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Helakari H, Järvelä M, Väyrynen T, Tuunanen J, Piispala J, Kallio M, Ebrahimi SM, Poltojainen V, Kananen J, Elabasy A, Huotari N, Raitamaa L, Tuovinen T, Korhonen V, Nedergaard M, Kiviniemi V. Effect of sleep deprivation and NREM sleep stage on physiological brain pulsations. Front Neurosci 2023; 17:1275184. [PMID: 38105924 PMCID: PMC10722275 DOI: 10.3389/fnins.2023.1275184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 11/02/2023] [Indexed: 12/19/2023] Open
Abstract
Introduction Sleep increases brain fluid transport and the power of pulsations driving the fluids. We investigated how sleep deprivation or electrophysiologically different stages of non-rapid-eye-movement (NREM) sleep affect the human brain pulsations. Methods Fast functional magnetic resonance imaging (fMRI) was performed in healthy subjects (n = 23) with synchronous electroencephalography (EEG), that was used to verify arousal states (awake, N1 and N2 sleep). Cardiorespiratory rates were verified with physiological monitoring. Spectral power analysis assessed the strength, and spectral entropy assessed the stability of the pulsations. Results In N1 sleep, the power of vasomotor (VLF < 0.1 Hz), but not cardiorespiratory pulsations, intensified after sleep deprived vs. non-sleep deprived subjects. The power of all three pulsations increased as a function of arousal state (N2 > N1 > awake) encompassing brain tissue in both sleep stages, but extra-axial CSF spaces only in N2 sleep. Spectral entropy of full band and respiratory pulsations decreased most in N2 sleep stage, while cardiac spectral entropy increased in ventricles. Discussion In summary, the sleep deprivation and sleep depth, both increase the power and harmonize the spectral content of human brain pulsations.
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Affiliation(s)
- Heta Helakari
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Matti Järvelä
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Tommi Väyrynen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Johanna Tuunanen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Johanna Piispala
- Clinical Neurophysiology, Oulu University Hospital, Oulu, Finland
| | - Mika Kallio
- Clinical Neurophysiology, Oulu University Hospital, Oulu, Finland
| | - Seyed Mohsen Ebrahimi
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Valter Poltojainen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Janne Kananen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
- Clinical Neurophysiology, Oulu University Hospital, Oulu, Finland
| | - Ahmed Elabasy
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Niko Huotari
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Lauri Raitamaa
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Timo Tuovinen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Vesa Korhonen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Maiken Nedergaard
- Center of Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
- Center of Translational Neuromedicine, University of Rochester, Rochester, NY, United States
| | - Vesa Kiviniemi
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
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Varricchio A, Yool AJ. Aquaporins and Ion Channels as Dual Targets in the Design of Novel Glioblastoma Therapeutics to Limit Invasiveness. Cancers (Basel) 2023; 15. [PMID: 36765806 DOI: 10.3390/cancers15030849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/20/2023] [Accepted: 01/28/2023] [Indexed: 01/31/2023] Open
Abstract
Current therapies for Glioblastoma multiforme (GBM) focus on eradicating primary tumors using radiotherapy, chemotherapy and surgical resection, but have limited success in controlling the invasive spread of glioma cells into a healthy brain, the major factor driving short survival times for patients post-diagnosis. Transcriptomic analyses of GBM biopsies reveal clusters of membrane signaling proteins that in combination serve as robust prognostic indicators, including aquaporins and ion channels, which are upregulated in GBM and implicated in enhanced glioblastoma motility. Accumulating evidence supports our proposal that the concurrent pharmacological targeting of selected subclasses of aquaporins and ion channels could impede glioblastoma invasiveness by impairing key cellular motility pathways. Optimal sets of channels to be selected as targets for combined therapies could be tailored to the GBM cancer subtype, taking advantage of differences in patterns of expression between channels that are characteristic of GBM subtypes, as well as distinguishing them from non-cancerous brain cells such as neurons and glia. Focusing agents on a unique channel fingerprint in GBM would further allow combined agents to be administered at near threshold doses, potentially reducing off-target toxicity. Adjunct therapies which confine GBM tumors to their primary sites during clinical treatments would offer profound advantages for treatment efficacy.
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Soden PA, Henderson AR, Lee E. A Microfluidic Model of AQP4 Polarization Dynamics and Fluid Transport in the Healthy and Inflamed Human Brain: The First Step Towards Glymphatics-on-a-Chip. Adv Biol (Weinh) 2022; 6:e2200027. [PMID: 35922370 PMCID: PMC9771879 DOI: 10.1002/adbi.202200027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 07/01/2022] [Indexed: 01/28/2023]
Abstract
Dysfunction of the aquaporin-4 (AQP4)-dependent glymphatic waste clearance pathway has recently been implicated in the pathogenesis of several neurodegenerative diseases. However, it is difficult to unravel the causative relationship between glymphatic dysfunction, AQP4 depolarization, protein aggregation, and inflammation in neurodegeneration using animal models alone. There is currently a clear, unmet need for in vitro models of the brain's waterscape, and the first steps towards a bona fide "glymphatics-on-a-chip" are taken in the present study. It is demonstrated that chronic exposure to lipopolysaccharide (LPS), amyloid-β(1-42) oligomers, and an AQP4 inhibitor impairs the drainage of fluid and amyloid-β(1-40) tracer in a gliovascular unit (GVU)-on-a-chip model containing human astrocytes and brain microvascular endothelial cells. The LPS-induced drainage impairment is partially retained following cell lysis, indicating that neuroinflammation induces parallel changes in cell-dependent and matrisome-dependent fluid transport pathways in GVU-on-a-chip. Additionally, AQP4 depolarization is observed following LPS treatment, suggesting that LPS-induced drainage impairments on-chip may be driven in part by changes in AQP4-dependent fluid dynamics.
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Affiliation(s)
- Paul A Soden
- College of Human Ecology, Cornell University, Ithaca, NY, 14853, USA
| | - Aria R Henderson
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Esak Lee
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA
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Lens F, Gleason SM, Bortolami G, Brodersen C, Delzon S, Jansen S. Functional xylem characteristics associated with drought-induced embolism in angiosperms. New Phytol 2022; 236:2019-2036. [PMID: 36039697 DOI: 10.1111/nph.18447] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 08/03/2022] [Indexed: 06/15/2023]
Abstract
Hydraulic failure resulting from drought-induced embolism in the xylem of plants is a key determinant of reduced productivity and mortality. Methods to assess this vulnerability are difficult to achieve at scale, leading to alternative metrics and correlations with more easily measured traits. These efforts have led to the longstanding and pervasive assumed mechanistic link between vessel diameter and vulnerability in angiosperms. However, there are at least two problems with this assumption that requires critical re-evaluation: (1) our current understanding of drought-induced embolism does not provide a mechanistic explanation why increased vessel width should lead to greater vulnerability, and (2) the most recent advancements in nanoscale embolism processes suggest that vessel diameter is not a direct driver. Here, we review data from physiological and comparative wood anatomy studies, highlighting the potential anatomical and physicochemical drivers of embolism formation and spread. We then put forward key knowledge gaps, emphasising what is known, unknown and speculation. A meaningful evaluation of the diameter-vulnerability link will require a better mechanistic understanding of the biophysical processes at the nanoscale level that determine embolism formation and spread, which will in turn lead to more accurate predictions of how water transport in plants is affected by drought.
