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Intramuscular Pressure of Human Tibialis Anterior Muscle Reflects in vivo Muscular Activity
Araştırma Makalesi

Araştırma Makalesi
Open Access
Kaynak :
Aperta - TÜBİTAK Açık Arşivi
Dergi:
FRONTIERS IN PHYSIOLOGY
Yazar(lar) :
Kenton R Kaufman , William Litchy , Krista Coleman-Wood , Swati Chopra , Brenda L Davies , Filiz Ates
Yıl :
2019
FRONTIERS IN PHYSIOLOGY
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Intramuscular pressure (IMP) is the fluid hydrostatic pressure generated within a muscle and reflects the mechanical forces produced by a muscle. By providing accurate quantification of interstitial fluid pressure, the measurement of IMP may be useful to detect changes in skeletal muscle function not identified with established techniques. However, the relationship between IMP and muscle activity has never been studied in vivo in healthy human muscles. To determine if IMP is able to evaluate electromechanical performance of muscles in vivo, we tested the following hypotheses on the human tibialis anterior (TA) muscle: (i) IMP increases in proportion to muscle activity as measured by electrical [Compound Muscle Action Potential (CMAP)] and mechanical (ankle torque) responses to activation by nerve stimulation and (ii) the onset delay of IMP (IMPD) is shorter than the ankle torque electromechanical delay (EMD). Twelve healthy adults [six females; mean (SD) = 28.1 (5.0) years old] were recruited. Ankle torque, TA IMP, and CMAP responses were collected during maximal stimulation of the fibular nerve at different intensity levels of electrical stimulation, and at different frequencies of supramaximal stimulation, i.e., at 2, 5, 10, and 20 Hz. The IMP response at different stimulation intensities was correlated with the CMAP amplitude (r(2) = 0.94). The area of the IMP response at different stimulation intensities was also significantly correlated with the area of the CMAP (r(2) = 0.93). Increasing stimulation intensity resulted in an increase of the IMP response (P < 0.001). Increasing stimulation frequency caused torque (P < 0.001) as well as the IMP (P < 0.001) to increase. The ankle torque EMD [median (interquartile range) = 41.8 (14.4) ms] was later than the IMPD [33.0 (23.6) ms]. These findings support the hypotheses and suggest that IMP captures active mechanical properties of muscle in vivo and can be used to detect muscular changes due to drugs, diseases, or aging.
DOI : 10.3389/fphys.2019.00196
Sayı :10
2
Principles of the Mechanism for Epimuscular Myofascial Loads Leading to Non-uniform Strain Distributions Along Muscle Fiber Direction: Finite Element Modeling
Araştırma Makalesi

Araştırma Makalesi
Open Access
Kaynak :
Aperta - TÜBİTAK Açık Arşivi
Dergi:
FRONTIERS IN PHYSIOLOGY
Yazar(lar) :
Can A Yucesoy , Alican Onur Cankaya , Uluc Pamuk
Yıl :
2020
FRONTIERS IN PHYSIOLOGY
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Sarcomere lengths and their changes are key determinants of muscle active force production. Recent studies indicate inhomogeneity of sarcomere lengths within the muscle. Studies utilizing magnetic resonance imaging (MRI) analyses for quantifying local muscle tissue strains and diffusion tensor imaging (DTI) analyses allowing for determination of their components along muscle fascicles show that those length changes can be non-uniform. Specifically, two questions arise regarding the muscle's length change heterogeneities along the muscle fiber direction: (1) How can a passively lengthened muscle show shortened regions? (2) How can an isometric contracting muscle show lengthened parts? Using finite element modeling and studying principles of the mechanism of strain heterogeneity along the muscle fiber direction, the aim was to test the following hypothesis: epimuscular myofascial loads can lead locally to strains opposing those elsewhere within the muscle that are determined by the globally imposed conditions. The geometry of the model was defined by the contour of a longitudinal slice of the rat extensor digitorum longus (EDL) muscle belly. Three models were studied: (1) isolated muscle (muscle modeled fully isolated from its surroundings) and models aiming at representing the principles of a muscle in itsin vivocontext including (2) extramuscularly connected muscle (muscle's connections to non-muscular structures are modeled exclusively) and (3) epimuscularly connected muscle (additionally muscle's connections to neighboring muscle are modeled). Three cases were studied: passive isometric muscle with imposed relative position change (Case I), passive lengthened muscle (Case II), and active isometric muscle with imposed relative position change (Case III). The findings indicated non-uniform strains for all models except for zero strain in model (1) in Case I, but models (2) and (3) also showed strains opposing the imposed effect. Case I: model (3) showed shortened and lengthened sections (up to 35.3%), caused exclusively by imposed relative position change. Case II: models (2) and (3) showed shortened sections (up to 12.7 and 19.5%, respectively) in addition to lengthened sections. Case III: models (2) and (3) showed lengthened sections (up to 5 and 23.4%, respectively) in addition to shortened sections. These effects get more pronounced with stiffer epimuscular connections. Assessments of forces exerted on the muscle by the epimuscular connections showed that such strain heterogeneities are ascribed to epimuscular myofascial loads determined by muscle relative position changes.
DOI : 10.3389/fphys.2020.00789
Sayi :11
Sınıflandırma :
3
Extrasynaptic exocytosis and its mechanisms: a source of molecules mediating volume transmission in the nervous system
Araştırma Makalesi

Araştırma Makalesi
Open Access
Kaynak :
Aperta - TÜBİTAK Açık Arşivi
Dergi:
FRONTIERS IN PHYSIOLOGY
Yazar(lar) :
Francisco F De-Miguel , Citlali Trueta
Yıl :
2012
FRONTIERS IN PHYSIOLOGY
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We review the evidence of exocytosis from extrasynaptic sites in the soma, dendrites, and axonal varicosities of central and peripheral neurons of vertebrates and invertebrates, with emphasis on somatic exocytosis, and how it contributes to signaling in the nervous system. The finding of secretory vesicles in extrasynaptic sites of neurons, the presence of signaling molecules (namely transmitters or peptides) in the extracellular space outside synaptic clefts, and the mismatch between exocytosis sites and the location of receptors for these molecules in neurons and glial cells, have long suggested that in addition to synaptic communication, transmitters are released, and act extrasynaptically. The catalog of these molecules includes low molecular weight transmitters such as monoamines, acetylcholine, glutamate, gama-aminobutiric acid (GABA), adenosine-5-triphosphate (ATP), and a list of peptides including substance P, brain-derived neurotrophic factor (BDNF), and oxytocin. By comparing the mechanisms of extrasynaptic exocytosis of different signaling molecules by various neuron types we show that it is a widespread mechanism for communication in the nervous system that uses certain common mechanisms, which are different from those of synaptic exocytosis but similar to those of exocytosis from excitable endocrine cells. Somatic exocytosis has been measured directly in different neuron types. It starts after high-frequency electrical activity or long experimental depolarizations and may continue for several minutes after the end of stimulation. Activation of Ltype calcium channels, calcium release from intracellular stores and vesicle transport towards the plasma membrane couple excitation and exocytosis from small clear or large dense core vesicles in release sites lacking postsynaptic counterparts. The presence of synaptic and extrasynaptic exocytosis endows individual neurons with a wide variety of time and space dependent communication possibilities. Extrasynaptic exocytosis may be the major source of signaling molecules producing volume transmission and by doing so may be part of a long duration signaling mode in the nervous system.
