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BIOLOGY (1420 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 1720 Journals sorted alphabetically
AAPS Journal     Hybrid Journal   (Followers: 18)
Achievements in the Life Sciences     Open Access   (Followers: 4)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 20)
Acta Biologica Colombiana     Open Access   (Followers: 6)
Acta Biologica Hungarica     Full-text available via subscription   (Followers: 4)
Acta Biologica Sibirica     Open Access  
Acta Biomaterialia     Hybrid Journal   (Followers: 25)
Acta Biotheoretica     Hybrid Journal   (Followers: 5)
Acta Chiropterologica     Full-text available via subscription   (Followers: 6)
acta ethologica     Hybrid Journal   (Followers: 4)
Acta Limnologica Brasiliensia     Open Access   (Followers: 3)
Acta Médica Costarricense     Open Access   (Followers: 2)
Acta Musei Silesiae, Scientiae Naturales : The Journal of Silesian Museum in Opava     Open Access  
Acta Parasitologica     Hybrid Journal   (Followers: 9)
Acta Scientiarum. Biological Sciences     Open Access   (Followers: 2)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
Actualidades Biológicas     Open Access   (Followers: 1)
Advanced Health Care Technologies     Open Access   (Followers: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Bioinformatics     Open Access   (Followers: 18)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4)
Advances in Biology     Open Access   (Followers: 8)
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 6)
Advances in Cell Biology     Open Access   (Followers: 23)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Ecological Research     Full-text available via subscription   (Followers: 39)
Advances in Ecology     Open Access   (Followers: 13)
Advances in Environmental Sciences - International Journal of the Bioflux Society     Open Access   (Followers: 20)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Genome Biology     Full-text available via subscription   (Followers: 12)
Advances in High Energy Physics     Open Access   (Followers: 20)
Advances in Human Biology     Open Access  
Advances in Life Science and Technology     Open Access   (Followers: 14)
Advances in Life Sciences     Open Access   (Followers: 4)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 21)
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3)
Advances in Regenerative Biology     Open Access   (Followers: 1)
Advances in Structural Biology     Full-text available via subscription   (Followers: 7)
Advances in Virus Research     Full-text available via subscription   (Followers: 5)
African Journal of Range & Forage Science     Hybrid Journal   (Followers: 6)
AFRREV STECH : An International Journal of Science and Technology     Open Access   (Followers: 1)
Ageing Research Reviews     Hybrid Journal   (Followers: 7)
Aging Cell     Open Access   (Followers: 9)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat     Open Access  
AJP Cell Physiology     Full-text available via subscription   (Followers: 13)
AJP Endocrinology and Metabolism     Full-text available via subscription   (Followers: 22)
AJP Lung Cellular and Molecular Physiology     Full-text available via subscription   (Followers: 3)
Al-Kauniyah : Jurnal Biologi     Open Access  
Alasbimn Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Biology Teacher     Full-text available via subscription   (Followers: 12)
American Fern Journal     Full-text available via subscription   (Followers: 1)
American Journal of Agricultural and Biological Sciences     Open Access   (Followers: 10)
American Journal of Bioethics     Hybrid Journal   (Followers: 10)
American Journal of Biostatistics     Open Access   (Followers: 9)
American Journal of Human Biology     Hybrid Journal   (Followers: 12)
American Journal of Medical and Biological Research     Open Access   (Followers: 5)
American Journal of Plant Sciences     Open Access   (Followers: 19)
American Journal of Primatology     Hybrid Journal   (Followers: 14)
American Malacological Bulletin     Full-text available via subscription   (Followers: 3)
American Naturalist     Full-text available via subscription   (Followers: 63)
Amphibia-Reptilia     Hybrid Journal   (Followers: 6)
Anaerobe     Hybrid Journal   (Followers: 4)
