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1.
Nature ; 618(7966): 808-817, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37344645

RESUMO

Niche signals maintain stem cells in a prolonged quiescence or transiently activate them for proper regeneration1. Altering balanced niche signalling can lead to regenerative disorders. Melanocytic skin nevi in human often display excessive hair growth, suggesting hair stem cell hyperactivity. Here, using genetic mouse models of nevi2,3, we show that dermal clusters of senescent melanocytes drive epithelial hair stem cells to exit quiescence and change their transcriptome and composition, potently enhancing hair renewal. Nevus melanocytes activate a distinct secretome, enriched for signalling factors. Osteopontin, the leading nevus signalling factor, is both necessary and sufficient to induce hair growth. Injection of osteopontin or its genetic overexpression is sufficient to induce robust hair growth in mice, whereas germline and conditional deletions of either osteopontin or CD44, its cognate receptor on epithelial hair cells, rescue enhanced hair growth induced by dermal nevus melanocytes. Osteopontin is overexpressed in human hairy nevi, and it stimulates new growth of human hair follicles. Although broad accumulation of senescent cells, such as upon ageing or genotoxic stress, is detrimental for the regenerative capacity of tissue4, we show that signalling by senescent cell clusters can potently enhance the activity of adjacent intact stem cells and stimulate tissue renewal. This finding identifies senescent cells and their secretome as an attractive therapeutic target in regenerative disorders.


Assuntos
Cabelo , Melanócitos , Transdução de Sinais , Animais , Camundongos , Cabelo/citologia , Cabelo/crescimento & desenvolvimento , Folículo Piloso/citologia , Folículo Piloso/fisiologia , Receptores de Hialuronatos/metabolismo , Melanócitos/citologia , Melanócitos/metabolismo , Nevo/metabolismo , Nevo/patologia , Osteopontina/metabolismo , Células-Tronco/citologia
2.
Pharmacol Res ; 199: 107049, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38159785

RESUMO

Adolescent exposure to Δ9-tetrahydrocannabinol (THC) has enduring effects on energy metabolism and immune function. Prior work showed that daily administration of a low-impact dose of THC (5 mg/kg, intraperitoneal) during adolescence alters transcription in adult microglia and disrupts their response to bacterial endotoxin or social stress. To explore the lasting impact of adolescent THC exposure on the brain's reaction to viral infection, we administered THC (5 mg/kg, intraperitoneal) in male and female mice once daily on postnatal day (PND) 30-43. When the mice reached adulthood (PND 70), we challenged them with the viral mimic, polyinosinic acid:polycytidylic acid [Poly(I:C)], and assessed sickness behavior (motor activity, body temperature) and whole brain gene transcription. Poly(I:C) caused an elevation in body temperature which was lessened by prior THC exposure in female but not male mice. Adolescent THC exposure did not affect the locomotor response to Poly(I:C) in either sex. Transcriptomic analyses showed that Poly(I:C) produced a substantial upregulation of immune-related genes in the brain, which was decreased by THC in females. Additionally, the viral mimic caused a male-selective downregulation in transcription of genes involved in neurodevelopment and synaptic transmission, which was abrogated by adolescent THC treatment. The results indicate that Poly(I:C) produces complex transcriptional alterations in the mouse brain, which are sexually dimorphic and differentially affected by early-life THC exposure. In particular, adolescent THC dampens the brain's antiviral response to Poly(I:C) in female mice and prevents the transcriptional downregulation of neuron-related genes caused by the viral mimic in male mice.


Assuntos
Dronabinol , Viroses , Animais , Camundongos , Masculino , Feminino , Dronabinol/farmacologia , Encéfalo , Transmissão Sináptica , Neurônios
3.
Small ; 19(2): e2202343, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36394151

RESUMO

Ectopic pregnancy (EP) is the leading cause of maternity-related death in the first trimester of pregnancy. Approximately 98% of ectopic implantations occur in the fallopian tube, and expedient management is crucial for preventing hemorrhage and maternal death in the event of tubal rupture. Current ultrasound strategies misdiagnose EP in up to 40% of cases, and the failure rate of methotrexate treatment for confirmed EP exceeds 10%. Here the first theranostic strategy for potential management of EP is reported using a near-infrared naphthalocyanine dye encapsulated within polymeric nanoparticles. These nanoparticles preferentially accumulate in the developing murine placenta within 24 h following systemic administration, and enable visualization of implantation sites at various gestational stages via fluorescence and photoacoustic imaging. These nanoparticles do not traverse the placental barrier to the fetus or impact fetal development. However, excitation of nanoparticles localized in specific placentas with focused NIR light generates heat (>43 °C) sufficient for disruption of placental function, resulting in the demise of targeted fetuses with no effect on adjacent fetuses. This novel approach would enable diagnostic confirmation of EP when current imaging strategies are unsuccessful, and elimination of EP could subsequently be achieved using the same nano-agent to generate localized hyperthermia resulting in targeted placental impairment.