DOI : 10.3389/fphys.2012.00319
Sayi :3
Sınıflandırma :
4
Drug Repositioning for Effective Prostate Cancer Treatment
Araştırma Makalesi

Araştırma Makalesi
Open Access
Kaynak :
Aperta - TÜBİTAK Açık Arşivi
Dergi:
FRONTIERS IN PHYSIOLOGY
Yazar(lar) :
Adil Mardinoglu , Kazim Y Arga , Mathias Uhlen , Jens Nielsen , Jan Boren , Morten Grotli , Beste Turanli
Yıl :
2018
FRONTIERS IN PHYSIOLOGY
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Drug repositioning has gained attention from both academia and pharmaceutical companies as an auxiliary process to conventional drug discovery. Chemotherapeutic agents have notorious adverse effects that drastically reduce the life quality of cancer patients so drug repositioning is a promising strategy to identify non-cancer drugs which have anti-cancer activity as well as tolerable adverse effects for human health. There are various strategies for discovery and validation of repurposed drugs. In this review, 25 repurposed drug candidates are presented as result of different strategies, 15 of which are already under clinical investigation for treatment of prostate cancer (PCa). To date, zoledronic acid is the only repurposed, clinically used, and approved non-cancer drug for PCa. Anti-cancer activities of existing drugs presented in this review cover diverse and also known mechanisms such as inhibition of mTOR and VEGFR2 signaling, inhibition of PI3K/Akt signaling, COX and selective COX-2 inhibition, NF-kappa B inhibition, Wnt/beta - Catenin pathway inhibition, DNMT1 inhibition, and GSK-3 beta inhibition. In addition to monotherapy option, combination therapy with current anti-cancer drugs may also increase drug efficacy and reduce adverse effects. Thus, drug repositioning may become a key approach for drug discovery in terms of time- and cost-efficiency comparing to conventional drug discovery and development process.
DOI : 10.3389/fphys.2018.00500
Sayi :9
Sınıflandırma :
5
Mechanical regulation of cardiac development
Araştırma Makalesi

Araştırma Makalesi
Open Access
Kaynak :
Aperta - TÜBİTAK Açık Arşivi
Dergi:
FRONTIERS IN PHYSIOLOGY
Yazar(lar) :
Huseyin C Yalcin , Jonathan T Butcher , Stephanie E Lindsey
Yıl :
2014
FRONTIERS IN PHYSIOLOGY
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Mechanical forces are essential contributors to and unavoidable components of cardiac formation, both inducing and orchestrating local and global molecular and cellular changes. Experimental animal studies have contributed substantially to understanding the mechanobiology of heart development. More recent integration of high-resolution imaging modalities with computational modeling has greatly improved our quantitative understanding of hemodynamic flow in heart development. Merging these latest experimental technologies with molecular and genetic signaling analysis will accelerate our understanding of the relationships integrating mechanical and biological signaling for proper cardiac formation. These advances will likely be essential for clinically translatable guidance for targeted interventions to rescue malforming hearts and/or reconfigure malformed circulations for optimal performance. This review summarizes our current understanding on the levels of mechanical signaling in the heart and their roles in orchestrating cardiac development.
DOI : 10.3389/fphys.2014.00318
Sayi :5
Sınıflandırma :
6
Intramuscular Pressure of Tibialis Anterior Reflects Ankle Torque but Does Not Follow Joint Angle-Torque Relationship
Araştırma Makalesi

Araştırma Makalesi
Open Access
Kaynak :
Aperta - TÜBİTAK Açık Arşivi
Dergi:
FRONTIERS IN PHYSIOLOGY
Yazar(lar) :
Kenton R Kaufman , William J Litchy , Krista Coleman-Wood , Swati Chopra , Brenda L Davies , Filiz Ates
Yıl :
2018
FRONTIERS IN PHYSIOLOGY
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Intramuscular pressure (IMP) is the hydrostatic fluid pressure that is directly related to muscle force production. Electromechanical delay (EMD) provides a link between mechanical and electrophysiological quantities and IMP has potential to detect local electromechanical changes. The goal of this study was to assess the relationship of IMP with the mechanical and electrical characteristics of the tibialis anterior muscle (TA) activity at different ankle positions. We hypothesized that (1) the TA IMP and the surface EMG (sEMG) and fine-wire EMG (fwEMG) correlate to ankle joint torque, (2) the isometric force of TA increases at increased muscle lengths, which were imposed by a change in ankle angle and IMP follows the length-tension relationship characteristics, and (3) the electromechanical delay (EMD) is greater than the EMD of IMP during isometric contractions. Fourteen healthy adults [7 female; mean (SD) age = 26.9 (4.2) years old with 25.9 (5.5) kg/m(2) body mass index] performed (i) three isometric dorsiflexion (DF) maximum voluntary contraction (MVC) and (ii) three isometric DF ramp contractions from 0 to 80% MVC at rate of 15% MVC/second at DF, Neutral, and plantarflexion (PF) positions. Ankle torque, IMP, TA fwEMG, and TA sEMG were measured simultaneously. The IMP, fwEMG, and sEMG were significantly correlated to the ankle torque during ramp contractions at each ankle position tested. This suggests that IMP captures in vivo mechanical properties of active muscles. The ankle torque changed significantly at different ankle positions however, the IMP did not reflect the change. This is explained with the opposing effects of higher compartmental pressure at DF in contrast to the increased force at PF position. Additionally, the onset of IMP activity is found to be significantly earlier than the onset of force which indicates that IMP can be designed to detect muscular changes in the course of neuromuscular diseases impairing electromechanical transmission.
