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1.
J Contemp Dent Pract ; 21(7): 776-780, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33020362

RESUMO

AIM: To evaluate the ability of osteogenic culture media in comparison with regular growth culture media in enhancing the osteoblastic cell differentiation of human periodontal ligament stem cells (hPDLSCs). MATERIALS AND METHODS: In vitro cultures of commercially obtained hPDLSCs were seeded onto xenograft bone blocks in both regular and osteogenic media. Confocal laser microscope images were obtained for cellular differentiation and adhesion, and scanning electron microscopy (SEM) images were obtained to validate the osteogenic differentiation by showing the morphological characteristics of the newly formed cells. RESULTS: Confocal laser microscope analysis showed positive staining for new bone cells with an increased signal intensity when samples were cultured in osteogenic culture media compared with regular culture media. These findings indicate the effect of the active ingredients of the osteogenic culture media in enhancing the osteogenic differentiation hPDLSC. Scanning electron microscopy images validated the osteogenic differentiation showing a flattened, polygonal morphology with multiple extending cytoplasmic processes of new cells. CONCLUSION: Xenograft bone blocks are biocompatible scaffold for the osteogenic differentiation of seeded hPDLSCs. Osteogenic culture media enhances and increases the osteogenic differentiation of hPDLSCs into new bone cells more than regular growth culture media. Periodontal ligament stem cells are a predictable biological input as a cell-based tissue-engineered construct and biologically acceptable when it is cultured in a suitable growth media that mimics the intended environment. CLINICAL SIGNIFICANCE: Consideration of the clinical use of equine bone blocks and periodontal ligament stem cells in a suitable biological environment as a potential new option for bone regeneration techniques.


Assuntos
Osteogênese , Ligamento Periodontal , Animais , Células Cultivadas , Meios de Cultura , Cavalos , Humanos , Microscopia Eletrônica de Varredura , Células-Tronco
2.
Aquat Toxicol ; 227: 105586, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32882451

RESUMO

Estrogenic effects triggered by androgens have been previously shown in a few studies. Aromatization and direct binding to estrogen receptors (ERs) are the most proposed mechanisms. For example, previously, a modulation of vitellogenin A (VtgA) by testosterone (T), an aromatizable androgen, was reported in brown trout primary hepatocytes. The effect was reversed by an ER antagonist. In this study, using the same model the disruption caused by T and by the non-aromatizable androgen - dihydrotestosterone (DHT), was assessed in selected estrogenic targets. Hepatocytes were exposed (96 h) to six concentrations of each androgen. The estrogenic targets were VtgA, ERα, ERß1 and two zona pellucida genes, ZP2.5 and ZP3a.2. The aromatase CYP19a1 gene and the androgen receptor (AR) were also included. Modulation of estrogenic targets was studied by quantitative real-time PCR and immunohistochemistry, using an HScore system. VtgA and ERα were up-regulated by DHT (1, 10, 100 µM) and T (10, 100 µM). In contrast, ERß1 was down-regulated by DHT (10, 100 µM), and T (100 µM). ZP2.5 mRNA levels were increased by DHT and T (1, 10, 100 µM), while ZP3a.2 was up-regulated by DHT (100 µM) and T (10, 100 µM). Positive correlations were found between VtgA and ERα mRNA levels and ZPs and ERα, after exposure to both androgens. The mRNA levels of CYP19a1 were not changed, while AR expression tended to increase after micromolar DHT exposures. HScores for Vtg and ZPs corroborated the molecular findings. Both androgens triggered estrogen signaling through direct binding to ERs, most probably ERα.


Assuntos
Androgênios/toxicidade , Di-Hidrotestosterona/toxicidade , Estrogênios/metabolismo , Hepatócitos/efeitos dos fármacos , Testosterona/toxicidade , Truta/metabolismo , Poluentes Químicos da Água/toxicidade , Androgênios/metabolismo , Animais , Células Cultivadas , Di-Hidrotestosterona/metabolismo , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/genética , Receptor beta de Estrogênio/metabolismo , Estrogênios/genética , Expressão Gênica/efeitos dos fármacos , Hepatócitos/metabolismo , Masculino , Cultura Primária de Células , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Testosterona/metabolismo , Vitelogeninas/genética , Vitelogeninas/metabolismo , Poluentes Químicos da Água/metabolismo
3.
Nat Commun ; 11(1): 4826, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958757

