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1.
Cell ; 184(14): 3731-3747.e21, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34214470

RESUMO

In motor neuroscience, state changes are hypothesized to time-lock neural assemblies coordinating complex movements, but evidence for this remains slender. We tested whether a discrete change from more autonomous to coherent spiking underlies skilled movement by imaging cerebellar Purkinje neuron complex spikes in mice making targeted forelimb-reaches. As mice learned the task, millimeter-scale spatiotemporally coherent spiking emerged ipsilateral to the reaching forelimb, and consistent neural synchronization became predictive of kinematic stereotypy. Before reach onset, spiking switched from more disordered to internally time-locked concerted spiking and silence. Optogenetic manipulations of cerebellar feedback to the inferior olive bi-directionally modulated neural synchronization and reaching direction. A simple model explained the reorganization of spiking during reaching as reflecting a discrete bifurcation in olivary network dynamics. These findings argue that to prepare learned movements, olivo-cerebellar circuits enter a self-regulated, synchronized state promoting motor coordination. State changes facilitating behavioral transitions may generalize across neural systems.


Assuntos
Movimento/fisiologia , Rede Nervosa/fisiologia , Potenciais de Ação/fisiologia , Animais , Cálcio/metabolismo , Cerebelo/fisiologia , Sincronização Cortical , Membro Anterior/fisiologia , Interneurônios/fisiologia , Aprendizagem , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Neurológicos , Atividade Motora/fisiologia , Núcleo Olivar/fisiologia , Optogenética , Células de Purkinje/fisiologia , Comportamento Estereotipado , Análise e Desempenho de Tarefas
2.
Nature ; 580(7801): 100-105, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32238928

RESUMO

How the brain processes information accurately despite stochastic neural activity is a longstanding question1. For instance, perception is fundamentally limited by the information that the brain can extract from the noisy dynamics of sensory neurons. Seminal experiments2,3 suggest that correlated noise in sensory cortical neural ensembles is what limits their coding accuracy4-6, although how correlated noise affects neural codes remains debated7-11. Recent theoretical work proposes that how a neural ensemble's sensory tuning properties relate statistically to its correlated noise patterns is a greater determinant of coding accuracy than is absolute noise strength12-14. However, without simultaneous recordings from thousands of cortical neurons with shared sensory inputs, it is unknown whether correlated noise limits coding fidelity. Here we present a 16-beam, two-photon microscope to monitor activity across the mouse primary visual cortex, along with analyses to quantify the information conveyed by large neural ensembles. We found that, in the visual cortex, correlated noise constrained signalling for ensembles with 800-1,300 neurons. Several noise components of the ensemble dynamics grew proportionally to the ensemble size and the encoded visual signals, revealing the predicted information-limiting correlations12-14. Notably, visual signals were perpendicular to the largest noise mode, which therefore did not limit coding fidelity. The information-limiting noise modes were approximately ten times smaller and concordant with mouse visual acuity15. Therefore, cortical design principles appear to enhance coding accuracy by restricting around 90% of noise fluctuations to modes that do not limit signalling fidelity, whereas much weaker correlated noise modes inherently bound sensory discrimination.


Assuntos
Células Receptoras Sensoriais/fisiologia , Acuidade Visual/fisiologia , Córtex Visual/citologia , Córtex Visual/fisiologia , Animais , Feminino , Masculino , Camundongos , Estimulação Luminosa , Processos Estocásticos
3.
BMC Infect Dis ; 24(1): 584, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38867165

RESUMO

BACKGROUND: Natural infection and vaccination against SARS-CoV-2 is associated with the development of immunity against the structural proteins of the virus. Specifically, the two most immunogenic are the S (spike) and N (nucleocapsid) proteins. Seroprevalence studies performed in university students provide information to estimate the number of infected patients (symptomatic or asymptomatic) and generate knowledge about the viral spread, vaccine efficacy, and epidemiological control. Which, the aim of this study was to evaluate IgG antibodies against the S and N proteins of SARS-CoV-2 at university students from Southern Mexico. METHODS: A total of 1418 serum samples were collected from eighteen work centers of the Autonomous University of Guerrero. Antibodies were detected by Indirect ELISA using as antigen peptides derived from the S and N proteins. RESULTS: We reported a total seroprevalence of 39.9% anti-S/N (positive to both antigens), 14.1% anti-S and 0.5% anti-N. The highest seroprevalence was reported in the work centers from Costa Grande, Acapulco and Centro. Seroprevalence was associated with age, COVID-19, contact with infected patients, and vaccination. CONCLUSION: University students could play an essential role in disseminating SARS-CoV-2. We reported a seroprevalence of 54.5% against the S and N proteins, which could be due to the high population rate and cultural resistance to safety measures against COVID-19 in the different regions of the state.


