Kupffer Cell Metabolism and Function

PubMed Central

Nguyen-Lefebvre, Anh Thu; Horuzsko, Anatolij

2015-01-01

Kupffer cells are resident liver macrophages and play a critical role in maintaining liver functions. Under physiological conditions, they are the first innate immune cells and protect the liver from bacterial infections. Under pathological conditions, they are activated by different components and can differentiate into M1-like (classical) or M2-like (alternative) macrophages. The metabolism of classical or alternative activated Kupffer cells will determine their functions in liver damage. Special functions and metabolism of Kupffer cells suggest that they are an attractive target for therapy of liver inflammation and related diseases, including cancer and infectious diseases. Here we review the different types of Kupffer cells and their metabolism and functions in physiological and pathological conditions. PMID:26937490

Be different--the diversity of peroxisomes in the animal kingdom.

PubMed

Islinger, M; Cardoso, M J R; Schrader, M

2010-08-01

Peroxisomes represent so-called "multipurpose organelles" as they contribute to various anabolic as well as catabolic pathways. Thus, with respect to the physiological specialization of an individual organ or animal species, peroxisomes exhibit a functional diversity, which is documented by significant variations in their proteome. These differences are usually regarded as an adaptational response to the nutritional and environmental life conditions of a specific organism. Thus, human peroxisomes can be regarded as an in part physiologically unique organellar entity fulfilling metabolic functions that differ from our animal model systems. In line with this, a profound understanding on how peroxisomes acquired functional heterogeneity in terms of an evolutionary and mechanistic background is required. This review summarizes our current knowledge on the heterogeneity of peroxisomal physiology, providing insights into the genetic and cell biological mechanisms, which lead to the differential localization or expression of peroxisomal proteins and further gives an overview on peroxisomal biochemical pathways, which are specialized in different animal species and organs. Moreover, it addresses the impact of proteome studies on our understanding of differential peroxisome function describing the utility of mass spectrometry and computer-assisted algorithms to identify peroxisomal target sequences for the detection of new organ- or species-specific peroxisomal proteins. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Exploratory studies of physiological components of motion sickness: Cardiopulmonary differences between high and low susceptibles

NASA Technical Reports Server (NTRS)

Naifeh, K.

1985-01-01

A comprehensive examination of cardiovascular autonomic response to motion sickness was studied and whether differences in cardiopulmonary function exist in high and low susceptibility groups were determined. Measurement techniques were developed as was test equipment for its ability to provide accurately new measures of interest and to test the adequately of these new measures in differentiating between susceptibility groups. It was concluded that these groups can be differentiated using simple, brief stressors and measurements of cardiodynamic function.

Altered physiological functions and ion currents in atrial fibroblasts from patients with chronic atrial fibrillation.

PubMed

Poulet, Claire; Künzel, Stephan; Büttner, Edgar; Lindner, Diana; Westermann, Dirk; Ravens, Ursula

2016-02-01

The contribution of human atrial fibroblasts to cardiac physiology and pathophysiology is poorly understood. Fibroblasts may contribute to arrhythmogenesis through fibrosis, or by directly altering electrical activity in cardiomyocytes. The objective of our study was to uncover phenotypic differences between cells from patients in sinus rhythm (SR) and chronic atrial fibrillation (AF), with special emphasis on electrophysiological properties. We isolated fibroblasts from human right atrial tissue for patch-clamp experiments, proliferation, migration, and differentiation assays, and gene expression profiling. In culture, proliferation and migration of AF fibroblasts were strongly impaired but differentiation into myofibroblasts was increased. This was associated with a higher number of AF fibroblasts expressing functional Nav1.5 channels. Strikingly Na(+) currents were considerably larger in AF cells. Blocking Na(+) channels in culture with tetrodotoxin did not affect proliferation, migration, or differentiation in neither SR nor AF cells. While freshly isolated fibroblasts showed mostly weak rectifier currents, fibroblasts in culture developed outward rectifier K(+) currents of similar amplitude between the SR and AF groups. Adding the K(+) channel blockers tetraethylammonium and 4-aminopyridin in culture reduced current amplitude and inhibited proliferation in the SR group only. Analysis of gene expression revealed significant differences between SR and AF in genes encoding for ion channels, collagen, growth factors, connexins, and cadherins. In conclusion, this study shows that under AF conditions atrial fibroblasts undergo phenotypic changes that are revealed in culture. Future experiments should be performed in situ to understand the nature of those changes and whether they affect cardiac electrical activity. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Improving and accelerating the differentiation and functional maturation of human stem cell-derived neurons: role of extracellular calcium and GABA.

PubMed

Kemp, Paul J; Rushton, David J; Yarova, Polina L; Schnell, Christian; Geater, Charlene; Hancock, Jane M; Wieland, Annalena; Hughes, Alis; Badder, Luned; Cope, Emma; Riccardi, Daniela; Randall, Andrew D; Brown, Jonathan T; Allen, Nicholas D; Telezhkin, Vsevolod

2016-11-15

Neurons differentiated from pluripotent stem cells using established neural culture conditions often exhibit functional deficits. Recently, we have developed enhanced media which both synchronize the neurogenesis of pluripotent stem cell-derived neural progenitors and accelerate their functional maturation; together these media are termed SynaptoJuice. This pair of media are pro-synaptogenic and generate authentic, mature synaptic networks of connected forebrain neurons from a variety of induced pluripotent and embryonic stem cell lines. Such enhanced rate and extent of synchronized maturation of pluripotent stem cell-derived neural progenitor cells generates neurons which are characterized by a relatively hyperpolarized resting membrane potential, higher spontaneous and induced action potential activity, enhanced synaptic activity, more complete development of a mature inhibitory GABA A receptor phenotype and faster production of electrical network activity when compared to standard differentiation media. This entire process - from pre-patterned neural progenitor to active neuron - takes 3 weeks or less, making it an ideal platform for drug discovery and disease modelling in the fields of human neurodegenerative and neuropsychiatric disorders, such as Huntington's disease, Parkinson's disease, Alzheimer's disease and Schizophrenia. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Regulation of mitochondrial function and endoplasmic reticulum stress by nitric oxide in pluripotent stem cells

PubMed Central

Caballano-Infantes, Estefania; Terron-Bautista, José; Beltrán-Povea, Amparo; Cahuana, Gladys M; Soria, Bernat; Nabil, Hajji; Bedoya, Francisco J; Tejedo, Juan R

2017-01-01

Mitochondrial dysfunction and endoplasmic reticulum stress (ERS) are global processes that are interrelated and regulated by several stress factors. Nitric oxide (NO) is a multifunctional biomolecule with many varieties of physiological and pathological functions, such as the regulation of cytochrome c inhibition and activation of the immune response, ERS and DNA damage; these actions are dose-dependent. It has been reported that in embryonic stem cells, NO has a dual role, controlling differentiation, survival and pluripotency, but the molecular mechanisms by which it modulates these functions are not yet known. Low levels of NO maintain pluripotency and induce mitochondrial biogenesis. It is well established that NO disrupts the mitochondrial respiratory chain and causes changes in mitochondrial Ca2+ flux that induce ERS. Thus, at high concentrations, NO becomes a potential differentiation agent due to the relationship between ERS and the unfolded protein response in many differentiated cell lines. Nevertheless, many studies have demonstrated the need for physiological levels of NO for a proper ERS response. In this review, we stress the importance of the relationships between NO levels, ERS and mitochondrial dysfunction that control stem cell fate as a new approach to possible cell therapy strategies. PMID:28289506

Regulation of mitochondrial function and endoplasmic reticulum stress by nitric oxide in pluripotent stem cells.

PubMed

Caballano-Infantes, Estefania; Terron-Bautista, José; Beltrán-Povea, Amparo; Cahuana, Gladys M; Soria, Bernat; Nabil, Hajji; Bedoya, Francisco J; Tejedo, Juan R

2017-02-26

Mitochondrial dysfunction and endoplasmic reticulum stress (ERS) are global processes that are interrelated and regulated by several stress factors. Nitric oxide (NO) is a multifunctional biomolecule with many varieties of physiological and pathological functions, such as the regulation of cytochrome c inhibition and activation of the immune response, ERS and DNA damage; these actions are dose-dependent. It has been reported that in embryonic stem cells, NO has a dual role, controlling differentiation, survival and pluripotency, but the molecular mechanisms by which it modulates these functions are not yet known. Low levels of NO maintain pluripotency and induce mitochondrial biogenesis. It is well established that NO disrupts the mitochondrial respiratory chain and causes changes in mitochondrial Ca 2+ flux that induce ERS. Thus, at high concentrations, NO becomes a potential differentiation agent due to the relationship between ERS and the unfolded protein response in many differentiated cell lines. Nevertheless, many studies have demonstrated the need for physiological levels of NO for a proper ERS response. In this review, we stress the importance of the relationships between NO levels, ERS and mitochondrial dysfunction that control stem cell fate as a new approach to possible cell therapy strategies.

Neural control of the kidney: functionally specific renal sympathetic nerve fibers.

PubMed

DiBona, G F

2000-11-01

The sympathetic nervous system provides differentiated regulation of the functions of various organs. This differentiated regulation occurs via mechanisms that operate at multiple sites within the classic reflex arc: peripherally at the level of afferent input stimuli to various reflex pathways, centrally at the level of interconnections between various central neuron pools, and peripherally at the level of efferent fibers targeted to various effectors within the organ. In the kidney, increased renal sympathetic nerve activity regulates the functions of the intrarenal effectors: the tubules, the blood vessels, and the juxtaglomerular granular cells. This enables a physiologically appropriate coordination between the circulatory, filtration, reabsorptive, excretory, and renin secretory contributions to overall renal function. Anatomically, each of these effectors has a dual pattern of innervation consisting of a specific and selective innervation by unmyelinated slowly conducting C-type renal sympathetic nerve fibers in addition to an innervation that is shared among all the effectors. This arrangement permits the maximum flexibility in the coordination of physiologically appropriate responses of the tubules, the blood vessels, and the juxtaglomerular granular cells to a variety of homeostatic requirements.

Functionally specific renal sympathetic nerve fibers: role in cardiovascular regulation.

PubMed

DiBona, G F

2001-06-01

The sympathetic nervous system provides differentiated regulation of the functions of various organs. This differentiated regulation occurs through mechanisms that operate at multiple sites within the classic reflex arc: peripherally at the level of afferent input stimuli to various reflex pathways, centrally at the level of interconnections between various central neuron pools, and peripherally at the level of efferent fibers targeted to various effectors within the organ. In the kidney, increased renal sympathetic nerve activity regulates the functions of the intrarenal effectors: the tubules, the blood vessels, and the juxtaglomerular granular cells. This enables a physiologically appropriate coordination between the circulatory, filtration, reabsorptive, excretory, and renin secretory contributions to overall renal function. Anatomically, each of these effectors has a dual pattern of innervation consisting of a specific and selective innervation by unmyelinated slowly conducting C-type renal sympathetic nerve fibers and an innervation that is shared among all the effectors. This arrangement facilitates maximum flexibility in the coordination of the tubules, the blood vessels, and the juxtaglomerular granular cells so as to produce physiologically appropriate responses to a variety of homeostatic requirements.

Differential and Conditional Activation of PKC-Isoforms Dictates Cardiac Adaptation during Physiological to Pathological Hypertrophy

PubMed Central

Naskar, Shaon; Datta, Kaberi; Mitra, Arkadeep; Pathak, Kanchan; Datta, Ritwik; Bansal, Trisha; Sarkar, Sagartirtha

2014-01-01

A cardiac hypertrophy is defined as an increase in heart mass which may either be beneficial (physiological hypertrophy) or detrimental (pathological hypertrophy). This study was undertaken to establish the role of different protein kinase-C (PKC) isoforms in the regulation of cardiac adaptation during two types of cardiac hypertrophy. Phosphorylation of specific PKC-isoforms and expression of their downstream proteins were studied during physiological and pathological hypertrophy in 24 week male Balb/c mice (Mus musculus) models, by reverse transcriptase-PCR, western blot analysis and M-mode echocardiography for cardiac function analysis. PKC-δ was significantly induced during pathological hypertrophy while PKC-α was exclusively activated during physiological hypertrophy in our study. PKC-δ activation during pathological hypertrophy resulted in cardiomyocyte apoptosis leading to compromised cardiac function and on the other hand, activation of PKC-α during physiological hypertrophy promoted cardiomyocyte growth but down regulated cellular apoptotic load resulting in improved cardiac function. Reversal in PKC-isoform with induced activation of PKC-δ and simultaneous inhibition of phospho-PKC-α resulted in an efficient myocardium to deteriorate considerably resulting in compromised cardiac function during physiological hypertrophy via augmentation of apoptotic and fibrotic load. This is the first report where PKC-α and -δ have been shown to play crucial role in cardiac adaptation during physiological and pathological hypertrophy respectively thereby rendering compromised cardiac function to an otherwise efficient heart by conditional reversal of their activation. PMID:25116170

Effects of Hypogravity on Osteoblast Differentiation

NASA Technical Reports Server (NTRS)

Globus, Ruth; Doty, Steven

1997-01-01

Weightbearing is essential for normal skeletal function. Without weightbearing, the rate of bone formation by osteoblasts decreases in the growing rat. Defective formation may account for the decrease in the maturation, strength and mass of bone that is caused by spaceflight. These skeletal defects may be mediated by a combination of physiologic changes triggered by spaceflight, including skeletal unloading, fluid shifts, and stress-induced endocrine factors. The fundamental question of whether the defects in osteoblast function due to weightlessness are mediated by localized skeletal unloading or by systemic physiologic adaptations such as fluid shifts has not been answered. Furthermore, bone-forming activity of osteoblasts during unloading may be affected by paracrine signals from vascular, monocytic, and neural cells that also reside in skeletal tissue. Therefore we proposed to examine whether exposure of cultured rat osteoblasts to spaceflight inhibits cellular differentiation and impairs mineralization when isolated from the influence of both systemic factors and other skeletal cells.

From Inverse Problems in Mathematical Physiology to Quantitative Differential Diagnoses

PubMed Central

Zenker, Sven; Rubin, Jonathan; Clermont, Gilles

2007-01-01

The improved capacity to acquire quantitative data in a clinical setting has generally failed to improve outcomes in acutely ill patients, suggesting a need for advances in computer-supported data interpretation and decision making. In particular, the application of mathematical models of experimentally elucidated physiological mechanisms could augment the interpretation of quantitative, patient-specific information and help to better target therapy. Yet, such models are typically complex and nonlinear, a reality that often precludes the identification of unique parameters and states of the model that best represent available data. Hypothesizing that this non-uniqueness can convey useful information, we implemented a simplified simulation of a common differential diagnostic process (hypotension in an acute care setting), using a combination of a mathematical model of the cardiovascular system, a stochastic measurement model, and Bayesian inference techniques to quantify parameter and state uncertainty. The output of this procedure is a probability density function on the space of model parameters and initial conditions for a particular patient, based on prior population information together with patient-specific clinical observations. We show that multimodal posterior probability density functions arise naturally, even when unimodal and uninformative priors are used. The peaks of these densities correspond to clinically relevant differential diagnoses and can, in the simplified simulation setting, be constrained to a single diagnosis by assimilating additional observations from dynamical interventions (e.g., fluid challenge). We conclude that the ill-posedness of the inverse problem in quantitative physiology is not merely a technical obstacle, but rather reflects clinical reality and, when addressed adequately in the solution process, provides a novel link between mathematically described physiological knowledge and the clinical concept of differential diagnoses. We outline possible steps toward translating this computational approach to the bedside, to supplement today's evidence-based medicine with a quantitatively founded model-based medicine that integrates mechanistic knowledge with patient-specific information. PMID:17997590

Physiologically based microenvironment for in vitro neural differentiation of adipose-derived stem cells.

PubMed

Graziano, Adriana Carol Eleonora; Avola, Rosanna; Perciavalle, Vincenzo; Nicoletti, Ferdinando; Cicala, Gianluca; Coco, Marinella; Cardile, Venera

2018-03-26

The limited capacity of nervous system to promote a spontaneous regeneration and the high rate of neurodegenerative diseases appearance are keys factors that stimulate researches both for defining the molecular mechanisms of pathophysiology and for evaluating putative strategies to induce neural tissue regeneration. In this latter aspect, the application of stem cells seems to be a promising approach, even if the control of their differentiation and the maintaining of a safe state of proliferation should be troubled. Here, we focus on adipose tissue-derived stem cells and we seek out the recent advances on the promotion of their neural differentiation, performing a critical integration of the basic biology and physiology of adipose tissue-derived stem cells with the functional modifications that the biophysical, biomechanical and biochemical microenvironment induces to cell phenotype. The pre-clinical studies showed that the neural differentiation by cell stimulation with growth factors benefits from the integration with biomaterials and biophysical interaction like microgravity. All these elements have been reported as furnisher of microenvironments with desirable biological, physical and mechanical properties. A critical review of current knowledge is here proposed, underscoring that a real advance toward a stable, safe and controllable adipose stem cells clinical application will derive from a synergic multidisciplinary approach that involves material engineer, basic cell biology, cell and tissue physiology.

Retained differentiation capacity of human skeletal muscle satellite cells from spinal cord-injured individuals.

PubMed

Savikj, Mladen; Ruby, Maxwell A; Kostovski, Emil; Iversen, Per O; Zierath, Juleen R; Krook, Anna; Widegren, Ulrika

2018-06-01

Despite the well-known role of satellite cells in skeletal muscle plasticity, the effect of spinal cord injury on their function in humans remains unknown. We determined whether spinal cord injury affects the intrinsic ability of satellite cells to differentiate and produce metabolically healthy myotubes. We obtained vastus lateralis biopsies from eight spinal cord-injured and six able-bodied individuals. Satellite cells were isolated, grown and differentiated in vitro. Gene expression was measured by quantitative PCR. Abundance of differentiation markers and regulatory proteins was determined by Western blotting. Protein synthesis and fatty acid oxidation were measured by radioactive tracer-based assays. Activated satellite cells (myoblasts) and differentiated myotubes derived from skeletal muscle of able-bodied and spinal cord-injured individuals expressed similar (P > 0.05) mRNA levels of myogenic regulatory factors. Myogenic differentiation factor 1 expression was higher in myoblasts from spinal cord-injured individuals. Desmin and myogenin protein content was increased upon differentiation in both groups, while myotubes from spinal cord-injured individuals contained more type I and II myosin heavy chain. Phosphorylated and total protein levels of Akt-mechanistic target of rapamycin and forkhead box protein O signalling axes and protein synthesis rate in myotubes were similar (P > 0.05) between groups. Additionally, fatty acid oxidation of myotubes from spinal cord-injured individuals was unchanged (P > 0.05) compared to able-bodied controls. Our results indicate that the intrinsic differentiation capacity of satellite cells and metabolic characteristics of myotubes are preserved following spinal cord injury. This may inform potential interventions targeting satellite cell activation to alleviate skeletal muscle atrophy. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Stress Physiology in Infancy and Early Childhood: Cortisol Flexibility, Attunement and Coordination.

PubMed

Atkinson, L; Jamieson, B; Khoury, J; Ludmer, J; Gonzalez, A

2016-08-01

Research on stress physiology in infancy has assumed increasing importance due to its lifelong implications. In this review, we focus on measurement of hypothalamic-pituitary-adrenal (HPA) function, in particular, and on complementary autonomic processes. We suggest that the measure of HPA function has been overly exclusive, focusing on individual reactivity to single, pragmatically selected laboratory challenges. We advocate use of multiple, strategically chosen challenges and within-subject designs. By administering one challenge that typically does not provoke reactivity and another that does, it is possible to represent allostatic load in terms of "flexibility," the capacity to titrate response to challenge. We also recommend assessing infant reactivity in the context of the primary caregiver's physiological function. Infant-mother "attunement" is central to developmental psychology, permeating diverse developmental domains with varied consequences. A review of adrenocortical attunement suggests that attunement is a reliable process, manifest across varied populations. However, attunement appears stronger in the context of more highly stressful circumstances, such that administration of multiple, selected challenges may help evaluate the degree to which individuals titrate attunement to challenge and determine the correlates of this differential attunement. Finally, we advocate studying the "coordination" of HPA function with other aspects of stress physiology and variation in the degree of this coordination. The use of multiple stressors is important here because each stress system is differentially sensitive to different types of challenge. Therefore, use of single stressors in between-subject designs impedes full recognition of the role played by each system. Overall, we recommend measure of flexibility, attunement, and coordination in the context of multiple challenges to capture allostasis in environmental and physiological context. The simultaneous use of such inclusive and integrative metrics may yield more reliable findings than has hitherto been the case. The interrelation of these metrics can be understood in the context of the adaptive calibration model.. © 2016 British Society for Neuroendocrinology.

When galectins recognize glycans: from biochemistry to physiology and back again.

PubMed

Di Lella, Santiago; Sundblad, Victoria; Cerliani, Juan P; Guardia, Carlos M; Estrin, Dario A; Vasta, Gerardo R; Rabinovich, Gabriel A

2011-09-20

In the past decade, increasing efforts have been devoted to the study of galectins, a family of evolutionarily conserved glycan-binding proteins with multifunctional properties. Galectins function, either intracellularly or extracellularly, as key biological mediators capable of monitoring changes occurring on the cell surface during fundamental biological processes such as cellular communication, inflammation, development, and differentiation. Their highly conserved structures, exquisite carbohydrate specificity, and ability to modulate a broad spectrum of biological processes have captivated a wide range of scientists from a wide spectrum of disciplines, including biochemistry, biophysics, cell biology, and physiology. However, in spite of enormous efforts to dissect the functions and properties of these glycan-binding proteins, limited information about how structural and biochemical aspects of these proteins can influence biological functions is available. In this review, we aim to integrate structural, biochemical, and functional aspects of this bewildering and ancient family of glycan-binding proteins and discuss their implications in physiologic and pathologic settings. © 2011 American Chemical Society

TSH Receptor Function Is Required for Normal Thyroid Differentiation in Zebrafish

PubMed Central

Opitz, Robert; Maquet, Emilie; Zoenen, Maxime; Dadhich, Rajesh

2011-01-01

TSH is the primary physiological regulator of thyroid gland function. The effects of TSH on thyroid cells are mediated via activation of its membrane receptor [TSH receptor (TSHR)]. In this study, we examined functional thyroid differentiation in zebrafish and characterized the role of TSHR signaling during thyroid organogenesis. Cloning of a cDNA encoding zebrafish Tshr showed conservation of primary structure and functional properties between zebrafish and mammalian TSHR. In situ hybridization confirmed that the thyroid is the major site of tshr expression during zebrafish development. In addition, we identified tpo, iyd, duox, and duoxa as novel thyroid differentiation markers in zebrafish. Temporal analyses of differentiation marker expression demonstrated the induction of an early thyroid differentiation program along with thyroid budding, followed by a delayed onset of duox and duoxa expression coincident with thyroid hormone synthesis. Furthermore, comparative analyses in mouse and zebrafish revealed for the first time a thyroid-enriched expression of cell death regulators of the B-cell lymphoma 2 family during early thyroid morphogenesis. Knockdown of tshr function by morpholino microinjection into embryos did not affect early thyroid morphogenesis but caused defects in later functional differentiation. The thyroid phenotype observed in tshr morphants at later stages comprised a reduction in number and size of functional follicles, down-regulation of differentiation markers, as well as reduced thyroid transcription factor expression. A comparison of our results with phenotypes observed in mouse models of defective TSHR and cAMP signaling highlights the value of zebrafish as a model to enhance the understanding of functional differentiation in the vertebrate thyroid. PMID:21737742

Midi-maxi computer interaction in the interpretation of nuclear medicine procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schlapper, G.A.

1977-01-01

A study of renal function with an Anger Gamma Camera coupled with a Digital Equipment Corporation Gamma-11 System and an IBM System 370 demonstrates the potential of quantitative determinations of physiological function through the application of midi-maxi computer interaction in the interpretation of nuclear medicine procedures. It is shown that radiotracers can provide an opportunity to assess physiological processes of renal function by noninvasively following the path of a tracer as a function of time. Time-activity relationships obtained over seven anatomically defined regions are related to parameters of a seven compartment model employed to describe the renal clearance process. Themore » values obtained for clinically significant parameters agree with known renal pathophysiology. Differentiation of failure of acute, chronic, and obstructive forms is indicated.« less

Unraveling Synaptic GCaMP Signals: Differential Excitability and Clearance Mechanisms Underlying Distinct Ca2+ Dynamics in Tonic and Phasic Excitatory, and Aminergic Modulatory Motor Terminals in Drosophila

PubMed Central

Xing, Xiaomin

2018-01-01

Abstract GCaMP is an optogenetic Ca2+ sensor widely used for monitoring neuronal activities but the precise physiological implications of GCaMP signals remain to be further delineated among functionally distinct synapses. The Drosophila neuromuscular junction (NMJ), a powerful genetic system for studying synaptic function and plasticity, consists of tonic and phasic glutamatergic and modulatory aminergic motor terminals of distinct properties. We report a first simultaneous imaging and electric recording study to directly contrast the frequency characteristics of GCaMP signals of the three synapses for physiological implications. Different GCaMP variants were applied in genetic and pharmacological perturbation experiments to examine the Ca2+ influx and clearance processes underlying the GCaMP signal. Distinct mutational and drug effects on GCaMP signals indicate differential roles of Na+ and K+ channels, encoded by genes including paralytic (para), Shaker (Sh), Shab, and ether-a-go-go (eag), in excitability control of different motor terminals. Moreover, the Ca2+ handling properties reflected by the characteristic frequency dependence of the synaptic GCaMP signals were determined to a large extent by differential capacity of mitochondria-powered Ca2+ clearance mechanisms. Simultaneous focal recordings of synaptic activities further revealed that GCaMPs were ineffective in tracking the rapid dynamics of Ca2+ influx that triggers transmitter release, especially during low-frequency activities, but more adequately reflected cytosolic residual Ca2+ accumulation, a major factor governing activity-dependent synaptic plasticity. These results highlight the vast range of GCaMP response patterns in functionally distinct synaptic types and provide relevant information for establishing basic guidelines for the physiological interpretations of presynaptic GCaMP signals from in situ imaging studies. PMID:29464198

The western painted turtle genome, a model for the evolution of extreme physiological adaptations in a slowly evolving lineage

PubMed Central

2013-01-01

Background We describe the genome of the western painted turtle, Chrysemys picta bellii, one of the most widespread, abundant, and well-studied turtles. We place the genome into a comparative evolutionary context, and focus on genomic features associated with tooth loss, immune function, longevity, sex differentiation and determination, and the species' physiological capacities to withstand extreme anoxia and tissue freezing. Results Our phylogenetic analyses confirm that turtles are the sister group to living archosaurs, and demonstrate an extraordinarily slow rate of sequence evolution in the painted turtle. The ability of the painted turtle to withstand complete anoxia and partial freezing appears to be associated with common vertebrate gene networks, and we identify candidate genes for future functional analyses. Tooth loss shares a common pattern of pseudogenization and degradation of tooth-specific genes with birds, although the rate of accumulation of mutations is much slower in the painted turtle. Genes associated with sex differentiation generally reflect phylogeny rather than convergence in sex determination functionality. Among gene families that demonstrate exceptional expansions or show signatures of strong natural selection, immune function and musculoskeletal patterning genes are consistently over-represented. Conclusions Our comparative genomic analyses indicate that common vertebrate regulatory networks, some of which have analogs in human diseases, are often involved in the western painted turtle's extraordinary physiological capacities. As these regulatory pathways are analyzed at the functional level, the painted turtle may offer important insights into the management of a number of human health disorders. PMID:23537068

[Recent studies on corneal epithelial barrier function].

PubMed

Liu, F F; Li, W; Liu, Z G; Chen, W S

2016-08-01

Corneal epithelium, the outermost layer of eyeball, is the main route for foreign materials to enter the eye. Under physiological conditions, the corneal epithelial superficial cells form a functionally selective permeability barrier. Integral corneal epithelial barrier function not only ensures the enrolling of nutrients which is required for regular metabolism, but also prevents foreign bodies, or disease-causing microorganism invasion. Recently, a large number of clinical and experimental studies have shown that abnormal corneal epithelial barrier function is the pathological basis for many ocular diseases. In addition, some study found that corneal epithelial barrier constitutes a variety of proteins involved in cell proliferation, differentiation, apoptosis, and a series of physiological and pathological processes. This paper reviewed recent studies specifically on the corneal epithelial barrier, highlights of its structure, function and influence factors. (Chin J Ophthalmol, 2016, 52: 631-635).

Macromolecular crowding meets oxygen tension in human mesenchymal stem cell culture - A step closer to physiologically relevant in vitro organogenesis

NASA Astrophysics Data System (ADS)

Cigognini, Daniela; Gaspar, Diana; Kumar, Pramod; Satyam, Abhigyan; Alagesan, Senthilkumar; Sanz-Nogués, Clara; Griffin, Matthew; O'Brien, Timothy; Pandit, Abhay; Zeugolis, Dimitrios I.

2016-08-01

Modular tissue engineering is based on the cells’ innate ability to create bottom-up supramolecular assemblies with efficiency and efficacy still unmatched by man-made devices. Although the regenerative potential of such tissue substitutes has been documented in preclinical and clinical setting, the prolonged culture time required to develop an implantable device is associated with phenotypic drift and/or cell senescence. Herein, we demonstrate that macromolecular crowding significantly enhances extracellular matrix deposition in human bone marrow mesenchymal stem cell culture at both 20% and 2% oxygen tension. Although hypoxia inducible factor - 1α was activated at 2% oxygen tension, increased extracellular matrix synthesis was not observed. The expression of surface markers and transcription factors was not affected as a function of oxygen tension and macromolecular crowding. The multilineage potential was also maintained, albeit adipogenic differentiation was significantly reduced in low oxygen tension cultures, chondrogenic differentiation was significantly increased in macromolecularly crowded cultures and osteogenic differentiation was not affected as a function of oxygen tension and macromolecular crowding. Collectively, these data pave the way for the development of bottom-up tissue equivalents based on physiologically relevant developmental processes.

Macromolecular crowding meets oxygen tension in human mesenchymal stem cell culture - A step closer to physiologically relevant in vitro organogenesis

PubMed Central

Cigognini, Daniela; Gaspar, Diana; Kumar, Pramod; Satyam, Abhigyan; Alagesan, Senthilkumar; Sanz-Nogués, Clara; Griffin, Matthew; O’Brien, Timothy; Pandit, Abhay; Zeugolis, Dimitrios I.

2016-01-01

Modular tissue engineering is based on the cells’ innate ability to create bottom-up supramolecular assemblies with efficiency and efficacy still unmatched by man-made devices. Although the regenerative potential of such tissue substitutes has been documented in preclinical and clinical setting, the prolonged culture time required to develop an implantable device is associated with phenotypic drift and/or cell senescence. Herein, we demonstrate that macromolecular crowding significantly enhances extracellular matrix deposition in human bone marrow mesenchymal stem cell culture at both 20% and 2% oxygen tension. Although hypoxia inducible factor - 1α was activated at 2% oxygen tension, increased extracellular matrix synthesis was not observed. The expression of surface markers and transcription factors was not affected as a function of oxygen tension and macromolecular crowding. The multilineage potential was also maintained, albeit adipogenic differentiation was significantly reduced in low oxygen tension cultures, chondrogenic differentiation was significantly increased in macromolecularly crowded cultures and osteogenic differentiation was not affected as a function of oxygen tension and macromolecular crowding. Collectively, these data pave the way for the development of bottom-up tissue equivalents based on physiologically relevant developmental processes. PMID:27478033

The Emergence of Physiology and Form: Natural Selection Revisited

PubMed Central

Torday, John S.

2016-01-01

Natural Selection describes how species have evolved differentially, but it is descriptive, non-mechanistic. What mechanisms does Nature use to accomplish this feat? One known way in which ancient natural forces affect development, phylogeny and physiology is through gravitational effects that have evolved as mechanotransduction, seen in the lung, kidney and bone, linking as molecular homologies to skin and brain. Tracing the ontogenetic and phylogenetic changes that have facilitated mechanotransduction identifies specific homologous cell-types and functional molecular markers for lung homeostasis that reveal how and why complex physiologic traits have evolved from the unicellular to the multicellular state. Such data are reinforced by their reverse-evolutionary patterns in chronic degenerative diseases. The physiologic responses of model organisms like Dictyostelium and yeast to gravity provide deep comparative molecular phenotypic homologies, revealing mammalian Target of Rapamycin (mTOR) as the final common pathway for vertical integration of vertebrate physiologic evolution; mTOR integrates calcium/lipid epistatic balance as both the proximate and ultimate positive selection pressure for vertebrate physiologic evolution. The commonality of all vertebrate structure-function relationships can be reduced to calcium/lipid homeostatic regulation as the fractal unit of vertebrate physiology, demonstrating the primacy of the unicellular state as the fundament of physiologic evolution. PMID:27534726

Mechanism-based testing strategy using in vitro approaches for identification of thyroid hormone disrupting chemicals

EPA Science Inventory

The thyroid hormone (TH) system is involved in several important physiological processes, including regulation of energy metabolism, growth and differentiation, development and maintenance of brain function, thermo-regulation, osmo-regulation, and axis of regulation of other endo...

Gene Duplication and Evolutionary Innovations in Hemoglobin-Oxygen Transport

PubMed Central

2016-01-01

During vertebrate evolution, duplicated hemoglobin (Hb) genes diverged with respect to functional properties as well as the developmental timing of expression. For example, the subfamilies of genes that encode the different subunit chains of Hb are ontogenetically regulated such that functionally distinct Hb isoforms are expressed during different developmental stages. In some vertebrate taxa, functional differentiation between co-expressed Hb isoforms may also contribute to physiologically important divisions of labor. PMID:27053736

Deleterious effects of tributyltin on porcine vascular stem cells physiology.

PubMed

Bernardini, Chiara; Zannoni, Augusta; Bertocchi, Martina; Bianchi, Francesca; Salaroli, Roberta; Botelho, Giuliana; Bacci, Maria Laura; Ventrella, Vittoria; Forni, Monica

2016-01-01

The vascular functional and structural integrity is essential for the maintenance of the whole organism and it has been demonstrated that different types of vascular progenitor cells resident in the vessel wall play an important role in this process. The purpose of the present research was to observe the effect of tributyltin (TBT), a risk factor for vascular disorders, on porcine Aortic Vascular Precursor Cells (pAVPCs) in term of cytotoxicity, gene expression profile, functionality and differentiation potential. We have demonstrated that pAVPCs morphology deeply changed following TBT treatment. After 48h a cytotoxic effect has been detected and Annexin binding assay demonstrated that TBT induced apoptosis. The transcriptional profile of characteristic pericyte markers has been altered: TBT 10nM substantially induced alpha-SMA, while, TBT 500nM determined a significant reduction of all pericyte markers. IL-6 protein detected in the medium of pAVPCs treated with TBT at both doses studied and with a dose response. TBT has interfered with normal pAVPC functionality preventing their ability to support a capillary-like network. In addition TBT has determined an increase of pAVPC adipogenic differentiation. In conclusion in the present paper we have demonstrated that TBT alters the vascular stem cells in terms of structure, functionality and differentiating capability, therefore effects of TBT in blood should be deeply explored to understand the potential vascular risk associated with the alteration of vascular stem cell physiology. Copyright © 2016 Elsevier Inc. All rights reserved.

Rad GTPase is essential for the regulation of bone density and bone marrow adipose tissue in mice.

PubMed

Withers, Catherine N; Brown, Drew M; Byiringiro, Innocent; Allen, Matthew R; Condon, Keith W; Satin, Jonathan; Andres, Douglas A

2017-10-01

The small GTP-binding protein Rad (RRAD, Ras associated with diabetes) is the founding member of the RGK (Rad, Rem, Rem2, and Gem/Kir) family that regulates cardiac voltage-gated Ca 2+ channel function. However, its cellular and physiological functions outside of the heart remain to be elucidated. Here we report that Rad GTPase function is required for normal bone homeostasis in mice, as Rad deletion results in significantly lower bone mass and higher bone marrow adipose tissue (BMAT) levels. Dynamic histomorphometry in vivo and primary calvarial osteoblast assays in vitro demonstrate that bone formation and osteoblast mineralization rates are depressed, while in vitro osteoclast differentiation is increased, in the absence of Rad. Microarray analysis revealed that canonical osteogenic gene expression (Runx2, osterix, etc.) is not altered in Rad -/- calvarial osteoblasts; instead robust up-regulation of matrix Gla protein (MGP, +11-fold), an inhibitor of extracellular matrix mineralization and a protein secreted during adipocyte differentiation, was observed. Strikingly, Rad deficiency also resulted in significantly higher marrow adipose tissue levels in vivo and promoted spontaneous in vitro adipogenesis of primary calvarial osteoblasts. Adipogenic differentiation of wildtype calvarial osteoblasts resulted in the loss of endogenous Rad protein, further supporting a role for Rad in the control of BMAT levels. These findings reveal a novel in vivo function for Rad and establish a role for Rad signaling in the complex physiological control of skeletal homeostasis and bone marrow adiposity. Copyright © 2017 Elsevier Inc. All rights reserved.

Tissue Doppler Imaging can be useful to distinguish pathological from physiological left ventricular hypertrophy: a study in master athletes and mild hypertensive subjects

PubMed Central

Galanti, Giorgio; Toncelli, Loira; Del Furia, Francesca; Stefani, Laura; Cappelli, Brunello; De Luca, Alessio; Vono, Maria Concetta Roberta

2009-01-01

Background Transthoracic echocardiography left ventricular wall thickness is often increased in master athletes and it results by intense physical training. Left Ventricular Hypertrophy can also be due to a constant pressure overload. Conventional Pulsed Wave (PW) Doppler analysis of diastolic function sometimes fails to distinguish physiological from pathological LVH. The aim of this study is to evaluate the role of Pulsed Wave Tissue Doppler Imaging in differentiating pathological from physiological LVH in the middle-aged population. Methods we selected a group of 80 master athletes, a group of 80 sedentary subjects with essential hypertension and an apparent normal diastolic function at standard PW Doppler analysis. The two groups were comparable for increased left ventricular wall thickness and mass index (134.4 ± 19.7 vs 134.5 ± 22.1 gr/m2; p > .05). Diastolic function indexes using the PW technique were in the normal range for both. Results Pulsed Wave TDI study of diastolic function immediately distinguished the two groups. While in master athletes the diastolic TDI-derived parameters remained within normal range (E' 9.4 ± 3.1 cm/sec; E/E' 7.8 ± 2.1), in the hypertensive group these parameters were found to be constantly altered, with mean values and variation ranges always outside normal validated limits (E' 7.2 ± 2.4 cm/sec; E/E' 10.6 ± 3.2), and with E' and E/E' statistically different in the two groups (p < .001). Conclusion Our study showed that the TDI technique can be an easy and validated method to assess diastolic function in differentiating normal from pseudonormal diastolic patterns and it can distinguish physiological from pathological LVH emphasizing the eligibility certification required by legal medical legislation as in Italy. PMID:19845938

GSK3 as a Sensor Determining Cell Fate in the Brain.

PubMed

Cole, Adam R

2012-01-01

Glycogen synthase kinase 3 (GSK3) is an unusual serine/threonine kinase that controls many neuronal functions, including neurite outgrowth, synapse formation, neurotransmission, and neurogenesis. It mediates these functions by phosphorylating a wide range of substrates involved in gene transcription, metabolism, apoptosis, cytoskeletal dynamics, signal transduction, lipid membrane dynamics, and trafficking, amongst others. This complicated list of diverse substrates generally follow a more simple pattern: substrates negatively regulated by GSK3-mediated phosphorylation favor a proliferative/survival state, while substrates positively regulated by GSK3 favor a more differentiated/functional state. Accordingly, GSK3 activity is higher in differentiated cells than undifferentiated cells and physiological (Wnt, growth factors) and pharmacological inhibitors of GSK3 promote the proliferative capacity of embryonic stem cells. In the brain, the level of GSK3 activity influences neural progenitor cell proliferation/differentiation in neuroplasticity and repair, as well as efficient neurotransmission in differentiated adult neurons. While defects in GSK3 activity are unlikely to be the primary cause of neurodegenerative diseases, therapeutic regulation of its activity to promote a proliferative/survival versus differentiated/mature functional environment in the brain could be a powerful strategy for treatment of neurodegenerative and other mental disorders.

GSK3 as a Sensor Determining Cell Fate in the Brain

PubMed Central

Cole, Adam R.

2012-01-01

Glycogen synthase kinase 3 (GSK3) is an unusual serine/threonine kinase that controls many neuronal functions, including neurite outgrowth, synapse formation, neurotransmission, and neurogenesis. It mediates these functions by phosphorylating a wide range of substrates involved in gene transcription, metabolism, apoptosis, cytoskeletal dynamics, signal transduction, lipid membrane dynamics, and trafficking, amongst others. This complicated list of diverse substrates generally follow a more simple pattern: substrates negatively regulated by GSK3-mediated phosphorylation favor a proliferative/survival state, while substrates positively regulated by GSK3 favor a more differentiated/functional state. Accordingly, GSK3 activity is higher in differentiated cells than undifferentiated cells and physiological (Wnt, growth factors) and pharmacological inhibitors of GSK3 promote the proliferative capacity of embryonic stem cells. In the brain, the level of GSK3 activity influences neural progenitor cell proliferation/differentiation in neuroplasticity and repair, as well as efficient neurotransmission in differentiated adult neurons. While defects in GSK3 activity are unlikely to be the primary cause of neurodegenerative diseases, therapeutic regulation of its activity to promote a proliferative/survival versus differentiated/mature functional environment in the brain could be a powerful strategy for treatment of neurodegenerative and other mental disorders. PMID:22363258

Physiologically based microenvironment for in vitro neural differentiation of adipose-derived stem cells

PubMed Central

Graziano, Adriana Carol Eleonora; Avola, Rosanna; Perciavalle, Vincenzo; Nicoletti, Ferdinando; Cicala, Gianluca; Coco, Marinella; Cardile, Venera

2018-01-01

The limited capacity of nervous system to promote a spontaneous regeneration and the high rate of neurodegenerative diseases appearance are keys factors that stimulate researches both for defining the molecular mechanisms of pathophysiology and for evaluating putative strategies to induce neural tissue regeneration. In this latter aspect, the application of stem cells seems to be a promising approach, even if the control of their differentiation and the maintaining of a safe state of proliferation should be troubled. Here, we focus on adipose tissue-derived stem cells and we seek out the recent advances on the promotion of their neural differentiation, performing a critical integration of the basic biology and physiology of adipose tissue-derived stem cells with the functional modifications that the biophysical, biomechanical and biochemical microenvironment induces to cell phenotype. The pre-clinical studies showed that the neural differentiation by cell stimulation with growth factors benefits from the integration with biomaterials and biophysical interaction like microgravity. All these elements have been reported as furnisher of microenvironments with desirable biological, physical and mechanical properties. A critical review of current knowledge is here proposed, underscoring that a real advance toward a stable, safe and controllable adipose stem cells clinical application will derive from a synergic multidisciplinary approach that involves material engineer, basic cell biology, cell and tissue physiology. PMID:29588808

Transcriptome Profile at Different Physiological Stages Reveals Potential Mode for Curly Fleece in Chinese Tan Sheep

PubMed Central

Liu, Yufang; Xu, Qinqin; Zhang, Ming; Fang, Meiying

2013-01-01

Tan sheep (Ovis aries), a Chinese indigenous breed, has special curly fleece after birth, especially at one month old. However, this unique phenotype disappears gradually with age and the underlying reasons of trait evolvement are still unknown. In this study, skin transcriptome data was used to study this issue. In total 51,215 transcripts including described transcripts and transfrags were identified. Pathway analysis of the top 100 most highly expressed transcripts, which included TCHH and keratin gene family members, such as KRT25, KRT5, KRT71, KRT14 and others, showed pathways known to be relevant to hair/fleece development and function. Six hundred differentially expressed (DE) transcripts were detected at two different physiological ages (one-month-old with curly fleece and 48-month-old without curly fleece) and were categorized into three major functional groups: cellular component, molecular function, and biological process. The top six functional categories included cell, cell part, cellular process, binding, intracellular, metabolic process. The detected differentially expressed genes were particularly involved in signal, signal peptide, disulfide bond, glycoprotein and secreted terms, respectively. Further splicing isoform analysis showed that the metallothionein 3 isoform was up-regulated in Tan lamb skin, indicating that it may be related to the conformation of curly fleece in Chinese Tan lamb. The hair-related important differentially expressed genes (SPINK4, FGF21, ESRα, EphA3, NTNG1 and GPR110) were confirmed by qPCR analysis. We deduced that the differences existed in expressed transcripts, splice isoforms and GO categories between the two different physiological stages, which might constitute the major reasons for explaining the trait evolvement of curly fleece in Chinese Tan sheep. This study provides some clues for elucidating the molecular mechanism of fleece change with age in Chinese Tan sheep, as well as supplying some potential values for understanding human hair disorder and texture changes. PMID:23990983

NF-κB Essential Modulator (NEMO) Is Critical for Thyroid Function.

PubMed

Reale, Carla; Iervolino, Anna; Scudiero, Ivan; Ferravante, Angela; D'Andrea, Luca Egildo; Mazzone, Pellegrino; Zotti, Tiziana; Leonardi, Antonio; Roberto, Luca; Zannini, Mariastella; de Cristofaro, Tiziana; Shanmugakonar, Muralitharan; Capasso, Giovambattista; Pasparakis, Manolis; Vito, Pasquale; Stilo, Romania

2016-03-11

The I-κB kinase (IKK) subunit NEMO/IKKγ (NEMO) is an adapter molecule that is critical for canonical activation of NF-κB, a pleiotropic transcription factor controlling immunity, differentiation, cell growth, tumorigenesis, and apoptosis. To explore the functional role of canonical NF-κB signaling in thyroid gland differentiation and function, we have generated a murine strain bearing a genetic deletion of the NEMO locus in thyroid. Here we show that thyrocyte-specific NEMO knock-out mice gradually develop hypothyroidism after birth, which leads to reduced body weight and shortened life span. Histological and molecular analysis indicate that absence of NEMO in thyrocytes results in a dramatic loss of the thyroid gland cellularity, associated with down-regulation of thyroid differentiation markers and ongoing apoptosis. Thus, NEMO-dependent signaling is essential for normal thyroid physiology. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

A review of thermoregulation and physiological performance in reptiles: what is the role of phenotypic flexibility?

PubMed

Seebacher, Frank

2005-10-01

Biological functions are dependent on the temperature of the organism. Animals may respond to fluctuation in the thermal environment by regulating their body temperature and by modifying physiological and biochemical rates. Phenotypic flexibility (reversible phenotypic plasticity, acclimation, or acclimatisation in rate functions occurs in all major taxonomic groups and may be considered as an ancestral condition. Within the Reptilia, representatives from all major groups show phenotypic flexibility in response to long-term or chronic changes in the thermal environment. Acclimation or acclimatisation in reptiles are most commonly assessed by measuring whole animal responses such as oxygen consumption, but whole animal responses are comprised of variation in individual traits such as enzyme activities, hormone expression, and cardiovascular functions. The challenge now lies in connecting the changes in the components to the functioning of the whole animal and its fitness. Experimental designs in research on reptilian thermal physiology should incorporate the capacity for reversible phenotypic plasticity as a null-hypothesis, because the significance of differential body temperature-performance relationships (thermal reaction norms) between individuals, populations, or species cannot be assessed without testing that null-hypothesis.

Expressed Sequence Reference Standards for Evaluating Stage-specific Gene Expression in Southern Green Lacewings, Chrysoperla rufilabris

USDA-ARS?s Scientific Manuscript database

Five developmental stages of Chrysoperla rufilabris were tested using nine primer pairs. Three sequences were highly expressed at all life stages and six were differentially expressed. These primer pairs may be used as standards to quantitate functional gene expression associated with physiological ...

Comprehensive evaluation of poly(I:C) induced inflammatory response in an airway epithelial model

PubMed Central

Lever, Amanda R; Park, Hyoungshin; Mulhern, Thomas J; Jackson, George R; Comolli, James C; Borenstein, Jeffrey T; Hayden, Patrick J; Prantil-Baun, Rachelle

2015-01-01

Respiratory viruses invade the upper airway of the lung, triggering a potent immune response that often exacerbates preexisting conditions such as asthma and COPD. Poly(I:C) is a synthetic analog of viral dsRNA that induces the characteristic inflammatory response associated with viral infection, such as loss of epithelial integrity, and increased production of mucus and inflammatory cytokines. Here, we explore the mechanistic responses to poly(I:C) in a well-defined primary normal human bronchial epithelial (NHBE) model that recapitulates in vivo functions and responses. We developed functional and quantifiable methods to evaluate the physiology of our model in both healthy and inflamed states. Through gene and protein expression, we validated the differentiation state and population of essential cell subtypes (i.e., ciliated, goblet, club, and basal cells) as compared to the human lung. Assays for total mucus production, cytokine secretion, and barrier function were used to evaluate in vitro physiology and response to viral insult. Cells were treated apically with poly(I:C) and evaluated 48 h after induction. Results revealed a dose-dependent increase in goblet cell differentiation, as well as, an increase in mucus production relative to controls. There was also a dose-dependent increase in secretion of IL-6, IL-8, TNF-α, and RANTES. Epithelial barrier function, as measured by TEER, was maintained at 1501 ± 355 Ω*cm² postdifferentiation, but dropped significantly when challenged with poly(I:C). This study provides first steps toward a well-characterized model with defined functional methods for understanding dsRNA stimulated inflammatory responses in a physiologically relevant manner. PMID:25847914

Comparative proteomic analysis reveals the positive effect of exogenous spermidine on photosynthesis and salinity tolerance in cucumber seedlings.

PubMed

Sang, Ting; Shan, Xi; Li, Bin; Shu, Sheng; Sun, Jin; Guo, Shirong

2016-08-01

Our results based on proteomics data and physiological alterations proposed the putative mechanism of exogenous Spd enhanced salinity tolerance in cucumber seedlings. Current studies showed that exogenous spermidine (Spd) could alleviate harmful effects of salinity. It is important to increase our understanding of the beneficial physiological responses of exogenous Spd treatment, and to determine the molecular responses underlying these responses. Here, we combined a physiological analysis with iTRAQ-based comparative proteomics of cucumber (Cucumis sativus L.) leaves, treated with 0.1 mM exogenous Spd, 75 mM NaCl and/or exogenous Spd. A total of 221 differentially expressed proteins were found and involved in 30 metabolic pathways, such as photosynthesis, carbohydrate metabolism, amino acid metabolism, stress response, signal transduction and antioxidant. Based on functional classification of the differentially expressed proteins and the physiological responses, we found cucumber seedlings treated with Spd under salt stress had higher photosynthesis efficiency, upregulated tetrapyrrole synthesis, stronger ROS scavenging ability and more protein biosynthesis activity than NaCl treatment, suggesting that these pathways may promote salt tolerance under high salinity. This study provided insights into how exogenous Spd protects photosynthesis and enhances salt tolerance in cucumber seedlings.

Hypercholesterolemia induces adipose dysfunction in conditions of obesity and nonobesity.

PubMed

Aguilar, David; Fernandez, Maria Luz

2014-09-01

It is well known that hypercholesterolemia can lead to atherosclerosis and coronary heart disease. Adipose tissue represents an active endocrine and metabolic site, which might be involved in the development of chronic disease. Because adipose tissue is a key site for cholesterol metabolism and the presence of hypercholesterolemia has been shown to induce adipocyte cholesterol overload, it is critical to investigate the role of hypercholesterolemia on normal adipose function. Studies in preadipocytes revealed that cholesterol accumulation can impair adipocyte differentiation and maturation by affecting multiple transcription factors. Hypercholesterolemia has been observed to cause adipocyte hypertrophy, adipose tissue inflammation, and disruption of endocrine function in animal studies. Moreover, these effects can also be observed in obesity-independent conditions as confirmed by clinical trials. In humans, hypercholesterolemia disrupts adipose hormone secretion of visfatin, leptin, and adiponectin, adipokines that play a central role in numerous metabolic pathways and regulate basic physiologic responses such as appetite and satiety. Remarkably, treatment with cholesterol-lowering drugs has been shown to restore adipose tissue endocrine function. In this review the role of hypercholesterolemia on adipose tissue differentiation and maturation, as well as on hormone secretion and physiologic outcomes, in obesity and non–obesity conditions is presented.

Physiological role of urothelial cancer-associated one long noncoding RNA in human skeletogenic cell differentiation.

PubMed

Ishikawa, Takanori; Nishida, Takashi; Ono, Mitsuaki; Takarada, Takeshi; Nguyen, Ha Thi; Kurihara, Shinnosuke; Furumatsu, Takayuki; Murase, Yurika; Takigawa, Masaharu; Oohashi, Toshitaka; Kamioka, Hiroshi; Kubota, Satoshi

2018-06-01

A vast number of long-noncoding RNAs (lncRNA) are found expressed in human cells, which RNAs have been developed along with human evolution. However, the physiological functions of these lncRNAs remain mostly unknown. In the present study, we for the first time uncovered the fact that one of such lncRNAs plays a significant role in the differentiation of chondrocytes and, possibly, of osteoblasts differentiated from mesenchymal stem cells, which cells eventually construct the human skeleton. The urothelial cancer-associated 1 (UCA1) lncRNA is known to be associated with several human malignancies. Firstly, we confirmed that UCA1 was expressed in normal human chondrocytes, as well as in a human chondrocytic cell line; whereas it was not detected in human bone marrow mesenchymal stem cells (hBMSCs). Of note, although UCA1 expression was undetectable in hBMSCs, it was markedly induced along with the differentiation toward chondrocytes, suggesting its critical role in chondrogenesis. Consistent with this finding, silencing of the UCA1 gene significantly repressed the expression of chondrogenic genes in human chondrocytic cells. UCA1 gene silencing and hyper-expression also had a significant impact on the osteoblastic phenotype in a human cell line. Finally, forced expression of UCA1 in a murine chondrocyte precursor, which did not possess a UCA1 gene, overdrove its differentiation into chondrocytes. These results indicate a physiological and important role of this lncRNA in the skeletal development of humans, who require more sustained endochondral ossification and osteogenesis than do smaller vertebrates. © 2017 Wiley Periodicals, Inc.

Plasticity of brain wave network interactions and evolution across physiologic states

PubMed Central

Liu, Kang K. L.; Bartsch, Ronny P.; Lin, Aijing; Mantegna, Rosario N.; Ivanov, Plamen Ch.

2015-01-01

Neural plasticity transcends a range of spatio-temporal scales and serves as the basis of various brain activities and physiologic functions. At the microscopic level, it enables the emergence of brain waves with complex temporal dynamics. At the macroscopic level, presence and dominance of specific brain waves is associated with important brain functions. The role of neural plasticity at different levels in generating distinct brain rhythms and how brain rhythms communicate with each other across brain areas to generate physiologic states and functions remains not understood. Here we perform an empirical exploration of neural plasticity at the level of brain wave network interactions representing dynamical communications within and between different brain areas in the frequency domain. We introduce the concept of time delay stability (TDS) to quantify coordinated bursts in the activity of brain waves, and we employ a system-wide Network Physiology integrative approach to probe the network of coordinated brain wave activations and its evolution across physiologic states. We find an association between network structure and physiologic states. We uncover a hierarchical reorganization in the brain wave networks in response to changes in physiologic state, indicating new aspects of neural plasticity at the integrated level. Globally, we find that the entire brain network undergoes a pronounced transition from low connectivity in Deep Sleep and REM to high connectivity in Light Sleep and Wake. In contrast, we find that locally, different brain areas exhibit different network dynamics of brain wave interactions to achieve differentiation in function during different sleep stages. Moreover, our analyses indicate that plasticity also emerges in frequency-specific networks, which represent interactions across brain locations mediated through a specific frequency band. Comparing frequency-specific networks within the same physiologic state we find very different degree of network connectivity and link strength, while at the same time each frequency-specific network is characterized by a different signature pattern of sleep-stage stratification, reflecting a remarkable flexibility in response to change in physiologic state. These new aspects of neural plasticity demonstrate that in addition to dominant brain waves, the network of brain wave interactions is a previously unrecognized hallmark of physiologic state and function. PMID:26578891

RNA-seq analysis of broiler liver transcriptome reveals novel responses to high ambient temperature.

PubMed

Coble, Derrick J; Fleming, Damarius; Persia, Michael E; Ashwell, Chris M; Rothschild, Max F; Schmidt, Carl J; Lamont, Susan J

2014-12-10

In broilers, high ambient temperature can result in reduced feed consumption, digestive inefficiency, impaired metabolism, and even death. The broiler sector of the U.S. poultry industry incurs approximately $52 million in heat-related losses annually. The objective of this study is to characterize the effects of cyclic high ambient temperature on the transcriptome of a metabolically active organ, the liver. This study provides novel insight into the effects of high ambient temperature on metabolism in broilers, because it is the first reported RNA-seq study to characterize the effect of heat on the transcriptome of a metabolic-related tissue. This information provides a platform for future investigations to further elucidate physiologic responses to high ambient temperature and seek methods to ameliorate the negative impacts of heat. Transcriptome sequencing of the livers of 8 broiler males using Illumina HiSeq 2000 technology resulted in 138 million, 100-base pair single end reads, yielding a total of 13.8 gigabases of sequence. Forty genes were differentially expressed at a significance level of P-value < 0.05 and a fold-change ≥ 2 in response to a week of cyclic high ambient temperature with 27 down-regulated and 13 up-regulated genes. Two gene networks were created from the function-based Ingenuity Pathway Analysis (IPA) of the differentially expressed genes: "Cell Signaling" and "Endocrine System Development and Function". The gene expression differences in the liver transcriptome of the heat-exposed broilers reflected physiological responses to decrease internal temperature, reduce hyperthermia-induced apoptosis, and promote tissue repair. Additionally, the differential gene expression revealed a physiological response to regulate the perturbed cellular calcium levels that can result from high ambient temperature exposure. Exposure to cyclic high ambient temperature results in changes at the metabolic, physiologic, and cellular level that can be characterized through RNA-seq analysis of the liver transcriptome of broilers. The findings highlight specific physiologic mechanisms by which broilers reduce the effects of exposure to high ambient temperature. This information provides a foundation for future investigations into the gene networks involved in the broiler stress response and for development of strategies to ameliorate the negative impacts of heat on animal production and welfare.

Using Osteoclast Differentiation as a Model for Gene Discovery in an Undergraduate Cell Biology Laboratory

ERIC Educational Resources Information Center

Birnbaum, Mark J.; Picco, Jenna; Clements, Meghan; Witwicka, Hanna; Yang, Meiheng; Hoey, Margaret T.; Odgren, Paul R.

2010-01-01

A key goal of molecular/cell biology/biotechnology is to identify essential genes in virtually every physiological process to uncover basic mechanisms of cell function and to establish potential targets of drug therapy combating human disease. This article describes a semester-long, project-oriented molecular/cellular/biotechnology laboratory…

Characterization of an enantioselective odorant receptor in the yellow fever mosquito aedes aegypti

USDA-ARS?s Scientific Manuscript database

In chemical communication systems, optical isomers have been shown to be differentially active at the physiological and behavioral levels. One enantiomer may serve as an attractant for one species while its antipode may function as a disruptant or repellent in another species or even within the sam...

ω-3 polyunsaturated fatty acids direct differentiation of the membrane phenotype in mesenchymal stem cells to potentiate osteogenesis

PubMed Central

Levental, Kandice R.; Surma, Michal A.; Skinkle, Allison D.; Lorent, Joseph H.; Zhou, Yong; Klose, Christian; Chang, Jeffrey T.; Hancock, John F.; Levental, Ilya

2017-01-01

Mammalian cells produce hundreds of dynamically regulated lipid species that are actively turned over and trafficked to produce functional membranes. These lipid repertoires are susceptible to perturbations from dietary sources, with potentially profound physiological consequences. However, neither the lipid repertoires of various cellular membranes, their modulation by dietary fats, nor their effects on cellular phenotypes have been widely explored. We report that differentiation of human mesenchymal stem cells (MSCs) into osteoblasts or adipocytes results in extensive remodeling of the plasma membrane (PM), producing cell-specific membrane compositions and biophysical properties. The distinct features of osteoblast PMs enabled rational engineering of membrane phenotypes to modulate differentiation in MSCs. Specifically, supplementation with docosahexaenoic acid (DHA), a lipid component characteristic of osteoblast membranes, induced broad lipidomic remodeling in MSCs that reproduced compositional and structural aspects of the osteoblastic PM phenotype. The PM changes induced by DHA supplementation potentiated osteogenic differentiation of MSCs concurrent with enhanced Akt activation at the PM. These observations prompt a model wherein the DHA-induced lipidome leads to more stable membrane microdomains, which serve to increase Akt activity and thereby enhance osteogenic differentiation. More broadly, our investigations suggest a general mechanism by which dietary fats affect cellular physiology through remodeling of membrane lipidomes, biophysical properties, and signaling. PMID:29134198

The functional relevance of polyploidization in the skin.

PubMed

Trakala, Marianna; Malumbres, Marcos

2014-02-01

Cell proliferation and differentiation are tightly coupled through the regulation of the cell division cycle. To preserve specific functional properties in differentiated cells, distinct variants of the basic mitotic cell cycle are used in various mammalian tissues, leading to the formation of polyploid cells. In this issue of Experimental Dermatology, Gandarillas and Freije discuss the evidences for polyploidization in keratinocytes, a process whose physiological relevance is now becoming evident. A better evaluation of these unconventional cell cycles is required not only to improve our understanding of the development and structure of the epidermis but also for future therapies against skin diseases. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evaluation of a pilot workload metric for simulated VTOL landing tasks

NASA Technical Reports Server (NTRS)

North, R. A.; Graffunder, K.

1979-01-01

A methodological approach to measuring workload was investigated for evaluation of new concepts in VTOL aircraft displays. Multivariate discriminant functions were formed from conventional flight performance and/or visual response variables to maximize detection of experimental differences. The flight performance variable discriminant showed maximum differentiation between crosswind conditions. The visual response measure discriminant maximized differences between fixed vs. motion base conditions and experimental displays. Physiological variables were used to attempt to predict the discriminant function values for each subject/condition/trial. The weights of the physiological variables in these equations showed agreement with previous studies. High muscle tension, light but irregular breathing patterns, and higher heart rate with low amplitude all produced higher scores on this scale and thus, represented higher workload levels.

Temperature-induced changes in neuromuscular function: central and peripheral mechanisms.

PubMed

Goodman, D; Hancock, P A; Runnings, D W; Brown, S L

1984-10-01

Three series of experimental tests were conducted on subjects under both elevated and depressed thermal conditions. Tripartite series consisted of whole-body immersion excepting the head, whole-body immersion excepting the head and response limb, and immersion of the discrete-response limb. Measures of physiological and behavioural responses were made at sequential .4 degrees C changes during whole-body immersions and approximately 5 degrees C changes of water temperature during the immersion of a limb only. Results suggested that velocity of nerve conduction decreased with thermal depression. Premotor, motor, simple, and choice reaction times varied differentially as a function of the hot and cold conditions. Implications of these differential effects on neuromuscular function are examined with respect to person-machine performance in artificially induced or naturally occurring extremes of ambient temperature.

Unperturbed vs. post-transplantation hematopoiesis: both in vivo but different.

PubMed

Busch, Katrin; Rodewald, Hans-Reimer

2016-07-01

Hematopoietic stem cell (HSC) transplantation has yielded tremendous information on experimental properties of HSCs. Yet, it remains unclear whether transplantation reflects the physiology of hematopoiesis. A limitation is the difficulty in accessing HSC functions without isolation, in-vitro manipulation and readout for potential. New genetic fate mapping and clonal marking techniques now shed light on hematopoiesis under physiological conditions. Transposon-based genetic marks were introduced across the entire hematopoietic system to follow the clonal dynamics of these tags over time. A polyclonal source downstream from stem cells was found responsible for the production of at least granulocytes. In independent experiments, HSCs were genetically marked in adult mice, and the kinetics of label emergence throughout the system was followed over time. These experiments uncovered that during physiological steady-state hematopoiesis large numbers of HSCs yield differentiated progeny. Individual HSCs were active only rarely, indicating their very slow periodicity of differentiation rather than quiescence. Noninvasive genetic experiments in mice have identified a major role of stem and progenitor cells downstream from HSCs as drivers of adult hematopoiesis, and revealed that post-transplantation hematopoiesis differs quantitatively from normal steady-state hematopoiesis.

[Effects of bushen yinao tablet on physiology and cerebral gene expression in senescence-accelerated mice].

PubMed

Zhang, Chong; Wang, Jin-gang; Yang, Ting

2006-06-01

To study the effects of Bushen Yin' ao Tablet (BSYNT) on physiology and cerebral gene expression in senescence-accelerated mice (SAM). The change of cerebral tissues mRNA expression in SAM was analyzed and compared by messenger ribonucleic acids reverse transcription differential display polymerase chain reaction (mRNA DDRT-PCR) between the medicated group and the control group. BSYNT could increase the level of hemoglobin (Hb) and amount of erythrocyte (RBC) of blood deficiency mice, improve the spatial learning and memory function and the escape response by conditional stimulus. In this study, 14 differential display bands had been discerned, and three of them had been sequenced. The sequence of the three fragments was similar to fatty acid binding protein 7, ubiquinol-cytochrome C reductase complex (7. 2 kD) and 60S ribosomal protein L21 respectively. And the homogeneity was 97% , 100% , and 99% , respectively. BSYNT has effect on the physiological changing of mice, and its effect on cerebral tissues mRNA expression maybe play an important role in anti-aging on the molecular level.

Identification of a type II cystatin in Fragaria chiloensis: A proteinase inhibitor differentially regulated during achene development and in response to biotic stress-related stimuli.

PubMed

Aceituno-Valenzuela, Uri; Covarrubias, María Paz; Aguayo, María Francisca; Valenzuela-Riffo, Felipe; Espinoza, Analía; Gaete-Eastman, Carlos; Herrera, Raúl; Handford, Michael; Norambuena, Lorena

2018-05-19

The equilibrium between protein synthesis and degradation is key to maintaining efficiency in different physiological processes. The proteinase inhibitor cystatin regulates protease activities in different developmental and physiological contexts. Here we describe for the first time the identification and the biological function of the cysteine protease inhibitor cystatin of Fragaria chiloensis, FchCYS1. Based on primary sequence and 3D-structural homology modelling, FchCYS1 is a type II phytocystatin with high identity to other cystatins of the Fragaria genus. Both the papain-like and the legumain-like protease inhibitory domains are indeed functional, based on in vitro assays performed with Escherichia coli protein extracts containing recombinant FchCYS1. FchCYS1 is differentially-expressed in achenes of F. chiloensis fruits, with highest expression as the fruit reaches the ripened stage, suggesting a role in preventing degradation of storage proteins that will nourish the embryo during seed germination. Furthermore, FchCYS1 responds transcriptionally to the application of salicylic acid and to mechanical injury, strongly suggesting that FchCYS1 could be involved in the response against pathogen attack. Overall these results point to a role for FchCYS1 in diverse physiological processes in F. chiloensis. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Methodological Choices in Muscle Synergy Analysis Impact Differentiation of Physiological Characteristics Following Stroke

PubMed Central

Banks, Caitlin L.; Pai, Mihir M.; McGuirk, Theresa E.; Fregly, Benjamin J.; Patten, Carolynn

2017-01-01

Muscle synergy analysis (MSA) is a mathematical technique that reduces the dimensionality of electromyographic (EMG) data. Used increasingly in biomechanics research, MSA requires methodological choices at each stage of the analysis. Differences in methodological steps affect the overall outcome, making it difficult to compare results across studies. We applied MSA to EMG data collected from individuals post-stroke identified as either responders (RES) or non-responders (nRES) on the basis of a critical post-treatment increase in walking speed. Importantly, no clinical or functional indicators identified differences between the cohort of RES and nRES at baseline. For this exploratory study, we selected the five highest RES and five lowest nRES available from a larger sample. Our goal was to assess how the methodological choices made before, during, and after MSA affect the ability to differentiate two groups with intrinsic physiologic differences based on MSA results. We investigated 30 variations in MSA methodology to determine which choices allowed differentiation of RES from nRES at baseline. Trial-to-trial variability in time-independent synergy vectors (SVs) and time-varying neural commands (NCs) were measured as a function of: (1) number of synergies computed; (2) EMG normalization method before MSA; (3) whether SVs were held constant across trials or allowed to vary during MSA; and (4) synergy analysis output normalization method after MSA. MSA methodology had a strong effect on our ability to differentiate RES from nRES at baseline. Across all 10 individuals and MSA variations, two synergies were needed to reach an average of 90% variance accounted for (VAF). Based on effect sizes, differences in SV and NC variability between groups were greatest using two synergies with SVs that varied from trial-to-trial. Differences in SV variability were clearest using unit magnitude per trial EMG normalization, while NC variability was less sensitive to EMG normalization method. No outcomes were greatly impacted by output normalization method. MSA variability for some, but not all, methods successfully differentiated intrinsic physiological differences inaccessible to traditional clinical or biomechanical assessments. Our results were sensitive to methodological choices, highlighting the need for disclosure of all aspects of MSA methodology in future studies. PMID:28912707

Methodological Choices in Muscle Synergy Analysis Impact Differentiation of Physiological Characteristics Following Stroke.

PubMed

Banks, Caitlin L; Pai, Mihir M; McGuirk, Theresa E; Fregly, Benjamin J; Patten, Carolynn

2017-01-01

Muscle synergy analysis (MSA) is a mathematical technique that reduces the dimensionality of electromyographic (EMG) data. Used increasingly in biomechanics research, MSA requires methodological choices at each stage of the analysis. Differences in methodological steps affect the overall outcome, making it difficult to compare results across studies. We applied MSA to EMG data collected from individuals post-stroke identified as either responders (RES) or non-responders (nRES) on the basis of a critical post-treatment increase in walking speed. Importantly, no clinical or functional indicators identified differences between the cohort of RES and nRES at baseline. For this exploratory study, we selected the five highest RES and five lowest nRES available from a larger sample. Our goal was to assess how the methodological choices made before, during, and after MSA affect the ability to differentiate two groups with intrinsic physiologic differences based on MSA results. We investigated 30 variations in MSA methodology to determine which choices allowed differentiation of RES from nRES at baseline. Trial-to-trial variability in time-independent synergy vectors (SVs) and time-varying neural commands (NCs) were measured as a function of: (1) number of synergies computed; (2) EMG normalization method before MSA; (3) whether SVs were held constant across trials or allowed to vary during MSA; and (4) synergy analysis output normalization method after MSA. MSA methodology had a strong effect on our ability to differentiate RES from nRES at baseline. Across all 10 individuals and MSA variations, two synergies were needed to reach an average of 90% variance accounted for (VAF). Based on effect sizes, differences in SV and NC variability between groups were greatest using two synergies with SVs that varied from trial-to-trial. Differences in SV variability were clearest using unit magnitude per trial EMG normalization, while NC variability was less sensitive to EMG normalization method. No outcomes were greatly impacted by output normalization method. MSA variability for some, but not all, methods successfully differentiated intrinsic physiological differences inaccessible to traditional clinical or biomechanical assessments. Our results were sensitive to methodological choices, highlighting the need for disclosure of all aspects of MSA methodology in future studies.

Proximity-Based Differential Single-Cell Analysis of the Niche to Identify Stem/Progenitor Cell Regulators.

PubMed

Silberstein, Lev; Goncalves, Kevin A; Kharchenko, Peter V; Turcotte, Raphael; Kfoury, Youmna; Mercier, Francois; Baryawno, Ninib; Severe, Nicolas; Bachand, Jacqueline; Spencer, Joel A; Papazian, Ani; Lee, Dongjun; Chitteti, Brahmananda Reddy; Srour, Edward F; Hoggatt, Jonathan; Tate, Tiffany; Lo Celso, Cristina; Ono, Noriaki; Nutt, Stephen; Heino, Jyrki; Sipilä, Kalle; Shioda, Toshihiro; Osawa, Masatake; Lin, Charles P; Hu, Guo-Fu; Scadden, David T

2016-10-06

Physiological stem cell function is regulated by secreted factors produced by niche cells. In this study, we describe an unbiased approach based on the differential single-cell gene expression analysis of mesenchymal osteolineage cells close to, and further removed from, hematopoietic stem/progenitor cells (HSPCs) to identify candidate niche factors. Mesenchymal cells displayed distinct molecular profiles based on their relative location. We functionally examined, among the genes that were preferentially expressed in proximal cells, three secreted or cell-surface molecules not previously connected to HSPC biology-the secreted RNase angiogenin, the cytokine IL18, and the adhesion molecule Embigin-and discovered that all of these factors are HSPC quiescence regulators. Therefore, our proximity-based differential single-cell approach reveals molecular heterogeneity within niche cells and can be used to identify novel extrinsic stem/progenitor cell regulators. Similar approaches could also be applied to other stem cell/niche pairs to advance the understanding of microenvironmental regulation of stem cell function. Copyright © 2016 Elsevier Inc. All rights reserved.

Regulation of proximal tubular cell differentiation and proliferation in primary culture by matrix stiffness and ECM components.

PubMed

Chen, Wan-Chun; Lin, Hsi-Hui; Tang, Ming-Jer

2014-09-15

To explore whether matrix stiffness affects cell differentiation, proliferation, and transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) in primary cultures of mouse proximal tubular epithelial cells (mPTECs), we used a soft matrix made from monomeric collagen type I-coated polyacrylamide gel or matrigel (MG). Both kinds of soft matrix benefited primary mPTECs to retain tubular-like morphology with differentiation and growth arrest and to evade TGF-β1-induced EMT. However, the potent effect of MG on mPTEC differentiation was suppressed by glutaraldehyde-induced cross-linking and subsequently stiffening MG or by an increasing ratio of collagen in the soft mixed gel. Culture media supplemented with MG also helped mPTECs to retain tubular-like morphology and a differentiated phenotype on stiff culture dishes as soft MG did. We further found that the protein level and activity of ERK were scaled with the matrix stiffness. U-0126, a MEK inhibitor, abolished the stiff matrix-induced dedifferentiation and proliferation. These data suggest that the ERK signaling pathway plays a vital role in matrix stiffness-regulated cell growth and differentiation. Taken together, both compliant property and specific MG signals from the matrix are required for the regulation of epithelial differentiation and proliferation. This study provides a basic understanding of how physical and chemical cues derived from the extracellular matrix regulate the physiological function of proximal tubules and the pathological development of renal fibrosis. Copyright © 2014 the American Physiological Society.

ISOFORMS OF VITAMIN E DIFFERENTIALLY REGULATE INFLAMMATION

PubMed Central

Cook-Mills, Joan M.; McCary, Christine A.

2011-01-01

Vitamin E regulation of disease has been extensively studied in humans, animal models and cell systems. Most of these studies focus on the α-tocopherol isoform of vitamin E. These reports indicate contradictory outcomes for anti-inflammatory functions of the α-tocopherol isoform of vitamin E, especially with regards to clinical studies of asthma and atherosclerosis. These seemingly disparate clinical results are consistent with recently reported unrecognized properties of isoforms of vitamin E. Recently, it has been reported that physiological levels of purified natural forms of vitamin E have opposing regulatory functions during inflammation. These opposing regulatory functions by physiological levels of vitamin E isoforms impact interpretations of previous studies on vitamin E. Moreover, additional recent studies also indicate that the effects of vitamin E isoforms on inflammation are only partially reversible using physiological levels of a vitamin E isoform with opposing immunoregulatory function. Thus, this further influences interpretations of previous studies with vitamin E in which there was inflammation and substantial vitamin E isoforms present before the initiation of the study. In summary, this review will discuss regulation of inflammation by vitamin E, including alternative interpretations of previous studies in the literature with regards to vitamin E isoforms. PMID:20923401

Prohibitin( PHB) roles in granulosa cell physiology.

PubMed

Chowdhury, Indrajit; Thomas, Kelwyn; Thompson, Winston E

2016-01-01

Ovarian granulosa cells (GC) play an important role in the growth and development of the follicle in the process known as folliculogenesis. In the present review, we focus on recent developments in prohibitin (PHB) research in relation to GC physiological functions. PHB is a member of a highly conserved eukaryotic protein family containing the repressor of estrogen activity (REA)/stomatin/PHB/flotillin/HflK/C (SPFH) domain (also known as the PHB domain) found in diverse species from prokaryotes to eukaryotes. PHB is ubiquitously expressed in a circulating free form or is present in multiple cellular compartments including mitochondria, nucleus and plasma membrane. In mitochondria, PHB is anchored to the mitochondrial inner membrane and forms complexes with the ATPases associated with proteases having diverse cellular activities. PHB continuously shuttles between the mitochondria, cytosol and nucleus. In the nucleus, PHB interacts with various transcription factors and modulates transcriptional activity directly or through interactions with chromatin remodeling proteins. Many functions have been attributed to the mitochondrial and nuclear PHB complexes such as cellular differentiation, anti-proliferation, morphogenesis and maintenance of the functional integrity of the mitochondria. However, to date, the regulation of PHB expression patterns and GC physiological functions are not completely understood.

Prohibitin (PHB) roles in granulosa cell physiology

PubMed Central

Chowdhury, Indrajit; Thomas, Kelwyn; Thompson, Winston E.

2015-01-01

Ovarian granulosa cells (GC) play an important role in the growth and development of the follicle in the process known as folliculogenesis. In the present review, we focus on the recent developments in prohibitin (PHB) research in relation to GC physiological functions. PHB is a member of highly conserved eukaryotic protein family containing the repressor of estrogen activity (REA)/stomatin/prohibitin/flotillin/HflK/C (SPFH) domain [also known as the PHB domain] found in divergent species from prokaryotes to eukaryotes. PHB is ubiquitously expressed either in circulating free form or is present in multiple cellular compartments including mitochondria, nucleus and plasma membrane. In mitochondria, PHB is anchored to the mitochondrial inner membrane (IMM), and form complexes with the ATPases Associated with diverse cellular Activities (m-AAA) proteases. PHB continuously shuttles between the mitochondria, cytosol and nucleus. In the nucleus, PHB interacts with various transcription factors and modulate transcriptional activity directly or through interactions with chromatin remodeling proteins. Multiple functions have been attributed to the mitochondrial and nuclear prohibitin complexes such as cellular differentiation, anti-proliferation, morphogenesis and maintaining the functional integrity of the mitochondria. However, to date, the regulation of PHB expression patterns and GC physiological functions are not completely understood. PMID:26496733

Structural, Functional, and Metabolic Brain Markers Differentiate Collision versus Contact and Non-Contact Athletes

PubMed Central

Churchill, Nathan W.; Hutchison, Michael G.; Di Battista, Alex P.; Graham, Simon J.; Schweizer, Tom A.

2017-01-01

There is growing concern about how participation in contact sports affects the brain. Retrospective evidence suggests that contact sports are associated with long-term negative health outcomes. However, much of the research to date has focused on former athletes with significant health problems. Less is known about the health of current athletes in contact and collision sports who have not reported significant medical issues. In this cross-sectional study, advanced magnetic resonance imaging (MRI) was used to evaluate multiple aspects of brain physiology in three groups of athletes participating in non-contact sports (N = 20), contact sports (N = 22), and collision sports (N = 23). Diffusion tensor imaging was used to assess white matter microstructure based on measures of fractional anisotropy (FA) and mean diffusivity (MD); resting-state functional MRI was used to evaluate global functional connectivity; single-voxel spectroscopy was used to compare ratios of neural metabolites, including N-acetyl aspartate (NAA), creatine (Cr), choline, and myo-inositol. Multivariate analysis revealed structural, functional, and metabolic measures that reliably differentiated between sport groups. The collision group had significantly elevated FA and reduced MD in white matter, compared to both contact and non-contact groups. In contrast, the collision group showed significant reductions in functional connectivity and the NAA/Cr metabolite ratio, relative to only the non-contact group, while the contact group overlapped with both non-contact and collision groups. For brain regions associated with contact sport participation, athletes with a history of concussion also showed greater alterations in FA and functional connectivity, indicating a potential cumulative effect of both contact exposure and concussion history on brain physiology. These findings indicate persistent differences in brain physiology for athletes participating in contact and collision sports, which should be considered in future studies of concussion and subconcussive impacts. PMID:28878729

Prolactin receptor, growth hormone receptor, and putative somatolactin receptor in Mozambique tilapia: tissue specific expression and differential regulation by salinity and fasting.

PubMed

Pierce, A L; Fox, B K; Davis, L K; Visitacion, N; Kitahashi, T; Hirano, T; Grau, E G

2007-01-01

In fish, pituitary growth hormone family peptide hormones (growth hormone, GH; prolactin, PRL; somatolactin, SL) regulate essential physiological functions including osmoregulation, growth, and metabolism. Teleost GH family hormones have both differential and overlapping effects, which are mediated by plasma membrane receptors. A PRL receptor (PRLR) and two putative GH receptors (GHR1 and GHR2) have been identified in several teleost species. Recent phylogenetic analyses and binding studies suggest that GHR1 is a receptor for SL. However, no studies have compared the tissue distribution and physiological regulation of all three receptors. We sequenced GHR2 from the liver of the Mozambique tilapia (Oreochromis mossambicus), developed quantitative real-time PCR assays for the three receptors, and assessed their tissue distribution and regulation by salinity and fasting. PRLR was highly expressed in the gill, kidney, and intestine, consistent with the osmoregulatory functions of PRL. PRLR expression was very low in the liver. GHR2 was most highly expressed in the muscle, followed by heart, testis, and liver, consistent with this being a GH receptor with functions in growth and metabolism. GHR1 was most highly expressed in fat, liver, and muscle, suggesting a metabolic function. GHR1 expression was also high in skin, consistent with a function of SL in chromatophore regulation. These findings support the hypothesis that GHR1 is a receptor for SL. In a comparison of freshwater (FW)- and seawater (SW)-adapted tilapia, plasma PRL was strongly elevated in FW, whereas plasma GH was slightly elevated in SW. PRLR expression was reduced in the gill in SW, consistent with PRL's function in freshwater adaptation. GHR2 was elevated in the kidney in FW, and correlated negatively with plasma GH, whereas GHR1 was elevated in the gill in SW. Plasma IGF-I, but not GH, was reduced by 4 weeks of fasting. Transcript levels of GHR1 and GHR2 were elevated by fasting in the muscle. However, liver levels of GHR1 and GHR2 transcripts, and liver and muscle levels of IGF-I transcripts were unaffected by fasting. These results clearly indicate tissue specific expression and differential physiological regulation of GH family receptors in the tilapia.

Mining functionally relevant gene sets for analyzing physiologically novel clinical expression data.