Analytical Methods     Full-text available via subscription   (Followers: 7)
Anatomical Science International     Hybrid Journal   (Followers: 2)
Animal Cells and Systems     Hybrid Journal   (Followers: 4)
Annales de Limnologie - International Journal of Limnology     Hybrid Journal   (Followers: 1)
Annales françaises d'Oto-rhino-laryngologie et de Pathologie Cervico-faciale     Full-text available via subscription   (Followers: 3)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3)
Annales UMCS, Biologia     Open Access   (Followers: 1)
Annals of Applied Biology     Hybrid Journal   (Followers: 8)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 18)
Annals of Human Biology     Hybrid Journal   (Followers: 4)
Annual Review of Biomedical Engineering     Full-text available via subscription   (Followers: 17)
Annual Review of Biophysics     Full-text available via subscription   (Followers: 25)
Annual Review of Cell and Developmental Biology     Full-text available via subscription   (Followers: 37)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 14)
Annual Review of Genomics and Human Genetics     Full-text available via subscription   (Followers: 18)
Annual Review of Phytopathology     Full-text available via subscription   (Followers: 10)
Anthropological Review     Open Access   (Followers: 23)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antibiotics     Open Access   (Followers: 8)
Antioxidants     Open Access   (Followers: 4)
Antioxidants & Redox Signaling     Hybrid Journal   (Followers: 8)
Antonie van Leeuwenhoek     Hybrid Journal   (Followers: 5)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apidologie     Hybrid Journal   (Followers: 4)
Apmis     Hybrid Journal   (Followers: 1)
APOPTOSIS     Hybrid Journal   (Followers: 8)
Applied Bionics and Biomechanics     Open Access   (Followers: 8)
Applied Vegetation Science     Full-text available via subscription   (Followers: 9)
Aquaculture Environment Interactions     Open Access   (Followers: 2)
Aquaculture International     Hybrid Journal   (Followers: 22)
Aquaculture Reports     Open Access   (Followers: 3)
Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society     Open Access   (Followers: 6)
Aquatic Biology     Open Access   (Followers: 4)
Aquatic Ecology     Hybrid Journal   (Followers: 30)
Aquatic Ecosystem Health & Management     Hybrid Journal   (Followers: 13)
Aquatic Science and Technology     Open Access   (Followers: 3)
Aquatic Toxicology     Hybrid Journal   (Followers: 19)
Archaea     Open Access   (Followers: 3)
Archiv für Molluskenkunde: International Journal of Malacology     Full-text available via subscription   (Followers: 3)
Archives of Biomedical Sciences     Open Access   (Followers: 7)
Archives of Microbiology     Hybrid Journal   (Followers: 8)
Archives of Natural History     Hybrid Journal   (Followers: 7)
Archives of Oral Biology     Hybrid Journal   (Followers: 2)
Archives of Virology     Hybrid Journal   (Followers: 5)
Archivum Immunologiae et Therapiae Experimentalis     Hybrid Journal   (Followers: 2)
Arid Ecosystems     Hybrid Journal   (Followers: 3)
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Arquivos do Museu Dinâmico Interdisciplinar     Open Access  
Arthropod Structure & Development     Hybrid Journal   (Followers: 2)
Arthropods     Open Access   (Followers: 1)
Artificial DNA: PNA & XNA     Hybrid Journal   (Followers: 2)
Artificial Photosynthesis     Open Access   (Followers: 1)
Asian Bioethics Review     Full-text available via subscription   (Followers: 1)
Asian Journal of Biodiversity     Open Access   (Followers: 5)
Asian Journal of Biological Sciences     Open Access   (Followers: 3)
Asian Journal of Cell Biology     Open Access   (Followers: 5)
Asian Journal of Developmental Biology     Open Access   (Followers: 2)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 2)
Asian Journal of Nematology     Open Access   (Followers: 3)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Australian Life Scientist     Full-text available via subscription   (Followers: 2)
Australian Mammalogy     Hybrid Journal   (Followers: 5)
Autophagy     Hybrid Journal   (Followers: 2)
Avian Biology Research     Full-text available via subscription   (Followers: 3)
