Histone H3 trimethylation at lysine 36 guides m6A RNA modification co-transcriptionally.

DNA and histone modifications have notable effects on gene expression1. Being the most prevalent internal modification in mRNA, the N6-methyladenosine (m6A) mRNA modification is as an important post-transcriptional mechanism of gene regulation2-4 and has crucial roles in various normal and pathological processes5-12. However, it is unclear how m6A is specifically and dynamically deposited in the transcriptome. Here we report that histone H3 trimethylation at Lys36 (H3K36me3), a marker for transcription elongation, guides m6A deposition globally. We show that m6A modifications are enriched in the vicinity of H3K36me3 peaks, and are reduced globally when cellular H3K36me3 is depleted. Mechanistically, H3K36me3 is recognized and bound directly by METTL14, a crucial component of the m6A methyltransferase complex (MTC), which in turn facilitates the binding of the m6A MTC to adjacent RNA polymerase II, thereby delivering the m6A MTC to actively transcribed nascent RNAs to deposit m6A co-transcriptionally. In mouse embryonic stem cells, phenocopying METTL14 knockdown, H3K36me3 depletion also markedly reduces m6A abundance transcriptome-wide and in pluripotency transcripts, resulting in increased cell stemness. Collectively, our studies reveal the important roles of H3K36me3 and METTL14 in determining specific and dynamic deposition of m6A in mRNA, and uncover another layer of gene expression regulation that involves crosstalk between histone modification and RNA methylation.

Unmet needs in mental healthcare for women with clinically significant symptoms of perinatal depression and/or anxiety during the COVID-19 pandemic.

OBJECTIVE/BACKGROUND: Unmet needs in perinatal mental healthcare are an important public health issue particularly in the context of a stressful life event such as the COVID-19 pandemic but data on the extent of this problem are needed. AIM: The aim of this study is to determine the (1) proportion of women with clinically significant symptoms of perinatal depression, anxiety or comorbid symptoms of depression and anxiety, receiving mental healthcare overall and by country and (2) factors associated with receiving mental healthcare. METHOD: Women in the perinatal period (pregnancy or up to 6 months postpartum) participating in the Riseup-PPD-COVID-19 cross-sectional study, reported on sociodemographic, social support health-related factors, and COVID-19 related factors, and on symptoms of depression (Edinburgh Postnatal Depression Scale [EPDS]) and anxiety (Generalised Anxiety Disorder [GAD-7]) using self-report questionnaires. Clinically significant symptoms were defined as EPDS ≥ 13 for depression and GAD-7 ≥ 10 for anxiety. Mental healthcare was defined as self-reported current mental health treatment. RESULTS: Of the 11 809 participants from 12 countries included in the analysis, 4 379 (37.1%) reported clinically significant symptoms of depression (n = 1 228; 10.4%; EPDS ≥ 13 and GAD-7 ⟨ 10), anxiety (n = 848; 7.2%; GAD-7 ≥ 10 and EPDS ⟨ 13) or comorbid symptoms of depression and anxiety (n = 2 303; 19.5%; EPDS ≥ 13 and GAD-7 ≥ 10). Most women with clinically significant symptoms of depression, anxiety, or comorbid symptoms of depression and anxiety were not receiving mental healthcare (89.0%). Variation in the proportion of women with clinically significant symptoms of depression and/or anxiety reporting mental healthcare was high (4.7% in Turkey to 21.6% in Brazil). Women in the postpartum (vs. pregnancy) were less likely (OR 0.72; 95% CI 0.59-0.88), whereas women with previous mental health problems (vs. no previous mental health problems) (OR 5.56; 95% CI 4.41-7.01), were more likely to receive mental healthcare. CONCLUSION: There are high unmet needs in mental healthcare for women with clinically significant symptoms of perinatal depression and/or anxiety across countries during the COVID-19 pandemic. Studies beyond the COVID-19 pandemic and covering the whole range of mental health problems in the perinatal period are warranted to understand the gaps in perinatal mental healthcare.