Assuntos
Hipertermia Induzida , Gravidez Ectópica , Gravidez , Feminino , Humanos , Animais , Camundongos , Placenta/diagnóstico por imagem , Gravidez Ectópica/terapia , Tubas Uterinas/diagnóstico por imagem , Ultrassonografia
4.
Bioorg Med Chem Lett ; 90: 129325, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37182610

RESUMO

(-)-Epigallocatehin-3-gallate (EGCG) is a catechin derived from green tea, which has been widely studied for its anti-oxidant and anti-tumor properties. Although EGCG plays important roles in various biological processes, the its effect on the immune system is not fully understood. In this study, we investigated the potential of EGCG as an activator of the stimulator of interferon genes (STING) pathway in the immune system. The cyclic GMP-AMP synthase (cGAS)-2-3-cyclic GMP-AMP (cGAMP)-STING pathway is crucial in the innate immune response to microbial infections, autoimmunity, and anticancer immunity. We confirmed that EGCG enhanced the immune response of cGAMP and identified E2 from 13 synthetic derivatives of EGCG. E2 specifically activated the interferon (IFN) signaling pathway specifically through STING- and cGAMP-dependent mechanisms. These results demonstrate the potential of EGCG and its derivatives as new STING activators that can stimulate the type I interferon response by boosting cGAMP-mediated STING activity.


Assuntos
Interferon Tipo I , Nucleotídeos Cíclicos , Imunidade Inata , Interferon Tipo I/farmacologia , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Transdução de Sinais
5.
Health Commun ; 38(10): 2121-2131, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-35361028

RESUMO

This study examined the roles of normative and epistemic factors in influencing individuals' reluctance to be vaccinated during the COVID-19 pandemic. Individuals' ethical orientations (IEO; teleology vs. deontology) were introduced as normative characteristics, while COVID-19 vaccine conspiracy beliefs and vaccine knowledge were addressed as issue-specific epistemic factors. We conducted two online surveys to investigate each of these three factors' influences on the level of Americans' reluctance to receive COVID-19 vaccines. Combinations of these factors that predict COVID-19 vaccination hesitancy levels were also explored to provide integrated perspectives in the specific vaccination context. Our findings demonstrated the positive association between IEO and reluctance to receive COVID-19 vaccines. Significant interactions between 1) COVID-19 vaccine conspiracy beliefs and IEO and 2) conspiracy beliefs and vaccine knowledge were also identified. Implications, limitations, and suggestions for future study were addressed.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/uso terapêutico , Pandemias , Hesitação Vacinal , Vacinação
6.
Mol Pharm ; 19(12): 4696-4704, 2022 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-36409995

RESUMO

Recently, therapeutics based on mRNA (mRNA) have attracted significant interest for vaccines, cancer immunotherapy, and gene editing. However, the lack of biocompatible vehicles capable of delivering mRNA to the target tissue and efficiently expressing the encoded proteins impedes the development of mRNA-based therapies for a variety of diseases. Herein, we report mRNA-loaded polymeric nanoparticles based on diethylenetriamine-substituted poly(aspartic acid) that induce protein expression in the lungs and muscles following intravenous and intramuscular injections, respectively. Animal studies revealed that the amount of polyethylene glycol (PEG) on the nanoparticle surface affects the translation of the delivered mRNA into the encoded protein in the target tissue. After systemic administration, only mRNA-loaded nanoparticles modified with PEG at a molar ratio of 1:1 (PEG/polymer) induce protein expression in the lungs. In contrast, protein expression was detected only following intramuscular injection of mRNA-loaded nanoparticles with a PEG/polymer ratio of 10:1. These findings suggest that the PEG density on the surface of poly(aspartic acid)-based nanoparticles should be optimized for different delivery routes depending on the purpose of the mRNA treatment.


