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1.
Science ; 367(6479): 757-762, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-32054756

RESUMO

Clonal animals do not sequester a germ line during embryogenesis. Instead, they have adult stem cells that contribute to somatic tissues or gametes. How germ fate is induced in these animals, and whether this process is related to bilaterian embryonic germline induction, is unknown. We show that transcription factor AP2 (Tfap2), a regulator of mammalian germ lines, acts to commit adult stem cells, known as i-cells, to the germ cell fate in the clonal cnidarian Hydractinia symbiolongicarpus Tfap2 mutants lacked germ cells and gonads. Transplanted wild-type cells rescued gonad development but not germ cell induction in Tfap2 mutants. Forced expression of Tfap2 in i-cells converted them to germ cells. Therefore, Tfap2 is a regulator of germ cell commitment across germ line-sequestering and germ line-nonsequestering animals.


Assuntos
Células-Tronco Adultas/citologia , Gametogênese/fisiologia , Células Germinativas/citologia , Gônadas/embriologia , Hidrozoários/embriologia , Fator de Transcrição AP-2/fisiologia , Células-Tronco Adultas/metabolismo , Animais , Feminino , Gametogênese/genética , Regulação da Expressão Gênica no Desenvolvimento , Gônadas/citologia , Hidrozoários/citologia , Hidrozoários/genética , Masculino , Fator de Transcrição AP-2/genética
2.
Keio J Med ; 68(4): 95, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31875622

RESUMO

Stem cells are the foundation of all mammalian life. Stem cells build and maintain our bodies throughout life. Two types of stem cells are discerned.1) Embryonic stem cells (ES cells) are briefly present in the early human or mouse embryo, a few days after fertilization. These ES cells can be grown indefinitely in the lab and have the potential to build each and every tissue in our body. Because of this 'pluripotency', ES cells hold great promise for therapeutic application in the field of regenerative medicine. It is also possible to take skin cells (or other cells) from adults and convert these in the lab into cells with ES properties, so called iPS cells. Many of the hurdles that ES cell technology have faced, do not exist for iPS cells.2) Adult stem cells. Every organ in our body is believed to harbor its own dedicated stem cells. These adult stem cells replace tissue that is lost due to wear and tear, trauma and disease. Adult stem cells are highly specialized and can only produce the tissue in which they reside; they are 'multipotent'. Examples are bone marrow stem cells that make all blood cells, skin stem cells and gut stem cells. Even the brain is now known to harbor its specialized stem cells. The adult stem cells allow us to live 80-90 years, but this comes at a cost: they are the cells that most easily transform into cancer cells.Both types of stem cells can be used to establish 'organoids', 3D structures established in a dish, that recapitulate many aspects of the organ they represent. Pluripotent stem cells can be taken through the developmental steps that establish organs during embryogenesis. This has worked particularly well for parts of the the central nervous system, the kidney and GI organs. We have shown that adult epithelial stem cells carrying the generic Lgr5 marker can be cultured under tissue-repair conditions and generate epithelial organoids directly from healthy and diseased organs such as the gut, the liver, the lung and the pancreas. Organoid technology opens a range of avenues for the study of development, physiology and disease, for drug development and for personalized medicine. In the long run, cultured mini-organs may replace transplant organs from donors and hold promise in gene therapy.


Assuntos
Células-Tronco Adultas/citologia , Células-Tronco Embrionárias/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Organoides/citologia , Medicina de Precisão/métodos , Medicina Regenerativa/métodos , Células-Tronco Adultas/metabolismo , Animais , Biomarcadores/metabolismo , Diferenciação Celular , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Células-Tronco Embrionárias/metabolismo , Expressão Gênica , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Especificidade de Órgãos , Organoides/metabolismo , Organoides/transplante , Receptores Acoplados a Proteínas-G/genética , Receptores Acoplados a Proteínas-G/metabolismo
3.
Int J Mol Sci ; 20(20)2019 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-31614903