Intraoral primary syphilis mimicking lymphoproliferative disorder.

Syphilis can mimic, clinically and microscopically, many other diseases. By microscopy, typically syphilis presents with plasma cell infiltration, admixed with lymphocytes and macrophages, in lichenoid and/or perivascular/perineural distribution pattern. When exuberant, this inflammatory infiltrate can mimic a lymphoproliferative disorder (LPD), notably plasma cell neoplasia or lymphoma. To date, about 12 cases of secondary syphilis, all but one in extraoral location, suggesting initially a LPD, have been published. Here, to our knowledge, we report an unusual case of intraoral primary syphilis initially suggesting LPD, notably lymphoid hyperplasia (pseudolymphoma); however, mucosa-associated lymphoid tissue (MALT) lymphoma and follicular lymphoma could not be disregarded. Polyclonality of plasma cells on immunohistochemistry, in strict clinical correlation, was essential to arrive at the correct diagnosis.

Changes to women's childbirth plans during the COVID-19 pandemic and posttraumatic stress symptoms: a cross-national study.

A considerable number of women giving birth during COVID-19 pandemic reported being concerned about changes to their childbirth plans and experiences due to imposed restrictions. Research prior to the pandemic suggests that women may be more at risk of post-traumatic stress symptoms (PTSS) due to unmet expectations of their childbirth plans. Therefore, this study aimed to examine if the mismatch between women's planned birth and actual birth experiences during COVID-19 was associated with women's postpartum PTSS. Women in the postpartum period (up to 6 months after birth) across 11 countries reported on childbirth experiences, mental health, COVID-19-related factors, and PTSS (PTSD checklist DSM-5 version) using self-report questionnaires (ClinicalTrials.gov: NCT04595123). More than half (64%) of the 3532 postpartum women included in the analysis reported changes to their childbirth plans. All changes were significantly associated with PTSS scores. Participants with one and two changes to their childbirth plans had a 12% and 38% increase, respectively, in PTSS scores compared to those with no changes (Exp(ß) = 1.12; 95% CI [1.06-1.19]; p < 0.001 and Exp(ß) = 1.38; 95% CI [1.29-1.48]; p < 0.001). In addition, the effect of having one change in the childbirth plan on PTSS scores was stronger in primigravida than in multigravida (Exp(ß) = 0.86; 95% CI [0.77-0.97]; p = 0.014). Changes to women's childbirth plans during the COVID-19 pandemic were common and associated with women's postpartum PTSS score. Developing health policies that protect women from the negative consequences of unexpected or unintended birth experiences is important for perinatal mental health.

Neural correlates of face familiarity in institutionalised children and links to attachment disordered behaviour.

BACKGROUND: One of the most well-documented sequelae of early maltreatment and institutionalisation is attachment problems, including behaviours under the labels of reactive attachment disorder (RAD) and disinhibited social engagement disorder (DSED). Despite growing evidence of the neurobiological effects of institutionalisation, the neural correlates of these behavioural patterns are largely unknown. METHODS: The current study examined effects of both institutionalisation in general and attachment disordered behaviour, in particular, on brain-based markers of face processing, in 100 Portuguese children (70 currently institutionalised, 30 continuously raised by their families). Children's neural processing of caregiver's and stranger's faces was assessed with Event-Related Potentials (ERPs). RESULTS: Compared to children from the community, institutionalised children showed smaller amplitudes in the N170, to both stranger and caregiver faces. Amongst the institutionalised group, living in a setting with a higher children-to-caregivers' ratio was associated with smaller P400 amplitudes. The display of DSED symptoms was associated with a smaller P1 to both faces, as well as a reduced differentiation between faces in P400 amplitudes and smaller P400 to the stranger's face. In contrast, RAD symptoms were not associated with any ERP measures. CONCLUSIONS: Results replicate previously reported hypoactivation in institutionalised children, in a less-globally deprived setting than past work, indicating that such a pattern is associated with lack of individualised care and increased symptoms of DSED.