Assuntos
Ácido Aspártico , Nanopartículas , Animais , RNA Mensageiro/genética , Polímeros , Imunoterapia , Polietilenoglicóis
7.
Pharmacology ; 107(7-8): 423-432, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35691287

RESUMO

INTRODUCTION: Previous work suggests the existence of a paracrine signaling mechanism in which histamine released from visceral mast cells into the portal circulation contributes to fasting-induced ketogenesis by stimulating biosynthesis of the endogenous high-affinity PPAR-α agonist oleoylethanolamide (OEA). METHODS: Male C57Bl/6J mice were rendered obese by exposure to a high-fat diet (HFD; 60% fat). We measured histamine, OEA, and other fatty-acid ethanolamides by liquid-chromatography/mass spectrometry, gene transcription by RT-PCR, protein expression by ELISA, neutral lipid accumulation in the liver using Red Oil O and BODIPY staining, and collagen levels using picrosirius red staining. RESULTS: Long-term exposure to HFD suppressed both fasting-induced histamine release into portal blood and histamine-dependent OEA production in the liver. Additionally, subchronic OEA administration reduced lipid accumulation, inflammatory responses, and fibrosis in the liver of HFD-exposed mice. DISCUSSION: The results suggest that disruption of histamine-dependent OEA signaling in the liver might contribute to pathology in obesity-associated liver steatosis.


Assuntos
Histamina , PPAR alfa , Animais , Dieta Hiperlipídica/efeitos adversos , Endocanabinoides/metabolismo , Histamina/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Ácidos Oleicos , PPAR alfa/genética
8.
Int J Mol Sci ; 22(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198522

RESUMO

We synthesized phenylboronic acid pinacol ester (PBPE)-conjugated hyaluronic acid (HA) via thiobis(ethylamine) (TbEA) linkage (abbreviated as HAsPBPE conjugates) to fabricate the radiosensitive delivery of caffeic acid phenetyl ester (CAPE) and for application in radioprotection. PBPE was primarily conjugated with TbEA and then PBPE-TbEA conjugates were conjugated again with hyaluronic acid using carbodiimide chemistry. CAPE-incorporated nanoparticles of HAsPBPE were fabricated by the nanoprecipitation method and then the organic solvent was removed by dialysis. CAPE-incorporated HAsPBPE nanoparticles have a small particle size of about 80 or 100 nm and they have a spherical shape. When CAPE-incorporated HAsPBPE nanoparticles were irradiated, nanoparticles became swelled or disintegrated and their morphologies were changed. Furthermore, the CAPE release rate from HAsPBPE nanoparticles were increased according to the radiation dose, indicating that CAPE-incorporated HAsPBPE nanoparticles have radio-sensitivity. CAPE and CAPE-incorporated HAsPBPE nanoparticles appropriately prevented radiation-induced cell death and suppressed intracellular accumulation of reactive oxygen species (ROS). CAPE and CAPE-incorporated HAsPBPE nanoparticles efficiently improved survivability of mice from radiation-induced death and reduced apoptotic cell death. We suggest that HAsPBPE nanoparticles are promising candidates for the radio-sensitive delivery of CAPE.


Assuntos
Ácidos Borônicos/química , Ácidos Cafeicos/farmacologia , Glicóis/química , Ácido Hialurônico/química , Nanopartículas/química , Álcool Feniletílico/análogos & derivados , Proteção Radiológica , Animais , Ácidos Borônicos/síntese química , Ácidos Cafeicos/síntese química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Peróxido de Hidrogênio/toxicidade , Fígado/metabolismo , Camundongos Endogâmicos BALB C , Nanopartículas/ultraestrutura , Tamanho da Partícula , Álcool Feniletílico/síntese química , Álcool Feniletílico/farmacologia , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier
9.
Medicina (Kaunas) ; 57(6)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201046

