The pioneer factor Smed-gata456-1 is required for gut cell differentiation and maintenance in planarians

How adult stem cells differentiate into different cell types remains one of the most intriguing questions in regenerative medicine. Pioneer factors are transcription factors that can bind to and open chromatin, and are among the first elements involved in cell differentiation. We used the freshwater planarian Schmidtea mediterranea as a model system to study the role of the gata456 family of pioneer factors in gut cell differentiation during both regeneration and maintenance of the digestive system. Our findings reveal the presence of two members of the gata456 family in the Schmidtea mediterranea genome; Smed-gata456-1 and Smed-gata456-2. Our results show that Smed-gata456-1 is the only ortholog with a gut cell-related function. Smed-gata456-1 is essential for the differentiation of precursors into intestinal cells and for the survival of these differentiated cells, indicating a key role in gut regeneration and maintenance. Furthermore, tissues other than the gut appear normal following Smed-gata456-1 RNA interference (RNAi), indicating a gut-specific function. Importantly, different neoblast subtypes are unaffected by Smed-gata456-1(RNAi), suggesting that 1) Smed-gata456-1 is involved in the differentiation and maintenance, but not in the early determination, of gut cells; and 2) that the stem cell compartment is not dependent on a functional gut

Spinal cord RNA-seq data after a baclofen treatment in mice with a spinal cord injury

Spinal cord injury (SCI) leads to severe functional deficits. Currently, there are no available pharmacological treatments to promote neurological recovery in SCI patients. Recent work from our group has shown that a baclofen treatment can promote functional recovery after a compression SCI in mice [1]. Here, we provide transcriptomic (RNA-seq) data from adult mouse spinal cords collected 7 days after a compression SCI and baclofen (vs vehicle) administration. The Illumina NovaSeq 6000 platform was used to generate the raw transcriptomic data. In addition, we also present bioinformatic analyses including differential gene expression analysis, enrichment analyses for various functional annotations (gene ontology, KEGG and BioCarta pathways or InterPro domains) and transcription factor targets. The raw RNA-seq data has been uploaded to the NCBI Sequence Read Archive (SRA) database (Bioproject ID PRJNA886048). The data generated from the bioinformatic analyses is contained within the articleThis work was supported by the Wings for Life Spinal Cord Research Foundation (grant reference WFL-ES-03/19), the Portuguese Foundation for Science and Technology (FCT) EXPL/MED-FAR/1529/2021 to N. de Sousa and through the Scientific Employment Stimulus to N. Silva and S. Monteiro (CEECIND/04794/2017 and CEECIND/01902/2017) and Grant PID2020-115121GB-I00 funded by MCIN/AEI/10.13039/501100011033 to A. Barreiro-IglesiasS

Microsatellites’ mutation modeling through the analysis of the Y-chromosomal transmission: Results of a GHEP-ISFG collaborative study

The Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) organized a collaborative study on mutations of Y-chromosomal short tandem repeats (Y-STRs). New data from 2225 father-son duos and data from 44 previously published reports, corresponding to 25,729 duos, were collected and analyzed. Marker-specific mutation rates were estimated for 33 Y-STRs. Although highly dependent on the analyzed marker, mutations compatible with the gain or loss of a single repeat were 23.2 times more likely than those involving a greater number of repeats. Longer alleles (relatively to the modal one) showed to be nearly twice more mutable than the shorter ones. Within the subset of longer alleles, the loss of repeats showed to be nearly twice more likely than the gain. Conversely, shorter alleles showed a symmetrical trend, with repeat gains being twofold more frequent than reductions. A positive correlation between the paternal age and the mutation rate was observed, strengthening previous findings. The results of a machine learning approach, via logistic regression analyses, allowed the establishment of algebraic formulas for estimating the probability of mutation depending on paternal age and allele length for DYS389I, DYS393 and DYS627. Algebraic formulas could also be established considering only the allele length as predictor for DYS19, DYS389I, DYS389II-I, DYS390, DYS391, DYS393, DYS437, DYS439, DYS449, DYS456, DYS458, DYS460, DYS481, DYS518, DYS533, DYS576, DYS626 and DYS627 loci. For the remaining Y-STRs, a lack of statistical significance was observed, probably as a consequence of the small effective size of the subsets available, a common difficulty in the modeling of rare events as is the case of mutations. The amount of data used in the different analyses varied widely, depending on how the data were reported in the publications analyzed. This shows a regrettable waste of produced data, due to inadequate communication of the results, supporting an urgent need of publication guidelines for mutation studies.info:eu-repo/semantics/publishedVersio

