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1.
Environ Sci Technol ; 58(25): 11185-11192, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38869092

RESUMO

Electrocatalytic hydrogen atom-hydroxyl radical (H*-·OH) redox system is a promising approach for contaminant removal and mineralization. However, its working mechanism, especially the effect of H*, remains unclear, hindering its practical application. Herein, we constructed an electrochemical reactor equipped with our self-made Pd-loaded Ti/TiO2 nanotube cathode and a commercial boron-doped diamond anode. After fulfilling the electrode characterization and free radical detection, we employed coumarin and 7-azido-4-methylcoumarin as probes to confirm the participation of H* in the transformation of organic compounds. A comprehensive study on the degradation kinetics, reaction, and mineralization mechanisms using benzoic acid (BA) and 4-chlorophenol (4-CP) as model compounds was further conducted. The rate constants and total organic carbon removal of BA and 4-CP in the redox system increased compared with those of the individual oxidation and reduction processes. Theoretical calculations demonstrate that H* opens up alternative pathways for BA and 4-CP ring cleavage, forming quinones as reactive intermediates. Furthermore, H* facilitates the mineralization of the typical intermediates, maleic acid and fumaric acid, through C=C bond addition and H-abstraction from the 1,1-diol structure. The presence of H* provides alternative pathways for pollutant transformation, consequently reducing the treatment duration.


Assuntos
Hidrogênio , Oxirredução , Hidrogênio/química , Cinética
2.
Mol Cell Biochem ; 478(7): 1465-1473, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36370237

RESUMO

LRRC1 is a regulator of cellular polarity that is expressed at high levels in a range of tumor tissue types. Here, we conducted an analysis of the previously unexplored role of LRRC1 as a component of the adipogenic differentiation network. During the early stage (days 3-7) adipocytic differentiation of human mesenchymal stem cells (MSCs), LRRC1 was found to be upregulated at both the mRNA and protein levels. Moreover, the expression of LRRC1 was found to be controlled by PPARγ, which is a key transcriptional regulator of adipogenesis. Inhibiting LRRC1 expression reduced the adipogenic potential of hMSCs, with a concomitant reduction in the expression of three adipogenesis-associated proteins (SCD, LIPE, FASN). Together, these data offer new insight into the functional importance of LRRC1 both in general and in the context of adipocytic differentiation.


Assuntos
Células-Tronco Mesenquimais , Neoplasias , Humanos , PPAR gama/genética , PPAR gama/metabolismo , Células-Tronco Mesenquimais/metabolismo , Diferenciação Celular , Adipogenia/genética , Neoplasias/metabolismo , Células Cultivadas , Proteínas de Transporte/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo
3.
Pharm Dev Technol ; 28(8): 743-754, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37577952

RESUMO

Exploitation of advanced methotrexate (MTX) delivery with nanocomposites has important clinical application value. Poloxamer 188 micelle and layered double hydroxide loaded with MTX (LDH-MTX) by exfoliation reassembling were used to prepare LDH-MTX-poloxamer 188 nanocomposites with good dispersibility and efficient cellular uptake for controlled drug delivery. The LDH-MTX-poloxamer 188 nanocomposites with sphere-like morphology, of which the average hydrodynamic diameter was <100 nm, were shown to have better dispersion state than naked LDH-MTX. Importantly, the LDH-MTX-poloxamer 188 nanocomposites could achieve significant sustained drug release and have obvious pH dependent responsive release ability. In addition, these nanocomposites also exhibited long-term and excellent in vitro antitumor efficacy as opposed to pure MTX or LDH-MTX as evident from cell viability. More interestingly, compared to pure FITC used to simulate MTX, LDH nanocomposites labeled with FITC were considered to have better cell adhesion through cell uptake. Therefore, the studied nanocomposites of LDH-MTX-poloxamer 188 can be further used as a new advanced MTX delivery nanovehicles with desired properties in future therapeutic aspects.