Assuntos
Anticorpos Antivirais , COVID-19 , Proteínas do Nucleocapsídeo de Coronavírus , Imunoglobulina G , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Estudantes , Humanos , México/epidemiologia , Masculino , Feminino , Estudos Transversais , Glicoproteína da Espícula de Coronavírus/imunologia , Imunoglobulina G/sangue , COVID-19/epidemiologia , COVID-19/imunologia , Adulto Jovem , Anticorpos Antivirais/sangue , SARS-CoV-2/imunologia , Estudos Soroepidemiológicos , Adulto , Universidades , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Adolescente , Fosfoproteínas/imunologia
4.
Genes Chromosomes Cancer ; 62(7): 392-404, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36695641

RESUMO

miR-122 has been considered both as tumor suppressor miRNA and oncomiR in breast tumor phenotypes. However, the role of miR-122 in triple-negative breast cancer (TNBC) is still unknown. In this study, the clinical value of miR-122 was used to describe the transcriptomic landscape of TNBC tumors obtained from The Cancer Genome Atlas database. Low expression levels of miR-122 were associated with poor overall survival (OS) of TNBC patients than those with higher expression levels of miR-122. We identified gene expression profiles in TNBC tumors expressed lower or higher miR-122. Gene coexpression networks analysis revealed gene modules and hub genes specific to TNBC tumors with low or high miR-122 levels. Gene ontology and KEGG pathways analysis revealed that gene modules in TNBC with gain of miR-122 were related to cell cycle and DNA repair, while in TNBC with loss of miR-122 were enriched in cell cycle, proliferation, apoptosis and activation of cell migration and invasion. The expression of hub genes distinguished TNBC tumors with gain or loss of miR-122 from normal breast tissues. Furthermore, high levels of hub genes were associated with better OS in TNBC patients. Interestingly, the gene coexpression network related to loss of miR-122 were enriched with target genes of miR-122, but this did not observed in those with gain of miR-122. Target genes of miR-122 are oncogenes mainly associated with cell differentiation-related processes. Finally, 75 genes were identified exclusively associated to loss of miR-122, which are also implicated in cell differentiation. In conclusion, miR-122 could act as tumor suppressor by controlling oncogenes in TNBC.


Assuntos
MicroRNAs , Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Transcriptoma , Linhagem Celular Tumoral , Proliferação de Células/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Regulação Neoplásica da Expressão Gênica
5.
Foot Ankle Surg ; 30(4): 275-284, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38388212

RESUMO

BACKGROUND: Main objective of this research is to know if there is a different survival rate between fixed bearing (FB) and mobile bearing (MB) total ankle replacement (TAR). We hypothesized that there are no differences between the survival rates of both implants. METHODS: A systematic search was performed in PubMed, Cochrane, EMBASE and ClinicalTrials.gov databases to identify published studies from August 2018 to September 2022 including results for FB and MB TAR survivorship. Inclusion criteria included 1) primary TAR in one or both feet in which implant could be identified , 2) a minimum of 20 procedures reported, 3) reported implant survivorship or calculable and 4) a minimum of 12 months follow-up for level 1-3 studies or 60 months for level 4 studies. RESULTS: 3902 ankles in 28 studies were included. 719 were FB and 3104 MB with an overall survivorship of 94% (95% CI [0.89; 0.97]) and 89% (95% CI [0.86; 0.92]) respectively. After subgroup analysis, we did not find differences among both groups (p =  0.429 ). Meta-regression analysis showed that longer follow-up was associated with lower survival rates in MB group (p = 0.000) while no other relationships were found with other factors (age, level of evidence or conflict of interests). CONCLUSIONS: No differences in survival rates between both groups were found. Age and other studied confounders were not found to be related with implant survivorship. However, longer follow-up was found to be related with lower survival rates. Studies with longer follow-up and higher level of evidence are needed to confirm results. LEVEL OF EVIDENCE: IV, systematic review of level I to IV studies.