Brain tuberculoma in pediatric heart transplant recipient.

INTRODUCTION: Heart transplantation is the standard treatment for end-stage heart disease. Despite advances in the field, patients remain under risk of developing complications, including opportunistic infections, such as tuberculosis. We present the unprecedented case of cerebral tuberculoma in a 9-year-old heart transplant recipient. CASE SCENARIO: A 9-year-old female child, who underwent heart transplantation in December 2020, was admitted to the emergency department in September 2021 due to headache and vomiting. She had normal vital signs and a mild left hemiparesis. Laboratory findings included lymphopenia and a low C Reactive Protein and brain images showed expansive lesions. A biopsy of the intracranial lesion was performed and anatomopathological analysis was compatible with tuberculoma. After the diagnosis was established, treatment protocol for neurotuberculosis was initiated, the patient had a satisfactory clinical evolution and was discharged 22 days after admission. DISCUSSION: Clinical manifestation of tuberculosis usually occurs up to 6 months after transplantation, the findings are commonly atypical and symptoms may be mild. We could not find in medical literature any description of the disease in a heart transplant recipient as young as the one presented in this case report. We documented great response to treatment, even though conventional antituberculosis therapy may interfere with immunosuppression. CONCLUSION: Patients in the postoperative period following heart transplantation are at high risk for developing opportunistic infections such as tuberculosis, which may present with atypical symptoms. Therefore the clinician must have a high index of suspicion in order to make the correct diagnosis and promptly start treatment.

Experiences, concerns, and needs of pregnant and postpartum women during the Covid-19 pandemic in Cyprus: a cross-sectional study.

BACKGROUND: The current COVID-19 pandemic is a unique stressor with potentially challenging and negative consequences on the experiences of pregnant and postpartum women. International literature highlights the pandemic's negative impact on women's perinatal experiences. This is the first study in the scientific literature reporting on the impact of the COVID-19 pandemic, on the perinatal experiences of a large sample of women living in Cyprus. AIM: To examine the impact of the COVID-19 pandemic on the experiences, concerns and needs of pregnant and postpartum women in Cyprus. METHOD: The cross-sectional study was conducted from July 2020 to January 2021. A total of 695 women, 355 pregnant and 340 postpartum women (with infants up to 6 months of age), residing in Cyprus were surveyed. RESULTS: The great majority of the participants (80.9%) perceived the impact of the COVID-19 pandemic on their life as negative. The greatest sources of stress were identified and quantified for their impact on the participants. Our findings indicate that 74.1% of the pregnant women were concerned about changes due to COVID-19 measures impacting the presence of their family at the time of delivery, 57.2% about their newborn's health, and 43.1% about changes related to perinatal care. Postpartum women's concerns were mainly related to the welfare and health of their child (70.3%), whilst half of them (49.1%) expressed concerns about how they were going to care for their baby because of pandemic-related changes. Qualitative data revealed emerging themes as the basis of the pregnant and postpartum women's concerns and needs. CONCLUSIONS: The COVID-19 pandemic and the associated imposed measures and restrictions had adverse effects on pregnant and postpartum women's perinatal experiences in Cyprus. The women's concerns emphasized the need for the development of specialized, evidenced-based support systems which are essential particularly in pandemic-like situations, when pregnant and postpartum women are more vulnerable to isolation.

Psychopathic traits and reinforcement learning under acute stress.