Role of the Hippo pathway in planarians

[eng] A successful cell renewal, which occurs throughout the life of an organism, relies on multiple events, including proliferation and differentiation of progenitor cell populations, and death of unnecessary cells. Out of the multiple molecular mechanisms involved in the control of cellular renewal, the Hippo signaling pathway currently appears as a hub. Although it was first identified as a key regulator of organ size through the control of cell death and proliferation, growing evidence suggests that it also plays pivotal roles in coordinating stem cell maintenance, cell differentiation, cell-fate decisions and cell survival. To further understand the role of the Hippo pathway in driving adult cellular renewal and, specifically, in promoting cellular sternness, we studied its function in planarians. Due to the presence of a population of pluripotent adult stem cells (neoblasts), planarians have the ability to constantly grow and degrow depending on food availability, and to regenerate any missing body part within a few days. This active and continuous regulation of the stem cell and post-mitotic cell compartments makes planarians an ideal ' in vivo' context to gain an integrated view of the different events underlying homeostatic cell renewal and tissue regeneration. Here, we address whether downregulation of Hippo signaling exerts its sternness­ promoting function by increasing the proliferation of resident stem cells or promoting cell dedifferentiation. We show that inhibition of Smed-hippo (to simplify, hippo) in planarians reduces apoptotic activity and increases mitotic rates. However, this imbalance between cell death and mitotic activity does not lead to an increase in planarian body size or cell number, since hippo (RNAi) does not increase the number of cycling cells but blocks mitotic exit. hippo (RNAi) animals develop overgrowths and extensive regions composed of undifferentiated cells, accompanied by a general decrease in the number of differentiated cells throughout their body. A detailed study of the epidermal lineage reveals that hippo is required to determine the hierarchical transitions required for proper epidermal differentiation, from epidermal-restricted stem cells to differentiated epidermal cells. We also demonstrate that hippo is required to maintain the differentiated state in planarian cells, since hippo inhibition promotes dedifferentiation of post-mitotic cells. Overall, these results in di cate that thE overgrowths and undifferentiated regions observed after hippo inhibition in planarians are not caused by the unbalance between cell death and proliferation but to the inability of cells to reach and maintain the appropriate fate. Furthermore, during this study we demonstrate that the Hippo-Yki signaling cascade is conserved in planarians and plays a role in cell differentiation during planarian regeneration. We further show the conservation of the up-stream regulators of the Hippo pathway in planarians since the inhibition of Hippo up-stream regulators, as lg/- 2, phenocopies the hippo (RNAi) phenotype. Transcriptomic analysis of hippo (RNAi) animals allowed the identification of several putative Hippo pathway targets in planarians, which silencing reproduces the formation of overgrowths. Overall, we propose an essential role for Hippo signaling in restricting cell plasticity and thus in preventing tumoral transformation.[spa] La renovación celular, que tiene lugar durante toda la vida en los organismos adultos, depende de multiples eventos, incluyendo el control de la proliferación, la diferenciación de las celulas progenitoras y la muerte de células innecesarias. La vía de señalización de Hippo ejerce un papel central en el control de todos estos procesos. A pesar de haber sido primeramente identificada como una vía reguladora clave en el control del tamaño de los órganos a través de la regulación de la proliferación y la muerte, evidencias recientes sugieren que esta vía puede estar también involucrada en el mantenimiento de las células madre, en la diferenciación celular, en el mantenimiento del estado diferenciado y en la supervivencia de las células. Para profundizar en el conocimiento del papel de la vía de Hippo durante la renovación celular en tejidos adultos, específicamente en su función reguladora del estado pluripotente de las células, abordamos su estudio en planarias. Debido a la presencia de una población de células pluripotentes adultas, los neoblastos, las planarias poseen la capacidad de crecer y decrecer dependiendo de la disponibilidad de alimento, así como de regenerar cualquier parte de su cuerpo en apenas algunos días. Esta activa y continua regulación de las células madre y de los compartimentos postmitóticos convierte a las planarias en un contexto "in vivo" ideal para obtener una vision integrada de los diferentes mecanismos que controlan la renovación celular durante la homeostasis y la regeneración de los tejidos. En esta tesis hemos abordado la cuestión de si el silenciamiento de la vía de señalización de Hippo afecta a la promoción del estado indiferenciado, concretamente a través del control de la proliferación de células madre o bien promoviendo la desdiferenciación celular. Los resultados obtenidos demuestran que la inhibición de Smed-hippo (para simplificar, hippo) en planarias reduce la actividad apoptótica y aumenta los índices mitóticos. Sin embargo, este desequilibrio entre muerte celular y actividad mitótica no conduce al aumento del tamaño de las planarias ni al aumento del número de células. Uno de los motivos es que la inhibición de hippo no aumenta el numero de células que ciclan si no que bloquea la salida de mitosis. Sin embargo, aunque no hay un incremento en el numero de células, el silenciamiento de hippo produce la aparición de sobrecrecimientos, precedidos por la aparición de amplias regiones compuestas por células no diferen ciadas, yla reducción del numero de células diferenciadas en todo el animal. El estudio detallado del linaje epidermico, demuestra que hippo es necesario para determinar las transiciones jerarquicas requeridas para una correcta diferenciación de las células epidermicas. Ademas, demostramos que hippo es necesario para mantener el estado diferenciado de las células, ya que su inhibición promueve la desdiferen ciación de células postmitóticas. En conjunto, estos resultados indican que los sobrecrecimientos y regiones indiferenciadas observadas despues de la inhibición de hippo no son causados por el desequilibrio entre la muerte celular y la proliferac ión sino por la incapacidad de las células adquirir y mantener su estado diferenciado. Ademas, durante este estudio hemos demostrado que la cascada de sena lización Hippo-Yki esta conservada en planarias y desempeña un papel fundamental durante la regeneración. También hemos visto que los mecanismos reguladores "up-stream " de la via Hippo parecen estar conservados en planarias, ya que la inhibición de algunos elementos, como lg/2, fenocopia el fenotipo de los animales hippo (RNAi). A su vez, el analisis transcriptómico de los animales hippo (RNAi) ha permitido identificar genes diana de la vía Hippo en planarias. El silenciamiento de algunos de estos genes candidatos también promueve la aparición de sobrecrecimientos. Para finalizar, nuestros estudios nos permiten proponer que el papel principal de Hippo en las planarias es restringir la plasticidad celular y así prevenir la transformación tumoral