Assuntos
Artroplastia de Substituição do Tornozelo , Prótese Articular , Falha de Prótese , Humanos , Artroplastia de Substituição do Tornozelo/instrumentação , Desenho de Prótese , Articulação do Tornozelo/cirurgia
6.
BMC Microbiol ; 23(1): 319, 2023 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-37898784

RESUMO

BACKGROUND: The nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an excellent immunogen that promotes the production of high-titer antibodies. N protein-derived peptides identified using a bioinformatics approach can potentially be used to develop a new generation of vaccines or diagnostic methods for detecting SARS-CoV-2 and its variants. However, further studies must demonstrate their capacity to be naturally processed by the immune system. OBJECTIVE: We aimed to examine the in vivo processing and recognition of in silico-identified peptides using the serum of immunized animals with the complete protein. METHODS: Recombinant N (Nrec) protein was subcutaneously administered to six Balb/c mice. Enzyme-linked immunosorbent assay (ELISA), western blotting, dot blotting, and immunoprecipitation were performed to evaluate the recognition of the complete protein and in silico-derived peptides. RESULTS: The serum of immunized mice recognized ~ 62.5 ng/µL of Nrec with high specificity to linear and conformational epitopes. Dot blot analysis showed that peptides Npep2 and Npep3 were the most reactive. CONCLUSION: Our data confirm the high immunogenicity of the SARS-CoV-2 N protein and provide evidence on the antigenicity of two peptides located in the N-arm/RNA-binding domain (Npep2) and oligomerization domain/C-tail (Npep3), considered the biologically active site of the N protein.


Assuntos
COVID-19 , Proteínas do Nucleocapsídeo , Animais , Camundongos , SARS-CoV-2 , COVID-19/prevenção & controle , Nucleocapsídeo , Peptídeos , Anticorpos Antivirais
7.
Chem Biodivers ; 20(6): e202300274, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37167583

RESUMO

The antifungal and insecticidal activities of 34 extracts from 27 plant species were evaluated against fungal phytopathogens of the genus Fusarium and Xyleborus Scolytine ambrosia beetles involved in Fusarium dieback (FD) and laurel wilt (LW) diseases. Sixteen extracts caused mycelial growth inhibition (MGI) above 23 % at 2 mg mL-1 against F. solani, those from S. nudum and M. argyrophylla exhibited the highest MGI (57 % and 49 %, respectively). Thirteen extracts displayed significant antifungal activity against F. kuroshium, those from C. nocturnum and M. argyrophylla exhibited the highest MGI (100 % and 54.9 %, respectively). Additionally, ten plants extracts caused mortality in at least one of the beetle species tested, mainly from Solanaceae species. In the most active species, 39 phenolics were identified that may have contributed to their biological effects. This study is one of the first to report the potential of plant-derived natural products against the causative agents of FD and LW.


Assuntos
Fusarium , Inseticidas , Persea , Animais , Inseticidas/farmacologia , Antifúngicos/farmacologia , Ambrosia , México , Doenças das Plantas/microbiologia , Florestas , Extratos Vegetais/farmacologia
8.
Int J Mol Sci ; 24(8)2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37108566

RESUMO

Since the early 1980s, Epstein-Barr virus (EBV) infection has been described as one of the main risk factors for developing multiple sclerosis (MS), and recently, new epidemiological evidence has reinforced this premise. EBV seroconversion precedes almost 99% of the new cases of MS and likely predates the first clinical symptoms. The molecular mechanisms of this association are complex and may involve different immunological routes, perhaps all running in parallel (i.e., molecular mimicry, the bystander damage theory, abnormal cytokine networks, and coinfection of EBV with retroviruses, among others). However, despite the large amount of evidence available on these topics, the ultimate role of EBV in the pathogenesis of MS is not fully understood. For instance, it is unclear why after EBV infection some individuals develop MS while others evolve to lymphoproliferative disorders or systemic autoimmune diseases. In this regard, recent studies suggest that the virus may exert epigenetic control over MS susceptibility genes by means of specific virulence factors. Such genetic manipulation has been described in virally-infected memory B cells from patients with MS and are thought to be the main source of autoreactive immune responses. Yet, the role of EBV infection in the natural history of MS and in the initiation of neurodegeneration is even less clear. In this narrative review, we will discuss the available evidence on these topics and the possibility of harnessing such immunological alterations to uncover predictive biomarkers for the onset of MS and perhaps facilitate prognostication of the clinical course.