RESUMO

DNA replication initiates from multiple genomic locations called replication origins. In metazoa, DNA sequence elements involved in origin specification remain elusive. Here, we examine pluripotent, primary, differentiating, and immortalized human cells, and demonstrate that a class of origins, termed core origins, is shared by different cell types and host ~80% of all DNA replication initiation events in any cell population. We detect a shared G-rich DNA sequence signature that coincides with most core origins in both human and mouse genomes. Transcription and G-rich elements can independently associate with replication origin activity. Computational algorithms show that core origins can be predicted, based solely on DNA sequence patterns but not on consensus motifs. Our results demonstrate that, despite an attributed stochasticity, core origins are chosen from a limited pool of genomic regions. Immortalization through oncogenic gene expression, but not normal cellular differentiation, results in increased stochastic firing from heterochromatin and decreased origin density at TAD borders.


Assuntos
DNA/biossíntese , DNA/química , Origem de Replicação/genética , Animais , Composição de Bases , Sequência de Bases , Carcinogênese , Diferenciação Celular , Células Cultivadas , Replicação do DNA/genética , Genoma Humano/genética , Heterocromatina/genética , Humanos , Camundongos , Motivos de Nucleotídeos , Transcrição Genética
4.
Nat Commun ; 11(1): 4765, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958780

RESUMO

Fatty acids (FAs) are essential nutrients, but how they are transported into cells remains unclear. Here, we show that FAs trigger caveolae-dependent CD36 internalization, which in turn delivers FAs into adipocytes. During the process, binding of FAs to CD36 activates its downstream kinase LYN, which phosphorylates DHHC5, the palmitoyl acyltransferase of CD36, at Tyr91 and inactivates it. CD36 then gets depalmitoylated by APT1 and recruits another tyrosine kinase SYK to phosphorylate JNK and VAVs to initiate endocytic uptake of FAs. Blocking CD36 internalization by inhibiting APT1, LYN or SYK abolishes CD36-dependent FA uptake. Restricting CD36 at either palmitoylated or depalmitoylated state eliminates its FA uptake activity, indicating an essential role of dynamic palmitoylation of CD36. Furthermore, blocking endocytosis by targeting LYN or SYK inhibits CD36-dependent lipid droplet growth in adipocytes and high-fat-diet induced weight gain in mice. Our study has uncovered a dynamic palmitoylation-regulated endocytic pathway to take up FAs.


Assuntos
Antígenos CD36/metabolismo , Endocitose/fisiologia , Ácidos Graxos/metabolismo , Lipoilação , Células 3T3-L1 , Aciltransferases/metabolismo , Adipócitos/metabolismo , Animais , Antígenos CD36/deficiência , Antígenos CD36/genética , Cavéolas/metabolismo , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Humanos , Gotículas Lipídicas/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Obesidade/tratamento farmacológico , Fosforilação , Transdução de Sinais , Quinase Syk/antagonistas & inibidores , Quinase Syk/metabolismo , Ganho de Peso/efeitos dos fármacos , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismo
5.
Am J Physiol Lung Cell Mol Physiol ; 319(4): L670-L674, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32878480

RESUMO

The severity of coronavirus disease 2019 (COVID-19) is linked to an increasing number of risk factors, including exogenous (environmental) stimuli such as air pollution, nicotine, and cigarette smoke. These three factors increase the expression of angiotensin I converting enzyme 2 (ACE2), a key receptor involved in the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-the etiological agent of COVID-19-into respiratory tract epithelial cells. Patients with severe COVID-19 are managed with oxygen support, as are at-risk individuals with chronic lung disease. To date, no study has examined whether an increased fraction of inspired oxygen (FiO2) may affect the expression of SARS-CoV-2 entry receptors and co-receptors, including ACE2 and the transmembrane serine proteases TMPRSS1, TMPRSS2, and TMPRSS11D. To address this, steady-state mRNA levels for genes encoding these SARS-CoV-2 receptors were assessed in the lungs of mouse pups chronically exposed to elevated FiO2, and in the lungs of preterm-born human infants chronically managed with an elevated FiO2. These two scenarios served as models of chronic elevated FiO2 exposure. Additionally, SARS-CoV-2 receptor expression was assessed in primary human nasal, tracheal, esophageal, bronchial, and alveolar epithelial cells, as well as primary mouse alveolar type II cells exposed to elevated oxygen concentrations. While gene expression of ACE2 was unaffected, gene and protein expression of TMPRSS11D was consistently upregulated by exposure to an elevated FiO2. These data highlight the need for further studies that examine the relative contribution of the various viral co-receptors on the infection cycle, and point to oxygen supplementation as a potential risk factor for COVID-19.


