RESUMO
BACKGROUND: Tristetraprolin (TTP) is an RNA binding protein that plays a critical role in regulating proinflammatory immune responses by destabilizing target mRNAs via binding to their AU-rich elements (AREs) in the 3'-UTRs of mRNAs. A recent CLIP-seq study revealed that TTP-binding sites are enriched in the intronic regions of RNA. TTP is also a nuclear protein that exhibits putative DNA-binding activity. These features suggested that TTP might regulate gene transcription and/or alternative splicing of pre-mRNAs in the absence of stimulation. RESULTS: To elucidate the regulatory pattern of TTP, we cloned and overexpressed the human TTP-encoding gene, ZFP36, in HeLa cells in the absence of inflammatory stimuli. The transcriptomes of the control and ZFP36-overexpressing cells were sequenced and subjected to analysis and validation. Upon ZFP36 overexpression, the expression of genes associated with innate immunity, including those in the type I interferon signaling pathway and viral response, were specifically upregulated, implying a transcriptional regulatory mechanism associated with the predicted DNA binding activity of TTP. TTP preferentially regulated the alternative splicing of genes involved in the positive regulation of the I-κB/NF-κB cascade and the TRIF-dependent toll-like receptor, MAPK, TNF, and T cell receptor signaling pathways. CONCLUSIONS: Our findings indicated that TTP may regulate the immune response via the regulation of alternative splicing and potentially transcription, which greatly expands the current understanding of the mechanisms of TTP-mediated gene regulation.
Assuntos
Processamento Alternativo/genética , Imunidade Inata/genética , Tristetraprolina/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Células HeLa , Humanos , Interferon Tipo I/genética , Interferon Tipo I/metabolismo , NF-kappa B/genética , RNA Mensageiro/genética , Receptores de Antígenos de Linfócitos T/genética , Transdução de Sinais/genética , Tristetraprolina/genética , Fator de Necrose Tumoral alfa/genéticaRESUMO
To explore the desensitization treatment of patients waiting for kidney transplantation, this article comparative analysis of the effect of splenic irradiation on mean fluorescence intensity (MFI) values of HLA antibodies of 4 presensitized patients. After splenic irradiation, the mean MFI values of HLA-I antibody in 4 patients all decreased (P ≤ .001, P ≤ .001, P ≤ .001, P ≤ .001), and 3 patients had a decrease in intensity level (P ≤ .001, P = .001, P ≤ .001); as for HLA-II antibody, the mean MFI values in 3 patients also decreased (P ≤ .001, P = .025, P = .016), 1 patient had a decrease in intensity level (P ≤ .001) and the other 2 cases had no significant changes (P = 1.000, P = .564). On the other hand, splenic irradiation reduces MFI values in different levels of HLA antibody. So, splenic irradiation can reduce the MFI values of HLA antibodies.
Assuntos
Transplante de Rim , Humanos , Transplante de Rim/efeitos adversos , Antígenos HLA , Anticorpos , Rejeição de Enxerto/prevenção & controle , Teste de Histocompatibilidade , IsoanticorposRESUMO
Bi2MoO6/TiO2 heterostructures (HSs) were synthesized in the present study by growing Bi2MoO6 nanosheets on vertically aligned TiO2 nanorod arrays using a two-step solvothermal method. Their morphology and structure were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Excellent visible-light absorption was observed by UV-Vis absorption spectroscopy, which was attributed to the presence of the Bi2MoO6 nanosheets with a narrow-band-gap. The specific surface area and pore volume of the photocatalysts were significantly increased due to the hierarchical structure composed of Bi2MoO6 nanosheets and TiO2 nanorods. The photoluminescence and photoelectrochemical characterizations showed improved separation and collection efficiency of the Bi2MoO6/TiO2 HSs towards the interface charge carrier. The photocatalytic analysis of the Bi2MoO6/TiO2 HSs demonstrated a significantly better methylene blue (MB) degradation efficiency of 95% within 3 h than pristine TiO2 nanorod arrays under visible-light irradiation. After three photocatalytic cycles, the degradation rate remained at ~90%. The improved performance of the Bi2MoO6/TiO2 HSs was attributed to the synergy among the extended absorption of visible light; the large, specific surface area of the hierarchical structure; and the enhanced separation efficiency of the photogenerated electron-hole pairs. Finally, we also established the Bi2MoO6/TiO2 HSs band structure and described the photocatalytic dye degradation mechanism. The related electrochemical analysis and free-radical trapping experiments indicated that h+, ·O2- and ·OH have significant effects on the degradation process.