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Affiliation(s)
- Frederic Lens
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA, Leiden, the Netherlands
- Leiden University, Institute of Biology Leiden, Plant Sciences, Sylviusweg 72, 2333 BE, Leiden, the Netherlands
| | - Sean M Gleason
- Water Management and Systems Research Unit, United States Department of Agriculture, Agricultural Research Service, Fort Collins, CO, 80526, USA
| | - Giovanni Bortolami
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA, Leiden, the Netherlands
| | - Craig Brodersen
- School of the Environment, Yale University, New Haven, CT, 06511, USA
| | - Sylvain Delzon
- University of Bordeaux, INRAE, BIOGECO, 33615, Pessac, France
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, D-89081, Ulm, Germany
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5
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Quade BN, Marshall A, Parker MD. Corneal dystrophy mutations R125H and R804H disable SLC4A11 by altering the extracellular pH dependence of the intracellular pK that governs H +(OH -) transport. Am J Physiol Cell Physiol 2022; 323:C990-C1002. [PMID: 35993514 PMCID: PMC9484998 DOI: 10.1152/ajpcell.00221.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 08/11/2022] [Accepted: 08/11/2022] [Indexed: 11/22/2022]
Abstract
Mutations in the H+(OH-) conductor SLC4A11 result in corneal endothelial dystrophy. In previous studies using mouse Slc4a11, we showed that the pK value that governs the intracellular pH dependence of SLC4A11 (pKi) is influenced by extracellular pH (pHe). We also showed that some mutations result in acidic or alkaline shifts in pKi, indicating that the pH dependence of SLC4A11 is important for physiological function. An R125H mutant, located in the cytosolic amino terminus of SLC4A11, apparently causes a complete loss of function, yet the anion transport inhibitor 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) can partially rescue SLC4A11/R125H activity. In the present study we set out to determine whether the effect of R125H is explained by an extreme shift in pKi. In Xenopus oocytes, we measured SLC4A11-mediated H+(OH-) conductance while monitoring pHi. We find that 1) the human corneal variant SLC4A11-B has a more acidic pKi than mouse Slc4a11, likely due to the presence of an NH2-terminal appendage; 2) pKi for human SLC4A11 is acid-shifted by raising pHe to 10.00; and 3) R125H and R804H mutants mediate substantial H+(OH-) conductances at pHe = 10.00, with pKi shifted into the wild-type range. These data suggest that the defect in each is a shift in pKi at physiological pHe, brought about by a disconnection in the mechanisms by which pHe influences pKi. Using de novo modeling, we show that R125 is located at the cytosolic dimer interface and suggest that this interface is critical for relaying the influence of pHe on the external face of the transmembrane domain to the intracellular, pKi-determining regions.
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Affiliation(s)
- Bianca N Quade
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, New York
| | - Aniko Marshall
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, New York
| | - Mark D Parker
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, New York
- Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, New York
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Salman MM, Kitchen P, Yool AJ, Bill RM. Recent breakthroughs and future directions in drugging aquaporins. Trends Pharmacol Sci 2021; 43:30-42. [PMID: 34863533 DOI: 10.1016/j.tips.2021.10.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/09/2021] [Accepted: 10/18/2021] [Indexed: 02/06/2023]
Abstract
Aquaporins facilitate the passive transport of water, solutes, or ions across biological membranes. They are implicated in diverse pathologies including brain edema following stroke or trauma, epilepsy, cancer cell migration and tumor angiogenesis, metabolic disorders, and inflammation. Despite this, there is no aquaporin-targeted drug in the clinic and aquaporins have been perceived to be intrinsically non-druggable targets. Here we challenge this idea, as viable routes to inhibition of aquaporin function have recently been identified, including targeting their regulation or their roles as channels for unexpected substrates. Identifying new drug development frameworks for conditions associated with disrupted water and solute homeostasis will meet the urgent, unmet clinical need of millions of patients for whom no pharmacological interventions are available.
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Affiliation(s)
- Mootaz M Salman
- Department of Physiology, Anatomy and Genetics, Kavli Institute for NanoScience Discovery, University of Oxford, Oxford OX1 3PT, UK; Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK.
| | - Philip Kitchen
- School of Biosciences, College of Health and Life Sciences, Aston University, Birmingham B4 7ET, UK.
| | - Andrea J Yool
- University of Adelaide, School of Biomedicine, Adelaide, South Australia 5005, Australia.
| | - Roslyn M Bill
- School of Biosciences, College of Health and Life Sciences, Aston University, Birmingham B4 7ET, UK.
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Guidoboni G, Marazzi NM, Fraser J, Sacco R, Palaniappan K, Huxley VH. Fluid and protein exchange in microvascular networks: Importance of modelling heterogeneity in geometrical and biophysical properties. J Physiol 2021; 599:4597-4624. [PMID: 34387386 PMCID: PMC8526410 DOI: 10.1113/jp281841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/03/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Microvascular network architecture defines coupling of fluid and protein exchange. Network arrangements markedly reduce capillary hydrostatic pressures and resting fluid movement at the same time as increasing the capacity for change The presence of vascular remodelling or angiogenesis puts constraints of network behaviour The sites of fluid and protein exchange can be segregated to different portions of the network Although there is a net filtration of fluid from a network of exchange vessels, there are specific areas where fluid moves into the circulation (reabsorption) and, when protein is moving into tissue, the amount is insufficient under basal conditions to result in changes in oncotic pressure. ABSTRACT Integration of functional results obtained across scales, from chemical signalling to the whole organism, is a daunting task requiring the marriage of experimental data with mathematical modelling. In the present study, a novel coupled computational fluid dynamics model is developed incorporating fluid and protein transport using measurements in an in vivo frog (Rana pipiens) mesenteric microvascular network. The influences of network architecture and exchange are explored systematically under the common assumptions of structurally and functionally identical microvessels (Homogeneous Scenario) or microvessels classified by position in flow (Class Uniform Scenario), which are compared with realistic microvascular network components (Heterogeneous Scenario). The model incorporates ten quantities that vary within a microvessel; pressure boundary conditions are calibrated against experimental measurements. The Homogeneous Scenario standard model showed that assuming a single 'typical' capillary hides the influence of vessels arranged into a network architecture, where capillary hydrostatic pressures (pT ) are reduced, resulting in both a nonuniform distribution of blood flow and reduced volume flow rate (Jf,T ). In the Class Uniform Scenario pT was further attenuated to produce a ∼60% reduction in Jf,T . Finally, the Heterogeneous Scenario, incorporating measures of individual vessel surface area, demonstrates additional lowering of pT from inlet values favouring a >70% reduction of Jf,T in the face of a ∼120% increase in protein movement into the tissues relative to the Homogeneous Scenario. Beyond the impacts of network architecture, an unanticipated finding was the influence of a blind-end microvessel on model convergence, indicating a profound influence of the largely unexplored dynamics of vascular remodelling on tissue perfusion.