Avian Conservation and Ecology     Open Access   (Followers: 7)
Bacteriology Journal     Open Access   (Followers: 2)
Bacteriophage     Full-text available via subscription   (Followers: 3)
Bangladesh Journal of Bioethics     Open Access  
Bangladesh Journal of Plant Taxonomy     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Berita Biologi     Open Access   (Followers: 1)
Between the Species     Open Access   (Followers: 1)
Bio Tribune Magazine     Hybrid Journal  
BIO Web of Conferences     Open Access  
BIO-Complexity     Open Access  
Bio-Grafía. Escritos sobre la Biología y su enseñanza     Open Access  
Bioanalytical Reviews     Hybrid Journal   (Followers: 2)
Biocatalysis and Biotransformation     Hybrid Journal   (Followers: 6)
Biochemistry and Cell Biology     Full-text available via subscription   (Followers: 14)
Biochimie     Hybrid Journal   (Followers: 7)
BioControl     Hybrid Journal   (Followers: 5)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 5)
Biodemography and Social Biology     Hybrid Journal   (Followers: 1)
Biodiversidad Colombia     Open Access  
Biodiversity : Research and Conservation     Open Access   (Followers: 26)
Biodiversity and Natural History     Open Access   (Followers: 5)
Biodiversity Data Journal     Open Access   (Followers: 3)
Biodiversity Informatics     Open Access  
Bioedukasi : Jurnal Pendidikan Biologi FKIP UM Metro     Open Access  
Bioeksperimen : Jurnal Penelitian Biologi     Open Access  
Bioelectrochemistry     Hybrid Journal   (Followers: 2)
Bioelectromagnetics     Hybrid Journal   (Followers: 1)
Bioenergy Research     Hybrid Journal   (Followers: 2)
Bioengineering and Bioscience     Open Access   (Followers: 1)
BioEssays     Hybrid Journal   (Followers: 10)
Bioethics     Hybrid Journal   (Followers: 14)
BioéthiqueOnline     Open Access  
Biofabrication     Hybrid Journal   (Followers: 3)
Biogeosciences (BG)     Open Access   (Followers: 9)
Biogeosciences Discussions (BGD)     Open Access   (Followers: 1)
Bioinformatics     Hybrid Journal   (Followers: 231)
Bioinformatics and Biology Insights     Open Access   (Followers: 14)
Bioinspiration & Biomimetics     Hybrid Journal   (Followers: 6)
Biointerphases     Open Access   (Followers: 1)
Biojournal of Science and Technology     Open Access  
Biologia     Hybrid Journal  
Biologia on-line : Revista de divulgació de la Facultat de Biologia     Open Access  
Biological Bulletin     Partially Free   (Followers: 4)
Biological Control     Hybrid Journal   (Followers: 5)
Biological Invasions     Hybrid Journal   (Followers: 16)
Biological Journal of the Linnean Society     Hybrid Journal   (Followers: 14)
Biological Letters     Open Access   (Followers: 4)
Biological Procedures Online     Open Access  
Biological Psychiatry     Hybrid Journal   (Followers: 41)
Biological Psychology     Hybrid Journal   (Followers: 6)
Biological Research     Open Access  
Biological Rhythm Research     Hybrid Journal   (Followers: 2)
Biological Theory     Hybrid Journal   (Followers: 1)
Biological Trace Element Research     Hybrid Journal  
Biologicals     Full-text available via subscription   (Followers: 9)
Biologics: Targets & Therapy     Open Access   (Followers: 1)
Biologie Aujourd'hui     Full-text available via subscription  
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 44)
Biologija     Open Access  
Biology     Open Access   (Followers: 5)
Biology and Philosophy     Hybrid Journal   (Followers: 16)
Biology Bulletin     Hybrid Journal   (Followers: 1)
Biology Bulletin Reviews     Hybrid Journal  
Biology Direct     Open Access   (Followers: 7)
Biology Letters     Full-text available via subscription   (Followers: 35)
Biology Methods and Protocols     Hybrid Journal  

        1 2 3 4 5 6 7 8 | Last

Journal Cover AJP Cell Physiology
  [SJR: 1.893]   [H-I: 151]   [13 followers]  Follow
   Full-text available via subscription Subscription journal
   ISSN (Print) 0363-6143 - ISSN (Online) 1522-1563
   Published by American Physiological Society Homepage  [13 journals]
  • Membrane lipid rafts are disturbed in the response of rat skeletal muscle
           to short-term disuse
    • Authors: Petrov, A. M; Kravtsova, V. V, Matchkov, V. V, Vasiliev, A. N, Zefirov, A. L, Chibalin, A. V, Heiny, J. A, Krivoi, I. I.
