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1.
Nature ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987594

RESUMO

Changes in the gut microbiome have pivotal roles in the pathogenesis of acute graft-versus-host disease (aGVHD) after allogenic haematopoietic cell transplantation (allo-HCT)1-6. However, effective methods for safely resolving gut dysbiosis have not yet been established. An expansion of the pathogen Enterococcus faecalis in the intestine, associated with dysbiosis, has been shown to be a risk factor for aGVHD7-10. Here we analyse the intestinal microbiome of patients with allo-HCT, and find that E. faecalis escapes elimination and proliferates in the intestine by forming biofilms, rather than by acquiring drug-resistance genes. We isolated cytolysin-positive highly pathogenic E. faecalis from faecal samples and identified an anti-E. faecalis enzyme derived from E. faecalis-specific bacteriophages by analysing bacterial whole-genome sequencing data. The antibacterial enzyme had lytic activity against the biofilm of E. faecalis in vitro and in vivo. Furthermore, in aGVHD-induced gnotobiotic mice that were colonized with E. faecalis or with patient faecal samples characterized by the domination of Enterococcus, levels of intestinal cytolysin-positive E. faecalis were decreased and survival was significantly increased in the group that was treated with the E. faecalis-specific enzyme, compared with controls. Thus, administration of a phage-derived antibacterial enzyme that is specific to biofilm-forming pathogenic E. faecalis-which is difficult to eliminate with existing antibiotics-might provide an approach to protect against aGVHD.

2.
Nature ; 561(7722): 243-247, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30185909

RESUMO

Large cutaneous ulcers are, in severe cases, life threatening1,2. As the global population ages, non-healing ulcers are becoming increasingly common1,2. Treatment currently requires the transplantation of pre-existing epithelial components, such as skin grafts, or therapy using cultured cells2. Here we develop alternative supplies of epidermal coverage for the treatment of these kinds of wounds. We generated expandable epithelial tissues using in vivo reprogramming of wound-resident mesenchymal cells. Transduction of four transcription factors that specify the skin-cell lineage enabled efficient and rapid de novo epithelialization from the surface of cutaneous ulcers in mice. Our findings may provide a new therapeutic avenue for treating skin wounds and could be extended to other disease situations in which tissue homeostasis and repair are impaired.


Assuntos
Reprogramação Celular , Células Epiteliais/citologia , Úlcera Cutânea/patologia , Pele/citologia , Ferimentos e Lesões/patologia , Animais , Linhagem da Célula , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Camundongos , Medicina Regenerativa , Pele/patologia , Úlcera Cutânea/terapia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Cicatrização , Ferimentos e Lesões/terapia
3.
J Clin Biochem Nutr ; 74(1): 57-62, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38292119

RESUMO

Immune checkpoint therapy has been shown to be an effective therapy for many types of tumors. Much attention has been paid to the development of an effector target would be helpful for immune checkpoint therapy. Genistein has been shown to have an anti-tumor effect both in vitro and in vivo. In this study, we examined the effect of genistein on immune checkpoint blockade therapy against B16F1 melanoma tumors. Mice treated with genistein or anti-programmed death (PD)-1 antibody showed a significant decrease in tumor growth. However, treatment with genistein had no effect on or attenuated the efficacy of immune checkpoint therapy. The percentages of T cell receptor (TCR)ß+CD4+ and TCRß+CD8+ cells and the concentrations of interferon-γ and tumor necrosis factor-α in tumor tissue were not different among the experimental groups. A significant difference was also not found in microbe composition. Interestingly, a high expression level of PD-ligand (L)1 closely reflected the outcome of therapy by genistein or anti-PD-1 antibody. The study showed that a combination of genistein treatment does not improve the effect of immune blockade therapy. It also showed that a high PD-L1 expression level in tumors is a good prediction maker for the outcome of tumor therapy.

