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American Journal of Physiology. Cell... Jan 2019Mucociliary clearance is critically important in protecting the airways from infection and from the harmful effects of smoke and various inspired substances known to... (Review)
Review
Mucociliary clearance is critically important in protecting the airways from infection and from the harmful effects of smoke and various inspired substances known to induce oxidative stress and persistent inflammation. An essential feature of the clearance mechanism involves regulation of the periciliary liquid layer on the surface of the airway epithelium, which is necessary for normal ciliary beating and maintenance of mucus hydration. The underlying ion transport processes associated with airway surface hydration include epithelial Na channel-dependent Na absorption occurring in parallel with CFTR and Ca-activated Cl channel-dependent anion secretion, which are coordinately regulated to control the depth of the periciliary liquid layer. Oxidative stress is known to cause both acute and chronic effects on airway ion transport function, and an increasing number of studies in the past few years have identified an important role for autophagy as part of the physiological response to the damaging effects of oxidation. In this review, recent studies addressing the influence of oxidative stress and autophagy on airway ion transport pathways, along with results showing the potential of autophagy modulators in restoring the function of ion channels involved in transepithelial electrolyte transport necessary for effective mucociliary clearance, are presented.
Topics: Adaptor Proteins, Signal Transducing; Animals; Autophagy; Humans; Ion Transport; Mucociliary Clearance; Oxidative Stress; Respiratory Mechanics
PubMed: 30303690
DOI: 10.1152/ajpcell.00341.2018 -
American Journal of Physiology. Renal... Jan 2017Unique experimental advantages, such as its embryonic/larval transparency, high-throughput nature, and ease of genetic modification, underpin the rapid emergence of the... (Review)
Review
Unique experimental advantages, such as its embryonic/larval transparency, high-throughput nature, and ease of genetic modification, underpin the rapid emergence of the zebrafish (Danio rerio) as a preeminent model in biomedical research. Particularly in the field of nephrology, the zebrafish provides a promising model for studying the physiological implications of human solute transport processes along consecutive nephron segments. However, although the zebrafish might be considered a valuable model for numerous renal ion transport diseases and functional studies of many channels and transporters, not all human renal electrolyte transport mechanisms and human diseases can be modeled in the zebrafish. With this review, we explore the ontogeny of zebrafish renal ion transport, its nephron structure and function, and thereby demonstrate the clinical translational value of this model. By critical assessment of genomic and amino acid conservation of human proteins involved in renal ion handling (channels, transporters, and claudins), kidney and nephron segment conservation, and renal electrolyte transport physiology in the zebrafish, we provide researchers and nephrologists with an indication of the possibilities and considerations of the zebrafish as a model for human renal ion transport. Combined with advanced techniques envisioned for the future, implementation of the zebrafish might expand beyond unraveling pathophysiological mechanisms that underlie distinct genetic or environmentally, i.e., pharmacological and lifestyle, induced renal transport deficits. Specifically, the ease of drug administration and the exploitation of improved genetic approaches might argue for the adoption of the zebrafish as a model for preclinical personalized medicine for distinct renal diseases and renal electrolyte transport proteins.
Topics: Animals; Ion Transport; Kidney; Kidney Diseases; Membrane Transport Proteins; Models, Animal; Nephrons; Zebrafish
PubMed: 27852607
DOI: 10.1152/ajprenal.00425.2016 -
Current Opinion in Gastroenterology Mar 2009In recent years, the field of intestinal physiology has witnessed significant progress in our understanding of the expression and function of ion transport proteins and... (Review)
Review
PURPOSE OF REVIEW
In recent years, the field of intestinal physiology has witnessed significant progress in our understanding of the expression and function of ion transport proteins and their genes under physiological and pathophysiological conditions. This review will present some of these most recent advances in the small intestinal ion transport mechanisms.
RECENT FINDINGS
One of the new and exciting aspects of this field has been the integration of function and structure of several intestinal transport processes. This is well exemplified by the discussed intricacies of intestinal bicarbonate secretion as well as the role of scaffolding PDZ proteins interacting with several transporters. We also discuss some of the most recent data pointing to the role of ion transporters in the pathogenesis of inflammation-associated diarrhea and their potential role in the maintenance of epithelial integrity.