RESUMO

Background and objectives: NELL-1 is a competent growth factor and it reported to target cells committed to the osteochondral lineage. The secreted, osteoinductive glycoproteins are reported to rheostatically control skeletal ossification. This study was performed to determine the effects of NELL-1 on spheroid morphology and cell viability and the promotion of osteogenic differentiation of stem cell spheroids. Materials and Methods: Cultures of stem cell spheroids of gingiva-derived stem cells were grown in the presence of NELL-1 at concentrations of 1, 10, 100, and 500 ng/mL. Evaluations of cell morphology were performed using a microscope, and cell viability was assessed using a two-color assay and Cell Counting Kit-8. Evaluation of the activity of alkaline phosphatase and calcium deposition assays involved anthraquinone dye assay to determine the level of osteogenic differentiation of cell spheroids treated with NELL-1. Real-time quantitative polymerase chain reaction (qPCR) was used to evaluate the expressions of RUNX2, BSP, OCN, COL1A1, and ß-actin mRNAs. Results: The applied stem cells produced well-formed spheroids, and the addition of NELL-1 at tested concentrations did not show any apparent changes in spheroid shape. There were no significant changes in diameter with addition of NELL-1 at 0, 1, 10, 100, and 500 ng/mL concentrations. The quantitative cell viability results derived on Days 1, 3, and 7 did not show significant disparities among groups (p > 0.05). There was statistically higher alkaline phosphatase activity in the 10 ng/mL group compared with the unloaded control on Day 7 (p < 0.05). A significant increase in anthraquinone dye staining was observed with the addition of NELL-1, and the highest value was noted at 10 ng/mL (p < 0.05). qPCR results demonstrated that the mRNA expression levels of RUNX2 and BSP were significantly increased when NELL-1 was added to the culture. Conclusions: Based on these findings, we conclude that NELL-1 can be applied for increased osteogenic differentiation of stem cell spheroids.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Osteogênese , Células-Tronco , Fosfatase Alcalina/genética , Diferenciação Celular , Células Cultivadas , Humanos , Osteogênese/genética , RNA Mensageiro/genética
10.
Small ; 16(18): e1906936, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32250034

RESUMO

Endometriosis is a painful disorder where endometrium-like tissue forms lesions outside of the uterine cavity. Intraoperative identification and removal of these lesions are difficult. This study presents a nanoplatform that concurrently delineates and ablates endometriosis tissues using real-time near-infrared (NIR) fluorescence and photothermal therapy (PTT). The nanoplatform consists of a dye, silicon naphthalocyanine (SiNc), capable of both NIR fluorescence imaging and PTT, and a polymeric nanoparticle as a SiNc carrier to endometriosis tissue following systemic administration. To achieve high contrast during fluorescence imaging of endometriotic lesions, nanoparticles are constructed to be non-fluorescent prior to internalization by endometriosis cells. In vitro studies confirm that these nanoparticles activate the fluorescence signal following internalization in macaque endometrial stromal cells and ablate them by increasing cellular temperature to 53 ° C upon interaction with NIR light. To demonstrate in vivo efficiency of the nanoparticles, biopsies of endometrium and endometriosis from rhesus macaques are transplanted into immunodeficient mice. Imaging with the intraoperative Fluobeam 800 system reveals that 24 h following intravenous injection, nanoparticles efficiently accumulate in, and demarcate, endometriotic grafts with fluorescence. Finally, the nanoparticles increase the temperature of endometriotic grafts up to 47 °C upon exposure to NIR light, completely eradicating them after a single treatment.


Assuntos
Endometriose , Hipertermia Induzida , Nanopartículas , Fototerapia , Animais , Endometriose/diagnóstico por imagem , Endometriose/terapia , Feminino , Humanos , Macaca mulatta , Camundongos , Imagem Óptica
11.
Proc Natl Acad Sci U S A ; 114(35): E7218-E7225, 2017 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-28808036

RESUMO

Patients with cleft lip and/or palate (CLP), who undergo numerous medical interventions from infancy, can suffer from lifelong debilitation caused by underdeveloped maxillae. Conventional treatment approaches use maxillary expansion techniques to develop normal speech, achieve functional occlusion for nutrition intake, and improve esthetics. However, as patients with CLP congenitally lack bone in the cleft site with diminished capacity for bone formation in the expanded palate, more than 80% of the patient population experiences significant postexpansion relapse. While such relapse has been a long-standing battle in craniofacial care of patients, currently there are no available strategies to address this pervasive problem. Estrogen, 17ß-estradiol (E2), is a powerful therapeutic agent that plays a critical role in bone homeostasis. However, E2's clinical application is less appreciated due to several limitations, including its pleiotropic effects and short half-life. Here, we developed a treatment strategy using an injectable system with photo-cross-linkable hydrogel (G) and nanodiamond (ND) technology to facilitate the targeted and sustained delivery of E2 to promote bone formation. In a preclinical expansion/relapse model, this functionalized E2/ND/G complex substantially reduced postexpansion relapse by nearly threefold through enhancements in sutural remodeling compared with unmodified E2 administration. The E2/ND/G group demonstrated greater bone volume by twofold and higher osteoblast number by threefold, compared with the control group. The E2/ND/G platform maximized the beneficial effects of E2 through its extended release with superior efficacy and safety at the local level. This broadly applicable E2 delivery platform shows promise as an adjuvant therapy in craniofacial care of patients.