RESUMO

The main goal of bone tissue engineering (BTE) is to refine and repair major bone defects based on bioactive biomaterials with distinct properties that can induce and support bone tissue formation. Graphene and its derivatives, such as graphene oxide (GO), display optimal properties for BTE, being able to support cell growth and proliferation, cell attachment, and cytoskeleton development as well as the activation of osteogenesis and bone development pathways. Conversely, the presence of GO within a polymer matrix produces favorable changes to scaffold morphologies that facilitate cell attachment and migration i.e., more ordered morphologies, greater surface area, and higher total porosity. Therefore, there is a need to explore the potential of GO for tissue engineering applications and regenerative medicine. Here, we aim to promote one novel scaffold based on a natural compound of chitosan, improved with 3 wt.% GO, for BTE approaches, considering its good biocompatibility, remarkable 3D characteristics, and ability to support stem cell differentiation processes towards the bone lineage.


Assuntos
Osso e Ossos/citologia , Quitosana/química , Grafite/química , Osteogênese , Engenharia Tecidual/métodos , Tecidos Suporte , Células-Tronco Adultas/citologia , Materiais Biocompatíveis/química , Regeneração Óssea , Osso e Ossos/ultraestrutura , Diferenciação Celular , Proliferação de Células , Humanos , Teste de Materiais , Conformação Molecular , Osteócitos/citologia , Osteócitos/ultraestrutura , Porosidade
4.
Int J Mol Sci ; 20(19)2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31575089

RESUMO

Diabetic retinopathy (DR), a complication of diabetes, is one of the leading causes of blindness in working-age adults. The pathology of the disease prevents the endogenous stem cells from participating in the natural repair of the diseased retina. Current treatments, specifically stem cell therapeutics, have shown variable efficacy in preclinical models due to the multi-faceted nature of the disease. Among the various adult stem cells, mesenchymal stem cells, especially those derived from adipose tissue and bone marrow, have been explored as a possible treatment for DR. This review summarizes the current literature around the various adult stem cell treatments for the disease and outlines the benefits and limitations of the therapeutics that are being explored in the field. The paracrine nature of adipose stem cells, in particular, has been highlighted as a potential solution to the lack of a homing and conducive environment that poses a challenge to the implantation of exogenous stem cells in the target tissue. Various methods of mesenchymal stem cell priming to adapt to a hostile retinal microenvironment have been discussed. Current clinical trials and potential safety concerns have been examined, and the future directions of stem cell therapeutics in DR have also been contemplated.


Assuntos
Células-Tronco Adultas/metabolismo , Retinopatia Diabética/terapia , Transplante de Células-Tronco , Células-Tronco Adultas/citologia , Animais , Biomarcadores , Adesão Celular , Humanos , Comunicação Parácrina , Fenótipo , Transplante de Células-Tronco/efeitos adversos , Transplante de Células-Tronco/métodos
5.
Mol Biol (Mosk) ; 53(5): 711-724, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31661473

RESUMO

Blood is extremely important for a multicellular organism: it connects all organs and tissues, supplies them with nutrients and oxygen, removes carbon dioxide and metabolic products, maintains homeostasis, and provides protection against infections. That is why studies on blood have always drawn a great deal of attention. In ancient times, it was believed that the soul was in the blood and that it sometimes "sank into the stomach." Initially, the study of blood was limited to morphological methods, to which physiological and cellular research were added in the twentieth century. With their help, researchers established that mature blood cells are formed from a rare population of hematopoietic stem cells (HSCs), which are located in the bone marrow. The development of molecular biology methods and their combination with classical physiological ones allowed a breakthrough in understanding the structure of the hematopoietic system, which changed our understanding not only of hematopoiesis but also about the nature of adult stem cells. This review describes the molecular assays used in experimental hematology, and how their application has gradually been expanding our knowledge of blood formation and continues to provide new information about it.


