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1.
Zhongguo Zhong Yao Za Zhi ; 49(14): 3857-3867, 2024 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-39099359

RESUMO

The study investigated the protective effect and mechanism of 2-phenylethyl-beta-glucopyranoside(Phe) from Huaizhong No.1 Rehmannia glutinosa on hypoxic pulmonary hypertension(PH), aiming to provide a theoretical basis for clinical treatment of PAH. Male C57BL/6N mice were randomly divided into normal group, model group, positive drug(bosentan, 100 mg·kg~(-1)) group, and low-and high-dose Phe groups(20 and 40 mg·kg~(-1)). Except for the normal group, all other groups were continuously subjected to model induction in a 10% hypoxic environment for 5 weeks, with oral administration for 14 days starting from the 3rd week. The cardiopulmonary function, right ventricular pressure, cough and asthma index, lung injury, cell apoptosis, oxidative stress-related indicators, immune cells, and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)/mammalian target of rapamycin(mTOR)/hypoxic inducible factor 1α(HIF-1α) pathway-related proteins or mRNA levels were examined. Furthermore, hypoxia-induced pulmonary arterial smooth muscle cell(PASMC) were used to further explore the mechanism of Phe intervention in PH combined with PI3K ago-nist(740Y-P). The results showed that Phe significantly improved the cardiopulmonary function of mice with PH, decreased right ventricular pressure, cough and asthma index, and lung injury, reduced cell apoptosis, oxidative stress-related indicators, and nuclear levels of phosphorylated Akt(p-Akt) and phosphorylated mTOR(p-mTOR), inhibited the expression levels of HIF-1α and PI3K mRNA and proteins, and maintained the immune cell homeostasis in mice. Further mechanistic studies revealed that Phe significantly reduced the viability and migration ability of hypoxia-induced PASMC, decreased the expression of HIF-1α and PI3K proteins and nuc-lear levels of p-Akt and p-mTOR, and this effect was blocked by 740Y-P. Therefore, it is inferred that Phe may exert anti-PH effects by alleviating the imbalance of oxidative stress and apoptosis in lung tissues and regulating immune levels, and its mechanism may be related to the regulation of the PI3K/Akt/mTOR/HIF-1α pathway. This study is expected to provide drug references and research ideas for the treatment of PH.


Assuntos
Glucosídeos , Hipertensão Pulmonar , Subunidade alfa do Fator 1 Induzível por Hipóxia , Hipóxia , Camundongos Endogâmicos C57BL , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Rehmannia , Serina-Treonina Quinases TOR , Animais , Masculino , Serina-Treonina Quinases TOR/metabolismo , Serina-Treonina Quinases TOR/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Camundongos , Hipertensão Pulmonar/tratamento farmacológico , Hipertensão Pulmonar/fisiopatologia , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Rehmannia/química , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositol 3-Quinases/genética , Glucosídeos/farmacologia , Hipóxia/tratamento farmacológico , Hipóxia/fisiopatologia , Hipóxia/metabolismo , Transdução de Sinais/efeitos dos fármacos , Humanos , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/química , Apoptose/efeitos dos fármacos
2.
World J Clin Cases ; 12(7): 1272-1283, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38524507

RESUMO

BACKGROUND: Remimazolam is characterized by rapid action and inactive metabolites. It is used as the general anesthetic for many clinical surgeries. In this study, we performed a meta-analysis to evaluate whether remimazolam is superior to propofol for gastroenteroscopy in older patients. AIM: To compare the adverse events and efficacy of remimazolam and propofol during gastroenteroscopy in older adults. METHODS: The PubMed, Web of Science, the Cochrane Library databases were queried for the relevant key words "remimazolam," "and propofol," "and gastrointestinal endoscopy or gastroscopy." The search scope was "Title and Abstract," and the search was limited to human studies and publications in English. Seven studies wherein remimazolam and propofol were compared were included for the meta-analysis. RESULTS: We selected seven randomized controlled trials involving 1445 cases for the analysis. Remimazolam reduced the hypotension (relative risk, RR = 0.44, 95%CI: 0.29-0.66, P = 0.000), respiratory depression (RR = 0.46, 95%CI: 0.30-0.70, P = 0.000), injection pain (RR = 0.12, 95%CI: 0.05-0.25, P = 0.000), bradycardia (RR = 0.37, 95%CI: 0.24-0.58, P = 0.000), and time to discharge [weighted mean difference (WMD) = -0.58, 95%CI: -0.97 to -0.18, P = 0.005], compared to those after propofol administration. No obvious differences were observed for postoperative nausea and vomiting (RR = 1.09, 95%CI: 0.97-1.24, P = 0.151), dizziness (RR = 0.77, 95%CI: 0.43-1.36, P = 0.361), successful sedation rate (RR = 0.96, 95%CI: 0.93-1.00, P = 0.083), or the time to become fully alert (WMD = 0.00, 95%CI: -1.08-1.08, P = 0.998). CONCLUSION: Remimazolam appears to be safer than propofol for gastroenteroscopy in older adults. However, further studies are required to confirm these findings.