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Affiliation(s)
- Giovanna Guidoboni
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, USA
- Department of Mathematics, University of Missouri, Columbia, MO, USA
- Center for Gender Physiology, University of Missouri, Columbia, MO, USA
| | - Nicholas M. Marazzi
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, USA
- Center for Gender Physiology, University of Missouri, Columbia, MO, USA
| | - Joshua Fraser
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, USA
| | - Riccardo Sacco
- Department of Mathematics, Politecnico di Milano, Milano, Italy
- Center for Gender Physiology, University of Missouri, Columbia, MO, USA
| | - Kannappan Palaniappan
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, USA
- Center for Gender Physiology, University of Missouri, Columbia, MO, USA
| | - Virginia H. Huxley
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
- Center for Gender Physiology, University of Missouri, Columbia, MO, USA
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Sheng Z, Zhang M, Liu J, Malgaretti P, Li J, Wang S, Lv W, Zhang R, Fan Y, Zhang Y, Chen X, Hou X. Reconfiguring confined magnetic colloids with tunable fluid transport behavior. Natl Sci Rev 2021; 8:nwaa301. [PMID: 34691643 PMCID: PMC8352900 DOI: 10.1093/nsr/nwaa301] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/01/2020] [Accepted: 12/07/2020] [Indexed: 12/19/2022] Open
Abstract
Collective dynamics of confined colloids are crucial in diverse scenarios such as self-assembly and phase behavior in materials science, microrobot swarms for drug delivery and microfluidic control. Yet, fine-tuning the dynamics of colloids in microscale confined spaces is still a formidable task due to the complexity of the dynamics of colloidal suspension and to the lack of methodology to probe colloids in confinement. Here, we show that the collective dynamics of confined magnetic colloids can be finely tuned by external magnetic fields. In particular, the mechanical properties of the confined colloidal suspension can be probed in real time and this strategy can be also used to tune microscale fluid transport. Our experimental and theoretical investigations reveal that the collective configuration characterized by the colloidal entropy is controlled by the colloidal concentration, confining ratio and external field strength and direction. Indeed, our results show that mechanical properties of the colloidal suspension as well as the transport of the solvent in microfluidic devices can be controlled upon tuning the entropy of the colloidal suspension. Our approach opens new avenues for the design and application of drug delivery, microfluidic logic, dynamic fluid control, chemical reaction and beyond.
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Affiliation(s)
- Zhizhi Sheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
- Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen 361005, China
| | - Mengchuang Zhang
- Department of Physics, Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Laboratory for Soft Functional Materials Research, Jiujiang Research Institute, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
| | - Jing Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Paolo Malgaretti
- Max Planck Institute for Intelligent Systems, Stuttgart 70569, Germany
- IV Institute for Theoretical Physics, University of Stuttgart, Stuttgart 70049, Germany
| | - Jianyu Li
- Department of Mechanical Engineering, McGill University, Montreal H3A 0G4, Canada
- Department of Biomedical Engineering, McGill University, Montreal H3A 0G4, Canada
| | - Shuli Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
- Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen 361005, China
| | - Wei Lv
- Department of Physics, Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Laboratory for Soft Functional Materials Research, Jiujiang Research Institute, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
| | - Rongrong Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Yi Fan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Yunmao Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xinyu Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xu Hou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
- Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen 361005, China
- Department of Physics, Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Laboratory for Soft Functional Materials Research, Jiujiang Research Institute, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
- Tan Kah KeeInnovation Laboratory, Xiamen 361102, China
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Weidenfeld S, Chupin C, Langner DI, Zetoun T, Rozowsky S, Kuebler WM. Sodium-coupled neutral amino acid transporter SNAT2 counteracts cardiogenic pulmonary edema by driving alveolar fluid clearance. Am J Physiol Lung Cell Mol Physiol 2021; 320:L486-L497. [PMID: 33439101 DOI: 10.1152/ajplung.00461.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The constant transport of ions across the alveolar epithelial barrier regulates alveolar fluid homeostasis. Dysregulation or inhibition of Na+ transport causes fluid accumulation in the distal airspaces resulting in impaired gas exchange and respiratory failure. Previous studies have primarily focused on the critical role of amiloride-sensitive epithelial sodium channel (ENaC) in alveolar fluid clearance (AFC), yet activation of ENaC failed to attenuate pulmonary edema in clinical trials. Since 40% of AFC is amiloride-insensitive, Na+ channels/transporters other than ENaC such as Na+-coupled neutral amino acid transporters (SNATs) may provide novel therapeutic targets. Here, we identified a key role for SNAT2 (SLC38A2) in AFC and pulmonary edema resolution. In isolated perfused mouse and rat lungs, pharmacological inhibition of SNATs by HgCl2 and α-methylaminoisobutyric acid (MeAIB) impaired AFC. Quantitative RT-PCR identified SNAT2 as the highest expressed System A transporter in pulmonary epithelial cells. Pharmacological inhibition or siRNA-mediated knockdown of SNAT2 reduced transport of l-alanine across pulmonary epithelial cells. Homozygous Slc38a2-/- mice were subviable and died shortly after birth with severe cyanosis. Isolated lungs of Slc38a2+/- mice developed higher wet-to-dry weight ratios (W/D) as compared to wild type (WT) in response to hydrostatic stress. Similarly, W/D ratios were increased in Slc38a2+/- mice as compared to controls in an acid-induced lung injury model. Our results identify SNAT2 as a functional transporter for Na+ and neutral amino acids in pulmonary epithelial cells with a relevant role in AFC and the resolution of lung edema. Activation of SNAT2 may provide a new therapeutic strategy to counteract and/or reverse pulmonary edema.
