Search

Hereditary hemorrhagic telangiectasia (HHT) is a rare genetic disease caused by mutations affecting components of bone morphogenetic protein (BMP)/transforming growth factor-β (TGF-β) signaling in endothelial cells. This disorder is characterized by arteriovenous malformations that are prone to rupture, and the ensuing hemorrhages are responsible for iron-deficiency anemia. Along with activin receptor-like kinase (ALK1), mutations in endoglin are associated with the vast majority of HHT cases. In this study, we characterized the zebrafish endoglin locus and demonstrated that it produces two phylogenetically conserved protein isoforms. Functional analysis of a CRISPR/Cas9 zebrafish endoglin mutant revealed that Endoglin deficiency is lethal during the course from juvenile stage to adulthood. Endoglin-deficient zebrafish develop cardiomegaly, resulting in heart failure and hypochromic anemia, which both stem from chronic hypoxia. endoglin mutant zebrafish display structural alterations of the developing gills and underlying vascular network that coincide with hypoxia. Finally, phenylhydrazine treatment demonstrated that lowering hematocrit/blood viscosity alleviates heart failure and enhances the survival of Endoglin-deficient fish. Overall, our data link Endoglin deficiency to heart failure and establish zebrafish as a valuable HHT model., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)

Among the different chemotherapies available, genotoxic drugs are widely used. In response to these drugs, particularly doxorubicin, tumor cells can enter into senescence. Chemotherapy‑induced senescence (CIS) is a complex response. Long described as a definitive arrest of cell proliferation, the present authors and various groups have shown that this state may not be complete and could allow certain cells to reproliferate. The mechanism could be due to the activation of new signaling pathways. In the laboratory, the proteins involved in these pathways and triggering cell proliferation were studied. The present study determined a new role for anterior gradient protein 2 (AGR2) in vivo in patients and in vitro in a senescence escape model. AGR2's implication in breast cancer patients and proliferation of senescent cells was assessed based on a SWATH‑MS proteomic study of patients' samples and RNA interference technology on cell lines. First, AGR2 was identified and it was found that its concentration is higher in the serum of patients with breast cancer and that this high concentration is associated with metastasis occurrence. An inverse correlation between intratumoral AGR2 expression and the senescence marker p16 was also observed. This observation led to the study of the role of AGR2 in the CIS escape model. In this model, it was found that AGR2 is overexpressed in cells during senescence escape and that its loss considerably reduces this phenomenon. Furthermore, it was shown that the extracellular form of AGR2 stimulated the reproliferation of senescent cells. The power of proteomic analysis based on the SWATH‑MS approach allowed the present study to highlight the mammalian target of rapamycin (mTOR)/AKT signaling pathway in the senescence escape mechanism mediated by AGR2. Analysis of the two signaling pathways revealed that AGR2 modulated RICTOR and AKT phosphorylation. All these results showed that AGR2 expression in sera and tumors of breast cancer patients is a marker of tumor progression and metastasis occurrence. They also showed that its overexpression regulates CIS escape via activation of the mTOR/AKT signaling pathway.

Background: LRP-1 is a multifunctional scavenger receptor belonging to the LDLR family. Due to its capacity to control pericellular levels of various growth factors and proteases, LRP-1 plays a crucial role in membrane proteome dynamics, which appears decisive for tumor progression., Methods: LRP-1 involvement in a TNBC model was assessed using an RNA interference strategy in MDA-MB-231 cells. In vivo, tumorigenic and angiogenic effects of LRP-1-repressed cells were evaluated using an orthotopic xenograft model and two angiogenic assays (Matrigel ® plugs, CAM). DCE-MRI, FMT, and IHC were used to complete a tumor longitudinal follow-up and obtain morphological and functional vascular information. In vitro, HUVECs' angiogenic potential was evaluated using a tumor secretome, subjected to a proteomic analysis to highlight LRP-1-dependant signaling pathways., Results: LRP-1 repression in MDA-MB-231 tumors led to a 60% growth delay because of, inter alia, morphological and functional vascular differences, confirmed by angiogenic models. In vitro, the LRP-1-repressed cells secretome restrained HUVECs' angiogenic capabilities. A proteomics analysis revealed that LRP-1 supports tumor growth and angiogenesis by regulating TGF-β signaling and plasminogen/plasmin system., Conclusions: LRP-1, by its wide spectrum of interactions, emerges as an important matricellular player in the control of cancer-signaling events such as angiogenesis, by supporting tumor vascular morphology and functionality.

