Mechanical Forces as Determinants of Disseminated Metastatic Cell Fate

Disseminated metastatic cancer cells represent one of the most relevant causes of disease relapse and associated death for cancer patients, and a therapeutic target of the highest priority. Still, our understanding of how disseminated cancer cells survive in the foreign metastatic environment, and eventually cause metastatic outgrowth, remains rather limited. In this review we focus on the cell microenvironment as a key regulator of cell behavior at the metastatic site, and especially on the mechanical properties of the extracellular matrix and associated integrin signaling. We discuss available evidence pointing to a pervasive role of extracellular matrix (ECM) mechanical properties in regulating cancer cell proliferation and survival after dissemination, and propose that this might represent an important bottleneck for cells invading and establishing into a novel tissue. We point to the known molecular players, how these might contribute to modulate the mechanical properties of the metastatic environment, and the response of cells to these cues. Finally, we propose that emerging knowledge on the physical interaction of disseminated metastatic cells and on the downstream mechanotransduction pathways, including YAP/TAZ (Yes-associated protein-1 and WW-domain transcription activator 1) and MRTFs (Myocardin-related transcription factors), may help to identify novel approaches for therapy

A inserção da regulamentação da profissão na área de educação física, dez anos depois: embates, debates e perspectivas

This text argues some questions controversies on the regulation of the profession. Our interest is to give a theoretical basement of a side, and to hear the citizens directly related on these controversies of another one. For this we first decide to clarify the initial aspects of the regulation of the professions, stops later making an analysis of the law and resolutions of the Advice presenting: (a) the meaning; (b) attributions and abilities; (c) the limit for the fiscalization and of the power of polices and (d) to point the typical activities of the professional. Concluded this part we will raise an controversial subject that appeared in these last five years: the subordination of the dance, yoga, martial arts to the Federal Advice of Physical Education.Este texto discute las controversias sobre la regulación de la profesión. Nuestro interés es dar un suporte teórico de un lado, y oír a los ciudadanos relacionados directamente en estas controversias de otro. Para esto primero decidimos clarificar los aspectos iniciales de la regulación de las profesiones, un análisis de la ley y de las resoluciones del consejo: (a) el significado; (b) atribuciones y capacidades; (c) el límite para el fiscalización y de la energía del limpia y (d) para señalar las actividades típicas del profesional. Después del esta parte levantaremos un tema polémico: la subordinación de la danza, yoga, artes marciales al consejo federal de la educación física.Este texto discute alguns aspectos da regulamentação da profissão na área da Educação Física, seu desenvolvimento e a participação dos principais sujeitos políticos. Frente a um tema atual e polêmico, procuramos fazer uma apresentação objetiva e abrangente do seu desenvolvimento e ilustrar as posições e argumentos dos sujeitos que participam do debate. Para tanto, iniciamos apresentando aspectos importantes da regulamentação das profissões, para depois elaborar uma análise da lei e resoluções do Conselho destacando: (a) o seu significado; (b) atribuições e competências; (c) o limite para a fiscalização e do poder de policia e (d) apontar as atividades típicas do profissional. A título de fechamento, descrevemos aspectos de uma polêmica bastante recente, a subordinação da dança, yoga, artes marciais ao Conselho Federal de Educação Física

New features of desiccation tolerance in the lichen photobiont Trebouxia gelatinosa are revealed by a transcriptomic approach.