4.
Gastroenterology ; 160(6): 2089-2102.e12, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33577875

RESUMO

BACKGROUND & AIMS: Fecal microbiota transplantation (FMT) is an effective therapy for recurrent Clostridioides difficile infection (rCDI). However, the overall mechanisms underlying FMT success await comprehensive elucidation, and the safety of FMT has recently become a serious concern because of the occurrence of drug-resistant bacteremia transmitted by FMT. We investigated whether functional restoration of the bacteriomes and viromes by FMT could be an indicator of successful FMT. METHODS: The human intestinal bacteriomes and viromes from 9 patients with rCDI who had undergone successful FMT and their donors were analyzed. Prophage-based and CRISPR spacer-based host bacteria-phage associations in samples from recipients before and after FMT and in donor samples were examined. The gene functions of intestinal microorganisms affected by FMT were evaluated. RESULTS: Metagenomic sequencing of both the viromes and bacteriomes revealed that FMT does change the characteristics of intestinal bacteriomes and viromes in recipients after FMT compared with those before FMT. In particular, many Proteobacteria, the fecal abundance of which was high before FMT, were eliminated, and the proportion of Microviridae increased in recipients. Most temperate phages also behaved in parallel with the host bacteria that were altered by FMT. Furthermore, the identification of bacterial and viral gene functions before and after FMT revealed that some distinctive pathways, including fluorobenzoate degradation and secondary bile acid biosynthesis, were significantly represented. CONCLUSIONS: The coordinated action of phages and their host bacteria restored the recipients' intestinal flora. These findings show that the restoration of intestinal microflora functions reflects the success of FMT.


Assuntos
Enterocolite Pseudomembranosa/terapia , Transplante de Microbiota Fecal , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Viroma , Adulto , Idoso , Bacteriófagos , Clostridioides difficile , Enterocolite Pseudomembranosa/microbiologia , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/genética , Trato Gastrointestinal/virologia , Humanos , Masculino , Metagenômica , Microviridae , Pessoa de Meia-Idade , Proteobactérias , Viroma/genética
5.
Nature ; 540(7631): 144-149, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27851729

RESUMO

Targeted genome editing via engineered nucleases is an exciting area of biomedical research and holds potential for clinical applications. Despite rapid advances in the field, in vivo targeted transgene integration is still infeasible because current tools are inefficient, especially for non-dividing cells, which compose most adult tissues. This poses a barrier for uncovering fundamental biological principles and developing treatments for a broad range of genetic disorders. Based on clustered regularly interspaced short palindromic repeat/Cas9 (CRISPR/Cas9) technology, here we devise a homology-independent targeted integration (HITI) strategy, which allows for robust DNA knock-in in both dividing and non-dividing cells in vitro and, more importantly, in vivo (for example, in neurons of postnatal mammals). As a proof of concept of its therapeutic potential, we demonstrate the efficacy of HITI in improving visual function using a rat model of the retinal degeneration condition retinitis pigmentosa. The HITI method presented here establishes new avenues for basic research and targeted gene therapies.


Assuntos
Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Marcação de Genes/métodos , Genoma/genética , Retinose Pigmentar/genética , Retinose Pigmentar/terapia , Animais , Divisão Celular , Modelos Animais de Doenças , Técnicas de Introdução de Genes , Terapia Genética/métodos , Neurônios/citologia , Neurônios/metabolismo , Ratos , Homologia de Sequência
6.
Biosci Biotechnol Biochem ; 87(1): 90-98, 2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36352466

RESUMO

We have previously reported that the dipeptide Phe-Pro affects lipid metabolism in vivo and in vitro, but very little is known regarding the mechanism of action of Phe-Pro after it is absorbed by the intestines via PepT1. In this study, we administered a single oral dose of Phe-Pro to rats and quantified its concentration in the portal plasma using LC-TOF/MS analysis. Additionally, the physiological blood concentration of Phe-Pro was added to the lipid accumulation model of HepG2 cells to decrease intracellular cholesterol and increase the expression of CYP7A1 and PPARα mRNA levels. Moreover, we analyzed the binding of PPARα and Phe-Pro using AlphaFold2. We found that Phe-Pro is a ligand for PPARα. To the best of our knowledge, this is the first study that shows Phe-Pro to be present in the portal plasma. We found for the first time that Phe-Pro ameliorated cholesterol metabolism in HepG2 cells.