      Abstract: Marked loss of skeletal muscle mass occurs under various conditions of disuse, but the molecular and cellular mechanisms leading to atrophy are not completely understood. We investigate early molecular events that might play a role in skeletal muscle remodeling during mechanical unloading (disuse). The effects of acute (6–12 h) hindlimb suspension on the soleus muscles from adult rats were examined. The integrity of plasma membrane lipid rafts was tested utilizing cholera toxin B subunit or fluorescent sterols. In addition, resting intracellular Ca2+ level was analyzed. Acute disuse disturbed the plasma membrane lipid-ordered phase throughout the sarcolemma and was more pronounced in junctional membrane regions. Ouabain (1 µM), which specifically inhibits the Na-K-ATPase α2 isozyme in rodent skeletal muscles, produced similar lipid raft changes in control muscles but was ineffective in suspended muscles, which showed an initial loss of α2 Na-K-ATPase activity. Lipid rafts were able to recover with cholesterol supplementation, suggesting that disturbance results from cholesterol loss. Repetitive nerve stimulation also restores lipid rafts, specifically in the junctional sarcolemma region. Disuse locally lowered the resting intracellular Ca2+ concentration only near the neuromuscular junction of muscle fibers. Our results provide evidence to suggest that the ordering of lipid rafts strongly depends on motor nerve input and may involve interactions with the α2 Na-K-ATPase. Lipid raft disturbance, accompanied by intracellular Ca2+ dysregulation, is among the earliest remodeling events induced by skeletal muscle disuse.
      PubDate: 2017-05-11T03:30:22-07:00
      DOI: 10.1152/ajpcell.00365.2016
      Issue No: Vol. 312, No. 5 (2017)
  • {alpha}7{beta}1 Integrin regulation of gene transcription in skeletal
           muscle following an acute bout of eccentric exercise
    • Authors: Mahmassani, Z. S; Son, K, Pincu, Y, Munroe, M, Drnevich, J, Chen, J, Boppart, M. D.
      Abstract: The α7β1 integrin is concentrated at the costameres of skeletal muscle and provides a critical link between the actin cytoskeleton and laminin in the basement membrane. We previously demonstrated that expression of the α7BX2 integrin subunit (MCK:α7BX2) preserves muscle integrity and enhances myofiber cross-sectional area following eccentric exercise. The purpose of this study was to utilize gene expression profiling to reveal potential mechanisms by which the α7BX2-integrin contributes to improvements in muscle growth after exercise. A microarray analysis was performed using RNA extracted from skeletal muscle of wild-type or transgenic mice under sedentary conditions and 3 h following an acute bout of downhill running. Genes with false discovery rate probability values below the cutoff of P < 0.05 (n = 73) were found to be regulated by either exercise or transgene expression. KEGG pathway analysis detected upregulation of genes involved in endoplasmic reticulum protein processing with integrin overexpression. Targeted analyses verified increased transcription of Rpl13a, Nosip, Ang, Scl7a5, Gys1, Ndrg2, Hspa5, and Hsp40 as a result of integrin overexpression alone or in combination with exercise (P < 0.05). A significant increase in HSPA5 protein and a decrease in CAAT-enhancer-binding protein homologous protein (CHOP) were detected in transgenic muscle (P < 0.05). In vitro knockdown experiments verified integrin-mediated regulation of Scl7a5. The results from this study suggest that the α7β1 integrin initiates transcription of genes that allow for protection from stress, including activation of a beneficial unfolded protein response and modulation of protein synthesis, both which may contribute to positive adaptations in skeletal muscle as a result of engagement in eccentric exercise.