Assuntos
Infecções por Coronavirus/patologia , Proteínas de Membrana/metabolismo , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/patologia , Mucosa Respiratória/metabolismo , Serina Endopeptidases/metabolismo , Serina Proteases/metabolismo , Células Epiteliais Alveolares/metabolismo , Animais , Betacoronavirus , Células Cultivadas , Feminino , Humanos , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Oxigênio/administração & dosagem , Oxigênio/análise , Pandemias , Receptores Virais/metabolismo , Fatores de Risco , Serina Endopeptidases/genética , Serina Proteases/genética , Índice de Gravidade de Doença
6.
Int J Oral Maxillofac Implants ; 35(5): 939-947, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32991644

RESUMO

PURPOSE: This study investigated the effects of bisphosphonates, namely, alendronate and zoledronate, on the osteogenic activity of osteoprogenitor cells cultured on titanium surfaces at therapeutic doses in order to assess if altered osteoblastogenesis could compromise osseointegration and contribute to etiopathogenesis of painful disorders such as bisphosphonates-related osteonecrosis of the jaw (BRONJ) following implant placement. MATERIALS AND METHODS: MC3T3-E1 Subclone 4 cells were utilized in this study. Therapeutic doses of alendronate and zoledronate were calculated based on reported peak plasma concentrations. The viability, proliferation, adhesion, and mineralization potential of cells was assessed using a LIVE/DEAD stain, alamarBlue assay, immunofluorescence microscopy, and Alizarin Red S staining, respectively. RESULTS: Therapeutic doses of zoledronate negatively affected cell viability, whereas therapeutic doses of alendronate significantly enhanced cell differentiation and the amount of bone formation compared with the control. CONCLUSION: The findings of this study may provide some insight into the pathogenesis of BRONJ development following implant placement in patients treated with zoledronate and may have promising implications toward improved wound healing and osseointegration in patients treated with alendronate.


Assuntos
Difosfonatos/efeitos adversos , Osteogênese , Alendronato , Células Cultivadas , Humanos , Titânio
7.
Nat Commun ; 11(1): 4413, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32887883

RESUMO

The molecular signatures of cells in the brain have been revealed in unprecedented detail, yet the ageing-associated genome-wide expression changes that may contribute to neurovascular dysfunction in neurodegenerative diseases remain elusive. Here, we report zonation-dependent transcriptomic changes in aged mouse brain endothelial cells (ECs), which prominently implicate altered immune/cytokine signaling in ECs of all vascular segments, and functional changes impacting the blood-brain barrier (BBB) and glucose/energy metabolism especially in capillary ECs (capECs). An overrepresentation of Alzheimer disease (AD) GWAS genes is evident among the human orthologs of the differentially expressed genes of aged capECs, while comparative analysis revealed a subset of concordantly downregulated, functionally important genes in human AD brains. Treatment with exenatide, a glucagon-like peptide-1 receptor agonist, strongly reverses aged mouse brain EC transcriptomic changes and BBB leakage, with associated attenuation of microglial priming. We thus revealed transcriptomic alterations underlying brain EC ageing that are complex yet pharmacologically reversible.


Assuntos
Envelhecimento/patologia , Barreira Hematoencefálica , Encéfalo/fisiopatologia , Células Endoteliais/metabolismo , Exenatida/farmacologia , Doença de Alzheimer/fisiopatologia , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/fisiopatologia , Capilares/metabolismo , Células Cultivadas , Humanos , Camundongos , Microglia/efeitos dos fármacos , Doenças Neurodegenerativas/fisiopatologia , Transcriptoma/efeitos dos fármacos
8.
Anim Sci J ; 91(1): e13451, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32926550

