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1.
Mol Cell Biochem ; 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39316324

RESUMEN

The increasing prevalence of screen time among modern citizens has raised concerns regarding its potential impact on neuroinflammation and overall brain health. This review examines the complex interconnections between screen time and neuroinflammatory processes, particularly in children and adolescents. We analyze existing literature that explores how excessive digital media use can lead to alterations in neurobiological pathways, potentially exacerbating inflammatory responses in the brain. Key findings suggest that prolonged exposure to screens may contribute to neuroinflammation through mechanisms such as disrupted sleep patterns, diminished cognitive engagement, and increased stress levels. Similarly, we discuss the implications of these findings for mental health and cognitive development, emphasizing the need for a balanced approach to screen time. This review highlights the necessity for further research to elucidate the causal relationships and underlying mechanisms linking screen time and neuroinflammation, thereby informing guidelines for healthy media consumption.

2.
J Chem Inf Model ; 64(19): 7743-7757, 2024 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-39283165

RESUMEN

Identifying druggable binding sites on proteins is an important and challenging problem, particularly for cryptic, allosteric binding sites that may not be obvious from X-ray, cryo-EM, or predicted structures. The Site-Identification by Ligand Competitive Saturation (SILCS) method accounts for the flexibility of the target protein using all-atom molecular simulations that include various small molecule solutes in aqueous solution. During the simulations, the combination of protein flexibility and comprehensive sampling of the water and solute spatial distributions can identify buried binding pockets absent in experimentally determined structures. Previously, we reported a method for leveraging the information in the SILCS sampling to identify binding sites (termed Hotspots) of small mono- or bicyclic compounds, a subset of which coincide with known binding sites of drug-like molecules. Here, we build on that physics-based approach and present a ML model for ranking the Hotspots according to the likelihood they can accommodate drug-like molecules (e.g., molecular weight >200 Da). In the independent validation set, which includes various enzymes and receptors, our model recalls 67% and 89% of experimentally validated ligand binding sites in the top 10 and 20 ranked Hotspots, respectively. Furthermore, we show that the model's output Decision Function is a useful metric to predict binding sites and their potential druggability in new targets. Given the utility the SILCS method for ligand discovery and optimization, the tools presented represent an important advancement in the identification of orthosteric and allosteric binding sites and the discovery of drug-like molecules targeting those sites.


Asunto(s)
Aprendizaje Automático , Sitios de Unión , Ligandos , Proteínas/química , Proteínas/metabolismo , Unión Proteica , Simulación de Dinámica Molecular , Conformación Proteica , Descubrimiento de Drogas/métodos
3.
Chemphyschem ; 24(10): e202200784, 2023 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-36735449

RESUMEN

We demonstrate a cost-effective alternative employing the fragment-based molecular tailoring approach (MTA) for building the potential energy surface (PES) for two dipeptides viz. alanine-alanine and alanine-proline employing correlated theory, with augmented Dunning basis sets. About 1369 geometries are generated for each test dipeptide by systematically varying the dihedral angles Φ ${{\rm{\Phi }}}$ and Ψ ${{{\Psi }}}$ . These conformational geometries are partially optimized by relaxing all the other Z-matrix parameters, fixing the values of Φ ${{\rm{\Phi }}}$ and Ψ ${{{\Psi }}}$ . The MP2 level PES is constructed from the MTA-energies of chemically intact geometries using minimal hardware. The fidelity of MP2/aug-cc-pVDZ level PES is brought out by comparing it with its full calculation counterpart. Further, we bring out the power of the method by reporting the MTA-based CCSD/aug-cc-pVDZ level PES for these two dipeptides containing 498 and 562 basis functions respectively.