Assuntos
Metotrexato , Nanocompostos , Metotrexato/farmacologia , Metotrexato/química , Poloxâmero , Fluoresceína-5-Isotiocianato , Hidróxidos/química , Nanocompostos/química
4.
J Mol Cell Cardiol ; 164: 1-12, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34774548

RESUMO

BACKGROUND: Heart transplantation, a life-saving approach for patients with end-stage heart disease, is limited by shortage of donor organs. While prolonged storage provides more organs, it increases the extent of ischemia. Therefore, we seek to understand molecular mechanisms underlying pathophysiological changes of donor hearts during prolonged storage. Additionally, considering mesenchymal stromal cell (MSC)-derived paracrine protection, we aim to test if MSC secretome preserves myocardial transcriptome profile and whether MSC secretome from a certain source provides the optimal protection in donor hearts during cold storage. METHODS AND RESULTS: Isolated mouse hearts were divided into: no cold storage (control), 6 h cold storage (6 h-I), 6 h-I + conditioned media from bone marrow MSCs (BM-MSC CM), and 6 h-I + adipose-MSC CM (Ad-MSC CM). Deep RNA sequencing analysis revealed that compared to control, 6 h-I led to 266 differentially expressed genes, many of which were implicated in modulating mitochondrial performance, oxidative stress response, myocardial function, and apoptosis. BM-MSC CM and Ad-MSC CM restored these gene expression towards control. They also improved 6 h-I-induced myocardial functional depression, reduced inflammatory cytokine production, decreased apoptosis, and reduced myocardial H2O2. However, neither MSC-exosomes nor exosome-depleted CM recapitulated MSC CM-ameliorated apoptosis and CM-improved mitochondrial preservation during cold ischemia. Knockdown of Per2 by specific siRNA abolished MSC CM-mediated these protective effects in cardiomyocytes following 6 h cold storage. CONCLUSIONS: Our results demonstrated that using MSC secretome (BM-MSCs and Ad-MSCs) during prolonged cold storage confers preservation of the normal transcriptional "fingerprint", and reduces donor heart damage. MSC-released soluble factors and exosomes may synergistically act for donor heart protection.


Assuntos
Transplante de Coração , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Animais , Medula Óssea , Humanos , Peróxido de Hidrogênio/metabolismo , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Secretoma , Doadores de Tecidos , Transcriptoma
5.
Pediatr Surg Int ; 38(12): 1971-1979, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36208323

RESUMO

PURPOSE: Preterm infants are more susceptible to necrotizing enterocolitis (NEC) than term Queryinfants. This may be due to a relative paucity of Lgr5+ or Bmi1+-expressing intestinal stem cells (ISCs) which are responsible for promoting intestinal recovery after injury. We hypothesized that the cellular markers of Lgr5+ and Bmi1+, which represent the two distinct ISC populations, would be lower in younger mice compared to older mice. In addition, we hypothesized that experimental NEC would result in a greater loss of Lgr5+ expression compared to Bmi1+ expression. METHODS: Transgenic mice with EGFP-labeled Lgr5 underwent euthanasia at 10 different time points from E15 to P56 (n = 8-11/group). Lgr5+-expressing ISCs were quantified by GFP ELISA and Bmi1+ was assessed by qPCR. In addition, Lgr5EGFP mice underwent experimental NEC via formula feeding and hypoxic and hypothermic stress. Additional portions of the intestine underwent immunostaining with anti-GFP or anti-Bmi1+ antibodies to confirm ELISA and PCR results. For statistical analysis, p < 0.05 was significant. RESULTS: Lgr5+ and Bmi1+expression was lowest in embryonal and early postnatal mice and increased with age in all segments of the intestine. Experimental NEC was associated with loss of Lgr5+-expressing ISCs but no significant change in Bmi1+ expression. CONCLUSION: Lgr5+ and Bmi1+ expression increase with age. Lgr5+-expressing ISCs are lower following experimental necrotizing enterocolitis while Bmi1+ expression remains relatively unchanged. Developing a targeted medical therapy to protect the low population of ISCs in preterm infants may promote tissue recovery and regeneration after injury from NEC.