DOI : 10.3389/fphys.2018.00022
Sayı :9
7
The Role of Peptide Hormones in Insect Lipid Metabolism
Araştırma Makalesi

Araştırma Makalesi
Open Access
Kaynak :
Aperta - TÜBİTAK Açık Arşivi
Dergi:
FRONTIERS IN PHYSIOLOGY
Yazar(lar) :
Umut Toprak
Yıl :
2020
FRONTIERS IN PHYSIOLOGY
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Lipids are the primary storage molecules and an essential source of energy in insects during reproduction, prolonged periods of flight, starvation, and diapause. The coordination center for insect lipid metabolism is the fat body, which is analogous to the vertebrate adipose tissue and liver. The fat body is primarily composed of adipocytes, which accumulate triacylglycerols in intracellular lipid droplets. Genomics and proteomics, together with functional analyses, such as RNA interference and CRISPR/Cas9-targeted genome editing, identified various genes involved in lipid metabolism and elucidated their functions. However, the endocrine control of insect lipid metabolism, in particular the roles of peptide hormones in lipogenesis and lipolysis are relatively less-known topics. In the current review, the neuropeptides that directly or indirectly affect insect lipid metabolism are introduced. The primary lipolytic and lipogenic peptide hormones are adipokinetic hormone and the brain insulin-like peptides (ILP2, ILP3, ILP5). Other neuropeptides, such as insulin-growth factor ILP6, neuropeptide F, allatostatin-A, corazonin, leucokinin, tachykinins and limostatin, might stimulate lipolysis, while diapause hormone-pheromone biosynthesis activating neuropeptide, short neuropeptide F, CCHamide-2, and the cytokines Unpaired 1 and Unpaired 2 might induce lipogenesis. Most of these peptides interact with one another, but mostly with insulin signaling, and therefore affect lipid metabolism indirectly. Peptide hormones are also involved in lipid metabolism during reproduction, flight, diapause, starvation, infections and immunity; these are also highlighted. The review concludes with a discussion of the potential of lipid metabolism-related peptide hormones in pest management.
DOI : 10.3389/fphys.2020.00434
Sayi :11
Sınıflandırma :
8
From Experiments to Simulation: Shear-Induced Responses of Red Blood Cells to Different Oxygen Saturation Levels
Araştırma Makalesi

Araştırma Makalesi
Open Access
Kaynak :
Aperta - TÜBİTAK Açık Arşivi
Dergi:
FRONTIERS IN PHYSIOLOGY
Yazar(lar) :
Ozlem Yalcin , Aysenur Eser , Ali Cenk Aksu , Senol Piskin , Elif Ugurel
Yıl :
2020
FRONTIERS IN PHYSIOLOGY
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Red blood cells (RBC) carry and deliver oxygen (O-2) to peripheral tissues through different microcirculatory regions where they are exposed to various levels of shear stress (SS). O-2 affinity of hemoglobin (Hb) decreases as the blood enters the microcirculation. This phenomenon determines Hb interactions with RBC membrane proteins that can further regulate the structure of cytoskeleton and affect the mechanical properties of cells. The goal of this study is to evaluate shear-induced RBC deformability and simulate RBC dynamics in blood flow under oxygenated and deoxygenated conditions. Venous blood samples from healthy donors were oxygenated with ambient air or deoxygenated with 100% nitrogen gas for 10 min and immediately applied into an ektacytometer (LORRCA). RBC deformability was measured before and after the application of continuous 5 Pa SS for 300 s by LORRCA and recorded as elongation index (EI) values. A computational model was generated for the simulation of blood flow in a real carotid artery section. EI distribution throughout the artery and its relationships with velocity, pressure, wall SS and viscosity were determined by computational tools. RBC deformability significantly increased in deoxygenation compared to oxygenated state both before and after 5 Pa SS implementation (p < 0.0001). However, EI values after continuous SS were not significant at higher SS levels (>5.15 Pa) in deoxygenated condition. Simulation results revealed that the velocity gradient dominates the generation of SS and the shear thinning effect of blood has a minor effect on it. Distribution of EI was calculated during oxygenation/deoxygenation which is 5-10 times higher around the vessel wall compared to the center of the lumen for sections of the pulsatile flow profile. The extent of RBC deformability increases as RBCs approach to the vessel wall in a real 3D artery model and this increment is higher for deoxygenated condition compared to the oxygenated state. Hypoxia significantly increases shear-induced RBC deformability. RBCs could regulate their own mechanical properties in blood flow by increasing their deformability in hypoxic conditions. Computational tools can be applied for defining hypoxia-mediated RBC deformability changes to monitor blood flow in hypoxic tissues.
DOI : 10.3389/fphys.2019.01559
Sayi :10
Sınıflandırma :
9
Time Irreversibility of Resting-State Activity in the Healthy Brain and Pathology
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Araştırma Makalesi
Open Access
Kaynak :
Aperta - TÜBİTAK Açık Arşivi
Dergi:
FRONTIERS IN PHYSIOLOGY
Yazar(lar) :
David Papo , Lutfu Hanoglu , Tuba Akturk , Bahar Guntekin , Massimiliano Zanin
Yıl :
2020
FRONTIERS IN PHYSIOLOGY
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Characterizing brain activity at rest is of paramount importance to our understanding both of general principles of brain functioning and of the way brain dynamics is affected in the presence of neurological or psychiatric pathologies. We measured the time-reversal symmetry of spontaneous electroencephalographic brain activity recorded from three groups of patients and their respective control group under two experimental conditions (eyes open and closed). We evaluated differences in time irreversibility in terms of possible underlying physical generating mechanisms. The results showed that resting brain activity is generically time-irreversible at sufficiently long time scales, and that brain pathology is generally associated with a reduction in time-asymmetry, albeit with pathology-specific patterns. The significance of these results and their possible dynamical etiology are discussed. Some implications of the differential modulation of time asymmetry by pathology and experimental condition are examined.
DOI : 10.3389/fphys.2019.01619
Sayi :10
Sınıflandırma :
10
Feeding Faba Beans (Vicia faba L.) Reduces Myocyte Metabolic Activity in Grass Carp (Ctenopharyngodon idellus)
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Jing-jing Tian , Bing Fu , Er-meng Yu , Yu-ping Li , Yun Xia , Zhi-fei Li , Kai Zhang , Wang-bao Gong , De-guang Yu , Guang-jun Wang , Jun Xie
Yıl :
2020
Frontiers in Physiology
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In this study, we aimed to explore the effects of faba bean (Vicia faba L.) on the energy metabolism of grass carp (Ctenopharyngodon idellus). A total of 180 fish (∼2900 g) were randomly assigned to six tanks (2.5 × 2.5 × 1.2 m; 30 individuals per tank) and fed either faba bean (Vicia faba L.) or a commercial diet for 120 days (3% body weight, twice per day). The results showed that faba bean-fed grass carp (FBFG) had significantly lower growth and higher fat accumulation in the mesenteric adipose tissue and hepatopancreas than commercial diet-fed grass carp (CDFG). Compared with CDFG, FBFG exhibited no significant difference in proximate composition of the muscle; however, an obvious decrease in muscle fiber size and significantly higher hardness, chewiness, and gumminess were observed. Transcriptome results showed that a total of 197 genes were differentially regulated in the dorsal muscle. Down-regulated genes included four genes annotated with myocyte development and 12 transcripts annotated with components of myofibrils. In addition, the FBFG group exhibited significantly lower expression of genes associated with oxygen transport, the mitochondrial respiratory chain, and creatine metabolism, suggesting reduced energy availability in the muscle of the FBFG. Moreover, using western-blotting and enzyme assays, we found decreased protein levels in the mitochondrial electron transport respiratory chain and creatine metabolism activities, as well as increased expression of autophagy marker protein levels, in the muscle of FBFG. Overall, our results suggest that an abnormal energy distribution may exist in grass carps after feeding with faba bean, which is reflected by a mass of fat deposition in the adipose tissue and hepatopancreas and subdued metabolic activity in the muscle.