4.
Int J Mol Sci ; 22(7)2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33805564

RESUMEN

The overactivation of Wnt/ß-catenin signaling is a hallmark of colorectal cancer (CRC) development. We identified the cell adhesion molecule L1CAM (L1) as a target of ß-catenin-TCF transactivation in CRC cells. The overexpression of L1 in CRC cells confers enhanced proliferation, motility, tumorigenesis and liver metastasis, and L1 is exclusively localized in the invasive areas of human CRC tissue. A number of genes are induced after L1 transfection into CRC cells by a mechanism involving the cytoskeletal protein ezrin and the NF-κB pathway. When studying the changes in gene expression in CRC cells overexpressing L1 in which ezrin levels were suppressed by shRNA to ezrin, we discovered the collagen-modifying enzyme lysyl hydroxylase 2 (PLOD2) among these genes. We found that increased PLOD2 expression was required for the cellular processes conferred by L1, including enhanced proliferation, motility, tumorigenesis and liver metastasis, since the suppression of endogenous PLOD2 expression, or its enzymatic activity, blocked the enhanced tumorigenic properties conferred by L1. The mechanism involved in increased PLOD2 expression by L1 involves ezrin signaling and PLOD2 that affect the SMAD2/3 pathway. We found that PLOD2 is localized in the colonic crypts in the stem cell compartment of the normal mucosa and is found at increased levels in invasive areas of the tumor and, in some cases, throughout the tumor tissue. The therapeutic strategies to target PLOD2 expression might provide a useful approach for CRC treatment.


Asunto(s)
Neoplasias del Colon/patología , Procolágeno-Lisina 2-Oxoglutarato 5-Dioxigenasa/metabolismo , Animales , Línea Celular Tumoral , Movimiento Celular , Colágeno/metabolismo , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Proteínas del Citoesqueleto/metabolismo , Regulación Neoplásica de la Expresión Génica , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/secundario , Masculino , Ratones Desnudos , Molécula L1 de Adhesión de Célula Nerviosa/metabolismo , Procolágeno-Lisina 2-Oxoglutarato 5-Dioxigenasa/genética , Proteína Smad2/metabolismo , Proteína smad3/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
5.
Int J Mol Sci ; 23(1)2021 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-35008869

RESUMEN

Aberrant activation of Wnt/ß-catenin signaling and downstream ß-catenin-TCF target genes is a hallmark of colorectal cancer (CRC) development. We identified the immunoglobulin-like cell adhesion receptor L1CAM (L1) as a target of ß-catenin-TCF transactivation in CRC cells. Overexpression of L1 in CRC cells confers enhanced proliferation, motility, tumorigenesis, and liver metastasis, and L1 is exclusively localized at invasive areas of human CRC tissue. Several genes are induced after L1 transfection into CRC cells by a mechanism involving the L1-ezrin-NF-κB pathway. We conducted a secretomic analysis of the proteins in the culture medium of L1-overexpressing CRC cells. We detected a highly increased level of biglycan, a small leucine-rich ECM component, and a signaling molecule. We found that induction of biglycan is required for the cellular processes conferred by L1, including enhanced proliferation, motility, tumorigenesis, and liver metastasis. The suppression of endogenous biglycan levels or a point mutation in the L1 ectodomain that regulates cell-cell adhesion mediated by L1 blocked the enhanced tumorigenic properties conferred by L1. The mechanism of biglycan induction by L1 involves the L1-NF-κB pathway. Blocking NF-κB signaling in L1 expressing cells suppressed the induction of biglycan and the tumorigenic properties conferred by L1. Biglycan expression was undetectable in the normal colonic mucosa, but expressed at highly increased levels in the tumor tissue, especially in the stroma. The therapeutic strategies to target biglycan expression might provide a useful approach for CRC treatment in L1-overexpressing tumors.