Assuntos
Enterocolite Necrosante , Doenças do Recém-Nascido , Recém-Nascido , Humanos , Camundongos , Animais , Enterocolite Necrosante/genética , Enterocolite Necrosante/metabolismo , Mucosa Intestinal/metabolismo , Recém-Nascido Prematuro , Células-Tronco/metabolismo , Intestinos , Camundongos Transgênicos
6.
Angew Chem Int Ed Engl ; 61(45): e202210753, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-35997542

RESUMO

Directly splitting seawater to produce hydrogen provides a promising pathway for energy and environmental sustainability. However, current seawater splitting faces many challenges because of the sluggish kinetics, the presence of impurities, membrane contamination, and the competitive chloride oxidation reaction at the anode, which makes it more difficult than freshwater splitting. This Review firstly introduces the basic mechanisms of the anode and cathode reactions during seawater splitting. We critically analyze the primary principles for designing catalysts for seawater splitting in terms of both the hydrogen and oxygen evolution reactions, including with noble metal, noble metal free, and metal-free catalysts. Strategies to design effective catalysts, such as active site population, synergistic effect regulation, and surface engineering, are discussed. Furthermore, promises, perspectives, and challenges in developing seawater splitting technologies for clean hydrogen generation are summarized.

7.
Curr Opin Hematol ; 28(4): 243-250, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33966008

RESUMO

PURPOSE OF REVIEW: Development and functions of hematopoietic stem cells (HSC) are regulated by multiple cellular components of the hematopoietic niche. Here we review the recent advances in studying the role of three such components -- osteoblasts, osteomacs, and megakaryocytes and how they interact with each other in the hematopoietic niche to regulate HSC. RECENT FINDINGS: Recent advances in transgenic mice models, scRNA-seq, transcriptome profile, proteomics, and live animal imaging have revealed the location of HSC within the bone and signaling molecules required for the maintenance of the niche. Interaction between megakaryocytes, osteoblasts and osteomacs enhances hematopoietic stem and progenitor cells (HSPC) function. Studies also revealed the niche as a dynamic entity that undergoes cellular and molecular changes in response to stress. Aging, which results in reduced HSC function, is associated with a decrease in endosteal niches and osteomacs as well as reduced HSC--megakaryocyte interactions. SUMMARY: Novel approaches to study the cellular components of the niche and their interactions to regulate HSC development and functions provided key insights about molecules involved in the maintenance of the hematopoietic system. Furthermore, these studies began to build a more comprehensive model of cellular interactions and dynamics in the hematopoietic niche.


Assuntos
Hematopoese , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Nicho de Células-Tronco , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Comunicação Celular , Diferenciação Celular , Humanos , Osteoblastos/citologia , Osteoblastos/metabolismo
8.
Artif Organs ; 45(10): 1141-1154, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34318520

RESUMO

A visual prosthesis is an auxiliary device for patients with blinding diseases that cannot be treated with conventional surgery or drugs. It converts captured images into corresponding electrical stimulation patterns, according to which phosphenes are generated through the action of internal electrodes on the visual pathway to form visual perception. However, due to some restrictions such as the few implantable electrodes that the biological tissue can accommodate, the induced perception is far from ideal. Therefore, an important issue in visual prosthesis research is how to detect and present useful information in low-resolution prosthetic vision to improve the visual function of the wearer. In recent years, with the development and broad application of computer vision methods, researchers have investigated the possibility of their utilization in visual prostheses by simulating prosthetic visual percepts. Through the optimization of visual perception by image processing, the efficiency of visual prosthesis devices can be further improved to better meet the needs of prosthesis wearers. In this article, recent works on prosthetic vision centering on implementing computer vision methods are reviewed. Differences, strengths, and weaknesses of the mentioned methods are discussed. The development directions of optimizing prosthetic vision and improving methods of visual perception are analyzed.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Percepção Visual , Próteses Visuais , Humanos , Aprendizado de Máquina , Pessoas com Deficiência Visual/reabilitação
9.
J Cell Physiol ; 235(1): 349-363, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31237701

