Sex-dependent expression of galectin-1, a cardioprotective ß-galactoside-binding lectin, in human calcific aortic stenosis.

We aimed to analyze sex-related differences in galectin-1 (Gal-1), a ß-galactoside-binding lectin, in aortic stenosis (AS) and its association with the inflammatory and fibrocalcific progression of AS. Gal-1 was determined in serum and aortic valves (AVs) from control and AS donors by western blot and immunohistochemistry. Differences were validated by ELISA and qPCR in AS samples. In vitro experiments were conducted in primary cultured valve interstitial cells (VICs). Serum Gal-1 was not different neither between control and AS nor between men and women. There was no association between circulating and valvular Gal-1 levels. The expression of Gal-1 in stenotic AVs was higher in men than women, even after adjusting for confounding factors, and was associated with inflammation, oxidative stress, extracellular matrix remodeling, fibrosis, and osteogenesis. Gal-1 (LGALS1) mRNA was enhanced within fibrocalcific areas of stenotic AVs, especially in men. Secretion of Gal-1 was up-regulated over a time course of 2, 4, and 8 days in men's calcifying VICs, only peaking at day 4 in women's VICs. In vitro, Gal-1 was associated with similar mechanisms to those in our clinical cohort. ß-estradiol significantly up-regulated the activity of an LGALS1 promoter vector and the secretion of Gal-1, only in women's VICs. Supplementation with rGal-1 prevented the effects elicited by calcific challenge including the metabolic shift to glycolysis. In conclusion, Gal-1 is up-regulated in stenotic AVs and VICs from men in association with inflammation, oxidative stress, matrix remodeling, and osteogenesis. Estrogens can regulate Gal-1 expression with potential implications in post-menopause women. Exogenous rGal-1 can diminish calcific phenotypes in both women and men.

Influence of diabetes mellitus on the pathological profile of aortic stenosis: a sex-based approach.

BACKGROUND: Diabetes mellitus (DM) accelerates the progression of aortic stenosis (AS), but how their underlying molecular mechanisms interact is not clear. Moreover, whether DM contributes to clinically relevant sex-differences in AS is unknown. In this work we aim to characterize the sex-specific profile of major pathological mechanisms fundamental to aortic valve (AV) degeneration in AS patients with or without concomitant DM. METHODS: 283 patients with severe AS undergoing surgical valve replacement (27.6% DM, 59.4% men) were recruited. Expression of pathological markers related to AS were thoroughly assessed in AVs and valve interstitial cells (VICs) according to sex and presence of DM. Complementary in vitro experiments in VICs in the presence of high-glucose levels (25 mM) for 24, 48 and 72 h were performed. RESULTS: Oxidative stress and metabolic dysfunction markers were increased in AVs from diabetic AS patients compared to non-diabetic patients in both sexes. However, disbalanced oxidative stress and enhanced inflammation were more predominant in AVs from male AS diabetic patients. Osteogenic markers were exclusively increased in the AVs of diabetic women. Basal characterization of VICs confirmed that oxidative stress, inflammation, calcification, and metabolic alteration profiles were increased in diabetic VICs with sex-specific differences. VICs cultured in hyperglycemic-like conditions triggered inflammatory responses in men, whereas in women rapid and higher production of pro-osteogenic molecules. CONCLUSIONS: DM produces sex-specific pathological phenotypes in AV of AS patients. Importantly, women with diabetes are more prone to develop AV calcification. DM should be considered as a risk factor in AS especially in women.

Sex-specific role of galectin-3 in aortic stenosis.