Assuntos
Infecções por Vírus Epstein-Barr , Esclerose Múltipla , Humanos , Herpesvirus Humano 4/fisiologia , Esclerose Múltipla/patologia , Fatores de Risco , Mimetismo Molecular
9.
Nat Methods ; 16(11): 1119-1122, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31659327

RESUMO

Two-photon microscopy is a mainstay technique for imaging in scattering media and normally provides frame-acquisition rates of ~10-30 Hz. To track high-speed phenomena, we created a two-photon microscope with 400 illumination beams that collectively sample 95,000-211,000 µm2 areas at rates up to 1 kHz. Using this microscope, we visualized microcirculatory flow, fast venous constrictions and neuronal Ca2+ spiking with millisecond-scale timing resolution in the brains of awake mice.


Assuntos
Encéfalo/irrigação sanguínea , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Animais , Cálcio/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microcirculação , Vigília
10.
Cancer Control ; 29: 10732748221103331, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35608056

RESUMO

BACKGROUND: Cervical cancer (CC) is the fourth most common malignancy of the female genital tract. Human Papillomavirus (HPV) is the main cause of precancerous lesions and CC cases worldwide. OBJECTIVE: We assessed the prevalence and distribution of HPV types and their association with precancerous lesions and CC. METHODS: HPV genotypes were detected by 3 methods depending on the year of in which the sample was analyzed: MY09/11 RFLPs (1997 to 2010), GP5+/6+ primer systems (2005 to 2010) and INNO-LiPA HPV Genotyping Extra (2010 to 2019) in cervical samples (No-IL: 4445; LSIL: 2464; HSILs: 151 and CC: 253) from women from southern Mexico. RESULTS: The overall HPV prevalence was 54.17%, and hpv-16 was the most common genotype. In single infection, the high-risk HPV genotypes (group 1) were associated with squamous intraepitelial lesions (LSIL: HPV-39 (OR = 10.58, 95% CI 4.09-27.36, P < .001); HSIL: HPV-31 (OR = 14.76, 95% CI 6.56-33.20, P < .001); and CC: HPV-16 (OR = 25.01, 95% CI 18.83-33.21, P < .001). In multiple infections, the HPV genotypes (HPV-16 and HPV-18) were also associated with a high risk of lesions [LSIL: HPV-18 (OR = 3.45; 95% CI 1.36-8.91; P = .009); HSIL: HPV-18 (OR = 5.12; 95% CI 1.21-21.68; P = .026); and CC: HPV-16 (OR = 3.03; 95% CI 1.72-5.32; P < .001)] compared to single infection. In the analysis adjusted for age, giving birth, and cigarette smoking, a significant increase in the risk of LSIL, HSIL, and CC was maintained. CONCLUSIONS: This study provides current data on the prevalence and distribution of HPV genotypes in women from southern Mexico, which could serve as a valuable reference to guide nationwide CC screening programs and provide scientific evidence that could be useful for vaccine development efforts. Likewise, it was identified that infection with carcinogenic HPV genotypes is an independent risk factor for LSIL, HSIL, and CC.


Assuntos
Alphapapillomavirus , Infecções por Papillomavirus , Lesões Pré-Cancerosas , Lesões Intraepiteliais Escamosas , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Genótipo , Papillomavirus Humano 16/genética , Humanos , México/epidemiologia , Papillomaviridae/genética , Lesões Pré-Cancerosas/epidemiologia , Gravidez , Prevalência , Neoplasias do Colo do Útero/patologia , Displasia do Colo do Útero/epidemiologia , Displasia do Colo do Útero/patologia
11.
Int J Mol Sci ; 23(19)2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-36233175