RESUMO

Metabolism homeostasis plays an important role in progenitor-cell differentiation to adipocytes, but less is known about the whole transcriptional profiling of cellular metabolism during adipogenesis. We got the first insight into the whole transcriptional profiling of cellular metabolism during adipogenesis from human mesenchymal stem cells (hMSCs) by the RNA-Seq technique. There were 1,998, 2,629, 3,112, and 3,054 differentially expressed genes (DEGs) at Days 7, 14, 21, and 28, respectively, during adipogenesis. The most enriched phosphatidylinositol 3' kinase-serine/threonine kinase (PI3K-Akt) signaling pathway stimulated and directly regulated cellular metabolism by priming glucose aerobic glycolysis, arginine and proline metabolism, glutathione metabolism, and arachidonic acid metabolism during adipogenesis, targeting the potential key genes, such as fatty acid synthase (FABP4), phosphoenolpyruvate carboxykinase 1 (PKC1), stearoyl-CoA desaturase (SCD), and solute carrier family 2 member 1 of Gluts (SLC2A1). And it confirmed PCK1 as the key player for cellular metabolism by small interfering RNA. A comprehensive understanding of cellular metabolism and its regulatory axis of the signaling pathway during adipogenesis would reveal new study and therapy targets for fat metabolism disorders.


Assuntos
Adipócitos/citologia , Adipogenia/genética , Processamento Alternativo/genética , Regulação da Expressão Gênica/genética , Células-Tronco Mesenquimais/citologia , Ácido Araquidônico/metabolismo , Arginina/metabolismo , Células Cultivadas , Proteínas de Ligação a Ácido Graxo/metabolismo , Perfilação da Expressão Gênica , Transportador de Glucose Tipo 1/metabolismo , Glutationa/metabolismo , Glicólise/fisiologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Prolina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , Estearoil-CoA Dessaturase/metabolismo , Adulto Jovem
10.
J Cell Physiol ; 235(1): 328-338, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31210354

RESUMO

MicroRNAs (miRNAs), the potential regulator of adipogenesis, markedly characterized by lipid droplet (LD) formation, play an important role in progenitor-cell differentiation into adipocytes. In recent years, it has excited interests in regulation of miRNAs in adipogenesis. However, no study is available, to our knowledge, regarding the expression of miRNAs on LD formation. Our study provides the first insight into the expression profiling of the miRNA targeting messenger RNAs (mRNAs) involving with LD formation during adipogenesis from human mesenchymal stem cells by RNA-Seq transcriptome technique. It showed that 39, 105, 194, and 112 differentially expressed miRNA appeared at 7, 14, 21, and 28 days, respectively, for LD formation during adipogenesis. Nineteen miRNAs targeted 35 mRNA associated with LDs formation. Except for the known miRNA hsa-miR-1908 regulating adipogenesis, five miRNAs, including hsa-miR-146a-3p, hsa-miR-4495, hsa-miR-4663, hsa-miR-6069, and hsa-miR-675-3p are the latest potential biomarkers for LD formation, targeting ACSL1, APOB, METTL7A, PLIN1, and PLIN4. A comprehensive transcriptome profiling of miRNA reveals the regulatory relationship between miRNA and mRNA relating to LD formation during adipogenesis. Such candidates may represent biomarkers and therapeutic targets for metabolic syndromes like obesity, type-2 diabetes, steatosis, atherosclerosis, and osteoporosis.


Assuntos
Adipócitos/citologia , Adipogenia/genética , Gotículas Lipídicas/metabolismo , Células-Tronco Mesenquimais/citologia , MicroRNAs/genética , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento/genética , Marcadores Genéticos/genética , Humanos , RNA Mensageiro/genética
11.
Eur J Immunol ; 49(2): 255-265, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30467836