BACKGROUND: Aortic stenosis (AS) is characterized by inflammation, fibrosis, osteogenesis and angiogenesis. Men and women develop these mechanisms differently. Galectin-3 (Gal-3) is a pro-inflammatory and pro-osteogenic lectin in AS. In this work, we aim to analyse a potential sex-differential role of Gal-3 in AS. METHODS: 226 patients (61.50% men) with severe AS undergoing surgical aortic valve (AV) replacement were recruited. In AVs, Gal-3 expression and its relationship with inflammatory, osteogenic and angiogenic markers was assessed. Valve interstitial cells (VICs) were primary cultured to perform in vitro experiments. RESULTS: Proteomic analysis revealed that intracellular Gal-3 was over-expressed in VICs of male AS patients. Gal-3 secretion was also higher in men's VICs as compared to women's. In human AVs, Gal-3 protein levels were significantly higher in men, with stronger immunostaining in VICs with myofibroblastic phenotype and valve endothelial cells. Gal-3 levels in AVs were positively correlated with inflammatory markers in both sexes. Gal-3 expression was also positively correlated with osteogenic markers mainly in men AVs, and with angiogenic molecules only in this sex. In vitro, Gal-3 treatment induced expression of inflammatory, osteogenic and angiogenic markers in male's VICs, while it only upregulated inflammatory and osteogenic molecules in women-derived cells. Gal-3 blockade with pharmacological inhibitors (modified citrus pectin and G3P-01) prevented the upregulation of inflammatory, osteogenic and angiogenic molecules. CONCLUSIONS: Gal-3 plays a sex-differential role in the setting of AS, and it could be a new sex-specific therapeutic target controlling pathological features of AS in VICs.

Aortic stenosis (AS) is a condition that affects the aortic valves (AVs) of the heart and leads to death if untreated. Males and females show clear differences in the onset of AS, both clinically and in valve deterioration. In this study we identified galectin-3 (Gal-3) as a molecule involved in the development of AS alterations with different effects in men and women. We analyzed AVs of 226 patients (139 male and 87 female) with severe AS who underwent surgical AV replacement to study the association of Gal-3 with markers of mechanisms related to AS, such as inflammation, calcification and blood vessels formation. We performed experiments in valvular interstitial cells (VICs) to evaluate the impact of Gal-3 in these cells and its potential use as a therapeutic target. Our results showed that Gal-3 was more expressed in AVs and VICs of men over women. In AVs, Gal-3 levels were associated with inflammatory markers either in male and female, while they correlated with osteogenic markers mainly in men and with angiogenic only in male. The treatment of VICs with Gal-3 produced increased levels of inflammatory and osteogenic molecules by cells of both sexes, but of angiogenic markers only in male's. Pharmacological inhibition of Gal-3 prevented the increase of these pathological markers in VICs. Overall, our study indicates that Gal-3 is a molecule implicated in the setting of AS in a sex-differential way and its targeting may lead to a new sex-specific therapeutic option for AS treatment.

Los niveles de ST2 soluble están relacionados con la fibrosis miocárdica de sustitución en la estenosis aórtica grave / Soluble ST2 levels are related to replacement myocardial fibrosis in severe aortic stenosis

Introducción y objetivos: Los pacientes con estenosis aórtica presentan remodelado del ventrículo izquierdo (VI) y fibrosis miocárdica de sustitución (FMS). Se desconoce si sST2 se asocia con la FMS medida por resonancia magnética y con el sexo. Métodos: Se incluyó a 79 pacientes consecutivos (73,0 [68,0-78,0] años; 61% varones) con estenosis aórtica grave aislada tratados con sustitución valvular. Se identificaron y cuantificaron la FMS mediante realce tardío post-gadolinio (RTG) y se valoró el sST2 sérico. Resultados: La FMS se asoció con sST2 elevado, hipertrofia y dilatación del VI y menor fracción de eyección del VI. Todos los pacientes con disfunción del VI tenían FMS. sST2 ≥ 28,2 ng/ml se asoció con FMS y mayor hipertrofia del VI. La masa de RTG se correlacionó con el remodelado del VI y sST2. Los niveles de sST2 fueron mayores en pacientes con fibrosis intramiocárdica frente a subendocárdica. El análisis multivariante evidenció que solo la fracción de eyección y sST2 se asociaban con la FMS. Los varones presentaron mayores niveles de FMS y sST2. En varones la FMS correlacionó con mayor dilatación e hipertrofia ventricular, y con la masa de RTG. Conclusiones: El sST2 es un factor independiente de FMS en la estenosisi aórtica grave aislada. sST2 ≥ 28,2 ng/ml predice la FMS y se relaciona con mayor hipertrofia del VI. La expresión de sST2 y asociaciones clínicas deben ser sexo-específicas.(AU)