Assuntos
Hematopoese , Sistema Hematopoético/citologia , Sistema Hematopoético/fisiologia , Biologia Molecular/métodos , Células-Tronco Adultas/citologia , Medula Óssea , Células-Tronco Hematopoéticas/citologia , Humanos
6.
Mol Cells ; 42(9): 661-671, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31564076

RESUMO

Adipose tissue-derived mesenchymal stem cells (ADSCs) are promising for regenerating degenerated intervertebral discs (IVDs), but the low efficiency of nucleus pulposus (NP)-specific differentiation limits their clinical applications. The Sonic hedgehog (Shh) signaling pathway is important in NP-specific differentiation of ADSCs, and Smoothened Agonist (SAG) is a highly specific and effective agonist of Shh signaling. In this study, we proposed a new differentiation strategy with the use of the small molecule SAG. The NP-specific differentiation and extracellular matrix (ECM) synthesis of ADSCs were measured in vitro , and the regenerative effects of SAG pretreated ADSCs in degenerated IVDs were verified in vivo . The results showed that the combination of SAG and transforming growth factor-ß3 (TGF-ß3) is able to increase the ECM synthesis of ADSCs. In addition, the gene and protein expression levels of NP-specific markers were increased by treatment with SAG and TGF-ß3. Furthermore, SAG pretreated ADSCs can also improve the disc height, water content, ECM content, and structure of degenerated IVDs in vivo . Our new differentiation scheme has high efficiency in inducing NP-specific differentiation of ADSCs and is promising for stem cell-based treatment of degenerated IVDs.


Assuntos
Tecido Adiposo/citologia , Diferenciação Celular , Células-Tronco Mesenquimais/citologia , Núcleo Pulposo/citologia , Bibliotecas de Moléculas Pequenas/farmacologia , Células-Tronco Adultas/citologia , Animais , Diferenciação Celular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Proteínas Hedgehog/metabolismo , Humanos , Degeneração do Disco Intervertebral/diagnóstico por imagem , Degeneração do Disco Intervertebral/patologia , Imagem por Ressonância Magnética , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Ratos Sprague-Dawley , Transdução de Sinais , Receptor Smoothened/agonistas , Fator de Crescimento Transformador beta3/metabolismo
7.
In Vivo ; 33(5): 1447-1454, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31471391

RESUMO

BACKGROUND/AIM: Results of Guided Bone Regeneration (GBR) primarily depend on the membrane used. The aim of this study was to compare biocompatibility of different absorbable and non-absorbable membranes by using unrestricted somatic stem cells (USSCs) as an indicator for biocompatibility. MATERIALS AND METHODS: Five absorbable membranes (Bio-Gide®, RESODONT®, GENTA-FOIL resorb®, BioMend® and BioMend® Extend™) and one non-absorbable alternative (GORE-TEX®) were colonized with USSCs. After 24 h, 3 days and 7 days, cell proliferation, cell viability, and cytotoxicity were assessed. Moreover, cell morphology was evaluated by electron microscopy. RESULTS: Significantly higher cell proliferation and cell viability rates were observed in Bio-Gide® and RESODONT® membranes. Cell toxicity was highest on GENTA-FOIL resorb® membranes. The electron microscopical assessment showed a better cell attachment on porous surfaced membranes. CONCLUSION: This study shows that USSCs can be used for assessments of biocompatibility, and that absorbable membranes with collagenous composition and porous structure tend to positively impact biocompatibility and enhance cell proliferation.


Assuntos
Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Materiais Biocompatíveis , Regeneração Óssea , Membranas Artificiais , Materiais Biocompatíveis/química , Proliferação de Células , Sobrevivência Celular
8.
Int J Mol Sci ; 20(17)2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31480215

RESUMO

The mammalian brain is enriched with lipids that serve as energy catalyzers or secondary messengers of essential signaling pathways. Docosahexaenoic acid (DHA) is an omega-3 fatty acid synthesized de novo at low levels in humans, an endogenous supply from its precursors, and is mainly incorporated from nutrition, an exogeneous supply. Decreased levels of DHA have been reported in the brains of patients with neurodegenerative diseases. Preventing this decrease or supplementing the brain with DHA has been considered as a therapy for the DHA brain deficiency that could be linked with neuronal death or neurodegeneration. The mammalian brain has, however, a mechanism of compensation for loss of neurons in the brain: neurogenesis, the birth of neurons from neural stem cells. In adulthood, neurogenesis is still present, although at a slower rate and with low efficiency, where most of the newly born neurons die. Neural stem/progenitor cells (NSPCs) have been shown to require lipids for proper metabolism for proliferation maintenance and neurogenesis induction. Recent studies have focused on the effects of these essential lipids on the neurobiology of NSPCs. This review aimed to introduce the possible use of DHA to impact NSPC fate-decision as a therapy for neurodegenerative diseases.