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Affiliation(s)
- Sarah Weidenfeld
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Cécile Chupin
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
| | | | - Tamador Zetoun
- Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Simon Rozowsky
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Wolfgang M Kuebler
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
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10
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Affiliation(s)
- Francisco J Alvarez-Leefmans
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
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11
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Quade BN, Marshall A, Parker MD. pH dependence of the Slc4a11-mediated H + conductance is influenced by intracellular lysine residues and modified by disease-linked mutations. Am J Physiol Cell Physiol 2020; 319:C359-C370. [PMID: 32520610 DOI: 10.1152/ajpcell.00128.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
SLC4A11 is the only member of the SLC4 family that transports protons rather than bicarbonate. SLC4A11 is expressed in corneal endothelial cells, and its mutation causes corneal endothelial dystrophy, although the mechanism of pathogenesis is unknown. We previously demonstrated that the magnitude of the H+ conductance (Gm) mediated by SLC4A11 is increased by rises in intracellular as well as extracellular pH (pHi and pHe). To better understand this feature and whether it is altered in disease, we studied the pH dependence of wild-type and mutant mouse Slc4a11 expressed in Xenopus oocytes. Using voltage-clamp circuitry in conjunction with a H+-selective microelectrode and a microinjector loaded with NaHCO3, we caused incremental rises in oocyte pHi and measured the effect on Gm. We find that the rise of Gm has a steeper pHi dependence at pHe =8.50 than at pHe =7.50. Data gathered at pHe =8.50 can be fit to the Hill equation enabling the calculation of a pK value that reports pHi dependence. We find that mutation of lysine residues that are close to the first transmembrane span (TM1) causes an alkaline shift in pK. Furthermore, two corneal-dystrophy-causing mutations close to the extracellular end of TM1, E399K and T401K (E368K and T370K in mouse), cause an acidic shift in pK, while a third mutation in the fourth intracellular loop, R804H (R774H in mouse), causes an alkaline shift in pK. This is the first description of determinants of SLC4A11 pH dependence and the first indication that a shift in pH dependence could modify disease expressivity in some cases of corneal dystrophy.
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Affiliation(s)
- Bianca N Quade
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, New York
| | - Aniko Marshall
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, New York
| | - Mark D Parker
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, New York.,Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo: The State University of New York, Buffalo, New York.,State University of New York Eye Institute, University at Buffalo: The State University of New York, Buffalo, New York
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12
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Liu W, Ni H, Wang P, Zhou Y. An investigation on the drag reduction performance of bioinspired pipeline surfaces with transverse microgrooves. Beilstein J Nanotechnol 2020; 11:24-40. [PMID: 31976194 PMCID: PMC6964665 DOI: 10.3762/bjnano.11.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 12/11/2019] [Indexed: 06/10/2023]
Abstract
A novel surface morphology for pipelines using transverse microgrooves was proposed in order to reduce the pressure loss of fluid transport. Numerical simulation and experimental research efforts were undertaken to evaluate the drag reduction performance of these bionic pipelines. It was found that the vortex 'cushioning' and 'driving' effects produced by the vortexes in the microgrooves were the main reason for obtaining a drag reduction effect. The shear stress of the microgrooved surface was reduced significantly owing to the decline of the velocity gradient. Altogether, bionic pipelines achieved drag reduction effects both in a pipeline and in a concentric annulus flow model. The primary and secondary order of effect on the drag reduction and optimal microgroove geometric parameters were obtained by an orthogonal analysis method. The comparative experiments were conducted in a water tunnel, and a maximum drag reduction rate of 3.21% could be achieved. The numerical simulation and experimental results were cross-checked and found to be consistent with each other, allowing to verify that the utilization of bionic theory to reduce the pressure loss of fluid transport is feasible. These results can provide theoretical guidance to save energy in pipeline transportations.
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Affiliation(s)
- Weili Liu
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China
- Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao 266580, China
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary T2N1N4, Canada
| | - Hongjian Ni
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China
- Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao 266580, China
| | - Peng Wang
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China
- Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao 266580, China
| | - Yi Zhou
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China
- Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao 266580, China
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Abstract
Microfluidics is a continuously growing field with potential not only in the fields of medical, chemical, and bioanalysis, but also in the domains of optics and information technology. Here, a pressure-driven 3D microfluidic chip is demonstrated with multiple logic Boolean functions. The presence and absence of fluid at the output of the gates represent the binary signals 1 and 0, respectively. Therefore, the logic gates do not require a specially functionalized liquid to operate. The chip is based on a multilevel of poly(methyl methacrylate) (PMMA)-based polymeric sheets with aligned microchannels while a flexible polyimide-based sheet with a cantilever-like structure is embedded to enable a one-directional flow of the liquid. Several Boolean logic functions are realized (AND, OR, and XOR) using different fluids in addition to a half adder digital microfluidic circuit. The outputs of the logic gates are designed to be at different heights within the 3D chip to enable different pressure drops. The results show that the logic gates are operational for a specific range of flow rates, which is dependent on the microchannel dimensions, surface roughness, and fluid viscosity and therefore on their hydraulic resistance. The demonstrated approach enables simple cascading of logic gates for large-scale microfluidic computing systems.
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Affiliation(s)
- Nazek El‐Atab
- mmh LabsElectrical EngineeringComputer Electrical Mathematical Science and Engineering DivisionKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Javier Chavarrio Canas
- mmh LabsElectrical EngineeringComputer Electrical Mathematical Science and Engineering DivisionKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Muhammad M. Hussain
- mmh LabsElectrical EngineeringComputer Electrical Mathematical Science and Engineering DivisionKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
- Electrical Engineering and Computer ScienceUniversity of CaliforniaBerkeleyCA94720‐1770USA
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14
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Abstract
Cilia are specialized cellular organelles that are united in structure and implicated in diverse key life processes across eukaryotes. In both unicellular and multicellular organisms, variations on the same ancestral form mediate sensing, locomotion and the production of physiological flows. As we usher in a new, more interdisciplinary era, the way we study cilia is changing. This special theme issue brings together biologists, biophysicists and mathematicians to highlight the remarkable range of systems in which motile cilia fulfil vital functions, and to inspire and define novel strategies for future research. This article is part of the Theo Murphy meeting issue 'Unity and diversity of cilia in locomotion and transport'.
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Affiliation(s)
- Kirsty Y Wan
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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15
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Wu S, Yang H, Xiong G, Tian Y, Gong B, Luo T, Fisher TS, Yan J, Cen K, Bo Z, Ostrikov KK. Spill-SOS: Self-Pumping Siphon-Capillary Oil Recovery. ACS Nano 2019; 13:13027-13036. [PMID: 31660731 DOI: 10.1021/acsnano.9b05703] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Oil spills remain a worldwide challenge and need emergency "spill-SOS" actions when they occur. Conventional methods suffer from complex processes and high cost. Here, we demonstrate a solar-heating siphon-capillary oil skimmer (S-SOS) that harvests solar energy, gravitational potential energy, and solid surface energy to enable efficient oil spill recovery in a self-pumping manner. The S-SOS is assembled by an inverted U-shape porous architecture combining solar-heating, siphon, and capillary effects, and works without any external power or manual interventions. Importantly, solid surface energy is used by capillary adsorption to enable the self-starting behavior, gravitational potential energy is utilized by siphon transport to drive the oil flow, and solar energy is harvested by solar-thermal conversion to facilitate the transport speed. In the proof-of-concept work, an all-carbon hierarchical architecture (VG/GF) is fabricated by growing vertically oriented graphene nanosheets (VGs) on a monolith of graphite felt (GF) via a plasma-enhanced method to serve as the U-shape architecture. Consequently, an oil-recovery rate of 35.2 L m-2 h-1 is obtained at ambient condition. When exposed to normal solar irradiation, the oil-recovery rate dramatically increases to 123.3 L m-2 h-1. Meanwhile, the solar-thermal energy efficiency is calculated to be 75.3%. Moreover, the S-SOS system presents excellent stability without obvious performance-degradation over 60 h. The outstanding performance is ascribed to the enhanced siphon action, capillary action, photonic absorption, and interfacial heating in the plasma-made graphene nanostructures. Multiple merits make the current S-SOS design and the VG/GF nanostructures promising for efficient oil recovery and transport of energy stored in chemical bonds.