Assuntos
PPAR alfa , Fenilalanina , Ratos , Animais , Humanos , Células Hep G2 , PPAR alfa/metabolismo , Fenilalanina/farmacologia , Fenilalanina/metabolismo , Prolina/farmacologia , Prolina/metabolismo , Colesterol/metabolismo , Metabolismo dos Lipídeos
7.
Mol Ther ; 23(7): 1182-1188, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25896244

RESUMO

Fluorescence-guided surgery (FGS) of cancer is an area of intense current interest. However, although benefits have been demonstrated with FGS, curative strategies need to be developed. Glioblastoma multiforme (GBM) is one of the most invasive of cancers and is not totally resectable using standard bright-light surgery (BLS) or current FGS strategies. We report here a curative strategy for FGS of GBM. In this study, telomerase-dependent adenovirus OBP-401 infection brightly and selectively labeled GBM with green fluorescent protein (GFP) for FGS in orthotopic nude mouse models. OBP-401-based FGS enabled curative resection of GBM without recurrence for at least 150 days, compared to less than 30 days with BLS.


Assuntos
Fluorescência , Glioblastoma/cirurgia , Proteínas de Fluorescência Verde/uso terapêutico , Recidiva Local de Neoplasia/cirurgia , Adenoviridae , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Intervalo Livre de Doença , Glioblastoma/patologia , Proteínas de Fluorescência Verde/química , Humanos , Camundongos , Camundongos Nus , Recidiva Local de Neoplasia/patologia , Imagem Óptica
8.
J Cell Biochem ; 116(4): 661-6, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25418288

RESUMO

The response to DNA damage during mitosis was visualized using real-time fluorescence imaging of focus formation by the DNA-damage repair (DDR) response protein 53BP1 linked to green fluorescent protein (GFP) (53BP1-GFP) in the MiaPaCa-2(Tet-On) pancreatic cancer cell line. To observe 53BP1-GFP foci during mitosis, MiaPaCa-2(Tet-On) 53BP1-GFP cells were imaged every 30 min by confocal microscopy. Time-lapse imaging demonstrated that 11.4 ± 2.1% of the mitotic MiaPaCa-2(Tet-On) 53BP1-GFP cells had increased focus formation over time. Non-mitotic cells did not have an increase in 53BP1-GFP focus formation over time. Some of the mitotic MiaPaCa-2(Tet-On) 53BP1-GFP cells with focus formation became apoptotic. The results of the present report suggest that DNA strand breaks occur during mitosis and undergo repair, which may cause some of the mitotic cells to enter apoptosis in a phenomenon possibly related to mitotic catastrophe.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mitose , Imagem Óptica/métodos , Linhagem Celular Tumoral , Dano ao DNA , Reparo do DNA , Proteínas de Fluorescência Verde , Humanos , Microscopia Confocal , Imagem com Lapso de Tempo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53
9.
J Cell Biochem ; 115(9): 1490-4, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24590470

RESUMO

We previously described a color-coded imaging model that can quantify the length of nascent blood vessels using Gelfoam® implanted in nestin-driven green fluorescent protein (ND-GFP) nude mice. In ND-GFP mice, nascent blood vessels are labeled with GFP. We report here that osteosarcoma cells promote angiogenesis in the Gelfoam® angiogenesis assay in ND-GFP mice. Gelfoam® was initially transplanted subcutaneously in the flank of transgenic ND-GFP nude mice. Seven days after transplantation of Gelfoam®, skin flaps were made and human 143B osteosarcoma cells expressing green fluorescent protein (GFP) in the nucleus and red fluorescent protein (RFP) in cytoplasm were injected into the transplanted Gelfoam®. The control-group mice had only implanted Gelfoam®. Skin flaps were made at days 14, 21, and 28 after transplantation of the Gelfoam® to allow imaging of vascularization in the Gelfoam® using a variable-magnification small animal imaging system and confocal fluorescence microscopy. ND-GFP expressing nascent blood vessels penetrated and spread into the Gelfoam® in a time-dependent manner in both control and osteosarcoma-implanted mice. ND-GFP expressing blood vessels in the Gelfoam® of the osteosarcoma-implanted mice were associated with the cancer cells and larger and longer than in the Gelfoam®-only implanted mice (P < 0.01). The results presented in this report demonstrate strong angiogenesis induction by osteosarcoma cells and suggest this process is a potential therapeutic target for this disease.