Asunto(s)
Biglicano/metabolismo , Moléculas de Adhesión Celular/metabolismo , Neoplasias Colorrectales/metabolismo , FN-kappa B/metabolismo , Animales , Adhesión Celular , Línea Celular Tumoral , Movimiento Celular , Humanos , Masculino , Ratones , Ratones Desnudos
6.
J Comput Chem ; 41(9): 958-970, 2020 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-31886576

RESUMEN

Accurate force-field (FF) parameters are key to reliable prediction of properties obtained from molecular modeling (MM) and molecular dynamics (MD) simulations. With ever-widening applicability of MD simulations, robust parameters need to be generated for a wider range of chemical species. The CHARMM General Force Field program (CGenFF, https://cgenff.umaryland.edu/) is a tool for obtaining initial parameters for a given small molecule based on analogy with the available CGenFF parameters. However, improvement of these parameters is often required and performing their optimization remains tedious and time consuming. In addition, tools for optimization of small molecule parameters in the context of the Drude polarizable FF are not yet available. To overcome these issues, the FFParam package has been designed to facilitate the parametrization process. The package includes a graphical user interface (GUI) created using Qt libraries. FFParam supports Gaussian and Psi4 for performing quantum mechanical calculations and CHARMM and OpenMM for MM calculations. A Monte Carlo simulated annealing (MCSA) algorithm has been implemented for automated fitting of partial atomic charge, atomic polarizabilities and Thole scale parameters. The LSFITPAR program is called for automated fitting of bonded parameters. Accordingly, FFParam provides all the features required for generation and analysis of CHARMM and Drude FF parameters for small molecules. FFParam-GUI includes a text editor, graph plotter, molecular visualization, and text to table converter to meet various requirements of the parametrization process. It is anticipated that FFParam will facilitate wider use of CGenFF as well as promote future use of the Drude polarizable FF.


Asunto(s)
Algoritmos , Simulación de Dinámica Molecular , Bibliotecas de Moléculas Pequeñas/química , Programas Informáticos , Estructura Molecular , Método de Montecarlo
8.
Mol Carcinog ; 57(9): 1102-1115, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29672923

RESUMEN

Epithelial-mesenchymal transition (EMT) is a critical event that occurs during the invasion and metastatic spread of cancer cells. Here, we conceive a dual mechanism of Par-4-mediated inhibition of EMT and induction of MET in metastatic pancreatic cancer cells. First, we demonstrate that 1,1'-ß-D-glucopyranosyl-3,3'-bis(5-bromoindolyl)-octyl methane (NGD16), an N-glycosylated derivative of medicinally important phytochemical 3,3'-diindolylmethane (DIM) abrogates EMT by inducing pro-apoptotic protein Par-4. Induction of Par-4 (by NGD16 or ectopic overexpression) strongly impedes invasion with inhibition of major mesenchymal markers viz. Vimentin and Twist-1 epithelial marker- E-cadherin. Further, NGD16 triggers MET phenotypes in pancreatic cancer cells by augmenting ALK2/Smad4 signaling in a Par-4-dependent manner. Conversely, siRNA-mediated silencing of endogenous Par-4 unveil reversal of MET with diminished E-cadherin expression and invasive phenotypes. Additionally, we demonstrate that intact Smad4 is essential for Par-4-mediated maintenance of E-cadherin level in MET induced cells. Notably, we imply that Par-4 induction regulates E-cadherin levels in the pancreatic cancer cells via modulating Twist-1 promoter activity. Finally, in vivo studies with syngenic mouse metastatic pancreatic cancer model reveal that NGD16 strongly suppresses metastatic burden, ascites formation, and prolongs the overall survival of animals effectively.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/genética , Transición Epitelial-Mesenquimal , Regulación Neoplásica de la Expresión Génica , Invasividad Neoplásica/genética , Neoplasias Pancreáticas/genética , Animales , Cadherinas/genética , Línea Celular Tumoral , Transición Epitelial-Mesenquimal/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Indoles/farmacología , Indoles/uso terapéutico , Masculino , Ratones Endogámicos C57BL , Invasividad Neoplásica/patología , Invasividad Neoplásica/prevención & control , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/patología , Interferencia de ARN , ARN Interferente Pequeño/genética
9.
PLoS Genet ; 11(12): e1005710, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26681446