PubMed

Turcan, Sevin; Vetter, Douglas E; Maron, Jill L; Wei, Xintao; Slonim, Donna K

2011-01-01

Gene set analyses have become a standard approach for increasing the sensitivity of transcriptomic studies. However, analytical methods incorporating gene sets require the availability of pre-defined gene sets relevant to the underlying physiology being studied. For novel physiological problems, relevant gene sets may be unavailable or existing gene set databases may bias the results towards only the best-studied of the relevant biological processes. We describe a successful attempt to mine novel functional gene sets for translational projects where the underlying physiology is not necessarily well characterized in existing annotation databases. We choose targeted training data from public expression data repositories and define new criteria for selecting biclusters to serve as candidate gene sets. Many of the discovered gene sets show little or no enrichment for informative Gene Ontology terms or other functional annotation. However, we observe that such gene sets show coherent differential expression in new clinical test data sets, even if derived from different species, tissues, and disease states. We demonstrate the efficacy of this method on a human metabolic data set, where we discover novel, uncharacterized gene sets that are diagnostic of diabetes, and on additional data sets related to neuronal processes and human development. Our results suggest that our approach may be an efficient way to generate a collection of gene sets relevant to the analysis of data for novel clinical applications where existing functional annotation is relatively incomplete.

Transcriptional profiles of Arabidopsis stomataless mutants reveal developmental and physiological features of life in the absence of stomata

PubMed Central

de Marcos, Alberto; Triviño, Magdalena; Pérez-Bueno, María Luisa; Ballesteros, Isabel; Barón, Matilde; Mena, Montaña; Fenoll, Carmen

2015-01-01

Loss of function of the positive stomata development regulators SPCH or MUTE in Arabidopsis thaliana renders stomataless plants; spch-3 and mute-3 mutants are extreme dwarfs, but produce cotyledons and tiny leaves, providing a system to interrogate plant life in the absence of stomata. To this end, we compared their cotyledon transcriptomes with that of wild-type plants. K-means clustering of differentially expressed genes generated four clusters: clusters 1 and 2 grouped genes commonly regulated in the mutants, while clusters 3 and 4 contained genes distinctively regulated in mute-3. Classification in functional categories and metabolic pathways of genes in clusters 1 and 2 suggested that both mutants had depressed secondary, nitrogen and sulfur metabolisms, while only a few photosynthesis-related genes were down-regulated. In situ quenching analysis of chlorophyll fluorescence revealed limited inhibition of photosynthesis. This and other fluorescence measurements matched the mutant transcriptomic features. Differential transcriptomes of both mutants were enriched in growth-related genes, including known stomata development regulators, which paralleled their epidermal phenotypes. Analysis of cluster 3 was not informative for developmental aspects of mute-3. Cluster 4 comprised genes differentially up−regulated in mute−3, 35% of which were direct targets for SPCH and may relate to the unique cell types of mute−3. A screen of T-DNA insertion lines in genes differentially expressed in the mutants identified a gene putatively involved in stomata development. A collection of lines for conditional overexpression of transcription factors differentially expressed in the mutants rendered distinct epidermal phenotypes, suggesting that these proteins may be novel stomatal development regulators. Thus, our transcriptome analysis represents a useful source of new genes for the study of stomata development and for characterizing physiology and growth in the absence of stomata. PMID:26157447

MicroRNAs in thyroid development, function and tumorigenesis.

PubMed

Fuziwara, Cesar Seigi; Kimura, Edna Teruko

2017-11-15

MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression that modulate the vast majority of cellular processes. During development, the correct timing and expression of miRNAs in the tissue differentiation is essential for organogenesis and functionality. In thyroid gland, DICER and miRNAs are necessary for accurately establishing thyroid follicles and hormone synthesis. Moreover, DICER1 mutations and miRNA deregulation observed in human goiter influence thyroid tumorigenesis. The thyroid malignant transformation by MAPK oncogenes is accompanied by global miRNA changes, with a marked reduction of "tumor-suppressor" miRNAs and activation of oncogenic miRNAs. Loss of thyroid cell differentiation/function, and consequently iodine trapping impairment, is an important clinical characteristic of radioiodine-refractory thyroid cancer. However, few studies have addressed the direct role of miRNAs in thyroid gland physiology. Here, we focus on what we have learned in the thyroid follicular cell differentiation and function as revealed by cell and animal models and miRNA modulation in thyroid tumorigenesis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The epithelial-mesenchymal interactions: insights into physiological and pathological aspects of oral tissues.

PubMed

Santosh, Arvind Babu Rajendra; Jones, Thaon Jon

2014-03-17

In the human biological system, the individual cells divide and form tissues and organs. These tissues are hetero-cellular. Basically any tissue consists of an epithelium and the connective tissue. The latter contains mainly mesenchymally-derived tissues with a diversified cell population. The cell continues to grow and differentiate in a pre-programmed manner using a messenger system. The epithelium and the mesenchymal portion of each tissue have two different origins and perform specific functions, but there is a well-defined interaction mechanism, which mediates between them. Epithelial mesenchymal interactions (EMIs) are part of this mechanism, which can be regarded as a biological conversation between epithelial and mesenchymal cell populations involved in the cellular differentiation of one or both cell populations. EMIs represent a process that is essential for cell growth, cell differentiation and cell multiplication. EMIs are associated with normal physiological processes in the oral cavity, such as odontogenesis, dentino-enamel junction formation, salivary gland development, palatogenesis, and also pathological processes, such as oral cancer. This paper focuses the role EMIs in odontogenesis, salivary gland development, palatogenesis and oral cancer.

Behavioral and Physiological Consequences of Sleep Restriction

PubMed Central

Banks, Siobhan; Dinges, David F.

2007-01-01

Adequate sleep is essential for general healthy functioning. This paper reviews recent research on the effects of chronic sleep restriction on neurobehavioral and physiological functioning and discusses implications for health and lifestyle. Restricting sleep below an individual's optimal time in bed (TIB) can cause a range of neurobehavioral deficits, including lapses of attention, slowed working memory, reduced cognitive throughput, depressed mood, and perseveration of thought. Neurobehavioral deficits accumulate across days of partial sleep loss to levels equivalent to those found after 1 to 3 nights of total sleep loss. Recent experiments reveal that following days of chronic restriction of sleep duration below 7 hours per night, significant daytime cognitive dysfunction accumulates to levels comparable to that found after severe acute total sleep deprivation. Additionally, individual variability in neurobehavioral responses to sleep restriction appears to be stable, suggesting a traitlike (possibly genetic) differential vulnerability or compensatory changes in the neurobiological systems involved in cognition. A causal role for reduced sleep duration in adverse health outcomes remains unclear, but laboratory studies of healthy adults subjected to sleep restriction have found adverse effects on endocrine functions, metabolic and inflammatory responses, suggesting that sleep restriction produces physiological consequences that may be unhealthy. Citation: Banks S; Dinges DF. Behavioral and physiological consequences of sleep restriction. J Clin Sleep Med 2007;3(5):519-528. PMID:17803017

The microRNA-processing enzyme Dicer is essential for thyroid function.

PubMed

Frezzetti, Daniela; Reale, Carla; Calì, Gaetano; Nitsch, Lucio; Fagman, Henrik; Nilsson, Ola; Scarfò, Marzia; De Vita, Gabriella; Di Lauro, Roberto

2011-01-01

Dicer is a type III ribonuclease required for the biogenesis of microRNAs (miRNAs), a class of small non-coding RNAs regulating gene expression at the post-transcriptional level. To explore the functional role of miRNAs in thyroid gland function, we generated a thyrocyte-specific Dicer conditional knockout mouse. Here we show that development and early differentiation of the thyroid gland are not affected by the absence of Dicer, while severe hypothyroidism gradually develops after birth, leading to reduced body weight and shortened life span. Histological and molecular characterization of knockout mice reveals a dramatic loss of the thyroid gland follicular architecture associated with functional aberrations and down-regulation of several differentiation markers. The data presented in this study show for the first time that an intact miRNAs processing machinery is essential for thyroid physiology, suggesting that deregulation of specific miRNAs could be also involved in human thyroid dysfunctions.

Pituitary cell differentiation from stem cells and other cells: toward restorative therapy for hypopituitarism?

PubMed

Willems, Christophe; Vankelecom, Hugo

2014-01-01

The pituitary gland, key regulator of our endocrine system, produces multiple hormones that steer essential physiological processes. Hence, deficient pituitary function (hypopituitarism) leads to severe disorders. Hypopituitarism can be caused by defective embryonic development, or by damage through tumor growth/resection and traumatic brain injury. Lifelong hormone replacement is needed but associated with significant side effects. It would be more desirable to restore pituitary tissue and function. Recently, we showed that the adult (mouse) pituitary holds regenerative capacity in which local stem cells are involved. Repair of deficient pituitary may therefore be achieved by activating these resident stem cells. Alternatively, pituitary dysfunction may be mended by cell (replacement) therapy. The hormonal cells to be transplanted could be obtained by (trans-)differentiating various kinds of stem cells or other cells. Here, we summarize the studies on pituitary cell regeneration and on (trans-)differentiation toward hormonal cells, and speculate on restorative therapies for pituitary deficiency.

Combined effects of chemical priming and mechanical stimulation on mesenchymal stem cell differentiation on nanofiber scaffolds

PubMed Central

Subramony, Siddarth D.; Su, Amanda; Yeager, Keith; Lu, Helen H.

2014-01-01

Functional tissue engineering of connective tissues such as the anterior cruciate ligament (ACL) remains a significant clinical challenge, largely due to the need for mechanically competent scaffold systems for grafting, as well as a reliable cell source for tissue formation. We have designed an aligned, polylactide-co-glycolide (PLGA) nanofiber-based scaffold with physiologically relevant mechanical properties for ligament regeneration. The objective of this study is to identify optimal tissue engineering strategies for fibroblastic induction of human mesenchymal stem cells (hMSC), testing the hypothesis that basic fibroblast growth factor (bFGF) priming coupled with tensile loading will enhance hMSC-mediated ligament regeneration. It was observed that compared to the unloaded, as well as growth factor-primed but unloaded controls, bFGF stimulation followed by physiologically relevant tensile loading enhanced hMSC proliferation, collagen production and subsequent differentiation into ligament fibroblast-like cells, upregulating the expression of types I and III collagen, as well as tenasin-C and tenomodulin. The results of this study suggest that bFGF priming increases cell proliferation, while mechanical stimulation of the hMSCs on the aligned nanofiber scaffold promotes fibroblastic induction of these cells. In addition to demonstrating the potential of nanofiber scaffolds for hMSC-mediated functional ligament tissue engineering, this study yields new insights into the interactive effects of chemical and mechanical stimuli on stem cell differentiation. PMID:24267271

The new vestibular stimuli: sound and vibration-anatomical, physiological and clinical evidence.

PubMed

Curthoys, Ian S

2017-04-01

The classical view of the otoliths-as flat plates of fairly uniform receptors activated by linear acceleration dragging on otoconia and so deflecting the receptor hair bundles-has been replaced by new anatomical and physiological evidence which shows that the maculae are much more complex. There is anatomical spatial differentiation across the macula in terms of receptor types, hair bundle heights, stiffness and attachment to the overlying otolithic membrane. This anatomical spatial differentiation corresponds to the neural spatial differentiation of response dynamics from the receptors and afferents from different regions of the otolithic maculae. Specifically, receptors in a specialized band of cells, the striola, are predominantly type I receptors, with short, stiff hair bundles and looser attachment to the overlying otoconial membrane than extrastriolar receptors. At the striola the hair bundles project into holes in the otolithic membrane, allowing for fluid displacement to deflect the hair bundles and activate the cell. This review shows the anatomical and physiological evidence supporting the hypothesis that fluid displacement, generated by sound or vibration, deflects the short stiff hair bundles of type I receptors at the striola, resulting in neural activation of the irregular afferents innervating them. So these afferents are activated by sound or vibration and show phase-locking to individual cycles of the sound or vibration stimulus up to frequencies above 2000 Hz, underpinning the use of sound and vibration for clinical tests of vestibular function.

H2S Regulates Hypobaric Hypoxia-Induced Early Glio-Vascular Dysfunction and Neuro-Pathophysiological Effects

PubMed Central

Kumar, Gaurav; Chhabra, Aastha; Mishra, Shalini; Kalam, Haroon; Kumar, Dhiraj; Meena, Ramniwas; Ahmad, Yasmin; Bhargava, Kalpana; Prasad, Dipti N.; Sharma, Manish

2016-01-01

Hypobaric Hypoxia (HH) is an established risk factor for various neuro-physiological perturbations including cognitive impairment. The origin and mechanistic basis of such responses however remain elusive. We here combined systems level analysis with classical neuro-physiological approaches, in a rat model system, to understand pathological responses of brain to HH. Unbiased ‘statistical co-expression networks’ generated utilizing temporal, differential transcriptome signatures of hippocampus—centrally involved in regulating cognition—implicated perturbation of Glio-Vascular homeostasis during early responses to HH, with concurrent modulation of vasomodulatory, hemostatic and proteolytic processes. Further, multiple lines of experimental evidence from ultra-structural, immuno-histological, substrate-zymography and barrier function studies unambiguously supported this proposition. Interestingly, we show a significant lowering of H2S levels in the brain, under chronic HH conditions. This phenomenon functionally impacted hypoxia-induced modulation of cerebral blood flow (hypoxic autoregulation) besides perturbing the strength of functional hyperemia responses. The augmentation of H2S levels, during HH conditions, remarkably preserved Glio-Vascular homeostasis and key neuro-physiological functions (cerebral blood flow, functional hyperemia and spatial memory) besides curtailing HH-induced neuronal apoptosis in hippocampus. Our data thus revealed causal role of H2S during HH-induced early Glio-Vascular dysfunction and consequent cognitive impairment. PMID:27211559

The Act of Answering Questions Elicited Differentiated Responses in a Concealed Information Test.

PubMed

Otsuka, Takuro; Mizutani, Mitsuyoshi; Yagi, Akihiro; Katayama, Jun'ichi

2018-04-17

The concealed information test (CIT), a psychophysiological detection of deception test, compares physiological responses between crime-related and crime-unrelated items. In previous studies, whether the act of answering questions affected physiological responses was unclear. This study examined effects of both question-related and answer-related processes on physiological responses. Twenty participants received a modified CIT, in which the interval between presentation of questions and answering them was 27 s. Differentiated respiratory movements and cardiovascular responses between items were observed for both questions (items) and answers, while differentiated skin conductance response was observed only for questions. These results suggest that physiological responses to questions reflected orientation to a crime-related item, while physiological responses during answering reflected inhibition of psychological arousal caused by orienting. Regarding the CIT's accuracy, participants' perception of the questions themselves more strongly influenced physiological responses than answering them. © 2018 American Academy of Forensic Sciences.

Cardiac damage in athlete's heart: When the "supernormal" heart fails!

PubMed

Carbone, Andreina; D'Andrea, Antonello; Riegler, Lucia; Scarafile, Raffaella; Pezzullo, Enrica; Martone, Francesca; America, Raffaella; Liccardo, Biagio; Galderisi, Maurizio; Bossone, Eduardo; Calabrò, Raffaele

2017-06-26

Intense exercise may cause heart remodeling to compensate increases in blood pressure or volume by increasing muscle mass. Cardiac changes do not involve only the left ventricle, but all heart chambers. Physiological cardiac modeling in athletes is associated with normal or enhanced cardiac function, but recent studies have documented decrements in left ventricular function during intense exercise and the release of cardiac markers of necrosis in athlete's blood of uncertain significance. Furthermore, cardiac remodeling may predispose athletes to heart disease and result in electrical remodeling, responsible for arrhythmias. Athlete's heart is a physiological condition and does not require a specific treatment. In some conditions, it is important to differentiate the physiological adaptations from pathological conditions, such as hypertrophic cardiomyopathy, arrhythmogenic dysplasia of the right ventricle, and non-compaction myocardium, for the greater risk of sudden cardiac death of these conditions. Moreover, some drugs and performance-enhancing drugs can cause structural alterations and arrhythmias, therefore, their use should be excluded.

Cardiac damage in athlete’s heart: When the “supernormal” heart fails!

PubMed Central

Carbone, Andreina; D’Andrea, Antonello; Riegler, Lucia; Scarafile, Raffaella; Pezzullo, Enrica; Martone, Francesca; America, Raffaella; Liccardo, Biagio; Galderisi, Maurizio; Bossone, Eduardo; Calabrò, Raffaele

2017-01-01

Intense exercise may cause heart remodeling to compensate increases in blood pressure or volume by increasing muscle mass. Cardiac changes do not involve only the left ventricle, but all heart chambers. Physiological cardiac modeling in athletes is associated with normal or enhanced cardiac function, but recent studies have documented decrements in left ventricular function during intense exercise and the release of cardiac markers of necrosis in athlete’s blood of uncertain significance. Furthermore, cardiac remodeling may predispose athletes to heart disease and result in electrical remodeling, responsible for arrhythmias. Athlete’s heart is a physiological condition and does not require a specific treatment. In some conditions, it is important to differentiate the physiological adaptations from pathological conditions, such as hypertrophic cardiomyopathy, arrhythmogenic dysplasia of the right ventricle, and non-compaction myocardium, for the greater risk of sudden cardiac death of these conditions. Moreover, some drugs and performance-enhancing drugs can cause structural alterations and arrhythmias, therefore, their use should be excluded. PMID:28706583

SP and KLF Transcription Factors in Digestive Physiology and Diseases.

PubMed

Kim, Chang-Kyung; He, Ping; Bialkowska, Agnieszka B; Yang, Vincent W

2017-06-01

Specificity proteins (SPs) and Krüppel-like factors (KLFs) belong to the family of transcription factors that contain conserved zinc finger domains involved in binding to target DNA sequences. Many of these proteins are expressed in different tissues and have distinct tissue-specific activities and functions. Studies have shown that SPs and KLFs regulate not only physiological processes such as growth, development, differentiation, proliferation, and embryogenesis, but pathogenesis of many diseases, including cancer and inflammatory disorders. Consistently, these proteins have been shown to regulate normal functions and pathobiology in the digestive system. We review recent findings on the tissue- and organ-specific functions of SPs and KLFs in the digestive system including the oral cavity, esophagus, stomach, small and large intestines, pancreas, and liver. We provide a list of agents under development to target these proteins. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Cell death at the intestinal epithelial front line.

PubMed

Delgado, Maria Eugenia; Grabinger, Thomas; Brunner, Thomas

2016-07-01

The intestinal epithelium represents the largest epithelial surface in our body. This single-cell-layer epithelium mediates important functions in the absorption of nutrients and in the maintenance of barrier function, preventing luminal microorganisms from invading the body. Due to its constant regeneration the intestinal epithelium is a tissue not only with very high proliferation rates but also with very prominent physiological and pathophysiological cell death induction. The normal physiological differentiation and maturation of intestinal epithelial cells leads to their shedding and apoptotic cell death within a few days, without disturbing the epithelial barrier integrity. In contrast excessive intestinal epithelial cell death induced by irradiation, drugs and inflammation severely impairs the vital functions of this tissue. In this review we discuss cell death processes in the intestinal epithelium in health and disease, with special emphasis on cell death triggered by the tumour necrosis factor receptor family. © 2015 FEBS.

Three-Dimensional Cell Culture Models for Infectious Disease and Drug Development

NASA Technical Reports Server (NTRS)

Nickerson, Cheryl A.; Honer zu Bentrup, Kerstin; Ott, C. Mark

2005-01-01

Three-dimensional (3-D) cell cultures hold enormous potential to advance our understanding of infectious disease and to effectively translate basic cellular research into clinical applications. Using novel NASA bioreactor technology, the rotating wall vessel (RWV), we have engineered physiologically relevant 3-D human tissue culture models for infectious disease studies. The design of the RWV is based on the understanding that organs and tissues function in a 3-D environment, and that this 3-D architecture is critical for the differentiated form and function of tissues in vivo. The RWV provides large numbers of cells which are amenable to a wide variety of experimental manipulations and provides an easy, reproducible, and cost-effective approach to enhance differentiated features of cell culture models.

Genome-wide methylation and gene expression changes in newborn rats following maternal protein restriction and reversal by folic acid.

PubMed

Altobelli, Gioia; Bogdarina, Irina G; Stupka, Elia; Clark, Adrian J L; Langley-Evans, Simon

2013-01-01

A large body of evidence from human and animal studies demonstrates that the maternal diet during pregnancy can programme physiological and metabolic functions in the developing fetus, effectively determining susceptibility to later disease. The mechanistic basis of such programming is unclear but may involve resetting of epigenetic marks and fetal gene expression. The aim of this study was to evaluate genome-wide DNA methylation and gene expression in the livers of newborn rats exposed to maternal protein restriction. On day one postnatally, there were 618 differentially expressed genes and 1183 differentially methylated regions (FDR 5%). The functional analysis of differentially expressed genes indicated a significant effect on DNA repair/cycle/maintenance functions and of lipid, amino acid metabolism and circadian functions. Enrichment for known biological functions was found to be associated with differentially methylated regions. Moreover, these epigenetically altered regions overlapped genetic loci associated with metabolic and cardiovascular diseases. Both expression changes and DNA methylation changes were largely reversed by supplementing the protein restricted diet with folic acid. Although the epigenetic and gene expression signatures appeared to underpin largely different biological processes, the gene expression profile of DNA methyl transferases was altered, providing a potential link between the two molecular signatures. The data showed that maternal protein restriction is associated with widespread differential gene expression and DNA methylation across the genome, and that folic acid is able to reset both molecular signatures.

In vitro Differentiation of Functional Human Skeletal Myotubes in a Defined System

PubMed Central

Guo, Xiufang; Greene, Keshel; Akanda, Nesar; Smith, Alec; Stancescu, Maria; Lambert, Stephen; Vandenburgh, Herman; Hickman, James

2013-01-01

In vitro human skeletal muscle systems are valuable tools for the study of human muscular development, disease and treatment. However, published in vitro human muscle systems have so far only demonstrated limited differentiation capacities. Advanced differentiation features such as cross-striations and contractility have only been observed in co-cultures with motoneurons. Furthermore, it is commonly regarded that cultured human myotubes do not spontaneously contract, and any contraction has been considered to originate from innervation. This study developed a serum-free culture system in which human skeletal myotubes demonstrated advanced differentiation. Characterization by immunocytochemistry, electrophysiology and analysis of contractile function revealed these major features: A) well defined sarcomeric development, as demonstrated by the presence of cross-striations. B) finely developed excitation-contraction coupling apparatus characterized by the close apposition of dihydropyridine receptors on T-tubules and Ryanodine receptors on sarcoplasmic reticulum membranes. C) spontaneous and electrically controlled contractility. This report not only demonstrates an improved level of differentiation of cultured human skeletal myotubes, but also provides the first published evidence that such myotubes are capable of spontaneous contraction. Use of this functional in vitro human skeletal muscle system would advance studies concerning human skeletal muscle development and physiology, as well as muscle-related disease and therapy. PMID:24516722

In vitro Differentiation of Functional Human Skeletal Myotubes in a Defined System.

PubMed

Guo, Xiufang; Greene, Keshel; Akanda, Nesar; Smith, Alec; Stancescu, Maria; Lambert, Stephen; Vandenburgh, Herman; Hickman, James

2014-01-01

In vitro human skeletal muscle systems are valuable tools for the study of human muscular development, disease and treatment. However, published in vitro human muscle systems have so far only demonstrated limited differentiation capacities. Advanced differentiation features such as cross-striations and contractility have only been observed in co-cultures with motoneurons. Furthermore, it is commonly regarded that cultured human myotubes do not spontaneously contract, and any contraction has been considered to originate from innervation. This study developed a serum-free culture system in which human skeletal myotubes demonstrated advanced differentiation. Characterization by immunocytochemistry, electrophysiology and analysis of contractile function revealed these major features: A) well defined sarcomeric development, as demonstrated by the presence of cross-striations. B) finely developed excitation-contraction coupling apparatus characterized by the close apposition of dihydropyridine receptors on T-tubules and Ryanodine receptors on sarcoplasmic reticulum membranes. C) spontaneous and electrically controlled contractility. This report not only demonstrates an improved level of differentiation of cultured human skeletal myotubes, but also provides the first published evidence that such myotubes are capable of spontaneous contraction. Use of this functional in vitro human skeletal muscle system would advance studies concerning human skeletal muscle development and physiology, as well as muscle-related disease and therapy.

snoU6 and 5S RNAs are not reliable miRNA reference genes in neuronal differentiation.

PubMed

Lim, Q E; Zhou, L; Ho, Y K; Wan, G; Too, H P

2011-12-29

Accurate profiling of microRNAs (miRNAs) is an essential step for understanding the functional significance of these small RNAs in both physiological and pathological processes. Quantitative real-time PCR (qPCR) has gained acceptance as a robust and reliable transcriptomic method to profile subtle changes in miRNA levels and requires reference genes for accurate normalization of gene expression. 5S and snoU6 RNAs are commonly used as reference genes in microRNA quantification. It is currently unknown if these small RNAs are stably expressed during neuronal differentiation. Panels of miRNAs have been suggested as alternative reference genes to 5S and snoU6 in various physiological contexts. To test the hypothesis that miRNAs may serve as stable references during neuronal differentiation, the expressions of eight miRNAs, 5S and snoU6 RNAs in five differentiating neuronal cell types were analyzed using qPCR. The stabilities of the expressions were evaluated using two complementary statistical approaches (geNorm and Normfinder). Expressions of 5S and snoU6 RNAs were stable under some but not all conditions of neuronal differentiation and thus are not suitable reference genes. In contrast, a combination of three miRNAs (miR-103, miR-106b and miR-26b) allowed accurate expression normalization across different models of neuronal differentiation. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Adenylyl cyclases in the digestive system.

PubMed

Sabbatini, Maria Eugenia; Gorelick, Fred; Glaser, Shannon

2014-06-01

Adenylyl cyclases (ACs) are a group of widely distributed enzymes whose functions are very diverse. There are nine known transmembrane AC isoforms activated by Gαs. Each has its own pattern of expression in the digestive system and differential regulation of function by Ca(2+) and other intracellular signals. In addition to the transmembrane isoforms, one AC is soluble and exhibits distinct regulation. In this review, the basic structure, regulation and physiological roles of ACs in the digestive system are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

Adenylyl cyclases in the digestive system

PubMed Central

Sabbatini, Maria Eugenia; Gorelick, Fred; Glaser, Shannon

2015-01-01

Adenylyl cyclases (ACs) are a group of widely distributed enzymes whose functions are very diverse. There are nine known transmembrane AC isoforms activated by Gαs. Each has its own pattern of expression in the digestive system and differential regulation of function by Ca2+ and other intracellular signals. In addition to the transmembrane isoforms, one AC is soluble and exhibits distinct regulation. In this review, the basic structure, regulation and physiological roles of ACs in the digestive system are discussed. PMID:24521753

Expression of regulatory proteins in choroid plexus changes in early stages of Alzheimer disease.

PubMed

Krzyzanowska, Agnieszka; García-Consuegra, Inés; Pascual, Consuelo; Antequera, Desiree; Ferrer, Isidro; Carro, Eva

2015-04-01

Recent studies indicate that the choroid plexus has important physiologic and pathologic roles in Alzheimer disease (AD). To obtain additional insight on choroid plexus function, we performed a proteomic analysis of choroid plexus samples from patients with AD stages I to II (n = 16), III to IV (n = 16), and V to VI (n = 11) and 7 age-matched control subjects. We used 2-dimensional differential gel electrophoresis coupled with mass spectrometry to generate a complete picture of changes in choroid plexus protein expression occurring in AD patients. We identified 6 proteins: 14-3-3 β/α, 14-3-3 ε, moesin, proteasome activator complex subunit 1, annexin V, and aldehyde dehydrogenase, which were significantly regulated in AD patient samples (p < 0.05, >1.5-fold variation in expression vs control samples). These proteins are implicated in major physiologic functions including mitochondrial dysfunction and apoptosis regulation. These findings contribute additional significance to the emerging importance of molecular and functional changes of choroid plexus function in the pathophysiology of AD.

Influence of late-life exposure to environmental enrichmentor exercise on hippocampal function and CA1 senescent physiology

PubMed Central

Kumar, A.; Rani, A.; Tchigranova, Olga; Lee, Wei-Hua; Foster, T.C.

2011-01-01

Aged (20–22 months) male Fischer 344 rats were randomly assigned to sedentary (A-SED), environmentally enriched (A-ENR) or exercise (A-EX) conditions. After 10–12 weeks of differential experience, the three groups of aged rats and young sedentary controls were tested for physical and cognitive function. Spatial discrimination learning and memory consolidation, tested on the water maze, were enhanced in A-ENR compared to A-SED. A-EX exhibited improved and impaired performance on the cue and spatial task, respectively. Impaired spatial learning in A-EX was likely due to a bias in response selection associated with exercise training, as object recognition memory improved for A-EX rats. An examination of senescent hippocampal physiology revealed that enrichment and exercise reversed age-related changes in long-term depression (LTD) and long-term potentiation (LTP). Rats in the enrichment group exhibited an increase in cell excitability compared to the other two groups of aged animals. The results indicate that differential experience biased the selection of a spatial or a response strategy and factors common across the two conditions, such as increased hippocampal activity associated with locomotion, contribute to reversal of senescent synaptic plasticity. PMID:21820213

Insight into the molecular and functional diversity of cnidarian neuropeptides.

PubMed

Takahashi, Toshio; Takeda, Noriyo

2015-01-23

Cnidarians are the most primitive animals to possess a nervous system. This phylum is composed of the classes Scyphozoa (jellyfish), Cubozoa (box jellyfish), and Hydrozoa (e.g., Hydra, Hydractinia), which make up the subphylum Medusozoa, as well as the class Anthozoa (sea anemones and corals). Neuropeptides have an early evolutionary origin and are already abundant in cnidarians. For example, from the cnidarian Hydra, a key model system for studying the peptides involved in developmental and physiological processes, we identified a wide variety of novel neuropeptides from Hydra magnipapillata (the Hydra Peptide Project). Most of these peptides act directly on muscle cells and induce contraction and relaxation. Some peptides are involved in cell differentiation and morphogenesis. In this review, we describe FMRFamide-like peptides (FLPs), GLWamide-family peptides, and the neuropeptide Hym-355; FPQSFLPRGamide. Several hundred FLPs have been isolated from invertebrate animals such as cnidarians. GLWamide-family peptides function as signaling molecules in muscle contraction, metamorphosis, and settlement in cnidarians. Hym-355; FPQSFLPRGamide enhances neuronal differentiation in Hydra. Recently, GLWamide-family peptides and Hym-355; FPQSFLPRGamide were shown to trigger oocyte maturation and subsequent spawning in the hydrozoan jellyfish Cytaeis uchidae. These findings suggest the importance of these neuropeptides in both developmental and physiological processes.

Unperturbed vs. post-transplantation hematopoiesis: both in vivo but different

PubMed Central

Busch, Katrin; Rodewald, Hans-Reimer

2016-01-01

Purpose of review Hematopoietic stem cell (HSC) transplantation has yielded tremendous information on experimental properties of HSCs. Yet, it remains unclear whether transplantation reflects the physiology of hematopoiesis. A limitation is the difficulty in accessing HSC functions without isolation, in-vitro manipulation and readout for potential. New genetic fate mapping and clonal marking techniques now shed light on hematopoiesis under physiological conditions. Recent findings Transposon-based genetic marks were introduced across the entire hematopoietic system to follow the clonal dynamics of these tags over time. A polyclonal source downstream from stem cells was found responsible for the production of at least granulocytes. In independent experiments, HSCs were genetically marked in adult mice, and the kinetics of label emergence throughout the system was followed over time. These experiments uncovered that during physiological steady-state hematopoiesis large numbers of HSCs yield differentiated progeny. Individual HSCs were active only rarely, indicating their very slow periodicity of differentiation rather than quiescence. Summary Noninvasive genetic experiments in mice have identified a major role of stem and progenitor cells downstream from HSCs as drivers of adult hematopoiesis, and revealed that post-transplantation hematopoiesis differs quantitatively from normal steady-state hematopoiesis. PMID:27213498

The role of echocardiography in the evaluation of cardiac re-modelling and differentiation between physiological and pathological hypertrophy in teenagers engaged in competitive amateur sports.

PubMed

Sulovic, Ljiljana S; Mahmutovic, Meho; Lazic, Snezana; Sulovic, Nenad

2017-05-01

Aims "Athlete's heart" is a cardiac adaptation to long-term intensive training. The aims of this study were to show the prevalence of left ventricular hypertrophy in teenagers who participate in sports, to define the different types of cardiac re-modelling, and to differentiate between physiological and pathological hypertrophy. Echocardiographic measurements were obtained by M-mode, two dimensional, and Doppler techniques of participants from sports and control groups. The echocardiographic examinations included 100 healthy teenagers taking part in dynamic sports such as football and basketball and 100 healthy teenagers taking part in static sports such as karate and judo. The control group (n=100) included healthy, sedentary teenagers. Sports participants had significantly higher left ventricular mass when compared with the control group, (p0.05). Respondents from both groups had E/A ratios (transmitral flow velocity ratio)>1, preserved diastolic function, and statistically they did not differ from the control group. Echocardiographic parameters show that physiological hypertrophy and cardiac re-modelling are present in teenagers who play sports. Unexpectedly, the prevalence of concentric and eccentric types of re-modelling is equally possible in the group of static sports participants.

Differential behavioral and physiological effects of anodal transcranial direct current stimulation in healthy adults of younger and older age

PubMed Central

Heise, Kirstin-Friederike; Niehoff, Martina; Feldheim, J.-F.; Liuzzi, Gianpiero; Gerloff, Christian; Hummel, Friedhelm C.

2014-01-01

Changes in γ-aminobutyric acid (GABA) mediated synaptic transmission have been associated with age-related motor and cognitive functional decline. Since anodal transcranial direct current stimulation (atDCS) has been suggested to target cortical GABAergic inhibitory interneurons, its potential for the treatment of deficient inhibitory activity and functional decline is being increasingly discussed. Therefore, after-effects of a single session of atDCS on resting-state and event-related short-interval intracortical inhibition (SICI) as evaluated with double-pulse TMS and dexterous manual performance were examined using a sham-controlled cross-over design in a sample of older and younger participants. The atDCS effect on resting-state inhibition differed in direction, magnitude, and timing, i.e., late relative release of inhibition in the younger and early relative increase in inhibition in the older. More pronounced release of event-related inhibition after atDCS was exclusively seen in the older. Event-related modulation of inhibition prior to stimulation predicted the magnitude of atDCS-induced effects on resting-state inhibition. Specifically, older participants with high modulatory capacity showed a disinhibitory effect comparable to the younger. Beneficial effects on behavior were mainly seen in the older and in tasks requiring higher dexterity, no clear association with physiological changes was found. Differential effects of atDCS on SICI, discussed to reflect GABAergic inhibition at the level of the primary motor cortex, might be distinct in older and younger participants depending on the functional integrity of the underlying neural network. Older participants with preserved modulatory capacity, i.e., a physiologically “young” motor network, were more likely to show a disinhibitory effect of atDCS. These results favor individually tailored application of tDCS with respect to specific target groups. PMID:25071555

Putative roles of neuropeptides in vagal afferent signaling

PubMed Central

de Lartigue, Guillaume

2014-01-01

The vagus nerve is a major pathway by which information is communicated between the brain and peripheral organs. Sensory neurons of the vagus are located in the nodose ganglia. These vagal afferent neurons innervate the heart, the lung and the gastrointestinal tract, and convey information about peripheral signals to the brain important in the control of cardiovascular tone, respiratory tone, and satiation, respectively. Glutamate is thought to be the primary neurotransmitter involved in conveying all of this information to the brain. It remains unclear how a single neurotransmitter can regulate such an extensive list of physiological functions from a wide range of visceral sites. Many neurotransmitters have been identified in vagal afferent neurons and have been suggested to modulate the physiological functions of glutamate. Specifically, the anorectic peptide transmitters, cocaine and amphetamine regulated transcript (CART) and the orexigenic peptide transmitters, melanin concentrating hormone (MCH) are differentially regulated in vagal afferent neurons and have opposing effects on food intake. Using these two peptides as a model, this review will discuss the potential role of peptide transmitters in providing a more precise and refined modulatory control of the broad physiological functions of glutamate, especially in relation to the control of feeding. PMID:24650553

(Re)Building a Kidney

PubMed Central

Carroll, Thomas J.; Cleaver, Ondine; Gossett, Daniel R.; Hoshizaki, Deborah K.; Hubbell, Jeffrey A.; Humphreys, Benjamin D.; Jain, Sanjay; Jensen, Jan; Kaplan, David L.; Kesselman, Carl; Ketchum, Christian J.; Little, Melissa H.; McMahon, Andrew P.; Shankland, Stuart J.; Spence, Jason R.; Valerius, M. Todd; Wertheim, Jason A.; Wessely, Oliver; Zheng, Ying; Drummond, Iain A.

2017-01-01

(Re)Building a Kidney is a National Institute of Diabetes and Digestive and Kidney Diseases-led consortium to optimize approaches for the isolation, expansion, and differentiation of appropriate kidney cell types and the integration of these cells into complex structures that replicate human kidney function. The ultimate goals of the consortium are two-fold: to develop and implement strategies for in vitro engineering of replacement kidney tissue, and to devise strategies to stimulate regeneration of nephrons in situ to restore failing kidney function. Projects within the consortium will answer fundamental questions regarding human gene expression in the developing kidney, essential signaling crosstalk between distinct cell types of the developing kidney, how to derive the many cell types of the kidney through directed differentiation of human pluripotent stem cells, which bioengineering or scaffolding strategies have the most potential for kidney tissue formation, and basic parameters of the regenerative response to injury. As these projects progress, the consortium will incorporate systematic investigations in physiologic function of in vitro and in vivo differentiated kidney tissue, strategies for engraftment in experimental animals, and development of therapeutic approaches to activate innate reparative responses. PMID:28096308

Translational neurocardiology: preclinical models and cardioneural integrative aspects.

PubMed

Ardell, J L; Andresen, M C; Armour, J A; Billman, G E; Chen, P-S; Foreman, R D; Herring, N; O'Leary, D S; Sabbah, H N; Schultz, H D; Sunagawa, K; Zucker, I H

2016-07-15

Neuronal elements distributed throughout the cardiac nervous system, from the level of the insular cortex to the intrinsic cardiac nervous system, are in constant communication with one another to ensure that cardiac output matches the dynamic process of regional blood flow demand. Neural elements in their various 'levels' become differentially recruited in the transduction of sensory inputs arising from the heart, major vessels, other visceral organs and somatic structures to optimize neuronal coordination of regional cardiac function. This White Paper will review the relevant aspects of the structural and functional organization for autonomic control of the heart in normal conditions, how these systems remodel/adapt during cardiac disease, and finally how such knowledge can be leveraged in the evolving realm of autonomic regulation therapy for cardiac therapeutics. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Functional maintenance of differentiated embryoid bodies in microfluidic systems: a platform for personalized medicine.

PubMed

Guven, Sinan; Lindsey, Jennifer S; Poudel, Ishwari; Chinthala, Sireesha; Nickerson, Michael D; Gerami-Naini, Behzad; Gurkan, Umut A; Anchan, Raymond M; Demirci, Utkan

2015-03-01

Hormone replacement therapies have become important for treating diseases such as premature ovarian failure or menopausal complications. The clinical use of bioidentical hormones might significantly reduce some of the potential risks reportedly associated with the use of synthetic hormones. In the present study, we demonstrate the utility and advantage of a microfluidic chip culture system to enhance the development of personalized, on-demand, treatment modules using embryoid bodies (EBs). Functional EBs cultured on microfluidic chips represent a platform for personalized, patient-specific treatment cassettes that can be cryopreserved until required for treatment. We assessed the viability, differentiation, and functionality of EBs cultured and cryopreserved in this system. During extended microfluidic culture, estradiol, progesterone, testosterone, and anti-müllerian hormone levels were measured, and the expression of differentiated steroidogenic cells was confirmed by immunocytochemistry assay for the ovarian tissue markers anti-müllerian hormone receptor type II, follicle-stimulating hormone receptor, and inhibin β-A and the estrogen biosynthesis enzyme aromatase. Our studies showed that under microfluidic conditions, differentiated steroidogenic EBs continued to secrete estradiol and progesterone at physiologically relevant concentrations (30-120 pg/ml and 150-450 pg/ml, respectively) for up to 21 days. Collectively, we have demonstrated for the first time the feasibility of using a microfluidic chip system with continuous flow for the differentiation and extended culture of functional steroidogenic stem cell-derived EBs, the differentiation of EBs into cells expressing ovarian antigens in a microfluidic system, and the ability to cryopreserve this system with restoration of growth and functionality on thawing. These results present a platform for the development of a new therapeutic system for personalized medicine. ©AlphaMed Press.

Minireview: The Role of Nuclear Receptors in Photoreceptor Differentiation and Disease

PubMed Central

Swaroop, Anand

2012-01-01

Rod and cone photoreceptors are specialized sensory cells that mediate vision. Transcriptional controls are critical for the development and long-term survival of photoreceptors; when these controls become ineffective, retinal dysfunction or degenerative disease may result. This review discusses the role of nuclear receptors, a class of ligand-regulated transcription factors, at key stages of photoreceptor life in the mammalian retina. Nuclear receptors with known ligands, such as retinoids or thyroid hormone, together with several orphan receptors without identified physiological ligands, complement other classes of transcription factors in directing the differentiation and functional maintenance of photoreceptors. The potential of nuclear receptors to respond to ligands introduces versatility into the control of photoreceptor development and function and may suggest new opportunities for treatments of photoreceptor disease. PMID:22556342

Development of a targeted transgenesis strategy in highly differentiated cells: a powerful tool for functional genomic analysis.

PubMed

Puttini, Stefania; Ouvrard-Pascaud, Antoine; Palais, Gael; Beggah, Ahmed T; Gascard, Philippe; Cohen-Tannoudji, Michel; Babinet, Charles; Blot-Chabaud, Marcel; Jaisser, Frederic

2005-03-16

Functional genomic analysis is a challenging step in the so-called post-genomic field. Identification of potential targets using large-scale gene expression analysis requires functional validation to identify those that are physiologically relevant. Genetically modified cell models are often used for this purpose allowing up- or down-expression of selected targets in a well-defined and if possible highly differentiated cell type. However, the generation of such models remains time-consuming and expensive. In order to alleviate this step, we developed a strategy aimed at the rapid and efficient generation of genetically modified cell lines with conditional, inducible expression of various target genes. Efficient knock-in of various constructs, called targeted transgenesis, in a locus selected for its permissibility to the tet inducible system, was obtained through the stimulation of site-specific homologous recombination by the meganuclease I-SceI. Our results demonstrate that targeted transgenesis in a reference inducible locus greatly facilitated the functional analysis of the selected recombinant cells. The efficient screening strategy we have designed makes possible automation of the transfection and selection steps. Furthermore, this strategy could be applied to a variety of highly differentiated cells.

Egr-1 mediated cardiac miR-99 family expression diverges physiological hypertrophy from pathological hypertrophy.

PubMed

Ramasamy, Subbiah; Velmurugan, Ganesan; Rekha, Balakrishnan; Anusha, Sivakumar; Shanmugha Rajan, K; Shanmugarajan, Suresh; Ramprasath, Tharmarajan; Gopal, Pandi; Tomar, Dhanendra; Karthik, Karuppusamy V; Verma, Suresh Kumar; Garikipati, Venkata Naga Srikanth; Sudarsan, Rajan

2018-04-01

The physiological cardiac hypertrophy is an adaptive condition without myocyte cell death, while pathological hypertrophy is a maladaptive condition associated with myocyte cell death. This study explores the miRNome of α-2M-induced physiologically hypertrophied cardiomyocytes and the role of miRNA-99 family during cardiac hypertrophy. Physiological and pathological cardiac hypertrophy was induced in H9c2 cardiomyoblast cell lines using α-2M and isoproterenol respectively. Total RNA isolation and small RNA sequencing were executed for physiological hypertrophy model. The differentially expressed miRNAs and its target mRNAs were validated in animal models. Transcription factor binding sites were predicted in the promoter of specific miRNAs and validated by ChIP-PCR. Subsequently, the selected miRNA was functionally characterized by overexpression and silencing. The effects of silencing of upstream regulator and downstream target gene were studied. Analysis of small RNA reads revealed the differential expression of a large set of miRNAs during hypertrophy, of which miR-99 family was highly downregulated upon α-2M treatment. However, this miR-99 family expression was upregulated during pathological hypertrophy and confirmed in animal models. ChIP-PCR confirms the binding of Egr-1 transcription factor to the miR-99 promoter. Further, silencing of Egr-1 decreased the expression of miR-99. The overexpression or silencing of miR-99 diverges the physiological hypertrophy to pathological hypertrophy and vice versa by regulating Akt-1 pathway. Silencing of Akt-1 replicates the effect of overexpression of miR-99. The results proved Egr-1 mediated regulation of miR-99 family that plays a key role in determining the fate of cardiac hypertrophy by regulating Akt-1 signaling. Copyright © 2018 Elsevier Inc. All rights reserved.

Immunoregulation of follicular renewal, selection, POF, and menopause in vivo, vs. neo-oogenesis in vitro, POF and ovarian infertility treatment, and a clinical trial

PubMed Central

2012-01-01

The immune system plays an important role in the regulation of tissue homeostasis ("tissue immune physiology"). Function of distinct tissues during adulthood, including the ovary, requires (1) Renewal from stem cells, (2) Preservation of tissue-specific cells in a proper differentiated state, which differs among distinct tissues, and (3) Regulation of tissue quantity. Such morphostasis can be executed by the tissue control system, consisting of immune system-related components, vascular pericytes, and autonomic innervation. Morphostasis is established epigenetically, during morphogenetic (developmental) immune adaptation, i.e., during the critical developmental period. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a “stop effect” of resident and self renewing monocyte-derived cells. The later normal tissue is programmed to emerge (e.g., late emergence of ovarian granulosa cells), the earlier its function ceases. Alteration of certain tissue differentiation during the critical developmental period causes persistent alteration of that tissue function, including premature ovarian failure (POF) and primary amenorrhea. In fetal and adult human ovaries the ovarian surface epithelium cells called ovarian stem cells (OSC) are bipotent stem cells for the formation of ovarian germ and granulosa cells. Recently termed oogonial stem cells are, in reality, not stem but already germ cells which have the ability to divide. Immune system-related cells and molecules accompany asymmetric division of OSC resulting in the emergence of secondary germ cells, symmetric division, and migration of secondary germ cells, formation of new granulosa cells and fetal and adult primordial follicles (follicular renewal), and selection and growth of primary/preantral, and dominant follicles. The number of selected follicles during each ovarian cycle is determined by autonomic innervation. Morphostasis is altered with advancing age, due to degenerative changes of the immune system. This causes cessation of oocyte and follicular renewal at 38 +/-2 years of age due to the lack of formation of new granulosa cells. Oocytes in primordial follicles persisting after the end of the prime reproductive period accumulate genetic alterations resulting in an exponentially growing incidence of fetal trisomies and other genetic abnormalities with advanced maternal age. The secondary germ cells also develop in the OSC cultures derived from POF and aging ovaries. In vitro conditions are free of immune mechanisms, which prevent neo-oogenesis in vivo. Such germ cells are capable of differentiating in vitro into functional oocytes. This may provide fresh oocytes and genetically related children to women lacking the ability to produce their own follicular oocytes. Further study of "immune physiology" may help us to better understand ovarian physiology and pathology, including ovarian infertility caused by POF or by a lack of ovarian follicles with functional oocytes in aging ovaries. The observations indicating involvement of immunoregulation in physiological neo-oogenesis and follicular renewal from OSC during the fetal and prime reproductive periods are reviewed as well as immune system and age-independent neo-oogenesis and oocyte maturation in OSC cultures, perimenopausal alteration of homeostasis causing disorders of many tissues, and the first OSC culture clinical trial. PMID:23176151

Towards a Proteomic Catalogue and Differential Annotation of Salivary Gland Proteins in Blood Fed Malaria Vector Anopheles culicifacies by Mass Spectrometry.

PubMed

Rawal, Ritu; Vijay, Sonam; Kadian, Kavita; Singh, Jagbir; Pande, Veena; Sharma, Arun

2016-01-01

In order to understand the importance of functional proteins in mosquito behavior, following blood meal, a baseline proteomic dataset is essential for providing insights into the physiology of blood feeding. Therefore, in this study as first step, in solution and 1-D electrophoresis digestion approach combined with tandem mass spectrometry (nano LC-MS/MS) and computational bioinformatics for data mining was used to prepare a baseline proteomic catalogue of salivary gland proteins of sugar fed An. culicifacies mosquitoes. A total of 106 proteins were identified and analyzed by SEQUEST algorithm against mosquito protein database from Uniprot/NCBI. Importantly, D7r1, D7r2, D7r4, salivary apyrase, anti-platelet protein, calreticulin, antigen 5 family proteins were identified and grouped on the basis of biological and functional roles. Secondly, differential protein expression and annotations between salivary glands of sugar fed vs blood fed mosquitoes was analyzed using 2-Delectrophoresis combined with MALDI-TOF mass spectrometry. The alterations in the differential expression of total 38 proteins was observed out of which 29 proteins like beclin-1, phosphorylating proteins, heme oxygenase 1, ferritin, apoptotic proteins, coagulation and immunity like, serine proteases, serpins, c-type lectin and protein in regulation of blood feeding behavior were found to be up regulated while 9 proteins related to blood feeding, juvenile hormone epoxide hydrolase ii, odorant binding proteins and energy metabolic enzymes were found to be down regulated. To our knowledge, this study provides a first time baseline proteomic dataset and functional annotations of An. culicifacies salivary gland proteins that may be involved during the blood feeding. Identification of differential salivary proteins between sugar fed and blood fed mosquitoes and their plausible role may provide insights into the physiological processes associated with feeding behavior and sporozoite transmission during the process of blood feeding.

Towards a Proteomic Catalogue and Differential Annotation of Salivary Gland Proteins in Blood Fed Malaria Vector Anopheles culicifacies by Mass Spectrometry

PubMed Central

Rawal, Ritu; Vijay, Sonam; Kadian, Kavita; Singh, Jagbir; Pande, Veena; Sharma, Arun

2016-01-01

In order to understand the importance of functional proteins in mosquito behavior, following blood meal, a baseline proteomic dataset is essential for providing insights into the physiology of blood feeding. Therefore, in this study as first step, in solution and 1-D electrophoresis digestion approach combined with tandem mass spectrometry (nano LC-MS/MS) and computational bioinformatics for data mining was used to prepare a baseline proteomic catalogue of salivary gland proteins of sugar fed An. culicifacies mosquitoes. A total of 106 proteins were identified and analyzed by SEQUEST algorithm against mosquito protein database from Uniprot/NCBI. Importantly, D7r1, D7r2, D7r4, salivary apyrase, anti-platelet protein, calreticulin, antigen 5 family proteins were identified and grouped on the basis of biological and functional roles. Secondly, differential protein expression and annotations between salivary glands of sugar fed vs blood fed mosquitoes was analyzed using 2-Delectrophoresis combined with MALDI-TOF mass spectrometry. The alterations in the differential expression of total 38 proteins was observed out of which 29 proteins like beclin-1, phosphorylating proteins, heme oxygenase 1, ferritin, apoptotic proteins, coagulation and immunity like, serine proteases, serpins, c-type lectin and protein in regulation of blood feeding behavior were found to be up regulated while 9 proteins related to blood feeding, juvenile hormone epoxide hydrolase ii, odorant binding proteins and energy metabolic enzymes were found to be down regulated. To our knowledge, this study provides a first time baseline proteomic dataset and functional annotations of An. culicifacies salivary gland proteins that may be involved during the blood feeding. Identification of differential salivary proteins between sugar fed and blood fed mosquitoes and their plausible role may provide insights into the physiological processes associated with feeding behavior and sporozoite transmission during the process of blood feeding. PMID:27602567

Psychosocial versus physiological stress – meta-analyses on deactivations and activations of the neural correlates of stress reactions

PubMed Central

Kogler, Lydia; Mueller, Veronika I.; Chang, Amy; Eickhoff, Simon B.; Fox, Peter T.; Gur, Ruben C.; Derntl, Birgit

2015-01-01

Stress is present in everyday life in various forms and situations. Two stressors frequently investigated are physiological and psychosocial stress. Besides similar subjective and hormonal responses, it has been suggested that they also share common neural substrates. The current study used activation-likelihood-estimation meta-analysis to test this assumption by integrating results of previous neuroimaging studies on stress processing. Reported results are cluster-level FWE corrected. The inferior frontal gyrus (IFG) and the anterior insula (AI) were the only regions that demonstrated overlapping activation for both stressors. Analysis of physiological stress showed consistent activation of cognitive and affective components of pain processing such as the insula, striatum, or the middle cingulate cortex. Contrarily, analysis across psychosocial stress revealed consistent activation of the right superior temporal gyrus and deactivation of the striatum. Notably, parts of the striatum appeared to be functionally specified: the dorsal striatum was activated in physiological stress, whereas the ventral striatum was deactivated in psychosocial stress. Additional functional connectivity and decoding analyses further characterized this functional heterogeneity and revealed higher associations of the dorsal striatum with motor regions and of the ventral striatum with reward processing. Based on our meta-analytic approach, activation of the IFG and the AI seems to indicate a global neural stress reaction. While physiological stress activates a motoric fight-or-flight reaction, during psychosocial stress attention is shifted towards emotion regulation and goal-directed behavior, and reward processing is reduced. Our results show the significance of differentiating physiological and psychosocial stress in neural engagement. Furthermore, the assessment of deactivations in addition to activations in stress research is highly recommended. PMID:26123376

Functional integrative levels in the human interactome recapitulate organ organization.

PubMed

Souiai, Ouissem; Becker, Emmanuelle; Prieto, Carlos; Benkahla, Alia; De las Rivas, Javier; Brun, Christine

2011-01-01

Interactome networks represent sets of possible physical interactions between proteins. They lack spatio-temporal information by construction. However, the specialized functions of the differentiated cell types which are assembled into tissues or organs depend on the combinatorial arrangements of proteins and their physical interactions. Is tissue-specificity, therefore, encoded within the interactome? In order to address this question, we combined protein-protein interactions, expression data, functional annotations and interactome topology. We first identified a subnetwork formed exclusively of proteins whose interactions were observed in all tested tissues. These are mainly involved in housekeeping functions and are located at the topological center of the interactome. This 'Largest Common Interactome Network' represents a 'functional interactome core'. Interestingly, two types of tissue-specific interactions are distinguished when considering function and network topology: tissue-specific interactions involved in regulatory and developmental functions are central whereas tissue-specific interactions involved in organ physiological functions are peripheral. Overall, the functional organization of the human interactome reflects several integrative levels of functions with housekeeping and regulatory tissue-specific functions at the center and physiological tissue-specific functions at the periphery. This gradient of functions recapitulates the organization of organs, from cells to organs. Given that several gradients have already been identified across interactomes, we propose that gradients may represent a general principle of protein-protein interaction network organization.

Syndecan-1 Is Required to Maintain Intradermal Fat and Prevent Cold Stress

PubMed Central

Wollny, Damian; Clark, Rod J.; Roopra, Avtar; Colman, Ricki J.; MacDougald, Ormond A.; Shedd, Timothy A.; Nelson, David W.; Yen, Mei-I; Yen, Chi-Liang Eric; Alexander, Caroline M.

2014-01-01

Homeostatic temperature regulation is fundamental to mammalian physiology and is controlled by acute and chronic responses of local, endocrine and nervous regulators. Here, we report that loss of the heparan sulfate proteoglycan, syndecan-1, causes a profoundly depleted intradermal fat layer, which provides crucial thermogenic insulation for mammals. Mice without syndecan-1 enter torpor upon fasting and show multiple indicators of cold stress, including activation of the stress checkpoint p38α in brown adipose tissue, liver and lung. The metabolic phenotype in mutant mice, including reduced liver glycogen, is rescued by housing at thermoneutrality, suggesting that reduced insulation in cool temperatures underlies the observed phenotypes. We find that syndecan-1, which functions as a facultative lipoprotein uptake receptor, is required for adipocyte differentiation in vitro. Intradermal fat shows highly dynamic differentiation, continuously expanding and involuting in response to hair cycle and ambient temperature. This physiology probably confers a unique role for Sdc1 in this adipocyte sub-type. The PPARγ agonist rosiglitazone rescues Sdc1−/− intradermal adipose tissue, placing PPARγ downstream of Sdc1 in triggering adipocyte differentiation. Our study indicates that disruption of intradermal adipose tissue development results in cold stress and complex metabolic pathology. PMID:25101993

AP-1 proteins in the adult brain: facts and fiction about effectors of neuroprotection and neurodegeneration.

PubMed

Herdegen, T; Waetzig, V

2001-04-30

Jun and Fos proteins are induced and activated following most physiological and pathophysiological stimuli in the brain. Only few data allow conclusions about distinct functions of AP-1 proteins in neurodegeneration and neuroregeneration, and these functions mainly refer to c-Jun and its activation by JNKs. Apoptotic functions of activated c-Jun affect hippocampal, nigral and primary cultured neurons following excitotoxic stimulation and destruction of the neuron-target-axis including withdrawal of trophic molecules. The inhibition of JNKs might exert neuroprotection by subsequent omission of c-Jun activation. Besides endogenous neuronal functions, the c-Jun/AP-1 proteins can damage the nervous system by upregulation of harmful programs in non-neuronal cells (e.g. microglia) with release of neurodegenerative molecules. In contrast, the differentiation with neurite extension and maturation of neural cells in vitro indicate physiological and potentially neuroprotective functions of c-Jun and JNKs including sensoring for alterations in the cytoskeleton. This review summarizes the multiple molecular interfunctions which are involved in the shift from the physiological role to degenerative effects of the Jun/JNK-axis such as cell type-specific expression and intracellular localization of scaffold proteins and upstream activators, antagonistic phosphatases, interaction with other kinase systems, or the activation of transcription factors competing for binding to JNK proteins and AP-1 DNA elements.

Approximating a nonlinear advanced-delayed equation from acoustics

NASA Astrophysics Data System (ADS)

Teodoro, M. Filomena

2016-10-01

We approximate the solution of a particular non-linear mixed type functional differential equation from physiology, the mucosal wave model of the vocal oscillation during phonation. The mathematical equation models a superficial wave propagating through the tissues. The numerical scheme is adapted from the work presented in [1, 2, 3], using homotopy analysis method (HAM) to solve the non linear mixed type equation under study.

ALS/FTLD-linked TDP-43 regulates neurite morphology and cell survival in differentiated neurons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Jeong-Ho; Yu, Tae-Hoon; Ryu, Hyun-Hee

2013-08-01

Tar-DNA binding protein of 43 kDa (TDP-43) has been characterized as a major component of protein aggregates in brains with neurodegenerative diseases such as frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). However, physiological roles of TDP-43 and early cellular pathogenic effects caused by disease associated mutations in differentiated neurons are still largely unknown. Here, we investigated the physiological roles of TDP-43 and the effects of missense mutations associated with diseases in differentiated cortical neurons. The reduction of TDP-43 by siRNA increased abnormal neurites and decreased cell viability. ALS/FTLD-associated missense mutant proteins (A315T, Q331K, and M337V) were partially mislocalizedmore » to the cytosol and neurites when compared to wild-type and showed abnormal neurites similar to those observed in cases of loss of TDP-43. Interestingly, cytosolic expression of wild-type TDP-43 with mutated nuclear localization signals also induced abnormal neurtie morphology and reduction of cell viability. However, there was no significant difference in the effects of cytosolic expression in neuronal morphology and cell toxicity between wild-type and missense mutant proteins. Thus, our results suggest that mislocalization of missense mutant TDP-43 may contribute to loss of TDP-43 function and affect neuronal morphology, probably via dominant negative action before severe neurodegeneration in differentiated cortical neurons. Highlights: • The function of nuclear TDP-43 in neurite morphology in mature neurons. • Partial mislocalization of TDP-43 missense mutants into cytosol from nucleus. • Abnormal neurite morphology caused by missense mutants of TDP-43. • The effect of cytosolic expression of TDP-43 in neurite morphology and in cell survival.« less

Comparative cardiopulmonary effects of size-fractionated airborne particulate matter.

PubMed

Amatullah, Hajera; North, Michelle L; Akhtar, Umme S; Rastogi, Neeraj; Urch, Bruce; Silverman, Frances S; Chow, Chung-Wai; Evans, Greg J; Scott, Jeremy A

2012-02-01

Strong epidemiological evidence exists linking particulate matter (PM) exposures with hospital admissions of individuals for cardiopulmonary symptoms. The PM size is important in influencing the extent of infiltration into the respiratory tract and systemic circulation and directs the differential physiological impacts. To investigate the differential effects of the quasi-ultrafine (PM(0.2)), fine (PM(0.15-2.5)), and coarse PM (PM(2.5-10)) size fractions on pulmonary and cardiac function. Female BALB/c mice were exposed to HEPA-filtered laboratory air or concentrated coarse, fine, or quasi-ultrafine PM using Harvard Ambient Particle Concentrators in conjunction with our nose-only exposure system. These exposures were conducted as part of the "Health Effects of Aerosols in Toronto (HEAT)" campaign. Following a 4 h exposure, mice underwent assessment of respiratory function and recording of electrocardiograms using the flexiVent® system. Exposure to coarse and fine PM resulted in a significant reduction in quasistatic compliance of the lung. Baseline total respiratory resistance and maximum responsiveness to methacholine were augmented after coarse PM exposures but were not affected by quasi-ultrafine PM exposures. In contrast, quasi-ultrafine PM alone had a significant effect on heart rate and in reducing heart rate variability. These findings indicate that coarse and fine PM influence lung function and airways responsiveness, while ultrafine PM can perturb cardiac function. This study supports the hypothesis that coarse and fine PM exerts its predominant physiologic effects at the site of deposition in the airways, whereas ultrafine PM likely crosses the alveolar epithelial barrier into the systemic circulation to affect cardiovascular function.

Uhrf1 is indispensable for normal limb growth by regulating chondrocyte differentiation through specific gene expression.

PubMed

Yamashita, Michiko; Inoue, Kazuki; Saeki, Noritaka; Ideta-Otsuka, Maky; Yanagihara, Yuta; Sawada, Yuichiro; Sakakibara, Iori; Lee, Jiwon; Ichikawa, Koichi; Kamei, Yoshiaki; Iimura, Tadahiro; Igarashi, Katsuhide; Takada, Yasutsugu; Imai, Yuuki

2018-01-08

Transcriptional regulation can be tightly orchestrated by epigenetic regulators. Among these, ubiquitin-like with PHD and RING finger domains 1 (Uhrf1) is reported to have diverse epigenetic functions, including regulation of DNA methylation. However, the physiological functions of Uhrf1 in skeletal tissues remain unclear. Here, we show that limb mesenchymal cell-specific Uhrf1 conditional knockout mice ( Uhrf1 Δ Limb/ Δ Limb ) exhibit remarkably shortened long bones that have morphological deformities due to dysregulated chondrocyte differentiation and proliferation. RNA-seq performed on primary cultured chondrocytes obtained from Uhrf1 Δ Limb/ Δ Limb mice showed abnormal chondrocyte differentiation. In addition, integrative analyses using RNA-seq and MBD-seq revealed that Uhrf1 deficiency decreased genome-wide DNA methylation and increased gene expression through reduced DNA methylation in the promoter regions of 28 genes, including Hspb1 , which is reported to be an IL1-related gene and to affect chondrocyte differentiation. Hspb1 knockdown in cKO chondrocytes can normalize abnormal expression of genes involved in chondrocyte differentiation, such as Mmp13 These results indicate that Uhrf1 governs cell type-specific transcriptional regulation by controlling the genome-wide DNA methylation status and regulating consequent cell differentiation and skeletal maturation. © 2018. Published by The Company of Biologists Ltd.

The origin of pre-neoplastic metaplasia in the stomach: Chief cells emerge from the Mist

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldenring, James R., E-mail: jim.goldenring@vanderbilt.edu; Departments of Surgery and Cell and Developmental Biology, Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN; Nam, Ki Taek

2011-11-15

The digestive-enzyme secreting, gastric epithelial chief (zymogenic) cell is remarkable and underappreciated. Here, we discuss how all available evidence suggests that mature chief cells in the adult, mammalian stomach are postmitotic, slowly turning over cells that arise via a relatively long-lived progenitor, the mucous neck cell, The differentiation of chief cells from neck cells does not involve cell division, and the neck cell has its own distinct pattern of gene expression and putative physiological function. Thus, the ontogeny of the normal chief cell lineage exemplifies transdifferentiation. Furthermore, under pathophysiogical loss of acid-secreting parietal cell, the chief cell lineage can itselfmore » trasndifferentiate into a mucous cell metaplasia designated Spasmolytic Polypeptide Expressing Metaplasia (SPEM). Especially in the presence of inflammation, this metaplastic lineage can regain proliferative capacity and, in humans may also further differentiate into intestinal metaplasia. The results indicate that gastric fundic lineages display remarkable plasticity in both physiological ontogeny and pathophysiological pre-neoplastic metaplasia.« less

New Trends in Aryl Hydrocarbon Receptor Biology.

PubMed

Mulero-Navarro, Sonia; Fernandez-Salguero, Pedro M

2016-01-01

Traditionally considered as a critical intermediate in the toxic and carcinogenic response to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD), the Aryl hydrocarbon/Dioxin receptor (AhR) has proven to be also an important regulator of cell physiology and organ homeostasis. AhR has become an interesting and actual area of research mainly boosted by a significant number of recent studies analyzing its contribution to the proper functioning of the immune, hepatic, cardiovascular, vascular and reproductive systems. At the cellular level, AhR establishes functional interactions with signaling pathways governing cell proliferation and cell cycle, cell morphology, cell adhesion and cell migration. Two exciting new aspects in AhR biology deal with its implication in the control of cell differentiation and its more than likely involvement in cell pluripotency and stemness. In fact, it is possible that AhR could help modulate the balance between differentiation and pluripotency in normal and transformed tumor cells. At the molecular level, AhR regulates an increasingly large array of physiologically relevant genes either by traditional transcription-dependent mechanisms or by unforeseen processes involving genomic insulators, chromatin dynamics and the transcription of mobile genetic elements. AhR is also closely related to epigenetics, not only from the point of view of target gene expression but also with respect to its own regulation by promoter methylation. It is reasonable to consider that deregulation of these many functions could have a causative role, or at least contribute to, human disease. Consequently, several laboratories have proposed that AhR could be a valuable tool as diagnostic marker and/or therapeutic target in human pathologies. An additional point of interest is the possibility of regulating AhR activity by endogenous non-toxic low weight molecules agonist or antagonist molecules that could be present or included in the diet. In this review, we will address these molecular and functional features of AhR biology within physiological and pathological contexts.

Stimulation of GABA-Induced Ca2+ Influx Enhances Maturation of Human Induced Pluripotent Stem Cell-Derived Neurons

PubMed Central

Rushton, David J.; Mattis, Virginia B.; Svendsen, Clive N.; Allen, Nicholas D.; Kemp, Paul J.

2013-01-01

Optimal use of patient-derived, induced pluripotent stem cells for modeling neuronal diseases is crucially dependent upon the proper physiological maturation of derived neurons. As a strategy to develop defined differentiation protocols that optimize electrophysiological function, we investigated the role of Ca2+ channel regulation by astrocyte conditioned medium in neuronal maturation, using whole-cell patch clamp and Ca2+ imaging. Standard control medium supported basic differentiation of induced pluripotent stem cell-derived neurons, as assayed by the ability to fire simple, single, induced action potentials. In contrast, treatment with astrocyte conditioned medium elicited complex and spontaneous neuronal activity, often with rhythmic and biphasic characteristics. Such augmented spontaneous activity correlated with astrocyte conditioned medium-evoked hyperpolarization and was dependent upon regulated function of L-, N- and R-type Ca2+ channels. The requirement for astrocyte conditioned medium could be substituted by simply supplementing control differentiation medium with high Ca2+ or γ-amino butyric acid (GABA). Importantly, even in the absence of GABA signalling, opening Ca2+ channels directly using Bay K8644 was able to hyperpolarise neurons and enhance excitability, producing fully functional neurons. These data provide mechanistic insight into how secreted astrocyte factors control differentiation and, importantly, suggest that pharmacological modulation of Ca2+ channel function leads to the development of a defined protocol for improved maturation of induced pluripotent stem cell-derived neurons. PMID:24278369

Neuropeptides and epitheliopeptides: structural and functional diversity in an ancestral metazoan Hydra.

PubMed

Takahashi, Toshio

2013-06-01

Peptides are known to play important developmental and physiological roles in signaling. The rich diversity of peptides, with functions as diverse as intercellular communication, neurotransmission and signaling that spatially and temporally controls axis formation and cell differentiation, hints at the wealth of information passed between interacting cells. Little is known about peptides that control developmental processes such as cell differentiation and pattern formation in metazoans. The cnidarian Hydra is one of the most basic metazoans and is a key model system for study of the peptides involved in these processes. We developed a novel peptidomic approach for the isolation and identification of functional peptide signaling molecules from Hydra (the Hydra Peptide Project). Over the course of this project, a wide variety of novel neuropeptides were identified. Most of these peptides act directly on muscle cells and their functions include induction of contraction and relaxation. Some peptides are involved in cell differentiation and morphogenesis. Moreover, epitheliopeptides that are produced by epithelial cells were originally identified in Hydra. Some of these epitheliopeptides exhibit morphogen-like activities, whereas others are involved in regulating neuron differentiation, possibly through neuron-epithelial cell interactions. We also describe below our high-throughput reverse-phase nano-flow LCMALDI- TOF-MS/MS approach, which has proved a powerful tool for the discovery of novel peptide signaling molecules in Hydra.

Differential roles of NADPH oxidases in vascular physiology and pathophysiology

PubMed Central

Amanso, Angelica M.; Griendling, Kathy K.

2012-01-01

Reactive oxygen species (ROS) are produced by all vascular cells and regulate the major physiological functions of the vasculature. Production and removal of ROS are tightly controlled and occur in discrete subcellular locations, allowing for specific, compartmentalized signaling. Among the many sources of ROS in the vessel wall, NADPH oxidases are implicated in physiological functions such as control of vasomotor tone, regulation of extracellular matrix and phenotypic modulation of vascular smooth muscle cells. They are involved in the response to injury, whether as an oxygen sensor during hypoxia, as a regulator of protein processing, as an angiogenic stimulus, or as a mechanism of wound healing. These enzymes have also been linked to processes leading to disease development, including migration, proliferation, hypertrophy, apoptosis and autophagy. As a result, NADPH oxidases participate in atherogenesis, systemic and pulmonary hypertension and diabetic vascular disease. The role of ROS in each of these processes and diseases is complex, and a more full understanding of the sources, targets, cell-specific responses and counterbalancing mechanisms is critical for the rational development of future therapeutics. PMID:22202108

Tooth wear: the view of the anthropologist.

PubMed

Kaidonis, John A

2008-03-01

Anthropologists have for many years considered human tooth wear a normal physiological phenomenon where teeth, although worn, remain functional throughout life. Wear was considered pathological only if pulpal exposure or premature tooth loss occurred. In addition, adaptive changes to the stomatognathic system in response to wear have been reported including continual eruption, the widening of the masticatory cycle, remodelling of the temporomandibular joint and the shortening of the dental arches from tooth migration. Comparative studies of many different species have also documented these physiological processes supporting the idea of perpetual change over time. In particular, differential wear between enamel and dentine was considered a physiological process relating to the evolution of the form and function of teeth. Although evidence of attrition and abrasion has been known to exist among hunter-gatherer populations for many thousands of years, the prevalence of erosion in such early populations seems insignificant. In particular, non-carious cervical lesions to date have not been observed within these populations and therefore should be viewed as 'modern-day' pathology. Extrapolating this anthropological perspective to the clinical setting has merits, particularly in the prevention of pre-mature unnecessary treatment.

Classification of lymphoid neoplasms: the microscope as a tool for disease discovery

PubMed Central

Harris, Nancy Lee; Stein, Harald; Isaacson, Peter G.

2008-01-01

In the past 50 years, we have witnessed explosive growth in the understanding of normal and neoplastic lymphoid cells. B-cell, T-cell, and natural killer (NK)–cell neoplasms in many respects recapitulate normal stages of lymphoid cell differentiation and function, so that they can be to some extent classified according to the corresponding normal stage. Likewise, the molecular mechanisms involved the pathogenesis of lymphomas and lymphoid leukemias are often based on the physiology of the lymphoid cells, capitalizing on deregulated normal physiology by harnessing the promoters of genes essential for lymphocyte function. The clinical manifestations of lymphomas likewise reflect the normal function of lymphoid cells in vivo. The multiparameter approach to classification adopted by the World Health Organization (WHO) classification has been validated in international studies as being highly reproducible, and enhancing the interpretation of clinical and translational studies. In addition, accurate and precise classification of disease entities facilitates the discovery of the molecular basis of lymphoid neoplasms in the basic science laboratory. PMID:19029456

Genomic and non-genomic effects of androgens in the cardiovascular system: clinical implications

PubMed Central

Lucas-Herald, Angela K.; Alves-Lopes, Rheure; Montezano, Augusto C.; Ahmed, S. Faisal

2017-01-01

The principle steroidal androgens are testosterone and its metabolite 5α-dihydrotestosterone (DHT), which is converted from testosterone by the enzyme 5α-reductase. Through the classic pathway with androgens crossing the plasma membrane and binding to the androgen receptor (AR) or via mechanisms independent of the ligand-dependent transactivation function of nuclear receptors, testosterone induces genomic and non-genomic effects respectively. AR is widely distributed in several tissues, including vascular endothelial and smooth muscle cells. Androgens are essential for many developmental and physiological processes, especially in male reproductive tissues. It is now clear that androgens have multiple actions besides sex differentiation and sexual maturation and that many physiological systems are influenced by androgens, including regulation of cardiovascular function [nitric oxide (NO) release, Ca2+ mobilization, vascular apoptosis, hypertrophy, calcification, senescence and reactive oxygen species (ROS) generation]. This review focuses on evidence indicating that interplay between genomic and non-genomic actions of testosterone may influence cardiovascular function. PMID:28645930

Mouse ES cells have a potential to differentiate into odontoblast-like cells using hanging drop method.

PubMed

Kawai, R; Ozeki, N; Yamaguchi, H; Tanaka, T; Nakata, K; Mogi, M; Nakamura, H

2014-05-01

We examined whether mouse embryonic stem (ES) cells can differentiate into odontoblast-like cells without epithelial-mesenchymal interaction. Cells were cultured by the 'hanging drop' method using a collagen type-I scaffold (CS) combined with bone morphogenetic protein (BMP)-4 (CS/BMP-4). Expression of odontoblast-related mRNA and protein, and cell proliferation were performed by reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence staining and WST-1 assay, respectively. Cells potently expressed odontoblast-related cell marker mRNAs following induction of odontoblastic differentiation. Dentin sialophosphoprotein, a marker of mature odontoblasts, was strongly expressed in differentiated ES cells. The cells also acquired an odontoblast-like functional phenotype, as evidenced by the appearance of alkaline phosphatase activity and calcification. The cell-surface expression of α2, α6, αV and αVβ3 integrin proteins was rapidly upregulated in differentiated cells. Finally, anti-α2 integrin antibody suppressed the expression of odontoblastic markers in cells grown using this culture system, suggesting that α2 integrin expression in ES cells triggers their differentiation into odontoblast-like cells. Mouse ES cells cultured by the 'hanging drop' method are able to differentiate into cells with odontoblast-specific physiological functions and cell-surface integrin protein expression. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Regulation of immunity and inflammation by hypoxia in immunological niches.

PubMed

Taylor, Cormac T; Colgan, Sean P

2017-12-01

Immunological niches are focal sites of immune activity that can have varying microenvironmental features. Hypoxia is a feature of physiological and pathological immunological niches. The impact of hypoxia on immunity and inflammation can vary depending on the microenvironment and immune processes occurring in a given niche. In physiological immunological niches, such as the bone marrow, lymphoid tissue, placenta and intestinal mucosa, physiological hypoxia controls innate and adaptive immunity by modulating immune cell proliferation, development and effector function, largely via transcriptional changes driven by hypoxia-inducible factor (HIF). By contrast, in pathological immunological niches, such as tumours and chronically inflamed, infected or ischaemic tissues, pathological hypoxia can drive tissue dysfunction and disease development through immune cell dysregulation. Here, we differentiate between the effects of physiological and pathological hypoxia on immune cells and the consequences for immunity and inflammation in different immunological niches. Furthermore, we discuss the possibility of targeting hypoxia-sensitive pathways in immune cells for the treatment of inflammatory disease.

Leaf proteome alterations in the context of physiological and morphological responses to drought and heat stress in barley (Hordeum vulgare L.)

PubMed Central

von Korff, M.

2013-01-01

The objective of this study was to identify barley leaf proteins differentially regulated in response to drought and heat and the combined stresses in context of the morphological and physiological changes that also occur. The Syrian landrace Arta and the Australian cultivar Keel were subjected to drought, high temperature, or a combination of both treatments starting at heading. Changes in the leaf proteome were identified using differential gel electrophoresis and mass spectrometry. The drought treatment caused strong reductions of biomass and yield, while photosynthetic performance and the proteome were not significantly changed. In contrast, the heat treatment and the combination of heat and drought reduced photosynthetic performance and caused changes of the leaf proteome. The proteomic analysis identified 99 protein spots differentially regulated in response to heat treatment, 14 of which were regulated in a genotype-specific manner. Differentially regulated proteins predominantly had functions in photosynthesis, but also in detoxification, energy metabolism, and protein biosynthesis. The analysis indicated that de novo protein biosynthesis, protein quality control mediated by chaperones and proteases, and the use of alternative energy resources, i.e. glycolysis, play important roles in adaptation to heat stress. In addition, genetic variation identified in the proteome, in plant growth and photosynthetic performance in response to drought and heat represent stress adaption mechanisms to be exploited in future crop breeding efforts. PMID:23918963

Regulation of Mammalian Physiology by Interconnected Circadian and Feeding Rhythms

PubMed Central

Atger, Florian; Mauvoisin, Daniel; Weger, Benjamin; Gobet, Cédric; Gachon, Frédéric

2017-01-01

Circadian clocks are endogenous timekeeping systems that adapt in an anticipatory fashion the physiology and behavior of most living organisms. In mammals, the master pacemaker resides in the suprachiasmatic nucleus and entrains peripheral clocks using a wide range of signals that differentially schedule physiology and gene expression in a tissue-specific manner. The peripheral clocks, such as those found in the liver, are particularly sensitive to rhythmic external cues like feeding behavior, which modulate the phase and amplitude of rhythmic gene expression. Consequently, the liver clock temporally tunes the expression of many genes involved in metabolism and physiology. However, the circadian modulation of cellular functions also relies on multiple layers of posttranscriptional and posttranslational regulation. Strikingly, these additional regulatory events may happen independently of any transcriptional oscillations, showing that complex regulatory networks ultimately drive circadian output functions. These rhythmic events also integrate feeding-related cues and adapt various metabolic processes to food availability schedules. The importance of such temporal regulation of metabolism is illustrated by metabolic dysfunctions and diseases resulting from circadian clock disruption or inappropriate feeding patterns. Therefore, the study of circadian clocks and rhythmic feeding behavior should be of interest to further advance our understanding of the prevention and therapy of metabolic diseases. PMID:28337174

Steroids in teleost fishes: A functional point of view.

PubMed

Tokarz, Janina; Möller, Gabriele; Hrabě de Angelis, Martin; Adamski, Jerzy

2015-11-01

Steroid hormones are involved in the regulation of a variety of processes like embryonic development, sex differentiation, metabolism, immune responses, circadian rhythms, stress response, and reproduction in vertebrates. Teleost fishes and humans show a remarkable conservation in many developmental and physiological aspects, including the endocrine system in general and the steroid hormone related processes in particular. This review provides an overview of the current knowledge about steroid hormone biosynthesis and the steroid hormone receptors in teleost fishes and compares the findings to the human system. The impact of the duplicated genome in teleost fishes on steroid hormone biosynthesis and perception is addressed. Additionally, important processes in fish physiology regulated by steroid hormones, which are most dissimilar to humans, are described. We also give a short overview on the influence of anthropogenic endocrine disrupting compounds on steroid hormone signaling and the resulting adverse physiological effects for teleost fishes. By this approach, we show that the steroidogenesis, hormone receptors, and function of the steroid hormones are reasonably well understood when summarizing the available data of all teleost species analyzed to date. However, on the level of a single species or a certain fish-specific aspect of physiology, further research is needed. Copyright © 2015 Elsevier Inc. All rights reserved.

Platelet-rich plasma derived growth factors contribute to stem cell differentiation in musculoskeletal regeneration

NASA Astrophysics Data System (ADS)

Qian, Yun; Han, Qixin; Chen, Wei; Song, Jialin; Zhao, Xiaotian; Ouyang, Yuanming; Yuan, Weien; Fan, Cunyi

2017-10-01

Stem cell treatment and platelet-rich plasma (PRP) therapy are two significant issues in regenerative medicine. Stem cells such as bone marrow mesenchymal stem cells, adipose-derived stem cells and periodontal ligament stem cells can be successfully applied in the field of tissue regeneration. PRP, a natural product isolated from whole blood, can secrete multiple growth factors (GFs) for regulating physiological activities. These GFs can stimulate proliferation and differentiation of different stem cells in injury models. Therefore, combination of both agents receives wide expectations in regenerative medicine, especially in bone, cartilage and tendon repair. In this review, we thoroughly discussed the interaction and underlying mechanisms of platelet-rich plasma derived growth factors with stem cells, and assessed their functions in cell differentiation for musculoskeletal regeneration.

Platelet-Rich Plasma Derived Growth Factors Contribute to Stem Cell Differentiation in Musculoskeletal Regeneration.

PubMed

Qian, Yun; Han, Qixin; Chen, Wei; Song, Jialin; Zhao, Xiaotian; Ouyang, Yuanming; Yuan, Weien; Fan, Cunyi

2017-01-01

Stem cell treatment and platelet-rich plasma (PRP) therapy are two significant issues in regenerative medicine. Stem cells such as bone marrow mesenchymal stem cells, adipose-derived stem cells and periodontal ligament stem cells can be successfully applied in the field of tissue regeneration. PRP, a natural product isolated from whole blood, can secrete multiple growth factors (GFs) for regulating physiological activities. These GFs can stimulate proliferation and differentiation of different stem cells in injury models. Therefore, combination of both agents receives wide expectations in regenerative medicine, especially in bone, cartilage and tendon repair. In this review, we thoroughly discussed the interaction and underlying mechanisms of PRP derived GFs with stem cells, and assessed their functions in cell differentiation for musculoskeletal regeneration.

Sex Differences: A Resultant of an Evolutionary Pressure?