OBJECTIVE: Individuals with high levels of psychopathic traits are often characterized by aberrant reinforcement learning. This type of learning, which implicates making choices that maximize rewards and minimize punishments, may be affected by acute stress. However, how acute stress affects reinforcement learning in individuals with different levels of psychopathic traits is not well-understood. Here, we investigated whether and how individual differences in psychopathic traits modulated the impact of acute stress on reward and punishment learning. METHOD: Sixty-two male participants from a university sample completed the Self-Report Psychopathy-Short Form scale and performed a reinforcement-learning task involving monetary gains and losses whilst under acute stress and control conditions. RESULTS: Individual differences in psychopathic traits modulated the impact of acute stress on behavioral performance toward obtaining gains, but not toward avoiding losses. As levels of psychopathic traits increased, the impairing effect of acute stress on reward learning decreased. Specifically, acute stress impaired performance toward seeking gains to a larger extent in individuals with lower levels of psychopathic traits than in individuals with higher levels of these traits. CONCLUSIONS: Our study indicates that psychopathic traits modulate the impact of acute stress on reward learning.

Can blood progesterone concentration identify non-pregnant buffaloes to support oestrous resynchronization?

This study compared the plasma progesterone concentrations from pregnant and non-pregnant buffaloes to identify non-pregnant females and submit cows earlier to oestrous resynchronization. Forty-four multiparous mix-breed Murrah buffaloes were selected for the study. The cows were subjected to hormonal oestrous synchronization and separated into 4 groups, P12 (pregnant, n = 8) and P18 (n = 8) at 12 and 18 days post-insemination; NP12 (non-pregnant, n = 7) and NP18 (n = 7) at 23 and 29 days after the onset of synchronization, respectively. The embryos and blood were collected, and the plasma was separated for centrifugation and used to determine progesterone concentration. Progesterone concentration was higher in P18 than P12 (p = .02) and NP18 groups (p < .001). The steroid was also increased in the P12 group compared with NP12 (p = .031). There was no difference between NP12 and NP18 (p = .906). We conclude that the plasma progesterone concentration can be an alternative to identify earlier non-pregnant buffaloes, advancing the oestrous resynchronization or natural service to improve productivity.

Protective measures feasibility for infants of low income SARS-CoV-2 positive breastfeeding mothers: a prospective multicenter cohort study.

AIM: The aim was to evaluate the feasibility of protective measures for infants of low-income SARS-CoV-2 positive breastfeeding mothers. BACKGROUND: Breastfeeding mothers with SARS-CoV-2 positive should avoid exposing the infant through protective measures (PM), but it could be challenging in a low-income population. METHODS: A prospective, multicenter study was conducted between July and October 2020 (BRACOVID). The participants were recruited at birth and interviewed through a structured questionnaire at seven and 14 days in the home environment. The feasibility of PM during breastfeeding at home was defined by guidelines recommendations (mask using, handwashing, and distancing from newborn when not breastfeeding). Three groups according to the feasibility of guidelines: complete guidelines feasibility (CG): all PM; partial guidelines feasibility (PG): at least one PM feasible; no guidelines (NG): infeasibility to all of PM. Flu-like neonatal symptoms, mothers' breastfeeding practices. We evaluated the association between PM feasibility and socioeconomic factors. RESULTS: 117 infected mothers from 17 Brazilian hospitals were enrolled. 47 (40%) mothers followed all recommendations, 14 (11.9%) could not practice at least one recommendation, and 50 (42.7%) did not execute any of them. The breastfeeding rate was 98%. Factors associated with infeasibility were monthly family income < 92.7 dollars/person, high housing density (>1 inhabitant/room), teenage mothers, responsive feeding, and poor schooling. Regarding infants' flu-like symptoms, 5% presented symptoms at fourteen days (NG group). CONCLUSION: The guidelines were not applied to infants of SARs-CoV-positive mothers in 54.6% of the dyads since the recommendations were unviable in their environments. During pandemics, we should look for feasible and effective guidelines to protect neonates from low-income populations. IMPLICATIONS FOR NURSING MANAGEMENT: Poor socioeconomic conditions lead to the unfeasibility of protective measures for infants of low-income SARS-CoV-2 positive breastfeeding mothers during the isolation period in the pandemics. The orientations and the support provided to dyad should consider the socioeconomic factors to guide feasible measures in the home environment and promote adequate protections; only an individual approach will allow a safe environment for low-income infants.