RESUMO

Dystrophin Dp71 is the most abundant product of the Duchenne muscular dystrophy gene in the nervous system, and mutations impairing its function have been associated with the neurodevelopmental symptoms present in a third of DMD patients. Dp71 is required for the clustering of neurotransmitter receptors and the neuronal differentiation of cultured cells; nonetheless, its precise role in neuronal cells remains to be poorly understood. In this study, we analyzed the effect of two pathogenic DMD gene point mutations on the Dp71 function in neurons. We engineered C272Y and E299del mutations to express GFP-tagged Dp71 protein variants in N1E-115 and SH-SY5Y neuronal cells. Unexpectedly, the ectopic expression of Dp71 mutants resulted in protein aggregation, which may be mechanistically caused by the effect of the mutations on Dp71 structure, as predicted by protein modeling and molecular dynamics simulations. Interestingly, Dp71 mutant variants acquired a dominant negative function that, in turn, dramatically impaired the distribution of different Dp71 protein partners, including ß-dystroglycan, nuclear lamins A/C and B1, the high-mobility group (HMG)-containing protein (BRAF35) and the BRAF35-family-member inhibitor of BRAF35 (iBRAF). Further analysis of Dp71 mutants provided evidence showing a role for Dp71 in modulating both heterochromatin marker H3K9me2 organization and the neuronal genes' expression, via its interaction with iBRAF and BRAF5.


Assuntos
Distrofina , Neuroblastoma , Distroglicanas/genética , Distrofina/genética , Heterocromatina , Proteínas de Grupo de Alta Mobilidade/genética , Proteínas de Grupo de Alta Mobilidade/metabolismo , Humanos , Laminas/genética , Neurônios/metabolismo , Lâmina Nuclear/metabolismo , Mutação Puntual , Agregados Proteicos , Receptores de Neurotransmissores/genética
12.
BMC Cancer ; 21(1): 39, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413211

RESUMO

BACKGROUND: To improve the efficiency of early diagnosis systems for cervical cancer, the use of cellular and viral markers for identifying precancerous lesions with a greater probability to progress to cancer has been proposed. Several cellular proteins and markers of oxidative DNA damage have been suggested as possible biomarkers of cervical carcinogenesis; however, they have not been evaluated together. In this study, we analyzed the expression of the cellular markers p16INK4a, Ki-67, CyclinE1, TOP2A/MCM2, and telomerase, as well as the DNA oxidative damage markers ROS and 8-OHdG. The analyses were performed in liquid-based cervical cytology samples or biopsies with premalignant lesions or cervical cancer diagnosis, with the purpose of selecting a panel of biomarkers that allow the identification of precursor lesions with greater risk of progression to cervical cancer. METHODS: We analyzed 1485 liquid-based cytology samples, including 239 non-squamous intraepithelial lesions (NSIL), 901 low-grade squamous intraepithelial lesions (LSIL), 54 high-grade squamous intraepithelial lesions (HSIL), and 291 cervical cancers (CC). The biomarkers were analyzed by immunocytochemistry and Human Papilloma Virus (HPV) genotyping with the INNO-LiPA genotyping Extra kit. RESULTS: We found that all tested cellular biomarkers were overexpressed in samples with high risk-HPV infection, and the expression levels increased with the severity of the lesion. TOP2A/MCM2 was the best biomarker for discriminating between LSIL and HSIL, followed by p16INK4a and cyclinE1. Statistical analysis showed that TOP2A/MCM2 provided the largest explanation of HSIL and CC cases (93.8%), followed by p16INK4a (91%), cyclin E1 (91%), Ki-67 (89.3%), and telomerase (88.9%). CONCLUSIONS: We propose that the detection of TOP2A/MCM2, p16INK4a and cyclin E1 expression levels is useful as a panel of biomarkers that allow identification of cervical lesions with a higher risk for progression to CC with high sensitivity and precision; this can be done inexpensively, in a single and non-invasive liquid-based cytology sample.


Assuntos
Ciclina E/metabolismo , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Biópsia Líquida/métodos , Componente 2 do Complexo de Manutenção de Minicromossomo/metabolismo , Proteínas Oncogênicas/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Lesões Pré-Cancerosas/patologia , Neoplasias do Colo do Útero/patologia , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Citodiagnóstico/métodos , Progressão da Doença , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/virologia , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/cirurgia , Lesões Pré-Cancerosas/virologia , Prognóstico , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/cirurgia , Neoplasias do Colo do Útero/virologia , Displasia do Colo do Útero/metabolismo , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/cirurgia , Displasia do Colo do Útero/virologia
14.
Int J Mol Sci ; 22(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34298896