In humans, several members of the CEACAM receptor family have been shown to interact with intestinal pathogens in an inflammatory context. While CEACAMs have long been thought to be only present in mammals, recent studies have identified ceacam genes in other vertebrates, including teleosts. The function of these related genes remains however largely unknown. To gain insight into the function of CEACAM proteins in fish, we undertook the study of a putative member of the family, CEACAMz1, identified in Danio rerio. Sequence analysis of the ceacamz1 gene product predicted a GPI-anchored extracellular protein containing eleven immunoglobulin domains but revealed no evident orthology with human CEACAMs. Using a combination of RT-PCR analyses and in situ hybridization experiments, as well as a fluorescent reporter line, we showed that CEACAMz1 is first expressed in discrete cells on the ventral skin of zebrafish larvae and later on in the developing gills. This distribution remains constant until juvenile stage is reached, at which point CEACAMz1 is almost exclusively expressed in gills. We further observed that at late larval stages, CEACAMz1-expressing cells mostly localize on the afferent side of the branchial filaments and possibly in the inter-lamellar space. Using immunolabelling and 3D-reconstructions, we showed that CEACAMz1 is expressed in cells from the uppermost layer of skin epidermis. These cells are embedded within the keratinocytes pavement and we unambiguously identified them as proton-pump rich ionocytes (HR cells). As the expression of ceacamz1 is turned on concomitantly to that of other known markers of HR cells, we propose that ceacamz1 may serve as a novel marker of mature HR cells from the zebrafish epidermis., Competing Interests: The authors have declared that no competing interests exist.

Hypertension is associated with excessive reactive oxygen species (ROS) production in vascular cells. Mitochondria undergo fusion and fission, a process playing a role in mitochondrial function. OPA1 is essential for mitochondrial fusion. Loss of OPA1 is associated with ROS production and cell dysfunction. We hypothesized that mitochondria fusion could reduce oxidative stress that defect in fusion would exacerbate hypertension. Using (a) Opa1 haploinsufficiency in isolated resistance arteries from Opa1 +/- mice, (b) primary vascular cells from Opa1 +/- mice, and (c) RNA interference experiments with siRNA against Opa1 in vascular cells, we investigated the role of mitochondria fusion in hypertension. In hypertension, Opa1 haploinsufficiency induced altered mitochondrial cristae structure both in vascular smooth muscle and endothelial cells but did not modify protein level of long and short forms of OPA1. In addition, we demonstrated an increase of mitochondrial ROS production, associated with a decrease of superoxide dismutase 1 protein expression. We also observed an increase of apoptosis in vascular cells and a decreased VSMCs proliferation. Blood pressure, vascular contractility, as well as endothelium-dependent and -independent relaxation were similar in Opa1 +/- , WT, L-NAME-treated Opa1 +/- and WT mice. Nevertheless, chronic NO-synthase inhibition with L-NAME induced a greater hypertension in Opa1 +/- than in WT mice without compensatory arterial wall hypertrophy. This was associated with a stronger reduction in endothelium-dependent relaxation due to excessive ROS production. Our results highlight the protective role of mitochondria fusion in the vasculature during hypertension by limiting mitochondria ROS production., (© 2021 Federation of American Societies for Experimental Biology.)