DOI : 10.3389/fphys.2020.00391
Anahtar Kelimeler : crisp grass carp, energy status, faba bean, myocyte development, RNA-seq
ISSN: 1664-042X
Cilt: 11
Sınıflandırma :
11
Metabolic Changes Associated With Muscle Expression of SOD1G93A
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Gabriella Dobrowolny , Gabriella Dobrowolny , Elisa Lepore , Elisa Lepore , Martina Martini , Laura Barberi , Abigail Nunn , Bianca Maria Scicchitano , Antonio Musarò , Antonio Musarò
Yıl :
2018
Frontiers in Physiology
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Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disorder, classified into sporadic or familial forms and characterized by motor neurons death, muscle atrophy, weakness, and paralysis. Among the familial cases of ALS, approximately 20% are caused by dominant mutations in the gene coding for superoxide dismutase (SOD1) protein. Of note, mutant SOD1 toxicity is not necessarily limited to the central nervous system. ALS is indeed a multi-systemic and multifactorial disease that affects whole body physiology and induces severe metabolic changes in several tissues, including skeletal muscle. Nevertheless, whether alterations in the plasticity, heterogeneity, and metabolism of muscle fibers are the result of motor neuron degeneration or alternatively occur independently of it remain to be elucidated. To address this issue, we made use of a mouse model (MLC/SOD1G93A) that overexpresses the SOD1 mutant gene selectively in skeletal muscle. We found an alteration in the metabolic properties of skeletal muscle characterized by alteration in fiber type composition and metabolism. Indeed, we observed an alteration of muscle glucose metabolism associated with the induction of Phosphofructokinases and Pyruvate dehydrogenase kinase 4 expression. The upregulation of Pyruvate dehydrogenase kinase 4 led to the inhibition of Pyruvate conversion into Acetyl-CoA. Moreover, we demonstrated that the MLC/SOD1G93A transgene was associated with an increase of lipid catabolism and with the inhibition of fat deposition inside muscle fibers. All together these data demonstrate that muscle expression of the SOD1G93A gene induces metabolic changes, along with a preferential use of lipid energy fuel by muscle fibers. We provided evidences that muscle metabolic alterations occurred before disease symptoms and independently of motor neuron degeneration, indicating that skeletal muscle is likely an important therapeutic target in ALS.
DOI : 10.3389/fphys.2018.00831
Anahtar Kelimeler : skeletal muscle, SOD1G93A, muscle fiber types, metabolic alterations, oxidative stress
ISSN: 1664-042X
Cilt: 9
Sınıflandırma :
12
Extrasynaptic neurotransmission as a way of modulating neuronal functions.
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Francisco Fernandez De-Miguel , Kjell eFuxe
Yıl :
2012
Frontiers in Physiology
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Kaydet Alıntıla
DOI : 10.3389/fphys.2012.00016
Anahtar Kelimeler : Serotonin, volume transmission, somatic exocytosis, synapse, extrasynaptic transmission, chemical transmission
ISSN: 1664-042X
Cilt: 3
Sınıflandırma :
13
Functional Segregation within the Muscles of Aquatic Propulsion in the Asiatic Water Monitor (Varanus salvator)
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Bruce Arthur Young , Jessica Dumais , Nicholas John , Brandon Lyons , Andrew Macduff , Matthew Most , Nathan A. Reiser , Peter J Reiser
Yıl :
2016
Frontiers in Physiology
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Kaydet Alıntıla
Water monitor lizards (Varanus salvator) swim using sinusoidal oscillations generated at the base of their long (50% of total body length) tail. In an effort to determine which level of the structural/organizational hierarchy of muscle is associated with functional segregation between the muscles of the tail base, an array of muscle features — myosin heavy chain profiles, enzymatic fiber types, twitch and tetanic force production, rates of fatigue, muscle compliance, and electrical activity patterns — were quantitated. The two examined axial muscles, longissimus and iliocaudalis, were generally similar at the molecular, biochemical, and physiological levels, but differed at the biomechanics level and in their activation pattern. The appendicular muscle examined, caudofemoralis, differed from the axial muscles particularly at the molecular and physiological levels, and it exhibited a unique compliance profile and pattern of electrical activation. There were some apparent contradictions between the different structural/organizational levels examined. These contradictions, coupled with a unique myosin heavy chain profile, lead to the hypothesis that there are previously un-described molecular/biochemical specializations within varanid skeletal muscles.
DOI : 10.3389/fphys.2016.00380
Anahtar Kelimeler : Electromyography, myosin heavy chain, appendicular muscles, axial muscles, Work loops, Muscle histochemistry
ISSN: 1664-042X
Cilt: 7
Sınıflandırma :
14
Aging in Rats Differentially Affects Markers of Transcriptional and Translational Capacity in Soleus and Plantaris Muscle
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Christopher B. Mobley , Petey W. Mumford , Wesley C. Kephart , Cody T. Haun , Angelia M. Holland , Darren T. Beck , Darren T. Beck , Jeffrey S. Martin , Jeffrey S. Martin , Kaelin C. Young , Kaelin C. Young , Richard G. Anderson , Romil K. Patel , Gillis L. Langston , Ryan P. Lowery , Ryan P. Lowery , Jacob M. Wilson , Michael D. Roberts , Michael D. Roberts
Yıl :
2017
Frontiers in Physiology
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Alterations in transcriptional and translational mechanisms occur during skeletal muscle aging and such changes may contribute to age-related atrophy. Herein, we examined markers related to global transcriptional output (i.e., myonuclear number, total mRNA and RNA pol II levels), translational efficiency [i.e., eukaryotic initiation and elongation factor levels and muscle protein synthesis (MPS) levels] and translational capacity (ribosome density) in the slow-twitch soleus and fast-twitch plantaris muscles of male Fischer 344 rats aged 3, 6, 12, 18, and 24 months (n = 9–10 per group). We also examined alterations in markers of proteolysis and oxidative stress in these muscles (i.e., 20S proteasome activity, poly-ubiquinated protein levels and 4-HNE levels). Notable plantaris muscle observations included: (a) fiber cross sectional area (CSA) was 59% (p < 0.05) and 48% (p < 0.05) greater in 12 month vs. 3 month and 24 month rats, respectively, suggesting a peak lifetime value near 12 months and age-related atrophy by 24 months, (b) MPS levels were greatest in 18 month rats (p < 0.05) despite the onset of atrophy, (c) while regulators of ribosome biogenesis [c-Myc and upstream binding factor (UBF) protein levels] generally increased with age, ribosome density linearly decreased from 3 months of age and RNA polymerase (Pol) I protein levels were lowest in 24 month rats, and d) 20S proteasome activity was robustly up-regulated in 6 and 24 month rats (p < 0.05). Notable soleus muscle observations included: (a) fiber CSA was greatest in 6 month rats and was maintained in older age groups, and (b) 20S proteasome activity was modestly but significantly greater in 24 month vs. 3/12/18 month rats (p < 0.05), and (c) total mRNA levels (suggestive of transcriptional output) trended downward in older rats despite non-significant between-group differences in myonuclear number and/or RNA Pol II protein levels. Collectively, these findings suggest that plantaris, not soleus, atrophy occurs following 12 months of age in male Fisher rats and this may be due to translational deficits (i.e., changes in MPS and ribosome density) and/or increases in proteolysis rather than increased oxidative stress and/or alterations in global transcriptional mechanisms.