RESUMEN

Degeneration of nigrostriatal dopaminergic system is the principal lesion in Parkinson's disease. Because glial cell line-derived neurotrophic factor (GDNF) promotes survival of dopamine neurons in vitro and in vivo, intracranial delivery of GDNF has been attempted for Parkinson's disease treatment but with variable success. For improving GDNF-based therapies, knowledge on physiological role of endogenous GDNF at the sites of its expression is important. However, due to limitations of existing genetic model systems, such knowledge is scarce. Here, we report that prevention of transcription of Gdnf 3'UTR in Gdnf endogenous locus yields GDNF hypermorphic mice with increased, but spatially unchanged GDNF expression, enabling analysis of postnatal GDNF function. We found that increased level of GDNF in the central nervous system increases the number of adult dopamine neurons in the substantia nigra pars compacta and the number of dopaminergic terminals in the dorsal striatum. At the functional level, GDNF levels increased striatal tissue dopamine levels and augmented striatal dopamine release and re-uptake. In a proteasome inhibitor lactacystin-induced model of Parkinson's disease GDNF hypermorphic mice were protected from the reduction in striatal dopamine and failure of dopaminergic system function. Importantly, adverse phenotypic effects associated with spatially unregulated GDNF applications were not observed. Enhanced GDNF levels up-regulated striatal dopamine transporter activity by at least five fold resulting in enhanced susceptibility to 6-OHDA, a toxin transported into dopamine neurons by DAT. Further, we report how GDNF levels regulate kidney development and identify microRNAs miR-9, miR-96, miR-133, and miR-146a as negative regulators of GDNF expression via interaction with Gdnf 3'UTR in vitro. Our results reveal the role of GDNF in nigrostriatal dopamine system postnatal development and adult function, and highlight the importance of correct spatial expression of GDNF. Furthermore, our results suggest that 3'UTR targeting may constitute a useful tool in analyzing gene function.


Asunto(s)
Dopamina/genética , Neuronas Dopaminérgicas/metabolismo , Factor Neurotrófico Derivado de la Línea Celular Glial/genética , Enfermedad de Parkinson Secundaria/genética , Sustancia Negra/metabolismo , Acetilcisteína/análogos & derivados , Acetilcisteína/toxicidad , Animales , Sistema Nervioso Central/metabolismo , Sistema Nervioso Central/patología , Modelos Animales de Enfermedad , Dopamina/metabolismo , Neuronas Dopaminérgicas/patología , Regulación del Desarrollo de la Expresión Génica , Factor Neurotrófico Derivado de la Línea Celular Glial/biosíntesis , Humanos , Riñón/crecimiento & desarrollo , Riñón/metabolismo , Ratones , Neostriado/metabolismo , Neostriado/patología , Fármacos Neuroprotectores/metabolismo , Enfermedad de Parkinson Secundaria/inducido químicamente , Enfermedad de Parkinson Secundaria/patología , Sustancia Negra/patología
10.
Mol Carcinog ; 55(5): 864-81, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-25969134

RESUMEN

Here, we provide evidences that natural product derivative 3-azido Withaferin A (3-AWA) abrogated EMT and invasion by modulating ß-catenin localization and its transcriptional activity in the prostate as well as in breast cancer cells. This study, for the first time, reveals 3-AWA treatment consistently sequestered nuclear ß-catenin and augmented its cytoplasmic pool as evidenced by reducing ß-catenin transcriptional activity in these cells. Moreover, 3-AWA treatment triggered robust induction of pro-apoptotic intracellular Par-4, attenuated Akt activity and rescued Phospho-GSK3ß (by Akt) to promote ß-catenin destabilization. Further, our in vitro studies demonstrate that 3-AWA treatment amplified E-cadherin expression along with sharp downregulation of c-Myc and cyclin D1 proteins. Strikingly, endogenous Par-4 knock down by siRNA underscored 3-AWA mediated inhibition of nuclear ß-catenin was Par-4 dependent and suppression of Par-4 activity, either by Bcl-2 or by Ras transfection, restored the nuclear ß-catenin level suggesting Par-4 mediated ß-catenin regulation was not promiscuous. In vivo results further demonstrated that 3-AWA was effective inhibitor of tumor growth and immunohistochemical studies indicated that increased expression of total ß-catenin and decreased expression of phospho-ß-catenin and Par-4 in breast cancer tissues as compared to normal breast tissue suggesting Par-4 and ß-catenin proteins are mutually regulated and inversely co-related in normal as well as cancer condition. Thus, strategic regulation of intracellular Par-4 by 3-AWA in diverse cancers could be an effective tool to control cancer cell metastasis. Conclusively, this report puts forward a novel approach of controlling deregulated ß-catenin signaling by 3-AWA induced Par-4 protein.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Proteínas Reguladoras de la Apoptosis/metabolismo , Neoplasias/tratamiento farmacológico , Witanólidos/agonistas , beta Catenina/metabolismo , Animales , Antineoplásicos Fitogénicos/farmacología , Apoptosis , Línea Celular Tumoral , Transición Epitelial-Mesenquimal/efectos de los fármacos , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Células MCF-7 , Ratones , Neoplasias/metabolismo , Fosforilación/efectos de los fármacos , Plantas Medicinales/química , Transducción de Señal/efectos de los fármacos
11.
J Immunoassay Immunochem ; 37(3): 228-42, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26674740