RESUMO

This study assessed the effects of cryoprotectant concentration during equilibration on the efficiency of bovine blastocyst vitrification and the expression of selected developmentally important genes. In vitro produced bovine blastocysts were equilibrated in either 7.5% ethylene glycol (EG) + 7.5% DMSO (Va group) or in 2% EG + 2% DMSO (Vb group) then vitrified on Cryotop® sheets in 16.5% EG + 16.5% DMSO + 0.5M sucrose. After warming, embryos were cultured for 48 hr. Re-expansion, hatching, and the numbers of total and membrane damaged cells were compared among vitrified groups and a control. There was no significant difference between the vitrified groups in survival, cell numbers and the extent of membrane damage. Vitrification increased the number of membrane-damaged cells in both groups, however, in a greater extent in the Vb group. Vitrification increased (p < .05) the expression of the HSP70 gene in Va but not in Vb embryos. The expression of IGF2R, SNRPN, HDAC1, DNMT3B, BAX, OCT4, and IFN-t genes were the same in control and vitrified groups. In conclusion, the concentration of cryoprotectants during equilibration did not affect survival rates; however, normal cell numbers could be maintained only by equilibration in 15% cryoprotectants which was associated with increased HSP70 expression.


Assuntos
Blastocisto , Sobrevivência Celular/efeitos dos fármacos , Criopreservação/métodos , Criopreservação/veterinária , Crioprotetores/farmacologia , Fertilização In Vitro/métodos , Fertilização In Vitro/veterinária , Vitrificação/efeitos dos fármacos , Animais , Bovinos , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Expressão Gênica , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo
9.
Braz J Med Biol Res ; 53(10): e9849, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32901689

RESUMO

Testosterone has been demonstrated to antagonize doxorubicin-induced cardiomyocyte senescence. However, whether testosterone prevents the paraquat-induced cardiomyocyte senescence is largely unknown. The detection of SA-ß-gal activity was performed using senescence ß-gal staining kit and the reactive oxygen species levels were determined by reactive oxygen species assay kit. The plasmids for insulin-like growth factor 1 shRNA (sh-mIGF-1), sirtuin-1 shRNA (sh-SIRT1), scramble shRNA (sh-NC), overexpressing mIGF-1 (mIGF-1), overexpressing SIRT1 (SIRT1), and negative controls (NC) were obtained for this study. The expression of target genes was detected using quantitative real-time PCR, immunolabeling, and western blot. We found that testosterone significantly delayed the paraquat-induced HL-1 cardiomyocyte senescence as evidenced by decreasing senescence-associated ß-galactosidase activity and reactive oxygen species generation, which were accompanied by the up-regulated expression of mIGF-1 and SIRT1. RNA interference to reduce mIGF-1 and SIRT1 expression showed that testosterone prevented paraquat-induced HL-1 senescence via the mIGF-1/SIRT1 signaling pathway. Furthermore, myocardial contraction was evaluated by expression of genes of the contractile proteins/enzymes, such as α-myosin heavy chain 6 (MHC6), α-myosin heavy chain 7 (MHC7), α-skeletal actin (ACTA-1), and sarco/endoplasmic reticulum calcium ATPase-2 (SERCA2). Testosterone adjusted the above four gene expressions and the adjustment was blocked by mIGF-1 or SIRT1 inhibition. Our findings suggested that the mIGF-1/SIRT1 signaling pathway mediated the protective function of testosterone against the HL-1 cardiomyocyte senescence by paraquat, which provided new clues for the mechanisms underlying the anti-aging role of testosterone in cardiomyocytes.


Assuntos
Miócitos Cardíacos , Paraquat/toxicidade , Sirtuína 1 , Testosterona/fisiologia , Células Cultivadas , Transdução de Sinais
11.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(4): 499-505, 2020 Apr 30.
Artigo em Chinês | MEDLINE | ID: mdl-32895132

RESUMO

OBJECTIVE: To explore the effects of olmesartan on age-associated migration and invasion capacities and microRNA (miRAN) axis in human aortic vascular smooth muscle cells (HA-VSMCs). METHODS: Cultured HA-VSMCs were divided into control group, bleomycin-mediated senescence (BLM) group and bleomycin + olmesartan treatment group. Wound-healing assay and Boyden chambers invasion assay were used to assess the changes in migration and invasion of the cells, gelatin zymography was used to analyze matrix metalloproteinase-2 (MMP-2) activation in the cells. The differentially expressed miRNAs were identified by miRNA microarray assay and validated by quantitative real-time PCR. MiR-3133 inhibitor was used to examine the effects of molecular manipulation of olmesartan on age-associated migration and invasion and MMP-2 activation in the cells. RESULTS: Compared with those of the control group, the percentage of the repopulated cells and the number of cells crossing the basement membrane increased significantly in BLM group [(78.43±12.76)% vs (42.47±7.22)%, P < 0.05; 33.33±5.51 vs 13.00±4.36, P < 0.05]. A significant increase of MMP-2 activation was found in BLM group as compared with the control group (1.66 ± 0.27 vs 0.87 ± 0.13, P < 0.05). Olmesartan significantly inhibited BLM-induced enhancement of cell migration and invasion and MMP-2 secretion in the cells. MiR-3133 was significantly downregulated in BLM group and upregulated in olmesartan group. Transfection with miR-3133 inhibitor significantly reversed the effects of olmesartan on age-associated migration and invasion of the cells [(85.87±7.39)% vs (49.77±3.05)%; 34.67±2.31 vs 20.00±4.58, P < 0.05] and MMP-2 activation in the cells (1.76±0.19 vs 0.94±0.10, P < 0.05). CONCLUSIONS: Olmesartan inhibits the migration and invasion of ageassociated HA-VSMCs probably by upregulating of the miR-3133 axis.