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Affiliation(s)
- Shenghao Wu
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering , Zhejiang University , Hangzhou , Zhejiang 310027 , China
| | - Huachao Yang
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering , Zhejiang University , Hangzhou , Zhejiang 310027 , China
| | - Guoping Xiong
- Department of Mechanical Engineering , University of Nevada , Reno , Nevada 89557 , United States
| | - Yikuan Tian
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering , Zhejiang University , Hangzhou , Zhejiang 310027 , China
| | - Biyao Gong
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering , Zhejiang University , Hangzhou , Zhejiang 310027 , China
| | - Tengfei Luo
- Department of Aerospace and Mechanical Engineering , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| | - Timothy S Fisher
- Department of Mechanical & Aerospace Engineering and California nanoSystems Institute , University of California , Los Angeles , California 90095 , United States
| | - Jianhua Yan
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering , Zhejiang University , Hangzhou , Zhejiang 310027 , China
| | - Kefa Cen
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering , Zhejiang University , Hangzhou , Zhejiang 310027 , China
| | - Zheng Bo
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering , Zhejiang University , Hangzhou , Zhejiang 310027 , China
| | - Kostya Ken Ostrikov
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering , Zhejiang University , Hangzhou , Zhejiang 310027 , China
- School of Chemistry, Physics and Mechanical Engineering , Queensland University of Technology , Brisbane , Queensland 4000 , Australia
- Joint CSIRO-QUT Sustainable Processes and Devices Laboratory , P.O. Box 218, Lindfield , New South Wales 2070 , Australia
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16
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Gorb SN, Koch K, Heepe L. Biological and biomimetic surfaces: adhesion, friction and wetting phenomena. Beilstein J Nanotechnol 2019; 10:481-482. [PMID: 30873319 PMCID: PMC6404513 DOI: 10.3762/bjnano.10.48] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 01/25/2019] [Indexed: 05/04/2023]
Affiliation(s)
- Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute of the University of Kiel, Am Botanischen Garten 9, 24118 Kiel, Germany
| | - Kerstin Koch
- Rhine-Waal-University of Applied Sciences, Marie Currie Str. 1, 47533 Kleve, Germany
| | - Lars Heepe
- Department of Functional Morphology and Biomechanics, Zoological Institute of the University of Kiel, Am Botanischen Garten 9, 24118 Kiel, Germany
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17
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Krediet RT. Ultrafiltration Failure Is a Reflection of Peritoneal Alterations in Patients Treated With Peritoneal Dialysis. Front Physiol 2018; 9:1815. [PMID: 30618825 PMCID: PMC6306483 DOI: 10.3389/fphys.2018.01815] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/05/2018] [Indexed: 11/13/2022] Open
Abstract
Ultrafiltration (UF) failure is a common and important complication of peritoneal dialysis (PD), especially in long-term patients without residual urine production, because it often causes overhydration, which is an important cause of death in this population. The current review provides an overview of the pathways of peritoneal fluid transport, followed by the mechanisms and causes of UF failure. The egression of circulating fluid to the tissue compartment and its subsequent re-uptake by the colloid osmotic pressure are markedly influenced by PD, because the dialysis solutions contain glucose as a low molecular weight agent causing removal of fluid from the circulation by crystalloid osmosis. Pores involved in transcapillary UF consist of inter-endothelial small pores and the intra-endothelial water channel aquaporin-1. The former allows transport of plasma fluid with dissolved low molecular weight solutes and accounts for 60% of the filtered volume, the latter transports 40% as pure water. This free water transport (FWT) is driven by the crystalloid pressure gradient, while small pore fluid transport (SPFT) is dependent on both hydrostatic and crystalloid osmotic pressure. The number of perfused peritoneal microvessels as assessed by small solute transport parameters, is differently associated with UF: a positive relationship is present with SPFT, but a negative one with FWT, because the effect of more vessels is counteracted by a faster disappearance rate of glucose. Ultrafiltration failure can be present shortly after the start of PD, for instance due to mesothelial-to-mesenchymal transition. Late UF failure develops in 21% of long-term patients. Both FWT and SPFT can be affected. Patients with encapsulating peritoneal sclerosis have severely impaired FWT, probably due to interference of interstitial collagen-1 with the crystalloid osmotic gradient. This mechanism may also apply to other patients with reduced FWT. Those with mainly impaired SPFT likely have a reduced hydrostatic filtration pressure due to vasculopathy. Deposition of advanced glycosylation end products is probably important in the development of this vasculopathy. It can be concluded that long-term UF failure may affect both SPFT and FWT. Vasculopathy is important in the former, interstitial fibrosis in the latter. Measurements of peritoneal transport function should include separate assessments of small pore-and FWT.
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Affiliation(s)
- Raymond T Krediet
- Division of Nephrology, Department of Medicine, Amsterdam UMC, Amsterdam, Netherlands
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18
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Berthonneau J, Obliger A, Valdenaire PL, Grauby O, Ferry D, Chaudanson D, Levitz P, Kim JJ, Ulm FJ, Pellenq RJ. Mesoscale structure, mechanics, and transport properties of source rocks' organic pore networks. Proc Natl Acad Sci U S A 2018; 115:12365-70. [PMID: 30442660 DOI: 10.1073/pnas.1808402115] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In source rocks, natural hydrocarbons are generated from organic matter dispersed in a fine-grained mineral matrix. The potential recovery of hydrocarbons is therefore influenced by the geometry of the organic hosted porous networks. Here, the three-dimensional structures of such networks are revealed using electron tomography with a subnanometer resolution. The reconstructions are first characterized in terms of morphology and topology and then used to build a multiscale simulation tool to study the mechanics and the transport properties of confined fluids. Our results offer evidence of the prevalent role of connected nanopores, which subsequently constitutes a material limit for long-term hydrocarbon production. Organic matter is responsible for the generation of hydrocarbons during the thermal maturation of source rock formation. This geochemical process engenders a network of organic hosted pores that governs the flow of hydrocarbons from the organic matter to fractures created during the stimulation of production wells. Therefore, it can be reasonably assumed that predictions of potentially recoverable confined hydrocarbons depend on the geometry of this pore network. Here, we analyze mesoscale structures of three organic porous networks at different thermal maturities. We use electron tomography with subnanometric resolution to characterize their morphology and topology. Our 3D reconstructions confirm the formation of nanopores and reveal increasingly tortuous and connected pore networks in the process of thermal maturation. We then turn the binarized reconstructions into lattice models including information from atomistic simulations to derive mechanical and confined fluid transport properties. Specifically, we highlight the influence of adsorbed fluids on the elastic response. The resulting elastic energy concentrations are localized at the vicinity of macropores at low maturity whereas these concentrations present more homogeneous distributions at higher thermal maturities, due to pores’ topology. The lattice models finally allow us to capture the effect of sorption on diffusion mechanisms with a sole input of network geometry. Eventually, we corroborate the dominant impact of diffusion occurring within the connected nanopores, which constitute the limiting factor of confined hydrocarbon transport in source rocks.