RESUMO
The oxidative stress response plays an important role in the occurrence and development of diabetic kidney disease (DKD). It has become a new treatment target for DKD. In the current study, the effects of carbamylated erythropoietin (CEPO) on renal oxidative stress and damage in diabetic rats were examined. Thirty Sprague Dawley rats were intraperitoneally administered with 60 mg/kg streptozotocin to establish the diabetes model. The diabetic rats were randomly allocated into 4 groups (n=6 each): diabetes model group (DM group), DM + CEPO treatment group (DC group), DM + CEPO + EPO receptor (EPOR) blocking peptide treatment group (DCEB group), and DM + CEPO + CD131 blocking peptide treatment group (DCCB group). Meanwhile, a normal control group (NC group, n=6) was set up. Kidney tissues and blood samples were obtained for evaluation of oxidative stress and renal function. The results showed that diabetic rats exhibited increased oxidative stress in the kidney and early pathological changes associated with DKD. Treatment with CEPO reduced oxidative stress and attenuated renal dysfunction. However, diabetic rats treated with the combination of CEPO and EPOR blocking peptide or CD131 blocking peptide showed increased oxidative stress and reduced renal function when compared with CEPO treatment alone group. These results suggested that CEPO can protect against kidney damage in DKD by inhibiting oxidative stress injury via EPOR-CD131 heterodimers.
Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Eritropoetina/análogos & derivados , Estresse Oxidativo/efeitos dos fármacos , Animais , Subunidade beta Comum dos Receptores de Citocinas/genética , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/patologia , Nefropatias Diabéticas/induzido quimicamente , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/patologia , Eritropoetina/genética , Eritropoetina/farmacologia , Humanos , Rim/efeitos dos fármacos , Rim/lesões , Rim/patologia , Ratos , Ratos Sprague-Dawley , Estreptozocina/toxicidadeRESUMO
Recent studies suggest that Poly(ADP-ribose) polymerase 1 (PARP1) acts as an RNA-binding protein in a majority of renal diseases with tubular cell injury. However, detailed knowledge of RNA targets and the RNA-binding regions for PARP1 is unknown. Herein, mapping of iRIP-seq reads in HK-2 renal tubular epithelial cells showed a biased distribution at coding sequence (CDS) and intron regions that is specific to these cells. A total of 1708 differentially expressed genes were identified after PARP1 knockdown using RNA-seq. Furthermore, transcriptome analysis also showed that selective variable splicing was globally regulated by PARP1 in HK-2 cells. By comparison of PARP1 RNA-seq and iRIP-seq data, we found 68 overlapping genes that are enriched in 'extracellular matrix' pathway. Follow-up identification of their interactions may contribute vital insights into the regulatory role of PARP1 as an RNA-binding protein in HK-2 cells.