The pioneer factor Smed-gata456-1 is required for gut cell differentiation and maintenance in planarians

How adult stem cells differentiate into different cell types remains one of the most intriguing questions in regenerative medicine. Pioneer factors are transcription factors that can bind to and open chromatin, and are among the first elements involved in cell differentiation. We used the freshwater planarian Schmidtea mediterranea as a model system to study the role of the gata456 family of pioneer factors in gut cell differentiation during both regeneration and maintenance of the digestive system. Our findings reveal the presence of two members of the gata456 family in the Schmidtea mediterranea genome; Smed-gata456-1 and Smed-gata456-2. Our results show that Smed-gata456-1 is the only ortholog with a gut cell-related function. Smed-gata456-1 is essential for the differentiation of precursors into intestinal cells and for the survival of these differentiated cells, indicating a key role in gut regeneration and maintenance. Furthermore, tissues other than the gut appear normal following Smed-gata456-1 RNA interference (RNAi), indicating a gut-specific function. Importantly, different neoblast subtypes are unaffected by Smed-gata456-1(RNAi), suggesting that 1) Smed-gata456-1 is involved in the differentiation and maintenance, but not in the early determination, of gut cells; and 2) that the stem cell compartment is not dependent on a functional gut

Hippo signaling controls cell cycle and restricts cell plasticity in planarians.

