Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20.351
Filtrar
1.
Nat Commun ; 12(1): 4810, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376666

RESUMO

The R2TP chaperone cooperates with HSP90 to integrate newly synthesized proteins into multi-subunit complexes, yet its role in tissue homeostasis is unknown. Here, we generated conditional, inducible knock-out mice for Rpap3 to inactivate this core component of R2TP in the intestinal epithelium. In adult mice, Rpap3 invalidation caused destruction of the small intestinal epithelium and death within 10 days. Levels of R2TP substrates decreased, with strong effects on mTOR, ATM and ATR. Proliferative stem cells and progenitors deficient for Rpap3 failed to import RNA polymerase II into the nucleus and they induced p53, cell cycle arrest and apoptosis. Post-mitotic, differentiated cells did not display these alterations, suggesting that R2TP clients are preferentially built in actively proliferating cells. In addition, high RPAP3 levels in colorectal tumors from patients correlate with bad prognosis. Here, we show that, in the intestine, the R2TP chaperone plays essential roles in normal and tumoral proliferation.


Assuntos
Proliferação de Células , Células Epiteliais/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Mucosa Intestinal/metabolismo , Chaperonas Moleculares/metabolismo , Animais , Células Cultivadas , Células Epiteliais/citologia , Humanos , Mucosa Intestinal/citologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microscopia Confocal , Ligação Proteica , Células-Tronco/citologia , Células-Tronco/metabolismo
2.
Nat Biomed Eng ; 5(8): 847-863, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34385693

RESUMO

The therapeutic efficacy of stem cells transplanted into an ischaemic brain depends primarily on the responses of the neurovascular unit. Here, we report the development and applicability of a functional neurovascular unit on a microfluidic chip as a microphysiological model of ischaemic stroke that recapitulates the function of the blood-brain barrier as well as interactions between therapeutic stem cells and host cells (human brain microvascular endothelial cells, pericytes, astrocytes, microglia and neurons). We used the model to track the infiltration of a number of candidate stem cells and to characterize the expression levels of genes associated with post-stroke pathologies. We observed that each type of stem cell showed unique neurorestorative effects, primarily by supporting endogenous recovery rather than through direct cell replacement, and that the recovery of synaptic activities is correlated with the recovery of the structural and functional integrity of the neurovascular unit rather than with the regeneration of neurons.


Assuntos
AVC Isquêmico/terapia , Dispositivos Lab-On-A-Chip , Transplante de Células-Tronco , Astrócitos/citologia , Astrócitos/metabolismo , Barreira Hematoencefálica/química , Barreira Hematoencefálica/metabolismo , Técnicas de Cocultura , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Humanos , Microglia/citologia , Microglia/metabolismo , Microvasos/citologia , Modelos Biológicos , Neurônios/citologia , Neurônios/metabolismo , Pericitos/citologia , Pericitos/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo
3.
J Immunol ; 207(4): 1078-1086, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34341172

RESUMO

Emergency granulopoiesis, also known as demand-adapted granulopoiesis, is defined as the response of an organism to systemic bacterial infections, and it results in neutrophil mobilization from reservoir pools and increased myelopoiesis in the bone marrow. Indirect and direct initiating mechanisms of emergency granulopoiesis have been hypothesized. However, the detailed mechanism of hyperactive myelopoiesis in the bone marrow, which leads to granulocyte left shift, remains unknown. In this study, we report that TLR4 is expressed on granulo-monocytic progenitors, as well as mobilized human peripheral blood CD34+ cells, which account for 0.2% of monocytes in peripheral blood, and ∼ 10% in bone marrow. LPS, a component of Gram-negative bacteria that results in a systemic bacterial infection, induces the differentiation of peripheral blood CD34+ cells into myelocytes and monocytes in vitro via the TLR4 signaling pathway. Moreover, CD34+ cells directly responded to LPS stimulation by activating the MAPK and NF-κB signaling pathways, and they produced IL-6 that promotes emergency granulopoiesis by phosphorylating C/EBPα and C/EBPß, and this effect was suppressed by the action of an IL-6 receptor inhibitor. This work supports the finding that TLR is expressed on human hematopoietic stem and progenitor cells, and it provides evidence that human hematopoietic stem and progenitor cells can directly sense pathogens and produce cytokines exerting autocrine and/or paracrine effects, thereby promoting differentiation.


