Epithelial-mesenchymal transition in tissue repair and degeneration.

Epithelial-mesenchymal transitions (EMTs) are the epitome of cell plasticity in embryonic development and cancer; during EMT, epithelial cells undergo dramatic phenotypic changes and become able to migrate to form different tissues or give rise to metastases, respectively. The importance of EMTs in other contexts, such as tissue repair and fibrosis in the adult, has become increasingly recognized and studied. In this Review, we discuss the function of EMT in the adult after tissue damage and compare features of embryonic and adult EMT. Whereas sustained EMT leads to adult tissue degeneration, fibrosis and organ failure, its transient activation, which confers phenotypic and functional plasticity on somatic cells, promotes tissue repair after damage. Understanding the mechanisms and temporal regulation of different EMTs provides insight into how some tissues heal and has the potential to open new therapeutic avenues to promote repair or regeneration of tissue damage that is currently irreversible. We also discuss therapeutic strategies that modulate EMT that hold clinical promise in ameliorating fibrosis, and how precise EMT activation could be harnessed to enhance tissue repair.

Guidelines and definitions for research on epithelial-mesenchymal transition.

Epithelial-mesenchymal transition (EMT) encompasses dynamic changes in cellular organization from epithelial to mesenchymal phenotypes, which leads to functional changes in cell migration and invasion. EMT occurs in a diverse range of physiological and pathological conditions and is driven by a conserved set of inducing signals, transcriptional regulators and downstream effectors. With over 5,700 publications indexed by Web of Science in 2019 alone, research on EMT is expanding rapidly. This growing interest warrants the need for a consensus among researchers when referring to and undertaking research on EMT. This Consensus Statement, mediated by 'the EMT International Association' (TEMTIA), is the outcome of a 2-year-long discussion among EMT researchers and aims to both clarify the nomenclature and provide definitions and guidelines for EMT research in future publications. We trust that these guidelines will help to reduce misunderstanding and misinterpretation of research data generated in various experimental models and to promote cross-disciplinary collaboration to identify and address key open questions in this research field. While recognizing the importance of maintaining diversity in experimental approaches and conceptual frameworks, we emphasize that lasting contributions of EMT research to increasing our understanding of developmental processes and combatting cancer and other diseases depend on the adoption of a unified terminology to describe EMT.

EMT: 2016.

The significant parallels between cell plasticity during embryonic development and carcinoma progression have helped us understand the importance of the epithelial-mesenchymal transition (EMT) in human disease. Our expanding knowledge of EMT has led to a clarification of the EMT program as a set of multiple and dynamic transitional states between the epithelial and mesenchymal phenotypes, as opposed to a process involving a single binary decision. EMT and its intermediate states have recently been identified as crucial drivers of organ fibrosis and tumor progression, although there is some need for caution when interpreting its contribution to metastatic colonization. Here, we discuss the current state-of-the-art and latest findings regarding the concept of cellular plasticity and heterogeneity in EMT. We raise some of the questions pending and identify the challenges faced in this fast-moving field.

The ins and outs of the epithelial to mesenchymal transition in health and disease.

The epithelial to mesenchymal transition (EMT) converts epithelial cells into migratory and invasive cells and is a fundamental event in morphogenesis. Although its relevance in the progression of cancer and organ fibrosis had been debated until recently, the EMT is now established as an important step in the metastatic cascade of epithelial tumors. The similarities between pathological and developmental EMTs validate the embryo as the best model to understand the molecular and cellular mechanisms involved in this process, identifying those that are hijacked during the progression of cancer and organ degeneration. Our ever-increasing understanding of how transcription factors regulate the EMT has revealed complex regulatory loops coupled to posttranscriptional and epigenetic regulatory programs. The EMT is now integrated into the systemic activities of whole organisms, establishing links with cell survival, stemness, inflammation, and immunity. In addition, the EMT now constitutes a promising target for the treatment of cancer and organ-degenerative diseases.

Epithelial-mesenchymal transitions in development and disease.

The epithelial to mesenchymal transition (EMT) plays crucial roles in the formation of the body plan and in the differentiation of multiple tissues and organs. EMT also contributes to tissue repair, but it can adversely cause organ fibrosis and promote carcinoma progression through a variety of mechanisms. EMT endows cells with migratory and invasive properties, induces stem cell properties, prevents apoptosis and senescence, and contributes to immunosuppression. Thus, the mesenchymal state is associated with the capacity of cells to migrate to distant organs and maintain stemness, allowing their subsequent differentiation into multiple cell types during development and the initiation of metastasis.