Assuntos
MicroRNAs/genética , Músculo Liso Vascular , Movimento Celular , Proliferação de Células , Células Cultivadas , Humanos , Imidazóis , Metaloproteinase 2 da Matriz , Miócitos de Músculo Liso , Tetrazóis
12.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(8): 1119-1126, 2020 Aug 30.
Artigo em Chinês | MEDLINE | ID: mdl-32895177

RESUMO

OBJECTIVE: To explore the effect of Danggui Niantong decoction (DGNTD) on cell apoptosis and TNF receptor super family 6 (Fas)/caspase-8 pathway in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS). METHODS: FLS isolated from the synovial tissue of RA patients were cultured and identified using immunofluorescence staining. The cells were treated with 10% blank serum (blank control group), 10% sera containing low, moderate or high doses of DGNTD, or 20 µmol/mL KR-33493 (a Fas inhibitor) combined with 10% serum containing high-dose DGNTD. MTT assay was used to detect the proliferation of the cells after the treatments. Apoptosis of the cells was detected at 48 h in each group using Hoechst 33342 staining and flow cytometry with annexin V-FITC/PI staining. The mRNA and protein expressions of Fas, FADD, caspase-8 and caspase-3 in the cells at 48 h were detected using qPCR and Western blotting. RESULTS: Immunofluorescence staining identified the cultured cells as FLS. Treatment with DGNTD-containing sera significantly inhibited the proliferation of FLS, and the inhibitory effects were enhanced as the dose and intervention time increased (P < 0.05). Hoechst 33342 staining and flow cytometry showed that the sera containing different doses of DGNTD significantly promoted apoptosis of FLS (P < 0.05). The expression levels of Fas, FADD, caspase-8, and caspase-3 at both mRNA and protein levels were significantly increased in the cells after treatment with different doses of DGNTD-containing sera (P < 0.05). The application of KR-33493 obviously reversed the effects of DGNTD on the FLS (P < 0.05). CONCLUSIONS: DGNTD can induce apoptosis of the FLS by activating Fas/caspase-8 signaling pathway.


Assuntos
Artrite Reumatoide , Sinoviócitos , Apoptose , Caspase 8 , Proliferação de Células , Células Cultivadas , Fibroblastos , Membrana Sinovial
13.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(8): 1134-1140, 2020 Aug 30.
Artigo em Chinês | MEDLINE | ID: mdl-32895184

RESUMO

OBJECTIVE: To explore whether thrombopoietin (TPO) can rescue megakaryopoiesis by protecting bone marrowderived endothelial progenitor cells (BM-EPCs) in patients receiving chemotherapy for hematological malignancies. METHODS: Bone marrow samples were collected from 23 patients with hematological malignancies 30 days after chemotherapy and from 10 healthy volunteers. BM-EPCs isolated from the samples were identified by staining for CD34, CD309 and CD133, and their proliferation in response to treatment with TPO was assessed using CCK8 assay. DiL-Ac-LDL uptake and FITC-UEA-I binding assay were performed to evaluate the amount of BM-EPCs from the subjects. Tube-formation and migration experiments were used for functional assessment of the BM-EPCs. The BM-EPCs with or without TPO treatment were co-cultured with human megakaryocytes, and the proliferation of the megakaryocytes was detected with flow cytometry. RESULTS: Flow cytometry indicated that the TPO-treated cells had high expressions of CD34, CD133, and CD309. CCK8 assay demonstrated that TPO treatment enhanced the proliferation of the BM-EPCs, and the optimal concentration of TPO was 100 µg/L. Double immunofluorescence assay indicated that the number of BM-EPC was significantly higher in TPO-treated group than in the control group. The TPO-treated BM-EPCs exhibited stronger tube-formation and migration abilities (P < 0.05) and more significantly enhanced the proliferation of co-cultured human megakaryocytes than the control cells (P < 0.05). CONCLUSIONS: TPO can directly stimulate megakaryopoiesis and reduce hemorrhage via protecting the function of BM-EPCs in patients following chemotherapy for hematological malignancies.


