Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 200
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 161(2): 277-90, 2015 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-25860610

RESUMO

Coordinated organ behavior is crucial for an effective response to environmental stimuli. By studying regeneration of hair follicles in response to patterned hair plucking, we demonstrate that organ-level quorum sensing allows coordinated responses to skin injury. Plucking hair at different densities leads to a regeneration of up to five times more neighboring, unplucked resting hairs, indicating activation of a collective decision-making process. Through data modeling, the range of the quorum signal was estimated to be on the order of 1 mm, greater than expected for a diffusible molecular cue. Molecular and genetic analysis uncovered a two-step mechanism, where release of CCL2 from injured hairs leads to recruitment of TNF-α-secreting macrophages, which accumulate and signal to both plucked and unplucked follicles. By coupling immune response with regeneration, this mechanism allows skin to respond predictively to distress, disregarding mild injury, while meeting stronger injury with full-scale cooperative activation of stem cells.


Assuntos
Folículo Piloso/citologia , Células-Tronco/citologia , Animais , Comunicação Celular , Quimiocina CCL2/metabolismo , Folículo Piloso/fisiologia , Queratinócitos/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Regeneração , Pele/citologia , Pele/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
2.
Gastroenterology ; 167(2): 343-356, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38342194

RESUMO

BACKGROUND & AIMS: Apoptosis generates plenty of membrane-bound nanovesicles, the apoptotic vesicles (apoVs), which show promise for biomedical applications. The liver serves as a significant organ for apoptotic material removal. Whether and how the liver metabolizes apoptotic vesicular products and contributes to liver health and disease is unrecognized. METHODS: apoVs were labeled and traced after intravenous infusion. Apoptosis-deficient mice by Fas mutant (Fasmut) and Caspase-3 knockout (Casp3-/-) were used with apoV replenishment to evaluate the physiological apoV function. Combinations of morphologic, biochemical, cellular, and molecular assays were applied to assess the liver while hepatocyte analysis was performed. Partial hepatectomy and acetaminophen liver failure models were established to investigate liver regeneration and disease recovery. RESULTS: We discovered that the liver is a major metabolic organ of circulatory apoVs, in which apoVs undergo endocytosis by hepatocytes via a sugar recognition system. Moreover, apoVs play an indispensable role to counteract hepatocellular injury and liver impairment in apoptosis-deficient mice upon replenishment. Surprisingly, apoVs form a chimeric organelle complex with the hepatocyte Golgi apparatus through the soluble N-ethylmaleimide-sensitive factor attachment protein receptor machinery, which preserves Golgi integrity, promotes microtubule acetylation by regulating α-tubulin N-acetyltransferase 1, and consequently facilitates hepatocyte cytokinesis for liver recovery. The assembly of the apoV-Golgi complex is further revealed to contribute to liver homeostasis, regeneration, and protection against acute liver failure. CONCLUSIONS: These findings establish a previously unrecognized functional and mechanistic framework that apoptosis through vesicular metabolism safeguards liver homeostasis and regeneration, which holds promise for hepatic disease therapeutics.


Assuntos
Apoptose , Hepatócitos , Homeostase , Regeneração Hepática , Fígado , Camundongos Knockout , Animais , Hepatócitos/metabolismo , Hepatócitos/patologia , Fígado/metabolismo , Fígado/patologia , Caspase 3/metabolismo , Camundongos , Hepatectomia , Modelos Animais de Doenças , Receptor fas/metabolismo , Receptor fas/genética , Complexo de Golgi/metabolismo , Endocitose , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/genética , Camundongos Endogâmicos C57BL , Acetaminofen , Masculino
3.
Immunity ; 43(2): 251-63, 2015 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-26275994

RESUMO

Regulatory T (Treg) cells are essential for maintenance of immune homeostasis. Here we found that hydrogen sulfide (H2S) was required for Foxp3(+) Treg cell differentiation and function and that H2S deficiency led to systemic autoimmune disease. H2S maintained expression of methylcytosine dioxygenases Tet1 and Tet2 by sulfhydrating nuclear transcription factor Y subunit beta (NFYB) to facilitate its binding to Tet1 and Tet2 promoters. Transforming growth factor-ß (TGF-ß)-activated Smad3 and interleukin-2 (IL-2)-activated Stat5 facilitated Tet1 and Tet2 binding to Foxp3. Tet1 and Tet2 catalyzed conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) in Foxp3 to establish a Treg-cell-specific hypomethylation pattern and stable Foxp3 expression. Consequently, Tet1 and Tet2 deletion led to Foxp3 hypermethylation, impaired Treg cell differentiation and function, and autoimmune disease. Thus, H2S promotes Tet1 and Tet2 expression, which are recruited to Foxp3 by TGF-ß and IL-2 signaling to maintain Foxp3 demethylation and Treg-cell-associated immune homeostasis.