      PubDate: 2017-05-11T03:30:22-07:00
      DOI: 10.1152/ajpcell.00106.2016
      Issue No: Vol. 312, No. 5 (2017)
  • H2O2 augments cytosolic calcium in nucleus tractus solitarii neurons via
           multiple voltage-gated calcium channels
    • Authors: Ostrowski, T. D; Dantzler, H. A, Polo-Parada, L, Kline, D. D.
      Abstract: Reactive oxygen species (ROS) play a profound role in cardiorespiratory function under normal physiological conditions and disease states. ROS can influence neuronal activity by altering various ion channels and transporters. Within the nucleus tractus solitarii (nTS), a vital brainstem area for cardiorespiratory control, hydrogen peroxide (H2O2) induces sustained hyperexcitability following an initial depression of neuronal activity. The mechanism(s) associated with the delayed hyperexcitability are unknown. Here we evaluate the effect(s) of H2O2 on cytosolic Ca2+ (via fura-2 imaging) and voltage-dependent calcium currents in dissociated rat nTS neurons. H2O2 perfusion (200 µM; 1 min) induced a delayed, slow, and moderate increase (~27%) in intracellular Ca2+ concentration ([Ca2+]i). The H2O2-mediated increase in [Ca2+]i prevailed during thapsigargin, excluding the endoplasmic reticulum as a Ca2+ source. The effect, however, was abolished by removal of extracellular Ca2+ or the addition of cadmium to the bath solution, suggesting voltage-gated Ca2+ channels (VGCCs) as targets for H2O2 modulation. Recording of the total voltage-dependent Ca2+ current confirmed H2O2 enhanced Ca2+ entry. Blocking VGCC L, N, and P/Q subtypes decreased the number of cells and their calcium currents that respond to H2O2. The number of responder cells to H2O2 also decreased in the presence of dithiothreitol, suggesting the actions of H2O2 were dependent on sulfhydryl oxidation. In summary, here, we have shown that H2O2 increases [Ca2+]i and its Ca2+ currents, which is dependent on multiple VGCCs likely by oxidation of sulfhydryl groups. These processes presumably contribute to the previously observed delayed hyperexcitability of nTS neurons in in vitro brainstem slices.
      PubDate: 2017-05-11T03:30:22-07:00
      DOI: 10.1152/ajpcell.00195.2016
      Issue No: Vol. 312, No. 5 (2017)
  • miR-375 negatively regulates the synthesis and secretion of catecholamines
           by targeting Sp1 in rat adrenal medulla
    • Authors: Gai, Y; Zhang, J, Wei, C, Cao, W, Cui, Y, Cui, S.
      Abstract: The adrenal gland is an important endocrine gland in balancing homeostasis and the response to stress by synthesizing and secreting catecholamines (CATs), and it has been confirmed that microRNA-375 (miR-375) is highly expressed in adrenal medulla. However, up to now there are few reports about the functions and related mechanisms in adrenal medulla. The present study was thus designed to study the roles and related mechanisms in rat adrenal medulla. Our results showed that miR-375 was specifically expressed in rat adrenal medulla chromaffin cells, and its expression was downregulated when rats were exposed to stress. The further functional studies demonstrated that the inhibition of endogenous miR-375 induced the secretion of CATs in primary rat medulla chromaffin cells and PC12 cells, whereas miR-375 overexpression resulted in a decline of CAT secretion. In addition, our results showed that miR-375 negatively regulated tyrosine hydroxylase (TH) and dopamine-β-hydroxylase (DBH) and mediated adrenomedullary CAT biosynthesis. These functions of miR-375 were accomplished by its binding to the 3'-untranslated region of Sp1, which was involved in the regulation of TH and DBH expressions. These novel findings suggest that miR-375 acts as a potent negative mediator in regulating the synthesis and secretion of CATs in the adrenal medulla during the maintenance of homeostasis under stress.