Assuntos
Granulócitos/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Interleucina-6/metabolismo , Transdução de Sinais/fisiologia , Células-Tronco/metabolismo , Receptor 4 Toll-Like/metabolismo , Adaptação Fisiológica/fisiologia , Antígenos CD34/metabolismo , Medula Óssea/metabolismo , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Diferenciação Celular/fisiologia , Citocinas/metabolismo , Regulação da Expressão Gênica/fisiologia , Células Precursoras de Granulócitos/metabolismo , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Monócitos/metabolismo , Mielopoese/fisiologia
4.
FASEB J ; 35(9): e21816, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34396583

RESUMO

Proper physiological function of mammalian airways requires the differentiation of basal stem cells into secretory or multiciliated cells, among others. In addition, the self-renewal ability of these basal stem cells is crucial for developing a quick response to toxic agents in order to re-establish the epithelial barrier function of the airways. Although these epithelial missions are vital, little is known about those mechanism controlling airway epithelial regeneration in health and disease. p53 has been recently proposed as the guardian of homeostasis, promoting differentiation programs, and antagonizing a de-differentiation program. Here, we exploit mouse and human tracheal epithelial cell culture models to study the role of MDM2-p53 signaling in self-renewal and differentiation in the airway epithelium. We show that p53 protein regulation by MDM2 is crucial for basal stem cell differentiation and to keep proper cell proliferation. Therefore, we suggest that MDM2/p53 interaction modulation is a potential target to control regeneration of the mammalian airway epithelia without massively affecting the epithelium integrity and differentiation potential.


Assuntos
Diferenciação Celular/fisiologia , Epitélio/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Mucosa Respiratória/metabolismo , Células-Tronco/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Proliferação de Células/fisiologia , Células Epiteliais/metabolismo , Feminino , Homeostase/fisiologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Regeneração/fisiologia , Transdução de Sinais/fisiologia , Traqueia/metabolismo
5.
Biomolecules ; 11(7)2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34356611

RESUMO

Glaucoma is a group of irreversible blinding eye diseases characterized by the progressive loss of retinal ganglion cells (RGCs) and their axons. Currently, there is no effective method to fundamentally resolve the issue of RGC degeneration. Recent advances have revealed that visual function recovery could be achieved with stem cell-based therapy by replacing damaged RGCs with cell transplantation, providing nutritional factors for damaged RGCs, and supplying healthy mitochondria and other cellular components to exert neuroprotective effects and mediate transdifferentiation of autologous retinal stem cells to accomplish endogenous regeneration of RGC. This article reviews the recent research progress in the above-mentioned fields, including the breakthroughs in the fields of in vivo transdifferentiation of retinal endogenous stem cells and reversal of the RGC aging phenotype, and discusses the obstacles in the clinical translation of the stem cell therapy.


Assuntos
Glaucoma , Regeneração , Células Ganglionares da Retina/fisiologia , Transplante de Células-Tronco , Células-Tronco/metabolismo , Animais , Glaucoma/metabolismo , Glaucoma/patologia , Glaucoma/terapia , Humanos , Células-Tronco/patologia
6.
Nat Commun ; 12(1): 4939, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34400627

RESUMO

Pain is a central feature of soft tissue trauma, which under certain contexts, results in aberrant osteochondral differentiation of tissue-specific stem cells. Here, the role of sensory nerve fibers in this abnormal cell fate decision is investigated using a severe extremity injury model in mice. Soft tissue trauma results in NGF (Nerve growth factor) expression, particularly within perivascular cell types. Consequently, NGF-responsive axonal invasion occurs which precedes osteocartilaginous differentiation. Surgical denervation impedes axonal ingrowth, with significant delays in cartilage and bone formation. Likewise, either deletion of Ngf or two complementary methods to inhibit its receptor TrkA (Tropomyosin receptor kinase A) lead to similar delays in axonal invasion and osteochondral differentiation. Mechanistically, single-cell sequencing suggests a shift from TGFß to FGF signaling activation among pre-chondrogenic cells after denervation. Finally, analysis of human pathologic specimens and databases confirms the relevance of NGF-TrkA signaling in human disease. In sum, NGF-mediated TrkA-expressing axonal ingrowth drives abnormal osteochondral differentiation after soft tissue trauma. NGF-TrkA signaling inhibition may have dual therapeutic use in soft tissue trauma, both as an analgesic and negative regulator of aberrant stem cell differentiation.