PubMed

Della Torre, Sara; Maggi, Adriana

2017-03-07

Spurred by current research policy, we are witnessing a significant growth in the number of studies that observe and describe sexual diversities in human physiology and sex prevalence in a large number of pathologies. Yet we are far from the comprehension of the mechanisms underpinning these differences, which are the result of a long evolutionary history. This Essay is meant to underline female reproductive function as a driver for the positive selection of the specific physiological features that explain male and female differential susceptibility to diseases and metabolic disturbances, in particular. A clear understanding of the causes underlying sexual dimorphisms in the physio-pathology is crucial for precision medicine. Copyright © 2017 Elsevier Inc. All rights reserved.

Intestinal mucosal atrophy and adaptation

PubMed Central

Shaw, Darcy; Gohil, Kartik; Basson, Marc D

2012-01-01

Mucosal adaptation is an essential process in gut homeostasis. The intestinal mucosa adapts to a range of pathological conditions including starvation, short-gut syndrome, obesity, and bariatric surgery. Broadly, these adaptive functions can be grouped into proliferation and differentiation. These are influenced by diverse interactions with hormonal, immune, dietary, nervous, and mechanical stimuli. It seems likely that clinical outcomes can be improved by manipulating the physiology of adaptation. This review will summarize current understanding of the basic science surrounding adaptation, delineate the wide range of potential targets for therapeutic intervention, and discuss how these might be incorporated into an overall treatment plan. Deeper insight into the physiologic basis of adaptation will identify further targets for intervention to improve clinical outcomes. PMID:23197881

Mammalian lipoxygenases and their biological relevance

PubMed Central

Kuhn, Hartmut; Banthiya, Swathi; van Leyen, Klaus

2015-01-01

Lipoxygenases (LOXs) form a heterogeneous class of lipid peroxidizing enzymes, which have been implicated in cell proliferation and differentiation but also in the pathogenesis of various diseases with major public health relevance. As other fatty acid dioxygenases LOX oxidize polyunsaturated fatty acids to their corresponding hydroperoxy derivatives, which are further transformed to bioactive lipid mediators (eicosanoids and related substances). On the other hand, lipoxygenases are key players in regulation of the cellular redox homeostasis, which is an important element in gene expression regulation. Although the first mammalian lipoxygenases were discovered 40 years ago and although the enzymes have been well characterized with respect to their structural and functional properties the biological roles of the different lipoxygenase isoforms are not completely understood. This review is aimed at summarizing the current knowledge on the physiological roles of different mammalian LOX-isoforms and their patho-physiological function in inflammatory, metabolic, hyperproliferative, neurodegenerative and infectious disorders. PMID:25316652

Structure-activity relationship of crustacean peptide hormones.

PubMed

Katayama, Hidekazu

2016-01-01

In crustaceans, various physiological events, such as molting, vitellogenesis, and sex differentiation, are regulated by peptide hormones. To understanding the functional sites of these hormones, many structure-activity relationship (SAR) studies have been published. In this review, the author focuses the SAR of crustacean hyperglycemic hormone-family peptides and androgenic gland hormone and describes the detailed results of our and other research groups. The future perspectives will be also discussed.

Insight into the Molecular and Functional Diversity of Cnidarian Neuropeptides

PubMed Central

Takahashi, Toshio; Takeda, Noriyo

2015-01-01

Cnidarians are the most primitive animals to possess a nervous system. This phylum is composed of the classes Scyphozoa (jellyfish), Cubozoa (box jellyfish), and Hydrozoa (e.g., Hydra, Hydractinia), which make up the subphylum Medusozoa, as well as the class Anthozoa (sea anemones and corals). Neuropeptides have an early evolutionary origin and are already abundant in cnidarians. For example, from the cnidarian Hydra, a key model system for studying the peptides involved in developmental and physiological processes, we identified a wide variety of novel neuropeptides from Hydra magnipapillata (the Hydra Peptide Project). Most of these peptides act directly on muscle cells and induce contraction and relaxation. Some peptides are involved in cell differentiation and morphogenesis. In this review, we describe FMRFamide-like peptides (FLPs), GLWamide-family peptides, and the neuropeptide Hym-355; FPQSFLPRGamide. Several hundred FLPs have been isolated from invertebrate animals such as cnidarians. GLWamide-family peptides function as signaling molecules in muscle contraction, metamorphosis, and settlement in cnidarians. Hym-355; FPQSFLPRGamide enhances neuronal differentiation in Hydra. Recently, GLWamide-family peptides and Hym-355; FPQSFLPRGamide were shown to trigger oocyte maturation and subsequent spawning in the hydrozoan jellyfish Cytaeis uchidae. These findings suggest the importance of these neuropeptides in both developmental and physiological processes. PMID:25625515

A typology of interpartner conflict and maternal parenting practices in high-risk families: examining spillover and compensatory models and implications for child adjustment.

PubMed

Sturge-Apple, Melissa L; Davies, Patrick T; Cicchetti, Dante; Fittoria, Michael G

2014-11-01

The present study incorporates a person-based approach to identify spillover and compartmentalization patterns of interpartner conflict and maternal parenting practices in an ethnically diverse sample of 192 2-year-old children and their mothers who had experienced higher levels of socioeconomic risk. In addition, we tested whether sociocontextual variables were differentially predictive of theses profiles and examined how interpartner-parenting profiles were associated with children's physiological and psychological adjustment over time. As expected, latent class analyses extracted three primary profiles of functioning: adequate functioning, spillover, and compartmentalizing families. Furthermore, interpartner-parenting profiles were differentially associated with both sociocontextual predictors and children's adjustment trajectories. The findings highlight the developmental utility of incorporating person-based approaches to models of interpartner conflict and maternal parenting practices.

Physiological and molecular responses of Lactuca sativa to colonization by Salmonella enterica serovar Dublin.

PubMed

Klerks, M M; van Gent-Pelzer, M; Franz, E; Zijlstra, C; van Bruggen, A H C

2007-08-01

This paper describes the physiological and molecular interactions between the human-pathogenic organism Salmonella enterica serovar Dublin and the commercially available mini Roman lettuce cv. Tamburo. The association of S. enterica serovar Dublin with lettuce plants was first determined, which indicated the presence of significant populations outside and inside the plants. The latter was evidenced from significant residual concentrations after highly efficient surface disinfection (99.81%) and fluorescence microscopy of S. enterica serovar Dublin in cross sections of lettuce at the root-shoot transition region. The plant biomass was reduced significantly compared to that of noncolonized plants upon colonization with S. enterica serovar Dublin. In addition to the physiological response, transcriptome analysis by cDNA amplified fragment length polymorphism analysis also provided clear differential gene expression profiles between noncolonized and colonized lettuce plants. From these, generally and differentially expressed genes were selected and identified by sequence analysis, followed by reverse transcription-PCR displaying the specific gene expression profiles in time. Functional grouping of the expressed genes indicated a correlation between colonization of the plants and an increase in expressed pathogenicity-related genes. This study indicates that lettuce plants respond to the presence of S. enterica serovar Dublin at physiological and molecular levels, as shown by the reduction in growth and the concurrent expression of pathogenicity-related genes. In addition, it was confirmed that Salmonella spp. can colonize the interior of lettuce plants, thus potentially imposing a human health risk when processed and consumed.

Human neural stem cell-derived cultures in three-dimensional substrates form spontaneously functional neuronal networks.

PubMed

Smith, Imogen; Silveirinha, Vasco; Stein, Jason L; de la Torre-Ubieta, Luis; Farrimond, Jonathan A; Williamson, Elizabeth M; Whalley, Benjamin J

2017-04-01

Differentiated human neural stem cells were cultured in an inert three-dimensional (3D) scaffold and, unlike two-dimensional (2D) but otherwise comparable monolayer cultures, formed spontaneously active, functional neuronal networks that responded reproducibly and predictably to conventional pharmacological treatments to reveal functional, glutamatergic synapses. Immunocytochemical and electron microscopy analysis revealed a neuronal and glial population, where markers of neuronal maturity were observed in the former. Oligonucleotide microarray analysis revealed substantial differences in gene expression conferred by culturing in a 3D vs a 2D environment. Notable and numerous differences were seen in genes coding for neuronal function, the extracellular matrix and cytoskeleton. In addition to producing functional networks, differentiated human neural stem cells grown in inert scaffolds offer several significant advantages over conventional 2D monolayers. These advantages include cost savings and improved physiological relevance, which make them better suited for use in the pharmacological and toxicological assays required for development of stem cell-based treatments and the reduction of animal use in medical research. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Systems Level Approaches to Understanding and Manipulating Heterocyst Differentiation in Nostoc Punctiforme: Sites of Hydrogenase and Nitrogenase Synthesis and Activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meeks, John C.

Heterocysts are specialized cells that establish a physiologically low oxygen concentration; they function as the sites of oxygen-sensitive nitrogen fixation and hydrogen metabolism in certain filamentous cyanobacteria. They are present at a frequency of less than 10% of the cells and singly in a nonrandom spacing pattern in the filaments. The extent of differential gene expression during heterocyst differentiation was defined by DNA microarray analysis in wild type and mutant cultures of Nostoc punctiforme. The results in wild-type cultures identified two groups of genes; approximately 440 that are unique to heterocyst formation and function, and 500 that respond positively andmore » negatively to the transient stress of nitrogen starvation. Nitrogen fixation is initiated within 24 h after induction, but the cultures require another 24 h before growth is reinitiated. Microarray analyses were conducted on strains with altered expression of three genes that regulate the presence and spacing of heterocysts in the filaments; loss of function or over expression of these genes increases the heterocyst frequency 2 to 3 fold compared to the wild-type. Mutations in the genes hetR and hetF result in the inability to differentiate heterocysts, whereas over expression of each gene individually yields multiple contiguous heterocysts at sites in the filaments; they are positive regulatory elements. Mutation of the gene patN results in an increase in heterocysts frequency, but, in this case, the heterocysts are singly spaced in the filaments with a decrease in the number of vegetative cells in the interval between heterocysts; this is a negative regulatory element. However, over expression of patN resulted in the wild-type heterocyst frequency and spacing pattern. Microarray results indicated HetR and HetF influence the transcription of a common set of about 395 genes, as well as about 350 genes unique to each protein. HetR is known to be a transcriptional regulator and HetF is predicted to be a protease, perhaps operating thorough stability of HetR; thus, the influence of HetF on transcription of a unique set of genes was unanticipated. These two proteins are also found in non-heterocyst-forming filamentous cyanobacteria and the results have implications on their other physiological role(s). The PatN protein is unique to heterocyst-forming cyanobacteria. Cytological analysis indicated PatN is present in only one of the two daughter cells following division, but is present in both cell less than 8 h after division. Microarray analysis indicated only five genes were differentially transcribed in the patN mutant compared to the wild type; three up-regulated genes that are known to influence heterocyst differentiation and two down-regulated genes that have an unassigned function. Mutational analyses indicted the two down-regulated genes do not have a distinct role in heterocyst differentiation. Thus, PatN only indirectly impacts transcription. These databases provide lists of differentially transcribed genes involved in nitrogen starvation and cellular differentiation that can be mined for detailed genetic analysis of the regulation of heterocyst formation and function for subsequent photo-biohydrogen production.« less

Preschoolers’ Genetic, Physiological, and Behavioral Sensitivity Factors Moderate Links Between Parenting Stress and Child Internalizing, Externalizing, and Sleep Problems

PubMed Central

Davis, Molly; Thomassin, Kristel; Bilms, Joanie; Suveg, Cynthia; Shaffer, Anne; Beach, Steven R. H.

2017-01-01

This study examined three potential moderators of the relations between maternal parenting stress and preschoolers’ adjustment problems: a genetic polymorphism - the short allele of the serotonin transporter (5-HTTLPR, ss/sl allele) gene, a physiological indicator - children’s baseline respiratory sinus arrhythmia (RSA), and a behavioral indicator - mothers’ reports of children’s negative emotionality. A total of 108 mothers (Mage = 30.68 years, SDage = 6.06) reported on their parenting stress as well as their preschoolers’ (Mage = 3.50 years, SDage = .51, 61% boys) negative emotionality and internalizing, externalizing, and sleep problems. Results indicated that the genetic sensitivity variable functioned according to a differential susceptibility model; however, the results involving physiological and behavioral sensitivity factors were most consistent with a diathesis-stress framework. Implications for prevention and intervention efforts to counter the effects of parenting stress are discussed. PMID:28295263

Functional Integrative Levels in the Human Interactome Recapitulate Organ Organization

PubMed Central

Prieto, Carlos; Benkahla, Alia; De Las Rivas, Javier; Brun, Christine

2011-01-01

Interactome networks represent sets of possible physical interactions between proteins. They lack spatio-temporal information by construction. However, the specialized functions of the differentiated cell types which are assembled into tissues or organs depend on the combinatorial arrangements of proteins and their physical interactions. Is tissue-specificity, therefore, encoded within the interactome? In order to address this question, we combined protein-protein interactions, expression data, functional annotations and interactome topology. We first identified a subnetwork formed exclusively of proteins whose interactions were observed in all tested tissues. These are mainly involved in housekeeping functions and are located at the topological center of the interactome. This ‘Largest Common Interactome Network’ represents a ‘functional interactome core’. Interestingly, two types of tissue-specific interactions are distinguished when considering function and network topology: tissue-specific interactions involved in regulatory and developmental functions are central whereas tissue-specific interactions involved in organ physiological functions are peripheral. Overall, the functional organization of the human interactome reflects several integrative levels of functions with housekeeping and regulatory tissue-specific functions at the center and physiological tissue-specific functions at the periphery. This gradient of functions recapitulates the organization of organs, from cells to organs. Given that several gradients have already been identified across interactomes, we propose that gradients may represent a general principle of protein-protein interaction network organization. PMID:21799769

Molecular and physiological manifestations and measurement of aging in humans.

PubMed

Khan, Sadiya S; Singer, Benjamin D; Vaughan, Douglas E

2017-08-01

Biological aging is associated with a reduction in the reparative and regenerative potential in tissues and organs. This reduction manifests as a decreased physiological reserve in response to stress (termed homeostenosis) and a time-dependent failure of complex molecular mechanisms that cumulatively create disorder. Aging inevitably occurs with time in all organisms and emerges on a molecular, cellular, organ, and organismal level with genetic, epigenetic, and environmental modulators. Individuals with the same chronological age exhibit differential trajectories of age-related decline, and it follows that we should assess biological age distinctly from chronological age. In this review, we outline mechanisms of aging with attention to well-described molecular and cellular hallmarks and discuss physiological changes of aging at the organ-system level. We suggest methods to measure aging with attention to both molecular biology (e.g., telomere length and epigenetic marks) and physiological function (e.g., lung function and echocardiographic measurements). Finally, we propose a framework to integrate these molecular and physiological data into a composite score that measures biological aging in humans. Understanding the molecular and physiological phenomena that drive the complex and multifactorial processes underlying the variable pace of biological aging in humans will inform how researchers assess and investigate health and disease over the life course. This composite biological age score could be of use to researchers seeking to characterize normal, accelerated, and exceptionally successful aging as well as to assess the effect of interventions aimed at modulating human aging. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Diggin’ on U(biquitin): A Novel Method for the Identification of Physiological E3 Ubiquitin Ligase Substrates

PubMed Central

Rubel, Carrie E.; Schisler, Jonathan C.; Hamlett, Eric D.; DeKroon, Robert M.; Gautel, Mathias; Alzate, Oscar; Patterson, Cam

2013-01-01

The ubiquitin-proteasome system (UPS) plays a central role in maintaining protein homeostasis, emphasized by a myriad of diseases that are associated with altered UPS function such as cancer, muscle-wasting, and neurodegeneration. Protein ubiquitination plays a central role in both the promotion of proteasomal degradation as well as cellular signaling through regulation of the stability of transcription factors and other signaling molecules. Substrate specificity is a critical regulatory step of ubiquitination and is mediated by ubiquitin ligases. Recent studies implicate ubiquitin ligases in multiple models of cardiac diseases such as cardiac hypertrophy, atrophy, and ischemia/reperfusion injury, both in a cardioprotective and maladaptive role. Therefore, identifying physiological substrates of cardiac ubiquitin ligases provides both mechanistic insights into heart disease as well as possible therapeutic targets. Current methods identifying substrates for ubiquitin ligases rely heavily upon non-physiologic in vitro methods, impeding the unbiased discovery of physiological substrates in relevant model systems. Here we describe a novel method for identifying ubiquitin ligase substrates utilizing Tandem Ubiquitin Binding Entities (TUBE) technology, two-dimensional differential in gel electrophoresis (2-D DIGE), and mass spectrometry, validated by the identification of both known and novel physiological substrates of the ubiquitin ligase MuRF1 in primary cardiomyocytes. This method can be applied to any ubiquitin ligase, both in normal and disease model systems, in order to identify relevant physiological substrates under various biological conditions, opening the door to a clearer mechanistic understanding of ubiquitin ligase function and broadening their potential as therapeutic targets. PMID:23695782

Bioreactor-induced mesenchymal progenitor cell differentiation and elastic fiber assembly in engineered vascular tissues.

PubMed

Lin, Shigang; Mequanint, Kibret

2017-09-01

In vitro maturation of engineered vascular tissues (EVT) requires the appropriate incorporation of smooth muscle cells (SMC) and extracellular matrix (ECM) components similar to native arteries. To this end, the aim of the current study was to fabricate 4mm inner diameter vascular tissues using mesenchymal progenitor cells seeded into tubular scaffolds. A dual-pump bioreactor operating either in perfusion or pulsatile perfusion mode was used to generate physiological-like stimuli to promote progenitor cell differentiation, extracellular elastin production, and tissue maturation. Our data demonstrated that pulsatile forces and perfusion of 3D tubular constructs from both the lumenal and ablumenal sides with culture media significantly improved tissue assembly, effectively inducing mesenchymal progenitor cell differentiation to SMCs with contemporaneous elastin production. With bioreactor cultivation, progenitor cells differentiated toward smooth muscle lineage characterized by the expression of smooth muscle (SM)-specific markers smooth muscle alpha actin (SM-α-actin) and smooth muscle myosin heavy chain (SM-MHC). More importantly, pulsatile perfusion bioreactor cultivation enhanced the synthesis of tropoelastin and its extracellular cross-linking into elastic fiber compared with static culture controls. Taken together, the current study demonstrated progenitor cell differentiation and vascular tissue assembly, and provides insights into elastin synthesis and assembly to fibers. Incorporation of elastin into engineered vascular tissues represents a critical design goal for both mechanical and biological functions. In the present study, we seeded porous tubular scaffolds with multipotent mesenchymal progenitor cells and cultured in dual-pump pulsatile perfusion bioreactor. Physiological-like stimuli generated by bioreactor not only induced mesenchymal progenitor cell differentiation to vascular smooth muscle lineage but also actively promoted elastin synthesis and fiber assembly. Gene expression and protein synthesis analyses coupled with histological and immunofluorescence staining revealed that elastin-containing vascular tissues were fabricated. More importantly, co-localization and co-immunoprecipitation experiments demonstrated that elastin and fibrillin-1 were abundant throughout the cross-section of the tissue constructs suggesting a process of elastin protein crosslinking. This study paves a way forward to engineer elastin-containing functional vascular substitutes from multipotent progenitor cells in a bioreactor. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Manganese-Induced Neurotoxicity and Alterations in Gene Expression in Human Neuroblastoma SH-SY5Y Cells.

PubMed

Gandhi, Deepa; Sivanesan, Saravanadevi; Kannan, Krishnamurthi

2018-06-01

Manganese (Mn) is an essential trace element required for many physiological functions including proper biochemical and cellular functioning of the central nervous system (CNS). However, exposure to excess level of Mn through occupational settings or from environmental sources has been associated with neurotoxicity. The cellular and molecular mechanism of Mn-induced neurotoxicity remains unclear. In the current study, we investigated the effects of 30-day exposure to a sub-lethal concentration of Mn (100 μM) in human neuroblastoma cells (SH-SY5Y) using transcriptomic approach. Microarray analysis revealed differential expression of 1057 transcripts in Mn-exposed SH-SY5Y cells as compared to control cells. Gene functional annotation cluster analysis exhibited that the differentially expressed genes were associated with several biological pathways. Specifically, genes involved in neuronal pathways including neuron differentiation and development, regulation of neurogenesis, synaptic transmission, and neuronal cell death (apoptosis) were found to be significantly altered. KEGG pathway analysis showed upregulation of p53 signaling pathways and neuroactive ligand-receptor interaction pathways, and downregulation of neurotrophin signaling pathway. On the basis of the gene expression profile, possible molecular mechanisms underlying Mn-induced neuronal toxicity were predicted.

Pharmacological activation of lysophosphatidic acid receptors regulates erythropoiesis

PubMed Central

Lin, Kuan-Hung; Ho, Ya-Hsuan; Chiang, Jui-Chung; Li, Meng-Wei; Lin, Shi-Hung; Chen, Wei-Min; Chiang, Chi-Ling; Lin, Yu-Nung; Yang, Ya-Jan; Chen, Chiung-Nien; Lu, Jenher; Huang, Chang-Jen; Tigyi, Gabor; Yao, Chao-Ling; Lee, Hsinyu

2016-01-01

Lysophosphatidic acid (LPA), a growth factor-like phospholipid, regulates numerous physiological functions, including cell proliferation and differentiation. In a previous study, we have demonstrated that LPA activates erythropoiesis by activating the LPA 3 receptor subtype (LPA3) under erythropoietin (EPO) induction. In the present study, we applied a pharmacological approach to further elucidate the functions of LPA receptors during red blood cell (RBC) differentiation. In K562 human erythroleukemia cells, knockdown of LPA2 enhanced erythropoiesis, whereas knockdown of LPA3 inhibited RBC differentiation. In CD34+ human hematopoietic stem cells (hHSC) and K526 cells, the LPA3 agonist 1-oleoyl-2-methyl-sn-glycero-3-phosphothionate (2S-OMPT) promoted erythropoiesis, whereas the LPA2 agonist dodecyl monophosphate (DMP) and the nonlipid specific agonist GRI977143 (GRI) suppressed this process. In zebrafish embryos, hemoglobin expression was significantly increased by 2S-OMPT treatment but was inhibited by GRI. Furthermore, GRI treatment decreased, whereas 2S-OMPT treatment increased RBC counts and amount of hemoglobin level in adult BALB/c mice. These results indicate that LPA2 and LPA3 play opposing roles during RBC differentiation. The pharmacological activation of LPA receptor subtypes represent a novel strategies for augmenting or inhibiting erythropoiesis. PMID:27244685

Pharmacological activation of lysophosphatidic acid receptors regulates erythropoiesis.

PubMed

Lin, Kuan-Hung; Ho, Ya-Hsuan; Chiang, Jui-Chung; Li, Meng-Wei; Lin, Shi-Hung; Chen, Wei-Min; Chiang, Chi-Ling; Lin, Yu-Nung; Yang, Ya-Jan; Chen, Chiung-Nien; Lu, Jenher; Huang, Chang-Jen; Tigyi, Gabor; Yao, Chao-Ling; Lee, Hsinyu

2016-05-31

Lysophosphatidic acid (LPA), a growth factor-like phospholipid, regulates numerous physiological functions, including cell proliferation and differentiation. In a previous study, we have demonstrated that LPA activates erythropoiesis by activating the LPA 3 receptor subtype (LPA3) under erythropoietin (EPO) induction. In the present study, we applied a pharmacological approach to further elucidate the functions of LPA receptors during red blood cell (RBC) differentiation. In K562 human erythroleukemia cells, knockdown of LPA2 enhanced erythropoiesis, whereas knockdown of LPA3 inhibited RBC differentiation. In CD34(+) human hematopoietic stem cells (hHSC) and K526 cells, the LPA3 agonist 1-oleoyl-2-methyl-sn-glycero-3-phosphothionate (2S-OMPT) promoted erythropoiesis, whereas the LPA2 agonist dodecyl monophosphate (DMP) and the nonlipid specific agonist GRI977143 (GRI) suppressed this process. In zebrafish embryos, hemoglobin expression was significantly increased by 2S-OMPT treatment but was inhibited by GRI. Furthermore, GRI treatment decreased, whereas 2S-OMPT treatment increased RBC counts and amount of hemoglobin level in adult BALB/c mice. These results indicate that LPA2 and LPA3 play opposing roles during RBC differentiation. The pharmacological activation of LPA receptor subtypes represent a novel strategies for augmenting or inhibiting erythropoiesis.

Cell migration under ultrasound irradiations in micrometer scale

NASA Astrophysics Data System (ADS)

Murakami, Shinya; Otsuka, Yo; Oshima, Yusuke; Hikita, Atsuhiko; Mitsui, Toshiyuki

2013-03-01

Cell movements, migration play an important role in many physiological processes including cell proliferation and differentiation. C2C12, a line of mouse myoblasts is known to differentiate into osteoblast under appropriate conditions. Therefore, C2C12 cells can be chosen for the differentiation studies. However, the movement of the C2C12's has not been fully investigated although the movements may provide a better understanding of the healing processes of bone repair, regeneration and differentiation. In addition, low intensity ultrasound has been thought and used to promote bone fracture healing although the microscopic mechanism of this healing is not well understood. As a first step, we have investigated single cell migration of C2C12 under optical microscopy with and without ultrasound irradiations. The ultrasound is irradiated from an apex of a sharp needle. The frequency is 1.5 MHz and the power intensity is near 24 mW/cm2. These values were similar to the ultrasound treatment values. In this conference, we will show the influence of the ultrasound irradiation on the cell movement by plotting the mean squared displacement and the velocity autocorrelation function as a function of time.

MAPK pathway control of stem cell proliferation and differentiation in the embryonic pituitary provides insights into the pathogenesis of papillary craniopharyngioma

PubMed Central

Pozzi, Sara; Carreno, Gabriela; Manshaei, Saba; Panousopoulos, Leonidas; Gonzalez-Meljem, Jose Mario; Apps, John R.; Virasami, Alex; Thavaraj, Selvam; Gutteridge, Alice; Forshew, Tim; Marais, Richard; Brandner, Sebastian; Jacques, Thomas S.; Andoniadou, Cynthia L.

2017-01-01

Despite the importance of the RAS-RAF-MAPK pathway in normal physiology and disease of numerous organs, its role during pituitary development and tumourigenesis remains largely unknown. Here, we show that the over-activation of the MAPK pathway, through conditional expression of the gain-of-function alleles BrafV600E and KrasG12D in the developing mouse pituitary, results in severe hyperplasia and abnormal morphogenesis of the gland by the end of gestation. Cell-lineage commitment and terminal differentiation are disrupted, leading to a significant reduction in numbers of most of the hormone-producing cells before birth, with the exception of corticotrophs. Of note, Sox2+ stem cells and clonogenic potential are drastically increased in the mutant pituitaries. Finally, we reveal that papillary craniopharyngioma (PCP), a benign human pituitary tumour harbouring BRAF p.V600E also contains Sox2+ cells with sustained proliferative capacity and disrupted pituitary differentiation. Together, our data demonstrate a crucial function of the MAPK pathway in controlling the balance between proliferation and differentiation of Sox2+ cells and suggest that persistent proliferative capacity of Sox2+ cells may underlie the pathogenesis of PCP. PMID:28506993

Large, stratified, and mechanically functional human cartilage grown in vitro by mesenchymal condensation

PubMed Central

Bhumiratana, Sarindr; Eton, Ryan E.; Oungoulian, Sevan R.; Wan, Leo Q.; Ateshian, Gerard A.; Vunjak-Novakovic, Gordana

2014-01-01

The efforts to grow mechanically functional cartilage from human mesenchymal stem cells have not been successful. We report that clinically sized pieces of human cartilage with physiologic stratification and biomechanics can be grown in vitro by recapitulating some aspects of the developmental process of mesenchymal condensation. By exposure to transforming growth factor-β, mesenchymal stem cells were induced to condense into cellular bodies, undergo chondrogenic differentiation, and form cartilagenous tissue, in a process designed to mimic mesenchymal condensation leading into chondrogenesis. We discovered that the condensed mesenchymal cell bodies (CMBs) formed in vitro set an outer boundary after 5 d of culture, as indicated by the expression of mesenchymal condensation genes and deposition of tenascin. Before setting of boundaries, the CMBs could be fused into homogenous cellular aggregates giving rise to well-differentiated and mechanically functional cartilage. We used the mesenchymal condensation and fusion of CMBs to grow centimeter-sized, anatomically shaped pieces of human articular cartilage over 5 wk of culture. For the first time to our knowledge biomechanical properties of cartilage derived from human mesenchymal cells were comparable to native cartilage, with the Young’s modulus of >800 kPa and equilibrium friction coeffcient of <0.3. We also demonstrate that CMBs have capability to form mechanically strong cartilage–cartilage interface in an in vitro cartilage defect model. The CMBs, which acted as “lego-like” blocks of neocartilage, were capable of assembling into human cartilage with physiologic-like structure and mechanical properties. PMID:24778247

Microtubule-regulating proteins and cAMP-dependent signaling in neuroblastoma differentiation.

PubMed

Muñoz-Llancao, Pablo; de Gregorio, Cristian; Las Heras, Macarena; Meinohl, Christopher; Noorman, Kevin; Boddeke, Erik; Cheng, Xiaodong; Lezoualc'h, Frank; Schmidt, Martina; Gonzalez-Billault, Christian

2017-03-01

Neurons are highly differentiated cells responsible for the conduction and transmission of information in the nervous system. The proper function of a neuron relies on the compartmentalization of their intracellular domains. Differentiated neuroblastoma cells have been extensively used to study and understand the physiology and cell biology of neuronal cells. Here, we show that differentiation of N1E-115 neuroblastoma cells is more pronounced upon exposure of a chemical analog of cyclic AMP (cAMP), db-cAMP. We next analysed the expression of key microtubule-regulating proteins in differentiated cells and the expression and activation of key cAMP players such as EPAC, PKA and AKAP79/150. Most of the microtubule-promoting factors were up regulated during differentiation of N1E-115 cells, while microtubule-destabilizing proteins were down regulated. We observed an increase in tubulin post-translational modifications related to microtubule stability. As expected, db-cAMP increased PKA- and EPAC-dependent signalling. Consistently, pharmacological modulation of EPAC activity instructed cell differentiation, number of neurites, and neurite length in N1E-115 cells. Moreover, disruption of the PKA-AKAP interaction reduced these morphometric parameters. Interestingly, PKA and EPAC act synergistically to induce neuronal differentiation in N1E-115. Altogether these results show that the changes observed in the differentiation of N1E-115 cells proceed by regulating several microtubule-stabilizing factors, and the acquisition of a neuronal phenotype is a process involving concerted although independent functions of EPAC and PKA. © 2017 Wiley Periodicals, Inc.

21 CFR 882.1845 - Physiological signal conditioner.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Physiological signal conditioner. 882.1845 Section... signal conditioner. (a) Identification. A physiological signal conditioner is a device such as an integrator or differentiator used to modify physiological signals for recording and processing. (b...

21 CFR 882.1845 - Physiological signal conditioner.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Physiological signal conditioner. 882.1845 Section... signal conditioner. (a) Identification. A physiological signal conditioner is a device such as an integrator or differentiator used to modify physiological signals for recording and processing. (b...

A Cbfa1-dependent genetic pathway controls bone formation beyond embryonic development

PubMed Central

Ducy, Patricia; Starbuck, Michael; Priemel, Matthias; Shen, Jianhe; Pinero, Gerald; Geoffroy, Valerie; Amling, Michael; Karsenty, Gerard

1999-01-01

The molecular mechanisms controlling bone extracellular matrix (ECM) deposition by differentiated osteoblasts in postnatal life, called hereafter bone formation, are unknown. This contrasts with the growing knowledge about the genetic control of osteoblast differentiation during embryonic development. Cbfa1, a transcriptional activator of osteoblast differentiation during embryonic development, is also expressed in differentiated osteoblasts postnatally. The perinatal lethality occurring in Cbfa1-deficient mice has prevented so far the study of its function after birth. To determine if Cbfa1 plays a role during bone formation we generated transgenic mice overexpressing Cbfa1 DNA-binding domain (ΔCbfa1) in differentiated osteoblasts only postnatally. ΔCbfa1 has a higher affinity for DNA than Cbfa1 itself, has no transcriptional activity on its own, and can act in a dominant-negative manner in DNA cotransfection assays. ΔCbfa1-expressing mice have a normal skeleton at birth but develop an osteopenic phenotype thereafter. Dynamic histomorphometric studies show that this phenotype is caused by a major decrease in the bone formation rate in the face of a normal number of osteoblasts thus indicating that once osteoblasts are differentiated Cbfa1 regulates their function. Molecular analyses reveal that the expression of the genes expressed in osteoblasts and encoding bone ECM proteins is nearly abolished in transgenic mice, and ex vivo assays demonstrated that ΔCbfa1-expressing osteoblasts were less active than wild-type osteoblasts. We also show that Cbfa1 regulates positively the activity of its own promoter, which has the highest affinity Cbfa1-binding sites characterized. This study demonstrates that beyond its differentiation function Cbfa1 is the first transcriptional activator of bone formation identified to date and illustrates that developmentally important genes control physiological processes postnatally. PMID:10215629

Myeloblastic leukemia cells conditionally blocked by myc-estrogen receptor chimeric transgenes for terminal differentiation coupled to growth arrest and apoptosis.

PubMed

Selvakumaran, M; Liebermann, D; Hoffman-Liebermann, B

1993-05-01

Conditional mutants of the myeloblastic leukemic M1 cell line, expressing the chimeric mycer transgene, have been established. It is shown that M1 mycer cells, like M1, undergo terminal differentiation coupled to growth arrest and programmed cell death (apoptosis) after treatment with the physiologic differentiation inducer interleukin-6. However, when beta-estradiol is included in the culture medium, M1 mycer cells respond to differentiation inducers like M1 myc cell lines, where the differentiation program is blocked at an intermediate stage. By manipulating the function of the mycer transgene product, it is shown that there is a 10-hour window during myeloid differentiation, from 30 to 40 hours after the addition of the differentiation inducer, when the terminal differentiation program switches from being dependent on c-myc suppression to becoming c-myc suppression independent, where activation of c-myc has no apparent effect on mature macrophages. M1 mycer cell lines provide a powerful tool to increase our understanding of the role of c-myc in normal myelopoiesis and in leukemogenesis, also providing a strategy to clone c-myc target genes.

Physiological and pathophysiological functions of SIRT1.

PubMed

Wojcik, M; Mac-Marcjanek, K; Wozniak, L A

2009-03-01

The human SIRT1 is a nuclear enzyme from the class III histone deacetylases (HDACs) which is widely distributed in mammalian tissues. A variety of SIRT1 substrates hints that this protein is involved in the regulation of diverse biological processes, including cell survival, apoptosis, gluconeogenesis, adipogenesis, lipolysis, stress resistance, muscle differentiation, and insulin secretion. This review emphasizes catalytic properties of SIRT1 and its role in apoptosis, insulin pathway, and neuron survival.

Molecular Cloning of Human Gene(s) Directing the Synthesis of Nervous System Cholinesterases

DTIC Science & Technology

1987-09-01

and shed light on the unknown physiological function of these serine hydrolases in proliferating and differentiating cells. In pheochromocytoma cells...Reiness, C.G., Reichardt, L.F. and Hall, Z.W. (1981) Cellular localization of the molecular forms of acetylcholinesterase in rat pheochromocytoma PC12...melanogaster: Structural gene for acetylcholinesterase with an unusual 5’ leader. The EMBO J., 2949-2954. 99. Merken, L., Simons, M.J., Swillens, S

Population genomics of the killer whale indicates ecotype evolution in sympatry involving both selection and drift.

PubMed

Moura, Andre E; Kenny, John G; Chaudhuri, Roy; Hughes, Margaret A; J Welch, Andreanna; Reisinger, Ryan R; de Bruyn, P J Nico; Dahlheim, Marilyn E; Hall, Neil; Hoelzel, A Rus

2014-11-01

The evolution of diversity in the marine ecosystem is poorly understood, given the relatively high potential for connectivity, especially for highly mobile species such as whales and dolphins. The killer whale (Orcinus orca) has a worldwide distribution, and individual social groups travel over a wide geographic range. Even so, regional populations have been shown to be genetically differentiated, including among different foraging specialists (ecotypes) in sympatry. Given the strong matrifocal social structure of this species together with strong resource specializations, understanding the process of differentiation will require an understanding of the relative importance of both genetic drift and local adaptation. Here we provide a high-resolution analysis based on nuclear single-nucleotide polymorphic markers and inference about differentiation at both neutral loci and those potentially under selection. We find that all population comparisons, within or among foraging ecotypes, show significant differentiation, including populations in parapatry and sympatry. Loci putatively under selection show a different pattern of structure compared to neutral loci and are associated with gene ontology terms reflecting physiologically relevant functions (e.g. related to digestion). The pattern of differentiation for one ecotype in the North Pacific suggests local adaptation and shows some fixed differences among sympatric ecotypes. We suggest that differential habitat use and resource specializations have promoted sufficient isolation to allow differential evolution at neutral and functional loci, but that the process is recent and dependent on both selection and drift. © 2014 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.

Population genomics of the killer whale indicates ecotype evolution in sympatry involving both selection and drift

PubMed Central

Moura, Andre E; Kenny, John G; Chaudhuri, Roy; Hughes, Margaret A; J Welch, Andreanna; Reisinger, Ryan R; de Bruyn, P J Nico; Dahlheim, Marilyn E; Hall, Neil; Hoelzel, A Rus

2014-01-01

The evolution of diversity in the marine ecosystem is poorly understood, given the relatively high potential for connectivity, especially for highly mobile species such as whales and dolphins. The killer whale (Orcinus orca) has a worldwide distribution, and individual social groups travel over a wide geographic range. Even so, regional populations have been shown to be genetically differentiated, including among different foraging specialists (ecotypes) in sympatry. Given the strong matrifocal social structure of this species together with strong resource specializations, understanding the process of differentiation will require an understanding of the relative importance of both genetic drift and local adaptation. Here we provide a high-resolution analysis based on nuclear single-nucleotide polymorphic markers and inference about differentiation at both neutral loci and those potentially under selection. We find that all population comparisons, within or among foraging ecotypes, show significant differentiation, including populations in parapatry and sympatry. Loci putatively under selection show a different pattern of structure compared to neutral loci and are associated with gene ontology terms reflecting physiologically relevant functions (e.g. related to digestion). The pattern of differentiation for one ecotype in the North Pacific suggests local adaptation and shows some fixed differences among sympatric ecotypes. We suggest that differential habitat use and resource specializations have promoted sufficient isolation to allow differential evolution at neutral and functional loci, but that the process is recent and dependent on both selection and drift. PMID:25244680

PA6 Stromal Cell Co-Culture Enhances SH-SY5Y and VSC4.1 Neuroblastoma Differentiation to Mature Phenotypes

PubMed Central

Ferguson, Ross; Subramanian, Vasanta

2016-01-01

Neuroblastoma cell lines such as SH-SY5Y have been used for modelling neurodegenerative diseases and for studying basic mechanisms in neuroscience. Since neuroblastoma cells proliferate and generally do not express markers of mature or functional neurons, we exploited a co-culture system with the stromal cell line PA6 to better induce differentiation to a more physiologically relevant status. We found that co-culture of the neuroblastoma cell lines in the presence of neural inducers such retinoic acid was able to generate a high proportion of quiescent neurons with very long neurites expressing differentiation markers. The co-culture system additionally cuts short the time taken to produce a more mature phenotype. We also show the application of this system to study proteins implicated in motor neuron disease. PMID:27391595

PA6 Stromal Cell Co-Culture Enhances SH-SY5Y and VSC4.1 Neuroblastoma Differentiation to Mature Phenotypes.

PubMed

Ferguson, Ross; Subramanian, Vasanta

2016-01-01

Neuroblastoma cell lines such as SH-SY5Y have been used for modelling neurodegenerative diseases and for studying basic mechanisms in neuroscience. Since neuroblastoma cells proliferate and generally do not express markers of mature or functional neurons, we exploited a co-culture system with the stromal cell line PA6 to better induce differentiation to a more physiologically relevant status. We found that co-culture of the neuroblastoma cell lines in the presence of neural inducers such retinoic acid was able to generate a high proportion of quiescent neurons with very long neurites expressing differentiation markers. The co-culture system additionally cuts short the time taken to produce a more mature phenotype. We also show the application of this system to study proteins implicated in motor neuron disease.

[P21-activated kinases and their role in the nervous system].

PubMed

Qin, Yuan; Ding, Yue-Min; Xia, Qiang

2012-12-25

P21-activated kinases (PAK) participate in a variety of important cellular activities, such as cytoskeleton remodeling, cell migration, cell cycle regulation, and apoptosis or survival. PAK also has an important impact on brain development, neuronal differentiation, and regulation of synaptic plasticity in the nervous system. PAK abnormalities result in diseases including cancer, Parkinson's disease (PD), Alzheimer's disease (AD) and neural retardation. Therefore, it is of vital physiological significance to investigate the neuronal function of PAK. In this paper we review the advancement of research on the neuronal biological function and the underlying mechanisms of PAK.

Biochemical and physiological processes associated with the differential ozone response in ozone-tolerant and sensitive soybean genotypes

USDA-ARS?s Scientific Manuscript database

Biochemical and physiological traits of two soybean [Glycine max (L.) Merr.] genotypes that differ in sensitivity to ozone (O3) were investigated to determine the possible basis for the differential response. Fiskeby III (O3-tolerant) and Mandarin (Ottawa) (O3-sensitive) were grown in a greenhouse ...

Identification of genes differentially expressed during adventitious shoot induction in Pinus pinea cotyledons by subtractive hybridization and quantitative PCR.

PubMed

Alonso, Pablo; Cortizo, Millán; Cantón, Francisco R; Fernández, Belén; Rodríguez, Ana; Centeno, Maria L; Cánovas, Francisco M; Ordás, Ricardo J

2007-12-01

As part of a study aimed at understanding the physiological and molecular mechanisms involved in adventitious shoot bud formation in pine cotyledons, we conducted a transcriptome analysis to identify early-induced genes during the first phases of adventitious caulogenesis in Pinus pinea L. cotyledons cultured in the presence of benzyladenine. A subtractive cDNA library with more than 700 clones was constructed. Of these clones, 393 were sequenced, analyzed and grouped according to their putative function. Quantitative real-time PCR analysis was performed to confirm the differential expression of 30 candidate genes. Results are contrasted with available data for other species.

A new approach for designing self-organizing systems and application to adaptive control

NASA Technical Reports Server (NTRS)

Ramamoorthy, P. A.; Zhang, Shi; Lin, Yueqing; Huang, Song

1993-01-01

There is tremendous interest in the design of intelligent machines capable of autonomous learning and skillful performance under complex environments. A major task in designing such systems is to make the system plastic and adaptive when presented with new and useful information and stable in response to irrelevant events. A great body of knowledge, based on neuro-physiological concepts, has evolved as a possible solution to this problem. Adaptive resonance theory (ART) is a classical example under this category. The system dynamics of an ART network is described by a set of differential equations with nonlinear functions. An approach for designing self-organizing networks characterized by nonlinear differential equations is proposed.

Distinct roles for Ste20-like kinase SLK in muscle function and regeneration

PubMed Central

2013-01-01

Background Cell growth and terminal differentiation are controlled by complex signaling systems that regulate the tissue-specific expression of genes controlling cell fate and morphogenesis. We have previously reported that the Ste20-like kinase SLK is expressed in muscle tissue and is required for cell motility. However, the specific function of SLK in muscle tissue is still poorly understood. Methods To gain further insights into the role of SLK in differentiated muscles, we expressed a kinase-inactive SLK from the human skeletal muscle actin promoter. Transgenic muscles were surveyed for potential defects. Standard histological procedures and cardiotoxin-induced regeneration assays we used to investigate the role of SLK in myogenesis and muscle repair. Results High levels of kinase-inactive SLK in muscle tissue produced an overall decrease in SLK activity in muscle tissue, resulting in altered muscle organization, reduced litter sizes, and reduced breeding capacity. The transgenic mice did not show any differences in fiber-type distribution but displayed enhanced regeneration capacity in vivo and more robust differentiation in vitro. Conclusions Our results show that SLK activity is required for optimal muscle development in the embryo and muscle physiology in the adult. However, reduced kinase activity during muscle repair enhances regeneration and differentiation. Together, these results suggest complex and distinct roles for SLK in muscle development and function. PMID:23815977

Generation of a transplantable erythropoietin-producer derived from human mesenchymal stem cells.

PubMed

Yokoo, Takashi; Fukui, Akira; Matsumoto, Kei; Ohashi, Toya; Sado, Yoshikazu; Suzuki, Hideaki; Kawamura, Tetsuya; Okabe, Masataka; Hosoya, Tatsuo; Kobayashi, Eiji

2008-06-15

Differentiation of autologous stem cells into functional transplantable tissue for organ regeneration is a promising regenerative therapeutic approach for cancer, diabetes, and many human diseases. Yet to be established, however, is differentiation into tissue capable of producing erythropoietin (EPO), which has a critical function in anemia. We report a novel EPO-producing organ-like structure (organoid) derived from human mesenchymal stem cells. Using our previously established relay culture system, a human mesenchymal stem cell-derived, human EPO-competent organoid was established in rat omentum. The organoid-derived levels of human EPO increased in response to anemia induced by rapid blood withdrawal. In addition, the presence of an organoid in rats suppressed for native (rat) EPO production enhanced recovery from anemia when compared with control animals lacking the organoid. Together these results confirmed the generation of a stem cell-derived organoid that is capable of producing EPO and sensitive to physiological regulation.

Regulatory Peptides in Plants.

PubMed

Vanyushin, B F; Ashapkin, V V; Aleksandrushkina, N I

2017-02-01

Many different peptides regulating cell differentiation, growth, and development are found in plants. Peptides participate in regulation of plant ontogenesis starting from pollination, pollen tube growth, and the very early stages of embryogenesis, including formation of embryo and endosperm. They direct differentiation of meristematic stem cells, formation of tissues and individual organs, take part in regulation of aging, fruit maturation, and abscission of plant parts associated with apoptosis. Biological activity of peptides is observed at very low concentrations, and it has mainly signal nature and hormonal character. "Mature" peptides appear mainly due to processing of protein precursors with (or without) additional enzymatic modifications. Plant peptides differ in origin, structure, and functional properties. Their specific action is due to binding with respective receptors and interactions with various proteins and other factors. Peptides can also regulate physiological functions by direct peptide-protein interactions. Peptide action is coordinated with the action of known phytohormones (auxins, cytokinins, and others); thus, peptides control phytohormonal signal pathways.

Circ-ZNF609 Is a Circular RNA that Can Be Translated and Functions in Myogenesis.

PubMed

Legnini, Ivano; Di Timoteo, Gaia; Rossi, Francesca; Morlando, Mariangela; Briganti, Francesca; Sthandier, Olga; Fatica, Alessandro; Santini, Tiziana; Andronache, Adrian; Wade, Mark; Laneve, Pietro; Rajewsky, Nikolaus; Bozzoni, Irene

2017-04-06

Circular RNAs (circRNAs) constitute a family of transcripts with unique structures and still largely unknown functions. Their biogenesis, which proceeds via a back-splicing reaction, is fairly well characterized, whereas their role in the modulation of physiologically relevant processes is still unclear. Here we performed expression profiling of circRNAs during in vitro differentiation of murine and human myoblasts, and we identified conserved species regulated in myogenesis and altered in Duchenne muscular dystrophy. A high-content functional genomic screen allowed the study of their functional role in muscle differentiation. One of them, circ-ZNF609, resulted in specifically controlling myoblast proliferation. Circ-ZNF609 contains an open reading frame spanning from the start codon, in common with the linear transcript, and terminating at an in-frame STOP codon, created upon circularization. Circ-ZNF609 is associated with heavy polysomes, and it is translated into a protein in a splicing-dependent and cap-independent manner, providing an example of a protein-coding circRNA in eukaryotes. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Potential role of retinoids in ovarian physiology and pathogenesis of polycystic ovary syndrome.

PubMed

Jiang, Yanwen; Li, Chunjin; Chen, Lu; Wang, Fengge; Zhou, Xu

2017-06-01

Retinoids (retinol and its derivatives) are required for maintaining vision, immunity, barrier function, reproduction, embryogenesis, cell proliferation and differentiation. Furthermore, retinoid signaling plays a key role in initiating meiosis of germ cells of the mammalian fetal ovary. Recently, studies indicated that precise retinoid level regulation in the ovary provides a molecular control of ovarian development, steroidogenesis and oocyte maturation. Besides, abnormal retinoid signaling may be involved in the pathogenesis of polycystic ovary syndrome (PCOS), one of the most common ovarian endocrinopathies in reproductive-aged women worldwide. This review primarily summarizes recent advancements made in investigating the action of retinoid signaling in ovarian physiology as well as the abnormal retinoid signaling in PCOS. Copyright © 2017. Published by Elsevier B.V.

Differential physiological changes following internet exposure in higher and lower problematic internet users

PubMed Central

Romano, Michela; Re, Federica; Roaro, Alessandra; Osborne, Lisa A.; Viganò, Caterina; Truzoli, Roberto

2017-01-01

Problematic internet use (PIU) has been suggested as in need of further research with a view to being included as a disorder in future Diagnostic and Statistical Manual (DSM) of the American Psychiatric Association, but lack of knowledge about the impact of internet cessation on physiological function remains a major gap in knowledge and a barrier to PIU classification. One hundred and forty-four participants were assessed for physiological (blood pressure and heart rate) and psychological (mood and state anxiety) function before and after an internet session. Individuals also completed a psychometric examination relating to their usage of the internet, as well as their levels of depression and trait anxiety. Individuals who identified themselves as having PIU displayed increases in heart rate and systolic blood pressure, as well as reduced mood and increased state of anxiety, following cessation of internet session. There were no such changes in individuals with no self-reported PIU. These changes were independent of levels of depression and trait anxiety. These changes after cessation of internet use are similar to those seen in individuals who have ceased using sedative or opiate drugs, and suggest PIU deserves further investigation and serious consideration as a disorder. PMID:28542470

Tooth wear: the view of the anthropologist

PubMed Central

2007-01-01

Anthropologists have for many years considered human tooth wear a normal physiological phenomenon where teeth, although worn, remain functional throughout life. Wear was considered pathological only if pulpal exposure or premature tooth loss occurred. In addition, adaptive changes to the stomatognathic system in response to wear have been reported including continual eruption, the widening of the masticatory cycle, remodelling of the temporomandibular joint and the shortening of the dental arches from tooth migration. Comparative studies of many different species have also documented these physiological processes supporting the idea of perpetual change over time. In particular, differential wear between enamel and dentine was considered a physiological process relating to the evolution of the form and function of teeth. Although evidence of attrition and abrasion has been known to exist among hunter-gatherer populations for many thousands of years, the prevalence of erosion in such early populations seems insignificant. In particular, non-carious cervical lesions to date have not been observed within these populations and therefore should be viewed as ‘modern-day’ pathology. Extrapolating this anthropological perspective to the clinical setting has merits, particularly in the prevention of pre-mature unnecessary treatment. PMID:17938977

Transcriptomic response of the Antarctic pteropod Limacina helicina antarctica to ocean acidification.

PubMed

Johnson, Kevin M; Hofmann, Gretchen E

2017-10-23

Ocean acidification (OA), a change in ocean chemistry due to the absorption of atmospheric CO 2 into surface oceans, challenges biogenic calcification in many marine organisms. Ocean acidification is expected to rapidly progress in polar seas, with regions of the Southern Ocean expected to experience severe OA within decades. Biologically, the consequences of OA challenge calcification processes and impose an energetic cost. In order to better characterize the response of a polar calcifier to conditions of OA, we assessed differential gene expression in the Antarctic pteropod, Limacina helicina antarctica. Experimental levels of pCO 2 were chosen to create both contemporary pH conditions, and to mimic future pH expected in OA scenarios. Significant changes in the transcriptome were observed when juvenile L. h. antarctica were acclimated for 21 days to low-pH (7.71), mid-pH (7.9) or high-pH (8.13) conditions. Differential gene expression analysis of individuals maintained in the low-pH treatment identified down-regulation of genes involved in cytoskeletal structure, lipid transport, and metabolism. High pH exposure led to increased expression and enrichment for genes involved in shell formation, calcium ion binding, and DNA binding. Significant differential gene expression was observed in four major cellular and physiological processes: shell formation, the cellular stress response, metabolism, and neural function. Across these functional groups, exposure to conditions that mimic ocean acidification led to rapid suppression of gene expression. Results of this study demonstrated that the transcriptome of the juvenile pteropod, L. h. antarctica, was dynamic and changed in response to different levels of pCO 2 . In a global change context, exposure of L. h. antarctica to the low pH, high pCO 2 OA conditions resulted in a suppression of transcripts for genes involved in key physiological processes: calcification, metabolism, and the cellular stress response. The transcriptomic response at both acute and longer-term acclimation time frames indicated that contemporary L. h. antarctica may not have the physiological plasticity necessary for adaptation to OA conditions expected in future decades. Lastly, the differential gene expression results further support the role of shelled pteropods such as L. h. antarctica as sentinel organisms for the impacts of ocean acidification.

Development and Validation of the Homeostasis Concept Inventory

PubMed Central

McFarland, Jenny L.; Price, Rebecca M.; Wenderoth, Mary Pat; Martinková, Patrícia; Cliff, William; Michael, Joel; Modell, Harold; Wright, Ann

2017-01-01

We present the Homeostasis Concept Inventory (HCI), a 20-item multiple-choice instrument that assesses how well undergraduates understand this critical physiological concept. We used an iterative process to develop a set of questions based on elements in the Homeostasis Concept Framework. This process involved faculty experts and undergraduate students from associate’s colleges, primarily undergraduate institutions, regional and research-intensive universities, and professional schools. Statistical results provided strong evidence for the validity and reliability of the HCI. We found that graduate students performed better than undergraduates, biology majors performed better than nonmajors, and students performed better after receiving instruction about homeostasis. We used differential item analysis to assess whether students from different genders, races/ethnicities, and English language status performed differently on individual items of the HCI. We found no evidence of differential item functioning, suggesting that the items do not incorporate cultural or gender biases that would impact students’ performance on the test. Instructors can use the HCI to guide their teaching and student learning of homeostasis, a core concept of physiology. PMID:28572177

Differential roles of breakfast and supper in rats of a daily three-meal schedule upon circadian regulation and physiology.

PubMed

Wu, Tao; Sun, Lu; ZhuGe, Fen; Guo, Xichao; Zhao, Zhining; Tang, Ruiqi; Chen, Qinping; Chen, Lin; Kato, Hisanori; Fu, Zhengwei

2011-12-01

The timing of meals has been suggested to play an important role in circadian regulation and metabolic health. Three meals a day is a well-established human feeding habit, which in today's lifestyle may or may not be followed. The aim of this study was to test whether the absence of breakfast or supper significantly affects the circadian system and physiological function. The authors developed a rat model for their daily three meals study, whereby animals were divided into three groups (three meals, TM; no first meal, NF; no last meal, NL) all fed with the same amount of food every day. Rats in the NF group displayed significantly decreased levels of plasma triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and glucose in the activity phase, accompanied by delayed circadian phases of hepatic peripheral clock and downstream metabolic genes. Rats in the NL group showed lower concentration of plasma TC, HDL-C, and glucose in the rest phase, plus reduced adipose tissue accumulation and body weight gain. Real-time polymerase chain reaction (PCR) analysis indicated an attenuated rhythm in the food-entraining pathway, including down-regulated expression of the clock genes Per2, Bmal1, and Rev-erbα, which may further contribute to the delayed and decreased expression of FAS in lipogenesis in this group. Our findings are consistent with the conclusion that the daily first meal determines the circadian phasing of peripheral clocks, such as in the liver, whereas the daily last meal tightly couples to lipid metabolism and adipose tissue accumulation, which suggests differential physiological effects and function of the respective meal timings.

Subtractive cloning of cDNA from Aspergillus oryzae differentially regulated between solid-state culture and liquid (submerged) culture.

PubMed

Akao, Takeshi; Gomi, Katsuya; Goto, Kuniyasu; Okazaki, Naoto; Akita, Osamu

2002-07-01

In solid-state cultures (SC), Aspergillus oryzae shows characteristics such as high-level production and secretion of enzymes and hyphal differentiation with asexual development which are absent in liquid (submerged) culture (LC). It was predicted that many of the genes involved in the characteristics of A. oryzae in SC are differentially expressed between SC and LC. We generated two subtracted cDNA libraries with bi-directional cDNA subtractive hybridizations to isolate and identify such genes. Among them, we identified genes upregulated in or specific to SC, such as the AOS ( A. oryzae SC-specific gene) series, and those downregulated or not expressed in SC, such as the AOL ( A. oryzae LC-specific) series. Sequencing analyses revealed that the AOS series and the AOL series contain genes encoding extra- and intracellular enzymes and transport proteins. However, half were functionally unclassified by nucleotide sequences. Also, by expression profile, the AOS series comprised two groups. These gene products' molecular functions and physiological roles in SC await further investigation.

MiRNAs with Apoptosis Regulating Potential Are Differentially Expressed in Chronic Exercise-Induced Physiologically Hypertrophied Hearts

PubMed Central

Ramprasath, Tharmarajan; Kalpana, Krishnan

2015-01-01

Physiological cardiac hypertrophy is an adaptive mechanism, induced during chronic exercise. As it is reversible and not associated with cardiomyocyte death, it is considered as a natural tactic to prevent cardiac dysfunction and failure. Though, different studies revealed the importance of microRNAs (miRNAs) in pathological hypertrophy, their role during physiological hypertrophy is largely unexplored. Hence, this study is aimed at revealing the global expression profile of miRNAs during physiological cardiac hypertrophy. Chronic swimming protocol continuously for eight weeks resulted in induction of physiological hypertrophy in rats and histopathology revealed the absence of tissue damage, apoptosis or fibrosis. Subsequently, the total RNA was isolated and small RNA sequencing was executed. Analysis of small RNA reads revealed the differential expression of a large set of miRNAs during physiological hypertrophy. The expression profile of the significantly differentially expressed miRNAs was validated by qPCR. In silico prediction of target genes by miRanda, miRdB and TargetScan and subsequent qPCR analysis unraveled that miRNAs including miR-99b, miR-100, miR-19b, miR-10, miR-208a, miR-133, miR-191a, miR-22, miR-30e and miR-181a are targeting the genes that primarily regulate cell proliferation and cell death. Gene ontology and pathway mapping showed that the differentially expressed miRNAs and their target genes were mapped to apoptosis and cell death pathways principally via PI3K/Akt/mTOR and MAPK signaling. In summary, our data indicates that regulation of these miRNAs with apoptosis regulating potential can be one of the major key factors in determining pathological or physiological hypertrophy by controlling fibrosis, apoptosis and cell death mechanisms. PMID:25793527

Resting-State Functional Connectivity Differentiates Anxious Apprehension and Anxious Arousal

PubMed Central

Burdwood, Erin N.; Infantolino, Zachary P.; Crocker, Laura D.; Spielberg, Jeffrey M.; Banich, Marie T.; Miller, Gregory A.; Heller, Wendy

2016-01-01

Brain regions in the default mode network (DMN) display greater functional connectivity at rest or during self-referential processing than during goal-directed tasks. The present study assessed resting-state connectivity as a function of anxious apprehension and anxious arousal, independent of depressive symptoms, in order to understand how these dimensions disrupt cognition. Whole-brain, seed-based analyses indicated differences between anxious apprehension and anxious arousal in DMN functional connectivity. Lower connectivity associated with higher anxious apprehension suggests decreased adaptive, inner-focused thought processes, whereas higher connectivity at higher levels of anxious arousal may reflect elevated monitoring of physiological responses to threat. These findings further the conceptualization of anxious apprehension and anxious arousal as distinct psychological dimensions with distinct neural instantiations. PMID:27406406

[Definition of surgical degree of freedom by functional anatomy in liver resection surgery].

PubMed

Kraus, T W; Golling, M; Klar, E

2001-07-01

Liver resections have developed to very complex and differentiated operations, clearly adapted to individual anatomical and physiological conditions. In parallel, perioperative morbidity has been dramatically reduced. Intraoperative strict consideration of various details of hepatic anatomy, particularly of functional liver anatomy, has proved to be of particular importance when liver surgery reaches indication and technical limits. The term "functional anatomy" stands for a form of hepatic substructurization, which is primarily based on the existence of hemodynamically independent regions of liver parenchyma. A selection of some of the most important details and facts of functional liver anatomy and secondary derived guidelines for surgical strategy and technique is presented in an overview, with special focus on liver resection.

Mechanisms of physiological and pathological cardiac hypertrophy.

PubMed

Nakamura, Michinari; Sadoshima, Junichi

2018-04-19

Cardiomyocytes exit the cell cycle and become terminally differentiated soon after birth. Therefore, in the adult heart, instead of an increase in cardiomyocyte number, individual cardiomyocytes increase in size, and the heart develops hypertrophy to reduce ventricular wall stress and maintain function and efficiency in response to an increased workload. There are two types of hypertrophy: physiological and pathological. Hypertrophy initially develops as an adaptive response to physiological and pathological stimuli, but pathological hypertrophy generally progresses to heart failure. Each form of hypertrophy is regulated by distinct cellular signalling pathways. In the past decade, a growing number of studies have suggested that previously unrecognized mechanisms, including cellular metabolism, proliferation, non-coding RNAs, immune responses, translational regulation, and epigenetic modifications, positively or negatively regulate cardiac hypertrophy. In this Review, we summarize the underlying molecular mechanisms of physiological and pathological hypertrophy, with a particular emphasis on the role of metabolic remodelling in both forms of cardiac hypertrophy, and we discuss how the current knowledge on cardiac hypertrophy can be applied to develop novel therapeutic strategies to prevent or reverse pathological hypertrophy.

Physiologically mediated self/non-self discrimination in roots

PubMed Central

Gruntman, Michal; Novoplansky, Ariel

2004-01-01

Recent evidence suggests that self/non-self discrimination exists among roots; its mechanisms, however, are still unclear. We compared the growth of Buchloe dactyloides cuttings that were grown in the presence of neighbors that belonged to the same physiological individual, were separated from each other for variable periods, or originated from adjacent or remote tillers on the same clone. The results demonstrate that B. dactyloides plants are able to differentiate between self and non-self neighbors and develop fewer and shorter roots in the presence of other roots of the same individual. Furthermore, once cuttings that originate from the very same node are separated, they become progressively alienated from each other and eventually relate to each other as genetically alien plants. The results suggest that the observed self/non-self discrimination is mediated by physiological coordination among roots that developed on the same plant rather than allogenetic recognition. The observed physiological coordination is based on an as yet unknown mechanism and has important ecological implications, because it allows the avoidance of competition with self and the allocation of greater resources to alternative functions. PMID:15004281

Modulation of ionotropic glutamate receptor function by vertebrate galectins.

PubMed

Copits, Bryan A; Vernon, Claire G; Sakai, Ryuichi; Swanson, Geoffrey T

2014-05-15

AMPA and kainate receptors are glutamate-gated ion channels whose function is known to be altered by a variety of plant oligosaccharide-binding proteins, or lectins, but the physiological relevance of this activity has been uncertain because no lectins with analogous allosteric modulatory effects have been identified in animals. We report here that members of the prototype galectin family, which are β-galactoside-binding lectins, exhibit subunit-specific allosteric modulation of desensitization of recombinant homomeric and heteromeric AMPA and kainate receptors. Galectin modulation of GluK2 kainate receptors was dependent upon complex oligosaccharide processing of N-glycosylation sites in the amino-terminal domain and downstream linker region. The sensitivity of GluA4 AMPA receptors to human galectin-1 could be enhanced by supplementation of culture media with uridine and N-acetylglucosamine (GlcNAc), precursors for the hexosamine pathway that supplies UDP-GlcNAc for synthesis of complex oligosaccharides. Neuronal kainate receptors in dorsal root ganglia were sensitive to galectin modulation, whereas AMPA receptors in cultured hippocampal neurons were insensitive, which could be a reflection of differential N-glycan processing or receptor subunit selectivity. Because glycan content of integral proteins can be modified dynamically, we postulate that physiological or pathological conditions in the CNS could arise in which galectins alter excitatory neurotransmission or neuronal excitability through their actions on AMPA or kainate receptors. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Cryptococcus neoformans Mediator Protein Ssn8 Negatively Regulates Diverse Physiological Processes and Is Required for Virulence

PubMed Central

Wang, Lin-Ing; Lin, Yu-Sheng; Liu, Kung-Hung; Jong, Ambrose Y.; Shen, Wei-Chiang

2011-01-01

Cryptococcus neoformans is a ubiquitously distributed human pathogen. It is also a model system for studying fungal virulence, physiology and differentiation. Light is known to inhibit sexual development via the evolutionarily conserved white collar proteins in C. neoformans. To dissect molecular mechanisms regulating this process, we have identified the SSN8 gene whose mutation suppresses the light-dependent CWC1 overexpression phenotype. Characterization of sex-related phenotypes revealed that Ssn8 functions as a negative regulator in both heterothallic a-α mating and same-sex mating processes. In addition, Ssn8 is involved in the suppression of other physiological processes including invasive growth, and production of capsule and melanin. Interestingly, Ssn8 is also required for the maintenance of cell wall integrity and virulence. Our gene expression studies confirmed that deletion of SSN8 results in de-repression of genes involved in sexual development and melanization. Epistatic and yeast two hybrid studies suggest that C. neoformans Ssn8 plays critical roles downstream of the Cpk1 MAPK cascade and Ste12 and possibly resides at one of the major branches downstream of the Cwc complex in the light-mediated sexual development pathway. Taken together, our studies demonstrate that the conserved Mediator protein Ssn8 functions as a global regulator which negatively regulates diverse physiological and developmental processes and is required for virulence in C. neoformans. PMID:21559476

Hemolymph proteome changes during worker brood development match the biological divergences between western honey bees (Apis mellifera) and eastern honey bees (Apis cerana).

PubMed

Feng, Mao; Ramadan, Haitham; Han, Bin; Fang, Yu; Li, Jianke

2014-07-05

Hemolymph plays key roles in honey bee molecule transport, immune defense, and in monitoring the physiological condition. There is a lack of knowledge regarding how the proteome achieves these biological missions for both the western and eastern honey bees (Apis mellifera and Apis cerana). A time-resolved proteome was compared using two-dimensional electrophoresis-based proteomics to reveal the mechanistic differences by analysis of hemolymph proteome changes between the worker bees of two bee species during the larval to pupal stages. The brood body weight of Apis mellifera was significantly heavier than that of Apis cerana at each developmental stage. Significantly, different protein expression patterns and metabolic pathways were observed in 74 proteins (166 spots) that were differentially abundant between the two bee species. The function of hemolymph in energy storage, odor communication, and antioxidation is of equal importance for the western and eastern bees, indicated by the enhanced expression of different protein species. However, stronger expression of protein folding, cytoskeletal and developmental proteins, and more highly activated energy producing pathways in western bees suggests that the different bee species have developed unique strategies to match their specific physiology using hemolymph to deliver nutrients and in immune defense. Our disparate findings constitute a proof-of-concept of molecular details that the ecologically shaped different physiological conditions of different bee species match with the hemolymph proteome during the brood stage. This also provides a starting point for future research on the specific hemolymph proteins or pathways related to the differential phenotypes or physiology.

S-2-hydroxyglutarate regulates CD8+ T-lymphocyte fate.

PubMed

Tyrakis, Petros A; Palazon, Asis; Macias, David; Lee, Kian L; Phan, Anthony T; Veliça, Pedro; You, Jia; Chia, Grace S; Sim, Jingwei; Doedens, Andrew; Abelanet, Alice; Evans, Colin E; Griffiths, John R; Poellinger, Lorenz; Goldrath, Ananda W; Johnson, Randall S

2016-12-08

R-2-hydroxyglutarate accumulates to millimolar levels in cancer cells with gain-of-function isocitrate dehydrogenase 1/2 mutations. These levels of R-2-hydroxyglutarate affect 2-oxoglutarate-dependent dioxygenases. Both metabolite enantiomers, R- and S-2-hydroxyglutarate, are detectible in healthy individuals, yet their physiological function remains elusive. Here we show that 2-hydroxyglutarate accumulates in mouse CD8 + T cells in response to T-cell receptor triggering, and accumulates to millimolar levels in physiological oxygen conditions through a hypoxia-inducible factor 1-alpha (HIF-1α)-dependent mechanism. S-2-hydroxyglutarate predominates over R-2-hydroxyglutarate in activated T cells, and we demonstrate alterations in markers of CD8 + T-cell differentiation in response to this metabolite. Modulation of histone and DNA demethylation, as well as HIF-1α stability, mediate these effects. S-2-hydroxyglutarate treatment greatly enhances the in vivo proliferation, persistence and anti-tumour capacity of adoptively transferred CD8 + T cells. Thus, S-2-hydroxyglutarate acts as an immunometabolite that links environmental context, through a metabolic-epigenetic axis, to immune fate and function.

The immunometabolite S-2-hydroxyglutarate regulates CD8+ T-lymphocyte fate

PubMed Central

Tyrakis, Petros A.; Palazon, Asis; Macias, David; Lee, Kian. L.; Phan, Anthony. T.; Veliça, Pedro; You, Jia; Chia, Grace S.; Sim, Jingwei; Doedens, Andrew; Abelanet, Alice; Evans, Colin E.; Griffiths, John R.; Poellinger, Lorenz; Goldrath, Ananda. W.; Johnson, Randall S.

2016-01-01

R-2-hydroxyglutarate accumulates to millimolar levels in cancers with gain-of-function isocitrate dehydrogenase 1/2 mutations. These levels of R-2-hydroxyglutarate affect 2-oxoglutarate-dependent dioxygenases. Both R- and S-2-hydroxyglutarate, the other enantiomer of this metabolite, are detectible in healthy individuals, yet their physiological function remains elusive. Here we show that CD8+ T-lymphocytes accumulate 2-hydroxyglutarate in response to T-cell receptor triggering. This increases to millimolar levels in physiological oxygen conditions, via a hypoxia inducible factor 1 alpha-dependent mechanism. S-2-hydroxyglutarate predominates over R-2-hydroxyglutarate in activated T cells, and we demonstrate alterations in markers of CD8+ T-lymphocyte differentiation in response to this metabolite. Modulation of histone and DNA demethylation as well as hypoxia inducible factor 1 alpha stability mediate these effects. S-2-hydroxyglutarate treatment greatly enhances the in vivo proliferation, persistence and anti-tumour capacity of adoptively transferred CD8+ T-lymphocytes. Thus S-2-hydroxyglutarate acts as an immunometabolite that links environmental context, via a metabolic-epigenetic axis, to immune fate and function. PMID:27798602

Microglia in CNS development: Shaping the brain for the future.

PubMed

Mosser, Coralie-Anne; Baptista, Sofia; Arnoux, Isabelle; Audinat, Etienne

Microglial cells are the resident macrophages of the central nervous system (CNS) and are mainly known for their roles in neuropathologies. However, major recent developments have revealed that these immune cells actively interact with neurons in physiological conditions and can modulate the fate and functions of synapses. Originating from myeloid precursors born in the yolk sac, microglial cells invade the CNS during early embryonic development. As a consequence they can potentially influence neuronal proliferation, migration and differentiation as well as the formation and maturation of neuronal networks, thereby contributing to the entire shaping of the CNS. We review here recent evidence indicating that microglial cells are indeed involved in crucial steps of the CNS development, including neuronal survival and apoptosis, axonal growth, migration of neurons, pruning of supernumerary synapses and functional maturation of developing synapses. We also discuss current hypotheses proposing that diverting microglial cells of their physiological functions, by promoting the expression of an immune phenotype during development, may be central to neurodevelopmental disorders such as autism, schizophrenia and epilepsy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Signaling, physiological functions and clinical relevance of the G protein-coupled estrogen receptor GPER.

PubMed

Prossnitz, Eric R; Barton, Matthias

2009-09-01

GPR30, now named GPER1 (G protein-coupled estrogen receptor1) or GPER here, was first identified as an orphan 7-transmembrane G protein-coupled receptor by multiple laboratories using either homology cloning or differential expression and subsequently shown to be required for estrogen-mediated signaling in certain cancer cells. The actions of estrogen are extensive in the body and are thought to be mediated predominantly by classical nuclear estrogen receptors that act as transcription factors/regulators. Nevertheless, certain aspects of estrogen function remain incompatible with the generally accepted mechanisms of classical estrogen receptor action. Many recent studies have revealed that GPER contributes to some of the actions of estrogen, including rapid signaling events and rapid transcriptional activation. With the introduction of GPER-selective ligands and GPER knockout mice, the functions of GPER are becoming more clearly defined. In many cases, there appears to be a complex interplay between the two receptor systems, suggesting that estrogen-mediated physiological responses may be mediated by either receptor or a combination of both receptor types, with important medical implications.

Genomic and non-genomic effects of androgens in the cardiovascular system: clinical implications.

PubMed

Lucas-Herald, Angela K; Alves-Lopes, Rheure; Montezano, Augusto C; Ahmed, S Faisal; Touyz, Rhian M

2017-07-01

The principle steroidal androgens are testosterone and its metabolite 5α-dihydrotestosterone (DHT), which is converted from testosterone by the enzyme 5α-reductase. Through the classic pathway with androgens crossing the plasma membrane and binding to the androgen receptor (AR) or via mechanisms independent of the ligand-dependent transactivation function of nuclear receptors, testosterone induces genomic and non-genomic effects respectively. AR is widely distributed in several tissues, including vascular endothelial and smooth muscle cells. Androgens are essential for many developmental and physiological processes, especially in male reproductive tissues. It is now clear that androgens have multiple actions besides sex differentiation and sexual maturation and that many physiological systems are influenced by androgens, including regulation of cardiovascular function [nitric oxide (NO) release, Ca 2+ mobilization, vascular apoptosis, hypertrophy, calcification, senescence and reactive oxygen species (ROS) generation]. This review focuses on evidence indicating that interplay between genomic and non-genomic actions of testosterone may influence cardiovascular function. © 2017 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Cortical Activation in Response to Pure Taste Stimuli During the Physiological States of Hunger and Satiety

PubMed Central

Haase, Lori; Cerf-Ducastel, Barbara; Murphy, Claire

2009-01-01

This event-related functional magnetic resonance imaging (er-fMRI) study investigated BOLD signal change in response to a series of pure gustatory stimuli that varied in stimulus quality when subjects were hungry and sated with a nutritional preload. Group analyses showed significant differences in activation in the hunger minus satiety condition in response to sucrose, caffeine, saccharin, and citric acid within the thalamus, hippocampus, and parahippocampus. When examining the hunger and satiety conditions, activation varied as a function of stimulus, with the majority of the stimuli exhibiting significantly greater activation in the hunger state within the insula, thalamus, and substantia nigra, in contrast to decreased activation in the satiated state within the parahippocampus, hippocampus, amygdala, and anterior cingulate. Region of interest (ROI) analysis revealed two significant interactions, ROI by physiology and ROI by physiology by stimulus. In the satiety condition, the primary (inferior and superior insulae) and secondary (OFC 11 and OFC 47) taste regions exhibited significantly greater brain activation in response to all stimuli than regions involved in processing eating behavior (hypothalamus), affect (amygdala), and memory (hippocampus, parahippocampus and entorhinal cortex). These same regions demonstrated significantly greater activation within the hunger condition than the satiety condition, with the exception of the superior insula. Furthermore, the patterns of activation differed as a function taste stimulus, with greater activation in response to sucrose than to the other stimuli. These differential patterns of activation suggest that the physiological states of hunger and satiety produce divergent activation in multiple brain areas in response to different pure gustatory stimuli. PMID:19007893

Cortical activation in response to pure taste stimuli during the physiological states of hunger and satiety.

PubMed

Haase, Lori; Cerf-Ducastel, Barbara; Murphy, Claire

2009-02-01

This event-related functional magnetic resonance imaging (er-fMRI) study investigated BOLD signal change in response to a series of pure gustatory stimuli that varied in stimulus quality when subjects were hungry and sated with a nutritional pre-load. Group analyses showed significant differences in activation in the hunger minus satiety condition in response to sucrose, caffeine, saccharin, and citric acid within the thalamus, hippocampus, and parahippocampus. When examining the hunger and satiety conditions, activation varied as a function of stimulus, with the majority of the stimuli exhibiting significantly greater activation in the hunger state within the insula, thalamus, and substantia nigra, in contrast to decreased activation in the satiated state within the parahippocampus, hippocampus, amygdala, and anterior cingulate. Region of interest (ROI) analysis revealed two significant interactions, ROI by physiology and ROI by physiology by stimulus. In the satiety condition, the primary (inferior and superior insulae) and secondary (OFC 11 and OFC 47) taste regions exhibited significantly greater brain activation in response to all stimuli than regions involved in processing eating behavior (hypothalamus), affect (amygdala), and memory (hippocampus, parahippocampus and entorhinal cortex). These same regions demonstrated significantly greater activation within the hunger condition than the satiety condition, with the exception of the superior insula. Furthermore, the patterns of activation differed as a function taste stimulus, with greater activation in response to sucrose than to the other stimuli. These differential patterns of activation suggest that the physiological states of hunger and satiety produce divergent activation in multiple brain areas in response to different pure gustatory stimuli.

Automated Real-Time Behavioral and Physiological Data Acquisition and Display Integrated with Stimulus Presentation for fMRI

PubMed Central

Voyvodic, James T.; Glover, Gary H.; Greve, Douglas; Gadde, Syam

2011-01-01

Functional magnetic resonance imaging (fMRI) is based on correlating blood oxygen-level dependent (BOLD) signal fluctuations in the brain with other time-varying signals. Although the most common reference for correlation is the timing of a behavioral task performed during the scan, many other behavioral and physiological variables can also influence fMRI signals. Variations in cardiac and respiratory functions in particular are known to contribute significant BOLD signal fluctuations. Variables such as skin conduction, eye movements, and other measures that may be relevant to task performance can also be correlated with BOLD signals and can therefore be used in image analysis to differentiate multiple components in complex brain activity signals. Combining real-time recording and data management of multiple behavioral and physiological signals in a way that can be routinely used with any task stimulus paradigm is a non-trivial software design problem. Here we discuss software methods that allow users control of paradigm-specific audio–visual or other task stimuli combined with automated simultaneous recording of multi-channel behavioral and physiological response variables, all synchronized with sub-millisecond temporal accuracy. We also discuss the implementation and importance of real-time display feedback to ensure data quality of all recorded variables. Finally, we discuss standards and formats for storage of temporal covariate data and its integration into fMRI image analysis. These neuroinformatics methods have been adopted for behavioral task control at all sites in the Functional Biomedical Informatics Research Network (FBIRN) multi-center fMRI study. PMID:22232596

Evidence for vestibular regulation of autonomic functions in a mouse genetic model

NASA Technical Reports Server (NTRS)

Murakami, Dean M.; Erkman, Linda; Hermanson, Ola; Rosenfeld, Michael G.; Fuller, Charles A.

2002-01-01

Physiological responses to changes in the gravitational field and body position, as well as symptoms of patients with anxiety-related disorders, have indicated an interrelationship between vestibular function and stress responses. However, the relative significance of cochlear and vestibular information in autonomic regulation remains unresolved because of the difficulties in distinguishing the relative contributions of other proprioceptive and interoceptive inputs, including vagal and somatic information. To investigate the role of cochlear and vestibular function in central and physiological responses, we have examined the effects of increased gravity in wild-type mice and mice lacking the POU homeodomain transcription factor Brn-3.1 (Brn-3bPou4f3). The only known phenotype of the Brn-3.1(-/-) mouse is related to hearing and balance functions, owing to the failure of cochlear and vestibular hair cells to differentiate properly. Here, we show that normal physiological responses to increased gravity (2G exposure), such as a dramatic drop in body temperature and concomitant circadian adjustment, were completely absent in Brn-3.1(-/-) mice. In line with the lack of autonomic responses, the massive increase in neuronal activity after 2G exposure normally detected in wild-type mice was virtually abolished in Brn-3.1(-/-) mice. Our results suggest that cochlear and vestibular hair cells are the primary regulators of autonomic responses to altered gravity and provide genetic evidence that these cells are sufficient to alter neural activity in regions involved in autonomic and neuroendocrine control.

Sex-Based Differences in Skeletal Muscle Kinetics and Fiber-Type Composition

PubMed Central

Haizlip, K. M.; Harrison, B. C.

2015-01-01

Previous studies have identified over 3,000 genes that are differentially expressed in male and female skeletal muscle. Here, we review the sex-based differences in skeletal muscle fiber composition, myosin heavy chain expression, contractile function, and the regulation of these physiological differences by thyroid hormone, estrogen, and testosterone. The findings presented lay the basis for the continued work needed to fully understand the skeletal muscle differences between males and females. PMID:25559153

Directed 3D Cell Alignment and Elongation in Microengineered Hydrogels

DTIC Science & Technology

2010-01-01

Merok J, Vunjak- Novakovic G, Freed LE. Tissue engineering of functional cardiac muscle: molecular, structural, and electro- physiological studies. Am J...endothelial cells and smooth muscle cells. J Biomech 2004;37(4):531e9. [4] Vunjak- Novakovic G, Altman G, Horan R, Kaplan DL. Tissue engineering of...483e95. [9] Burdick JA, Vunjak- Novakovic G. Engineered microenvironments for controlled stem cell differentiation. Tissue Eng Part A 2009;15(2):205e19

Receptor for advanced glycation endproducts (RAGE) maintains pulmonary structure and regulates the response to cigarette smoke.

PubMed

Wolf, Lisa; Herr, Christian; Niederstraßer, Julia; Beisswenger, Christoph; Bals, Robert

2017-01-01

The receptor for advanced glycation endproducts (RAGE) is highly expressed in the lung but its physiological functions in this organ is still not completely understood. To determine the contribution of RAGE to physiological functions of the lung, we analyzed pulmonary mechanics and structure of wildtype and RAGE deficient (RAGE-/-) mice. RAGE deficiency spontaneously resulted in a loss of lung structure shown by an increased mean chord length, increased respiratory system compliance, decreased respiratory system elastance and increased concentrations of serum protein albumin in bronchoalveolar lavage fluids. Pulmonary expression of RAGE was mainly localized on alveolar epithelial cells and alveolar macrophages. Primary murine alveolar epithelial cells isolated from RAGE-/- mice revealed an altered differentiation and defective barrier formation under in vitro conditions. Stimulation of interferone-y (IFNy)-activated alveolar macrophages deficient for RAGE with Toll-like receptor (TLR) ligands resulted in significantly decreased release of proinflammatory cytokines and chemokines. Exposure to chronic cigarette smoke did not affect emphysema-like changes in lung parenchyma in RAGE-/- mice. Acute cigarette smoke exposure revealed a modified inflammatory response in RAGE-/- mice that was characterized by an influx of macrophages and a decreased keratinocyte-derived chemokine (KC) release. Our data suggest that RAGE regulates the differentiation of alveolar epithelial cells and impacts on the development and maintenance of pulmonary structure. In cigarette smoke-induced lung pathology, RAGE mediates inflammation that contributes to lung damage.

