Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Clin Appl Thromb Hemost ; 27: 10760296211050640, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34719982

RESUMO

OBJECTIVE: To investigate the safety and efficacy of regional citrate anticoagulation (RCA) on elderly patients at high risk of bleeding after continuous renal replacement therapy (CRRT). METHODS: A total of 31 patients at high risk of bleeding who received CRRT in the intensive care unit were collected. The patients were divided into RCA group (n = 17) and no anticoagulation group (NA, n = 14) according to whether RCA was used or not. The levels of creatinine (Cr), blood urea nitrogen (BUN), prothrombin time (PT), activated partial thromboplastin time (APTT), total calcium (tCa), ionized calcium ion (iCa2+), sodium ion (Na+), bicarbonate ion (HCO3-), tCa/iCa2+ ratio, and pH were observed after treatment. The filter use time, number of filters used, filter obstruction events, clinical outcomes, and safety evaluation indexes were compared post-treatment. RESULTS: After treatment, serum Cr and BUN levels, APTT and PT levels in the RCA group were significantly lower than the NA group. The tCa, iCa2+, HCO3-, tCa/iCa2+, and pH were within the normal range after RCA treatment while Na+ levels saw a significant increase. In the RCA group, the filter using time was significantly longer, with significantly reduced numbers of filter use within 72 h and filter disorder events. Additionally, patients in the RCA group showed significant recovery of renal function and a significant reduction in bleeding events and in-hospital mortality. CONCLUSION: RCA treatment significantly improves clinical outcome of patients at high risk of bleeding after CRRT, safely and effectively prolongs the filter life and avoids coagulation incidences.

2.
Bioconjug Chem ; 32(8): 1915-1925, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34247477

RESUMO

A three-dimensional (3D) printed biodegradable hydrogel scaffold with a strong self-expanding ability to conform to the contour of irregular bone defects and be closely adjacent to host tissues is reported herein. The scaffold has a triple cross-linked network structure consisting of photo-cross-linked polyacrylamide (PAAM) and polyurethane (PU) as the primary IPN network and chemical cross-linked gelatin (Gel) as the secondary network, which confers the scaffold with good mechanical properties. The addition of PU in the polymerization process of acrylamide (AAM) can improve the ultraviolet (UV) photocuring efficiency of the hydrogel and incorporate abundant hydrogen bonds between the PAAM copolymer chain and the PU chain. The results show that the hydrogel scaffold contains regular structures with smooth morphology, excellent dimensional stability, and uniform aperture. The degradation rate of the hydrogel scaffold is controllable through adjusting cross-linking agents and can be up to about 60% after degradation for 28 days. More importantly, the rapid self-inflating characteristic of the scaffold in water, that is, the volume of hydrogel scaffold can increase to about 8 times that of their own in an hour and can generate a slight compressive stress on the surrounding host tissue, thus stimulating the reconstruction and growth of new bone tissues. The in vitro experiment indicates that the scaffold is nontoxic and biocompatible. The in vivo experiment shows that the PU/PAAM/Gel chemically cross-linked scaffold displays the desirable osteogenic capability. This UV-curable 3D printed self-adaptive and degradable hydrogel scaffold holds great potential for nonload-bearing bone repair.

3.
Hepatology ; 74(4): 2133-2153, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34133792

RESUMO

BACKGROUND AND AIMS: Hepatic ischemia/reperfusion (I/R) injury, a common clinical problem that occurs during liver surgical procedures, causes a large proportion of early graft failure and organ rejection cases. The identification of key regulators of hepatic I/R injury may provide potential strategies to clinically improve the prognosis of liver surgery. Here, we aimed to identify the role of tumor necrosis factor alpha-induced protein 3-interacting protein 3 (TNIP3) in hepatic I/R injury and further reveal its immanent mechanisms. APPROACH AND RESULTS: In the present study, we found that hepatocyte TNIP3 was markedly up-regulated in livers of both persons and mice subjected to I/R surgery. Hepatocyte-specific Tnip3 overexpression effectively attenuated I/R-induced liver necrosis and inflammation, but improved cell proliferation in mice, whereas TNIP3 ablation largely aggravated liver injury. This inhibitory effect of TNIP3 on hepatic I/R injury was found to be dependent on significant activation of the Hippo-YAP signaling pathway. Mechanistically, TNIP3 was found to directly interact with large tumor suppressor 2 (LATS2) and promote neuronal precursor cell-expressed developmentally down-regulated 4-mediated LATS2 ubiquitination, leading to decreased Yes-associated protein (YAP) phosphorylation at serine 112 and the activated transcription of factors downstream of YAP. Notably, adeno-associated virus delivered TNIP3 expression in the liver substantially blocked I/R injury in mice. CONCLUSIONS: TNIP3 is a regulator of hepatic I/R injury that alleviates cell death and inflammation by assisting ubiquitination and degradation of LATS2 and the resultant YAP activation.TNIP3 represents a promising therapeutic target for hepatic I/R injury to improve the prognosis of liver surgery.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33669034

RESUMO

Developing urban low-carbon traffic is an effective measure to reduce traffic carbon emissions, which are important parts of greenhouse gas. In order to understand the development characteristics and regular patterns of urban low-carbon traffic, we present a game model that enables us to predict the possible range of travel mode choice and the impact of low-carbon awareness. Through chaos analysis and simulation of the model, the authors come to realize that the proportions of travel mode choice can reach an equilibrium under a certain urban traffic system. This equilibrium is related to low-carbon awareness and the situation of the urban traffic system. The research we have done suggests that in small cities with undeveloped traffic systems, the most effective measure to achieve urban low-carbon traffic is to increase the comprehensive costs of high-carbon travel. However, in big cities with developed traffic systems, raising low-carbon awareness of residents can greatly increase the proportion of low-carbon travelers and improve the stability of travel mode choice. The results could provide development strategies and policy suggestions for urban low-carbon traffic and reduce the adverse impact of urban traffic emissions on public health.


Assuntos
Poluentes Atmosféricos , Emissões de Veículos , Poluentes Atmosféricos/análise , Carbono/análise , Cidades , Teoria do Jogo , Emissões de Veículos/análise
5.
PLoS Biol ; 19(2): e3001090, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33591965

RESUMO

Sweating is a basic skin function in body temperature control. In sweat glands, salt excretion and reabsorption are regulated to avoid electrolyte imbalance. To date, the mechanism underlying such regulation is not fully understood. Corin is a transmembrane protease that activates atrial natriuretic peptide (ANP), a cardiac hormone essential for normal blood volume and pressure. Here, we report an unexpected role of corin in sweat glands to promote sweat and salt excretion in regulating electrolyte homeostasis. In human and mouse eccrine sweat glands, corin and ANP are expressed in the luminal epithelial cells. In corin-deficient mice on normal- and high-salt diets, sweat and salt excretion is reduced. This phenotype is associated with enhanced epithelial sodium channel (ENaC) activity that mediates Na+ and water reabsorption. Treatment of amiloride, an ENaC inhibitor, normalizes sweat and salt excretion in corin-deficient mice. Moreover, treatment of aldosterone decreases sweat and salt excretion in wild-type (WT), but not corin-deficient, mice. These results reveal an important regulatory function of corin in eccrine sweat glands to promote sweat and salt excretion.


Assuntos
Glândulas Écrinas/fisiologia , Serina Endopeptidases/metabolismo , Cloreto de Sódio/metabolismo , Animais , Fator Natriurético Atrial/metabolismo , Glândulas Écrinas/metabolismo , Eletrólitos/metabolismo , Folículo Piloso/metabolismo , Homeostase/fisiologia , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Serina Endopeptidases/genética , Suor/química , Água/metabolismo
6.
Cell Metab ; 33(2): 258-269.e3, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33421384

RESUMO

Corticosteroid therapy is now recommended as a treatment in patients with severe COVID-19. But one key question is how to objectively identify severely ill patients who may benefit from such therapy. Here, we assigned 12,862 COVID-19 cases from 21 hospitals in Hubei Province equally to a training and a validation cohort. We found that a neutrophil-to-lymphocyte ratio (NLR) > 6.11 at admission discriminated a higher risk for mortality. Importantly, however, corticosteroid treatment in such individuals was associated with a lower risk of 60-day all-cause mortality. Conversely, in individuals with an NLR ≤ 6.11 or with type 2 diabetes, corticosteroid treatment was not associated with reduced mortality, but rather increased risks of hyperglycemia and infections. These results show that in the studied cohort corticosteroid treatment is associated with beneficial outcomes in a subset of COVID-19 patients who are non-diabetic and with severe symptoms as defined by NLR.


Assuntos
Corticosteroides/uso terapêutico , COVID-19/tratamento farmacológico , Linfócitos/citologia , Neutrófilos/citologia , Corticosteroides/efeitos adversos , Área Sob a Curva , COVID-19/mortalidade , COVID-19/patologia , COVID-19/virologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/patologia , Humanos , Hiperglicemia/complicações , Hiperglicemia/patologia , Tempo de Internação , Modelos de Riscos Proporcionais , Curva ROC , Fatores de Risco , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de Doença , Taxa de Sobrevida , Resultado do Tratamento
7.
Biochem Biophys Res Commun ; 530(1): 35-41, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32828311

RESUMO

Corin is a transmembrane serine protease that activates atrial natriuretic peptide, a cardiac hormone essential for normal blood pressure. Corin is synthesized as a zymogen and activated on the cell surface. In previous studies, we identified a CORIN variant allele with an adenine insertion in the 5'-end of the coding region in ∼5% of hypertensive individuals in a Chinese population. The protein, named insA, encoded by the CORIN variant allele has a shortened cytoplasmic tail and reduced atrial natriuretic peptide processing activity. It remains unknown how a shortened cytoplasmic tail impairs corin function. In this study, we expressed a series of corin mutants with different N-terminal sequences and analyzed them by Western blotting, flow cytometry, protein chase, and immunostaining. Our results revealed that a Gly-Asn sequence after the initiating Met at the newly generated N-terminus was responsible for delaying corin trafficking in the Golgi. Deletion of the N-terminal Gly and Asn residues increased the intracellular trafficking, cell surface expression, and activation cleavage of the insA variant. These results help to explain how the CORIN variant allele impairs corin structure and function as an underlying mechanism in hypertension.


Assuntos
Hipertensão/metabolismo , Serina Endopeptidases/metabolismo , Células HEK293 , Humanos , Hipertensão/genética , Mutação , Domínios Proteicos , Transporte Proteico , Serina Endopeptidases/análise , Serina Endopeptidases/genética
8.
Proc Natl Acad Sci U S A ; 117(32): 19425-19434, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32719113

RESUMO

Spiral artery remodeling is an important physiological process in the pregnant uterus which increases blood flow to the fetus. Impaired spiral artery remodeling contributes to preeclampsia, a major disease in pregnancy. Corin, a transmembrane serine protease, is up-regulated in the pregnant uterus to promote spiral artery remodeling. To date, the mechanism underlying uterine corin up-regulation remains unknown. Here we show that Krüppel-like factor (KLF) 17 is a key transcription factor for uterine corin expression in pregnancy. In cultured human uterine endometrial cells, KLF17 binds to the CORIN promoter and enhances the promoter activity. Disruption of the KLF17 gene in the endometrial cells abolishes CORIN expression. In mice, Klf17 is up-regulated in the pregnant uterus. Klf17 deficiency prevents uterine Corin expression in pregnancy. Moreover, Klf17-deficient mice have poorly remodeled uterine spiral arteries and develop gestational hypertension and proteinuria. Together, our results reveal an important function of KLF17 in regulating Corin expression and uterine physiology in pregnancy.


Assuntos
Artérias/fisiologia , Serina Endopeptidases/genética , Fatores de Transcrição/metabolismo , Útero/fisiologia , Animais , Células Cultivadas , Feminino , Fertilidade/genética , Regulação da Expressão Gênica , Humanos , Hipertensão Induzida pela Gravidez/genética , Masculino , Camundongos , Camundongos Knockout , Gravidez , Regiões Promotoras Genéticas , Proteinúria/genética , Serina Endopeptidases/metabolismo , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , Útero/irrigação sanguínea , Útero/metabolismo , Remodelação Vascular
9.
Cell Biochem Biophys ; 78(3): 255-265, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32623640

RESUMO

Patients with myocardial ischemic diseases or who are undergoing one of various heart treatments, such as open heart surgery, coronary artery bypass grafting, percutaneous coronary artery intervention or drug thrombolysis, face myocardial ischemia-reperfusion injury (MIRI). However, no effective treatment is currently available for MIRI. To improve the prognosis of people with cardiovascular disease, it is important to research the mechanism of MIRI. Arachidonic acid (AA) is one of the focuses of current research. The various metabolic pathways of AA are closely related to the development of cardiovascular disease, and the roles of various metabolites in ischemia-reperfusion injury have gradually been confirmed. AA is mainly metabolized in the cyclooxygenase (COX) pathway, lipoxygenase (LOX) pathway, and cytochrome P450 monooxygenase (CYP) pathway. This paper summarizes the progress of research on these three major AA metabolic pathways with respect to MIRI.


Assuntos
Ácido Araquidônico/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão/patologia , Animais , Apoptose , Autofagia , Cálcio/metabolismo , Citocromo P-450 CYP4A , Humanos , Sistema Imunitário , Inflamação , Camundongos , Estresse Oxidativo , Prognóstico
10.
J Mater Chem B ; 8(13): 2627-2635, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32129372

RESUMO

Radiotherapy is a commonly used method for curing cancers that appear on or just below the skin. Because of the dose build-up effect of X-rays, boluses made of various materials such as silica and wax are clinically applied on patients to increase the skin dose for an enhanced therapeutic effect. However, these commercial boluses can't conform well to the skin's surface with some curvature, resulting in radiation dose attenuation/loss at the lesion location. To address this limitation, we have developed a nano-titanium dioxide (nTiO2)-incorporated polyurethane/polyacrylamide (TPU/PAAm) hydrogel with multi-functions for fabricating a desirable bolus. The obtained hydrogel exhibits excellent mechanical, adhesive and self-healing properties and can fit closely to the surface of patients with any 3D curvature, eliminating the air gap which is a common problem for commercial boluses applied on patients. In particular, it is encouraging that when using the bolus made of TPU/PAAm hydrogel, the dose distribution including dose coverage, conformability and homogeneity within the planning target volume (PTV) is far superior to that when using the commercial bolus. A sufficient dose shifts toward the surface of the head model and is located only in the lesion site, demonstrating that TPU-PAAm hydrogel can provide an optimal dose distribution and be clinically effective for treating superficial tumors. Furthermore, nTiO2 particles feature uniform dispersion at the nanometer level in hydrogel after being modified by 2,2-bis(hydroxymethyl)propionic acid (DMPA) based on coordination chemistry, endowing the hydrogel with long-acting antibacterial ability. The good cell affinity of TPU-PAAm hydrogel is also confirmed in this study, further ensuring that the TPU-PAAm hydrogel prepared here is a desirable candidate as a tissue equivalent with the advantages of convenient use and effectiveness in radiotherapy.


Assuntos
Adesivos/farmacologia , Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Hidrogéis/farmacologia , Neoplasias/radioterapia , Cicatrização/efeitos dos fármacos , Adesivos/síntese química , Adesivos/química , Animais , Antibacterianos/síntese química , Antibacterianos/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Linhagem Celular , Escherichia coli/efeitos dos fármacos , Humanos , Hidrogéis/síntese química , Hidrogéis/química , Camundongos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Suínos
11.
J Exp Bot ; 71(10): 3012-3023, 2020 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-32061090

RESUMO

Virus-induced flowering (VIF) exploits RNA or DNA viruses to express flowering time genes to induce flowering in plants. Such plant virus-based tools have recently attracted widespread attention for their fundamental and applied uses in flowering physiology and in accelerating breeding in dicotyledonous crops and woody fruit-trees. We now extend this technology to a monocot grass and a cereal crop. Using a Foxtail mosaic virus (FoMV)-based VIF system, dubbed FoMViF, we showed that expression of florigenic Flowering Locus T (FT) genes can promote early flowering and spikelet development in proso millet, a C4 grass species with potential as a nutritional food and biofuel resource, and in non-vernalized C3 wheat, a major food crop worldwide. Floral and spikelet/grain induction in the two monocot plants was caused by the virally expressed untagged or FLAG-tagged FT orthologs, and the florigenic activity of rice Hd3a was more pronounced than its dicotyledonous counterparts in proso millet. The FoMViF system is easy to use and its efficacy to induce flowering and early spikelet/grain production is high. In addition to proso millet and wheat, we envisage that FoMViF will be also applicable to many economically important monocotyledonous food and biofuel crops.


Assuntos
Melhoramento Vegetal , Potexvirus , Produtos Agrícolas/genética , Triticum
12.
Bio Protoc ; 9(11)2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31528665

RESUMO

Extracellular expression is essential for the function of secreted and cell surface proteins. Proper intracellular trafficking depends on protein interactions in multiple subcellular compartments. Co-immunoprecipitation and the yeast two-hybrid system are commonly used to investigate protein-protein interactions. These methods, however, depend on high-affinity protein interactions. In many glycoproteins, glycans are important for protein intracellular trafficking and extracellular expression. If glycoprotein interactions are transient and relatively weak, it may be challenging to use co-immunoprecipitation or the two-hybrid system to identify glycoprotein-binding partners. To circumvent this problem, protein cross-linking can be applied first to immobilize the transient and/or low-affinity protein interactions. Here we describe a protocol of protein cross-linking, co-immunoprecipitation, and proteomic analysis, which was used to identify endoplasmic reticulum (ER) chaperones critical for the folding and ER exiting of N-glycosylated serine proteases in human embryonic kidney (HEK) 293 cells. This approach can be used to identify other protein interactions in a variety of cells.

13.
Res Vet Sci ; 125: 390-396, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31412308

RESUMO

Cold-stress causes disturbance of the homeostatic regulation of animals, and gradually impairs the immune and antioxidant functions of animals. Therefore, increasing the effectiveness of the immune response and antioxidant function are the most attractive strategies against cold-stress. Kaempferol (KPF) exerts both an anti-inflammatory and antioxidant pharmacological effect. However, nor much is known of the effects of KPF on providing protection from cold-induced intestinal oxidative damage and improving immunity. This study investigated the effects of KPF on immune factors and intestinal antioxidation in the blood of cold-stressed mice. KPF was solubilized in diluted saline before administration. The mice were randomly divided into 4 groups: (1) control, (2) cold-stress, (3) KPF 25 mg/kg, and (4) cinnamon (CAM) 30 mg/kg groups. Groups (2)-(4) were exposed to cold stress once a day for 7 days. Cold-stress was achieved by exposing the mice to a temperature of -15 °C and 70 ±â€¯10% humidity for 60 min, once a day. The histopathological changes in the small intestine of the mice were analyzed. The T lymphocyte populations in blood were measured using flow cytometry. The level of SLC6a4, 5-HT3 and 5-HTT in small intestine tissue was assessed using RT-PCR analysis. Cow blood samples were obtained for the hematological analysis. Kaempferol (KPF) (25 mg/kg) regularized the intestinal antioxidant activity in the cold stress animals. KPF was able to significantly (P < .05) return intestinal SLC6a4, 5-HT3 and 5-HTT levels to normal after it had increased due to cold-stress. KPF treatment prevented the cold stress-induced decrease in blood CD4+T cells and decrease CD8+T cells levels in mice. Improved hematological profiles were additionally observed on treatment cows with KPF. KPF compared favorably with cinnamon in cold stress management, suggesting cold stress disturbs the anti-inflammatory effect of KPF. Thus, KPF contributes to suppress the activated pro-inflammatory cytokines, IL-9, IL-13, CD8+T and neurochemicals, and to increase anti-inflammatory cytokines and CD4+T levels.


Assuntos
Anti-Inflamatórios/farmacologia , Temperatura Baixa/efeitos adversos , Resposta ao Choque Frio/efeitos dos fármacos , Quempferóis/farmacologia , Animais , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Cinnamomum zeylanicum , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Homeostase , Intestinos/efeitos dos fármacos , Camundongos , Distribuição Aleatória
14.
Microb Pathog ; 134: 103557, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31153984

RESUMO

Escherichia coli (E. coli) O1-induced diarrhea is associated with intestinal microbial imbalance, however, the results of using oral antibiotics still remain poor. To overcome such problem, our study investigates the role of metabolites from stable flies (MSF) in the occurrence of diarrhea. The amino acid composition and molecular weight analysis of MSF by RP-HPLC and GPC, respectively. Besides the normal control group, SPF mice in other group were inoculated with E. coli O1 received treatment as follows over a period of 7 days saline solution (E. coli control), ciprofloxacin (0.13 g/kg; positive control) and MSF (2, 4 and 8 mg/kg) dosage. Throughout the experiment, defecation and body weights were examined and recorded. On the eighth day, after administering anesthesia, blood, tissue of small intestine samples were obtained for immunological and anti-oxidant. Small intestinal tissues and cecum contents samples were used for histopathological and 16S rDNA sequencing analysis. Our showed that MSF was rich in isoleucine, and its molecular weight less than 400 Da is 60.03%. MSF (4 and 8 mg/kg) and ciprofloxacin, significantly decreased IL-6, IL-8 and TNF-α levels, whereas, increased IL-2, IL-4, IL-10, INF-γ, IgA and IgG levels in mice having diarrhea. These treatments also reversed intestinal flora imbalance as indicated by the increased in Firmicutes-to-Bacteroidetes ratio and Clostridium levels (P < 0.05) and improved 5-HT, CAT and SOD levels. MSF favored diarrhea management as compared to ciprofloxacin, suggesting that MSF can be used in the management of E. coli O1-induced diarrhea, in normal gut microbiota and normal intestinal antioxidant function.


Assuntos
Diarreia/tratamento farmacológico , Sistema Imunitário/imunologia , Muscidae/química , Animais , Antioxidantes/uso terapêutico , Peso Corporal , Ceco , Ciprofloxacina/farmacologia , Citocinas/sangue , Citocinas/metabolismo , Diarreia/patologia , Diarreia/prevenção & controle , Modelos Animais de Doenças , Escherichia coli Enterotoxigênica/imunologia , Infecções por Escherichia coli/patologia , Microbioma Gastrointestinal/efeitos dos fármacos , Intestino Delgado , Intestinos/efeitos dos fármacos , Intestinos/patologia , Larva/química , Masculino , Camundongos
15.
Sci Rep ; 9(1): 4235, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30862835

RESUMO

Anaplasma phagocytophilum, the aetiologic agent of human granulocytic anaplasmosis (HGA) is an obligate intracellular Gram-negative bacterium with the genome size of 1.47 megabases. The intracellular life style and small size of genome suggest that A. phagocytophilum has to modulate a multitude of host cell physiological processes to facilitate its replication. One strategy employed by A. phagocytophilum is through its type IV secretion system (T4SS), which translocates bacterial effectors into target cells to disrupt normal cellular activities. In this study we developed a TEM-1 ß-lactamase based protein translocation assay and applied this assay for identification of A. phagocytophilum T4SS effectors. An A. phagocytophilum hypothetical protein, APH0215 is identified as a T4SS effector protein and found interacting with trans-Golgi network in transfected cells. Hereby, this protein translocation assay developed in this study will facilitate the identification of A. phagocytophilum T4SS effectors and elucidation of HGA pathogenesis.


Assuntos
Anaplasma phagocytophilum , Anaplasmose , Proteínas de Bactérias , Bioensaio , beta-Lactamases , Anaplasma phagocytophilum/genética , Anaplasma phagocytophilum/metabolismo , Anaplasmose/diagnóstico , Anaplasmose/genética , Anaplasmose/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Células CHO , Cricetinae , Cricetulus , Humanos , Sistemas de Secreção Tipo IV/genética , Sistemas de Secreção Tipo IV/metabolismo , beta-Lactamases/genética , beta-Lactamases/metabolismo
16.
Am J Reprod Immunol ; 81(5): e13096, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30681748

RESUMO

PROBLEM: The Staphylococcus aureus has been found to be associated with clinical endometritis of cow. The result of oral antibiotic remains poor. Therefore, this study investigates the role of nisin in endometritis. METHOD OF STUDY: The effect of nisin on the growth and cell wall of S aureus were determined in vitro. Besides the blank control group, animals with established post-partum were inoculated with 0.1 mL S aureus intravaginally. Two days post-inoculation, the animals were administered nisin (25 mg/kg), kanamycin (30 mg/kg), and water (model group) for 7 days. On the seventh day, serum and uterine organs were obtained for pro- and anti-inflammatory analysis. The uterine tissue samples were weighed, and histopathological analysis was performed. RESULTS: The results showed that nisin had an inhibitory effect on the growth and cell wall formation of S aureus. Nisin and kanamycin treatment prevented a S aureus-induced decrease in pro-inflammatory cytokines and promoted an increase in the level of serum anti-inflammatory cytokines in the endometrium of these animals. Nisin and kanamycin, significantly decreased (P < 0.05) the endometritis-induced increases in uterine weight, restored endometrial architecture and significantly (P < 0.05) normalized uterine neutrophils to control levels. Additionally, improved levels of B7-2 , IFN-γ, IL-2, and IL-8 were observed when treated with nisin. CONCLUSION: Our findings suggest that nisin compared favorably with kanamycin in endometritis prevention, suggesting that nisin can be used in S aureus-induced endometritis by protecting the uterus from S aureus infection.


Assuntos
Antibacterianos/uso terapêutico , Endometrite/metabolismo , Células Epiteliais/fisiologia , Nisina/uso terapêutico , Infecções Estafilocócicas/metabolismo , Staphylococcus aureus/fisiologia , Animais , Bovinos , Células Cultivadas , Feminino , Inflamação , Canamicina/uso terapêutico , Ratos , Ratos Sprague-Dawley , Virulência/genética
17.
Hepatology ; 69(4): 1564-1581, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30015413

RESUMO

B-cell lymphoma 2 (Bcl-2)-associated transcription factor 1 (Bclaf1) is known to be involved in diverse biological processes, but, to date, there has been no evidence for any functional role of Bclaf1 in hepatocellular carcinoma (HCC) progression. Here, we demonstrate that Bclaf1 is frequently up-regulated in HCC and that Bclaf1 up-regulation is associated with Edmondson grade, lower overall survival rates, and poor prognosis. Overexpression of Bclaf1 in HCC cell lines HepG2 and Huh7 promoted proliferation considerably, whereas Bclaf1 knockdown had the opposite effect. Xenograft tumors grown from Bclaf1 knockdown Huh7 cells had smaller tumor volumes than tumors grown from control cells. Furthermore, our study describes MYC proto-oncogene (c-Myc) as a downstream target of Bclaf1, given that Bclaf1 regulates c-MYC expression posttranscriptionally by its RS domain. To exert this function, Bclaf1 must interact with the molecular chaperone, heat shock protein 90 alpha (Hsp90α). In HCC tissue samples, Hsp90α levels were also increased significantly and Hsp90α-Bclaf1 interaction was enhanced. Bclaf1 interacts with the C-terminal domain of Hsp90α, and this interaction is disrupted by the C-terminal domain inhibitor, novobiocin (NB), resulting in proteasome-dependent degradation of Bclaf1. Moreover, NB-induced disruption of Hsp90α-Bclaf1 interaction dampened the production of mature c-MYC mRNA and attenuated tumor cell growth in vitro and in vivo. Conclusion: Our findings suggest that Bclaf1 affects HCC progression by manipulating c-MYC mRNA stability and that the Hsp90α/Bclaf1/c-Myc axis might be a potential target for therapeutic intervention in HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Repressoras/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/mortalidade , China/epidemiologia , Feminino , Genes myc , Proteínas de Choque Térmico HSP90/metabolismo , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/mortalidade , Masculino , Camundongos Nus , Pessoa de Meia-Idade , Estabilidade Proteica
18.
Oncogene ; 38(11): 1845-1859, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30367150

RESUMO

The development of hepatocellular carcinomas (HCC) depends on their local microenvironment and the induction of neovascularization is a decisive step in tumor progression, since the growth of solid tumors is limited by nutrient and oxygen supply. Hypoxia is the critical factor that induces transcription of the hypoxia inducible factor-1α (HIF-1α) encoding gene HIF1A and HIF-1α protein accumulation to promote angiogenesis. However, the basis for the transcriptional regulation of HIF1A expression in HCC is still unclear. Here, we show that Bclaf1 levels are highly correlated with HIF-1α levels in HCC tissues, and that knockdown of Bclaf1 in HCC cell lines significantly reduces hypoxia-induced HIF1A expression. Furthermore, we found that Bclaf1 promotes HIF1A transcription via its bZIP domain, leading subsequently to increased transcription of the HIF-1α downstream targets VEGFA, TGFB, and EPO that in turn promote HCC-associated angiogenesis and thus survival and thriving of HCC cells. Moreover, we demonstrate that HIF-1α levels and microvessel density decrease after the shRNA-mediated Bclaf1 knockdown in xenograft tumors. Finally, we found that Bclaf1 levels increase in hypoxia in a HIF-1α dependent manner. Therefore, our study identifies Bclaf1 as a novel positive regulator of HIF-1α in the hypoxic microenvironment, providing new incentives for promoting Bcalf1 as a potential therapeutic target for an anti-HCC strategy.


Assuntos
Carcinoma Hepatocelular/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neoplasias Hepáticas/genética , Neovascularização Patológica/genética , Proteínas Repressoras/fisiologia , Proteínas Supressoras de Tumor/fisiologia , Animais , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/patologia , Hipóxia Celular/genética , Células Cultivadas , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Células Endoteliais da Veia Umbilical Humana , Humanos , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Patológica/patologia , Transcrição Genética , Microambiente Tumoral/genética
19.
Water Res ; 150: 216-224, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30528918

RESUMO

Metabolic division of labor is a key ecological strategy in bacteria to allow concurrent execution of multiple tasks through functional differentiation and metabolite exchange. While it is prevalent in nature, a lot of novel interactions remain to be further explored for improved wastewater biological treatment. Here, we present a combined experimental and modeling study on the simultaneous removal of nitrogen and thiocyanate from wastewater by using a syntrophic microbial community. The syntrophic division of labor was achieved by coupling autotrophic denitrification (AD) and anaerobic ammonium oxidation (AN) through both cooperative and competitive interactions. We demonstrated that the syntrophic community can achieve almost complete removal of all pollutants under certain initial conditions. We then perturbed the initial condition by varying the concentration ratio between ammonium to thiocyanate as well as the biomass ratio between AD and AN. Our observations show that adding ammonium negatively impacts the thiocyanate removal efficiency and adding anammox bacteria have opposite effects on the removal efficiency of thiocyanate and ammonium. Using a mathematical model, we simultaneously varied these two initial conditions and identified the parameter regime where our syntrophic ecosystem can be most efficient in removing total nitrogen. By highlighting the utility of syntrophic pair of functional bacteria in removing pollutants, our study will facilitate the rational design of more complex microbial consortia for the removal of toxic and hazardous compounds from industrial wastewater.


Assuntos
Compostos de Amônio , Águas Residuárias , Anaerobiose , Reatores Biológicos , Ecossistema , Nitrogênio , Oxirredução , Tiocianatos
20.
Microb Pathog ; 125: 183-188, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30217516

RESUMO

Human granulocytic anaplasmosis (HGA), an increasingly recognized febrile tick-borne illness, is caused by a gram-negative obligate intracellular bacterium Anaplasma phagocytophilum. Because of nonspecific clinical manifestations, diagnosis of HGA highly depends on laboratory tests. Identification of immunoreactive proteins is prerequisite for development of specific and sensitive immunoassays for HGA. In this study, we identified novel immunoreactive proteins of A. phagocytophilum. Previous studies indicated that secreted proteins of A. phagocytophilum and other bacteria can be immunoreactive antigens. Here we in silico screened A. phagocytophilum genome for encoding proteins which bear features of type IV secretion system substrates. Among seventy seven predicted proteins, fourteen proteins were determined for antigenicity and nine proteins were showed to be immunoreactive antigens. In addition, an APH1384 peptide harboring a B cell epitope predicted by bioinformatics was found specifically reacting with anti-A. phagocytophilum sera. Hereby, we identified novel immunoreactive proteins and delineated a specific epitope of A. phagocytophilum, which might be employed for HGA diagnosis.


Assuntos
Anaplasma phagocytophilum/imunologia , Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/imunologia , Ehrlichiose/diagnóstico , Epitopos/imunologia , Anaplasma phagocytophilum/genética , Proteínas de Bactérias/genética , Biologia Computacional , Ehrlichiose/imunologia , Epitopos/genética , Humanos , Fatores de Virulência/genética , Fatores de Virulência/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...