SUMMARY
Mouse models deficient in some of the key genes encoding ion transporters and their adapter proteins continue to provide important clues into intestinal transport processes. Several of the new in-vivo findings revise or complement past paradigms, many of which were derived from in-vitro approaches. New data on the interdependent functions of multiple transporters, as exemplified here by intestinal bicarbonate secretion, increase the complexity of the intestinal ion transport mechanisms and continue to contribute to a more integrated view of the transport phenomena in the gut. Data from patients and mouse models of intestinal inflammation also increase our understanding of the pathophysiology of inflammation-associated diarrhea.
Topics: Animals; Bicarbonates; Duodenum; Humans; Inflammation; Intestinal Mucosa; Ion Transport; Membrane Transport Proteins; Mice; Models, Animal; Phosphoproteins; Sodium-Hydrogen Exchangers
PubMed: 19528875
DOI: 10.1097/MOG.0b013e3283260900 -
WormBook : the Online Review of C.... Dec 2014The facilitated movement of ions across cell membranes can be characterized as occurring through active (ATP-dependent), secondary active (coupled), or passive transport... (Review)
Review
The facilitated movement of ions across cell membranes can be characterized as occurring through active (ATP-dependent), secondary active (coupled), or passive transport processes. Each of these processes is mediated by a diverse group of membrane proteins. Over the past fifteen years, studies of membrane transport in C. elegans have benefited from the fact that worms are anatomically simple, easily and economically cultured, and genetically tractable. These experimental advantages have been instrumental in defining how membrane transport processes contribute to whole organism physiology. The focus of this review is to survey the recent advances in our understanding of membrane transport that have arisen from integrative physiological approaches in the nematode C. elegans.
Topics: Animals; Caenorhabditis elegans; Calcium Signaling; Cell Membrane; Ion Transport
PubMed: 25536490
DOI: 10.1895/wormbook.1.174.1 -
Current Opinion in Insect Science Oct 2021
Topics: Animals; Ion Transport
PubMed: 34598751
DOI: 10.1016/j.cois.2021.09.002 -
Cell Calcium Jul 2017Enamel is the most calcified tissue in vertebrates. It differs from bone in a number of characteristics including its origin from ectodermal epithelium, lack of... (Review)
Review
Enamel is the most calcified tissue in vertebrates. It differs from bone in a number of characteristics including its origin from ectodermal epithelium, lack of remodeling capacity by the enamel forming cells, and absence of collagen. The enamel-forming cells known as ameloblasts, choreograph first the synthesis of a unique protein-rich matrix, followed by the mineralization of this matrix into a tissue that is ∼95% mineral. To do this, ameloblasts arrange the coordinated movement of ions across a cell barrier while removing matrix proteins and monitoring extracellular pH using a variety of buffering systems to enable the growth of carbonated apatite crystals. Although our knowledge of these processes and the molecular identity of the proteins involved in transepithelial ion transport has increased in the last decade, it remains limited compared to other cells. Here we present an overview of the evolution and development of enamel, its differences with bone, and describe the ion transport systems associated with ameloblasts.
Topics: Ameloblasts; Animals; Dental Enamel; Humans; Ion Transport
PubMed: 28389033
DOI: 10.1016/j.ceca.2017.03.006 -
Electrophoresis Dec 2023In recent years, researchers have made significant strides in understanding the ion transport characteristics of nanochannels, resulting in the development of various...
In recent years, researchers have made significant strides in understanding the ion transport characteristics of nanochannels, resulting in the development of various materials, modifications, and shapes of nano ion channel membranes. The aim is to create a nanochannel membrane with optimal ion transport properties and high stability by adjusting factors, such as channel size, surface charge, and wettability. However, during the nanochannel film fabrication process, controlling the geometric structures of nanochannels can be challenging. Therefore, exploring the stability of nanochannel performance under different geometric structures has become an essential aspect of nanochannel design. This article focuses on the study of cylindrical nanochannel structures, which are categorized based on the different methods for generating bipolar surface charges on the channel's inner surface, either through pH gradient effects or different material types. Through these two approaches, the study designed and analyzed the stability of ion transport characteristics in two nanochannel models under varying geometric structures. Our findings indicate that nanochannels with bipolar properties generated through pH gradients demonstrate more stable ion selection, whereas nanochannels with bipolar properties generated through different materials show stronger stability in ion rectification. This conclusion provides a theoretical foundation for future nanochannel designs.
