Read by QxMD icon Read

Cellular theory

Junghyun L Suh, Brian Watts, Jacob I Stuckey, Jacqueline L Norris-Drouin, Stephanie H Cholensky, Bradley M Dickson, Yi An, Sebastian Mathea, Eidarus Salah, Stefan Knapp, Abid Khan, Alexander T Adams, Brian D Strahl, Cari A Sagum, Mark T Bedford, Lindsey I James, Dmitri B Kireev, Stephen V Frye
Multivalent binding is an efficient means to enhance the affinity and specificity of chemical probes targeting multi-domain proteins in order to study their function and role in disease. While the theory of multivalent binding is straightforward, physical and structural characterization of bivalent binding encounters multiple technical difficulties. We present a case study where a combination of experimental techniques and computational simulations was used to comprehensively characterize the binding and structure-affinity relationships for a series of Bromosporine-based bivalent bromodomain ligands with a bivalent protein, Transcription Initiation Factor TFIID subunit 1 (TAF1)...
March 20, 2018: Biochemistry
Audrey M Bernstein, Robert Ritch, J Mario Wolosin
Exfoliation syndrome (XFS) is an age-related disease involving the deposition of aggregated fibrillar material (XFM) at extracellular matrices in tissues that synthesize elastic fibers. Its main morbidity is in the eye, where XFM accumulations form on the surface of the ciliary body, iris and lens. Exfoliation glaucoma (XFG) occurs in a high proportion of persons with XFS and can be a rapidly progressing disease. Worldwide, XFG accounts for about 25% of open-angle glaucoma cases. XFS and XFG show a sharp age-dependence, similarly to the many age-related diseases classified as aggregopathies...
March 15, 2018: Journal of Glaucoma
Angelica Nakagawa Lima, Ronaldo Junio de Oliveira, Antônio Sérgio Kimus Braz, Maurício Garcia de Souza Costa, David Perahia, Luis Paulo Barbour Scott
There are two different prion conformations: (1) the cellular natural (PrPC ) and (2) the scrapie (PrPSc ), an infectious form that tends to aggregate under specific conditions. PrPC and PrPSc are widely different regarding secondary and tertiary structures. PrPSc contains more and longer β-strands compared to PrPC . The lack of solved PrPSc structures precludes a proper understanding of the mechanisms related to the transition between cellular and scrapie forms, as well as the aggregation process. In order to investigate the conformational transition between PrPC and PrPSc , we applied MDeNM (molecular dynamics with excited normal modes), an enhanced sampling simulation technique that has been recently developed to probe large structural changes...
March 15, 2018: European Biophysics Journal: EBJ
Boldizsár Czéh, Szilvia A Nagy
Depressive disorders are complex, multifactorial mental disorders with unknown neurobiology. Numerous theories aim to explain the pathophysiology. According to the "gliocentric theory", glial abnormalities are responsible for the development of the disease. The aim of this review article is to summarize the rapidly growing number of cellular and molecular evidences indicating disturbed glial functioning in depressive disorders. We focus here exclusively on the clinical studies and present the in vivo neuroimaging findings together with the postmortem molecular and histopathological data...
2018: Frontiers in Molecular Neuroscience
Natalie C Rollick, Devin B Lemmex, Yohei Ono, Carol R Reno, David A Hart, Ian Ky Lo, Gail M Thornton
Background: When considering the "joint as an organ", the tissues in a joint act as complementary components of an organ, and the "set point" is the cellular activity for homeostasis of the joint tissues. Even in the absence of injury, joint tissues have adaptive responses to processes, like aging and menopause, which result in changes to the set point. Purpose: The purpose of this study in a preclinical model was to investigate age-related and menopause-related changes in knee-joint tissues with the hypothesis that tissues will change in unique ways that reflect their differing contributions to maintaining joint function (as measured by joint laxity) and the differing processes of aging and menopause...
2018: Clinical Interventions in Aging
Masanori Nomoto, Kaoru Inokuchi
Behavioral tagging is the transformation of a short-term memory induced by a weak experience into a long-term memory through temporal association with a novel experience. This phenomenon was discovered to recapitulate synaptic tagging and capture at the behavioral level. Significant progress has been made in determining the molecular machinery associated with synaptic tagging and capture and behavioral tagging theories. However, the tag setting and recruitment of plasticity-related proteins that occur within the spatiotemporally constrained cell ensemble at the network level (cellular tagging) in the brain where multimodal sensory information is input are just beginning to be understood...
