ovarian cancer patients, 9 SNPs were shortlisted and genotyped using the Sequenom iPLEX Mass Array platform in a cohort of Australian ovarian cancer patients (N = 319). In the Australian dataset we observed significantly worse survival for the KLK15 rs266851 SNP in a dominant model (Hazard Ratio (HR) 1.42, 95% CI 1.02-1.96). This association was observed in the same direction in two independent datasets, with a combined HR for the three studies of 1.16 (1.00-1.34). This SNP lies 15bp downstream of a novel exon and is predicted to be involved in mRNA splicing. The mutant allele is also predicted to abrogate an HSF-2 binding site. Conclusions We provide evidence of association for the SNP rs266851 with ovarian cancer survival. Our results provide the impetus for downstream functional assays and additional independent validation studies to assess the role of KLK15 regulatory SNPs and KLK15 isoforms with alternative intracellular functional roles in ovarian cancer survival.

Clinical conditions, including chronic obstructive pulmonary disease or pulmonary arterial hypertension (PAH), can lead to chronic right ventricle pressure overload and progressive right heart failure (RHF). RHF can be identified by right-sided cardiac hypertrophy and dilation associated with abnormal myocardial function affecting the RV and the right atrium (RA). We recently demonstrated that severe RHF is accompanied by an increased risk of atrial inflammation, atrial fibrosis, and atrial fibrillation (AF), the most common type of cardiac arrhythmia (CA). Recent studies have shown that RV and RA inflammation plays an important role in the arrhythmogenesis of CA, including AF. However, the impact of inflammation in the development of CA and AF in RHF is poorly described. Experimental models of RHF are required to better understand the association between right-sided myocardial inflammation and CA. The rat model of monocrotaline (MCT)-induced pulmonary hypertension (PH) is well-established to provoke RHF. However, MCT triggers severe pneumo-toxicity and pulmonary inflammation. Hence, MCT-induced RHF does not help to distinguish whether the subsequent myocardial inflammation originates from the RHF per se or circulating inflammatory signals secreted by the injured lung. In this article, a mechanical method involving pulmonary artery trunk banding (PAB) was used to provoke right-sided cardiac arrhythmogenesis. The PAB consists of performing a permanent suture of the pulmonary artery trunk for 3 weeks. Such an approach generates increased right-sided pressure overload. At D21 post-PAB, the suture results in hypertrophied, dilated, and inflamed RV and RA. The PAB-induced RHF is also accompanied by vulnerability to ventricular and atrial arrhythmias, including AF.

Lean patients with NAFLD may develop cardiac complications independently of pre-existent metabolic disruptions and comorbidities. To address the underlying mechanisms independent of the development of obesity, we used a murine model of hepatic mitochondrial deficiency. The liver-heart axis was studied as these mice develop microvesicular steatosis without obesity. Our results unveil a sex-dependent phenotypic remodeling beyond liver damage. Males, more than females, show fasting hypoglycemia and increased insulin sensitivity. They exhibit diastolic dysfunction, remodeling of the circulating lipoproteins and cardiac lipidome. Conversely, females do not manifest cardiac dysfunction but exhibit cardiometabolic impairments supported by impaired mitochondrial integrity and β-oxidation, remodeling of circulating lipoproteins and intracardiac accumulation of deleterious triglycerides. This study underscores metabolic defects in the liver resulting in significant sex-dependent cardiac abnormalities independent of obesity. This experimental model may prove useful to better understand the sex-related variability, notably in the heart, involved in the progression of lean-NAFLD., (© 2024. The Author(s).)

Background: Angiopoietin-like 2 (ANGPTL2) is a pro-inflammatory and pro-oxidant circulating protein that predicts and promotes chronic inflammatory diseases such as atherosclerosis in humans. Transgenic murine models demonstrated the deleterious role of ANGPTL2 in vascular diseases, while deletion of ANGPTL2 was protective. The nature of its role in cardiac tissues is, however, less clear. Indeed, in adult mice knocked down (KD) for ANGPTL2, we recently reported a mild left ventricular (LV) dysfunction originating from a congenital aortic valve stenosis, demonstrating that ANGPTL2 is essential to cardiac development and function. Hypothesis: Because we originally demonstrated that the KD of ANGPTL2 protected vascular endothelial function via an upregulation of arterial NOX4, promoting the beneficial production of dilatory H 2 O 2 , we tested the hypothesis that increased cardiac NOX4 could negatively affect cardiac redox and remodeling and contribute to LV dysfunction observed in adult Angptl2 -KD mice. Methods and results: Cardiac expression and activity of NOX4 were higher in KD mice, promoting higher levels of cardiac H 2 O 2 when compared to wild-type (WT) mice. Immunofluorescence showed that ANGPTL2 and NOX4 were co-expressed in cardiac cells from WT mice and both proteins co-immunoprecipitated in HEK293 cells, suggesting that ANGPTL2 and NOX4 physically interact. Pressure overload induced by transverse aortic constriction surgery (TAC) promoted LV systolic dysfunction in WT mice but did not further exacerbate the dysfunction in KD mice. Importantly, the severity of LV systolic dysfunction in KD mice (TAC and control SHAM) correlated with cardiac Nox4 expression. Injection of an adeno-associated virus (AAV9) delivering shRNA targeting cardiac Nox4 expression fully reversed LV systolic dysfunction in KD-SHAM mice, demonstrating the causal role of NOX4 in cardiac dysfunction in KD mice. Targeting cardiac Nox4 expression in KD mice also induced an antioxidant response characterized by increased expression of NRF2/KEAP1 and catalase. Conclusion: Together, these data reveal that the absence of ANGPTL2 induces an upregulation of cardiac NOX4 that contributes to oxidative stress and LV dysfunction. By interacting and repressing cardiac NOX4, ANGPTL2 could play a new beneficial role in the maintenance of cardiac redox homeostasis and function., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Labbé, Martel, Shi, Montezano, He, Gillis, Higgins, Villeneuve, Touyz, Tardif, Thorin-Trescases and Thorin.)