Trebouxia is the most common lichen-forming genus of aero-terrestrial green algae and all its species are desiccation tolerant (DT). The molecular bases of this remarkable adaptation are, however, still largely unknown. We applied a transcriptomic approach to a common member of the genus, T. gelatinosa, to investigate the alteration of gene expression occurring after dehydration and subsequent rehydration in comparison to cells kept constantly hydrated. We sequenced, de novo assembled and annotated the transcriptome of axenically cultured T. gelatinosa by using Illumina sequencing technology. We tracked the expression profiles of over 13,000 protein-coding transcripts. During the dehydration/rehydration cycle c. 92 % of the total protein-coding transcripts displayed a stable expression, suggesting that the desiccation tolerance of T. gelatinosa mostly relies on constitutive mechanisms. Dehydration and rehydration affected mainly the gene expression for components of the photosynthetic apparatus, the ROS-scavenging system, Heat Shock Proteins, aquaporins, expansins, and desiccation related proteins (DRPs), which are highly diversified in T. gelatinosa, whereas Late Embryogenesis Abundant Proteins were not affected. Only some of these phenomena were previously observed in other DT green algae, bryophytes and resurrection plants, other traits being distinctive of T. gelatinosa, and perhaps related to its symbiotic lifestyle. Finally, the phylogenetic inference extended to DRPs of other chlorophytes, embryophytes and bacteria clearly pointed out that DRPs of chlorophytes are not orthologous to those of embryophytes: some of them were likely acquired through horizontal gene transfer from extremophile bacteria which live in symbiosis within the lichen thallus

Actomyosin drives cancer cell nuclear dysmorphia and threatens genome stability

Altered nuclear shape is a defining feature of cancer cells. The mechanisms underlying nuclear dysmorphia in cancer remain poorly understood. Here we identify PPP1R12A and PPP1CB, two subunits of the myosin phosphatase complex that antagonizes actomyosin contractility, as proteins safeguarding nuclear integrity. Loss of PPP1R12A or PPP1CB causes nuclear fragmentation, nuclear envelope rupture, nuclear compartment breakdown and genome instability. Pharmacological or genetic inhibition of actomyosin contractility restores nuclear architecture and genome integrity in cells lacking PPP1R12A or PPP1CB. We detect actin filaments at nuclear envelope rupture sites and define the Rho-ROCK pathway as the driver of nuclear damage. Lamin A protects nuclei from the impact of actomyosin activity. Blocking contractility increases nuclear circularity in cultured cancer cells and suppresses deformations of xenograft nuclei in vivo. We conclude that actomyosin contractility is a major determinant of nuclear shape and that unrestrained contractility causes nuclear dysmorphia, nuclear envelope rupture and genome instability

Ten years-snapshot of the occurrence of emerging contaminants in drinking, surface and ground waters and wastewaters from São Paulo state, Brazil

Emerging contaminants have been considered one of the main concerns for ensuring the quality of water around the world. This work presents the results of 10 years of analyses carried out in the state of São Paulo (Brazil) that has the high population density and intense agricultural and industrial activities. In this work 58 compounds (9 hormones, 14 pharmaceuticals and personal care products, 8 industrial compounds, 17 pesticides and 10 illicit drugs) were determined from 2006 to 2015 in 708 samples including raw and treated sewage, surface and ground and drinking waters. A preliminary risk assessment for aquatic life protection identified potential risks for caffeine, paracetamol, diclofenac, 17α-ethynylestradiol, 17β-estradiol, estriol, estrone, testosterone, triclosan, 4-n-nonylphenol, bisphenol A, atrazine, azoxystrobin, carbendazim, fipronil, imidacloprid, malathion and tebuconazole. Drinking water criteria were available only for 22 compounds and for them no adverse effects were expected at the concentrations found, except for 17β-estradiol

F-actin dynamics regulates mammalian organ growth and cell fate maintenance.