While it is now accepted that nutrition can influence the epigenetic modifications occurring in colorectal cancer (CRC), the underlying mechanisms are not fully understood. Among the tumor suppressor genes frequently epigenetically downregulated in CRC, the four related genes of the UNC5 family: UNC5A , UNC5B , UNC5C and UNC5D encode dependence receptors that regulate the apoptosis/survival balance. Herein, in a mouse model of CRC, we found that the expression of UNC5A , UNC5B and UNC5C was diminished in tumors but only in mice subjected to a High Carbohydrate Diet (HCD) thus linking nutrition to their repression in CRC. O -GlcNAcylation is a nutritional sensor which has enhanced levels in CRC and regulates many cellular processes amongst epigenetics. We then investigated the putative involvement of O -GlcNAcylation in the epigenetic downregulation of the UNC5 family members. By a combination of pharmacological inhibition and RNA interference approaches coupled to RT-qPCR (Reverse Transcription-quantitative Polymerase Chain Reaction) analyses, promoter luciferase assay and CUT&RUN (Cleavage Under Target & Release Using Nuclease) experiments, we demonstrated that the O -GlcNAcylated form of the histone methyl transferase EZH2 (Enhancer of Zeste Homolog 2) represses the transcription of UNC5A in human colon cancer cells. Collectively, our data support the hypothesis that O -GlcNAcylation could represent one link between nutrition and epigenetic downregulation of key tumor suppressor genes governing colon carcinogenesis including UNC5A .

In primary cells, senescence induces a permanent proliferative arrest to prevent the propagation of malignant cells. However, the outcome of senescence is more complex in advanced cancer cells where senescent states are heterogeneous. Here, this heterogeneity is discussed and it is proposed that proteomic analysis should be used to identify specific signatures of cancer cells that use this pathway as an adaptive mechanism. Since senescent cells produce an inflammatory secretome, MRM approaches and quantification with internal standards might be particularly suited to follow the expression of the corresponding markers in body fluids. Used in combination with imaging medical technics, a better characterization of senescence heterogeneity should help to monitor the response to chemotherapy treatment., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Senescence is activated in response to chemotherapy to prevent the propagation of cancer cells. In transformed cells, recent studies have shown that this response is not always definitive and that persistent populations can use senescence as an adaptive pathway to restart proliferation and become more aggressive. Here we discuss the results showing that an incomplete and heterogeneous senescence response plays a key role in chemotherapy resistance. Surviving to successive chemotherapy regimens, chronically existing senescent cells can create a survival niche through paracrine cooperations with neighboring cells. This favors chemotherapy escape of premalignant clones but might also allow the survival of adjacent clones presenting a lower fitness. A better characterization of senescence heterogeneity in transformed cells is therefore necessary. This will help us to understand this incomplete response to therapy and how it could generate clones with increased tumor capacity leading to disease relapse.

Senescence is a tumor-suppressive mechanism induced by telomere shortening, oncogenes, or chemotherapy treatment. Although it is clear that this suppressive pathway leads to a permanent arrest in primary cells, this might not be the case in cancer cells that have inactivated their suppressive pathways. We have recently shown that subpopulations of cells can escape chemotherapy-mediated senescence and emerge as more transformed cells that induce tumor formation, resist anoikis, and are more invasive. In this study, we characterized this emergence and showed that senescent cells favor tumor growth and metastasis, in vitro and in vivo. Senescence escape was regulated by secreted proteins produced during emergence. Among these, we identified thrombospondin-1 (TSP1), a protein produced by senescent cells that prevented senescence escape. Using SWATH quantitative proteomic analysis, we found that TSP1 can be detected in the serum of patients suffering from triple-negative breast cancer and that its low expression was associated with treatment failure. The results also indicate that senescence escape is explained by the emergence of CD47 low cells that express a reduced level of CD47, the TSP1 receptor. The results show that CD47 expression is regulated by p21waf1. The cell cycle inhibitor was sufficient to maintain senescence since its downregulation in senescent cells increased cell emergence. This leads to the upregulation of Myc, which then binds to the CD47 promoter to repress its expression, allowing the generation of CD47 low cells that escape the suppressive arrest. Altogether, these results uncovered a new function for TSP1 and CD47 in the control of chemotherapy-mediated senescence.

