Genetic lineage tracing reveals poor angiogenic potential of cardiac endothelial cells

AIMS

Cardiac ischaemia does not elicit an efficient angiogenic response. Indeed, lack of surgical revascularization upon myocardial infarction results in cardiomyocyte death, scarring, and loss of contractile function. Clinical trials aimed at inducing therapeutic revascularization through the delivery of pro-angiogenic molecules after cardiac ischaemia have invariably failed, suggesting that endothelial cells in the heart cannot mount an efficient angiogenic response. To understand why the heart is a poorly angiogenic environment, here we compare the angiogenic response of the cardiac and skeletal muscle using a lineage tracing approach to genetically label sprouting endothelial cells.

METHODS AND RESULTS

We observed that overexpression of the vascular endothelial growth factor in the skeletal muscle potently stimulated angiogenesis, resulting in the formation of a massive number of new capillaries and arterioles. In contrast, response to the same dose of the same factor in the heart was blunted and consisted in a modest increase in the number of new arterioles. By using Apelin-CreER mice to genetically label sprouting endothelial cells we observed that different pro-angiogenic stimuli activated Apelin expression in both muscle types to a similar extent, however, only in the skeletal muscle, these cells were able to sprout, form elongated vascular tubes activating Notch signalling, and became incorporated into arteries. In the heart, Apelin-positive cells transiently persisted and failed to give rise to new vessels. When we implanted cancer cells in different organs, the abortive angiogenic response in the heart resulted in a reduced expansion of the tumour mass.

CONCLUSION

Our genetic lineage tracing indicates that cardiac endothelial cells activate Apelin expression in response to pro-angiogenic stimuli but, different from those of the skeletal muscle, fail to proliferate and form mature and structured vessels. The poor angiogenic potential of the heart is associated with reduced tumour angiogenesis and growth of cancer cells.

Abstract P6-07-05: Interactions between adipocyte stem cells and normal or tumoral mammary epithelial cells. Potantial role of BRCA status and estrogen pathway

Prophylactic mastectomies are more and more frequent. As a result, breast reconstruction is also more frequent and mammary lipofilling often used to improve the aesthetic results. Contradictory cliniacal data have been published concerning the risk of breast cancer after using this technique. It is possible that Adipose-Derived Stem / Stromal Cells (ADSC or ASC), present in the lipofilling may interact with normal or tumoral epithelial mammary cells.

In this context, we studied the effect of conditioned media of human ASC on different tumor breast lines (MCF7, T47D, ZR75-1, SKBR3, SUM159). The ASCs were extracted from non-cancer patients with identical body mass index (BRCA1 and BRCA2 mutated or wild-type).

We observed that the conditioned media of ASC induced the proliferation of luminal, Her2 and basal-like tumor breast lines. This proliferative effect is more important when ASCs are differentiated and the BRCA mutation status has no impact on it. Finally, we have demonstrated an estrogen signaling within the ASCs which is set up during their differentiation. Differentiated ASCs express ERα and produce 17β-estradiol (E2). This estrogenic pathway seems to be established independently of the BRCA mutational status. The proliferative effect on luminal mammary lines induced by conditioned media of ASC could pass through this estrogenic signaling, but remains to be confirmed.

These data highlight the fact that adipose-derived stem cells in mammary lipofilling should only be used after a cancer has been eliminated, as there are still some uncertainties concerning their implication on carcinogenesis.

Citation Format: Benderra M-A, Zaoui M, Atlan M, Ferrand N, Denis JA, Leban M, Lamari F, Larsen AK, Sabbah M, Gligorov J. Interactions between adipocyte stem cells and normal or tumoral mammary epithelial cells. Potantial role of BRCA status and estrogen pathway [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-07-05.

Endocrine Manifestations in a Monocentric Cohort of 64 Patients With Erdheim-Chester Disease

CONTEXT

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis, characterized by infiltration of foamy histiocytes in multiple organs. Endocrine involvement has mostly been described in case reports.

OBJECTIVE

We performed systematic endocrine evaluation in a large cohort of patients with ECD.

DESIGN

This was a single-center observational study conducted between October 2007 and May 2013.

SETTING

The evaluation was conducted in Pitié-Salpêtrière Hospital (Paris, France), a tertiary care hospital.

PATIENTS

Sixty-four consecutive patients with ECD (sex ratio, 3.6; mean age, 57.6 years [range, 20-80 years]). Thirty-six patients had follow-up assessments.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

Clinical, biological, and morphological evaluations of pituitary, gonadal, adrenal, and thyroid functions, as well as metabolic evaluation, were performed.