Assuntos
Proteínas de Fluorescência Verde/biossíntese , Proteínas Luminescentes/biossíntese , Neovascularização Patológica/metabolismo , Osteossarcoma/irrigação sanguínea , Animais , Linhagem Celular Tumoral , Feminino , Esponja de Gelatina Absorvível , Proteínas de Fluorescência Verde/genética , Humanos , Implantes Experimentais , Proteínas Luminescentes/genética , Camundongos , Camundongos Nus , Camundongos Transgênicos , Microscopia Confocal , Transplante de Neoplasias , Proteína Vermelha Fluorescente
10.
J Cell Biochem ; 115(11): 1996-2003, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24924355

RESUMO

We report here the efficacy of tumor-targeting Salmonella typhimurium A1-R (A1-R) on mouse models of disseminated and metastatic ovarian cancer. The proliferation-inhibitory efficacy of A1-R on human ovarian cancer cell lines (SKOV-3-GFP, OVCAR-3-RFP) was initially demonstrated in vitro. Orthotopic and dissemination mouse models of ovarian cancer were made with the human ovarian cancer cell line SKOV-3-GFP. After tumor implantation, the mice were treated with A1-R (5 × 10(7) colony-forming units [CFU], i.v.), and there were no severe adverse events observed. In the orthotopic model, tumor volume after treatment was 276 ± 60.8 mm(3), compared to 930 ± 342 mm(3) in the untreated control group (P = 0.022). There was also a significant difference in survival between treated mice and untreated mice in a peritoneal dissemination model (P = 0.005). The results of this report demonstrate that A1-R is effective for highly aggressive human ovarian cancer in metastatic and dissemination mouse models and suggest its clinical potential for this highly treatment-resistant disease.


Assuntos
Neoplasias Ovarianas/terapia , Neoplasias Peritoneais/secundário , Neoplasias Peritoneais/terapia , Infecções por Salmonella/patologia , Salmonella typhimurium/patogenicidade , Animais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Camundongos , Camundongos Nus , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/patologia , Salmonella typhimurium/classificação , Análise de Sobrevida , Ensaios Antitumorais Modelo de Xenoenxerto
11.
J Cell Biochem ; 115(10): 1724-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24819034

RESUMO

We have previously demonstrated that ultraviolet (UV) light is effective against a variety of cancer cells expressing fluorescent proteins in vivo as well as in vitro. In the present report, we compared the DNA damage repair (DDR) response of pancreatic cancer cells after UVB or UVC irradiation. The UV-induced DNA damage repair was imaged with green fluorescent protein (GFP) fused to the DDR-related chromatin-binding protein 53BP1 in MiaPaCa-2 human pancreatic cancer cells growing in 3D Gelfoam® histoculture and in superficial tumors grown in nude mice. 53BP1-GFP forms foci during DNA damage repair. A clonogenic assay in 2D monolayer culture initially showed that UVC and UVB inhibited MiaPaCa-2 cell proliferation in a dose-dependent manner, with UVC having more efficacy. Three-dimensional Gelfoam® histocultures and confocal imaging enabled 53BP1-GFP foci to be observed within 1 h after UV irradiation, indicating the onset of DDR response. UVB-induced 53BP1-GFP focus formation was observed up to a depth of 120 µm in MiaPaCa-2 cells on Gelfoam® compared to 80 µm for UVC. UVB-induced 53BP1-GFP focus formation was observed up to a depth of 80 µm in MiaPaCa-2 cells, implanted within skin flaps in mice, at a significantly greater extent than UVC. MiaPaCa-2 cells irradiated by UVB or UVC in the skin-flap mouse model had a significant decrease in tumor growth compared to untreated controls with UVB having more efficacy than UVC. Our results demonstrate that UVB has greater tissue penetration than UVC because of its longer wavelength and has clinical potential for eradicating superficial cancer.