Acute stress impairs reward learning in men.

Acute stress is ubiquitous in everyday life, but the extent to which acute stress affects how people learn from the outcomes of their choices is still poorly understood. Here, we investigate how acute stress impacts reward and punishment learning in men using a reinforcement-learning task. Sixty-two male participants performed the task whilst under stress and control conditions. We observed that acute stress impaired participants' choice performance towards monetary gains, but not losses. To unravel the mechanism(s) underlying such impairment, we fitted a reinforcement-learning model to participants' trial-by-trial choices. Computational modeling indicated that under acute stress participants learned more slowly from positive prediction errors - when the outcomes were better than expected - consistent with stress-induced dopamine disruptions. Such mechanistic understanding of how acute stress impairs reward learning is particularly important given the pervasiveness of stress in our daily life and the impact that stress can have on our wellbeing and mental health.

Impact of the Covid-19 pandemic on perinatal mental health (Riseup-PPD-COVID-19): protocol for an international prospective cohort study.

BACKGROUND: Corona Virus Disease 19 (COVID-19) is a new pandemic, declared a public health emergency by the World Health Organization, which could have negative consequences for pregnant and postpartum women. The scarce evidence published to date suggests that perinatal mental health has deteriorated since the COVID-19 outbreak. However, the few studies published so far have some limitations, such as a cross-sectional design and the omission of important factors for the understanding of perinatal mental health, including governmental restriction measures and healthcare practices implemented at the maternity hospitals. Within the Riseup-PPD COST Action, a study is underway to assess the impact of COVID-19 in perinatal mental health. The primary objectives are to (1) evaluate changes in perinatal mental health outcomes; and (2) determine the risk and protective factors for perinatal mental health during the COVID-19 pandemic. Additionally, we will compare the results between the countries participating in the study. METHODS: This is an international prospective cohort study, with a baseline and three follow-up assessments over a six-month period. It is being carried out in 11 European countries (Albania, Bulgaria, Cyprus, France, Greece, Israel, Malta, Portugal, Spain, Turkey, and the United Kingdom), Argentina, Brazil and Chile. The sample consists of adult pregnant and postpartum women (with infants up to 6 months of age). The assessment includes measures on COVID-19 epidemiology and public health measures (Oxford COVID-19 Government Response Tracker dataset), Coronavirus Perinatal Experiences (COPE questionnaires), psychological distress (BSI-18), depression (EPDS), anxiety (GAD-7) and post-traumatic stress symptoms (PTSD checklist for DSM-V). DISCUSSION: This study will provide important information for understanding the impact of the COVID-19 pandemic on perinatal mental health and well-being, including the identification of potential risk and protective factors by implementing predictive models using machine learning techniques. The findings will help policymakers develop suitable guidelines and prevention strategies for perinatal mental health and contribute to designing tailored mental health interventions. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04595123 .

Mothers' distress exposure and children's withdrawn behavior - A moderating role for the Interferon Gamma gene (IFNG).

The dysregulation of the inflammatory response, including pro-inflammatory molecules, produces neuropsychiatric symptoms and depression-like behavior, including withdrawal from the physical and social environment. Genetic variants that enhance immune reactivity may thus increase inflammatory and withdrawn reactions to stress. Here we investigated a functional polymorphism of Interferon Gamma gene (IFNG +874 T > A, rs2430561) as moderator of the relationship between mothers' distress exposure and children's withdrawn behavior at preschool age. Participants were 198 Portuguese preschool children (mean age = 57.98 months). Exposure to mother's distress was assessed using the Brief Symptom Inventory, and withdrawn behavior with the Caregiver Teacher Report Form. All children provided saliva samples for genotyping. Contrary to expecations based on prior work, the rs2430561 AA genotype-not the T variant-interacted with (high levels of) mothers' distress exposure, to increase children's withdrawn behavior. No significant main effects were detected. The polymorphism in Interferon Gamma gene showed specific environmental stressor-dependent effects on withdrawn behavior during childhood, ones which are interpreted in light of the "behavioral immune system" hypothesis, and which proved inconsistent with diathesis-stress thinking.