RESUMO

Long non-coding RNAs (lncRNAs) are single-stranded RNA biomolecules with a length of >200 nt, and they are currently considered to be master regulators of many pathological processes. Recent publications have shown that lncRNAs play important roles in the pathogenesis and progression of insulin resistance (IR) and glucose homeostasis by regulating inflammatory and lipogenic processes. lncRNAs regulate gene expression by binding to other non-coding RNAs, mRNAs, proteins, and DNA. In recent years, several mechanisms have been reported to explain the key roles of lncRNAs in the development of IR, including metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), imprinted maternal-ly expressed transcript (H19), maternally expressed gene 3 (MEG3), myocardial infarction-associated transcript (MIAT), and steroid receptor RNA activator (SRA), HOX transcript antisense RNA (HOTAIR), and downregulated Expression-Related Hexose/Glucose Transport Enhancer (DREH). LncRNAs participate in the regulation of lipid and carbohydrate metabolism, the inflammatory process, and oxidative stress through different pathways, such as cyclic adenosine monophosphate/protein kinase A (cAMP/PKA), phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT), polypyrimidine tract-binding protein 1/element-binding transcription factor 1c (PTBP1/SREBP-1c), AKT/nitric oxide synthase (eNOS), AKT/forkhead box O1 (FoxO1), and tumor necrosis factor-alpha (TNF-α)/c-Jun-N-terminal kinases (JNK). On the other hand, the mechanisms linked to the molecular, cellular, and biochemical actions of lncRNAs vary according to the tissue, biological species, and the severity of IR. Therefore, it is essential to elucidate the role of lncRNAs in the insulin signaling pathway and glucose and lipid metabolism. This review analyzes the function and molecular mechanisms of lncRNAs involved in the development of IR.


Assuntos
Resistência à Insulina/genética , RNA Longo não Codificante/genética , Animais , Glucose/genética , Humanos , Insulina/genética , Metabolismo dos Lipídeos/genética , Transdução de Sinais/genética
15.
Molecules ; 26(4)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557136

RESUMO

Substituted phenylacetic (1-3), phenylpropanoic (4-6), and benzylidenethiazolidine-2,4-dione (7-9) derivatives were designed according to a multitarget unified pharmacophore pattern that has shown robust antidiabetic activity. This bioactivity is due to the simultaneous polypharmacological stimulation of receptors PPARα, PPARγ, and GPR40 and the enzyme inhibition of aldose reductase (AR) and protein tyrosine phosphatase 1B (PTP-1B). The nine compounds share the same four pharmacophore elements: an acid moiety, an aromatic ring, a bulky hydrophobic group, and a flexible linker between the latter two elements. Addition and substitution reactions were performed to obtain molecules at moderated yields. In silico pharmacological consensus analysis (PHACA) was conducted to determine their possible modes of action, protein affinities, toxicological activities, and drug-like properties. The results were combined with in vivo assays to evaluate the ability of these compounds to decrease glucose levels in diabetic mice at a 100 mg/kg single dose. Compounds 6 (a phenylpropanoic acid derivative) and 9 (a benzylidenethiazolidine-2,4-dione derivative) ameliorated the hyperglycemic peak in a statically significant manner in a mouse model of type 2 diabetes. Finally, molecular dynamics simulations were executed on the top performing compounds to shed light on their mechanism of action. The simulations showed the flexible nature of the binding pocket of AR, and showed that both compounds remained bound during the simulation time, although not sharing the same binding mode. In conclusion, we designed nine acid bioisosteres with robust in vivo antihyperglycemic activity that were predicted to have favorable pharmacokinetic and toxicological profiles. Together, these findings provide evidence that supports the molecular design we employed, where the unified pharmacophores possess a strong antidiabetic action due to their multitarget activation.


Assuntos
Simulação por Computador , Desenho de Fármacos , Hipoglicemiantes/síntese química , Hipoglicemiantes/farmacologia , Simulação de Dinâmica Molecular , Técnicas de Química Sintética , Hipoglicemiantes/química , Terapia de Alvo Molecular , Conformação Proteica , Reprodutibilidade dos Testes
16.
Comput Sci Eng ; 23(1): 7-16, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35939280

RESUMO

The urgent search for drugs to combat SARS-CoV-2 has included the use of supercomputers. The use of general-purpose graphical processing units (GPUs), massive parallelism, and new software for high-performance computing (HPC) has allowed researchers to search the vast chemical space of potential drugs faster than ever before. We developed a new drug discovery pipeline using the Summit supercomputer at Oak Ridge National Laboratory to help pioneer this effort, with new platforms that incorporate GPU-accelerated simulation and allow for the virtual screening of billions of potential drug compounds in days compared to weeks or months for their ability to inhibit SARS-COV-2 proteins. This effort will accelerate the process of developing drugs to combat the current COVID-19 pandemic and other diseases.