Assuntos
Dano ao DNA/efeitos da radiação , Reparo do DNA/efeitos da radiação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pancreáticas/radioterapia , Terapia Ultravioleta/métodos , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Dano ao DNA/genética , Reparo do DNA/genética , Relação Dose-Resposta à Radiação , Proteínas de Fluorescência Verde/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/efeitos da radiação , Camundongos , Camundongos Nus , Camundongos Transgênicos , Transplante de Neoplasias , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Transplante Heterólogo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53 , Raios Ultravioleta
12.
J Surg Res ; 192(1): 124-33, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24972740

RESUMO

BACKGROUND: The aim of this study is to investigate the effectiveness of fluorescence-guided surgery (FGS) of prostate cancer experimental skeletal metastasis. MATERIALS AND METHODS: Green fluorescent protein-expressing PC-3 human prostate cancer cells (PC-3-green fluorescent protein) were injected into the intramedullary cavity of the tibia in 32 nude mice. After 2 wk, 16 of the mice underwent FGS; the other 16 mice underwent bright-light surgery (BLS). Half of BLS and FGS mice (8 mice in each group) received zoledronic acid (ZOL). Weekly fluorescence imaging of the mice was performed. Six weeks after surgery, metastases to lung and inguinal lymph node were evaluated by fluorescence imaging. RESULTS: The percentage of residual tumor after BLS and FGS was 9.9 ± 2.2% and 0.9 ± 0.3%, respectively (P < 0.001). FGS reduced recurrent cancer growth compared with BLS (P < 0.005). Although FGS alone had no significant effect on inguinal lymph node metastases, lung metastasis or disease-free survival (DFS), ZOL in combination with FGS significantly increased DFS (P = 0.01) in comparison with the combination of BLS and ZOL. ZOL reduced lymph node metastases (P = 0.033) but not lung metastasis. CONCLUSIONS: FGS significantly reduced recurrence of experimental prostate cancer bone metastasis compared with BLS. The combination of FGS and ZOL increased DFS over BLS and ZOL. ZOL inhibited lymph node metastasis but not lung metastasis.


Assuntos
Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Neoplasias Ósseas/secundário , Neoplasias Ósseas/cirurgia , Neoplasia Residual/prevenção & controle , Neoplasias da Próstata/patologia , Animais , Conservadores da Densidade Óssea/farmacologia , Linhagem Celular Tumoral , Difosfonatos/farmacologia , Modelos Animais de Doenças , Intervalo Livre de Doença , Proteínas de Fluorescência Verde/genética , Humanos , Imidazóis/farmacologia , Proteínas Luminescentes/genética , Metástase Linfática , Masculino , Camundongos Nus , Recidiva Local de Neoplasia/prevenção & controle , Recidiva Local de Neoplasia/cirurgia , Neoplasia Residual/cirurgia , Imagem Óptica/métodos , Ácido Zoledrônico , Proteína Vermelha Fluorescente
13.
Cell Rep Med ; 5(3): 101449, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38508141

RESUMO

Tissue regeneration following an injury requires dynamic cell-state transitions that allow for establishing the cell identities required for the restoration of tissue homeostasis and function. Here, we present a biochemical intervention that induces an intermediate cell state mirroring a transition identified during normal differentiation of myoblasts and other multipotent and pluripotent cells to mature cells. When applied in somatic differentiated cells, the intervention, composed of one-carbon metabolites, reduces some dedifferentiation markers without losing the lineage identity, thus inducing limited reprogramming into a more flexible cell state. Moreover, the intervention enabled accelerated repair after muscle injury in young and aged mice. Overall, our study uncovers a conserved biochemical transitional phase that enhances cellular plasticity in vivo and hints at potential and scalable biochemical interventions of use in regenerative medicine and rejuvenation interventions that may be more tractable than genetic ones.