Passive ultrasonic irrigation in root canal: systematic review and meta-analysis.

OBJECTIVE: To investigate whether there are differences between the root canal disinfection, comparing the passive ultrasonic irrigation technique with the conventional technique. MATERIALS AND METHODS: The following electronic databases were searched: Pubmed; VHL; Web of Sciences and OVID with no publication date restriction. The study's quality evaluation was carried out using the Handbook by Cochrane. The online research identified 5464 studies. From the nine studies selected for a full reading of the text, five were included in the present systematic review. Meta-analysis was performed in three articles, which evaluated the root canal's cleanness through microbiological analysis. RESULTS: Only one article concluded that the ultrasonic passive irrigation showed a better performance compared with the conventional irrigation. None of the articles analyzed presented a low risk of bias in all domains. According to the results of the meta-analysis, there was no statistical difference between the groups (OR = 0.34, IC 95%: 0.10-1.19). CONCLUSIONS: The level of evidence comparing the two techniques is fragile since in all studies some type of bias was observed which may interfere in the results and conclusions.

Development and validation of an observational measure of symptoms of Reactive Attachment Disorder.

Reactive Attachment Disorder (RAD) is presumed to be a consequence of social neglect and deprivation of the kind particularly associated with institutional care. Despite its clinical relevance there is a lack of assessment tools for RAD based on the direct observation of child-caregiver interaction. Here we describe the development and validation of such a tool for use with preschool children, the Rating of Inhibited Attachment Disordered Behavior (RInAB). The RInAB is composed of 17 ratings grouped in three subscales assessing (1) Attachment, (2) Exploratory, and (3) Socioemotional behavior. Participants were 134 institutionalized preschool children (M = 54.84 months; SD = 10.83; 60% boys) and their caregivers. Adequate reliability was found for RInAB subscales and total score. Confirmatory factor analyses documented the three aforementioned RInAB subscales. Correlational analyses documented: (i) construct validity via positive and significant associations with caregiver sensitivity and quality of child-caregiver relationship; (ii) convergence validity via association evidence with some emotionally/withdrawn inhibited items of the Disturbed Attachment Interview (DAI), as well as, with Child Behavior Checklist (CBCL)'s somatic complaints and withdraw syndrome scales; and (iii) discriminant validity via nonsignificant or negative associations with DAI-indiscriminate subscale, Rating of Infant and Stranger Engagement (RISE) and CBCL-externalizing problems. Discussion highlights the contributions complementary roles of RInAB for a comprehensive assessment of child RAD-related functioning.

[Deep Venous Thrombosis as the First Manifestation of Hibernoma - Clinical Case]. / Trombose Venosa Profunda como Primeira Manifestação de Hibernoma - Caso Clínico.

We present a 36 year-old female patient with a popliteo-femoral deep vein thrombosis whose further workup revealed a thigh tumor later diagnosed as hibernoma. Hibernoma is a very rare benign tumor stemming from vestigial remnants of fetal brown adipose cells, usually disclosed as a slow and painless growing, mass. It is impossible to distinguish it on clinical grounds from the more aggressive and ominous liposarcoma.

Mulher de 36 anos referenciada à consulta de Cirurgia Vascular por trombose venosa profunda poplíteo-femoral a quem, no seguimento do estudo, foi detetada uma neoplasia da coxa depois diagnosticada como sendo um hibernoma. O hibernoma é um tumor muito raro, benigno, com origem em tecido embrionário remanescente adiposo castanho, com um crescimento lento e indolor.¹ As suas características tornam-no impossível de diferenciar de outra entidade mais agressiva denominada lipossarcoma.².