Assuntos
Diferenciação Celular , Fator de Crescimento Neural/metabolismo , Receptor trkA/metabolismo , Transdução de Sinais , Ferimentos e Lesões/metabolismo , Animais , Axônios/metabolismo , Cartilagem/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator de Crescimento Neural/genética , Osteogênese , Células-Tronco/metabolismo , Ferimentos e Lesões/patologia
7.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360705

RESUMO

Human adipose-derived stem cells (hADSCs) are types of mesenchymal stem cells (MSCs) that have been used as tissue engineering models for bone, cartilage, muscle, marrow stroma, tendon, fat and other connective tissues. Tissue regeneration materials composed of hADSCs have the potential to play an important role in reconstituting damaged tissue or diseased mesenchymal tissue. In this study, we assessed and investigated the osteogenesis of hADSCs in both two-dimensional (2D) and three-dimensional (3D) culture conditions. We confirmed that the hADSCs successfully differentiated into bone tissues by ARS staining and quantitative RT-PCR. To gain insight into the detailed biological difference between the two culture conditions, we profiled the overall gene expression by analyzing the whole transcriptome sequencing data using various bioinformatic methods. We profiled the overall gene expression through RNA-Seq and further analyzed this using various bioinformatic methods. During differential gene expression testing, significant differences in the gene expressions between hADSCs cultured in 2D and 3D conditions were observed. The genes related to skeletal development, bone development and bone remodeling processes were overexpressed in the 3D culture condition as compared to the 2D culture condition. In summary, our RNA-Seq-based study proves effective in providing new insights that contribute toward achieving a genome-wide understanding of gene regulation in mesenchymal stem cell osteogenic differentiation and bone tissue regeneration within the 3D culture system.


Assuntos
Tecido Adiposo/metabolismo , Técnicas de Cultura de Células , Osteogênese , RNA-Seq , Células-Tronco/metabolismo , Tecido Adiposo/citologia , Humanos , Células-Tronco/citologia
8.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360711

RESUMO

The acute demise of stem cells following transplantation significantly compromises the efficacy of stem cell-based cell therapeutics for infarcted hearts. As the stem cells transplanted into the damaged heart are readily exposed to the hostile environment, it can be assumed that the acute death of the transplanted stem cells is also inflicted by the same environmental cues that caused massive death of the host cardiac cells. Pyroptosis, a highly inflammatory form of programmed cell death, has been added to the list of important cell death mechanisms in the damaged heart. However, unlike the well-established cell death mechanisms such as necrosis or apoptosis, the exact role and significance of pyroptosis in the acute death of transplanted stem cells have not been explored in depth. In the present study, we found that M1 macrophages mediate the pyroptosis in the ischemia/reperfusion (I/R) injured hearts and identified miRNA-762 as an important regulator of interleukin 1ß production and subsequent pyroptosis. Delivery of exogenous miRNA-762 prior to transplantation significantly increased the post-transplant survival of stem cells and also significantly ameliorated cardiac fibrosis and heart functions following I/R injury. Our data strongly suggest that suppressing pyroptosis can be an effective adjuvant strategy to enhance the efficacy of stem cell-based therapeutics for diseased hearts.