3.
Commun Med (Lond) ; 3(1): 65, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37165172

RESUMO

BACKGROUND: Accurate prediction of cerebral amyloidosis with easily available indicators is urgently needed for diagnosis and treatment of Alzheimer's disease (AD). METHODS: We examined plasma Aß42, Aß40, T-tau, P-tau181, and NfL, with APOE genotypes, cognitive test scores and key demographics in a large Chinese cohort (N = 609, aged 40 to 84 years) covering full AD spectrum. Data-driven integrated computational models were developed to predict brain ß-amyloid (Aß) pathology. RESULTS: Our computational models accurately predict brain Aß positivity (area under the ROC curves (AUC) = 0.94). The results are validated in Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort. Particularly, the models have the highest prediction power (AUC = 0.97) in mild cognitive impairment (MCI) participants. Three levels of models are designed with different accuracies and complexities. The model which only consists of plasma biomarkers can predict Aß positivity in amnestic MCI (aMCI) patients with AUC = 0.89. Generally the models perform better in participants without comorbidities or family histories. CONCLUSIONS: The innovative integrated models provide opportunity to assess Aß pathology in a non-invasive and cost-effective way, which might facilitate AD-drug development, early screening, clinical diagnosis and prognosis evaluation.


The numbers of people with Alzheimer's disease are increasing. People with Alzheimer's disease have changes in the brain as well as cognitive impairment, which is when a person has difficulty remembering, learning, concentrating, or making decisions. Innovative medicines and new treatments all target people with early Alzheimer's disease. However, the methods used currently to diagnose Alzheimer's disease are expensive and can be unpleasant for patients. We studied Chinese people with no cognitive impairment, some cognitive decline, mild cognitive impairment, Alzheimer's disease and non-Alzheimer's disease dementia. We established a computational model that can predict the changes seen in the brain in people with Alzheimer's disease from information including results of blood and memory tests. This non-invasive and cost-effective approach might improve early identification of those with Alzheimer's disease.

4.
Interdiscip Sci ; 14(2): 607-622, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35428965

RESUMO

Emerging evidence indicates that miRNAs have strong relationships with many human diseases. Investigating the associations will contribute to elucidating the activities of miRNAs and pathogenesis mechanisms, and providing new opportunities for disease diagnosis and drug discovery. Therefore, it is of significance to identify potential associations between miRNAs and diseases. The existing databases about the miRNA-disease associations (MDAs) only provide the known MDAs, which can be regarded as positive samples. However, the unknown MDAs are not sufficient to regard as reliable negative samples. To deal with this uncertainty, we proposed a convolutional neural network (CNN) framework, named DNRLCNN, based on a latent feature matrix extracted by only positive samples to predict MDAs. First, by only considering the positive samples into the calculation process, we captured the latent feature matrix for complex interactions between miRNAs and diseases in low-dimensional space. Then, we constructed a feature vector for each miRNA and disease pair based on the feature representation. Finally, we adopted a modified CNN for the feature vector to predict MDAs. As a result, our model achieves better performance than other state-of-the-art methods which based CNN in fivefold cross-validation on both miRNA-disease association prediction task (average AUC of 0.9030) and miRNA-phenotype association prediction task (average AUC of 0. 9442). In addition, we carried out case studies on two human diseases, and all the top-50 predicted miRNAs for lung neoplasms are confirmed by HMDD v3.2 and dbDEMC 2.0 databases, 98% of the top-50 predicted miRNAs for heart failure are confirmed. The experiment results show that our model has the capability of inferring potential disease-related miRNAs.