Introduction and objectives: Patients with aortic stenosis (AS) exhibit left ventricular (LV) remodeling and replacement myocardial fibrosis (RMF). Whether sST2 is associated with RMF measured by cardiac magnetic resonance and with sex remains unknown. Methods: We recruited 79 consecutive patients (73.0 [68.0-78.0] years; 61% men) with severe isolated AS underdoing valve replacement. RMF was identified and quantified by late gadolinium enhancement (LGE). Serum sST2 levels were determined. Results: RMF was associated with higher circulating sST2 levels, LV hypertrophy and dilation, and lower LV ejection fraction. All patients with LV dysfunction had RMF. Circulating levels of sST2 ≥ 28.8 ng/mL were associated with RMF and greater LV hypertrophy. LGE mass was correlated with LV remodeling and sST2. Of note, sST2 levels were also associated with the RMF pattern, being higher in midwall than in subendocardial fibrosis. Multivariate analyses showed that only LV ejection fraction and sST2 levels were associated with RMF. Moreover, men had higher levels of sST2 and RMF. RMF was associated with higher LV dilation and hypertrophy only in men and was correlated with LGE mass. Conclusions: SST2 was an independent factor for RMF in patients with severe isolated AS. The presence of RMF was predicted by sST2 ≥ 28.2 ng/mL, and was associated with greater LV hypertrophy. sST2 expression and clinical associations may be sex-specific.(AU)

Soluble ST2 levels are related to replacement myocardial fibrosis in severe aortic stenosis.

INTRODUCTION AND OBJECTIVES: Patients with aortic stenosis (AS) exhibit left ventricular (LV) remodeling and replacement myocardial fibrosis (RMF). Whether sST2 is associated with RMF measured by cardiac magnetic resonance and with sex remains unknown. METHODS: We recruited 79 consecutive patients (73.0 [68.0-78.0] years; 61% men) with severe isolated AS underdoing valve replacement. RMF was identified and quantified by late gadolinium enhancement (LGE). Serum sST2 levels were determined. RESULTS: RMF was associated with higher circulating sST2 levels, LV hypertrophy and dilation, and lower LV ejection fraction. All patients with LV dysfunction had RMF. Circulating levels of sST2 ≥ 28.8 ng/mL were associated with RMF and greater LV hypertrophy. LGE mass was correlated with LV remodeling and sST2. Of note, sST2 levels were also associated with the RMF pattern, being higher in midwall than in subendocardial fibrosis. Multivariate analyses showed that only LV ejection fraction and sST2 levels were associated with RMF. Moreover, men had higher levels of sST2 and RMF. RMF was associated with higher LV dilation and hypertrophy only in men and was correlated with LGE mass. CONCLUSIONS: SST2 was an independent factor for RMF in patients with severe isolated AS. The presence of RMF was predicted by sST2 ≥ 28.2 ng/mL, and was associated with greater LV hypertrophy. sST2 expression and clinical associations may be sex-specific.

Sex-dependent expression of neutrophil gelatinase-associated lipocalin in aortic stenosis.

BACKGROUND: Accumulating evidence suggest the existence of sex-related differences in the pathogenesis of aortic stenosis (AS) with inflammation, oxidative stress, fibrosis and calcification being over-represented in men. Neutrophil gelatinase-associated lipocalin (NGAL) is expressed in a myriad of tissues and cell types, and it is associated with acute and chronic pathological processes comprising inflammation, fibrosis or calcification. Sex-dependent signatures have been evidenced for NGAL which expression has been associated predominantly in males to metabolic and cardiovascular disorders. We aimed to analyse sex-related differences of NGAL in AS and its role in the inflammatory and fibrocalcific progression of AS. METHODS AND RESULTS: 220 (60.45% men) patients with severe AS elective for surgical aortic valve (AV) replacement were recruited. Immunohistochemistry revealed higher expression of NGAL in calcific areas of AVs and that was validated by qPCR in in 65 (60% men) donors. Valve interstitial cells (VICs) were a source of NGAL in these samples. Proteome profiler analyses evidenced higher expression of NGAL in men compared to women, and that was further validated by ELISA. NGAL expression in the AV was correlated with inflammation, oxidative stress, and osteogenic markers, as well as calcium score. The expression of NGAL, both intracellular and secreted (sNGAL), was significantly deregulated only in calcifying male-derived VICs. Depletion of intracellular NGAL in calcifying male-derived VICs was associated with pro-inflammatory profiles, dysbalanced matrix remodelling and pro-osteogenic profiles. Conversely, exogenous NGAL mediated inflammatory and dysbalanced matrix remodelling in calcifying VICs, and all that was prevented by the pharmacological blockade of NGAL. CONCLUSIONS: Owing to the over-expression of NGAL, the AV from men may be endowed with higher expression of inflammatory, oxidative stress, matrix remodelling and osteogenic markers supporting the progression of calcific AS phenotypes. The expression of NGAL in the VIC emerges as a potential therapeutic checkpoint, with its effects being potentially reverted by the pharmacological blockade of extracellular NGAL.