Assuntos
MicroRNAs , Traumatismo por Reperfusão Miocárdica , Piroptose , Transplante de Células-Tronco , Células-Tronco , Animais , Humanos , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , MicroRNAs/genética , MicroRNAs/farmacologia , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/terapia , Piroptose/efeitos dos fármacos , Piroptose/genética , Células RAW 264.7 , Ratos , Ratos Sprague-Dawley , Células-Tronco/metabolismo , Células-Tronco/patologia
9.
Stem Cell Res Ther ; 12(1): 452, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34380561

RESUMO

Mitophagy is a specific autophagic phenomenon in which damaged or redundant mitochondria are selectively cleared by autophagic lysosomes. A decrease in mitophagy can accelerate the aging process. Mitophagy is related to health and longevity and is the key to protecting stem cells from metabolic stress damage. Mitophagy decreases the metabolic level of stem cells by clearing active mitochondria, so mitophagy is becoming increasingly necessary to maintain the regenerative capacity of old stem cells. Stem cell senescence is the core problem of tissue aging, and tissue aging occurs not only in stem cells but also in transport amplifying cell chambers and the stem cell environment. The loss of the autophagic ability of stem cells can cause the accumulation of mitochondria and the activation of the metabolic state as well as damage the self-renewal ability and regeneration potential of stem cells. However, the claim remains controversial. Mitophagy is an important survival strategy against nutrient deficiency and starvation, and mitochondrial function and integrity may affect the viability, proliferation and differentiation potential, and longevity of normal stem cells. Mitophagy can affect the health and longevity of the human body, so the number of studies in this field has increased, but the mechanism by which mitophagy participates in stem cell development is still not fully understood. This review describes the potential significance of mitophagy in stem cell developmental processes, such as self-renewal, differentiation and aging. Through this work, we discovered the role and mechanism of mitophagy in different types of stem cells, identified novel targets for killing cancer stem cells and curing cancer, and provided new insights for future research in this field.


Assuntos
Mitocôndrias , Mitofagia , Autofagia , Humanos , Lisossomos/metabolismo , Células-Tronco/metabolismo
10.
Nat Commun ; 12(1): 5006, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34408135

RESUMO

Obesity is a strong risk factor for cancer progression, posing obesity-related cancer as one of the leading causes of death. Nevertheless, the molecular mechanisms that endow cancer cells with metastatic properties in patients affected by obesity remain unexplored.Here, we show that IL-6 and HGF, secreted by tumor neighboring visceral adipose stromal cells (V-ASCs), expand the metastatic colorectal (CR) cancer cell compartment (CD44v6 + ), which in turn secretes neurotrophins such as NGF and NT-3, and recruits adipose stem cells within tumor mass. Visceral adipose-derived factors promote vasculogenesis and the onset of metastatic dissemination by activation of STAT3, which inhibits miR-200a and enhances ZEB2 expression, effectively reprogramming CRC cells into a highly metastatic phenotype. Notably, obesity-associated tumor microenvironment provokes a transition in the transcriptomic expression profile of cells derived from the epithelial consensus molecular subtype (CMS2) CRC patients towards a mesenchymal subtype (CMS4). STAT3 pathway inhibition reduces ZEB2 expression and abrogates the metastatic growth sustained by adipose-released proteins. Together, our data suggest that targeting adipose factors in colorectal cancer patients with obesity may represent a therapeutic strategy for preventing metastatic disease.


Assuntos
Tecido Adiposo/citologia , Reprogramação Celular , Neoplasias do Colo/fisiopatologia , Células-Tronco Neoplásicas/citologia , Nicho de Células-Tronco , Tecido Adiposo/metabolismo , Animais , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Fator de Crescimento de Hepatócito/genética , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos SCID , MicroRNAs/genética , MicroRNAs/metabolismo , Metástase Neoplásica , Células-Tronco/citologia , Células-Tronco/metabolismo , Homeobox 2 de Ligação a E-box com Dedos de Zinco/genética , Homeobox 2 de Ligação a E-box com Dedos de Zinco/metabolismo
11.
In Vivo ; 35(5): 2589-2597, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34410946