Assuntos
Estrogênios/farmacologia , Nanodiamantes/uso terapêutico , Técnica de Expansão Palatina/instrumentação , Animais , Fenda Labial/cirurgia , Fissura Palatina/terapia , Modelos Animais de Doenças , Feminino , Hidrogel de Polietilenoglicol-Dimetacrilato/farmacologia , Nanoestruturas/uso terapêutico , Ratos , Ratos Sprague-Dawley , Recidiva , Prevenção Secundária/métodos , Resultado do Tratamento
12.
Int J Mol Sci ; 21(1)2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31948013

RESUMO

Stem cells secrete numerous paracrine factors, such as cytokines, growth factors, and extracellular vesicles. As a kind of extracellular vesicle (EV), exosomes produced in the endosomal compartment of eukaryotic cells have recently emerged as a biomedical material for regenerative medicine, because they contain many valuable contents that are derived from the host cells, and can stably deliver those contents to other recipient cells. Although we have previously demonstrated the beneficial effects of human induced potent stem cell-derived exosomes (iPSC-Exo) on the aging of skin fibroblasts, low production yield has remained an obstacle for clinical applications. In this study, we generated cell-engineered nanovesicles (CENVs) by serial extrusion of human iPSCs through membrane filters with diminishing pore sizes, and explored whether the iPSC-CENV ameliorates physiological alterations of human dermal fibroblasts (HDFs) that occur by natural senescence. The iPSC-CENV exhibited similar characteristics to the iPSC-Exo, while the production yield was drastically increased compared to that of iPSC-derived EVs, including exosomes. The proliferation and migration of both young and senescent HDFs were stimulated by the treatment with iPSC-CENVs. In addition, it was revealed that the iPSC-CNEV restored senescence-related alterations of gene expression. Treatment with iPSC-CENVs significantly reduced the activity of senescence-associated-ß-galactosidase (SA-ß-Gal) in senescent HDFs, as well as suppressing the elevated expression of p53 and p21, key factors involved in cell cycle arrest, apoptosis, and cellular senescence signaling pathways. Taken together, these results suggest that iPSC-CENV could provide an excellent alternative to iPSC-exo, and be exploited as a resource for the treatment of signs of skin aging.


Assuntos
Senescência Celular/efeitos dos fármacos , Exossomos/metabolismo , Fibroblastos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Nanopartículas/metabolismo , Engenharia Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Senescência Celular/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Fibroblastos/efeitos dos fármacos , Humanos , Microscopia Eletrônica de Transmissão , Nanopartículas/uso terapêutico , Nanopartículas/ultraestrutura , Envelhecimento da Pele/efeitos dos fármacos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
13.
Int J Mol Sci ; 19(10)2018 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-30322210

RESUMO

Distal-less homeobox 5 (Dlx5) is a negative regulator of adipogenesis. Dlx5 expression is decreased by adipogenic stimuli, but the mechanisms of Dlx5 downregulation by adipogenic stimuli have not yet been determined. Here, we tested the impact of cAMP/PKA (protein kinase A) signaling induced by 3-isobutyl-1 methyl xanthine (IBMX), forskolin, and 8-CPT-cAMP on the expression of Dlx5 in 3T3-L1 preadipocytes. Significant downregulation of Dlx5 mRNA expression and protein production levels were observed via cAMP/PKA-dependent signaling. Forced expression of cAMP-responsive element-binding protein (CREB) and CCAAT/enhancer-binding protein ß (C/EBPß) was sufficient for downregulation of Dlx5 expression and revealed that CREB functions upstream of C/EBPß. In addition, C/EBPß knockdown by siRNA rescued Dlx5 expression in IBMX-treated 3T3-L1 preadipocytes. Luciferase assays using a Dlx5-luc-2935 reporter construct demonstrated the requirement of the Dlx5 promoter region, ranging from -774 to -95 bp that contains two putative C/EBPß binding elements (site-1: -517 to -510 bp and site-2: -164 to -157 bp), in the suppression of Dlx5 transcription. Consequently, chromatin immunoprecipitation analysis confirmed the importance of site-1, but not site-2, in C/EBPß binding and transcriptional suppression of Dlx5. In conclusion, we elucidated the underling mechanism of Dlx5 downregulation in IBMX-induced adipogenesis. IBMX activated cAMP/PKA/CREB signaling and subsequently upregulated C/EBPß, which binds to the Dlx5 promoter to suppress Dlx5 transcription.