BACKGROUND & AIMS: In vitro, several data indicate that cell function can be regulated by the mechanical properties of cells and of the microenvironment. Cells measure these features by developing forces via their actomyosin cytoskeleton, and respond accordingly by transducing forces into biochemical signals that instruct cell behavior. Among these, the transcriptional coactivators YAP/TAZ recently emerged as key factors mediating multiple responses to actomyosin contractility. However, whether mechanical cues regulate adult liver tissue homeostasis, and whether this occurs through YAP/TAZ, remains largely unaddressed. METHODS & RESULTS: Here we show that the F-actin capping protein CAPZ is a critical negative regulator of actomyosin contractility and mechanotransduction. Capzb inactivation alters stress fiber and focal adhesion dynamics leading to enhanced myosin activity, increased cellular traction forces, and increased liver stiffness. In vitro, this rescues YAP from inhibition by a small geometry; in vivo, inactivation of Capzb in the adult mouse liver induces YAP activation in parallel to the Hippo pathway, causing extensive hepatocyte proliferation and leading to striking organ overgrowth. Moreover, Capzb is required for the maintenance of the differentiated hepatocyte state, for metabolic zonation, and for gluconeogenesis. In keeping with changes in tissue mechanics, inhibition of the contractility regulator ROCK, or deletion of the Yap1 mechanotransducer, reverse the phenotypes emerging in Capzb-null livers. CONCLUSIONS: These results indicate a previously unrecognized role for CAPZ in tuning the mechanical properties of cells and tissues, which is required in hepatocytes for the maintenance of the differentiated hepatocyte state and to regulate organ size. More in general, it indicates for the first time a physiological role of mechanotransduction in maintaining tissue homeostasis in mammals. LAY SUMMARY: The mechanical properties of cells and tissues (i.e. whether they are soft or stiff) are thought to be important regulators of cell behavior. A recent advancement in our understanding of these phenomena has been the identification of YAP and TAZ as key factors mediating the biological responses of cells to mechanical signals in vitro. However, whether the mechanical properties of cells and/or the mechanical regulation of YAP/TAZ are relevant for mammalian tissue physiology remains unknown. Here we challenge this issue by genetic inactivation of CAPZ, a protein that regulates the cytoskeleton, i.e. the cells' scaffold by which they sense mechanical cues. We found that inactivation of CAPZ alters cells' and liver tissue's mechanical properties, leading to YAP hyperactivation. In turn, this profoundly alters liver physiology, causing organ overgrowth, defects in liver cell differentiation and metabolism. These results reveal a previously uncharacterized role for mechanical signals for the maintenance of adult liver homeostasis.This work was supported by AIRC (Associazione Italiana per la Ricerca sul Cancro) Investigator Grant 15307, WCR (Worldwide Cancer Research) Grant 15-1192, CARIPARO Eccellenza Program 2017 and University of Padua BIRD Grant to SD, AIRC ‘Hard ROCK Café’ Fellowship to GS, Marie Sklodowska-Curie Individual Fellowship (796547) to AG, AIRC Special Program Molecular Clinical Oncology ‘5 per mille’ 10016 to SB, UK Medical Research Council and Sackler Foundation Doctoral Training Grant RG70550 to ACL, UK Medical Research Council Career Development Award G1100312/1 and an Isaac Newton Trust Research Grant 17.24(p) to KF

F-actin dynamics regulates mammalian organ growth and cell fate maintenance.