Epidemiological, Clinical, and Allergic Profile of Psoriatic Patients. Evaluation of the Spanish Registry of Contact Dermatitis and Cutaneous Allergy (REIDAC). / Perfil epidemiológico, clínico y alérgico en pacientes con psoriasis. Evaluación del Registro Español de Dermatitis de Contacto (REIDAC).

BACKGROUND: Psoriasis is a chronic inflammatory dermatosis whose clinical and topographic distribution requires differential diagnosis, or the possible association with allergic contact dermatitis (ACD), requiring patch testing (PT) as part of the diagnostic procedure. OBJECTIVES: To describe the epidemiological, clinical, and allergic profile of patients with a primary or secondary diagnosis of psoriasis undergoing PT and compare them with patients with a diagnosis of ACD at the end of the diagnostic process. METHODS: Cross-sectional study with data from REIDAC from 2018 through 2023 of selected patients with a diagnosis of psoriasis and/or ACD. RESULTS: A total of 11 502 patients were included, 513 of whom had been diagnosed with primary or secondary psoriasis, 3640 with ACD, and 108 with both diseases. Men were more predominant in the groups of patients with psoriasis, psoriasis+ACD, and lesions were more predominantly seen in the hands with little association with atopic factors vs the ACD group. The rate of positivity in PT to the 2022 Spanish battery of allergens was lower in the group with psoriasis only in 27% of the patients. The most common allergens found in the psoriasis group were also the most common ones found in the overall ACD population. CONCLUSIONS: Overall, 36.2% of psoriatic patients tested positive in PT to the 2022 Spanish battery of allergens, which proved that this association is not uncommon. Overall, psoriatic patients had a higher mean age, were more predominantly men, and showed more hand involvement.

Standard and Expanded Series Patch Testing Update by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC). / Actualización de la batería estándar y batería ampliada de pruebas alérgicas de contacto por el Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea (GEIDAC).

After the meeting held by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) back in October 2021, changes were suggested to the Spanish standard series patch testing. Hydroxyethyl methacrylate (2% pet.), textile dye mixt (6.6% pet.), linalool hydroperoxide (1% pet.), and limonene hydroperoxide (0.3% pet.) were, then, added to the series that agreed upon in 2016. Ethyldiamine and phenoxyethanol were excluded. Methyldibromoglutaronitrile, the mixture of sesquiterpene lactones, and hydroxyisohexyl 3-cyclohexene (Lyral) were alo added to the extended Spanish series of 2022.

Genetic and activity dependent-mechanisms wiring the cortex: Two sides of the same coin.

The cerebral cortex is responsible for the higher-order functions of the brain such as planning, cognition, or social behaviour. It provides us with the capacity to interact with and transform our world. The substrates of cortical functions are complex neural circuits that arise during development from the dynamic remodelling and progressive specialization of immature undefined networks. Here, we review the genetic and activity-dependent mechanisms of cortical wiring focussing on the importance of their interaction. Cortical circuits emerge from an initial set of neuronal types that engage in sequential forms of embryonic and postnatal activity. Such activities further complement the cells' genetic programs, increasing neuronal diversity and modifying the electrical properties while promoting selective connectivity. After a temporal window of enhanced plasticity, the main features of mature circuits are established. Failures in these processes can lead to neurodevelopmental disorders whose treatment remains elusive. However, a deeper dissection of cortical wiring will pave the way for innovative therapies.

A right-handed signalling pathway drives heart looping in vertebrates.