17.
Gastrointest Endosc ; 91(1): 163-168, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31082393

RESUMO

BACKGROUND AND AIMS: The novel use of peroral endoscopic myotomy (POEM) in the treatment of Zenker's diverticulum (ZD) was recently described in case reports. The aim of this study is to report a multicenter experience with the POEM technique in the management of ZD. METHODS: This is a multicenter international retrospective study involving 10 centers. The Zenker's POEM technique was performed using principles of submucosal endoscopy. RESULTS: Seventy-five patients (73.3 ± 1.2 years, 33 women) were included with a mean Charleson comorbidity index of 4 ± .2. The mean size of ZD was 31.3 ± 1.6 mm (range, 10-89). The overall technical success rate was 97.3% (73/75). There were 2 technical failures because of the inability to locate the septum and failed tunnel creation. Adverse events occurred in 6.7% (5/75): 1 bleed (mild) conservatively managed and 4 perforations (1 severe, 3 moderate). The mean procedure time was 52.4 ± 2.9 minutes, and mean length of hospital stay was 1.8 ± .2 days. Clinical success was achieved in 92% (69/75) with a decrease in mean dysphagia score from 1.96 to .25 (P < .0001). The median length of follow-up was 291.5 days (interquartile range, 103.5-436). At the 12-month follow-up, 1 patient reported symptom recurrence. CONCLUSIONS: Endoscopic management of ZD using the POEM technique is novel and feasible with promising efficacy and safety results. Long-term follow-up is needed to ensure durability of response. In addition, comparative studies with other treatment modalities are warranted.


Assuntos
Esfíncter Esofágico Superior/cirurgia , Miotomia , Cirurgia Endoscópica por Orifício Natural , Divertículo de Zenker/cirurgia , Idoso , Feminino , Humanos , Tempo de Internação , Masculino , Duração da Cirurgia , Recidiva , Estudos Retrospectivos , Resultado do Tratamento
18.
Rev Panam Salud Publica ; 44: e45, 2020.
Artigo em Espanhol | MEDLINE | ID: mdl-32973898

RESUMO

OBJECTIVE: Describe the results of the Program for the Rational Use of Antimicrobials at Mexico's Juárez Hospital. METHODS: An observational, cross-sectional, retrospective, descriptive study was designed. For the consumption of antimicrobial agents, data from January 2013 to December 2018 were analyzed by calculating the defined daily dose (DDD). For the cost analysis, a traditional costing calculation was used. RESULTS: For the group of carbapenem agents, there was a sizeable reduction in the consumption of imipenem / cilastatin: the DDD declined from 2.3 in 2013 to 0.7 in 2018, a decrease of 70%. By contrast, for the other two agents, increases were observed. The consumption of meropenem increased by 2% (from 2.4 in 2013 to 2.5 in 2018); the consumption of ertapenem increased by 75% (from 1 in 2013 to 1.8 in 2018). The total expenditure on antimicrobial agents was USD 930 556.46 during 2013, compared to USD 856 079.10 during 2018, representing a difference of 8% or USD 74 905.61 of the total expenditure. CONCLUSIONS: Programs for the rational use of antimicrobials need to be evaluated continuously, by monitoring both consumption of agents by patients and related institutional expenditures.