Assuntos
MicroRNAs , Algoritmos , Biologia Computacional/métodos , Predisposição Genética para Doença , Humanos , MicroRNAs/genética , Redes Neurais de Computação
5.
Brain Plast ; 7(2): 97-109, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34868876

RESUMO

BACKGROUND: Cognitive impairment is common among adolescent and young adult (AYA) cancer survivors. Physical activity (PA) may help mitigate cognitive impairment post-treatment by positively impacting two indicators of general brain health: fractional anisotropy (FA) and functional connectivity (FC). As part of a two-arm, mixed-methods pilot randomized controlled trial (RCT), this sub-study was designed to provide preliminary proof-of-concept evidence for the effects of PA on FA and FC among AYA cancer survivors post-treatment to help inform decisions about proceeding to larger trials. METHODS: AYA cancer survivors who had completed cancer treatment and who were enrolled in a larger pilot RCT comparing a 12-week PA intervention to a waitlist control group, were invited to participate in this sub-study. Sub-study participants completed diffusion tensor imaging and resting-state functional magnetic resonance imaging prior to randomization and post-intervention. Data were analyzed with descriptive statistics, independent component analysis, and paired sample t-tests. RESULTS: Post-intervention, participants showed increases in FA of the bilateral hippocampal cingulum, left anterior corona radiata, middle cingulum, left anterior thalamic radiation, and left cerebellum. A decrease in overall FC of the default mode network and increases in the cerebellar and visual networks were also noted post-intervention (p < .05). CONCLUSION: Results provide preliminary evidence for the possible positive effects of PA on FA and FC among AYA cancer survivors post-treatment. On the basis of these results, larger trials assessing the effects of PA on specific brain health indicators, as captured by FA and FC, among AYA cancer survivors are appropriate and warranted.

6.
Cell Immunol ; 369: 104426, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34469846

RESUMO

Myeloid-derived suppressor cells (MDSC) are induced during active TB disease to restore immune homeostasis but instead exacerbate disease outcome due to chronic inflammation. Autophagy, in conventional phagocytes, ensures successful clearance of M.tb. However, autophagy has been demonstrated to induce prolonged MDSC survival. Here we investigate the relationship between autophagy mediators and MDSC in the context of active TB disease and during anti-TB therapy. We demonstrate a significant increase in MDSC frequencies in untreated active TB cases with these MDSC expressing TLR4 and significantly more mTOR and IL-6 than healthy controls, with mTOR levels decreasing during anti-TB therapy. Finally, we show that HMGB1 serum concentrations decrease in parallel with mTOR. These findings suggest a complex interplay between MDSC and autophagic mediators, potentially dependent on cellular localisation and M.tb infection state.


Assuntos
Autofagia/imunologia , Células Supressoras Mieloides/imunologia , Tuberculose/imunologia , Antituberculosos/uso terapêutico , Autofagia/efeitos dos fármacos , Proteína HMGB1/imunologia , Proteína HMGB1/metabolismo , Humanos , Interleucina-6/imunologia , Interleucina-6/metabolismo , Células Supressoras Mieloides/efeitos dos fármacos , Células Supressoras Mieloides/metabolismo , Serina-Treonina Quinases TOR/imunologia , Serina-Treonina Quinases TOR/metabolismo , Tuberculose/tratamento farmacológico , Tuberculose/metabolismo
7.
Cogn Affect Behav Neurosci ; 21(5): 1026-1038, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33982247

RESUMO

Emotion processing is known to interact with memory. Ovarian steroid hormones, such as progesterone and estradiol, modulate emotion processing and memory. However, it is unclear how these hormones influence brain activity when emotion processing is integrated with working memory (WM). Therefore, the objective of this study was to examine the relationship between endogenous hormonal concentration and brain activity during emotion processing in the context of a WM n-back task in 74 young women using functional magnetic resonance imaging (fMRI). Results show that positive emotion processing activates reward-related areas, such as the caudate and putamen, whereas negative emotion processing activates a corticolimbic network, including the amygdala and hippocampus. Furthermore, our findings provide evidence that progesterone modulates more bottom-up brain activation during both positive and negative emotion processing, whereas estradiol activates lateralized, top-down regulation. These findings provide insight on the neural correlates of emotion processing during an n-back task in young women and highlight how important it is to consider women's endogenous hormonal concentration in neurobiological and cognition research.