Characterization of the sex-specific pattern of angiogenesis and lymphangiogenesis in aortic stenosis.

Objective: We aim to analyze sex-related differences in angiogenesis and lymphangiogenesis in aortic valves (AVs) and valve interstitial cells (VICs) from aortic stenosis (AS) patients. Approach and Results: Totally 230 patients (59% men) with severe AS undergoing surgical valve replacement were recruited. The density of total neovessels was higher in AVs from men as compared to women. Both small and medium neovessels were more abundant in men's AVs. Accordingly, male AVs exhibited higher CD31 and VE-cadherin expressions. The levels of the pro-angiogenic markers, such as vascular endothelial growth factor (VEGF)-A, VEGF receptor (VEGFR)1, VEGFR2, insulin-like growth factor-binding protein-2 (IGFBP-2), interleukin (IL)-8, chemerin, and fibroblast growth factor (FGF)-7, were increased in AVs from men. Transforming growth factor-ß expression was higher in male AVs. The expression of antiangiogenic molecules thrombospondin (Tsp)-1, endostatin, and CD36 was upregulated in male AVs, although the levels of Tsp-2, IL-4, IL-12p70, and chondromodulin-1 were similar between both sexes. The number of lymphatic vessels and the expression of the lymphangiogenic markers Lyve-1 and D2-40 was higher in men's AV as well as VEGF-C, VEGF-D, and VEGFR3. Multivariate analyses adjusted for confounders further validated the sex-dependent expression of these targets. VICs isolated from men's AVs secreted higher amounts of the pro-angiogenic factors, VEGF-A, VEGFR1, IGFBP-2, and FGF-7, as well as the pro-lymphangiogenic factors, VEGF-C, VEGF-D, and VEGFR3, than women without changes in antiangiogenic markers. Conclusion: Our data show that aberrant angiogenic and lymphangiogenic cues are over-represented in male AVs. Importantly, the VIC is a relevant source of multiple morphogens involved in angiogenesis and lymphangiogenesis likely endowing the AV of men with the predominant calcific AS phenotypes.

Targeting Fatty Acid-Binding Protein 4 Improves Pathologic Features of Aortic Stenosis.

Aortic stenosis (AS) is a fibrocalcific disease of the aortic valves (AVs). Sex-differences in AS pathophysiology have recently been described. High levels of fatty acid-binding protein 4 (FAPB4) in atherosclerotic plaques have been associated with increased local inflammation, endothelial dysfunction, and plaque vulnerability. FABP4 pharmacological blockade has been shown to be effective for the treatment of atherosclerosis by modulating metabolic and inflammatory pathways. We aimed to analyze the sex-specific expression of FABP4 in AS and its potential role as a therapeutic target. A total of 226 patients (61.5% men) with severe AS undergoing surgical AV replacement were recruited. The FABP4 levels were increased in the AVs of AS patients compared to the control subjects, showing greater expression in the fibrocalcific regions. Male AVs exhibited higher levels of FABP4 compared to females, correlating with markers of inflammation (IL-6, Rantes), apoptosis (Bax, caspase-3, Bcl-2), and calcification (IL-8, BMP-2 and BMP-4). VICs derived from AS patients showed the basal expression of FABP4 in vitro. Osteogenic media induced upregulation of intracellular and secreted FABP4 levels in male VICs after 7 days, along with increased levels of inflammatory, pro-apoptotic, and osteogenic markers. Treatment with BMS309403, a specific inhibitor of FABP4, prevented from all of these changes. Thus, we propose FABP4 as a new sex-specific pharmacological therapeutic target in AS.