Assuntos
Células-Tronco Adultas/citologia , Linhagem da Célula/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/farmacologia , Células-Tronco Neurais/citologia , Células-Tronco Adultas/efeitos dos fármacos , Células-Tronco Adultas/metabolismo , Animais , Humanos , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Neurogênese/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia
9.
DNA Cell Biol ; 38(11): 1313-1322, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31545082

RESUMO

This study investigated whether overexpression of paired-related homeobox 1 (prrx1) can successfully induce differentiation of brown adipose-derived stem cells (BADSCs) into sinus node-like cells. The experiments were performed in two groups: adenovirus-green fluorescent protein (Ad-GFP) group and Ad-prrx1 group. After 5-7 days of adenoviral transfection, the expression levels of sinus node cell-associated pacing protein (hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 [HCN4]) and ion channel (calcium channel, voltage-dependent, T type, alpha 1G subunit [Cacna1g]), as well as transcription factors (T-box 18 [TBX18], insulin gene enhancer binding protein 1 [ISL-1], paired-like homeodomain transcription factor 2 [pitx2], short stature homeobox 2 [shox2]), were detected by western blot and reverse transcription-quantitative polymerase chain reaction. Immunofluorescence assay was carried out to detect whether prrx1 was coexpressed with HCN4, TBX18, and ISL-1. Finally, whole-cell patch-clamp technique was used to record pacing current hyperpolarization-activated inward current (If). The isolated cells were CD90+, CD29+, and CD45-, indicating that pure BADSCs were successfully isolated. After 5-7 days of Ad transfection into cells, the mRNA levels and protein levels of pacing-related factors (TBX18, ISL-1, HCN4, shox2, and Cacna1g) in Ad-prrx1 group were significantly higher than those in Ad-GFP group. However, the expression level of pitx2 was decreased. Immunofluorescence analysis showed that prrx1 was coexpressed with TBX18, ISL-1, and HCN4 in the Ad-prrx1 group, which did not appear in the Ad-GFP group. Whole-cell patch clamps were able to record the If current in the experimental group rather than in the Ad-GFP group. Overexpression of prrx1 can successfully induce sinus node-like cells.


Assuntos
Tecido Adiposo Marrom/fisiologia , Células-Tronco Adultas/fisiologia , Diferenciação Celular/genética , Proteínas de Homeodomínio/fisiologia , Nó Sinoatrial/fisiologia , Tecido Adiposo Marrom/citologia , Células-Tronco Adultas/citologia , Animais , Transdiferenciação Celular/genética , Células Cultivadas , Masculino , Ratos , Ratos Sprague-Dawley , Nó Sinoatrial/citologia , Transfecção
10.
Genetics ; 213(1): 9-26, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31488592

RESUMO

The long-term survival of any multicellular species depends on the success of its germline in producing high-quality gametes and maximizing survival of the offspring. Studies in Drosophila melanogaster have led our growing understanding of how germline stem cell (GSC) lineages maintain their function and adjust their behavior according to varying environmental and/or physiological conditions. This review compares and contrasts the local regulation of GSCs by their specialized microenvironments, or niches; discusses how diet and diet-dependent factors, mating, and microorganisms modulate GSCs and their developing progeny; and briefly describes the tie between physiology and development during the larval phase of the germline cycle. Finally, it concludes with broad comparisons with other organisms and some future directions for further investigation.