Assuntos
Adipócitos/citologia , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Homeodomínio/genética , 1-Metil-3-Isobutilxantina/farmacologia , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adipogenia , Animais , Sítios de Ligação , Proteína beta Intensificadora de Ligação a CCAAT/genética , Colforsina/farmacologia , AMP Cíclico/análogos & derivados , AMP Cíclico/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/metabolismo , Camundongos , Transdução de Sinais/efeitos dos fármacos , Tionucleotídeos/farmacologia
14.
Stem Cells ; 34(3): 711-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26485430

RESUMO

The high prevalence of cartilage diseases and limited treatment options create a significant biomedical burden. Due to the inability of cartilage to regenerate itself, introducing chondrocyte progenitor cells to the affected site is of significant interest in cartilage regenerative therapies. Tissue engineering approaches using human mesenchymal stem cells (MSCs) are promising due to their chondrogenic potential, but a comprehensive understanding of the mechanisms governing the fate of MSCs is required for precise therapeutic applications in cartilage regeneration. TGF-ß is known to induce chondrogenesis by activating SMAD signaling pathway and upregulating chondrogenic genes such as SOX9; however, the epigenetic regulation of TGF-ß-mediated chondrogenesis is not understood. In this report, we found that TGF-ß dramatically induced the expression of KDM4B in MSCs. When KDM4B was overexpressed, chondrogenic differentiation was significantly enhanced while KDM4B depletion by shRNA led to a significant reduction in chondrogenic potential. Mechanistically, upon TGF-ß stimulation, KDM4B was recruited to the SOX9 promoter, removed the silencing H3K9me3 marks, and activated the transcription of SOX9. Furthermore, KDM4B depletion reduced the occupancy of SMAD3 in the SOX9 promoter, suggesting that KDM4B is required for SMAD-dependent coactivation of SOX9. Our results demonstrate the critical role of KDM4B in the epigenetic regulation of TGF-ß-mediated chondrogenic differentiation of MSCs. Since histone demethylases are chemically modifiable, KDM4B may be a novel therapeutic target in cartilage regenerative therapy.


Assuntos
Diferenciação Celular/genética , Condrogênese/genética , Histona Desmetilases com o Domínio Jumonji/biossíntese , Células-Tronco Mesenquimais , Fatores de Transcrição SOX9/biossíntese , Fator de Crescimento Transformador beta/genética , Cartilagem/crescimento & desenvolvimento , Cartilagem/metabolismo , Linhagem Celular , Condrócitos/citologia , Epigênese Genética/genética , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Osteogênese/genética , Regiões Promotoras Genéticas , Regeneração , Fatores de Transcrição SOX9/genética , Transdução de Sinais/genética , Proteína Smad3/genética
15.
J Cell Biochem ; 116(12): 2849-57, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26015066

RESUMO

Bone morphogenetic protein (BMP) and canonical Wnts are representative developmental signals that enhance osteoblast differentiation and bone formation. Previously, we demonstrated that epidermal growth factor (EGF) inhibits BMP2-induced osteoblast differentiation by inducing Smurf1 expression. However, the regulatory role of EGF in Wnt/ß-catenin-induced osteoblast differentiation has not been elucidated. In this study, we investigated the effect of EGF on Wnt/ß-catenin signaling-induced osteoblast differentiation using the C2C12 cell line. EGF significantly suppressed the expression of osteoblast marker genes, which were induced by Wnt3a and a GSK-3ß inhibitor. EGF increased the expression levels of Smurf1 mRNA and protein. Smurf1 knockdown rescued Wnt/ß-catenin-induced osteogenic marker gene expression in the presence of EGF. EGF treatment or Smurf1 overexpression did not affect ß-catenin mRNA expression levels, but reduced ß-catenin protein levels and TOP-Flash activity. EGF and Smurf1 promoted ß-catenin ubiquitination. Co-immunoprecipitation and GST pull-down assays showed that Smurf1 associates with ß-catenin. These results suggest that EGF/Smurf1 inhibits Wnt/ß-catenin-induced osteogenic differentiation and that Smurf1 downregulates Wnt/ß-catenin signaling by enhancing proteasomal degradation of ß-catenin.


