LDL lowering effect of PCSK9 inhibition is reduced in women

AIMS

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key regulator of plasma low-density lipoprotein cholesterol (LDL-C) concentration and its inhibition reduces the risk of atherosclerotic cardiovascular disease (ASCVD). We aimed to assess the sex-differential effect of either pharmacological or genetic inhibition of PCSK9 on LDL-C levels.

METHODS AND RESULTS

We meta-analyzed six real-life studies (1'216 men and 641 women) that investigated the effects of PCSK9 monoclonal antibodies (mAbs) on LDL-C reduction in men and women. Despite higher LDL-C levels in women at baseline (mean difference, MD = 17.4 mg/dL, p < 0.0001, women = 175 mg/dL vs. men = 152 mg/dL), the LDL-C reduction under PCSK9 mAbs treatment was significantly greater in men (MD = 7.6 mg/dL, 95% CI: 2.7-12.4, p = 0.002) than in women.We tested the sex-related association of the loss-of-function variant PCSK9-R46L with LDL-C plasma levels in 382'813 individuals (219'301 women and 163'512 men) free of lipid-lowering drugs from the UK biobank (UKBB) general population cohort. The magnitude of LDL-C reduction was larger in men than in women (mean LDL-C difference: -35 mg/dL vs. -26 mg/dL, when comparing homozygous carriers with non-carriers in men and women, respectively). The relationship between PCSK9-R46L and LDL-C was significantly dependent on sex (p-for-interaction = 7.2e-04).

CONCLUSION

These results demonstrate by complementary approaches that the decrease in LDL-C mediated by PCSK9 inhibition is slightly, but significantly, less marked in women than in men. These data reinforce the need for specific studies to develop sex-specific recommendations for the management of ASCVD in women.

Heritability and environmental influences on the onset of aortic valve sclerosis: a twin population study

Background

Aortic valve sclerosis (AVSc) is the earliest manifestation of a life-threatening cardiovascular disorder, namely aortic valve stenosis (AS). AVSc is also recognized as a red flag linked to worse cardiovascular outcomes in high-risk coronary artery disease patients. However, the genetic background of AVSc is still unknown.

Purpose

To examine whether the heritability and environmental contributions play a role in the onset of AVSc using a sample of Italian twins.

Methods

The present study is based on the classical twin design. Twins, aged 50 to 70 years, already enrolled in the Italian Twin Register, were contacted and invited to undergo a clinical, echocardiographic, and complete carotid artery ultrasound examination at the our Center, between July 2017 and December 2021. The presence of AVSc was recognized as non-uniform thickening with or without spotty calcified areas of the aortic valve leaflets without a significant transvalvular gradient (maximum aortic velocity &lt;2.5 m/s). Twin zygosity was assessed through a questionnaire on physical similarity during childhood, known to be ∼95% accurate. Tetrachoric twin correlations by zygosity were estimated with Mx Software using liability threshold saturated models and incorporating age as a covariate. Liability-threshold structural equation modelling was performed to decompose the phenotypic variance into contributions due to additive genetic (A), common environmental (C), and unique environmental (E) effects.

Results

A total of 216 adult twins (66 monozygotic, MZ and 42 dizygotic pairs, DZ; mean age 59.9±6.2) were enrolled in the study. The estimated prevalence rate of AVSc in the total sample was 29.2%. As significant sex differences were detected (males 45.2% and females 22.7%, p&lt;0.01), the additional twin analyses were performed as intra-sex analyses. Females showed a greater tetrachoric correlation in MZ twins (r=0.37) compared to DZ twins (r=0.23), suggesting the existence of a genetic influence. Genetic factors, under the best (AE) model, accounted for 38% of the variance in liability to AVSc with the remaining contribution due to unique environmental influences (E = 62%). The contribution of the common environment (C) to the goodness of fit was negligible. The male group was too small for statistical calculation.

Conclusion

To our knowledge, the present study is the first to document the involvement of genetic factors in the development of AVSc. Our data also warrant further studies to both validate the findings obtained and to better explore the heritability of AVSc. Furthermore, our results provide a first evidence that an echocardiographic screening in individuals with relatives affected by AVSc has a scientific rational basis.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Italian Ministry of Health

Impact of chronic GLP-1 receptor agonist and SGLT-2 inhibitor therapy on in-hospital outcomes of patients with diabetes mellitus hospitalized with acute myocardial infarction

Background

Glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium glucose cotransporter-2 inhibitors (SGLT-2i) demonstrated cardiovascular and renal protection in addition to their glucose-lowering effect. Whether their benefits occur also in patients with diabetes mellitus (DM) during hospitalisation with acute myocardial infarction (AMI) has not been investigated yet.