DOI : 10.3389/fphys.2017.00518
Anahtar Kelimeler : fast-twitch muscle, aging, atrophy, muscle protein synthesis, ribosome
ISSN: 1664-042X
Cilt: 8
15
A N-terminal Truncated Intracellular Isoform of Matrix Metalloproteinase-2 Impairs Contractility of Mouse Myocardium
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
David H Lovett , Charles eChu , Guanying eWang , Mark B Ratcliffe , Anthony J Baker
Yıl :
2014
Frontiers in Physiology
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The full-length isoform of matrixmetalloproteinase-2 (FL-MMP-2) plays a role in turnover of the cardiac extracellular matrix. FL-MMP-2 is also present intracellularly in association with sarcomeres and, in the setting of oxidative stress, cleaves myofilament proteins with resultant impaired contractility. Recently, a novel N-terminal truncated MMP-2 isoform (NTT-MMP-2) generated during oxidative stress was identified and shown to induce severe systolic failure; however, the injury mechanisms remained unclear. In this study, cardiac-specific NTT-MMP-2 transgenic mice were used to determine the physiological effects of NTT-MMP-2 on: force development of intact myocardium; the function of cardiac myofilaments in demembranated myocardium; and on intracellular Ca2+ transients in isolated myocytes. We related the contractile defects arising from NTT-MMP-2 expression to the known intracellular locations of NTT-MMP-2 determined using immunohistochemistry. Comparison was made with the pathophysiology arising from cardiac-specific FL-MMP-2 transgenic mice. Consistent with previous studies, FL-MMP-2 was localized to myofilaments, while NTT-MMP-2 was concentrated within subsarcolemmal mitochondria and to sites in register with the Z-line. NTT-MMP-2 expression caused a 50% reduction of force development by intact myocardium. However, NTT-MMP-2 expression did not reduce myofilament force development, consistent with the lack of NTT-MMP-2 localization to myofilaments. NTT-MMP-2 expression caused a 50% reduction in the amplitude of Ca2+ transients, indicating impaired activation. Conclusions: Unlike FL-MMP-2, NTT-MMP-2 does not mediate myofilament damage. Instead, NTT-MMP-2 causes impaired myocyte activation, which may involve effects due to localization in mitochondria and/or to transverse tubules affecting Ca2+ transients. Thus, FL-MMP-2 and NTT-MMP-2 have discrete intracellular locations and mediate different intracellular damage to cardiac myocytes.
DOI : 10.3389/fphys.2014.00363
Anahtar Kelimeler : Heart Failure, Contraction, remodeling, MMP-2, Myofilament, Ca2+ transient
ISSN: 1664-042X
Cilt: 5
Sınıflandırma :
16
Candidate Heterotaxy Gene FGFR4 Is Essential for Patterning of the Left-Right Organizer in Xenopus
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Emily Sempou , Osaamah Ali Lakhani , Sarah Amalraj , Mustafa K. Khokha
Yıl :
2018
Frontiers in Physiology
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Congenital heart disease (CHD) is the most common birth defect, yet its genetic causes continue to be obscure. Fibroblast growth factor receptor 4 (FGFR4) recently emerged in a large patient exome sequencing study as a candidate disease gene for CHD and specifically heterotaxy. In heterotaxy, patterning of the left-right (LR) body axis is compromised, frequently leading to defects in the heart's LR architecture and severe CHD. FGF ligands like FGF8 and FGF4 have been previously implicated in LR development with roles ranging from formation of the laterality organ [LR organizer (LRO)] to the transfer of asymmetry from the embryonic midline to the lateral plate mesoderm (LPM). However, much less is known about which FGF receptors (FGFRs) play a role in laterality. Here, we show that the candidate heterotaxy gene FGFR4 is essential for proper organ situs in Xenopus and that frogs depleted of fgfr4 display inverted cardiac and gut looping. Fgfr4 knockdown causes mispatterning of the LRO even before cilia on its surface initiate symmetry-breaking fluid flow, indicating a role in the earliest stages of LR development. Specifically, fgfr4 acts during gastrulation to pattern the paraxial mesoderm, which gives rise to the lateral pre-somitic portion of the LRO. Upon fgfr4 knockdown, the paraxial mesoderm is mispatterned in the gastrula and LRO, and crucial genes for symmetry breakage, like coco, xnr1, and gdf3 are subsequently absent from the lateral portions of the organizer. In summary, our data indicate that FGF signaling in mesodermal LRO progenitors defines cell fates essential for subsequent LR patterning.
DOI : 10.3389/fphys.2018.01705
Anahtar Kelimeler : FGF signaling, left-right patterning, gastrulation, Xenopus, congenital heart disease, heterotaxy
ISSN: 1664-042X
Cilt: 9
Sınıflandırma :
17
Interplay Between Peripheral and Central Inflammation in Autism Spectrum Disorders: Possible Nutritional and Therapeutic Strategies
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Claudia Cristiano , Adriano Lama , Francesca Lembo , Maria P. Mollica , Antonio Calignano , Giuseppina Mattace Raso
Yıl :
2018
Frontiers in Physiology
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Pre- and post-natal factors can affect brain development and function, impacting health outcomes with particular relevance to neurodevelopmental diseases, such as autism spectrum disorders (ASDs). Maternal obesity and its associated complications have been related to the increased risk of ASDs in offspring. Indeed, animals exposed to maternal obesity or high fat diets are prone to social communication impairment and repetitive behavior, the hallmarks of autism. During development, fatty acids and sugars, as well as satiety hormones, like insulin and leptin, and inflammatory factors related to obesity-induced low grade inflammation, could play a role in the impairment of neuroendocrine system and brain neuronal circuits regulating behavior in offspring. On the other side, post-natal factors, such as mode of delivery, stress, diet, or antibiotic treatment are associated to a modification of gut microbiota composition, perturbing microbiota-gut-brain axis. Indeed, the interplay between the gastrointestinal tract and the central nervous system not only occurs through neural, hormonal, and immune pathways, but also through microbe-derived metabolic products. The modification of unhealthy perinatal and postnatal environment, manipulation of gut microbiota, nutritional, and dietary interventions could represent possible strategies in preventing or limiting ASDs, through targeting inflammatory process and gut microbiota.