A controlled comparison of emotional reactivity and physiological response in masticatory muscle pain patients.

PubMed

Schmidt, John E; Carlson, Charles R

2009-01-01

To investigate (1) differences in heart rate variability (HRV) indices between masticatory muscle pain (MMP) patients and pain-free controls at rest, during a stressor condition, and during a post-stressor recovery period, and (2) factors including psychological distress, social environment, and family-of-origin characteristics in the MMP sample compared to a pain-free matched control sample. Physiological activation and emotional reactivity were assessed in 22 MMP patients and 23 controls during baseline, stressor, and recovery periods. Physiological activity was assessed with frequency domain HRV indices. Emotional reactivity was assessed with the Emotional Assessment Scale. Analytic strategy began with overall 2 x 3 multivariate analyses of variance on physiological data followed by focused contrasts to test specific hypotheses regarding physiological and emotional status. Hypothesized differences between study groups on psychological and social-environmental variables were compared with univariate analyses of variance. The MMP patients showed physiological activation during the baseline period and significantly more physiological activation during the recovery period compared to the controls. This pattern was also present in emotional reactivity between the groups. The emotional and physiological differences between the groups across study periods were more pronounced in pain patients reporting a traumatic stressor. These results provide further evidence of physiological activation and emotional responding in MMP patients that differentiates them from matched pain-free controls. The use of HRV indices to measure physiological functioning quantifies the degree of sympathetic and parasympathetic activation. Study results suggest the use of these HRV indices may improve understanding of the role of excitatory and inhibitory mechanisms in patients with MMP conditions.

Analysis of drought-responsive signalling network in two contrasting rice cultivars using transcriptome-based approach

PubMed Central

Borah, Pratikshya; Sharma, Eshan; Kaur, Amarjot; Chandel, Girish; Mohapatra, Trilochan; Kapoor, Sanjay; Khurana, Jitendra P.

2017-01-01

Traditional cultivars of rice in India exhibit tolerance to drought stress due to their inherent genetic variations. Here we present comparative physiological and transcriptome analyses of two contrasting cultivars, drought tolerant Dhagaddeshi (DD) and susceptible IR20. Microarray analysis revealed several differentially expressed genes (DEGs) exclusively in DD as compared to IR20 seedlings exposed to 3 h drought stress. Physiologically, DD seedlings showed higher cell membrane stability and differential ABA accumulation in response to dehydration, coupled with rapid changes in gene expression. Detailed analyses of metabolic pathways enriched in expression data suggest interplay of ABA dependent along with secondary and redox metabolic networks that activate osmotic and detoxification signalling in DD. By co-localization of DEGs with QTLs from databases or published literature for physiological traits of DD and IR20, candidate genes were identified including those underlying major QTL qDTY1.1 in DD. Further, we identified previously uncharacterized genes from both DD and IR20 under drought conditions including OsWRKY51, OsVP1 and confirmed their expression by qPCR in multiple rice cultivars. OsFBK1 was also functionally validated in susceptible PB1 rice cultivar and Arabidopsis for providing drought tolerance. Some of the DEGs mapped to the known QTLs could thus, be of potential significance for marker-assisted breeding. PMID:28181537

Fabrication of a co-culture micro-bioreactor device for efficient hepatic differentiation of human induced pluripotent stem cells (hiPSCs).

PubMed

Kehtari, Mousa; Zeynali, Bahman; Soleimani, Masoud; Kabiri, Mahboubeh; Seyedjafari, Ehsan

2018-04-27

Primary hepatocytes, as the gold standard cell type for in vitro models, lose their characteristic morphology and functions after few days. There is an urgent need to develop physiologically relevant models that recapitulate liver microenvironment to obtain mature hepatocyte from stem cells. We designed and fabricated a micro-bioreactor device mimicking the physiological shear stress and cell-cell interaction in liver sinusoid microenvironment. Induced pluripotent stem cells (iPSCs) were co-cultured with human umbilical vein endothelial cells (HUVECs) in the micro-bioreactor device with continuous perfusion of hepatic differentiation medium (100 μL/h). Simulation results showed that flow field inside our perfusion device was uniform and shear stress was adjusted to physiological condition (<2 dyne/cm 2 ). IPSCs-derived hepatocytes (iPSCs-Heps) that were cultured in micro-bioreactor device showed a higher level of hepatic markers compared to those in static condition. Flow cytometry and immunocytochemistry analysis revealed iPSCs cultured in the device sequentially acquired characteristics of definitive endodermal cells (SOX17 positive), hepatoblasts (AFP positive) and mature hepatocyte (ALB positive). Moreover, the albumin and urea secretion were significantly higher in micro-bioreactor device than those cultured in culture dishes during experiment. Thus, based on our results, we propose our micro-bioreactor as a beneficial device to generate mature hepatocytes for drug screening and basic research.

Stressor-Specific Alterations in Corticosterone and Immune Responses in Mice

PubMed Central

Bowers, Stephanie L.; Bilbo, Staci D.; Dhabhar, Firdaus S.; Nelson, Randy J.

2007-01-01

Different stressors likely elicit different physiological and behavioral responses. Previously reported differences in the effects of stressors on immune function may reflect qualitatively different physiological responses to stressors; alternatively, both large and subtle differences in testing protocols and methods among laboratories may make direct comparisons among studies difficult. Here we examine the effects of chronic stressors on plasma corticosterone concentrations, leukocyte redistribution, and skin delayed-type hypersensitivity (DTH) and the effects of acute stressors on plasma corticosterone and leukocyte redistribution. The effects of several commonly used laboratory stressors including restraint, forced swim, isolation, and low ambient temperatures (4°C) were examined. Exposure to each stressor elevated corticosterone concentrations, with restraint (a putative psychological stressor) evoking a significantly higher glucocorticoid response than other stressors. Chronic restraint and forced swim enhanced the DTH response compared to the handled, low temperature, or isolation conditions. Restraint, low temperature, and isolation significantly increased trafficking of lymphocytes and monocytes compared to forced swim or handling. Generally, acute restraint, low temperature, isolation, and handling increased trafficking of lymphocytes and monocytes. Considered together, our results suggest that the different stressors commonly used in psychoneuroimmunology research may not activate the physiological stress response to the same extent. The variation observed in the measured immune responses may reflect differential glucocorticoid activation, differential metabolic adjustments, or both processes in response to specific stressors. PMID:17890050

Factors circulating in the blood of type 2 diabetes mellitus patients affect osteoblast maturation – Description of a novel in vitro model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ehnert, Sabrina, E-mail: sabrina.ehnert@gmail.com; Freude, Thomas, E-mail: tfreude@bgu-tuebingen.de; Ihle, Christoph, E-mail: cihle@bgu-tuebingen.de

Type 2 diabetes mellitus (T2DM) is one of the most frequent metabolic disorders in industrialized countries. Among other complications, T2DM patients have an increased fracture risk and delayed fracture healing. We have demonstrated that supraphysiological glucose and insulin levels inhibit primary human osteoblasts' maturation. We aimed at developing a more physiologically relevant in vitro model to analyze T2DM-mediated osteoblast changes. Therefore, SCP-1-immortalized pre-osteoblasts were differentiated with T2DM or control (non-obese and obese) sera. Between both control groups, no significant changes were observed. Proliferation was significantly increased (1.69-fold), while AP activity and matrix mineralization was significantly reduced in the T2DM group.more » Expression levels of osteogenic marker genes and transcription factors were altered, e.g. down-regulation of RUNX2 and SP-7 or up-regulation of STAT1, in the T2DM group. Active TGF-β levels were significantly increased (1.46-fold) in T2DM patients' sera. SCP-1 cells treated with these sera showed significantly increased TGF-β signaling (2.47-fold). Signaling inhibition effectively restored osteoblast maturation in the T2DM group. Summarizing our data, SCP-1 cells differentiated in the presence of T2DM patients' serum exhibit reduced osteoblast function. Thus, this model has a high physiological impact, as it can identify circulating factors in T2DM patients' blood that may affect bone function, e.g. TGF-β. - Highlights: • We present here a physiologically relevant in vitro model for diabetic osteopathy. • Blood of T2DM patients contains factors that affect osteoblasts' function. • The model developed here can be used to identify these factors, e.g. TGF-β. • Blocking TGF-β signaling partly rescues the osteoblasts' function in the T2DM group. • The model is useful to demonstrate the role of single factors in diabetic osteopathy.« less

Promises and challenges of eco-physiological genomics in the field: tests of drought responses in switchgrass

DOE PAGES

Lovell, John T.; Shakirov, Eugene V.; Schwartz, Scott; ...

2016-05-31

Identifying the physiological and genetic basis of stress tolerance in plants has proven to be critical to understanding adaptation in both agricultural and natural systems. However, many discoveries were initially made in the controlled conditions of greenhouses or laboratories, not in the field. To test the comparability of drought responses across field and greenhouse environments, we undertook three independent experiments using the switchgrass reference genotype Alamo AP13. We analyzed physiological and gene expression variation across four locations, two sampling times, and three years. Relatively similar physiological responses and expression coefficients of variation across experiments masked highly dissimilar gene expression responsesmore » to drought. Critically, a drought experiment utilizing small pots in the greenhouse elicited nearly identical physiological changes as an experiment conducted in the field, but an order of magnitude more differentially expressed genes. However, we were able to define a suite of several hundred genes that were differentially expressed across all experiments. This list was strongly enriched in photosynthesis, water status, and reactive oxygen species responsive genes. The strong across-experiment correlations between physiological plasticity—but not differential gene expression—highlight the complex and diverse genetic mechanisms that can produce phenotypically similar responses to various soil water deficits.« less

Promises and Challenges of Eco-Physiological Genomics in the Field: Tests of Drought Responses in Switchgrass1[OPEN

PubMed Central

Schwartz, Scott; Lowry, David B.; Aspinwall, Michael J.; Palacio-Mejia, Juan Diego; Hawkes, Christine V.; Fay, Philip A.

2016-01-01

Identifying the physiological and genetic basis of stress tolerance in plants has proven to be critical to understanding adaptation in both agricultural and natural systems. However, many discoveries were initially made in the controlled conditions of greenhouses or laboratories, not in the field. To test the comparability of drought responses across field and greenhouse environments, we undertook three independent experiments using the switchgrass reference genotype Alamo AP13. We analyzed physiological and gene expression variation across four locations, two sampling times, and three years. Relatively similar physiological responses and expression coefficients of variation across experiments masked highly dissimilar gene expression responses to drought. Critically, a drought experiment utilizing small pots in the greenhouse elicited nearly identical physiological changes as an experiment conducted in the field, but an order of magnitude more differentially expressed genes. However, we were able to define a suite of several hundred genes that were differentially expressed across all experiments. This list was strongly enriched in photosynthesis, water status, and reactive oxygen species responsive genes. The strong across-experiment correlations between physiological plasticity—but not differential gene expression—highlight the complex and diverse genetic mechanisms that can produce phenotypically similar responses to various soil water deficits. PMID:27246097

Transcriptional, translational, and physiological signatures of undernourished honey bees (Apis mellifera) suggest a role for hormonal factors in hypopharyngeal gland degradation.

PubMed

Corby-Harris, Vanessa; Meador, Charlotte A D; Snyder, Lucy A; Schwan, Melissa R; Maes, Patrick; Jones, Beryl M; Walton, Alexander; Anderson, Kirk E

2016-02-01

Honey bee colonies function as a superorganism, where facultatively sterile female workers perform various tasks that support the hive. Nurse workers undergo numerous anatomical and physiological changes in preparation for brood rearing, including the growth of hypopharyngeal glands (HGs). These glands produce the major protein fraction of a protein- and lipid-rich jelly used to sustain developing larvae. Pollen intake is positively correlated with HG growth, but growth in the first three days is similar regardless of diet, suggesting that initial growth is a pre-determined process while later HG development depends on nutrient availability during a critical window in early adulthood (>3 d). It is unclear whether the resultant size differences in nurse HG are simply due to growth arrest or active degradation of the tissue. To determine what processes cause such differences in HG size, we catalogued the differential expression of both gene transcripts and proteins in the HGs of 8 d old bees that were fed diets containing pollen or no pollen. 3438 genes and 367 proteins were differentially regulated due to nutrition. Of the genes and proteins differentially expressed, undernourished bees exhibited more gene and protein up-regulation compared to well-nourished bees, with the affected processes including salivary gland apoptosis, oogenesis, and hormone signaling. Protein secretion was virtually the only process up-regulated in well-nourished bees. Further assays demonstrated that inhibition of ultraspiracle, one component of the ecdysteroid receptor, in the fat body caused larger HGs. Undernourished bees also had higher acid phosphatase activity, a physiological marker of cell death, compared to well-nourished bees. These results support a connection between poor nutrition, hormonal signaling, and HG degradation. Published by Elsevier Ltd.

A New Conditionally Immortalized Human Fetal Brain Pericyte Cell Line: Establishment and Functional Characterization as a Promising Tool for Human Brain Pericyte Studies.

PubMed

Umehara, Kenta; Sun, Yuchen; Hiura, Satoshi; Hamada, Koki; Itoh, Motoyuki; Kitamura, Keita; Oshima, Motohiko; Iwama, Atsushi; Saito, Kosuke; Anzai, Naohiko; Chiba, Kan; Akita, Hidetaka; Furihata, Tomomi

2018-07-01

While pericytes wrap around microvascular endothelial cells throughout the human body, their highest coverage rate is found in the brain. Brain pericytes actively contribute to various brain functions, including the development and stabilization of the blood-brain barrier (BBB), tissue regeneration, and brain inflammation. Accordingly, detailed characterization of the functional nature of brain pericytes is important for understanding the mechanistic basis of brain physiology and pathophysiology. Herein, we report on the development of a new human brain pericyte cell line, hereafter referred to as the human brain pericyte/conditionally immortalized clone 37 (HBPC/ci37). Developed via the cell conditionally immortalization method, these cells exhibited excellent proliferative ability at 33 °C. However, when cultured at 37 °C, HBPC/ci37 cells showed a differentiated phenotype that was marked by morphological alterations and increases in several pericyte-enriched marker mRNA levels, such as platelet-derived growth factor receptor β. It was also found that HBPC/ci37 cells possessed the facilitative ability of in vitro BBB formation and differentiation into a neuronal lineage. Furthermore, HBPC/ci37 cells exhibited the typical "reactive" features of brain pericytes in response to pro-inflammatory cytokines. To summarize, our results clearly demonstrate that HBPC/ci37 cells possess the ability to perform several key brain pericyte functions while also showing the capacity for extensive and continuous proliferation. Based on these findings, it can be expected that, as a unique human brain pericyte model, HBPC/ci37 cells have the potential to contribute to significant advances in the understanding of human brain pericyte physiology and pathophysiology.

Regulation of Tissue Growth by the Mammalian Hippo Signaling Pathway

PubMed Central

Watt, Kevin I.; Harvey, Kieran F.; Gregorevic, Paul

2017-01-01

The integrative control of diverse biological processes such as proliferation, differentiation, apoptosis and metabolism is essential to maintain cellular and tissue homeostasis. Disruption of these underlie the development of many disease states including cancer and diabetes, as well as many of the complications that arise as a consequence of aging. These biological outputs are governed by many cellular signaling networks that function independently, and in concert, to convert changes in hormonal, mechanical and metabolic stimuli into alterations in gene expression. First identified in Drosophila melanogaster as a powerful mediator of cell division and apoptosis, the Hippo signaling pathway is a highly conserved regulator of mammalian organ size and functional capacity in both healthy and diseased tissues. Recent studies have implicated the pathway as an effector of diverse physiological cues demonstrating an essential role for the Hippo pathway as an integrative component of cellular homeostasis. In this review, we will: (a) outline the critical signaling elements that constitute the mammalian Hippo pathway, and how they function to regulate Hippo pathway-dependent gene expression and tissue growth, (b) discuss evidence that shows this pathway functions as an effector of diverse physiological stimuli and (c) highlight key questions in this developing field. PMID:29225579

A Driving Bioinformatics Approach to Explore Co-regulation of AOX Gene Family Members During Growth and Development.

PubMed

Costa, José Hélio; Arnholdt-Schmitt, Birgit

2017-01-01

The alternative oxidase (AOX) gene family is a hot candidate for functional marker development that could help plant breeding on yield stability through more robust plants based on multi-stress tolerance. However, there is missing knowledge on the interplay between gene family members that might interfere with the efficiency of marker development. It is common view that AOX1 and AOX2 have different physiological roles. Nevertheless, both family member groups act in terms of molecular-biochemical function as "typical" alternative oxidases and co-regulation of AOX1 and AOX2 had been reported. Although conserved sequence differences had been identified, the basis for differential effects on physiology regulation is not sufficiently explored.This protocol gives instructions for a bioinformatics approach that supports discovering potential interaction of AOX family members in regulating growth and development. It further provides a strategy to elucidate the relevance of gene sequence diversity and copy number variation for final functionality in target tissues and finally the whole plant. Thus, overall this protocol provides the means for efficiently identifying plant AOX variants as functional marker candidates related to growth and development.

Interordinal chimera formation between medaka and zebrafish for analyzing stem cell differentiation.

PubMed

Hong, Ni; Chen, Songlin; Ge, Ruowen; Song, Jianxing; Yi, Meisheng; Hong, Yunhan

2012-08-10

Chimera formation is a standard test for pluripotency of stem cells in vivo. Interspecific chimera formation between distantly related organisms offers also an attractive approach for propagating endangered species. Parameters influencing interspecies chimera formation have remained poorly elucidated. Here, we report interordinal chimera formation between medaka and zebrafish, which separated ∼320 million years ago and exhibit a more than 2-fold difference in developmental speed. We show that, on transplantation into zebrafish blastulae, both noncultivated blastomeres and long-term cultivated embryonic stem (ES) cells of medaka adopted the zebrafish developmental program and differentiated into physiologically functional cell types including pigment cells, blood cells, and cardiomyocytes. We also show that medaka ES cells express differentiation gene markers during chimeric embryogenesis. Therefore, the evolutionary distance and different embryogenesis speeds do not produce donor-host incompatibility to compromise chimera formation between medaka and zebrafish, and molecular markers are valuable for analyzing lineage commitment and cell differentiation in interspecific chimeric embryos.

Interordinal Chimera Formation Between Medaka and Zebrafish for Analyzing Stem Cell Differentiation

PubMed Central

Hong, Ni; Chen, Songlin; Ge, Ruowen; Song, Jianxing

2012-01-01

Chimera formation is a standard test for pluripotency of stem cells in vivo. Interspecific chimera formation between distantly related organisms offers also an attractive approach for propagating endangered species. Parameters influencing interspecies chimera formation have remained poorly elucidated. Here, we report interordinal chimera formation between medaka and zebrafish, which separated ∼320 million years ago and exhibit a more than 2-fold difference in developmental speed. We show that, on transplantation into zebrafish blastulae, both noncultivated blastomeres and long-term cultivated embryonic stem (ES) cells of medaka adopted the zebrafish developmental program and differentiated into physiologically functional cell types including pigment cells, blood cells, and cardiomyocytes. We also show that medaka ES cells express differentiation gene markers during chimeric embryogenesis. Therefore, the evolutionary distance and different embryogenesis speeds do not produce donor-host incompatibility to compromise chimera formation between medaka and zebrafish, and molecular markers are valuable for analyzing lineage commitment and cell differentiation in interspecific chimeric embryos. PMID:22204449

Basal p53 expression is indispensable for mesenchymal stem cell integrity.

PubMed

Boregowda, Siddaraju V; Krishnappa, Veena; Strivelli, Jacqueline; Haga, Christopher L; Booker, Cori N; Phinney, Donald G

2018-03-01

Marrow-resident mesenchymal stem cells (MSCs) serve as a functional component of the perivascular niche that regulates hematopoiesis. They also represent the main source of bone formed in adult bone marrow, and their bifurcation to osteoblast and adipocyte lineages plays a key role in skeletal homeostasis and aging. Although the tumor suppressor p53 also functions in bone organogenesis, homeostasis, and neoplasia, its role in MSCs remains poorly described. Herein, we examined the normal physiological role of p53 in primary MSCs cultured under physiologic oxygen levels. Using knockout mice and gene silencing we show that p53 inactivation downregulates expression of TWIST2, which normally restrains cellular differentiation to maintain wild-type MSCs in a multipotent state, depletes mitochondrial reactive oxygen species (ROS) levels, and suppresses ROS generation and PPARG gene and protein induction in response to adipogenic stimuli. Mechanistically, this loss of adipogenic potential skews MSCs toward an osteogenic fate, which is further potentiated by TWIST2 downregulation, resulting in highly augmented osteogenic differentiation. We also show that p53 - /- MSCs are defective in supporting hematopoiesis as measured in standard colony assays because of decreased secretion of various cytokines including CXCL12 and CSF1. Lastly, we show that transient exposure of wild-type MSCs to 21% oxygen upregulates p53 protein expression, resulting in increased mitochondrial ROS production and enhanced adipogenic differentiation at the expense of osteogenesis, and that treatment of cells with FGF2 mitigates these effects by inducing TWIST2. Together, these findings indicate that basal p53 levels are necessary to maintain MSC bi-potency, and oxygen-induced increases in p53 expression modulate cell fate and survival decisions. Because of the critical function of basal p53 in MSCs, our findings question the use of p53 null cell lines as MSC surrogates, and also implicate dysfunctional MSC responses in the pathophysiology of p53-related skeletal disorders.

Brain local and regional neuroglial alterations in Alzheimer's Disease: cell types, responses and implications.

PubMed

Toledano, Adolfo; Álvarez, María-Isabel; Toledano-Díaz, Adolfo; Merino, José-Joaquín; Rodríguez, José Julio

2016-01-01

From birth to death, neurons are dynamically accompanied by neuroglial cells in a very close morphological and functional relationship. Three families have been classically considered within the CNS: astroglia, oligodendroglia and microglia. Many types/subtypes (including NGR2+ cells), with a wide variety of physiological and pathological effects on neurons, have been described using morphological and immunocytochemical criteria. Glio-glial, glio-neuronal and neuro-glial cell signaling and gliotransmission are phenomena that are essential to support brain functions. Morphofunctional changes resulting from the plasticity of all the glial cell types parallel the plastic neuronal changes that optimize the functionality of neuronal circuits. Moreover, neuroglia possesses the ability to adopt a reactive status (gliosis) in which, generally, new functions arise to improve and restore if needed the neural functionality. All these features make neuroglial cells elements of paramount importance when attempting to explain any physiological or pathological processes in the CNS, because they are involved in both, neuroprotection/neurorepair and neurodegeneration. There exist diverse and profound, regional and local, neuroglial changes in all involutive processes (physiological and pathological aging; neurodegenerative disorders, including Alzheimer ´s disease -AD-), but today, the exact meaning of such modifications (the modifications of the different neuroglial types, in time and place), is not well understood. In this review we consider the different neuroglial cells and their responses in order to understand the possible role they fulfill in pathogenesis, diagnosis and treatment (preventive or palliative) of AD. The existence of differentiated and/or concurrent pathogenic and neuro-protective/neuro-restorative astroglial and microglial responses is highlighted.

Selective Matrix (Hyaluronan) Interaction with CD44 and RhoGTPase Signaling Promotes Keratinocyte Functions and Overcomes Age-related Epidermal Dysfunction

PubMed Central

Bourguignon, Lilly Y.W.; Wong, Gabriel; Xia, Weiliang; Man, Mao-Qiang; Holleran, Walter M.; Elias, Peter M.

2013-01-01

Background Mouse epidermal chronologic aging is closely associated with aberrant matrix (hyaluronan, HA) -size distribution/production and impaired keratinocyte proliferation/differentiation, leading to a marked thinning of the epidermis with functional consequence that causes a slower recovery of permeability barrier function. Objective The goal of this study is to demonstrate mechanism-based, corrective therapeutic strategies using topical applications of small HA (HAS) and/or large HA (HAL) [or a sequential small HA (HAS) and large HA(HAL) (HAs-»HAL) treatment] as well as RhoGTPase signaling perturbation agents to regulate HA/CD44-mediated signaling, thereby restoring normal epidermal function, and permeability barrier homeostasis in aged mouse skin. Methods A number of biochemical, cell biological/molecular, pharmacological and physiological approaches were used to investigate matrix HA-CD44-mediated RhoGTPase signaling in regulating epidermal functions and skin aging. Results In this study we demonstrated that topical application of small HA (HAS) promotes keratinocyte proliferation and increases skin thickness, while it fails to upregulate keratinocyte differentiation or permeability barrier repair in aged mouse skin. In contrast, large HA (HAL) induces only minimal changes in keratinocyte proliferation and skin thickness, but restores keratinocyte differentiation and improves permeability barrier function in aged epidermis. Since neither HAS nor HAL corrects these epidermal defects in aged CD44 knock-out mice, CD44 likely mediates HA-associated epidermal functions in aged mouse skin. Finally, blockade of Rho-kinase activity with Y27632 or protein kinase-Nγ activity with Ro31-8220 significantly decreased the HA (HAS or HAL)-mediated changes in epidermal function in aged mouse skin. Conclusion The results of our study show first that HA application of different sizes regulates epidermal proliferation, differentiation and barrier function in aged mouse skin. Second, manipulation of matrix (HA) interaction with CD44 and RhoGTPase signaling could provide further novel therapeutic approaches that could be targeted for the treatment of various aging-related skin disorders. PMID:23790635

Termination factor Rho: From the control of pervasive transcription to cell fate determination in Bacillus subtilis

PubMed Central

Nicolas, Pierre; Repoila, Francis; Bardowski, Jacek; Aymerich, Stéphane

2017-01-01

In eukaryotes, RNA species originating from pervasive transcription are regulators of various cellular processes, from the expression of individual genes to the control of cellular development and oncogenesis. In prokaryotes, the function of pervasive transcription and its output on cell physiology is still unknown. Most bacteria possess termination factor Rho, which represses pervasive, mostly antisense, transcription. Here, we investigate the biological significance of Rho-controlled transcription in the Gram-positive model bacterium Bacillus subtilis. Rho inactivation strongly affected gene expression in B. subtilis, as assessed by transcriptome and proteome analysis of a rho–null mutant during exponential growth in rich medium. Subsequent physiological analyses demonstrated that a considerable part of Rho-controlled transcription is connected to balanced regulation of three mutually exclusive differentiation programs: cell motility, biofilm formation, and sporulation. In the absence of Rho, several up-regulated sense and antisense transcripts affect key structural and regulatory elements of these differentiation programs, thereby suppressing motility and biofilm formation and stimulating sporulation. We dissected how Rho is involved in the activity of the cell fate decision-making network, centered on the master regulator Spo0A. We also revealed a novel regulatory mechanism of Spo0A activation through Rho-dependent intragenic transcription termination of the protein kinase kinB gene. Altogether, our findings indicate that distinct Rho-controlled transcripts are functional and constitute a previously unknown built-in module for the control of cell differentiation in B. subtilis. In a broader context, our results highlight the recruitment of the termination factor Rho, for which the conserved biological role is probably to repress pervasive transcription, in highly integrated, bacterium-specific, regulatory networks. PMID:28723971

Blood gene expression profiles suggest altered immune function associated with symptoms of generalized anxiety disorder.

PubMed

Wingo, Aliza P; Gibson, Greg

2015-01-01

Prospective epidemiological studies found that generalized anxiety disorder (GAD) can impair immune function and increase risk for cardiovascular disease or events. Mechanisms underlying the physiological reverberations of anxiety, however, are still elusive. Hence, we aimed to investigate molecular processes mediating effects of anxiety on physical health using blood gene expression profiles of 336 community participants (157 anxious and 179 control). We examined genome-wide differential gene expression in anxiety, as well as associations between nine major modules of co-regulated transcripts in blood gene expression and anxiety. No significant differential expression was observed in women, but 631 genes were differentially expressed between anxious and control men at the false discovery rate of 0.1 after controlling for age, body mass index, race, and batch effect. Gene set enrichment analysis (GSEA) revealed that genes with altered expression levels in anxious men were involved in response of various immune cells to vaccination and to acute viral and bacterial infection, and in a metabolic network affecting traits of metabolic syndrome. Further, we found one set of 260 co-regulated genes to be significantly associated with anxiety in men after controlling for the relevant covariates, and demonstrate its equivalence to a component of the stress-related conserved transcriptional response to adversity profile. Taken together, our results suggest potential molecular pathways that can explain negative effects of GAD observed in epidemiological studies. Remarkably, even mild anxiety, which most of our participants had, was associated with observable changes in immune-related gene expression levels. Our findings generate hypotheses and provide incremental insights into molecular mechanisms mediating negative physiological effects of GAD. Published by Elsevier Inc.

Differential effects of two phospholipase D inhibitors, 1-butanol and N-acylethanolamine, on in vivo cytoskeletal organization and Arabidopsis seedling growth.

PubMed

Motes, Christy M; Pechter, Priit; Yoo, Cheol Min; Wang, Yuh-Shuh; Chapman, Kent D; Blancaflor, Elison B

2005-12-01

Plant development is regulated by numerous chemicals derived from a multitude of metabolic pathways. However, we know very little about the biological effects and functions of many of these metabolites in the cell. N-Acylethanolamines (NAEs) are a group of lipid mediators that play important roles in mammalian physiology. Despite the intriguing similarities between animals and plants in NAE metabolism and perception, not much is known about the precise function of these metabolites in plant physiology. In plants, NAEs have been shown to inhibit phospholipase Dalpha (PLDalpha) activity, interfere with abscisic acid-induced stomatal closure, and retard Arabidopsis seedling development. 1-Butanol, an antagonist of PLD-dependent phosphatidic acid production, was reported to induce defects in Arabidopsis seedling development that were somewhat similar to effects induced by elevated levels of NAE. This raised the possibility that the impact of NAE on seedling growth could be mediated in part via its influence on PLD activity. To begin to address this possibility, we conducted a detailed, comparative analysis of the effects of 1-butanol and N-lauroylethanolamine (NAE 12:0) on Arabidopsis root cell division, in vivo cytoskeletal organization, seed germination, and seedling growth. Although both NAE 12:0 and 1-butanol induced profound cytoskeletal and morphological alterations in seedlings, there were distinct differences in their overall effects. 1-Butanol induced more pronounced modifications in cytoskeletal organization, seedling growth, and cell division at concentrations severalfold higher than NAE 12:0. We propose that these compounds mediate their differential effects on cellular organization and seedling growth, in part through the differential modulation of specific PLD isoforms.

Activation of the mitogen-activated protein kinase pathway by bone sialoprotein regulates osteoblast differentiation.

PubMed

Gordon, Jonathan A R; Hunter, Graeme K; Goldberg, Harvey A

2009-01-01

Bone sialoprotein (BSP) is an abundant protein in the extracellular matrix of bone that has been suggested to have several different physiological functions, including the nucleation of hydroxyapatite (HA), promotion of cell attachment and binding of collagen. Studies in our lab have demonstrated that increased expression of BSP in osteoblast cells can increase expression of the osteoblast-related genes Runx2 and Osx as well as alkaline phosphatase and osteocalcin and increase matrix mineralization. To determine the molecular mechanisms responsible for the BSP-mediated increase in osteoblastic differentiation, several functional domain mutants of BSP were expressed in primary rat bone osteoblastic cells, including the contiguous glutamic acid sequences (polyGlu) and the arginine-glycine-aspartic acid (RGD) motif. Markers of osteoblast differentiation, including matrix mineralization and alkaline phosphatase staining, were increased in cells expressing BSP mutants of the polyGlu sequences but not in cells expressing RGD-mutated BSP. We also determined the dependence on integrin-associated pathways in promoting BSP-mediated differentiation responses in osteoblasts by demonstrating the activation of focal adhesion kinase, MAP kinase-associated proteins ERK1/2, ribosomal s6 kinase 2 and the AP-1 protein cFos. Thus, the mechanism regulating osteoblast differentiation by BSP was determined to be dependent on integrin-mediated intracellular signaling pathways. Copyright 2008 S. Karger AG, Basel.

MCT1 and MCT4 Expression and Lactate Flux Activity Increase During White and Brown Adipogenesis and Impact Adipocyte Metabolism.

PubMed

Petersen, Charlotte; Nielsen, Mette D; Andersen, Elise S; Basse, Astrid L; Isidor, Marie S; Markussen, Lasse K; Viuff, Birgitte M; Lambert, Ian H; Hansen, Jacob B; Pedersen, Stine F

2017-10-12

Adipose tissue takes up glucose and releases lactate, thereby contributing significantly to systemic glucose and lactate homeostasis. This implies the necessity of upregulation of net acid and lactate flux capacity during adipocyte differentiation and function. However, the regulation of lactate- and acid/base transporters in adipocytes is poorly understood. Here, we tested the hypothesis that adipocyte thermogenesis, browning and differentiation are associated with an upregulation of plasma membrane lactate and acid/base transport capacity that in turn is important for adipocyte metabolism. The mRNA and protein levels of the lactate-H + transporter MCT1 and the Na + ,HCO 3 - cotransporter NBCe1 were upregulated in mouse interscapular brown and inguinal white adipose tissue upon cold induction of thermogenesis and browning. MCT1, MCT4, and NBCe1 were furthermore strongly upregulated at the mRNA and protein level upon differentiation of cultured pre-adipocytes. Adipocyte differentiation was accompanied by increased plasma membrane lactate flux capacity, which was reduced by MCT inhibition and by MCT1 knockdown. Finally, in differentiated brown adipocytes, glycolysis (assessed as ECAR), and after noradrenergic stimulation also oxidative metabolism (OCR), was decreased by MCT inhibition. We suggest that upregulation of MCT1- and MCT4-mediated lactate flux capacity and NBCe1-mediated HCO 3 - /pH homeostasis are important for the physiological function of mature adipocytes.

Substrate stiffness affects skeletal myoblast differentiation in vitro

NASA Astrophysics Data System (ADS)

Romanazzo, Sara; Forte, Giancarlo; Ebara, Mitsuhiro; Uto, Koichiro; Pagliari, Stefania; Aoyagi, Takao; Traversa, Enrico; Taniguchi, Akiyoshi

2012-12-01

To maximize the therapeutic efficacy of cardiac muscle constructs produced by stem cells and tissue engineering protocols, suitable scaffolds should be designed to recapitulate all the characteristics of native muscle and mimic the microenvironment encountered by cells in vivo. Moreover, so not to interfere with cardiac contractility, the scaffold should be deformable enough to withstand muscle contraction. Recently, it was suggested that the mechanical properties of scaffolds can interfere with stem/progenitor cell functions, and thus careful consideration is required when choosing polymers for targeted applications. In this study, cross-linked poly-ɛ-caprolactone membranes having similar chemical composition and controlled stiffness in a supra-physiological range were challenged with two sources of myoblasts to evaluate the suitability of substrates with different stiffness for cell adhesion, proliferation and differentiation. Furthermore, muscle-specific and non-related feeder layers were prepared on stiff surfaces to reveal the contribution of biological and mechanical cues to skeletal muscle progenitor differentiation. We demonstrated that substrate stiffness does affect myogenic differentiation, meaning that softer substrates can promote differentiation and that a muscle-specific feeder layer can improve the degree of maturation in skeletal muscle stem cells.

Mammalian Krüppel-Like Factors in Health and Diseases

PubMed Central

McConnell, Beth B.; Yang, Vincent W.

2010-01-01

The Krüppel-like factor (KLF) family of transcription factors regulates diverse biological processes that include proliferation, differentiation, growth, development, survival, and responses to external stress. Seventeen mammalian KLFs have been identified, and numerous studies have been published that describe their basic biology and contribution to human diseases. KLF proteins have received much attention because of their involvement in the development and homeostasis of numerous organ systems. KLFs are critical regulators of physiological systems that include the cardiovascular, digestive, respiratory, hematological, and immune systems and are involved in disorders such as obesity, cardiovascular disease, cancer, and inflammatory conditions. Furthermore, KLFs play an important role in reprogramming somatic cells into induced pluripotent stem (iPS) cells and maintaining the pluripotent state of embryonic stem cells. As research on KLF proteins progresses, additional KLF functions and associations with disease are likely to be discovered. Here, we review the current knowledge of KLF proteins and describe common attributes of their biochemical and physiological functions and their pathophysiological roles. PMID:20959618

Impaired tRNA nuclear export links DNA damage and cell-cycle checkpoint.

PubMed

Ghavidel, Ata; Kislinger, Thomas; Pogoutse, Oxana; Sopko, Richelle; Jurisica, Igor; Emili, Andrew

2007-11-30

In response to genotoxic stress, cells evoke a plethora of physiological responses collectively aimed at enhancing viability and maintaining the integrity of the genome. Here, we report that unspliced tRNA rapidly accumulates in the nuclei of yeast Saccharomyces cerevisiae after DNA damage. This response requires an intact MEC1- and RAD53-dependent signaling pathway that impedes the nuclear export of intron-containing tRNA via differential relocalization of the karyopherin Los1 to the cytoplasm. The accumulation of unspliced tRNA in the nucleus signals the activation of Gcn4 transcription factor, which, in turn, contributes to cell-cycle arrest in G1 in part by delaying accumulation of the cyclin Cln2. The regulated nucleocytoplasmic tRNA trafficking thus constitutes an integral physiological adaptation to DNA damage. These data further illustrate how signal-mediated crosstalk between distinct functional modules, namely, tRNA nucleocytoplasmic trafficking, protein synthesis, and checkpoint execution, allows for functional coupling of tRNA biogenesis and cell-cycle progression.

Sox21 deletion in mice causes postnatal growth deficiency without physiological disruption of hypothalamic-pituitary endocrine axes

PubMed Central

Cheung, Leonard Y. M.; Okano, Hideyuki

2016-01-01

The hypothalamic-pituitary axes are the coordinating centers for multiple endocrine gland functions and physiological processes. Defects in the hypothalamus or pituitary gland can cause reduced growth and severe short stature, affecting approximately 1 in 4000 children, and a large percentage of cases of pituitary hormone deficiencies do not have an identified genetic cause. SOX21 is a protein that regulates hair, neural, and trophoblast stem cell differentiation. Mice lacking Sox21 have reduced growth, but the etiology of this growth defect has not been described. We studied the expression of Sox21 in hypothalamic-pituitary development and examined multiple endocrine axes in these mice. We find no evidence of reduced intrauterine growth, food intake, or physical activity, but there is evidence for increased energy expenditure in mutants. In addition, despite changes in pituitary hormone expression, hypothalamic-pituitary axes appear to be functional. Therefore, SOX21 variants may be a cause of non-endocrine short stature in humans. PMID:27616671

Systematic discovery of novel ciliary genes through functional genomics in the zebrafish

PubMed Central

Choksi, Semil P.; Babu, Deepak; Lau, Doreen; Yu, Xianwen; Roy, Sudipto

2014-01-01

Cilia are microtubule-based hair-like organelles that play many important roles in development and physiology, and are implicated in a rapidly expanding spectrum of human diseases, collectively termed ciliopathies. Primary ciliary dyskinesia (PCD), one of the most prevalent of ciliopathies, arises from abnormalities in the differentiation or motility of the motile cilia. Despite their biomedical importance, a methodical functional screen for ciliary genes has not been carried out in any vertebrate at the organismal level. We sought to systematically discover novel motile cilia genes by identifying the genes induced by Foxj1, a winged-helix transcription factor that has an evolutionarily conserved role as the master regulator of motile cilia biogenesis. Unexpectedly, we find that the majority of the Foxj1-induced genes have not been associated with cilia before. To characterize these novel putative ciliary genes, we subjected 50 randomly selected candidates to a systematic functional phenotypic screen in zebrafish embryos. Remarkably, we find that over 60% are required for ciliary differentiation or function, whereas 30% of the proteins encoded by these genes localize to motile cilia. We also show that these genes regulate the proper differentiation and beating of motile cilia. This collection of Foxj1-induced genes will be invaluable for furthering our understanding of ciliary biology, and in the identification of new mutations underlying ciliary disorders in humans. PMID:25139857

Aging and Immunopathology in Primary Sjögren's Syndrome.

PubMed

Bouma, Hjalmar R; Bootsma, Hendrika; van Nimwegen, Jolien F; Haacke, Erlin A; Spijkervet, Fred K; Vissink, Arjan; Kroese, Frans G M

2015-01-01

Sicca complaints (sensation of dry mouth and/or eyes) are present in about a quarter of the individuals above the age of 65 years old and are mainly due to medication. However, physiological changes that occur during aging might also lead to a diminished glandular function. These age-related changes are, at least in part, to be the consequence of decreased androgen levels. In addition to these physiological effects that occur during normal aging, sicca complaints can also be caused by Sjögren's syndrome (SS): a systemic auto-inflammatory disorder mainly affecting exocrine glands. Genetic factors, lowered levels of gonadal hormones and (viral) infections appear to contribute to the etiology of the syndrome. The incidence of SS is higher among aged individuals, which might be due to earlier diagnosis, as the onset of SS in an individual with age-related exocrine gland dysfunction lowers the threshold for sicca complaints. On the other hand, physiological aging might be considered as a risk factor for development of SS, resulting in a faster development of the syndrome. Differentiating physiological sicca complaints from SS in the elderly can be challenging, since apparently healthy individuals might present with auto-antibodies and lymphocytic infiltrates in salivary glands might be present as well. The drop in the level of androgens and estrogens upon aging, immunosenescence and pro-inflammatory features of the aging immune system may all contribute to the etiology of pSS in the elderly. In this review, we describe the physiological effects of aging and the influence of SS on exocrine gland morphology and function.

A physiology-based model describing heterogeneity in glucose metabolism: the core of the Eindhoven Diabetes Education Simulator (E-DES).

PubMed

Maas, Anne H; Rozendaal, Yvonne J W; van Pul, Carola; Hilbers, Peter A J; Cottaar, Ward J; Haak, Harm R; van Riel, Natal A W

2015-03-01

Current diabetes education methods are costly, time-consuming, and do not actively engage the patient. Here, we describe the development and verification of the physiological model for healthy subjects that forms the basis of the Eindhoven Diabetes Education Simulator (E-DES). E-DES shall provide diabetes patients with an individualized virtual practice environment incorporating the main factors that influence glycemic control: food, exercise, and medication. The physiological model consists of 4 compartments for which the inflow and outflow of glucose and insulin are calculated using 6 nonlinear coupled differential equations and 14 parameters. These parameters are estimated on 12 sets of oral glucose tolerance test (OGTT) data (226 healthy subjects) obtained from literature. The resulting parameter set is verified on 8 separate literature OGTT data sets (229 subjects). The model is considered verified if 95% of the glucose data points lie within an acceptance range of ±20% of the corresponding model value. All glucose data points of the verification data sets lie within the predefined acceptance range. Physiological processes represented in the model include insulin resistance and β-cell function. Adjusting the corresponding parameters allows to describe heterogeneity in the data and shows the capabilities of this model for individualization. We have verified the physiological model of the E-DES for healthy subjects. Heterogeneity of the data has successfully been modeled by adjusting the 4 parameters describing insulin resistance and β-cell function. Our model will form the basis of a simulator providing individualized education on glucose control. © 2014 Diabetes Technology Society.

Oxygen and differentiation status modulate the effect of X-ray irradiation on physiology and mitochondrial proteome of human neuroblastoma cells.

PubMed

Džinić, Tamara; Hartwig, Sonja; Lehr, Stefan; Dencher, Norbert A

2016-12-01

Cytotoxic effects, including oxidative stress, of low linear energy transfer (LET)-ionizing radiation are often underestimated and studies of their mechanisms using cell culture models are widely conducted with cells cultivated at atmospheric oxygen that does not match its physiological levels in body tissues. Also, cell differentiation status plays a role in the outcome of experiments. We compared effects of 2 Gy X-ray irradiation on the physiology and mitochondrial proteome of nondifferentiated and human neuroblastoma (SH-SY5Y) cells treated with retinoic acid cultivated at 21% and 5% O 2 . Irradiation did not affect the amount of subunits of OxPhos complexes and other non-OxPhos mitochondrial proteins, except for heat shock protein 70, which was increased depending on oxygen level and differentiation status. These two factors were proven to modulate mitochondrial membrane potential and the bioenergetic status of cells. We suggest, moreover, that oxygen plays a role in the differentiation of human SH-SY5Y cells.

Teaching cardiovascular physiology with equivalent electronic circuits in a practically oriented teaching module.

PubMed

Ribaric, Samo; Kordas, Marjan

2011-06-01

Here, we report on a new tool for teaching cardiovascular physiology and pathophysiology that promotes qualitative as well as quantitative thinking about time-dependent physiological phenomena. Quantification of steady and presteady-state (transient) cardiovascular phenomena is traditionally done by differential equations, but this is time consuming and unsuitable for most undergraduate medical students. As a result, quantitative thinking about time-dependent physiological phenomena is often not extensively dealt with in an undergraduate physiological course. However, basic concepts of steady and presteady state can be explained with relative simplicity, without the introduction of differential equation, with equivalent electronic circuits (EECs). We introduced undergraduate medical students to the concept of simulating cardiovascular phenomena with EECs. EEC simulations facilitate the understanding of simple or complex time-dependent cardiovascular physiological phenomena by stressing the analogies between EECs and physiological processes. Student perceptions on using EEC to simulate, study, and understand cardiovascular phenomena were documented over a 9-yr period, and the impact of the course on the students' knowledge of selected basic facts and concepts in cardiovascular physiology was evaluated over a 3-yr period. We conclude that EECs are a valuable tool for teaching cardiovascular physiology concepts and that EECs promote active learning.

MAPK pathway control of stem cell proliferation and differentiation in the embryonic pituitary provides insights into the pathogenesis of papillary craniopharyngioma.

PubMed

Haston, Scott; Pozzi, Sara; Carreno, Gabriela; Manshaei, Saba; Panousopoulos, Leonidas; Gonzalez-Meljem, Jose Mario; Apps, John R; Virasami, Alex; Thavaraj, Selvam; Gutteridge, Alice; Forshew, Tim; Marais, Richard; Brandner, Sebastian; Jacques, Thomas S; Andoniadou, Cynthia L; Martinez-Barbera, Juan Pedro

2017-06-15

Despite the importance of the RAS-RAF-MAPK pathway in normal physiology and disease of numerous organs, its role during pituitary development and tumourigenesis remains largely unknown. Here, we show that the over-activation of the MAPK pathway, through conditional expression of the gain-of-function alleles BrafV600E and KrasG12D in the developing mouse pituitary, results in severe hyperplasia and abnormal morphogenesis of the gland by the end of gestation. Cell-lineage commitment and terminal differentiation are disrupted, leading to a significant reduction in numbers of most of the hormone-producing cells before birth, with the exception of corticotrophs. Of note, Sox2 + stem cells and clonogenic potential are drastically increased in the mutant pituitaries. Finally, we reveal that papillary craniopharyngioma (PCP), a benign human pituitary tumour harbouring BRAF p.V600E also contains Sox2 + cells with sustained proliferative capacity and disrupted pituitary differentiation. Together, our data demonstrate a crucial function of the MAPK pathway in controlling the balance between proliferation and differentiation of Sox2 + cells and suggest that persistent proliferative capacity of Sox2 + cells may underlie the pathogenesis of PCP. © 2017. Published by The Company of Biologists Ltd.

Metabolic Maturation during Muscle Stem Cell Differentiation Is Achieved by miR-1/133a-Mediated Inhibition of the Dlk1-Dio3 Mega Gene Cluster.

PubMed

Wüst, Stas; Dröse, Stefan; Heidler, Juliana; Wittig, Ilka; Klockner, Ina; Franko, Andras; Bonke, Erik; Günther, Stefan; Gärtner, Ulrich; Boettger, Thomas; Braun, Thomas

2018-05-01

Muscle stem cells undergo a dramatic metabolic switch to oxidative phosphorylation during differentiation, which is achieved by massively increased mitochondrial activity. Since expression of the muscle-specific miR-1/133a gene cluster correlates with increased mitochondrial activity during muscle stem cell (MuSC) differentiation, we examined the potential role of miR-1/133a in metabolic maturation of skeletal muscles in mice. We found that miR-1/133a downregulate Mef2A in differentiated myocytes, thereby suppressing the Dlk1-Dio3 gene cluster, which encodes multiple microRNAs inhibiting expression of mitochondrial genes. Loss of miR-1/133a in skeletal muscles or increased Mef2A expression causes continuous high-level expression of the Dlk1-Dio3 gene cluster, compromising mitochondrial function. Failure to terminate the stem cell-like metabolic program characterized by high-level Dlk1-Dio3 gene cluster expression initiates profound changes in muscle physiology, essentially abrogating endurance running. Our results suggest a major role of miR-1/133a in metabolic maturation of skeletal muscles but exclude major functions in muscle development and MuSC maintenance. Copyright © 2018 Elsevier Inc. All rights reserved.

Characterization of Apoptosis Signaling Cascades During the Differentiation Process of Human Neural ReNcell VM Progenitor Cells In Vitro.

PubMed

Jaeger, Alexandra; Fröhlich, Michael; Klum, Susanne; Lantow, Margareta; Viergutz, Torsten; Weiss, Dieter G; Kriehuber, Ralf

2015-11-01

Apoptosis is an essential physiological process accompanying the development of the central nervous system and human neurogenesis. However, the time scale and the underlying molecular mechanisms are yet poorly understood. Due to this fact, we investigated the functionality and general inducibility of apoptosis in the human neural ReNcell VM progenitor cell line during differentiation and also after exposure to staurosporine (STS) and ultraviolet B (UVB) irradiation. Transmission light microscopy, flow cytometry, and Western-/Immunoblot analysis were performed to compare proliferating and differentiating, in addition to STS- and UVB-treated cells. In particular, from 24 to 72 h post-initiation of differentiation, G0/G1 cell cycle arrest, increased loss of apoptotic cells, activation of pro-apoptotic BAX, Caspase-3, and cleavage of its substrate PARP were observed during cell differentiation and, to a higher extent, after treatment with STS and UVB. We conclude that redundant or defective cells are eliminated by apoptosis, while otherwise fully differentiated cells were less responsive to apoptosis induction by STS than proliferating cells, likely as a result of reduced APAF-1 expression, and increased levels of BCL-2. These data provide the evidence that apoptotic mechanisms in the neural ReNcell VM progenitor cell line are not only functional, but also inducible by external stimuli like growth factor withdrawal or treatment with STS and UVB, which marks this cell line as a suitable model to investigate apoptosis signaling pathways in respect to the differentiation processes of human neural progenitor cells in vitro.

Application of a Parallelizable Perfusion Bioreactor for Physiologic 3D Cell Culture.

PubMed

Egger, Dominik; Spitz, Sarah; Fischer, Monica; Handschuh, Stephan; Glösmann, Martin; Friemert, Benedikt; Egerbacher, Monika; Kasper, Cornelia

2017-01-01

It is crucial but challenging to keep physiologic conditions during the cultivation of 3D cell scaffold constructs for the optimization of 3D cell culture processes. Therefore, we demonstrate the benefits of a recently developed miniaturized perfusion bioreactor together with a specialized incubator system that allows for the cultivation of multiple samples while screening different conditions. Hence, a decellularized bone matrix was tested towards its suitability for 3D osteogenic differentiation under flow perfusion conditions. Subsequently, physiologic shear stress and hydrostatic pressure (HP) conditions were optimized for osteogenic differentiation of human mesenchymal stem cells (MSCs). X-ray computed microtomography and scanning electron microscopy (SEM) revealed a closed cell layer covering the entire matrix. Osteogenic differentiation assessed by alkaline phosphatase activity and SEM was found to be increased in all dynamic conditions. Furthermore, screening of different fluid shear stress (FSS) conditions revealed 1.5 mL/min (equivalent to ∼10 mPa shear stress) to be optimal. However, no distinct effect of HP compared to flow perfusion without HP on osteogenic differentiation was observed. Notably, throughout all experiments, cells cultivated under FSS or HP conditions displayed increased osteogenic differentiation, which underlines the importance of physiologic conditions. In conclusion, the bioreactor system was used for biomaterial testing and to develop and optimize a 3D cell culture process for the osteogenic differentiation of MSCs. Due to its versatility and higher throughput efficiency, we hypothesize that this bioreactor/incubator system will advance the development and optimization of a variety of 3D cell culture processes. © 2017 S. Karger AG, Basel.

Wavelet analysis of polarization maps of polycrystalline biological fluids networks

NASA Astrophysics Data System (ADS)

Ushenko, Y. A.

2011-12-01

The optical model of human joints synovial fluid is proposed. The statistic (statistic moments), correlation (autocorrelation function) and self-similar (Log-Log dependencies of power spectrum) structure of polarization two-dimensional distributions (polarization maps) of synovial fluid has been analyzed. It has been shown that differentiation of polarization maps of joint synovial fluid with different physiological state samples is expected of scale-discriminative analysis. To mark out of small-scale domain structure of synovial fluid polarization maps, the wavelet analysis has been used. The set of parameters, which characterize statistic, correlation and self-similar structure of wavelet coefficients' distributions of different scales of polarization domains for diagnostics and differentiation of polycrystalline network transformation connected with the pathological processes, has been determined.

Winter wheat: A model for the simulation of growth and yield in winter wheat

NASA Technical Reports Server (NTRS)

Baker, D. N.; Smika, D. E.; Black, A. L.; Willis, W. O.; Bauer, A. (Principal Investigator)

1981-01-01

The basic ideas and constructs for a general physical/physiological process level winter wheat simulation model are documented. It is a materials balance model which calculates daily increments of photosynthate production and respiratory losses in the crop canopy. The partitioning of the resulting dry matter to the active growing tissues in the plant each day, transpiration and the uptake of nitrogen from the soil profile are simulated. It incorporates the RHIZOS model which simulates, in two dimensions, the movement of water, roots, and soluble nutrients through the soil profile. It records the time of initiation of each of the plant organs. These phenological events are calculated from temperature functions with delays resulting from physiological stress. Stress is defined mathematically as an imbalance in the metabolite supply; demand ratio. Physiological stress is also the basis for the calculation of rates of tiller and floret abortion. Thus, tillering and head differentiation are modeled as the resulants of the two processes, morphogenesis and abortion, which may be occurring simulaneously.

Preschoolers' genetic, physiological, and behavioral sensitivity factors moderate links between parenting stress and child internalizing, externalizing, and sleep problems.

PubMed

Davis, Molly; Thomassin, Kristel; Bilms, Joanie; Suveg, Cynthia; Shaffer, Anne; Beach, Steven R H

2017-05-01

This study examined three potential moderators of the relations between maternal parenting stress and preschoolers' adjustment problems: a genetic polymorphism-the short allele of the serotonin transporter (5-HTTLPR, ss/sl allele) gene, a physiological indicator-children's baseline respiratory sinus arrhythmia (RSA), and a behavioral indicator-mothers' reports of children's negative emotionality. A total of 108 mothers (M age  = 30.68 years, SD age  = 6.06) reported on their parenting stress as well as their preschoolers' (M age  = 3.50 years, SD age  = 0.51, 61% boys) negative emotionality and internalizing, externalizing, and sleep problems. Results indicated that the genetic sensitivity variable functioned according to a differential susceptibility model; however, the results involving physiological and behavioral sensitivity factors were most consistent with a diathesis-stress framework. Implications for prevention and intervention efforts to counter the effects of parenting stress are discussed. © 2017 Wiley Periodicals, Inc.

Two-dimensional proteomic analysis of gonads of air-breathing catfish, Clarias batrachus after the exposure of endosulfan and malathion.

PubMed

Laldinsangi, C; Vijayaprasadarao, K; Rajakumar, A; Murugananthkumar, R; Prathibha, Y; Sudhakumari, C C; Mamta, S K; Dutta-Gupta, A; Senthilkumaran, B

2014-05-01

Endocrine disrupting chemicals have raised public concern, since their effects have been found to interfere with the physiological systems of various organisms, especially during critical stage of development and reproduction. Endosulfan and malathion, pesticides widely used for agricultural purposes, have been known to disrupt physiological functions in aquatic organisms. The current work analyzes the effects of endosulfan (2.5 parts per billion [ppb]) and malathion (10 ppb) on the reproductive physiology of catfish (Clarias batrachus) by evaluating protein expression profiles after 21 days of exposure. The proteomic profile of testis and ovary after exposure to endosulfan showed downregulation of proteins such as ubiquitin and Esco2, and upregulation in melanocortin-receptor-2 respectively. Malathion exposed ovary showed upregulated prolactin levels. Identification of proteins differentially expressed in gonads due to the exposure to these pesticides may serve as crucial indications to denote their disruptive effects at the level of proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

Distinct Physiological Maturation of Parvalbumin-Positive Neuron Subtypes in Mouse Prefrontal Cortex.

PubMed

Miyamae, Takeaki; Chen, Kehui; Lewis, David A; Gonzalez-Burgos, Guillermo

2017-05-10

Parvalbumin-positive (PV + ) neurons control the timing of pyramidal cell output in cortical neuron networks. In the prefrontal cortex (PFC), PV + neuron activity is involved in cognitive function, suggesting that PV + neuron maturation is critical for cognitive development. The two major PV + neuron subtypes found in the PFC, chandelier cells (ChCs) and basket cells (BCs), are thought to play different roles in cortical circuits, but the trajectories of their physiological maturation have not been compared. Using two separate mouse lines, we found that in the mature PFC, both ChCs and BCs are abundant in superficial layer 2, but only BCs are present in deeper laminar locations. This distinctive laminar distribution was observed by postnatal day 12 (P12), when we first identified ChCs by the presence of axon cartridges. Electrophysiology analysis of excitatory synapse development, starting at P12, showed that excitatory drive remains low throughout development in ChCs, but increases rapidly before puberty in BCs, with an earlier time course in deeper-layer BCs. Consistent with a role of excitatory synaptic drive in the maturation of PV + neuron firing properties, the fast-spiking phenotype showed different maturation trajectories between ChCs and BCs, and between superficial versus deep-layer BCs. ChC and BC maturation was nearly completed, via different trajectories, before the onset of puberty. These findings suggest that ChC and BC maturation may contribute differentially to the emergence of cognitive function, primarily during prepubertal development. SIGNIFICANCE STATEMENT Parvalbumin-positive (PV + ) neurons tightly control pyramidal cell output. Thus PV + neuron maturation in the prefrontal cortex (PFC) is crucial for cognitive development. However, the relative physiological maturation of the two major subtypes of PV + neurons, chandelier cells (ChCs) and basket cells (BCs), has not been determined. We assessed the maturation of ChCs and BCs in different layers of the mouse PFC, and found that, from early postnatal age, ChCs and BCs differ in laminar location. Excitatory synapses and fast-spiking properties matured before the onset of puberty in both cell types, but following cell type-specific developmental trajectories. Hence, the physiological maturation of ChCs and BCs may contribute to the emergence of cognitive function differentially, and predominantly during prepubertal development. Copyright © 2017 the authors 0270-6474/17/374883-20$15.00/0.

Eye Development in Sepia officinalis Embryo: What the Uncommon Gene Expression Profiles Tell Us about Eye Evolution.

PubMed

Imarazene, Boudjema; Andouche, Aude; Bassaglia, Yann; Lopez, Pascal-Jean; Bonnaud-Ponticelli, Laure

2017-01-01

In metazoans, there is a remarkable diversity of photosensitive structures; their shapes, physiology, optical properties, and development are different. To approach the evolution of photosensitive structures and visual function, cephalopods are particularly interesting organisms due to their most highly centralized nervous system and their camerular eyes which constitute a convergence with those of vertebrates. The eye morphogenesis in numerous metazoans is controlled mainly by a conserved Retinal Determination Gene Network (RDGN) including pax, six, eya , and dac playing also key developmental roles in non-retinal structures and tissues of vertebrates and Drosophila . Here we have identified and explored the role of Sof-dac, Sof-six1/2, Sof-eya in eye morphogenesis, and nervous structures controlling the visual function in Sepia officinalis . We compare that with the already shown expressions in eye development of Sof-otx and Sof-pax genes. Rhodopsin is the pigment responsible for light sensitivity in metazoan, which correlate to correlate visual function and eye development. We studied Sof-rhodopsin expression during retina differentiation. By in situ hybridization, we show that (1) all of the RDGN genes, including Sof-pax6 , are expressed in the eye area during the early developmental stages but they are not expressed in the retina, unlike Sof-otx , which could have a role in retina differentiation; (2) Sof-rhodopsin is expressed in the retina just before vision gets functional, from stage 23 to hatching. Our results evidence a role of Sof-six1/2, Sof-eya , and Sof-dac in eye development. However, the gene network involved in the retinal photoreceptor differentiation remains to be determined. Moreover, for the first time, Sof-rhodopsin expression is shown in the embryonic retina of cuttlefish suggesting the evolutionary conservation of the role of rhodopsin in visual phototransduction within metazoans. These findings are correlated with the physiological and behavioral observations suggesting that S. officinalis is able to react to light stimuli from stage 25 of organogenesis on, as soon as the first retinal pigments appear.

Eye Development in Sepia officinalis Embryo: What the Uncommon Gene Expression Profiles Tell Us about Eye Evolution

PubMed Central

Imarazene, Boudjema; Andouche, Aude; Bassaglia, Yann; Lopez, Pascal-Jean; Bonnaud-Ponticelli, Laure

2017-01-01

In metazoans, there is a remarkable diversity of photosensitive structures; their shapes, physiology, optical properties, and development are different. To approach the evolution of photosensitive structures and visual function, cephalopods are particularly interesting organisms due to their most highly centralized nervous system and their camerular eyes which constitute a convergence with those of vertebrates. The eye morphogenesis in numerous metazoans is controlled mainly by a conserved Retinal Determination Gene Network (RDGN) including pax, six, eya, and dac playing also key developmental roles in non-retinal structures and tissues of vertebrates and Drosophila. Here we have identified and explored the role of Sof-dac, Sof-six1/2, Sof-eya in eye morphogenesis, and nervous structures controlling the visual function in Sepia officinalis. We compare that with the already shown expressions in eye development of Sof-otx and Sof-pax genes. Rhodopsin is the pigment responsible for light sensitivity in metazoan, which correlate to correlate visual function and eye development. We studied Sof-rhodopsin expression during retina differentiation. By in situ hybridization, we show that (1) all of the RDGN genes, including Sof-pax6, are expressed in the eye area during the early developmental stages but they are not expressed in the retina, unlike Sof-otx, which could have a role in retina differentiation; (2) Sof-rhodopsin is expressed in the retina just before vision gets functional, from stage 23 to hatching. Our results evidence a role of Sof-six1/2, Sof-eya, and Sof-dac in eye development. However, the gene network involved in the retinal photoreceptor differentiation remains to be determined. Moreover, for the first time, Sof-rhodopsin expression is shown in the embryonic retina of cuttlefish suggesting the evolutionary conservation of the role of rhodopsin in visual phototransduction within metazoans. These findings are correlated with the physiological and behavioral observations suggesting that S. officinalis is able to react to light stimuli from stage 25 of organogenesis on, as soon as the first retinal pigments appear. PMID:28883798

Angiocrine functions of organ-specific endothelial cells

PubMed Central

Rafii, Shahin; Butler, Jason M; Ding, Bi-Sen

2016-01-01

Preface Endothelial cells lining blood vessel capillaries are not just passive conduits for delivering blood. Tissue-specific endothelium establish specialized vascular niches that deploy specific sets of growth factors, known as angiocrine factors, which actively participate in inducing, specifying, patterning, and guiding organ regeneration and maintaining homeostasis and metabolism. Angiocrine factors upregulated in response to injury orchestrates self-renewal and differentiation of tissue-specific repopulating resident stem and progenitor cells into functional organs. Uncovering the precise mechanisms whereby physiological-levels of angiocrine factors are spatially and temporally produced, and distributed by organotypic endothelium to repopulating cells, will lay the foundation for driving organ repair without scarring. PMID:26791722

[Osteopontin and male reproduction].

PubMed

Liu, Qian; Xie, Qing-Zhen

2012-05-01

Osteopontin (OPN) is an extracellular matrix protein with multifunctions, expressed in various tissues and body fluids, involved in various physiological and pathological processes. It is also detected in the reproductive tract of both males and females, and participates in the implantation, development and differentiation of embryos. Recent studies have indicated that OPN is closely related with male fertility and may affect sperm quality and fertilization. An insight into the functions of OPN may help to explain the mechanisms of male infertility and improve the success rate of assisted reproductive technology.

Reverse genetics: Its origins and prospects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berg, P.

1991-04-01

The nucleotide sequence of a gene and its flanking segments alone will not tell us how its expression is regulated during development and differentiation, or in response to environmental changes. To comprehend the physiological significance of the molecular details requires biological analysis. Recombinant DNA techniques provide a powerful experimental approach. A strategy termed reverse genetics' utilizes the analysis of the activities of mutant and normal genes and experimentally constructed mutants to explore the relationship between gene structure and function thereby helping elucidate the relationship between genotype and phenotype.

Immune physiology in tissue regeneration and aging, tumor growth, and regenerative medicine.

PubMed

Bukovsky, Antonin; Caudle, Michael R; Carson, Ray J; Gaytán, Francisco; Huleihel, Mahmoud; Kruse, Andrea; Schatten, Heide; Telleria, Carlos M

2009-02-13

The immune system plays an important role in immunity (immune surveillance), but also in the regulation of tissue homeostasis (immune physiology). Lessons from the female reproductive tract indicate that immune system related cells, such as intraepithelial T cells and monocyte-derived cells (MDC) in stratified epithelium, interact amongst themselves and degenerate whereas epithelial cells proliferate and differentiate. In adult ovaries, MDC and T cells are present during oocyte renewal from ovarian stem cells. Activated MDC are also associated with follicular development and atresia, and corpus luteum differentiation. Corpus luteum demise resembles rejection of a graft since it is attended by a massive influx of MDC and T cells resulting in parenchymal and vascular regression. Vascular pericytes play important roles in immune physiology, and their activities (including secretion of the Thy-1 differentiation protein) can be regulated by vascular autonomic innervation. In tumors, MDC regulate proliferation of neoplastic cells and angiogenesis. Tumor infiltrating T cells die among malignant cells. Alterations of immune physiology can result in pathology, such as autoimmune, metabolic, and degenerative diseases, but also in infertility and intrauterine growth retardation, fetal morbidity and mortality. Animal experiments indicate that modification of tissue differentiation (retardation or acceleration) during immune adaptation can cause malfunction (persistent immaturity or premature aging) of such tissue during adulthood. Thus successful stem cell therapy will depend on immune physiology in targeted tissues. From this point of view, regenerative medicine is more likely to be successful in acute rather than chronic tissue disorders.

Immune physiology in tissue regeneration and aging, tumor growth, and regenerative medicine

PubMed Central

Bukovsky, Antonin; Caudle, Michael R.; Carson, Ray J.; Gaytán, Francisco; Huleihel, Mahmoud; Kruse, Andrea; Schatten, Heide; Telleria, Carlos M.

2009-01-01

The immune system plays an important role in immunity (immune surveillance), but also in the regulation of tissue homeostasis (immune physiology). Lessons from the female reproductive tract indicate that immune system related cells, such as intraepithelial T cells and monocyte-derived cells (MDC) in stratified epithelium, interact amongst themselves and degenerate whereas epithelial cells proliferate and differentiate. In adult ovaries, MDC and T cells are present during oocyte renewal from ovarian stem cells. Activated MDC are also associated with follicular development and atresia, and corpus luteum differentiation. Corpus luteum demise resembles rejection of a graft since it is attended by a massive influx of MDC and T cells resulting in parenchymal and vascular regression. Vascular pericytes play important roles in immune physiology, and their activities (including secretion of the Thy-1 differentiation protein) can be regulated by vascular autonomic innervation. In tumors, MDC regulate proliferation of neoplastic cells and angiogenesis. Tumor infiltrating T cells die among malignant cells. Alterations of immune physiology can result in pathology, such as autoimmune, metabolic, and degenerative diseases, but also in infertility and intrauterine growth retardation, fetal morbidity and mortality. Animal experiments indicate that modification of tissue differentiation (retardation or acceleration) during immune adaptation can cause malfunction (persistent immaturity or premature aging) of such tissue during adulthood. Thus successful stem cell therapy will depend on immune physiology in targeted tissues. From this point of view, regenerative medicine is more likely to be successful in acute rather than chronic tissue disorders. PMID:20195382

Platform for combined analysis of functional and biomolecular phenotypes of the same cell.

PubMed

Kelbauskas, L; Ashili, S; Zeng, J; Rezaie, A; Lee, K; Derkach, D; Ueberroth, B; Gao, W; Paulson, T; Wang, H; Tian, Y; Smith, D; Reid, B; Meldrum, Deirdre R

2017-03-16

Functional and molecular cell-to-cell variability is pivotal at the cellular, tissue and whole-organism levels. Yet, the ultimate goal of directly correlating the function of the individual cell with its biomolecular profile remains elusive. We present a platform for integrated analysis of functional and transcriptional phenotypes in the same single cells. We investigated changes in the cellular respiration and gene expression diversity resulting from adaptation to repeated episodes of acute hypoxia in a premalignant progression model. We find differential, progression stage-specific alterations in phenotypic heterogeneity and identify cells with aberrant phenotypes. To our knowledge, this study is the first demonstration of an integrated approach to elucidate how heterogeneity at the transcriptional level manifests in the physiologic profile of individual cells in the context of disease progression.

Resting-state functional connectivity differentiates anxious apprehension and anxious arousal.

PubMed

Burdwood, Erin N; Infantolino, Zachary P; Crocker, Laura D; Spielberg, Jeffrey M; Banich, Marie T; Miller, Gregory A; Heller, Wendy

2016-10-01

Brain regions in the default mode network (DMN) display greater functional connectivity at rest or during self-referential processing than during goal-directed tasks. The present study assessed resting-state connectivity as a function of anxious apprehension and anxious arousal, independent of depressive symptoms, in order to understand how these dimensions disrupt cognition. Whole-brain, seed-based analyses indicated differences between anxious apprehension and anxious arousal in DMN functional connectivity. Lower connectivity associated with higher anxious apprehension suggests decreased adaptive, inner-focused thought processes, whereas higher connectivity at higher levels of anxious arousal may reflect elevated monitoring of physiological responses to threat. These findings further the conceptualization of anxious apprehension and anxious arousal as distinct psychological dimensions with distinct neural instantiations. © 2016 Society for Psychophysiological Research.

Gold nanoparticles as physiological markers of urine internalization into urothelial cells in vivo

PubMed Central

Hudoklin, Samo; Zupančič, Daša; Makovec, Darko; Kreft, Mateja Erdani; Romih, Rok

2013-01-01

Background Urothelial bladder is the reservoir of urine and the urothelium minimizes the exchange of urine constituents with this tissue. Our aim was to test 1.9 nm biocompatible gold nanoparticles as a novel marker of internalization into the urothelial cells under physiological conditions in vivo. Methods We compared normal and neoplastic mice urothelium. Neoplastic lesions were induced by 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in drinking water for 10 weeks. Nanoparticles, intravenously injected into normal and BBN-treated mice, were filtered through the kidneys and became constituents of the urine within 90 minutes after injection. Results Gold nanoparticles were densely accumulated in the urine, while their internalization into urothelial cells depended on the cell differentiation stage. In the terminally differentiated superficial urothelial cells of normal animals, nanoparticles were occasionally found in the endosomes, but not in the fusiform vesicles. Regions of exfoliated cells were occasionally found in the normal urothelium. Superficial urothelial cells located next to exfoliated regions contained gold nanoparticles in the endosomes and in the cytosol beneath the apical plasma membrane. The urothelium of BBN-treated animals developed fat hyperplasia with moderate dysplasia. The superficial cells of BBN-treated animals were partially differentiated as demonstrated by the lack of fusiform vesicles. These cells contained the gold nanoparticles distributed in the endosomes and throughout their cytosol. Conclusion Gold nanoparticles are a valuable marker to study urine internalization into urothelial cells in vivo. Moreover, they can be used as a sensitive marker of differentiation and functionality of urothelial cells. PMID:24143099

The physiological determinants of drug-induced lysosomal stress resistance

PubMed Central

Woldemichael, Tehetina; Rosania, Gus R.

2017-01-01

Many weakly basic, lipophilic drugs accumulate in lysosomes and exert complex, pleiotropic effects on organelle structure and function. Thus, modeling how perturbations of lysosomal physiology affect the maintenance of lysosomal ion homeostasis is necessary to elucidate the key factors which determine the toxicological effects of lysosomotropic agents, in a cell-type dependent manner. Accordingly, a physiologically-based mathematical modeling and simulation approach was used to explore the dynamic, multi-parameter phenomenon of lysosomal stress. With this approach, parameters that are either directly involved in lysosomal ion transportation or lysosomal morphology were transiently altered to investigate their downstream effects on lysosomal physiology reflected by the changes they induce in lysosomal pH, chloride, and membrane potential. In addition, combinations of parameters were simultaneously altered to assess which parameter was most critical for recovery of normal lysosomal physiology. Lastly, to explore the relationship between organelle morphology and induced stress, we investigated the effects of parameters controlling organelle geometry on the restoration of normal lysosomal physiology following a transient perturbation. Collectively, our results indicate a key, interdependent role of V-ATPase number and membrane proton permeability in lysosomal stress tolerance. This suggests that the cell-type dependent regulation of V-ATPase subunit expression and turnover, together with the proton permeability properties of the lysosomal membrane, is critical to understand the differential sensitivity or resistance of different cell types to the toxic effects of lysosomotropic drugs. PMID:29117253

State-dependent physiological maintenance in a long-lived ectotherm, the painted turtle (Chrysemys picta).

PubMed

Schwanz, Lisa; Warner, Daniel A; McGaugh, Suzanne; Di Terlizzi, Roberta; Bronikowski, Anne

2011-01-01

Energy allocation among somatic maintenance, reproduction and growth varies not only among species, but among individuals according to states such as age, sex and season. Little research has been conducted on the somatic (physiological) maintenance of long-lived organisms, particularly ectotherms such as reptiles. In this study, we examined sex differences and age- and season-related variation in immune function and DNA repair efficiency in a long-lived reptile, the painted turtle (Chrysemys picta). Immune components tended to be depressed during hibernation, in winter, compared with autumn or spring. Increased heterophil count during hibernation provided the only support for winter immunoenhancement. In juvenile and adult turtles, we found little evidence for senescence in physiological maintenance, consistent with predictions for long-lived organisms. Among immune components, swelling in response to phytohemagglutinin (PHA) and control injection increased with age, whereas basophil count decreased with age. Hatchling turtles had reduced basophil counts and natural antibodies, indicative of an immature immune system, but demonstrated higher DNA repair efficiency than older turtles. Reproductively mature turtles had reduced lymphocytes compared with juvenile turtles in the spring, presumably driven by a trade-off between maintenance and reproduction. Sex had little influence on physiological maintenance. These results suggest that components of physiological maintenance are modulated differentially according to individual state and highlight the need for more research on the multiple components of physiological maintenance in animals of variable states.

Expression pattern and signalling pathways in neutrophil like HL-60 cells after treatment with estrogen receptor selective ligands.

PubMed

Blesson, Chellakkan Selvanesan; Sahlin, Lena

2012-09-25

Estrogens play a role in the regulation of genes associated with inflammation and immunity in neutrophils. Estrogen signalling is mediated by estrogen receptor (ER)α, ERβ, and G-protein-coupled estrogen receptor-1 (GPER). The mechanisms by which estrogen regulate genes in neutrophils are poorly understood. Our aim was to identify the presence of ERs and to characterize estrogen responsive genes in terminally differentiated neutrophil like HL-60 (nHL-60) cells using estradiol and selective ER agonists. ERs were identified by Western blotting and immunocytochemistry. Microarray technique was used to screen for differentially expressed genes and the selected genes were verified by quantitative PCR. We show the presence of functional ERα, ERβ and GPER. Microarray analysis showed the presence of genes that are uniquely regulated by a single ligand and also genes that are regulated by multiple ligands. We conclude that ERs are functionally active in nHL-60 cells regulating genes involved in key physiological functions. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

miRNA expression and function in thyroid carcinomas: a comparative and critical analysis and a model for other cancers.

PubMed

Saiselet, Manuel; Pita, Jaime M; Augenlicht, Alice; Dom, Geneviève; Tarabichi, Maxime; Fimereli, Danai; Dumont, Jacques E; Detours, Vincent; Maenhaut, Carine

2016-08-09

As in many cancer types, miRNA expression profiles and functions have become an important field of research on non-medullary thyroid carcinomas, the most common endocrine cancers. This could lead to the establishment of new diagnostic tests and new cancer therapies. However, different studies showed important variations in their research strategies and results. In addition, the action of miRNAs is poorly considered as a whole because of the use of underlying dogmatic truncated concepts. These lead to discrepancies and limits rarely considered. Recently, this field has been enlarged by new miRNA functional and expression studies. Moreover, studies using next generation sequencing give a new view of general miRNA differential expression profiles of papillary thyroid carcinoma. We analyzed in detail this literature from both physiological and differential expression points of view. Based on explicit examples, we reviewed the progresses but also the discrepancies and limits trying to provide a critical approach of where this literature may lead. We also provide recommendations for future studies. The conclusions of this systematic analysis could be extended to other cancer types.

Overcoming the hurdles for a reproducible generation of human functionally mature reprogrammed neurons.

PubMed

Broccoli, Vania; Rubio, Alicia; Taverna, Stefano; Yekhlef, Latefa

2015-06-01

The advent of cell reprogramming technologies has widely disclosed the possibility to have direct access to human neurons for experimental and biomedical applications. Human pluripotent stem cells can be instructed in vitro to generate specific neuronal cell types as well as different glial cells. Moreover, new approaches of direct neuronal cell reprogramming can strongly accelerate the generation of different neuronal lineages. However, genetic heterogeneity, reprogramming fidelity, and time in culture of the starting cells can still significantly bias their differentiation efficiency and quality of the neuronal progenies. In addition, reprogrammed human neurons exhibit a very slow pace in gaining a full spectrum of functional properties including physiological levels of membrane excitability, sustained and prolonged action potential firing, mature synaptic currents and synaptic plasticity. This delay poses serious limitations for their significance as biological experimental model and screening platform. We will discuss new approaches of neuronal cell differentiation and reprogramming as well as methods to accelerate the maturation and functional activity of the converted human neurons. © 2015 by the Society for Experimental Biology and Medicine.

Differential Sensitivity of Target Genes to Translational Repression by miR-17~92

PubMed Central

Jin, Hyun Yong; Oda, Hiroyo; Chen, Pengda; Kang, Seung Goo; Valentine, Elizabeth; Liao, Lujian; Zhang, Yaoyang; Gonzalez-Martin, Alicia; Shepherd, Jovan; Head, Steven R.; Kim, Pyeung-Hyeun; Fu, Guo; Liu, Wen-Hsien; Han, Jiahuai

2017-01-01

MicroRNAs (miRNAs) are thought to exert their functions by modulating the expression of hundreds of target genes and each to a small degree, but it remains unclear how small changes in hundreds of target genes are translated into the specific function of a miRNA. Here, we conducted an integrated analysis of transcriptome and translatome of primary B cells from mutant mice expressing miR-17~92 at three different levels to address this issue. We found that target genes exhibit differential sensitivity to miRNA suppression and that only a small fraction of target genes are actually suppressed by a given concentration of miRNA under physiological conditions. Transgenic expression and deletion of the same miRNA gene regulate largely distinct sets of target genes. miR-17~92 controls target gene expression mainly through translational repression and 5’UTR plays an important role in regulating target gene sensitivity to miRNA suppression. These findings provide molecular insights into a model in which miRNAs exert their specific functions through a small number of key target genes. PMID:28241004

Structural and functional changes within the gut microbiota and susceptibility to Clostridium difficile infection

PubMed Central

Ross, Caná L.; Spinler, Jennifer K.; Savidge, Tor C.

2016-01-01

Alteration of the gut microbial community structure and function through antibiotic use increases susceptibility to colonization by Clostridium difficile and other enteric pathogens. However, the mechanisms that mediate colonization resistance remain elusive. As the leading definable cause of infectious diarrhea, toxigenic C. difficile represents a burden for patients and health care systems, underscoring the need for better diagnostics and treatment strategies. Next-generation sequence data has increased our understanding of how the gut microbiota is influenced by many factors including diet, disease, aging and drugs. However, a microbial-based biomarker differentiating C. difficile infection from antibiotic-associated diarrhea remains elusive. Metabolomics profiling, which is highly responsive to changes in physiological conditions, have shown promise in differentiating subtle disease phenotypes that exhibit a nearly identical microbiome community structure, suggesting metabolite-based biomarkers may be an ideal diagnostic for identifying patients with CDI. This review focuses on the current understanding of structural and functional changes to the gut microbiota during C. difficile infection obtained from studies assessing the microbiome and metabolome of samples from patients and murine models. PMID:27180006

TRP channels in the skin.

PubMed

Tóth, Balázs I; Oláh, Attila; Szöllősi, Attila Gábor; Bíró, Tamás

2014-05-01

Emerging evidence suggests that transient receptor potential (TRP) ion channels not only act as 'polymodal cellular sensors' on sensory neurons but are also functionally expressed by a multitude of non-neuronal cell types. This is especially true in the skin, one of the largest organs of the body, where they appear to be critically involved in regulating various cutaneous functions both under physiological and pathophysiological conditions. In this review, we focus on introducing the roles of several cutaneous TRP channels in the regulation of the skin barrier, skin cell proliferation and differentiation, and immune functions. Moreover, we also describe the putative involvement of several TRP channels in the development of certain skin diseases and identify future TRP channel-targeted therapeutic opportunities. © 2013 The British Pharmacological Society.

Time-dependent regulation of morphological changes and cartilage differentiation markers in the mouse pubic symphysis during pregnancy and postpartum recovery.

PubMed

Castelucci, Bianca Gazieri; Consonni, Sílvio Roberto; Rosa, Viviane Souza; Sensiate, Lucimara Aparecida; Delatti, Paula Cristina Rugno; Alvares, Lúcia Elvira; Joazeiro, Paulo Pinto

2018-01-01

Animal models commonly serve as a bridge between in vitro experiments and clinical applications; however, few physiological processes in adult animals are sufficient to serve as proof-of-concept models for cartilage regeneration. Intriguingly, some rodents, such as young adult mice, undergo physiological connective tissue modifications to birth canal elements such as the pubic symphysis during pregnancy; therefore, we investigated whether the differential expression of cartilage differentiation markers is associated with cartilaginous tissue morphological modifications during these changes. Our results showed that osteochondral progenitor cells expressing Runx2, Sox9, Col2a1 and Dcx at the non-pregnant pubic symphysis proliferated and differentiated throughout pregnancy, giving rise to a complex osteoligamentous junction that attached the interpubic ligament to the pubic bones until labour occurred. After delivery, the recovery of pubic symphysis cartilaginous tissues was improved by the time-dependent expression of these chondrocytic lineage markers at the osteoligamentous junction. This process potentially recapitulates embryologic chondrocytic differentiation to successfully recover hyaline cartilaginous pads at 10 days postpartum. Therefore, we propose that this physiological phenomenon represents a proof-of-concept model for investigating the mechanisms involved in cartilage restoration in adult animals.