RESUMEN

The relatively short circulatory half-life (2-3 min) of staphylokinase is a major drawback in the development of SAK- (staphylokinase) based thrombolytic drug. A rapid and sensitive method, based on indirect competitive ELISA, was developed and validated for quantitative determination of SAK in rabbit plasma. The dynamic range of the assay varied between 0.41 ± 0.16 µg/L and 9.03 ± 0.38 µg/L (R(2) = 0.98) for SAK in rabbit plasma. There were no dilution linearity issues apparent with this assay. The precision (% CV) ranged from 4.6-9.7% for the intraassay and from 17.1-19.3% for interassay. This validated method was successfully employed for evaluation of various pharmacokinetic parameters of SAK in rabbit.


Asunto(s)
Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/normas , Fibrinolíticos/farmacocinética , Metaloendopeptidasas/sangre , Animales , Femenino , Fibrinolíticos/sangre , Masculino , Metaloendopeptidasas/metabolismo , Ratones , Ratones Endogámicos BALB C , Conejos , Proteínas Recombinantes/sangre , Proteínas Recombinantes/metabolismo
12.
J Comput Chem ; 36(31): 2350-9, 2015 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-26505259

RESUMEN

DAMQT-2.1.0 is a new version of DAMQT package which includes topographical analysis of molecular electron density (MED) and molecular electrostatic potential (MESP), such as mapping of critical points (CPs), creating molecular graphs, and atomic basins. Mapping of CPs is assisted with algorithmic determination of Euler characteristic in order to provide a necessary condition for locating all possible CPs. Apart from the mapping of CPs and determination of molecular graphs, the construction of MESP-based atomic basin is a new and exclusive feature introduced in DAMQT-2.1.0. The GUI in DAMQT provides a user-friendly interface to run the code and visualize the final outputs. MPI libraries have been implemented for all the tasks to develop the parallel version of the software. Almost linear scaling of computational time is achieved with the increasing number of processors while performing various aspects of topography. A brief discussion of molecular graph and atomic basin is provided in the current article highlighting their chemical importance. Appropriate example sets have been presented for demonstrating the functions and efficiency of the code.


Asunto(s)
Electrones , Programas Informáticos , Electricidad Estática
13.
Phys Chem Chem Phys ; 17(22): 15030-5, 2015 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-25988720

RESUMEN

The nature of electron localization in electrides is explored by examining their electrostatic features. Ab initio investigations of three experimentally synthesized and two theoretically modeled organic electrides are performed in order to unveil the characteristics of the trapped electron and to understand the reason for their low thermal stability. A single molecular unit of the electride extracted from the crystal structure shows an unusually deep minimum in its electrostatic potential, located far away from its van der Waals surface. A comparison of electrostatic features of the usual electron localization such as lone pairs has been drawn against those of the trapped electron in the crystal voids of electrides. Further characterization of the MESP minimum brings out the isotropic behavior of the trapped electrons as compared to the lone-pair minimum which is strongly directional. The analysis of single molecular behavior of an electride has been extended to the set of molecules in the unit cell of the crystal lattice. The present study also suggests the criteria for ligands to achieve thermally stable organic electrides.