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19
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Abstract
The exact mechanism to orchestrate the action of hundreds of dynein motor proteins to generate wave-like ciliary beating remains puzzling and has fascinated many scientists. We present a 3D model of a cilium and the simulation of its beating in a fluid environment. The model cilium obeys a simple geometric constraint that arises naturally from the microscopic structure of a real cilium. This constraint allows us to determine the whole 3D structure at any instant in terms of the configuration of a single space curve. The tensions of active links, which model the dynein motor proteins, follow a postulated dynamical law, and together with the passive elasticity of microtubules, this dynamical law is responsible for the ciliary motions. In particular, our postulated tension dynamics lead to the instability of a symmetrical steady state, in which the cilium is straight and its active links are under equal tensions. The result of this instability is a stable, wave-like, limit cycle oscillation. We have also investigated the fluid-structure interaction of cilia using the immersed boundary (IB) method. In this setting, we see not only coordination within a single cilium but also, coordinated motion, in which multiple cilia in an array organize their beating to pump fluid, in particular by breaking phase synchronization.
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20
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Cai J, Wang D, Liu J. Regulation of fluid flow through the mammary gland of dairy cows and its effect on milk production: a systematic review. J Sci Food Agric 2018; 98:1261-1270. [PMID: 28758674 DOI: 10.1002/jsfa.8605] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 07/27/2017] [Accepted: 07/27/2017] [Indexed: 06/07/2023]
Abstract
Dairy milk consists of more than 85% water. Therefore, understanding the regulation of fluid absorption in the mammary gland is relevant to improving milk production. In recent decades, studies using different approaches, including blood flow, transmembrane fluid flow, tight junction, fluid flow of the paracellular pathway and functional mammary epithelial cell state, have been conducted aiming to investigate how mammary gland fluid absorption is regulated. However, the relationship between regulation mechanisms of fluid flow and milk production has not been studied systematically. The present review summarizes a series of key milk yield regulatory factors mediated by whole-mammary fluid flow, including milk, mammary blood flow, blood/tissue fluid-cell fluid flow and cell-alveolus fluid flow. Whole-mammary fluid flow regulates milk production by altering transporter activity, ion channels, local microcirculation-related factors, driving force of fluid transport (osmotic pressure or electrochemical gradient), cellular connection state and a cell volume sensitive mechanism. In addition, whole-mammary fluid flow plays important roles in milk synthesis and secretion. Knowledge gained from fluid flow-mediated regulatory mechanisms of the dairy mammary gland will lead to a fundamental understanding of lactation biology and will be beneficial for the improvement of dairy productivity. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Jie Cai
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Diming Wang
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Jianxin Liu
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, China
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21
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Myers EJ, Marshall A, Jennings ML, Parker MD. Mouse Slc4a11 expressed in Xenopus oocytes is an ideally selective H+/OH- conductance pathway that is stimulated by rises in intracellular and extracellular pH. Am J Physiol Cell Physiol 2016; 311:C945-C959. [PMID: 27681179 DOI: 10.1152/ajpcell.00259.2016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 09/28/2016] [Indexed: 11/22/2022]
Abstract
The SLC4A11 gene encodes the bicarbonate-transporter-related protein BTR1, which is mutated in syndromes characterized by vision and hearing loss. Signs of these diseases [congenital hereditary endothelial dystrophy (CHED) and Harboyan syndrome] are evident in mouse models of Slc4a11 disruption. However, the intrinsic activity of Slc4a11 remains controversial, complicating assignment of its (patho)physiological role. Most studies concur that Slc4a11 transports H+ (or the thermodynamically equivalent species OH-) rather than HCO3-, but disparities have arisen as to whether the transport is coupled to another species such as Na+ or NH3/NH4+ Here for the first time, we examine the action of mouse Slc4a11 in Xenopus oocytes. We simultaneously monitor changes in intracellular pH, membrane potential, and conductance as we alter extracellular pH, revealing the electrical and chemical driving forces that underlie the observed ion fluxes. We find that mSlc4a11 is an ideally selective H+/OH- conductive pathway, the action of which is uncoupled from the cotransport of any other ion. We also find that the activity of mSlc4a11 is independently enhanced by both extracellular and intracellular alkalinization, suggesting OH- as the most likely substrate and providing a novel explanation for the apparent NH3-dependence of Slc4a11-mediated currents reported by others. We suggest that the unique properties of Slc4a11 action underlie its value as a pH regulator in corneal endothelial cells.
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Affiliation(s)
- Evan J Myers
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, New York
| | - Aniko Marshall
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, New York
| | - Michael L Jennings
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Mark D Parker
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, New York; .,Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo: The State University of New York, Buffalo, New York; and.,State University of New York Eye Institutes, University at Buffalo: The State University of New York, Buffalo, New York
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22
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Bui N, Meshot ER, Kim S, Peña J, Gibson PW, Wu KJ, Fornasiero F. Ultrabreathable and Protective Membranes with Sub-5 nm Carbon Nanotube Pores. Adv Mater 2016; 28:5871-7. [PMID: 27159328 DOI: 10.1002/adma.201600740] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/05/2016] [Indexed: 05/16/2023]
Abstract
Small-diameter carbon nanotubes (CNTs) are shown to enable exceptionally fast transport of water vapor under a concentration gradient driving force. Thanks to this property, membranes having sub-5 nm CNTs as conductive pores feature outstanding breathability while maintaining a high degree of protection from biothreats by size exclusion.