RESUMO

Invariant natural killer T (iNKT) cells play critical roles in autoimmune, anti-tumor, and anti-microbial immune responses, and are activated by glycolipids presented by the MHC class I-like molecule, CD1d. How the activation of signaling pathways impacts antigen (Ag)-dependent iNKT cell activation is not well-known. In the current study, we found that the MAPK JNK2 not only negatively regulates CD1d-mediated Ag presentation in APCs, but also contributes to CD1d-independent iNKT cell activation. A deficiency in the JNK2 (but not JNK1) isoform enhanced Ag presentation by CD1d. Using a vaccinia virus (VV) infection model known to cause a loss in iNKT cells in a CD1d-independent, but IL-12-dependent manner, we found the virus-induced loss of iNKT cells in JNK2 KO mice was substantially lower than that observed in JNK1 KO or wild-type (WT) mice. Importantly, compared to WT mice, JNK2 KO mouse iNKT cells were found to express less surface IL-12 receptors. As with a VV infection, an IL-12 injection also resulted in a smaller decrease in JNK2 KO iNKT cells as compared to WT mice. Overall, our work strongly suggests JNK2 is a negative regulator of CD1d-mediated Ag presentation and contributes to IL-12-induced iNKT cell activation and loss during viral infections.


Assuntos
Antígenos CD1d/imunologia , Ativação Linfocitária , Proteína Quinase 9 Ativada por Mitógeno/imunologia , Células T Matadoras Naturais/imunologia , Animais , Antígenos CD1d/genética , Feminino , Interleucina-12/genética , Interleucina-12/imunologia , Masculino , Camundongos , Camundongos Knockout , Proteína Quinase 9 Ativada por Mitógeno/genética , Receptores de Interleucina-12/genética , Receptores de Interleucina-12/imunologia , Viroses/genética , Viroses/imunologia
12.
Biochem Biophys Res Commun ; 524(1): 163-168, 2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-31982135

RESUMO

Stanniocalcin-2 (STC2) is a glycoprotein that has been found to play key roles in the regulation of cancer, diabetes mellitus, and osteogenesis. Herein we sought to extend these past studies by examining the importance of STC2 in the context of human mesenchymal stem cell (hMSC) adipogenic differentiation and exploring the mechanisms underlying such importance. We found that STC2 expression was significantly reduced on day 7 of hMSC adipogenesis. When we deliberately overexpressed STC2 in these cells, this resulted in significantly decreased expression of both peroxisome proliferator-activated receptor γ (PPARγ) and Fatty Acid Binding Protein-4 (FABP4) together with increased extracellular-signal regulated kinase 1/2 (ERK1/2) phosphorylation and markedly reduced lipid droplet formation within cells. Treatment of cells using the ERK inhibitor U0126 disrupted this ERK1/2 phosphorylation and restored the adipogenic differentiation of these hMSCs. When we instead knocked down STC2 expression, the opposite phenotypes were observed. Together these findings thus reveal that STC2 modulates ERK1/2 signaling in hMSCs so as to suppress their adipogenic differentiation.


Assuntos
Adipogenia , Glicoproteínas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Sistema de Sinalização das MAP Quinases , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/enzimologia , Butadienos/farmacologia , Técnicas de Silenciamento de Genes , Humanos , Lentivirus/metabolismo , Nitrilas/farmacologia , Fosforilação
13.
J Reprod Dev ; 66(3): 231-239, 2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32051352

RESUMO

MicroRNAs (miRNAs) regulate the functions of granulosa cells by interacting with their target mRNAs. Insulin receptor substrate 2 (IRS2) is one of the targets of miR-431 and can be regulated by ovarian hormones. However, the role of miR-431 and the associated signal transduction pathway in ovarian development has not been studied previously. In this study, we first analyzed the expression of miR-431 and IRS2 following stimulation with pregnant mare serum gonadotropin (PMSG) during the estrous cycle or different stages of ovarian development in mice. Subsequently, we investigated the role, function, and signaling pathway of miR-431 in the human granulosa cell line, COV434. The results showed that follicle stimulating hormone (FSH) gradually decreased miR-431 levels, induced IRS2, and promoted pAKT expression. Moreover, miR-431 overexpression and IRS2 knockdown attenuated AKT activation, inhibited cell proliferation, and decreased estradiol (E2) and progesterone (P4) synthesis. Further, luciferase reporter assay demonstrated that IRS2 was a direct target of miR-431. In conclusion, this study demonstrated that miR-431 regulates granulosa cell function through the IRS2/PI3K/AKT signaling pathway.