Most animals show external bilateral symmetry, which hinders the observation of multiple internal left-right (L/R) asymmetries that are fundamental to organ packaging and function. In vertebrates, left identity is mediated by the left-specific Nodal-Pitx2 axis that is repressed on the right-hand side by the epithelial-mesenchymal transition (EMT) inducer Snail1 (refs 3, 4). Despite some existing evidence, it remains unclear whether an equivalent instructive pathway provides right-hand-specific information to the embryo. Here we show that, in zebrafish, BMP mediates the L/R asymmetric activation of another EMT inducer, Prrx1a, in the lateral plate mesoderm with higher levels on the right. Prrx1a drives L/R differential cell movements towards the midline, leading to a leftward displacement of the cardiac posterior pole through an actomyosin-dependent mechanism. Downregulation of Prrx1a prevents heart looping and leads to mesocardia. Two parallel and mutually repressed pathways, respectively driven by Nodal and BMP on the left and right lateral plate mesoderm, converge on the asymmetric activation of the transcription factors Pitx2 and Prrx1, which integrate left and right information to govern heart morphogenesis. This mechanism is conserved in the chicken embryo, and in the mouse SNAIL1 acts in a similar manner to Prrx1a in zebrafish and PRRX1 in the chick. Thus, a differential L/R EMT produces asymmetric cell movements and forces, more prominent from the right, that drive heart laterality in vertebrates.

Transition of Adolescents With Severe Asthma From Pediatric to Adult Care in Spain: The STAR Consensus.

OBJECTIVES: To assess the degree of consensus among a multidisciplinary expert panel on the transition of adolescents with severe asthma from pediatric to adult care. METHODS: A 61-item survey was developed based on guidelines for other chronic diseases, covering transition planning, preparation, effective transfer, and follow-up. A 2-round Delphi process assessed the degree of consensus among 98 experts (49 pediatricians, 24 allergists, and 25 pulmonologists). Consensus was established with ≥70% agreement. RESULTS: Consensus was reached for 42 items (70%). Panelists were unable to agree on an age range for initiation of transition. The main goal during the transition identified by the experts is for adolescents to gain autonomy in managing severe asthma and prescribed treatments. The panelists agreed on the importance of developing an individualized plan, promoting patient autonomy, and identifying factors associated with the home environment. They agreed that the adult health care team should have expertise in severe asthma, biologics, and management of adolescent patients. Pediatric and adult health care teams should share clinical information, agree on the criteria for maintaining biological therapy, and have an on-site joint visit with the patient before the effective transfer. Adult health care professionals should closely follow the patient after the effective transfer to ensure correct inhaler technique, adherence, and attendance at health care appointments. CONCLUSION: This consensus document provides the first roadmap for Spanish pediatric and adult teams to ensure that key aspects of the transition process in severe asthma are covered. The implementation of these recommendations will improve the quality of care offered to the patient.

A differential therapeutic consideration for use of corticosteroids according to established COVID-19 clinical phenotypes in critically ill patients.

Objective: To determine if the use of corticosteroids was associated with Intensive Care Unit (ICU) mortality among whole population and pre-specified clinical phenotypes. Design: A secondary analysis derived from multicenter, observational study. Setting: Critical Care Units. Patients: Adult critically ill patients with confirmed COVID-19 disease admitted to 63 ICUs in Spain. Interventions: Corticosteroids vs. no corticosteroids. Main variables of interest: Three phenotypes were derived by non-supervised clustering analysis from whole population and classified as (A: severe, B: critical and C: life-threatening). We performed a multivariate analysis after propensity optimal full matching (PS) for whole population and weighted Cox regression (HR) and Fine-Gray analysis (sHR) to assess the impact of corticosteroids on ICU mortality according to the whole population and distinctive patient clinical phenotypes. Results: A total of 2017 patients were analyzed, 1171 (58%) with corticosteroids. After PS, corticosteroids were shown not to be associated with ICU mortality (OR: 1.0; 95% CI: 0.98-1.15). Corticosteroids were administered in 298/537 (55.5%) patients of "A" phenotype and their use was not associated with ICU mortality (HR = 0.85 [0.55-1.33]). A total of 338/623 (54.2%) patients in "B" phenotype received corticosteroids. No effect of corticosteroids on ICU mortality was observed when HR was performed (0.72 [0.49-1.05]). Finally, 535/857 (62.4%) patients in "C" phenotype received corticosteroids. In this phenotype HR (0.75 [0.58-0.98]) and sHR (0.79 [0.63-0.98]) suggest a protective effect of corticosteroids on ICU mortality. Conclusion: Our finding warns against the widespread use of corticosteroids in all critically ill patients with COVID-19 at moderate dose. Only patients with the highest inflammatory levels could benefit from steroid treatment.