Constant cell renewal is required to maintain healthy organs during adult homeostasis. The highly conserved Hippo signaling pathway is essential for the regulation of basic cell behaviors that underlie tissue renewal, including cell proliferation, cell differentiation, and cell death. The Hippo protein has been implicated in several human cancers, and its inhibition in mouse and Drosophila promotes the formation of overgrowths. Nonetheless, its biological function remains poorly understood. To address this issue, we studied the role of Hippo in planarians, flatworms that continuously alter their size depending on nutrient availability, and therefore have a high rate of cellular turnover. This ability is sustained by an abundant population of adult totipotent stem cells. We show that hippo inhibition in planarians decreases apoptotic cell death, impairs cell progression through the cell cycle, and causes instability of the differentiated cell fate. These events ultimately lead to the formation of overgrowths consisting of undifferentiated cells. We propose that the main role of Hippo in planarians is not to promote proliferation but to control the cell cycle and maintain a stable differentiated cell fate

Terpenes and steroids from leaves of Oxandra sessiliflora R. E. Fries

The EtOH extract from the leaves of Oxandra sessiliflora R. E. Fries (Annonaceae) was partitioned using hexane and CH2Cl2. After several chromatographic steps, caryophyllene oxide and spathulenol were isolated from hexane phase while, from CH2Cl2 phase, we isolated (E)-phytol, spathulenol, 4 beta,10 alpha-dihydroxyaromadendrane, 1 beta,6 alpha-dihydroxyeudesm-4(15)-ene, and 4 alpha, 7 beta, 10 alpha-trihydroxyguai-5-ene, the latter being a new sesquiterpene derivative. Additionally, a mixture of steroids (campesterol, sitosterol, and stigmasterol) was obtained from the CH2Cl2 phase. the isolated compounds were characterized by mass spectrometry and analysis of their H-1 and C-13 NMR spectroscopic data, including bidimensional analysis. (C) 2013 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Fed Piaui, Dept Quim, BR-64049550 Teresina, PI, BrazilUniv Fed Bahia, Inst Quim, BR-40170280 Salvador, BA, BrazilUniv Fed Mato Grosso, Inst Ciencias Nat Humanas & Sociais, BR-78557267 Sinop, MT, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema, SP, BrazilWeb of Scienc

Transcriptomic analysis of Planarians under simulated microgravity or 8g demonstrates that alteration of gravity induces genomic and cellular alterations that could facilitate tumoral transformation

The possibility of humans to live outside of Earth on another planet has attracted the attention of numerous scientists around the world. One of the greatest difficulties is that humans cannot live in an extra-Earth environment without proper equipment. In addition, the consequences of chronic gravity alterations in human body are not known. Here, we used planarians as a model system to test how gravity fluctuations could affect complex organisms. Planarians are an ideal system, since they can regenerate any missing part and they are continuously renewing their tissues. We performed a transcriptomic analysis of animals submitted to simulated microgravity (Random Positioning Machine, RPM) (s-µg) and hypergravity (8 g), and we observed that the transcriptional levels of several genes are affected. Surprisingly, we found the major differences in the s-µg group. The results obtained in the transcriptomic analysis were validated, demonstrating that our transcriptomic data is reliable. We also found that, in a sensitive environment, as under Hippo signaling silencing, gravity fluctuations potentiate the increase in cell proliferation. Our data revealed that changes in gravity severely affect genetic transcription and that these alterations potentiate molecular disorders that could promote the development of multiple diseases such as cance