RESULTS

Diabetes insipidus was found in 33.3% of patients, frequently as the first manifestation of ECD. Anterior pituitary dysfunction was found in 91.3% of patients with full anterior pituitary evaluation, including somatotropic deficiency (78.6%), hyperprolactinemia (44.1%), gonadotropic deficiency (22.2%), thyrotropic deficiency (9.5%), and corticotropic deficiency (3.1%). Thirty-five patients (54.7%) had ≥2 anterior pituitary dysfunctional axes, rising to 69.6% (16 of 23) when only patients with complete evaluations were considered. Two patients had panhypopituitarism. Infiltration of the pituitary and stalk was found with magnetic resonance imaging in 24.4% of patients. Testicular insufficiency was found in 53.1% of patients, with sonographic testicular infiltration in 29% of men, mostly bilateral. Computed tomography adrenal infiltration was found in 39.1% of patients, and 1 case of adrenal insufficiency was observed. No patient was free of endocrine hormonal or morphological involvement. Endocrine dysfunctions were most often permanent, and new deficits appeared during follow-up.

CONCLUSION

Endocrine involvement is very frequent in ECD and should be evaluated carefully at diagnosis and during follow-up.

Evidence of cardiac myolysis in severe nonischemic heart failure and the potential role of increased wall strain

BACKGROUND

Myocyte death could play a role in heart failure (HF) irrespective of the presence of coronary artery disease. The study aimed to assess this hypothesis by use of the cardiac troponin I (cTnI) assay.

METHODS AND RESULTS

Seventy-one patients with nonischemic HF, New York Heart Association (NYHA) class II-IV, with a normal coronary angiogram and after exclusion of myocardiopathies were evaluated in the study. The control group included 9 healthy subjects and 15 patients hospitalized for severe noncardiac dyspnea. Cardiac TnI concentrations were determined at admission with a research reagent (cTnIus) characterized by a detection limit of 0.026 ng/mL and a high analytic sensitivity of 0.002 ng/mL. cTnIus levels were more than 0.026 ng/mL in 19 HF patients, ranging between 0.027 and 0.463 ng/mL, whereas no cTnIus level was detectable in the control group. With use of a reference assay, only 2 HF patients had abnormal cTnI values. Severe HF was observed in 17 of these 19 patients, assessed by NYHA class IV or by the presence of pulmonary edema. Patients with an increased cTnIus level had a more restrictive mitral Doppler pattern (P <.001) and a more distinctive left ventricular (LV) concentric remodeling (P <.0001), whereas LV ejection fraction was similar in both HF groups. The increased cTnIus level was also associated with a LV wall strain biologic marker (ie, an increased brain natriuretic peptide plasma level) (P <.001).

CONCLUSIONS

cTnI assay is a promising biochemical method for detecting cardiac myolysis in HF, independent of the presence of coronary artery disease. This subtle myolysis could be in part related to the severely increased LV wall strain.

Hydrolysis of Monothio-β-diketones. I. Monothioacetylacetone and monothiobenzoylacetone

The hydrolysis of monothioacetylacetone (4-mercaptopent-3-en-2-one) and monothiobenzoylacetone (3-mercapto-1-phenylbut-2-en-1-one) in acid solution has been studied spectrophotometrically. The half-lives were found to be 50�2 min and 124�5 min at 25� for monothioacetylacetone and monothiobenzoylacetone, respectively. The corresponding pseudo first- order rate constants are 1.39�0.05 x 10-2 and 5.59�0.14 x 10-3 min-1. The enthalpy of activation for the hydrolysis of monothiobenzoylacetone was determined as 79.5 � 4 kJ/mol.

Hydrolysis of Monothio-β-diketones. II. Hydrolysis of three fluorinated Monothio-β-diketones

The rapid decomposition of the fluorinated monothio-β-diketones RC(SH)=CHCOCF3, 4-(3?-bromophenyl)-1,1,1-trifluoro-4-mercaptobut-3-en-2- one (R = m-BrC6H4), 4-(4?-bromophenyl)-1,1,1-trifluoro-4-mercaptobut-3- en-2-one (R = p-BrC6H4) and 1,1,1-trifluoro-4-mercaptopent-3-en-2-one(R = Me), in acid solution has been shown to occur by hydrolytic cleavage to yield the ketone RCOCH3, hydrogen sulphide and probably trifluoroacetic acid. The pseudo first-order rate constants for these compounds are (8.0�0.3)x 10-3, min-1, (6.0 � 0.6) x 10-3 min-1 and 0.12�0.01 min-1, respectively. The greater vulnerability of 1,1,1- trifluoro-4-mercaptopent-3-en-2-one, compared to the other two monothio-β-diketones, towards hydrolytic cleavage is related to the nature of the R substituent in that conjugation involving the terminal aromatic ring stabilizes the monothio-β-diketone.