Assuntos
Colite/imunologia , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Sulfeto de Hidrogênio/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Animais , Fator de Ligação a CCAAT/metabolismo , Diferenciação Celular/genética , Colite/genética , Metilação de DNA/genética , Proteínas de Ligação a DNA/genética , Dioxigenases , Fatores de Transcrição Forkhead/genética , Homeostase/genética , Homeostase/imunologia , Humanos , Interleucina-2/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Proto-Oncogênicas/genética , Fator de Transcrição STAT5/metabolismo , Proteína Smad3/metabolismo , Linfócitos T Reguladores/transplante , Fator de Crescimento Transformador beta/imunologia
4.
J Cell Physiol ; 238(7): 1542-1557, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37120836

RESUMO

Large bone defect reconstruction undergoes hypoxia and remains a major practical challenge. Bone tissue engineering with a more promising stem cell source facilitates the development of better therapeutic outcomes. Human dental follicle stem cells (hDFSCs) with superior multipotency, osteogenic capacity, and accessibility have been proven a promising cell source for bone regeneration. We previously identified a novel long noncoding RNA (lncRNA), HOTAIRM1, to be highly expressed in hDFSCs. Here we found that HOTAIRM1 overexpressed hDFSCs promoted bone regeneration in rat critical-size calvarial defect model. Mechanically, HOTAIRM1 was induced in hDFSCs under hypoxic conditions and activated HIF-1α. RNA-sequencing analysis indicated that HOTAIRM1 upregulated oxygen-sensing histone demethylases KDM6A/B and suppressed methyltransferase EZH2 via targeting HIF-1α. The osteogenic differentiation of hDFSCs was accompanied with demethylation of H3K27, and HOTAIRM1 overexpression decreased the distribution of H3K27me3 in osteogenic genes, including ALP, M-CSF, Wnt-3a, Wnt-5a, Wnt-7a, and ß-catenin, thus promoted their transcription. Our study provided evidence that HOTAIRM1 upregulated KDM6A/B and inhibited EZH2 in a HIF-1α dependent manner to enhance the osteogenesis of hDFSCs. HOTAIRM1-mediated hDFSCs may serve as a promising therapeutic approach to promote bone regeneration in clinical practice.


Assuntos
Regeneração Óssea , RNA Longo não Codificante , Animais , Humanos , Ratos , Diferenciação Celular , Saco Dentário , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Histonas/genética , Osteogênese , RNA Longo não Codificante/genética , Células-Tronco/metabolismo
5.
Small ; 19(40): e2301748, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37282762

RESUMO

Extracellular vesicles (EVs) are lipid bilayer nanovesicles released from living or apoptotic cells that can transport DNA, RNA, protein, and lipid cargo. EVs play critical roles in cell-cell communication and tissue homeostasis, and have numerous therapeutic uses including serving as carriers for nanodrug delivery. There are multiple ways to load EVs with nanodrugs, such as electroporation, extrusion, and ultrasound. However, these approaches may have limited drug-loading rates, poor EV membrane stability, and high cost for large-scale production. Here, it is shown that apoptotic mesenchymal stem cells (MSCs) can encapsulate exogenously added nanoparticles into apoptotic vesicles (apoVs) with a high loading efficiency. When nano-bortezomib is incorporated into apoVs in culture-expanded apoptotic MSCs, nano-bortezomib-apoVs show a synergistic combination effect of bortezomib and apoVs to ameliorate multiple myeloma (MM) in a mouse model, along with significantly reduced side effects of nano-bortezomib. Moreover, it is shown that Rab7 regulates the nanoparticle encapsulation efficiency in apoptotic MSCs and that activation of Rab7 can increase nanoparticle-apoV production. In this study, a previously unknown mechanism to naturally synthesize nano-bortezomib-apoVs to improve MM therapy is revealed.


Assuntos
Vesículas Extracelulares , Células-Tronco Mesenquimais , Mieloma Múltiplo , Animais , Camundongos , Bortezomib/farmacologia , Bortezomib/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/metabolismo , Vesículas Extracelulares/metabolismo , Comunicação Celular
6.
J Nanobiotechnology ; 21(1): 407, 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37924105