Background: Life course epidemiology is now an established field in social epidemiology; in sociodemography, the quantitative analysis of biographies recently experienced significant trend from event history analysis to sequence analysis. The purpose of this article is to introduce and adapt this methodology to a social epidemiology question, taking the example of the impact of HIV diagnosis on Sub-Saharan migrants' residential trajectories in the Paris region., Methods: The sample consists of 640 migrants born in Sub-Saharan Africa receiving HIV care. They were interviewed in healthcare facilities in the Paris region within the PARCOURS project, conducted from 2012 to 2013, using life event history calendars, which recorded year by year their health, family and residential histories. We introduce a two-step methodological approach consisting of (1) sequence analysis by optimal matching to build a typology of migrants' residential pathways before and after diagnosis, and (2) a Cox model of the probability to experience changes in the residential situation., Results: The seven-clusters typology shows that for a majority, the HIV diagnosis did not entail changes in residential situation. However 30% of the migrants experienced a change in their residential situation at time of diagnosis. The Cox model analysis reveals that this residential change was in fact moving in with one's partner (HR 2.99, P<0.000) rather than network rejection., Conclusion: This original combination of sequence analysis and Cox models is a powerful process that could be applied to other themes and constitutes a new approach in the life course epidemiology toolbox., Trial Registration Number: NCT02566148., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Senescence is a tumor suppressive mechanism that induces a permanent proliferative arrest in response to an oncogenic insult or to the genotoxic stress induced by chemotherapy. We have recently described that some cells can escape this arrest, either because senescence was incomplete or as a consequence of a phenotypic adaptation. Malignant cells which resisted senescence emerged as more transformed cells that resist anoikis and rely on survival pathways activated by Akt and Mcl-1. In this study, we further characterize senescence escape, investigating how emergent cells could reproliferate. During the initial step of chemotherapy-induced senescence (CIS), we found that cyclin D1 was upregulated and that cell emergence was prevented when its main partner cdk4 was inactivated. Results indicate that this kinase induced the upregulation of the EZH2 methylase, a component of the polycomb PRC2 complex. Downregulated during the early step of treatment, the methylase was reactivated in clones that escaped senescence. The inactivation of EZH2, either by siRNA or by specific inhibitors, led to a specific inhibition of cell emergence. We used quantitative proteomic analysis to identify new targets of the methylase involved in senescence escape. We identified proteins involved in receptor endocytosis and described new functions for the AP2M1 protein in the control of chemotherapy-mediated senescence. Our results indicate that AP2M1 is involved in the transmission of secreted signals produced by senescent cells, suggesting that this pathway might regulate specific receptors involved in the control of CIS escape. In light of these results, we therefore propose that the cdk4-EZH2-AP2M1 pathway plays an important role during chemotherapy resistance and senescence escape. Since targeted therapies are available against these proteins, we propose that they should be tested in the treatment of colorectal or breast cancers that become resistant to first-line genotoxic therapies.

With the increase in asylum-related immigration since 2015, understanding how immigrants settle in a new country is at the centre of social and political debate in European countries. The objective of this study is to determine whether the necessary time to settle for Sub-Saharan Africa immigrants in France depends more on pre-migratory characteristics or on the structural features of the host society. Taking a capability approach, we define settlement as the acquisition of three basic resources: a personal dwelling, a legal permit of a least 1 year and paid work. We use data from the PARCOURS survey, a life-event history survey conducted from 2012 to 2013 that collected 513 life histories of Sub-Saharan African immigrants living in France. Situations regarding housing, legal status and activity were documented year by year since the arrival of the respondent. We use a Kaplan-Meier analysis and chronograms to describe the time needed for settlement, first for each resource (personal dwelling, legal permit and paid work) and then for the combined indicator of settlement. Discrete-time logistic regressions are used to model the determinants of this settlement process. Overall, women and men require 6 and 7 years (medians), respectively, to acquire basic resources in France. This represents a strikingly long period of time in which immigrants lack basic security. The settlement process varies according to gender, but very few sociodemographic factors influence settlement dynamics. Therefore, the length of the settlement process may be due to structural features of the host society.