Topics: Ion Transport; Ion Channels; Hydrogen-Ion Concentration
PubMed: 37401641
DOI: 10.1002/elps.202300073 -
Analytical Sciences : the International... Apr 2022A pair of symmetrical cathodic and anodic peaks is observed in cyclic voltammograms for the ion transport across a bilayer lipid membrane (BLM) between two aqueous...
A pair of symmetrical cathodic and anodic peaks is observed in cyclic voltammograms for the ion transport across a bilayer lipid membrane (BLM) between two aqueous phases in the presence of tetraphenylborate (TPhB). Although TPhB serves as a carrier of a hydrophilic counter ion (Na) under the steady-state condition, the reason for the appearance of symmetrical peaks has not been clearly explained until now. From the chronoamperometric analysis, it is turned out that the symmetrical peaks are attributed to the translocation of TPhB between two adsorbed layers on the surface of the BLM.
Topics: Hydrophobic and Hydrophilic Interactions; Ion Transport; Ions; Lipid Bilayers; Tetraphenylborate
PubMed: 35286650
DOI: 10.1007/s44211-022-00086-7 -
Current Topics in Membranes 2022Cardiovascular disease is on the rise, partially due to the continued increase in metabolic syndrome. Advances in basic research on vascular ion transport have the...
Cardiovascular disease is on the rise, partially due to the continued increase in metabolic syndrome. Advances in basic research on vascular ion transport have the potential to provide targets for therapeutic interventions. Vascular specificity, which includes different vascular beds having different characteristics and the macro- vs. microvasculature, is a vitally important variable in characterization of ion transport. At the cellular level, targeted fluorescent biosensors for Ca, super-resolution microscopy, and organelle patch clamp electrophysiology enable more detailed studies. The "MetS/diabetes milieu" includes increased and decreased insulin, and increased glucose, increased LDL/HDL cholesterol and triglycerides, and increased blood pressure. The duration and severity of MetS/diabetes components certainly affect the vascular phenotype and ion transport and membrane interactions. A combination of in vivo animal models and in vitro cell models to study ion transport in MetS/diabetes conditions is optimal. Gene editing and selective pharmacological tools should be used after or in conjunction with characterization of ion transport in vascular health and disease phenotypes. This is critical to determining the causal role of Ca signaling in modulation of vascular phenotype. The ion transport and membrane interactions that are measured are typically only a snapshot in time in these dynamic processes occurring over the progression of health and disease. It is imperative that this concept be considered in the planning of long-term studies of vascular disease, ion transport experiments, and interpretation of the data. Future directions for our contributors' research will advance the field.
Topics: Animals; Metabolic Syndrome; Cardiovascular Diseases; Diabetes Mellitus; Ion Transport
PubMed: 36368870
DOI: 10.1016/bs.ctm.2022.09.006 -
The Journal of Experimental Biology Feb 2022This Review addresses the means by which epithelia change the direction of vectorial ion transport. Recent studies have revealed that insect Malpighian (renal) tubules... (Review)
Review
This Review addresses the means by which epithelia change the direction of vectorial ion transport. Recent studies have revealed that insect Malpighian (renal) tubules can switch from secreting to reabsorbing K+. When the gut of larval lepidopterans is empty (during the moult cycle) or when the larvae are reared on K+-deficient diet, the distal ileac plexus segment of the tubule secretes K+ from the haemolymph into the tubule lumen. By contrast, in larvae reared on K+-rich diet, ions and fluid are reabsorbed from the rectal lumen into the perinephric space surrounding the cryptonephridial tubules of the rectal complex. Ions and fluid are then transported from the perinephric space into the lumen of the cryptonephridial tubules, thus supplying the free segments of the tubule downstream. Under these conditions, some of the K+ and water in the tubule lumen is reabsorbed across the cells of the distal ileac plexus, allowing for expansion of haemolymph volume in the rapidly growing larvae, as well as recycling of K+ and base equivalents. RNA sequencing data reveal large-scale changes in gene transcription that are associated with the switch between ion secretion and ion reabsorption by the distal ileac plexus. An unexpected finding is the presence of voltage-gated, ligand-gated and mechanosensitive ion channels, normally seen in excitable cells, in Malpighian tubules. Transcriptomic surveys indicate that these types of channels are also present in multiple other types of vertebrate and invertebrate epithelia, suggesting that they may play novel roles in epithelial cell signalling and regulation of epithelial ion transport.
Topics: Animals; Ion Transport; Ions; Larva; Malpighian Tubules; Moths; Potassium
PubMed: 35119072
DOI: 10.1242/jeb.243293