Sex-Related Signaling of Aldosterone/Mineralocorticoid Receptor Pathway in Calcific Aortic Stenosis.

BACKGROUND: There are sex differences in the pathophysiology of aortic valve (AV) calcification in patients with aortic stenosis, although the molecular and cellular mechanisms have not been elucidated. Aldosterone (Aldo) promotes proteoglycan synthesis in valve interstitial cells (VICs) from mitral valves via the mineralocorticoid receptor (MR). We investigated the influence of sex in the role of Aldo/MR pathway in AV alterations in patients with aortic stenosis. METHODS AND RESULTS: MR was expressed by primary aortic VICs and in AVs from patients with aortic stenosis. MR expression positively correlated with VIC activation markers in AVs from both sexes. However, MR expression was positively associated with molecules involved in AV calcification only in AV from men. Aldo enhanced VIC activation markers in cells from men and women. Interestingly, Aldo increased the expression of calcification markers only in VICs isolated from men. In female VICs, Aldo enhanced fibrotic molecules. MR antagonism (spironolactone) blocked all the above effects. Cytokine arrays showed ICAM (intercellular adhesion molecule)-1 and osteopontin to be specifically increased by Aldo in male VICs. In AVs from men, MR expression positively associated with both ICAM-1 (intercellular adhesion molecule-1) and osteopontin. Only in female VICs, estradiol treatment blocked Aldo-induced VICs activation, inflammation, and fibrosis. CONCLUSIONS: These findings demonstrate that the Aldo/MR pathway could play a role in early stages of aortic stenosis by promoting VICs activation, fibrosis, and ulterior calcification. Importantly, Aldo/MR pathway is involved in fibrosis in women and in early AV calcification only in men. Accordingly, MR antagonism emerges as a new sex-specific pharmacological treatment to prevent AV alterations.

Sex-Differences in Aortic Stenosis: Mechanistic Insights and Clinical Implications.

Objective: We aim to analyse sex-specific differences in aortic valves (AVs) and valve interstitial cells (VICs) from aortic stenosis (AS) patients. Approach and Results: 238 patients with severe AS undergoing surgical valve replacement were recruited. Two hundred and two AVs (39.1% women) were used for ex vivo analyses and 36 AVs (33.3% women) for in vitro experiments. AVs from men presented increased levels of the inflammatory molecules interleukin (IL)-1ß, IL-6, Rantes, and CD45. Oxidative stress (eNOS, myeloperoxidase, malondialdehyde and nitrotyrosine) was upregulated in male AVs. Concerning fibrosis, similar levels of collagen type I, decreased levels of collagen type III and enhanced fibronectin, active Lox-1 and syndecan-1 expressions were found in AVs from men compared with women. Extracellular matrix (ECM) remodeling was characterized by reduced metalloproteinase-1 and 9 expression and increased tissue inhibitor of metalloproteinase-2 expression in male AVs. Importantly, osteogenic markers (bone morphogenetic protein-9, Rank-L, osteopontin, periostin, osteocalcin and Sox-9) and apoptosis (Bax, Caspase 3, p53, and PARP1) were enhanced in AVs from men as compared to women. Isolated male VICs presented higher myofibroblast-like phenotype than female VICs. Male VICs exhibited increased inflammatory, oxidative stress, fibrotic, apoptosis and osteogenic differentiation markers. Conclusions: Our results suggest that the mechanisms driving the pathogenesis of AS could be different in men and women. Male AVs and isolated VICs presented more inflammation, oxidative stress, ECM remodeling and calcification as compared to those from women. A better knowledge of the pathophysiological pathways in AVs and VICs will allow the development of sex-specific options for the treatment of AS.

Beneficial Effects of Mineralocorticoid Receptor Pathway Blockade against Endothelial Inflammation Induced by SARS-CoV-2 Spike Protein.