Assuntos
Estradiol , Progesterona , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Emoções , Feminino , Humanos , Imageamento por Ressonância Magnética , Memória de Curto Prazo
8.
J Cancer Surviv ; 14(6): 915-922, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32557211

RESUMO

PURPOSE: The present study explores the benefits of an 8-week mindfulness-based stress reduction (MBSR) program to white matter integrity among breast cancer survivors experiencing chronic neuropathic pain (CNP). METHODS: Twenty-three women were randomly assigned to either a MBSR treatment group (n = 13) or a waitlist control group (n = 10). Participants were imaged with MRI prior to and post-MBSR training using diffusion tensor imaging. RESULTS: Compared with controls, the MBSR group showed a significant increase in fractional anisotropy (FA), particularly in the left subcortical regions including the uncinate fasciculus, amygdala, and hippocampus, as well as in the external capsule and in the left sagittal stratum. No decreases to FA were found in any brain regions following MBSR training. The FA values also negatively correlated with the pain severity and pain interference scores from the BRIEF pain questionnaire. CONCLUSIONS: The present findings demonstrate that MBSR training may enhance the integrity of cerebral white matter that coincides with a reduction in pain perception. Further research with a larger sample size is required. IMPLICATIONS FOR CANCER SURVIVORS: This study highlights the potential for MBSR, as a non-pharmacological intervention, to provide both brain health improvement and pain perception relief for female breast cancer survivors experiencing CNP.


Assuntos
Encéfalo/fisiologia , Neoplasias da Mama/complicações , Sobreviventes de Câncer/psicologia , Dor Crônica/terapia , Atenção Plena/métodos , Neuralgia/terapia , Estresse Psicológico/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Dor do Câncer/diagnóstico por imagem , Dor do Câncer/etiologia , Dor do Câncer/terapia , Dor Crônica/diagnóstico por imagem , Dor Crônica/etiologia , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Neuralgia/diagnóstico por imagem , Neuralgia/etiologia , Inquéritos e Questionários
9.
Drug Alcohol Depend ; 182: 78-85, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29172122

RESUMO

INTRODUCTION: Research indicates that overnight nicotine abstinence disrupts neural activity in the mesocorticolimbic reward network; however, less is known about the time course of abstinence-induced brain changes. To examine the potential neural effects of early abstinence, we used arterial spin labeling perfusion fMRI, to measure regional cerebral blood flow (rCBF) changes in the resting brain induced by 4h of nicotine abstinence. METHODS: In a repeated measures design, 5min of resting perfusion fMRI data were acquired in awake nicotine-dependent individuals (eyes open) during 'smoking as usual' (SMK) and following 4h of monitored nicotine abstinence (ABS) conditions (N=20). Conditions were compared using a paired t test in SPM8. Craving was assessed prior to each condition. RESULTS: Compared to SMK, ABS significantly increased craving and reduced rCBF in select regions, including the hippocampus and ventral striatum (cluster corr, α=0.01, 943 contiguous voxels). The magnitude of the abstinence-induced change in rCBF correlated with the magnitude of the change in craving across conditions in select regions, including the medial and lateral orbitofrontal cortices and the anterior ventral insula (r values ranging from 0.59-0.74). CONCLUSIONS: Results show that as few as 4h of abstinence can reduce resting rCBF in multiple nodes of the brain's mesocorticolimbic network, disrupting neural processing. Identifying early withdrawal treatment targets has far-reaching implications, which include thwarting relapse proclivities. Results parallel those of the extant human literature and are in agreement with an extensive preclinical literature showing compromised mesolimbic dopaminergic function and impairments in reward function during nicotine withdrawal.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Fumar Cigarros/metabolismo , Fissura/fisiologia , Imageamento por Ressonância Magnética/métodos , Adulto , Mapeamento Encefálico/métodos , Circulação Cerebrovascular/fisiologia , Fumar Cigarros/terapia , Feminino , Humanos , Masculino , Descanso/fisiologia , Abandono do Hábito de Fumar/métodos , Fatores de Tempo , Tabagismo/diagnóstico por imagem , Tabagismo/metabolismo , Tabagismo/terapia
10.
BMC Res Notes ; 10(1): 426, 2017 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-28841831