14.
Phys Chem Chem Phys ; 17(23): 15258-73, 2015 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-25992948

RESUMEN

The topological diversity of sets of isomers of water clusters (W = H2O)n, 7 ≤ n ≤ 10, is analyzed employing the scalar fields of total electronic charge density ρ(r) and the molecular electrostatic potential (MESP). The features uncovered by the MESP are shown to be complementary to those revealed by the theory of atoms in molecules (QTAIM) analysis. The MESP is known to exhibit the electron localizations such as lone pairs that are central to water cluster behavior. Therefore, a 'hybrid' QTAIM and MESP quantum topology phase diagram (QTPD) for Wn, 7 ≤ n ≤ 10, is introduced in addition to the QTPD. The 'spanning' QTPD with upper and lower bounds is constructed from the solutions of the Poincaré-Hopf relation involving the non-degenerate critical points. The changing subtle balance between the planar and three dimensional character of the growing water clusters Wn, 4 ≤ n ≤ 10, is revealed. Characterization of the structure of the QTPDs, possible with new tools, demonstrated the migration of the position of the global minimum on the spanning QTPD from the lower bound to upper bound as the Wn, 4 ≤ n ≤ 10, cluster grows in size. Differences in the structure of the QTPD are found between the clusters containing even versus odd monomers for Wn, n = 7-10. The energetic stability of the clusters which possess even number of monomers viz. n = 8, 10 is higher than that of the n = 7, 9 clusters due to relatively higher numbers of hydrogen-bond BCPs in the n = 8, 10 clusters, in agreement with energetic results reported in the literature. A 'hybrid' QTPD is created from a new chemical relation bHB + l ≥ 2n for Wn that relates the number of hydrogen-bond bond critical points (bHB) with the number of oxygen lone pairs exclusively specified by the negative valued MESP (3,+3) critical points (l). The topologies of the subset bHB + l = 2n for Wn, point the way to the discovery of unknown 'missing' lower energy isomers. A discussion of the relative merits and range of applicability of the QTAIM and hybrid-QTPD analyses is included and concludes that the hybrid-QTPD analysis for Wn, is more useful for the association with the energy minima on the potential energy surface.

15.
Cell Mol Life Sci ; 71(22): 4443-56, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24804980

RESUMEN

Brain-derived neurotrophic factor (BDNF) is a secreted protein of the neurotrophin family that regulates brain development, synaptogenesis, memory and learning, as well as development of peripheral organs, such as angiogenesis in the heart and postnatal growth and repair of skeletal muscle. However, while precise regulation of BDNF levels is an important determinant in defining the biological outcome, the role of microRNAs (miRs) in modulating BDNF expression has not been extensively analyzed. Using in silico approaches, reporter systems, and analysis of endogenous BDNF, we show that miR-1, miR-10b, miR-155, and miR-191 directly repress BDNF through binding to their predicted sites in BDNF 3'UTR. We find that the overexpression of miR-1 and miR-10b suppresses endogenous BDNF protein levels and that silencing endogenous miR-10b increases BDNF mRNA and protein levels. Furthermore, we show that miR-1/206 binding sites within BDNF 3'UTR are used in differentiated myotubes but not in undifferentiated myoblasts. Finally, our data from two cell lines suggest that endogenous miR-1/206 and miR-10 family miRs act cooperatively in suppressing BDNF through their predicted sites in BDNF 3'UTR. In conclusion, our results highlight miR-1, miR-10b, miR-155, and miR-191 as novel regulators of BDNF long and short 3'UTR isoforms, supporting future research in different physiological and pathological contexts.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , MicroARNs/metabolismo , Regiones no Traducidas 3' , Animales , Secuencia de Bases , Sitios de Unión , Factor Neurotrófico Derivado del Encéfalo/genética , Línea Celular , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , ARN Mensajero/metabolismo , Alineación de Secuencia
16.
J Phys Chem A ; 118(2): 526-32, 2014 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-24372481

RESUMEN

A clear-cut definition of lone pairs has been offered in terms of characteristics of minima in molecular electrostatic potential (MESP). The largest eigenvalue and corresponding eigenvector of the Hessian at the minima are shown to distinguish lone pair regions from the other types of electron localization (such as π bonds). A comparative study of lone pairs as depicted by various other scalar fields such as the Laplacian of electron density and electron localization function is made. Further, an attempt has been made to generalize the definition of lone pairs to the case of cations.