Background: Few studies have focused on the influence of retirement on dietary behaviors. Our study aimed at assessing the associations between transition to retirement and changes in dietary intake in French adults, particularly according to spousal retirement and baseline income., Methods: This prospective study included 577 French participants from the NutriNet-Santé cohort who retired over a 5-year follow-up (2009-2014 or 2010-2015). At baseline and every year, dietary intakes were assessed using 24 h records. Repeated measures of dietary intake were analysed using mixed models adjusted for energy with random effects of time and period (before and after retirement) to assess changes following retirement for each gender., Results: After retirement, intakes of saturated fatty acids and sodium increased in both genders. Women showed specific changes after retirement: decrease in the score of adherence to recommendations and in intakes of fruits, proteins, vitamins; increase in intakes of fatty sweet products. In men with the lowest income at baseline, specific changes in intake were associated with retirement such as decrease in intake of dairy products and increase in intake of lipids., Conclusions: Transition to retirement was associated with unhealthier dietary intakes. These results may help defining interventions during this vulnerable life-period., Trial Registration: This study was conducted according to guidelines laid down in the Declaration of Helsinki and all procedures were approved by the Institutional Review Board of the French Institute for Health and Medical Research (IRB Inserm No. 0000388FWA00005831) and the French Data Protection Authority (Commission Nationale Informatique et Libertés No. 908450 and No. 909216). Electronic informed consents were obtained from all participants.

Background: Migrants account for 35% of HIV diagnoses in the European Union (ECDC/WHO 2014). Little is known about the impact of such a lifelong infection diagnosis on lives that are already disrupted by migration. In this paper, we assess the impact of HIV diagnosis on activity, union, well-being among African migrants living in France, the second group most affected by HIV after MSM. We compare it with the impact of the diagnosis of Hepatitis B, another lifelong infection affecting African migrants., Methods: We use the ANRS PARCOURS survey, a retrospective life-event survey led in 2012-2013 in 74 health structures in Paris greater area which collected 926 life histories of Sub-Saharan migrants living with HIV and 779 with Hepatitis B. We modelled the probability year by year since 18 years of age until data collection to lose one's activity, to experience a conjugal break up and degradation of well-being and we estimated the impact of migration and of HIV and Hepatitis B diagnoses on these probabilities, after adjustment on other factors, thanks to discrete-time logistic regressions., Results: Migration entailed loss of activity and conjugal break up, though HIV diagnosis after migration did not statistically impact on these outcomes. Yet HIV diagnosis had a massive negative impact on well-being (aOR = 11.31 [4.64-27.56] for men and 5.75 [2.79-11.86] for women). This negative impact on well-being tended to diminish for persons diagnosed after 2004. The negative impact of HIV diagnosis on African migrants' well-being seems to be attenuated in the last decade, which hints at a normalization of the subjective experience of HIV diagnosis., Competing Interests: The authors have declared that no competing interests exist.