Assuntos
Medula Óssea , Neoplasias Hematológicas , Células da Medula Óssea , Células Cultivadas , Humanos , Megacariócitos , Trombopoetina
14.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(5): 640-646, 2020 May 30.
Artigo em Chinês | MEDLINE | ID: mdl-32897197

RESUMO

OBJECTIVE: To clarify the molecular signaling mechanism underlying the inhibitory effect of metformin on transforming growth factor-ß1 (TGF-ß1)-stimulated collagen I production in rat biliary fibroblasts. METHODS: Primary biliary fibroblasts were isolated under aseptic condition from 50 Sprague-Dawley rats (half male and half female), and microscopic observation identified no obvious difference in the morphology or viability of the cells from rats with different sexes or body weight. The cells were treated with TGF-ß1 (10 ng/mL), Smad3 siRNA+TGF-ß1, CTGF siRNA+TGF-ß1, metformin (10 mmol/L)+ TGF-ß1, or Compound C (10 µmol/L)+metformin+TGF-ß1. The expressions of CTGF and collagen I in the treated cells were determined using ELISA kit or Western blotting; the phorsphorylated and total Smad3 and AMPK expressions were detected using immunoblotting. RESULTS: TGF-ß1 time- and dose-dependently induced collagen I production in rat biliary fibroblasts. The activated AMPK by metformin dose-dependently inhibited TGF-ß1-induced collagen I production. Pre-incubation of cells with the AMPK inhibitor Compound C restored the inhibitory effect of AMPK on TGF-ß1-induced collagen I secretion (P < 0.01). Activation of AMPK by metformin significantly reduced TGF-ß1-induced collagen I production by suppressing Smad3-driven CTGF expression (P < 0.01), and the application of Compound C reversed such changes in the fibroblasts (P < 0.01). CONCLUSIONS: Metformin inhibits TGF-ß1-stimulated collagen I production by activating AMPK and inhibiting Smad3- driven CTGF expression in rat biliary fibroblasts.


Assuntos
Fibroblastos , Animais , Células Cultivadas , Colágeno , Feminino , Masculino , Metformina , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Proteína Smad3 , Fator de Crescimento Transformador beta1
15.
Nat Commun ; 11(1): 4471, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901010

RESUMO

A human cell contains hundreds to thousands of mitochondrial DNA (mtDNA) packaged into nucleoids. Currently, the segregation and allocation of nucleoids are thought to be passively determined by mitochondrial fusion and division. Here we provide evidence, using live-cell super-resolution imaging, that nucleoids can be actively transported via KIF5B-driven mitochondrial dynamic tubulation (MDT) activities that predominantly occur at the ER-mitochondria contact sites (EMCS). We further demonstrate that a mitochondrial inner membrane protein complex MICOS links nucleoids to Miro1, a KIF5B receptor on mitochondria, at the EMCS. We show that such active transportation is a mechanism essential for the proper distribution of nucleoids in the peripheral zone of the cell. Together, our work identifies an active transportation mechanism of nucleoids, with EMCS serving as a key platform for the interplay of nucleoids, MICOS, Miro1, and KIF5B to coordinate nucleoids segregation and transportation.