RESUMO

Rapid hemostasis of uncontrolled bleeding following traumatic injuries, especially accompanied by coagulopathies, remains a significant clinical challenge. Extracellular vesicles (EVs) show therapeutic effects for fast clotting. However, low yield, specific storage conditions, and lack of proper carriers have hindered EVs' clinical application. Herein, we establish an optimized procedure method to generate lyophilized mesenchymal stem cell-derived apoptotic vesicles (apoVs) with adhesive hydrogel sponge to show superior procoagulant activity for traumatic hemorrhage. Mechanistically, apoVs' procoagulant ability stems from their high tissue factor (TF) and phosphatidylserine (PS) expression independent of hemocytes and circulating procoagulant microparticles (cMPs). Their stable hemostatic capability was maintained after 2-month room temperature storage. Subsequently, we mixed apoVs with both phenylboronic acid grafted oxidized hyaluronic acid (PBA-HA) and poly(vinyl alcohol) (PVA) simultaneously, followed by lyophilization to construct a novel apoV-encapsulated hydrogel sponge (apoV-HS). Compared to commercial hemostats, apoV-HS exhibits rapid procoagulant ability in liver-laceration and femoral artery hemorrhage in rat and rabbit models of coagulopathies. The combination of high productivity, physiological stability, injectability, plasticity, excellent adhesivity, biocompatibility, and rapid coagulant property indicates that apoV-HS is a promising therapeutic approach for heavy hemorrhage in civilian and military populations.


Assuntos
Vesículas Extracelulares , Hemostáticos , Ratos , Animais , Coelhos , Adesivos , Hidrogéis , Hemostáticos/farmacologia , Hemorragia/tratamento farmacológico
7.
Small ; 18(20): e2200306, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35481721

RESUMO

Mesenchymal stem cell (MSC) therapy can attenuate organ damage and reduce mortality in sepsis; however, the detailed mechanism is not fully elucidated. In this study, it is shown that MSC-derived apoptotic vesicles (apoVs) can ameliorate multiple organ dysfunction and improve survival in septic mice. Mechanistically, it is found that tail vein-infused apoVs mainly accumulate in the bone marrow of septic mice via electrostatic charge interactions with positively charged neutrophil extracellular traps (NETs). Moreover, apoVs switch neutrophils NETosis to apoptosis via the apoV-Fas ligand (FasL)-activated Fas pathway. In summary, these findings uncover a previously unknown role of apoVs in sepsis treatment and an electrostatic charge-directed target therapeutic mechanism, suggesting that cell death is associated with disease development and therapy.


Assuntos
Neutrófilos , Sepse , Animais , Apoptose/fisiologia , Camundongos , Sepse/terapia , Eletricidade Estática , Distribuição Tecidual
8.
BMC Surg ; 21(1): 78, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568109

RESUMO

BACKGROUND: The radical antegrade modular pancreatosplenectomy (RAMPS) which is a reasonable surgical approach for left-sided pancreatic cancer is emphasis on the complete resection of regional lymph nodes and tumor-free margin resection. Laparoscopic radical antegrade modular pancreatosplenectomy (LRAMPS) has been rarely performed, with only 49 cases indexed on PubMed. In this study, we present our experience of LRAMPS. METHODS: From December 2018 to February 2020, 10 patients underwent LRAMPS for pancreatic cancer at our department. The data of the patient demographics, intraoperative variables, postoperative hospital stay, morbidity, mortality, pathologic findings and follow-up were collected. RESULTS: LRAMPS was performed successfully in all the patients. The median operative time was 235 min (range 212-270 min), with an EBL of 120 ml (range 100-200 ml). Postoperative complications occurred in 5 (50.0%) patients. Three patients developed a grade B pancreatic fistula. There was no postoperative 30-day mortality and reoperation. The median postoperative hospital stay was 14 days (range 9-24 days).The median count of retrieved lymph nodes was 15 (range 13-21), and four patients (40%) had malignant-positive lymph nodes. All cases achieved a negative tangential margin and R0 resection. Median follow-up time was 11 months (range 3-14 m). Two patients developed disease recurrence (pancreatic bed recurrence and liver metastasis) 9 months, 10 months after surgery, respectively. Others survived without tumor recurrence or metastasis. CONCLUSIONS: LRAMPS is technically safe and feasible procedure in well-selected patients with pancreatic cancer in the distal pancreas. The oncologically outcomes need to be further validated based on additional large-volume studies.


Assuntos
Laparoscopia , Pancreatectomia , Neoplasias Pancreáticas , Esplenectomia , Humanos , Recidiva Local de Neoplasia , Pancreatectomia/métodos , Neoplasias Pancreáticas/cirurgia , Estudos Retrospectivos , Esplenectomia/métodos , Resultado do Tratamento
9.
Am J Physiol Cell Physiol ; 319(5): C895-C905, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32755451