RESUMO

BACKGROUND: The ESX secretion system, also known as the Type VII secretion system, is mostly found in mycobacteria and plays important roles in nutrient acquisition and host pathogenicity. One of the five ESXs, ESX-3, is associated with mycobactin-mediated iron acquisition. Although the functions of some of the membrane-associated components of the ESX systems have been described, the role of by mycosin-3 remains elusive. The esx-3 gene cluster encoding ESX-3 in both Mycobacterium tuberculosis and Mycobacterium smegmatis has two promoters, suggesting the presence of two transcriptional units. Previous studies indicated that the two promoters only showed a difference in response under acid stress (pH 4.2). This study aimed to study the effect of a mycosin-3 deletion on the physiology of M. smegmatis and to assess the promoter activities in wildtype, mycosin-3 mutant and complementation strains. RESULTS: The gene mycP 3 was deleted from wildtype M. smegmatis via homologous recombination. The mycP 3 gene was complemented in the deletion mutant using each of the two intrinsic promoters from the M. smegmatis esx-3 gene cluster. The four strains were compared in term of bacterial growth and intracellular iron content. The two promoter activities were assessed under iron-rich, iron-deprived and iron-rescued conditions by assessing the mycP 3 expression level. Although the mycP 3 gene deletion did not significantly impact bacterial growth or intracellular iron levels in comparison to the wild-type and complemented strains, the two esx-3 promoters were shown to respond inversely to iron deprivation and iron rescue. CONCLUSION: This finding correlates with the previously published data that the first promoter upstream of msmeg0615, is upregulated under low iron levels but downregulated under high iron levels. In addition, the second promoter, upstream of msmeg0620, behaves in an inverse fashion to the first promoter implying that the genes downstream may have additional roles when the iron levels are high.


Assuntos
Sistemas de Secreção Bacterianos/metabolismo , Regulação Bacteriana da Expressão Gênica , Ferro/metabolismo , Família Multigênica , Mycobacterium smegmatis/metabolismo , Regiões Promotoras Genéticas
11.
Sci Rep ; 6: 29435, 2016 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-27377552

RESUMO

Cigarette smoking is a chronic relapsing brain disorder, and remains a premier cause of morbidity and mortality. Functional neuroimaging has been used to assess differences in the mean strength of brain activity in smokers' brains, however less is known about the temporal dynamics within smokers' brains. Temporal dynamics is a key feature of a dynamic system such as the brain, and may carry information critical to understanding the brain mechanisms underlying cigarette smoking. We measured the temporal dynamics of brain activity using brain entropy (BEN) mapping and compared BEN between chronic non-deprived smokers and non-smoking controls. Because of the known sex differences in neural and behavioral smoking characteristics, comparisons were also made between males and females. Associations between BEN and smoking related clinical measures were assessed in smokers. Our data showed globally higher BEN in chronic smokers compared to controls. The escalated BEN was associated with more years of smoking in the right limbic area and frontal region. Female nonsmokers showed higher BEN than male nonsmokers in prefrontal cortex, insula, and precuneus, but the BEN sex difference in smokers was less pronounced. These findings suggest that BEN mapping may provide a useful tool for probing brain mechanisms related to smoking.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/fisiopatologia , Tabagismo/diagnóstico por imagem , Adulto , Estudos de Casos e Controles , Estudos Transversais , Entropia , Feminino , Lobo Frontal/fisiologia , Lobo Frontal/fisiopatologia , Humanos , Lobo Límbico/fisiopatologia , Masculino , Pessoa de Meia-Idade , Caracteres Sexuais , Fumantes , Tabagismo/fisiopatologia , Adulto Jovem
12.
Drug Alcohol Depend ; 153: 116-23, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26094186