17.
J Phys Chem B ; 128(18): 4385-4395, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38690986

RESUMEN

Developing production quality CHARMM force-field (FF) parameters is a very detailed process involving a variety of calculations, many of which are specific for the molecule of interest. The first version of FFParam was developed as a standalone Python package designed for the optimization of electrostatic and bonded parameters of the CHARMM additive and polarizable Drude FFs by using quantum mechanical (QM) target data. The new version of FFParam has multiple new capabilities for FF parameter optimization and validation, with an emphasis on the ability to use condensed-phase target data in optimization. FFParam-v2 allows optimization of Lennard-Jones (LJ) parameters using potential energy scans of interactions between selected atoms in a molecule and noble gases, viz., He and Ne, and through condensed-phase calculations, from which experimental observables such as heats of vaporization and free energies of solvation may be obtained. This functionality serves as a gold standard for both optimizing parameters and validating the performance of the final parameters. A new bonded parameter optimization algorithm has been introduced to account for simultaneously optimizing multiple molecules sharing parameters. FFParam-v2 also supports the comparison of normal modes and the potential energy distribution of internal coordinates towards each normal mode obtained from QM and molecular mechanics calculations. Such comparison capability is vital to validate the balance among various bonded parameters that contribute to the complex normal modes of molecules. User interaction has been extended beyond the original graphical user interface to include command-line interface capabilities that allow for integration of FFParam in workflows, thereby facilitating the automation of parameter optimization. With these new functionalities, FFParam is a more comprehensive parameter optimization tool for both beginners and advanced users.

18.
Sci Rep ; 14(1): 13453, 2024 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-38862513

RESUMEN

Individuals with type 1 diabetes (T1D) carry a markedly increased risk of stroke, with distinct clinical and neuroimaging characteristics as compared to those without diabetes. Using whole-exome or whole-genome sequencing of 1,051 individuals with T1D, we aimed to find rare and low-frequency genomic variants associated with stroke in T1D. We analysed the genome comprehensively with single-variant analyses, gene aggregate analyses, and aggregate analyses on genomic windows, enhancers and promoters. In addition, we attempted replication in T1D using a genome-wide association study (N = 3,945) and direct genotyping (N = 3,263), and in the general population from the large-scale population-wide FinnGen project and UK Biobank summary statistics. We identified a rare missense variant on SREBF1 exome-wide significantly associated with stroke (rs114001633, p.Pro227Leu, p-value = 7.30 × 10-8), which replicated for hemorrhagic stroke in T1D. Using gene aggregate analysis, we identified exome-wide significant genes: ANK1 and LRRN1 displayed replication evidence in T1D, and LRRN1, HAS1 and UACA in the general population (UK Biobank). Furthermore, we performed sliding-window analyses and identified 14 genome-wide significant windows for stroke on 4q33-34.1, of which two replicated in T1D, and a suggestive genomic window on LINC01500, which replicated in T1D. Finally, we identified a suggestively stroke-associated TRPM2-AS promoter (p-value = 5.78 × 10-6) with borderline significant replication in T1D, which we validated with an in vitro cell-based assay. Due to the rarity of the identified genetic variants, future replication of the genomic regions represented here is required with sequencing of individuals with T1D. Nevertheless, we here report the first genome-wide analysis on stroke in individuals with diabetes.