RESUMO

Interstitial lung disease (ILD) comprises of a group of diffuse parenchymal lung disorders that are strongly associated with substantial morbidity and mortality. Previous studies have highlighted the therapeutic significance of microRNAs (miRNAs) in the treatment of ILD. Thus this study aims to investigate the mechanism by which miR-140 affects ILD through the regulation of osteoglycin (OGN)-Wnt signaling pathway. Gene expression microarray analysis was performed to screen ILD-related differentially expressed genes and miRNAs that regulated OGN. The targeting relationship between miR-140 and OGN was verified. Ectopic expression and knockdown experiments were performed in lung fibroblasts to explore the potential mechanism of action of miR-140 in ILD. The expression of miR-140, OGN, as well as Wnt- and pulmonary fibrosis-related factors, was determined by RT-qPCR and Western blot analysis. In addition, cell viability and apoptosis were examined. OGN was found to be negatively regulated by miR-140. The ectopic expression of miR-140 and OGN silencing resulted in increased lung fibroblast apoptosis and Wnt3a expression, along with reduced proliferation and pulmonary fibrosis. Our results also revealed that miR-140 decreased OGN, thereby activating the Wnt signaling pathway, which was observed to further affect the expression of genes associated with the progression of pulmonary fibrosis in mouse fibroblasts. In conclusion, the key findings from our study suggest that overexpressed miR-140 suppresses ILD development via the Wnt signaling pathway by downregulating OGN, which could potentially be used as a therapeutic target for ILD.


Assuntos
Fibroblastos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Doenças Pulmonares Intersticiais/genética , Pulmão/metabolismo , MicroRNAs/genética , Fibrose Pulmonar/genética , Proteína Wnt3A/genética , Animais , Apoptose/genética , Pareamento de Bases , Sequência de Bases , Bleomicina/administração & dosagem , Estudos de Casos e Controles , Proliferação de Células , Sobrevivência Celular , Modelos Animais de Doenças , Feminino , Fibroblastos/patologia , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Pulmão/patologia , Doenças Pulmonares Intersticiais/induzido quimicamente , Doenças Pulmonares Intersticiais/metabolismo , Doenças Pulmonares Intersticiais/patologia , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Cultura Primária de Células , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Via de Sinalização Wnt , Proteína Wnt3A/metabolismo
10.
Am J Hum Genet ; 99(1): 195-201, 2016 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-27321946

RESUMO

Tooth agenesis is one of the most common developmental anomalies in humans. Oligodontia, a severe form of tooth agenesis, is genetically and phenotypically a heterogeneous condition. Although significant efforts have been made, the genetic etiology of dental agenesis remains largely unknown. In the present study, we performed whole-exome sequencing to identify the causative mutations in Chinese families in whom oligodontia segregates with dominant inheritance. We detected a heterozygous missense mutation (c.632G>A [p.Arg211Gln]) in WNT10B in all affected family members. By Sanger sequencing a cohort of 145 unrelated individuals with non-syndromic oligodontia, we identified three additional mutations (c.569C>G [p.Pro190Arg], c.786G>A [p.Trp262(∗)], and c.851T>G [p.Phe284Cys]). Interestingly, analysis of genotype-phenotype correlations revealed that mutations in WNT10B affect the development of permanent dentition, particularly the lateral incisors. Furthermore, a functional assay demonstrated that each of these mutants could not normally enhance the canonical Wnt signaling in HEPG2 epithelial cells, in which activity of the TOPFlash luciferase reporter was measured. Notably, these mutant WNT10B ligands could not efficiently induce endothelial differentiation of dental pulp stem cells. Our findings provide the identification of autosomal-dominant WNT10B mutations in individuals with oligodontia, which increases the spectrum of congenital tooth agenesis and suggests attenuated Wnt signaling in endothelial differentiation of dental pulp stem cells.


Assuntos
Anodontia/genética , Mutação de Sentido Incorreto/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Wnt/genética , Povo Asiático/genética , Sequência de Bases , China , Polpa Dentária/patologia , Exoma/genética , Feminino , Estudos de Associação Genética , Células Hep G2 , Heterozigoto , Humanos , Masculino , Linhagem , Dente/patologia , Via de Sinalização Wnt/genética
11.
Cell Mol Life Sci ; 74(24): 4443-4453, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28674727

RESUMO

Alcoholic beverages are widely consumed, resulting in a staggering economic cost in different social and cultural settings. Types of alcohol consumption vary from light occasional to heavy, binge drinking, and chronic alcohol abuse at all ages. In general, heavy alcohol consumption is widely recognized as a major epidemiological risk factor for chronic diseases and is detrimental to many organs and tissues, including bones. Indeed, recent findings demonstrate that alcohol has a dose-dependent toxic effect in promoting imbalanced bone remodeling. This imbalance eventually results in osteopenia, an established risk factor for osteoporosis. Decreased bone mass and strength are major hallmarks of osteopenia, which is predominantly attributed not only to inhibition of bone synthesis but also to increased bone resorption through direct and indirect pathways. In this review, we present knowledge to elucidate the epidemiology, potential pathogenesis, and major molecular mechanisms and cellular effects that underlie alcoholism-induced bone loss in osteopenia. Novel therapeutic targets for correcting alcohol-induced osteopenia are also reviewed, such as modulation of proinflammatory cytokines and Wnt and mTOR signaling and the application of new drugs.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Doenças Ósseas Metabólicas/induzido quimicamente , Etanol/efeitos adversos , Alcoolismo/complicações , Alcoolismo/patologia , Animais , Doenças Ósseas Metabólicas/complicações , Doenças Ósseas Metabólicas/patologia , Reabsorção Óssea/induzido quimicamente , Reabsorção Óssea/patologia , Humanos , Osteoporose/etiologia , Osteoporose/patologia , Fatores de Risco
12.
Ann Plast Surg ; 80(5S Suppl 5): S317-S321, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29553981