RESUMO

BACKGROUND: Resting-state functional connectivity is a noninvasive, neuroimaging method for assessing neural network function. Altered functional connectivity among regions of the default-mode network have been associated with both nicotine and cannabis use; however, less is known about co-occurring cannabis and tobacco use. METHODS: We used posterior cingulate cortex (PCC) seed-based resting-state functional connectivity analyses to examine default mode network (DMN) connectivity strength differences between four groups: (1) individuals diagnosed with cannabis dependence who do not smoke tobacco (n=19; ages 20-50), (2) cannabis-dependent individuals who smoke tobacco (n=23, ages 21-52), (3) cannabis-naïve, nicotine-dependent individuals who smoke tobacco (n=24, ages 21-57), and (4) cannabis- and tobacco-naïve healthy controls (n=21, ages 21-50), controlling for age, sex, and alcohol use. We also explored associations between connectivity strength and measures of cannabis and tobacco use. RESULTS: PCC seed-based analyses identified the core nodes of the DMN (i.e., PCC, medial prefrontal cortex, inferior parietal cortex, and temporal cortex). In general, the cannabis-dependent, nicotine-dependent, and co-occurring use groups showed lower DMN connectivity strengths than controls, with unique group differences in connectivity strength between the PCC and the cerebellum, medial prefrontal cortex, parahippocampus, and anterior insula. In cannabis-dependent individuals, PCC-right anterior insula connectivity strength correlated with duration of cannabis use. CONCLUSIONS: This study extends previous research that independently examined the differences in resting-state functional connectivity among individuals who smoke cannabis and tobacco by including an examination of co-occurring cannabis and tobacco use and provides further evidence that cannabis and tobacco exposure is associated with alterations in DMN connectivity.


Assuntos
Encéfalo/fisiopatologia , Giro do Cíngulo/fisiopatologia , Fumar Maconha/fisiopatologia , Vias Neurais/fisiopatologia , Fumar/fisiopatologia , Tabagismo/fisiopatologia , Adulto , Feminino , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Adulto Jovem
13.
Tuberculosis (Edinb) ; 95(2): 123-30, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25636179

RESUMO

Iron is an essential element to most life forms including mycobacterial species. However, in the oxidative atmosphere iron exists as insoluble salts. Free and soluble iron ions are scarce in both the extracellular and intracellular environment which makes iron assimilation very challenging to mycobacteria. Tuberculosis, caused by the pathogen, Mycobacterium tuberculosis, is one of the most infectious and deadly diseases in the world. Extensive studies regarding iron acquisition strategies have been documented in mycobacteria, including work on the mycobacterial iron chelators (siderophores), the iron-responsive regulon, and iron transport and utilization pathways. Under low iron conditions, expression of the genes encoding iron importers, exporters and siderophore biosynthetic enzymes is up-regulated significantly increasing the ability of the bacteria to acquire limited host iron. Disabling these proteins impairs the growth of mycobacteria under low iron conditions both in vitro and in vivo, and that of pathogenic mycobacteria in animal models. Drugs targeting siderophore-mediated iron transport could offer promising therapeutic options. However, the discovery and characterization of an alternative iron acquisition mechanism, the heme transport and utilization pathway, questions the effectiveness of the siderophore-centered therapeutic strategy. Links have been found between these two distinct iron acquisition mechanisms, thus, targeting a few candidate proteins or mechanisms may influence both pathways, leading to effective elimination of the bacteria in the host.


Assuntos
Ferro/metabolismo , Mycobacterium/metabolismo , Proteínas de Bactérias/fisiologia , Transporte Biológico/fisiologia , Regulação Bacteriana da Expressão Gênica/fisiologia , Heme/metabolismo , Humanos , Mycobacterium tuberculosis/metabolismo , Via Secretória/fisiologia , Sideróforos/fisiologia
14.
Eur J Immunol ; 45(4): 1192-205, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25486906