BACKGROUND: Vascular endothelial cells activation and dysfunction mediate inflammation and abnormal coagulation in COVID-19 patients. Mineralocorticoid receptor (MR) signaling and its downstream target Galectin-3 (Gal-3) are known to mediate cardiovascular inflammation and might be involved in the pathogenesis of COVID-19 complications. Accordingly, we aimed to investigate the potential beneficial effects of MR antagonism and Gal-3 inhibition on the inflammatory response induced by SARS-CoV-2 Spike protein in human aortic endothelial cells (HAECs). METHODS: HAECs were treated with recombinant SARS-COV2 Spike (S) protein. MR antagonists (namely spironolactone and eplerenone) or the Gal-3 inhibitor G3P-01 were supplemented before and after S protein challenge. HAECs supernatants were assessed by ELISA or Western blotting. RESULTS: HAECs treated with recombinant S protein resulted in enhanced secretion of inflammatory molecules (interleukin-6, monocyte chemoattractant protein-1, interleukin-18, interleukin-27, and interferon-γ) as well as in the thrombosis marker plasminogen activator inhibitor (PAI)-1. This was prevented and reversed by both MR antagonists and G3P-01. CONCLUSIONS: These findings indicate that MR/Gal-3 pathway blockade could be a promising option to reduce endothelial inflammation in SARS-CoV-2 infection.

Activation of the Interleukin-33/ST2 Pathway Exerts Deleterious Effects in Myxomatous Mitral Valve Disease.

Mitral valve disease (MVD) is a frequent cause of heart failure and death worldwide, but its etiopathogenesis is not fully understood. Interleukin (IL)-33 regulates inflammation and thrombosis in the vascular endothelium and may play a role in the atherosclerotic process, but its role in mitral valve has not been investigated. We aim to explore IL-33 as a possible inductor of myxomatous degeneration in human mitral valves. We enrolled 103 patients suffering from severe mitral regurgitation due to myxomatous degeneration undergoing mitral valve replacement. Immunohistochemistry of the resected leaflets showed IL-33 and ST2 expression in both valve interstitial cells (VICs) and valve endothelial cells (VECs). Positive correlations were found between the levels of IL-33 and molecules implicated in the development of myxomatous MVD, such as proteoglycans, extracellular matrix remodeling enzymes (matrix metalloproteinases and their tissue inhibitors), inflammatory and fibrotic markers. Stimulation of single cell cultures of VICs and VECs with recombinant human IL-33 induced the expression of activated VIC markers, endothelial-mesenchymal transition of VECs, proteoglycan synthesis, inflammatory molecules and extracellular matrix turnover. Our findings suggest that the IL-33/ST2 system may be involved in the development of myxomatous MVD by enhancing extracellular matrix remodeling.

Beneficial Effects of Mineralocorticoid Receptor Antagonism on Myocardial Fibrosis in an Experimental Model of the Myxomatous Degeneration of the Mitral Valve.

Mitral valve prolapse (MVP) patients develop myocardial fibrosis that is not solely explained by volume overload, but the pathophysiology has not been defined. Mineralocorticoid receptor antagonists (MRAs) improve cardiac function by decreasing cardiac fibrosis in other heart diseases. We examined the role of MRA in myocardial fibrosis associated with myxomatous degeneration of the mitral valve. Myocardial fibrosis has been analyzed in a mouse model of mitral valve myxomatous degeneration generated by pharmacological treatment with Nordexfenfluramine (NDF) in the presence of the MRA spironolactone. In vitro, adult human cardiac fibroblasts were treated with NDF and spironolactone. In an experimental mouse, MRA treatment reduced interstitial/perivascular fibrosis and collagen type I deposition. MRA administration blunted NDF-induced cardiac expression of vimentin and the profibrotic molecules galectin-3/cardiotrophin-1. In parallel, MRA blocked the increase in cardiac non-fibrillar proteins such as fibronectin, aggrecan, decorin, lumican and syndecan-4. The following effects are blocked by MRA: in vitro, in adult human cardiac fibroblasts, NDF-treatment-induced myofibroblast activation, collagen type I and proteoglycans secretion. Our findings demonstrate, for the first time, the contribution of the mineralocorticoid receptor (MR) to the development of myocardial fibrosis associated with mitral valve myxomatous degeneration. MRA could be a therapeutic approach to reduce myocardial fibrosis associated with MVP.