      PubDate: 2017-05-11T03:30:22-07:00
      DOI: 10.1152/ajpcell.00345.2016
      Issue No: Vol. 312, No. 5 (2017)
  • The unfolded protein response in relation to mitochondrial biogenesis in
           skeletal muscle cells
    • Authors: Mesbah Moosavi, Z. S; Hood, D. A.
      Abstract: Mitochondria comprise both nuclear and mitochondrially encoded proteins requiring precise stoichiometry for their integration into functional complexes. The augmented protein synthesis associated with mitochondrial biogenesis results in the accumulation of unfolded proteins, thus triggering cellular stress. As such, the unfolded protein responses emanating from the endoplasmic reticulum (UPRER) or the mitochondrion (UPRMT) are triggered to ensure correct protein handling. Whether this response is necessary for mitochondrial adaptations is unknown. Two models of mitochondrial biogenesis were used: muscle differentiation and chronic contractile activity (CCA) in murine muscle cells. After 4 days of differentiation, our findings depict selective activation of the UPRMT in which chaperones decreased; however, Sirt3 and UPRER markers were elevated. To delineate the role of ER stress in mitochondrial adaptations, the ER stress inhibitor TUDCA was administered. Surprisingly, mitochondrial markers COX-I, COX-IV, and PGC-1α protein levels were augmented up to 1.5-fold above that of vehicle-treated cells. Similar results were obtained in myotubes undergoing CCA, in which biogenesis was enhanced by ~2–3-fold, along with elevated UPRMT markers Sirt3 and CPN10. To verify whether the findings were attributable to the terminal UPRER branch directed by the transcription factor CHOP, cells were transfected with CHOP siRNA. Basally, COX-I levels increased (~20%) and COX-IV decreased (~30%), suggesting that CHOP influences mitochondrial composition. This effect was fully restored by CCA. Therefore, our results suggest that mitochondrial biogenesis is independent of the terminal UPRER. Under basal conditions, CHOP is required for the maintenance of mitochondrial composition, but not for differentiation- or CCA-induced mitochondrial biogenesis.
      PubDate: 2017-05-03T03:30:20-07:00
      DOI: 10.1152/ajpcell.00320.2016
      Issue No: Vol. 312, No. 5 (2017)
  • Distinct physiological effects of {beta}1- and {beta}2-adrenoceptors in
           mouse ventricular myocytes: insights from a compartmentalized mathematical
    • Authors: Rozier, K; Bondarenko, V. E.
      Abstract: The β1- and β2-adrenergic signaling systems play different roles in the functioning of cardiac cells. Experimental data show that the activation of the β1-adrenergic signaling system produces significant inotropic, lusitropic, and chronotropic effects in the heart, whereas the effects of the β2-adrenergic signaling system is less apparent. In this paper, a comprehensive compartmentalized experimentally based mathematical model of the combined β1- and β2-adrenergic signaling systems in mouse ventricular myocytes is developed to simulate the experimental findings and make testable predictions of the behavior of the cardiac cells under different physiological conditions. Simulations describe the dynamics of major signaling molecules in different subcellular compartments; kinetics and magnitudes of phosphorylation of ion channels, transporters, and Ca2+ handling proteins; modifications of action potential shape and duration; and [Ca2+]i and [Na+]i dynamics upon stimulation of β1- and β2-adrenergic receptors (β1- and β2-ARs). The model reveals physiological conditions when β2-ARs do not produce significant physiological effects and when their effects can be measured experimentally. Simulations demonstrated that stimulation of β2-ARs with isoproterenol caused a marked increase in the magnitude of the L-type Ca2+ current, [Ca2+]i transient, and phosphorylation of phospholamban only upon additional application of pertussis toxin or inhibition of phosphodiesterases of type 3 and 4. The model also made testable predictions of the changes in magnitudes of [Ca2+]i and [Na+]i fluxes, the rate of decay of [Na+]i concentration upon both combined and separate stimulation of β1- and β2-ARs, and the contribution of phosphorylation of PKA targets to the changes in the action potential and [Ca2+]i transient.