Generation of functional hepatocyte-like cells from human pluripotent stem cells in a scalable suspension culture.

PubMed

Vosough, Massoud; Omidinia, Eskandar; Kadivar, Mehdi; Shokrgozar, Mohammad-Ali; Pournasr, Behshad; Aghdami, Nasser; Baharvand, Hossein

2013-10-15

Recent advances in human embryonic and induced pluripotent stem cell-based therapies in animal models of hepatic failure have led to an increased appreciation of the need to translate the proof-of-principle concepts into more practical and feasible protocols for scale up and manufacturing of functional hepatocytes. In this study, we describe a scalable stirred-suspension bioreactor culture of functional hepatocyte-like cells (HLCs) from the human pluripotent stem cells (hPSCs). To promote the initial differentiation of hPSCs in a carrier-free suspension stirred bioreactor into definitive endoderm, we used rapamycin for "priming" phase and activin A for induction. The cells were further differentiated into HLCs in the same system. HLCs were characterized and then purified based on their physiological function, the uptake of DiI-acetylated low-density lipoprotein (LDL) by flow cytometry without genetic manipulation or antibody labeling. The sorted cells were transplanted into the spleens of mice with acute liver injury from carbon tetrachloride. The differentiated HLCs had multiple features of primary hepatocytes, for example, the expression patterns of liver-specific marker genes, albumin secretion, urea production, collagen synthesis, indocyanin green and LDL uptake, glycogen storage, and inducible cytochrome P450 activity. They increased the survival rate, engrafted successfully into the liver, and continued to present hepatic function (i.e., albumin secretion after implantation). This amenable scaling up and outlined enrichment strategy provides a new platform for generating functional HLCs. This integrated approach may facilitate biomedical applications of the hPSC-derived hepatocytes.

Proteomic analysis of physiological function response to hot summer in liver from lactating dairy cows.

PubMed

Wang, Qiangjun; Zhao, Xiaowei; Zhang, Zijun; Zhao, Huiling; Huang, Dongwei; Cheng, Guanglong; Yang, Yongxin

2017-04-01

Lactation performance of dairy cattle is susceptible to heat stress. The liver is one of the most crucial organs affected by high temperature in dairy cows. However, the physiological adaption by the liver to hot summer conditions has not been well elucidated in lactating dairy cows. In the present study, proteomic analysis of the liver in dairy cows in spring and hot summer was performed using a label-free method. In total, 127 differentially expressed proteins were identified; most of the upregulated proteins were involved in protein metabolic processes and responses to stimuli, whereas most of the downregulated proteins were related to oxidation-reduction. Pathway analysis indicated that 3 upregulated heat stress proteins (HSP90α, HSP90β, and endoplasmin) were enriched in the NOD-like receptor signaling pathway, whereas several downregulated NADH dehydrogenase proteins were involved in the oxidative phosphorylation pathway. The protein-protein interaction network indicated that several upregulated HSPs (HSP90α, HSP90β, and GRP78) were involved in more interactions than other proteins and were thus considered as central hub nodes. Our findings provide novel insights into the physiological adaption of liver function in lactating dairy cows to natural high temperature. Copyright © 2017. Published by Elsevier Ltd.

Alternative functional in vitro models of human intestinal epithelia

PubMed Central

Kauffman, Amanda L.; Gyurdieva, Alexandra V.; Mabus, John R.; Ferguson, Chrissa; Yan, Zhengyin; Hornby, Pamela J.

2013-01-01

Physiologically relevant sources of absorptive intestinal epithelial cells are crucial for human drug transport studies. Human adenocarcinoma-derived intestinal cell lines, such as Caco-2, offer conveniences of easy culture maintenance and scalability, but do not fully recapitulate in vivo intestinal phenotypes. Additional sources of renewable physiologically relevant human intestinal cells would provide a much needed tool for drug discovery and intestinal physiology. We compared two alternative sources of human intestinal cells, commercially available primary human intestinal epithelial cells (hInEpCs) and induced pluripotent stem cell (iPSC)-derived intestinal cells to Caco-2, for use in in vitro transwell monolayer intestinal transport assays. To achieve this for iPSC-derived cells, intestinal organogenesis was adapted to transwell differentiation. Intestinal cells were assessed by marker expression through immunocytochemical and mRNA expression analyses, monolayer integrity through Transepithelial Electrical Resistance (TEER) measurements and molecule permeability, and functionality by taking advantage the well-characterized intestinal transport mechanisms. In most cases, marker expression for primary hInEpCs and iPSC-derived cells appeared to be as good as or better than Caco-2. Furthermore, transwell monolayers exhibited high TEER with low permeability. Primary hInEpCs showed molecule efflux indicative of P-glycoprotein (Pgp) transport. Primary hInEpCs and iPSC-derived cells also showed neonatal Fc receptor-dependent binding of immunoglobulin G variants. Primary hInEpCs and iPSC-derived intestinal cells exhibit expected marker expression and demonstrate basic functional monolayer formation, similar to or better than Caco-2. These cells could offer an alternative source of human intestinal cells for understanding normal intestinal epithelial physiology and drug transport. PMID:23847534

Alternative functional in vitro models of human intestinal epithelia.

PubMed

Kauffman, Amanda L; Gyurdieva, Alexandra V; Mabus, John R; Ferguson, Chrissa; Yan, Zhengyin; Hornby, Pamela J

2013-01-01

Physiologically relevant sources of absorptive intestinal epithelial cells are crucial for human drug transport studies. Human adenocarcinoma-derived intestinal cell lines, such as Caco-2, offer conveniences of easy culture maintenance and scalability, but do not fully recapitulate in vivo intestinal phenotypes. Additional sources of renewable physiologically relevant human intestinal cells would provide a much needed tool for drug discovery and intestinal physiology. We compared two alternative sources of human intestinal cells, commercially available primary human intestinal epithelial cells (hInEpCs) and induced pluripotent stem cell (iPSC)-derived intestinal cells to Caco-2, for use in in vitro transwell monolayer intestinal transport assays. To achieve this for iPSC-derived cells, intestinal organogenesis was adapted to transwell differentiation. Intestinal cells were assessed by marker expression through immunocytochemical and mRNA expression analyses, monolayer integrity through Transepithelial Electrical Resistance (TEER) measurements and molecule permeability, and functionality by taking advantage the well-characterized intestinal transport mechanisms. In most cases, marker expression for primary hInEpCs and iPSC-derived cells appeared to be as good as or better than Caco-2. Furthermore, transwell monolayers exhibited high TEER with low permeability. Primary hInEpCs showed molecule efflux indicative of P-glycoprotein (Pgp) transport. Primary hInEpCs and iPSC-derived cells also showed neonatal Fc receptor-dependent binding of immunoglobulin G variants. Primary hInEpCs and iPSC-derived intestinal cells exhibit expected marker expression and demonstrate basic functional monolayer formation, similar to or better than Caco-2. These cells could offer an alternative source of human intestinal cells for understanding normal intestinal epithelial physiology and drug transport.

A multidisciplinary approach to study the functional properties of neuron-like cell models constituting a living bio-hybrid system: SH-SY5Y cells adhering to PANI substrate

NASA Astrophysics Data System (ADS)

Caponi, S.; Mattana, S.; Ricci, M.; Sagini, K.; Juarez-Hernandez, L. J.; Jimenez-Garduño, A. M.; Cornella, N.; Pasquardini, L.; Urbanelli, L.; Sassi, P.; Morresi, A.; Emiliani, C.; Fioretto, D.; Dalla Serra, M.; Pederzolli, C.; Iannotta, S.; Macchi, P.; Musio, C.

2016-11-01

A living bio-hybrid system has been successfully implemented. It is constituted by neuroblastic cells, the SH-SY5Y human neuroblastoma cells, adhering to a poly-anyline (PANI) a semiconductor polymer with memristive properties. By a multidisciplinary approach, the biocompatibility of the substrate has been analyzed and the functionality of the adhering cells has been investigated. We found that the PANI films can support the cell adhesion. Moreover, the SH-SY5Y cells were successfully differentiated into neuron-like cells for in vitro applications demonstrating that PANI can also promote cell differentiation. In order to deeply characterize the modifications of the bio-functionality induced by the cell-substrate interaction, the functional properties of the cells have been characterized by electrophysiology and Raman spectroscopy. Our results confirm that the PANI films do not strongly affect the general properties of the cells, ensuring their viability without toxic effects on their physiology. Ascribed to the adhesion process, however, a slight increase of the markers of the cell suffering has been evidenced by Raman spectroscopy and accordingly the electrophysiology shows a reduction at positive stimulations in the cells excitability.

Perfusion Stirred-Tank Bioreactors for 3D Differentiation of Human Neural Stem Cells.

PubMed

Simão, Daniel; Arez, Francisca; Terasso, Ana P; Pinto, Catarina; Sousa, Marcos F Q; Brito, Catarina; Alves, Paula M

2016-01-01

Therapeutic breakthroughs in neurological disorders have been hampered by the lack of accurate central nervous system (CNS) models. The development of these models allows the study of the disease onset/progression mechanisms and the preclinical evaluation of new therapeutics. This has traditionally relied on genetically engineered animal models that often diverge considerably from the human phenotype (developmental, anatomic, and physiological) and 2D in vitro cell models, which fail to recapitulate the characteristics of the target tissue (cell-cell and cell-matrix interactions, cell polarity, etc.). Recapitulation of CNS phenotypic and functional features in vitro requires the implementation of advanced culture strategies, such as 3D culture systems, which enable to mimic the in vivo structural and molecular complexity. Models based on differentiation of human neural stem cells (hNSC) in 3D cultures have great potential as complementary tools in preclinical research, bridging the gap between human clinical studies and animal models. The development of robust and scalable processes for the 3D differentiation of hNSC can improve the accuracy of early stage development in preclinical research. In this context, the use of software-controlled stirred-tank bioreactors (STB) provides an efficient technological platform for hNSC aggregation and differentiation. This system enables to monitor and control important physicochemical parameters for hNSC culture, such as dissolved oxygen. Importantly, the adoption of a perfusion operation mode allows a stable flow of nutrients and differentiation/neurotrophic factors, while clearing the toxic by-products. This contributes to a setting closer to the physiological, by mimicking the in vivo microenvironment. In this chapter, we address the technical requirements and procedures for the implementation of 3D differentiation strategies of hNSC, by operating STB under perfusion mode for long-term cultures. This strategy is suitable for the generation of human 3D neural in vitro models, which can be used to feed high-throughput screening platforms, contributing to expand the available in vitro tools for drug screening and toxicological studies.

In Vitro Differentiation of Human Mesenchymal Stem Cells into Functional Cardiomyocyte-like Cells.

PubMed

Szaraz, Peter; Gratch, Yarden S; Iqbal, Farwah; Librach, Clifford L

2017-08-09

Myocardial infarction and the subsequent ischemic cascade result in the extensive loss of cardiomyocytes, leading to congestive heart failure, the leading cause of mortality worldwide. Mesenchymal stem cells (MSCs) are a promising option for cell-based therapies to replace current, invasive techniques. MSCs can differentiate into mesenchymal lineages, including cardiac cell types, but complete differentiation into functional cells has not yet been achieved. Previous methods of differentiation were based on pharmacological agents or growth factors. However, more physiologically relevant strategies can also enable MSCs to undergo cardiomyogenic transformation. Here, we present a differentiation method using MSC aggregates on cardiomyocyte feeder layers to produce cardiomyocyte-like contracting cells. Human umbilical cord perivascular cells (HUCPVCs) have been shown to have a greater differentiation potential than commonly investigated MSC types, such as bone marrow MSCs (BMSCs). As an ontogenetically younger source, we investigated the cardiomyogenic potential of first-trimester (FTM) HUCPVCs compared to older sources. FTM HUCPVCs are a novel, rich source of MSCs that retain their in utero immunoprivileged properties when cultured in vitro. Using this differentiation protocol, FTM and term HUCPVCs achieved significantly increased cardiomyogenic differentiation compared to BMSCs, as indicated by the increased expression of cardiomyocyte markers (i.e., myocyte enhancer factor 2C, cardiac troponin T, heavy chain cardiac myosin, signal regulatory protein α, and connexin 43). They also maintained significantly lower immunogenicity, as demonstrated by their lower HLA-A expression and higher HLA-G expression. Applying aggregate-based differentiation, FTM HUCPVCs showed increased aggregate formation potential and generated contracting cells clusters within 1 week of co-culture on cardiac feeder layers, becoming the first MSC type to do so. Our results demonstrate that this differentiation strategy can effectively harness the cardiomyogenic potential of young MSCs, such as FTM HUCPVCs, and suggests that in vitro pre-differentiation could be a potential strategy to increase their regenerative efficacy in vivo.

Functional characterization of Anaphase Promoting Complex/Cyclosome (APC/C) E3 ubiquitin ligases in tumorigenesis

PubMed Central

Zhang, Jinfang; Wan, Lixin; Dai, Xiangpeng; Sun, Yi; Wei, Wenyi

2014-01-01

The Anaphase Promoting Complex/Cyclosome (APC/C) is a multi-subunit E3 ubiquitin ligase that primarily governs cell cycle progression. APC/C is composed of at least 14 core subunits and recruits its substrates for ubiquitination via one of the two adaptor proteins, Cdc20 or Cdh1, in M or M/early G1 phase, respectively. Furthermore, recent studies have shed light on crucial functions for APC/C in maintaining genomic integrity, neuronal differentiation, cellular metabolism and tumorigenesis. To gain better insight into the in vivo physiological functions of APC/C in regulating various cellular processes, particularly development and tumorigenesis, a number of mouse models of APC/C core subunits, coactivators or inhibitors have been established and characterized. However, due to their essential role in cell cycle regulation, most of the germline knockout mice targeting the APC/C pathway are embryonic lethal, indicating the need for generating conditional knockout mouse models to assess the role in tumorigenesis for each APC/C signaling component in specific tissues. In this review, we will first provide a brief introduction of the ubiquitin-proteasome system (UPS) and the biochemical activities and cellular functions of the APC/C E3 ligase. We will then focus primarily on characterizing genetic mouse models used to understand the physiological roles of each APC/C signaling component in embryogenesis, cell proliferation, development and carcinogenesis. Finally, we discuss future research directions to further elucidate the physiological contributions of APC/C components during tumorigenesis and validate their potentials as a novel class of anti-cancer targets. PMID:24569229

Conducting polymers with immobilised fibrillar collagen for enhanced neural interfacing.

PubMed

Liu, Xiao; Yue, Zhilian; Higgins, Michael J; Wallace, Gordon G

2011-10-01

Conducting polymers with pendant functionality are advantageous in various bionic and organic bioelectronic applications, as they allow facile incorporation of bio-regulative cues to provide bio-mimicry and conductive environments for cell growth, differentiation and function. In this work, polypyrrole substrates doped with chondroitin sulfate (CS), an extracellular matrix molecule bearing carboxylic acid moieties, were electrochemically synthesized and conjugated with type I collagen. During the coupling process, the conjugated collagen formed a 3-dimensional fibrillar matrix in situ at the conducting polymer interface, as evidenced by atomic force microscopy (AFM) and fluorescence microscopy under aqueous physiological conditions. Cyclic voltammetry (CV) and impedance measurement confirmed no significant reduction in the electroactivity of the fibrillar collagen-modified conducting polymer substrates. Rat pheochromocytoma (nerve) cells showed increased differentiation and neurite outgrowth on the fibrillar collagen, which was further enhanced through electrical stimulation of the underlying conducting polymer substrate. Our study demonstrates that the direct coupling of ECM components such as collagen, followed by their further self-assembly into 3-dimensional matrices, has the potential to improve the neural-electrode interface of implant electrodes by encouraging nerve cell attachment and differentiation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Functional roles of cell surface peptidases in reproductive organs

PubMed Central

2004-01-01

A number of biologically active peptides have been proposed to regulate function and differentiation of reproductive organs in an autocrine and/or paracrine fashion. Regulation of the local concentrations of these peptides is one of the important factors influencing their physiological effects on target cells. Membrane‐bound cell surface peptidases can activate or inactivate biologically active peptides before peptide factors access their receptors on the cell surface. Aminopeptidase A (EC 3.4.11.7), placental leucine aminopeptidase (EC 3.4.11.3), aminopeptidase‐N/CD13 (EC 3.4.11.2), dipeptidyl peptidases IV/CD26 (EC.3.4.14.5), carboxypeptidase‐M (EC 3.4.17.12), neutral endopeptidase/CD10 (EC 3.4.24.11) and endothelin converting enzyme‐1 (EC 3.4.23) are differentially expressed on the ovary, endometrium and placenta. The inhibition of enzyme activity affects steroid hormone production by granulosa and thecal cells, decidualization of endometrium and migration of extravillous trophoblasts. These findings suggest that membrane‐bound cell surface peptidases are local regulators for cellular growth and differentiation in reproductive organs by controlling extracellular concentration of peptide factors. (Reprod Med Biol 2004; 3: 165 –176) PMID:29662383

Hormonal and transcriptional profiles highlight common and differential host responses to arbuscular mycorrhizal fungi and the regulation of the oxylipin pathway

PubMed Central

López-Ráez, Juan A.; Verhage, Adriaan; Fernández, Iván; García, Juan M.; Azcón-Aguilar, Concepción; Flors, Victor; Pozo, María J.

2010-01-01

Arbuscular mycorrhizal (AM) symbioses are mutualistic associations between soil fungi and most vascular plants. The symbiosis significantly affects the host physiology in terms of nutrition and stress resistance. Despite the lack of host range specificity of the interaction, functional diversity between AM fungal species exists. The interaction is finely regulated according to plant and fungal characters, and plant hormones are believed to orchestrate the modifications in the host plant. Using tomato as a model, an integrative analysis of the host response to different mycorrhizal fungi was performed combining multiple hormone determination and transcriptional profiling. Analysis of ethylene-, abscisic acid-, salicylic acid-, and jasmonate-related compounds evidenced common and divergent responses of tomato roots to Glomus mosseae and Glomus intraradices, two fungi differing in their colonization abilities and impact on the host. Both hormonal and transcriptional analyses revealed, among others, regulation of the oxylipin pathway during the AM symbiosis and point to a key regulatory role for jasmonates. In addition, the results suggest that specific responses to particular fungi underlie the differential impact of individual AM fungi on plant physiology, and particularly on its ability to cope with biotic stresses. PMID:20378666

Swelling and Eicosanoid Metabolites Differentially Gate TRPV4 Channels in Retinal Neurons and Glia

PubMed Central

Ryskamp, Daniel A.; Jo, Andrew O.; Frye, Amber M.; Vazquez-Chona, Felix; MacAulay, Nanna; Thoreson, Wallace B.

2014-01-01

Activity-dependent shifts in ionic concentrations and water that accompany neuronal and glial activity can generate osmotic forces with biological consequences for brain physiology. Active regulation of osmotic gradients and cellular volume requires volume-sensitive ion channels. In the vertebrate retina, critical support to volume regulation is provided by Müller astroglia, but the identity of their osmosensor is unknown. Here, we identify TRPV4 channels as transducers of mouse Müller cell volume increases into physiological responses. Hypotonic stimuli induced sustained [Ca2+]i elevations that were inhibited by TRPV4 antagonists and absent in TRPV4−/− Müller cells. Glial TRPV4 signals were phospholipase A2- and cytochrome P450-dependent, characterized by slow-onset and Ca2+ waves, and, in excess, were sufficient to induce reactive gliosis. In contrast, neurons responded to TRPV4 agonists and swelling with fast, inactivating Ca2+ signals that were independent of phospholipase A2. Our results support a model whereby swelling and proinflammatory signals associated with arachidonic acid metabolites differentially gate TRPV4 in retinal neurons and glia, with potentially significant consequences for normal and pathological retinal function. PMID:25411497

CellLineNavigator: a workbench for cancer cell line analysis

PubMed Central

Krupp, Markus; Itzel, Timo; Maass, Thorsten; Hildebrandt, Andreas; Galle, Peter R.; Teufel, Andreas

2013-01-01

The CellLineNavigator database, freely available at http://www.medicalgenomics.org/celllinenavigator, is a web-based workbench for large scale comparisons of a large collection of diverse cell lines. It aims to support experimental design in the fields of genomics, systems biology and translational biomedical research. Currently, this compendium holds genome wide expression profiles of 317 different cancer cell lines, categorized into 57 different pathological states and 28 individual tissues. To enlarge the scope of CellLineNavigator, the database was furthermore closely linked to commonly used bioinformatics databases and knowledge repositories. To ensure easy data access and search ability, a simple data and an intuitive querying interface were implemented. It allows the user to explore and filter gene expression, focusing on pathological or physiological conditions. For a more complex search, the advanced query interface may be used to query for (i) differentially expressed genes; (ii) pathological or physiological conditions; or (iii) gene names or functional attributes, such as Kyoto Encyclopaedia of Genes and Genomes pathway maps. These queries may also be combined. Finally, CellLineNavigator allows additional advanced analysis of differentially regulated genes by a direct link to the Database for Annotation, Visualization and Integrated Discovery (DAVID) Bioinformatics Resources. PMID:23118487

Teaching Cardiovascular Physiology with Equivalent Electronic Circuits in a Practically Oriented Teaching Module

ERIC Educational Resources Information Center

Ribaric, Samo; Kordas, Marjan

2011-01-01

Here, we report on a new tool for teaching cardiovascular physiology and pathophysiology that promotes qualitative as well as quantitative thinking about time-dependent physiological phenomena. Quantification of steady and presteady-state (transient) cardiovascular phenomena is traditionally done by differential equations, but this is time…

Exploring physiological plasticity and local thermal adaptation in an intertidal crab along a latitudinal cline.

PubMed

Gaitán-Espitia, Juan Diego; Bacigalupe, Leonardo D; Opitz, Tania; Lagos, Nelson A; Osores, Sebastián; Lardies, Marco A

2017-08-01

Intertidal organisms have evolved physiological mechanisms that enable them to maintain performance and survive during periods of severe environmental stress with temperatures close to their tolerance limits. The level of these adaptive responses in thermal physiology can vary among populations of broadly distributed species depending on their particular environmental context and genetic backgrounds. Here we examined thermal performances and reaction norms for metabolic rate (MR) and heart rate (HR) of seven populations of the porcelanid crab Petrolisthes violaceus from markedly different thermal environments across the latitudinal gradient of ~3000km. Physiological responses of this intertidal crab under common-garden conditions suggest the absence of local thermal adaptation along the geographic gradient (i.e., lack of latitudinal compensation). Moreover, thermal physiological sensitivities and performances in response to increased temperatures evidenced the existence of some level of: i) metabolic rate control or depression during warm temperature exposures; and ii) homeostasis/canalization (i.e., absence or low levels of plasticity) in physiological traits that may reflect some sort of buffering mechanism in most of the populations. Nevertheless, our results indicate that elevated temperatures can reduce cardiac function but not metabolic rate in high latitude crabs. The lack of congruence between HR and MR supports the idea that energy metabolism in marine invertebrates cannot be inferred from HR and different conclusions regarding geographic differentiation in energy metabolism can be obtained from both physiological traits. Integrating thermal physiology and species range extent can contribute to a better understanding of the likely effects of climate change on natural populations of marine ectotherms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Muscle RANK is a key regulator of Ca2+ storage, SERCA activity, and function of fast-twitch skeletal muscles.

PubMed

Dufresne, Sébastien S; Dumont, Nicolas A; Boulanger-Piette, Antoine; Fajardo, Val A; Gamu, Daniel; Kake-Guena, Sandrine-Aurélie; David, Rares Ovidiu; Bouchard, Patrice; Lavergne, Éliane; Penninger, Josef M; Pape, Paul C; Tupling, A Russell; Frenette, Jérôme

2016-04-15

Receptor-activator of nuclear factor-κB (RANK), its ligand RANKL, and the soluble decoy receptor osteoprotegerin are the key regulators of osteoclast differentiation and bone remodeling. Here we show that RANK is also expressed in fully differentiated myotubes and skeletal muscle. Muscle RANK deletion has inotropic effects in denervated, but not in sham, extensor digitorum longus (EDL) muscles preventing the loss of maximum specific force while promoting muscle atrophy, fatigability, and increased proportion of fast-twitch fibers. In denervated EDL muscles, RANK deletion markedly increased stromal interaction molecule 1 content, a Ca(2+)sensor, and altered activity of the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) modulating Ca(2+)storage. Muscle RANK deletion had no significant effects on the sham or denervated slow-twitch soleus muscles. These data identify a novel role for RANK as a key regulator of Ca(2+)storage and SERCA activity, ultimately affecting denervated skeletal muscle function. Copyright © 2016 the American Physiological Society.

Multiple, Distinct Isoforms of Sucrose Synthase in Pea1

PubMed Central

Barratt, D.H. Paul; Barber, Lorraine; Kruger, Nicholas J.; Smith, Alison M.; Wang, Trevor L.; Martin, Cathie

2001-01-01

Genes encoding three isoforms of sucrose synthase (Sus1, Sus2, and Sus3) have been cloned from pea (Pisum sativum). The genes have distinct patterns of expression in different organs of the plant, and during organ development. Studies of the isoforms expressed as recombinant proteins in Escherichia coli show that they differ in kinetic properties. Although not of great magnitude, the differences in properties are consistent with some differentiation of physiological function between the isoforms. Evidence for differentiation of function in vivo comes from the phenotypes of rug4 mutants of pea, which carry mutations in the gene encoding Sus1. One mutant line (rug4-c) lacks detectable Sus1 protein in both the soluble and membrane-associated fractions of the embryo, and Sus activity in the embryo is reduced by 95%. The starch content of the embryo is reduced by 30%, but the cellulose content is unaffected. The results imply that different isoforms of Sus may channel carbon from sucrose towards different metabolic fates within the cell. PMID:11598239

Extensive alternative splicing transitions during postnatal skeletal muscle development are required for calcium handling functions

PubMed Central

Brinegar, Amy E; Xia, Zheng; Loehr, James Anthony; Li, Wei; Rodney, George Gerald

2017-01-01

Postnatal development of skeletal muscle is a highly dynamic period of tissue remodeling. Here, we used RNA-seq to identify transcriptome changes from late embryonic to adult mouse muscle and demonstrate that alternative splicing developmental transitions impact muscle physiology. The first 2 weeks after birth are particularly dynamic for differential gene expression and alternative splicing transitions, and calcium-handling functions are significantly enriched among genes that undergo alternative splicing. We focused on the postnatal splicing transitions of the three calcineurin A genes, calcium-dependent phosphatases that regulate multiple aspects of muscle biology. Redirected splicing of calcineurin A to the fetal isoforms in adult muscle and in differentiated C2C12 slows the timing of muscle relaxation, promotes nuclear localization of calcineurin target Nfatc3, and/or affects expression of Nfatc transcription targets. The results demonstrate a previously unknown specificity of calcineurin isoforms as well as the broader impact of alternative splicing during muscle postnatal development. PMID:28826478

Glutathione Degradation.

PubMed

Bachhawat, Anand Kumar; Kaur, Amandeep

2017-11-20

Glutathione degradation has for long been thought to occur only on noncytosolic pools. This is because there has been only one enzyme known to degrade glutathione (γ-glutamyl transpeptidase) and this localizes to either the plasma membrane (mammals, bacteria) or the vacuolar membrane (yeast, plants) and acts on extracellular or vacuolar pools. The last few years have seen the discovery of several new enzymes of glutathione degradation that function in the cytosol, throwing new light on glutathione degradation. Recent Advances: The new enzymes that have been identified in the last few years that can initiate glutathione degradation include the Dug enzyme found in yeast and fungi, the ChaC1 enzyme found among higher eukaryotes, the ChaC2 enzyme found from bacteria to man, and the RipAY enzyme found in some bacteria. These enzymes play roles ranging from housekeeping functions to stress responses and are involved in processes such as embryonic neural development and pathogenesis. In addition to delineating the pathways of glutathione degradation in detail, a critical issue is to find how these new enzymes impact cellular physiology and homeostasis. Glutathione degradation plays a far greater role in cellular physiology than previously envisaged. The differential regulation and differential specificities of various enzymes, each acting on distinct pools, can lead to different consequences to the cell. It is likely that the coming years will see these downstream effects being unraveled in greater detail and will lead to a better understanding and appreciation of glutathione degradation. Antioxid. Redox Signal. 27, 1200-1216.

Role of Doppler Diastolic Parameters in Differentiating Physiological Left Ventricular Hypertrophy from Hypertrophic Cardiomyopathy.

PubMed

Finocchiaro, Gherardo; Dhutia, Harshil; D'Silva, Andrew; Malhotra, Aneil; Sheikh, Nabeel; Narain, Rajay; Ensam, Bode; Papatheodorou, Stathis; Tome, Maite; Sharma, Rajan; Papadakis, Michael; Sharma, Sanjay

2018-05-01

The association between athletic participation and alteration in diastolic function is not well established. The aims of this study were to determine the spectrum of Doppler parameters of left ventricular (LV) diastolic function in a large cohort of healthy athletes and to quantify the overlap between physiologic LV hypertrophy and hypertrophic cardiomyopathy (HCM). A retrospective analysis of indices of LV diastolic function was performed in 1,510 healthy athletes (mean age, 22 ± 5 years; range, 13-33 years; 72% men). The results were compared with those from 58 young patients with HCM. Septal E' < 7 cm/sec and lateral E' < 10 cm/sec were found in five (0.3%) and eight (0.5%) athletes, respectively. Septal E' was >14.6 cm/sec in 170 (11%) and lateral E' was >19.9 cm/sec in 430 (28%) athletes. Athletes aged >25 years showed lower E' velocities compared with younger athletes (mean septal E', 11.8 ± 6.1 vs 12.9 ± 5.9 cm/sec [P < .001]; mean lateral E', 17.1 ± 3.6 vs 19.3 ± 4.1 cm/sec [P < .001]). Athletes with high indexed LV end-diastolic diameters (>32 mm/m 2 ) exhibited lower septal E' compared with athletes with normal indexed LV end-diastolic diameters (mean septal E', 11.9 ± 6 vs 12.7 ± 6 cm/sec; P = .002). Septal E' < 10 cm/sec and lateral E' < 12 cm/sec showed the best accuracy in differentiating between HCM and athlete's heart. Reduced septal and lateral E' are rarely observed in young elite athletes. Tissue Doppler velocities tend to decrease with increasing age and LV size, and values representative of supernormal diastolic function are found in less than one-third of young athletes. Cutoff thresholds for Doppler parameters of diastolic function should be corrected for multiple demographic and clinical variables to differentiate cardiac adaptation to exercise from HCM in young individuals. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Genetic dissection of endothelial transcriptional activity of zebrafish aryl hydrocarbon receptors (AHRs).

PubMed

Sugden, Wade W; Leonardo-Mendonça, Roberto C; Acuña-Castroviejo, Darío; Siekmann, Arndt F

2017-01-01

The aryl hydrocarbon receptor (AHR) is a basic helix-loop-helix transcription factor conserved across phyla from flies to humans. Activated by a number of endogenous ligands and environmental toxins, studies on AHR function and gene regulation have largely focused on a toxicological perspective relating to aromatic hydrocarbons generated by human activities and the often-deleterious effects of exposure on vertebrates mediated by AHR activation. A growing body of work has highlighted the importance of AHR in physiologic processes, including immune cell differentiation and vascular patterning. Here we dissect the contribution of the 3 zebrafish AHRs, ahr1a, ahr1b and ahr2, to endothelial cyp1a1/b1 gene regulation under physiologic conditions and upon exposure to the AHR ligand Beta-naphthoflavone. We show that in fish multiple AHRs are functional in the vasculature, with vessel-specific differences in the ability of ahr1b to compensate for the loss of ahr2 to maintain AHR signaling. We further provide evidence that AHR can regulate the expression of the chemokine receptor cxcr4a in endothelial cells, a regulatory mechanism that may provide insight into AHR function in the endothelium.

Gap junctions in cells of the immune system: structure, regulation and possible functional roles.

PubMed

Sáez, J C; Brañes, M C; Corvalán, L A; Eugenín, E A; González, H; Martínez, A D; Palisson, F

2000-04-01

Gap junction channels are sites of cytoplasmic communication between contacting cells. In vertebrates, they consist of protein subunits denoted connexins (Cxs) which are encoded by a gene family. According to their Cx composition, gap junction channels show different gating and permeability properties that define which ions and small molecules permeate them. Differences in Cx primary sequences suggest that channels composed of different Cxs are regulated differentially by intracellular pathways under specific physiological conditions. Functional roles of gap junction channels could be defined by the relative importance of permeant substances, resulting in coordination of electrical and/or metabolic cellular responses. Cells of the native and specific immune systems establish transient homo- and heterocellular contacts at various steps of the immune response. Morphological and functional studies reported during the last three decades have revealed that many intercellular contacts between cells in the immune response present gap junctions or "gap junction-like" structures. Partial characterization of the molecular composition of some of these plasma membrane structures and regulatory mechanisms that control them have been published recently. Studies designed to elucidate their physiological roles suggest that they might permit coordination of cellular events which favor the effective and timely response of the immune system.

Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis

PubMed Central

Großkinsky, Dominik K.; Tafner, Richard; Moreno, María V.; Stenglein, Sebastian A.; García de Salamone, Inés E.; Nelson, Louise M.; Novák, Ondřej; Strnad, Miroslav; van der Graaff, Eric; Roitsch, Thomas

2016-01-01

Plant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinin-deficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbe-based, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience. PMID:26984671

Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis.

PubMed

Großkinsky, Dominik K; Tafner, Richard; Moreno, María V; Stenglein, Sebastian A; García de Salamone, Inés E; Nelson, Louise M; Novák, Ondřej; Strnad, Miroslav; van der Graaff, Eric; Roitsch, Thomas

2016-03-17

Plant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinin-deficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbe-based, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience.

Analyses of a Mutant Foxp3 Allele Reveal BATF as a Critical Transcription Factor in the Differentiation and Accumulation of Tissue Regulatory T Cells.

PubMed

Hayatsu, Norihito; Miyao, Takahisa; Tachibana, Masashi; Murakami, Ryuichi; Kimura, Akihiko; Kato, Takako; Kawakami, Eiryo; Endo, Takaho A; Setoguchi, Ruka; Watarai, Hiroshi; Nishikawa, Takeshi; Yasuda, Takuwa; Yoshida, Hisahiro; Hori, Shohei

2017-08-15

Foxp3 controls the development and function of regulatory T (Treg) cells, but it remains elusive how Foxp3 functions in vivo. Here, we established mouse models harboring three unique missense Foxp3 mutations that were identified in patients with the autoimmune disease IPEX. The I363V and R397W mutations were loss-of-function mutations, causing multi-organ inflammation by globally compromising Treg cell physiology. By contrast, the A384T mutation induced a distinctive tissue-restricted inflammation by specifically impairing the ability of Treg cells to compete with pathogenic T cells in certain non-lymphoid tissues. Mechanistically, repressed BATF expression contributed to these A384T effects. At the molecular level, the A384T mutation altered Foxp3 interactions with its specific target genes including Batf by broadening its DNA-binding specificity. Our findings identify BATF as a critical regulator of tissue Treg cells and suggest that sequence-specific perturbations of Foxp3-DNA interactions can influence specific facets of Treg cell physiology and the immunopathologies they regulate. Copyright © 2017 Elsevier Inc. All rights reserved.

Ecosystems Biology Approaches To Determine Key Fitness Traits of Soil Microorganisms

NASA Astrophysics Data System (ADS)

Brodie, E.; Zhalnina, K.; Karaoz, U.; Cho, H.; Nuccio, E. E.; Shi, S.; Lipton, M. S.; Zhou, J.; Pett-Ridge, J.; Northen, T.; Firestone, M.

2014-12-01

The application of theoretical approaches such as trait-based modeling represent powerful tools to explain and perhaps predict complex patterns in microbial distribution and function across environmental gradients in space and time. These models are mostly deterministic and where available are built upon a detailed understanding of microbial physiology and response to environmental factors. However as most soil microorganisms have not been cultivated, for the majority our understanding is limited to insights from environmental 'omic information. Information gleaned from 'omic studies of complex systems should be regarded as providing hypotheses, and these hypotheses should be tested under controlled laboratory conditions if they are to be propagated into deterministic models. In a semi-arid Mediterranean grassland system we are attempting to dissect microbial communities into functional guilds with defined physiological traits and are using a range of 'omics approaches to characterize their metabolic potential and niche preference. Initially, two physiologically relevant time points (peak plant activity and prior to wet-up) were sampled and metagenomes sequenced deeply (600-900 Gbp). Following assembly, differential coverage and nucleotide frequency binning were carried out to yield draft genomes. In addition, using a range of cultivation media we have isolated a broad range of bacteria representing abundant bacterial genotypes and with genome sequences of almost 40 isolates are testing genomic predictions regarding growth rate, temperature and substrate utilization in vitro. This presentation will discuss the opportunities and challenges in parameterizing microbial functional guilds from environmental 'omic information for use in trait-based models.

Predicted Arabidopsis Interactome Resource and Gene Set Linkage Analysis: A Transcriptomic Analysis Resource.

PubMed

Yao, Heng; Wang, Xiaoxuan; Chen, Pengcheng; Hai, Ling; Jin, Kang; Yao, Lixia; Mao, Chuanzao; Chen, Xin

2018-05-01

An advanced functional understanding of omics data is important for elucidating the design logic of physiological processes in plants and effectively controlling desired traits in plants. We present the latest versions of the Predicted Arabidopsis Interactome Resource (PAIR) and of the gene set linkage analysis (GSLA) tool, which enable the interpretation of an observed transcriptomic change (differentially expressed genes [DEGs]) in Arabidopsis ( Arabidopsis thaliana ) with respect to its functional impact for biological processes. PAIR version 5.0 integrates functional association data between genes in multiple forms and infers 335,301 putative functional interactions. GSLA relies on this high-confidence inferred functional association network to expand our perception of the functional impacts of an observed transcriptomic change. GSLA then interprets the biological significance of the observed DEGs using established biological concepts (annotation terms), describing not only the DEGs themselves but also their potential functional impacts. This unique analytical capability can help researchers gain deeper insights into their experimental results and highlight prospective directions for further investigation. We demonstrate the utility of GSLA with two case studies in which GSLA uncovered how molecular events may have caused physiological changes through their collective functional influence on biological processes. Furthermore, we showed that typical annotation-enrichment tools were unable to produce similar insights to PAIR/GSLA. The PAIR version 5.0-inferred interactome and GSLA Web tool both can be accessed at http://public.synergylab.cn/pair/. © 2018 American Society of Plant Biologists. All Rights Reserved.

The endogenous retroviral locus ERVWE1 is a bona fide gene involved in hominoid placental physiology

PubMed Central

Mallet, François; Bouton, Olivier; Prudhomme, Sarah; Cheynet, Valérie; Oriol, Guy; Bonnaud, Bertrand; Lucotte, Gérard; Duret, Laurent; Mandrand, Bernard

2004-01-01

The definitive demonstration of a role for a recently acquired gene is a difficult task, requiring exhaustive genetic investigations and functional analysis. The situation is indeed much more complicated when facing multicopy gene families, because most or portions of the gene are conserved among the hundred copies of the family. This is the case for the ERVWE1 locus of the human endogenous retrovirus W family (HERV-W), which encodes an envelope glycoprotein (syncytin) likely involved in trophoblast differentiation. Here we describe, in 155 individuals, the positional conservation of this locus and the preservation of the envelope ORF. Sequencing of the critical elements of the ERVWE1 provirus showed a striking conservation among the 48 alleles of 24 individuals, including the LTR elements involved in the transcriptional machinery, the splice sites involved in the maturation of subgenomic Env mRNA, and the Env ORF. The functionality and tissue specificity of the 5′ LTR were demonstrated, as well as the fusogenic activity of the envelope polymorphic variants. Such functions were also shown to be preserved in the orthologous loci isolated from chimpanzee, gorilla, orangutan, and gibbon. This functional preservation among humans and during evolution strongly argued for the involvement of this recently acquired retroviral envelope glycoprotein in hominoid placental physiology. PMID:14757826

Specifications of insilicoML 1.0: a multilevel biophysical model description language.

PubMed

Asai, Yoshiyuki; Suzuki, Yasuyuki; Kido, Yoshiyuki; Oka, Hideki; Heien, Eric; Nakanishi, Masao; Urai, Takahito; Hagihara, Kenichi; Kurachi, Yoshihisa; Nomura, Taishin

2008-12-01

An extensible markup language format, insilicoML (ISML), version 0.1, describing multi-level biophysical models has been developed and available in the public domain. ISML is fully compatible with CellML 1.0, a model description standard developed by the IUPS Physiome Project, for enhancing knowledge integration and model sharing. This article illustrates the new specifications of ISML 1.0 that largely extend the capability of ISML 0.1. ISML 1.0 can describe various types of mathematical models, including ordinary/partial differential/difference equations representing the dynamics of physiological functions and the geometry of living organisms underlying the functions. ISML 1.0 describes a model using a set of functional elements (modules) each of which can specify mathematical expressions of the functions. Structural and logical relationships between any two modules are specified by edges, which allow modular, hierarchical, and/or network representations of the model. The role of edge-relationships is enriched by key words in order for use in constructing a physiological ontology. The ontology is further improved by the traceability of history of the model's development and by linking between different ISML models stored in the model's database using meta-information. ISML 1.0 is designed to operate with a model database and integrated environments for model development and simulations for knowledge integration and discovery.

Elucidating the functional role of endoreduplication in tomato fruit development

PubMed Central

Chevalier, Christian; Nafati, Mehdi; Mathieu-Rivet, Elodie; Bourdon, Matthieu; Frangne, Nathalie; Cheniclet, Catherine; Renaudin, Jean-Pierre; Gévaudant, Frédéric; Hernould, Michel

2011-01-01

Background Endoreduplication is the major source of endopolyploidy in higher plants. The process of endoreduplication results from the ability of cells to modify their classical cell cycle into a partial cell cycle where DNA synthesis occurs independently from mitosis. Despite the ubiquitous occurrence of the phenomenon in eukaryotic cells, the physiological meaning of endoreduplication remains vague,although several roles during plant development have been proposed, mostly related to cell differentiation and cell size determination. Scope Here recent advances in the knowledge of endoreduplication and fruit organogenesis are reviewed, focusing on tomato (Solanum lycopersicum) as a model, and the functional analyses of endoreduplication-associated regulatory genes in tomato fruit are described. Conclusions The cyclin-dependent kinase inhibitory kinase WEE1 and the anaphase promoting complex activator CCS52A both participate in the control of cell size and the endoreduplication process driving cell expansion during early fruit development in tomato. Moreover the fruit-specific functional analysis of the tomato CDK inhibitor KRP1 reveals that cell size and fruit size determination can be uncoupled from DNA ploidy levels, indicating that endoreduplication acts rather as a limiting factor for cell growth. The overall functional data contribute to unravelling the physiological role of endoreduplication in growth induction of fleshy fruits. PMID:21199834

Quantitative proteomics and systems analysis of cultured H9C2 cardiomyoblasts during differentiation over time supports a 'function follows form' model of differentiation.

PubMed

Kankeu, Cynthia; Clarke, Kylie; Van Haver, Delphi; Gevaert, Kris; Impens, Francis; Dittrich, Anna; Roderick, H Llewelyn; Passante, Egle; Huber, Heinrich J

2018-05-17

The rat cardiomyoblast cell line H9C2 has emerged as a valuable tool for studying cardiac development, mechanisms of disease and toxicology. We present here a rigorous proteomic analysis that monitored the changes in protein expression during differentiation of H9C2 cells into cardiomyocyte-like cells over time. Quantitative mass spectrometry followed by gene ontology (GO) enrichment analysis revealed that early changes in H9C2 differentiation are related to protein pathways of cardiac muscle morphogenesis and sphingolipid synthesis. These changes in the proteome were followed later in the differentiation time-course by alterations in the expression of proteins involved in cation transport and beta-oxidation. Studying the temporal profile of the H9C2 proteome during differentiation in further detail revealed eight clusters of co-regulated proteins that can be associated with early, late, continuous and transient up- and downregulation. Subsequent reactome pathway analysis based on these eight clusters further corroborated and detailed the results of the GO analysis. Specifically, this analysis confirmed that proteins related to pathways in muscle contraction are upregulated early and transiently, and proteins relevant to extracellular matrix organization are downregulated early. In contrast, upregulation of proteins related to cardiac metabolism occurs at later time points. Finally, independent validation of the proteomics results by immunoblotting confirmed hereto unknown regulators of cardiac structure and ionic metabolism. Our results are consistent with a 'function follows form' model of differentiation, whereby early and transient alterations of structural proteins enable subsequent changes that are relevant to the characteristic physiology of cardiomyocytes.

The Plasminogen Activation System Modulates Differently Adipogenesis and Myogenesis of Embryonic Stem Cells

PubMed Central

Hadadeh, Ola; Barruet, Emilie; Peiretti, Franck; Verdier, Monique; Bernot, Denis; Hadjal, Yasmine; Yazidi, Claire El; Robaglia-Schlupp, Andrée; De Paula, Andre Maues; Nègre, Didier; Iacovino, Michelina; Kyba, Michael; Alessi, Marie-Christine; Binétruy, Bernard

2012-01-01

Regulation of the extracellular matrix (ECM) plays an important functional role either in physiological or pathological conditions. The plasminogen activation (PA) system, comprising the uPA and tPA proteases and their inhibitor PAI-1, is one of the main suppliers of extracellular proteolytic activity contributing to tissue remodeling. Although its function in development is well documented, its precise role in mouse embryonic stem cell (ESC) differentiation in vitro is unknown. We found that the PA system components are expressed at very low levels in undifferentiated ESCs and that upon differentiation uPA activity is detected mainly transiently, whereas tPA activity and PAI-1 protein are maximum in well differentiated cells. Adipocyte formation by ESCs is inhibited by amiloride treatment, a specific uPA inhibitor. Likewise, ESCs expressing ectopic PAI-1 under the control of an inducible expression system display reduced adipogenic capacities after induction of the gene. Furthermore, the adipogenic differentiation capacities of PAI-1−/− induced pluripotent stem cells (iPSCs) are augmented as compared to wt iPSCs. Our results demonstrate that the control of ESC adipogenesis by the PA system correspond to different successive steps from undifferentiated to well differentiated ESCs. Similarly, skeletal myogenesis is decreased by uPA inhibition or PAI-1 overexpression during the terminal step of differentiation. However, interfering with uPA during days 0 to 3 of the differentiation process augments ESC myotube formation. Neither neurogenesis, cardiomyogenesis, endothelial cell nor smooth muscle formation are affected by amiloride or PAI-1 induction. Our results show that the PA system is capable to specifically modulate adipogenesis and skeletal myogenesis of ESCs by successive different molecular mechanisms. PMID:23145071

Systemic nature of drought-tolerance in common bean.

PubMed

Montero-Tavera, Víctor; Ruiz-Medrano, Roberto; Xoconostle-Cázares, Beatriz

2008-09-01

The response to drought at the physiological and molecular levels was studied in two common bean varieties with contrasting susceptibility to drought stress. A number of genes were found to be upregulated in the tolerant variety Pinto Villa relative to the susceptible cultivar, Carioca. The products of these genes fell in different functional categories. Further analyses of selected genes, consisting of their spatial differential expression and in situ mRNA accumulation patterns displayed interesting profiles. The drought-tolerant variety displayed a more developed root vasculature in drought conditions, when compared to the susceptible tropical bean Carioca. The in situ localization of three selected genes indicated the accumulation of their corresponding mRNAs in companion cells, sieve tubes and in developing phloem, suggesting that these, and/or the encoded proteins could constitute phloem-mobile signals. Indeed, a number of transcripts that are induced in response to water deficit accumulate in the phloem in other plant species, suggesting a general phenomenon. Moreover, the analysis of drought stress in plant varieties with contrasting tolerance to such stimulus will help to determine the role of differential expression of specific genes in response to such phenomenon, as well as other biochemical, morphological and physiological features in both cultivars.Drought-tolerant plants likely evolved a system that would allow them to maintain its vascular tissue integrity under stress. A functional phloem would then still function in the transmission of long-range signals, important for the systemic adaptation to the stress. It is expected that plants showing increased tolerance to abiotic stress, such as drought, are able to better protect their conductive tissues. This general strategy might help such plants evolve under stress conditions and colonize successfully new habitats.

Physiological and structural differences in spatially distinct subpopulations of cardiac mitochondria: influence of cardiac pathologies

PubMed Central

Thapa, Dharendra; Shepherd, Danielle L.

2014-01-01

Cardiac tissue contains discrete pools of mitochondria that are characterized by their subcellular spatial arrangement. Subsarcolemmal mitochondria (SSM) exist below the cell membrane, interfibrillar mitochondria (IFM) reside in rows between the myofibrils, and perinuclear mitochondria are situated at the nuclear poles. Microstructural imaging of heart tissue coupled with the development of differential isolation techniques designed to sequentially separate spatially distinct mitochondrial subpopulations have revealed differences in morphological features including shape, absolute size, and internal cristae arrangement. These findings have been complemented by functional studies indicating differences in biochemical parameters and, potentially, functional roles for the ATP generated, based upon subcellular location. Consequently, mitochondrial subpopulations appear to be influenced differently during cardiac pathologies including ischemia/reperfusion, heart failure, aging, exercise, and diabetes mellitus. These influences may be the result of specific structural and functional disparities between mitochondrial subpopulations such that the stress elicited by a given cardiac insult differentially impacts subcellular locales and the mitochondria contained within. The goal of this review is to highlight some of the inherent structural and functional differences that exist between spatially distinct cardiac mitochondrial subpopulations as well as provide an overview of the differential impact of various cardiac pathologies on spatially distinct mitochondrial subpopulations. As an outcome, we will instill a basis for incorporating subcellular spatial location when evaluating the impact of cardiac pathologies on the mitochondrion. Incorporation of subcellular spatial location may offer the greatest potential for delineating the influence of cardiac pathology on this critical organelle. PMID:24778166

Stress Chaperone GRP-78 Functions in Mineralized Matrix Formation*

PubMed Central

Ravindran, Sriram; Gao, Qi; Ramachandran, Amsaveni; Blond, Sylvie; Predescu, Sanda A.; George, Anne

2011-01-01

Mineralized matrix formation is a well orchestrated event requiring several players. Glucose-regulated protein-78 (GRP-78) is an endoplasmic reticulum chaperone protein that has been implicated in functional roles ranging from involvement in cancer biology to serving as a receptor for viruses. In the present study we explored the role of GRP-78 in mineralized matrix formation. Differential expression of GRP-78 mRNA and protein was observed upon in vitro differentiation of primary mouse calvarial cells. An interesting observation was that GRP-78 was identified in the secretome of these cells and in the bone matrix, suggesting an extracellular function during matrix formation. In vitro nucleation experiments under physiological concentrations of calcium and phosphate ions indicated that GRP-78 can induce the formation of calcium phosphate polymorphs by itself, when bound to immobilized type I collagen and on demineralized collagen wafers. We provide evidence that GRP-78 can bind to DMP1 and type I collagen independent of each other in a simulated extracellular environment. Furthermore, we demonstrate the cell surface localization of GRP-78 and provide evidence that it functions as a receptor for DMP1 endocytosis in pre-osteoblasts and primary calvarial cells. Overall, this study represents a paradigm shift in the biological function of GRP-78. PMID:21239500

Reactive Oxygen Species and NOX Enzymes Are Emerging as Key Players in Cutaneous Wound Repair

PubMed Central

Modarressi, Ali; Pittet-Cuénod, Brigitte

2017-01-01

Our understanding of the role of oxygen in cell physiology has evolved from its long-recognized importance as an essential factor in oxidative metabolism to its recognition as an important player in cell signaling. With regard to the latter, oxygen is needed for the generation of reactive oxygen species (ROS), which regulate a number of different cellular functions including differentiation, proliferation, apoptosis, migration, and contraction. Data specifically concerning the role of ROS-dependent signaling in cutaneous wound repair are very limited, especially regarding wound contraction. In this review we provide an overview of the current literature on the role of molecular and reactive oxygen in the physiology of wound repair as well as in the pathophysiology and therapy of chronic wounds, especially under ischemic and hyperglycemic conditions. PMID:29036938

Functional compatibility between Purkinje cell axon branches and their target neurons in the cerebellum.

PubMed

Yang, Zhilai; Chen, Na; Ge, Rongjing; Qian, Hao; Wang, Jin-Hui

2017-09-22

A neuron sprouts an axon, and its branches to innervate many target neurons that are divergent in their functions. In order to efficiently regulate the diversified cells, the axon branches should differentiate functionally to be compatible with their target neurons, i.e., a function compatibility between presynaptic and postsynaptic partners. We have examined this hypothesis by using electrophysiological method in the cerebellum, in which the main axon of Purkinje cell projected to deep nucleus cells and the recurrent axons innervated the adjacent Purkinje cells. The fidelity of spike propagation is superior in the recurrent branches than the main axon. The capabilities of encoding spikes and processing GABAergic inputs are advanced in Purkinje cells versus deep nucleus cells. The functional differences among Purkinje's axonal branches and their postsynaptic neurons are preset by the variable dynamics of their voltage-gated sodium channels. In addition, activity strengths between presynaptic and postsynaptic partners are proportionally correlated, i.e., active axonal branches innervate active target neurons, or vice versa. The physiological impact of the functional compatibility is to make the neurons in their circuits to be activated appropriately. In conclusion, each cerebellar Purkinje cell sprouts the differentiated axon branches to be compatible with the diversified target cells in their functions, in order to construct the homeostatic and efficient units for their coordinated activity in neural circuits.

Functional compatibility between Purkinje cell axon branches and their target neurons in the cerebellum

PubMed Central

Qian, Hao; Wang, Jin-Hui

2017-01-01

A neuron sprouts an axon, and its branches to innervate many target neurons that are divergent in their functions. In order to efficiently regulate the diversified cells, the axon branches should differentiate functionally to be compatible with their target neurons, i.e., a function compatibility between presynaptic and postsynaptic partners. We have examined this hypothesis by using electrophysiological method in the cerebellum, in which the main axon of Purkinje cell projected to deep nucleus cells and the recurrent axons innervated the adjacent Purkinje cells. The fidelity of spike propagation is superior in the recurrent branches than the main axon. The capabilities of encoding spikes and processing GABAergic inputs are advanced in Purkinje cells versus deep nucleus cells. The functional differences among Purkinje's axonal branches and their postsynaptic neurons are preset by the variable dynamics of their voltage-gated sodium channels. In addition, activity strengths between presynaptic and postsynaptic partners are proportionally correlated, i.e., active axonal branches innervate active target neurons, or vice versa. The physiological impact of the functional compatibility is to make the neurons in their circuits to be activated appropriately. In conclusion, each cerebellar Purkinje cell sprouts the differentiated axon branches to be compatible with the diversified target cells in their functions, in order to construct the homeostatic and efficient units for their coordinated activity in neural circuits. PMID:29069799

Rhesus Monkey Cumulus Cells Revert to a Mural Granulosa Cell State After an Ovulatory Stimulus

PubMed Central

Chaffin, Charles L.; Lee, Young S.; Patel, Bela G.; Latham, Keith E.

2012-01-01

Follicular somatic cells (mural granulosa cells and cumulus cells) and the oocyte communicate through paracrine interactions and through direct gap junctions between oocyte and cumulus cells. Considering that mural and cumulus cells arise through a common developmental pathway and that their differentiation is essential to reproductive success, understanding how these cells differ is a key aspect to understanding their critical functions. Changes in global gene expression before and after an ovulatory stimulus were compared between cumulus and mural granulosa cells to test the hypothesis that mural and cumulus cells are highly differentiated at the time of an ovulatory stimulus and further differentiate during the periovulatory interval. The transcriptomes of the two cell types were markedly different (>1500 genes) before an ovulatory hCG bolus but converged after ovulation to become completely overlapping. The predominant transition was for the cumulus cells to become more like mural cells after hCG. This indicates that the differentiated phenotype of the cumulus cell is not stable and irreversibly established but may rather be an ongoing physiological response to the oocyte. PMID:23008515

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galloway, Chad A.; Smith, Harold C., E-mail: harold.smith@rochester.edu

Apolipoprotein B mRNA is edited at cytidine 6666 in the enterocytes lining the small intestine of all mammals; converting a CAA codon to a UAA stop codon. The conversion is {approx}80% efficient in this tissue and leads to the expression of the truncated protein, ApoB48, essential for secretion of dietary lipid as chylomicrons. Caco-2 cell raft cultures have been used as an in vitro model for the induction of editing activity during human small intestinal cell differentiation. This induction of apoB mRNA editing has been ascribed to the expression of APOBEC-1. In agreement our data demonstrated differentiation-dependent induction of expressionmore » of the editing enzyme APOBEC-1 and in addition we show alternative splicing of the essential auxiliary factor ACF. However, transfection of these editing factors in undifferentiated proliferating Caco-2 cells was not sufficient to induce robust apoB mRNA editing activity. Only differentiation of Caco-2 cells could induce more physiological like levels of apoB mRNA editing. The data suggested that additional regulatory mechanism(s) were induced by differentiation that controlled the functional activity of editing factors.« less

Constitutive Uncoupling of Pathways of Gene Expression That Control Growth and Differentiation in Myeloid Leukemia: A Model for the Origin and Progression of Malignancy

NASA Astrophysics Data System (ADS)

Sachs, Leo

1980-10-01

Chemical carcinogens and tumor promoters have pleiotropic effects. Tumor initiators can produce a variety of mutations and tumor promoters can regulate a variety of physiological molecules that control growth and differentiation. The appropriate mutation and the regulation of the appropriate molecules to induce cell growth can initiate and promote the sequence of changes required for transformation of normal cells into malignant cells. After this sequence of changes, some tumors can still be induced to revert with a high frequency from a malignant phenotype to a nonmalignant phenotype. Results obtained from analysis of regulation of growth and differentiation in normal and leukemic myeloid cells, the phenotypic reversion of malignancy by induction of normal differentiation in myeloid leukemia, and the blocks in differentiation-defective leukemic cell mutants have been used to propose a general model for the origin and progression of malignancy. The model states that malignancy originates by changing specific pathways of gene expression required for growth from inducible to constitutive in cells that can still be induced to differentiate normally by the physiological inducer of differentiation. The malignant cells, unlike the normal cells, then no longer require the physiological inducer for growth. This changes the requirements for growth and uncouples growth from differentiation. Constitutive expression of other specific pathways can uncouple other controls, which then causes blocks in differentiation and the further progression of malignancy. The existence of specific constitutive pathways of gene expression that uncouple controls in malignant cells can also explain the expression of fetal proteins, hormones, and some other specialized products of normal development in various types of tumors.

Platform for combined analysis of functional and biomolecular phenotypes of the same cell

PubMed Central

Kelbauskas, L.; Ashili, S.; Zeng, J.; Rezaie, A.; Lee, K.; Derkach, D.; Ueberroth, B.; Gao, W.; Paulson, T.; Wang, H.; Tian, Y.; Smith, D.; Reid, B.; Meldrum, Deirdre R.

2017-01-01

Functional and molecular cell-to-cell variability is pivotal at the cellular, tissue and whole-organism levels. Yet, the ultimate goal of directly correlating the function of the individual cell with its biomolecular profile remains elusive. We present a platform for integrated analysis of functional and transcriptional phenotypes in the same single cells. We investigated changes in the cellular respiration and gene expression diversity resulting from adaptation to repeated episodes of acute hypoxia in a premalignant progression model. We find differential, progression stage-specific alterations in phenotypic heterogeneity and identify cells with aberrant phenotypes. To our knowledge, this study is the first demonstration of an integrated approach to elucidate how heterogeneity at the transcriptional level manifests in the physiologic profile of individual cells in the context of disease progression. PMID:28300162

The Role of Akt in Chronic Liver Disease and Liver Regeneration.

PubMed

Morales-Ruiz, Manuel; Santel, Ansgar; Ribera, Jordi; Jiménez, Wladimiro

2017-02-01

The liver is continuously exposed to diverse insults, which may culminate in pathological processes causing liver disease. An effective therapeutic strategy for chronic liver disease should control the causal factors of the disease and stimulate functional liver regeneration. Preclinical studies have shown that interventions aimed at maintaining Akt activity in a dysfunctional liver meet most of the criteria. Although the central function of Akt is cell survival, other cellular aspects such as glucose uptake, glycogen synthesis, cell-cycle progression, and lipid metabolism have been shown to be prominent functions of Akt in the context of hepatic physiology. In this review, the authors describe the benefits of the Akt signaling pathway, emphasizing its importance in coordinating proper cellular growth and differentiation during liver regeneration, hepatic function, and liver disease. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Ulk1-mediated autophagy plays an essential role in mitochondrial remodeling and functional regeneration of skeletal muscle.

PubMed

Call, Jarrod A; Wilson, Rebecca J; Laker, Rhianna C; Zhang, Mei; Kundu, Mondira; Yan, Zhen

2017-06-01

Autophagy is a conserved cellular process for degrading aggregate proteins and dysfunctional organelle. It is still debatable if autophagy and mitophagy (a specific process of autophagy of mitochondria) play important roles in myogenic differentiation and functional regeneration of skeletal muscle. We tested the hypothesis that autophagy is critical for functional regeneration of skeletal muscle. We first observed time-dependent increases (3- to 6-fold) of autophagy-related proteins (Atgs), including Ulk1, Beclin1, and LC3, along with reduced p62 expression during C2C12 differentiation, suggesting increased autophagy capacity and flux during myogenic differentiation. We then used cardiotoxin (Ctx) or ischemia-reperfusion (I/R) to induce muscle injury and regeneration and observed increases in Atgs between days 2 and 7 in adult skeletal muscle followed by increased autophagy flux after day 7 Since Ulk1 has been shown to be essential for mitophagy, we asked if Ulk1 is critical for functional regeneration in skeletal muscle. We subjected skeletal muscle-specific Ulk1 knockout mice (MKO) to Ctx or I/R. MKO mice had significantly impaired recovery of muscle strength and mitochondrial protein content post-Ctx or I/R. Imaging analysis showed that MKO mice have significantly attenuated recovery of mitochondrial network at 7 and 14 days post-Ctx. These findings suggest that increased autophagy protein and flux occur during muscle regeneration and Ulk1-mediated mitophagy is critical for recovery for the mitochondrial network and hence functional regeneration. Copyright © 2017 the American Physiological Society.

Forced cell cycle exit and modulation of GABAA, CREB, and GSK3β signaling promote functional maturation of induced pluripotent stem cell-derived neurons.

PubMed

Telezhkin, Vsevolod; Schnell, Christian; Yarova, Polina; Yung, Sun; Cope, Emma; Hughes, Alis; Thompson, Belinda A; Sanders, Philip; Geater, Charlene; Hancock, Jane M; Joy, Shona; Badder, Luned; Connor-Robson, Natalie; Comella, Andrea; Straccia, Marco; Bombau, Georgina; Brown, Jon T; Canals, Josep M; Randall, Andrew D; Allen, Nicholas D; Kemp, Paul J

2016-04-01

Although numerous protocols have been developed for differentiation of neurons from a variety of pluripotent stem cells, most have concentrated on being able to specify effectively appropriate neuronal subtypes and few have been designed to enhance or accelerate functional maturity. Of those that have, most employ time courses of functional maturation that are rather protracted, and none have fully characterized all aspects of neuronal function, from spontaneous action potential generation through to postsynaptic receptor maturation. Here, we describe a simple protocol that employs the sequential addition of just two supplemented media that have been formulated to separate the two key phases of neural differentiation, the neurogenesis and synaptogenesis, each characterized by different signaling requirements. Employing these media, this new protocol synchronized neurogenesis and enhanced the rate of maturation of pluripotent stem cell-derived neural precursors. Neurons differentiated using this protocol exhibited large cell capacitance with relatively hyperpolarized resting membrane potentials; moreover, they exhibited augmented: 1) spontaneous electrical activity; 2) regenerative induced action potential train activity; 3) Na(+) current availability, and 4) synaptic currents. This was accomplished by rapid and uniform development of a mature, inhibitory GABAAreceptor phenotype that was demonstrated by Ca(2+) imaging and the ability of GABAAreceptor blockers to evoke seizurogenic network activity in multielectrode array recordings. Furthermore, since this protocol can exploit expanded and frozen prepatterned neural progenitors to deliver mature neurons within 21 days, it is both scalable and transferable to high-throughput platforms for the use in functional screens. Copyright © 2016 the American Physiological Society.

miRNAome expression profiles in the gonads of adult Melopsittacus undulatus

PubMed Central

Jiang, Lan; Wang, Qingqing; Yu, Jue; Gowda, Vinita; Johnson, Gabriel; Yang, Jianke

2018-01-01

The budgerigar (Melopsittacus undulatus) is one of the most widely studied parrot species, serving as an excellent animal model for behavior and neuroscience research. Until recently, it was unknown how sexual differences in the behavior, physiology, and development of organisms are regulated by differential gene expression. MicroRNAs (miRNAs) are endogenous short non-coding RNA molecules that can post-transcriptionally regulate gene expression and play a critical role in gonadal differentiation as well as early development of animals. However, very little is known about the role gonadal miRNAs play in the early development of birds. Research on the sex-biased expression of miRNAs in avian gonads are limited, and little is known about M. undulatus. In the current study, we sequenced two small non-coding RNA libraries made from the gonads of adult male and female budgerigars using Illumina paired-end sequencing technology. We obtained 254 known and 141 novel miRNAs, and randomly validated five miRNAs. Of these, three miRNAs were differentially expressed miRNAs and 18 miRNAs involved in sexual differentiation as determined by functional analysis with GO annotation and KEGG pathway analysis. In conclusion, this work is the first report of sex-biased miRNAs expression in the budgerigar, and provides additional sequences to the avian miRNAome database which will foster further functional genomic research. PMID:29666766

Whole-body scintigraphy with radioiodine-131. A comprehensive list of false-positives with some examples.

PubMed

McDougall, I R

1995-10-01

Whole-body scintigraphy with radioiodine-131 is an important diagnostic test in the management of patients with differentiated thyroid cancer who have undergone surgical treatment. The scan can demonstrate the presence of residual thyroid or functioning metastases in lymph nodes or distant sites. However, there are a number of potential pitfalls in the interpretation of this scan that could lead to a false-positive diagnosis of cancer. The scintiscans are presented for five patients in whom uptake outside of the thyroid was not due to functioning metastases. Some of these abnormalities are physiologic, such as uptake of iodine in the gastrointestinal tract. A comprehensive list of false-positive results are tabulated.

Assessment of heart rate variability based on mobile device for planning physical activity

NASA Astrophysics Data System (ADS)

Svirin, I. S.; Epishina, E. V.; Voronin, V. V.; Semenishchev, E. A.; Solodova, E. N.; Nabilskaya, N. V.

2015-05-01

In this paper we present a method for the functional analysis of human heart based on electrocardiography (ECG) signals. The approach using the apparatus of analytical and differential geometry and correlation and regression analysis. ECG contains information on the current condition of the cardiovascular system as well as on the pathological changes in the heart. Mathematical processing of the heart rate variability allows to obtain a great set of mathematical and statistical characteristics. These characteristics of the heart rate are used when solving research problems to study physiological changes that determine functional changes of an individual. The proposed method implemented for up-to-date mobile Android and iOS based devices.

Differentiation-dependent rearrangements of actin filaments and microtubules hinder apical endocytosis in urothelial cells.

PubMed

Tratnjek, Larisa; Romih, Rok; Kreft, Mateja Erdani

2017-08-01

During differentiation, superficial urothelial cells (UCs) of the urinary bladder form the apical surface, which is almost entirely covered by urothelial plaques containing densely packed uroplakin particles. These urothelial plaques are the main structural components of the blood-urine permeability barrier in the urinary bladder. We have shown previously that endocytosis from the apical plasma membrane decreases during urothelial cell differentiation. Here, we investigated the role of actin filament and microtubule rearrangements in apical endocytosis of differentiating UCs cells using hyperplastic and normoplastic porcine urothelial models. Partially differentiated normal porcine UCs contained actin filaments in the subapical cytoplasm, while microtubules had a net-like appearance. In highly differentiated UCs, actin filaments mostly disappeared from the subapical cytoplasm and microtubules remained as a thin layer close to the apical plasma membrane. Inhibition of actin filament formation with cytochalasin-D in partially differentiated UCs caused a decrease in apical endocytosis. Depolymerisation of microtubules with nocodazole did not prevent endocytosis of the endocytotic marker WGA into the subapical cytoplasm; however, it abolished WGA transport to endolysosomal compartments in the central cytoplasm. Cytochalasin-D or nocodazole treatment did not significantly change apical endocytosis in highly differentiated UCs. In conclusion, we showed that the physiological differentiation-dependent or chemically induced redistribution and reorganization of actin filaments and microtubules impair apical endocytosis in UCs. Importantly, reduced apical endocytosis due to cytoskeletal rearrangements in highly differentiated UCs, together with the formation of rigid urothelial plaques, reinforces the barrier function of the urothelium.

Role of growth differentiation factor 11 in development, physiology and disease

PubMed Central

Zhang, Yonghui; Wei, Yong; Liu, Dan; Liu, Feng; Li, Xiaoshan; Pan, Lianhong; Pang, Yi; Chen, Dilong

2017-01-01

Growth differentiation factor (GDF11) is a member of TGF-β/BMP superfamily that activates Smad and non-Smad signaling pathways and regulates expression of its target nuclear genes. Since its discovery in 1999, studies have shown the involvement of GDF11 in normal physiological processes, such as embryonic development and erythropoiesis, as well as in the pathophysiology of aging, cardiovascular disease, diabetes mellitus, and cancer. In addition, there are contradictory reports regarding the role of GDF11 in aging, cardiovascular disease, diabetes mellitus, osteogenesis, skeletal muscle development, and neurogenesis. In this review, we describe the GDF11 signaling pathway and its potential role in development, physiology and disease. PMID:29113418

Comparative Proteomic and Physiological Analysis Reveals the Variation Mechanisms of Leaf Coloration and Carbon Fixation in a Xantha Mutant of Ginkgo biloba L.

PubMed

Liu, Xinliang; Yu, Wanwen; Wang, Guibin; Cao, Fuliang; Cai, Jinfeng; Wang, Huanli

2016-10-27

Yellow-green leaf mutants are common in higher plants, and these non-lethal chlorophyll-deficient mutants are ideal materials for research on photosynthesis and plant development. A novel xantha mutant of Ginkgo biloba displaying yellow-colour leaves (YL) and green-colour leaves (GL) was identified in this study. The chlorophyll content of YL was remarkably lower than that in GL. The chloroplast ultrastructure revealed that YL had less dense thylakoid lamellae, a looser structure and fewer starch grains than GL. Analysis of the photosynthetic characteristics revealed that YL had decreased photosynthetic activity with significantly high nonphotochemical quenching. To explain these phenomena, we analysed the proteomic differences in leaves and chloroplasts between YL and GL of ginkgo using two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF/TOF MS. In total, 89 differential proteins were successfully identified, 82 of which were assigned functions in nine metabolic pathways and cellular processes. Among them, proteins involved in photosynthesis, carbon fixation in photosynthetic organisms, carbohydrate/energy metabolism, amino acid metabolism, and protein metabolism were greatly enriched, indicating a good correlation between differentially accumulated proteins and physiological changes in leaves. The identifications of these differentially accumulated proteins indicates the presence of a specific different metabolic network in YL and suggests that YL possess slower chloroplast development, weaker photosynthesis, and a less abundant energy supply than GL. These studies provide insights into the mechanism of molecular regulation of leaf colour variation in YL mutants.

Statistical Analysis of 3D Images Detects Regular Spatial Distributions of Centromeres and Chromocenters in Animal and Plant Nuclei

PubMed Central

Biot, Eric; Adenot, Pierre-Gaël; Hue-Beauvais, Cathy; Houba-Hérin, Nicole; Duranthon, Véronique; Devinoy, Eve; Beaujean, Nathalie; Gaudin, Valérie; Maurin, Yves; Debey, Pascale

2010-01-01

In eukaryotes, the interphase nucleus is organized in morphologically and/or functionally distinct nuclear “compartments”. Numerous studies highlight functional relationships between the spatial organization of the nucleus and gene regulation. This raises the question of whether nuclear organization principles exist and, if so, whether they are identical in the animal and plant kingdoms. We addressed this issue through the investigation of the three-dimensional distribution of the centromeres and chromocenters. We investigated five very diverse populations of interphase nuclei at different differentiation stages in their physiological environment, belonging to rabbit embryos at the 8-cell and blastocyst stages, differentiated rabbit mammary epithelial cells during lactation, and differentiated cells of Arabidopsis thaliana plantlets. We developed new tools based on the processing of confocal images and a new statistical approach based on G- and F- distance functions used in spatial statistics. Our original computational scheme takes into account both size and shape variability by comparing, for each nucleus, the observed distribution against a reference distribution estimated by Monte-Carlo sampling over the same nucleus. This implicit normalization allowed similar data processing and extraction of rules in the five differentiated nuclei populations of the three studied biological systems, despite differences in chromosome number, genome organization and heterochromatin content. We showed that centromeres/chromocenters form significantly more regularly spaced patterns than expected under a completely random situation, suggesting that repulsive constraints or spatial inhomogeneities underlay the spatial organization of heterochromatic compartments. The proposed technique should be useful for identifying further spatial features in a wide range of cell types. PMID:20628576

Hyaluronan Does Not Regulate Human Epidermal Keratinocyte Proliferation and Differentiation*

PubMed Central

Malaisse, Jérémy; Pendaries, Valérie; Hontoir, Fanny; De Glas, Valérie; Van Vlaender, Daniel; Simon, Michel; Lambert de Rouvroit, Catherine; Poumay, Yves; Flamion, Bruno

2016-01-01

Hyaluronan (HA) is synthesized by three HA synthases (HAS1, HAS2, and HAS3) and secreted in the extracellular matrix. In human skin, large amounts of HA are found in the dermis. HA is also synthesized by keratinocytes in the epidermis, although its epidermal functions are not clearly identified yet. To investigate HA functions, we studied the effects of HA depletion on human keratinocyte physiology within in vitro reconstructed human epidermis. Inhibition of HA synthesis with 4-methylumbelliferone (4MU) did not modify the expression profile of the epidermal differentiation markers involucrin, keratin 10, and filaggrin during tissue reconstruction. In contrast, when keratinocytes were incubated with 4MU, cell proliferation was decreased. In an attempt to rescue the proliferation function, HA samples of various mean molecular masses were added to keratinocyte cultures treated with 4MU. These samples were unable to rescue the initial proliferation rate. Furthermore, treatments with HA-specific hyaluronidase, although removing almost all HA from keratinocyte cultures, did not alter the differentiation or proliferation processes. The differences between 4MU and hyaluronidase effects did not result from differences in intracellular HA, sulfated glycosaminoglycan concentration, apoptosis, or levels of HA receptors, all of which remained unchanged. Similarly, knockdown of UDP-glucose 6-dehydrogenase (UGDH) using lentiviral shRNA effectively decreased HA production but did not affect proliferation rate. Overall, these data suggest that HA levels in the human epidermis are not directly correlated with keratinocyte proliferation and differentiation and that incubation of cells with 4MU cannot equate with HA removal. PMID:26627828

The role of TREX in gene expression and disease

PubMed Central

Heath, Catherine G.; Viphakone, Nicolas; Wilson, Stuart A.

2016-01-01

TRanscription and EXport (TREX) is a conserved multisubunit complex essential for embryogenesis, organogenesis and cellular differentiation throughout life. By linking transcription, mRNA processing and export together, it exerts a physiologically vital role in the gene expression pathway. In addition, this complex prevents DNA damage and regulates the cell cycle by ensuring optimal gene expression. As the extent of TREX activity in viral infections, amyotrophic lateral sclerosis and cancer emerges, the need for a greater understanding of TREX function becomes evident. A complete elucidation of the composition, function and interactions of the complex will provide the framework for understanding the molecular basis for a variety of diseases. This review details the known composition of TREX, how it is regulated and its cellular functions with an emphasis on mammalian systems. PMID:27679854

Generation of functional cardiomyocytes from rat embryonic and induced pluripotent stem cells using feeder-free expansion and differentiation in suspension culture.

PubMed

Dahlmann, Julia; Awad, George; Dolny, Carsten; Weinert, Sönke; Richter, Karin; Fischer, Klaus-Dieter; Munsch, Thomas; Leßmann, Volkmar; Volleth, Marianne; Zenker, Martin; Chen, Yaoyao; Merkl, Claudia; Schnieke, Angelika; Baraki, Hassina; Kutschka, Ingo; Kensah, George

2018-01-01

The possibility to generate cardiomyocytes from pluripotent stem cells in vitro has enormous significance for basic research, disease modeling, drug development and heart repair. The concept of heart muscle reconstruction has been studied and optimized in the rat model using rat primary cardiovascular cells or xenogeneic pluripotent stem cell derived-cardiomyocytes for years. However, the lack of rat pluripotent stem cells (rPSCs) and their cardiovascular derivatives prevented the establishment of an authentic clinically relevant syngeneic or allogeneic rat heart regeneration model. In this study, we comparatively explored the potential of recently available rat embryonic stem cells (rESCs) and induced pluripotent stem cells (riPSCs) as a source for cardiomyocytes (CMs). We developed feeder cell-free culture conditions facilitating the expansion of undifferentiated rPSCs and initiated cardiac differentiation by embryoid body (EB)-formation in agarose microwell arrays, which substituted the robust but labor-intensive hanging drop (HD) method. Ascorbic acid was identified as an efficient enhancer of cardiac differentiation in both rPSC types by significantly increasing the number of beating EBs (3.6 ± 1.6-fold for rESCs and 17.6 ± 3.2-fold for riPSCs). These optimizations resulted in a differentiation efficiency of up to 20% cTnTpos rPSC-derived CMs. CMs showed spontaneous contractions, expressed cardiac markers and had typical morphological features. Electrophysiology of riPSC-CMs revealed different cardiac subtypes and physiological responses to cardio-active drugs. In conclusion, we describe rPSCs as a robust source of CMs, which is a prerequisite for detailed preclinical studies of myocardial reconstruction in a physiologically and immunologically relevant small animal model.

Vesicular glutamate transporters play a role in neuronal differentiation of cultured SVZ-derived neural precursor cells

PubMed Central

Sánchez-Mendoza, Eduardo H.; Bellver-Landete, Victor; Arce, Carmen; Doeppner, Thorsten R.; Hermann, Dirk M.

2017-01-01

The role of glutamate in the regulation of neurogenesis is well-established, but the role of vesicular glutamate transporters (VGLUTs) and excitatory amino acid transporters (EAATs) in controlling adult neurogenesis is unknown. Here we investigated the implication of VGLUTs in the differentiation of subventricular zone (SVZ)-derived neural precursor cells (NPCs). Our results show that NPCs express VGLUT1-3 and EAAT1-3 both at the mRNA and protein level. Their expression increases during differentiation closely associated with the expression of marker genes. In expression analyses we show that VGLUT1 and VGLUT2 are preferentially expressed by cultured SVZ-derived doublecortin+ neuroblasts, while VGLUT3 is found on GFAP+ glial cells. In cultured NPCs, inhibition of VGLUT by Evans Blue increased the mRNA level of neuronal markers doublecortin, B3T and MAP2, elevated the number of NPCs expressing doublecortin protein and promoted the number of cells with morphological appearance of branched neurons, suggesting that VGLUT function prevents neuronal differentiation of NPCs. This survival- and differentiation-promoting effect of Evans blue was corroborated by increased AKT phosphorylation and reduced MAPK phosphorylation. Thus, under physiological conditions, VGLUT1-3 inhibition, and thus decreased glutamate exocytosis, may promote neuronal differentiation of NPCs. PMID:28493916

Differential expression profiles and pathways of genes in sugarcane leaf at elongation stage in response to drought stress

PubMed Central

Li, Changning; Nong, Qian; Solanki, Manoj Kumar; Liang, Qiang; Xie, Jinlan; Liu, Xiaoyan; Li, Yijie; Wang, Weizan; Yang, Litao; Li, Yangrui

2016-01-01

Water stress causes considerable yield losses in sugarcane. To investigate differentially expressed genes under water stress, a pot experiment was performed with the sugarcane variety GT21 at three water-deficit levels (mild, moderate, and severe) during the elongation stage and gene expression was analyzed using microarray technology. Physiological parameters of sugarcane showed significant alterations in response to drought stress. Based on the expression profile of 15,593 sugarcane genes, 1,501 (9.6%) genes were differentially expressed under different water-level treatments; 821 genes were upregulated and 680 genes were downregulated. A gene similarity analysis showed that approximately 62.6% of the differentially expressed genes shared homology with functional proteins. In a Gene Ontology (GO) analysis, 901 differentially expressed genes were assigned to 36 GO categories. Moreover, 325 differentially expressed genes were classified into 101 pathway categories involved in various processes, such as the biosynthesis of secondary metabolites, ribosomes, carbon metabolism, etc. In addition, some unannotated genes were detected; these may provide a basis for studies of water-deficit tolerance. The reliability of the observed expression patterns was confirmed by RT-PCR. The results of this study may help identify useful genes for improving drought tolerance in sugarcane. PMID:27170459

Roles and regulations of the ETS transcription factor ELF4/MEF

PubMed Central

Suico, Mary Ann; Shuto, Tsuyoshi; Kai, Hirofumi

2017-01-01

Abstract Most E26 transformation-specific (ETS) transcription factors are involved in the pathogenesis and progression of cancer. This is in part due to the roles of ETS transcription factors in basic biological processes such as growth, proliferation, and differentiation, and also because of their regulatory functions that have physiological relevance in tumorigenesis, immunity, and basal cellular homoeostasis. A member of the E74-like factor (ELF) subfamily of the ETS transcription factor family—myeloid elf-1-like factor (MEF), designated as ELF4—has been shown to be critically involved in immune response and signalling, osteogenesis, adipogenesis, cancer, and stem cell quiescence. ELF4 carries out these functions as a transcriptional activator or through interactions with its partner proteins. Mutations in ELF4 cause aberrant interactions and induce downstream processes that may lead to diseased cells. Knowing how ELF4 impinges on certain cellular processes and how it is regulated in the cells can lead to a better understanding of the physiological and pathological consequences of modulated ELF4 activity. PMID:27932483

Mammalian lipoxygenases and their biological relevance.