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Affiliation(s)
- Ngoc Bui
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Eric R Meshot
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Sangil Kim
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - José Peña
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Phillip W Gibson
- U.S. Army Natick Soldier Research, Development and Engineering Center, Natick, MA, 01760, USA
| | - Kuang Jen Wu
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Francesco Fornasiero
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
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23
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Bui N, Meshot ER, Kim S, Peña J, Gibson PW, Wu KJ, Fornasiero F. Carbon Nanotubes: Ultrabreathable and Protective Membranes with Sub-5 nm Carbon Nanotube Pores (Adv. Mater. 28/2016). Adv Mater 2016; 28:6020. [PMID: 27442972 DOI: 10.1002/adma.201670197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A flexible membrane with sub-5 nm single-walled carbon nanotube (SWNT) pores is developed by F. Fornasiero and co-workers, as described on page 5871, for application as a key component of protective, yet breathable fabrics. The SWNTs are shown to enable exceptionally fast transport of water vapor under a concentration driving force. Thus, membranes having SWNTs as moisture-conductive pores feature outstanding breathability and provide a high degree of protection from biological threats by size exclusion.
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Affiliation(s)
- Ngoc Bui
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Eric R Meshot
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Sangil Kim
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - José Peña
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Phillip W Gibson
- U.S. Army Natick Soldier Research, Development and Engineering Center, Natick, MA, 01760, USA
| | - Kuang Jen Wu
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Francesco Fornasiero
- Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
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24
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Viapiana R, Moinzadeh AT, Camilleri L, Wesselink PR, Tanomaru Filho M, Camilleri J. Porosity and sealing ability of root fillings with gutta-percha and BioRoot RCS or AH Plus sealers. Evaluation by three ex vivo methods. Int Endod J 2015. [PMID: 26199130 DOI: 10.1111/iej.12513] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM To investigate the ability of BioRoot RCS, a tricalcium silicate-based root canal sealer and AH Plus to effectively fill the root canals of contralateral teeth using three evaluation methods, and to investigate also the correlation between the methods. METHODOLOGY The prepared root canals of ten pairs of contralateral mandibular premolar teeth were filled with gutta-percha and sealer using lateral compaction. The percentage of voids within the root canal was assessed by micro-computed tomography, whilst sealing ability was investigated by fluid transport and leakage of fluorescent microspheres. The interaction of sealer with dentine, and sealer penetration were assessed by confocal microscopy. The void volume, fluid flow, microsphere leakage and sealer interaction with dentine for both materials were compared. Nonparametric (Mann-Whitney) tests were used to compare the % void and fluid transport of the two sealers. Spearman correlation was used to assess the pairwise relationships between the techniques. The level of significance was set to 0.05. RESULTS BioRoot RCS exhibited significantly more percentage of voids than AH Plus. There was no difference in fluid flow and microsphere penetration. BioRoot RCS exhibited a different pattern of sealer penetration and interaction with the dentine walls compared to AH Plus. For both materials, the pairwise correlations between the three techniques were close to zero, indicating weak relationships. CONCLUSIONS MicroCT analysis revealed a higher void volume for BioRoot RCS. The other techniques did not show a difference between the sealing ability of the sealers. The correlation between the three ex vivo methods of assessment was weak demonstrating their complementarity rather than their concordance.
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Affiliation(s)
- R Viapiana
- Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - A T Moinzadeh
- Department of Endodontology, Academic Center for Dentistry Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - L Camilleri
- Department of Statistics and Operations Research, Faculty of Science, University of Malta, Msida, Malta
| | - P R Wesselink
- Department of Endodontology, Academic Center for Dentistry Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - M Tanomaru Filho
- Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - J Camilleri
- Department of Restorative Dentistry, Faculty of Dental Surgery, University of Malta, Msida, Malta
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25
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Sanders JE, Cagle JC, Allyn KJ, Harrison DS, Ciol MA. How do walking, standing, and resting influence transtibial amputee residual limb fluid volume? J Rehabil Res Dev 2014; 51:201-12. [PMID: 24933719 DOI: 10.1682/jrrd.2013.04.0085] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 09/17/2013] [Indexed: 11/05/2022]
Abstract
The purpose of this research was to determine how fluid volume changes in the residual limbs of people with transtibial amputation were affected by activity during test sessions with equal durations of resting, standing, and walking. Residual limb extracellular fluid volume was measured using biompedance analysis in 24 participants. Results showed that all subjects lost fluid volume during standing with equal weight-bearing, averaging a loss rate of -0.4%/min and a mean loss over the 25 min test session of 2.6% (standard deviation [SD] 1.1). Sixteen subjects gained limb fluid volume during walking (mean gain of 1.0% [SD 2.5]), and fifteen gained fluid volume during rest (mean gain of 1.0% [SD 2.2]). Walking explained only 39.3% of the total session fluid volume change. There was a strong correlation between walk and rest fluid volume changes (-0.81). Subjects with peripheral arterial disease experienced relatively high fluid volume gains during sitting but minimal changes or losses during sit-to-stand and stand-to-sit transitioning. Healthy female subjects experienced high fluid volume changes during transitioning from sit-to-stand and stand-to-sit. The differences in fluid volume response among subjects suggest that volume accommodation technologies should be matched to the activity-dependent fluid transport characteristics of the individual prosthesis user.
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Affiliation(s)
- Joan E Sanders
- Department of Bioengineering, University of Washington, Box 355061, William H. Foege Bldg, 3720 15th Ave NE, Seattle, WA 98195.
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Dahrouj M, Alsarraf O, McMillin JC, Liu Y, Crosson CE, Ablonczy Z. Vascular endothelial growth factor modulates the function of the retinal pigment epithelium in vivo. Invest Ophthalmol Vis Sci 2014; 55:2269-75. [PMID: 24550368 DOI: 10.1167/iovs.13-13334] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Retinal edema, the accumulation of extracellular fluid in the retina is usually attributed to inner blood retina barrier (BRB) leakage. Vascular endothelial growth factor plays an important role in this process. The effects of VEGF on the outer BRB, the RPE, however, have received limited attention. Here, we present a methodology to assess how VEGF modulates the integrity of the RPE barrier in vivo. METHODS Control subretinal blebs (1-5 μL) and blebs containing VEGF (1-100 μg/mL), placental growth factor (PlGF; 100 μg/mL), or albumin (100-1000 μg/mL) were injected into New Zealand White or Dutch Belted rabbits with IOP maintained at 10, 15, or 20 mm Hg. One-hour intravitreal pretreatment with ZM323881 (10 μM/L) was used to inhibit the VEGF response. Fluid resorption was followed by optical coherence tomography for 1 hour. Retinal pigment epithelium leakage was assessed by fluorescein angiography. RESULTS Increasing IOP resulted in an elevated rate of bleb resorption, while increasing albumin concentration in the bleb decreased the rate of resorption. Vascular endothelial growth factor, but not PlGF, caused a significant, concentration-dependent decrease in the rate of fluid resorption, which was reversed by ZM323881. Compared with albumin-filled blebs, VEGF-filled blebs showed accelerated early-phase leakage from the choroid. CONCLUSIONS Consistent with a localized modulation of RPE function, VEGF induced a significant reduction in fluid resorption and an increase in hydraulic conductivity. Our results establish VEGF as a major cytokine regulating RPE barrier properties in vivo and indicate that the RPE is a principal factor in the pathogenesis of retinal edema.