DOI : 10.3389/fphys.2018.00184
Anahtar Kelimeler : inflammation, obesity, gut-brain axis, therapeutics
ISSN: 1664-042X
Cilt: 9
Sınıflandırma :
18
Plasmacytoid dendritic cells in atherosclerosis
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Yvonne eDöring , Alma eZernecke
Yıl :
2012
Frontiers in Physiology
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Atherosclerosis, a chronic inflammatory disease of the vessel wall and the underlying cause of cardiovascular disease, is initiated and maintained by innate and adaptive immunity. Accumulating evidence suggests an important contribution of autoimmune responses to this disease. Plasmacytoid dendritic cells (pDCs), a specialized cell type known to produce large amounts of type I interferons in response to bacterial and viral infections, have recently been revealed to play important roles in atherosclerosis. For example, the development of autoimmune complexes consisting of self-DNA and antimicrobial peptides, which trigger chronic type I interferon production by pDCs, promote early atherosclerotic lesion formation. pDCs and pDC-derived type I interferons can induce the induce the maturation of conventional DCs and macrophages, and the development of auto-reactive B cells and antibody production. These mechanisms, known to play a role in the pathogenesis of other autoimmune diseases such as SLE and psoriasis, may also affect the development and progression of atherosclerotic lesion formation. This review discusses emerging evidence showing a role for pDCs in the onset and progression of atherosclerosis.
DOI : 10.3389/fphys.2012.00230
Anahtar Kelimeler : Atherosclerosis, type I interferon, plasmacytoid dendritic cells
ISSN: 1664-042X
Cilt: 3
Sınıflandırma :
19
Visual Ecology and the Development of Visually Guided Behavior in the Cuttlefish
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Anne-Sophie Darmaillacq , Nawel Mezrai , Caitlin E. O'Brien , Ludovic Dickel
Yıl :
2017
Frontiers in Physiology
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Cuttlefish are highly visual animals, a fact reflected in the large size of their eyes and visual-processing centers of their brain. Adults detect their prey visually, navigate using visual cues such as landmarks or the e-vector of polarized light and display intense visual patterns during mating and agonistic encounters. Although much is known about the visual system in adult cuttlefish, few studies have investigated its development and that of visually-guided behavior in juveniles. This review summarizes the results of studies of visual development in embryos and young juveniles. The visual system is the last to develop, as in vertebrates, and is functional before hatching. Indeed, embryonic exposure to prey, shelters or complex background alters postembryonic behavior. Visual acuity and lateralization, and polarization sensitivity improve throughout the first months after hatching. The production of body patterning in juveniles is not the simple stimulus-response process commonly presented in the literature. Rather, it likely requires the complex integration of visual information, and is subject to inter-individual differences. Though the focus of this review is vision in cuttlefish, it is important to note that other senses, particularly sensitivity to vibration and to waterborne chemical signals, also play a role in behavior. Considering the multimodal sensory dimensions of natural stimuli and their integration and processing by individuals offer new exciting avenues of future inquiry.
DOI : 10.3389/fphys.2017.00402
Anahtar Kelimeler : cephalopod, vision, embryo, brain, polarization, camouflage
ISSN: 1664-042X
Cilt: 8
Sınıflandırma :
20
Editorial: The Evolution of Endothermy–From Patterns to Mechanisms
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Elias T. Polymeropoulos , Rebecca Oelkrug , Martin Jastroch , Martin Jastroch
Yıl :
2018
Frontiers in Physiology
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DOI : 10.3389/fphys.2018.00891
Anahtar Kelimeler : endotherms, ectotherms, heterothermy, evolution, thermoregulation, comparative physiology
ISSN: 1664-042X
Cilt: 9
Sınıflandırma :
21
Expression of BACE1 in the Rat Carotid Body
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Chaohong Li , Baosheng Zhao , Ya-nan Fan , Xianglei Jia , Yuzhen Liu
Yıl :
2020
Frontiers in Physiology
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This study explored the expression of BACE1 (β-amyloid precursor protein cleaving enzyme 1) in the rat carotid body and the effect of CIH (cyclic intermittent hypoxia) on the expression of BACE1. We found that BACE1 was expressed in the rat carotid body and located in the nerve endings and type II cells but not in type I cells. CIH reduced BACE1 level in the carotid body, and reoxygenation or ROS scavenger alleviated this reduction. Furthermore, we found that CIH augmented the mRNA level of PGC-1α but attenuated the mRNA level of BACE1 in the carotid body. Taken together, our results suggest that CIH promotes the production of ROS that upregulates the level of PGC-1α, which may in turn inhibits the transcription of BACE1, and that a reduction in the BACE1 level may be related to CIH-induced reversible and ROS-dependent carotid body plasticity. Our study provides a new candidate molecule for further study of the mechanism of carotid body plasticity.
DOI : 10.3389/fphys.2020.00505
Anahtar Kelimeler : carotid body, BACE1, cyclic intermittent hypoxia, plasticity
ISSN: 1664-042X
Cilt: 11
Sınıflandırma :
22
An Overview on Current Non-invasive Diagnostic Devices in Oral Oncology
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Marco Mascitti , Giovanna Orsini , Vincenzo Tosco , Riccardo Monterubbianesi , Andrea Balercia , Angelo Putignano , Maurizio Procaccini , Maurizio Procaccini , Andrea Santarelli , Andrea Santarelli
Yıl :
2018
Frontiers in Physiology
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Oral squamous cell carcinoma (OSCC) is the most common head and neck malignancy, and despite advances in cancer therapies, the overall 5-year survival rate has remained below 50% over the past decades. OSCC is typically preceded by potentially malignant disorders (PMD), but distinguishing high-risk from low-risk PMD is challenging. In the last years, several diagnostic methods as light-based detection systems (LBDS) have been proposed to facilitate the detection of OSCC and PMD. Furthermore, the recent evolution of nanotechnology may provide new opportunities to detect PMD and OSCC at an early stage. Indeed, several preclinical studies showed the potential of nanotechnology to enhance diagnostic accuracy. For these reasons, it is fundamental to conduct studies to evaluate the efficacy of nanotechnology implementation in LBDS. The aim of this article is to review the current literature on LBDS and to provide a summary of the sensitivity and specificity of each technique, and possible future applications of nanotechnologies. The LBDS showed great potential for screening and monitoring oral lesions, but there are several factors that hinder an extensive use of these devices. These devices seem to be useful in assessing lesion margins that must be biopsied. However, to date, conventional oral examination, and tissue biopsy remain the gold standard for OSCC diagnosis. The use of nanotechnologies could be the next step in the evolution of LBDS, thus providing devices that can help clinicians to detect and better monitor oral lesions.