      PubDate: 2017-05-03T03:30:20-07:00
      DOI: 10.1152/ajpcell.00273.2016
      Issue No: Vol. 312, No. 5 (2017)
  • Is it time to reinvent basic cell culture medium?
    • Authors: McKee, T. J; Komarova, S. V.
      PubDate: 2017-05-03T03:30:20-07:00
      DOI: 10.1152/ajpcell.00336.2016
      Issue No: Vol. 312, No. 5 (2017)
  • Vascular biology of hydrogen sulfide
    • Authors: Kanagy, N. L; Szabo, C, Papapetropoulos, A.
      Abstract: Hydrogen sulfide (H2S) is a ubiquitous signaling molecule with important functions in many mammalian organs and systems. Observations in the 1990s ascribed physiological actions to H2S in the nervous system, proposing that this gasotransmitter acts as a neuromodulator. Soon after that, the vasodilating properties of H2S were demonstrated. In the past decade, H2S was shown to exert a multitude of physiological effects in the vessel wall. H2S is produced by vascular cells and exhibits antioxidant, antiapoptotic, anti-inflammatory, and vasoactive properties. In this concise review, we have focused on the impact of H2S on vascular structure and function with an emphasis on angiogenesis, vascular tone, vascular permeability and atherosclerosis. H2S reduces arterial blood pressure, limits atheromatous plaque formation, and promotes vascularization of ischemic tissues. Although the beneficial properties of H2S are well established, mechanistic insights into the molecular pathways implicated in disease prevention and treatment remain largely unexplored. Unraveling the targets and downstream effectors of H2S in the vessel wall in the context of disease will aid in translation of preclinical observations. In addition, acute regulation of H2S production is still poorly understood and additional work delineating the pathways regulating the enzymes that produce H2S will allow pharmacological manipulation of this pathway. As the field continues to grow, we expect that H2S-related compounds will find their way into clinical trials for diseases affecting the blood vessels.
      PubDate: 2017-05-01T03:30:16-07:00
      DOI: 10.1152/ajpcell.00329.2016
      Issue No: Vol. 312, No. 5 (2017)
  • Identification of a mammalian silicon transporter
    • Authors: Ratcliffe, S; Jugdaohsingh, R, Vivancos, J, Marron, A, Deshmukh, R, Ma, J. F, Mitani-Ueno, N, Robertson, J, Wills, J, Boekschoten, M. V, Müller, M, Mawhinney, R. C, Kinrade, S. D, Isenring, P, Belanger, R. R, Powell, J. J.
      Abstract: Silicon (Si) has long been known to play a major physiological and structural role in certain organisms, including diatoms, sponges, and many higher plants, leading to the recent identification of multiple proteins responsible for Si transport in a range of algal and plant species. In mammals, despite several convincing studies suggesting that silicon is an important factor in bone development and connective tissue health, there is a critical lack of understanding about the biochemical pathways that enable Si homeostasis. Here we report the identification of a mammalian efflux Si transporter, namely Slc34a2 (also termed NaPiIIb), a known sodium-phosphate cotransporter, which was upregulated in rat kidney following chronic dietary Si deprivation. Normal rat renal epithelium demonstrated punctate expression of Slc34a2, and when the protein was heterologously expressed in Xenopus laevis oocytes, Si efflux activity (i.e., movement of Si out of cells) was induced and was quantitatively similar to that induced by the known plant Si transporter OsLsi2 in the same expression system. Interestingly, Si efflux appeared saturable over time, but it did not vary as a function of extracellular HPO42– or Na+ concentration, suggesting that Slc34a2 harbors a functionally independent transport site for Si operating in the reverse direction to the site for phosphate. Indeed, in rats with dietary Si depletion-induced upregulation of transporter expression, there was increased urinary phosphate excretion. This is the first evidence of an active Si transport protein in mammals and points towards an important role for Si in vertebrates and explains interactions between dietary phosphate and silicon.