Assuntos
Células da Granulosa/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , MicroRNAs/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , Animais , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Estradiol/metabolismo , Ciclo Estral/metabolismo , Feminino , Gonadotropinas Equinas/farmacologia , Células da Granulosa/efeitos dos fármacos , Proteínas Substratos do Receptor de Insulina/genética , Camundongos , MicroRNAs/genética , Ovário/efeitos dos fármacos , Ovário/metabolismo , Fosfatidilinositol 3-Quinases/genética , Progesterona/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/efeitos dos fármacos
14.
J Cell Physiol ; 234(11): 20217-20227, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30989650

RESUMO

Adipogenesis, a physiological process initiated with the committed preadipocytes expressing adipocyte-specific genes and terminated in mature, differentiated and functional adipocytes, mainly involved with energy homeostasis. Abnormal distribution-changes and dysfunctions in adipogenesis may lead to complex physiopathological disorders. However, it remains unclear for the key players working for the whole complex differentiating process of adipogenesis. Here, it investigated transcriptional profiling of adipogenesis from human mesenchymal stem cells (hMSCs) by RNA-Seq transcriptome technique. Oil Red O staining assays were performed to assess adipogenic potential. Quantitative real-time PCR (qRT-PCR) and lentivirus transfection assays by small interference RNA (siRNA) were conducted to confirm the function of the candidate genes. A total of 1,078 differentially expressed genes shared at 7, 14, 21, and 28 days during adipogenesis from hMSCs, and 706 genes were significantly differentially expressed. It identified 20 potential key genes responsible for adipogenesis with four genes downregulating. The candidate gene, coagulation factor II thrombin receptor (F2R), encoding coagulation factor II thrombin receptor involving with a 7-transmembrane receptor involved in the regulation of thrombotic response, also known as proteinase-activated receptor-1, contributed to adipogenesis, especially at Day 14, by Oil Red O staining, qRT-PCR, and western blot after siRNA. A unique discovery shed new light to understand the key players of the whole processes of adipogenesis from hMSCs. The gene F2R might be used as an adipogenic marker to provide a potential target for understanding the metabolic syndromes like obesity, type-2 diabetes, steatosis, atherosclerosis, and osteoporosis.


Assuntos
Adipócitos/fisiologia , Adipogenia/genética , Células-Tronco Mesenquimais/fisiologia , Diferenciação Celular/genética , Células Cultivadas , Regulação para Baixo/genética , Humanos , Síndrome Metabólica/genética , RNA Interferente Pequeno/genética , RNA-Seq/métodos , Transcrição Gênica/genética , Transcriptoma/genética
15.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 44(2): 122-127, 2019 Feb 28.
Artigo em Chinês | MEDLINE | ID: mdl-30837379

RESUMO

OBJECTIVE: To clone human mitogen-activated protein kinase kinase 6 (MKK6) gene promoter and explore its transcription activity by ubiquitin specific peptidase 22 (USP22).
 Methods: MKK6 gene promoter was amplified by PCR and two bases mutation within USP22 binding site was subsequently introduced. The wild type and mutant MKK6 promoter were inserted into the luciferase report vector pGL3-Basic, respectively. Recombinant plasmids were co-transfected with plasmid pRL-TK into HeLa cells, and the luciferase activities were measured by dual luciferase reporter system. Furthermore, the direct interaction between USP22 and MKK6 promoter was detected by chromatin immunoprecipitation (ChIP) assay. Finally, the MKK6 transcription activity was measured after knockdown of USP22.
 Results: The recombinant luciferase report vectors containing wild or mutant type of MKK6 promoter were successfully constructed. Mutation of USP22 binding site resulted in decrease of MKK6 promoter-driven luciferase activity in HeLa cells (P<0.05). USP22 could interact directly with MKK6 promoter. Down-regulation of USP22 led to the decreased MKK6 mRNA expression (P<0.05).
 Conclusion: USP22 could regulate the transcription activity of MKK6 gene in HeLa cells.