BACKGROUND & AIMS: In vitro, several data indicate that cell function can be regulated by the mechanical properties of cells and of the microenvironment. Cells measure these features by developing forces via their actomyosin cytoskeleton, and respond accordingly by transducing forces into biochemical signals that instruct cell behavior. Among these, the transcriptional coactivators YAP/TAZ recently emerged as key factors mediating multiple responses to actomyosin contractility. However, whether mechanical cues regulate adult liver tissue homeostasis, and whether this occurs through YAP/TAZ, remains largely unaddressed. METHODS & RESULTS: Here we show that the F-actin capping protein CAPZ is a critical negative regulator of actomyosin contractility and mechanotransduction. Capzb inactivation alters stress fiber and focal adhesion dynamics leading to enhanced myosin activity, increased cellular traction forces, and increased liver stiffness. In vitro, this rescues YAP from inhibition by a small geometry; in vivo, inactivation of Capzb in the adult mouse liver induces YAP activation in parallel to the Hippo pathway, causing extensive hepatocyte proliferation and leading to striking organ overgrowth. Moreover, Capzb is required for the maintenance of the differentiated hepatocyte state, for metabolic zonation, and for gluconeogenesis. In keeping with changes in tissue mechanics, inhibition of the contractility regulator ROCK, or deletion of the Yap1 mechanotransducer, reverse the phenotypes emerging in Capzb-null livers. CONCLUSIONS: These results indicate a previously unrecognized role for CAPZ in tuning the mechanical properties of cells and tissues, which is required in hepatocytes for the maintenance of the differentiated hepatocyte state and to regulate organ size. More in general, it indicates for the first time a physiological role of mechanotransduction in maintaining tissue homeostasis in mammals. LAY SUMMARY: The mechanical properties of cells and tissues (i.e. whether they are soft or stiff) are thought to be important regulators of cell behavior. A recent advancement in our understanding of these phenomena has been the identification of YAP and TAZ as key factors mediating the biological responses of cells to mechanical signals in vitro. However, whether the mechanical properties of cells and/or the mechanical regulation of YAP/TAZ are relevant for mammalian tissue physiology remains unknown. Here we challenge this issue by genetic inactivation of CAPZ, a protein that regulates the cytoskeleton, i.e. the cells' scaffold by which they sense mechanical cues. We found that inactivation of CAPZ alters cells' and liver tissue's mechanical properties, leading to YAP hyperactivation. In turn, this profoundly alters liver physiology, causing organ overgrowth, defects in liver cell differentiation and metabolism. These results reveal a previously uncharacterized role for mechanical signals for the maintenance of adult liver homeostasis.This work was supported by AIRC (Associazione Italiana per la Ricerca sul Cancro) Investigator Grant 15307, WCR (Worldwide Cancer Research) Grant 15-1192, CARIPARO Eccellenza Program 2017 and University of Padua BIRD Grant to SD, AIRC ‘Hard ROCK Café’ Fellowship to GS, Marie Sklodowska-Curie Individual Fellowship (796547) to AG, AIRC Special Program Molecular Clinical Oncology ‘5 per mille’ 10016 to SB, UK Medical Research Council and Sackler Foundation Doctoral Training Grant RG70550 to ACL, UK Medical Research Council Career Development Award G1100312/1 and an Isaac Newton Trust Research Grant 17.24(p) to KF

Hydrogel-in-hydrogel live bioprinting for guidance and control of organoids and organotypic cultures

Three-dimensional hydrogel-based organ-like cultures can be applied to study development, regeneration, and disease in vitro. However, the control of engineered hydrogel composition, mechanical properties and geometrical constraints tends to be restricted to the initial time of fabrication. Modulation of hydrogel characteristics over time and according to culture evolution is often not possible. Here, we overcome these limitations by developing a hydrogel-in-hydrogel live bioprinting approach that enables the dynamic fabrication of instructive hydrogel elements within pre-existing hydrogel-based organ-like cultures. This can be achieved by crosslinking photosensitive hydrogels via two-photon absorption at any time during culture. We show that instructive hydrogels guide neural axon directionality in growing organotypic spinal cords, and that hydrogel geometry and mechanical properties control differential cell migration in developing cancer organoids. Finally, we show that hydrogel constraints promote cell polarity in liver organoids, guide small intestinal organoid morphogenesis and control lung tip bifurcation according to the hydrogel composition and shape

Effective recommendations towards healthy routines to preserve mental health during the COVID-19 pandemic

Objective: To assess the adherence to a set of evidence-based recommendations to support mental health during the coronavirus disease 2019 (COVID-19) pandemic and its association with depressive and anxiety symptoms. Methods: A team of health workers and researchers prepared the recommendations, formatted into three volumes (1: COVID-19 prevention; 2: Healthy habits; 3: Biological clock and sleep). Participants were randomized to receive only Volume 1 (control), Volumes 1 and 2, Volumes 1 and 3, or all volumes. We used a convenience sample of Portuguese-speaking participants over age 18 years. An online survey consisting of sociodemographic and behavioral questionnaires and mental health instruments (Patient Health Questionnaire-9 [PHQ-9] and Generalized Anxiety Disorder-7 [GAD-7]) was administered. At 14 and 28 days later, participants were invited to complete follow-up surveys, which also included questions regarding adherence to the recommendations. A total of 409 participants completed the study – mostly young adult women holding university degrees. Results: The set of recommendations contained in Volumes 2 and 3 was effective in protecting mental health, as suggested by significant associations of adherence with PHQ-9 and GAD-7 scores (reflecting anxiety and depression symptoms, respectively). Conclusion: The recommendations developed in this study could be useful to prevent negative mental health effects in the context of the pandemic and beyond