DOI : 10.3389/fphys.2018.01510
Anahtar Kelimeler : light-based detection system, early diagnosis, chemiluminescence, autofluorescence, nanotechnology
ISSN: 1664-042X
Cilt: 9
Sınıflandırma :
23
Co-emergence and Collapse: The Mesoscopic Approach for Conceptualizing and Investigating the Functional Integration of Organisms
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Mariano Bizzarri , Alessandro Giuliani , Andrea Pensotti , Emanuele Ratti , Marta Bertolaso
Yıl :
2019
Frontiers in Physiology
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The fall of reductionist approaches to explanation leaves biology with an unescapable challenge: how to decipher complex systems. This entails a number of very critical questions, the most basic ones being: “What do we mean by ‘complex’?” and “What is the system we should look for?” In complex systems, constraints belong to a higher level that the molecular one and their effect reduces and constrains the manifold of the accessible internal states of the system itself. Function is related but not deterministically imposed by the underlying structure. It is quite unlikely that such kind of complexity could be grasped by current approaches focusing on a single organization scale. The natural co-emergence of systems, parts and properties can be adopted as a hypothesis-free conceptual framework to understand functional integration of organisms, including their hierarchical or multilevel patterns, and including the way scientific practice proceeds in approaching such complexity. External, “driving” factors – order parameters and control parameters provided by the surrounding microenvironment – are always required to “push” the components’ fate into well-defined developmental directions. In the negative, we see that in pathological processes such as cancer, organizational fluidity, collapse of levels and dynamic heterogeneity make it hard to even find a level of observation for a stable explanandum to persist in scientific practice. Parts and the system both lose their properties once the system is destabilized. The mesoscopic approach is our proposal to conceptualizing, investigating and explaining in biology. “Mesoscopic way of thinking” is increasingly popular in the epistemology of biology and corresponds to looking for an explanation (and possibly a prediction) where “non-trivial determinism is maximal”: the “most microscopic” level of organization is not necessarily the place where “the most relevant facts do happen.” A fundamental re-thinking of the concept of causality is also due for order parameters to be carefully and correctly identified. In the biological realm, entities have relational properties only, as they depend ontologically on the context they happen to be in. The basic idea of a relational ontology is that, in our inventory of the world, relations are somehow prior to the relata (i.e., entities).
DOI : 10.3389/fphys.2019.00924
Anahtar Kelimeler : living dynamics, systems thinking, mesoscopic way, data emergence, micro-environment, physical constraints
ISSN: 1664-042X
Cilt: 10
Sınıflandırma :
24
Polarization of membrane associated proteins in the choroid plexus epithelium from normal and slc4a10 knockout mice
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Inga Baasch Christensen , Tua eGyldenholm , Helle Hasager Damkier , Jeppe ePraetorius
Yıl :
2013
Frontiers in Physiology
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Kaydet Alıntıla
The choroid plexus epithelium has served as a model-epithelium for cell polarization and transport studies and plays a crucial role for cerebrospinal fluid production. The normal luminal membrane abundance of Na+,K+-ATPase, AQP1 and NHE1 in the choroid plexus is severely affected by deletion of the slc4a10 gene that encodes Ncbe/Nbcn2. The causes for these deviations from normal epithelial polarization and redistribution following specific gene knockout are unknown, but may be significant for basic epithelial cell biology. Therefore, a more comprehensible analysis of cell polarization in the choroid plexus is warranted.We find that the cytoskeleton in the choroid plexus contains αI-, αII-, βI-, and βII-spectrin isoforms along with the anchoring protein ankyrin-3, most of which are mainly localized in the luminal membrane domain. Furthermore, we find α-adducin localized near the plasma membranes globally, but with only faint expression in the luminal membrane domain. In slc4a10 knockout mice, the abundance of β1 Na+,K+-ATPase subunits in the luminal membrane is markedly reduced. AE2 abundance is increased in slc4a10 knockout and its anchor protein, α-adducin is almost exclusively found near the basolateral domain. The αI- and βI-spectrin abundances are also decreased in the slc4a10 knockout, where the basolateral domain expression of αI-spectrin is exchanged for a strictly luminal domain localization. E-cadherin expression is unchanged in the slc4a10 knockout, while small decreases in abundance are observed for its probable adaptor proteins, the catenins. Interestingly, the abundance of tight junction protein claudin-2 is significantly reduced in the slc4a10 knockouts, which may critically affect paracellular transport in this epithelium. While the observed changes do not explain the atypical polarization of the choroid plexus epithelium, they do allow generation of new hypotheses on basic cell biological paradigms that can be tested experimentally in future studi
DOI : 10.3389/fphys.2013.00344
Anahtar Kelimeler : Choroid Plexus, Cytoskeleton, sodium hydrogen exchanger, sodium bicarbonate cotransporter, epithelial polarization, cerebrospinal fluid.
ISSN: 1664-042X
Cilt: 4
Sınıflandırma :
25
Association of Cardiovascular Risk Using Nonlinear Heart Rate Variability Measures with the Framingham Risk Score in a Rural Population
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Herbert F Jelinek , Herbert F Jelinek , Hasan Md Imam , Hayder eAl-Aubaidy , Ahsan H Khandoker , Ahsan H Khandoker
Yıl :
2013
Frontiers in Physiology
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Kaydet Alıntıla
Cardiovascular risk can be calculated using the Framingham cardiovascular disease (CVD) risk score and provides a risk stratification from mild to very high CVD risk percentage over 10 years. This equation represents a complex interaction between age, gender, cholesterol status, blood pressure, diabetes status and smoking. Heart rate variability (HRV) is a measure of how the autonomic nervous system modulates the heart rate. HRV measures are sensitive to age, gender, disease status such as diabetes and hypertension and processes leading to atherosclerosis. We investigated whether HRV measures are a suitable, simple, noninvasive alternative to differentiate between the four main Framingham associated CVD risk categories. In this study we applied the tone-entropy (T-E) algorithm and complex correlation measure (CCM) for analysis of heart rate variability obtained from 20 minute ECG recordings and correlated the HRV score with the stratification results using the Framingham risk equation. Both entropy and CCM had significant analysis of variance (ANOVA) results (F172, 3 = 9.51; <0.0001). Bonferroni post hoc analysis indicated a significant difference between mild, high and very high cardiac risk groups applying tone-entropy (p<0.01). CCM detected a difference in temporal dynamics of the RR intervals between the mild and very high CVD risk groups (p<0.01). Our results indicate a good agreement between the T-E and CCM algorithm and the Framingham CVD risk score, suggesting that this algorithm may be of use for initial screening of cardiovascular risk as it is noninvasive, economical and easy to use in clinical practice.