RESUMO

Impaired healing of the skin is a notable cause of patient morbidity and mortality. In diabetic individuals, dysregulated inflammation contributes to delayed wound healing. Specific immunomodulatory agents may have a role in the treatment of diabetic wounds. One of these molecules is interleukin-1 receptor antagonist (Anakinra; Amgen Corp.). Although interleukin-1 receptor antagonist (Anakinra; Amgen Corp.) is approved by the Food and Drug Administration (FDA) for the treatment of rheumatoid arthritis and neonatal-onset multisystem inflammatory disease, little is known about the local use this drug in cutaneous wound healing. Therefore, the aim of this study is to determine the effect of locally administered interleukin-1 receptor antagonist on delayed wound healing, specifically, in a diabetic mouse model. Two 6-mm full-thickness wounds were created on the dorsa of diabetic (db/db) mice and stented. One-hour postwounding, wound margins were subcutaneously injected with either (1) low-dose interleukin-1 receptor antagonist in a gelatin-transglutaminase gel vehicle or (2) the gel vehicle only. Wounds were imaged on days 0, 7, 14, and 21 postwounding, and wound area was determined. Wound biopsies were collected on day 21 and immunohistochemically stained for neutrophil and macrophage infiltration. Wounds treated with interleukin-1 receptor antagonist had significantly smaller wound area than nontreated wounds on day 7 and day 14 postwounding. Treated wounds also showed significantly less neutrophil and macrophage infiltration. These findings support the hypothesis that interleukin-1 receptor antagonist may have an important role in cutaneous wound healing, possibly by promoting successful resolution of acute inflammation and hence accelerating wound closure. Thereby, administration of IL-1Ra may be useful in the treatment of nonhealing wounds.


Assuntos
Complicações do Diabetes/tratamento farmacológico , Diabetes Mellitus Experimental/tratamento farmacológico , Proteína Antagonista do Receptor de Interleucina 1/administração & dosagem , Cicatrização/efeitos dos fármacos , Administração Cutânea , Animais , Complicações do Diabetes/patologia , Diabetes Mellitus Experimental/patologia , Modelos Animais de Doenças , Humanos , Contagem de Leucócitos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Neutrófilos/efeitos dos fármacos , Neutrófilos/patologia , Pele/efeitos dos fármacos , Pele/patologia
13.
Stem Cells ; 34(6): 1576-87, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26866635

RESUMO

Vasculogenesis is the process of de novo blood vessel formation observed primarily during embryonic development. Emerging evidence suggest that postnatal mesenchymal stem cells are capable of recapitulating vasculogenesis when these cells are engaged in tissue regeneration. However, the mechanisms underlining the vasculogenic differentiation of mesenchymal stem cells remain unclear. Here, we used stem cells from human permanent teeth (dental pulp stem cells [DPSC]) or deciduous teeth (stem cells from human exfoliated deciduous teeth [SHED]) as models of postnatal primary human mesenchymal stem cells to understand mechanisms regulating their vasculogenic fate. GFP-tagged mesenchymal stem cells seeded in human tooth slice/scaffolds and transplanted into immunodeficient mice differentiate into human blood vessels that anastomize with the mouse vasculature. In vitro, vascular endothelial growth factor (VEGF) induced the vasculogenic differentiation of DPSC and SHED via potent activation of Wnt/ß-catenin signaling. Further, activation of Wnt signaling is sufficient to induce the vasculogenic differentiation of postnatal mesenchymal stem cells, while Wnt inhibition blocked this process. Notably, ß-catenin-silenced DPSC no longer differentiate into endothelial cells in vitro, and showed impaired vasculogenesis in vivo. Collectively, these data demonstrate that VEGF signaling through the canonical Wnt/ß-catenin pathway defines the vasculogenic fate of postnatal mesenchymal stem cells. Stem Cells 2016;34:1576-1587.