Assuntos
Diferenciação Celular/genética , Fator de Crescimento Epidérmico/biossíntese , Proteólise , Ubiquitina-Proteína Ligases/metabolismo , beta Catenina/metabolismo , Fator de Crescimento Epidérmico/genética , Regulação da Expressão Gênica no Desenvolvimento , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta , Células HEK293 , Humanos , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteogênese/genética , RNA Mensageiro/biossíntese , Ubiquitina-Proteína Ligases/genética , Via de Sinalização Wnt/genética , Proteína Wnt3A/antagonistas & inibidores , beta Catenina/genética
16.
Exp Cell Res ; 323(2): 276-87, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24631292

RESUMO

It has been demonstrated that epidermal growth factor (EGF) plays a role in supporting the proliferation of bone marrow stromal cells in bone but inhibits their osteogenic differentiation. However, the mechanism underlying EGF inhibition of osteoblast differentiation remains unclear. Smurf1 is an E3 ubiquitin ligase that targets Smad1/5 and Runx2, which are critical transcription factors for bone morphogenetic protein 2 (BMP2)-induced osteoblast differentiation. In this study, we investigated the effect of EGF on the expression of Smurf1, and the role of Smurf1 in EGF inhibition of osteogenic differentiation using C2C12 cells, a murine myoblast cell line. EGF increased Smurf1 expression, which was blocked by inhibiting the activity of either JNK or ERK. Chromatin immunoprecipitation and Smurf1 promoter assays demonstrated that c-Jun and Runx2 play roles in the EGF induction of Smurf1 transcription. EGF suppressed BMP2-induced expression of osteogenic marker genes, which were rescued by Smurf1 knockdown. EGF downregulated the protein levels of Runx2 and Smad1 in a proteasome-dependent manner. EGF decreased the transcriptional activity of Runx2 and Smurf1, which was partially rescued by Smurf1 silencing. Taken together, these results suggest that EGF increases Smurf1 expression via the activation of JNK and ERK and the subsequent binding of c-Jun and Runx2 to the Smurf1 promoter and that Smurf1 mediates the inhibitory effect of EGF on BMP2-induced osteoblast differentiation.


Assuntos
Diferenciação Celular , Proteína Básica Maior de Eosinófilos/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Osteoblastos/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Linhagem Celular , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Proteína Básica Maior de Eosinófilos/genética , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Camundongos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteogênese , Inibidores de Proteínas Quinases/farmacologia , Proteína Smad1/genética , Proteína Smad1/metabolismo , Transcrição Gênica , Ubiquitina-Proteína Ligases/genética
17.
Arch Phys Med Rehabil ; 96(11): 2033-40.e1, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26254953

RESUMO

OBJECTIVE: To investigate the effects of a 6-week indoor hand-bike exercise program on fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) levels and physical fitness in people with spinal cord injury (SCI). DESIGN: Randomized controlled trial. SETTING: National rehabilitation center (outpatient). PARTICIPANTS: Participants with SCI (N=15; exercise group: n=8, control group: n=7). INTERVENTIONS: This study involved 60-minute exercise sessions on an indoor hand-bike. Participants in the exercise group exercised 3 times per week for 6 weeks. MAIN OUTCOME MEASURES: Health parameters (body mass index [BMI], waist circumference, percent body fat, insulin level, and HOMA-IR level) and fitness outcomes (peak oxygen consumption [Vo2peak], shoulder abduction and adduction, shoulder flexion and extension, and elbow flexion and extension). RESULTS: Participation in a 6-week exercise program using an indoor hand-bike significantly decreased BMI (baseline: 22.0±3.7 m/kg(2) vs postintervention: 21.7±3.5 m/kg(2), P=.028), fasting insulin (baseline: 5.4±2.9 µU/mL vs postintervention: 3.4±1.5 µU/mL, P=.036), and HOMA-IR (baseline: 1.0±0.6 vs postintervention: 0.6±0.3, P=.03) levels compared with those in the control group. Furthermore, this training program significantly increased Vo2peak and strength in shoulder abduction, adduction, flexion, and extension and elbow flexion and extension compared with those in the control group. CONCLUSIONS: Exercise using an indoor hand-bike appears to be an effective modality to improve body composition, fasting insulin, and HOMA-IR levels and fitness in people with an SCI.