Assuntos
Tioléster Hidrolases/metabolismo , Células HeLa , Humanos , Luciferases , MAP Quinase Quinase 6 , Regiões Promotoras Genéticas , Transcrição Gênica , Ubiquitina Tiolesterase
16.
Mol Cell Biochem ; 449(1-2): 295-303, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29959592

RESUMO

MicroRNAs are members of the family of non-coding small RNAs that regulate gene expression either by inhibiting mRNA translation or by promoting mRNA degradation at the post-transcriptional level. They play an important role in the differentiation of human bone marrow mesenchymal stem cells (hMSCs) into adipocytes. However, the role of microRNAs in this process remains to be poorly understood. Here, we observed that miR-377-3p expression was markedly decreased during adipogenic differentiation of hMSCs. Overexpression of miR-377-3p decreased adipocyte differentiation and downregulated the expression of adipogenic markers. Meanwhile, bioinformatics-based studies suggested that LIFR is a target of miR-377-3p. Further analysis confirmed that expression of LIFR present markedly increased during adipogenic differentiation of hMSCs. In addition, downregulation expression of LIFR significantly inhibited the process of adipocyte differentiation. To confirm the relation between miR-377-3p and LIFR, luciferase reporter assays were carried out. The results indicated that miR-377-3p bound directly to the 3'-untranslated region of LIFR. These data indicate that miR-377-3p suppressed adipogenesis of hMSCs by targeting LIFR, which provides novel insights into the molecular mechanism of miRNA-mediated cellular differentiation.


Assuntos
Adipogenia , Células da Medula Óssea/metabolismo , Diferenciação Celular , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/biossíntese , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/metabolismo , Regiões 3' não Traduzidas , Células da Medula Óssea/citologia , Linhagem Celular , Humanos , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/genética , Células-Tronco Mesenquimais/citologia , MicroRNAs/genética
17.
Genet Mol Biol ; 41(2): 488-495, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30088609

RESUMO

The ubiquitin-specific protease 22 (USP22) is an oncogene and its expression is upregulated in many types of cancer. In the nucleus, USP22 functions as one subunit of the SAGA to regulate gene transcription. However, the genome-wide USP22 binding sites and its direct target genes are yet clear. In this study, we characterized the potential genomic binding sites of UPS22 and GCN5 by ChIP-seq using specific antibodies in HeLa cells. There were 408 overlapping putative target genes bound by both USP22 and GCN5. Motif analysis showed that the sequences bound by USP22 and GCN5 shared two common motifs. Gene ontology (GO) and pathway analysis indicated that the genes targeted by USP22 and GCN5 were involved in different physiological processes and pathways. Further RNA-seq, GO and pathway analyses revealed that knockdown of UPS22 induced differential expression of many genes that participated in diverse physiological processes, such as metabolic process. Integration of ChIP-seq and RNA-seq data revealed that UPS22 bound to the promoters of 56 genes. These findings may provide new insights into the regulation of USP22 on gene expression during the development of cervical cancer.

18.
Immunology ; 152(2): 232-242, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28518215

RESUMO

Mucosal-associated invariant T (MAIT) cells are conserved T cells that express a semi-invariant T-cell receptor (Vα7.2 in humans and Vα19 in mice). The development of MAIT cells requires the antigen-presenting MHC-related protein 1 (MR1), as well as commensal bacteria. The mechanisms that regulate the functional expression of MR1 molecules and their loading with bacterial antigen in antigen-presenting cells are largely unknown. We have found that treating B cells with the Toll-like receptor 9 (TLR9) agonist CpG increases MR1 surface expression. Interestingly, activation of TLR9 by CpG-A (but not CpG-B) enhances MR1 surface expression. This is limited to B cells and not other types of cells such as monocytes, T or natural killer cells. Knocking-down TLR9 expression by short hairpin RNA reduces MR1 surface expression and MR1-mediated bacterial antigen presentation. CpG-A triggers early endosomal TLR9 activation, whereas CpG-B is responsible for late endosomal/lysosomal activation of TLR9. Consistently, blocking endoplasmic reticulum to Golgi protein transport, rather than lysosomal acidification, suppressed MR1 antigen presentation. Overall, our results indicate that early endosomal TLR9 activation is important for MR1-mediated bacterial antigen presentation.