Assuntos
Matriz Extracelular/genética , Rim/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Proteínas de Ligação a RNA/genética , Matriz Extracelular/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/genética , Humanos , Íntrons/genética , Túbulos Renais Proximais/metabolismo , RNA/genética , Splicing de RNA/genética , RNA-SeqRESUMO
Long noncoding RNAs (lncRNAs) are persistently expressed and have been described as potential biomarkers and therapeutic targets in various diseases. However, there is limited information regarding lncRNA expression in the tissue of kidney exhibiting lupus nephritis (LN)a serious complication of systemic lupus erythematosus (SLE). In this study, RNA sequencing (RNA-seq) was performed to characterize the lncRNA and mRNA expression in kidney tissues from LN (MRL/lpr) and control mice. We identified 12,979 novel lncRNAs in mouse. The expression profiles of both mRNAs and lncRNAs were differed significantly between LN and control mice. In particular, there were more upregulated lncRNAs and mRNAs than downregulated ones in the kidney tissues of LN mice. However, GO analysis showed that more downregulated genes were enriched in immune and inflammatory response-associated pathways. KEGG analysis showed that both downregulated and upregulated genes were enriched in a number of pathways, including the SLE pathway, and approximately half of these SLE-associated genes encoded inflammatory factors. Moreover, we observed that 2,181 DElncRNAs may have targeted and regulated the expression of 778 mRNAs in LN kidney tissues. The results of this study showed that 11 DElncRNAs targeted and were co-expressed with six immune and SLE-associated genes. qPCR analysis confirmed that lncRNA Gm20513 positively regulated the expression of the SLE-associated gene H2-Aa. In conclusion, the results of our study demonstrates that lncRNAs influence the progression of LN and provide some cues for further study of lncRNAs in LN. These results regarding the lncRNA-mRNAregulatory network may have important value in LN diagnosis and therapy.
RESUMO
Tristetraprolin (TTP) regulates inflammatory and immune responses by destabilizing target mRNAs via binding to their 3'-UTR AREs. We have recently reported that TTP preferentially up-regulates the expression level of innate immunity genes involved in the type I interferon-mediated signaling pathway and viral response in cancer cells. To elucidate the role of TTP-RNA interaction in TTP-mediated upregulation of gene expression, we performed iRIP-seq experiments to obtain the RNA interaction map consisting of direct and indirect binding sites of TTP in HeLa cells. We found substantial TTP binding signals in mRNA regions and the introns. ARE-motif AUUUA is over-represented in TTP binding peaks. Strikingly, AUUUA frequency is high both in 3'UTR and intronic regions, and the intronic peaks were more associated with TTP-regulated genes. Analysis of the over-represented motifs in TTP peaks revealed the high frequencies of UAGG and GUGUG motifs reported for hnRNPA2/B1 and CELF1 respectively in the 3'UTR and introns, and also the UGGAC motif overlapping with the m6A motif GGACU in the CDS regions. We further demonstrated that TTP binds to multiple intronic and exonic sites in the pre-mRNA/mRNA of the transcription factor RelB, correlating with the TTP-upregulated expression of RelB. TTP-up-regulated genes without a TTP binding site, but not those with, are highly enriched in innate immunity pathways and show higher tendency of harboring RelB binding sites in their promoter regions. These findings support a model in which TTP binding of RelB pre-mRNA/mRNA coordinates the RelB upregulation and activation of the innate immunity for antiviral response.
Assuntos
Redes Reguladoras de Genes/imunologia , Imunidade Inata/genética , RNA Mensageiro/metabolismo , Fator de Transcrição RelB/metabolismo , Tristetraprolina/metabolismo , Regiões 3' não Traduzidas/genética , Elementos Ricos em Adenilato e Uridilato/genética , Processamento Alternativo/imunologia , Sítios de Ligação , Perfilação da Expressão Gênica , Células HeLa , Humanos , Íntrons/genética , Regiões Promotoras Genéticas , Precursores de RNA/genética , Precursores de RNA/metabolismo , Estabilidade de RNA , RNA Mensageiro/genética , Regulação para CimaRESUMO
Two types of alternating morphology transitions have been observed in crystallization of NH4Cl on agar plates. One is the alternating morphology transitions between dense branching morphology and sparse branching morphology, and the other is the alternating morphology transitions between dense branching morphology and zigzag branching morphology. The appearance of them is found to depend on the mass proportion of agar to NH4Cl in the initial solution and the relative humidity. It is suggested that both the two alternating morphology transitions result from the oscillation of solute concentration in front of the growing interface caused by the competition of crystal growth and solute transfer at a moderate mass proportion. Which one of them occurs depends on the relative humidity, which controls the supersaturation.