Assuntos
DNA Mitocondrial/metabolismo , Retículo Endoplasmático/metabolismo , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/fisiologia , Animais , Transporte Biológico Ativo , Células COS , Células Cultivadas , Chlorocebus aethiops , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Células HEK293 , Humanos , Cinesina/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Membranas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Modelos Biológicos , Ratos , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção , Proteínas rho de Ligação ao GTP/metabolismo
16.
J Toxicol Sci ; 45(9): 559-567, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879255

RESUMO

Lead is a main threat to human health due to its neurotoxicity and the astrocyte is known to be a common deposit site of lead in vivo. However, the detailed mechanisms related to lead exposure in the astrocytes were unclear. In order to deeply investigate this issue, we used Sprague-Dawley (SD) rats and astrocytes isolated from the hippocampus of SD rats to establish the lead-exposed animal and cell models through treating with lead acetate. The expression levels of GFAP, LC3, and p62 in the rat hippocampus were detected by immunofluorescence and Western blot after lead exposure. The effects of autophagy on lead-exposed astrocytes were studied by further autophagy inhibitor 3-methyladenine (3-MA) induction. Transmission electron microscopy was used to observe autophagosomes in astrocytes after lead acetate treatment, followed by assessing related autophagy protein markers. In addition, some inflammatory cytokines and oxidative stress markers were also evaluated after lead exposure and 3-MA administration. We found that lead exposure induced activation of astrocytes, as evidenced by increased GFAP levels and GFAP-positive staining cells in the rat hippocampus. Moreover, lead exposure induced autophagy in astrocytes, as evidenced by increased LC3II and Beclin 1 protein levels and decreased p62 expression in both the rat hippocampus and astrocytes, and it was confirmed that this autophagy was activated through blocking the downstream Akt/target of the rapamycin (mTOR) pathway in astrocytes. Furthermore, it was shown that treatment of lead acetate increased the release of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß), and the accumulation of malondialdehyde (MDA) and myeloperoxidase (MPO) in astrocytes, which could be alleviated by further 3-MA induction. Therefore, we conclude that lead exposure can induce the autophagy of astrocytes via blocking the Akt/mTOR pathway, leading to accelerated release of inflammatory factors and oxidative stress indicators in astrocytes.


Assuntos
Astrócitos/metabolismo , Astrócitos/fisiologia , Autofagia/efeitos dos fármacos , Autofagia/genética , Compostos Organometálicos/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Animais , Células Cultivadas , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Hipocampo/citologia , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Masculino , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Estresse Oxidativo/genética , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
17.
J Toxicol Sci ; 45(9): 569-579, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879256

RESUMO

Indoxyl, a derivative of indole originating from tryptophan, may undergo phase-II sulfate-conjugation pathway, thereby forming indoxyl sulfate (IS) in vivo. We previously reported that IS, a well-known uremic toxin, can increase the intracellular oxidation level and decrease the phagocytic activity in a differentiated HL-60 human macrophage cell model. Using the same cell model, the current study aimed to investigate whether indole and indoxyl (the metabolic precursors of indoxyl and IS, respectively) may cause macrophage immune dysfunction. Results obtained indicated that intracellular oxidation level and cytotoxicity markedly increased upon treatment with indole and indoxyl, in comparison with IS. Incubation of the cells with indole and indoxyl also resulted in attenuated phagocytic activity. Human serum albumin (HSA)-binding assay confirmed that tryptophan and IS, but not indole and indoxyl, could selectively bind to the site II in HSA. Collectively, the results indicated that indole and indoxyl may strongly down-regulate the phagocytic immune function of macrophages, whereas IS, formed upon sulfate conjugation of indoxyl, may exhibit enhanced HSA-binding capability, thereby reducing the adverse effects of indoxyl.


Assuntos
Indóis/efeitos adversos , Macrófagos/imunologia , Macrófagos/metabolismo , Oxirredução/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Fagocitose/imunologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Células HL-60 , Humanos , Indicã/metabolismo , Macrófagos/efeitos dos fármacos , Ligação Proteica , Albumina Sérica/metabolismo , Triptofano/metabolismo
18.
J Exp Med ; 217(12)2020 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-32886755