RESUMO

BACKGROUND/AIM: Dermal papilla cells (DPCs) regulate hair follicle development. We aimed to investigate the effect of scoparone from Dendrobium densiflorum on DPCs in the induction of stem cell properties and pluripotency-related proteins. MATERIALS AND METHODS: DPC viability was evaluated by the MTT assay. Apoptosis or necrosis of DPCs was determined by Hoecsht33342/PI nuclear staining analysis. Expression of OCT4, NANOG and SOX2 genes was determined using Real-Time Polymerase Chain Reaction (PCR). Immunocytochemistry and western blot analysis were performed to determine pluripotency related proteins. RESULTS: Scoparone increased the expression of pluripotency related transcription factors SOX2 and NANOG, while it had minimal effects on OCT4 levels. Scoparone exerted its stemness-enhancing activity through the up-regulation of Akt-dependent inhibition of GSK3ß, resulting in increased cellular levels of ß-catenin. CONCLUSION: Our results show a potential novel activity and mechanism of action of scoparone on human DPCs that could facilitate the development of hair enrichment approaches.


Assuntos
Cumarínicos , Células-Tronco , Apoptose , Folículo Piloso , Humanos , Proteína Homeobox Nanog/genética , Proteína Homeobox Nanog/metabolismo , Fatores de Transcrição SOXB1/genética , Células-Tronco/metabolismo , Regulação para Cima
12.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34445548

RESUMO

S100A9, a Ca2+-binding protein, is tightly associated to neutrophil pro-inflammatory functions when forming a heterodimer with its S100A8 partner. Upon secretion into the extracellular environment, these proteins behave like damage-associated molecular pattern molecules, which actively participate in the amplification of the inflammation process by recruitment and activation of pro-inflammatory cells. Intracellular functions have also been attributed to the S100A8/A9 complex, notably its ability to regulate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation. However, the complete functional spectrum of S100A8/A9 at the intracellular level is far from being understood. In this context, we here investigated the possibility that the absence of intracellular S100A8/A9 is involved in cytokine secretion. To overcome the difficulty of genetically modifying neutrophils, we used murine neutrophils derived from wild-type and S100A9-/- Hoxb8 immortalized myeloid progenitors. After confirming that differentiated Hoxb8 neutrophil-like cells are a suitable model to study neutrophil functions, our data show that absence of S100A8/A9 led to a dysregulation of cytokine secretion after lipopolysaccharide (LPS) stimulation. Furthermore, we demonstrate that S100A8/A9-induced cytokine secretion was regulated by the nuclear factor kappa B (NF-κB) pathway. These results were confirmed in human differentiated HL-60 cells, in which S100A9 was inhibited by shRNAs. Finally, our results indicate that the degranulation process could be involved in the regulation of cytokine secretion by S100A8/A9.


Assuntos
Calgranulina A/metabolismo , Calgranulina B/metabolismo , Citocinas/metabolismo , Proteínas de Homeodomínio/metabolismo , Neutrófilos/imunologia , Células-Tronco/imunologia , Animais , Calgranulina A/genética , Calgranulina B/genética , Estrogênios/farmacologia , Células HL-60 , Proteínas de Homeodomínio/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas de Neoplasias , Neutrófilos/citologia , Neutrófilos/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo
13.
Int J Mol Sci ; 22(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34445573

RESUMO

Concentrated Growth Factors (CGF) represent new autologous (blood-derived biomaterial), attracting growing interest in the field of regenerative medicine. In this study, the chemical, structural, and biological characterization of CGF was carried out. CGF molecular characterization was performed by GC/MS to quantify small metabolites and by ELISA to measure growth factors and matrix metalloproteinases (MMPs) release; structural CGF characterization was carried out by SEM analysis and immunohistochemistry; CGF has been cultured, and its primary cells were isolated for the identification of their surface markers by flow cytometry, Western blot, and real-time PCR; finally, the osteogenic differentiation of CGF primary cells was evaluated through matrix mineralization by alizarin red staining and through mRNA quantification of osteogenic differentiation markers by real-time PCR. We found that CGF has a complex inner structure capable of influencing the release of growth factors, metabolites, and cells. These cells, which could regulate the production and release of the CGF growth factors, show stem features and are able to differentiate into osteoblasts producing a mineralized matrix. These data, taken together, highlight interesting new perspectives for the use of CGF in regenerative medicine.