Asunto(s)
Ancirinas , Diabetes Mellitus Tipo 1 , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Accidente Cerebrovascular , Secuenciación Completa del Genoma , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ancirinas/genética , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/complicaciones , Proteínas de la Membrana/genética , Polimorfismo de Nucleótido Simple , Secuencias Reguladoras de Ácidos Nucleicos/genética , Accidente Cerebrovascular/genética
19.
Phys Chem Chem Phys ; 15(42): 18401-9, 2013 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-24085157

RESUMEN

An electrostatics-based approach has been proposed for probing the weak interactions between lone pair containing molecules and π deficient molecular systems. For electron-rich molecules, the negative minima in molecular electrostatic potential (MESP) topography give the location of electron localization and the MESP value at the minimum (Vmin) quantifies the electron-rich character of that region. Interactive behavior of a lone pair bearing molecule with electron deficient π-systems, such as hexafluorobenzene, 1,3,5-trinitrobenzene, 2,4,6-trifluoro-1,3,5-triazine and 1,2,4,5-tetracyanobenzene explored within DFT brings out good correlation of the lone pair-π interaction energy (E(int)) with the Vmin value of the electron-rich system. Such interaction is found to be portrayed well with the Electrostatic Potential for Intermolecular Complexation (EPIC) model. On the basis of the precise location of MESP minimum, a prediction for the orientation of a lone pair bearing molecule with an electron deficient π-system is possible in the majority of the cases studied.


Asunto(s)
Compuestos Orgánicos/química , Electricidad Estática , Electrones , Modelos Moleculares , Conformación Molecular , Teoría Cuántica
20.
Can J Physiol Pharmacol ; 91(10): 839-47, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24144055

RESUMEN

Reocclusion is one of the major root causes for secondary complications that arise during thrombolytic therapy. A multifunctional staphylokinase variant SRH (staphylokinase (SAK) linked with tripeptide RGD and didecapeptide Hirulog) with antiplatelet and antithrombin activities in addition to clot specific thrombolytic function, was developed to address the reocclusion problem. We preferred to use Escherichia coli GJ1158 as the host in this study for economic production of SRH by osmotic (0.3 mol/L sodium chloride) induction, to overcome the problems associated with the yeast expression system. The therapeutic potential of SRH was evaluated in the murine model of vascular thrombosis. The SAK protein (1 mg/kg body mass) and SRH protein (1 mg/kg and 2 mg/kg) were administered intravenously to the different treatment groups. The results have shown a dose-dependent antithrombotic effect in carrageenan-induced mouse tail thrombosis. The thrombin time, activated partial thromboplastin time, and prothrombin time were significantly prolonged (p < 0.05) in the SRH-infused groups. Moreover, SRH inhibited platelet aggregation in a dose-dependent manner (p < 0.05), while the bleeding time was significantly (p < 0.05) prolonged. All of these results inferred that the osmotically produced multifunctional fusion protein SRH (SAK-RGD-Hirulog) is a promising thrombolytic agent, and one which sustained its multifunctionality in the animal models.


Asunto(s)
Antitrombinas/farmacología , Escherichia coli/enzimología , Hirudinas/farmacología , Metaloendopeptidasas/farmacología , Oligopéptidos/farmacología , Fragmentos de Péptidos/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Agregación Plaquetaria/efectos de los fármacos , Trombosis/tratamiento farmacológico , Animales , Coagulación Sanguínea/efectos de los fármacos , Carragenina , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Escherichia coli/genética , Hirudinas/biosíntesis , Hirudinas/genética , Masculino , Metaloendopeptidasas/biosíntesis , Metaloendopeptidasas/genética , Ratones , Ratones Endogámicos BALB C , Oligopéptidos/biosíntesis , Oligopéptidos/genética , Tiempo de Tromboplastina Parcial , Fragmentos de Péptidos/biosíntesis , Fragmentos de Péptidos/genética , Tiempo de Protrombina , Ratas , Ratas Sprague-Dawley , Proteínas Recombinantes de Fusión/farmacología , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Cloruro de Sodio/química , Tiempo de Trombina , Trombosis/sangre , Trombosis/inducido químicamente , Factores de Tiempo
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