Assuntos
Drosophila melanogaster/genética , Gametogênese , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Animais , Drosophila melanogaster/crescimento & desenvolvimento , Interação Gene-Ambiente , Nicho de Células-Tronco
11.
PLoS One ; 14(7): e0219938, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31335913

RESUMO

Podoplanin (PDPN) is a glycoprotein that is expressed by various cell types, including keratinocytes, fibroblasts, and lymphatic endothelial cells. We found that PDPN is expressed in the hair follicle (HF) keratinocyte region and HF stem cell area during the late anagen phase but not during the telogen phase in mice. Importantly, keratinocyte-specific PDPN deletion in mice (K5-Cre;PDPNflox/flox) promoted anagen HF growth after depilation-induced HF regeneration as compared to control mice. RNA sequencing, followed by gene ontology analysis, showed down-regulation of focal adhesion and extracellular matrix interaction pathways in HF stem cells isolated from K5-Cre;PDPNflox/flox mice as compared to control mice. Furthermore, HF keratinocytes isolated from K5-Cre;PDPNflox/flox mice exhibited a decreased ability to interact with collagen type I in cell adhesion assays. Taken together, these results show that PDPN deletion promotes HF cycling, possibly via reduced focal adhesion and concomitantly enhanced migration of HF stem cells towards the bulb region. They also indicate potential new therapeutic strategies for the treatment of conditions associated with hair loss.


Assuntos
Folículo Piloso/crescimento & desenvolvimento , Glicoproteínas de Membrana/metabolismo , Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/fisiologia , Animais , Movimento Celular , Células Cultivadas , Colágeno Tipo I/metabolismo , Matriz Extracelular/metabolismo , Feminino , Adesões Focais/metabolismo , Folículo Piloso/citologia , Folículo Piloso/metabolismo , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Queratinócitos/fisiologia , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL
12.
Cells ; 8(7)2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31315286

RESUMO

Diabetic foot ulcers (DFUs) are lesions that involve loss of epithelium and dermis, sometimes involving deep structures, compartments, and bones. The aim of this work is to investigate the innate regenerative properties of dermal tissue around ulcers by the identification and analysis of resident dermal stem cells (DSCs). Dermal samples were taken at the edge of DFUs, and genes related to the wound healing process were analyzed by the real-time PCR array. The DSCs were isolated and analyzed by immunofluorescence, flow cytometry, and real-time PCR array to define their stemness properties. The gene expression profile of dermal tissue showed a dysregulation in growth factors, metalloproteinases, collagens, and integrins involved in the wound healing process. In the basal condition, diabetic DSCs adhered on the culture plate with spindle-shaped fibroblast-like morphology. They were positive to the mesenchymal stem cells markers CD44, CD73, CD90, and CD105, but negative for the hematopoietic markers CD14, CD34, CD45, and HLA-DR. In diabetic DSCs, the transcription of genes related to self-renewal and cell division were equivalent to that in normal DSCs. However, the expression of CCNA2, CCND2, CDK1, ALDH1A1, and ABCG2 was downregulated compared with that of normal DSCs. These genes are also related to cell cycle progression and stem cell maintenance. Further investigation will improve the understanding of the molecular mechanisms by which these genes together govern cell proliferation, revealing new strategies useful for future treatment of DFUs.


Assuntos
Células-Tronco Adultas/metabolismo , Derme/citologia , Pé Diabético/patologia , Transcriptoma , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Células-Tronco Adultas/citologia , /metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Proteína Quinase CDC2/genética , Proteína Quinase CDC2/metabolismo , Diferenciação Celular , Células Cultivadas , Ciclina A2/genética , Ciclina A2/metabolismo , Ciclina D2/genética , Ciclina D2/metabolismo , Derme/patologia , Regulação para Baixo , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Retinal Desidrogenase/genética , Retinal Desidrogenase/metabolismo
13.
Mol Med Rep ; 20(3): 2763-2773, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31322240