Assuntos
Apresentação de Antígeno , Antígenos de Bactérias/imunologia , Linfócitos B/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Ativação Linfocitária , Antígenos de Histocompatibilidade Menor/imunologia , Receptor Toll-Like 9/imunologia , Antígenos de Bactérias/metabolismo , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Linfócitos B/microbiologia , Linhagem Celular Tumoral , Ilhas de CpG , Retículo Endoplasmático/imunologia , Retículo Endoplasmático/metabolismo , Endossomos/imunologia , Endossomos/metabolismo , Complexo de Golgi/imunologia , Complexo de Golgi/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Lisossomos/imunologia , Lisossomos/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Oligonucleotídeos/farmacologia , Transporte Proteico , Interferência de RNA , Transdução de Sinais , Fatores de Tempo , Receptor Toll-Like 9/efeitos dos fármacos , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/metabolismo , Transfecção
19.
Chemistry ; 23(70): 17823-17828, 2017 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-29068104

RESUMO

As Liu et al. reported previously (Appl. Mater. Today 2017, 7, 239-245), the charge transfer to partially oxidized polyaniline (PANI) nanotubes in electrochemical reactions is heavily limited due to the non-conductivity of the reduction/oxidation products. In this paper, the doping level of individual PANI nanotubes was substantially enhanced using nitrite as an electron acceptor in sulfuric acid aqueous solution as recorded by the nano-impact method. The charge transferred to one single tube during reduction process is close to the theoretical value of 170±112 pC per tube (assuming 2-electron reduction for the PANI tubes studied), while the charge during PANI oxidation is dramatically decreased. Reaction processes are proposed based on the oxidative properties of nitrite in acid solution. UV-visible spectroscopy analysis further confirms an oxidation-reduction reaction between PANI and nitrite. In contrast the electrochemical reaction of ensembles (21 µg cm-1 ) of PANI tubes on glassy carbon electrodes simply show limited electrocatalytic activity.

20.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 48(6): 824-827, 2017 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-29260514

RESUMO

OBJECTIVE: To construct the expression vectors for red fluorescent protein fused with inhibiting peptides for nuclear import (Bimax),and explore the location of Bimax and its potential effects on cell proliferation and migration in HeLa cells. METHODS: Two kinds of polynucleotide encoding inhibiting peptides for nuclear import were synthesis respectively and subsequently annealed for inserting into vector pDs-Red-C1. The recombinant plasmids were transfected into competent bacterial DH-5α. After transfection,the positive bacteria were picked up for DNA sequencing. The recombinant plasmids pDs-Red-Bimax2,pDs-Red-Bimax1 and negative plasmid pDs-Red-C1 were transfected into HeLa cells respectively according to Lipofectamine2000 protocol. After transfection,the expression and location of red fluorescent protein were observed with fluorescence microscope. Furthermore,MTT assay and cell-migration assay were used to detect the proliferation and migration of Bimax transducted cells. RESULTS: DNA sequencing showed that the polynucleotides encoding Bimax1 or Bimax2 were inserted into pDs-Red-C1 vector successfully. After transfected into HeLa cells,the inhibiting peptide induced red fluorescent protein locating in nuclear. Furthermore,either the fusion protein RFP-Bimax1 or RFP-Bimax2 can suppress the proliferation and migration of HeLa cells. CONCLUSION: The expression vectors for red fluorescent protein fused with inhibiting peptides for nuclear import were successfully constructed. In addition,the fusion proteins were expressed and located in nuclear and suppressed the proliferation and migration of tumor cells.


Assuntos
Transporte Ativo do Núcleo Celular , Vetores Genéticos , Peptídeos , Plasmídeos , Movimento Celular , Células HeLa , Humanos , Proteínas Luminescentes , Transfecção , Proteína Vermelha Fluorescente
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