PubMed

Kuhn, Hartmut; Banthiya, Swathi; van Leyen, Klaus

2015-04-01

Lipoxygenases (LOXs) form a heterogeneous class of lipid peroxidizing enzymes, which have been implicated not only in cell proliferation and differentiation but also in the pathogenesis of various diseases with major public health relevance. As other fatty acid dioxygenases LOXs oxidize polyunsaturated fatty acids to their corresponding hydroperoxy derivatives, which are further transformed to bioactive lipid mediators (eicosanoids and related substances). On the other hand, lipoxygenases are key players in the regulation of the cellular redox homeostasis, which is an important element in gene expression regulation. Although the first mammalian lipoxygenases were discovered 40 years ago and although the enzymes have been well characterized with respect to their structural and functional properties the biological roles of the different lipoxygenase isoforms are not completely understood. This review is aimed at summarizing the current knowledge on the physiological roles of different mammalian LOX-isoforms and their patho-physiological function in inflammatory, metabolic, hyperproliferative, neurodegenerative and infectious disorders. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance". Copyright © 2014 Elsevier B.V. All rights reserved.

Modulation of low-voltage-activated T-type Ca²⁺ channels.

PubMed

Zhang, Yuan; Jiang, Xinghong; Snutch, Terrance P; Tao, Jin

2013-07-01

Low-voltage-activated T-type Ca²⁺ channels contribute to a wide variety of physiological functions, most predominantly in the nervous, cardiovascular and endocrine systems. Studies have documented the roles of T-type channels in sleep, neuropathic pain, absence epilepsy, cell proliferation and cardiovascular function. Importantly, novel aspects of the modulation of T-type channels have been identified over the last few years, providing new insights into their physiological and pathophysiological roles. Although there is substantial literature regarding modulation of native T-type channels, the underlying molecular mechanisms have only recently begun to be addressed. This review focuses on recent evidence that the Ca(v)3 subunits of T-type channels, Ca(v)3.1, Ca(v)3.2 and Ca(v)3.3, are differentially modulated by a multitude of endogenous ligands including anandamide, monocyte chemoattractant protein-1, endostatin, and redox and oxidizing agents. The review also provides an overview of recent knowledge gained concerning downstream pathways involving G-protein-coupled receptors. This article is part of a Special Issue entitled: Calcium channels. Copyright © 2012 Elsevier B.V. All rights reserved.

Evidence for biochemical and physiological differences between enzyme genotypes in Drosophila melanogaster.

PubMed Central

Cavener, D R; Clegg, M T

1981-01-01

The in vivo flux of carbon through the pentose shunt is investigated as a function of different 6-phosphogluconate dehydrogenase (6Pgd) and glucose-6-phosphate dehydrogenase (G6pd) genotypes by using differential radioactive labeling of the C-1 and C-6 positions of glucose. Alternative 6Pgd-G6pd genotypes are shown to differ in relative in vivo carbon flux through the pentose shunt. The relative in vitro specific activity differences between the 6PgdSS and 6PgdFF genotypes appear to be primarily responsible for these differences. In addition, the pentose-shunt activity is correlated with the rate of lipid synthesis. This correlation is consistent with the major metabolic function of the pathway, which is to produce NADPH for lipid synthesis. Taken together, the results of these experiments show that different genotypes of 6Pgd are associated with measurable biochemical and physiological differences. Higher order phenotypic differences of this kind must be demonstrated to support the hypothesis that natural selection can discriminate among allozymes of a given genetic locus. PMID:6794031

¹H, ¹³C and ¹⁵N resonance assignment for the human K-Ras at physiological pH.

PubMed

Vo, Uybach; Embrey, Kevin J; Breeze, Alexander L; Golovanov, Alexander P

2013-10-01

K-Ras, a member of the Ras family of small GTPases, is involved in cell growth, proliferation, differentiation and apoptosis and is frequently mutated in cancer. The activity of Ras is mediated by the inter-conversion between GTP- and GDP- bound states. This conversion is regulated by binding of effector proteins such as guanine nucleotide exchange factors and GTPase activating proteins. Previously, NMR signals from these effector-binding regions of Ras often remained unassigned and largely unobservable due to conformational exchange and polysterism inherent to this protein. In this paper, we report the complete backbone and C(β), as well as partial H(α), H(β) and C(γ), NMR assignment for human K-Ras (residues 1-166) in the GDP-bound form at a physiological pH of 7.4. These data thereby make possible detailed monitoring of the functional cycle of Ras and its interactions with nucleotides and effector proteins through the observation of fingerprint signals from all the functionally important regions of the protein.

Quantitative analysis of random ameboid motion

NASA Astrophysics Data System (ADS)

Bödeker, H. U.; Beta, C.; Frank, T. D.; Bodenschatz, E.

2010-04-01

We quantify random migration of the social ameba Dictyostelium discoideum. We demonstrate that the statistics of cell motion can be described by an underlying Langevin-type stochastic differential equation. An analytic expression for the velocity distribution function is derived. The separation into deterministic and stochastic parts of the movement shows that the cells undergo a damped motion with multiplicative noise. Both contributions to the dynamics display a distinct response to external physiological stimuli. The deterministic component depends on the developmental state and ambient levels of signaling substances, while the stochastic part does not.

[Cardiac rhythm variability as an index of vegetative heart regulation in a situation of psychoemotional tension].

PubMed

Revina, N E

2006-01-01

Differentiated role of segmental and suprasegmental levels of cardiac rhythm variability regulation in dynamics of motivational human conflict was studied for the first time. The author used an original method allowing simultaneous analysis of psychological and physiological parameters of human activity. The study demonstrates that will and anxiety, as components of motivational activity spectrum, form the "energetic" basis of voluntary-constructive and involuntary-affective behavioral strategies, selectively uniting various levels of suprasegmental and segmental control of human heart functioning in a conflict situation.

Genetic and pharmacological analysis identifies a physiological role for the AHR in epidermal differentiation

PubMed Central

van den Bogaard, Ellen; Podolsky, Michael; Smits, Jos; Cui, Xiao; John, Christian; Gowda, Krishne; Desai, Dhimant; Amin, Shantu; Schalkwijk, Joost; Perdew, Gary H.

2015-01-01

Stimulation of the aryl hydrocarbon receptor (AHR) by xenobiotics is known to affect epidermal differentiation and skin barrier formation. The physiological role of endogenous AHR signaling in keratinocyte differentiation is not known. We used murine and human skin models to address the hypothesis that AHR activation is required for normal keratinocyte differentiation. Using transcriptome analysis of Ahr-/- and Ahr+/+ murine keratinocytes, we found significant enrichment of differentially expressed genes linked to epidermal differentiation. Primary Ahr-/- keratinocytes showed a significant reduction in terminal differentiation gene and protein expression, similar to Ahr+/+ keratinocytes treated with AHR antagonists GNF351 and CH223191, or the selective AHR modulator (SAhRM), SGA360. In vitro keratinocyte differentiation led to increased AHR levels and subsequent nuclear translocation, followed by induced CYP1A1 gene expression. Monolayer cultured primary human keratinocytes treated with AHR antagonists also showed an impaired terminal differentiation program. Inactivation of AHR activity during human skin equivalent development severely impaired epidermal stratification, terminal differentiation protein expression and stratum corneum formation. As disturbed epidermal differentiation is a main feature of many skin diseases, pharmacological agents targeting AHR signaling or future identification of endogenous keratinocyte-derived AHR ligands should be considered as potential new drugs in dermatology. PMID:25602157

Functional Peptidomics: Stimulus- and Time-of-Day-Specific Peptide Release in the Mammalian Circadian Clock.

PubMed

Atkins, Norman; Ren, Shifang; Hatcher, Nathan; Burgoon, Penny W; Mitchell, Jennifer W; Sweedler, Jonathan V; Gillette, Martha U

2018-06-20

Daily oscillations of brain and body states are under complex temporal modulation by environmental light and the hypothalamic suprachiasmatic nucleus (SCN), the master circadian clock. To better understand mediators of differential temporal modulation, we characterize neuropeptide releasate profiles by nonselective capture of secreted neuropeptides in an optic nerve horizontal SCN brain slice model. Releasates are collected following electrophysiological stimulation of the optic nerve/retinohypothalamic tract under conditions that alter the phase of the SCN activity state. Secreted neuropeptides are identified by intact mass via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We found time-of-day-specific suites of peptides released downstream of optic nerve stimulation. Peptide release was modified differentially with respect to time-of-day by stimulus parameters and by inhibitors of glutamatergic or PACAPergic neurotransmission. The results suggest that SCN physiology is modulated by differential peptide release of both known and unexpected peptides that communicate time-of-day-specific photic signals via previously unreported neuropeptide signatures.

Differential TAM receptor-ligand-phospholipid interactions delimit differential TAM bioactivities.

PubMed

Lew, Erin D; Oh, Jennifer; Burrola, Patrick G; Lax, Irit; Zagórska, Anna; Través, Paqui G; Schlessinger, Joseph; Lemke, Greg

2014-09-29

The TAM receptor tyrosine kinases Tyro3, Axl, and Mer regulate key features of cellular physiology, yet the differential activities of the TAM ligands Gas6 and Protein S are poorly understood. We have used biochemical and genetic analyses to delineate the rules for TAM receptor-ligand engagement and find that the TAMs segregate into two groups based on ligand specificity, regulation by phosphatidylserine, and function. Tyro3 and Mer are activated by both ligands but only Gas6 activates Axl. Optimal TAM signaling requires coincident TAM ligand engagement of both its receptor and the phospholipid phosphatidylserine (PtdSer): Gas6 lacking its PtdSer-binding 'Gla domain' is significantly weakened as a Tyro3/Mer agonist and is inert as an Axl agonist, even though it binds to Axl with wild-type affinity. In two settings of TAM-dependent homeostatic phagocytosis, Mer plays a predominant role while Axl is dispensable, and activation of Mer by Protein S is sufficient to drive phagocytosis.

Intracellular calcium levels determine differential modulation of allosteric interactions within G protein-coupled receptor heteromers.

PubMed

Navarro, Gemma; Aguinaga, David; Moreno, Estefania; Hradsky, Johannes; Reddy, Pasham P; Cortés, Antoni; Mallol, Josefa; Casadó, Vicent; Mikhaylova, Marina; Kreutz, Michael R; Lluís, Carme; Canela, Enric I; McCormick, Peter J; Ferré, Sergi

2014-11-20

The pharmacological significance of the adenosine A2A receptor (A2AR)-dopamine D2 receptor (D2R) heteromer is well established and it is being considered as an important target for the treatment of Parkinson’s disease and other neuropsychiatric disorders. However, the physiological factors that control its distinctive biochemical properties are still unknown. We demonstrate that different intracellular Ca2+ levels exert a differential modulation of A2AR-D2R heteromer-mediated adenylyl-cyclase and MAPK signaling in striatal cells. This depends on the ability of low and high Ca2+ levels to promote a selective interaction of the heteromer with the neuronal Ca2+-binding proteins NCS-1 and calneuron-1, respectively. These Ca2+-binding proteins differentially modulate allosteric interactions within the A2AR-D2R heteromer, which constitutes a unique cellular device that integrates extracellular (adenosine and dopamine) and intracellular (Ca+2) signals to produce a specific functional response.

Ex vivo gut culture for studying differentiation and migration of small intestinal epithelial cells

PubMed Central

Fu, Xing; Du, Min

2018-01-01

Epithelial cultures are commonly used for studying gut health. However, due to the absence of mesenchymal cells and gut structure, epithelial culture systems including recently developed three-dimensional organoid culture cannot accurately represent in vivo gut development, which requires intense cross-regulation of the epithelial layer with the underlying mesenchymal tissue. In addition, organoid culture is costly. To overcome this, a new culture system was developed using mouse embryonic small intestine. Cultured intestine showed spontaneous peristalsis, indicating the maintenance of the normal gut physiological structure. During 10 days of ex vivo culture, epithelial cells moved along the gut surface and differentiated into different epithelial cell types, including enterocytes, Paneth cells, goblet cells and enteroendocrine cells. We further used the established ex vivo system to examine the role of AMP-activated protein kinase (AMPK) on gut epithelial health. Tamoxifen-induced AMPKα1 knockout vastly impaired epithelial migration and differentiation of the developing ex vivo gut, showing the crucial regulatory function of AMPK α1 in intestinal health. PMID:29643147

Dendrogenin A arises from cholesterol and histamine metabolism and shows cell differentiation and anti-tumour properties.

PubMed

de Medina, Philippe; Paillasse, Michael R; Segala, Gregory; Voisin, Maud; Mhamdi, Loubna; Dalenc, Florence; Lacroix-Triki, Magali; Filleron, Thomas; Pont, Frederic; Saati, Talal Al; Morisseau, Christophe; Hammock, Bruce D; Silvente-Poirot, Sandrine; Poirot, Marc

2013-01-01

We previously synthesized dendrogenin A and hypothesized that it could be a natural metabolite occurring in mammals. Here we explore this hypothesis and report the discovery of dendrogenin A in mammalian tissues and normal cells as an enzymatic product of the conjugation of 5,6α-epoxy-cholesterol and histamine. Dendrogenin A was not detected in cancer cell lines and was fivefold lower in human breast tumours compared with normal tissues, suggesting a deregulation of dendrogenin A metabolism during carcinogenesis. We established that dendrogenin A is a selective inhibitor of cholesterol epoxide hydrolase and it triggered tumour re-differentiation and growth control in mice and improved animal survival. The properties of dendrogenin A and its decreased level in tumours suggest a physiological function in maintaining cell integrity and differentiation. The discovery of dendrogenin A reveals a new metabolic pathway at the crossroads of cholesterol and histamine metabolism and the existence of steroidal alkaloids in mammals.

Expression of Ambra1 in mouse brain during physiological and Alzheimer type aging.

PubMed

Sepe, Sara; Nardacci, Roberta; Fanelli, Francesca; Rosso, Pamela; Bernardi, Cinzia; Cecconi, Francesco; Mastroberardino, Pier G; Piacentini, Mauro; Moreno, Sandra

2014-01-01

Autophagy is a major protein degradation pathway, essential for stress-induced and constitutive protein turnover. In nervous tissue, autophagy is constitutively active and crucial to neuronal survival. The efficiency of the autophagic pathway reportedly undergoes age-related decline, and autophagy defects are observed in neurodegenerative diseases. Since Ambra1 plays a fundamental role in regulating the autophagic process in developing nervous tissue, we investigated the expression of this protein in mature mouse brain and during physiological and Alzheimer type aging. The present study accomplished the first complete map of Ambra1 protein distribution in the various brain areas, and highlights differential expression in neuronal/glial cell populations. Differences in Ambra1 content are possibly related to specific neuronal features and properties, particularly concerning susceptibility to neurodegeneration. Furthermore, the analysis of Ambra1 expression in physiological and pathological brain aging supports important, though conflicting, functions of autophagy in neurodegenerative processes. Thus, novel therapeutic approaches, based on autophagy modulation, should also take into account the age-dependent roles of this mechanism in establishing, promoting, or counteracting neurodegeneration. Copyright © 2014 Elsevier Inc. All rights reserved.

Hop (Humulus lupulus L.) response mechanisms in drought stress: Proteomic analysis with physiology.

PubMed

Kolenc, Zala; Vodnik, Dominik; Mandelc, Stanislav; Javornik, Branka; Kastelec, Damijana; Čerenak, Andreja

2016-08-01

Drought is one of the major environmental devastating stressors that impair the growth and productivity of crop plants. Despite the relevance of drought stress, changes in physiology and resistance mechanisms are not completely understood for certain crops, including hop (Humulus lupulus L.). In this research the drought response of hop was studied using a conventional physiological approach (gas exchange techniques, fluorescence, relative water content measurements) and proteomic analysis (2D-DIGE). Plants of two cultivars (Aurora and Savinjski golding) were exposed to progressive drought in a pot experiment and analysed at different stress stages (mild, moderate and severe). Measurements of relative water content revealed a hydrostable water balance of hop. Photosynthesis was decreased due to stomatal and non-stomatal limitation to the same extent in both cultivars. Of 28 identified differentially abundant proteins, the majority were down regulated and included in photosynthetic (41%) and sugar metabolism (33%). Fifteen % of identified proteins were classified into the nitrogen metabolism, 4% were related to a ROS related pathway and 7% to other functions. Copyright © 2016. Published by Elsevier Masson SAS.

Characterization of Human Hippocampal Neural Stem/Progenitor Cells and Their Application to Physiologically Relevant Assays for Multiple Ionotropic Glutamate Receptors.

PubMed

Fukushima, Kazuyuki; Tabata, Yoshikuni; Imaizumi, Yoichi; Kohmura, Naohiro; Sugawara, Michiko; Sawada, Kohei; Yamazaki, Kazuto; Ito, Masashi

2014-09-01

The hippocampus is an important brain region that is involved in neurological disorders such as Alzheimer disease, schizophrenia, and epilepsy. Ionotropic glutamate receptors-namely,N-methyl-D-aspartate (NMDA) receptors (NMDARs), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors (AMPARs), and kainic acid (KA) receptors (KARs)-are well known to be involved in these diseases by mediating long-term potentiation, excitotoxicity, or both. To predict the therapeutic efficacy and neuronal toxicity of drug candidates acting on these receptors, physiologically relevant systems for assaying brain region-specific human neural cells are necessary. Here, we characterized the functional differentiation of human fetal hippocampus-derived neural stem/progenitor cells-namely, HIP-009 cells. Calcium rise assay demonstrated that, after a 4-week differentiation, the cells responded to NMDA (EC50= 7.5 ± 0.4 µM; n= 4), AMPA (EC50= 2.5 ± 0.1 µM; n= 3), or KA (EC50= 33.5 ± 1.1 µM; n= 3) in a concentration-dependent manner. An AMPA-evoked calcium rise was observed in the absence of the desensitization inhibitor cyclothiazide. In addition, the calcium rise induced by these agonists was inhibited by antagonists for each receptor-namely, MK-801 for NMDA stimulation (IC50= 0.6 ± 0.1 µM; n= 4) and NBQX for AMPA and KA stimulation (IC50= 0.7 ± 0.1 and 0.7 ± 0.03 µM, respectively; n= 3). The gene expression profile of differentiated HIP-009 cells was distinct from that of undifferentiated cells and closely resembled that of the human adult hippocampus. Our results show that HIP-009 cells are a unique tool for obtaining human hippocampal neural cells and are applicable to systems for assay of ionotropic glutamate receptors as a physiologically relevant in vitro model. © 2014 Society for Laboratory Automation and Screening.

Optical Electrophysiology in the Developing Heart.

PubMed

Thomas, Kandace; Goudy, Julie; Henley, Trevor; Bressan, Michael

2018-05-11

The heart is the first organ system to form in the embryo. Over the course of development, cardiomyocytes with differing morphogenetic, molecular, and physiological characteristics are specified and differentiate and integrate with one another to assemble a coordinated electromechanical pumping system that can function independently of any external stimulus. As congenital malformation of the heart presents the leading class of birth defects seen in humans, the molecular genetics of heart development have garnered much attention over the last half century. However, understanding how genetic perturbations manifest at the level of the individual cell function remains challenging to investigate. Some of the barriers that have limited our capacity to construct high-resolution, comprehensive models of cardiac physiological maturation are rapidly being removed by advancements in the reagents and instrumentation available for high-speed live imaging. In this review, we briefly introduce the history of imaging approaches for assessing cardiac development, describe some of the reagents and tools required to perform live imaging in the developing heart, and discuss how the combination of modern imaging modalities and physiological probes can be used to scale from subcellular to whole-organ analysis. Through these types of imaging approaches, critical insights into the processes of cardiac physiological development can be directly examined in real-time. Moving forward, the synthesis of modern molecular biology and imaging approaches will open novel avenues to investigate the mechanisms of cardiomyocyte maturation, providing insight into the etiology of congenital heart defects, as well as serving to direct approaches for designing stem-cell or regenerative medicine protocols for clinical application.

Biological and medical applications of a brain-on-a-chip

PubMed Central

2016-01-01

The desire to develop and evaluate drugs as potential countermeasures for biological and chemical threats requires test systems that can also substitute for the clinical trials normally crucial for drug development. Current animal models have limited predictivity for drug efficacy in humans as the large majority of drugs fails in clinical trials. We have limited understanding of the function of the central nervous system and the complexity of the brain, especially during development and neuronal plasticity. Simple in vitro systems do not represent physiology and function of the brain. Moreover, the difficulty of studying interactions between human genetics and environmental factors leads to lack of knowledge about the events that induce neurological diseases. Microphysiological systems (MPS) promise to generate more complex in vitro human models that better simulate the organ’s biology and function. MPS combine different cell types in a specific three-dimensional (3D) configuration to simulate organs with a concrete function. The final aim of these MPS is to combine different “organoids” to generate a human-on-a-chip, an approach that would allow studies of complex physiological organ interactions. The recent discovery of induced pluripotent stem cells (iPSCs) gives a range of possibilities allowing cellular studies of individuals with different genetic backgrounds (e.g., human disease models). Application of iPSCs from different donors in MPS gives the opportunity to better understand mechanisms of the disease and can be a novel tool in drug development, toxicology, and medicine. In order to generate a brain-on-a-chip, we have established a 3D model from human iPSCs based on our experience with a 3D rat primary aggregating brain model. After four weeks of differentiation, human 3D aggregates stain positive for different neuronal markers and show higher gene expression of various neuronal differentiation markers compared to 2D cultures. Here we present the applications and challenges of this emerging technology. PMID:24912505

Synergistic roles of bone morphogenetic protein 15 and growth differentiation factor 9 in ovarian function.

PubMed

Yan, C; Wang, P; DeMayo, J; DeMayo, F J; Elvin, J A; Carino, C; Prasad, S V; Skinner, S S; Dunbar, B S; Dube, J L; Celeste, A J; Matzuk, M M

2001-06-01

Knockout mouse technology has been used over the last decade to define the essential roles of ovarian-expressed genes and uncover genetic interactions. In particular, we have used this technology to study the function of multiple members of the transforming growth factor-beta superfamily including inhibins, activins, and growth differentiation factor 9 (GDF-9 or Gdf9). Knockout mice lacking GDF-9 are infertile due to a block in folliculogenesis at the primary follicle stage. In addition, recombinant GDF-9 regulates multiple cumulus granulosa cell functions in the periovulatory period including hyaluronic acid synthesis and cumulus expansion. We have also cloned an oocyte-specific homolog of GDF-9 from mice and humans, which is termed bone morphogenetic protein 15 (BMP-15 or Bmp15). To define the function of BMP-15 in mice, we generated embryonic stem cells and knockout mice, which have a null mutation in this X-linked gene. Male chimeric and Bmp15 null mice are normal and fertile. In contrast to Bmp15 null males and Gdf9 knockout females, Bmp15 null females (Bmp15(-/-)) are subfertile and usually have minimal ovarian histopathological defects, but demonstrate decreased ovulation and fertilization rates. To further decipher possible direct or indirect genetic interactions between GDF-9 and BMP-15, we have generated double mutant mice lacking one or both alleles of these related homologs. Double homozygote females (Bmp15(-/-)Gdf9(-/-)) display oocyte loss and cysts and resemble Gdf9(-/-) mutants. In contrast, Bmp15(-/-)Gdf9(+/-) female mice have more severe fertility defects than Bmp15(-/-) females, which appear to be due to abnormalities in ovarian folliculogenesis, cumulus cell physiology, and fertilization. Thus, the dosage of intact Bmp15 and Gdf9 alleles directly influences the destiny of the oocyte during folliculogenesis and in the periovulatory period. These studies have important implications for human fertility control and the maintenance of fertility and normal ovarian physiology.

Cellular Responses to Mechanical Stress Selected Contribution: A Three-Dimensional Model for Assessment of in Vitro Toxicity in Balaena Mysticetus Renal Tissue

NASA Technical Reports Server (NTRS)

Goodwin, T. J.; Coate-Li, L.; Linnehan, R. M.; Hammond, T. G.

2000-01-01

This study established two- and three-dimensional renal proximal tubular cell cultures of the endangered species bowhead whale (Balaena mysticetus), developed SV40-transfected cultures, and cloned the 61-amino acid open reading frame for the metallothionein protein, the primary binding site for heavy metal contamination in mammals. Microgravity research, modulations in mechanical culture conditions (modeled microgravity), and shear stress have spawned innovative approaches to understanding the dynamics of cellular interactions, gene expression, and differentiation in several cellular systems. These investigations have led to the creation of ex vivo tissue models capable of serving as physiological research analogs for three-dimensional cellular interactions. These models are enabling studies in immune function, tissue modeling for basic research, and neoplasia. Three-dimensional cellular models emulate aspects of in vivo cellular architecture and physiology and may facilitate environmental toxicological studies aimed at elucidating biological functions and responses at the cellular level. Marine mammals occupy a significant ecological niche (72% of the Earth's surface is water) in terms of the potential for information on bioaccumulation and transport of terrestrial and marine environmental toxins in high-order vertebrates. Few ex vivo models of marine mammal physiology exist in vitro to accomplish the aforementioned studies. Techniques developed in this investigation, based on previous tissue modeling successes, may serve to facilitate similar research in other marine mammals.

Sex-Specific Effects of Combined Exposure to Chemical and Non-chemical Stressors on Neuroendocrine Development: a Review of Recent Findings and Putative Mechanisms.

PubMed

Cowell, Whitney J; Wright, Rosalind J

2017-12-01

Environmental toxicants and psychosocial stressors share many biological substrates and influence overlapping physiological pathways. Increasing evidence indicates stress-induced changes to the maternal milieu may prime rapidly developing physiological systems for disruption by concurrent or subsequent exposure to environmental chemicals. In this review, we highlight putative mechanisms underlying sex-specific susceptibility of the developing neuroendocrine system to the joint effects of stress or stress correlates and environmental toxicants (bisphenol A, alcohol, phthalates, lead, chlorpyrifos, and traffic-related air pollution). We provide evidence indicating that concurrent or tandem exposure to chemical and non-chemical stressors during windows of rapid development is associated with sex-specific synergistic, potentiated and reversed effects on several neuroendocrine endpoints related to hypothalamic-pituitary-adrenal axis function, sex steroid levels, neurotransmitter circuits, and innate immune function. We additionally identify gaps, such as the role that the endocrine-active placenta plays, in our understanding of these complex interactions. Finally, we discuss future research needs, including the investigation of non-hormonal biomarkers of stress. We demonstrate multiple physiologic systems are impacted by joint exposure to chemical and non-chemical stressors differentially among males and females. Collectively, the results highlight the importance of evaluating sex-specific endpoints when investigating the neuroendocrine system and underscore the need to examine exposure to chemical toxicants within the context of the social environment.

Selected contribution: a three-dimensional model for assessment of in vitro toxicity in balaena mysticetus renal tissue

NASA Technical Reports Server (NTRS)

Goodwin, T. J.; Coate-Li, L.; Linnehan, R. M.; Hammond, T. G.

2000-01-01

This study established two- and three-dimensional renal proximal tubular cell cultures of the endangered species bowhead whale (Balaena mysticetus), developed SV40-transfected cultures, and cloned the 61-amino acid open reading frame for the metallothionein protein, the primary binding site for heavy metal contamination in mammals. Microgravity research, modulations in mechanical culture conditions (modeled microgravity), and shear stress have spawned innovative approaches to understanding the dynamics of cellular interactions, gene expression, and differentiation in several cellular systems. These investigations have led to the creation of ex vivo tissue models capable of serving as physiological research analogs for three-dimensional cellular interactions. These models are enabling studies in immune function, tissue modeling for basic research, and neoplasia. Three-dimensional cellular models emulate aspects of in vivo cellular architecture and physiology and may facilitate environmental toxicological studies aimed at elucidating biological functions and responses at the cellular level. Marine mammals occupy a significant ecological niche (72% of the Earth's surface is water) in terms of the potential for information on bioaccumulation and transport of terrestrial and marine environmental toxins in high-order vertebrates. Few ex vivo models of marine mammal physiology exist in vitro to accomplish the aforementioned studies. Techniques developed in this investigation, based on previous tissue modeling successes, may serve to facilitate similar research in other marine mammals.

Expression of root-related transcription factors associated with flooding tolerance of soybean (Glycine max).

PubMed

Valliyodan, Babu; Van Toai, Tara T; Alves, Jose Donizeti; de Fátima P Goulart, Patricia; Lee, Jeong Dong; Fritschi, Felix B; Rahman, Mohammed Atiqur; Islam, Rafiq; Shannon, J Grover; Nguyen, Henry T

2014-09-29

Much research has been conducted on the changes in gene expression of the model plant Arabidopsis to low-oxygen stress. Flooding results in a low oxygen environment in the root zone. However, there is ample evidence that tolerance to soil flooding is more than tolerance to low oxygen alone. In this study, we investigated the physiological response and differential expression of root-related transcription factors (TFs) associated with the tolerance of soybean plants to soil flooding. Differential responses of PI408105A and S99-2281 plants to ten days of soil flooding were evaluated at physiological, morphological and anatomical levels. Gene expression underlying the tolerance response was investigated using qRT-PCR of root-related TFs, known anaerobic genes, and housekeeping genes. Biomass of flood-sensitive S99-2281 roots remained unchanged during the entire 10 days of flooding. Flood-tolerant PI408105A plants exhibited recovery of root growth after 3 days of flooding. Flooding induced the development of aerenchyma and adventitious roots more rapidly in the flood-tolerant than the flood-sensitive genotype. Roots of tolerant plants also contained more ATP than roots of sensitive plants at the 7th and 10th days of flooding. Quantitative transcript analysis identified 132 genes differentially expressed between the two genotypes at one or more time points of flooding. Expression of genes related to the ethylene biosynthesis pathway and formation of adventitious roots was induced earlier and to higher levels in roots of the flood-tolerant genotype. Three potential flood-tolerance TFs which were differentially expressed between the two genotypes during the entire 10-day flooding duration were identified. This study confirmed the expression of anaerobic genes in response to soil flooding. Additionally, the differential expression of TFs associated with soil flooding tolerance was not qualitative but quantitative and temporal. Functional analyses of these genes will be necessary to reveal their potential to enhance flooding tolerance of soybean cultivars.

Expression of Root-Related Transcription Factors Associated with Flooding Tolerance of Soybean (Glycine max)

PubMed Central

Valliyodan, Babu; Van Toai, Tara T.; Alves, Jose Donizeti; de Fátima P. Goulart, Patricia; Lee, Jeong Dong; Fritschi, Felix B.; Rahman, Mohammed Atiqur; Islam, Rafiq; Shannon, J. Grover; Nguyen, Henry T.

2014-01-01

Much research has been conducted on the changes in gene expression of the model plant Arabidopsis to low-oxygen stress. Flooding results in a low oxygen environment in the root zone. However, there is ample evidence that tolerance to soil flooding is more than tolerance to low oxygen alone. In this study, we investigated the physiological response and differential expression of root-related transcription factors (TFs) associated with the tolerance of soybean plants to soil flooding. Differential responses of PI408105A and S99-2281 plants to ten days of soil flooding were evaluated at physiological, morphological and anatomical levels. Gene expression underlying the tolerance response was investigated using qRT-PCR of root-related TFs, known anaerobic genes, and housekeeping genes. Biomass of flood-sensitive S99-2281 roots remained unchanged during the entire 10 days of flooding. Flood-tolerant PI408105A plants exhibited recovery of root growth after 3 days of flooding. Flooding induced the development of aerenchyma and adventitious roots more rapidly in the flood-tolerant than the flood-sensitive genotype. Roots of tolerant plants also contained more ATP than roots of sensitive plants at the 7th and 10th days of flooding. Quantitative transcript analysis identified 132 genes differentially expressed between the two genotypes at one or more time points of flooding. Expression of genes related to the ethylene biosynthesis pathway and formation of adventitious roots was induced earlier and to higher levels in roots of the flood-tolerant genotype. Three potential flood-tolerance TFs which were differentially expressed between the two genotypes during the entire 10-day flooding duration were identified. This study confirmed the expression of anaerobic genes in response to soil flooding. Additionally, the differential expression of TFs associated with soil flooding tolerance was not qualitative but quantitative and temporal. Functional analyses of these genes will be necessary to reveal their potential to enhance flooding tolerance of soybean cultivars. PMID:25268626

Co-regulation of Primary Mouse Hepatocyte Viability and Function by Oxygen and Matrix

PubMed Central

Buck, Lorenna D.; Inman, S. Walker; Rusyn, Ivan; Griffith, Linda G.

2014-01-01

Although oxygen and extracellular matrix cues both influence differentiation state and metabolic function of primary rat and human hepatocytes, relatively little is known about how these factors together regulate behaviors of primary mouse hepatocytes in culture. To determine the effects of pericellular oxygen tension on hepatocellular function, we employed 2 methods of altering oxygen concentration in the local cellular microenvironment of cells cultured in the presence or absence of an extracellular matrix (Matrigel) supplement. By systematically altering medium depth and gas phase oxygen tension, we created multiple oxygen regimes (hypoxic, normoxic, and hyperoxic) and measured the local oxygen concentrations in the pericellular environment using custom-designed oxygen microprobes. From these measurements of oxygen concentrations, we derived values of oxygen consumption rates under a spectrum of environmental contexts, thus providing the first reported estimates of these values for primary mouse hepatocytes. Oxygen tension and matrix microenvironment were found to synergistically regulate hepatocellular survival and function as assessed using quantitative image analysis for cells stained with vital dyes, and assessment of secretion of albumin. Hepatocellular viability was affected only at strongly hypoxic conditions. Surprisingly, albumin secretion rates were greatest at a moderately supra-physiological oxygen concentration, and this effect was mitigated at still greater supra-physiological concentrations. Matrigel enhanced the effects of oxygen on retention of function. This study underscores the importance of carefully controlling cell density, medium depth and gas phase oxygen, as the effects of these parameters on local pericellular oxygen tension and subsequent hepatocellular function are profound. PMID:24222008

Mechanical stretching for tissue engineering: two-dimensional and three-dimensional constructs.

PubMed

Riehl, Brandon D; Park, Jae-Hong; Kwon, Il Keun; Lim, Jung Yul

2012-08-01

Mechanical cell stretching may be an attractive strategy for the tissue engineering of mechanically functional tissues. It has been demonstrated that cell growth and differentiation can be guided by cell stretch with minimal help from soluble factors and engineered tissues that are mechanically stretched in bioreactors may have superior organization, functionality, and strength compared with unstretched counterparts. This review explores recent studies on cell stretching in both two-dimensional (2D) and three-dimensional (3D) setups focusing on the applications of stretch stimulation as a tool for controlling cell orientation, growth, gene expression, lineage commitment, and differentiation and for achieving successful tissue engineering of mechanically functional tissues, including cardiac, muscle, vasculature, ligament, tendon, bone, and so on. Custom stretching devices and lab-specific mechanical bioreactors are described with a discussion on capabilities and limitations. While stretch mechanotransduction pathways have been examined using 2D stretch, studying such pathways in physiologically relevant 3D environments may be required to understand how cells direct tissue development under stretch. Cell stretch study using 3D milieus may also help to develop tissue-specific stretch regimens optimized with biochemical feedback, which once developed will provide optimal tissue engineering protocols.

Mechanical Stretching for Tissue Engineering: Two-Dimensional and Three-Dimensional Constructs

PubMed Central

Riehl, Brandon D.; Park, Jae-Hong; Kwon, Il Keun

2012-01-01

Mechanical cell stretching may be an attractive strategy for the tissue engineering of mechanically functional tissues. It has been demonstrated that cell growth and differentiation can be guided by cell stretch with minimal help from soluble factors and engineered tissues that are mechanically stretched in bioreactors may have superior organization, functionality, and strength compared with unstretched counterparts. This review explores recent studies on cell stretching in both two-dimensional (2D) and three-dimensional (3D) setups focusing on the applications of stretch stimulation as a tool for controlling cell orientation, growth, gene expression, lineage commitment, and differentiation and for achieving successful tissue engineering of mechanically functional tissues, including cardiac, muscle, vasculature, ligament, tendon, bone, and so on. Custom stretching devices and lab-specific mechanical bioreactors are described with a discussion on capabilities and limitations. While stretch mechanotransduction pathways have been examined using 2D stretch, studying such pathways in physiologically relevant 3D environments may be required to understand how cells direct tissue development under stretch. Cell stretch study using 3D milieus may also help to develop tissue-specific stretch regimens optimized with biochemical feedback, which once developed will provide optimal tissue engineering protocols. PMID:22335794

Catechol-O-Methyltransferase Val158Met Polymorphism Associates with Individual Differences in Sleep Physiologic Responses to Chronic Sleep Loss

PubMed Central

Goel, Namni; Banks, Siobhan; Lin, Ling; Mignot, Emmanuel; Dinges, David F.

2011-01-01

Background The COMT Val158Met polymorphism modulates cortical dopaminergic catabolism, and predicts individual differences in prefrontal executive functioning in healthy adults and schizophrenic patients, and associates with EEG differences during sleep loss. We assessed whether the COMT Val158Met polymorphism was a novel marker in healthy adults of differential vulnerability to chronic partial sleep deprivation (PSD), a condition distinct from total sleep loss and one experienced by millions on a daily and persistent basis. Methodology/Principal Findings 20 Met/Met, 64 Val/Met, and 45 Val/Val subjects participated in a protocol of two baseline 10h time in bed (TIB) nights followed by five consecutive 4 h TIB nights. Met/Met subjects showed differentially steeper declines in non-REM EEG slow-wave energy (SWE)—the putative homeostatic marker of sleep drive—during PSD, despite comparable baseline SWE declines. Val/Val subjects showed differentially smaller increases in slow-wave sleep and smaller reductions in stage 2 sleep during PSD, and had more stage 1 sleep across nights and a shorter baseline REM sleep latency. The genotypes, however, did not differ in performance across various executive function and cognitive tasks and showed comparable increases in subjective and physiological sleepiness in response to chronic sleep loss. Met/Met genotypic and Met allelic frequencies were higher in whites than African Americans. Conclusions/Significance The COMT Val158Met polymorphism may be a genetic biomarker for predicting individual differences in sleep physiology—but not in cognitive and executive functioning—resulting from sleep loss in a healthy, racially-diverse adult population of men and women. Beyond healthy sleepers, our results may also provide insight for predicting sleep loss responses in patients with schizophrenia and other psychiatric disorders, since these groups repeatedly experience chronically-curtailed sleep and demonstrate COMT-related treatment responses and risk factors for symptom exacerbation. PMID:22216231

Physiologic measures of sexual function in women: a review.

PubMed

Woodard, Terri L; Diamond, Michael P

2009-07-01

To review and describe physiologic measures of assessing sexual function in women. Literature review. Studies that use instruments designed to measure female sexual function. Women participating in studies of female sexual function. Various instruments that measure physiologic features of female sexual function. Appraisal of the various instruments, including their advantages and disadvantages. Many unique physiologic methods of evaluating female sexual function have been developed during the past four decades. Each method has its benefits and limitations. Many physiologic methods exist, but most are not well-validated. In addition there has been an inability to correlate most physiologic measures with subjective measures of sexual arousal. Furthermore, given the complex nature of the sexual response in women, physiologic measures should be considered in context of other data, including the history, physical examination, and validated questionnaires. Nonetheless, the existence of appropriate physiologic measures is vital to our understanding of female sexual function and dysfunction.

Quantification of Global Diastolic Function by Kinematic Modeling-based Analysis of Transmitral Flow via the Parametrized Diastolic Filling Formalism

PubMed Central

Mossahebi, Sina; Zhu, Simeng; Chen, Howard; Shmuylovich, Leonid; Ghosh, Erina; Kovács, Sándor J.

2014-01-01

Quantitative cardiac function assessment remains a challenge for physiologists and clinicians. Although historically invasive methods have comprised the only means available, the development of noninvasive imaging modalities (echocardiography, MRI, CT) having high temporal and spatial resolution provide a new window for quantitative diastolic function assessment. Echocardiography is the agreed upon standard for diastolic function assessment, but indexes in current clinical use merely utilize selected features of chamber dimension (M-mode) or blood/tissue motion (Doppler) waveforms without incorporating the physiologic causal determinants of the motion itself. The recognition that all left ventricles (LV) initiate filling by serving as mechanical suction pumps allows global diastolic function to be assessed based on laws of motion that apply to all chambers. What differentiates one heart from another are the parameters of the equation of motion that governs filling. Accordingly, development of the Parametrized Diastolic Filling (PDF) formalism has shown that the entire range of clinically observed early transmitral flow (Doppler E-wave) patterns are extremely well fit by the laws of damped oscillatory motion. This permits analysis of individual E-waves in accordance with a causal mechanism (recoil-initiated suction) that yields three (numerically) unique lumped parameters whose physiologic analogues are chamber stiffness (k), viscoelasticity/relaxation (c), and load (xo). The recording of transmitral flow (Doppler E-waves) is standard practice in clinical cardiology and, therefore, the echocardiographic recording method is only briefly reviewed. Our focus is on determination of the PDF parameters from routinely recorded E-wave data. As the highlighted results indicate, once the PDF parameters have been obtained from a suitable number of load varying E-waves, the investigator is free to use the parameters or construct indexes from the parameters (such as stored energy 1/2kxo2, maximum A-V pressure gradient kxo, load independent index of diastolic function, etc.) and select the aspect of physiology or pathophysiology to be quantified. PMID:25226101

Quantification of global diastolic function by kinematic modeling-based analysis of transmitral flow via the parametrized diastolic filling formalism.

PubMed

Mossahebi, Sina; Zhu, Simeng; Chen, Howard; Shmuylovich, Leonid; Ghosh, Erina; Kovács, Sándor J

2014-09-01

Quantitative cardiac function assessment remains a challenge for physiologists and clinicians. Although historically invasive methods have comprised the only means available, the development of noninvasive imaging modalities (echocardiography, MRI, CT) having high temporal and spatial resolution provide a new window for quantitative diastolic function assessment. Echocardiography is the agreed upon standard for diastolic function assessment, but indexes in current clinical use merely utilize selected features of chamber dimension (M-mode) or blood/tissue motion (Doppler) waveforms without incorporating the physiologic causal determinants of the motion itself. The recognition that all left ventricles (LV) initiate filling by serving as mechanical suction pumps allows global diastolic function to be assessed based on laws of motion that apply to all chambers. What differentiates one heart from another are the parameters of the equation of motion that governs filling. Accordingly, development of the Parametrized Diastolic Filling (PDF) formalism has shown that the entire range of clinically observed early transmitral flow (Doppler E-wave) patterns are extremely well fit by the laws of damped oscillatory motion. This permits analysis of individual E-waves in accordance with a causal mechanism (recoil-initiated suction) that yields three (numerically) unique lumped parameters whose physiologic analogues are chamber stiffness (k), viscoelasticity/relaxation (c), and load (xo). The recording of transmitral flow (Doppler E-waves) is standard practice in clinical cardiology and, therefore, the echocardiographic recording method is only briefly reviewed. Our focus is on determination of the PDF parameters from routinely recorded E-wave data. As the highlighted results indicate, once the PDF parameters have been obtained from a suitable number of load varying E-waves, the investigator is free to use the parameters or construct indexes from the parameters (such as stored energy 1/2kxo(2), maximum A-V pressure gradient kxo, load independent index of diastolic function, etc.) and select the aspect of physiology or pathophysiology to be quantified.

Physiological thermoregulation in a crustacean? Heart rate hysteresis in the freshwater crayfish Cherax destructor.

PubMed

Goudkamp, Jacqueline E; Seebacher, Frank; Ahern, Mark; Franklin, Craig E

2004-07-01

Differential heart rates during heating and cooling (heart rate hysteresis) are an important thermoregulatory mechanism in ectothermic reptiles. We speculate that heart rate hysteresis has evolved alongside vascularisation, and to determine whether this phenomenon occurs in a lineage with vascularised circulatory systems that is phylogenetically distant from reptiles, we measured the response of heart rate to convective heat transfer in the Australian freshwater crayfish, Cherax destructor. Heart rate during convective heating (from 20 to 30 degrees C) was significantly faster than during cooling for any given body temperature. Heart rate declined rapidly immediately following the removal of the heat source, despite only negligible losses in body temperature. This heart rate 'hysteresis' is similar to the pattern reported in many reptiles and, by varying peripheral blood flow, it is presumed to confer thermoregulatory benefits particularly given the thermal sensitivity of many physiological rate functions in crustaceans.

New approaches to thyroid hormones and purinergic signaling.

PubMed

Silveira, Gabriel Fernandes; Buffon, Andréia; Bruno, Alessandra Nejar

2013-01-01

It is known that thyroid hormones influence a wide variety of events at the molecular, cellular, and functional levels. Thyroid hormones (TH) play pivotal roles in growth, cell proliferation, differentiation, apoptosis, development, and metabolic homeostasis via thyroid hormone receptors (TRs) by controlling the expression of TR target genes. Most of these effects result in pathological and physiological events and are already well described in the literature. Even so, many recent studies have been devoted to bringing new information on problems in controlling the synthesis and release of these hormones and to elucidating mechanisms of the action of these hormones unconventionally. The purinergic system was recently linked to thyroid diseases, including enzymes, receptors, and enzyme products related to neurotransmitter release, nociception, behavior, and other vascular systems. Thus, throughout this text we intend to relate the relationship between the TH in physiological and pathological situations with the purinergic signaling.

New Approaches to Thyroid Hormones and Purinergic Signaling

PubMed Central

Silveira, Gabriel Fernandes; Buffon, Andréia; Bruno, Alessandra Nejar

2013-01-01

It is known that thyroid hormones influence a wide variety of events at the molecular, cellular, and functional levels. Thyroid hormones (TH) play pivotal roles in growth, cell proliferation, differentiation, apoptosis, development, and metabolic homeostasis via thyroid hormone receptors (TRs) by controlling the expression of TR target genes. Most of these effects result in pathological and physiological events and are already well described in the literature. Even so, many recent studies have been devoted to bringing new information on problems in controlling the synthesis and release of these hormones and to elucidating mechanisms of the action of these hormones unconventionally. The purinergic system was recently linked to thyroid diseases, including enzymes, receptors, and enzyme products related to neurotransmitter release, nociception, behavior, and other vascular systems. Thus, throughout this text we intend to relate the relationship between the TH in physiological and pathological situations with the purinergic signaling. PMID:23956925

Multiple Functions of Endocannabinoid Signaling in the Brain

PubMed Central

Katona, István; Freund, Tamás F.

2014-01-01

Despite being regarded as a hippie science for decades, cannabinoid research has finally found its well-deserved position in mainstream neuroscience. A series of groundbreaking discoveries revealed that endocannabinoid molecules are as widespread and important as conventional neurotransmitters like glutamate or GABA, yet act in profoundly unconventional ways. We aim to illustrate how uncovering the molecular, anatomical and physiological characteristics of endocannabinoid signaling revealed new mechanistic insights into several fundamental phenomena in synaptic physiology. First, we summarize unexpected advances in the molecular complexity of biogenesis and inactivation of the two endocannabinoids, anandamide and 2-arachidonoylglycerol. Then we show how these new metabolic routes are integrated into well-known intracellular signaling pathways. These endocannabinoid-producing signalosomes operate in phasic and tonic modes thereby differentially governing homeostatic, short-term and long-term synaptic plasticity throughout the brain. Finally, we discuss how cell type- and synapse-specific refinement of endocannabinoid signaling may explain the characteristic behavioral effects of cannabinoids. PMID:22524785

Comparative studies of differential expression of chitinolytic enzymes encoded by chiA, chiB, chiC and nagA genes in Aspergillus nidulans.

PubMed

Pusztahelyi, T; Molnár, Z; Emri, T; Klement, E; Miskei, M; Kerékgyárto, J; Balla, J; Pócsi, I

2006-01-01

N-Acetyl-D-glucosamine, chito-oligomers and carbon starvation regulated chiA, chiB, and nagA gene expressions in Aspergillus nidulans cultures. The gene expression patterns of the main extracellular endochitinase ChiB and the N-acetyl-beta-D-glucosaminidase NagA were similar, and the ChiB-NagA enzyme system may play a morphological and/or nutritional role during autolysis. Alterations in the levels of reactive oxygen species or in the glutathione-glutathione disulfide redox balance, characteristic physiological changes developing in ageing and autolyzing fungal cultures, did not affect the regulation of either the growth-related chiA or the autolysis-coupled chiB genes although both of them were down-regulated under diamide stress. The transcription of the chiC gene with unknown physiological function was repressed by increased intracellular superoxide concentration.

Improving the clinical assessment of consciousness with advances in electrophysiological and neuroimaging techniques

PubMed Central

2010-01-01

In clinical neurology, a comprehensive understanding of consciousness has been regarded as an abstract concept - best left to philosophers. However, times are changing and the need to clinically assess consciousness is increasingly becoming a real-world, practical challenge. Current methods for evaluating altered levels of consciousness are highly reliant on either behavioural measures or anatomical imaging. While these methods have some utility, estimates of misdiagnosis are worrisome (as high as 43%) - clearly this is a major clinical problem. The solution must involve objective, physiologically based measures that do not rely on behaviour. This paper reviews recent advances in physiologically based measures that enable better evaluation of consciousness states (coma, vegetative state, minimally conscious state, and locked in syndrome). Based on the evidence to-date, electroencephalographic and neuroimaging based assessments of consciousness provide valuable information for evaluation of residual function, formation of differential diagnoses, and estimation of prognosis. PMID:20113490

Brain mesenchymal stem cells: physiology and pathological implications.

PubMed

Pombero, Ana; Garcia-Lopez, Raquel; Martinez, Salvador

2016-06-01

Mesenchymal stem cells (MSCs) are defined as progenitor cells that give rise to a number of unique, differentiated mesenchymal cell types. This concept has progressively evolved towards an all-encompassing concept including multipotent perivascular cells of almost any tissue. In central nervous system, pericytes are involved in blood-brain barrier, and angiogenesis and vascular tone regulation. They form the neurovascular unit (NVU) together with endothelial cells, astrocytes and neurons. This functional structure provides an optimal microenvironment for neural proliferation in the adult brain. Neurovascular niche include both diffusible signals and direct contact with endothelial and pericytes, which are a source of diffusible neurotrophic signals that affect neural precursors. Therefore, MSCs/pericyte properties such as differentiation capability, as well as immunoregulatory and paracrine effects make them a potential resource in regenerative medicine. © 2016 Japanese Society of Developmental Biologists.

Roles of mTOR Signaling in Brain Development.

PubMed

Lee, Da Yong

2015-09-01

mTOR is a serine/threonine kinase composed of multiple protein components. Intracellular signaling of mTOR complexes is involved in many of physiological functions including cell survival, proliferation and differentiation through the regulation of protein synthesis in multiple cell types. During brain development, mTOR-mediated signaling pathway plays a crucial role in the process of neuronal and glial differentiation and the maintenance of the stemness of neural stem cells. The abnormalities in the activity of mTOR and its downstream signaling molecules in neural stem cells result in severe defects of brain developmental processes causing a significant number of brain disorders, such as pediatric brain tumors, autism, seizure, learning disability and mental retardation. Understanding the implication of mTOR activity in neural stem cells would be able to provide an important clue in the development of future brain developmental disorder therapies.

Physiological Jak2V617F expression causes a lethal myeloproliferative neoplasm with differential effects on hematopoietic stem and progenitor cells.

PubMed

Mullally, Ann; Lane, Steven W; Ball, Brian; Megerdichian, Christine; Okabe, Rachel; Al-Shahrour, Fatima; Paktinat, Mahnaz; Haydu, J Erika; Housman, Elizabeth; Lord, Allegra M; Wernig, Gerlinde; Kharas, Michael G; Mercher, Thomas; Kutok, Jeffery L; Gilliland, D Gary; Ebert, Benjamin L

2010-06-15

We report a Jak2V617F knockin mouse myeloproliferative neoplasm (MPN) model resembling human polycythemia vera (PV). The MPN is serially transplantable and we demonstrate that the hematopoietic stem cell (HSC) compartment has the unique capacity for disease initiation but does not have a significant selective competitive advantage over wild-type HSCs. In contrast, myeloid progenitor populations are expanded and skewed toward the erythroid lineage, but cannot transplant the disease. Treatment with a JAK2 kinase inhibitor ameliorated the MPN phenotype, but did not eliminate the disease-initiating population. These findings provide insights into the consequences of JAK2 activation on HSC differentiation and function and have the potential to inform therapeutic approaches to JAK2V617F-positive MPN. Copyright 2010 Elsevier Inc. All rights reserved.

Role of nitric oxide in the maintenance of pluripotency and regulation of the hypoxia response in stem cells

PubMed Central

Beltran-Povea, Amparo; Caballano-Infantes, Estefania; Salguero-Aranda, Carmen; Martín, Franz; Soria, Bernat; Bedoya, Francisco J; Tejedo, Juan R; Cahuana, Gladys M

2015-01-01

Stem cell pluripotency and differentiation are global processes regulated by several pathways that have been studied intensively over recent years. Nitric oxide (NO) is an important molecule that affects gene expression at the level of transcription and translation and regulates cell survival and proliferation in diverse cell types. In embryonic stem cells NO has a dual role, controlling differentiation and survival, but the molecular mechanisms by which it modulates these functions are not completely defined. NO is a physiological regulator of cell respiration through the inhibition of cytochrome c oxidase. Many researchers have been examining the role that NO plays in other aspects of metabolism such as the cellular bioenergetics state, the hypoxia response and the relationship of these areas to stem cell stemness. PMID:25914767

Coping styles and behavioural flexibility: towards underlying mechanisms

PubMed Central

Coppens, Caroline M.; de Boer, Sietse F.; Koolhaas, Jaap M.

2010-01-01

A coping style (also termed behavioural syndrome or personality) is defined as a correlated set of individual behavioural and physiological characteristics that is consistent over time and across situations. This relatively stable trait is a fundamental and adaptively significant phenomenon in the biology of a broad range of species, i.e. it confers differential fitness consequences under divergent environmental conditions. Behavioural flexibility appears to be an important underlying attribute or feature of the coping style that might explain consistency across situations. Proactive coping is characterized by low flexibility expressed as rather rigid, routine-like behavioural tendencies and reduced impulse control (behavioural inhibition) in operant conditioning paradigms. This article summarizes some of the evidence that individual differentiation in behavioural flexibility emerges as a function of underlying variability in the activation of a brain circuitry that includes the prefrontal cortex and its key neurochemical signalling pathways (e.g. dopaminergic and serotonergic input). We argue that the multidimensional nature of animal personality and the terminology used for the various dimensions should reflect the differential pattern of activation of the underlying neuronal network and the behavioural control function of its components. Accordingly, unravelling the molecular mechanisms that give rise to individual differences in the coping style will be an important topic in biobehavioural neurosciences, ecology and evolutionary biology. PMID:21078654

Proliferative Glioblastoma Cancer Cells Exhibit Persisting Temporal Control of Metabolism and Display Differential Temporal Drug Susceptibility in Chemotherapy.

PubMed

Wagner, Paula M; Sosa Alderete, Lucas G; Gorné, Lucas D; Gaveglio, Virginia; Salvador, Gabriela; Pasquaré, Susana; Guido, Mario E

2018-06-07

Even in immortalized cell lines, circadian clocks regulate physiological processes in a time-dependent manner, driving transcriptional and metabolic rhythms, the latter being able to persist without transcription. Circadian rhythm disruptions in modern life (shiftwork, jetlag, etc.) may lead to higher cancer risk. Here, we investigated whether the human glioblastoma T98G cells maintained quiescent or under proliferation keep a functional clock and whether cells display differential time responses to bortezomib chemotherapy. In arrested cultures, mRNAs for clock (Per1, Rev-erbα) and glycerophospholipid (GPL)-synthesizing enzyme genes, 32 P-GPL labeling, and enzyme activities exhibited circadian rhythmicity; oscillations were also found in the redox state/peroxiredoxin oxidation. In proliferating cells, rhythms of gene expression were lost or their periodicity shortened whereas the redox and GPL metabolisms continued to fluctuate with a similar periodicity as under arrest. Cell viability significantly changed over time after bortezomib treatment; however, this rhythmicity and the redox cycles were altered after Bmal1 knock-down, indicating cross-talk between the transcriptional and the metabolic oscillators. An intrinsic metabolic clock continues to function in proliferating cells, controlling diverse metabolisms and highlighting differential states of tumor suitability for more efficient, time-dependent chemotherapy when the redox state is high and GPL metabolism low.

Differentially Expressed Genes in Hirudo medicinalis Ganglia after Acetyl-L-Carnitine Treatment

PubMed Central

Federighi, Giuseppe; Macchi, Monica; Bernardi, Rodolfo; Scuri, Rossana; Brunelli, Marcello; Durante, Mauro; Traina, Giovanna

2013-01-01

Acetyl-l-carnitine (ALC) is a naturally occurring substance that, when administered at supra-physiological concentration, is neuroprotective. It is involved in membrane stabilization and in enhancement of mitochondrial functions. It is a molecule of considerable interest for its clinical application in various neural disorders, including Alzheimer’s disease and painful neuropathies. ALC is known to improve the cognitive capability of aged animals chronically treated with the drug and, recently, it has been reported that it impairs forms of non-associative learning in the leech. In the present study the effects of ALC on gene expression have been analyzed in the leech Hirudo medicinalis. The suppression subtractive hybridisation methodology was used for the generation of subtracted cDNA libraries and the subsequent identification of differentially expressed transcripts in the leech nervous system after ALC treatment. The method detects differentially but also little expressed transcripts of genes whose sequence or identity is still unknown. We report that a single administration of ALC is able to modulate positively the expression of genes coding for functions that reveal a lasting effect of ALC on the invertebrate, and confirm the neuroprotective and neuromodulative role of the substance. In addition an important finding is the modulation of genes of vegetal origin. This might be considered an instance of ectosymbiotic mutualism. PMID:23308261

Vitronectin as a Micromanager of Cell Response in Material-Driven Fibronectin Nanonetworks.

PubMed

Cantini, Marco; Gomide, Karina; Moulisova, Vladimira; González-García, Cristina; Salmerón-Sánchez, Manuel

2017-09-01

Surface functionalization strategies of synthetic materials for regenerative medicine applications comprise the development of microenvironments that recapitulate the physical and biochemical cues of physiological extracellular matrices. In this context, material-driven fibronectin (FN) nanonetworks obtained from the adsorption of the protein on poly(ethyl acrylate) provide a robust system to control cell behavior, particularly to enhance differentiation. This study aims at augmenting the complexity of these fibrillar matrices by introducing vitronectin, a lower-molecular-weight multifunctional glycoprotein and main adhesive component of serum. A cooperative effect during co-adsorption of the proteins is observed, as the addition of vitronectin leads to increased fibronectin adsorption, improved fibril formation, and enhanced vitronectin exposure. The mobility of the protein at the material interface increases, and this, in turn, facilitates the reorganization of the adsorbed FN by cells. Furthermore, the interplay between interface mobility and engagement of vitronectin receptors controls the level of cell fusion and the degree of cell differentiation. Ultimately, this work reveals that substrate-induced protein interfaces resulting from the cooperative adsorption of fibronectin and vitronectin fine-tune cell behavior, as vitronectin micromanages the local properties of the microenvironment and consequently short-term cell response to the protein interface and higher order cellular functions such as differentiation.

An enzyme-linked immunosorbent assay-based system for determining the physiological level of poly(ADP-ribose) in cultured cells.

PubMed

Ida, Chieri; Yamashita, Sachiko; Tsukada, Masaki; Sato, Teruaki; Eguchi, Takayuki; Tanaka, Masakazu; Ogata, Shin; Fujii, Takahiro; Nishi, Yoshisuke; Ikegami, Susumu; Moss, Joel; Miwa, Masanao

2016-02-01

PolyADP-ribosylation is mediated by poly(ADP-ribose) (PAR) polymerases (PARPs) and may be involved in various cellular events, including chromosomal stability, DNA repair, transcription, cell death, and differentiation. The physiological level of PAR is difficult to determine in intact cells because of the rapid synthesis of PAR by PARPs and the breakdown of PAR by PAR-degrading enzymes, including poly(ADP-ribose) glycohydrolase (PARG) and ADP-ribosylhydrolase 3. Artifactual synthesis and/or degradation of PAR likely occurs during lysis of cells in culture. We developed a sensitive enzyme-linked immunosorbent assay (ELISA) to measure the physiological levels of PAR in cultured cells. We immediately inactivated enzymes that catalyze the synthesis and degradation of PAR. We validated that trichloroacetic acid is suitable for inactivating PARPs, PARG, and other enzymes involved in metabolizing PAR in cultured cells during cell lysis. The PAR level in cells harvested with the standard radioimmunoprecipitation assay buffer was increased by 450-fold compared with trichloroacetic acid for lysis, presumably because of activation of PARPs by DNA damage that occurred during cell lysis. This ELISA can be used to analyze the biological functions of polyADP-ribosylation under various physiological conditions in cultured cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Glycosylation Effects on FSH-FSHR Interaction Dynamics: A Case Study of Different FSH Glycoforms by Molecular Dynamics Simulations

PubMed Central

Meher, Biswa Ranjan; Dixit, Anshuman; Bousfield, George R.; Lushington, Gerald H.

2015-01-01

The gonadotropin known as follicle-stimulating hormone (FSH) plays a key role in regulating reproductive processes. Physiologically active FSH is a glycoprotein that can accommodate glycans on up to four asparagine residues, including two sites in the FSHα subunit that are critical for biochemical function, plus two sites in the β subunit, whose differential glycosylation states appear to correspond to physiologically distinct functions. Some degree of FSHβ hypo-glycosylation seems to confer advantages toward reproductive fertility of child-bearing females. In order to identify possible mechanistic underpinnings for this physiological difference we have pursued computationally intensive molecular dynamics simulations on complexes between the high affinity site of the gonadal FSH receptor (FSHR) and several FSH glycoforms including fully-glycosylated (FSH24), hypo-glycosylated (e.g., FSH15), and completely deglycosylated FSH (dgFSH). These simulations suggest that deviations in FSH/FSHR binding profile as a function of glycosylation state are modest when FSH is adorned with only small glycans, such as single N-acetylglucosamine residues. However, substantial qualitative differences emerge between FSH15 and FSH24 when FSH is decorated with a much larger, tetra-antennary glycan. Specifically, the FSHR complex with hypo-glycosylated FSH15 is observed to undergo a significant conformational shift after 5–10 ns of simulation, indicating that FSH15 has greater conformational flexibility than FSH24 which may explain the more favorable FSH15 kinetic profile. FSH15 also exhibits a stronger binding free energy, due in large part to formation of closer and more persistent salt-bridges with FSHR. PMID:26402790

Ovarian expression of cellular Ki-ras p21 varies with physiological status.

PubMed Central

Palejwala, S; Goldsmith, L T

1992-01-01

To elucidate the potential role of the ras protooncogene proteins in a specific tissue, the present study determined the levels of individual c-ras-encoded p21 proteins in the rat ovary during various stages of physiological function. p21 protein was extracted from ovaries taken from immature normal female rats, mature nonpregnant animals in the metestrus stage of the estrus cycle, rats at various stages of pregnancy, and actively lactating animals. Levels of individual p21s were evaluated by immunoblot analysis with specific antibodies to the p21 proteins encoded by the Kirsten, Harvey, and neuroblastoma c-ras protooncogenes, c-Ki-ras, c-Ha-ras, and N-ras. Results showed that c-Ki-ras p21 is at its lowest level in the immature ovary and increases with development of the corpora lutea to its highest levels at day 16 of pregnancy, after which levels decline and then rise again during lactation. This pattern, which mimics that of circulating progesterone levels, suggests that ovarian c-Ki-ras p21 levels are regulated and that c-Ki-ras p21 plays a role in the differentiated function of the rat ovary, likely the luteal compartment. In contrast, levels of c-N-ras p21 did not appear to vary with changes in the physiological function of the ovary but appeared to be constitutive. A preferential role for the c-Ki-ras p21 may be due to the documented unique differences in the structure of the carboxyl terminus of this particular c-ras p21. Images PMID:1570348

Saccharomyces cerevisiae Differential Functionalization of Presumed ScALT1 and ScALT2 Alanine Transaminases Has Been Driven by Diversification of Pyridoxal Phosphate Interactions

PubMed Central

Rojas-Ortega, Erendira; Aguirre-López, Beatriz; Reyes-Vivas, Horacio; González-Andrade, Martín; Campero-Basaldúa, Jose C.; Pardo, Juan P.; González, Alicia

2018-01-01

Saccharomyces cerevisiae arose from an interspecies hybridization (allopolyploidiza-tion), followed by Whole Genome Duplication. Diversification analysis of ScAlt1/ScAlt2 indicated that while ScAlt1 is an alanine transaminase, ScAlt2 lost this activity, constituting an example in which one of the members of the gene pair lacks the apparent ancestral physiological role. This paper analyzes structural organization and pyridoxal phosphate (PLP) binding properties of ScAlt1 and ScAlt2 indicating functional diversification could have determined loss of ScAlt2 alanine transaminase activity and thus its role in alanine metabolism. It was found that ScAlt1 and ScAlt2 are dimeric enzymes harboring 67% identity and intact conservation of the catalytic residues, with very similar structures. However, tertiary structure analysis indicated that ScAlt2 has a more open conformation than that of ScAlt1 so that under physiological conditions, while PLP interaction with ScAlt1 allows the formation of two tautomeric PLP isomers (enolimine and ketoenamine) ScAlt2 preferentially forms the ketoenamine PLP tautomer, indicating a modified polarity of the active sites which affect the interaction of PLP with these proteins, that could result in lack of alanine transaminase activity in ScAlt2. The fact that ScAlt2 forms a catalytically active Schiff base with PLP and its position in an independent clade in “sensu strictu” yeasts suggests this protein has a yet undiscovered physiological function. PMID:29867852

Chloroplast proteome response to drought stress and recovery in tomato (Solanum lycopersicum L.).

PubMed

Tamburino, Rachele; Vitale, Monica; Ruggiero, Alessandra; Sassi, Mauro; Sannino, Lorenza; Arena, Simona; Costa, Antonello; Batelli, Giorgia; Zambrano, Nicola; Scaloni, Andrea; Grillo, Stefania; Scotti, Nunzia

2017-02-10

Drought is a major constraint for plant growth and crop productivity that is receiving an increased attention due to global climate changes. Chloroplasts act as environmental sensors, however, only partial information is available on stress-induced mechanisms within plastids. Here, we investigated the chloroplast response to a severe drought treatment and a subsequent recovery cycle in tomato through physiological, metabolite and proteomic analyses. Under stress conditions, tomato plants showed stunted growth, and elevated levels of proline, abscisic acid (ABA) and late embryogenesis abundant gene transcript. Proteomics revealed that water deficit deeply affects chloroplast protein repertoire (31 differentially represented components), mainly involving energy-related functional species. Following the rewatering cycle, physiological parameters and metabolite levels indicated a recovery of tomato plant functions, while proteomics revealed a still ongoing adjustment of the chloroplast protein repertoire, which was even wider than during the drought phase (54 components differentially represented). Changes in gene expression of candidate genes and accumulation of ABA suggested the activation under stress of a specific chloroplast-to-nucleus (retrograde) signaling pathway and interconnection with the ABA-dependent network. Our results give an original overview on the role of chloroplast as enviromental sensor by both coordinating the expression of nuclear-encoded plastid-localised proteins and mediating plant stress response. Although our data suggest the activation of a specific retrograde signaling pathway and interconnection with ABA signaling network in tomato, the involvement and fine regulation of such pathway need to be further investigated through the development and characterization of ad hoc designed plant mutants.

Exploiting water versus tolerating drought: water-use strategies of trees in a secondary successional tropical dry forest.

PubMed

Pineda-García, Fernando; Paz, Horacio; Meinzer, Frederick C; Angeles, Guillermo

2016-02-01

In seasonal plant communities where water availability changes dramatically both between and within seasons, understanding the mechanisms that enable plants to exploit water pulses and to survive drought periods is crucial. By measuring rates of physiological processes, we examined the trade-off between water exploitation and drought tolerance among seedlings of trees of a tropical dry forest, and identified biophysical traits most closely associated with plant water-use strategies. We also explored whether early and late secondary successional species occupy different portions of trade-off axes. As predicted, species that maintained carbon capture, hydraulic function and leaf area at higher plant water deficits during drought had low photosynthetic rates, xylem hydraulic conductivity and growth rate under non-limiting water supply. Drought tolerance was associated with more dense leaf, stem and root tissues, whereas rapid resource acquisition was associated with greater stem water storage, larger vessel diameter and larger leaf area per mass invested. We offer evidence that the water exploitation versus drought tolerance trade-off drives species differentiation in the ability of tropical dry forest trees to deal with alternating water-drought pulses. However, we detected no evidence of strong functional differentiation between early and late successional species along the proposed trade-off axes, suggesting that the environmental gradient of water availability across secondary successional habitats in the dry tropics does not filter out physiological strategies of water use among species, at least at the seedling stage. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Function and regulation of MTA1 and MTA3 in malignancies of the female reproductive system.

PubMed

Brüning, Ansgar; Blankenstein, Thomas; Jückstock, Julia; Mylonas, Ioannis

2014-12-01

The family of metastasis-associated (MTA) genes is a small group of transcriptional co-regulators which are involved in various physiological functions, ranging from lymphopoietic cell differentiation to the development and maintenance of epithelial cell adhesions. By recruiting histone-modifying enzymes to specific promoter sequences, MTA proteins can function both as transcriptional repressors and activators of a number of cancer-relevant proteins, including Snail, E-cadherin, signal transducer and activator of transcriptions (STATs), and the estrogen receptor. Their involvement in the epithelial-mesenchymal transition process and regulatory interactions with estrogen receptor activity has made MTA proteins highly interesting research candidates, especially in the field of hormone-sensitive breast cancer and malignancies of the female reproductive tract. This review focuses on the current knowledge about the function and regulation of MTA1 and MTA3 proteins in gynecological cancer, including ovarian, endometrial, and cervical tumors.

The Segregated Expression of Voltage-Gated Potassium and Sodium Channels in Neuronal Membranes: Functional Implications and Regulatory Mechanisms

PubMed Central

Duménieu, Maël; Oulé, Marie; Kreutz, Michael R.; Lopez-Rojas, Jeffrey

2017-01-01

Neurons are highly polarized cells with apparent functional and morphological differences between dendrites and axon. A critical determinant for the molecular and functional identity of axonal and dendritic segments is the restricted expression of voltage-gated ion channels (VGCs). Several studies show an uneven distribution of ion channels and their differential regulation within dendrites and axons, which is a prerequisite for an appropriate integration of synaptic inputs and the generation of adequate action potential (AP) firing patterns. This review article will focus on the signaling pathways leading to segmented expression of voltage-gated potassium and sodium ion channels at the neuronal plasma membrane and the regulatory mechanisms ensuring segregated functions. We will also discuss the relevance of proper ion channel targeting for neuronal physiology and how alterations in polarized distribution contribute to neuronal pathology. PMID:28484374

Adsorption properties of polar/apolar inducers at a charged interface and their relevance to leukemia cell differentiation.

PubMed

Carlà, M; Cuomo, M; Arcangeli, A; Olivotto, M

1995-06-01

The interfacial adsorption properties of polar/apolar inducers of cell differentiation (PAIs) were studied on a mercury electrode. This study, on a clean and reproducible charged surface, unraveled the purely physical interactions among these compounds and the surface, apart from the complexity of the biological membrane. The interfacial behavior of two classical inducers, hexamethylenebisacetamide (HMBA) and dimethylsulfoxide, was compared with that of a typical apolar aliphatic compound, 1-octanol, that has a similar hydrophobic moiety as HMBA but a much smaller dipolar moment. Both HMBA and Octanol adsorb flat in contact with the surface because of hydrophobic forces, with a very similar free energy of adsorption. However, the ratio of polar to apolar moieties in PAIs turned out to be crucial to drive the adsorption maximum toward physiological values of surface charge density, where octanol is desorbed. The electrostatic effects in the interfacial region reflected the adsorption properties: the changes in the potential drop across the interfacial region as a function of the surface charge density, in the physiological range, were opposite in PAIs as compared with apolar aliphatic compounds, as exemplified by octanol. This peculiar electrostatic effect of PAIs has far-reaching relevance for the design of inducers with an adequate therapeutic index to be used in clinical trials.

Theoretical analysis of the mechanisms of a gender differentiation in the propensity for orthostatic intolerance after spaceflight

PubMed Central

2010-01-01

Background A tendency to develop reentry orthostasis after a prolonged exposure to microgravity is a common problem among astronauts. The problem is 5 times more prevalent in female astronauts as compared to their male counterparts. The mechanisms responsible for this gender differentiation are poorly understood despite many detailed and complex investigations directed toward an analysis of the physiologic control systems involved. Methods In this study, a series of computer simulation studies using a mathematical model of cardiovascular functioning were performed to examine the proposed hypothesis that this phenomenon could be explained by basic physical forces acting through the simple common anatomic differences between men and women. In the computer simulations, the circulatory components and hydrostatic gradients of the model were allowed to adapt to the physical constraints of microgravity. After a simulated period of one month, the model was returned to the conditions of earth's gravity and the standard postflight tilt test protocol was performed while the model output depicting the typical vital signs was monitored. Conclusions The analysis demonstrated that a 15% lowering of the longitudinal center of gravity in the anatomic structure of the model was all that was necessary to prevent the physiologic compensatory mechanisms from overcoming the propensity for reentry orthostasis leading to syncope. PMID:20298577

Differential Bacterial Colonization of Volcanic Minerals in Deep Thermal Basalts

NASA Astrophysics Data System (ADS)

Smith, A. R.; Popa, R.; Fisk, M. R.; Nielsen, M.; Wheat, G.; Jannasch, H.; Fisher, A.; Sievert, S.

2010-04-01

There are reports of microbial weathering patterns in volcanic glass and minerals of both terrestrial and Martian origin. Volcanic minerals are colonized differentially in subsurface hydrothermal environments by a variety of physiological types.

A simple theoretical framework for understanding heterogeneous differentiation of CD4+ T cells

PubMed Central

2012-01-01

Background CD4+ T cells have several subsets of functional phenotypes, which play critical yet diverse roles in the immune system. Pathogen-driven differentiation of these subsets of cells is often heterogeneous in terms of the induced phenotypic diversity. In vitro recapitulation of heterogeneous differentiation under homogeneous experimental conditions indicates some highly regulated mechanisms by which multiple phenotypes of CD4+ T cells can be generated from a single population of naïve CD4+ T cells. Therefore, conceptual understanding of induced heterogeneous differentiation will shed light on the mechanisms controlling the response of populations of CD4+ T cells under physiological conditions. Results We present a simple theoretical framework to show how heterogeneous differentiation in a two-master-regulator paradigm can be governed by a signaling network motif common to all subsets of CD4+ T cells. With this motif, a population of naïve CD4+ T cells can integrate the signals from their environment to generate a functionally diverse population with robust commitment of individual cells. Notably, two positive feedback loops in this network motif govern three bistable switches, which in turn, give rise to three types of heterogeneous differentiated states, depending upon particular combinations of input signals. We provide three prototype models illustrating how to use this framework to explain experimental observations and make specific testable predictions. Conclusions The process in which several types of T helper cells are generated simultaneously to mount complex immune responses upon pathogenic challenges can be highly regulated, and a simple signaling network motif can be responsible for generating all possible types of heterogeneous populations with respect to a pair of master regulators controlling CD4+ T cell differentiation. The framework provides a mathematical basis for understanding the decision-making mechanisms of CD4+ T cells, and it can be helpful for interpreting experimental results. Mathematical models based on the framework make specific testable predictions that may improve our understanding of this differentiation system. PMID:22697466

Differential interactions between Curtobacterium flaccumfaciens pv. flaccumfaciens and common bean.

PubMed

Valdo, S C D; Wendland, A; Araújo, L G; Melo, L C; Pereira, H S; Melo, P G; Faria, L C

2016-11-21

Bacterial wilt of common bean caused by Curtobacterium flaccumfaciens pv. flaccumfaciens is an important disease in terms of economic importance. It reduces grain yield by colonizing xylem vessels, subsequently impeding the translocation of water and nutrients to the superior plant parts. The existence of physiological races in C. flaccumfaciens pv. flaccumfaciens has not so far been reported. The objective of the present investigation was to identify physiological races, evaluate differential interaction, and select resistant genotypes of common bean. Initially, 30 genotypes of common bean were inoculated with eight isolates exhibiting different levels of aggressiveness, under controlled greenhouse conditions. Disease was assessed 15 days after inoculation. The existence of differential interactions between C. flaccumfaciens pv. flaccumfaciens isolates and common bean genotypes were identified by utilizing partial diallel analysis. The most aggressive isolates were BRM 14939 and BRM 14942 and the least aggressive isolates were BRM 14941 and BRM 14946. The genotypes IPA 9, Ouro Branco, and Michelite were selected as more resistant among the test isolates. The genotypes IAC Carioca Akytã, BRS Notável, Pérola, IAC Carioca Aruã, and Coquinho contributed more to the isolate x genotype interaction according to the ecovalence method of estimation, and were, therefore, indicated as differentials. Based on these results, it was possible to conclude that physiological races of the pathogen exist, to select resistant genotypes, and to propose a set of differentials.

Effects of functionally asexual reproduction on quantitative genetic variation in the evening primroses (Oenothera, Onagraceae).

PubMed

Godfrey, Ryan M; Johnson, Marc T J

2014-11-01

It has long been predicted that a loss of sexual reproduction leads to decreased heritable variation within populations and increased differentiation between populations. Despite an abundance of theory, there are few empirical tests of how sex affects genetic variation in phenotypic traits, especially for plants. Here we test whether repeated losses of two critical components of sex (recombination and segregation) in the evening primroses (Oenothera L., Onagraceae) affect quantitative genetic variation within and between populations. We sampled multiple genetic families from 3-5 populations from each of eight Oenothera species, which represented four independent transitions between sexual reproduction and a functionally asexual genetic system called "permanent translocation heterozygosity." We used quantitative genetics methods to partition genetic variation within and between populations for eight plant traits related to growth, leaf physiology, flowering, and resistance to herbivores. Heritability was, on average, 74% higher in sexual Oenothera populations than in functionally asexual populations, with plant growth rate, specific leaf area, and the percentage of leaf water content showing the strongest differences. By contrast, genetic differentiation among populations was 2.8× higher in functionally asexual vs. sexual Oenothera species. This difference was particularly strong for specific leaf area. Sexual populations tended to exhibit higher genetic correlations among traits, but this difference was weakly supported. These results support the prediction that sexual reproduction maintains higher genetic variation within populations, which may facilitate adaptive evolution. We also found partial support for the prediction that a loss of sex leads to greater population differentiation, which may elevate speciation rates. © 2014 Botanical Society of America, Inc.

Memory-enhancing effects of Cuscuta japonica Choisy via enhancement of adult hippocampal neurogenesis in mice.

PubMed

Moon, Minho; Jeong, Hyun Uk; Choi, Jin Gyu; Jeon, Seong Gak; Song, Eun Ji; Hong, Seon-Pyo; Oh, Myung Sook

2016-09-15

It is generally accepted that functional and structural changes within the hippocampus are involved in learning and memory and that adult neurogenesis in this region may modulate cognition. The extract of Cuscuta japonica Choisy (CJ) is a well-known traditional Chinese herbal medicine that has been used since ancient times as a rejuvenation remedy. The systemic effects of this herb are widely known and can be applied for the treatment of a number of physiological diseases, but there is a lack of evidence describing its effects on brain function. Thus, the present study investigated whether CJ would enhance memory function and/or increase hippocampal neurogenesis using mice orally administered with CJ water extract or vehicle for 21days. Performance on the novel object recognition and passive avoidance tests revealed that treatment with CJ dose-dependently improved the cognitive function of mice. Additionally, CJ increased the Ki-67-positive proliferating cells and the number of doublecortin-stained neuroblasts in the dentate gyrus (DG) of the hippocampus, and double labeling with 5-bromo-2-deoxyuridine and neuronal specific nuclear protein showed that CJ increased the number of mature neurons in the DG. Finally, CJ resulted in the upregulated expression of neurogenic differentiation factor, which is essential for the maturation and differentiation of granule cells in the hippocampus. Taken together, the present findings indicate that CJ stimulated neuronal cell proliferation, differentiation, and maturation, which are all processes associated with neurogenesis. Additionally, these findings suggest that CJ may improve learning and memory via the enhancement of adult hippocampal neurogenesis. Copyright © 2016 Elsevier B.V. All rights reserved.

The big and intricate dreams of little organelles: Embracing complexity in the study of membrane traffic.

PubMed

Liu, Allen P; Botelho, Roberto J; Antonescu, Costin N

2017-09-01

Compartmentalization of eukaryotic cells into dynamic organelles that exchange material through regulated membrane traffic governs virtually every aspect of cellular physiology including signal transduction, metabolism and transcription. Much has been revealed about the molecular mechanisms that control organelle dynamics and membrane traffic and how these processes are regulated by metabolic, physical and chemical cues. From this emerges the understanding of the integration of specific organellar phenomena within complex, multiscale and nonlinear regulatory networks. In this review, we discuss systematic approaches that revealed remarkable insight into the complexity of these phenomena, including the use of proximity-based proteomics, high-throughput imaging, transcriptomics and computational modeling. We discuss how these methods offer insights to further understand molecular versatility and organelle heterogeneity, phenomena that allow a single organelle population to serve a range of physiological functions. We also detail on how transcriptional circuits drive organelle adaptation, such that organelles may shift their function to better serve distinct differentiation and stress conditions. Thus, organelle dynamics and membrane traffic are functionally heterogeneous and adaptable processes that coordinate with higher-order system behavior to optimize cell function under a range of contexts. Obtaining a comprehensive understanding of organellar phenomena will increasingly require combined use of reductionist and system-based approaches. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Histamine and motivation

PubMed Central

Torrealba, Fernando; Riveros, Maria E.; Contreras, Marco; Valdes, Jose L.

2012-01-01

Brain histamine may affect a variety of different behavioral and physiological functions; however, its role in promoting wakefulness has overshadowed its other important functions. Here, we review evidence indicating that brain histamine plays a central role in motivation and emphasize its differential involvement in the appetitive and consummatory phases of motivated behaviors. We discuss the inputs that control histaminergic neurons of the tuberomamillary nucleus (TMN) of the hypothalamus, which determine the distinct role of these neurons in appetitive behavior, sleep/wake cycles, and food anticipatory responses. Moreover, we review evidence supporting the dysfunction of histaminergic neurons and the cortical input of histamine in regulating specific forms of decreased motivation (apathy). In addition, we discuss the relationship between the histamine system and drug addiction in the context of motivation. PMID:22783171

The differential effects of prolonged exercise upon executive function and cerebral oxygenation.