RESUMO

Ectomesenchymal stem cells (EMSCs) represent a type of adult stem cells derived from the cranial neural crest. These cells are capable of self­renewal and have the potential for multidirectional differentiation. Tissue transglutaminase type 2 (TG2) is a ubiquitously expressed member of the transglutaminase family of Ca2+­dependent crosslinking enzymes. However, the effect of TG2 on neural differentiation and proliferation of EMSCs remains unknown. To determine whether TG2 improves EMSC proliferation and neurogenesis, a stable TG2­overexpressing EMSC cell line (TG2­EMSCs) was established by using an adenovirus system. Immunofluorescence staining and western blot analyses demonstrated that TG2 overexpression had beneficial effects on the rate of EMSC neurogenesis, and that the proliferative capacity of TG2­EMSCs was higher than that of controls. Furthermore, the results of western blotting revealed that extracellular matrix (ECM) and neurotrophic factors were upregulated during the differentiation of TG2­EMSCs. Notably, TG2­EMSC transplantation in an animal model of spinal cord injury (SCI), TG2­EMSCs differentiated into neuron­like cells and enhanced the repair of SCI. Taken together, these results demonstrated that TG2 gene transfection may offer a novel strategy to enhance EMSC proliferation and neurogenesis in vivo and in vitro, which may ultimately facilitate EMSC­based transplantation therapy in patients with SCI.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Neurogênese , Traumatismos da Medula Espinal/terapia , Transglutaminases/genética , Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/transplante , Animais , Linhagem Celular , Feminino , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/transplante , Ratos , Ratos Sprague-Dawley , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/fisiopatologia , Regulação para Cima
14.
Soft Matter ; 15(25): 5154-5162, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31192342

RESUMO

In vivo cell niches are complex architectures that provide a wide range of biochemical and mechanical stimuli to control cell behavior and fate. With the aim to provide in vitro microenvironments mimicking physiological niches, microstructured substrates have been exploited to support cell adhesion and to control cell shape as well as three dimensional morphology. At variance with previous methods, we propose a simple and rapid protein subtractive soft lithographic method to obtain microstructured polydimethylsiloxane substrates for studying stem cell adhesion and growth. The shape of adult renal stem cells and nuclei is found to depend predominantly on micropatterning of elastomeric surfaces and only weakly on the substrate mechanical properties. Differently, focal adhesions in their shape and density but not in their alignment mainly depend on the elastomer stiffness almost regardless of microscale topography. Local surface topography with concave microgeometry enhancing adhesion drives stem cells in a quasi-three dimensional configuration where stiffness might significantly steer mechanosensing as highlighted by focal adhesion properties.


Assuntos
Células-Tronco Adultas/citologia , Células-Tronco Adultas/efeitos dos fármacos , Elastômeros/farmacologia , Adesões Focais/efeitos dos fármacos , Adesões Focais/metabolismo , Fenômenos Mecânicos/efeitos dos fármacos , Fenômenos Biomecânicos/efeitos dos fármacos , Dimetilpolisiloxanos/farmacologia , Humanos , Nylons/farmacologia , Propriedades de Superfície
15.
Genomics Proteomics Bioinformatics ; 17(2): 154-168, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31154015

RESUMO

N6-methyladenosine (m6A), catalyzed by the methyltransferase complex consisting of Mettl3 and Mettl14, is the most abundant RNA modification in mRNAs and participates in diverse biological processes. However, the roles and precise mechanisms of m6A modification in regulating neuronal development and adult neurogenesis remain unclear. Here, we examined the function of Mettl3, the key component of the complex, in neuronal development and adult neurogenesis of mice. We found that the depletion of Mettl3 significantly reduced m6A levels in adult neural stem cells (aNSCs) and inhibited the proliferation of aNSCs. Mettl3 depletion not only inhibited neuronal development and skewed the differentiation of aNSCs more toward glial lineage, but also affected the morphological maturation of newborn neurons in the adult brain. m6A immunoprecipitation combined with deep sequencing (MeRIP-seq) revealed that m6A was predominantly enriched in transcripts related to neurogenesis and neuronal development. Mechanistically, m6A was present on the transcripts of histone methyltransferase Ezh2, and its reduction upon Mettl3 knockdown decreased both Ezh2 protein expression and consequent H3K27me3 levels. The defects of neurogenesis and neuronal development induced by Mettl3 depletion could be rescued by Ezh2 overexpression. Collectively, our results uncover a crosstalk between RNA and histone modifications and indicate that Mettl3-mediated m6A modification plays an important role in regulating neurogenesis and neuronal development through modulating Ezh2.