Assuntos
Ciclismo/fisiologia , Terapia por Exercício/métodos , Aptidão Física/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/reabilitação , Adulto , Glicemia , Índice de Massa Corporal , Pesos e Medidas Corporais , Feminino , Humanos , Insulina/sangue , Lipídeos/sangue , Masculino , Força Muscular , Consumo de Oxigênio , Amplitude de Movimento Articular , Centros de Reabilitação
18.
J Nanosci Nanotechnol ; 14(12): 9470-6, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25971085

RESUMO

Pulse-biased plasma etching of various dielectric layers is investigated for patterning nano-scale, multi-level resist (MLR) structures composed of multiple layers via dual-frequency, capacitively-coupled plasmas (CCPs). We compare the effects of pulse and continuous-wave (CW) biasing on the etch characteristics of a Si3N4 layer in CF4/CH2F2/O2/Aretch chemistries using a dual-frequency, superimposed CCP system. Pulse-biasing conditions using a low-frequency power source of 2 MHz were varied by controlling duty ratio, period time, power, and the gas flow ratio in the plasmas generated by the 27.12 MHz high-frequency power source. Application of pulse-biased plasma etching significantly affected the surface chemistry of the etched Si3N4 surfaces, and thus modified the etching characteristics of the Si3N4 layer. Pulse-biased etching was successfully applied to patterning of the nano-scale line and space pattern of Si3N4 in the MLR structure of KrF photoresist/bottom anti-reflected coating/SiO2/amorphous carbon layer/Si3N4. Pulse-biased etching is useful for tuning the patterning of nano-scale dielectric hard-mask layers in MLR structures.


Assuntos
Nanotecnologia , Gases em Plasma , Compostos de Silício/química
19.
J Phys Ther Sci ; 26(11): 1745-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25435691

RESUMO

[Purpose] Cerebral palsy is a disorder that affects balance in the sitting position. Cerebral palsy patients need trunk muscle strengthening and balance training. In order to improve trunk control sensory-motor control training is carried out on an unstable surface. We have developed a Trunk Training System (TTS) that can provide visual feedback using a tilt sensor for balance training in the sitting position. Before using the TTS for training children with cerebral palsy experiments were conducted with healthy adult subjects and the TTS to gather basic data for its improvement. [Subjects] The subjects were 11 healthy men (n=3) and women (n=8). [Methods] Subjects trained at two levels (5°, 10°), in four different directions (anterior, posterior, left, right), three times each. TTS outcome indices (stability index, performance time) were measured. [Results] The stability index and performance time showed high correlation (-0.6

20.
Nat Commun ; 15(1): 1705, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38402219

RESUMO

Circulating monocytes participate in pain chronification but the molecular events that cause their deployment are unclear. Using a mouse model of hyperalgesic priming (HP), we show that monocytes enable progression to pain chronicity through a mechanism that requires transient activation of the hydrolase, N-acylethanolamine acid amidase (NAAA), and the consequent suppression of NAAA-regulated lipid signaling at peroxisome proliferator-activated receptor-α (PPAR-α). Inhibiting NAAA in the 72 hours following administration of a priming stimulus prevented HP. This effect was phenocopied by NAAA deletion and depended on PPAR-α recruitment. Mice lacking NAAA in CD11b+ cells - monocytes, macrophages, and neutrophils - were resistant to HP induction. Conversely, mice overexpressing NAAA or lacking PPAR-α in the same cells were constitutively primed. Depletion of monocytes, but not resident macrophages, generated mice that were refractory to HP. The results identify NAAA-regulated signaling in monocytes as a control node in the induction of HP and, potentially, the transition to pain chronicity.


Assuntos
Amidoidrolases , Monócitos , Humanos , Inibidores Enzimáticos/farmacologia , Hiperalgesia/genética , Lipídeos , Dor , PPAR alfa , Animais , Camundongos
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