March 10, 2018: Neurobiology of Learning and Memory
Yuji Hayashino, Masatake Sugita, Hidetoshi Arima, Tetsumi Irie, Takeshi Kikuchi, Fumio Hirata
It has been found that a cyclodextrin derivative, 2-hydroxypropyl-β-cyclodextrin (HPβCD), has reasonable therapeutic effect on Niemann-Pick disease type C which is caused by abnormal accumulation of unesterified cholesterol and glycolipids in the lysosomes and shortage of esterified cholesterol in other cellular compartments. We study the binding affinity and mode of HPβCD with cholesterol in order to elucidate the possible mechanism of HPβCD for removing cholesterol from the lysosomes. The dominant binding mode of HPβCD with cholesterol is found based on the Molecular Dynamics (MD) simulation and a statistical mechanics theory of liquids, or the 3D reference interaction site model theory with Kovalenko-Hirata closure relation (3D-RISM-KH)...
March 13, 2018: Journal of Physical Chemistry. B
Marcus S Niepel, Fadi Almouhanna, Bhavya K Ekambaram, Matthias Menzel, Andreas Heilmann, Thomas Groth
BACKGROUND: Cells possess a specialized machinery through which they can sense physical as well as chemical alterations in their surrounding microenvironment that affect their cellular behavior. AIM: In this study, we aim to establish a polyelectrolyte multilayer system of 24 layers of poly-l-lysine and hyaluronic acid to control stem cell response after chemical cross-linking. METHODS AND RESULTS: The multilayer build-up process is monitored using different methods, which show that the studied polyelectrolyte multilayer system grows exponentially following the islands and islets theory...
February 1, 2018: International Journal of Artificial Organs
Hector J Rivera-Jacquez, Artëm E Masunov
Development of two-photon fluorescent probes can aid in visualizing the cellular environment. Multi-chromophore systems display complex manifolds of electronic transitions, enabling their use for optical sensing applications. Time-Dependent Density Functional Theory (TDDFT) methods allow for accurate predictions of the optical properties. These properties are related to the electronic transitions in the molecules, which include two-photon absorption cross-sections. Here we use TDDFT to understand the mechanism of aza-crown based fluorescent probes for metals sensing applications...
February 21, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Kevin Doello
Cancer tissues and placental ones share many properties such as invasiveness, metastasis and local immunosuppressive effects. The goal of the present article is to hypothesize a theory about cancer origin that links placental and cancerous tissues at molecular level. This hypothesis explain that cancer origin could be due to low hypoxic conditions in the peripheral zones of benign tumors which might up-regulate the expression of IGF2, and, consequently, trophoblastic genes. In fact, many phenotypic characteristics and molecular markers are shared between these two cell types (cancerous and trophoblastics ones), providing evidences to support this hypothesis...
April 2018: Medical Hypotheses
Daniel Suma, Aylin Acun, Pinar Zorlutuna, Dervis Can Vural
The mortality rate of many complex multicellular organisms increases with age, which suggests that net ageing damage is accumulative, despite remodelling processes. But how exactly do these little mishaps in the cellular level accumulate and spread to become a systemic catastrophe? To address this question we present experiments with synthetic tissues, an analytical model consistent with experiments, and a number of implications that follow the analytical model. Our theoretical framework describes how shape, curvature and density influences the propagation of failure in a tissue subjected to oxidative damage...
February 2018: Royal Society Open Science
Yijia Zhang, Hongfei Lin, Zhihao Yang, Jian Wang, Yiwei Liu
BACKGROUND: Recently, researchers have tried to integrate various dynamic information with static protein-protein interaction (PPI) networks to construct dynamic PPI networks. The shift from static PPI networks to dynamic PPI networks is essential to reveal the cellular function and organization. However, it is still impossible to construct an absolutely reliable dynamic PPI networks due to the noise and incompletion of high-throughput experimental data. RESULTS: To deal with uncertain data, some uncertain graph models and theories have been proposed to analyze social networks, electrical networks and biological networks...
October 16, 2017: BMC Genomics
Matthew DiSalvo, Daniel Harris, Saurin Kantesaria, Alexis N Pena, Jules D Allbritton-King, Jacqueline H Cole, Nancy L Allbritton
Polydimethylsiloxane (PDMS) membranes can act as sensing elements, barriers, and substrates, yet the low rigidity of the elastomeric membranes can limit their practical use in devices. Microraft arrays rely on a freestanding PDMS membrane as a substrate for cell arrays used in imaging cytometry and cellular isolation. However, the underlying PDMS membrane deforms under the weight of the cell media, making automated analytical microscopy (and thus cytometry and cell isolation) challenging. Here we report the development of microfabrication strategies and physically-motivated mathematical modeling of membrane deformation of PDMS microarrays...