RESUMO

Repeatedly activated T helper 1 (Th1) cells present during chronic inflammation can efficiently adapt to the inflammatory milieu, for example, by expressing the transcription factor Twist1, which limits the immunopathology caused by Th1 cells. Here, we show that in repeatedly activated murine Th1 cells, Twist1 and T-bet induce expression of microRNA-148a (miR-148a). miR-148a regulates expression of the proapoptotic gene Bim, resulting in a decreased Bim/Bcl2 ratio. Inhibition of miR-148a by antagomirs in repeatedly activated Th1 cells increases the expression of Bim, leading to enhanced apoptosis. Knockdown of Bim expression by siRNA in miR-148a antagomir-treated cells restores viability of the Th1 cells, demonstrating that miR-148a controls survival by regulating Bim expression. Thus, Twist1 and T-bet not only control the differentiation and function of Th1 cells, but also their persistence in chronic inflammation.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Apoptose/genética , Regulação da Expressão Gênica , Proteínas de Membrana/genética , MicroRNAs/fisiologia , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas com Domínio T/fisiologia , Células Th1/imunologia , Proteína 1 Relacionada a Twist/metabolismo , Animais , Artrite Reumatoide/imunologia , Proteína 11 Semelhante a Bcl-2 , Sobrevivência Celular/imunologia , Células Cultivadas , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Proteínas Nucleares/genética , Interferência de RNA , RNA Interferente Pequeno , Proteínas com Domínio T/genética , Proteína 1 Relacionada a Twist/genética
15.
Proc Natl Acad Sci U S A ; 111(25): 9229-34, 2014 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-24927527

RESUMO

In the bone marrow, a population of memory T cells has been described that promotes efficient secondary immune responses and has been considered to be preactivated, owing to its expression of CD69 and CD25. Here we show that human bone marrow professional memory T cells are not activated but are resting in terms of proliferation, transcription, and mobility. They are in the G0 phase of the cell cycle, and their transcriptome is that of resting T cells. The repertoire of CD4(+) bone marrow memory T cells compared with CD4(+) memory T cells from the blood is significantly enriched for T cells specific for cytomegalovirus-pp65 (immunodominant protein), tetanus toxoid, measles, mumps, and rubella. It is not enriched for vaccinia virus and Candida albicans-MP65 (immunodominant protein), typical pathogens of skin and/or mucosa. CD4(+) memory T cells specific for measles are maintained nearly exclusively in the bone marrow. Thus, CD4(+) memory T cells from the bone marrow provide long-term memory for systemic pathogens.


Assuntos
Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Células da Medula Óssea/imunologia , Linfócitos T CD4-Positivos/imunologia , Memória Imunológica/fisiologia , Subunidade alfa de Receptor de Interleucina-2/imunologia , Lectinas Tipo C/imunologia , Fase de Repouso do Ciclo Celular/imunologia , Adulto , Células da Medula Óssea/citologia , Linfócitos T CD4-Positivos/citologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
J Environ Sci (China) ; 21(12): 1710-5, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20131602

RESUMO

With the increasing use of synthetic pyrethroids (SPs), the significance of ecological safety and health risk is an emerging concern. In this study, we evaluated the chronic aquatic toxicity of cis-bifenthrin (cis-BF) in Daphnia magna and its cytotoxicity in Chinese hamster ovary (CHO) cells as well as human cervical carcinoma (Hela) cells. Chronic aquatic toxicity tests showed that cis-BF could significantly affect the reproduction of D. magna. The lowest observed effective concentration and the non-observed effective concentration of cis-BF to D. magna were 0.02 and 0.01 microg/L, respectively, and the chronic value was 0.014 microg/L. The intrinsic rate of natural increase was significantly decreased (p < 0.05) to 0.02 microg/L. The cytotoxicity assay demonstrated that cis-BF decreased cell viability in CHO and Hela cells in a concentration- and time-dependent manner. The IC50 values for Hela and CHO cells were 4.0 x 10(-5) and 3.2 x 10(-5) mol/L, respectively. Together, these results indicated that cis-BF induced chronic toxicity in both aquatic invertebrate animals and mammalian cells. These findings assist in understanding the impact of SPs on health and environmental safety. Considering the wide spectrum of SPs, a more comprehensive understanding of the negative effects is indispensible for planning future application and regulation of these pesticides.


Assuntos
Inseticidas/toxicidade , Piretrinas/toxicidade , Animais , Células CHO , Sobrevivência Celular , Cricetinae , Cricetulus , Daphnia , Células HeLa , Humanos , Testes de Toxicidade Crônica
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