      PubDate: 2017-05-01T03:30:16-07:00
      DOI: 10.1152/ajpcell.00219.2015
      Issue No: Vol. 312, No. 5 (2017)
  • TRPV4 ion channel is a novel regulator of dermal myofibroblast
    • Authors: Sharma, S; Goswami, R, Merth, M, Cohen, J, Lei, K. Y, Zhang, D. X, Rahaman, S. O.
      Abstract: Scleroderma is a multisystem fibroproliferative disease with no effective medical treatment. Myofibroblasts are critical to the fibrogenic tissue repair process in the skin and many internal organs. Emerging data support a role for both matrix stiffness, and transforming growth factor β1 (TGFβ1), in myofibroblast differentiation. Transient receptor potential vanilloid 4 (TRPV4) is a mechanosensitive ion channel activated by both mechanical and biochemical stimuli. The objective of this study was to determine the role of TRPV4 in TGFβ1- and matrix stiffness-induced differentiation of dermal fibroblasts. We found that TRPV4 channels are expressed and functional in both human (HDF) and mouse (MDF) dermal fibroblasts. TRPV4 activity (agonist-induced Ca2+ influx) was induced by both matrix stiffness and TGFβ1 in dermal fibroblasts. TGFβ1 induced expression of TRPV4 proteins in a dose-dependent manner. Genetic ablation or pharmacological antagonism of TRPV4 channel abrogated Ca2+ influx and both TGFβ1-induced and matrix stiffness-induced myofibroblast differentiation as assessed by 1) α-smooth muscle actin expression/incorporation into stress fibers, 2) generation of polymerized actin, and 3) expression of collagen-1. We found that TRPV4 inhibition abrogated TGFβ1-induced activation of AKT but not of Smad2/3, suggesting that the mechanism by which profibrotic TGFβ1 signaling in dermal fibroblasts is modified by TRPV4 may be through non-Smad pathways. Altogether, these data identify a novel reciprocal functional link between TRPV4 activation and TGFβ1 signals regulating dermal myofibroblast differentiation. These findings suggest that therapeutic inhibition of TRPV4 activity may provide a targeted approach to the treatment of scleroderma.
      PubDate: 2017-05-01T03:30:16-07:00
      DOI: 10.1152/ajpcell.00187.2016
      Issue No: Vol. 312, No. 5 (2017)
  • Erythropoietin facilitates definitive endodermal differentiation of mouse
           embryonic stem cells via activation of ERK signaling
    • Authors: Kaitsuka, T; Kobayashi, K, Otsuka, W, Kubo, T, Hakim, F, Wei, F.-Y, Shiraki, N, Kume, S, Tomizawa, K.
      Abstract: Artificially generated pancreatic β-cells from pluripotent stem cells are expected for cell replacement therapy for type 1 diabetes. Several strategies are adopted to direct pluripotent stem cells toward pancreatic differentiation. However, a standard differentiation method for clinical application has not been established. It is important to develop more effective and safer methods for generating pancreatic β-cells without toxic or mutagenic chemicals. In the present study, we screened several endogenous factors involved in organ development to identify the factor, which induced the efficiency of pancreatic differentiation and found that treatment with erythropoietin (EPO) facilitated the differentiation of mouse embryonic stem cells (ESCs) into definitive endoderm. At an early stage of differentiation, EPO treatment significantly increased Sox17 gene expression, as a marker of the definitive endoderm. Contrary to the canonical function of EPO, it did not affect the levels of phosphorylated JAK2 and STAT5, but stimulated the phosphorylation of ERK1/2 and Akt. The MEK inhibitor U0126 significantly inhibited EPO-induced Sox17 expression. The differentiation of ESCs into definitive endoderm is an important step for the differentiation into pancreatic and other endodermal lineages. This study suggests a possible role of EPO in embryonic endodermal development and a new agent for directing the differentiation into endodermal lineages like pancreatic β-cells.
      PubDate: 2017-05-01T03:30:16-07:00
      DOI: 10.1152/ajpcell.00071.2016
      Issue No: Vol. 312, No. 5 (2017)
School of Mathematical and Computer Sciences
Heriot-Watt University
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