March 6, 2018: Analytical Chemistry
Yi-Hsuan Lin, Julie D Forman-Kay, Hue Sun Chan
Liquid-liquid phase separation and related condensation processes of intrinsically disordered proteins (IDPs), proteins with intrinsically disordered regions and nucleic acids underpin various condensed-liquid droplets or gel-like assemblies in the cellular environment. Collectively referred to as condensates, these bodies provide spatial/temporal compartmentalization, often serving as hubs for regulated biomolecular interactions. Examples include certain extracellular materials, transcription complexes, and membraneless organelles such as germ and stress granules and the nucleolus...
March 6, 2018: Biochemistry
S Shekar Dukkipati, Teresa L Garrett, Sherif M Elbasiouny
Alpha-motoneuron soma size is correlated with the cell's excitability and function, and has been posited as a plastic property that changes during cellular maturation, injury, and disease. This study examined whether alpha-motoneuron somas change in size over disease progression in the G93A mouse model of amyotrophic lateral sclerosis (ALS), a disease characterized by progressive motoneuron death. We used 2D- and 3D-morphometric analysis of motoneuron size and measures of cell density at four key disease stages: Neonatal, P10 - with earliest known disease changes; young adult, P30 - presymptomatic with early motoneuron death; symptom onset, P90 - with death of 70-80% of motoneurons; and end-stage, P120+ - with full paralysis of hindlimbs...
March 4, 2018: Journal of Physiology
E Estevez-Rams, D Estevez-Moya, B Aragón-Fernández
A recently introduced model of coupled nonlinear oscillators in a ring is revisited in terms of its information processing capabilities. The use of Lempel-Ziv based entropic measures allows to study thoroughly the complex patterns appearing in the system for different values of the control parameters. Such behaviors, resembling cellular automata, have been characterized both spatially and temporally. Information distance is used to study the stability of the system to perturbations in the initial conditions and in the control parameters...
February 2018: Chaos
Kinjal Dasbiswas, Edouard Hannezo, Nir S Gov
Cell shape is determined by a balance of intrinsic properties of the cell as well as its mechanochemical environment. Inhomogeneous shape changes underlie many morphogenetic events and involve spatial gradients in active cellular forces induced by complex chemical signaling. Here, we introduce a mechanochemical model based on the notion that cell shape changes may be induced by external diffusible biomolecules that influence cellular contractility (or equivalently, adhesions) in a concentration-dependent manner-and whose spatial profile in turn is affected by cell shape...
February 27, 2018: Biophysical Journal
Ashley M Weber, Tondi M Harrison, Deborah K Steward
BACKGROUND: Oxytocin (OT), an affiliation hormone released during supportive social interactions, provides an exemplar of how social environments are reflected in our neurobiology from the beginning of life. A growing body of OT research has uncovered previously unknown functions of OT, including modulation of parenting behaviors, neuroprotection, affiliation, and bonding. Regulation theory provides a strong framework for describing how the maternal care environment affects infant neurodevelopment through a symphony of molecules that form the neurobiological milieu of the developing infant brain...
March 2018: Nursing Research
Zhichao Zhou, Yang Liu, Meng Li, Ji-Dong Gu
The deep phylogenetic topology of tree of life is in the center of a long-time dispute. The Woeseian three-domain tree theory, with the Eukarya evolving as a sister clade to Archaea, competes with the two-domain tree theory (the eocyte tree), with the Eukarya branched within Archaea. Revealed by the ongoing debate over the last three decades, sophisticated and proper phylogenetic methods should necessarily be paid with more emphasis, especially these are focusing on the compositional heterogeneity of sites and lineages, and the heterotachy issue...
February 27, 2018: Applied Microbiology and Biotechnology
Miguel López-Lázaro
All cancer registries constantly show striking differences in cancer incidence by age and among tissues. For example, lung cancer is diagnosed hundreds of times more often at age 70 than at age 20, and lung cancer in nonsmokers occurs thousands of times more frequently than heart cancer in smokers. An analysis of these differences using basic concepts in cell biology indicates that cancer is the end-result of the accumulation of cell divisions in stem cells. In other words, the main determinant of carcinogenesis is the number of cell divisions that the DNA of a stem cell has accumulated in any type of cell from the zygote...
March 2018: Critical Reviews in Oncology/hematology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"