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Affiliation(s)
- Mohammad Dahrouj
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
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Abstract
Two-dimensional paper networks (2DPNs) hold great potential for transcending the capabilities and performance of today's paper-based analytical devices. Specifically, 2DPNs enable sophisticated multi-step chemical processing sequences for sample pretreatment and analysis at a cost and ease-of-use that make them appropriate for use in settings with low resources. A quantitative understanding of flow in paper networks is essential to realizing the potential of these networks. In this report, we provide a framework for understanding flow in simple 2DPNs using experiments, analytical expressions, and computational simulations.
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Affiliation(s)
- Elain Fu
- Department of Bioengineering, Box 355061, University of Washington, Seattle, WA, 98195,USA
| | - Stephen A. Ramsey
- Institute for Systems Biology, 1441 N. 34 St., Seattle, WA, 98103, USA
| | - Peter Kauffman
- Department of Bioengineering, Box 355061, University of Washington, Seattle, WA, 98195,USA
| | - Barry Lutz
- Department of Bioengineering, Box 355061, University of Washington, Seattle, WA, 98195,USA
| | - Paul Yager
- Department of Bioengineering, Box 355061, University of Washington, Seattle, WA, 98195,USA
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Ma L, Kuang K, Smith RW, Rittenband D, Iserovich P, Diecke F, Fischbarg J. Modulation of tight junction properties relevant to fluid transport across rabbit corneal endothelium. Exp Eye Res 2007; 84:790-8. [PMID: 17320078 PMCID: PMC1993899 DOI: 10.1016/j.exer.2006.12.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Revised: 11/30/2006] [Accepted: 12/15/2006] [Indexed: 11/20/2022]
Abstract
Paracellular junctions could play an important role in corneal endothelial fluid transport. In this study we explored the effects of different reagents on the tight junctional barrier by assessing the translayer specific electrical resistance (TER) across rabbit corneal endothelial preparations and cultured rabbit corneal endothelial cells' (CRCEC) monolayers, the paracellular permeability (Papp) for fluorescein isothiocyanate (FITC) dextrans across CRCEC, and fluid transport across de-epithelialized rabbit corneal endothelial preparations. Palmitoyl carnitine (PC), poly-L-lysine (PLL), adenosine triphosphate (ATP), and dibutyryl adenosine 3',5'-cyclic monophosphate (dB-cAMP) were used to modulate corneal endothelial fluid transport and tight junctions (TJs). After seeding, the TER across CRCEC reached maximal values (29.2+/-1.0 Omega cm2) only after the 10th day. PC (0.1 mM) caused decreases both in TER (by 40%) and fluid transport (swelling rate: 18.5+/-0.3 microm/h), and an increase in Papp. PLL resulted in increased TER rose and Papp but decreased fluid transport (swelling rate: 10+/-0.3 microm/h). dB-cAMP (0.1 mM) and ATP (0.1 mM) decreased TER by 16% and 6%, increased Papp slightly, and stimulated fluid transport; the rates of de-swelling (in microm/h) were -5.4+/-0.3 and -12.1+/-0.4, respectively. PC might cause the junctions to open up unspecifically and thus increase passive leak. PLL is a known junctional charge modifier that may be adding steric hindrance to the tight junctions. The results with dB-cAMP and ATP are consistent with fluid transport via the paracellular route.
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Affiliation(s)
- Li Ma
- Department of Ophthalmology, College of Physicians and Surgeons, Columbia University
| | - Kunyan Kuang
- Department of Ophthalmology, College of Physicians and Surgeons, Columbia University
| | | | | | - Pavel Iserovich
- Department of Ophthalmology, College of Physicians and Surgeons, Columbia University
| | - F.P.J. Diecke
- Dept. of Pharmacology and Physiology, UMDNJ-New Jersey Medical School, Newark, NJ
| | - Jorge Fischbarg
- Department of Ophthalmology, College of Physicians and Surgeons, Columbia University
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University
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Abstract
1. The influence of the sympathetic nervous system on intestinal fluid transport by the jejunum and ileum of the anaesthetized rat was investigated under basal conditions and during active secretion induced by intra-arterial infusion of vasoactive intestinal peptide (VIP). 2. Intra-arterial infusion of noradrenaline (3, 10, 30 nmol min-1, i.a.) and i.v. injection of the selective alpha 2-adrenoceptor agonist UK 14,304 (1 mumol kg-1, i.v.) increased the rate of basal fluid absorption. The effect of UK 14,304 was blocked by yohimbine (10 mumol kg-1, i.v.). However, the selective alpha 1-adrenoceptor agonist phenylephrine (5 mumol kg-1, i.v.) did not alter either the jejunal or ileal absorption rate. 3. The alpha 2-adrenoceptor antagonists yohimbine (0.3, 1.0, 3 and 10 mumol kg-1, i.v.) and rauwolscine (10 mumol kg-1, i.v.) decreased the basal absorption rate, while the alpha 1-adrenoceptor antagonist prazosin (3 mumol kg-1, i.v.) was without effect. Intracerebroventricular injection of yohimbine (3 mumol kg-1) caused a significant antiabsorptive effect in the jejunum but not ileum. 4. Peripheral chemical sympathectomy induced by pretreating animals with 6-hydroxydopamine (150 mg kg-1, i.p., total dose) induced a trend towards impaired absorption in the jejunum and ileum. 5. The findings provide evidence that the sympathetic nervous system exerts tonic control on intestinal fluid transport and that the effect is mainly through peripheral alpha 2-adrenoceptors. 6. The subtype determination of alpha 2-adrenoceptors in modulating intestinal fluid transport was assessed by determining the effects of alpha 2-adrenoceptor agents on intestinal fluid secretion induced by i.a. infusion of VIP (0.8 microgram min-1). 7. Intravenous administration of UK 14,304 caused a dose-dependent reversal of the secretory phase of the VIP-induced response, but failed to restore fluid transport to the control level of net absorption. EC50 values were 0.17 mumol kg-1 in the jejunum and 0.22 mumol kg-1 in the ileum. 8. The effect of UK 14,304 was blocked by the selective alpha 2A/D antagonist BRL 44408 and the nonselective alpha 2 antagonist yohimbine (each 10 mumol kg-1). The selective alpha 2B/C antagonist ARC 239 (10 mumol kg-1) did not affect the antisecretory action of UK 14,304. It is suggested that the alpha 2-adrenoceptors in the rat intestinal epithelium are the alpha 2D or alpha 2A-like subtype.
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Affiliation(s)
- L Liu
- Department of Pharmaceutical Biology and Pharmacology, Victorian College of Pharmacy, Monash University, Parkville, Australia
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