RESUMO

COVID-19 includes lung infection ranging from mild pneumonia to life-threatening acute respiratory distress syndrome (ARDS). Dysregulated host immune response in the lung is a key feature in ARDS pathophysiology. However, cellular actors involved in COVID-19-driven ARDS are poorly understood. Here, in blood and airways of severe COVID-19 patients, we serially analyzed unconventional T cells, a heterogeneous class of T lymphocytes (MAIT, γδT, and iNKT cells) with potent antimicrobial and regulatory functions. Circulating unconventional T cells of COVID-19 patients presented with a profound and persistent phenotypic alteration. In the airways, highly activated unconventional T cells were detected, suggesting a potential contribution in the regulation of local inflammation. Finally, expression of the CD69 activation marker on blood iNKT and MAIT cells of COVID-19 patients on admission was predictive of clinical course and disease severity. Thus, COVID-19 patients present with an altered unconventional T cell biology, and further investigations will be required to precisely assess their functions during SARS-CoV-2-driven ARDS.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/imunologia , Células T Invariáveis Associadas à Mucosa/metabolismo , Células T Matadoras Naturais/metabolismo , Fenótipo , Pneumonia Viral/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Síndrome do Desconforto Respiratório do Adulto/imunologia , Idoso , Antígenos CD/sangue , Antígenos de Diferenciação de Linfócitos T/sangue , Células Cultivadas , Infecções por Coronavirus/virologia , Citocinas/metabolismo , Feminino , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Lectinas Tipo C/sangue , Masculino , Pessoa de Meia-Idade , Células T Invariáveis Associadas à Mucosa/imunologia , Células T Matadoras Naturais/imunologia , Pandemias , Pneumonia Viral/virologia , Prognóstico , Estudos Prospectivos , Síndrome do Desconforto Respiratório do Adulto/virologia , Índice de Gravidade de Doença
19.
Nat Commun ; 11(1): 4367, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868763

RESUMO

Invariant natural killer T (iNKT), mucosal-associated invariant T (MAIT), and γδ T cells are innate T cells that acquire memory phenotype in the thymus and share similar biological characteristics. However, how their effector differentiation is developmentally regulated is still unclear. Here, we identify analogous effector subsets of these three innate T cell types in the thymus that share transcriptional profiles. Using single-cell RNA sequencing, we show that iNKT, MAIT and γδ T cells mature via shared, branched differentiation rather than linear maturation or TCR-mediated instruction. Simultaneous TCR clonotyping analysis reveals that thymic maturation of all three types is accompanied by clonal selection and expansion. Analyses of mice deficient of TBET, GATA3 or RORγt and additional in vivo experiments corroborate the predicted differentiation paths, while human innate T cells from liver samples display similar features. Collectively, our data indicate that innate T cells share effector differentiation processes in the thymus.


Assuntos
Diferenciação Celular , Imunidade Inata , Linfócitos T/metabolismo , Timo/imunologia , Animais , Células Cultivadas , Seleção Clonal Mediada por Antígeno , Humanos , Fígado/citologia , Fígado/imunologia , Ativação Linfocitária , Camundongos , Células T Invariáveis Associadas à Mucosa/metabolismo , Células T Matadoras Naturais/metabolismo , Análise de Sequência de RNA , Análise de Célula Única , Células Th17/metabolismo , Timo/citologia
20.
J Endod ; 46(9S): S56-S62, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32950196

RESUMO

INTRODUCTION: The maintenance of a stem cell pool is imperative to enable healing processes in the dental pulp tissue throughout life. As such, knowing mechanisms underlying stem cell self-renewal is critical to understand pulp pathophysiology and pulp regeneration. The purpose of this study was to evaluate the impact of stem cell factor (SCF) signaling through its receptor tyrosine kinase (c-Kit) on the self-renewal of human dental pulp stem cells (hDPSCs). METHODS: The hDPSCs were stably transduced with lentiviral vectors expressing shRNA-c-Kit or vector control. The impact of the SCF/c-Kit axis on hDPSC self-renewal was evaluated by using a pulpsphere assay in low attachment conditions and by evaluating the expression of polycomb complex protein Bmi-1 (master regulator of self-renewal) by Western blot and flow cytometry. RESULTS: The c-Kit-silenced hDPSCs formed fewer pulpspheres when compared with hDPSCs transduced with control vector (P < .05). Evaluation of pulpsphere morphology revealed the presence of 3 distinct sphere types, ie, holospheres, merospheres, and paraspheres. Although c-Kit silencing decreased the number of holospheres compared with control cells (P < .05), it had no effect on the number of merospheres and paraspheres. Recombinant human stem cell factor (rhSCF) increased the number of holospheres (P < .05) and induced dose-dependent Bmi-1 expression in hDPSCs. As expected, the inductive capacity of rhSCF on Bmi-1 expression and fraction of Bmi-1-positive cells was inhibited when we silenced c-Kit in hDPSCs. CONCLUSIONS: These results unveiled the role of SCF/c-Kit signaling on the self-renewal of hDPSCs and suggested that this pathway enables long-term maintenance of stem cell pools in human dental pulps.


Assuntos
Polpa Dentária , Células-Tronco , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Humanos , Transdução de Sinais
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