Objetivo: Evaluar si el uso de corticoesteroides (CC) se asocia con la mortalidad en la unidad de cuidados intensivos (UCI) en la población global y dentro de los fenotipos clínicos predeterminados. Diseño: Análisis secundario de estudio multicéntrico observacional. Ámbito: UCI. Pacientes: Pacientes adultos con COVID-19 confirmado ingresados en 63 UCI de España. Intervención: Corticoides vs. no corticoides. Variables de interés principales: A partir del análisis no supervisado de grupos, 3 fenotipos clínicos fueron derivados y clasificados como: A grave, B crítico y C potencialmente mortal. Se efectuó un análisis multivariado después de un propensity optimal full matching (PS) y una regresión ponderada de Cox (HR) y análisis de Fine-Gray (sHR) para evaluar el impacto del tratamiento con CC sobre la mortalidad en la población general y en cada fenotipo clínico. Resultados: Un total de 2.017 pacientes fueron analizados, 1.171 (58%) con CC. Después del PS, el uso de CC no se relacionó significativamente con la mortalidad en UCI (OR: 1,0; IC 95%: 0,98-1,15). Los CC fueron administrados en 298/537 (55,5%) pacientes del fenotipo A y no se observó asociación significativa con la mortalidad (HR = 0,85; 0,55-1,33). Un total de 338/623 (54,2%) pacientes del fenotipo B recibieron CC sin efecto significativo sobre la mortalidad (HR = 0,72; 0,49-1,05). Por último, 535/857 (62,4%) pacientes del fenotipo C recibieron CC. En este fenotipo, se evidenció un efecto protector de los CC sobre la mortalidad HR (0,75; 0,58-0,98). Conclusión: Nuestros hallazgos alertan sobre el uso indiscriminado de CC a dosis moderadas en todos los pacientes críticos con COVID-19. Solamente pacientes con elevado estado de inflamación podrían beneficiarse con el tratamiento con CC.

Acquired vibratory angioedema with a severe impact on work performance.

Vibratory urticaria/angioedema is an inducible type of urticaria that may be elicited by vibratory stimuli from work tool and instruments. A 39-year-old male construction worker was diagnosed with acquired vibratory angioedema associated with chronic spontaneous urticaria involving a severe work performance impairment. Response to omalizumab was immediate and complete. We evaluated the Urticarial Activity Score; the response to the vibratory angioedema provocation vortex test; and evolution of analytical parameters (e.g. high-affinity IgE receptor expression on peripheral blood basophils, C-reactive protein, D-dimer and IgE levels). Vibratory angioedema may be misdiagnosed as delayed pressure urticaria if the appropriate specific provocation tests are not performed. According to our knowledge, this is the first time a pneumatic hammer is described as a trigger; the first case responding to omalizumab; and the second published case associated with spontaneous chronic urticaria.

Epidemiological, Clinical, and Allergy Profile of Patients With Atopic Dermatitis and Hand Eczema: Evaluation of the Spanish Contact Dermatitis Registry (REIDAC). / Perfil epidemiológico, clínico, y alérgico en pacientes con dermatitis atópica y dermatitis de las manos. Evaluación del Registro Español de Dermatitis de Contacto (REIDAC).

BACKGROUND: Hand eczema is common in patients with atopic dermatitis (AD), but few studies have described the characteristics of these patients in large, representative populations from different geographic regions and occupational settings. OBJECTIVE: To describe the epidemiological, clinical, and allergy profile of patients with hand eczema who underwent patch testing and compare patients with and without AD. METHODS: Analysis of data from the Spanish Contact Dermatitis Registry, a multicenter registry of patients who undergo patch testing in Spain. RESULTS: We included 1466 patients with hand eczema who were patch tested between January 2018 and June 2020. Those with AD were younger and had had symptoms for longer before testing. They were also more likely to have been exposed to occupational triggers (38% vs 53% for patients without AD). The only profession for which significant differences were found was hairdressing. The most common allergens were nickel sulfate, methylchloroisothiazolinone/methylisothiazolinone, cobalt chloride, potassium dichromate, fragrance mixes I and II, and formaldehyde. The most common diagnoses were allergic contact dermatitis (24% vs 31% in patients with and without AD, P=.0224) and irritant contact dermatitis (18% and 35% respectively, P<.001). CONCLUSIONS: AD is common in patients with predominant hand eczema who undergo patch testing. Patients with hand eczema and AD have different clinical and epidemiological characteristics to hand eczema patients in general and their final diagnosis following patch testing is also different.