Assuntos
Diferenciação Celular , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Osteoblastos/citologia , Osteogênese , Células-Tronco/citologia , Proliferação de Células , Células Cultivadas , Feminino , Humanos , Masculino , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo
14.
Nat Commun ; 12(1): 5043, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413292

RESUMO

Skeletal muscle has a remarkable ability to regenerate owing to its resident stem cells (also called satellite cells, SCs). SCs are normally quiescent; when stimulated by damage, they activate and expand to form new fibers. The mechanisms underlying SC proliferative progression remain poorly understood. Here we show that DHX36, a helicase that unwinds RNA G-quadruplex (rG4) structures, is essential for muscle regeneration by regulating SC expansion. DHX36 (initially named RHAU) is barely expressed at quiescence but is highly induced during SC activation and proliferation. Inducible deletion of Dhx36 in adult SCs causes defective proliferation and muscle regeneration after damage. System-wide mapping in proliferating SCs reveals DHX36 binding predominantly to rG4 structures at various regions of mRNAs, while integrated polysome profiling shows that DHX36 promotes mRNA translation via 5'-untranslated region (UTR) rG4 binding. Furthermore, we demonstrate that DHX36 specifically regulates the translation of Gnai2 mRNA by unwinding its 5' UTR rG4 structures and identify GNAI2 as a downstream effector of DHX36 for SC expansion. Altogether, our findings uncover DHX36 as an indispensable post-transcriptional regulator of SC function and muscle regeneration acting through binding and unwinding rG4 structures at 5' UTR of target mRNAs.


Assuntos
Regiões 5' não Traduzidas , RNA Helicases DEAD-box/metabolismo , Quadruplex G , Músculos/citologia , Regeneração/fisiologia , Células-Tronco/citologia , Animais , Animais Geneticamente Modificados , Células Cultivadas , Modelos Animais de Doenças , Subunidade alfa Gi2 de Proteína de Ligação ao GTP/metabolismo , Regulação da Expressão Gênica , Humanos , Camundongos , Músculos/metabolismo , Mioblastos/metabolismo , Polirribossomos/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/genética , Células-Tronco/metabolismo
15.
J Agric Food Chem ; 69(36): 10581-10591, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34432461

RESUMO

Intestinal stem cells (ISCs) are essential to maintain intestinal epithelial regeneration and barrier function. Our previous work showed that glucomannan from Aloe vera gel (AGP) alleviated epithelial damage, but the mechanism was still elusive. Herein, RNA-sequencing analysis showed that proliferation and differentiation of intestinal epithelial cells as well as the canonical Wnt pathway were involved in this process. Further experiments exhibited that AGP promoted nuclear translocation of ß-catenin and expression of transcription factor 7, increased the number of Lgr5+ ISCs, and differentiated epithelial cells in mice colon. Intriguingly, AGP reversed the inhibition of IEC-6 cells proliferation induced by an inhibitor of the canonical Wnt pathway. Hence, this study implied that AGP promoted proliferation and differentiation of colon stem cells via Wnt/ß-catenin signaling, which subsequently facilitated the regeneration of epithelial cells and alleviated colitis in mice. It may provide new insights into the role of polysaccharides in regulating intestinal homeostasis and relieving intestinal injury.


Assuntos
Via de Sinalização Wnt , beta Catenina , Animais , Diferenciação Celular , Proliferação de Células , Mucosa Intestinal/metabolismo , Mananas , Camundongos , Preparações de Plantas , Regeneração , Células-Tronco/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
16.
Int J Mol Sci ; 22(16)2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34445248

RESUMO

The functional neural circuits are partially repaired after an ischemic stroke in the central nervous system (CNS). In the CNS, neurovascular units, including neurons, endothelial cells, astrocytes, pericytes, microglia, and oligodendrocytes maintain homeostasis; however, these cellular networks are damaged after an ischemic stroke. The present review discusses the repair potential of stem cells (i.e., mesenchymal stem cells, endothelial precursor cells, and neural stem cells) and gaseous molecules (i.e., nitric oxide and carbon monoxide) with respect to neuroprotection in the acute phase and regeneration in the late phase after an ischemic stroke. Commonly shared molecular mechanisms in the neurovascular unit are associated with the vascular endothelial growth factor (VEGF) and its related factors. Stem cells and gaseous molecules may exert therapeutic effects by diminishing VEGF-mediated vascular leakage and facilitating VEGF-mediated regenerative capacity. This review presents an in-depth discussion of the regeneration ability by which endogenous neural stem cells and endothelial cells produce neurons and vessels capable of replacing injured neurons and vessels in the CNS.