DOI : 10.3389/fphys.2013.00186
Anahtar Kelimeler : Heart rate variability, cardiovascular risk, entropy, nonlinear, Framingham Equation, Poincare Plot
ISSN: 1664-042X
Cilt: 4
26
Integrating Heat Training in the Rehabilitation Toolbox for the Injured Athlete
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Mohammed Ihsan , Julien D. Périard , Sébastien Racinais
Yıl :
2019
Frontiers in Physiology
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Kaydet Alıntıla
DOI : 10.3389/fphys.2019.01488
Anahtar Kelimeler : heat acclimation, heat therapy, physiotherapy (rehabilitation), muscle hypertrophy, muscle atrophy, passive heating
ISSN: 1664-042X
Cilt: 10
Sınıflandırma :
27
Hormonal and Neuroendocrine Regulation of Energy Balance
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Maria eMoreno , Antonia eLanni
Yıl :
2016
Frontiers in Physiology
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Kaydet Alıntıla
DOI : 10.3389/fphys.2015.00403
Anahtar Kelimeler : Mitochondria, Thyroid Hormones, energy balance, brown adipose tissue, melanocortin, Uncoupling
ISSN: 1664-042X
Cilt: 6
Sınıflandırma :
28
Corrigendum: MicroRNA-200a/200b Modulate High Glucose-Induced Endothelial Inflammation by Targeting O-linked N-Acetylglucosamine Transferase Expression
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Wan-Yu Lo , Wan-Yu Lo , Wen-Kai Yang , Wen-Kai Yang , Ching-Tien Peng , Wan-Yu Pai , Huang-Joe Wang , Huang-Joe Wang
Yıl :
2018
Frontiers in Physiology
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Kaydet Alıntıla
DOI : 10.3389/fphys.2018.00786
Anahtar Kelimeler : diabetes, high glucose, endothelial inflammation, O-linked N-acetylglucosamine transferase, microRNA-200a/200b
ISSN: 1664-042X
Cilt: 9
Sınıflandırma :
29
Assessment of the Alveolar Capillary Network in the Postnatal Mouse Lung in 3D Using Serial Block-Face Scanning Electron Microscopy
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Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Tobias Buchacker , Tobias Buchacker , Christian Mühlfeld , Christian Mühlfeld , Christian Mühlfeld , Christoph Wrede , Christoph Wrede , Christoph Wrede , Willi L. Wagner , Willi L. Wagner , Richard Beare , Richard Beare , Matt McCormick , Roman Grothausmann , Roman Grothausmann
Yıl :
2019
Frontiers in Physiology
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Kaydet Alıntıla
The alveolar capillary network (ACN) has a large surface area that provides the basis for an optimized gas exchange in the lung. It needs to adapt to morphological changes during early lung development and alveolarization. Structural alterations of the pulmonary vasculature can lead to pathological functional conditions such as in bronchopulmonary dysplasia and various other lung diseases. To understand the development of the ACN and its impact on the pathogenesis of lung diseases, methods are needed that enable comparative analyses of the complex three-dimensional structure of the ACN at different developmental stages and under pathological conditions. In this study a newborn mouse lung was imaged with serial block-face scanning electron microscopy (SBF-SEM) to investigate the ACN and its surrounding structures before the alveolarization process begins. Most parts but not all of the examined ACN contain two layers of capillaries, which were repeatedly connected with each other. A path from an arteriole to a venule was extracted and straightened to allow cross-sectional visualization of the data along the path within a plane. This allows a qualitative characterization of the structures that erythrocytes pass on their way through the ACN. One way to define regions of the ACN supplied by specific arterioles is presented and used for analyses. Pillars, possibly intussusceptive, were found in the vasculature but no specific pattern was observed in regard to parts of the saccular septa. This study provides 3D information with a resolution of about 150 nm on the microscopic structure of a newborn mouse lung and outlines some of the potentials and challenges of SBF-SEM for 3D analyses of the ACN.
DOI : 10.3389/fphys.2019.01357
Anahtar Kelimeler : serial block-face scanning electron microscopy, capillary network, 3D reconstruction, segmentation
ISSN: 1664-042X
Cilt: 10
Sınıflandırma :
30
Disrupted Glutamate Signaling in Drosophila Generates Locomotor Rhythms in Constant Light
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Renata Van De Maas de Azevedo , Celia Hansen , Ko-Fan Chen , Ezio Rosato , Charalambos P. Kyriacou
Yıl :
2020
Frontiers in Physiology
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Kaydet Alıntıla
We have used the Cambridge Protein Trap resource (CPTI) to screen for flies whose locomotor rhythms are rhythmic in constant light (LL) as a means of identifying circadian photoreception genes. From the screen of ∼150 CPTI lines, we obtained seven hits, two of which targeted the glutamate pathway, Got1 (Glutamate oxaloacetate transaminase 1) and Gs2 (Glutamine synthetase 2). We focused on these by employing available mutants and observed that variants of these genes also showed high levels of LL rhythmicity compared with controls. It was also clear that the genetic background was important with a strong interaction observed with the common and naturally occurring timeless (tim) polymorphisms, ls-tim and s-tim. The less circadian photosensitive ls-tim allele generated high levels of LL rhythmicity in combination with Got1 or Gs2, even though ls-tim and s-tim alleles do not, by themselves, generate the LL phenotype. The use of dsRNAi for both genes as well as for Gad (Glutamic acid decarboxylase) and the metabotropic glutamate receptor DmGluRA driven by clock gene promoters also revealed high levels of LL rhythmicity compared to controls. It is clear that the glutamate pathway is heavily implicated in circadian photoreception. TIM levels in Got1 and Gs2 mutants cycled and were more abundant than in controls under LL. Got1 but not Gs2 mutants showed diminished phase shifts to 10 min light pulses. Neurogenetic dissection of the LL rhythmic phenotype using the gal4/gal80 UAS bipartite system suggested that the more dorsal CRY-negative clock neurons, DNs and LNds were responsible for the LL phenotype. Immunocytochemistry using the CPTI YFP tagged insertions for the two genes revealed that the DN1s but not the DN2 and DN3s expressed Got1 and Gs2, but expression was also observed in the lateral neurons, the LNds and s-LNvs. Expression of both genes was also found in neuroglia. However, downregulation of glial Gs2 and Got1 using repo-gal4 did not generate high levels of LL rhythmicity, so it is unlikely that this phenotype is mediated by glial expression. Our results suggest a model whereby the DN1s and possibly CRY-negative LNds use glutamate signaling to supress the pacemaker s-LNvs in LL.
DOI : 10.3389/fphys.2020.00145
Anahtar Kelimeler : Drosophila, circadian, LL rhythmicity, screen, glutamate, locomotor
ISSN: 1664-042X
Cilt: 11
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