Aims: The adenylate cyclase type 9 (ADCY9) gene appears to determine atherosclerotic outcomes in patients treated with dalcetrapib. In mice, we recently demonstrated that Adcy9 inactivation potentiates endothelial function and inhibits atherogenesis. The objective of this study was to characterize the contribution of ADCY9 to the regulation of endothelial signalling pathways involved in atherosclerosis., Methods and Results: We show that ADCY9 is expressed in the endothelium of mouse aorta and femoral arteries. We demonstrate that ADCY9 inactivation in cultured endothelial cells paradoxically increases cAMP accumulation in response to the adenylate cyclase activators forskolin and vasoactive intestinal peptide (VIP). Reciprocally, ADCY9 overexpression decreases cAMP production. Using mouse femoral artery arteriography, we show that Adcy9 inactivation potentiates VIP-induced endothelial-dependent vasodilation. Moreover, Adcy9 inactivation reduces mouse atheroma endothelial permeability in different vascular beds. ADCY9 overexpression reduces forskolin-induced phosphorylation of Ser157-vasodilator-stimulated phosphoprotein (VASP) and worsens thrombin-induced fall of RAP1 activity, both leading to increased endothelial permeability. ADCY9 inactivation in thrombin-stimulated human coronary artery endothelial cells results in cAMP accumulation, increases p-Ser157-VASP, and inhibits endothelial permeability. MLC2 phosphorylation and actin stress fibre increases in response to thrombin were reduced by ADCY9 inactivation, suggesting actin cytoskeleton regulation. Finally, using the Miles assay, we demonstrate that Adcy9 regulates thrombin-induced endothelial permeability in vivo in normal and atherosclerotic animals., Conclusion: Adcy9 is expressed in endothelial cells and regulates local cAMP and endothelial functions including permeability relevant to atherogenesis., Competing Interests: Conflict of interest: J.-C.T. reports receiving grant support from Amarin, Ceapro, Esperion, Ionis, Novartis, and RegenXBio, receiving grant support and honoraria from AstraZeneca, Pfizer, and Servier, receiving honoraria from HLS Pharmaceuticals and Pendopharm, receiving grant support, honoraria, and minor equity interest from DalCor Pharmaceuticals, holding a pending patent (US20170233812A1) on genetic markers for predicting responsiveness to therapy with a HDL-raising or HDL mimicking agent, and holding pending patents (62/935 751 and 62/935 865) on methods for using low-dose colchicine after myocardial infarction, licensed to Montreal Heart Institute, for which royalties are received. J.-C.T. has waived his rights in and will not gain financially from the colchicine patents., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Pharmacogenomic studies have shown that ADCY9 genotype determines the effects of the CETP (cholesteryl ester transfer protein) inhibitor dalcetrapib on cardiovascular events and atherosclerosis imaging. The underlying mechanisms responsible for the interactions between ADCY9 and CETP activity have not yet been determined., Methods: Adcy9-inactivated ( Adcy9 Gt/Gt ) and wild-type (WT) mice, that were or not transgenic for the CETP gene (CETPtg Adcy9 Gt/Gt and CETPtg Adcy9 WT ), were submitted to an atherogenic protocol (injection of an AAV8 [adeno-associated virus serotype 8] expressing a PCSK9 [proprotein convertase subtilisin/kexin type 9] gain-of-function variant and 0.75% cholesterol diet for 16 weeks). Atherosclerosis, vasorelaxation, telemetry, and adipose tissue magnetic resonance imaging were evaluated., Results: Adcy9 Gt/Gt mice had a 65% reduction in aortic atherosclerosis compared to WT ( P<0.01). CD68 (cluster of differentiation 68)-positive macrophage accumulation and proliferation in plaques were reduced in Adcy9 Gt/Gt mice compared to WT animals ( P<0.05 for both). Femoral artery endothelial-dependent vasorelaxation was improved in Adcy9 Gt/Gt mice (versus WT, P<0.01). Selective pharmacological blockade showed that the nitric oxide, cyclooxygenase, and endothelial-dependent hyperpolarization pathways were all responsible for the improvement of vasodilatation in Adcy9 Gt/Gt ( P<0.01 for all). Aortic endothelium from Adcy9 Gt/Gt mice allowed significantly less adhesion of splenocytes compared to WT ( P<0.05). Adcy9 Gt/Gt mice gained more weight than WT with the atherogenic diet; this was associated with an increase in whole body adipose tissue volume ( P<0.01 for both). Feed efficiency was increased in Adcy9 Gt/Gt compared to WT mice ( P<0.01), which was accompanied by prolonged cardiac RR interval ( P<0.05) and improved nocturnal heart rate variability ( P=0.0572). Adcy9 inactivation-induced effects on atherosclerosis, endothelial function, weight gain, adipose tissue volume, and feed efficiency were lost in CETPtg Adcy9 Gt/Gt mice ( P>0.05 versus CETPtg Adcy9 WT )., Conclusions: Adcy9 inactivation protects against atherosclerosis, but only in the absence of CETP activity. This atheroprotection may be explained by decreased macrophage accumulation and proliferation in the arterial wall, and improved endothelial function and autonomic tone.