RESUMO
A facile two-step synthesis route combining electrospinning and hydrothermal techniques has been performed to obtain Bi2Ti2O7/TiO2 heterostructured submicron fibers. Bi2Ti2O7 nanosheets were grown on the surface of TiO2 submicron fibers. The density of the nanosheets increased with higher precursor concentration of the Bi/Ti reaction raw materials. UV-visible (UV-vis) diffuse reflectance spectroscopy indicated that the absorption spectrum of the Bi2Ti2O7/TiO2 composite extended into the visible-light region. Photocatalytic tests showed that the Bi2Ti2O7/TiO2 heterostructures possess a much higher degradation rate of rhodamine B than the unmodified TiO2 submicron fibers under visible light. The enhanced photocatalytic activity can be attributed to the synergistic effect between improved visible-light absorption and the internal electric field created by the heterojunctions. The effective separation of photogenerated carriers driven by the photoinduced potential was demonstrated by the photoelectrochemical analysis.
RESUMO
To investigate the influence of fasudil on the epithelial-mesenchymal transdifferentiation of renal tubular epithelial cells from diabetic rats and explore the mechanisms of this effect. Wistar rats were randomly divided into the following three groups: control, diabetes and fasudil-treatment. All rats were sacrificed after three months of feeding with or without fasudil treatment. Pathological changes to the glomeruli and renal interstitium were studied using Periodic acid-Schiff's staining and Masson staining, respectively. Expression of ROCK1, alpha-SMA, E-cadherin and the distribution of beta-catenin in rat renal cortex were revealed by immunohistochemistry. Changes in the MYPT1 phosphorylation profile and alpha-SMA, E-cadherin and membrane beta-catenin expression were revealed by western blot. Changes in the levels of ROCK1, E-cadherin and total beta-catenin mRNA expression were analyzed by real-time PCR. Fasudil treatment notably attenuates renal interstitial fibrosis in diabetic rats. Compared to the control rats, diabetic rats showed elevated phosphorylation of MYPT1, increased expression of ROCK1 and alpha-SMA, decreased expression of E-cadherin and membrane beta-catenin, and increased expression of ROCK1 and total beta-catenin mRNA, decreased expression of E-cadherin mRNA. Fasudil treatment of diabetic rats resulted in attenuated MYPT1 phosphorylation, decreased ROCK1 and alpha-SMA expression, increased E-cadherin and membrane beta-catenin expression, and reduced ROCK1 and total beta-catenin mRNA expression, increased expression of E-cadherin mRNA. In conclusion, fasudil may reduce the epithelial-mesenchymal transdifferentiation and renal interstitial fibrosis in diabetic rats through a mechanism by which ROCK activity is inhibited, which further facilitates the recovery of the cell-cell adhesions among renal tubular epithelial cells and adhesion complex formation.
Assuntos
1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/análogos & derivados , Transdiferenciação Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Células Epiteliais/metabolismo , Rim/efeitos dos fármacos , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/uso terapêutico , Acetilglucosamina/urina , Actinas/metabolismo , Animais , Glicemia/efeitos dos fármacos , Caderinas/metabolismo , Creatinina/sangue , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Células Epiteliais/patologia , Fibrose/tratamento farmacológico , Rim/metabolismo , Rim/patologia , Túbulos Renais/efeitos dos fármacos , Masculino , Proteína Fosfatase 1/metabolismo , Distribuição Aleatória , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , beta Catenina/metabolismo , Quinases Associadas a rho/metabolismoRESUMO
Inflammatory reactology has become increasingly important in diabetic kidney disease. In this study, we estabilished STZ-induced diabetic rat model to investigate whether dendritic cells (DCs) mediated tubulointerstitial damages, and whether the effects by DCs were mediated by P-selectin expression and can be inhibited by atorvastatin. The study demonstrated that there was an accumulation of DCs in diabetic rats mediated by P-selectin. It also showed the accumulation of DCs and expression of P-selectin was closely correlated with the degree of renal tubulointerstitial injury. These effects were markedly attenuated by atorvastatin. Thus, DCs play a role in tubulointerstitial damages, atorvasttin can prevent renal tubulointerstitium from damage by inhibiting the P-selectin expression and DCs migration.