Assuntos
Células Endoteliais/metabolismo , AVC Isquêmico/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Células-Tronco/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Células Endoteliais/patologia , Humanos , AVC Isquêmico/patologia , Neuroglia/patologia , Neurônios/patologia , Células-Tronco/patologia
17.
Int J Mol Sci ; 22(16)2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34445251

RESUMO

Exosomes secreted by adipose-derived stem cells (ADSC-exo) reportedly improve nerve regeneration after peripheral nerve injury. Herein, we investigated whether pretreatment of ADSCs with FK506, an immunosuppressive drug that enhances nerve regeneration, could secret exosomes (ADSC-F-exo) that further augment nerve regeneration. Designed exosomes were topically applied to injured nerve in a mouse model of sciatic nerve crush injury to assess the nerve regeneration efficacy. Outcomes were determined by histomorphometric analysis of semi-thin nerve sections stained with toluidine blue, mouse neurogenesis PCR array, and neurotrophin expression in distal nerve segments. Isobaric tags for relative and absolute quantitation (iTRAQ) were used to profile potential exosomal proteins facilitating nerve regeneration. We observed that locally applied ADSC-exo and ADSC-F-exo significantly enhanced nerve regeneration after nerve crush injury. Pretreatment of ADSCs with FK506 failed to produce exosomes possessing more potent molecules for enhanced nerve regeneration. Proteomic analysis revealed that of 192 exosomal proteins detected in both ADSC-exo and ADSC-F-exo, histone deacetylases (HDACs), amyloid-beta A4 protein (APP), and integrin beta-1 (ITGB1) might be involved in enhancing nerve regeneration.


Assuntos
Tecido Adiposo/metabolismo , Exossomos , Regeneração Nervosa , Traumatismos dos Nervos Periféricos/terapia , Nervos Periféricos/fisiologia , Células-Tronco/metabolismo , Tacrolimo/farmacologia , Animais , Exossomos/metabolismo , Exossomos/transplante , Camundongos , Traumatismos dos Nervos Periféricos/metabolismo
18.
Int J Mol Sci ; 22(16)2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34445257

RESUMO

The production of pancreatic ß cells is the most challenging step for curing diabetes using next-generation treatments. Adult pancreatic endocrine cells are thought to be maintained by the self-duplication of differentiated cells, and pancreatic endocrine neogenesis can only be observed when the tissue is severely damaged. Experimentally, this can be performed using a method named partial duct ligation (PDL). As the success rate of PDL surgery is low because of difficulties in identifying the pancreatic duct, we previously proposed a method for fluorescently labeling the duct in live animals. Using this method, we performed PDL on neurogenin3 (Ngn3)-GFP transgenic mice to determine the origin of endocrine precursor cells and evaluate their potential to differentiate into multiple cell types. Ngn3-activated cells, which were marked with GFP, appeared after PDL operation. Because some GFP-positive cells were aligned proximally to the duct, we hypothesized that Ngn3-positive cells arise from the pancreatic duct. Therefore, we next developed an in vitro pancreatic duct culture system using Ngn3-GFP mice and examined whether Ngn3-positive cells emerge from this duct. We observed GFP expressions in ductal organoid cultures. GFP expressions were correlated with Ngn3 expressions and endocrine cell lineage markers. Interestingly, tuft cell markers were also correlated with GFP expressions. Our results demonstrate that in adult mice, Ngn3-positive endocrine precursor cells arise from the pancreatic ducts both in vivo and in vitro experiments indicating that the pancreatic duct could be a potential donor for therapeutic use.