PubMed

Tempest, Gavin D; Davranche, Karen; Brisswalter, Jeanick; Perrey, Stephane; Radel, Rémi

2017-04-01

The acute-exercise effects upon cognitive functions are varied and dependent upon exercise duration and intensity, and the type of cognitive tasks assessed. The hypofrontality hypothesis assumes that prolonged exercise, at physiologically challenging intensities, is detrimental to executive functions due to cerebral perturbations (indicated by reduced prefrontal activity). The present study aimed to test this hypothesis by measuring oxygenation in prefrontal and motor regions using near-infrared spectroscopy during two executive tasks (flanker task and 2-back task) performed while cycling for 60min at a very low intensity and an intensity above the ventilatory threshold. Findings revealed that, compared to very low intensity, physiologically challenging exercise (i) shortened reaction time in the flanker task, (ii) impaired performance in the 2-back task, and (iii) initially increased oxygenation in prefrontal, but not motor regions, which then became stable in both regions over time. Therefore, during prolonged exercise, not only is the intensity of exercise assessed important, but also the nature of the cognitive processes involved in the task. In contrast to the hypofrontality hypothesis, no inverse pattern of oxygenation between prefrontal and motor regions was observed, and prefrontal oxygenation was maintained over time. The present results go against the hypofrontality hypothesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Cellular Metabolic and Autophagic Pathways: Traffic Control by Redox Signaling

PubMed Central

Dodson, Matthew; Darley-Usmar, Victor; Zhang, Jianhua

2013-01-01

It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality, and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function. PMID:23702245

Immunological function of vitamin D during human pregnancy.

PubMed

Ji, Jin-Lu; Muyayalo, Kahinho P; Zhang, Yong-Hong; Hu, Xiao-Hui; Liao, Ai-Hua

2017-08-01

The well-established classic role of vitamin D is implicated in the regulation of the balance between calcium and phosphorus. Furthermore, vitamin D is also involved in many non-classic physiological processes, mainly including the regulation of cell proliferation, differentiation, apoptosis and immune function, participation in the inflammatory response and maintenance of genome stability function. During pregnancy, vitamin D receptor and its metabolic enzymes are expressed at the placenta and decidua, indicating the potential role in the mechanism of immunomodulation at the maternal-fetal interface. The insufficiency or deficiency of vitamin D may affect the mother directly and is related to specific pregnancy outcomes, such as preeclampsia, gestational diabetes, and recurrent miscarriage. This article reviews the effects of vitamin D on immune regulation during pregnancy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Differential expression and emerging functions of non-coding RNAs in cold adaptation.

PubMed

Frigault, Jacques J; Morin, Mathieu D; Morin, Pier Jr

2017-01-01

Several species undergo substantial physiological and biochemical changes to confront the harsh conditions associated with winter. Small mammalian hibernators and cold-hardy insects are examples of natural models of cold adaptation that have been amply explored. While the molecular picture associated with cold adaptation has started to become clearer in recent years, notably through the use of high-throughput experimental approaches, the underlying cold-associated functions attributed to several non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), remain to be better characterized. Nevertheless, key pioneering work has provided clues on the likely relevance of these molecules in cold adaptation. With an emphasis on mammalian hibernation and insect cold hardiness, this work first reviews various molecular changes documented so far in these processes. The cascades leading to miRNA and lncRNA production as well as the mechanisms of action of these non-coding RNAs are subsequently described. Finally, we present examples of differentially expressed non-coding RNAs in models of cold adaptation and elaborate on the potential significance of this modulation with respect to low-temperature adaptation.

MED12 Regulates HSC-Specific Enhancers Independently of Mediator Kinase Activity to Control Hematopoiesis.

PubMed

Aranda-Orgilles, Beatriz; Saldaña-Meyer, Ricardo; Wang, Eric; Trompouki, Eirini; Fassl, Anne; Lau, Stephanie; Mullenders, Jasper; Rocha, Pedro P; Raviram, Ramya; Guillamot, María; Sánchez-Díaz, María; Wang, Kun; Kayembe, Clarisse; Zhang, Nan; Amoasii, Leonela; Choudhuri, Avik; Skok, Jane A; Schober, Markus; Reinberg, Danny; Sicinski, Piotr; Schrewe, Heinrich; Tsirigos, Aristotelis; Zon, Leonard I; Aifantis, Iannis

2016-12-01

Hematopoietic-specific transcription factors require coactivators to communicate with the general transcription machinery and establish transcriptional programs that maintain hematopoietic stem cell (HSC) self-renewal, promote differentiation, and prevent malignant transformation. Mediator is a large coactivator complex that bridges enhancer-localized transcription factors with promoters, but little is known about Mediator function in adult stem cell self-renewal and differentiation. We show that MED12, a member of the Mediator kinase module, is an essential regulator of HSC homeostasis, as in vivo deletion of Med12 causes rapid bone marrow aplasia leading to acute lethality. Deleting other members of the Mediator kinase module does not affect HSC function, suggesting kinase-independent roles of MED12. MED12 deletion destabilizes P300 binding at lineage-specific enhancers, resulting in H3K27Ac depletion, enhancer de-activation, and consequent loss of HSC stemness signatures. As MED12 mutations have been described recently in blood malignancies, alterations in MED12-dependent enhancer regulation may control both physiological and malignant hematopoiesis. Copyright © 2016 Elsevier Inc. All rights reserved.

Splicing factor SRSF3 is crucial for hepatocyte differentiation and metabolic function

PubMed Central

Sen, Supriya; Jumaa, Hassan; Webster, Nicholas J.G.

2015-01-01

SR family RNA binding proteins regulate splicing of nascent RNAs in vitro but their physiological role in vivo is largely unexplored, as genetic deletion of many SR protein genes results in embryonic lethality. Here we show that SRSF3HKO mice carrying a hepatocyte-specific deletion of Srsf3 (homologous to human SRSF3/SRp20) have a disrupted hepatic architecture and show pre- and postnatal growth retardation. SRSF3HKO mice exhibit impaired hepatocyte maturation with alterations in glucose and lipid homeostasis characterized by reduced glycogen storage, fasting hypoglycemia, increased insulin sensitivity and reduced cholesterol synthesis. We identify various splicing alterations in the SRSF3HKO liver that explain the in vivo phenotype. In particular, loss of SRSF3 causes aberrant splicing of Hnf1α, Ern1, Hmgcs1, Dhcr7 and Scap genes, which are critical regulators of glucose and lipid metabolism. Our study provides the first evidence for a SRSF3-driven genetic programme required for morphological and functional differentiation of hepatocytes that may have relevance for human liver disease and metabolic dysregulation. PMID:23299886

Neuroserpin Differentiates Between Forms of Tissue Type Plasminogen Activator via pH Dependent Deacylation

PubMed Central

Carlson, Karen-Sue B.; Nguyen, Lan; Schwartz, Kat; Lawrence, Daniel A.; Schwartz, Bradford S.

2016-01-01

Tissue-type plasminogen activator (t-PA), initially characterized for its critical role in fibrinolysis, also has key functions in both physiologic and pathologic processes in the CNS. Neuroserpin (NSP) is a t-PA specific serine protease inhibitor (serpin) found almost exclusively in the CNS that regulates t-PA’s proteolytic activity and protects against t-PA mediated seizure propagation and blood–brain barrier disruption. This report demonstrates that NSP inhibition of t-PA varies profoundly as a function of pH within the biologically relevant pH range for the CNS, and reflects the stability, rather than the formation of NSP: t-PA acyl-enzyme complexes. Moreover, NSP differentiates between the zymogen-like single chain form (single chain t-PA, sct-PA) and the mature protease form (two chain t-PA, tct-PA) of t-PA, demonstrating different pH profiles for protease inhibition, different pH ranges over which catalytic deacylation occurs, and different pH dependent profiles of deacylation rates for each form of t-PA. NSP’s pH dependent inhibition of t-PA is not accounted for by differential acylation, and is specific for the NSP-t-PA serpin-protease pair. These results demonstrate a novel mechanism for the differential regulation of the two forms of t-PA in the CNS, and suggest a potential specific regulatory role for CNS pH in controlling t-PA proteolytic activity. PMID:27378851

RNA-Seq and Gene Network Analysis Uncover Activation of an ABA-Dependent Signalosome During the Cork Oak Root Response to Drought

PubMed Central

Magalhães, Alexandre P.; Verde, Nuno; Reis, Francisca; Martins, Inês; Costa, Daniela; Lino-Neto, Teresa; Castro, Pedro H.; Tavares, Rui M.; Azevedo, Herlânder

2016-01-01

Quercus suber (cork oak) is a West Mediterranean species of key economic interest, being extensively explored for its ability to generate cork. Like other Mediterranean plants, Q. suber is significantly threatened by climatic changes, imposing the need to quickly understand its physiological and molecular adaptability to drought stress imposition. In the present report, we uncovered the differential transcriptome of Q. suber roots exposed to long-term drought, using an RNA-Seq approach. 454-sequencing reads were used to de novo assemble a reference transcriptome, and mapping of reads allowed the identification of 546 differentially expressed unigenes. These were enriched in both effector genes (e.g., LEA, chaperones, transporters) as well as regulatory genes, including transcription factors (TFs) belonging to various different classes, and genes associated with protein turnover. To further extend functional characterization, we identified the orthologs of differentially expressed unigenes in the model species Arabidopsis thaliana, which then allowed us to perform in silico functional inference, including gene network analysis for protein function, protein subcellular localization and gene co-expression, and in silico enrichment analysis for TFs and cis-elements. Results indicated the existence of extensive transcriptional regulatory events, including activation of ABA-responsive genes and ABF-dependent signaling. We were then able to establish that a core ABA-signaling pathway involving PP2C-SnRK2-ABF components was induced in stressed Q. suber roots, identifying a key mechanism in this species’ response to drought. PMID:26793200

Defining the Physiological Factors that Contribute to Postflight Changes in Functional Performance

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Arzeno, N.; Buxton, R.; Feiveson, A. H.; Kofman, I.; Lawrence, E.; Lee, S. M. C.; Mulavara, A. P.; Peters, B. T.; Platts, S. H.;

GENDER BASED DIFFERENCES IN ENDOCRINE AND REPRODUCTIVE TOXICITY

EPA Science Inventory

Basic differences in male versus female reproductive physiology lead to differentials in their respective susceptibilities to chemical insult as evidenced by a variety of observations. As individuals undergo maturation from prenatal sex differentiation through pubertal developme...

Human Enteroids as a Model of Upper Small Intestinal Ion Transport Physiology and Pathophysiology.

PubMed

Foulke-Abel, Jennifer; In, Julie; Yin, Jianyi; Zachos, Nicholas C; Kovbasnjuk, Olga; Estes, Mary K; de Jonge, Hugo; Donowitz, Mark

2016-03-01

Human intestinal crypt-derived enteroids are a model of intestinal ion transport that require validation by comparison with cell culture and animal models. We used human small intestinal enteroids to study neutral Na(+) absorption and stimulated fluid and anion secretion under basal and regulated conditions in undifferentiated and differentiated cultures to show their functional relevance to ion transport physiology and pathophysiology. Human intestinal tissue specimens were obtained from an endoscopic biopsy or surgical resections performed at Johns Hopkins Hospital. Crypts were isolated, enteroids were propagated in culture, induced to undergo differentiation, and transduced with lentiviral vectors. Crypt markers, surface cell enzymes, and membrane ion transporters were characterized using quantitative reverse-transcription polymerase chain reaction, immunoblot, or immunofluorescence analyses. We used multiphoton and time-lapse confocal microscopy to monitor intracellular pH and luminal dilatation in enteroids under basal and regulated conditions. Enteroids differentiated upon withdrawal of WNT3A, yielding decreased crypt markers and increased villus-like characteristics. Na(+)/H(+) exchanger 3 activity was similar in undifferentiated and differentiated enteroids, and was affected by known inhibitors, second messengers, and bacterial enterotoxins. Forskolin-induced swelling was completely dependent on cystic fibrosis transmembrane conductance regulator and partially dependent on Na(+)/H(+) exchanger 3 and Na(+)/K(+)/2Cl(-) cotransporter 1 inhibition in undifferentiated and differentiated enteroids. Increases in cyclic adenosine monophosphate with forskolin caused enteroid intracellular acidification in HCO3(-)-free buffer. Cyclic adenosine monophosphate-induced enteroid intracellular pH acidification as part of duodenal HCO3(-) secretion appears to require cystic fibrosis transmembrane conductance regulator and electrogenic Na(+)/HCO3(-) cotransporter 1. Undifferentiated or crypt-like, and differentiated or villus-like, human enteroids represent distinct points along the crypt-villus axis; they can be used to characterize electrolyte transport processes along the vertical axis of the small intestine. The duodenal enteroid model showed that electrogenic Na(+)/HCO3(-) cotransporter 1 might be a target in the intestinal mucosa for treatment of secretory diarrheas. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Transcriptome Network Analysis Reveals Aging-Related Mitochondrial and Proteasomal Dysfunction and Immune Activation in Human Thyroid

PubMed Central

Cho, Byuri Angela; Yoo, Seong-Keun; Song, Young Shin; Kim, Su-jin; Lee, Kyu Eun; Shong, Minho

2018-01-01

Background: Elucidating aging-related transcriptomic changes in human organs is necessary to understand the aging physiology and mechanisms, but little is known regarding the thyroid gland. We investigated aging-related transcriptomic alterations in the human thyroid gland and characterized the related molecular functions. Methods: Publicly available RNA sequencing data of 322 thyroid tissue samples from the Genotype-Tissue Expression project were analyzed. In addition, our own 64 RNA sequencing data of normal thyroid tissue samples were used as a validation set. To comprehensively evaluate the associations between aging and transcriptomic changes, we performed a weighted gene coexpression network analysis and pathway enrichment analysis. The thyroid differentiation score was then used for further analysis, defining the correlations between thyroid differentiation and aging. Results: The most significant aging-related transcriptomic change in thyroid was the downregulation of genes related to the mitochondrial and proteasomal functions (p = 3 × 10−6). Moreover, genes that are associated with immune processes were significantly upregulated with age (p = 3 × 10−4), and all of them overlapped with the upregulated genes in the thyroid glands affected by lymphocytic thyroiditis. Furthermore, these aging-related changes were not significantly different according to sex, but in terms of the thyroid differentiation, females were more susceptible to aging-related changes (p for trend = 0.03). Conclusions: Aging-related transcriptomic changes in the thyroid gland were associated with mitochondrial and proteasomal dysfunction, loss of differentiation, and activation of autoimmune processes. Our results provide clues to better understanding the age-related decline in thyroid function and higher susceptibility to autoimmune thyroid disease. PMID:29652618

Transcriptomic basis of functional difference and coordination between seeds and the silique wall of Brassica napus during the seed-filling stage.

PubMed

Liu, Han; Yang, Qingyong; Fan, Chuchuan; Zhao, Xiaoqin; Wang, Xuemin; Zhou, Yongming

2015-04-01

The silique of oilseed rape (Brassica napus) is a composite organ including seeds and the silique wall (SW) that possesses distinctly physiological, biochemical and functional differentiations. Yet, the molecular events controlling such differences between the SW and seeds, as well as their coordination during silique development at transcriptional level are largely unknown. Here, we identified large sets of differentially expressed genes in the SW and seeds of siliques at 21-22 days after flowering with a Brassica 95K EST microarray. At this particular stage, there were 3278 SW preferentially expressed genes and 2425 seed preferentially expressed genes. Using the MapMan visualization software, genes differentially regulated in various metabolic pathways and sub-pathways between the SW and seeds were revealed. Photosynthesis and transport-related genes were more actively transcripted in the SW, while those involved in lipid metabolism were more active in seeds during the seed filling stage. On the other hand, genes involved in secondary metabolisms were selectively regulated in the SW and seeds. Large numbers of transcription factors were identified to be differentially expressed between the SW and seeds, suggesting a complex pattern of transcriptional control in these two organs. Furthermore, most genes discussed in categories or pathways showed a similar expression pattern through 21 DAF to 42 DAF. Our results thus provide insights into the coordination of seeds and the SW in the developing silique at the transcriptional levels, which will facilitate the functional studies of important genes for improving B. napus seed productivity and quality. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Inorganic arsenic impairs differentiation and functions of human dendritic cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macoch, Mélinda; Morzadec, Claudie; Fardel, Olivier

2013-01-15

Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-γ and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 μM) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis.more » Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 μM) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-γ and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ► Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ► Arsenite (> 1 μM) blocks differentiation of dendritic cells by inducing necrosis ► Arsenite (0.1 to 0.5 μM) slightly reduces endocytotic activity of immature DCs ► Arsenite (0.1 to 0.5 μM) represses expression of IL-12p70 and IL-23 in activated DCs ► Arsenite (0.1 to 0.5 μM) reduces the ability of DCs to activate human T lymphocytes.« less

Analysis of Arterial Mechanics During Head-down Tilt Bed Rest

NASA Technical Reports Server (NTRS)

Elliot, Morgan; Martin, David S.; Westby, Christian M.; Stenger, Michael B.; Platts, Steve

2014-01-01

Arterial health may be affected by microgravity or ground based analogs of spaceflight, as shown by an increase in thoracic aorta stiffness1. Head-down tilt bed rest (HDTBR) is often used as a ground-based simulation of spaceflight because it induces physiological changes similar to those that occur in space2, 3. This abstract details an analysis of arterial stiffness (a subclinical measure of atherosclerosis), the distensibility coefficient (DC), and the pressure-strain elastic modulus (PSE) of the arterial walls during HDTBR. This project may help determine how spaceflight differentially affects arterial function in the upper vs. lower body.

Three-Dimensional Organotypic Co-Culture Model of Intestinal Epithelial Cells and Macrophages to Study "Salmonella Enterica" Colonization Patterns

NASA Technical Reports Server (NTRS)

Ott, Mark; Yang, J; Barilla, J.; Crabbe, A.; Sarker, S. F.; Liu, Y.

2017-01-01

Three-dimensional/3-D organotypic models of human intestinal epithelium mimic the differentiated form and function of parental tissues often not exhibited by 2-D monolayers and respond to Salmonella in ways that reflect in vivo infections. To further enhance the physiological relevance of 3-D models to more closely approximate in vivo intestinal microenvironments during infection, we developed and validated a novel 3-D intestinal co-culture model containing multiple epithelial cell types and phagocytic macrophages, and applied to study enteric infection by different Salmonella pathovars.

Transcriptome profiling and pathway analysis of genes expressed differentially in participants with or without a positive response to topiramate treatment for methamphetamine addiction.

PubMed

Li, Ming D; Wang, Ju; Niu, Tianhua; Ma, Jennie Z; Seneviratne, Chamindi; Ait-Daoud, Nassima; Saadvandi, Jim; Morris, Rana; Weiss, David; Campbell, Jan; Haning, William; Mawhinney, David J; Weis, Denis; McCann, Michael; Stock, Christopher; Kahn, Roberta; Iturriaga, Erin; Yu, Elmer; Elkashef, Ahmed; Johnson, Bankole A

2014-12-12

Developing efficacious medications to treat methamphetamine dependence is a global challenge in public health. Topiramate (TPM) is undergoing evaluation for this indication. The molecular mechanisms underlying its effects are largely unknown. Examining the effects of TPM on genome-wide gene expression in methamphetamine addicts is a clinically and scientifically important component of understanding its therapeutic profile. In this double-blind, placebo-controlled clinical trial, 140 individuals who met the DSM-IV criteria for methamphetamine dependence were randomized to receive either TPM or placebo, of whom 99 consented to participate in our genome-wide expression study. The RNA samples were collected from whole blood for 50 TPM- and 49 placebo-treated participants at three time points: baseline and the ends of weeks 8 and 12. Genome-wide expression profiles and pathways of the two groups were compared for the responders and non-responders at Weeks 8 and 12. To minimize individual variations, expression of all examined genes at Weeks 8 and 12 were normalized to the values at baseline prior to identification of differentially expressed genes and pathways. At the single-gene level, we identified 1054, 502, 204, and 404 genes at nominal P values < 0.01 in the responders vs. non-responders at Weeks 8 and 12 for the TPM and placebo groups, respectively. Among them, expression of 159, 38, 2, and 21 genes was still significantly different after Bonferroni corrections for multiple testing. Many of these genes, such as GRINA, PRKACA, PRKCI, SNAP23, and TRAK2, which are involved in glutamate receptor and GABA receptor signaling, are direct targets for TPM. In contrast, no TPM drug targets were identified in the 38 significant genes for the Week 8 placebo group. Pathway analyses based on nominally significant genes revealed 27 enriched pathways shared by the Weeks 8 and 12 TPM groups. These pathways are involved in relevant physiological functions such as neuronal function/synaptic plasticity, signal transduction, cardiovascular function, and inflammation/immune function. Topiramate treatment of methamphetamine addicts significantly modulates the expression of genes involved in multiple biological processes underlying addiction behavior and other physiological functions.

Temporal Impact of Substrate Mechanics on Differentiation of Human Embryonic Stem Cells to Cardiomyocytes

PubMed Central

Hazeltine, Laurie B.; Badur, Mehmet G.; Lian, Xiaojun; Das, Amritava; Han, Wenqing; Palecek, Sean P.

2014-01-01

A significant clinical need exists to differentiate human pluripotent stem cells (hPSCs) into cardiomyocytes, enabling tissue modeling for in vitro discovery of new drugs or cell-based therapies for heart repair in vivo. Chemical and mechanical microenvironmental factors are known to impact efficiency of stem cell differentiation, but cardiac differentiation protocols in hPSCs are typically performed on rigid tissue culture polystyrene (TCPS) surfaces which do not present a physiological mechanical setting. To investigate the temporal effects of mechanics on cardiac differentiation, we cultured human embryonic stem cells (hESCs) and their derivatives on polyacrylamide hydrogel substrates with a physiologically relevant range of stiffnesses. In directed differentiation and embryoid body culture systems, differentiation of hESCs to cardiac Troponin T-expressing (cTnT+) cardiomyocytes peaked on hydrogels of intermediate stiffness. Brachyury expression also peaked on intermediate stiffness hydrogels at day 1 of directed differentiation, suggesting that stiffness impacted the initial differentiation trajectory of hESCs to mesendoderm. To investigate the impact of substrate mechanics during cardiac specification of mesodermal progenitors, we initiated directed cardiomyocyte differentiation on TCPS and transferred cells to hydrogels at the Nkx2.5/Isl1+ cardiac progenitor cell stage. No differences in cardiomyocyte purity with stiffness were observed on day 15. These experiments indicate that differentiation of hESCs is sensitive to substrate mechanics at early stages of mesodermal induction, and proper application of substrate mechanics can increase the propensity of hESCs to differentiate to cardiomyocytes. PMID:24200714

Do sex, body size and reproductive condition influence the thermal preferences of a large lizard? A study in Tupinambis merianae.

PubMed

Cecchetto, Nicolas Rodolfo; Naretto, Sergio

2015-10-01

Body temperature is a key factor in physiological processes, influencing lizard performances; and life history traits are expected to generate variability of thermal preferences in different individuals. Gender, body size and reproductive condition may impose specific requirements on preferred body temperatures. If these three factors have different physiological functions and thermal requirements, then the preferred temperature may represent a compromise that optimizes these physiological functions. Therefore, the body temperatures that lizards select in a controlled environment may reflect a temperature that maximizes their physiological needs. The tegu lizard Tupinambis merianae is one of the largest lizards in South America and has wide ontogenetic variation in body size and sexual dimorphism. In the present study we evaluate intraspecific variability of thermal preferences of T. merianae. We determined the selected body temperature and the rate at which males and females attain their selected temperature, in relation to body size and reproductive condition. We also compared the behavior in the thermal gradient between males and females and between reproductive condition of individuals. Our study show that T. merianae selected body temperature within a narrow range of temperatures variation in the laboratory thermal gradient, with 36.24±1.49°C being the preferred temperature. We observed no significant differences between sex, body size and reproductive condition in thermal preferences. Accordingly, we suggest that the evaluated categories of T. merianae have similar thermal requirements. Males showed higher rates to obtain heat than females and reproductive females, higher rates than non-reproductive ones females. Moreover, males and reproductive females showed a more dynamic behavior in the thermal gradient. Therefore, even though they achieve the same selected temperature, they do it differentially. Copyright © 2015 Elsevier Ltd. All rights reserved.

Zymosan-induced immune challenge modifies the stress response of hypoxic air-breathing fish (Anabas testudineus Bloch): Evidence for reversed patterns of cortisol and thyroid hormone interaction, differential ion transporter functions and non-specific immune response.

PubMed

Simi, S; Peter, Valsa S; Peter, M C Subhash

2017-09-15

Fishes have evolved physiological mechanisms to exhibit stress response, where hormonal signals interact with an array of ion transporters and regulate homeostasis. As major ion transport regulators in fish, cortisol and thyroid hormones have been shown to interact and fine-tune the stress response. Likewise, in fishes many interactions have been identified between stress and immune components, but the physiological basis of such interaction has not yet delineated particularly in air-breathing fish. We, therefore, investigated the responses of thyroid hormones and cortisol, ion transporter functions and non-specific immune response of an obligate air-breathing fish Anabas testudineus Bloch to zymosan treatment or hypoxia stress or both, to understand how immune challenge modifies the pattern of stress response in this fish. Induction of experimental peritonitis in these fish by zymosan treatment (200ngg -1 ) for 24h produced rise in respiratory burst and lysozomal activities in head kidney phagocytes. In contrast, hypoxia stress for 30min in immune-challenged fish reversed these non-specific responses of head kidney phagocytes. The decline in plasma cortisol in zymosan-treated fish and its further suppression by hypoxia stress indicate that immune challenge suppresses the cortisol-driven stress response of this fish. Likewise, the decline in plasma T 3 and T 4 after zymosan-treatment and the rise in plasma T 4 after hypoxia stress in immune-challenged fish indicate a critical role for thyroid hormone in immune-stress response due to its differential sensitivity to both immune and stress challenges. Further, analysis of the activity pattern of ion-dependent ATPases viz. Na + /K + -ATPase, H + /K + -ATPase and Na + /NH 4 + -ATPase indicates a functional interaction of ion transport system with the immune response as evident in its differential and spatial modifications after hypoxia stress in immune-challenged fish. The immune-challenge that produced differential pattern of mRNA expression of Na + /K + -ATPase α-subunit isoforms; nkaα1a, nkaα1b and nkaα1c and the shift in nkaα1a and nkaα1b isoforms expression after hypoxia stress in immune-challenged fish, presents transcriptomic evidence for a modified Na + /K + ion transporter system in these fish. Collectively, our data thus provide evidence for an interactive immune-stress response in an air-breathing fish, where the patterns of cortisol-thyroid hormone interaction, the ion transporter functions and the non-specific immune responses are reversed by hypoxia stress in immune-challenged fish. Copyright © 2016 Elsevier Inc. All rights reserved.

Physiological Factors Contributing to Postflight Changes in Functional Performance

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Feedback, D. L.; Feiverson, A. H.; Lee, S. M. C.; Mulavara, A. P.; Peters, B. T.; Platts, S. H.; Reschke, M. F.; Ryder, J.; Spiering, B. A.;

Role of physiological levels of 4-hydroxynonenal on adipocyte biology: implications for obesity and metabolic syndrome.

PubMed

Dasuri, Kalavathi; Ebenezer, Philip; Fernandez-Kim, Sun Ok; Zhang, Le; Gao, Zhanguo; Bruce-Keller, Annadora J; Freeman, Linnea R; Keller, Jeffrey N

2013-01-01

Lipid peroxidation products such as 4-hydroxynonenal (HNE) are known to be increased in response to oxidative stress, and are known to cause dysfunction and pathology in a variety of tissues during periods of oxidative stress. The aim of the current study was to determine the chronic (repeated HNE exposure) and acute effects of physiological concentrations of HNE toward multiple aspects of adipocyte biology using differentiated 3T3-L1 adipocytes. Our studies demonstrate that acute and repeated exposure of adipocytes to physiological concentrations of HNE is sufficient to promote subsequent oxidative stress, impaired adipogenesis, alter the expression of adipokines, and increase lipolytic gene expression and subsequent increase in free fatty acid (FFA) release. These results provide an insight in to the role of HNE-induced oxidative stress in regulation of adipocyte differentiation and adipose dysfunction. Taken together, these data indicate a potential role for HNE promoting diverse effects toward adipocyte homeostasis and adipocyte differentiation, which may be important to the pathogenesis observed in obesity and metabolic syndrome.

Functionality of empirical model-based predictive analytics for the early detection of hemodynamic instabilty.

PubMed

Summers, Richard L; Pipke, Matt; Wegerich, Stephan; Conkright, Gary; Isom, Kristen C

2014-01-01

Background. Monitoring cardiovascular hemodynamics in the modern clinical setting is a major challenge. Increasing amounts of physiologic data must be analyzed and interpreted in the context of the individual patient’s pathology and inherent biologic variability. Certain data-driven analytical methods are currently being explored for smart monitoring of data streams from patients as a first tier automated detection system for clinical deterioration. As a prelude to human clinical trials, an empirical multivariate machine learning method called Similarity-Based Modeling (“SBM”), was tested in an In Silico experiment using data generated with the aid of a detailed computer simulator of human physiology (Quantitative Circulatory Physiology or “QCP”) which contains complex control systems with realistic integrated feedback loops. Methods. SBM is a kernel-based, multivariate machine learning method that that uses monitored clinical information to generate an empirical model of a patient’s physiologic state. This platform allows for the use of predictive analytic techniques to identify early changes in a patient’s condition that are indicative of a state of deterioration or instability. The integrity of the technique was tested through an In Silico experiment using QCP in which the output of computer simulations of a slowly evolving cardiac tamponade resulted in progressive state of cardiovascular decompensation. Simulator outputs for the variables under consideration were generated at a 2-min data rate (0.083Hz) with the tamponade introduced at a point 420 minutes into the simulation sequence. The functionality of the SBM predictive analytics methodology to identify clinical deterioration was compared to the thresholds used by conventional monitoring methods. Results. The SBM modeling method was found to closely track the normal physiologic variation as simulated by QCP. With the slow development of the tamponade, the SBM model are seen to disagree while the simulated biosignals in the early stages of physiologic deterioration and while the variables are still within normal ranges. Thus, the SBM system was found to identify pathophysiologic conditions in a timeframe that would not have been detected in a usual clinical monitoring scenario. Conclusion. In this study the functionality of a multivariate machine learning predictive methodology that that incorporates commonly monitored clinical information was tested using a computer model of human physiology. SBM and predictive analytics were able to differentiate a state of decompensation while the monitored variables were still within normal clinical ranges. This finding suggests that the SBM could provide for early identification of a clinical deterioration using predictive analytic techniques. predictive analytics, hemodynamic, monitoring.

Differentiating a network of executive attention: LORETA neurofeedback in anterior cingulate and dorsolateral prefrontal cortices.

PubMed

Cannon, Rex; Congedo, Marco; Lubar, Joel; Hutchens, Teresa

2009-01-01

This study examines the differential effects of space-specific neuro-operant learning, utilizing low-resolution electromagnetic tomographic (LORETA) neurofeedback in three regions of training (ROTs), namely, the anterior cingulate gyrus (AC) and right and left dorsolateral prefrontal cortices (RPFC and LPFC respectively). This study was conducted with 14 nonclinical students with a mean age of 22. We utilized electrophysiological measurements and subtests of the WAIS-III for premeasures and postmeasures. The data indicate that the AC shares a significant association with the RPFC and LPFC; however, each of the ROTs exhibits different cortical effects in all frequencies when trained exclusively. LORETA neurofeedback (LNFB) appears to enhance the functioning and strengthening of networks of cortical units physiologically related to each ROT; moreover, significant changes are mapped for each frequency domain, showing the associations within this possible attentional network.

Chronology of endocrine differentiation and beta-cell neogenesis.

PubMed

Miyatsuka, Takeshi

2016-01-01

Diabetes is a chronic and incurable disease, which results from absolute or relative insulin insufficiency. Therefore, pancreatic beta cells, which are the only type of cell that expresses insulin, is considered to be a potential target for the cure of diabetes. Although the findings regarding beta-cell neogenesis during pancreas development have been exploited to induce insulin-producing cells from non-beta cells, there are still many hurdles towards generating fully functional beta cells that can produce high levels of insulin and respond to physiological signals. To overcome these problems, a solid understanding of pancreas development and beta-cell formation is required, and several mouse models have been developed to reveal the unique features of each endocrine cell type at distinct developmental time points. Here I review our understanding of pancreas development and endocrine differentiation focusing on recent progresses in improving temporal cell labeling in vivo.

EZH2 is required for germinal center formation and somatic EZH2 mutations promote lymphoid transformation

PubMed Central

Béguelin, Wendy; Popovic, Relja; Teater, Matt; Jiang, Yanwen; Bunting, Karen L.; Rosen, Monica; Shen, Hao; Yang, Shao Ning; Wang, Ling; Ezponda, Teresa; Martinez-Garcia, Eva; Zhang, Haikuo; Zhang, Yupeng; Verma, Sharad K.; McCabe, Michael T.; Ott, Heidi M.; Van Aller, Glenn S.; Kruger, Ryan G.; Liu, Yan; McHugh, Charles F.; Scott, David W.; Chung, Young Rock; Kelleher, Neil; Shaknovich, Rita; Creasy, Caretha L.; Gascoyne, Randy D.; Wong, Kwok-Kin; Cerchietti, Leandro C.; Levine, Ross L.; Abdel-Wahab, Omar; Licht, Jonathan D.; Elemento, Olivier; Melnick, Ari M.

2013-01-01

The EZH2 histone methyltransferase is highly expressed in germinal center (GC) B-cells and targeted by somatic mutations in B-cell lymphomas. Here we find that EZH2 deletion or pharmacologic inhibition suppresses GC formation and functions in mice. EZH2 represses proliferation checkpoint genes and helps establish bivalent chromatin domains at key regulatory loci to transiently suppress GC B-cell differentiation. Somatic mutations reinforce these physiological effects through enhanced silencing of EZH2 targets in B-cells, and in human B-cell lymphomas. Conditional expression of mutant EZH2 in mice induces GC hyperplasia and accelerated lymphomagenesis in cooperation with BCL2. GCB-type DLBCLs are mostly addicted to EZH2, regardless of mutation status, but not the more differentiated ABC-type DLBCLs, thus clarifying the therapeutic scope of EZH2 targeting. PMID:23680150

Differential proteomics of human seminal plasma: A potential target for searching male infertility marker proteins.

PubMed

Tomar, Anil Kumar; Sooch, Balwinder Singh; Singh, Sarman; Yadav, Savita

2012-04-01

The clinical fertility tests, available in the market, fail to define the exact cause of male infertility in almost half of the cases and point toward a crucial need of developing better ways of infertility investigations. The protein biomarkers may help us toward better understanding of unknown cases of male infertility that, in turn, can guide us to find better therapeutic solutions. Many clinical attempts have been made to identify biomarkers of male infertility in sperm proteome but only few studies have targeted seminal plasma. Human seminal plasma is a rich source of proteins that are essentially required for development of sperm and successful fertilization. This viewpoint article highlights the importance of human seminal plasma proteome in reproductive physiology and suggests that differential proteomics integrated with functional analysis may help us in searching potential biomarkers of male infertility. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cholangiocytes derived from human induced pluripotent stem cells for disease modeling and drug validation.

PubMed

Sampaziotis, Fotios; de Brito, Miguel Cardoso; Madrigal, Pedro; Bertero, Alessandro; Saeb-Parsy, Kourosh; Soares, Filipa A C; Schrumpf, Elisabeth; Melum, Espen; Karlsen, Tom H; Bradley, J Andrew; Gelson, William Th; Davies, Susan; Baker, Alastair; Kaser, Arthur; Alexander, Graeme J; Hannan, Nicholas R F; Vallier, Ludovic

2015-08-01

The study of biliary disease has been constrained by a lack of primary human cholangiocytes. Here we present an efficient, serum-free protocol for directed differentiation of human induced pluripotent stem cells into cholangiocyte-like cells (CLCs). CLCs show functional characteristics of cholangiocytes, including bile acids transfer, alkaline phosphatase activity, γ-glutamyl-transpeptidase activity and physiological responses to secretin, somatostatin and vascular endothelial growth factor. We use CLCs to model in vitro key features of Alagille syndrome, polycystic liver disease and cystic fibrosis (CF)-associated cholangiopathy. Furthermore, we use CLCs generated from healthy individuals and patients with polycystic liver disease to reproduce the effects of the drugs verapamil and octreotide, and we show that the experimental CF drug VX809 rescues the disease phenotype of CF cholangiopathy in vitro. Our differentiation protocol will facilitate the study of biological mechanisms controlling biliary development, as well as disease modeling and drug screening.

The Effects of Orbital Spaceflight on Human Osteoblastic Cell Physiology and Gene Expression

NASA Technical Reports Server (NTRS)

Turner, R. T.

1999-01-01

The purpose of the proposed study is to establish whether changes in gravitational loading have a direct effect on osteoblasts to regulate TGF-6 expression. The effects of spaceflight and reloading on TGF-B MRNA and peptide levels will be studied in a newly developed line of immortalized human fetal osteoblasts (HFOB) transfected with an SV-40 temperature dependent mutant to generate proliferating, undifferentiated hFOB cells at 33-34 C and a non-proliferating, differentiated HFOB cells at 37-39'C. Unlike previous cell culture models, HFOB cells have unlimited proliferative capacity yet can be precisely regulated to differentiate into mature cells which express mature osteoblast function. If isolated osteoblasts respond to changes in mechanical loading in a manner similar to their response in animals, the cell system could provide a powerful model to investigate the signal transduction pathway for gravitational loading.

Biomimetic engineered muscle with capacity for vascular integration and functional maturation in vivo

PubMed Central

Juhas, Mark; Engelmayr, George C.; Fontanella, Andrew N.; Palmer, Gregory M.; Bursac, Nenad

2014-01-01

Tissue-engineered skeletal muscle can serve as a physiological model of natural muscle and a potential therapeutic vehicle for rapid repair of severe muscle loss and injury. Here, we describe a platform for engineering and testing highly functional biomimetic muscle tissues with a resident satellite cell niche and capacity for robust myogenesis and self-regeneration in vitro. Using a mouse dorsal window implantation model and transduction with fluorescent intracellular calcium indicator, GCaMP3, we nondestructively monitored, in real time, vascular integration and the functional state of engineered muscle in vivo. During a 2-wk period, implanted engineered muscle exhibited a steady ingrowth of blood-perfused microvasculature along with an increase in amplitude of calcium transients and force of contraction. We also demonstrated superior structural organization, vascularization, and contractile function of fully differentiated vs. undifferentiated engineered muscle implants. The described in vitro and in vivo models of biomimetic engineered muscle represent enabling technology for novel studies of skeletal muscle function and regeneration. PMID:24706792

CREB at the Crossroads of Activity-Dependent Regulation of Nervous System Development and Function.

PubMed

Belgacem, Yesser H; Borodinsky, Laura N

2017-01-01

The central nervous system is a highly plastic network of cells that constantly adjusts its functions to environmental stimuli throughout life. Transcription-dependent mechanisms modify neuronal properties to respond to external stimuli regulating numerous developmental functions, such as cell survival and differentiation, and physiological functions such as learning, memory, and circadian rhythmicity. The discovery and cloning of the cyclic adenosine monophosphate (cAMP) responsive element binding protein (CREB) constituted a big step toward deciphering the molecular mechanisms underlying neuronal plasticity. CREB was first discovered in learning and memory studies as a crucial mediator of activity-dependent changes in target gene expression that in turn impose long-lasting modifications of the structure and function of neurons. In this chapter, we review the molecular and signaling mechanisms of neural activity-dependent recruitment of CREB and its cofactors. We discuss the crosstalk between signaling pathways that imprints diverse spatiotemporal patterns of CREB activation allowing for the integration of a wide variety of stimuli.

On the Evolution of the Pulmonary Alveolar Lipofibroblast

PubMed Central

Torday, John S.; Rehan, Virender K.

2015-01-01

The pulmonary alveolar lipofibroblast was first reported in 1970. Since then its development, structure, function and molecular characteristics have been determined. Its capacity to actively absorb, store and ‘traffic’ neutral lipid for protection of the alveolus against oxidant injury, and for the active supply of substrate for lung surfactant phospholipid production have offered the opportunity to identify a number of specialized functions of these strategically placed cells. Namely, Parathyroid Hormone-related Protein (PTHrP) signaling, expression of Adipocyte Differentiation Related Protein, leptin, peroxisome proliferator activator receptor gamma, and the prostaglandin E2 receptor EP2-which are all stretch-regulated, explaining how and why surfactant production is ‘on-demand’ in service to ventilation-perfusion matching. Because of the central role of the lipofibroblast in vertebrate lung physiologic evolution, it is a Rosetta Stone for understanding how and why the lung evolved in adaptation to terrestrial life, beginning with the duplication of the PTHrP Receptor some 300 mya. Moreover, such detailed knowledge of the workings of the lipofibroblast have provided insight to the etiology and effective treatment of Bronchopulmonary Dysplasia based on physiologic principles rather than on pharmacology. PMID:26706109

Major amyloid-β-degrading enzymes, endothelin-converting enzyme-2 and neprilysin, are expressed by distinct populations of GABAergic interneurons in hippocampus and neocortex.

PubMed

Pacheco-Quinto, Javier; Eckman, Christopher B; Eckman, Elizabeth A

2016-12-01

Impaired clearance of amyloid-β peptide (Aβ) has been postulated to significantly contribute to the amyloid accumulation typical of Alzheimer's disease. Among the enzymes known to degrade Aβ in vivo are endothelin-converting enzyme (ECE)-1, ECE-2, and neprilysin (NEP), and evidence suggests that they regulate independent pools of Aβ that may be functionally significant. To better understand the differential regulation of Aβ concentration by its physiological degrading enzymes, we characterized the cell and region-specific expression pattern of ECE-1, ECE-2, and NEP by in situ hybridization and immunohistochemistry in brain areas relevant to Alzheimer's disease. In contrast to the broader distribution of ECE-1, ECE-2 and NEP were found enriched in GABAergic neurons. ECE-2 was majorly expressed by somatostatin-expressing interneurons and was active in isolated synaptosomes. NEP messenger RNA was found mainly in parvalbumin-expressing interneurons, with NEP protein localized to perisomatic parvalbuminergic synapses. The identification of somatostatinergic and parvalbuminergic synapses as hubs for Aβ degradation is consistent with the possibility that Aβ may have a physiological function related to the regulation of inhibitory signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

Dynamics between actin and the VE-cadherin/catenin complex

PubMed Central

Abu Taha, Abdallah; Schnittler, Hans-J

2014-01-01

Endothelial adherens junctions are critical for physiological and pathological processes such as differentiation, maintenance of entire monolayer integrity, and the remodeling. The endothelial-specific VE-cadherin/catenin complex provides the backbone of adherens junctions and acts in close interaction with actin filaments and actin/myosin-mediated contractility to fulfill the junction demands. The functional connection between the cadherin/catenin complex and actin filaments might be either directly through α-catenins, or indirectly e.g., via linker proteins such as vinculin, p120ctn, α-actinin, or EPLIN. However, both junction integrity and dynamic remodeling have to be contemporarily coordinated. The actin-related protein complex ARP2/3 and its activating molecules, such as N-WASP and WAVE, have been shown to regulate the lammellipodia-mediated formation of cell junctions in both epithelium and endothelium. Recent reports now demonstrate a novel aspect of the ARP2/3 complex and the nucleating-promoting factors in the maintenance of endothelial barrier function and junction remodeling of established endothelial cell junctions. Those mechanisms open novel possibilities; not only in fulfilling physiological demands but obtained information may be of critical importance in pathologies such as wound healing, angiogenesis, inflammation, and cell diapedesis. PMID:24621569

Co-regulation of primary mouse hepatocyte viability and function by oxygen and matrix.

PubMed

Buck, Lorenna D; Inman, S Walker; Rusyn, Ivan; Griffith, Linda G

2014-05-01

Although oxygen and extracellular matrix cues both influence differentiation state and metabolic function of primary rat and human hepatocytes, relatively little is known about how these factors together regulate behaviors of primary mouse hepatocytes in culture. To determine the effects of pericellular oxygen tension on hepatocellular function, we employed two methods of altering oxygen concentration in the local cellular microenvironment of cells cultured in the presence or absence of an extracellular matrix (Matrigel) supplement. By systematically altering medium depth and gas phase oxygen tension, we created multiple oxygen regimes (hypoxic, normoxic, and hyperoxic) and measured the local oxygen concentrations in the pericellular environment using custom-designed oxygen microprobes. From these measurements of oxygen concentrations, we derived values of oxygen consumption rates under a spectrum of environmental contexts, thus providing the first reported estimates of these values for primary mouse hepatocytes. Oxygen tension and matrix microenvironment were found to synergistically regulate hepatocellular survival and function as assessed using quantitative image analysis for cells stained with vital dyes, and assessment of secretion of albumin. Hepatocellular viability was affected only at strongly hypoxic conditions. Surprisingly, albumin secretion rates were greatest at a moderately supra-physiological oxygen concentration, and this effect was mitigated at still greater supra-physiological concentrations. Matrigel enhanced the effects of oxygen on retention of function. This study underscores the importance of carefully controlling cell density, medium depth, and gas phase oxygen, as the effects of these parameters on local pericellular oxygen tension and subsequent hepatocellular function are profound. © 2014 Wiley Periodicals, Inc.

Phenotypic plasticity and population differentiation in response to salinity in the invasive cordgrass Spartina densiflora

USDA-ARS?s Scientific Manuscript database

Salinity and tidal inundation induce physiological stress in vascular plant species and influence their distribution and productivity in estuarine wetlands. Climate change-induced sea level rise is magnifying these abiotic stressors and the physiological stresses they cause. Understanding the pote...

The pathologic physiology of chronic Bright's disease. An exposition of the "intact nephron hypothesis".

PubMed

Bricker, N S; Morrin, P A; Kime, S W

1997-09-01

Clinical and experimental data relating to the functional capacity of the surviving nephrons of the chronically diseased kidney for the most part support the thesis that these nephrons retain their essential functional integrity regardless of the nature of the underlying form of chronic Bright's disease. There are instances in which specific alterations of function correlate with pathologic involvement of a particular site of the nephron but these appear to represent the exceptions, and in general the more advanced the disease becomes, the less evident are the differentiating features. Studies on dogs with unilateral renal disease indicate that the functional capacity of the nephrons of the diseased kidney parallels that of the nephrons of the contralateral normal kidney. These data tend to exclude widespread intrinsic damage to the functioning nephrons by the underlying pathologic processes. From these observations, as well as from certain supporting clinical and experimental observations, it is suggested that the majority of surviving nephrons in the patient with bilateral renal disease similarly are functionally intact. Concepts of the pathologic physiology of the kidney, based on the "intact nephron hypothesis", are presented. Within the framework of this hypothesis it is concluded that (1) the diseased kidney consists of a diminished number of nephrons, most of which retain essentially normal functional abilities; (2) certain of the apparent abnormalities in function in bilateral renal disease may relate to adaptive changes imposed by the decreased nephron population and the attendant derangements in body fluids rather than to structural distortion of nephrons; (3) the over-all flexibility of the diseased kidney decreases as the number of constituent nephrons decreases; but (4) there is an orderly and predictable pattern of excretion for all substances.

Music exposure differentially alters the levels of brain-derived neurotrophic factor and nerve growth factor in the mouse hypothalamus.

PubMed

Angelucci, Francesco; Ricci, Enzo; Padua, Luca; Sabino, Andrea; Tonali, Pietro Attilio

2007-12-18

It has been reported that music may have physiological effects on blood pressure, cardiac heartbeat, respiration, and improve mood state in people affected by anxiety, depression and other psychiatric disorders. However, the physiological bases of these phenomena are not clear. Hypothalamus is a brain region involved in the regulation of body homeostasis and in the pathophysiology of anxiety and depression through the modulation of hypothalamic-pituitary-adrenal (HPA) axis. Hypothalamic functions are also influenced by the presence of the neurotrophins brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), which are proteins involved in the growth, survival and function of neurons in the central nervous system. The aim of this study was to investigate the effect of music exposure in mice on hypothalamic levels of BDNF and NGF. We exposed young adult mice to slow rhythm music (6h per day; mild sound pressure levels, between 50 and 60 dB) for 21 consecutive days. At the end of the treatment mice were sacrificed and BDNF and NGF levels in the hypothalamus were measured by enzyme-linked immunosorbent assay (ELISA). We found that music exposure significantly enhanced BDNF levels in the hypothalamus. Furthermore, we observed that music-exposed mice had decreased NGF hypothalamic levels. Our results demonstrate that exposure to music in mice can influence neurotrophin production in the hypothalamus. Our findings also suggest that physiological effects of music might be in part mediated by modulation of neurotrophins.

Developmentally regulated HEART STOPPER, a mitochondrially targeted L18 ribosomal protein gene, is required for cell division, differentiation, and seed development in Arabidopsis

PubMed Central

Zhang, Hongyu; Luo, Ming; Day, Robert C.; Talbot, Mark J.; Ivanova, Aneta; Ashton, Anthony R.; Chaudhury, Abed M.; Macknight, Richard C.; Hrmova, Maria; Koltunow, Anna M.

2015-01-01

Evidence is presented for the role of a mitochondrial ribosomal (mitoribosomal) L18 protein in cell division, differentiation, and seed development after the characterization of a recessive mutant, heart stopper (hes). The hes mutant produced uncellularized endosperm and embryos arrested at the late globular stage. The mutant embryos differentiated partially on rescue medium with some forming callus. HES (At1g08845) encodes a mitochondrially targeted member of a highly diverged L18 ribosomal protein family. The substitution of a conserved amino residue in the hes mutant potentially perturbs mitoribosomal function via altered binding of 5S rRNA and/or influences the stability of the 50S ribosomal subunit, affecting mRNA binding and translation. Consistent with this, marker genes for mitochondrial dysfunction were up-regulated in the mutant. The slow growth of the endosperm and embryo indicates a defect in cell cycle progression, which is evidenced by the down-regulation of cell cycle genes. The down-regulation of other genes such as EMBRYO DEFECTIVE genes links the mitochondria to the regulation of many aspects of seed development. HES expression is developmentally regulated, being preferentially expressed in tissues with active cell division and differentiation, including developing embryos and the root tips. The divergence of the L18 family, the tissue type restricted expression of HES, and the failure of other L18 members to complement the hes phenotype suggest that the L18 proteins are involved in modulating development. This is likely via heterogeneous mitoribosomes containing different L18 members, which may result in differential mitochondrial functions in response to different physiological situations during development. PMID:26105995

From chemical neuroanatomy to an understanding of the olfactory system

PubMed Central

Oboti, L.; Peretto, P.; De Marchis, S.; Fasolo, A.

2011-01-01

The olfactory system of mammals is the appropriate model for studying several aspects of neuronal physiology spanning from the developmental stage to neural network remodelling in the adult brain. Both the morphological and physiological understanding of this system were strongly supported by classical histochemistry. It is emblematic the case of the Olfactory Marker Protein (OMP) staining, the first, powerful marker for fully differentiated olfactory receptor neurons and a key tool to investigate the dynamic relations between peripheral sensory epithelia and central relay regions given its presence within olfactory fibers reaching the olfactory bulb (OB). Similarly, the use of thymidine analogues was able to show neurogenesis in an adult mammalian brain far before modern virus labelling and lipophilic tracers based methods. Nowadays, a wealth of new histochemical techniques combining cell and molecular biology approaches is available, giving stance to move from the analysis of the chemically identified circuitries to functional research. The study of adult neurogenesis is indeed one of the best explanatory examples of this statement. After defining the cell types involved and the basic physiology of this phenomenon in the OB plasticity, we can now analyze the role of neurogenesis in well testable behaviours related to socio-chemical communication in rodents. PMID:22297441

Intermediate filament proteins of digestive organs: physiology and pathophysiology.

PubMed

Omary, M Bishr

2017-06-01

Intermediate filament proteins (IFs), such as cytoplasmic keratins in epithelial cells and vimentin in mesenchymal cells and the nuclear lamins, make up one of the three major cytoskeletal protein families. Whether in digestive organs or other tissues, IFs share several unique features including stress-inducible overexpression, abundance, cell-selective and differentiation state expression, and association with >80 human diseases when mutated. Whereas most IF mutations cause disease, mutations in simple epithelial keratins 8, 18, or 19 or in lamin A/C predispose to liver disease with or without other tissue manifestations. Keratins serve major functions including protection from apoptosis, providing cellular and subcellular mechanical integrity, protein targeting to subcellular compartments, and scaffolding and regulation of cell-signaling processes. Keratins are essential for Mallory-Denk body aggregate formation that occurs in association with several liver diseases, whereas an alternate type of keratin and lamin aggregation occurs upon liver involvement in porphyria. IF-associated diseases have no known directed therapy, but high-throughput drug screening to identify potential therapies is an appealing ongoing approach. Despite the extensive current knowledge base, much remains to be discovered regarding IF physiology and pathophysiology in digestive and nondigestive organs. Copyright © 2017 the American Physiological Society.

Effect of intermittent standing and walking on physiological changes induced by head-down bed rest

NASA Technical Reports Server (NTRS)

Vernikos, J.; Ludwig, D. A.; Ertl, A. C.; Wade, C. E.; Keil, L.; OHara, D.

1994-01-01

Continuous exposure to gravity may not be necessary to prevent compromised physiological function resulting from exposure to microgravity. However, minimum gravity (G) exposure requirements, effectiveness of passive Gz versus activity in a G field, and optimal G stimulus amplitude, duration, and frequency are unknown. To partially address these questions, a 4-day, 6 degree head-down bed rest (HDBR) study (one ambulatory control day, 4 full HDBR days, one recovery day) was conducted. Nine males, 30-50 yr, were subjected to four different +1 Gz (head-foot) exposure protocols (periodic standing or controlled walking for 2 or 4 h/day in 15 min doses), plus a continuous HDBR (0 Gz) control. Standing 4 h completely prevented and standing 2 h partially prevented post-HDBR orthostatic intolerance. Both walking conditions (2 h and 4 h) attenuated the decrease in peak VO2 and prevented the increased urinary Ca2+ excretion associated with HDBR. Both 4 h conditions (standing and walking) attenuated plasma volume loss during HDBR. It was concluded that various physiological systems benefit differentially from passive +1 Gz or activity in +1 Gz and the duration (2 h vs. 4 h) of the stimulus may be an important moderating factor.

The Role of Gap Junction Channels During Physiologic and Pathologic Conditions of the Human Central Nervous System

PubMed Central

Basilio, Daniel; Sáez, Juan C.; Orellana, Juan A.; Raine, Cedric S.; Bukauskas, Feliksas; Bennett, Michael V. L.; Berman, Joan W.

2013-01-01

Gap junctions (GJs) are expressed in most cell types of the nervous system, including neuronal stem cells, neurons, astrocytes, oligodendrocytes, cells of the blood brain barrier (endothelial cells and astrocytes) and under inflammatory conditions in microglia/macrophages. GJs connect cells by the docking of two hemichannels, one from each cell with each hemichannel being formed by 6 proteins named connexins (Cx). Unapposed hemichannels (uHC) also can be open on the surface of the cells allowing the release of different intracellular factors to the extracellular space. GJs provide a mechanism of cell-to-cell communication between adjacent cells that enables the direct exchange of intracellular messengers, such as calcium, nucleotides, IP3, and diverse metabolites, as well as electrical signals that ultimately coordinate tissue homeostasis, proliferation, differentiation, metabolism, cell survival and death. Despite their essential functions in physiological conditions, relatively little is known about the role of GJs and uHC in human diseases, especially within the nervous system. The focus of this review is to summarize recent findings related to the role of GJs and uHC in physiologic and pathologic conditions of the central nervous system. PMID:22438035

Visualization and contractile activity of cochlear pericytes in the capillaries of the spiral ligament.

PubMed

Dai, Min; Nuttall, Alfred; Yang, Yue; Shi, Xiaorui

2009-08-01

Pericytes, mural cells located on microvessels, are considered to play an important role in the formation of the vasculature and the regulation of local blood flow in some organs. Little is known about the physiology of cochlear pericytes. In order to investigate the function of cochlear pericytes, we developed a method to visualize cochlear pericytes using diaminofluorescein-2 diacetate (DAF-2DA) and intravital fluorescence microscopy. This method can permit the study of the effect of vasoactive agents on pericytes under the in vivo and normal physiological condition. The specificity of the labeling method was verified by the immunofluorescence labeling of pericyte maker proteins such as desmin, neural proteoglycan (NG2), and thymocyte differentiation antigen 1 (Thy-1). Superfused K(+) and Ca(2+) to the cochlear lateral wall resulted in localized constriction of capillaries at pericyte locations both in vivo and in vitro, while there was no obvious change in cochlear capillary diameters with application of the adrenergic neurotransmitter noradrenaline. The method could be an effective way to visualize cochlear pericytes and microvessels and study lateral wall vascular physiology. Moreover, we demonstrate for the first time that cochlear pericytes have contractility, which may be important for regulation of cochlear blood flow.

Developing rods transplanted into the degenerating retina of Crx-knockout mice exhibit neural activity similar to native photoreceptors

PubMed Central

Homma, Kohei; Okamoto, Satoshi; Mandai, Michiko; Gotoh, Norimoto; Rajasimha, Harsha K.; Chang, Yi-Sheng; Chen, Shan; Li, Wei; Cogliati, Tiziana; Swaroop, Anand; Takahashi, Masayo

2013-01-01

Replacement of dysfunctional or dying photoreceptors offers a promising approach for retinal neurodegenerative diseases, including age-related macular degeneration and retinitis pigmentosa. Several studies have demonstrated the integration and differentiation of developing rod photoreceptors when transplanted in wild type or degenerating retina; however, the physiology and function of the donor cells are not adequately defined. Here, we describe the physiological properties of developing rod photoreceptors that are tagged with GFP driven by the promoter of rod differentiation factor, Nrl. GFP-tagged developing rods show Ca2+ responses and rectifier outward currents that are smaller than those observed in fully developed photoreceptors, suggesting their immature developmental state. These immature rods also exhibit hyperpolarization-activated current (Ih) induced by the activation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. When transplanted into the subretinal space of wild type or retinal degeneration mice, GFP-tagged developing rods can integrate into the photoreceptor outer nuclear layer in wild-type mouse retina, and exhibit Ca2+ responses and membrane current comparable to native rod photoreceptors. A proportion of grafted rods develop rhodopsin-positive outer segment-like structures within two weeks after transplantation into the retina of Crx-knockout mice, and produce rectifier outward current and Ih upon membrane depolarization and hyperpolarization. GFP-positive rods derived from induced pluripotent stem (iPS) cells also display similar membrane current Ih as native developing rod photoreceptors, express rod-specific phototransduction genes, and HCN-1 channels. We conclude that Nrl-promoter driven GFP-tagged donor photoreceptors exhibit physiological characteristics of rods and that iPS cell-derived rods in vitro may provide a renewable source for cell replacement therapy. PMID:23495178

Genetic and phenotypic differentiation of an Andean intermediate altitude population

PubMed Central

Eichstaedt, Christina A; Antão, Tiago; Cardona, Alexia; Pagani, Luca; Kivisild, Toomas; Mormina, Maru

2015-01-01

Highland populations living permanently under hypobaric hypoxia have been subject of extensive research because of the relevance of their physiological adaptations for the understanding of human health and disease. In this context, what is considered high altitude is a matter of interpretation and while the adaptive processes at high altitude (above 3000 m) are well documented, the effects of moderate altitude (below 3000 m) on the phenotype are less well established. In this study, we compare physiological and anthropometric characteristics as well as genetic variations in two Andean populations: the Calchaquíes (2300 m) and neighboring Collas (3500 m). We compare their phenotype and genotype to the sea-level Wichí population. We measured physiological (heart rate, oxygen saturation, respiration rate, and lung function) as well as anthropometric traits (height, sitting height, weight, forearm, and tibia length). We conducted genome-wide genotyping on a subset of the sample (n = 74) and performed various scans for positive selection. At the phenotypic level (n = 179), increased lung capacity stood out in both Andean groups, whereas a growth reduction in distal limbs was only observed at high altitude. At the genome level, Calchaquíes revealed strong signals around PRKG1, suggesting that the nitric oxide pathway may be a target of selection. PRKG1 was highlighted by one of four selection tests among the top five genes using the population branch statistic. Selection tests results of Collas were reported previously. Overall, our study shows that some phenotypic and genetic differentiation occurs at intermediate altitude in response to moderate lifelong selection pressures. PMID:25948820

Economic 3D-printing approach for transplantation of human stem cell-derived β-like cells

PubMed Central

Song, Jiwon; Millman, Jeffrey R.

2016-01-01

Transplantation of human pluripotent stem cells (hPSC) differentiated into insulin-producing β cells is a regenerative medicine approach being investigated for diabetes cell replacement therapy. This report presents a multifaceted transplantation strategy that combines differentiation into stem cell-derived β (SC-β) cells with 3D printing. By modulating the parameters of a low-cost 3D printer, we created a macroporous device composed of polylactic acid (PLA) that houses SC-β cell clusters within a degradable fibrin gel. Using finite element modeling of cellular oxygen diffusion-consumption and an in vitro culture system that allows for culture of devices at physiological oxygen levels, we identified cluster sizes that avoid severe hypoxia within 3D-printed devices and developed a microwell-based technique for resizing clusters within this range. Upon transplantation into mice, SC-β cell-embedded 3D-printed devices function for 12 weeks, are retrievable, and maintain structural integrity. Here, we demonstrate a novel 3D-printing approach that advances the use of differentiated hPSC for regenerative medicine applications and serves as a platform for future transplantation strategies. PMID:27906687

Probing Mechanoregulation of Neuronal Differentiation by Plasma Lithography Patterned Elastomeric Substrates

NASA Astrophysics Data System (ADS)

Nam, Ki-Hwan; Jamilpour, Nima; Mfoumou, Etienne; Wang, Fei-Yue; Zhang, Donna D.; Wong, Pak Kin

2014-11-01

Cells sense and interpret mechanical cues, including cell-cell and cell-substrate interactions, in the microenvironment to collectively regulate various physiological functions. Understanding the influences of these mechanical factors on cell behavior is critical for fundamental cell biology and for the development of novel strategies in regenerative medicine. Here, we demonstrate plasma lithography patterning on elastomeric substrates for elucidating the influences of mechanical cues on neuronal differentiation and neuritogenesis. The neuroblastoma cells form neuronal spheres on plasma-treated regions, which geometrically confine the cells over two weeks. The elastic modulus of the elastomer is controlled simultaneously by the crosslinker concentration. The cell-substrate mechanical interactions are also investigated by controlling the size of neuronal spheres with different cell seeding densities. These physical cues are shown to modulate with the formation of focal adhesions, neurite outgrowth, and the morphology of neuroblastoma. By systematic adjustment of these cues, along with computational biomechanical analysis, we demonstrate the interrelated mechanoregulatory effects of substrate elasticity and cell size. Taken together, our results reveal that the neuronal differentiation and neuritogenesis of neuroblastoma cells are collectively regulated via the cell-substrate mechanical interactions.

Economic 3D-printing approach for transplantation of human stem cell-derived β-like cells.

PubMed

Song, Jiwon; Millman, Jeffrey R

2016-12-01

Transplantation of human pluripotent stem cells (hPSC) differentiated into insulin-producing β cells is a regenerative medicine approach being investigated for diabetes cell replacement therapy. This report presents a multifaceted transplantation strategy that combines differentiation into stem cell-derived β (SC-β) cells with 3D printing. By modulating the parameters of a low-cost 3D printer, we created a macroporous device composed of polylactic acid (PLA) that houses SC-β cell clusters within a degradable fibrin gel. Using finite element modeling of cellular oxygen diffusion-consumption and an in vitro culture system that allows for culture of devices at physiological oxygen levels, we identified cluster sizes that avoid severe hypoxia within 3D-printed devices and developed a microwell-based technique for resizing clusters within this range. Upon transplantation into mice, SC-β cell-embedded 3D-printed devices function for 12 weeks, are retrievable, and maintain structural integrity. Here, we demonstrate a novel 3D-printing approach that advances the use of differentiated hPSC for regenerative medicine applications and serves as a platform for future transplantation strategies.

Differential expression of syndecan isoforms during mouse incisor amelogenesis.

PubMed

Muto, Taro; Miyoshi, Keiko; Munesue, Seiichi; Nakada, Hiroshi; Okayama, Minoru; Matsuo, Takashi; Noma, Takafumi

2007-08-01

Syndecans are transmembranous heparan sulfate proteoglycans (HSPGs) with covalently attached glycosaminoglycan side-chains located on the cell surface. The mammalian syndecan family is composed of four types of syndecans (syndecan-1 to -4). Syndecans interact with the intracellular cytoskeleton through the cytoplasmic domains of their core proteins and membrane proteins, extracellular enzymes, growth factors, and matrix components, through their heparan-sulfate chains, to regulate developmental processes.Here, as a first step to assess the possible roles of syndecan proteins in amelogenesis, we examined the expression patterns of all syndecan isoforms in continuously growing mouse incisors, in which we can overview major differentiation stages of amelogenesis at a glance. Understanding the expression domain of each syndecan isoform during specific developmental stages seems useful for investigating their physiological roles in amelogenesis. Immunohistochemical analysis of syndecan core proteins in the lower incisors from postnatal day 1 mice revealed spatially and temporally specific expression patterns, with syndecan-1 expressed in undifferentiated epithelial and mesenchymal cells, and syndecan-2, -3, and -4 in more differentiated cells. These findings suggest that each syndecan isoform functions distinctly during the amelogenesis of the incisors of mice.

Efficient genome editing of differentiated renal epithelial cells.

PubMed

Hofherr, Alexis; Busch, Tilman; Huber, Nora; Nold, Andreas; Bohn, Albert; Viau, Amandine; Bienaimé, Frank; Kuehn, E Wolfgang; Arnold, Sebastian J; Köttgen, Michael

2017-02-01

Recent advances in genome editing technologies have enabled the rapid and precise manipulation of genomes, including the targeted introduction, alteration, and removal of genomic sequences. However, respective methods have been described mainly in non-differentiated or haploid cell types. Genome editing of well-differentiated renal epithelial cells has been hampered by a range of technological issues, including optimal design, efficient expression of multiple genome editing constructs, attainable mutation rates, and best screening strategies. Here, we present an easily implementable workflow for the rapid generation of targeted heterozygous and homozygous genomic sequence alterations in renal cells using transcription activator-like effector nucleases (TALENs) and the clustered regularly interspaced short palindromic repeat (CRISPR) system. We demonstrate the versatility of established protocols by generating novel cellular models for studying autosomal dominant polycystic kidney disease (ADPKD). Furthermore, we show that cell culture-validated genetic modifications can be readily applied to mouse embryonic stem cells (mESCs) for the generation of corresponding mouse models. The described procedure for efficient genome editing can be applied to any cell type to study physiological and pathophysiological functions in the context of precisely engineered genotypes.

Differential TAM receptor–ligand–phospholipid interactions delimit differential TAM bioactivities

PubMed Central

Lew, Erin D; Oh, Jennifer; Burrola, Patrick G; Lax, Irit; Zagórska, Anna; Través, Paqui G; Schlessinger, Joseph; Lemke, Greg

2014-01-01

The TAM receptor tyrosine kinases Tyro3, Axl, and Mer regulate key features of cellular physiology, yet the differential activities of the TAM ligands Gas6 and Protein S are poorly understood. We have used biochemical and genetic analyses to delineate the rules for TAM receptor–ligand engagement and find that the TAMs segregate into two groups based on ligand specificity, regulation by phosphatidylserine, and function. Tyro3 and Mer are activated by both ligands but only Gas6 activates Axl. Optimal TAM signaling requires coincident TAM ligand engagement of both its receptor and the phospholipid phosphatidylserine (PtdSer): Gas6 lacking its PtdSer-binding ‘Gla domain’ is significantly weakened as a Tyro3/Mer agonist and is inert as an Axl agonist, even though it binds to Axl with wild-type affinity. In two settings of TAM-dependent homeostatic phagocytosis, Mer plays a predominant role while Axl is dispensable, and activation of Mer by Protein S is sufficient to drive phagocytosis. DOI: http://dx.doi.org/10.7554/eLife.03385.001 PMID:25265470

Lung bioengineering: physical stimuli and stem/progenitor cell biology interplay towards biofabricating a functional organ.

PubMed

Nonaka, Paula N; Uriarte, Juan J; Campillo, Noelia; Oliveira, Vinicius R; Navajas, Daniel; Farré, Ramon

2016-11-28

A current approach to obtain bioengineered lungs as a future alternative for transplantation is based on seeding stem cells on decellularized lung scaffolds. A fundamental question to be solved in this approach is how to drive stem cell differentiation onto the different lung cell phenotypes. Whereas the use of soluble factors as agents to modulate the fate of stem cells was established from an early stage of the research with this type of cells, it took longer to recognize that the physical microenvironment locally sensed by stem cells (e.g. substrate stiffness, 3D architecture, cyclic stretch, shear stress, air-liquid interface, oxygenation gradient) also contributes to their differentiation. The potential role played by physical stimuli would be particularly relevant in lung bioengineering since cells within the organ are physiologically subjected to two main stimuli required to facilitate efficient gas exchange: air ventilation and blood perfusion across the organ. The present review focuses on describing how the cell mechanical microenvironment can modulate stem cell differentiation and how these stimuli could be incorporated into lung bioreactors for optimizing organ bioengineering.

A comparative study of slow and fast suryanamaskar on physiological function

PubMed Central

Bhavanani, Ananda Balayogi; Udupa, Kaviraja; Madanmohan; Ravindra, PN

2011-01-01

Background: Numerous scientific studies have reported beneficial physiological changes after short- and long-term yoga training. Suryanamaskar (SN) is an integral part of modern yoga training and may be performed either in a slow or rapid manner. As there are few studies on SN, we conducted this study to determine the differential effect of 6 months training in the fast and slow versions. Materials and Methods: 42 school children in the age group of 12–16 years were randomly divided into two groups of 21 each. Group I and Group II received 6 months training in performance of slow suryanamaskar (SSN) and fast suryanamaskar (FSN), respectively. Results: Training in SSN produced a significant decrease in diastolic pressure. In contrast, training in FSN produced a significant increase in systolic pressure. Although there was a highly significant increase in isometric hand grip (IHG) strength and hand grip endurance (HGE) in both the groups, the increase in HGE in FSN group was significantly more than in SSN group. Pulmonary function tests showed improvements in both the groups though intergroup comparison showed no significance difference. Maximum inspiratory pressure (MIP) and maximum expiratory pressure increased significantly in both the groups with increase of MIP in FSN group being more significant than in SSN. Conclusion: The present study reports that SN has positive physiological benefits as evidenced by improvement of pulmonary function, respiratory pressures, hand grip strength and endurance, and resting cardiovascular parameters. It also demonstrates the differences between SN training when performed in a slow and fast manner, concluding that the effects of FSN are similar to physical aerobic exercises, whereas the effects of SSN are similar to those of yoga training. PMID:22022125

Global Mapping of Cell Type–Specific Open Chromatin by FAIRE-seq Reveals the Regulatory Role of the NFI Family in Adipocyte Differentiation

PubMed Central

Yu, Jing; Hirose-Yotsuya, Lisa; Take, Kazumi; Sun, Wei; Iwabu, Masato; Okada-Iwabu, Miki; Fujita, Takanori; Aoyama, Tomohisa; Tsutsumi, Shuichi; Ueki, Kohjiro; Kodama, Tatsuhiko; Sakai, Juro; Aburatani, Hiroyuki; Kadowaki, Takashi

2011-01-01

Identification of regulatory elements within the genome is crucial for understanding the mechanisms that govern cell type–specific gene expression. We generated genome-wide maps of open chromatin sites in 3T3-L1 adipocytes (on day 0 and day 8 of differentiation) and NIH-3T3 fibroblasts using formaldehyde-assisted isolation of regulatory elements coupled with high-throughput sequencing (FAIRE-seq). FAIRE peaks at the promoter were associated with active transcription and histone modifications of H3K4me3 and H3K27ac. Non-promoter FAIRE peaks were characterized by H3K4me1+/me3-, the signature of enhancers, and were largely located in distal regions. The non-promoter FAIRE peaks showed dynamic change during differentiation, while the promoter FAIRE peaks were relatively constant. Functionally, the adipocyte- and preadipocyte-specific non-promoter FAIRE peaks were, respectively, associated with genes up-regulated and down-regulated by differentiation. Genes highly up-regulated during differentiation were associated with multiple clustered adipocyte-specific FAIRE peaks. Among the adipocyte-specific FAIRE peaks, 45.3% and 11.7% overlapped binding sites for, respectively, PPARγ and C/EBPα, the master regulators of adipocyte differentiation. Computational motif analyses of the adipocyte-specific FAIRE peaks revealed enrichment of a binding motif for nuclear family I (NFI) transcription factors. Indeed, ChIP assay showed that NFI occupy the adipocyte-specific FAIRE peaks and/or the PPARγ binding sites near PPARγ, C/EBPα, and aP2 genes. Overexpression of NFIA in 3T3-L1 cells resulted in robust induction of these genes and lipid droplet formation without differentiation stimulus. Overexpression of dominant-negative NFIA or siRNA–mediated knockdown of NFIA or NFIB significantly suppressed both induction of genes and lipid accumulation during differentiation, suggesting a physiological function of these factors in the adipogenic program. Together, our study demonstrates the utility of FAIRE-seq in providing a global view of cell type–specific regulatory elements in the genome and in identifying transcriptional regulators of adipocyte differentiation. PMID:22028663

Multiple molecular effect pathways of an environmental oestrogen in fish.

PubMed

Filby, Amy L; Thorpe, Karen L; Tyler, Charles R

2006-08-01

Complex interrelationships in the signalling of oestrogenic effects mean that environmental oestrogens present in the aquatic environment have the potential to disrupt physiological function in fish in a more complex manner than portrayed in the present literature. Taking a broader approach to investigate the possible effect pathways and the likely consequences of environmental oestrogen exposure in fish, the effects of 17beta-oestradiol (E(2)) were studied on the expression of a suite of genes which interact to mediate growth, development and thyroid and interrenal function (growth hormone GH (gh), GH receptor (ghr ), insulin-like growth factor (IGF-I) (igf1), IGF-I receptor (igf1r ), thyroid hormone receptors-alpha (thra) and -beta (thrb) and glucocorticoid receptor (gr )) together with the expression analyses of sex-steroid receptors and ten other genes centrally involved in sexual development and reproduction in fathead minnow (fhm; Pimephales promelas). Exposure of adult fhm to 35 ng E(2)/l for 14 days induced classic oestrogen biomarker responses (hepatic oestrogen receptor 1 and plasma vitellogenin), and impacted on the reproductive axis, feminising "male" steroidogenic enzyme expression profiles and suppressing genes involved in testis differentiation. However, E(2) also triggered a cascade of responses for gh, ghr, igf1, igf1r, thra, thrb and gr in the pituitary, brain, liver, gonad and gill, with potential consequences for the functioning of many physiological processes, not just reproduction. Molecular responses to E(2) were complex, with most genes showing differential responses between tissues and sexes. For example, igf1 expression increased in brain but decreased in gill on exposure to E(2), and responded in an opposite way in males compared with females in liver, gonad and pituitary. These findings demonstrate the importance of developing a deeper understanding of the endocrine interactions for unravelling the mechanisms of environmental oestrogen action and predicting the likely health consequences.

TRP channels in the skin

PubMed Central

Tóth, Balázs I; Oláh, Attila; Szöllősi, Attila Gábor; Bíró, Tamás

2014-01-01

Emerging evidence suggests that transient receptor potential (TRP) ion channels not only act as ‘polymodal cellular sensors’ on sensory neurons but are also functionally expressed by a multitude of non-neuronal cell types. This is especially true in the skin, one of the largest organs of the body, where they appear to be critically involved in regulating various cutaneous functions both under physiological and pathophysiological conditions. In this review, we focus on introducing the roles of several cutaneous TRP channels in the regulation of the skin barrier, skin cell proliferation and differentiation, and immune functions. Moreover, we also describe the putative involvement of several TRP channels in the development of certain skin diseases and identify future TRP channel-targeted therapeutic opportunities. Linked Articles This article is part of a themed section on the pharmacology of TRP channels. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-10 PMID:24372189

FoxO1 transcriptional activities in VEGF expression and beyond: a key regulator in functional angiogenesis?

PubMed

Ren, Bin

2018-04-24

FoxO1 has emerged as an important regulator of angiogenesis. Recent work published in this Journal shows that FoxO1 regulates VEGF expression in keratinocytes and is required for angiogenesis in wound healing. Since FoxO1 also regulates CD36 transcription, and endothelial cell differentiation and vascular maturation, this transcription factor may be essential for the formation of functional vascular networks via coupling the regulation of CD36 in vascular endothelial cells under physiological and pathological conditions. Although many outstanding questions remain to be answered, the mechanisms by which FoxO1 regulates VEGF in keratinocytes provide insight into the development of functional angiogenesis and further our understanding of vascular biology. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Homo-trimerization is essential for the transcription factor function of Myrf for oligodendrocyte differentiation.

PubMed

Kim, Dongkyeong; Choi, Jin-Ok; Fan, Chuandong; Shearer, Randall S; Sharif, Mohamed; Busch, Patrick; Park, Yungki

2017-05-19

Myrf is a key transcription factor for oligodendrocyte differentiation and central nervous system myelination. We and others have previously shown that Myrf is generated as a membrane protein in the endoplasmic reticulum (ER), and that it undergoes auto-processing to release its N-terminal fragment from the ER, which enters the nucleus to work as a transcription factor. These previous studies allow a glimpse into the unusual complexity behind the biogenesis and function of the transcription factor domain of Myrf. Here, we report that Myrf N-terminal fragments assemble into stable homo-trimers before ER release. Consequently, Myrf N-terminal fragments are released from the ER only as homo-trimers. Our re-analysis of a previous genetic screening result in Caenorhabditis elegans shows that homo-trimerization is essential for the biological functions of Myrf N-terminal fragment, and that the region adjacent to the DNA-binding domain is pivotal to its homo-trimerization. Further, our computational analysis uncovered a novel homo-trimeric DNA motif that mediates the homo-trimeric DNA binding of Myrf N-terminal fragments. Importantly, we found that homo-trimerization defines the DNA binding specificity of Myrf N-terminal fragments. In sum, our study elucidates the molecular mechanism governing the biogenesis and function of Myrf N-terminal fragments and its physiological significance. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Transplantation of CD51+ Stem Leydig Cells: A New Strategy for the Treatment of Testosterone Deficiency.

PubMed

Zang, Zhi Jun; Wang, Jiancheng; Chen, Zhihong; Zhang, Yan; Gao, Yong; Su, Zhijian; Tuo, Ying; Liao, Yan; Zhang, Min; Yuan, Qunfang; Deng, Chunhua; Jiang, Mei Hua; Xiang, Andy Peng

2017-05-01

Stem Leydig cell (SLC) transplantation could provide a new strategy for treating the testosterone deficiency. Our previous study demonstrated that CD51 (also called integrin αv) might be a putative cell surface marker for SLCs, but the physiological function and efficacy of CD51 + SLCs treatment remain unclear. Here, we explore the potential therapeutic benefits of CD51 + SLCs transplantation and whether these transplanted cells can be regulated by the hypothalamic-pituitary-gonadal (HPG) axis. CD51 + cells were isolated from the testes of 12-weeks-old C57BL/6 mice, and we showed that such cells expressed SLC markers and that they were capable of self-renewal, extensive proliferation, and differentiation into multiple mesenchymal cell lineages and LCs in vitro. As a specific cytotoxin that eliminates Leydig cells (LCs) in adult rats, ethane dimethanesulfonate (EDS) was used to ablate LCs before the SLC transplantation. After being transplanted into the testes of EDS-treated rats, the CD51 + cells differentiated into mature LCs, and the recipient rats showed a partial recovery of testosterone production and spermatogenesis. Notably, a testosterone analysis revealed a circadian rhythm of testosterone secretion in cell-transplanted rats, and these testosterone secretions could be suppressed by decapeptyl (a luteinizing hormone-releasing hormone agonist), suggesting that the transplanted cells might be regulated by the HPG axis. This study is the first to demonstrate that CD51 + SLCs can restore the neuroendocrine regulation of testicular function by physiologically recovering the expected episodic changes in diurnal testosterone serum levels and that SLC transplantation may provide a new tool for the studies of testosterone deficiency treatment. Stem Cells 2017;35:1222-1232. © 2017 AlphaMed Press.

The AQUA-FONTIS study: protocol of a multidisciplinary, cross-sectional and prospective longitudinal study for developing standardized diagnostics and classification of non-thyroidal illness syndrome

PubMed Central

Dietrich, Johannes W; Stachon, Axel; Antic, Biljana; Klein, Harald H; Hering, Steffen

2008-01-01

Background Non-thyroidal illness syndrome (NTIS) is a characteristic functional constellation of thyrotropic feedback control that frequently occurs in critically ill patients. Although this condition is associated with significantly increased morbidity and mortality, there is still controversy on whether NTIS is caused by artefacts, is a form of beneficial adaptation, or is a disorder requiring treatment. Trials investigating substitution therapy of NTIS revealed contradictory results. The comparison of heterogeneous patient cohorts may be the cause for those inconsistencies. Objectives Primary objective of this study is the identification and differentiation of different functional states of thyrotropic feedback control in order to define relevant evaluation criteria for the prognosis of affected patients. Furthermore, we intend to assess the significance of an innovative physiological index approach (SPINA) in differential diagnosis between NTIS and latent (so-called "sub-clinical") thyrotoxicosis. Secondary objective is observation of variables that quantify distinct components of NTIS in the context of independent predictors of evolution, survival or pathophysiological condition and influencing or disturbing factors like medication. Design The approach to a quantitative follow-up of non-thyroidal illness syndrome (AQUA FONTIS study) is designed as both a cross-sectional and prospective longitudinal observation trial in critically ill patients. Patients are observed in at least two evaluation points with consecutive assessments of thyroid status, physiological and clinical data in additional weekly observations up to discharge. A second part of the study investigates the neuropsychological impact of NTIS and medium-term outcomes. The study design incorporates a two-module structure that covers a reduced protocol in form of an observation trial before patients give informed consent. Additional investigations are performed if and after patients agree in participation. Trial Registration ClinicalTrials.gov NCT00591032 PMID:18851740

Differential and brain region-specific regulation of Rap-1 and Epac in depressed suicide victims.