OBJETIVO: Descrever os resultados do Programa para o Uso Racional de Antimicrobianos no Hospital Juárez de México. MÉTODOS: Elaboramos um estudo observacional, transversal, retrospectivo e descritivo. Analisamos o consumo de antimicrobianos de janeiro de 2013 a dezembro de 2018 pelo cálculo da dose diária definida (DDD); para a análise de custos, realizamos um cálculo de custos tradicional. RESULTADOS: No grupo dos carbapenens, a redução do consumo de imipenem/cilastatina foi notável: passou-se de uma DDD de 2,3 em 2013 para 0,7 em 2018, uma redução de 70%. Por outro lado, observou-se um aumento no uso dos dois outros medicamentos: no caso do meropenem, foi registrado um aumento de 2% (de 2,4 em 2013 a 2,5 em 2018); no consumo de ertapenem o aumento foi de 75% (de 1 em 2013 a 1,8 em 2018). No total, as despesas com antimicrobianos foram de USD 930 556,46 em 2013 e de USD 856 079,10 em 2018, uma diferença de 8%, o que equivale a uma redução de USD 74 905,61 nas despesas totais. CONCLUSÕES: É necessário avaliar continuamente os programas para o uso racional de antimicrobianos pelo monitoramento do consumo e das despesas derivadas.

19.
Int J Mol Sci ; 21(14)2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32709107

RESUMO

Recent studies suggest that Tyr-39 might play a critical role for both the normal function and the pathological dysfunction of α-synuclein (αS), an intrinsically disordered protein involved in Parkinson's disease. We perform here a comparative analysis between the structural features of human αS and its Y39A, Y39F, and Y39L variants. By the combined application of site-directed mutagenesis, biophysical techniques, and enhanced sampling molecular simulations, we show that removing aromatic functionality at position 39 of monomeric αS leads to protein variants populating more compact conformations, conserving its disordered nature and secondary structure propensities. Contrasting with the subtle changes induced by mutations on the protein structure, removing aromaticity at position 39 impacts strongly on the interaction of αS with the potent amyloid inhibitor phthalocyanine tetrasulfonate (PcTS). Our findings further support the role of Tyr-39 in forming essential inter and intramolecular contacts that might have important repercussions for the function and the dysfunction of αS.


Assuntos
Amiloide/química , Proteínas Intrinsicamente Desordenadas/química , alfa-Sinucleína/química , Amiloide/genética , Humanos , Proteínas Intrinsicamente Desordenadas/genética , Doença de Parkinson/genética , Mutação Puntual , Conformação Proteica , Tirosina/química , Tirosina/genética , alfa-Sinucleína/genética
20.
Cell Physiol Biochem ; 53(6): 948-960, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31820855

RESUMO

BACKGROUND/AIMS: HOTAIR is a long non-coding RNA that promotes the development of human cancer. TET1 enzyme is involved in DNA demethylation by oxidation of 5-methylcytocine and it is considered a tumor suppressor in some types of cancer. HOTAIR and TET1 are involved in modulation of the Wnt/ß-catenin signaling pathway, but their role in cervical cancer remains to be elucidated. The aim of this work was to analyze the effect of HOTAIR in TET1 expression, Wnt/ß-catenin signaling, and expression, methylation and hidroxymethylation of some negative regulators of this pathway in HeLa cells. METHODS: HOTAIR and TET expression were analyzed by RT-qPCR and western blot. The HOTAIR knockdown was done with DsiRNA and the activity of the Wnt/ß-catenin signaling pathway through luciferase assays and ß-catenin nuclear translocation. The mRNA levels of SNAIL, EDN3, CYCD1, SPRY2 (targets of Wnt/ß-catenin pathway) PCDH10, SOX17, AJAP1, and MAGI2 (negative regulators of Wnt/ß-catenin pathway) were evaluated by RT-qPCR. The DNA methylation and hidroxymethylation of negative regulators of the Wnt/ß-catenin pathway were evaluated by methylation-specific PCR and chemical modification, followed by digestion and quantitative PCR. RESULTS: HOTAIR knockdown in HeLa cells decreased the activity of Wnt/ß-catenin signaling pathway. It increased the mRNA levels of Wnt/ ß-catenin negative regulators through a decrease in their promoter's methylation pattern. TET1 enzyme was also down-regulated in HOTAIR knockdown cells. CONCLUSION: Our study suggests a mechanism in which HOTAIR promotes the over-activation of Wnt/ß-catenin signaling pathway by downregulation of PCDH10, SOX17, AJAP1 and MAGI2 and also TET.


Assuntos
RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Via de Sinalização Wnt , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Metilação de DNA , Guanilato Quinases/genética , Guanilato Quinases/metabolismo , Células HeLa , Humanos , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Interferência de RNA , RNA Longo não Codificante/antagonistas & inibidores , RNA Longo não Codificante/genética , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição SOXF/genética , Fatores de Transcrição SOXF/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
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