Assuntos
Células-Tronco Mesenquimais/citologia , Neovascularização Fisiológica , Via de Sinalização Wnt , Animais , Diferenciação Celular/efeitos dos fármacos , Colágeno/farmacologia , Polpa Dentária/citologia , Combinação de Medicamentos , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Técnicas de Silenciamento de Genes , Inativação Gênica/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/metabolismo , Células HEK293 , Humanos , Laminina/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Camundongos SCID , Neovascularização Fisiológica/efeitos dos fármacos , Proteoglicanas/farmacologia , Fator A de Crescimento do Endotélio Vascular/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/metabolismo
14.
Stem Cells ; 34(8): 2157-68, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27145264

RESUMO

Chronic consumption of excessive alcohol results in reduced bone mass, impaired bone structure, and increased risk of bone fracture. However, the mechanisms underlying alcohol-induced osteoporosis are not fully understood. Here, we show that high dose chronic alcohol consumption reduces osteogenic differentiation and enhances adipogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs), leading to osteopenia in a mouse model. Mechanistically, impaired osteo/adipogenic lineage differentiation of BMMSCs is due to activation of a phosphatidylinositide 3-kinase/AKT/mammalian target of rapamycin (mTOR) signaling cascade, resulting in downregulation of runt-related transcription factor 2 and upregulation of peroxisome proliferator-activated receptor gamma via activation of p70 ribosomal protein S6 kinase. Blockage of the mTOR pathway by rapamycin treatment ameliorates alcohol-induced osteopenia by rescuing impaired osteo/adipogenic lineage differentiation of BMMSCs. In this study, we identify a previously unknown mechanism by which alcohol impairs BMMSC lineage differentiation and reveal a potential rapamycin-based drug therapy for alcohol-induced osteoporosis. Stem Cells 2016;34:2157-2168.


Assuntos
Doenças Ósseas Metabólicas/etiologia , Doenças Ósseas Metabólicas/metabolismo , Células da Medula Óssea/patologia , Etanol/efeitos adversos , Células-Tronco Mesenquimais/patologia , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Adipogenia/efeitos dos fármacos , Animais , Células da Medula Óssea/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Feminino , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Camundongos Nus , Fenótipo , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia
15.
J Mater Sci Mater Med ; 28(10): 162, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28914392

RESUMO

Cartilage tissue regeneration often presents a challenging clinical situation. Recently, it has been shown that Periodontal Ligament Stem Cells (PDLSCs) possess high chondrogenic differentiation capacity. In this study, we developed a stem cell delivery system based on alginate/hyaluronic acid (HA) loaded with TGF-ß1 ligand, encapsulating PDLSCs; and investigated the chondrogenic differentiation of encapsulated cells in alginate/HA hydrogel microspheres in vitro and in vivo. The results showed that PDLSCs, as well as human bone marrow mesenchymal stem cells (hBMMSCs), as the positive control, were stained positive for both toluidine blue and alcian blue staining, while exhibiting high levels of gene expression related to chondrogenesis (Col II, Aggrecan and Sox-9), as assessed via qPCR. The quantitative PCR analyses exhibited that the chondrogenic differentiation of encapsulated MSCs can be regulated by the modulus of elasticity of hydrogel delivery system, confirming the vital role of the microenvironment, and the presence of inductive signals for viability and differentiation of MSCs. In vivo, histological and immunofluorescence staining for chondrogenic specific protein markers confirmed ectopic cartilage-like tissue regeneration inside transplanted hydrogels. PDLSCs presented significantly greater capability for chondrogenic differentiation than hBMMSCs (P < 0.05). Altogether, our findings confirmed that alginate/HA hydrogels encapsulating PDLSCs are a promising candidate for cartilage regeneration.


Assuntos
Alginatos/química , Diferenciação Celular/efeitos dos fármacos , Condrócitos/efeitos dos fármacos , Condrogênese/efeitos dos fármacos , Portadores de Fármacos/farmacologia , Sistemas de Liberação de Medicamentos , Ácido Hialurônico/química , Hidrogel de Polietilenoglicol-Dimetacrilato/farmacologia , Ligamento Periodontal/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Adolescente , Adulto , Alginatos/farmacologia , Animais , Células Cultivadas , Condrócitos/fisiologia , Condrogênese/fisiologia , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Ácido Glucurônico/química , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/química , Ácidos Hexurônicos/farmacologia , Humanos , Ácido Hialurônico/farmacologia , Hidrogel de Polietilenoglicol-Dimetacrilato/síntese química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Teste de Materiais , Camundongos , Camundongos Nus , Microesferas , Ligamento Periodontal/citologia , Ligamento Periodontal/fisiologia , Células-Tronco/citologia , Células-Tronco/fisiologia , Adulto Jovem
16.
J Immunol ; 193(10): 5306-14, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25339674