Genome-wide association mapping of resistance to a Brazilian isolate of Sclerotinia sclerotiorum in soybean genotypes mostly from Brazil.

BACKGROUND: Sclerotinia Stem Rot (SSR), caused by the fungal pathogen Sclerotinia sclerotiorum, is ubiquitous in cooler climates where soybean crops are grown. Breeding for resistance to SSR remains challenging in crops like soybean, where no single gene provides strong resistance, but instead, multiple genes work together to provide partial resistance. In this study, a genome-wide association study (GWAS) was performed to dissect the complex genetic architecture of soybean quantitative resistance to SSR and to provide effective molecular markers that could be used in breeding programs. A collection of 420 soybean genotypes were selected based on either reports of resistance, or from one of three different breeding programs in Brazil, two commercial, one public. Plant genotype sensitivity to SSR was evaluated by the cut stem inoculation method, and lesion lengths were measured at 4 days post inoculation. RESULTS: Genotyping-by-sequencing was conducted to genotype the 420 soybean lines. The TASSEL 5 GBSv2 pipeline was used to call SNPs under optimized parameters, and with the extra step of trimming adapter sequences. After filtering missing data, heterozygosity, and minor allele frequency, a total of 11,811 SNPs and 275 soybean genotypes were obtained for association analyses. Using a threshold of FDR-adjusted p-values <0.1, the Compressed Mixed Linear Model (CMLM) with Genome Association and Prediction Integrated Tool (GAPIT), and the Fixed and Random Model Circulating Probability Unification (FarmCPU) methods, both approaches identified SNPs with significant association to disease response on chromosomes 1, 11, and 18. The CMLM also found significance on chromosome 19, whereas FarmCPU also identified significance on chromosomes 4, 9, and 16. CONCLUSIONS: These similar and yet different results show that the computational methods used can impact SNP associations in soybean, a plant with a high degree of linkage disequilibrium, and in SSR resistance, a trait that has a complex genetic basis. A total of 125 genes were located within linkage disequilibrium of the three loci shared between the two models. Their annotations and gene expressions in previous studies of soybean infected with S. sclerotiorum were examined to narrow down the candidates.

Acquisition of anoikis resistance promotes alterations in the Ras/ERK and PI3K/Akt signaling pathways and matrix remodeling in endothelial cells.

Anoikis is a programmed cell death induced upon cell detachment from extracellular matrix. Anoikis resistance is a critical mechanism in tumor metastasis. Cancer cells deregulate and adapt their metabolism to survive in the absence of adhesion, spreading metastases to distant organs. These adaptations include abnormal regulation of growth factor receptors activating prosurvival signaling pathways, such as the Ras/ERK and PI3K/Akt pathways, and extracellular matrix remodeling, leading to metastasis by an increase of invasiveness and inhibiting anoikis. This study investigates the possible involvement of ECM components and signaling pathways in the regulation of resistance to anoikis in endothelial cells (EC). Endothelial cells submitted to stressful conditions by blocking adhesion to substrate (anoikis resistance) display an up-regulation of Ras/ERK and PI3k/Akt pathways by high expression of Ras, ERK, PI3K (p110α) and Akt (Thr 308). After ERK and PI3K inhibiting, all EC-derived cell lines studied showed lower growth, a decrease in invasive potential and a higher rate of apoptosis. Furthermore, anoikis-resistant cell lines display a decrease in the expression of fibronectin, collagen IV and hyaluronic acid and an increase in the expression of laminin, perlecan, αv, ß3, α5 and ß1 integrins subunits, hyaluronidades 1, 2 and 3 and metalloproteinases 2 and 9. These results indicate that the acquisition of anoikis resistance induced remodeling of the extracellular matrix and overexpression of the PI3K/Akt and Ras/ERK pathway components. Acquisition of resistance to anoikis is a potentially crucial step in endothelial cell transformation.