Assuntos
Antígenos de Diferenciação/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Células Secretoras de Insulina/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Ductos Pancreáticos/metabolismo , Células-Tronco/metabolismo , Animais , Antígenos de Diferenciação/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células Secretoras de Insulina/citologia , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Organoides/citologia , Organoides/metabolismo , Ductos Pancreáticos/citologia , Células-Tronco/citologia
19.
Int J Mol Sci ; 22(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34360579

RESUMO

Ischemic heart disease can lead to myocardial infarction (MI), a major cause of morbidity and mortality worldwide. Multiple stem cell types have been safely transferred into failing human hearts, but the overall clinical cardiovascular benefits have been modest. Therefore, there is a dire need to understand the basic biology of stem cells to enhance therapeutic effects. Bmi1 is part of the polycomb repressive complex 1 (PRC1) that is involved in different processes including proliferation, survival and differentiation of stem cells. We isolated cortical bones stem cells (CBSCs) from bone stroma, and they express significantly high levels of Bmi1 compared to mesenchymal stem cells (MSCs) and cardiac-derived stem cells (CDCs). Using lentiviral transduction, Bmi1 was knocked down in the CBSCs to determine the effect of loss of Bmi1 on proliferation and survival potential with or without Bmi1 in CBSCs. Our data show that with the loss of Bmi1, there is a decrease in CBSC ability to proliferate and survive during stress. This loss of functionality is attributed to changes in histone modification, specifically histone 3 lysine 27 (H3K27). Without the proper epigenetic regulation, due to the loss of the polycomb protein in CBSCs, there is a significant decrease in cell cycle proteins, including Cyclin B, E2F, and WEE as well as an increase in DNA damage genes, including ataxia-telangiectasia mutated (ATM) and ATM and Rad3-related (ATR). In conclusion, in the absence of Bmi1, CBSCs lose their proliferative potential, have increased DNA damage and apoptosis, and more cell cycle arrest due to changes in epigenetic modifications. Consequently, Bmi1 plays a critical role in stem cell proliferation and survival through cell cycle regulation, specifically in the CBSCs. This regulation is associated with the histone modification and regulation of Bmi1, therefore indicating a novel mechanism of Bmi1 and the epigenetic regulation of stem cells.


Assuntos
Apoptose , Proliferação de Células , Osso Cortical/citologia , Epigênese Genética , Histonas/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Células-Tronco/citologia , Animais , Ciclo Celular , Diferenciação Celular , Células Cultivadas , Osso Cortical/lesões , Osso Cortical/metabolismo , Dano ao DNA , Histonas/genética , Camundongos , Camundongos Endogâmicos C57BL , Complexo Repressor Polycomb 1/genética , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais , Células-Tronco/metabolismo
20.
Arch Insect Biochem Physiol ; 108(1): e21832, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34250644

RESUMO

Autophagy is a critical mechanism for the self-renewal, proliferation, and differentiation of stem cells. Bombyx mori midgut has stem cells that play a role in the regeneration of the larval epithelium in larval stages and the formation of the pupal midgut epithelium during larval-pupal metamorphosis. In this study, the role of the autophagy mechanism in midgut stem cells during the formation of the pupal midgut was investigated. For this purpose, two different doses of autophagy inhibitor chloroquine were administered to B. mori larvae on days 7 and 8 of the fifth larval stage. Morphological changes during the formation process of the pupal epithelium, expression levels of autophagy-related genes Atg8 and Atg12 in stem cells, and the amounts of lysosomal enzyme acid phosphatase were determined after the application. The obtained findings were evaluated in comparison with the control groups. Abnormalities in the formation of the pupal midgut after inhibition of autophagy showed the significance of the autophagy mechanism during this period.


Assuntos
Autofagia , Bombyx , Intestinos , Metamorfose Biológica/fisiologia , Células-Tronco , Fosfatase Ácida/efeitos dos fármacos , Fosfatase Ácida/metabolismo , Animais , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Bombyx/citologia , Bombyx/metabolismo , Bombyx/fisiologia , Cloroquina/farmacologia , Intestinos/citologia , Intestinos/efeitos dos fármacos , Larva/citologia , Larva/metabolismo , Pupa/citologia , Pupa/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...