Assuntos
Músculos , Mioblastos , Camundongos , Animais , Diferenciação Celular , Mioblastos/metabolismo
14.
Sci Transl Med ; 14(657): eabl6057, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35947677

RESUMO

Constitutive heterochromatin is responsible for genome repression of DNA enriched in repetitive sequences, telomeres, and centromeres. During physiological and pathological premature aging, heterochromatin homeostasis is profoundly compromised. Here, we showed that LINE-1 (Long Interspersed Nuclear Element-1; L1) RNA accumulation was an early event in both typical and atypical human progeroid syndromes. L1 RNA negatively regulated the enzymatic activity of the histone-lysine N-methyltransferase SUV39H1 (suppression of variegation 3-9 homolog 1), resulting in heterochromatin loss and onset of senescent phenotypes in vitro. Depletion of L1 RNA in dermal fibroblast cells from patients with different progeroid syndromes using specific antisense oligonucleotides (ASOs) restored heterochromatin histone 3 lysine 9 and histone 3 lysine 27 trimethylation marks, reversed DNA methylation age, and counteracted the expression of senescence-associated secretory phenotype genes such as p16, p21, activating transcription factor 3 (ATF3), matrix metallopeptidase 13 (MMP13), interleukin 1a (IL1a), BTG anti-proliferation factor 2 (BTG2), and growth arrest and DNA damage inducible beta (GADD45b). Moreover, systemic delivery of ASOs rescued the histophysiology of tissues and increased the life span of a Hutchinson-Gilford progeria syndrome mouse model. Transcriptional profiling of human and mouse samples after L1 RNA depletion demonstrated that pathways associated with nuclear chromatin organization, cell proliferation, and transcription regulation were enriched. Similarly, pathways associated with aging, inflammatory response, innate immune response, and DNA damage were down-regulated. Our results highlight the role of L1 RNA in heterochromatin homeostasis in progeroid syndromes and identify a possible therapeutic approach to treat premature aging and related syndromes.


Assuntos
Senilidade Prematura , Síndrome de Cockayne , Proteínas Imediatamente Precoces , Progéria , Senilidade Prematura/genética , Animais , Antígenos de Diferenciação , Heterocromatina , Histonas/metabolismo , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Elementos Nucleotídeos Longos e Dispersos , Lisina/metabolismo , Camundongos , Fenótipo , Progéria/genética , RNA , Telômero/genética , Proteínas Supressoras de Tumor/genética
15.
Cell Rep ; 39(4): 110730, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35476977

RESUMO

Mammals have limited regenerative capacity, whereas some vertebrates, like fish and salamanders, are able to regenerate their organs efficiently. The regeneration in these species depends on cell dedifferentiation followed by proliferation. We generate a mouse model that enables the inducible expression of the four Yamanaka factors (Oct-3/4, Sox2, Klf4, and c-Myc, or 4F) specifically in hepatocytes. Transient in vivo 4F expression induces partial reprogramming of adult hepatocytes to a progenitor state and concomitantly increases cell proliferation. This is indicated by reduced expression of differentiated hepatic-lineage markers, an increase in markers of proliferation and chromatin modifiers, global changes in DNA accessibility, and an acquisition of liver stem and progenitor cell markers. Functionally, short-term expression of 4F enhances liver regenerative capacity through topoisomerase2-mediated partial reprogramming. Our results reveal that liver-specific 4F expression in vivo induces cellular plasticity and counteracts liver failure, suggesting that partial reprogramming may represent an avenue for enhancing tissue regeneration.


Assuntos
Reprogramação Celular , Fígado , Animais , Desdiferenciação Celular , Hepatócitos/metabolismo , Fígado/metabolismo , Regeneração Hepática , Mamíferos , Camundongos
16.
Nat Aging ; 2(3): 243-253, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-37118377

RESUMO

Partial reprogramming by expression of reprogramming factors (Oct4, Sox2, Klf4 and c-Myc) for short periods of time restores a youthful epigenetic signature to aging cells and extends the life span of a premature aging mouse model. However, the effects of longer-term partial reprogramming in physiologically aging wild-type mice are unknown. Here, we performed various long-term partial reprogramming regimens, including different onset timings, during physiological aging. Long-term partial reprogramming lead to rejuvenating effects in different tissues, such as the kidney and skin, and at the organismal level; duration of the treatment determined the extent of the beneficial effects. The rejuvenating effects were associated with a reversion of the epigenetic clock and metabolic and transcriptomic changes, including reduced expression of genes involved in the inflammation, senescence and stress response pathways. Overall, our observations indicate that partial reprogramming protocols can be designed to be safe and effective in preventing age-related physiological changes. We further conclude that longer-term partial reprogramming regimens are more effective in delaying aging phenotypes than short-term reprogramming.


Assuntos
Senilidade Prematura , Reprogramação Celular , Animais , Camundongos , Reprogramação Celular/genética , Envelhecimento/genética , Senescência Celular , Senilidade Prematura/genética , Modelos Animais de Doenças
17.
Biomacromolecules ; 12(11): 3982-8, 2011 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-21928815

RESUMO

Three holocelluloses (i.e., cellulose and hemicellulose fractions) are prepared from softwood and hardwood by the Wise method. These holocelluloses completely dissolve in 8% lithium chloride/1,3-dimethyl-2-imidazolidinone (LiCl/DMI) after an ethylenediamine (EDA) pretreatment. After diluting the holocellulose solutions to 1% LiCl/DMI, they are subjected to size-exclusion chromatography/multiangle laser-light scattering/photodiode array (SEC-MALLS-PDA) analysis. All holocelluloses exhibit bimodal molecular weight distributions primarily due to high-molecular-weight (HMW) cellulose and low-molecular-weight hemicellulose fractions. Plots of molecular weight vs root-mean-square radius obtained by SEC-MALLS analysis revealed that all the wood celluloses comprise dense conformations in 1% LiCl/DMI. In contrast, bacterial cellulose, which was used as a pure cellulose model, has a random coil conformation as a linear polymer. These results show that both softwood and hardwood HMW celluloses contain branched structures, which are probably present on crystalline cellulose microfibril surfaces. These results are consistent with those obtained by permethylation analysis of wood celluloses.


Assuntos
Celulose/química , Cloreto de Lítio/química , Solventes/química , Madeira/química , Configuração de Carboidratos , Carboidratos/química , Celulose/ultraestrutura , Cryptomeria/química , Etilenodiaminas/química , Eucalyptus/química , Fagus/química , Imidazolidinas/química , Lasers , Luz , Peso Molecular , Espalhamento de Radiação , Madeira/ultraestrutura , Difração de Raios X
18.
BMC Dev Biol ; 10: 84, 2010 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-20691046

RESUMO

BACKGROUND: Developmental angiogenesis proceeds through multiple morphogenetic events including sprouting, intussusception, and pruning. Mice lacking the membrane-anchored metalloproteinase regulator Reck die in utero around embryonic day 10.5 with halted vascular development; however, the mechanisms by which this phenotype arises remain unclear. RESULTS: We found that Reck is abundantly expressed in the cells associated with blood vessels undergoing angiogenesis or remodelling in the uteri of pregnant female mice. Some of the Reck-positive vessels show morphological features consistent with non-sprouting angiogenesis. Treatment with a vector expressing a small hairpin RNA against Reck severely disrupts the formation of blood vessels with a compact, round lumen. Similar defects were found in the vasculature of Reck-deficient or Reck conditional knockout embryos. CONCLUSIONS: Our findings implicate Reck in vascular remodeling, possibly through non-sprouting angiogenesis, in both maternal and embyonic tissues.


Assuntos
Embrião de Mamíferos/irrigação sanguínea , Glicoproteínas de Membrana/metabolismo , Neovascularização Fisiológica , Útero/irrigação sanguínea , Animais , Vasos Sanguíneos/metabolismo , Implantação do Embrião , Feminino , Proteínas Ligadas por GPI , Camundongos , Gravidez
19.
J Neurochem ; 115(2): 385-98, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20796170

RESUMO

The extracellular matrix (ECM) is important for both structural integrity and functions of the brain. Matrix metalloproteinases (MMPs) play major roles in ECM-remodeling under both physiological and pathological conditions. Reversion-inducing cysteine-rich protein with Kazal motifs (Reck) is a membrane-anchored MMP-regulator implicated in coordinated regulation of pericellular proteolysis. Although patho-physiological importance of MMPs and another group of MMP-regulators, tissue inhibitor of metalloproteinases, in brain ischemia has been demonstrated, little is known about the role of Reck in this process. In this study, we found that Reck is up-regulated in hippocampus and penumbra of subventricular zone after transient cerebral ischemia in mice. Most of the Reck-positive cells found at day 2 after ischemia are positive for Nestin as well as Ki67 and localized to the CA2 region of the hippocampus. At day 7 after ischemia, the Reck-positive cells increased in number, extended processes, expressed the reactive astrocyte marker GFAP and the neuronal marker NF200, and were widely distributed in the hippocampus. In the mutant mice carrying single functional Reck allele (Reck+/-), tissue damage and cell death after cerebral ischemia were augmented, the recovery of long-term potentiation in the hippocampus was compromised, NR2C subunit of NMDA receptor was up-regulated, gelatinolytic activity of MMPs were up-regulated and laminin-immunoreactivity was reduced. Our data implicate Reck in protection of ECM/tissue integrity and promotion of functional recovery in the brain after transient cerebral ischemia.


Assuntos
Ataque Isquêmico Transitório/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima/fisiologia , Animais , Biofísica , Contagem de Células/métodos , Modelos Animais de Doenças , Estimulação Elétrica , Hipocampo/metabolismo , Hipocampo/patologia , Marcação In Situ das Extremidades Cortadas/métodos , Técnicas In Vitro , Ataque Isquêmico Transitório/genética , Ataque Isquêmico Transitório/patologia , Antígeno Ki-67/metabolismo , Laminas/metabolismo , Potenciação de Longa Duração/genética , Potenciação de Longa Duração/fisiologia , Masculino , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Técnicas de Patch-Clamp , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , RNA Mensageiro/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Recuperação de Função Fisiológica/genética , Proteínas Supressoras de Tumor/deficiência , Proteínas Supressoras de Tumor/genética
20.
Oncol Rep ; 22(3): 615-20, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19639212

RESUMO

We investigated the effects of a water-soluble extract of Maitake (Grifola frondosa), a Japanese edible mushroom, on the proliferation and cell death of four human gastric cancer cell lines (TMK-1, MKN28, MKN45 and MKN74). The Maitake extract (ME) inhibited the proliferation of all four cell lines in a time-dependent manner. The inhibition was most pronounced in TMK-1 cells, which exhibited up to 90% inhibition after treatment with 10% ME for 3 days. Staining of ME-treated TMK-1 cells with Hoechst 33258 revealed increased numbers of nuclear condensations and apoptotic bodies. Induction of apoptosis was confirmed by fluorescence-activated cell sorting analyses. Western blot analyses of TMK-1 cells after ME treatment revealed increases in intracytoplasmic cytochrome c and cleavage of caspase-3 and poly(ADP-ribose) polymerase, but no expression of p21 or Bax. The caspase-3 protease activities in lysates of TMK-1 cells treated with 1% or 10% ME were about three times higher than those in control cells. The proliferation of TMK-1 cells was hardly affected by the caspase-3 inhibitor z-DEVD-fmk. Taken together, these results suggest that ME induces apoptosis of TMK-1 cells by caspase-3-dependent and -independent pathways, resulting in potential antitumor effects on gastric cancer.


Assuntos
Antineoplásicos/farmacologia , Grifola , Neoplasias Gástricas/tratamento farmacológico , Apoptose/efeitos dos fármacos , Caspase 3/fisiologia , Linhagem Celular Tumoral , Citocromos c/metabolismo , Humanos , Neoplasias Gástricas/patologia
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