Assuntos
Adenosina/análogos & derivados , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Neurogênese , Neurônios/metabolismo , Adenosina/metabolismo , Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Animais , Encéfalo/metabolismo , Diferenciação Celular/genética , Proliferação de Células , Regulação da Expressão Gênica , Metiltransferases/metabolismo , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Neurônios/citologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
16.
Int J Dev Biol ; 63(6-7): 295-299, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31250913

RESUMO

We have successfully isolated cells with stem-like properties from bottlenose dolphin (Tursiops truncatus) umbilical cord. Our results show that this cetacean species has embryonic fetal and adult stem cells as do humans and other studied mammals. This accomplishment allows to eventually investigate whether dolphins, due to their unique adaptations to aquatic environments, have special stem cell lineages or distinctive mechanisms of cell programming. Further characterization of their potency to differentiate into multiple cell lineages would fulfill numerous applicative purposes. We characterized, developed and refined a new protocol for obtaining potential stem cells from umbilical cord tissues of the bottlenose dolphin. Tissue samples were taken from umbilical cords of successful deliveries immediately after placenta ejection and collection from the water. Umbilical cord samples (2-3 cm3) were excised and subjected to enzymatic digestion and mechanical dissociation. Viable cells from specimens resident in the Oceanografic Valencia were cultured and subsequently isolated and tested for pluripotent characteristics (cell morphology, phenotype and expression of surface markers). Cell viability was confirmed also after freezing/thawing. The established protocol is suitable for collection/isolation/culture of dolphin potential mesenchymal stem cells from dolphin umbilical cord, which can be deposited in cell banks for future research needs.


Assuntos
Células-Tronco Adultas/citologia , Golfinho Nariz-de-Garrafa/metabolismo , Separação Celular/métodos , Células-Tronco Embrionárias/citologia , Células-Tronco Fetais/citologia , Células-Tronco Mesenquimais/citologia , Cordão Umbilical/citologia , Células-Tronco Adultas/metabolismo , Animais , Biomarcadores/metabolismo , Diferenciação Celular , Células Cultivadas , Células-Tronco Embrionárias/metabolismo , Feminino , Células-Tronco Fetais/metabolismo , Células-Tronco Mesenquimais/metabolismo , Cordão Umbilical/metabolismo
17.
Genetics ; 212(3): 655-665, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31126976

RESUMO

Microsatellite sequences have an enhanced susceptibility to mutation, and can act as sentinels indicating elevated mutation rates and increased risk of cancer. The probability of mutant fixation within the intestinal epithelium is dictated by a combination of stem cell dynamics and mutation rate. Here, we exploit this relationship to infer microsatellite mutation rates. First a sensitive, multiplexed, and quantitative method for detecting somatic changes in microsatellite length was developed that allowed the parallel detection of mutant [CA]n sequences from hundreds of low-input tissue samples at up to 14 loci. The method was applied to colonic crypts in Mus musculus, and enabled detection of mutant subclones down to 20% of the cellularity of the crypt (∼50 of 250 cells). By quantifying age-related increases in clone frequencies for multiple loci, microsatellite mutation rates in wild-type and Msh2-deficient epithelium were established. An average 388-fold increase in mutation per mitosis rate was observed in Msh2-deficient epithelium (2.4 × 10-2) compared to wild-type epithelium (6.2 × 10-5).