RESUMO

Mesenchymal stem cells (MSC) from healthy human and normal mice can inhibit normal B cell proliferation, differentiation, and Ab secretion in vitro. However, it remains unknown whether MSC from lupus-like mice and patients with systemic lupus erythematosus (SLE) exhibit the same immunoregulatory activity as normal MSC for B cell inhibition and, if not, what the underlying molecular mechanism would be. In this study, we showed that bone marrow-derived MSCs from lupus-like mice and SLE patients had an impairment in suppressing normal B cell proliferation and differentiation, which was caused by the reduction of CCL2 levels. Knockdown of CCL2 in normal MSC damaged their suppressive capacity for B cells. Conversely, overexpression of CCL2 in lupus MSCs restored their immunoregulatory ability for B cells in vitro and ameliorated the pathology of lupus nephritis and serological changes in MRL/lpr mice in vivo. Mechanistically, MSC-mediated B cell inhibition was dependent on matrix metalloproteinase proteolytic processing of CCL2. These findings reveal a novel function of CCL2 in B cell regulation by MSCs and suggest that CCL2 manipulation on MSCs may serve as a potential pathway for developing the more effective MSC-based therapy in autoimmune diseases associated with B cell activation, such as SLE.


Assuntos
Linfócitos B/imunologia , Células da Medula Óssea/imunologia , Quimiocina CCL2/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Células-Tronco Mesenquimais/imunologia , Animais , Linfócitos B/patologia , Células da Medula Óssea/patologia , Comunicação Celular/imunologia , Quimiocina CCL2/antagonistas & inibidores , Quimiocina CCL2/genética , Feminino , Regulação da Expressão Gênica , Humanos , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/patologia , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/imunologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , Proteólise , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Transplante Homólogo
17.
J Prosthodont ; 25(2): 105-15, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26216081

RESUMO

PURPOSE: Peri-implantitis is one of the most common inflammatory complications in dental implantology. Similar to periodontitis, in peri-implantitis, destructive inflammatory changes take place in the tissues surrounding a dental implant. Bacterial flora at the failing implant sites resemble the pathogens in periodontal disease and consist of Gram-negative anaerobic bacteria including Aggregatibacter actinomycetemcomitans (Aa). Here we demonstrate the effectiveness of a silver lactate (SL)-containing RGD-coupled alginate hydrogel scaffold as a promising stem cell delivery vehicle with antimicrobial properties. MATERIALS AND METHODS: Gingival mesenchymal stem cells (GMSCs) or human bone marrow mesenchymal stem cells (hBMMSCs) were encapsulated in SL-loaded alginate hydrogel microspheres. Stem cell viability, proliferation, and osteo-differentiation capacity were analyzed. RESULTS: Our results showed that SL exhibited antimicrobial properties against Aa in a dose-dependent manner, with 0.50 mg/ml showing the greatest antimicrobial properties while still maintaining cell viability. At this concentration, SL-containing alginate hydrogel was able to inhibit Aa growth on the surface of Ti discs and significantly reduce the bacterial load in Aa suspensions. Silver ions were effectively released from the SL-loaded alginate microspheres for up to 2 weeks. Osteogenic differentiation of GMSCs and hBMMSCs encapsulated in the SL-loaded alginate microspheres were confirmed by the intense mineral matrix deposition and high expression of osteogenesis-related genes. CONCLUSION: Taken together, our findings confirm that GMSCs encapsulated in RGD-modified alginate hydrogel containing SL show promise for bone tissue engineering with antimicrobial properties against Aa bacteria in vitro.


Assuntos
Hidrogel de Polietilenoglicol-Dimetacrilato , Células-Tronco Mesenquimais , Peri-Implantite/terapia , Alginatos , Anti-Infecciosos , Humanos , Osteogênese
18.
Adv Funct Mater ; 25(15): 2296-2307, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26120294

RESUMO

The host immune system is known to influence mesenchymal stem cell (MSC)-mediated bone tissue regeneration. However, the therapeutic capacity of hydrogel biomaterial to modulate the interplay between MSCs and T-lymphocytes is unknown. Here it is shown that encapsulating hydrogel affects this interplay when used to encapsulate MSCs for implantation by hindering the penetration of pro-inflammatory cells and/or cytokines, leading to improved viability of the encapsulated MSCs. This combats the effects of the host pro-inflammatory T-lymphocyte-induced nuclear factor kappaB pathway, which can reduce MSC viability through the CASPASE-3 and CAS-PASE-8 associated proapoptotic cascade, resulting in the apoptosis of MSCs. To corroborate rescue of engrafted MSCs from the insult of the host immune system, the incorporation of the anti-inflammatory drug indomethacin into the encapsulating alginate hydrogel further regulates the local microenvironment and prevents pro-inflammatory cytokine-induced apoptosis. These findings suggest that the encapsulating hydrogel can regulate the MSC-host immune cell interplay and direct the fate of the implanted MSCs, leading to enhanced tissue regeneration.