Purpose

We evaluated in-hospital outcomes of patients hospitalised with AMI according to their chronic use (before hospitalisation) of GLP-1 RA and SGLT-2i therapy.

Methods

Using administrative healthcare databases, we analysed patients hospitalised with a primary diagnosis of AMI from 2010 to 2019 in the Lombardy region, Italy. Patients were stratified according to their DM status, then divided into three cohorts: Group 1 (non-DM patients); Group 2 (DM patients taking GLP-1 RA or SGLT-2i); and Group 3 (DM patients not taking GLP-1 RA and/or SGLT-2i). Patients were matched in a 1:1:1 ratio using a propensity score including all available variables. The primary endpoint of the study was the composite of in-hospital mortality, acute heart failure, and acute kidney injury requiring renal replacement therapy.

Results

We identified 146,800 patients hospitalised with AMI (26% of them with DM). After propensity score matching, 1,030 patients were included in each group. The primary endpoint rate in the overall population was 16% (n=502) and it significantly increased going from Group 1 to Group 3 (13%, 16%, and 20% respectively; p for trend &lt;0.0001). The risk of the composite endpoint significantly increased from Group 1 to Group 3 (P for trend &lt;0.0001). In comparison with Group 2, Group 3 had a significant higher risk of the composite endpoint (OR 1.40 [95% CI 1.11–1.77]).

Conclusions

Our study shows that DM patients hospitalised with AMI and on chronic GLP-1 RA and/or SGLT-2i therapy have a better in-hospital clinical outcome than DM patients without them.

Funding Acknowledgement

Type of funding sources: None.

Toll-like receptor 2 promotes breast cancer progression and resistance to chemotherapy

Cancer stem cells (CSCs) are the main drivers of disease progression and chemotherapy resistance in breast cancer. Tumor progression and chemoresistance might then be prevented by CSC-targeted therapies. We previously demonstrated that Toll-like Receptor (TLR)2 is overexpressed in CSCs and fuels their self-renewal. Here, we show that high TLR2 expression is linked to poor prognosis in breast cancer patients, therefore representing a candidate target for breast cancer treatment. By using a novel mammary cancer-prone TLR2^KO mouse model, we demonstrate that TLR2 is required for CSC pool maintenance and for regulatory T cell induction. Accordingly, cancer-prone TLR2^KO mice display delayed tumor onset and increased survival. Transplantation of TLR2^WT and TLR2^KO cancer cells in either TLR2^WT or TLR2^KO hosts shows that tumor initiation is mostly sustained by TLR2 expression in cancer cells. TLR2 host deficiency partially impairs cancer cell growth, implying a pro-tumorigenic effect of TLR2 expression in immune cells. Finally, we demonstrate that doxorubicin-induced release of HMGB1 activates TLR2 signaling in cancer cells, leading to a chemotherapy-resistant phenotype. Unprecedented use of TLR2 inhibitors in vivo reduces tumor growth and potentiates doxorubicin efficacy with no negative impact on the host immune system, opening new perspectives for the treatment of breast cancer patients.

Sex-specific cell types and molecular pathways drive fibro-calcific aortic valve stenosis

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Fondazione Gigi e Pupa Ferrari ONLUS

Background

Aortic stenosis (AS) is the most common valve disorder characterized by fibro-calcific remodeling of valve leaflets. Recent evidence indicated that there is a sex-related difference in AS development and progression. Fibrotic remodeling is peculiar of women's aortic valve, while men's aortic leaflets are more calcified than in women.

Purpose

To assess aortic valve fibrosis (AVF) in a severe AS cohort using non-invasive diagnostic tools and determine whether sex-specific pathological pathways and cell types are associated with severe AS.

Methods

We have included 28 men and 28 women matched for age with severe AS who underwent Doppler echocardiography and cardiac contrast-enhanced computed tomography (CT) before intervention. The calcium and fibrosis volumes were assessed and quantified using the ImageJ thresholding method, indexed calcium and fibrosis volume were calculated by dividing the volume by the aortic annular area. Differentially expressed genes and functional inferences between women and men's aortic valves were carried out on a publicly available microarray-based gene expression dataset (GSE102249). Cell types enrichment analysis in stenotic aortic valve tissues was used to reconstruct the sex-specific cellular composition of stenotic aortic valves.

Results

We confirmed that women had significantly lower aortic valve calcium content compared to men, while fibrotic tissue composition was significantly higher in women than men. We identified that the expression profile of human stenotic aortic valves is sex-dependent. Pro-fibrotic processes were prevalent in women, while pro-inflammatory ones, linked to the immune response system, were enhanced in men. Cell-type enrichment analysis showed that mesenchymal cells were over-represented in AS valves of women, whereas signatures for monocytes, macrophages, T and B cells were enriched men ones.

Conclusions

Our data provide the basis that the fibro-calcific process of the aortic valve is sex-specific, both at gene expression and cell type level. The quantification of aortic valve fibrosis by CT could make it possible to perform population-based studies and non-invasive assessment of novel therapies to reduce or halt sex-related calcific aortic valve stenosis (CAVS) progression, acting in an optimal window of opportunity early in the course of the disease.

Unravelling sex-dependent mechanisms in calcific aortic valve stenosis

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Italian Ministry of Health

Background

Calcific aortic valve stenosis (CAVS) is the most common heart valve disease that affects 3% of the population. CAVS is a progressive, multifactorial disorder driven by several cellular and molecular pathological processes. Currently, there is no pharmacological therapy able to prevent CAVS progression. Little is known about the sex-related difference in molecular mechanisms. Recent studies reported that men showed a higher aortic valve calcium load than women, which in turn, developed more fibrosis in the stenotic aortic valve leaflets. Hence, it has been hypothesized that the mechanisms underlying CAVS progression could be different between the two sexes.

Purpose

To investigate sex-differences in CAVS molecular pathways, finding new sex-related pharmacological targets.

Methods

Valve interstitial cells (VIC) were isolated from 26 patients who underwent aortic valve replacement for aortic valve stenosis. RNA, extracted from VICs, was sequenced by third generation sequencing technology. We performed pro-fibrotic (TGFβ) treatment for 5 days and we evaluated soluble collagen expression by a colorimetric assay and αSMA expression by western blot. We evaluated extracellular calcium extent by a colorimetric assay on VICs exposed to pro-calcific (inorganic phosphate) medium for 7 days. We assessed the mitochondrial damage with mitoSOX staining by Imagestream.

Results

The gene expression analysis from sequenced VICs revealed 65 genes upregulated in men and 89 genes upregulated in women. The functional analysis showed that the TGFβ signaling resulted enriched in woman VICs, while the mitochondrial related genes were upregulated in man VICs. Only woman VICs secreted higher amount of collagen under TGFβ treatment respect to the untreated (1.22±0.03 fold change (FC) vs. untreated, p&lt;0.001). αSMA expression (marker of VICs activation) was significantly higher both in men and women exposed to different concentrations of TGFβ (TGFβ 5ng/ml: 1.88±0.34 in men and 2.66±0.32 in women, FC vs. untreated, p=0.003 and p&lt;0.0001, respectively; TGFβ 10ng/ml: 2.96±0.55 in men and 2.16±0.35 in women, FC vs. untreated, p=0.0003 and p=0.0006, respectively). The calcification potential of VICs exposed to pro-calcific medium was higher in men than in women (8.23±0.45 vs. 4.69±0.59 FC vs. untreated, respectively, p&lt;0.0001). The mitochondrial superoxide formation in man VICs was higher than in woman VICs at steady state (51.0±2.1% vs. 29.5±0.9% of positive cells, respectively, p&lt;0.0001)

Conclusion

CAVS progression seems to be driven by sex-dependent molecular pathways activation. In particular, pro-fibrotic pathways are upregulated in women, while pro-calcific pathways and mitochondrial damage in men. Our data pave the way to sex-dependent pharmacological target research, aiming to treat CAVS patients.

Understanding Aberrant Signaling to Elude Therapy Escape Mechanisms in Myeloproliferative Neoplasms

Aberrant signaling in myeloproliferative neoplasms may arise from alterations in genes coding for signal transduction proteins or epigenetic regulators. Both mutated and normal cells cooperate, altering fragile balances in bone marrow niches and fueling persistent inflammation through paracrine or systemic signals. Despite the hopes placed in targeted therapies, myeloid proliferative neoplasms remain incurable diseases in patients not eligible for stem cell transplantation. Due to the emergence of drug resistance, patient management is often very difficult in the long term. Unexpected connections among signal transduction pathways highlighted in neoplastic cells suggest new strategies to overcome neoplastic cell adaptation.

Extracellular HSP90 Machineries Build Tumor Microenvironment and Boost Cancer Progression

HSP90 is released by cancer cells in the tumor microenvironment where it associates with different co-chaperones generating complexes with specific functions, ranging from folding and activation of extracellular clients to the stimulation of cell surface receptors. Emerging data indicate that these functions are essential for tumor growth and progression. The understanding of the exact composition of extracellular HSP90 complexes and the molecular mechanisms at the basis of their functions in the tumor microenvironment may represent the first step to design innovative diagnostic tools and new effective therapies. Here we review the impact of extracellular HSP90 complexes on cancer cell signaling and behavior.

Sex difference in aortic valve fibrosis assessed by contrast-enhanced computed tomography in severe aortic stenosis

Background

Aortic stenosis (AS) is characterized by fibro-calcific remodeling of aortic valve leaflets. Progressive aortic valve calcification (AVC) occurs in both sexes and cardiac computed tomography (CT) is recognized as a high-quality technique for AVC evaluation. To date, sex-specific CT thresholds of AVC have been implemented in clinical practice since it is now recognized that women have less AVC burden than men. In addition, recent evidences indicate that women have more fibrotic remodeling of aortic valve leaflet compared to men.

Purpose

Aortic valve fibrosis (AVF) being a significant contributor to valve gradient, we sought to evaluate the difference in AVF burden between men and women with severe AS using contrast-enhanced CT.

Methods

We included 56 patients matched for age and sex with severe AS. All patients underwent Doppler echocardiography and cardiac CT before intervention. Contrast attenuation values (Hounsfield Units, HU) and contrast-to-noise ratio were measured at the level of the ascending aorta. Total AVF was assessed based on HU ranging between 30 and 350, adjusting the upper threshold by increments of 25 HU in either direction until blood pool was not highlighted. Indexed contrast-enhanced CT calcium volume (iAVC) and fibrosis volume (iAVF) were calculated dividing the volumes by the aortic annular area. Fibro-calcific ratio was calculate dividing iAVF by iAVC volumes.

Results

There was no difference between men and women in major cardiovascular risk factors, valve phenotype (bicuspid vs. tricuspid), nor pharmacological treatment. Men had higher body surface area than women (1.89±0.14 vs. 1.67±0.17 m2, respectively; p&lt;0.001), while women had lower aortic valve area than men (AVA; 0.74±0.2 vs. 0.91±0.2 cm2, respectively; p=0.007) but similar indexed AVA (0.44±0.15 vs. 0.48±0.12 cm2/m2, respectively; p=0.262). Women had significantly lower iAVC compared to men (36 [36–72] vs. 72 [67–123] mm3/cm2, respectively; p=0.03). However, iAVF was significantly higher in women compared to men (83 [78–123] vs. 63 [58–83] mm3/cm2, respectively; p=0.006). Finally, the fibro-calcific ratio, which indicates the predominance of valve fibrosis if &gt;1.0, was significantly higher in women compared to men (2.57 [2.14–7.02] vs. 0.78 [0.84–2.02], respectively; p=0.003).

Conclusions

Our study highlights for the first time a sex difference in the fibrotic content of severe AS evaluated by contrast-enhanced CT. These findings might be valuable to promote further studies on the role of sex-specific tissue composition in AS progression and outcomes.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Fondazione Gigi e Pupa Ferrari ONLUS

Targeting the extracellular HSP90 co-chaperone Morgana inhibits cancer cell migration and promotes anti-cancer immunity

Heat shock protein 90 (HSP90) is secreted by cancer cells into the extracellular milieu, where it exerts pro-tumoral activities by activating extracellular substrate proteins and triggering autocrine signals through cancer cell surface receptors. Emerging evidence indicates that HSP90 co-chaperones are also secreted and may direct HSP90 extracellular activities. In this study, we found that the HSP90 co-chaperone Morgana is released by cancer cells and, in association with HSP90, induces cancer cell migration through TLR2, TLR4, and LRP1. In syngeneic cancer mouse models, a monoclonal antibody targeting Morgana extracellular activity reduced primary tumor growth via macrophage-dependent recruitment of CD8+ T lymphocytes, blocked cancer cell migration, and inhibited metastatic spreading. Overall, this data defines Morgana as a new player in the HSP90 extracellular interactome and suggests that Morgana may regulate HSP90 activity to promote cancer cell migration and suppress anti-tumor immunity.

P4667Loss of function in PCSK9, atherogenic lipoprotein concentrations, and calcific aortic valve stenosis

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition reduces plasma concentrations of most atherogenic lipoproteins such as low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (apoB) and lipoprotein(a) [Lp(a)]. Atherogenic lipoprotein concentrations have also been linked with calcific aortic valve stenosis (CAVS).

Purpose

1) To determine the association between genetic variants in PCSK9 and lipoprotein-lipid levels, 2) to determine whether loss of function (LOF) in PCSK9 is associated with CAVS and 3) to evaluate if PCSK9 could be implicated in aortic valve interstitial cells (VICs) calcification.

Methods

We built a weighted genetic risk score (wGRS) using 10 single nucleotide polymorphisms at the PCSK9 locus associated with LDL-C in the Global Lipids Genetics Consortium. We determined the association between the wGRS and LDL-C, apoB and Lp(a)] in 9692 participants of the EPIC-Norfolk study using linear regression. We investigated the association between the LOF PCSK9 R46L variant and CAVS risk in a meta-analysis of published (three Copenhagen studies, 1463 cases and 101,620 controls) and unpublished studies (UK Biobank, 1350 cases and 349,043 controls, Malmö Diet and Cancer study, 682 cases and 5963 controls and EPIC-Norfolk, 508 cases and 20,421 controls) prospective, population-based studies using logistic regression adjusted for age and sex. We evaluated PCSK9 expression and localization in explanted aortic valves by capillary Western blot and immunohistochemistry in patients with and without CAVS. Von Kossa staining was used to visualize aortic leaflet calcium deposits. We also assessed VICs calcification potential under oxidative stress condition.

Results

In EPIC-Norfolk, the wGRS was significantly associated with TC, LDL-C, and apoB (all p<0.0001), but not with VLDL-C, HDL-C, triglycerides apoA-I, or Lp(a). Carriers of the R46L variant were at lower CAVS risk (odds ratio=0.71 (95% CI, 0.57–0.88, p<0.001)). Aortic valves of patients with aortic sclerosis (n=12) and CAVS (n=8) presented elevated PCSK9 levels (log2 fold change [FC]=+28.6±5.1, p=0.008 and FC=+39.3±15.2, p=0.02, respectively) compared to controls (n=4).In calcified leaflets, PCSK9 expression co-localized with calcium deposits. PCSK9 expression in VICs was induced by oxidative stress (FC=+2.3±0.4, p=0.02), and subsequent increment in calcification potential was observed.

Conclusion

PCSK9LOF variants are associated with lifelong reductions in non-Lp(a) apoB-containing lipoprotein levels and a lower risk of coronary artery disease and CAVS. PCSK9 is abundant in fibrotic and calcified aortic leaflets. Oxidative stress increases PCSK9 expression in VICs. These results support randomized clinical trials of PCSK9 inhibition in the prevention of CAVS.

Targeting few to help hundreds: JAK, MAPK and ROCK pathways as druggable targets in atypical chronic myeloid leukemia

Atypical Chronic Myeloid Leukemia (aCML) is a myeloproliferative neoplasm characterized by neutrophilic leukocytosis and dysgranulopoiesis. From a genetic point of view, aCML shows a heterogeneous mutational landscape with mutations affecting signal transduction proteins but also broad genetic modifiers and chromatin remodelers, making difficult to understand the molecular mechanisms causing the onset of the disease. The JAK-STAT, MAPK and ROCK pathways are known to be responsible for myeloproliferation in physiological conditions and to be aberrantly activated in myeloproliferative diseases. Furthermore, experimental evidences suggest the efficacy of inhibitors targeting these pathways in repressing myeloproliferation, opening the way to deep clinical investigations. However, the activation status of these pathways is rarely analyzed when genetic mutations do not occur in a component of the signaling cascade. Given that mutations in functionally unrelated genes give rise to the same pathology, it is tempting to speculate that alteration in the few signaling pathways mentioned above might be a common feature of pathological myeloproliferation. If so, targeted therapy would be an option to be considered for aCML patients.

[Castleman's disease in childhood: a case report]

We report a case of Castleman's disease in 3-month old infant with cervical swelling, treated with surgical excision. This case is interesting because of the rarity of this disease in childhood, of the cervical localization and of the complexity of long- term follow-up.

[CVS-cardiac thrombosis related in a child with an intracranial germinoma]

We report a case of a CVC infection with a grave cardiac thrombosis in a child afflicted with intracranial functioning germinoma. During the second chemotherapeutic cycle we found a positive blood culture and a partial CVC occlusion; echocardiography showed a 2 cm diameter interatrial thrombus. After removal of the CVC a voluminous thrombus in the right atrium persisted. The profibrinolytic factor's concentration was normal, and so we preferred to use aspirin, the most common antiplatelet agent, combined with antibiotic and antimycotis therapy. This treatment allowed us to observe the disappearance of the thrombus by 25 days.