PubMed

Dwivedi, Yogesh; Mondal, Amal C; Rizavi, Hooriyah S; Faludi, Gabor; Palkovits, Miklos; Sarosi, Andrea; Conley, Robert R; Pandey, Ghanshyam N

2006-06-01

Depression is a major public health problem. Despite many years of research, the molecular mechanisms associated with depression remain unclear. Rap-1, activated in response to many extracellular stimuli, is one of the major substrates of protein kinase A, which participates in myriad physiologic functions in the brain, including cell survival and synaptic plasticity. Rap-1 is also activated directly by cyclic adenosine monophosphate through Epac, and thus participates in mediating physiologic functions independent of protein kinase A. To examine whether the pathogenesis of depression is associated with altered activation and expression of Rap-1, as well as expression of Epac, in depressed suicide victims. Postmortem study. Tissues were obtained from the Lenhossek Human Brain Program, Semmelweis University, Budapest, Hungary, and the Brain Collection Program of the Maryland Psychiatric Research Center, Baltimore. Postmortem brains of 28 depressed suicide victims and 28 nonpsychiatric control subjects. Examination of brain tissues. Rap-1 activation as well as messenger RNA and protein levels of Rap-1 and Epac in prefrontal cortex, hippocampus, and cerebellum. Rap-1 activation was significantly reduced (P<.001) in prefrontal cortex and hippocampus in the suicide group. This was associated with significant reductions in Rap-1 messenger RNA and protein levels (P<.001). In contrast, protein level of only Epac-2 (P<.001) but not Epac-1 (P = .89) was significantly increased in prefrontal cortex and hippocampus of these subjects. These changes were present whether the 2 cohorts were analyzed together or separately. None of the measures showed any significant change in cerebellum in the suicide group. Given the importance of Rap-1 in neuroprotection and synaptic plasticity, our findings of differential regulation of Rap-1 and Epac between brain regions suggest the relevance of these molecules in the pathophysiology of depression.

Transcriptome Pathway Analysis of Pathological and Physiological Aldosterone-Producing Human Tissues.

PubMed

Zhou, Junhua; Lam, Brian; Neogi, Sudeshna G; Yeo, Giles S H; Azizan, Elena A B; Brown, Morris J

2016-12-01

Primary aldosteronism is present in ≈10% of hypertensives. We previously performed a microarray assay on aldosterone-producing adenomas and their paired zona glomerulosa and fasciculata. Confirmation of top genes validated the study design and functional experiments of zona glomerulosa selective genes established the role of the encoded proteins in aldosterone regulation. In this study, we further analyzed our microarray data using AmiGO 2 for gene ontology enrichment and Ingenuity Pathway Analysis to identify potential biological processes and canonical pathways involved in pathological and physiological aldosterone regulation. Genes differentially regulated in aldosterone-producing adenoma and zona glomerulosa were associated with steroid metabolic processes gene ontology terms. Terms related to the Wnt signaling pathway were enriched in zona glomerulosa only. Ingenuity Pathway Analysis showed "NRF2-mediated oxidative stress response pathway" and "LPS (lipopolysaccharide)/IL-1 (interleukin-1)-mediated inhibition of RXR (retinoid X receptor) function" were affected in both aldosterone-producing adenoma and zona glomerulosa with associated genes having up to 21- and 8-fold differences, respectively. Comparing KCNJ5-mutant aldosterone-producing adenoma, zona glomerulosa, and zona fasciculata samples with wild-type samples, 138, 56, and 59 genes were differentially expressed, respectively (fold-change >2; P<0.05). ACSS3, encoding the enzyme that synthesizes acetyl-CoA, was the top gene upregulated in KCNJ5-mutant aldosterone-producing adenoma compared with wild-type. NEFM, a gene highly upregulated in zona glomerulosa, was upregulated in KCNJ5 wild-type aldosterone-producing adenomas. NR4A2, the transcription factor for aldosterone synthase, was highly expressed in zona fasciculata adjacent to a KCNJ5-mutant aldosterone-producing adenoma. Further interrogation of these genes and pathways could potentially provide further insights into the pathology of primary aldosteronism. © 2016 The Authors.

Recovery responses of testosterone, growth hormone, and IGF-1 after resistance exercise.

PubMed

Kraemer, William J; Ratamess, Nicholas A; Nindl, Bradley C

2017-03-01

The complexity and redundancy of the endocrine pathways during recovery related to anabolic function in the body belie an oversimplistic approach to its study. The purpose of this review is to examine the role of resistance exercise (RE) on the recovery responses of three major anabolic hormones, testosterone, growth hormone(s), and insulin-like growth factor 1. Each hormone has a complexity related to differential pathways of action as well as interactions with binding proteins and receptor interactions. Testosterone is the primary anabolic hormone, and its concentration changes during the recovery period depending on the upregulation or downregulation of the androgen receptor. Multiple tissues beyond skeletal muscle are targeted under hormonal control and play critical roles in metabolism and physiological function. Growth hormone (GH) demonstrates differential increases in recovery with RE based on the type of GH being assayed and workout being used. IGF-1 shows variable increases in recovery with RE and is intimately linked to a host of binding proteins that are essential to its integrative actions and mediating targeting effects. The RE stress is related to recruitment of muscle tissue with the glandular release of hormones as signals to target tissues to support homeostatic mechanisms for metabolism and tissue repair during the recovery process. Anabolic hormones play a crucial role in the body's response to metabolism, repair, and adaptive capabilities especially in response to anabolic-type RE. Changes of these hormones following RE during recovery in the circulatory biocompartment of blood are reflective of the many mechanisms of action that are in play in the repair and recovery process. Copyright © 2017 the American Physiological Society.

Immunohistochemical detection of active transforming growth factor-beta in situ using engineered tissue

NASA Technical Reports Server (NTRS)

Barcellos-Hoff, M. H.; Ehrhart, E. J.; Kalia, M.; Jirtle, R.; Flanders, K.; Tsang, M. L.; Chatterjee, A. (Principal Investigator)

1995-01-01

The biological activity of transforming growth factor-beta 1 (TGF-beta) is governed by dissociation from its latent complex. Immunohistochemical discrimination of active and latent TGF-beta could provide insight into TGF-beta activation in physiological and pathological processes. However, evaluation of immunoreactivity specificity in situ has been hindered by the lack of tissue in which TGF-beta status is known. To provide in situ analysis of antibodies to differentiate between these functional forms, we used xenografts of human tumor cells modified by transfection to overexpress latent TGF-beta or constitutively active TGF-beta. This comparison revealed that, whereas most antibodies did not differentiate between TGF-beta activation status, the immunoreactivity of some antibodies was activation dependent. Two widely used peptide antibodies to the amino-terminus of TGF-beta, LC(1-30) and CC(1-30) showed marked preferential immunoreactivity with active TGF-beta versus latent TGF-beta in cryosections. However, in formalin-fixed, paraffin-embedded tissue, discrimination of active TGF-beta by CC(1-30) was lost and immunoreactivity was distinctly extracellular, as previously reported for this antibody. Similar processing-dependent extracellular localization was found with a neutralizing antibody raised to recombinant TGF-beta. Antigen retrieval recovered cell-associated immunoreactivity of both antibodies. Two antibodies to peptides 78-109 showed mild to moderate preferential immunoreactivity with active TGF-beta only in paraffin sections. LC(1-30) was the only antibody tested that discriminated active from latent TGF-beta in both frozen and paraffin-embedded tissue. Thus, in situ discrimination of active versus latent TGF-beta depends on both the antibody and tissue preparation. We propose that tissues engineered to express a specific form of a given protein provide a physiological setting in which to evaluate antibody reactivity with specific functional forms of a protein.

The lifelong maintenance of mesencephalic dopaminergic neurons by Nurr1 and engrailed

PubMed Central

2014-01-01

Specific vulnerability and degeneration of the dopaminergic neurons in the substantia nigra pars compacta of the midbrain is the pathological hallmark of Parkinson’s disease. A number of transcription factors regulate the birth and development of this set of neurons and some remain constitutively expressed throughout life. These maintenance transcription factors are closely associated with essential neurophysiological functions and are required ultimately for the long-term survival of the midbrain dopaminergic neurons. The current review describes the role of two such factors, Nurr1 and engrailed, in differentiation, maturation, and in normal physiological functions including acquisition of neurotransmitter identity. The review will also elucidate the relationship of these factors with life, vulnerability, degeneration and death of mesencephalic dopaminergic neurons in the context of Parkinson’s disease. PMID:24685177

DNA damage induced by Strontium-90 exposure at low concentrations in mesenchymal stromal cells: the functional consequences

PubMed Central

Musilli, S.; Nicolas, N.; El Ali, Z.; Orellana-Moreno, P.; Grand, C.; Tack, K.; Kerdine-Römer, S.; Bertho, J. M.

2017-01-01

90Sr is one of the radionuclides released after nuclear accidents that can significantly impact human health in the long term. 90Sr accumulates mostly in the bones of exposed populations. Previous research has shown that exposure induces changes in bone physiology both in humans and in mice. We hypothesize that, due to its close location with bone marrow stromal cells (BMSCs), 90Sr could induce functional damage to stromal cells that may explain these biological effects due to chronic exposure to 90Sr. The aim of this work was to verify this hypothesis through the use of an in vitro model of MS5 stromal cell lines exposed to 1 and 10 kBq.mL−1 of 90Sr. Results indicated that a 30-minute exposure to 90Sr induced double strand breaks in DNA, followed by DNA repair, senescence and differentiation. After 7 days of exposure, MS5 cells showed a decreased ability to proliferate, changes in cytokine expression, and changes in their ability to support hematopoietic progenitor proliferation and differentiation. These results demonstrate that chronic exposure to a low concentration of 90Sr can induce functional changes in BMSCs that in turn may explain the health effects observed in following chronic 90Sr exposure. PMID:28134299

DNA damage induced by Strontium-90 exposure at low concentrations in mesenchymal stromal cells: the functional consequences.

PubMed

Musilli, S; Nicolas, N; El Ali, Z; Orellana-Moreno, P; Grand, C; Tack, K; Kerdine-Römer, S; Bertho, J M

2017-01-30

90 Sr is one of the radionuclides released after nuclear accidents that can significantly impact human health in the long term. 90 Sr accumulates mostly in the bones of exposed populations. Previous research has shown that exposure induces changes in bone physiology both in humans and in mice. We hypothesize that, due to its close location with bone marrow stromal cells (BMSCs), 90 Sr could induce functional damage to stromal cells that may explain these biological effects due to chronic exposure to 90 Sr. The aim of this work was to verify this hypothesis through the use of an in vitro model of MS5 stromal cell lines exposed to 1 and 10 kBq.mL -1 of 90 Sr. Results indicated that a 30-minute exposure to 90 Sr induced double strand breaks in DNA, followed by DNA repair, senescence and differentiation. After 7 days of exposure, MS5 cells showed a decreased ability to proliferate, changes in cytokine expression, and changes in their ability to support hematopoietic progenitor proliferation and differentiation. These results demonstrate that chronic exposure to a low concentration of 90 Sr can induce functional changes in BMSCs that in turn may explain the health effects observed in following chronic 90 Sr exposure.

Changes in global gene expression during in vitro decidualization of rat endometrial stromal cells

PubMed Central

Vallejo, Griselda; Maschi, Darío; Citrinovitz, Ana Cecilia Mestre; Aiba, Kazuhiro; Maronna, Ricardo; Yohai, Victor; Ko, Minoru S. H.; Beato, Miguel; Saragüeta, Patricia

2009-01-01

During the preimplantation phase of pregnancy the endometrial stroma differentiates into decidua, a process that implies numerous morphological changes and is an example of physiological transdifferentiation. Here we show that UIII rat endometrial stromal cells cultured in the presence of calf serum acquired morphological features of decidual cells and expressed decidual markers. To identify genes involved in decidualization we compared gene expression patterns of control and decidualized UIII cells using cDNA microarray. We found 322 annotated genes exhibiting significant differences in expression (>3 fold, FDR > 0.005), of which 312 have not been previously related to decidualization. Analysis of overrepresented functions revealed that protein synthesis, gene expression and chromatin architecture and remodeling are the most relevant modified functions during decidualization. Relevant genes are also found in the functional terms differentiation, cell proliferation, signal transduction, and matrix/structural proteins. Several of these new genes involved in decidualization (Csdc2, Trim27, Eef1a1, Bmp1, Wt1, Aes, Gna12, and Men1) are shown to be also regulated in uterine decidua during normal pregnancy. Thus, the UIII cell culture model will allow future mechanistic studies to define the transcriptional network regulating reprogramming of stromal cells into decidual cells. PMID:19780023

Three-dimensional culture conditions differentially affect astrocyte modulation of brain endothelial barrier function in response to transforming growth factor β1.

PubMed

Hawkins, Brian T; Grego, Sonia; Sellgren, Katelyn L

2015-05-22

Blood-brain barrier (BBB) function is regulated by dynamic interactions among cell types within the neurovascular unit, including astrocytes and endothelial cells. Co-culture models of the BBB typically involve astrocytes seeded on two-dimensional (2D) surfaces, which recent studies indicate cause astrocytes to express a phenotype similar to that of reactive astrocytes in situ. We hypothesized that the culture conditions of astrocytes would differentially affect their ability to modulate BBB function in vitro. Brain endothelial cells were grown alone or in co-culture with astrocytes. Astrocytes were grown either as conventional (2D) monolayers, or in a collagen-based gel which allows them to grow in a three-dimensional (3D) construct. Astrocytes were viable in 3D conditions, and displayed a marked reduction in their expression of glial fibrillary acidic protein (GFAP), suggesting reduced activation. Stimulation of astrocytes with transforming growth factor (TGF)β1 decreased transendothelial electrical resistance (TEER) and reduced expression of claudin-5 in co-cultures, whereas treatment of endothelial cells in the absence of astrocytes was without effect. The effect of TGFβ1 on TEER was significantly more pronounced in endothelial cells cultured with 3D astrocytes compared to 2D astrocytes. These results demonstrate that astrocyte culture conditions differentially affect their ability to modulate brain endothelial barrier function, and suggest a direct relationship between reactive gliosis and BBB permeability. Moreover, these studies demonstrate the potential importance of physiologically relevant culture conditions to in vitro modeling of disease processes that affect the neurovascular unit. Copyright © 2015 Elsevier B.V. All rights reserved.

β Subunits Functionally Differentiate Human Kv4.3 Potassium Channel Splice Variants

PubMed Central

Abbott, Geoffrey W.

2017-01-01

The human ventricular cardiomyocyte transient outward K+ current (Ito) mediates the initial phase of myocyte repolarization and its disruption is implicated in Brugada Syndrome and heart failure (HF). Human cardiac Ito is generated primarily by two Kv4.3 splice variants (Kv4.3L and Kv4.3S, diverging only by a C-terminal, S6-proximal, 19-residue stretch unique to Kv4.3L), which are differentially remodeled in HF, but considered functionally alike at baseline. Kv4.3 is regulated in human heart by β subunits including KChIP2b and KCNEs, but their effects were previously assumed to be Kv4.3 isoform-independent. Here, this assumption was tested experimentally using two-electrode voltage-clamp analysis of human subunits co-expressed in Xenopus laevis oocytes. Unexpectedly, Kv4.3L-KChIP2b channels exhibited up to 8-fold lower current augmentation, 40% slower inactivation, and 5 mV-shifted steady-state inactivation compared to Kv4.3S-KChIP2b. A synthetic peptide mimicking the 19-residue stretch diminished these differences, reinforcing the importance of this segment in mediating Kv4.3 regulation by KChIP2b. KCNE subunits induced further functional divergence, including a 7-fold increase in Kv4.3S-KCNE4-KChIP2b current compared to Kv4.3L-KCNE4-KChIP2b. The discovery of β-subunit-dependent functional divergence in human Kv4.3 splice variants suggests a C-terminal signaling hub is crucial to governing β-subunit effects upon Kv4.3, and demonstrates the potential significance of differential Kv4.3 gene-splicing and β subunit expression in myocyte physiology and pathobiology. PMID:28228734

β Subunits Functionally Differentiate Human Kv4.3 Potassium Channel Splice Variants.

PubMed

Abbott, Geoffrey W

2017-01-01

The human ventricular cardiomyocyte transient outward K + current ( I to ) mediates the initial phase of myocyte repolarization and its disruption is implicated in Brugada Syndrome and heart failure (HF). Human cardiac I to is generated primarily by two Kv4.3 splice variants (Kv4.3L and Kv4.3S, diverging only by a C-terminal, S6-proximal, 19-residue stretch unique to Kv4.3L), which are differentially remodeled in HF, but considered functionally alike at baseline. Kv4.3 is regulated in human heart by β subunits including KChIP2b and KCNEs, but their effects were previously assumed to be Kv4.3 isoform-independent. Here, this assumption was tested experimentally using two-electrode voltage-clamp analysis of human subunits co-expressed in Xenopus laevis oocytes. Unexpectedly, Kv4.3L-KChIP2b channels exhibited up to 8-fold lower current augmentation, 40% slower inactivation, and 5 mV-shifted steady-state inactivation compared to Kv4.3S-KChIP2b. A synthetic peptide mimicking the 19-residue stretch diminished these differences, reinforcing the importance of this segment in mediating Kv4.3 regulation by KChIP2b. KCNE subunits induced further functional divergence, including a 7-fold increase in Kv4.3S-KCNE4-KChIP2b current compared to Kv4.3L-KCNE4-KChIP2b. The discovery of β-subunit-dependent functional divergence in human Kv4.3 splice variants suggests a C-terminal signaling hub is crucial to governing β-subunit effects upon Kv4.3, and demonstrates the potential significance of differential Kv4.3 gene-splicing and β subunit expression in myocyte physiology and pathobiology.

Growth and physiological plasticity among differentially adapted genotypes of a widespread C4 grass under altered precipitation

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods Variation in precipitation expected with climate change may impact plant fitness and alter ecosystem dynamics by modifying species phenology, productivity, and physiology. Species responses to varied precipitation will depend in part on plastic responses of genotypes ad...

Regulation of gene expression by the BLM helicase correlates with the presence of G-quadruplex DNA motifs

PubMed Central

Nguyen, Giang Huong; Tang, Weiliang; Robles, Ana I.; Beyer, Richard P.; Gray, Lucas T.; Welsh, Judith A.; Schetter, Aaron J.; Kumamoto, Kensuke; Wang, Xin Wei; Hickson, Ian D.; Maizels, Nancy; Monnat, Raymond J.; Harris, Curtis C.

2014-01-01

Bloom syndrome is a rare autosomal recessive disorder characterized by genetic instability and cancer predisposition, and caused by mutations in the gene encoding the Bloom syndrome, RecQ helicase-like (BLM) protein. To determine whether altered gene expression might be responsible for pathological features of Bloom syndrome, we analyzed mRNA and microRNA (miRNA) expression in fibroblasts from individuals with Bloom syndrome and in BLM-depleted control fibroblasts. We identified mRNA and miRNA expression differences in Bloom syndrome patient and BLM-depleted cells. Differentially expressed mRNAs are connected with cell proliferation, survival, and molecular mechanisms of cancer, and differentially expressed miRNAs target genes involved in cancer and in immune function. These and additional altered functions or pathways may contribute to the proportional dwarfism, elevated cancer risk, immune dysfunction, and other features observed in Bloom syndrome individuals. BLM binds to G-quadruplex (G4) DNA, and G4 motifs were enriched at transcription start sites (TSS) and especially within first introns (false discovery rate ≤ 0.001) of differentially expressed mRNAs in Bloom syndrome compared with normal cells, suggesting that G-quadruplex structures formed at these motifs are physiologic targets for BLM. These results identify a network of mRNAs and miRNAs that may drive the pathogenesis of Bloom syndrome. PMID:24958861

Regulation of gene expression by the BLM helicase correlates with the presence of G-quadruplex DNA motifs.

PubMed

Nguyen, Giang Huong; Tang, Weiliang; Robles, Ana I; Beyer, Richard P; Gray, Lucas T; Welsh, Judith A; Schetter, Aaron J; Kumamoto, Kensuke; Wang, Xin Wei; Hickson, Ian D; Maizels, Nancy; Monnat, Raymond J; Harris, Curtis C

2014-07-08

Bloom syndrome is a rare autosomal recessive disorder characterized by genetic instability and cancer predisposition, and caused by mutations in the gene encoding the Bloom syndrome, RecQ helicase-like (BLM) protein. To determine whether altered gene expression might be responsible for pathological features of Bloom syndrome, we analyzed mRNA and microRNA (miRNA) expression in fibroblasts from individuals with Bloom syndrome and in BLM-depleted control fibroblasts. We identified mRNA and miRNA expression differences in Bloom syndrome patient and BLM-depleted cells. Differentially expressed mRNAs are connected with cell proliferation, survival, and molecular mechanisms of cancer, and differentially expressed miRNAs target genes involved in cancer and in immune function. These and additional altered functions or pathways may contribute to the proportional dwarfism, elevated cancer risk, immune dysfunction, and other features observed in Bloom syndrome individuals. BLM binds to G-quadruplex (G4) DNA, and G4 motifs were enriched at transcription start sites (TSS) and especially within first introns (false discovery rate ≤ 0.001) of differentially expressed mRNAs in Bloom syndrome compared with normal cells, suggesting that G-quadruplex structures formed at these motifs are physiologic targets for BLM. These results identify a network of mRNAs and miRNAs that may drive the pathogenesis of Bloom syndrome.

Temporal impact of substrate mechanics on differentiation of human embryonic stem cells to cardiomyocytes.

PubMed

Hazeltine, Laurie B; Badur, Mehmet G; Lian, Xiaojun; Das, Amritava; Han, Wenqing; Palecek, Sean P

2014-02-01

A significant clinical need exists to differentiate human pluripotent stem cells (hPSCs) into cardiomyocytes, enabling tissue modeling for in vitro discovery of new drugs or cell-based therapies for heart repair in vivo. Chemical and mechanical microenvironmental factors are known to impact the efficiency of stem cell differentiation, but cardiac differentiation protocols in hPSCs are typically performed on rigid tissue culture polystyrene (TCPS) surfaces, which do not present a physiological mechanical setting. To investigate the temporal effects of mechanics on cardiac differentiation, we cultured human embryonic stem cells (hESCs) and their derivatives on polyacrylamide hydrogel substrates with a physiologically relevant range of stiffnesses. In directed differentiation and embryoid body culture systems, differentiation of hESCs to cardiac troponin T-expressing (cTnT+) cardiomyocytes peaked on hydrogels of intermediate stiffness. Brachyury expression also peaked on intermediate stiffness hydrogels at day 1 of directed differentiation, suggesting that stiffness impacted the initial differentiation trajectory of hESCs to mesendoderm. To investigate the impact of substrate mechanics during cardiac specification of mesodermal progenitors, we initiated directed cardiomyocyte differentiation on TCPS and transferred cells to hydrogels at the Nkx2.5/Isl1+ cardiac progenitor cell stage. No differences in cardiomyocyte purity with stiffness were observed on day 15. These experiments indicate that differentiation of hESCs is sensitive to substrate mechanics at early stages of mesodermal induction, and proper application of substrate mechanics can increase the propensity of hESCs to differentiate to cardiomyocytes. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Designing 3-Dimensional In Vitro Oviduct Culture Systems to Study Mammalian Fertilization and Embryo Production.

PubMed

Ferraz, Marcia A M M; Henning, Heiko H W; Stout, Tom A E; Vos, Peter L A M; Gadella, Bart M

2017-07-01

The oviduct was long considered a largely passive conduit for gametes and embryos. However, an increasing number of studies into oviduct physiology have demonstrated that it specifically and significantly influences gamete interaction, fertilization and early embryo development. While oviduct epithelial cell (OEC) function has been examined during maintenance in conventional tissue culture dishes, cells seeded into these two-dimensional (2-D) conditions suffer a rapid loss of differentiated OEC characteristics, such as ciliation and secretory activity. Recently, three-dimensional (3-D) cell culture systems have been developed that make use of cell inserts to create basolateral and apical medium compartments with a confluent epithelial cell layer at the interface. Using such 3-D culture systems, OECs can be triggered to redevelop typical differentiated cell properties and levels of tissue organization can be developed that are not possible in a 2-D culture. 3-D culture systems can be further refined using new micro-engineering techniques (including microfluidics and 3-D printing) which can be used to produce 'organs-on-chips', i.e. live 3-D cultures that bio-mimic the oviduct. In this review, concepts for designing bio-mimic 3-D oviduct cultures are presented. The increased possibilities and concomitant challenges when trying to more closely investigate oviduct physiology, gamete activation, fertilization and embryo production are discussed.

Role of Vitamin A/Retinoic Acid in Regulation of Embryonic and Adult Hematopoiesis.

PubMed

Cañete, Ana; Cano, Elena; Muñoz-Chápuli, Ramón; Carmona, Rita

2017-02-20

Vitamin A is an essential micronutrient throughout life. Its physiologically active metabolite retinoic acid (RA), acting through nuclear retinoic acid receptors (RARs), is a potent regulator of patterning during embryonic development, as well as being necessary for adult tissue homeostasis. Vitamin A deficiency during pregnancy increases risk of maternal night blindness and anemia and may be a cause of congenital malformations. Childhood Vitamin A deficiency can cause xerophthalmia, lower resistance to infection and increased risk of mortality. RA signaling appears to be essential for expression of genes involved in developmental hematopoiesis, regulating the endothelial/blood cells balance in the yolk sac, promoting the hemogenic program in the aorta-gonad-mesonephros area and stimulating eryrthropoiesis in fetal liver by activating the expression of erythropoietin. In adults, RA signaling regulates differentiation of granulocytes and enhances erythropoiesis. Vitamin A may facilitate iron absorption and metabolism to prevent anemia and plays a key role in mucosal immune responses, modulating the function of regulatory T cells. Furthermore, defective RA/RARα signaling is involved in the pathogenesis of acute promyelocytic leukemia due to a failure in differentiation of promyelocytes. This review focuses on the different roles played by vitamin A/RA signaling in physiological and pathological mouse hematopoiesis duddurring both, embryonic and adult life, and the consequences of vitamin A deficiency for the blood system.

Members of the neuropeptide transcriptional network in Helicoverpa armigera and their expression in response to light stress.

PubMed

Wang, Lijun; Liu, Xinhui; Liu, Zhengxing; Wang, Xiaoping; Lei, Chaoliang; Zhu, Fen

2018-05-19

Neuropeptides and peptide hormones play central roles in the regulation of various types of insect physiology and behavior. Artificial light at night, a form of environmental stress, has recently been regarded as a source of light stress on nocturnal insects. Because related genomic information is not available, molecular biological studies on the response of neuropeptides in nocturnal insects to light stress are limited. Based on the de novo sequencing of the Helicoverpa armigera head transcriptome, we obtained 124,960 unigenes. Of these, the number of unigenes annotated as neuropeptides and peptide hormones, neurotransmitter precursor processing enzymes, and neurotransmitter receptors were 34, 17, and 58, respectively. Under light stress, there were sex-specific differences in gene expression measured by qRT-PCR. The IMFamide, leucokinin and sNPF genes were differentially expressed at the mRNA level in males but not in females in response to light stress. The results provide new insights on the diversity of the neuropeptide transcriptional network of H. armigera. In addition, some neuropeptides exhibited sex-specific differential expression in response to light stress. Taken collectively, these results not only expand the catalog of known insect neuropeptides but also provide a framework for future functional studies on the physiological roles they play in the light stress response behavior of nocturnal moths. Copyright © 2017. Published by Elsevier B.V.

In Vivo Studies in Rhodospirillum rubrum Indicate That Ribulose-1,5-bisphosphate Carboxylase/Oxygenase (Rubisco) Catalyzes Two Obligatorily Required and Physiologically Significant Reactions for Distinct Carbon and Sulfur Metabolic Pathways*♦

PubMed Central

Dey, Swati; North, Justin A.; Sriram, Jaya; Evans, Bradley S.; Tabita, F. Robert

2015-01-01

All organisms possess fundamental metabolic pathways to ensure that needed carbon and sulfur compounds are provided to the cell in the proper chemical form and oxidation state. For most organisms capable of using CO2 as sole source of carbon, ribulose-1,5-bisphosphate (RuBP) carboxylase/oxygenase (Rubisco) catalyzes primary carbon dioxide assimilation. In addition, sulfur salvage pathways are necessary to ensure that key sulfur-containing compounds are both available and, where necessary, detoxified in the cell. Using knock-out mutations and metabolomics in the bacterium Rhodospirillum rubrum, we show here that Rubisco concurrently catalyzes key and essential reactions for seemingly unrelated but physiologically essential central carbon and sulfur salvage metabolic pathways of the cell. In this study, complementation and mutagenesis studies indicated that representatives of all known extant functional Rubisco forms found in nature are capable of simultaneously catalyzing reactions required for both CO2-dependent growth as well as growth using 5-methylthioadenosine as sole sulfur source under anaerobic photosynthetic conditions. Moreover, specific inactivation of the CO2 fixation reaction did not affect the ability of Rubisco to support anaerobic 5-methylthioadenosine metabolism, suggesting that the active site of Rubisco has evolved to ensure that this enzyme maintains both key functions. Thus, despite the coevolution of both functions, the active site of this protein may be differentially modified to affect only one of its key functions. PMID:26511314

Microglia across the lifespan: from origin to function in brain development, plasticity and cognition

PubMed Central

Savage, Julie C.; Hui, Chin Wai; Bisht, Kanchan

2016-01-01

Abstract Microglia are the only immune cells that permanently reside in the central nervous system (CNS) alongside neurons and other types of glial cells. The past decade has witnessed a revolution in our understanding of their roles during normal physiological conditions. Cutting‐edge techniques revealed that these resident immune cells are critical for proper brain development, actively maintain health in the mature brain, and rapidly adapt their function to physiological or pathophysiological needs. In this review, we highlight recent studies on microglial origin (from the embryonic yolk sac) and the factors regulating their differentiation and homeostasis upon brain invasion. Elegant experiments tracking microglia in the CNS allowed studies of their unique roles compared with other types of resident macrophages. Here we review the emerging roles of microglia in brain development, plasticity and cognition, and discuss the implications of the depletion or dysfunction of microglia for our understanding of disease pathogenesis. Immune activation, inflammation and various other conditions resulting in undesirable microglial activity at different stages of life could severely impair learning, memory and other essential cognitive functions. The diversity of microglial phenotypes across the lifespan, between compartments of the CNS, and sexes, as well as their crosstalk with the body and external environment, is also emphasised. Understanding what defines particular microglial phenotypes is of major importance for future development of innovative therapies controlling their effector functions, with consequences for cognition across chronic stress, ageing, neuropsychiatric and neurological diseases. PMID:27104646

Conopeptide Vt3.1 preferentially inhibits BK potassium channels containing β4 subunits via electrostatic interactions.

PubMed

Li, Min; Chang, Shan; Yang, Longjin; Shi, Jingyi; McFarland, Kelli; Yang, Xiao; Moller, Alyssa; Wang, Chunguang; Zou, Xiaoqin; Chi, Chengwu; Cui, Jianmin

2014-02-21

BK channel β subunits (β1-β4) modulate the function of channels formed by slo1 subunits to produce tissue-specific phenotypes. The molecular mechanism of how the homologous β subunits differentially alter BK channel functions and the role of different BK channel functions in various physiologic processes remain unclear. By studying channels expressed in Xenopus laevis oocytes, we show a novel disulfide-cross-linked dimer conopeptide, Vt3.1 that preferentially inhibits BK channels containing the β4 subunit, which is most abundantly expressed in brain and important for neuronal functions. Vt3.1 inhibits the currents by a maximum of 71%, shifts the G-V relation by 45 mV approximately half-saturation concentrations, and alters both open and closed time of single channel activities, indicating that the toxin alters voltage dependence of the channel. Vt3.1 contains basic residues and inhibits voltage-dependent activation by electrostatic interactions with acidic residues in the extracellular loops of the slo1 and β4 subunits. These results suggest a large interaction surface between the slo1 subunit of BK channels and the β4 subunit, providing structural insight into the molecular interactions between slo1 and β4 subunits. The results also suggest that Vt3.1 is an excellent tool for studying β subunit modulation of BK channels and for understanding the physiological roles of BK channels in neurophysiology.

How we may think: Imaging and writing technologies across the history of the neurosciences.

PubMed

Borck, Cornelius

2016-06-01

In the neurosciences, two alternative regimes of visualization can be differentiated: anatomical preparations for morphological images and physiological studies for functional representations. Adapting a distinction proposed by Peter Galison, this duality of visualization regimes is analyzed here as the contrast between an imaging and a writing approach: the imaging approach, focusing on mimetic representations, preserving material and spatial relations, and the writing approach as used in physiological studies, retaining functional relations. After a dominance of morphological images gathering iconic representations of brains and architectural brain theories, the advent of electroencephalography advanced writing approaches with their indexical signs. Addressing the brain allegedly at its mode of operation, electroencephalography was conceived as recording the brain's intrinsic language, extending the writing approach to include symbolic signs. The availability of functional neuroimaging signaled an opportunity to overcome the duality of imaging and writing, but revived initially a phrenological conflation of form and function, suppressing the writing approach in relation to imaging. More sophisticated visualization modes, however, converted this reductionism to the ontological productivity of social neuroscience and recuperated the theorizing from the writing approach. In light of the ongoing instrumental mediations between brains, data and theories, the question of how we may think, once proposed by Vannevar Bush as a prospect of enhanced human-machine interaction, has become the state of affairs in the entanglements of instruments and organic worlds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Different patterns of sexual dysfunctions associated with psychiatric disorders and psychopharmacological treatment. Results of an investigation by semistructured interview of schizophrenic and neurotic patients and methadone-substituted opiate addicts.

PubMed

Teusch, L; Scherbaum, N; Böhme, H; Bender, S; Eschmann-Mehl, G; Gastpar, M

1995-05-01

Little is known about sexual dysfunctions associated with psychiatric disorders and psychopharmacological treatment. In the present study schizophrenic patients (n = 45, mostly under neuroleptic treatment), neurotic patients (n = 50, mostly treated without medication), methadone-substituted opiate addicts (n = 37), and normal controls (n = 41) were included. They were interviewed with the aid of a sex-differentiated semistructured questionnaire on sexual function. All the methadone-substituted opiate addicts and nearly all the schizophrenic patients suffered from dysfunctions in at least one criterion. The three clinical groups differed significantly from the controls in sexual interest, emotional arousal, physiological arousal (erectile function/vaginal lubrication), performance (ejaculatory function/vaginism, dyspareunia), and orgasm satisfaction. Characteristic patterns of dysfunction were found in the male patients. The schizophrenic patients had significantly more dysfunctions of interest, physiological arousal, performance, and orgasm than the controls. Emotional arousal, erectile and ejaculatory functions, and orgasm satisfaction were impaired more frequently in the male schizophrenics than in the neurotic patients. Reduced sexual interest, emotional arousal, and orgasm satisfaction were reported more frequently by the methadone-substituted opiate addicts than by the neurotic men. Emotional arousal was even more frequently reduced than in the schizophrenic men. There was no correlation between sexual dysfunction and particular neuroleptics or neuroleptic or methadone dosage. The results are compared with the literature and suggestions made for further investigations.

Intrinsically Disordered Proteins and the Origins of Multicellular Organisms

NASA Astrophysics Data System (ADS)

Dunker, A. Keith

In simple multicellular organisms all of the cells are in direct contact with the surrounding milieu, whereas in complex multicellular organisms some cells are completely surrounded by other cells. Current phylogenetic trees indicate that complex multicellular organisms evolved independently from unicellular ancestors about 10 times, and only among the eukaryotes, including once for animals, twice each for green, red, and brown algae, and thrice for fungi. Given these multiple independent evolutionary lineages, we asked two questions: 1. Which molecular functions underpinned the evolution of multicellular organisms?; and, 2. Which of these molecular functions depend on intrinsically disordered proteins (IDPs)? Compared to unicellularity, multicellularity requires the advent of molecules for cellular adhesion, for cell-cell communication and for developmental programs. In addition, the developmental programs need to be regulated over space and time. Finally, each multicellular organism has cell-specific biochemistry and physiology. Thus, the evolution of complex multicellular organisms from unicellular ancestors required five new classes of functions. To answer the second question we used Key-words in Swiss Protein ranked for associations with predictions of protein structure or disorder. With a Z-score of 18.8 compared to random-function proteins, à differentiation was the biological process most strongly associated with IDPs. As expected from this result, large numbers of individual proteins associated with differentiation exhibit substantial regions of predicted disorder. For the animals for which there is the most readily available data all five of the underpinning molecular functions for multicellularity were found to depend critically on IDP-based mechanisms and other evidence supports these ideas. While the data are more sparse, IDPs seem to similarly underlie the five new classes of functions for plants and fungi as well, suggesting that IDPs were indeed crucial for the evolution of complex multicellular organisms. These new findings necessitate a rethinking of the gene regulatory network models currently used to explain cellular differentiation and the evolution of complex multicellular organisms.

Employee subjective well-being and physiological functioning: An integrative model.

PubMed

Kuykendall, Lauren; Tay, Louis

2015-01-01

Research shows that worker subjective well-being influences physiological functioning-an early signal of poor health outcomes. While several theoretical perspectives provide insights on this relationship, the literature lacks an integrative framework explaining the relationship. We develop a conceptual model explaining the link between subjective well-being and physiological functioning in the context of work. Integrating positive psychology and occupational stress perspectives, our model explains the relationship between subjective well-being and physiological functioning as a result of the direct influence of subjective well-being on physiological functioning and of their common relationships with work stress and personal resources, both of which are influenced by job conditions.

Metabolomic profiles indicate distinct physiological pathways affected by two loci with major divergent effect on Bos taurus growth and lipid deposition.

PubMed

Weikard, Rosemarie; Altmaier, Elisabeth; Suhre, Karsten; Weinberger, Klaus M; Hammon, Harald M; Albrecht, Elke; Setoguchi, Kouji; Takasuga, Akiko; Kühn, Christa

2010-10-01

Identifying trait-associated genetic variation offers new prospects to reveal novel physiological pathways modulating complex traits. Taking advantage of a unique animal model, we identified the I442M mutation in the non-SMC condensin I complex, subunit G (NCAPG) gene and the Q204X mutation in the growth differentiation factor 8 (GDF8) gene as substantial modulators of pre- and/or postnatal growth in cattle. In a combined metabolomic and genotype association approach, which is the first respective study in livestock, we surveyed the specific physiological background of the effects of both loci on body-mass gain and lipid deposition. Our data provided confirming evidence from two historically and geographically distant cattle populations that the onset of puberty is the key interval of divergent growth. The locus-specific metabolic patterns obtained from monitoring 201 plasma metabolites at puberty mirror the particular NCAPG I442M and GDF8 Q204X effects and represent biosignatures of divergent physiological pathways potentially modulating effects on proportional and disproportional growth, respectively. While the NCAPG I442M mutation affected the arginine metabolism, the 204X allele in the GDF8 gene predominantly raised the carnitine level and had concordant effects on glycerophosphatidylcholines and sphingomyelins. Our study provides a conclusive link between the well-described growth-regulating functions of arginine metabolism and the previously unknown specific physiological role of the NCAPG protein in mammalian metabolism. Owing to the confirmed effect of the NCAPG/LCORL locus on human height in genome-wide association studies, the results obtained for bovine NCAPG might add valuable, comparative information on the physiological background of genetically determined divergent mammalian growth.

Two-dimensional strain profiles in patients with physiological and pathological hypertrophy and preserved left ventricular systolic function: a comparative analyses.

PubMed

Afonso, Luis; Kondur, Ashok; Simegn, Mengistu; Niraj, Ashutosh; Hari, Pawan; Kaur, Ramanjit; Ramappa, Preeti; Pradhan, Jyotiranjan; Bhandare, Deepti; Williams, Kim A; Zalawadiya, Sandip; Pinheiro, Aurelio; Abraham, Theodore P

2012-01-01

This study was designed to examine the utility of two-dimensional strain (2DS) or speckle tracking imaging to typify functional adaptations of the left ventricle in variant forms of left ventricular hypertrophy (LVH). Cross-sectional study. Urban tertiary care academic medical centres. A total of 129 subjects, 56 with hypertrophic cardiomyopathy (HCM), 34 with hypertensive left ventricular hypertrophy (H-LVH), 27 professional athletes with LVH (AT-LVH) and 12 healthy controls in sinus rhythm with preserved left ventricular systolic function. Conventional echocardiographic and tissue Doppler examinations were performed in all study subjects. Bi-dimensional acquisitions were analysed to map longitudinal systolic strain (automated function imaging, AFI, GE Healthcare, Waukesha, Wisconsin, USA) from apical views. Subjects with HCM had significantly lower regional and average global peak longitudinal systolic strain (GLS-avg) compared with controls and other forms of LVH. Strain dispersion index, a measure of regional contractile heterogeneity, was higher in HCM compared with the rest of the groups. On receiver operator characteristics analysis, GLS-avg had excellent discriminatory ability to distinguish HCM from H-LVH area under curve (AUC) (0.893, p<0.001) or AT-LVH AUC (0.920, p<0.001). Tissue Doppler and LV morphological parameters were better suited to differentiate the athlete heart from HCM. 2DS (AFI) allows rapid characterisation of regional and global systolic function and may have the potential to differentiate HCM from variant forms of LVH.

Odontoblast-Like Cells Differentiated from Dental Pulp Stem Cells Retain Their Phenotype after Subcultivation

PubMed Central

Baldión, Paula A.; Velandia-Romero, Myriam L.

2018-01-01

Odontoblasts, the main cell type in teeth pulp tissue, are not cultivable and they are responsible for the first line of response after dental restauration. Studies on dental materials cytotoxicity and odontoblast cells physiology require large quantity of homogenous cells retaining most of the phenotype characteristics. Odontoblast-like cells (OLC) were differentiated from human dental pulp stem cells using differentiation medium (containing TGF-β1), and OLC expanded after trypsinization (EXP-21) were evaluated and compared. Despite a slower cell growth curve, EXP-21 cells express similarly the odontoblast markers dentinal sialophosphoprotein and dentin matrix protein-1 concomitantly with RUNX2 transcripts and low alkaline phosphatase activity as expected. Both OLC and EXP-21 cells showed similar mineral deposition activity evidenced by alizarin red and von Kossa staining. These results pointed out minor changes in phenotype of subcultured EXP-21 regarding the primarily differentiated OLC, making the subcultivation of these cells a useful strategy to obtain odontoblasts for biocompatibility or cell physiology studies in dentistry. PMID:29670655

Differentiation of K562 cells under ELF-EMF applied at different time courses.

PubMed

Ayşe, Inhan-Garip; Zafer, Akan; Sule, Oncul; Işil, Işal-Turgut; Kalkan, Tunaya

2010-08-01

The time-course of ELF-EMF application to biological systems is thought to be an important parameter determining the physiological outcome. This study investigated the effect of ELF-EMF on the differentiation of K562 cells at different time courses. ELF-EMF (50 Hz, 5 mT, 1 h) was applied at two different time-courses; first at the onset of hemin induction for 1 h, and second, daily 1 h for four days. While single exposure to ELF-EMF resulted in a decrease in differentiation, ELF-EMF applied everyday for 1 h caused an increase in differentiation. The effect of co-stressors, magnesium, and heat-shock was also determined and similar results were obtained. ELF-EMF increased ROS levels in K562 cells not treated with hemin, however did not change ROS levels of hemin treated cells indicating that ROS was not the cause. Overall, these results imply that the time-course of application is an important parameter determining the physiological response of cells to ELF-EMF.

Monosodium urate monohydrate crystals inhibit osteoblast viability and function: implications for development of bone erosion in gout.

PubMed

Chhana, Ashika; Callon, Karen E; Pool, Bregina; Naot, Dorit; Watson, Maureen; Gamble, Greg D; McQueen, Fiona M; Cornish, Jillian; Dalbeth, Nicola

2011-09-01

Bone erosion is a common manifestation of chronic tophaceous gout. To investigate the effects of monosodium urate monohydrate (MSU) crystals on osteoblast viability and function. The MTT assay and flow cytometry were used to assess osteoblast cell viability in the MC3T3-E1 and ST2 osteoblast-like cell lines, and primary rat and primary human osteoblasts cultured with MSU crystals. Quantitative real-time PCR and von Kossa stained mineralised bone formation assays were used to assess the effects of MSU crystals on osteoblast differentiation using MC3T3-E1 cells. The numbers of osteoblasts and bone lining cells were quantified in bone samples from patients with gout. MSU crystals rapidly reduced viability in all cell types in a dose-dependent manner. The inhibitory effect on cell viability was independent of crystal phagocytosis and was not influenced by differing crystal length or addition of serum. Long-term culture of MC3T3-E1 cells with MSU crystals showed a reduction in mineralisation and decreased mRNA expression of genes related to osteoblast differentiation such as Runx2, Sp7 (osterix), Ibsp (bone sialoprotein), and Bglap (osteocalcin). Fewer osteoblast and lining cells were present on bone directly adjacent to gouty tophus than bone unaffected by tophus in patients with gout. MSU crystals have profound inhibitory effects on osteoblast viability and differentiation. These data suggest that bone erosion in gout occurs at the tophus-bone interface through alteration of physiological bone turnover, with both excessive osteoclast formation, and reduced osteoblast differentiation from mesenchymal stem cells.

Phenyl-γ-valerolactones, flavan-3-ol colonic metabolites, protect brown adipocytes from oxidative stress without affecting their differentiation or function.

PubMed

Mele, Laura; Carobbio, Stefania; Brindani, Nicoletta; Curti, Claudio; Rodriguez-Cuenca, Sergio; Bidault, Guillaume; Mena, Pedro; Zanotti, Ilaria; Vacca, Michele; Vidal-Puig, Antonio; Del Rio, Daniele

2017-09-01

Consumption of products rich in flavan-3-ols, such as tea and cocoa, has been associated with decreased obesity, partially dependent on their capacity to enhance energy expenditure. Despite these phenolics having been reported to increase the thermogenic program in brown and white adipose tissue, flavan-3-ols are vastly metabolised in vivo to phenyl-γ-valerolactones. Therefore, we hypothesize that phenyl-γ-valerolactones may directly stimulate the differentiation and the activation of brown adipocytes. Immortalized brown pre-adipocytes were differentiated in presence of (R)-5-(3',4'-dihydroxyphenyl)-γ-valerolactone (VL1), (R)-5-(3´-hydroxyphenyl)-γ-valerolactone-4'-O-sulphate (VL2), (R)-5-phenyl-γ-valerolactone-3´,4´-di-O-sulphate (VL3), at concentrations of 2 or 10μM, whereas fully differentiated brown adipocyte were treated acutely (6-24h). None of the treatments regulated the expression levels of the uncouple protein 1, nor of the main transcription factors involved in brown adipogenesis. Similarly, mitochondrial content was unchanged after treatments. Moreover these compounds did not display peroxisome proliferator-activated receptor γ-agonist activity, as evaluated by luciferase assay, and did not enhance norepinephrine-stimulated lipolysis in mature adipocytes. However, both VL1 and VL2 prevented oxidative stress caused by H 2 O 2 . Phenyl-γ-valerolactones and their sulphated forms do not influence brown adipocyte development or function at physiological or supraphysiological doses in vitro, but they are active protecting brown adipocytes from increased reactive oxygen species production. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Subcutaneous and gonadal adipose tissue transcriptome differences in lean and obese female dogs.

PubMed

Grant, Ryan W; Vester Boler, Brittany M; Ridge, Tonya K; Graves, Thomas K; Swanson, Kelly S

2013-12-01

Canine obesity leads to shortened life span and increased disease incidence. Adipose tissue depots are known to have unique metabolic and gene expression profiles in rodents and humans, but few comparisons of depot gene expression have been performed in the dog. Using microarray technology, our objective was to identify differentially expressed genes and enriched functional pathways between subcutaneous and gonadal adipose of lean and obese dogs to better understand the pathogenesis of obesity in the dog. Because no depot × body weight status interactions were identified in the microarray data, depot differences were the primary focus. A total of 946 and 703 transcripts were differentially expressed (FDR P < 0.05) between gonadal and subcutaneous adipose tissue in obese and lean dogs respectively. Of the adipose depot-specific differences in gene expression, 162 were present in both lean and obese dogs, with the majority (85%) expressed in the same direction. Both lean and obese dog gene lists had enrichment of the complement and coagulation cascade and systemic lupus erythematosus pathways. Obese dogs had enrichment of lysosome, extracellular matrix-receptor interaction, renin-angiotensin system and hematopoietic cell lineage pathways. Lean dogs had enrichment of glutathione metabolism and synthesis and degradation of ketone bodies. We have identified a core set of genes differentially expressed between subcutaneous and gonadal adipose tissue in dogs regardless of body weight. These genes contribute to depot-specific differences in immune function, extracellular matrix remodeling and lysosomal function and may contribute to the physiological differences noted between depots. © 2013 The Authors, Animal Genetics © 2013 Stichting International Foundation for Animal Genetics.

Estrogen receptor β (ERβ1) transactivation is differentially modulated by the transcriptional coregulator Tip60 in a cis-acting element-dependent manner.

PubMed

Lee, Ming-Tsung; Leung, Yuet-Kin; Chung, Irving; Tarapore, Pheruza; Ho, Shuk-Mei

2013-08-30

Estrogen receptor (ER) β1 and ERα have overlapping and distinct functions despite their common use of estradiol as the physiological ligand. These attributes are explained in part by their differential utilization of coregulators and ligands. Although Tip60 has been shown to interact with both receptors, its regulatory role in ERβ1 transactivation has not been defined. In this study, we found that Tip60 enhances transactivation of ERβ1 at the AP-1 site but suppresses its transcriptional activity at the estrogen-response element (ERE) site in an estradiol-independent manner. However, different estrogenic compounds can modify the Tip60 action. The corepressor activity of Tip60 at the ERE site is abolished by diarylpropionitrile, genistein, equol, and bisphenol A, whereas its coactivation at the AP-1 site is augmented by fulvestrant (ICI 182,780). GRIP1 is an important tethering mediator for ERs at the AP-1 site. We found that coexpression of GRIP1 synergizes the action of Tip60. Although Tip60 is a known acetyltransferase, it is unable to acetylate ERβ1, and its coregulatory functions are independent of its acetylation activity. In addition, we showed the co-occupancy of ERβ1 and Tip60 at ERE and AP-1 sites of ERβ1 target genes. Tip60 differentially regulates the endogenous expression of the target genes by modulating the binding of ERβ1 to the cis-regulatory regions. Thus, we have identified Tip60 as the first dual-function coregulator of ERβ1.

Estrogen Receptor β (ERβ1) Transactivation Is Differentially Modulated by the Transcriptional Coregulator Tip60 in a cis-Acting Element-dependent Manner*

PubMed Central

Lee, Ming-Tsung; Leung, Yuet-Kin; Chung, Irving; Tarapore, Pheruza; Ho, Shuk-Mei

2013-01-01

Estrogen receptor (ER) β1 and ERα have overlapping and distinct functions despite their common use of estradiol as the physiological ligand. These attributes are explained in part by their differential utilization of coregulators and ligands. Although Tip60 has been shown to interact with both receptors, its regulatory role in ERβ1 transactivation has not been defined. In this study, we found that Tip60 enhances transactivation of ERβ1 at the AP-1 site but suppresses its transcriptional activity at the estrogen-response element (ERE) site in an estradiol-independent manner. However, different estrogenic compounds can modify the Tip60 action. The corepressor activity of Tip60 at the ERE site is abolished by diarylpropionitrile, genistein, equol, and bisphenol A, whereas its coactivation at the AP-1 site is augmented by fulvestrant (ICI 182,780). GRIP1 is an important tethering mediator for ERs at the AP-1 site. We found that coexpression of GRIP1 synergizes the action of Tip60. Although Tip60 is a known acetyltransferase, it is unable to acetylate ERβ1, and its coregulatory functions are independent of its acetylation activity. In addition, we showed the co-occupancy of ERβ1 and Tip60 at ERE and AP-1 sites of ERβ1 target genes. Tip60 differentially regulates the endogenous expression of the target genes by modulating the binding of ERβ1 to the cis-regulatory regions. Thus, we have identified Tip60 as the first dual-function coregulator of ERβ1. PMID:23857583

Meta-analysis of chicken--salmonella infection experiments.

PubMed

Te Pas, Marinus F W; Hulsegge, Ina; Schokker, Dirkjan; Smits, Mari A; Fife, Mark; Zoorob, Rima; Endale, Marie-Laure; Rebel, Johanna M J

2012-04-24

Chicken meat and eggs can be a source of human zoonotic pathogens, especially Salmonella species. These food items contain a potential hazard for humans. Chickens lines differ in susceptibility for Salmonella and can harbor Salmonella pathogens without showing clinical signs of illness. Many investigations including genomic studies have examined the mechanisms how chickens react to infection. Apart from the innate immune response, many physiological mechanisms and pathways are reported to be involved in the chicken host response to Salmonella infection. The objective of this study was to perform a meta-analysis of diverse experiments to identify general and host specific mechanisms to the Salmonella challenge. Diverse chicken lines differing in susceptibility to Salmonella infection were challenged with different Salmonella serovars at several time points. Various tissues were sampled at different time points post-infection, and resulting host transcriptional differences investigated using different microarray platforms. The meta-analysis was performed with the R-package metaMA to create lists of differentially regulated genes. These gene lists showed many similarities for different chicken breeds and tissues, and also for different Salmonella serovars measured at different times post infection. Functional biological analysis of these differentially expressed gene lists revealed several common mechanisms for the chicken host response to Salmonella infection. The meta-analysis-specific genes (i.e. genes found differentially expressed only in the meta-analysis) confirmed and expanded the biological functional mechanisms. The meta-analysis combination of heterogeneous expression profiling data provided useful insights into the common metabolic pathways and functions of different chicken lines infected with different Salmonella serovars.

Meta-analysis of Chicken – Salmonella infection experiments

PubMed Central

2012-01-01

Background Chicken meat and eggs can be a source of human zoonotic pathogens, especially Salmonella species. These food items contain a potential hazard for humans. Chickens lines differ in susceptibility for Salmonella and can harbor Salmonella pathogens without showing clinical signs of illness. Many investigations including genomic studies have examined the mechanisms how chickens react to infection. Apart from the innate immune response, many physiological mechanisms and pathways are reported to be involved in the chicken host response to Salmonella infection. The objective of this study was to perform a meta-analysis of diverse experiments to identify general and host specific mechanisms to the Salmonella challenge. Results Diverse chicken lines differing in susceptibility to Salmonella infection were challenged with different Salmonella serovars at several time points. Various tissues were sampled at different time points post-infection, and resulting host transcriptional differences investigated using different microarray platforms. The meta-analysis was performed with the R-package metaMA to create lists of differentially regulated genes. These gene lists showed many similarities for different chicken breeds and tissues, and also for different Salmonella serovars measured at different times post infection. Functional biological analysis of these differentially expressed gene lists revealed several common mechanisms for the chicken host response to Salmonella infection. The meta-analysis-specific genes (i.e. genes found differentially expressed only in the meta-analysis) confirmed and expanded the biological functional mechanisms. Conclusions The meta-analysis combination of heterogeneous expression profiling data provided useful insights into the common metabolic pathways and functions of different chicken lines infected with different Salmonella serovars. PMID:22531008

Role of TRP channels in the cardiovascular system.

PubMed

Yue, Zhichao; Xie, Jia; Yu, Albert S; Stock, Jonathan; Du, Jianyang; Yue, Lixia

2015-02-01

The transient receptor potential (TRP) superfamily consists of a large number of nonselective cation channels with variable degree of Ca(2+)-permeability. The 28 mammalian TRP channel proteins can be grouped into six subfamilies: canonical, vanilloid, melastatin, ankyrin, polycystic, and mucolipin TRPs. The majority of these TRP channels are expressed in different cell types including both excitable and nonexcitable cells of the cardiovascular system. Unlike voltage-gated ion channels, TRP channels do not have a typical voltage sensor, but instead can sense a variety of other stimuli including pressure, shear stress, mechanical stretch, oxidative stress, lipid environment alterations, hypertrophic signals, and inflammation products. By integrating multiple stimuli and transducing their activity to downstream cellular signal pathways via Ca(2+) entry and/or membrane depolarization, TRP channels play an essential role in regulating fundamental cell functions such as contraction, relaxation, proliferation, differentiation, and cell death. With the use of targeted deletion and transgenic mouse models, recent studies have revealed that TRP channels are involved in numerous cellular functions and play an important role in the pathophysiology of many diseases in the cardiovascular system. Moreover, several TRP channels are involved in inherited diseases of the cardiovascular system. This review presents an overview of current knowledge concerning the physiological functions of TRP channels in the cardiovascular system and their contributions to cardiovascular diseases. Ultimately, TRP channels may become potential therapeutic targets for cardiovascular diseases. Copyright © 2015 the American Physiological Society.

Maintenance of sweat glands by stem cells located in the acral epithelium.

PubMed

Ohe, Shuichi; Tanaka, Toshihiro; Yanai, Hirotsugu; Komai, Yoshihiro; Omachi, Taichi; Kanno, Shohei; Tanaka, Kiyomichi; Ishigaki, Kazuhiko; Saiga, Kazuho; Nakamura, Naohiro; Ohsugi, Haruyuki; Tokuyama, Yoko; Atsumi, Naho; Hisha, Hiroko; Yoshida, Naoko; Kumano, Keiki; Yamazaki, Fumikazu; Okamoto, Hiroyuki; Ueno, Hiroo

2015-10-23

The skin is responsible for a variety of physiological functions and is critical for wound healing and repair. Therefore, the regenerative capacity of the skin is important. However, stem cells responsible for maintaining the acral epithelium had not previously been identified. In this study, we identified the specific stem cells in the acral epithelium that participate in the long-term maintenance of sweat glands, ducts, and interadnexal epidermis and that facilitate the regeneration of these structures following injury. Lgr6-positive cells and Bmi1-positive cells were found to function as long-term multipotent stem cells that maintained the entire eccrine unit and the interadnexal epidermis. However, while Lgr6-positive cells were rapidly cycled and constantly supplied differentiated cells, Bmi1-positive cells were slow to cycle and occasionally entered the cell cycle under physiological conditions. Upon irradiation-induced injury, Bmi1-positive cells rapidly proliferated and regenerated injured epithelial tissue. Therefore, Bmi1-positive stem cells served as reservoir stem cells. Lgr5-positive cells were rapidly cycled and maintained only sweat glands; therefore, we concluded that these cells functioned as lineage-restricted progenitors. Taken together, our data demonstrated the identification of stem cells that maintained the entire acral epithelium and supported the different roles of three cellular classes. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Different Expression Profiles Suggest Functional Differentiation Among Chemosensory Proteins in Nilaparvata lugens (Hemiptera: Delphacidae)

PubMed Central

Yang, Ke; He, Peng; Dong, Shuang-Lin

2014-01-01

Abstract Chemosensory proteins (CSPs) play various roles in insect physiology including olfaction and development. The brown planthopper, Nilaparvata lugens Stål , is one of the most notorious rice pests worldwide. The wing-from variation and annually long distance migration imply that olfaction would play a key role in N. lugens behavior. In this study, full-length cDNAs of nine CSPs were cloned by the rapid amplification of cDNA ends procedure, and their expression profiles were determined by the quantitative real-time Polymerase Chain Reaction (qPCR), with regard to developmental stage, wing-form, gender, and tissues of short-wing adult. These NlugCSP genes showed distinct expression patterns, indicating different roles they play. In particular, NlugCSP5 was long wing form biased and highly expressed in female wings among tissues; NlugCSP1 was mainly expressed in male adults and abdomen; NlugCSP7 was widely expressed in chemosensory tissues but little in the nonchemosensory abdomen. The function of NlugCSP7 in olfaction was further explored by the competitive fluorescence binding assay using the recombinant protein. However, the recombinant NlugCSP7 showed no obvious binding with all tested volatile compounds, suggesting that it may participate in physiological processes other than olfaction. Our results provide bases and some important clues for the function of NlugCSPs . PMID:25527582

X box binding protein XBP-1s transactivates the Kaposi's sarcoma-associated herpesvirus (KSHV) ORF50 promoter, linking plasma cell differentiation to KSHV reactivation from latency.

PubMed

Wilson, Sam J; Tsao, Edward H; Webb, Benjamin L J; Ye, Hongtao; Dalton-Griffin, Lucy; Tsantoulas, Christoforos; Gale, Catherine V; Du, Ming-Qing; Whitehouse, Adrian; Kellam, Paul

2007-12-01

Reactivation of lytic replication from viral latency is a defining property of all herpesviruses. Despite this, the authentic physiological cues for the latent-lytic switch are unclear. Such cues should ensure that viral lytic replication occurs under physiological conditions, predominantly in sites which facilitate transmission to permissive uninfected cells and new susceptible hosts. Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with the B-cell neoplasm primary effusion lymphoma (PEL), in which the virus remains latent. We have previously shown that PEL cells have the gene expression profile and immunophenotype of cycling preplasma cells (plasmablasts). Here, we show that the highly active spliced isoform of plasma cell transcription factor X box binding protein 1 (XBP-1s) is a lytic switch for KSHV. XBP-1s is normally absent in PEL, but the induction of endoplasmic reticulum stress leads to XBP-1s generation, plasma cell-like differentiation, and lytic reactivation of KSHV. XBP-1s binds to and activates the KSHV immediate-early gene ORF50 and synergizes with the ORF50 gene product RTA to induce a full lytic cycle. These data suggest that KSHV remains latent until B-cell terminal differentiation into plasma cells, the transcriptional environment of which provides the physiological "lytic switch" through XBP-1s. This links B-cell terminal differentiation to KSHV lytic reactivation.

Representation of the Physiological Factors Contributing to Postflight Changes in Functional Performance Using Motion Analysis Software

NASA Technical Reports Server (NTRS)

Parks, Kelsey

2010-01-01

Astronauts experience changes in multiple physiological systems due to exposure to the microgravity conditions of space flight. To understand how changes in physiological function influence functional performance, a testing procedure has been developed that evaluates both astronaut postflight functional performance and related physiological changes. Astronauts complete seven functional and physiological tests. The objective of this project is to use motion tracking and digitizing software to visually display the postflight decrement in the functional performance of the astronauts. The motion analysis software will be used to digitize astronaut data videos into stick figure videos to represent the astronauts as they perform the Functional Tasks Tests. This project will benefit NASA by allowing NASA scientists to present data of their neurological studies without revealing the identities of the astronauts.

Chemical hybridizing agent SQ-1-induced male sterility in Triticum aestivum L.: a comparative analysis of the anther proteome.

PubMed

Liu, Hongzhan; Zhang, Gaisheng; Wang, Junsheng; Li, Jingjing; Song, Yulong; Qiao, Lin; Niu, Na; Wang, Junwei; Ma, Shoucai; Li, Lili

2018-01-05

Heterosis is widely used to increase the yield of many crops. However, as wheat is a self-pollinating crop, hybrid breeding is not so successful in this organism. Even though male sterility induced by chemical hybridizing agents is an important aspect of crossbreeding, the mechanisms by which these agents induce male sterility in wheat is not well understood. We performed proteomic analyses using the wheat Triticum aestivum L.to identify those proteins involved in physiological male sterility (PHYMS) induced by the chemical hybridizing agent CHA SQ-1. A total of 103 differentially expressed proteins were found by 2D-PAGE and subsequently identified by MALDI-TOF/TOF MS/MS. In general, these proteins had obvious functional tendencies implicated in carbohydrate metabolism, oxidative stress and resistance, protein metabolism, photosynthesis, and cytoskeleton and cell structure. In combination with phenotypic, tissue section, and bioinformatics analyses, the identified differentially expressed proteins revealed a complex network behind the regulation of PHYMS and pollen development. Accordingly, we constructed a protein network of male sterility in wheat, drawing relationships between the 103 differentially expressed proteins and their annotated biological pathways. To further validate our proposed protein network, we determined relevant physiological values and performed real-time PCR assays. Our proteomics based approach has enabled us to identify certain tendencies in PHYMS anthers. Anomalies in carbohydrate metabolism and oxidative stress, together with premature tapetum degradation, may be the cause behind carbohydrate starvation and male sterility in CHA SQ-1 treated plants. Here, we provide important insight into the mechanisms underlying CHA SQ-1-induced male sterility. Our findings have practical implications for the application of hybrid breeding in wheat.

Variation in Thermal Sensitivity and Thermal Tolerances in an Invasive Species across a Climatic Gradient: Lessons from the Land Snail Cornu aspersum

PubMed Central

Gaitán-Espitia, Juan Diego; Belén Arias, María; Lardies, Marco A.; Nespolo, Roberto F.

2013-01-01

The ability of organisms to perform at different temperatures could be described by a continuous nonlinear reaction norm (i.e., thermal performance curve, TPC), in which the phenotypic trait value varies as a function of temperature. Almost any shift in the parameters of this performance curve could highlight the direct effect of temperature on organism fitness, providing a powerful framework for testing thermal adaptation hypotheses. Inter-and intraspecific differences in this performance curve are also reflected in thermal tolerances limits (e.g., critical and lethal limits), influencing the biogeographic patterns of species’ distribution. Within this context, here we investigated the intraspecific variation in thermal sensitivities and thermal tolerances in three populations of the invasive snail Cornu aspersum across a geographical gradient, characterized by different climatic conditions. Thus, we examined population differentiation in the TPCs, thermal-coma recovery times, expression of heat-shock proteins and standard metabolic rate (i.e., energetic costs of physiological differentiation). We tested two competing hypotheses regarding thermal adaptation (the “hotter is better” and the generalist-specialist trade-offs). Our results show that the differences in thermal sensitivity among populations of C. aspersum follow a latitudinal pattern, which is likely the result of a combination of thermodynamic constraints (“hotter is better”) and thermal adaptations to their local environments (generalist-specialist trade-offs). This finding is also consistent with some thermal tolerance indices such as the Heat-Shock Protein Response and the recovery time from chill-coma. However, mixed responses in the evaluated traits suggest that thermal adaptation in this species is not complete, as we were not able to detect any differences in neither energetic costs of physiological differentiation among populations, nor in the heat-coma recovery. PMID:23940617

Variation in thermal sensitivity and thermal tolerances in an invasive species across a climatic gradient: lessons from the land snail Cornu aspersum.

PubMed

Gaitán-Espitia, Juan Diego; Belén Arias, María; Lardies, Marco A; Nespolo, Roberto F

2013-01-01

The ability of organisms to perform at different temperatures could be described by a continuous nonlinear reaction norm (i.e., thermal performance curve, TPC), in which the phenotypic trait value varies as a function of temperature. Almost any shift in the parameters of this performance curve could highlight the direct effect of temperature on organism fitness, providing a powerful framework for testing thermal adaptation hypotheses. Inter-and intraspecific differences in this performance curve are also reflected in thermal tolerances limits (e.g., critical and lethal limits), influencing the biogeographic patterns of species' distribution. Within this context, here we investigated the intraspecific variation in thermal sensitivities and thermal tolerances in three populations of the invasive snail Cornu aspersum across a geographical gradient, characterized by different climatic conditions. Thus, we examined population differentiation in the TPCs, thermal-coma recovery times, expression of heat-shock proteins and standard metabolic rate (i.e., energetic costs of physiological differentiation). We tested two competing hypotheses regarding thermal adaptation (the "hotter is better" and the generalist-specialist trade-offs). Our results show that the differences in thermal sensitivity among populations of C. aspersum follow a latitudinal pattern, which is likely the result of a combination of thermodynamic constraints ("hotter is better") and thermal adaptations to their local environments (generalist-specialist trade-offs). This finding is also consistent with some thermal tolerance indices such as the Heat-Shock Protein Response and the recovery time from chill-coma. However, mixed responses in the evaluated traits suggest that thermal adaptation in this species is not complete, as we were not able to detect any differences in neither energetic costs of physiological differentiation among populations, nor in the heat-coma recovery.

Quantitative Proteomic and Microarray Analysis of the Archaeon Methanosarcina Acetivorans Grown with Acetate Versus Methanol*

PubMed Central

Li, Lingyun; Li, Qingbo; Rohlin, Lars; Kim, UnMi; Salmon, Kirsty; Rejtar, Tomas; Gunsalus, Robert P.; Karger, Barry L.; Ferry, James G.

2008-01-01

Summary Methanosarcina acetivorans strain C2A is an acetate- and methanol-utilizing methane-producing organism for which the genome, the largest yet sequenced among the Archaea, reveals extensive physiological diversity. LC linear ion trap-FTICR mass spectrometry was employed to analyze acetate- vs. methanol-grown cells metabolically labeled with 14N vs. 15N, respectively, to obtain quantitative protein abundance ratios. DNA microarray analyses of acetate- vs. methanol-grown cells was also performed to determine gene expression ratios. The combined approaches were highly complementary, extending the physiological understanding of growth and methanogenesis. Of the 1081 proteins detected, 255 were ≥ 3-fold differentially abundant. DNA microarray analysis revealed 410 genes that were ≥ 2.5-fold differentially expressed of 1972 genes with detected expression. The ratios of differentially abundant proteins were in good agreement with expression ratios of the encoding genes. Taken together, the results suggest several novel roles for electron transport components specific to acetate-grown cells, including two flavodoxins each specific for growth on acetate or methanol. Protein abundance ratios indicated that duplicate CO dehydrogenase/acetyl-CoA complexes function in the conversion of acetate to methane. Surprisingly, the protein abundance and gene expression ratios indicated a general stress response in acetate- vs. methanol-grown cells that included enzymes specific for polyphosphate accumulation and oxidative stress. The microarray analysis identified transcripts of several genes encoding regulatory proteins with identity to the PhoU, MarR, GlnK, and TetR families commonly found in the Bacteria domain. An analysis of neighboring genes suggested roles in controlling phosphate metabolism (PhoU), ammonia assimilation (GlnK), and molybdopterin cofactor biosynthesis (TetR). Finally, the proteomic and microarray results suggested roles for two-component regulatory systems specific for each growth substrate. PMID:17269732

Liraglutide attenuates the osteoblastic differentiation of MC3T3-E1 cells by modulating AMPK/mTOR signaling

PubMed Central

Hu, Xiong-Ke; Yin, Xin-Hua; Zhang, Hong-Qi; Guo, Chao-Feng; Tang, Ming-Xing

2016-01-01

Liraglutide, a synthetic analogue of glucagon-like peptide-1, is utilized in the treatment of type 2 diabetes and obesity. Liraglutide has been previously demonstrated to prevent osteoblastic differentiation of human vascular smooth muscle cells, resulting in the slowing of arterial calcification, however, its effect on bone formation remains unclear. The present study investigated the effect of liraglutide on osteoblastic differentiation using Alizarin Red S staining, and examined the molecular mechanisms underlying the regulatory effect by western blot analysis. The present study demonstrated that protein expression levels of phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK) were downregulated in MC3T3-E1 cells during osteoblastic differentiation in commercial osteogenic differentiation medium, whereas protein expression levels of transforming growth factor-β (TGF-β) and phosphorylated mammalian target of rapamycin (p-mTOR) increased. Liraglutide was subsequently demonstrated to dose-dependently attenuate the osteoblastic differentiation of MC3T3-E1 cells, to upregulate p-AMPK, and downregulate p-mTOR and TGF-β protein expression levels. Treatment with an AMPK-specific inhibitor, Compound C, eradicated the effect of liraglutide on osteoblastic differentiation, and p-mTOR and TGF-β downregulation. An mTOR activator, MHY1485, also abolished the inhibitory effect of liraglutide on osteoblastic differentiation, and resulted in p-mTOR and TGF-β downregulation, but did not attenuate the liraglutide-induced increase in p-AMPK protein expression levels. The results of the present study demonstrate that liraglutide attenuates osteoblastic differentiation of MC3T3-E1 cells via modulation of AMPK/mTOR signaling. The present study revealed a novel function of liraglutide, which contributes to the understanding of its pharmacological and physiological effects in clinical settings. PMID:27600753

Cardiovascular Reactivity During Marital Conflict in Laboratory and Naturalistic Settings: Differential Associations with Relationship and Individual Functioning Across Contexts.

PubMed

Baucom, Brian R W; Baucom, Katherine J W; Hogan, Jasara N; Crenshaw, Alexander O; Bourne, Stacia V; Crowell, Sheila E; Georgiou, Panayiotis; Goodwin, Matthew S

2018-03-25

Cardiovascular reactivity during spousal conflict is considered to be one of the main pathways for relationship distress to impact physical, mental, and relationship health. However, the magnitude of association between cardiovascular reactivity during laboratory marital conflict and relationship functioning is small and inconsistent given the scope of its importance in theoretical models of intimate relationships. This study tests the possibility that cardiovascular data collected in laboratory settings downwardly bias the magnitude of these associations when compared to measures obtained in naturalistic settings. Ambulatory cardiovascular reactivity data were collected from 20 couples during two relationship conflicts in a research laboratory, two planned relationship conflicts at couples' homes, and two spontaneous relationship conflicts during couples' daily lives. Associations between self-report measures of relationship functioning, individual functioning, and cardiovascular reactivity across settings are tested using multilevel models. Cardiovascular reactivity was significantly larger during planned and spontaneous relationship conflicts in naturalistic settings than during planned relationship conflicts in the laboratory. Similarly, associations with relationship and individual functioning variables were statistically significantly larger for cardiovascular data collected in naturalistic settings than the same data collected in the laboratory. Our findings suggest that cardiovascular reactivity during spousal conflict in naturalistic settings is statistically significantly different from that elicited in laboratory settings both in magnitude and in the pattern of associations with a wide range of inter- and intrapersonal variables. These differences in findings across laboratory and naturalistic physiological responses highlight the value of testing physiological phenomena across interaction contexts in romantic relationships. © 2018 Family Process Institute.

To what extent is altitudinal variation of functional traits driven by genetic adaptation in European oak and beech?

PubMed

Bresson, Caroline C; Vitasse, Yann; Kremer, Antoine; Delzon, Sylvain

2011-11-01

The phenotypic responses of functional traits in natural populations are driven by genetic diversity and phenotypic plasticity. These two mechanisms enable trees to cope with rapid climate change. We studied two European temperate tree species (sessile oak and European beech), focusing on (i) in situ variations of leaf functional traits (morphological and physiological) along two altitudinal gradients and (ii) the extent to which these variations were under environmental and/or genetic control using a common garden experiment. For all traits, altitudinal trends tended to be highly consistent between species and transects. For both species, leaf mass per area displayed a positive linear correlation with altitude, whereas leaf size was negatively correlated with altitude. We also observed a significant increase in leaf physiological performance with increasing altitude: populations at high altitudes had higher maximum rates of assimilation, stomatal conductance and leaf nitrogen content than those at low altitudes. In the common garden experiment, genetic differentiation between populations accounted for 0-28% of total phenotypic variation. However, only two traits (leaf mass per area and nitrogen content) exhibited a significant cline. The combination of in situ and common garden experiments used here made it possible to demonstrate, for both species, a weaker effect of genetic variation than of variations in natural conditions, suggesting a strong effect of the environment on leaf functional traits. Finally, we demonstrated that intrapopulation variability was systematically higher than interpopulation variability, whatever the functional trait considered, indicating a high potential capacity to adapt to climate change.

Evolution of the rodent eosinophil-associated RNase gene family by rapid gene sorting and positive selection

PubMed Central

Zhang, Jianzhi; Dyer, Kimberly D.; Rosenberg, Helene F.

2000-01-01

The mammalian RNase A superfamily comprises a diverse array of ribonucleolytic proteins that have a variety of biochemical activities and physiological functions. Two rapidly evolving RNases of higher primates are of particular interest as they are major secretory proteins of eosinophilic leukocytes and have been found to possess anti-pathogen activities in vitro. To understand how these RNases acquired this function during evolution and to develop animal models for the study of their functions in vivo, it is necessary to investigate these genes in many species. Here, we report the sequences of 38 functional genes and 23 pseudogenes of the eosinophil-associated RNase (EAR) family from 5 rodent species. Our phylogenetic analysis of these genes showed a clear pattern of evolution by a rapid birth-and-death process and gene sorting, a process characterized by rapid gene duplication and deactivation occurring differentially among lineages. This process ultimately generates distinct or only partially overlapping inventories of the genes, even in closely related species. Positive Darwinian selection also contributed to the diversification of these EAR genes. The striking similarity between the evolutionary patterns of the EAR genes and those of the major histocompatibility complex, immunoglobulin, and T cell receptor genes stands in strong support of the hypothesis that host-defense and generation of diversity are among the primary physiological function of the rodent EARs. The discovery of a large number of divergent EARs suggests the intriguing possibility that these proteins have been specifically tailored to fight against distinct rodent pathogens. PMID:10758160

Differential distribution of glutamate- and GABA-gated chloride channels in the housefly Musca domestica.

PubMed

Kita, Tomo; Ozoe, Fumiyo; Azuma, Masaaki; Ozoe, Yoshihisa

2013-09-01

l-Glutamic acid (glutamate) mediates fast inhibitory neurotransmission by affecting glutamate-gated chloride channels (GluCls) in invertebrates. The molecular function and pharmacological properties of GluCls have been well studied, but not much is known about their physiological role and localization in the insect body. The distribution of GluCls in the housefly (Musca domestica L.) was thus compared with the distribution of γ-aminobutyric acid (GABA)-gated chloride channels (GABACls). Quantitative PCR and ligand-binding experiments indicate that the GluCl and GABACl transcripts and proteins are predominantly expressed in the adult head. Intense GluCl immunostaining was detected in the lamina, leg motor neurons, and legs of adult houseflies. The GABACl (Rdl) immunostaining was more widely distributed, and was found in the medulla, lobula, lobula plate, mushroom body, antennal lobe, and ellipsoid body. The present findings suggest that GluCls have physiological roles in different tissues than GABACls. Copyright © 2013 Elsevier Ltd. All rights reserved.

R-Spondin1 expands Paneth cells and prevents dysbiosis induced by graft-versus-host disease

PubMed Central

Hayase, Eiko; Nakamura, Kiminori; Noizat, Clara; Ogasawara, Reiki; Ohigashi, Hiroyuki; Sugimoto, Rina; Matsuoka, Satomi; Ara, Takahide; Yokoyama, Emi; Yamakawa, Tomohiro; Ebata, Ko; Kondo, Takeshi; Aizawa, Tomoyasu; Ogura, Yoshitoshi; Hayashi, Tetsuya; Mori, Hiroshi; Tomizuka, Kazuma; Ayabe, Tokiyoshi

2017-01-01

The intestinal microbial ecosystem is actively regulated by Paneth cell–derived antimicrobial peptides such as α-defensins. Various disorders, including graft-versus-host disease (GVHD), disrupt Paneth cell functions, resulting in unfavorably altered intestinal microbiota (dysbiosis), which further accelerates the underlying diseases. Current strategies to restore the gut ecosystem are bacteriotherapy such as fecal microbiota transplantation and probiotics, and no physiological approach has been developed so far. In this study, we demonstrate a novel approach to restore gut microbial ecology by Wnt agonist R-Spondin1 (R-Spo1) or recombinant α-defensin in mice. R-Spo1 stimulates intestinal stem cells to differentiate to Paneth cells and enhances luminal secretion of α-defensins. Administration of R-Spo1 or recombinant α-defensin prevents GVHD-mediated dysbiosis, thus representing a novel and physiological approach at modifying the gut ecosystem to restore intestinal homeostasis and host–microbiota cross talk toward therapeutic benefits. PMID:29066578

Physiological state characterization by clustering heart rate, heart rate variability and movement activity information.

PubMed

Bidargaddi, Niranjan; Sarela, Antti; Korhonen, Ilkka

2008-01-01

The objective is to identify whether it is possible to discriminate between normal and abnormal physiological state based on heart rate (HR), heart rate variability (HRV) and movement activity information in subjects with cardiovascular complications. HR, HRV and movement information were obtained from cardiac patients over a period of 6 weeks using an ambulatory activity and single lead ECG monitor. By applying k-means clustering on HR, HRV and movement information obtained from cardiac patients, we obtained 3 clusters in inactive state and one cluster in active state. Two clusters in inactive state characterized by - a) high HR and low HRV b) low HRV and low HR, could be inferred as pathological with abnormal autonomic function. Further, activity information was significant in differentiating between the normal cluster found in active and an abnormal cluster found in inactive states, both with low HRV. This indicates that the activity information must be taken into account while interpreting HR and HRV information.

Ethnic differences in pain and pain management

PubMed Central

Campbell, Claudia M; Edwards, Robert R

2012-01-01

SUMMARY Considerable evidence demonstrates substantial ethnic disparities in the prevalence, treatment, progression and outcomes of pain-related conditions. Elucidating the mechanisms underlying these group differences is of crucial importance in reducing and eliminating disparities in the pain experience. Over recent years, accumulating evidence has identified a variety of processes, from neurophysiological factors to structural elements of the healthcare system, that may contribute to shaping individual differences in pain. For example, the experience of pain differentially activates stress-related physiological responses across various ethnic groups, members of different ethnic groups appear to use differing coping strategies in managing pain complaints, providers’ treatment decisions vary as a function of patient ethnicity and pharmacies in predominantly minority neighborhoods are far less likely to stock potent analgesics. These diverse factors, and others may all play a role in facilitating elevated levels of pain-related suffering among individuals from ethnic minority backgrounds. Here, we present a brief, nonexhaustive review of the recent literature and potential physiological and sociocultural mechanisms underlying these ethnic group disparities in pain outcomes. PMID:23687518

Clinical implications of parallel visual pathways.

PubMed

Bassi, C J; Lehmkuhle, S

1990-02-01

Visual information travels from the retina to visual cortical areas along at least two parallel pathways. In this paper, anatomical and physiological evidence is presented to demonstrate the existence of, and trace these two pathways throughout the visual systems of the cat, primate, and human. Physiological and behavioral experiments are discussed which establish that these two pathways are differentially sensitive to stimuli that vary in spatial and temporal frequency. One pathway (M-pathway) is more sensitive to coarse visual form that is modulated or moving at fast rates, whereas the other pathway (P-pathway) is more sensitive to spatial detail that is stationary or moving at slow rates. This difference between the M- and P-pathways is related to some spatial and temporal effects observed in humans. Furthermore, evidence is presented that certain diseases selectively comprise the functioning of M- or P-pathways (i.e., glaucoma, Alzheimer's disease, and anisometropic amblyopia), and some of the spatial and temporal deficits observed in these patients are presented within the context of the dysfunction of the M- or P-pathway.

Physiological and physiopathological aspects of connexins and communicating gap junctions in spermatogenesis

PubMed Central

Pointis, Georges; Gilleron, Jérome; Carette, Diane; Segretain, Dominique

2010-01-01

Spermatogenesis is a highly regulated process of germ cell proliferation and differentiation, starting from spermatogonia to spermatocytes and giving rise to spermatids, the future spermatozoa. In addition to endocrine regulation, testicular cell–cell interactions are essential for spermatogenesis. This precise control is mediated through paracrine/autocrine pathways, direct intercellular contacts and through intercellular communication channels, consisting of gap junctions and their constitutive proteins, the connexins. Gap junctions are localized between adjacent Leydig cells, between Sertoli cells and between Sertoli cells and specific germ cells. This review focuses on the distribution of connexins within the seminiferous epithelium, their participation in gap junction channel formation, the control of their expression and the physiological relevance of these junctions in both the Sertoli–Sertoli cell functional synchronization and the Sertoli–germ cell dialogue. In this review, we also discuss the potential implication of disrupted connexin in testis cancer, since impaired expression of connexin has been described as a typical feature of tumoral proliferation. PMID:20403873