The Evolutionary History of Ephs and Ephrins: Toward Multicellular Organisms.

Eph receptor (Eph) and ephrin signaling regulate fundamental developmental processes through both forward and reverse signaling triggered upon cell-cell contact. In vertebrates, they are both classified into classes A and B, and some representatives have been identified in many metazoan groups, where their expression and functions have been well studied. We have extended previous phylogenetic analyses and examined the presence of Eph and ephrins in the tree of life to determine their origin and evolution. We have found that 1) premetazoan choanoflagellates may already have rudimental Eph/ephrin signaling as they have an Eph-/ephrin-like pair and homologs of downstream-signaling genes; 2) both forward- and reverse-downstream signaling might already occur in Porifera since sponges have most genes involved in these types of signaling; 3) the nonvertebrate metazoan Eph is a type-B receptor that can bind ephrins regardless of their membrane-anchoring structure, glycosylphosphatidylinositol, or transmembrane; 4) Eph/ephrin cross-class binding is specific to Gnathostomata; and 5) kinase-dead Eph receptors can be traced back to Gnathostomata. We conclude that Eph/ephrin signaling is of older origin than previously believed. We also examined the presence of protein domains associated with functional characteristics and the appearance and conservation of downstream-signaling pathways to understand the original and derived functions of Ephs and ephrins. We find that the evolutionary history of these gene families points to an ancestral function in cell-cell interactions that could contribute to the emergence of multicellularity and, in particular, to the required segregation of cell populations.

Exploring different profiles of gender (non)conformity in women and their relationship with sexual orientation and mental health.

We examined whether sexual orientation and the Conformity to Feminine Norms (CFN) were predictors of three mental health outcomes: depression, anxiety, and self-esteem. The sample comprised 690 women with different sexual orientations (heterosexual, lesbian and bisexual). Our results suggested that there were five CFN profiles related to sexual orientation, but only the former was a significant predictor of the three mental health outcomes and that women might experience different forms of CFN which in turn can differentially influence women's mental health.

G-protein-coupled receptor kinase 2 safeguards epithelial phenotype in head and neck squamous cell carcinomas.

Head and neck squamous cell carcinoma (HNSCC) arises from the mucosal lining of the upper aerodigestive tract and display few treatment options in advanced stages. Despite increased knowledge of HNSCC molecular biology, the identification of new players involved in triggering HNSCC recurrence and metastatic disease is needed. We uncover that G-protein-coupled receptor kinase-2 (GRK2) expression is reduced in undifferentiated, high-grade human HNSCC tumors, whereas its silencing in model human HNSCC cells is sufficient to trigger epithelial-to-mesenchymal transition (EMT) phenotypic features, an EMT-like transcriptional program and enhanced lymph node colonization from orthotopic tongue tumors in mice. Conversely, enhancing GRK2 expression counteracts mesenchymal cells traits by mechanisms involving phosphorylation and decreased functionality of the key EMT inducer Snail1. Our results suggest that GRK2 safeguards the epithelial phenotype, whereas its downregulation contributes to the activation of EMT programs in HNSCC.

Snail2 and Zeb2 repress P-cadherin to define embryonic territories in the chick embryo.

Snail and Zeb transcription factors induce epithelial-to-mesenchymal transition (EMT) in embryonic and adult tissues by direct repression of E-cadherin transcription. The repression of E-cadherin transcription by the EMT inducers Snail1 and Zeb2 plays a fundamental role in defining embryonic territories in the mouse, as E-cadherin needs to be downregulated in the primitive streak and in the epiblast, concomitant with the formation of mesendodermal precursors and the neural plate, respectively. Here, we show that in the chick embryo, E-cadherin is weakly expressed in the epiblast at pre-primitive streak stages where it is substituted for by P-cadherin We also show that Snail2 and Zeb2 repress P-cadherin transcription in the primitive streak and the neural plate, respectively. This indicates that E- and P-cadherin expression patterns evolved differently between chick and mouse. As such, the Snail1/E-cadherin axis described in the early mouse embryo corresponds to Snail2/P-cadherin in the chick, but both Snail factors and Zeb2 fulfil a similar role in chick and mouse in directly repressing ectodermal cadherin genes to contribute to the delamination of mesendodermal precursors at gastrulation and the proper specification of the neural ectoderm during neural induction.