Assuntos
Células-Tronco Adultas/metabolismo , Mucosa Intestinal/citologia , Repetições de Microssatélites , Proteína 2 Homóloga a MutS/genética , Taxa de Mutação , Células-Tronco Adultas/citologia , Animais , Feminino , Mucosa Intestinal/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitose , Proteína 2 Homóloga a MutS/deficiência
18.
Genes Dev ; 33(9-10): 479-481, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31043492

RESUMO

Adult neural stem cells are mostly quiescent and only rarely enter the cell cycle to self-renew and generate neuronal or glial progenies. The Notch signaling pathway is essential for both the quiescent and proliferative states of neural stem cells. However, these are mutually exclusive cellular states; thus, how Notch promotes both of these programs within adult neural stem cells has remained unclear. In this issue of Genes & Development, Sueda and colleagues (pp. 511-523) use an extensive repertoire of mouse genetic tools and techniques to demonstrate that it is the levels and dynamic expression of the Notch transcriptional effector Hairy and Enhancer of Split 1 that enables this dual role.


Assuntos
Células-Tronco Adultas/citologia , Células-Tronco Neurais/citologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Ciclo Celular , Camundongos , Sistema Nervoso , Transdução de Sinais , Fatores de Transcrição HES-1
19.
Tissue Cell ; 58: 51-60, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31133246

RESUMO

Tissue-specific adult stem cells (ASC) are heterogeneous and characterized by a mix of progenitor cells that produce cells at various stages of differentiation, and ultimately different terminally differentiated cells. Understanding the heterogeneity of ASCs may lead to the development of improved protocols of cell isolation and optimized cell therapy clinical protocols. Using a combination of enzymatic and explant culture protocols, we obtained pADSC population, which is composed by two distinct morphologies: fibroblast-like cells (FLCs) and endothelial-like cells (ELCs). Both cell sub-types efficiently formed colonies, expressed CD90+/CD105+/CD44+, and differentially expressed such markers such as Nestin, Vimentin, Fibronectin, Cytokeratin, Connexin 43, CD31, CD34 and CD146 as well as the pluripotent stem cell markers Oct-4, Nanog and Sox2. Mixed populations of pADSCs did not lose their multipotentiality and the cells were able to undergo osteogenic, chondrogenic, adipogenic and myogenic differentiation. Furthermore, the mixed population spontaneously formed capillary tube structures. Our findings suggest that different subpopulations can be isolated from adipose tissue and that the ADSCs need to be better evaluated using a wide panel of different markers related to cell differentiation, which is important for stem cell therapy and regenerative medicine, particularly for advanced stem cells therapies - products that are currently under investigation or even use.


Assuntos
Tecido Adiposo/metabolismo , Células-Tronco Adultas/metabolismo , Antígenos de Diferenciação/metabolismo , Separação Celular , Células-Tronco Pluripotentes/metabolismo , Tecido Adiposo/citologia , Células-Tronco Adultas/citologia , Animais , Células-Tronco Pluripotentes/citologia , Suínos
20.
Int J Mol Sci ; 20(9)2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31052375

RESUMO

Cells of unicellular and multicellular eukaryotes can respond to certain environmental cues by arresting the cell cycle and entering a reversible state of quiescence. Quiescent cells do not divide, but can re-enter the cell cycle and resume proliferation if exposed to some signals from the environment. Quiescent cells in mammals and humans include adult stem cells. These cells exhibit improved stress resistance and enhanced survival ability. In response to certain extrinsic signals, adult stem cells can self-renew by dividing asymmetrically. Such asymmetric divisions not only allow the maintenance of a population of quiescent cells, but also yield daughter progenitor cells. A multistep process of the controlled proliferation of these progenitor cells leads to the formation of one or more types of fully differentiated cells. An age-related decline in the ability of adult stem cells to balance quiescence maintenance and regulated proliferation has been implicated in many aging-associated diseases. In this review, we describe many traits shared by different types of quiescent adult stem cells. We discuss how these traits contribute to the quiescence, self-renewal, and proliferation of adult stem cells. We examine the cell-intrinsic mechanisms that allow establishing and sustaining the characteristic traits of adult stem cells, thereby regulating quiescence entry, maintenance, and exit.


Assuntos
Células-Tronco Adultas/citologia , Pontos de Checagem do Ciclo Celular , Divisão Celular , Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/fisiologia , Animais , Diferenciação Celular , Humanos , Transdução de Sinais
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