Epidemiologic studies have demonstrated that cardiovascular risk is not only determined by conventional risk factors in adulthood, but also by early life events which may reprogram vascular function. To evaluate the effect of maternal diabetes on fetal programming of vascular tone in offspring and its evolution during adulthood, we investigated vascular reactivity of third order mesenteric arteries from diabetic mother offspring (DMO) and control mother offspring (CMO) aged 3 and 18 months. In arteries isolated from DMO the relaxation induced by prostacyclin analogues was reduced in both 3- and 18-month old animals although endothelium (acetylcholine)-mediated relaxation was reduced in 18-month old DMO only. Endothelium-independent (sodium nitroprusside) relaxation was not affected. Pressure-induced myogenic tone, which controls local blood flow, was reduced in 18-month old CMO compared to 3-month old CMO. Interestingly, myogenic tone was maintained at a high level in 18-month old DMO even though agonist-induced vasoconstriction was not altered. These perturbations, in 18-months old DMO rats, were associated with an increased pMLC/MLC, pPKA/PKA ratio and an activated RhoA protein. Thus, we highlighted perturbations in the reactivity of resistance mesenteric arteries in DMO, at as early as 3 months of age, followed by the maintenance of high myogenic tone in older rats. These modifications are in favour of excessive vasoconstrictor tone. These results evidenced a fetal programming of vascular functions of resistance arteries in adult rats exposed in utero to maternal diabetes, which could explain a re-setting of vascular functions and, at least in part, the occurrence of hypertension later in life.

Data collected at household level in censuses are used for a wide range of purposes including practical planning and academic analysis of changing social conditions. Comparability is a core demographic value, and to understand the limits of the comparability of census data across time and space, it is important to recognise if, how and why, concepts and definitions change between censuses. This paper examines definitions of the household in censuses in England and Wales (E&W) and France from 1960 to 2012 in order to investigate how census definitions have changed and to examine the drivers of such changes. Two research methods were used: (1) longitudinal analyses of census documentation since the 1960s and (2) in-depth interviews with key informants oriented around respondents' roles in the collection and/or use of household data from censuses and surveys. We identify two contrasting national approaches to the data collection exercise that is called a census, which reflect political and institutional differences. These differences call into question the comparability of some aspects of census data across national boundaries, despite increased harmonisation of approaches to data collection. By comparing the evolution of the definitions of the "household" in censuses, we develop insight into the diversity of the priorities of census commissioners and designers, and consider the broader implications of this for producing comparable data.

This paper assesses the relationship between gender and HIV-related stigma experiences among people living with HIV (PLHIV) - enacted and anticipated stigma - and PLHIV caregivers - courtesy stigma - in Northern Thailand, along with the underlying reasons for stigmatising attitudes towards PLHIV - instrumental and symbolic stigma - expressed in the general population. We used data from the Living With Antiretrovirals (LIWA) study conducted on all PLHIV receiving antiretroviral treatment in four district hospitals in Northern Thailand (n = 513) and on a community sample of adults from the general population (n = 500). Women living with HIV and female caregivers of PLHIV reported higher rates of HIV-related stigma experiences than men. Gender interacted with other predictors - the period of HIV diagnosis and age - to increase the level of stigma experienced. Among the general population, attitudes of contact avoidance were infrequent. However, stereotypes depicting PLHIV as blameworthy were highly pervasive, with women perceived as the "victims" of their spouse's irresponsible sexual behaviours. In this context, women were yet more often subjected to HIV-related stigma than men, in particular women diagnosed in the pre-antiretroviral therapy era and younger female caregivers. The role of gender in shaping disparities in HIV-related stigma experiences is discussed.

In vertebrates, haematopoietic stem/progenitor cells (HSPCs) first emerge in the aorta-gonad-mesonephros (AGM) before colonizing transitory and subsequently definitive haematopoietic organs allowing haematopoiesis throughout adult life. Here we identify an unexpected primitive macrophage population accumulated in the dorsal mesenteric mesoderm surrounding the dorsal aorta of the human embryo and study its function in the transparent zebrafish embryo. Our study reveals dynamic interactions occurring between the HSPCs and primitive macrophages in the AGM. Specific chemical and inducible genetic depletion of macrophages or inhibition of matrix metalloproteinases (Mmps) leads to an accumulation of HSPCs in the AGM and a decrease in the colonization of haematopoietic organs. Finally, in vivo zymography demonstrates the function of primitive macrophages in extracellular matrix degradation, which allows HSPC migration through the AGM stroma, their intravasation, leading to the colonization of haematopoietic organs and the establishment of definitive haematopoiesis.