19.
Am J Pathol ; 184(11): 3084-93, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25173134

RESUMO

Drug-induced osteonecrosis of the jaw (ONJ) is a detrimental intraoral lesion that often occurs after dental-related interventions in patients undergoing treatment with bisphosphonates or denosumab, the neutralizing human anti-receptor activator of NF-κB ligand (RANKL) antibody (Ab). The cause of ONJ by these drugs has been speculated to their direct effects on osteoclasts. However, the extent to which osteoclasts contribute to ONJ pathogenesis remains controversial. Herein, by using a tooth-extraction mouse model with i.v. administration of mouse anti-RANKL Ab or the bisphosphonate zoledronate (ZOL), we show that unresorbed bone due to impaired formation or suppressed functions of osteoclasts, respectively, is associated with ONJ development. After tooth extraction, ONJ-like lesions developed 50% in the anti-RANKL Ab-treated mice and 30% in the ZOL-treated mice. Nonviable and unresorbed bone was found more in anti-RANKL Ab-treated mice compared with mice receiving ZOL. All mice receiving anti-RANKL Ab had an undetectable tartrate-resistant acid phosphatase (TRAP) level in the serum and no TRAP-positive osteoclasts at the extracted sockets, whereas ZOL-treated mice had a decreased TRAP level without altering the numbers of TRAP-positive osteoclasts. Interestingly, the absence of newly formed woven bone in the extracted sockets was evident in ONJ-like lesions from both anti-RANKL Ab- and ZOL-treated mice. Our study suggests that the lack of osteoclasts' bone-resorptive functions by these drugs and suppression of woven bone formation after dental trauma may be associated with ONJ development.


Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/patologia , Reabsorção Óssea/patologia , Osteoclastos/patologia , Ligante RANK/antagonistas & inibidores , Animais , Anticorpos Monoclonais Humanizados , Denosumab , Difosfonatos , Modelos Animais de Doenças , Imidazóis , Camundongos , Osteoclastos/efeitos dos fármacos , Ácido Zoledrônico
20.
Mol Vis ; 21: 138-47, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25684979

RESUMO

PURPOSE: Previously, we demonstrated that scleral stem/progenitor cells (SSPCs) from mice have a chondrogenic differentiation potential, which is stimulated by transforming growth factor-ß (TGF-ß). In the present study, we hypothesized that chondrogenesis in the sclera could be a possible mechanism in myopia development. Therefore, we investigated the association of form-deprivation myopia (FDM) with expressions in mice sclera representing the chondrogenic phenotype: collagen type II (Col2) and α-smooth muscle actin (α-SMA). METHODS: The mRNA levels of α-SMA and Col2 in cultured murine SSPCs during chondrogenesis stimulated by TGF-ß2 were determined by real-time quantitative RT-PCR (qRT-PCR). The expression patterns of α-SMA and Col2 were assessed by immunohistochemistry in a three dimensional pellet culture. In an FDM mouse model, a western blot analysis and immunofluorescence study were used to detect the changes in the α-SMA and Col2 protein expressions in the sclera. In the RPE-choroid complex, qRT-PCR was used to detect any changes in the TGF-ß mRNA expression. RESULTS: The treatment of SSPCs in vitro with TGF-ß2 for 24 h at 1 or 10 ng/ml led to increased levels of both the α-SMA and Col2 expressions. In addition, we observed the formation of cartilage-like pellets from TGF-ß2-treated SSPCs. Both α-SMA and Col2 were expressed in the pellet. In an in-vivo study, the α-SMA and Col2 protein expressions were significantly increased in the sclera of FDM eyes in comparison to contralateral control eyes. Similarly, the levels of TGF-ß in the RPE-choroid complex of an FDM eye were also significantly elevated. CONCLUSION: Based on the concept of stem cells possessing multipotent differentiation potentials, scleral chondrogenesis induced by SSPCs may play a role in myopia development. The increased expressions of the cartilage-associated proteins Col2 and α-SMA during scleral chondrogenesis may be potential markers for myopia development. In addition, the increased levels of TGF-ß mRNA in the RPE-choroid complex might induce the chondrogenic change in the sclera during myopia development.


Assuntos
Condrogênese/genética , Corioide/patologia , Miopia/patologia , Epitélio Pigmentado da Retina/patologia , Esclera/patologia , Células-Tronco/patologia , Actinas/agonistas , Actinas/genética , Actinas/metabolismo , Animais , Células Cultivadas , Corioide/metabolismo , Colágeno Tipo II/agonistas , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miopia/genética , Miopia/metabolismo , RNA Mensageiro/agonistas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Esclera/efeitos dos fármacos , Esclera/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Fator de Crescimento Transformador beta/agonistas , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta2/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA