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1.
PLoS Biol ; 21(12): e3002433, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38091366

RESUMO

The emerging and global spread of a novel plasmid-mediated colistin resistance gene, mcr-1, threatens human health. Expression of the MCR-1 protein affects bacterial fitness and this cost correlates with lipid A perturbation. However, the exact molecular mechanism remains unclear. Here, we identified the MCR-1 M6 variant carrying two-point mutations that conferred co-resistance to ß-lactam antibiotics. Compared to wild-type (WT) MCR-1, this variant caused severe disturbance in lipid A, resulting in up-regulation of L, D-transpeptidases (LDTs) pathway, which explains co-resistance to ß-lactams. Moreover, we show that a lipid A loading pocket is localized at the linker domain of MCR-1 where these 2 mutations are located. This pocket governs colistin resistance and bacterial membrane permeability, and the mutated pocket in M6 enhances the binding affinity towards lipid A. Based on this new information, we also designed synthetic peptides derived from M6 that exhibit broad-spectrum antimicrobial activity, exposing a potential vulnerability that could be exploited for future antimicrobial drug design.


Assuntos
Colistina , Proteínas de Escherichia coli , Humanos , Colistina/farmacologia , Antibacterianos/farmacologia , Antibióticos beta Lactam , Lipídeo A , Peptídeos Antimicrobianos , Monobactamas , Plasmídeos , Farmacorresistência Bacteriana/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Testes de Sensibilidade Microbiana
2.
J Biol Chem ; 300(4): 107208, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38521502

RESUMO

Transforming growth factor-ß (TGF-ß) and Hippo signaling are two critical pathways engaged in cancer progression by regulating both oncogenes and tumor suppressors, yet how the two pathways coordinately exert their functions in the development of hepatocellular carcinoma (HCC) remains elusive. In this study, we firstly conducted an integrated analysis of public liver cancer databases and our experimental TGF-ß target genes, identifying CYR61 as a pivotal candidate gene relating to HCC development. The expression of CYR61 is downregulated in clinical HCC tissues and cell lines than that in the normal counterparts. Evidence revealed that CYR61 is a direct target gene of TGF-ß in liver cancer cells. In addition, TGF-ß-stimulated Smad2/3 and the Hippo pathway downstream effectors YAP and TEAD4 can form a protein complex on the promoter of CYR61, thereby activating the promoter activity and stimulating CYR61 gene transcription in a collaborative manner. Functionally, depletion of CYR61 enhanced TGF-ß- or YAP-mediated growth and migration of liver cancer cells. Consistently, ectopic expression of CYR61 was capable of impeding TGF-ß- or YAP-induced malignant transformation of HCC cells in vitro and attenuating HCC xenograft growth in nude mice. Finally, transcriptomic analysis indicates that CYR61 can elicit an antitumor program in liver cancer cells. Together, these results add new evidence for the crosstalk between TGF-ß and Hippo signaling and unveil an important tumor suppressor function of CYR61 in liver cancer.


Assuntos
Carcinoma Hepatocelular , Proteína Rica em Cisteína 61 , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas , Fator de Crescimento Transformador beta , Proteínas de Sinalização YAP , Animais , Humanos , Camundongos , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Movimento Celular , Proteína Rica em Cisteína 61/metabolismo , Proteína Rica em Cisteína 61/genética , Mineração de Dados , Regulação Neoplásica da Expressão Gênica/genética , Via de Sinalização Hippo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/genética , Camundongos Nus , Regiões Promotoras Genéticas , Transdução de Sinais/genética , Proteína Smad2/metabolismo , Proteína Smad2/genética , Proteína Smad3/metabolismo , Proteína Smad3/genética , Fatores de Transcrição de Domínio TEA/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta/genética , Regulação para Cima , Proteínas de Sinalização YAP/metabolismo , Proteínas de Sinalização YAP/genética
3.
Int J Mol Sci ; 25(10)2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38791345

RESUMO

Doxorubicin (DOX) is a potent chemotherapeutic agent known for its multi-organ toxicity, especially in the heart, which limits its clinical application. The toxic side effects of DOX, including DNA damage, oxidative stress, mitochondrial dysfunction and cell apoptosis, are intricately linked to the involvement of nicotinamide adenine dinucleotide (NAD+). To assess the effectiveness of the NAD+ precursor nicotinamide mononucleotide (NMN) in counteracting the multi-organ toxicity of DOX, a mouse model was established through DOX administration, which led to significant reductions in NAD+ in tissues with evident injury, including the heart, liver and lungs. NMN treatment alleviated both multi-organ fibrosis and mortality in mice. Mechanistically, tissue fibrosis, macrophage infiltration and DOX-related cellular damage, which are potentially implicated in the development of multi-organ fibrosis, could be attenuated by NAD+ restoration. Our findings provide compelling evidence for the benefits of NMN supplementation in mitigating the adverse effects of chemotherapeutic drugs on multiple organs.


Assuntos
Doxorrubicina , Fibrose , Mononucleotídeo de Nicotinamida , Animais , Doxorrubicina/efeitos adversos , Mononucleotídeo de Nicotinamida/farmacologia , Camundongos , Suplementos Nutricionais , Masculino , NAD/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia
4.
Int J Mol Sci ; 25(11)2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38892031

RESUMO

Copy number variations (CNVs) critically influence individual genetic diversity and phenotypic traits. In this study, we employed whole-genome resequencing technology to conduct an in-depth analysis of 50 pigs from five local swine populations [Rongchang pig (RC), Wuzhishan pig (WZS), Tibetan pig (T), Yorkshire (YL) and Landrace (LR)], aiming to assess their genetic potential and explore their prospects in the field of animal model applications. We identified a total of 96,466 CNVs, which were subsequently integrated into 7112 non-redundant CNVRs, encompassing 1.3% of the swine genome. Functional enrichment analysis of the genes within these CNVRs revealed significant associations with sensory perception, energy metabolism, and neural-related pathways. Further selective scan analyses of the local pig breeds RC, T, WZS, along with YL and LR, uncovered that for the RC variety, the genes PLA2G10 and ABCA8 were found to be closely related to fat metabolism and cardiovascular health. In the T breed, the genes NCF2 and CSGALNACT1 were associated with immune response and connective tissue characteristics. As for the WZS breed, the genes PLIN4 and CPB2 were primarily linked to fat storage and anti-inflammatory responses. In summary, this research underscores the pivotal role of CNVs in fostering the diversity and adaptive evolution of pig breeds while also offering valuable insights for further exploration of the advantageous genetic traits inherent to China's local pig breeds. This facilitates the creation of experimental animal models tailored to the specific characteristics of these breeds, contributing to the advancement of livestock and biomedical research.


Assuntos
Variações do Número de Cópias de DNA , Sequenciamento Completo do Genoma , Animais , Variações do Número de Cópias de DNA/genética , Suínos/genética , Sequenciamento Completo do Genoma/métodos , China , Cruzamento , Variação Genética , Genoma , Evolução Molecular
5.
Molecules ; 29(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38675651

RESUMO

Outer membrane vesicles (OMVs) are attractive for biomedical applications based on their intrinsic properties in relation to bacteria and vesicles. However, their widespread use is hampered by low yields and purities. In this study, EVscore47 multifunctional chromatography microspheres were synthesized and used to efficiently isolate functional OMVs from Escherichia coli. Through this technology, OMV loss can be kept to a minimum, and OMVs can be harvested using EVscore47 at 11-fold higher yields and ~13-fold higher purity than those achieved by means of ultracentrifugation. Based on the results presented here, we propose a novel EVscore47-based isolation of OMVs that is fast and scalable.


Assuntos
Escherichia coli , Vesículas Extracelulares , Microesferas , Vesículas Extracelulares/química , Vesículas Extracelulares/metabolismo , Membrana Externa Bacteriana/metabolismo , Proteínas da Membrana Bacteriana Externa/química , Ultracentrifugação , Cromatografia/métodos
6.
Breast Cancer Res ; 25(1): 38, 2023 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-37029374

RESUMO

BACKGROUND: Radiotherapy is widely applied in breast cancer treatment, while radiotherapy resistance is inevitable. TGF-ß1 has been considered to be an endogenous factor for the development of radiotherapy resistance. As a large portion of TGF-ß1 is secreted in an extracellular vesicles-associated form (TGF-ß1EV), particularly in radiated tumors. Thus, the understanding of the regulation mechanisms and the immunosuppressive functions of TGF-ß1EV will pave a way for overcoming the radiotherapy resistance in cancer treatment. METHODS: The superoxide-Zinc-PKC-ζ-TGF-ß1EV pathway in breast cancer cells was identified through sequence alignments of different PKC isoforms, speculation and experimental confirmation. A series of functional and molecular studies were performed by quantitative real-time PCR, western blot and flow cytometry analysis. Mice survival and tumor growth were recorded. Student's t test or two-way ANOVA with correction was used for comparisons of groups. RESULTS: The radiotherapy resulted in an increased expression of the intratumoral TGF-ß1 and an enhanced infiltration of the Tregs in the breast cancer tissues. The intratumoral TGF-ß1 was found mainly in the extracellular vesicles associated form both in the murine breast cancer model and in the human lung cancer tissues. Furthermore, radiation induced more TGF-ß1EV secretion and higher percentage of Tregs by promoting the expression and phosphorylation of protein kinase C zeta (PKC-ζ). Importantly, we found that naringenin rather than 1D11 significantly improved radiotherapy efficacy with less side effects. Distinct from TGF-ß1 neutralizing antibody 1D11, the mechanism of naringenin was to downregulate the radiation-activated superoxide-Zinc-PKC-ζ-TGF-ß1EV pathway. CONCLUSIONS: The superoxide-zinc-PKC-ζ-TGF-ß1EV release pathway was elucidated to induce the accumulation of Tregs, resulting in radiotherapy resistance in the TME. Therefore, targeting PKC-ζ to counteract TGF-ß1EV function could represent a novel strategy to overcome radiotherapy resistance in the treatment of breast cancer or other cancers. TRIAL REGISTRATION: The using of patient tissues with malignant Non-Small Cell Lung Cancer (NSCLC) was approved by the ethics committees at Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China (NCC2022C-702, from June 8th, 2022).


Assuntos
Neoplasias da Mama , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Proteína Quinase C , Fator de Crescimento Transformador beta1 , Animais , Feminino , Humanos , Camundongos , Neoplasias da Mama/genética , Neoplasias da Mama/radioterapia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia , Fosforilação , Superóxidos , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Proteína Quinase C/genética , Proteína Quinase C/metabolismo
7.
Anal Chem ; 94(2): 1308-1317, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34962779

RESUMO

Alterations in formaldehyde (FA) homeostasis are associated with the pathology of Alzheimer's disease (AD). In vivo tracking of FA flux is important for understanding the underlying molecular mechanisms, but is challenging due to the lack of sensitive probes favoring a selective, rapid, and reversible response toward FA. In this study, we re-engineered the promiscuous and irreversible phenylhydrazines to make them selective and reversible toward FA by tuning their nucleophilicity. This effort resulted in PFM309, a selective (selectivity coefficient KFA,methylglyoxal = 0.06), rapid (t1/2 = 32 s at [FA] = 200 µM), and reversible fluorogenic probe (K = 6.24 mM-1) that tracks the FA flux in both live cells and live mice. In vivo tracking of the FA flux was realized by PFM309 imaging, which revealed the gradual accumulation of FA in the live mice brain during normal aging and its further increase in AD mice. We further identified the age-dependent loss of catabolism enzymes ALDH2 and ADH5 as the primary mechanism responsible for formaldehyde excess. Activating ALDH2 with the small molecular activator Alda1 significantly protected neurovascular cells from formaldehyde overload and consequently from impairment during AD progress both in vitro and in vivo. These findings revealed PFM309 as a robust tool to study AD pathology and highlight ALDH2 as a potential target for AD drug development.


Assuntos
Doença de Alzheimer , Envelhecimento , Aldeído-Desidrogenase Mitocondrial/metabolismo , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Animais , Formaldeído/metabolismo , Camundongos
8.
Gynecol Endocrinol ; 38(1): 22-27, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34402730

RESUMO

OBJECTIVE: The present meta-analysis was conducted to investigate the association between circulating chemerin levels and polycystic ovary syndrome (PCOS) in women. METHODS: Relevant studies published up to May 2020 were searched from PubMed, Ovid, the Cochrane Library, and Clinical Trial Database. A random effects model was used to measure the strength of association between PCOS and chemerin by using the standardized mean difference (SMD) and 95% confidence interval (CI). All data were analyzed using Stata 12.0 (version 12; Stata-Corp, College Station, TX). RESULTS: The final meta-analysis included eight studies with 15 results including a total of 897 participants (524 patients with PCOS and 373 controls). The circulating chemerin levels were higher in patients with PCOS (random effects SMD = 1.07; 95% CI: 0.55-1.59; p < .001) than in controls. However, considerable heterogeneity across studies was not eliminated in subgroup analyses. The meta-regression analysis further suggested that region is the main source of heterogeneity (p = .001). CONCLUSIONS: Our meta-analysis indicated that women with PCOS have significantly higher circulating chemerin levels than in healthy women, indicating that chemerin may be involved in the pathogenesis of PCOS.


Assuntos
Proteínas Quimerinas/sangue , Síndrome do Ovário Policístico/sangue , Feminino , Humanos , Análise de Regressão
9.
Indian J Microbiol ; 62(3): 374-383, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35974910

RESUMO

Purpose: To investigated the changes of gut microbiome and fecal metabolome during anti-tuberculosis chemotherapy with isoniazid (H)-rifampin (R)-pyrazinamide (Z)-ethambutol (E). Patients and methods: (1) In this study, we recruited 168 stool specimens from 49 healthy volunteers without M. tuberculosis (Mtb), 30 healthy volunteers with latently infected by Mtb, 41 patients with active tuberculosis (ATB), 28 patients with 2-month HRZE treatment and 20 patients with 2-month HRZE followed by 4-month HR treatment. (2) We used 16S rRNA sequencing and an untargeted Liquid Chromatograph Mass Spectrometer-based metabolomics to investigate the changes of gut microbiome and the alteration of fecal metabolome, respectively, during anti-TB chemotherapy. Results: Mtb infection can reduce the diversity of intestinal flora of ATB patients and change their taxonomic composition, while the diversity of intestinal flora of ATB patients were restored during anti-TB chemotherapy. Especially, family Veillonellacea and Bateroidaceae and their genera Veillonella and Bacteroides significantly increased in the gut microbiota during anti-TB chemotherapy. Additionally, Mtb infection dynamically regulates fecal metabolism in ATB patients during anti-TB chemotherapy. Interestingly, the altered abundance of fecal metabolites correlated with the altered gut microbiota, especially the change of gut Clostridium, Bacteroides and Prevotella was closely related to the change of fecal metabolites such as Trans-4-Hydroxy-L-proline and Genistein caused by Mtb infection or anti-TB chemotherapy. Conclusion: Anti-TB chemotherapy with HRZE can disrupt both gut microbiotas and metabolome in ATB patients. Some specific genera and metabolites are depleted or enriched during anti-TB chemotherapy. Therefore, revealing potential relevance between gut microbiota and anti-TB chemotherapy will provide potential biomarkers for evaluating the therapeutic efficacy in ATB patients. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01003-2.

10.
Angew Chem Int Ed Engl ; 61(12): e202113972, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35029844

RESUMO

The electrochemical generation of vinyl carbocations from alkenyl boronic esters and boronates is reported. Using easy-to-handle nucleophilic fluoride reagents, these intermediates are trapped to form fully substituted vinyl fluorides. Mechanistic studies support the formation of dicoordinated carbocations through sequential single-electron oxidation events. Notably, this electrochemical fluorination features fast reaction times and Lewis acid-free conditions. This transformation provides a complementary method to access vinyl fluorides with simple fluoride salts such as TBAF.

11.
Soft Matter ; 17(17): 4594-4603, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33949604

RESUMO

Copolymerization is an effective approach to tailor the thermal and structural properties of liquid crystalline polymer materials, which is essential for various applications. In this work, two series of polynorbornene copolymers, A-r-B and A-r-C, with the biphenyl mesogenic side group at different substituent positions were synthesized via ring-opening metathesis polymerization in various compositions. The corresponding homopolymers A and C are liquid crystalline polymers, exhibiting an oblique columnar structure (Colob/p2) and lamellar structure, respectively, while homopolymer B is amorphous. The composition-dependent phase behaviors of copolymers were systematically studied with the combination of SAXS, GISAXS, AFM, DSC and POM techniques. With increasing molar content of A (xA), the self-organzied structure of copolymer A-r-B follows the sequence from amorphous to lamellar, undulated lamellar, and Colob/p2 structures, and that of A-r-C follows the sequence of lamellar, undulated lamellar, and Colob/p2 structures. Then, copolymers with undulated lamellar or Colob/p2 structures tend to enter lamellar phase first at higher temperature and then change to the isotropic state during heating. The composition-induced transition from lamellar to supramolecular columnar organization is somewhat reminiscent of block copolymers and other soft matter systems that can form ordered structures. Furthermore, the subsitituent number and position of rigid mesogenic units in the side chain can further modify the morphologies of self-organized phases.

12.
Stroke ; 51(2): 628-636, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31884905

RESUMO

Background and Purpose- Induction of hypothermia as a stroke therapy has been limited by logistical challenges. This study was designed to determine the hypothermic and neuroprotective efficacy of infusing cold saline directly into the internal jugular (IJ) vein and compare the effects of IJ hypothermia to those achieved by intracarotid artery hypothermia in an ischemic stroke model. Methods- The right middle cerebral artery was occluded in rats using an intraluminal filament. Immediately following reperfusion, hypothermia was achieved by infusing isotonic saline through microcatheter into the right IJ or right intracarotid over 30 minutes. Infarct sizes, neurological deficits, blood-brain barrier damage, edema volume, blood-brain barrier associated molecules (MMP-9 [matrix metallopeptidase 9] and AQP-4 [aquaporin 4]), and apoptosis-associated proteins (Bcl-2 and cleaved Caspase-3) were measured. Results- We found that both IJ- and intracarotid-based infusion cooled the brain robustly with a minimal effect on rectal temperatures. This brain cooling led to significantly reduced infarct volumes at 24 hours after reperfusion, as well as decreased expression of the proapoptotic protein cleaved Caspase-3 and increased expression of the antiapoptotic protein Bcl-2. Intracarotid and IJ cooling also aided in blood-brain barrier maintenance, as shown by decreased edema volumes, reduced Evans Blue leakage, and decreased expression of edema-facilitating proteins (MMP-9 and AQP-4). Both cooling methods then translated to preserved neurological function as determined by multiple functional tests over a 28-day observation period. Most importantly, the cooling and neuroprotective efficacy of IJ cooling was comparable to intracarotid cooling by almost every metric evaluated. Conclusions- Compared with intracarotid infusion, IJ infusion conferred a similar degree of hypothermia and neuroprotection following ischemic stroke. Given the ease of establishing vascular access via the internal jugular vein and the powerful neuroprotection that hypothermia provides, IJ brain cooling could be used as a promising hypothermia-induction modality going forward.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Hipotermia/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Modelos Animais de Doenças , Hipotermia/metabolismo , Hipotermia Induzida/métodos , Infarto da Artéria Cerebral Média/metabolismo , Ataque Isquêmico Transitório/tratamento farmacológico , Masculino , Ratos Sprague-Dawley
13.
FASEB J ; 33(1): 1496-1509, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29979631

RESUMO

Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) systems are prokaryotic adaptive immune systems against invading nucleic acids. CRISPR locus variability has been exploited in evolutionary and epidemiological studies of Mycobacterium tuberculosis, the causative agent of tuberculosis, for over 20 yr, yet the biological function of this type III-A system is largely unexplored. Here, using cell biology and biochemical, mutagenic, and RNA-seq approaches, we show it is active in invader defense and has features atypical of type III-A systems: mature CRISPR RNA (crRNA) in its crRNA-CRISPR/Cas protein complex are of uniform length (∼71 nt) and appear not to be subject to 3'-end processing after Cas6 cleavage of repeat RNA 8 nt from its 3' end. crRNAs generated resemble mature crRNA in type I systems, having both 5' (8 nt) and 3' (28 nt) repeat tags. Cas6 cleavage of repeat RNA is ion dependent, and accurate cleavage depends on the presence of a 3' hairpin in the repeat RNA and the sequence of its stem base nucleotides. This study unveils further diversity among CRISPR/Cas systems and provides insight into the crRNA recognition mechanism in M. tuberculosis, providing a foundation for investigating the potential of a type III-A-based genome editing system.-Wei, W., Zhang, S., Fleming, J., Chen, Y., Li, Z., Fan, S., Liu, Y., Wang, W., Wang, T., Liu, Y., Ren, B., Wang, M., Jiao, J., Chen, Y., Zhou, Y., Zhou, Y., Gu, S., Zhang, X., Wan, L., Chen, T., Zhou, L., Chen, Y., Zhang, X.-E., Li, C., Zhang, H., Bi, L. Mycobacterium tuberculosis type III-A CRISPR/Cas system crRNA and its maturation have atypical features.


Assuntos
Sistemas CRISPR-Cas , Mycobacterium tuberculosis/metabolismo , RNA Bacteriano/genética , Edição de Genes , Mycobacterium tuberculosis/genética , Análise de Sequência de RNA/métodos
14.
BMC Gastroenterol ; 20(1): 366, 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33143650

RESUMO

BACKGROUND: The occurrence of non-alcoholic fatty liver disease (NAFLD) is found to be higher in patients with obstructive sleep apnea (OSA), which is characterized by intermittent hypoxia. Activation of hypoxia-inducible factors has been shown in the development and progression of NAFLD, implying a cause and effects relationship between NAFLD and hypoxia. The present study was designed to investigate the interaction of lipotoxicity and hypoxia in the pathogenesis of NAFLD using mice model with high-fat diet (HFD) feeding or hypoxic treatment. METHODS: NAFLD model was induced in mice by HFD feeding, and in cultured primary hepatocytes by administration of palmitate acid. Mouse hypoxic model was produced by placing the mice in a Animal incubator with oxygen concentration at 75% followed by a 21% oxygen supplement. Hypoxic condition was mimicked by treating the hepatocytes with cobalt chloride (CoCl2) or 1% oxygen supply. Pimonidazole assay was conducted to evaluate hypoxia. Lipid metabolic genes were measured by real-time polymerase-chain reaction. HIF-1α and HIF-2α genes were silenced by siRNA. RESULTS: HFD feeding and palmitate acid treatment provoked severe hepatic hypoxia along with TG accumulation in mice and in cultured primary hepatocytes respectively. Conversely, hypoxia induced hepatic TG accumulation in mice and in cultured primary hepatocytes. Hypoxic treatment inhibited the expression of lipolytic genes, while increased the expression of lipogenicgenes in mice. Although both lipotoxicity and hypoxia could activate hepatic hypoxia-induced factor 1α and 2α, while neither lipotoxicity- nor hypoxia- induced hepatic steatosis was affected when HIF was knocked down. CONCLUSIONS: HFD resulted in hepatic TG accumulation and concomitant hypoxia. Conversely, hypoxia induced hepatic TG accumulation in mice and in cultured heptocytes. Thus lipotoxicity and hypoxia might work as reciprocal causation and orchestrate to promote the development of NAFLD.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Dieta Hiperlipídica/efeitos adversos , Hepatócitos , Humanos , Hipóxia , Fígado , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/etiologia
15.
Neurol Neurochir Pol ; 54(6): 561-567, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33047784

RESUMO

BACKGROUND: Tremor is one of the most common movement disorders. It does not usually respond to first-line drug treatments (e.g. propranolol, primidone, anticholinergics, gabapentin and clonazepam) due to side effects and frequent dose limitations. Botulinum toxin type A (BoNT-A) has been widely used to treat tremor, but its efficacy and safety are uncertain. AIMS: To evaluate the efficacy and safety of BoNT-A in the treatment of hand tremor. METHODS: We searched the MEDLINE, EMBASE, PsycINFO and Cochrane Library databases for relevant randomised controlled trials of the effects of BoNT-A injections on tremors, up to 20 February 2020. A meta-analysis of comparative effects was performed using R studio software, and publication bias was examined using Egger's test. RESULTS: Six studies examining a total of 245 participants with tremor were included in the meta-analysis. The primary outcome of meta-analysis showed no difference in clinical tremor scale scores between the BoNT-A group versus the placebo group (standardised mean difference (SMD): -0.42, 95% confidence interval (CI): -1.94 to 1.10; I2 = 96%). For clinical tremor scale scores, subgroup analyses suggested that the BoNT-A group may differ in terms of multiple sclerosis (MS) related tremor (SMD: -1.10; 95% CI: -2.17 to -0.04; I2 = 79%) compared to a placebo, but the difference did not exist in the outcome of essential tremor (ET) or hand tremor (MD: -1.31; 95% CI: -3.39; 1.31; I2 = 97%). Grip strength (MD: -1.25, 95% CI: -5.99 to 3.50, I2 = 97%) was slightly lower in the BoNT-A group, but the difference was not significant. The incidence of adverse events (AEs), including hand weakness (RR: 2.96, 95% CI: 1.40 to 6.24, I2 = 37%), was significantly greater in the BoNT-A group than in the placebo group. Two studies were assessed as having an overall low risk of bias. CONCLUSIONS: Our study confirms that BoNT-A injections are unlikely to have an impact on patients with hand tremors. However, subgroup analysis suggested that BoNT-A injections could have possible benefits in MS-related tremor. While moderate to severe hand weakness AEs often limits their use in clinical practice, additional well-designed double-blind, placebo-controlled trials are needed to provide more robust conclusions.


Assuntos
Toxinas Botulínicas Tipo A , Tremor , Toxinas Botulínicas Tipo A/uso terapêutico , Mãos/inervação , Humanos , Debilidade Muscular , Tremor/tratamento farmacológico
16.
Int J Med Microbiol ; 309(7): 151323, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31279617

RESUMO

Capreomycin (CAP), a cyclic peptide antibiotic, is considered to be an ideal second-line drug for tuberculosis (TB). However, in the past few years, the emergence of more CAP-resistant (CAPr) TB patients has limited its use. Although it has been reported that CAP resistance to Mycobacterium tuberculosis (Mtb) is associated with rrs or tlyA mutation, the exact mechanism of CAPr Mtb strains, especially the mechanism associated with tlyA deficient or mutation, is not fully understood. Herein, we utilized a multi-omics (genome, proteome, and metabolome) approach to assess CAP resistance on tlyA deficient CAPr Mtb strains (CAPr1) and tlyA point mutation CAPr Mtb strains (CAPr2) that we established for the first time in vitro to investigate the CAP-resistant mechanism. Our results showed that the CAPr1 strains (> 40 µg/ml) was more resistant to CAP than the CAPr2 strains (G695A, 10 µg/ml). Furthermore, multi-omics analysis indicated that the CAPr1 strains exhibited greater drug tolerance than the CAPr2 strains may be associated with the weakening of S-adenosyl-L-methionine-dependent methyltransferase (AdoMet-MT) activity and abnormal membrane lipid metabolism such as suppression of fatty acid metabolism, promotion of glycolipid phospholipid and glycerolipid metabolism. As a result, these studies reveal a new mechanism for CAP resistance to tlyA deficient or mutation Mtb strains, and may be helpful in developing new therapeutic approaches to prevent Mtb resistance to CAP.


Assuntos
Antituberculosos/farmacologia , Proteínas de Bactérias/genética , Capreomicina/farmacologia , Biologia Computacional , Farmacorresistência Bacteriana , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Genômica , Lipídeos de Membrana/metabolismo , Metabolômica , Metiltransferases/metabolismo , Testes de Sensibilidade Microbiana , Mutação , Mycobacterium tuberculosis/metabolismo , Proteômica
17.
Neuroradiology ; 61(9): 1073-1081, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31353425

RESUMO

PURPOSE: To investigate the imaging and clinical outcomes of emergent angioplasty and/or stenting or neither in patients of emergent large-vessel occlusion (ELVO) with underlying severe intracranial atherosclerotic stenosis (ICAS). METHODS: In this multicenter prospective cohort study, we included patients of ELVO with underlying ICAS. Patients received emergent angioplasty and/or stenting or neither after mechanical thrombectomy at the interventionists' discretion. The primary outcome was recanalization rate at 24 h, which was defined as a modified arterial occlusive lesion score of 2 or 3. RESULTS: A total of 113 consecutive patients with underlying ICAS > 70% in anterior cerebral circulation were enrolled in this study. Of these, 81 (71.7%) received emergent angioplasty and/or stenting after thrombectomy. Patients in the emergent angioplasty and/or stenting group were significantly more likely to have recanalization at 24 h (adjusted OR [aOR], 3.782; 95% confidence interval [CI], 1.821-9.125; P = 0.02) and less likely to have early neurologic deterioration (aOR, 0.299; 95% CI, 0.110-0.821; P = 0.01). However, emergent angioplasty and/or stenting was not significantly associated with symptomatic intracranial hemorrhage (aOR, 0.710; 95% CI, 0.199-2.622; P = 0.67), asymptomatic intracranial hemorrhage (aOR, 1.325; 95% CI, 0.567-3.031; P = 0.81), death at 90 days (aOR, 0.581; 95% CI, 0.186-2.314; P = 0.41), and functional independence at 90 days (aOR, 1.752; 95% CI, 0.774-3.257; P = 0.16), compared with patients that received neither. CONCLUSION: Emergent angioplasty and/or stenting is possible in patients of ELVO with ICAS and may reduce the risk of reocclusion and early neurologic deterioration with no increased risk of intracranial hemorrhage and death than those received neither.


Assuntos
Angioplastia , Arteriosclerose Intracraniana/cirurgia , Trombose Intracraniana/cirurgia , Stents , Trombectomia , Idoso , Estudos de Coortes , Feminino , Humanos , Arteriosclerose Intracraniana/complicações , Arteriosclerose Intracraniana/diagnóstico por imagem , Trombose Intracraniana/complicações , Trombose Intracraniana/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Tomografia Computadorizada por Raios X , Resultado do Tratamento
18.
J Am Pharm Assoc (2003) ; 58(5): 481-484, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30007508

RESUMO

OBJECTIVES: The objective of this position statement is to describe the essential role of pharmacists in antimicrobial stewardship in outpatient care. DATA SOURCES: N/A. SUMMARY: The majority of antibiotic prescribing occurs in outpatient care settings highlighting the need for antibiotic stewardship in the community. Given their expertise on medication management, pharmacists are essential to any antibiotic stewardship effort. CONCLUSION: As the regulations for antibiotic stewardship in outpatient settings continue to evolve and optimal stewardship strategies are defined, pharmacists must be leaders in the implementation of these programs.


Assuntos
Assistência Ambulatorial/organização & administração , Antibacterianos/uso terapêutico , Gestão de Antimicrobianos/organização & administração , Doenças Transmissíveis/tratamento farmacológico , Farmacêuticos/organização & administração , Humanos , Pacientes Ambulatoriais
19.
Nano Lett ; 17(1): 71-77, 2017 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-27958757

RESUMO

Neural probes based on graphene field-effect transistors have been demonstrated. Yet, the minimum detectable signal of graphene transistor-based probes is inversely proportional to the square root of the active graphene area. This fundamentally limits the scaling of graphene transistor-based neural probes for improved spatial resolution in brain activity recording. Here, we address this challenge using highly crumpled all-carbon transistors formed by compressing down to 16% of its initial area. All-carbon transistors, chemically synthesized by seamless integration of graphene channels and hybrid graphene/carbon nanotube electrodes, maintained structural integrity and stable electronic properties under large mechanical deformation, whereas stress-induced cracking and junction failure occurred in conventional graphene/metal transistors. Flexible, highly crumpled all-carbon transistors were further verified for in vivo recording of brain activity in rats. These results highlight the importance of advanced material and device design concepts to make improvements in neuroelectronics.


Assuntos
Encéfalo/diagnóstico por imagem , Desenho de Equipamento/métodos , Grafite/química , Nanotubos de Carbono/química , Transistores Eletrônicos , Animais , Encéfalo/fisiologia , Simulação por Computador , Eletrodos , Microscopia Confocal , Nanotecnologia , Tamanho da Partícula , Ratos , Propriedades de Superfície
20.
J Phys Chem A ; 121(38): 7236-7245, 2017 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-28853572

RESUMO

Criegee intermediates (CIs) play a key role in controlling the atmospheric budget of hydroxyl radical, organic acids, and secondary organic aerosols. In this study, the detailed reaction mechanisms of the simplest Criegee intermediate CH2OO and its derivatives with methane (CH4) have been systematically investigated theoretically. Two pathways A and B have been identified for the title reaction. In pathway A, CIs can act as an oxygen donor by inserting its terminal oxygen atom into the C-H bond of alkanes, resulting in the formation of alcohol species. The corresponding energy barriers ranging from 6.5 to 24.1 kcal/mol are associated with the O-O bond strength of CIs. Meanwhile, this pathway is more favorable thermodynamically, where the free energy changes (enthalpy changes) range from -81.1 (-78.3) to -110.9 (-109.0) kcal/mol, respectively. In pathway B, an addition reaction to produce the hydroperoxides occurs, accompanying the hydrogen transfer from the alkanes to the terminal oxygen atom of CIs. The corresponding energy barriers ranging from 17.3 to 30.9 kcal/mol are higher than those in pathway A. Further calculations of the rate constants suggest that pathway A is the most favorable reaction channel and the rate constant exhibits a positive temperature dependence. In addition, the conformation-dependent reactivity for the title reaction has been observed. The present findings can enable us to better understand the potential reactivity of CIs in the presence of the alkane species.

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